Analysis of the Identification Results of Medical Damage in 20 Urological Death Cases.

Objectives: To explore the causes of related medical damage risks and preventive measures by analyzing the identification results of medical damage in 20 urological death cases.

Methods: A retrospective analysis was conducted on 20 death cases of medical damage identification involving urology diagnosis and treatment accepted by the Judicial Appraisal Center, School of Forensic Medicine, Guizhou Medical University, and Academy of Forensic Science from 2010 to 2023.

Results: Among the 20 cases, the male-to-female ratio was 1.

Alanine synthesized by alanine dehydrogenase enables ammonium-tolerant nitrogen fixation in T27.

Most diazotrophs fix nitrogen only under nitrogen-limiting conditions, for example, in the presence of relatively low concentrations of NH (0 to 2 mM). However, T27 exhibits an unusual pattern of nitrogen regulation of nitrogen fixation, since although nitrogenase activities are high under nitrogen-limiting conditions (0 to 3 mM NH) and are repressed under conditions of nitrogen sufficiency (4 to 30 mM NH), nitrogenase activity is reestablished when very high levels of NH (30 to 300 mM) are present in the medium. To further understand this pattern of nitrogen fixation regulation, we carried out transcriptome analyses of T27 in response to increasing ammonium concentrations.

Characteristics and Risk Factors for Persistent Cough After Pulmonary Resection.

Background: Persistent cough after pulmonary resection may reduce quality of life for patients. However, there remains a lack of description of clinical characteristics and the risk factors for persistent cough after pulmonary resection. This study aimed to describe the characteristics of persistent cough after pulmonary resection and investigate independent risk factors for it.

Zinc-Responsive Regulator Zur Regulates Zinc Homeostasis, Secondary Metabolism, and Morphological Differentiation in Streptomyces avermitilis.

Zinc is an essential cofactor for many metal enzymes and transcription regulators. Zn availability has long been known to affect antibiotic production and morphological differentiation of species. However, the molecular mechanism whereby zinc regulates these processes remains unclear.

Avermectin B1a production in Streptomyces avermitilis is enhanced by engineering aveC and precursor supply genes.

Avermectins (AVEs) are economically potent anthelmintic agents produced by Streptomyces avermitilis. Among eight AVE components, B1a exhibits the highest insecticidal activity. The purpose of this study was to enhance B1a production, particularly in the high-yielding industrial strain A229, by a combination strategy involving the following steps.

Heat Shock Repressor HspR Directly Controls Avermectin Production, Morphological Development, and HO Stress Response in Streptomyces avermitilis.

The heat shock response (HSR) is a universal cellular response that promotes survival following temperature increase. In filamentous , which accounts for ∼70% of commercial antibiotic production, HSR is regulated by transcriptional repressors; in particular, the widespread MerR-family regulator HspR has been identified as a key repressor. However, functions of HspR in other biological processes are unknown.

SufR, a [4Fe-4S] Cluster-Containing Transcription Factor, Represses the Operon in Streptomyces avermitilis Iron-Sulfur Cluster Assembly.

Iron-sulfur (Fe-S) clusters are ubiquitous and versatile inorganic cofactors that are crucial for many fundamental bioprocesses in nearly all organisms. How cells maintain Fe-S cluster homeostasis is not well understood in Gram-positive bacteria. Genomic analysis showed that the Suf system, which is encoded by the operon, is the sole Fe-S cluster assembly system in the genus is the industrial producer of avermectins, which are widely used as agricultural pesticides and antiparasitic agents.

The ROK-family regulator Rok7B7 directly controls carbon catabolite repression, antibiotic biosynthesis, and morphological development in Streptomyces avermitilis.

Carbon catabolite repression (CCR) is a common phenomenon in bacteria that modulates expression of genes involved in uptake of alternative carbon sources. In the filamentous streptomycetes, which produce half of all known antibiotics, the precise mechanism of CCR is yet unknown. We report here that the ROK-family regulator Rok7B7 pleiotropically controls xylose and glucose uptake, CCR, development, as well as production of the macrolide antibiotics avermectin and oligomycin A in Streptomyces avermitilis.

