RESUMO
Objective: To determine the effects of menopausal stage, age and other associated risk factors on symptoms of anxiety and depression among women in a community in Beijing. Methods: This study was a community-based prospective cohort. Participants who had transitioned through natural menopause, completed two or more depressive and anxiety symptoms evaluations, aged 35 to 64 years, and did not use hormone therapy were selected from the Peking Union Medical College Hospital aging longitudinal cohort of women in midlife to this analysis. The primary outcome variables were depressive and anxiety symptoms, assessed by hospital anxiety and depression scale (HADS). The generalized estimation equation was used in the statistical analysis. Results: Followed up from 2006 to 2014, 430 women and 2 533 HADS assessments were retained in the cohort. Depressive symptoms were more common than anxiety symptoms during all menopausal stages. The incidences of depressive and anxiety symptoms were 14.5% (19/191) and 3.1% (4/191) in the premenopausal -3 stage, respectively. The incidence increased in both menopausal transition and postmenopausal stage, with the highest incidence in the +1c stage [20.6% (155/751) and 8.8% (66/751), respectively]. However, these differences were not statistically significant (all P>0.05). Depressive symptoms were highest in the ≥60-<65 age group [20.8% (74/355)], and anxiety symptoms were highest in the ≥50-<55 age group [8.2% (62/754)]; but there were no statistical significances between different age groups and depressive and anxiety symptoms (all P>0.05). Multivariable analysis showed that high body mass index, low education status, and poor health status were independently associated with depressive symptoms (all P<0.05), and that poor health status, trouble falling asleep, and early awakening were independently associated with anxiety symptoms (all P<0.01). Conclusions: Depressive and anxiety symptoms are more common during menopausal transition and postmenopausal stage compared with reproductive stage. Depressive symptoms are more common than anxiety symptoms. To screen and assess depressive and anxiety symptoms in perimenopausal women is essential, especially for women with high risk factors.
Assuntos
Depressão , Menopausa , Ansiedade/epidemiologia , Pequim/epidemiologia , Depressão/diagnóstico , Depressão/epidemiologia , Feminino , Humanos , Pessoa de Meia-Idade , Estudos ProspectivosAssuntos
Implante Coclear , Perda Auditiva Central/genética , Perda Auditiva Central/cirurgia , Perda Auditiva Neurossensorial/cirurgia , Proteínas de Membrana/genética , Mutação/genética , Fatores Etários , Pré-Escolar , Implantes Cocleares , Estudos de Coortes , Potenciais Evocados Auditivos do Tronco Encefálico , Feminino , Perda Auditiva Neurossensorial/genética , Humanos , Masculino , Fatores de TempoRESUMO
Objective:To investigate the clinical characteristics, family history, treatment and prognosis of patients with Crouzon syndrome. Method:We reviewed and analyzed the clinical data of 6 patients with Crouzon syndrome. All patients suffered from snore during sleep, along with mouth opening, in which 5 cases had apnea and could be awaken. In addition, five of six experienced hearing loss, including one case with right ear discharging repeatedly. During the treatment, all patients were operated under general anesthesia. Among six cases, two were performed by tonsillectomy, adenoidectomy, and myringotomy; one was treated by adenoidectomy and myringotomy; two were performed by adenoidectomy; one was treated by external auditory canal cholesteatoma exenteration. Result:Within half a year to seven years' follow-up, 5 patients snore occasionally at night but without sleep apnea, while 1 patient performed by external auditory canal cholesteatoma exenteration has no improvement in sleep snoring. Additionally, the hearing of 5 patients have been greatly improved after operation and the cranial facial deformity of 2 cases have been alleviated than before, while 4 patients have no alleviation in oxycephaly, exophthalmos, mandibular prognathism and malocclusion.Conclusion:Understanding the clinical characteristics of Crouzon syndrome significantly contributes to early diagnosis of this disease. Individual-based treatment should be carried out according to the clinical symptoms and signs of patients. Early intervention benefit to the improvement of prognosis and the life quality of patients.
