Biomedical subjects

S Okubo

Publications and source records attributed to S Okubo.

At least 109 records · Page 6Linked to original sources

PubMed1990

Estimation of pulmonary hypertension by perfusion lung scintigraphy: gravitational effect of postural changes between the lateral decubitus positions.

To estimate pulmonary hypertension in patients with various heart diseases, we devised a new method using perfusion lung scintigraphy with technetium-99m-labelled macroaggregated albumin. In this method, changes in the distribution of pulmonary perfusion caused by gravitational effects, namely, changes in the total count ratios of the right lung against the left lung between right and left lateral decubitus positions (rt/lt), were assessed in 62 patients and in 10 normal subjects. The rt/lt ratios were calculated as indices of the above changes. They correlated significantly with mean pulmonary arterial pressure (mPAP) (gamma = -0.62, P less than 0.001), pulmonary capillary wedge pressure (gamma = -0.63, P less than 0.001) and pulmonary arteriolar resistance (gamma = 0.50, P less than 0.001) in all subjects. In 17 patients with valvular heart diseases, the ratio correlated significantly with mPAP (gamma = -0.84, P less than 0.001). In 10 patients with various heart diseases, the U/S ratio, i.e. the index of changes in the count ratios of the upper field against the lower field for the right lung following postural change from the upright to the supine position, was also obtained as well as the rt/lt ratio. The latter evidenced a better correlation with mPAP (gamma = -0.90, P less than 0.001) than the former (gamma = -0.64, P less than 0.05). We conclude that this method is valuable as a noninvasive approach for the estimation of pulmonary hypertension.

Female↗

PubMed1990

Hemolysis after intravenous immune globulin therapy: relation to IgG subclasses of red cell antibody.

A patient with chronic idiopathic thrombocytopenic purpura (ITP), a 28-year-old group A, Rh-positive woman, also had hemolytic anemia. At that time, her red cells typed as group A, but the serum typed as group O. This typing followed intravenous high-dose immune globulin therapy, (400 mg/kg for 5 successive days) and was attributable to A antibody of the IgG type, composed of IgG1, IgG2, IgG3, and IgG4, in the immune globulin preparation, which had been given for treatment of ITP. All lots of commercial human plasma preparation products (heat-treated human plasma protein, albumin, factor VIII or IX products, and immune globulin) examined were found to contain A and/or B antibodies of the IgM or IgG type, with titers of 1 to 1024. Twelve of the 20 lots of immune globulin contained RBC antibodies of the IgG type. Subclass IgG1 was found in all 12 of these lots, and all four subclasses, including IgG3, were detected in 8 lots. All 8 showed antibody titers higher than 64.

ABO Blood-Group System↗

PubMed1990

New tetrapolar circuit method using magnetic field for measurement of local impedance change in biological substances.

A new tetrapolar circuit method using a magnetic field is proposed to measure the local electric impedance change in living tissue. Based on this method, we designed an apparatus which can detect impedance changes in closely-situated two parts of living tissue, simultaneously and independently. Using this apparatus, we showed the effectiveness of the proposed method by an in vitro experiment and by an in vivo measurement of pulsatile waveforms in the forearm arteries. The detection sensitivity for a local impedance change was confirmed to be higher than that of the conventional tetrapolar method. Pulsatile impedance waveforms measured in the radial and the ulnar parts of the forearm were consistent with those estimated from the anatomical structure.

Arteries↗

PubMed1990

[HIV isolation and clinical markers on the seropositive subjects].

We investigated 18 anti-HIV seropositive subjects with respect to the isolation of HIV from peripheral blood mononuclear cells (PBMC) and cellular and serologic markers for progression to AIDS. The subjects included homosexuals and recipients of blood products. Three had AIDS, an asymptomatic subject developed AIDS during the study and 14 of the remaining have remained asymptomatic. HIV was isolated from all AIDS patients and 7 asymptomatic subjects. Moreover HIV was detected significantly sooner in symptomatic patients than in asymptomatic subjects. The reductions in CD4 lymphocytes number and CD4/CD8 ratio, as well as anti-HIV core (p24, p17) antigens negativity correlated with deterioration of clinical symptoms and successful HIV isolation. The isolates from AIDS patients and from an asymptomatic subject who 9 months later developed AIDS were infective and cytotoxic to MT-4 cells, however isolates from asymptomatic subjects were not infective. These findings indicate that disease progression correlates with the appearance of variant viruses that are more infective and cytopathic.

