Search

The comet assay is a versatile method to detect nuclear DNA damage in individual eukaryotic cells, from yeast to human. The types of damage detected encompass DNA strand breaks and alkali-labile sites (e.g., apurinic/apyrimidinic sites), alkylated and oxidized nucleobases, DNA–DNA crosslinks, UV-induced cyclobutane pyrimidine dimers and some chemically induced DNA adducts. Depending on the specimen type, there are important modifications to the comet assay protocol to avoid the formation of additional DNA damage during the processing of samples and to ensure sufficient sensitivity to detect differences in damage levels between sample groups. Various applications of the comet assay have been validated by research groups in academia, industry and regulatory agencies, and its strengths are highlighted by the adoption of the comet assay as an in vivo test for genotoxicity in animal organs by the Organisation for Economic Co-operation and Development. The present document includes a series of consensus protocols that describe the application of the comet assay to a wide variety of cell types, species and types of DNA damage, thereby demonstrating its versatility.

Marine fisher communities of Kwale in the South Coast of Kenya have, for generations, depended nearly exclusively on fisheries and fish-based livelihoods. In recent times, dwindling fish catch has threatened their livelihoods. Diversification of livelihood sources is touted as a potential remedy, but much less is understood about the available alternative sustainable options and their viability. This study examined the potency and viability of the alternative livelihood options for the fishermen communities. It used a cross-sectional descriptive survey design premised on mixed qualitative and quantitative methods to collect and analyse the data from 346 randomly selected households. Emerging livelihood options with potency for adoption include apiculture, seaweed farming, agriculture, small business enterprises and mangrove conservation, among others. Preference is given to supplemental livelihood sources as opposed to alternative livelihoods. Implications for policy include the need for public extension services and training to invigorate households’ income.

DNA damage can lead to carcinogenic mutations and toxicity that promotes diseases. Therefore, having rapid assays to quantify DNA damage, DNA repair, mutations, and cytotoxicity is broadly relevant to health. For example, DNA damage assays can be used to screen chemicals for genotoxicity, and knowledge about DNA repair capacity has applications in precision prevention and in personalized medicine. Furthermore, knowledge of mutation frequency has predictive power for downstream cancer, and assays for cytotoxicity can predict deleterious health effects. Tests for all of these purposes have been rendered faster and more effective via adoption of fluorescent readouts. Here, we provide an overview of established and emerging cell-based assays that exploit fluorescence for studies of DNA damage and its consequences.

Pregnant women in settings with high HIV prevalence are at increased risk of HIV acquisition and subsequent vertical transmission. We implemented and evaluated a novel programme to provide pre-exposure prophylaxis (PrEP) in maternal and child health clinics in Kenya.

Small-scale fisheries in Kenya contribute about 4.7% of the Gross Domestic Product (GDP) in spite of high post-harvest losses. Post-harvest interventions in fisheries enable fishers and fish processors to reduce waste, maintain nutritional aspects and meet stringent demands in food quality and safety. This review highlights the benefits and pitfalls of various fish post-harvest management interventions in order to drive policy dialogue and formulation of a regulatory framework for future interventions. It relies on data obtained from the Kenya Marine and Fisheries Research Institute and the State Department of Fisheries and Blue Economy. Results depict abundant interventions in both handling and processing, but low utilization (<40% of installed cold rooms, dryers and smoking kilns) and multiplication by fishing communities. Fish products that target export markets have well-organized structures. However, a weak regulatory framework is a key constraint in addressing post-harvest management of fish intended for the domestic market. Under-utilization of installed interventions results in continued waste of fish, contributing to food and nutritional insecurity. This review recommends the development of an effective and integrative policy framework that involves interactions across different domains, institutional mechanisms that monitor and address those interactions, analytical bases for decision making, and multi-stakeholder dialogue for post-harvest management. Such policies will enhance the adoption of post-harvest technology in small-scale fisheries in Kenya and elsewhere.

