Biomedical subjects

N Shioya

Publications and source records attributed to N Shioya.

At least 19 recordsLinked to original sources

PubMed2005

Characterization of new monoclonal antibodies against porcine lymphocytes: molecular characterization of clone 7G3, an antibody reactive with the constant region of the T-cell receptor delta-chains.

A battery of mouse monoclonal antibodies (mAbs) reactive with porcine peripheral blood (PB) leukocytes was generated. Among the mAbs, 6F10 was found to react probably with cluster of differentiation (CD)8 alpha-chain, while 7G3 and 3E12 were found to recognize gammadelta T-cells, as revealed by two-color flow cytometric and immunoprecipitation studies. 7G3 was shown to react with the constant (C) region of the T-cell receptor (TCR) delta-chain by the following facts: (1) 7G3 immunoprecipitated full-length TCR delta-chain protein fused with glutathione S-transferase (GST) produced by Esherichia coli and (2) 7G3 reacted with TCR delta-chain expressing Cos-7 cells transfected with either full-length or N-terminal deleted mutant cDNA, but did not react with Cos-7 cells transfected with C-terminal deleted mutant TCR delta-chain cDNA. All three mAbs produced high-quality immunostaining results on frozen sections, revealing a distinct distribution of gammadelta T-cells and CD8(+) cells. This report precisely characterizes mAbs against porcine TCR for the first time, facilitating molecular biological investigations of the porcine immune system.

Amino Acid Sequence↗

PubMed2000

Influence of castration on development of the thymus in neonatal male rats.

The influence of castration on the development of the thymus in neonatal rats was studied to elucidate when after birth the thymus comes under inhibitory regulation by the testis in rats. The relative and absolute weights of the thymus were measured five days after castration these cases. No excessive changes in the weights of the thymus with castration were observed by 31 days after birth. Significant changes in the thymus appeared in the relative weight at 36-day-castration. The absolute weight of the thymus was also significantly increased after 41-day-castration. These findings suggest that in rats the inhibitory regulation of the thymus by testis development does not appear before at least 31 days of age.

Aging↗

PubMed1999

Pretreatment of human keratinocyte sheets with laminin 5 improves their grafting efficiency.

Laminin 5 is essential in epithelial attachment to stromal tissues, suggesting that it might improve keratinocyte attachment in a variety of clinical situations. In this study, we examined the effect of exogenous laminin 5 upon the efficiency of transplantation of keratinocyte sheets in animal models. Keratinocyte sheets were prepared according to the method of Rheinwald & Green (1975). Purified laminin 5 was added to the sheets of group 1 (1.0 microg per cm2), Dulbecco's modified Eagle's medium alone was added to group 2. The sheets were grafted to the panniculus carnosus of nude mice (BALB/C nu/nu) (n = 12) and nude rats (Fisher 344) (n = 15). The take rate was assessed by measurement of the area of surviving epithelium at 7 d postgrafting. Laminin 5 bound the keratinocyte sheets of group 1. At 7 d postgrafting, the area of epithelialization of group 1 was significantly larger than that of group 2. Immunohistochemistry staining showed that collagen IV, laminin 5, and collagen VII stained more strongly at the dermal-epidermal junction in group 1 than in group 2. Integrin chains alpha6 and beta4 were similar in both groups. Electron microscopy at day 3 after grafting, showed the lamina densa of group 1 to be more continuous than in group 2. Pretreatment of cultured human keratinocyte sheets with laminin 5 improved the extent of epithelial coverage and increased the rate of neobasement membrane formation. The results suggest that laminin 5 promotes epithelial attachment by increasing the rate of basement membrane assembly.

Animals↗

PubMed1998

Histodifferentiation of hair follicles in grafting of cell aggregates obtained by rotation culture of embryonic rat skin.

We have previously reported reconstruction of hair follicles from a single cell suspension of rat fetal upper lip by a two-step culture method consisting of rotation and flotation cultures. Rotation sorted out the cells and flotation facilitated histodifferentiation. In the present study, we added grafting procedures to the previous method to see whether cell aggregates obtained this way were graftable, and whether the grafting promoted histodifferentiation. The aggregates before and after flotation were grafted, and differentiation of hair follicles comparable to those in vivo was confirmed 10 days after grafting. There was no difference in the degree of differentiation between the two kinds of grafts. The grafting procedure therefore resulted in an appreciable increase in histodifferentiation even when aggregates obtained after flotation were grafted.

