Effect of insulin on visuo-spatial memory and histology of cerebral cortex in the presence or absence of nitric oxide inhibition

Insulin has emerged from its traditional ‘peripheral’ glucose-lowering function to become increasingly regarded as a brain hormone that controls a wide range of functions including learning and memory. Insulin action on learning and memory is linked to nitric oxide (NO) signalling, but its effects on memory and histology of cerebral cortex in conditions of varied NO availability is unclear. This research sought to determine the effect of insulin on visuo-spatial learning, memory and histology of cerebral cortex during NO deficiency. Twenty-four mice weighing 21-23 g, were divided into four groups (n = 6) and treated daily for seven days with 0.2 ml distilled water subcutaneously (s.c.) (control), 10 I.U/kg insulin s.c., 10 I.U/kg insulin + 50 mg/kg L-NAME intraperitoneally (i.p.), and 50 mg/kg i.p. L-NAME s.c., respectively. The 3-day MWM paradigm was used to assess memory. Brain tissue was examined for histological changes. There was no significant difference between day 1 and day 2 latencies for all the groups. The mice in all (but L-NAME) groups spent more time in the target quadrant, and the difference was significant within but not between groups. There was significant reduction in number of platform site crossings (4.83 ± 0.5, 0.67 ± 0.3, 0.50 ± 0.3 and 0.50 ± 0.3 for control, insulin, insulin+L-NAME and L-NAME groups, respectively) in all the groups compared to control. Normal histology of the cortex and absence of histological lesions were observed in brain slides of control and treatment groups. It was concluded that insulin administration impairs visuo-spatial memory to a greater extent in the presence of NO block, and to a lesser extent in the absence of NO block. Nitric oxide has a role in insulin-induced memory impairment. Insulin administration in the presence or absence of NO block had no effect on histology of cortex.Keywords: Insulin, learning and memory, cortical histology, nitric oxid

Flore bactérienne de la vessie urinaire chez des bovins à Zaria, Nigeria

Les auteurs ont rendu compte de la flore bactérienne de la vessie urinaire chez 40 bovins abattus à l'abattoir de Zaria au Nigeria. Dix isolats bactériens ont été identifiés. Staphylococcus aureus, avec une prévalence de 22,5 % était l'isolat le plus fréquemment rencontré. Parmi les échantillons examinés, 16 (40 %) avaient une apparence trouble et, parmi ces derniers, 11 (68,8 %) n'avaient pas de croissances bactériennes. Corynebacterium renale a été isolé chez 5 Il 2,5 %) bovins bien qu'il n'y ait pas eu de signe apparent de maladie ni de pyélonéphrite

Magnitude and risk factors associated with bovine dermatophilosis in Sabon-Gari, Kaduna state and Jos, Plateau state, Nigeria

Dermatophilosis is a contagious zoonotic skin disease affecting a variety of domestic and wild animals with grave economic consequences.  The status of bovine dermatophilosis and associated risk factors in Sabon-Gari, Kaduna State and Jos, Plateau State, Nigeria are yet to be fully determined. The aim of this study was to determine the prevalence of bovine dermatophilosis in Sabon-Gari and Jos. One thousand, nine hundred and twenty skin scab samples consisting of 1,530 from Sabon-Gari and 390 from Jos were obtained from cattle having cutaneous lesions including papules, exudative dermatitis with matting of the hair, cream colored, thickly crusted and scabby lesions suggestive of Dermatophilus infection. Smears were made from the underneath surface of each specimen on a clean glass slide,  air dried, heat fixed and Gram stained. The stained smears were examined microscopically for Gram-positive filamentous organism having both longitudinal and transverse division, typical of Dermatophilus congolensis. Further identification was done by isolating the causative agent in 5% de-fibrinated sheep blood agar. Data were analyzed using tables, percentages and Chi square test. P-values less than or equal  to 0.05 were considered significant. One hundred and forty-six (9.5 %) and 21 (5.4%) of the samples from Sabon-Gari and Jos respectively were positive for D. congolensis. The overall prevalence of bovine dermatophilosis in Sabon-Gari and Jos was 8.7% (167/1,920),  respectively. Breed, age, management practice and season were found to be significant risk factors associated with bovine  dermatophilosis. Methods for control of the disease in cattle as well as prevention of human exposure were highlighted. Keywords: Cattle, Dermatophilosis, Jos, Nigeria, Sabon-Gar

Vitamin E does not modify the insulin-induced memory impairment in mice during a novel object recognition task

