Biomedical subjects
Publications and source records attributed to K Murata.
Gellan lyase was purified from the culture fluid of soil samples incubated in a medium containing gellan as a sole carbon source. The enzyme was a monomer with a molecular mass of 140 kDa and was most active at pH 7.5 and 45 degrees C. The enzyme was highly specific to gellan and lowered the viscosity of the polymer.
PURPOSE: To determine the diagnostic efficacy of hard- and soft-copy computed radiographic (CR) images versus conventional screen-film images of the chest in the detection of subtle pulmonary abnormalities. MATERIALS AND METHODS: Twenty observes compared 87 hard-copy and soft-copy CR images with hard-copy screen-film images. Of 87 test images, 45 (including two identical sets of 12 images to test intra-observer variability) were abnormal and 42 (including two identical sets of 12 images) were normal. Of the 45 abnormal images, 15 (including two sets of four identical images) showed subtle abnormalities, 15 (including two sets of four identical images) showed mild abnormalities, and 15 (including two sets of four identical images) showed obvious abnormalities. Soft-copy viewing provided three differently processed images of every radiograph. RESULTS: No statistically significant differences in receiver operating characteristic analyses were found among hard-copy screen-film images, hard-copy CR images, and soft-copy CR images, even in the group with subtle interstitial abnormalities. CONCLUSION: Hard-copy and soft-copy chest CR images are acceptable and available in place of screen-film images for primary interpretation of subtle interstitial lung diseases.
Stimulation of the dorsal part of the midbrain periaqueductal gray matter (dPAG) inhibits baroreflex vagal bradycardia (BVB) via a central mechanism. Here we report that the dPAG suppresses vagal bradycardia also by a peripheral mechanism. In chloralose-urethan-anesthetized, beta-blocked rats, the cervical vagus nerve was cut and the distal cut end was electrically stimulated to induce vagal bradycardia (VIB). Sustained electrical stimulation of the dPAG attenuated VIB in a duration-dependent manner but did not affect bradycardia induced by intravenous acetyl-choline (AIB). The dPAG inhibition of VIB was abolished by C1 transection. Intravenous norepinephrine (NE) reduced VIB but did not affect AIB. Both the dPAG and NE inhibitions of VIB were largely attenuated during intravenous prazosin, a selective alpha 1-receptor antagonist. In contrast, BVB provoked by aortic depressor nerve stimulation was remarkably inhibited by a shortly preceding dPAG stimulation, but this inhibition was not affected by C1 transection. Prazosin treatment did reduced the inhibition, but only moderately. In conclusion, the dPAG has a potential ability to suppress VIB by prejunctionally inhibiting acetylcholine release from cardiac vagus nerve terminals via alpha 1-receptors. However, dPAG stimulation first suppresses BVB largely at a central site, leaving a limited fraction of vagal outflow to be inhibited by a prejunctional mechanism operating with long latency.
This study was undertaken to investigate the relationship of the serum sex hormone-binding globulin (SHBG) levels with the plasma insulin concentration and with the insulin resistance in male subjects with noninsulin-dependent diabetes mellitus (NIDDM). This investigation comprised 12 patients with NIDDM and 16 normal subjects matched for age, sex, and body mass index (BMI). There was a significant increase in insulin levels (P < 0.03) and a decrease in SHBG levels (P < 0.01) in the diabetic group as compared with those of the normal group. The sex hormone and plasma insulin levels were measured in NIDDM patients undergoing exercise and dietary therapy. Insulin sensitivity was evaluated by the hyperinsulinemic euglycemic clamp technique expressed as the glucose infusion rate (GIR) before and after the treatment. The SHBG levels correlated significantly with the insulin concentrations (r = -0.643, P < 0.05) and with the GIR (r = 0.615, P < 0.05) before the treatment. The SHBG levels (P < 0.02) and GIR (P < 0.01) increased, and the insulin concentrations (P < 0.01) decreased significantly during the treatment. The SHBG levels showed a negative and significant correlation with the plasma insulin concentrations at the end of the clamp study before (r = -0.615, P < 0.05) and after (r = -0.626, P < 0.05) the treatment. These findings suggest that, in the hyperinsulinemic state, plasma insulin has a direct effect on the SHBG levels. SHBG levels decreased significantly during the clamp study before (P < 0.02) and after (P < 0.01) the treatment. This may represent the acute effect of insulin on the SHBG levels. Briefly, these results suggest that insulin may directly affect the SHBG levels and that SHBG may constitute an index of the insulin resistance only in the hyperinsulinemic state.
