Bacterial structural genomics target enabled by a recently discovered potent fungal acetyl-CoA synthetase inhibitor.

The compound ethyl-adenosyl monophosphate ester (ethyl-AMP) has been shown to effectively inhibit acetyl-CoA synthetase (ACS) enzymes and to facilitate the crystallization of fungal ACS enzymes in various contexts. In this study, the addition of ethyl-AMP to a bacterial ACS from Legionella pneumophila resulted in the determination of a co-crystal structure of this previously elusive structural genomics target. The dual functionality of ethyl-AMP in both inhibiting ACS enzymes and promoting crystallization establishes its significance as a valuable resource for advancing structural investigations of this class of proteins.

Isolation, characterisation and complement fixation activity of acidic polysaccharides from Argemone mexicana used as antimalarials in Mali.

CONTEXT: Global studies on Argemone mexicana L. (Papaveraceae) traditionally used against malaria in Mali are limited to its low-mass compounds activities, and little information on its bioactive polysaccharides is available. OBJECTIVE: This study determines the structure and the immunomodulatory activity of polysaccharides from aerial parts of A. mexicana. MATERIALS AND METHODS: Acidic polysaccharides from this plant material named HMAmA1 and HMAmA2 were isolated from water extracts. Their monosaccharide composition was determined by gas chromatography. Glycosidic linkages were determined using GC-MS. NMR was also applied. The polymers were tested for effects on the human complement system in vitro at different doses. RESULTS: The monosaccharide composition showed that the two polysaccharides contained in different amounts the following monomers: arabinose, rhamnose, galactose, and galacturonic acid. Overall structural analysis showed the presence of a low ratio of 1,2-linked rhamnose compared to 1,4-linked galacturonic acid with arabinogalactans substituted on position 4 of rhamnose. NMR data showed the presence of galacturonans alternated by rhamnogalacturonans bearing arabinose and galactose units. α-Linkages were found for l-arabinose, l-rhamnose and d-galacturonic acid, while ß-linkages were found for d-galactose. The two polysaccharides exhibited strong complement fixation activities, with HMAmA1 being the highest potent fraction. ICH50 value of HMAmA1 was 5 µg/mL, compared to the control BPII being 15.9 µg/mL. DISCUSSION AND CONCLUSIONS: Polysaccharides form A. mexicana presented a complement fixation effect. The complement system is an important part of the immune defense, and compounds acting on the cascade are of interest. Therefore, these polymers may be useful as immunodulatory agents.

Traditional Kenyan herbal medicine: exploring natural products' therapeutics against schistosomiasis.

Praziquantel (PZQ) remains the only drug of choice for the treatment of schistosomiasis, caused by parasitic flatworms. The widespread use of PZQ in schistosomiasis endemic areas for about four decades raises concerns about the emergence of resistance of Schistosoma spp. to PZQ under drug selection pressure. This reinforces the urgency in finding alternative therapeutic options that could replace or complement PZQ. We explored the potential of medicinal plants commonly used by indigenes in Kenya for the treatment of various ailments including malaria, pneumonia, and diarrhoea for their antischistosomal properties. Employing the Soxhlet extraction method with different solvents, seven medicinal plants Artemisia annua, Ajuga remota, Bredilia micranta, Cordia africana, Physalis peruviana, Prunus africana and Senna didymobotrya were extracted. Qualitative phytochemical screening was performed to determine the presence of various phytochemicals in the plant extracts. Extracts were tested against Schistosoma mansoni newly transformed schistosomula (NTS) and adult worms and the schistosomicidal activity was determined by using the adenosine triphosphate quantitation assay. Phytochemical analysis of the extracts showed different classes of compounds such as alkaloids, tannins, terpenes, etc., in plant extracts active against S. mansoni worms. Seven extracts out of 22 resulted in <20% viability against NTS in 24 h at 100 µg/ml. Five of the extracts with inhibitory activity against NTS showed >69.7% and ≥72.4% reduction in viability against adult worms after exposure for 24 and 48 h, respectively. This study provides encouraging preliminary evidence that extracts of Kenyan medicinal plants deserve further study as potential alternative therapeutics that may form the basis for the development of the new treatments for schistosomiasis.

Structural Characterization of the Reaction and Substrate Specificity Mechanisms of Pathogenic Fungal Acetyl-CoA Synthetases.