AccR, a TetR Family Transcriptional Repressor, Coordinates Short-Chain Acyl Coenzyme A Homeostasis in .

Malonyl coenzyme A (malonyl-CoA) and methylmalonyl-CoA are the most common extender units for the biosynthesis of fatty acids and polyketides in , an industrially important producer of polyketides. Carboxylation of acetyl- and propionyl-CoAs is an essential source of malonyl- and methylmalonyl-CoAs; therefore, acyl-CoA carboxylases (ACCases) play key roles in primary and secondary metabolism. The regulation of the expression of ACCases in spp.

BldD, a master developmental repressor, activates antibiotic production in two Streptomyces species.

BldD generally functions as a repressor controlling morphological development of Streptomyces. In this work, evidences that BldD also activates antibiotic production are provided. In Streptomyces roseosporus (which produces daptomycin widely used for treatment of human infections), deletion of bldD notably reduced daptomycin production, but enhanced sporulation.

A new technology for reducing anastomotic fistula in the neck after esophageal cancer surgery.

Background: To explore the risk factors and prevention methods of cervical mechanical anastomotic fistula and stenosis after the radical resection of esophageal cancer.

Methods: From March 2018 to November 2018, 128 patients undergoing mechanical anastomosis of esophageal cancer were selected from the Department of Thoracic Surgery of The First Affiliated Hospital of Zhengzhou University. All the enrolled patients were operated on using the Mckeown method, and a retrospective study was conducted.

AveI, an AtrA homolog of Streptomyces avermitilis, controls avermectin and oligomycin production, melanogenesis, and morphological differentiation.

Streptomyces avermitilis is well known as the producer of anthelmintic agent avermectins, which are widely used in agriculture, veterinary medicine, and human medicine. aveI encodes a TetR-family regulator, which is the homolog of AtrA. It was reported that deletion of aveI caused enhanced avermectin production.

Epsilon-FeO is a novel intermediate for magnetite biosynthesis in magnetotactic bacteria.

Background: Natural biological magnetite nanoparticles are widely distributed from microorganisms to humans. It is found to be very important in organisms, especially in navigation. Moreover, purified magnetite nanoparticles also have potential applications in bioengineering and biomedicine.

Novel Protein Mg2046 Regulates Magnetosome Synthesis in MSR-1 by Modulating a Proper Redox Status.

Magnetotactic bacteria (MTB) are a large, polyphyletic group of aquatic microorganisms capable of absorbing large amounts of iron and synthesizing intercellular nano-scaled nanoparticles termed magnetosomes. In our previous transcriptomic studies, we discovered that a novel gene (, termed as ) in strain MSR-1 was significantly up-regulated during the period of magnetosome synthesis. In the present study, we constructed a MSR-1 mutant strain with deletion of (termed ) in order to evaluate the role of this gene in cell physiological status and magnetosome formation process.

Combined Assembly and Targeted Integration of Multigene for Nitrogenase Biosynthetic Pathway in .

Biological nitrogen fixation, a process unique to diazotrophic prokaryote, is catalyzed by the nitrogenase complex. There has been a long-standing interest in reconstituting a nitrogenase biosynthetic pathway in a eukaryotic host with the final aim of developing N-fixing cereal crops. In this study, we report that a nitrogenase biosynthetic pathway (∼38 kb containing 15 genes) was assembled in two individual one-step methods via assembly and integrated at δ and sites in chromosome.

Different construction strategies affected on the physiology of Pichia pastoris strains highly expressed lipase by transcriptional analysis of key genes.

