[Show abstract][Hide abstract] ABSTRACT: Hereditary non-polyposis colorectal cancer (HNPCC) is clinically defined by familial clustering of colorectal cancer and other associated tumours.
By thorough molecular and clinical evaluation of 41 families, two different groups were characterised: group 1, 25 families with truncating mutations in MLH1 or MSH2 (12 novel mutations); and group 2, 16 Amsterdam positive families without mutations in these genes and without microsatellite instability in their corresponding tumours.
Significant clinical differences between these two groups were found. Firstly, earlier age of onset for all colorectal cancers (median 41 v 55 years; p < 0.001) and all tumours (median 43 v 56 years; p = 0.022) was observed, comparing groups 1 and 2. Secondly, 68% of the index colorectal cancers were localised proximally of the splenic flexure in group 1 compared with 14% in group 2 (p < 0.010). Thirdly, more synchronous and metachronous colorectal (p = 0.017) and extracolorectal tumours (p < 0.001) were found in group 1. Fourthly, a higher colorectal adenoma/carcinoma ratio (p = 0.030) and a tendency towards more synchronous or metachronous adenomas in group 2 (p = 0.084) was observed, indicating a slower progression of adenomas to carcinomas. As three mutation negative tumours revealed chromosomal instability after comparative genomic hybridisation, these tumours may be caused by one or more highly penetrant disease alleles from the chromosomal instability pathway.
These data show that HNPCC includes at least two entities with clinical and molecular differences. This will have implications for surveillance programmes and for cancer research.
Gut 12/2005; 54(12):1733-40. · 10.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominant tumor syndrome predisposing to predominantly colorectal and endometrial cancer. In 90% of the cases, molecular analyses reveal microsatellite instabilities due to germline mutations in DNA mismatch repair (MMR) genes, mainly MLH1, MSH2, among these tumors.
Tumors from 40 HNPCC index patients (31 Amsterdam positive, 9 Bethesda positive; 21 females, 19 males; mean age 48.0 +/- 13.2 years) were examined. In contrast to the classical constellation, their tumors revealed only a microsatellite stable (MSS, n=31)--or low instable (MSI-L, n=9)--tumor phenotype following the international reference panel of 5 microsatellites. No MLH1 and MSH2 mutations were detectable. Complementary microsatellites (BAT40, D10S197, D13S153, D18S58, MYCL1) were investigated by PCR and fragment analysis to find other instabilities which might hint to the MIN-pathway of the tumors.
Due to ten microsatellites in total tumors were now reclassified in 4 MSI-H (10%), 24 MSI-L (60%) and 12 in MSS (30%) phenotypes. The mean age of onset for CRCs was the lowest in the MSI-H group with 45.7 +/- 9.6 years (vs. 48.7 +/- 14.3 and 49.0 +/- 12.9 years in MSI-L and MSS group). MSI-H-and MSI-L tumors were often localized in the proximal colon (50 and 52%), whereas MSS tumors were preferentially localized in the distal colon (77%). -
Complementary microsatellites help to subdive "non-classical" HNPCC in subgroups with different clinical appearance. It allows to detect occult MSI-H tumors with up to 10% and to confirm MSS tumors who seem to have a similar biological behaviour like sporadic CRC. Maybe that this genetic reclassification influence the decision of whether to offer patients chemotherapy or not, since it is known that patients with instable tumors do not benefit from chemotherapy as well as patients with microsatellite stable tumors.
