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Biomedical subjects

T Sugano

Publications and source records attributed to T Sugano.

At least 73 records · Page 4Linked to original sources
PubMed1995

Prevention of left ventricular thrombus formation during pneumatic pump assist.

A postcardiotomy patient with a pneumatic pulsatile pump for left ventricular assist showed a smoke-like swirling echo within the left ventricle during pump assist. The image disappeared partially during intra-aortic balloon pumping, which was performed as usual. Subsequently, three pumps (native left ventricle, pneumatic and intra-aortic balloon) were driven synchronously; that is, the ventricular assist pump ejected the blood in the first half of the diastole of the native heart beat, and the intra-aortic balloon was inflated during the second half. With this bisected diastolic driving, the abnormal echo disappeared completely. The patient died 52 days after operation, but no thromboembolic episode was observed during the course, and no fresh thrombus was found within the left ventricle at autopsy. The bisected diastolic driving method served as an aid to prevent stagnation of blood and thrombus formation within the native left ventricle in this patient with a left ventricular assist device.

Adult↗
PubMed1995

A novel gene, Translin, encodes a recombination hotspot binding protein associated with chromosomal translocations.

We have identified a novel gene, Translin, encoding a protein which specifically binds to consensus sequences at breakpoint junctions of chromosomal translocations in many cases of lymphoid malignancies. The encoded protein, Translin, is a previously undescribed type with no significant similarity to known proteins. In the native form, Translin polypeptides form a multimeric structure which is responsible for its DNA binding activity. Nuclear localization of Translin is limited to lymphoid cell lines, raising the intriguing possibility that nuclear transport of Translin is regulated in a physiologically significant way such that active nuclear transport is associated with the lymphoid specific process known as Ig/TCR gene rearrangement.

Amino Acid Sequence↗
PubMed1995

Partially deacetylated chitin and hyaluronan induce glycogenolysis in perfused rat liver.

Mannan interacts with mannose/N-acetylglucosamine (GlcNAc) receptors on the surface of both Kupffer cells and endothelial cells in the liver, and induces glycogenolysis through production of peptide-leukotriene (LT) in the perfused rat liver. In the present study, we examined whether positively and negatively charged GlcNAc-containing polysaccharides stimulate glycogenolysis in perfused rat liver. Infusion of the former, 67% deacetylated chitin (DAC), induced biphasic increases in glucose production and a steep decrease in oxygen consumption by the liver. ONO-1078, an LT D4 receptor antagonist, abolished the suppression of oxygen consumption and reduced the glucose production by DAC. Infusion of the latter, hyaluronan, stimulated glucose production with a concomitant increase in oxygen consumption. Ibuprofen, a cyclooxygenase inhibitor, reduced the glucose production by hyaluronan. Sequential infusions of mannan and DAC, but not hyaluronan, did not induce glycogenolytic responses when mannan was infused 20 min before the second stimulation. These results suggest that DAC, but not hyaluronan, stimulates mannose/GlcNAc receptors in the perfused rat liver, and that potent immunological activity induced by DAC may be mediated by activation of the receptors.

Acylation↗
PubMed1995

Immunohistochemical study of c-erb B-2 protein expression in endometriosis.

Using immunohistochemical techniques, we studied the expression of c-erb B-2 in normal human endometrial tissue (n = 8), endometriosis interna (adenomyosis) (n = 8) and endometriosis externa (endometriotic cyst of the ovary) (n = 6). The glandular epithelium of normal endometrial tissue specimens in the proliferative phase stained positively. Most of the cases of endometriosis studied showed no expression of c-erb B-2 in glandular epithelium. No expression was detected in either the normal or endometriotic stromal cells. Results suggest that c-erb B-2 is not significantly involved in the pathogenesis of endometriosis.

Adult↗
PubMed1995

Effects of an increase in perfusion pressure and of the direction of flow on carbohydrate metabolism in the perfused rat liver.

