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Biomedical subjects

S Nishimura

Publications and source records attributed to S Nishimura.

At least 73 records · Page 4Linked to original sources
PubMed1992

Significance of increased lung thallium uptake during adenosine thallium-201 scintigraphy.

To determine the relationship of lung 201Tl activity during adenosine scintigraphy to the presence and extent of coronary artery disease, we investigated 132 subjects comprising 4 groups: 36 normal volunteers, 19 patients with angiographically normal coronaries, 29 patients with single-vessel (greater than 50% luminal stenosis) and 48 patients with multivessel coronary artery disease. Lung activity was quantified relative to maximal myocardial activity in both an early anterior planar image (pretomography) and the unprocessed tomographic image in the anterior projection. A good correlation was found for the lung-to-heart ratio assessed by planar and tomographic imaging (r = 0.83, p less than 0.0001), but the ratio was higher with planar imaging. The lung-to-heart ratio in the planar images was significantly higher in patients with multivessel disease compared to those with single-vessel disease (p less than 0.05) or volunteers and subjects with normal coronary arteries combined (p less than 0.001). A lung-to-heart ratio of greater than 0.45 in the planar images (upper 95% confidence limit for the normal subjects) was found in 6 (21%) single-vessel disease and 17 (35%) multivessel disease patients. Patients with elevated lung thallium activity during adenosine infusion had more hypoperfused myocardial segments (p = 0.007), more segments with redistribution (p = 0.04) and larger initial perfusion defect size (p = 0.04) than those with normal lung activity. Thus, evaluation of lung activity during adenosine thallium scintigraphy provides supplementary information regarding the severity of coronary artery disease and extent of myocardial hypoperfusion.

Adenosine↗
PubMed1992

[Changes in dementia after shunt surgery for normal pressure hydrocephalus].

In order to investigate the pathogenesis of normal pressure hydrocephalus (NPH), dementia was analyzed with regard to the characteristic preoperative picture, the time when dementia improved, and what aspect of dementia was improved, retrospectively. Twenty seven patients of NPH were divided into two groups; young adult group: patients under 64 years old and geriatric group: patients above 65 years old. We found that the only difference found between these two groups was severity in dementia grading, higher in geriatric group. Postoperative course or complications did not differ. Dementia in NPH was not an essential impairment of intellectual ability, but was characterized by the subset symptoms of dementia, such as decrease in spontaneity and interest, slowness and paucity of thought and action. Improvement of memory followed postoperative recovery of these subset symptoms which was observed at earliest three days after shunt surgery. We postulate that recovery of dementia in NPH is associated with not only a decrease in intracranial pressure but also an improvement in the microcirculation of the brain or an improved metabolism.

Adult↗
PubMed1992

[Pharmacokinetic, bacteriological and clinical studies on meropenem in children].

Pharmacokinetic, bacteriological and clinical studies on meropenem (MEPM) were performed in children. The results are summarized as follows: 1. A total of 16 patients was treated with MEPM. Each dose was 20 mg/kg, and administration was made 3 times daily using 30-minute intravenous drip infusion for 5-28 days. Clinical efficacies of MEPM in 16 patients with bacterial infections (1 with purulent meningitis, 1 with suspected subdural abscess, 2 with suspected sepsis, 4 with pneumonia, 1 with acute maxillar sinusitis, 2 with cervical abscess, 1 with acute gastroenteritis, 2 with skin soft tissue infection and 2 with urinary tract infection) were evaluated as excellent in 7 patients, good in 8 patients and fair in 1 patient with an efficacy rate of 93.8%. Fourteen causative organisms found in 11 patients (Streptococcus pneumoniae in 4, Branhamella catarrhalis in 3, Staphylococcus aureus in 3, Group B Streptococcus in 1, Escherichia coli in 3) were all eradicated. No adverse reactions were observed in any of the 16 patients. 2. MICs of MEPM against 6 clinically isolated bacteria (B. catarrhalis 2, S. pneumoniae 3 and S. aureus 1) from children with bacterial infections were examined. MEPM showed good antibacterial activities. 3. Pharmacokinetic studies: Peak plasma concentrations of MEPM averaged 43.07 micrograms/ml (37.20-46.30 micrograms/ml) at dose of 20 mg/kg administered by 30-minute drip infusion. In the first 8 hours after administration, the urinary excretion rates of MEPM averaged 39.9% of the administered dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

[Thermal regulation disturbance in severely handicapped patients--the second report].