Assuntos
Adenoidectomia , Disostose Craniofacial/cirurgia , Ronco/complicações , Tonsilectomia , Disostose Craniofacial/diagnóstico , Humanos , Prognóstico , Resultado do TratamentoRESUMO
Cobrotoxin produces intense analgesia but it has an onset of response of 1-3 h which hampers its clinical use in cancer pain. Recently, a compound analgesic formulation combining cobrotoxin, tramadol hydrochloride and ibuprofen (Compound Keluoqu, CKLQ) has become available in China. The aim of this study was to evaluate the clinical efficacy of CKLQ for moderate to severe cancer pain. A consecutive series of patients with chronic moderate to severe cancer pain was enrolled into two multicenter trials. Of the 230 eligible patients, 119 were assigned to a randomized, double-blind, cross-over study, while 111 entered an open-label study. They were all of Han-China nationality and had a mean age of 52.0 and 55.4 years and a mean body weight of 55.6 and 52.9 kg, respectively. A total of 11 patients discontinued the study, 6 (54.5%) because of insufficient pain relief and 5 due to the occurrence of adverse events. In the cross-over study, 59 patients were randomized to receive a CKLQ package with 2 CKLQ tablets (each containing 0.16 mg cobrotoxin, 25 mg tramadol hydrochloride and 50 mg ibuprofen) and 2 placebo capsules, a placebo package with 2 placebo tablets and 2 placebo capsules, and an active control package with 2 tramadol hydrochloride capsules (each containing 50 mg tramadol hydrochloride) and 2 placebo tablets (arm A), and 60 to receive a tramadol hydrochloride package, a placebo package and a CKLQ package (arm B), sequentially and only once. Patients in the open-label study only received CKLQ and were given the option to continue for up to 7 days as long as they had satisfactory pain relief. Pain response was classified as CR, PR and NC. CR was defined as 100% pain relief, with a pain score of 0 on a 0-10 VAS. PR was defined as decreased to mild pain, with a pain score of no more than 4 on a 0-10 VAS. NC was defined as pain that either remained unchanged or that was reduced from severe to moderate at baseline, with a VAS pain score of more than 4 after treatment. One hundred and eight patients completed the cross-over study with all the three drug units. The overall rate of pain relief was 93/111 (83.7%) for CKLQ, 75/110 (68.2%) for tramadol hydrochloride (P=0.011) and 39/111 (35.1%) for placebo (P<0.001). The mean duration of pain relief with CKLQ was significantly longer than that of the other two agents (P<0.001). Of the 35 patients who did not respond to tramadol hydrochloride, 27 (77.1%) responded to CKLQ, while of the 18 who did not respond to CKLQ, 8 (55.6%) achieved satisfactory pain control with tramadol hydrochloride. In the open-label study, the overall relief rate of a single-dose of CKLQ was 99/111 (89.2%). A reduction in the percentage of complete relief, an increase in that of PR and a significant decrease in duration of relief were observed after continuous treatment with at least 10 doses of CKLQ. The frequency of adverse events for CKLQ was similar to that of tramadol hydrochloride. The results of the randomized, double-blind, cross-over study and the open-label study of CKLQ in cancer patients with chronic moderate to severe cancer pain suggest that the CKLQ may be valuable for the treatment of chronic moderate to severe cancer pain. However, the tolerance of CKLQ remains to be further defined.
