PubMed Health⌕ Search

Biomedical subjects

J Shibuya

Publications and source records attributed to J Shibuya.

At least 19 recordsLinked to original sources
PubMed1999

Increased function of the voltage-dependent calcium channels, without increase of Ca2+ release from the sarcoplasmic reticulum in the arterioles of spontaneous hypertensive rats.

It has been reported that the increased function of the voltage-dependent calcium channels (VDCC) in the artery is involved in the increase of peripheral resistance in hypertension, and that the sarcoplasmic reticulum (SR) in the artery plays an important role in preventing the development of hypertension via a buffering effect. However, no reports have described the role of VDCC and SR in resistance arterioles in the development or maintenance of hypertension. We investigated the function of VDCC and of SR in the cremaster arterioles of spontaneous hypertensive rats (SHR) and age-matched Wistar Kyoto rats (WKY). The changes in diameter and the intracellular calcium ion concentration ([Ca2+]i) in the microdissected arterioles, using fluorescent dyes, were measured with videomicroscopy. The KCl concentration-response curves were analyzed in 4- to 5- and 7- to 8-week-old SHR and WKY. The changes in the vascular diameter and [Ca2+]i in response to ryanodine, an alpha-1 adrenoceptor, and angiotensin-II stimulation were compared between the 7- to 8-week-old SHR and WKY. We found an increase in the Ca2+ influx by VDCC in the early hypertensive stage, but not in prehypertensive SHR. However, after the onset of hypertension, there were no significant differences from WKY in the SR function mediated by Ca2+-induced Ca2+ release or inositol 1,4,5-trisphosphate-induced Ca2+ release. In conclusion, an increased influx of Ca2+ in the cell membrane, without a buffering effect of SR, was associated with progression of hypertension in the cremaster arterioles of SHR.

Animals↗
PubMed1999

Integrating cultural values, beliefs, and customs into pregnancy and postpartum care: lessons learned from a Hawaiian public health nursing project.

Determining the elements of culturally competent health care is an important goal for nurses. This goal is particularly integral in efforts to design better preventive health care strategies for pregnant and postpartum women from multiple cultural and ethnic backgrounds. Learning about the values, beliefs, and customs surrounding health among the targeted groups is essential, but integrating this knowledge into the actual health care services delivery system is more difficult. The success of a prenatal and postpartum program developed for native Hawaiian, Filipino, and Japanese women in Hawaii has been attributed to the attention on training, direct care giving, and program monitoring participation by local cultural and ethnic healers and neighborhood leaders living in the community, with coordination by public health nurses. This article profiles central design elements with examples of specific interventions used in the Malama Na Wahine or Caring for Pregnant Women program to illustrate a unique approach to the delivery of culturally competent care.

Adult↗
PubMed1999

A decrease in the amount and function of inhibitory GTP-binding protein in the resistance small artery from spontaneously hypertensive rats.

The inhibitory GTP-binding protein (Gi protein) plays an important role in regulation of vascular tone. Many studies have implicated the role of Gi protein in conduit vessels. However, the physiological role of Gi protein in the control of peripheral microvascular tone in hypertension has not been established yet. Therefore, we investigated the concentration of Gi protein in the peripheral resistance arteries and aorta in the spontaneously hypertensive rats (SHR), normotensive Wistar-Kyoto rats (WKY) and renovascular hypertensive rats (RHR), using immunohistochemical methods semiquantitatively. Changes in the function of Gi protein in relation to alpha2-adrenoceptor were also investigated by microcannulation techniques. We have shown that the amount of alpha2 subunits of Gi protein in the cremaster small artery was significantly lower in SHR aged 4 weeks and older than in age-matched WKY and that there were no significant differences between RHR and WKY. We also demonstrated that the function of Gi protein in relation to alpha2-adrenoceptor was already lower in SHR before the onset of hypertension. The quantitative and functional decline in Gi protein in the smooth muscle cells of peripheral small arteries were observed in SHR even before the onset of hypertension, whereas rats with secondary hypertension did not exhibit this finding.

Aging↗
PubMed1998

Enhanced myogenic response in resistance small arteries from spontaneously hypertensive rats: relationship to the voltage-dependent calcium channel.

