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Biomedical subjects

J Sato

Publications and source records attributed to J Sato.

At least 307 records · Page 17Linked to original sources
PubMed1991

Fluctuating CPAP (F-CPAP) versus conventional CPAP (C-CPAP) in dogs with blood aspiration.

Fluctuating CPAP(F-CPAP) is a combination of spontaneous ventilation and fluctuating PEEP, in which end-expiratory pressure (EEP) is periodically changed within a certain range. In a dog model with localized lung injury induced by the aspiration of non-heparinized blood (2 ml.kg(-1) body weight), we carried out a comparative study of the effects of F-CPAP in which the EEP was cyclically changed from 4 to 12 cmH(2)O with periods of 10 min and those of conventional CPAP with a fixed EEP of 8 cmH(2)O (C-CPAP), on hemodynamics and pulmonary oxygenation. The blood aspiration produced significant increases in the intrapulmonary shunt (Qsp/Qt), the alveolar-arterial difference of partial pressure of oxygen (A-aD o(2)), and the respiratory rate (RR). Although both F-CPAP and C-CPAP reduced Qsp/Qt and A-aD o(2) and RR, 7 dogs treated with F-CPAP showed a significantly greater recovery of Qsp/Qt and A-aD o(2) than 7 dogs treated with C-CPAP. There were no significant differences in hemodynamic variables between the two groups. These results suggest that F-CPAP is more useful in the treatment of some kinds of hypoxic respiratory failure due to uneven distribution of lung injury.

Journal Article↗
PubMed1991

Gas physical properties and respiratory system resistance measured by flow interruption.

If the flow of gas at the airway opening of a tracheostomized dog is suddenly interrupted during expiration, the airway pressure exhibits a sudden very rapid rise, called delta Pinit, which has been shown previously to equal the resistive pressure drop across the airways in open-chest dogs, and to have a significant additional contribution from the tissues of the chest wall in intact dogs. In the present study we attempted to separate the contributions of airways and tissues to delta Pinit in intact dogs by performing flow interruptions with the lungs full of gas mixtures having different physical properties. A Moody plot (the Friction coefficient calculated using delta Pinit versus the Reynolds number) had a marked negative slope at Reynolds numbers up to 5 x 10(4), whereas the plot is predicted to have a slope close to zero at Reynolds numbers greater than 4 x 10(3) on the basis of purely fluid dynamic considerations. Assuming delta Pinit to be the result of a linear dependence of airway resistance on flow and a constant tissue resistance, we were able to account for the negative slope of the Moody plot. We also found that the values of airway and tissue resistances estimated from the data were very close to those estimated by more direct means in a previous study of delta Pinit. We conclude that it is possible to discern the separate effects of airway and tissue resistances in delta Pinit at high Reynolds numbers.

Airway Resistance↗
PubMed1991

[A clinical experience of rokitamycin on Campylobacter enteritis. Research Group of Rokitamycin on Infectious Enteritis].

Rokitamycin, a newly developed macrolide, was administered to a total of 107 cases, 16 years old or more, in order to evaluate its clinical efficacy, safety and usefulness on Campylobacter enteritis. Daily dosage of 600 mg of rokitamycin was administered orally in three divided doses for 5 days. Bacteriological and clinical efficacies were judged by the attending doctors from the evaluation criteria made by the committee and from the days required for improvement of diarrhea, defervescence and so on, respectively. Antibacterial activities against the isolates were tested of rokitamycin (RKM), erythromycin (EM), josamycin (JM) and ofloxacin (OFLX). The results were as follows; 41 symptomatic patients and 5 carriers were evaluated. Clinical efficacy (n = 41) was 100% (excellent; 34.1%, good; 65.9%). Bacteriological efficacy (n = 41) was 97.6%. Eight of the 9 cases with consecutive stool cultures were free of the bacteria on and after one day of the drug administration. Clinical usefulness (n = 46) was 97.8%. Slight epigastric pain was seen in only one as a side effect. The items of abnormal laboratory findings were 4 elevated GPT and/or GOT and one increased number of WBC in 4 cases. MIC90 of RKM, EM, JM and OFLX against 41 clinical isolates of C. jejuni were 1.56, 3.13, 3.13 and 0.78 micrograms/ml, respectively. Rokitamycin was considered clinically useful to treat Campylobacter enteritis.

