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Biomedical subjects

M Ueno

Publications and source records attributed to M Ueno.

At least 145 records · Page 8Linked to original sources
PubMed2000

Coloanal anastomosis in surgery for rectal cancer.

The definition of coloanal anastomosis should be based on anatomy of the anal canal. The anal canal is terminal portion of the digestive tract and comprises muscle tube of approximately 3 cm long with a lumen coated with several types of mucosa or epithelium. Muscle tube of the anal canal consists of two layers, inner sphincter muscle and external sphincter muscle. The former is a continuation of rectal muscle layer and the latter extends to the levator ani muscle. Colo-anal anastomosis (CACA): whole of the rectum is excised with a separation line placed just above the anal canal. An anastomosis is made between colonic cut end and upper limit of the anal canal. Colo-anus anastomosis in a narrow sense (CAA): rectum is excised with a bit of upper part of the anal canal. Then an anastomosis is made inside the anal canal.

Anal Canal↗
PubMed1999

Thioredoxin-dependent redox regulation of p53-mediated p21 activation.

Thioredoxin (TRX) is a dithiol-reducing enzyme that is induced by various oxidative stresses. TRX regulates the activity of DNA-binding proteins, including Jun/Fos and nuclear factor-kappaB. TRX also interacts with an intranuclear reducing molecule redox factor 1 (Ref-1), which enhances the activity of Jun/Fos. Here, we have investigated the role of TRX in the regulation of p53 activity. Electrophoretic mobility shift assay showed that TRX augmented the DNA binding activity of p53 and also further potentiated Ref-1-enhanced p53 activity. Luciferase assay revealed that transfection of TRX enhanced p53-dependent expression of p21 and further intensified Ref-1-mediated p53 activation. Furthermore, Western blot analysis revealed that p53-dependent induction of p21 protein was also facilitated by transfection with TRX. Overexpression of transdominant negative mutant TRX (mTRX) suppressed the effects of TRX or Ref-1, showing a functional interaction between TRX and Ref-1. cis-Diamminedichloroplatinum (II) (CDDP) induced p53 activation and p21 transactivation. The p53-dependent p21 transactivation induced by CDDP was inhibited by mTRX overexpression, suggesting that TRX-dependent redox regulation is physiologically involved in p53 regulation. CDDP also stimulated translocation of TRX from the cytosol into the nucleus. Hence, TRX-dependent redox regulation of p53 activity indicates coupling of the oxidative stress response and p53-dependent repair mechanism.

Carbon-Oxygen Lyases↗
PubMed1999

A novel mammalian T-box-containing gene, Tbr2, expressed in mouse developing brain.

We have identified and characterized a new member of the mammalian brain-specific T-box gene family, Tbr2, which is closely related to mouse Tbr1, and to the Xenopus earliest mesodermal gene, Eomesodermin. As Tbr1, Tbr2 is predominantly expressed in some regions of the developing brain, but in a strikingly complementary manner. On embryonic day 14.5 (E14.5), Tbr2 mRNA expression was observed in the mesencephalon and rhombencephalon in contrast to Tbr1 which was expressed mostly in the telencephalon. At this stage, Tbr2 mRNA was readily detectable in the postmitotic and differentiating neurons located in various brain regions, i.e., oculomotor, red, trigeminal, vestibular, facial, and hypoglossal nuclei. However, expression of Tbr2 in these nuclei became undetectable on E18.5. In contrast, Tbr2 mRNA expression was detected in the hippocampus only from E18.5 onwards. Whereas Tbr2 expression disappeared in most parts of the mature adult brain, it remained detectable in the hippocampus and olfactory bulb, regions where some neuronal precursors retain their differentiation potential. These results suggest that Tbr2 may play a crucial role in differentiating neurons rather than in proliferating or already differentiated neurons. In addition, similarly to Xenopus Eomesodermin, mouse Tbr2 showed biphasic expression; a first peak around E6.5 and a second peak around E14.5, suggesting that Tbr2 may also be important at early stages of gastrulation.

Amino Acid Sequence↗
PubMed1999

Stability of the dimerization domain effects the cooperative DNA binding of short peptides.

