Search PubMed⌕ Search

Biomedical subjects

Y Nishimura

Publications and source records attributed to Y Nishimura.

At least 415 records · Page 23Linked to original sources

Dermatophagoides farinae-1-derived peptides and HLA molecules recognized by T cells from atopic individuals.

Der f 1, the group I allergen in Dermatophagoides farinae extracts, is a major source of inhalation allergens in Japan. Using the mixture of a panel of overlapping synthetic peptides that spread over the entire Der f 1 molecule, we found that polyclonal Der f 1-specific short-term T cell lines prepared from peripheral blood of 6 individuals allergic to Der f who carry most of the common HLA haplotypes seen in the Japanese population can respond to 16 different peptides. Eight of 16 peptides stimulated T cells of more than 2 donors, regardless of the HLA types. Proliferative responses of four T cell lines were markedly inhibited by mAb HU4 (anti-HLA-DRB1+B5), one was inhibited partially by HU11 (anti-HLA-DQ4+5+6), and one was inhibited fully by a combination of HU4, L243 (anti-HLA-DRB1+B4) and PLM16 (anti-HLA-DRB3) but only partially by each of these mAbs. One of these T cell lines, DT, of which the proliferative response was partially inhibited by HU11, was cloned. Indeed, the T cell clones were restricted by DQ6 molecules on an HLA-DRB1*1501-DRB5*0101-DQA1*0102-DQB1*0602 haplotype. These results indicate that patients' T cells recognize Der f 1 in association mainly with HLA-DRA/DRB1, but that DQAI/DQB1, DRA/DRB3 and possibly DRA/DRB4 gene products also function as antigen-presenting molecules. Thus, although some peptides have a more potent T cell-stimulatory activity than others, the T cell receptor ligands formed with the Der f 1 molecule are highly heterogeneous.

Allergens↗

Identification of Dermatophagoides farinae-2-derived peptides and class II HLA molecules recognized by T cells from atopic individuals.

Der f2, the group 2 allergen of Dermatophagoides farinae, is one of the major inhalation allergens in Japan. Using the mixture of a panel of overlapping synthetic peptides that spread over the entire Der f2 molecule, we found that polyclonal Der f2-specific short-term T cell lines prepared from peripheral blood mononuclear cells of 5 individuals allergic to Der f who carry most of the common HLA haplotypes seen in the Japanese population can respond mainly to 7 different peptides. Distribution of the T cell epitopes on Der f2 was not identical with that on Der p2. Five of 7 peptides stimulated T cells of more than 2 donors, regardless of HLA types. Inhibition patterns by anti-HLA class II mAbs were heterogenous in proliferative responses of each cell line, three were mainly inhibited by anti-HLA-DR mAb, and the others were inhibited by anti-HLA-DQ mAb. One of these T cell lines, SM, of which the proliferative response was partially inhibited by anti-HLA-DQ mAb, was cloned. Indeed, the T cell clone SM4.6 was restricted by DQ6 molecules encoded for by an HLA-DRB1*1502-DRB5*0102-DQA1*0103-DQB1*0601 haplotype. These results indicate that patients' T cells recognize Der f2 in association with a variety of HLA-DR or HLA-DQ as antigen-presenting molecules. Thus, although some peptides do have a more potent T cell stimulatory activity than others, the TCR ligands formed with the Der f2 molecule are highly heterogeneous, a factor also noted in Der f1-specific T cell lines in our previous study.

Allergens↗

Bronchial responsiveness to inhaled histamine in canine pulmonary congestion.

To elucidate the role of bronchial hyperresponsiveness (BHR) in pulmonary congestion, an inhaled histamine provocation test was performed in dogs with acute pulmonary congestion, and the role of vagal nerve activity and arachidonic acid metabolites on bronchial responsiveness was evaluated. We assessed BHR with the provocation concentration of histamine causing a 100% increase in pulmonary resistance (PC100) in an openchest anesthetized and tracheotomized canine model before and after left atrial balloon inflation. Twenty-two mongrel dogs (8-14 kg) were anesthetized with sodium thiopental (15-20 mg/kg) and mechanically ventilated with positive end-expiratory pressure at 3 cmH2O. A Foley catheter was inserted into the left atrium to cause pulmonary congestion, in which mean left atrial pressure was increased to 18 mmHg. In 6 dogs, histamine provocation was examined before and after pulmonary congestion was effected. Intravenous indomethacin (1 mg/kg) administration and vagotomy were performed in 5 dogs. In pulmonary congestion, PC100 was significantly decreased both before and after vagotomy and after indomethacin administration. We conclude that pulmonary congestion augments bronchial responsiveness to inhaled histamine and that neither vagotomy nor indomethacin administration prevents bronchial hyperresponsiveness in pulmonary congestion. These findings suggest that bronchial hyperresponsiveness in pulmonary congestion is related to another factor such as bronchial edema.

