NMR structure analysis and identification of the DNA binding site of the C-terminal domain of the Bacillus subtilis protein DnaD.

The B. subtilis protein DnaD is an essential component of the chromosome replication machinery and a global regulator of DNA architecture, as it exhibits a unique DNA remodeling activity that opens up supercoiled DNA by forming higher order nucleoprotein structures. There are no homologues of this protein in gram negative bacteria and details of its molecular structure are at present limited to the crystal structures of the N-terminal domain from B. subtilis and G. Kaustophilus, and also crystal structures of the C-terminal domain of two proteins with unknown function from S. mutans and E. faecalis (Structural Genomics projects pdb codes 2zc2 and 2i5u respectively). In this thesis, the determination of the NMR structure for the DNA binding C-terminal domain of the B. sllbtilis DnaD protein is reported. This domain is composed of five helices and an unstructured C-terminal tail, helix I-IV form a well packed hydrophobic core and helix V, which is more extensive than assumed from sequence alignments, extends away from this core fold of the protein. NMR DNA titrations, in vitro mutagenesis and in vivo complementation experiments show that a highly conserved YxxxIxxxW motif, the final helix and a portion of the mobile Cterminal region make up the DNA binding module of B. subtilis DnaD and are all essential for cell viability. Sequence alignments of DnaD alone fail to identify two key elements of this DNA binding module, the poorly conserved sequences of the final helix and the C-terminal mobile segment. Sensitive Hidden Markov Models based techniques, show that the two structural domains found in DnaD are present in B. subtilis DnaB, a primosomal protein that also participates in replication initiation. Furthermore, these two proteins share the only strong sequence motif, the highly conserved YxxxIxxxW sequence that contributes to DNA binding

Chemical characterisation of humic-like substances from urban, rural and tropical biomass burning environments using liquid chromatography with UV/vis photodiode array detection and electrospray ionisation mass spectrometry

Humic-like substances (HULIS) are ubiquitously present in the troposphere and make up a major fraction of continental fine-sized water-soluble organic compounds. They are regarded as material with strong polar, acidic and chromophoric properties; however, structural information at the individual component level is rather limited. In the present study, we have characterised HULIS from different locations using liquid chromatography coupled to photodiode array detection and negative ion electrospray ionisation mass spectrometry. Aerosol samples with particles less than 2.5 mu mm in diameter (PM2.5) were collected in Budapest and K-puszta, Hungary, during 2007 and 2008 spring and summer periods, and in Rondonia, Brazil, during a 2002 biomass burning experiment. Major components of the Budapest 2007 and Brazil 2002 HULIS corresponded to chromophoric substances, of which 4-nitrocatechol (molecular weight (MW) 155) was identified as the most abundant organic species and less abundant ones were attributed to mono-and dimethyl nitrocatechols (MWs 169 and 183). The mass concentrations of 4-nitrocatechol in the water-soluble organic carbon (WSOC) of the Budapest 2007 and day-and night-time Brazil 2002 HULIS were 0.46, 0.50 and 1.80 %. Abundant components of K-puszta 2008 HULIS were assigned to alpha-pinene secondary organic aerosol (SOA) tracers, i.e. 3-methyl-1,2,3-butanetricarboxylic acid and terpenylic acid; their mass concentrations in the HULIS WSOC were 0.75 and 0.40 %. Tere- and ortho-phthalic acids (MW 166) were major components of the Budapest and K-puszta HULIS, but only minor ones of the Brazil 2002 biomass burning HULIS, consistent with a source that is different from biomass burning and likely related to open waste burning of phthalate ester-containing material such as plastic

Contribution from selected organic species to PM2.5 aerosol during a summer field campaign at K-Puszta, Hungary

