Biomedical subjects

T Nakayama

Publications and source records attributed to T Nakayama.

At least 37 records · Page 2Linked to original sources

PubMed2005

[Advantages of side-to-side anastomosis in the assessment and revision of coronary artery bypass grafting].

With the advent of drug eluting stents in percutaneous coronary intervention, required quality level of coronary artery bypass grafting (CABG) has been elevating. To obtain nearly perfect patency of bypass grafts, intraoperative assessment and repair of abnormal grafts are helpful. We report systematic revision and safe repair technique of arterial grafts in CABG. Side-to-side instead of commonly used end-to-side anastomosis of arterial grafts is the first step in this technique. When any abnormalities are noted in intraoperative flowmetry of a graft, the distal surgical clip is removed. Free flow of the graft is measured. A coronary probe is gently inserted into the graft and the coronary artery. Vasodilators can be injected into the graft if necessary. When direct revision of the anastomosis is indicated, the graft is cut longitudinally from the distal end up to just proximal to the anastomotic site. The shape of the anastomosis can be observed directly without removing sutures. When re-anastomosis is not indicated, the distal remnant graft tissue is folded back and utilized as a patch. Thus the graft can be easily closed without narrowing.

Anastomosis, Surgical↗

PubMed2004

Liver lesions of visceral larva migrans due to Ascaris suum infection: CT findings.

The purpose of this study was to analyze computed tomographic (CT) findings of hepatic lesions due to Ascaris suum infection. CT of the liver in three patients, all of whom had immunoserologically confirmed A. suum infection, were retrospectively reviewed. Twenty-five lesions were identified in total. Two radiologists analyzed CT findings in a consensus fashion, with particular interest in the margin, shape, and location of the lesions. Hepatic lesions were ill-defined (22 of 25), small (3-35 mm; average, 11 mm), and nodular (18 of 25) or wedge (three of 25) in shape. Most were located in periportal (16 of 25) or subcapsular (six of 25) regions. Hepatic nodules due to visceral larva migrans of A. suum were located mainly in periportal or subcapsular regions, which may represent periportal eosinophilic granuloma, its pathologic feature. The results were considered to represent the pathophysiology of this entity.

Adult↗

PubMed2004

Filter cigarette smoking and lung cancer risk; a hospital-based case--control study in Japan.

Recent changes in the histology of lung cancer, namely a relative increase of adenocarcinoma compared to squamous cell carcinoma, might be due to a temporal shift from nonfilter to filter cigarettes. To investigate the association between type of cigarette and lung cancer by histological type, we conducted a case-control study in Japan, comprising 356 histologically confirmed lung cancer cases and 162 controls of male current smokers, who provided complete smoking histories. Overall, logistic regression analysis after controlling for age and prefecture revealed decreased risk, as shown by adjusted odds ratios, for both squamous cell carcinoma and adenocarcinoma among lifelong filter-exclusive smokers as compared to nonfilter or mixed smokers. This decrease was greater for squamous cell carcinoma than for adenocarcinoma. Among men under 54 years, filter-exclusive smokers displayed increased risk of adenocarcinoma, but decreased risk of squamous cell carcinoma. The recent shift in histology from squamous cell carcinoma to adenocarcinoma, particularly among younger smokers, might be due to changes in cigarette type. However, among subjects aged 65 years or more, no differences in histological type appeared related to type of cigarette smoked, implying that other factors are associated with increases in adenocarcinoma among older Japanese population.

Adenocarcinoma↗

PubMed2004

Effects of bisphosphonates on joint damage and bone loss in rat adjuvant-induced arthritis.

