Interleukin-1 inhibits renin gene expression in As4.1 cells but not in native juxtaglomerular cells

The assessment of personality disorders is complicated by conceptual and empirical problems. An aspect of the disarray in this area is the general negative connotations associated with these conditions, which is prevalent in the negative language frequently used to describe these disorders. This article presents a simple, straightforward, and objective approach to evaluating and describing the Axis II conditions as an example of how to improve on this problem.     

Induction of cyclooxygenase (COX)-2 but not COX-1 gene expression in apoptotic cell death

In this study we assessed the regulation of cyclooxygenase (COX)-2 in models of apoptotic cell death in vivo and in vitro. By 6 h after hippocampal colchicine injection in rat, COX-2 (but not COX-1) mRNA expression was elevated. The induction of COX-2 mRNA expression preceded temporally and overlapped anatomically the cellular morphological features of apoptosis in the granule cell layer of the dentate gyrus. Similarly, in an established in vitro model of apoptosis in P19 cells, COX-2 induction preceded apoptosis in response to serum deprivation by 12 h. These studies suggest that COX-2 may be involved in the early mechanisms leading to apoptosis.     

Transfection of the gene for B7-1 but not B7-2 can induce immunity to murine malignant mesothelioma

A 56-year-old female with rheumatoid arthritis was admitted because of bilateral hip pain. In a few months of her hospitalization, a relatively abrupt renal dysfunction was emerged besides complement breakdown, and renal biopsy revealed crescentic glomerulonephritis. Immunofluorescence study showed peripheral granular deposits of IgG, IgM, and C3 in the glomeruli. Cresents were predominantly composed of macrophages and glomerular epithelial cells. Amyloid nephropathy, renal vasuculitis, and association of other collagen vascular diseases were negligible for the causative factor. It was suggested that immune complexes were formed in the glomeruli, in which both humoral and cellular immune responses were to be induced, that brought cescents formation in the lesions. Crescentic glomerulonephritis in patients with rheumatoid arthritis is rare and a possible pathogenetic mechanisms involved in the development of renal dysfunction are discussed with the special reference to immune complex-induced inflammation.     

Estrogen regulates galanin but not tyrosine hydroxylase gene expression in the rat locus ceruleus

The neuropeptide galanin (GAL) is coexpressed by the majority of noradrenergic neurons in the rat locus ceruleus (LC) and may function as an inhibitory modulator of noradrenergic transmission. Because estrogen has been shown to induce GAL expression in other brain regions and modulate noradrenergic transmission, we used in situ hybridization histochemistry to assess the effects of chronic estrogen treatment on GAL and tyrosine hydroxylase (TH) gene expression in the LC of ovariectomized female rats. We found that GAL mRNA levels were significantly elevated in rats implanted with a Silastic capsule containing estradiol compared to sham-implanted controls. Both the average optical density (P < or = 0.05) and the labelling area (P < or = 0.007) differed significantly between the groups. In contrast, TH gene expression measured in alternate brain sections did not differ between the groups. If GAL functions as an inhibitory modulator of noradrenergic transmission as postulated, these findings suggest that chronic estrogen treatment could reduce the noradrenergic tone of the brain in the absence of significant alterations in TH expression by enhancing the level of cosecreted GAL.     

Homologous pairing is reduced but not abolished in asynaptic mutants of yeast

In situ hybridization was used to examine chromosome behavior at meiotic prophase in the rad50S, hop1, rad50, and spo11 mutants of Saccharomyces cerevisiae, which are defective in chromosome synapsis and meiotic recombination. Painting of chromosomes I and III revealed that chromosome condensation and pairing are reduced in these mutants. However, there is some residual pairing in meiosis, suggesting that homologue recognition is independent of synaptonemal complex formation and recombination. Association of homologues was observed in the rad50, rad50S, and spo11 mutants, which are defective in the formation or processing of meiotic double-strand breaks. This indicates that double-strand breaks are not an essential component of the meiotic homology searching mechanism or that there exist additional or alternative mechanisms for locating homologues.     

Recombinase activating gene expression in thymic subpopulations. A transitional cell type has lost RAG-2 but not RAG-1

We have used a highly sensitive Northern blot probing technique to examine RAG-1 and RAG-2 mRNA expression in unmanipulated murine thymocytes of various developmental phenotypes sorted by flow cytometry. We have found that neither RAG-1 nor RAG-2 are down-regulated until thymocytes reach the TCRhi stage. TCRhi, CD8+CD4+ cells have lost RAG-2 mRNA but continue to express significant levels of RAG-1 mRNA, providing molecular evidence that this cell type is transitional between the TCRlo, CD4+CD8+ and the TCRhi, CD4+CD8-, or CD4-CD8+ phenotypes.     

