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1.
Zhonghua Yu Fang Yi Xue Za Zhi ; 57(1): 43-47, 2023 Jan 06.
Artigo em Zh | MEDLINE | ID: mdl-36655256

RESUMO

This study collected epidemic data of COVID-19 in Zhengzhou from January 1 to January 20 in 2022. The epidemiological characteristics of the local epidemic in Zhengzhou High-tech Zone caused by the SARS-CoV-2 Delta variant were analyzed through epidemiological survey and big data analysis, which could provide a scientific basis for the prevention and control of the Delta variant. In detail, a total of 276 close contacts and 599 secondary close contacts were found in this study. The attack rate of close contacts and secondary close contacts was 5.43% (15/276) and 0.17% (1/599), respectively. There were 10 confirmed cases associated with the chain of transmission. Among them, the attack rates in close contacts of the first, second, third, fourth and fifth generation cases were 20.00% (5/25), 17.86% (5/28), 0.72% (1/139) and 14.81% (4/27), 0 (0/57), respectively. The attack rates in close contacts after sharing rooms/beds, having meals, having neighbor contacts, sharing vehicles with the patients, having same space contacts, and having work contacts were 26.67%, 9.10%, 8.33%, 4.55%, 1.43%, and 0 respectively. Collectively, the local epidemic situation in Zhengzhou High-tech Zone has an obvious family cluster. Prevention and control work should focus on decreasing family clusters of cases and community transmission.


Assuntos
COVID-19 , Epidemias , Humanos , SARS-CoV-2 , Incidência
2.
Zhonghua Yu Fang Yi Xue Za Zhi ; 55(10): 1196-1202, 2021 Oct 06.
Artigo em Zh | MEDLINE | ID: mdl-34706504

RESUMO

Objective: To explore the effect of long-term exposure to ambient particulate matter (PM10) on the prevalence of diabetes and fasting plasma glucose (FPG). Methods: The subjects of the study were from the baseline population of "Jinchang Cohort", and 24 285 subjects were finally included after excluding incomplete home address information and diabetic diagnosis information. The demographic characteristics, lifestyle and health status of the survey subjects were collected through questionnaire, physical examination and laboratory tests. ArcGIS software was used to match the nearest environmental monitoring stations for each subject according to residential address. Two-year average concentrations of PM10 were calculated to estimate exposure level. The logistic regression and the multiple linear regression were conducted to assess the effects of ambient PM10 on the prevalence of diabetes and FPG. The restricted cubic spline was used to quantify the dose-response relationship. Stratified analysis and effect modification analysis were also performed. Results: The age of 24 285 participants was (49.32±8.60) years, and the BMI was (24.22±6.09) kg/m2. There were 13 950 (57.44%) males and 2 066 (8.51%) diabetic patients. After adjusting for confounders, for every 10 µg/m3 increase in the average PM10 concentration in the first two years of the survey, the prevalence of diabetes increased [OR (95%CI) =1.05 (1.01-1.09)]and the FPG level elevated [ß (95%CI) = 0.061 (0.047-0.076) mmol/L]. The results of the restricted cubic spline analysis showed a nonlinear relationship between PM10 concentration and FPG level (P<0.001). Further subgroup analysis showed that female [OR (95%CI) =1.10 (1.03-1.18)], people over 50 years old [OR (95%CI) =1.06 (1.02-1.11) ], subjects with family history of diabetes [OR (95%CI) = 1.13 (1.04-1.23) ], and with hypertension [OR (95%CI) = 1.07 (1.02-1.12) ] had a stronger association between the prevalence of diabetes and PM10 exposure (all P interaction values were<0.05). The effects of PM10 on FPG were more significant in people older than 50 years[ß (95%CI) = 0.080 (0.050-0.109) mmol/L], with family history of diabetes [ß (95%CI) = 0.087 (0.036-0.137) mmol/L], and hypertension [ß (95%CI) = 0.077 (0.046-0.108) mmol/L] (all P interaction values were<0.05). Conclusions: Long-term exposure to ambient PM10 increases the diabetes prevalence and FPG. People older than 50 years old, with family history of diabetes and hypertension could be more sensitive to the effects of PM10 exposure.