Animals↗

PubMed1998

In vivo bioactivities and kinetic parameters of rat luteinizing hormone components: discrepancy between in vitro and in vivo assays.

Rat pituitary LH shows an electrical charge heterogeneity owing to their carbohydrate moiety. The biological potencies of these isoelectric components increase with increasing pI when examined by in vitro testosterone production in isolated rat Leydig cells. The present study was carried out to clarify if this tendency was also true with of in vivo action and to estimate their kinetic parameters. Seven isoelectric components of LH, i.e. X (pI 7.9), A (8.4), B (8.8), C (9.1), D (9.3), E (9.6) and F (9.8), were administered to cannulated adult male rats. Blood samples were serially collected over a 5 h period from the conscious animal, and rat LH and testosterone were assayed by RIA. The doses of a single component showed a linear relationship with the areas under the curve (AUC) of the blood LH. The testosterone AUC also correlated well with LH AUC. It was found that the components with lower pIs had longer half-lives and larger LH AUC, and smaller total body clearance rates with highly significant correlation coefficients. The in vivo bioactivities of the components expressed as testosterone AUC increased with decreasing pIs, indicating that the in vivo bioactivity was much influenced by the total body clearance rate. The intrinsic activities of the components were calculated as ratios of testosterone AUC to LH AUC where the effect of the clearance rate (or biological half-life) was eliminated. The intrinsic activities of components were not significantly different among the components except component X which showed a smaller activity. These data indicated that, with the exception of component X, an LH component with a lower pI has a longer biological half-life, resulting in a higher in vivo potency, quite contrary to the tendency of in vitro potency.

Animals↗

PubMed1997

Development of new wound dressing composed of spongy collagen sheet containing dibutyryl cyclic AMP.

Although cyclic AMP has been considered to regulate cell proliferation, the mechanism of this function is largely unknown. Recent studies suggest that cyclic AMP promotes the proliferation of skin cells in a dose-dependent manner. An ointment containing dibutyryl cyclic AMP has been used in the treatment of skin ulcers and found to be effective in promoting tissue repair. To search more efficacious wound management, the authors developed a new wound dressing composed of a spongy atelo-collagen sheet containing dibutyryl cyclic AMP. This wound dressing was evaluated in two types of animal tests. One is the application of the wound dressing to a full-thickness skin defect in order to evaluate the granulation tissue formation and the wound size reduction. The wound dressing was found to promote the granulation tissue formation and naturally reduce the wound size. The other test was the application of the wound dressing to the full-thickness skin defect, leaving behind a skin island in a central portion, in order to evaluate the epithelialization. This skin island left in a full-thickness skin defect was extremely enlarged. The enlargement of the skin island seems to be related to the epithelialization from the margin of the skin island as well as by the expansion of a skin island induced by contraction of the developed granulation tissue in the surrounding wound area. These results suggest that an atelo-collagen spongy sheet containing dibutyryl cyclic AMP is effective in promoting the granulation tissue formation and epithelialization.

Animals↗

PubMed1997

Unilateral multiple adenolymphomas originating in the parotid gland: a clinicopathological study.

The validity of Seifert's hypothesis about growth pattern of adenolymphomas has been evaluated in three of five patients with adenolymphomas of the parotid gland, who at the time of a parotidectomy, were found to have multiple unilateral adenolymphomas in the intraglandular lymph nodes. This evaluation, which was based on assessing the epithelial: lymphoid tissue ratio in excised adenolymphomas and the growth in tumor size, showed that there was no association between the histological changes in the epithelial:lymphoid tissue and the tumor size. Adenolymphomas seem to have no consistent growth pattern and develop independently. However, as multiple tumors were detected histopathologically in lymph nodes as small as 5 mm in diameter the importance of a detailed examination of patients with adenolymphomas is stressed, so that other tumours are not overlooked.

Adenolymphoma↗

PubMed1996

Cytotoxicity tests for antimicrobial agents using cultured skin substitutes fixed at interface of air and culture medium.

