Impact of ertapenem on antimicrobial resistance in a sentinel group of Gram-negative bacilli: a 6 year antimicrobial resistance surveillance study.

OBJECTIVES: To determine the association between ertapenem and resistance of Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii-calcoaceticus complex to different antimicrobials while adjusting for relevant hospital factors. METHODS: This was a retrospective time-series study conducted at a tertiary care centre from September 2002 to August 2008. The specific impact of ertapenem on the resistance of these Gram-negative bacilli (GNB) was assessed by multiple linear regression analysis, adjusting for the average length of stay, rate of hospital-acquired infections and use of 10 other antimicrobials, including type 2 carbapenems. RESULTS: Unadjusted analyses revealed significant increases over the duration of the study in the number of GNB resistant to meropenem/imipenem among 1000 isolates each of E. coli (0.46 ±â€Š0.22, P < 0.05), P. aeruginosa (6.26 ±â€Š2.26, P < 0.05), K. pneumoniae (8.06 ±â€Š1.50, P < 0.0005) and A. baumannii-calcoaceticus complex (25.39 ±â€Š6.81, P < 0.0005). Increased resistance to cefepime (and other extended-spectrum cephalosporins) was observed in E. coli (9.55 ±â€Š1.45, P < 0.0005) and K. pneumoniae (15.21 ±â€Š2.42, P < 0.0005). A. baumannii-calcoaceticus complex showed increased resistance to all antimicrobials except amikacin. After controlling for confounders, ertapenem was not significantly associated (P > 0.05) with changes in resistance for any pathogen/antimicrobial combination. CONCLUSIONS: After controlling for confounders, ertapenem was not associated with changes in resistance in a group of sentinel GNB, although significant variations in resistance to different antimicrobials were observed in the unadjusted analyses. These results emphasize the importance of implementation of local resistance surveillance platforms and stewardship programmes to combat the global emergence and spread of antimicrobial resistance.

Health-Related Quality of Life in leukemia Survivors of Allogeneic Hematopoietic Stem Cell Transplantation Employing the Mexican Reduced-Intensity Conditioning.

BACKGROUND: Quality of life (QOL) is an important consideration in the counseling, implementation, and post-treatment management of arduous treatments for life-threatening conditions such as allogeneic hematopoietic cell transplantation (allo-HCT). OBJECTIVE: To analyze the QOL of leukemia patients allografted with the Mexican reduced-intensity conditioning regimen in two Mexican academic medical centers. MATERIAL AND METHODS: By means of the quality metric short form 36 version 2 to measure generic health concepts, relevant QOL was analyzed in leukemia patients who underwent allo-HCT using reduced-intensity conditioning on an outpatient basis at either the Centro de Hematología y Medicina Interna de Puebla of the Clínica Ruiz or the Hematology Service of the Internal Medicine Department of the Hospital "Dr. José Eleuterio González" of the Universidad Autónoma de Nuevo León, and who had survived more than 12 months after the allograft, who could be approached, who were in a continued complete remission (with or without graft-versus-host disease), and who were willing to respond to the questionnaire. Thirty-five patients fulfilling these requirements were included, and a sex- and age-matched group of 35 reference subjects was also studied. RESULTS: Allografted patients were found to have a slightly better mental component summary than the reference subjects (53.23 vs. 48.66 points; p = 0.01), whereas the physical component summary did not show a difference (54.53 vs. 52.05 points; p = 0.59). Most of the differences between allografted individuals and reference subject controls were not significant. CONCLUSIONS: Despite several sources of bias, these data suggest that allografted individuals employing the Mexican reduced-intensity conditioning regimen enjoy a health-related QOL life similar to that of reference subjects, adding another advantage of this method of conducting stem cell allografts. However, more work needs to be done to elucidate the impact of reduced-intensity conditioning on post allo-HCT QOL.

Harnessing the post-vaccination era: Do emerging HPV types represent a new threat?

While the HPV vaccine is highly effective, it is unknown whether other, untargeted viral types could occupy empty niches to become an emerging threat. In this issue of Cell Host & Microbe, Pimenoff and colleagues present a community-level epidemiological analysis of HPV types up to 8 years after different vaccination policies.

Pathogenicity island cag, vacA and IS605 genotypes in Mexican strains of Helicobacter pylori associated with peptic ulcers.

