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Biomedical subjects

S Nakamura

Publications and source records attributed to S Nakamura.

At least 325 records · Page 18Linked to original sources
PubMed2001

Requirement of B7-mediated costimulation in the induction of experimental autoimmune anterior uveitis.

PURPOSE: To study the role of costimulatory signaling through the CD28-B7 interaction in experimental autoimmune anterior uveitis (EAAU). METHODS: Naive Lewis rats were immunized with insoluble melanin-associated antigen (MAA) derived from bovine iris and ciliary body. CTLA4-Fc, a recombinant protein comprised of the extracellular domain of human CTLA4 bound to mouse IgG2a Fc, was used to block the CD28-B7 interaction. A mutant version (CTLA4-Fc-mutant) was used as a control. The effect of CTLA4-Fc on the in vivo induction of disease with MAA was studied. Subsequently, the mechanism by which CTLA4-Fc blocked the interaction of CD28 and B7 was investigated in vivo, using the adoptive transfer of T cells derived from CTLA4-Fc-treated rats, and in vitro, using the proliferative response and cytokine production of MAA-T cells in the presence of CTLA4-Fc. RESULTS: CTLA4-Fc markedly reduced the incidence and severity of EAAU in Lewis rats after sensitization with MAA. The adoptive transfer of sensitized T cells from CTLA4-Fc-treated donors did not induce EAAU in naive recipients. CTLA4-Fc inhibited the expansion of antigen-specific MAA-T cells and the production of TNF-alpha. CONCLUSIONS: The costimulatory signal delivered through CD28-B7 is required for the induction and pathogenesis of EAAU. In the absence of this signal, antigen-specific expansion of MAA reactive T cells as well as production of TNF-alpha is inhibited. Abrogation of this costimulatory signal may be an important therapeutic option for EAAU.

Abatacept↗
PubMed2001

[Postoperative right ventricular function after repair of tetralogy of Fallot with respect to the method of right ventricular outflow tract reconstruction].

We evaluated postoperative right ventricular function in the sixty-four consecutive patients with tetralogy of Fallot underwent total correction. The patients were divided to three groups according to the method of right ventricular outflow tract reconstruction: transannular patching (TA group; n = 31); right ventricular outflow patching with preservation of pulmonary valve ring (RV group; n = 12) and transatrial-transpulmonary approach without right ventriculotomy (no-RV group; n = 21). The early results of postoperative cardiac catheterization and echocardiography were compared among the three groups. Degree of pulmonary regurgitation was significantly low in the RV group and no-RV group compared with TA group (p < 0.005). Right ventricular ejection fraction was the highest in the no-RV group (p < 0.002). The repair without right ventriculotomy for tetralogy of Fallot can provide the best results with respect to postoperative right ventricular function.

Cardiac Surgical Procedures↗
PubMed2001

Usefulness of long axis M-mode echocardiographic measurements for optimum dialysis in patients on maintenance hemodialysis: comparison with changes in plasma levels of atrial natriuretic peptide and brain natriuretic peptide.

UNLABELLED: It has been suggested that analyzing the left ventricular long axis motion can result in the sensitive detection of cardiac functional disorders. AIM: To evaluate the usefulness of left ventricular long axis indices in managing patients on maintenance hemodialysis. METHODS: Eighteen hemodialysis patients (mean age 51 +/- 10 years) as well as 16 healthy persons (mean age 49 +/- 9 years) were examined. Echocardiograms were recorded, and the plasma concentrations of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were measured before and after a session of hemodialysis. The following parameters were measured: the left atrial diameter (LAD) and end-diastolic left ventricular diameter (LVDd) from M-mode echocardiograms, the end-diastolic LV volume (LVEDV) and ejection fraction (EF) from 2-D echocardiography, the E/A ratio from transmitral Doppler, the atrial systolic excursion of long axis motion of the mitral ring (ALAM) and maximal lengthening rate of the mitral ring toward the left atrium during the early diastolic phase (MLRe) from LV long axis M-mode echocardiograms. RESULTS: LAD, LVDd, LVEDV, and ALAM showed a positive correlation with plasma levels of ANP and BNP. EF, the E/A ratio, and MLRe showed a negative correlation with plasma levels of ANP and BNP. Changes in ALAM and plasma levels of ANP during hemodialysis were larger in the subgroup of ALAM < or = 0.55 cm before hemodialysis than in the subgroup of ALAM < 0.55 cm before hemodialysis. CONCLUSION: These results indicate that the left ventricular long axis index can detect a disorder of left ventricular diastolic function, and that a hemodialysis patient whose ALAM before hemodialysis is < 0.55 cm is dialyzed with good volume control conditions.

