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Biomedical subjects

Y Shimada

Publications and source records attributed to Y Shimada.

At least 559 records · Page 31Linked to original sources
PubMed1990

Effects of antiarrhythmic agents classified as class III group on ischaemia-induced myocardial damage in canine hearts.

1. The cardioprotective effects of antiarrhythmic agents classified as class III, amiodarone, sotalol and E-4031, were investigated in anaesthetized dogs. 2. The left anterior descending coronary artery was occluded for 2 h. 3. Heart mitochondria were prepared from both the ischaemic and non-ischaemic areas, and their function was estimated polarographically. 4. Activities of the lysosomal enzymes, N-acetyl-beta-glucosaminidase and beta-glucuronidase, were measured in each fraction. 5. Two hour occlusion induced ventricular arrhythmias, and amiodarone, sotalol and E-4031 greatly suppressed the development of arrhythmias. 6. Amiodarone, sotalol and E-4031 significantly protected mitochondria against ischaemia, and prevented ischaemia-induced leakage of lysosomal enzymes. 7. Antiarrhythmic agents classified as class III show cardioprotective effects, which might participate in their antiarrhythmic effect.

Acetylglucosaminidase↗
PubMed1990

Effects of isoprothiolane and phytosterol on lipogenesis and lipolysis in adipocytes from rats of dietary fat necrosis.

To study effects of isoprothiolane and phytosterol on dietary fat necrosis, 3 groups of rats were fed hardened-tallow (HT) diet. Two groups of rats received either isoprothiolane (50 mg/kg) or phytosterol (20 mg/kg) orally once a day consecutively for 10 weeks. One group of rats received standard diet (CE-2) as a control. Fat necrotic lesions were observed in epididymal and perirenal adipose tissues from all rats in the 3 groups fed HT diet. Rats with fat necrosis were characterized by visceral type obesity and saturation in fatty acid composition of triglyceride in adipose tissue. The highest glucose conversion to total lipids was seen in adipocytes from the rats given phytosterol. There was no lipolytic response to epinephrine stimulation (1-100 microM) in adipocytes from the rats given only HT diet, while similar response of adipocytes from the 2 groups treated with either drug to those from the rats fed standard diet was observed. The levels of total saturated fatty acids of phospholipid in adipose tissue from the rats given either drug were lower than that of the rats given only HT diet. These data suggest that either drug alters fatty acid composition of phospholipid in fat cell membrane and enhances lipolysis of the cells.

Adipose Tissue↗
PubMed1990

Histological observations of canine cystic endometrial hyperplasia induced by intrauterine scratching.

Of eight mongrel bitches, the antimesometrial side of the nonpregnant left horn of the uterus at the pregnant or nonpregnant luteal phase was scratched with a Kirschner's wire. Cystic endometrial hyperplasia (CEH) was induced in seven of the eight bitches (87.5%). No difference in the incidence of CEH in the left horn was seen between the pregnant and the nonpregnant groups. Histological examinations showed CEH with a dilatation of the basal glands, resembling "Swiss cheese endometrium".

Animals↗
PubMed1990

[Efficacy and side effects of epidural opioids depending on the site of surgery].

We reported the requirement of supplemental analgesics following epidural opioids including Opial 5mg and 10mg, and morphine HCl 2.5mg, for 24 hours in postoperative period after surgery of body surface, and lower and upper abdominal surgeries. Incidence of their side effects was also observed. Opial contains 50% morphine HCl and other opioids such as codeine, thebaine, papaverine, and noscapine etc. After upper abdominal surgeries, patients required additional analgesics more frequently. Kinds and doses of opioids used, suggest that epidural administration of other opioids contained in Opial has some analgesic effect. After the surgery of body surface the opioid requirement may be influenced by the intraoperative anesthetic technics and the state of mind of the patient. Urinary retention was the most interesting side effect observed and our data suggest that papaverine contained in Opial may have favorable effect and morphine HCl may have adverse effects regarding its incidence.

