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Biomedical subjects

Y Shimada

Publications and source records attributed to Y Shimada.

At least 721 records · Page 40Linked to original sources
PubMed1984

The unique responses of the primordial germ cells in the fish Oryzias latipes to gamma-rays.

The effects of gamma-radiation on the development of the primordial germ cells (PGCs) of medaka embryos (Oryzias latipes) during the early stages of development were quantitatively examined and compared to the effects on the intestinal cells. The PGCs develop in three stages: an extra-gonadal proliferative stage (1-2.5 days after fertilization), a mitotically inactive stage after the termination of the migration into the gonad (2.5-4.5 days), and an extensive proliferative stage (between 4.5 days and hatching). A dose-rate effect was absent in the PGCs, regardless of their mitotic activity, when dose rates were 2.5 and 0.14 Gy/min. The radiation effect on the PGCs was not reduced by hypoxia and was not enhanced by heat treatment during the proliferating stages. Conversely, radiation resistance was induced in the PCGs during the mitotocally inactive stage by hypoxia and, unexpectedly, by heat treatment. From the present data, we conclude that the PGCs have a small repair ability, and we discuss the radiation resistance induced in the PGCs by hypoxia and heat treatment.

Animals↗
PubMed1984

Evaluation of a system for on-line analysis of VO2 and VCO2 for clinical applicability.

The authors evaluated the accuracy of a system to measure respiratory gas exchange on an on-line basis by comparing it with a gas collection method. The system incorporates a hot-wire flowmeter, a mass spectrometer, and a microcomputer. It performs on-line compensation for both transport delay and dynamic response of the mass spectrometer. Compensation of flow measurement for changing gas fractions also is performed. Excellent linear correlations were obtained between the two methods: 1) in animals during mechanical ventilation with room air (VO2:r = 0.995; VCO2:r = 0.993), and nitrous oxide in oxygen (VO2:r = 0.975; VCO2:r = 0.976); and 2) in men spontaneously breathing room air at different workloads (VO2:r = 0.999; VCO2:r = 0.998), and higher inspired oxygen fractions (FIO2 0.38 to 0.75) (VO2:r = 0.910; VCO2:r = 0.988). The authors consider that the system is suited for accurate and continuous measurement of respiratory gas exchange during mechanical ventilation, anesthesia, and exercise testing.

Adult↗
PubMed1984

High-frequency jet ventilation for differential lung ventilation.

High-frequency jet ventilation using a jet injector located at the right mainstem bronchus was superimposed on standard mechanical ventilation to ventilate the injured lung of a patient with unilateral massive atelectasis secondary to pulmonary hemorrhage. This technique of differential ventilation markedly improved arterial oxygenation in this patient and may prove to be a simpler modality of respiratory support in patients who have respiratory failure from unilateral lung disease.

Hemorrhage↗
PubMed1984

Plasma lipid peroxides and alpha-tocopherol in critically ill patients.

Plasma lipid peroxide measured as thiobarbituric acid reactive substances (TBARS) and alpha-tocopherol levels in 24 critically ill patients were compared with those of control subjects. The mean plasma alpha-tocopherol level was significantly lower and the mean TBARS level was significantly higher in critically ill patients. Eight ICU patients developed disseminated intravascular coagulation (DIC); the mean TBARS level during DIC was significantly above the mean pre-DIC level. These results indicate that lipid peroxidation may contribute to the development of DIC in critically ill patients.

Adolescent↗
PubMed1984

Changes in subcortical visual and auditory evoked potentials following amygdaloid kindling in cats.

In this study we dealt with the changes in visual and auditory evoked potentials following kindling, to reveal the distant effects of epileptic activity. The experiments were performed using cats. Visual and auditory evoked potentials were obtained initially. Daily stimulation of 60 Hz (rectangular wave, 1 ms in duration, 500 microA in peak current, 2-s train) was given to the right amygdala, for kindling. After the completion of kindling, evoked responses were recorded again. In the auditory system the changes of responses in the cortex, medial geniculate nucleus, and cochlear nucleus were distinguished. The changes of potentials in the subcortex were larger than those at the cortical level. For visual evoked potentials there was a discrepancy between stimulation with light and electrical stimulation of the optic chiasm. There was no significant change in amplitude of visual evoked potentials by flash. In the case of optic chiasm stimulation, an enlargement of evoked responses was obtained. These results indicate modality-specific change of the auditory system and widespread subcortical change. These results might be caused by some vulnerability of the auditory system in the case of amygdaloid kindling, as a result of the epileptogenic process.

