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Biomedical subjects

N Ohsawa

Publications and source records attributed to N Ohsawa.

At least 19 recordsLinked to original sources
PubMed2001

Pancreatic volume in type 1 and type 2 diabetes mellitus.

We measured pancreatic volume (PV) using helical computed tomography (CT) in 26 patients with type 1 diabetes mellitus (DM), 29 patients with type 2 DM, and 22 healthy individuals. We also evaluated the relationship between PV and the body surface area (BSA), established the pancreatic volume index (PVI) by dividing PV by BSA to correct PV for the body build, and examined its relationships with the duration of illness, serum C-peptide immunoreactivity level (CPR), and serum immunoreactive trypsin level (IRT). BSA and PV were correlated significantly (p<0.0001, r=0.645) in healthy individuals, and they were correlated also in the diabetic patients (p=0.0023, r=0.563 in type 1 DM; p=0.0346, r=0.392 in type 2 DM). PV was significantly smaller in the type 1 DM group than in the healthy group and type 2 DM group (p<0.001 for both). PVI was also significantly smaller in the type 1 DM group than in the healthy group and type 2 DM group (p<0.001 for both). PVI and IRT were significantly correlated in both DM groups (p<0.0001, r=0.732 in type 1 DM; p=0.0469, r=0.371 in type 2 DM). PVI was not correlated with the duration of illness or CPR. Helical CT was useful for the measurement of the pancreatic volume, and the pancreatic volume was reduced particularly in the patients with type 1 DM. A strong correlation was observed between PV and exocrine pancreatic function in type 1 DM, but the correlation between PV and exocrine pancreatic function was weak in type 2 DM.

Adult↗
PubMed2001

Physiological function of bromoperoxidase in the red marine alga, Corallina pilulifera: production of bromoform as an allelochemical and the simultaneous elimination of hydrogen peroxide.

The physiological function of vanadium-bromoperoxidase (BPO) in the marine red alga, Corallina pilulifera, has been characterized from the viewpoint of allelochemical formation. The algae emit bromoform (CHBr3) depending on the enzyme activity level in vivo (Itoh, N., Shinya, M., 1994. Seasonal evolution of bromomethanes from coralline algae and its effect on atmospheric ozone. Marine Chemistry 45, 95-103). We demonstrated that bromoform produced by C. pilulifera played an important role in eliminating epiphytic organisms, especially microalgae on the surface. Such data suggest a strong relationship between the coralline algae and the coralline flat (deforested area in the marine environment: called isoyake in Japanese). Lithophyllum yessoense, the main inhabitant of coralline flats in Japan, produced a lower level of CHBr3 than C. pilulifera, and showed BPO activity. On the other hand, the seasonal change of BPO activity in C. pilulifera in vivo was in proportion to superoxide dismutase (SOD) activity and in inverse proportion to catalase activity. The phenomenon implies that BPO could be a potential substitute for catalase, because the enzyme catalyzes an efficient Br(-)-dependent catalase reaction.

Benzopyrans↗
PubMed2001

Purification and characterization of a monohalomethane-producing enzyme S-adenosyl-L-methionine: halide ion methyltransferase from a marine microalga, Pavlova pinguis.

A monohalomethane-producing enzyme, S-adenosyl-L-methionine-dependent halide ion methyltransferase (EC 2.1.1.-) was purified from the marine microalga Pavlova pinguis by two anion exchange, hydroxyapatite and gel filtration chromatographies. The methyltransferase was a monomeric molecule having a molecular weight of 29,000. The enzyme had an isoelectric point at 5.3, and was optimally active at pH 8.0. The Km for iodide and SAM were 12 mM and 12 microM, respectively, which were measured using a partially purified enzyme. Various metal ions had no significant effect on methyl iodide production, suggesting that the enzyme does not require metal ions. The enzyme reaction strictly depended on SAM as a methyl donor, and the enzyme catalyzed methylation of the I-, Br-, and Cl- to corresponding monohalomethanes and of bisulfide to methyl mercaptan.

Chromatography↗
PubMed2000

Effects of interferon-alpha on peripheral neutrophil counts and serum granulocyte colony-stimulating factor levels in chronic hepatitis C patients.

