Search PubMed⌕ Search

Biomedical subjects

T Kagawa

Publications and source records attributed to T Kagawa.

At least 109 records · Page 6Linked to original sources
PubMed1990

Phosphate and pepsin adsorptions by a new boehmite compound and aluminum hydroxide.

A new microcrystalline compound of aluminum oxide hydroxide (tentatively named PT-A) was synthesized in the hope of providing a better phosphate adsorbent for future clinical use than the currently marketed aluminum hydroxide gels (ALG). An X-ray diffraction study demonstrated a boehmite structure in PT-A but an amorphous structure in ALG. PT-A was more stable in pH change than ALG; in elution tests in artificial gastric and intestinal solutions, aluminum ion eluted from PT-A was maximally 10% of the amount from ALG at pH 1.2; and was undetectable at pH 6.8, at which point ALG still showed some aluminum elution. Phosphate-adsorbing efficacy of PT-A and ALG in vitro was about the same at pH 1.2; however, it was four times greater in PT-A than in ALG at pH 6.8, indicating that PT-A will be effective in the intestine. PT-A also adsorbed pepsin but the amount was at most the same or much less than that adsorbed by ALG, which depended on pH in solution.

Adsorption↗
PubMed1989

Establishment of a human cell line (HCC-T) from a patient with hepatoma bearing no evidence of hepatitis B or A virus infection.

A human hepatoma cell line, designated HCC-T, was established. The tumor was surgically obtained from a Japanese male patient with hepatocellular carcinoma (HCC) arising in a cirrhotic liver that had supposedly developed from nonAnonB (NANB) chronic hepatitis. HCC-T exhibited a typical morphology of epithelial cells in culture. Population doubling time was 24 hours and HCC-T cells had characteristics of malignant cells demonstrated by the ability to grow in a soft agar medium and transplantability to nude mice. The histologic condition of the tumor transplanted to a nude mouse showed similarity to the original tumor. A chromosome analysis showed that there were ten identifiable marker chromosomes and sex chromosomes with its modal number of 64. Alpha-fetoprotein (AFP) production was demonstrated by direct immunofluorescence study, but albumin or hepatitis B surface antigen were not detectable. The integration of hepatitis B viral DNA was not demonstrable in the genome of HCC-T cells or the original hepatoma.

Aged↗
PubMed1989

Hepatitis B virus DNA integration in hepatocellular carcinomas and their adjacent non-neoplastic liver tissues.

Hepatitis B virus (HBV) DNA integration was studied in 24 hepatocellular carcinoma (HCC) tissues obtained at operations or autopsies. In 11 cases whose sera were positive for hepatitis B virus surface antigen (HBsAg), HBV DNA integration was demonstrated by Southern blot analysis. Only one of 6 cases whose sera were positive for hepatitis B surface antibody (HBsAb) but negative for HBsAg revealed the integration and the other 5 cases revealed no HBV DNA integration. HBV DNA amplification was noted in 4 of these 6 cases in which HBV DNA integration was found when compared with the adjacent liver tissues. The integration pattern of HBV DNA was different in one case between primary HCC tissue and a metastasized lymph node. It is suggested that HBV DNA amplification is not directly related to the development of HCC and that there are polyclonal tumor cells which have different patterns of virus genome integrations.

Adult↗
PubMed1989

[Comparison of endocrine effects of hypotension induced by sodium nitroprusside, trimetaphan camsylate and a nitroprusside-trimetaphan mixture in rabbits].

Endocrine effects of hypotension induced by nitroprusside, trimetaphan and a nitroprusside-trimetaphan mixture were studied in 34 male rabbits under halothane anesthesia. They were randomly divided into four groups; nitroprusside (group N; n = 8), trimetaphan (group T; n = 10), a nitroprusside-trimetaphan mixture (group M; n = 8) and controls (group C; n = 8). No change was noted in plasma catecholamines measured in group C throughout the experiment, but plasma renin activity decreased progressively. During induced hypotension, plasma catecholamines and plasma renin activity of group N were significantly higher than the control value. In contrast, in group T plasma epinephrine decreased significantly. On the other hand, in group M, plasma renin activity showed a slight but not significant increase, while plasma catecholamines remained unchanged. This may have occurred since a mixture of nitroprusside and trimetaphan produced the dissociation of renin-angiotensin-sympathoadrenal loop. In conclusion, these results suggest that a nitroprusside-trimetaphan mixture is a useful method for hypotensive anesthesia by inhibiting the excessive activation of renin-angiotensin-sympathetic system.

Animals↗
PubMed1989

[Pseudomonas cepacia endocarditis successfully treated by surgery].

