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Biomedical subjects

T R Klei

Publications and source records attributed to T R Klei.

At least 109 records · Page 6Linked to original sources
PubMed1987

Induction of lymphatic lesions by Brugia pahangi in jirds with large and small preexisting homologous intraperitoneal infections.

The effect of intraperitoneal (i.p.) infections induced by inoculations of 30 or 150 Brugia pahangi third-stage larvae (L3) on the development of infections and lymphatic lesions induced by subsequent homologous subcutaneous (s.c.) inoculations were compared in the present study. Lymphatic lesion severity, as judged by the numbers of lymph thrombi present, and lymphatic lesion scores were significantly reduced in both groups of jirds with existing i.p. infections. The numbers of adult worms that developed, locations of these worms, and the subsequent microfilaremias did not differ significantly between groups. All jirds with i.p. infections developed similar antibody titers to crude somatic adult antigen as measured by ELISA. These levels did not change following s.c. infections. Immediate and delayed footpad swelling responses were also similar in all groups. Results of these experiments support and extend previous studies indicating that i.p. infections of B. pahangi induce a hyporesponsive state in jirds to subsequent s.c. infections without significantly affecting the subsequent parasite burden. This effect appears to be independent of the numbers of L3 inoculated i.p. prior to lymphatic-induced infection. Circulating antibody titers and footpad swelling responses to B. pahangi antigen were not reduced in jirds with the hyporesponsive lymphatic inflammatory response and do not correlate with this condition.

Animals↗
PubMed1987

Seasonal changes in density and tissue distribution of Onchocerca cervicalis microfilariae in ponies and related changes in Culicoides variipennis populations in Louisiana.

Seasonal changes in density and spatial distribution of Onchocerca cervicalis microfilariae were studied in ventral-midline skin of 15 infected pony mares in southern Louisiana. Triple running mean analysis of data over a 13-mo period indicated that a distinct pattern exists in total microfilariae population density and in microfilariae occurrence in different levels of the dermis. Microfilariae density reaches peak levels in the spring followed by a 58% decrease in the summer, a 19% increase in the fall, and a decrease to the lowest numbers in the winter. Microfilariae were found in all levels of the skin during the spring, summer, and fall but were not found in the superficial layers of the dermis during the winter months. The population density of Culicoides variipennis, a demonstrated vector of O. cervicalis, appeared to have seasonal fluctuations similar to the changes in microfilarial density. Harmonic wave analysis of microfilariae density data in individual ponies showed that all individuals did not follow the population trend.

Animals↗
PubMed1986

Development of Brugia pahangi infections and lymphatic lesions in male offspring of female jirds with homologous infections.

The development of Brugia pahangi infections and associated gross lymphatic lesions were compared in male offspring from B. pahangi-infected and uninfected female jirds. The numbers of adult worms recovered did not differ between groups but a greater number of offspring of infected females (92%) developed circulating microfilaraemias than did individuals from uninfected females (50%). Intralymphatic granulomatous thrombi, lymphatic dilatations and lymphatic lesion scores were significantly reduced in offspring from infected mothers.

Animals↗
PubMed1986

Other parasites. Recent advances.

This article briefly reviews new information on trichostrongylid stomach worms, spirurid stomach worms, tapeworms, threadworms, pinworms, intestinal protozoa, lungworms, eye worms, and numerous other aberrant parasites as it relates to prevalence, pathogenesis of diseases, and treatments.

Animals↗
PubMed1986

Laboratory diagnosis.

Diagnosis of internal parasitism is based on many factors, including clinical signs, case histories of individual animals and the herds of which they are a part, and, finally, specific laboratory findings. Laboratory methods used can be divided into those associated with the qualitative and quantitative examination of feces for parasite eggs, larvae, and oocysts, and laboratory findings on changes in physiologic status of individuals that may be produced by specific parasites.

Animals↗
PubMed1986

Immunity and potential of vaccination.

This article will focus on current information available on the equine immune response to helminth parasites as it relates to acquired resistance, hypersensitivity reactions, and vaccine development.

Animals↗
PubMed1986

A survey in Louisiana of intestinal helminths of ponies with little exposure to anthelmintics.

