Biomedical subjects

M Yada

Publications and source records attributed to M Yada.

18 recordsLinked to original sources

PubMed2004

[Intraaortic balloon pumping in patients undergoing coronary artery bypass grafting].

UNLABELLED: Beneficial effect of preoperative intraaortic balloon pumping (IABP) treatment in high-risk patients who had open heart surgery have been demonstrated. The purpose of this study is to determine the impact of preoperative IABP use on survival in high-risk patients undergoing coronary artery bypass grafting (CABG). METHODS: Two hundred seventy-seven consecutive patients having CABG at our institution were reviewed. Patients having an IABP were identified retrospectively and grouped into one of 3 groups as follows. Group A (n = 14): preoperative IABP for high-risk urgent or elective cases. Group B (n = 26): preoperative IABP for emergency cases. Group C (n = 6): unplanned intraoperative or postoperative IABP. RESULTS: Forty-six patients had an IABP (16.6% of total). Parsonnet score in group B was significantly higher (p < 0.05). Length of operation for group C was significantly longer (p < 0.05). Overall hospital mortality in the total group of 277 cases was 4.2%. Hospital mortality was 7.1% in group A, 7.7% in group B, and 50% in group C. Hospital mortality in group C was significantly higher (p < 0.01). CONCLUSIONS: The beneficial effect of preoperative treatment with IABP in high-risk patients undergoing CABG was confirmed. This approach resulted in a significantly lower hospital mortality.

Aged↗

PubMed2003

[Left ventricular-right atrial communication detected by pregnancy; report of a operative case].

A 24-year-old pregnant female was admitted to our hospital because of congestive heart failure. When she was 3 month old, she underwent closure of patent ductus arteriosus. Echocardiography, cardiac catheterization and selective angiocardiography showed a left ventricular-right atrial shunt. At the operation, we found a left ventricular right-atrial communication (group I) and repaired the defect directly. The patient was discharged and returned to her social life.

Adult↗

PubMed2003

[Preoperative autologous blood donation in patients undergoing open heart surgery].

We examined the possibility to avoid the homologous blood transfusion in patients undergoing open heart surgery by predonation of 200 ml or 400 ml on the day before operation. Between March 1999 and December 2001, 117 patients underwent scheduled open heart surgery. In these patients, preoperatively collected autologous blood on the day before operation amounted 200 ml or 400 ml. We divided these patients into 3 groups according to the necessity of homologous blood, no transfusion (group A, n = 77), intraoperative transfusion (group B 1, n-29) and postoperative transfusion (group B 2, n = 11). In 65.8% of patients the homologous blood transfusion could be avoided. Preoperative, intraoperative and postoperative factors were compared in the 3 groups. Especially, old age, female, body weight and preoperative hemoglobin value were significantly different between 3 groups. Postoperative Svo2 and postoperative hemoglobin value were significantly different between 3 groups. The purpose of this study was to evaluate that the predonation of 200 ml or 400 ml on the day before operation may be to avoid the homologous blood transfusion and that preoperative, intraoperative and postoperative factors in regard to homologous blood transfusion.

Age Factors↗

PubMed2002

[Results of surgical treatment for thymic epithelial tumors with special reference to the WHO classification].

We examined the clinical significance of World Health Organization (WHO) classification based on a surgical experience with 71 patients. There were 6, 21, 6, 10, 14, and 14 patients with type A, AB, B1, B2, B3 and C tumors. In these patients, average stage by Masaoka's classification was significantly associated with the WHO classification. Invasive tumors of stage III and IV were seen more frequently in patients with type B2, B3 and C tumors than in those with type A, AB and B1. The incidence of tumors invading the lung, the pericardia or the pleura was higher in type B2, B3 and C than in type A, AB or B1. Furthermore, tumor recurrences and tumor-related deaths were seen only in patients with type B2, B3 or C. This study suggested that type B2, B3 and C tumors had more malignant nature in terms of invasiveness, recurrence and prognosis following operation, and that WHO classification may be a useful guideline for planning treatment of thymic epithelial tumors.

Adult↗

PubMed2001

U box proteins as a new family of ubiquitin-protein ligases.

The U box is a domain of approximately 70 amino acids that is present in proteins from yeast to humans. The prototype U box protein, yeast Ufd2, was identified as a ubiquitin chain assembly factor that cooperates with a ubiquitin-activating enzyme (E1), a ubiquitin-conjugating enzyme (E2), and a ubiquitin-protein ligase (E3) to catalyze ubiquitin chain formation on artificial substrates. E3 enzymes are thought to determine the substrate specificity of ubiquitination and have been classified into two families, the HECT and RING finger families. Six mammalian U box proteins have now been shown to mediate polyubiquitination in the presence of E1 and E2 and in the absence of E3. These U box proteins exhibited different specificities for E2 enzymes in this reaction. Deletion of the U box or mutation of conserved amino acids within it abolished ubiquitination activity. Some U box proteins catalyzed polyubiquitination by targeting lysine residues of ubiquitin other than lysine 48, which is utilized by HECT and RING finger E3 enzymes for polyubiquitination that serves as a signal for proteolysis by the 26 S proteasome. These data suggest that U box proteins constitute a third family of E3 enzymes and that E4 activity may reflect a specialized type of E3 activity.

Amino Acid Sequence↗

PubMed2001

The SOCS box of SOCS-1 accelerates ubiquitin-dependent proteolysis of TEL-JAK2.

