Adenosine effects upon insulin action on lipolysis and glucose transport in human adipocytes

The dose response effect of a new adenosine analogue, GR 79236 (N-[1S trans-2-hydroxycyclopentyl] adenosine) upon insulin sensitivity was examined in human adipocytes. The influence of adenosine upon insulin sensitivity for suppression of lipolysis and stimulation of glucose transport was examined. Removal of adenosine by use of adenosine deaminase stimulated lipolysis to the same extent as did 10^–9 M noradrenaline. GR79236 brought about dose dependent inhibition of lipolysis with half-maximal effect at 11.3±7.8×10^–9 M. When lipolysis was stimulated by noradrenaline alone the subsequent inhibition of lipolysis brought about by GR79236 was significantly greater than that of insulin. To examine adenosine effects on the insulin signalling pathway separately from those on lipolysis, the insulin sensitivity of glucose transport was examined. Removal of adenosine brought about a small but significant increase in the concentration of insulin required for half-maximal stimulation of glucose transport. Adenosine agonists offer promise as new agents for the modulation of metabolism in diabetes and other states of insulin resistance.     

The subunit characterization of Callinectes sapidus hemocyanin.

Hemocyanin from the blue crab, Callinectes sapidus, sediments at 25.7 S and has a native molecular weight of 940 000 +/- 20 000. Under solution conditions of increased pH (approximately 10) or ionic strength, the native molecule dissociates to a 17 S species. Reversal of this dissociation was unsuccessful. At pH 10 and with the removal of Mg2+, the 17 S species reversibly dissociates to form a subunit species which sediments at 6 S. A comparison of the circular dichroic spectra of the 25.7 S and 6 S hemocyanins suggests that little happens to the structural integrity of the polypeptide backbone upon the two dissociations. Molecular weight estimations under reducing and denaturing conditions indicate that the 6 S hemocyanin species represents the constituent polypeptide chain of the protein molecule. Chemical analysis suggests the presence of a small amount, less than 3%, of carbohydrate bound to the polypeptide chain. Electrophoresis of the hemocyanin in the presence of sodium dodecyl sulfate or urea reveals two major electrophoretic species of either slightly different chemical composition or slightly different polypeptide chain length.     

Oxidation of n-alkanes: Growth of Pseudomonas putida

Summary The induction of alkane hydroxylase activity was investigated in two strains of Pseudomonas putida with a view to the production of primary alcohols. n-Nonanol production rates (16.0 mol/g dry wt/h) with an alcohol dehydrogenase negative mutant P. putida PpS173 were considerably lower than might be expected from the growth of a wild type on n-alkane. Production of cells by fed-batch culture on n-nonane, with a specific alkane hydroxylase activity of 3.9 mmol/g/h, was considered most suitable for isolation of the alkane hydroxylase.     

Parallel activities of fatty acid methyl esters and analogous phorbol diesters toward mouse lymphocytes

Linear saturated fatty acid methyl esters were comitogenic with lectins for mouse lymphocytes, the degree of comitogenicity being strongly dependent on the length of the acyl group, and maximal for methyl tetradecanoate. Lesser effects were found for analogs with 10, 12 or 16 acyl carbon atoms, whereas those with fewer than 10 or more than 16 were inactive. Analogous structure-function relationships have been described for various membrane-active and tumor-promoting phorbol diesters, where there is a similar dependence on ester acyl group length for many activities. The fatty acid esters may therefore represent simple model compounds for studying mechanistic aspects of phorbol diester activity.     

The effects of dogfish MSH''s and of corticotrophin-like intermediate lobe peptides (CLIP''s) on avoidance behavior in rats

Recently purified melanocyte-stimulating hormones (MSH's) from dogfish pituitary tissue were tested on extinction of a conditioned avoidance response (CAR). Corticotrophin like intermediate lobe peptides (CLIP's) from dogfish and porcine origin were tested for an effect on avoidance extinction as well. All peptides appeared to delay extinction of the CAR.The results suggest that the pituitary contains various peptides which influence adaptive behavior. The observation that MSH is more potent in delaying extinction of the CAR then CLIP leads to the conclusion that the behavioral active sequence of the ACTH molecules is located in the N terminal part rather than in the C terminal part of the polypetide.     

Evaluation of the Growth Assessment Protocol (GAP) for antenatal detection of small for gestational age: The DESiGN cluster randomised trial

