Glucose repression of the Escherichia coli sdhCDAB operon, revisited: regulation by the CRP·cAMP complex

Expression of the Escherichia coli sdhCDAB operon encoding the succinate dehydrogenase complex is regulated in response to growth conditions, such as anaerobiosis and carbon sources. An anaerobic repression of sdhCDAB is known to be mediated by the ArcB/A two-component system and the global Fnr anaerobic regulator. While the cAMP receptor protein (CRP) and Cra (formerly FruR) are known as key mediators of catabolite repression, they have been excluded from the glucose repression of the sdhCDAB operon. Although the glucose repression of sdhCDAB was reported to involve a mechanism dependent on the ptsG expression, the molecular mechanism underlying the glucose repression has never been clarified. In this study, we re-examined the mechanism of the sdhCDAB repression by glucose and found that CRP directly regulates expression of the sdhCDAB operon and that the glucose repression of this operon occurs in a cAMP-dependent manner. The levels of phosphorylated enzyme IIA(Glc) and intracellular cAMP on various carbon sources were proportional to the expression levels of sdhC-lacZ. Disruption of crp or cya completely abolished the glucose repression of sdhC-lacZ expression. Together with data showing correlation between the intracellular cAMP concentrations and the sdhC-lacZ expression levels in several mutants and wild type, in vitro transcription assays suggest that the decrease in the CRP·cAMP level in the presence of glucose is the major determinant of the glucose repression of the sdhCDAB operon

Molecular cloning of the Ecotin gene in Escherichia coli

AbstractThe nucleotide sequence of a 876 bp region in E. coli chromosome that encodes Ecotin was determined. The proposed coding sequence for Ecotin is 486 nucleotides long, which would encode a protein consisting of 162 amino acids with a calculated molecular weight of 18 192 Da. The deduced primary sequence of Ecotin includes a 20-residue signal sequence, cleavage of which would give rise to a mature protein with a molecular weight of 16 099 Da. Ecotin does not contain any consensus reactive site sequences of known serine protease inhibitor families, suggesting that Ecotin is a novel inhibitor

Could Fractional Exhaled Nitric Oxide Test be Useful in Predicting Inhaled Corticosteroid Responsiveness in Chronic Cough? A Systematic Review

© 2016 Background Fractional exhaled nitric oxide (FENO) is a safe and convenient test for assessing T H 2 airway inflammation, which is potentially useful in the management of patients with chronic cough. Objective To summarize the current evidence on the diagnostic usefulness of FENO for predicting inhaled corticosteroid (ICS) responsiveness in patients with chronic cough. Methods A systematic literature review was conducted to identify articles published in peer-reviewed journals up to February 2015, without language restriction. We included studies that reported the usefulness of FENO (index test) for predicting ICS responsiveness (reference standard) in patients with chronic cough (target condition). The data were extracted to construct a 2 × 2 accuracy table. Study quality was assessed with Quality Assessment of Diagnostic Accuracy Studies 2. Results We identified 5 original studies (2 prospective and 3 retrospective studies). We identified considerable heterogeneities in study design and outcome definitions, and thus were unable to perform a meta-analysis. The proportion of ICS responders ranged from 44% to 59%. Sensitivity and specificity ranged from 53% to 90%, and from 63% to 97%, respectively. The reported area under the curve ranged from abou t 0.60 to 0.87; however, studies with a prospective design and a lower prevalence of asthma had lower area under the curve values. None measured placebo effects or objective cough frequency. Conclusions We did not find strong evidence to support the use of FENO tests for predicting ICS responsiveness in chronic cough. Further studies need to have a randomized, placebo-controlled design, and should use validated measurement tools for cough. Standardization would facilitate the development of clinical evidence

