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Biomedical subjects

Y Kitano

Publications and source records attributed to Y Kitano.

At least 145 records · Page 8Linked to original sources
PubMed1992

Effects of several growth factors on cultured neurofibroma cells.

Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder characterized by abnormalities affecting multiple tissues derived from the neural crest. The peripheral neurofibromas are numerous and sometimes reach several hundred in number. In this study, the possible involvement of several growth factors in neurofibroma growth was investigated in vitro. When explants of neurofibroma tissue were cultured, macrophage-like cells with pseudopodia migrated out first, and later took on a slender fusiform shape. These cells contained S-100 protein and were identified as Schwann cells. They did not proliferate under standard culture conditions. Nerve growth factor (NGF) was helpful in maintaining the differentiated phenotype of Schwann cells, but did not stimulate their proliferation. Immunohistochemical staining for type IV collagen revealed that some large flattened polygonal cells had a mesh of type IV collagen on the surface. These cells were perineurial cells. The proliferation of cells derived from neurofibroma was stimulated by basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), and transforming growth factor alpha (TGF-alpha). In comparison with skin fibroblasts, the cells derived from neurofibroma responded to these growth factors at considerably lower concentrations. Stimulation by EGF at physiological concentrations indicated the possible involvement of EGF in the development of neurofibromas.

Cell Division↗
PubMed1992

Congenital alveolar adhesions.

We report an infant girl with congenital alveolar adhesions and a cleft palate. The mucosal bands were resected the day after birth. Stretching exercises of the mandible improved the range of movement at the temporomandibular joint. Two weeks of therapy were required before full mouth opening was possible. Previously reported patients and theories of embryogenesis are reviewed.

Alveolar Process↗
PubMed1992

In vitro keratin expression of hair cells.

Human hair follicles were isolated from the scalp by dispase and collagenase treatment and dispersed into a cell suspension by trypsin. These cells proliferated well and could be subcultured 7 to 8 times. The medium used was MCDB 153 HAA medium further supplemented with some amino acids, hydrocortisone, insulin, EGF, and bovine brain extract. The concentration of Ca++ was adjusted to 0.1 mM. Immunohistochemically, these cells were proved to possess keratins specific to hair forming cells.

Culture Techniques↗
PubMed1992

Aberrant cytokine production from tenosynovium in dialysis associated amyloidosis.

Culture supernatants of tenosynovial tissues from patients with carpal tunnel syndrome undergoing chronic haemodialysis contained interleukin (IL) 1-like and IL6-like activity. These culture supernatants also induced active proliferation of rheumatoid synovial cells. Immunohistochemical analysis of teno-synovial tissues showed the accumulation of mononuclear cells bearing CD14 and HLA-DR antigens adjacent to the deposition of amyloid protein (beta 2 microglobulin). These cells also reacted with antibodies to IL1 and IL6 respectively. These data suggest that multiple cytokines, including IL1 and IL6, produced from tenosynovial tissues in patients with dialysis associated amyloidosis might induce the proliferation of synovial cells that, together with deposition of amyloid protein, might cause carpal tunnel syndrome.

Aged↗
PubMed1992

Synthesis, structure and antitumor activity of a water-soluble platinum complex, (1R,3R,4R,5R)-(-)-quinato(1R,2R-cyclohexanediamine)platinum (II).

The reaction of dihydroxo(1R,2R-cyclohexanediamine)platinum(II) with (-)-quinic acid gave a water soluble complex, (-)-quinato(1R,2R-cyclohexanediamine)platinum(II). The crystal structure of the complex was determined by X-ray analysis. The data indicate a chelation of the alpha-hydroxycarboxylic acid part of quinic acid to platinum(II). The complex shows moderate antitumor activity against murine leukemia L1210 at high doses (T/C x 100 = 179% at a dose of 200 mg/kg).

Animals↗
PubMed1992

Allergic granulomatosis and angiitis of Churg-Strauss. A case of high serum level of eosinophil cationic protein.

We report a case of allergic granulomatosis and angiitis of Churg-Strauss. The patient is a 40-year-old woman who satisfied the clinico-pathological triad of asthma, tissue and blood eosinophilia, and granulomatous vasculitis. We also measured serum eosinophil cationic protein (ECP) levels in this patient. In the active stage, the serum ECP level was higher than in healthy controls, declining in the remission stage, a finding suggesting that ECP is involved in the pathogenesis and course of Churg-Strauss disease.

Adult↗
PubMed1992

[Hemodynamic management of LOS using prolonged VA bypass circulatory assist].

