Biomedical subjects

Masayuki Kambe

Publications and source records attributed to Masayuki Kambe.

10 recordsLinked to original sources

PubMed2003

Cardiac angiotensin II type 2 receptor activates the kinin/NO system and inhibits fibrosis.

We have previously demonstrated that stimulation of the angiotensin (Ang) II type 2 receptor in vascular smooth muscle cells caused bradykinin production by activating kininogenase in transgenic mice. The aim of this study was to determine whether overexpression of AT2 receptors in cardiomyocytes attenuates Ang II-induced cardiomyocyte hypertrophy or interstitial fibrosis through a kinin/nitric oxide (NO)-dependent mechanism in mice. Ang II (1.4 mg/kg per day) or vehicle was subcutaneously infused into transgenic mice and wild-type mice for 14 days. The amount of cardiac AT2 receptor relative to AT1 receptor in transgenic mice was 22% to 37%. Ang II caused similar elevations in systolic blood pressure (by approximately 45 mm Hg) in transgenic mice and wild-type mice. Myocyte hypertrophy assessed by an increase in myocyte cross-sectional area, left ventricular mass, and atrial natriuretic peptide mRNA levels were similar in transgenic and wild-type mice. Ang II induced prominent perivascular fibrosis of the intramuscular coronary arteries, the extent of which was significantly less in transgenic mice than in wild-type mice. Inhibition of perivascular fibrosis in transgenic mice was abolished by cotreatment with HOE140, a bradykinin B2 receptor antagonist, or L-NAME, an inhibitor of NO synthase. Cardiac kininogenase activity was markedly increased (approximately 2.6-fold, P<0.001) after Ang II infusion in transgenic mice but not in wild-type mice. Immunohistochemistry indicated that both bradykinin B2 receptors and endothelial NO synthase were expressed in the vascular endothelium, whereas only B2 receptors were present in fibroblasts. These results suggest that stimulation of AT2 receptors present in cardiomyocytes attenuates perivascular fibrosis by a kinin/NO-dependent mechanism. However, the effect on the development of cardiomyocyte hypertrophy was not detected in this experimental setting.

Angiotensin II↗

PubMed2003

[Why does EBD need to diagnose and to therapy for patients, now?].

G. Guyatt reported the first paper on Evidence Based Medicine(EBM) at 1991. Everybody could understand rapidly the necessary of EBM to diagnose and medical treat the patients from then. So, I will tell you the recent actions of EBLM committee of Japan Society of Clinical Laboratory Medicine (JSLM/C-EBLM) related with EBM. I define EBLM(Evidence-Based Laboratory Medicine) has the total functions to use the clinical laboratory data by evidence for the diagnosis and the therapy of patients. JSLM/C-EBLM was seted up at 1999 and supported EBD(Evidence-Based Diagnosis) Forums as the main action. JSLM/C-EBLM will make and use practically the new meta-analysis tools and educate about EBLM from now.

Clinical Laboratory Techniques↗

PubMed2003

[A case of tomato juice-induced oral allergy syndrome in which dyspnea onset occurred during the season of Japanese cedar pollen dispersion].

A 42-year-old-man with a history of Japanese cedar pollinosis repeatedly visited the emergency clinic due to dyspnea during the season of Japanese cedar pollen dispersion. Before each onset of this symptom, he had always drunk tomato juice. Swelling of the oral and nasal mucosa, and congestion of the bulbar conjuctiva was observed. No audible wheezing was present. His pulmonary function test results were normal (FEV 1.0 = 4.02 L, %FEV 1.0-124%, negative reversible test). The CAP RAST scores were 4 for tomatoes and 3 for Japanese cedar pollen. A result was obtained in a challenge test using tomato juice. Since tomato juice was involved in the development of the symptoms, a diagnosis of oral allergy syndrome induced by tomato juice was made. When tomato juice consumption was avoided, no symptoms developed. A common antigenicity was found between tomatoes and Japanese cedar pollen. This may be associated with the development of this allergy during the dispersion season of Japanese cedar pollen. The dyspnea may have reflected a feeling of pharyngeal narrowing which is a symptom of oral allergy syndrome. The possibility of oral allergy syndrome as the chief complaint should be considered also in patients with dyspnea. This is the first reported case of oral allergy syndrome induced by tomato juice.

Adult↗

PubMed2003

[Pulmonary function tests].

