Biomedical subjects

Y Sakata

Publications and source records attributed to Y Sakata.

At least 289 records · Page 16Linked to original sources

PubMed1991

The natural history and timing of the radical operation for subpulmonic ventricular septal defects.

In order to further understand the natural history and timing of repair for subpulmonic (type I) ventricular septal defect (VSD), 70 patients who underwent radical surgery were reviewed. The patients with this type of VSD accounted for 30 per cent of a total 236 children with types I, II and III VSD who underwent repair between 1978 and 1989. The frequency of aortic regurgitation was 30 per cent, being higher in the group aged older than 10 years than in the younger group (p less than 0.05). The median ages of patients with normal, prolapsed and regurgitated valves were 5, 6.5, and 10 years, respectively, and each value exhibited significant differences (p less than 0.05). The left to right shunt ratio and systolic pulmonary artery pressure of the patients with normal valves were significantly higher than those of the patients with abnormal valves. The outcome of the patients with regurgitation varied according to Sellers grading with cases of grade two valvular deformities recovering well after the repair, while cases of grade three had deformities of grade one or two severity remaining. These results led us to establish the following strategy for patients with I-VSD: 1) a child should be regularly checked by USG; 2) a child noted as having a prolapsing valve is recommended to undergo repair by the age of 10 to 12 years; and 3) a child found to have regurgitation should undergo repair as soon as possible, unless the valve regurgitation does not become more severe than Sellers grade two.

Adolescent↗

PubMed1991

Fever and acute-phase response induced in rabbits by intravenous and intracerebroventricular injection of interleukin-6.

We investigated the effect of human recombinant interleukin-6 (IL-6) on body temperature and acute-phase response, including changes in plasma levels of iron, zinc, copper, and fibrinogen and in circulating leukocyte count. The intravenous (IV) injection of IL-6 (2 micrograms/kg) produced a monophasic fever. The intracerebroventricular (ICV) injection of IL-6 produced a dose-dependent fever that developed gradually and remained elevated throughout the 5-h recording period. The IV injection of IL-6 decreased the plasma concentration of iron and zinc and increased the circulating leukocyte count. The ICV injection of IL-6 resulted in similar trace metal and leukocyte changes, and increased plasma levels of fibrinogen. These results show that IL-6 can cause fever when injected IV or ICV and induces some acute-phase responses through its action on peripheral target organs and in the central nervous system.

Animals↗

PubMed1991

Prostaglandin E2 is involved in adrenocorticotrophic hormone release during swimming exercise in rats.

1. We found that adrenocorticotrophic hormone (ACTH) release in rats induced by acute swimming exercise or by an intravenous injection of human recombinant interleukin-1 beta (IL-1 beta) was significantly attenuated after chronic exercise. 2. Since involvement of prostaglandins in the ACTH response induced by IL-1 is well known, we investigated the effect of indomethacin, an inhibitor of prostaglandin synthesis, on the ACTH response induced in rats by acute swimming exercise. Pretreatment with an intravenous injection of indomethacin significantly suppressed the ACTH response induced by exercise. The effect of indomethacin (1 and 10 mg/kg) on the ACTH response was dose-dependent. 3. The effect of chronic exercise on the exercise-induced changes in the plasma concentration of prostaglandin E2 was investigated. The plasma concentration of prostaglandin E2 significantly increased after acute exercise in both the control and the chronically exercised rats. However, the increase in the plasma level of prostaglandin E2 was significantly smaller in the chronically exercised group than in the control group. 4. Intravenous injections of prostaglandin E2 produced dose-dependent increases in the plasma concentration of ACTH in rats. 5. The present results suggest that an increase in prostaglandin E2 levels in plasma is involved in the development of the ACTH response induced by exercise.

Adrenocorticotropic Hormone↗

PubMed1991

The effect of chronic exercise on the pituitary-adrenocortical response in conscious rats.

