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1.
Zhonghua Yu Fang Yi Xue Za Zhi ; 51(9): 832-836, 2017 Sep 06.
Artigo em Zh | MEDLINE | ID: mdl-28881550

RESUMO

Objective: To analyze the prevalence and drug resistance of mycoplasma pneumoniae in patients with community-acquired pneumonia during 2011-2015 in Beijing. Methods: Totally 2 272 mycoplasma pneumoniae samples were collected from patients with community-acquired pneumonia in 5 sentinel hospitals during 2011-2015. Mycoplasma pneumoniae were detected by real-time PCR. 142 copies of positive samples with Ct value under 30 were cultured to get the strains so that the genotypes based on the P1 gene sequence and the drug resistance based on the in vitro drug resistance test could be conducted. χ(2) test was used to compare the detection rates of mycoplasma pneumoniae among different age groups and different onset-phase. Results: The positive rate of mycoplasma pneumoniae was 13.6%(308 cases). The positive rate in groups aging (5-14), (15-24) and ≥60 years old were separately 24.4% (67/275), 24.4% (38/156) and 3.9% (28/727) (χ(2)=1.22, P<0.001). The annual detection rate of mycoplasma pneumoniae in 2011-2015 were 14.6% (73/501), 10.2% (36/353), 26.4% (101/383), 10.3% (41/398), 9.0% (57/637),respectively (χ(2)=72.65, P<0.001). Seasonally, the peak of positive rate was between October and December (17.5%, 122/699) and the lowest positive rate was between April and June (8.6%, 43/502). 36 strains were isolated from 142 swabs and 23 (63.9%) were P1-Ⅰ and 13 (36.1%) were P1-Ⅱ by genotyping. All isolates were susceptible to the fluoroquinolones (levofloxacin, ciprofloxacin, and gatifloxacin) and tetracycline. All P1-Ⅱ strains were susceptible to macrolides while most of the P1-Ⅰ strains (22 strains) were macrolide-resistant. Conclusion: People aging (5-14) and (15-24) years old were more susceptible to mycoplasma pneumoniae in patients with community-acquired pneumonia in Beijing between 2011 and 2015. The highest positive rate of mycoplasma pneumoniae was in 2013 and the case distributed in all seasons. The major popular genotype was P1-Ⅰ, whose strains were mostly macrolide-resistant.


Assuntos
Antibacterianos/farmacologia , Infecções Comunitárias Adquiridas/tratamento farmacológico , Farmacorresistência Bacteriana , Mycoplasma pneumoniae/efeitos dos fármacos , Pneumonia por Mycoplasma/tratamento farmacológico , Adolescente , Pequim/epidemiologia , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/epidemiologia , Humanos , Pessoa de Meia-Idade , Pneumonia por Mycoplasma/epidemiologia , Adulto Jovem
3.
Water Sci Technol ; 67(3): 477-84, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23202550

RESUMO

In the present study, nano-sized TiO(2)/Al(2)O(3) modified polyvinylidene fluoride (PVDF) membranes (MM) were fabricated and then utilized for oil/water emulsion separation. The results showed that, compared with PVDF membrane (OM), the contact angle of MM decreased and hydrophilicity increased. The ultrafiltration (UF) of oil in water emulsions with transmembrane pressure (TMP) increasing results in a sharp fall in relative flux with time. The cake filtration models did not always predict the performance over the complete range of filtration times very well. In the initial 30 min, all the four cake models can simulate this UF process to a certain extent, and the suitability was: cake filtration > intermediate pore blocking > standard pore blocking > complete pore blocking models. However, they were no longer adapted well with UF time extent to 60 min, but only cake filtration (R(2) = 0.9535) maintained a high adaptability. Surface and cross-sectional morphology of the membrane was investigated by SEM to make an advanced certificate of this UF mechanism.


