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Biomedical subjects

K Kawamura

Publications and source records attributed to K Kawamura.

At least 127 records · Page 7Linked to original sources
PubMed1999

Alternative angiotensin II formation in rat arteries occurs only at very high concentrations of angiotensin I.

Contrary to previous reports, recent enzymatic assays showed the predominance of chymase-like activity in rat arteries. We determined the existence and significance of such alternative pathways in rat carotid arteries by measuring contraction of arterial rings in organ baths and blood pressure in conscious rats. Hamster aorta served as a positive control for chymase. Temocapril (30 micromol/L) inhibited the contractions to angiotensin (Ang) I (10(-9) to 10(-5) mol/L) except at high concentrations of Ang I (>10(-7) mol/L). Addition of chymostatin (100 micromol/L) to temocapril exerted a synergistic inhibitory effect. Hamster aorta gave similar results, except that temocapril was 30-fold less effective than in rat arteries. [Pro(11), D-Ala(12)]Ang I (10(-8) to 10(-5) mol/L), a chymase-specific substrate, provoked similar responses in rat and hamster arteries; chymostatin, but not temocapril, attenuated the responses. CV 11974 (30 micromol/L), an Ang II type 1 receptor antagonist, abolished the responses to both peptides. In conscious rats, Ang I (0.03 to 30 microg/kg) and [Pro(11),D-Ala(12)]Ang I (7 to 700 microg/kg) produced similar pressor responses. Not only CV 11974 (1 mg/kg) but also temocapril (2 mg/kg) abolished Ang I-induced responses in vivo. CV 11974, but not temocapril, inhibited responses to [Pro(11), D-Ala(12)]Ang I. Our results showed the presence of the alternative pathway in rat arteries, but it did not play a major role. Arteries with the opposing characteristics of chymase responded equally to [Pro(11),D-Ala(12)]Ang I. These findings suggest that biochemical and [Pro(11),D-Ala(12)]Ang I-derived results may not reflect the functional significance of chymase.

Angiotensin I↗
PubMed1999

An investigation of the disabled elderly in a geriatric health services facility in an urban area of Japan and attitudes of their family caregiver.

We investigated characteristics of 72 clients in a geriatric health services facility (hereafter called GHSF), conditions of their family caregivers, and the factors associated with the caregivers choice of discharge destination. Most of the clients were elderly females with a low degree of independence, and dementia was observed in about 60% of them. The clients had children, but many of them lived alone before admission to the GHSF. The rate of admission from hospitals was high (54%), and that of discharge to hospitals was also high (50%). Sixty-seven percent of the clients stayed in for a period of over six months. Most of the family caregivers were daughters or daughters-in-law, and considered themselves to be healthy. Sixty-three percent of them had jobs, and most of the caregivers had no sub-caregiver to assist them. The family caregivers desired the client's home (19.4%), hospital or another GHSF (54.2%), or nursing home (26.4%) as the discharge destination from the GHSF. According to Hayashi's quantification theory type II, the factors related to the home as the discharge destination desired by client's family caregivers are as follows; caregivers used formal home public health nursing visit service before entering the GHSF, the job of the caregiver was a part-time job, the client did not show dementia, the period of care experience was shorter than one year.

Aged↗
PubMed1999

Regulation of growth hormone-releasing hormone receptor messenger ribonucleic acid expression by glucocorticoids in MtT-S cells and in the pituitary gland of fetal rats.

