Sustainable education and training in laboratory animal science and ethics in low- and middle-income countries in Africa - challenges, successes, and the way forward.

Despite the recognised need for education and training in laboratory animal science (LAS) and ethics in Africa, access to such opportunities has historically been limited. To address this, the Pan-African Network for Laboratory Animal Science and Ethics (PAN-LASE) was established to pioneer a support network for the development of education and training in LAS and ethics across the African continent.In the 4.5 years since the establishment of PAN-LASE, 3635 individuals from 28 African countries have participated in our educational activities. Returning to their home institutions, they have both established and strengthened institutional and regional hubs of knowledge and competence across the continent. Additionally, PAN-LASE supported the development of guidelines for establishment of institutional Animal Ethics Committees, a critical step in the implementation of ethical review processes across the continent, and in enhancing animal welfare and scientific research standards.Key challenges and opportunities for PAN-LASE going forward include the formalisation of the network; the sustainability of education and training programmes; implementation of effective hub-and-spoke models of educational provision; strengthening governance frameworks at institutional, national and regional levels; and the availability of Africa-centric open access educational resources.Our activities are enhancing animal welfare and the quality of animal research undertaken across Africa, enabling African researchers to undertake world-leading research to offer solutions to the challenges facing the continent. The challenges, successes and the lessons learnt from PAN-LASE's journey are applicable to other low- and middle-income countries across the world seeking to enhance animal welfare, research ethics and ethical review in their own country or region.

Successful experimental infant baboon model for childhood cryptosporidiosis studies.

BACKGROUND: Cryptosporidiosis causes high morbidity and mortality in children under 2 years of age globally. The lack of an appropriate animal model that mimics the pathogenesis of disease in humans has hampered the development and testing of potential therapeutic options. This study aimed to develop and validate an infant baboon infection model of cryptosporidiosis. METHODS: Eighteen immunocompetent weaned infant baboons aged 12 to 16 months were used. The animals were n = 3 controls and three experimental groups of n = 5 animals each inoculated with Cryptosporidium parvum oocysts as follows: group 1: 2 × 104, group 2: 2 × 105, group 3: 2 × 106 followed by daily fecal sampling for oocyst evaluation. Blood sampling for immunological assay was done on the day of infection and weekly thereafter until the end of the experiment, followed by necropsy and histopathology. Statistical analysis was performed using R, SPSS, and GraphPad Prism software. Analysis of variance (ANOVA) and Bonferroni post hoc tests were used for comparison of the means, with p < 0.05 considered as a significant difference. Correlation coefficient and probit analysis were also performed. RESULTS: In all experimental animals but not controls, the onset of oocyst shedding occurred between days 2 and 4, with the highest oocyst shedding occurring between days 6 and 28. Histological analysis revealed parasite establishment only in infected animals. Levels of cytokines (TNF-α, IFN-γ, and IL-10) increased significantly in experimental groups compared to controls. CONCLUSION: For developing a reproducible infant baboon model, 2 × 104 oocysts were an effective minimum quantifiable experimental infection dose.

Oral administration of Coenzyme Q10 protects mice against oxidative stress and neuro-inflammation during experimental cerebral malaria.

In animal model of experimental cerebral malaria (ECM), the genesis of neuropathology is associated with oxidative stress and inflammatory mediators. There is limited progress in the development of new approaches to the treatment of cerebral malaria. Here, we tested whether oral supplementation of Coenzyme Q10 (CoQ10) would offer protection against oxidative stress and brain associated inflammation following Plasmodium berghei ANKA (PbA) infection in C57BL/6 J mouse model. For this purpose, one group of C57BL/6 mice was used as control; second group of mice were orally supplemented with 200 mg/kg CoQ10 and then infected with PbA and the third group was PbA infected alone. Clinical, biochemical, immunoblot and immunological features of ECM was monitored. We observed that oral administration of CoQ10 for 1 month and after PbA infection was able to improve survival, significantly reduced oedema, TNF-α and MIP-1ß gene expression in brain samples in PbA infected mice. The result also shows the ability of CoQ10 to reduce cholesterol and triglycerides lipids, levels of matrix metalloproteinases-9, angiopoietin-2 and angiopoietin-1 in the brain. In addition, CoQ10 was very effective in decreasing NF-κB phosphorylation. Furthermore, CoQ10 supplementation abrogated Malondialdehyde, and 8-OHDG and restored cellular glutathione. These results constitute the first demonstration that oral supplementation of CoQ10 can protect mice against PbA induced oxidative stress and neuro-inflammation usually observed in ECM. Thus, the need to study CoQ10 as a candidate of antioxidant and immunomodulatory molecule in ECM and testing it in clinical studies either alone or in combination with antimalaria regimens to provide insight into a potential translatable therapy.