European journal of medical research 02/2005; 10(1):23-8. · 1.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Intestinal permeability can be measured by the sugar absorption test. This test is based on determining the ratio of the urinary excretion of a large and a small carbohydrate after oral administration. The aim of this study was to determine which combination of carbohydrates used in the test gives the highest correlation with disease activity in inflammatory bowel disease. 26 patients with Crohn's disease, 21 patients with ulcerative colitis and 27 healthy control subjects were included in the study. The patients with inflammatory bowel disease had either minimal or highly active disease or were in remission. Two disaccharides (lactulose: L, and cellobiose: C) and two smaller carbohydrates (rhamnose:R, and mannitol:M) were given orally and the urinary excretion was measured by high pressure liquid chromatography followed by pulsed amperometric electrochemical detection on a gold electrode. The ratios C/R, L/R, C/M and L/M were used as indicators for intestinal permeability. - There were no side effects of oral sugar administration. All patients tolerated the test well. Lactulose, rhamnose and cellobiose concentrations are easily be measured in the urine whereas mannitol measurement requires the use of an anion exchanger. This produced inconsistent results. Patients with Crohn's disease or with ulcerative colitis had increased permeability indices in comparison to healthy controls, even in remission. The L/R ratio gave a better differentiation between the healthy controls and patients with active disease than the other agents. Changes in disease activity are best reflected by use of cellobiose/rhamnose excretion quotient.
European journal of medical research 11/2004; 9(10):456-60. · 1.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant disorder predisposing to predominantly colorectal cancer (CRC) and endometrial cancer frequently due to germline mutations in DNA mismatch repair (MMR) genes, mainly MLH1, MSH2 and also MSH6 in families seen to demonstrate an excess of endometrial cancer. As a consequence, tumors in HNPCC reveal alterations in the length of simple repetitive genomic sequences like poly-A, poly-T, CA or GT repeats (microsatellites) in at least 90% of the cases.
The study cohort consisted of 25 HNPCC index patients (19 Amsterdam positive, 6 Bethesda positive) who revealed a microsatellite stable (MSS)--or low instable (MSI-L)--tumor phenotype with negative mutation analysis for the MMR genes MLH1 and MSH2. An extended marker panel (BAT40, D10S197, D13S153, D18S58, MYCL1) was analyzed for the tumors of these patients with regard to three aspects. First, to reconfirm the MSI-L phenotype found by the standard panel; second, to find minor MSIs which might point towards an MSH6 mutation, and third, to reconfirm the MSS status of hereditary tumors. The reconfirmation of the MSS status of tumors not caused by mutations in the MMR genes should allow one to define another entity of hereditary CRC. Their clinical features were compared with those of 150 patients with sporadic CRCs.
In this way, 17 MSS and 8 MSI-L tumors were reclassified as 5 MSS, 18 MSI-L and even 2 MSI-H (high instability) tumors, the last being seen to demonstrate at least 4 instable markers out of 10. Among all family members, 87 malignancies were documented. The mean age of onset for CRCs was the lowest in the MSI-H-phenotyped patients with 40.5 +/- 4.9 years (vs. 47.0 +/- 14.6 and 49.8 +/- 11.9 years in MSI-L- and MSS-phenotyped patients, respectively). The percentage of CRC was the highest in families with MSS-phenotyped tumors (88%), followed by MSI-L-phenotyped (78%) and then by MSI-H-phenotyped (67%) tumors. MSS tumors were preferentially localized in the distal colon supposing a similar biologic behavior like sporadic CRC. MSH6 mutation analysis for the MSI-L and MSI-H patients revealed one truncating mutation for a patient initially with an MSS tumor, which was reclassified as MSI-L by analyzing the extended marker panel.
Extended microsatellite analysis serves to evaluate the sensitivity of the reference panel for HNPCC detection and permits phenotype confirmation or upgrading. Additionally, it confirms the MSS status of hereditary CRCs not caused by the common mutations in the MMR genes and provides hints to another entity of hereditary CRC.
[Show abstract][Hide abstract] ABSTRACT: 70 kDa Heat shock proteins are involved in mucosal protecting reactions in the gut of patients with inflammatory bowel disease. Recently, a single nucleotide polymorphism (PstI, nucleotide 1267) was associated with intestinal perforations and formation of abscesses and fistulas in Japanese patients with Crohn's disease. Our purpose was to evaluate this phenomenon in Caucasian patients with Crohn's disease and to verify the clinical importance of this polymorphism.