Adolescent↗
PubMed1991

[Comparison of clinical efficacy of rokitamycin (RKM) and ofloxacin (OFLX) for the treatment of Campylobacter enteritis by a double-blind method. The Research Committee for the Effect of Rokitamycin, Research Group for Infectious Enteritis].

The clinical efficacy, safety and usefulness of Rokitamycin (RKM), a new macrolide antibiotic, were compared with those of Ofloxacin (OFLX) for the treatment of Campylobacter enteritis by a double blind method. The daily dose level of RKM or OFLX was 600 mg. They were orally administered in three divided doses for 5 days. Of 223 cases studied, 106 cases were diagnosed as Campylobacter enteritis. Ninety cases (RKM group: 50, OFLX group: 40) except for 16 excluded or drop-out cases were analysed. There was no significant difference between the two groups in any background factors. The effectiveness and usefulness was evaluated in 88 cases (RKM group: 48, OFLX group: 40). The results obtained were as follows: 1. In a total of 82 strains of Campylobacter jejuni/coli (RKM group: 42, OFLX group: 40), the bacteriological efficacy rate of RKM (95.2%) was superior to that of OFLX (70.0%) with a significant difference (p = 0.006). 2. In 76 symptomatic patients (RKM group: 42, OFLX group: 34) on the day of the beginning of drug administration, the clinical efficacy rate was 97.6% in the RKM group and 85.3% in the OFLX group with no significant difference between the two groups. 3. In 88 evaluable patients, the global clinical efficacy rate of RKM (95.8%) was superior to that of OFLX (67.5%) with a significant difference (p = 0.001). 4. Side effect was observed in 1 (1.9%) of the 54 patients in the RKM group and none of the 44 patients in the OFLX group. Slightly abnormal laboratory findings were seen in 4 (10.8%) of the 37 patients treated with RKM and 3 (9.7%) of the 31 patients treated with OFLX, but there was no significant difference between the two groups. 5. In 88 evaluable patients, the clinical usefulness of RKM (91.7%) was superior to that of OFLX (67.5%) with a significant difference (p = 0.01). From these results, RKM is considered to be a very useful agent for the treatment of Campylobacter enteritis.

Adolescent↗
PubMed1991

Low-frequency respiratory system resistance in the normal dog during mechanical ventilation.

The low-frequency resistances of the respiratory system, lung, and chest wall were investigated in four anesthetized paralyzed dogs mechanically ventilated at various frequencies between 0.08 and 0.83 Hz. The resistances were calculated by three different methods: 1) as the real part of the complex impedance obtained from regular ventilation data, 2) as the effective resistance of a two-compartment model fitted to the same data, and 3) as the resistance of a single-compartment model fitted to data obtained during sinusoidal ventilation at various frequencies. Alveolar pressures were measured by a closed-chest alveolar capsule technique and afforded a direct measure of airways resistance. All three resistance estimates were very similar and decreased markedly with frequency between 0 and 1 Hz. The real part of lung impedance at the higher frequencies investigated (around 5 Hz) closely approximated airways resistance, as predicted by the eight-parameter viscoelastic model of respiratory mechanics proposed by Bates et al. (J. Appl. Physiol. 67:2276-2285, 1989).

Airway Resistance↗
PubMed1991

Effects of volume history and vagotomy on pulmonary and chest wall mechanics in cats.

Using the technique of rapid airway occlusion during constant-flow inflation, we studied the effects of inflation volume, different baseline tidal volumes (10, 20, and 30 ml/kg), and vagotomy on the resistive and elastic properties of the lungs and chest wall in six anesthetized tracheotomized paralyzed mechanically ventilated cats. Before vagotomy, airway resistance decreased significantly with increasing inflation volume at all baseline tidal volumes. At any given inflation volume, airway resistance decreased with increasing baseline tidal volume. After vagotomy, airway resistance decreased markedly and was no longer affected by baseline tidal volume. Prevagotomy, pulmonary tissue resistance increased progressively with increasing lung volume and was not affected by baseline tidal volume. Pulmonary tissue resistance decreased postvagotomy. Chest wall tissue resistance increased during lung inflation but was not affected by either baseline tidal volume or vagotomy. The static volume-pressure relationships of the lungs and chest wall were not affected by either baseline tidal volume or vagotomy. The data were interpreted in terms of a linear viscoelastic model of the respiratory system (J. Appl. Physiol. 67: 2276-2285, 1989).

