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K Saida

Publications and source records attributed to K Saida.

At least 55 records · Page 3Linked to original sources
PubMed1993

[New trends in studying the regulatory mechanism of smooth muscle contraction].

In this paper, we briefly review current topics about smooth muscle with regards to Ca2+ release, Ca2+ sensitization, and Ca2+ regulation of contraction. Inositol 1,4,5-trisphosphate releases Ca2+ from the sarcoplasmic reticulum, where Ca(2+)-dependent immediate feedback control may work. However, the involvement of this feedback control in the Ca(2+)-induced Ca2+ release mechanism remains to be elucidated. Either agonist or GTP gamma S is known to increase the Ca2+ sensitivity of myofilaments. The agonist-induced Ca2+ sensitization could be explained by the up-regulation due to myosin light chain kinase or by the down-regulation due to myosin light chain phosphatase. The GTP gamma S-induced Ca2+ sensitization seems to be mediated by rho A p21, a small G protein. Thus, myosin phosphorylation is not the obligatory way to regulate the actin-myosin interaction. We propose that cross-linking between actin and myosin may work as an alternative way to regulate the interaction from biochemical studies. The candidates for the cross-linkers are caldesmon, calponin and myosin light chain kinase. The inhibitory effect of Ca2+ on the interaction, which is observed under the specific conditions for measuring smooth muscle contraction, may hold the key to finding the physiological significance of the cross-linking activity.

Actins↗
PubMed1993

Improvement of ischemic myocardial dysfunction by nisoldipine in relation to its coronary vasodilating action.

We examined the cardioprotective effect of nisoldipine against myocardial dysfunction during ischemia and reperfusion in comparison with those of diltiazem and nifedipine in rabbit hearts perfused at constant pressure. These calcium antagonists were administered to the hearts before 60 min of ischemia. They inhibited the increase of end-diastolic pressure during ischemia in a dose-dependent manner. Diltiazem at 1.0 microM, nifedipine at 3.0 microM and nisoldipine at 0.01 microM produced the maximal cardioprotective effect. Nisoldipine had a beneficial effect with less negative inotropic effect than those of diltiazem and nifedipine and it produced a significant increase of coronary flow during reperfusion. When the vascular component was eliminated under constant flow perfusion, nisoldipine also showed the cardioprotective effect. Nisoldipine did not produce any beneficial effect without the inhibition of the increase in end-diastolic pressure during ischemia nor did it do so without the increase of reperfusion flow. Therefore, the nisoldipine-increased coronary flow during reperfusion as well as the inhibition of ischemic contracture by nisoldipine seems to play a crucial role in improving the myocardial dysfunction of ischemic-reperfused hearts.

Animals↗
PubMed1993

[Manifesting carriers of Duchenne muscular dystrophy over two generations].

We report a family with manifesting DMD carriers over two generations. Sixty years old female (case 1) suffered from slowly progressive weakness since her thirties. Her youngest daughter aged 30 (case 2) had cramping calf muscle pain since her 5 years old. Progressive muscle weakness developed and lost her ambulation by the age of 20. Grandson of case 1 (son of case 1's eldest daughter who has no clinical symptoms) was diagnosed as DMD with deletion of exon 19-21 in dystrophin gene. Case 1 and case 2 were revealed to be DMD carriers. We speculate that, in this family, X-inactivation process was not random and paternal X was preferentially inactivated by maternal mutant X.

Adult↗
PubMed1993

[Influence of posture changes on hemodynamics under fentanyl-diazepam anesthesia--effects of nitrous oxide].