Nowadays practical antihypertensive therapy involves not only simple normalization of blood pressure but also a reduction of the risks of cardiovascular disease. In this multicenter open-label study, the long-term effects of doxazosin, an alpha 1-adrenergic receptor blocker, on serum lipids were prospectively investigated in 253 patients with essential hypertension. They were treated with doxazosin for 1 year. The averaged the blood pressure was maintained at levels lower than 150/90 mmHg throughout 1 year, but heart rate did not increase. After 3 months of doxazosin therapy, total and low density lipoprotein-cholesterol levels in serum were significantly reduced by 3.3% and 3.4%, respectively, and these levels were maintained throughout the study period. This effect of doxazosin on serum lipids was especially prominent in patients with hypercholesterolemia. In addition, the lipid profile of these patients was favorably altered even when other antihypertensive drugs or lipid-lowering drugs had already been used or were used concurrently. These results constitute useful information for physicians who treat hypertension with alpha 1-blockers to reduce the overall risk of cardiovascular disease.
This study was designed to investigate the possibility of sex and age differences in the insulin-blood pressure relationship in a general Japanese population with a wide age range. Fasting serum insulin, lipids, plasma glucose, blood pressure and anthropometric measurements were made on 1,537 men and 843 women aged 16 to 65 years. Of the 2,380 subjects in the present analysis, 290 (184 men, 106 women) were hypertensive. When divided into four age groups (16 to 17, 21 to 22, 30 to 49 and 50 to 65 years), the male hypertensive subjects were found to have significantly higher fasting insulin levels, triglycerides levels and body mass index and lower glucose/insulin ratios than normotensive male subjects in all age groups. In the women, there was no significant difference in serum insulin levels or glucose insulin ratios between the hypertensive and normotensive groups in any age group. Simple correlation analysis showed that blood pressure was statistically significantly correlated with serum insulin levels and body mass index in the men in all age groups. In women, the correlation between blood pressure and serum insulin was insignificant in the 21- to 22-year-old age group. In men but not women, multivariate analysis showed that blood pressure was significantly and independently correlated with fasting serum insulin levels. The results of this study suggests the existence of sex and age differences in the insulin-blood pressure relationship in a Japanese population.
Polymerase chain reaction (PCR) amplification of a partial fragment of the sex determining region Y (SRY) gene was used for sexing a young Linne's two-toed sloth (Choloepus didactylus), a species in which gender determination from the external genitalia is difficult. DNA was extracted from hairs of a 5-month-old sloth as well as the dam and sire as external controls. A SRY fragment (216 bases) was PCR-amplified both from the offspring and the sire, but not amplified from the dam. The DNA sequence (166 bases without primers) of the sloth PCR product was determined and compared with SRY sequences of other mammals previously reported. High homology of their nucleotide (74.1-86.8%) and deduced amino acid (63.6-85.5%) sequences indicates that the PCR product of the sloth was amplified from a region of the SRY gene, and that SRY sequences are conserved throughout mammalian orders. From the result the sex of the young sloth was determined as a male. The PCR method using hairs for sexing the sloth provides an advantageous tool for captive propagation plan in zoos. To the authors' knowledge, no report regarding SRY sequences in the order Xenarthra (Edentata) has been published.
To examine which of the faster or slower large myelinated nerve fibers (alpha fiber group) are affected earlier by diabetes mellitus (DM), the distribution of nerve conduction velocities (DCV) and conventional sensory nerve conduction velocities (SCV) in the median nerve were measured in 10 male DM patients aged 35-58 (mean 50) years. The patients had suffered from DM for 0-30 (mean 11) years; their fasting blood sugar (FBS) levels were 105-363 (mean 219) mg/100 ml. The DCV was expressed by the conduction velocities below which 10, 20, ......, 80 and 90% of active fibers lie (V10, V20, ......, V80 and V90 velocities, respectively). In DM patients, the V30 to V90 velocities of the DCV as well as the SCV were significantly smaller than those of age-matched male controls. The results of multiple regression analysis indicated that FBS was inversely related to V50 to V90 velocities; duration of the disease was also significantly related to V80 and V90 velocities. These data suggest that faster nerve fibers are more susceptible to DM than slower fibers are; changes in conduction velocities of the faster fibers are closely associated with FBS and duration of DM.
The peribronchovascular interstitium, including bronchial vessels and lymphatic channels, is an important anatomic component of the lung, especially the pulmonary hilum [1-3] (Fig.1). Various pathologic processes involve and spread along this interstitium [4, 5]. Although it has been difficult to accurately evaluate the morphologic changes occurring in the peribronchovascular interstitium with conventional CT or MR imaging [6], spiral CT and electron-beam CT can show these changes clearly and consistently [7, 8]. A judgement as to whether the peribronchovascular interstitium is normal or abnormal is necessary for the CT diagnosis of pulmonary hilar lesions. In this assay, the normal peribronchovascular interstitium and various pathologic processes involving this interstitium are shown as they appear on thin-section electron-beam CT scans.