BackgroundAntenatal detection and management of small for gestational age (SGA) is a strategy to reduce stillbirth. Large observational studies provide conflicting results on the effect of the Growth Assessment Protocol (GAP) in relation to detection of SGA and reduction of stillbirth; to the best of our knowledge, there are no reported randomised control trials. Our aim was to determine if GAP improves antenatal detection of SGA compared to standard care.Methods and findingsThis was a pragmatic, superiority, 2-arm, parallel group, open, cluster randomised control trial. Maternity units in England were eligible to participate in the study, except if they had already implemented GAP. All women who gave birth in participating clusters (maternity units) during the year prior to randomisation and during the trial (November 2016 to February 2019) were included. Multiple pregnancies, fetal abnormalities or births before 24⁺¹ weeks were excluded. Clusters were randomised to immediate implementation of GAP, an antenatal care package aimed at improving detection of SGA as a means to reduce the rate of stillbirth, or to standard care. Randomisation by random permutation was stratified by time of study inclusion and cluster size. Data were obtained from hospital electronic records for 12 months prerandomisation, the washout period (interval between randomisation and data collection of outcomes), and the outcome period (last 6 months of the study). The primary outcome was ultrasound detection of SGA (estimated fetal weight <10th centile using customised centiles (intervention) or Hadlock centiles (standard care)) confirmed at birth (birthweight <10th centile by both customised and population centiles). Secondary outcomes were maternal and neonatal outcomes, including induction of labour, gestational age at delivery, mode of birth, neonatal morbidity, and stillbirth/perinatal mortality. A 2-stage cluster–summary statistical approach calculated the absolute difference (intervention minus standard care arm) adjusted using the prerandomisation estimate, maternal age, ethnicity, parity, and randomisation strata. Intervention arm clusters that made no attempt to implement GAP were excluded in modified intention to treat (mITT) analysis; full ITT was also reported. Process evaluation assessed implementation fidelity, reach, dose, acceptability, and feasibility. Seven clusters were randomised to GAP and 6 to standard care. Following exclusions, there were 11,096 births exposed to the intervention (5 clusters) and 13,810 exposed to standard care (6 clusters) during the outcome period (mITT analysis). Age, height, and weight were broadly similar between arms, but there were fewer women: of white ethnicity (56.2% versus 62.7%), and in the least deprived quintile of the Index of Multiple Deprivation (7.5% versus 16.5%) in the intervention arm during the outcome period. Antenatal detection of SGA was 25.9% in the intervention and 27.7% in the standard care arm (adjusted difference 2.2%, 95% confidence interval (CI) −6.4% to 10.7%; p = 0.62). Findings were consistent in full ITT analysis. Fidelity and dose of GAP implementation were variable, while a high proportion (88.7%) of women were reached. Use of routinely collected data is both a strength (cost-efficient) and a limitation (occurrence of missing data); the modest number of clusters limits our ability to study small effect sizes.ConclusionsIn this study, we observed no effect of GAP on antenatal detection of SGA compared to standard care. Given variable implementation observed, future studies should incorporate standardised implementation outcomes such as those reported here to determine generalisability of our findings.Trial registrationThis trial is registered with the ISRCTN registry, ISRCTN67698474.

Matias C Vieira and colleagues evaluate the Growth Assessment Protocol (GAP) for antenatal detection of small for gestational age in the DESiGN cluster randomised trial.     

Factors Contributing to the Delay in Diagnosis and Continued Transmission of Leprosy in Brazil – An Explorative,Quantitative, Questionnaire Based Study

BackgroundLeprosy is a leading cause of preventable disability worldwide. Delay in diagnosis of patients augments the transmission of infection, and allows progression of disease and more severe disability. Delays in diagnosis greater than ten years have been reported in Brazil. To reduce this delay, it is important to identify factors that hinder patients from presenting to doctors, and those that delay doctors from diagnosing patients once they have presented. This study aimed to explore factors associated with the delayed diagnosis of leprosy in Brazil.

Methodology/ Principal Findings

This is an exploratory study using a self-constructed questionnaire delivered to patients attending three leprosy referral clinics across three states in Brazil. Data were analysed to determine associations between variables and the time taken for participants to present to the health-service, and between variables and the time taken for doctors to diagnose participants once they had presented. Participants who suspected they had leprosy but feared community isolation were 10 times more likely to wait longer before consulting a doctor for their symptoms (OR 10.37, 95% CI 2.18–49.45, p = 0.003). Participants who thought their symptoms were not serious had a threefold greater chance of waiting longer before consulting than those who did (OR 3.114, 95% CI 1.235–7.856, p = 0.016). Forty-two point six per cent of participants reported initially receiving a diagnosis besides leprosy. These had a three times greater chance of receiving a later diagnosis of leprosy compared to those not misdiagnosed or not given a diagnosis (OR 2.867, 95% CI 1.288–6.384, p = 0.010).

Conclusions/ Significance

This study implies a need for patient education regarding leprosy symptoms and the reduction of stigma to encourage patients to present. The high rate of misdiagnosis reported suggests a need to increase clinician suspicion of leprosy. Further education regarding disease symptoms in medical school curriculums may be advisable.     

Field and climate‐based model for predicting the density of host‐seeking nymphal Ixodes scapularis,an important vector of tick‐borne disease agents in the eastern United States

Aim Ixodes scapularis is the most important vector of human tick‐borne pathogens in the United States, which include the agents of Lyme disease, human babesiosis and human anaplasmosis, among others. The density of host‐seeking I. scapularis nymphs is an important component of human risk for acquiring Borrelia burgdorferi, the aetiological agent of Lyme disease. In this study we used climate and field sampling data to generate a predictive map of the density of host‐seeking I. scapularis nymphs that can be used by the public, physicians and public health agencies to assist with the diagnosis and reporting of disease, and to better target disease prevention and control efforts. Location Eastern United States of America. Methods We sampled host‐seeking I. scapularis nymphs in 304 locations uniformly distributed east of the 100th meridian between 2004 and 2006. Between May and September, 1000 m² were drag sampled three to six times per site. We developed a zero‐inflated negative binomial model to predict the density of host‐seeking I. scapularis nymphs based on altitude, interpolated weather station and remotely sensed data. Results Variables that had the strongest relationship with nymphal density were altitude, monthly mean vapour pressure deficit and spatial autocorrelation. Forest fragmentation and soil texture were not predictive. The best‐fit model identified two main foci – the north‐east and upper Midwest – and predicted the presence and absence of I. scapularis nymphs with 82% accuracy, with 89% sensitivity and 82% specificity. Areas of concordance and discordance with previous studies were discussed. Areas with high predicted but low observed densities of host‐seeking nymphs were identified as potential expansion fronts. Main conclusions This model is unique in its extensive and unbiased field sampling effort, allowing for an accurate delineation of the density of host‐seeking I. scapularis nymphs, an important component of human risk of infection for B. burgdorferi and other I. scapularis‐borne pathogens.