Administration, Inhalation↗

Accelerating effect of chitosan intake on urinary calcium excretion by rats.

The effect of chitosan on calcium (47Ca) metabolism was investigated in rats. The whole-body retention of 47Ca by rats fed on a 5% chitosan diet was significantly decreased when compared with that of rats fed on a cellulose diet, but showed no significant difference from that of rats fed on a fiber-free diet. Although there was no significant difference in the fecal excretion of 47Ca between the chitosan group and the cellulose or fiber-free group, the urinary excretion of 47Ca was significantly increased in the chitosan group when compared with the cellulose group. These results suggest that dietary chitosan would affect the calcium metabolism in animals.

Administration, Oral↗

Apoptosis enhanced by soluble factor produced in feline immunodeficiency virus infection.

Feline immunodeficiency virus (FIV)-infected cells have been shown to undergo apoptosis by treatment with tumor necrosis factor alpha (TNF-alpha). This study detected a soluble factor which enhanced the apoptosis induced by TNF-alpha treatment. The sensitivity to TNF-alpha in the induction of apoptosis in a feline fibroblastoid cell line (CRFK) cells was significantly enhanced when the culture supernatant of FIV-infected CRFK cells or plasma samples from FIV-infected cats was added to the culture. These findings suggested that FIV infection induces production of a soluble factor which enhances CRFK cells sensitivity to TNF-alpha induction of apoptosis both in vitro and in vivo. This factor may contribute to the loss of lymphocytes in cats infected with FIV.

Animals↗

Relationship between changes of bone mineral content and twelve-minute walking distance in men with chronic obstructive pulmonary disease: a longitudinal study.

Cross-sectional studies have revealed that bone mass is reduced in patients with chronic obstructive pulmonary disease (COPD). To elucidate the factors influencing bone mass in COPD, we measured whole body bone mineral content (BMC) by dual energy X-ray absorptiometry (DXA), pulmonary function, and twelve-minute walking distance (TMD) in men with COPD, who had been monitored for at least one year. We studied the body composition in 22 male patients with COPD and 19 age-matched male controls (age 72.6 +/- 7.2 vs 67.5 +/- 10.1 years, mean +/- SD). COPD patients showed a significantly lower body weight (49.3 +/- 5.7 vs 57.9 +/- 3.5 kg, respectively), body mass index (18.9 +/- 2.1 vs 22.1 +/- 1.3 kg/m2) and BMC (1.9 +/- 0.4 vs 2.2 +/- 0.4 kg) than controls. The changes in BMC were significantly correlated with TMD (r=0.53, p<0.02). These results demonstrate that decreased exercise capacity, at least in part, accounts for acceleration of bone mass loss in COPD patients.

Aged↗

Prolongation of ischaemic tolerance of rat skeletal muscle by trehalose.

Trehalose is a disaccharide that can stabilise cell membranes under various stressful conditions. We have studied the effect of trehalose on the ischaemic tolerance of fat skeletal muscle flaps. A rat gracilis model was used to evaluate the prolongation of ischaemic preservation of the modified solution in which trehalose was substituted for glucose in Euro-Collins solution. Four groups of animals were studied. In two groups, flaps were preserved in Euro-Collins solution or trehalose Euro-Collins solution for various ischaemic intervals (6, 12, 24, 48, 72, and 96 hours). In two additional groups, after storage for various periods in the two solutions, muscle flaps were replanted into the original animals with microvascular anastomoses, and were investigated by light and electron microscopy on the seventh postoperative day. Trehalose Euro-Collins solution significantly prolonged ischaemic tolerance compared with Euro-Collins solution alone at 24 and 48 hours.

Animals↗

[Pleural-origin malignant lymphoma in an elderly patient with chronic empyema and infection with the Epstein-Barr virus].

A 73-year-old woman with a long-standing history of right-sided chronic empyema complained of lumbago. An artificial pneumothorax had been induced to treat pulmonary tuberculosis about 40 years previously. The year after she began to complain of lumbago, a tumor mass over the right anterior chest wall had grown rapidly. Pathologic examination revealed that it was a malignant lymphoma (Non-Hodgkin's lymphoma, diffuse large cell, B cell type). Chemotherapy with cyclophosphamide, adriamycin, vincristine, and prednisolone, and then radiation therapy were given. The patient responded very well. The tumor mass on the surface of the chest wall disappeared completely. She was alive and well and there was no evidence of recurrence at the seven-month follow-up examination. Analysis with the polymerase chain reaction showed that the tumor contained DNA of the Epstein-Barr virus. The chronic empyema and local infection with the Epstein-Barr virus might have been a factor in the development of the malignant lymphoma.

Aged↗

Effect of bed rest immobilization on metabolic turnover of bone and bone mineral density.