Assuntos
Poluentes Atmosféricos , Diabetes Mellitus , Adulto , Poluentes Atmosféricos/análise , Glicemia/análise , Diabetes Mellitus/epidemiologia , Exposição Ambiental/análise , Jejum , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Material Particulado/análise , Prevalência
3.
Zhonghua Liu Xing Bing Xue Za Zhi ; 45(6): 852-856, 2024 Jun 10.
Artigo em Zh | MEDLINE | ID: mdl-38889986

RESUMO

Objective: To understand the epidemiological characteristics and spatiotemporal distribution of viral encephalitis in children and adolescents in Henan Province from 2012 to 2023. Methods: The information about viral encephalitis cases from October 1, 2012 to July 26, 2023 were collected from Zhengzhou Children's Hospital (National Children's Regional Medical Center),Henan Provincial Children's Hospital for the analyses on temporal distribution the cases, the severe illness rate, age distribution, pathogen type and imaging findings of the cases. Results: A total of 6 276 cases of viral encephalitis were included in this study after excluding cases with incomplete information. The cases mainly originated from Zhengzhou (38.96%), followed by Zhoukou (9.93%), Xuchang (8.68%), Zhumadian (7.90%) and Pingdingshan (7.39%). The cases in boys accounted for 62.13% and the cases in girls accounted for 37.87%. Most cases (72.45%) occurred in age group 7-13 years. The overall rate of severe illness cases was 4.51% from 2012 to 2023. There were significant differences in severe illness cases among different areas and years (χ2=5.33,P=0.021; χ2=48.14,P<0.001). Enteroviruses were mainly detected (31.57%), in which Coxsackie virus was predominant (58.37%). Imaging findings showed that cerebral hemisphere damage was most common in children and adolescents with viral encephalitis (54.93%). Conclusions: From 2012 to 2023, more cases of viral encephalitis occurred in boys in Henan. Children and adolescents aged 7-13 years were the main affected group. The prevention of enteroviruses infection, especially Coxsackie virus, needs to be strengthened. Special attention should be paid to the prevention of cerebral hemisphere damage after viral encephalitis diagnosis.


Assuntos
Encefalite Viral , Humanos , Criança , Adolescente , Encefalite Viral/epidemiologia , Encefalite Viral/virologia , Masculino , Feminino , China/epidemiologia , Pré-Escolar , Lactente , Distribuição por Idade
4.
Rev Sci Instrum ; 95(7)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-39028911

RESUMO

A space-resolved vacuum ultraviolet spectroscopy is employed to measure impurity emission profiles (500-3200 Å) on EAST. This study successfully captures C IV (1548.20 and 1550.77 Å) lines emitted from carbon ions and derives ion temperatures using Doppler broadening and a collision model based on their intensity ratios. Both the emission intensity and ion temperature profiles are determined. However, the calculated results reveal a lower temperature of around 10-20 eV with the collision model, suggesting a potential need for further correction in subsequent calculations. Furthermore, this study explores relative rotation velocities from the Doppler shift, indicating an increase in toroidal rotation velocity with applied neutral beam injection. The measured results exhibit concordance with the charge exchange recombination spectrometer data. Furthermore, during boron powder dropping discharges on EAST, B II (1623.60, 1623.79, 1623.95, 1624.02, 1624.17, and 1624.38 Å) emission lines exhibiting a similar time behavior trend with boron powder injection are identified. Ion temperatures are measured using B II (1362.46 Å) through the Doppler broadening method. These techniques hold significant promise for future impurity analysis at the edge of EAST, providing valuable insights into the behavior of carbon and boron ions.