Analgesia, Epidural↗
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

[Pharmacokinetics and clinical effects of cefdinir 5% fine granules in pediatrics].

Cefdinir (CFDN), a newly developed oral cephalosporin in 5% fine granular form, was administered to 10 boys at 1 hour before meal (in the fasting state) and concentrations of the drug in plasma and urine and its urinary recovery rates were determined. The subjects were divided into 2 groups of 5 boys each; one group received 3 mg/kg of CFDN, and the other, 6 mg/kg. To 6 of the 10 children the drug was administered in the two different dose levels using the cross-over method. To study clinical and bacteriological effects of this drug, a mean dose of 4.6 mg/kg t.i.d. was administered for 8 days on the average to 40 children with various infections; pharyngitis (4 cases), tonsillitis (2), acute bronchitis (2), pneumonia (8), scarlet fever (6), acute purulent otitis media (1), urinary tract infection (12), impetigo (2), phlegmon (1), lymphadenitis (1) and subcutaneous abscess (1). MICs were determined for 6 drugs including CFDN, cefaclor, cefixime (CFIX), methicillin, cloxacillin (MCIPC), amoxicillin (AMPC) against 13 strains of 6 species freshly isolated from children receiving CFDN. An inoculum size of 10(6) cfu/ml was used in the MIC-determinations. Adverse reactions and abnormal laboratory findings attributable to this drug were also examined in these patients. The results obtained are summarized as follows. 1. Mean plasma peak levels of CFDN were observed at 3 hours after administration in both the 3 mg/kg and 6 mg/kg groups with mean peak values of 0.68 and 1.35 micrograms/ml, respectively. Mean half-lives were 2.06 hours in the 3 mg/kg group and 1.61 hours in the 6 mg/kg group, and mean AUCs were 3.5 in the former and 6.5 micrograms.hr/ml in the latter. Thus, dose-response between the 2 doses was observed in plasma levels and AUCs. 2. To 3 patients, CFDN was given in the two different doses using the cross-over method. Mean plasma peak levels of CFDN were 0.71 and 1.31 micrograms/ml in the doses of 3 mg/kg and 6 mg/kg, respectively. Half-lives were 1.39-2.90 hours in the 3 mg/kg group and 1.21-1.48 hours in the 6 mg/kg group, with AUCs of 3.4-3.7 and 4.1-7.5 micrograms.hr/ml, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Oral↗
PubMed1990

[Pharmacokinetics and clinical studies of norfloxacin in the pediatric field].

Norfloxacin (NFLX) tablets with a potency of 50 mg/tablet or 100 mg/tablet were administered at doses of 1 to 4 tablets (1.5 to 6.1 mg/kg) orally 30 minutes before meals to 12 children with ages ranging from 8 years 9 months to 12 years 5 months, and serum/urinary NFLX levels and urinary recovery rates were determined. The drug sensitivity tests for NFLX and 10 other drugs were conducted against 128 strains of Shigella sonnei (10(6) CFU/ml) which had been isolated from pediatric patients with bacillary dysentery. In order to evaluate clinical and bacteriological effects of NFLX and its safety in the pediatric field, NFLX 50 mg tablets were administered t.i.d. (mean 8.3 mg/kg) for 5 days to 42 pediatric patients with bacillary dysentery. Similarly, this drug was administered in b.i.d. or t.i.d. (mean 6.7 mg/kg) for 4 days to 4 pediatric patients with urinary tract infections. The following results were obtained: 1. According to the dosage, the subjects were divided into 3 groups with dose levels 1.5-2.8 mg/kg, 3.1-4.7 mg/kg and 5.2-6.1 mg/kg. These groups had 5, 2 and 5 subjects, respectively. Mean serum drug concentrations for the 3 dosage groups were at peak levels of 0.27, 0.64 and 1.51 micrograms/ml at 4, 2 and 1 hour(s) after administration, respectively. Pharmacokinetic parameters for these dosage groups were as follows: Tmax values were 3.0, 3.0 and 1.2 hours; Cmax values were 0.32, 0.78 and 1.56 micrograms/ml; serum half-lives were 2.2, 2.4 and 2.3 hours; and AUCs were 1.65, 3.98 and 6.06 micrograms.hr/ml, respectively. Thus, dose-dependent responses were observed among the 3 dosage groups. 2. Mean peak urinary drug concentrations for the 3 dosage groups were 45.8, 109.2 and 215.1 micrograms/ml, respectively, and the peaks appeared 2-4 hours after administration. Mean recovery rates up to 8 hours after administration were 18.3%, 24.5% and 28.7%, respectively for the 3 dosages. 3. In a drug sensitivity test against 128 strains of S. sonnei, the most frequent MIC value of NFLX was 0.78 micrograms/ml against 65 strains, followed by 0.39 micrograms/ml for 56 strains. Together, these strains accounted for 94.5% of the strains tested. No resistant strain to this drug was observed and the antibacterial activity of this drug was second only to colistin, similar to that of ofloxacin, better than those of enoxacin and seven other drugs. 4. Clinical efficacy rate of NFLX against bacillary dysentery was 95.2% in 21 cases in which the evaluation was possible.(ABSTRACT TRUNCATED AT 400 WORDS)

