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1.
Phys Rev Lett ; 126(24): 241103, 2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34213924

RESUMO

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25 TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160 TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

2.
Science ; 373(6553): 425-430, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34261813

RESUMO

The Crab Nebula is a bright source of gamma rays powered by the Crab Pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind. We report the detection of gamma rays from this source with energies from 5 × 10-4 to 1.1 peta-electron volts with a spectrum showing gradual steepening over three energy decades. The ultrahigh-energy photons imply the presence of a peta-electron volt electron accelerator (a pevatron) in the nebula, with an acceleration rate exceeding 15% of the theoretical limit. We constrain the pevatron's size between 0.025 and 0.1 parsecs and the magnetic field to ≈110 microgauss. The production rate of peta-electron volt electrons, 2.5 × 1036 ergs per second, constitutes 0.5% of the pulsar spin-down luminosity, although we cannot exclude a contribution of peta-electron volt protons to the production of the highest-energy gamma rays.

3.
Phys Rev Lett ; 126(20): 201102, 2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-34110215

RESUMO

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

4.
Nature ; 594(7861): 33-36, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34002091

RESUMO

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 1015 electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays1. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. 2). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.

5.
Epidemiol Infect ; 148: e154, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32660668

RESUMO

There is limited information concerning the viral load of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in aerosols deposited on environmental surfaces and the effectiveness of infection prevention and control procedures on eliminating SARS-CoV-2 contamination in hospital settings. We examined the concentration of SARS-CoV-2 in aerosol samples and on environmental surfaces in a hospital designated for treating severe COVID-19 patients. Aerosol samples were collected by a microbial air sampler, and environmental surfaces were sampled using sterile premoistened swabs at multiple sites. Ninety surface swabs and 135 aerosol samples were collected. Only two swabs, sampled from the inside of a patient's mask, were positive for SARS-CoV-2 RNA. All other swabs and aerosol samples were negative for the virus. Our study indicated that strict implementation of infection prevention and control procedures was highly effective in eliminating aerosol and environmental borne SARS-CoV-2 RNA thereby reducing the risk of cross-infection in hospitals.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Infecção Hospitalar/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pneumonia Viral/virologia , RNA Viral/isolamento & purificação , Carga Viral , Aerossóis , Betacoronavirus/genética , COVID-19 , Infecções por Coronavirus/transmissão , Infecção Hospitalar/transmissão , Infecção Hospitalar/virologia , Meio Ambiente , Microbiologia Ambiental , Hospitais Universitários , Humanos , Máscaras/virologia , Pneumonia Viral/transmissão , SARS-CoV-2
6.
Epidemiol Infect ; 148: e59, 2020 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-32089146

RESUMO

Tuberculosis (TB) is generally considered a disease that principally afflicts the low-income segments of a population. In the Nanshan District of Shenzhen, China, with the economic transformation and a new Headquarters Economy (HE) emerging, there are now more cases in office workers than in manufacturing workers. To illustrate this trend, we describe a small TB outbreak in an office building located in the centre of the rapidly growing HE district. Two active pulmonary tuberculosis cases were found in workers who shared an office, and whole genome sequencing showed that the genetic distance between the strains of the two cases was just one single nucleotide polymorphism, consistent with intra-office transmission. Investigation of 30 other workers in the same or adjacent offices with interviews, interferon-gamma release assays (IGRAs) and chest X-rays, identified one new TB case and latent tuberculosis infection (LTBI) in 40.0% (12/30) of the contacts. The offices were under-ventilated. None of the IGRA positive, asymptomatic contacts agreed to receive treatment for LTBI, presumably due to TB stigma, and over the next 2 years 69.0% (20/29) of the contacts were lost to follow-up. Treatment for LTBI and stigma of TB remain challenges here. Office workers in the HE of rapidly economic developing areas should be targeted with increased vigilance by TB control programmes.