The basic region peptide derived from the basic leucine zipper protein GCN4 bound specifically to the native GCN4 binding sequences in a dimeric form when the beta-cyclodextrin/adamantane dimerization domain was introduced at the C-terminus of the GCN4 basic region peptide. We describe here how the structure and stability of the dimerization domain affect the cooperative formation of the peptide dimer-DNA complex. The basic region peptides with five different guest molecules were synthesized, and their equilibrium dissociation constants with a peptide possessing beta-cyclodextrin were determined. These values, ranging from 1.3 to 15 microM, were used to estimate the stability of the complexes between the dimers with various guest/cyclodextrin dimerization domains and GCN4 target sequences. An efficient cooperative formation of the dimer complexes at the GCN4 binding sequence was observed when the adamantyl group was replaced with the norbornyl or noradamantyl group, but not with the cyclohexyl group that formed a beta-cyclodextrin complex with a stability that was 1 order of magnitude lower than that of the adamantyl group. Thus, cooperative formation of the stable dimer-DNA complex appeared to be effected by the stability of the dimerization domain. For the peptides that cooperatively formed dimer-DNA complexes, there was no linear correlation between the stability of the inclusion complex and that of the dimer-DNA complex. With the beta-cyclodextrin/adamantane dimerization domain, the basic region peptide dimer preferred to bind to a palindromic 5'-ATGACGTCAT-3' sequence over the sequence lacking the central G.C base pair and that with an additional G.C base pair in the middle. Changing the adamantyl group into a norbornyl group did not alter the preferential binding of the peptide dimers to the palindromic sequence, but slightly affected the selectivity of the dimer for other nonpalindromic sequences. The helical contents of the peptides in the DNA-bound dimer with the adamantyl group were decreased by reducing the stability of the dimer-DNA complex, which was possibly caused by deformation of the helical structure proximal to the dimerization domain.

Basic-Leucine Zipper Transcription Factors↗
PubMed1999

Pertussis toxin-sensitive G proteins as mediators of stretch-induced decrease in nitric-oxide release of osteoblast-like cells.

Mechanical loading plays an important role in regulating bone remodeling, and nitric oxide may be one regulator of this process. To determine how mechanical stress modulates osteoblast function, we loaded cyclic tensile stretch on osteoblast-like cells and measured levels of nitric oxide in the medium. High frequency of stretch at any magnitude inhibited release of nitric oxide; however, low frequency of stretch enhanced its release from the static control. To examine the involvement of G protein (guanine nucleotide-binding regulatory protein) in stress-inhibited release of nitric oxide, we added pertussis toxin, a specific inhibitor of the Gi class, and found that it completely reversed the stress-inhibited release. These data support the idea that pertussis toxin-sensitive G protein is activated in the presence of cyclic tensile stretch.

Bone Remodeling↗
PubMed1999

Hepatic lymph node involvement in resected cases of liver metastases from colorectal cancer.

PURPOSE: Lymph node metastasis in the hepatoduodenal ligament is known as one of the most significant prognostic factors after liver resection for colorectal metastasis. However, there have been very few articles on the clinical features of node-positive patients and on detailed distribution of positive nodes. Further, there has been no established strategy on how to handle hepatic lymph nodes during liver resection. To address these subjects, a retrospective study was conducted. METHODS: During the period of 1980 through April 1998, 182 hepatic resections were performed for metastatic colorectal carcinoma. Of these, 78 cases had hepatic lymph node sampling during the operation. Distribution of positive nodes, location of liver metastasis, stage of the primary lesion, and outcome after liver resection were analyzed. RESULTS: Nine cases (12 percent) had secondary lymph node metastases in the hepatoduodenal ligament. The incidence was slightly higher (13.5 percent) in the most recent 44 consecutive cases. There was a tendency for liver metastases in the right lobe to metastasize to No. 12b (or node of the foramen of Winslow, lymph nodes along the common bile duct) and liver metastases in the left lobe to metastasize to No. 8a (anterosuperior group of the lymph nodes along the common hepatic artery). Outcome of node-positive patients (n = 9) was extremely poor (P < 0.001) compared with that of node-negative patients (n = 66), and the most common site of recurrence in the node-positive patients was remnant liver and hepatic lymph nodes. Preoperatively, there were no significant predicting factors for positive hepatic lymph nodes. CONCLUSIONS: No. 8a and No. 12b nodes are principal nodes that should be palpated and sampled during liver resection to check the secondary lymphatic spread from liver metastases. Hepatic nodal involvement indicates the progression of disease beyond simple liver metastases and may not be the indication for simple surgical removal. Further study, including hepatoduodenal dissection and systemic adjuvant chemotherapy, may elucidate the survival benefit, if any, of liver resection in node-positive patients.

