The transport of aquatic animals by birds. [Translation from: Binnengewaesser 18, 156-159, 1950.]

A great deal has been written on the part which birds play in the dispersal of freshwater fauna. This article summarises literature on the dispersal of aquatic animals by birds and aquatic insects

Gender disparities in pulmonary hypertension at a tertiary centre in Cameroon

Background. Pulmonary hypertension (PH) is a potent cause of heart failure and has been little investigated in the African setting. Objective. To investigate the effects of gender on the clinical presentation, echocardiographic features and outcomes of patients with PH in Douala, Cameroon. Methods. A prospective cohort study was conducted from March 2012 to December 2013 as part of the Pan African Pulmonary Hypertension Cohort study. PH was diagnosed by echocardiography and defined as a right ventricular systolic pressure >35 mmHg in the absence of acute right heart failure. Patients were followed up for a maximum of 12 months for primary endpoint mortality. Results. In total, 130 patients with PH were recruited; 71 (54.6%) were women. The median age was 59.2 years for men and 58.3 years for women (p=0.76). Active smoking and alcohol use were more frequent in men than women (both p<0.001), but women had greater exposure to indoor cooking fumes than men (p<0.001). Previous tuberculosis infection (11.3% v. 1.7%) and S3 gallop rhythm (30.9% v. 11.9%) were more common in women (both p<0.03). Women had a significantly higher mean systolic blood pressure (134 mmHg v. 125 mmHg; p=0.04) and pulse pressure (53.8 mmHg v. 44.9 mmHg; p=0.01) and a lower mean haemoglobin concentration (10.4 g/dL v. 12.4 g/dL; p<0.05) compared with men. Echocardiographic left ventricular (LV) systolic dysfunction was more frequent in men: mean LV ejection fraction 42.6% v. 51.5% (p=0.01) and mean fractional shortening 21.4% v. 28.6% (p=0.01). The overall mortality rate was 20.3%, and rates were similar in the two groups (Kaplan-Meier log rank 1.1; p=0.30). Conclusions. Despite differences in baseline characteristics including cardiovascular risk factors, mortality rates on follow-up were similar in men and women in this study. However, these different baseline characteristics probably suggest differences in the pathogenesis of PH in men and women in our setting that need further investigation.S Afr Med J 2017;107(10):892-89

Using biomarkers to predict TB treatment duration (Predict TB): a prospective, randomized, noninferiority, treatment shortening clinical trial

Background : By the early 1980s, tuberculosis treatment was shortened from 24 to 6 months, maintaining relapse rates of 1-2%. Subsequent trials attempting shorter durations have failed, with 4-month arms consistently having relapse rates of 15-20%. One trial shortened treatment only among those without baseline cavity on chest x-ray and whose month 2 sputum culture converted to negative. The 4-month arm relapse rate decreased to 7% but was still significantly worse than the 6-month arm (1.6%, P<0.01).  We hypothesize that PET/CT characteristics at baseline, PET/CT changes at one month, and markers of residual bacterial load will identify patients with tuberculosis who can be cured with 4 months (16 weeks) of standard treatment.Methods: This is a prospective, multicenter, randomized, phase 2b, noninferiority clinical trial of pulmonary tuberculosis participants. Those eligible start standard of care treatment. PET/CT scans are done at weeks 0, 4, and 16 or 24. Participants who do not meet early treatment completion criteria (baseline radiologic severity, radiologic response at one month, and GeneXpert-detectable bacilli at four months) are placed in Arm A (24 weeks of standard therapy). Those who meet the early treatment completion criteria are randomized at week 16 to continue treatment to week 24 (Arm B) or complete treatment at week 16 (Arm C). The primary endpoint compares the treatment success rate at 18 months between Arms B and C.Discussion: Multiple biomarkers have been assessed to predict TB treatment outcomes. This study uses PET/CT scans and GeneXpert (Xpert) cycle threshold to risk stratify participants. PET/CT scans are not applicable to global public health but could be used in clinical trials to stratify participants and possibly become a surrogate endpoint. If the Predict TB trial is successful, other immunological biomarkers or transcriptional signatures that correlate with treatment outcome may be identified. TRIAL REGISTRATION: NCT02821832

Spectrum of cardiac disease in maternity in a low-resource cohort in South Africa