We demonstrated previously that expression of Rhizomucor miehei lipase (RML) in Pichia pastoris could be significantly increased by addition of gene propeptide, optimized signal peptide codons and manipulation of gene dosage. In this study, effects of various strategies on the protein synthesis and secretion pathways were analyzed. Using nine strains previously constructed, we evaluated cell culture properties, enzymatic activities, and analyzed transcriptional levels of nine genes involved in protein synthesis and secretion pathways by qPCR.

α-Lys Participates in Insertion of FeMoco to MoFe Protein and Maintains Nitrogenase Activity in M5al.

Our previous investigation of substrates reduction catalyzed by nitrogenase suggested that α-Ile of MoFe protein possibly functions as an electron transfer gate to Mo site of active center-"FeMoco". Amino acid residue α-Lys connects directly to α-Ile, and they are located in the same α-helix (α423-431). In the present study, function of α-Lys was investigated by replacing it with Arg (alkaline, like Lys), Gln (neutral), Glu (acidic), and Ala (neutral) through site-directed mutagenesis and homologous recombination.

Work Patterns of MamXY Proteins during Magnetosome Formation in MSR-1.

The bacterium MSR-1 forms nanosized membrane-enclosed organelles termed magnetosomes. The operon, part of the magnetosome island (MAI), includes the , , , and -like genes, which initiate gene transcription via the same promoter. We used a combination of molecular biological techniques (targeting of cross-linking reagents) and high-resolution mass spectrometry to investigate the coordinated activity of the four MamXY proteins in magnetite biomineralization.

Positive and negative regulation of transferred nif genes mediated by indigenous GlnR in Gram-positive Paenibacillus polymyxa.

Ammonia is a major signal that regulates nitrogen fixation in most diazotrophs. Regulation of nitrogen fixation by ammonia in the Gram-negative diazotrophs is well-characterized. In these bacteria, this regulation occurs mainly at the level of nif (nitrogen fixation) gene transcription, which requires a nif-specific activator, NifA.

IdeR, a DtxR Family Iron Response Regulator, Controls Iron Homeostasis, Morphological Differentiation, Secondary Metabolism, and the Oxidative Stress Response in Streptomyces avermitilis.

Iron, an essential element for microorganisms, functions as a vital cofactor in a wide variety of key metabolic processes. On the other hand, excess iron may have toxic effects on bacteria by catalyzing the formation of reactive oxygen species through the Fenton reaction. The prevention of iron toxicity requires the precise control of intracellular iron levels in bacteria.

SAV4189, a MarR-Family Regulator in , Activates Avermectin Biosynthesis.

The bacterial species is an important industrial producer of avermectins, which are widely utilized as effective anthelmintic and insecticidal drugs. We used gene deletion, complementation, and overexpression experiments to identify SAV4189, a MarR-family transcriptional regulator (MFR) in this species, as an activator of avermectin biosynthesis. SAV4189 indirectly stimulated avermectin production by altering expression of cluster-situated activator gene , and directly repressed the transcription of its own gene () and adjacent cotranscribed gene (which encodes an unknown transmembrane efflux protein).

Organic Peroxide-Sensing Repressor OhrR Regulates Organic Hydroperoxide Stress Resistance and Avermectin Production in .

The bacterium is an industrial-scale producer of avermectins, which are important anthelmintic agents widely used in agriculture, veterinary medicine, and human medicine. During the avermectin fermentation process, is exposed to organic peroxides generated by aerobic respiration. We investigated the role of MarR-family transcriptional regulator OhrR in oxidative stress response and avermectin production in .

Efficient heterologous expression of an alkaline lipase and its application in hydrolytic production of free astaxanthin.

Background: Astaxanthin, a naturally occurring carotenoid pigment molecule, displays strong antioxidant, anti-cancer, and immunity-enhancing properties, and is often utilized in food, biomedical, cosmetic, and other industries. Free astaxanthin has better solubility than astaxanthin esters (Ast-E), and is a useful auxiliary ingredient in health foods and medicines. Our goal was to establish an improved enzymatic method for preparation of free astaxanthin from natural sources (e.