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Biomedical subjects

H Omori

Publications and source records attributed to H Omori.

At least 19 recordsLinked to original sources
PubMed2001

Correlation between TGF-beta1 and p21 (WAF1/CIP1) expression and prognosis in resectable invasive ductal carcinoma of the pancreas.

Transforming growth factor-beta1 (TGF-beta1) inhibits the growth of a variety of epithelial cells; however, in many types of tumors it loses its inhibitory effect. p21(WAF1/CIP1), one of the cyclin-dependent kinase (Cdk) inhibitors induced by TGF-beta1, is considered a downstream effector of the growth-inhibitory function of TGF-beta1. We assessed the clinicopathologic significance of TGF-beta1 and p21 expression in resectable invasive ductal carcinoma (IDC) of the pancreas. Immunohistochemical examination of the expression of TGF-beta1 and p21 in 62 patients revealed positive expression of TGF-beta1 in 28 (45%) and of p21 in 25 (40%) of the 62 patients, and a significant correlation between the two expressions. The survival curve of patients with TGF-beta1(+) tumors was significantly higher than that of patients with TGF-beta1(-) tumors; p21(+) patients showed a higher survival curve than did p21(-) patients, but the difference was not statistically significant. Simultaneous analysis of TGF-beta1 and p21 expression showed that the patients with TGF-beta1(+)/p21(+) tumors had a significantly better prognosis than the others. Multivariate analysis showed that TGF-beta1 was a significantly low risk factor for death due to IDC. The concurrent evaluation of TGF-beta1 and p21 expression would be an effective tool in the prediction of the prognosis of patients with pancreatic cancer.

Adult↗
PubMed2000

Bone grafting in cementless total hip replacement for congenital dysplasia of the hip.

We reviewed 27 cementless primary total hip replacements in patients with osteoarthrosis secondary to congenital dysplasia of the hip. Autogenous bone grafting was used as augmentation. On average the follow-up period was 9 years. Two hips were revised and three acetabular components were considered loose. In hips with loose cups the average graft coverage was significantly greater than in stable hips. The use of a cementless acetabular component is encouraging for reconstruction, although extensive grafting should be avoided. Our study suggests that cementless reconstruction in dysplastic hips yields a satisfactory outcome.

Adult↗
PubMed2000

Serial measurement of polyethylene wear of well-fixed cementless metal-backed acetabular component in total hip arthroplasty: an over 10 year follow-up study.

Serial radiographic measurements of polyethylene wear were performed in 38 hips (33 patients) with primary cementless total hip arthroplasty (THA). The average follow-up period was 131.8 months. All prostheses were assessed as radiographically stable at the latest follow-up. A two-dimensional method was used to calculate the relative migration of the femoral head center to the cup center. The average total linear wear and wear rate were 1.22 mm and 0.11 mm/year, respectively. The degree of wear in the first 2 postoperative years accounted for nearly 40% of the total wear at the end of the study (average follow up: 131.8 +/- 10.0 months, +/-SD). The migration of the femoral head at an average period of 3. 4 months after operation accounted for 56% of the amount of wear in the first 2 years. Wear rate decreased gradually with time and stabilized after the fourth year. However, in 2 patients, a progressive increase in the wear rate was associated with severe osteolysis and failure of THA. Both creep and wear contributed to the femoral penetration into the polyethylene liner. The influence of creep cannot be ruled out, especially in the early period after operation. Polyethylene wear is a multifactorial process, and the study of individual wear patterns might be useful in identifying patients who are at risk of late failure of THA.

Acetabulum↗
PubMed1999

Nonlinear three-dimensional finite element analysis of newly designed cementless total hip stems.

We designed 2 new types of proximally coated stems (the FMS and FMS-anatomic) based on the endosteal geometry of femora with congenital dislocation or dysplastic hip. The FMS was symmetric while the FMS-anatomic was asymmetric. We compared the proximal fit and fill to the femoral canal, contact stress, relative motion, and load transfer to the femur of 5 stems (FMS, FMS-anatomic, Omnifit, Omniflex, and individual stem) using three-dimensional computer simulation and finite element analysis. The FMS and FMS-anatomic showed a significantly greater fit and fill than conventional stems. The dispersion of the contact stresses and reduction of relative motions in the proximal area were the best in the FMS-anatomic compared to other stems with the exception of the individual stem. In addition, the FMS-anatomic stem transferred most of the load to the proximal femur. Our results suggest that the FMS-anatomic should provide better biomechanical stability at least in the early postoperative period.

Arthroplasty, Replacement, Hip↗
PubMed1999

Modified Fontan operation. Considerations for the determination of the appropriate procedure.

