L Uscanga

Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Tlalpam, The Federal District, Mexico

Are you L Uscanga?

Claim your profile

Publications (79)85.17 Total impact

  • Pancreas 08/2014; 43(6):971-972. · 2.95 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To follow up patients with pseudotumoral chronic pancreatitis (PCP) to assess their outcome and identify an optimal surveillance interval.
    World journal of gastroenterology : WJG. 07/2014; 20(26):8612-6.
  • L Uscanga
    Revista de gastroenterologia de Mexico 08/2012; 77S1:32-34.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Few studies compare the direct impact of pancreatoduodenectomy (PD) on the patient's quality of life (QOL). The effect of PD in QOL, comparing the preoperative vs. postoperative status, was analyzed. A prospective single-center study was performed. PD patients in a 2-year period were included. A general QOL instrument was applied preoperative, 1, 3, 6, and 12 months after surgery and compared with national norms. Thirty-seven patients were recruited. Twenty of 37 were female. Ampullary carcinoma 14/37, ductal adenocarcinoma in 9/37, and other malignant neoplasms 14/37 were diagnosed. Mortality was absent; 48.6% had complications, 13.5 % required reoperation. Three (median) and 4 (mode) questionnaires were answered per individual. 85 % answered the last questionnaire. 4/37 had cancer related death before a year. Median follow-up was 29 (3-72) months. QOL diminished a month after surgery, physical function (67 vs 40, p<0.0001) and emotional role (37 vs 17, p<0.032) did so significantly. Three months after surgery QOL improved yet not significantly. Six and 12 months postoperatively, physical role (9 vs 49, p=0.001), physical pain (51 vs 71, p=0.01), social function (52 vs 63, p=0.014), vitality (54 vs 64, p=0.018), and emotional role (41 vs 69, p=0.006) improved significantly. PD has a favorable impact in quality of life as demonstrated by the improvement of most parameters assessed in the postoperative period.
    Journal of Gastrointestinal Surgery 05/2012; 16(7):1341-6. · 2.36 Impact Factor
  • Source
    01/2012; , ISBN: 978-953-307-811-3
  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction: Despite the fact that the frequency of hypolactasia and lactose intolerance is similar in both chronic idiopathic ulcerative colitis patients and the general population, the elimination of dairy products from the patient's diet is a habitual recommendation. Hypolactasia is common in Mexico, but its relation to chronic idiopathic ulcerative colitis has not been established. Aims: To evaluate lactose digestion and lactose intolerance in persons with chronic idiopathic ulcerative colitis. Material and methods: Thirty-nine patients with confirmed chronic idiopathic ulcerative colitis diagnosis were included in the study (mean: 31 years, range: 15 to 38). Twenty-two patients presented with rectosigmoid involvement and the remaining patients with pancolitis. No patient showed inflammatory activity according to the Truelove-Witts criteria and all consumed dairy products before diagnosis. A prospective, controlled, double-blind, cross-over study was designed. Patients randomly received 12.5 g of lactose or maltose in 250 cc water- each test 72 hours apart - and ydrogen was measured in exhaled air before disaccharide ingestion and then every 30 minutes for 3 hours. Digestion was considered deficient when there was an increase in hydrogen of at least 20 ppm. Symptom intensities were evaluated by Visual Analog Scales before, during, and after the hydrogen test. Differences between the groups were contrasted with the Mann-Whitney U and the Wilcoxon tests. Results: Eighteen patients (46%) presented with deficient lactose digestion. No significant differences were found in the symptoms, extension, or progression of chronic idiopathic ulcerative colitis between patients that could digest and those that could not digest lactose. No patient had symptom exacerbation with the disaccharides used. Conclusions: Lactose digestion deficiency frequency is similar in subjects with chronic idiopathic ulcerative colitis and in healthy individuals in Mexico. We do not know whether higher doses could have some effect, but symptoms in patients with inactive chronic idiopathic ulcerative colitis were not modified using 12.5 g of lactose/day.