Assuntos
Analgésicos/administração & dosagem , Proteínas Neurotóxicas de Elapídeos/administração & dosagem , Ibuprofeno/administração & dosagem , Neoplasias/complicações , Dor/tratamento farmacológico , Tramadol/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Cross-Over , Método Duplo-Cego , Combinação de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/etiologiaRESUMO
Two hormone-dependent mammary carcinomas regressing after hormone removal, [one primary 7,12-dimethylbenz(alpha)-anthracene induced, and the other transplanted MTW9] were used as models to test the hypothesis that the regression of hormone-dependent mammary tumors is triggered by a modification of the genetic expression. In support of the hypothesis, we observed that: (1) the in vitro translation products of poly(A)+ RNAs differ between growing and regressing tumors; (b) the difference is localized in four protein bands (mr 53,000, 35,000, 22,000 and 20,000) of the electrophoretic pattern that decrease in their concentrations and one protein band (Mr 20,500) that increases during regression; (c) the changes in the translation products occur within 6 hr post-hormone removal, and the changes are reversed when resumption of tumor growth was induced by replenishment of the hormone to the host rats: and (d) three autonomously growing tumors exhibit a unique translation pattern which differs from that of hormone-dependent tumors, and the pattern does not change upon hormone removal. The results suggest that hormonal regulation of mammary tumor growth is related to specific genetic transcripts, and loss of hormone dependence of growth may correlate with the changes in this genetic control.
Assuntos
Regulação da Expressão Gênica , Neoplasias Hormônio-Dependentes/genética , 9,10-Dimetil-1,2-benzantraceno , Animais , Castração , Eletroforese em Gel de Poliacrilamida , Estrogênios/farmacologia , Feminino , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/patologia , Peso Molecular , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/isolamento & purificação , Transplante de Neoplasias , Neoplasias Hormônio-Dependentes/patologia , Biossíntese de Proteínas , RNA Neoplásico/isolamento & purificação , Ratos , Ratos Endogâmicos , Transcrição GênicaRESUMO
Carcinogenic doses of 7,12-dimethylbenz(alpha)anthracene (DMBA) failed to induce mammary carcinoma in the rats that have received N6,O2'-dibutyryl cyclic adenosine 3',5'-monophosphate (DBcAMP) (Cancer Res., 43: 2736, 1983). We now report that the anticarcinogenic effect of DBcAMP correlates with its effect on DNA binding of the carcinogen and on gene expression. Cultured mammary epithelial cells in exponential phase of growth were used to determine the effect of DBcAMP on DMBA binding to DNA. DBcAMP inhibited the DMBA binding in carcinogen-susceptible mammary cells of 50-day-old rats, but it had no effect on the binding in the DMBA-resistant mammary cells of 35- and 110-day-old rats. The inhibitory effect of DBcAMP was appreciable at the concentration of 10(-7) M, one tenth the concentration of [3H]DMBA. DBcAMP at 10(-6) M concentration exhibited the maximal inhibition of DMBA binding; i.e., binding in DMBA-susceptible mammary cells was reduced to the level of binding observed in DMBA-resistant mammary cells. Polyadenylate-containing RNAs isolated from mammary glands of DMBA-susceptible rats (50-day-old) yielded translation products in vitro which bear a greater resemblance to translation products of growing DMBA-induced tumors than they do to products of messenger RNAs from regressing tumors or DMBA-resistant mammary glands of 110-day-old rats. DBcAMP administered to the susceptible rats resulted in changes in the translation products of the mammary glands; the translation products of the glands became similar to those of DMBA-resistant mammary glands or regressing tumors. DMBA feeding 1 day after DBcAMP treatment could not reverse this effect of DBcAMP. These data suggest that the role of cyclic adenosine 3',5'-monophosphate at the genomic level is responsible for the anticarcinogenesis of mammary cells.