Background: Lack of evidence-based data on the spectrum of cardiovascular disease (CVD) in pregnancy or in the postpartum period, as well as on maternal and fetal outcome, provides challenges for treating physicians, particularly in areas of low resources. The objectives of this study were to investigate the spectrum of disease, mode of presentation and maternal and fetal outcome of patients referred to a dedicated Cardiac Disease and Maternity Clinic (CDM). Methods: The prospective cohort study was conducted at a single tertiary care centre in South Africa. Two hundred and twenty-five women presenting with CVD in pregnancy, or within 6 months postpartum, were studied over a period of 2 years. Clinical assessment, echocardiography and laboratory tests were performed at baseline and follow-up visits. Prepartum, peripartum and postpartum complications were grouped into cardiac, neonatal and obstetric events. Results: Ethnicity was black African (45%), mixed ethnicity (32%), white (15%), Indian/others (8%) and 12% were HIV positive. Of the 225 consecutive women (mean age 28.8±6.4), 196 (86.7%) presented prepartum and 73 in modified WHO class I. The 152 women presenting in a higher risk group (modified WHO class II-IV) were offered close follow-up at the CDM clinic and were diagnosed with congenital heart disease (32%, 15 operated previously), valvular heart disease (26%, 15 operated previously), cardiomyopathy (27%) and other (15%). Women presenting with symptoms of CVD or heart failure postpartum (n=30) presented in a higher New York Heart Association, had higher heart rates (p42 days postpartum. Perinatal death occurred in 1/152 (0.7%) - translating to a perinatal mortality rate of 7/1000 live births. Conclusions: Disease patterns were markedly different to that seen in the developed world. However, joint obstetric-cardiac care in the low-resource cohort was associated with excellent survival outcome rates of pregnant mothers (even with complex diseases) and their offspring and was similar to that seen in the western world. Mortality typically occurred in the postpartum period, beyond the standard date of recording maternal death

Aquatic community response to volcanic eruptions on the Ecuadorian Andean flank: evidence from the palaeoecological record

Aquatic ecosystems in the tropical Andes are under increasing pressure from human modification of the landscape (deforestation and dams) and climatic change (increase of extreme events and 1.5 °C on average temperatures are projected for AD 2100). However, the resilience of these ecosystems to perturbations is poorly understood. Here we use a multi-proxy palaeoecological approach to assess the response of aquatic ecosystems to a major mechanism for natural disturbance, volcanic ash deposition. Specifically, we present data from two Neotropical lakes located on the eastern Andean flank of Ecuador. Laguna Pindo (1°27.132′S–78°04.847′W) is a tectonically formed closed basin surrounded by a dense mid-elevation forest, whereas Laguna Baños (0°19.328′S–78°09.175′W) is a glacially formed lake with an inflow and outflow in high Andean Páramo grasslands. In each lake we examined the dynamics of chironomids and other aquatic and semi-aquatic organisms to explore the effect of thick (> 5 cm) volcanic deposits on the aquatic communities in these two systems with different catchment features. In both lakes past volcanic ash deposition was evident from four large tephras dated to c.850 cal year BP (Pindo), and 4600, 3600 and 1500 cal year BP (Baños). Examination of the chironomid and aquatic assemblages before and after the ash depositions revealed no shift in composition at Pindo, but a major change at Baños occurred after the last event around 1500 cal year BP. Chironomids at Baños changed from an assemblage dominated by Pseudochironomus and Polypedilum nubifer-type to Cricotopus/Paratrichocladius type-II, and such a dominance lasted for approximately 380 years. We suggest that, despite potential changes in the water chemistry, the major effect on the chironomid community resulted from the thickness of the tephra being deposited, which acted to shallow the water body beyond a depth threshold. Changes in the aquatic flora and fauna at the base of the trophic chain can promote cascade effects that may deteriorate the ecosystem, especially when already influenced by human activities, such as deforestation and dams, which is frequent in the high Andes

Prednisone for the prevention of tuberculosis-associated IRIS (randomized controlled trial): Impact on the health-related quality of life