    Revista de gastroenterologia de Mexico 01/2012; 77(1):26-30.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Autoimmune pancreatitis is part of the spectrum of IgG4-associated diseases. Its diagnostic criteria and histological subtypes have been formally proposed recently and although based on current data it has been suggested that there are differences in clinical presentation among populations, more research is needed to properly establish if this heterogeneity exists. In this paper, we describe 15 cases of autoimmune pancreatitis diagnosed at a Mexican centre of reference, all of them associated to the lymphoplasmocytic sclerosing pancreatitis variant. The mean age at the onset of symptoms was 47.5 ± 14.4 years, and 53% of patients were male. The main manifestations were weight loss (87%), obstructive jaundice (53%), and acute (27%) and chronic (27%) pancreatitis. Only 20% of patients had high IgG4 serum levels at the time of diagnosis. All patients receiving prednisone responded favourably, both in their pancreatic and extrapancreatic manifestations. Clinical manifestations of Mexican patients showed certain differences with respect to those usually reported.
    ISRN rheumatology. 01/2012; 2012:164914.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Heterotopic pancreas is defined as ectopic pancreatic tissue without vascular or anatomic continuity with the normal pancreas. The spleen is a rare site of origin. This case report describes a patient with a malignant insulinoma which originated from an intrasplenic heterotopic pancreas. A 46-year-old man with three previous episodes of neuroglucopenic and adrenergic symptoms was referred to our hospital. A fasting test was performed and discontinued due to hypoglycemic symptoms. Preoperative studies failed to demonstrate any pancreatic lesions. However, a heterogeneous encapsulated tumor in the spleen was found on MRI. During surgery, only the splenic tumor was found, with neither vascular nor anatomical connections to the normal pancreas. Pathology reported a malignant insulinoma. Insulin and proinsulin were documented by immunohistochemistry. After one year of follow up, the patient is free of symptoms and no recurrent disease has been documented. Only seven cases of splenic heterotopic pancreas have been reported, six with cystic mucinous neoplasms. In addition, only one case of a malignant insulinoma arising from heterotopic pancreas has previously been described. This is the second case reported of an insulinoma arising from heterotopic pancreas and the first to originate from intrasplenic heterotopia.
    JOP: Journal of the pancreas 02/2009; 10(3):321-3.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Improving the outcome of acute pancreatitis through prognostic markers has been a matter of ample research. We evaluate the clinical usefulness of four serum markers in comparison to Ranson's score. Serum measurements of C-reactive protein (CRP), interleukin-6, -10 (IL-6, IL-10), and pancreatitis-associated protein (PAP) were performed. The usefulness of each marker for predicting severity was compared with that of Ranson's score. Time of evolution was considered for improving their usefulness. Seventy-one patients were studied. Severe cases had higher levels of all markers, although only IL-10 had better accuracy than Ranson's. In patients admitted during the first 48 h, IL-6, IL-10, and PAP had improved accuracy over Ranson's; however, after this time frame, only CRP outperformed Ranson's score. Analysis of time frames improved the accuracy of all markers. Therefore, time of evolution should be considered when using these parameters for a better prognosis.
    Digestive Diseases and Sciences 01/2009; 54(10):2282-7. · 2.26 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To analyze data in a single institution series of pancreaticoduodenectomies (PD) performed in a 7-year period after the transition to a high-volume center for pancreatic surgery. PD has developed dramatically in the last century. Mortality is minimal yet complications are still frequent (around 40%). There are very few reports of PD in Latin America. Data on all PDs performed by a single surgeon from March 2000 to July 2006 in our institution were collected prospectively. During the study's time frame 122 PDs were performed; 84% were classical resections. Mean age was 57.9 years. Of the patients, 51% were female. Intraoperative mean values included blood loss 881 ml, operative time 5 h and 35 min, and vein resection in 14 cases. Both ampullary and pancreatic cancer accounted for 34% of cases (42 patients each), 5.7% were distal bile duct and 4% duodenal carcinomas. Benign pathology included chronic pancreatitis, neuroendocrine tumors, cystic lesions, and other miscellaneous tumors. Overall operative mortality was 6.5% in the 7-year period, 2.2% in the later 5 years. There was a total of 75 consecutive PDs without mortality. Of the patients, 41.8% had one or more complications. Mean survival for pancreatic cancer was 22.6 months and ampullary adenocarcinoma was 31.4 months. To our knowledge, this is the largest single surgeon series of PD performed in Latin America. It emphasizes the importance of experience and expertise at high-volume centers in developing countries.
