Investigación Clínica

A case of a 50 years-old breast cancer patient treated with weekly paclitaxel and BIBF 1120 is reported herein. At the end of the twelfth cycle of chemotherapy, the patient developed distal onycholysis with intense hyponychium serous exudates, pain and malodor in all her fingernails. It was treated with topical fusidic acid and 1% methylprednisolone aceponate two times daily, with an excellent clinical response from the first three days of treatment. Bacterial paronychia with nail plate loss of the fifth left fingernail was observed a week after the topical therapy was started, with positive cultures for Methicillin susceptible Staphylococcus aureus. There are few reported cases of exudative onycholysis associated with chemotherapy. However, these are especially related to paclitaxel. No recurrences of nail disturbances were observed weeks after the end of chemotherapy. Topical corticosteroids and fusidic acid could be considered as a therapeutic option when exudative onycholysis related to paclitaxel is established

Mucopolysaccharidoses are a group of lysosomal storage disorders caused by deficiency of enzymes catalyzing the degradation of glycosaminoglycans. Mucopoly-saccharidosis I can present a wide range of phenotypic characteristics with three major recognized clinical entities: Hurler and Scheie syndromes represent phenotypes at the severe and mild ends of the clinical spectrum, respectively, and the Hurler-Scheie syndrome is intermediate in phenotypic expression. These are caused by the deficiency or absence of alpha-L-iduronidase, essential to the metabolism of both dermatan and heparan sulfate, and it is encoded by the lDUA gene. We report the case of a 34-year-old male patient with enzymatic deficiency of alpha-L-iduronidase, accumulation of its substrate and a previously unreported mutation in the IDUA gene that developed a phenotype of Scheie syndrome.

Dengue is characterized by fever, headache, arthralgia and myalgia. The presence of gastrointestinal signs and symptoms (GISS) is considered a sign of alarm in dengue; however, little information exists regarding the occurrence of these events. The aim of this study was to determine the frequency of gastrointestinal signs and symptoms in a cohort of patients with dengue. A total of 1484 medical records of patients with confirmed dengue were reviewed and classified as: dengue without warning signs (DNWS) (n = 700), dengue with warning signs (DWWS) (n = 700) and severe dengue (SD) (n = 84). Of the studied records, 65.71% of patients with DNWS, 92.59% with DWWS and 100% of patients with SD had GISS. In patients with DNWS, nausea / vomiting were the most common symptoms in 319/700 cases (45.57%), followed by abdominal pain in 142/700 (20.29%) and diarrhea in 125/700 (17.86%). There were no cases with melena, hepatomegaly or hematemesis. While in DWWS nausea/vomiting were present in 529/700 (75.57%), abdominal pain in 439/700 (62.71%) and diarrhea in 198/700 (28.28%),(p <0.0001). Melena, hematemesis and hepatomegaly ranged from 0.57% to 1.86% of cases. In SD, nausea/vomiting were registered in 100% of the cases, abdominal pain in 82/84 (97.62%), diarrhea in 65/84 (77.38%), melena in 32/84 (38.10%), hepatomegaly in 28/84 (33.33%) and hematemesis in 26/84 (30.95%). It was evident the high frequency of GISS in cases of DWWS and SD, in contrast to DNWS, in which the frequency of GISS was significantly lower. This suggests a relationship of GISS with the severity of dengue, and their presence should be considered by the decision-making health team for appropriate patient management.

Ninety-one non cancerous samples from genital specimens positives for VPH 16 or 18 and 27 non-infected samples as controls were studied. Mutations at codon 12 in K-ras gene was analyzed using enriched alelic PCR technique. Among the samples studied 17.58% showed mutations in this codon. Significant differences were observed between the control group (negative DNA-HPV) and positives DNA-HPV samples (p < 0.01). No differences were found between both viral types in relation to the mutation frequency. The presence of mutations in the K-ras gene in non cancerous cytological samples point out new questions about the role of mutations in proto-oncogenes and the development of cervical cancer.

The Asymmetric Crying Facies (ACF) is included among the congenital facial palsy in childhood. We report the clinical characteristics, congenital anomalies and other associated disorders in sixteen patients with ACF examined from 1984 to 1995 in the pediatric units of the Hospital Adolfo Pons, Universitario and Clínico of Maracaibo, Venezuela. Statistically the side of lesion and the sex were independent. In seven of sixteen patients (43.75%) we found congenital anomalies and/or neurological disorders, being diaphragmatic hernia and the hyperkinesia a rare association no reported up to now in the reviewed literature. We suggest autosomal dominant inheritance with reduced penetrance in three of sixteen families. The other patients were sporadic cases.

A congenital malformations surveillance program in effect at the Ruiz y Páez Hospital in Ciudad Bolívar since April 1978, has allowed us to detect 25 patients with osteochondrodysplasias (OCD) in a total of 70,152 newborns, up to August 1990, for a prevalence of one case of OCD every 2,806 newborns. The clinical entities found were: Achondroplasia, Thanatophoric Dysplasia, Osteogenesis Imperfecta II-A, Camptomelic Dysplasia, Kniest Dysplasia, Conradi-Hunnerman syndrome, Parenti-Fracaro type Achondrogenesis and Jeune Asphyxiating Thoracic Dysplasia. The results presented in this paper indicate that this type of diseases represent a relatively important group of nosological entities adding up to more than 200 new annual cases in the country. This relatively high frequency, the different inheritance mechanisms involved, the variable complications and the high morbidity and mortality rate of these diseases, make the patients affected, a problematic group not receiving, in general, adequate medical attention regarding diagnosis, genetic counselling and treatment.

During the period of 1979-1990 job-related injuries were studied in Maracaibo, Zulia state, in order to analyze frequencies and causes. This information was obtained from annual reports on job-related injuries Form Number 15-411 of the Venezuelan Institute of Social Security (IVSS) which has been implemented nationally since 1982. Accidents that caused loss of man-hours were considered; variables considered were: age, risk category, day of the week, work shift, month, type of accident, agent, type of lesion, mechanical cause, body part affected and type of the activity in which the company is involved. The results were expressed as absolute values (mean +/- SE) and relative values. The mean accidents/year was 1651 +/- 177.97, most of them occurring in the age groups of 20-29 years (368.8) and 30-39 years (359.8). The triannual mean rate was higher for the group of the non-serious accidents (50%). Tuesday was the day of higher accidental incidence (22%) in addition to the morning shift between 9 and 11 hours (55%). Manufacturing was the economic activity most affected (43%). The most common causative agents were materials, substances and radiations (35%). The use of defective tools were the most frequent causes of mechanical accidents (31%). Upper limbs (46%) and between the type of lesion contusions or/and bruises (53%). It was concluded that, although the number of workers and accidents slowly diminished, the accidents rate slightly increased.