Animals↗
PubMed1991

[Voiding disturbance in elderly males examined by prostate mass screening. Gunma Urological Oncology Study Group].

Information about voiding disturbance was obtained from 34,140 elderly males in Gunma Aged Club Association (Q group) through a questionnaire and from 8,129 males by prostate mass screening for prostate disease (MS group) as to: (1) the characteristics of the subjects examined by the mass screening, (2) the relationship between the voiding disturbance and aging and (3) the frequency of voiding disturbance in the normal elderly males. In MS group, the percentage of young subjects, especially less than 60 years old, who complained voiding disturbance was higher than the expected percentage on the assumption that it increases with aging. The percentage of voiding disturbance in these young subjects was also higher than that of males in the same decade in Q group. In their past and present history, the percentage of benign prostatic hypertrophy (BPH) in these young subjects was higher than the expected percentage on the assumption that the incidence of BPH increases with aging. Judging from these results, it was estimated that they were not satisfied with the medical care by which they were treated or were being treated, and they received this mass screening to obtain consultation for their complains. Loss of the force was related with the prostate size estimated by digital rectal examination but not with aging. However, nocturia was well related with aging but not with the prostate size. Hesitancy, strain and dribbling were not apparently related with either the prostate size or aging. It was demonstrated that frequency of nocturia was 0 to 1 in less than 60 years old normal males, 0 to 2 in 60 to 79 years old ones and 0 to 3 in over 80 years old ones. The other symptoms studied in each decade were also analyzed and discussed.

Aged↗
PubMed1990

Pharmacology of fludarabine phosphate after a phase I/II trial by a loading bolus and continuous infusion in pediatric patients.

Fludarabine phosphate is a nucleotide analogue of adenine arabinoside with antitumor activity in murine and human lymphoid malignancies; it has occasional, unpredictable neurotoxicity after high dose bolus injections in adults. To avoid this toxicity, we studied a loading dose plus 5-day continuous infusion in 47 evaluable pediatric patients. Dose limiting myelosuppression was seen in children with solid tumors after a loading dose of 8 mg/m2 followed by 23.5 mg/m2/day for 5 days. In children with leukemia, no dose limiting toxicity was seen at dose level 6, consisting of a loading dose of 10 mg/m2 and an infusion of 30.5 mg/m2/day for 5 days. One complete and 3 partial remissions were seen in 26 evaluable children with acute lymphoblastic leukemia. 9-beta-D-arabinofuranosyl-2-fluoroadenine plasma concentrations and the area under the moment curve increased linearly with dose. The terminal half-life was similar, while the total body clearance was shorter than that reported for adults receiving bolus or continuous doses. Lymphoblasts isolated from 2 patients during fludarabine phosphate (9-beta-D-arabinofuranosyl-2-fluoroadenine) treatment increased their ability to convert 1-beta-D-arabinofuranosylcytosine to 1-beta-D-arabinofuranosylcytosine 5'-triphosphate by more than 10-fold. The antileukemic activity of 9-beta-D-arabinofuranosyl-2-fluoroadenine 5'-phosphate and its ability to alter the metabolism of 1-beta-D-arabinofuranosylcytosine indicate that timed combinations of these 2 agents should be tested.

Antimetabolites, Antineoplastic↗
PubMed1990

Microscopic incipient hepatocellular carcinoma found incidentally in a routine liver biopsy specimen.

A microscopic atypical focus suggestive of hepatocellular carcinoma is reported. The lesion, 0.3 mm in diameter, was found by chance in a liver biopsy specimen taken from a cirrhotic patient; it was characterized histologically by cytoplasmic basophilia, hypercellularity (high nucleus-to-cell ratio) and microacinar structures. The reticulin framework of the focus was relatively sparse compared with the surrounding noncancerous area. The focus had developed in a regenerative nodule apparently no different from other regenerative nodules of the cirrhosis and showed no accompanying preneoplastic lesion such as adenomatous hyperplasia. A thorough search for the primary lesion, including ultrasonographic imaging and superselective hepatic arteriography, demonstrated no mass lesion in the liver. Therefore, the lesion may have been an incipient de novo hepatocellular carcinoma, and this may be the first report of such a lesion discovered in a biopsy sample.

Adult↗
PubMed1990

Enhancing effect of S-(1,2-dicarboxyethyl)glutathione on epidermal growth factor-stimulated DNA synthesis in primary cultures of adult rat hepatocytes.

