Characterization of peroxisome proliferator-activated receptor alpha in normal rat mammary gland and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine-induced mammary gland tumors from rats fed high and low fat diets

Normal Sprague-Dau ley rat mammary gland epithelial cells and mammary gland carcinomas induced by 2-amino-1 -methyl-6-phenylimidazo[4,5-b]pyridine, a carcinogen found in the diet, were examined for the expression of peroxisome proliferator-activated receptor alpha (PPAR alpha). PPAR alpha mRNA and protein was detected in normal and tumor tissue by reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. By quantitative RT-PCR, carcinomas had a 12-fold higher expression than control mammary glands, a statistically significant difference. PPAR alpha expression was examined in carcinomas and normal tissues from rats on high fat (23.5/% corn oil) and low fat (5% corn oil) diets. Although neither carcinomas, nor control tissues showed statistically significant differences between the two diet groups, PPAR alpha expression was the highest in carcinomas from rats on the high fat diet. The expression of PPAR alpha in normal mammary gland and its significant elevation in mammary gland carcinomas raises the possibility of its involvement in mammary gland physiology and pathophysiology. (C) 2000 Published by Elsevier Science Ireland Ltd. All rights reserved.

trans-Cyano(6-methyl-1,4,8,11-tetraazacyclotetradecan-6-amine)cobalt(III) bis(perchlorate) hydrate and trans-hydroxo(6-methyl-1,4,8,11-tetraazacyclotetradecan-6-amine)cobalt(III) bis(perchlorate)

The crystal structures of a pair of closely related macrocyclic cyano- and hydroxopentaaminecobalt(III) complexes, as their perchlorate salts, are reported. Although the two complexes, [Co(CN)(C11H27N5)](ClO4)2.H2O and [Co(OH)(C11H27N5)](ClO4)(2), exhibit similar conformations, significant differences in the Co-N bond lengths arise from the influence of the sixth ligand (cyano as opposed to hydroxo). The ensuing hydrogen-bonding patterns are also distinctly different. Disorder in the perchlorate anions was clearly resolved and this was rationalized on the basis of distinct hydrogen-bonding motifs involving the anion O atoms and the N-H and O-H donors.

2-Methoxy-6-methyl-3-nitro-4-(2-nitroprop-1-enyl)phenyl acetate

In the title compound, C13H14N2O7, steric crowding around the aromatic ring results in significant out-of-plane twisting of the nitro, methoxy, acetoxy and 2-nitropropenyl functional groups. These distortions are explained by comparison with less congested substituted benzene analogues.

Usefulness of a quick decalcification of bone sections embedded in methyl metacrylate: an improved method for immunohistochemistry

Immunohistochemistry of undecalcified bone sections embedded in methyl methacrylate (MMA) is not commonly employed because of potential destruction of tissue antigenicity by highly exothermic polymerization. The aim of the present study was to describe a new technique in which a quick decalcification of bone sections embedded in MMA improves the results for immunohistochemistry. The quality of interleukin 1 alpha (IL-1 alpha) immunostaining according to the present method was better than the conventional one. Immunostaining for osteoprotegerin (OPG) and the receptor activator of NF-kappa B ligand (RANKL) in bone sections of chronic kidney disease patients with mineral bone disorders (CKD-MBD) was stronger than in controls (postmortem healthy subjects). The present study suggested that this method is easy, fast, and effective to perform both histomorphometry and immunohistochemistry in the same bone fragment, yielding new insights into pathophysiological aspects and therapeutic approaches in bone disease.