Biomarkers↗

PubMed1990

Control of ventilation in adult rats hypoxic in the neonatal period.

Three groups of 50-day-old (i.e., postpuberty) rats have been studied: controls, rats exposed to 6 days of hypoxia [inspired fraction of O2 (FIo2) = 10% O2] when newborn (Nb-Hypox), and rats exposed to the same level and duration of hypoxia after weaning (Ad-Hypox). Ventilation during normoxic breathing was higher in Nb-Hypox than in controls or Ad-Hypox. The ventilatory response to acute hypoxia (10 min of 10% O2) was about one-half in Nb-Hypox than in the other two groups. Additional measurements performed on Nb-Hypox and controls showed minimal or no differences between the two groups in the ventilatory responses to hyperoxia and hypercapnia, heart rate and blood pressure at various FIO2, and blood biochemistry. Analysis of the Hering-Breuer reflexes, during barbiturate anesthesia, suggested a decreased central inhibition on inspiratory activity in Nb-Hypox, which with a lower sensitivity to inputs from the peripheral chemoreceptors may contribute to the normoxic hyperventilation and the blunted response to acute hypoxia. The ventilatory patterns of Nb-Hypox rats bear numerous similarities with those of high-altitude natives and could suggest that the highlander's ventilatory responses are not genetic characteristics but relate to chronic hypoxia early in life.

Aging↗

PubMed1990

Computerized M-mode echocardiographic assessment of left ventricular diastolic function in patients with familial amyloid polyneuropathy.

To determine left ventricular diastolic properties in patients with familial amyloid polyneuropathy, 23 patients were studied by digitized M-mode echocardiography and were compared with 15 age-matched normal subjects. None of the patients had restrictive ventricular physiology and all but two showed normal left ventricular fractional shortening. Both the normalized peak rate of diastolic increase in left ventricular internal dimension and the normalized peak rate of diastolic thinning of posterior wall were significantly lower in patients than in normal subjects (2.0 +/- 0.8 vs 3.0 +/- 0.4 sec-1; p less than 0.001, and 2.5 +/- 1.2 vs 5.8 +/- 1.0 sec-1; p less than 0.001, respectively). The left ventricular isovolumic relaxation time in patients was 91.5 +/- 22.2 msec, compared with 64.0 +/- 2.6 msec in normal subjects (p less than 0.001). Of the 18 patients without clinical evidence of overt heart disease, 12 had normal ventricular wall thickness and normal fractional shortening, but 10 of the 12 exhibited some abnormalities in diastolic properties. In addition, indexes of diastolic function were significantly related to ventricular wall thickness alone. These findings indicate that left ventricular diastolic abnormalities precede the development of clinically overt heart disease, ventricular wall thickening, and systolic dysfunction and may be related to intramyocardial amyloid infiltration with resultant fibrosis in patients with familial amyloid polyneuropathy.

Adult↗

PubMed1990

Improvement in pulmonary function in mitral stenosis after percutaneous transvenous mitral commissurotomy.

Before and after percutaneous transvenous mitral commissurotomy (PTMC), pulmonary function studies were performed in 25 patients with mitral stenosis, in order to determine the effects of pulmonary hemodynamics on pulmonary function in patients with mitral stenosis. After PTMC, dramatic improvements in pulmonary hemodynamics were seen in all patients. With regard to pulmonary function data, the VC as percent predicted value increased from 87.6 +/- 16.1 percent to 94.7 +/- 14.4 percent (p less than 0.001). Although the ratio of FEV1/FVC was unchanged, the MVV as percent predicted value increased, and the ratio of RV/TLC, CV, and the difference in nitrogen concentration between 750 ml and 1,250 ml of expired volume decreased significantly. According to the maximum expiratory flow-volume curves, V ax 50% and Vmax 25% improved. Despite marked improvements in pulmonary ventilatory function soon after PTMC, the percent predicted diffusing capacity of the lung for carbon monoxide decreased significantly after PTMC. Arterial blood gas data, such as the partial pressure of oxygen and carbon dioxide in arterial blood and the alveolar-arterial differences in partial pressure of oxygen, did not improve within one or two weeks after PTMC. We conclude that in mitral stenosis, the majority of ventilatory function impairments are caused by hemodynamic alterations that are mainly reversible.

Adult↗

PubMed1990

[Antibacterial and anti-hemolysin activities of tea catechins and their structural relatives].

