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Biomedical subjects

T Iwai

Publications and source records attributed to T Iwai.

At least 199 records · Page 11Linked to original sources

Intra-operative monitoring of the pelvic circulation using a transanal Doppler probe.

The authors have developed a new device to examine the pre-, intra-, and postoperative pelvic blood flow, consisting of a plastic rectoscope with a commercially available 10 MHz flat Doppler probe mounted at the tip surrounded in use by a thin, acoustic gel filled condom and inserted transanally. Blood flow in the superior rectal artery can easily be detected in this way through the posterior wall of the rectum. The authors have used this technique in 70 patients, 49 undergoing abdominal aortic aneurysmectomy and 21 aorto-femoral bypass surgery. In all cases following clamping of the infrarenal aorta a synthetic bifurcated graft was anastomosed usually to the aorta using an end-to-end or end-to-side anastomosis. Immediately after application of the aortic clamp the Doppler recorder was started in order to determine the time when rectal blood flow reappeared. In the superior mesenteric artery dominant group, a good pulse wave was seen within 15 min of clamping and 88% of the aneurysm and 62% of the aorto-iliac patients fell into this group. Fourteen patients in this group underwent triple vessel ligation (bilateral internal iliac and inferior mesenteric arteries) without any postoperative colonic ischaemia. In an additional study consisting of eight patients with vasculogenic impotence and/or hip claudication, the effectiveness of surgery was assessed by the increase in amplitude of the Doppler signals following reconstruction of the internal iliac artery. Following successful internal iliac reconstruction, an improvement in the amplitude of the waveform could be observed and followed postoperatively. In conclusion, the transanal Doppler probe can be used to follow the adequacy of the pelvic circulation allowing safer aorto-iliac and aorto-femoral surgery.

Aged↗

Effects of long term treatment with an alpha 1 adrenoceptor blocker on cardiac hypertrophy, contractility, and myosin isoenzymes in spontaneously hypertensive rats.

STUDY OBJECTIVE: The aim was to investigate the effects of long-term treatment with an alpha 1 blocker, bunazosin hydrochloride, on blood pressure, heart weight, myocardial contractility, and ventricular myosin isoenzyme pattern in spontaneously hypertensive rats (SHR). DESIGN: Bunazosin hydrochloride was given orally in a dose of 10 mg.kg-1.d-1 for 8-9 weeks. Isometric tension development was measured in isolated left ventricular papillary muscles. The left ventricular myosin isoenzyme pattern was determined by pyrophosphate gel electrophoresis. SUBJECTS: 14 male SHR (seven treated and seven untreated rats) aged 23 to 24 weeks were studied. MEASUREMENTS AND MAIN RESULTS: The blood pressure of the bunazosin treated rats was approximately 14% lower than that of the untreated rats at the end of the treatment period. The ventricular weight of treated SHR was significantly lower (around 8%) than that of untreated rats, but there were no significant differences between the two groups in the mechanical data obtained from isolated left ventricular papillary muscles. The myosin isoenzyme pattern of the left ventricle was significantly shifted toward VM-1 in the bunazosin treated SHR, the VM-1 concentration in the treated group being 38% greater than in the untreated group. CONCLUSIONS: These results indicate that long term treatment with bunazosin hydrochloride reduces blood pressure and leads to the regression of cardiac hypertrophy in SHR. Myocardial energetics (as represented by the myosin isoenzyme pattern) were affected, but there was no influence on myocardial tension development.

Adrenergic alpha-Antagonists↗

A protein-bound polysaccharide from Basidiomycetes enhances myosin phosphorylation but inhibits myosin ATPase activity: studies with a crude actomyosin preparation of chicken gizzard smooth muscle.

Chicken gizzard actomyosin, containing the calmodulin-myosin light chain kinase (MLCK) system, was incubated in the presence of various concentrations of PSK, a protein-bound polysaccharide from Basidiomycetes, together with Ca2+ and Mg-ATP. The phosphorylation of myosin was enhanced half-maximally by 10-4 g/ml of PSK. However, a similar concentration of PSK reduced the Mg-ATPase activity of the actomyosin. The former was brought about through stimulation of the MLCK activity and the latter through inhibition of the myosin ATPase activity.

Actomyosin↗

Incidence and characterization of Staphylococcus aureus from the tongues of children.