Sugar content is an important component of fruit quality. Although sugar transporters are known to be crucial for sugar accumulation, the role of genes encoding SWEET sugar transporters in fruit sugar accumulation remains elusive. Here we report the effect of the SWEETgenes on fruit sugar accumulation in apple. A total of 25 MdSWEETgenes were identified in the apple genome, and 9 were highly expressed throughout fruit development. Molecular markers of these 9 MdSWEETgenes were developed and used for genotyping of 188 apple cultivars. The association of polymorphic MdSWEETgenes with soluble sugar content in mature fruit was analyzed. Three genes, MdSWEET2e, MdSWEET9b, and MdSWEET15a, were significantly associated with fruit sugar content, with MdSWEET15aand MdSWEET9baccounting for a relatively large proportion of phenotypic variation in sugar content. Moreover, both MdSWEET9band MdSWEET15aare located on chromosomal regions harboring QTLs for sugar content. Hence, MdSWEET9band MdSWEET15aare likely candidates regulating fruit sugar accumulation in apple. Our study not only presents an efficient way of implementing gene functional study but also provides molecular tools for genetic improvement of fruit quality in apple-breeding programs. Insights into the mechanisms that drive fruit sugar content in apples could help develop and breed apple trees with improved fruit quality. The transportation of sugars throughout fruit plants plays a vital role both in healthy plant development and in the quality of the fruit produced. However, the mechanisms inherent in fruit sugar accumulation are not yet fully understood. Yuepeng Han at the Chinese Academy of Sciences in Wuhan, China, and co-workers sought to clarify the role of genes encoding SWEETsugar transporters in the cultivated apple, Malus x domesticaBorkh. They identified 25 SWEETgenes in the apple genome, with 9 of these highly expressed during fruit development. Han’s team narrowed these genes down to two that were highly associated with the regulation of sugar content in the fruit.

SummaryExplanatory models of illness – the way people perceive, interpret and respond to it – are mediated not only by the illness itself, but also by cultural and social contexts. This article discusses recent evidence showing how the exploration of explanatory models can help to shape treatment and outcomes for some of the most common categories of mental illness, and presents case studies illustrating dilemmas clinicians face when their explanatory models differ from those of their patients. It concludes with recommendations on how a culturally sensitive clinical approach based on the exploration of explanatory models during assessment and treatment can be used as an effective way of dealing with the complexity of patients' and families' needs.Learning Objectives• Appreciate the use of explanatory models in clinical practice• Understand the relevance of explanatory models in relation to specific diagnostic categories of mental illness• Recognise that dilemmas may arise if the explanatory models of the clinician and the patient differ, and be able to manage this tension

Five new orbitides, cyclolinopeptides 21–25, were identified in flaxseed oil (Linum usitatissimum) extracts. Their HPLC-ESIMS quasimolecular ion peaks at m/z1097.7 (21), 1115.6 (22), 1131.6 (23), 1018.6 (24), and 1034.6 (25) [M + H]+corresponded to the molecular formulae C59H89N10O10, C58H87N10O10S, C58H87N10O11S, C53H80N9O9S, and C53H80N9O10S, respectively. Their structures were elucidated by extensive HPLC-ESIMS/MS analyses, and their presence was confirmed by precursor proteins identified in flax genomic DNA sequence data. The amino acid sequences of these orbitides were confirmed as [1–10-NαC]-GILVPPFFLI, [1–10-NαC]-GMLIPPFFVI, [1–10-NαC]-GOLIPPFFVI, [1–9-NαC]-GMLVFPLFI, and [1–9-NαC]-GOLVFPLFI for cyclolinopeptides 21–25, respectively. Previously reported orbitides, [1–9-NαC]-ILVPPFFLI (1), [1–9-NαC]-MLIPPFFVI (2), [1–9-NαC]-OLIPPFFVI (3), [1–8-NαC]-MLVFPLFI (7), and [1–8-NαC]-OLVFPLFI (8), were also present in flaxseed oil. The precursors of orbitides 21, 22, and 24also produced orbitides 1, 2, and 7by alternative cyclization. Cyclolinopeptides 3, 8, 23, and 25contain MetO (O) and are not directly encoded, but are products of post-translational modification of the Met present in 2, 7, 22, and 24, respectively. Sufficient cyclolinopeptide 23was isolated for characterization via 1D (1H and 13C) and 2D (NOESY and HMBC) NMR spectroscopy. These compounds have been named as cyclolinopeptides U, V, W, X, and Y for 21, 22, 23, 24, and 25, respectively.

A broad theoretical framework centred on an ecosystem approach is used to investigate the local knowledge around contraction and transmission of HIV-1/AIDS amongst the Turkana of Lodwar township. According to the Turkana, there are several naturalistic factors that influence the contraction and transmission of HIV-1/AIDS. Broad categories can be identified: factors that encourage unprotected sex, those that encourage mobility and migration (associated with the pursuit of casual sexual partnerships), factors of social organization that encourage risky sex, factors related to deficient healthcare, and socioeconomic factors.

Due to an overlap in symptoms, there is significant delay in surgical treatment of patients that have concomitant multiple sclerosis (MS) and degenerative cervical Myelopathy (DCM). The purpose of this review is to evaluate if surgical intervention is beneficial to patients that have concurrent presentations.