Amygdala↗
PubMed1984

Use of sulfur hexafluoride, SF6, in the management of the postpneumonectomy pleural space.

After a pneumonectomy in patients of advanced age with lung cancer, overinflation of the contralateral lung causes a further emphysematous change. This aggravation of emphysematous disturbances occasionally leads to serious cardiopulmonary dysfunctions. Therefore, we have devised a new therapeutic method which consists in injecting sulfur hexafluoride, SF6, an inert gas, into the postpneumonectomy pleural space so as to maintain the chest cavity. As SF6 gas is slowly absorbed through the pleura, gas injection at intervals of 6 months can maintain a clear pleural space with neither retention of pleural effusion nor deformity of the thorax. As a result, in 23 patients who were treated by this method, overinflation of the contralateral lung after unilateral pneumonectomy could be prevented, and respiratory functions could be improved, i.e., the vital capacity increased about 20% and the residual volume decreased over 20% after SF6 gas injection. All patients have been in good condition of their performance status, and it was not disadvantageous to continue the SF6 gas injection for a long term such as several years.

Empyema, Tuberculous↗
PubMed1984

[Fundamental and clinical studies of sulbactam/cefoperazone in the pediatric field].

To 6 cases of children in 2 groups of 3 each, newly developed sulbactam/cefoperazone (SBT/CPZ) was given at 20 and 40 mg/kg by intravenous bolus injection, respectively, and the serum and urinary concentrations and recoveries of SBT and CPZ were determined. To 1 case of purulent meningitis, this drug was given at 40 mg/kg by intravenous bolus injection, and the cerebrospinal fluid and serum concentrations of SBT and CPZ were determined. Susceptibility tests to SBT/CPZ and CPZ of total 289 strains were conducted; Gram-positive cocci tested consisted of 26 S. aureus strains, 20 S. pyogenes strains and 21 S. pneumoniae strains, and Gram-negative bacilli consisted of 24 H. influenzae strains, 22 E. coli strains, 26 K. pneumoniae strains, 24 E. cloacae strains, 21 E. aerogenes strains, 19 Citrobacter sp. strains, 20 S. marcescens strains, 23 P. mirabilis strains, 23 indole-positive Proteus sp. strains and 20 P. aeruginosa strains. SBT/CPZ was given to total 43 cases at a mean daily dosage of 80.4 mg/kg, in 3 or 4 divided doses (6 cases in 3 and 37 cases in 4), 1 case receiving the drug by drip infusion over 30 minutes (in 3 divided doses) and all the other 42 cases by intravenous bolus injection, for 7 days on an average. They consisted of 2 cases of tonsillitis, 1 case of otitis media, 1 case of otitis media associated with mastoiditis, 30 cases of pneumonia, 1 case of suspected septicemia, 1 case of purulent meningitis, 5 cases of urinary tract infection, 1 case of purulent lymphadenitis and 1 case of submaxillaritis. And the clinical and bacteriological effects were evaluated. Also, side reactions and laboratory examinations for abnormal values due to administration of this drug were made on 47 cases including 4 drop-outs. The following results were obtained: After administration of this drug to 2 groups of 3 children each at 20 and 40 mg/kg by intravenous bolus injection, mean serum concentrations of both SBT and CPZ reached the peaks in 5 minutes; SBT levels were 60.9 and 124.7 micrograms/ml for the 2 groups and CPZ levels were 105.0 and 214.1 micrograms/ml, respectively. In either group, CPZ levels were 1.7 times as high as SBT levels, and there was observed a dose-response in both. In the 20 mg/kg group, mean half-lives of SBT and CPZ were 0.96 and 1.24 hours, respectively, and in the 40 mg/kg group, they were 1.01 and 1.32 hours, CPZ values tending to be longer.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1984

[Fundamental and clinical evaluation of ceftriaxone in the pediatric field].