Adult↗
PubMed2001

[Gross spreading multiple extramedullary plasmacytomas to the skin in the terminal stage of multiple myeloma].

A 71-year-old woman with an 8-year history of IgG-kappa type multiple myeloma was admitted because of severe lumbago and bone destruction. Her serum IgG level was elevated to 5,565 mg/dl at admission. Despite treatment with doxorubicin, vincristine, dexamethasone, melphalan and interferon-alpha, the response was transient. Nine months later, multiple skin nodules appeared on her chest, abdominal wall and right thigh accompanied by elevation of the serum IgG level. Response to combination chemotherapy with cyclophosphamide, ranimustine, vincristine and prednisolone was also transient. The skin tumors on the bilateral thighs, especially on the left side, acquired chemotherapy resistance and gradually enlarged. Although the serum IgG level was maintained by chemotherapy within the range 1, 790-2,676 mg/dl, the skin tumors on the left thigh had spread very rapidly and appeared "rock-like". The enlarged tumors caused necrosis with erosions and oozing hemorrhage. A skin biopsy from the tumors on the left thigh showed plasmacytoma in which infiltration of large anaplastic plasma cells was observed. The patient died of sepsis 8 months after the skin tumors initially developed. This is a very rare case of multiple myeloma in which multiple large plasmacytomas of the skin developed and grew aggressively at the terminal stage after a long-term indolent course.

Aged↗
PubMed2001

[Acceptable definition of peripheral early lung cancer].

This study was conducted to evaluate the outcome of 88 patients who underwent surgical resection for peripheral non-small cell lung cancers less than 20 mm in diameter. Twenty-one cases with lesions smaller than 10 mm had no lymph node metastasis, intrapulmonary metastasis, pleural dissemination, or distant metastasis. The 5-year survival rate of them was 100%. However, 67 patients with tumors larger than 10 mm showed lymph node metastasis in 14 cases, intrapulmonary metastasis in 3, pleural dissemination in 2 and distant metastasis in 1. And the 5-year survival rates of patients with tumor dimensions of < or = 15 mm and < or = 20 mm were 77.9% and 74.4%, respectively. In addition, patients having adenocarcinoma categorized A and B by Noguchi's classification had no lymph node metastasis, intrapulmonary metastasis, pleural dissemination, or distant metastasis, and showed 100% of 5-year survival rate. To be defined as early cancers in terms of curability, it is thought that the 5-year survival rate of the patients with them is over 95%. Therefore, these results suggest that tumors smaller than 10 mm or adenocarcinoma less than 20 mm in diameter diagnosed as Noguchi's A and B are considered as peripheral early lung cancers.

Adult↗
PubMed2001

Antiapoptotic activity is dispensable for insulin-like growth factor I receptor-mediated clonogenic radioresistance after gamma-irradiation.

PURPOSE: The purpose of this study was to evaluate the relationship between apoptotic activity and clonogenic radiosensitivity in vitro using an insulin-like growth factor I receptor (IGF-IR) signaling model, which is known to exert tumorigenic and antiapoptotic effects. EXPERIMENTAL DESIGN: We used mouse embryo fibroblast cell lines expressing either human IGF-IR [R+(Wt) and R+] or the marker gene alone [R-(puro)]; these cell lines were derived from R- cells, which are deficient in IGF-IR. After gamma-irradiation, apoptotic activity was determined by the presence of DNA fragmentation and caspase-3-, -8-, and -9-like activities. Clonogenic radiosensitivity was determined by a colony-forming assay. RESULTS: R+(Wt) and R+ cells expressed similar levels of IGF-IR, transducing phosphorylation signals to major downstream substrates on insulin-like growth factor I stimulation. R+ cells were resistant to the induction of apoptosis after gamma-irradiation; however, both R+(Wt) and R-(puro) cells demonstrated significant DNA fragmentation and increase in caspase-3-, -8-, and -9-like activities. Both R+(Wt) and R+ cells were radioresistant (to a similar extent) compared with R-(puro) cells as measured by a colony-forming assay. Clonogenic radioresistance was not influenced by the inhibition of Akt/protein kinase B through treatment with wortmannin at low concentrations specifically inhibiting phosphatidylinositol 3'-kinase. CONCLUSIONS: Our findings indicate that apoptotic activity does not necessarily predict clonogenic survival after exposure to ionizing radiation. This study provides clinical implications in the evaluation of apoptotic activities observed during the course of radiotherapy to predict accurate tumor response or local control.

Androstadienes↗
PubMed2001

[A case of cholinergic urticaria with epileptic seizure and abnormalities on electroencephalogram].

