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Biomedical subjects

Y Mitsuhashi

Publications and source records attributed to Y Mitsuhashi.

At least 19 recordsLinked to original sources
PubMed2000

Oncogenes and tumor angiogenesis: differential modes of vascular endothelial growth factor up-regulation in ras-transformed epithelial cells and fibroblasts.

A possible link between oncogenes and tumor angiogenesis has been implicated by the finding that expression of various oncogenes, particularly mutant ras, can lead to a marked induction of a potent paracrine stimulator of angiogenesis, vascular endothelial growth factor (VEGF). We sought to determine how oncogenic ras induction of VEGF is mediated at the molecular level and whether the mechanisms involved differ fundamentally between transformed epithelial cells and fibroblasts. Our results suggest that in a subline (called RAS-3) of immortalized nontumorigenic rat intestinal epithelial cells (IEC-18) that acquired a tumorigenic phenotype upon transfection of mutant ras, up-regulation of VEGF occurs in the absence of an autocrine growth factor circuit. The expression of VEGF mRNA and protein by RAS-3 cells was strongly suppressed in the presence of LY294002, an inhibitor of phosphatidylinositol 3'-kinase, but remained largely unaffected in the same cells treated with an inhibitor (PD98059) of mitogen-activated protein/extracellular signal-regulated kinase kinase 1 (MKK/MEK-1). This is consistent with the observation that overexpression of a constitutively activated mutant of MEK-1 (AN3/ S222D) in the parental IEC-18 cells did not result in up-regulation of VEGF production. The impact of mutant ras on VEGF expression was also significantly amplified at high cell density, conditions under which RAS-3 cells became less sensitive to LY294002-induced VEGF down-regulation. In marked contrast to cells of epithelial origin, ras-transformed murine fibroblasts (3T3RAS) up-regulated VEGF in a manner that was strongly inhibitable by MEK-1 blockade (ie. treatment with PD98059), whereas these cells were relatively unaffected by treatment with the phosphatidylinositol 3'-kinase inhibitor LY294002. In addition, VEGF was up-regulated by 2-3-fold in NIH3T3 cells overexpressing mutant MEK-1. Collectively, the data suggest that the stimulatory effect of mutant ras on VEGF expression is executed in a nonautocrine and cell type-dependent manner and that it can be significantly exacerbated by physiological/ environmental influences such as high cell density.

3T3 Cells↗
PubMed2000

Comparative inhibitory effects of vitamin D3 and an analogue on normal and psoriatic epidermis in organ culture.

Recently, there have been many vitamin D3 analogues synthesized and tried in the treatment of psoriasis. In the experiments reported here we observed and compared their effects on normal and psoriatic epidermis in organ culture in vitro. We employed a new vitamin D3 analogue, 22-oxa-calcitriol (OCT), the effect of which was compared with that of calcitriol (1,25-D3). Both caused suppression of proliferation of normal and psoriatic epidermis, dependent upon concentration and culture time. Histologically, in the presence of the agents, degeneration started from the top of the epidermis downwards. This is the first report of cell degeneration as a direct effect of vitamin D. The nature of the degeneration was evaluated by electron microscopy (EM) and by the in situ nick end labeling technique (TUNEL), and these studies revealed that the degeneration involved necrosis rather than apoptosis. This in vitro method may be useful to assess the effectiveness of newly synthesized vitamin D3 analogues in the treatment of psoriasis.

Apoptosis↗
PubMed2000

beta(2)-adrenergic agonists and pelvic floor exercises for female stress incontinence.

OBJECTIVE: We compared beta(2)-adrenergic agonist therapy with clenbuterol (DT) and physiological therapy (PT) in a randomized study to establish the first line therapy for stress incontinence (SI). METHOD: The clinical efficacy of DT (group A), PT (group B), and a combination of DT and PT (group C) was investigated in 61 patients with SI by means of a 12-week randomized controlled study. The frequency and volume of SI and the patients' own impressions were used as the basis for the assessment of efficacy. RESULTS: The SI improvement rates in groups A, B, and C were 76.9, 52.6, and 89. 5%, respectively (P=0.0361). A significant therapeutic effect on the frequency of SI was observed in group B and group C at 2 weeks after the start of treatment (both P<0.05), and in all groups at 6 weeks (all P<0.01). The efficacy rates based on the patients' own impressions in groups A, B, and C were 84.6, 31.6, and 68.4%, respectively (P=0.0064). CONCLUSION: The beta(2)-adrenergic agonist appeared to be clinically useful as a drug of choice for SI.

