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Biomedical subjects

T Nishimura

Publications and source records attributed to T Nishimura.

At least 91 records · Page 5Linked to original sources
PubMed1994

[Bacteriological and clinical studies of biapenem (L-627) in pediatric field].

We have carried out bacteriological and clinical studies on L-627. The results are summarized as follows. Treatment with L-627 was made in 14 cases of pediatric bacterial infections including 5 cases of pneumonia and 2 cases each of tonsillitis, urinary tract infection and one case each of colitis, and phlegmon. Results obtained were excellent in 11 cases, good in 2 cases and poor in one case. The bacteriological effect of L-627 was excellent, all causative organisms (Staphylococcus aureus one strain, Streptococcus pyogenes 2 strains, Streptococcus pneumoniae 3 strains, Escherichia coli 3 strains, Haemophilus influenzae one strain, Haemophilus parainfluenzae one strain) were eradicated. No significant side effects due to the drug were observed in any cases, except 2 cases each of elevated eosinophil counts and elevated platelet counts.

Bacteria↗
PubMed1994

[A case of ventricular septal defect and patent ductus arteriosus associated with absent right pulmonary artery, scimitar syndrome and severe pulmonary hypertension].

A 8 month-old female was diagnosed with ventricular septal defect and patent ductus arteriosus associated with absent right pulmonary artery and scimitar syndrome. Cardiac catheterization revealed severe pulmonary hypertension as follows; 72 mmHg of mean pulmonary artery pressure, 0.56 Qp/Qs and 1.73 Pp/Ps. Temporary closure of the ductus reduced the mean pulmonary artery pressure from 72 to 40 mmHg. PDA was ligated and VSD was closed successfully. However, 4 months after initial operation she was readmitted due to infection of the hypoplastic right lung. Removal of the hypoplastic right lung was performed and postoperative course was uneventful.

Ductus Arteriosus, Patent↗
PubMed1994

[A case of inflammatory abdominal aortic aneurysm with associated inferior vena caval and bilateral ureteral obstruction].

One year ago, a 48-year-old man complained of dyspnea, and was diagnosed as mitral valve regurgitation and aortic dissection. He underwent mitral valve replacement and aortic arch grafting. He was also pointed out to have an inflammatory aortic aneurysm (IAAA) in the infrarenal abdominal aorta, but did not undergo surgery. At this admission, he had lumbago and low grade fever probably due to deterioration of the IAAA. On the preoperative radionuclide studies, inferior vena caval obstruction and bilateral ureteral obstruction or severe stenosis were demonstrated by 99mTc-MAA venography and 123I-OIH renogram, respectively. 67Ga scan showed faint abnormal accumulation at the IAAA. He underwent surgery. IAAA had a thick wall in white and hard fibrotic tissue adhered closely to duodenum, jejunum, inferior vena cava and bilateral ureters. After surgery, his renal function was improved. In this case, radionuclide studies were useful for detecting the inferior vena caval obstruction, assessing renal function and inflammatory activity.

Aneurysm, Infected↗
PubMed1994

[Standardization of regional cerebral count corrected by equilibrium blood count with 99mTc-HMPAO brain SPECT].

To standardize the regional cerebral count with 99mTc-HMPAO, equilibrium blood count of which trapping mechanism is the same as the brain was used in seven patients with cerebrovascular disease. We injected 99mTc-HMPAO 740 MBq in 10-15 sec and got sequential arterial sampling in patients who were undertaken with PET. Four hours later 99mTc-HMPAO brain SPECT was taken and a venous sampling was drawn for determining the equilibrium blood count. Correlation between the area of arterial time activity curve and equilibrium venous blood count was 0.93. After 44 regions (36 in cortical area, 8 in deep area) with 99mTc-HMPAO brain SPECT were placed, SPECT counts were corrected by standardization of equilibrium venous blood count. The correlation between rCBF determined from C15O2 PET and corrected SPECT counts was 0.80 and 0.67, cortical area and deep area, respectively. We concluded that 99mTc-HMPAO brain SPECT count can be corrected by equilibrium blood count to standardize the regional cerebral counts.

