Interactions with sulfur acceptors modulate the reactivity of cysteine desulfurases and define their physiological functions.

Sulfur-containing biomolecules such as [FeS] clusters, thiamin, biotin, molybdenum cofactor, and sulfur-containing tRNA nucleosides are essential for various biochemical reactions. The amino acid l-cysteine serves as the major sulfur source for the biosynthetic pathways of these sulfur-containing cofactors in prokaryotic and eukaryotic systems. The first reaction in the sulfur mobilization involves a class of pyridoxal-5'-phosphate (PLP) dependent enzymes catalyzing a Cys:sulfur acceptor sulfurtransferase reaction.

HIV in pregnant woman and children: Mother-to-child transmission of HIV in the Brazilian land border from 2010 to 2021.

Objective: The aim of the present study was to analyze the profile and trends of HIV mother-to-child transmission (MTCT) in the Brazilian land border strip (LBS).

Methods: This was a quantitative, ecological, and cross-sectional study using secondary data available in the information systems of the Brazilian Ministry of Health. All cases reported in the Notifiable Diseases Information System between 2010 and 2021 were studied.

Alternate routes to mnmsU synthesis in Gram-positive bacteria.

The wobble bases of tRNAs that decode split codons are often heavily modified. In bacteria, tRNA contains a variety of xnmsU derivatives. The synthesis pathway for these modifications is complex and fully elucidated only in a handful of organisms, including the Gram-negative K12 model.

Alternate routes to mnm s U synthesis in Gram-positive bacteria.

Unlabelled: The wobble bases of tRNAs that decode split codons are often heavily modified. In Bacteria tRNA contain a variety of xnm s U derivatives. The synthesis pathway for these modifications is complex and fully elucidated only in a handful of organisms, including the Gram-negative K12 model.

Sulfinamide Formation from the Reaction of Bacillithiol and Nitroxyl.

Bacillithiol (BSH) replaces glutathione (GSH) as the most prominent low-molecular-weight thiol in many low G + C gram-positive bacteria. BSH plays roles in metal binding, protein/enzyme regulation, detoxification, redox buffering, and bacterial virulence. Given the small amounts of BSH isolated from natural sources and relatively lengthy chemical syntheses, the reactions of BSH with pertinent reactive oxygen, nitrogen, and sulfur species remain largely unexplored.

Perspectives and challenges for mother-to-child transmission of HIV, hepatitis B, and syphilis in Brazil.

Background: Eliminating mother-to-child transmission (MTCT) of HIV, hepatitis B, and syphilis is a challenge in Brazil. Many policies have been implemented since 1986, but important gaps remain. This study aimed to describe the trends of MTCT in Brazil and evaluate the gaps and perspectives in this scenario.

The effect of volunteer-led activities on the quality of life of volunteers, residents, and employees of a long-term care institution: a cohort study.

Background: The COVID-19 pandemic primarily impacted long-term care facilities by restricting visiting and circulation of visitors, affecting the quality of life (QoL) of older adults living in these institutions. Volunteer activities, essential for older adults' daily life, were also interrupted and potentially negatively impacted the QoL of older adults, volunteers themselves, and also employees in these institutions. In this context, this study aims to evaluate the impact of the return of volunteer-led activities in a long-term care institution on the QoL of older adult residents, employees, and volunteers.

Overview of physiological, biochemical, and regulatory aspects of nitrogen fixation in .

Understanding how Nature accomplishes the reduction of inert nitrogen gas to form metabolically tractable ammonia at ambient temperature and pressure has challenged scientists for more than a century. Such an understanding is a key aspect toward accomplishing the transfer of the genetic determinants of biological nitrogen fixation to crop plants as well as for the development of improved synthetic catalysts based on the biological mechanism. Over the past 30 years, the free-living nitrogen-fixing bacterium emerged as a preferred model organism for mechanistic, structural, genetic, and physiological studies aimed at understanding biological nitrogen fixation.

Gestational and congenital syphilis across the international border in Brazil.