The Medical Genetics Unit at Universidad del Zulia (UGM-LUZ) gives counsel to patients with partial and total genetic diseases. Counseling is available for patients of both sexes and all ages, from public and private health centers and several medical specialities. In the present study an analysis of 4617 clinical records from families referred for genetic counseling to the UGM-LUZ is given. The study spans from January 1983 to December 1992. Fifty four (1.2%) of these histories correspond to pre-nuptial counseling, 773 (16.7%) pre-conceptional, 316 (6.8%) pre-natal and 3474 (75.3%) for diagnosis. A computerized system was developed, based on relational data base manager, that permits access with interactive Dbase type applications. A total of 5433 diagnoses were made. The most frequent causes of genetic diseases were chromosomal abnormalities (12.32%), mainly Down and Turner syndromes. Mendelian diseases occupied 14.45% of all cases, with Marfan and Noonan syndrome, Osteogenesis imperfecta. Duchenne-Becker muscular dystrophy and Incontinentia Pigmenti as the most frequent syndromes. Diseases that involve multifactorial inheritance, such as neural tube defects, accounted for 7.36% of all diagnosis. Effects of teratogenic agents such as german measles, radiations and others were detected in 3.96% of all cases. In 8.5% of the patients a hereditary factor was suspected. No definitive diagnosis was reached in 32.45% of all cases and 20.96% of the patients were normal. The need for data from other medical genetic centers is stressed. In this way the regional and national genetic diseases on morbidity can be known.

In order to analyze the frequency, injury rate and cause of on site accidents to the hands of workers on the east coast of lake of Maracaibo in Zulia State, data was obtained from the accident reports registered with the Venezuelan Institute of Social Security. An occupational hand injury was defined as a traumatic injury to the hands, fingers or wrists that occurred while the employee was at work; that resulted from a single exposure to a hazardous agent. The following variables were analyzed: age, severity, economic activity, material agent, mechanic cause, type of injury, type of accident and unsafe action. The frequency rate was used to analyze the annual accident rate. During the period under study 2.456 injuries to the hand were registered, representing 36% of the total injuries reported; 95% were light injuries, 5% incapacitating and two cases resulted in the death of the worker. 72% of the injuries were located in the fingers, 22% in the hands and 6% in the wrists. The greatest frequency of injuries were found in the economic activity in mines and quarries with a rate of 123.1 per thousand. The age group most affected was of 20-29 years (42%), Wounds or contusions and crushings were the injuries most commonly reported, in 39% and 36% of the cases respectively. The main type of injuries were caused by run over, running into or blow from objects. The principal agents causing injuries were materials, substances and radiations in 45% of the cases. It is concluded that the hand injury rate is very high in the exploitation of mines and quarries and represents the main cause of worker's disability.

Incidence of anencephaly in the State of Zulia, and specifically in the Eastern Coast of Lake Maracaibo, an oil exploitation area, has been declared high since the beginning of the 80's, coincident with the generalized use of ultrasound as a diagnostic tool for fetal evaluation. Through the Birth Defects Preventive Program, established at the Hospital Chiquinquirá in Maracaibo, we have developed a fourfold strategy for the study of birth defects: i) analysis of more than 32,332 ultrasound evaluations within the Ultrasound Service, between 1993 and 1996, ii) a case-control malformation registry beginning in 1995, iii) a study of malformed stillbirths at the Pathology Service, observed after 4232 deliveries within this hospital, and iv) a registry of over 638 mothers with high risk pregnancy for fetal defects detected at the prenatal clinic and carried out at the Perinatal Medical Genetics Service. As a reference population we study 345 medical histories obtained from the Medical Genetics and Prenatal Diagnostic Service at Hospital Coromoto, and oil companies related medical facility. This approach has led us to conclude that the incidence of anencephaly in the State of Zulia is 0.75/1000, significantly similar to that expected for most populations.

In 1993 a total of 356 accidents with injuries occurred in workers of 26 companies of oil and gas extraction in the eastern coast of Maracaibo Lake in Venezuela. 288 of them worked in drilling tasks. With the purpose of analyzing the factors that are associated with the drilling activities, the data base of the Venezuela Institute of Social Security, was reviewed. Only the first two digits of the Standard Industrial Classification were used in this study. For preventive reasons this study focused on six variables: unsafe condition or mechanical cause, insecure action, external agent, type of the accident, part of the body injured and the nature of the injury. The following results were obtained: the frequency rate was 222.3 by 1,000, most of them were minor and were caused by not paying attention when walking on or around labor areas (37%), thus favoring being struck by lifting machines (14%); also 62% occurred in non-classified conditions that injured the upper and lower extremities (48% and 24%) producing contusions and crushing (39%). In conclusion, most injuries occurring in the activity of oil and gas extraction are due to factors controllable with preventive strategies.

Transmission electron microscopy of the brain in 25 newborn mice was performed. Mice were intracerebrally inoculated with cultured VERO cells infected with VEE to be used as positive control, with samples of serum of cerebrospinal fluid from patients with clinical symptoms and signs of encephalitis, with serum from healthy patients or with serum from sick equines. Borate bovine albumin serum was also inoculated in some mice to be used as negative control. All samples were obtained during the epizootic and epidemic outbreak in the Venezuelan Guajira area, northern of Zulia State during October 1995. The ultrastructural study was blindly performed, however the presence of Togavirus particles were detected in 100% of the virologically positive cases. The usefulness, accuracy and speed of the employed methodology is stressed.

Rabies is a zoonotic viral disease and in Zulia State, it constitutes a public health problem of a high social impact, due to the report of cases in human beings. In this study, the presence of urban rabies was determined in Zulia's State and its distribution was identified according to municipalities and affected species during 1996-2006. In the scope of a descriptive study, a documented revision of Zulia's State Zoonosis Regional Coordination registries for the period in study was carried out. A total occurrence of 1.033 rabies cases was observed, 1.017 were in animals and 16 in human beings. The biggest incidences were for Maracaibo (31.40%) and San Francisco (15.68%) municipalities. The type of predominant rabies was the urban one; the principal reservoir and transmitter was the canine one (91.60%). Of the reported cases in human beings, the biggest incidence was in in Maracaibo Municipality (37.5%) and the most affected age group was <15 years (81.2%). A low percentage in the coverage of vaccination was presented (33%). A high incidence of rabies is demonstrated in Zulia's State in spite of this being a preventable immune disease. A positive correlation was determined between the number of admissions and cases (rs=0.948 P<0.01). It is necessary to implement an effective control of the sources of infection and to support a minimal coverage of vaccination of 80% in canines and furthermore, to implement community education programs, to diminish the risk of infection and the occurrence of cases.