Aged↗
PubMed1994

Brain interleukin-1 beta in Alzheimer's disease and vascular dementia.

Recent investigations indicate that a neuroimmune reaction, associated with inflammatory mechanisms, can contribute in Alzheimer's disease (AD) to cell damage and neurodegeneration. Activation of microglial cells, expression of immunohistochemical markers of brain immune function, the presence of complement proteins in brain tissue and changes in cytokine production have been reported in AD. We have studied the concentration of interleukin-1 beta (IL-1 beta) in different regions of the central nervous system (CNS) in post-mortem samples from patients with AD or vascular dementia (VD) and in age-matched control subjects (CS). IL-1 beta levels were significantly higher in AD than in VD or CS in the frontal cortex, parietal cortex, temporal cortex, hypothalamus, thalamus and hippocampus. The highest increases in IL-1 beta levels were observed in the frontal cortex (CS = 0.75 +/- 0.045; AD = 2.47 +/- 0.12, p < 0.001; VD = 1.52 +/- 0.078 pg/mg, p < 0.001) and hippocampus (CS = 0.71 +/- 0.042; AD = 2.63 +/- 0.19, p < 0.001; VD = 1.21 +/- 0.23 pg/mg, p < 0.01). No significant changes were detected in the occipital cortex and cerebellum in either AD or VD. These results clearly demonstrate that demented patients show a generalized increment of IL-1 beta production in the CNS, with maximum response in those brain regions where AD neuropathology is most prominent. This overall increase in cytokine production might represent an early event in the activation of a neuroimmune cascade leading to cell death and neurodegeneration in brain regions where a primary cause (e.g., genetic, toxic, vascular) facilitates the induction of resting microglia for firing brain immune function.

Aged↗
PubMed1994

Pharmacological properties of the new stable prostacyclin analogue 3-Oxa-methano-prostaglandin I.

The pharmacological characteristics of the 3-oxamethano-prostaglandin I1 compound (+)-methyl [2-[(2R,3aS,4R,5R,6aS)-octahydro-5-hydroxy-4- [(E)-(3S,5S)-3-hydroxy-5-methyl-1-nonenyl]-2-pentalenyl]etho xy] acetate (SM-10902, CAS 139403-31-9), a novel stable analogue of prostacyclin and its free acid, SM-10906, were studied. SM-10902 was rapidly deesterified to its free acid in rabbit and human serum. SM-10902 and SM-10906 exhibited antiplatelet potency against ADP-induced aggregation in rabbit and human platelets. In the presence of diisopropyl fluorophosphate, an esterase inhibitor, the antiplatelet activity of SM-10902 was markedly reduced, to much less than that of SM-10906. SM-10906 inhibited platelet aggregation induced by various inducers in several species and enhanced the cyclic AMP (cAMP) level in human platelets. These activities were nearly equal to those of prostaglandin (PG) E1 and less than those of PGI2. SM-10906 relaxed isolated rabbit mesenteric and bovine coronary arteries, and elevated the cAMP level in bovine coronary arteries. SM-10906 given intravenously exhibited a sustained reduction in blood pressure based on vasodilation in ganglion-blocked, angiotensin II-supported rats. SM-10902 applied to the guinea-pig auricles increased the skin temperature, but SM-10906 and PGI2 showed no such effect. In conclusion, SM-10902, which is considered to be a prodrug of SM-10906, was suggested to exert its anti-platelet and vasodilator activities through the increase of cAMP. Since SM-10902 penetrates well into the skin, it may be useful as an external preparation to improve peripheral circulatory insufficiency.

Adenylyl Cyclase Inhibitors↗
PubMed1994

Split dose iodine-123-IMP SPECT: sequential quantitative regional cerebral blood flow change with pharmacological intervention.