Assuntos
Óxido de Alumínio/química , Membranas Artificiais , Nanopartículas/química , Polivinil/química , Titânio/química , Purificação da Água , Incrustação Biológica , Modelos Teóricos , Ultrafiltração/instrumentação
4.
Eur Rev Med Pharmacol Sci ; 27(17): 8144-8153, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37750642

RESUMO

OBJECTIVE: The Naples prognostic score (NPS) is a newly developed indicator of inflammation and nutritional status. However, its role in predicting the prognosis of lung cancer is unclear. We hereby reviewed the association between NPS and outcomes of lung cancer. MATERIALS AND METHODS: PubMed, Web of Science, Embase, and Google Scholar were searched up to 15th April 2023 for studies assessing the predictive role of NPS for overall survival (OS) and disease-free survival (DFS) in lung cancer. RESULTS: Seven studies were included. All were from China. One study was on small cell lung cancer, while the rest were on non-small cell lung cancer. Meta-analysis demonstrated that a high NPS score was a significant predictor of OS (HR: 3.21 95% CI: 2.27, 4.54 I2=62%) and disease-free survival (DFS) (HR: 3.81 95% CI: 2.57, 5.64 I2=65%) in lung cancer patients. Subgroup analysis based on different NPS reference values also showed similar results. The results remained significant on sensitivity analysis. CONCLUSIONS: The NPS is a strong and independent prognostic indicator of lung cancer patients. Higher NPS scores are associated with worse OS and DFS. Further studies from non-Chinese populations are needed to supplement the results.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Humanos , Neoplasias Pulmonares/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Prognóstico , Intervalo Livre de Doença
5.
Rev Sci Instrum ; 94(12)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38109469

RESUMO

An E-band (60-90 GHz) multi-channel Doppler backscattering (DBS) system with X-mode polarization has been installed on the Experimental Advanced Superconducting Tokamak (EAST), which can measure the turbulence at five different radial locations simultaneously. This system can launch 31 fixed microwave frequencies in the range of 60-90 GHz with a 1 GHz interval into the plasma, and five probing signals are selected by employing a reference signal and multiple filters. During experiments, the frequency of the reference signal is tunable in the E-band, and the selected probing signals can be changed as needed without any other adjustments, which can be performed in one shot or between shots. Furthermore, the incident angle can be adjusted from -10° to 20°, and the wavenumber range is 4-25 cm-1 with a wavenumber resolution of Δk/k ≤ 0.35. Ray tracing simulations are employed to calculate the scattering locations and the perpendicular wavenumber. In this article, the hardware design, ray tracing, and initial results obtained from the EAST plasma will be presented.

6.
Epidemiol Infect ; 139(1): 52-8, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20854713

RESUMO

In order to determine the prevalence of antibody against 2009 H1N1 influenza in Beijing, we conducted a serological survey in 710 subjects, 1 month after the epidemic peak. We found that 13·8% of our cohort was seropositive. Subjects aged ≥60 years recorded the lowest seroprevalence (4·5%). The age-weighted seroprevalence of 14·0% was far lower than the supposed infection rate at the epidemic peak, derived from the basic reproduction number for 2009 H1N1 virus. For subjects who had received the pandemic vaccine seroprevalence was 51·4%. In subjects aged ≥60 years the seasonal influenza vaccination was not significantly associated with being seropositive. Our study suggests that many factors, and not just the immunological level against 2009 H1N1 influenza in the community, affected the spread of the virus within the population of Beijing.


Assuntos
Anticorpos Antivirais/sangue , Vírus da Influenza A Subtipo H1N1/imunologia , Influenza Humana/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Criança , Pré-Escolar , China/epidemiologia , Estudos de Coortes , Feminino , Humanos , Lactente , Recém-Nascido , Influenza Humana/sangue , Influenza Humana/imunologia , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Estudos Soroepidemiológicos , Adulto Jovem
7.
Water Sci Technol ; 64(9): 1892-7, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22020484

