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At least 19 recordsLinked to original sources
PubMed1993

Physico-chemical conditions necessary for the in vitro excystment of Zygocotyle lunata (Trematoda:Paramphistomatidae).

Various physico-chemical factors associated with the in vitro excystment of metacercariae of Zygocotyle lunata were studied. Metacercariae could excyst with or without the presence of trypsin or bile salts, although the rate of excystation was slower in the absence of both. Crude ox-bile extract promoted faster excystment than did more refined sodium taurocholate. Pretreatment of cysts with pepsin also resulted in faster excystment rates. Optimal excystation occurred at 40 degrees C and between pH 5.5 and 7.5. The broad pH and temperature ranges and the non-specific enzyme/bile salt requirements for excystation were correlated with the wide range of vertebrate hosts used by this trematode.

Animals↗
PubMed1982

Effects of carbon dioxide, temperature, pH and the number of worms on the in vitro survival, histology and histochemistry of Paramphistomum cervi (Paramphistomatidae: Digenea).

Survival of immature and mature stages of Paramphistomum cervi, collected from the intestine and the rumen of sheep has been studied in in vitro using Tyrode's, Hank's, Eagle's, Stephenson's saline and Hedon--Fleig media. Twenty-five ml quantities of carbon dioxide (CO2)-rich Hedon--Fleig solution at pH 6.7, at 37 degrees C supported the maximum survival of 5 worms of both immature and mature flukes for periods of 9 and 10 days, respectively. Alterations to the pH of the medium, the incubation temperature and the number of worms significantly affected the period of their in vitro survival. The tissues of immature and mature worms did not show any marked histological and histochemical change until 24 h of in vitro survival in Hedon--Fleig solution when the testes of adult worms started undergoing degeneration. There was a progressive depletion of stored lipids and carbohydrates in the parenchymatous tissue during the course of in vitro survival. After the second day of in vitro maintenance, the maturation of the worms' vitelline follicles was affected, and thereafter they started to degenerate. On Day 4, degeneration of some gastrodermal cells, and a ruptured body wall were observed in some worms. Though the degenerative changes in the tissues of worms appeared at 24 h and continued to increase during in vitro maintenance, the worms survived for 9-10 days.

Animals↗
PubMed1987

Histochemical studies on eggshell formation in Paramphistomum cervi (Digenea: Paramphistomatidae).

The formation of the egg mass in the ootype, containing the oocyte, vitelline cells, numerous spermatozoa and Mehlis' gland secretion marks the beginning of eggshell formation. Mehlis' gland cells pour their lipoprotein secretion into the ootype; this secretion forms a thin template around the egg mass and upon this template the shell globules are deposited. Eggshell formation begins in the proximal uterus and is completed in the middle uterus. The eggshells are devoid of phenols and phenolase indicating that hardening is not by quinone tanning. The eggshells contain keratin and are stabilized by disulphide linkages.

Animals↗
PubMedDate not supplied

Catadiscus pomaceae sp. n. (Trematoda, Paramphistomatidae) from Pomacea canaliculata (Lamarck, 1801) (Prosobranchia, Ampullariidae).

Catadiscus pomaceae sp. n. from the intestine of the prosobranch mollusc Pomacea canaliculata (Lamarck, 1801), is described. The host snail was collected from a lenitic biotope belonging to the Riachuelo basin (Corrientes province, Argentina) during 1985-1986. So far the species of the genus Catadiscus Cohn, 1904 have been recorded in amphibians and reptiles. This is the first instance of a species of that genus parasitizing a mollusc.

Animals↗
PubMed1986

Morphological and histochemical studies on the development of testis and spermatogenesis in the ruminal trematode of sheep, Paramphistomum cervi (Digenea: Paramphistomatidae).

Morphological and histochemical changes accompanying testicular development and spermatogenesis have been described in the ruminal trematode Paramphistomum cervi during the course of its infection in sheep. Small testes of 4-week-old worms contain a few primordial germ cells. Spermatogonial cells appear first in 6-week-old worms and increase in number by the 10th week when the testes become large and follicular. Mature spermatozoa appear in the testes of 16-week-old worms. General pattern of spermatogenesis is the same as described for other trematodes, i.e. a single spermatogonium gives rise to 32 spermatozoa. Cytophore is formed at secondary spermatogonial stage. Various spermatogenic stages contain proteins, glycogen and phospholipids, however, the amount of phospholipids decreases as the maturation proceeds. The mature spermatozoa stain strongly with PAS. The enucleated residual mass contains HgBB-positive proteins and lipid granules. The morphological and cytochemical changes occurring during various spermatogenic stages have been correlated with corresponding histoenzymological changes in the cytoplasm. Frequency of spermatogenesis has been worked out which indicates that the transformation of secondary spermatogonia into spermatids is relatively fast as compared to transformation of primary spermatogonia into secondary spermatogonia and stages of spermateleosis.