There has been conflicting reports on the effects of insulin on the brain generally and on learning and memory in particular. Insulin was reported to cause negative effect on the brain through increasing oxidative stress. This study examined the sub-acute effect of insulin treatment on short-term working memory and the possible modulatory role of vitamin E.Twenty four mice were grouped into four (n=6) treated for seven days thus: Control group- water; Insulin group- insulin (10 I.U./kg/day); Insulin+vitamin E group- insulin (10 I.U./kg/day) + vitamin E (100 mg/kg); Vitamin E group- vitamin E (100 mg/kg). Histological examination of brain tissue was conducted following assessment of memory using novel object recognition task at the end of the treatments. Data wereanalysed using SPSS, where in p values < 0.05 were taken as significant. Time spent on the novel object by the animals in all the treatment groups was significantly reduced (p<0.05) when compared with the control. Novel object recognition was significantly higher (p<0.05) in the untreated controls when compared with all the treatment groups. Discrimination ratio was > 0.05 in all the groups. Histological findings were normal in the treatment and control groups.In conclusion, the findings of this study show that vitamin E does not modulate insulin-induced impairment in long-term visuo-spatial and short-term working memory. Sub-acute combined or separate treatments with insulin and vitamin E do not affect brain histology

Studies on effects of lactose on experimental <i>Trypanosoma vivax</i> infection in Zebu cattle. 2. Packed cell volume

The ability of intravenously administered lactose in normal saline to prevent a decline in packed cell volume (PCV) during experimental trypanosomosis was studied in Zebu cattle. During the lactose infusion period, the PCV was stable up to Day 5 post-infection (p.i.) in a lactose-infused group, compared to that in an uninfused group in which the PCV dropped significantly (P < 0.05) as shown by the values of cumulative percentage change. Furthermore the mean rate of change in PCV was significantly (P < 0.05) higher in the uninfused group relative to the lactose-infused group during the same period. While the PCV fell markedly in the lactose-infused group a day after lactose infusion was stopped (Day 13 p.i.), subsequent PCV values were significantly (P < 0.05) higher compared to those in the uninfused group, up to the end of experiment on Day 17 p.i. However the mean rates of change in PCV did not vary significantly (P > 0.05) between the groups during the period in which lactose infusion was stopped. The mean levels of parasitaemic waves and parasitaemia were higher, more prolonged and more frequent in the lactose-infused group. It was inferred that the lactose was able to prevent an early onset of anaemia in the Trypanosoma vivax-infected Zebu cattle

Mesenteric rent, ileal volvulus and ileocolic intussusception in a 3-year-old large-white dry sow: A postmortem report

This report presents a post-mortem (PM) finding of Large-White dry sow which died from complications associated with mesenteric rent, volvulus and intussusception. Other lesions included hydrothorax, ascites, and engorged mesenteric blood vessels, pale and enlarged liver. Helminthological and protozoological examinations of the intestinal samples were negative. Diagnosis of mesenteric rent, ileal volvulus and intussusception was reached. The diagnosis was attributable to the risk factors which include fight, excessive amounts of dry whey concentrate coupled with poor hygiene in the feeding and management system. Familiarizing swine farmers with the symptoms of bowel obstruction and provision of diagnostic facilities in commercial piggery farms will help in facilitating diagnosis and prompt action to prevent mortality and minimize economic loss. Keywords: Intussusception, Mesenteric rent, Sow, Volvulus, Whe

Cheilospirura hamulosa (Diesing, 1851) (Nematoda, Acuarioidea) in turkeys in Brazil: occurrence and pathology Cheilospirura hamulosa (Diesing, 1851) (Nematoda, Acuarioidea) em perus no Brasil: ocorrência e patologia

<abstract language="por">Relata-se o primeiro caso de infecção de perus, Meleagris gallopavo, por Cheilospirura hamulosa no Brasil, com base no achado de três espécimes fêmeas de C. hamulosa, inseridos na submucosa da moela de um peru, retirado de um lote de 15 aves, provenientes de criadouros domésticos no estado de Minas Gerais. A ocorrência foi de 6,7%. A ave parasitada não apresentava sinais clínicos. As lesões microscópicas da moela eram severas, caracterizando-se por intensos processos inflamatórios crônicos e difusos, com infiltrados mistos de granulócitos, estendendo-se à mucosa e às camadas musculares. Nessa área, foram observados fragmentos dos parasitos e perfuração da mucosa, com destruição das camadas musculares