Role of N-Methyl-D-Aspartate and Non-N-Methyl-D-Aspartate Receptors in the Cardiovascular Effects of L-Glutamate Microinjection Into the Hypothalamic Paraventricular Nucleus of Unanesthetized Rats

We report on the cardiovascular effects of L-glutamate (L-glu) microinjection into the hypothalamic paraventricular nucleus (PVN) as well as the mechanisms involved in their mediation. L-glu microinjection into the PVN caused dose-related pressor and tachycardiac responses in unanesthetized rats. These responses were blocked by intravenous (i.v.) pretreatment with the ganglion blocker pentolinium (PE; 5 mg/kg), suggesting sympathetic mediation. Responses to L-glu were not affected by local microinjection of the selective non-NMDA receptor antagonist NBQX (2 nmol) or by local microinjection of the selective NMDA receptor antagonist LY235959 (LY; 2 nmol). However, the tachycardiac response was changed to a bradycardiac response after treatment with LY235959, suggesting that NMDA receptors are involved in the L-glu heart rate response. Local pretreatment with LY235959 associated with systemic PE or dTyr(CH(2))(5)(Me)AVP (50 mu g/kg) respectively potentiated or blocked the response to L-glu, suggesting that L-glu responses observed after LY235959 are vasopressin mediated. The increased pressor and bradycardiac responses observed after LY + PE was blocked by subsequent i.v. treatment with the V(1)-vasopressin receptor antagonist dTyr(CH(2))(5)(Me)AVP, suggesting vasopressin mediation. The pressor and bradycardiac response to L-glu microinjection into the PVN observed in animals pretreated with LY + PE was progressively inhibited and even blocked by additional pretreatment with increasing doses of NBQX (2, 10, and 20 nmol) microinjected into the PVN, suggesting its mediation by local non-NMDA receptors. In conclusion, results suggest the existence of two glutamatergic pressor pathways in the PVN: one sympathetic pathway that is mediated by NMDA receptors and a vasopressinergic pathway that is mediated by non-NMDA receptors. (C) 2009 Wiley-Liss, Inc.

Non-N-Methyl-D-Aspartate Glutamate Receptors in the Paraventricular Nucleus of Hypothalamus Mediate the Pressor Response Evoked by Noradrenaline Microinjected Into the Lateral Septal Area in Rats

The lateral septal area (LSA) is a part of the limbic system and is involved in cardiovascular modulation. We previously reported that microinjection of noradrenaline (NA) into the LSA of unanesthetized rats caused pressor responses that are mediated by acute vasopressin release. Magnocellular neurons of the paraventricular (PVN) and supraoptic (SON) of the hypothalamus synthesize vasopressin. In the present work, we studied which of these nuclei is involved in the pressor pathway activated by unilateral NA injection into the LSA as well as the local neurotransmitter involved. Chemical ablation of the SON by unilateral injection of the nonspecific synapses blocker cobalt chloride (1 mM/100 nl) did not affect the pressor response evoked by NA (21 nmol/200 nl) microinjection into the LSA. However, the response to NA was blocked when cobalt chloride (1 mM/100 nl) was microinjected into the PVN, indicating that this hypothalamic nucleus is responsible for the mediation of the pressor response. There is evidence in the literature pointing to glutamate as a putative neurotransmitter activating magnocellular neurons. Pretreatment of the PVN with the selective non-N-methyl-D-asparate (NMDA) antagonist NBQX (2 nmol/100 nl) blocked the pressor response to NA microinjected into the LSA, whereas pretreatment with the selective NMDA antagonist LY235959 (2 nmol/100 nl) did not affect the response to NA. Our results implicate the PVN as the final structure in the pressor pathway activated by the microinjection of NA into the LSA. They also indicate that local glutamatergic synapses and non-NMDA glutamatergic receptors mediate the response in the PVN. (c) 2008 Wiley-Liss, Inc.

N-Methyl-D-aspartate glutamate receptors in the hypothalamic paraventricular nucleus modulate cardiac component of the baroreflex in unanesthetized rats

