Hypoglycaemic activity of dioscoretine from tubers of Dioscorea dumetorum in normal and alloxan diabetic rabbits

Dioscoretine isolated from the aqueous fraction of the methanol extract of Dioscorea dumetorum tubers when administered intra-peritoneally to normal and alloxan diabetic rabbits produces significant hypoglycaemic effects at a dose of 20 mg/kg. The fasting blood sugar in normoglycaemic rabbits was reduced from 112 mg/100 ml to 55 mg/100 ml after 4 hours. In alloxan diabetic rabbits, the blood sugar was lowered from 520 mg/100 ml to 286 mg/100 ml at the same time interval. The aqueous fraction of the methanol extract produced comparable effects at 100 mg/kg. The chloroform fraction of the same extract raised the fasting blood sugar of normal rabbits to 196 mg/100 ml after 6 h. The acute toxicity studies gave LD50 values of 1.4 g/kg for the aqueous fraction and 0.58 g/kg for dioscoretine when tested on mice. The hypoglycaemic effects were compared to those of tolbutamide.     

Sigmoidin F, a new prenylated flavonoid from Erythrina sigmoidea

Sigmoidin F, a new prenylated flavanone, as well as abyssinone IV and 5,7,4'-trihydroxy-3'-methoxy-5'-(1"-prenyl) flavonone have been isolated from the stem and bark of Erythrina sigmoidea. The structure of 1 has been confirmed by a combination of 1H-nmr and other spectroscopic techniques.     

Diagnosis of canine coronavirus infection using nested-PCR

The results of polymerase chain reaction (PCR) and nested polymerase chain reaction (n-PCR) assays for the diagnosis of canine coronavirus (CCV) infection, and the comparison with other diagnostic techniques, such as electron microscopy (EM) and virus isolation using A-72 cell line are reported. The study was carried out on 71 faecal samples of pups with enteritis. Of 71 samples examined 14 were positive in PCR, whereas 30 samples resulted positive in the n-PCR assay. CCV was detected by EM examination in only four out of 45 samples, and by virus isolation in three out of 30 samples n-PCR positive.     

Evaluation of the natural immunity in pups inoculated with a modified-live canine parvovirus type 2b (CPV-2b) strain

Three pups 2-4 months old were vaccinated subcutaneously with the modified live canine parvovirus, CPV-2b/29-97 strain. During an observation period of two weeks pups remained clinically health, exhibiting a vigorous post-vaccinal active serological response (haemoagglutinating inhibiting antibody titers for CPV-2 ranging from 1:2560 to 1:5120 at 21 days post inoculation). Phagocytosis and killing of Candida albicans exerted by polymorphonuclear cells and monocytes did not undergo significant modifications 3-6 days post vaccination up to 30 days. Antibacterial activity mediated by peripheral blood lymphocytes (Salmonella typhi was used as a target) was slightly, but not significantly decreased 3 days post vaccination.

Conclusively, in pups the CPV type 2b vaccine seems to be safe as far as natural immune responses are concerned, while its immunogenicity is preserved.     

Effects of indirubin and isatin on cell viability,mutagenicity, genotoxicity and BAX/ERCC1 gene expression

Context: Indigofera suffruticosa Miller (Fabaceae) and I. truxillensis Kunth produce compounds, such as isatin (ISA) and indirubin (IRN), which possess antitumour properties. Their effects in mammalian cells are still not very well understood.

Objective: We evaluated the activities of ISA and/or IRN on cell viability and apoptosis in vitro, their genotoxic potentials in vitro and in vivo, and the IRN- and ISA-induced expression of ERCC1 or BAX genes.

Materials and methods: HeLa and/or CHO-K1 cell lines were tested (3 or 24?h) in the MTT, Trypan blue exclusion, acridine orange/ethidium bromide, cytokinesis-blocked micronucleus (CBMN) and comet (36, 24 and 72?h) tests after treatment with IRN (0.1 to 200?μM) or ISA (0.5 to 50?μM). Gene expression was measured by RT-qPCR in HeLa cells. Swiss albino mice received IRN (3, 4 or 24?h) by gavage (50, 100 and 150?mg/kg determined from the LD₅₀ – 1?g/kg b.w.) and submitted to comet assay in vivo.

Results: IRN reduced the viability of CHO-K1 (24?h; 5 to 200?μM) and HeLa cells (10 to 200?μM), and was antiproliferative in the CBMN test (CHO-K1: 0.5 to 10?μM; HeLa: 5 and 10?μM). The drug did not induce apoptosis, micronucleus neither altered gene expression. IRN and ISA were genotoxic for HeLa cells (3 and 24?h) at all doses tested. IRN (100 and 150?mg/kg) also induced genotoxicity in vivo (4?h).

Conclusion: IRN and ISA have properties that make them candidates as chemotherapeutics for further pharmacological investigations.     

Emotional working memory during sustained wakefulness

In the present study we investigated whether one night of sleep deprivation can affect working memory (WM) performance with emotional stimuli. Twenty‐five subjects were tested after one night of sleep deprivation and after one night of undisturbed sleep at home. As a second aim of the study, to evaluate the cumulative effects of sleep loss and of time‐of‐day changes on emotional WM ability, the subjects were tested every 4 h, from 22:00 to 10:00 hours, in four testing sessions during the sleep deprivation period (deprivation sessions: D1, D2, D3 and D4). Subjects performed the following test battery: Psychomotor Vigilance Task, 0‐back task, 2‐back task and an ‘emotional 2‐back task’ with neutral, positive and negative emotional pictures selected from the International Affective Picture System. Results showed lower accuracy in the emotional WM task when the participants were sleep‐deprived relative to when they had slept, suggesting the crucial role of sleep for preserving WM ability. In addition, the accuracy for the negative pictures remains stable during the sessions performed from 22:00 to 06:00 hours (D1, D2 and D3), while it drops at the D4 session, when the participants had accumulated the longest sleep debt. It is suggested that, during sleep loss, attentional and WM mechanisms may be sustained by the higher arousing characteristics of the emotional (negative) stimuli.     

Validity of the Italian Version of the Pittsburgh Sleep Quality Index (PSQI)

The aim of this study is to validate the Italian version of the Pittsburgh Sleep Quality Index (PSQI), comparing five different groups of individuals (healthy young and elderly, sleep apnoea syndrome patients, depressed patients, individuals with dementia) by both questionnaire scores and polysomnographic measures. Fifty individuals (10 for each group) participated in the study. Each of them filled in the PSQI and slept for two consecutive nights in the sleep laboratory. The PSQI showed an overall reliability coefficient (Cronbach’s α) of 0.835, indicating a high degree of internal consistency. The mean PSQI global score showed significant differences between groups, with an impaired overall quality of sleep in patients’ groups with respect to both the healthy groups. Results also indicated that the best cut-off score (differentiating “good” from “bad” sleepers) is 5. Pittsburgh Sleep Quality Index is a useful, valid and reliable tool for the assessment of sleep quality, with an overall efficiency comparable to the mother language version and differentiate “good” from “bad” sleepers. The Italian version of the questionnaire provides a good and reliable differentiation between normal and pathological groups, with higher scores reported by people characterized by impaired objectively evaluated sleep quality.     

Motor-evoked potentials in amyotrophic lateral sclerosis: potential implications in detecting subclinical UMN involvement in lower motor neuron phenotype

Journal of Neurology - In amyotrophic lateral sclerosis (ALS), the involvement of lower motor neuron is well defined by electromyography, whereas a reliable marker of upper motor neuron (UMN)...