61 consecutive patients with Crohn's disease and 61 healthy control persons were examined. After DNA extraction and PCR amplification spanning the PstI-site, restriction fragment length polymorphism analyses (RFLP) were performed. Homozygous and heterozygous genotypes (AA, AB, BB) were then correlated with the clinical characteristics of the patients, especially with their intestinal complications.
Intestinal perforations and formation of fistulas, abscesses and conglomerate tumors were significantly associated with allele B (p = 0.04). Patients with genotype BB showed the highest prevalence for surgical interventions (82%), whereas patients with genotype AA had the lowest prevalence (56%). Onset of disease, the need for immunosuppressive therapy and the occurrence of extraintestinal manifestations did not differ between the three genotypes. Allele A was significantly associated with combined involvement of ileum and colon.
Caucasian patients carrying the HSP70-2 PstI-polymorphism seem to have a more severe form of Crohn's disease (perforations, abscesses, fistulas, conglomerate tumors). Especially, the homozygous genotype (BB) predisposes for a clinical course with high risk of surgical intervention.
European journal of medical research 04/2003; 8(3):120-4. · 1.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Myoadenylate deaminase deficiency is the most common metabolic disorder of skeletal muscle in the Caucasian population, affecting approximately 2% of all individuals. Although most deficient subjects are asymptomatic, some suffer from exercise-induced myalgia suggesting a causal relationship between a lack of enzyme activity and muscle function. In addition, carriers of this derangement in purine nucleotide catabolism may have an adaptive advantage related to clinical outcome in heart disease. The molecular basis of myoadenylate deaminase deficiency in Caucasians has been attributed to a single mutant allele characterized by double C to T transitions at nucleotides +34 and +143 in mRNA encoded by the AMPD1 gene. Polymerase chain reaction-based strategies have been developed to specifically identify this common mutant allele and are considered highly sensitive. Consequently, some laboratories preferentially use this technique over other available diagnostic tests for myoadenylate deaminase deficiency. We previously identified a G468-T mutation in one symptomatic patient who was only heterozygous for the common AMPD1 mutant allele. In this report, nine additional individuals with this compound heterozygous genotype are revealed in a survey of 48 patients with documented deficiency of skeletal muscle adenosine monophosphate deaminase and exercise-induced myalgia. Western blot analysis of leftover biopsy material from one of these individuals does not detect any immunoreactive myoadenylate deaminase polypeptide. Baculoviral expression of the G468-T mutant allele produces a Q156H substitution enzyme exhibiting labile catalytic activity. These combined results demonstrate that the G468-T transversion is dysfunctional and further indicate that AMPD1 alleles harboring this mutation contribute to the high incidence of partial and complete myoadenylate deaminase deficiency in the Caucasian population. Consequently, genetic tests for abnormal AMPD1 expression designed to diagnose patients with metabolic myopathy, and to evaluate genetic markers for clinical outcome in heart disease should not be based solely on the detection of a single mutant allele.
[Show abstract][Hide abstract] ABSTRACT: Recombinant human interferon-a therapy of chronic hepatitis B and C is associated with the induction of thyroid dysfunction in up to 15%. Little is known about morphological changes of the thyroid gland, especially about its tissue echogenicity under this immunomodulative drug treatment.
116 patients with chronic hepatitis B or C were consecutively investigated. 53 patients qualified for treatment with interferon-a alone or in combination with ribavirin. Patients with normal serum aminotransferase levels, advanced liver cirrhosis, hepatocellular carcinoma, active intravenous drug or alcohol abusus and with focal thyroid lesions (nodes, cysts, calcifications) were excluded. Thyroid function was determined by measurements of FT4, TSH and thyroidal autoantibodies. Ultrasonography was performed before, during and after interferon-a therapy including volumetry and standardized grey scale analysis. The data were compared with values of 100 euthyroid volunteers as control group.