Age Factors↗
PubMed1990

[Influence of cefodizime via intravenous bolus injection on human fecal flora].

Cefodizime (CDZM), a newly developed injectable cephem antibiotic, was given to 8 healthy male volunteers with ages 23-28 years (mean: 24 years) and body weights 54-73 kg (mean: 64 kg). 4 volunteers received 2 g b.i.d., intravenous infusion for 5 days, and 4 volunteers had 4 g b.i.d. for the same duration. We studied changes in bacterial flora and drug levels in feces, as well as changes in susceptibility of isolated microbes to CDZM, cefmetazole, cefotaxime (CTX) and cefoperazone. Adverse drug reactions and changes in laboratory findings were also investigated. The following results were obtained. 1. In fecal flora for the 2 g b.i.d. group, on day 3 of treatment Enterobacteriaceae were identified in only 2 of the 4 cases. Individual microbe counts decreased or fell below detection limit (10(2) cells/g) on day 3 of treatment. Colony forming units (CFUs) of Enterobacteriaceae on day 5 of treatment were similar to those on day 3. After the end of treatment, its CFUs increased. The mean CFU of Enterobacteriaceae on day 10 after the end of treatment increased to about the same level as before dosing. However, some microbes did not revert to pretreatment levels. Of other Gram-negative bacilli, Pseudomonas sp. increased in one case transiently on day 3 of treatment. After day 3 of treatment, its CFU decreased. Gram-positive microbes showed various changes. Mean CFU of yeast like organism (YLO) increased between day 3 of treatment and day 3 after the end of treatment and its mean CFU decreased on day 10 after the treatment. As for anaerobes, CFUs of Bacteroides fragilis group organisms and overall anaerobes showed no distinctive changes. Clostridium difficile were detected in two cases. In one case, C. difficile was noted at levels between 1.1 X 10(3) cells/g and 2.0 X 10(6) cells/g at the following sampling times: days 1 and 3 of treatment and days 3, 5, 10 and 20 after the end of treatment. In other case, it was noted at levels of 1.8 X 10(5) cells/g on day 20 after the end of treatment. D-1 toxin was detected in one case before dosing, and in three cases (the concentration of D-1 toxin was 250 ng/g or 500 ng/g) on day after treatment. Enterobacteriaceae in fecal flora of 4 cases given 4 g b.i.d. frequently decreased or fell below detection limit on days 3 and 5 of treatment and day 3 after the end of treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1990

Pneumocystis carinii infection in corticosteroid-treated cats.

