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Biomedical subjects

B Bjorvatn

Publications and source records attributed to B Bjorvatn.

117 records · Page 7Linked to original sources
PubMedDate not supplied

Quantitation of endotoxin in blood from patients with meningococcal disease using a limulus lysate test in combination with chromogenic substrate.

The levels of endotoxin in blood were determined using the Limulus lysate test in combination with a chromogenic substrate. Plasma was analyzed from four patients with fatal meningococcal septicaemia and from one patient who survived meningococcal meningitis. All septicaemia patients showed high levels of endotoxin in their blood during the early stage of their disease. In two of these patients, blood samples collected at intervals of two days revealed a gradual disappearance of measurable endotoxin from the circulation. The patient with meningitis had no clinical signs of circulatory deficiency or coagulopathy and was consistently negative for endotoxin using this test procedure. Pretreating the plasma with heat and alkali and combining the Limulus lysate test with a chromogenic substrate seem to provide a sensible method for the detection and quantitation of endotoxin in blood.

Adolescent↗
PubMedDate not supplied

Zymodeme conversion of isolates of Entamoeba histolytica.

A non-cloned and a cloned isolate of non-pathogenic (zymodeme I) Entamoeba histolytica derived from homosexual males were incubated in Diamonds' TP-S-1 medium in the presence of Crithidia for 52 d. A single addition of Escherichia coli irradiated at 1000 Gy rendered the culture axenic. Analysis of zymodeme patterns established that both isolates had transformed to zymodeme II. The re-establishment of cultures in the presence of microflora from the original cultures resulted in a return to zymodeme I, whereas incubation with microflora from an amoebic isolate exhibiting a zymodeme II pattern maintained the pathogenic pattern.

Animals↗
PubMedDate not supplied

Population growth, fertility, mortality and migration in drought prone areas in Ethiopia.

To assess the population dynamics of drought-prone communities, we investigated 605 households in the pastoralist Boran community of Dubluk and in the agricultural community of Elka, both located in southern Ethiopia. The age and sex composition of the population as well as records of births, deaths and patterns of migration were observed for 2 consecutive years. Repeated surveys of the same households revealed much higher rates for deaths and births than did cross-sectional surveys with a one-year recall period. Indirect mortality estimates showed that the under 5 years mortality rates (per 1000 births) were 135 in Dubluk and 219 in Elka. Highest crude death rates were observed in Elka during periods of meningitis and malaria epidemics. During the period of observation, death rates fluctuated to a greater extent than birth rates. Both communities had very high rates of natural increase: in Dubluk 39.0/1000 and in Elka 37.1/1000. In Dubluk, this rate was far higher than any previously recorded and may have indicated that fertility regulating mechanisms, traditionally inherent in the pastoralist social organization, had become weaker as part of cultural changes. Dubluk represented a semi-nomadic society with a moderately high mobility pattern. Peak periods of migration coincided with times of food scarcity in Elka.

Adolescent↗
PubMedDate not supplied

Chemotherapy of Entamoeba histolytica: studies in vitro with bacitracin and its zinc salt.

Twenty-one Entamoeba histolytica isolates from a range of geographical locations and representing 3 different zymodemes were tested under xenic anaerobic conditions for their sensitivities to bacitracin and bactracin zinc. Isolates were over 13 times more sensitive to bacitracin zinc than to bacitracin. Our results indicate that bacitracin zinc may form the basis of an alternative non-toxic treatment of luminal amoebiasis.

Animals↗
PubMedDate not supplied

Sputum concentration improves diagnosis of tuberculosis in a setting with a high prevalence of HIV.

Sputum microscopy for acid-fast bacilli (AFB), although relatively insensitive, is still the cornerstone of tuberculosis (TB) diagnosis in the developing world. Its diagnostic value has been eroded owing to the increasing number of HIV-related smear-negative pulmonary TB cases. Concentration of sputum by centrifugation after liquefaction with sodium hypochlorite is a possible means of increasing the sensitivity of direct microscopy. This procedure has been studied recently in developing countries although with conflicting results. The aim of our study, performed in 1996 in Addis Ababa, Ethiopia, was to evaluate the sensitivity of the concentration method in a large cohort of consecutive patients with suspected pulmonary TB. We show that the overall sensitivity increased from 54.2% using conventional direct microscopy to 63.1% after concentration (P < 0x0015). In HIV-positive patients, sensitivity increased from 38.5% before to 50.0% after concentration (P < 0x0034). The significant increase in yield of AFB in HIV-positive patients suggests that this method has a place in routine diagnosis of pulmonary TB in countries with a high prevalence of HIV.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Stability of individual antimycobacterial precipitation patterns during treatment for lepromatous leprosy.

Sixty serum specimens obtained from 16 lepromatous patients at intervals during the first year of DDS treatment were studied in crossed immunoelectrophoresis against an M. leprae sonicate for possible variations of specificities and titers of antimycobacterial antibodies. All sera tested showed antibody activity against M. leprae, the number of precipitation lines produced varying between two and seven. In individual patients the numbers and positions of the precipitation lines remained remarkably constant throughout the period of study.

Adolescent↗