Illness and health behaviour in Addis Ababa and rural central Ethiopia

This paper examines the results of health surveys among 544 randomly selected households (2829 people) in seven kebele (urban dwellers' associations) in Addis Ababa and Kaliti, an industrial suburb of Addis Ababa, and in four rural villages in two peasant associations. The major objective was to study illness distribution and health behaviour among different socioeconomic and cultural groups in urban and rural communities within the context of available health resources, national health policy and planning. Results show that in spite of the rapid expansion of health services since the Ethiopian revolution serious problems of allocation and access persist. Higher illness prevalance rates were found in rural areas (23.2%), Kaliti (25.5%) and in the low socioeconomic kebele in Addis Ababa (23.9%) than in the high socioeconomic kebele (16.5%), but rural/urban and intraurban differences were greater than reported here due to underreporting. One-third of all illnesses were treated by modern services, 19.9% by self care and 26.0% by traditional medicine and transitional healers, with 21.5% of all illnesses not being treated. Utilization rates varied with type and duration of illness, socioeconomic level, age, sex and place of residence. The role of distance and other contact barriers, treatment outcome and availability of private clinics and alternative health resources in utilization is also evaluated. Coverage of the modern health services was associated with socioeconomic status and mobility of patients as well as availability of health services.

Interaction of carboxypeptidase A with monoclonal antibodies

Several mouse monoclonal antibodies to carboxypeptidase A (CPA) were prepared and purified, and their interaction with the enzyme was investigated. CPA is a well-characterized zinc-containing exopeptidase exhibiting peptidase as well as esterase activity. The antibodies obtained could be classified as follows: antibodies inhibiting mainly the peptidase activity of the enzyme, antibodies inhibiting mainly its esterase activity, antibodies affecting both activities, and antibodies which bind to the enzyme but have no marked effect on its catalytic properties. Binding constants of approximately 10(6) M-1 were obtained for most of the antibody-enzyme complexes tested. Additional information on the effect of the monoclonal antibodies on the active site of CPA was obtained by determining the change in the circular dichroism spectra of arsanilazotyrosine-248 carboxypeptidase A occurring as a result of the interaction of the enzyme with the antibodies studied. These findings suggest that CPA possesses at least three different specific antigenic sites, and that the active site of the enzyme for its peptidase activity differs from that for its esterase activity, though both sites seem to overlap to a considerable extent.

Transfer of insulin receptors and of glucose transport-inducing proteins onto phospholipid vesicles

Insulin receptors and glucose transport-inducing proteins have been extracted from rat liver membranes onto positively charged lipid bilayer vesicles. The extraction was carried out during the incubation of the vesicles with lipid vesicles caused an overall enhancement of specific insulin binding and of glucose transport inducement. The latter has been inferred from the oxidation rate of transported glucose through a spherical bilayer membrane entrapping the oxidizing glucose oxidase. Glucose transport is not enhanced by insulin binding, indicating that the two functions baecome dissociated when the proteins are transferred from the plasma membrane onto the bilayer vesicles.

Interaction of glucose oxidase with phospholipid vesicles

The interactions between glucose oxidase and phospholipid vesicles were investigated. The investigations were carried on molecules adsorbed on the outer surfaces as well as entrapped in the interior of the vesicles . The adsorption of glucose oxidase on the surfaces of egg egg licithin vesicles, containing varying amounts of cholesterol and stearoylamine was measured by determining the free fraction of glucose oxidase detected in the filtrates. In general an enhancement of enzymic activity was observed upon interaction with the vesicles. The enhancement depends on the lipid composition of the vesicles and the surface concentration of the adsorbed glucose oxidase. It reached a maximal value at a surface concentration of 1.4-10(11) molecules/cm2 (approximately 7.1 - 10(4) A2/molecule) on pure phosphatidylcholine vesicles and about 6.5 - 10(10) molecules/cm2 (approximately 16 - 10(4) A2/molecule) when the vesicles contained cholesterol or cholesterol and stearoylamine. CD measurements indicated that the change in enzymic activity of the adsorbed glucose oxidase was accompanied by conformational modification of the enzyme. In order to entrap glucose oxidase into the vesicles, the lipid was sonicated in the presence of the enzyme. After removal of the free and adsorbed enzyme the amount of the entrapped enzyme was determined by measuring its activity after disintegration of the vesicles with Triton. The enzymic activity of the entrapped glucose oxidase served as a measure for the permeability of the bilayer membrane of the lipid vesicles to glucose. Addition of insulin to the suspension of vesicles containing the entrapped glucose oxidase increased the permeability of glucose by up to 9 - 10(-8) cm/s. This value is the lowest estimate based on the assumption that one glucose oxidase molecule was entrapped in every vesicle.

Adenosine 3',5'-cyclic monophosphate and morphology in Neurospora crassa: drug-induced alterations

Grown in liquid culture in the presence of a variety of structurally unrelated drugs, mycelia of wild-type Neurospora assume a colonial or semicolonial growth habit similar to that of known morphological mutants. Drugs that produce these morphological changes include atropine, theophylline, histamine, and several of the quinoline-containing antimalarials. Each of these drugs decrease the endogenous adenosine 3',5'-cyclic monophosphate (cAMP) concentration of mycelia as a result of their effect on the activity of adenyl cyclase, the cAMP-dependent phosphodiesterase, or both. The evidence indicates a relationship between the degree of morphological abnormality, the degree to which intracellular cAMP is reduced, and the action of the drugs on the adenyl cyclase and phosphodiesterase.