Assuntos
Surtos de Doenças , Tuberculose Pulmonar , Adulto , China/epidemiologia , Busca de Comunicante , Feminino , Humanos , Masculino , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/prevenção & controle , Tuberculose Pulmonar/transmissão , Local de Trabalho
7.
Sci Adv ; 5(9): eaax3793, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31799401

RESUMO

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 1/2 years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

8.
Eur Rev Med Pharmacol Sci ; 23(20): 9041-9049, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31696494

RESUMO

OBJECTIVE: To explore the effect of the long non-coding ribonucleic acid (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on rats with myocardial infarction (MI) by regulating the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) signaling pathway. MATERIALS AND METHODS: The Sprague- Dawley (SD) rat model of MI was established, and lncRNA MALAT1 was overexpressed using pcDNA-MALAT1 plasmids (MALAT1 group, n=10) and silenced using RNA interference technique (siMALAT1 group, n=10). The Sham group (n=10) was also set up. The transfection efficiency of lncRNA MALAT1 in rats was detected via Reverse Transcription-Polymerase Chain Reaction (RT-PCR). 2 weeks after the successful modeling, the cardiac function indexes were measured through magnetic resonance imaging (MRI) and echocardiography (ECG). The myocardial tissue injury was observed via hematoxylin-eosin (HE) staining, and the apoptosis of myocardial tissues was detected via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Moreover, the levels of the serum inflammatory factors were detected via enzyme-linked immunosorbent assay (ELISA), the messenger RNA (mRNA) expressions of Collagen I and III, the apoptosis, the and pathway genes were detected via RT-PCR. The expressions of ERK/MAPK pathway-related proteins in myocardial tissues were detected via Western blotting. RESULTS: The expression of lncRNA MALAT1 was remarkably increased in the MALAT1 group but evidently declined in the siMALAT1 group (p<0.05), indicating the successful transfection. The fractional shortening (FS, %) and ejection fraction (EF, %) were significantly restored in siMALAT1 group (p<0.05), suggesting that the silence of MALAT1 can improve the cardiac function after acute MI. The results of the HE staining and TUNEL assay manifested that siMALAT1 group had milder myocardial injury and decreased apoptosis compared with MALAT1 group. In the MALAT1 group, the mRNA expressions of Collagen I and III, Caspase3, ERK2, and MAPK were remarkably increased (p<0.05), while the mRNA expression of Bcl-2 was remarkably decreased (p<0.05). The above expressions had the opposite trends in siMALAT1 group. Besides, the protein expressions of ERK2 and MAPK in MALAT1 group were significantly increased (p<0.05). CONCLUSIONS: The downregulation of lncRNA MALAT1 can significantly improve the cardiac function after MI in SD rats mainly by inhibiting the ERK/MAPK pathway.


Assuntos
Sistema de Sinalização das MAP Quinases , Infarto do Miocárdio/genética , RNA Longo não Codificante/genética , Regulação para Cima , Animais , Apoptose , Modelos Animais de Doenças , Masculino , Infarto do Miocárdio/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais
10.
Zhonghua Liu Xing Bing Xue Za Zhi ; 37(11): 1480-1484, 2016 Nov 10.
Artigo em Chinês | MEDLINE | ID: mdl-28057139