A tripeptide S-(1,2-dicarboxyethyl)glutathione (DCE-GS) has been reported to be present in the lens, liver, and heart. Effects of DCE-GS and its derivatives and analogues on hepatocyte deoxyribonucleic acid (DNA) synthesis were examined using primary cultures of adult-rat hepatocytes. DCE-GS alone had no effect on DNA synthesis of hepatocytes. However, when DCE-GS was added with epidermal growth factor (EGF), the tripeptide effectively enhanced EGF-stimulated DNA synthesis of hepatocytes under the culture conditions of low cell density, but not high cell density. On the other hand, some esters and amides of DCE-GS and DCE-GS analogues showed a suppressive effect on DNA synthesis of hepatocytes in the absence of EGF. The derivatives and analogues together with EGF had no effect or rather a suppressive effect on stimulation of hepatocyte DNA synthesis by EGF. Therefore, the two carboxy groups in the substituent probably play an important role in the stimulative activity of DCE-GS. In addition, it seems likely that one of in vivo physiological roles of DCE-GS is related to liver regeneration.

Animals↗
PubMed1990

Influence of liver tumor promoters and structurally related chemicals on survival of normal adult rat hepatocytes in primary culture.

The influence of four liver tumor promoters and two structurally related chemicals (non-promoters) on survival of normal adult rat hepatocytes was examined in primary culture. Of the four promoters, butylated hydroxytoluene (BHT), dichlorodiphenyltrichloroethane (DDT), barbital sodium and phenobarbital sodium, only phenobarbital efficiently prolonged the hepatocyte survival and maintained the morphological features of the cells. Both BHT and DDT were toxic to hepatocytes within the dose ranges tested. Barbital was also ineffective for maintenance of primary cultured hepatocytes but not toxic to the cells. Of the two non-promoters, barbituric acid and amobarbital, barbituric acid also showed no maintenance effect on hepatocytes. However, amobarbital resembled phenobarbital in its effect on the maintenance of hepatocytes in primary culture. DNA synthesis of primary cultured hepatocytes was severely suppressed by phenobarbital in a dose-dependent manner. The results clearly show that the ability to support long-term survival of primary cultured hepatocytes is a common property of some barbiturates but not of liver tumor promoters, and that the maintenance of hepatocytes by phenobarbital is not due to a counterbalance of stimulated proliferation and death of the cells.

Animals↗
PubMed1990

Synthesis and biological activity of (22E,25R)- and (22,25S)-22-dehydro- 1 alpha,25-dihydroxy-26-methylvitamin D3.

Both 25-epimers of (22E)-22-dehydro-1 alpha,25-dihydroxy-26-methylvitamin D3 [22-dehydro-26-methyl-1,25-(OH)2D3] were synthesized. The biological activity of these compounds was tested in binding affinity to chick intestinal receptor protein of 1 alpha,25-dihydroxy-vitamin D3 [1,25-(OH)2D3] and in stimulating for intestinal calcium transport and bone calcium mobilization with vitamin D-deficient rats. The relative potency of (25R)- and (25S)-22-dehydro-26-homo-1,25-(OH)2D3 and 1,25-(OH)2D3 in competing for the intestinal cytosolic binding was 1.7:1.5:1. A similar order of activity was observed on intestinal calcium transport and bone calcium mobilization. In the ability for stimulation of intestinal calcium transport, (25R)- and (25S)-22-dehydro-26-methyl-1,25-(OH)2D3 were about 3.6 and 2.1 times as active as 1,25-(OH)2D3, respectively. In bone calcium mobilization tests, (25R)- and (25S)-22-dehydro-26-methyl-1,25-(OH)2D3 were estimated to be 2.2 and 1.6 times as potent as 1,25-(OH)2D3, respectively.

Animals↗
PubMed1990

The significance of erythrocyte sedimentation rate as a prognostic factor for patients with prostate cancer: Gunma Urological Oncology Study Group investigation.