Thirty-three severely handicapped patients were investigated on body temperature regulation by rectal temperature monitoring and hypophyseal hormonal function. The lowest body temperature in the day in the cases with handicaps of prenatal onset tended to be lower than that of peri or postnatal onset. This finding suggests that different causes make regulation disturbance of body temperature in handicapped children. On the other hand, low urine osmolarity in the morning and irregular menstruation were recorded suggesting hypothalamic dysfunction in poor regulation cases.

Body Temperature Regulation↗
PubMed1992

[Embolization for traumatic carotid cavernous sinus fistula using platinum coil].

We treated a patient with a traumatic carotid-cavernous fistula (CCF) by embolization using a Tracker catheter and platinum coils by transarterial and transvenous approaches. A 65-year-old female sustained an injury in the right frontal region of the head in April, 1989. After 1 month, she was admitted to our hospital due to exophthalmos, congestion of the palpebral conjunctiva, ptosis, and a bruise in the right frontal region of the head. Right carotid angiography showed a CCF between the anterior ascending segment and the horizontal segment that drains into the superior ophthalmic vein, superior petrosal sinus and inferior petrosal sinus. To occlude the fistula, embolization was performed twice using platinum coils. In the first embolization, the cavernous sinus was approached transarterially and transvenously using a Tracker catheter system, and a total of 7 platinum coils were used for the embolization. The bruise disappeared immediately after embolization but recurred 3 days after the operation. Angiography demonstrated re-communication of the CCF. The second embolization was initially performed using a detachable balloon, but the balloon could not be passed through the fistula. Therefore, a Tracker catheter was advanced to the fistula transarterially and embolization was performed using 3 platinum coils. The fistula was occluded. Follow-up angiography after 1 year in August, 1990 showed complete occlusion of the fistula. The detachable balloon system was recently introduced in neurological and radiological departments, as a new surgical method for CCF. At present, this method is the first choice for CCF. However, the detachable balloon system presents some technical problems.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

A glutamic acid residue at position 31 of Ras protein is essential to the signal transduction for neurite outgrowth of PC12 cells and the stimulation of GTPase activity by GAPRas.

The roles of residues at positions 23-31 adjacent to the 'effector region' and residues at positions 61-65 in a phosphoryl binding loop of the human c-Ha-ras protein were studied by changing each residue of the normal (Gly-12 type) and oncogenic (Val-12 type) Ras proteins to the corresponding residue of the K-rev-1 protein. Firstly, the signal-transducing activities of the mutant Ras proteins of Val-12 type were examined by analysis of their ability to induce neurite outgrowth of phaeochromocytoma (PC12) cells upon expression of the mutant ras gene. Thus, replacement of Glu-31 by Lys was found to impair the signal-transducing activity of the oncogenic Ras protein. Furthermore, it was shown that expression of the Gly-12----Val/Glu-31----Lys mutant Ras protein in PC12 cells suppresses neurite outgrowth induced either by microinjection of the oncogenic Ras protein or by addition of nerve growth factor to the medium. As for the Glu-31----Lys mutant Ras protein (Gly-12 type), the GTPase activity in the presence of GTPase-activating protein for Ras (GAPRas) is much lower than that of the normal Ras protein, whereas the intrinsic GTPase activity is nearly the same as that of the normal Ras protein. Therefore, Gly-31 is one of the determinants for the signal transduction and the correct interaction with GAPRas. On the other hand, the GTPase activity of the Gln-61----Thr mutant Ras protein (Gly-12 type) is negligibly low both in the absence and in the presence of GAPRas.

Amino Acid Sequence↗
PubMed1992

[A retrospective comparison study of patients old and young with non-Hodgkin's lymphoma].

One hundred patients with diffuse non-Hodgkin's lymphoma were treated with combination chemotherapy including adriamycin. Seventy-one patients were under age 70 and 29 were 70 years or older. The clinical characteristics of the two groups were similar, except that the patients showed elevated serum BUN were in the elderly group. The complete remission rate in the elderly patients (66%) was slightly lower than that in the younger patients (75%) (p = NS). The average length of survival in the elderly patients was significantly shorter than in the younger patients (p less than 0.05) (projected 5-year survival: 28 +/- 11% vs 52 +/- 7%). The duration of remission for all patients in the elderly patients did not differ from that in the younger patients (projected 2-year survival: 40 +/- 10% vs 45 +/- 6%). Death during the induction chemotherapy from causes other than lymphoma occurred in 14% of patients over 70-year-old and in one percent of younger patients. At relapse, the response rate was significantly lower in the elderly patients than in the younger patients (CR+PR: 28% vs 78%, p = 0.03). To prevent toxic death in remission induction therapy, drug dose elderly patients should be attenuated according to their general conditions and performance status.

