IgG subclasses against Helicobacter pylori isolates: an important tool for disease characterization.

Helicobacter pylori infects around 50% of the world's population and is associated with diverse pathologies. In the most severe cases, the bacterium causes peptic ulcers and gastric cancer. The interplay between H. pylori and the host's immune response may help to determine the specific outcome of the infection. To study the relationship between antibody subclasses and variation in immune recognition, we determined the immunoglobulin G1 and 2 (IgG1 and IgG2) titres of sera obtained from patients with different H. pylori-associated pathologies. IgG1 and IgG2 titres were determined by ELISA in 44 sera of patients with different H. pylori-associated diseases (peptic ulcer, bleeding peptic ulcers, gastric cancer and dyspepsia). Soluble proteins from lysates were obtained from 12 different clinical isolates from similar associated diseases. We found that soluble proteins from lysates of H. pylori strains (SPLHP) recognition patterns in these sera were highly variable. Overall, IgG2 titres were higher than the IgG1 titres in the infected patients. In particular, those with peptic ulcers showed marked elevation in IgG2/IgG1 ratios, while SPLHPs from dyspeptic patients resulted in high IgG1 titres. Our results reveal that correlation of antibody subclass titres with Th1/Th2 markers may aid pathology characterization and show a potential diagnosis that could be formally evaluated in other studies.

Consenso chileno de manejo de fármacos antiepilépticos en algunos síndromes electro-clínicos y otras epilepsias en niños y adolescentes / Chilean consensus on the use of antiepileptic drugs in electro-clinical syndromes

Por iniciativa de tres instituciones: Liga Chilena contra la Epilepsia (LICHE), Sociedad de Epileptología de Chile (SOCEPCHI) y Sociedad de Psiquiatría y Neurología de la Infancia y Adolescencia (SOPNIA) de Chile, se constituye un comité de trabajo que convoca a un consenso de uso de fármacos antiepilépticos (FAEs) en un grupo de 16 Síndromes electro-clínicos y otras Epilepsias en niños y adolescentes. Cuarenta y dos médicos neuropediatras especialistas en Epilepsias de todas las regiones de Chile, participaron en la discusión y realizaron una propuesta de tratamiento farmacológico para cada cuadro. El comité de trabajo realizó un análisis exhaustivo y discusión de los documentos, para finalmente concluir en una recomendación de tratamiento para cada cuadro. Este consenso es una guía práctica de orientación para ayudar a las decisiones de tratamiento en situaciones clínicas concretas. Su objetivo final es ofrecer una mejor calidad de atención a los niños y adolescentes con epilepsias, a través de decisiones fundadas que contribuyan a disminuir la variabilidad de las decisiones terapéuticas.

Committed by three institutions: Liga Chilena contra la Epilepsia (LICHE), Sociedad de Epileptología de Chile (SOCEPCHI) y Sociedad de Psiquiatría y Neurología de la Infancia y Adolescencia (SOPNIA) de Chile, a 6-member working committee called for a meeting of 42 Chilean pediatric epileptologists from all over the country, with the aim of reaching a consensus on the use of antiepileptic drugs in 16 selected children and adolescents electro-clinical syndromes and epilepsies. These treatment proposals were analyzed and fully discussed by the working committee, ending in an antiepileptic drug treatment recommendation guideline for each condition. This consensus is a practical guideline to be used in specific clinical situations, which aims to support treatment decision making. Its main purpose is to offer the best evidence based treatments to our children and adolescents patients with epilepsy, thus contributing to diminish variability in therapeutic decisions.

Risk of hyperamylasemia and acute pancreatitis after double-balloon enteroscopy: a prospective study.

