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Biomedical subjects

R Hayashi

Publications and source records attributed to R Hayashi.

At least 109 records · Page 6Linked to original sources
PubMed1998

Bradykinin stimulates interleukin-8 production by human lung fibroblasts.

Bradykinin (BK) is a potent inflammatory mediator that is generated from kininogens by the actions of plasma and tissue kallikreins. Lung fibroblasts have the potential to participate in the inflammatory responses by releasing proinflammatory cytokines in response to a variety of stimuli. We postulated that human lung fibroblasts might produce interleukin-8 (IL-8) in response to BK stimulation. The present study showed that BK stimulated human lung fibroblasts to produce IL-8 in a dose- and time-dependent manner. Furthermore, Northern blot analysis showed that BK increased IL-8 mRNA expression. The stimulatory effect of BK on IL-8 production was detected at the concentration of 10 nm, and the maximal stimulation was achieved with 100 to 1000 nm. Phorbol 12-myristate 13-acetate pretreatment diminished the ability of BK to stimulate IL-8 production. In addition, GF109203X, a selective protein kinase C inhibitor, blocked BK-induced IL-8 production. These observations suggest that the stimulatory effect of BK on IL-8 production by lung fibroblasts is, at least partially, mediated through protein kinase C. These data suggest that BK may be involved in the inflammatory reaction leading to interstitial lung disorders through stimulating IL-8 production by lung fibroblasts.

Blotting, Northern↗
PubMed1998

Effects of thyroid hormone on catecholamine and its metabolite concentrations in rat cardiac muscle and cerebral cortex.

Clinical and experimental data suggest that thyroid hormone affects the actions of catecholamine (CA). However, the serum or tissue levels of CA during thyroid disorders have not been well defined. Accordingly, we investigated the levels of CA and their metabolites in the cardiac muscle, the cerebral cortex, and the plasma of rats with hyperthyroidism and hypothyroidism versus euthyroid animals. The Neurochem analyzer system (ESA, Inc., Bedford, MA) was used in such determinations. The cardiac muscles of hyperthyroid rats exhibited a 16% decrease in the levels of 1-dopa, 3-methoxytyramine (3-MT) and homovanillic acid (HVA) as compared with those in euthyroid rats. The levels of norepinephrine (NE) in cardiac muscle of these rats increased significantly (5.2-fold) relative to the levels in euthyroid rats. NE was undetectable in the cardiac muscles of the hypothyroid rats. Epinephrine (E) and dopamine (DA) were not detected in the cardiac muscles of the rats with either thyroid disorder. Levels of E and 3,4-dihydroxymandelic acid (DOPEG) were detected only in the cerebral cortex of hyperthyroid rats. The cerebral cortex levels of 3-methyoxytyramine (3-MT), 3,4-dihydroxyphenylacetic acid (DOPAC), metanephrine (MN), and homovanillic acid (HVA) were all significantly increased in the hyperthyroid versus the euthyroid rats. The cerebral cortex levels of DA, NE, normetanephrine (NMN), and VMA in the hyperthyroid rats all showed a significant decrease. Levels of NE, NMN, and DOPAC in the cerebral cortex increased significantly in the hypothyroid rats. The level of VMA was undetectable in cerebral cortex of such animals. Data from studies on cardiac muscle and cerebral cortex indicate that the changes in CA and CA metabolites are responsible in part for the cardiovascular and the central nervous system symptoms observed in hyperthyroidism and hypothyroidism.

Animals↗
PubMed1998

Bovine spleen cathepsin A: characterization and comparison with the protective protein.