Acetyl CoA synthetases (ACSs) are Acyl-CoA/NRPS/Luciferase (ANL) superfamily enzymes that couple acetate with CoA to generate acetyl CoA, a key component of central carbon metabolism in eukaryotes and prokaryotes. Normal mammalian cells are not dependent on ACSs, while tumor cells, fungi, and parasites rely on acetate as a precursor for acetyl CoA. Consequently, ACSs have emerged as a potential drug target. As part of a program to develop antifungal ACS inhibitors, we characterized fungal ACSs from five diverse human fungal pathogens using biochemical and structural studies. ACSs catalyze a two-step reaction involving adenylation of acetate followed by thioesterification with CoA. Our structural studies captured each step of these two half-reactions including the acetyl-adenylate intermediate of the first half-reaction in both the adenylation conformation and the thioesterification conformation and thus provide a detailed picture of the reaction mechanism. We also used a systematic series of increasingly larger alkyl adenosine esters as chemical probes to characterize the structural basis of the exquisite ACS specificity for acetate over larger carboxylic acid substrates. Consistent with previous biochemical and genetic data for other enzymes, structures of fungal ACSs with these probes bound show that a key tryptophan residue limits the size of the alkyl binding site and forces larger alkyl chains to adopt high energy conformers, disfavoring their efficient binding. Together, our analysis provides highly detailed structural models for both the reaction mechanism and substrate specificity that should be useful in designing selective inhibitors of eukaryotic ACSs as potential anticancer, antifungal, and antiparasitic drugs.

Screening barrier plants to reduce crop attack by sweet potato weevil (Cylas formicarius).

BACKGROUND: Sweet potato weevil, Cylas formicarius (Fabricius) attacks stems and storage roots of sweet potato, Ipomoea batatas, and is a major pest of this globally significant crop. To minimize the immigration of weevils into sweet potato fields from nearby donor habitat, we assessed scope for a barrier plant approach. Here, we report a novel, two-stage, multiple choice olfactometer method to screen candidate barrier plant species and a field study of the effects of shortlisted barrier plants of weevil movement and plant damage. RESULTS: Initial work established that a combination of sweet potato foliage and storage root was significantly more attractive to adult C. formicarius than either tissue alone in the distal chamber of choice arms. Among 15 candidate barrier plant species in intermediate chambers in arms, spring onion, oregano, chilli, basil, sweetcorn, fennel, lime mint and lemongrass significantly reduced passage of C. formicarius. Of these, sweetcorn and lime mint significantly reduced the numbers of oviposition holes in sweet potato storage roots. A field study showed that basil and chives were effective barrier plants for reducing weevil damage to sweet potato storage roots. CONCLUSION: Our method has utility for screening additional candidate plants, and suggests that weevil dispersal and subsequent oviposition are affected by passage through some plants, suggesting scope for barrier plants to contribute to the management of this major pest. © 2019 Society of Chemical Industry.

Cytochrome P450 Mono-Oxygenase and Resistance Phenotype in DDT and Deltamethrin-Resistant Anopheles gambiae (Diptera: Culicidae) and Culex quinquefasciatus in Kosofe, Lagos, Nigeria.

Pyrethroids and DDT are key insecticides in the control of malaria, yellow fever, and lymphatic filariasis vectors. Knockdown and metabolic resistance mechanisms have been proven to be important in determining the efficacy of insecticides. Here we investigated cytochrome P450 as a resistance mechanism in Anopheles gambiae Giles and Culex quinquefasciatus Say exposed to deltamethrin and DDT. Two- to three-days-old adult female mosquitoes were used for insecticide exposures and PBO synergistic assays using WHO standard guidelines, kits and test papers (DDT 4%, deltamethrin 0.05%, and PBO 4%). Polymerase chain reaction (PCR) assays were used for the identification of the species and for characterization of the kdr allele. Mortality at 24 h post-exposure was 18 and 17% in An. gambiae s.s. exposed to DDT and deltamethrin, respectively; 1 and 5% in Cx. quinquefasciatus exposed to DDT and deltamethrin respectively. Significant (P < 0.01) levels of susceptibility was recorded in mosquitoes pre-exposed to PBO, as KDT50 and 24 h of exposure ranged from 37.6 min to 663.4 min and 27 to 80%, respectively. Presence of a knockdown resistance allele was recorded in An. gambiae s.s., 22.5% for homozygote resistance and 7.5% for heterozygotes, while Cx. quinquefasciatus populations showed no kdr allele despite the high level of resistance to DDT and deltamethrin. Findings from this study indicated that cytochrome P450 mono-oxygenase expression is highly implicated in the resistance phenotype to DDT and pyrethroids in An. gambiae and Cx. quinquefasciatus in the study area.