The effects of increases in perfusion pressure and direction of perfusion flow (anterograde and retrograde) on hepatic carbohydrate metabolism were examined in the isolated perfused rat liver. Changing the direction of flow from anterograde (portal to caval vein) to retrograde (caval to portal vein) increased the rates of glycogenolysis and gluconeogenesis from sorbitol, lactate, pyruvate, and dihydroxyacetone. The extent of stimulation of gluconeogenesis by norepinephrine was higher during anterograde perfusion while stimulation by glucagon was higher during retrograde perfusion. Since the inflowing perfusion pressure was higher in retrograde perfusion (3.8 mmHg) than during anterograde perfusion (2.2 mmHg), we examined the effect of elevation in perfusion pressure on hepatic metabolism. In anterograde (portal to caval vein) perfusion, increases in perfusion pressure above the basal level (2.2 mmHg) caused increases in rates of glycogenolysis and gluconeogenesis with maximum rates at 4 mmHg. The extent of stimulation of gluconeogenesis by norepinephrine decreased and that by glucagon increased during perfusion at elevated pressure. At the same perfusion pressure (4 mmHg), there were no differences in rates of glycogenolysis and gluconeogenesis and in the responses to hormones between anterogradely and retrogradely perfused livers. The omission of Ca2+ ions from the perfusate abolished the effects of retrograde perfusion and of the elevation of perfusion pressure on carbohydrate metabolism. An infusion of A23187 (30 nM) induced an increase in both glycogenolysis and gluconeogenesis with unchanged perfusion pressure. The results suggest that elevated perfusion pressure during retrograde perfusion stimulates hepatic carbohydrate metabolism via a Ca(2+)-dependent process.

Animals↗
PubMed1995

Separation of protein factors that correct the defects in the seven complementation groups of xeroderma pigmentosum cells.

We fractionated HeLa cell extracts by gel filtration and then micro-injected them into cells derived from the seven complementation groups (A-G) of xeroderma pigmentosum (XP). Distinct fractions that corrected the unscheduled DNA synthesis (UDS) of the complementation group XP cells were identified. The apparent molecular weights corresponding to complementation groups A, B, C, D, E, F, and G were estimated to be 80, 600, 600, 240, 100, 240, and 280 kDa, respectively. These factors were stable in the respective cell lines, the shortest half life being 16 h for the XP-A and XP-G complementing factors. The fraction (80 kDa) that corrected the UDS in XP-A cells also complemented the defect of the XP-A cell extract in the incision of DNA containing a pyrimidine dimer in a cell-free system. The separated fractions will be useful for understanding the molecular nature of these factors and for assigning complementation groups of cells derived from suspected XP patients.

DNA Repair↗
PubMed1995

Nuclear accumulation of p53 in normal human fibroblasts is induced by various cellular stresses which evoke the heat shock response, independently of the cell cycle.

Nuclear accumulation of p53 is induced by various DNA damaging agents (the p53 response). Induction of nuclear accumulation of p53 after various cellular stresses, mostly other than DNA damage, including heat shock, was examined in normal human fibroblasts by immunostaining and flow cytometry using a mouse anti-p53 monoclonal antibody. Immunostaining revealed nuclear accumulation of p53 within 6 h after various stresses [heat shock, osmotic shock, heavy metal (Cd), blockers of the cellular respiratory system (NaN3), amino acid analogues (azetidine and canavanine), an inhibitor of protein synthesis (puromycin), and oxygen free radicals (H2O2)]. Heat shock proved to be one of the most effective inducers among these stresses. FACScan analysis revealed that this induction of p53 occurred regardless of the stage in the cell cycle and that accumulation of cells in G2/M occurred. As all of these stresses are known to induce the heat shock response, the mechanism of p53 induction after stresses and that of heat shock response may share, at least partly, some common signaling pathway(s).

