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Biomedical subjects

K Azuma

Publications and source records attributed to K Azuma.

At least 37 records · Page 2Linked to original sources
PubMed1990

Effect of 2-buten-4-olide, an endogenous suppressant of feeding, on reproductive function in rats.

The effects of 2-buten-4-olide, an endogenous feeding suppressant, on the estrous cycle and LH secretion were studied to determine the influence of this compound on reproductive function. Estrous cycling female Wistar rats were treated ip with 2-buten-4-olide (0, 30 or 100 mg.kg-1.day-1) for 2 weeks. Treatment with 100 mg.kg-1.day-1 delayed the estrous cycle. 2-Buten-4-olide increased the pituitary content of LH (1651.3 +/- 164.4 vs 927.7 +/- 65.1 ng/pituitary; p less than 0.01), and decreased the serum LH level compared with the control level in diestrus (0.16 +/- 0.01 vs 0.26 +/- 0.03 microgram/l; p less than 0.05). However, it did not affect the GnRH content of the mediobasal hypothalamus. The direct effects of 2-buten-4-olide on the pituitary response to GnRH was examined by perifusing the pituitary. Medium containing 2-buten-4-olide (10(-4) mol/l) suppressed the pituitary response to GnRH (2 micrograms/l) (percent increase at 50 min after start of GnRH stimulation: 180 +/- 47 vs 406 +/- 66%; p less than 0.05). These findings suggest that 2-buten-4-olide is involved in the regulation of pituitary gonadotropin secretion directly by suppressing the pituitary responsiveness to GnRH, and that 2-buten-4-olide may play an important role in starvation-induced anestrus.

4-Butyrolactone↗
PubMed1990

[Two cases of pulmonary leiomyosarcoma].

Pulmonary sarcoma is a rare tumor of the lung. There are 81 cases in the literature for review, including our two cases. Our first case who was a thirty-seven year old male who was admitted to our hospital with complaints of left back pain. His chest X-ray showed an 11 X 14 cm tumor shadow in the lower left lung area. A left upper lobectomy was performed, and the histological diagnosis was leiomyosarcoma of the pulmonary vein. He died due to mediastinal recurrence 29 months later. Our other case was a fifty-six year old female. Her chest X-ray showed an abnormal shadow that was a tumor shadow in the right central lung area of 4 cm in diameter. As the diagnosis of the transcutaneous lung biopsy was benign tumor, partial resection of lung was performed. The histological diagnosis was leiomyosarcoma of the bronchus, and she is alive and well at 29 months after the operation. As the rate of diagnosis in leiomyosarcoma detected by transcutaneous lung biopsy is low, the most acceptable method of diagnosis is a total examination, including cytology of sputum, bronchoscopic findings, and roentgenoscopy. Probe thoracotomy would also be necessary if malignancy could not ruled out. The treatment of lobectomy should include lymph node resection.

Adult↗
PubMed1989

[A case of bilateral multiple lung cancer resected by synchronous bilateral thoracotomy].

A 59-year-old female with multiple lung cancer, located in left upper lobe and in right upper lobe received synchronous bilateral thoracotomy. The patient underwent left upper division segmentectomy and right S3 segmentectomy. Histological examination showed large cell carcinoma in the left side and small cell carcinoma in the right side. The patient died 5 years and 3 months after operation. If general condition and pulmonary function permit, bilateral thoracotomy for multiple lung cancer is recommended.

Carcinoma, Small Cell↗
PubMed1989

[Investigation on antibodies to human T cell leukemia virus type I in patients with primary glomerulonephritis].