1. This study was designed to investigate the effect of chronic exercise on exercise-induced changes in plasma concentrations of adrenocorticotrophic hormone (ACTH) and corticosterone in rats. Corticotrophin releasing factor (CRF) and ACTH were injected I.V. in order to assess the responsiveness of the pituitary and adrenal glands after chronic exercise. 2. The concentrations of ACTH and corticosterone in the plasma increased significantly after acute exercise in both the control and the exercised groups but both responses were significantly smaller in the exercised group. 3. The ACTH response to I.V. CRF was also significantly smaller in the exercised rats. However, both groups of animals showed similar increases in plasma corticosterone levels after the administration of exogenous ACTH. 4. The ACTH response to CRF attenuated by repeated administration of CRF. 5. These results suggest that attenuated ACTH and corticosterone responses to acute exercise after chronic exercise result from reduced responsiveness of the pituitary gland to CRF.

Adrenal Glands↗

PubMed1991

[Alpha-hemolytic streptococcal septicemia and meningitis in immunocompromised children].

Many kinds of microorganisms can produce toxic septicemia in immunocompromised hosts. We are reporting alpha-hemolytic streptococcal septicemia and meningitis in two children with hematological malignancies. [Case 1] 6 year old girl who had been suffering from acute lymphocytic leukemia. She had sepsis and bacterial meningitis in maintenance-therapy for leukemia. Streptococcus sanguis was isolated from the blood and cerebrospinal fluid (CSF). [Case 2] 11 year old girl who had had malignant lymphoma (non-Hodgkin type). She also had sepsis and bacterial meningitis due to Streptococcus mitis which was isolated from blood and CSF in maintenance-therapy. Both cases had been treated with anti-cancer drugs and had severe granulocytopenia. Positive rate of blood cultures during the recent 6 years (1984.1-1989.12) at our department was 6.0% (total number of cultures were 2,019, positive cultures were 121). Strains of 131 bacteria were determined; Gram-positive cocci were 70 strains (53.4%) and Gram-negative rods were 52 strains (39.7%). Fifteen strains (11.5%) of alpha-hemolytic Streptococci were isolated during 6 years. One hundred thirteen cases of septicemia were analysed in medical charts and 12 cases of alpha-hemolytic streptococcal septicemia were observed (5 cases with infective endocarditis and 7 cases in immunocompromised states).

Child↗

PubMed1991

[Severe infections due to Streptococcus milleri in children].

Streptococcus milleri (S. milleri) is found in healthy individuals in the mouth, nasopharynx, throat, vagina and in feces, and has been reported to be isolated from several infectious diseases in man, particularly from abscess in various parts of the body. We report two cases of severe infections due to S. milleri isolated from subdural abscess and pleural empyema. [Case 1] 13 year old boy who had been healthy until he was noticed to have meningeal signs and was diagnosed as left subdural abscess with siagonantritis by cranial CT scans. S. milleri was isolated from subdural abscess and maxillary sinus. [Case 2] 10 year old boy who had encephalitis and severe mental retardation after measles at 6 months of age. He had a fever, dyspnea and chest X-ray abnormalities and was diagnosed as right pleural empyema. Three strains of organism, S milleri, Bacteroides spp. and Fusobacterium nucleatum were isolated from the pleural effusion.

Adolescent↗

PubMed1991

Phospholipid metabolism in cardiomyopathic hamster heart cells.