Three hundred and seven children who had no diseases other than dental disease were examined for their oral carriage of Staphylococcus aureus, the most common persistent human pathogen. Eighty-four percent of them were positive for staphylococci, and 33% were positive for S. aureus. Among the 100 strains of S. aureus isolated, 40 strains produced enterotoxin, and 19 strains produced exfoliative toxin. Their susceptibility to antibiotics was also investigated: Six strains demonstrated resistance to methicillin (MIC greater than or equal to 12.5 microgram/mL), and 50% of the isolates were borderline resistant (MIC of 3.13 to 6.25 micrograms/mL) to the drug. These data suggest that the mouths of children could be reservoirs of pathogenic S. aureus.

Child, Preschool↗

Luteinizing hormone induces progesterone receptor gene expression in cultured porcine granulosa cells.

We have examined the effect of LH on the regulation of the progesterone receptor (PR) in cultured porcine granulosa cells. In this study we used the RNase protection assay to evaluate the PR mRNA levels with a porcine cDNA clone isolated by the polymerase chain reaction (PCR) method. This clone was regarded as part of the porcine PR cDNA because of its 98.3% and 95.7% homology to the hormone-binding domain of human PR cDNA in amino acid and nucleotide sequences, respectively. Treatment with LH (500 ng/ml) increased porcine PR mRNA to a maximum level of 8.6 +/- 1.1-fold (mean +/- SE) after 3-h exposure. This induction was mimicked by (Bu)2cAMP as well as by FSH and hCG, and the increased PR caused by LH and (Bu)2cAMP occurred in a dose-dependent manner. Basal and LH-induced PR mRNA levels were not affected by progesterone (100 ng/ml), estrogen (100 ng/ml), and RU 486 (10 ng/ml) at 3 h. The mechanism of the increased PR mRNA levels was studied in the presence of actinomycin-D and cycloheximide. While inhibition of RNA synthesis with actinomycin-D blocked LH-induced PR mRNA expression, inhibition of protein synthesis with cycloheximide increased basal and LH-induced PR mRNA levels. These results indicate that the expression of PR mRNA is positively regulated by LH, and this induction does not require ongoing protein synthesis. There may be a cycloheximide-sensitive mechanism that modulates PR mRNA stability. From our results we suspect that progesterone modulates ovarian function through LH-induced PR in granulosa cells.

8-Bromo Cyclic Adenosine Monophosphate↗

Effect of human chorionic gonadotropin on the expression of progesterone receptors and estrogen receptors in rabbit ovarian granulosa cells and the uterus.

To investigate whether LH/human CG (hCG) or progesterone acts as a regulator of estrogen receptors (ER) and progesterone receptors (PR) in granulosa cells, we studied the immunohistochemical expression of both ER and PR in the ovary and the uterus of mature rabbits, during the induction of ovulation by FSH followed by administration of hCG, progesterone, or a progesterone antagonist (RU486) and hCG. Granulosa cells pretreated with FSH for 3 days showed ER staining, but negligible PR staining. The staining pattern for ER and PR changed in animals pretreated with FSH followed by hCG injection; by 6 h after hCG injection, we observed the disappearance of ER and the appearance of PR, and by 3 days after hCG injection, we observed the reappearance of ER and the disappearance of PR. However, the expression of ER and PR in the granulosa cells of animals pretreated with FSH followed by progesterone administration instead of hCG was almost the same as that of animals pretreated with FSH alone. In addition, the expression of ER and PR in the granulosa cells of animals pretreated with FSH followed by RU486 and hCG was almost the same as that of animals pretreated with FSH followed by hCG administration. The uterine glandular epithelium, in contrast, began to show decreased appearance of ER and PR by 48 h after hCG injection, and we observed the disappearance of both receptors by 3 days after hCG administration. These results suggest that the expression of ER and PR in granulosa cells is not regulated by the action of progesterone, but by that of LH/hCG.

Animals↗

Functional structure of protein: exposed vs hidden function.

The dev analysis was used to construct the functional structure of protein (3). Based on this principle, the intramolecular interaction of dev peak was investigated. Two types of peak were observed: one is the hidden peak which interacts strongly with another region of the molecule and the other is the exposed peak whose interaction was weak. Analysis was made with trypsin and its inhibitor and on the intermolecular interaction between their exposed peaks. One interaction between their exposed peaks was found to coincide with one which had been already known to be authentic between their active sites.