RESUMO

Objective: To evaluate the influence of data quality on the sensitivity of early warning syndromic surveillance system based on medical institutions in Qianjiang, Hubei province and explore the relationship between data quality and sensitivity of early warning of the system. Methods: The delay reporting rate and underreporting rate were calculated for the evaluation of the data quality. Data obtained from semi-synthetic simulated outbreak and area under the curve (AUC) were used in combination to test the sensitivity of early warning of various models and select the optimal model. Time-series generalized additive model (GAM) was used to analyze the curve fitting and threshold effect between data quality and early warning sensitivity of the system. Results: A total of 179 905 cases were reported from April 1, 2012 to January 31, 2014, in which 8 744 were not reported timely (16.45%). Averagely 416 reporting were delayed in each month. There were 2 566 cases which were underreported (4.83%). Compared with other early warning models, i.e. Cumulative Sum (CUSUM), Shewhart, Exponentially Weighted Moving Average (EWMA), Early Aberration Reporting System (EARS-3C), the MA model had the maximum area under the curve (AUC=0.93), and the difference was significant (P<0.001). The early warning sensitivity ranged from 84.89% to 97.25% during the operation period of the syndromic surveillance system. Underreporting had influence on early warning sensitivity, when underreporting rate was over 2.78%, the sensitivity would decrease obviously. No obvious associations were observed between the delay reporting rate and early warning sensitivity of the system. Conclusion: The data quality had influence on the early warning sensitivity of the syndromic surveillance system based on medical institution in Qianjiang. In the context of this study, underreporting had the main influence on the sensitivity of early warning.


Assuntos
Confiabilidade dos Dados , Surtos de Doenças , Instalações de Saúde , Humanos , Síndrome
11.
Lupus ; 22(14): 1455-61, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24122723

RESUMO

Plasma gelsolin, the extracellular gelsolin isoform, circulates in the blood of healthy individuals at a concentration of 200 ± 50 mg/l and plays important roles in the extracellular actin-scavenging system during tissue damage. Decreased plasma gelsolin levels have been observed in many inflammatory diseases. In the present study, the variation and potential clinical application of plasma gelsolin levels in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) were analysed. Plasma samples and clinical data were collected from informed and consenting participants: 47 SLE patients, 60 RA patients and 50 age- and gender-matched healthy individuals. Semiquantitative western blotting was used for measuring plasma gelsolin levels. The plasma gelsolin levels in patients with SLE and RA were significantly decreased compared with healthy controls (145.3 ± 40.4 versus 182.7 ± 38.3 mg/l and 100.8 ± 36 versus 182.7 ± 38.3 mg/l, p < 0.001), and plasma gelsolin levels were especially lower in RA than in SLE patients (100.8 ± 36 versus 145.3 ± 40.4 mg/L, p < 0.001). An analysis of the clinical data showed a significant negative correlation between plasma gelsolin levels and SLE Disease Activity Index (SLEDAI) scores (r = 0.659, p < 0.001) but no correlation between plasma gelsolin levels and RA disease activity score 28 (DAS28) (r = 0.076, p = 0.569). Different clinical characteristics were also observed in SLE and RA patients with normal and decreased plasma gelsolin levels.This study found significantly lower plasma gelsolin levels in patients with SLE and RA compared with healthy controls and documented a significant negative correlation between plasma gelsolin levels and SLEDAI, which suggested the potential clinical application of plasma gelsolin in SLE diagnosis and disease activity evaluation. The different clinical characteristics in SLE and RA patients with normal and decreased plasma gelsolin levels indicate differences in the basis of the diseases.


Assuntos
Artrite Reumatoide/fisiopatologia , Gelsolina/sangue , Lúpus Eritematoso Sistêmico/fisiopatologia , Adulto , Artrite Reumatoide/sangue , Western Blotting , Estudos de Casos e Controles , Feminino , Humanos , Lúpus Eritematoso Sistêmico/sangue , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
12.
Drug Dev Ind Pharm ; 39(1): 156-61, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22397600

