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Biomedical subjects

Y Kitano

Publications and source records attributed to Y Kitano.

At least 163 records · Page 9Linked to original sources
PubMed1991

Suppression of proliferation of human epidermal keratinocytes by 1,25-dihydroxyvitamin D3. Analysis of its effect on psoriatic lesion and of its mechanism using human keratinocytes in culture.

Psoriasis is a genetically determined chronic disease of the skin, and an accelerated proliferation of epidermal keratinocytes is one of the pathophysiological characteristics of psoriatic lesion. Recently, it was reported that topical administration of 1,25-dihydroxyvitamin D3 was effective for psoriasis. Our study was done to investigate the effect of 1,25-(OH)2-D3 on cell kinetics on human epidermal keratinocytes as a possible mechanism of its effect on psoriasis. After 24-h application of 1 microgram g-1 1,25-(OH)2-D3 ointment to psoriatic lesion, the number of mitotic keratinocytes decreased. When the cultured human keratinocytes were exposed to 10(-8) mol l-1 1,25-(OH)2-D3 for more than 9 days, inhibition of cell proliferation was noted. DNA distribution analysis by flow cytometry showed a decrease in cells in the S phase, and increase in 2c cells. This indicates blockade of the cell cycle in the G1 phase. The cell cycle time was not extended as a result of 1,25-(OH)2-D3-treatment.

Administration, Topical↗
PubMed1991

Clinical application of modified polyurethane graft to blood access.

Based on a study of 34 clinical implantations, a porous poly(ether-urethane) graft developed for blood access was evaluated. Although it became clear that the graft has several advantages over expanded polytetrafluoroethylene (E-PTFE), it was also revealed that the occlusion at the anastomotic site was more frequently observed than that with E-PTFE. To improve the patency rate, a small modification of the luminal surface was attempted to give a better anchoring of the neointima. The results so far are better than those with the unmodified graft. However, the number of cases is small and the period of observation is short. More work will be necessary to confirm these preliminary results.

Arteriovenous Shunt, Surgical↗
PubMed1990

Organization and disorganization of actin filaments in human epidermal keratinocytes: heat-shock treatment and recovery process.

We investigated alterations of actin organization due to heat shock and recovery from the collapse in human epidermal keratinocytes. Exposure of keratinocytes to elevated temperature caused the rapid disintegration of actin filaments. With a heat-shock treatment at 45 degrees C for 10 min, actin filaments disappeared and granular actin was distributed diffusely in the cytoplasm. After return to 37 degrees C, recovery of actin organization was observed. Completely disintegrated granular actin assembled to form actin dots, which tended to group. The grouping actin dots often took a circular, semicircular or arched form. Filamentous actin then extended out from the actin dots. Fine short bundles of actin filaments had a rippled appearance or were polygonal in structure, with actin filaments converged at many points. On the seventh day after heat-shock treatment, actin organization had almost returned to the pre-heat-shock condition, with diffusely distributed actin filaments. In previous studies, we observed such aberrant structures in human malignant keratinocytes and human epidermal keratinocytes treated with 12-O-tetradecanoylphorbol-13-acetate. The observations presented here indicate that those structures are not specific to malignancy or to the process of malignant transformation, but represent less mature and aberrant organizations of actin.

Actin Cytoskeleton↗
PubMed1990

Electron microscopic study of cultured cells from the murine hair tissues: cell growth and differentiation.

The cultured hair cells from 4-day-old C3H mice were studied by electron microscopy. The hair roots isolated from the skin by collagenase digestion were dispersed into a cell suspension by treatment with a mixture of trypsin and ethylenediaminetetraacetate. The cells were cultured in MCDB-153 (a medium containing seven growth factors) for 1, 3, 6 or 13 days. The number of cultured cells on day 3 was twice that on day 1, and stayed at the same level until day 13. By electron microscopy, some of the cells cultured for 1 day were seen to be undifferentiated and others already showed differentiation into various hair structures. Such differentiated cells disappeared on day 3 and most of the cells cultured for 3 days were undifferentiated. Cell cultured for 6 days were differentiated showing inner root sheath cell, hair cortical cell and medulla cell structures. The characteristics of these cultured cells corresponded well to those of in vivo cells of the hair tissues from the back skin of 7-day-old C3H mice. On day 13 degeneration occurred in the cultured cells. In none of these cultures were mesenchymal cells, such as fibroblasts, found. The present electron microscopic study reveals that immature cells obtained from mouse hair tissues proliferate in vitro and differentiate into several subpopulations corresponding to those of in vivo cell layers of hair tissues. The present culture technique may be useful for studies of hair cell growth and differentiation.

Animals↗
PubMed1990

Ciclosporin treatment in children with steroid-dependent nephrotic syndrome.