In the present study, we investigated the role played by the hypothalamic paraventricular nucleus (PVN) in the modulation of cardiac baroreflex activity in unanesthetized rats. Bilateral microinjections of the nonselective neurotransmission blocker CoCl(2) into the PVN decreased the reflex bradycardic response evoked by blood pressure increases, but had no effect on reflex tachycardia evoked by blood pressure decreases. Bilateral microinjections of the selective NMDA glutamate receptor antagonist LY235959 into the PVN caused effects that were similar to those observed after microinjections of CoCl(2), decreasing reflex bradycardia without affecting tachycardic response. The microinjection of the selective non-NMDA glutamate receptor antagonist NBQX into the PVN did not affect the baroreflex activity. Also, the microinjection of L-glutamate into the PVN increased the reflex bradycardia, an effect opposed to that observed after PVN treatment with CoCl(2) or LY235959, and this effect of L-glutamate was blocked by PVN pretreatment with LY235959. LY235959 injected into the PVN after iv. treatment with the selective beta(1)-adrenoceptor antagonist atenolol still decreased the reflex bradycardia. Taken together, our results suggest a facilitatory influence of the PVN on the bradycardic response of the baroreflex through activation of local NMDA glutamate receptors and a modulation of the cardiac parasympathetic activity. (C) 2010 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Non-N-methyl-d-aspartate glutamate receptors in the lateral hypothalamus modulate cardiac baroreflex responses in conscious rats

P>In the present study, we investigated the effects of inhibition of the lateral hypothalamus (LH) neurotransmission with bilateral microinjection of CoCl(2), a non-selective blocker of neurotransmission, on modulation of cardiac baroreflex responses in conscious rats as well as the involvement of LH glutamatergic neurotransmission in this modulation. Reflex bradycardiac and tachycardiac responses to blood pressure increases (following i.v. infusion of phenylephrine) or decreases (following i.v. infusion of sodium nitroprusside) were investigated in conscious male Wistar rats. Responses were evaluated before and after microinjection of 1 nmol/100 nL CoCl(2), 2 nmol/100 nL 1,2,3,4-tetrahydro-6-nitro-2,3-dioxobenzoquinoxaline-7-sulphonamide (NBQX; a selective non-N-methyl-d-aspartate (NMDA) glutamate receptor antagonist) or different doses (2, 4 or 8 nmol/100 nL) of the selective NMDA glutamate receptor antagonist LY235959. Microinjection of CoCl(2) into the LH had no effect on the tachycardiac baroreflex response, but did evoke a decrease in the reflex bradycardia caused by increases in blood pressure. Microinjection of NBQX into the LH had a similar effect on reflex bradycardia as CoCl(2), but had no effect on the tachycardiac response. Microinjection of increasing doses of LY235959 into the LH had no effect on the cardiac baroreflex response. In conclusion, the data suggest that the LH has a tonic facilitatory influence on the parasympathetic component of the baroreflex. The results also indicate that this facilitatory influence is mediated by local LH glutamatergic neurotransmission through non-NMDA glutamatergic receptors.

Involvement of hypothalamic paraventricular nucleus non-N-methyl-d-aspartate receptors in the pressor response to noradrenaline microinjected into the bed nucleus of the stria terminalis of unanesthetized rats

Microinjection of noradrenaline into the bed nucleus of the stria terminalis (BST) has been reported to cause a pressor response in unanesthetized rats, which was shown to be mediated by acute vasopressin release into the systemic circulation. In the present study we verified the involvement of magnocellular neurons of the hypothalamic paraventricular (PVN) or supraoptic (SON) nuclei and the local neurotransmitter involved in the pressor response to noradrenaline microinjection into the BST. The PVN pretreatment with the non-selective neurotransmission blocker CoCl(2) (1 nmol/100 nL) inhibited the noradrenaline-evoked pressor response. However, responses were not affected by SON treatment with CoCl(2). Further experiments were carried out to test if glutamatergic neurotransmission in the PVN mediates the pressor response evoked by noradrenaline microinjection into the BST. Pretreatment of the PVN with the selective N-methyl-d-aspartate (NMDA) receptor antagonist LY235959 (2 nmol/100 nL) did not affect the noradrenaline-evoked pressor response. However, PVN pretreatment with the selective non-NMDA receptor antagonist NBQX (2 nmol/100 nL) significantly reduced the pressor response to noradrenaline microinjection into the BST. In conclusion, our results suggest that pressor responses to noradrenaline microinjection into the BST are mediated by PVN magnocellular neurons without involvement of SON neurons. They also suggest that a glutamatergic neurotransmission through non-NMDA glutamate receptors in the PVN mediates the response.