5.
Eur Rev Med Pharmacol Sci ; 24(7): 3741-3748, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32329851

RESUMO

OBJECTIVE: The purpose of this study was to explore the role of ANXA3 in lung cancer cell resistance to oxaliplatin (OXA). MATERIALS AND METHODS: After adding different concentrations of Ox, A549, and A549/Ox cell viability were examined using cell counting kit-8 (CCK-8) assay, and the mRNA and protein expressions of ANXA3 were analyzed by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) and Western blot, respectively. After treating cells with 5 µg/mL and 15 µg/mL Ox for 24 hours and knocking down ANXA3, qRT-PCR, CCK8, flow cytometry, transwell, and BrdU assays were performed to examine ANXA3 expression level, cell viability, apoptosis, migration, and proliferative capacities, respectively. In addition, Western blot was performed to detect the protein expression of c-caspase 3. RESULTS: The higher the concentration of Ox added, the worse the cell viability. Meanwhile, ANXA3 expression in A549/Ox cells was found remarkably higher than that in normal A549 cells. After treated with different concentrations of Ox for 24 hours, the cell viability, migration capacity and cell proliferation of A549 cells were found remarkably decreased, while the opposite results were observed in cell apoptosis and C-caspase 3 protein expression, and the Ox treatment group was evidently lower than control group. CONCLUSIONS: Knockdown of ANXA3 may be able to inhibit the resistance of LCa cells to OXA.


Assuntos
Anexina A3/deficiência , Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Oxaliplatina/farmacologia , Células A549 , Anexina A3/genética , Anexina A3/metabolismo , Apoptose/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/patologia , Células Tumorais Cultivadas
6.
Zhonghua Liu Xing Bing Xue Za Zhi ; 41(10): 1601-1605, 2020 Oct 10.
Artigo em Zh | MEDLINE | ID: mdl-33297615

RESUMO

Objective: To analyze the characteristics of COVID-19 case spectrum and spread intensity in different provinces in China except Hubei province. Methods: The daily incidence data and case information of COVID-19 were collected from the official websites of provincial and municipal health commissions. The morbidity rate, severity rate, case-fatality rate, and spread ratio of COVID-19 were calculated. Results: As of 20 March, 2020, a total of 12 941 cases of COVID-19 had been conformed, including 116 deaths, and the average morbidity rate, severity rate and case-fatality rate were 0.97/100 000, 13.5% and 0.90%, respectively. The morbidity rates in Zhejiang (2.12/100 000), Jiangxi (2.01/100 000) and Beijing (1.93/100 000) ranked top three. The characteristics of COVID-19 case spectrum varied from province to province. The first three provinces (autonomous region, municipality) with high severity rates were Tianjin (45.6%), Xinjiang (35.5%) and Heilongjiang (29.5%). The case-fatality rate was highest in Xinjiang (3.95%), followed by Hainan (3.57%) and Heilongjiang (2.70%). The average spread ratio was 0.98 and the spread intensity varied from province to province. Tibet had the lowest spread ratio (0), followed by Qinghai (0.20) and Guangdong (0.23). Conclusion: The intervention measures were effective in preventing the spread of COVID-19 and improved treatment effect in China. However, there were significant differences among different regions in severity, case-fatality rate and spread ratio.


Assuntos
COVID-19/epidemiologia , Pandemias , Pequim/epidemiologia , COVID-19/mortalidade , China/epidemiologia , Humanos , Morbidade , Tibet/epidemiologia
7.
Zhonghua Liu Xing Bing Xue Za Zhi ; 41(5): 623-628, 2020 May 10.
Artigo em Zh | MEDLINE | ID: mdl-32145716

RESUMO

Since December 2019, COVID-19, a new emerging infection disease, has spread in 27 countries and regions. The clusters of many cases were reported with the epidemic progresses. We collected currently available information for 377 COVID-19 clusters (1 719 cases), excluded the hospital clusters and Hubei cases, during the period from January 1 to February 20, 2020. There were 297 family clusters (79%), case median was 4; 39 clusters of dining (10%), case median was 5; 23 clusters of shopping malls or supermarkets (6%), case median was 13; 12 clusters of work units (3%), case median was 6, and 6 clusters of transportation. We selected 325 cases to estimate the incubation period and its range was 1 to 20 days, median was 7 days, and mode was 4 days. The analysis of the epidemic situation in a department store in China indicated that there was a possibility of patients as the source of infection during the incubation period of the epidemic. From February 5 to 21, 2020, 634 persons were infected on the Diamond Princess Liner. All persons are susceptible to the 2019 coronavirus. Age, patients during the incubation period and the worse environment might be the cause of the cases rising. The progress of the two typical outbreaks clearly demonstrated the spread of the early cases in Wuhan. In conclusion, screening and isolating close contacts remained essential other than clinical treatment during the epidemic. Especially for the healthy people in the epidemic area, isolation was the key.