The data of accidents caused by snakebites in Venezuela, registered at the morbidity statistics of the Direction of Epidemiology and Strategic Analysis of the Ministry of Health and Social Development were analyzed. During the years of 1996-2004, 53,792 snakebites were registered in Venezuela (5,976 cases average per year), with a higher incidence during the year 2004 (7,486 incidents). Zulia reported the highest frequency of all the states (5,975 cases); meanwhile the Midwestern region, constituted by Lara, Portuguesa, Falc6n and Yaracuy states, had a higher morbidity for snake bites. The highest incidence, distributed per states was registered in Cojedes, during the year 2001, with 228.72 cases per 100,000 inhabitants. When it was determined by regions, the highest incidence occurred during the year 2004 at los Llanos with 63.81 per 100,000 inhabitants. The median of the incidence rate for Venezuela during the period was of 21.46 accidents per 100,000 inhabitants. The classification of the endemic areas for ophidism, according to the percentiles 23, 50, 75 and 90, organized the country in: (a) states and regions of very high endemicity, (b) high endemicity, (c) middle, (d) low and (e) very low endemicity. These epidemiological data indicated that the accidents caused by snakes constitute a collective health problem in Venezuela.

The Insular Municipality of Almirante Padilla, historically, has been affected by Venezuelan Equine Encephalitis (VEE) epidemics, that have occurred cyclically in the Paez, Mara and Almirante Padilla Municipalities of the State of Zulia. During the last epidemic outbreak (1995), the studies reported a great number of cases of VEE in humans, based on epidemiologic-clinical diagnosis; occupying this municipality, the first place in the attack rate by the virus. At the same time, Dengue has been defined as an endemic illness affecting different regions, whose etiologic agent has previously circulated in the studied zone. In order to evaluate the immunity acquired against these viruses, a serological study was conducted in San Carlos Island. Two hundred and ten blood samples were obtained at random, among individuals of an age range between < 1 and 69 years, with and without antecedents of viral illness symptomatology at the moment of the epidemic outbreak, occurred in 1995. The samples were classified according to sex and age, and analyzed through the test of ELISA for specific IgG antibodies against the VEE and Dengue viruses. From the total of the samples processed, 116 (55.2%) were positive for VEE, affecting uniformly all age-groups with a slight masculine predominance. Likewise, 88 cases (41.9%) were determined positive for Dengue virus, affecting mainly the group ranging from 10 to 19 years. These results let us suggest that the epidemic outbreak occurred in 1995 at the Almirante Padilla Insular Municipality, had a double nature with both viruses being involved in the etiology of febrile cases.

The efficacy of a proactive dengue surveillance system to predict epidemics depends on the laboratory diagnostic capacity for an early detection of virus circulation. This study shows the results of the dengue virologic and serologic surveillance accomplished in Aragua State (Venezuela) from October 1997 to December 1998. Five hundred and forty seven sera from suspected dengue patients were tested using the techniques of Virus Isolation and Immunofluorescence Serotyping (VIIS), Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR), Anti-dengue IgM Capture Enzyme Immunoassay (MAC-ELISA) and Haemagglutination Inhibition test (HI). Of the tested sera, 97.4% resulted positive to at least one technique; of these, 60.4% were classified as confirmed cases (virologically positives) and 39.6% as probable cases (virologically negatives/serologically positives). Though the majority of positive cases occurred during the 1997 and 1998 epidemic periods, the gradual increase of the seropositive rates between both periods suggested the incoming 1998 outbreak. Den-1 (51.2%), Den-2 (37.9%) and Den-4 (10.6%) infected patients were detected as well as one dual infection of Den-2 and Den-4 (0.3%). Dengue hyperendemicity (co-circulation of Den-1, Den-2 and Den-4) in Aragua State was confirmed together with the detection of few cases (6.5%) of Dengue Hemorrhagic Fever/Dengue Shock Syndrome cases (HF/DSS); 38.1% of these cases occurred in patients with secondary infections. The high percentage (85.7%) of DHF/DSS cases infected by Den-2 virus supports the reported virulence of this serotype.

Werner in 1915, described a patient is characterized by a tibial bilateral aplasia or hypoplasia, polydactyly and absent thumbs. Autosomal dominant inheritance is demonstrated, with variable expressivity. The objective of this work is to describe a child with clinic and radiologic signs of Tibial Hypoplasia with Polydactyly. The genealogic study allowed us to suppose that the gene has a variable expressivity, since in the maternal branch, malformations such as syndactyly of hands, proximal implantation of thumbs and tibiae vara, have been found. The clinic, radiologic, and genetic aspects are discussed.

A 2 years and 9 months old female patient, with the diagnosis of Weaver syndrome is reported. The proband presents persistent pre and post-natal overgrowth, asynchronic advanced bone age, particular facies, (macrocephaly, ocular hypertelorism, micrognathia, large ears), bilateral widening of the distal femoral metaphysis, bilateral tibia vara, prominent fetal fingerpads, clinodactyly, development delay, low pitched and hoarse cry, nonspecific cortical atrophy, dilation of the ventricles and vermix hypoplasia. The differential diagnosis with other overgrowth syndromes is discussed. The possibility of uniparental disomy and genetic imprinting as the basic genetic defect in the Weaver syndrome is suggested. The patient reported here appears to be the first case in the Venezuelan literature.

Human ehrlichiosis is a zoonotic disease, caused by a rickettsia that infects leukocytes. It was described for the first time in the United States of America in 1986. More than 300 cases have been reported in that country. One case has been reported in Portugal, two in France and one more in a tourist coming from Mali (Africa). In Venezuela, a tropical country, where ehrlichiosis is endemic in dogs and horses, the first case of human ehrlichiosis is reported in a seventeen month old girl. She initially had symptoms compatible with a viral illness. Then she developed a rash, acute respiratory failure, hepato-splenomegaly, neurologic abnormalities, renal failure and hematologic alterations including pancytopenia and disseminated intravascular coagulation (DIC). Different diagnoses were given before it was concluded that it was a case of ehrlichiosis. She was treated with tetracycline and very soon recovered. The initial diagnosis was made using buffy coat blood smears stained with Diff Quick Stain. Indirect Immunofluorescence (IFA) test was used to detect antibodies against Ehrlichia chaffeensis (1:126) but not to other rickettsias. Also the presence of platelets with ehrlichia bodies similar to E. platys from dogs, it was demonstrated, in peripheral blood from the child. The presence of these bodies in human platelets has not been previously reported. In this case, it could not be proved that the disease was transmitted by a tick bite. The presence of ehrlichia bodies in platelets from the girl's peripheral blood is also described.