BACKGROUND: Helicobacter pylori is associated with chronic gastritis, peptic ulcers, and gastric cancer. Two major virulence factors of H. pylori have been described: the pathogenicity island cag (cag PAI) and the vacuolating cytotoxin gene (vacA). Virtually all strains have a copy of vacA, but its genotype varies. The cag PAI is a region of 32 genes in which the insertion of IS605 elements in its middle region has been associated with partial or total deletions of it that have generated strains with varying virulence. Accordingly, the aim of this work was to determine the cag PAI integrity, vacA genotype and IS605 status in groups of isolates from Mexican patients with non-peptic ulcers (NPU), non-bleeding peptic ulcers (NBPU), and bleeding peptic ulcers (BPU). METHODS: The cag PAI integrity was performed by detection of eleven targeted genes along this locus using dot blot hybridization and PCR assays. The vacA allelic, cag PAI genotype 1 and IS605 status were determined by PCR analysis. RESULTS: Groups of 16-17 isolates (n = 50) from two patients with NPU, NBPU, and BPU, respectively, were studied. 90% (45/50) of the isolates harbored a complete cag PAI. Three BPU isolates lacked the cag PAI, and two of the NBPU had an incomplete cag PAI: the first isolate was negative for three of its genes, including deletion of the cagA gene, whereas the second did not have the cagM gene. Most of the strains (76%) had the vacA s1b/m1 genotype; meanwhile the IS605 was not present within the cag PAI of any strain but was detected elsewhere in the genome of 8% (4/50). CONCLUSION: The patients had highly virulent strains since the most of them possessed a complete cag PAI and had a vacA s1b/m1 genotype. All the isolates presented the cag PAI without any IS605 insertion (genotype 1). Combined vacA genotypes showed that 1 NPU, 2 NBPU, and 1 BPU patients (66.6%) had a mixed infection; coexistence of H. pylori strains with different cag PAI status was observed in 1 NBPU and 2 BPU (50%) of the patients, but only two of these patients (NBPU and BPU) had different vacA genotypes.

Validation of the psychometric hepatic encephalopathy score (PHES) for identifying patients with minimal hepatic encephalopathy.

BACKGROUND: The psychometric hepatic encephalopathy score (PHES) is a battery of neuropsychological tests used in the diagnosis of minimal hepatic encephalopathy (MHE). AIM: The aim of this study was to construct and validate a dataset of normal values for the PHES. METHODS: Volunteers and patients with cirrhosis with and without low-grade overt hepatic encephalopathy (OHE) were enrolled. All subjects completed the PHES battery, and possible modifying factors were assessed. Formulas to predict expected scores in cirrhotics were constructed, and MHE was diagnosed whenever a deviation of <-4 SDs occurred across the five tests. RESULTS: Among the 743 volunteers, age and years of education influenced the scores of all tests. Eighty-four patients with cirrhosis lacked evidence of OHE, whereas 20 had OHE: median PHES were -1 [0 to -3] and -9 [-6.5 to -11.8] (P < 0.001), respectively. Thirteen of the 84 patients (15%) with cirrhosis but without OHE had MHE. Patients with MHE were older and less educated than those without MHE (61 ± 8 and 52 ± 10 years old, P = 0.003; 7 ± 4 and 12 ± 5 years education, P = 0.002), whereas liver function was not different (MELD, 8 ± 5 and 8 ± 5). A very strong correlation between these norms and those derived from Spain was observed (r = 0.964, P < 0.001). CONCLUSIONS: PHES performance was mostly influenced by age and education, and expected results in cirrhotics need to be adjusted for these factors. Our validation of Mexican norms for PHES (PHES-Mex) establishes a practical method for assessing MHE and contributes to international attempts to standardize diagnostic protocols for MHE.

Prospective evaluation of oral mucositis in acute leukemia patients receiving chemotherapy.

