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Biomedical subjects

A Shibata

Publications and source records attributed to A Shibata.

At least 433 records · Page 24Linked to original sources
PubMed1988

Fast functional assay of protein C in whole plasma using a snake venom activator: evaluation in patients with congenital and acquired protein C deficiencies.

Both anticoagulant and amidolytic activities of protein C (PC) were measured using a snake venom activator in 4 patients with hereditary PC deficiency, 37 with disseminated intravascular coagulation (DIC), and 30 under stabilized warfarin therapy. The results were compared with those obtained by an immunological assay (ELISA). PC levels measured by different functional and immunological assays were very close in patients with hereditary PC deficiency and DIC. In patients under stable oral anticoagulant therapy, there was no detectable difference between amidolytic activity and antigen levels of PC in each patient plasma, whereas a decrease in anticoagulant activity was much more pronounced. These results indicate that the present activity assays measure PC specifically, and that the snake venom activator is capable of activating both carboxylated and hypocarboxylated forms of PC, but only anticoagulant assay can evaluate the physiological PC function in vitamin K-deficient states.

Biological Assay↗
PubMed1988

Type IB von Willebrand's disease and pregnancy: comparison of analytical methods of von Willebrand factor for classification of von Willebrand's disease subtypes.

The clinical course and changes in von Willebrand factor (vWf), factor VIII and bleeding time during pregnancy are described in a patient with type IB von Willebrand's disease (vWD) in whom all vWf multimers were present in plasma with relatively reduced content of the high-molecular-weight multimers. At term, ristocetin cofactor was elevated to some extent (from the baseline value of 5 U/dl to 23 U/dl), but never normalized and below the level of vWf antigen (49 U/dl). Bleeding time remained prolonged. In addition, abnormal distribution in the multimer size of plasma vWf was never corrected. These findings contrast with favorable responses during pregnancy reported in type IA individuals. The patient was infused during labor with 400 ml of fresh frozen plasma, and blood loss was approximately 800 ml. Analytical techniques of vWf by crossed immunoelectrophoresis, gel filtration on Sepharose 2B and SDS-agarose gel electrophoresis for the classification of vWD subtypes were compared. Multimer analysis by SDS-agarose gel electrophoresis was needed for differentiation of type IB from type IIA vWD.

Adult↗
PubMed1988

A case-control study of past history of nasal diseases and maxillary sinus cancer in Hokkaido, Japan.

A case-control study of maxillary sinus cancer was performed in Hokkaido with 116 cases and 232 controls matched for sex, age (within 5 years), and residence (same health center region). Preliminary univariate analyses showed that a history of chronic sinusitis [relative risk (RR) = 3.1]; nasal polyps (RR = 5.7); an occupational history of being a carpenter, joiner, furniture maker, or other woodworker (RR = 2.9); and a history of current or past cigarette smoking (RR = 3.3) were statistically significant risk factors for men. No single item was a significant risk factor for women.

Adult↗
PubMed1988

Plasmin-alpha 2-plasmin inhibitor complex in plasma of patients with disseminated intravascular coagulation.

Plasmin-alpha 2-plasmin inhibitor (alpha 2PI) complex, an indicator of in vivo plasmin generation, was measured in the plasma of 48 patients with disseminated intravascular coagulation (DIC), by enzyme-linked immunosorbent assay (ELISA). Plasmin-alpha 2PI complex was markedly elevated to 7.9 +/- 4.26 mg/liter (mean +/- SD) in DIC at presentation, with normal values at less than 0.8 mg/liter. The concentration of plasmin-alpha 2PI complex changed in parallel with the course of DIC and decreased to 1.9 +/- 1.49 mg/liter (n = 28) in remission. Among various underlying disorders, DIC, in patients with acute promyelocytic leukemia, had the highest complex levels (mean 10.8 mg/liter), and septic patients had the lowest levels (mean 3.4 mg/liter). No significant correlation was found between FDP and plasmin-alpha 2PI complex. These results indicate that the quantitative assay of plasmin-alpha 2PI complex in plasma would be valuable in the assessment of hyperfibrinolysis in DIC.

