Helicobacter pylori-CagA seropositivity and nitrite and ascorbic acid food intake as predictors for gastric cancer

A hospital-based case-control study was carried out between 1994 and 1996 to evaluate the risk of gastric cancer (GC) according to Helicobacter pylori-CagA (+) seropositivity, nitrite and ascorbic acid intake. Three geographical areas of Mexico were selected on the basis of their contrasting dietary patterns and H. pylori seroprevalence. Nitrite and ascorbic acid consumption were estimated by interview among 211 cases and 454 matched controls. Serum antibodies against IgG H. pylori and CagA were detected by immunosorbent assays. The adjusted risk for GC was significantly higher among CagA+ subjects compared with those that were CagA negative (Odds Ratio (OR)=2.04 95% Confidence Interval (CI) 1.37-3.02 P for trend P < 0.001), this effect remained significant among diffuse GC cases (OR 2.05 95% CI 1.25-3-36). No significant effects due to nitrite and ascorbic consumption or interactions of these nutrients with CagA seropositivity were detected. Seropositivity to H. pylori CagA+ strains may be an independent factor for diffuse GC in Mexico.     

Teaching Humanities at the National University of la Plata, Argentina.

In this article the author begins by giving a brief history of medical education in Argentina, then provides some background information on the National University of La Plata. He describes two major initiatives at La Plata: a new and pioneering admission policy (implemented in 1993) and a change in the number of hours and years in the curriculum. He then looks back to the introduction in 1976 of La Plata's medical humanities program. Over its 20 year existence, the program has undergone a number of changes in response both to students' interests and financial concerns. The revised humanities curriculum now consists of four elective courses: medicine and literature, anthropology, history of medicine, and "medical kalology" (which focuses on music and dance). Unfortunately, the program, while it has been well received by both students and faculty and has inspired programs at other Argentinean schools, is threatened by Argentina's economic crisis.     

Preoperative Endoscopic Sphincterotomy and Laparoscopic Cholecystectomy for the Management of Cholecystocholedocholithiasis: 10-Year Experience

Abstract No procedure has yet been identified as the “gold standard” for the detection and treatment of common bile duct stones (CBDS) in patients undergoing laparoscopic cholecystectomy (LC). This prospective study involves 2137 patients undergoing elective laparoscopic cholecystectomy. The algorithm for diagnostic management in place until July 1997 involved routine intravenous cholangiography and selective endoscopic retrograde cholangiography (ERC). Subsequently, assessment of the bile duct was not routinely performed, but a scoring system was applied to single out those patients at risk of CBDS who should undergo intravenous cholangiography and/or ERC (see Fig. 2). Whenever bile duct stones were found, endoscopic sphincterotomy (ES) was performed, and LC was performed with a standardized four-cannula technique after endoscopic bile duct stone clearance. Common bile duct stones were suspected in 340 patients who were referred for preoperative ERC; 250 patients were referred for ES; 21 patients were referred for open surgery because of failure of ERC or sphincterotomy. Common bile duct stones, detected in 283 cases (13.2%), were removed before surgery in 250 cases (88.3%) and during surgery in 28 cases (9.9%). Self-limited pancreatitis occurred in 4.2% of the patients after sphincterotomy. Laparoscopic cholecystectomy was performed in 98.4% of the cases. The conversion rate was 8.3% if sphincterotomy had been performed previously and 3.4% after standard laparoscopic cholecystectomy (p < 0.001). The morbidity rate was 4.5%; mortality, 0.09%. During follow-up five patients (0.2%) had retained stones endoscopically treated. Future trials of novel strategies for detecting and treating CBDS should compare the results of novel strategies with those of the strategy employed in this study, which includes selective ERC, preoperative ES, and LC.     

Risk factors for poor renal prognosis in children with hemolytic uremic syndrome

Many factors have been proposed as predictors of poor renal prognosis in children with hemolytic uremic syndrome (HUS), but their role is still controversial. Our aim was to detect the most reliable early predictors of poor renal prognosis to promptly identify children at major risk of bad outcome who could eventually benefit from early specific treatments, such as plasmapheresis. Prognostic factors identifiable at onset of HUS were evaluated by survival analysis and a proportional hazard model. These included age at onset, prodromal diarrhea (D), leukocyte count, central nervous system (CNS) involvement, and evidence of Shiga toxin-producing Escherichia coli (STEC) infection. Three hundred and eighty-seven HUS cases were reported; 276 were investigated for STEC infection and 189 (68%) proved positive. Age at onset, leukocyte count, and CNS involvement were not associated with the time to recovery. Absence of prodromal D and lack of evidence of STEC infection were independently associated with a poor renal prognosis; only 34% of patients D^–STEC^– recovered normal renal function compared with 65%–76% of D⁺STEC⁺, D⁺STEC^– and D^–STEC⁺ patients. In conclusion, absence of both D and evidence of STEC infection are needed to identify patients with HUS and worst prognosis, while D^– but STEC⁺ patients have a significantly better prognosis.     