PURPOSE: Knowledge of oral mucositis (OM) in patients with acute leukemia (AL) and chemotherapy (CT) has remained limited. Thus, a prospective, longitudinal study was undertaken to characterize clinical features, associated risk factors, and behavior of OM in a cohort of AL patients starting CT. METHODS: Prospective and longitudinal study. A cohort of patients, older than 15 years of age with AL, scheduled to receive CT, was followed from March 2006 to October 2007. At baseline and three times per week, for 21 days, patients had an oral examination performed using the Oral Mucositis Assessment Scale (OMAS); also, oral pain and difficulty to swallow were recorded using a visual analog scale. Weekly, salivary flow measurements (Schirmer's test modified version) were done. RESULTS: A cohort of 29 AL patients was followed for a median time of 21 (range, 14-53) days; 12 (41.4%) developed OM, with a mean OMAS score of 0.181 (SD +/- 0.56) and a mean peak OMAS score of 1.8 (SD +/- 0.56). The OM onset mean time was 9.8 (range, 2-20, SD +/- 6.09) days, with a mean duration of 7 (range, 3-14, SD +/- 4.15) days. OM was significantly correlated with salivary flow [rs = 0.420 (P = 0.0051)], oral pain [rs = 0.47 (P < 0.0001)], ability to swallow [rs = 0.36 (P = 0.0001)], and type of food intake [rs = 0.38 (P < 0.0001)]. CONCLUSIONS: OM is a frequent and early side effect of CT closely correlated with oral pain, difficulty to swallow, and impairment in food intake.

Diagnostic accuracy of fine needle aspiration biopsy in preoperative diagnosis of patients with parotid gland masses.

BACKGROUND: The use of fine needle aspiration biopsy (FNAB) for diagnosis of parotid gland masses (PGM) is questioned, because of low sensitivity and the generalized belief requiring surgery for most parotid masses. Information available is retrospective. Our objective was to evaluate the diagnostic accuracy of FNAB for diagnosis of patients with PGM. METHODS: A prospective diagnostic test study was conducted in a cancer center from 2003 to 2007. FNAB was obtained from patients older than 18 years with PGM. Cytopathologist and histopathologist were blinded for all clinical information. The reference standard for diagnosis was the surgical pathology report. RESULTS: FNAB sensitivity and specificity values in diagnosis of malignancy were 0.923 (95% confidence interval [CI], 0.85-0.99) and 0.986 (95% CI, 0.96-1.00), respectively. Positive and negative likelihood ratios (LRs) were 64.6 (95% CI, 9.22-453) and 0.078 (95% CI 0.03-0.18), respectively. Negative LR of FNAB was strengthened (0.078-0.029) when negative diagnosis of FNAB was associated with tumor size <4 cm, definite borders, and homogeneous tumor mass observed by computed tomography (CT). CONCLUSION: Diagnostic accuracy for FNAB was very high. No clinical or radiological factors improved the positive LR of FNAB alone. Liberal use of FNAB of PGM is recommended.

Functional implication of sequence variation in the long control region and E2 gene among human papillomavirus type 18 variants.

Cervical cancer incidence remains highly frequent in developing countries. It is possible that populations of these countries are exposed to more oncogenic human papillomavirus (HPV) variants. Functional differences among high-risk HPV variants have been described, suggesting repercussions on their oncogenic potential. In this report, we demonstrate that the long control region (LCR) of HPV18 variants has distinct transcriptional activities in different cervical cancer cell lines. African (Af)-LCR possessed the lowest transcriptional activity; its sequence harbors the highest number of nucleotide changes among the HPV18 variants analyzed. Some of these embedded in identified transcription-factor-binding sites, suggesting a less aggressive biological activity possibly involved in a slower progression of cervical lesions. Asian-Amerindian LCR showed distinct activities among cell types, while European LCR activity was similar in cell lines tested. Despite multiple nucleotide substitutions found in HPV18 E2 variant genes, their repressive activities over homologous LCRs were not distinct among variants.

Oral lesions as clinical markers of highly active antiretroviral therapy failure: a nested case-control study in Mexico City.