Stroke, the 5th. cause of death in Venezuela, has been associated to cerebral infarction. However, there is little information concerning lethality factors. 33 atherothrombotic subtype stroke patients, 31 (96%) Latino and 2(4%) white, were admitted into a prospective study to analyze the role of 11 mortality risk factors for those patients. A mortality relative risk (RR) > 1.5 or < 1 (protective) was considered clinically important if 1 was excluded from the 95% confidence interval (95%CI). The Mantel-Haenszel Chi-square procedure was use to test statistical significance (p < 0.05). Mortality RR for patients age 65 and over (RR = 2.95) and 4 year mortality RR for male patients (RR = 2.04) were clinically and statistically significant. History of high blood pressure was protective (RR = 0.62) probably due to good medical control. Cumulative mortality was higher than that of comparable studies, even from the first week of follow-up, reaching 67% at the 4th year.

In 1964, Pfeiffer described a syndrome consisting of craniosynostosis, broad thumbs, broad great toes, and partial soft tissue syndactyly of the hands and feet. It belongs to acrocephalosyndactyly syndromes. We describe a male baby product of an eighth full-term uncomplicated uncontrolled pregnancy, mother and father normal and unrelated, 32 and 50 years old, respectively. He had all diagnostic and prognostic criteria of Subtype 2 Pfeiffer's Syndrome. The clinical, radiological, tomographic, and genetic aspects are discussed.

The aim of this study was to determine the association of the Gly482Ser polymorphism of the PGC-1 gene with insulin resistance and type 2 diabetes mellitus in subjects from the city of Maracaibo. The study was performed on 64 no-diabetic subjects (36 without insulin resistance and 28 with insulin resistance) and 13 with type 2 diabetes. A clinical and nutritional history was carried out and the evaluation of anthropometric parameters was included. Fasting serum glucose, fasting serum insulin, total cholesterol, HDL-C and LDL-C, were measured. The Gly482Ser polymorphism was detected by PCR-RFLP. It was found that the allelic frequencies for A and G were 0.36 and 0.64, respectively. The population was found in genetic equilibrium of Hardy Weinberg. The genotypes of the polymorphism Gly482Ser were not associated with insulin resistance and type 2 diabetes mellitus (OR = 1.320, p = 0.74; OR = 2, p = 0.47 respectively). Nevertheless, the diabetic subjects with the genotype AA presented values of LDL-C higher (p < 0.05) than the individuals with the genotypes GG and GA. The diabetics with the genotype GA showed significantly higher concentrations of triglycerides (>150 mg/dL) compared with the genotype GG. According to the results, the polymorphism Gly482Ser of the PGC-1 gene would be able to contribute to the cardiovascular risk in type 2 diabetics, while in the insulin resistant individuals, this polymorphism was not associated with cardiovascular risk factors.

The influence of Melatonin (MLT) on the modulation of the immune system has been described. In previous studies an increment of cell proliferation and an increase or a decrease of cytokines have been reported. Other workers have found inhibitory effects or no effect in the immune functions. Because of this controversy, and for the purpose of studying the mechanism by which MLT performs its functions, we evaluated its effect on murine splenocytes's proliferation after a mitogenic stimulation, and quantified the levels of IL-2 and IL-1 beta in the absence or presence of Phitohemaglutinin (PHA) in supernatants of mice splenocytes cell culture treated or not with MLT. The lymphoproliferative response was assessed using tritiated thimidine in the splenocytes of mice treated with 500 micrograms of MLT/Kg b.w. and in cell cultures containing 5, 50 and 100 micrograms MLT/mL. The production of IL-2 and IL-1 beta was detected by the ELISA test. An increase in the proliferation (p < 0.01) of spleen cells treated with 50 and 100 micrograms MLT/mL an optimal dose of PHA, was detected. The in vivo or in vitro treatment with MLT increased the levels of IL-2 and IL-1 beta in the absence or the presence of PHA, maintaining the increase in the concentration of IL-1 beta up to the to ninth day of treatment. These results suggest that MLT acts directly on cell proliferation probably by binding to high affinity receptors located on spleen cells, that stimulates the production of IL-2 and IL-1 beta giving rise to an increment of cell immunity.

To estimate the prevalence of mycoses in the Universitary Hospital "Ruiz y Páez" (Bolivar State, Venezuela) during 2002, a retrospective study was carried out. Four hundred and fifty six mycoses were diagnosed in 250,956 patients. The most frequent mycoses, the cutaneous form (94.5%), were produced by dermatophytes, Malassezia furfur and Candida spp. in 90%. Deep mycoses were detected in 4.7% and consisted of histoplasmosis (2.6%), paracoccidioidomycosis (1.7%) and cryptococcosis (0.4%). Several patients with deep mycoses presented HIV infection, tuberculosis and hematological disorders (neoplasias among them). The frequency of mycoses in the general population that attend the Hospital Universitario "Ruiz y Páez" is low, superficial mycoses are predominant, and some conditions seem to predispose to deep mycoses.

Superficial fungal diseases that affect the skin and its appendages are frequently seen in basic triage and in dermatology services. These diseases are distributed in Venezuela with an incidence of 92.9%. The aim of this study was to determine the genera and species that cause dermatomycoses in residents of Anzoátegui state, Venezuela, during the period 2002-2012. A total of 4257 patients with a presumptive diagnosis of superficial mycoses were studied, with ages from 7 months to 79 years. The overall prevalence was 30.9%. The most frequent were dermatophytosis (44.7%). M. canis produced 148 cases of tinea capitis. Three dermatophytic agents represented 95% of all cases, with a significant predominance of T. mentagrophytes with 50%. Candidosis occurred in 28.4%. C. albicans, and the C. parapsilosis complex, were responsible for 80% of the cases. The other species identified were C. tropicalis (n = 41, 11.0%), C. glabrata (n = 10, 2.7%), C. guilliermondii (n = 6, 1.6%), C. krusei (n = 4, 1.1%). Pityriasis versicolor occurred in 22.4% of the cases studied, and less frequently were present onychomycosis produced by a non dermatophytic mold: Fusarium oxysporum (n = 34, 65.4%), Aspergillus terreus (n=16, 30.8%) and Scytalidium dimidiatum (n=2; 3.8%). Rare cases of Trichosporon onychomycosis (0.5%) and one case of black tinea were also found. Health education in the population is recommended to promote measures to prevent transmission of these fungi and prevent the spread of this silent public health problem.

