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Biomedical subjects

H Hirose

Publications and source records attributed to H Hirose.

At least 307 records · Page 17Linked to original sources
PubMed1989

[Emergency aortocoronary bypass grafting].

We evaluated operative results of emergency aortocoronary bypass grafting in 17 patients (surgical group) with impending myocardial infarction or acute myocardial infarction, and compared them to those of medical therapy in 16 patients (medical group) required IABP with same condition. Mortality in surgical group is significantly lower than that in medical group. In patients with severe coronary artery disease, mortality in surgical group is significantly lower than that in medical group. In patients with severe left ventricular dysfunction, mortality in surgical group is significantly lower than that in medical group. The period using IABP before the operation in expired patients is longer than that in survived patients. These data indicate that emergency operation should be performed immediately after IABP in patients with severe coronary artery disease or severe left ventricular dysfunction.

Aged↗
PubMed1989

Extended operation for lung cancer invading the aortic arch and superior vena cava.

Extended operation for lung cancer and mediastinal carcinoma involving the aortic arch or superior vena cava was performed in six patients. In three patients with lung cancer invading the right side of the mediastinum, sleeve pneumonectomy (two patients) or sleeve lobectomy was followed by resection and reconstruction of the superior vena cava with ringed polytetrafluoroethylene grafts. One patient with squamous cell carcinoma and T4 N1 M0 disease was alive and free of disease more than 34 months after the operation. The other patients with adenocarcinoma (T4 N1 M0) and adenosquamous cell carcinoma (T4 N2 M0) died 18 and 5 months after the operation of systemic metastases. In two patients with invasion of lung cancer into the left side of the mediastinum, resection and reconstruction of the aortic arch and left common carotid artery were performed by a femoro-femoral bypass. These patients had adenocarcinoma (T4 N2 M0) and large cell carcinoma (T4 N1 M0) and died of systemic metastases and bleeding during reoperation 12 and 4 months after the initial operation. In one patient with mediastinal squamous cell carcinoma, resection and reconstruction of the aortic arch and left subclavian artery were performed by application of a temporary bypass graft between the ascending and descending aorta. This patient was alive and free of disease more than 17 months after the operation.

Adult↗
PubMed1988

Wall structure of arteriovenous anastomoses in the rabbit ear. Combined light-, scanning- and transmission electron-microscopic studies.

The wall structure of arteriovenous anastomoses in the rabbit ear was investigated. (1) Clusters of epithelioid smooth muscle cells form 3-4 longitudinally oriented plicae. The channel shows a single, irregularly outlined lumen, and its wall is very thin between adjacent plicae. (2) Endothelial cells covering the plicae protrude into the lumen, thus suggesting active contraction or shortening of the plicae. (3) The tunica adventitia is composed of 4-6 sheaths of flat fibroblasts, which may serve as a barrier to prevent loss of neurotransmitters. Processes of some of the fibroblasts also extend into the tunica media. (4) The tunica media is composed of an outer circular layer of typical smooth muscle cells, and an inner longitudinally running plica of ramified smooth muscle cells. Wide intercellular spaces between these ramified cells are filled with collagen fibrils, microfibrils, amorphous intercellular substances, and fibroblasts. Fibroblasts form close membrane contacts with each other, and with the smooth muscle cells. (5) Fibroblasts and other connective tissue components may function as an elastic support during active motility of the anastomotic channel.

Animals↗
PubMed1988

NMR-invisible ATP in rat heart and its change in ischemia.

The subcellular compartmentalization of adenosine 5'-triphosphate (ATP) in isolated perfused rat heart and its relation to energy depletion in ischemia were examined by 31P nuclear magnetic resonance (31P-NMR) spectroscopy and chemical analyses. The signal intensities of the beta-phosphate of ATP and creatine phosphate in the 31P-NMR were standardized by the intracellular volume ratio measured with 23Na-NMR to determine the actual content of each. During aerobic perfusion the ATP content determined by NMR (13.7 +/- 2.2 mumol/g dry weight) was significantly lower than that found by chemical analysis (22.4 +/- 0.7 mumol/g dry weight), while the creatine phosphate contents determined by the two methods were the same. During ischemia at 33 degrees C, the signal of the beta-phosphate of ATP in the 31P-NMR spectrum decreased progressively, disappearing completely after 16 min. But at this time 5.7 +/- 1.7 mumol/g dry weight of myocardial ATP was still detected by chemical analysis. These results indicated that there were two different compartments of intracellular ATP in the heart, only one of which is detectable by 31P-NMR spectroscopy, and that during ischemia the ATP that is detectable, which seems to be the free ATP in the cytosol, decreased more rapidly than the ATP in the other compartment.