BACKGROUND: Clinical markers that may predict virological failure during highly active antiretroviral therapy (HAART) have not been evaluated adequately. The aim of the present study was to evaluate the usefulness of human immunodeficiency virus (HIV)-related oral lesions as clinical predictors of virological failure in HIV-infected patients receiving HAART. METHODS: A nested case-control study was conducted within a cohort of 1134 HIV-infected patients receiving HAART who attended the AIDS Clinic of the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán in Mexico City during the period 1997-2005. Case patients were patients who, after achieving an undetectable viral load, had at least 1 viral load determination > or = 2000 copies/mL while receiving treatment. Control subjects were patients who, after achieving an undetectable viral load, continued to have undetectable viral loads during the follow-up period. There were 2-3 control subjects for each case patient, matched according to duration of follow-up. Oral examinations were blinded to viral loads and CD4+ lymphocyte counts. Analyses were performed with multivariate conditional logistic regression models, and associations were shown as odds ratios (ORs) with 95% confidence intervals (CI). Positive predictive values were calculated. RESULTS: The target cohort consisted of 431 HIV-infected individuals; 47 case patients and 132 control subjects underwent complete oral examinations and formed the basis of the analysis. At the visit at which an undetectable viral load was determined, case patients and control subjects showed a similar frequency of HIV-related oral lesions (21.3% vs. 17.4%) (OR, 1.39; 95% CI, 0.57-3.38; P=.47). At the visit at which virological failure was determined, case patients showed a higher risk for HIV-related oral lesions (OR, 14.5; 95% CI, 4.21-49.94; P<.001) and oral candidosis (OR, 26.2; 95% CI, 3.34-205.9; P<.001) than did control subjects. The positive predictive value of HIV-related oral lesions and oral candidosis to identify patients who experienced virological failure while receiving HAART was 80% and 83%, respectively. CONCLUSIONS: HIV-related oral lesions and, specifically, oral candidosis may be considered to be clinical markers of virological failure in HIV-infected patients receiving HAART.

Potential toxic effects associated to metals and endotoxin present in PM10: an ancillary study using multivariate analysis.

In the evaluation of particulate matter (PM) toxicity, one faces the challenge of identifying components that could be addressed as markers of toxicity. This study examines the use of statistical methods to determine which components present in the complex mixtures are related to toxic effects. The work is based on data previously published, where we demonstrated that particles collected in different zones of Mexico City showed different ability of inducing cell death, causing DNA damage, or creating proinflammatory effects. Empirically, we correlated those differences to variations in the concentration of transitional metals or endotoxin. In order to test those correlations, in this study we evaluated the role of the concentration of six transitional metals (Ni, V, Zn, Cu, Fe, and Pb) and endotoxin using the following tools: Pearson's regression analysis, correlation matrix between components, and multiple regression followed by a stepwise analysis. Due to collinearity found among several of the components, only Ni, Zn, and Pb were considered as independent variables. Among these, Ni and Zn show better correlations and help to explain the loss in viability, whereas Pb is the component that betters explains the proinflammatory effects. The statistical identification of composition markers facilitates the generation of a hypothesis relating the role played by the composition of PM and its biological effects.

Acute Cholangitis After Bilioenteric Anastomosis for Bile Duct Injuries.

BACKGROUND/PURPOSE: The study aims to describe the clinical features, microbiology, and associated factors of acute cholangitis (AC) after bilioenteric anastomosis (BEA) for biliary duct injury (BDI). Additionally, we assessed the performance of the Tokyo Guidelines 2013 (TG13) recommendations in these patients. METHODS: We conducted a case-control study of 524 adults with a history of BEA for BDI from January 2000 to January 2014. A propensity score adjustment was performed for the analysis of the independent role of the main factors identified during the univariate logistic regression procedure. RESULTS: We identified 117 episodes of AC in 70 patients; 51.3% were definitive AC according to the TG13 diagnostic criteria, and 39.3% did not fulfill the imaging criteria of AC. A history of post-operative biliary complications (OR 2.55, 95% CI 1.38-4.70) and the bile duct confluence preservation (OR 0.46, 95% CI 0.24-0.87) were associated with AC. Eighty-nine percent of the microorganisms were Enterobacteriaceae; of them, 28% were extended spectrum ß-lactamase (ESBL) producers. CONCLUSIONS: AC is a common complication after BEA and must be suspected even in the absence of imaging findings, particulary in patients with a history of post-operative biliary complications, and/or without bile duct confluence preserved. An empirical treatment for ESBL-producing Enterobacteriaceae may be appropriate in patients living in countries with a high rate of bacterial drug resistance.

Synchronous kinetics of CD4+ lymphocytes and viral load before the onset of oral candidosis and hairy leukoplakia in a cohort of Mexican HIV-infected patients.