Skinfold thickness in normoglycemic offspring of patients with t2dm on graded exercise

It is uncertain if exercise can influence the occurrence of T2DM in offspring of diabetic parents. Therefore this study was designed to assess the effect of exercise on skinfold thickness of offspring of T2DM parents compared with those of non-diabetic parents. This study involved convenience sampling of 50 offspring of T2DM parents attending University College Hospital, Ibadan and 50 offspring of nondiabetic parents who were undergraduate students of the University of Ibadan, Nigeria. Participants were randomly assigned into four groups using convenience sampling method: 25 Normal-weight Offspring of Non-Diabetic Parents (NONDP), 25 Normal-weight Offspring of Diabetic Parents (NODP), 25 Overweight Offspring of Non-Diabetic Parents (OONDP) and 25 Overweight Offspring of Diabetic Parents (OODP). Each participant followed a protocol of graded exercise using the "Tummy trimmer" everyday spending 30-45 minutes daily for 24 weeks. 4 sites of skinfold thickness (supra-iliac, Biceps, Triceps and sub-scapula) were measured by skinfold caliper. Weight and Body Mass Index (BMI) were estimated using standard methods at baseline, 6 weeks, 12 weeks, 18 weeks and 24 weeks, respectively. Data were analyzed using descriptive statistic and repeated ANOVA with p-value at n less than 0.05. The results indicate that compared to baseline, there were reductions at the four sites of skinfold thickness measurements (supra-iliac, Biceps, Triceps and sub-scapular). At supra-iliac site, skinfold thickness in NONDPreductions was from 7.16 mm ± 2.02 to 6.60 mm ± 4.40. The reduction trend for supra-iliac, Biceps, triceps and subscapular skinfold sites in NONDP were 0.56 mm, 0.79 mm, 1.66 mm and 0.19 mm respectively. While the reduction trend for supra-iliac, Biceps, triceps and subscapular skinfold sites in OODP were 0.56 mm, 1.10 mm, 2.06 mm and 1.52 mm respectively. At subscapular site, the average skinfold thickness reduction trend was 0.19 mm in control group 1.53 mm in test group. Thus, graded exercise reduced skinfold thickness in all the groups. The clinical importance of this in prevention of DM among offspring of diabetic parents is quite promising

Obstetric outcome of ethnic Turkish women in London: a retrospective case-control study.

There is concern that the maternal mortality in ethnic minority women is significantly greater than that of Caucasian British women. The objective of this study was to compare the demographic and obstetric outcomes between these two groups. Data were collected retrospectively over a 2-year period from 148 index and 148 control cases. The study group had statistically similar maternal age, labour duration, blood loss and mode of delivery compared with Caucasian British women (p > 0.05). A total of 68% of Turkish women spoke little or no English; were more likely to be non-smokers and also more likely to be married to unemployed spouses (p = 0.0001). This is the first study comparing obstetric outcomes of immigrant Turkish women with their Caucasian British counterparts. There was no significant difference in maternal or fetal outcomes, which could be attributed to the 'healthy migrant' theory, coupled with increased vigilance in ethnic minority pregnancies.

Local knowledge and socio-economic determinants of traditional medicines' utilization in livestock health management in Southwest Nigeria.

Smallholder livestock farmers in Nigeria utilize traditional medicines derived from medicinal plants (PMs) for the maintenance of their animals' health. This study was designed to determine the PMs used in the study area and their level of utilization by livestock farmers, compare the level of utilization of PMs across the three states surveyed and identify the socio-economic factors influencing farmer's utilization of PMs. Thirty-five PMs were identified. Farmers had considerable knowledge about the identified PMs but about 80.0% of them used the PMs to poor/moderate extent. There were statistical differences in the utilization level of PMs among the three states. Six socio-economic variables were found to be statistically significant in influencing PMs' utilization. Farmer's age, household size, distance to the nearest veterinary hospital/clinic and extent of travels, had positive effects while negative effects were exhibited by farm income and number of heads of livestock. It was concluded that there was considerable knowledge about PMs and that utilization of PMs varied between the three states. It was recommended that local knowledge of PMs be preserved in the study area through screening and documentation.

