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Biomedical subjects

H Mohri

Publications and source records attributed to H Mohri.

At least 181 records · Page 10Linked to original sources
PubMed1991

Mapping of ATP-dependent trypsin-sensitive sites on the beta chain of outer-arm dynein from sea urchin sperm flagella.

The beta chain of sea urchin outer-arm dynein showed a peculiar tryptic digestion pattern in the presence of ATP (or ADP) plus Vi. Examination of the molecular mass of the products formed by photocleavage of tryptic fragments indicated that the trypsin-sensitive sites on the 165-kDa ATP-binding polypeptide in the presence of ATP and Vi are located 15 kDa apart from its amino-terminus, 2 kDa apart from its carboxy-terminus, and near the middle portion between the adenine- and gamma-Pi-binding sites. On the other hand, the carboxy-terminal region of the beta chain, the 135-kDa polypeptide, was cleaved into a 96-kDa polypeptide by tryptic digestion in the presence of ATP and Vi. Peptide mapping of 135-kDa, 96-kDa, and carboxy-terminally truncated polypeptides of the 135-kDa polypeptide revealed that the 96-kDa region is located at the amino-terminal portion of the 135-kDa region. These results indicate that the changes of trypsin susceptibility of dynien beta chain caused by binding ADP and Vi occur not in local region but over an extensive region on the beta chain.

Adenosine Triphosphate↗
PubMed1991

Zeta potential of human X- and Y-bearing sperm.

The zeta potential of human X- and Y-bearing sperm was measured by two different methods: (i) using an electrophoretic light scattering spectrophotometer, and (ii) using a laser-rotating prism. The X- and Y-bearing sperm were separated by free-flow electrophoresis, and their purities were determined by staining for the F-body using quinacrine mustard. The zeta potential of the sperm in the fraction containing more than 80% Y-bearing sperm was approximately -16 mV, whereas that of sperm in the fraction containing more than 95% X-bearing sperm was approximately -20 mV. In other words, the net negative-charge on the cell surface of human X-bearing sperm is higher than that of Y-bearing sperm.

Cell Separation↗
PubMed1991

[Effects of mecobalamin on testicular dysfunction induced by X-ray irradiation in mice].

Experimental testicular dysfunction were produced by X-ray irradiation to the testes in mice. Mecobalamin (CH3-B12) was orally administered at a daily dose of 0.01, 0.1 or 1 mg/kg six times a week for 8 weeks from the next day after the irradiation. The control mice received physiological saline in the same manner. On 4th- and 6th-week after the irradiation, the weights of testes and epididymides were decreased, although those of the body and accessory sex glands (seminal vesicle, coagulating gland and prostate) were nearly equal to those of non-irradiated mice. At the same time, the diameter of seminiferous tubules decreased and sperm parameters (sperm count, sperm motility and sperm abnormality) deteriorated. When CH3-B12 (1 mg/kg) was administered, the diameter of seminiferous tubules increased and sperm parameters improved as compared to those of the control. The results indicate that CH3-B12 improved the experimental testicular dysfunction in mice induced by the irradiation. These results suggest that CH3-B12 might accelerate testicular function.

Administration, Oral↗
PubMed1991

[A case of total aortic replacement in a patient with Marfan's syndrome].

A 32-year-old male with Marfan's syndrome was admitted to our Department in June, 1989 due to severe back pain that was diagnosed as type III-b dissecting aneurysm. His infrarenal abdominal aorta and bilateral iliac arteries had been replaced in another clinic in 1984 due to true aortic aneurysm. Two years later, Carbrol's operation was performed in our Department for the late development of DeBakey type II dissecting aneurysm. DSA and CT studies indicated the need for total replacement of the entire remaining aorta, since diffuse and extensive dilatation of the false lumen and the presence of an intimal tear at the origin of the left carotid artery were demonstrated. The arch and upper descending thoracic aorta were replaced in June, 1989, and replacement of the total remaining thoracoabdominal aorta was carried out under left heart bypass on September 26, 1989. Abdominal branch arteries and intercostal arteries of the 9th to 11th levels were reattached to the graft as onlay patches. Hoarseness of voice was the only complication. The patient recovered uneventfully and returned to his job after discharge. Although the native aorta had been completely replaced, ambulatory monitoring of the patient's pressure and ECG, performed two months after the operation, showed the normal reflex.

Adult↗
PubMed1991

Sympathetic nerve activity during maintaining circulation with only left ventricular assist device.