UNLABELLED: At least two quantitative rCBF measurements are needed to evaluate rCBF changes with pharmacological intervention. We have developed the split dose 123I-IMP SPECT method, which enables measurement of rCBF to be repeated in a short time. METHODS: Thirty-one cerebrovascular disease patients were investigated to assess reproducibility and vasoreactivity to acetazolamide. During 44-min dynamic SPECT imaging, 123I-IMP injection and respective arterial sampling were performed twice at an interval of about 25 min. The rCBF values were calculated using a microsphere model in which the washout of 123I-IMP from the brain can be negligible in the first several minutes after injection. For the second rCBF measurement, the remaining activity due to the first 123I-IMP injection was estimated and subtracted from the total brain activity. RESULTS: In ten patients, two consecutive resting mean rCBF values in the MCA territory (CBF1 and CBF2) had good correlation (CBF1 = 47.4 +/- 4.0 (ml/min/100 ml: mean +/- s.d.), CBF2 = 45.2 +/- 8.2, CBF2 = 0.900*CBF1 + 2.9, r = 0.915). In 11 patients with occlusive lesions in the unilateral ICA system, mean rCBF in the MCA territory was increased by only 27.7% +/- 14.0% in the affected side by a 1-g intravenous acetazolamide injection, while 44.5% +/- 12.3% increase was found in the nonaffected side. In 10 patients without a major arterial lesion, a 49.7% +/- 17.0% increase of rCBF was demonstrated. CONCLUSIONS: This split dose method 123I-IMP SPECT can be useful to estimate vascular reserve.

Acetazolamide↗
PubMed1993

Activation of two angiotensin-generating systems in the balloon-injured artery.

Participation of angiotensin II in the myointimal proliferation following a vascular injury was postulated. This study assessed the potential involvement of the local angiotensin II-forming enzymes in injured arteries of dogs. The potential angiotensin II-forming enzymes are angiotensin-converting enzyme (ACE) and chymostatin-sensitive angiotensin II-generating enzyme (CAGE) which is highly homologous to or could be identical to the mast cell chymase. Both ACE and CAGE catalyze the conversion of angiotensin I to angiotensin II. We found that the enzymatic activities of ACE and CAGE, and the mRNA levels of ACE and chymase were increased in the injury-induced hypertrophied vessels. The results suggest that ACE and CAGE participate in the hypertrophy through the production of angiotensin II which is a growth promoter for vascular smooth muscle cells.

Angiotensin II↗
PubMed1993

Neuropathologic changes in the gerbil brain after chronic hypoperfusion.

BACKGROUND AND PURPOSE: An animal model has been developed to elucidate the pathological changes in brain cytoskeletal proteins during chronic hypoperfusion. METHODS: Newly designed coiled clips were placed around both carotid arteries of Mongolian gerbils (n = 10) to cause stenosis without occlusion. Those gerbils showing impaired learning ability by the passive avoidance paradigm were killed for neuropathologic study after 12 weeks. RESULTS: The brains showed ventricular dilatation, cortical atrophy, and rarefaction of the white matter. Immunoreactivity to anti-microtubule-associated protein 2 antibody in the cerebral cortex and the hippocampus was diminished, indicating dendritic changes of neurons. In the thalamic axonal regions, staining with anti-neurofilament 200K protein antibody was increased, suggesting increased amounts of neurofilament proteins or increased phosphorylation of the protein. Increased immunoreactivity to anti-glial fibrillary acidic protein antibody was observed in a wedge-shaped configuration, corresponding to the border zone of perfusion by small vessels. CONCLUSIONS: These findings suggest that changes in the cytoskeletal proteins in dendrites, axons, and glial cells may cause neuronal death under conditions of chronic cerebral hypoperfusion.

Animals↗
PubMed1993

Perfusion lung scintigraphy in primary pulmonary hypertension.

15 cases of primary pulmonary hypertension were classified into two groups by patterns of perfusion lung scintigraphy. Perfusion scintigrams showed multiple, small, ill-defined defects (mottled + ve) pattern in eight cases, and the remaining seven cases had a normal (mottled - ve) pattern. The mean pulmonary arterial pressure in patients with a mottled pattern (54 +/- 10 mmHg) was higher than in those with a normal pattern (42 +/- 9 mmHg, p < 0.05). There were no significant differences between the two groups in right ventricular ejection fraction, partial pressures of oxygen in the arterial blood or alveolo-arterial oxygen difference. All the patients with a mottled pattern died within 2 years following the lung scintigraphy. There was a significant difference in the survival curves between the two groups. Although our statistical analysis must be evaluated with caution because of small numbers of patients it is suggested that perfusion lung scintigraphy is useful in assessing the prognosis in primary pulmonary hypertension.