Age Factors↗
PubMed1992

cdc2-like kinase is associated with the retinoblastoma protein.

The growth-suppressive activity of the retinoblastoma (RB) protein is suggested to be regulated by phosphorylation. In studies on the kinase that phosphorylates the RB proteins, we have previously found that RB proteins can be phosphorylated by purified cdc2 kinase. In this study, we noted that RB proteins immunoprecipitated from human cell lysates are weakly phosphorylated in the absence of purified cdc2 kinase. Immunoblot analysis showed the presence of p34cdc2 in the immunoprecipitates with anti-RB monoclonal antibody. In addition, the coprecipitated kinase was found to have the same substrate specificity as cdc2 kinase. The associated kinase activity was particularly high in cells arrested in G1/S and S phase by aphidicolin. Furthermore, RB proteins were shown to be phosphorylated in nuclear extracts by some endogenous cdc2-like kinase(s). These results suggest that cdc2-like kinase is the main kinase for phosphorylation of RB proteins in vivo.

Amino Acid Sequence↗
PubMed1992

[Münchhausen syndrome with severe iron deficiency anemia].

A patient with Münchhausen syndrome who had severe iron deficiency anemia (IDA) is reported. A 31 year-old female presented with irregular genital bleeding. However, gynecological examination disclosed no evidence of specific disorders causing bleeding. Tests for bleeding tendency and hemolysis were all negative. Although massive bleeding was absent, she had three episodes of a rapid fall in Hb level associated with marked fatigue and weakness, and subsequently rapidly developed serious IDA afterwards. Factitious bleeding was strongly suspected. Blood transfusion performed when the patient was not being watched failed to increase Hb, while transfusions given while the patient was watched were effective. She was not cooperative throughout the hospital course and was discharged on her own request. In outpatient clinic, the diagnosis was confirmed by the evidence that she diluted her own blood samples.

Adult↗
PubMed1992

[Management of elderly patients with aneurysmal subarachnoid hemorrhage].

Clinical features of 61 elderly patients aged over 70 years with ruptured intracranial aneurysms were compared with those of 328 younger patients aged under 70 years. According to a policy of early operation, elderly patients with Hunt and Kosnik's grade I, II and younger patients with grade I, II, III were operated on in the acute stage. In elderly patients with grade III, IV and younger patients with grade IV, the indication for surgery was determined case by case. Surgery was performed on 29 patients (48%) in the elderly group and 277 patients (86%) in the younger group. Our conclusions are as follows: 1. Regarding cases of grade I, II and III of Hunt and Kosnik's classification, the rate of good outcome in the elderly group was similar to that in the younger group, following early surgery and meticulous post-operative care. 2. In the elderly group, no patient in cases of grade IV obtained good surgical outcome. 3. Symptomatic vasospasm was less frequent in elderly patients (18.8%) than in younger cases (37%). 4. Delayed operation was planned for some patients in the elderly group, but none of them underwent surgery because of rerupture of aneurysms and deterioration of general condition.

Adult↗
PubMed1992

[B-cell chronic lymphocytic leukemia complicated by autoimmune thrombocytopenic purpura].

A 74-year-old Japanese male was admitted because of anemia. Hepatosplenomegaly, lymphoadenopathy, and purpura were not found. The laboratory data on admission revealed that the white-cell count was 9,400/microliters, the hemoglobin 11.1 g/dl, and the platelet count 17,000/microliters. Platelet-associated IgG was 794.2 ng/10(7) cells. The patient was diagnosed as having autoimmune thrombocytopenic purpura (ATP) at this time. He was treated with prednisolone, but his thrombocytopenia not improve. In addition to prednisolone, azathioprine was given to him. During the course of treatment, leukocytosis gradually appeared and the white-cell count reached more than 30,000/microliters with over 70% lymphocytes. A bone marrow aspiration revealed 70% of small lymphocytes, and surface marker analysis showed that CD19 and HLA-DR were positive on these lymphocytes. Southern blotting analysis demonstrated rearrangements of JH and JK. He was finally diagnosed as B-CLL complicated by ATP. One month after the azathioprine administration, the platelet count increased more than 30,000/microliters and the white-cell count decreased less than 10,000/microliters. About 2% of patients with CLL are known to be complicated by ATP. To our knowledge, the present case is the first case of B-CLL complicated by ATP in Japan.

