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Biomedical subjects

R Sato

Publications and source records attributed to R Sato.

At least 271 records · Page 15Linked to original sources
PubMed1990

[Studies on respiratory infections in primary care clinic (III). Distribution of bacteria isolated from patients with respiratory infections visiting 21 private clinics in the Tohoku District of Japan].

The bacteriology of the isolates from the throat swab and the sputum respectively of 2,539 patients with respiratory infections visiting 21 private clinics in Tohoku district of Japan during the period from January to April in 1989 was documented. Of the 2,539 patients, 1,694 had an acute upper respiratory infection, 609 had acute bronchitis, 46 had acute pneumonia, 84 had acute exacerbation of chronic respiratory infections and 106 had respiratory infections without diagnosis registered. 1887 (74.3%) strains of potential pathogens were recovered from 1507 (59.4%) of the 2539 cases. The rate of recovery of potential pathogens was very high in patients of the younger age. These patients had elevated body-temperature. There were statistically significant differences in recovery rate when classified by diagnosis, prefecture and the period of investigation. Of the 1,887 strains, 996 (52.8%) were gram-positive and 891 (47.2%) were gram-negative bacteria. The rate of recovery of gram-negative bacteria was high in patients who were less than 10 years old and more than 51 years old, in patients with pneumonia and chronic respiratory infections, and in patients with fever. Of the 1,887 strains, those which exceeded 100 were Staphylococcus aureus (481 strains), Haemophilus influenzae (340 strains), Streptococcus pneumoniae (329 strains), Streptococcus pyogenes (117 strains) and Acinetobacter spp. (100 strains). Species other than those mentioned above had less than 100 strains. In this group there were 39 strains of Branhamella catarrhalis, 32 strains of Escherichia coli, 97 strains of Klebsiella spp., 40 strains of Enterobacter spp., 25 strains of Serratia spp., 12 strains of Pseudomonas aeruginosa and 43 strains of Pseudomonas putida. There was a remarkable difference in recovery rate of each species when classified by diagnosis, age class, prefecture and the period of investigation, respectively. The above results indicated that gram-positive bacteria are more frequent than gram-negative bacteria, that enterobacteriaceae and glucose-non-fermentative gram-negative bacteria are only rarely found in primary care clinics, and that the bacteriology in primary care clinic is different from that of medical school-affiliated hospitals.

Adolescent↗
PubMed1990

[Studies on respiratory infections in primary care clinic (IV). Antibiotic sensitivity of bacteria isolated from patients with respiratory infections visiting 21 private clinics in the Tohoku District of Japan].

We determined the MICs of ampicillin, methicillin, cefaclor, cefixime, cefteram, ofloxacin and ciprofloxacin against a total of 1,448 strains from 11 species: 464 strains of Staphylococcus aureus, 306 strains of Streptococcus pneumoniae, 114 strains of Streptococcus pyogenes, 37 strains of Branhamella catarrhalis, 329 strains of Haemophilus influenzae, 32 strains of Escherichia coli, 66 strains of Klebsiella pneumoniae, 26 strains of Enterobacter cloacae, 20 strains of Serratia marcescens, 12 strains of Pseudomonas aeruginosa and 42 strains of Acinetobacter calcoaceticus, isolated from the throat swab and the sputum of 2,539 patients with respiratory infections who visited 21 private clinics in Tohoku district of Japan during the period from January to April in 1989. Ciprofloxacin and ofloxacin were more active against S. aureus, B. catarrhalis, P. aeruginosa and A. calcoaceticus than other antibiotics. Ampicillin and cefteram were more active against S. pneumoniae and S. pyogenes than other antibiotics. New-quinolones and cephems of new-generation were active against H. influenzae, E. coli, K. pneumoniae, E. cloacae and S. marcescens. Of 30 strains of S. aureus which were resistant (MIC greater than or equal to 12.5 micrograms/ml) to ampicillin, only one strain was resistant (MIC greater than or equal to 12.5 micrograms/ml) to methicillin. Twenty strains (6.5%) of S. pneumoniae and 49 strains (14.9%) of H. influenzae were resistant (MIC greater than or equal to 1.56 micrograms/ml) to ampicillin. Of 101 strains of H. influenzae of which their beta-lactamase activity was determined by Nitrocephin-method, 27 (26.7%) were beta-lactamase-positive strains. The above results indicated that MRSA is only rarely found in primary care clinics but the incidence of ampicillin-resistant H. influenzae in primary care clinics is almost the same as that of the intensive care clinic, i.e. medical school-affiliated hospitals. Therefore caution should be exercised as regards antibiotic resistance of the causative organism even in primary care clinics.