To characterize the myogenic response during the development of hypertension, we evaluated the myogenic response of small arteries isolated from the cremaster muscle of spontaneously hypertensive rats (SHR) aged 4-5 and 7-8 weeks, as compared with age-matched Wistar-Kyoto rats (WKY), using an in vitro system. The myogenic response of SHR aged 7-8 weeks (but not those aged 4-5 weeks) significantly exceeded that of WKY. Measurement of intracellular levels of free calcium ([Ca2+]i) in small arteries of the 7-8-week-old SHR and WKY loaded with a calcium-sensitive dye showed that the increase in [Ca2+]i in SHR was significantly greater than that in WKY during the myogenic response. The inhibitory effects of nitrendipine on the increased myogenic response and [Ca2+]i were greater in SHR. Thus, the myogenic response was enhanced in SHR and may be explained in part by an increase in Ca2+ entry through the voltage-dependent calcium channel (VDCC). The myogenic response and Ca2+ entry through the VDCC may be increased in association with the elevation of blood pressure.

Animals↗
PubMed1998

Stimulatory guanine nucleotide-binding protein in failing heart of hamsters and rats.

The role of the stimulatory guanine nucleotide-binding protein (Gs) in heart failure is unclear. We therefore determined the amount of protein and mRNA of Gs in the failing myocardium using two animal models: the BIO 53.58 hamster, a model of genetic cardiomyopathy, and adriamycin-treated rats (ADR rats), a model of secondary cardiomyopathy. The maximal number of myocardial beta-adrenoceptors in the BIO 53.58 hamsters as well as in the ADR rats was significantly lower than that in the respective controls, indicating that the beta-adrenoceptors were down-regulated in heart failure. Analysis by Western blot and Northern blot revealed a significant decrease in Gs protein and mRNA in the BIO 53.58 hamsters relative to the control. There were no differences in the level of Gs protein or mRNA in the ADR rats vs the controls. The functional activity of Gs was investigated by measuring adenylate cyclase activity. The activity of adenylate cyclase in response to stimulation by sodium fluoride or forskolin was decreased in the BIO 53.58 hamsters relative to control animals, whereas no differences were observed in the ADR rats vs the controls. Thus, alterations in Gs in the failing heart appear to differ according to its cause.

Adenylyl Cyclases↗
PubMed1995

Messenger RNA for the guanine nucleotide-binding regulatory protein (G protein) is reduced in the acute ischemic myocardium.

It has been reported that the function of the guanine-binding regulatory protein (G protein), especially the alpha subunit of the stimulatory G protein (Gs alpha), in myocardium is decreased with acute ischemia. However, it is unclear whether this decrease is due to transcriptional or post-transcriptional changes. Moreover, no studies have examined the distribution of G protein mRNA in ischemic myocardium using in situ hybridization. The purpose of this study was to explore alterations in mRNA of G proteins (Gs and Gi) in ischemic hearts using in situ hybridization. We measured the levels of mRNA for Gs alpha and Gi alpha in ischemic and non-ischemic myocardium by in situ hybridization using a radioisotope imaging system. We compare these mRNA levels in ischemic and non-ischemic myocardium with Northern blot analysis and the protein levels of G proteins by Western blot analysis. The mRNA for Gs alpha and Gi alpha was distributed diffusely in normal hearts. Levels of mRNA detected by in situ hybridization were substantially reduced by acute ischemia, and these results were confirmed by Northern and Western blot analysis. These results suggest that decreased levels of mRNA and protein for G proteins may underlie the impaired function of the receptor--G protein--adenylate cyclase system in ischemic myocardium. In addition, quantitative evaluation of mRNA is possible by in situ hybridization and correlates well with Northern analysis.

Acute Disease↗
PubMed1995

[Surgical treatment of lung cancer over 80 years of age: investigation from post operative complications].

Seventeen patients with lung cancer over 80 years were treated surgically from 1983 through 1993 in our department. Thirteen patients were male and four were female. The histology of the tumor was adenocarcinomas, squamous, large and small cell carcinomas, in 9, 6, 1 and 1 cases, respectively. More than single lobectomy was performed in each patient. Unilateral pulmonary occlusion test was applied in patients whose expected contralateral FEV1.0/BSA was less than 800 ml.m2, or expected residual FEV1.0/BSA was less than 850 ml.m-2. Postoperative cardiovascular complications, such as PAT, PAC, PVC or Af, were seen in 9 patients, respiratory problems, namely, sputa retention, retained secretions or atelectasis, in 7 patients. Blood chemistry and hematology were performed for about three weeks after operations, and found increases in serum transaminases, and leukocytosis. However, there were no operative death. We conclude that some patients over 80 years of age are candidates for surgery after careful cardiopulmonary preoperative evaluation.

Adenocarcinoma↗
PubMed1994

[A case of lung cancer combined with ocular myopathy and idiopathic thrombocytopenic purpura which was presumed to be caused by heart catheterization].

