Biomedical subjects

N Shinohara

Publications and source records attributed to N Shinohara.

At least 19 recordsLinked to original sources

PubMed2004

Contribution of CD4+ and CD8+ T cells and interferon-gamma to the progress of chronic rejection of kidney allografts: the Th1 response mediates both acute and chronic rejection.

T cells mediating chronic rejection (CR) of human kidney allografts were characterized by comparing them with those mediating acute rejection (AR). Two lines of analysis were performed using biopsy specimens (23 CR and 8 AR). First, the extent of infiltration of CD4+ and CD8+ T cells into allografts was assessed from mRNA expression of CD4 and CD8. The group of CR specimens was not significantly different from the group of AR specimens in terms of the extent of CD4+ and CD8+ T cell infiltration, underlining the importance of the immunological contribution to the progress of CR. Second, Th1/Th2 polarization in infiltrating T cells was investigated by measuring mRNA expression of interferon gamma (IFN-gamma; a Th1 cytokine) and interleukin 4 (IL-4; a Th2 cytokine). IFN-gamma expression was detected in most CR specimens, and was not significantly different between the group of CR specimens and the group of AR specimens. On the other hand, IL-4 expression was detected in only two CR specimens and one AR specimen; from its pathological features, the AR in this last case was concomitant with CR. These results suggest that most cases of CR and of AR are mediated by Th1 mechanisms, although some cases of CR show features of both Th1 and Th2.

Acute Disease↗

PubMed2004

Clonality analysis of T cells mediating acute and chronic rejection in kidney allografts.

The clonality of T-cell populations mediating acute and chronic rejection (AR and CR, respectively) of kidney allografts was ascertained by investigating the diversity of TCRBV genes expressed by allograft-infiltrating T cells. Both oligoclonality and polyclonality cases were found in biopsy specimens of AR as well as CR. These results indicated that the T-cell clonality in each specimen did not correlate directly with the mode of rejection. When AR and CR specimens were compared, however, the CR specimen group was significantly more polyclonal (or less oligoclonal) than the AR group. This result may reflect the higher chance of epitope spreading in the more slowly progressing CR than in AR.

Clone Cells↗

PubMed2004

Bending strength and depth of cure of light-cured composite resins irradiated using filters that simulate enamel.

This study evaluates the light-attenuating effects of enamel on the properties of light-cured restorative resins using simple experimental filters. Three filters were designed to replicate the light transmittance characteristics of 0.5, 1.0 and 1.5 mm thick human enamel. The bending strength, depth of cure, and levels of residual monomer for 12 shades of three commercial light-cured composite resins were examined. These resins were cured either using direct irradiation from a light source or irradiation through one of the filters. For all materials, the bending strength and depth of cure of specimens irradiated through a filter were lower and the levels of residual monomer were higher than those found in specimens irradiated directly. The results indicate that the light-attenuating effect of enamel reduces the polymerization efficiency, resulting in poorer mechanical properties of light-cured composite resins.

Composite Resins↗

PubMed2002

Effect of photo-irradiation on hardness of soft lining materials for denture base.

Nine photo-activated acrylic-type (EPL) soft lining materials were produced experimentally to examine their durability. The purpose of this study was to investigate the effect of photo-irradiation on the hardness of experimental soft lining materials. The hardness (Hex) of the nine EPLs was increased 4.3-170.1% by exposing them to light. The effect of irradiation on the Hex of the EPLs was remarkable when the material contained much ethylmethacrylate, together with smaller amounts of di-n-butyl phthalate. Moreover, the Hex tended to increase for EPLs in which the liquid portion contained less di-n-butyl phthalate or more ethanol (Et). The weight change ratio (Wc) was greater for EPL specimens containing less Et. The Wcs ranged from 0.118 to 0.661% after 8 weeks. These results showed that the Hexs of six of the EPLs were approximately equal to those of four commercially available soft lining materials, and these six EPLs may have properties favouring their use in clinical dentistry.

Absorption↗

PubMed2002

Isotopic ratio of 129I/127I in seaweed measured by neutron activation analysis with gamma-gamma coincidence.

129I is a long-lived (1.6 x 10(7) y) radionuclide that is produced in nature as the result of spontaneous fission of heavy elements and reaction of xenon with cosmic rays. Recently, however, artificial sources from nuclear power plants and nuclear test explosions have become a significant component of environmental radioactive iodine. Coincidence gamma-ray detection using Ge detectors makes it possible to simultaneously resolve the numerous gamma-rays produced by neutron activation. In this study, the coincidence gamma-ray detection technique was combined with neutron activation analysis to determine the radioactive iodine composition of seaweed. The ratio of 129I/127I in this common Japanese food item collected from the Ibaraki prefecture has been derived without the need for radiochemical purification. The isotopic ratio of 129I/127I in Kajime algae is 3.5(5) x 10(-10).

