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Biomedical subjects

M Larivière

Publications and source records attributed to M Larivière.

At least 19 recordsLinked to original sources
PubMed1994

[Microsporidioses].

Microsporidia are worldwide ubiquitous intracellular protozoan parasites infecting most major groups of the animal kingdom. In humans, microsporidiosis has recently emerged as a significant cause of morbidity in immunocompromised patients, and particularly in patients with acquired immunodeficiency syndrome (AIDS). Parasites of the genus Encephalitozoon cause keratoconjunctivitis and disseminated infections. In 15 to 30% of patients with advanced stage AIDS, Enterocytozoon bieneusi is the causative agent of major chronic diarrhoea. Clinical manifestations include numerous (2 to 8) and abundant, irregular liquid or semi-liquid stools without evidence of intestinal haemorrhage. Impaired absorption is aggravated by food intake causing the patients to restrain from eating and subsequent weight loss is progressive and irreversible. The diarrhoea becomes permanent and leads to dehydration ad malnutrition. Spontaneous remissions have been observed but are always of short duration. Microsporidiosis has also been found in ocular localizations in patients with AIDS; these keratopathies may be due to Encephalitozoon cuniculi, the only known species in mammals but E. hellem, a morphologically identical but antigenically different species has been identified. Other visceral localizations have been observed. Diagnosis of microsporidiosis relies on the demonstration of spores and/or intracellular parasites in stools, urine or tissue biopsies. The responsible agent can generally be identified by light microscopy, but differentiation between species still requires electron microscopy. New light and fluorescent microscopic techniques have been proposed for easier recognition of spores in various pathological samples. Immunodiagnostic techniques are limited due to the lack of correlation between antibodies detection and clinical manifestations. Although the parasite can be identified and although its cycle has been carefully studied, no prophylactic action can be taken because the mode of transmission remains largely unknown. Many treatment protocols have been tried but none have been found to be effective. Very little pharmacological data has been accumulated. Microsporidiosis is, and will remain, a major opportunistic infectious disease causing uncontrollable debilitating malnutrition in AIDS patients unless an effective treatment can be found, a major challenge for medical science.

AIDS-Related Opportunistic Infections↗
PubMed1993

[Epidemiology of human bilharziasis].

Schistosomiasis is endemic in three continents: Africa, where Schistosoma haematobium, S. mansoni and S. intercalatum are present; tropical America and some of the the Caribbean islands, where the only parasite of this type is S. mansoni; Mediterranean Asia (S. haematobium, S. mansoni) and the Far-East (S. japonicum, S. mekongi). Schistosomal infestation is distributed in foci of warying size and significantly differs in prevalence, intensity and therefore morbidity from one region to another. Despite the successes obtained in the neutralization of certain foci, the great plasticity of the hosts-parasites-molluscs relations and the huge displacements of human populations in the poorer countries explain why the epidemiology of schistosomiasis is constantly changing and the disease is far from disappearing.

Animals↗
PubMed1989

[A study in the Ivory Coast (1985-1987) of the efficacy and tolerance of ivermectin (Mectizan) in human onchocerciasis. I. A comparative double-blind study of 220 patients with onchocerciasis treated with a single oral dose of 100, 150 or 200 mcg/kg].