Granulocytopenia is commonly observed in interferon-alpha (IFN-alpha) therapy. Granulocyte colony-stimulating factor (G-CSF) has been identified as a primary cytokine that regulates neutrophil production, but the kinetics of G-CSF in IFN-alpha-induced granulocytopenia remains unclear. We investigated the effects of IFN-alpha on serum G-CSF levels and peripheral neutrophil counts (NC) in 15 chronic hepatitis C patients treated with standard-dose (10 MU) recombinant IFN-alpha for 24 weeks by using a chemiluminescent enzyme immunoassay for G-CSF. The time course of change after a single IFN-alpha injection showed that mean serum G-CSF levels and NC increased significantly compared with pretreatment values (p < 0.05), and were statistically correlated (r = 0.914, p = 0.0015). On repeating IFN-alpha administration, this change gradually became unclear, and granulocytopenia occurred, accompanied by a significant increase in serum G-CSF (p < 0.01). Both values reached a plateau within 2 weeks after starting treatment, and recovered rapidly after the cessation of therapy. Although continuous administration of IFN-alpha caused a time-dependent granulocytopenia, our results suggest that a single injection of IFN-alpha would be a potent inducer of G-CSF and NC in vivo as a short-term effect and that there would be negative-feedback regulation between them during long-term IFN-alpha therapy.

Adjuvants, Immunologic↗
PubMed2000

Increased migration in late G(1) phase in cultured smooth muscle cells.

Migration and proliferation of smooth muscle cells (SMC) contribute to neointimal formation after arterial injury. However, the relation between migration and proliferation in these cells is obscure. To discriminate between migration and proliferation, we employed a migration assay of SMC at different phases of the cell cycle. Serum-deprived SMC were synchronized in different phases of the cell cycle by addition of serum for various periods of time. Migration induced by platelet-derived growth factor B-chain homodimer was maximal in SMC that were predominantly in the late G(1) (G(1b)) phase. In addition, in nonsynchronized SMC, 65-75% of SMC that had migrated were in the G(1b) phase. Phosphorylated myosin light chain was enriched around the cell periphery in SMC in the G(1b) phase compared with SMC in the other cell cycle phases. Interestingly, the Triton X-100-insoluble fraction of myosin was remarkably decreased in G(1b)-enriched SMC. These findings suggest that migratory activity of SMC may be coupled with the G(1b) phase. The phosphorylation and retention of myosin might explain some of the properties responsible for increased migration.

Actins↗
PubMed1999

The kinase inhibitor fasudil (HA-1077) reduces intimal hyperplasia through inhibiting migration and enhancing cell loss of vascular smooth muscle cells.

Smooth muscle cell (SMC) migration plays an important role in restenosis after angioplasty. Myosin phosphorylation is necessary for cell migration. Fasudil is an inhibitor of protein kinases, including myosin light chain kinase and Rho associated kinase, thereby inhibiting myosin phosphorylation, and it has been clinically used to prevent vasospasm following subarachnoid hemorrage. Based on these findings, we examined the anti-migrative action of fasudil. In SMC (SM-3), fasudil (1-100 microM) inhibited SMC migration in a dose-dependent manner (p < 0.001). Fasudil suppressed actin stress fiber formation dose dependently. In rabbit carotid artery, fasudil (10 mg/kg/day) markedly reduced intimal hyperplasia 14 days following balloon injury. Cell kinetic study showed that fasudil did not affect proliferation but enhanced cell loss in the media after injury. We concluded that fasudil reduced neointimal formation after balloon injury through both inhibiting migration and enhancing cell loss of medial SMC.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1999

Specific binding and effects of dehydroepiandrosterone sulfate (DHEA-S) on skeletal muscle cells: possible implication for DHEA-S replacement therapy in patients with myotonic dystrophy.

Dehydroepiandrosterone (DHEA) and its sulfate (DHEA-S) are the most abundant steroidal products and major circulating steroids in humans. The serum concentrations of DHEA-S are lower in patients with myotonic dystrophy (DM) than normal controls, and possible improvement of myotonia and muscle weakness was recently reported following DHEA-S replacement therapy. However, the molecular mechanism of action of DHEA-S remains unknown. To understand the reported anti-DM action of DHEA-S, we investigated DHEA-S binding in skeletal muscle cells in vitro. We identified two populations of DHEA-S binding sites (Kd = 5-9 microM and 35-40 microM) in C2C12 myocytes. Similar binding sites were also identified in human skeletal muscles. The Kd value of the high-affinity site was within the range of serum concentrations of DHEA-S in adult humans. Our results suggest that DHEA-S might act directly on skeletal muscles under normal physiological conditions in humans.