Assuntos
Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , COVID-19 , China/epidemiologia , Análise por Conglomerados , Humanos , Pandemias
8.
Eur Rev Med Pharmacol Sci ; 22(16): 5206-5213, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30178843

RESUMO

OBJECTIVE: To investigate the role of lncRNA PCAT6 in the progression of gastric cancer and its underlying mechanism. PATIENTS AND METHODS: Expression levels of PCAT6 in 72 gastric cancer tissues and paracancerous tissues were detected by qRT-PCR (Quantitative Real-Time Polymerase Chain Reaction). The correlation between PCAT6 expression and clinical data of gastric cancer patients was analyzed by the chi-square test. After lentivirus transfection of PCAT6 in gastric cancer cells, proliferation, apoptosis, and invasion were detected by CCK-8 (cell counting kit-8), flow cytometry, and transwell assay, respectively. Western blot was utilized to detect protein expressions of apoptosis-related and EMT-related (epithelial-mesenchymal transition) genes in gastric cancer cells. Furthermore, target genes of PCAT6 were predicted via bioinformatics method and verified by luciferase reporter gene assay. The effects of target genes on biological functions of gastric cancer cells were determined as well. RESULTS: PCAT6 was overexpressed in gastric cancer tissues than those of paracancerous tissues. PCAT6 expression was negatively correlated to prognosis, tumor size, TNM (tumor node metastasis) stage and metastasis of gastric cancer. For in vitro experiments, overexpression of PCAT6 increased proliferation, migration, and invasion, whereas decreased apoptosis of gastric cancer cells. MicroRNA-30 was predicted as the target gene of TCAT6. Furthermore, microRNA-30 was found to bind to TCAT6 via targeting MKRN3. Either microRNA-30 knockdown or PCAT6 overexpression could remarkably promote MKRN3 expression. CONCLUSIONS: PCAT6 is overexpressed in gastric cancer, which promotes the development of gastric cancer by endogenously competition with microRNA-30 via targeting MKRN3.


Assuntos
MicroRNAs/biossíntese , RNA Longo não Codificante/biossíntese , Neoplasias Gástricas/metabolismo , Idoso , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Ligação Proteica/fisiologia , RNA Longo não Codificante/genética , Neoplasias Gástricas/genética
9.
Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi ; 30(21): 1739-1741, 2016 Nov 05.
Artigo em Zh | MEDLINE | ID: mdl-29871188

RESUMO

A 71 years old male with throat discomfort, shortness of breath, irritating cough admission. Fiberoptic laryngoscope: bilateral glottis ventricular zone with about quail egg size smooth cystic masses. Throat enhanced CT: infrahyoid margin level about bilateral aryepiglottic fold inside have package containing gas shadow, communicated with the laryngeal chamber. Support laryngoscope under coblation radiofrequency ablation assisted laryngeal cyst excision were done and postoperative pathology consistent with laryngocele.

10.
FEMS Microbiol Lett ; 132(1-2): 57-60, 1995 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-7590165

RESUMO

In order to study the role of gyrB in antibiotic resistance in post-ciprofloxacin therapy fluoroquinolone-resistant clinical isolates of Salmonella typhimurium, plasmid pBP548, which contains the Escherichia coli gyrB gene, was used in complementation studies. In a heterodiploid strain, the wild-type (quinolone sensitive) allele is dominant over the resistant allele therefore, eleven clinical isolates were complemented with gyrB encoded on pBP548. Only one transformant, L18pBP548, exhibited increased susceptibility to the quinolones nalidixic acid, ciprofloxacin and sparfloxacin. The amino acid sequence of the gyrase B protein from a wild-type and the pre-therapy S. typhimurium (deduced from the nucleotide sequence) was identical to that of E. coli from codons 436 to 470; however, a point mutation was identified in codon 463 of gyrB of the quinolone-resistant post-therapy isolate L18, giving rise to an amino acid substitution of serine to tyrosine.


