Acute nicotine enhances c-fos mRNA expression differentially in reward-related substrates of adolescent and adult rat brain

A number of studies have demonstrated that adolescent rodents are more sensitive to the rewarding effects of nicotine compared to adults. To help determine the potential brain circuitry involved, we investigated the effect of acute nicotine administration (0.4 or 0.8 mg/kg, s.c.) on the expression of c-fos mRNA in the brains of adolescent (P35) and adult (P67-70) male Wistar rats using in situ hybridization. Nicotine administration increased c-fos mRNA expression in several brain regions, including the central amygdala, locus coeruleus, nucleus accumbens core, paraventricular nucleus of the hypothalamus and lateral septum of adolescent and adult rats. Nicotine increased c-fos mRNA expression more robustly in the bed nucleus of the stria terminalis, nucleus accumbens shell and ventral tegmental area in adolescent rats. The current results suggest that nicotine may have greater activational effects in brain regions associated with reward in adolescent rats and may help to explain the differences between adolescents and adults in behavioral responses to nicotine.     

The assessment of cell proliferation during 9,10-dimethyl-1,2-benzanthracene-induced hamster tongue carcinogenesis by means of histone H3 mRNA in situ hybridization

The aim of this study was to investigate cell kinetics and ultrastructural changes during carcinogenesis using a hamster 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced tongue cancer model. Five squamous cell carcinomas, five dysplastic epithelia, seven hyperplastic epithelia, and four normal epithelia were obtained from 21 hamster tongues by applying 1.0% acetone solution of DMBA on the left lingual mucosa after scratching with a root canal broach. Ultrastructural examination revealed that the number of microvilli increased, whereas that of desmosomes decreased during carcinogenesis. Cell proliferation was analyzed by means of 5-bromodeoxyuridine (BrdU) immunohistochemistry and in situ hybridization (ISH) for histone H3 mRNA. The BrdU and histone H3 mRNA labeling indices (LIs) were lowest for normal epithelium, higher for hyperplastic and dysplastic epithelia, and highest for squamous cell carcinoma. Cytoplasmic histone H3 mRNA and nuclear BrdU were localized in virtually identical areas of serial sections. The correlation coefficient for the relationship between these two LIs was 0.97 (P 0.001). These results suggest that the assessment of cell proliferation using H3 mRNA ISH will be a useful technique for investigating biological behavior during carcinogenesis.     

Spatio-temporally differential expression of genes for three members of fatty acid binding proteins in developing and mature rat brains

The chronological changes in the gene expression for three species of cytosolic fatty acid-binding proteins (FABPs) in the rat brain were examined by Northern and in situ hybridization analyses. The expression for heart(H)-FABP became evident after birth, with a gradual increase and confined to the gray matter, suggesting that the expression of H-FABP mRNA is neuron-specific in postnatal brain. The expression for brain(B)-FABP was very intense in the ventricular germinal zone, without expression in the cerebellar external granule cell layer, suggesting the dominant expression in the cells of glial lineage. B-FABP mRNA was transiently expressed in perinatal gray as well as white matter and the expression in glial cells persists only in the olfactory nerve fiber layer at the adult stage. On the other hand, the expression for skin type(S)-FABP was evident in the both ventricular germinal zone and cerebellar external granule cell layer, suggesting the expression in cells of neuronal lineage. The expression for S-FABP was evident in the prenatal gray matter and S-FABP mRNA was expressed in glial cells at early postnatal stage, whereafter the expression decreased to, but remained at weak levels in the adult brain. Discrete functions of the three FABPs were suggested in neurons and glia differentially at various developmental stages.     

High incidence of horse serum protein allergy in various autoimmune disorders.

In 186 persons (68 patients suffering from different so-called autoimmune diseases, 30 kidney recipients, 38 control patients from a surgical ward, and 50 healthy volunteers) the immune response to horse IgG was examined. The lowest rate of sensitization was found in kidney transplant recipients (3%) and the highest in autoimmune patients (33%). After excluding 39 patient who had received horse serum treatment prior to the examination, it was found that without previous injection of horse serum, 27% of the patients with autoimmune disease were sensitized to horse IgG. Compared to the other groups (kidney transplant recipients, 4%: surgical controls, 0%; healthy volunteers, 3%), this difference was statistically significant (p is less than 0.01).     