We report a 10-year-old boy with cholinergic urticaria associated with epileptic seizure and abnormalities on electroencephalogram. In March 1999, many red wheals developed over the entire body during exercise and at increased body temperature. In April, systemic red wheals developed during exercise. Simultaneously, loss of consciousness was noted for 2 to 3 minutes. After the patient's body was cooled, consciousness improved, and these exanthemas disappeared. In the Department of Dermatology, his illness was diagnosed as cholinergic urticaria. Neurologically, a heat tolerance and mental strain induced cholinergic urticaria, followed by generalized epilepsy(clonic seizure). In addition, electroencephalography revealed high voltage polyspikes and 14 Hz positive spikes. The mechanism involved in cholinergic urticaria associated with epileptic seizure was assumed as follows: sweat-promoting stimuli, such as heat, exercise and tension, stimulate the autonomic center in the diencephalon or brain stem, and excitation in the autonomic center is transmitted to the efferent sympathetic nerve, causing cholinergic urticaria; when the intensity of stimulation is high, the autonomic center exhibits abnormal activities and causes epileptic seizure.

Autonomic Nervous System↗
PubMed2001

[Small lymphocytic lymphoma/chronic lymphocytic leukemia with t(11;14)].

A 83-year-old woman was referred to our hospital because of swollen lymph nodes, marked splenomegaly, and bone marrow abnormality. Histological examination of the lymph nodes revealed characteristic findings for small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL). The immunophenotype of the tumor cells was CD5+, 10-, 19+, 20+, 23-, IgM+D+. Interphase fluorescent in situ hybridization (FISH) detected t(11;14), and immunohistochemical studies demonstrated cyclin D1 expression. In both SLL/CLL and mantle cell lymphoma (MCL), the normal counterpart of the tumor cells is thought to be CD5-positive B1 cells. The present case may therefore have been borderline between SLL/CLL and MCL.

Aged↗
PubMed2001

[Efficacy of pilsicainide for the long-term prevention of paroxysmal atrial fibrillation: analysis based on the time of onset].

OBJECTIVES: This study evaluated the efficacy of long-term pilsicainide therapy to maintain sinus rhythm in patients with paroxysmal atrial fibrillation in terms of the time of onset. METHODS: A total of 81 patients (57 men, 24 women, mean age 65 +/- 11 years) were given pilsicainide (150 mg/day) after cardioversion. Paroxysmal atrial fibrillation was divided into three types by the time of onset: the day type (AM 7:00-PM 5:00, n = 13), the night type (PM 5:00-AM 7:00, n = 12) and the mixed type (n = 56). Mean follow-up period was 35.4 +/- 16.1 months. RESULTS: There was a higher incidence of hypertension in the day type (38.5%) and the mixed type (48.2%) than in the night type (8.3%) (p < 0.05). The periods for maintenance of sinus rhythm in the day type, the night type and the mixed type were 15.7 +/- 5.0, 9.9 +/- 2.7 and 5.7 +/- 1.3 months, respectively, with a significant difference between the day type and the mixed type (p < 0.01). Actuarial event free-rates at 1, 3, 6, 9 and 12 months were 76.9%, 69.2%, 61.5%, 53.8% and 53.8% respectively, in the day type, 83.3%, 66.7%, 58.3%, 33.3% and 33.3%, respectively, in the night type and 58.9%, 37.5%, 26.8%, 25.0% and 21.4%, respectively, in the mixed type. There was a significant difference in the rate at 12 months between the day type and the mixed type (p < 0.05). CONCLUSIONS: These results suggest that pilsicainide has a high degree of efficacy for maintaining normal sinus rhythm in patients with the day type onset of paroxysmal atrial fibrillation.

Aged↗
PubMed2001

[Indications for and techniques of hepatic vein reconstruction in hepatectomy for hepatocellular carcinoma].

The indications for hepatic vein reconstruction (HVR) in resection of segments 7 and 8 for hepatocellular carcinoma (HCC) have been controversial. Although right hepatic vein ligation may not cause complications in some patients, hepatic parenchymal congestion and liver dysfunction occur in others. We performed HVR using autovein grafts in 6 HCC patients, patch grafts in 3, and direct anastomosis in 1, respectively. From this experience, we consider that HVR may be indicated in patients with a discolored hepatic area after hepatic vein ligation, and without inferior right hepatic vein and intrahepatic venous communication. Furthermore, although repeat hepatectomy has resulted in improved survival in patients with recurrent hepatic tumors, when the right hepatic vein has already been ligated, numerous intrahepatic communicating vein anastomoses develop. In repeat hepatectomy in such patients, uncontrollable massive bleeding from hepatic veins occurs. Therefore, HVR is recommended to maintain the previous hepatic vein anatomy. Recently, the indications for HVR have been studied to prevent hepatic vein congestion and liver dysfunction in both the remant and graft livers in living-related donor partial liver transplantation from the standpoint of hemodynamics. Additionally, the technique of direct hepatic vein anastomosis is presented.