Amino Acid Sequence↗

Isolation of chicken-bek and a related gene; identification of structural variation in the ligand-binding domains of the FGF-receptor family.

cDNA clones carrying the chicken-bek gene and a related gene were isolated. Deducing the amino acid sequence of chicken-bek allowed us to predict that it encodes for a receptor tyrosine kinase related to the fibroblast growth factor (FGF) receptor, and that the chicken-bek gene and Cek3 are closely related. However, a significant structural difference was identified between chicken-bek and Cek3 within the putative extracellular region, in such a manner that the structure of the immunoglobulin-like domain was conserved. A probe specific to the altered structure detected mRNA in the tissues as did a probe common to bek and Cek3, indicating heterogeneity in the FGF-receptor family in a novel manner. Furthermore, another bek-like gene was isolated and the expressions of its mRNA and protein product were analysed in tissues and cultured cells.

Amino Acid Sequence↗

[Clinico-pathological study of cervical carcinoma with massive infiltration of eosinophils].

Eight patients with cervical carcinoma with massive stromal infiltration of eosinophils were selected for a clinicopathological study among 474 patients with cervical carcinoma at stages Ib-IIIb who underwent radical hysterectomy between 1971 and 1989 at Kyoto University Hospital. The 8 patients ranged in age from 28 to 48 years and had menstrual cycles. The peripheral leucocyte count in 5 patients showed eosinophilia of the peripheral blood. Histologically, the cervical carcinoma was a locally advanced tumor with invasion of more than 2/3rds the depth of the cervical wall in 6 cases, and with parametrial involvement in 4 cases. Massive infiltration of eosinophils was observed not only around the cancer nests but also within the regional lymph nodes. Mast cells expressing immunoreactivity for histamine were scarce around the tumor. Consequently, the production of an eosinophil chemotactic factor by the tumor cells was strongly suggested. PAS and Alcian-blue staining as well as electron microscopy revealed that the tumor cells in most cases had the histological characteristics of both squamous carcinoma and adenocarcinoma. Collectively, these clinicopathological characteristics of cervical carcinoma with massive infiltration of eosinophils distinguish this tumor from conventional cervical carcinomas.

Adenocarcinoma↗

Immunohistochemical localization of oestrogen receptors and progesterone receptors in the human ovary throughout the menstrual cycle.

Immunohistochemistry was used to determine the distribution of oestrogen receptors (ER) and progesterone receptors (PR) in the human ovary during folliculogenesis. Primordial and preantral follicles did not contain ER or PR. The granulosa cells of antral follicles had ER, but negligible PR, before the LH surge. In contrast, at the time of LH surge, these cells of the dominant follicle contained PR, but not ER. On the other hand, granulosa cells of the non-dominant follicles had ER, but not PR. After ovulation, the PR persisted in the luteinized granulosa cells and in the corpus luteum during early pregnancy. The theca interna and surrounding stromal cells were ER-negative and PR-positive throughout the menstrual cycle. Thus, the results show that ER and PR are not expressed simultaneously in the granulosa cells, the thecal cells, or the stromal cells during folliculogenesis. Mechanisms controlling the expression of steroid receptors during the normal menstrual cycle and in early pregnancy are discussed.

Adult↗

Protein kinase C in Saccharomyces cerevisiae: comparison with the mammalian enzyme.

Protein kinase C (PKC) was detected in the yeast Saccharomyces cerevisiae with bovine myelin basic protein as the phosphate acceptor. The enzyme was purified at least 500-fold by a four-step column chromatographic procedure (phenyl-Sepharose CL-4B, Mono Q, Heparin-5PW, and hydroxyapatite). The molecular mass was approximately 90 kDa, as estimated by gel-filtration analysis. Yeast PKC was activated by the simultaneous addition of Ca2+, diacylglycerol, and phosphatidylserine. Free arachidonic acid alone could activate the enzyme to some extent. However, yeast PKC did not respond significantly to tumor-promoting phorbol esters. GTP did not serve as phosphate donor. The yeast enzyme showed substrate specificity distinctly different from that of mammalian PKCs. H1 histone and protamine were poor substrates. With myelin basic protein as a model substrate, yeast PKC phosphorylated threonyl residues preferentially, whereas rat brain PKCs phosphorylated seryl residues preferentially. Further studies should elucidate the role of yeast PKC in cellular regulation and cell cycle control.

Amino Acid Sequence↗

Significance and actual status of the dissection of paraaortic lymph nodes in the cases with gastric cancer.