We investigated on antibodies to human T cell leukemia virus type I (anti HTLV-I) in 101 patients with primary glomerulonephritis in Kagoshima prefecture, an endemic area of HTLV-I in Japan. The positive rate in patients with primary glomerulonephritis was 17.8%, which was not significantly higher than in healthy residents 4741 persons of 11.9% in the same area. Classified by renal biopsy findings, the positive rate in patients with membranous nephropathy was 21.4% (9/42), minimal change nephrotic syndrome 14.3% (2/14), IgA nephropathy 15.4% (2/26), and others 15.8% (3/19) respectively, which were not significantly differed from that in healthy residents. Positivity of aged patients (60 years or over) in membranous nephropathy on the contrary was significantly higher than that in healthy residents (p less than 0.01). Further study is required to clarify the relationship between HTLV-I infection and glomerulonephritis.

Adolescent↗
PubMed1989

[A case of pulmonary arteriovenous fistula with mitral stenosis].

The patient was a 61-year-old female, complaining of cyanosis, dyspnea and shortness of breath on exertion. She was diagnosed as having a pulmonary arteriovenous fistula (PAVF) in combination with mitral stenosis. The fistula was located in the left lower lobe and a right-left shunt of 28.7% was detected. Cardiac catheterization showed a pulmonary artery pressure of 44/22 mmHg (mean pressure, 31 mmHg). By occluding the PAVF using a balloon catheter, PaO2 increased from 47 mmHg to 88 mmHg. The mitral stenosis of this patient was though to be a mild form, and PAVF seemed to be responsible for symptoms. Since left lobectomy together with mitral valve replacement was considered to have a high risk, left lower lobectomy was performed initially. Thereafter mitral valve replacement was done successfully. Separate operations for PAVF and mitral stenosis are likely to be beneficial in patients with mitral stenosis associated with moderate pulmonary hypertension.

Arteriovenous Fistula↗
PubMed1989

[Anemia in patients on continuous ambulatory peritoneal dialysis (CAPD)].

Inhibitors of erythropoiesis found in the blood of uremic patients have been implicated as some of the causes of anemia in chronic renal failure. As a treatment to remove the inhibitors, continuous ambulatory peritoneal dialysis (CAPD) is thought to be more effective than hemodialysis. Some researchers have reported that CAPD has improved anemic state in hemodialysis patients. However, there have been some cases of severe anemia seen in CAPD patients. To access the effect of the CAPD, we have performed serial examination on hemoglobin (Hb) and hematocrit (Ht) in 5 uremic patients under CAPD treatment. Hb levels in 4 and Ht in 3 of 5 patients have been known to be increased. One patient was shown to have no increment on the levels of Hb and Ht. On the other hand, further investigation has been down to access the effect of the recombinant human erythropoietin (r-HuEPO: Chugai pharmaceutical) on anemic patients, in whom no effect was noticed by treatment of CAPD. One severe anemic patient, who had been undergoing the treatment of CAPD for two years, was given r-HuEPO intravenously. The patient showed the increment on the levels of Hb and Ht, and the decreases on the levels of serum iron and ferritin. However, the patient has developed hypertension. In conclusion, CAPD was known to be not always effective for the increment of Hb and Ht, while r-HuEPO was very effective for the improvement of severe anemia in CAPD patients which enabls them to lead better social life for them.

Adult↗
PubMed1988

Three distinct forms of type 2A protein phosphatase in human erythrocyte cytosol.