Among catechins tested, (-)epigallocatechin (EGC), (-)epicatechin gallate (ECg), (-) epigallocatechin gallate (EGCg) inhibited the growth of Staphylococcus aureus, Vibrio cholerae O1 classical Inaba 569B and El Tor Inaba V86. S. aureus was more sensitive than V. cholerae O1 to these compounds. EGCg showed also a bactericidal activity against V. cholerae O1 569B. Pyrogallol showed a stronger antibacterial activity against S. aureus and V. cholerae O1 than tannic and gallic acid. Rutin or caffein had no effect on them. ECg and EGCg showed the most potent anti-hemolysin activity against S. aureus alpha-toxin, Vibrio parahaemolyticus thermostable direct hemolysin (Vp-TDH) and cholera hemolysin. Among catechin relatives, only tannic acid had a potent anti-hemolysin activity against alpha-toxin. These results suggest that the catechol and pyrogallol groups are responsible for the antibacterial and bactericidal activities, while the conformation of catechins might play an important role in the anti-hemolysin activity.

Antitoxins↗

PubMed1990

[Relationship between the anti-hemolysin activity and the structure of catechins and theaflavins].

We examined the corresponding isomers of catechins and theaflavins for anti-hemolysin activities against Staphylococcus aureus alpha-toxin and Vibrio cholerae O1 hemolysin. Catechins and theaflavins showed anti-hemolysin activities in a dose-dependent manner. Among the catechins tested, (-)catechin gallate, (-)epicatechin gallate and (-)epigallocatechin gallate having galloyl groups in their molecules showed more potent anti-hemolysin activities against both toxins. On the other hand, free catechins, i. e. (-)catechin, (-)gallocatechin, (-) epicatechin and (-)epigallocatechin had low anti-hemolysin activities against alpha-toxin. Although (-)catechin or (-)gallocatechin had no effect on cholera hemolysin, (-) epicatechin and (-)epigallocatechin were slightly inhibitory. Among dextrocatechins, (+) epicatechin and (+)epigallocatechin proved to be more effective than (+)catechin and (+) gallocatechin. The anti-hemolysin activities of theaflavins against alpha-toxin and cholera hemolysin were dependent on the number of the galloyl group in their structure. These results suggest that the tertiary structure of the catechin or theaflavin and the active site of hemolysin, that affects the interaction between them, plays an important role in the anti-hemolysin activity.

Biflavonoids↗

PubMed1990

[Diaphragmatic fatigue under inspiratory resistive load in healthy subjects and the effect of several selections of frequency bands on the H/L (high/low) ratio].

In seven normal adult males the authors studied diaphragmatic fatigue by analysis of the power spectrum of the diaphragmatic electromyogram obtained with an esophageal electrode, and of the change of transdiaphragmatic pressure. Diaphragmatic fatigue was produced by inspiring through a resistive load, and mean value of the index of the tension time of the diaphragm (TTdi) maintained until fatigue was 0.33 +/- 0.09, which has been known to produce fatigue. The mean value of ratios of power at high frequencies to power at low frequencies (H/L) decreased to 61.2 +/- 16.8% of the initial value at just before breaking time. Breaking time was 4.88 +/- 1.37 minutes in average. The selection of low and high band widths for analysis of H/L ratio has differed slightly in the literature, but such differences do not have any substantial influence on the estimation of the changes of H/L ratio.

Adult↗

PubMed1990

[Autoimmune hemolytic anemia due to anti-e autoantibody of IgM class-report of a case].

A 83-year-old woman, complaining of jaundice and anemia, was diagnosed as autoimmune hemolytic anemia (AIHA) with bilirubin gall stones. Her red blood cell (RBC) group was A, Rh (D) +, but the details were indefinite due to transfusions previously repeated, while anti-C3d serum reacted positively in the direct antiglobulin test. Her serum reacted with RBC other than R2R2 in the albumin (37 degrees C) method and in the bromelin method, the reaction turning out negative after the pretreatment with 2ME. These findings indicated the autoantibody was anti-e of IgM class, which had been so far rarely reported in Japan.

Aged↗

PubMed1990

Significance of viral coinfections by HIV, HTLV-I, Epstein-Barr virus, and cytomegalovirus for immunological abnormalities in hemophiliacs.