The present study is focused on a new cytotoxicity test using cultured dermal and epidermal sheets, which are fixed at the air and medium interface as a wound surface model. The cultured dermal sheet is composed of human fibroblasts and a collagen matrix, and the cultured epidermal sheet is composed of human keratinocytes and a collagen matrix. Each cultured sheet was fixed at the air and medium interface, over which a piece of test specimen was placed. The in vitro system created, provides a mimetic wound surface since during wound repair, fibroblasts are embedded in an extracellular matrix, while keratinocytes migrate and proliferate on provisional granulation tissue. The results thus obtained in this cytotoxicity test are useful for determining the efficacious amount of antimicrobial agent used in clinical cases.

Air↗

PubMed1995

Mixed cultures comprising syngeneic and allogeneic mouse keratinocytes as a graftable skin substitute.

Using inbred mouse strains C3H/He and BALB/c and an anti-class I MHC monoclonal antibody, we examined the graftability of mixed cultures composed of syngeneic and allogeneic mouse keratinocytes. Keratinocytes from neonatal C3H/He (syngeneic donor) and BALB/c (allogeneic donor) mice were cultured for 7 days, both individually and at the inoculum ratio of 1:1, 1:3, or 1:15. The resulting sheets of keratinocytes were implanted subcutaneously into adult C3H/He mice and morphological evaluation was made on the 4th, 7th, and 14th days after grafting. The control cultures of 100% allogeneic keratinocytes were rejected, whereas epidermal reconstruction without typical signs of rejection took place in all grafts derived from the mixed cultures, including the 1:15 cultures. However, immunofluorescence staining showed that, within the grafts, the allogeneic keratinocytes were gradually replaced by syngeneic cells. Thus, these results suggested that graftable skin substitutes may be produced by co-culturing a small amount of autologous keratinocytes with allogeneic keratinocytes, which are readily available.

Animals↗

PubMed1995

Evaluation of an allogeneic cultured dermal substitute composed of fibroblasts within a spongy collagen matrix as a wound dressing.

The purpose of this study was to examine whether epithelialisation is promoted when an allogeneic cultured dermal substitute is used as a biological wound dressing. The dermal substitute was prepared by plating fibroblasts on to a spongy collagen matrix, and then culturing them for 7 to 10 days. A new animal wound model was designed to measure re-epithelialisation quantitatively. A full thickness skin defect was made on the dorsum of each of 33 rats; the skin was excised, leaving a layer of pannicular carnosus with an island of intact skin in the central portion of the skin defect. In the first group of rats (n = 13), a piece of cultured dermal substitute was applied to the wound, and a medicated covering material was placed over it. Re-epithelialisation from the island of intact skin was monitored over a period of 7 days. In the second group of rats (n = 10), the wound was covered with an acellular collagen matrix in conjunction with the medicated covering material, and in the third group of rats (n = 10), the wound was covered with the medicated covering material alone. Both the macroscopic and histological findings indicated that the epithelial migration of the first group of rats was far more rapid than that in the other two groups. It comes to the conclusion that the application of this new fibroblastic cultured dermal substitute provided a good environment for the promotion of wound healing.

Animals↗

PubMed1994

Morphological aspects of LFA-1/ICAM-1 and VLA4/VCAM-1 adhesion pathways in human lymph nodes.

Monoclonal antibodies specific for the adhesion molecules participating in lymphocyte homing, lymphocyte function associated antigen-1 (LFA-1) and very late antigen 4 (VLA4), and their respective ligands, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), were used to characterize their expression pattern in human lymph nodes by immunohistochemical and immunoelectron microscopic techniques. The location of LFA-1-positive lymphocytes and selective expression of ICAM-1 on the luminal plasma membrane of high endothelial venule endothelium suggested that the LFA-1/ICAM-1 adhesion pathway participates only in the initial step of the lymphocyte migration process. Lymphocytes passing through endothelium appear not to be influenced by this pathway. VCAM-1 was detected occasionally on the endothelium of high endothelial venules in the hyperplastic lymph nodes in the mesentery, but not in peripheral lymph nodes. VLA4-positive lymphocytes tended to be more frequently observed within high endothelial venules in mesenteric lymph nodes than in peripheral ones. Strong expression of both ligands, ICAM-1 and VCAM-1, was noted on the plasma membrane of follicular dendritic cells, and was especially prominent on their labyrinthine folding, and on the interdigitating cells in the paracortex. Furthermore, both LFA-1- and VLA4-positive lymphocytes localized around these cells. This suggests that LFA-1/ICAM-1 and VLA4/VCAM-1 adhesion pathways play an important role in the lymphocyte recognition of antigen-presenting cells.