Adrenergic beta-Agonists↗
PubMed2000

C2-ceramide induces apoptosis in a human squamous cell carcinoma cell line.

BACKGROUND: Previous studies have demonstrated that synthetic cell-permeable analogues of ceramide promote differentiation and inhibit proliferation of keratinocytes, and that the vitamin D3 inducible sphingomyelin cycle generates ceramide in keratinocytes. Although it has been suggested that exogenous ceramide induces apoptosis of keratinocytes, which is similar to their effect on other cell types, such as leukaemia cells, only a few studies have reported ceramide-induced apoptosis of keratinocytes. OBJECTIVE: To determine whether ceramide induces apoptosis of keratinocytes, we used the synthetic ceramide analogue, C2-ceramide (N-acetylsphingosine) and a human squamous cell carcinoma cell line, HSC-I. METHODS: We treated HSC-I cells with C2-ceramide, followed by a viability assay, morphological observations, nick end-labelling (TUNEL), DNA electrophoresis, and electron microscopy. RESULTS: In the viability assay, C2-ceramide was toxic to HSC-I cells in a dose-dependent manner. Manifestations of apoptotic morphology occurred in the ceramide-treated cells, whereas these morphological changes did not occur in cells treated with dihydroceramide (N-acetylsphinganine). TUNEL revealed that many of the ceramide-treated cells showed positive reactivity. DNA electrophoresis demonstrated that C2-ceramide caused internucleosomal fragmentation in a dose- and time-dependent manner. Electron microscopy revealed that the ceramide-treated cells manifested morphological characteristics typical of apoptosis. CONCLUSIONS: The present results demonstrate that C2-ceramide induces apoptosis of transformed human keratinocytes, whereas C2-dihydroceramide does not have such an effect. The fact that ceramide induces apoptosis of keratinocyctes raises the possibility that intracellular ceramide, which is increased with differentiation of the epidermis, might be involved in terminal differentiation, a specialized form of apoptosis of keratinocytes.

Apoptosis↗
PubMed2000

Localization of the Netherton syndrome gene to chromosome 5q32, by linkage analysis and homozygosity mapping.

Netherton syndrome (NS [MIM 256500]) is a rare and severe autosomal recessive disorder characterized by congenital ichthyosis, a specific hair-shaft defect (trichorrhexis invaginata), and atopic manifestations. Infants with this syndrome often fail to thrive; life-threatening complications result in high postnatal mortality. We report the assignment of the NS gene to chromosome 5q32, by linkage analysis and homozygosity mapping in 20 families affected with NS. Significant evidence for linkage (maximum multipoint LOD score 10.11) between markers D5S2017 and D5S413 was obtained, with no evidence for locus heterogeneity. Analysis of critical recombinants mapped the NS locus between markers D5S463 and D5S2013, within an <3.5-cM genetic interval. The NS locus is telomeric to the cytokine gene cluster in 5q31. The five known genes encoding casein kinase Ialpha, the alpha subunit of retinal rod cGMP phosphodiesterase, the regulator of mitotic-spindle assembly, adrenergic receptor beta2, and the diastrophic dysplasia sulfate-transporter gene, as well as the 38 expressed-sequence tags mapped within the critical region, are not obvious candidates. Our study is the first step toward the positional cloning of the NS gene. This finding promises a better understanding of the molecular mechanisms that control epidermal differentiation and immunity.

Adolescent↗
PubMed2000

E-cadherin expression in skin tumors using an AMeX immunohistostaining method.