Adult↗
PubMed1993

New mutation of the myelin P0 gene in a pedigree of Charcot-Marie-Tooth neuropathy 1.

P0, the major structural protein of peripheral myelin, is a homophilic adhesion molecule with a single immunoglobulin (Ig) domain, which contains a single N-linked glycosylation site and two cysteines. We have previously reported four different mutations of the myelin P0 gene in four families of Charcot-Marie-Tooth neuropathy type 1 (CMT1). In this study we found a new mutation of the myelin P0 gene in a small family of CMT1. The affected persons had an A - to - G substitution of nucleotide 245 of the myelin P0 gene in one allele, leading to a cysteine substitution for tyrosine82 in the extracellular Ig-domain. An additional cysteine in the extracellular domain may form a disulfide bond and cause an inappropriate change in the tertiary structure of the functional Ig-domain of P0.

Adolescent↗
PubMed1993

[A case of amylase producing lung cancer].

The patient was a 72-year-old man, who was admitted to our hospital because of cough. Chest X-rays showed a mass shadow in the right lower lung field. Amylase activities in serum and urine were extremely high. Amylase isozyme pattern identified salivary type amylase. Cytological examination of the sputum suggested adenocarcinoma. Amylase activities in serum and urine gradually decreased with the administration of chemotherapy. Afterwards, pleural effusion increased, and the amylase activity in pleural fluid was also extremely high. Pleural fluid also showed adenocarcinoma. Enzyme-labeled antibody method (PAP) on this specimen from pleural fluid proved that tumor cells were producing amylase ectopically.

Adenocarcinoma↗
PubMed1992

Assembly regulatory domain of glial fibrillary acidic protein. A single phosphorylation diminishes its assembly-accelerating property.

Phosphorylation of glial fibrillary acidic protein (GFAP) induces disassembly of the filaments. An amino-terminal fragment of bovine GFAP (G-Hf) was produced by lysylendopeptidase digestion. G-Hf formed ribbon-like filaments in the presence of GFAP even in low ionic strength, whereas the fragment itself did not form any structures. Only one (PK3) of the five V8 protease fragments of G-Hf accelerated GFAP assembly to the same degree as G-Hf did, whereas the other fragments did not. When PK3 was cleaved into two fragments, it lost the assembly-accelerating property. The sequence of PK3 was determined as RRRVTSATRRSYVSSSE, which corresponded to residues 3-19 of porcine GFAP. It was concluded that PK3 contains a sequence indispensable for GFAP assembly and that neither PK1 (RRRVTS) nor PK2 (ATRRSYVSSSE) included all of the sequence. A single phosphorylation of PK3 by cyclic AMP-dependent protein kinase diminished its assembly-accelerating property. The phosphorylation site was determined as Ser-12 of porcine GFAP. It was shown that single phosphorylation of the amino-terminal head domain, which contains an indispensable sequence for GFAP assembly, might be sufficient for GFAP disassembly.

Amino Acid Sequence↗
PubMed1992

Cellular and peptide requirements for in vitro clonal deletion of immature thymocytes.

Thymocytes from DO10 T-cell-receptor transgenic mice undergo apoptosis, or programmed cell death, when chicken ovalbumin-(323-339) peptide is administered in vivo. Using DO10 mice thymocytes, we have now developed a simple in vitro model system that recapitulates the in vivo clonal-deletion process. When transgenic thymocytes were cocultured with fibroblasts, B cells, or thymic nurse cell lines (all bearing I-Ad) in the presence of chicken ovalbumin-(323-339), deletion of the transgenic TCR+CD4+CD8+ thymocytes was seen within 8-20 hr. Thymocytes designed to bear I-Ad on their surface could mediate the deletion themselves. Thus, thymocyte clonal deletion entirely depends on the stage at which the thymocytes are vulnerable to the onset of apoptosis, rather than on the nature of the peptide antigen-presenting cells. Furthermore, thymic nurse cell line TNC-R3.1 could cause deletion, strongly suggesting that some thymic epithelial/stromal components are potentially capable of participating in negative selection. In all cases examined, little deletion could be induced at a peptide concentration less than 10 nM, thus defining the minimum amount of peptide antigen required for negative selection. The peptide-dependent in vitro negative-selection system will allow further dissection of the molecular and cellular processes involved in clonal deletion due to apoptosis in the thymus.

