Effects of a new histamine H2-receptor antagonist, Z-300, on gastric secretion and gastro-duodenal lesions in rats: comparison with roxatidine.

We examined the effects of a new compound, N-[3-[3-(piperidinomethyl)phenoxy]-propyl]-2-(2-hydroxyethyl-1- thio)acetamido.2-(4-hydroxy benzoyl)benzoate (Z-300), on the histamine H2-receptor, gastric secretion in rats and dogs, and acute gastro-duodenal lesions or chronic gastric ulcers in rats. Roxatidine acetate hydrochloride (roxatidine), a known histamine H2-receptor antagonist, was used as a reference compound. The pA2 values for Z-300 and roxatidine for the isolated guinea pig atrium were 6.8 and 7.0, respectively. These agents at less than 10(-5) M did not affect the contraction of guinea pig ileum in response to carbachol. Z-300, administered either orally or parenterally, significantly inhibited the basal and histamine-stimulated gastric acid secretion in rats. Gastric acid secretion stimulated by histamine, pentagastrin or carbachol in Heidenhain pouch dogs was also significantly inhibited by the compound. The effect persisted for greater than 7 hr in the case of histamine-stimulation. Oral Z-300 significantly protected the gastric mucosa from water-immersion stress-, indomethacin-, aspirin- and HCl.ethanol-induced lesions and protected the duodenal mucosa against mepirizole- and cysteamine-induced ulcers. These effects on gastric secretion and lesion formation were, as a whole, stronger than those observed with roxatidine. Z-300, but not roxatidine, significantly accelerated the spontaneous healing of acetic acid ulcers induced in rats and prevented the delay in ulcer healing caused by indomethacin. The mechanism of action of Z-300 on acute lesions and chronic ulcers appears to be mostly related to its potent antisecretory and mucosal-protective activities.     

Evaluation of fatty acid metabolism-related gene expression in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most frequent causes of abnormal liver dysfunction, and its prevalence has markedly increased; however, the mechanisms involved in the pathogenesis of NAFLD have not been thoroughly investigated in humans. In this study, we evaluated the expression of fatty acid metabolism-related genes in NAFLD. Real-time RT-PCR was performed using liver biopsy samples from 12 NAFLD patients. The target genes studied were: acetyl-CoA carboxylase (ACC) 1, ACC2, and fatty acid synthase (FAS) for the evaluation of de novo fatty acid synthesis; carnitine palmitoyltransferase 1a (CPT1a), long-chain acyl-CoA dehydrogenase (LCAD), and long-chain L-3-hydroxyacyl-coenzyme A dehydrogenase alpha (HADHalpha) for beta-oxidation in the mitochondria; peroxisome proliferator-activated receptor- (PPAR-) alpha and cytochrome P450 2E1 (CYP2E1) for oxidation in peroxisomes and microsomes (endoplasmic reticulum) respectively; and diacylglycerol O-acyltransferase 1 (DGAT1), PPAR-gamma, and hormone sensitive lipase (HSL) for triglyceride synthesis and catalysis. In NAFLD, expression of ACC1 and ACC2, but not FAS was increased, indicating that de novo fatty acid synthesis is enhanced in NAFLD. In contrast, expression of CTP1a, a rate-limiting enzyme, was remarkably decreased, indicating that beta-oxidation in the mitochondria was decreased, although the expression of LCAD and HADHalpha was increased. Expression of PPAR-alpha was increased, whereas that of CYP2E1 was reduced. The expression of DGAT1, PPAR-gamma, and HSL was enhanced. These data suggest that in NAFLD, increased de novo synthesis and decreased beta-oxidation in the mitochondria lead to accumulation of fatty acids in hepatocytes, although the extent of oxidation in peroxisomes and microsomes remains unclear.     