We report our experience with ciclosporin (CS) treatment in 18 children with steroid-dependent nephrotic syndrome. CS was started at 3-5 mg/kg per day after the patients had attained remission with steroid therapy, and was adjusted to maintain a trough blood level of between 250 and 600 ng/ml, being administered for 6 months. Although 1 patient dropped out of the study because of renal dysfunction, the remaining 17 children completed the full trial. No relapse occurred during the 6-month period of CS treatment, and it was possible to discontinue steroid therapy in all patients. However, after discontinuation of CS treatment, nephrotic syndrome relapsed in 16 patients and 14 again had frequent relapses and became steroid-dependent, as before CS treatment. The effect of CS in maintaining remission from steroid-dependent nephrotic syndrome was thus dependent on continuation of CS treatment. Although several side-effects occurred during CS treatment, they were not so serious as to necessitate discontinuation of treatment, except in 1 patient, and all of these side effects were reversible. CS is therefore a new agent for the management of children with steroid-dependent nephrotic syndrome in place of corticosteroid and alkylating agents, although long-term maintenance therapy may be necessary for maintaining longer remission.

Adolescent↗
PubMed1990

Growth of human keratinocytes in a defined medium supplemented with growth factor of serum.

In order to prepare a good medium for cultivation of keratinocytes, bovine serum was fractionated by precipitation with various concentrations of ammonium sulfate. The fractionated serum proteins were added to the basal medium at a concentration of 3 mg/ml. The best proliferation was observed in the medium supplemented with the 55-70% ammonium sulfate precipitated fraction. No growth of keratinocytes was observed when the medium was supplemented with the 0-35% fraction. The growth promotion by the 55-70% fraction was completely inhibited by the 0-35% fraction. These results have shown that the fractionation of serum protein clearly separated the growth-inhibitory factors and the growth-stimulating factors.

Blood Proteins↗
PubMed1990

Immunoregulatory activity in human decidua.

The immunoregulatory factor(s) that suppresses normal human peripheral blood mononuclear cells (PBM) function was extracted from the decidua of pregnant women (8-13 weeks). Compared with extracts from the proliferative endometrium, the decidual extracts from fresh surgical specimens markedly inhibited 3H-thymidine incorporation by PBM in response to T-cell mitogens. The majority of the lymphocyte-inhibitory activity was found to be associated with a material of large molecular weight in the decidua, as estimated by Sephadex G-200 filtration. Immunoelectrophoretic analysis followed by Sepharose 4B-anti-human IgG affinity chromatography of the fraction having the inhibitory activity revealed the causative factor to be most likely IgG or a substance copurified with IgG. The results are discussed with respect to a possible role of IgG in a localized non-specific suppressor mechanism in the decidua preventing maternal immunologic attack on the fetal allograft.

Adult↗
PubMed1990

[Measurement of the charge on red blood cells in patients with various glomerulopathies].

Red blood cells have a negative charge on their surface which prevents Rouloau formation. This charge may reflect the charge on glomerular capillaries. Using alcian blue, we measured the negative charge on red blood cells in patients with IgA nephropathy (IgAN), membranous nephropathy (MN), minimal change nephropathy (MCN) and focal glomerular sclerosis (FGS), for which the diagnosis was determined by renal biopsy. The alcian blue values for the normal control, IgAN, MCN (nephrotic phase), MCN (remission) and MN were 155.3 +/- 12.3, 140.9 +/- 23.9, 101.7 +/- 18.4, 152.9 +/- 11.2 and 140.9 +/- 23.6 ng per 1 x 10(6) red blood cells, respectively. The charge was more significantly decreased in MCN during nephrotic phase than other renal diseases and the normal control. The charge in MCN was within the normal range on remission. When we studied the correlation between the charge on red blood cells and proteinuria during steroid therapy, the charge in MCN was found to increase with reduction of proteinuria, while there was no change in MN and FGS with reduction of proteinuria, i.e. it was usually within normal range. The reduced charge was associated with the nephrotic phase in MCN. The difference in the charge on the red blood cells between MCN and FGS during nephrotic phase seems to suggest a different etiology of proteinuria. Measurement of the charge on red blood cells could be an useful method for differentiating MCN from other renal diseases in the nephrotic phase.

Adolescent↗
PubMed1989

Synthesis of epidermolysis bullosa acquisita antigen by simian virus 40-transformed human keratinocytes.