RESUMO

Polyvinylidene fluoride (PVDF) flat ultrafiltration membranes modified by nano-sized alumina (Al2O3) particles were prepared by phase inversion process and their properties and anti-fouling performances were examined. The influence of three types of natural organic matters on the modified membrane fouling was also studied. Raw water was taken from two different locations, i.e., Harbin and Zhaoyuan, of Songhua River. Dissolved organic compounds in the raw water were fractionated using XAD resins into three fractions, i.e., hydrophobic fraction, transphilic fraction, and hydrophilic fraction (HPI). The three adsorbed compounds were further eluted and dissolved into distilled water respectively to prepare the feed for the fouling tests. All solutions were adjusted to a concentration of 10.6 mg C/L, which equals to the total organic carbon (TOC) of the raw water. Results show that the addition of nano-Al2O3 particulars did not affect the inherent traits of the PVDF membranes, however, its surface hydrophilic properties were improved significantly with the addition of nanoparticles and anti-fouling performance was enhanced as well. The HPIs in the Songhua River were the main foulant, causing more fouling to membrane than hydrophobic and transphilic matters.


Assuntos
Óxido de Alumínio/química , Incrustação Biológica/prevenção & controle , Membranas Artificiais , Nanopartículas/química , Polivinil/química , Rios/química , Ultrafiltração/métodos , Fracionamento Químico , China , Cromatografia Gasosa-Espectrometria de Massas , Concentração de Íons de Hidrogênio , Microscopia de Força Atômica , Compostos Orgânicos/química , Poluentes Químicos da Água/análise , Purificação da Água , Qualidade da Água
8.
Eur Rev Med Pharmacol Sci ; 22(9): 2580-2587, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29771443

RESUMO

OBJECTIVE: The purpose of this study was to detect ferritin light chain (FTL) expression level in osteosarcoma (OS), and to clarify whether FTL could offer additional help in diagnosis or therapy. MATERIALS AND METHODS: First, we assessed FTL level in OS tissues and cells through GEO dataset and tissue microarrays (TMAs). Then, we overexpressed FTL expression in MG-63 cell line. Lastly, we detected the expression of EMT-related signal pathway proteins to study its underlying molecular mechanisms. RESULTS: GEO dataset and TMAs showed that FTL was down-regulated in OS. After FTL was overexpressed, the proliferation, migration and invasion abilities of OS cells were significantly reduced. Moreover, after FTL overexpressing, the levels of CDH2 and Vimentin were down-regulated with CDH1 up-regulated. CONCLUSIONS: We revealed that FTL (1) is lower in OS then in normal tissue, (2) is related to metastasis, survival period, and therapeutic response, and (3) may be a tumor-inhibiting factor owing to its inhibition of EMT in OS.


Assuntos
Apoferritinas/metabolismo , Neoplasias Ósseas/metabolismo , Transição Epitelial-Mesenquimal , Osteossarcoma/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD/metabolismo , Apoferritinas/genética , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Caderinas/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Criança , Regulação para Baixo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Osteossarcoma/genética , Osteossarcoma/patologia , Transdução de Sinais , Vimentina/metabolismo , Adulto Jovem
9.
Zhonghua Liu Xing Bing Xue Za Zhi ; 39(8): 1096-1099, 2018 Aug 10.
Artigo em Zh | MEDLINE | ID: mdl-30180435

RESUMO

Objective: To establish a classified evaluation system for recognizing the levels of influenza epidemics and to explore the new reporting system on influenza epidemics. Methods: The following 3 indicators, including 1) the number of influenza-like illness, 2) positive rate of detection on influenza virus nucleic acids, and 3) the number of influenza outbreaks were chosen to calculate the synthetic index and to classify the grades of evaluation. Results: 209 weeks during 2013-2017 were classified into 5 grades: Grade 1 were 110 weeks (52.63%), Grade 2 were 47 weeks (22.49%), Grade 3 were 44 weeks (21.05%), Grade 4 were 8 weeks (3.83%), and Grade 5 were 0 week. Conclusion: This classified evaluation system provided simple, comprehensive and comparable reference indicators and used for the evaluation on influenza epidemics, also providing suggestions for influenza prevention and control accordingly.