Ambulatory Care Facilities↗
PubMed1990

Excess purine degradation caused by an imbalance in the supply of adenosine triphosphate in patients with congestive heart failure.

To evaluate purine degradation in patients with congestive heart failure concentrations of serum hypoxanthine, lactate, and noradrenaline were measured before and after submaximal treadmill exercise in 12 patients with chronic congestive heart failure and nine healthy volunteers. In four patients the concentration of hypoxanthine was significantly higher than in the controls or in the remaining eight patients with congestive heart failure. Venous lactate and noradrenaline in the four patients with high concentrations of hypoxanthine were also significantly higher than those in the eight patients with normal concentrations of hypoxanthine. Patients who responded normally were also more likely to have been treated with vasodilators and angiotensin converting enzyme inhibitors. Exercise induced arrhythmias were more common in the patients with high concentrations of hypoxanthine. These results suggest that the excess purine degradation in patients with congestive heart failure might be the result of a "relative" disturbance in the supply of adenosine triphosphate caused by the shift of cellular metabolism from aerobic glycolysis to anaerobic glycolysis during submaximal exercise and that hypoxanthine (a substrate for xanthine oxidase and a source of free radicals) was increased after submaximal exercise in some patients with congestive heart failure.

Adenosine Triphosphate↗
PubMed1990

Acetylcholine-sensitive potassium channels in human atrial myocytes.

Single channel recording techniques were used to study acetylcholine (ACh)-sensitive K+ channel activity in human atrial myocytes isolated from specimens obtained during corrective cardiac surgery. Under conditions of cell-attached patch, the presence of ACh in the patch pipette activated K+ channels. Single channel activity occurred in periodic bursts. The channels exhibited a slope conductance of 46 +/- 2 pS inwardly (means +/- SD, n = 4). During a burst, both open and closed time histograms were fitted by a single exponential curve, suggesting the existence of one open and one closed state during a burst. Open probability increased directly with ACh concentration without affecting open time. The channel could be activated by GTP and guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) (in the presence and absence of ACh in the pipette, respectively). Slope conductance, the response to GTP and GTP gamma S, and the independence of activation from Ca2+ were similar to those for other species. In contrast, sensitivity to ACh appeared diminished compared with frog atrial myocytes.

Acetylcholine↗
PubMed1990

Early increase in K+ conductance during metabolic inhibition by cyanide in guinea pig ventricular myocytes.

The underlying mechanism of the early increase in K+ conductance during metabolic inhibition was examined by the whole-cell patch clamp technique. To inhibit oxidative phosphorylation, cyanide (0.1-1.0 mM) was superfused to enzymatically isolated guinea pig ventricular myocytes. The increase in the outward K+ current during the metabolic inhibition consisted of at least two components; one was a gradual and small increase which appeared within 5 min, and the other was a subsequent sudden and large increase occurring 17.8 min on average after cyanide application at a concentration of 0.1 mM. The earlier component of the cyanide-sensitive current was examined by the square pulse method. The current had a reversal potential of -76.0 mV and an inward-rectifying property. When cyanide (0.1 mM) was applied for 10-12 min, the chord conductance of the inward rectifier K+ current (IK1) was significantly increased and its voltage relation was shifted to hyperpolarizing direction (-2.3 mV). The cyanide could not induce an outward current in K(+)-free ionic condition or in the presence of extracellular Ba2+ (2 mM), a blocker of the IK1. However, the outward current even appeared in the presence of 5 mM ATP in the perfused solution in pipette, while it attenuated when intracellular pH was buffered with 50 mM HEPES in the pipette solution. These observations suggest that the early increase in K+ conductance during the metabolic inhibition is due to the augmented IK1 conductance and not due to the induction of ATP-sensitive K+ current. The increase in the K+ conductance may be caused by the intracellular pH change, probably through intracellular metabolic acidosis by the inhibited oxidative phosphorylation.

Adenosine Triphosphate↗
PubMed1990

[Colorimetric study of dental porcelain. The characteristics of the absorption and scattering coefficients].