Drosophila engrailed can substitute for mouse Engrailed1 function in mid-hindbrain, but not limb development

The Engrailed-1 gene, En1, a murine homologue of the Drosophila homeobox gene engrailed (en), is required for midbrain and cerebellum development and dorsal/ventral patterning of the limbs. In Drosophila, en is involved in regulating a number of key patterning processes including segmentation of the epidermis. An important question is whether, during evolution, the biochemical properties of En proteins have been conserved, revealing a common underlying molecular mechanism to their diverse developmental activities. To address this question, we have replaced the coding sequences of En1 with Drosophila en. Mice expressing Drosophila en in place of En1 have a near complete rescue of the lethal En1 mutant brain defect and most skeletal abnormalities. In contrast, expression of Drosophila en in the embryonic limbs of En1 mutants does not lead to repression of Wnt7a in the embryonic ventral ectoderm or full rescue of the embryonic dorsal/ventral patterning defects. Furthermore, neither En2 nor en rescue the postnatal limb abnormalities that develop in rare En1 null mutants that survive. These studies demonstrate that the biochemical activity utilized in mouse to mediate brain development has been retained by Engrailed proteins across the phyla, and indicate that during evolution vertebrate En proteins have acquired two unique functions during embryonic and postnatal limb development and that only En1 can function postnatally.     

Pre-mRNA processing enhancer (PPE) element increases the expression of an intronless thymidylate synthase gene but does not affect intron-dependent S phase regulation

Maternal smoking during pregnancy causes reduction of fetal breathing movements, an effect attributed to nicotine in fetal blood. Nicotine is metabolized to cotinine which has a long plasma half-life and exhibits slow clearance across membrane barriers. It is also known to activate placental phospholipase-A2-like enzymes, resulting in formation of prostaglandins. Therefore, we studied transport of nicotine in isolated perfused cotyledon of normal human term placenta. The placental cotyledon was perfused with aerated (21% O2, 5% CO2) Krebs-Ringer bicarbonate buffer (pH 7.4, 37 degrees C) containing 2% albumin on both maternal (230 ml, 15 ml/min, 35 mm Hg) and fetal (93 ml, 1.75 ml/min, 70 mm Hg) sides in a closed recirculating system. Nicotine (2 mg) was added to the maternal perfusate; perfusate samples (1 ml) were collected from both sides at regular intervals and analyzed for nicotine and cotinine by high-pressure liquid chromatography. This study gave the following results: (1) In about 60-80 min, 18.6% of the nicotine added to the maternal perfusate was transferred to the fetal perfusate, and the maternal/fetal concentration ratio reached 1.0. These results show rapid placental transfer of nicotine, consistent with its high lipid solubility. (2) Less than 1% is metabolized to cotinine in placenta. The ratio of cotinine concentrations in maternal and fetal perfusates reached 1.0 in about 40 min. These studies were also verified using 14C-nicotine. (3) Maximal reduction in fetal breathing movements occurs at about 30 min, and recovery occurs at 90 min after tobacco smoking by the mother. These observations agree with the rate of placental transfer of nicotine. (4) When nicotine was added on the fetal side, part of it was metabolized to cotinine. However, the maximal concentration of cotinine was twice higher on fetal than on maternal side. These observations suggest that accumulation of cotinine on fetal side may activate prostaglandin formation and trigger spontaneous abortions in pregnant smokers.     

Widespread expression of an autoantigen-GAD65 transgene does not tolerize non-obese diabetic mice and can exacerbate disease

Glutamic acid decarboxylase (GAD)65 is a pancreatic beta cell autoantigen implicated as a target of T cells that initiate and sustain insulin-dependent diabetes mellitus (IDDM) in humans and in non-obese diabetic (NOD) mice. In an attempt to establish immunological tolerance toward GAD65 in NOD mice, and thereby to test the importance of GAD in IDDM, we generated three lines transgenic for murine GAD65 driven by a major histocompatibility complex class I promoter. However, despite widespread transgene expression in both newborn and adult mice, T cell tolerance was not induced. Mononuclear cell infiltration of the islets (insulitis) and diabetes were at least as bad in transgenic mice as in nontransgenic NOD mice, and in mice with the highest level of GAD65 expression, disease was exacerbated. In contrast, the same transgene introduced into mouse strain, FvB, induced neither insulitis nor diabetes, and T cells were tolerant to GAD. Thus, the failure of NOD mice to develop tolerance toward GAD65 reflects at minimum a basic defect in central tolerance, not seen in animals not predisposed to IDDM. Hence, it may not be possible experimentally to induce full tolerance toward GAD65 in prediabetic individuals. Additionally, the fact that autoimmune infiltration in GAD65 transgenic NOD mice remained largely restricted to the pancreas, indicates that the organ-specificity of autoimmune disease is dictated by tissue-specific factors in addition to those directing autoantigen expression.     