Assuntos
Anti-Infecciosos/farmacologia , DNA Topoisomerases Tipo II/genética , Fluoroquinolonas , Mutação , Salmonella typhimurium/genética , Sequência de Bases , Ciprofloxacina/farmacologia , DNA Girase , DNA Bacteriano/química , Resistência Microbiana a Medicamentos/genética , Humanos , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Ácido Nalidíxico/farmacologia , Quinolonas/farmacologia , Salmonella typhimurium/efeitos dos fármacos
11.
Chin Med J (Engl) ; 106(3): 167-70, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8325139

RESUMO

Serum lipids, lipoproteins, malondialdelyde (MDA) and metal levels were determined in 86 patients with coronary heart disease (CHD) proved angiographically and 33 controls subjects. Serum concentrations of TC, LDL-C, AI, MDA and Cu were significantly elevated and serum HDL-C, Zn and Mg contents were decreased markedly in patients. Correlation analyses indicated that the severity of coronary arterial lesions was related positively to serum TC, LDL-C, AI, MDA and Cu levels, and inversely to HDL-C levels; both the serum Cu and MDA contents were related positively to TC and LDL-C levels. These data suggest that serum Cu and MDA might have effects on the extent of CA lesions during the progress of atherosclerosis in patients with CHD.


Assuntos
Colesterol/sangue , Doença das Coronárias/sangue , Lipoproteínas/sangue , Oligoelementos/sangue , Feminino , Humanos , Masculino , Malondialdeído/sangue , Pessoa de Meia-Idade , Triglicerídeos/sangue
12.
Chin Med J (Engl) ; 103(5): 380-4, 1990 May.
Artigo em Inglês | MEDLINE | ID: mdl-2118054

RESUMO

A study of the relationships between serum TC, TG and HDL.C and selective coronary arteriography was carried out on 117 patients who were divided into groups according to the extent of artery stenosis. Normal control group consisted of 153 healthy subjects. There were no statistical differences in TC, TG, HDL.C, LDL.C, TC/HDL.C, LDL.C/HDL.C and TC-HDL.C/HDL.C between normal control group and the group with normal coronary arteriogram. LDL.C, TC/HDL.C, LDL.C/HDL.C, TC HDL.C/HDL.C rose and HDL.C decreased as the degree of coronary artery stenosis and the extent of stenosis increased, besides the medium and severe stenosis group. Analyses based on the correlation coefficients indicate that 3 compound indexes (TC-HDL.C/HDL.C, TC-HDL.C, LDL.C/HDL.C) are better in assessing CAD than single index such as LDL.C, HDL.C and TC. The results of our study showed that the 3 compound indexes might be regarded as important risk factors for CAD.


Assuntos
HDL-Colesterol/sangue , LDL-Colesterol/sangue , Colesterol/sangue , Angiografia Coronária , Doença das Coronárias/sangue , Adulto , Doença das Coronárias/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
13.
Yao Xue Xue Bao ; 27(6): 412-7, 1992.
Artigo em Zh | MEDLINE | ID: mdl-1442067

RESUMO

Erythropoietin (EPO) is a glycoprotein hormone secreted by human kidney cells. Human EPO was induced from human embryo kidney cells, isolated and purified from medium by biochemical method in our laboratory. The hypoproliferative anemia in chronic renal failure (CRF) has been assumed to be the result of decreased EPO production by the damaged kidney and of the shortening of the survival of erythrocytes. In this study, CRF anemia was formed 9 weeks after the removal of five-sixths of the renal mass of rats. These anemic rats were divided into 6 groups: treated with different dosages of EPO or physiological saline. The results indicate that EPO has apparent effects on anemia in rats with CRF. It may stimulate erythropoiesis and improve the anemia state of rats with CRF. Hematological parameters (RBC, Hb, PLT, Ht and Rt) may be reverted to normal levels (P less than 0.001). The level of BUN and Cr were significantly decreased. The optimum dose of EPO was 1000 U/kg. All these results show that injection of EPO has therapeutic effect on anemia in rats with CRF. EPO showed no effect on normal rats.


