Isolation of African swine fever virus from ticks of the Ornithodoros moubata complex (Ixodoidea: Argasidae) collected within the African swine fever enzootic area of Malawi

Ticks of the Ornithodoros moubata complex were collected from domestic pig sties and dwelling houses, and from a warthog habitat, and tested for the presence of African swine fever (ASF) virus. Collections were made in 9 of the 24 districts of Malawi, these being primarily the districts in which O. moubata is most numerous. ASF virus was isolated from ticks collected in both domestic pig sties and houses in certain villages in Mchinji district where ASF outbreaks had recently occurred. Mchinji district is in the centre of a large ASF enzootic area which stretches into other districts of Malawi and also into Zambia and Mozambique. The high titre of virus in some of the ticks demonstrates that O. moubata can act as a virus reservoir and potential vector of disease in the field situation in Malawi.     

Juvenile hypocalcemia provokes persistent electroencephalographic change in renally compromised rats

In view of the putative involvement of calcium in uremic encephalopathy and the critical importance of this element in juvenile development, we examined the effect of temporary restriction of dietary calcium intake on serum chemistry and the quantitative electroencephalogram (Q.EEG) in unilaterally 3/4 nephrectomized juvenile male Sprague-Dawley rats. Animals were renally infarcted at 22-26 days of age (50-74 g) and placed on one of two isocaloric dietary regimens: powdered normal rat diet (ND, n = 25) or low calcium diet (LCD, n = 8) for 30 days. At this time, ND animals showed normal serum chemistries, whereas LCD rats were hypocalcemic and azotemic with significantly elevated blood urea nitrogen (BUN) and serum creatinine concentrations and reduced renal creatinine clearance values. All animals thereafter received ND for 25-34 further days, during which time chronic Q.EEG electrodes were implanted. At the end of the common ND feeding period, serum chemistry values were equal and normal in both groups. The average theta/alpha ratio (TAR) of the overnight Q.EEG was assessed for 3 days. We found that the TAR of previously LCD animals was significantly elevated compared with ND rats. This indicates an encephalopathic slowing of the background rhythm of these animals. We conclude that, following restoration of a transient uremic and hypocalcemic episode induced by LCD feeding, the Q.EEG background frequency of juvenile renally impaired rats was abnormally slow after 30 days of ND feeding.     

Nutrient intake in insulin-dependent diabetic patients with incipient nephropathy

The onset of diabetic nephropathy is characterized by subclinical elevation of urinary albumin excretion, so-called 'microalbuminuria' (M). Dietary assessments were carried out in 15 insulin-dependent diabetic patients with persistent M and an equal number with persistently normal albumin excretion. The groups were matched for sex, age, duration of diabetes, body mass index, insulin dose and glycosylated haemoglobin; there were no significant differences in systemic blood pressure, glomerular filtration rate, blood glucose and serum albumin concentrations between the groups; retinopathy was significantly more frequent in patients with M. Diabetics with persistent M were found to consume a significantly larger amount of fat (expressed as grams and percentage of total energy) and a significantly smaller percentage of total energy as carbohydrate than patients with normal albumin excretion; total dietary energy was larger in those with persistent M, but the difference was not significant. No significant differences were found in protein and fibre intakes between the groups. Our findings suggest that an excess in the dietary consumption of fat relative to carbohydrate might play an important role in the pathogenesis of early nephropathy in insulin-dependent diabetes mellitus. We emphasize the importance of careful attention to nutrient intake in the prevention and treatment of diabetic complications.     

Tear mucus crystallization in children with cystic fibrosis

Cystic fibrosis is characterized by an abnormally high electrolyte concentration in exocrine secretions. The authors performed the tear mucus ferning test in 26 eyes of children with cystic fibrosis and compared the results to those in an equal number of age-matched normals. The results suggest that the increased electrolyte concentration could be responsible for the increased hyperviscosity of mucus. The tear mucus ferning test appears to be a suitable diagnostic test for the assessment of cystic fibrosis.