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ABSTRACT: Lipoteichoic acid (LTA) from Staphylococcus aureus has been demonstrated to inhibit agonist-stimulated platelet aggregation. However, its effects on platelet inflammatory mediator release and platelet-monocyte aggregation are still unclear. In the present study, LTA is examined for its anti-inflammatory properties and effects on platelet-monocyte aggregation.
Blood samples were obtained from 5 healthy volunteers who had taken no medicine in the previous 2 weeks. Washed platelets were prepared and incubated with LTA (0.5-2.0 μg/mL), then platelet aggregation, P-selectin expression, and soluble CD40L (sCD40L) release were measured by light transmission aggregometry, flow cytometry and enzyme-linked immunoassays, respectively. Platelet-monocyte aggregate formation in whole blood was measured by flow cytometry. Thrombin was used as a stimulant.
LTA dose-dependently decreased platelet aggregation from 89.32 ± 10.24% to 36.28 ± 9.01% (P < 0.05), sCD40L release from 3.28 ± 0.76 to 1.13 ± 0.45 ng/mL (P < 0.05) and surface P-selectin expression from 82.01 ± 11.20 to 22.78 ± 6.42% (P < 0.05). In human whole blood, 1.0 μg/mL LTA inhibited platelet-monocyte aggregation from 78.19 ± 10.94 to 38.24 + 8.74% (P < 0.05).
These results indicate that LTA from S. aureus can inhibit platelet-dependent inflammatory mediator release and platelet-monocyte aggregation. These findings suggest that LTA-mediated functional alteration of platelets may contribute to immune evasion of S. aureus.
Agents and Actions 04/2011; 60(8):775-82. · 1.59 Impact Factor
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ABSTRACT: Although community-acquired Staphylococcus aureus pneumonia with highly virulent Panton-Valentine leukocidin (PVL)-positive strains, a severe disease with significant lethality, is rare, especially in adult and adolescent patients, recent reports highlight that these infections are on the rise.
To describe the demographic and clinical features of reported cases of life-threatening community-acquired S. aureus pneumonia with usually PVL-positive strains in adult and adolescent patients, to evaluate the variables related to death, and to select a more appropriate antimicrobial treatment for this potentially deadly disease. Methods: We summarized all of the 92 reported cases and our case. The effect of 5 variables on mortality was measured using logistic regression.
S. aureus community-acquired pneumonia (CAP) with usually PVL-positive strains is a severe disease with significant lethality, i.e. 42.9%; a short duration of the time from the onset of symptoms to death, i.e. 5.5 ± 10.1 days, and prolonged hospital admissions, i.e. 33.2 ± 29.5 days. Seventy-three cases have been tested for the gene for PVL, and 71 strains have been found to carry the PVL gene. Logistic regression analysis showed that leucopenia (p = 0.002), influenza-like symptoms or laboratory-confirmed influenza (p = 0.011), and hemoptysis (p = 0.024) were the factors associated with death. Antibiotic therapies inhibiting toxin production were associated with an improved outcome in these cases (p = 0.007).
Physicians should pay special attention to those patients who acquired severe CAP during influenza season and have flu-like symptoms, hemoptysis, and leucopenia, and they should consider S. aureus more frequently among the possible pathogens of severe CAP. Empiric therapy for severe CAP with this distinct clinical picture should include coverage for S. aureus. Targeted treatment with antimicrobials inhibiting toxin production appears to be a more appropriate selection.
Respiration 11/2010; 81(6):448-60. · 2.26 Impact Factor
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ABSTRACT: To describe the clinical features of reported cases of community-acquired pneumonia (CAP) due to methicillin-resistant Staphylococcus aureus (MRSA), and to evaluate the risk factors related to outcome.
A systematic search of databases from January 1995 to December 2009 was performed. Baseline characteristics of survivors and non-survivors in the hospital were compared with the chi2 test for categorical variables. Variables with P<0.2 were entered in Logistic regression. Survival analysis was estimated by the Kaplan-Meier method according to use of antimicrobials inhibiting toxin production.