The AMeX (acetone-methylbenzoate-xylene) method results in good preservation of tissue and morphological details, almost equivalent to that of routinely processed formalin-fixed and paraffin-embedded tissue specimens, and of antigenicity equivalent to that of fresh frozen tissue specimens. It has been reported that the expression of the cell-cell adhesion molecule E-cadherin is often decreased in some types of carcinomas. A decrease in E-cadherin expression is associated with the invasive or metastatic potential of tumor cells. We immunohistochemically examined the expression of E-cadherin with anti-E-cadherin monoclonal antibody in various skin tumors (25 basal cell carcinomas, 11 squamous cell carcinomas, 9 keratoacanthomas, and 11 Bowen's disease) using the AMeX method and found that this method preserved antigenicity well without pretreatment. E-cadherin expression was decreased in 18.2% of squamous cell carcinomas and 33.3% of keratoacanthomas. On the other hand, it was preserved in almost all Bowen's disease and basal cell carcinomas. From the results of our study, we suggest that Bowen's disease and basal cell carcinoma do not have much metastatic potential due to retention of high levels of E-cadherin expression. We hope to apply the AMeX method to other immunohistochemical examinations because this is a very useful staining method.

Acetone↗
PubMed2000

A case of subcorneal pustular dermatosis treated with tacalcitol (1alpha,24-dihydroxyvitamin D3).

We report a case of subcorneal pustular dermatosis (SPD) treated with tacalcitol (1alpha,24-Dihydroxyvitamin D3) ointment. A 77-year-old male had had asymptomatic, superficial, grouped pustules in annular patterns with mild background erythema for six years which affected his axillae and bilateral groin. A diagnosis of SPD was made. Topical vitamin D3 (tacalcitol) was applied to the lesion of SPD and its clinical effectiveness was assessed. Within one month, symptoms in the lesion treated with tacalcitol ointment started subsiding, and eventually only erythema remained. After three months, the region treated with tacalcitol ointment showed no relapse. We conclude that tacalcitol ointment is effective for SPD in some case.

Administration, Cutaneous↗
PubMed2000

Squamous cell carcinoma arising in chronic perianal pyoderma a case report and review of Japanese literature.

We report a rare case of squamous cell carcinoma developing from fistules of chronic perianal pyoderma in a 49-year-old Japanese man. He first noticed an abscess and nodule on his buttocks and perianal area 21 year previously (at the age of 28); the fistules formed later. These fistules were surgically removed, and an artificial anus was constructed 14 years ago (at the age of 35) in our hospital, when a histopathological examination revealed no malignant changes. However, he was recently admitted to our hospital with arterial bleeding from the ulcer of the buttock. On admission, the histological diagnosis of the ulcer was well differentiated squamous cell carcinoma. Wide local excision of the ulcer and scar tissue, including the sacrum, was performed. The defect was covered with a left latissimus dorsi flap and skin graft. He received radiation therapy after the operation. However, he died of cachexia and pneumonia. This case indicated that the CPP would better have been treated with wide excision before the development of SCC. Therefore, we recommend careful follow-up of patients affected by CPP and repeated biopsies of the lesion, particularly when the condition is severe, longstanding, and extensive. We discussed the term "CPP" and reviewed 22 cases of SCC arising in CPP reported in the Japanese literature.

Anus Neoplasms↗
PubMed2000

Intracranial hypotension due to cerebrospinal fluid leakage detected by radioisotope cisternography.

Seven patients, six females and one male aged 26 to 39 years old, presented with headache in the upright posture, which was completely relieved in the recumbent posture. Radioisotope cisternography with technetium-99m-human serum albumin detected cerebrospinal fluid (CSF) leakage at the cervicothoracic level in six patients, and at the high cervical level in one patient. The diagnosis was intracranial hypotension due to spontaneous CSF leakage. Complete bed rest for more than 2 weeks resulted in complete resolution of the headache in all patients, and follow-up cisternography showed no leakage. Radioisotope cisternography is useful for the diagnosis of spontaneous CSF leakage, and complete bed rest for more than 2 weeks may be the best method of treatment.

Adult↗
PubMed2000

Effect of lactoferrin on lipopolysaccharide (LPS) induced preterm delivery in mice.