RESUMO

The purpose of this study was to compare the in vitro release and the in vivo pharmacokinetics of bilayer tablets with the conventional dispersible tablets of nimesulide. The tablets were administered to beagle dogs and the plasma levels of nimesulide were determined by high-performance liquid chromatography-MS/MS. The pharmacokinetic parameters were calculated using a noncompartmental model. The bilayer tablets showed a biphasic in vitro release pattern with initial burst release and sustained release following the quasi-Fickian diffusion-based release mechanism. The C(max), t(max), mean residence time (MRT), and area under the curve from 0 to 36 h were 10.8 ± 4.2 µg/mL, 2.3 ± 1.0 h, 6.7 ± 2.1 h, 81.5 ± 26.7 µg·h/mL for the bilayer tablets and 14.8 ± 5.8 µg/mL, 2.7 ± 0.8 h, 5.6 ± 0.9 h, 95.4 ± 44.2 µg·h/mL for the dispersible tablets. Compared with the dispersible tablets, the bilayer tablets have lower C(max), similar t(max), and longer MRT. The aforementioned pharmacokinetic parameters, especially the MRT demonstrated to be valuable for evaluating the biphasic characteristics. This study provides a promising in vivo evaluation method for the bilayer tablets with biphasic release pattern.


Assuntos
Anti-Inflamatórios não Esteroides/farmacocinética , Preparações de Ação Retardada/farmacocinética , Sulfonamidas/farmacocinética , Análise de Variância , Animais , Área Sob a Curva , Disponibilidade Biológica , Cães , Composição de Medicamentos/métodos , Comprimidos/farmacocinética , Distribuição Tecidual
13.
Hernia ; 14(3): 259-64, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20012331

RESUMO

PURPOSE: This retrospective study aimed to evaluate the risk factors for bowel resection and outcome in patients with incarcerated groin hernias. METHODS: The records of all adult patients who had undergone emergency hernia repair for incarcerated groin hernia from January 1999 to June 2009 were analyzed. One hundred and eighty-two patients with incarcerated groin hernias were included in this study. Bowel resection was required in 28 patients (15.4%). RESULTS: One hundred and twenty-six patients (69.2%) were covered by various types of health insurance. Twenty-six patients (14.3%) were hospitalized for mechanical bowel obstruction or had obvious symptoms of simultaneous bowel obstruction. Obvious peritonitis was found in seven patients (3.8%). A logistic regression model identified three independent risk factors for bowel resection: lack of health insurance (odds ratio [OR], 5, P = 0.005), obvious peritonitis (OR, 11.52, P = 0.019), and femoral hernia (OR, 8.31, P < 0.001). Postoperative complications (standardized coefficient [SC] = 0.478, P < 0.001), presentation of bowel obstruction on admission (SC = 0.169, P = 0.017), and having health insurance (SC = 0.153, P = 0.030) were associated with prolonged length of stay. No factors were found to be directly associated with morbidity or mortality. CONCLUSIONS: Risk for intestinal resection in emergency groin hernia repair is higher in patients with femoral hernia, obvious peritonitis, or those with no health insurance. Surgeons should pay more attention to these patients and initiate emergency surgery without delay.


Assuntos
Hérnia Inguinal/cirurgia , Obstrução Intestinal/cirurgia , Intestinos/cirurgia , Isquemia/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Hérnia Inguinal/complicações , Humanos , Obstrução Intestinal/etiologia , Intestinos/irrigação sanguínea , Isquemia/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento , Adulto Jovem
14.
Poult Sci ; 87(11): 2231-3, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18931172

RESUMO

According to Mendelian heredity laws, the sex ratio of a given chicken population during hatching is expected to be 1:1. In this study, we collected 432 chicken embryos that died during the first week of incubation from 5 different breeds. The sexes of the early-dead embryos were determined by using the previously described molecular sexing technique of double PCR. The female-to-male sex ratio was analyzed for departure from the expected 1:1 sex ratio by chi(2) testing. These results showed that the number of female dead embryos was significantly greater than that of males in the Hubei local breeding stock, Zhusi, and Hy-line Variety Brown (P < 0.05, P < 0.01, P < 0.01 respectively), with observed female-to-male sex ratios of 1.40:1, 2.03:1, and 2.22:1, respectively. Two other Chinese local breeds (the Yellow chicken and the Aijiaohuang chicken) also showed altered sex ratios, although the differences were not significant. Altogether, these results indicated that female chickens were more likely than male chickens to die at the early stages of incubation.