Easy Diagnosis of Asthma: Computer-Assisted, Symptom-Based Diagnosis

Diagnosis of asthma is often challenging in primary-care physicians due to lack of tools measuring airway obstruction and variability. Symptom-based diagnosis of asthma utilizing objective diagnostic parameters and appropriate software would be useful in clinical practice. A total of 302 adult patients with respiratory symptoms responded to a questionnaire regarding asthma symptoms and provoking factors. Questions were asked and recorded by physicians into a computer program. A definite diagnosis of asthma was made based on a positive response to methacholine bronchial provocation or bronchodilator response (BDR) testing. Multivariate logistic regression analysis was used to evaluate the significance of questionnaire responses in terms of discriminating asthmatics. Asthmatic patients showed higher total symptom scores than non-asthmatics (mean 5.93 vs. 4.93; p<0.01). Multivariate logistic regression analysis identified that response to questions concerning the following significantly discriminated asthmatics; wheezing with dyspnea, which is aggravated at night, and by exercise, cold air, and upper respiratory infection. Moreover, the presence of these symptoms was found to agree significantly with definite diagnosis of asthma (by kappa statistics). Receiver-operating characteristic curve analysis revealed that the diagnostic accuracy of symptom-based diagnosis was high with an area under the curve of 0.647±0.033. Using a computer-assisted symptom-based diagnosis program, it is possible to increase the accuracy of diagnosing asthma in general practice, when the facilities required to evaluate airway hyperresponsiveness or BDR are unavailable

Perception of Long-Term Oxygen Therapy for Chronic Lung Diseases May Affect Poor Adherence in Korea

Background Long-term oxygen therapy (LTOT) improves the survival of patients with hypoxemia due to chronic respiratory diseases. The clinical outcomes of LTOT are strongly associated with patient adherence. To improve the adherence of patients, physicians have focused on the efficacy of LTOT. However, poor adherence may stem from patients’ perceptions of LTOT. Herein we evaluated patients’ perceptions of LTOT affecting adherence. Methods We conducted a cross-sectional survey study using descriptive, open, and closed-ended questionnaire. Patients using oxygen therapy (OT) or requiring it but avoiding OT responded to the questionnaires at three university hospitals. Results Seventy-nine patients responded to the questionnaires. The number of patients using home and portable OT was 69 (93%) and 37 (46.3%), respectively. Patients with good adherence were 22 (30.1%). Among patients with good adherence, 90.9% used oxygen according to physicians’ prescriptions whereas only 37.3% of those with poor adherence followed physicians’ prescriptions (p<0.01). The reasons for avoiding using home OT were fear of permanent use (50%), unwanted attention (40%), and lack of symptoms (40%). They avoided portable OT because of unwanted attention (39%), heaviness (31.7%), and lack of symptoms (21.6%). Conclusion Patients on LTOT had the perception of the misunderstanding the effects of OT and of psychosocial barriers to initiate or use LTOT. Considering these findings, health professionals need to provide effective education on the purpose of LTOT to improve patient adherence to OT and provide sufficient support for the management of psychosocial barriers in patients using LTOT

A Case of Hypertrophic Osteoarthropathy Associated with Epithelioid Hemangioendothelioma

Epithelioid hemangioendothelioma is a rare vascular tumor, which occurs in the lung, liver, bone, and soft tissue. Hypertrophic osteoarthropathy is a syndrome characterized by subperiosteal new bone formation, joint effusion and clubbing, and may be associated with cyanotic heart disease, chronic pulmonary disease, liver disease, and other miscellaneous diseases. The activation of endothelium and platelets has been suggested to be involved in the development of hypertrophic osteoarthropathy. We report a rare case of hypertrophic osteoarthropathy, which developed in association with hepatic epithelioid hemangioendothelioma with pulmonary metastasis. We also discuss the role of vascular endothelial growth factor in its pathogenesis

Inhibition of histone deacetylase 6 suppresses inflammatory responses and invasiveness of fibroblast-like-synoviocytes in inflammatory arthritis