Fundamental and clinical evaluation on ceftriaxone (Ro 13-9904, CTRX), a newly-developed injectable cephem antibiotic was performed as follows. The serum and urine concentrations of CTRX as well as the urinary recovery rate were determined in 7 children at 3 different dose levels; 3 cases administered with 10 mg/kg, 3 with 20 mg/kg and 1 with 48 mg/kg by one shot intravenous injection. The concentration in the cerebrospinal fluid was determined in 1 case of purulent meningitis associated with bacteremia, administered by one shot intravenous injection with 47.6 mg/kg. CTRX was also examined in its clinical and bacteriological efficacies by one shot intravenous injection for 8 days on average in a mean daily dose of 46.5 mg/kg, divided into twice a day in 31 cases, 3 times in 1 case, and 4 times changed from twice in 1 case; in a total of 33 children consisting of 3 with tonsillitis, 1 with chronic bronchitis, 20 with pneumonia, 2 with purulent meningitis associated with bacteremia, 3 with urinary tract infections, 1 with osteomyelitis associated with phlegmon, 3 with purulent lymphadenitis. The adverse reactions and laboratory test values were examined in a total of 40 cases, i.e., the above-mentioned 33 cases plus the 7 drop-out cases in which the clinical efficacy could not be evaluated. The results were as follows. The serum levels of CTRX in 7 cases consisting of 3 administered with 10 mg/kg, 3 with 20 mg/kg and 1 with 48 mg/kg reached their peaks 5 minutes after one shot intravenous injection and the mean values of them were 93.6 mcg/ml, 143.0 mcg/ml and 558.0 mcg/ml, respectively, indicating the existence of a dose-response among these groups, while the half-life times were 4.41, 5.86 and 4.09 hours. Among the 7 cases examined in the urinary levels as well as the serum levels, the 3 cases administered with 10 mg/kg reached the mean peak of 334.0 mcg/ml 2 to 4 hours after administration, while another 3 cases administered with 20 mg/kg showed peaks of 793.0, 522.0 and 536.0 mcg/ml, respectively, 2 to 4 hours, 4 to 6 hours and 6 to 12 hours after injection; this dispersion being partly because of that the urine specimen was unable to be collected regularly every hour in this dose group. In the case administered with 48 mg/kg, urinary level reached the highest value of 6,100.0 mcg/ml from 0 to 2 hours.(ABSTRACT TRUNCATED AT 400 WORDS)

Age Factors↗
PubMed1984

[A case of portal hypertension with massive gastrointestinal bleeding from ileal varices].

A rare case of massive gastrointestinal bleeding from ileal varices was reported. On December 28, 1982, a 49-year-old male was admitted to Kurashiki Central Hospital because of massive gastrointestinal bleeding. Eleven years ago, the patient underwent an emergency operation for rupture of esophageal varices. The venous phase of selective superior mesenteric and celiac angiography showed mesenteric varices, but no definite bleeding point was noted. Endoscopy revealed esophageal varices, but no area of bleeding was encountered. Because of frequently repeated hemorrhages, laparotomy was performed. A large vein was found on the surface of the ileal wall, through an adhesion to the lateral pelvic wall. Partial resection of ileum was performed. Histological examination of the resected small bowel demonstrated ruptured submucosal varices. The postoperative course was uneventful and he was discharged on the 40th postoperative day. It is stressed that this disease should be considered as a differential diagnosis for a patient with lower gastrointestinal bleeding and portal hypertension.

Gastrointestinal Hemorrhage↗
PubMed1984

[Fundamental and clinical studies of ceftazidime in the pediatric field].

Ceftazidime ( CAZ ), a newly-developed parenteral cephem antibiotic, was administered to 8 children; by one shot intravenous (i.v.) injection in the doses of 20 and 40 mg/kg each to 2 children, and by 30 minutes' i.v. drip infusion in the doses of 10 and 20 mg/kg each to 2 children, and the serum levels, urinary levels and recovery rates were determined. CAZ was also administered to 2 patients with purulent meningitis, one complicated with subdural abscess and the other with bacteremia, in the doses of 19.2 and 50.7 mg/kg, respectively, by one shot i.v. injection, and the CSF level of CAZ was determined. In addition, CAZ was administered to 2 children with acute bronchitis, 1 with chronic bronchitis, 37 with pneumonia, 3 with pleuropneumonia, 1 each for purulent meningitis, purulent meningitis accompanied with subdural abscess and purulent meningitis with bacteremia, 5 with urinary tract infections and 3 with purulent lymphadenitis (total 54 children), in the mean dose of 85.8 mg/kg/day mostly in 4 divided doses by one shot i.v. injection for 9 days on the average, and clinical effectiveness and bacteriological response were evaluated in these cases, and adverse events and abnormal laboratory findings were examined in the 66 cases which included 12 drop-out cases. 1. After the administration of CAZ to 4 children; 20 and 40 mg/kg each to 2 children, by one shot i.v. injection, the mean serum levels got to the peak of 115.8 and 199.5 mcg/ml, respectively, at 5 minutes. The results were good, showing dose response. The mean half-lives were 1.48 and 1.37 hours, respectively. After the administration of 10 and 20 mg/kg of CAZ each to 2 children by 30 minutes' i.v. drip infusion, the mean serum levels got to the peak of 58.5 and 80.0 mcg/ml, respectively, on completion of the administration, showing dose response. The mean half-lives were 1.06 hours in the former 2 cases, and 1.38 and 3.26 hours, respectively, in the latter 2 cases. The reason for the prolongation observed in 1 case was not clear. 2. In the above mentioned each 2 cases receiving one i.v. injection, the mean urinary levels got to the peak of 4,240 and 4,445 mcg/ml, respectively, at 0-2 hours after the administration , and the urinary recovery rates during the first 6 hours were high, 95.7% and 99.5%, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1984