Assuntos
9,10-Dimetil-1,2-benzantraceno/metabolismo , Antineoplásicos , Benzo(a)Antracenos/metabolismo , Bucladesina/uso terapêutico , DNA/metabolismo , Glândulas Mamárias Animais/metabolismo , Transcrição Gênica/efeitos dos fármacos , Animais , Bucladesina/farmacologia , Epitélio/metabolismo , Feminino , Cinética , Glândulas Mamárias Animais/efeitos dos fármacos , RNA Mensageiro/genética , Ratos , Ratos EndogâmicosRESUMO
The primary goal of this research is to develop a three-term mesoscopic reaction rate model that consists of a hot-spot ignition, a low-pressure slow burning and a high-pressure fast reaction terms for shock initiation of multi-component Plastic Bonded Explosives (PBX). Thereinto, based on the DZK hot-spot model for a single-component PBX explosive, the hot-spot ignition term as well as its reaction rate is obtained through a "mixing rule" of the explosive components; new expressions for both the low-pressure slow burning term and the high-pressure fast reaction term are also obtained by establishing the relationships between the reaction rate of the multi-component PBX explosive and that of its explosive components, based on the low-pressure slow burning term and the high-pressure fast reaction term of a mesoscopic reaction rate model. Furthermore, for verification, the new reaction rate model is incorporated into the DYNA2D code to simulate numerically the shock initiation process of the PBXC03 and the PBXC10 multi-component PBX explosives, and the numerical results of the pressure histories at different Lagrange locations in explosive are found to be in good agreements with previous experimental data.
RESUMO
Cholangiocarcinoma (CCA) continues to harbor a difficult prognosis and it is difficult to diagnose in its early stages. The molecular mechanisms of CCA oncogenesis and progression are poorly understood. This study aimed to identify candidate biomarkers for CCA. Integrated analysis of microarray data sets was performed to identify differentially expressed genes (DEGs) between CCA and normal tissues. Gene Ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were then performed to identify the functions of DEGs. Furthermore, the protein-protein interaction (PPI) network of DEGs was constructed. The expressions of DEGs were validated in human CCA tissues by qRT-PCR. A set of 712 DEGs were identified in CCA compared with normal tissues, including 306 upregulated and 406 downregulated DEGs. It can be shown from the KEGG pathway analysis that some pathways may have important roles in pathology of CCA, including peroxisome proliferator-activated receptor signaling pathway, bile secretion, cell cycle, fat digestion and absorption. PPI network indicated that the significant hub proteins were PKM, SPP1 and TPM1. The abnormally overexpression PKM, SPP1 and TPM1 were closely related to oncogenesis and progression of CCA. PKM, SPP1, TPM1, COL1A1 and COL1A2 may serve as candidate biomarkers for diagnosis and prognosis of CCA.
Assuntos
Neoplasias dos Ductos Biliares/diagnóstico , Biomarcadores Tumorais/genética , Colangiocarcinoma/diagnóstico , Mapas de Interação de Proteínas/genética , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/patologia , Carcinogênese/genética , Proteínas de Transporte/genética , Ciclo Celular/genética , Células Cultivadas , Colangiocarcinoma/genética , Colangiocarcinoma/patologia , Colágeno Tipo I/genética , Cadeia alfa 1 do Colágeno Tipo I , Conjuntos de Dados como Assunto , Regulação para Baixo , Perfilação da Expressão Gênica , Humanos , Proteínas de Membrana/genética , Análise em Microsséries , Osteopontina/genética , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Hormônios Tireóideos/genética , Tropomiosina/genética , Regulação para Cima , Proteínas de Ligação a Hormônio da TireoideRESUMO
The post-nuclear particulate fractions of highly enriched mature and immature neutrophil preparations were dissolved in buffer containing sodium dodecyl sulfate and analyzed for protein and glycoprotein components by polyacrylamide gel electrophoresis. The electrophoretic patterns of mature and immature neutrophils showed pronounced differences in both protein and glycoprotein bands. There were 12 prominent protein bands in the patterns of mature neutrophils which also stained for glycoproteins. With one exception, these bands were either greatly reduced in intensity or undetectable at corresponding positions in the patterns of immature cells. The patterns of immature neutrophils revealed three prominent glycoprotein bands, two of which were absent and the third was greatly reduced in intensity at corresponding position in the mature cell patterns. The results indicate that a number of new glycoproteins appear in the later stages of neutrophil maturation, whereas other glycoproteins, present in immature cells, are either lost or greatly reduced in amount. These changes are presumably related to the development of specific cell functions that also appear in later stages of cell maturation.