The patient was a 3-year-old female with coarctation of the aorta complicated by ventricular septal defect and mitral regurgitation. She underwent surgery for coarctation of the aorta at 7 months of age. We performed direct closure using a pledget for ventricular septal defect and valvoplasty with annuloplasty for mitral regurgitation. Infective endocarditis due to pseudomonas cepacia developed 3 months after the surgery, and echocardiography revealed vegetation in the ventricular septum and anterior leaflet of the mitral valve. After treatment with antibiotics, the second open heart surgery involving removal of the pledget used in the previous operation, reclosure of the ventricular septal defect, and mitral valve replacement was performed. The patient is healthy without recurrence of infective endocarditis 2 years and 2 months after the surgery.

Aortic Coarctation↗
PubMed1989

[Treatment of the infected emphysematous bulla].

From 1985 to 1987, we had 4 patients with infected emphysematous bulla, three males and one female ranging from 18 to 61 years of age. The male patients had been suffering from emphysematous bullae and had complications stemming from the resulting infection. In the female case, the infection occurred at the pneumatocele which had grown at pneumonia was caught during steroid therapy for SLE. While all cases were medicated with antibiotics intravenously, they were drained with a small caliber tube percutaneously, then were washed using a cytocidal agent (dilute povidone iodine). In two cases, an infected emphysematous bulla and an infected pneumatocele cleared, then shrank and closed. In the remaining cases, the infected emphysematous bullae also cleared and shrank, then the patients underwent operations. All patients then healed. The therapeutic combination of percutaneous drainage with a small caliber tube and washing of infected emphysematous bulla is available for therapy or preoperative treatment for the following reasons: First of all, especially in patients who have remarkably disturbed pulmonary function, it can be performed safely and pt's symptoms and the general condition of the patient improves rapidly. The second reason is that, in some particular cases, it achieves the remarkable shrinkage and closure of infected emphysematous bulla. The third reason is that, the patients experience minimum pain with the use of a small caliber drainage tube.

Adolescent↗
PubMed1988

NADP-malate dehydrogenase from leaves of Zea mays: purification and physical, chemical, and kinetic properties.

NADP-malate dehydrogenase (NADP-MDH) from leaves of Zea mays has been purified and has a specific activity of 600-1000 mumol/min/mg protein. The native, inactive form of the enzyme is an 87.4-kDa, dimeric protein with a sedimentation coefficient of 5.5 S and a Stokes' radius of 3.62 nm. Isofocus analysis reveals the native enzyme preparation to contain two proteins of pI 4.88 and 4.90. The uv-visible absorbance spectrum reveals no chromophores on the protein. The inactive form of the enzyme contains three thiols and three disulfides per subunit. 2-Mercaptoethanol can reduce two of the three subunit disulfides without concomitant activation of the enzyme. Treating the enzyme with dithiothreitol reduces all three subunit disulfides and fully activates the enzyme. These results show that NADP-MDH activation is dependent on the reduction of a critical disulfide bond. The enzyme can use both NADPH and NADH for oxaloacetate (OAA) reduction and NADP and NAD for malate oxidation at the following measured specific activities (eu/mg protein) at pH 8.5 in Tris buffer: NADPH plus OAA (690), NADH plus OAA (260), NADP plus malate (82), and NAD plus malate (37). These activities vary as a function of pH and buffer composition. Km values for the substrate pairs are NADPH (24 microM) plus OAA (56 microM); NADH (0.83 mM) plus OAA (61 microM); NADP (73 microM) plus malate (32 mM); and NAD (0.80 mM) plus malate (29 mM). The enzyme shows allosteric kinetics for NADP with a Hill number of 1.56. The enzyme is substrate-inhibited by malate for both NADP- and NAD-dependent activities.

Amino Acids↗
PubMed1988

Estimation of the transfer coefficients of oxygen and carbon monoxide in the boundary of human and chicken red blood cells by a microphotometric method.