Two type 2A protein phosphatases, phosphatases I (Mr = 180,000) and III (Mr = 177,000), were purified to near homogeneity from human erythrocyte cytosol. Phosphatase I was composed of alpha (34 kDa), beta (63 kDa), and delta (74 kDa) subunits in a ratio of 1:1:1. Phosphatase III comprised alpha, beta, and gamma (53 kDa) subunits in the same ratio. Heparin-Sepharose column chromatography converted most of phosphatase I and 20% of phosphatase III into alpha 1 beta 1 which were indistinguishable from phosphatase IV (Usui, H., Kinohara, N., Yoshikawa, K., Imazu, M., Imaoka, T., and Takeda, M. (1983) J. Biol. Chem. 258, 10455-10463). The catalytic subunit alpha and the beta subunit of phosphatases I, III, and IV displayed identical V8 and papain peptide maps, respectively, while the peptide maps of the alpha, beta, gamma, and delta subunits were clearly distinct. The molar ratio of phosphatases I, III, and IV in erythrocyte cytosol was estimated to be 6:1:14. Comparison of molecular activities of alpha, alpha 1 beta 1, alpha 1 beta 1 delta 1, and alpha 1 beta 1 gamma 1 revealed that beta suppressed phosphorylase and P-H2B histone phosphatase activities of alpha but stimulated the P-H1 histone phosphatase activity, and delta suppressed all the phosphatase activities of alpha 1 beta 1. The gamma subunit stimulated the P-histone phosphatase activity of alpha 1 beta 1 but inhibited the phosphorylase and P-spectrin phosphatase activities. The beta subunit increased the Mg2+ or Mn2+ requirement for P-H2B histone phosphatase activity of alpha, an effect which was counteracted by delta. The effects of heparin, H1 histone, protamine, and polylysine on the phosphorylase phosphatase activity of phosphatases I, III, IV, and alpha were described and discussed in connection with the functions of the subunits.

Cytosol↗
PubMed1988

Tyrosine protein kinases in membrane fractions from rat cerebral cortex.

Specific activities of tyrosine tubulin kinase in the particulate fractions from rat cerebellum, medulla oblongata, hypothalamus, striatum, midbrain, and cerebral cortex ranged within 30% of each other and more than 3 times higher than those in the soluble fractions. In the cerebral cortex, tyrosine protein kinase activity toward tubulin and tyrosine-glutamate (1:4) copolymers was mainly distributed in the plasma membrane and the microsome fractions. The kinase activity in cerebral cortex particulate fractions was quantitatively solubilized and separated into two peaks, kinase I and kinase II, by Sephacryl S-300 gel filtration in the presence of 0.2% Nonidet P-40 and 0.2 M NaCl. Kinases I and II were each resolved into 5 active peaks (I-1----5 and II-1----5) by casein-Sepharose column chromatography. The molecular weights of these kinases were estimated from the s20,w values to be 59,000-65,000. The Km values of II-1----5 for tubulin were nearly 10 times higher than those of I-1----5. However, the Km values of the two groups of kinases for tyrosine-glutamate copolymers were not so significantly different. About 60% of the copolymers kinase activity in I-3, I-4, II-3, and II-4 was immunoprecipitable with a saturating amount of monoclonal antibody against pp60c-src. Incubation of the immunoprecipitates with ATP resulted in the autophosphorylation of a 60 kDa protein in I-3 and I-4, and a 52 kDa protein in II-3 and II-4. Immunoblotting also indicated I-3 and I-4 as 60 kDa bands and II-3 and II-4 as 52 kDa bands on SDS-polyacrylamide gels.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Retinoid changes in the in vitro regeneration of frog visual pigments.

To investigate the regeneration of visual pigment, the changes in composition and quantity of retinoids were measured by high-performance liquid chromatography (HPLC). Eye cups or eye cup sections of dark-adapted frogs were exposed to light (greater than 500 nm) and incubated in the dark for several hours (pH 7.4, 27 +/- 1 degree C). Retinoids extracted by the oxime method before and after illumination were analysed by HPLC. In the dark, every eye cup or eye cup section contained 11-cis and all-trans isomers of retinyl palmitate (the proportion of 11-cis was nearly 40%). The amount of retinyl palmitate was 1-1.5 mol equiv of visual pigment. After 80% of the visual pigment had been bleached by illumination, eye cups or eye cup sections were incubated in the dark for 10 h. During the incubation, 70% of the bleached pigment was regenerated, and the proportion of 11-cis retinyl ester decreased from 40% to 13%. These results indicate that stored 11-cis retinyl ester is used for the regeneration. The regeneration rate of A2-pigment (half time = 75 min) was faster than that of A1-pigment (half time = 90 min), consistent with the result of Tsin & Flores' (1986) in vivo experiment with goldfish.

Animals↗