Lake Naivasha is a wetland of national and international importance. However, it is under constant anthropogenic pressures, which include the quest for socioeconomic development within the lake ecosystem itself as well as other activities within the catchment. The lake is an important source of fresh water in an otherwise water-deficient zone. It supports a thriving fishery, an extensive flower-growing industry and geothermal power generation. It is home to a wide range of aquatic and terrestrial flora and fauna, including vegetation, birds, fish and mammals. The adjacent area is ideal for horticulture, which plays a crucial role in the development of both the local and national economy, providing employment to more than 30 000 people. The Lake Naivasha area produces up to 70% of Kenya's total horticultural output and contributes significant foreign exchange to the national economy. However, the lake and its surrounding areas are fragile ecosystems that face increasing threats from irrigated agriculture, water abstraction, the fast-growing Naivasha Township, and human population growth throughout the basin. Agricultural and livestock farming activities within the 3 376km2catchment area are also a threat to the lake ecosystem. This paper reviews some of the adverse socioeconomic activities that exert pressure on the lake, as well as bioindicator data that may be useful in assessing the overall quality of the lake as an important wetland ecosystem.

Sulfadoxine-pyrimethamine (SP) and co-trimoxazole were both effective in reducing fever, clearing parasitaemia and improving anaemia in children aged <5 years with uncomplicated malaria in 2 Kenyan endemic sites, Oyugis in the west and Tiwi on the coast. We compared the efficacy of these 2 regimens (in May–July 1998) by evaluating clinical and parasitological responses over 14 days. The combined incidence of parasitological failure for the combined sites for co-trimoxazole was 14/123 (11%) and for SP 23/145 (16%) (RR 0·72, 95% confidence interval [CI] 0·31–1·46, P= 0·289). The 14-day clinical failure rate for the combined sites for co-trimoxazole was 4/123 (3·3%), and for SP 8/145 (5·5%), (RR 1·69, 95% CI 0·91–3·15, P= 0·129). The results indicate that the risk of treatment failure for the 2 regimens was similar. The antimalarial use of co-trimoxazole in uncomplicated malaria needs further investigation, since the 10–12-h elimination half-life of both components should reduce selective pressure for resistance. In addition, use of a 2-day high-dose course, tested previously, requires further study to demonstrate its efficacy.

Objective Cleft lip/palate (CLP) is a common human congenital defect in which the maxillary lateral incisors are often absent, malformed, and malpositioned. The present study was designed to examine the origin of the upper primary lateral incisor relative to the medial nasal process (MNP) and maxillary process (MP) fusion area and to the premaxillary/maxillary (incisive) suture in monkeys.Method Scanning electron microscopy, histology, skeletal staining, and drying techniques were used to study facial development in embryo and fetal monkey specimens. A teratogenic dose of cyclophosphamide was administered to pregnant monkeys prior to fusion of the MNP and MP and fetuses were examined for CLP.Results Formation of the anterior maxilla involved fusion of the MNP and MP at stages 14–18. At stages 18–20, the palatal portion of the MNP had formed the medial and lateral incisive mounds. By stage 22, the upper primary lateral incisor has formed within the MP, lateral to the MNP/MP fusion area and to the ossifying premaxilla. Ossification of the premaxilla begins in the MNP and subsequently spreads laterally across the MNP/MP fusion area into the MP. Accordingly, the lateral incisor undergoes a complex positional shift (mainly medial) relative to the incisive suture both prenatally and postnatally and is finally located medial to the suture. Examination of the cyclophosphamide-induced CLP fetuses showed that the lateral incisor is located lateral to the alveolar cleft and does not shift medial to the incisive suture.Conclusion Understanding the origin of the lateral incisor (the tooth closest to the cleft) and the shift after its formation provides clues to high incidence of malformations and ectopia of this incisor in cleft patients.

This study examined developmental changes in fetal membranes and placenta of Cercopithecus aethiops from a Carnegie developmental stage 12 embryo to nearterm fetuses. Ultrastructurally, yolk sac cells (endoderm and mesothelium) were similar to comparable stages in other primates. Endodermal cells had few apical microvilli, abundant rough-endoplasmic reticulum, electron dense mitochondria and dense bodies. In contrast, mesothelial cells were squamous with numerous microvilli, small mitochondria and a few short strands of rough endoplasmic reticulum. Amnion cells early in gestation were squamous with few microvilli, large glycogen deposits and poorly developed cytoplasmic components. Tight junctions and desmosomes held adjacent cells together. The basal surface was smooth and the basal lamina was distinct. As development proceeded the amniotic cells became cuboidal and possessed numerous microvilli. Cytoplasmic organelles were better developed and glycogen deposits increased by mid-gestation. A thick layer of microfibrils and collagen fibers was prominent below the basal lamina. Near-term, the glycogen had virtually disappeared and the amount of lipid droplets increased. Basal infoldings and podocytic processes and the extracellular matrix had increased. The smooth chorion consisted of pseudostratified columnar cells. Cells had short microvilli, numerous granules and vesicles of variable size and electron density in early gestation. With increasing age, amounts of granules and vesicles decreased, as the endoplasmic reticulum became prominent. The chorionic trophoblast was a continuous layer in mid-pregnancy and its cells had well-developed organelles and inclusions. Late in gestation, the trophoblastic layer became discontinuous and wide intercellular spaces and channels were present. In the placenta, the trophoblastic elements showed features characteristic of primate placenta.