Animals↗
PubMed1999

Pulmonary diffusing capacity, serum angiotensin-converting enzyme activity and the angiotensin-converting enzyme gene in Japanese non-insulin-dependent diabetes mellitus patients.

We investigated the independent change in pulmonary diffusing capacity (DLCO) as one manifestation of pulmonary microangiopathy and to analyze the correlation between DLCO and serum ACE. We also examined the association between DLCO and the ACE genes. We examined pulmonary functions, especially %DLCO/VA (DLCO corrected by alveolar volume, percent predicted) in 54 NIDDM patients and 34 age-matched normal control subjects. Subjects were subdivided according to the degree of retinopathy. Serum ACE level was assayed by a colorimetric method in 54 patients and an insertion/deletion polymorphism in the ACE gene was amplified using the polymerase chain reaction in 52 of the 54 patients. There was a significant reduction of %DLCO/VA (percent predicted P < 0.05) in diabetic patients. In the proliferative retinopathy (PDR) group. %DLCO/VA was significantly (P < 0.05) lower than in the no diabetic retinopathy (NDR) and simple diabetic retinopathy (SDR) groups. Although the levels of serum ACE were within normal ranges in all diabetic groups, %DLCO/VA was negatively correlated with serum ACE values (r = 0.49, P < 0.0002, y = -1.4x + 109.3). Differences among DD, ID and II type of the ACE gene, with respect to the incidence of abnormal values of each clinical parameter, were not significant. DLCO was significantly reduced in patients with PDR and the serum ACE was significantly related to impaired DLCO. Our study suggests the existence of microangiopathic involvement of pulmonary vessels in NIDDM patients.

Colorimetry↗
PubMed1999

Scores of coronary calcification determined by electron beam computed tomography are closely related to the extent of diabetes-specific complications.

This study was aimed at investigating the degree of calcification of coronary arteries in type II diabetes mellitus for the purpose of examining as risk factors for coronary disease as well as parameters of diabetic complications. One hundred and three patients with type II diabetes were studied by the newly developed noninvasive technology of electron beam computed tomography, in which the degree of calcification was expressed as coronary calcification scores. The mean +/- SE value of coronary calcification scores were 247.5 +/- 48.1, which were significantly greater than the control patients without diabetes (148.9 +/- 48.3, p<0.05). In the diabetics, the coronary calcification scores had a significant (p < 0.01) correlation with patient age and duration of diabetes. The scores also had a significant (p<0.05) difference between patients who did and did not smoke cigarettes, and between patients with and without hypertension. The scores were significantly (p < 0.01) different between patients with and without hypertension. The scores were significantly (p < 0.01) different between presence and absence of diabetes-specific complications including retinopathy, neuropathy, and nephropathy. In a subgroup of patients without any signs of coronary disease, the scores showed a significant (p<0.01) difference between presence and absence of diabetes-specific complications, but no significant difference with smoking or hypertension. These data suggest that the extent of coronary calcifications and the development of ischemic heart disease seem to be closely related to the association of diabetic complications. Use of electron beam computed tomography seems to be useful in obtaining the information to predict future development of diabetic-specific complications.

Age Factors↗
PubMed1999

Differences between changes in serum thyrotropin-binding inhibitory antibodies and thyroid-stimulating antibodies in the course of antithyroid drug therapy for Graves' disease.

