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Biomedical subjects

Y Hashiguchi

Publications and source records attributed to Y Hashiguchi.

At least 91 records · Page 5Linked to original sources
PubMed1988

The effect of cyclosporin A on the course of Paragonimus miyazakii infection in rats.

The effect of the immunomodulatory fungal metabolite cyclosporin A (CyA) on the course of Paragonimus miyazakii infection in rats was studied. Administration of CyA 15 to 19 days post-infection resulted in a significantly lower recovery rate of worms and cyst formation in the host's lungs than in controls. Administration of CyA -1 to +3 days post-infection enhanced the growth and maturation of P. miyazakii, expressed as weight of worms and the number of worms with eggs in uteri with respect to control values. This study shows that administration of CyA to rats affects the host-parasite relationship, depending on the time of administration of the drug.

Animals↗
PubMed1987

Association of electrocardiographic abnormalities with seropositivity to Trypanosoma cruzi in Ecuador.

In highland Ecuador (province of El Oro), electrocardiograms (ECGs) were taken and analysed from 340 subjects, of whom 154 were seropositive to Trypanosoma cruzi by indirect haemagglutination test. Abnormal ECGs were present in 40.3% of seropositive individuals and 8.1% of seronegatives, and were slightly more common in seropositive males than in seropositive females. In seropositive individuals, the prevalence of abnormal ECG progressively increased with age and reached its peak level of 64.0% in the age group over 60 years, implying that Chagas disease in Ecuador produces little mortality among seropositive individuals. The most common ECG alterations were ventricular conduction defects: 26 of 117 seropositive individuals in the age group over 40 years had complete right bundle branch block. The frequency of atrioventricular block and arrhythmias was also associated with seropositivity to T. cruzi. A further ECG examination in lowland (province of Guayas) showed that the prevalence of abnormal ECGs there was significantly lower than that in highlands. These results suggest possible differences between T. cruzi strains in the two geographical areas of Ecuador.

Adolescent↗
PubMed1987

The relationship between severity of ulcerated lesions and immune responses in the early stage of cutaneous leishmaniasis in Ecuador.

The relationship was examined between the severity of ulcerated lesions and immune responses in 19 Ecuadorian patients in the early stages of New World cutaneous leishmaniasis. As an immunological assay, the humoral immune response was assessed by enzyme-linked immunosorbent assay (ELISA) and the cell-mediated response by delayed type skin test for leishmanial antigen (leishmanin test). There was a statistically significant correlation (r = 0.61, P less than 0.01) between the total area of ulcerated lesions and the reciprocal titre of ELISA in identical subjects. However, no significant difference was observed in the ELISA titre between patients with a single lesion and those with multiple lesions (chi 2 = 7.06, df = 5, P greater than 0.2). A correlation (r = 0.48, P less than 0.05) was observed between the area of lesions and the intensity of leishmanin test; further, the ELISA titre also correlated to the intensity of leishmanin test in the identical subjects (r = 0.71, P less than 0.01). These results suggest that the severity of ulcerated lesions relates to the activation of both the humoral and cell-mediated immune systems in the early stage of New World cutaneous leishmaniasis.

Adolescent↗
PubMed1985

Biting activity of two anthropophilic species of sandflies, Lutzomyia, in an endemic area of leishmaniasis in Ecuador.

The biting patterns of Lutzomyia trapidoi and Lu. hartmanni, vectors of leishmaniasis, were studied using a human bait in an endemic area on the Pacific slope of the Andes in Ecuador. The results suggest that Lu. trapidoi is primarily an early biter at dusk, with the first peak at 20.00-21.00 hours and the second at 03.00-04.00 hours; and that Lu. hartmanni bites more constantly throughout the night, with a pronounced peak between 23.00 and 24.00 hours. The biting activity, however, shows a marked variation at each site and between different collections at the same site. The activity and the biting places on man are discussed in relation to human infection with leishmaniasis in the area and the location of lesions on patients.

Animals↗
PubMed1985

Natural infections with promastigotes in man-biting species of sand flies in leishmaniasis-endemic areas of Ecuador.