OBJECTIVE: To determine the secretion of insulin, C-peptide, and proinsulin after oral glucose loading in healthy elderly subjects compared with middle-aged subjects with and without obesity and with NIDDM. RESEARCH DESIGN AND METHODS: Subjects fell into four groups: nonobese middle-aged normal control subjects (CNT group; n = 38, 40-64 years old); obese normal subjects (OB group; n = 18, 40-64 years old); nonobese NIDDM subjects (NIDDM group; n = 28, 40-64 years old); and nonobese elderly subjects (OL group; n = 17, 65-92 years old). Insulin, C-peptide, and proinsulin were determined by radioimmunoassay in plasma samples taken at 0, 30, 60, and 120 min during a 75-g oral glucose tolerance test (OGTT). RESULTS: There were no differences in plasma glucose during the OGTT among the three nondiabetic groups. Hyperinsulinemia was significant in the OB and NIDDM groups but not in the OL group. On the other hand, absolute hyperproinsulinemia was significant in the OL and NIDDM groups compared with the CNT group. Increased proinsulin was rather dominant in the OL group, especially late after glucose loading. Molar ratios of proinsulin to insulin or C-peptide thus were significantly higher in the OL and NIDDM groups. CONCLUSIONS: Alteration of pancreatic beta-cell function independent of that seen with NIDDM occurred in relation to aging. This may be a predisposing factor to the development of impaired glucose tolerance or NIDDM in elderly subjects, that is, independent of obesity.
To confirm daily accumulation of visual fatigue induced by work with visual display terminals (VDT), visual evoked potential (VEP), near point distance (NPD) and critical flicker fusion (CFF) were measured in three VDT workers and three sex- and age-matched controls (non-VDT workers) in the morning, noontime and evening for five consecutive days (Monday to Friday), totally 15 times per subject. The workers had been engaged in wireless handling operation, with VDTs, of an unmanned power shovel (Worker 1), an unmanned 78-ton dump truck (Worker 2) and mobile monitor-cameras (Worker 3), for 10 months. Their working hours were about 6.5 hours per day; but, the Worker 2 could take a 10-minute recess (a period without VDT work) per about 30 minutes during working hours. Significant daily variations in the VEP latency, NPD and CFF were found in the Worker 1 or Worker 3 despite the absence of any significant daily or diurnal variations in the non-VDT workers; the trends in the variations were getting worse from Monday to Friday. The NPD in the VDT workers was significantly longer than that in each of the matched controls; also, the CFF in the Workers 1 and 3 was significantly depressed. The changes in the VEP latency from morning to noontime and in the NPD and CFF from noontime to evening were significantly larger in the VDT worker than in the matched control. These findings suggest that VDT work probably affects visual function assessed by the VEP, NPD and CFF. Visual fatigue due to long-term VDT work may tend to be accumulated day by day.
The plasma concentration of macrophage colony-stimulating factor (M-CSF) was measured in 10 patients with acute type adult T cell leukemia (ATL) during the clinical course before and after chemotherapy. M-CSF concentration decreased significantly when the patients achieved complete remission (CR) or partial remission (PR) (t-test: p = 0.0001). Five of the patients showed disease progression after several months of PR, and plasma M-CSF increased at that time (t-test: p = 0.0456). Thus, plasma M-CSF concentration appeared to accurately reflect the disease activity in ATL. In support of these results, all three ATL cell lines established from these patients secreted M-CSF in vitro after stimulation with phorbol myristate acetate (PMA) or concanavalin A (Con A). Plasma M-CSF concentration, however, increased transiently when the patients were febrile (t-test: p = 0.0001), even though their ATL condition was unchanged. Taken together, these results indicate that there are two sources of increased plasma M-CSF concentration in ATL; ATL cells themselves and normal parenchymal cells that cause this increase as the result of elevated body temperature due to inflammation.
Adult T cell leukemia (ATL) cells show a mature helper-inducer T cell phenotype and are thought to secrete many kinds of cytokines in vivo, complicating the clinical features in these patients. In an attempt to specify the cytokines produced by ATL cells, we measured the cytokine concentration in the culture supernatants of three ATL cell lines, all of which were confirmed to be true peripheral blood ATL cell in origin. All these cell lines showed the same cytokine production profile, secreting IL1-alpha, IL1-beta, LD78(MIP-l alpha), TNF-alpha, IFN-gamma, and GM-CSF, but not secreting IL-1 alpha, IL-1 beta, IL-1 receptor antagonist (IL-1 Ra), IL-4, IFN-alpha, and G-CSF irrespective of the stimulatory agents used. Such limited cytokine production may indicate the specific origin of ATL cells within the helper-inducer T cell subtypes. Moreover, these results explain some of the unusual clinical features of ATL patients.