Farnesoic acid O-methyl transferase (FAMeT) isoforms: Conserved traits and gene expression patterns related to caste differentiation in the stingless bee, Melipona scutellaris

Farnesoic acid O-methyl transferase (FAMeT) is the enzyme that catalyzes the formation of methyl farnesoate (MF) from farnesoic acid (FA) in the biosynthetic pathway of juvenile hormone (JH). This work reports the cloning, sequencing, and expression of FAMeT gene from the stingless bee Melipona scutellaris (MsFAMeT). The MsFAMeT in silica analysis showed that greatest sequence similarity is found in Apis mellifera and other insects, while relatively less similarity is shown in crustaceans. Evidence of alternative splicing of a 27 nucleotide (nt) microexon explains the presence of the detected isoforms, 1 and 2. The expression analysis of the two isoforms showed a marked difference when castes were compared, suggesting that they could be involved differently in the JH metabolism in M. scutellaris, providing new insights for the comprehension of female plasticity.

Single Intranasal Administration of 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine in C57BL/6 Mice Models Early Preclinical Phase of Parkinson`s Disease

Many studies have shown that deficits in olfactory and cognitive functions precede the classical motor symptoms seen in Parkinson`s disease (PD) and that olfactory testing may contribute to the early diagnosis of this disorder. Although the primary cause of PD is still unknown, epidemiological studies have revealed that its incidence is increased in consequence of exposure to certain environmental toxins. In this study, most of the impairments presented by C57BL/6 mice infused with a single intranasal (i.n.) administration of the proneurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) (1 mg/nostril) were similar to those observed during the early phase of PD, when a moderate loss of nigral dopamine neurons results in olfactory and memory deficits with no major motor impairments. Such infusion decreased the levels of the enzyme tyrosine hydroxylase in the olfactory bulb, striatum, and substantia nigra by means of apoptotic mechanisms, reducing dopamine concentration in different brain structures such as olfactory bulb, striatum, and prefrontal cortex, but not in the hippocampus. These findings reinforce the notion that the olfactory system represents a particularly sensitive route for the transport of neurotoxins into the central nervous system that may be related to the etiology of PD. These results also provide new insights in experimental models of PD, indicating that the i.n. administration of MPTP represents a valuable mouse model for the study of the early stages of PD and for testing new therapeutic strategies to restore sensorial and cognitive processes in PD.

Effect of methyl methacrylate monomer on bond strength of denture base resin to acrylic teeth

Bond failures at the acrylic teeth and denture base resin interface are still a common clinical problem in prosthodontics. The effect of methyl methacrylate (MMA) monomer on the bond strength of three types of denture base resins (Acron MC, Lucitone 550 and QC-20) to two types of acrylic teeth (Biotone and Trilux) was evaluated. Twenty specimens were produced for each denture base resin/acrylic tooth combination and were randomly divided into control (acrylic teeth received no surface treatment) and experimental groups (MMA was applied to the surface of the acrylic teeth for 180 s) and were submitted to shear tests (1 mm/mm). Data (MPa) were analyzed using three-way ANOVA/Student`s test (alpha = 0.05). MMA increased the bond strength of Lucitone denture base resins and decreased the bond strength of QC-20. No difference was detected for the bond strength of Acron MC base resin after treatment with MMA. (C) 2008 Elsevier Ltd. All rights reserved.

Free radical copolymerization of methyl methacrylate and allyl acetate Part 2 structure and properties

The structure of the product from the free radical bulk copolymerization of methyl methacrylate (MMA) and allyl acetate (AAc) was investigated. The mole fraction of AAc plays an important role in the copolymerization of these two monomers. Molecular weight (MW) and molecular weight distribution (MWD) are completely altered when the feed composition is dominantly AAc. NMR spectroscopy confirmed the incorporation of AAc into the polymer. However, no allyl-allyl linkages were observed at low conversions. T-g was found to be affected by the incorporation of AAc into the polymer. (C) 2001 Society of Chemical Industry.