Patients for myocardial revascularization were divided into 50% oxygen-50% nitrogen group (group A) and 50% oxygen-50% nitrous oxide group (group B) according to the kind of gas administered after the induction of anesthesia. Anesthetic induction was carried out with fentanyl and diazepam in both groups. With sufficient hemodynamic stabilization following the induction of anesthesia, the hemodynamic parameters were measured in supine position for baseline data (BASELINE). The operating table was kept at Trendelenburg position (TREND), i.e., head down position, to measure hemodynamic parameters. Next, the operating table was kept at Fowler position (FOW), i.e., head up position, and hemodynamic parameters were measured. Heart rate was little influenced by posture change in both groups. While mean arterial pressure, mean pulmonary arterial pressure, central venous pressure and pulmonary capillary wedge pressure increased significantly in TREND in both groups, and decreased significantly in FOW. Cardiac index increased significantly in TREND in group A, but no such change occurred in group B. In FOW, cardiac index showed no significant change in group A, but decreased significantly in group B. Systemic vascular resistance was little influenced by posture change in both groups. This study suggests that it is necessary to exert a great caution in administering nitrous oxide when posture change is needed under fentanyl-diazepam anesthesia.

Anesthesia↗
PubMed1992

Involvement of rho p21 in the GTP-enhanced calcium ion sensitivity of smooth muscle contraction.

In the rabbit mesenteric arterial smooth muscle skinned by saponin, Ca2+ induced contraction in a concentration-dependent manner. Guanosine 5'-(3-O-thio)triphosphate (GTP gamma S), a non-hydrolyzable GTP analogue, lowered the Ca2+ concentrations required for this contraction and increased the Ca2+ sensitivity of the skinned smooth muscle contraction. GTP gamma S alone did not induce the contraction in the absence of Ca2+. This GTP gamma S-enhanced Ca2+ sensitivity was completely abolished by an exoenzyme of Staphylococcus aureus, named EDIN, and an exoenzyme of Clostridium botulinum, named C3, both of which are known to ADP-ribosylate the rho p21 family that belongs to the ras p21-like small GTP-binding protein superfamily. The GTP gamma S-bound form of rhoA p21 overcame the inhibitory action of EDIN. smg p21B, another small GTP-binding protein, was inactive. EDIN ADP-ribosylated a protein, which was most likely to be rho p21, in the skinned smooth muscle. The GTP gamma S-bound form of rhoA p21, but not the GDP-bound form, substituted for GTP gamma S and enhanced the Ca2+ sensitivity of the skinned smooth muscle contraction. smg p21B was inactive. These results indicate that rhoA p21 is involved in the GTP gamma S-enhanced Ca2+ sensitivity of the smooth muscle contraction.

Adenosine Diphosphate Ribose↗
PubMed1991

cDNA cloning, sequence analysis and tissue distribution of a precursor for vasoactive intestinal contractor (VIC).

A full-length cDNA encoding preprovasoactive intestinal contractor (PPVIC) has been cloned. From the deduced 160 amino acid PPVIC, the mature VIC is predicted to be produced via a 37 residue intermediate, big VIC. The PPVIC also contains a VIC-like peptide of 16 amino acids structurally related to to the amino-terminal residues of VIC and flanked by pairs of dibasic amino acids, putative processing sites. RNA blot hybridization with PPVIC cDNA confirmed the PPVIC gene to be expressed in the small and large intestinal tract in a tissue specific manner.

Amino Acid Sequence↗
PubMed1991

Structure of the precursor for vasoactive intestinal contractor (VIC): its comparison with those of endothelin-1 and endothelin-3.

Vasoactive intestinal contractor (VIC) is a member of the endothelin (ET) peptide family, which evokes a strong contractile response in the ileum, its gene being expressed only in the intestine. Using dot blot analysis, we carried out an interspecies comparison of the nucleotide and deduced amino acid sequences of the precursor for VIC with those of ET-1 and ET-3 to investigate the physiological significance of processing of the precursor for VIC. The highly conserved amino acid sequence was observed between the big form region (big VIC, big ET-1, and big ET-3) of about 40 amino acids and the like peptide region (VIC-like peptide, ET-1-like peptide, and ET-3-like peptide) of 15 amino acids downstream from the big form region. Sequence identity of amino acids of the precursors of ET-1 and ET-3 with that of VIC was 29 and 28%, respectively. Thus, the precursors for the three peptides might have arisen from a common progenitor gene. However, apparent cleavage sites of the like peptide regions are rather unique in the VIC-like peptide, i.e., it had dibasic amino acids at the amino and carboxy termini. Therefore, we suggest that the VIC-like peptide might be liberated from its precursor protein and play some role in the intestine in vivo.