Assuntos
Anemia/terapia , Eritropoetina/administração & dosagem , Falência Renal Crônica/complicações , Anemia/etiologia , Animais , Relação Dose-Resposta a Droga , Eritropoetina/uso terapêutico , Feminino , Masculino , Nefrectomia/métodos , Ratos , Ratos Endogâmicos
16.
J Antimicrob Chemother ; 36(5): 845-50, 1995 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8626267

RESUMO

For wild-type bacteria the activity of biapenem was similar to that of imipenem, but for 51 imipenem-resistant strains meropenem was more active than either. When penicillin-binding protein 2a (PBP 2a) was expressed in Staphylococcus aureus biapenem had reduced activity. Mutant bacteria with decreased susceptibility to biapenem were selected in agar. Most of the mutant Gram negative bacteria were unstable and readily reverted to susceptible. The mutant Proteus vulgaris and Pseudomonas aeruginosa lacked an outer membrane protein. Biapenem-resistant S. aureus could be selected only from MRSA.


Assuntos
Bactérias Gram-Negativas/efeitos dos fármacos , Tienamicinas/farmacologia , Resistência Microbiana a Medicamentos/genética , Bactérias Gram-Negativas/genética , Imipenem/farmacologia
17.
J Antimicrob Chemother ; 43 Suppl B: 39-42, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10382874

RESUMO

The antibacterial activity of moxifloxacin, compared with that of ciprofloxacin, was determined for five strains of Staphylococcus aureus, including one NorA-overproducing strain, two quinolone-susceptible strains of Streptococcus pneumoniae, four quinolone-susceptible strains of Haemophilus influenzae, and one strain each of quinolone-susceptible Escherichia coli, Pseudomonas aeruginosa and Moraxella catarrhalis. In addition, the accumulation of moxifloxacin and ciprofloxacin by the NCTC type strain of S. pneumoniae, H. influenzae, S. aureus, E. coli and P. aeruginosa was determined by a fluorescence method. For all strains, moxifloxacin accumulated to a lower concentration than ciprofloxacin. The concentrations of moxifloxacin accumulated ranged from 12 to 44 ng/mg dry cells. The lowest concentration was accumulated by S. pneumoniae NCTC 7465 and the highest concentration by S. aureus NCTC 8532. Increased expression of norA in S. aureus had no effect on the accumulation of moxifloxacin. Despite differences in the concentration of moxifloxacin accumulated by the different species, there was little difference between the MICs of this agent for each strain (0.06-0.5 mg/L), suggesting that the concentration accumulated by wild-type bacteria has little effect on the MIC.


Assuntos
Anti-Infecciosos/farmacologia , Compostos Aza , Fluoroquinolonas , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Quinolinas , Anti-Infecciosos/farmacocinética , Ciprofloxacina/farmacologia , Escherichia coli/efeitos dos fármacos , Bactérias Gram-Negativas/metabolismo , Bactérias Gram-Positivas/metabolismo , Haemophilus influenzae/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Moraxella catarrhalis/efeitos dos fármacos , Moxifloxacina , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Streptococcus pneumoniae/efeitos dos fármacos
18.
J Antimicrob Chemother ; 31(1): 89-103, 1993 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8383105

RESUMO

The activity of six cephalosporins, six penicillins and one monobactam combined with BRL 42715, clavulanic acid, sulbactam or tazobactam at 0.1, 0.5, 1, 2, 5 and 10 mg/L was determined for 45 beta-lactamase producing Gram-negative bacteria. The combination of BRL 42715 with any of the agents was more active than any of the other inhibitor and beta-lactam combinations. Unlike the other beta-lactamase inhibitors, BRL 42715 enhanced the activity of the beta-lactams for strains that constitutively expressed Richmond & Sykes Class I beta-lactamase and against strains expressing extended-spectrum plasmid-mediated beta-lactamases.