Two hundred and twenty adult males living in endemic onchocerciasis areas in Ivory Coast, with a mean of 59 to 64 mf/mg of skin microfilariae, having or not ocular lesions, were divided into 4 homogeneous groups and treated by placebo or by a single oral dose of 100, 150 or 200 mcg/kg of ivermectin. Parasitological, clinical, ophthalmological, biological data were gathered before treatment (J less than 1) and at day 4 and 3, 6, 12 months post treatment. The doses of 150 to 200 mcg/kg gave the best results with a reduction of microfilariae of 75 to 79% at day 4 and of 97 to 99% at 3 months. A slight increase appears at six months reaching to 10% of the initial level, at 12 months. These posologies reduce also the number of ocular microfilariae 12 months after treatment. The percentage of patients presenting microfilariae in the cornea varies from 4 to 14% according to the given dose whereas it was initially between 26 and 33%, and in the anterior chamber from 22 to 16% instead of 62 to 67%. In patients who were still positive after treatment the detected number of ocular microfilariae was very small. Side effects starting 12 to 24 hours after treatment are similar to those appearing during the normal evolution of onchocerciasis. They were observed in 36% of subjects receiving a placebo and 56 to 65% of treated subjects. Statistically they are neither correlated with the intensity of parasitism nor to the given posology and disappear spontaneously few days later or after administration of aspirin and/or antihistaminic. Ivermectin given at a single oral dosage of 150 to 200 mcg/kg is a powerful microfilaricidal drug with a rapid and prolonged action and without major side effects.

Adult↗
PubMed1989

[A study in the Ivory Coast (1985-1987) of the efficacy and tolerance of ivermectin (Mectizan) in human onchocerciasis. II. Evaluation in the light of mass campaigns on the effect of yearly or half-yearly administration of single oral doses of 100, 150 or 200 mcg/kg].

One hundred and twenty patients out of 220 in a previous study were retreated after 6 months or one year with doses of 100, 150 or 200 mcg/kg of ivermectin. The tolerance was excellent due probably to the small number of skin microfilariae obtained with the first treatment. The annual treatment with 150 to 200 mcg/kg, better than with 100 mcg/kg, keeps for the year following the second treatment the microfilariae number between 6 and 11% of the initial level. The half-yearly administration keeps it between 1 and 7% and especially 94 to 100% of these retreated patients have a level of microfilariae less than 5 mf/mg. The results obtained with the half-yearly treatment show a considerable reduction of the number of microfilariae in the anterior chamber of the eye and the percentage of positive patients. Ivermectin is a very efficient microfilaricidal drug for the treatment of onchocerciasis and the prevention of ocular complications. Its rational use in mass campaigns should reduce, if not interrupt, the transmission of this parasitic disease.

Administration, Oral↗
PubMed1989

[A study in the Ivory Coast (1985-1987) of the efficacy and tolerance of ivermectin (Mectizan) in human onchocerciasis. III. The tolerance and efficacy of a single oral dose of 150 mcg/kg in children].

One hundred and three male and female children of 6 to 14 years old with onchocerciasis, having or not ocular involvement and a mean skin microfilariae level of 36.1 mf/mg, received, in October 1986, a single oral dose of 150 mcg/kg ivermectin and controlled at day 4, 3 months, 6 months and 12 months post treatment. After the last control they were retreated with the same dose. The skin microfilariae count fell down to 94% of the initial level at day 4 and to 99% at 3 months. At 6 months the microfilariae count was 2% of the initial level and 5% at 12 months. The percentage of patients having microfilariae in the anterior chamber of the eye which was 33% before treatment fell down to 6% at 12 months. The percentage of patients having microfilariae in the cornea was 39% before treatment and 18% at 12 months. In the cornea and anterior chamber there was a very reduced number of microfilariae still present. 65% of the children had lesions of keratitis before treatment and 34% two months later. Adverse effects (fever, headache, pruritus, oedemas, myalgias, arthralgias) occurred in 64% of children after the first treatment and 50% after the second. They were of weak or moderate intensity and receded rapidly after administration of aspirin and/or anti-histaminic. The administration of ivermectin is an efficient and well tolerated drug in children above 5 years old.

Administration, Oral↗
PubMed1989

[Comparative study of 2 classical technics of coloration and an indirect immunofluorescent assay applied to research on Pneumocystis carinii in the bronchoalveolar lavage fluid and induced sputum in HIV+ patients].

