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Biomedical subjects

H Endo

Publications and source records attributed to H Endo.

At least 19 recordsLinked to original sources

RhoC is essential for TGF-beta1-induced invasive capacity of rat ascites hepatoma cells.

Transforming growth factor-beta1 (TGF-beta1) is a multifunctional growth factor that plays a role in cell proliferation, differentiation, extracellular matrix production, apoptosis, and cell motility. We show here that TGF-beta1 increased the invasiveness of MM1 cells, which are a highly invasive clone of rat ascites hepatoma cells. Both mRNA and protein levels of RhoC but not RhoA in TGF-beta1-treated MM1 cells increased. In parallel with this increase in expression, RhoC activity was induced by TGF-beta1 treatment. When RhoC was overexpressed in MM1 cells, the invasive capacity increased. The RhoC-overexpressing cells formed more nodules than did mock cells when injected into rat peritoneum. Furthermore, when RhoC expression was reduced by transfection with shRNA/RhoC, the invasiveness of MM1 cells decreased with concomitant suppression of RhoC expression. Thus, the induced expression of RhoC by TGF-beta1 in MM1 cells plays a critical role in TGF-beta1-induced cell migration.

Animals↗

Mitochondrial translocation of p53 underlies the selective death of hippocampal CA1 neurons after global cerebral ischaemia.

p53, a tumour suppressor, is involved in DNA repair and cell death processes and mediates apoptosis in response to death stimuli by transcriptional activation of pro-apoptotic genes and by transcription-independent mechanisms. In the latter process, p53 induces permeabilization of the outer mitochondrial membrane by forming an inhibitory complex with a protective Bcl-2 family protein, resulting in cytochrome c release in several cell line systems. However, it is unclear how the mitochondrial p53 pathway mediates neuronal apoptosis after cerebral ischaemia. We examined interaction between the mitochondrial p53 pathway and vulnerable hippocampal CA1 neurons using a tGCI (transient global cerebral ischaemia) rat model. We showed mitochondrial translocation of p53 and its binding to Bcl-X(L). Mitochondrial p53 translocation, interaction between p53 and Bcl-X(L), and cytochrome c release from mitochondria and subsequent CA1 neuronal death were prevented by pifithrin-alpha, a p53-specific inhibitor. These results suggest that the mitochondrial p53 pathway plays a role in delayed CA1 neuronal death after tGCI.

Animals↗

Psoriatic skin expresses the transcription factor Gli1: possible contribution of decreased neurofibromin expression.

BACKGROUND: Psoriasis is a chronic inflammatory disorder of skin characterized by hyperproliferation of keratinocytes. Intracellular signalling pathways inducing the hyperproliferation of keratinocytes remain to be elucidated. An inhibitor of Hedgehog (Hh) signalling, cyclopamine, was recently reported to clear psoriatic skin lesions, suggesting involvement of the Hh signalling pathway in the hyperproliferation of lesional keratinocytes. We have previously observed activation of the Hh signalling pathway in Schwann cells of plexiform neurofibroma in neurofibromatosis type 1 (NF1), which results from functional loss of the NF1 encoding protein, neurofibromin. In psoriasis, deficiency of neurofibromin expression has been observed in lesional keratinocytes. OBJECTIVES: To investigate whether the Hh signalling pathway would be activated in psoriasis and whether inhibition of neurofibromin expression would enhance the activation of the Hh signalling pathway. METHODS: Activation of the Hh signalling pathway was examined by protein expression of one of the target genes, GLI1, coding for the transcription factor Gli1. Immunohistochemical studies were performed on seven psoriatic skin samples and seven control normal skin samples with a standard immunoperoxidase technique. mRNA expression of GLI1 was analysed by reverse transcriptase-polymerase chain reaction in HaCaT cells transfected with double-strand small interfering RNA for NF1. RESULTS: Our results showed Gli1 expression in psoriatic skin but not in control normal skin. Inhibition of neurofibromin expression in HaCaT cells upregulated mRNA expression of GLI1. CONCLUSIONS: Our findings indicate that the Hh signalling pathway is activated in psoriasis and that neurofibromin deficiency may upregulate the pathway.

Cell Line↗

Immunolocalization of gastrin-releasing peptide (GRP) in the uteroplacenta of the mouse deer.

The considerable phylogenetical differences between mouse deer and other ruminants have been established by means of DNA sequence analysis and anatomical observations. To clarify the physiological role of the uteroplacenta of the mouse deer, immunohistochemical observation was attempted by using GRP, which has been suggested as a novel regulatory peptide in the female reproductive tract, as an indicator to compare with other ruminants. Strong positive reactions for the GRP were detected in the uterine glands of the pregnant animals, but not in the non-pregnant ones. Although the placenta of the mouse deer is categorized as a diffuse placenta that is different from other ruminants' polycotyledonary placenta, in terms of GRP immunoreactivity, the mouse deer placenta can be classified as a synepithecholial placenta like the other ruminants'. The secretion of GRP from the uterine glands is of some importance to the fetus in the mouse deer.

