Search PubMed⌕ Search

Biomedical subjects

W Frank

Publications and source records attributed to W Frank.

At least 127 records · Page 7Linked to original sources
PubMed1980

[The life-history of Sarcocystis singaporensis Zaman and Colley, 1976 in the definitive and intermediate host (author's transl)].

Sporulated oocysts and sporocysts (9.3 x 7.3 micrometer) of Sarcocystis singaporensis - isolated from freshly imported snakes (Python reticulatus) - were fed to various animals to test their function as suitable intermediate hosts (NMRI-mice, albino rats, Meriones unguiculatus, golden hamsters, guinea pigs, Mastomys natalensis, field-voles [Microtus arvalis], pigeons, and chickens). Only in rats were muscle-cysts formed. The optimal dose was 150 sporocysts per rat. Two generations of merogony could be observed, the first about the 6th day, the second about the 16th day post infection. In the skeletal muscles metrocytes were seen in the young cysts initially, and from the 40th day post infection cystozoites were present. The full grown muscle-cysts measured 1226 x 184 micrometer. They were chambered and possessed a 9.6 micrometer broad stable bristle layer. Older cysts (100 days post infection and more) had shorter processes. To demonstrate the complete life-cycle we fed cyst-containing rat muscles to four reticulated pythons. On the 8th and 13th post infection the feces for 73 to 117 days. Histologic examination of surgically removed parts of the midgut showed that gamogony and sporogony take place in the duodenum and the anterior third of the midgut. Oocysts with sporoblasts were first seen on the 4th day post infection.

Animals↗
PubMed1980

Camponotus compressiscapus André (Hymenoptera, Formicidae) an experimental second intermediate host of Dicrocoelium hospes Looss, 1907 (Trematodes, Dicrocoeliidae).

Infection experiments showed that the African ant Camponotus compressiscapus can serve as a second intermediate host of Dicrocoelium hospes. Most of the cercariae penetrated the crop-wall and encysted in the hemocoel, whereas one or more larvae invaded the ant's central nervous system. These larvae cause behavioral changes, which increase their chance of being ingested by final hosts. Experimental infections of definitive hosts were obtained in golden hamsters, Meriones unguiculatus, guinea-pigs, and sheep.

Animals↗
PubMed1980

Cerebral larvae in the second intermediate host of Dicrocoelium dendriticum (Rudolphi, 1819) and Dicrocoelium hospes Looss, 1907 (Trematodes, Dicrocoeliidae).

Cerebral larvae of Dicorcoelium dendriticum and D. hospes and the brains of infected ants were studied. Morphologic differences of the freed larvae could not be found, but there were evident differences in number and localization of the cerebral stages. Ants infected with D. dendriticum usually showed one "Hirnwurm" while in the majority of the ants infected with D. hospes two larvae were found. The typical localization of the "Hirnwurm" of D. dendriticum was in the ventral part of the subesophageal ganglion; almost every larva of D. hospes was found in the dorsal part of an antennal lobe. The cyst walls of the larvae were visible only in some specimens. Their thickness seemed to depend on the localization of the larva. Differences in number and localization of the larvae, and hypotheticalmechanisms how they could influence the behavior of their hosts are discussed.

Animals↗
PubMed1978

[A contribution to the biology of Dicrocoelium hospes Looss, 1907 (Trematoda, Dicrocoeliidae)].

In this study, carried out in the Ivory Coast, Dicrocoelium hospes Looss, 1907 was shown for the first time to be a parasite of cattle and it was also detected in sheep by the presence of ova in the faeces. Up to 50% of the sheep in some flocks were found to shed eggs. The adults, sporocysts, "slime balls" and cercariae of D. hospes are described and compared to the respective stages of D. dendriticum. This comparison shows that essential morphological structures are very similar, especially the sensory papillae, which as so called chaetotaxis can serve to distinguish closely related species. The cercariae develop in terrestrial snails of the genus Limicolaria of which several species may play a role (L. flammea, L. felina, L. kambeul). The main habitat of D. hospes seems to be limited to savannah environment; only once could D. hospes be found in the borderzone between savannah and the rain forest. Infected Limicolaria-snails shed the cercariae in amorphous "slime balls" of liquid-jelly-like consistency and yellowish colour. Under the influence of sunlight these liquify; the cercariae, however, can survive for up to 26 h. According to our present knowledge the sunlight seems to be a factor which triggers the shedding of slime balls. This begins shortly after sunrise at a temperature of 22 degrees C and a relative humidity of 100%. Infected snails can shed cercariae on seven consecutive days. This kind of slime ball production might provide a clue to the 2nd intermediate host; efforts to identify this host have, however, so far been fruitless, despite the fact that almost 4000 arthropods, mainly ants, have been investigated.

Animals↗
PubMed1977

Uremic hyperlipoproteinemia: correlation with residual renal function and duration of maintenance hemodialysis.

Our study indicates that in renal failure elevated plasma triglyceride can first be detected when the GFR falls to 50 ml/min. Hypertriglyceridemia is the commonest abnormality found and increases further when the GFR falls below 10 ml/min. Plasma cholesterol levels remain normal even at low levels of renal function. Although plasma growth hormone, glucagon, and insulin levels become elevated when renal function diminishes, there is no definite correlation of their levels and GFR. A decreased incidence of hyperlipidemia observed in patients sustained by maintenance hemodialysis for over 5 yrs may in part be due to the triglyceride lowering effect of growth hormone and glucagon and/or the cholesterol lowering effect of insulin.

Androgens↗
PubMed1975

Influence of potassium and calcium ions on the phosphatidylinositol and phosphatidylcholine metabolism in rat fibroblasts after growth stimulation by calf serum.

In secondary cultures of embryonic rat fibroblasts which were arrested in G1 (G0) by serum depletion and subsequently triggered into the cell cycle by readdition of growth factors isolated from fetal calf serum the influence of the potassium and calcium concentrations in the medium on phosphatidylinositol and phosphatidylcholine metabolism was investigated. The incorporation of inorganic [32P]phosphate into phosphatidylinositol is dependent on the potassium content of the culture medium. The specific activity of 32P in phosphatidylinositol is increased at K+ concentrations between 0.1 and 1 mM. Also calcium (between 0.01 and 2 mM) slightly stimulates phosphatidylinositol metabolism. Also the incorporation of myo-[3H]inositol is increased at potassium concentrations between 0.2 and 1 mM, whereas calcium is slightly inhibitory. The labelling of phosphatidylcholine with either [32P]phosphate or [3H]choline is not dependent on the potassium and calcium concentrations of the culture medium. Moreover, the phospholipid metabolism of permanently growing epithelioid and fibroblastoid cells lines, which were investigated, is considerably less dependent on the K+ and Ca2+ ions.

Animals↗