The reaction rates of O2 and CO with the human and chicken red blood cell (RBC) were measured by using a microphotometric apparatus. In the experiments on the human RBC, a small amount of RBCs were put in an air-tight reaction cuvette. Gas mixtures containing various concentrations of O2 and CO were sequentially injected into the cuvette and the change in O2 and CO saturation of hemoglobin was measured from the change in transmission of the RBCs at 402 and 416.5 nm. The reaction rate of CO with RBCs was significantly influenced by photodissociation of carboxyhemoglobin (COHb). To eliminate this, a short-pass filter (400 to 435 nm) and a sector (100 Hz) were used. By comparing the measured reaction rates of O2 and CO with the theoretical rates obtained from the numerical solutions of the partial differential equations of the diffusions of O2 and CO, the transfer coefficients of O2 and CO (eta O2 and eta CO) in the RBC boundary, including the RBC membrane and water layer around the RBC, were estimated. Both the values showed good agreement, ranging from 0.3 to 2.5 x 10(-6) cm.sec-1.Torr-1. Furthermore, the chorioallantoic capillary of chicken embryo was used for the measurements of the reaction rates of O2 and CO with RBC through the capillary membrane. The reaction rates of O2 and CO in the chorioallantoic capillary were slower than those obtained in the human RBC. By comparing the measured reaction rates and the numerical solutions, the eta O2 and eta CO in the boundary, including the capillary membrane, plasma, and RBC membrane, were estimated. These two values ranged from 0.1 to 0.4 x 10(-6) cm.sec-1.Torr-1 and showed good agreement. These results suggest that the diffusion rates for O2 and CO across the capillary and RBC membrane are similar.

Animals↗
PubMed1988

Relationship between alveolar-arterial PO2 and PCO2 differences and the contact time in the lung capillary.

From the numerical solutions of simultaneous O2 and CO2 diffusions in the RBC, we calculated the P(A-a)CO2 by varying the tc at various PvO2 and PvCO2 levels, whereas the PAO2 and PACO2 were kept constant at 90 and 40 Torr, respectively. From the results we could clarify the relationship between the P(A-a)CO2 and the tc and its dependency on PvO2 and PvCO2. Furthermore, the influence of the tc on the C(a-v)O2, C(v-a)CO2 and R was clarified quantitatively.

Animals↗
PubMed1988

[Observation of the acrosome reaction of human spermatozoa using the combined preparation with triple stain technique and scanning electron microscopy].

The combination of triple stain technique (TST) and scanning electron microscopy (SEM) was used to investigate the reliability of TST in observing the acrosome reaction. The TST preparation was followed by SEM to observe the same spermatozoa by both methods. We compared the results obtained with TST at various pH of rose Bengal solution to those with SEM. 1. In our method, the acrosome reaction on the same spermatozoa was easily examined by both TST and SEM. 2. The fine surface structure of the sperm head was not affected by the TST procedure, because the percentages of acrosome non-reacted (ANR) and acrosome reacted (AR) sperm were similar when spermatozoa from the same semen were examined by SEM or SEM after TST (23.0%, 77.0% VS. 24.5%, 75.5%, respectively). 3. When results obtained with TST at various pH of rose Bengal solution were compared to those of SEM after TST, the accuracy was 70.5% at pH 4.3, 95.9% at pH 5.3 and 61.8% at pH 6.3. Sensitivity and specificity were 100%, 21.4% at pH 4.3, 94.5%, 97.6% at pH 5.3 and 38.7%, 97.5% at pH 6.3 respectively. From these results, it can be concluded that TST with pH 5.3 rose Bengal solution is a reliable and practical method for detecting the acrosome reaction of human spermatozoa.

Acrosome↗
PubMed1988

[Genesis and clinical significance of the "low-pitched" aortic ejection sound].

The genesis and clinical significance of the aortic ejection sound with a low-frequency predominance and delayed appearance were studied. This is recorded on the phonocardiogram in some patients with left ventricular dysfunction. Subjects studied consisted of 10 patients with a low-pitched ejection sound and seven patients with an ordinary high-pitched aortic ejection sound. No patients had echocardiographic findings suggestive of organic lesions of the aortic valve. Time relationships among the ejection sounds, aortic valve echograms and carotid artery pulses, and then movements of the aortic valve cusps and non-invasively estimated left ventricular systolic function were compared between the two groups. Results were as follows: 1. The low-pitched ejection sound: 1) The beginning of the sound was nearly coincident with the onset of the upstroke of the carotid artery pulse and the initial full opening of the aortic valve cusps. 2) The beginning of the ejection systolic murmur followed immediately after the ejection sound. 3) The amplitude of the sound was closely related to the height of the carotid artery pulse in a case of atrial fibrillation. 2. The low-pitched ejection sound vs the high-pitched ejection sound: 1) The onset of the low-pitched ejection sound was significantly delayed. 2) The amplitude and the velocity of the initial opening of the aortic valve cusps were significantly decreased. 3) The preejection period (PEP) was significantly prolonged; the ejection time (ET) was significantly shortened; and the PEP/ET ratio was significantly increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Aorta↗
PubMed1988

[Diastolic right ventricular hemodynamics in right ventricular overloads assessed by pulsed Doppler echocardiography].

