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Biomedical subjects

J Takezawa

Publications and source records attributed to J Takezawa.

At least 37 records · Page 2Linked to original sources
PubMed1992

Efficacy of oral treatment with BV-araU against cutaneous infection with herpes simplex type 1 in shaved mice.

The effect of oral BV-araU was tested in cutaneous model infections of shaved Balb/c mice with herpes simplex virus type 1 (HSV-1). Progression of cutaneous symptoms associated with cutaneous infection with HSV-1 F strain was inhibited by BV-araU at doses of 20 and 50 mg/kg twice daily, beginning one day post-infection, resulting in significant increase in the survival rate. Onset of disease was suppressed in most animals receiving 100 mg of BV-araU per kg. BV-araU (20 mg/kg or more) also significantly increased the survival rate of mice infected with HSV-1 WT-51 strain. The efficacy of BV-araU was not affected by gender or age (6-9 weeks) of the mice. BV-araU was effective even when the treatment was started 2.5 days post-infection. The efficacy of BV-araU against F strain infection was comparable to that of acyclovir, but acyclovir showed therapeutic effects at lower doses compared with BV-araU against WT-51 strain infection. Against infection of cyclophosphamide-treated immunosuppressed mice with HSV-1 KOS(S) strain, BV-araU decreased the morbidity rate and severity of symptoms at doses of 200 and 100 mg/kg, respectively, and all mice given 50 mg of BV-araU or more per kg survived, suggesting oral efficacy can be achieved against HSV-1 infections in immunosuppressed individuals.

Acyclovir↗
PubMed1992

[Clinical evaluation of serum levels of monomeric dimeric and tetrameric pseudocholinesterases in patients with various liver diseases].

Serum levels of monomeric, dimeric and tetrameric pseudocholinesterases were measured by means of enzyme-linked immunosorbent assay in patients with various liver diseases and normal controls in order to evaluate their clinical significance. In patients with liver cirrhosis, serum levels of monomeric, dimeric and tetrameric were significantly lower than those in normal controls, patients with fatty liver and chronic hepatitis. The ratio of monomeric and dimeric to tetrameric in patients with liver cirrhosis was also significantly lower than that in normal controls, patients with fatty liver and chronic hepatitis. Serum levels of tetrameric, dimeric and monomeric were not significantly higher in the patients with fatty liver than in normal controls, but the ratio of monomeric and dimeric to tetrameric was significantly higher in patients with fatty liver than that in normal controls, patients with chronic hepatitis and liver cirrhosis. These findings suggest that the selective determinations of serum levels of monomeric, dimeric and tetrameric pseudocholinesterases are useful to estimate the metabolism of fat and protein in various liver diseases.

Adult↗
PubMed1992

[Studies on the glucose tolerance and the endocrine function of the pancreas in primary sclerosing cholangitis].

The responses of serum IRI, serum IRG, and blood sugar levels to 75 g oral glucose and serum IRI to glucagon injection were investigated in 26 chronic hepatitis, 20 liver cirrhosis, 5 primary sclerosing cholangitis (PSC) and 8 healthy volunteers served as controls. The results obtained herein were as follow: 1) The frequency of the glucose intolerance in PSC was higher than the other liver diseases. The mean values of the insulinogenic index (delta IRI/delta BS 30 min) in PSC was lower than control subjects. No suppression of IRG by glucose was observed in PSC. 2) The maximum IRI value (max delta IRI) in PSC during glucagon test was lower than that in control subjects. 3) In one case of 5 PSC ICSA was founded to be positive. These data suggest that we should pay much attention to suffering from diabetes mellitus in natural history of PSC.

Aged↗
PubMed1991

Evaluation of a new reflectance pulse oximeter for clinical applications.

The design of a noninvasive reflectance pulse oximeter that uses the same principle of transmittance pulse oximeter and analyses the oxygen saturation of arterial blood was described. Four sets of red and infra-red LEDs were used as light sources. The respective reflectance photoelectric outputs were used to make an internal calibration curve of the instrument relative to the arterial oxygen saturation values measured with a Co-Oximeter (OSM-3) in five healthy nonsmoking subjects during steady-state hypoxaemia. The accuracy of the present instrument was studied in six patients with respiratory failure. From 22 samples, a good correlation coefficient (0.98) with a standard deviation of 1.42 was obtained in the range between 73 and 100 per cent between the arterial oxygen saturation measured with the present instrument and that with the Co-Oximeter. The result strongly suggests the usefulness of this oximeter in monitoring patients with hypoxaemia.

