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Biomedical subjects

Y Nishimura

Publications and source records attributed to Y Nishimura.

At least 973 records · Page 54Linked to original sources
PubMed1987

The patient with combined deficiency of neuraminidase and 21-hydroxylase.

To investigate the possibility that deletion en block in the HLA region had caused the combined deficiency of neuraminidase and 21-hydroxylase in a female patient, genetic markers on the short arm of chromosome 6 were examined in the patient and her parents, and 21-hydroxylase genes of the patient were analyzed by the Southern blot technique. The affected "extended haplotype" identical by descent might have been recombined at two sites, between HLA-A and C and between HLA-DQ and GLO. This suggests that the neuraminidase gene is mapped between HLA-A and GLO. Southern blot analysis revealed the existence of two 21-hydroxylase genes, so that we found no evidence to support the possibility that deletion en bloc in the HLA class III region had caused the combined deficiency of neuraminidase and 21-hydroxylase.

Adrenal Hyperplasia, Congenital↗
PubMed1987

Regional hyperthermia combined with blockade of the hepatic arterial blood flow by degradable starch microspheres in pigs.

The benefit of hepatic arterial microembolization by degradable starch microspheres (DSM) was investigated in regional hyperthermia of the liver. Hyperthermia with and without blood flow blockade of the hepatic artery using degradable starch microspheres was performed on six pigs. Heat was given for 30 min in each treatment by 8 MHz radiofrequency capacitive heating equipment. To maintain blood flow blockade during hyperthermia, 10 mg/kg of degradable starch microspheres was administered into the hepatic artery as an initial dose and 5 mg/kg of the drug was added periodically under the measurement of hepatic arterial blood flow by an electromagnetic flowmeter. To evaluate the effect of degradable starch microspheres, the temperature increase in the liver and rectum was compared between the treatment with and without DSM. All pigs showed a larger increase in intrahepatic temperature when heated in combination with degradable starch microspheres than without. On the other hand, temperature increase in the rectum as a result of hyperthermia to the liver was suppressed by DSM as compared with hyperthermia alone. These results indicate that hepatic arterial embolization by degradable starch microspheres potentiates radiofrequency capacitive heating of the liver. Although this study was not made with liver tumors, regional hyperthermia may be effective in the control of liver tumors when heat is given after the blockade of the hepatic artery by DSM.

Animals↗
PubMed1987

Pyridonecarboxylic acids as antibacterial agents. 9. Synthesis and antibacterial activity of 1-substituted 6-fluoro-1,4-dihydro-4-oxo-7-(4-pyridyl)-1,8-naphthyridine-3- carboxylic acids.

The title compounds (7a-e) with ethyl, 2-fluoroethyl, 2-hydroxyethyl, vinyl, or cyclopropyl groups, respectively, at C-1 were prepared by the method involving the Balz-Schiemann reaction of 2-(4-pyridyl)pyridine- and 7-(4-pyridyl)-1,8-naphthyridinediazonium tetrafluoroborates (15 and 27). The 1-ethyl, 1-(2-fluoroethyl), and 1-vinyl derivatives showed in vitro activities as potent as the corresponding 7-(1-piperazinyl) analogues against Staphylococcus aureus 209P JC-1 and Escherichia coli NIHJ JC-2 but were less active against Pseudomonas aeruginosa 12. Among the 7-(4-pyridyl) derivatives having the different C-1 substituent, 1-cyclopropyl derivative 7e was found to be the most active. In vivo efficacy of 7e was superior to that of enoxacin against experimental infections due to S. aureus 50774. Some aspects of structure-activity relationships associated with the C-1, C-6, and C-7 substituents were discussed.

Animals↗
PubMed1987

Inhibitory effect of pentobarbital on phospholipase C activity in ischaemic rat brain.

Ischaemic rat brains were examined for temporal changes in phospholipase C activity with phosphatidylinositol; the effects of pentobarbital on the activity also were investigated. Ischaemia was produced by decapitation. Pentobarbital (60 mg/kg) was administered i.p. for 15 min before decapitation. The removed heads were incubated at 37 degrees C for 1, 5, 15 or 30 min and then quickly frozen in liquid nitrogen. After isolation of subcellular fractions from the brains, phospholipase C activity was measured for cytosol and microsomes, using radioactive phosphatidylinositol as a substrate. The results demonstrated that brain phospholipase C predominantly localized in the cytosol was dependent on Ca2+ for full activity and had neutral pH optima. Although the enzyme activity did not increase during ischaemia, pentobarbital inhibited phospholipase C activity in the cytosol but not in the microsomes. These observations suggest that pentobarbital may exert a cerebral protective action due to, at least in part, the repression of phospholipase C followed by a reduction of phosphatidylinositol breakdown, preventing perturbation to the integrity of membranes, during ischaemia.