The results of the surgical resection of the paraaortic lymph nodes metastases of the gastric cancer were evaluated in 116 cases. The frequency of the dissection of paraaortic lymph nodes (No. 16 lymph node) was 20%; the metastatic ratio was 24%. When classified by regions, the highest frequency of metastasis was observed in the cases of upper gastric cancer. The effect of the dissection of No. 16 was more conspicuous when No. 16 metastases were absent than when No. 16 metastases were present. Particularly, the prognosis was improved in the case of n1 and n2 population of the cases which were positive with respect to the proximal lymph node metastasis. It appears altogether that the dissection has considerable significance as prophylactic treatment.

Aorta↗

Comparison of arteriosclerosis obliterans of lower limbs between China and Japan.

Clinical data on 50 patients with arteriosclerosis obliterans (ASO) in China (Group A) and Japan (Group B) respectively were studied for better understanding of these changing trends. The results showed that the incidence of ASO peaked in Group A in the 50 to 69 age range (88%) and in Group B in the 55 to 74 age range (78%). Group A had a lower ratio of smokers and cases of diabetes mellitus than Group B but a higher ratio of hypertension and a higher total cholesterol level. Angiography showed that the prevalence of atherosclerotic lesions in the lower extremities as a whole was similar for both groups. They were different in location, extent and severity of the arteries involved between the two groups. We believe that this study has shown various differences between the two groups but that the causes are probably multifactorial.

Age Factors↗

Insulin-like growth factor I (IGF-I) enhances hyaluronic acid synthesis in rabbit pericardium.

We examined which substances stimulate hyaluronic acid synthesis in rabbit pericardium and pericardial cells. (1) The addition of 10% (v/v) pericardial fluid to the incubation medium of the pericardium enhanced hyaluronic acid synthesis to about 2.5-times over the control, suggesting that there were some stimulating factors of the hyaluronic acid synthesis in the pericardial fluid. (2) The addition of 100 ng/ml insulin-like growth factor-I (IGF-I) to the incubation medium caused an approx. 2-fold increase of hyaluronic acid synthesis over the control in the pericardium. (3) IGF-I stimulated the hyaluronic acid synthesis in pericardial cells in a dose-dependent manner, but did not significantly stimulate the sulfated glycosaminoglycan synthesis. (4) The increase in the hyaluronic acid synthesis induced by IGF-I (100 ng/ml) or pericardial fluid was blocked by the copresence of monoclonal anti-IGF-I antibody. (5) IGF-I caused possible induction of the hyaluronic acid synthase activity and general protein and RNA synthesis before the initiation of DNA synthesis in pericardial cells. These results suggest a new biological action of IGF-I that stimulates hyaluronic acid synthesis in pericardium or the pericardial cavity of heart.

Animals↗

The assessment of pelvic circulation after internal iliac arterial reconstruction: a retrospective study of the treatment for vasculogenic impotence and hip claudication.

The standard surgical treatment of vasculogenic impotence or hip claudication involves repairing vascular lesions, especially in the internal iliac arteries. It is difficult, however, to make a definite diagnosis or an accurate judgement of the therapeutic effects of this treatment due to the trouble in ruling out any other disorders. During the last five years, 19 patients with impotence and associated apparent internal iliac artery stenosis or occlusion and 2 patients with hip claudication, underwent internal iliac arterial reconstruction. The patients' ages ranged from 37 to 70 with a mean age of 63.7 and the main procedure performed in all patients was aorto-iliac to femoral bypass grafting, or abdominal aortic aneurysmectomy. A retrospective study revealed that 74 per cent of those treated regained penile erectile activity postoperatively, and that hip claudication disappeared completely in all cases. One of the patients received percutaneous transluminal angioplasty (PTA) for the treatment of vasculogenic impotence, after which his postoperative penile brachial pressure index (PBPI) improved, demonstrating a statistically significant difference compared to the preoperative value. Trans-anal Doppler measurement also proved useful in providing complication-free perioperative understanding of pelvic circulation.

Adult↗

Modulation of porcine granulosa cell functions by interleukin-1.

Increasing evidence suggests that functions of the immune system and gonads are closely related with each other. In cultures of granulosa and luteal cells, macrophages have been shown to modulate steroidogenic functions. In this paper we present the modulatory effects of interleukin-1, a cytokine produced predominantly by activated macrophages, on gonadotropin-induced differentiation, as well as growth of cultured porcine granulosa cells.

Animals↗