Long-Term Results of Subtotal Colectomy with Antiperistaltic Cecoproctostomy

Purpose. To evaluate the clinical role of subtotal colectomy with cecorectal anastomosis (CRA) and its postoperative results, based on our surgical experience. Methods. We retrospectively analyzed 26 patients who underwent subtotal colectomy with CRA during an 8-year period (1992–1999) in our university hospital. The indications for CRA were intractable constipation, colon tumors, diverticulitis, Crohns disease, and postactinic colitis. CRA was performed using a new technique of end-to-end antiperistaltic anastomosis. Postoperative and late complications, and functional results, defined as the number of bowel movements per day and quality of life, were evaluated. Results. None of the patients experienced postoperative or late complications. Two patients died from progression of colon cancer. The mean follow-up period was 4.5 years (range 1–8 years). By 1 month after surgery, 58% of the patients were passing frequent bowel movements, and by 1 year after surgery, only 23% of the patients were passing frequent bowel movements. The last follow-up revealed a mean 1.7 bowel movements per day, and only one patient was taking medication for diarrhea. All patients were satisfied with the results of their surgery and reported that their quality of life was good or improved, and even very good in six cases. Conclusions. Subtotal colectomy with our new CRA technique is appropriate for treating inflammatory diseases of the bowel, colon tumors, and intractable constipation in selected patients.     

Activation and proliferation of T lymphocyte subpopulations in patients with brucellosis

BACKGROUND: T-cell proliferation is a standard method to evaluate cellular immune responses against intracellular infectious agents. The present study was undertaken to look for expression of an early activation marker (CD69) and proliferation using a nonradioactive method to evaluate cellular immune response against a salt-extractable antigen from Brucella melitensis 16M (RCM-BM) in patients suffering from brucellosis. METHODS: Expression of CD69 on membrane of CD4+ and CD8+ T-cells was determined by flow cytometry. Lymphoproliferation was determined by tritiated thymidine and 5-bromo-2'-deoxyuridine (BrdU) incorporation using liquid scintillation counter or flow cytometry, respectively, to evaluate DNA synthesis. RESULTS: Thirty healthy donors and 24 patients suffering from brucellosis were included in this study. In all cases, incubation with mitogen induced expression of CD69 and proliferation of both CD4+ and CD8+ T-cells. In contrast, only brucellosis patients responded with expression of CD69 and proliferation against RCM-BM antigen from Brucella melitensis (p < 0.001). CONCLUSIONS: Methods used in this study were useful to evaluate immune response against specific antigen or polyclonal stimulation. CD4+ and CD8+ T cells from patients became equally activated and proliferated in response to RCM-BM antigen. Our data suggest that both T-cell subpopulations play an important role in immune response against Brucella.     

Acute human immunodeficiency virus replication causes a rapid and persistent impairment of Vgamma9Vdelta2 T cells in chronically infected patients undergoing structured treatment interruption

T cells expressing Vgamma9Vdelta2 display lytic and proliferative responses against human immunodeficiency virus (HIV)-infected cells and release antiviral soluble factors. Chronic HIV-positive patients have deep changes in the composition and function of the circulating gammadelta T cell pool that are restored by highly active antiretroviral therapy (HAART). gammadelta T cells were analyzed during the rapid plasma HIV RNA rebound in HIV-infected patients undergoing structured treatment interruption (STI). A loss in circulating Vgamma9Vdelta2 T cells was observed, indicating that acute HIV replication may influence Vgamma9Vdelta2 homeostasis. These cells were lost among CD45RA(-)CD27(-) Vgamma9Vdelta2 T cell effectors, and a significant unresponsiveness, measured as antigen-driven interferon-gamma production, was observed during STI. After HAART resumption and consequent inhibition of HIV replication, Vgamma9Vdelta2 T cell reactivity was restored both quantitatively and functionally. These observations indicate that Vgamma9Vdelta2 T cells are activated early after active HIV replication but are rapidly lost when viremia is not controlled.