A summer field campaign was conducted at the forested background site of K-puszta in Hungary. The main aim was to assess the contribution of terpene-derived particulate organic compounds to the PM2.5 organic carbon (OC) and of the secondary organic carbon (SOC) from -pinene to the OC. The study lasted from 24 May to 29 June 2006; the first half the weather was cold, while the second half was warm. Separate daytime and night-time PM2.5 samples were collected with a high-volume sampler and the samples were analysed by several analytical techniques, including ion chromatography (IC) and liquid chromatography-mass spectrometry (LC/MS). The latter technique was used for measuring the terpene-derived species. Ancillary high time resolution measurements of volatile organic compounds (VOCs) were made with proton-transfer reaction-mass spectrometry. The temporal and diurnal variability of the particulate compounds and VOCs and interrelationships were examined. It was found that the monoterpenes and a number of terpene-derived particulate compounds, such as cis-pinic and cis-caric acid, exhibited a strong day/night difference during the warm period, with about 10 times higher levels during the night-time. During the warm period, the IC compounds and LC/MS compounds accounted, on average, for 3.1% and 2.0%, respectively, of the OC, whereas the contribution of SOC from -pinene to the OC was estimated at a minimum of 7.1%

Clinical Utility of N-Terminal Prohormone B-Type Natriuretic Peptide Levels in Patients of Type 2 Diabetes Mellitus with Heart Failure

Objective: To evaluate the effect of type 2 diabetes mellitus on plasma N-terminal prohormone B-type natriuretic peptide levels in patients with heart failure and correlate it with glycosylated haemoglobin levels. Study Design: Comparative cross-sectional study. Place and Duration of Study: Department of Chemical Pathology in collaboration with the Department of Cardiology,Combined Military Hospital, Multan Pakistan, from Feb to Sep 2021. Methodology: We assayed plasma NT-pro BNP levels in 194 individuals with established heart failure, (98 non-diabetics, and 96 patients with diabetes). Plasma NT-pro BNP levels were compared between groups in addition, the correlation of glycosylated haemoglobin with plasma NT-pro BNP levels was explored. Results: The mean plasma NT-pro BNP values were higher in patients with diabetes (15826.08 ±8143.434pg/mL) than in nondiabetics (12534.06±6323.92pg/mL) with a p-value 0.02. When NT-pro BNP was compared there was no significant found difference between the non-diabetic group and the Controlled Diabetes-Group (p-value 0 .882), but it was significantly higher in the Uncontrolled Diabetes-Group (p-value<0.001). A moderate positive association was found between NT-pro BNP and glycosylated haemoglobin (r=0.541, p-value<0.001). Conclusion: Although obesity has an inverse relation with plasma natriuretic peptides level and most patients with diabetes are overweight, the plasma NT-pro BNP is still a very informative tool and holds its significance as a diagnostic and prognosis marker in diabetic patients with heart failure

Characterization of secondary organic aerosols in the atmosphere by using mass spectrometric approaches

Les aérosols organiques secondaires (SOA) représentent une fraction importante des aérosols ambiants dans la troposphère. La composition chimique des SOA est très mal connue : elle dépend des différents processus physiques et chimiques qui affectent les composés organiques volatils biogéniques et anthropiques dans l'atmosphère. Les recherches effectuées dans le cadre de cette thèse se focalisent sur la caractérisation des SOA produits par différentes réactions sous diverses conditions atmosphériques à l aide de la spectrométrie de masse. Dans une première partie, la formation d oligome res en phase aqueuse dans l'atmosphère d'un composé majeur de la photo-oxydation atmosphérique, le méthylglyoxal, a été étudiée afin d explorer une nouvelle voie de production des SOA dans les nuages pendant la nuit. Une seconde étude porte sur la caractérisation chimique des aérosols marins. L acide méthanesulfonique est le composé organique majoritaire dans la fraction fine des aérosols. Une troisième étude concerne la caractérisation structurale d un composé dimérique a- et b-pinène de haute masse moléculaire. L'acide diaterpénylique a été proposé comme un monomère clé pour les dimères de type ester. Une quatrième étude porte sur la caractérisation chimique, par fragmentation, des principaux acides terpéniques dans les aérosols ambiants d'un site rural. L'accent est mis sur la différenciation des acides terpénique isomères, qui sont présents dans les aérosols des forêts, par spectrométrie de masse. Cette thèse présente les résultats sur la caractérisation des aérosols à partir d'un large éventail de composés organiques parents dans une variété de conditions atmosphériques.Secondary organic aerosol (SOA) accounts for a significant fraction of ambient tropospheric aerosol. The chemical composition of SOA is highly uncertain as it depends on different ongoing chemical and physical processes of biogenic volatile organic compounds (BVOC) and anthropogenic volatile organic compounds in the atmosphere. The research performed within the frame of this doctoral thesis is focused on the characterization of SOA produced from BVOC under a variety of atmospheric reactions resorting to mass spectrometric approaches. In a first study, the aqueous-phase oligomer formation of a major atmospheric photooxidation product, i.e., methylglyoxal, has been investigated to explore an additional pathway producing SOA through cloud processes during night-time. A second study deals with the chemical characterization (sulfate and organic matter) of marine aerosols. methanesulfonic acid was the dominating organic compound in in the fine size fraction of aerosol. A third study concerns the structural characterization of a dimeric a- and b-pinene SOA product. It is proposed that diaterpenylic acid is a key monomeric unit for dimers of the ester type. A fourth study deals with the chemical characterization by fragmentation of major terpenoic acids in ambient fine aerosols from a rural site. Emphasis is given to the mass spectrometric differentiation of isobaric terpenoic acids that occur in fine forest aerosol. This thesis presents results on aerosol characterization from a wide range of parent organic compounds under a variety of atmospheric conditions.NICE-BU Sciences (060882101) / SudocSudocFranceF