Amino Acid Sequence↗
PubMed1991

Non-Menkes-type copper deficiency with regression, lactic acidosis, and granulocytopenia.

A 2-year-old girl with granulocytopenia developed fever followed by truncal ataxia and progressive neurologic regression. CT demonstrated symmetric low-density areas in the cerebral white matter. Sural nerve biopsy revealed axonal degeneration. Blood lactate levels were high, and serum levels of copper and ceruloplasmin and urinary excretion of copper were low. Cultured skin fibroblasts showed normal copper uptake. Treatment with oral copper administration normalized serum copper and ceruloplasmin levels, blood lactate levels, and granulocyte count. However, copper levels in the CSF were still low, and the patient showed no clinical improvement. We speculated that copper transport across the intestinal wall and across the blood-brain barrier was impaired.

Acidosis, Lactic↗
PubMed1991

Establishment of vascular endothelial cell lines in a serum-free culture and the discovery of endothelin and a vasoactive intestinal contractor (VIC).

Immortal vascular endothelial cell lines were established and utilized for the production of an endothelium-derived contraction factor (EDCF) in a serum-free medium. After the discovery of Endothelin (21 amino acid peptide, ET) as an EDCF, a prepro ET cDNA isolated from human tissue was used to examine the expression of ET and its regulation in human endothelial cells. A gene family of ET was shown in mouse by using prepro ET cDNA as a probe. Thus, a novel peptide, Vasoactive Intestinal Contractor (VIC) homologous to ET was deduced from the sequence of one of these genes. VIC was confirmed to induce vasocontraction as well as intestinal contraction. Northern blot analysis indicated that this gene was expressed in the intestine but not in endothelial cells. A cloning and sequencing of prepro VIC cDNA from mouse intestine suggest that a VIC-like peptide, as well as VIC, are co-synthesized by cleavage from prepro VIC with 160 amino acids.

Amino Acid Sequence↗
PubMed1991

[Two brother cases of late-onset familial amyloidotic polyneuropathy in Kyoto].

Measurement of variant Met30 transthyretin is diagnostic for a patients with familial amyloidotic polyneuropathy (FAP) type I. The elder brother first noticed numbness of the feet at 64 years of age, and developed weakness of the legs. A few years later, he noticed numbness of the hands, and he was admitted to the hospital at 67 years of age. He was emaciated and had hoarseness and macroglossia. He had moderate muscle atrophy and weakness of all extremities with distal predominance. Deep tendon reflexes were hypoactive in the upper limbs and absent in the lower limbs. There was marked sensory loss of pain and temperature in all 4 limbs distally, and position sense was also impaired. He had mild orthostatic hypotension, severe cardiomegaly and arrhythmia. The younger brother noticed cold sensation of the feet and sexual impotence at 59 years of age. Two years later, he had numbness of the feet and developed weakness of the legs. At 65 years of age, he was admitted to the hospital because of the micturition syncope. He was emaciated and had macroglossia. He had moderate muscle atrophy and weakness of all extremities with distal predominance. Deep tendon reflexes were absent. There was marked sensory loss in the extremities which was predominant in pain and temperature. He had severe orthostatic hypotension (112/70 mmHg in supine position, 50/30 mmHg on standing). Plasma NE value was low and showed poor response to standing. He had neither cardiomegaly nor arrhythmia. Their parents were supposed to have no neurological symptom and were not related with any other Japanese foci of FAP.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

[Mitral valve replacement in idiopathic hypereosinophilic syndrome].