Malaria in pregnancy constitutes a world-wide public health problem. With the objective of studying malaria in pregnancy, a cross-sectional, descriptive epidemiological study was carried out on 449 women, in mining areas of the San Isidro parish, municipality Sifontes, state of Bolívar, Venezuela, during 2005-2006. The Malaria incidence in pregnant women was 27.4%: 87% for Plasmodium vivax, 12.2% Plasmodium falciparum and 0.8% mixed infections. These infections appeared mainly during the second trimester (41.5%). Of the women studied, 71.5% presented symptoms and 26.2% had anemia. A higher proportion of abortions occurred among infected mothers with Plasmodium vivax (3/5); and there were 3.3% low-birth-weight neonates. A case of placental malaria (0.8%) for Plasmodium vivax was registered. An association was observed between mothers receiving chemoprophylaxis and the adequate weight of newborns (chi2 = 41 23gl. p < 0.0001), independently of the regularity of treatment. It is concluded that the routine administration of antimalarial quimioprophilaxis against P. vivax to pregnant women, could be justified in endemic areas. It is advisable to establish the routine diagnosis and opportune treatment during the prenatal practice in the transmission areas of malaria.

The aim of this study was to determine the prevalence of cytomegalovirus (CMV) in pediatric patients with neurological disorders from Zulia State, Venezuela, during the period 2007-2008. Samples of cerebrospinal fluid (CSF) and serum were obtained from 186 patients with neurological symptoms and bacteriological negative CSF. The albumin CSF/serum content was determined to rule out contamination of CSF and optimal pairs were determined by ELISA of IgM and IgG anti-CMV antibodies in serum and IgG in CSF. Only 40.86% (76/186) of patients were optimal for this study. Serum samples positive for IgM antibodies (2/76; 2.6%) and IgG antibodies (71/76; 93.4%) were obtained. CSF IgG antibodies were observed in 24/76 patients (31.6%). Increased values of glucose in CSF (p < 0.05) were observed in 58.3% of CMV patients with meningoencephalitis. In addition, increased CSF protein concentration (p < 0.01) was observed in CSF anti-CMV antibodies positive patients with meningitis. This study shows high prevalence of acute CMV infection in pediatric patients with neurological affections suggesting an important role of this virus in this pathology during the studied period.

During the past two years, Investigación Clínica has undergone a substantial reduction in its funding caused by the insufficient budget allotment that the University of Zulia has received from the Venezuelan Government. The progressive increase in the number of articles contained in each issue of the journal caused its weight to exceed the established limits, affecting the distribution costs. Therefore, some adjustments to its structure and distribution are required to maintain its frequency and quality, including reducing the number of papers per issue and sacrificing free shipping to many libraries and health centers in our country and abroad. The "Instructions to Authors" will appear only in the first issue and we will keep the "Index of Authors" in the last issue of the year. Also the publishing of reprints will be limited and only will be sent to authors upon request and shipment pre-payment. Likewise, color pages fees will be canceled to the Publishers, prior to printing. For the above mentioned difficulties, we recommend our regular readers to use the website https://sites.google.com/site/revistainvestigacionesclinicas/, where all articles can be found in PDF format, as they appear in our printed edition. Despite these difficulties, all our collaborators will keep working to maintain the high standards that have characterized this journal for over 50 years, inspired by our founder, Dr. Américo Negrette.

We report two patients with trisomy 21 whose karyotypes revealed unusual translocations. In the first case there was a tandem translocation with two chromosomes 21 attached to the long arm of chromosome 10 (45,XX + tan(10:21;21). In the second case there was an inverted tandem translocation between two chromosomes 21 attached through their long arms (46,XY + dic(21q:21q). The clinical picture in both patients was not different from the usually found in trisomy 21. Since the parent's karyotypes were normal in both cases, it is assumed that both translocations arose "de novo". The need for karyotyping all cases of Down syndrome is emphasized.

APOE epsilon4 allele is associated with increased risk for Coronary Artery Disease and higher concentrations of total-cholesterol and low-density-lipoprotein-cholesterol; however, some studies could not reproduce these results. This fact suggests that other genetic or environmental factors are acting on these associations. Quantitative variations of gene expression, conferred by polymorphisms in the promoter area, as -219G/T, could play also a role as a risk factor for CAD. Since, in a previous study, we found an association between the APOE epsilon4 allele and atherosclerotic lesions in males of our population, we investigated now whether the APOE promoter polymorphism -219 G/T is also associated with the presence of atherosclerotic lesions and plasma lipid levels. Genotypes were obtained from 380 DNA samples from patients undergoing an angiography study. Logistic regression analysis showed no significant associations between T allele, or G allele, and the presence of atherosclerotic lesions. Lineal regression analysis showed association between G allele and higher TC (p = 0.002) and LDL-c (p = 0.022) levels. After stratified by sex: TC (p = 0.001) and LDL-c (p = 0.020) for males, females showed no significant differences. For cases and controls groups, the allele G has still been associated with higher levels of TC (p = 0.007, p = 0.048 respectively). No associations for T allele were observed. We conclude that G allele of polymorphism -219 on the promoter of APOE gene is associated with higher TC and LDL-c levels in males, but this polymorphism is not acting as a risk factor of CAD in our population.

Cardiac defects are the most frequent congenital malformations, with an incidence estimated between 4 and 12 per 1000 newborns. Their etiology is multifactorial and might be attributed to genetic predispositions and environmental factors. Since 1990 these types of pathologies have been associated with 22q11 microdeletion. In this study, the frequency of microdeletion 22q11 was determined in 61 patients with non-syndromic congenital heart disease. DNA was extracted from peripheral blood and TUPLE1 and STR D10S2198 genes were amplified by multiplex PCR and visualized in agarose gels. Gene content was quantified by densitometry. Three patients were found with microdeletion 22q11, representing a 4.9% frequency. This microdeletion was associated with two cases of Tetralogy of Fallot and a third case with atrial septal defect (ASD). In conclusion, the frequency for microdeletion 22q11 in the population analyzed was 4.9%. The cases that presented Teratology of Fallot had a frequency for this microdeletion of 7.4% and for ASD of 11.1%.

