Digital thoracic drainage: a new system to monitor air leaks in pediatric population

Introduction

New digital thoracic drainage systems allow an objective measurement of air leakage. They have proven their usefulness in the postoperative thoracic surgery in adults, but there is little experience with its use in the pediatric population. The objective of our study is to analyze their safety and effectiveness in the postoperative period of the pediatric patients.

Black-fly assemblage distribution patterns in streams in disturbed areas in southern Brazil

Black flies (Simuliidae) are considered to be pests in rural and in some urban areas in the south of Brazil due to the bites of females. Little information exists on the factors that contribute to Simuliidae distribution in these areas. We sampled 39 streams in the state of Rio Grande do Sul in September 2004 to address ecological aspects. Of the 18 species collected, those that occurred in more than 50% of the streams were: Simulium subnigrum Lutz 1910, Simulium pertinax Kollar 1882, Simulium subpallidum Lutz 1910 and Simulium incrustatum Lutz 1910. Species richness was not influenced by any of the environmental or geographical variables considered, and there was no pattern of species co-occurrence, corroborating the hypothesis of a stochastic distribution of the Simuliidae assemblage. When analyzed individually, only three of seven species with occurrence frequency >30% were related to any of the variables measured. The probabilities of occurrence of Simulium jujuyense Paterson & Shannon 1927 and S. pertinax were higher in streams with high values of water pH and electrical conductivity, whereas the opposite was observed for S. incrustatum. Therefore, due to stochastic distribution, the population studies of Simuliidae are more suitable for predicting the occurrence of species in rural areas than are studies of assemblages.     

Evaluación del seguimiento de niños con hallazgo de hipertransaminasemia

IntroductionAlthough changes in liver function tests can be non-specific in numerous clinical conditions, they can be the first sign of a potentially serious disease in an asymptomatic patient.Material and methodsRetrospective cohort study, performed by reviewing the records of children of a reference hospital central laboratory with alanine aminorransferase enzyme (ALT) elevation during a 6 month aleatory period.Results572 blood tests with serum ALT elevation corresponding to 403 patients had been assessed during the period studied. 98 patients were excluded for presenting abnormal liver test before the study period of comorbidity that could produce ALT elevation. The remaining 305 patients, 22.6% were diagnosed with a medical condition during the first blood test that explained the ALT elevation, although only 33.3% of them were followed up until verifying their normalization. Final study sample consists of 236 patients with abnormal liver test without apparent liver disease. Adequate follow-up was found only in 29% of them. From this group, 9 patients (13%) were diagnosed with liver disease. The rest of the sample were not properly monitored. In patients with higher serum ALT levels, follow-up was early and more appropiate.ConclusionsIn our area, most children without apparent liver disease are no properly monitored. Therefore, an opportunity to diagnosis and treat a potential liver disease was lost in a great number of children. All children with unexplainedhypertransaminasaemia must be studied.     

Chronic sleep loss disrupts blood–testis and blood–epididymis barriers,and reduces male fertility

Sleep loss increases blood–brain barrier permeability. As the blood–brain barrier and the blood–tissue barriers in the reproductive tract (blood–testis and blood–epididymis barriers) share common characteristics, we hypothesized that sleep restriction may also modify their barrier function. Previous reports showed that sleep loss decreased sperm viability and progressive fast mobility, which may be a consequence of altered blood–testis and blood–epididymis barrier. Therefore, we quantified changes in blood–testis and blood–epididymis barrier after sleep loss and related them to male fertility. Adult male Wistar rats were sleep restricted using the multiple‐platform technique in a protocol of 20 hr daily sleep deprivation plus 4 hr of sleep recovery in the home‐cage. At the 10th day, barrier permeability assays were performed with Na‐fluorescein, 10 kDa Cascade blue‐dextrans and Evans blue, and the expression of tight junction proteins, actin and androgen receptor was quantified. At the 10th day of sleep restriction and after sleep recovery days 1–7, males were placed with sexually receptive females, sexual behaviour was tested, and the percentage of pregnancies was calculated. Sleep restriction increased the barrier permeability to low‐ and high‐molecular‐weight tracers, and decreased the expression of tight junction proteins, actin and androgen receptor. Concomitantly, sleep restriction reduced the percentage of ejaculating males and the number of pregnancies. Sleep recovery for 2–3 days progressively re‐established fertility, as indicated by a higher percentage of ejaculating males and impregnated females. In conclusion, chronic sleep loss alters fertility concomitantly with the disruption of the blood–tissue barriers at the reproductive tract, the mechanism involves androgen signalling.     

Melatonin modulates dysregulated circadian clocks in mice with diethylnitrosamine‐induced hepatocellular carcinoma

Disruption of circadian rhythms, which are regulated by the circadian clock machinery, plays an important role in different long‐term diseases including hepatocellular carcinoma (HCC ). Melatonin has been reported to alleviate promotion and progression of HCC , but the potential contribution of circadian clock modulation is unknown. We investigated the effects of melatonin in mice which received diethylnitrosamine (DEN ) (35 mg/kg body weight ip) once a week for 8 weeks. Melatonin was given at 5 or 10 mg kg^?1d^?1 ip beginning 4 weeks after the onset of DEN administration and ending at the sacrifice time (10, 20, 30, or 40 weeks). Liver expression of Bmal1, Clock, Npas2, Rorα, and Sirt1 increased, whereas Cry1, Per1, Per2, Per3, CK 1ε, Rev‐erbα, and Rev‐erbβ decreased following DEN administration. Melatonin treatment prevented changes in the expression of clock genes, and this effect was accompanied by an upregulation of the MT 1 receptor and reduced levels of the hypoxia‐inducible factors Hif‐1α and Hif‐2α. An increased expression of p21, p53, and PARP 1/2, a higher Bax/Bcl‐2 ratio, and a lower expression of Cyclin D1, CDK 6, HSP 70, HSP 90, and GRP 78 proteins were also observed in melatonin‐treated mice. Melatonin significantly potentiated the suppression of proliferation and cell cycle arrest induced by the synthetic REV ‐ERB agonist SR 9009 in human Hep3B cells, and BMAL 1 knocking down attenuated the pro‐apoptotic and antiproliferative effect of melatonin. Results support a contribution of changes in the circadian clock components to the beneficial effects of melatonin in HCC and highlight the usefulness of strategies modulating the circadian machinery in hepatocarcinogenesis.