Fifty-two articles were identified reporting data on 74 patients, with 41.1% of total mortality, short duration of symptom onset to death [(6.1+/-11.0) days], and prolonged hospital admissions [(28.6+/-29.1) days]. Logistic regression analysis showed that influenza like symptoms (P=0.04), hemoptysis (P<0.01), leucopenia (P<0.01) were the risk factors associated with death, and using clindamycin or linezolid which could inhibit the Panton-Valentine leukocidin (PLV, P<0.01) was the factor associated with survival. Kaplan-Meier analysis indicated that the antibiotic therapies inhibiting toxin production were associated with improved outcome in these cases (chi2=21.59, P<0.01).
CAP due to MRSA is a severe disease with significant lethality. Empiric therapy of severe CAP with flu-like symptoms, hemoptysis and leucopenia should include coverage for MRSA. Targeted treatment with antimicrobials inhibiting toxin production appear to be more appropriate selection.
Zhongguo wei zhong bing ji jiu yi xue = Chinese critical care medicine = Zhongguo weizhongbing jijiuyixue 08/2010; 22(8):459-64.
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ABSTRACT: To investigate the clinical value of monitoring the serum cardiac biomarkers in patients with pulmonary thromboembolism (PTE) and secondary myocardial injury.
The serum cardiac biomarkers including aspartate aminotransferase (AST), lactate dehydrogenase (LDH), alpha-hydroxybutyrate dehydrogenase (HBDH), creatine kinase (CK), creatine kinase isoenzyme (CK-MB), cardiac tropnin I (cTnI) and myoglobin (Myo) were measured using immunochemiluminescent assays in 36 patients with PTE, who were diagnosed according to imaging findings in the recent 5 years. The measurements in concomitant non-PTE patients free of heart, liver, or kidney diseases were used as the baseline values of the biomarkers. Correlation analysis of the measurements was conducted in relation to the pulmonary embolism area, pulmonary hypertension and mortality rate.
The PTE patients exhibited significantly elevated levels of the serum cardiac biomarkers including AST (56.14-/+15.73 U/L), LDH (303.06-/+94.99 U/L), HBDH (234.67-/+87.86 U/L), CK-MB (26.19-/+12.39 U/L), CK (129.25-/+76.14 U/L), Myo (70.63-/+45.75 ng/ml), and cTnI (0.45-/+0.41 ng/ml) in comparison with the baseline values (P < 0.01). Of these biomarkers, AST and CK-MB showed a significant correlation to the mortality, cTnI was correlated to pulmonary hypertension, and Myo was correlated to pulmonary hypertension and massive pulmonary embolism.
Measurements of these serum cardiac biomarkers may serve as indicators for diagnosis of myocardial injury secondary to PTE. AST, CK-MB, cTnI, and Myo can help assess the prognosis of the patients.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 10/2008; 28(10):1853-5.
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ABSTRACT: To evaluate the clinical features, etiology, and outcome of patients over 65 years old hospitalized for community-acquired pneumonia (CAP).
A retrospective cohort analysis was performed for adult patients hospitalized with CAP in a 1000-bed teaching hospital between Jan 2002 and Jan 2006. Differences between < or = 65 yrs and > 65 yrs groups were calculated using chi(2) test.
A total of 302 patients (166 males), with a mean age of (68 +/- 21) yrs, were enrolled. Of the 216 elderly patients, 67.1% had comorbid conditions, mostly cardiovascular diseases and chronic obstructive lung disease. For the risk stratification, 175 patients were classified as IV - V according to Fine's index. The mean hospital stay was 12 days and in-hospital mortality was 12.0%. The most frequent pathogen was Streptococcus pneumoniae in elderly patients. As compared to 86 younger patients (< or = 65yrs), altered mental status, dyspnea, tachypnea and tachycardia on hospital admission were more frequent in the elderly. The etiological distribution was also different between the two groups.
CAP in elderly patients is a prevalent disease with high incidence of complications and mortality. More attention should be paid to the specific clinical manifestations of this patient population.
Zhonghua nei ke za zhi [Chinese journal of internal medicine] 11/2007; 46(10):810-4.
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ABSTRACT: The purpose of this study was to observe the bacterial infections of respiratory tract in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).
130 patients with AECOPD in outpatient department, emergency room or in wards were studied prospectively. Patients were divided into different groups according to both Anthonisen's classification and their lung function status. Sputum were cultured together with bacteria positive rate and types of AECOPD as well as the damage degree of lung function were analyzed.