Assuntos
Bioquímica/métodos , Glicoproteínas/química , Leucócitos/metabolismo , Neutrófilos/metabolismo , Proteínas/química , Animais , Medula Óssea/metabolismo , Eletroforese em Gel de Poliacrilamida , Membrana Eritrocítica/metabolismo , Eritrócitos/metabolismo , Cobaias , Linfócitos/metabolismo , Peso Molecular , Frações Subcelulares/metabolismo , Fatores de TempoRESUMO
We have used PCR to amplify and align the sequence of two genes encoding cGTH alpha. Both genes comprise four exons and three introns. The organization of cGTH alpha genes is very similar to that of mammalian GTH alpha genes. However, the cGTH alpha genes only span a region of 1.2 kb which is much smaller than those mammalian GTH alpha genes.
Assuntos
Carpas/genética , Subunidade alfa de Hormônios Glicoproteicos/genética , Gonadotropinas Hipofisárias/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , DNA de Cadeia Simples , Éxons , Íntrons , Dados de Sequência Molecular , Reação em Cadeia da PolimeraseRESUMO
We have cloned a full-length cDNA encoding the mitogen-activated protein kinase kinase (MKK) from a carp liver cDNA library. The cDNA contains 1970 bp with a single open reading frame encoding a 397 amino acid protein. By comparing with known MKK sequences from other species, carp MKK is 78%, 80%, 76% and 58% identical to rat MKK1, rat MKK2, Xenopus MKK and Drosophila MKK.
Assuntos
Carpas/genética , DNA Complementar/química , Proteínas Serina-Treonina Quinases/genética , Proteínas Tirosina Quinases/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Ativação Enzimática/efeitos dos fármacos , MAP Quinase Quinase 1 , MAP Quinase Quinase 2 , Quinases de Proteína Quinase Ativadas por Mitógeno , Mitógenos/farmacologia , Dados de Sequência Molecular , Alinhamento de SequênciaRESUMO
The CDC37 gene was isolated from a round-spotted pufferfish genomic library and characterized. This gene is composed of nine exons spanning 3.5 kb. Exon 1 contains the 5'-untranslated region and exon 2 contains the putative translation initiation site. By 5'-RACE (rapid amplication of cDNA ends) and sequence analysis, we deduced the promoter region for the CDC37 gene and found that it does not contain typical TATA or CCAAT box. The 1.8 kb DNA fragment upstream of the putative transcription initiation site contains numerous potential binding sites for transcription factors including CREB, E2A, Ets-1, GATA, NF-IL6 and PEA3. When this DNA fragment was placed upstream of the chloramphenicol acetyltransferase (CAT) reporter gene and transfected into a carp CF cell line, it could drive the synthesis of CAT enzyme four times more efficiently than the promoterless pCAT-Basic did. In addition, the CDC37 gene is linked to the TYK2 gene in a tail-to-head manner with a small intergenic region of 292 bp.
