Functional Characterization and Molecular Basis of a Multi-Site Halogenase in Naphthacemycin Biosynthesis.

Halogenases are spurring a growing interest in the fields of biosynthesis and biocatalysis. Although various halogenases have been identified in numerous natural product biosynthetic pathways, the mechanisms for multiple halogenations and site-selectivity remain largely unclear. In this study, we biochemically characterized FasV, a flavin-dependent halogenase (FDH) that catalyzes five successive chlorinations in the biosynthesis of the naphthacene-containing aromatic polyketide naphthacemycin.

Efficacy of Selective Vidian Neurectomy for Allergic Rhinitis Combined with Chronic Rhinosinusitis.

Objective: The aim of this study was to investigate the efficacy of endoscopic selective vidian neurectomy in the treatment of severe persistent allergic rhinitis (AR) combined with chronic rhinosinusitis (CRS) with nasal polyps (ARwCRSwNP).

Methods: One hundred thirty patients with moderate to severe persistent ARwCRSwNP were enrolled at Xuanwu Hospital, Capital Medical University, from September 2015 to September 2017. Patients were divided into 2 groups.

A Flavin-Dependent Monooxygenase Mediates Divergent Oxidation of Rifamycin.

Rifamycins have been clinically utilized against mycobacterial infections for more than 50 years; however, their biosynthesis has not been fully elucidated. Here, on the basis of gene deletions, enzyme assays, isotope labeling, and site-directed mutations, we found that a flavin-dependent monooxygenase encoded by a rifamycin biosynthetic gene cluster, Rif-Orf17, not only converted the naphthoquinone chromophore of rifamycin S into benzo-γ-pyrone but also linearized rifamycin SV through phenolic hydroxylation. Both oxidation routes lead to inactivation of rifamycins.

Characterization of the Rifamycin-Degrading Monooxygenase From Rifamycin Producers Implicating Its Involvement in Saliniketal Biosynthesis.

Rifamycin derivatives, such as rifampicin, have potent antibiotic activity and have long been used in the clinic as mainstay components for the treatment of tuberculosis, leprosy, and AIDS-associated mycobacterial infections. However, the extensive usage of these antibiotics has resulted in the rapid development of bacterial resistance. The resistance mechanisms mainly include mutations of the rifamycin target RNA polymerase of bacteria and enzymatic modifications of rifamycin antibiotics.

The characterization and comparison of exopolysaccharides from two benthic diatoms with different biofilm formation abilities.

Exopolysaccharide (EPS) of two benthic diatoms, Amphora sp. and Stauroneis sp., with different biofilm formation abilities were investigated.

Analysis of dental injuries with clinical implications: A forensic case report.

Dental injuries, especially of the incisors, caused by punches in violent criminal attacks could be seen in daily forensic casework involving the identification of injuries to a living body. Sometimes, when there is neither circumstantial evidence nor information about the surrounding circumstances, it is difficult to discern the cause of these injuries and the manner in which they were inflicted. As an example of clinical forensic medicine, we present the case of a 58-year-old woman whose teeth were injured when fighting with her son-in-law over household affairs with no witnesses present.

The Intoxication Effects of Methanol and Formic Acid on Rat Retina Function.

Unlabelled: Objective. To explore the potential effects of methanol and its metabolite, formic acid, on rat retina function. Methods.

[Forensic Application of Microperimetry and Visual Evoked Potential in Macular Disease].

Objectiv: e To find the correlation between real best corrected visual acuity (BCVA) and testing results of microperimetry and visual evoked potential (VEP) and to explore a new method in recording BCVA in macular disease.

Methods: Sixty-two patients with macular disease (macular disease group, 62 eyes) and eighteen healthy volunteers (control group, 36 eyes) had BCVA, microperimetry and VEP recorded.

Results: (1) By microperimetry, the values of retinal mean sensitivity and fixation percentage in macular disease group were lower than that in control group.

[Correlation between contrast vision and sweep visual evoked potential acuity].

Objective: To compare the correlation between contrast vision (LV) and sweep visual evoked potential acuity (SVEP-A) among people with emmetropia, mild myopia, and moderate myopia.

Methods: The CV and SVEP-A were tested individually in 96 eyes from healthy young volunteers, including 37 eyes of emmetropia, 27 eyes of mild myopia, and 32 eyes of moderate myopia. The statistic analysis was done by ANOVA analysis and rank sum test.

[Expression and mechanism of alphaB-crystallin in retina and extraocular tissues and organs].

alphaB-crystallin is the structural protein of vertebrate lens, which is widely expressed in non-lens tissue. As one of the heat shock protein family members, alphaB-crystallin possesses biological properties of molecular chaperones and anti-apoptotic effects. Multi-factor injuries, such as retinopathy, inflammation and nervous system diseases, have a closely relationship with alphaB-crystallin.

[Changes of oscillatory potentials of electroretinogram after methanol intoxication in rats].

Objective: To study the characters of oscillatory potentials (OPs) of electroretinogram (ERG) after methanol intoxication in rats.

Method: The SD rat models of methanol intoxication were established and divided into control group, 3-day intoxication group, 7-day intoxication group. The changes of OPs of ERG were recorded in a dark room.

[Multifocal visual electrophysiology in visual function evaluation].

Multifocal visual electrophysiology, consisting of multifocal electroretinography (mfERG) and multifocal visual evoked potential (mfVEP), can objectively evaluate retina function and retina-cortical conduction pathway status by stimulating many local retinal regions and obtaining each local response simultaneously. Having many advantages such as short testing time and high sensitivity, it has been widely used in clinical ophthalmology, especially in the diagnosis of retinal disease and glaucoma. It is a new objective technique in clinical forensic medicine involving visual function evaluation of ocular trauma in particular.

[Correlativity between projected visual chart vision and contrast vision].

Objective: To study the correlativity between the projected visual chart vision ("projector vision" in this paper) and the measured values of contrast vision, and to explore the application of contrast vision in identifying visual impairment after eye injury in the clinical forensic medicine.

Methods: One hundred and twenty nine eyes of seventy-nine young volunteers were collected for examination both of projector vision and contrast vision. In the examination of contrast vision, the contrast of optotypes were set to 100%, 25% and 10%, respectively.

[Application of contrast vision in identifying the malingering decreased vision].

Objective: To study the application value of contrast vision in identifying the malingering decreased vision in the practice of clinical forensic medicine.

Methods: Thirty-one young and middle aged volunteers were selected and divided randomly into group 1 (16 persons with 32 eyes) and group 2 (15 persons with 30 eyes). The optotype contrast was 100%, 25%, 10% and 5%, respectively.