A study, under laboratory and field conditions, was conducted to evaluate the effectiveness, persistence in the time and some factors that can affect the larvicidal action of the Griselef formulation of the sporogenous bacteria Bacillus sphaericus strain 2362, on the larvae population of the Anopheles nuñeztovari Gabaldón, the main malaria vector in western Venezuela. The degree of susceptibility of this species to the Bacillus sphaericus was determined to be at a LD50 in 0.07 ppm a LD95 in 0.69 ppm. The pH ranges of the water, as tested in the laboratory, showed that values between 7.0 and 9.0 did not affect the action of the larvicide, producing more than 95% of mortality after 72 hours of observation. Under controlled field conditions, the high susceptibility of the An. nuñeztovari larvae to the larvicidal action of the product was demonstrated. With a dose of 5 ml/m2, a 100% mortality was obtained after 72 hours of exposure. In the field, it was determined that after 12 hours, solar radiation decreased the effectiveness of the B. sphaericus in 30% and that the presence of vegetation reduced the biolarvicidal effect between 5 and 12%. Under natural field conditions, it was shown that the larvicide was effective, since a 100% larval mortality was obtained in the two treated breeding places. This effect persisted up to 4 months of observation, with more than 85% of larvae reduction, showing that it is capable or remaining in the natural environment.

The study of serotyping of isolates of Candida albicans of clinical material obtained from different geographic areas of Venezuela suggest that serotype A is predominant over type B. These results are in relation with results obtained in other countries. Type A serotype is predominant in 57 to 100% in the areas studied. Only in 2 cities serotype B was isolated. Both serotypes of Candida albicans were observed in intertriginous, mucosal, inguinal and lung forms. These studies have allowed us to have information about the predominance of serotypes in certain areas of the country.

The Instituto de Investigaciones Clínicas "Dr. Américo Negrette" belongs to the Faculty of Medicine at University of Zulia in Maracaibo, Zulia State, Venezuela. It was created on December 4, 1959 by Dr. Américo Negrette. Today, with 55 years of existence, the Institute seeks to fulfill the mission that characterizes it, based on the values instilled by its founder and maintained by subsequent generations, whose research projects are implemented through seven research sections: Biochemistry, Hematologic Research, Neuropharmacology and Neuroscience, Immunology and Cell Biology, Clinical Neurochemistry, Parasitology and Virology. The research originated in these laboratories have become national and international points of reference, despite the current economic situation with budget deficits that put at risk the quality and originality of their projects with negative consequences on the productivity and applications for health population, reasons of biomedical research.

Investigación Clínica has been published uninterruptedly for 55 years and for this reason, the University of Zulia has recognized the work of its editorial team with the imposition of the Order "Jesus Enrique Lossada". Despite some financial and structural problems we are optimistic because our journal has been included in new international indices and it is connected to the scientific world through the contributions from all continents; by the selfless collaboration of hundreds of domestic and foreign referees who respond with great professionalism; and through the visits to our website, from virtually around the world. Reviewing the SCImago statistical analysis, we found that among the Venezuelan medical journals, Investigación Clínica is first in cites per document (2 years) and second in the H index, and compares favorably with prestigious Latin-American journals. It is noteworthy that both in Venezuela and beyond our borders, the submission of topic reviews has increased in detriment of original papers or contributions. It seems that the lack of financial support to research institutes and universities, has led to a decline in experimental projects, at least in the medical field that occupies this journal, so researchers resort to reviews in their respective fields, as a compensation to maintain their productivity. This has caused that the Editorial Board has limited the reception of reviews to keep intact the percentage of published original contributions. Finally, we would like to think that there are no obstacles that can not be overcome to maintain our excellence in publishing Investigación Clínica.

Sixty families ascertained through a single proband, has helped to better define infantile autism as a heterogeneous group of disorders. Forty four patients showed a characteristic facio- auricular dysplasia. Twenty four of these, showed increased pyruvate and lactate and laboratory findings of metabolic acidosis i.e., anion gap above 18 mEq/L or serum bicarbonate below 21 mEq/L but only nine of these probands demonstrated reduction of plasma bicarbonate below 18 mEq/lt. Plasma amino acids in 17 probands and matched controls showed increased taurine with the rest of amino acids significantly (p less than 0.05) below the control level. Glutamate and aspartate were also significantly elevated (p less than 0.05; Student t-test). Segregation analysis in thirty four of these families which linked through at least one ancestral family name, suggested autosomal recessive inheritance (p = 0.20). Three out of eight probands who received megadoses of pyridoxine (Vitamin B6), subjectively gained in language abilities, affectivity and response to behavior modification therapy. Five autistic patients proved to have clinically defined syndromes: two with the Martin-Bell syndrome, and three girls affected respectively with the Rett syndrome, phenylketonuria and dicarboxylic aciduria.

Classic pathology textbooks claim that acute splenitis reflects septic states, nevertheless, the evidence upon which that association is based remains unclear. We assessed the occurrence of acute splenitis, as an indicator of systemic infection, in 34 autopsies performed in patients in whom the cause of death was due to multiple organ dysfunction syndrome, secondary to sepsis (group A); and in 37 cases of death by non-infectious causes (group B). These necropsies were done during the period January 31, 1999-December 31, 2000, at the Pathology Department of the Hospital General del Sur "Dr. Pedro Iturbe", Maracaibo, Venezuela. Acute splenitis was observed in 79% of the cases in group A, whereas it was absent in group B (p < 0.001). Thirty three (97%) of the patients of group A did not receive antibiotic therapy, and died within the first 24 hours following admission. Our results suggest that based on a proper clinical-pathological correlation, non-specific acute splenitis constitutes a finding that reflects a septic state, at least in cases that do not receive anti-microbial therapy.

