Prevalence of hepatitis B virus (HBV) markers and human immunodeficiency virus (HIV) in employees of a blood transfusion centre

Blood bank staff, 8 out of 25 (32%) have been exposed to hepatitis B virus (HBV) and the prevalence of HBV markers in blood bank employees handling high risk subjects show hepatitis B surface antigen (n = 1), hepatitis B surface antibody (n = 7), hepatitis B core antibody (n = 6) and combined hepatitis B surface antibody and hepatitis B core antibody (n = 6) seropositivity but all are negative to human immunodeficiency virus (HIV). Serum alanine aminotransferase was raised in the employees than normal subjects and it is suggestive of sub-clinical hepatitis. The employees of blood bank should be trained for proper handling of test materials and must be periodically monitored for HBV and HIV. Immunisation for HBV is mandatory only for the employees of transfusion centre which handles high risk subjects.     

Regionally selective effects of NMDA receptor antagonists against ischemic brain damage in the gerbil

This study compared the ability of three N-methyl-D-aspartate (NMDA) receptor antagonists to prevent neuronal degeneration in an animal model of global cerebral ischemia. The model employed is characterized by damage to the striatum, hippocampus, and neocortex. Antagonists were administered to gerbils either before or after a 5-min bilateral carotid occlusion. The intraischemic rectal temperature was either maintained at 36-37 degrees C or allowed to fall passively to 28-32 degrees C. Antagonists and doses tested were 1 and 10 mg/kg of MK-801 (pre- or postischemia), 30 mg/kg of CGS 19755 preischemia, four 25 mg/kg doses of CGS 19755 administered between 0.5 and 6.5 h postischemia, and 40 mg/kg of MDL 27,266 (pre- or postischemia). All three NMDA receptor antagonists exhibited some degree of neuroprotective activity when the carotid occlusion was performed under normothermic conditions. Most of the treatments with antagonist markedly reduced striatal damage. CA1 hippocampal and neocortical pyramidal cells were spared by only three of the treatments, however, and the extent of neuroprotection varied widely from case to case. Toxic doses of antagonist were required to protect CA1 pyramidal cells from ischemic damage. Ischemic damage to hippocampal areas CA2-CA3a and CA4 appeared to be resistant to all of these treatments. Most CA1 pyramidal cells that were protected from degeneration by an NMDA receptor antagonist were histologically abnormal. The neuroprotective effects of MK-801 and intraischemic hypothermia appeared to be additive. MK-801 (10 mg/kg) consistently reduced the postischemic brain temperature, but only the magnitude of hypothermia produced soon after reperfusion correlated with its neuroprotective action. These results suggest that NMDA receptor antagonists are relatively poor neuroprotective agents against a moderately severe ischemic insult.     

Stereoscopic evoked responses to crossed and uncrossed disparity accompanying simulated refractive error.

Evoked potentials were recorded to the occurrence of a disparate stimulus in dynamic random dot stereograms. Seven adult males, all of whom had vision which was normal or corrected to normal, participated in the experiment. Subjects viewed 100 ms duration stimuli which embodied 30 arc min of either crossed or uncrossed disparity under four conditions of spherical overcorrection: -0.25, +1.0, +2.0, +3.0 dioptres. The first condition, essentially normal refraction, yielded reliable behavioural reports of the stimulus and clear evoked potentials to both crossed and uncrossed disparity. With increasing overcorrection the behavioural reports became less reliable, and the evoked potentials were degraded for both conditions of disparity. The responses to the crossed disparity condition, however, showed significantly less degradation in both behavioural and electrophysiological measures. The implications of this finding may be that there are separate cortical subsystems for the processing of crossed and uncrossed disparity and that the former is more robust under non-ideal viewing conditions.     

Renal transplantation performed across a positive crossmatch: A single centre experience

The importance of certain positive crossmatches (CM⁺) in kidney transplantation remains controversial. Fifty consecutive kidney transplants were performed across a CM⁺ between Jan. 1990 – April 1994. In 19 cases there was an isolated B-cell CM⁺ (Group I), in 24 an historic T-cell IgM CM⁺ (Group II) and in 7 an historic T-cell IgG CM⁺ (Group III). Comparing groups I:II:III: early acute rejection affected 32%, 42%, 57% of grafts; mean serum creatinine at 3 months was 166, 150, 229 umol/l (p<0.05); 1 yr graft survival was 95 per cent, 96 per cent, 71 per cent (p=0.09). In group III both graft losses were in the setting of an additional current B-cell CM⁺. Conclusions: Transplantation performed in either the presence of an isolated B-cell CM⁺ or in the presence of an historic T-cell IgM CM⁺ was associated with acceptable outcomes at 1 yr. An historic T-cell IgG CM⁺ was confirmed as a contraindication to transplantation in most circumstances, especially when coupled with a current B-cell CM⁺.     

Combination of a thiazide, a vasodilator and reserpine compared with methyldopa plus hydrochlorothiazide in the treatment of hypertension in Zimbabwe

Brinerdin (Sandoz), a combination of a diuretic (clopamide 5 mg), a vasodilator (dihydro-ergocristine 0.5 mg) and reserpine (0.1 mg) (CDR) was compared with methyldopa (MD) plus hydrochlorothiazide (HCT) for antihypertensive effect, adverse reactions, compliance and patient preference in an open cross-over trial. Eighteen patients completed both arms of the trial and 5 patients who completed the CDR arm were withdrawn while on the MD arm because of adverse effects in 4 and poor control in 1. On HCT 50 mg daily the mean baseline systolic blood pressure was 163.9 +/- 16.3 mmHg and the diastolic blood pressure was 105.9 +/- 6.7 mmHg. On CDR these were reduced to systolic blood pressure 140.3 +/- 15.1 mmHg and diastolic blood pressure 87.8 +/- 9.3 mmHg. On MD + HCT the systolic blood pressure was reduced to 138.5 +/- 16.9 mmHg and the diastolic blood pressure to 88.9 +/- 10.3 mmHg. The differences between the two treatment periods in systolic blood pressure (1.8 mmHg; 95% confidence interval (CI) - 4.1 + 7.7 mmHg) and diastolic blood pressure (1.1 mmHg; 95% CI - 4.6 + 2.4 mmHg) were not significant with P values of 0.6 and 0.7 respectively. Compliance was 98.2% for CDR and 94.7% for MD + HCT (P = 0.02). Unusual sleepiness occurred more frequently in the MD arm (P less than 0.01). Thirteen patients chose to continue on CDR, 2 on MD + HCT and 3 had no preference (P = 0.005). CDR is similar in antihypertensive effect to MD + HCT but is better tolerated with fewer withdrawals, fewer adverse effects, better compliance and has more patients electing to continue taking it.