Corticosteroids were administered to produce Pneumocystis carinii infection in cats. Six of 10 cats, injected intramuscularly for 97-141 days with 2 mg/cat twice weekly of betamethasone sodium phosphate, developed a light infection with P. carinii. Six of 7 cats, injected intramuscularly for 11-168 days with 10-25 mg/cat weekly of prednisolone acetate, also developed a light infection with P. carinii. There was no significant difference in the infection rate between the sexes and ages of the cats. Using Giemsa staining and Gomori's methenamine silver nitrate stain, P. carinii organisms were indistinguishable morphologically from human and rat P. carinii. The cysts and trophozoites were usually present singly or in small groups, and they always were adhering to the periphery of alveoli. The inflammatory changes were inconspicuous except for the fact that alveolar macrophages often were seen. Corticosteroid-treated cats should be useful in the study of experimental P. carinii infection. This is the first reported case of experimentally induced P. carinii infection in cats.

Animals↗
PubMed1990

Three-dimensional structure of intracellular membranous organelles in embryonic chick skeletal muscle cells in vitro revealed with scanning electron microscope.

Using the freeze-polishing and osmium-maceration procedures, the ultrastructure of intracellular membranous organelles in embryonic chick skeletal muscle cells in vitro was investigated three-dimensionally with the scanning electron microscope (SEM). T-system tubules followed a tortuous course and possessed many warts. Some of these tubules could be traced to the sarcolemma. The sarcoplasmic reticulum (SR) had elaborate structures of a hexagonal pattern. By comparing the SEM images with those of ultrathin sections of myotubes impregnated with ferritin particles, the distinction between the T-system and SR was confirmed. Late in the culture, these two intracellular membranous systems were arranged periodically at right angles to the longitudinal axis of the myotubes. Round-shaped mitochondria were often arranged in chains connected with slender rods. Long rod-shaped mitochondria exhibited occasional branchings.

Animals↗
PubMed1990

[Effect of rokitamycin on bacterial flora in human feces].

Rokitamycin, a newly developed macrolide antibiotic was orally administered to 7 healthy male volunteers (22-25 years) for 7 consecutive days to study changes in bacterial flora and concentrations of the drug in feces, and to observe adverse reactions and laboratory test parameters. A dose of 200 mg (2 tablets: 100 mg/tablet) was given 3 times daily before meals and the fecal studies were done on the 5 days before administration (adm.) [b.a.], at the time of administration (0), and the 3rd, 5th, 7th (the final day of treatment) days during adm. [u.a.] and the 3rd, 5th, 10th, 20th, 30th days after adm. [a.a.]. The results obtained are summarized as follows. 1. Obvious changes in mean populations of total aerobes and enterobacteriaceae were not found. In changes of each bacteria of enterobacteriaceae, Escherichia coli was not observed in cases from initial day of treatment to the 3rd day a.a. Cases from which Citrobacter sp. was isolated tended to increase after 3 days u.a. and gradually decrease after 3 days a.a. Among Gram-negative bacilli, cases where isolation of Pseudomonas sp. was observed increased temporarily on the 3rd u.a., Gram-positive cocci did not show particular patterns of changes. No changes in mean count of total anaerobes were observed during the course of the experiment. Among individual anaerobes, numbers of Lactobacillus and Peptococcaceae decreased slightly from the 3rd day u.a. and returned on the 5th day a.a. 2. Clostridium difficile D-1 toxin was detected in feces at amounts approximately 500 ng/g in 2 cases each on 20th and 30th day a.a., with 1 incidence occurring in the same person on the 2 separate days. 3. The drug was detected in all 7 cases on the 3rd, 5th and 7th days u.a., and in 1 cases each on the 5th and the 30th day a.a. The mean peak level was 315.5 micrograms/g on the 7th day u.a. The reason for the detection of the drug in feces in 1 case on the 30th day a.a. at a value of 5.90 micrograms/g was not clear. 4. Adverse reactions and abnormal laboratory test results due to this drug were not observed in any cases.

Administration, Oral↗
PubMed1990

[Pharmacokinetic and clinical evaluations of aztreonam monotherapy and aztreonam and ampicillin combination therapy in neonates and premature infants].