Regulation of GH-releasing hormone receptor (GHRH-R) messenger RNA (mRNA) expression was studied, with the ribonuclease protection assay, in the fetal rat pituitary gland and in MtT-S clonal cells. GHRH-R mRNA was first detected on embryonic day (E)19 and increased rapidly thereafter, to reach a maximum at E21. Incubation of E17 or E18 pituitaries with 50 nM dexamethasone (DEX), a synthetic glucocorticoid, induced GHRH-R mRNA expression, suggesting that glucocorticoids play a pivotal role in the developmental expression of this mRNA. In E19 pituitaries, 24 h treatment with DEX increased GHRH-R mRNA by 60%, and GH mRNA by 76%, but did not affect pit-1 mRNA level, suggesting that the effect of DEX is specific for expressions of GH mRNA and GHRH-R mRNA. The accumulation of GHRH-R mRNA by DEX was time dependent, and it was slightly enhanced by the protein synthesis inhibitor, puromycin (100 microM). In MtT-S cells (a pituitary cell line established from an estrogen-induced tumor), DEX induced GHRH-R mRNA expression within 2 h in a dose-dependent manner. This induction was augmented by puromycin (100 microM) or cycloheximide (3.5 microM). However, the RNA synthesis inhibitor Actinomycin D (1 microM) completely inhibited GHRH-R mRNA accumulation in response to either DEX or DEX plus puromycin, suggesting that glucocorticoids induce GHRH-R mRNA mainly through stimulation of mRNA transcription. These results suggest: that GHRH-R mRNA accumulation in the fetal pituitary gland of rats normally occurs at E19, probably because of the direct action of glucocorticoids on the pituitary gland, to stimulate GHRH-R mRNA transcription; and that the expression of glucocorticoid receptors is an important event in GH cell development in rats. Accordingly, immunocytochemical results suggest an increase in glucocorticoid receptors in immature GH cells between E17 and E18. The present results also imply that MtT-S cells may be a good model in which to further study the molecular mechanisms of the regulation of GHRH-R gene expression.

Animals↗
PubMed1999

A new family of growth factors produced by the fat body and active on Drosophila imaginal disc cells.

By fractionating conditioned medium (CM) from Drosophila imaginal disc cell cultures, we have identified a family of Imaginal Disc Growth Factors (IDGFs), which are the first polypeptide growth factors to be reported from invertebrates. The active fraction from CM, as well as recombinant IDGFs, cooperate with insulin to stimulate the proliferation, polarization and motility of imaginal disc cells. The IDGF family in Drosophila includes at least five members, three of which are encoded by three genes in a tight cluster. The proteins are structurally related to chitinases, but they show an amino acid substitution that is known to abrogate catalytic activity. It therefore seems likely that they have evolved from chitinases but acquired a new growth-promoting function. The IDGF genes are expressed most strongly in the embryonic yolk cells and in the fat body of the embryo and larva. The predicted molecular structure, expression patterns, and mitogenic activity of these proteins suggest that they are secreted and transported to target tissues via the hemolymph. However, the genes are also expressed in embryonic epithelia in association with invagination movements, so the proteins may have local as well as systemic functions. Similar proteins are found in mammals and may constitute a novel class of growth factors.

Amino Acid Sequence↗
PubMed1999

Scintigraphic evidence for a specific long-chain fatty acid transporting system deficit and the genetic background in a patient with hypertrophic cardiomyopathy.

The mechanism of cardiac uptake of long-chain free fatty acids has not been fully determined. We encountered a hypertrophic cardiomyopathy patient who showed a lack of cardiac uptake of 2 different types of long-chain fatty acid analogues on the scintigraphic images. Flow cytometric analysis revealed no platelet or monocyte CD36 molecule expression (type I CD36 deficiency) and his CD36 gene showed homozygous mutation for 478C to T substitution, leading to an abnormal CD36 amino acid sequence. These findings strongly suggest that a specific transporting system rather than a simple diffusion is commonly involved in the cardiac uptake of long-chain free fatty acids in humans, and that the CD36 protein is the most likely candidate for the specific transporter and to explain scintigraphic defects on fatty acid imaging.

Adult↗
PubMed1999

Prognostic significance of the pattern of multivessel spasm in patients with variant angina.

Multivessel spasm in variant angina is believed to be a major prognostic factor. Three patterns of multivessel spasm have been detected: (1) spasm at different sites on different occasions (migratory spasm); (2) spasm sequentially affecting 2 different sites (sequential spasm); and (3) simultaneous spasm at more than 1 site (simultaneous spasm). The present study investigated the prognosis based on this factor for variant angina without fixed coronary stenosis and examined the influence of multivessel spasm on cardiac events. Twenty-six patients were diagnosed as having variant angina without fixed coronary stenosis using 12-lead 24-h ECG recording system and coronary cineangiography. These patients were followed up prospectively for 57.1+/-7.6 months. Of the 26 patients 13 had single-vessel spasm, 6 had migratory multivessel spasm angina, and 7 showed sequential and/or simultaneous multivessel spasm angina. The survival free of serious cardiac events and of all cardiac events was significantly lower for patients with sequential and/or simultaneous multivessel spasm than for those with migratory multivessel spasm (p<0.05, p<0.05), whereas for patients with migratory multivessel spasm the difference comparison with single-vessel spasm did not attain statistical significance (p = ns, p = ns). The results of this study suggest that there seems to be a high-risk subgroup (i.e., sequential and/or simultaneous multivessel spasm) among patients with variant angina.