Animals↗
PubMed1984

Morphological and histochemical studies on the ovarian development and oogenesis in Paramphistomum cervi (Digenea: Paramphistomatidae).

The ovary in 4-week-old worms contains undifferentiated germ cells. The oogonial differentiation, together with the appearance of some PAS-positive material in the ooplasm occurs in the ovary of 8-week-old worms. The ovary of 16-week-old worms contains only oogonia and oocytes and no germ cells. In adult worms, the oocytes reach the pachytene stage and further development is arrested at this stage. Nucleolar fragmentation and subsequent transport of nuclei to the ooplasm have been observed. The ooplasm contains nutritive material rich in proteins, carbohydrates and lipids. Its amount varies with different stages of oogenesis. The localization of various phosphatases and dehydrogenases was studied during oogenesis and their functional significance was discussed.

Animals↗
PubMed1982

[Study of the therapeutic efficacy of Nilsan preparation against Paramphistomatidae and nematode infections in sheep].

Experiments were carried out with the preparation Nilsan (oxiclozanide + levamizal) in the treatment of sheep with Fasciola, Dictyocaulus, and Trichostrongylus infection. The trials involved a total of 2782 sheep on two sheep-breeding farms, constituting 15 flocks. The liveweight of the adult animals ranged from 40 to 60 kg, and that of the year-old female ones--from 40 to 45 kg. The daily ration on the two farms did not differ essentially from that offered to the animals in the past 2-3 years. It was found that at the rate of 22 to 28 cm3 per head Nilsan produced 76.67 to 96.67 percent effect against Paramphistomum infection, 100 percent effect against Dictyocaulus infection, 73.37 to 90.00 percent effect against Trichostrongylus infection, and 23.34 to 83.34 percent effect against Dicrocelium infection. The application of an ex tempore combination of oxiclozanide and levamizal to sheep at the rate of 24 cm3 per head produced 86.67 to 100 percent effect against Paramphistomum, 96.67 to 100 percent effect against Dictyocaulus, 86.67 to 96.67 percent effect against Trichostrongylus, and 46.67 to 86.67 percent effect against Dicrocelium. The experimental sheep produced 16.41 to 37.40 per cent more wool, 0.85 to 35.09 per cent more milk, and 8 to 12 per cent more weight gain.

Animals↗
PubMed1992

Comparison of the hemoglobins of the platyhelminths Gastrothylax crumenifer and Paramphistomum epiclitum (Trematoda: Paramphistomatidae).

1. Gastrothylax crumenifer and Paramphistomum epiclitum parasitize the water buffalo Bubalus bubalis. 2. Gastrothylas hemoglobin consisted of two fractions of ca 30,000 and ca 18,000 by gel filtration. SDS-electrophoresis showed both to be single, ca 15,000 chains. 3. Paramphistomum hemoglobin was ca 16,000 by both gel filtration and SDS-electrophoresis. 4. Reversed-phase chromatography of carboxymethylated trematode and buffalo globins gave single peaks and two peaks, respectively. Although Paramphistomum hemoglobin provided and N-terminal sequence, Gastrothylax hemoglobin did not, suggesting blocked N-terminals. The buffalo sequences were found to be identical to the sequences of the alpha and beta chains of bovine hemoglobin. 5. Although Paramphistomum hemoglobin consists of only one chain, Gastrothylax hemoglobin consists either of one chain which aggregates to a dimer or of two different chains, only one of which aggregates to a dimer.

Amino Acid Sequence↗
PubMed1976

Comparative histochemical observations on the lipids in the immature and mature stages of Cotylophoron cotylophorum Paramphistomatidae: Digenea.

Immature and mature stages of the sheep amphistome Cotylophoron cotylophorum have been analysed histochemically for their lipids. Excretory ducts of the immature worms were the common sites for the accumulation of neutral lipids (triglycerides) and phospholipids which showed very sparse distribution at the corresponding sites in the adult. Phospholipids and lipoproteins observed in the tegument of the adult could not be seen in the immature form. Intestinal caecae of both forms showed the presence of diffused and granular lipids which were relatively less in the immature. The possible physiological significance of these differences in the lipid contents of the immature and mature forms has been discussed.

Animals↗