The spirometry has been most valuable pulmonary function test and it defines pulmonary physiology. But the spirometry has not been widely used by general physicians in Japan. The spirometry is effort-dependent test, so, they seem to keep it at a distance. It's desirable that pulmonary function tests are effort-independent. We introduce some effort-independent pulmonary function tests and refer to analysis of exhaled breath condensate.

Humans↗

PubMed2003

[Effort-independent pulmonary function tests].

Many pulmonary function tests require forced expiration, and the precision of the tests depends on the effort of the subjects. In elderly people, the reproducibility of test results may be inadequate because of insufficiency of the subjects' effort, and the diagnosis of COPD, which is frequently observed in elderly people, is often difficult. To improve the accuracy of the diagnosis, pulmonary function tests that do not require effort are needed. In this study, effortless pulmonary function tests (examinations of the cardiogenic oscillation, negative expiratory pressure, exhaled temperature, and exhaled breath condensate), the application of which to various respiratory disorders (i.e., sleep apnea syndrome, COPD, bronchial asthma) is attempted, are presented.

Asthma↗

PubMed2002

Cardioprotective role of AT2 receptor in postinfarction left ventricular remodeling.

The aim of this study was to determine the role of the AT2 receptor (AT2R) in left ventricular (LV) remodeling after myocardial infarction (MI). The left anterior descending arteries were ligated in AT2R gene knockout (Agtr2-) and wild-type (Agtr2+) mice. The LV remodeling was evaluated by echocardiography and histology over a period of 2 weeks after MI. The infarct sizes in hearts excised from Agtr2+ and Agtr2- mice on day 1 were similar. The mortality rate of Agtr2- mice (62.9%) on day 14 after MI was significantly (P<0.05) higher than that of Agtr2+ mice (39.7%). Accordingly, LV/body weight ratios (3.7+/-0.2 versus 3.0+/-0.1 on day 14) and LV end-diastolic (4.8+/-0.3 versus 3.9+/-0.4 mm on day 7) and end-systolic (4.4+/-0.3 versus 3.2+/-0.6 mm on day 7) dimensions evaluated by echocardiography were significantly greater in Agtr2- than in Agtr2+ mice. The rates of ventricular arrhythmia, rates of cardiac rupture, and blood pressures in the 2 strains were similar after MI. Myocyte cross-sectional areas were increased after MI, but the magnitudes were similar in Agtr2+ and Agtr2- mice, indicating the greater increases in LV dimensions and weight in Agtr2- mice are due to elongation of myocyte length and/or an increase in the interstitial weight (including vasculatures, infiltrated cells, and interstitial fluid). Interstitial fibrosis in remote myocardium was not evident in either strain. These results indicate AT2R plays a significant role in the protection against early development of LV dilation, thereby reducing the early mortality rate after MI.

Animals↗

PubMed2002

Estrogen replacement suppresses function of thrombin stimulated platelets by inhibiting Ca(2+) influx and raising cyclic adenosine monophosphate.

OBJECTIVE: Estrogen replacement therapy (ERT) in postmenopausal women reduces the risk of cardiovascular diseases. Beneficial changes in lipid profiles account for only one part, thereby raising the question of other estrogen induced benefit that may be lost at menopause. The purpose of this study was to determine the effects of estrogen replacement therapy (ERT) on platelet function of postmenopausal women. METHODS: The effect of 4 weeks ERT (conjugated estrogens 0.625 mg/day) on platelet function was evaluated ex vivo in 18 postmenopausal women (mean age 53 +/- 5 years, after menopause 3.8 +/- 1.9 years). RESULTS: After ERT, (1) plasma concentrations of estrone and estradiol significantly increased (estrone: 16 +/- 7-211+/- 80 pg/ml, estradiol: 14+/- 3-125 +/- 49 pg/ml, P<0.05) and LDL-cholesterol decreased (129 +/- 23-94 +/- 25 mg/dl, P<0.05). Plasma 6-keto-PG F(1) alpha significantly increased (7.2 +/- 3.4-13.3 +/- 6.7 pg/dl, P<0.05). (2) platelet aggregation and positive staining for P-selectin in thrombin- (0.1 and 1.0 U/ml) stimulated platelets were inhibited (Th 0.1 U/ml: 4.0 +/- 0.9-2.4 +/- 1.0/control, P<0.05), but positive staining for GP IIb-IIIa complex did not alter significantly. (3) Ca(2+) influx induced by thrombin decreased (Th 0.3 U/ml: 345 +/- 29-298 +/- 24 nmol/l, P<0.05). The baseline [Ca(2+)](i), the release of Ca(2+) from internal stores induced by thrombin and the size of internal Ca(2+) stores did not alter. (4) platelet c-AMP increased (Th 0.3 U/ml: 66.4 +/- 9.4-82.6 +/- 13.0 fmol/l, P<0.05), but platelet nitrite/nitrate (NO(x)) or c-GMP did not alter significantly. CONCLUSIONS: These results suggest that modulation of platelet function by decreasing Ca influx and increased production of c-AMP may account in part for the cardiovascular benefit of ERT.

