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Biomedical subjects

V Kitikoon

Publications and source records attributed to V Kitikoon.

36 records · Page 2Linked to original sources
PubMed1991

Factors affecting laboratory acclimatization of field collected Lymnaea (Bullastra) cumingiana Pfeiffer (Pulmonata: Lymnaeidae).

Lymnaea (Bullastra) cumingiana, the newly discovered natural second intermediate host of Echinostoma malayanum in the Philippines, is a sensitive and delicate lymnaeid species which requires certain conditions for successful transport from the field and cultivation in the laboratory. Field collected specimens were found to be best transported in styrofoam containers lined with wet filter paper or containing natural substrate and vegetation instead of Sphagnum moss. The method is convenient and produces a survival rate of 73-86%. However, transport time is crucial and mortality increases the longer the snails are in transit. For optimal results in laboratory acclimatization, snails are best raised in wide-mouthed containers providing a large exposed water surface area. Adequate aeration is advised but vigorous bubbling of the water should be avoided. Water should be replaced with filtered dechlorinated water every 2 to 3 days, depending on water quality. A combination of fresh lettuce leaves and a few flakes of fish food was found to be ideal. Lastly, population density was the most significant factor affecting survival and so overcrowding should be avoided.

Acclimatization↗
PubMed1989

Lymnaea (Bullastra) cumingiana Pfeiffer (Pulmonata: Lymnaeidae): second intermediate host of Echinostoma malayanum in the Philippines.

Adult flukes were obtained from laboratory rats and hamsters fed with metacercariae isolated from Lymnaea (Bullastra) cumingiana Pfeiffer and were identified as Echinostoma malayanum Leiper based on the presence of a circumoral collar of 43-45 spines and the highly lobed testes. This discovery is of public health significance because L. (Bullastra) cumingiana in eaten raw by certain local populations in northern Luzon. The proposed new species, Cathaemasia cabrerai (Jueco and Monzon, 1984), is probably invalid because it apparently was based on E. malayanum flukes that had lost their circumoral collar of spines after treatment with praziquantel and bithionol. This is the first case where L. (Bullastra) cumingiana has been proven to be of medical importance in the Philippines. i.e., as the natural second intermediate host of E. malayanum. The first intermediate host and reservoir host of this parasite in the country are still unknown. Previously, only E. ilocanum was reported to be present in the Philippines.

Animals↗
PubMed1989

Morphology and life cycle of Schistosoma sinensium Pao, 1959, from northwest Thailand.

Schistosoma sinensium Pao, 1959, was first isolated from an unidentified snail in Szechuan Province, China, and was described on the basis of adult worms and eggs recovered from experimentally infected mice. We discovered snails, Tricula bollingi Davis, and rodents, Rattus rattus (L.) and Crocidura attenuata Milne-Edwards, infected with S. sinensium near Fang in northwest Thailand. Adult worms were recovered from small veins immediately adjacent to the small intestine. Eggs first appeared in the feces of experimentally infected mice at 25 days postinfection. Cercariae first emerged from experimentally infected T. bollingi at 40 days postinfection. Shortly after emerging, cercariae were found at the water surface, their bodies flat against the meniscus and tails hanging free in the water column. Our morphometric results for adults and eggs from naturally infected hosts agree well with those presented in the original description. The occurrence of a lateral spine on the egg of this Asian schistosome has created some confusion as to the affinities of S. sinensium. A comparison of 8 character states, including snail hosts, cercarial behavior, geographical distribution, and morphology of life cycle stages, indicates that S. sinensium is more closely related to S. japonicum Katsurada than it is to S. mansoni Sambon.

Animals↗
PubMed1988

Investigation on immunity induced by Schistosoma spindale against S. mekongi in experimental mice.

An investigation on immunity induced by Schistosoma spindale cercariae (cattle and swamp buffalo schistosome) against S. mekongi (human schistosome) was conducted in Swiss albino mice. The studies comprised the development patterns of homologous immunity of S. spindale and heterologous immunity induced by S. spindale against S. mekongi. The development pattern of homologous immunity was studied in mice with an immunization of 100 S. spindale cercariae. At one week intervals, between 2 to 16 weeks after immunization, they were each challenged with 500 S. spindale cercariae. Significant homologous immunity, as judged by lung recovery assay five days after challenge, occurred from week 5 to week 16 with week 8 giving the highest homologous immunity (68.1% of schistosomular reduction). Using the above information mice, with an eight-week immunization period of 100 S. spindale cercariae, were tested for resistance to heterologous S. mekongi infection. The criteria used to evaluate their immune status was schistosomular lung recovery, daily egg output, worm recovery and tissue egg count. The results showed that mice immunized with S. spindale cercariae could develop heterologous immunity against S. mekongi infection. Manifestation of immunity was demonstrated by significant reduction in mean schistosomular recovery (31.4%), in mean daily egg output per female worm (16.7%), in mean worm recovery (64.2%) and in mean egg deposition in the liver tissue and intestines per female worm (37.05%).

Animals↗
PubMed1987

Lung-migration patterns of Schistosoma mekongi and S. spindale in mouse.

Two groups of laboratory-bred Swiss albino mice were used to study the lung-migration patterns of Schistosoma mekongi and S. spindale. The first group was individually infected with 100 S. mekongi cercariae by hair-looping application on shaved abdomen. The latter group was individually exposed to 500 S. spindale cercariae by tail immersion. Each group of these infected mice was then divided into subgroups. The number of schistosomulae was determined using a lung recovery assay starting from the second day after infection and continuing for 15 consecutive days. The results revealed a sharp peak of both S. mekongi and S. spindale on the fifth day post cercarial infection.

Animals↗
PubMed1982

Scanning electron microscope studies of anesthetized Tricula aperta, vector of mekong Schistosoma.

