A liquid chromatographic method for the simultaneous determination of amlodipine, valsartan and hydrochlorothiazide in tablets

A simple, rapid, sensitive, specific, accurate, precise and fast high performance liquid chromatographic method for the determination of antihypertensive drugs amlodipine, valsartan and hydrochlorothiazide singly or in combination was developed and validated. Separation of the analytes was achieved on a Hypersil C-18 (250 mm × 4.6 mm, 5 μm) column using a mobile phase consisting of acetonitrile-KH2PO4 pH 3.0- water (75:6:19 % v/v/v) delivered at 1 ml/min, UV detection at 229 nm and 40 oC column temperature. The precision of the method was demonstrated through repeatability (coefficient of variation = 0.298-0.724) as well as intermediate precision (coefficient of variation = 0.435-1.412). The detector response was linear over the 25-150 % range with R2 ≥ 0.99 for each of the three analytes. The limit of detection for hydrochlorothiazide, valsartan and amlodipine were 10.72, 21.20 and 14.45 ng, while the limits of quantification were 35.76, 71.23 and 48.16 ng, respectively. The method showed satisfactory robustness and accuracy with a recovery of 99.7-100.6 %. The method was applied in the assay of 6 commercial products containing drugs under study. The results obtained revealed quality problems among the samples analyzed.Keywords: HPLC, amlodipine, valsartan, hydrochlorothiazide, antihypertensive

Phytosterols from Dombeya torrida (J. F. Gmel.)

Dombeya torrida collected from Kinale forest in Kiambu County, Kenya, was Soxhlet extracted with chloroform and by percolation using a  dichloromethane:methanol mixture. The extracts were fractionated using normal phase silica gel in an open column. Five compounds were isolated namely friedelin, friedelan-3β-ol, α-sitosterol, taraxerol and stigmasterol. This is the first report of isolation of these compounds from Dombeya torrida. The isolated compounds were identified by means of 1H-NMR, 13C-NMR, DEPT, MS and IR analyses.Key words: Dombeya torrida, friedelin, friedelan-3β-ol, β-sitosterol, stigmasterol, taraxerol

Prevalence and Antimicrobial Susceptibility of Enterobacteriaceae Collected from Patients with Wounds at Kenyatta National Hospital, Nairobi, Kenya

Prevalence and sensitivity trends of Enterobacteriaceae isolated from septic wounds were determined through a prospective cross sectional study. One hundred and fifteen specimens isolated from in-patients in the Department of Orthopaedics were studied and antibiotic sensitivity testing performed using the Kirby and Bauer disc diffusion technique. The prevalence of organisms isolated was Proteus spp (33.9%), Eschericia coli (13.2%), Klebsiella spp (7.9%), Alcaligenes (1.7%), Citrobacter freundii (0.9%), Serratia spp (0.9%) and Acinetobacter baumanii (0.9%). The sensitivity rate of ceftriaxone, ceftazidime and ciprofloxacin was above 70% in all cases. Co-amoxiclav, gentamicin, cefuroxime, minocycline and piperacillin showed moderate to high activity. Klebsiella spp isolates portrayed high resistance against several drugs. The sensitivity patterns showed that empirical prescribing should be discouraged since the organisms appear to be developing resistance against commonly used antibiotics.Keywords: Sensitivity trends, Prevalence, Enterobacteriaceae, antimicrobial susceptibilityEast and Central African Journal of Pharmaceutical Sciences Vol. 12 (2009) 42-4

Antimicrobial Activity and Bioactive Constituents of Alectra sessiliflora (Vahl) Kuntze Methanol Extract

Alectra sessiliflora (Vahl) Kuntze (Scrophulariaceae) is traditionally used in western Kenya in the management of microbial infections. The water, chloroform and methanol extracts of A. sessiliflora whole plant exhibited antimicrobial activity against a range of bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Shigella dysenteriae and Bacillus pumilus) and fungi (Candida albicans, Aspergillus niger and Cryptococcus neoformans). The methanol extract exhibited the highest activity with minimum inhibitory concentration (MIC) of 3.13-6.25 and 3.13-12.5 mg/ml for bacteria and fungi, respectively. Chromatographic fractionation of the methanol extract through non-polar D101 macroporous resin beads yielded three bioactive compounds: two phenolic compounds, p-coumaric acid and 3,4-dihydroxybenzoic acid, and a flavonoid, luteolin. The compounds exhibited appreciable activities against tested bacteria and fungi with MIC values ranging from 0.13 to 0.25 and 0.13 to 0.50 mg/ml, respectively. These constituents might be responsible either individually or collectively for the traditional use of the plant to manage bacterial and fungal ailments. The in vitro antimicrobial activity and isolation of bioactive compounds from this plant are being reported for the first time.Key words: Alectra sessiliflora, ethnomedicine, antibacterial and antifungal activity, bioactive constituent

Acute and Sub-Acute Toxicity of Dichloromethane-Methanol Root Bark Extract of Teclea trichocarpa Engl. (Rutaceae) in Rats

