Electrophysiological differences in cortical excitability in different forms of dementia: A transcranial magnetic stimulation and laboratory biomarkers study.

BACKGROUND: The aim of the present study was to identify neurophysiologic markers to differentiate between Alzheimer dementia (AD), Vascular dementia (VaD), and Parkinson's disease dementia (PDD), and to examine their relationship to levels of transforming growth factor ß1 (TGFß1). METHODS: The study included 15 patients with each type of dementia (AD, VaD, PDD) and 25 control subjects. Dementia patients were diagnosed according to the DiagnosticandStatisticalManualofMentalDisorders4thedition-revised(DSM-IV-R). Modified Mini Mental State Examination (MMMSE), motor cortex excitability including resting and active motor thresholds (rMT, aMT), input-output (I/O) curve, contralateral and ipsilateral silent periods (cSP, iSP), short-interval intracortical inhibition (SICI) at 1,2 and 4ms, and serum levels of TGFß1 were examined. RESULTS: There were no significant differences between groups with regards to age, sex, education or socioeconomic level. There was significant neuronal hyperexcitability in the form of reduced rMT and aMT and a shallower I/O curve in all three groups of dementia compared with the control group. The durations of cSP and iSP were longer in AD and PDD groups compared with the control group, whereas there were no significant differences in VaD. SICI was less effective in the three dementia groups than in the control group at intervals of 4ms. Serum levels of TGFß1 were significantly elevated in all dementia groups in comparison with the control group. There was a significant negative correlation between serum level of TGFß1 and cSP, iSP, and SICI across all patients and a significant negative correlation between serum level of TGFß1 and iSP duration in AD. CONCLUSION: Although motor thresholds were reduced in all patients, measures of SICI, cSP and iSP could distinguish between dementia groups. Serum level of TGFß1 negatively correlated with iSP specifically in the AD group. This suggests that levels of TGFß1 may relate to GABAergic dysfunction in dementia.

Impact of Ginkgo biloba extract and magnetized water on the survival rate and functional capabilities of pancreatic ß-cells in type 2 diabetic rat model.

INTRODUCTION: Type 2 diabetes (T2D) is a widely distributed disease that affects large population worldwide. This study aimed to verify the role of Ginkgo biloba (GB) extract and magnetized water (MW) on the survival rate and functional capabilities of pancreatic ß-cells in type 2 diabetic rats. MATERIALS AND METHODS: T2D was induced by feeding the rats on a high-fat diet (20% fat, 45% carbohydrate, 22% protein) for eight weeks followed by intra-peritoneal injection of a single low dose of streptozotocin (25mg/Kg). Forty rats were randomly assigned to four groups (n=10 rats) as follows: non treated control and three diabetic groups. One diabetic group served as a positive control (diabetic), while the other two groups were orally administered with water extract of GB leaves (0.11 g/kg/day) and MW (600 gauss) for four weeks, respectively. RESULTS: The ß-cell mass and insulin expression in these cells increased markedly after both treatments, particularly in GB treated group. In addition, the immune-expression of the two antioxidant enzymes; glutathione and superoxide dismutase 2 (SOD2) in the pancreatic tissue demonstrated a down-regulation in GB and MW treated groups as compared with the diabetic group. CONCLUSION: A four-week treatment of GB and MW protected pancreatic ß-cell cells and improved their insulin expression and antioxidant status in type 2 diabetic rats.

The protective role of folic acid against testicular dysfunction in lead-intoxicated rat model.

There is an increasing concern over male reproductive toxicity caused by lead exposure. Folic acid (FA) is supposed to be a promising therapeutic strategy against lead toxicity. Therefore, the aim of this experimental study was to shed light on the potential protective role of FA on lead-induced testicular dysfunction in rats and its possible underlying mechanistic pathways. Rats (n = 24) were divided into four groups: Control, FA, Lead, and FA+Lead group. After 4 weeks, lead intoxication resulted in a marked reduction in the relative testicular weight and the serum level of testosterone, an impairment in the characters of semen analysis, and an increased content of lead, malondialdehyde and both interleukin-6 and -10 and a decreased antioxidant enzyme levels in the testicular tissue homogenate. Furthermore, marked degenerative histological changes and an increased expression of NF-κB were also noticed in the testicular tissue of Lead group. Supplementation of FA in association with lead considerably alleviated these adverse outcome responses most probably owing to its cytoprotective ability as emerged from combating the oxidative stress and inflammatory reactions. We concluded that FA could act as a highly effective fighting approach against lead-associated testicular toxicity.

Neuroprotective effects of melatonin administration against chronic immobilization stress in rats.

Chronic stress can impair brain functions and play a well-known role in the development of stress-related disorders such as anxiety. Melatonin (Mel) is a neurohormone which regulate several physiological processes including mood and behavior. This experimental study was designed to evaluate the effect of Mel on chronic immobilization stress (CIS) for 6 weeks in rats and to elucidate its possible underlying mechanisms. Twenty-eight adult male Wistar albino rats were divided into four equal groups: the control group, the Mel-treated group which was injected daily with Mel (10 mg/kg/day; IP) for 6 weeks, the stressed group which was subjected to CIS protocol daily for 6 weeks, and the Mel-treated stressed group which was injected with Mel and concurrently exposed to CIS protocol for 6 weeks. The Mel-treated stressed group showed reduction of both relative adrenal weight and the serum corticosterone levels, suppression of the anxiety-like behavior, increased levels of serotonin, noradrenaline and oxytocin in the frontal cortex, and improved histopathological structure and decreased chromogranin A (CgA) protein expression in the frontal cortex when compared with the chronically stressed group. We concluded that Mel is anxiolytic and this effect was mediated in part by its ability to increase the central release of oxytocin and monoamines and to downregulate CgA protein expression in the frontal cortex.