Ponies reared with minimal or no exposure to anthelmintics were surveyed for intestinal helminths in order to estimate prevalence and intensity of parasite populations unaltered by frequent exposure to anthelmintics. Thirty-seven mixed breed ponies of varying ages were examined. Thirty-four species of nematodes and 2 species of cestodes were found. Twenty-four of the nematode species (including 1 new species) were in the subfamily Cyathostominae (small strongyles). Eighty-seven percent of the total burden of adult small strongyles in the large intestine was composed of 10 species. By comparing the results of the present survey with those of recent surveys of horses from herds which had been subjected to treatments with anthelmintics, the effect of prolonged usage of anthelmintic treatment on the prevalence of individual species possibly can be estimated. The general ranking of the 10 most common cyathostome species was similar to those described in recent surveys of horses, suggesting that anthelmintic pressure does not affect the prevalence of most cyathostome species. The lack of anthelmintic treatment appeared not to affect prevalence rates for Anoplocephala perfoliata and Anoplocephala magna when compared to other studies. Conversely, prevalence rates for Strongylus spp., Triodontophorus spp., Craterostomum acuticaudatum, Oxyuris equi, and Parascaris equorum were higher than those reported for these species in recent studies of horses.

Animals↗
PubMed1985

Prevalence of trichinosis in southern Louisiana swine.

After an outbreak of human trichinosis in Louisiana involving 45 cases and 1 death in 1979 and 1980, a survey of pigs killed in 21 selected small slaughterhouses in southwestern Louisiana was conducted from November 1980 to September 1981. The sera from 1,225 pigs were examined for trichinella antibodies using an enzyme-linked immunosorbent assay (ELISA); 1,223 diaphragms were subjected to peptic digestion and examined for the presence of Trichinella spiralis larvae. One diaphragm (0.08%) was found to contain T spiralis (26 larvae/g of muscle) and 4 of the slaughterhouse sera were positive (0.33% seroprevalence). Pigs in 52 herds throughout the state were also tested for ELISA antibodies. The ELISA-positive pigs were not found among the 267 pigs tested from the 52 herds.

Abattoirs↗
PubMed1985

In vitro development of Strongylus edentatus to the fourth larval stage with notes on Strongylus vulgaris and Strongylus equinus.

Strongylus edentatus was successfully cultured in vitro to the fourth larval stage (L4). Some growth continued for periods of 40-50 days at which time reductions in viability were observed in some of the culture systems tested. Various combinations of media, sera, buffers and organ explant cultures were tested. All cultures were incubated at 37 C in an atmosphere of 95% air and 5% CO2. Larvae underwent growth and differentiation to the L4 in all medium-serum combinations with and without organ explant cultures. Development and growth did occur but viability was reduced to insignificant levels in media without serum or cells. Optimal growth, differentiation, and longevity were observed in bicarbonate buffered RPMI-1640 containing 10% fetal calf serum and gerbil (Meriones unguiculatus) cecum explant cultures. Observations indicated that Strongylus vulgaris and Strongylus equinus also developed to the L4 stage using similar techniques. However, viability of S. vulgaris L4 was markedly limited. Specific morphological changes marked phases of development of S. edentatus, categorized as early, middle and late third stage, third molt and early fourth stage. Strongylus equinus appeared to follow the same developmental pattern in vitro as S. edentatus. Distinct differences in morphological features during differentiation were observed between S. edentatus and S. vulgaris.

Animals↗
PubMed1984

Activation of jird (Meriones unguiculatus) macrophages by the filarial parasite Brugia pahangi.

Peritoneal macrophages from Mongolian jirds (Meriones unguiculatus) with either lymphatic or intraperitoneal infections of Brugia pahangi were studied to determine the effects of infection on macrophage function and morphology. Macrophages were collected at 40, 90, 140, and 200 days after inoculation of infective third-stage larvae and assayed for phagocytic and bactericidal activity by the acridine orange method and for morphological changes by light and electron microscopy. Significant increases in phagocytic and microbicidal activity (P less than or equal to 0.01) were observed in peritoneal macrophages collected from jirds with intraperitoneal infections when compared with peritoneal macrophages from jirds with lymphatic infections and resident peritoneal macrophages from normal, noninfected jirds. Morphological changes in peritoneal macrophages from jirds with intraperitoneal infections were similar to those found in thioglycolate-elicited macrophage populations. Granuloma formation was also observed in the peritoneal cavities of intraperitoneally infected jirds. The peritoneal cavity may serve as a model to study cell-worm interactions in filarial nematode infections.

Animals↗
PubMed1984

Effect of ivermectin treatment on eosinophilic pneumonia and other extravascular lesions of late Strongylus vulgaris larval migration in foals.

