scholarly journals Mycobacterium tuberculosis in a closed colony of baboons (Papio ursinus)

1983 ◽  
Vol 17 (2) ◽  
pp. 125-128 ◽  
Author(s):  
P. B. Fourie ◽  
M. W. Odendaal
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Nonhuman Primate ◽  
Preventive Measures ◽  
Throat Swab ◽  
Disease Development ◽  
Papio Ursinus ◽  
X Ray ◽  
Closed Colony ◽  
Experimental Interference ◽  
Tuberculin Tests

An outbreak of tuberculosis in a nonhuman primate colony involved 11 of 91 (12·1%) baboons ( Papio ursinus). Tuberculin tests identified 80%, X-ray screening 10% and throat swab bacteriology 30% of diseased animals. Cough was a misleading indicator of tuberculosis. Stress resulting from experimental interference with animals was unrelated to disease development. Twice as many females as males were attacked. Screening and prophylactic, therapeutic and preventive measures are discussed.

X-ray crystal structure of Mycobacterium tuberculosis haloalkane dehalogenase Rv2579

2008 ◽  
Vol 1784 (2) ◽  
pp. 351-362 ◽  
Author(s):  
Pooja A. Mazumdar ◽  
Jordan C. Hulecki ◽  
Maia M. Cherney ◽  
Craig R. Garen ◽  
Michael N.G. James
Keyword(s):  
Crystal Structure ◽  
Mycobacterium Tuberculosis ◽  
Haloalkane Dehalogenase ◽  
X Ray

scholarly journals Comparative study of non-ionic contrast agents Optiray 350 and Ultravist 370 in myelography in dogs

2016 ◽  
Vol 73 (2) ◽  
pp. 243
Author(s):  
Radu Lăcătuș ◽  
Robert Cristian Purdoiu ◽  
Ardelean Filip ◽  
Ileana Matei ◽  
Maximiliean Muntean ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Contrast Agents ◽  
Preventive Measures ◽  
Atomic Weight ◽  
X Ray ◽  
Blood Biochemical ◽  
Ionic Contrast ◽  
Essential Quality ◽  
Spinal Condition

Introduction: An essential quality of non-ionic contrast agents is that of containing in their chemical composition, elements with high atomic weight, which determine an increasing absorption of the X-ray beam and this will cause intense radiopacity. The possibilities for radiological exploration with non-ionic contrast agents are very wide. Currently the radiological examination with contrast agent no longer constitutes a risky step in medical diagnosis. Aims: To highlight the importance of using the non-ionic contrast agents Optiray 350 and Ultravist 370 in dog’s myelography and to compare the changes induced in cerebrospinal fluid and blood biochemical constituents by the administration of those non-ionic contrast substances. Materials and Methods: To determine the influence of non-ionic preparations Optiray 350 and Ultravist 370 on cerebrospinal fluid and on some haematological parameters were included in the study a total of 10 dogs. Results: Myelographies with Optiray 350 and Ultravist 370 in dogs with severe spinal condition negatively influence biochemical and haematological blood status, being necessary to take preventive measures. Optiray 350 and Ultravist 370 administration cause a slight sensitization of liver with blood biochemical parameters return to normal within 24-48 hours. Conclusion: Non-ionic contrast agents Optiray 350 and Ultravist 370 offer a very good opacification of the subarachnoidian space, but because it causes liver sensitization, we recommend using them with caution and only after a prior check of liver function.

scholarly journals Symptoms, Features of Diagnosis and Preventive Measures During the “Second Wave” COVID-19 in Residents of the Kyrgyz Republic

2021 ◽  
Vol 7 (4) ◽  
pp. 164-175
Author(s):  
Sh. Sulaimanov ◽  
Zh. Esenalieva
Keyword(s):  
Large Scale ◽  
Preventive Measures ◽  
Kyrgyz Republic ◽  
Social Changes ◽  
Intellectual Work ◽  
X Ray ◽  
Coronavirus Infection ◽  
Spread Of Infection ◽  
Second Wave ◽  
Muscle Ache