Blocking central pathways in the primate motor system using high-frequency sinusoidal current.

Electrical stimulation with high-frequency (2-10 kHz) sinusoidal currents has previously been shown to produce a transient and complete nerve block in the peripheral nervous system. Modeling and in vitro studies suggest that this is due to a prolonged local depolarization across a broad section of membrane underlying the blocking electrode. Previous work has used cuff electrodes wrapped around the peripheral nerve to deliver the blocking stimulus. We extended this technique to central motor pathways, using a single metal microelectrode to deliver focal sinusoidal currents to the corticospinal tract at the cervical spinal cord in anesthetized adult baboons. The extent of conduction block was assessed by stimulating a second electrode caudal to the blocking site and recording the antidromic field potential over contralateral primary motor cortex. The maximal block achieved was 99.6%, similar to findings of previous work in peripheral fibers, and the optimal frequency for blocking was 2 kHz. Block had a rapid onset, being complete as soon as the transient activation associated with the start of the sinusoidal current was over. High-frequency block was also successfully applied to the pyramidal tract at the medulla, ascending sensory pathways in the dorsal columns, and the descending systems of the medial longitudinal fasciculus. High-frequency sinusoidal stimulation produces transient, reversible lesions in specific target locations and therefore could be a useful alternative to permanent tissue transection in some experimental paradigms. It also could help to control or prevent some of the hyperactivity associated with chronic neurological disorders.

Nuclear organization of cholinergic, putative catecholaminergic and serotonergic systems in the brains of five microchiropteran species.

The current study describes, using immunohistochemical methods, the nuclear organization of the cholinergic, catecholaminergic and serotonergic systems within the brains of five microchiropteran species. For the vast majority of nuclei observed, direct homologies are evident in other mammalian species; however, there were several distinctions in the presence or absence of specific nuclei that provide important clues regarding the use of the brain in the analysis of chiropteran phylogenetic affinities. Within the five species studied, three specific differences (presence of a parabigeminal nucleus, dorsal caudal nucleus of the ventral tegmental area and the absence of the substantia nigra ventral) found in two species from two different families (Cardioderma cor; Megadermatidae, and Coleura afra; Emballonuridae), illustrates the diversity of microchiropteran phylogeny and the usefulness of brain characters in phylogenetic reconstruction. A number of distinct differences separate the microchiropterans from the megachiropterans, supporting the diphyletic hypothesis of chiropteran phylogenetic origins. These differences phylogenetically align the microchiropterans with the heterogenous grouping of insectivores, in contrast to the alignment of megachiropterans with primates. The consistency of the changes and stasis of neural characters with mammalian phylogeny indicate that the investigation of the microchiropterans as a sister group to one of the five orders of insectivores to be a potentially fruitful area of future research.

Nuclear organization of cholinergic, putative catecholaminergic and serotonergic systems in the brains of two megachiropteran species.

The nuclear organization of the cholinergic, putative catecholaminergic and serotonergic systems within the brains of the megachiropteran straw-coloured fruit bat (Eidolon helvum) and Wahlberg's epauletted fruit bat (Epomophorus wahlbergi) were identified following immunohistochemistry for cholineacetyltransferase, tyrosine hydroxylase and serotonin. The aim of the present study was to investigate possible differences in the nuclear complement of the neuromodulatory systems of these species in comparison to previous studies on megachiropterans, microchiropterans and other mammals. The nuclear organization of these systems is identical to that described previously for megachiropterans and shows many similarities to other mammalian species, especially primates; for example, the putative catecholaminergic system in both species presented a very compact nucleus within the locus coeruleus (A6c) which is found only in megachiropterans and primates. A cladistic analysis of 38 mammalian species and 82 characters from these systems show that megachiropterans form a sister group with primates to the exclusion of other mammals, including microchiropterans. Moreover, the results indicate that megachiropterans and microchiropterans have no clear phylogenetic relationship to each other, as the microchiropteran systems are most closely associated with insectivores. Thus a diphyletic origin of Chiroptera is supported by the present neural findings.