The authors managed five LOS patients using prolonged V-A bypass circulatory assist. Maximum CVP values were under 12 mmHg in three survivors, and 17 mmHg and 20 mmHg in two nonsurvivors. Maximum PCWP values were under 14 mmHg in survivors, and 19 mmHg and 20 mmHg in nonsurvivors. Dopamine was administrated in all cases and norepinephrine was administrated at a rate of less than 0.3 microgram.kg-1.min-1 in survivors, and in two nonsurvivors, norepinephrine was used at a rate of 0.36 and 1.2 micrograms.kg-1.min-1. Before and after disconnection of V-A bypass, the bypass flow of the three survivors were under 1.0 l.min-1 just before disconnection, and immediately after it, the preload did not increase, and the dose of administrated catecholamine increased. V-A bypass time intervals of the three survivors were 71, 42 and 87 hours, and those of the two nonsurvivors were 71 and 43 hours. Maximum bypass flow rate was above 40ml.kg-1.min-1 in four of five patients. The authors discussed the management of the patients' heart and of the V-A bypass machine during the prolonged V-A bypass circulatory assist.

Aged↗
PubMed1992

[Two cases of renal oncocytoma].

Two cases of renal oncocytoma are reviewed. A 67-year-old man and a 21-year-old man with a right renal mass were incidentally revealed by echography. Selective renal angiogram showed no spoke-wheel configuration of vessels in either case. Both cases were pathologically diagnosed as oncocytomas, constructed of large eosinophilic cells with granular cytoplasm and small regular nuclei. The electron micrograph showed cytoplasm packed abundantly with mitochondria. The two patients are in good condition 2.5 and 1.5 years after diagnosis.

Adenoma↗
PubMed1992

[Differentiation therapy of acute promyelocytic leukemia: two successful cases of remission induction by all-trans retinoic acid].

We described two pediatric patients with acute promyelocytic leukemia (APL) who were successfully induced into complete remission with all-trans retinoic acid (ATRA, 45 mg/m2 per day) after failing on conventional chemotherapy. Initial response was observed as correction of DIC within a week of treatment. Hematologically, initial increase of maturing leukocytes reached a peak peripheral WBC count on the 16th and 20th day, respectively. However, these seemingly differentiated leukocytes retained Auer body and dysplastic features and there was no concomitant recovery of erythroid and megakaryocytic lineages at this point. A sudden drop of leukocyte counts after this peak made a brief period of leukopenia before the complete remission was finally attained morphologically in 4-5 weeks. Thus, remission of APL by ATRA therapy consisted of a two-phase course. In one patient, we observed an increase of histiocytes phagocytizing leukocytes in the marrow during the recovery from leukopenia. It is, therefore, postulated that the two-phase course of recovery may reflect the differentiation of leukemic cells by ATRA and subsequent clearance of senescent cells by the reticuloendothelial system followed by regeneration and differentiation of residual normal hematopoietic stem cells.

Adolescent↗
PubMed1991

The relationship between juxtapapillary duodenal diverticula and the presence of bacteria in the bile.

A total of 432 patients with gallstone disease were studied with respect to the existence of juxtapapillary duodenal diverticula and their relationship to the presence of bacteria in the bile. A total of 63 patients were found to have diverticula with an incidence of 14.6 per cent, being significantly higher in the elderly group aged 60 years or older (p less than 0.01), and no sex difference was noted. Among the patients with diverticula, positive bacterial cultures of bile were recognized at a significantly higher frequency, being found in 49 of the 63 patients (77.8 per cent; p less than 0.01), and the probability of bilirubinate stones was also higher, being found in 35 of 37 patients (94.6 per cent; p less than 0.01). The presence of a diverticulum bore significant relation to a higher positive bile bacterial culture (p less than 0.05), dilation of the common bile duct (p less than 0.05), and elevation of the bile duct pressure (p less than 0.05), even when the conditions were divided into cholecystolithiasis or choledocholithiasis. It was suggested that the presence of a diverticulum affected the flow in the bile duct by narrowing it from the outside and chronically stimulating the papilla, inducing biliary tract infection and/or the formation of gallstones. As the surgical procedures for juxtapapillary duodenal diverticula, including its indications, have not been established, long term follow up investigations seem necessary.

Adult↗
PubMed1991

Binder's syndrome: peculiarities in Japanese patients.

We have seen 4 Japanese patients with Binder's syndrome or maxillonasal dysostosis. The diagnosis of Binder's syndrome was very difficult, based on facial appearances alone. Although the flattened nasal tip was quite unusual in Japanese individuals, the midface retrusion and flattened nasal bridge would be considered within normal limits. Consequently, the diagnosis of Binder's syndrome is only rarely made in Japanese persons. The peculiarities of this syndrome in Japanese patients are discussed and our surgical methods are shown.

Adolescent↗
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↗