An observational, prospective, longitudinal cohort study was performed at the AIDS Clinic of a tertiary care institution in Mexico City to determine the association of viral load (VL) and CD4+ lymphocyte kinetics with the development of oral candidosis (OC) and hairy leukoplakia (HL). Participants were HIV-infected adult subjects, without a history of or current OC or HL, not receiving HAART. Oral examinations were performed at baseline and every month for evidence of OC or HL; CD4+ and VL determinations were done at baseline, at 6-month intervals, when oral lesions were detected, and 2 months later. Affected subjects (OL group) by OC or HL had clinical intervals defined before (antecedent), during (concurrent), and after their development. In the nonaffected individuals (NA group), 6-month intervals were determined. Differences (changes) along the clinical and study intervals were calculated for CD4+ and VL. The median study time was 178 (range: 31-924) days; 99 patients were included. The 2-year cumulative incidence of either oral lesion was 54% (49.5% for OC and 33.2% for HL). In the OL group (31 patients) a progressive and continuous decrease of CD4+ was found in the antecedent interval followed by a significant increase in VL in the concurrent period. The NA group showed a significant fall in CD4+ by semester 3, without a significant rise of VL in the following semester. The effect of CD4+ remained significant in a multivariate analysis. This study has shown that the onset of OC and/or HL is heralded by the sequence of a sustained reduction of CD4+, followed by a sharp increase of VL. In the multivariate analysis, the decrease in CD4+ lymphocytes appeared to be the predominant factor predicting the appearance of these oral lesions. Their potential use as markers of a recent change in the immunologic and virologic status of HIV-infected individuals is emphasized.

The Changing Clinical Spectrum of Human Immunodeficiency Virus (HIV)-Related Oral Lesions in 1,000 Consecutive Patients: A 12-Year Study in a Referral Center in Mexico.

In developing countries, the variations in the clinical spectrum of human immunodeficiency virus (HIV)-related oral lesions over time, and the possible effects of antiretroviral therapy, have not been described. In this study we evaluate the clinical spectrum of oral lesions in a series of HIV-infected patients when first examined at the acquired immunodeficiency syndrome (AIDS) clinic of a tertiary care institution in Mexico City, Mexico, and the changes observed over 12 years. All HIV-infected adult patients had an oral examination performed by specialists in oral pathology and medicine who used established clinical diagnostic criteria for oral lesions. Four periods were defined according to the evolving pattern of antiretroviral use: the first 2 were before the introduction of highly active antiretroviral therapy (HAART) and the last 2 were during more established use of HAART. For the statistical analysis the chi-square test for contingency tables and the chi-square test for trend were utilized. For dimensional variables, except age, the Kruskal-Wallis or Mann-Whitney rank sum tests were used when applicable and trend was tested with the Spearman correlation coefficient. Age was tested through analysis of variance (ANOVA) and linear regression analysis. Alpha value was set at p = 0.05 for each test. In the 12-year study, 1,000 HIV-infected patients were included (87.9% male). At the baseline examination, oral lesions strongly associated with HIV were present in 47.1% of HIV-infected patients. Oral candidosis (31.6%), hairy leukoplakia (22.6%), erythematous candidosis (21.0%), and pseudomembranous candidosis (15.8%) were the most frequent lesions. Oral Kaposi sarcoma (2.3%), HIV-associated periodontal disease (1.7%), and oral non-Hodgkin lymphoma (0.1%) were less frequent. HIV-related oral lesions decreased systematically-by half during the course of the 4 study periods (p < 0.001). Except for Kaposi sarcoma, all oral lesions strongly associated with HIV showed a trend to decrease significantly during the study period. No apparent variation in the occurrence of salivary gland disease or human papillomavirus-associated oral lesions was found. A significant trend to a lower prevalence was observed in the group of patients who were already taking antiretroviral therapy, non-HAART and HAART (p < 0.001 and p = 0.004, respectively). Only a discrete reduction, barely significant, was noted among untreated patients (p = 0.060). By Period IV (1999-2001), those who received HAART showed the lowest prevalence of oral lesions strongly associated with HIV (p < 0.001). Patients with oral lesions strongly associated with HIV had significantly lower median CD4+ counts and higher viral loads than those without oral lesions strongly associated with HIV (p < 0.001 and p = 0.005, respectively). When CD4+ counts were correlated with prevalence of oral candidosis, a consistently negative association was found; this association prevailed even after the study group was partitioned according to period. In this selected cohort of 1,000 patients with HIV infection, the clinical spectrum of HIV-related oral lesions has changed over the 12-year study, with a decreased prevalence of most oral lesions. Our findings probably represent improvements in medical care of HIV-infected persons, earlier detection of HIV-infected patients at the AIDS clinic, the increasing use of prophylactic drugs to prevent secondary AIDS-related opportunistic infections, and, perhaps most important, the availability of potent antiretroviral therapy in recent years, since the introduction of HAART.