Abstract: Mean daytime serum levels of testosterone (T) and luteinizing hormone (LH) were determined in eight male thick-tailed bush babies at different times of the day by radioimmunoassay and leydig cell bioassay respectively. Blood samples were obtained twice a week from each animal at different times of the day between 08:30 and 16:00. This was carried out for a period of eight weeks. There was significantly higher mean serum T levels in the morning compared to evening hours (p<0.05). There was no significant variation in mean serum LH levels, and no significant correlation between serum T and LH levels.

An adult female goat with rare malformations, which consisted of duplication of the intestinal, lower urinary, and genital tracts as well a pair of parasitic appendages, is presented. A complete dissection was performed on a moribund female goat (Capra hircus). The animal had a normal body with a parasitic attachment located within the pelvic region. This attachment was represented by an ovoid, trunk-like, adipose mass that lacked internal organs or vertebrae but that had two fairly well-developed limbs with the normal components of hind limbs. There was duplication involving the external and internal genitalia, the urethra, the urinary bladder, and portions of the small intestine as well as the large bowel, including the anal openings. An autosite with a duplication involving the hindgut and paramesonephric anlages was identified. These features were compatible with life in utero and postutero and emanated from incomplete twinning (heteropagus twins). A review of the literature also suggests that heteropagus twins are a very rare abnormality in both domestic animals and humans. Anat. Rec. 247:432–438, 1997 © 1997 Wiley-Liss, Inc.

Sessile drops of aqueous electrolyte as well as cationic and anionic surfactant solutions are placed on the lower plate of a stainless steel parallel plate capacitor and the variation of static advanced contact angles with the field strength between the plates is monitored. Even at field strengths where changes in electrical body forces are negligible, these drops spreads outward, irreversibly, in response to variations in the externally applied potential gradient. Contact angles always decrease, regardless of the polarity of the applied electric field. However, the magnitude of the change is sensitive to both the polarity and strength of the field. These angles relax over time scales that are an order of magnitude higher than that predicted by diffusional resistance alone. The variation in solution surface tension in response to the externally applied electric field has been obtained experimentally from the drop shapes. For both ionic surfactant and simple electrolyte solutions, the surface tension always decreases as the electric field is increased, regardless of its polarity. For sessile drops placed on a stainless steel plate having a passivating oxide layer, reductions in both the liquid-vapour and solid-liquid interfacial energy must occur to account for the observed changes in contact angle (provided Young's equation is assumed to be valid). However, for drops place on platinum coated stainless steel plates, the changes in contact angles are entirely accounted for by changes in surface tension only, implying that the solid-liquid interfacial energy does not vary with the external field.

ABSTRACTThe Structured Operational Research Training Initiative (SORT-IT) has been shown to be very effective in strengthening capacity for conducting operational research, publishing in scientific journals and fostering policy and practice change. The ‘classic’ model includes three face-to-face modules during which, respectively, a study protocol, a data analysis plan, and a manuscript are elaborated. Meanwhile, the lectures of the SORT-IT are available online as YouTube videos. Given the availability of this online material and the experiences with online mentorship of the faculty, we piloted a first blended distance/residential SORT-IT. To inform future implementers of our experience with blended operational research courses, we summarize the model, successes, and challenges of this approach in this perspective paper. The blended SORT-IT consisted of an online phase, covering modules 1 and 2, followed by a face-to-face writing module 3. Four out of six participants successfully completed the course, and submitted a manuscript to a peer-reviewed journal within four weeks of completing module 3. A blended approach may make the SORT-IT course more accessible to future participants and may favour the adoption of the course by other institutions, such as national Ministries of Health.

Hezbon Owiti est un jeune peintre du Kenya. Dans l'essai qui accompagne les gavures et les peintures reproduites ici et sur les couvertures de notre revue, ses remarques originales le révèlent comme artiste et comme homme.

No relevant conflicts of interest to declare.

Abstract 1781