Assuntos
Surtos de Doenças , Influenza Humana/epidemiologia , Vigilância da População , Pequim/epidemiologia , Epidemias , Humanos , Viroses
10.
Zhonghua Liu Xing Bing Xue Za Zhi ; 39(10): 1375-1380, 2018 Oct 10.
Artigo em Zh | MEDLINE | ID: mdl-30453440

RESUMO

Objective: To analyze the characteristics of super-antigen (SAg) of group A Streptococcus pyogenes (GAS), isolated from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017. Methods: Throat swab specimens from patients with scarlet fever or pharyngeal infections were collected and tested for GAS. Eleven currently known SAg genes including SpeA, speC, speG, speH, speI, speJ, speK, speL, speM, smeZ and ssa were tested by real-time PCR while M protein genes (emm genes) were amplified and sequenced by PCR. Results: A total of 377 GAS were isolated from 6 801 throat swab specimens, with the positive rate as 5.5%. There were obvious changes noticed among speC, speG, speH and speK in three years. A total of 45 SAg genes profiles were observed, according to the SAgs inclusion. There were significant differences appeared in the frequencies among two of the highest SAg genes profiles between emm1 and emm12 strains (χ(2)=38.196, P<0.001; χ(2)=72.310, P<0.001). There also appeared significant differences in the frequencies of speA, speH, speI and speJ between emm1 and emm12 strains (χ(2)=146.154, P<0.001; χ(2)=52.31, P<0.001; χ(2)=58.43, P<0.001; χ(2)=144.70, P<0.001). Conclusions: Obvious changes were noticed among SAg genes including speC, speG, speH and speK from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017. SAg genes including speA, speH, speI and speJ appeared to be associated with the emm 1 and emm 12 strains. More kinds of SAg genes profiles were isolated form GAS but with no significant differences seen in the main SAg genes profiles, during the epidemic period.


Assuntos
Antígenos de Bactérias/genética , Faringite/diagnóstico , Complicações Infecciosas na Gravidez/microbiologia , Escarlatina/diagnóstico , Streptococcus pyogenes/genética , Streptococcus pyogenes/isolamento & purificação , Superantígenos/genética , Proteínas da Membrana Bacteriana Externa , Proteínas de Bactérias , Pequim/epidemiologia , China/epidemiologia , Exotoxinas , Feminino , Humanos , Proteínas de Membrana , Faringite/epidemiologia , Faringite/microbiologia , Faringe/microbiologia , Gravidez , Reação em Cadeia da Polimerase em Tempo Real , Escarlatina/genética , Escarlatina/microbiologia , Infecções Estreptocócicas , Streptococcus pyogenes/imunologia
11.
J Neurosci ; 20(9): 3504-11, 2000 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-10777813

RESUMO

By increasing dopamine (DA) release and activating feedback mechanisms, amphetamine and related psychostimulants are known to inhibit DA cell firing. Here, we report that D-amphetamine also has an excitatory effect on DA cells, which under control conditions, is masked by the inhibitory effect of D-amphetamine and is revealed when D2-like receptors are blocked. Thus, using in vivo single-unit recording in rats, we found that the selective D2 antagonist raclopride not only blocked the inhibition induced by D-amphetamine but also enabled D-amphetamine to excite DA cells. The excitation, expressed as an increase in both firing rate and bursting, persisted when both D1- and D2-like receptors were blocked by SCH23390 and eticlopride, suggesting that it is not mediated by DA receptors. The norepinephrine uptake blocker nisoxetine mimicked the effect of D-amphetamine, especially the increase in bursting, whereas the 5-HT uptake blocker fluoxetine produced no significant effect. Adrenergic alpha1 antagonists prazosin and WB4101 and the nonselective alpha antagonist phenoxybenzamine completely blocked increase in bursting induced by D-amphetamine and partially blocked the increase in firing rate. The alpha2 antagonist idazoxan and the beta antagonist propranolole, however, failed to prevent D-amphetamine from producing the excitation. Thus, revising the traditional concept, this study suggests that D-amphetamine has two effects on DA cells, a DA-mediated inhibition and a non-DA-mediated excitation. The latter is mediated in part through adrenergic alpha1 receptors.


