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Biomedical subjects

K Tamura

Publications and source records attributed to K Tamura.

At least 1,459 records · Page 81Linked to original sources
PubMedDate not supplied

PG490-88, a new immunosuppressant, effectively prevents acute and chronic rejection in rat renal allografts.

PG490-88 is a semisynthetic derivative of the novel compound PG490 (triptolide) purified from a Chinese herb. It has been shown to prolong acute allograft survival in multiple experimental organ transplant models. However, the effect of PG490-88 on prevention of acute and chronic renal allograft rejection has not been determined. Kidneys of ACI or F344 rats were transplanted into bilaterally nephrectomized LEW recipients as the acute or chronic allograft rejection models, respectively. Treatment of LEW recipients with PG490-88 significantly prolonged ACI kidney graft survival in a dose-dependent manner when compared with the untreated allograft controls. LEW recipients of F344 kidney grafts who received PG490-88 for 90 days with a brief course of low-dose FK506 showed normal serum creatinine levels and markedly reduced histological changes of chronic rejection at day 90 after transplantation. These results suggest that PG490-88 significantly prolongs kidney allograft survival in an acute rejection model and prevents chronic allograft rejection in rats.

Acute Disease↗
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Systemic circulatory parameters. comparison between patients with normal tension glaucoma and normal subjects using ambulatory monitoring.

PURPOSE: To compare circadian changes of systemic circulation in patients with normal tension glaucoma (NTG) and normal subjects. METHODS: Forty-three patients with NTG and 226 normal subjects were enrolled in this study. Circulatory parameters, including blood pressure (BP) and pulse rate (PR), were measured in all subjects for 49 hours using an ambulatory monitoring system. In addition to a comparison between NTG patients and normal controls, the same parameters were compared between NTG patients who had progressive field defects and NTG patients who had stable field defects. RESULTS: The BP in NTG patients was significantly higher than in normal subjects. The nocturnal dip of BP in NTG patients was similar to the dip in normal subjects. However, the BP dip in NTG patients showing progressive visual field defects was significantly smaller than in patients with NTG showing stable visual field defects. Blood pressure fluctuation in sleep in the "progressive" patients was significantly greater than in the "stable" patients. Patients with NTG whose random BP was in a normal range showed a higher BP than normal subjects. The dip in PR in NTG patients was significantly lower than in normal subjects. CONCLUSIONS: An insufficient physiological nocturnal BP dip or a greater nocturnal fluctuation in BP may disturb the microcirculation of, and/or may directly damage, the optic nerve, resulting in increasing field loss in NTG.

Adult↗
PubMedDate not supplied

Mechanism of bone destruction due to middle ear cholesteatoma as revealed by laser-Raman spectrometry.

In an investigation of the mechanism of bone destruction caused by chronic otitis media complicated with cholesteatoma, both the processes of demineralization and remineralization were studied in an animal model and clinically at the molecular level, using a laser-Raman spectrometer. From this investigation, it is proposed that the mechanism of bone destruction associated with cholesteatoma is a form of demineralization.

Adult↗
PubMedDate not supplied

Evolutionary aspects of positioning and identification of vertebrate limbs.

Emerging developmental studies contribute to our understanding of vertebrate evolution because changes in the developmental process and the genes responsible for such changes provide a unique way for evaluating the evolution of morphology. Endoskeletal limbs, the locomotor organs that are unique to vertebrates, are a popular model system in the fields of palaeontology and phylogeny because their structure is highly visible and their bony pattern is easily preserved in the fossil records. Similarly, limb development has long served as an excellent model system for studying vertebrate pattern formation. In this review, the evolution of vertebrate limb development is examined in the light of the latest knowledge, viewpoints and hypotheses.

Animals↗
PubMedDate not supplied

Pattern formation in dissociated limb bud mesenchyme in vitro and in vivo.

A fundamental process in limb bud development is the formation of position-dependent cartilage pattern. Cells of the distal mesenchyme maintain positional values as the expression pattern of transcription factors, for example, hox genes, which induce position-related cell differentiation and cell surface differences. Cultured, dissociated limb bud mesenchymal cells segregate from each other, and eventually form cartilage nodules. This sorting out is position-dependent, not cell-type dependent, suggesting that the positional values may be involved. Positional valves were found to be retained in limb bud recombinants. In the chick system, the expression of HoxA13 and HoxD12 was present in the distal half of stage 20 recombinants, whereas these markers were expressed throughout the stages 25 recombinants. In the Xenopus system, multiple digit formation was introduced in limb recombinants, and a position-related relationship between regeneration potency and the multiple digit formation could be established. This determination of multiple digit formation with different stages of limb mesenchyme may be useful in understanding mechanisms of the loss of vertebrate limb regeneration potency.