Aged↗
PubMed1999

Comparisons between hemodynamics, during and after bathing, and prognosis in patients with myocardial infarction.

The purpose of this study was to establish the safest way to bathe patients with myocardial infarction (MI) through measuring the hemodynamics during and after bathing. Seventy patients with MI were bathed supine in a Hubbard tank filled with 42 degrees C tap water for 5 min. The subjects were divided into 2 groups depending on their hemodynamic values 10 min after bathing: pulmonary capillary wedge pressure unchanged even after bathing (group A), and decreased pressure after bathing (group B). The left ventricular ejection fraction of group B was significantly higher than that of group A: 53.6% vs. 39.7%, respectively (p<0.01). The physical work capacity of group B was significantly higher at 5.6 METs, than that of group A with 4.5 METs (p<0.05). During the average of their 37-month follow-up period, there were 3 cardiac events in group B and 6 in group A. There were 2 cardiac events during bathing, both of which occurred in group A. When patients with MI take a bath, it is essential to closely monitor them, especially to those patients with lower cardiac function, because they have a higher possibility of a cardiac event.

Aged↗
PubMed1999

Dual-chamber pacing in hypertrophic obstructive cardiomyopathy: a comparison of acute and chronic effects.

This study describes the acute and chronic effects of dual-chamber (DDD) pacing in 14 consecutive patients with hypertrophic obstructive cardiomyopathy (HOCM), whose symptoms were refractory to drug therapy. Although left ventricular (LV) outflow tract pressure gradients diminished from 106+/-47 to 62+/-33 mm Hg (p<0.001) by temporary pacing, the residual pressure gradients were >30 mm Hg in the majority of those with concomitant reductions in cardiac output. The DDD pacing was judged as insufficient by the acute study in the majority of patients. A dual-chamber pacemaker was, however, implanted in 11 patients, and the chronic pacing effects were evaluated. All symptoms (syncope, fainting, palpitation and dyspnea) subsided within 1 month. Left ventricular outflow tract pressure gradients diminished from 99+/-56 to 21+/-13 mm Hg (p<0.004) at 1 week after, and to 17+/-12 mm Hg (p<0.002) at 1 year after the implantation, as measured by Doppler echocardiography. Echocardiogram showed disappearance of the systolic anterior motion of the mitral valve, and significant regression of the septal hypertrophy (from 18.5+/-4.3 to 15.7+/-4.1 mm, p<0.04). There was no significant correlation between the acute and chronic pacing effects in the reduction of the pressure gradients or symptomatic improvement. These results suggest that DDD pacemaker implantation is an effective treatment without any serious risks for patients with drug-refractory HOCM. The chronic-pacing effect in the reduction of the pressure gradient, the regression of hypertrophy and symptomatic improvement cannot be predicted by the assessment of temporary DDD pacing.

Adult↗
PubMed1999

The effect of tulobuterol tape on histamine-induced bronchoconstriction in conscious guinea pigs: long duration of action.

The objective of the present study was to determine the action duration of tulobuterol tape within a 24-hr period in conscious guinea pigs. The bronchoconstriction induced by histamine-inhalation was significantly inhibited by tulobuterol tape in comparison with its placebo tape 8 and 12 hr after binding, and the inhibitory rate was 50+/-11% and 35+/-13%, respectively. Twenty-four hours after binding, the inhibitory effect of tulobuterol tape gradually diminished, but the inhibitory rate was maintained at 30+/-14%. These results suggest that tulobuterol tape has a long lasting bronchodilatory action.

Administration, Cutaneous↗
PubMed1999

[Prophylaxis of recurrence in superficial bladder carcinoma by intravesical chemotherapy--comparative study between instillation of combined double anticancer agents and single anticancer agent].

We performed a study to compare the usefulness of double or single anticancer agents in the prophylactic treatment after the transurethral resection (TUR) of superficial bladder cancer. We experienced 127 superficial bladder cancer cases. Of these cases, 42 were treated with intravesical adriamycin (ADR) and peplomycin (PEP), 56 with ADR, PEP, epirubicin (epi-ADR) or pirarubicin (THP) only, and the remaining 29 with TUR only. Nonrecurrence rates were significantly higher in the intravesical treated cases than in the cases with TUR only, and also significantly higher in the cases treated with ADR and PEP than the other treated cases. We concluded that intravesical chemotherapy with combined agents was more effective than with a single agent.

