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Y Hashiguchi

Publications and source records attributed to Y Hashiguchi.

At least 109 records · Page 6Linked to original sources
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↗
PubMed1981

The use of aceto-orcein-stained squash preparations for enumeration of nuclei in microfilariae of various filarial parasites.

The nuclear numbers of situated between the cephalic space and the nerve ring (CS-NR) in the microfilariae of six filarial species were examined. For the counting of nuclei, aceto-orcein squashing preparations were used. This procedure revealed nuclei clearly visible under the phase-contrast microscope. The mean number of nuclei in the CS-NR region was very similar between Brugia pahangi and B. malayi, but was statistically different between Onchocerca volvulus and O. gutturosa. In the microfilariae of O. volvulus, two types of nuclei were clearly shown in this region. The procedure described is useful in the anatomical study of microfilariae.

Animals↗
PubMed1981

Limited fly load and development of Onchocerca volvulus microfilariae in Guatemalan Simulium ochraceum.

Fly load of Onchocerca volvulus microfilariae and their early development in Simulium ochraceum were examined at intervals of 10, 30 and 60 min after ingestion and then hourly up to 72 hours. Many microfilariae ingested were damaged by the cibarial armature of the vector, limiting the fly load, but some of these damaged microfilariae were able to penetrate the gut before they died. Thus, the mean number of the living parasites per fly in the head and thorax decreased gradually with elapse of time after ingestion. The parasites ingested by S. ochraceum did not develop beyond the microfilarial stages during the first 24 hours; thereafter only thoracic forms (1st-stage larvae) were found to be alive. The high mortality of the infected fly might be caused by the high intakes of microfilariae and also by normal and/or partly wounded microfilariae invading various organs. The number of microfilaria ingested from different biting sites were usually high in comparison with the densities observed in each site; this indicates that the microfilariae might be attracted by the biting females.

Animals↗
PubMed1980

The distribution of microfilariae in the skin of Guatemalan onchocerciasis patients: an evaluation of diagnostic potentials.

Quantitative examinations for the distribution and density of microfilariae were carried out on male Guatemalan onchocerciasis patients by taking 6 or 13 skin biopsies each from 74 subjects. We found that microfilariae were distributed most frequently on the iliac crest and secondarily in the scapular region; higher detection rates and greater microfilarial densities were seen in these areas. From these results we recommend the taking of biopsies from both of these anatomical regions so as to avoid false negative cases. The infected patients were classified into 3 groups (light, moderate and heavy infections) on the basis of the numbers of negative skin snips out of the 13 biopsies taken. In heavy infections, a higher densities of microfilariae were detected in the head and neck regions, as compared with the densities in the lower extremities (calf). The high concentration of microfilariae in these regions is of importance in relation to the development of eye lesions and/or transmission. Of patients who had microfilariae in the anterior segment of the eye some had negative skin biopsies frm the outer canthus, retroauricular region and neck.

Biopsy↗
PubMed1980

Dermatological survey of onchocerciasis in Guatemala.

A comprehensive survey of onchocerciasis was performed on 1259 inhabitants in San Vicente Pacaya and the surrounding area. The total number of inhabitants examined was 1259, 763 males and 496 females. An examination of microfilarial density was carried out by the skin snip method. There were 610 microfilarial positives (50.4%) out of 1211 persons, 448 males (60.9%), and 162 females (34.1%). Nodules were examined by palpation, and there were 404 (32.8%) positives for nodule out of 1232 persons, 299 males (40.3%), and 105 females (21.4%). Eczematous dermatitis was seen in 149 persons, the generalized type in 13, and other types in 136. Depigmentation on the lower extremities was seen in 290 persons, the severity was graded from 0 to 4, and grade 1 depigmentation was seen in 91; grade 2, in 143; grade 3, in 52 and grade 4 in 4 persons out of 1159 individuals examined. The positives for lymphadenopathy (above grade 2) were 464 (41.2%) out of 1127 individuals. Itching was seen in 129 (18.3%) of 705 individuals examined by the inquiry card method. The correlation between skin changes and onchocerciasis was also analyzed. Those individuals who were microfilarial positive in the skin snip and eyes, and who had palpable nodules were defined as being onchocerciasis patients. There was a high frequency of eczematous dermatitis, depigmentation on the lower extremities and lymphadenopathy in the onchocerciasis infected group, compared with the non-infected group, but there was no difference in the rate of itching between them. Hanging groin, elephantiasis and "erisipela de la costa" were not seen in this endemic area, and the degree of skin changes was slight, compared with that reported in Africa thus far.

Adolescent↗
PubMed1980

Life span and distribution of Onchocerca volvulus microfilariae in mice.

Microfilariae of Onchocerca volvulus obtained from onchocercomas were inoculated subcutaneously into the inguinal region of mice. Microfilariae disseminated rapidly, invading the tail and lungs within 1 hr and the ears within 3 hr postinoculation. During the early period of infection microfilariae appeared in the eyes, ears, viscera, pelt, carcass, and tail; later, the microfilariae tended to accumulate in the tail. Liver microfilariae were recovered up to 12 wk postinoculation. Intraperitoneal inoculation and subcutaneous inoculation into the inguinal region resulted in the concentration of microfilariae in the tail, whereas inoculation into the scalp caused microfilarial accumulation in the ears.

Animals↗
PubMed1979

The use of an Onchocerca volvulus microfilarial antigen skin test in an epidemiological survey of onchocerciasis in Guatemala.

Onchocerca volvulus microfilariae obtained from onchocercal nodules were used as antigenic material for a skin test. This antigen is as specific as those previously employed in skin tests, detecting 85.2% of the persons with positive diagnostic signs of onchocerciasis in endemic areas. A low rate of false positives was found in the control group in nonendemic areas. The positive rate of reactions in the persons without positive signs in the endemic areas might be due to the presences of cases not detected as a result of palpation for nodules and two skin biopsies. In the examination of the residents of several populations, a close correlation was found between the positive rates of skin tests and the presence of infection. From these findings, we conclude that the skin test using the microfilarial antigen is a suitable procedure for the diagnosis of onchocerciasis. The skin test could also be useful as an epidemiological tool in assessing the effectiveness of control programmes.

Adolescent↗