Eighteen parasite-free pony foals were infected orally with 500 third stage larvae of Strongylus vulgaris. At 56 days after infection, six ponies were treated with intramuscular ivermectin (22, 23-dihydroavermectin B1); six were treated with oral ivermectin; and six were not treated. Necropsy was done 91 days after infection to study the pathologic effects of migrating S. vulgaris larvae and to determine the efficacy of ivermectin in attenuation of S. vulgaris-induced lesions. Larval migration induced eosinophilic inflammation of the liver, spleen, mesenteric, colic and cecal lymph nodes, and small and large intestine. Previously unreported parasitic lesions included eosinophilic pneumonia with eosinophilic granulomas and pulmonary lymphoid nodules. S. vulgaris larvae were observed in eosinophilic granulomas in the lung, epicardium, liver, and intestinal serosa. Injectable and oral ivermectin formulations were equally effective in reduction of these lesions.

Animals↗
PubMed1984

Prevalence of Onchocerca cervicalis in equids in the Gulf Coast region.

Microfilariae of Onchocerca cervicalis were detected in midventral skin biopsy samples in 64 of 84 (76%) mixed-breed ponies greater than 2 years old from the Gulf Coast area and in 42 of 51 (82.4%) horses from Louisiana breeding herds. The number of microfilariae per 8 mm of biopsied skin (ponies) ranged from 1 to 21,570. The number of microfilariae per 6 mm of biopsied skin (horses) ranged from 8 to 55,600.

Animals↗
PubMed1984

Efficacy of ivermectin in injectable and oral paste formulations against eight-week-old Strongylus vulgaris larvae in ponies.

A controlled test method was used to evaluate the efficacy of injectable micelle and oral paste formulations of ivermectin (22,23-dihydroavermectin B1) against 8-week-old Strongylus vulgaris larvae in experimentally infected pony foals. The dosage level of the drug in both formulations tested was 0.2 mg/kg. Ponies were euthanatized and necropsied 5 weeks after treatment. Based on the recovery of live vs dead S vulgaris from mesenteric arteries, both formulations were greater than 99% effective. Increased weight gains and marked reductions in the severity of arterial lesions were observed in treated ponies.

Administration, Oral↗
PubMed1983

Antibody responses of ponies to initial and challenge infections of Strongylus vulgaris.

An indirect fluorescent antibody assay (IFA) was developed using Strongylus vulgaris third stage larvae (L3) as antigens. Observations using the IFA indicate that a species-specific antibody response to S. vulgaris L3 develops in S. vulgaris-infected ponies and that some surface L3 antigens are shared by adult worms. Sequential antibody levels against S. vulgaris were measured in strongyle-naive and in immune ponies following initial and challenge infections using the IFA and an indirect hemagglutination assay (IHA). Antibody levels measured by IFA increased faster following initial infections than did levels measured by IHA. Antibody levels appear to increase following challenge infections of immune ponies when measured with the IFA, but not with the IHA. Significant differences in antibody titers were not seen between ponies which developed colic following challenge infections and those that did not develop colic. Antibodies were not detectable in ponies unexposed to larval migrations, but which received surgical implantation of S. vulgaris adults into the cecum.

Animals↗
PubMed1982

Effects of presensitization on the development of lymphatic lesions in Brugia pahangi-infected jirds.

Experiments were conducted to measure the degree of lymphatic pathology which develops in mongolian jirds (Meriones unguiculatus) sensitized to Brugia pahangi antigens prior to subcutaneous infections. Two protocols were used to sensitize jirds. One group of animals received three intravenous (IV) inoculations of 5,000 frozen, washed, B. pahangi-microfilariae at 10-day intervals. A second group received three inoculations of 150 micrograms of soluble somatic adult B. pahangi antigen (Ag) in Freund's complete adjuvant (FCA) at 10-day intervals. Groups of animals receiving saline in FCA and animals receiving no treatment served as controls. Following immunizations, animals from each group were tested for circulating antibody by the indirect hemagglutination assay, and for immediate and delayed hypersensitivity responses by the footpad swelling assay. All sensitized animals tested showed positive reaction to these assays. Observations at necropsy 90 days after inoculation with infective larvae showed that: 1) the percent recoveries of adult worms were the same in all treatment groups; 2) the numbers of patent infections which developed in the Ag in FCA-treated animals was greatly reduced; 3) level of microfilaremia which developed in animals sensitized with microfilariae was markedly lower; and 4) the degree of lymphatic pathology as judged by lesion score, numbers of intralymphatic thrombi, and lymphatic vessel size was significantly greater in presensitized animals than in nonsensitized infected controls. The increased lymphatic pathology seen in presensitized animals was most marked in jirds with occult infections and high antibody titers. These observations indicated that the B. pahangi-jird model is a useful semiquantitative system for the study of filarial-associated lymphatic pathology and strongly supports the hypothesis that the host immune response is involved in the pathogenesis of lymphatic filariasis.

Animals↗