Assuntos
Proteínas de Ciclo Celular/genética , Proteínas de Drosophila , Éxons/genética , Peixes/genética , Íntrons/genética , Chaperonas Moleculares , Regiões Promotoras Genéticas/genética , Proteínas Tirosina Quinases , Regiões 5' não Traduzidas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Carpas , Proteínas de Ciclo Celular/química , Linhagem Celular , Clonagem Molecular , Códon de Iniciação/genética , Regulação da Expressão Gênica , Ordem dos Genes , Genes Reporter/genética , Genoma , Dados de Sequência Molecular , Proteínas/genética , Elementos de Resposta/genética , Alinhamento de Sequência , TransfecçãoRESUMO
BACKGROUND: Although MTBDRplus is validated for the detection of multidrug-resistant tuberculosis (MDR-TB), its role in the assessment of treatment outcome is less clear. We evaluated the association of MTBDRplus results with treatment outcome in new and previously treated patients in an endemic setting in China and determined factors associated with poor treatment outcomes. METHODS: We prospectively enrolled 298 smear-positive pulmonary TB patients who received the World Health Organization recommended initial treatment regimen or retreatment regimen. MTBDRplus was compared with conventional drug susceptibility testing and DNA sequencing for the detection of MDR-TB. Treatment responses were monitored using sputum smear, culture and chest radiography. RESULTS: MTBDRplus successfully identified all MDR-TB and had good concordance with sequencing. MDR-TB rates were low among new patients (4/187, 2.1%), but high in previously treated patients (12/28, 42.9%); 65.2% (15/23) of previously treated cases and 17.1% (27/158) of new cases were unsuccessfully treated (P < 0.001). Seven of eight (87.5%) previously treated MDR-TB patients failed the retreatment regimen. In addition to drug resistance, sputum smear positivity at week 8 and cavitation are associated with treatment failure. CONCLUSION: Not only did MTBDRplus correctly identify all MDR-TB cases, MTBDRplus results are also associated with treatment outcomes in previously treated patients. The retreatment regimen should no longer be used; treatment should be guided by molecular testing.
Assuntos
DNA Bacteriano/isolamento & purificação , Técnicas de Diagnóstico Molecular , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Pulmonar/diagnóstico , Antituberculosos/uso terapêutico , China/epidemiologia , Farmacorresistência Bacteriana Múltipla , Feminino , Técnicas de Genotipagem , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Estudos Prospectivos , Retratamento , Sensibilidade e Especificidade , Análise de Sequência de DNA , Escarro/microbiologia , Falha de Tratamento , Resultado do Tratamento , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Pulmonar/tratamento farmacológico , Organização Mundial da SaúdeRESUMO
The presence of endothelin (ET) immunoreactivity and binding sites in hypothalamus and pituitary gland suggests potential neuroendocrine actions of this family of vasoactive peptides. ET-3, the predominant member of the ET family in brain, exerted significant dose-related (1, 10, and 100 nM) inhibitory effects on PRL release from dispersed anterior pituitary cells in static incubations. The effect was not dependent on voltage-sensitive calcium channels, since the dihydropyridine calcium channel antagonist nifedipine failed to block this action. Nifedipine did, however, significantly reduce the transient acute stimulatory effect of ET-3 on PRL release in cultured cells incubated in dynamic perifusion. The longer lasting inhibitory effect on PRL release that followed the brief stimulatory action was not affected by nifedipine. ET-3 also stimulated a transient but significant release of LH from cells harvested from random cycle female rats, an effect that was not antagonized by a LHRH antagonist, but was blocked by nifedipine, suggesting the mobilization of extracellular calcium as a mechanism of action of ET-3. Nifedipine also reversed the acute stimulatory effect of ET-3 on GH secretion from these cells. Cerebroventricular injections of ET-3 (6 or 60 ng) failed to significantly alter PRL or LH secretion in conscious rats, suggesting that brain-derived ET does not act within the hypothalamus to alter the release of these two hormones. Similarly, iv infusion of even pressor doses of ET-3 (10, 30, or 300 ng) failed to significantly alter PRL, LH, or GH release; thus, it is unlikely that ET of peripheral origin acts within the gland. Our results suggest that locally produced ET may act as a neuroendocrine or paracrine factor controlling pituitary function in the rat.
