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Biomedical subjects

H Mohri

Publications and source records attributed to H Mohri.

At least 217 records · Page 12Linked to original sources
PubMed1989

Anthraniloyl ATP, a fluorescent analog of ATP, as a substrate for dynein ATPase and flagellar motility.

We synthesized an anthraniloyl ATP (ant-ATP), which has a fluorescent anthraniloyl moiety at the OH group of ribose, to elucidate the mechanism of flagellar bend formation and its propagation in relation to the mechanochemical cycle of dynein ATPase. This fluorescent analog of ATP was efficiently hydrolyzed by 21 S dynein from sea urchin sperm flagella with Km = 7.6 microM, whereas the Km was 12 microM when ATP was used as the substrate. Similar Vmax values were obtained with both ATP and ant-ATP. Inhibition of the hydrolysis of ant-ATP by vanadate was a little smaller than that with ATP. Photosensitized cleavage of 21 S dynein heavy chains in the presence of ant-ATP and vanadate was also a little less efficient than that in the presence of ATP and vanadate. Ant-ATP also induced the disintegration of the trypsin-treated axoneme and the motility of demembranated sperm in a manner similar to ATP. When ATP was used as a substrate for the demembranated sperm, the apparent Michaelis constant for beat frequency (Km f) was 0.22 mM and the maximum frequency (fmax) was 36 Hz, whereas Km f) was 0.14 mM and fmax was 20 Hz for ant-ATP. Thus ant-ATP could be an efficient fluorescent analog of ATP for studying dynein ATPase and the mechanisms of flagellar motility.

Adenosine Triphosphatases↗
PubMed1989

Two states of the conformation of 21S outer arm dynein coupled with ATP hydrolysis.

Tryptic digestion of 21S outer arm dynein from sea urchin sperm flagella in the presence of ATP (or ADP) and vanadate produced quite different polypeptides from those obtained in the absence of ATP (ADP) and/or vanadate (Inaba and Mohri (1989) J. Biol. Chem. 264, 8384-8388). The 21S dynein heavy chains were consistently digested into 165- and 135-kDa polypeptides in the absence of both ATP (ADP) and vanadate. In the presence of 2 mM ADP and 100 microM vanadate, 300-kDa polypeptide, which appeared to be a precursor of 165- and 135-kDa polypeptides, became less accessible to trypsin, and 165- and 135-kDa polypeptides were digested into 150-/148-kDa and 96-kDa polypeptides, respectively. Quantitative analysis of the degradation of 165- and 135-kDa polypeptides showed that the conformations of these polypeptides change remarkably in the presence of ATP (ADP) and vanadate, and slightly in the presence of ATP gamma S. Photoaffinity labeling with 8-azidoadenosine 5'-triphosphate and vanadate-mediated photocleavage of dynein heavy chains revealed that both adenine- and gamma-Pi-binding sites were located on 165- and 150-/148-kDa polypeptides, but not on 135-kDa polypeptide. These results suggest that the conformational change occurring in the 165-kDa region on binding ATP spreads to the 135-kDa region and causes the conformational change of the 135-kDa region.

Adenine↗
PubMed1989

[An arginine esterase in the human sperm].

Human sperm was highly purified by the use of a discontinuous Percoll density gradient placed in an innercolumn of a centrifugation tube. Seminal plasma contamination was only 0.0008 percent in the purified sperm. A new basic arginine ester hydrolyzing enzyme with a weak affinity for lima bean trypsin inhibitor (LBTI) Cellulofine column was found in the purified human sperm, and the characteristics of this enzyme were found to be different from those of human acrosin.

Calcium Chloride↗
PubMed1989

Indications for surgery based on lung biopsy in cases of ventricular septal defect and/or patent ductus arteriosus with severe pulmonary hypertension.