One-shot intravenous injection of aztreonam (AZT), a monobactam-class beta-lactam antibiotic, 20 mg/kg was administered to 4 neonates and 2 premature infants, a total of 6 cases, and plasma and urinary concentrations and urinary recovery rates were determined. Also, one-shot intravenous injection averaging 70.9 mg/kg/day of AZT alone was given to 0- to 43-day neonates and premature infants in b.i.d. to q.i.d. for an average of 8 days for the treatment (6 cases) and prophylaxis (11 cases) of infections. Furthermore, a combination therapy of AZT and ampicillin (ABPC) was applied to 0- to 79-day neonates and premature infants for the treatment (28 cases) and prophylaxis (18 cases) of infections. Average daily dosage of AZT 46.6 mg/kg was given by one-shot intravenous injection or by drip infusion in b.i.d. or t.i.d. for an average of 8 days. Average daily dosage of ABPC 78.6 mg/kg was given in the same daily frequency, route and average duration as AZT. Thus, clinical effects, prophylactic effects against infection, bacteriological effects as well as side effects and clinical laboratory test values were studied with the following results. 1. When AZT 20 mg/kg was administered to 1 case each of 6- and 7-day neonates by one-shot intravenous injection, the plasma concentrations were the highest at 5 minutes after the administration in both cases. Specifically, they were 62.9 and 72.7 micrograms/ml with AUCs of 216.6 and 231.6 micrograms.hr/ml and half-lives of 2.80 and 2.97 hours, respectively. When AZT 20 mg/kg was administered to 5- and 6-day premature infants by one-shot intravenous injection, the plasma concentrations were the highest at 15 minutes after administration in the former and 5 minutes in the latter, at values of 59.8 and 67.7 micrograms/ml, respectively. AUCs were 356.6 and 363.2 micrograms.hr/ml, respectively, and larger than AUCs of the above-mentioned neonates. Half-lives were 5.74 and 4.87 hours, respectively and longer than those of the above-mentioned neonates. When AZT 20 mg/kg was administered to 8- and 13-day neonates by one-shot intravenous injection, the plasma concentrations were the highest at 30 minutes after administration in the former and 5 minutes in the latter, at values of 43.4 and 76.9 micrograms/ml, respectively. AUCs were 202.9 and 189.8 micrograms.hr/ml, and 76.9 micrograms/ml, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Ampicillin↗
PubMed1990

[Influence of fetal position on respiratory function and its modification by epidural anesthesia in supine pregnant women].

We investigated the influence of fetal position on respiratory function and its modification by epidural anesthesia in supine pregnant women. We found that supine pregnant women in whom the fetus was in the right occipital anterior position (ROA) had lower inspiratory reserve volume (IRV) and vital capacity (VC) than controls in whom the fetus was in the left occipital anterior position (LOA). When the analgesic level was up to Th7 or lower, epidural anesthesia increased the VC of women with a ROA fetus and also increased IRV. With higher analgesic levels up to Th4-Th6, tidal volume (TV) and VC increased independently of fetal position. We speculate that the pressure caused by the ROA fetus on thorax of the mother is stronger and that after epidural anesthesia this pressure decreases even though the analgesic level is low, and with the analgesic level up to Th4-Th6, the level used for Cesarean section, the displacement of the uterus makes respiration during rest easier regardless of fetal position.

Anesthesia, Epidural↗
PubMed1989

[Definition of the adaptation of endoscopic surgery for early gastric cancer. Special examination on the relationship between the histological differentiation of the intramucosal gastric cancer and the lymph node metastasis].