Aged↗
PubMed1991

A peptide from the GAP-binding domain of the ras-p21 protein as well as azatyrosine block ras-induced maturation of Xenopus oocytes.

The ras-oncogene-encoded p21 protein is known to produce malignant transformation of NIH 3T3 cells as well as maturation of Xenopus oocytes when microinjected into these cells. p21 protein is known to bind a GTPase activating protein (GAP) intracellularly; residues 32-45 have been implicated in interacting with GAP. We demonstrate here that a peptide corresponding to residues 35-47 of p21 as well as the antibiotic azatyrosine inhibit the ras-induced maturation of Xenopus oocytes in a dose-related manner upon microinjection. We have previously shown that this p21 peptide and azatyrosine could inhibit the effects of p21 protein on cell transformation and pinocytosis in NIH 3T3 cells. In the present study, in which we have extended these results to the oocyte system, we also demonstrate that both partially inhibit insulin-induced oocyte maturation, a process which is thought to involve activation of endogenous p21 protein; on the other hand, both agents fail to inhibit oocyte maturation induced by progesterone, which is known not to act through p21 protein activation. Control studies with other peptides and tyrosine analogues support the selective nature of these events. These results suggest that both the p21-related peptide and azatyrosine have potent anti-ras effects intracellularly.

Alanine↗
PubMed1991

Identification of amino acid residues of Ras protein that are essential for signal-transducing activity but not for enhancement of GTPase activity by GAP.

To determine the amino acid residues required for the signal-transducing activity of the human c-Ha-Ras protein, we introduced point mutations at residues 45-54 near the 'effector region' (residues 32-40). We transfected PC12 cells with these mutant genes and also micro-injected the mutant proteins, bound with an unhydrolyzable GTP analog, into PC12 cells. Both procedures showed that Val45----Glu and Gly48----Cys mutations impaired the ability of the Ras protein to induce morphological change of PC12 cells. These mutations did not affect the guanine nucleotide-binding activity or GTPase activity in the absence or presence of bovine GTPase-activating protein (GAP). Therefore, the Val45 and Gly48 residues should be included by definition in the effector region responsible for the signal transduction, while only a subset of the effector-region residues is required for enhancement of the GTPase activity by GAP.

Adrenal Gland Neoplasms↗
PubMed1991

N-methyl-D-aspartate and aspartate raise the cytosolic free calcium concentration by acting upon receptors transiently expressed on immature cerebellar Purkinje cells.

N-Methyl-D-aspartate (NMDA) or aspartate (Asp) increased the cytosolic free calcium concentration ([Ca]in) in some populations of Purkinje cells dissociated from immature rat cerebellum. The NMDA- and Asp-induced rise in [Ca]in was affected only a little by adding glycine or NMDA antagonists, but was reduced either by adding Mg2+, Gallopamil hydrochloride (D-600) and gamma-amino-butyric acid, or by removing external Na+. The results suggest that stimulation of the NMDA-sensitive receptors transiently expressed on immature Purkinje cell soma results in a rise in [Ca]in through the activation of voltage-dependent Ca2+ channels.

2-Amino-5-phosphonovalerate↗
PubMed1991

Production of hepatitis B virion-like particles in yeast.

We constructed a yeast strain that simultaneously expresses four genes encoding the major S, middle S, large S hepatitis B viral envelope proteins and the core protein under the control of the yeast glyceraldehyde-3-phosphate dehydrogenase promoter and terminator. The lysate from this cell line, examined by immunological, physicochemical methods and electron microscopy, was found to contain spherical particles with a diameter of about 40 nm and a density of 1.25 g/ml. These particles reacted with anti-envelope antibodies, but not with anti-core antibodies. However, core antigenicity appeared upon treatment with 3% Nonidet P-40 that eliminates an outer envelope. These observations suggest production of a virion-like complex structure, or at least its DNA-less analog, consisting of core particle enveloped by antibody-reactive envelope. Such a structure was made only when all the four gene products were synthesized in a yeast cell. This system may be useful for the study of virus structure and assembly, and for improved vaccine development.

Blotting, Western↗