Quantitative analysis and postsynaptic targets of GABA-immunoreactive boutons within the rat trigeminal motor nucleus

We have used the post-embedding immunogold labelling method using antibodies to gamma-aminobutyric acid (GABA) to obtain quantitative data on the distribution, frequency, postsynaptic targets and ultrastructural characteristics of GABA-immunoreactive (GABA-IR) boutons in the trigeminal motor nucleus of rats. We have also combined this method with horseradish peroxidase tracing to obtain specific evidence for termination of some GABA-IR boutons onto identified jaw-elevator motoneurones. Twenty-eight percent of all synapses in the motor nucleus involved GABA-IR boutons. Seventy-three percent of the GABA-IR boutons formed axo-dendritic synapses, 13% axo-somatic synapses and 14% axo-axonic synapses. Ninety-three percent of GABA-IR boutons formed symmetrical synapses. Overall, 58% of all boutons contained only flattened vesicles, while 26% contained round vesicles and 16% a mixture of vesicle types. Measurements of bouton cross sectional area, apposition length, and active zone length were obtained from serial reconstructions of 15 GABA-IR boutons and 30 unlabelled boutons. In each case mean values for GABA-IR boutons were significantly smaller than those for nonlabelled boutons.     

Examining subjective well-being among older adults using pain medications

Purpose

To examine the relationship between social participation and subjective well-being (SWB) among older adults using pain medications and evaluate the impact of sex on this relationship.

Methods

A cross-sectional analysis was conducted using the 2019 National Health and Aging Trends Study data, a nationally-representative sample of Medicare beneficiaries 65 years and older. Individuals were included if they reported taking pain medications for five days or more per week over the last month. Social participation was operationalized using the sum score of four items: visiting family and friends, going out for enjoyment, attending religious services, and participation in other organized activities. SWB was operationalized as a latent variable using four items reflecting positive and negative emotions, and three items reflecting self-evaluation. Structural equation modeling was used to test the relationship between key study constructs, as well as the moderating effect of sex on the relationship between social participation and SWB.

Results

A total of 964 (weighted N?=?7,660,599) participants were included in the study. Most participants were female (61.3%), White (81.0%), community-dwelling (94.9%) older adults. Confirmatory factor analysis showed appropriate fit for SWB. Social participation had a statistically significant association with SWB (unstandardized regression coefficient?=?0.133; 95% CI 0.071, 0.196; p?<?0.001) after adjusting for covariates. However, this relationship was not moderated by sex (p?=?0.836).

Conclusion

Social participation is positively and significantly associated with SWB among older adults using pain medications. Interventions aimed at improving SWB should consider incorporating a social activities component.

     

Analysis of risk and protective factors for psychosocial distress among in-school adolescents in Tanzania

Introduction

Psychosocial distress has emerged as one of the world’s major public health problems, especially among adolescents in both low- and middle-income countries. This study used data from the 2015 version of the Global School-Based Health Survey to determine the risk and protective factors for psychosocial distress among in-school adolescents in Tanzania.

Materials and methods

Chi-square and logistic regression analyses were used to estimate the magnitude of associations. A total of 2936 students participated in the study, of which 52.3% were female.

Results

Psychosocial distress was found in 16.9% of the students at similar rates for both males and females. The risk factors associated with psychosocial distress were hunger (OR?=?1.57, p?<?0.001), being bullied (OR?=?1.92, p?<?0.001), being attacked (OR?=?1.31, p?<?0.05), engaging in physical activity (OR?=?1.33, p?<?0.05), truancy (OR?=?1.28, p?<?0.05) and tobacco use (OR?=?2.40, p?<?0.01). However, the protective factors were grade (OR?=?0.55, p?<?0.01) and having one or two (OR?=?0.56, p?<?0.01) and three or more close friends (OR?=?0.57, p?<?0.01).

Conclusions

The prevalence of psychosocial distress among adolescents in Tanzania is relatively high and appears to be common among both sexes. To reduce psychosocial distress among in-school adolescents, more attention needs to be paid to the risk factors whiles encouraging healthy relationships among adolescents and their close friends.

