Impedance-pH Monitoring for Diagnosis of Reflux Disease: New Perspectives

Heartburn is the most specific symptom of gastroesophageal reflux disease (GERD). In clinical practice, heartburn relief by a proton pump inhibitor (PPI) trial does suffice to confirm GERD. However, an objective diagnosis of GERD is required before anti-reflux endoscopic or surgical interventions, independently from PPI response. Thus, since normal findings at upper endoscopy are detected in the majority of patients with heartburn, reflux monitoring is often required. When traditional catheter-based or wireless pH tests are used, reflux episodes are conventionally identified by pH drops below 4.0 units. Combined impedance-pH monitoring has the advantage to provide a comprehensive assessment of both physical and chemical properties of refluxate and the distinction between acid and weakly acidic refluxes, both proven to cause heartburn. Unfortunately, the conventional impedance-pH parameters, namely acid exposure time and number of reflux events, are characterized by suboptimal diagnostic sensitivity, and the reliability of symptom–reflux association indexes remains questionable. Therefore, novel impedance parameters, namely the post-reflux swallow-induced peristaltic wave (PSPW) index and the mean nocturnal baseline impedance (MNBI), have recently been proposed in order to achieve a better diagnostic yield. In fact, they proved to be highly accurate in distinguishing reflux-related from reflux-unrelated heartburn, off- as well as on-PPI therapy. Currently, manual review of impedance-pH tracings is needed because of the modest accuracy of available software tools for automated analysis. PSPW index and MNBI are highly applicable and reproducible, and their calculation requires a few additional minutes during the manual review of impedance-pH tracings. So far, we believe that PSPW index and MNBI are ready for prime time and should become part of the standard analysis of impedance-pH tracings for GERD diagnosis in patients with endoscopy-negative heartburn.     

Free-Ranging Chickens in Households in a Periurban Shantytown in Peru—Attitudes and Practices 10 Years after a Community-Based Intervention Project

Free-ranging chickens are often found in periurban communities in developing countries, and their feces can pose a significant public health sanitation problem. Corralling chickens raised in these periurban areas in chicken coops has been proposed previously as an intervention to address this problem. Aims of this study were to revisit households in a corralling intervention study conducted in 2000–2001 to compare poultry-raising practices and investigate current attitudes regarding the impact of raising chickens in a periurban environment. Sociobehavioral questionnaires were given sequentially to all study participants; 30 families (58%) ceased raising poultry of any kind, whereas 42 (81%) do not raise chickens in their home. This finding indicates a significant reduction in poultry-raising in our study population since 2000–2001, possibly because of acculturation and/or change in socioeconomic status. However, attitudes about corral use for raising poultry were overwhelmingly positive, and the most common reason cited was cleanliness of the home.     

Androgenetic alopecia and insulin resistance in young men

Background  Epidemiological studies have associated androgenetic alopecia (AGA) with severe young-age coronary artery disease and hypertension, and linked it to insulin resistance. We carried out a case–control study in age- and weight-matched young males to study the link between AGA and insulin resistance using the homeostasis model assessment of insulin resistance (HOMA-IR) index or metabolic syndrome clinical manifestations.
Methods  Eighty young males, 18–35 years old, with AGA ≥ stage III in the Hamilton–Norwood classification, and 80 weight- and age-matched controls were included. Alopecia, glucose, serum insulin, HOMA-IR index, lipid profile and androgen levels, as well as metabolic syndrome criteria, were evaluated.
Results  The HOMA-IR index was significantly higher in cases than controls. Nonobese cases had a higher mean diastolic blood pressure and a more frequent family history of AGA than nonobese controls. A borderline difference in the HOMA-IR index was found in obese AGA cases vs. obese controls [ P =  0·055, 95% confidence interval (CI) 2·36–4·20 vs. 1·75–2·73]. Free testosterone values were significantly higher in controls than cases, regardless of body mass index (BMI). A statistically significant additive effect for obesity plus alopecia was found, with significant trends for insulin, the HOMA-IR index, lipids and free testosterone when BMI and alopecia status were used to classify the participants.
Conclusions  Our results support the recommendation for assessing insulin resistance and cardiovascular-related features and disorders in all young males with stage III or higher AGA, according to the Hamilton–Norwood classification.     

Dopamine-induced migrating myoelectrical complex-like activity in human duodenum

The effect of dopamine on human gastric and small intestinal interdigestive motility was investigated in 12 subjects. Intestinal motility was recorded by means of a four-lumen polyvinyl probe with four open tips located 15 cm apart, continuously perfused with distilled water. In each subject during the same study, after recording two consecutive spontaneous phase III of migrating myoelectrical complexes and when a phase II appeared, dopamine was infused intravenously twice in a dose of 5 g/kg/min for 15 min with an interval of 20 min between each infusion. In six subjects, the second dopamine infusion was preceded by a treatment with sulpiride (10 mg, intravenously, as bolus) or domperidone (10 mg, intravenously, as bolus), each considered a highly selective dopamine antagonist. The results show that dopamine stimulates duodenal motility producing a pattern similar to that observed in phase III of spontaneously occurring migrating myoelectrical complexes. The second dopamine infusion reproduced in all cases the same pattern of motility as observed during the first infusion. Sulpiride and domperidone prevented the effect of dopamine in all cases. It is therefore suggested that dopamine-induced duodenal motility may involve specific dopaminergic receptors.     

T cell-based tracking of multidrug resistant tuberculosis infection after brief exposure

Molecular epidemiology indicates significant transmission of Mycobacterium tuberculosis after casual contact with infectious tuberculosis cases. We investigated M. tuberculosis transmission after brief exposure using a T cell-based assay, the enzyme-linked-immunospot (ELISPOT) for IFN-gamma. After childbirth, a mother was diagnosed with sputum smear-positive multidrug-resistant tuberculosis. Forty-one neonates and 47 adults were present during her admission on the maternity unit; 11 weeks later, all underwent tuberculin skin testing (TST) and ELISPOT. We correlated test results with markers of exposure to the index case. The participants, who were asymptomatic and predominantly had no prior tuberculosis exposure, had 6.05 hours mean exposure (range: 0-65 hours) to the index case. Seventeen individuals, including two newborns, were ELISPOT-positive, and ELISPOT results correlated significantly with three of four predefined measures of tuberculosis exposure. For each hour sharing room air with the index case, the odds of a positive ELISPOT result increased by 1.05 (95% CI: 1.02-1.09, p = 0.003). Only four adults were TST-positive and TST results did not correlate with exposure. Thus, ELISPOT, but not TST, suggested quite extensive nosocomial transmission of multidrug-resistant M. tuberculosis after brief exposure. These results help to explain the apparent importance of casual contact for tuberculosis transmission, and may have implications for prevention.