Influence of extracellular calcium in the effects of dibekacin and diltiazem on indirectly elicited tetanic responses in the rat phrenic-hemidiaphragm preparation

1. Dibekacin (70 microM-3 mM) produced a decrease of peak tetanic tension in a concentration-dependent manner and this effect was dependent on extracellular calcium (0.3-2.5 mM Ca2+). Only minimal fade was observed and it was not related with extracellular calcium concentrations. 2. Diltiazem (30-300 microM) decreased peak tetanic tension and produced tetanic fade. Both effects were independent of extracellular calcium, although a significant potentiation was observed at 0.3 mM calcium. 3. It is concluded that tetanic parameters are related differently to extracellular calcium.     

Synthesis and anticonvulsant properties of some arylsuccinate methylpyridylimides

In reaction of alpha-phenyl, alpha-p-chlorophenyl and alpha-m-chlorophenylsuccinic acid with various aminopyridines, N-pyridyl-substituted succinimides (compounds 1-14) were obtained. These compounds were investigated for their CNS activity. Compounds 1, 2, 5, 6 and 7 displayed anticonvulsant properties in the maximum electroshock test. Compounds 5 and 6 were also active in the pentetrazole test.     

Pathogenesis and changes in the aetiology of arterio-venous fistulae

There has been a marked shift in the causes of arterio-venous fistulae. Gunshot and stab wounds used to be the most frequent cause but iatrogenic fistulae, especially those arising as a result of reconstructive skeletal operations or following diagnostic and therapeutic procedures, are now becoming increasingly common. If morphological vascular changes have not yet occurred and cardiac volume overloading has not led to permanent damage, a recently established arterio-venous fistula can be easily corrected by resection and oversewing of the artery and vein. The special cases of arterio-venous fistulae arising as a result of catheter procedures in the groin have to be identified in terms of cause and morphology in order to facilitate early surgical correction.     

Infection with human immunodeficiency virus and hepatitis viruses in Chinese drug addicts.

The prevalence of antibody against hepatitis C virus (anti-HCV) and five hepatitis B virus markers (HBVM) was measured in 176 Chinese drug addicts, of whom 23 were AIDS patients. Of 176 drug addicts, 147 were members of ethnic minorities while 29 were Han, the majority ethnic group. The total prevalence rates of anti-HCV and HBVM were 35.8% and 50.6% respectively, significantly different (P < 0.01). Anti-HCV and HBVM were together found in 22.7%. Similar prevalence rates were found among the different ethnic groups. Among the ethnic minorities, there was a significantly higher prevalence rate of anti-HCV in intravenous drug addicts (IVDA, 51.1%) than in oral drug addicts (20.3%). Furthermore, the prevalence of anti-HCV was significantly higher in needle-sharing abusers (60.4%) than in non-needle sharing ones (37.1%, P < 0.05). The prevalence of HBVM was also significantly higher in needle-sharing abusers (69.8%) than in non-needle sharing ones (34.3%). Prevalence of HBsAg was significantly higher in drug abusers with AIDS (47.8%) than in IVDA only (16.1%). The anti-HCV positive rates among ethnic minority people were: for the Yi people 69.2%, the Hui 55.6%, the Bai 53.9%, the Dai 26.8% and the Wa 23.1%. No obvious difference was identified for HBVM. The prevalence rates of HCV, HBV and HCV + HBV in IVDA showed no significant difference (P > 0.05) between the two regions. HIV, HCV and HBV infections may promote each other and be related to needle-sharing behaviour in drug abuse and to different subcultures and living habits.     

Protective Effects of Antioxidants Against Uraemia-Induced Lipid Peroxidation and Glutathione Depletion in Humans

Abstract: The effects of uraemias and antioxidant therapy for 40 days with vitamin A, vitamin C and vitamin E on blood and erythrocyte sulfhydryl (glutathione, GSH) content and on erythrocyte glutathione-S transferase (GST), glutathione reductase (GSR) and glutathione peroxidase activities were studied in six uraemic patients maintained on haemodialysis. In addition, the effect of antioxidant therapy on erythrocyte lipid peroxidation was determined, and erythrocyte haemoglobin content was measured. Uraemic patients in dialysis exhibited significant decreases in blood and erythrocyte GSH content as well as significant decreases in the activities of GST, GSR and GSH-peroxidase relative to control subjects. Furthermore, the uraemic patients had elevated erythrocyte malondialdehyde levels. Blood and erythrocyte GSH content from uraemic patients was significantly elevated after 20 days of antioxidant treatment and remained elevated thereafter throughout the remaining 20 days of the study (130% and 173%, respectively). Antioxidant therapy also produced significant increases in GSR and GSH-peroxidase activities after 20 days of treatment which remained relatively constant thereafter. No significant change in GST activity was observed. Erythrocyte malondialdehyde levels, as an index of oxidative tissue damage, exhibited a significant decrease (70%) in the patients after 40 days of antioxidant therapy. A gradual increase in erythrocyte haemoglobin content was observed following treatment of the uraemic subjects (45% at day 40). The results suggest that antioxidant therapy may protect against oxidative stress associated with uraemia.     

Partition coefficients of three new anticonvulsants

The partition coefficients of three homologous anticonvulsant phenylalkylamides [racemic alpha-hydroxy-alpha-ethyl-alpha-phenylacetamide (HEPA); beta-hydroxy-beta-ethyl-beta-phenylpropionamide (HEPP); and gamma-hydroxy-gamma-ethyl-gamma-phenylbutyramide (HEPB)] were determined by reversed-phase high-performance liquid chromatography (RP-HPLC). The system was calibrated with a series of simple amines and amides, using their published log P values. The log kw values (methanol:water, extrapolated to 100% water) were 1.260 for HEPA, 1.670 for HEPP, and 1.852 for HEPB. From these results, the partition coefficients (log P) were calculated by regression as 1.20, 1.83, and 2.11, respectively. The log P values were essentially equal to those calculated by the Leo-Hansch fragmental method. Since the potency of the three anticonvulsants is approximately the same in a variety of tests, no dependence on lipophilicity could be established.     

Ultrastructural study of a retinoma by intraocular fine-needle aspiration biopsy

The authors present the results of a transmission electron-microscopic study performed on a tissue sample obtained by an intraocular fine-needle aspiration biopsy in a case of retinoma. The ultrastructural study showed that the tumor was composed mainly of granular osmiophilic material which contained some tumor cells. These cells showed peculiar ultrastructural characteristics, which demonstrated their neural character, and appeared in different degenerative stages. Apparently, this is the first case in whom ultrastructural technique have been applied to study an intraocular tumor sample obtained by intraocular fine-needle aspiration biopsy, and the first case of retinoma studied by such a diagnostic approach.