Case-Control Studies↗
PubMed1999

Extrahepatic biliary atresia associated with trisomy 18.

A case of extrahepatic biliary atresia (EBA) associated with trisomy 18 is presented. A 1-month-old boy was suspected to have Alagille syndrome with obstructive jaundice, a systolic heart murmur, growth retardation, and a small, pointed chin. However, surgery and chromosomal analysis revealed EBA associated with trisomy 18. Chromosomal examination must be performed in patients with jaundice and congenital anomalies. It is possible that EBA in trisomy 18 syndrome is due to a chromosomal disorder.

Bile Ducts, Extrahepatic↗
PubMed1999

The passage of blood-borne horseradish peroxidase into the amygdaloid area of the mouse brain.

The passage of blood-borne horseradish peroxidase (HRP) into the amygdaloid area of the mouse brain was examined with light and electron microscopy. Staining reaction for HRP appeared in medial portions of the amygdaloid area, especially adjacent to the optic tract. Ultrastructural examination of some vessels in that area revealed that the staining reaction for HRP appeared in the perivascular space, the basal lamina, the cytoplasm or vesicular structures of the perivascular cells, vesicular profiles of the endothelial cell cytoplasm including abluminal pits and the adjacent extracellular space. These findings suggest that intravascular macromolecules can invade medial portions of the amygdaloid area of the mouse brain.

Amygdala↗
PubMed1999

Suppression of default apoptosis in androgen-dependent cells by testosterone-mediated bcl-2 expression.

BACKGROUND: The significance of apoptosis with regard to the development and progression of androgen-dependent cells has not been clearly understood. In the present study we investigated the expression of the bcl-2 proto-oncogene after androgen deprivation and its role in cell growth in an androgen-dependent cell line. METHODS: We used SC2G, an androgen-dependent mouse mammary carcinoma cell line cloned from Shionogi carcinoma 115 (SC115). The expression of bcl-2 mRNA and protein in SC2G cells was measured by reverse transcription-polymerase chain reaction and western blotting, respectively. We also investigated the effects of antisense oligodeoxynucleotides (ODN) complementary to strategic sites in the mouse bcl-2 gene in SC2G cells. RESULTS: When SC2G cells were cultured in serum-free medium, the number of viable cells was significantly larger among cells with testosterone than those without testosterone after 3 days. Apoptosis was demonstrated in approximately 30% of positive-staining nuclei in SC2G cells cultured in testosterone-free medium. The levels of bcl-2 mRNA and protein in SC2G cells started to decrease after testosterone withdrawal. The cell density of SC2G cells decreased after 4 days culture with antisense ODN when compared with cells cultured in the presence of sense control. CONCLUSIONS: These data indicate that bcl-2 proto-oncogene inhibits the self-programmed apoptosis of androgen-dependent cells, suggesting the possibility of an antisense therapy for hormone-refractory prostate cancer, which is reported to express high levels of Bcl-2 protein.

Animals↗
PubMed1999

Esophageal cancer and right aortic arch associated with a vascular ring.

We report on the problems of diagnosis and surgical technique from the standpoint of mediastinal anatomy in patients with esophageal cancer and right aortic arch associated with a vascular ring. We propose that left thoracotomy plus sternotomy is the best approach to allow visualization of the bilateral recurrent laryngeal nerves.

Aorta, Thoracic↗
PubMed1999

A brain region-specific gene product Lhx6.1 interacts with Ldb1 through tandem LIM-domains.

LIM-homeodomain (LHX) transcription factors play critical roles in cell fate determination during development, in particular, in CNS. The transcriptional activity of several LHX proteins is postulated to be regulated by interaction with an LIM-domain binding protein, Ldb1. We have now identified a novel LHX molecule, termed Lhx6.1, that is closely related to a recently reported Lhx6 molecule. The Lhx6.1 transcript is found in several restricted regions in the developing CNS, mostly within the embryonic forebrain. We further show that Lhx6.1 interacts with Ldb1 through tandem LIM-domains, implying transcriptional regulation of Lhx6.1 by Ldb1.