Assuntos
Aborto Espontâneo , Embrião de Galinha/patologia , Perda do Embrião/epidemiologia , Animais , Embrião de Galinha/fisiologia , Galinhas/classificação , Primers do DNA , Perda do Embrião/genética , Feminino , Masculino , Reação em Cadeia da Polimerase , Razão de Masculinidade , Especificidade da Espécie
15.
Sheng Li Xue Bao ; 53(2): 103-7, 2001 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-11471207

RESUMO

The purpose of the present study was to explore whether substance P (SP) modulates the response mediated by GABAA receptors. Experiments were carried out on cultured hippocampal pyramidal neurons of rats. GABA-activated inward currents were recorded using the whole-cell-patch-clamp technique. The majority of the neurons examined (66/92, 72%) were sensitive to both GABA and SP. When the neurons were treated with SP prior to application of GABA, the GABA-activated current (IGABA) was inhibited markedly, which was concentration-dependent and could be blocked by spantide, an NK1 receptor antagonist. With 10(-8), 10(-7), 10(-6) and 10(-5) mol/L SP, IGABA was inhibited by 18%, 24.8%, 25.9% and 28% respectively. Intracellular application of H7, a potent inhibitor of PKC, abolished inhibition of IGABA by SP, suggesting that the inhibition of IGABA by SP may be a result of intracellular phosphorylation of the GABAA receptor.


Assuntos
Células Piramidais/fisiologia , Receptores de GABA-A/fisiologia , Substância P/farmacologia , Animais , Células Cultivadas , Relação Dose-Resposta a Droga , Antagonistas de Receptores de GABA-A , Potenciais da Membrana/efeitos dos fármacos , Células Piramidais/efeitos dos fármacos , Ratos , Ratos Wistar
16.
Sheng Li Xue Bao ; 50(1): 37-42, 1998 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-11324515

RESUMO

Modulation of bradykinin (BK) on ATP-activated membrane currents in the isolated rat dorsal root ganglion (DRG) neurons was investigated using whole-cell patch-clamp technique. In 56 neurons examined, BK (10(-6)-10(-4) mol/L)-induced responses were as follows: (1) inward current (40/56); (2) outward current (7/56); (3) no responses (9/56). In the majority of the neurons examined, ATP (10(-6)-10(-3) mol/L) activated a concentration-dependent inward current with obvious desensitization. ATP-activated current was potentiated markedly by preapplication of BK. The enhancement of BK was dependent on the concentration of BK and ATP. It was found that BK potentiated the peak value of ATP-activated currents predominately while the steady state value was not affected obviously. The onset of BK potentiation of ATP-activated currents needed preincubation of BK at least for 30 s and the time of the enhancement lasted over 20 min. The results suggest that BK may play a role in the facilitation of the excitatory effect of ATP on primary sensory neurons.


Assuntos
Bradicinina/farmacologia , Gânglios Espinais/citologia , Trifosfato de Adenosina/farmacologia , Animais , Separação Celular , Potenciais da Membrana , Neurônios Aferentes/efeitos dos fármacos , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley
17.
Sheng Li Xue Bao ; 48(1): 23-30, 1996 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-8758686

RESUMO

The aim of the present study was to investigate the distribution and coexistence of glutamate (Glu) receptor subtypes in the isolated rat DRG neurons as identified by the recorded NMDA-, KA- or QA/AMPA-activated current using whole-cell patch-clamp technique. Of the 37 identified neurons, 15 contain only a single subtype receptor, 13 with two kind subtype receptors, only 4 with all subtype receptors. With regard the frequency of occurrence of the three types of receptors, the NMDA, KA and QA/AMPA subtype were found present respectively in 26 (70.3%), 7 (18.9%) and 21 (56.8%) of the recorded cells.