Pathologic obstruction of the proximal lumen and secondary atrophy of the media of the peripheral small pulmonary arteries were absolute operative contraindications in cases of VSD and/or PDA with severe pulmonary hypertension. Such patients who were operated on died with no decrease in pulmonary arterial pressure. The index of pulmonary vascular disease (IPVD), a composite and quantitative evaluation of the severity of pulmonary vascular disease, was introduced to determine the operability of other patients. An IPVD rating of 2.2 in Down's syndrome and 2.1 without the syndrome were regarded as the upper permissible limits for surgical intervention based on results of 23 autopsies and 26 lung biopsies of patients operated on before 1981. Open lung biopsy was performed in 51 patients to determine applicability of our operative indications. Twenty-nine cases were considered operable by our criteria, and 28 underwent surgical correction without operative or late death. Twenty-two cases thought inoperable remain under observation. Comparative analysis of the pathology and preoperative hemodynamic data suggested that lung biopsy should be carried out to determine operability in cases with pulmonary vascular resistance greater than 8 units.m2.

Biopsy↗
PubMed1989

[Growth of tracheal anastomoses in growing animals].

Growth of the trachea after complete transection and anastomoses was studied in four equal groups (N = 7) of young New Zealand white rabbits (mean weight 1.19 +/- 0.19 kg). The trachea was transected below the 5th cartilagenous ring and immediately anastomosed. Suture materials and sewing techniques used for comparison were continuous 6-0 polypropylene, interrupted 6-0 polypropylene, continuous 6-0 polydioxanone (PDS) or interrupted 6-0 PDS. The animals were electively sacrificed between 95 and 98 days after surgery. Mean body weight increased to 2.7 +/- 0.18 kg. Mean cross sectional area (CSA) of the trachea at sacrifice at the anastomosis (A) and an average of CSA 5 mm above and below the anastomosis (B) were compared. The ratios (A/B) of each groups were 0.52 (continuous polypropylene), 0.62 (interrupted polypropylene), 0.58 (continuous PDS) and 0.80 (interrupted PDS), respectively. One way of analysis of variance revealed that growth of the tracheal anastomoses in interrupted PDS was significantly better (p less than 0.005) than other combinations. It was concluded that growth of the trachea following complete transection and anastomosis in a growing animal was significantly better with absorbable suture material and interrupted suturing technique.

Anastomosis, Surgical↗
PubMed1989

[Emergent surgical management of aortic dissecting aneurysm, type A Stanford, complicated with acute cardiac tamponade; report of a case].

A 52-year-old woman, who had been treated medically for 31 days with the diagnosis of type A aortic dissection, suddenly fell in shock because of acute cardiac tamponade. Emergent operation was performed two hours after the onset of shock. Entry and perforation were located in the ascending aorta. Ascending aorta was opened without cross-clamping under profound hypothermic low flow perfusion through femoral artery, and intraluminal grafting with a double ringed graft was completed. Combined technique of open distal anastomosis and ringed graft is useful in such an emergent case as cardiac tamponade of aortic dissection.

Aortic Dissection↗
PubMed1989

[Pulmonary vascular disease in shunted and nonshunted patients with tetralogy of Fallot].

Histometric analysis of pulmonary vascular disease was performed in 21 nonshunted patients and in 13 shunted patients with tetralogy of Fallot and in 29 normal controls. There was no significant difference in the medial thickness of the small pulmonary arteries between cases of tetralogy of Fallot and normal controls. However, the media in the shunted cases of tetralogy of Fallot gave the impression of being thicker than these in the nonshunted cases. Intimal fibrosis, regarded as organized thrombi, and thrombi of small pulmonary arteries were observed generally after 4 years of age in shunted and nonshunted cases of tetralogy of Fallot. Intimal proliferation of musculoelastosis which was formed longitudinal smooth muscle bundles and elastic fibers was characteristic in shunted patients, especially after the central palliation procedure, Waterston anastomosis and modified Blalock-Taussig (B-T) anastomosis using a Gore-Tex tube graft. However, musculoelastosis was not usually seen in the B-T anastomosis cases. Unexpected pulmonary hypertension due to shunt operation is thought to be the cause of musculoelastosis, because musculoelastosis was observed even in a patient with pulmonary hypertension 3 weeks following surgery. We, therefore, recommend original B-T anastomosis as the shunt procedure. When considering use of the other shunt operations which entail pressure load on the pulmonary vascular bed, attention must be given to the size of the anastomosis or artificial tube graft.