To assess right ventricular (RV) filling dynamics, RV inflow velocity patterns of pulsed Doppler echocardiograms and jugular pulse tracings were analyzed in 59 patients with various types of RV overloads and in 20 normal subjects. The patients were classified as (1) RV volume overload group (RVVO) consisting of 25 patients with atrial septal defect (ASD) without pulmonary hypertension (PH), (2) RV pressure overload group consisting of 26 patients including 12 with primary pulmonary hypertension (PPH), eight with mitral stenosis, three with pulmonary stenosis and three with cor pulmonale, and (3) RV volume and pressure overload group consisting of eight patients with ASD and PH. The acceleration time (AT), deceleration time (DT) and the A/D ratio were measured from the RV inflow velocity patterns, and v-y interval and the y/H ratio were measured from jugular pulse tracings. The results were as follows: 1. AT was significantly prolonged in groups with pressure overload as well as pressure and volume overload compared with that of the normal controls. 2. DT was significantly prolonged in all overload groups compared with that of the normal controls except for PPH, and was particularly prolonged in the group with pressure overload. 3. The A/D ratio was significantly increased in all overload groups, particularly in the groups with pressure overload. 4. In patients with volume overloads, the v-y interval was longer and the y/H ratio was higher than in the normal controls. RVVO shifted to the right and superiorly. The reverse was true in the pressure overload group, and the high ratios were observed in the remainder. 5. In 12 patients with ASD evaluated pre- and postoperatively, AT, DT and the A/D ratio were restored to normal after surgery. These findings suggest that RV volume overload was characterized not only by increased inflow velocity during the rapid filling period, but prolongation of this period and compensatory increase of atrial inflow velocity. However, the pressure overload group had disturbed rapid filling and a decrease in end-diastolic RV compliance. The group with both pressure and volume overloads was between the two. In conclusion, the mode of RV filling in patients with RV overload showed various patterns depending on the type of overload. The RV inflow velocity pattern recorded by pulsed Doppler echocardiography is of use in discriminating these varieties.

Adult↗
PubMed1987

Theoretical analyses for arterial-venous O2 content difference and haldane effect during rebreathing.

The Haldane effect coefficient in vivo and arterial-venous O2 content difference [a-v)Co2) are, more or less, influenced by the contact time (tc), PO2 and PCO2 differences between venous blood and alveolar air. To increase the accuracy of the (a-v)CO2 and the cardiac output measured by means of the rebreathing technique, factors to correct the Haldane effect (F(H] and (a-v)CO2 (F(avCO2] were obtained theoretically from the numerical solutions of simultaneous O2 and CO2 diffusions in the red blood cell. Both the factors were complicated functions of tc, the difference in PCO2 between venous blood and alveolar air, as well as (a-V)CO2. For simplicity, we eliminated tc from the above functions by using the standardized relation between the tc and (a-v)CO2 measured from a rebreathing experiment in man. The F(H) was a linear function of (a-v)CO2. The (a-v)CO2 was calculated by dividing the product of F(H) and the slope of the CO2 dissociation curve by that of a gas exchange ratio against the PCO2 in rebreathing air. The F(avCO2) was given by a ratio of (a-v)CO2 at any alveolar PCO2 to the standard one, in which arterial blood has the same intracellular pH as that in venous blood. It was a linear function of the difference in PCO2 between venous blood and alveolar air, whose slope was inversely related to the (a-v)CO2 itself.

Arteries↗
PubMed1987

A method for estimating contact time of red blood cells through lung capillary from O2 and CO2 concentrations in rebreathing air in man.

The gas exchange ratio (R) obtained from O2 and CO2 concentrations measured in rebreathing air usually shows a linear relation to the PCO2. By referring to this relation and the R which equals the Haldane effect coefficient and zero, the true- and oxygenated-venous PCO2 are obtained in addition to the alveolar PCO2. When these PCO2 are evaluated, the R-PCO2 line can also be computed theoretically from a numerical solution on the overall O2 and CO2 diffusions in the red blood cell. By comparing both the experimental and theoretical R-PCO2 lines with each other, we derived a contact time equation. Since the linear approximation of the R-PCO2 relation gave rise to an error in the contact time (tc), first a factor to correct the linearity of the R-PCO2 line was derived. Next, using these parameter values, tc was quantitatively determined from experimental data obtained during rebreathing in 5 normal subjects and it was compared with that estimated from the pulmonary diffusing capacity for CO in the same rebreathing experiment. When the extracellular HCO3- dehydration rate was taken to be 0.1 s in time constant, the tc, being ca. 0.7 and 0.4 s at rest and during exercise, respectively, showed good agreement with those obtained from the diffusing capacity for CO.

Capillaries↗