Assuntos
Dextroanfetamina/farmacologia , Dopaminérgicos/farmacologia , Neurônios/efeitos dos fármacos , Receptores Adrenérgicos alfa/efeitos dos fármacos , Receptores Dopaminérgicos/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Antagonistas Adrenérgicos alfa/farmacologia , Animais , Antagonistas de Dopamina/farmacologia , Masculino , Neurônios/fisiologia , Racloprida/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores Adrenérgicos alfa/fisiologia , Receptores Dopaminérgicos/fisiologia , Substância Negra/efeitos dos fármacos , Substância Negra/fisiologia , Área Tegmentar Ventral/efeitos dos fármacos , Área Tegmentar Ventral/fisiologia
12.
Biochim Biophys Acta ; 1201(1): 61-8, 1994 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-7918583

RESUMO

A lectin specific to mannose has been purified from Vicia villosa seed by (NH4)2SO4 fractionation, GalNAc-Sepharose and Man-Sepharose affinity chromatography. It was defined as VVLM, which showed a single band on an acidic-PAGE stained with Coomassie brilliant blue. The molecular weight of VVLM was 50 kDa as determined by gel filtration on Biogel P-100 column. The VVLM molecule consists of 2 distinct subunits with apparent molecular weight of 30 kDa and 22 kDa determined by SDS-PAGE. VVLM has at least four isolectins with similar haemagglutinating activity. Its extinction coefficient is calculated as A1(1cm) = 16.4 at 280 nm. Sugars could not be detected by phenol-sulfuric acid method. The circular dichroism analysis at far UV indicated that VVLM was a beta-sheet-rich protein, and gave no alpha-helix, 69% beta-sheet, 14% beta-turn by Provencher and Glockner method. The lectin was inhibited by alpha-methyl-D-mannose at 12.5 mM and glucose or GlcNAc at 50 mM. The carbohydrate binding specificity of VVLM was investigated by using affinity chromatography on a VVLM-Sepharose column. Among various Asn-linked oligosaccharides, core structure Man alpha 1-->3(Man alpha 1-->6)Man beta 1-->4GlcNAc beta 1-->4GlcNAcOT were found to have high affinity for VVLM-Sepharose. The antisera of VVLM did not produce precipitin line with VVLG in agar double diffusion plate indicating no serological relationship between VVLM and VVLG. However VVLM showed similar immunodeterminants of some other lectins of mannose specificity such as Con A, PSL, LCA and VFL.


Assuntos
Lectinas/isolamento & purificação , Manose/química , Sementes/química , Aminoácidos/análise , Sequência de Carboidratos , Dicroísmo Circular , Lectinas/química , Dados de Sequência Molecular , Estrutura Molecular , Peso Molecular , Oligossacarídeos/química , Lectinas de Plantas
13.
Biochimie ; 75(11): 949-54, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8123701

RESUMO

The conformation of two Vicia villosa lectins specific for mannose and N-acetylgalactosamine, respectively, was studied by circular dichroism. Both showed a broad negative CD band around 220 nm and a positive one above 190 nm. CD data analysis indicated that they were rich in beta-sheet. However, they differed in conformational stability against extreme pH, at elevated temperature, and in guanidine hydrochloride and sodium dodecyl sulfate solutions. The unusual feature was that the conformation of N-acetylgalactosamine-specific lectin was virtually unaltered in 6 M guanidine hydrochloride and 7.5 mM surfactant.