We demonstrated that the activities of phosphatidylinositide-specific phospholipase C, inositol 1,4,5-trisphosphate (IP3) kinase, and IP3 phosphatase were enhanced in cardiomyopathic hamster hearts (BIO 14.6 and BIO 53.58) in comparison to control hamsters (F1b). Release of both arachidonic acid and prostacyclin was markedly enhanced by norepinephrine in the cardiomyopathic hamsters. Phospholipase C in heart has high substrate specificity to phosphatidylinositol. IP3 production was markedly enhanced in the cardiomyopathic hamsters. We also determined the intracellular calcium concentration, which was higher in BIO 53.58 hamsters than in BIO 14.6 hamsters at 5-20 weeks of age. There was no significant difference in the intracellular calcium level between F1b and BIO 14.6 hamsters at 5 weeks of age. These results suggest that phosphatidylinositol turnover stimulated by norepinephrine may produce high intracellular calcium levels in both BIO 14.6 and BIO 53.58 myocytes. In addition, in BIO 53.58 hamsters, some mechanism such as the sarcoplasmic reticulum, which controls the intracellular calcium level, may deteriorate in function. We concluded from these results that a prolonged high intracellular calcium level may lead to the death of BIO 53.58 myocytes.

6-Ketoprostaglandin F1 alpha↗

PubMed1991

Analysis of saccadic eye movements using an infrared video system in human subjects.

Horizontal and vertical saccades were recorded and quantitatively analyzed with an infrared video recording system in 6 normal human subjects. Peak and mean saccade velocities increased exponentially as the amplitude increased. Peak velocity of horizontal saccade was significantly larger than that of vertical saccade (p less than 0.05, ANOVA test). On the other hand, duration and latency showed a linear relationship with saccade amplitude. Latency was constant (i.e. 0.21 s) irrespective of saccade amplitude in the regular eye tracking mode; however, latency slightly increased as the amplitude became larger in the randomized eye tracking mode. As a result, a slight positive correlation could be found between saccade amplitude and latency: r = 0.50 and 0.35 in horizontal and vertical saccades, respectively.

Adult↗

PubMed1991

[A phase II study of SM-5887 for advanced gastric cancer].

A phase II clinical trial of SM-5887, a new totally synthesized anthracycline derivative, was carried out in 13 patients with inoperable or recurrent gastric cancer. No patient had been given anthracycline previously. SM-5887 was administered by I.V. bolus with a dose of 100 mg/m2 every three weeks. Twelve of 13 cases were eligible and evaluable for the response. Of the 12 evaluated cases, 6 showed no change (NC), including one minor response (MR). The remaining 6 cases showed progressive disease (PD). Adverse effects were relatively mild in most cases and included anemia, leukocytopenia, thrombocytopenia, nausea/vomiting, phlebitis, hair loss and fever. Among them, leukocytopenia was observed most frequently.

Adenocarcinoma↗

PubMed1991

[Cases of advanced cholangiocarcinoma showing partial response by the combination chemotherapy including protracted continuous infusion of 5-FU combined with intravenous administration of low-dose leucovorin and intra-arterial administration of MMC and CQ].

We treated a patient with advanced cholangiocarcinoma with a new combination chemotherapy (modified MQF). The regimen consisted of intra-arterial administration of MMC (20 mg/body) and CQ (4 mg/body), protracted continuous infusion of 5-FU (500 mg/body) and intravenous administration of low-dose leucovorin (30 mg/body). More than 50% reduction in the liver tumor for over 4 weeks was obtained by the therapy. As for toxicity, diarrhea and stomatitis were observed.

Adenoma, Bile Duct↗

PubMed1991

[Methicillin-cephem-resistant Staphylococcus aureus (MRSA) mediastinitis following open heart surgery].

Mediastinitis following cardiac surgery occurs frequently in association with high mortality and morbidity. Patient was a 6-year-old boy suffering from Sotos syndrome with secundum type of ASD. He was operated upon to repair ASD. Following the surgery, he suffered from MRSA mediastinitis and osteomyelitis of the sternum. Routine method of closed irrigation after reopening of the sternal wound was ineffective. Patient recovered following aggressive debridement repeatedly, open drainage and topical irrigation with vancomycin. This appears to be a useful method to treat MRSA mediastinitis of the sternum.

Cephalosporins↗

PubMed1991

[An early phase II study of CPT-11 in primary lung cancer].