Carcinoma, Hepatocellular↗
PubMed2001

[Relationship between the fecal mutagenicity and metal content, smoking habit and dietary intake].

OBJECTIVE: The study was carried out to collect basic data on exposure of mucous cells of the large intestine to mutagens by investigating the genotoxicity of fecal samples from the urban population. Simultaneously, relations with food intake (food groups and nutritive components), lifestyle factors and fecal metal content was investigated. METHODS: A total of 199 self-collected fecal samples from middle aged healthy volunteer living in urban areas of Osaka city were freeze-dried and ground in a mill. The mutagenicity of aqueous extracts of the ground samples was measured by the umu-test. Metal content of the feces was analysed by atomic absorption spectrophotometlly. On the day previous to the feces collection, the contents of meals were recorded and confirmed by interview with a dietitian. Quantification of nutritive components was carried out using the 4th edition of the Japan Food Standard Vomposition Table. RESULTS: Mutagenicity of feces was higher in males than in females, and in those aged 40-49 years than 50-69 years in males but not females. Large differences were found for content of 8 metals in the feces; concentrations were in the decreasing order of calcium, potassium, magnesium, sodium, zinc, iron, manganese and copper, the highest being 20.4 mg for calcium and the lowest was 53.5 micrograms for copper. Between the metal contents and mutagenicity, values for zinc and iron showed positive correlations and for sodium a negative correlation under S9(+) conditions. A weak but significant correlation was observed between the numbers of cigarettes smoked per day and S9 (+) mutagenicity. However we could not find any relation with food groups or nutritive components. CONCLUSION: It is well known that human feces contain many mutagens and carcinogens and that these can act directly on the mucous membrane of large intestine. Therefore, it is very important to estimate exposure levels. From the present data we can conclude that relations between mutation-activity of the feces and diet are complex. Their elucidation will require a large number of volunteers who have similar living conditions to obtain appropriate data.

Adult↗
PubMed2001

Repair of articular cartilage on the surface of heat-treated bone by transplantation of cultured chondrocytes.

The present study addresses clinical problems associated with the degeneration of articular cartilage, which occurs when heat-treated bone with articular cartilage is used for re-implantation after resection of malignant bone tumors adjacent to the joints. We therefore evaluated the effect of transplantation of chondrocytes embedded in collagen gel on the surface of heat-treated bone. A cylindrical complex of bone and articular cartilage 6 mm in diameter was resected from rabbits' patellar grooves and treated in saline at 60 degrees C for 30 min. In Group A, articular cartilage was resected from the complex and the remaining bone was returned to the patellar groove. Then, autologous chondrocytes cultured in collagen gel were transplanted and covered with periosteum. As controls, the original complex of heat-treated bone and articular cartilage (Group B) and heat-treated bone directly covered with periosteum (Group C) was returned to the patellar groove. In Group A, histological study showed that round cells were mainly observed and the matrix was well stained with Safranin O in the repair tissue after 24 weeks. The repair tissue was as thick as the adjacent normal cartilage. Immunohistological study detected type-II collagen and chondroitin-6-sulphate (3B3+) in the matrix of the repair tissue, but not type-I collagen. The repair tissue was consequently cartilaginous in Group A. The repair tissue was not cartilaginous or was degenerative in the control groups. We believe that this modality of heat-treated joints will contribute to limb salvage reconstruction after resection of malignant bone tumors adjacent to the joints.

Animals↗
PubMed2001

[Clinical evaluation of 8 patients with pulmonary tuberculosis in a community hospital without restricted tuberculosis wards].

The clinical features of 8 patients with pulmonary tuberculosis under treatment in the Koebaru Central Hospital, a community hospital without restricted tuberculosis wards, between 1992 and 2000 were evaluated. The major findings in the present study were: i) recently, the number of elderly patients with reactivated pulmonary tuberculosis has increased, ii) none of the patients showed respiratory symptoms, and 3 patients had negative Mantoux skin tests, iii) only one patient showed cavities on chest radiography, and iv) none of the expectorated sputum samples was smear-positive for Mycobacterium tuberculosis. Smears of intrabronchial sputum sampled using a fiberoptic bronchoscope from pulmonary lesions in patients without any symptoms were useful for establishing the diagnoses. Considering all aspects, it is important to perform aggressive evaluations, even for elderly patients, utilizing a fiberoptic bronchoscope for early diagnosis of pulmonary tuberculosis and to prevent nosocomial infections.

Aged↗