Biomedical subjects

Y Ishida

Publications and source records attributed to Y Ishida.

At least 487 records · Page 27Linked to original sources

PubMed1990

Effects of hypoxia on high-energy phosphagen content, energy metabolism and isometric force in guinea-pig taenia caeci.

1. Previously, Ishida, Takagi & Urakawa (1984) reported that, in the presence of high K+ (45.4 mM) under hypoxia (95% N2-5% CO2 bubbling), tension and ATP content of the smooth muscle of the guinea-pig taenia caeci increased concomitantly when the glucose concentration was raised. Tension and energy metabolism of the taenia seemed to be closely correlated. In the present experiments, we investigated the metabolic changes during the relaxation phase after the taenia was exposed to hypoxia in the presence of high K+ by measuring the content of phosphagen, inorganic phosphate (Pi) and lactate in the tissue. Oxygen consumption and lactate release from the tissue were also determined to estimate the rate of ATP synthesis. 2. Under hypoxic conditions, high-K(+)-induced tension decreased to one-tenth of maximum in aerobic conditions (95% O2-5% CO2 bubbling); increasing the calcium concentration from 2.5 to 10 mM had no effect. To test receptor-associated stimuli, carbachol or histamine (both 5 microM) had little effect on tension in hypoxia. The calcium ionophore A23187 (10 microM) also did not produce any significant contraction in the presence of high K+ under hypoxia. 3. Hypoxia in the presence of high K+ elicited a rapid decrease in phosphocreatine, approximately in parallel with the decrease in tension. The ATP content decreased gradually while Pi content increased. Lactate content increased rapidly and then partially decreased. 4. The rate of ATP synthesis estimated from the oxygen consumption and lactate release of the taenia was linearly correlated with tension development under aerobic and hypoxic conditions. 5. These results suggest that the decrease in tension of the taenia observed under hypoxic conditions is due to an inhibition of energy metabolism, and not due to an oxygen-sensing step in excitation-contraction coupling.

Adenine Nucleotides↗

PubMed1990

Protective role of complement in the development of experimental pneumococcal pneumonia in mice.

To evaluate the role of complement in the lung defense against Streptococcus pneumoniae, mice decomplemented with multiple injections of cobra venom factor were challenged with type 3 pneumococci by inhalation. Without injection of cobra venom factor, the organisms were eliminated rapidly from the lungs in the majority of mice, accompanied by a significant but transient decrease in the serum C3 level. Focal pneumonia developed occasionally in some mice retaining the organisms in the lungs. By decomplementation with cobra venom factor, on the other hand, pneumococci were not eliminated completely from the lungs during the early stage of infection and afterward proliferated extensively. Consequently, the mice developed typical pneumococcal pneumonia with attendant bacteremia, while the serum C3 level has recovered compensatory during the course of infection. Thus, the complement was indicated to play an important role in the lung defense against pneumococci in mice, especially during the early stage of infection.

Animals↗

PubMed1990

Anticholinergic action of disopyramide in intestinal smooth muscle of the guinea pig: inhibition of muscarinic receptors (M1 and M2).

Antimuscarinic actions of disopyramide were investigated by measuring the contractile responses of intestinal smooth muscles and ligand binding in cardiac and intestinal membrane preparations. Disopyramide caused a parallel shift of the dose-response curves for acetylcholine, McN-A-343, and carbachol to the right in the guinea pig taenia caeci; pA2 values were 5.4 for acetylcholine, 5.5 for McN-A-343 and 5.9 for carbachol. In the guinea pig ileum, disopyramide competitively antagonized acetylcholine in the contractile responses, having the pA2 value of 6.1. In microsomal fractions of the guinea pig taenia caecum and heart, disopyramide was capable of replacing 3H-QNB; K1 values were 7 x 10(-6) M for the taenia and 2 x 10(-6) M for the heart. These results suggest that disopyramide exerts antimuscarinic action through M1 and M2 receptors with a potency approximately 3 times greater for M2 than M1.

(4-(m-Chlorophenylcarbamoyloxy)-2-butynyl)trimethy↗

PubMed1990

Effects of a crude extract of a marine dinoflagellate, containing dimethyl-beta-propiothetin, on HCl.ethanol-induced gastric lesions and gastric secretion in rats.

A crude extract of Crypthecodinium cohnii and its main component, dimethyl-beta-propiothetin, significantly and dose-dependently protected the gastric mucosa against HCl.ethanol-induced lesions in rats. Since indomethacin pretreatment reduced the protective effect to some extent, endogenous prostaglandins might be partly involved in the mechanism of action. Both the crude extract and dimethyl-beta-propiothetin significantly increased gastric secretion.