     

Assessment of formulated amodiaquine microparticles in Leishmania donovani infected rats

The aim of this study was to formulate, characterise and evaluate the activity of amodiaquine microparticles against Leishmania donovani. Microparticles were formulated by encapsulating the drug in bovine serum albumin using the spray-dryer method. The microparticles were evaluated for size, zeta potential, drug content, encapsulation efficiency and in vitro release profile. The size range of the microparticles formulated was between 1.9 and 10?μm with an average zeta potential of ?25.5?mV. Of the expected 20% drug loading, an average of 18.27% was obtained giving an encapsulation efficiency of 91.35%. Pharmacokinetic profile of amodiaquine improved with microencapsulation of the drug with C_max, AUC_0→48 and t_1//2 all significantly higher than amodiaquine solution. Amodiaquine microparticles showed an overall higher bioavailability and hence were more effective in eliminating intra-tissue parasites than the drug solution. It would therefore be expected that the formulated microparticles will be more effective in treating visceral leishmaniasis.     

Estimating least-developed countries’ vulnerability to climate-related extreme events over the next 50 years

When will least developed countries be most vulnerable to climate change, given the influence of projected socio-economic development? The question is important, not least because current levels of international assistance to support adaptation lag more than an order of magnitude below what analysts estimate to be needed, and scaling up support could take many years. In this paper, we examine this question using an empirically derived model of human losses to climate-related extreme events, as an indicator of vulnerability and the need for adaptation assistance. We develop a set of 50-year scenarios for these losses in one country, Mozambique, using high-resolution climate projections, and then extend the results to a sample of 23 least-developed countries. Our approach takes into account both potential changes in countries’ exposure to climatic extreme events, and socio-economic development trends that influence countries’ own adaptive capacities. Our results suggest that the effects of socio-economic development trends may begin to offset rising climate exposure in the second quarter of the century, and that it is in the period between now and then that vulnerability will rise most quickly. This implies an urgency to the need for international assistance to finance adaptation.     

Development of membrane-based tests for the detection of urinary antigens and antibodies in human toxoplasmosis: preliminary studies in Ghanaian patients

Two membrane-based ELISA systems were used in detecting Toxoplasma antigens and anti-Toxoplasma antibodies in urine samples collected from 54 ophthalmology (22 suggestive active and 32 suggestive past infection) patients and 26 pregnant women attending obstetrics/gynaecology clinic (OGP), suspected of toxoplasmosis by eye examination, past medical records and questionnaire, respectively, in Ghana from mid-February to April 2002. The antigen detecting ELISA was able to demonstrate antigen in 100% (22/22) ophthalmology (active infection) and 62.5% (20/32) ophthalmology (past infection) patients, and 42% (11/26) of OGP which included 3 that were sero-negative prior to and during this study, giving an overall prevalence of 66.3% (53/80). The urinary antigen positive samples also included 6 that were negative for both the Dye Test (DT) and latex agglutination test (LAT). Antigen was not detected in the urine of 22 normal (sero-negative for antibodies to Toxoplasma) individuals. The membrane-based urinary antibody detecting sandwich ELISA also detected anti-Toxoplasma antibodies in 100% (22/22) of ophthalmology (active infection) and 81.3% (26/32) of ophthalmology (past infection) patients, a total of 89% (48/54); and 80.8% (21/26) of OGP with an overall prevalence of 86.3% (69/80), including 7 ophthalmology patients' samples that were sero-negative for both DT and LAT. Antibody sero-positivity of the samples was determined by DT as 87% (47/54) in ophthalmology patients and 73.1% (19/26) in pregnant women, LAT as 85.2% (46/54) and 65.4% (17/26), and an overall prevalence as 82.5% (66/80) and 78.8% (63/80), respectively. The membrane-based ELISA systems appear promising but need to be investigated further for its efficacy as reliable diagnostic tests.