Codon 72 polymorphism of the tumor suppressor gene TP53 has been associated with a higher risk in the development of several types of cancer. The polymorphism results in a variant protein with either an arginine (CGC) or a proline residue (CCC). The aim of this study was to analyze the association of the TP53 codon 72 polymorphism with the risk of developing gastric cancer in a high-risk population from the central-western region of Venezuela. DNA was extracted from paraffin-embedded gastric adenocarcinoma biopsies (n=65) and endoscopic biopsies from chronic gastritis patients (n=87). TP53 codon 72 polymorphism was determined by PCR-RFLP from all samples. Patients with gastric cancer had a significantly higher frequency (P = 0.037) of the Arg allele than those with chronic gastritis. A logistic regression analysis suggested that Arg carrier individuals had a 4.6-fold higher risk (95% CI 1.0-21.3) of developing gastric cancer. An increment of the Arg/Arg genotype was observed in poor-differentiated gastric adenocarcinoma (OR: 3.1; 95% CI 1.0-9.2), and of the Arg/Pro genotype in well/moderate-differentiated adenocarcinoma samples (OR: 3.5; 95% CI 1.1-11.0), when comparing within the gastric cancer samples; and the last group also when contrasting it with chronic gastritis patients (OR: 2.4; 95% CI 1.1-5.2). The results of this study suggest that the carriage of the Arg allele could be associated with the development of gastric cancer in this Venezuelan population.

In the present study the effect of the attenuated strain TC-83 of the Venezuelan Equine Encephalitis virus on the nuclear transcription in brain cells of rats was assessed. The transcription activity of the DNA depending RNA polymerases (types I and II) in the isolated nuclei of brain of infected rats and controls was determinated by incorporation of the (3H) UTP. Simultaneously a viral replication curve in the brain and the serum was carried out by plaque forming method in chicken embryo cell cultures. RNA polymerase I activity was only significantly reduced after 25 hours of infection, respect to control values, while polymerase II activity was progressive and significantly diminished from inicial stages of the viral infection at 10, 15, 20 y 25 hours post-infection compared to control values. The virus was not detected in the brain but after 25 hours post-infection with very low titers (< 0.7 log10 P.F.U./ml.), while the viral presence in the blood was demonstrated after a 10 hour period. Our results demonstrated a marked effect of the attenuated strain on the brain nuclear transcription, although the presence of the virus was not detected in the brain of the infected rats. This finding suggest a mechanism of action which deserves further studies to elucidate the cerebral metabolic response and the pathogenesis of the Venezuelan Equine Encephalitis infection.

To determine whether treatment with dehydroepiandrosterone (DHEA) improves the efficiency of immunization against the Venezuelan Equine Encephalomyelitis (VEE) virus, mice were vaccinated with the TC-83 VEE virus. DHEA (10 mg/kg) was administered in a single dose, 4 hours before vaccination. IgM antibody titers were determined at days 7, 14 and 21 post-immunization. Treatment with DHEA increased antibody titers at day 14 after immunization. Mice were challenged with live VEE virus at day 21, and viral titers were plaque assayed in chicken embryo fibroblasts from days 2 to 5 post-infection. After the challenge, viremia decreased on day 2 and brain virus levels were reduced at day 4 in mice treated with DHEA. These results suggest that DHEA treatment could enhance the efficiency of immunization against VEE virus in mice.

The propositus is a two year old child with a severe hemolytic anemia and increased level of Hb F. The Hbs A, A2 and F were eluted and quantitated by cation exchange high-performance liquid chromatography (HPLC-CE). DNA was isolated from peripheral blood leukocytes by a salting-out extraction procedure. The beta globin gone was amplified and the presence of the beta thalassemia mutation was determined by PCR followed of Reverse Dot Blot. Her hematological parameters were as follows: Hb: 7.0 g/dL, Hct: 24.8%, VCM: 87.4 fl, CHCM: 27.8 fl. The haemoglobin study showed an 97% increase of Hb F and Hb A2 normal. The molecular study suggested the presence of beta(IVSII-829) mutation in trans to deltabeta Thalassemia. The propositus inherited her mother's deltabeta-thalassemia gene mutation and her father's beta(IVSH-829) mutation. This is the first time the diagnosis has been performed in a Venezuelan family at-risk of compound heterozygotes for beta-thalassemia and delta beta-thalassemia.

Cardiovascular disease is a significant health problem affecting the adult population. Because atherosclerosis may begin in childhood, the aim of the present study was to identify biochemical markers for cardiovascular risk at an early stage of life. We studied 79 adolescents (48 girls and 31 boys) whose ages ranged from 13 to 17 years. A medical history (including pubertal stage by Tanner) was obtained from each subject. Anthropometric assessment was established by height, weight, body mass index (BMI), waist and hip circumferences, skinfolds, centrality index and obesity index. After a 12-h fast, basal blood glucose levels, total cholesterol, triglycerides, LDL-C and HDL-C were determined by enzymatic methods, mean basal insulin levels by radio immunoassays and apo A1, B, CIII by turbidimetric immunoassays. According to the BMI and taking 25 Kg/m2 as the cutoff value, 35% of the girls and 16% of the boys were obese. Eighty-five percent of the girls and 58% of the boys were hyperinsulinemic (basal insulin > 12 uU/ml). Circumferences, skinfolds, centrality and obesity index were higher (p < 0.05) in boys than in girls. In both, boys and girls, basal insulin levels were higher than the cutoff insulin value for our lab (>12 microU/ml), with the girls having higher insulin levels than the boys. Apo A1 was negatively associated with the obesity index and positively with HDL-C. Apo B was related to total cholesterol and LDL-C. Apo CIII was associated with basal insulin levels, triglycerides and VLDL-C. Our results suggest that apo CIII might be a good marker for higher insulin levels, insulin resistance and cardiovascular risk in adolescents.

Mitochondrial encephalopathies are a group of diseases that have as their pathogenic basis an alteration of the mitochondrial DNA (mtDNA). The MELAS phenotype (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes) has been related to mutation A3243G in approximately 80% of the cases reported. MERRF (epilepsy myoclonus with ragged red fibers) has been related to mutation A8344G and A8566G of tRNA Lys. We report the case of a 7 months-old female with early clinical signs of encephalopathy associated to the A3243G mutation. Laboratory tests showed lactic acidosis and the EEG pattern was compatible with an encephalopathic process. The infant was treated with ACTH during one month, with clinical and electroencephalographic improvements. Currently, she is receiving treatment with B-vitamins, L-Carnitine and urinary alkalizing agents. It is concluded that an analysis of mtDNA must be made in infants who present convulsions, delay in their psychomotor development, lactic acidosis and an EEG pattern compatible with an encephalopathy, to rule out a mitochondrial disease.

