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Biomedical subjects

M C Henry

Publications and source records attributed to M C Henry.

At least 19 recordsLinked to original sources

[Opportunistic parasitic diseases in Africa. Clinical aspects and diagnosis].

Opportunistic parasitic infections are diagnosed more and more often in African patients with AIDS. Cryptosporidiosis is the most frequent with a prevalence between 7 and 31%. The prevalence of Isospora belli is between 5 and 19% and that of strongyloidiasis between 2 and 5%, depending on the authors. These parasitic infections are probably one of the frequent causes of chronic diarrhea in Africa. The prevalence of toxoplasmosis and pneumocystosis are not well known. (Between 5 and 17% for toxoplasmosis and 29% for pneumocystosis). The diagnostic technics used are those currently known. Toxoplasmosis and pneumocystosis seen in these patients have the same presentations as those in developed countries.

Acquired Immunodeficiency Syndrome

The onchocerciasis focus at Kinsuka/Kinshasa (Republic of Zaire) in 1985. I. Entomological aspect.

The entomological aspect of the onchocerciasis focus at Kinsuka/Kinshasa has not been studied since vector control was carried out in 1948. As in 1940, larvae of Simulium damnosum s.l. are located in the arm of the Zaire River flowing between Mimosa Island and the Zairian bank. They are, however, scarce. Cytotaxonomic studies showed that the S. squamosum group was the only member of the S. damnosum complex present in the region of Kinshasa. Physico-chemical analysis of the water at breeding sites determined that S. squamosum larvae develop in neutral or acid water with a conductivity of less than 50 micronhos cm-1 and a low concentration of dissolved salts. Longitudinal study showed that the 'annual biting rate' (ABR) and the 'annual transmission potential' (ATP) fluctuate from 2406-5999 bites man-1 year-1 and from 120-236 infective larvae man-1 year-1 respectively. The low transmission rate at Kinsuka is mainly due to the low level of the biting population occurring during the main river rising. The increase in Kinsuka's population has reinforced this situation by 'diluting' the parasite in the human reservoir.

Animals

The onchocerciasis focus at Kinsuka/Kinshasa (Republic of Zaire) in 1985. II. Parasitological and clinical aspects.

Since the antivectorial control in 1948, the parasitological and clinical aspects of the onchocerciasis focus at Kinsuka/Kinshasa have not been studied further until now. The population examined was selected for its daily contact with the vector. It constituted 143 adults, including fishermen, stonebreakers and women cultivators, and 26 children aged from 10 to 16 years. People were subjected to an ophthalmological examination as well as to an investigation for Onchocerca volvulus microfilariae. Adults were examined for the presence of nodules as well as for dermal and lymphatic manifestations of onchocerciasis. The microfilaria carrier rate (MfCR) was 59.2%. The mean microfilaria density (MfD) was 9.7 mf mg-1. Only 20% of the adults presented with small onchocercal nodules. Cutaneous lesions were mild. Lymphatic complications such as adenolymphocele, hydrocele and elephantiasis of the lower limbs were observed in 18% of the adults. No one was blind from onchocerciasis, although nine patients of 60 years or over had lost the use of one eye. Punctate keratitis occurred commonly in young people. Ocular lesions, except for punctate keratitis, developed progressively after 55 years and they became worse with the degree of infection, age and length of stay. Hyperendemic and insufferable in 1940, onchocerciasis has become, in 1985, hypoendemic and no longer a public health problem. One could deduce that a situation similar to that in Kinsuka may occur within 30 years in other foci which are today hyperendemic and where prophylaxis has been started.

Adolescent

Parasitological observations of chronic diarrhoea in suspected AIDS adult patients in Kinshasa (Zaire).

The parasitological profile of chronic diarrhoea in 46 Zairian adults suspected of Aids demonstrated that the frequency of protozoa was five times higher than that of helminths; 86% of the protozoa were sporozoa: Isospora belli was the most frequent (19%), followed by Cryptosporidium isolated for the first time in Zaire (8%) and Blastocystis hominis (2%). 37 of the 46 patients were immunodeficient.

Acquired Immunodeficiency Syndrome

Preliminary data on the genetic differentiation of Onchocerca volvulus in Africa (Nematoda: Filarioidea).

Data are reported on the genetic structure of three Onchocerca volvulus populations, respectively from Mali (savanna), Ivory Coast (forest), and Zaire (forest gallery in savanna). Electrophoretic analysis, carried out on 25 gene-enzyme systems, has shown a remarkable genetic heterogeneity existing within O.volvulus. Zaire and West Africa populations appear chiefly differentiated at Mdh-1 and 6Pgdh loci, their average Nei's genetic distance being 0.11. In West Africa Nei's D found between the savanna and forest samples is 0.04. The savanna population from Zaire is more similar to the savanna one from Mali (D = 0.09) than to the forest one from Ivory Coast (D = 0.13). This appears mainly due to the loci Ldh and Hbdh (possibly linked), some alleles of which seem to be selected for in forest populations (Ldh110, Hbdh108), while others in the savanna ones (Ldh100, Hbdh100). The hypothesis that the discrepant epidemiological patterns of human onchocerciasis are related to intrinsic differences in the parasite seems supported by the obtained data. The differences in allele frequencies found at the reported loci appear strong enough to allow biochemical identification of O. volvulus populations from different geographic regions and different habitats.

Alleles

Effect of particle size distribution on hexamethylmelamine toxicity in rats.

Single oral dose toxicities of six hexamethylmelamine samples with different particle size distributions were evaluated in Osborne-Mendel rats. The calculated LD50 values for the 6 samples were 1706 to 2150 mg/kg )10,236 to 12,900 mg/m2). The two samples with median particle size less than 40 micron were more toxic than the other 4 samples. Among the latter samples, severity of toxic effects was not correlated with particle size. Leukocytes, lymphocytes, platelets and body weight showed dose-related decreases for all samples. Particle size appeared to have a minimal effect on these variables. The drug produced toxic effects on rapidly proliferating tissues: lymphoid, hematopoietic and germinal epithelium. At lethal doses, microscopic lesions were lymphoid tissue hypoplasia, bone marrow hypoplasia with elevated myeloid:erythroid ratios and spermatogenic arrest. The major target organs at nonlethal doses were bone marrow and germ cells, with germinal epithelium showing the most severe lesions.

Altretamine