Animals↗

A classification of the fibrin network structures formed from the hereditary dysfibrinogens.

OBJECTIVE: The main objective was to study the relationships of the molecular defects in 38 dysfibrinogens with their fibrin networks. METHODS AND RESULTS: Scanning electron microscopic analyses revealed that all the fibrins formed under the same conditions had networks composed of either normal thickness fibers or thin fibers, accompanied by a variety of alterations in the network structure and characteristics. We classified these fibrin networks into five classes, designated normal, less-ordered, porous A, porous B and lace-like networks. The dysfibrinogens with defects in fibrinopeptide A release or the E:D binding sites formed normal or less-ordered networks, while those with defects in the D:D association formed porous A networks composed of many tapered terminating fibers, despite having fibers of normal width, and containing many pores or spaces. The porous B and lace-like networks were composed of highly branched thin fibers because of defects in the lateral association among protofibrils, and the major difference between them was the porosity of the porous B networks. All the porous B networks were easily damaged by mechanical stress, whereas the lace-like networks retained high resistance to such stress, indicating that the network strength was not dependent on the fiber width, but on the porosity that led to fragility of the network. CONCLUSION: Impairment of the D:D association is the major disturbing factor that leads to the formation of porous fibrin networks. The porosity may be introduced by severe impairment of the D:D association, as well as the lateral association, as has often been observed by extra glycosylation or defects in Ca2+ binding.

Afibrinogenemia↗

Bioelectronic detector with monoamine oxidase for halitosis monitoring.

Methyl mercaptan (MM) is known as one of the major chemicals of halitosis (bad breath). In this study, a bioelectronic gas sensor (bio-detector) for gaseous MM was developed and was applied to measure halitosis in breath. The bio-detector consisted of a Clark-type dissolved oxygen electrode, a monoamine oxidase type-A (MAO-A) immobilized membrane and a reaction unit that had liquid and gaseous compartments separated by a hydrophobic porous polytetrafluoroethylene (PTFE) diaphragm membrane. The tip of the electrode covered with MAO-A membrane was placed into the liquid compartment as touching to the PTFE diaphragm membrane. In order to amplify the bio-detector output, a substrate regeneration cycle caused by coupling the monooxygenase with l-ascorbic acid as reducing reaction with reagent system, was applied. The results of MM vapor measurements showed the calibration range of the bio-detector for MM vapor was from 0.087 to 11.5 ppm (correlation coefficient: 0.993) and included the human sense of smell level 5 (0.2 ppm). The bio-detector had good selectivity being attributed to enzyme specificity was obtained for several substances (trimethyl amine, ammonia, dimethyl sulfide, etc.). The bio-detector was applied for halitosis measurement. Expired gases in five subjects were sampled every hour and the concentrations of MM in the expired gases were monitored. The output of bio-detector showed behaviour of halitosis level changes in a day such as increasing with passage of time and decreasing after eating.

Biosensing Techniques↗

Regulatory expression of lipoxin A4 receptor in physiologically estrus cycle and pathologically endometriosis.

Expression of receptors for prostaglandin (PG) and leukotriene (LT) has been reported to detect in endometrium and smooth muscle of uterus, suggesting involvement of these arachidonic metabolites in endometrial pathology and reproductive biology. Lipoxin (LX), which is produced by lipoxygenases from arachidonic acid, has been characterized as an anti-inflammatory lipid mediator. Biological actions of Lipoxin A4 (LXA4) are mediated through the specific receptor. In order to know roles of LXA4 in female genitalia, expression of LXA4 receptor mRNA was quantified by real-time polymerase chain reaction. Significantly higher expression of the receptor was detected in endometrium and myometrium than ovary in normal rats. Expression of the receptor in endometrium was increased at stage of proestrus cycle under physiological condition. Exogenous administration of progesterone into female rats significantly reduced the expression, while administration of estradiol or pregnant mare serum gonadotropin (PMSG) did not. Both, endometrium in experimental endometriosis induced in rats and the tissues from patients with ectopic endometriosis showed a higher expression of LXA4 receptor compared to the normal tissues. In contrast, expressions of BLT1 and BLT2, receptors for leukotriene B4, did not change in the endometriosis. These observations suggest a possible role of LXA4 and the receptor under physiological estrus cycle and pathological condition as endometriosis.

17-alpha-Hydroxyprogesterone↗

Stereotactic radiosurgery followed by whole ventricular irradiation for primary intracranial germinoma of the pineal region.