BACKGROUND: The present study attempted to confirm the preventive effect of lactoferrin on lipopolysaccharide (LPS) induced preterm delivery in mice. METHODS: Female C3H/HeNCrj mice were pair-mated with male Crj: B6D2F1 mice. On day 15 of gestation, a 50 micron/kg intraperitoneal injection of LPS (LPS group) was administered twice with a 3-hour interval between injections (at 2:00 and 5:00 PM). The mice were also given an intraperitoneal injection of lactoferrin (0.2 or 1 mg/200 microl/body) 1 hour prior to each LPS injection) (at 1:00 and 4:00 PM). To determine the effect of LF on plasma IL-6 level, mother mice were sacrificed and blood samples were obtained at 6 hours after the second treatment of LPS. RESULTS: Preterm delivery was induced by LPS in all mice on day 16 of gestation. Lactoferrin administration to LPS-treated mice significantly prolonged (p<0.001) gestation when compared with the LPS group. Plasma levels of IL-6 in the LPS group (1.628+/-115 pg/ml) were significantly higher (p<0.001) than in the untreated group (497+/-39 pg/ml). On the other hand, administration of lactoferrin (1 mg/body) to LPS-treated mice significantly suppressed (p<0.001) IL-6 levels (1.060+/-154 pg/ml). CONCLUSIONS: Lactoferrin exerts a preventive effect on the incidence of preterm delivery in mice via a suppression of plasma IL-6 augmentation by LPS.

Animals↗
PubMed1999

Antitumor activity and novel DNA-self-strand-breaking mechanism of CNDAC (1-(2-C-cyano-2-deoxy-beta-D-arabino-pentofuranosyl) cytosine) and its N4-palmitoyl derivative (CS-682).

We have studied the antitumor activity and the novel DNA-self-strand-breaking mechanism of CNDAC (1-(2-Ccyano-2-deoxy-beta-D-arabino-pentofuranosyl)cytosine) and its N4-palmitoyl derivative (CS-682). In vitro, CS-682 showed strong cytotoxicity against human tumor cells comparable with that of CNDAC; both compounds displayed a similar broad spectrum. In vivo, however, orally administered CS-682 showed a more potent activity against human tumor xenografts than CNDAC, 5'-deoxy-5-fluorouridine, 5-fluorouracil and 2',2'-difluorodeoxycytidine. Moreover, CS-682 was effective against various human organ tumor xenografts at a wide dose range and with low toxicity, and was effective against P388 leukemic cells resistant to mitomycin-C, vincristine, 5-fluorouracil or cisplatin in syngeneic mice. CNDAC, an active metabolite of CS-682, had a prolonged plasma half-life after repeated oral administrations of CS-682 but not after oral administrations of CNDAC itself. This difference may partially explain the higher antitumor activity of CS-682 relative to CNDAC. In both CNDAC- and CS-682-treated carcinoma cells, CNDAC 5'-triphosphate (CNDACTP) was generated and incorporated into a DNA strand. High performance liquid chromatography (HPLC) and mass spectrometric analysis of the nucleosides prepared by digestion of the DNA from the CNDAC-treated cells detected ddCNC (2'-Ccyano-2',3 '-didehydro-2',3 '-dideoxycytidine), which was shown to be generated only when the self-strand-breakage of CNDACTP-incorporated DNA occurred. The cytotoxicity of CNDAC was completely abrogated by the addition of 2'-deoxycytidine and was low against cells with decreased deoxycytidine kinase. Our results suggest that CNDAC is converted to CNDACMP by deoxycytidine kinase and that the resulting CNDACTP incorporated into a DNA strand as CNDACMP may induce DNA-self-strand-breakage. This novel DNA-self-strand-breaking mechanism may contribute to the potent antitumor activity of CS-682.

Administration, Oral↗
PubMed1999

Effects of red blood cells on the coagulation of blood in normal and preeclamptic pregnancies.

OBJECTIVE: The objective of this study was to determine the cellular effects of whole blood, especially of red blood cells, on the hypercoagulability of blood from patients with preeclampsia. STUDY DESIGN: The time elapsed between mixing and the onset of coagulation was measured by means of a highly sensitive rheometer for whole blood, platelet-rich plasma (in which red blood cells had been removed from whole blood), and platelet-free plasma from 3 groups of subjects: 25 nonpregnant women, 25 women with normal pregnancies, and 10 patients with preeclampsia. RESULTS: Time to coagulation for whole blood from patients with preeclampsia was significantly shorter than that for whole blood from women with normal pregnancies. However, there was no significant difference in time to coagulation for platelet-rich plasma between women with preeclampsia and those with normal pregnancies. CONCLUSION: Hypercoagulability of blood in preeclampsia appears to be strongly related to red blood cell alterations.

