Effect of vitamin B17 on experimentally induced colon cancer in adult male albino rat.

BACKGROUND: Colon cancer is considered to be the third most common cancer worldwide. At diagnosis of colon cancer, 3.7-11% developed bone metastasis. Diet based strategies are important for prevention and treatment of colon cancer. This study investigated the effect of vitamin B17 on a DMH induced rat model of colon cancer. MATERIALS AND METHODS: Eighty young adult male albino rats were divided into five groups: group I (control group), group II (vitamin B17), group III (colon cancer), group IV (protected) and group V (treated). Distal colon sections were prepared for light and scanning electron microscopic examination. Lumbar vertebrae specimens were prepared for light microscopic study. Morphometric and statistical analysis were done. RESULTS: In comparison with the control, both colon cancer and treated groups showed invasion of the colonic tissue by pleomorphic branching colonic glands of variable shapes and sizes lined with dysplastic elongated hyperchromatic nuclei with frequent mitotic figures or stratified multi-layered crowded nuclei with an extremely significant (p < 0.0001) reduction of goblet cell number when compared to the control together with major pathological bone changes were observed in colon cancer and the treated groups. CONCLUSIONS: While the protected group showed impressive improvement of all previously mentioned diameters.

Vitamin C attenuates the toxic effect of nutmeg on primary visual occipital cortex in rats.

BACKGROUND: Nutmeg is neurotoxic in rats and possibly neurotoxic also in hu- mans. The aim of this study is to investigate the effect of nutmeg on the primary visual occipital cortex of adult male rat and to evaluate the possible protective role of vitamin C. MATERIALS AND METHODS: Fifty Sprague-Dawley adults male rats were randomly divided into three main groups; control, nutmeg-treated (500 and 1000 mg/kg/ /day) and protected groups (nutmeg + vitamin C [500 mg/kg/day]). All rats were treated orally by gavage for 5 days per week for 6 weeks. At the end of the experiment, primary visual occipital cerebral cortex was subjected to histological, immunohistochemical and genetic analyses. RESULTS: Our results revealed toxic effects of nutmeg on the primary visual occipital cerebral cortex in adult male albino rat. This was indicated by histopathological alterations, including pyknotic nuclei surrounded with vacuolations by light micro- scopic studies and degenerations of organelles by electron microscopic studies. In addition, we detected an increase in immunoreactivity for GFAP and caspase-3 by immunohistochemical assessments. Apoptotic bands appeared in genetic studies. Co-administration of vitamin C ameliorated nutmeg-induced toxic alterations on the primary visual occipital cerebral cortex. CONCLUSIONS: Nutmeg administration caused histopathological and genetic changes in the primary visual occipital cerebral cortex in adult male albino rats. These changes were improved by co-administration of vitamin C.

Glucagon-like peptide-1 protects beta cells from cytokine-induced apoptosis and necrosis: role of protein kinase B.

AIMS/HYPOTHESIS: The gut hormone glucagon-like peptide-1 (GLP-1) decreases beta cell apoptosis in a protein kinase B (PKB)-dependent fashion, and increases islet cell mass and function in vivo. In contrast, cytokines induce beta cell apoptosis, leading to decreased islet mass and type 1 diabetes. In the present study we used rat INS-1E beta cells and primary rat islet cells to examine the potential role of PKB as a mediator of the effect of GLP-1 on cytokine-induced apoptosis. METHODS: Cell viability was determined by MTT assay, and apoptosis and necrosis by Hoechst 33342-propidium iodide staining. Immunoblot analysis was used to detect changes in protein expression, including active (phosphorylated) and total PKB, phosphorylated and total glycogen synthase kinase-3beta, activated caspase-3 and inducible nitric oxide synthase. Reactive oxygen species were determined by 1,7-dichlorofluorescein (DCF) analysis, and mutant forms of PKB were introduced into cells using adenoviral vectors. RESULTS: Incubation of INS-1E cells with cytokines (IL-1beta, TNF-alpha and interferon-gamma; 10-50 ng/ml) for 18 h significantly decreased cell viability (by 44%, p<0.001), cell proliferation (by 80%, p<0.001), and activation of PKB (by 67%, p<0.001). Pre-treatment with exendin-4 (10(-7) mol/l), a long-acting GLP-1 receptor agonist, partially protected the cells against cytokine-induced toxicity (p<0.01) in association with a reduction in cytokine-induced inhibition of PKB phosphorylation (p<0.05). Exendin-4 pre-treatment did not change cell proliferation. Cytokine treatment increased apoptosis (by 156%, p<0.05) and necrosis (from undetectable to 2.6% of cells). These increases were both reduced by pre-treatment with exendin-4 (p<0.05-0.01). Furthermore, cytokine-induced apoptosis and necrosis were significantly increased in cells infected with kinase-dead PKB (p<0.05), and the protective effect of exendin-4 on both parameters was fully abolished in these cells. Similar changes were observed in primary islet cells. In parallel with these changes, exendin-4 decreased the cytokine-induced activation of caspase-3 (by 46%, p<0.05), and decreased levels of inducible nitric oxide synthase (by 71%, p<0.05) and reactive oxygen species (by 27%, p<0.05). CONCLUSIONS/INTERPRETATION: The results of our study indicate that GLP-1 plays a protective role against cytokine-induced apoptosis and necrosis in beta cells through a PKB-dependent signalling pathway.

Vowel perception in prelingually deafened children with multichannel cochlear implants.

Vowel perception ability for 16 prelingually deafened children using Nucleus 22-channel cochlear implants was studied at 12, 24, and 36 months postimplantation. Information transmission analysis was used to evaluate the effectiveness of the implants in conveying the essential cues required for accurate vowel identification and whether the cues used varied with experience or device use. Individual vowel identification varied widely with mean scores significantly improving between 12 and 24 months but not between 24 and 36 months. Information transmission scores for all vowel features (fronting, height, duration, and diphthongization) increased dramatically between 12 and 36 months. Results indicated that vowel height and vowel fronting were the most salient features for the subject group. There were no differences in the pattern of confusions made across test sessions or across groups when divided into "poor" and "good" users. However, there was evidence that the "good" users made better use of higher frequency formant information than the "poor" users. The results of the present study add to the accumulation of evidence pointing to the great benefit that cochlear implantation can provide to prelingually deafened children. Overall performance for the vowel recognition test used in this study was quite high and analysis of the childrens' errors suggested that their cochlear implants were reasonably effective at conveying the most essential spectral information required for vowel discrimination.