Maintaining circulation with an left ventricular assist device (LVAD) alone during cardiac arrest until heart transplantation, was evaluated by the use of the sympathetic neurogram. To evaluate the influences of this method on autonomic nervous system, sympathetic neurogram was analyzed by power spectrum and coherence function. In acute animal experiments using mongrel dogs, LVAD were implanted. After the LVAD implantation, ventricular fibrillation was induced electrically. Renal sympathetic nerve activity (RSNA) was detected by the use of bipolar electrodes attached to the left renal sympathetic nerve. Values of squared coherence between the arterial pulse wave and RSNA were calculated. Under the condition of circulatory maintenance with LVAD, coherence at the cardiac rhythm frequency was decreased, and coherence at the LVAD pumping rhythm frequency was increased. These results suggest that the arterial pressure which was observed during maintaining the circulation with only LVAD contributed to sympathetic neurogram.

Animals↗
PubMed1991

[Treatment of aneurysms of the aortic arch].

Graft replacement therapy was employed in the treatment of 28 patients with aneurysms involving the aortic arch. Of the 28 patients, 14 had true aneurysms, 13 dissecting aneurysms, and 1 pseudoaneurysm. The operative mortality was 75% (6 of 8 patients) between 1979 and 1986, whereas it was 10% (2 of 20 patients) between 1987 and 1989. Temporary or permanent bypass with vascular graft or heparin coated tube were used in 10 patients (7 patients in the early period, 3 patients in the later period). In this group, 50% hospital mortality occurred. Cardiopulmonary bypass and separate cerebral circulation were used in 16 patients (1 case in the early period, 15 patients in the later period). Thirteen of 16 patients survived this technique. In 2 patients, both in later period, profound hypothermia and circulatory arrest were used. Two patients survived without neurological deficit. Operative mortality decreased since 1987 by the change of bypass technique and operative procedures.

Adult↗
PubMed1991

[Analysis of hepatic and renal dysfunction after surgery of thoracic aneurysm].

To analyze causes of postoperative hepatic and renal dysfunction in patients with thoracic aneurysm, we examined 31 patients who survived surgeries and 2 patients died of MOF. The patients were separated into three groups as follows; Cardiopulmonary bypass (CPB) was used for circulatory support in group A (n = 7), CPB and low flow perfusion during open distal anastomosis in group B (n = 13) and temporary bypass or left atrial distal aorta arterial bypass was used in group C (n = 11). Operation time was significantly longer in group A (9.8 hrs) compared with group C (6.1 hrs). Amount of intraoperative blood transfusion was greater in groups A (4980 ml) and B (4860 ml) compared with group C (2320 ml). Postoperative highest total bilirubin level was significantly greater in group A (7.8 mg/dl) than group C (2.5 mg/dl). LDH was higher in groups A (1322 IU/l) and B (1336 IU/l) than group C (991 IU/l). GOT was higher in group B (200 IU/l) than group C (64 IU/l). There were no significant differences in GPT, creatinine and BUN among the three groups. Operation time and amount of intraoperative blood transfusion were positively correlated with postoperative hepatic function parameters. Two patients died of MOF showed severe hepato-renal dysfunction associated with LOS. The results indicate that hypothermic low flow perfusion during open distal anastomosis do not induce hepatic or renal dysfunction, and postoperative hyperbilirubinemia is resulted from bilirubin overload which patients can tolerate well if they are not complicated with MOF.

Aged↗
PubMed1991

Improvement of the magnetneumometer.

We have improved the magnetneumometer in order to extend the measurement range and to make small-sized transmitting and receiving coils, for the purpose of applying it to measure the breathing rib cage and abdomen displacement. As a result, the measurement range is 10-80 cm, the noise level is less than 0.02 mm, and small and light coils (30 x 16 x 3 mm, 4 g) have been incorporated.

Abdomen↗
PubMed1991

[Tetralogy of Fallot with anomalous origin of unilateral pulmonary artery].

Between 1971 and 1988, 7 patients (pts) of TOF with anomalous origin of unilateral pulmonary artery (AOPA) underwent intracardiac repair at Tohoku University Hospital. They were 2 males and 5 females, with ages ranging from 4 to 26 years old. The right PA originated from the RV in all cases, whereas the left PA originated from the ascending aorta in 2 pts (Group 1) and from the ductus arteriosus in 5 pts (Group 2 & 3). In Group 2 (2 pts), the left PA was separated from the right PA with intraluminal membrane. In Group 3 (3 pts), there was no communication between both pulmonary arteries. The left PA was reconstructed in Group 1 & 2. However, it was impossible to reconstruct the left PA in Group 3 since the ductus arteriosus and left PA had been occluded before intracardiac repair. In Group 3, VSD was closed with one-way (RV----LV) valved patch for the aim of lowering RV pressure. Postoperative RV/Ao pressure ratio was 0.5-0.8 in the cases of Group 1 & 2, 0.8-1.0 in Group 3. Three patients (one in each group) died postoperatively due to low output syndrome. Autopsy revealed pulmonary vascular obstructive disease (PVOD) of the left lung in Group 1. It is concluded that TOF with AOPA should be corrected before the advance of PVOD in case PA originate from the ascending aorta, and before the occlusion of the ductus in case PA originate from it, in order to prevent postoperative RV overload.