In order to clarify the influence of viral coinfection on the immunological abnormalities of hemophiliacs infected with human immunodeficiency virus (HIV), 69 patients were examined. Of the 69, 35 (50.7%) were HIV-antibody positive (HIV-Ab+). Two of them were acquired immunodeficiency syndrome (AIDS) and the remaining 33 were asymptomatic carriers (AC). Anti-HTLV-I was found in 6 of 43 (14.3%), and 2 of these 6 were also HIV-Ab+. The frequencies of positive anti-viral capsid antigen (VCA) IgG against Epstein-Barr virus (EBV) and anti-cytomegalovirus (CMV) IgG were 47 of 51 (92.2%) and 42 of 49 (85.7%), respectively, while the titer of the former was higher in the HIV-Ab+ group than in the HIV-Ab- group (p less than 0.02). Nevertheless, no significant difference between these two groups was found as to the frequencies of these antibodies and of such early markers as anti-VCA IgM, early antigen (EA)-DR, and anti-CMV IgM. The results obtained showed no significant evidences that these viral superinfections facilitate the immunosuppression due to the HIV itself as correlated with the HIV antigenemia (thus accelerating the development of AIDS), or that they promote its autoantibody production. However, such possibilities did seem to be undeniable in some HIV-infected patients.

Adolescent↗

PubMed1990

[Continuous monitoring of mixed venous oxygen saturation during exercise using fiberoptic pulmonary artery catheter].

We measured the mixed venous oxygen saturation (SvO2) continuously using a fiberoptic thermodilution pulmonary artery catheter to analyze the time course of SvO2 during exercise, and evaluated the relationship between SvO2 and exercise load, SvO2 and cardiac output. Five patients with old myocardial infarction and one healthy man underwent pulmonary arterial catheterization and then performed an incremental steady state exercise test using a supine cycle ergometer. There was a rapid fall in SvO2 43.4 +/- 10.6 seconds after the start of exercise and new steady state were achieved 92.6 +/- 22.5 seconds after changing the exercise load. The value of SvO2 at exercise load 60 watts were 44.7 +/- 9.8% and this value was under the level of lactic acid accumulation. SvO2 correlates well with cardiac output by the thermodilution method in individual patients. We conclude that a fiberoptic thermodilution pulmonary artery catheter was useful to evaluate the dynamic changes of SvO2 during exercise.

Adult↗

PubMed1990

[A successfully operated case of tetralogy of Fallot with marked left ventricular dysfunction in adult].

Adults, especially high-aged patients with tetralogy of Fallot (TOF) are said to have a higher operative risk than younger ones because of fragility of their myocardium, bleeding from rich collateral circulation to lungs, and other complications such as brain abscess and endocarditis. It is often difficult to determine the surgical risk for total correction in cases of high-aged patients who have such complications. We report a successfully operated high-aged case of TOF with marked left ventricular dysfunction. A 52-year-old male was referred to our hospital because of exertional dyspnea and cyanosis. He had a history of cerebral embolism and meningitis several months prior to admission. On admission, he was NYHA class 3, and cyanosis and clubbed fingers were present. Cardiac catheterization showed a large VSD, 50% over-riding of the aorta and an infundibular pulmonary stenosis. Right to left shunt was 60% and Qp/Qs was 0.38. The left ventricular end diastolic volume index was 109 ml/m2, slightly larger than normal, and the ejection fraction was only 30%. This left ventricular dysfunction was thought to be caused by fibrosis of the myocardium due to longstanding hypoxemia and hypoxemia itself. There is no previous case report dealing with a successful total correction for a high-aged patient with TOF associated with such a severe left ventricular dysfunction. Congestive heart failure in the post-operative period was successfully treated by catecholamine for two weeks. Postoperative cardiac catheterization showed a small left-to-right shunt, and an improvement of left ventricular ejection fraction from 30% to 38%.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

PubMed1990

[IgG subclasses of warm red cell autoantibodies in autoimmune hemolytic anemia].

IgG subclasses (G-sub) of warm red cell autoantibodies (anti-Rs) were examined by means of antiglobulin test (DAT) using anti-IgG1, 2, 3, and IgG4 sera (Holland Red Cross) on 12 AIHA, and on 5 cases being DAT positive caused by alpha-methyldopa (alpha MD). In 4 of 5 AIHA cases complicating SLE, the anti-Rs comprised not only IgG, but also IgA, IgM and C3; their G-sub were IgG1 + 2 in 2 and IgG1 + 2 + 3 + 4 in the other 2. In all of the 3 cases with idiopathic AIHA, anti-Rs comprised IgG alone (IgG1 alone, IgG1 + 3 or IgG1 + 2 + 3 in each one). All of the 5 alpha MD induced anti-Rs comprised IgG1 alone. Observation of the course of AIHA revealed that, although IgG3 tended to correlate with their anemia, this trend was not universal. Besides, the G-sub were not related to the anti-Rs titers. Furthermore, the immunological aberrations in patients with AIHA + SLE were found to be more complicated.