Assuntos
Endotelinas/fisiologia , Sistemas Neurossecretores/fisiologia , Animais , Células Cultivadas , Relação Dose-Resposta a Droga , Interações Medicamentosas , Feminino , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Hormônio Liberador de Gonadotropina/farmacologia , Hormônio do Crescimento/sangue , Hormônio do Crescimento/metabolismo , Hormônio Luteinizante/sangue , Hormônio Luteinizante/metabolismo , Masculino , Sistemas Neurossecretores/citologia , Nifedipino/farmacologia , Adeno-Hipófise/citologia , Adeno-Hipófise/metabolismo , Prolactina/sangue , Ratos , Ratos EndogâmicosRESUMO
Both A- and C-type natriuretic peptides (ANP and CNP, respectively) significantly reduce LH secretion when injected into the third cerebral ventricle of conscious rats. To establish which natriuretic peptide receptor subtype transduces these inhibitory messages, we have employed novel cytotoxin cell targeting techniques to selectively destroy cells in the hypothalamus that respond to ANP or CNP. Rats pretreated with ANP conjugated to the toxic A-chain of the plant cytotoxin ricin failed 1 week later to respond to central injection of ANP with the normal inhibition of LH secretion. These rats did, however, respond with significant inhibition of LH secretion to central injection of CNP. In fact, the LH inhibition observed after CNP injection was significantly greater than that expressed after similar injection of CNP in rats pretreated with unconjugated ricin A-chain (toxin control). Those control rats displayed significant reduction of LH levels in response to ANP injection as well. Plasma LH levels were not significantly affected by central administration of either ANP or CNP in rats pretreated with ricin A-chain conjugated to CNP. These results further demonstrate the power of this novel technology and provide positive evidence supporting our hypothesis that ANP exerts its LH-inhibiting effect by displacing endogenous CNP from clearance receptors within the brain. This endogenous CNP, then, like exogenously applied CNP, activates the guanyl cyclase-B receptors on cells, which are part of the network controlling the release of LHRH.
Assuntos
Fator Natriurético Atrial/farmacologia , Ventrículos Cerebrais/fisiologia , Hipotálamo/fisiologia , Hormônio Luteinizante/metabolismo , Proteínas do Tecido Nervoso/farmacologia , Receptores do Fator Natriurético Atrial/metabolismo , Animais , Fator Natriurético Atrial/administração & dosagem , Fator Natriurético Atrial/metabolismo , Ventrículos Cerebrais/efeitos dos fármacos , Feminino , Hipotálamo/efeitos dos fármacos , Injeções Intraventriculares , Cinética , Ligantes , Hormônio Luteinizante/sangue , Peptídeo Natriurético Tipo C , Proteínas do Tecido Nervoso/administração & dosagem , Proteínas do Tecido Nervoso/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores do Fator Natriurético Atrial/efeitos dos fármacos , Ricina/farmacologia , Fatores de TempoRESUMO
Involvement of an L-type Ca2+ channel in the regulation of spontaneous transmitter release was studied in Xenopus nerve-muscle cultures. The frequency of spontaneous synaptic currents, which reflects impulse-independent acetylcholine release from the nerve terminals, showed a marked increase in high-K+ medium or after treatment with a phorbol ester, 12-O-tetradecanoyl-phorbol 13-acetate, a drug that activates protein kinase C and depolarizes the presynaptic neuron. The potentiation effect of high K+ and 12-O-tetradecanoyl-phorbol 13-acetate requires Ca2+ influx through the L-type Ca2+ channel in the plasma membrane, since it was significantly reduced by the presence of nifedipine, verapamil or diltiazem and enhanced by Bay K 8644, an L-type Ca2+ channel agonist. It was shown recently that adenosine 5'-triphosphate markedly potentiates the spontaneous acetylcholine release at these synapses through the binding of P2-purinoceptors and the activation of protein kinase C. We found in the present study that potentiation effects of adenosine 5'-triphosphate are inhibited by L-type Ca2+ channel blockers, suggesting that the L-type Ca2+ channel is responsible for the positive regulation of spontaneous acetylcholine secretion by adenosine 5'-triphosphate at the developing neuromuscular synapses. Our data suggest that modulation of the L-type Ca2+ channel in embryonic motor nerve terminals is important for the regulation of spontaneous transmitter release.