Amino Acid Sequence↗
PubMed1999

Effects of physiological or pathological pressure load in vivo on myocardial expression of ET-1 and receptors.

Endothelin (ET)-1 has potent positive inotropic and chronotropic activity in the heart and induces cardiac hypertrophy. The production of ET-1 in the heart is reported to be increased under some conditions. In normal circulation, the pressure load to the left ventricle (LV) is much greater than that to the right ventricle (RV). In this study, we investigated the gene expression of the myocardial ET-1 system (ET-1, ET(A) receptor, and ET(B) receptor) in the RV and LV of normal rats and also investigated these genes in hypertrophied RV due to pathological pulmonary hypertension (PH). Normal rats showed no differences between the RV and LV in the gene expression of either ET-1, ET(A) receptor, or ET(B) receptor in either the adult stage (11 wk old) or the neonatal stage (1 and 8 days old). On the other hand, the expression of both atrial natriuretic peptide (ANP) mRNA and B-type natriuretic peptide (BNP) mRNA was significantly greater in the LV than in the RV in adult rats. Gene expression of ET-1, ET(A) receptor, and ET(B) receptor in the RV was markedly higher in rats with monocrotaline-induced (pathological) PH than that in control rats. The expression of ANP mRNA and BNP mRNA in the RV was also markedly higher in the rats with PH. In conclusion, the data suggest that gene expression of the ET-1 system in the myocardium is not affected by physiological pressure load in either the adult stage or neonatal stage; however, it is enhanced by pathological pressure overload such as that in PH.

Animals↗
PubMed1999

Induction of transient proteinuria, hematuria, and glucosuria by ethanol consumption in Japanese alcoholics.

Urinalysis was carried out in 231 inpatients with alcohol dependence syndrome (215 males and 16 females). Fifty-nine patients (25.5%) showed proteinuria, 97 (42.0%) showed glucosuria, and 62 patients (26.8%) showed hematuria on admission. A total of 135 out of 231 patients (58.4%) showed abnormal urinalysis. Proteinuria was related to high blood pressure, high serum glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, lactate dehydrogenase, uric acid, and triglyceride levels, and high urinary amylase concentration. Glucosuria was related to high serum glutamic-oxaloacetic transaminase concentration and a history of gastrectomy. Hematuria was related to high age and high urinary amylase levels. By chi-square test, there was a significant correlation between proteinuria and hematuria (p < 0.001) and between hematuria and glucosuria (p < 0.001), but no correlation was found between proteinuria and glucosuria. The incidence of diabetes mellitus was 10.8% (25 out of 231 patients), but transient hyperglycemia was observed in some patients without diabetes mellitus on admission. Elevated hemoglobin A1, hemoglobin A1c, and fructosamine concentrations were observed in patients with either impaired glucose tolerance or transient hyperglycemia, which suggested the presence of persistent hyperglycemia before admission. On discharge, only 12 out of 198 patients (6.1%) showed abnormal urinalysis. We report that heavy ethanol consumption induces transient abnormal urinalysis results in Japanese alcoholics.

Adult↗
PubMed1999

Crucial role of group IIA phospholipase A(2) in oleic acid-induced acute lung injury in rabbits.

Group IIA secretory phospholipase A(2) (sPLA(2)) has been implicated in a variety of inflammatory diseases including acute lung injury (ALI); however, the role of sPLA(2) in this disorder remains unclear. The aim of the present investigation was to examine the role of this enzyme in a model of ALI induced by oleic acid (OA) in rabbits by testing human group IIA phospholipase A(2) (PLA(2)) inhibitor, S-5920/LY315920Na. Experimental groups consisted of a saline control group (n = 8), an OA control group (n = 10) infused intravenously with OA (0.1 ml/kg/h for 2 h), and three groups given OA + S-5920/LY315920Na (three different doses, n = 8, respectively). Infusion of OA provoked pulmonary hemorrhage and edema formation, protein leakage, and massive neutrophil infiltration, resulting in severe hypoxemia and impaired lung compliance. PLA(2) activity was detected in the bronchoalveolar lavage fluid (BALF), but not plasma, which correlated well with severity of lung injury in this model. Pretreatment with S-5920/LY315920Na diminished the OA-induced PLA(2) activity in the BALF and dose-dependently attenuated the previously described lung injury induced by OA, accompanied by protection against lung surfactant degradation and production of thromboxane A(2) (TXA(2)) and leukotriene B(4) (LTB(4)). S-5920/LY315920Na also inhibited the OA-induced production of interleukin-8 (IL-8), both in plasma and BALF. Thus, sPLA(2) appears to play a key role in OA-induced lung injury, suggesting that the group IIA PLA(2) inhibitor may be a promising agent for patients with acute respiratory distress syndrome (ARDS).