A 61-year-old patient was admitted to our hospital because of a chest abnormal shadow. He was suffered from ocular myopathy for more than 4 years. A lab data on the admission showed only a slight thrombocytopenia. After the unilateral pulmonary arterial occlusion test for the preoperative evaluation of thoracotomy, the hemorrhagic tendency was appeared. A detailed examination proved idiopathic thrombocytopenic purpura which was presumed to be caused by the heart catheterization. We employed high-dose intravenous gamma-globulin infusion and concentrated platelet transfusion for 5 days for preventing hemorrhagic complications during the thoracotomy. The partial resection was undergone for the left upper lobe tumor, which was proved as large cell carcinoma. The postoperative hemorrhage was well controlled. We conclude that the high-dose intravenous gamma-globulin infusion and/or concentrated platelets transfusion should be positively employed for the patients with even slight thrombocytopenic purpura.

Carcinoma, Non-Small-Cell Lung↗
PubMed1993

[Changes in right ventricular hemodynamic function by unilateral pulmonary arterial occlusion test].

We performed unilateral pulmonary arterial occlusion test (UPAO) for the preoperative evaluation of lung function in patients undergoing lung resection. In this test, the main pulmonary artery of either side is occluded to simulate postoperative functional status. In order to evaluate the right ventricular hemodynamic function, we measured right ventricular ejection fraction (RVEF) and right ventricular end-diastolic volume index (RVEDVI) throughout UPAO by thermodilution method. We investigated the relationships between changes in right ventricular hemodynamic function and postoperative complications related to cardiac functions, namely arrhythmias or heart failure. Thirty-four patients without heart disease prior to lung resection were examined by UPAO, and RVEF and RVEDVI were measured. Analyses demonstrated that changes in RVEF were inversely correlated with changes in RVEDVI. In 6 cases, RVEDVI increased from control by over 20% during UPAO. All of these patients had postoperative cardiac complications. The hypothetical ventricular function curves showed a large increase in RVEDVI relative to right ventricular stroke work index (RVSWI), suggesting a decrease in right ventricular function. In conclusion, these results suggest that changes in RVEDVI during UPAO may predict postoperative cardiac complications in patients undergoing pulmonary resection.

Adult↗
PubMed1993

[Chronic pulmonary mucormycosis diagnosed by bronchoscopy: a case report].

A 56-year-old man with bronchial asthma and diabetes was admitted with massive hemoptysis and thick-walled cavity in the right middle lung field on chest X-ray films. He had been treated with antibiotics for eight months under the diagnosis of lung abscess before his admission. After occlusion of the bronchial arteries with metallic coils, bronchofiberscopy was performed disclosing the obstruction of right B3b. Microscopic examination of bioptic material and bronchial brushing smear taken from right B3b yielded numerous broad, nonseparate hyphae. Right middle and lower lobectomy were performed under a diagnosis of chronic pulmonary mucormycosis. The patient was recovered and discharged on 55 th days after operation.

Biopsy↗
PubMed1993

[Extension of functional limitation for surgery of lung cancer by unilateral pulmonary arterial occlusion test].

We performed unilateral pulmonary arterial occlusion test to determine the indication for lung resection functionally, and investigated 32 cases whose total pulmonary vascular resistance was over 700 dyne.sec.cm-5/M2. Thirteen out of 32 cases underwent surgery. There was no difference in lung function tests between surgical and non-surgical cases. Nine out of 12 cases whose pulmonary vascular resistance was less than 800 dyne by unilateral pulmonary arterial occlusion test underwent surgery, and none of these cases died within 3 months after surgery. In non-surgical cases, two were aged patients and one had chronic renal failure. Four out of 20 cases whose total pulmonary vascular resistance was over 800 dyne underwent surgery. Two cases that underwent surgery died within 3 months after surgery. These results suggest that the functional limitation of lung resection can be extended from 700 dyne.sec.cm-5/M2 to 800 dyne.sec.cm-5/M2 total pulmonary vascular resistance by application of unilateral pulmonary arterial occlusion test.

Aged↗
PubMed1992

Adaptation themes for prenatal care delivered by public health nurses.

An adaptation process involving three cognitive themes provides the framework for community nursing model for prenatal care on the island of Hawaii. The themes are based on the cognitive adaptation model developed by Taylor (1983) and include search for meaning, sense of mastery, and self-esteem. Each theme is used to guide public health nurses and is identified during designated encounters between the nurse and woman throughout the duration of prenatal care. A focus on adaptation themes for each trimester of pregnancy expands on the medical model of prenatal care to highlight developmental processes of childbearing and broaden the scope of practice for public health nurses responsible for assessment and intervention in the community.

Adaptation, Psychological↗
PubMed1992

The first report of a case with acute myocardial infarction showing familial deficiency of creatine kinase.