Assuntos
Gânglios Espinais/fisiologia , Receptores de Glutamato , Animais , Animais Recém-Nascidos , Gânglios Espinais/química , Neurônios/química , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley , Receptores de AMPA/análise , Receptores de Glutamato/classificação , Receptores de Ácido Caínico/análise , Receptores de N-Metil-D-Aspartato/análise
18.
Sheng Li Xue Bao ; 46(6): 586-90, 1994 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-7533331

RESUMO

The whole-cell patch-clamp technique was used to record GABA-activated currents in freshly isolated DRG neurons. It was found that application of SP (10(-7)-10(-5) mol/L) could induce concentration dependent inward currents in some cells (4/26), while no such current was detectable in the other neurons. However, preapplication of SP could inhibit the inward currents mediated by GABAA receptor (18/22). The inhibitory effect of SP was concentration dependent and reversible, and the desensitization of GABA-activated current could also be enhanced by SP.


Assuntos
Gânglios Espinais/fisiologia , Substância P/farmacologia , Ácido gama-Aminobutírico/farmacologia , Animais , Animais Recém-Nascidos , Depressão Química , Eletrofisiologia , Neurônios/fisiologia , Ratos , Ratos Sprague-Dawley
19.
Sheng Li Xue Bao ; 46(1): 90-4, 1994 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-8085175

RESUMO

Memory impairments of passive avoidance response were observed in 38 Wistar rats with bilateral fornix-fimbria transection. After fornix-fimbria lesions the degree of performance decreased from 65.3% to 13.6% (P < 0.01). Autotransplantation of superior cervical ganglion (SCG) into bilateral dorsal hippocampi improved memory function to a considerable extent. In the end of the behavioral experiments, implanted rats were sacrificed for histofluorescence study of grafts and measurement of norepinephrine (NA) content in the hippocampus. These experiments showed that the hippocampal NA content in implanted rats was considerably higher than that in untransplanted fornix-fimbria transected rats and consequently suggested that improvement of memory function was to some extent due to supplement of monoamine transmitter by the transplanted SCG.


Assuntos
Aprendizagem da Esquiva , Gânglios Simpáticos/transplante , Hipocampo/cirurgia , Memória , Gânglio Cervical Superior , Animais , Aprendizagem da Esquiva/fisiologia , Feminino , Hipocampo/fisiopatologia , Masculino , Memória/fisiologia , Ratos , Ratos Wistar , Transplante Autólogo
20.
Zhongguo Yao Li Xue Bao ; 14(3): 285-8, 1993 May.
Artigo em Chinês | MEDLINE | ID: mdl-8237413

RESUMO

The levels of ATP, ADP, and AMP in heart, brain, and kidney suffering from 10-min ischemia after decapitation in rats were determined by a modified reverse-phase HPLC set with uv detection. The ischemic depletion of ATP was alleviated and the total amount of high energy phosphates was markedly reduced by the treatment of po cyclophosphamide 20 and 100 mg.kg-1 x 3 d. The protective effect on depleting the total amount of high energy phosphates which was better preserved than ATP in ischemic organs by cyclophosphamide was evidenced in a dose-related manner. Cyclophosphamide induced leukopenia in circulating blood. Two reasons for the anti-arrhythmic effect of cyclophosphamide are suggested: 1) the depletion of leukocyte reduced the plugging effect of neutrophil in myocardial capillaries; 2) blocking the KATP channel by elevating ATP level in myocardium.


Assuntos
Trifosfato de Adenosina/metabolismo , Encéfalo/metabolismo , Ciclofosfamida/farmacologia , Rim/metabolismo , Miocárdio/metabolismo , Animais , Isquemia Encefálica/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Isquemia/metabolismo , Rim/irrigação sanguínea , Contagem de Leucócitos/efeitos dos fármacos , Masculino , Isquemia Miocárdica/metabolismo , Ratos , Ratos Sprague-Dawley
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