An early phase II study of CPT-11 was carried out in patients with primary lung cancer in 15 institutions throughout Japan. The efficacy and safety of CPT-11 were studied at 200 mg/m2 based on the results of the previous phase I study. Thirty-eight of 52 enrolled patients were eligible. CPT-11 proved to be effective for primary lung cancer. The response rates were 20.0% (7/35) for non-small cell lung carcinoma and 33.3% (1/3 for small cell lung carcinoma. Hematological toxicities included leukopenia (less than or equal to 3,000) in 44.7% of the patients. Other major toxicities were nausea/vomiting (greater than or equal to grade 2) in 50.0% and diarrhea (greater than or equal to grade 2) in 47.4%.

Adenocarcinoma↗

PubMed1991

[Seven cases of eye involvement in adult with acute leukemia].

Seven acute leukemia cases with oculomotor paralysis and/or optic nerve paralysis were reported. Five cases were lymphoblastic and two were myelogenous leukemia. The average age was 30.7 years old and male to female ratio was 5:2. The eye involvement developed during hematological complete remission stage in 4 cases, and during relapsing stage in 2 cases. For the remaining case, eye symptom was an initial symptom of the disease. The computed tomography of ocular region showed tumorous involvement in 3 cases and no abnormality in other 4 cases. The white blood cell count on admission was over 30,000/microliters and leukemic cells occupied over 59% of bone marrow nucleated cells in 5 cases. Intrathecal administration, a whole brain irradiation and intra-arterial injection of Nimustin as well as standard systemic chemotherapy were performed against oculomotor and optic nerve involvement. Leucoencephalopathy occurred in 2 of 7 cases after intrathecal administration and irradiation. Since 1980, continuous treatment for prophylaxis of central nervous system leukemia have been done and this protocol was effective for meningeal involvement but not for ocular involvement.

Acute Disease↗

PubMed1991

[Factors relating to postoperative infections in cancer patients].

Some factors relating to the increasing prevalence of postoperative infections after gastroenterological surgery were investigated from the standpoint of both patients profile and isolated bacteria. Data were collected from 542 cancer patients comprising 39 with esophagus cancer, 229 with gastric cancer, 149 with hepato-biliary tract and pancreatic cancer and 125 with colon cancer. Respiratory infections after operations were most frequently caused by aging, disturbance of glucose tolerance and respiratory dysfunction, whereas with intraabdominal abscess the major factors were disturbance of glucose tolerance, hepatic dysfunction and respiratory dysfunction in this order. Two factors in the management of patients during operation were singled out as mainly contributing to infection: these were prolonged operative time as in the case of esophagus cancer or hepato-biliary tract and pancreatic cancer, and massive intraoperative bleeding as in hepato-biliary tract, pancreatic and gastric cancer. As isolated bacteria, the most frequent clinical isolates were MRSA, Enterococcus, P. aeruginosa and Enterobacter, and it is noteworthy that all of these were strongly resistant to all antimicrobial agents. The greater emphasis on prevention control of postoperative infections, therefore, should be focussed on aging, preoperative risk factors, surgical stress and the kinds of antimicrobial agents administered.

Bacterial Infections↗

PubMed1991

[Effects of dopamine and dobutamine on systemic hemodynamics and myocardial metabolism in children after open heart surgery].