A 46-year-old male patient was diagnosed as suffering from acute myocardial infarction, but his serum creatine kinase (CK) level was extremely low and no CK isozymes were detected in the serum. The total CK activities in the skeletal muscle amounted to only 2% of that of the control. Electrophoresis of the CK isozymes in the skeletal muscle showed that CK-MM was absent but the CK-BB and abnormal isozyme bands were present. There was no evidence of myocardial ischemia, although the exercise treadmill test revealed ST segment depression in the chest leads. One of the patient's sisters had an extremely low serum CK level suggesting inheritance of this abnormality. This is the first report of a case showing familial deficiency of CK.

Creatine Kinase↗
PubMed1992

[Surgery for the patients whose total pulmonary vascular resistance was over 700 dyne during unilateral pulmonary artery occlusion test].

To determine the indication for surgery from the point of pulmonary function, we have performed the unilateral pulmonary artery occlusion test in lung cancer patients. In these patients, we gave a surgery in 13 cases whose total pulmonary vascular resistance were over 700 dyne.sec.cm-5/M2 per body surface area. The pulmonary hemodynamics before and during pulmonary artery occlusion were 549 +/- 82 and 798 +/- 78 dyne.sec.cm-5/M2 in total vascular resistance, 18.7 +/- 3.8 and 27.2 +/- 4.3 cmHg in mean pulmonary arterial pressure and 2.69 +/- 0.36 and 2.73 +/- 4.3 L/min/M2 in cardiac index respectively. In 7 cases out of 13, we performed selective pulmonary artery occlusion test. In pulmonary function test, 10 cases had a chronic obstructive diseases, 2 cases had a disturbance of diffusion and one case has a contractive disease. We gave a lobectomy in 12 cases and completion pneumonectomy in one case. Two of lobectomy cases died in the early phase: 42 and 72 days after surgery due to pulmonary complications. One of these cases needed an additional completion pneumonectomy because of bronchial fistel. Surgical complications were seen in 12 cases. These 13 cases used to be recognized that they have no indication of surgery because of low pulmonary function, however it revealed that we can give a lobectomy through a high intensive care after surgery.

Adenocarcinoma↗
PubMed1991

[Evaluation of cardio-pulmonary function for lobectomy under the condition of selective pulmonary arterial occlusion test (SPAO)].

We performed selective pulmonary arterial occlusion test (SPAO) and unilateral pulmonary arterial occlusion test (UPAO) in 30 patients with lung cancer who would be undertaken right lower lobectomy or middle and lower lobectomy, and evaluated the preoperative cardio-pulmonary function. The lung hemodynamics during SPAO were different from those during UPAO. This indicates that SPAO evaluated reserve capacity of vascular bed in the right upper lobe which would be remained at the surgery. Moreover, the ratio of total pulmonary vascular resistance during SPAO to that of before SPAO was not differed in two groups, one was a group with and the other was a group without impaired reserve capacity of vascular bed in the contralateral lung. This suggests that reserve capacity of pulmonary vascular bed including right upper lobe would be well compensated even in the patients with highly impaired capacity in the contralateral lung. Based on these findings, we performed lung resections in 9 patients, who were judged contraindications for lung resection by the results of UPAO, and no patient suffered postoperative cardio-pulmonary complications. Total pulmonary vascular resistance immediately after the right middle and lower lobectomy were equal to those during SPAO. Thus we conclude that SPAO is very useful technique for evaluating cardiopulmonary function after right lower lobectomy or middle and lower lobectomy, and that it would be possible to extend the boundaries of safety for lung resection based on evaluation of cardio-pulmonary function by SPAO.

Aged↗
PubMed1990

[Activated pulmonary intravascular macrophages increase pulmonary microvascular permeability in sheep].

Pulmonary intravascular macrophages (PIMs) reside in the alveolar capillaries of sheep lung. However, the role of PIMs activation in the mechanism of increasing pulmonary microvascular permeability is not clear. We determined, using awake sheep with chronic lung lymph fistulas, the effects of intraarterial infusion of latex beads emulsion (1 microns in diameter) on lung lymph-dynamics. Sheep were divided into 3 groups; control, low dose latex and high dose latex groups. In control group, their lymph-dynamics were stable during the experimental period. In low dose latex group (5.46 x 10(9) beads/kg), lung lymph flow increased during the infusion period, but lung lymph protein clearance did not change. In high dose latex group (5.46 x 10(10) beads/kg), lung lymph flow began to increase during the infusion period and remained high, and lung lymph protein clearance increased significantly during and after the infusion of latex beads emulsion. The latex beads mainly distributed to lungs, and 70% of the beads were caught by PIMs in their phagosomes. These findings suggest that the activation of PIMs through their phagocytic uptake of circulating microparticles increases pulmonary microvascular permeability.

Animals↗