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Biomedical subjects

Y Noguchi

Publications and source records attributed to Y Noguchi.

At least 433 records · Page 24Linked to original sources
PubMed1985

[Studies on coccidiosis in guinea pigs. 1. Clinico-pathological observation].

Clinico-pathological and parasitological studies have been performed on spontaneous and experimental coccidiosis in guinea pigs. Among 11,244 Hartley guinea pigs purchased from suppliers during 1968, 410 (3.6%) of the animals had diarrhea due to coccidiosis. The incidence rate was high in the spring and fall with a mortality rate of 14.4 per cent. A particularly high number of fatal cases were found in the spring. In experimentally induced coccidiosis, clinical signs observed were diarrhea, dehydration, weight loss and death. The diarrhea developed in all animals on the eleventh day after infection and continued for one to five days. Food and water intakes were markedly reduced after the appearance of diarrhea, followed by anorexia and dehydration. Correlating with the appearance of diarrhea was a striking drop in body weight of the guinea pigs. Death usually occurred on the third to fifth day after the onset of diarrhea. The mortality rate was 30 per cent. The major macroscopic findings were characterized by a markedly thickened wall from the ascending to the descending colon and gelatinous edema of the mesenterium of the spiral of the ascending colon. Histologically, there was marked hyperplasia of the mucosal epithelium in the colon and numerous coccidia at different stages of development within the mucus membrane. In the advanced stages of the disease, there was degeneration and desquamation of the epithelia, marked edematous change and infiltration of neutrophil leukocytes and lymphocytes into the lamina propria and submucosa, many oocysts in the lumen of the intestine and in the intestinal glands.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

[Studies on coccidiosis in guinea pigs. 2. Epizootiological survey].

An epizootiological survey has been carried out on naturally occurring coccidiosis in Hartley guinea pigs (weight, 250g) purchased by the National Institute of Health, Tokyo during the period 1964 to 1982. Coccidial infections in breeding colonies of guinea pigs were observed very frequently in weaned animals but scarcely in adult and suckling animals. Oocysts of Eimeria caviae were detected in 53.8% of the 7,162 fecal samples collected from transportation boxes and coccidiosis occurred in 39% of the 1,461 dead or culled animals obtained during the routine one week quarantine period. In the period 1964 to 1971, particularly high rates of prevalence of oocysts, between 55-86%, and incidence of coccidiosis, between 55-76%, were observed. These rates were clearly reduced in the period 1972 to 1982, with a lower rate of isolation of oocysts ranging from 14-48% and les than 20% incidence of coccidiosis (except in 1981 and 1982). The monthly fluctuation of occurrence rates of oocysts and clinical coccidiosis differed over the period of study. From 1964 to 1971, the high prevalence of oocysts was consistently observed accompanied by a bimodal pattern of incidence of coccidiosis in April (85%) and October (78%). In the period 1972 to 1982, both parameters showed a single peak, for prevalence of oocysts in June (60.7%) and for incidence of coccidiosis in May (45%). Oocysts in feces disappeared in February and March and coccidiosis occurred irregularly in 1981 and 1982.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Husbandry↗
PubMed1985

[Occurrence of sick animals in conventional guinea pigs obtained from commercial breeders during 1964 to 1982].

A quarantine was performed on conventional Hartley guinea pigs free from Streptococcus zooepidemicus, Bordetella bronchiseptica and Salmonella spp., but infected with Eimeria caviae, which were purchased from twenty-five commercial breeders by the National Institute of Health. Physical examinations revealed an incidence of 0.88 per cent or 1,461 sick animals in 166, 050 guinea pigs quarantined during the period 1964 to 1982. The result obtained showed the following significant differences between the periods 1964 to 1971 and 1972 to 1982: Annual incidence of sick animals in the period 1972 to 1982 increased twice as many as 0.56 to 0.81 per cent during the 1964 to 1971, and monthly incidence showed bimodal occurrence at April and October in the former period but continual occurrence from November to April in the latter period. Major clinical signs in the former period were death and diarrhea, which occurred usually within a week after arrival of the guinea pigs at our institute and caused significant decrease of body weight, but those in the latter period were retarded growth and weakness which became detectable during 1-3 weeks after arrival of the animals. Discussions were made on possible reasons concerning the differences in incidence of sick animals during the two periods.

Animals↗
PubMed1985

[Brain function in patients with plateau waves studied by compressed spectral array in long-term EEG monitoring].