Animals↗
PubMed1987

Tumor response to thermoradiation therapy: use of CT in evaluation.

Seventy-two tumors, mostly in deep locations, were studied retrospectively with computed tomography (CT) before and after thermoradiation therapy. Hyperthermia was administered locally or regionally with radio frequency capacitive heating equipment after irradiation (total dose, 20-70.2 Gy) for 40-60 minutes per session in a total of four to 13 sessions. Sixteen of the 72 tumors showed complete regression. Tumor regression was not related to the average maximum or minimum tumor temperature. CT scans obtained after thermoradiation therapy demonstrated a clear low-density area in 32 of 56 tumors that did not regress completely. Histopathologic examinations, performed in 14 of the 32 tumors, showed the low-density area to be massive coagulation necrosis. The low-density area was classified into three types according to its percentage area in the tumor: type 3 (more than 80%), type 2 (50%-80%), and type 1 (less than 50%). The type correlated with the average maximum and minimum tumor temperature, and follow-up observations and histopathologic examinations showed great effects in most of the type 3 tumors.

Adult↗
PubMed1987

Cerebral hemorrhage in patients on maintenance hemodialysis. CT analysis of 25 cases.

Site of hematoma and clinical outcome in cerebral hemorrhage were analyzed in 25 maintenance hemodialysis (HD) patients and compared with those in 27 non-HD patients. Ganglionic-thalamic hemorrhage was found in 56% of HD and 74% of non-HD patients, lobar hemorrhage in 36% and 11%, respectively. Size of hematoma, expressed as a ratio (%) of hematoma area to entire brain on CT slice, was 6.5 +/- 4.2% (mean +/- SD) in HD, being significantly larger than that of 4.7 +/- 3.5% in non-HD patients (p less than 0.05). Mortality rate was 60% in HD patients, nearly twice as much as the 33% in non-HD patients. The hematomas were significantly larger in the death cases (8.4 +/- 3.7%) than the survivors on HD (3.6 +/- 3.1%, p less than 0.005). Likewise, the fatal cases in the non-HD group had bigger hematomas (6.9 +/- 4.3%) than the non-fatal ones (3.6 +/- 2.4%, p less than 0.05). Intraventricular hemorrhage (IVH) was found in 40% of HD and 44% of non-HD patients. Hematomas were significantly larger in HD patients with IVH (9.3 +/- 3.3%) than in those without IVH (4.6 +/- 3.7, p less than 0.005). Ninety percent of the HD patients with IVH but only 42% of non-HD patients died of hemorrhage. Hypertension was equally seen in HD (76%) and non-HD patients (74%). It is concluded that in HD patients cerebral hemorrhage is more severe in terms of hematoma size, association of IVH and clinical outcome. Chronic systemic heparinization might be responsible to the severity in HD patients.

Adult↗
PubMed1987

Familial apoceruloplasmin deficiency associated with blepharospasm and retinal degeneration.

A 52-year-old woman had a newly recognized disorder of familial hypoceruloplasminemia, blepharospasm, retinal degeneration, and high-density areas in CT of the basal ganglia and liver scan. Immunofixation electrophoresis disclosed apoceruloplasmin deficiency. Kinetic, x-ray analysis, and histochemical study showed accumulation of iron in liver and brain, but not of copper. Intestinal copper absorption was reduced, but liver uptake was increased. Ceruloplasmin is involved in iron metabolism, and the findings suggest that hypoceruloplasminemia due to lack of apoceruloplasmin was causally linked to the iron deposition in basal ganglia and other organs, leading to blepharospasm and retinal degeneration.

Apoproteins↗
PubMed1987

Electrocorticogram in rats loaded with SART stress (repeated cold stress).