Out of five hundred and nineteen surgically resected lesions which were histologically shown to be intramucosal gastric cancer, 247 were well differentiated, 98 were moderately differentiated, and 176 were poorly differentiated lesions. The incidence of lymph node metastasis in the 247 well differentiated, 98 moderately differentiated, and 176 poorly differentiated intramucosal adenocarcinomas were 0.8% (= 2/247), 2.1% (= 2/98), and 8% (14/176), respectively. The cumulative survival rate of 5 years after gastrectomy was 94.2% for the 247 well, 93.3% for the 98 moderately, and 93.7% for the 176 poorly differentiated adenocarcinomas. A pathological study on the atypism of the gland of the cancer and the condition of the proprial space under the cancer cells was conducted on 100 lesions of well differentiated adenocarcinomas in order to define the criteria of non-surgical endoscopic removal resection for early gastric cancer. Out of the 100 lesions mentioned above, there were only two well differentiated adenocarcinomas with lymph node metastasis in which the boundary between the epithelium of the cancer and the proprial space under the cancer was very unclear and the interstitial space in the propria under the cancer was very small. On the other hand, we have resected 73 intramucosal gastric cancers using the endoscopic surgical method called strip biopsy since 1984, and have followed up these cases. The cancers resected by strip biopsy, and were histologically intramucosal well differentiated adenocarcinomas shown to have a moderately maintained interstitial space under the cancer cells. And, up to the present, there has been no incidence of recurrence after strip biopsy for the 73 lesions mentioned above. According to these results, we have defined the criterion for early gastric cancer endoscopic surgery, as follows. Intramucosal cancer which is shown to be well differentiated adenocarcinoma with a moderately maintained interstitial space under the cancer cells is considered to be sufficient for non-surgical endoscopic resection.

Aged↗
PubMed1989

Myofibril assembly is linked with vinculin, alpha-actinin, and cell-substrate contacts in embryonic cardiac myocytes in vitro.

The relationship of nascent myofibrils with the accumulation of adhesion plaque proteins and the formation of focal cell contacts was studied in embryonic chick cardiac myocytes in vitro. The cultures were double-stained with various combinations of the specific antiactin drug phalloidin and antibodies against vinculin, alpha-actinin, connectin (titin), myosin heavy chain, fibronectin, and desmin and examined under fluorescence and interference reflection microscopy. In the areas of myofibril assembly, vinculin and alpha-actinin plaques were formed at the ventral sarcolemmae. These areas overlapped with the sites of cell-to-substrate focal contacts and extracellular fibronectin. Because the myofibrils always ran in a straight line between these sites, polarized lines appeared to be generated within the cells in response to their physical (e.g., stress) and/or biochemical environment (e.g., adhesion plaque proteins). The possible presence of other factors cannot be ruled out for the proper alignment of myofibrils. As soon as myofibrils came to span between these adhesion sites, they exhibited typically mature cross-striated characteristics. Thus, the formation of these inferred lines has some relation to, or is in fact necessary for, the maturation of myofibrils, in addition to the directional arrangement of sarcomeric proteins. Additionally, synthesis and distribution of myosin and connectin were tightly linked during early developmental (premyofibril and myofibril) stages. The spatial deployment of desmin was not coupled with vinculin. Thus, connectin and desmin do not appear to form the initial scaffold of sarcomeres.

Actinin↗
PubMed1989

Plasmid multimerization is dependent on RAD52 activity in Saccharomyces cerevisiae.

A mutant plasmid, pX, derived from the 1453 base pair small plasmid, YARp1 (or TRP1 RI circle), consists of 849 base pairs of DNA bearing the TRP1 gene and the ARS1 sequence of Saccharomyces cerevisiae and, unlike YARp1 and other commonly used yeast plasmids, highly multimerizes in a S. cerevisiae host. The multimerization of pX was dependent on RAD52, which is known to be necessary for homologous recombination in S. cerevisiae. Based upon this observation, a regulated system of multimerization of pX with GAL1 promoter-driven RAD52 has been developed. We conclude that the regulated multimerization of pX could provide a useful model system to study genetic recombination in the eukaryotic cell, in particular to investigate recombination intermediates and the effects of various trans-acting mutations on the multimerization and recombination of plasmids.

DNA, Circular↗