Immobilization induces abnormal bone metabolism and severe decalcification of bone. To investigate the effect of middle-term immobilization on bone metabolism, we studied 10 young healthy males and females during bed rest for 20 days. Bone mineral density (BMD) rapidly decreased in both lumbar and metacarpal bones. No bone showed consistent BMD alterations, partial increase and partial decrease, and both lumbar and metacarpal bone showed similar rapid BMD change. Urinary excretion of pyridinoline tended to slightly increase by day 10, and to decline by day 20 (mean +/-SE: 34.2 +/-7.4, 26.3+/-4.6 nmol day-1, respectively). Neither alkaline phosphatase (isoform III) nor tartrate-resistant acid phosphatase, changed, suggesting that in the early stage of immobilization bone matrix in some part might increase or be resorbed without any activation of osteoblast or osteoclast, resulting in rapid calcification or decalcification, respectively.

Absorptiometry, Photon↗

Psychological stress induced by 20 days bed rest.

We investigated the changes of the psychological state during 20 days bed rest (BR) in 10 young participants,(5 males and 5 females, age; 19-24 yrs). Psychological assessment was accomplished by the following authorized 3 indices: 1) Zung's Self-rating Depression Scale, 2) Cornell Medical Index, and 3) Goldberg's General Health Questionnaire. Zung's Self-rating Depression Scale is a indicator for depression, and the other two indices were used for detecting signs of neurosis. The results from Zung's Self-rating Depression Scale and the General Health Questionnaire in this study indicated a tendency toward depression and neurosis developing during BR, respectively. The scores in the Cornell Medical Index did not change. Urinary excretion of 17-hydroxycorticosteroid increased significantly, indicating that BR immobilization induced an important psychological stress. We were unable to determine which factors caused the changes in psychological state during BR, immobilization insert or personal problems.

17-Hydroxycorticosteroids↗

[Aspiration pneumonia during the endotracheal intubation on the occasion of bladder perforation by TUR].

We report on two cases of aspiration pneumonia which developed during the endotracheal intubation after bladder perforation during TUR. The first case was a 79 y.o. male, who underwent TUR-P and lithotripsy under spinal and epidural anesthesia. The second case was a 69 y.o. male, who had undergone TUR-Bt under nitrous oxide-oxygen-enflurane anesthesia. General anesthesia was selected to perform an laparotomy when the diagnosis was made. They vomited a considerable amount of gastric content just after giving the drugs for induction. The chest X-rays revealed signs of aspiration pneumonia. These X-ray findings improved in a week using antibiotic therapy. Although TUR is performed as scheduled, vomiting may occur in the case of unexpected bladder perforation, which can cause aspiration pneumonia. In such emergency, we should insert a nasal tube before induction, press the cricoid (crush induction), or intubate with the patient awake.

Aged↗

Optimal lipiodol volume in transcatheter arterial chemoembolotherapy for hepatocellular carcinoma: study based on lipiodol accumulation patterns and histopathologic findings.

To clarify the optimal dose of Lipiodol (Andre Guerbet, Aulnay-sous-Bois, France) during Lipiodol-transcatheter arterial embolization (L-TAE) and segmental L-TAE used to treat hepatocellular carcinoma, we studied the relationship between the volume of Lipiodol used during these procedures and the necrosis rates in resected specimens, as well as the correlation with the Lipiodol accumulation pattern based on the computed tomography findings (L-CT) and the volume of Lipiodol in resected and nonresected cases after L-TAE or segmental L-TAE. The L-CT and the dose of Lipiodol injected (mL) were studied correlatively in 198 cases (28 resected cases and 170 nonresected cases; tumor size < or = 5 cm in 52 cases and > 5 cm in 118 cases) that underwent L-TAE and in 80 cases (14 resected cases and 66 nonresected cases, tumor size < or = 5 cm in 52 cases and > 5 cm in 14 cases) that underwent segmental L-TAE. The L-CT was classified into four types: type I, homogeneous accumulation (type Ia, accumulation around the tumor; type Ib, no accumulation around the tumor); type II, partial defect; type III, sporadic accumulation; and type IV, punctate or no accumulation. In the 42 resected cases (L-TAE, 28 cases; segmental L-TAE, 14 cases), type I was seen in 68% (Ib, 100%) of the L-TAE cases and 93% (Ia, 79%; Ib, 14%) of the segmental L-TAE cases. The necrosis rate of the cases with type Ib L-CT was 90% to 100%, and all type Ia cases showed complete necrosis. In the 236 nonresected cases (L-TAE, 170 cases; segmental L-TAE, 66 cases), the volume of Lipiodol injected correlated with the L-CT type. In the L-TAE cases with a tumor size < or =5 cm, the frequency of the injected Lipiodol volume (D) being greater than the tumor diameter (d) (D > or = d) was 90%, and 87% of the cases with D > or = d showed type Ib L-CT. In the group whose tumor diameter (d) was more than 5 cm, the frequency of D > or = d was 25%, and 70% of the cases of D > or = d were type Ib. The frequency of D < d was 75%, and in 13% of these cases the L-CT was type Ib and the maximum dose was approximately 10 mL. In segmental L-TAE using the same dose of Lipiodol as in L-TAE, the frequency of D > or = d was 83%, and 93% of those cases showed type I, including 85% of type Ia. There was a correlation between the L-CT type and the necrosis rate, and type I, especially Ia in segmental L-TAE, showed complete necrosis in almost all cases. In L-TAE, standards for the optimal dose of Lipiodol are thought to be as follows: D > or = d in cases with d < or = 5, and slightly D < d and 10 mL maximally in cases with d > 5. In segmental L-TAE using the same dose of Lipiodol as in L-TAE, enhancement of the therapeutic effect was seen compared with L-TAE. This is surmised to have been because of the higher Lipiodol volume with anticancer agents per unit volume of the tumor in segmental L-TAE.