Anemia, Hemolytic, Autoimmune↗

PubMed1990

[Estimation of pulmonary intravascular and extravascular spaces by 99mTc-albumin lung distribution ratio and 201Tl lung uptake ratio].

In order to estimate the pulmonary extravascular and intravascular spaces, lung uptake ratio of 201Tl (L/T) and lung distribution ratio of 99mTc-albumin (H/T'), expressed as ratios of total counts of the bilateral lungs to the administered doses of the radionuclides, were obtained from the both scintigrams with 201Tl and 99mTc-albumin respectively, using a scintillation camera coupling to a minicomputer. Mean values of L/T and H/T' were 2.8 +/- 0.8% and 4.9 +/- 1.4% in the controls, 3.9 +/- 1.8% and 5.3 +/- 1.9% in heart diseases without left heart failure, and 7.0 +/- 2.2% and 7.1 +/- 2.9% in those with left heart failure, respectively. Ratios of L/T to H/T' in diffuse interstitial pneumonia and heart diseases, especially in cases with left heart failure were higher than those in controls. The values of H/T' and L/T were inversely proportional to cardiac output and cardiac index, and the values of L/T were directly proportional to pulmonary artery wedge pressure, but the discrepancies of the relationship between these values and some clinical findings including cardiac output, cardiac index, pulmonary artery wedge pressure and other findings of left heart failure, were observed in not a few cases. In the regional pulmonary areas, lung uptake of 201Tl was in parallel with pulmonary perfusion in many cases, but the discrepancies between them were demonstrated in some cases, too. These methods seem to be useful for the estimation of the pulmonary extravascular and extravascular spaces, and for the detection of dysfunction of the left ventricle.

Cardiac Output↗

PubMed1990

[A case of Behçet's disease with hemoptysis and chest X-ray abnormality].

A 41-year-old man was admitted to our hospital because of hemoptysis and dyspnea. Physical examination disclosed oral ulcer, acne and scrotal ulcer. Although ocular lesions were absent, the needle reaction was positive. Then we diagnosed this case as incomplete type of Behçet's disease. Chest X-ray showed diffuse retinolinear shadows in the entire lung field and an infiltrative shadow in the left middle lung field. CT-scan revealed interstitial shadows in the entire lung field, a wedge-shaped shadow in left S6 and aneurysmic dilatation of the left lower lobe pulmonary artery. Pulmonary angiography showed obstruction and aneurysmic dilatation of the left lower lobe pulmonary artery. Pathological examination of the TBLB specimen revealed thickening of the vessel wall, perivascular infiltrations of mononuclear cells, hemorrhage and slight thickening of alveolar septae. These findings were compatible with pulmonary lesions of Behçet's disease. After administration of corticosteroid, the symptoms and the chest roentgenographic findings improved. Pulmonary lesions of Behçet's disease were discussed.

Adult↗

PubMed1990

[Acute fatal pulmonary embolism: its prevention, diagnosis and treatment].

Acute fatal pulmonary embolism is one cause of sudden death which should be guarded against. It is the most often missed diagnosis in sudden death cases within the hospital. Clinical pictures of 10 patients with acute fatal pulmonary embolism proved by autopsy were examined to elucidate the problems of diagnosis, and to look for an effective treatment, and a method of prevention. Common risk factors were old age and immobility due to stroke or postoperative state. Common past histories were hypertension, diabetes mellitus, obesity, atrial fibrillation and hyperlipidemia. Electrocardiogram and echocardiogram showed that in these patients there was definite evidence of acute right ventricular overload. High doses of intravenous urokinase should be given whenever acute cardiovascular collapse develops in such high risk patients. Emergent pulmonary angiogram and pulmonary embolectomy could be life-saving in patients with acute massive pulmonary embolism. Prevention is, however, the best treatment. In addition to anticoagulation medication, frequent change of body position and early mobilization are important precautions to prevent fatal pulmonary embolism developing in such patients.

Acute Disease↗