Adolescent↗
PubMed1991

A clinical trial of allopurinol (Zyloric) for myocardial protection.

This study explored myocardial protective effects of allopurinol at various doses. Ninety patients undergoing coronary artery bypass or repair or replacement of cardiac valves were divided into three groups of 30 patients each in accordance with the amount of allopurinol administered to patients in each group. Patients in group I received no allopurinol, those in group II received low-dose allopurinol (total dose 1200 mg), and those in group III received high-dose allopurinol (total dose 2400 mg). Aspartate aminotransferase, cardiac isoenzyme of creatine kinase, and lactic dehydrogenase levels were measured up to 5 days after operation. Concentrations of allopurinol and oxypurinol were also measured before initiation of cardiopulmonary bypass and at the start and at the end of aortic crossclamping. Postoperative aspartate aminotransferase, creatine kinase, and lactate dehydrogenase 1 plus lactate dehydrogenase 2 levels in group III were significantly lower than those in groups I and II. Aspartate aminotransferase, creatine kinase, and lactate dehydrogenase 1 plus lactate dehydrogenase 2 levels in group II were lower than those in group I, without statistically significant differences. Plasma oxypurinol concentrations were significantly higher in group III than in group II. It was concluded that allopurinol had resultant high myocardial protective effects in dose-related fashion, but its effect might be attributed to oxypurinol levels formed by its degradation.

Aged↗
PubMed1990

Indications for open lung biopsy in patients with ventricular septal defect and/or patent ductus arteriosus with pulmonary hypertension.

In a previous paper, it was stated that open lung biopsy for determination of operative indications could be recommended if pulmonary vascular resistance (PVR) were higher than 8 units.m2 in patients with ventricular septal defect (VSD) and/or patent ductus arteriosus (PDA) with severe pulmonary hypertension. In the present study, oxygen inhalation or Tolazoline administration tests with or without occlusion of ductus arteriosus were performed during cardiac catheterization in 47 patients with VSD and/or PDA with severe pulmonary hypertension. The results obtained were compared with the operability based on our histopathological diagnostic criteria. There was no correlation between the oxygen, Tolazoline, or ductus occlusion hemodynamics and the baseline hemodynamics for better prediction of the biopsy should be performed for the determination of operative indication when patients with VSD and/or PDA have a PVR higher than 8 units.m2, and if the PVR is greater than 4 units.m2 with the oxygen inhalation test or 7 units.m2 with the Tolazoline test.

Adult↗
PubMed1990

The effects of 5% carbon dioxide on the quantitative analysis of long-term pathology of the brain after surface hypothermia.

To evaluate the effects of 5% carbon dioxide (CO2) administration for hypothermic circulatory arrest, neurological evaluation and pathological studies were carried out on the canine brain. Twenty-two dogs were assigned to five groups: Group 1: Three dogs without hypothermia were sacrificed as the control group. Group 2: Nine dogs were subjected to surface hypothermia (20 degrees C) under deep ether anesthesia with 100% oxygen (O2) and hyperventilation. Circulatory arrest time was 30 min in Group 2A and 60 min in Group 2B. Group 3: Ten dogs were surface cooled (20 degrees C) under deep ether anesthesia with a 95% O2 and 5% CO2 mixture. Thirty minutes of circulatory arrest was instituted in Group 3A and 60 min in Group 3B. Dogs in Groups 2 and 3 were surface rewarmed and kept alive until they were sacrificed electively 6 or more months later. Results were as follows: (i) Postoperative neurological disturbance was detected in only two dogs in Group 2B. (ii) The percentage of damaged nerve cells among the total nerve cells counted in the cerebral cortex of the frontal lobe was significantly greater in Groups 2A (22.4%), 2B (30.1%), 3A (19.6%), and 3B (22.2%) compared with Group 1 (7.1%). (iii) The number of glia cells per nerve cell in the cerebellar dentate nucleus was significantly higher in Group 2B (27.2) than in Groups 1 (11.8), 2A (16.7), 3A (17.9), and 3B (18.6). (iv) The number of Purkinje cells in a 10-mm length of the cerebellum was markedly reduced to 89 in Group 2B compared with 122, 134, and 117 in Groups 1, 2A, and 3A, respectively. In conclusion, the results of quantitative pathological brain analysis reflected the incidence of postoperative neurological disturbance and suggested that the administration of 5% CO2 could prolong the time limit for circulatory arrest.

Animals↗
PubMed1990

Conformational changes of the beta chain of the outer-arm dynein from sea urchin sperm flagella coupled with ATP hydrolysis.