BACKGROUND: Although the surgical results of the modified Fontan operation continues to improve, there are various advantages and disadvantages in terms of the post operative condition associated with the Fontan modifications. Late morbidity and mortality are mainly due to arrhythmias, thromboembolic complications, systemic venous hypertension and infective endocarditis. We reported our experience of the modified Fontan operation to determine an appropriate procedure for each patient. METHODS AND RESULTS: Seven patients (ranging from the age 1-14 years) underwent a modified Fontan operation including a lateral tunnel (n = 1), extracardiac conduit (n = 2) and autogenous atrial tunnel (n = 4). There was one hospital death due to sepsis in which the patient underwent lateral tunnel procedure. The mean follow up of another six patients was 20 months (ranging from 1-39 months) and all patients were classified as NYHA class I, and remained in normal sinus rhythm without any thromboembolic complications. CONCLUSIONS: When using the autogenous atrial tunnel, there are potential advantages; it is not associated with thromboembolism or endocarditis and has growth potential. However, in high-risk patients with increased pulmonary vascular resistance, impaired ventricular function and pre-operative atrial arrhythmias, it appears reasonable to use an extracardiac conduit.

Adolescent↗
PubMed1998

Dumb-bell shaped tuberculous abscess across the greater sciatic notch compressing both sciatic nerves.

We report an instructive case of a 65-year-old man who presented with a dumb-bell shaped tuberculous abscess across the greater sciatic notch bilaterally compressing both sciatic nerves. Clinical symptoms progressed slowly and mimicked lumbar radiculopathy, thus delaying an accurate diagnosis. Anterolateral retroperitoneal and posterolateral gluteal approaches of the greater sciatic notch as well as the acetabulum on both sides were followed in order to provide safe viewing and resection of the abscess. The abscess wall was adherent to the sciatic nerve and surrounding blood vessels. The symptoms completely disappeared after resection of the abscess.

Abscess↗
PubMed1998

Mechanisms of cytotoxic effects of heavy water (deuterium oxide: D2O) on cancer cells.

Heavy water (deuterium oxide: D2O) contains a neutron and a proton in its hydrogen atoms and shows a variety of biologic activities different from normal light water. In the present study the cytotoxic and cytostatic activity of D2O was assessed using a BALB/c-3T3 fibroblast cell line and four human digestive organ cancer cell lines, i.e. HepG2 hepatic, Panc-1 pancreatic, KATO-3 gastric and Colo205 colonic cancer cell lines. Against four cancer cell lines, D2O showed significant cytotoxic and cytostatic effects in a MTT assay and a Trypan blue dye exclusion assay, at concentrations higher than 30% D2O. These effects were time and dose dependent, and the IC50 after 72 h of culture ranged from 20 to 30% D2O in the Trypan blue dye exclusion assay and from 30 to 50% D2O in the MTT assay. By contrast, IC50 for the 3T3 fibroblast cell line after 72 h of culture was about 15% in the Trypan blue dye exclusion assay and 50% inhibition was not achieved in the MTT assay. Furthermore, D2O was found to significantly inhibit the invasion of tumor cells in a Matrigel invasion chamber assay at concentrations higher than 10% D2O. Incubation with D2O resulted in enlargement of cells, nuclear pyknosis and vacuolization, and immunostaining studies demonstrated that D2O treatment resulted in an increase in nuclear nick-end-labeling, which indicates DNA fragmentation, in KATO-3 and HepG2 cell lines. Furthermore, the nucleic acids and protein synthesis inhibition assay suggested that the inhibition of DNA synthesis may be one of the mechanisms responsible for the antitumor effects of D2O. Furthermore, oral administration of D2O resulted in a significant inhibition of the growth of Panc-1 tumor xenografted s.c. in nude mice, but survival was not prolonged. In conclusion, D2O has cytotoxic and cytostatic activities against human digestive organ cancer cell lines, and D2O may be a potential anticancer agent.

3T3 Cells↗
PubMed1998

Association of fatty liver with increased ratio of visceral to subcutaneous adipose tissue in obese men.

We studied the association of fatty liver with subcutaneous and visceral obesity in 46 male and 36 female patients with body mass index (BMI) over 22 kg/m2. The correlation coefficient between the ratio of the visceral adipose tissue to the subcutaneous adipose tissue (V/S) and the computed tomography (CT) number of the liver was -0.299 (P < 0.05) and that between the V/S ratio and the ratio of the CT number of the liver to that of the spleen (CT-L/CT-S) was -0.335 (P < 0.05) in the males. Partial correlation analysis after making correction for BMI showed an increased correlation coefficient of -0.485 (P < 0.05) between the V/S ratio and the CT-L/CT-S ratio in the males. The odds ratio in the males for CT-L/CT-S below 1.0 and V/S above 1.0 was 3.25 with a 95% confidence interval of 1.02 to 9.39. No such association between the V/S ratio and the CT-L/CT-S ratio was present in the female patients. Multiple regression analysis with serum level of alanine aminotransferase, a marker of fatty liver, as an independent variable revealed a partial regression coefficient of -17.7 for CT-L/CT-S (P < 0.05) in the males and -21.7 (P < 0.05) in the females, validating the CT-L/CT-S ratio as an index of fatty liver. The results indicate the association of fatty liver as determined by the CT-L/CT-S ratio with visceral obesity in males.