Effect of adrenaline on glucose uptake in the rabbit small intestine.

OBJECTIVES: Previous study had shown that nicotine acts on blood glucose through release of adrenaline. While there are reports on the hyperglyceic effect of adrenaline in rabbits, there is no information on the effect of adrenaline on intestinal glucose uptake of rabbits. The present study was carried out to find out if adrenaline has any effect on glucose uptake in the rabbit small intestine. MATERIALS AND METHODS: Experiments were carried out on fasted anaesthetized male rabbits. Five groups of rabbits (6 rabbits per group) were studied. A vein draining a segment of the upper jejunum was cannulated for blood flow and venous glucose measurements. The left femoral artery and vein were cannulated for arterial blood sampling and drug infusion respectively. Glucose uptake was calculated as a product of jejunal blood flow and the glucose difference between arterial (A) and venous (V) blood. RESULTS: The fasting venous blood glucose levels were 151.8 +/- 4.4mg/dl and 164.0 + 2.3mg/dl in Groups I and V that were not given adrenoceptor blockers. The upper jejunum had a resting (or basal) glucose uptake of 38.3 +/- 1.6mg/min in the control group. When adrenaline (2ug/kg) was injected intravenously, arterial blood glucose rose from a basal value of 245.5 +/- 4.6mg/dl to 307.5+4.7mg/dl at the peak of response while venous glucose rose from 151.8+4.4mg/dl to 275.8 +/- 4.2mg/dl at the peak of response. Glucose uptake increased to 107.4 +/- 2.5mg/ min at the peak of response. The hyperglycaemic response to adrenaline injection was abolished by propranolol but not by prazosin indicating that this effect of adrenaline is mediated through beta adrenoceptor. Both prazosin and propranolol reduced considerably adrenaline-induced increase in blood flow and glucose uptake, prazosin being more potent in flow reduction. CONCLUSION: This study showed that the resting small intestine of rabbits took up large amounts of glucose. The intestinal glucose uptake was markedly increased by adrenaline injection. The response to adrenaline was mediated through alpha and beta adrenoceptors. The responses to adrenaline are different in many respects from those induced by nicotine in rabbits in our earlier study. The reason for the differences is obscure.

Preparation and use of plant medicines for farmers' health in Southwest Nigeria: socio-cultural, magico-religious and economic aspects.

Agrarian rural dwellers in Nigeria produce about 95% of locally grown food commodities. The low accessibility to and affordability of orthodox medicine by rural dwellers and their need to keep healthy to be economically productive, have led to their dependence on traditional medicine. This paper posits an increasing acceptance of traditional medicine country-wide and advanced reasons for this trend. The fact that traditional medicine practitioners' concept of disease is on a wider plane vis-à-vis orthodox medicine practitioners' has culminated in some socio-cultural and magico-religious practices observed in preparation and use of plant medicines for farmers' health management. Possible scientific reasons were advanced for some of these practices to show the nexus between traditional medicine and orthodox medicine. The paper concludes that the psychological aspect of traditional medicine are reflected in its socio-cultural and magico-religious practices and suggests that government should fund research into traditional medicine to identify components of it that can be integrated into the national health system.

Effect of nicotine on glucose uptake in the rabbit small intestine.

A technique for measuring glucose uptake in the small intestine of rabbits was developed. Using this technique, the glucose uptake in the resting jejunum of rabbits and the effect of nicotine infusion on glucose uptake were studied. Experiments were carried out on fasted anaesthetized male rabbits. Four groups of rabbits (6 per group) were studied. A vein draining segment of the upper jejunum was cannulated for blood flow and venous glucose measurements. The left femoral artery and vein were cannulated for arterial blood sampling and drug infusion respectively. Glucose uptake was calculated as a product of jejunal blood flow and the (A-V) glucose difference. The fasting blood glucose levels were 101.0 +/- 8.4 mg/dl and 127.0 +/- 11.3 mg/dl before and after anaesthesia respectively. Basal blood glucose was much higher than this following surgery. The upper jejunum had a resting glucose uptake of 24.1 +/- 7.0 mg/min. When nicotine (50 ug/kg) was infused intravenously, blood glucose rose from a basal value of 253.8 +/- 9.5 mg/dl to 379.8 +/- 20.3 mg/dl at the peak of response. Glucose uptake increased to 73.1 +/- 11.3 mg/min at the peak of response. These effects of nicotine are mediated through both beta and alpha adrenoceptors. Comparison with previous studies in dogs and rats showed that different adrenoceptors are involved in nicotine hyperglycaemia in fasted dogs, rats and rabbits.