Insulin subcutaneous application vs. continuous infusion for postoperative blood glucose control in patients with non-insulin-dependent diabetes mellitus.

BACKGROUND: Frequently, the use of insulin is considered for metabolic control in postoperative patients with non-insulin-dependent diabetes mellitus (NIDDM). We sought to determine the best method for control of glucose in NIDDM non-insulin patients during postoperative care. METHODS: Two algorithms were developed: subcutaneous administration of insulin (SC), and continuous intravenous infusion (IV). A randomized, controlled clinical trial was designed. In addition, both experimental groups were compared with a non-concurrent routinely managed group (RM) with insulin administration under no predetermined algorithm. Eligible patients were those subjected to major surgery under general anesthesia or spinal blockade. They were followed for 48 h after surgery. Target variables were capillary and central blood glucose, insulin dose administered, urine glucose and ketone strip determination, and development of hyper- or hypoglycemia. RESULTS: A total of 62 patients were studied (RM = 25, SC = 19, IV = 18). Results for both experimental algorithms were similar except for the IV group that required less insulin per hour compared to SC (0.64 vs. 0.34 U/h; p = 0.0003). The RM control group showed poor control in all capillary glucose measurements (194.9 +/- 26.8 mg/dL) compared with the two experimental algorithms (SC = 129.9 +/- 21; IV = 131.6 +/- 20.4) (p <0.05). More hyperglycemia events appeared in the RM group (p = 0.016). Only one hypoglycemia event occurred in the IV group. CONCLUSIONS: Postoperative control of NIDDM is similar with both tested methods. The use of any of the algorithms studied improves metabolic control substantially because it standardizes postoperative management of the diabetic patient with timely determination of capillary blood glucose and insulin administration. However, IV administration has the advantage of accomplishing adequate control with a smaller insulin dose.

A comparison of three rating scales for measuring subjective phenomena in clinical research. II. Use of experimentally controlled visual stimuli.

BACKGROUND: In a previous study of three types of global scales we found that verbal rating scales were particularly reliable for rating auditory stimuli. We now wanted to check the performance of the scales for rating experimentally controlled visual stimuli. METHODS: We used a prospective, experimentally controlled, clinimetric study, which was conducted at the Department of Psychiatry of the Autonomous University of Puebla Medical School in the state capital city of Puebla, Mexico. A total of 20 fifth-year medical students participated in the study. Visual stimuli consisted of 15 cards with five different intensities on the gray-to-black scale, administered randomly in three sessions to each subject. With regard to main outcome measurement, validity and consistency indices were determined for visual analog scale (VAS), numerical rating score (NRS), and verbal rating scale (VRS) to rate visual stimuli. RESULTS: For validity, correlation coefficients between scales and reference standard were high, especially in VRS (r=0.902). For consistency, VRS had highest kappa value (k(w)=0.71) for interobserver variability. CONCLUSIONS: Three instruments could be hierarchically ranked for their indices of validity and consistency. Being more consistent than VAS and NRS, VRS merits more frequent usage in clinical research.

Bleeding peptic ulcers and presence of Helicobacter pylori by various tests: a case-control study.

BACKGROUND: Virulence factors of Helicobacter pylori are associated with peptic ulcer disease and may be also associated with bleeding peptic ulcers (BPU). AIM: To determine whether H. pylori and/or the cytotoxin-associated gene (cagA) can increase the risk of bleeding in peptic ulcers. PATIENTS: Sixty-seven patients were studied. Thirty had BPU, 20 had non-bleeding peptic ulcers (NBPU), and 17 were control subjects (NPU). METHODS: The prevalence of H. pylori was assessed by the urease fast test, histological examination, serology, and 16S ribosomal RNA and cagA gene amplification by polymerase chain reaction (PCR). RESULTS: Histology and PCR showed greater sensitivity for diagnosis of H. pylori under bleeding circumstances when compared with other tests. Association of H. pylori was greater in the NBPU group (odds ratio [OR] 4.91, P = 0.06) than in the BPU group (OR 1.27, P = NS) when compared with the control group. When the BPU and NBPU groups were compared, H. pylori was found more often in the NBPU group (OR 0.26, P < 0.10 ). The cagA-positive gene showed a similar distribution in the three groups. The titres for anti-CagA immunoglobulin A (IgA) antibodies were higher in NBPU patients (83%) than in BPU or control patients. Furthermore, anti-urease immunoglobulin G (IgG) was detected more frequently among BPU and NBPU patients. CONCLUSIONS: NBPU patients had the highest prevalence of H. pylori by PCR. It seems unlikely that either H. pylori or the cagA-positive gene act as significant risk factors for bleeding in peptic ulcers. The lower prevalence of the microorganism among patients who bleed cannot be explained as an artificial finding.