Animals↗

PubMed1990

Secretion of Aspergillus oryzae alkaline protease in an osmophilic yeast, Zygosaccharomyces rouxii.

To produce Aspergillus oryzae alkaline protease (Alp) in an osmophilic yeast Zygosaccharomyces rouxii, we constructed an expression plasmid consisting of the Z. rouxii glyceraldehyde-3-phosphate dehydrogenase (GAPDH) promoter, the prepro-Alp cDNA of A. oryzae, the whole sequence of Z. rouxii plasmid pSR1, and the G418 resistant gene. The resulting plasmid, when introduced into Z. rouxii cells, directed the secretion of a large amount (about 300 mg/l) of Alp into the culture medium. The N-terminus and specific activity of the enzyme were identical to those of A. oryzae Alp.

Amino Acid Sequence↗

PubMed1990

[Clinical evaluation of aztreonam for infections accompanying febrile neutropenic children with hematologic disorders and solid tumors. A cooperative study].

One hundred four children with infection accompanying hematologic disorders and solid tumors were treated with aztreonam (AZT) (120-150 mg/kg), either alone or in combination with one of the following drugs; cefmetazole (CMZ) (120-150 mg/kg), piperacillin (PIPC) (120-150 mg/kg), or amikacin (AMK) (5-10 mg/kg). The overall efficacy rate was 69.2%. Efficacy rates by regimen were as follows: AZT alone was 63.2%, AZT plus CMZ was 73.6%, AZT plus PIPC was 74.1% and AZT plus AMK was 20.0%. Efficacy rates in different types of infections were 53.2% for sepsis and suspected sepsis, 78.9% for pneumonia and respiratory tract infection, 93.1% for fever of undetermined origin and 55.6% for other infections. The efficacy rate was 71.3% in 94 patients in whom causative organisms were not identified and 50.0% in 10 patients in whom causative organisms were identified. Most of infections in which causative organisms were identified were caused by Gram-negative pathogens. The response rate among infections caused by Gram-negative bacilli was 50.0%. A combination of AZT and CMZ or PIPC was effective in 3 (100.0%) out of 3 patients in whom Escherichia coli was the causative organism. Efficacies classified according to different neutrophil counts were 59.3% for less than or equal to 100/microliters, 78.6% for 101-500/microliters and 82.4% for greater than or equal to 501/microliters. No significant adverse reactions were observed. These results indicated that combination of AZT and 2nd generation cephalosporins or penicillins were well tolerated and effective for infections complicated with accompanying hematologic disorders and solid tumors.

Adolescent↗

PubMed1990

[A case of ossifying fibroma].

A case of ossifying fibroma of the maxillary left suspected as fibrous dysplasia was reported. The patient was a 21 year-old man complaining of a swelling of the gingiva at the left upper molar region. X-ray examination showed a border distinct imradiolucent, a ground glass appearance in partially at the left maxillary region. In the histological findings, the specimen showed a large number of comparatively ripe bone that suspected as Osteoma. At about 3 years postoperatively, no evidence of recurrent has appeared.

Adult↗

PubMed1990

Leprosy and malignancy: autopsy findings of 252 leprosy patients.

The occurrence of malignant tumors in leprosy patients was studied in 252 autopsied cases. Malignant tumors were found in 33 out of 110 autopsy cases from 1962 to 1971, and in 51 out of 141 autopsy cases from 1977 to 1989 (until July). In 1974, a lepromatous case with Kaposi's sarcoma was autopsied. The incidence of malignant tumors in our 252 cases were 33.7% (85 out of 252). Carcinoma of the alimentary system was most common: stomach, liver and large intestine, in that order. There was an increased number of hepatocellular carcinoma closely related to liver cirrhosis. Carcinoma of the lung has increased remarkably in leprosy patients quite recently. Malignant lymphoma was the most common of the nonepithelial malignant tumors, and four of these cases were seen in lepromatous leprosy patients. Eight cases showed double or triple cancers; seven of these were autopsied during 1977 to 1989. Further studies should be done to ascertain which types of leprosy showed the highest incidence, and which sex showed more frequent malignant tumors.

Aged↗

PubMed1990

[Myocardial adrenergic derangement due to myocardial ischemia: decreased myocardial uptake of I-123 metaiodobenzylguanidine after PTCA in a patient with effort angina].