Administration, Intravesical↗
PubMed1999

CD36 mediates long-chain fatty acid transport in human myocardium: complete myocardial accumulation defect of radiolabeled long-chain fatty acid analog in subjects with CD36 deficiency.

Long-chain fatty acids (LCFA) are the major energy substrate for heart and their oxidation is important for achieving maximal cardiac work. However, the mechanism of uptake of LCFA by myocardium has not been clarified. We previously reported that bovine myocardial LCFA transporter has a sequence homology to human CD36. Clinically, total defect of myocardial uptake of radiolabeled long-chain fatty acid analog [123I-BMIPP: Iodine-123 15-(p-iodophenyl)-(R,S)-methylpentadecanoic acid] has been reported in some restricted cases, but the etiology has not been clarified. In the present study, we analyzed CD36 expression and CD36 gene in subjects who showed total lack of myocardial 123I-BMIPP accumulation, and, vice versa, evaluated myocardial 123I-BMIPP uptake in subjects with CD36 deficiency. Four unrelated subjects were evaluated, Two were found to have negative myocardial LCFA accumulation by 123I-BMIPP scintigraphy, after which the expression of CD36 on their platelets and monocytes was analyzed. Remaining two subjects were identified as CD36 deficiency by screening, then 123I-BMIPP scintigraphy was performed. Expression of CD36 on platelets and monocytes was measured by flow cytometric analysis. The molecular defects responsible for CD36 deficiency was detected by allele-specific restriction enzyme analysis. CD36 expression was totally deficient in all 4 subjects on both platelets and monocytes. Two subjects were homozygous for a 478C-->T mutation. One was heterozygous for the dinucleotide deletion of exon V and single nucleotide insertion of exon X, and remaining one was considered to be heterozygous for the dinucleotide deletion of exon V and an unknown gene abnormality. All cases demonstrated a completely negative accumulation of myocardial LCFA despite of normal myocardial perfusion, which was evaluated by thallium scintigraphy. In addition, all cases demonstrated apparently normal hepatic LCFA accumulation Thus, these findings suggested that CD36 acts as a major myocardial specific LCFA transporter in humans.

Aged↗
PubMed1999

[Molecular mechanisms of the pathway formation in the fetal rat cerebral neocortex].

Neural cell adhesion molecules (NCAMs), L1 and TAG-1, which are prominently expressed in the developing nervous system, have been shown to promote axonal growth and bundle formation of central neurons in vitro. In the cerebral neocortex of fetal rats, immunoreactions of L1 and TAG-1 were specifically localized on thalamic afferent axons and cortical efferent axons, respectively. L1-bearing thalamocortical axons preferentially extended in the subplate of the cortical anlage where neurocan, a brain-specific chondroitin sulfate proteoglycan (CSPG), was prominently expressed. In contrast, cortical efferent axons immunoreactive for TAG-1 did not enter the subplate and run in the intermediate zone where neurocan expression was less abundant. In addition, TAG-1-bearing axons extensively invaded regions expressing another type of brain-specific CSPG, phosphacan. In the cell culture system, neurite outgrowth of TAG-1-transfected PC 12 D cells was remarkably inhibited on the neurocan substrate, while the outgrowth on phosphacan substrate was significantly promoted. Although both L1 and TAG-1 have been reported to bind both neurocan and phosphacan in vitro, interactions between NCAMs and CSPGs in vivo indicate more complicated patterns than previously thought. Thus, the present results suggest that various patterns of functional correlation between NCAMs and CSPGs play important roles in the pathway formation of the rat cerebral neocortex.

Animals↗
PubMed1999

[Direct Gram staining of blood culture sample enabled the early diagnosis of brain abscess due to Listeria monocytogenes].

