The role of an aggressive factor in peptic ulcer disease (pud)

The stomach is the expanded part of the digestive tract between the esophagus and the small intestine. It acts as a reservoir and has chief function in enzymatic digestion. Several types of glands provide different types of secretions in the alimentary tract most of which act as lubricant and to protect the stomach mucosa from excoriation.The pathophysiology of peptic ulcer disease (PUD) is often described as an imbalance between aggressive factors and mucosal protective mechanisms. Helicobacter pylori, a gram-negative organism that has been identified as a potential causative agent in the pathogenesis of peptic ulcer disease, which is diagnosed by invasive or non-invasivemethods. Three classes of drugs have been shown to have a direct effect on Helicobacter pylori: antibiotics, bismuth salts, and proton pump inhibitors. Because Helicobacter pylori is difficult to eradicate, most treatment regimes combine agents from two or even all three of these cases. In all of them, patients with active peptic disease shouldalso receive a total of 6 weeks of acid suppression with an H2-receptor antagonist. The discovery of Helicobacter pylori as a gastrointestinal pathogen has had a profound effect on current concepts of the pathogenesis and treatment of peptic ulcer disease. Key words: peptic ulcer disease, Helicobacter pylori, H2-receptor antagonist, pathophysiolog

Preliminary mortality and eclosion: dose-determining factors of aqueous extract of Hibiscus sabdariffa in Drosophila melanogaster

Background: This study investigated the toxicity of Hibiscus sabdariffa extract using simple end point assays (mortality and eclosion assay) in Drosophila melanogaster (Harwich strain) flies. Methods: The study was carried out in two phases (phases I and II) and in an array of concentrations of 10, 20, 30, 40 and 50 mg/ml in phase I; 100, 250, 500, 750 and 1000mg/ml in phase II for the period of 168 hours. Thirty (30) 4-day old flies were used in each concentration and mortality was recorded every 24 hours for the period of the study. Eclosion was scored after emergence of the adult flies. Results: There was no significant difference (p<0.05) in mortality and eclosion between the (experimental) concentrations and the control in the first phase of this study, indicating low/zero toxicity to the parent and the emerged flies. However, higher concentrations of 250 through 1000mg/ml of the second phase showed significant (p<0.05) increased mortality and decreased eclosion scores, indicating high acute toxicity to D. melanogaster. Conclusion: The LC50 of Hibiscus sabdariffa after 168 hours was 427.1mg/10g diet in Drosophila melanogaster and much eclosion was recorded at doses between 10 - 100mg/10g diet as compared with doses between 250 - 1000mg/10g diet. Eclosion can be considered a factor in the determination of LC50 in Drosophila melanogaster. Keywords: Drosophila melanogaster, Hibiscus sabdariffa, mortality, eclosion, concentratio

Effects of shisha smoke inhalation on some long-term memory forms in adult male mice

Background: Shisha is a flavoured tobacco designed to be smoked in a water-pipe, but it effects on long-term memory has not been fully explored. This study was undertaken to evaluate the effect of Shisha smoke inhalation on some long-term memory models in adult male BALB/c mice. Methods: Twenty male mice were divided into 4 groups of five mice each. Group I (control): fresh air; group II: exposed to bonged Shisha; group III: exposed to unbonged Shisha; group IV: exposed to activated charcoal smoke only. Each group was exposed for thirty minutes daily for seven weeks. Long-term memory was assessed using elevated plus maze (EPM), novel object recognition test (NORT) and Barnes maze (BM). Results: There was statistically significant decrease (P<0.05) in novel object recognition in bonged Shisha group when compared with the control. There was statistically significant increase (P<0.05) in spatial learning and memory in bonged Shisha group when compared with control. There was statistically significant decrease (P<0.05) in acetylcholinesterase activity in bonged Shisha group when compared with control, but there was no statistically significant difference in anxiety related spatial memory in elevated plus maze when compared with the control. There was also increased in necrosis of hippocampal cells in bonged Shisha group and slight necrosis in unbonged and activated charcoal smoke when compared to control mice. Conclusion: The outcomes of this study suggest that bonged Shisha smoke is neurotoxic to the brain because of combined effect of various toxicants emanating from different Shisha smoke constituents used in the set-up Keywords: Shisha, Memory, Hippocampus, Acetylcholinesteras

Sub-acute insulin therapy does not affect long-term visiospatial learning and memory in mice assessed using Barnes maze

Insulin is a common hypoglycaemic agent used to treat diabetes, but it has also been reported to exert other effects on the body including modulation cognition. Reported findings on insulin effect on learning and memory are scanty and often conflicting. This study was aimed at evaluating the effect of sub-acute insulin therapy on visio-spatial learning and memory using Barnes maze. Twelve young mice of both sexes, weighing between 20 – 22 g, were divided into control and insulin-treated groups (n = 6). They were administered subcutaneously with deionized water (control) or insulin (10 I.U./kg/day) for seven days. During the last three days of treatments, the mice were subjected to two-day training and one-day probe trial of Barnes maze. Number of primary head searches on day 2 was reduced compared to day 1 for both the insulin-treated (4.17 ± 0.8 s and 11.45 ± 1.9 s) and control (10.0 ± 3.2 s and 19.95 ± 4.5 s) groups (P < 0.05), but the values obtained in the two groups did not differ (P > 0.05). Similarly, there was no difference between the insulin-treated and control groups in latency to locate the escape hole, time spent and number of head searches per quadrant. It was concluded that sub-acute insulin therapy did not affect long-term visio-spatial learning and memory in mice.Keywords: insulin, visio-spatial learning and memory, long-term memory, Barnes maze, mic

Outcome of sub-acute insulin administration on long-term visuo-spatial and short-term working memory in mice

Background: In the past, insulin was considered a peripheral hormone, unable to affect the central nervous system. Now, it is well established that insulin occurs in the brain where it exerts regulatory and trophic effects. This study was undertaken to determine the effect of sub-acute insulin administration on long-term visuo-spatial and short-term working memory.Methods: Twenty four mice, weighing between 18 – 22 g, were used. Two groups of six mice each were used during elevated plus maze and Y-maze, to determine long-term visuo-spatial and short-term spatial working memory, respectively. Control group received deionized water, while insulin group received insulin at 10 I.U./kg/day, subcutaneously.Results: In the elevated plus maze, acquisition and retention latencies were the same (P > 0.05) when compared between the groups. In the Y-maze test, number of entries into arms was similar (P > 0.05) within and between groups. Time spent in the novel arm by mice in the insulin (103.83 ±7.4 seconds) and control (108.00 ± 13.6 seconds) groups was higher (P < 0.05) when compared to time spent in arm A (68.33 ± 10.0 and 74.50 ± 5.6 seconds, respectively) and B (59.17 ± 9.5 and 69.67 ± 10.7, respectively). Number of triads and percent alternations were also the same (P > 0.05) when compared between the groups.Conclusion: It was concluded, that sub-acute insulin administration did not affect long-term visuo-spatial memory and short-term working memory in mice.Keywords: insulin, long-term visuo-spatial memory, short-term spatial memory, working memory, sub-acute treatmen

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

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