OBJECTIVE AND DESIGN: Examination of the effects of bisphosphonates on joint damage and generalized bone loss. MATERIALS: Adjuvant-arthritis was induced by injection of Mycobacterium butyricum into the footpad of the right hind paw of Lewis rats (8 animals/group) on day 0. TREATMENT: Arthritic rats were treated with the vehicle (saline), etidronate or alendronate (subcutaneously, daily 5 times a week for 3 weeks from day 1 to day 21). Experiment-1: Etidronate (0.1, 0.5, 2.5, 12.5 mg/kg) or alendronate (0.02, 0.1, 0.5, 2.5 mg/kg), Experiment-2: Etidronate (2.5, 5, 10mg/ kg) or alendronate (0.001, 0.01, 0.1 mg/kg). METHODS: In the adjuvant-injected side of the hind limbs, paw swelling was evaluated at 1-week intervals, and bone mineral density (BMD) in the proximal tibia, histopathology and radiographical findings in the tibio-tarsal region were evaluated at the time of sacrifice (on day 21). RESULTS: In all treatment schedules, both bisphosphonates significantly prevented paw swelling and bone loss. Alendronate reduced paw swelling at higher doses (over 0.1 mg/ kg) compared with its effect on BMD decrease (over 0.001 mg/kg). In contrast, etidronate reduced paw swelling and joint damage at doses similar to those (over 2.5 mg/kg) prevented BMD decrease. CONCLUSIONS: Both etidronate and alendronate are effective in reducing arthritic damage, but their effective dose ranges for inflammatory responses and BMD decrease clearly differ; i.e., the etidronate dose ranges for anti-inflammatory and anti-resorptive effects are similar, whereas the dose range for anti-inflammatory effects of alendronate is 100-fold higher than that for its anti-resorptive effects.

Alendronate↗

PubMed2004

The microsatellite alleles on chromosome 1 associated with essential hypertension and blood pressure levels.

Essential hypertension (EH) is thought to be a polygenic disease. Several candidate genes of this disease have been investigated in studies using polymorphic genetic markers, but some studies have failed to show any association of EH with these genes. In this experiment, we used microsatellite markers on chromosome 1, and performed an association study between EH and control subjects. Genomic DNA was amplified with fluorescently labelled primers from the Applied Biosystems PRISM linkage mapping set HD-5 comprising 63 highly polymorphic microsatellite markers with an average spacing of 4.5 cM. We isolated three loci showing significant differences: D1S507, D1S2713 and D1S2842. The P-values of the allele with the greatest post hoc contributions in D1S507, D1S2713 and D1S2842 were 0.0008, 0.0062 and 0.0084, respectively. All these values were significant after Bonferroni correction. Furthermore, we found that the three microsatellite alleles were associated with the levels of systolic blood pressure. These data suggest that there are at least the three susceptibility loci for EH on chromosome 1, and that a case-control study using microsatellite markers on genomewide basis is a useful method for isolating the susceptibility loci of multifactorial disorders.

Alleles↗

PubMed2004

Expressions of parathyroid hormone-related protein (PTHrP) and PTH/PTHrP-receptor (PTH/PTHrP-R) in gastrointestinal stromal tumours (GISTs), leiomyomas and schwannomas.

BACKGROUND: Gastrointestinal stromal tumours (GISTs) are rare, c-kit and CD34 positive, and different from other mesenchymal tumours of the gastrointestinal tract (e.g. leiomyomas and schwannomas). The purpose of this study was to investigate the roles of parathyroid hormone-related protein (PTHrP) and parathyroid hormone/parathyroid hormone-related protein-receptor (PTH/PTHrP-R) in the growth and differentiation of GISTs. METHODS: Nineteen GISTs, six leiomyomas and five schwannomas were examined in this study. RESULTS: All of the GISTs and leiomyomas, and four of the schwannomas (80.0%) were positive for PTHrP. Immunohistochemical staining revealed that all of the leiomyomas, 90% of the GISTs and 80% of the schwannomas expressed PTH/PTHrP-R. Furthermore, both PTHrP and PTH/ PTHrP-R were expressed in the cytoplasm of identical cells in all of these tumours. CONCLUSION: Our results suggest that both PTHrP and PTH/PTHrP-R play an important role in the growth and differentiation of GISTs, leiomyomas and schwannomas.

Gastrointestinal Neoplasms↗

PubMed2004

Expression of Tie-1 and 2 receptors, and angiopoietin-1, 2 and 4 in gastric carcinoma; immunohistochemical analyses and correlation with clinicopathological factors.

