Arturo Reding-Bernal

Skin biopsy: a pillar in the identification of cutaneous Mycobacterium tuberculosis infection

INTRODUCTION The present study aimed to establish the frequency and clinical characteristics of cutaneous tuberculosis among Mexican adult patients. METHODOLOGY Ninety-five patients with clinically compatible lesions to cutaneous tuberculosis participated in the study. All patients were HIV negative and none of them had previous anti-TB treatment. A skin biopsy was taken from every patient suspected of having tuberculosis, and a histopathologic examination was performed as follows: Ziehl-Neelsen staining; culturing of mycobacteria by Löwenstein-Jensen (L-J) medium; Mycobacteria Growth Indicator Tube detection via BACTEC (MGIT-360); and polymerase chain reaction (PCR) with the sequence of insertion IS6110 for Mycobacterium tuberculosis complex. RESULTS Tuberculosis was confirmed in 65 out of 95 cases (68.4%). Identified lesions were scrofuloderma (42 cases, 64.6%); lupus vulgaris (12 cases, 18.4%); warty tuberculosis (six cases, 9.2%); and papulonecrotic tuberculoid (five cases; 7.7%). The Ziehl-Neelsen staining was positive for acid fast bacilli in nine cases (13.8%) and 48 patients were positive for the PCR amplification (73.8%). All skin biopsies resulted positive for tuberculosis. A positive clinical response to the specific treatment was considered a confirmation for tuberculosis. The noninfectious etiology corresponded to 30 cases (31.6%). CONCLUSIONS Tuberculosis in developing countries is still an important cause of skin lesions which must be studied via histopathological examination and culture due to their low bacillary load. A PCR test is necessary to obtain faster confirmation of the disease and to establish an early, specific and effective treatment.

Cálculo del tamaño de la muestra en investigación en educación médica

Sample size calculation in medical education research Abstract An important aspect in the research methodology, is the calculation of the number of par- ticipants that must be included in a study, since the sample size allows the researchers to

Heritability and genetic correlation between GERD symptoms severity, metabolic syndrome, and inflammation markers in families living in Mexico City

Objective The aim of this study was to estimate the heritability (h2) and genetic correlation (ρG) between GERD symptoms severity, metabolic syndrome components, and inflammation markers in Mexican families. Methods Cross-sectional study which included 32 extended families resident in Mexico City. GERD symptoms severity was assessed by the ReQuest in Practice questionnaire. Heritability and genetic correlation were determined using the Sequential Oligogenic Linkage Analysis Routines software. Results 585 subjects were included, the mean age was 42 (±16.7) years, 57% were women. The heritability of the severity of some GERD symptoms was h2 = 0.27, 0.27, 0.37, and 0.34 (p-value <1.0x10-5) for acidity complaints, lower abdominal complaints, sleep disturbances, and total ReQuest score, respectively. Heritability of metabolic syndrome components ranged from 0.40 for fasting plasma glucose to 0.61 for body mass index and diabetes mellitus. The heritability for fibrinogen and C-reactive protein was 0.64 and 0.38, respectively. Statistically significant genetic correlations were found between acidity complaints and fasting plasma glucose (ρG = 0.40); sleep disturbances and fasting plasma glucose (ρG = 0.36); acidity complaints and diabetes mellitus (ρG = 0.49) and between total ReQuest score and fasting plasma glucose (ρG = 0.43). The rest of metabolic syndrome components did not correlate with GERD symptoms. Conclusion Genetic factors substantially explain the phenotypic variance of the severity of some GERD symptoms, metabolic syndrome components and inflammation markers. Observed genetic correlations suggest that these phenotypes share common genes. These findings suggest conducting further investigation, as the determination of a linkage analysis in order to identify regions of susceptibility for developing of GERD and metabolic syndrome.

Evaluation of a comprehensive model for the treatment of hypertension, diabetes, and obesity in Mexico: a retrospective longitudinal study

Abstract Background The aim of this project was to evaluate a comprehensive model for the treatment of hypertension, diabetes, and obesity recently implemented by a new set of facilities called UNEMES-EC designed by the Ministry of Health (MoH) of Mexico nationwide as a response to the increasing prevalence of these disorders and the poor results that their traditional treatment in public institutions had generated. Methods We implemented a retrospective longitudinal study retrieving several biomarkers (glycated haemoglobin [HbA 1c ], fasting plasma glucose, systolic blood pressure [SBP], diastolic blood pressure [DBP], and body-mass index [BMI]) from the medical records of 1566 patients with 5 or more months of treatment attended in 30 randomly selected UNEMES-EC during 2012. The main outcome indicators were the proportion of patients achieving key biomarkers figures below control cutoffs in the last measurement of their medical records. Paired Students t and McNemars χ 2 tests were conducted to assess the significance of the estimates. Patient satisfaction was measured using 1200 exit interviews. Findings Mean treatment time was 11·3 months. Half of the patients with obesity experienced a reduction of at least 5% in their BMI during the treatment period. 28·4% (95% CI 24·8–31·9) of the patients with uncontrolled diabetes (HbA 1c ≥7%) at the beginning of the treatment reached control values, as well as 65·1% (61·2–69·1) of the initially uncontrolled hypertensive patients (SBP ≤140 mm Hg and DBP ≤90 mm Hg). Although the prevalence of out-of-pocket expenditure on drugs in the exit interview sample was 34·8% (95% CI 32·1–37·4), nine out of ten patients perceived better attention compared with their previous care environment. Interpretation This multidisciplinary disease-management programme had a clinically moderate but statistically significant impact on the value of several biomarkers used for the diagnosis and treatment of diabetes, hypertension, and obesity. The study did not observe a control group, but we can reasonably conclude that UNEMES-EC achieved higher control rates of diabetic and hypertensive patients than the conventional medical units of the MoH. Funding General Directorate for Performance Evaluation, Ministry of Health, Mexico.

Distal Esophageal Hypercontractility Is Related to Abnormal Acid Exposure

BACKGROUND AND AIMS Nutcracker esophagus (NE) is a frequent primary motility disorder of the distal esophagus, and the relationship with acid exposure remains controversial. We studied simultaneous distal esophageal hypercontractility (EH) using two sensors at 8 and 3 cm above the lower sphincter (LES) and abnormal exposure to acid (pH DeMeester score). METHODS From 400 screened patients with chest pain and heartburn, 54 (age 44.5 ± 8.8 years and 74% females) had abnormal manometry and underwent acid exposure measurement. Frequencies of the EH disorder were classic NE (EH(3 cm)) found in 29 (40.8%) patients, diffuse (EH(3,8 cm)) in 30 patients (42.3%), and upper segmental (EH(8 cm)) in 12 patients (16.9%). RESULTS We found a positive correlation among age with high amplitude in EH(3 cm) and EH(3,8 cm). DeMeesters score (DMS) had the lowest value for EH(3,8 cm) (2.58 ± 0.23) compared with EH(8 cm) (3.78 ± 0.3, p <0.003) and EH(3 cm) (3.12 ± 0.2, p <0.06). Surface response for joint effect of age and DMS on amplitude at EH(3 cm) confirmed the highest amplitude was for older age and lower DMS. CONCLUSIONS EH(3 cm) and EH(3,8 cm) were common for esophageal motility and were inversely associated with DMS. Meanwhile, acid exposure was higher in younger patients and hypercontractility was more frequent in older subjects. The former group may benefit more from proton pump inhibitors and the latter from visceral analgesics or possibly both.