After six months of therapy patients differed from controls by significant TSH elevation (12.8 +/- 9.34 vs. 2.8 +/- 1.1 microU/ml, p<0.02). Six patients (11%) developed overt hypothyroidism with detectable thyroidal autoantibodies. Thyroid volume in patients was similar (13.0 +/- 4.1 ml) to that in the control group (12.6 +/- 4.7 ml). However, thyroid echogenicity of the patients was significantly lower after 6 months of therapy (21.9 +/- 2.5 grey scales) compared to the status before (25.6 +/- 2.3 grey scales) and compared to the values of controls (25.4 +/- 2.1 grey scales, p <0.002).
Beside of functional disorders interferon-alpha leads to thyroid hypoechogenicity suggesting relevant morphological changes of the organ.
European journal of medical research 07/2002; 7(6):271-7. · 1.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Management of symptomatic cholecystolithiasis is vitally influenced by dilated biliary tract and choledocholithiasis. The objectives of this prospective pilot study were to evaluate the diagnostic value of preoperative magnetic resonance cholangiography (MRC) compared to diagnostic endoscopic retrograde cholangiography (ERC) and to establish an efficient algorithm for diagnostics and treatment of choledocholithiasis.
All consecutive patients with cholecystolithiasis and dilated biliary tract proven by sonography as well as elevated liver function tests were enrolled within 12 months. Patients without evidence of bile duct calculi underwent preoperative MRC, whereas patients with choledocholithiasis immediate ERC.
58 patients (30 male, 28 female) with a median age of 59.4 years underwent preoperative MRC. In 18 patients (10 male, 8 female; median age 63.5 years) with evidence of choledocholithiasis we subsequently performed ERC and papillotomy. Bile duct stones were detected and removed after papillotomy in 10 patients, whereas calculi could not be found anymore in 8 patients. The remaining 40 patients without calculi evident on MRC were transferred to magnetic resonance tomography and ERC in case of suspected malignancy or to cholecystectomy and intraoperative cholangiography (IOC), which could definitely exclude choledocholithiasis. In comparison to ERC respectively IOC, MRC was able to detect bile duct stones with a sensitivity of 100% and a specificity of 83.3%.
Non-invasive MRC seems to replace diagnostic ERC concerning the presence of choledocholithiasis in case of cholecystolithiasis and dilated biliary tract with a high sensitivity. The preoperative ERC with stone extraction is still the therapy of choice in case of radiologically confirmed choledocholithiasis.
[Show abstract][Hide abstract] ABSTRACT: Administration of sedatives and analgetics during colonoscopy includes the risk for arterial hypotension and respiratory depression. The aim of this study was to assess whether music therapy increases patients tolerance and reduces the need of analgo-sedative premedication.
146 consecutive patients were examined in a randomized, prospective study. Colonoscopy was performed under intravenous administration with titrated dosages of midazolam and pethidin. Oxygen was given in cases of blood desaturation below values of 90%. Patients younger than 18 and older than 80 years, patients with history of partial colectomy, gastrectomy or hysterectomy and patients with colonic tumorous or inflammatory stenosis were excluded. 60 patients underwent conventional procedure (Group A), whereas 59 patients received additional music therapy (Group B). Time required to reach the cecum (examination time) was measured and the rate of successful colonoscopies was determined.
Most of the patients required sedation with midazolam in both groups (97 vs. 93%), whereas more group A patients required analgesia with pethidin than group B patients (43 vs. 31%, p<0.05). Under music therapy the rate of completed colonoscopies was higher (group A 93%, group B 98%) and examination time was significantly accelerated (group A 22.8 +/- 14.6 min, group B 16.8 +/- 11.8 min, p<0.03).
Accompanying music therapy reduces requirement of analgesia during colonoscopy, favours completion of the procedure and shortens examination time. Music therapy seems to promote safer conditions for endoscopical practice and diminishs patients discomfort.