Blood Platelets↗

PubMed2002

A frameshift mutation of beta subunit of epithelial sodium channel in a case of isolated Liddle syndrome.

BACKGROUND: Liddle syndrome is an autosomal dominant form of salt-sensitive hypertension caused by mutations in the epithelial sodium channel expressed in the distal nephron playing an essential role in Na absorption. All reported mutations in Liddle syndrome are either missense mutations or frameshift mutations destroying the PY motif closer to the C-terminus of the beta or gamma subunits causing the situation that the epithelial sodium channels are not degraded and sodium is pooled and thus hypertension and hypokalemia are caused. METHODS: We sequenced the C-terminus of the beta or gamma subunits of the epithelial sodium channel in a Japanese family of a patient clinically diagnosed as having Liddle syndrome. RESULTS: As a result, we found in the proband, a frameshift mutation of the beta subunit caused by a single cytosine insertion at the codon 595, introducing a new stop codon at 605 and deleting the last 34 amino acids from the normally encoded protein. CONCLUSION: This mutation is carried by neither parent (with paternity proven) and hence confirms this has occurred as a event within this family.

Adolescent↗

PubMed2002

Guidewire bias in rotational atherectomy in the angled lesion: evaluation based on the thickness of the ablated intima and media.

The effect of guidewire bias on angled-lesion ablation by rotational atherectomy (RA) was assessed by measuring the changes in vertical lumen diameter, horizontal lumen diameter and the intima-media thickness of the coronary artery, using intravascular ultrasound in 10 lesions with an angle greater than 10 degrees. The vertical and horizontal diameters significantly increased after RA. The intima-media thickness at the 4 orthogonal sites significantly decreased. There was a significant positive correlation between vertical diameter change and angle (r=0.642, p=0.045), but none between horizontal diameter change and angle. There was no correlation between intima-media thickness change at 0 degrees and angle; however, at 180 degrees there was a tendency to correlation with angle (r=0.602, p=0.066). These data suggest that in cases of angled lesions, the increase in vertical lumen diameter is caused more by ablation of the 180 degrees wall than by that of the 0 degrees wall, which is brought about by guidewire bias toward the vascular wall at 180 degrees.

Angina Pectoris↗

PubMedDate not supplied

Quantitative detection of carcinoembryonic antigen messenger RNA in the peritoneal cavity of gastric cancer patients by real-time quantitative reverse transcription polymerase chain reaction.

BACKGROUND: Peritoneal dissemination is the most frequent cause of recurrence in gastric cancer patients after gastrectomy. We have previously demonstrated the prognostic factors in gastric cancer including growth factors and their receptors and intra-peritoneal CEA (1,2). MATERIALS AND METHODS: In the present study, to elucidate whether CEA mRNA in peritoneal lavage is a good marker for the prediction of peritoneal recurrence of gastric cancer patients, quantitative real-time RT-PCR with primers specific for CEA was performed by peritoneal lavage of 124 gastric cancer patients collected at the time of operation. RESULTS: CEA crossing-point values (CEA-CP) were significantly correlated with the depth of tumor invasion and the values were cut-off at 27.11, which was the minimum value of mucosal cancer patients. The CEA-CP was significantly correlated with lymph node metastasis, lymphatic invasion, venous invasion, stages and overall survivals. In prediction of peritoneal recurrence by CEA-CP, sensitivity and specificity were 76.9% and 67.7%, respectively. Cytology predicted peritoneal recurrence with 23.1% sensitivity and 98.1% specificity. CONCLUSION: Quantitative RT-PCR of CEA mRNA of peritoneal lavage is a useful factor for prognosis and predicting peritoneal recurrence.

Biomarkers, Tumor↗