Animals↗
PubMedDate not supplied

Respiratory symptoms and pulmonary function among traffic police in Bangkok, Thailand.

The authors undertook a cross-sectional study of the potential adverse health effects of air pollution in Bangkok, Thailand. During 1998 and 1999, the authors administered lung function spirometry tests and a Thai version of the American Thoracic Society's Division of Lung Diseases (ATS-DLD) respiratory questionnaire to 78 male traffic police and 60 male nontraffic police in Bangkok, as well as to 68 male general police in Ayutthaya province, a rural area in Thailand. No consistent trend of decreased pulmonary function was observed in traffic police. The authors controlled for age, height, and smoking index, after which mean levels of forced expiratory volume in 1 sec and maximal expiratory flow rate in 25% of vital capacity (V25) were significantly lower in Bangkok police than in Ayutthaya police. The prevalence of respiratory symptoms among Bangkok police was slightly higher than among Ayutthaya police. Multiple regression analysis identified age and workplace as statistically significant factors that contributed to the values of forced expiratory volume in 1 sec and V25. This study provided some evidence of an increase in prevalence of obstructive changes in the peripheral airways among traffic police in Bangkok.

Adult↗
PubMedDate not supplied

Assessment of upper limb function in hemiplegia by measuring transcutaneous oxygen tension.

To investigate whether the noninvasive determination of transcutaneous oxygen tension (TcO2) can be used to evaluate the degree of hemiplegia, we measured TcO2 before and after a 2-mo rehabilitation course in 12 patients with hemiplegia caused by cerebrovascular diseases. All patients with no evidence of heart failure (ejection fraction evaluated by echocardiogram: 68.7 +/- 6.4%) began to receive conventional physical therapy a few days after the onset of stroke. The measurement of TcO2 was performed at 9:00 a.m. with an electrode placed on the skin surface of the flexion side of the forearm 5 cm distal to the elbow. Before rehabilitation, the difference in TcO2 between the paralyzed and healthy upper limbs ((delta)TcO2) in patients at Brunnstrom's stage V was significantly lower than that in patients at stages II, III, and IV (P < 0.05, P <0.01, and P < 0.01, respectively). After rehabilitation, (delta)TcO2 in patients at Brunnstrom's stage V was significantly lower than that in patients at stage III(P < 0.05). The (delta)TcO2 in the patients with severe hemiplegia was larger than that in patients with slight hemiplegia. In addition, TcO2 at the paralyzed upper limb increased significantly after rehabilitation (before 62.7 +/- 10.5 mm Hg; after 71.9 +/- 9.0 mm Hg; P < 0.05), although arterial blood oxygen tension (PaO2) did not. Therefore, the TcO2 determination may be useful in assessing the degree of hemiplegia in upper limbs.

Aged↗
PubMedDate not supplied

Effective physical therapy for chronic obstructive pulmonary disease. Pilot study of exercise in hot spring water.

Respiratory function and arterial blood gas were examined before and after a two-month exercise program performed in a pool filled with hot spring water in 22 patients (70.9 +/- 9.1 years of age) with stable chronic obstructive pulmonary disease (12 cases of bronchial asthma and 10 cases of pulmonary emphysema) treated at our hospital between 1991 and 1994. The ratio of forced expired volume in one second to forced vital capacity (FEV1%) was significantly increased after the exercise program (P < 0.05), whereas the ratio of forced vital capacity to predicted normal value (%FVC) did not change. In addition, a tendency toward an increase in peak flow without an increase in maximum expiratory flow at 25 and 50% (V25 and V50) was observed. Although PaO2 was not increased, PaCO2 was selectively decreased by the exercise program (P < 0.05). The changes in respiratory function and arterial blood gas were considered attributable to respiratory muscle training and small airway clearance. Exercise in a pool filled with hot spring water may be useful in treating chronic obstructive pulmonary disease.

Aged↗
PubMedDate not supplied

Breathing out into water during subtotal immersion: a therapy for chronic pulmonary emphysema.