The electrocorticogram (ECoG) in a SART (specific alternation of rhythm in temperature)-stressed (repeatedly cold-stressed) rat, which is regarded as an experimental model for clinical vagotonic-type dysautonomia, was investigated in the present study by the power spectral technique. 1) Analysis of ECoG in SART-stressed rats during the resting-arousal state indicated a decrease in total power and a decrease in relative power in the delta band, and also an increase in relative power in the theta, alpha and beta bands. 2) In the slow-wave sleeping state, the ECoG of SART-stressed rats indicated a marked increase in total power, an increase in the delta band and decreases in theta, alpha and beta bands. 3) Electric stimulation of the posterior-hypothalamic area evoked alterations of ECoG similar to those caused by SART stress. ECoG response to electric stimulation in SART-stressed rats was less than that in unstressed rats. 4) Lesioning of the posterior-hypothalamic areas prevented SART stress-induced ECoG alterations. SART-stressed rats thus appear to be at a higher consciousness level on awakening but to sleep more soundly. They seem to exhibit greater fluctuation in brain activity than normal rats. There is also the possibility that the posterior-hypothalamic area is responsible to some degree for ECoG alterations in SART-stressed rats.

Animals↗
PubMed1987

Water intoxication due to excessive water intake: observation of initiation stage.

A patient who had experienced water intoxication despite normal renal function and normal urinary diluting ability was observed during the initiation stage of hyponatremia. Upon the excessive water intake (10 to 15 L) for several days, he developed moderate hyponatremia (121 mEq/L) and headache, an early symptom frequently seen in water intoxication. During this period, his urine was maximally dilute (50 to 60 mOsm/kg H2O), and his urinary sodium excretion increased. This report suggests that 10 to 15 L of water intake for several days can cause water intoxication in subjects with normal urinary diluting ability and that the increase in sodium excretion is prerequisite for the high urine flow rate.

Adult↗
PubMed1987

Effect of cytochrome c on formation of lipid peroxides in rat brain in vitro.

Antioxidant activity of exogenous cytochrome c was investigated in vitro using the whole brain homogenate, mitochondrial fraction and postmitochondrial supernatant containing microsomes prepared from rat brains. Increments in the amount of lipid peroxides were observed in each fraction when incubated at 30 degrees C, while the addition of cytochrome c (200 mM) effectively suppressed the production of peroxides. This depressive effect of cytochrome c was more prominent in the supernatant than in the mitochondrial fraction. Although the peroxidation was enhanced markedly by the addition of NADPH (2 mM), particularly in the mitochondrial fraction, cytochrome c was able to prevent its acceleration. This inhibitory mechanism might be explained by the fact that cytochrome c deprived superoxide radicals of electrons generated in ischemic insult. The results of the present study suggest that exogenous cytochrome c has free radical scavenging or antioxidant activity, which might be responsible in part for its cerebral protective action during ischemia.

Animals↗
PubMed1987

Suppression of tumor growth by in vivo administration of a recombinant human-mouse chimeric monoclonal antibody.

The in vivo administration of a recently described recombinant human-mouse chimeric antibody specific for a human common acute lymphocytic leukemia antigen (cALLA) caused significant inhibition of the tumorigenic growth of human leukemic cells (Manca cells, expressing cALLA on the surface) which were implanted into nude mice. Intratumor as well as intraperitoneal administration of the human-mouse chimeric antibody repressed the tumor growth of Manca cells in nude mice. In order to investigate the in vivo localization of the antibody molecules, the chimeric antibody was labeled with radioiodine (131I) and injected into nude mice transplanted with Manca cells. The labeled antibody was significantly localized in the tumor and the location of the tumor was successfully visualized by scintiphotoscanning. These results indicated that the recombinant human-mouse chimeric antibody can exert a significant antitumor effect in vivo and can be utilized for radio-immunoimaging. Since the chimeric human-mouse monoclonal antibody would be expected to have a much lower antigenicity to humans and much higher efficiency in the interaction with human effector cells, such recombinant chimeric antibodies may be beneficial for immunotherapy and immunoimaging of cancer patients.

Animals↗
PubMed1987

Interactive effect of Gm and Km allotypes on cellular immune responses to streptococcal cell wall antigen.

Serum samples from 121 unrelated, healthy Japanese individuals were typed for several Gm and Km(1) allotypes. Peripheral blood lymphocytes from these subjects were cultured with streptococcal cell wall (SCW) antigen and the incorporation of 3H-thymidine into T lymphoblasts was measured. Log-linear analysis showed a significant interactive effect of Gm1,17;13,16,21 and Km(1) on the cellular immune response to group A SCW antigen.

Adult↗