The results of our study show that the respondent’s perception of large-scale social changes associated with the pandemic of the new coronavirus infection in the Kyrgyz Republic has a number of features. A sufficient level of awareness of the respondents about the symptoms of the disease, the ways of transmission of the virus, and measures to prevent the spread of infection are combined with an underestimation of the situation (17.2%). The majority (66.6%) of the respondents lived in Bishkek. The survey was held among 247 people, most of whom were women (57.3%) and young people (35.9±14.9 years). Every fourth participant in the study is a chronic tobacco smoker (24%). Less than half (47.3%) of the respondents were engaged in intellectual work. Among the respondents, the most common symptoms of COVID-19 were loss of taste or smell, fever, headache, muscle ache, cough, sore throat. Every third (28.4%) respondent was referred to an X-ray, CT scan. PCR and ELISA studies were carried out, respectively, by 22.5% and 10.9%.

scholarly journals Enzymatic β-Oxidation of the Cholesterol Side Chain in Mycobacterium Tuberculosis Bifurcates Stereospecifically at Hydration of 3-Oxo-Cholest-4,22- Dien-24-Oyl-CoA

2021 ◽  
Author(s):  
Tianao Yuan ◽  
Joshua Werman ◽  
Xingyu Yin ◽  
Meng Yang ◽  
Miguel Garcia-Diaz ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Fatty Acid ◽  
Alcohol Dehydrogenase ◽  
Side Chain ◽  
Crystallographic Structure ◽  
X Ray ◽  
Steroid Substrate ◽  
Unique Ability ◽  
Therapeutics Development ◽  
Chain Type

<p>The unique ability of <i>Mycobacterium tuberculosis </i>(Mtb) to utilize host lipids such as cholesterol for survival, persistence, and virulence has made the metabolic pathway of cholesterol an area of great interest for therapeutics development, and bioproduction of valuable sterol intermediates. Herein, we identify and characterize two genes from the <a></a><a>Cho-region of the Mtb genome</a>, <i>chsH3 </i>(Rv3538) and <i>chsB1</i> (Rv3502c). Their protein products catalyze <a></a><a>two sequential stereospecific</a>hydration and dehydrogenation steps in the b-oxidation of the cholesterol side chain. ChsH3 favors the <i>22S</i> hydration of 3-oxo-cholest-4,22-dien-24-oyl-CoA in contrast to the previously reported EchA19 (Rv3516) which catalyzes formation of the (<i>22R</i>)-hydroxy-3-oxo-cholest-4-en-24-oyl-CoA from the same enoyl-CoA substrate. ChsB1 is stereospecific and catalyzes dehydrogenation of the ChsH3 product, but not the EchA19 product. The X-ray crystallographic structure of the ChsB1 apo-protein was determined at a resolution of 2.03 Å and the holo-enzyme with bound NAD<sup>+</sup> cofactor at 2.21 Å.The homodimeric structure is representative of a classical NAD<sup>+</sup> utilizing short-chain type alcohol dehydrogenase/reductase, including a Rossmann-fold motif, but exhibits a unique substrate binding site architecture that is of greater length and width than its homologous counterparts, likely to accommodate the bulky steroid substrate. Intriguingly, Mtb utilizes MaoC-like hydratases in sterol side-chain catabolism in contrast to fatty acid b-oxidation in other species that utilize the evolutionarily distinct crotonase family of hydratases. </p>

scholarly journals Knowledge, Attitude, and Practice (KAP) of Radiographic Protection by Dental Undergraduate and Endodontic Postgraduate Students, General Practitioners, and Endodontists

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Amal A. Almohaimede ◽  
Mohammad W. Bendahmash ◽  
Feras M. Dhafr ◽  
Abdullah F. Awwad ◽  
Ebtissam M. Al-Madi
Keyword(s):  
Saudi Arabia ◽  
Radiation Protection ◽  
General Practitioners ◽  
Undergraduate Students ◽  
Preventive Measures ◽  
Dental Students ◽  
National Council ◽  
Academic Field ◽  
Postgraduate Students ◽  
X Ray