Acute Disease↗
PubMed1988

Multimeric composition of plasma von Willebrand factor in chronic myeloproliferative disorders.

In chronic myeloproliferative disorders (CMPD) thrombohaemorrhagic complications occur occasionally in association with thrombocytosis. We studied the multimeric composition of plasma von Willebrand factor (vWf) in 15 patients with polycythaemia vera (PV), 12 with essential thrombocythaemia (ET) and eight with primary myelofibrosis (PMF). The relative content of large (multimer band greater than or equal to 11) multimers calculated by densitometer scan following SDS-agarose gel electrophoresis was 18.5 +/- 4.4% (mean +/- SD) in normal controls, 8.3 +/- 7.9% in PV, 8.1 +/- 4.6% in ET and 19.6 +/- 6.7% in PMF. The patients with PV and ET but not PMF had a significantly lower percentage of large multimers than normal controls (P less than 0.001). The relative content of large multimers was negatively correlated with WBC and platelet count (P less than 0.02 each) in PV. It was negatively correlated with platelet count (P less than 0.005) and was positively correlated with a ratio of ristocetin cofactor/vWf antigen (RCof/vWf:Ag) (P less than 0.01) in ET. These results indicate that acquired defects of vWf are quite common in PV and ET but not in PMF. In addition, some CMPD patients with high platelet counts completely lacked large multimers. The negative correlation of the relative content of large multimers with platelet count suggests that large multimers may be preferentially consumed during thrombocytosis or degraded by protease(s) from increased blood cells.

Aged↗
PubMed1988

Syncope in aortic stenosis during continuous electrocardiographic monitoring--a case report.

A female patient with severe aortic stenosis had suffered from repeated syncope. Transaortic valve pressure gradient at cardiac catheterization was 117 mmHg. Continuous electrocardiographic monitoring was done after admission. During syncope, the electrocardiogram showed bradycardia with the lowest heart rate 44 beats per minute, while arterial pulses were not palpable. Rather than arrhythmia, other mechanisms, such as an inhibitory reflex from left ventricular receptors, should be postulated as the cause of syncope in patients with severe aortic stenosis.

Aged↗
PubMed1988

Danger of use of disopyramide in patients with hypertrophic obstructive cardiomyopathy. An electrophysiologic study.

A 61-year-old man with hypertrophic obstructive cardiomyopathy with asymptomatic ventricular tachycardia underwent electrophysiologic study. Double extrastimuli at the right ventricular outflow tract induced polymorphic ventricular tachycardia which degenerated into fibrillation. After intravenous administration of 50 mg of disopyramide, the pressure gradient in the outflow tract disappeared, but the tachycardia inducing zone appeared at the right ventricular apex. Although disopyramide may be used in patients with hypertrophic cardiomyopathy to relieve the intraventricular pressure gradient, it should be used only after evaluating its safety and efficacy electrophysiologically.

Cardiac Pacing, Artificial↗
PubMed1988

Acute and chronic effects of xamoterol in idiopathic dilated cardiomyopathy.

Xamoterol, a beta 1-partial agonist, was given to 10 patients with idiopathic dilated cardiomyopathy in NYHA functional classes II and III. The acute and chronic effects of xamoterol were assessed by changes in effort tolerance measured by multistage bicycle ergometry, echocardiography, radionuclide ventriculography and right heart catheterization. The acute effect was determined after a single intravenous injection of 0.2 mg/kg of xamoterol. Exercise heart rate decreased from 117 +/- 10 (mean +/- 1 SD) to 97 +/- 19 beats/min (p less than 0.01), but blood pressure and cardiac index were unaffected. When the drug was given orally at 200 mg/day for 3 months, exercise duration increased from 4.2 +/- 2.3 to 6.4 +/- 2.4 min (p less than 0.01), echocardiographic ventricular ejection fraction from 29 +/- 12 to 33 +/- 14% (NS) and radionuclide left ventricular ejection fraction from 37 +/- 11 to 45 +/- 14% (p less than 0.01), while pulmonary wedge pressure during exercise decreased from 40 +/- 10 to 31 +/- 10 mmHg (p less than 0.01). It may be concluded that xamoterol, by its action as a partial agonist, demonstrated both beta-agonist and antagonist effects in patients with idiopathic dilated cardiomyopathy. It thereby had beneficial effects on left ventricular function with resultant improvements in effort tolerance and subjective symptoms during long term treatment.