Assuntos
Acetilcolina/metabolismo , Canais de Cálcio/fisiologia , Junção Neuromuscular/metabolismo , Transmissão Sináptica/fisiologia , Éster Metílico do Ácido 3-Piridinacarboxílico, 1,4-Di-Hidro-2,6-Dimetil-5-Nitro-4-(2-(Trifluormetil)fenil)/farmacologia , Trifosfato de Adenosina/fisiologia , Animais , Cálcio/metabolismo , Canais de Cálcio/classificação , Canais de Cálcio/efeitos dos fármacos , Junção Neuromuscular/efeitos dos fármacos , Nifedipino/farmacologia , Técnicas de Cultura de Órgãos , Potássio/farmacologia , Proteína Quinase C/fisiologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Transmissão Sináptica/efeitos dos fármacos , Acetato de Tetradecanoilforbol/farmacologia , Xenopus/embriologiaRESUMO
Lens epithelial cells from normal and Nakano adult mice have been cultured for over 1 year, and the cells have retained certain differentiated characteristics. Fluorescent antibody to mouse gamma crystallin reacted with the spherical lentoid bodies which appeared approximately 2 weeks after the start of the culture. The lentoid bodies also contained cells which had few cell organelles and homogenous cytoplasms. Both gamma crystallin production and loss of cellular organelles are characteristics of differentiated fiber cells rather than epithelial cells. An inhibitor of the Na-K ATPase is responsible for the hydration and subsequent cataract formation in the Nakamo mouse. The inhibitor of the Na-K ATPase was demonstrated in the lens in culture from the Nakamo mice, but no inhibitory activity was detected in the cultures from normal mice.
Assuntos
Células Epiteliais , Epitélio/ultraestrutura , Cristalino/ultraestrutura , Adenosina Trifosfatases/antagonistas & inibidores , Animais , Catarata/etiologia , Cristalinas/imunologia , Técnicas de Cultura , Imunofluorescência , Camundongos , Organoides/ultraestrutura , Especificidade da EspécieRESUMO
1. Previously we have shown that extracellular application of ATP, a substance co-stored and co-released with acetylcholine (ACh) in the peripheral nervous system, markedly potentiated the frequency of spontaneous synaptic currents (SSCs) produced by ACh. In the present study, we have further characterized the purinoceptor which mediates the potentiation effect of ATP and the role of endogenously released ATP. 2. Pretreatment with a P2-purinoceptor antagonist, suramin (0.3 mM), but not a P1-purinoceptor antagonist, 8-phenyltheophylline (0.1 mM), prevented the potentiating effect of ATP. 3. We studied the role of endogenously released ATP by examining the effect of a specific P2-purinoceptor antagonist on the frequency of spontaneous synaptic events at high-activity synapses (> or = 3 Hz) and found that suramin, but not 8-phenyltheophylline markedly reduced the frequency of SSCs at these high-activity synapses. In addition, desensitizing the P2-purinoceptor with alpha,beta-methylene ATP also produced similar effects to suramin. 4. Extracellular application of the L-type Ca2+ channel blockers, verapamil, nifedipine or diltiazem (10 microM each) reduced SSC frequency of high-activity synapses, while the N-type Ca2+ channel blocker, omega-conotoxin had no appreciable effect. The potentiating effect of ATP was further prevented by pretreatment with the L-type Ca2+ channel blockers. On the other hand, Bay K 8644, which is a depolarization-dependent L-type Ca2+ channel agonist, potentiated SSC frequency at these high-activity synapses. 5. These results suggest that endogenous release of ATP at developing neuromuscular synapses is responsible for the maintenance of high levels of spontaneous ACh release, which is known to play a crucial role in regulating postsynaptic differentiation.