Adenocarcinoma of the stomach: univariate and multivariate analysis of factors associated with survival.

Gastric cancer is the most frequent tumor of the digestive tract in Mexico. Most patients are diagnosed at advanced stages, and fatal outcome is expected. One hundred fifty patient charts were retrospectively reviewed. Univariate and multivariate analyses were performed to evaluate the impact of clinicopathologic and treatment variables on survival. Most patients (75%) were at advanced stages, harboring poorly differentiated tumors. Surgery, mostly palliative, was performed on 114 patients. Chemotherapy was administered to 47 patients. On univariate analysis, significant prognostic factors were TNM stage, chemotherapy, surgical attempt, performance status, histology, and tumor site (p < 0.001). On multivariate analysis, independent prognostic factors were TNM stage, histology, tumor site, surgical attempt, and chemotherapy (p < 0.01). Median survival for patients with palliative or adjuvant chemotherapy was 11.4 and 10.4 months, respectively, compared with +/- 3 months for patients with no chemotherapy (p < 0.03). Nonsurgical patients receiving chemotherapy survived 5.4 months versus 1.1 months for those without chemotherapy. The favorable influence of chemotherapy persisted after a stratified analysis of subgroups eliminating potential biases. We identified prognostic factors for survival. Chemotherapy should be considered even for advanced-stage patients with either adjuvant or palliative attempts, because we consistently found a favorable impact on the median survival time. However, phase III prospective randomized trials are awaited.

Bacteria and disinfection byproducts in water from southern Mexico City.

Disinfection byproducts and microorganisms present in drinking water may have deleterious effects on human health. The authors examined bacterial indicators (enterobacteria and Helicobacter pylori [H. pylori]), physicochemical parameters, and trihalomethane (THM) levels to conduct a water quality evaluation in Mexico City, where little is known about disinfection byproducts and microbial counts. Analyses were performed by standard membrane filtration for the enumeration of total coliforms, fecal coliforms, fecal streptococci, and Vibrio species. Other testing consisted of polymerase chain reaction (PCR) for H. pylori, physicochemical parameters by selective electrodes, and THMs by head-space with the use of a gas chromatograph. Indicator bacteria and enterobacteria were detected in 23% of samples, with significant differences between total coliforms, fecal coliforms, and fecal streptococci before and after chlorination. H. pylori was detected in 69% of samples prior to chlorination and 57% postchlorination. THM levels were < 200 microg/l. Chlorine concentrations ranged from < 0.05 mg/l to 35 mg/l. Disinfection at the well does not ensure good water quality for the Mexico City population. The next step will be the monitoring of water quality in the distribution system that supplies dwellings, as well as water obtained directly from the tap.

[Recognition of international ethics codes by physicians and biomedical investigators. Are we prepared for the 21st century challenges?]. / Reconocimiento de declaraciones éticas internacionales por médicos e investigadores en salud. Estamos preparados para los retos del siglo XXI?

International oaths and declarations (IOD) represent the essence of proposals or promises on a relevant global issue for which a social group stands for. Their appropriate spread is essential in order for them to have a significant impact. The purpose of this study was to determine the frequency of recognition of several medical practice and clinical research related IOD, among medical personnel differentiated by level of clinical experience and closeness to biomedical research. Five groups were surveyed: 35 undergraduate interns, 50 internal medicine residents, 19 graduate (masters and doctoral degrees) students at the outset of courses, 18 veteran graduate students and 70 biomedical investigators. Performance in the recognition of the 6 probed IOD was uniformly poor. Barely just an average of about one declaration per subject was adequately identified. The Declaration of Helsinki was recognized by more than 50% of those belonging to the groups in which theory and practice of medical research joined together. No other IOD was recognized beyond a 40% level in any group. Comparison of university of origin showed no substantial differences. The lack of knowledge of IOD as a framework in the analysis of ethical conflicts arising along medical practice or clinical research is a worrisome issue. Medical schools seem to neglect their role in divulging them. Institutional review boards should also contribute to divulge IOD. The optimal incorporation of the IOD message comes from its acquisition through a process that links theory and practice.