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1.
Nat Commun ; 9(1): 3398, 2018 08 23.
Artículo en Inglés | MEDLINE | ID: mdl-30139996

RESUMEN

Streptococcus pneumoniae evades C3-mediated opsonization and effector functions by expressing an immuno-protective polysaccharide capsule and Factor H (FH)-binding proteins. Here we use super-resolution microscopy, mutants and functional analysis to show how these two defense mechanisms are functionally and spatially coordinated on the bacterial cell surface. We show that the pneumococcal capsule is less abundant at the cell wall septum, providing C3/C3b entry to underlying nucleophilic targets. Evasion of C3b deposition at division septa and lateral amplification underneath the capsule requires localization of the FH-binding protein PspC at division sites. Most pneumococcal strains have one PspC protein, but successful lineages in colonization and disease may have two, PspC1 and PspC2, that we show affect virulence differently. We find that spatial localization of these FH-recruiting proteins relative to division septa and capsular layer is instrumental for pneumococci to resist complement-mediated opsonophagocytosis, formation of membrane-attack complexes, and for the function as adhesins.


Asunto(s)
Proteínas Bacterianas/metabolismo , División Celular , Complemento C3b/metabolismo , Factor H de Complemento/metabolismo , Streptococcus pneumoniae/citología , Streptococcus pneumoniae/metabolismo , Células A549 , Secuencia de Aminoácidos , Cápsulas Bacterianas/metabolismo , Proteínas Bacterianas/química , Adhesión Celular , Complejo de Ataque a Membrana del Sistema Complemento/metabolismo , Células Epiteliales/citología , Células Epiteliales/metabolismo , Humanos , Modelos Biológicos , Mutación/genética , Proteínas Opsoninas/metabolismo , Fagocitosis , Unión Proteica , Señales de Clasificación de Proteína , Streptococcus pneumoniae/ultraestructura
2.
J Clin Diagn Res ; 10(8): FC01-4, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27656459

RESUMEN

INTRODUCTION: Pharmacovigilance (PV) is related to detection, assessment, understanding and prevention of Adverse Drug Reactions (ADRs) which are incurred when drug is made available in the market and used in different physiological conditions. In many countries, ADRs ranks among the top ten leading cause of morbidity and mortality. There is a lack of formal culture for monitoring and reporting of ADRs in India, with ADR reporting rate being only 1% as compared to 5% in world. This type of academic detailing activity helps to create awareness of ADR reporting in the institutions. AIM: This study was planned to evaluate and analyse the incidence and patterns of ADRs in various inpatient and outpatient departments of hospital. MATERIALS AND METHODS: This was an observational, retrospective and record based study conducted by analysing the spontaneous ADR forms, collected over a period of 12 months (September 2014 to August 2015) at Indira Gandhi Institute of Medical Sciences, Patna, Bihar, India. RESULTS: During the period of one year, 292 ADR forms were collected from 4,34,965 patients attending OPD and inpatients of the hospital. Incidence of ADR was 0.67 per thousand patients and average of around 24 ADR collected per month. Male:Female ratio was 1.30. Adolescent (16-30 yr) was the most common age group affected. Department of Skin and VD reported the maximum number of ADRs (33.22%), followed by the Departments of Oncology (18.84%). Antibiotics were the most common drug implicated followed by anticancer drugs. CONCLUSION: ADR reporting is an ongoing and continuous process. Studies from the institute helps to identify and rectify the problems related to ADR reporting. Pitfalls can be addressed by creating awareness among physicians and the patients to achieve finally the goal of Pharmacovigilant India.

3.
J Clin Diagn Res ; 10(2): FC01-5, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27042479

RESUMEN

INTRODUCTION: Skin diseases are the major contributors of disease burden in society. It affects individuals of all ages, neonates to elderly. Owing to its chronic nature, it causes serious impact on quality of life and financial status of the sufferer and his family. The problem gets compounded with the inappropriate and irrational use of medicines. Periodic prescription audit in form of drug utilization study is a way to improve the quality of prescription and curb the menace of irrational prescribing which has become a global phenomenon. AIM: This study aims to determine the drug utilization pattern and assess the economic burden of the patient with skin disease. MATERIALS AND METHODS: It was a prospective, cross-sectional study conducted over a period of three months from January to March 2015 in newly diagnosed cases attending outpatient department of Skin and VD, IGIMS, Patna. The prescriptions were analysed with the help of descriptive statistics and results were expressed in percentage. RESULTS: Total 752 prescriptions were analysed during the study. Male patients were lesser as compared to female as male to female ratio was 0.88. Over 50% of patients were in adolescent age group i.e. 21-40 years. Acne (17.95%) was most common disease in the study population followed by eczema and Dermatophytosis. Among the drugs, antihistaminics (24.13%) were prescribed most frequently followed by antifungals and antibiotics. Topical agents constituted almost 60% of the total prescription and average number of drugs per prescription was 5.13, irrespective of the dosage forms prescribed. CONCLUSION: This drug utilization study provides an insight to the prescriber regarding various issues related to polypharmacy, cost analysis and prevalent disease pattern in the region. This study also suggests periodic evaluation of prescription pattern to monitor and improve quality of prescription in other departments of the hospital.

4.
J Biol Chem ; 285(45): 34309-18, 2010 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-20814030

RESUMEN

The PhoP and PhoR proteins from Mycobacterium tuberculosis form a highly specific two-component system that controls expression of genes involved in complex lipid biosynthesis and regulation of unknown virulence determinants. The several functions of PhoP are apportioned between a C-terminal effector domain (PhoPC) and an N-terminal receiver domain (PhoPN), phosphorylation of which regulates activation of the effector domain. Here we show that PhoPN, on its own, demonstrates PhoR-dependent phosphorylation. PhoPC, the truncated variant bearing the DNA binding domain, binds in vitro to the target site with affinity similar to that of the full-length protein. To complement the finding that residues spanning Met(1) to Arg(138) of PhoP constitute the minimal functional PhoPN, we identified Arg(150) as the first residue of the distal PhoPC domain capable of DNA binding on its own, thereby identifying an interdomain linker. However, coupling of two functional domains together in a single polypeptide chain is essential for phosphorylation-coupled DNA binding by PhoP. We discuss consequences of tethering of two domains on DNA binding and demonstrate that linker length and not individual residues of the newly identified linker plays a critical role in regulating interdomain interactions. Together, these results have implications for the molecular mechanism of transmission of conformation change associated with phosphorylation of PhoP that results in the altered DNA recognition by the C-terminal domain.


Asunto(s)
Proteínas Bacterianas/metabolismo , Proteínas de Unión al ADN/metabolismo , Mycobacterium tuberculosis/metabolismo , Mycobacterium tuberculosis/patogenicidad , Regiones Promotoras Genéticas , Factores de Virulencia/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Bacteriano/metabolismo , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/genética , Lípidos/biosíntesis , Lípidos/genética , Mycobacterium tuberculosis/química , Mycobacterium tuberculosis/genética , Fosforilación , Unión Proteica , Estructura Terciaria de Proteína , Factores de Virulencia/química , Factores de Virulencia/genética
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