    Journal of Gastrointestinal Surgery 04/2008; 12(3):527-33. · 2.36 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Patients with inflammatory bowel disease have an increased risk of thrombosis. Hyperhomocysteinemia is one of the factors that have been related to thromboembolic complications. Patients with hyperhomocysteinemia and normal fasting homocysteine levels can be identified with an oral methionine load. We studied homocysteine levels in patients with IBD during fasting and after methionine load to determine the true prevalence of hyperhomocysteinemia and its relation with thrombotic events. Prospective analysis of homocysteine levels in consecutive patients with IBD during fasting and 6-8 hours after an oral methionine load. Levels of folate and vitamin B12 were also determined. History of thrombotic events were recorded. Eighty-two patients with IBD, 56 with UC and 26 with CD were included. Eighteen patients (22%) had hyperhomocysteinemia during fasting. Mean levels of homocysteine after methionine load were 20.4 +/- 18.1 micromol/l (range, 1-79.7 micromol/l), and 43 patients (52%) had hyperhomocysteinemia (> or =20 micromol/l) after methionine load. Six patients (7.3%) had history of thrombosis. The homocysteine levels during fasting and after methionine load were significantly higher in patients with thrombotic events than in patients without thrombosis (15.5 +/- 3.7 micromol/l vs. 6.6 +/- 6.5 micromol/l; P = 0.002; 44.5 +/- 20.9 micromol/l vs. 18.4 +/- 16.5 micromol/l; P < 0.001, respectively). There is a higher prevalence of hyperhomocysteinemia in IBD patients than previously thought, this can be identified with an oral challenge of a methionine load. Hyperhomocysteinemia increases the risk of thromboembolic complications in patients with IBD.
    Inflammatory Bowel Diseases 03/2008; 14(3):383-8. · 5.12 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Pyoderma gangrenosum is one of the most severe extraintestinal manifestations in patients with ulcerative colitis (UC) and Crohn s disease. This lesion is frequently located on the lower extremities and the torso. Peristomal pyoderma gangrenosum (PPG) is extremely rare. We report the first published patient with PPG and UC in Mexico. PPG occurred six weeks after restorative proctocolectomy. Diagnosis was performed by clinical presentation and biopsy. Ulcer resolution was achieved with oral steroids and local wound care. Patient did not show any recurrence at one year follow-up. We suggest suspecting this illness in all patients with UC who had a restorative proctocolectomy and present difficult management peristomal ulcers. KEY WORDS: Peristomal pyoderma gangrenosum, stoma, ulcerative colitis, proctocolectomy.
    Revista de gastroenterologia de Mexico 01/2008; 73(2):89-92.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Recent studies have shown that celiac disease (CD) could affect 0.5% to 3% of the general population, including Mexican Mestizos, which represents a complex mixture of genetics, and constitutes the core of Mexican and Latin American populations. However, the association between CD and other conditions, specifically type-1 diabetes mellitus, in this population remains unknown. Thus, our aim was to determine the prevalence of both serologic and biopsy proven CD in Mexican Mestizo adults with type-1 diabetes. Over a 6-month period, serum samples obtained from consecutive Mexican Mestizo adult patients (age >or=18 y) with type-1 diabetes were tested with a new generation human recombinant protein based IgA tissue transglutaminase enzyme-linked immunosorbent assay commercial kit. All patients with positive serologic test results underwent upper gastrointestinal endoscopy and small intestinal biopsies to confirm CD. Eighty-four type-1 diabetic patients were included (62 women, mean age 28.9+/-9 y). Overall, 9 patients (9/84) were positive for IgA tissue transglutaminase with a point prevalence of 10.7% (95% CI, 4%-17%). Seven patients agreed to undergo endoscopy. Five subjects had biopsy-proven CD (5.9%, 95% CI, 1.9%-13.3%). One patient had chronic diarrhea and other abdominal bloating; whereas the remaining 3 were asymptomatic. CD associated type-1 diabetic patients tended to have higher hemoglobin A1c levels (P=0.07), reflecting poor glycemic control. As in other populations, we demonstrated a high prevalence of biopsy-proven CD (5.9%) among Mexican Mestizo patients with type-1 diabetes. Clinicians should be aware of this common association in this ethnic group.