Assuntos
Antibacterianos/farmacologia , Quimioterapia Combinada/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Lactamas , Inibidores de beta-Lactamases , beta-Lactamas , Ácido Clavulânico , Ácidos Clavulânicos/farmacologia , Inibidores Enzimáticos/farmacologia , Bactérias Gram-Negativas/enzimologia , Ácido Penicilânico/farmacologia , Sulbactam/farmacologia , Tazobactam , beta-Lactamases/metabolismo
19.
J Antimicrob Chemother ; 39(5): 609-15, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9184360

RESUMO

Two strains of Streptococcus pneumoniae, M4 (NCTC 7465, type strain) and M5 (clinical isolate), and their respective ciprofloxacin-resistant mutants, M4/C1, M5/C1 and M5/C3, were evaluated. All mutants were stable after one year's storage and all grew more slowly in Brain Heart Infusion broth than the parent. The MICs of ciprofloxacin, sparfloxacin and tosufloxacin were increased for the mutants of M4, whereas the mutants of M5 were less susceptible to ciprofloxacin only. The optimal bactericidal concentration (OBC) of each quinolone for all the strains was approximately ten-fold greater than the MIC. The OBCs for the mutants were increased for ciprofloxacin, but not for the other two quinolones. The DNA synthesis IC50 values of all quinolones correlated well with the MIC of each drug. All quinolones accumulated rapidly within all five strains; 10 mM magnesium chloride decreased the concentration of quinolone accumulated, but carbonyl cyanide m-chlorophenyl hydrazone had no effect. Mutant strains M4/C1, M5/C1 and M5/C3 accumulated less quinolone than their respective parent strains. DNA sequencing of those regions of gyrA and gyrB corresponding to the quinolone resistance-determining region in other bacteria did not reveal any differences between the parent and mutant strains.


Assuntos
Anti-Infecciosos/farmacologia , Ciprofloxacina/farmacologia , DNA Topoisomerases Tipo II/fisiologia , Streptococcus pneumoniae/efeitos dos fármacos , Sequência de Aminoácidos , Sequência de Bases , Ciprofloxacina/farmacocinética , DNA Girase , Resistência Microbiana a Medicamentos , Dados de Sequência Molecular , Streptococcus pneumoniae/crescimento & desenvolvimento
20.
J Antimicrob Chemother ; 47(3): 261-70, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11222558

RESUMO

Ten novel fluoroquinolones, with similar chemical structures but differing antibacterial activities and hydrophobicities, were studied to evaluate the role of the physical properties of quinolones on their accumulation and antibacterial activity for Staphylococcus aureus. Six of the 10 agents and tosufloxacin were more active against quinolone-susceptible and -resistant S. aureus than the remaining four agents and several piperazinyl fluoroquinolones. Changes to the side chains of the pyrollidinyl substituent at the R7 position alone made little difference to the MICs. Comparison of MICs of agents that were structurally identical apart from the R1 substituents, confirmed that a t-butyl group confers enhanced activity against S. aureus over a cyclopropyl or ethyl group at this position. The steady-state concentrations (SSCs) of the 10 novel quinolones accumulated by wild-type S. aureus did not correlate with their MICs or chemical structures. There was no apparent relationship between logP of the quinolone and accumulation by S. aureus F77; however, accumulation was positively correlated with molecular mass for 9/10 agents (r = 0.745) confirming that high molecular mass is not a barrier to accumulation in S. aureus. For all 10 agents, the presence of carbonyl cyanide m-chlorophenylhydrazone (CCCP) increased the concentration of quinolone accumulated by SA-1199, suggesting that NorA was inhibited. The fold increase of the SSC in the presence of CCCP did not correlate with hydrophobicity, but the SSC of agents with either an ethyl or cyclopropyl group at R1 was increased two- to three-fold in the presence of CCCP, suggesting that affinity for the NorA efflux pump may be influenced by quinolone structure.


Assuntos
Anti-Infecciosos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Anti-Infecciosos/química , Escherichia coli/efeitos dos fármacos , Fluoroquinolonas , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Peso Molecular , Mutação , Especificidade da Espécie , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo , Relação Estrutura-Atividade
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