Endothelium and thrombomodulin: expression and distribution of thrombomodulin on altered endothelium and neoplastic syncytiotrophoblast

We investigated the expression of thrombomodulin (TM) on endothelium in some pathologic states. We used the cultured endothelial cells treated with interleukin-1 (IL-1) and propagated cells by serial subculture for extended periods of time and assessed cell-surface TM molecules. We also studied the distribution of TM on surgical specimens of chorionic diseases, angiosarcoma and on several established cell lines of human choricarcinoma. Subculture of human umbilical vein endothelial cells (HUVE) up to 2 months (approximately 16 subcultures) decreased the number of cell-surface TM molecules by approximately 20% compared to the primary culture. The number of TM molecules also decreased on HUVE treated by IL-1. The treatment of the cells with IL-1 also induced change of shape. TM was found not only normal syncytiotrophoblast but also on neoplastic syncytiotrophoblast of choriocarcinoma and hydatidiform mole. However, TM was not expressed on the three established cell lines. TM was found on various types of vascular tumors, including angiosarcoma.     

Arg-Gly-Asp (RGD) peptide ameliorates carbon tetrachloride-induced liver fibrosis via inhibition of collagen production and acceleration of collagenase activity

Liver cirrhosis is caused by a relative imbalance between synthesis and degradation of collagens. Arg-Gly-Asp (RGD) peptide is a major adhesive domain of several extracellular matrix (ECM) components, such as that involved in the binding of fibronectin to the alpha5beta1 integrin receptor. We previously reported that RGD peptide increased the expression of matrix metalloproteinase in hepatic stellate cells (HSCs) which play a major role in hepatic fibrosis. We evaluated whether RGD-peptides inhibit the progression of liver fibrosis in an animal model of carbon tetrachloride-induced hepatotoxicity. RGD peptide (GRGDS) (1 mg/kg body weight) was injected intraperitoneally (i.p.) 3 times a week for one month. The group treated with control peptide (GRGES) showed pathologically typical hepatic fibrosis, while the RGD-treated group showed minimal fibrotic changes. The liver contents of collagen and hydroxyproline in the RGD-treated group was significantly lower than that of the control group. Collagenase activity measured in liver homogenates was significantly higher in the treated group than in the control group. In an in vitro study using TWNT-4 cells derived from human HSCs, RGD peptide (100 mug/ml) reduced the expression of type I collagen and tissue inhibitor of matrix metalloproteinase-1, and increased that of matrix metalloproteinase-1. These results indicated that RGD peptides inhibited liver fibrosis associated with both decreased collagen production and increased collagenase acitivity, and suggested that RGD peptide might be useful for the therapy of hepatic fibrosis.     

Wnt signaling plays an essential role in neuronal specification of the dorsal spinal cord

In the developing spinal cord, signals from the roof plate are required for the development of three classes of dorsal interneuron: D1, D2, and D3, listed from dorsal to ventral. Here, we demonstrate that absence of Wnt1 and Wnt3a, normally expressed in the roof plate, leads to diminished development of D1 and D2 neurons and a compensatory increase in D3 neuron populations. This occurs without significantly altered expression of BMP and related genes in the roof plate. Moreover, Wnt3a protein induces expression of D1 and D2 markers in the isolated medial region of the chick neural plate, and Noggin does not interfere with this induction. Thus, Wnt signaling plays a critical role in the specification of cell types for dorsal interneurons.     

Toward a society of maturity and harmony - a new plan for achieving longer and healthier life expectancies in Japan

Because of its rapidly increasing older population, Japan urgently needs sound and rapid progress in gerontology in order to create a new society, in which both young and old can live their active and creative lives in harmony. In order to establish such a society of maturity and harmony, the Japanese Government has begun a major national project, heralded by the establishment of a National Research Center of Gerontology. This center will begin functioning in 1995 in Nagoya, with the combined support of the National and the Aichi Prefectural Governments. This center will consist of a newly constructed research institute of 8000 m(2) with an attached animal facility, and a geriatric hospital with 500 beds for patients with dementia, those in a bed-ridden state, as well as those with various geriatric diseases. The close collaboration of the hospital and the research institute is expected to facilitate further progress in gerontology as well as in the education and training of specialized geriatricians and future leaders in gerontological research in Japan. In order to promote rapid progress in gerontology, a new foundation, the Japan Foundation for Aging and Health, has already begun its activities including the financial support of gerontological research, an international exchange program for scientists in gerontology, and the holding of international symposia in various fields of gerontology. With this accomplishment of the new Institute in 1995, activities for international collaborations will be dramatically expanded. This paper briefly covers the history as well as some future prospects of gerontology in Japan in conjugation with the establishment of the National Research Center of Gerontology.     