Amino Acid Sequence↗
PubMed1992

[Detectability of diagonal branch disease by 201TlCl exercised myocardial scintigraphy].

The detectability of diagonal branch disease in 10 patients (five with angina pectoris, five with myocardial infarction) with isolated diagonal branch lesions (more than 75% luminal stenosis in coronary angiography) was reviewed. In exercised 201TlCl myocardial scintigraphy, chest pain occurred in four of 10 patients, electrocardiographic change indicating myocardial ischemia was seen in four, and diagonal branch lesion was detected in only four patients by planar images. In contrast, diagonal branch lesions were detected in 10 of 10 patients by SPECT (single photon emission computed tomography). In planar images, perfusion defects appeared high in the anterolateral, posterolateral, and anterior walls of the left ventricle. In SPECT images they appeared high in the anterior to anterolateral wall. The extent of diagonal branch lesions could be quantitatively evaluated by coronary territory maps developed from unfolded maps of exercised SPECT. The mean ratio of the extent of diagonal branch lesion to left anterior descending branch territory was 24.7%, and the extent of myocardial infarction was significantly larger than that of angina pectoris (p < 0.05). In conclusion, SPECT is useful for detecting diagonal branch lesions and can quantitatively show the extent of these lesions by coronary territory map.

Aged↗
PubMed1992

Purification and properties of aminopeptidase H from chicken skeletal muscle.

Aminopeptidase H was purified from fresh chicken breast muscle by ammonium sulfate fractionation and successive chromatographies on DEAE-cellulose, Ultrogel AcA 34, activated thiol-Sepharose 4B, phenyl-Sepharose CL-4B and DEAE-cellulose again. The purified enzyme migrated as a single band on SDS/PAGE. Aminopeptidase H exhibits activity against both L-leucine beta-naphthylamide and alpha-N-benzoyl-DL-arginine beta-naphthylamide. The molecular mass of this enzyme was found to be 52 kDa on SDS/PAGE and 400 kDa on Sepharose 6B column chromatography. The optimum pH for the hydrolysis of both substrates was 8.0 and this activity was remarkably enhanced by reducing agents. The enzyme was strongly inhibited by monoiodoacetate and leupeptin, but not affected by EDTA, phenylmethylsulfonyl fluoride, pepstatin, bestatin or puromycin. Aminopeptidase H has been shown to hydrolyze di-, tri- and tetrapeptides in the manner of an aminopeptidase, as well as the beta-naphthylamide derivatives of amino acids. However, the enzyme has not been shown to hydrolyze proteins such as hemoglobin, bovine serum albumin, myofibrillar proteins or sarcoplasmic proteins.

Amino Acid Sequence↗
PubMed1992

[Raise up 99mTc-HMPAO brain SPECT for detecting the changes in cerebral perfusion pressure].

99mTc-HMPAO crossed the blood brain barrier instantly in proportional to cerebral blood flow. Raise up stress and supine resting 99mTc-HMPAO with brain SPECT was devised for detecting abnormal response in the changes of cerebral perfusion pressure. Asymmetric ratio in the middle cerebral artery area in patients with internal carotid artery occlusion (n = 5) was changed significantly from 0.82 +/- 0.06 to 0.90 +/- 0.06 and that of normal (n = 5) was not changed from 0.94 +/- 0.03 to 0.95 +/- 0.01. Raise up 99mTc-HMPAO brain SPECT enhanced the detectability in abnormality of regional cerebral blood flow and visualized the dys-autoregulated area during blood pressure falls.

Blood Pressure↗