Background To investigate the effects of inhibiting histone deacetylase (HDAC) 6 on inflammatory responses and tissue-destructive functions of fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA). Methods FLS from RA patients were activated with interleukin (IL)-1β in the presence of increasing concentrations of M808, a novel specific HDAC6 inhibitor. Production of ILs, chemokines, and metalloproteinases (MMPs) was measured in ELISAs. Acetylation of tubulin and expression of ICAM-1 and VCAM-1 were assessed by Western blotting. Wound healing and adhesion assays were performed. Cytoskeletal organization was visualized by immunofluorescence. Finally, the impact of HDAC6 inhibition on the severity of arthritis and joint histology was examined in a murine model of adjuvant-induced arthritis (AIA). Results HDAC6 was selectively inhibited by M808. The HDAC6 inhibitor suppressed the production of MMP-1, MMP-3, IL-6, CCL2, CXCL8, and CXCL10 by RA-FLS in response to IL-1β. Increased acetylation of tubulin was associated with decreased migration of RA-FLS. Inhibiting HDAC6 induced cytoskeletal reorganization in RA-FLS by suppressing the formation of invadopodia following activation with IL-1β. In addition, M808 tended to decrease the expression of ICAM-1 and VCAM-1. In the AIA arthritis model, M808 improved the clinical arthritis score in a dose-dependent manner. Also, HDAC6 inhibition was associated with less severe synovial inflammation and joint destruction. Conclusion Inhibiting HDAC6 dampens the inflammatory and destructive activity of RA-FLS and reduces the severity of arthritis. Thus, targeting HDAC6 has therapeutic potential.This study was supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number:HI14C1277); the Ministry of Science, ICT and Future Planning (NRF2020M3E5E2037430, 2019M3A9A8065574); and the Chong Kun Dang Pharmaceutical Corp. TP was supported by the DFG (FOR2722)

Easy diagnosis of asthma: computer-assisted, symptom-based diagnosis

Diagnosis of asthma is often challenging in primary-care physicians due to lack of tools measuring airway obstruction and variability. Symptom-based diagnosis of asthma utilizing objective diagnostic parameters and appropriate software would be useful in clinical practice. A total of 302 adult patients with respiratory symptoms responded to a questionnaire regarding asthma symptoms and provoking factors. Questions were asked and recorded by physicians into a computer program. A definite diagnosis of asthma was made based on a positive response to methacholine bronchial provocation or bronchodilator response (BDR) testing. Multivariate logistic regression analysis was used to evaluate the significance of questionnaire responses in terms of discriminating asthmatics. Asthmatic patients showed higher total symptom scores than non-asthmatics (mean 5.93 vs. 4.93; p<0.01). Multivariate logistic regression analysis identified that response to questions concerning the following significantly discriminated asthmatics; wheezing with dyspnea, which is aggravated at night, and by exercise, cold air, and upper respiratory infection. Moreover, the presence of these symptoms was found to agree significantly with definite diagnosis of asthma (by kappa statistics). Receiver-operating characteristic curve analysis revealed that the diagnostic accuracy of symptom-based diagnosis was high with an area under the curve of 0.647 +/- 0.033. Using a computer-assisted symptom-based diagnosis program, it is possible to increase the accuracy of diagnosing asthma in general practice, when the facilities required to evaluate airway hyperresponsiveness or BDR are unavailable

A Case of Renal Crisis in a Korean Scleroderma Patient with Anti-RNA polymerase I and III Antibodies

Scleroderma (SSc) renal crisis has been reported to be associated with anti-RNA polymerase I and III (RNAP I/III) antibodies in Caucasians and the Japanese. However, no report is available for Korean SSc patients. Here, we describe the case of a 65-yr-old female SSc patient who developed renal crisis and whose serum contained anti-RNAP I/III antibodies. She was finally diagnosed as having diffuse cutaneous SSc based on skin thickening proximal to the elbows and knees. Sudden hypertension, oliguria, and pulmonary edema were features of her renal crisis. Despite the use of captopril and adequate blood pressure control, her renal function deteriorated. Subsequent renal biopsy findings showed severe fibrinoid necrosis with luminal obliteration in interlobar arteries and arterioles consistent with SSc renal crisis. Serum anti-RNAP I/III antibodies were detected by radioimmunoprecipitation. This is the first report of a renal crisis in a Korean SSc patient with RNAP I/III antibodies