Adult↗
PubMed1991

Determination of the optimal pressure support level evaluated by measuring transdiaphragmatic pressure.

The purpose of this study was to determine the optimum pressure support (PS) in six patients with respiratory failure. Esophageal pressure (Pe), gastric pressure (Pg), airway pressure, and transdiaphragmatic pressure (Pdi), obtained by subtracting Pe from Pg, were measured using a newly developed multiluminal nasogastric catheter. For each patient, different PS levels were selected every 20 minutes, and measurements were made at each PS level. We defined the optimum PS level as the level that showed the minimum Pe value. Respiratory rate (RR) decreased and tidal volume (VT) increased with an increase in PS level. RR and VT at the optimum PS were 19.7 +/- 5.5 breaths per minute and 11.7 +/- 4.5 ml/kg, respectively. Pdi decreased linearly with increasing PS level in all patients. Mean Pdi at the optimum Ps was 4.2 +/- 1.2 cm H2O. Based on the relationship between Pdi and PS level, we constructed an equation to estimate the optimum PS level as follows: Optimum PS level = [( Pdi during T-piece mode] - 4)/0.8. We conclude that Pdi measurement is helpful for titrating the required PS level.

Adult↗
PubMed1991

Comparison of inspiratory work of breathing in T-piece breathing, PSV, and pleural pressure support ventilation (PPSV).

We have compared the inspiratory work of breathing during T-piece breathing, pressure support ventilation (PSV), and pleural pressure support ventilation (PPSV) by using a lung model with variable compliance and resistance, under simulated spontaneous breathing. Our lung model consists of two spring-loaded bellows, representing the lung and diaphragm, placed in an airtight container. Inspiration begins with the withdrawal of air from the diaphragm bellows by a time-cycled jet-flow-creating Venturi mechanism. Expiration occurs by opening the diaphragm bellows to the atmosphere. Work of breathing (WOB) is calculated by plotting the pressure-volume curve, with pressure corresponding to intrabox pressure and volume corresponding to the tidal volume; PPSV is a new mode of mechanical ventilatory support accomplished by setting the ventilator (Servo 900C) into the PSV mode with a level of 0 cm H2O, using the pleural pressure as the input and target signal. The PPSV maximally reduces WOB under any circumstances. The PSV sufficiently reduced WOB only in the normal lung and the lung with low compliance; however, a pressure supporting time is diminished in the lung with low compliance. The serious limitations of PSV remain in its application to the lung with high resistance. It is concluded that PPSV is closer to the actual patient's signal and has a potential advantage in reducing WOB in the lung with low compliance or high resistance (or both). The lung with flow limitation is still a challenging issue for mechanical ventilatory assistance.

Humans↗
PubMed1990

Immunocytochemical studies on cholestatic factor in human liver with or without cholestasis.

The localization of the cholestatic factor (CF) was immunocytochemically investigated in liver biopsy specimens obtained from patients with various liver diseases. CF was detected in seven of nine patients with drug-induced liver injury, three of four with acute viral hepatitis, three of five with alcoholic liver injury and in the two patients with autoimmune hepatitis. Fourteen of these 15 CF-positive patients had jaundice in their clinical courses. CF was stained diffusely in the cytoplasm of hepatocytes throughout the lobules in a granular pattern. Electron-microscopically, it was localized on the ribosomes and polysomes as well as on the filamentous structures around the bile canaliculi. However, CF was not detected in liver specimens from normal controls and patients with primary biliary cirrhosis and extrahepatic biliary obstruction. These findings suggest that CF plays an important role in intrahepatic cholestasis in various liver diseases.

Adult↗
PubMed1990

Effect of 1-beta-D-arabinofuranosyl-E-5-(2-bromovinyl)uracil (brovavir) on experimental infections in mice with herpes simplex virus type 1 strains of different degrees of virulence.