Background: Brazil lacks data from syphilis in its border areas. We aimed to describe the spatial and temporal distribution of acquired syphilis (AS), in pregnancy (SP) and congenital syphilis (CS) in Brazilian municipalities in the arches border contexts.

Methods: An ecological, cross-sectional study was conducted from 2010 to 2020.

Sulfur Availability Impacts Accumulation of the 2-Thiouridine tRNA Modification in Bacillus subtilis.

Posttranscriptional modifications to tRNA are critical elements for the folding and functionality of these adaptor molecules. Sulfur modifications in tRNA are installed by specialized enzymes that act on cognate tRNA substrates at specific locations. Most studied organisms contain a general cysteine desulfurase to mobilize sulfur for the synthesis of S-tRNA and other thio-cofactors.

Methods to Investigate the Kinetic Profile of Cysteine Desulfurases.

Biological iron-sulfur (Fe-S) clusters are essential protein prosthetic groups that promote a range of biochemical reactions. In vivo, these clusters are synthesized by specialized protein machineries involved in sulfur mobilization, cluster assembly, and cluster transfer to their target proteins. Cysteine desulfurases initiate the first step of sulfur activation and mobilization in cluster biosynthetic pathways.

tRNA Modifications as a Readout of S and Fe-S Metabolism.

Iron-Sulfur (Fe-S) clusters function as core prosthetic groups known to modulate the activity of metalloenzymes, act as trafficking vehicles for biological iron and sulfur, and participate in several intersecting metabolic pathways. The formation of these clusters is initiated by a class of enzymes called cysteine desulfurases, whose primary function is to shuttle sulfur from the amino acid L-cysteine to a variety of sulfur transfer proteins involved in Fe-S cluster synthesis as well as in the synthesis of other thiocofactors. Thus, sulfur and Fe-S cluster metabolism are connected through shared enzyme intermediates, and defects in their associated pathways cause a myriad of pleiotropic phenotypes, which are difficult to dissect.

Extracurricular Functions of tRNA Modifications in Microorganisms.

Transfer RNAs (tRNAs) are essential adaptors that mediate translation of the genetic code. These molecules undergo a variety of post-transcriptional modifications, which expand their chemical reactivity while influencing their structure, stability, and functionality. Chemical modifications to tRNA ensure translational competency and promote cellular viability.

Distribution of Nitrogen-Fixation Genes in Prokaryotes Containing Alternative Nitrogenases.

Biological nitrogen fixation is an inherent trait exclusive to a select number of prokaryotes. Although molybdenum nitrogenase is the dominant catalyst for dinitrogen reduction, some diazotrophs also contain one or two additional types of nitrogenase that use alternative metal content as the active-site cofactor. The occurrence of alternative nitrogenases has not been well studied due to the discriminatory expression of the molybdenum nitrogenase and lack of comprehensive genomic data.

The Thioredoxin System Reduces Protein Persulfide Intermediates Formed during the Synthesis of Thio-Cofactors in Bacillus subtilis.

The biosynthesis of Fe-S clusters and other thio-cofactors requires the participation of redox agents. A shared feature in these pathways is the formation of transient protein persulfides, which are susceptible to reduction by artificial reducing agents commonly used in reactions in vitro. These agents modulate the reactivity and catalytic efficiency of biosynthetic reactions and, in some cases, skew the enzymes' kinetic behavior, bypassing sulfur acceptors known to be critical for the functionality of these pathways in vivo.

Metallocluster transactions: dynamic protein interactions guide the biosynthesis of Fe-S clusters in bacteria.

Iron-sulfur (Fe-S) clusters are ubiquitous cofactors present in all domains of life. The chemistries catalyzed by these inorganic cofactors are diverse and their associated enzymes are involved in many cellular processes. Despite the wide range of structures reported for Fe-S clusters inserted into proteins, the biological synthesis of all Fe-S clusters starts with the assembly of simple units of 2Fe-2S and 4Fe-4S clusters.

Genomic Manipulations of the Diazotroph Azotobacter vinelandii.