The synthesis of epidermolysis bullosa acquisita (EBA) antigen in simian virus 40 (SV40)-transformed human epidermal keratinocytes was studied. Indirect immunofluorescent staining of SV40-transformed keratinocytes employing a serum sample from an EBA patient as a source of antibodies decorated EBA antigen as a perinuclear granular fluorescence. This staining pattern was similar to that of nontransformed epidermal keratinocytes grown in a low Ca2+ medium. In contrast, stratified primary cultures of keratinocytes stained after growth in a high Ca2+ medium showed only small amounts of the antigen localized in the substrate-attached basal cells. To demonstrate biosynthesis of the EBA antigen by SV40-transformed keratinocytes, cells were metabolically labeled with 14C-amino acids and the cell lysates were immunoprecipitated with EBA antiserum. Analysis of immunoprecipitates by sodium dodecylsulfate-polyacrylamide gel electrophoresis and fluorography revealed that the EBA serum precipitated a protein with an apparent molecular weight of 290 kD from extracts of these cells. These results indicate that SV40 induces the synthesis of the 290 kD EBA antigen. Expression of this antigen may be a general feature of nonstratifying, proliferating epidermal cells.

Amino Acids↗
PubMed1989

Cutis laxa with ultrastructural abnormalities of elastic fiber.

A case of a congenital, autosomal recessive form of generalized cutis laxa is reported. The patient was a 27-month-old boy with generalized flaccid skin and short stature. Radiologic examination revealed that the age of the bones of the wrist was compatible with a chronologic age of only 1 year. Elastic fibers were diminished throughout the dermis, and results of electron microscopic study showed globular and unstained elastin and relatively large amounts of the microfibrillar components of elastic fibers.

Biopsy↗
PubMed1989

Expression of proliferating cell nuclear antigen/cyclin in human keratinocytes.

The expression of proliferating cell nuclear antigen (PCNA), also called cyclin, in human keratinocytes was examined by using the serum obtained from a SLE patient and a murine monoclonal antibody against PCNA/cyclin. In the normal epidermis, few of the nuclei were labeled with anti-PCNA/cyclin. This was in contrast to the positive nuclear staining seen in active lesions of psoriasis. In a primary culture of human keratinocytes growing as a monolayer, 20%-30% of cells expressed PCNA/cyclin. SV40-transformed human keratinocytes showed positive nuclear staining in about 40% of the cell population. In stratified keratinocytes cultured in a high Ca++ medium, PCNA/cyclin expression was decreased and only the cells in the basal and suprabasal layers showed positive staining. These results indicate that the expression of PCNA/cyclin correlates with the proliferating state in human keratinocytes and may not be associated with the mechanism of differentiation in keratinocytes.

Antibodies, Monoclonal↗
PubMed1989

Skin pigmentation associated with minocycline therapy.

A patient on long-term minocycline therapy developed blue-black discoloration on the legs. Skin biopsy specimens from the pigmented areas were examined by light and electron microscopy and energy-dispersive X-ray microanalysis. Pigmented granules were present at all levels of the dermis and subcutaneous fat tissues. Ultrastructural examination showed electron-dense granular material within the cytoplasm of dermal macrophages and energy-dispersive X-ray microanalysis indicated that the granules contained iron. Thyroid tissue obtained by aspiration biopsy showed the presence of fine brown granules within the cytoplasm of the follicular epithelial cells. An extract of skin from the pigmented areas was subjected to high performance liquid chromatography and minocycline was detected.

Female↗
PubMed1989

Types of human papillomavirus isolated from Japanese patients with epidermodysplasia verruciformis.

Virological studies were performed on 12 patients with epidermodysplasia verruciformis (EV). Three types of lesions were observed: red plaques, pityriasis versicolor (PV)-like macules and plane warts. Human papillomavirus (HPV) 14, 20 and 21 were isolated from the plaques, HPV 3, 14 and 38 from flat warts and HPV 5, 12, 17, 20 and 38 from PV-like lesions. No clear relationship could be established between the different lesions and the types of HPV. Types 17 and 20 have been isolated most frequently from Japanese EV patients and HPV 5, frequently detected in other countries, is less common, whereas HPV 8 has not been isolated. Skin cancers occurred in six of the cases (50%) and all had benign lesions that were PV-like. At least one type of HPV 5, 17 or 20 could be isolated from these benign lesions and HPV 17 or 20 detected in the cancers. These three types of HPV in EV patients appear to be involved in the malignant transformation.

Adult↗
PubMed1989

[Clinical evaluation of the prehospital phase of acute myocardial infarction in the elderly].