European journal of medical research 03/2002; 7(3):131-4. · 1.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 5-8% of all colorectal cancer cases are assumed to be due to germline mutations in DNA mismatch repair genes. Mutation analysis of these genes in affected families enables one to identify subjects with an inborn susceptibility to colorectal tumorogenesis and to offer presymptomatic testing to family members at risk, provided that the mutation detected is a truncating one or a missense mutation that has either been judged as disease causing in other families or segregates with the disease and results in a microsatellite instability of the corresponding tumor. Segregation analysis within the family or microsatellite analysis of the tumor is, however, not always possible. In these cases, assessment of the relevance of the sequence variation identified is very difficult. On the other hand, discrimination between inactivating mutations and innocuous sequence polymorphisms is of extreme importance for clinical and genetic counseling of affected families. Here we report 16 rare sequence variants of the hMLH1 and hMSH2 genes including 11 different missense variations found in a cohort of 254 suspected HNPCC patients. We provide evidence, that missense variations in hMLH1 do not necessarily result in microsatellite instability of the corresponding tumor DNA. These patients would have been missed had one followed the recommendations of using only microsatellite analysis for the selection of patients at high risk of hereditary non-polyposis colorectal cancer for mutation analysis.
European journal of medical research 12/2001; 6(11):473-82. · 1.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Variceal bleeding is a major cause of mortality in liver cirrhosis. Therapeutic options include medical (vasoconstrictive/vasoactive drugs) and endoscopic (sclerotherapy/ligation) treatments. Most studies evaluating acute esophageal bleeding have included patients with both ongoing and recent bleeding. Therefore therapeutic efficacy in ongoing bleeding may not have been adequately determined in these studies. A meta-analysis was performed for two reasons: first to compare directly the various treatments in the case of ongoing bleeding, as this would not be accomplished by a single trial, and secondly, to determine the success rates of each treatment option based on a larger number of patients.
An extensive Medline search identified 13 randomized controlled trials with precise statements of the number of patients with ongoing bleeding and their clinical outcomes. All studies followed a similar design and a Q test excluded heterogeneity of the studies. Data were pooled and cumulative success rates were calculated.
Ligation appeared to be the most effective treatment (91.0 %, 95 % CI 82.4-96.3 %); it was significantly more successful than vasoconstrictive treatment (vasopressin/terlipressin 68.7 %, 61.7-75.2 %; P < 0.002, chi-squared-test) or vasoactive treatment (somatostatin/octreotide, 75.9 %, 68.1-82.6 %; P < 0.02) treatment, but was not statistically better than sclerotherapy (81.1 %, 71.7-88.4 %). The latter therapy was not statistically superior to medical treatment options. Calculations of estimated true effects, which take into account the weight of each study, rendered similar results.
Ligation is the most effective treatment option. No significant difference was found between the efficacy of sclerotherapy and treatment with somatostatin or octreotide.
[Show abstract][Hide abstract] ABSTRACT: Hereditary non-polyposis colorectal cancer (HNPCC) is one of the most common genetic diseases comprising at least 5-6% of all colorectal cancers. It is characterized by early onset and mostly right-sided tumors (proximal to the splenic flexure). Molecular analyses are useful methods for diagnosis in index patients and for the detection of risk persons in affected families. A 37-year-old female patient whose family history fulfilled the criteria for hereditary non-polyposis colorectal cancer (HNPCC) was studied using PCR and DNA sequencing for the detection of mutations in the mismatch repair genes hMSH2 and hMLH1. Additionally, literature was reviewed (MEDLINE research until 2000) concerning clinical guidelines for surveillance in HNPCC families. A new deletion of two adenosine nucleotides (190-191 del AA) at codon 64 in exon 2 of the hMLH1 gene was found. The frameshift led to a stop codon at amino acid position 75. This mutation is considered to be disease causing in the development of the colorectal cancer of this family. Six publications with detailed recommendations for the surveillance of risk persons were found in the literature. Following their guidelines, colonoscopy is recommended from 20-30 years on for members of a family who fulfills either the Amsterdam criteria or the Bethesda criteria in combination with a detection of microsatellite instability. Female risk persons should be investigated gynecologically, including a transvaginal ultrasound examination, from 25-35 years on for the early detection of endometrial or ovarian cancer. Recommendations for gastroscopy, abdominal ultrasound examination and urine analysis are not given in all publications. Genetic counseling is recommended from 18 years on for all members of affected families.