BACKGROUND AND STUDY AIMS: There have been reports, mainly retrospective, of pancreatitis and hyperamylasemia after anterograde double-balloon enteroscopy (DBE). Our aim was to report the incidence of pancreatitis and hyperamylasemia after DBE and investigate possible risk factors associated with its occurrence. PATIENTS AND METHODS: In this single-center prospective cohort study, serum samples were taken for amylase and lipase before and 3 hours after anterograde DBE in consecutive patients. Multiple variables were recorded, including total procedure time, insertion depth, and number of passes. Patients were evaluated to 24 hours later for signs of pancreatitis. The main outcome measures were the occurrence of hyperamylasemia and pancreatitis. RESULTS: 92 patients were included in the analysis (58 women, 34 men; mean age 54 years, range 18-89). The mean total procedure time was 62 minutes (range 30-120). The mean post-procedure amylase and lipase levels were significantly higher in comparison with the baseline levels (165 U/L vs. 69 U/L and 144 U/L vs. 28 U/L respectively, P<.05); 36 patients (39%) showed hyperamylasemia after the procedure and three patients developed acute mild pancreatitis. Hyperamylasemia was associated more frequently with procedure duration greater than 60 minutes ( P<.001) and insertion depth greater than 25 cm ( P<.013). CONCLUSIONS: The incidence of hyperamylasemia after anterograde DBE is common and particularly associated with longer procedure time and insertion depth. The cumulative incidence of pancreatitis was 3%. We recommend the avoidance of both unnecessarily lengthy procedures and deep insertion distances in patients who undergo anterograde DBE.

[Hyperhomocysteinemia as risk factor in a Mexican population]. / La hiperhomocisteinemia como factor de riesgo en una población mexicana.

Hyperhomocysteinemia is considered one of the emerging risk factors for the development of coronary artery disease (CAD). In order to know the prevalence of this metabolic disorder in a Mexican population with early CAD (< 50 years), we studied a group of these patients and compared the levels of homocysteine with a group of patients, paired by age and gender, without angiographic evidence of coronary atherosclerosis. Preliminary results show that the population with early CAD has more traditional risk factors, specially diabetes mellitus, and higher levels of homocysteine in plasma. Moreover there is a genetic factor with higher incidence of a TT homozygotic mutation of the MTHFR that increases homocysteine because of an altered folate metabolism.

Helicobacter pylori and other enteric bacteria in freshwater environments in Mexico City.

BACKGROUND: Helicobacter pylori infection is common in the Mexican population; however, sources, routes, and risk factors for infection as well as mode of transmission remain unclear. METHODS: H. pylori was detected by polymerase chain reaction (PCR) technique in three aquatic systems located in the Mexico City area. In addition, microbiologic cultures and physicochemical parameters were measured. The systems were sampled over an 18-month period (1997-1999), resulting in a total of 212 samples for the different analyses. RESULTS: Twenty-one percent of the samples (16/77) were positive for H. pylori; of these, 42% (5/12) were confirmed for cagA gene detection by PCR hybridization. Microbiologic samples (n = 74) yielded Aeromonas hydrophila, Aeromonas caviae, Aeromonas veronii, and Vibrio fluvialis. In the samples for physicochemical analyses (n = 61), low concentrations of dissolved oxygen were detected and residual chlorine was less than the inactivation dose, both providing conditions for potential survival of H. pylori and other enteric pathogens in these environments. CONCLUSIONS: The results of this study suggest that, in Mexico City, water used for human consumption and irrigation may play an important role as a vehicle in the transmission of H. pylori as well as infection by other known enteric pathogens.

Epidemiology of nosocomial outbreaks: 14-year experience at a tertiary-care center.

Twelve nosocomial outbreaks over 14 years at a tertiary-care center in Mexico are described. Overall mortality was 25.8%, one half due to pneumonia. The most common organism was Pseudomonas aeruginosa. Incidence was three outbreaks per 10,000 discharges; outbreak-related infections comprised 1.56% of all nosocomial infections. Incidence in the intensive care unit was 10-fold higher.

Bloodborne viral infections in patients attending an emergency room in Mexico City: estimate of seroconversion probability in healthcare workers after an occupational exposure.