Background: Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is an important complication in patients with HIV-associated tuberculosis (TB) starting antiretroviral treatment (ART) in sub-Saharan Africa. The PredART-trial recently showed that prophylactic prednisone reduces the incidence of paradoxical TB-IRIS by 30% in a population at high risk. This paper reports the impact of the intervention on health-related quality of life (HRQoL), a secondary endpoint of the trial, measured by an amended version of the PROQOL-HIV instrument—the instrument’s validity and reliability is also assessed. Methods: A total of 240 adult participants (antiretroviral treatment (ART)-naïve, TB-HIV co-infected with CD4 count ≤100 cells/μL) were recruited and randomized (1:1) to (1) a prednisone arm or (2) a placebo arm. In this sub-study of the PredART-trial we evaluated (1) the performance of an HIV-specific HR-QoL instrument amended for TB-IRIS, i.e., the PROQOL-HIV/TB in patients with HIV-associated TB starting ART (reliability, internal and external construct validity and invariance across time) and (2) the impact of prednisone on self-reported HR-QoL in this population through mixed models. Results: The PROQOL-HIV/TB scale displayed acceptable internal reliability and good internal and external validity. This instrument, including the factor structure with the eight sub-dimensions, can thus be applied for measuring HR-QoL among HIV-TB patients at high risk for TB-IRIS. Prophylactic prednisone was statistically significantly associated only with the ‘Physical Health and Symptoms’-subscale: a four-week course of prednisone resulted in an earlier improvement in the physical dimension of HR-QoL compared to placebo. Conclusion: We demonstrated that the PROQOL-HIV/TB scale adequately measures different aspects of self-reported HR-QoL in HIV-TB patients. Although more research is needed to understand how other domains related to HR-QoL can be improved, targeting patients at high risk for developing TB-IRIS with a four-week course of prednisone has a beneficial effect on the physical aspects of patient-reported quality of life

Final analysis of a trial of M72/AS01E vaccine to prevent tuberculosis

Background Results of an earlier analysis of a trial of the M72/AS01E candidate vaccine against Mycobacterium tuberculosis showed that in infected adults, the vaccine provided 54.0% protection against active pulmonary tuberculosis disease, without evident safety concerns. We now report the results of the 3-year final analysis of efficacy, safety, and immunogenicity. Methods From August 2014 through November 2015, we enrolled adults 18 to 50 years of age with M. tuberculosis infection (defined by positive results on interferon-γ release assay) without evidence of active tuberculosis disease at centers in Kenya, South Africa, and Zambia. Participants were randomly assigned in a 1:1 ratio to receive two doses of either M72/AS01E or placebo, administered 1 month apart. The primary objective was to evaluate the efficacy of M72/AS01E to prevent active pulmonary tuberculosis disease according to the first case definition (bacteriologically confirmed pulmonary tuberculosis not associated with human immunodeficiency virus infection). Participants were followed for 3 years after the second dose. Participants with clinical suspicion of tuberculosis provided sputum samples for polymerase-chain-reaction assay, mycobacterial culture, or both. Humoral and cell-mediated immune responses were evaluated until month 36 in a subgroup of 300 participants. Safety was assessed in all participants who received at least one dose of M72/AS01E or placebo. Results A total of 3575 participants underwent randomization, of whom 3573 received at least one dose of M72/AS01E or placebo, and 3330 received both planned doses. Among the 3289 participants in the according-to-protocol efficacy cohort, 13 of the 1626 participants in the M72/AS01E group, as compared with 26 of the 1663 participants in the placebo group, had cases of tuberculosis that met the first case definition (incidence, 0.3 vs. 0.6 cases per 100 person-years). The vaccine efficacy at month 36 was 49.7% (90% confidence interval [CI], 12.1 to 71.2; 95% CI, 2.1 to 74.2). Among participants in the M72/AS01E group, the concentrations of M72-specific antibodies and the frequencies of M72-specific CD4+ T cells increased after the first dose and were sustained throughout the follow-up period. Serious adverse events, potential immune-mediated diseases, and deaths occurred with similar frequencies in the two groups. Conclusions Among adults infected with M. tuberculosis, vaccination with M72/AS01E elicited an immune response and provided protection against progression to pulmonary tuberculosis disease for at least 3 years. (Funded by GlaxoSmithKline Biologicals and Aeras; ClinicalTrials.gov number, NCT01755598. opens in new tab.

Porewater methane transport within the gas vesicles of diurnally migrating Chaoborus spp.: An energetic advantage

We show that diurnally migrating Chaoborus sp. (phantom midge larvae), which can be highly abundant in eutrophic lakes with anoxic bottom, utilises sediment methane to inflate their tracheal sacs, which provides positive buoyancy to aid vertical migration. This process also effectively transports sediment methane bypassing oxidation to the upper water column, adding to the total methane outflux to the atmosphere