Adipose Tissue↗
PubMed1997

Trial of electrolyzed strong acid aqueous solution lavage in the treatment of peritonitis and intraperitoneal abscess.

Electrolyzed strong acid aqueous solution is acidic water that contains active oxygen and active chlorine and possesses a redox potential. We performed peritoneal and abscess lavages with an electrolyzed strong acid aqueous solution to treat 7 patients with peritonitis and intraperitoneal abscesses, who were seen in our department between December 1994 and April 1995. The underlying disease was duodenal ulcer perforation in 4 of these 7 patients and gastric ulcer perforation, acute enteritis, and intraperitoneal perforation of pyometrium in 1 patient each. Irrigation was performed twice a day. Microbiological studies of the paracentesis fluid were negative in 3 cases, and the irrigation period was 2-4 days. Anaerobic bacteria were isolated in 3 of the 4 positive cases (Bacteroides in 2, Prevotella in 1), and a fungus (Candida) was isolated in the remaining patient. The period of irrigation in these patients ranged from 9 to 12 days, but conversion to a microorganism negative state was observed in 3-7 days.

Abdominal Abscess↗
PubMed1997

Direct detection of Campylobacter jejuni in chicken cecal contents by PCR.

Campylobacter jejuni in chicken feces was detected by PCR and Southern blot hybridization (SBH). The detection limits of C. jejuni in chicken feces were 34,000 cells by PCR and 340 cells by SBH. Some cecal contents of chickens up to 3 weeks old were C. jejuni positive by SBH whereas all of them were negative by PCR. Two of 51 cecal contents of 18-day-old chicken embryos were C. jejuni positive by PCR and SBH; but, C. jejuni were not isolated from the samples by conventional culture with selective enrichment.

Aging↗
PubMed1997

Deuterium oxide (heavy water) accelerates actin assembly in vitro and changes microfilament distribution in cultured cells.

While deuterium oxide (D2O) is known to produce various biological effects in living animals and cultured cells, the detailed mechanisms by which it does so remain unclear. The present study was designed to assess the effects of D2O on microfilaments (MFs) via fluorescence staining of BALB 3T3 cells and in vitro actin polymerization studies. After BALB 3T3 cells had been exposed to a concentration of more than 30% D2O for several hours, stress fibers in the peripheral region became thick and distinct, while the quantity of perinuclear MFs was drastically reduced. This effect was transient and returned to the original distribution within 12 h. Cytoplasmic F-actin (FA) also increased transiently coincident with the enhancement of stress fibers. The pattern of cell locomotion became simpler, and total locomotor activity was suppressed in a D2O concentration-dependent manner. Analysis of in vitro studies demonstrated that, when purified G-actin was polymerized in D2O at a concentration greater than 10%, the rate of actin polymerization was accelerated, whereas the total amount of polymerized actin at the steady state in D2O was the same as that in H2O controls. A gelation assay and transmission electron microscopy (TEM) showed that the network of crosslinked FA with alpha-actinin became denser in 30% D2O than in H2O. These findings concerning actin polymerization and FA gelation suggest that the alteration of stress fibers in cultured cells is caused by a direct effect of D2O on cellular MF dynamics.

3T3 Cells↗
PubMed1996

[Application for therapeutic use of deuterium oxide (D2O) against human pancreatic cancer].

This study was designed to assess the possibility of D2O as a therapeutic agent against human pancreatic cancer. We examined the effect of D2O on growth and invasion of human pancreatic cancer cells (Panc-1, MIA PaCa-2, BxPC-3) by using MTT assay and nude mice, on which human pancreas cancer cells were transplanted. In vitro growth of the three lines was significantly inhibited by D2O in a dose dependent manner, especially at more than a 10% concentration. Growth of Panc-1, which was transplanted in nude mice, was also inhibited by continuous oral intake of 30% D2O. Furthermore, the effect of D2O on cancer invasiveness was assessed by Matrigel invasion chamber assay. BxPC-3, which is the most adherent of the three lines, significantly reduced its invasiveness in more than 30% D2O media. In addition, the present study also demonstrated the inhibition of cancer cell locomotion by D2O in phagocytokinetic analysis. In conclusion, D2O may be applied for the therapeutic use against pancreatic cancer.

Animals↗
PubMed1994

Intravascular hypercoagulability in patients with recent Bell's palsy.

Eighty-four patients were examined for blood coagulability during the acute phase of Bell's palsy. Abnormally high levels of thrombin-antithrombin III complex (TAT) and alpha-2 plasmin inhibitor-plasmin complex (PIC) were found, with these increases statistically significant. Values tended to be higher in patients within 3 days after occurrence of the palsy when compared to values in patients 4 days or more later. Abnormal TAT and PIC levels in the acute phase then tended to become normalized during the convalescent phase of the disease. These findings indicated that activation of intravascular coagulability had occurred, with patients entering a temporary clot-forming state. Among the several hypotheses for the etiology of Bell's palsy, our findings support a circulation disorder as an influential factor.

Acute Disease↗