To assess the anaerobic capacities of a temperate grassland soil, a Kansas prairie soil was incubated anaerobically as either soil-water (1:2) suspensions or as soil microcosms at 78% soil water-holding capacity. Prairie soil formed acetate and CO 2 as the two main initial carbonaceous products from the anaerobic turnover of endogenous organic matter. Metabolic capacities of soil suspensions and microcosms were similar. Rates of acetate formation from endogenous organic matter in soil-water suspensions incubated at 40, 30, and 15؇C approximated 3.3, 2.4, and 1.1 g of acetate per g (dry weight) of soil per h, respectively. Supplemental H 2 and CO 2 were subject to consumption with the apparent concomitant synthesis of acetate in both soil suspensions and soil microcosms. In soil microcosms, rates of H 2-dependent acetogenesis at 30 and 55؇C were nearly equivalent. The uptake of supplemental H 2 was not coupled to methanogenesis under any condition examined. These anaerobic activities were relatively stable when soils were subjected to either aerobic drying or alternating periods of O 2 enrichment. On the basis of the formation of nitrogen (N 2), denitrification was engaged during anaerobic incubation periods; nitrous oxide (N 2 O) was also formed under certain conditions. Although extended incubation of soil induced the delayed methanogenic turnover of acetate, acetate was subject to immediate turnover under either O 2-or nitrate-enriched conditions. These studies support the following concepts: (i) obligately anaerobic bacteria such as acetogenic bacteria are stable to periods of aerobiosis and are active in the anaerobic microsites of oxic soils, and (ii) acetate synthesized in anaerobic microsites of oxic terrestrial soils constitutes a trophic link to both aerobic and anaerobic microbial communities.

Everglades sediments (wetland soils) near sources of agricultural runoff had low redox potentials, were blackened with sulfide, and displayed high porewater phosphorus (total) concentrations and high water column conductivities. These sediments yielded 10 3-to 10 4-fold-higher numbers of culturable anaerobes, including methanogens, sulfate reducers, and acetate producers, than did sediments from Everglades and Lake Okeechobee comparative control sites not as directly associated with agricultural runoff. These observations demonstrated that there was a general, rather than specific, enhancement of the anaerobic microflora in the sediments most likely influenced by agricultural runoff. Despite these differences in microfloral patterns, methylmercury and total mercury levels were similar among these contrasting sediments. Although available sulfate and phosphorus appeared to stimulate the productivity of sulfate reducers in Everglades sediments, the number of culturable sulfate reducers did not directly correspond to the concentration of sulfate and phosphorus in porewaters. Microcosms supplemented with sulfate, nitrate, and phosphate altered the initial capacities of the sediment microflora to produce acetate and methane from endogenous matter. For sediments nearest sources of agricultural runoff, phosphorus temporarily enhanced acetate formation and initially suppressed methane production, sulfate enhanced acetate formation but did not significantly alter the production of methane, and nitrate totally suppressed the initial production of both methane and acetate. In regards to the latter, microbes capable of dissimilating nitrate to ammonium were present in greater culturable numbers than denitrifiers. In microcosms, acetate was a major source of methane, and supplemental hydrogen was directed towards the synthesis of acetate via CO 2-dependent acetogenesis. These findings demonstrate that Everglades sediments nearest agricultural runoff have enhanced anaerobic microbial profiles and that the anaerobic microflora are poised to respond rapidly to phosphate, sulfate, and nitrate input.