Assuntos
Acetilgalactosamina/metabolismo , Lectinas/química , Manose/metabolismo , Lectinas de Plantas , Cromatografia de Afinidade , Dicroísmo Circular , Guanidina , Guanidinas/química , Hemaglutinação , Concentração de Íons de Hidrogênio , Lectinas/metabolismo , Conformação Proteica , Desnaturação Proteica , Dodecilsulfato de Sódio/química , Temperatura
14.
Neuropsychopharmacology ; 15(5): 437-41, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8914116

RESUMO

To determine whether lesions in the prefrontal cortex (PFC) alter the activity of midbrain dopamine (DA) neurons, single unit recordings were made from DA neurons in control and lesioned rats. PFC lesions, obtained by local injection of ibotenic acid into the medial PFC, had no effect on either firing rate or bursting activity of DA neurons in the ventral tegmental area (VTA). However, the number of spontaneously active DA neurons in the VTA was significantly decreased. In the substantia nigra (SN), the same lesions increased the firing rate and had no effect on either the bursting activity of the number of active DA cells. These results suggest that PFC lesions alter the activity of DA neurons. However, VTA and SN DA neurons may respond differently to PFC lesions.


Assuntos
Mesencéfalo/fisiologia , Neurônios/fisiologia , Córtex Pré-Frontal/efeitos dos fármacos , Animais , Agonistas de Aminoácidos Excitatórios , Ácido Ibotênico , Injeções Intraventriculares , Masculino , Técnicas de Patch-Clamp , Córtex Pré-Frontal/patologia , Ratos , Ratos Sprague-Dawley , Receptores Dopaminérgicos/fisiologia
15.
Neuroscience ; 91(2): 527-35, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10366010

RESUMO

To examine whether dopamine modulates cortical N-methyl-D-aspartate receptor-mediated glutamate transmission, whole-cell recordings were made from identified pyramidal cells located in layers V and VI of the medial prefrontal cortex of the rat using a slice preparation. In the presence of tetrodotoxin and the absence of Mg2+, a brief local application of N-methyl-D-aspartate evoked an inward current which was blocked by the N-methyl-D-aspartate antagonist dizocilpine maleate but not affected by the non-N-methyl-D-aspartate antagonist 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(f)quinoxaline, suggesting that the observed current is mediated by N-methyl-D-aspartate receptors located on recorded cells. Bath application of dopamine produced opposite effects on the N-methyl-D-aspartate current depending on the concentrations of dopamine applied. At low concentrations (<50 microM), dopamine enhanced the N-methyl-D-aspartate current, whereas at higher concentrations, dopamine suppressed the current. The same concentrations of dopamine did not significantly affect the inward current induced by the non-N-methyl-D-aspartate agonist alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid. The enhancing effect of dopamine on the N-methyl-D-aspartate response was mimicked by the D1 agonist SKF38393 and blocked by the D1 antagonist SCH31966, whereas the suppressing effect was mimicked by the D2 agonist quinpirole and blocked by the D2 antagonist eticlopride. The above results suggest that dopamine at low concentrations acts preferentially on D1-like receptors to promote N-methyl-D-aspartate receptor-mediated transmission, while at high concentrations dopamine also activates D2-like receptors, leading to a suppression of the N-methyl-D-aspartate function. This differential modulation of N-methyl-D-aspartate function may have significant implications for understanding behaviors and disorders involving both cortical dopamine- and glutamate-mediated neurotransmission.


Assuntos
Dopamina/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Córtex Pré-Frontal/fisiologia , Células Piramidais/fisiologia , Receptores de N-Metil-D-Aspartato/fisiologia , 1-Metil-3-Isobutilxantina/farmacologia , 2,3,4,5-Tetra-Hidro-7,8-Di-Hidroxi-1-Fenil-1H-3-Benzazepina/farmacologia , Animais , Benzazepinas/farmacologia , Maleato de Dizocilpina/farmacologia , Agonistas de Dopamina/farmacologia , Antagonistas de Dopamina/farmacologia , Relação Dose-Resposta a Droga , Técnicas In Vitro , Masculino , Potenciais da Membrana/efeitos dos fármacos , Córtex Pré-Frontal/efeitos dos fármacos , Células Piramidais/efeitos dos fármacos , Quinoxalinas/farmacologia , Quimpirol/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico/farmacologia
16.
Ann N Y Acad Sci ; 668: 129-45, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1463269