Recently, the demand for a more natural and harmonious color of porcelain-fused-to-metal restoration is on the increase due to the recent rise in esthetic values among the patients. However, the usual methodology of shade taking, color transmission, and color evaluation is not so precise. We have thus tried to resolve this problem with the aid of a computer color matching system for the purpose of reproducing the natural and harmonious color of porcelain-fused-to-metal restoration. To obtain the colorimetric and optical fundamental data of dental porcelains, we analyzed its absorption and scattering coefficients by using a spectrophotometer. It was concluded that there was a high positive correlation between the absorption and scattering coefficient to porcelain thickness in both the dentin and enamel porcelain layers. As the wavelength increased, the absorption coefficient tended to decrease and the scattering coefficient tended to increase. From this experiment, it became possible to determine the absorption and scattering coefficient of the dentin and enamel porcelain layers of any shade and thickness.

Color↗
PubMed1990

Plasma osteocalcin in preparturient and postparturient cows: correlation with plasma 1,25-dihydroxyvitamin D, calcium, and inorganic phosphorus.

The purpose of the present study was to determine changes of plasma osteocalcin levels in periparturient cows and to examine the correlation of plasma osteocalcin level with that of 1,25-dihydroxyvitamin D, Ca, and inorganic P. Five Holstein-Friesian cows, aged 3 to 5 yr, were used from 5 d before to 15 d after calving. Concentration (mean +/- SE) of plasma osteocalcin decreased rapidly from d 1 prepartum, reached a low of 8.0 +/- 3.0 ng/ml at d 1 postpartum, and then recovered gradually to 17.8 +/- 3.8 ng/ml at 15 d after calving. In contrast, the concentration of plasma 1,25-dihydroxyvitamin D increased from calving to 3 d postpartum. Plasma concentrations of osteocalcin did not correlate significantly with those of 1,25-dihydroxyvitamin D, but it was significantly proportional to that of Ca and inorganic P. It is suggested that osteoblast function is depressed by a number of factors around the time of parturition.

Animals↗
PubMed1990

[A study on the proximate determinants of fertility decline in China].

To study the biological and behavioral process of the recent drastic fertility decline in China, the authors reviewed relating factors (proximate determinants) and applied the Bongaarts model to the population of China for the years 1971 and 1981, during which the fertility rate dropped most rapidly and substantial population control policies were performed. By application of the model, the decrease of TFR of 2.78 between 1971 and 1981 was estimated to be contributed by widespread of contraception (68%), later marriage (49%), and increase of induced abortion (28%), through shortening of the length of postpartum breastfeeding showed negative effects (-32%), on the assumption that local data could be substituted for some national data. Compared with other countries, China was characterized by coexistence of strong fertility-inhibiting effects of nonmarriage, contraception, induced abortion, and relatively strong fertility-inhibiting effects of breastfeeding. It strongly suggested that the fertility transition in China was realized by powerful population policies in the context of insufficient socioeconomic development to lead to the transition.

Abortion, Induced↗
PubMed1990

[A case of colony stimulating factor (CSF) producing gastric carcinoma].

A gastric carcinoma associated with marked leukocytosis is reported. The case involved a 70-year-old male who was admitted to Akita Kumiai General Hospital because of general fatigue and vertigo in October, 1989. A palpable, hard, uneven mass was found in the epigastrium. Further, an upper gastrointestinal series revealed a large filling defect in the gastric body. Also, an endoscopic examination disclosed an uneven mass, and specimens that were biopsied showed an adenocarcinoma. The white blood cell (WBC) count was 45,800/microliter and had a 96% presence of neutrophils, and an examination of the bone marrow showed excessive myeloid hyperplasia. The WBC gradually increased, reaching up to 67,800/microliter. Finally, an EIA assay of the serum colony stimulating factor (CSF) disclosed a marked increase. After a gastrectomy, the WBC promptly decreased to the normal range and the CSF activity in a supernatant of a tumor-cell-conditioned medium showed a higher value. Thus, this tumor was diagnosed as being a CSF-producing gastric carcinoma.

Adenocarcinoma↗
PubMed1990

Budding process and maturation of human immunodeficiency virus examined by means of pre- and post-embedding immunocolloidal gold electron microscopy.