Gamma Rays↗

PubMed2001

Adenovirus-mediated gene therapy for bladder cancer in an orthotopic model using a dominant negative H-ras mutant.

It has been suggested that abnormal Ras function is important in the carcinogenesis and progression of bladder cancer. Our aim was to investigate the efficacy of transurethral inoculation of an adenovirus expressing the dominant negative H-ras mutant N116Y against orthotopically implanted human bladder-cancer cells in nude mice. We used a replication-defective adenovirus vector containing the beta-galactosidase gene (AdCMV-LacZ) as a control and the N116Y gene (AdCMV-N116Y) as the therapeutic vector under the transcriptional control of the cytomegalovirus promoter. We initially investigated the in vitro growth-suppressive effects of AdCMV-N116Y on 2 human bladder-cancer cell lines, KU-7 and UMUC-2. Thereafter, we examined the inhibitory effects of AdCMV-N116Y on the 2 orthotopically implanted cell lines in nude mice. Intravesically created, orthotopic human bladder cancers were established in female KSN athymic nude mice with 1x 10(7) cancer cells. Then, 2, 3 and 4 days following implantation, 1 x 10(9) pfu of AdCMV-LacZ or AdCMV-N116Y were administered transurethrally. In vitro growth assays revealed significant growth suppression (>95%) with apoptosis of target cells treated with AdCMV-N116Y compared to AdCMV-LacZ. Transurethral inoculation of AdCMV-N116Y into the bladder brought about a significant reduction in size (73% to 90%) and number (47% to 78%) of orthotopically implanted human bladder tumors compared to AdCMV-LacZ or PBS. Normal mucosa in nude mice had minor inflammation with the infiltration of mononuclear cells. Our results suggest that gene therapy via transurethral inoculation of AdCMV-N116Y holds promise for the treatment of human bladder cancer.

Adenoviridae↗

PubMed2001

Antigen-presenting hybridoma cells expressing MHC antigens of the LEW rat.

Towards the eventual purpose of facilitating analyses of specificities and functions of LEW rat T lymphocytes involved in the induction and development of organ-specific autoimmune disorders, hybridoma cells expressing class I and class II MHC antigens of LEW rat have been developed. B cell hybridomas produced between a murine B cell tumor M12.4.5 and stimulated LEW B cells expressed high levels of LEW class II MHC antigen but the expression of LEW class I MHC antigens on these cells was rather low. The B hybridoma cells were capable of presenting soluble protein antigens to LEW CD4(+) T cells. Furthermore, The use of this hybridoma revealed antigen-specific cytolytic activity of rat CD4(+) T cells. T cell hybridomas produced between murine thymoma BW5147 and LEW T cells expressed class I MHC antigens of the LEW rat. The expression was confirmed by surface staining and specific cytolysis by rat allogeneic CTL.

Animals↗

PubMed2001

Immunohistochemical analysis of E-cadherin, alpha-catenin, beta-catenin, gamma-catenin, and neural cell adhesion molecule (NCAM) in chordoma.

AIMS: The epithelioid features seen in chordoma are unique among mesenchymal tumours. However, no detailed analysis regarding cell-cell communication has been conducted in this epithelioid tumour. The aims of this study were to investigate cell-cell communication in chordoma. METHODS: By means of immunohistochemical techniques that incorporated a panel of monoclonal antibodies against cell adhesion molecules (CAMs), including E-cadherin, alpha-catenin, beta-catenin, gamma-catenin, and neural cell adhesion molecule (NCAM), the expression of CAMs was studied in 15 specimens of chordoma and eight specimens of chondrosarcoma. RESULTS: Most chordoma specimens showed some positive immunoreactivity for all the CAMs examined. For the various CAMs investigated, between two and five cases showed diffuse immunoreactions, indicating well preserved expression. Well preserved expression of all the CAMs examined was limited to only one case, thus indicating that the expression of CAMs was decreased in most of the chordoma specimens; however, no significant correlation was found between the decreased expression of CAMs and the histological grade of malignancy, cellular growth pattern, or clinical parameters in chordoma. In chondrosarcoma, only a few specimens showed positive immunoreactivity for CAMs and the expression of E-cadherin, beta-catenin, gamma-catenin, and NCAM was seen more frequently in the chordoma specimens than in the chondrosarcoma specimens. CONCLUSIONS: These results suggest that the expression of CAMs is associated with the formation and maintenance of chordoma tissue architecture, just as it is in other epithelial tumours or normal tissue. Immunohistochemistry for CAMs was found to be of diagnostic value for discriminating chordoma from chondrosarcoma, and these markers could be used along with the cytokeratins, which are already used for this purpose.

