Preconditioning with Porphyromonas gingivalis lipopolysaccharide may confer cardioprotection and improve recovery of the electrically induced intracellular calcium transient during ischemia and reperfusion

Background and Objective: Porphyromonas gingivalis lipopolysaccharide (LPS) is a ligand for cell surface toll-like receptors (TLR), TLR2 and TLR4 while stimulation of either leads to cardioprotection. We hypothesized that: (1) pretreatment with P. gingivalis LPS at appropriate concentrations would induce cardioprotection against injury induced by ischemia and reperfusion; and (2) P. gingivalis LPS pretreatment at cardioprotective concentrations may reduce Ca2+ overload, which is a precipitating cause of injury, and improve recovery of contractile function. Material and Methods: Male Sprague-Dawley rats were randomly selected to receive intraperitoneal saline or hot phenol-water-extracted P. gingivalis LPS at 0.2, 0.5, 1.0, 2.0 or 4.0 mg/kg 24 h before the experiment. The hearts were isolated and subjected to regional ischemia by coronary artery ligation followed by reperfusion. In isolated rat ventricular myocytes, the cytosolic Ca2+ level and the electrically induced intracellular calcium (E[Ca2+]i) transient, which reflects contractile function, were determined after pretreatment with a cardioprotective dose of P. gingivalis LPS. Results: Pretreatment with 0.5 mg/kg P. gingivalis LPS significantly reduced, while pretreatment with 1.0-4.0 mg/kg significantly increased infarct size. The Ca2+ overload induced by ischemia-reperfusion was attenuated in myocytes from rats pretreated with 0.5 mg/kg P. gingivalis LPS. Pretreated myocytes also showed an increased amplitude of the E[Ca2+]i transient, no prolongation of the time to reach the peak E[Ca2+]i transient and shorter 50% decay time during reperfusion. Conclusion: At a dosage of 0.5 mg/kg, P. gingivalis LPS confers cardioprotection against ischemia-reperfusion-induced injury and improved intracellular E[Ca2+]i transient recovery, hence improving myocyte contractile recovery. © 2009 John Wiley & Sons A/S.postprin

Human papillomavirus status in southern Chinese women

1. The overall and type-specific human papillomavirus (HPV) prevalence differed between Hong Kong and Guangzhou healthy women. The prevalence of HPV was significantly higher in Guangzhou than Hong Kong women. Younger women had significantly higher risk of HPV infection. 2. HPV16 remained the most common type detected in both regions; the frequency increased with increasing disease severity. The prevalence of HPV58 and HPV52 was relatively high in women with normal cervix and precancerous lesions.published_or_final_versio

Quantitative analysis of pleural fluid cell-free DNA as a tool for the classification of pleural effusions

Background: Recently, much interest has been focused on the quantification of DNA in miscellaneous body fluids. In this study, the application is extended to classifying pleural effusions by measuring cell-free DNA in pleural fluid. Methods: We recruited 50 consecutive patients with pleural effusions with informed consent. Pleural fluids were centrifuged at 13 000g, with supernatants aliquoted for extraction and analysis of β-globin DNA sequence by quantitative real-time PCR. Serum and pleural fluid biochemistries were performed to classify pleural effusions using the modified criteria of Light et al. (Ann Intern Med 1972;77:507-13). The ROC curve was plotted to determine the cutoff DNA concentration for ciassifying pleural fluids as transudates or exudates. Indicators of diagnostic accuracy were calculated for both pleural fluid DNA and modified criteria of Light et al., using the discharge, microbiologic, and histologic diagnoses as the reference standard. Results: The area under the ROC curve was 0.95 [95% confidence interval (CI), 0.84-0.99]. At 509 genome-equivalents/mL, pleural fluid DNA alone correctly classified 46 of 50 pleural effusions with 91% sensitivity (95% CI, 76-98%), 88% specificity (95% CI, 64-98%), and positive and negative likelihood ratios of 7.7 (95% CI, 3.1-19.5) and 0.10 (95% CI, 0.04-0.27), respectively. With the modified criteria of Light et al., 43 of 50 pleural effusions were correctly classified with 97% sensitivity (95% CI, 91-100%) and 67% specificity (95% CI, 45-89%). There were significant correlations between cell-free DNA and both lactate dehydrogenase and total protein in pleural fluid, suggesting their common origin. Conclusions: Pleural fluid DNA concentrations are markedly increased in exudative effusions, making it a potential new tool to evaluate the etiologic causes of pleural effusions. © 2003 American Association for Clinical Chemistry.link_to_subscribed_fulltex

A clinical prediction rule for the severe acute respiratory syndrome [1] (multiple letters)

Multiple letters: Comment & Responseslink_to_subscribed_fulltex

Human papillomavirus infection in Southern Chinese women: a population-based study

Poster Session 36 - Inflammatory and Hormonal Factors in Relation to Cancer: abstract no. 5732Cervical cancer is a leading cause of death in women worldwide. Persistent infection of high-risk (HR) type human papillomavirus (HPV) is recognized as a necessary cause of cervical cancer. Additionally, the presence of certain predisposing factors in combination of HPV infection will significantly increase the risk of developing cervical cancer. Previous epidemiological studies showed different HPV genotype prevalence between different geographic regions. The objectives of the present study were to study and compare the prevalence and the spectrum of HPV infection in healthy women living in Hong Kong (HK) and Guangdong (GD) regions of China and the association between the potential risk factors and HPV infection. This was a cross-sectional study, and 1526 and 1300 healthy women were recruited from HK and GD, respectively. The overall and type-specific HPV prevalence were studied and compared between the two regions. The results showed that healthy women in GD with normal or abnormal cytology had significantly higher HPV prevalence (10% or 54.5%) than those in HK (6.2% or 33%, p≤0.001). The patterns of age-specific HPV prevalence were also different between the two regions. In HK, the highest HPV prevalence was in the youngest (20-30 years) and the eldest (60 and above) age groups, whereas the highest HPV prevalence in GD was observed in the youngest age group (20-30) and declined as the age increased. HPV16 and HPV52 were the most common high-risk type found in HK and GD, respectively. In HK, younger women had significantly higher risk of HPV infection, whereas lifetime number of sexual partner was strongly associated with the risk of HPV infection in GD. Lack of previous cervical screening, current smoker and having previous sexual transmitted diseases had increased risk of HPV infection for women in both regions. In summary, the overall and type-specific HPV prevalence were found different in healthy women between HK and GD. Together with the understanding of the association between the potential risk factors and HPV infection will be essential for the implementation of effective public health program for prevention of cervical cancer in Southern Chinese women.The 101st Annual Meeting of the American Association for Cancer Research (AACR), Washington, DC., 17-21 April 2010. In AACR Meeting Abstracts, 201

Massive parallel sequencing for the genetic diagnosis of rasopathies: a study of 58 Chinese patients in Hong Kong

Poster Presentatio