HMGIY is the target of 6p21.3 rearrangements in various benign mesenchymal tumors

The presence of specific keratins can be of diagnostic value for studying normal and neoplastic epithelium of the vulva. The aim of the present study was to investigate normal, preneoplastic and neoplastic epithelium of the vulva. Keratins 5, 6 and 18, identified by a polyspecific anti-human CK antibody (clone LP 34, DAKO), and the keratin subtypes 7, 10, 14, 18, 19 and 20 of normal, dysplastic and malignant vulval epithelium (paraffin-embedded sections) were detected by immunohistochemical APAAP staining. Keratins 5, 6, and 18 (clone LP 34) and keratin subtype 10 are expressed in the upper third of the normal vulval epithelium. In mild and moderate intraepithelial neoplasia only a few cells express these keratins. In patients with severe intraepithelial neoplasia (VIN III) the expression of these keratins seems to be associated with recurrence of the disease. In biopsy specimens of patients without recurrence we find positive results for keratins 5, 6 and 18 (clone LP 34) and keratin 10. If patients have a recurrence of the disease, expression of these keratins is only diffuse or is absent. The expression of these keratin subtypes in vulval carcinomas is mostly seen in differentiated cells. There was no association between recurrence and keratin pattern. We have not found any other expression of the tested keratin subtypes in VIN and in vulval carcinoma.     

Mannose-6-phosphate/insulin-like growth factor-II receptor is a receptor for retinoic acid

Retinoic acid (RA) exerts diverse biological effects in the control of cell growth in embryogenesis and oncogenesis. These effects of RA are thought to be mediated by the nuclear retinoid receptors. Mannose-6-phosphate (M6P)/insulin-like growth factor-II (IGF-II) receptor is a multifunctional membrane glycoprotein that is known to bind both M6P and IGF-II and function primarily in the binding and trafficking of lysosomal enzymes, the activation of transforming growth factor-beta, and the degradation of IGF-II. M6P/IGF-II receptor has recently been implicated in fetal development and carcinogenesis. Despite the functional similarities between RA and the M6P/IGF-II receptor, no direct biochemical link has been established. Here, we show that the M6P/IGF-II receptor also binds RA with high affinity at a site that is distinct from those for M6P and IGF-II, as identified by a photoaffinity labeling technique. We also show that the binding of RA to the M6P/IGF-II receptor enhances the primary functions of this receptor. The biological consequence of the interaction appears to be the suppression of cell proliferation and/or induction of apoptosis. These findings suggest that the M6P/IGF-II receptor mediates a RA response pathway that is important in cell growth regulation. This discovery of the interaction of RA with the M6P/IGF-II receptor may have important implications for our understanding of the roles of RA and the M6P/IGF-II receptor in development, carcinogenesis, and lysosomal enzyme-related diseases.     

M2, M3 and M4, but not M1, muscarinic receptor subtypes are present in rat spinal cord

Muscarinic receptors in the spinal cord have been shown to mediate antinociception and alter blood pressure. Currently, there is much interest in identifying which muscarinic receptor subtypes regulate these functions. Toward that end, this study aimed to identify and localize the muscarinic receptor subtypes present in spinal cord using in vitro receptor autoradiography with [3H]-pirenzepine and [3H]-N-methylscopolamine. The results showed that M2 binding sites were distributed throughout the dorsal and ventral horns, whereas M3 binding sites were localized to laminae I to III of the dorsal horn. Only background levels of M1 binding sites were detected. Saturation binding assays using [3H]-pirenzepine in spinal cord homogenates confirmed the absence of M1 receptors. Competition membrane receptor assays using [3H]-N-methylscopolamine and the unlabeled antagonists pirenzepine, 11-2[(-[(diethylamino)methyl]-1-piperidinyl)-acetyl]-5, 11-dihydro 6H-pyrido(2, 3-b)(1, 4) benzodiazepine-one, methoctramine, and methoctramine in combination with atropine corroborated the autoradiographic findings and also revealed the presence of M4 binding sites. The finding that M2 and M3 binding sites were localized to the superficial laminae of the dorsal horn where nociceptive A delta and C fibers terminate suggests the possibility that either or both of these muscarinic receptor subtypes modulate antinociception. The present demonstration of M4 binding sites in spinal cord is consistent with the possibility that M2 and/or M4 receptors are involved in the regulation of blood pressure at the spinal level.     

Ozone-induced loss of neuronal M2 muscarinic receptor function is prevented by cyclophosphamide

We tested the hypothesis that inflammatory cells mediate the loss of neuronal M2 muscarinic receptors in the lung after ozone exposure. Pathogen-free guinea pigs treated with cyclophosphamide (30 mg.kg-1.day-1 i.p. for 7 days) before exposure to ozone were compared with untreated ozone-exposed animals. This dose of cyclophosphamide significantly reduced leukocytes in peripheral blood and bronchoalveolar lavage fluid. Twenty-four hours after ozone, muscarinic receptor function was tested in anesthetized animals. In air-exposed guinea pigs, vagally induced bronchoconstriction was attenuated by the muscarinic agonist pilocarpine (0.1-100 micrograms/kg i.v.) and potentiated by the selective M2 antagonist gallamine (0.1-10 mg/kg i.v.), indicating that the neuronal M2 muscarinic receptors were functioning. These responses were significantly reduced after ozone, indicating loss of neuronal M2 muscarinic receptor function. However, in those animals treated with cyclophosphamide, M2 muscarinic receptor function was not altered by ozone. These data suggest that ozone-induced loss of neuronal muscarinic receptor function is mediated via inflammatory cells and that the link between ozone-induced hyperresponsiveness and inflammation may be the neuronal M2 muscarinic receptor.     