Ectodermal odontogenic tumours: analysis of 197 Nigerian cases.

This article presents a clinico-pathologic analysis of 197 cases of ectodermal odontogenic tumours archived in the Lagos University Teaching Hospital, Lagos Nigeria over a 21-year period. They were categorized according to the WHO classification of odontogenic tumours. Of the 197 cases, 182 (92.3%) were benign while 15 (7.6%) were malignant. Central ameloblastoma, which accounted for 88.3% in this series, was the most common benign neoplasm demonstrating predilection for males (58.6%) and the mandible (83.3%). The mean age of occurrence (+/-SD) was 31.00 +/- 13.9 (range 9-82 years). Similarly ameloblastic carcinoma was the most prevalent malignant tumour (5.6%) with a predilection for females (63.6%) and the mandible (81.8%). The mean age of occurrence (+/-SD) was 30.1+/- 20.7 (range 16-85) years. Follicular ameloblastoma was found to be the commonest histologic subtype seen in Nigeria.

Anaplastic carcinoma of the parotid gland: a case report of a patient disease free after nine years. Follow-up.

A case of massive anaplastic carcinoma of the left parotid gland in a 29-year old female Nigerian, of Yoruba tribe, for which radical left parotidectomy with external carotid artery ligation and post-operative radiotherapy was performed is presented Nine years post-operatively, no evidence of recurrence or metastasis was found. The patient is in apparent good health, despite the amount of tumour spillage that was experienced intra-operatively. As far as we have been able to check, it is to our knowledge the first of such from Nigeria.

A retrospective study of oral cysts in Nigerian children.

A retrospective analysis of oral cysts that were seen over an 11-year period in children at a dental institution in Nigeria was carried out. In general, oral cysts accounted for only 2.6% of the total biopsied lesions during the period under review. The most common oral cysts were the mucous retention cysts, the gingival cysts of infants and the dentigerous cyst. The commonest sites were the maxilla, the mandible and the floor of the mouth respectively and there was no significant difference in sex preference. Most of the cases were seen in the age group 11-16 years while the least was in the group aged 6-10 years.

Immunohistochemical localization of Epstein-Barr virus receptor on hyperplastic gingiva of kidney allotransplant patient immunocompromised by cyclosporin A.

The strong association between Epstein-Barr Virus (EBV) and certain tumours of the oro-maxillo-laryngeal region aroused our present interest. A pre-requisite for the molecular interplay of oncogenesis by EBV is the expression of the EBV receptor on the target cell of the host. As a possible contribution to this concept, we adopted immunohistochemical technique to examine a hyperplastic gingival tissue obtained from a subject on kidney allotransplant immunosuppressed with cyclosporin A (CSA). Our results demonstrate expression of EBV/C3d receptor on the superficial layers of the hyperplastic gingiva but absent in the basal/parabasal layers. It is suggested that the superficial layer expression of EBV/C3d receptor could be due to direct acquisition from the environment of the oral cavity rather than a systemic extension from the deep layers of the same epithelium.

Distribution of oral tumors in Nigerian children based on biopsy materials examined over an 11-year period.

A survey of biopsied lesions of patients aged 0-16 yr who presented with oral swellings at the Lagos University Teaching Hospital over a period of 11 yr was conducted to determine the pattern of presentation of these lesions in 203 Nigerian children, 123 boys and 80 girls. 21% of the lesions were fibro-osseous lesions. There were more non-odontogenic than odontogenic tumors and very few salivary gland tumors.

Burkitt's lymphoma of the jaws in Lagos. Ten-year review.

This paper presents a review of Burkitt's lymphoma of the jaws seen at the Lagos University Teaching Hospital. The debate on certain aspects of the disease, particularly the pathogenesis, has also been reviewed, while the experience gained in the management has been included.