AIMS: There is strong evidence that tyrosine kinases are involved in the regulation of tumour progression, cellular growth and differentiation. Recently, many kinds of tyrosine kinase receptors have been reported, and among them Tie-1 and 2 constitute a major class. Angiopoietin (Ang)-1 is known as a ligand of the Tie-2 tyrosine kinase receptor. The aim of this study was to determine the expression profile of Tie-1 and 2 and Ang-1, 2 and 4 in gastric adenocarcinoma. METHODS AND RESULTS: Eighty-nine cases of surgically resected human gastric adenocarcinoma were studied by immunohistochemistry. Of these, 60 (67.4%), 61 (68.5%), 69 (77.5%), 75 (84.3%), and 47 cases (52.8%) showed positive staining in the cytoplasm of carcinoma cells for the Tie-1 and 2 and Ang-1, 2 and 4 proteins, respectively. The expression of Ties and Angs was significantly correlated with several type of histological differentiation and several clinicopathological factors. CONCLUSIONS: Ties and Angs were highly expressed in human gastric adenocarcinoma cells. These findings suggest that the Tie-Ang receptor-ligand complex is one of the factors involved in the cellular differentiation and progression of human gastric adenocarcinoma.

Adenocarcinoma↗

PubMed2004

Tumor-suppressive activities by chemokines introduced into OV-HM cells using fiber-mutant adenovirus vectors.

In this study, fiber-mutant adenovirus vectors encoding chemokines, Ad-RGD-mCCL17, Ad-RGD-mCCL21 and Ad-RGD-mCCL22 were constructed. The insertion of integrin-targeting RGD sequence into fiber knob of adenovirus vectors notably enhanced the infection efficiency into tumor cells. Among three chemokine-encoding vectors evaluated, Ad-RGD-mCCL22 showed significant tumor-suppressive activity via transduction into OV-HM cells.

Adenoviridae↗

PubMed2003

A case of ischemic jejunal stricture after surgical reduction of intussusception.

A 15-year-old girl presented with small bowel obstruction due to ischemic jejunal stricture which developed three weeks after successful surgical reduction of an intussusception with a Peutz-Jeghers-type polyp as a lead point. The reduced jejunum had no macroscopic injury, and the stricture caused complete obstruction requiring jejunal resection.

Adolescent↗

PubMed2003

Dural arteriovenous fistula of the transverse sinus with concomitant ipsilateral meningioma.

A 69-year-old female complained of headache and tinnitus. Computed tomography, magnetic resonance imaging, and angiography showed a tumour in the right transverse sinus extending to the transverse-sigmoid sinus junction, a dural arteriovenous fistula (AVF), and right transverse-sigmoid sinus thrombosis with the downstream from the right sigmoid sinus involved by the tumour. Right external carotid angiography showed the tumour to be supplied by many branches of the right occipital artery, the posterior branches of the middle meningeal artery, and the posterior auricular artery, and the dural AVF fed by the occipital artery and the meningeal branches of the right vertebral artery. She underwent surgery via a combined right supra- and infratentorial approach. The tumour had invaded and blocked the right transverse sinus, which was resected. After surgery the patient was free of headache and tinnitus was diminished. Histological examination found that the tumour was a fibrous meningioma and that the orifice of the vein at the transverse sinus was blocked by the tumour. Serial follow-up cerebral angiography 2 months after surgery showed no change in the AVF, but 9 months after surgery confirmed disappearance of the AVF. This AVF was caused by occlusion of the right transverse sinus by the meningioma and was an acquired lesion.

Aged↗

PubMed2002

An evaluation of chest X-ray screening for lung cancer in gunma prefecture, Japan: a population-based case-control study.

In order to evaluate the efficacy of annual chest X-ray screening for lung cancer, a case-control study was conducted in Gunma Prefecture, Japan. Population-based annual lung cancer screening programmes have been conducted by the local government in Gunma Prefecture since the mid-1970s. A total of 121 case subjects, including 91 high-risk males and 30 non-high-risk females between the ages of 40 and 79 years who died of lung cancer from 1992 to 1997 were evaluated. A total of 536 controls (3-5 controls for each case) were matched to case subjects by gender, year of birth, address and smoking habits. Controls were selected from screening programme lists provided by the local governments. All case subjects were also included on these lists. The smoking-adjusted odds ratio (OR) of lung cancer death for those subjects screened within 12 months prior to diagnosis versus those not screened was 0.68 (95% confidence interval (CI): 0.44-1.05; P=0.084). When the analysis was conducted without matching case and control subjects by smoking habits, the OR was 0.79 (95% CI: 0.53-1.18). When stratified by histological type, the OR was 0.62 (95% CI: 0.31-1.24) for adenocarcinoma, and 1.01 (95% CI: 0.44-2.31) for squamous cell carcinoma. The results of this study suggest 20-30% of deaths attributable to lung cancer, especially adenocarcinoma, might be prevented by annual chest X-rays.