European journal of medical research 04/2001; 6(3):93-100. · 1.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A case of colonoscopy-induced hyponatraemic encephalopathy led us to study the risk of hyponatraemia after gastrointestinal endoscopy. We assessed 40 patients before and after colonoscopy. 20 gastroscopy patients served as controls. Our findings show a high incidence (7.5%) of hyponatraemia after colonoscopy, in association with raised serum concentrations of arginine vasopressin. Physicians should be aware of this complication, since it may contribute to psychological and neurological symptoms after colonoscopy.
The Lancet 02/2001; 357(9252):282-3. · 39.06 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Denaturing high-performance liquid chromatography (DHPLC) is an efficient method for detection of mutations involving a single or few numbers of nucleotides, and it has been successfully used for mutation detection in disease-related genes. Colorectal cancer is one of the most common cancers, and mutations in the genes for hereditary nonpolyposis colon cancer (HNPCC), hMLH1 and hMSH2, also involve mainly point mutations. Sequence analysis is supposed to be a screening method with high sensitivity; however, it is time-consuming and expensive. We therefore decided to test sensitivity and reproducibility of DHPLC for 71 sequence variants in hMLH1 and hMSH2 initially found by sequence analysis in DNA samples of German HNPCC patients. DHPLC conditions of the PCR products were based on the melting pattern of the wild-type sequence of the corresponding PCR fragments. All but one of the 71 mutations was detected using DHPLC (sensitivity of 97%). Running time per sample averaged only 7 min, and the system is highly automated. Thus DHPLC is a rapid and sensitive method for the detection of hMLH1 and hMSH2 sequence variants.
Journal of Biochemical and Biophysical Methods 02/2001; 47(1-2):21-32. · 2.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hereditary non-polyposis colorectal cancer (HNPCC) is a common hereditary syndrome characterized by the high incidence and early onset of colorectal cancer. The majority of the HNPCC families carry germline mutations in either the MSH2 or the MLH1 mismatch repair gene. A 46 year-old female patient whose family history fulfilled the Amsterdam criteria for HNPCC was diagnosed with undifferentiated adenocarcinoma of the transverse colon. Recognizing the Lynch 2 syndrome (the existance of multiple HNPCC related cancers in a pedigree), we used polymerase chain reaction followed by direct sequencing to screen the coding regions of both the MSH2 and the MLH1 genes for germline mutations in DNA from the patient. We detected a novel germline mutation (300-305delAGTTGA) in exon 2 of human MSH2. We noted microsatellite instability in four microsatellite loci. Immunohistochemistry showed a lack of expression of the MSH2 gene product in the tumor, suggesting that the mutation is a disease-causing mutation.
Human Mutation 08/2000; 16(1):91-2. · 5.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Intestinal ischemia is still a challenge for clinicians and requires a close interdisciplinary cooperation between internist, surgeon and radiologist. In the last years the diagnosis and therapy, classically invasive and surgical, was supplemented by duplex ultrasound and percutaneous techniques like angioplasty and stenting. A 56 year-old man from Greece presented with epigastric pain, which was intensified by food ingestion. These symptoms were caused by a stenosis of the superior mesenteric artery, which was diagnosed by duplex sonography and angiography. No blood flow was detected in the inferior mesenteric and the celiac artery. Occlusion of one internal carotid artery made the patient a poor candidate for surgery. Therefore an interventional approach was chosen. A good result was achieved by angioplasty and stent implantation. On the day after the intervention oral food intake was possible without any pain. 18 months after the intervention the patient was free of abdominal symptoms. Therapy of mesenteric ischemia by percutaneous angioplasty and stenting is published only in case-reports and small series. Therefore the indication is mainly restricted to patients with a high risk for a surgical intervention.