Cathepsin A was purified approximately 550-fold with an overall yield of 4% from bovine spleen crude extracts by successive chromatographies on DEAE-Sephadex A-50, phenyl-Toyopearl 650C, and Con A-agarose. PAGE of the purified enzyme without 2-mercaptoethanol revealed an apparent molecular size of 110 kDa, and SDS-PAGE with 2-mercaptoethanol gave two polypeptide bands corresponding to 32 and 25 kDa and without 2-mercaptoethanol a single polypeptide 52 kDa band. These results indicate that the enzyme has an (alpha beta)2 tetrameric structure in which the alpha (32 kDa) and beta (25 kDa) subunits are linked by disulfide bond(s). The enzyme exhibited peptidase activities, hydrolyzing various Z-dipeptides with optimum pHs between 5.0 and 5.8. The hydrolytic rate for Z-Phe-Ala was 15 times higher than that for Z-Glu-Tyr, the traditional cathepsin A substrate. The enzyme also catalyzed the hydrolysis of the C-terminal amino acids of RCM-RNase A and showed esterase activity toward BTEE at pH around 7.5. DFP and TPCK completely inhibited both peptidase and esterase activities, and [1,3-3H]DFP was bound to the alpha subunit. All these results support the fact that the enzyme is a serine carboxypeptidase. The N-terminal amino acid sequences of the alpha and beta subunits are highly homologous to those of the human protective protein in galactosialidosis, strongly supporting the identity between cathepsin A and the protective protein.

Amino Acid Sequence↗
PubMed1998

Role of Phe120 in the activity and structure of bovine pancreatic ribonuclease A.

Phenylalanine120 is a candidate residue juxtaposing catalytic His12 and His119 in ribonuclease A (RNase A). To clarify its role in construction of the catalytic center, Phe120 was replaced by alanine, tryptophan, leucine, or glutamic acid by site-directed mutagenesis. The transphosphorylation and hydrolysis activities of the mutant RNase As, respectively, toward cytidinyl 3',5' adenosine (CpA) and cytidine 2',3' cyclic monophosphate (C>p) were compared with those of the wild type enzyme. The Km values of the two reactions increased markedly with slight changes in the Kcat values. The pKe values of His12 and His119 in the wild type and mutant enzymes, estimated from the pH dependence of the kcat/Km values, showed little change. The rate of carboxymethylation was reduced markedly by the mutations. The Ki values of the phosphate anion as to hydrolysis activity increased only slightly when Phe120 was replaced by leucine, tryptophan, or alanine. These findings suggest that Phe120 participates in the binding of the substrate, juxtaposing His12 and His119, and in stabilizing the transition state intermediate in the hydrolysis reaction. Furthermore, the decreases in the thermal denaturation temperatures of all the mutants, particularly F120E, indicate that Phe120 also helps maintain the conformational stability of RNase A.

Animals↗
PubMed1998

Proton-relay system of carboxypeptidase Y as a sole catalytic site: studies on mutagenic replacement of his 397.

His397 was replaced with alanine by site-directed mutagenesis of the cloned PRC1 gene in order to confirm the role of this residue in the proton-relay system of carboxypeptidase Y (CPY). The expressed and purified H397A showed a CD spectrum almost identical to that of the wild type enzyme, but its heat stability and conformation on heating differed somewhat. Kinetic analysis showed that the kcat values of the purified H397A toward the peptide substrates, Z-Phe-Leu and Z-Gly-Phe, were reduced to approximately 4 x 10(-5)-fold, whereas the Km values remained almost unchanged. The activity of the H397A preparation with the ester substrate, Ac-Phe-OEt, was negligible. The low activity of our H397A was lost on treatment with DFP and Z-Phe-CH2Cl, site-specific inhibitors, respectively, for Ser146 and His397, and with the HgCl2 and PCMB, SH-reagents for Cys341. After treatment with these inhibitors, the kcat value for the H397A preparation toward Z-Phe-Leu decreased 1 x 10(3)-fold or more. The value was approximately 10(-8) for the wild type enzyme. This level of activity is 10(3)-fold lower than the reported value for the same mutant of CPY [Carlsberg Res. Commun. 54, 165-171 (1989)], and more than 10-fold lower than the values for the corresponding His-to-Ala mutants of trypsin [J. Am. Chem. Soc. 114, 1784-1790 (1992)] and subtilisin [Nature 332, 564-568 (1988)]. These findings, together with the pH profiles and chromatographic behavior, are evidence that the low activity of the H397A preparation is due to contamination by wild type CPY. The decreased kcat value of our H397A mutant is the lowest reported among the corresponding histidine mutants of serine proteases. We conclude that the proton-relay system composed of Ser146 and His397 is the sole catalytic center of CPY, and that its destruction leads to complete inactivation.