Adenosine Triphosphate↗
PubMed1988

The mechanism of discordant xenograft rejection.

The mechanism of discordant xenograft rejection using the guinea pig-to-rat heart graft model was studied. In this model, we found that (A) Rejection occurred rapidly, in 17.5 +/- 8.3 min (mean +/- SD) (n = 8). (B) The graft survived longer when the recipient rat was pretreated with cobra venom facter (CVF). (C) Complement hemolytic titers in serum showed significant reduction of C3 in rejection without consumption of C4 and C2, suggesting complement activation through the alternative pathway. (D) No natural antibodies were detected in this combination. Complement-dependent cytotoxicity (CDC) titer, and hemagglutination (HA) titer were lower than x1. (E) Histological examination of the rejected heart xenograft revealed a large area of myocytolysis without interstitial cellular infiltration. (F) In vitro experiments showed that rat complement attacked guinea pig erythrocytes (Egp) via the alternative pathway. These findings indicate that rejection in this discordant xenograft model of guinea pig-to-rat was caused by primary activation of complement via the alternative pathway.

Animals↗
PubMed1988

Use of a paracorporeal pneumatic ventricular assist device for postoperative cardiogenic shock in two children with complex cardiac lesions.

Pneumatic ventricular assist device (VAD) was utilized for cardiogenic shock after intracardiac operation in two children with complex cardiac anomalies based with single ventricle. In the first case (a 10-year-old), after a modified Fontan operation, VAD was placed between the functional left atrium and ascending aorta, serving as a "artificial single ventricle" with neither pumping chamber nor artificial support in the right side of the heart. The systemic circulation was maintained by keeping relatively high central venous pressure. In another child (a 3-year-old) who underwent repair of incompetent atrioventricular valve leaving intracardiac lesions, VAD was placed between the common atrium and ascending aorta, serving as a pump for both pulmonary and systemic circulation with regulation of pulmonary blood flow through an aortopulmonary Gore-Tex shunt. The circulatory assist with VAD was utilized for 5 and 6 days, respectively. Although weaning from the device was not feasible in both patients because of the pulmonary dysfunction, these experience showed the possible use of VAD for cardiogenic shock after surgery in patients with complex cardiac anomalies.

Assisted Circulation↗
PubMed1988

Assessment of prostacyclin and thromboxane A2 release during reperfusion after global ischemia induced by crystalloid cardioplegia--comparison between warm and cold ischemia.

The metabolites of prostacyclin (PGI2) and thromboxane A2 (TxA2), 6-keto-PGF1 alpha and thromboxane B2 (TxB2), were investigated during reperfusion (RP) following warm (37 degrees C, 60 min, n = 9) or cold (15 degrees C, 120 min, n = 11) ischemia induced by cold (4 degrees C) or normothermic (30 degrees C) K+ cardioplegia (CP) in isolated canine hearts subjected to global ischemia and RP. 6-Keto-PGF1 alpha flux was significantly higher (p less than 0.025) in the warm group at 1, 5, and 10 min of RP (4,202 +/- 1,412, 2,475 +/- 1,875, and 1,255 +/- 633 pg/g.min, mean +/- SD) compared to those in the cold group (1,504 +/- 1,245, 434 +/- 641, and 370 +/- 329 pg/g.min). TxB2 flux was small in amount compared to 6-keto-PGF1 alpha in both groups. Regarding the coronary hemodynamics, the cold group alone showed statistically significant relationships of coronary sinus blood flow to TxB2 level and TxB2/6-keto-PGF1 alpha ratio in coronary sinus blood. Also, coronary vascular resistance showed linear relations to these two parameters of the metabolites. In a supplementary experiment only with cold ischemia for 180 min, 6-keto-PGF1 alpha was released at each coronary flush-out by CP and the incremental amount showed a gradual increase during ischemia. These results indicated that significant production and release of PGI2 occurred during ischemia and RP following CP arrest and these related to the degree of myocardial damage while the response of TxA2 seemed less significant. The role of PGI2 release during RP following cardioplegic arrest was discussed.