ESTIMATION OF ENDOCRINE DISRUPTING CHEMICALS (EDCS) LEACHING FROM BABY FEEDING BOTTLES AVAILABLE IN LOCAL MARKETS OF PAKISTAN

Endocrine disrupting chemicals (EDCs) are the exogenous substances that mimic the natural hormones and at certain doses, can interfere with the endocrine in mammals. These disruptors cause obesity, early puberty in diabetes, hormone-sensitive cancers in females, prostate cancer in males, thyroid dysfunctions, and also cause problems in neuro development and neuro endocrine systems [1]. &nbsp;One of the common endocrine disrupting chemicals is Bisphenol A, that is potentially released form plastic made from polycarbonate. It increases the risk of obesity [2], type 2 diabetes, hyper tension [3], breast cancer, coronary heart disease [4] etc. In Pakistan, various brands of feeding bottles used are made from polycarbonate; hence raise many concerns about various health issues due to migration of BPA from feeding bottles to infants. No study has so far taken on estimation of these estrogen active compounds leaching from baby bottles in Pakistan. Present study was launched, to quantify migration levels of BPA from feeding bottles from registered companies of Pakistan. First step, contains the extraction of BPA and phthalates from the feeders and the second step, involves the analysis and quantification. High levels of BPA were found leaching from different baby feeding bottles

Clinicoepidemiological and mycological study of tinea capitis in the pediatric population of Kashmir valley: A study from a tertiary care centre

Background: Tinea capitis is a superficial fungal infection that predominantly affects the pediatric population. The etiological factors vary from region to region, and the exact incidence remains obscure. The clinicoepidemiological and mycological aspects of this dermatophytosis were studied in a tertiary care centre in Kashmir valley. Aim: To determine the clinicoepidemiological aspects and mycological findings of dermatophytes involved in tinea capitis cases in Kashmir valley. Materials and Methods: Wood's lamp examination, KOH examination, and fungal culture were performed in one hundred fifty clinically diagnosed cases of tinea capitis with patients' age upto 14 years over a period of 6 months. The epidemiological factors associated with the disease were also evaluated.Results: Tinea capitis was predominant in the 3–6 and 6–9 years age groups with a male preponderance. Grey patch tinea capitis was the most common variant. KOH positivity was 76%, and Trichophyton tonsurans was the most common fungal isolate. Conclusion: Tinea capitis is a very common fungal infection in our setting. Early detection and diagnosis is mandatory to prevent its spread in the community as well as the development of scarring alopecia in the affected individual

Characterisation of tracers for aging of α-pinene secondary organic aerosol using liquid chromatography/negative ion electrospray ionisation mass spectrometry

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