Adenocarcinoma↗

PubMed2002

Analysis of HLA in children with gelatin allergy.

Systemic immediate reactions including anaphylaxis to gelatin in vaccines have been reported. However, the number of such reports is very small compared with the number of children exposed to gelatin. The present study was designed to investigate whether susceptibility or resistance to gelatin allergy is associated with human leukocyte antigen (HLA) class II gene. Blood samples were obtained from 49 patients with gelatin allergy and specific IgE to gelatin. DNA-based HLA class II typing was performed to determine the DRB1, DQB1 and DPB1 alleles. Genotype frequencies were compared with those found in 240 unrelated controls. The frequency of DQB1*0303 (55.1%) was significantly higher in the patients than in the control subjects (32.1%). The frequency of DPB1*0402 was also significantly higher in the patients (32.7%) than in the control subjects (15.4%). On the other hand, the frequency of subjects carrying DRB1*15 (DRB1*1501 and DRB1*1502) was significantly lower among the patients group (18.4%) than among the controls (40.8%). We found that DQB1*0303 and DPB1*0402 were positively associated with the IgE response for gelatin, while DRB1*15 was negatively associated with it.

Child↗

PubMed2002

Mycobacterial infection in natural killer T cell knockout mice.

To gain a better understanding of the pathological role of natural killer (NK) T cells in murine tuberculosis, NKT knockout (KO) mice (J(alpha)281(-/-)mice) were utilized. Eight-week-old NKT KO mice of BALB/c origin and wild-type (WT) mice were infected with Mycobacterium tuberculosis Kurono strain by the airborne route using an airborne infection apparatus, and their capacity to control mycobacterial growth, granuloma formation, and cytokine production were examined. The NKT KO mice developed granulomatous lesions in the lungs; there was no statistically significant difference in pulmonary granuloma size between NKT KO and WT mice (p<0.01). The average CFU values increased 3 weeks post-infection, but decreased 9 and 11 weeks post-infection, in the lungs of NKT KO mice. When stimulated with Kurono strain in vitro, splenic cells from NKT KO mice produced less IFN-gamma than did those from WT mice. Expression of mRNA for IL-2, IL-4, IL-6, IL-10 and IL-12 p40 was slightly lower in NKT KO mice compared with WT mice. Our data indicate that NKT cells play a detrimental role in late-phase mycobacterial infection, although Th1 cells are essential in early-phase mycobacterial infection.

Animals↗

PubMed2002

Severe infantile measles encephalitis occurred three months after neonatal measles.

A 3-month-old girl who developed severe measles encephalitis after neonatal measles is reported. Her mother had measles when she was ten days old and she was admitted to our hospital with low grade fever, Koplik spot, and mild exanthema seventeen days after birth, and she recovered in 7 days without any complication. At three months of age, she was readmitted because of intractable seizures. The levels of IgM and IgG antibodies against measles in the cerebrospinal fluid were elevated. The measles virus genome, amplifying the region encoding the nucleocapsid protein, was detected from the brain specimen by reverse transcriptase-polymerase chain reaction. Magnetic resonance imaging showed a focal destructive lesion and diffuse cerebral atrophy. The electroencephalogram did not show periodic synchronous discharges. Although the neonatal measles was believed to be relatively mild in severity, the possible development of measles encephalitis should be carefully monitored in an infant who had neonatal measles.

Encephalitis, Viral↗

PubMed2002

Measles virus genome detected up to four months in a case of congenital measles.

UNLABELLED: To determine how long the measles virus genome was detected in a patient with congenital measles, the peripheral blood mononuclear cells were tested for 203 d. The measles virus genome was detected up to 140 d. CONCLUSION: The period for which the measles virus genome was detected in this patient with congenital measles was much longer than in normal children with measles.