Nembutal, menthol, Ketaset, and Curarine were used to anesthetize beta race of Tricula aperta snails in preparation for study by scanning electron microscopy. The snails remained sensitive to the glutaraldehyde fixative in low level anesthesia of nembutal, menthol and Ketaset. Snails were also sensitive to Curarine and retracted into their shells. The best relaxations were obtained by initial anesthesia with nembutal or menthol followed by curarine. Snails relaxed by this procedure showed relatively little reaction to the fixative solution and remained extended outside their shells. The surface ultrastructure of the snails was well preserved, showing microvillate, secretory, and ciliated sensory cells. The mucoid secretions remained on the surface of cilia on the body and foot of the snails as spherical granules. There were two types of ciliated cells: (1) Those with few short cilia showing 1-3 microns above the microvilli of surrounding cells and (2) Those with numerous cilia up to 10 microns long. Results of transmission electron microscopic studies of these snails show no disruption of the ultrastructure of the surface cells.

Animals↗
PubMed1976

Monograph on "Lithoglyphopsis" aperta, the snail host of Mekong River schistosomiasis.

We discuss the morphology, histology, ecology, distribution, systematics, and evolutionary relationships of "Lithoglyphopsis" aperta Temcharoen, the snail host of Mekong River Schistosoma sp., and part of a vast, complex, endemic hydrobid fauna consisting of 11 genera and over 80 species. "L" aperta is a member of the Hydrobiidae (as broadly outlined by Fretter & Graham, 1962), subfamily Triculinae (as defined by Davis, 1968b). "L" aperta cannot be assigned to Ltihoglyphopsis because its shell and radula differ from those of the type-species, L. modesta (Gredler) from China, and because L. modesta is apparently more closely allied to other Mekong River genera in these traits. The female reproductive system of "L." aperta is similar to that of Tricula burchi Davis, a species from NW Thailand outside the Mekong River drainage. It is not possible to assign aperta to a named genus until the morphologies of numerous other hydrobiid taxa in the Mekong River are unknown. "L." aperta is typically hydrobiid in grade of morphological organization, in the nervous digestive, ctenidial and male reproductive systems. Differences from other hydrobiid taxa are in the female reproductive system and micromorphological features of the digestive tract. "L." aperta and species of Tricula from Thailand have a female reproduction system where sperm enter at the posterior end of the mantle cavity and travel to the bursa copulatrix via a spermathecal duct. These and related traits are the basis for the subfamily Triculinae. Hydrobiid taxa from Europe (Hydrobiinae s.s.) belong in a different phyletic line, where sperm enter the female reproductive system at the anterior end of the mantle cavity and travel via a ciliated groove in the palial oviduct to the bursa copulatrix. "L." aperta, as well as taxa of the Pomatiopsinae (e.g. Oncomelania, Pomatiopsis), differ from most known mesogastropods in lacking a hypobranchial gland. "L." aperta, other triculines, pomatiopsines and hydrobiines, as well as taxa studied in the Bithyniidae, Truncatellidae and Assimineidae differ from other mesogastropods, e.g. Viviparidae, Pleuroceridae, Littorinidae, etc., in that the salivary glands are dorsal to the nerve ring i.e. do not pass through the nerve ring. "L." aperta lives on solid substrata, particularly wood, shells and leaves in the Mekong River from Khemarat, Thailand, to the Cambodian border, 200 river miles downstream. The range probably extends another 100 river miles downstream to Kratie, Cambodia. It is an "r"-selected species by having a high density-independent mortality and using much of its resources for reproduction. The species is a colonizer in a river with severe annual floods. Females live less than 12 months; they apparently lay eggs in late January or February and die. In early March neither adults nor young can be collected. By mid or late March young suddenly flourish. The new generation does not mature until late May or June, after the beginning of the rainy season...

Animals↗
PubMed1975

Mekong schistosomiasis. III: a parasitological survey of domestic water buffalo (Bubalus bubalis) on Khong Island, Laos.

Of 103 water buffalo (Bubalus bubalis) examined on Khong Island by means of the M.I.F.C. and hatching techniques, none were passing eggs resimbling those of the Mekong schistosome. One buffalo calf was infected with Orientobilharzia harinasutai and another with Schistosoma spindale; this is the first time these parasites have been reported from Laos. Since the buffalo that were examined had constant and year-round access to a part of the Mekong River that has been shown to be a site of heavy transmission of schistosomiasis to humans and dogs, it was considered that the buffalo would have acquired the infection with the human Mekong schistosome if this were possible. In the absence of buffalo necropsies, and since no eggs of the Mekong schistosome were detected in the stools of these animals, we assumed that they had either not become infected with this parasite or, if they had, that the infections did not produce eggs in the faeces which were detectable by the methods employed. On the basis of our examinations, it would not seem that domestic water buffalo are involved as reservoirs in the epidemiology of human schistosomiasis on Khong Island.

Animals↗
PubMed1975

Mekong schistosomiasis. 4. A parasitological survey of wild rodents, domestic pigs and cattle on Khong Island, Laos.

No evidence of infection with the Mekong Schistosoma was found in 12 Rattus exulans, 81 R. r. molliculus, and 10 Bandicota savilei caught in the vicinity of and downstream from the schistosomiasis transmission focus on Khong Island, South Laos, and examined by dissection and portal perfusion. Likewise, no eggs of the Mekong Schistosoma were detected in faeces of 15 domestic pigs or 43 domestic cattle examined on Khong Island both by merthiolate-iodine-formalin concentration and by the hatching technique. These results suggested that the wild rodents listed above, as well as pigs and cattle in the vicinity of Khong Town, may not contribute significantly to the transmission of the Mekong Schistosoma under present conditions.

Animals↗