Regional denervation of adrenergic nerves has been clinically demonstrated in patients with myocardial infarction using I-123 metaiodobenzylguanidine (MIBG) scintigraphy. However, it is not clarified whether adrenergic denervation can be induced by prolonged myocardial ischemia as well as by myocardial infarction. This case with effort angina had 99% stenosis of right coronary artery and showed perfusion defects at inferior myocardial regions in the exercise thallium-201 study. However, inferior wall motion estimated by echocardiography and left ventriculography was normal indicating the absence of myocardial infarction. After percutaneous transluminal coronary angioplasty for the stenosis, I-123 metaiodobenzylguanidine (MIBG) and thallium-201 (Tl-201) myocardial scintigraphies were done to estimate the therapeutic effect of PTCA. Although the Tl-201 study during exercise showed normal findings indicating the success of PTCA, marked defects was detected at inferior myocardial regions in the I-123 MIBG studies just after and 4 hours after an intravenous injection of I-123 MIBG. These results suggest that adrenergic derangement may be induced by prolonged myocardial ischemia and may persist for periods even though myocardial perfusion is normalized.

3-Iodobenzylguanidine↗

PubMed1990

[Allopurinol induced aplastic anemia in a patient with chronic renal failure].

A 43 year old female patient with chronic renal failure originated from polycystic kidney disease was admitted with pancytopenia. Prior to the admission, she had a history of taking allopurinol for 3 months. Allopurinol was discontinued immediately and she was treated with blood transfusion (platelet and RBC) and fluoxymesterone. The lymphocyte stimulation tests were negative for allopurinol and oxipurinol. The determination of serum levels of allopurinol and oxipurinol was disclosed to be not so high compared with other patients treated with allopurinol. On 45th day after admission, she was transfused with bone marrow from her elder brother. Thereafter bone marrow finding of the patient began to improve despite the lack of bone marrow engraftment. For further improvement, pulse treatment with corticosteroid was carried out. Although the pathophysiology of allopurinol-induced aplastic anemia remains unknown, it is interesting to note that bone marrow transfusion and pulse treatment with corticosteroid seemed effective in this case.

Adult↗

PubMed1990

[CT findings in bilateral adrenal enlargement].

CT findings in ten patients with bilateral adrenal enlargement (six cases of adrenal metastasis, two cases of malignant lymphoma, one case of pheochromocytoma and one case of adrenal hemorrhage) reviewed. Four of six cases of adrenal metastasis showed asymmetrical adrenal enlargement on initial CT scans. Ring enhancement on postcontrast CT was recognized in one case of adrenal metastasis and one case of adrenal hemorrhage (subacute stage). Ring enhancement in the case of adrenal hemorrhage was more clear and smooth than that in the case of adrenal metastasis. One case of malignant lymphoma and one case of adrenal hemorrhage had Addison's disease.

Adrenal Gland Diseases↗

PubMed1990

[Gallium-67 myocardial imaging for the detection of adriamycin cardiomyopathy].

To detect Adriamycin cardiomyopathy, radionuclide myocardial imagings with Tl-201, Tc-99m pyrophosphate, I-123 metaiodobenzylguanidine and Ga-67 were performed in a 49 year-old-woman receiving Adriamycin (a total dose of 230 mg/m2) for the treatment of breast cancer. This patient demonstrated symptoms of congestive heart failure 2 months after the last intravenous administration. At the period of performing the radionuclide studies, echocardiographic LV ejection fraction (EF) was 22%. Despite severe deterioration of cardiac function, Tl-201 SPECT demonstrated no defect and Tc-99m pyrophosphate (PYP) SPECT demonstrated no positive finding. I-123 metaiodobenzylguanidine (MIBG) scintigraphy demonstrated no regional defect. However, I-123 MIBG washout rate during 4 hours was markedly enhanced, probably reflecting abnormalities of norepinephrine kinetics due to the progression of heart failure. Compared to these pharmaceuticals, Ga-67 was diffusely accumulated in the heart. Then, 5 months after the first study, when LV EF improved to 30% and congestive symptoms disappeared probably owing to beta-blockade therapy, myocardial accumulation of Ga-67 markedly reduced. It has been reported that Ga-67 accumulates in malignant tumor cells and leukocytes. Since, in Adriamycin cardiomyopathy, myocardial accumulation of leukocytes with myocardial fibrotic changes have been histologically demonstrated, the results of Ga-67 scintigraphy may reflect the accumulation of leukocytes. Thus, this case indicates that Ga-67 scintigraphy is advantageous for detecting Adriamycin cardiomyopathy and may be more useful than Tl-201 and Tc-99m PYP scintigraphies.

Doxorubicin↗

PubMed1989

Expansion of natural killer cells but not T cells in human interleukin 2/interleukin 2 receptor (Tac) transgenic mice.

