Amplitudes of visually evoked potentials to patterned stimuli: age and sex comparisons

Electrophysiological age and sex differences in visual pattern responsivity were investigated. Pattern reversal evoked potentials (PREPs) and visual evoked potentials (VEPs) to patterned and unpatterned flashes were recorded from 20 normal subjects in each of 4 groups: young females and males aged 25-35 years and older females and males aged 55-70 years. PREP waves N70-P100 and P100-N150 from the older women were significantly larger than those from subjects in the other groups; mean amplitudes for the young females, young males and older males were not different. A similar effect, unusually large potentials for the older women, was obtained for VEPs, but only for VEPs elicited by patterned flashes and recorded from occipital scalp, i.e., an area overlying visual cortex which is sensitive to lines and edges. Our findings suggest that the visual system of older females is unusually responsive to patterned stimuli.     

Transfusion-related human immunodeficiency virus in patients with haemophilia in Johannesburg

Tests were carried out on 198 patients with inherited coagulation disorders attending haemophilia clinics of Johannesburg and Baragwanath Hospitals for the prevalence of antibodies to the human immunodeficiency virus (HIV). This cohort of patients has been treated with locally produced (South African) blood products from volunteer donors, except for a 15-month period in 1982-1984 when, owing to a shortage of locally produced material, an imported large donor-pool US factor VIII concentrate was used. Not all patients received this material. Of the haemophilia A patients who received the imported factor VIII concentrate, 85% were seropositive, while only 3% of the patients who received locally produced small donor-pool products were seropositive. No factor VIII-deficient patients have seroconverted while using small donor-pool products, since the introduction of routine screening of blood donations and strict exclusion criteria of donors. However, despite testing of blood products, 3 patients receiving locally produced factor IX concentrate (4,000 donors) seroconverted in 1988, having previously been HIV-negative. Factors influencing the choice of blood products to be used, especially in South Africa, are discussed.     

Localized bronchomalacia presenting as worsening asthma

A patient with longstanding mild asthma presented with a several month history of almost continuous wheezing. Pulmonary function tests suggested large airway variable intrathoracic obstruction. At bronchoscopy, she was found to have severe bronchomalacia limited to the left main bronchus. There was almost complete obstruction of that airway during forced expiration.     

Compartmentalized regulation of macrophage arachidonic acid metabolism

We show that downregulation of arachidonic acid (20:4) metabolism which occurs following i.p. injection of C. parvum can occur in a single, localized macrophage population, and is therefore unlikely to be mediated solely by a systemic factor.     

A survey of human T-cell leukaemia virus type I antibodies in patients with malignant disease in the Witwatersrand area

The prevalence of antibodies to human T-cell leukaemia virus type I in Africa ranges from 2% to 21% according to the geographical area surveyed. Most studies suggest that the background infection rate in children is low. In paediatric patients with malignant disease in the Witwatersrand area the prevalence is low (1%), whereas a seemingly high rate is found in healthy black children from a restricted rural area (7%). Further, the antibody prevalence in adult whites with lymphoproliferative disease is low (1%) compared with that in blacks with malignant disease (6%). There also appears to be a higher prevalence of positive results in black women (7%) than in black men (4%).     

HOSPITAL PRIVILEGES

This article describes the process of obtaining hospital privileges and the legal and practical ways of challenging a denial of privileges to a certified nurse midwife. In general, the political and practical means have been more effective than other challenges; but in the future, threats of legal action may be more common and more effective.