There has recently been controversy regarding whether the measurement of thyrotropin-binding inhibitory antibodies (TBIAb) is useful in the management of Graves' disease. Another method of assessing Graves' disease by measuring adenylate cyclase activity in thyroid cells, known as thyroid-stimulating antibodies (TSAb), differs from TBIAb not only in terms of assay but also in immunoglobulin type according to recent studies. In this study, the concentrations of TBIAb and TSAb were compared in serial serum samples collected from 29 patients with Graves' hyperthyroidism during 12 months of antithyroid drug therapy. Before therapy, there was a correlation between TBIAb and TSAb (r = 0.59). The radioactive iodine uptake (RAIU) was not significantly correlated with either TBIAb or TSAb (r = 0.20 and r = 0.29, respectively), and the serum free thyroxine (FT4) concentration was also not significantly correlated with either TBIAb or TSAb (r = 0.06 and r = 0.22, respectively). In patients with Graves' ophthalmopathy, TSAb levels were higher than in patients without ophthalmopathy (1015%+/-851% vs. 456%+/-323%, p<0.01), but the TBIAb levels were not significantly different. After antithyroid treatment, TBIAb did not decrease significantly (from 42.1%+/-20.8% to 20.5%+/-19.5%, p = 0.29). On the other hand, TSAb was significantly decreased after 12 months of treatment (from 649%+/-611% to 294%+/-205%, p< 0.05). These findings indicate that TBIAb and TSAb are not identical, and that TSAb has a closer relationship to thyroid function than TBIAb. In the clinical setting, determination of the serum TSAb level may provide a more accurate index of the thyroid status in Graves' disease patients receiving antithyroid therapy.

Adult↗
PubMed1999

Acute and early effects of triiodothyronine administration on serum markers of bone and mineral metabolism.

There have been few studies on acute changes of bone metabolism in humans by thyroid hormone. This study aimed to examine the effects of triiodothyronine on serum markers of bone and mineral metabolism during a 7-d course of daily 75 microg therapy in 14 normal volunteers by drawing blood on 1, 2, 3, 5, and 7 d of therapy. Serum calcium concentrations did not significantly change during the course of therapy, while serum phosphorus concentrations were significantly (p < 0.05) decreased from 3.21 +/- 0.43 mg/dL (mean +/- SD) to 2.85 +/- 0.46 mg/dL on the 7th d. Serum PTH concentrations were significantly decreased from 339 +/- 116 pg/mL to 316 +/- 29 pg/mL. Serum concentrations of alkali-phosphatase and bone-specific alkali-phosphatase were not significantly changed, but serum osteocalcin concentrations were significantly increased from 5.71 +/- 1.98 mg/dL to 6.73 +/- 2.24 mg/dL. Serum carboxy-terminal propeptide of type I collagen concentrations were significantly decreased from 137.8 +/- 33.7 microg/L to 119.2 +/- 33.6 microg/L. Serum pyridinoline cross-linked telopeptide domain of type I collagen concentrations, a bone resorption marker, were significantly increased from 3.40 +/- 0.77 to 3.87 +/- 1.05 microg/L, and such significant increase was obtained from the 3rd day. The results indicate that some of bone and mineral markers change rapidly in response to triiodothyronine-induced acute thyrotoxicosis, but the manner of change is not the same as that of chronic thyrotoxicosis.

Adult↗
PubMed1999

Estrogen supplementation for bone dematuration in young epileptic man treated with anticonvulsant therapy; a case report.

We encountered a young man treated with anticonvulsant therapy who had greatly reduced bone mineral density. An 18-year-old man was admitted to our hospital for shoulder pain and further evaluation of decreased bone mineral density. He had been treated with anticonvulsants, including phenytoin, phenobarbital, valproic acid and zonisamide for seizures. Although testosterone was found within the normal range for adult men, the serum estrogen concentration was below the detection limit (< 10 pg/ml) and his wrist epiphyses were not yet closed. After 10 months of treatment with the conjugated estrogen, both his height and weight showed improvement, while his bone mineral density and bone age were increased. These findings suggested that estrogen therapy had a significant effect on his skeletal growth and bone maturation in man. This is the first report showing the beneficial effect of estrogen supplementation in an epileptic man receiving treatment with anticonvulsants.

Adult↗
PubMed1999

Body height and weight of patients with childhood onset and adult onset thyrotoxicosis.

The present study has compared body height and weight of thyrotoxic female patients of childhood onset and adult onset. The body height of 141 out of 143 (99%) adult-onset thyrotoxic patients was within the range of mean +/- 2SD for the age-matched general Japanese female population. On the other hand, in 42 patients with childhood-onset thyrotoxicosis, 6 (14%) had their height being greater than the mean + 2SD of general population, and 34 (81%) were taller than the mean value. In 86 patients with siblings, 42 (49%) were at least 2 cm taller than their sisters, and 26 (30%) were more than 2 cm shorter than their sisters. The body weight of 27 out of 42 (68%) patients younger than 20 years was not decreased but was even greater than the mean value for the age-matched general population. The results indicate that excessive thyroid hormone in vivo enhances body height in humans. The increased body weight in some young patients suggests that enhanced dietary intake due to increased appetite in hyperthyroidism has overcome the energy loss with increased metabolism.