Adult↗

PubMed2001

Testicular-sparing surgery for the prepubertal testicular tumor. Experience of two cases with large cell calcifying Sertoli cell tumors.

PURPOSE: We review prepubertal germ cell tumors of testis in our institute and the Japanese registry and present 2 cases with a large cell calcifying Sertoli cell tumor (LCCSCT) and discuss the possibility of testis-sparing surgery. MATERIALS AND METHODS: Incidence, age, pathology and clinical stages of prepubertal germ cell tumors are surveyed for 30 years at our department and 10 years of the malignant tumor registry of the Japanese Society of Pediatric Surgery. Two representative prepubertal boys with LCCSCT are presented. One of them was treated by partial orchiectomy. RESULTS: The majority of testicular germ cell tumors in the prepubertal age were composed of embryonal cell carcinoma/yolk sac tumors or teratoma, occurred in preschool age, were limited to clinical stage I and did not metastasize irrespective of histology. Benign behavior which included recovery from hormonal derangement, no tumor recurrence and negative antisperm antigen was observed in 2 cases with LCCSCT who underwent either radical orchiectomy or partial orchiectomy. CONCLUSION: Partial orchiectomy should be considered as a standard option in prepubertal schoolboys with a testicular mass if surgically feasible. This surgical treatment is safe and preserves fertility and is psychologically advantageous. It is not recommended for yolk sac tumors that may recur, however they are rare in prepubertal boys and can be differentiated preoperatively by prudent evaluation.

Adolescent↗

PubMed2001

Impact of nephron-sparing surgery on quality of life in patients with localized renal cell carcinoma.

OBJECTIVES: The aim of the study is to evaluate the impact of nephron-sparing surgery on postoperative quality of life (QOL) in patients with localized renal cell carcinoma, compared with radical nephrectomy. METHODS: From 1986 to 1996, a total of 66 patients with localized small renal cell carcinoma <4 cm in diameter and a functioning contralateral renal unit underwent radical nephrectomy (n = 51) or nephron-sparing surgery (n = 15). Of these, 50 patients evaluated various dimensions of QOL using standardized self-rating questionnaires, EORTC QLQ-C30. RESULTS: There is no significant difference in 5-year overall survival between the nephron-sparing surgery group and the radical nephrectomy group. With regard to postoperative QOL, patients who underwent nephron-sparing surgery showed a significantly higher score on physical function than patients treated with radical nephrectomy (p<0.05). Nephron-sparing surgery was additionally superior to radical nephrectomy in terms of fatigue, sleep disturbance, pain and constipation. CONCLUSION: Selected patients with localized, small, unilateral renal cell carcinoma and a normal contralateral kidney will benefit from nephron-sparing surgery.

Adult↗

PubMed2001

Recombinant human erythropoietin therapy for autologous blood donation in rheumatoid arthritis patients undergoing total hip or knee arthroplasty.

The effect of recombinant human erythropoietin on autologous blood donation was investigated in 73 rheumatoid arthritis patients who underwent hip or knee arthroplasty. Autologous blood donation of 400 mL was successful with recombinant human erythropoietin (12,000 U per week), and no homologous blood was required. The mean period of blood collection was 33.8 days. Mean hemoglobin levels were 9.7 g/dL before treatment, 10.7 g/dL before surgery, and 10.2 g/dL after surgery. This study confirmed recombinant human erythropoietin is effective for enabling preoperative blood donation in rheumatoid arthritis patients.

Aged↗

PubMed2001

[Contrivance for frozen section diagnosis of early minute lung cancer during operation].

We reported the technique of pathological diagnosis for minute lung cancer lesion of early stage during operation. Target lesion for our technique may be less than 1 cm in size and not be detected by palpation. Our technique may superior to usual method of frozen section of tissue specimen without fixation. At first, resected lung specimen was fixed by injection of 20% formalin solution subsequent warming by microwave oven for 40 seconds. Almost all lesions may be detected in proper thickness of specimen. Specimen was washed out and steeped in the 20% of sucrose solution for 30 to 60 seconds in order to avoid crystallization of water that was contained within lung specimen. Then thin sliced section of specimen was made by Cryostat in usual method. The minute cancer lesion was able to detect more easy than usual method of making frozen section of specimen. Formalin fixed and sucrose steeped frozen section may be able to evaluate the surgical margin from cancer exactly than the section made by non-fixed specimen.