A 58 year old woman had a long history of immunocompromised state. Since age 28 she had multiple endocrine neoplasm type 2A: her thyroid gland and bilateral adrenal glands were removed because of pheochromocytoma and thyroid medullary carcinoma. Corticosteroid and levothyroxine were supplemented. At age 57 she was afflicted with systemic lupus erythematodes and nephrotic syndrome. Prednisolone therapy was started. Two months later she developed fever, lethergy, headache and left hemiparesis. MRI revealed multiple ring-enhancing lesions in the right cerebrum. CSF was negative for microorganisms. Blood culture hemolysed after 24 hours. Direct gram staining of the blood culture sample revealed gram-positive short rods without spore, suggested listeria. This enabled prompt initiation of high dose penicillin therapy before the official report of listseria infection. Neurological abnormality including left hemiparesis disappeared completely within one month. Enhancement of abscess wall decreased every month, but it persisted for five months despite continuous intravenous penicillin therapy. Listeria monocytogenes is well-recognized as an opportunistic pathogen. It requires prolonged therapy with antibiotics, since it is the intracellular organism. Monitoring of the brain abscess wall by the enhanced MRI is useful to determine the completion of therapy. Since listerial contamination is common among raw meat and unpasteurized milk, immunocompromised patients should be alarmed not to eat uncooked food products.

Bacteriological Techniques↗
PubMed1999

The historical study of an ethics for American pharmacists.

The Code of Ethics for pharmacists clarifies the standards of professional conduct. The code should be positively enforced in every country, and must play its role as the conduct standard for pharmacists at all times. American pharmacists did not suddenly become ethical in the 1980s. An appreciation of the importance of professional ethics has a long history starting when the Philadelphia College of Pharmacy adopted a Code of Ethics in 1848. Since the first legislation of the American Pharmacy Code of Ethics as far back as 1852, the code has been revised in 1922, 1952, 1969, 1981 and 1994. The term of between revisions has gotten shorter over the years, reflecting the change in the status and the proficiency of pharmacists in 146 years. Its historical meaning is quite significant.

Ethics, Pharmacy↗
PubMed1998

Neuronal src and trk a protooncogene expression in neuroblastomas and patient prognosis.

Neuroblastomas present a wide variety of clinical and biological behaviors, which are reflected by the heterogeneous expressions of protooncogenes related to the neuronal differentiation and amplification of the N-myc gene. High expression of trk A and Ha-ras in neuroblastomas has been shown to be associated with an excellent patient outcome. We have previously reported that neuron-specific src mRNA was increased in chemically differentiated neuroblastoma cell lines and in clinically observed neuroblastomas without N-myc amplification. In the present study, to clarify both the value of neuronal c-srcN2 expression as a prognostic indicator and the significance of the coexpression of these protooncogenes, we examined the expression of 3 alternatively spliced src, trk A and Ha-ras in neuroblastoma tissues from 60 patients by competitive RNA-polymerase chain reaction (PCR). The results indicate that protooncogene expression in neuroblastomas correlated with a favorable outcome for c-srcN2 and trk A. N-myc gene was amplified exclusively in tumors with low levels of trk A. Low expression of c-srcN2 and trk A might thus characterize different aggressive phenotypes due to different signal transduction pathways of neural differentiation in neuroblastoma. The combined analyses for c-srcN2 and trk A expression by RNA-PCR should provide information about the biological phenotype of a neuroblastoma within a short period of time after obtaining tumor material.

Genes, myc↗
PubMed1998

Coordinate expression of L1 and 6B4 proteoglycan/phosphacan is correlated with the migration of mesencephalic dopaminergic neurons in mice.

Mesencephalic dopaminergic (DA) neurons of mice are generated from embryonic day 10 to 12 (E10-12) in the ventricular zone of the mesencephalon. They first migrate toward the ventral mesencephalon, and then turn laterally, or tangentially, in the basal part of the mesencephalon. With immunohistochemical analysis of E10-E15 ICR mice, we found that cell adhesion molecule L1 was transiently expressed on the median part of tangential fibers coincident with the lateral migration of DA neurons from E11 to E13, when neurons move along the tangential fibers toward their final destinations: the reticular formation, the substantia nigra pars compact, and the ventral tegmental area. While L1 expression was not observed in DA neurons, they expressed a chondroitin sulfate proteoglycan, 6B4 proteoglycan/phosphacan, which has been shown to bind to L1/Ng-CAM in vitro. These results suggest that the heterophilic interaction between 6B4 proteoglycan on the neurons and L1 on the fibers is involved in the lateral migration of mesencephalic DA neurons in mice.

Animals↗