To evaluate the contemporary prevalence of diabetic peripheral neuropathy (DPN) in participants with type 1 diabetes in the T1D Exchange Clinic Registry throughout the U.S. RESEARCH DESIGN AND METHODSDPN was assessed with the Michigan Neuropathy Screening Instrument Questionnaire (MNSIQ) in adults with ‡5 years of type 1 diabetes duration. A score of ‡4 defined DPN. Associations of demographic, clinical, and laboratory factors with DPN were assessed. RESULTSAmong 5,936 T1D Exchange participants (mean 6 SD age 39 6 18 years, median type 1 diabetes duration 18 years [interquartile range 11, 31], 55% female, 88% non-Hispanic white, mean glycated hemoglobin [HbA 1c ] 8.1 6 1.6% [65.3 6 17.5 mmol/mol]), DPN prevalence was 11%. Compared with those without DPN, DPN participants were older, had higher HbA 1c , had longer duration of diabetes, were more likely to be female, and were less likely to have a college education and private insurance (all P < 0.001). DPN participants also were more likely to have cardiovascular disease (CVD) (P < 0.001), worse CVD risk factors of smoking (P 5 0.008), hypertriglyceridemia (P 5 0.002), higher BMI (P 5 0.009), retinopathy (P 5 0.004), reduced estimated glomerular filtration rate (P 5 0.02), and Charcot neuroarthropathy (P 5 0.002). There were no differences in insulin pump or continuous glucose monitor use, although DPN participants were more likely to have had severe hypoglycemia (P 5 0.04) and/or diabetic ketoacidosis (P < 0.001) in the past 3 months. CONCLUSIONSThe prevalence of DPN in this national cohort with type 1 diabetes is lower than in prior published reports but is reflective of current clinical care practices. These data also highlight that nonglycemic risk factors, such as CVD risk factors, severe hypoglycemia, diabetic ketoacidosis, and lower socioeconomic status, may also play a role in DPN development.Diabetic neuropathy is a prevalent complication in patients with diabetes and a major cause of morbidity and mortality (1). Among the various forms of diabetic neuropathy, distal symmetric polyneuropathy (DPN) and diabetic autonomic neuropathies are by far the most studied (1).

Although anaerobic microorganisms can be isolated from well‐drained soils, the qualitative and quantitative composition of the anaerobic populations potentially involved in the turnover of carbon in oxic soils is poorly resolved. In the present study, most probable number (MPN) estimates demonstrated that the number of anaerobes that were cultured from both forest (beech) mineral soil and litter approximated 107 to 108 (g dry wt. soil or litter)−1, a value that also approximated the number of acetate‐producing anaerobes. When a complex mixture of substrates was provided, the substrate‐product profiles of the MPN series indicated that the substrates that yielded the highest numbers of microbes were: yeast extract>sugars>H2>organic acids and alcohols>methoxylated aromatic compounds. Except for yeast extract, this sequence also reflected the temporal consumption of these substrates in the MPN series. The cultured anaerobic population was dominated by members of the Enterobacteriaceae and other facultative anaerobes; the facultative microorganisms appeared to determine the initial anaerobic activities of both forest soil and litter. Compared to mineral soil, litter contained more sugar‐consuming anaerobes but lower numbers of butyrate‐forming anaerobes. H2, ethanol, butanediol, and aromatic methoxyl groups were utilized by acetogenic bacteria. H2‐utilizing acetogens were a dominant group of obligate anaerobes, attesting to the ability of acetogens to survive transient or sustained periods of aeration in habitats such as leaf litter. The numbers of cultured methanogens were negligible. Together with previous findings, these results (i) demonstrate that the formation of acetate in soils is dependent on the combined activity of facultative and obligately anaerobic microorganisms, and (ii) emphasize the potential importance of acetate as an intermediate during the turnover of carbon in habitats subject to steep oxygen gradients.

IntroductionLassa fever (LF) is a severe and often fatal systemic disease in humans and affects a large number of countries in West Africa. Treatment options are limited to supportive care and the broad-spectrum antiviral agent ribavirin. However, evidence for ribavirin efficacy in patients with LF is poor and pharmacokinetic (PK) data are not available.Irrua Specialist Teaching Hospital (ISTH) developed an intravenous ribavirin regimen different to the WHO recommendation. Apart from a lower total daily dose the drug is usually administered once per day which reduces the exposure of personnel to patients with LF. The aim of this study is to characterise the PK of the Irrua ribavirin regimen.Methods and analysisThis prospective, observational clinical study will assess PK properties of the Irrua ribavirin regimen on routinely ribavirin-treated patients with LF at ISTH, a referral hospital serving 19 local governmental areas in a LF endemic zone in Nigeria. Participants will be adults with PCR-confirmed LF. The primary objective is to describe classical PK parameters for ribavirin (maximum plasma drug concentration, time to maximum plasma drug concentration, area under the plasma drug concentration vs time curve, half-life time T1/2, volume of distribution). Blood samples will be collected at 0.5, 1, 3, 5, 8, 12 and 24 hours after doses on day 1, day 4 and day 10 of ribavirin treatment. Ribavirin plasma concentrations will be determined using liquid chromatography coupled to tandem mass spectrometry.Ethics and disseminationThe study will be conducted in compliance with the protocol, the Declaration of Helsinki, Good Clinical Practice (GCP) and the Nigerian National Code for Health Research Ethics. The protocol has received approval by the Health Research Ethics Committee of ISTH. Results will be made available to LF survivors, their caregivers, the funders, LF research society and other researchers.Registration detailsISRCTN11104750