Adult↗
PubMed1999

Collateral expression of proangiogenic and tumorigenic properties in intestinal epithelial cell variants selected for resistance to anoikis.

Although in vitro anchorage-independent growth is widely used as a marker of cell transformation, the biological implications of this trait are poorly understood. We previously demonstrated that enforced anchorage-independent growth of a nontumorigenic, immortalized epithelial cell line (IEC-18) in multicellular spheroid culture results in massive apoptotic cell death. This death process, termed anoikis, is prevented by expression of transforming oncogenes, which also confer tumorigenic competence. This study examines whether acquisition of an anoikis-resistant phenotype is causally related to the tumorigenic capacity of transformed epithelial cells. Parental IEC-18 cells were subjected to 10 cycles of selection for survival in speroid culture. Unlike parental cells, the resulting anoikis-resistant variants (AR1.10 and AR2.10) formed relatively large tumors in nude mice. Both anoikis-resistant sublines displayed upregulated expression of vascular endothelial growth factor (VEGF), a potent angiogenesis stimulator. VEGF121 overexpression alone did not induce tumorigenic conversion of parental IEC-18 cells, which remained highly susceptible to anoikis. We postulate that both anoikis-resistance and angiogenic-competence contribute to tumor formation. Development of anoikis-resistance can be then viewed as a precondition for expression of the tumorigenic phenotype. Our results suggest that even when angiogenesis is not a rate limiting factor (e.g. in vitro) the selective pressures of solid tumor-like, 3-dimensional growth conditions favoring anoikis resistance result in collateral induction of a proangiogenic phenotype.

Animals↗
PubMed1999

The association of latent Epstein-Barr virus infection with hydroa vacciniforme.

Patients with hydroa vacciniforme (HV)-like eruptions and malignant potential have been reported from Asia and Mexico, and those patients frequently had an associated latent Epstein-Barr virus (EBV) infection. In order to elucidate the association of latent EBV infection with HV, we studied six children with typical manifestations of HV by detection of EBV genes and EBV-related RNAs in biopsy specimens from cutaneous lesions. Cutaneous lesions of all six children with typical HV contained EBV-encoded small nuclear RNA (EBER)+ cells in 3-10% of the dermal infiltrates, whereas no Bam HI-H, l-fragment (BHLF) mRNA, or transcripts encoding EA-D antigen, were detected. No EBER + cells were detected in other inflammatory or benign lymphoproliferative skin disorders tested. Polymerase chain reaction amplification confirmed the presence of EBV DNA sequences in five of six biopsy specimens from the patients. Latent EBV infection is associated with the development of cutaneous lesions of HV.

Burkitt Lymphoma↗
PubMed1999

Netherton's syndrome in siblings.

We report the perinatal presentation and evolution of Netherton's syndrome in siblings. The first patient, a female infant, presented with asphyxia at birth due to aspiration of desquamated scale, non-bullous ichthyosiform erythroderma, and hypernatraemic dehydration which she had for several days. Subsequently, she failed to thrive, with recurrent bacterial infections until 5 months of age, and very high serum IgE levels (1200 U/mL). Trichorrhexis invaginata and pili torti were identified at 18 months. The second patient was the younger brother of the first. Hydramnios and hyperechoic material in the amniotic fluid were observed by ultrasound at 35 weeks gestation, and he was delivered by elective Caesarian section at 40 weeks. At birth, no hair abnormality was demonstrated but, like his sister, his body was covered with thick caseous material, and he was erythrodermic. He failed to thrive, but serum IgE levels were normal until 5 months of age. Typical trichorrhexis invaginata was not observed until 7 months of age. Thus, the hair abnormality and high serum IgE levels in Netherton's syndrome appear late relative to the ichthyosiform erythroderma.

Female↗