Frozen Sections↗

PubMed2000

Use of an implanted marker and real-time tracking of the marker for the positioning of prostate and bladder cancers.

PURPOSE: A real-time tracking radiotherapy was investigated to assess its usefulness in precise localization and verification of prostate and bladder cancers. METHODS AND MATERIALS: The real-time tracking radiation therapy (RTRT) system consists of implantation of a 2.0-mm gold marker into a clinical target volume (CTV), three-dimensional radiation treatment planning (3DRTP) system, and the use of two sets of diagnostic x-ray television systems in the linear accelerator room, image processing units, and an image display unit. The position of the patient can be corrected by adjusting the actual marker position to the planned marker position, which has been transferred from the 3DRTP and superimposed on the fluoroscopic image on the display unit of the RTRT system. The position of the markers can be visualized during irradiation and after treatment delivery to verify the accuracy of the localization. Ten patients with prostate cancer and 5 patients with bladder cancer were examined using this system for the treatment setup on 91 occasions. RESULTS: After manual setup using skin markers, the median of absolute value of discrepancies between the actual position of the marker and the planned position of the marker for prostate cancer was 3.4 (0.1-8.9) mm, 4.1 (0.2-18.1) mm, and 2.3 (0.0-10.6) mm for the lateral, anteroposterior, and craniocaudal directions, respectively. The 3D median distance between the actual and planned positions of the marker was 6.9 (1.1-18.2) mm for prostate cancer and 6.9 (1.7-18.6) mm for bladder cancer. After relocation using RTRT, the 3D distance between the actual and planned position of the marker was 0.9 +/- 0.9 mm. Median 3D distances between actual positions after treatment delivery and planned positions were 1.6 (0.0-6.3) mm and 2.0 (0.5-8.0) mm during daily radiotherapy for the marker in patients with prostate cancer and bladder cancer, respectively. CONCLUSION: We believe the new positioning system can reduce uncertainty due to setup error and internal organ motion, although further improvement is needed for the system to account for the rotational and elastic changes of the affected tissues.

Humans↗

PubMed2000

Four-dimensional treatment planning and fluoroscopic real-time tumor tracking radiotherapy for moving tumor.

PURPOSE: To achieve precise three-dimensional (3D) conformal radiotherapy for mobile tumors, a new radiotherapy system and its treatment planning system were developed and used for clinical practice. METHODS AND MATERIALS: We developed a linear accelerator synchronized with a fluoroscopic real-time tumor tracking system by which 3D coordinates of a 2.0-mm gold marker in the tumor can be determined every 0.03 second. The 3D relationships between the marker and the tumor at different respiratory phases are evaluated using CT image at each respiratory phase, whereby the optimum phase can be selected to synchronize with irradiation (4D treatment planning). The linac is triggered to irradiate the tumor only when the marker is located within the region of the planned coordinates relative to the isocenter. RESULTS: The coordinates of the marker were detected with an accuracy of +/- 1 mm during radiotherapy in the phantom experiment. The time delay between recognition of the marker position and the start or stop of megavoltage X-ray irradiation was 0.03 second. Fourteen patients with various tumors were treated by conformal radiotherapy with a "tight" planning target volume (PTV) margin. They were surviving without relapse or complications with a median follow-up of 6 months. CONCLUSION: Fluoroscopic real-time tumor tracking radiotherapy following 4D treatment planning was developed and shown to be feasible to improve the accuracy of the radiotherapy for mobile tumors.

Computer Systems↗

PubMed2000

Impact of Helicobacter pylori infection on gastric cancer incidence in a general Japanese population: the Hisayama study.