The intracranial pressure, systemic blood pressure and compressed spectral array in EEG monitoring were studied in three patients with typical plateau waves in continuous intracranial pressure recordings. Two patients with brain-tumor and one patient with aqueductal stenosis were included. The intracranial pressure was recorded through an indwelling ventricular catheter attached to a pressure transducer. The systemic blood pressure was recorded through an intraarterial catheter placed in the femoral artery or the dorsalis pedis artery. To obtain continuous and compressed spectral array in the EEG, Berg-Fourier Analyzer by the OET-Biomedica Company of Italy was used. Simultaneous recordings of the intracranial pressure, systemic blood pressure and EEG spectral analysis were made for 180 minutes in each patient. During the plateau waves, the systemic blood pressure did not rise in spite of a marked increase in intracranial pressure, resulting in a marked decrease in the cerebral perfusion pressure. The patients, however, showed no clinical symptoms resulting from ischemia of the brain, such as vasopressor response and impairment of consciousness, but complained only headache. The spectrograms in these patients were characterized by a constant and predominant activity in the alpha or high frequencies. This structural aspect was retained throughout the continuation of plateau waves. The power of low frequencies only appeared transiently. The results suggest that some mechanisms producing and maintaining the fast and/or alpha wave activity may participate in the recurrent appearance of plateau waves.

Adult↗
PubMed1984

Effect of strychnine on the contractile response of rat vas deferens.

Strychnine at concentrations of 0.1 approximately 1.0 microM induced supersensitivity of rat vas deferens to alpha-agonists but not to other stimulants. Strychnine-treatment resulted in an increase in the number of alpha-adrenoceptors, determined by measuring the binding of [3H]prazosin. Glycine did not have any significant effect on the contracture and did not antagonize the action of strychnine. Thus, specific supersensitivity of alpha-adrenergic system was induced by treatment with low concentrations of strychnine.

Animals↗
PubMed1984

Beta-propiolactone for the inactivation of non-A/non-B type 1 hepatitis virus capable of inducing cytoplasmic tubular ultrastructures in chimpanzees.

Non-A/Non-B type 1 hepatitis virus may be recognized because it induces characteristic tubular ultrastructures in the hepatocyte cytoplasm of chimpanzees. 3 chimps received 0.1 ml of a chimp serum containing more than 100 chimp infecting units of non-A/non-B type 1 hepatitis virus after it had been treated with beta-propiolactone with or without combined ultraviolet irradiation. All of the chimps escaped infection throughout the observation period of 23 weeks. The treatment of the serum with beta-propiolactone at the mildest condition employed (0.05%, 4 degrees C, 20 min) was still effective in inactivating the virus. The susceptibility of the chimps was ascertained by the subsequent challenge with 0.1 ml of the untreated serum which invariably induced non-A/non-B type 1 hepatitis in them. On the basis of these results, beta-propiolactone was extremely efficacious for the cold sterilization of non-A/non-B type 1 hepatitis virus.

Animals↗
PubMed1984

Enhancement of human amniotic phospholipase A2 activity by steroid-sulphate derived from the foeto-placental unit.

To study the control of production of prostaglandins (PG) during pregnancy and parturition, amniotic membranes obtained from normal vaginal delivery were incubated with the substrate of phosphatidylcholine containing [14C]arachidonic acid in the Sn-2 position. Phospholipase A2 activity was calculated as the rate of release of [14C]arachidonic acid from the substrate. Various steroids were added to the incubation medium to elucidate the effect of steroids on the enzymatic activity. The addition of dehydroepiandrosterone-sulphate (DHA-sulphate) to the medium increased by 7-fold the rate of [14C]arachidonic acid release from phosphatidylcholine at a concentration of 1.67 mM. The enhanced rate of arachidonic acid release suggests that DHA-sulphate stimulates phospholipase A2 activity. The same amounts of pregnenolone-sulphate and oestrone-sulphate also enhanced the enzymatic activity, while cholesterol-sulphate, free steroids such as DHA, progesterone, cortisol and oestrogens revealed no effect. These results suggest that steroid sulphates may be involved in the regulatory mechanism for PG synthesis in amniotic membrane.

Amnion↗
PubMed1984

A scene-segmentation method for multispectral cell images.

A scene-segmentation method for two-color digitized images acquired from a Papanicolaou-stained cervical smear is proposed. The method first segments a scene into background, red cytoplasm, blue cytoplasm and nuclear regions by a pixel-wise classification and then merges the segmented regions for both types of cytoplasm into a single region. To create the minimum-distance classifier used for the pixel classification, class median vectors are selected from a two-dimensional histogram formed from the optical densities in the red and green images (scanned at 610 nm and 535 nm, respectively). Reference points defined from knowledge about the two-color images played an important role in selecting the vectors for the red and blue cytoplasm. This method was applied to 33 sets of the two-color images. The resulting segmented regions corresponded well with regions apparent to the the human observer. Three different investigations related to the method were carried out; these studies confirmed the suitability of the proposed method.

Cell Nucleus↗