Binding Sites↗
PubMed1998

Vitamin E and coenzyme Q concentrations in the thyroid tissues of patients with various thyroid disorders.

To clarify the different roles of free radical scavenging systems in various thyroid disorders, we measured the levels of alpha-, beta-, and gamma-tocopherols and coenzyme Q in the thyroid tissues of patients with thyroid tumors and Graves' disease using high-performance liquid chromatography. The levels of alpha-tocopherols and gamma-tocopherols in the thyroid tissue of patients with papillary carcinoma and the level of gamma-tocopherol in the thyroid tissue of patients with malignant lymphoma were elevated compared with those in normal thyroid tissues. The level of coenzyme Q was reduced in the thyroid tissue of patients with Graves' disease and follicular and papillary thyroid carcinomas. These findings imply that vitamin E and coenzyme Q as scavengers play some role in thyroid follicular cell hyperfunction or dysfunction.

Graves Disease↗
PubMed1998

Laryngeal preservation surgery using a free flap patch following resection of a carcinoma of the posterior wall of the oropharynx.

A carcinoma originating from the posterior wall of the oropharynx is not common, and radiotherapy has been used for years in this event without acceptable success. A free flap patch was used in 4 patients to reconstruct the defect after resection of a T2 or T3 carcinoma on the posterior wall of the oropharynx without laryngectomy. The free flaps used were the radial forearm and the free jejunal patch in 2 patients each. There was no flap loss, and successful laryngeal preservation was obtained in 3 of 4 patients. Laryngeal preservation surgery using a free flap patch proved very useful in selected patients with carcinoma of the posterior wall of the oropharynx. Based on our clinical experience, the free jejunal patch seems superior to the free forearm flap with regard to postoperative functional results.

Aged↗
PubMed1998

Accumulation of acid-fast lipochrome bodies in glial cells of the midbrain nigral lesion in Parkinson's disease.

To confirm or refute the proposed link between nocardiae and Parkinson's disease (PD), we investigated the presence of acid-fast spherical structures similar to filterable nocardiae at the midbrain nigral lesions of three patients with PD. Many clusters of acid-fast lipochrome bodies were dense around blood vessels in the two patients with Hoehn and Yahr stage II and III PD. These clusters were present in the vicinity of melanin-pigmented neurons in the three PD patients studied. Examination of adjacent hematoxylin-and-eosin-stained sections indicated that they consisted of yellow-green granules, bodies, and aggregates in ballooned glial cells. On the other hand, no clusters of acid-fast lipochrome bodies were observed at the compacta region of three control patients. Our results suggest that the immunological and genetic relationship between the acid-fast lipochrome bodies and filterable nocardiae should be investigated.

Aged↗
PubMed1998

Quantitative differentiation of both free 3'-OH and 5'-OH DNA ends between heat-induced apoptosis and necrosis.

Cell death is roughly categorized as either apoptosis or necrosis. For better understanding of the differences in DNA cleavage between them, we performed quantitative analysis of both the 3'-OH and the 5'-OH ends of DNA strand breaks via in situ nick-end labeling (ISEL) combined with transmission electron microscopy (TEM) of both heat-induced apoptosis and necrosis in mouse B-cells derived from a lymphoma cell line. To detect the 5'-OH ends, the 3'-P ends located on the opposite side holding the 5'-OH ends were dephosphorylated into 3'-OH ends with alkaline phosphatase. As assessed by statistical analysis of both the 3'-OH and the 5'-OH ends, their labeling densities were significantly higher in both the apoptotic and the necrotic cells in the early stage than in control cells. The labeling densities increased during the apoptotic and necrotic processes, except for a decrease in the density of the 3'-OH ends in necrotic cells in the late stages. Therefore, DNA degradation in both necrosis and apoptosis provides early evidence for these processes, and both apoptosis and necrosis may share at least the first steps of DNA degradation pathways.

Animals↗
PubMed1998

Successful treatment of anomalous origin of the left coronary artery from the pulmonary artery in a 5-week-old male infant.