Of 130 sputum samples, 50 showed positive through culture (38.5%) and 60 strains of pathogens were isolated. Predominant pathogens isolated would include Haemophilus parainfluenzae (20/60), Streptococcus pneumoniae (5/60) and Haemophilus influenzae (10/60). Positive rate of bacterial culture in type 1 AECOPD was 55.0%, higher than those of type 2 (38.3%) and type 3 (18.5%)(P = 0.01) and was increasing with the decrease of lung function of patients with AECOPD (P < 0.02).
Positive rate of bacterial culture in patients of type 1 AECOPD was the highest one. Haemophilus parainfluenzae was one of the most important pathogens in AECOPD. There seemed a correlation between positive result of bacterial culture and the severity of COPD.
Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi 05/2007; 28(5):503-6.
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Zhonghua jie he he hu xi za zhi = Zhonghua jiehe he huxi zazhi = Chinese journal of tuberculosis and respiratory diseases 06/2005; 28(5):346-8.
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ABSTRACT: To evaluate the transposed ovarian function and complications in cervical cancer patients with postoperative pelvic radiotherapy.
Sixty-two women with stage I-IIa cervical cancer were treated with radical hysterectomy and pelvic lymphadenectomy and transposition of both ovaries to paracolic gutters from 1997 to 2003 at the Cancer Hospital of Fudan University. Menopausal symptoms, levels of follicle-stimulating hormone (FSH) and E2 were evaluated to assess ovarian function.
Of 31 patients with stage IIa or poorly differentiated tumor or tumor > or = 2 cm in diameter, preoperative vaginal radiation was employed to deliver a dose of 15 Gy at point A. Postoperative pelvic radiation was performed in 15 patients. Totally 20% (6/30) of patients undergoing ovaries transposition without any radiation experienced ovarian failure within a mean of 15.7 months. In 35% (6/17) of patients with preoperative vaginal radiation, ovarian failure occurred within a mean of 12.0 months. When patients receiving postoperative pelvic radiation and ovaries transposition were considered together, 64% (9/14) experienced ovarian failure within a mean of 9.2 months (P < 0.05). Only 2 (3%) patients had cysts in transposed ovaries not requiring further surgery. There was no metastasis of the ovaries.
Lateral ovarian transposition is safe to patients with early stage cervical cancer. Both pre- and post-operative radiation significantly damages the ovarian function. Even ovaries transposition procedure also reduces the effectiveness.
Zhonghua fu chan ke za zhi 04/2005; 40(4):220-2.
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Xiao-Qing Qiu,
He Wang,
Xiao-Fong Lu,
Jie Zhang,
Sheng-Fu Li,
Gang Cheng,
Lin Wan,
Li Yang,
Jun-Yong Zuo, Yu-Qi Zhou,
Hai-Yun Wang,
Xin Cheng,
Su-Hua Zhang,
Zheng-Rong Ou,
Zi-Cheng Zhong,
Jing-Qiu Cheng,
You-Ping Li,
George Y Wu
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ABSTRACT: We constructed a peptide consisting of a staphylococcal AgrD1 pheromone fused to the channel-forming domain of colicin Ia and named it pheromonicin. This fusion peptide had bactericidal effects against methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA, respectively), but not against Staphylococcus epidermidis or Streptococcus pneumoniae. Growth rates, vital staining and colony forming unit (CFU) counts showed that pheromonicin did not merely suppress growth but killed S. aureus cells. The specificity of pheromonicin was shown by the absence of bactericidal effects against an accessory gene regulator (agr) locus knockout of S. aureus, and a dose-dependent inhibition of the bactericidal effects of pheromonicin by competition with corresponding free AgrD pheromone. In vivo, all pheromonicin-treated mice survived administration of MRSA that was lethal to controls. No toxicity was detectable in human liver or renal cells in culture, or in livers, kidneys or spleens of pheromonicin-treated mice. The results suggest that these types of chimeric peptides may be of value as antibiotics against specific bacterial infections.
Nature Biotechnology 01/2004; 21(12):1480-5. · 23.27 Impact Factor
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Xiao-Qing Qiu,
He Wang,
Xiao-Fong Lu,
Jie Zhang,
Sheng-fu Li,
Gang Cheng,
Lin Wan,
Li Yang,
Jun-Yong Zuo, Yu-Qi Zhou,
Hai-Yun Wang,
Xin Cheng,
Su-Hua Zhang,
Zheng-Rong Ou,
Zi-Cheng Zhong,
Jing-Qiu Cheng,
You-ping Li,
George Y Wu