Cell Adhesion Molecules↗

PubMed1993

Improved in vitro angiogenesis model by collagen density reduction and the use of type III collagen.

Angiogenesis was examined by a three-dimensional model in vitro, using human umbilical vein endothelial cells (HUVECs) cultured in a collagen gel. An abundant capillary-like network with a lumen structure was identified histologically and shown to have formed at a collagen density of 0.05% or 0.10% instead of 0.15%, for either type I or type III collagen. At the same density, type III collagen induced a capillary-like network with HUVECs at an earlier stage of culture than type I collagen. In a two-dimensional culture, HUVECs were viable and proliferated to a great extent on the culture dish coated with collagen. This was particularly so in the case of type III collagen at lower density (5 ng/cm2). Type III collagen at a sufficiently low density is thus shown useful for studying angiogenesis in vitro. The capillary-like network that formed in the three-dimensional culture appeared somewhat labile, but became stable with the continuous addition of endothelial cell growth supplement and increase in the plating number of HUVECs.

Capillaries↗

PubMed1993

A cultured skin substitute composed of fibroblasts and keratinocytes with a collagen matrix: preliminary results of clinical trials.

The cultured skin substitute was created through successive cultivation of fibroblasts and keratinocytes that were combined within a collagen matrix. This collagen matrix was composed of a collagen spongy sheet and a collagen gel. The collagen spongy sheet was designed to produce a honeycomb structure having many holes in which all holes through the sheet were filled with collagen gel. This specific structure thereby allows for the nourishment of the cultured keratinocytes on the surface of the matrix when placed on the graft bed. In this study, autologous cultured skin substitute was applied to a 51-year-old man who had sustained a burn injury. Three sheets of the cultured skin substitute (6 x 9.5 cm) were grafted onto the full-thickness excised wound in the right anterior chest wall. One week after grafting most of the matrix disappeared and stratified keratinocytes were seen to have firmly attached to the underlying tissue. Five weeks after grafting a cornified epidermal layer was seen. Ten months after grafting a mature epidermis and a well-differentiated papillary and reticular dermis replacement were observed. The physical properties and color of this grafted area resemble those of normal skin. In the second test case, autologous cultured skin substitute was applied to a 30-year-old man with a scar remaining after tattoo removal. Eight sheets of the cultured skin substitute (10 x 18 cm) were applied on an excised wound (thickness, 0.02-0.025 in.) of both the fore- and upper arms. The histological appearance of a biopsied skin specimen from the grafted area at 3 months after grafting showed a mature epidermis and a well-differentiated reticular dermis replacement. The regenerated skin at 14 months after grafting showed an excellent result.

Adult↗

PubMed1992

A silver-sulfadiazine-impregnated synthetic wound dressing composed of poly-L-leucine spongy matrix: an evaluation of clinical cases.

The management of severe burns requires the suppression of bacterial growth, particularly when eschar and damaged tissue are present. For such cases, silver sulfadiazine (AgSD) cream has been traditionally applied. This antibacterial cream, however, cannot be used in conjunction with a temporary wound dressing that is needed to promote healing. The authors developed a synthetic wound dressing with drug delivery capability for clinical use by impregnating a poly-L-leucine spongy matrix with AgSD, which is released in a controlled, sustained fashion. In general, the dressing adhered firmly to the wound in the case of superficial second-degree burns, and during the healing process it separated spontaneously from the re-epithelialized surface. In the management of deep second-degree burns where eschar and damaged tissue were present, the dressing had to be changed at intervals of 3 to 5 days until it adhered firmly to the wound. Once the dressing had firmly attached to the wound, it was left in place until it separated spontaneously from the re-epithelialized surface. Dressing changes were fewer than with other treatments and the pain was effectively reduced. Cleansed wounds were effectively protected from bacterial contamination. Of 52 cases treated with this wound dressing, 93% (14/15) of superficial second-degree burns, 75% (3/4) of deep second-degree burns, 85% (6/7) of superficial and deep second-degree burns, and 75% (12/16) of split-thickness skin donor sites were evaluated as achieving good or excellent results.