A 5-week-old male infant who was referred to our hospital because of tachypnea and poor feeding. An electrocardiogram showed a deep Q wave in lead aVL, negative T waves in leads I, II, III, aVF and V6 and a positive T wave in VL. Echocardiography revealed severely impaired left ventricular function. Aortography confirmed with a diagnosis of anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA). Takeuchi's procedure was performed and the patient maintained postoperatively on assisted circulation for 7 hours even though sternal closure delayed until 7 days post operatively. His left ventricular function showed and marked improvement gradually.

Assisted Circulation↗
PubMed1998

Utility of measuring serum parathyroid hormone-related protein concentration in leukemic patients with hypercalcemia for assessing disease status.

OBJECTIVE: To evaluate serum parathyroid hormone-related protein (PTHrP) as a marker of hypercalcemia in leukemic patients. DESIGN AND METHODS: We measured the serum levels of PTHrP, lactate dehydrogenase (LDH) and calcium in three patients with hypercalcemia due to leukemia. RESULTS: Serum levels of PTHrP, LDH and calcium were elevated at admission in all patients, and these levels were reduced to within the normal range after chemotherapy. However, normalization of serum PTHrP concentration occurred more rapidly than normalization of serum LDH levels after chemotherapy. The increase in serum PTHrP concentration accompanied leukemic cell proliferation and preceded the increases in serum LDH and calcium. Serum LDH concentration increased, but serum PTHrP concentration did not after administration of granulocyte colony-stimulating factor. CONCLUSION: These findings suggest that serum PTHrP may be a more useful marker than serum LDH or calcium in assessing the status of leukemic patients with hypercalcemia.

Biomarkers↗
PubMed1998

Familial hemiplegic migraine with irreversible brain damage.

Familial hemiplegic migraine (FHM) is an autosomal dominant syndrome characterized by recurrent episodes of varying degrees of hemiparesis associated with migraine. The aura including hemiparesis may be prolonged and in severe attacks may often be associated with confusion or coma. We describe a case of FHM whose aura was atypically prolonged and resulted in irreversible brain deficit which on magnetic resonance imaging (MRI) was suggestive of cortical hyperperfusion. A subsequent MRI showed left brain atrophy.

Adult↗
PubMed1998

Efficacy of a low-dose subcutaneous lisuride infusion in Parkinson's disease.

Five parkinsonian patients with motor fluctuations and dyskinesia after long-term treatment with levodopa were treated with subcutaneous lisuride infusion (0.24-0.42 mg/day) together with oral levodopa for a mean period of 27 (range 13-36) months. All 5 patients showed marked initial improvement in mobility. Mild psychiatric side effects were observed in three patients; however, these side effects disappeared with reduction in the dosage of lisuride to 0.06 mg per day without a significant increase in motor fluctuations. A low dose of subcutaneous lisuride infusion with oral levodopa is an effective treatment for fluctuations of motor performance in parkinsonian patients without adverse psychiatric effects.

Administration, Oral↗
PubMed1998

Chest radiography as a predictor of outcome in posttransplantation lymphoproliferative disorder in lung allograft recipients.

OBJECTIVE: The radiologic findings of posttransplantation lymphoproliferative disorder in lung transplant recipients have received little attention compared with the findings for recipients of other solid organ transplants. We describe the intrathoracic findings and explore whether the radiographic presentation can predict outcome. MATERIALS AND METHODS: Twenty-six patients (mean age, 32 years; range, 2-63 years; 18 female, eight male) with histologically proven lymphoproliferative disorder were identified from 518 lung transplantation patients, a 5.0% frequency. Chest radiographs, obtained within 1 week of diagnosis, were compared with baseline posttransplantation radiographs for all 26 patients and with chest CT scans for 20 patients. RESULTS: The interval between transplantation and diagnosis ranged from 6 weeks to 7 years (mean, 16 months; median, 6 months). The thorax was involved in 18 (69%) of 26 patients. A new chest radiographic abnormality was present in all 18 patients and provided the first indication of disease in 14 (78%) of 18 patients. The most common finding was a solitary pulmonary nodule, seen in nine (50%) of 18 patients. Other findings included multiple nodules, multifocal alveolar infiltrates, and hilar and mediastinal adenopathy. CT scans detected additional nodules and lymph nodes but did not show occult disease in any case that appeared normal on radiography. Eight (89%) of nine patients with solitary pulmonary nodules at presentation were alive 1 year after diagnosis, compared with six (35%) of 17 patients with other presentations (p < .01). CONCLUSION: Thoracic manifestations are present in most lung transplant recipients with lymphoproliferative disorder. Patients with solitary nodules have a better outcome in the first year after diagnosis than do patients with other presentations.