Transgenic mice expressing both human IL-2 and the L chain of IL-2-R constitutively had an unusual expansion of Thy-1+/CD3-4-8- large granular lymphocytes, which bore the elevated NK activity. Unexpectedly, the transgenic mice had neither T cell expansion nor autoreactive antibodies. The increase in number and activity of NK cells seems to be responsible for both the severe interstitial pneumonia and lymphocyte depletion in the spleen that we found in these transgenic mice. In addition, we found the selective loss of Purkinje cells in the cerebellum of the mice, which gave rise to their disturbed gait. All the transgenic mice died by 4 wk of age.

Animals↗

PubMed1989

Effect of dimethylthiourea on syngeneic rodent islet transplantation.

We studied the effects of a hydroxyl radical scavenger, dimethylthiourea (DMTU), on syngeneic islet grafts. Six hundred fresh islets taken from two Wistar rats were transplanted intraportally into other Wistar rats made diabetic with streptozotocin. DMTU was given to five recipients intraperitoneally for a month while nine controls received only intraperitoneal saline. The DMTU-treated group had significantly lower fasting plasma glucose levels at 1.5, 4.5, 5, 5.5, 6, 7, 9 and 11 weeks and had higher mean fasting body weights between the 2.5th week and their eventual sacrifice. Their islets also survived significantly longer than did those of the controls (73.6 +/- 3.4 vs. 21.6 +/- 9.4 days). This suggests that oxygen free radical production endangers graft survival and that the hydroxyl radical scavenger DMTU protects syngeneic islet grafts.

Animals↗

PubMed1989

High-resolution electron microscopy of ceramic interfaces.

Three observations described here were chosen not only to represent our recent interface studies in ceramics, but also to demonstrate how different the present status of interface research is with respect to the level of high-resolution electron microscopy. Certain common features may be found among the problems of ceramic interface studies. Importance of basal plane grain boundary, for example, is one of the characteristics of this type of heterogeneous compound. The crystalline heterogeneity has been ignored largely in the grain boundary structure study since it has been developed primarily for cubic metals. The new area of basic grain boundary interface structure study is opened now that description of this type of interface has become engineeringly important.

Aluminum↗

PubMed1989

A full length cDNA clone for the alkaline protease from Aspergillus oryzae: structural analysis and expression in Saccharomyces cerevisiae.

We have cloned and determined the nucleotide sequence of a cDNA fragment for the entire coding region of the alkaline protease (Alp) from a filamentous ascomycete Aspergillus oryzae. According to the deduced amino acid sequence, Alp has a putative prepro region of 121 amino acids preceding the mature region, which consists of 282 amino acids. A consensus sequence of a signal peptide consisting of 21 amino acids is found at the N-terminus of the prepro region. The primary structure of the mature region shares extensive homology (29%-44%) with those of subtilisin families, and the three residues (Asp 32, His 64 and Ser 221 in subtilisin BPN') composing the active site are preserved. The entire cDNA, coding for prepro Alp, when introduced into the yeast Saccharomyces cerevisiae, directed the secretion of enzymatically active Alp into the culture medium, with its N-terminus and specific activity identical to native Aspergillus Alp.

Amino Acid Sequence↗

PubMed1989

Thermal salivation in rats, anesthetized with barbiturates, chloralose, urethane and ketamine.

1. The relationship between thermal salivation (TS) and thermoregulation was studied in anesthetized rats. 2. Of the 6 anesthetics used, ketamine-anesthetized rats secreted the largest amount of saliva. Salivation, however, was thermal and not induced by ketamine itself. 3. Ketamine-anesthetized rats readily secreted saliva at core temperatures less than 40 degrees C but TS was remarkably enhanced by hyperthermia of 40-42.5 degrees C. 4. The equilibrium phase in the triphasic heat response of core temperature was a consequence of equilibrium between heat gain and heat loss by salivation.

Anesthetics↗

PubMed1989

Effects of the deregulated expression of human interleukin-2 in transgenic mice.

We constructed transgenic mice that carry the cDNA of human interleukin-2 (IL-2) under the control of the H-2Kd promoter. The IL-2 transgenic mice expressed human IL-2 mRNA in the thymus, spleen, bone marrow, lung, muscle and skin. Human IL-2 protein was also detected in their sera. The IL-2 transgenic mice suffered from alopecia and pneumonia, but no typical autoimmune reactions seemed to be involved in these lesions. In the epidermis of the IL-2 transgenic mice there was an increase in Thy-1+ dendritic epidermal cells (DEC), which might be involved in the skin lesion. Immune responses of their spleen cells against antigens were significantly impaired whereas their spleen cells responded well to polyclonal lymphocyte activators.

Alopecia↗