The frequency of hepatitis C (HCV), hepatitis B (HBV), human immunodeficiency virus (HIV), and human T-cell lymphotropic virus (HTLV) I/II was determined in the emergency room of a teaching hospital. Of 909 patients, 19% had at least one infection; 7.8% had HCV, 6.9% HBV, 3.3% HIV, and 2.8% HTLV I/II. The probability that a healthcare worker would have an accident with an infected patient and seroconvert was 4.99 to 24.9 per 100,000 venipunctures for HBV, 5.6 to 8.4 for HCV, and 0.12-0.16 for HIV in our emergency room.

[Nosocomial infections: secular trends of a control program in Mexico]. / Infecciones nosocomiales: tendencias seculares de un programa de control en México.

OBJECTIVE: To know the trend of nosocomial infections rates at a third level hospital since the beginning of the infection control program until the present and to evaluate the impact in mortality and length of hospital stay. MATERIAL AND METHODS: A study descriptive, retrospective and retrolective was done in a reference hospital providing tertiary care in Mexico City. Recorded data included rates, type of nosocomial infections and distribution of nosocomial infections from the database of Hospital Epidemiology Division between 1991 to 1996. In every patient the degree of severity disease was evaluated according to the McCabe-Jackson's scale, we also collected age and the length of stay. Statistical analysis was done with chi 2 test for tendencies of different evaluated parameters. This study was divided in three periods: before remodel (1991-1993), to remodel (1994-1995) and after remodel (1996). Compared the before remodel period against after remodel period. RESULTS: In the study period, mean nosocomial infections ratio was of 8.6 by 100 discharges, showing a decrease of 20% (p < 0.01). Hospital area with the highest infections rate was ICU (26.9 by 100 discharge), followed by general ward of hospitalization with shared rooms (9.47) and private rooms (7.5). Urinary tract infections was the most frequent (26.6%), followed by surgical wound infection (24.4%), pneumonia (12.1%) and primary bacteremia (9.5%). Rates of urinary tract infections and primary bacteremias had decreased significantly (p < 0.05 and p < 0.00001 respectively), while surgical wound infections and pneumonias increased (p < 0.005 and p < 0.00001 respectively). Associated mortality diminished in 36% (p < 0.00001). The length of stay diminished 42.8%. There was not differences in the severity of disease along this period. CONCLUSIONS: Since the establishment of the nosocomial infections surveillance and control program at the INNSZ on 1985, nosocomial infections rate (56%) and the associated mortality (36%) have diminished. These changes are consequence of the establishment of a nosocomial infections control program and the decrease of length of stay and does not seems to be related to the age or to the severity of the disease of the hospitalized patients.

Colonization of Mexican patients by multiple Helicobacter pylori strains with different vacA and cagA genotypes.

Helicobacter pylori virulence determinants have not previously been studied in detail in Latin Americans with H. pylori infections. We characterized the vacA (vacuolating cytotoxin gene A) and cagA (cytotoxin-associated gene A) types of more than 400 single-colony isolates from 20 patients in Mexico City. For 17 patients H. pylori strains of two or more different vacA genotypes were isolated from gastric biopsy specimens, indicating infection with two or more strains of H. pylori. The most frequent vacA genotype was s1b/m1. vacA diversity was more marked than that described previously, in that isolates from seven patients had untypeable vacA midregions and isolates from nine patients had type s1 signal sequence coding regions which could not be further subtyped. Previously undescribed vacA type s2/m1 strains were found in five patients. All patients were infected with cagA-positive strains, but occasionally, these coexisted with small numbers of cagA-negative strains. In conclusion, coinfection with multiple H. pylori strains is common in Mexico, and vacA in these strains is genetically more diverse than has been described in other populations.

An epidemic outbreak of Malassezia folliculitis in three adult patients in an intensive care unit: a previously unrecognized nosocomial infection.