Intracranial germinomas can be cured by radiotherapy and/or chemotherapy. Three patients with pineal germinoma were treated with stereotactic radiosurgery using the gamma knife (10 - 12 Gy) to the tumors followed by whole ventricular irradiation (24 Gy). All patients had solitary pineal tumor measuring less than 3 cm, clinically compatible with germinoma, normal cerebrospinal fluid (CSF) and serum levels of alpha-fetoprotein and beta-human chorionic gonadotropin, no disseminated disease on spinal magnetic resonance (MR) imaging, and no abnormal CSF cytology. All patients showed complete response to the combined radiotherapy, and MR imaging has shown no recurrence of the tumor. Combined radiotherapy using gamma knife radiosurgery is effective for pineal germinoma, and reduced the cost of treatment with less need for hospitalization.

Adult↗

Characteristics of metachronous multiple early gastric cancers after endoscopic mucosal resection.

BACKGROUND AND STUDY AIMS: Endoscopic mucosal resection (EMR) of early gastric cancer is a minimally invasive procedure. The incidence and characteristics of metachronous multiple gastric cancers were investigated in a retrospective study in patients with early gastric cancer after EMR treatment. PATIENTS AND METHODS: A total of 143 patients with early gastric cancer who had undergone EMR treatment were periodically followed up with endoscopic examinations for 24 months or longer. RESULTS: The median period of endoscopic follow-up was 57 months (range 24 - 157 months). None of the patients died of gastric cancer, and there were no treatment-related deaths. Five patients died of other diseases. Of 20 patients (14 %) with metachronous multiple gastric cancers, 15 were treated by EMR. One patient with differentiated submucosal cancer and four with undifferentiated cancers underwent surgery. Sixteen patients (11 %) had synchronous multiple early gastric cancer lesions within 1 year of the initial EMR. About half of the multiple lesions were located in the same third of the stomach as the primary lesion, and most lesions were similar in macroscopic type to the primary lesions. Most multiple lesions were of the differentiated type. CONCLUSIONS: Annual endoscopic examinations can preserve the whole stomach in most patients with early gastric cancer after successful EMR.

Adenocarcinoma↗

Stereotactic radiosurgery for nodular dissemination of anaplastic ependymoma.

Dissemination of primary intracranial ependymoma occurs in 10% of all cases and is difficult to treat, so this may be one of the major reasons for the poor prognosis. Two patients with nodular dissemination of anaplastic ependymoma were treated with repeated stereotactic radiosurgery using the gamma knife (GK), resulting in tumour control over 21 months. GK radiosurgery is a safe and effective treatment option for providing good local control in patients with nodular dissemination of ependymoma.

Adolescent↗

A phase I study of S-1 combined with weekly cisplatin for metastatic gastric cancer in an outpatient setting.

A dose-escalation study was conducted for patients with metastatic gastric cancer to determine the recommended dose of weekly intravenous (i.v.) cisplatin combined with a fixed dose of a new oral dihydropyrimidine dehydrogenase-inhibitory fluoropyrimidine, S-1, on an outpatient basis. Secondary endpoints were to define the toxicity profile and to determine tumour responses. S-1 was fixed at a dose of 70 mg/m(2)/day and was administered for 2 weeks followed by a 1-week rest. Three dose levels of cisplatin (10, 15 and 20 mg/m(2)) were studied. Cisplatin was infused over 30 min on days 1 and 8. 20 patients were enrolled. No dose-limiting toxicities (DLTs) were recorded during the administration of cisplatin up to 20 mg/m(2), except for grade 3 diarrhoea and stomatitis in one patient at dose level 3. No grade 4 adverse events occurred. However, grade 2 gastrointestinal adverse reactions, such as nausea and anorexia, were seen in 7 of 13 patients at dose level 3 within the first two treatment cycles. This was determined to be the maximum acceptable level that would not negate the advantages observed with use of an oral drug such as S-1. An objective tumour response was seen at all dose levels, and the overall response rate in the 18 patients evaluated was 61%. A higher response rate of 78% was observed in 9 patients who had received no prior chemotherapy. Oral S-1 with weekly cisplatin is a feasible and promising combination regimen that is appropriate for an outpatient setting. A randomised phase II study comparing this combination with S-1 alone in chemo-nai;ve patients is warranted.

Adult↗

Prostaglandin E2 downregulates interleukin-12 production through EP4 receptors in human monocytes stimulated with lipopolysaccharide from Actinobacillus actinomycetemcomitans and interferon-gamma.