Myogenesis.

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Actins↗
PubMed1984

Growth-inhibitory activity of human recombinant beta-interferon (GKT-beta) in vitro.

Growth-inhibitory activity of human recombinant beta-interferon (GKT-beta) against 20 human cultured cell lines derived from leukemias and lymphomas was measured quantitatively by regrowth assay. Daudi cells were the most sensitive to GKT-beta. Two T-cell lines (RPMI-8402, HUT78), three B-cell lines (Raji, P3HR-1, A3/Kawakami), one non-T, non-B acute lymphoblastic leukemia (ALL) cell line (KOPN-1) and one monocytoid cell line (U937) were moderately sensitive to GKT-beta. Although the levels of sensitivity of these cell lines to GKT-beta were different, the cells could be killed by GKT-beta. Morphological changes of the sensitive cells treated with GKT-beta were decrease in mitosis, pyknosis and segmentation of cells. Twelve other cultured cell lines, comprising four T-cell lines, four B-cell lines, one non-T, non-B ALL cell line and three myelomonocytoid cell lines, were not sensitive to GKT-beta. The results indicated that the growth-inhibitory activity of GKT-beta was not always cell lineage-specific or differentiative stage-specific. GKT-beta was instable in vitro and its antiviral activity was reduced to about 10% during the first 24 hr of incubation in culture medium with or without cells. This instability was reflected in a similar reduction of its growth-inhibitory activity. It was demonstrated that GKT-beta had a time-dependent, but not a concentration-denpendent antiproliferative action. This suggests that, in the clinical use of the interferon, direct antiproliferative activity of GKT-beta may be expected only through the use of therapeutic schedules which are suitable for its time-dependent action, such as through daily long-term treatment, but not through a single large-dose therapy.

Cell Division↗
PubMed1984

[Clinical trials of cefmetazole for pneumonia and pyothorax caused by Staphylococcus aureus resistant to cefazolin].

Cefmetazole (CMZ), an antibiotic agent of the cephamycin group, is resistant to beta-lactamase and has a broad antibacterial spectrum covering Gram-positive cocci and Gram-negative bacilli. However, it has not been indicated for Gram-positive cocci. We examined its clinical, bacteriological and side effects in 2 infants with pneumonia and 2 with pyothorax, which had been suggested to be caused by CEZ-resistant and CMZ-sensitive Staphylococcus aureus or other inflammatory organisms by a disc sensitivity test, for 2 years and 3 months from January, 1981 to March, 1983. The patients aged 1 to 22 months, and a mean daily dose of 108 to 115 mg/kg was divided into 2 to 4 equal doses and injected into the vein at one shot for a mean fo 19 days. The following results were obtained: The clinical effect of CMZ was evaluated to be good in 1 and fair in 1 of 2 infants with pneumonia, and excellent in 1 and good in 1 of 2 with pyothorax. Bacteriologically, S. aureus was removed in an infant with pneumonia and in 2 with pyothorax. Bacteriological test was not conducted in the remaining 1 with pneumonia. No side effects were found in any cases. Eosinophilia appeared as an abnormal clinical test value in a case, but the number of eosinophils became normal after termination of the medication. As mentioned above, CMZ manifested an excellent clinical effect in infants with pneumonia or pyothorax caused by S. aureus although the number of the patients was small. From the results the antibiotic agent can be expected to be effective in these disease.

Age Factors↗