The purpose of this study is to know the effects of Dopamine (DOA) and Dobutamine (DOB) on the systemic hemodynamics and myocardial metabolism in the acute phase after open heart surgery in children. Thirty patients with congenital heart disease were divided into following two groups. The first 14 cases were administered 5 and 10 micrograms/kg/min (gamma) of DOA, and the systemic hemodynamic and metabolic data were taken before and after the administration of the drug. The second 12 cases were given the same doses of DOB instead of DOA. DOA: The blood pressure was elevated by 10 gamma of DOA, and cardiac index (CI) and stroke volume index (SVI) rose up at both doses of DOA. On the other hand, systemic vascular resistance (SVR) and left atrial pressure (LAP) were decreased at both dosage levels. DOB: At the same dose of DOA, DOB increased HR and SVI, so CI rose up markedly. The systolic and mean blood pressure also rose up at both doses. CVP and LAP were depressed at either dosage level. SVR did not show an appreciable change. Myocardial metabolism: The two drugs tested did not exhibit the progress of anaerobic myocardial metabolism. The myocardial oxygen uptake rate increased with DOA, but decreased with DOB. This phenomena probably suggests that DOB dilates coronary vascular bed. From the above data, the following effects are expected by the use of each drug after open heart surgery in children: 1) an increase of cardiac output due to inotropic action by DOA, 2) powerful inotropic and chronotropic action by DOB.

Child↗

PubMed1990

ACTH response induced by interleukin-1 is mediated by CRF secretion stimulated by hypothalamic PGE.

We investigated whether hypothalamic prostaglandin E2 (PGE2) and corticotropin releasing factor (CRF) are responsible for the development of the adrenocorticotropic hormone (ACTH) response induced by interleukin-1 alpha (IL-1 alpha). The present results show that ACTH responses induced by intravenous injection of IL-1 alpha were suppressed by systemic pretreatment with indomethacin and that intrahypothalamic injection of PGE2 stimulates the secretion of ACTH. Furthermore, systemic pretreatment with anti-CRF antibody significantly suppressed the ACTH response induced by intrahypothalamic injection of PGE2. These data suggest that the ACTH response induced by IL-1 is mediated by CRF secretion stimulated by hypothalamic PGE2.

Adrenocorticotropic Hormone↗

PubMed1990

Initiation of meiosis and sporulation in Saccharomyces cerevisiae requires a novel protein kinase homologue.

SME1 was cloned due to its high copy number effect: it enabled MATa/MAT alpha diploid cells to undergo meiosis and sporulation in a vegetative medium. Disruption of SME1 resulted in a recessive Spo- phenotype. These results suggest that SME1 is a positive regulator for meiosis. DNA sequencing analysis revealed an open reading frame of 645 amino acids. An amino terminal peptide of ca 400 amino acids in the deduced protein was similar to known protein kinases. Transcription of SME1 was regulated negatively by nitrogen and glucose and positively by MATa/MAT alpha and IME1, another positive regulator gene of meiosis. By complementation analysis, SME1 was found to be identical to IME2, which had been shown to be important in meiosis. These results suggest that IME1 product stimulates meiosis by activating transcription of SME1 (IME2) and that protein phosphorylation is required for initiation of meiosis.

Amino Acid Sequence↗

PubMed1990

Antitumor effect of combination of murine recombinant interferon beta, murine recombinant interferon gamma and human recombinant interleukin-2 in MethA-bearing mice.

We have previously reported that the combination of murine recombinant interferon beta (Mu-rIFN beta) with murine recombinant interferon gamma (Mu-rIFN gamma) provided greater inhibition of tumor growth than did each one alone in MethA-bearing mice. In the present study the effect of addition of human recombinant interleukin-2 (Hu-rIL-2) to the combination of Mu-rIFN beta with Mu-rIFN gamma on tumor growth in BALB/c mice bearing syngeneic MethA fibrosarcoma was examined. Low doses of Hu-rIL-2 (5 x 10(3) U or 5 x 10(4) U at 3-day intervals) showed no antitumor activity, while a high dose of Hu-rIL-2 (5 x 10(5) U) showed profound growth inhibition. The administration of IL-2 (ranging between 5 x 10(3) U and 5 x 10(5) U) in addition to the combination of IFN beta and IFN gamma showed more augmented antitumor effects in a dose-dependent manner. Furthermore, the simultaneous administration of IL-2, IFN beta and IFN gamma had more effective therapeutic activity, compared with the sequential administration of interferons and IL-2. These findings indicated that IL-2 in combination with IFN beta and gamma was effective for cancer treatment.

Animals↗