The Gunma Urological Oncology Study Group has performed a multivariate statistical analysis of prognostic factors based on 353 patients with prostate cancer diagnosed between 1974 and 1984. This paper discusses the prognostic significance of erythrocyte sedimentation rate (ESR) in these patients with prostate cancer. Based on three ranges (less than 20, greater than 20- less than 50, greater than 50 mm/h) of ESR, a significant difference of survival rates among the patients was found by means of univariate analysis. ESR apparently includes components which represent anemia or infection. Hemoglobin, frequently used as a prognostic factor, was compared with ESR by means of multivariate analysis, and ESR was found to be a more useful prognostic factor than hemoglobin. Moreover ESR showed the highest partial coefficient value among the items studied (clinical stage, pathological differentiation, age, acid phosphatase, gait disturbance). It seems that ESR includes not only anemia and infection components but also provides a clue to the degree of bone metastasis or the degree of prostate cancer progression.

Acid Phosphatase↗
PubMed1990

Quasi-static pressure-volume hysteresis in the canine respiratory system in vivo.

We investigated the quasi-static pressure-volume (P-V) hysteresis of the normal canine lung in vivo by performing 15-s flow interruptions at various points throughout the breathing cycle in mechanically ventilated anesthetized paralyzed dogs. By measuring the transpulmonary pressure (Ptp) at 5 s after each interruption, we built up a quasi-static P-V loop of the lungs. We found, however, that the area of the loop was significantly smaller (by a factor of 4-6) than has been reported by others for the isolated canine lung. We also found the hysteresis loop area of the chest wall to be of similar magnitude. If we measured Ptp 10-15 s after interruption, we found it always decreased at a rate expected to result from continuing gas exchange in the lungs. We conclude that 1) the areas of the quasi-static P-V loop in vivo for the total respiratory system, as well as the lungs and chest wall separately, are significantly smaller than has been reported previously for isolated lungs and 2) continuing gas exchange in the lungs places a lower limit on the frequencies (equivalent to flow interruptions of greater than 5- to 7-s duration) at which the P-flow-V behavior of the lungs in vivo can be considered in purely mechanical terms.

Animals↗
PubMed1990

High-frequency characteristics of respiratory mechanics determined by flow interruption.

When flow at the airway opening is suddenly interrupted, the pressure measured just behind the point of interruption generally exhibits certain characteristic features, including some rapid and highly damped oscillations immediately after the interruption. It has previously been assumed that these oscillations reflect ringing of central airways gas. In the present study we investigated this hypothesis by performing flow interruptions during relaxed expiration in normal, tracheostomized, anesthetized, paralyzed dogs while the lungs were filled with four different gas mixtures having widely varying physical properties. We found that the power spectrum of the oscillations exhibited two peaks. The larger peak was centered about a frequency that varied approximately linearly with the inverse of the square root of the gas density. The other peak was smaller and was located at approximately 70 Hz with all gas mixtures. The area under the power spectrum of the ringing varied approximately linearly with the density of the gas mixture. These results indicate that the larger peak in the power spectrum reflects the quarter-wave resonance of the gas in the airways, whereas the smaller peak reflects a tissue resonance.

Animals↗
PubMed1990

Effects of laminin and collagen type I on the morphology and secretion of proteins in human hepatoblastoma and hepatoma cell lines.

The effects of laminin (LAM) and collagen type I (C-I) on human hepatoblastoma (HuH-6) and hepatoma (HuH-7) cell lines were investigated. C-I was superior to LAM in supporting the attachment of the cells, especially of HuH-6, to plastic surfaces. No effect of LAM and C-I on cellular morphology was recognizable by phase contrast microscopy. By scanning electron microscopy (SEM), much more microvilli were found on the cell surface of HuH-6 on LAM substrate than on C-I substrate. In HuH-7 cells, however, these microvilli were rarely found on either LAM substrate or C-I substrate. The gel profile of the proteins secreted by HuH-6 and HuH-7 cells was not affected by the culture substrate except for the major band, though the amount of alpha-fetoprotein (AFP) secreted was larger when the cells were cultured on LAM substrate than on C-I substrate. These results indicate that the ability of LAM or C-I to enhance attachment is different from that to enhance AFP production or microvilli expression in HuH-6 cells and probably in HuH-7 cells.

Carcinoma, Hepatocellular↗
PubMed1990

Selection of medium for serum-free primary culture of adult rat hepatocytes.

To select a suitable medium for serum-free primary culture of adult rat hepatocytes, ten commercially-available synthetic media were compared for their ability to maintain the cells under serum-free and serum-supplemented conditions with special reference to attachment, survival and albumin secretion. It was found that Williams' medium E and DM-160 medium were the best among the ten media for maintaining hepatocytes under serum-free conditions in primary culture.

Albumins↗