Transcriptional profiling of target of RNAIII-activating protein, a master regulator of staphylococcal virulence

Staphylococcus aureus is a gram-positive bacterium that is part of the normal healthy flora but that can become virulent and cause infections by producing biofilms and toxins. The production of virulence factors is regulated by cell-cell communication (quorum sensing) through the histidine phosphorylation of target of RNAIII-activating protein (TRAP), which is a 21-kDa protein that is highly conserved among staphylococci. Using microarray analysis, we show here that the expression and phosphorylation of TRAP upregulate the expression of most, if not all, toxins known to date, as well as their global regulator agr. In addition, we show here that the expression and phosphorylation of TRAP are also necessary for the expression of genes known to be necessary for the survival of the bacteria in a biofilm, like arc, pyr, and ure. TRAP is thus demonstrated to be a master regulator of staphylococcal pathogenesis.     

Transthyretin is an inhibitor of monocyte and endothelial cell interleukin-1 production

Human serurn was found to contain an inhibitor of constitutive interleukin 1 (IL-1) production by human umbilical vein endothelial cells (ECs). Purification of the serum activity by anion exchange chromatography, molecular sieve HPLC, and hydroxyl apatite chromntography yielded material 82% pure with a molecular weight of 17 kDa by SDS-PAGE. Amino acid sequencing revealed the purified inhibitor to be transthyretin (TTR). a liver-derived protein. There was a 42.6% reduction in the production of spontaneous IL-1 activity in EC supernatants after coculture with 10g/ml TTR. TTR was subsequently found by ELISA to inhibit LPS-stimulated IL-1 production by cells of the human monocytic leukemia line THP-1 by 47.1 ± 9.4%, whereas a less striking but still significant inhibition of monocyte-derived IL-1 production was also observed. Inhibition of IL-1 secretion correlated with increased IL-1 mRNA synthesis in both THP-1 cells and monocytes. Furthermore, TTR was associated with increased intracellulaf concentrations of IL-1. These data suggest that TTR functions by inhibiting processing of newly synthesized peptide for secretion. This novel inhibitory effect of TTR on the production of IL-1 activity suggests a previously unrecognized endogenous antiinflammatory mediator.     

Laryngopharyngeal manifestations of reflux: diagnosis and therapy

Acid reflux--most often associated with heartburn--may also cause a wide range of laryngopharyngeal symptoms, including laryngitis and chronic cough. Symptoms of laryngopharyngeal reflux (LPR), like those of gastrooesophageal reflux disease, result from abnormal exposure of tissues to acid refluxate. Deranged sensorimotor function of the upper oesophageal sphincter appears to play a key role in the aetiology of LPR, but the disease is not completely understood. Among the significant long-term complications of LPR are bronchopulmonary disorders, recurrent pneumonia, chronic cough, chronic or recurrent laryngitis, and oral cavity disorders. It also appears to be a risk factor for the development of laryngeal carcinoma. Diagnosis of LPR is based on physical examination, medical history, and results of specific tests. At present, the test of choice for LPR diagnosis is intraluminal oesophageal pH monitoring. Barium contrast oesophagography, intraoesophageal acid perfusion challenge, and flexible endoscopic evaluation of swallowing with sensory testing may also be used in LPR diagnosis. Treatment for LPR includes changes to the diet and lifestyle, and acid-suppressing therapy. The Therapeutic Working Party at the First Multi-Disciplinary International Symposium on Supraesophageal Complications of Gastroesophageal Reflux Disease has recommended twice-daily dosing with a proton pump inhibitor as an initial therapy for LPR, with treatment continued between 4 weeks and 6 months. Such treatment has been found highly effective in resolving symptoms of LPR, and it may also prevent the serious long-term complications of this condition.     

The high prevalence of obstructive sleep apnea among patients with bipolar disorders

Introduction: Sleep plays an important role in maintaining stability in bipolar disorders, and sleep disturbances can trigger mood episodes. Obstructive sleep apnea (OSA) is a common sleep disorder, yet the co-occurrence with bipolar disorder has not been methodically studied. Methods: This is a chart review of 482 consecutively seen patients with a bipolar disorder who underwent routine screening for OSA using a self-report sleep apnea questionnaire. Positive screens were referred for a sleep study. Results: A positive screen was found in 214 (44.4%) patients. Sleep studies were obtained on 114 patients, and 101, were diagnosed with OSA: point prevalence 21%. Discussion: The 21% prevalence fails to consider the false negative rate of the questionnaire, or the exclusion of patients who screened positive but failed to get a sleep study. Taking these into consideration it is estimated that the true prevalence of OSA in this study may be as high as 47.5%. The co-occurrence of OSA and bipolar disorders is markedly higher than previously thought. Of note, OSA may play a role in refractory bipolar, disorders, and carries significant mortality and morbidity that overlap, with the mortality and morbidity found with bipolar disorders. Limitations: This was a retrospective study based on a self-report questionnaire. Polysomnographic confirmation was performed in only a subgroup of subjects. Conclusions: The data suggest that unrecognized OSA may play a major role in the mortality and morbidity of bipolar disorders. All patients diagnosed with a bipolar disorder should be screened with an OSA questionnaire.     

HIGH SENSITIVE PCR METHOD FOR DETECTION OF PATHOGENIC Leptospira spp. IN PARAFFIN-EMBEDDED TISSUES

This study describes the development and application of a new PCR assay for the specific detection of pathogenic leptospires and its comparison with a previously reported PCR protocol. New primers were designed for PCR optimization and evaluation in artificially-infected paraffin-embedded tissues. PCR was then applied to post-mortem, paraffin-embedded samples, followed by amplicon sequencing. The PCR was more efficient than the reported protocol, allowing the amplification of expected DNA fragment from the artificially infected samples and from 44% of the post-mortem samples. The sequences of PCR amplicons from different patients showed >99% homology with pathogenic leptospires DNA sequences. The applicability of a highly sensitive and specific tool to screen histological specimens for the detection of pathogenic Leptospira spp. would facilitate a better assessment of the prevalence and epidemiology of leptospirosis, which constitutes a health problem in many countries.     

Is it possible to make an accurate diagnosis based only on a medical history? A pilot study on women's knee joints

The purpose of this pilot study was to determine if an accurate diagnosis could be made concerning the knee joint using only the patients' medical history information. Only women were chosen for this study because of existing unpublished data on a cohort of 100 women with normal knees to act as a control (group I). From the 2,266 knee surgical procedures in the database of one surgeon, two other groups were selected. Group II was those women with only a torn medial meniscus. Group III were those women with only a torn anterior cruciate ligament (ACL). The medical history data of one half of the database were statistically analyzed to determine the questions that were the best predictors of each group. The medical history questions discovered to be best predictors were different from what might be expected from an individual surgeon's experience, expert opinion, or a medical consensus opinion panel, but the predictors did have a foundation in fact and are substantiated by statistical analyses. Using these predictors, a validation was performed on the other half of the database. When the top 142 predicting questions were used, the diagnostic accuracy was 98%; 98 of 100 of the “normal” group, 57 of 59 cases classified as having a torn meniscus, whereas 128 of 129 cases classified as having a torn ACL were correctly identified. When the only the 30 strongest predictors were used, the diagnostic accuracy was 85%: 100 of 100 cases were correctly classified as normal, 45 of 59 cases were correctly classified as having a torn meniscus, and 101 of 129 cases were correctly classified as having a torn ACL. This study demonstrated that statistical methods applied to medical historical data can make a differential clinical diagnosis of an unknown knee joint problem with high degree of accuracy and with statistical significance. In the future, computerized medical diagnostic instruments can be constructed using these statistical methods.