Cell Cycle↗
PubMed1995

Cold acclimation induces zonal heterogeneity in gluconeogenic responses to glucagon in rat liver lobule.

The relationship between the enhanced responses of gluconeogenesis to norepinephrine (NE) and glucagon and its zonal distribution was studied in liver lobules of cold-exposed rats by examination of preparations enriched for periportal hepatocytes (PP-H) and for perivenous hepatocytes (PV-H) by the digitonin-collagenase perfusion technique. In the control group, gluconeogenesis from lactate (10 mM) plus pyruvate (1 mM) was higher in PP-H than in PV-H. NE (100 nM) and glucagon (100 nM) increased the rate of gluconeogenesis by 80 and 70%, respectively, in both PP-H and PV-H. Gluconeogenesis in PP-H was unchanged by cold exposure. The rate in PV-H increased to the rate in PP-H at 5 days after cold exposure, and then the rate returned to the control value at 20 days. The gluconeogenic response to the alpha-adrenergic action of NE in both PP-H and PV-H doubled after 5 days. The response to glucagon tripled in PP-H and was cut in half in PV-H after 20 days. Phorbol 12-myristate 13-acetate (PMA; 1 microM), A-23187 (100 nM), and dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP; 1 mM) increased the rate of gluconeogenesis by 200, 100, and 80%, respectively, in both PP-H and PV-H from the control group. The responses to PMA and A-23187 were unchanged by exposure to cold. The response to DBcAMP was doubled in PP-H and was cut in half in PV-H after 20 days of cold exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Acclimatization↗
PubMed1995

[Two cases underwent patch closure and mitral annuloplasty for ventricular septal perforation and mitral regurgitation caused by acute inferior myocardial infarction].

Two cases underwent successful operation for the ventricular septal perforation (VSP) and mitral regurgitation (MR) caused by acute myocardial infarction (AMI) are reported. Patch closure of VSP and mitral annuloplasty (MAP) by Kay-Suzuki method were performed. Location of VSP were posterior ventricular septum and moderate MR were detected in both cases. Case 1 was a 74-year-old man. Four weeks after AMI, patch closure of VSP through right ventricular approach and MAP through trans-atrial approach and also aorto-coronary bypass to left anterior descending artery were performed. Doppler echocardiography was effective to evaluate the severity of VSP and MR. Case 2 was a 69-year-old man. Eight days after AMI, patch closure of VSP and MAP were performed through biventricular approach. Postoperative examination revealed the disappearance of left-to-right shunt and MR in both cases. These cases operated successfully were thought to be rare.

Aged↗
PubMed1995

[Clinical features of epithelial ovarian cancer in young reproductive women].

A 10-year retrospective review of epithelial carcinoma of the ovary was performed about 95 patients which were diagnosed and treated at the Oita Medical University Hospital. The patients' ages at the first diagnosis ranged from 15 to 85 years with a mean of 51.6 years. Twenty-two of 95 patients (23.2%) were below the age of 40. Most patients analysed in this study complained of lower abdominal pain, lower abdominal mass, and/or lower abdominal fullness. Sixteen of 22 patients under the age of 40 (72.7%) and 27 of 73 patients over the age of 40 (37.0%) were diagnosed as having mucinous cystadenocarcinoma. The incidence of mucinous cystadenocarcinoma below the age of 40 was significantly higher than that over the age of 40 (p < 0.005, chi 2-test). Eleven patients below the age of 40 had FIGO stage Ia grade 1 disease and 2 of these patients were pregnant. The incidence of stage Ia disease under the age of 40 was significantly higher than that over the age of 40 (p < 0.005, chi 2-test). Both pregnant patients and 5 other patients with stage Ia disease were treated with only unilateral salpingo-oophorectomy. All patient with stage Ia disease had no evidence of recurrence within 5 years. This suggests that conservative surgery may be considered as the treatment for the FIGO stage Ia grade 1 ovarian cancer.

Adolescent↗