Controlled trial of thyrotropin releasing hormone tartrate in ataxia of spinocerebellar degenerations

The clinical efficacy, dose-response relationship, and safety of TRH-T (thyrotropin releasing hormone tartrate) were assessed in 290 patients with spinocerebellar degeneration (SCD) in a 2-week, double-blind study using placebo as control. 254 patients satisfied the criteria for inclusion in evaluation of the drug efficacy. The patients were treated with TRH-T in an intramuscular dose of 2 mg, 0.5 mg or 0 mg (placebo) as TRH once a day for 2 weeks. Clinical responses to these treatments were evaluated 3 times: at the end of weeks 1 and 2 of treatment and a week after the end of treatment. The results of "global improvement rating" as well as those of "ataxia improvement rating" showed that both 2 mg and 0.5 mg TRH-T treatments were significantly superior to placebo treatment in patients with predominantly cerebellar form of SCD. The effect was well maintained a week after the end of the 2-week treatment in the patients who were given TRH-T in daily dose of 2 mg and showed improvement at the end of treatment. The results of "improvement rating of each symptom" revealed that 2 mg treatment was significantly more effective than placebo for disorders of standing, gait, speech and writing. In the patients who had no pyramidal involvement or disorder of deep sensation, the drug efficacy and dose-response relationship were evident. Adverse reactions to the drug such as headache, feeling febrile and nausea were observed in 50% of the patients on 2 mg treatment, in 38% of those on 0.5 mg treatment and in 21% of those on placebo patient, however, discontinued treatment because of adverse reactions.     

Alteration of regional cerebral blood flow to thyrotropin-releasing hormone therapy in acute encephalitis and encephalopathy during childhood.

BACKGROUND: Thyrotropin-releasing hormone (TRH) is now used as a therapeutic agent for various neurological disorders. Animal study has shown that TRH was attributable to increased cerebral blood flow (CBF). AIMS: There have been occasional reports that TRH therapy was effective for improving symptoms of persistent disturbance of consciousness after acute encephalitis or encephalopathy during childhood. To determine whether TRH has an effect on increasing CBF to patients who have consciousness disturbance caused by acute encephalitis or encephalopathy, and to determine the optimal method of administration. METHODS: Sixteen patients aged 0.7-10.9 years (mean age, 3.2+/-3.1 years) who presented with persistent disturbance of consciousness resulting from acute encephalitis or encephalopathy and were treated with TRH. Regional CBF (rCBF) was measured by single photon emission computed tomography before and after TRH therapy. The alteration rates of rCBF were compared between the divided two groups concerning the dose levels, dosing periods, and treatment lags. RESULTS: The alteration rates of rCBF of the high dose group were higher than those of the low dose group. Differences in the dosing periods and treatment lags did not cause any significant difference of the alteration rates of rCBF. CONCLUSION: The study showed that higher alteration rates of the CBF were observed in the higher dosing group, and TRH have the potency of increasing CBF. TRH therapy would have the potential for effective treatment of persistent consciousness disturbance caused by childhood acute encephalitis or encephalopathy.     

Overexpression of cyclin‐dependent kinase 4 protein in extramammary Paget's disease

Cyclin‐dependent kinase 4 and 6 (CDK4/6) plays an important role in cell cycle progression, and the CDK4/6–cyclin D1 complex controls the cell cycle transition from G₁ phase to S phase. CDK4 is enhanced in several types of cancers and CDK4/6 inhibitors attenuate the proliferation of several types of cancer in vitro/in vivo. The purpose of our study was to investigate the expression pattern of CDK4 and evaluate its clinical importance in extramammary Paget's disease (EMPD). Almost all EMPD tissues were positive for CDK4, and metastatic lesions had a similar immunostaining intensity to primary lesions. In addition, CDK4 protein levels were positively correlated with those of cyclin D1 protein. Taken together, CDK4 may assume a crucial role in EMPD progression.