Idiopathic hypereosinophilic syndrome (IHES) is a rare systemic manifestation of eosinophilia that may cause endocardial fibrosis and thrombus formation. We presented a 48-year-old man with rapid onset of intractable congestive heart failure during the course of chemotherapy for IHES. After the urgent operation, which included left ventricular thrombectomy and mitral valve replacement the patient was asymptomatic, but died 1 month after operation because of development of IHES. Atrioventricular valve replacement may be beneficial to selected patients with congestive heart failure associated with the cardiac process of the IHES and review of the literature led us to prefer porcine heterograft prostheses in patients with IHES.

Eosinophilia↗
PubMed1991

[Evaluation of treatment of lung cancer combined with the disease which has needed a semi-emergency operation].

Six cases of lung cancer combined with the disease which has needed semi-emergency operation, two cases of unstable angina, two of ileus due to colon cancer, one of impending rupture of abdominal aortic aneurysm and one of purulent cholecystitis with cholelithiasis, were discussed. Mean age was 62.0 years (range, 36 to 73); four were male and two were female. Case 1 and 2 were admitted with anterior chest pain, Case 3 with lumbago and abdominal pain, Case 4 and 5 with an abnormal shadow on chest x-ray film and Case 6 with abdominal pain. Of the two with unstable angina, one was operated on with right upper lobectomy during the first months after aorto-coronary bypass. Of the two with colon cancer, one was operated on with right upper lobectomy during about 5 weeks after right hemi-colectomy. Case 3 with abdominal aortic aneurysm operated on with left upper lobectomy during 4 weeks after replacement of abdominal aorta. Case 4 with cholecystitis was operated on with left pneumonectomy during about 3 weeks after cholecystectomy. The postoperative course of 4 cases and the post-chemotherapy condition of 2 cases were uneventful.

Adenocarcinoma↗
PubMed1991

[Combined valvular and coronary artery surgery].

We report 14 consecutive patients who have undergone myocardial revascularization combined with valve surgery during 7 years (1983-1989). There were 7 males and 7 females with a mean age of 53.8 years. All patients had congestive heart failure and 7 had angina pectoris. Coronary angiography revealed single-vessel disease in 6 patients, double-vessel disease in 5, triple-vessel disease in 3. Mitral regurgitation was predominant in 5, aortic regurgitation in 5, mitral stenosis in 3 and aortic stenosis in 1. The indicated operations were: valve replacement in 12 and mitral anuloplasty in 2 with coronary artery bypass grafting (mean 1.6). One operative and 1 late death were seen in our series, however, NYHA functional class was improved from 3.4 to 1.7 postoperative. Postoperative evaluation by UCG showed good recovery of cardiac function (EF, MVcf, LVEDV, CI). No angina pectoris was evident in surviving patients, the quality of life was significantly improved.

Aged↗
PubMed1991

[A case of esophageal duplication cyst associated with a total left pericardial defect].

Esophageal duplication cyst associated with pericardial defect in a 57-year-old man is reported. Differential diagnosis was very difficult in the preoperative examination. The tumor was a cyst and its wall was a perfect replica of normal esophagus e.g. esophageal duplication, and total left pericardial defect also was found at the operation. There was no malignant or inflammation findings in the excised specimens. The association of esophageal duplication cyst associated with pericardial defect is very rare.

Esophageal Cyst↗
PubMed1990

[Effector mechanisms of PNS demyelination in Gal-C induced-EAN].