The in vivo toxicity profile of dichloromethane-methanol (50:50 % v/v) extract of Teclea trichocarpa Engl. (Rutaceae) root bark using Wister rats is reported. No death occurred in the oral acute and sub-acute toxicity studies. In the acute intraperitoneal test, all the animals at 2000 mg/kg developed convulsions followed by death within 3 min; at 300 mg/kg, death occurred within 4-48 h, but there was no death at 50 mg/kg. In the acute oral, subacute oral and 50 mg/kg acute intraperitoneal tests, all haematological and biochemistry parameters fluctuated but remained within normal limits, suggesting that T. trichocarpa root bark extract is practically non-toxic and supports the safety of this plant as a traditional herbal remedy. However, toxicity of the extract on intraperitoneal administration requires further study.Key words: Teclea trichocarpa, root bark extract, acute toxicity, sub-acute toxicit

Agrobacterium-mediated transformation of common bean

The common bean ( Phaseolus vulgaris L.) is an important human dietary constituent being a rich source of protein. Genetically improved bean varieties are required as optimum yields are not realised due to constraints such as diseases and insect pests. The objective of this study was to evaluate the potential of two common bean varieties Mwitemania and Rose coco to in vitro Agrobacterium tumefaciens - mediated transformation. Mature seed embryos germinated for 1-2 days on moist filter paper, were stab inoculated with A. tumefaciens strains LBA 4404 (pBI 121), EHA 105 (pCAMBIA 1201) and EHA 105 (pCAMBIA 1301), harbouring \u3b2-glucuronidase (GUS) intron plasmids. The infected embryos were co-cultivated for 3-4 days on basal Murashige and Skoog, 1962 medium with B5 vitamins (MSB5) or medium supplemented with 10 \ub5M benzyl-aminopurine (BAP) and cultured on regeneration and selection medium consisting of 10 \ub5M BAP and 50 mg L-1 kanamycin or hygromycin. Transformed shoots and roots confirmed by histochemical staining for GUS activity were obtained in 40 weeks old Mwitemania plantlets from explants infected with A. tumefaciens LBA 4404 (pBI 121). No GUS expression was observed in all Rose coco and Mwitemania shoots from explants infected with EHA 105 (pCAMBIA 1201) or EHA 105 (pCAMBIA 1301).Le haricot commun ( Phaseolus vulgaris L.) est un important constituant du regime alimentaire humain riche en prot\ue9ines. Des vari\ue9t\ue9s g\ue9n\ue9tiquement am\ue9lior\ue9es sont n\ue9cessaires, les rendements optimum n\u2019\ue9tant pas realis\ue9s suite aux contraintes comme maladies et pestes dues aux insects. L\u2019objectif de cette \ue9tude \ue9tait d\u2019\ue9valuer le potential de deux vari\ue9t\ue9s de haricot commun, Mwitemania et Rose coco en transformation m\ue9di\ue9e in vitro Agrobacterium tumefaciens . De grains embryonnaires matures en germination sous papier filter pendant 1-2 jours, \ue9taient inocul\ue9s en stab avec des strains de LBA 4404 (pBI 121) A. tumefaciens, EHA 105 (pCAMBIA 1201) et EHA 105 (pCAMBIA 1301), harbouring \u3b2-glucuronidase (GUS) "intron plasmids". Lews embryons infect\ue9s \ue9taient c0-cultiv\ue9s pendant 3-4 jours sur la base de media Murashige and Skoog, 1962 avec des vitamins B5 (MSB5) ou media suppl\ue9ment\ue9 avec 10mM benzyl-aminopurine (BAP) et cultiv\ue9 sur le m\ue9dia s\ue9lectionn\ue9 et r\ue9g\ue9n\ue9r\ue9 compos\ue9 de 10 mM BAP et 50 mg L-1 kanamycin ou hygromycin. Les tiges et racines transform\ue9es, confirm\ue9es par la culture histochimique pour activit\ue9 GUS \ue9taient obtenues dans les plantules de Mwitemania \ue2g\ue9es de 40 semaines issues des explants infect\ue9s avec A. tumefaciens LBA 4404 (pBI 121). Aucune expression GUS n\u2019\ue9tait observ\ue9e dans toutes les tiges de Rose coco et Mwitemania shoots issues des explants infect\ue9s avec EHA 105 (pCAMBIA 1201) ou EHA 105 (pCAMBIA 1301)

Cultural and contextual adaptation of mental health measures in Kenya: An adolescent-centered transcultural adaptation of measures study