RESUMO

Three effects of NT were observed on midbrain DA cells. The modulatory effect of NT, that is, the attenuation of DA-induced inhibition, has been most extensively examined. Studies indicate that this effect of NT was not simply due to a nonspecific excitation. NT selectively attenuated DA-induced inhibition without affecting either GABA-induced inhibition or glutamate-induced excitation of the same cells, and the attenuation of DA-induced inhibition could be observed at the doses at which the basal activity of DA cells was not changed by NT. The attenuation of DA-induced inhibition by NT is also unlikely to result from the formation of a DA-NT complex, since neuromedin N, which competes with NT for the same receptor but does not bind to DA, mimicked the effects, and neurotensin(1-11), which forms a complex with DA but is inactive in competing for NT receptors, did not. The similarities between the effects of NT and those of 8-bromo-cAMP and forskolin suggest that intracellular cAMP and protein kinase A may be involved. This suggestion was supported by the findings that IBMX (an inhibitor of phosphodiesterases) potentiated the effect of NT; and SQ22536 (an inhibitor of adenylate cyclase) and H8 (an inhibitor of protein kinase A) antagonized it. Phorbal-12,13-dibutyrate (an activator of protein kinase C) did not mimic the effect of neurotensin, and H7 (an inhibitor of protein kinase C) did not reduce the effect, suggesting that protein kinase C is unlikely to be involved in the modulatory effect of neurotensin. Experiments in vitro indicated that the excitatory effect of NT on DA cells occurred at higher concentrations (> 10 nM) than those needed for producing the modulatory effect. Its persistence during DA receptor blockade by sulpiride suggests that this effect was not entirely mediated by an attenuation of the inhibition induced by endogenously released DA. At even higher concentrations (> 100 nM), a sudden cessation of cell activity preceded by an increase in firing rate was observed. Whether this effect of NT was due to depolarization inactivation or a toxic effect of the peptide at high concentrations remains to be determined. In most other areas studied, the excitatory effect of NT was most commonly observed. In many areas, this excitatory effect was apparently a direct postsynaptic effect of NT. However, different mechanisms may be involved (see Table 1). For example, in some areas NT acted through a decrease in membrane conductance, while in others no change or an increase in the membrane conductance was observed.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Neurotensina/metabolismo
17.
J Neurosci Methods ; 35(3): 235-40, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2084393

RESUMO

A small volume chamber for recording from submerged brain slices is described. In the chamber, the slice is covered on all sides by a thin layer of moving medium. The chamber is simple and easy to construct. The small volume of the chamber allows fast exchange of the medium solution surrounding the slice and reduces the complications induced by long time exposure of slices to certain drugs (eg. desensitization). Along with this small volume chamber, a medium supply system is also described, which is composed of a peristaltic pump and a pulse dampener. This pulse-free medium supply system allows cells to be held for up to 8 h with solution changes as frequently as every 10-20 min.


Assuntos
Encéfalo/fisiologia , Eletrofisiologia/instrumentação , Animais , Meios de Cultura , Técnicas de Cultura/instrumentação , Desenho de Equipamento
18.
J Neurosci Methods ; 35(1): 89-91, 1990 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2277537

RESUMO

Several kinds of multibarrel glass blanks are available commercially for making a multibarrel microiontophoresis electrode. Among them are the ones that consist of fused straight lengths of tubing available in three to nine barrels. Although they enjoy many advantages over the other kinds of assemblies, salt bridges form easily between the barrels of the electrodes made from these blanks. These bridges, when they form, render the multibarrel pipette unusable. Here, we describe a simple and effective way to prevent the formation of salt-bridge by coating the end of the barrels with paraffin. The paraffin coated electrode exhibits excellent recording properties which are equivalent to those made from more expensive blanks.