The biological reduction of nitrogen gas to ammonia is limited to a select group of nitrogen-fixing prokaryotes. While nitrogenase is the catalyst of nitrogen fixation in these biological systems, a consortium of additional gene products is required for the synthesis, activation, and catalytic competency of this oxygen-sensitive metalloenzyme. Thus, the biochemical complexity of this process often requires functional studies and isolation of gene products from the native nitrogen-fixing organisms.

Thiosemicarbazone of lapachol acts on cell membrane in Paracoccidioides brasiliensis.

Paracoccidioidomycosis (PCM) is the most prevalent systemic mycosis in Latin American countries. Amphotericin B, sulfonamides, and azoles may be used in the treatment of PCM. However, the high toxicity, prolonged course of treatment, and significant frequency of disease relapse compromise their use.

Treatment with Atorvastatin Provides Additional Benefits to Imipenem in a Model of Gram-Negative Pneumonia Induced by Klebsiella pneumoniae in Mice.

The clinical pathogen is a relevant cause of nosocomial infections, and resistance to current treatment with carbapenem antibiotics is becoming a significant problem. Statins are inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) used for controlling plasma cholesterol levels. There is clinical evidence showing other effects of statins, including decrease of lung inflammation.

Influenza A Virus as a Predisposing Factor for Cryptococcosis.

Influenza A virus (IAV) infects millions of people annually and predisposes to secondary bacterial infections. Inhalation of fungi within the complex causes pulmonary disease with secondary meningo-encephalitis. Underlying pulmonary disease is a strong risk factor for development of cryptococcosis though the effect of concurrent infection with IAV has not been studied.

B. subtilis as a Model for Studying the Assembly of Fe-S Clusters in Gram-Positive Bacteria.

Complexes of iron and sulfur (Fe-S clusters) are widely distributed in nature and participate in essential biochemical reactions. The biological formation of Fe-S clusters involves dedicated pathways responsible for the mobilization of sulfur, the assembly of Fe-S clusters, and the transfer of these clusters to target proteins. Genomic analysis of Bacillus subtilis and other Gram-positive bacteria indicated the presence of only one Fe-S cluster biosynthesis pathway, which is distinct in number of components and organization from previously studied systems.

Dysregulation of H/ACA ribonucleoprotein components in chronic lymphocytic leukemia.

Telomeres are protective repeats of TTAGGG sequences located at the end of human chromosomes. They are essential to maintain chromosomal integrity and genome stability. Telomerase is a ribonucleoprotein complex containing an internal RNA template (hTR) and a catalytic subunit (hTERT).

Effects of supervised exercise and dietary nitrate in older adults with controlled hypertension and/or heart failure with preserved ejection fraction.

Aerobic exercise training is an effective therapy to improve peak aerobic power (peak VO) in individuals with hypertension (HTN, AHA/ACC class A) and heart failure patients with preserved ejection fraction (HFpEF). High nitrate containing beetroot juice (BRJ) also improves sub-maximal endurance and decreases blood pressure in both HTN and HFpEF. We hypothesized that combining an aerobic exercise and dietary nitrate intervention would result in additive or even synergistic positive effects on exercise tolerance and blood pressure in HTN or HFpEF.

Metabolically healthy obese women have longer telomere length than obese women with metabolic syndrome.

Introduction: Obesity is the principal component in the Metabolic Syndrome (MetS) that determines the progression of metabolic complications. Metabolically healthy obese (MHO) individuals seem to be protected against those complications. Telomere length (TL) as a novel marker of cellular aging had a complex relationship to the MetS.

Diverse Mechanisms of Sulfur Decoration in Bacterial tRNA and Their Cellular Functions.

Sulfur-containing transfer ribonucleic acids (tRNAs) are ubiquitous biomolecules found in all organisms that possess a variety of functions. For decades, their roles in processes such as translation, structural stability, and cellular protection have been elucidated and appreciated. These thionucleosides are found in all types of bacteria; however, their biosynthetic pathways are distinct among different groups of bacteria.