Acetates↗
PubMed1999

Effects of incorporation of various amphiphiles into recipient liposome membranes on inter-membrane protein transfer.

To obtain information about the factors governing spontaneous inter-membrane protein transfer, we examined the effects of incorporation of various amphiphilic compounds in dimyristoylphosphatidylcholine (DMPC) liposomes on protein transfer from influenza virus-infected cells to the liposomes, and analyzed the physical properties of these liposome membranes. The incorporation of amphiphilic compounds, negatively charged dicetylphosphate (DCP), dipalmitoylphosphatidylserine (DPPS) or positively charged dimethyldipalmitoylammonium (DMDPA), into DMPC liposomal membranes enhanced protein transfer. The liposomes containing DCP, DPPS or DMDPA were unaffected by osmotic shock caused by external addition of glucose, suggesting a decrease in lipid packing in the liposomal membranes. Furthermore, calorimetric study of these liposomes showed that a phase separation occurred partially in the liposomal membranes. Accordingly, the membranes of DMPC liposomes containing DCP, DPPS and DMDPA should be distorted due to the coexistence of two phases, gel and liquid crystalline, in the membranes. Consequently, the membrane distortion could be responsible for the enhancement effects of the amphiphiles on the inter-membrane protein transfer from influenza virus-infected cells to the liposomes.

Cells, Cultured↗
PubMed1999

Rationale for time-qualified reference standards for 24-hour blood pressure values and their circadian rhythms in Japanese normotensive adults: a study by the Ambulatory Blood Pressure Monitoring Research Group.

The aim of this study was to demonstrate that blood pressure (BP) has to be standardized according to its circadian variability, including the properties shown in its circadian rhythm. The BP time-qualified standards were derived from a sample of 644 clinically healthy normotensive Japanese subjects (320 males, 324 females; age range, 18-93 years), stratified by age-group and gender, who underwent noninvasive ambulatory monitoring according to a fixed protocol. The monitored data series shows that BP exhibits a within-day variability at any age of life in both males and females. Additionally, the monitored data series shows that BP exhibits a significant circadian rhythm at any age of life in both males and females. The age- and sex-related reference limits for the BP within-day variability constitute the time-qualified standards against which both the casual and monitored BP measurements can be compared in order to detect whether or not they are compatible with normotension. The reference limits for the BP circadian rhythm represent the rhythmometric standards against which the BP oscillatory curve can be compared in order to detect whether or not they are compatible with a physiological circadian rhythm.

Adolescent↗
PubMed1999

[Successful treatment of acute renal failure in a patient with essential mixed cryoglobulinemia using prednisolone and cryofiltration].

We report a case of acute renal failure associated with cryoglobulinemic glomerulonephritis. The patient, a 49-year-old woman, was referred to our hospital because of acute nephritic syndrome. After admission, she developed oliguria, and hemodialysis was instituted. Renal biopsy was performed and the specimens showed moderate endocapillary proliferation, large deposits filling the capillary lumen ("intraluminal thrombi"), and a double-contoured appearance, which are typical morphologic features of cryoglobulinemic glomerulonephritis. Immunoelectrophoresis showed a monoclonal increase of IgM kappa. On the basis of these findings, we diagnosed type II essential mixed cryoglobulinemia. Cryofiltration was performed with oral administration of prednisolone. Following the start of therapy, the patient's renal function gradually improved. Because of severe hypoproteinemia, cryofiltration was discontinued after three sessions. However, renal function recovered and was maintained with prednisolone only. This case shows that acute oliguric renal failure caused by cryoglobulinemic glomerulonephritis can be reversible if immunosuppressive therapy, together with plasmapheresis in more severe cases, is instituted promptly.

Acute Kidney Injury↗