We have developed a system that measures the volume of air cells in the temporal bone through computerized digital processing of high-resolution CT images. By using this method, the volume of pneumatization was measured, and the results were compared with the measured area of pneumatization obtained from two conventionally used simple ear X-ray methods (the planimeter and rectangular dimensional methods). A total of 57 ears, from 34 subjects, confirmed as normal by CT were examined. The average volume of pneumatization measured on CT images was 5.97 +/- 4.15ml, and the average areas of pneumatization measured by the planimeter and rectangular methods were 9.08 +/- 5.64 and 17.39 +/- 9.77 cm2, respectively. Graphically, when the volume of pneumatization was plotted on the Y axis and the planimeter-measured area of pneumatization on the X axis, a regression formula of Y = 0.651X + 0.054 was obtained, with a correlation coefficient of 0.89. With the volume of pneumatization plotted on the Y axis and the rectangular-dimensional-measured area of pneumatization on the X axis, the regression formula was Y = 0.375X - 0.559, with a correlation coefficient of 0.88. Both these correlation coefficients were considered high. Furthermore, 3D models of the air cells in the temporal bone were created and compared for patients with high and low correlations. In order to capture the morphological characteristics of these 3D models, they were examined from four different angles (lateral, upper lateral, anterior lateral and upper medial). The results showed that regardless of whether air-cell growth was present in the direction of the apex partise petrosae in patients with a low correlation coefficient, such growth played a major role in the degree of the correlatiton. Future studies will be required to clarify this point, though it can already be said that 3D models are indispensable for studying the air cells in the temporal bone. When we compared the volume and area of pneumatization in the temporal bone at different CT cross-sections, we found correlation coefficients in the vicinity of the canalis semicircularis lateralis of about 0.9 or higher. A statistical comparison of correlation coefficients for the CT, planimeter, and rectangular dimensional methods, made by using the CT cross-section with the highest coefficient, found a significant difference between the CT method and the other two methods (p < 0.05). In other words, the volume of pneumatization can be estimated more accurately with CT images than with simple ear X-rays.
BACKGROUND: The rise in blood pressure associated with a clinic visit (the white-coat phenomenon) may result from anxiety or an alerting reaction. There is evidence to suggest that glucocorticoids may be involved in the mechanism of stress-related blood pressure elevation, but the relationship between the white-coat phenomenon and glucocorticoids has not been assessed. DESIGN: Forty-eight young subjects with essential hypertension were compared with 12 control normotensive subjects. METHODS: Home blood pressure monitoring for 7 days and serum cortisol at 0900 h and 2 h rest at 1100 h were measured. The white-coat phenomenon was calculated for systolic and diastolic blood pressure and average home blood pressure. RESULTS: The serum cortisol level was significantly greater at 0900 h than that at 1100 h in the hypertensive subjects and was higher in the hypertensive subjects than in the normotensive subjects (21.5 +/- 0.5 versus 14.3 +/- 0.9 µg/dl), but there was no difference between serum cortisol levels at 1100 h in the two groups. The magnitude of the white-coat phenomenon, which was greater in the hypertensive subjects than in the normotensive group (22 +/- 2/12 +/- 1 versus 4 +/- 3/1 +/- 3 mmHg), correlated with serum cortisol at 0900 h, but not at 1100 h. The higher level of serum cortisol at 0900 h was confirmed by another measurement conducted 4 months later in a subsample of the hypertensive subjects ( n = 18). CONCLUSIONS: These results suggest that the white-coat phenomenon is related to the transient increase in serum cortisol or psychological stress, or both, which can trigger arousal of the hypothalamic pituitary adrenocortical axis.
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Serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured by ELISA in patients with 18 inflammatory myopathies as well as 23 healthy controls. Both serum sICAM-1 and sVCAM-1 levels were elevated in patients with active polymyositis. Serum sVCAM-1 levels were elevated in the active stage of dermatomyositis, while sICAM-1 levels were elevated only in patients with dermatomyositis complicated with interstitial pneumonia. In paired serum samples before and after prednisolone therapy, elevated serum sICAM-1 and sVCAM-1 levels decreased in patients responding well to steroid therapy without complications. These findings suggested that soluble adhesion molecules reflect as the clinical activity of inflammatory myopathies.