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Biomedical subjects

I Murakami

Publications and source records attributed to I Murakami.

At least 109 records · Page 6Linked to original sources
PubMed1984

Effects of gastrectomy on insulin secretion in rats.

To examine the relative importance of the stomach for the enteroinsular axis, the portal insulin secretion was measured in the rats with gastrectomy, after intraduodenal (I.D.) infusion of 0.5 g/kg glucose and after intravenous (I.V.) infusion of the same deal of glucose, respectively. Portal plasma gastrin was decreased from 100 pg/ml to 5 pg/ml by gastrectomy. Blood sugar level after I.D. and I.V. infusion of glucose in the rats with gastrectomy was similar to controls. Insulin release to I.D. infusion of glucose was slightly lower at 30 minutes in the gastrectomized rats compared with controls, while insulin secretion to I.V. infusion of glucose was similar to controls. These results suggest that endogenous gastrin has no insulinotropic effect and that the stomach has no direct effect on glucose-induced insulin release.

Animals↗
PubMed1981

Inoculation of dengue virus into nude mice.

When athymic nude (nu/nu) and heterozygous littermate (nu/+) mice were injected intraperitoneally (i.p.) with a mouse-adapted strain of dengue virus (DV), the following differences were noted in the course of infection. (i) The average survival time of nu/nu mice was longer than that of nu/+ mice, although the mortality ratios were not significantly different. (ii) DV persisted in some of the nu/nu mice for long periods of time without exhibiting any symptoms but they died after prolonged incubation periods. These aspects were not observed in the nu/+ mice. (iii) Infected nu/nu mice produced IgM antibody only transiently in the early stage of infection but they did not subsequently show regular IgG antibody production which normally occurred in nu/+ mice. (iv) Piamatral and perivascular mononuclear cell infiltration in the infected brain was more intense in nu/+ than in nu/nu mice. It is suggested from these data that the course of DV infection in mice is affected by the availability of thymus-derived lymphocytes (T-cells). Infectious virus was detected in various organs and tissues of infected mice. The hearts of nu/nu mice tended to show higher virus titres than those of nu/+ mice, whereas the virus concentrations in the brain, skeletal muscle and lymph node were the same in both groups of mice. Specific DV antigen was revealed by the fluorescent antibody (FA) technique in cells located in the infected tissues.

Animals↗
PubMed1981

Sputum cytology of a metastatic postradiation sarcoma (malignant fibrous histiocytoma).

A female patient who died of apparent postradiation sarcoma in the inguinal region after irradiating a metastatic squamous cell carcinoma of the same site was reported. For approximately 20 months, the patient had received a total of 6,600 and 9,600 Roentgen to the right para-aortic and inguinal areas, respectively. About 10 years later, she developed a sarcoma, namely a malignant fibrous histiocytoma. Sputum cytology demonstrated numerous giant cells with bizarre nuclei; subsequent chest films also presented apparent metastatic tumor shadows. The cellular characteristics and also rather low incidence of detection of nonepithelial malignant tumor by sputum cytology were briefly discussed, and ways of enhancing cytodiagnostic accuracy were proposed.

Adult↗
PubMedDate not supplied

Intraperitoneal seeding of ruptured hepatocellular carcinoma: case report.

We report a solitary intraperitoneal recurrence in a long-term survivor after rupture of hepatocellular carcinoma. Ultrasonography demonstrated the finding of a lobulated mass with a "mosaic" appearance. The patient underwent resection of this implant and is currently disease free. We emphasize the importance of periodic surveillance of disseminated metastases of this condition.

Aged↗
PubMedDate not supplied

Behavioral evidence of filling-in at the blind spot of the monkey.

In human subjects, the blind spot is perceptually filled-in by color and brightness from the surrounding visual field. The present behavioral study examined the occurrence of color filling-in at the blind spot in monkeys. First, the location of the blind spot was determined using a monocular saccade task. The blind spots were located on the horizontal meridian at approximately 15-17 deg from the fixation point in the temporal visual field. Then, filling-in at the blind spot was tested by determining if the monkey could discriminate between an annulus presented on the blind spot and a homogeneous disk in the normal visual field. In this task, the monkey was required to make a saccade to a homogeneous disk of the same color and size as an annulus presented simultaneously in the opposite field. Both stimuli were large enough to cover the blind spot and the inner circle of the annulus was confined inside the blind spot. All four monkeys tested performed this task correctly in over 80% of the trials. However, when one eye was covered and the annulus was presented on the blind spot of the uncovered eye, performance deteriorated significantly. To confirm that these results reflected filling-in, one monkey was trained to maintain fixation when two identical homogeneous disks appeared in opposite visual fields. When only one eye was uncovered, and the annulus was presented on the blind spot of the uncovered eye, the monkey maintained fixation in most of the trials. These results show that monkeys were unable to distinguish an annulus from a homogeneous disk when the annulus was presented on the blind spot. This indicates that color filling-in occurs at the blind spot in monkeys and opens possibility to physiological experiments to study the neural mechanisms of filling-in.

Animals↗
PubMedDate not supplied

Perceptual filling-in at the scotoma following a monocular retinal lesion in the monkey.

Although no visual inputs arise from the blind spot, the same visual attribute there as in the visual field surrounding the blind spot is perceived. Because of this remarkable "perceptual filling-in," a hole corresponding to the blind spot is not perceived, even when one eye is closed. Does the same phenomenon occur in the case of a scotoma in which visual inputs are lost postnatally due to a retinal lesion? We report that it did: in the macaque monkey, behavioral evidence for filling-in at a scotoma produced by a laser-induced monocular retinal lesion was obtained. The visual receptive fields of neurons in the primary visual cortex (V1) in and around the representation of the visual field corresponding to the scotoma were also mapped, and no clear difference between the retinotopic organization of this part in V1 and that found in the normal visual field was found. Also, perceptual filling-in was found to occur only two days after the lesion. These findings suggest that the normal visual system possesses a mechanism that yields filling-in when some part of the retina is damaged, and that such a mechanism requires no topographical reorganization in V1.

Animals↗
PubMedDate not supplied

Does amniotomy influence the prognosis of babies in cases with severe chorioamnionitis? Report of a twin pregnancy with varying outcome.

We report our experience in a woman with a twin pregnancy. The patient suffered severe Escherichia coli chorioamnionitis and the outcomes were different between the two babies after birth. The first baby had only a mild infection, but the second suffered sepsis and subsequent perinatal death. These differences in outcome appeared to be due to amniotomy performed for the first baby after late labor stage I to augment uterus contractions. Removal of infectious amniotic fluid from the amniotic cavity might thus have prevented the spread of the chorioamnionitis. E. coli sometimes causes severe infection during pregnancy and the perinatal period. In this case, a large number of enteropathogenic E. coli (serotype O-6) was cultured from blood, stool, pharyngeal swab, gastric juice and puncture fluid from the thoracic cavity of the second baby. O-6 is classified an enterotoxigenic strain mainly causing diarrhea because of endotoxin released from bacteria. O-6 has not hitherto been reported as a cause of severe infection in chorioamnionitis and perinatal sepsis.

Adult↗