6-Ketoprostaglandin F1 alpha↗
PubMed1988

Quantitative cineangiographic analysis of ventricular volume and mass in patients with single ventricle: relation to ventricular morphologies.

With the use of biplane selective ventriculography, the ventricular volume, ejection fraction, and ventricular mass were evaluated in 28 patients with a single ventricle, and those with the left ventricular type (LV type, 12 patients) and right ventricular type (RV type, 16 patients) were compared. There were no significant differences in terms of age, hemoglobin, systemic oxygen saturation, or pulmonary-to-systemic flow ratio in the two groups. No patients with atrioventricular valve regurgitation were included. The ventricular cavity volume was calculated by the area-length method. The ventricular mass volume was determined as the shell volume created by subtracting the ventricular cavity volume from the total ventricular volume calculated by adding the free wall thickness to the chamber dimensions. The ventricular mass volume was converted to mass by multiplying by the gravity of the heart muscle. There was no significant difference between patients with the LV type and RV type of single ventricle with respect to the end-diastolic ventricular volume (188 +/- 53 and 179 +/- 61 ml/m2 in LV and RV types, respectively), end-systolic volume (88 +/- 31 and 84 +/- 27 ml/m2), or ejection fraction (0.54 +/- 0.06 and 0.52 +/- 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Volume↗
PubMed1988

High-speed digital imaging of vocal fold vibration.

A new method of digitally imaging vocal fold vibration using a solid-state image sensor attached to a conventional camera system is reported. The obtained image signals are stored in an image memory in combination with a personal computer through a high-speed A/D converter. The maximum frame rate for analysis is 4000 fps. After storage of data, images can be reproduced and displayed on a monitor screen as a form of slow-motion display. The system has proved useful for clinical examination of pathological vocal fold vibration.

Analog-Digital Conversion↗
PubMed1988

Naproxen sodium: comparative efficacy and tolerability of two dosages for pain after joint surgery.

In a multicenter, randomized, double-blind, parallel trial, the efficacy and tolerability of two regimens of naproxen sodium were compared in a two-day treatment of moderate to severe pain following open surgery of the hip, shoulder, knee, and ankle joints. Of 147 patients enrolled, the data of 99 were valid for efficacy analysis, 45 in the low-dose regimen (day 1, 1,100 mg; day 2, 825 mg) and 54 in the high-dose regimen (1,650 mg/day). At 12 interviews each day, patients evaluated intensity of pain using numerical scales and recorded complaints. At the end of the study, overall efficacy was evaluated. Although there were no statistically significant differences between the two regimens for efficacy or tolerability, the high-dose regimen achieved greater pain relief in patients who had hip or shoulder surgery, suggesting that this regimen had greater cumulative efficacy for these patients.

Adult↗
PubMed1988

Subluxation of the patella. Computed tomography analysis of patellofemoral congruence.

Fifty patients who had patellar subluxation and thirty control subjects were examined using axial roentgenograms of the patellofemoral joint that were made with the knee in 30 and 45 degrees of flexion, as well as computed tomography scans that were made with the knee in full extension. The amount of lateral patellar tilt was quantitatively assessed using the lateral patellofemoral angle, as described by Laurin et al., and the congruence angle, as described by Merchant et al. In both the control subjects and the patients, the angle of Laurin et al. changed significantly when the knee was flexed from full extension to 30 degrees. The difference between the groups was statistically significant at each angle of flexion of the knee, and the difference between the groups was most prominent on the computed tomography scans that were made with the knee in full extension (p less than 0.001). In the patients, the average congruence angle (as described by Merchant et al.) was 5 degrees and in the control subjects, -10 degrees. This indicated that, in our patients, the extent of the patellar subluxation was less than that in previously reported series, and, as a result, the sensitivity of the congruence angle in diagnosing patellar subluxation was only 0.30. In contrast, the sensitivity and specificity of the computed tomography scans for diagnosing patellar subluxation were 0.96 and 0.90, respectively--that is, they were higher than the values that were obtained using any axial roentgenograms. Thus, our results indicated that patellar subluxation can be detected more accurately by using computed tomography with the knee in full extension than by using conventional axial roentgenograms.

Adolescent↗