Inflammatory cytokines in small intestinal mucosa of patients with potential coeliac disease

T helper cell type 1 (Th1) response to gluten has been implicated in the pathogenesis of coeliac disease (CD). To characterize immunological activation and mild inflammations leading to overt CD in potential coeliac patients, jejunal biopsies were obtained from family members of patients with CD or dermatitis herpetiformis (DH). Nine family members and one latent CD, eight CD patients and eight normal controls furnished jejunal biopsy specimens. Immunohistochemical staining of sections for interleukin-1alpha (IL-1alpha), IL-2, IL-4, interferon-gamma (IFN-gamma), tumour necrosis factor alpha (TNF-alpha), CD3, gammadelta-T cell receptor (gammadelta-TCR), and alphabeta-TCR was carried out with monoclonal antibodies. Further, expression of IL-4 and IFN-gamma messenger RNA was detected by radioactive in situ hybridization in these same samples. In lamina propria, CD patients and potential CD patients had higher densities of IL-2 (P = 0.028, P = 0.043), IL-4 (P = 0.021, P = 0.034) and IFN-gamma positive cells (P = 0.000, P = 0.009) than did controls. Moreover, CD patients showed a higher density of TNF-alpha positive cells (P = 0.012, P = 0.001) than the other two groups, and expression of IFN-gamma mRNA (P = 0.035) was higher in them than in the other two study groups. Additionally, higher densities of TNF-alpha and IFN-gamma positive cells occurred in potential CD patients with high gammadelta-TCR+ intraepithelial lymphocytes (IELs). Our findings support the hypothesis that lamina propria T cells and macrophages, through their secretion of cytokines, play a central role in the pathogenesis of coeliac disease. The inflammatory cytokines found in potential CD specimens strongly suggest that these inflammatory markers can be identified long before visible villous changes have occurred.     

Drosophila dSAP18 is a nuclear protein that associates with chromosomes and the nuclear matrix, and interacts with pinin, a protein factor involved in RNA splicing

SAP18 is a highly conserved protein that was proposed to be involved in multiple cellular processes from autophagy to gene regulation and mRNA processing. In this paper we show that, in Drosophila, dSAP18 is a predominantly nuclear protein that associates to both chromosomes and the nuclear matrix. dSAP18 becomes nuclear early during development, at the onset of cellularization, and remains so all through embryo development. dSAP18 is also nuclear in salivary glands, ovaries and cultured S2 cells. Here we also show that dSAP18 forms a complex with the Drosophila homolog of pinin (dPnn), a protein factor involved in mRNA splicing. dSAP18-dPnn interaction was confirmed in vivo, through co-immunoprecipitation experiments, as well as in vitro, through GST pull-down assays. These results are discussed in the context of the possible functions played by SAP18.     

Evidence for interference of vitamin D with PTH/PTHrP receptor expression in opossum kidney cells

 Vitamin D counters the phosphaturic action of parathyroid hormone (PTH) in rats in vivo. The present study was undertaken to examine this interaction using monolayers of Opossum kidney (OK) cells. ³²P uptake, cAMP generation, PTH/PTHrP receptor mRNA expression and intracellular Ca²⁺ [Ca²⁺]_i were measured in (1) control cells, (2) cells exposed to PTH, (3) cells pretreated with 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃], and (4) 1,25(OH)₂D₃-pretreated cells exposed to PTH. ³²P uptakes were in (1) 5.00±0.20 (mean ±SE), in (2) 2.30±0.14 (P<0.001 versus group 1), in (3) 4.80±0.24 (P NS versus group 1) and in (4) 3.70±0.20 (P<0.001 versus group 2) nmol P_i/(mg·prot 10 mm). cAMP levels were in (1) 10±3, in (2) 210±8, in (3) 12±4, and in (4) 122±12 pmol cAMP/mg protein (P<0.001 versus group 2). PTH/PTHrP receptor mRNA expression was in relative units: (1) 100±0, (2) 99.5±6.2, (3) 68.7±2.6 (P<0.001 versus group 1), and (4) 34.8±3.3 (P<0.001 versus group 1). In groups 2 and 4 PTH induced equal transient increments in [Ca²⁺]_i. These experiments demonstrate that the effect of vitamin D on phosphate transport is associated with a commensurate diminution in PTH/PTHrP receptor gene expression and PTH-induced cAMP formation but not with Ca²⁺ transients. Vitamin D per se does not affect ³²P uptake or cAMP generation while it slightly decreased PTH/PTHrP receptor gene expression. These observations demonstrate that: (1) 1.25(OH)₂D₃ directly antagonizes the effects of PTH on ³²P uptake in OK cells, (2) this effect is mediated via inhibition of PTH-induced activation of AC/cAMP system, (3) the diminution in PTH-induced cAMP formation may stem at least in part from a decrease in the expression of PTH/PTHrP receptor mRNA. Received: 2 December 1997 / Received after revision: 19 January 1998 / Accepted: 28 January 1998