The techniques of pre- and post-embedding immunocolloidal gold electron microscopy were tested for their usefulness for analyzing the morphogenesis of human immunodeficiency virus (HIV) strain LAV employing U-937 cells persistently infected with the virus (U-937/LAV). By both techniques the following results were obtained. (1) Budding process was restricted to a localized area at the membrane adjacent to the Golgi apparatus. (2) The distribution of viral envelope antigens was restricted to the electron-dense crescent structures on the cell surface. (3) Virions released from the cells could be classified mainly into 2 categories: virions with doughnut-shaped cores or with conical cores at the center of the particles. And p24 proteins localized on the thick electron-dense cores of both types. These findings support the idea that pre- and post-embedding immunogold electron microscopy is very useful for studying the morphogenesis of viruses.

HIV↗
PubMed1989

[Reference line for delineation of the intraparotid facial nerve on MRI].

Exact identification of intraparotid facial nerve is important in surgical management of parotid tumors. To delineate the intraparotid facial nerve on MRI, we proposed a new reference line, which was drawn between the inferior margin of the bone marrow of the atlas and superior margin of the bone marrow of the mandible on midsagittal section. This reference line crossed with orbito-meatal line at the mean angle of 37 +/- 3 degrees. By scanning parallel to this line, intraparotid facial nerve was clearly identified in 19 (79%) of 24 normal parotid glands.

Facial Nerve↗
PubMed1989

The molecular structure of adrenal medulla kinesin.

The molecular structure of bovine adrenal kinesin was studied by electron microscopy using the low-angle rotary shadowing technique. Adrenal kinesin exhibited either a folded or an extended configuration; the ratio of the two is dependent on the salt concentration. Almost all adrenal kinesin molecules were folded in a low-ionic solution, and the ratio of extended molecules increased to 40-50% in a solution containing 1 M ammonium acetate. Kinesin in the extended configuration displayed a rod-shaped structure with a mean length of about 80 nm. The morphologies of the ends were different; one end was composed of two globular particles, similar to the two-headed structure of myosin, while the other end had a more ill-defined structure, appearing either as a globular particle, an aggregate of two to four small granules, or a frayed, fan-like structure. The folded kinesin molecule possessed a hinge region in the middle of the rod, at about 32 nm from the neck of the two heads. In our preparations, the majority of adrenal kinesin molecules were folded at physiological salt concentrations. Adrenal kinesin bound to microtubules in the presence of adenylyl imidodiphosphate (AMP-PNP) also displayed a folded morphology.

Acetates↗
PubMed1989

Human scalp hair as evidence of individual dosage history of haloperidol: method and retrospective study.

Hair samples and morning pre-dose plasma were collected from 40 patients who had received fixed daily doses of haloperidol for more than four months and whose compliance was good. After washing, 1 to 2 cm-long portions nearest to the roots of 2 to 3 strands of hair were completely dissolved in 2.5N NaOH. Haloperidol in that sample or alkalinised plasma was extracted and measured by RIA. Haloperidol concentrations in hair correlated well both with the trough concentration in plasma at steady-state (r = 0.772, n = 39) and with the daily dose (r = 0.555, n = 40). Another keratinized tissue, nail, was also collected from 20 of the 40 patients and the haloperidol level was compared with that in hair. The former was only about 4.3% of the latter and was significantly correlated only with the daily dose (r = 0.525, n = 20). Hair from 10 other patients in whom the dosage of haloperidol had been changed within a few months prior to sampling the hair was cut into 0.5 or 1 cm-long portions from the roots and the drug concentration in each portion was measured. If hairs were assumed to grow at 1 cm/month, a history of individual dosage could be deduced in 9 of the 10 patients from the distribution of drug level along the length of the hair. The results suggest that human scalp hair could serve as a useful tool for monitoring individual dosage history over several months, or in demonstrating exposure or non-exposure of a patient to a drug.

Adult↗
PubMed1989

Hypouricaemia with acute viral hepatitis.

We report five female cases of hypouricaemia accompanied by acute viral hepatitis (serum urate 101 +/- 12 mumol/l, mean +/- SD). Their urate clearance was increased to 14.2 +/- 3.4 ml/min during hyperbilirubinaemia but 24-h urate excretion was not elevated (2.09 +/- 0.64 mmol/24 h). No other renal tubular abnormalities were detected. Comparing urate metabolism with that of four cases of inborn renal hypouricaemia, the degree of uricosuria was lower. One patient showed elevation of serum and urinary oxypurine, which normalized with return of a normal blood uric acid level. In all cases, the serum urate returned to normal after improvement of liver function. We suggest that renal uricosuria due to an isolated renal defect of urate transport might contribute to hypouricaemia in these cases but that inhibition of xanthine oxidase activity might also contribute to this phenomenon.