    Journal of Clinical Gastroenterology 01/2008; 42(5):460-5. · 3.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Recurrent acute pancreatitis (RAP) represents a diagnostic and treatment challenge. Although it's real frequency is difficult to establish some works have reported 25-60% prevalence. In most, the etiology is recurrent biliary stones untreated or consumption of alcohol. The information we have about the RAP in our midst is scarce. To review the clinical characteristics and follow-up of a group of patients with RAP. Clinical charts of all patients with AP admitted to our Institute from January 1, 1995 to December 31, 2005 were reviewed. The diagnosis of RAP was established when two o more episodes of AP were documented. In each case clinical, biochemical, imaging, treatment and follow-up until the last visit to our hospital was analyzed. The diagnosis of AP was established in 406 patients. Forty of them had RAP (9.8%). Mean age was 32 years old (13-63). The majority was male (72.5%). A mean of 3.5 episodes of AP was presented for each subject (2-14). High levels of triglycerides (n = 15), alcoholism (n = 11) and gallstones (n = 8) were the most frequent cause of RAP. In some cases more than one factor was presented. In 5 of the 15 subjects with RAP due to hypertriglyceridemia other causes of AP were identified (two alcohol consumption,two idiopathic chronic pancreatitis and one gallstone disease). In three patients with RAP supposedly secondary to alcohol, gallstone disease was diagnosed during the follow-up. All of them were operated on. One has had four events of AP after the cholecistectomy. Four of the 8 subjects submitted to cholecistectomy for RAP associated to gallstone disease have had new episodes of AP: 2 for triglycerides and in two a chronic pancreatitis was diagnosed by endoscopic ultrasound or MRI. Two patients died (5%). This series represents probably the first analysis that exists on PAR in Mexico. The frequency found was 9% and the most common causes were hypertriglyceridemia, chronic alcohol consumption and gallstones.
    Revista de gastroenterologia de Mexico 01/2008; 73(2):68-74.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Intraepithelial lymphocytes (IELs) phenotyping has emerged as a useful test in intestinal pathology. In celiac disease (CD), a permanent and marked increase of gammadelta+ IELs has been described. However, there is a lack of knowledge about this peculiar IELs population in other intestinal pathologies. To analyze the percentage of IELs, specifically gammadelta+ IELs subset, present in duodenal mucosa biopsies from patients with CD and compare it with those obtained from patients with small intestinal bacterial overgrowth (SIBO) or irritable bowel syndrome (IBS). Twelve patients with untreated CD, 8 patients with SIBO, and 10 patients with diarrhea-predominant IBS were evaluated. All subjects underwent upper endoscopy for mucosal biopsy and jejunal aspirate. From 2 small bowel biopsies, intraepithelial cells were isolated and labeled with the following monoclonal antibodies CD103-PE (phycoerythrin), CD3-FITC (fluoresecein isothio-cynate), CD-7R-PE, CD45RO-APC (allophycocyanin), and TcR gammadelta-FITC. Flow cytometry analysis was performed on a standard FACScan. Total and IELs subset counts were expressed as percentage. Mean total IELs percentage was 16.7+/-6% in IBS, 25.4+/-17% in SIBO, and 26+/-13% in CD patients (P=0.2). CD and SIBO patients, had significantly higher percentages of gammadelta+ IELs (15.7+/-13% and 14.6+/-8%) than IBS subjects (4.1+/-2.5%, P<0.05). There was no difference between CD and SIBO (P=0.6). An increased density of gammadelta+ IELs is typical, but not specific for CD. A similar increase was observed in subjects with SIBO. Our findings suggest that this unique T-cell population might have a key role against intestinal bacterial infections.
    Journal of Clinical Gastroenterology 08/2007; 41(7):671-6. · 3.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although pancreatic necrosis classifies acute pancreatitis (AP) as severe, many patients with tomographic evidence of necrosis never develop systemic complications. Our aim was to analyze the incidence of pancreatic necrosis, organ failure (OF), and the relationship between them. Medical records from 165 patients with a first AP episode and in whom a contrast-enhanced computed tomography (CECT) was performed were analyzed. Pancreatic necrosis was diagnosed as non-enhancing areas of the pancreas on the CECT and was graded as <30%, 30%-50%, and >50%. Pancreatic infection was assessed by guided percutaneous aspiration. Organ failure was defined according to the Atlanta criteria. Of 165 patients (mean age 42 years, 85 men), 54 (33%) had pancreatic necrosis. Necrosis was graded as <30% in 25 subjects (46%), 30%-50% in 16 (30%), and >50% in 13 (24%). Pancreatic infection was diagnosed in 14 cases (26%). Organ failure occurred in 49 patients: in 20 patients (37%) with necrosis, and in 29 patients (26%) without necrosis (P = 0.20). Extensive pancreatic necrosis (>50%) (P < 0.05) and infected necrosis (P < 0.05) were significantly associated with OF. Eight patients, all of them with OF, died. In 6 of these cases infected pancreatic necrosis was present. Patients with pancreatic necrosis are not necessarily at risk of developing OF. However, it should be considered an important risk factor when the necrotizing process compromises more than 50% of the gland and is infected.