Fusion of the TEL gene on 12p13 to the JAK2 tyrosine kinase gene on 9p24 has been found in human leukemia. TEL-mediated oligomerization of JAK2 results in constitutive activation of the tyrosine kinase (JH1) domain and confers cytokine-independent proliferation on interleukin-3-dependent Ba/F3 cells. Forced expression of the JAK inhibitor gene SOCS1/JAB/SSI-1 induced apoptosis of TEL-JAK2-transformed Ba/F3 cells. This suppression of TEL-JAK2 activity was dependent on SOCS box-mediated proteasomal degradation of TEL-JAK2 rather than on kinase inhibition. Degradation of JAK2 depended on its phosphorylation and its high affinity binding with SOCS1 through the kinase inhibitory region and the SH2 domain. It has been demonstrated that von Hippel-Lindau disease (VHL) tumor-suppressor gene product possesses the SOCS box that forms a complex with Elongin B and C and Cullin-2, and it functions as a ubiquitin ligase. The SOCS box of SOCS1/JAB has also been shown to interact with Elongins; however, ubiquitin ligase activity has not been demonstrated. We found that the SOCS box interacted with Cullin-2 and promoted ubiquitination of TEL-JAK2. Furthermore, overexpression of dominant negative Cullin-2 suppressed SOCS1-dependent TEL-JAK2 degradation. Our study demonstrates the substrate-specific E3 ubiquitin-ligase-like activity of SOCS1 for activated JAK2 and may provide a novel strategy for the suppression of oncogenic tyrosine kinases.

Animals↗

PubMed1999

Mesoporous Magnetic Materials Based on Rare Earth Oxides.

A novel family of mesoporous oxides of rare earth metals (Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) were synthesized with specific surface areas of 253-348 m(2) g(-1) and pore diameters of 2.5-3.0 nm (see Scheme). The mesoporous solids and their surfactant mesophase precursors are paramagnetic and exhibit a magnetic anomaly due to the mesostructured atomic arrangement.

Journal Article↗

PubMed1999

4-Phenylthiazole derivatives inhibit IL-6 secretion in osteoblastic cells and suppress bone weight loss in ovariectomized mice.

A series of 4-phenylthiazole derivatives were synthesized and tested their inhibitory effect on the interleukin-6 secretion stimulated by PTH in osteoblastic cells. SCRC2941-18, 2-amino-4-(4-chlorophenyl)-5-methylthiazole, was found to be the most potent inhibitor in the derivatives. Furthermore, SCRC2941-18 significantly suppressed the bone weight loss in the ovariectomized mice, an osteoporosis model.

Animals↗

PubMed1999

Suppressive effect of norzoanthamine hydrochloride on experimental osteoporosis in ovariectomized mice.

Norzoanthamine is an alkaloid isolated from a colonial zoanthid. We examined the effects of norzoanthamine hydrochloride on bone weight, strength and morphology in ovariectomized mice, a postmenopausal osteoporosis model. Norzoanthamine hydrochloride significantly suppressed the decrease in femoral weight and bone biomechanical parameters caused by ovariectomy without an increase in uterine weight. This means that norzoanthamine hydrochloride does not have an estrogen-like effect on reproductive organs. Morphological observations of longitudinally ground sections of the humeri showed that norzoanthamine hydrochloride administration (2 mg/kg/d, p.o.) completely suppressed the loss of trabecular bone. Furthermore, norzoanthamine hydrochloride thickened the cortical bone. Based on these results, norzoanthamine hydrochloride may act as both a suppressor of bone resorption and an enhancer of bone formation in vivo.

Alkaloids↗

PubMed1997

An evaluation of crystal structure of mannan I by X-ray powder diffraction and molecular mechanics studies.

The present study reports the re-examination of the crystal structure of mannan I by the X-ray powder diffraction study combined with the miniature crystal model simulation. A primary objective of this study was to investigate an adequate chain staggering position along the fiber axis. Among the several crystal structure models proposed for mannan I, that derived from the electron diffraction study of the single crystals was adopted as a starting model. The X-ray crystallographic residuals were calculated for the single crystal structure at different chain staggering positions, while the ab projection was kept invariant. In a similar fashion, the miniature crystal models consisting of seven mannotetraoses were constructed, each having different chain staggering values and the three-dimensional structures of all the models were subsequently optimized by using the MM3(92) program without introducing any constraint. Both the X-ray residual and lattice energy plots with respect to the chain staggering position showed the common minima around the -0.25 x c chain staggering. The minimum models were subjected to a search for preferred orientations of O2 and O6 hydroxyl groups. It was found that the hydroxyl groups present inside the minicrystal tended to rotate into particular orientations during the structure optimizations to form the O5-H-O2 and O3-H-O6 intermolecular hydrogen bonds between the adjacent oligomers in an alternative direction.

Cell Wall↗

PubMed1994

NGF stimulates differentiation of osteoblastic MC3T3-E1 cells.

The activities of NGF on induction of IL-6, ALP and collagen were studied in cultured osteoblastic cells, MC3T3-E1. Treatment of the cells with NGF induced IL-6 production in a dose dependent manner and enhanced ALP activity and collagen biosynthesis without affecting cell proliferation. Cyclo-oxygenase was activated in NGF-treated cells and prostaglandinE2 was detected as a major metabolite from arachidonic acid. Since prostaglandinE2 is an enhancer of ALP activity and collagen biosynthesis in MC3T3-E1 and was found to induce IL-6 production in this study, it is possible that NGF works on MC3T3-E1 cells through the mediation by endogenous prostaglandinE2.

3T3 Cells↗

PubMed1988