OBJECTIVE: To determine the importance of a breathing out into water exercise during subtotal immersion for emphysematous patients. DESIGN: Results of a respiratory function test and arterial blood gas analysis were examined to compare the programs of breathing exercise with and without the breathing out into water exercise. The breathing exercises in a pool filled with 38 degrees C water were performed 30 min/day, 5 days/wk, for 2 mo in 17 patients with stable chronic emphysema. Patients were randomly assigned to breathing exercise programs including subtotal water immersion with the nose and mouth either immersed (9 patients) or out of the water (8 patients) during exhalation. RESULTS: The ratio of %forced expired volume in 1 sec to forced vital capacity and %forced vital capacity at rest were significantly increased in the program with the breathing out into water exercise, but they did not change in the program without the breathing out into water exercise. A significant increase in peak flow was observed in the former program, although it did not change in the latter program. The maximal expiratory flow at 25% did not change in either program. Pao2 was significantly increased and Paco2 was significantly decreased in the former program, although a trend for a decrease in Paco2 was observed in the latter program. CONCLUSIONS: These results suggest that the breathing out into water exercise enhances the effects of a breathing exercise during immersion and is useful in rehabilitation for chronic pulmonary emphysema.

Aged↗
PubMedDate not supplied

Laser vascular welding in biologic grafts.

This study evaluated the possibility and efficacy of laser welding in biologic vascular grafts. Grafts were anastomosed to 21 canine peripheral (femoral and/or carotid) arteries or coronary arteries with a Nd-YAG laser using the contact method. The laser welds were fashioned using 1-1.5 W power for 1-3 sec. The grafts used were heparinized canine carotid artery cross-linked with polyepoxy compounds. The welding was a success in 92% (22/24) of the peripheral artery and 83% (5/6) of the coronary artery procedures. The early patency rate was 100%. The anastomotic sites were strong enough to withstand high pressure (more than 300 mmHg of arterial pressure). Histologic examination was performed on days 0 and 3, 1 week, 3 weeks, or more than 1 month postoperatively to compare the progression of healing. The laser welded sites had a smooth external surface and minimal damage of the internal layer, with minimal inflammatory response and no pathologic granulation. The welded sites fused strongly after 1 postoperative week. In conclusion, an Nd-YAG laser, using a contact method, could successfully weld peripheral and coronary arteries to biologic vascular grafts.

Anastomosis, Surgical↗
PubMedDate not supplied

Angiotensin II receptors in cardiac left ventricles of Dahl rats.

1. Dahl Iwai salt-sensitive (DS) rats have been reported as becoming hypertensive with left ventricular hypertrophy (LVH) and heart failure when on a high-salt diet. Their circulating renin-angiotensin system (RAS) has been reported to be suppressed. To evaluate the role of angiotensin II (AngII) type 1 and type 2 receptors (AT1 and AT2, respectively) in LVH, we compared cardiac AT1 and AT2 receptors in 10-week-old DS rats and Dahl Iwai salt-resistant (DR) rats. 2. Seven pairs of 6-week-old male DS and DR rats were fed either a low- or high-salt diet (0.3 or 8% NaCl, respectively) for 4 weeks. Left ventricular AngII receptors were measured by radioligand binding assays using [125I]-[Sar1,Ile8]-AngII in plasma membrane fractions from these four groups. The AT1 and AT2 receptors were distinguished using their specific antagonists CV 11974 and PD 123319, respectively. 3. The high-salt diet increased blood pressure and the left ventricle:bodyweight ratio in DS rats. However, neither Bmax for AT1 and AT2 receptors nor Kd for [125I]-[Sar1,Ile8]-AngII differed between the groups. These results are different from those of other reports of pressure-overload LVH, such as spontaneously hypertensive rats or renovascular hypertension rats, in which AT1 and AT2 receptors were reported to be up-regulated.

Animals↗
PubMedDate not supplied

Prognostic impact of plasma brain natriuretic peptide for cardiac events in elderly patients with congestive heart failure.