In order to clarify the clinical characteristics of the prehospital phase of acute myocardial infarction (AMI) in the elderly, we studied 92 elderly (65 years old or more) and 41 younger patients with first AMI. Fifty eight elderly (63.1%) and 30 younger (72.7%) patients had typical symptoms such as chest pain at onset. There were 5 elderly cases who had no symptom, although all of the younger had some symptoms at onset. More than 70% of the younger cases developed their symptoms either between 6 am and noon or between 6 pm and midnight, whereas the elderly showed no such tendency. Intervals between the onset of symptoms and hospital admission (admission time) averaged 6.8 hours (hr) in the younger and 7.7 hr in the elderly. Approximately one half of the elderly and a quarter of the younger showed admission time more than 6 hr, respectively. Elderly cases with atypical symptoms tended to have a longer admission time than younger cases (7.2 vs 3.1 hr), although there was no significant difference between the elderly and the younger with typical symptoms (8.0 vs 7.9 hr). Younger patients with heart failure had significantly shorter admission time than those without heart failure (3.6 vs 8.6 hr). However, the elderly with heart failure showed a prolonged admission time (6.1 hr). Although there was no difference on admission time between survivors and non-survivors within 28 days after admission in the elderly (7.5 vs 8.4 hr), the elderly non-survivors with atypical symptoms had the longest admission time (13.0 hr).(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1989

[A case of dumb-bell-like neurilemmoma of the posterior mediastinum].

A 56 year-old female was pointed out an abnormal shadow on chest X-ray film for the lung cancer screening study. Chest X-ray film showed a round mass shadow at the right superior mediastinum. Chest CT scan revealed the mass was in the paravertebral area abutting on the 2nd thoracic vertebral body and had extended into the intervertebral foramen. Preoperative diagnosis was a dumb-bell-like neurogenic tumor. Operation was carried out by posterior approach in the prone position. At first thoracotomy was done by removing the paravertebral portion of the 2nd and 3rd ribs, and then hemilaminectomy was added. Both the intrathoracic and intraforminal portions of the tumor were completely exposed, and excised. Pathological examination demonstrated the tumor was a typical neurilemmoma originating from the 2nd intercostal nerve. When a neurogenic tumor of the posterior mediastinum has an intraspinal extension, a posterior approach by a simultaneous thoracotomy and laminectomy will be useful to remove the tumor at one sitting.

Female↗
PubMed1989

[Methods for optimized cultivation of hair cells from C3H mice].

Methods for the optimized culturing the hair cells from 4-day-old C3H mice are described. The skin was obtained and soaked in 500 unit/ml dispase at 4 degrees C for 24 hr. Then the epidermis was removed and the dermis was further treated with 0.25% collagenase for 1 hr at 37 degrees C. The hair roots isolated by collagenase digestion of the dermis were dispersed by the treatment with the mixture of trypsin and EDTA into a cell suspension and plated on a substrate. Attachment of hair cells was dependent on serum concentrations and enhanced by collagen coating of the surface of dishes. MCDB 153 was beneficial for the growth of hair cells and discouraged for the growth of dermal fibroblasts. The cells could not grow at inoculum size of less than 3 x 10(4) cells/cm2. Addition of a crude bovine pituitary extract in MCDB 153 had the greatest impact on hair cell growth. Functional integrity of the cultured hair cells were maintained, since the hair-specific cytoskeletal proteins were expressed in these cells under the present experimental conditions. These desirable conditions could allow selective growth of the hair cells and provide the model system which could be used for the study of hair growth.

Animals↗
PubMed1989

Microscopic observation of leukocyte kinesis in the vascular bed during hemodialysis using the rabbit ear chamber technique.

Leukocyte kinesis in the capillary vascular bed during hemodialysis (HD) was investigated to elucidate the mechanism of transient leukopenia. Leukocyte movement was observed microscopically during HD using the rabbit ear chamber (REC) technique, which permits visualization of the movement of blood corpuscles in capillaries. Blood was drawn from the femoral artery and returned into the auricular and/or carotid artery so that the blood passing through the hollow fiber artificial kidney (HFAK) flowed into capillaries in the REC. Leukocyte counts of blood samples taken from the afferent and efferent limbs of the HD circuit, the right jugular vein and the right atrium were determined consecutively during HD. The difference in the leukocyte count was observed between the afferent and efferent limbs for the first 15 minutes and thereafter between the efferent limb and the jugular vein. The "transpulmonary" difference in the leukocyte count was not noticed throughout HD. Between 15 and 90 minutes after the start of HD, scarcely any circulating leukocytes were found in capillaries in the REC and some leukocytes were attached to the endothelial surface. Thereafter circulating leukocytes were seen again and detachment of leukocytes from the endothelial surface was observed. No leukocyte aggregation or embolization of aggregating leukocytes was noticed. This evidence suggests that leukopenia may be attributed to the transient shift of leukocytes to the marginal pool of the vessel lumen and this process may not be specific for the pulmonary vasculature, but may occur in the first capillary bed into which the blood passing through the HFAK flows.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