BACKGROUND: Several nested case-control studies have reported the potentially causal relationship between Helicobacter pylori infection and the development of gastric cancer. However, there has been no prospective study evaluating this issue. The purpose of this study is to examine the impact of H pylori infection on gastric cancer occurrence in a general Japanese population (Hisayama, Japan) stratified according to sex, using a prospective study design. METHODS: A total of 2602 subjects aged 40 years or older (1070 men; mean age, 57 years; 1532 women; mean age, 59 years) without a history of gastrectomy or gastric cancer were classified according to the status of the serum IgG antibodies to H pylori and observed prospectively for 9 years from 1988. RESULTS: Infection of H pylori was more common in men (71.5%) than in women (62.5%; P<.001). The age-adjusted incidence of gastric cancer for men (5.3 per 1000 person-years) was 4-fold higher than that for women (1.3; P<.001). In men, the age-adjusted incidence of gastric cancer was significantly higher in the subjects with H pylori infection than in those without it (6.2 vs 2.5; relative risk, 2.59 [95% confidence interval, 1.03-6.50]), whereas no significant difference was observed in women (1.2 vs 1.1; relative risk, 0.99 [95% confidence interval, 0.36-2.68]). These results were similar even after controlling for other risk factors in multivariate analysis. It was estimated that 40.1% of gastric cancers for men in this cohort were attributable to H pylori infection. CONCLUSION: A significant relationship exists between infection with H pylori and subsequent occurrence of gastric cancer for men but not for women in this Japanese population.

Adult↗

PubMed2000

Coreceptor function of mutant human CD4 molecules without affinity to gp120 of human immunodeficiency virus.

Despite extensive mutational studies on the human CD4 molecule and its affinity to human immunodeficiency virus (HIV) envelope glycoprotein gp120, coreceptor functions of such mutant molecules have only been examined by indirect measurement of their affinity to class II major histocompatibility complex (MHC) molecules. In this report, coreceptor functions of mutant human CD4 molecules, which have no or reduced affinity to an HIV envelope protein, gp120, were assessed in a murine T cell receptor/class II MHC recognition system. The substitution of human C" beta strand with the murine homologous segment resulted in the loss of the coreceptor function as well as in the complete loss of gp120 binding capacity, corroborating the consensus that Phe-43 in C" beta strand plays crucial roles in both situations. However, simultaneous replacement of the C'-C" loop along with the C" beta strand by homologous murine segments rescued the coreceptor function, whereas gp120 binding capacity remained negative. Further analysis indicated that insertion of lysine between Gly-41 and Ser-42 can partially compensate for the coreceptor function lost by the Phe-43 --> Val mutation. Although the coreceptor function of these mutant CD4 molecules in a human T cell recognition system is yet to be determined, these observations necessitate a re-evaluation of the role played by Phe-43 in coreceptor function. Examination of the sensitivities of the mutant CD4 molecules expressed on HeLa cells to infection by a T cell-tropic HIV-1 strain indicated that only those mutants that had completely lost gp120 binding capacity were resistant to the infection. All mutants having whole C" substitution, irrespective of additional substitutions or their coreceptor functions, were resistant to the infection.

Amino Acid Sequence↗

PubMed2000

Cell death-associated translocation of plasma membrane components induced by CTL.

In the very early stages of target cell apoptosis induced by CTL, we found that fluorescence of labeling probes of the target plasma membrane, such as N-(3-triethylammoniumpropyl)-4-(p-dibutylaminostyryl)pyridin ium dibromide (FM1-43), was translocated into intracellular membrane structures including nuclear envelope and mitochondria. This translocation was associated with the execution of CTL-mediated killing, because neither the CTL-target conjugation alone nor the binding of noncytotoxic Th2 clone with target cell was sufficient to provoke the process. Although FM1-43 translocation was observed in perforin-mediated cytotoxicity, examinations with several other dyes failed to detect the evidence for membrane damages that may cause influx of the dye. Moreover, the translocation was also observed in Fas-dependent apoptosis. These data indicate that the translocation precedes the damage of plasma membrane and intracellular organella in the course of apoptotic cell death and may represent the existence of a membrane trafficking that mediates the translocation of plasma membrane components in the early onset of apoptotic cell death.

Animals↗

PubMed2000

Isolation of a vascular cell wall-specific monoclonal antibody recognizing a cell polarity by using a phage display subtraction method.

Using a strategy consisting of (i) the isolation of cell walls from synchronously differentiating cells of Zinnia, (ii) the generation of mAbs with an antibody phage display method, and (iii) screening with a subtraction method, we isolated mAbs recognizing vascular development-specific cell wall components without prior antigen identification. One of the isolated mAbs, designated CN 8, recognized a cell wall component contained in the hemicellulosic fraction. Immunohistochemical analyses showed that the CN 8 epitope was localized to the cell wall of immature tracheary elements and xylem parenchyma cells. In immature tracheary elements, the CN 8 epitope had a polarized localization pattern regardless of whether the cells are formed as parts of vessels in situ or as single tracheary elements in vitro, suggesting that cell polarity autonomously formed on the cell wall may function in tracheary element differentiation.

Amino Acid Sequence↗