Safety and Effectiveness of Bone Allografts for Mastoid Obliteration After Mastoidectomy: A Pilot Study.

Background And Objectives: Various materials are used to perform post-mastoidectomy mastoid obliteration (MO) to reduce the risk of recurrent infections, stasis of secretions, or caloric dizziness. Autologous materials used as fillers for MO tend to be insufficient owing to shrinkage over time or inadequate volume of these substances. Synthetic materials are unsatisfactory for MO because of the risk of rejection and extrusion.

A unique dual acyltransferase system shared in the polyketide chain initiation of kidamycinone and rubiflavinone biosynthesis.

The pluramycin family of natural products has diverse substituents at the C2 position, which are closely related to their biological activity. Therefore, it is important to understand the biosynthesis of C2 substituents. In this study, we describe the biosynthesis of C2 moieties in sp.

Bone destruction in chronic otitis media is not mediated by the RANKL pathway or estrogen receptor-alpha.

Background: Chronic otitis media with or without cholesteatoma progresses with various degrees of bone resorption and remodeling. Estrogen mediates osteoprotective effects through the receptor activator of NF-κB ligand (RANKL) pathway, which is mainly mediated by estrogen receptor-alpha (ER-α).

Objectives: The present study investigated the expression patterns of receptor activator of NF-κB (RANK), osteoprotegerin (OPG), RANKL, and ER-α in pathological tissue from patients with chronic otitis media to determine the roles of those factors in osteolytic mechanisms underlying the pathogenesis of chronic otitis media.

Rubiflavin G, photorubiflavin G, and photorubiflavin E: Novel pluramycin derivatives from Streptomyces sp. W2061 and their anticancer activity against breast cancer cells.

The pluramycin family of antibiotics comprises angucycline compounds derived from actinomycetes that possess anticancer and antibacterial properties. Pluramycins are structurally characterized by two aminoglycosides linked by a carbon-carbon bond next to the γ-pyrone angucycline backbone. Kidamycins (3, 4) and rubiflavins (6-9) were screened through liquid chromatography-mass spectrometry analysis of the crude extracts of Streptomyces sp.

Hygrolansamycins A-D, -Heterocyclic Macrolides from sp. KCB17JA11.

Six ansamycin derivatives were isolated from the culture broth of sp. KCB17JA11, including four new hygrolansamycins A-D (1-4) and known congeners divergolide O (5) and hygrocin C (6). Compounds 1-5 featured an unusual six-membered -heterocyclic moiety.

Ulleungdolin, a Polyketide-Peptide Hybrid Bearing a 2,4-Di--methyl-β-d-antiarose from sp. 13F051 Co-cultured with 15S071.

A new secondary metabolite, ulleungdolin (), was isolated from the co-culture of an actinomycete, sp. 13F051, and a fungus, 15S071. Based on the NMR, UV, and MS data, it was deduced that the planar structure of comprised an isoindolinone (IsoID) with an octanoic acid, a tripeptide, and a sugar.

Elucidation of the di-c-glycosylation steps during biosynthesis of the antitumor antibiotic, kidamycin.

Kidamycins belong to the pluramycin family of antitumor antibiotics that contain di-C-glycosylated angucycline. Owing to its interesting biological activity, several synthetic derivatives of kidamycins are currently being developed. However, the synthesis of these complex structural compounds with unusual C-glycosylated residues is difficult.

Jejucarbazoles A-C, carbazole glycosides with indoleamine 2,3-dioxygenase 1 inhibitory activity from sp. KCB15JA151.

A bioassay-guided investigation led to the isolation of three new carbazole glycosides, jejucarbazoles A-C (1-3), from sp. KCB15JA151. Their planar structures were elucidated by detailed NMR and MS spectroscopic analysis with a literature study.

Leukotriene B4 Is a Major Determinant of Leukocyte Recruitment During Otitis Media.

Background: Pathogens of otitis media (OM) induce inflammatory responses in the middle ear (ME), characterized by mucosal hyperplasia, leukocyte infiltration, and inflammatory mediators, including arachidonic acid metabolites. We studied the role of the eicosanoid leukotriene B4 (LTB4) in OM.

Methods: Expression of LTB4-related genes was evaluated by gene array and single-cell RNA-Seq in MEs infected with nontypeable (NTHi).

Construction of an Artificial Biosynthetic Pathway for Zingerone Production in Using Benzalacetone Synthase from .

Zingerone (vanillylacetone; 4-hydroxy-3-methoxyphenylethyl methyl ketone) is a key component responsible for the pungency of ginger (). In this study, it was confirmed that a type III polyketide synthase (PKS) gene () from exhibits feruloyl-CoA-preferred benzalacetone synthase (BAS) activity. Based on these results, we constructed an artificial biosynthetic pathway for zingerone production from supplemented ferulic acid with 4-coumarate CoA ligase (4CL), PmPKS, and benzalacetone reductase (BAR).