BACKGROUND: Malassezia is a lipophilic fungus commonly found in normal human skin. Infection of the hair follicle by Malassezia furfur occurs in patients with predisposing factors such as diabetes or immunosuppression, or who are undergoing antibiotic treatment. Malassezia furfur folliculitis is an infrequent nosocomial infection which may be associated with fomite transmission. METHODS: We reviewed the clinical files of three adult patients from an intensive care unit (ICU) who simultaneously developed folliculitis through Malassezia infection. We specifically analysed predisposing factors, possible transmission modes, characteristics of skin lesions, results of biopsies and cultures, treatment, and patient outcome. RESULTS: The three male patients were in neighboring beds and they all had factors that predisposed them to underlying immunosupression. Simultaneously, and within hours of each other, they developed erythematous follicular papules and pustules on the face and chest. The skin biopsies revealed an acute folliculitis with abundant round to oval yeasts of up to 5 microm in diameter. Stains for fungi (Schiff's peryodic acid, Grocott and silver methenamine) revealed numerous unipolar budding yeasts without hyphae, consistent with M. furfur. Conventional cultures were negative. The diagnosis of folliculitis by M. furfur was established and antifinigal treatment initiated, with adequate outcome of the dermatosis. After this outbreak, the aseptic and hygienic measures of the health care personnel of the ICU were reviewed and corrected. CONCLUSIONS: The simultaneous emergence of this superficial infection by M. furfur suggests fomite participation. This dermatomycosis is an infrequent nosocomial infection in adults, which to our knowledge has not been previously reported.

Bronchoaspiration as a possible cause in a case of tetanus. A reminder on the importance of adulthood immunizations.

Although preventable by immunization tetanus still takes a large death toll, mostly in developing countries, where adult population is often unprotected and opportune medical care unavailable. We present a case of tetanus in an elderly patient with bronchoaspiration pneumonia after a near-drowning incident, in which no objective entry site could be suspected with as much temporal relation as the bronchoaspiration incident. Bronchoaspiration of organic matter and feces provides both a source of the causative agent and an adequate polymicrobial environment for the development of the disease. It is under such conditions that we propose this unusual entry site as the cause of tetanus in our patient. Special emphasis is made on the importance of adulthood immunization programs and how incidents like this one should be taken into account in the overall care provided to the elderly population.

Impaired metoclopramide-induced pituitary prolactin release in men with human immunodeficiency virus infection.

To investigate whether metoclopramide-induced prolactin release is impaired in HIV-infected men, we studied 10 clinically healthy HIV-negative adult men (group 1) and 10 consecutive HIV-positive adult men (group 2) with anti-HIV antibodies confirmed by Western blot analysis and a CD4 cell count from 13 to 570x10(6)/L. After a 10- to 12-hour overnight fast, three basal blood samples were obtained at 15-minute intervals (-30, -15, and 0 minutes) and thereafter at 15, 30, 60, 90, 120, 180, and 240 minutes after a 10-mg intravenous bolus of metoclopramide. Duplicate serum prolactin concentrations were measured in each sample with commercially available radioimmunoassay kits. No significant differences between groups were observed in basal prolactin levels. Group 2 had lower serum prolactin concentrations than group 1 throughout the test (P< or =.002). The area under the prolactin curve (mean +/- SD) was also lower in group 2 than in group 1 (7156+/-1433 ng/mL/240 min vs. 12430+/-2454 ng/mL/240 min, P<.0001), and the area under the prolactin curve had a significant correlation with the CD4 cell counts (r = 0.7912, P<.001). These findings suggest that the hypothalamic dopaminergic tone, although present, was clearly diminished in these HIV-positive men regardless of their clinical stage.

Thalidomide as therapy for human immunodeficiency virus-related oral ulcers: a double-blind placebo-controlled clinical trial.