Adolescent↗
PubMed1989

[Surgical treatment of tricuspid regurgitation].

The purpose of this study is to compare early and late results of tricuspid valve replacement (TVR), tricuspid annuloplasty (TAP) and non operative management for patients with tricuspid regurgitation (TR). 5 patients underwent TVR and 70 patients received TAP (Kay-Boyd's annuloplasty in 16, Bex reducer method in 40, Carpentier's ring method in 14). 21 patients were managed non-operatively. The following results were obtained. TR should be repaired aggressively, if the regurgitation was more than second degree and tricuspid annulus was above three finger breadth. Judging from the pattern of residual TR after Kay-Boyd's annuloplasty and Bex reducer method, Bex reducer and Carpentier's ring should be placed over the three commissures except the conduction tract.

Heart Valve Prosthesis↗
PubMed1989

[Clinical experience of autotransfusion system (ATS)--changes in free hemoglobin and haptoglobin].

This study was done to evaluate the usefulness of ATS and the administration of haptoglobin, and is comprised of 15 patients following open heart surgery. Shed mediastinal blood was retransfused during 4-6 hours after open heart surgery. Plasma free Hb (F-Hb) value of the shed blood was 647 mg/dl. But plasma F-Hb of patient did not significantly increase after retransfusion of shed blood without administration of haptoglobin. Plasma F-Hb of patient decreased significantly from 12 mg/dl to 3.3 mg/dl when haptoglobin was given. (p less than 0.05). There was no serious complication associated with the use of ATS, and could save 300 ml of homologous blood. It is concluded that ATS can be used safely for saving homologous blood after open heart surgery and haptoglobin is effective for decreasing of plasma F-Hb.

Blood Transfusion, Autologous↗
PubMed1989

[Open-heart surgery in a patient with chronic leukemia].

A 66-year-old woman with severe congestive heart failure, leucocytosis and recent cerebral thrombosis, was admitted to our hospital. Examination of her heart revealed mitral steno-insufficiency, tricuspid regurgitation and left atrial thrombi. The hematological study confirmed the diagnosis of chronic neutrophilic leukemia (CNL). Administration of carbazilquinone (0.5-0.75mg/day) was quite effective to stabilize CNL. However, repeated episodes of cerebral thromboembolism, intractable heart failure and patient's desire pushed us to perform cardiac operation. Utilizing routine cardio-pulmonary bypass and moderate hypothermia, removal of left atrial thrombi, mitral valve replacement with a 27mm Björk-Shiley prosthesis and tricuspid annuloplasty with a 32mm Carpentier-Edwards prosthetic ring were performed. We had no difficulty in hemostasis at the operation. Her recovery was, contrary to all expectations, satisfactory without hemorrhagic diathesis, infection nor blastic crisis. Six months after operation, she is doing well and it is unnecessary to reinstitute chemotherapy for CNL. To our knowledge, this is the first case report of open-heart surgery in a leukemic patient in Japan.

Aged↗
PubMed1989

[Unilateral pulmonary venous obstruction: a case report].

A 3-month-old girl with right common pulmonary venous obstruction and severe pulmonary hypertension underwent pulmonary venous reconstruction (venoplasty). However, pulmonary hypertension persisted and she died on the 69th postoperative day. Autopsy revealed a widely opened pulmonary vein at the site of the venoplasty. Histological examination showed thickened alveolar walls, thromboembolism in pulmonary arterioles and venous hypoplasia in the right lung. The venoplasty for unilateral pulmonary venous obstruction with severe pulmonary hypertension may not be the proper treatment, since pulmonary hypertension usually continues or progresses postoperatively. Pneumonectomy may be a better choice to be applied.

Child, Preschool↗
PubMed1989

[A clinical study of the myocardial protective effect of allopurinol].