In vivo antiherpesvirus effects of 1-beta-D-arabinofuranosyl-E-5-(2-bromovinyl)uracil (brovavir) were tested in two mouse model infections with herpes simplex virus type 1 (HSV-1) strains which showed different degrees of virulence in mice. Successful efficacies of oral and intraperitoneal (i.p.) treatments with brovavir were demonstrated in both intracerebral and i.p. infections with the HSV-1 WT-51 strain of moderate virulence. However, only weak or modest effects of brovavir were observed against the two model infections with a highly virulent strain, HSV-1 VR-3. Brovavir was not effective in reducing mortality of mice infected i.p. with HSV-1 KOS, which exhibited the highest virulence in mice among HSV-1 strains used when inoculated i.p. However, the drug had a significant effect on intracerebral infection with the KOS strain. Efficacies of oral treatment with brovavir were almost equal to those of i.p. administration in the model infections. After intracerebral inoculation, the VR-3 strain grew in brains of mice at a higher rate than the WT-51 strain. By oral treatment with 50 mg of brovavir per kg twice daily, replication of the WT-51 strain in the brains was markedly suppressed and was eliminated after transient elevation of the titer. Growth of the VR-3 strain in the brains was simply delayed by the drug treatment. Thus, the antiviral efficacy of brovavir in mice was affected by the degree of virulence of the challenge virus strain used for infection.

Animals↗
PubMed1990

Measurement of functional residual capacity during high-frequency oscillatory ventilation (HFOV) by argon washout method without interruption of HFOV.

A modified indicator gas washout method was developed to measure functional residual capacity (FRC) during high-frequency oscillatory ventilation (HFOV) without interruption of HFOV. A hot-wire flowmeter and medical gas analyzer measured the flow rate and argon concentration, respectively, at the expiratory end of the respiratory circuit. Upstream of the hot-wire flowmeter, two heat-and-moisture exchangers for resistance and a rubber balloon for capacitance were placed to convert the oscillating expiratory flow to an almost continuous flow. This made it possible to measure FRC during HFOV without interrupting HFOV. To measure the volume of the entire respiratory circuit, a 10 percent argon in 90 percent oxygen gas mixture was initially used as a bias flow, and after equilibration, the test gas was switched to 100 percent oxygen. By electrical integration of the product of the expiratory flow rate and argon concentration, the total amount of argon equilibrated in the entire respiratory circuit was calculated. The volume of the circuit was calculated by dividing the total amount of argon by the initial argon concentration. Functional residual capacity plus the volume of the respiratory circuit was similarly calculated and the difference was estimated as FRC. The accuracy and reproducibility of our method were evaluated by using a one-compartment lung model. There was a high correlation between the volume setting of the model lung and the estimated FRC. This method can be used to estimate FRC in a one-compartment lung model during HFOV, and it is potentially useful in clinical situations.

Argon↗
PubMed1990

[A study on the utility of flumazenil for patients in the ICU].

Flumazenil, a specific antagonist of benzodiazepines, was administered to adult patients receiving treatment at ICU, and its utility to hasten recovery from sedation was evaluated in 40 patients and its usefulness for differential diagnosis of sedated conditions was also evaluated in 5 patients. The efficacy rate for recovery from sedation induced by benzodiazepines was 85.0%. Moreover, flumazenil was considered to be useful for differentiation of sedated conditions when causes were unknown. Depression of respiration improved in association with improvement of consciousness level. In some patients an elevation in blood pressure was also observed with improved consciousness.

Adult↗
PubMed1990

[Clinical evaluation of serum biotin levels and biotinidase activities in patients with various liver diseases].

In order to evaluate the clinical significance of serum biotin and biotinidase in liver disease, serum biotin levels and biotinidase activities were determined in 83 patients with various liver diseases and 10 healthy controls. Serum biotin levels and biotinidase activities were determined by a simplified lactobacillus plantarum bioassay and liquid chromatography with fluorimetric detection respectively. Serum biotin levels in decompensated liver cirrhosis, hepatoma and fulminant hepatitis were found to be significant low compared with healthy controls, while it was significant high in autoimmune hepatitis. There was no significant difference between serum biotin levels in the other liver diseases and healthy controls. In various liver diseases except for both acute hepatitis and alcoholic liver disease biotinidase activities were significantly reduced than in healthy controls. Serum biotinidase activities were correlated with serum albumin, prothrombin time, ChE and total cholesterol respectively, suggesting that biotinidase activities may reflect the degree of liver damage. These results seem that biotin deficiency may occur in some cases of severe liver diseases.