CD44 expression is aberrant in benign Schwann cell tumors possessing mutations in the neurofibromatosis type 2, but not type 1, gene

Atypical expression of CD44 splice variants has been implicated in the progression of numerous tumors. This abnormal CD44 expression is presumed to result from gene alterations that cause tumorigenic transformation. Two tumor types that have been linked to specific gene alterations are schwannomas, which have mutations in the neurofibromatosis (NF) type 2 (NF2) gene, and neurofibromas, which characteristically possess NF type 1 (NF1) gene mutations. We examined CD44 expression in normal sciatic nerves, in schwannomas with confirmed NF2 mutations, and in neurofibromas and malignant peripheral nerve sheath tumor tissue and cell lines from NF1 patients. Compared to normal nerves, schwannomas express higher total levels of CD44 and additional splice variants, whereas CD44 expression in neurofibromas is unaltered. Malignant peripheral nerve sheath tumor tissue and cell lines express the CD44v6 epitope, which is not expressed by normal Schwann cells or by other Schwann cell tumors. These data indicate that altered CD44 expression correlates strictly with mutations in the NF2 but not NF1 gene and suggest that CD44v6 might be a marker for the malignant transformation of Schwann cells.     

TAG-1 can mediate homophilic binding, but neurite outgrowth on TAG-1 requires an L1-like molecule and beta 1 integrins

Subsets of axons in the embryonic nervous system transiently express the glycoprotein TAG-1, a member of the subfamily of immunoglobulin (Ig)-like proteins that contain both C2 class Ig and fibronectin type III domains. TAG-1 is attached to the cell surface by a glycosylphosphatidylinositol linkage and is secreted by neurons. In vitro studies have shown that substrate-bound TAG-1 promotes neurite outgrowth. We have examined the nature of axonal receptors that mediate the neurite-outgrowth promoting properties of TAG-1. Although TAG-1 can mediate homophilic binding, neurite outgrowth on a substrate of TAG-1 does not depend on the presence of TAG-1 on the axonal surface. Instead, neurite outgrowth on TAG-1 is inhibited by polyclonal antibodies directed against L1 and, independently, by polyclonal and monoclonal antibodies against beta 1-containing integrins. These results provide evidence that TAG-1 can interact with cell surfaces in both a homophilic and heterophilic manner and suggest that neurite extension on TAG-1 requires the function of both integrins and an L1-like molecule.     

Obese gene expression in porcine adipose tissue is reduced by food deprivation but not by maintenance or submaintenance intake

The wide distribution of corticotropin-releasing factor (CRF) and substance P (SP)-immunoreactive cell bodies, nerve terminals and corresponding receptors in pressor nuclei controlling emotion and stress implies that CRF and SP may play important roles in pressor responses of these nuclei; hence CRF or SP was microinjected into these nuclei respectively in Wistar male rats anesthetized with urethane to test this possibility. Microinjection of CRF into nucleus amygdaloideus centralis, nucleus paraventricularis, nucleus ventromedialis, lateral hypothalamus-perifornical region, periaqueductal gray matter, nucleus parabrachialis, locus coeruleus or rostral ventrolateral medulla respectively could evoke pressor responses (but CRF injection into nucleus dorsomedialis could not elicit significant pressor responses). Injection of substance P into all the above nuclei could also elicit hypertensive responses of different magnitudes, whereas normal saline injection into these nuclei had no effect. These results indicate that both CRF and SP in the above mentioned nuclei may play important roles in hypertension induced by prolonged emotional stress.     

Clonidine blocks acquisition but not expression of conditioned opiate withdrawal in rats

Previous studies in rodents have reported that clonidine, an alpha 2-adrenergic receptor agonist, attenuated conditioned aversions to naloxone-precipitated opiate withdrawal when administered prior to each withdrawal conditioning episode. The current study was designed to determine whether clonidine could modify the expression of previously established conditioned place aversions and conditioned suppression of operant responding. Dose- and time-dependent effects of clonidine on activity and suppression of operant responding for food identified appropriate treatment parameters for subsequent studies in which rats rendered dependent on opiates through implantation of morphine pellets were tested for: (1) conditioned place aversion; and (2) conditioned suppression of operant responding for food (fixed ratio-15 schedule), in a paradigm wherein rats received four pairings of naloxone with a distinct tone and odor stimulus. Clonidine dose-dependently blocked the acquisition of both conditioned behaviors when administered prior to naloxone on each conditioning trial, but was ineffective in blocking the expression of these conditioned withdrawal signs when administered prior to the test session.