Acute Disease↗
PubMed1989

Prediction of individual dosage requirements for lignocaine: a validation study for Bayesian forecasting in Japanese patients.

The performance of the Bayesian feedback method for predicting lignocaine dosage developed by Vozeh et al. was evaluated in 53 Japanese patients, treated for either suppression or prophylaxis of ventricular arrhythmias, with respect to accuracy, precision, efficiency, and safety. The lignocaine serum concentrations at 12 h (C12) and 24 h (C24) after continuous infusion was started were predicted and compared retrospectively using the early concentration at 2-4 h (C2-4). The mean of the prediction error (PE) and the root mean-squared error (RMSE) were used as a measure of accuracy and precision. The 95% confidence interval of PE for C12 included zero, but those of PE for C24, whether C2-4 was used alone or in combination with C12, were less than zero, meaning that the prediction of C24 was significantly biased. The RMSE for C12 (13.2%) was less than that for C24 (16.2%), but the difference was not statistically significant. The fraction of measurements lying within the statistically approximate 68% prediction interval (+/- 1 SD) was used to evaluate the estimate of the SD of prediction. The fraction of measurements inside the prediction interval was significantly larger than the expected 68% for both C12 and C24 (p less than 0.05), showing that the estimate of the size of the PE is biased on the safer side. The clinical effects of lignocaine were also evaluated from the viewpoints of suppression of number of ventricular premature beats, prevention of more severe grades of arrhythmias, and toxicity. At least the appearance of toxicity, which four patients exhibited, was related to the lignocaine serum concentration (greater than 6 micrograms/ml).

Adult↗
PubMed1989

Human scalp hair as evidence of individual dosage history of haloperidol: prospective study.

The concentration of haloperidol in hair was measured by radioimmunoassay after hairs were dissolved in 2.5 N NaOH solution and the drug was extracted. In patients to whom haloperidol had been administered at fixed daily doses for more than 1 month, and in whom therapy had been just discontinued (group A, n = 5) or the doses cut to half (group B, n = 3), hairs were collected when the dose was changed and at 1 and 2 or 3 months thereafter. A few strands of hair collected on each occasion were cut into 1-cm-long portions from the roots, and the haloperidol concentration was measured in each portion. When hairs were assumed to grow at a rate of 1-1.5 cm/month, the portion of hair that reflected the change of dose was observed to move upward along the hair length in all patients of group A. However, these phenomena were less obvious in group B. These results indicate that at the least, hair could serve as an indicator of individual exposure or nonexposure to haloperidol and could yield retrospective information. In rats whose hairs had been removed by plucking from an area on the back, either saline or 1 mg/kg of haloperidol (i.p., b.i.d.) was administered for 2 weeks (first period), followed by 0, 0.5, 1, or 2 mg/kg b.i.d. for the subsequent 2 weeks (second period). At the end of each period, hairs that had grown in the plucked area were collected. Within-groups, haloperidol levels in hairs collected at the end of each period corresponded to the doses given.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Elevated expression of basic fibroblast growth factor messenger ribonucleic acid in acoustic neuromas.

Human tumors were analyzed for the presence of mRNA coding for basic fibroblast growth factor (basic FGF). Basic FGF transcript levels were consistently elevated in schwannoma samples (five acoustic neuromas and two spinal schwannomas) ranging from 9- to 22-fold higher than the average level of expression in four benign meningioma samples. Acidic extracts of acoustic neuromas contained a potent mitogen which bound to heparin-Sepharose, eluted at 2 M NaCl, and cross-reacted with an N-terminal specific anti-basic FGF antiserum. The present findings indicate that basic FGF appears to be the major heparin-binding endothelial cell mitogen in acoustic neuromas. Southern restriction analysis revealed no evidence of amplification or rearrangement of the gene for basic FGF in schwannomas or in the astrocytoma cell line U87-MG. These findings demonstrate a tumor-specific elevation in basic FGF transcript levels in tumors of Schwann cell origin and suggest that increased transcription or stabilization of basic FGF mRNA may play an autocrine role in the development and progression of these tumors.

Blotting, Southern↗