BACKGROUND: Plasma brain natriuretic peptide (BNP) has been reported to be useful in determining the prognosis of patients with ischemic heart disease and cardiomyopathy. However, aging increases the level of plasma BNP; therefore, the prognostic impact of plasma BNP in elderly patients with congestive heart failure has not been fully established. OBJECTIVE: We sought to determine whether plasma BNP could predict recurrent cardiac events in elderly patients with congestive heart failure. METHODS: Forty-eight consecutive elderly patients (>65 years old) were enrolled in the present study. All patients were admitted with their first episode of congestive heart failure. Clinical characteristics, plasma BNP, left ventricular ejection fraction, and left ventricular mass index were compared between patients with and those without recurrent cardiac events. RESULTS: During the follow-up period, twelve cardiac events were observed. The New York Heart Association functional class was signi- ficantly higher in patients with cardiac events than in those without (p < 0.05). The plasma BNP level in pa- tients with cardiac events was significantly higher than in those without (521.0 +/- 156.0 vs. 126.8 +/- 20.1 pg/ml, p<0.001), despite more frequent treatment with angiotensin-converting enzyme inhibitors (75 vs. 28%, p<0.05). The left ventricular ejection fraction was significantly lower and the left ventricular mass index higher in patients with cardiac events as compared with those without (38.1 +/- 5.0 vs. 49.2 +/- 2.4%, p < 0.05; 193.8 +/- 14.3 vs. 132.6 +/- 7.8 g/m(2), p < 0.001, respectively). The plasma BNP was selected as an independent factor associated with cardiac events besides New York Heart Association functional class, left ventricular ejection fraction, and left ventricular mass index using multivariate Cox proportional-hazards regression analysis (hazard ratio = 2.656, p<0.05). The cardiac event rate was significantly higher in patients with a plasma BNP concentration >132 pg/ml using Kaplan-Meier analysis (p < 0.001). Moreover, the plasma BNP level correlated inversely with the length of time from hospital discharge to a cardiac event (r = -0.575, p<0.05). CONCLUSION: Measuring the plasma BNP level before hospital discharge in elderly patients with congestive heart failure was more useful than other conventional examinations for predicting the recurrence of cardiac events.

Aged↗
PubMedDate not supplied

Comparison of urine cytology between the ileal conduit and Indiana pouch.

OBJECTIVE: To compare the cytomorphologic features of urine obtained from two different kinds of urinary diversions constructed after total bladder resection. STUDY DESIGN: The smears of urine from 11 ileal conduits and 6 Indiana pouches were evaluated. All patients underwent total bladder resection due to transitional cell carcinoma (TCC) or other kinds of cancer before urine diversion. RESULTS: The cytologic features of Indiana pouch urine include degenerated, small, round cells without columnar cells derived from intestinal epithelium. In ileal conduit urine, well-preserved columnar cells and degenerated, small, round cells were frequently observed. The columnar cells in ileal conduit urine exhibited cytologic features that should be distinguished from TCC cells. CONCLUSION: The method of reconstructing the urinary tract is important in urine cytology from urine diversions because the cytomorphologic features of urine are different between the two kinds of urinary diversions. Since columnar cells in ileal conduit urine might lead to misdiagnosis as TCC, special consideration is required to examine ileal conduit urine.

History, 16th Century↗
PubMedDate not supplied

Comparative changes in the liver of female Fischer-344 rats after short-term feeding of a semipurified or a semisynthetic L-amino acid-defined choline-deficient diet.

Groups of female Fischer-344 rats were fed a semipurified choline-deficient (CD) diet, or a semisynthetic L-amino acid-defined choline-deficient (CDAA) diet, for up to 12 wk and effects of the 2 diets on the liver were compared. Steatosis was diffuse and more severe throughout in rats fed the CDAA diet than in rats fed the CD diet. Greater elevations in serum aspartate and alanine aminotransferase activities were also present in the former rats, along with higher 2-bromodeoxyuridine labeling indices in the liver. Discrete amounts of 8-hydroxyguanine were detected in liver DNA, but were not significantly different in rats fed the 2 diets, or from those present in a group of control rats killed at 0 time. Glutathione S- transferase placental form-positive focal lesions were not observed in any of the rats. The results show that the CDAA diet causes more severe degrees of steatosis and liver cell death and proliferation than the CD diet, raising the possibility that it may, in contrast to the CD diet, result in the eventual induction of hepatocellular carcinomas in female Fischer-344 rats.

Alanine Transaminase↗
PubMedDate not supplied

Motor aphasia due to prolonged hypoglycaemic coma in a patient with insulin-dependent diabetes mellitus.

A 45-year-old insulin-dependent diabetic man was in a hypoglycaemic coma for one month but recovered after continuous infusion of glucose and insulin. An isolated neurological deficit, motor aphasia, persisted after recovery from the coma. Repeated computerized tomography did not demonstrate any abnormal findings attributable to coma or aphasia. Precise follow-up examinations of aphasia showed improvement of Broca type motor aphasia to transcortical motor aphasia. Hypoglycaemic aphasia in a patient after recovery from prolonged coma is rare and its clinical course and pathogenesis are discussed with reference to the available literature.

Aphasia, Broca↗