Introduction: There is paucity of culturally adapted tools for assessing depression and anxiety in children and adolescents in low-and middle-income countries. This hinders early detection, provision of appropriate and culturally acceptable interventions. In a partnership with the University of Nairobi, Nairobi County, Kenyatta National Hospital, and UNICEF, a rapid cultural adaptation of three adolescent mental health scales was done, i.e., Revised Children’s Anxiety and Depression Scale, Patient Health Questionnaire-9 and additional scales in the UNICEF mental health module for adolescents. Materials and methods: Using a qualitative approach, we explored adolescent participants’ views on cultural acceptability, comprehensibility, relevance, and completeness of specific items in these tools through an adolescent-centered approach to understand their psychosocial needs, focusing on gender and age-differentiated nuances around expression of distress. Forty-two adolescents and 20 caregivers participated in the study carried out in two primary care centers where we conducted cognitive interviews and focused group discussions assessing mental health knowledge, literacy, access to services, community, and family-level stigma. Results: We reflect on process and findings of adaptations of the tools, including systematic identification of words adolescents did not understand in English and Kiswahili translations of these scales. Some translated words could not be understood and were not used in routine conversations. Response options were changed to increase comprehensibility; some statements were qualified by adding extra words to avoid ambiguity. Participants suggested alternative words that replaced difficult ones and arrived at culturally adapted tools. Discussion: Study noted difficult words, phrases, dynamics in understanding words translated from one language to another, and differences in comprehension in adolescents ages 10–19 years. There is a critical need to consider cultural adaptation of depression and anxiety tools for adolescents. Conclusion: Results informed a set of culturally adapted scales. The process was community-driven and adhered to the principles of cultural adaptation for assessment tools

Expressed centromere specific histone 3 (CENH3) variants in cultivated triploid and wild diploid bananas (Musa spp.)

Open Access JournalCentromeres are specified by a centromere specific histone 3 (CENH3) protein, which exists in a complex environment, interacting with conserved proteins and rapidly evolving satellite DNA sequences. The interactions may become more challenging if multiple CENH3 versions are introduced into the zygote as this can affect post-zygotic mitosis and ultimately sexual reproduction. Here, we characterize CENH3 variant transcripts expressed in cultivated triploid and wild diploid progenitor bananas. We describe both splice- and allelic-[Single Nucleotide Polymorphisms (SNP)] variants and their effects on the predicted secondary structures of protein. Expressed CENH3 transcripts from six banana genotypes were characterized and clustered into three groups (MusaCENH-1A, MusaCENH-1B, and MusaCENH-2) based on similarity. The CENH3 groups differed with SNPs as well as presence of indels resulting from retained and/or skipped exons. The CENH3 transcripts from different banana genotypes were spliced in either 7/6, 5/4 or 6/5 exons/introns. The 7/6 and the 5/4 exon/intron structures were found in both diploids and triploids, however, 7/6 was most predominant. The 6/5 exon/introns structure was a result of failure of the 7/6 to splice correctly. The various transcripts obtained were predicted to encode highly variable N-terminal tails and a relatively conserved C-terminal histone fold domain (HFD). The SNPs were predicted in some cases to affect the secondary structure of protein by lengthening or shorting the affected domains. Sequencing of banana CENH3 transcripts predicts SNP variations that affect amino acid sequences and alternatively spliced transcripts. Most of these changes affect the N-terminal tail of CENH3

Cost-Effective PCR-Based Identification of Tunga penetrans (Siphonaptera) Larvae Extracted from Soil Samples Containing PCR Inhibitor-Rich Material

Tungiasis is a neglected tropical disease caused by skin-penetrating female Tunga penetrans fleas. Although tungiasis causes severe health problems, its ecology is poorly understood and morphological descriptions of the larvae are unavailable. To identify T. penetrans immature stages and sites where they develop, diagnostic PCRs are required. However, flea larvae feed on soil organic matter rich in PCR inhibitors. Here, three DNA preparation methods, including a soil DNA kit that removes inhibitors, a simple ammonium acetate precipitation approach (AmAcet) and a crude lysate of larvae (CL), were combined with amplification by the highly processive FIREPol® Taq or the inhibitor-resistant Phusion® polymerase. Independent of the polymerase used, the frequency of successful amplification, Cq values and PCR efficacies for the low-cost CL and AmAcet methods were superior to the commercial kit for amplification of a 278 bp partial internal transcribed spacer-2 (ITS-2) and a 730 bp pan-Siphonaptera cytochrome oxidase II PCR. For the CL method combined with Phusion® polymerase, the costs were approximately 20-fold lower than for the methods based on the soil DNA kit, which is a considerable advantage in resource-poor settings. The ITS-2 PCR did not amplify Ctenocephalides felis genomic or Tunga trimammilata ITS-2 plasmid DNA, meaning it can be used to specifically identify T. penetrans

Quality Control Report of Drugs Analyzed in the Drug Analysis and Research Unit during the Period 2011-2015

During the period 2011-2015, the Drug Analysis and Research Unit (DARU) analyzed 1972 drug samples. The samples consisted of 21.5% locally manufactured and 78.2% imported products while the origin of 0.3% of products was indeterminate. Samples were subjected to compendial and/or in-house analytical specifications. The overall non-compliance rate was 4.5% comprising 2.5% local products and 2.0% imports. High failure rates were recorded for uterotonics (37.5%), hemostatics (33%), anthelmintics (17%) and anticancers (10.5%) while ophthalmic, immunomodulatory, musculoskeletal and endocrine drugs all complied with the quality acceptance criteria. Erectile dysfunction drugs, received by the laboratory for the first time, all complied with specifications. The results obtained demonstrate an improvement in the quality of samples submitted to DARU when compared to previous performance