Female↗

PubMed2002

Mechanical and magnetic properties of nickel-dispersed tetragonal zirconia nanocomposites.

Effects of Ni dispersions on microstructure and mechanical properties have been studied for Y2O3-stabilized tetragonal zirconia (Y-TZP)/Ni nanocomposites with Ni dispersion up to 10 vol%. Composites were successfully fabricated by reducing and hot-pressing Y-TZP/NiO powder mixtures. Fracture strength was significantly improved from 1.5 GPa for monolithic Y-TZP to 1.9 GPa for nanocomposites with a small addition of Ni (1-2 vol%). Magnetic properties of Y-TZP/Ni nanocomposites were also investigated. Magnetization curves of Y-TZP/Ni nanocomposites showed typical hysteresis loops of soft magnetic materials, whereas coercivity was much larger than that of pure Ni metal. A new function arising from magnetomechanical effects of metallic Ni is also discussed for the present nanocomposites.

Compressive Strength↗

PubMed2001

Electrophysiologic and hemodynamic effects of apomorphine in dogs.

Apomorphine is a dopamine receptor agonist used as an emetic, for Parkinson's disease, and for treating erectile dysfunction. This study was conducted to monitor cardiovascular function in dogs given the standard emetic dose (0.05 mg/kg) or 10 times that. Measurements were made during baseline and at 1, 5, 15, 30, 45, and 60 min after iv administration. There were no changes produced by the 0.05 mg/kg dose of apomorphine except for a decrease in mean systemic arterial pressure (AoPm) at the 1 through 15 min recordings. For the 0.5 mg/kg dose, there were reductions in systemic vascular resistance at the 1 and 5 min recordings and in AoPm at the 1 through 60 min recordings. Although not significant, when AoPm fell, heart rate, stroke volume, and cardiac output tended to increase. Action potentials were recorded from superfused Purkinje and endocardial ventricular fibers while exposed to 10(-9) to 10(-5) M apomorphine (10(-10) M is considered therapeutic and 10(-7) M is considered lethal). There were no changes in action potential characteristics of Purkinje fibers, but action potential duration at 90% repolarization prolonged approximately 10-12% in endocardium at concentrations of 10(-6) M and greater. At the usual emetic dose (0.05 mg/kg) apomorphine resulted in no signs of cardiovascular toxicity and, at 0.5 mg/kg, cardiovascular changes were minimal. The emetic dose is higher than that for Parkinson's disease or erectile dysfunction; thus apomorphine appears to be a safe compound for clinical use in dogs and by extrapolation to man.

Action Potentials↗

PubMed2001

Monocyte chemoattractant protein-1-dependent increase of V alpha 14 NKT cells in lungs and their roles in Th1 response and host defense in cryptococcal infection.

To elucidate the role of NKT cells in the host defense to cryptococcal infection, we examined the proportion of these cells, identified by the expression of CD3 and NK1.1, in lungs after intratracheal infection with Cryptococcus neoformans. This population increased on day 3 after infection, reached a peak level on days 6-7, and decreased thereafter. In Valpha14 NKT cell-deficient mice, such increase was significantly attenuated. The proportion of Valpha14 NKT cells, detected by binding to alpha-galactosylceramide-loaded CD1d tetramer, and the expression of Valpha14 mRNA increased after infection with a similar kinetics. The delayed-type hypersensitivity response and differentiation of the fungus-specific Th1 cells was reduced in Valpha14 NKT cell-deficient mice, compared with control mice. Additionally, elimination of this fungal pathogen from lungs was significantly delayed in Valpha14 NKT cell-deficient mice. Production of monocyte chemoattractant protein (MCP)-1 in lungs, detected at both mRNA and protein levels, increased on day 1, reached a peak level on day 3, and decreased thereafter, which preceded the increase in NKT cells. Finally, the increase of total and Valpha14(+) subset of NKT cells after infection was significantly reduced in MCP-1-deficient mice. Our results demonstrated that NKT cells, especially Valpha14(+) subset, accumulated in a MCP-1-dependent manner in the lungs after infection with C. neoformans and played an important role in the development of Th1 response and host resistance to this fungal pathogen.

Animals↗