This study was proposed to study the myocardial protective effect of allopurinol clinically. This study involved 65 patients undergone coronary artery bypass operations or cardiac valve replacements or plasties. Patients were divided into two groups: group I, 30 patients received 2,400 mg of allopurinol preoperatively; group II, 35 patients undergoing no treatment of allopurinol. Postoperative values of GOT, CK-MB and LDH1 + LDH2 in group I were significantly lower than that of group II. These results suggest that allopurinol has advantageous effect on myocardial protection.

Adult↗
PubMed1989

[Effects of exocorpol and haptoglobin on hemolysis during ECC].

This study was performed to evaluate the effects of Exocorpol and Haptoglobin on hemolysis during ECC. We measured free hemoglobin (F-Hb) and free haptoglobin (F-Hp) at pre- and post-ECC. Patients were divided four groups: Group C, 5 patients undergoing no treatment; Group Ex, 5 patients undergoing treatment of Exocorpol; Group Hp, 5 patients undergoing treatment of Haptoglobin; Group Ex + Hp, 5 patients undergoing treatment of Exocorpol and Haptoglobin. F-Hb of pre- and post-ECC in four groups were 0 mg/dl: 85 mg/dl (Group C, p < 0.01), 0 mg/dl: 2 mg/dl (Group Ex, NS), 0 mg/dl: 1 mg/dl (Group Hp, NS), 0 mg/dl: 0 mg/dl (group Ex + Hp, NS). F-Hp of pre- and post-ECC in four groups were 143 mg/dl: 9 mg/dl (Group C, p < 0.02), 133 mg/dl: 25 mg/dl (Group Ex, p < 0.05), 186 mg/dl: 195 mg/dl (Group Hp, NS), 66 mg/dl: 163 mg/dl (Group EX + Hp, p < 0.05). There was no significant difference in F-Hb and F-Hp of pre-ECC among four groups. F-Hb of post-ECC in Group C was significantly higher than that of Group Ex, Hp and Ex + Hp (p < 0.01), and F-Hp of post-ECC in Group Hp and Ex + Hp was significantly higher than that of Group C and Ex.(p < 0.01, p < 0.02). We concluded that Exocorpol and Haptoglobin were effective on hemolysis during ECC, and combination of these was more effective.

Extracorporeal Circulation↗
PubMed1989

[Clinical effects of denopamine in patients with cardiac operations].

Denopamine is a new, orally active, positive inotropic agent. We evaluated its clinical effects in 13 patients who had undergone cardiac operations, 8 were in early postoperative periods and 5 were in late postoperative periods. In the former, denopamine therapy (30 mg/day) were started on the 6-14 th postoperative day in 5 patients so that they might free from catecholamine drip infusion (2-14 micrograms/kg/min), and on the 14-24th postoperative day in 3 patients in order that pleural effusion might reduce. All 5 patients were weaned from catecholamine, and pleural effusion in 3 patients disappeared completely. In the latter, denopamine therapy were indicated so that they might get relief from the symptoms of chronic heart failure. Although they had undergone combined valvular operations, they still remained in NYHA class II or III postoperatively, associated with cardiomegaly, hepatomegaly and atrial fibrillation. Denopamine therapy (15-30 mg/day) were quite effective in improving subjective symptoms but not in reducing cardiomegaly or hepatomegaly. No clinically significant side effects were noticed during 9-14 months of denopamine therapy. We conclude that denopamine is a quite useful cardiotonic agent in the postoperative management of patients with cardiac surgery.

Adult↗
PubMed1988

Structure of the von Willebrand factor domain interacting with glycoprotein Ib.

von Willebrand factor is a multifunctional adhesive protein of plasma, platelets, and endothelial cells that mediates a crucial interaction for normal hemostasis and thrombus formation by binding to platelet membrane glycoprotein Ib. We provide here evidence that this function involves two limited noncontiguous regions of the molecule, each contained within 15 amino acid residues, separated in the linear sequence by 205 residues, and maintained in close spatial proximity in the folded molecule by disulfide bonding. Definition of this chemical structure clarifies a fundamental mechanism of platelet adhesion to thrombogenic surfaces and sets the bases for obtaining synthetic replicas that may be used to modulate platelet function.

Amino Acid Sequence↗