Adult↗
PubMed1988

Electrophysiologic study of patients with ventricular dysrhythmias during long-term follow-up after repair of tetralogy of Fallot.

We performed an electrophysiologic study (EPS) in 8 patients who had received corrective surgery for tetralogy of Fallot. The mean age was 30 years. An average of 15 years had elapsed after corrective surgery. Two patients had episodes of syncope. ECG showed normal sinus rhythm in 7 patients and atrial fibrillation in 1, and all had complete right bundle branch block. All patients had ventricular premature beats of grade 3 or higher of Lown's classification. Overdrive suppression test was performed in 6 patients. Corrected sinus node recovery time (CSNRT) ranged from 230 msec to 510 msec. Wenckebach block of atrioventricular nodal conduction occurred at rates of 130 to 170 bpm during atrial pacing. The H-V interval was prolonged to 60 msec in 1 patient, but was below 55 msec in the others. Programmed stimulation induced ventricular tachycardia (VT) in 3 patients, nonsustained VT in 2 and sustained VT in 1. In 2 of 3 patients, delayed potential or fragmentations were recorded in the outflow tract of the right ventricle. During the follow-up period of 20 months, 2 patients died suddenly. Their CSNRTs and H-V intervals were normal. Ventricular tachyarrhythmia seems to be important as a cause of late sudden death after repair of tetralogy of Fallot.

Adolescent↗
PubMed1988

AV nodal reentrant tachycardia with a bystander Mahaim fiber.

A 13 year old boy had a wide QRS complex tachycardia. A discontinuity in the AV nodal functional curve was observed in the electrophysiologic study. The AV internal was prolonged in association with progressive ventricular preexcitation. At maximal preexcitation, the HV interval was -20 msec and the QRS complex was identical to that seen during clinical tachycardia. No VA conduction was found and atrial premature beats did not affect the tachycardia. The His deflection was found at variable timing when tachycardia was induced. These findings confirmed that tachycardia originated within the AV node and was conducted to the ventricle over the Mahaim fiber. The short effective period of the Mahaim fiber had clinical significance since when atrial fibrillation developed, a rapid ventricular response was observed.

Adolescent↗
PubMed1988

Residual beta-cell function and metabolic stability in insulin-dependent diabetes mellitus.

Using the modified sensitive method of measurement of urinary C-peptide immunoreactivity (CPR) excretion, we studied whether positive correlation between residual beta-cell function and metabolic consequence is present in insulin-dependent diabetes mellitus (IDDM) or not. After urinary CPR excretions were measured for 3 days in 40 IDDM, they were divided to three groups: group A, urinary CPR excretion less than 1 microgram/day (n = 16); group B, 1-4 micrograms/day (n = 15); group C, greater than or equal to 4 micrograms/day (n = 9). All subjects were treated with intensive insulin therapy for 1-2 months, and 1) fasting blood glucose (FBS) for one week, 2) 24-hr urinary sugar excretion (US) for one week, 3) M-value for daily variation of blood glucose, and 4) hemoglobin A1 (HbA1) were measured before and after intensive insulin treatment. And, we calculated mean and standard deviation (S.D.) of FBS and US. After intensive insulin therapy, a significant difference of the S.D. of FBS was seen between group A and group B (p less than 0.01). And, a significant difference of M-value was found between group A and group B (p less than 0.05). As significant differences were observed between group A and group B, which could not be divided into two groups by conventional CPR measurement, it seems likely that metabolic stability in IDDM mainly result from minimal remaining residual beta-cell function.

Adolescent↗
PubMed1988

Xamoterol in patients with dilated cardiomyopathy: an increase in beta-receptors in lymphocytes.

