Molecular mechanisms of aluminium neurotoxicity in animal models of Alzheimer’s disease

Alzheimer’s disease (AD) is the most common cause of dementia that affects one patient every seven seconds. With over 35 million people currently affected worldwide, it has been projected that the disease will affect about 115 million people by 2050. The disease is characterized by dysfunctional cellular and molecular networks and/or genomic and epigenomic interactions that affect the normal function of brain cells, leading to a defective cellular communication and function, and ultimately neurodegeneration. Aluminium (Al3+) is the third most abundant ubiquitous element in the earth crust which has gained easy access to humans and extensively used in daily life. It is an essential component of many materials used in households, such as clays, glasses, and alum. An increasing body of evidence implicates Al3+ in the progression of events that lead to neurodegenerative diseases, some of which remains controversial, but it is widely accepted that Al3+ is a recognised neurotoxin that could cause neurodegenerative diseases such as AD. The pathophysiological changes induced in Al3+ neurotoxicity leading to AD result in critical impairments of the central nervous system functions, which are essential for healthy brain ageing. These changes include; axonal transport, neurotransmitter synthesis and synaptic transmission, disruption of calcium homeostasis, alteration of energy metabolism, phosphorylation/dephosphorylation of proteins, protein degradation, gene expression, formation of reactive oxygen species and inflammatory responses, inhibition of DNA repair system, activation of glial cells, reduction of activities of antioxidant enzymes, alterations of pathways of NF-kB and JNK, binding DNA, cell death, motor and cognitive decline. These multi-faceted pathways provide a link between Al neurotoxicity and AD by modulating both tau and amyloid beta hypotheses of AD.Keywords: Alzheimer’s disease, Aluminium chloride, Amyloid beta, Tau, Animal model

Heavy Metal Toxicosis and Male Fertility: The Role of Pentahydroxyflavone Quercetin: a Review

The effect of heavy metals (HMs) has been extensively studied. They cause diverse clinical manifestation through various mechanisms. Male fertility is among the most disturbing effect of HMs affecting family life in human and reproduction in animals. Notably among these effects is interference with the reproductive hormones, morphology and function of reproductive organs, sexual behaviors, and the spermiogram. Quercetin is a dietary flavanoid from edible plants and, has proven pharmacological properties in the treatment and management of many disease conditions. Quercetin ameliorates the adverse effects of HMs on male reproductive hormones by increasing the activity of 3β-hydroxysteroid dehydrogenase (3β- HSD) and 17β-hydroxysteroid dehydrogenase (17β-HSD) in the synthesis of testosterone. Quercetin chelates HMs, scavenge free radicals, and other cytotoxicant capable of disrupting the morphology and function of the male reproductive system. Apart from it neuroprotective activity on the pituitary gland and increased steroidogenesis, quercetin mitigate neurotransmitter that aid in copulation and improve histopathological changes in the brain due to HMs toxicity to improve sexual behavior. Quercetin was also found to be effective in increasing sperm count, daily sperm production, mortility, viability, and also decreased in the percentage of abnormal sperm morphology due to HMs toxicity. In conclusion quercetin was found to be effective in mitigating HMs toxicity that affects male fertility, and so, it is recommended to be incorporated into the treatment and management of HMs toxicity. Individuals who are at risk of HMs toxicity should take dietary plants that contain quercetin to minimize the effects of these metals

Gross, histological and histomorphometric studies on the thyroid gland of one humped camel (Camelus dromedarius) found in the semi-arid region of North Eastern Nigeria

Thyroid glands are endocrine glands present in all mammals and secretes thyroxin, triiodothyronine and calcitonin as its major hormones which plays important role in metabolism, regulation of energy and nutrient absorption, as well as calorigenesis and normal reproductive function. We studied the thyroid gland of one humped camel found in the Northeastern part of Nigeria. A total of 18 pairs of thyroid glands(10 female and 8 male) were randomly collected from apparently healthy camels’ slaughtered at the Maiduguri municipal abattoir and were used for the studies. Grossly, the thyroid glands of both the male and the female camel studied appeared reddish brown in colour and irregular in shape. There was a significant difference (p<0.05) between the weights and lengths of the male and female thyroid gland with the female higher than the male on both parameters. Histologically, the thyroid gland studied is covered by a thick fibrous connective tissue capsule and consists of numerous follicles of various sizes. Lining the follicles are squamous to low cuboidal cells with basally located round or spherical nucleus. The area of the nucleus of the male thyroid gland (380.06 ± 20.484μm) was slightly greater than that of the female (366.09 ± 29.45μm). For the epithelial height and follicular diameter, the female thyroid gland showed a slight increase (49.597 ± 1.459μm and 362.16 ± 21.820μm respectively) compare to the male (48.75 ± 1.414μm and 363.93 ± 21.624μm respectively). Presence of parafollicular cells and fibroblast in this gland were also noted.Keywords: Thyroid gland, parafollicular cells, colloid, gross, histomorphometric

Seroprevalence of infectious bursal disease virus antibodies in some species of poultry in Maiduguri, Nigeria

This study was aimed at determining the antibodies of IBDV in some poultry species in Maiduguri, Nigeria. A total of 944 serum samples were collected from village chickens, broilers, layers, ducks, turkeys and geese in Maiduguri and tested for IBDV antibodies using inzyme linked Immunosorbent assay (ELISA) and a seroprevalence of 46.6% was recorded. The species distribution showed that 33.4% of local chickens (134/401), 67.3% of layers (35/52), 50.8% of broilers (159/313), 60.6% of turkeys (77/127), 65.5% of ducks (19/29) and 72.7% of geese (16/22) sampled were positive for IBDV antibodies. Males showed a seroprevalence of 70% while females recorded 30%. IBDV seropositive sera showed that samples from broilers reacted with 31.5% middle OD values and turkeys with 9.4% middle OD values. Samples from other species reacted with lower OD values. Samples from other species reacted with lower OD values. Presence of IBDV antibodies in species other than chickens suggested that different bird species might have IBDV and could serve as reservoirs for IBDV transmission. Because of this threat to poultry industry, there is need for continuous surveillance of IBDV in all poultry species so as to institute effective preventive measures against the disease.Keywords: ELISA, Infectious bursal disease virus, IgG, Poultry species, Serum sample

TReND in Africa: Toward a Truly Global (Neuro)science Community.

TReND is a volunteer-scientist run charity dedicated to promoting research and education on the African continent. Focusing on neuroscience, we discuss approaches to address some of the factors that currently stifle Africa's scientific development and our experience in implementing them

The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications

Background: The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications. Methods: ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery. Results: The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784. Conclusions: This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance. © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.Medical Research Council of South Africa gran