    World Journal of Surgery 01/2007; 30(12):2227-33; discussion 2234-5. · 2.23 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In North America and Europe, the prevalence of celiac disease (CD) might be much greater than expected in previous estimates. Until recently, the prevalence of CD in Latin America remained largely unknown. So far, information regarding CD in Mexico is limited, and it is still considered a rare disease. Our aim was to determine the prevalence of tTGA in a large group of apparently healthy blood donors. Serum samples from 1009 consecutive blood donors, who attended a third level referral center in Mexico City, were collected between June 2004 and December 2004. Only Mexican Mestizo individuals were included. All sera were tested with a new generation human recombinant protein based tTGA-IgA ELISA commercial kit (Aeskulisa tTG-IgA, Wendelsheim, Germany). The cut-off value provided by the manufacturer was 15 U/mL. The mean age of the blood donors was 34+/-10 years and 68% (n=683) were men. Six hundred fifty two subjects (65%) were born in Mexico City; and from the remaining 357 subjects, at least one was born in each of the 31 different states in our country. Twenty-seven (2.7%) blood donors were positive for tTGA-IgA; all of them with tTGA-IgA values above 30 U/mL (range 36 to 1639). Overall prevalence was 1:37 [27/1009, 95% confidence interval (CI)=1.6-3.7]. The prevalence among women was 1:33 (10/326, 95% CI=1.04-5.09) and for men 1:40 (17/683, 95% CI=1.24-3.73). On the basis of a well-recognized serologic screening method performed to blood donor samples, we demonstrated an unexpectedly high prevalence of tTGA positivity (2.6%) in the adult Mexican Mestizo population. Thus, the prevalence of CD in Mexico could be higher or similar to that observed in other countries. This observation contributes to increase the awareness for this under diagnosed disease in clinical practice and to consider CD as a global health problem.
    Journal of Clinical Gastroenterology 10/2006; 40(8):697-700. · 3.20 Impact Factor
  • Luis Uscanga
    Revista de gastroenterologia de Mexico 09/2006; 71 Suppl 1:19-21.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To assess the prevalence and clinical value of p-ANCA in a sample of Mexican ulcerative colitis (UC) patients. In a prospective, IRB-approved protocol, p-ANCA was determined in 80 patients with UC (mean age, 32 +/- 12.9 years). The severity and extension of disease were determined by clinical methods, searching a statistical association with p-ANCA status. p-ANCA were detected in 41 (51%) patients. Severity of disease was the only clinical variable statistically associated with their presence (P < 0.0001; OR = 9; CI 95% = 3.2-24.7). The prevalence of p-ANCA was similar to that reported in other countries. Their presence was associated to UC severity, but offered no more information than the obtained by clinical methods.
    World Journal of Gastroenterology 06/2006; 12(21):3406-9. · 2.55 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To describe the clinical and histological characteristics of a group of adults with small-bowel nodular lymphoid hyperplasia (NLH). Patients were searched for five years in pathology records of our institution. The biopsy material was reassessed using strict histopathological criteria. Clinical data were obtained from medical records. Small-bowel NLH was diagnosed in 18 cases. The female: male ratio was 2:1. The most frequent symptoms were diarrhea (72%), involuntary weight loss (72%) and abdominal pain (61%). Nine patients (50%) had immunodeficiency. Small-bowel bacterial overgrowth was found in three (17%) cases. At small-bowel NLH diagnosis, three (17%) had associated lymphoma: two intestinal and one extra-intestinal lymphomas. In two patients with villous atrophy and anti-endomysial antibodies the diagnosis of celiac disease was established. Giardia lamblia infection was found in only one patient with hypogammaglobulinemia (Herman's syndrome). NLH is uncommon in adult patients. Associated diseases are immunodeficiency and lymphoid tissue malignancies.
    World Journal of Gastroenterology 04/2006; 12(12):1945-8. · 2.55 Impact Factor

Publication Stats

412 Citations
85.17 Total Impact Points


  • 1985–2014
    • Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán
      • Department of Immunology and Rheumatology
      Tlalpam, The Federal District, Mexico
  • 2007
    • Universidad Nacional Autónoma de México
      • School of Medicine
      Mexico City, The Federal District, Mexico