A double-blind, randomized, placebo-controlled clinical trial was performed in Mexico City to evaluate the efficacy of thalidomide in treating oral recurrent aphthae in human immunodeficiency virus (HIV)-infected subjects. Sixteen HIV-infected patients with clinical and histological diagnosis of oral recurrent aphthous ulcerations received randomly an 8-week course of either thalidomide or placebo, with an initial oral dosage of 400 mg/d for 1 week, followed by 200 mg/d for 7 weeks. Ten subjects received thalidomide and six received placebo. At 8 weeks, nine subjects (90%) in the thalidomide group had complete healing of their ulcers, compared with two (33.3%) of the six patients in the placebo group (P = .03). There was a significant reduction in largest ulcer diameter in the thalidomide group. Rash was observed in 80% of the thalidomide patients. Although thalidomide demonstrated an unquestionable benefit in treatment of oral ulcers in HIV patients, caution must be taken given the frequent occurrence of side effects.

Tuberculosis-associated fatal hemophagocytic syndrome in a patient with lymphoma treated with fludarabine.

A patient with a stage IV high-grade non-Hodgkin's lymphoma who developed a fatal hemophagocytic syndrome is presented: When the patient had achieved complete remission and receiving fludarabine and chlorambucil/prednisone, she developed miliary tuberculosis, the CD4+ T-cell count then being 50/microL; the hemophagocytic syndrome ensuing at this point was fatal. Speculations about the predisposing factors that could have led to this complication are discussed focusing on the severe cellular immunosuppression which developed probably related to the use of fludafabine: it could be useful in the future to use anti-tuberculous prophylaxis in selected patients treated with this purine nucleoside analog.

Oral manifestations of HIV infection by gender and transmission category in Mexico City.

A cross-sectional analysis was conducted in Mexico City from September 1989 to March 1996, to determine the prevalence of HIV-related oral manifestations by gender and route of HIV transmission. The diagnosis of HIV-associated oral lesions was based on preestablished criteria. For the statistical analysis chi-squared and Fisher's exact tests were used where appropriate. Odds ratios were calculated as estimates of the relative risks. Control of confounding factors was performed by logistic regression models. Oral lesions were present in 75% of 436 HIV+ patients. Hairy leukoplakia, erythematous and pseudomembranous candidosis, angular cheilitis and oral ulcers were frequently found. Patients who contracted HIV through blood transfusion were more likely to present erythematous candidosis (P=0.005) than subjects who acquired HIV through sexual transmission. Oral ulcers were seen only in men (P=0.02) and in individuals who contracted HIV through sexual transmission (P=0.02). This study brings valuable data in regard to differences in the type and prevalence of HIV-related oral lesions by gender and the risk categories analysed, particularly blood transfusion.

PIP: A cross-sectional analysis conducted in Mexico City, Mexico, in 1989-96 investigated the prevalence of HIV-related oral manifestations by gender and route of HIV transmission. The 436 HIV-positive patients enrolled in this study were part of a larger, ongoing study conducted through the Infectious Diseases Clinic in Mexico City. The primary mode of HIV transmission was blood transfusion among female respondents (63%) and sexual activity among male respondents (90%). 71% of subjects had at least 1 (mean, 1.3) HIV-related oral lesion, including hairy leukoplakia, erythematous and pseudomembranous candidosis, angular cheilitis, and oral ulcers. Candidosis, pseudomembranous candidosis, hairy leukoplakia, exfoliative cheilitis, and xerostomia were all significantly associated with a CD4 count under 200 cells/cu. mm and were more prevalent among those with advanced HIV disease. Oral ulcers were present only in men. Women had a higher prevalence than men of hyperpigmentation (10.5% vs. 4%) and xerostomia (7% vs. 2%), but these differences were not significant. Multivariate analysis revealed a significant association between erythematous candidosis and blood transfusion, even after controlling for gender, clinical stage, CD4 count, antiretroviral therapy, smoking history, and xerostomia.