In the present study, we examined the effect of prostaglandin (PG) E2 on interleukin (IL) -12 production in monocytes stimulated with a combination of lipopolysaccharide (LPS) from Actinobacillus actinomycetemcomitans and interferon-gamma (A. actinomycetemcomitans-LPS/IFN-gamma). Indomethacin, a cyclooxygenase inhibitor, enhanced IL-12 production, but inhibited PGE2 generation in A. actinomycetemcomitans-LPS/IFN-gamma-stimulated monocytes. Exogenous PGE2 inhibited IL-12 release in the cells. EP2, EP3 and EP4 receptor mRNA expression was detected in monocytes by reverse transcription-polymerase chain reaction. 11-deoxy-PGE1 (an EP2/EP4 agonist) inhibited IL-12 production in A. actinomycetemcomitans-LPS/IFN-gamma-challenged monocytes, whereas butaprost (an EP2 agonist) or ONO-AP-324 (an EP3 agonist) had no effect on IL-12 production. Dibutyryl cAMP, a cAMP analogue, and forskolin, an adenylate cyclase activator, mimicked depression of IL-12 production by PGE2. From these results, we suggest that PGE2 inhibits IL-12 production via EP4 receptors by cAMP-dependent pathways in A. actinomycetemcomitans-LPS/IFN-gamma-challenged monocytes.

Aggregatibacter actinomycetemcomitans↗

A possible paracrine hedgehog signalling pathway in neurofibromas from patients with neurofibromatosis type 1.

BACKGROUND: Hedgehogs (Hhs) and their receptors are involved in organ development as well as in tumorigenesis observed in basal cell carcinoma. Among Hhs, Desert hedgehog secreted from Schwann cells mediates the formation of peripheral nerve sheaths. However, there has been no study on the role of Hhs and their receptors in tumorigenesis of neurofibromas in neurofibromatosis type 1 (NF1). OBJECTIVES: To clarify the expression and localization of Hhs and their receptors in neurofibromas of NF1 patients. METHODS: Expression of Hhs and their receptors was studied by immunohistochemistry using neurofibromas from NF1 patients and control normal skin samples. RESULTS: In neurofibromas, CD57-positive tumour cells with delicate elongated processes were positive for the receptor PTCH2. Perineurial cells of involved nerves within neurofibromas as well as those of normal cutaneous nerves expressed Indian hedgehog and Sonic hedgehog. Schwann cells of normal cutaneous nerves were positive for PTCH2. CONCLUSIONS: Our study suggests that a paracrine Hh signalling pathway may be involved in tumorigenesis of neurofibromas in NF1.

CD57 Antigens↗

The expression of nectin-1alpha in normal human skin and various skin tumours.

BACKGROUND: A novel cell-cell adhesion system that consists of nectin and afadin has been identified at cadherin-based cell-cell adherens junctions. Nectin is a Ca2+-independent homophilic and heterophilic cell adhesion molecule that belongs to the immunoglobulin superfamily. Nectin has recently been shown to serve as an alpha-herpesvirus entry and cell-cell spread mediator. In spite of the ubiquitous expression of nectin-1alpha, its detailed localization in human skin has not been examined so far. OBJECTIVES: To investigate the localization of nectin-1alpha in normal human skin and the alteration of its expression in malignant skin tumours. METHODS: Immunohistochemistry was employed to determine the expression of nectin-1alpha and other adhesion molecules. RESULTS: We detected nectin-1alpha in normal human epidermis, follicles and eccrine ducts. Nectin-1alpha was colocalized with E-cadherin at cell-cell adherens junctions of the epidermis. The concentration of the nectin-afadin system at cell-cell adherens junctions was reduced in the early stage of malignant transformation of keratinocytes, such as in basal cell carcinomas and squamous cell carcinomas, where the cadherin-catenin system was preserved. Nectin-1alpha at cell-cell adherens junctions was reduced in human epithelial cancer cells located at the advancing border of the tumour. CONCLUSIONS: Our results showed that nectin-1alpha is located at cell-cell adherens junctions in human skin and that reduction of nectin-1alpha at cell-cell adherens junctions may be involved in the invasion of squamous cell tumours.

Aged↗

Increased procollagen alpha1(I) mRNA expression by dermal fibroblasts in melorheostosis.

We report a patient with melorheostosis in whom increased procollagen alpha1(I) mRNA expression and alpha1(I), alpha2(I) and alpha1(III) collagen secretion were observed in dermal fibroblasts obtained from a skin biopsy overlying the involved bone. The patient was a 53-year-old man with melorheostosis lesions over the left knee joint. Multiple pigmented macules were present on the medial aspect of the lower left leg. Hyperpigmentation of the basal keratinocytes, thick-walled vessels in the reticular dermis, and proliferation of normal-appearing collagen around the hair follicles were observed histologically.

Fibroblasts↗