Adult↗

PubMed1991

Formation of hair follicles from a single-cell suspension of embryonic rat skin by a two-step procedure in vitro.

A technique for culturing skin was devised whereby hair follicles in a normal state were generated from a single-cell suspension of embryonic rat skin. Dissociated cells obtained by trypsinization of the day-15 embryonic lip were cultured by a two-step procedure in vitro. Reorganization of hair-follicle rudiments was accompanied by reaggregation of the cells during a 24-hour initial culture with rotation, and the rudiments differentiated into hair follicles within a week during subsequent subculture of the cell aggregates by floatation. The light-microscopic features and the size of the follicles were similar to those of day-18 vibrissa follicles during normal development in vivo. Furthermore, the stratification of cells, including subcellular differentiation, and the ultrastructure of the hair follicles generated in vitro were similar to those of normal hair follicles with well-keratinized hair shafts. The present system appears to be a useful model for analytical studies in vitro on the formation of hair follicles and for studies designed to facilitate the transplantation of human hair.

Animals↗

PubMed1991

[Analysis of transmission of continuous adventitious lung sounds in asthmatic patients--a comparison with continuous sounds due to bronchial stenosis].

We studied the acoustic features of continuous adventitious lung sounds in asthmatic patients, and analyzed the characteristics of transmission by comparing the continuous sounds in asthmatic patients with those due to bronchial stenosis. The results were as follows. 1) Continuous adventitious lung sounds in patients with bronchial stenosis confirmed by bronchoscopy were well transmitted to the neck over the trachea. Therefore, it was demonstrated that continuous adventitious lung sounds generated in the lung are able to be transmitted to the tracheal region. 2) Continuous adventitious lung sounds in asthmatic patients were divided into monophonic tones and polyphonic tones, according to sound spectrographic findings. From the results of the coherence analysis, the monophonic tones were considered to be generated in the right or left lung, and were well transmitted to the neck over the trachea. The origin of the polyphonic tones was unknown, but they were also relatively well transmitted to the neck over the trachea. It was confirmed that the tracheal region is a very important location for auscultating and monitoring asthmatic patients.

Adult↗

PubMed1990

[Vestibular ataxia caused by meningeal carcinomatosis].

A 74-year-old man developed progressive deafness and unsteady gait two years after gastrectomy for a gastric cancer. Neurological examination revealed an alert and intelligent Japanese male in no acute distress. The optic fundi were normal. The pupils and the extraocular muscles were normal, however, horizontal nystagmus was noted in right and left gaze. He showed marked bilateral deafness, and loss of caloric response bilaterally. No muscle atrophy nor weakness was noted. His gait was wide-based and ataxic. Tandem gait was impossible. Romberg sign was present. No cerebellar ataxia was noted in the finger-to-nose or the heel-to-knee test. No adiadochokinesis was noted. Hyperextensibility was noted in the lower extremities. Deep reflexes were normal in the upper limbs, and diminished in the lower extremities. Sensation was intact. He showed the jumbling phenomenon, and the disturbance of the righting reflex in the tilt-table examination. Neuroradiological as well as laboratory studies were unremarkable except for the high titer of CEA in the CSF. Four months after his admission, malignant tumor cells were found in the CSF. It seemed likely that he had completely lost bilateral vestibular and auditory functions caused by meningeal carcinomatosis. His disturbance of gait and station was apparently similar to cerebellar ataxic gait, however, he did not have limb ataxia. The cranial CT scans failed to show cerebellar atrophy. It was our impression that his motor disturbance was in all likelihood caused by the bilateral loss of vestibular functions, i.e., vestibular ataxia.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1989

Correction of a chest wall deformity utilizing latissimus dorsi with a turnover procedure.

Infraclavicular hollowing and the abnormal anterior axillary fold are often seen in patients with Poland's syndrome and related conditions. The operative procedure described in this article corrects these deformities. The procedure uses the latissimus dorsi island flap. The inserted muscle is moved anteriorly and sutured between the deltoid and the biceps. Then the muscle flap is twisted between its origin and where it is inserted. The muscle fibers act like a pivot and the thickness of the flap is increased, which enables us to achieve a round anterior axillary fold. The muscle flap fills the infraclavicular region and softens the deep hollow area.

Adolescent↗