The aim of this study is to evaluate the knowledge, attitude, and perception of radiation hazard and preventive measures among dental undergraduate students, general practitioners, endodontic postgraduate students, and endodontists in Saudi Arabia. Multiple choice questions questionnaires were distributed among undergraduate and endodontic postgraduate dental students, general practitioners, and endodontists in the colleges of dentistry in Saudi Arabia, government hospitals, and private clinics. The questionnaire included sociodemographic data, assessment of the knowledge of radiation physics and biology, assessment of the practice of dental radiography, and assessment of knowledge of radiation protection. Chi-square test was used for individual and multiresponse analysis. Level of statistical significance was set at P≤0.05. Three hundred and twenty-nine responded to the questionnaire. More than half of the respondents agreed that dental X-ray is hazardous to health (60.79%), and 68.1% were familiar with ALARA (as low as reasonably achievable) principle. However, only 34% are familiar with the recommendations of the National Council on Radiation Protection (NCRP) and International Commission on Radiological Protection (ICRP). The use of lead apron and thyroid collar for patients’ protection from X-ray radiation was practiced among endodontic postgraduate students more frequently as well as those who are proactive in the academic field. Undergraduate students, endodontic postgraduate students, and endodontists in the academic field were the most aware towards radiation reduction measures. The use of the preventive measures needs to be emphasized more among general practitioners, endodontic postgraduate students, and endodontists especially in governmental hospitals and private sectors.

scholarly journals A single amino acid substitution uncouples catalysis and allostery in an essential biosynthetic enzyme in Mycobacterium tuberculosis

2020 ◽  
Vol 295 (19) ◽  
pp. 6252-6262 ◽  
Author(s):  
Wanting Jiao ◽  
Yifei Fan ◽  
Nicola J. Blackmore ◽  
Emily J. Parker
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Amino Acid ◽  
Isothermal Calorimetry ◽  
Conformational Dynamics ◽  
Chorismate Mutase ◽  
Fine Tuning ◽  
Backbone Dynamics ◽  
Single Amino Acid ◽  
Complex Dynamic ◽  
X Ray

Allostery exploits the conformational dynamics of enzymes by triggering a shift in population ensembles toward functionally distinct conformational or dynamic states. Allostery extensively regulates the activities of key enzymes within biosynthetic pathways to meet metabolic demand for their end products. Here, we have examined a critical enzyme, 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (DAH7PS), at the gateway to aromatic amino acid biosynthesis in Mycobacterium tuberculosis, which shows extremely complex dynamic allostery: three distinct aromatic amino acids jointly communicate occupancy to the active site via subtle changes in dynamics, enabling exquisite fine-tuning of delivery of these essential metabolites. Furthermore, this allosteric mechanism is co-opted by pathway branchpoint enzyme chorismate mutase upon complex formation. In this study, using statistical coupling analysis, site-directed mutagenesis, isothermal calorimetry, small-angle X-ray scattering, and X-ray crystallography analyses, we have pinpointed a critical node within the complex dynamic communication network responsible for this sophisticated allosteric machinery. Through a facile Gly to Pro substitution, we have altered backbone dynamics, completely severing the allosteric signal yet remarkably, generating a nonallosteric enzyme that retains full catalytic activity. We also identified a second residue of prime importance to the inter-enzyme communication with chorismate mutase. Our results reveal that highly complex dynamic allostery is surprisingly vulnerable and provide further insights into the intimate link between catalysis and allostery.

scholarly journals Evidence for an Elongated Dimeric Structure of Heparin-Binding Hemagglutinin from Mycobacterium tuberculosis

2008 ◽  
Vol 190 (13) ◽  
pp. 4749-4753 ◽  
Author(s):  
Carla Esposito ◽  
Maxim V. Pethoukov ◽  
Dmitri I. Svergun ◽  
Alessia Ruggiero ◽  
Carlo Pedone ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Virulence Factor ◽  
Biochemical Characterization ◽  
Coiled Coil ◽  
Heparin Binding ◽  
Truncated Form ◽  
X Ray ◽  
Dimeric Structure ◽  
X Ray Scattering

ABSTRACT Heparin-binding hemagglutinin (HBHA) is a virulence factor of tuberculosis which is responsible for extrapulmonary dissemination of this disease. A thorough biochemical characterization of HBHA has provided experimental evidence of a coiled-coil nature of HBHA. These data, together with the low-resolution structures of a full-length form and a truncated form of HBHA obtained by small-angle X-ray scattering, have unambiguously indicated that HBHA has a dimeric structure with an elongated shape.

scholarly journals X-ray structure of peptidyl-prolyl cis-trans isomerase A from Mycobacterium tuberculosis

2004 ◽  
Vol 271 (20) ◽  
pp. 4107-4113 ◽  
Author(s):  
Lena M. Henriksson ◽  
Patrik Johansson ◽  
Torsten Unge ◽  
Sherry L. Mowbray
Keyword(s):  
Mycobacterium Tuberculosis ◽  
X Ray
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