Two histochemical staining methods, eosine-methylene blue fast (RAL 555) and silver methenamine (modified Grocott's technique), and indirect immunofluorescence assay with an anticyst monoclonal antibody were used to detect Pneumocystis carinii in the broncho-alveolar lavage fluid and induced sputum from 58 HIV+ patients. Immunofluorescence disclosed the largest number of carriers (35 p. cent of examined patients). However, the histochemical staining techniques remain of interest and are the initial method of choice. They are inexpansive and rapid to achieve; less sensitive than immunofluorescence, positive results argue a high enough level of parasitism which leads to clinical manifestations. The increased sensitivity of immunofluorescence has considerably improved the ability to detect Pneumocystis in induced sputum. It allowed us to disclose 18 out 20 carriers (90 p. cent). However when a Pneumocystis is suspected, it is preferable to sample bronchoalveolar lavage fluid. Its examination is quick, easy and quantitative appreciation of results bring important diagnostic arguments. Other parasites, such as toxoplasmas, may also be detected. On the other hand, the examination of expectoration is time consuming and difficult to read and interpret. Therefore, sputum induction for the diagnosis of Pneumocystosis should be reserved to unequiped centers or insufficiently equiped centers (i.e., devoid of intensive care units).

Acquired Immunodeficiency Syndrome↗
PubMed1989

[A study of ivermectin in the treatment of lymphatic filariasis due to Wuchereria bancrofti var. pacifica in French Polynesia].

Forty carriers of 20 or more W. bancrofti var. pacifica per ml were blind administered ivermectin at 50, 100, 150 or 200 mcg/kg doses. The rate of successful treatment was 100% with the 4 dosages. The percentage cure rate and the decrease percentage in the microfilarial count were significantly higher in persons treated with 100, 150 and 200 mcg/kg than in persons treated with 50 mcg/kg. Frequency and intensity of side-reactions were similar to those observed during treatment with DEC; they were more frequent and severe in persons with greatest microfilaremia but did not depend on the dosage. Ivermectin in 100 mcg/kg single-dose, administered once a year, is the best candidate to replace DEC in mass treatments.

Adult↗
PubMed1987

[Ivermectin in the treatment and prevention of human onchocerciasis].

Ivermectin is a synthetic derivative of a macrocyclic lactone produced by an actinomycete Streptomyces avermitilis. It has a broad spectrum antiparasitic activity against nematodes and certain acarians in animals. The microfilaricide action of this product against horse and cattle onchocercosis led to the study of its effects in human onchocercosis against O. volvulus. Several trials performed mainly in endemic zones of Africa showed that this drug was more effective than the reference microfilaricide, diethylcarbamazine. A single oral dose of 200 micrograms/kg of Ivermectin reduces the dermal microfilaria population to nearly zero within a few days and the effect is maintained for at least 6 months. Secondary ocular or systemic effects are rare, negligible and transitory. The prolonged elimination of dermal microfilariasis caused by sequestration followed by degeneration of the microfilaria in the uterus of females raises the hope that Ivermectin used in a single annual or bi-annual dose will contribute to the interruption of the transmission of this serious parasitic disease.

Administration, Oral↗
PubMed1983

[Treatment of human onchocerciasis with ivermectin].

Twenty immigrants from Mali and West Senegal were treated in Paris. Onchocerciasis was diagnosed by six skin snips using a Holth punch. Ivermectine was given in a single oral dose: ten patients were given 50 mcg/kg, three were given 75 mcg/kg and seven received 100 mcg/kg. No patients had ocular symptoms. The results were as follows: Pruritus disappeared rapidly in 9 out of 11 patients who itched before treatment. The microfilarial load decreased rapidly, especially in cases treated with 75 mcg/kg and 100 mcg/kg as all patients tested on day 60 were negative. Clinical signs of the Mazzotti reaction and ocular reactions were not observed following the treatment. Pruritus was briefly aggravated in only two patients. No cardiovascular, hematological, hepatic or renal toxicity was noted.

Administration, Oral↗