Adolescent↗
PubMed1998

[Surgical treatment of differentiated thyroid cancer with tracheal invasion].

Thirty patients with tracheal invasion of differentiated thyroid cancer underwent partial resection of the tracheal wall between 1978 and 1996 at National Cancer Center Hospital. In most cases, the defect in the tracheal wall was reconstructed secondarily using a local flap. This method was easy in comparison with end-to-end anastomosis of the trachea following circumferential resection of the wall. Partial resection of the tracheal wall proved to be a effective treatment for thyroid cancer invasion of the tracheal, because of low incidence of local recurrence. When the defect of the tracheal wall was too large to be reconstructed using a local flap, hydroxylapatite was employed and good results were obtained.

Adult↗
PubMed1998

[Auditory evoked magnetic fields in patients of pure word deafness].

Auditory evoked magnetic fields (AEF) were recorded in 2 cases with pure word deafness. AEF examination were performed with a novel 129-channel vector neuromagnetic imaging system (SBI 100). The latency and the location of equivalent current dipole (ECD) of N100 m after 1,000 Hz tone burst stimulation, one of the most prominent peak of AEF, were evaluated. One patient, 59-year-old man, suffered from left putaminal hemorrhage and the other, 59-year-old man, had a history of bilateral putaminal hemorrhage. There was no N100 m detected in the left temporal lobe with the right ear stimulation in both patients. However normal N100 m was obtained in the right hemisphere with the left ear stimulation in both cases. And the position of ECD of N100 m in the right hemisphere were correctly superimposed on the Heschl gyrus in brain MRI. The pathophysiology of pure word deafness has been postulated that a disconnection between Wernicke area and bilateral auditory inputs played one of important roles in progression of pure word deafness. Because there was no pathological lesion in temporal lobe verified by MRI study in both patients, N100 m in the left could not be evoked due to interception of the auditory pathway to the Heschl gyrus, but not due to destruction of Heschl gyrus. AEF test is one of the most useful tools in order to estimate central auditory function in patients with pure word deafness.

Aphasia, Wernicke↗
PubMed1998

[A case of autosomal dominant, pure form spastic paraplegia with thinning of the corpus callosum].

Autosomal dominant hereditary spastic paraplegia (HSP) is genetically classified into three types, all of which are characterized by insidiously progressive spasticity of the lower extremities. Patients with a complicated form of autosomal recessive HSP associated with hypoplasia of the corpus callosum have been reported by Iwabuchi et al. Here we report a 64-year-old patient with a pure form of autosomal dominant HSP with thinning of the corpus callosum. He had been well until 12 years of age, when spasticity and weakness of the lower extremities began to develop. His symptoms gradually worsened and he had difficulty in walking at the age of 44. When he was 56 years old, he visited our hospital. Eleven family members over five generations have been affected, and anticipation, i.e., an apparent decrease in age of onset, has been observed. On admission, he had mild cataracts, equinovarus and pes cavus, and neurological examination revealed spastic paraplegia. However, the intelligence test was normal, and nystagmus, ataxia of the extremities, involuntary movement, orthostatic hypotension or urinary disturbance was not observed. Trinucleotide repeat diseases, such as Huntington's disease, spinocerebellar ataxia type 1, spinocerebellar ataxia type 2, Machado-Joseph disease and dentatorubral-pallidoluysian atrophy, were excluded by DNA analysis. Brain MRI at the age of 64 revealed marked thinning of the corpus callosum. We considered this patient had a pure form of HSP. However, thinning of the corpus callosum has never been reported in autosomal dominant HSP.

Adolescent↗