Biomedical subjects
Publications and source records attributed to A F Petavy.
A cat living in the city of Annemasse (Haute-Savoie) was parasitized by a single minute specimen of the cestode E. multilocularis. The main characteristics of the parasite are described and illustrated. The cat has not previously been reported as one of the definitive hosts of this cestode in France. A potentially serious epidemiological problem is raised by the presence of an infected cat in an urban estate.
A study on the biochemical and ultrastructural effects of isatin on Echinococcus multilocularis metacestodes in Meriones unguiculatus is reported. In the metacestode, after an 18 day treatment period, the alkaline phosphatase and lactate dehydrogenase activities decreased and the acid phosphatase activity increased. Glucose and glycogen stores declined significantly. Examinations of the ultrastructure revealed an increase of lysosomes and phagocytic reactions. The protoscolesces were damaged and an abnormal striated process appeared. The tegumental cytoplasmic syncytium remained unaltered. These observations suggest that isatin derivatives may have a role in the chemotherapy of infections caused by Echinococcus spp.
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A comparative study of the kinetic parameters of glycogen synthase was performed on Echinococcus multilocularis metacestodes and on the livers of infected and control host (Meriones unguiculatus). The enzyme of the parasite was found to be different from the enzyme of infected host liver. The apparent Km for UDP-glucose is 100 microM for the parasite and 400 microM for the host liver. The apparent Km for glucose 6-phosphate is 4 mM for the parasite and 2 mM for the host liver. The apparent Km for glycogen is 16 mg/ml for the parasite and 125 mg/ml for the host liver. The influence of glucose 6-phosphate and exogenous glycogen on the activity of glycogen synthase differs between the metacestode and the host liver. The enzyme of the metacestodes apparently does not need exogenous glycogen to work, contrary to the case for the liver host enzyme. The glycogen synthase of the parasite seems to be present in forms I and D, whereas the enzyme of the host liver appears in form I and that of the control liver in form D.
The effect of isatin on the E. granulosus cyst was studied. NMRI mice, which were infected with E. granulosus of sheep origin, were treated daily with isatin at a dose of 50 mg kg-1 for 18 days. Ultrastructural damage was observed in the treated cysts, including accumulation of lamellar stacks, electron-dense granules, autophagosomes and lipid vesicles. Moreover, a biochemical study showed an inhibition of alkaline phosphatase activity, with a decrease in carbohydrate storage and an increase in acid phosphatase activity. In spite of the short duration of the treatment, the results obtained allowed us to conclude that isatin acts on E. granulosus cysts. This activity appears as a process of degeneration linked to the alkaline phosphatase inhibitory effect of isatin.
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Kinetic and physical parameters of UDP-glucose pyrophosphorylase were determined in Meriones unguiculatus infected with Echinococcus multilocularis metacestodes (cestoda). Studies were carried out on parasite cysts, and on livers from control and infected animals after purification of the enzyme by affinity chromatography on UTP-agarose. The enzyme from infected and control livers had km values for UTP of 0.01 mM and 0.5 mM, respectively; for glucose-1-phosphate values were 0.46 mM and 0.07 mM, respectively. On the other hand the enzyme from cysts was found to have a higher Km for UTP (1 mM) and for glucose-1-phosphate (1.5 mM) than from infected or non-infected livers. Physical characteristics (pI = 6 and Mr = 160,000) of UDP-glucopyrophosphorylases were the same in controls and infected host livers but were different from the cyst enzyme (pI = 7 and Mr = 251,000). These results provide evidence for the existence of significant differences between parasitic and host enzymes, which could possibly be exploited in chemotherapy.
Alkaline phosphatases (E.C.3.1.3.1), membranous enzymes of the cestode Echinococcus multilocularis have been studied in the parasite and in the experimental host liver. Synthetic inhibitors interaction with metacestode alkaline phosphatases is reported. In regard to the alkaline phosphatases inhibition, the ethyloxanilate 2 is more efficient in the cestode itself than in the host liver.
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The authors describe lesions of Echinococcus multilocularis larvae found in one of 476 Clethrionomys glareolus and one of 16 Arvicola terrestris examined from Lorraine and in four Microtus arvalis from Jura. The receptivity of each of these host-species is discussed.
Eleven metabolites were determined in 19 hydatid cyst fluids of variable size and localization, and in patients plasma before surgery. Specific indirect immunofluorescent antibody titration was carried out. Sodium (132 +/- 5.2 mmol/l), chloride (92.9 +/- 6.5 mmol/l) and bicarbonate (22.1 +/- 1.5 mmol/l) were found at the same concentration than in plasma. Potassium (5.4 +/- 0.3 mmol/l) and calcium levels (4.7 +/- 0.9 mmol/l) were higher than in plasma, and phosphate (0.1 +/- 0.03 mmol/l) decreased tenfold. Glucose (3.4 +/- 0.8 mmol/l), creatinine (39.3 +/- 7.2 mumol/l) and urea nitrogen (4.6 +/- 0.8 mmol/l) showed great variations. Cholesterol levels 0.06 +/- 0.03 mmol/l) were a hundredfold lower than in plasma. Total protein levels (0.34 +/- 0.09 g/l) were found at very low concentrations. Extra-pulmonary cysts showed significantly higher antibody titers than pulmonary cysts. No correlation was observed between the size of the cysts and the level of the immune response. Significant difference about the relative cholesterol concentration (cystic concentration/plasmatic concentration) was observed between pulmonary and extra-pulmonary cysts (respectively 0.0048 +/- 0.0032 and 0.018 +/- 0.01--p less than 0.05). No correlation was observed between the size of the cyst, or the corresponding levels of the immune response, and the cholesterol levels. The hypothesis of a greater membrane permeability in extra-pulmonary cyst is discussed.
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A study on the presence of oral Entamoeba gingivalis and Trichomonas tenax has been carried out on calculus or dental plaque from 117 diabetic subjects. Statistical analysis of results shows no correlation between diabetes and protozoa. The same frequency was found between diabetic and normal subjects. Nevertheless, a significant relation has been found between the diabetes and the yeasts.
The protozoa Entamoeba gingivalis and Trichomonas tenax together with yeasts of the genus Candida were investigated in the mouth (gums or neck of tooth) of 509 healthy or diabetic subjects. A study of the possible correlation between presence of these parasites and various local or general factors, showed that neither the sex, maxillo-facial anomalies nor smoking had any influence on parasite incidence. Entamoeba gingivalis was encountered in 85 per cent of subjects free from parodontopathy. Numerous factors influenced the presence of Trichomonas tenax: age, social status, alcohol consumption, dental condition and gingival pathology. Presence of Candida was associated with diabetes, poor buccal hygiene and dental condition.
The authors report a case of bilharzia localised to one of the ureters in a case of double renal pelvis and ureter. The parasitic infection was identified only at the time of exploratory surgery (laboratory investigations and preoperative endoscopy negative). The "providential" double ureter made it possible to combine excision of the pathological ureter with a termino-lateral anastomosis between the lower renal pelvis and the ureter of the upper renal pelvis. The result remains very satisfactory with a follow-up of 13 months.
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