Nramp2 is mutated in the anemic Belgrade (b) rat: evidence of a role for Nramp2 in endosomal iron transport

The Belgrade (b) rat has an autosomal recessively inherited, microcytic, hypochromic anemia associated with abnormal reticulocyte iron uptake and gastrointestinal iron absorption. The b reticulocyte defect appears to be failure of iron transport out of endosomes within the transferrin cycle. Aspects of this phenotype are similar to those reported for the microcytic anemia (mk) mutation in the mouse. Recently, mk has been attributed to a missense mutation in the gene encoding the putative iron transporter protein Nramp2. To investigate the possibility that Nramp2 was also mutated in the b rat, we established linkage of the phenotype to the centromeric portion of rat chromosome 7. This region exhibits synteny to the chromosomal location of Nramp2 in the mouse. A polymorphism within the rat Nramp2 gene cosegregated with the b phenotype. A glycine-to-arginine missense mutation (G185R) was present in the b Nramp2 gene, but not in the normal allele. Strikingly, this amino acid alteration is the same as that seen in the mk mouse. Functional studies of the protein encoded by the b allele of rat Nramp2 demonstrated that the mutation disrupted iron transport. These results confirm the hypothesis that Nramp2 is the protein defective in the Belgrade rat and raise the possibility that the phenotype shared by mk and b animals is unique to the G185R mutation. Furthermore, the phenotypic characteristics of these animals indicate that Nramp2 is essential both for normal intestinal iron absorption and for transport of iron out of the transferrin cycle endosome.     

Prognostic evaluation in supratentorial astrocytic tumors using p53, epidermal growth factor receptor, c-erbB-2 immunostaining

Molecular pathology may play an important role in predicting the tumor prognosis, particularly p53, epidermal growth factor receptor (EGFR), and c-erbB-2. We investigated six variables (age, sex, histopathological grade, p53, EGFR, and c-erbB-2) to identify the role of such factors in predicting the outcome of patients with supratentorial astrocytic tumors. Thirty-seven tumors were studied including 9 well-differentiated astrocytomas (WHO grade 2), 19 anaplastic astrocytomas (WHO grade 3), and 9 glioblastomas multiforme (WHO grade 4). In univariate analysis, no statistical significance was found for the prognostic value of the sex (p = 0.2188), age (p = 0.5530), p53 immunostain (p = 0.2194), and c-erbB-2 immunostain (p = 0.4203). A significant correlation with the prognosis was found with respect to the histopathological grade (p = 0.0049) and EGFR expression (p = 0.0284). In multivariate analysis, the histopathological grade was shown to be significant independent variable (p = 0.0152). In WHO grade 2 and 3 astrocytomas, expression of p53 or EGFR was associated with poorer patient outcome. In glioblastomas, expression of p53 was also associated with poorer prognosis. Our studies suggested that conventional histological assessment of supratentorial astrocytic tumors remains the best guide to prognosis. Although no statistical significance was found between the immunostains and survival in variant grades of astrocytomas, there was a trend between p53 or EGFR proteins expression and the decrease of survival time.     

Regression of C6 rat brain tumors by cells expressing an antisense insulin-like growth factor I receptor RNA

The aim of the study was to measure incidence of oral impacts on daily performances and their related features in a low dental disease population. 501 people aged 35-44 years in 16 rural villages in Ban Phang district, Khon Kaen, Thailand, were interviewed about oral impacts on nine physical, psychological and social aspects of performance during the past 6 months, and then had an oral examination. The clinical and behavioural data showed that the sample had low caries (DMFT = 2.7) and a low utilization of dental services. 73.6% of all subjects had at least one daily performance affected by an oral impact. The highest incidence of performances affected were Eating (49.7%), Emotional stability (46.5%) and Smiling (26.1%). Eating, Emotional stability and Cleaning teeth performances had a high frequency or long duration of impacts, but a low severity. The low frequency performances; Physical activities, Major role activity and Sleeping were rated as high severity. Pain and discomfort were mainly perceived as the causes of impacts (40.1%) for almost every performance except Smiling. Toothache was the major causal oral condition (32.7%) of almost all aspects of performance. It was concluded that this low caries people have as high an incidence of oral impacts as industrialized, high dental disease populations. Frequency and severity presented the paradoxical effect on different performances and should both be taken into account for overall estimation of impacts.     

Mitogenic effect of retinoid X receptor agonists in rat liver

Thirty-nine acrylates and methacrylates that had been used in dental resin materials were evaluated by a cytotoxicity test, and the relationships between their structures and cytotoxicity were studied to predict cytotoxic levels of dental resin materials in order to develop new low-toxic resin materials. All the acrylates evaluated were more toxic than corresponding methacrylates. In both the acrylates and methacrylates, a hydroxyl group seemed to enhance cytotoxicity. Dimethacrylates with 14 or fewer oxyethylene chains showed similar cytotoxicity while dimethacrylates with 23 oxyethylene chains showed lower cytotoxicity. The cytotoxicity ranking of monomers widely used in dental resin materials was bisphenol A bis 2-hydroxypropyl methacrylate (bisGMA) > urethane dimethacrylate (UDMA) > triethyleneglycol dimethacrylate (3G) > 2-hydroxyethyl methacrylate (HEMA) > methyl methacrylate (MMA). In acrylates, methacrylates, and ethylmethacrylates with either substituents, the lipophilicity of substituents affected their cytotoxicity, and an inverse correlation between IC50 and logP was observed. These results will be useful in developing new resin materials with low toxic monomer compositions.