Adolescent↗
PubMed1999

Pulmonary microvascular responses to inhaled prostacyclin, nitric oxide, and their combination in anesthetized cats.

Using an X-ray television system on anesthetized cats, we directly measured internal diameter (ID) changes in identical small pulmonary vessels (100-1,100 microm ID) in response to inhalations of 25, 250, and 2,500 ng/kg/min aerosolized prostacyclin (PGI2), 4 and 34 ppm nitric oxide (NO), and the combination of aerosolized PGI2 and NO. We also compared ID changes during 250 ng/kg/min PGI2 inhalation both with and without an Nomega-nitro-L-arginine methyl ester (L-NAME, 30 mg/kg I.V.) pretreatment. In the arteries, inhaled PGI2 increased 100-900 microm vessel ID in a dose-dependent manner but caused no significant, or only slight, ID increases in the vessels larger than this. The greatest ID increase ( approximately 22%) was in the 100-500 microm arteries in response to 2,500 ng/kg/min PGI2 inhalation. PGI2 also increased the ID of the veins (6-12%), but the results were not dose related. NO inhalation also resulted in non-uniform ID response patterns similar to PGI2 with no significant, or only minimal, ID increases of the arteries >900 microm. The simultaneous inhalation of 2,500 ng/kg/min PGI2 and 34 ppm NO increased the arterial ID (maximum approximately 34%) more than either drug alone and to almost the same extent as brought about by injected papaverine (2 mg/kg), a smooth muscle relaxant. Inhaled PGI2 (250 ng/kg/min) decreased pulmonary arterial pressure and increased arterial ID to nearly the same extent with or without L-NAME pretreatment. These results indicate that inhaled PGI2 and inhaled NO locally dilate 100-900 microm pulmonary arteries in a dose-dependent manner and with a similar ID response pattern, and that the combination of these drugs produces a more enhanced vasodilator effect compared to their separate effects and induces the maximum dilated states. The data also suggest that inhaled PGI2 dilates these arteries directly, rather than via secondary release of endogenous NO.

Administration, Inhalation↗
PubMed1999

A novel mutation in the FcgammaRIIIA gene (CD16) results in active natural killer cells lacking CD16.

We report a novel mutation in FcgammaRIIIA (the transmembrane-form CD16) on natural killer (NK) cells in a patient with polyneuropathy. She had no history of recurrent infections. Her NK cells expressed no detectable CD16; however, her NK cytotoxic activity was normal, suggesting that CD16 expression and cytotoxic activity are independent of one another. Molecular analysis revealed a deletion of a single adenine base in exon 4 of CD16 at nucleotide 550. This deletion generates a STOP codon in an extra-cellular domain of the FcgammaRIIIA gene, thereby truncating the CD16 molecule. The patient's NK cells were not recognized by the anti-CD16 monoclonal antibodies 3G8 and Leu11c. Whether the development of her polyneuropathy is associated with this novel mutation is unclear.

Adult↗
PubMed1999

[Acute myelocytic leukemia and plasmacytoma secondary to chemotherapy and radiotherapy in a long-term survivor of small cell lung cancer].

A 68-year-old man was given a diagnosis of lung cancer of the right upper lobe (small cell carcinoma, T 4 N 2 M 0, stage IIIB) in February 1991. The tumor diminished after chemotherapy and radiotherapy. In February 1992, a partial resection of the lower lobe of the right lung was performed because of the appearance of a metastatic tumor. In September 1994, squamous cell carcinoma developed in the lower part of the esophagus, but disappeared after radiotherapy. In February 1998, a diagnosis of myelodysplastic syndrome was made. Two months later, the patient had an attack of acute myelocytic leukemia and died of cardiac tamponade. An autopsy determined that both the lung cancer and esophageal cancer had disappeared. Acute myelocytic leukemia and plasmacytoma of lymph nodes in the irradiated area were confirmed. These were regarded as secondary malignancies induced by chemotherapy and radiotherapy.

Aged↗