Research Articles: Pharmacology and Toxicology Acute toxicity of Nicandra physaloides (L) Gaertn in Cattle and Mice

Nicandra physaloides (L) Gaertn (Solanaceae), commonly known as the ‘apple of Peru’ is widely associated with livestock poisoning. The clinical signs associated with its poisoning in ruminants appear within 6 hours of ingestion and are circling, tremors of the hind limbs, tachycardia, bloat, convulsions, coma and death. However, there is no published information on the toxicology of this plant in Kenya. This study documents Nicandra physaloides toxicity in two different zero-grazed dairy cattle herds that were inadvertently fed on Napier grass contaminated with Nicandra physaloides. In addition to the case studies, the toxicity of the aqueous extracts from the different parts of Nicandra physaloides was studied underexperimental conditions in mice. The 24 hour median lethal dose (LD50) was determined after intra-peritoneal injection (i.p.) of the aqueous extracts of the plant into white Swiss mice and found to be 1820, 2580 and 3620 mg/kg body weight for the leaves, fruits and whole plant respectively. The clinical signs in mice appeared within 30 minutes of inoculation and included coat, decreased locomotor activity, increased respiratory rate, gasping for air and leaping into the air before collapsing into coma and death. There were similarities in the symptoms of the spontaneous poisoning in cattle and in the experimentally induced poisoning in mice.Key words: Acute, Nicandra physaloides, toxicity, cattle, mice

Clinical, Haematological, Biochemical and Pathological Manifestations of Sub-Acute Toxicity of Nicandra Physaloides (L) Gaertn in Calves

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Factors associated with the prescribing of high-dose opioids in primary care: a systematic review and meta-analysis

Background:&nbsp;The risks of harms from opioids increase substantially at high doses, and high-dose prescribing has increased in primary care. However, little is known about what leads to high-dose prescribing, and studies exploring this have not been synthesized. We, therefore, systematically synthesized factors associated with the prescribing of high-dose opioids in primary care. Methods:&nbsp;We conducted a systematic review of observational studies in high-income countries that used patient-level primary care data and explored any factor(s) in people for whom opioids were prescribed, stratified by oral morphine equivalents (OME). We defined high doses as &ge;&thinsp;90 OME mg/day. We searched MEDLINE, Embase, Web of Science, reference lists, forward citations, and conference proceedings from database inception to 5 April 2019. Two investigators independently screened studies, extracted data, and appraised the quality of included studies using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. We pooled data on factors using random effects meta-analyses and reported relative risks (RR) or mean differences with 95% confidence intervals (CI) where appropriate. We also performed a number needed to harm (NNTH) calculation on factors when applicable. Results:&nbsp;We included six studies with a total of 4,248,119 participants taking opioids, of whom 3.64% (n&thinsp;=&thinsp;154,749) were taking high doses. The majority of included studies (n&thinsp;=&thinsp;4) were conducted in the USA, one in Australia and one in the UK. The largest study (n&thinsp;=&thinsp;4,046,275) was from the USA. Included studies were graded as having fair to good quality evidence. The co-prescription of benzodiazepines (RR 3.27, 95% CI 1.32 to 8.13,&nbsp;I2&thinsp;=&thinsp;99.9%), depression (RR 1.38, 95% CI 1.27 to 1.51,&nbsp;I2&thinsp;=&thinsp;0%), emergency department visits (RR 1.53, 95% CI 1.46 to 1.61,&nbsp;I2&thinsp;=&thinsp;0%, NNTH&nbsp;15, 95% CI 12 to 20), unemployment (RR 1.44, 95% CI 1.27 to 1.63,&nbsp;I2&thinsp;=&thinsp;0%), and male gender (RR 1.21, 95% CI 1.14 to 1.28,&nbsp;I2&thinsp;=&thinsp;78.6%) were significantly associated with the prescribing of high-dose opioids in primary care. Conclusions:&nbsp;High doses of opioids are associated with greater risks of harms. Associated factors such as the co-prescription of benzodiazepines and depression identify priority areas that should be considered when selecting, identifying, and managing people taking high-dose opioids in primary care. Coordinated strategies and services that promote the safe prescribing of opioids are needed. Study registration:&nbsp;PROSPERO,&nbsp;CRD42018088057</p

Repellent and mosquitocidal effects of leaf extracts of Clausena anisata against the Aedes aegypti mosquito (Diptera: Culicidae)

Mosquitoes are rapidly developing resistance to insecticides that millions of people relied on to protect themselves from the diseases they carry, thereby creating a need to develop new insecticides. Clausena anisata is used traditionally as an insect repellent by various communities in Africa and Asia. For this study, the repellency and adulticidal activities of leaf extracts and compounds isolated from this plant species were evaluated against the yellow fever mosquito, Aedes aegypti. In the topical application assays, using total bites as an indicator, repellency was dose dependent, with the acetone crude extract (15 %) having 93 % repellence and the hexane fraction (7.5 %) 67 % repellence after 3 h. Fractionation resulted in a loss of total repellence. As mosquito-net treating agents, the acetone and hexane extracts of C. anisata, both at 15 %, had average repellences of 46.89 ± 2.95 and 50.13 ± 2.02 %, respectively, 3 h after exposure. The C. anisata acetone extract and its hexane fraction caused mosquito knockdown and eventually death when nebulised into the testing chamber, with an EC50 of 78.9 mg/ml (7.89 %) and 71.6 mg/ml (7.16 %) in the first 15 min after spraying. C. anisata leaf extracts have potential to be included in protection products against mosquitoes due to the repellent and cidal compounds contained therein.The University of Pretoria and the National Research Foundation.http://link.springer.com/journal/113562017-06-30hb2016Paraclinical Science

Internet-based channel orientation for domesticated services firm: Some drivers and consequences

Undeniably, several studies have reported on both antecedents and the consequents of infusing internet-based channel orientation into the operations of small or micro domesticated firms. However, in the developing and to be precise the African context, such studies are somewhat scant. To address this yearlong theoretical and practical gap, this study takes inspirations from the theoretical underpinnings of both micro-institutional view of the firm as well as resource strategic action. Henceforth, this study supplements the existing internet orientation literature and adds to the on-going debate why internet channel orientation stands as the focal point and engine of survival in small and midsized enterprises. In light of this, this study proposes that entrepreneurial capability of the firm and industry competition predict Internet-based channel orientation (IORIENT) of the firm. Furthermore, the study tests the assumption that the utilisation IORIENT not only potentially contributes to greater market-sensing capability but that it can also indirectly lead to firm competitiveness. Survey data from 198 firms offer initial support for the research propositions. Overall, the research study encourages firms not to only invest in Internet marketing tools but also to effectively use these tools as this is critical to their long-term competitiveness. © 2019, IFIP International Federation for Information Processing