Adult↗
PubMed1990

[Measurement of flow-resistive work of heat and moisture exchangers during simulated active breathing].

The performance of seven commercially available heat and moisture exchangers (HME) was evaluated in the dynamic flow state. A piston pump was used as a simulator with operative conditions with stroke volume of 500 ml and with respiratory rates of 20 and 40 cycles.min-1. A pressure-volume loop was produced for each HME and the flow-resistive work calculated. Each HME was studied under both dry and wet conditions. It was found that the flow-resistive work of the Humid-Vent 2 was the smallest and that of the Breathaid the largest under both conditions. The results suggest that application of HME causes a significant increase in resistance and demands a greater breathing effort from patients. Its use should thus be avoided in marginal patients.

Anesthesiology↗
PubMed1989

[Clinical studies using a highly sensitive radioimmunoassay for mid-region and carboxy terminus of parathyroid hormone in normal, hypo- and hypercalcemic states].

Parathyroid hormone radioimmunoassay (RIA), specific for mid-region of the PTH molecule, has been proven to be extremely useful for the differential diagnosis of abnormal calcium metabolism. Recently, we developed a highly sensitive RIA for PTH, consisting of PTH antiserum (CH9), 125I labelled Tyr42 hPTH (43-68) and synthetic hPTH (1-84) as standard. This RIA cross-reacted with mid-region and carboxyl terminals of PTH. The within-assay and between-assay coefficients of variation were less than 4.6% and less than 8.6%, respectively. The limit of detection was 50pg/ml. The levels of serum calcium, serum phosphate, serum creatinine, Tmpo4/GFR and creatinine clearance (Ccr) in normal healthy volunteers aged 20 to 50 years remained almost constant and showed 9.24 +/- 0.34mg/dl (mean +/- SD, n = 242), 3.34 +/- 0.38mg/dl (n = 242), 0.870 +/- 0.121mg/dl (n = 242), 3.20 +/- 0.54mg/dl GF (n = 189) and 103 +/- 17ml/min (n = 137), respectively. All healthy volunteers (n = 326) had measurements of PTH in the blood. From 20 to 50 years, normal PTH mean was 374 +/- 97pg/ml (+/- SD, n = 237) and ranged from 180-568pg/ml, and from 60 to 80 years it was 471 +/- 133pg/ml (n = 34) and ranged from 205-737pg/ml. Since we found that PTH was markedly elevated above normal when Ccr was below 40ml/min, and PTH was very significantly correlated with the reciprocal of Ccr (r = 0.8996, P less than 0.001) using a multivariate analysis, all of the patients whose Ccr was higher than 40ml/min were selected and examined in the following studies. Serum PTH values completely separated patients with surgically proven primary hyperparathyroidism (1 degree HPT) from malignant associated hypercalcemia (MAH), and patients with idiopathic hypoparathyroidism (IHP) from pseudohypoparathyroidism (PHP), both of which were diagnosed by Ellsworth-Howard test. PTH values in all of the patients with 1 degree HPT (n = 23) were above normal, but those with MAH (n = 6) were below the normal or lower normal range. PTH values in patients with PHP (n = 7) showed above normal, while those with IHP (n = 5) were below the normal range. PTH was normalized in post operative status in all patients after parathyroidectomy (n = 6). These results indicate that this PTH RIA is extremely useful for the differential diagnosis in diseases with calcium abnormalities.

Adolescent↗
PubMed1989

A case report of transcatheter arterial embolization of cholestatic type of hepatoma.

A 57-year-old man with hepatocellular carcinoma (HCC) invading the hepatic duct was treated with transcatheter arterial embolization (TAE). The dilated hepatic duct was decompressed his jaundice disappeared and he survived for 10 months after the first TAE, succumbing due to bleeding from gastric erosion. Although total bilirubin was 26.7 mg/dl and massive ascites was noted on occasion of the first TAE, hepatic dysfunction did not worsen and both icterus and ascites decreased, disappearing one month after the therapy. Autopsy revealed HCC with trabecular arrangement originating in the left lobe and growing into the left hepatic duct accompanied by liver cirrhosis and follicular carcinoma of the thyroid gland. Severe icterus caused by bile duct obstruction does not correlate with the grade of hepatic failure in HCC with liver cirrhosis, so TAE was effective and should be tried as a first choice therapy in such a poor risk case.

Carcinoma, Hepatocellular↗