Assuntos
Iontoforese/métodos , Animais , Iontoforese/instrumentação , Microeletrodos , Neurônios/fisiologia , Parafina , Sais
19.
Brain Res ; 543(2): 315-21, 1991 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-1676331

RESUMO

Interactions of neurotensin (NT) with midbrain dopamine (DA) neurons were studied in rats using microiontophoretic techniques. Local ejection of NT significantly increased (greater than 30%) the firing rate of a few DA cells (12/106). In most cases, however, iontophoretic NT produced no significant change in spontaneous activity. On the other hand, in these same cells, NT significantly attenuated the inhibition induced by either DA or quinpirole, a specific D2 agonist. Inhibition induced by DA was not attenuated by either glutamate or cholecystokinin, although both of them increase the firing rate of DA cells. The effect of NT appears to be selective as NT attenuated DA-induced inhibition without a measurable effect on either GABA-induced inhibition or glutamate-induced excitation of the same DA cells. Combined, these results suggest that NT's effect on DA cell activity is primarily a neuromodulatory one. As both NT and D2 receptors in midbrain DA cell areas are primarily located on DA cells, the above results also suggest that the observed interaction between NT and DA occurred at the DA cell level.


Assuntos
Dopamina/fisiologia , Mesencéfalo/fisiologia , Neurotensina/fisiologia , Receptores Dopaminérgicos/fisiologia , Animais , Colecistocinina/farmacologia , Dopaminérgicos/farmacologia , Eletrodos , Ergolinas/farmacologia , Glutamatos/farmacologia , Ácido Glutâmico , Iontoforese , Masculino , Mesencéfalo/citologia , Quimpirol , Ratos , Ratos Endogâmicos
20.
Biomed Environ Sci ; 9(4): 370-9, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8988805

RESUMO

Antibodies to the ubiquitous group of stress proteins known as heat shock proteins (Hsps) have been found to be associated with a number of diseases in humans. Hsps are known to be induced by certain xenobiotics, some of which are common in the working environment. The biological significance of the presence of such autoantibodies is presently unclear. In the present study, we used immunoblotting to investigate the presence of antibodies against the different stress proteins, Hsp27, Hsp60, Hsp71, Hsc (heat shock cognate) 73 and Hsp89 alpha and beta in groups of workers exposed to high temperature or carbon monoxide. These data were related to a detailed clinical evaluation and to various laboratory measurements including electrocardiogram (ECG), B echogram, white blood cell counts and typing, the activity of alanine aminotransferase (ALT), acid phosphatase (ACP) and alkaline phosphatase (ALP) and lymphocyte DNA damage. Antibodies to Hsp27 and Hsp71 were found more frequently in the high temperature and carbon monoxide-exposed groups than in controls (P < 0.05). The carbon monoxide-exposed group showed the highest incidence of anti-Hsp antibodies. Anti-Hsp60 antibodies were only detected in workers exposed to high temperature or carbon monoxide. The percentage of workers with abnormal ECG, B echogram changes and displaying hepatitis B antigen (HBsAg) was higher in the carbon monoxide group than in the control group (P < 0.05). There was a significant increase in the activity of ALT in the high temperature and carbon monoxide groups and in the activities of ACP and ALP in the carbon monoxide group (P < 0.05). The extent of DNA damage measured in lymphocytes was higher in workers from the high temperature and carbon monoxide-exposed groups. We suggest that the increased frequency of antibodies to Hsps is the result of these damages of the release of denatured Hsps and of a decrease in the phagocytic ability of macrophages in these workers. The data gathered in the present study show a statistical relation between the occurrence of antibodies against Hsps and the frequency of health problems in workers and suggest a potential role for the antibodies as useful biomarkers to assess whether workers are experiencing environmental stress.


Assuntos
Anticorpos/sangue , Monóxido de Carbono/toxicidade , Proteínas de Choque Térmico/imunologia , Temperatura Alta , Exposição Ocupacional , Nível de Saúde , Humanos
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