Carcinoma, Hepatocellular↗

[The effect of vasodilator on the occurrence of postoperative shivering and the fall of core temperature].

We evaluated the effect of intraoperative vasodilator therapy on the occurrence of postoperative shivering and the fall of core temperature during 37 abdominal operations by the stepwise multiple regression analysis. As the vasodilator, we used PGE1 at the dose of 0.02-0.05 microgram.kg-1.min-1. In the vasodilator group, postoperative peripheral surface temperature was high and the occurrence of shivering was low. And intraoperative and postoperative core temperatures were not affected by that therapy. From these results, we conclude that intraoperative vasodilator therapy suppressed the occurrence of postoperative shivering without a fall of core temperature.

Adult↗

[High-dose conformal radiotherapy for glioblastoma multiforme].

The purpose of this study was to evaluate the impact of administering high doses by rotational multi-leaf collimator (MLC) conformal radiation therapy. From 1984 to 1995, thirty-five consecutive cases with glioblastoma multiforme were treated using rotational MLC conformal therapy. There were 23 men and 12 women, with an average age of 45 years (12-73 years). Median Karnofsky performance score was 80(30-100). Median tumor volume was 56 cc (8-800 cc). All patients underwent surgical intervention (only biopsy in one, partial resection in 13, subtotal resection in 18, and gross total resection in three). Radiation dose ranged from 60 to 80 Gy (mean 68.5 Gy) in 21 patients treated before 1991, and was 90 Gy in the 14 patients treated thereafter. Biweekly intravenous chemotherapy was also administered in both arms. The 1-year, 2-year, and 5-year survival rates were 72%, 43%, and 21%, respectively. Residual tumor volume was the only statistically significant factor for survival by multivariable analysis. The five-year survival rate of patients with residual tumors 2 cm or less in diameter was as high as 44%. Local failure was observed in 15 of the 18 patients in the lower dose group, whereas it was observed in only 4 of the 10 patients in the higher dose group. The difference was statistically significant. Rotational conformal therapy in combination with intensive surgical resection showed a favorable outcome. However, increased dose did not lead to higher survival rate.

Adult↗

[Binding-peptide motifs of HLA class II molecules susceptible to autoimmune diseases].

Recent advances in knowledge of crystal structures of MHC class II molecules has advanced understanding of the molecular basis for interactions between peptides and HLA class II molecules. Polymorphism of HLA class II molecules influences structures of peptides bound to HLA class II molecules. To elucidate mechanisms for statistical association between particular HLA class II alleles and susceptibility to autoimmune diseases, it is important to identify self peptides presented by disease-susceptible HLA class II molecules and triggering disease-causative autoreactive T cells. In this study, we tried to identify self-peptides triggering autoimmune diseases including rheumatoid arthritis, insulin autoimmune syndrome, insulin dependent diabetes mellitus and infant-onset myasthenia gravis. Susceptibility to all of these diseases in the Japanese population are known to be strongly associated with particular HLA-DR-DQ haplotypes unique to Asians, and clinical features of some of these diseases are different between Caucasians and Asians including Japanese. We investigated differences in binding-peptide motifs between disease susceptible and non-susceptible HLA class II molecules and predicted candidates of autoimmune self-peptides carrying binding-motifs to disease-susceptible HLA class II molecules. Indeed the major epitope for insulin-autoreactive CD4+ T cell was successfully identified by this strategy. We also found heterogeneity in immunogenetic background between Western type and Asian type of multiple sclerosis. Our data indicated that our strategy is useful to identify autoimmune self-peptides, and it is suggested that not only disease-susceptible HLA class II but also self-peptides causing diseases are different between Caucasians and Asians. These differences may well correlate to different clinical manifestations of diseases between the two ethnic groups.

Amino Acid Sequence↗