Conformational changes of the beta chain of the outer-arm dynein from sea urchin sperm flagella in relation to ATP hydrolysis was examined by tryptic digestion. Tryptic digestion of the beta chain in the presence of 2 mM ATP (ADP) and 100 microM vanadate (Vi) or in the presence of 4 mM ATP gamma S produced different polypeptides from in the case of no addition. The difference was similar to the result previously reported for 21S outer-arm dynein heavy chains [Inaba, K. & Mohri, H. (1989) J. Biol. Chem. 264, 8384-8388]. Unlike the tryptic digestion pattern of 21S dynein heavy chains, however, the 135-kDa polypeptide was consistently produced from the beta chain, even in the presence of ATP (ADP) and Vi. The tryptic digestion pattern of the 21S particle reconstituted from the separated a chain, the beta/IC1 complex and the IC2/IC3 complex [Tang, W.-J.Y., Bell, C.W., Sale, W.S., & Gibbons, I.R. (1982) J. Biol. Chem. 257, 508-515] was similar to that of intact 21S dynein; the 135-kDa polypeptide was only slightly produced in the presence of ATP and Vi. The digestion rate constant of the 135-kDa polypeptide from the beta chain in the presence of ATP and Vi was significantly decreased as compared with in the case of 21S dynein or that of the reconstituted 21S particle. These results suggest that the trypsin sensitivity of the 135-kDa region of the beta chain changes with the association of the beta/ICI complex with the alpha chain and the IC2/IC3 complex in the presence of ATP and Vi.

Adenosine Triphosphate↗
PubMed1990

Serological and histological characterization of the new mutant strain of lpr mice, CBA/KlJms-lprcg/lprcg.

CBA/KlJms-lprcg/lprcg mice with a novel mutation producing systemic lymphoproliferation were investigated for their serological and histological characteristics. The mutant mice showed elevated levels of serum immunoglobulin, C1q-binding immune complexes and antibodies to nuclear antigens such as dsDNA and ssDNA and poly(ADP-ribose). In contrast, histopathological lesions, e.g. glomerulonephritis, vasculitis or interstitial pneumonitis, were not revealed by histological and immunofluorescent examinations, except for lymphocytic infiltration in various organs. These results suggest that this mutant mouse strain may provide a new animal model for autoimmunity. However, further investigations are required to clarify whether this strain is unique as compared with other well-known lupus-prone strains of mice with respect to serological and histological abnormalities and become to be a new model of systemic autoimmune disease.

Animals↗
PubMed1990

Distribution of arterial lesions and collateral pathways in the pulmonary hypertension of congenital heart disease: a computer aided reconstruction study.

Three dimensional computer aided reconstructions of pulmonary vessels were used to investigate the distribution of vascular changes and the formation of collateral channels in 11 patients with congenital heart disease. In the patients with less severe grades of hypertensive pulmonary vascular disease obstructive changes were unevenly distributed, whereas in those with disease of grade 4 or more distribution became more even. Plexiform lesions occurred rather more frequently in supernumerary arteries arising laterally from a large parent vessel, whereas cellular or fibrous intimal thickening tended to affect dichotomous branches at the periphery. Hypertensive changes were confined to arteries of 100-150 microns diameter running along the necks of acini. Various types of collateral channels were found. In particular, the reconstructions suggest that pulmonary arterial blood at high pressure could flow into bronchial arteries via proximal bronchopulmonary arterial anastomoses, and thence by way of dilatation lesions to the alveolar capillaries.

Adult↗
PubMed1990

Aortic regurgitation: ventricular response after aortic valve replacement.

This study was designed to evaluate the usefulness of the ratio of the preoperative regurgitant stroke volume to left ventricular end-diastolic volume (RSV/LVEDV) for assessing the left ventricular function preoperatively. In 26 patients with aortic regurgitation (AR), the percent decrease in LVEDV was compared with the preoperative RSV/LVEDV, ejection fraction (EF), LVEDV, left ventricular end-systolic volume (LVESV) or left ventricular end-diastolic pressure (LVEDP). There was a significant correlation between the percent decrease in LVEDV and RSV/LVEDV. Patients with RSV/LVEDV of more than 0.26 had a significantly smaller postoperative left ventricular end-diastolic volume index (LVEDVI) and left ventricular end-systolic volume index (LVESVI), and a greater postoperative EF than patients with smaller RSV/LVEDV. All but one patient with RSI/LVEDVI larger than 0.0016 LVEDVI had normal postoperative LVEDVI. Based on these findings, it is concluded that the RSV/LVEDV is an useful indicator for preoperative evaluation of left ventricular functions in patients with AR. Surgical intervention for patients with AR should be recommended before the RSI/LVEDVI drops to less than 0.0016 LVEDVI, to expect good postoperative ventricular responses.

Adult↗