In order to determine the vectors of leishmaniasis in Ecuador, 1,054 man biting sand flies from the Department of Cañar were dissected and examined for promastigotes. There were 2 man-biting species, Lu. trapidoi and Lu. hartmanni in this endemic area of the disease. The infection rates were 7.7% in the former and 3.9% in the latter species, demonstrating the different rates in various localities and altitudes of the study areas. There was an association between infection rates and the time of day, suggesting some connection with biting activity of sand fly species. In collections using human bait at 7 study areas in 5 Departments, 6 man-biting species were recognized, indicating different dominant species in each area. It was assumed that the dominant species would play an important role as the principal vector of leishmaniasis in each endemic area. As to species determination of the present Leishmania promastigotes, suffice it to say that the parasites are Leishmania sp., presumably L. braziliensis s.l., until the isolates have been typed.

Animals↗
PubMed1983

Primary isolation of cytopathic bovine rotaviruses on fetal rhesus monkey kidney cells.

Primary isolation of bovine rotaviruses was successfully performed on rolling cultures of MA104 cells following trypsin treatment of fecal samples and cells. Fifty-one fecal samples were obtained from 22 herds affected with naturally-occurring acute diarrhea in calves during a period of over two years. Rotavirus particles were demonstrated in only 10 fecal samples by electron microscopy. Fourteen cytopathic bovine rotaviruses were isolated from positive samples and could be serially cultivated on MA104 cells. The presence of virus was identified by specific immunofluorescence in infected cells. These data indicated that approximately 30% of the herds affected with acute diarrhea in their calves were associated with rotavirus infection.

Animals↗
PubMed1983

Serotypes of bovine rotaviruses distinguished by serum neutralization.

Fourteen cytopathic bovine rotaviruses isolated from naturally affected calves were characterized serologically by serum neutralization. Antisera were prepared in guinea pigs against the three isolates and the Lincoln strain of bovine rotavirus. These four rotaviruses were segregated into at least two distinct serotypes (designated types 1 and 2) by serum neutralization. The remaining 11 isolates were also placed into two groups according to neutralization specificity by using the antisera against types 1 and 2 bovine rotavirus. When colostrum-deprived calves were experimentally inoculated with type 1 or 2 bovine rotavirus, respectively, the calves produced neutralizing antibodies against the inoculated serotype but not against the other serotype. Calf sera obtained from six herds with naturally occurring rotavirus infections possessed neutralizing antibodies against type 1 or 2 or both. Thus, distinct serotypes of bovine rotavirus were demonstrated by serum neutralization. The possible role of serotypes in the epidemiology of rotavirus infection among bovine species is discussed.

Animals↗
PubMed1982

Prevalence and incidence of onchocerciasis as baseline data for evaluation of vector control in San Vicente Pacaya, Guatemala.

The aim of this study was to estimate the incidence rate of onchocerciasis as measured by skin biopsy during field surveys carried out in San Vicente Pacaya, Guatemala from 1977 through 1979. The age standardized prevalence rates for males and females were 44.6% and 19.9%, respectively, in 1979. There were annual incidence rates of 0.08 and 0.04 for males and females, respectively. The incidence rates seem to increase with age. Since the effect of false negatives will be greater in females than in males, these rates should be interpreted cautiously. Extremely high reversion rates (proportion of negatives in a later examination among positives at the first examination by skin biopsy) were observed; these figures might be explained mainly by false negatives due to the skin biopsy. However, it is suspected that some of the apparent reversion rates may also have been influenced by other factors, e.g., sex difference.

Adolescent↗
PubMed1982

Simple, direct measurement of lipoprotein X in serum.

This relatively simple method for quantitative estimation of lipoprotein X is based on assay of phospholipids in precipitates of lipoprotein X. We first remove other lipoproteins by precipitation with phosphotungstic acid solution. Lipoprotein X is then precipitated from the supernatant fluid with an alkaline solution of magnesium ion, and phospholipid is determined in this precipitate. Results are linearly related to concentration of lipoprotein X. The CV is less than 3%. Results correlated well with those for agar gel electrophoresis.

Cholestasis↗
PubMed1981

Seasonal variation in the microfilarial skin density of Onchocerca volvulus and in the biting activity of Simulium spp. in Guatemala.

The density of Onchocerca volvulus microfilariae in the skin of 11 carriers was examined by carrying out a monthly examination in a single endemic area of Guatemalan onchocerciasis. The results obtained suggested the possibility of a seasonal variation in the microfilarial skin density. Almost all of the volunteers participating had shown a peak concentration of microfilariae in September, followed by August or October. The highest biting densities of Simulium ochraceum, the principal vector of onchocerciasis in Guatemala, occurred from September to the following January. It thus appears that the seasonal variation in the microfilarial density may correspond, to some extent, with the biting activity of the vector, S. ochraceum and/or with climatic changes in the area.

Adolescent↗