Our objective was to determine the presence of chromosomal abnormalities in primary cultures of ovarian surface epithelial cells in women of different ages with no history of cancer. Throughout conventional cytogenetic techniques, we analyzed chromosome spreads of cultured ovarian epithelial cells from 10 donors who were 50 or more years old (B) and 16 controls between 20 and 49 years old (A), belonging to the mestizo population in Bogota DC, Colombia. Of the 26 cultures that were analyzed in passage 1, 61.5% had an abnormal chromosome complement (62.5% in A, and 60% in B). Abnormalities included polyploidies, endoduplications and monosomies. Deletions in chromosomes 3 and 11 were found in just one metaphase. None of the samples showed weaknesses or breakpoints. After transforming and applying the exact student's t-test for variance heterogeneity, we found significant differences in the frequency of metaphases, that were higher in A than in B (p=0.05), and in the frequency of polyploidies, which were higher in B than in A (p=0.044). Through the application of the Mann-Whitney test, we determined that the frequency of endoduplications was higher in A than in B (p=0.126), without reaching significant differences. There were no significant differences in the frequency of monosomies. The level of significance was set at p < or = 0.05. Taking into account that polyploidization is a marker of chromosomal instability and that the risk of cancer arising from the ovarian surface epithelium augments substantially after menopause, the increase in the frequency of age-associated polyploidies could be used as a predictor of ovarian cancer in women from an ethnically homogeneous population as the mestizo one in Bogota DC.

The alpha thalassaemia diseases in most cases are caused by deletions that affect one or two of the alpha genes, being less frequent the cases due to punctual mutations, insertions or deletions of a few pairs of bases, which have been denominated no deletion a thalassaemias. The objective of this investigation was to determine the incidence of the no deletion alpha thalassaemia in patients with a thalassaemia using molecular biology techniques. We studied 517 individuals of the San Carlos Hospital (Thalassemia Molecular Research Center, Madrid-Spain) between January 2001 and December 2003, in whom iron deficiency anemia had been ruled out, that presented microcytosis and hypochromia and that presented normal HbA2, HbF and EEF from normal Hbs. The two types of no deletion a thalassaemia most frequently described in the Mediterranean were studied: 1) alpha Hph due to deletion of 5bp in the IVS I and 2) alphaNco due to a change in the initiation codon of the gene. Of the 517 cases studied, 40 (7.7% of the cases) represented a no deletion alpha thalassaemia. Of these cases, 28 were positive for alphaHph of the alpha2 gene, 24 in the heterozygote state, one homozygote and three double heterozygotes associated with the 3,7 kb deletion. The remaining 12 cases were positive for the alphaNco of the alpha2 gene, 10 heterozygotes, one homozygote and one double heterozygote associated with the 4,2 kb deletion. The no deletion alpha thalassaemias represent < 8% from the cases in our environment. The alphaHph is the most frequent type of no deletion a thalassaemia and its haematological abnormalities are more manifest that the ones present in the cases of alphaNco.

Fluorescent in situ hybridization (FISH) is a rapid, sensitive and reliable method for the identification of complete chromosomes, or segments of them, during metaphase or nuclear interphase. The present study shows the results of the analysis of 32 bone marrow aspirates from patients with malignant hematological diseases (11 AML, 7 ALL, 12 CML and 2 CLL), referred to the Medical Genetics Unit of the Faculty of Medicine, Zulia University, Maracaibo, Venezuela between 1994 and 1996. All samples were studied by conventional and molecular techniques (FISH), using probes of total chromosomes, alpha-satellites and locus specific. In patients with AML and ALL and FISH technique detected clonal chromosomal abnormalities, that were not found by the conventional cytogenetic technique. Furthermore, the PML-alpha RARA complex was identified in the promyelocytic acute leukemias. The presence of the molecular complex ABL-BCR was also demonstrated in CML. The present study demonstrates the usefulness of the FISH technique in the detection of clonal chromosomal abnormalities, which are important when considering the clinical care of patients with these pathologies.

The Medical Genetic Unit of the University of Zulia (MGUUZ) has developed a Prenatal Diagnosis Program (PDP) since January-1993, in which Genetic Risk Factors are determined in couples who request prenatal genetic counseling. In this program, different prenatal diagnostic procedures are performed to detect congenital defects during intrauterine life. One of these procedures is the Fetal Sonogram (FS). FS is a non invasive technique which permits the prenatal diagnosis of many genetic dysmorphic syndromes. Through the search of abnormal specific characteristics in the fetus, chromosomopathies may be suspected. These findings are named "Echosonographic Markers of Chromosomal Abnormalities" (EMCA). During three years (January-1993 to December-1996), patients attended in the PDP included 321 pregnant women in which 312 FS were performed. Abnormal outcomes were 22 (17 with isolated congenital malformations and 5 with EMCA). Only one fetus with chromosome abnormality (46,XX21q-) could not be detected by FS. The goals of this paper are: 1) to report 5 patients with sonographic markers suggestive of chromosomal abnormalities and 2) to show the FS usefulness in prenatal diagnosis of chromosompathies. We conclude that, in the search of the EMCA the FS should be offered systematically to all pregnant women without recognizable genetic risk. They are the main group with optimal reproductive age and in consequence, with the possibility of having a relatively major number of conception outcomes with congenital defects, with or without chromosomic etiology. The majority of those defects can be detected by FS and could allow us to select the patients in which the use of an invasive prenatal diagnostic procedure could be justified.

Chagas disease is a tropical parasitic disease caused by the protozoan Trypanosoma cruzi (T. cruzi), whose reemergence as oral outbreaks is currently a public health problem in Venezuela. T. cruzi infection induces myocardial damage; which according to the microvascular theory, is derived from parasite-mediated disruption of the endothelium, inducing platelet aggregation and ischemia. In order to determine whether ventricular repolarization disorders observed in human patients are characteristic signs of the disease that can be reproduced in NMRI mice; we studied 12 patients with a well documented diagnosis of acute Chagas disease, based on epidemiological, clinical, parasitological and molecular data. Also, T. cruzi isolates from the blood of human patients from other Venezuelan geographical regions were characterized and inoculated in albino NMRI mice. A standard 12-lead and bipolar electrocardiogram configuration were done in human patients during the acute phase of the disease and in mice, after three weeks of infection. Results in human showed repolarization disorders, characterized by: negative, bimodal or biphasic T waves, ST segment depression or elevation and early repolarization. In mice a significant increase in T wave amplitude, increased QT interval duration and elevation or depression of ST segment were observed. These findings were evidenced in all infected mice, suggesting that electrocardiographic repolarization abnormalities in a well documented clinical and epidemiological context are signs that increase the sensitivity for the diagnosis of acute Chagas' disease.