Xamoterol, a partial-beta 1 agonist, was administered orally (100 mg, twice daily) to healthy volunteers (n = 8) and to patients with heart failure (n = 8) for one week. The density (Bmax) and affinity (Kd) of lymphocyte beta-receptors were lower in the patients with heart failure than in the healthy volunteers (Bmax = 931 +/- 214 vs 1466 +/- 373 sites/cell, and Kd = 0.60 +/- 0.11 vs 1.07 +/- 0.14 nM). During treatment with xamoterol, Bmax (7169 +/- 3768 and 7749 +/- 3807 sites/cell) and Kd (6.01 +/- 3.84 and 9.06 +/- 4.66 nM) increased strikingly (p less than 0.01) in both groups. For 12 months, xamoterol (100 mg bd) was given in the same manner to 10 patients with dilated cardiomyopathy. The long-term effects after three and 12 months were assessed. Xamoterol reduced the cardiothoracic ratio from 57 +/- 6% to 55 +/- 5% after three months and 54 +/- 5% after 12 months of treatment (both p less than 0.05), and increased exercise tolerance from 5 +/- 2 min to 7 +/- 2 min and to 7 +/- 2 min (p less than 0.01, p less than 0.05). Echocardiographic fractional shortening increased from 13 +/- 6% to 20 +/- 8% (p less than 0.01) and to 20 +/- 10% (p less than 0.05). Pulmonary wedge pressure during exercise at the same work load decreased from 40 +/- 12 mmHg to 25 +/- 9 mmHg (p less than 0.01) in three months; whereas pulmonary wedge pressures during exercise or at rest in 12 months were unchanged. Exercise heart rate decreased from 118 +/- 9 beats/min to 106 +/- 6 beats/min in three months (p less than 0.01), but was unchanged in 12 months. Bmax and Kd of the beta-receptors increased from 1024 +/- 413 sites/cell and 0.67 +/- 0.27 nM to 1976 +/- 497 sites/cell and 1.60 +/- 0.42 nM (both p less than 0.01), respectively, in three months, and 1584 +/- 650 sites/cell (NS) and 1.21 +/- 0.54 nM (p less than 0.05), respectively, in 12 months. It is concluded that xamoterol improves exercise tolerance, hemodynamics and resolves subjective symptoms for certain patients with dilated cardiomyopathy by its actions as a beta-agonist and beta-antagonist during longterm treatment.

Adaptation, Physiological↗
PubMed1988

[Myocardial involvement in female Fabry's disease: evaluation by thallium-201 myocardial scintigraphy].

Fabry's disease is characterized by an inherited X-linked disorder of glycosphingolipid catabolism, and heterozygous women affected with this disease who show overt symptoms including cardiac manifestations have rarely been reported. To elucidate the features of myocardial involvement in female patients, noninvasive techniques including exercise stress thallium-201 myocardial scintigraphy were performed. Three female patients, Cases 1-3, 26, 29 and 50 years of age, were documented low leucocytic alpha-galactosidase activities of less than 48% of normal (67.92-16.2 nmol/mg protein/h). They were examined using ECG, two-dimensional echocardiography (2-D Echo), Holter ECG, treadmill test and stress scintigraphy. On the ECG, negative T waves were shown in leads III and aVF in Cases 1 and 2. Left ventricular high voltage, giant negative T waves and short PR intervals were seen in Case 3. The 2-D Echo revealed neither valvular change nor left ventricular hypertrophy. On the Holter ECG, monofocal ventricular premature beats were occasionally observed in Cases 1 and 3. The treadmill test showed positive ST changes only in Case 2. On the exercise stress scintigraphy, uptake of thallium-201 was enhanced in the apex of the heart in Cases 2 and 3. Low uptake areas of thallium-201 were observed in Case 3. The ventricular angiogram revealed slight hypertrophy of the wall of the apical portion. In endocardial biopsies from the right ventricle, myelinoid lamellar inclusions were demonstrated in myocardial cells electron microscopically. Increased uptake of thallium-201 in the apex was noted in two of the three patients, but no apical thickening was noticed in any of the three cases by 2-D Echo. From the result of the biopsy of Case 3, the increased apical uptake of thallium-201 seems to reflect thickening caused by the deposition of glycosphingolipid. It was concluded that myocardial involvement in female Fabry's disease may occur early in the third decade and that the lesions could be detected with high sensitivity by thallium-201 myocardial scintigraphy.

Adult↗