Myelin in PNS is multi-layered membranes formed by Schwann cells, and surrounds axon. Destruction of myelin sheath results in demyelination and disturbance of nerve conduction. In PNS, Charcot-Marie-Tooth disease, certain lipidoses, Guillain-Barré syndrome, lead poisoning, compression and some metabolic neuropathies can produce demyelination. In these diseases, GBS is thought to be resulted from abnormalities of immune mechanism. Recently, autoantibodies against Gal-C, P2 and GM1, and complement fixing antibodies against PNS myelin are found in some of GBS patient sera. Here, I present studies on effector mechanism of PNS demyelination using models produced by application of Galactocerebroside (Gal-C) antibodies to PNS. Mainly, three types of effector mechanisms are involved in Gal-C antibody-induced demyelination. In abundance of antibodies, complement-mediated demyelination is at work. When complements are absent, antibody dependent macrophage-mediated demyelination can be involved. Thirdly, myelin once damaged by oxidants and etc can be opsonized by antibodies and C3b, and phagocytized by macrophages. These processes may be operating in such diseases like GBS and CIDP.

Animals↗
PubMed1990

[A case of polymyositis associated with chronic active hepatitis].

A case of polymyositis associated with chronic active hepatitis was reported. A 53-year-old man, who had no previous history of blood transfusion nor hepatitis, noticed proximal dominant muscle weakness on January 29, 1985. He was admitted to Kyoto National Hospital on February 7, and laboratory studies disclosed the elevation of serum enzyme levels; creatine kinase (CK) 9845 IU/L (normal 54-263), glutamate oxaloacetate transaminase (GOT) 834 IU/L (9-31), glutamate pyruvate transaminase (GPT) 491 IU/L (4-34), lactate dehydrogenase (LDH) 2135 IU/L (248-464). Also serum gamma globulin was high (1.8 g/dl) and LE-like cell was found. The diagnosis of polymyositis was made and prednisolone therapy (60 mg/day) was started on February 23. The elevated serum enzymes decreased gradually, but severe muscle weakness persisted for about one month. On April 3, he was admitted to our hospital. Physical examination revealed moderate proximal dominant muscle weakness without skin eruption, jaundice or hepatosplenomegaly. The serum enzymes were still high; CK 1826, GOT 173, GPT 232 (GOT less than GPT), LDH 1548. However, alkaline phosphatase (ALP) and bilirubin were normal. Hepatitis B surface antigen (HBsAg) was not detected. Antinuclear antibody was positive. The electromyogram study showed myopathic change, and the muscle biopsy demonstrated myopathic change and cell infiltration, compatible with polymyositis. These results suggested liver dysfunction associated with polymyositis. Prednisolone therapy was continued and muscle weakness decreased. From December, 1985, serum enzymes (CK, GOT, GPT, LDH) elevated again and muscle weakness also slightly increased. Anti-smooth muscle antibody was positive. It was suggested that both polymyositis and liver dysfunction deteriorated.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoantibodies↗
PubMed1990

Binding activity and autophosphorylation of the insulin receptor from patients with myotonic dystrophy.

To clarify a mechanism of insulin resistance associated with myotonic dystrophy, we studied the insulin receptor by using three different types of cells--circulating erythrocytes, cultured skin fibroblasts, and Epstein-Barr virus(EBV)-transformed lymphocytes. In myotonic dystrophy, insulin binding to erythrocytes and fibroblasts was significantly decreased as a result of a reduction of the binding affinity. Insulin binding to EBV-transformed lymphocytes was normal. When the receptors were purified from fibroblasts with wheat germ agglutinin, we could not find a decrease in the binding affinity seen in the intact cells. No difference was observed in the magnitude of basal and insulin-stimulated autophosphorylation of insulin receptors from EBV-transformed lymphocytes between the control and myotonic dystrophy. Southern blot analysis of the insulin receptor gene revealed no restriction fragment length polymorphism associated with myotonic dystrophy. These findings suggest that there is no primary defect of the insulin receptor per se in terms of insulin binding and autophosphorylation in myotonic dystrophy. The reduction of the insulin binding to erythrocytes and fibroblasts may be caused by the plasma membrane abnormality that affects the binding affinity of the receptor.

Adult↗