Construction of an Artificial Biosynthetic Pathway for the Styrylpyrone Compound 11-Methoxy-Bisnoryangonin Produced in Engineered .

A cDNA clone (named ), which shows high homology to the known chalcone synthase (CHS)-like type III PKS, was obtained from the leaves of . The PnPKS protein with ferulic acid catalyzed lactonization instead of chalcone or stilbene formation. The new product was characterized as a styrylpyrone, 11-methoxy-bisnoryangonin, which is the lactonization compound of a linear triketide formed as the reaction product of PnPKS protein with ferulic acid.

Association between epidermal growth factor (EGF) and EGF receptor gene polymorphisms and end-stage renal disease and acute renal allograft rejection in a Korean population.

Epidermal growth factor (EGF) has been found to be associated with the development and repair mechanisms of several renal diseases. In this study, we hypothesized that single nucleotide polymorphisms (SNPs) in EGF or its receptor genes might have an association with end-stage renal disease (ESRD) or acute renal allograft rejection (AR) in a Korean population. Three-hundred and forty seven recipients of the first renal transplants for ESRD, including 63 AR patients along with 289 healthy adults were included in the study.

Isolation of new streptimidone derivatives, glutarimide antibiotics from Streptomyces sp. W3002 using LC-MS-guided screening.

A LC-MS-guided screening led to the isolation of two new streptimidone derivatives (2 and 3) containing a glutarimide ring and two glutarimide ring-opened compounds (4 and 5) along with a known glutarimide-containing polyketide, streptimidone (1) from Streptomyces sp. W3002 strain. Their structures were elucidated by MS and NMR spectroscopic analyses and by comparison with data from the literature.

Causes and prevention of revision surgery for preauricular sinus: A histopathological analysis.

Objective: Recurrence rates following preauricular sinus (PAS) surgery vary. Few studies have investigated recurrence after primary PAS surgery in histopathological terms. We performed a histopathological analysis of the causes of revision surgery for PAS, with a view to reducing the recurrence rate after primary surgery.

Catenulisporolides, Glycosylated Triene Macrolides from the Chemically Underexploited Actinomycete Catenulispora Species.

New glycosylated 26-membered triene macrolides catenulisporolides, the first polyketide metabolites from Catenulispora species, were obtained by targeting slow-forming colonies on selection agar plates and applying long-term cultivation. Their structures, including the full stereochemistry, were defined by comprehensive spectroscopic and chemical methods and confirmed by bioinformatics analysis. Analysis of the genome sequence revealed the responsible biosynthetic gene cluster spanning ∼160 kbp, and feeding experiments with isotope-labeled precursors showed that isovaleric acid acts as a rare starter unit.

Optimization of Artificial Curcumin Biosynthesis in E. coli by Randomized 5'-UTR Sequences To Control the Multienzyme Pathway.

One of the optimization strategies of an artificial biosynthetic metabolic flux with a multienzyme pathway is when the enzyme concentrations are present at the appropriate ratios rather than at their maximum expression. Thus, many recent research efforts have focused on the development of tools that fine-tune the enzyme expression, and these research efforts have facilitated the search for the optimum balance between pathway expression and cell viability. However, the rational approach has some limitations in finding the most optimized expression ratio in in vivo systems.

Production of Bioactive 3'-Hydroxystilbene Compounds Using the Flavin-Dependent Monooxygenase Sam5.

The flavin-dependent monooxygenase Sam5 was previously reported to be a bifunctional hydroxylase with a coumarte 3-hydroxylase and a resveratrol 3'-hydroxylase activity. In this article, we showed the Sam5 enzyme has 3'-hydroxylation activities for methylated resveratrol (pinostilbene and pterostilbene), hydroxylated resveratrol (oxyresveratrol) and glycosylated resveratrol (piceid) as substrates. However, the use of piceid, a glycone type stilbene, as a substrate for bioconversion experiments with the Sam5 enzyme expressed in, does not convert to the hydroxylated compound astringin, but it has converted in vitro enzyme reactions.

Novel symptom questionnaire for the differential diagnosis of detrusor underactivity and bladder outlet obstruction in men.

Objective: To develop a questionnaire for the differential diagnosis of detrusor underactivity (DUA) and bladder outlet obstruction (BOO) without performing invasive pressure flow studies.

Study Design And Methods: Symptoms of men with DUA were analyzed and compared with those of men with BOO using eight questions from the developing questionnaire. Patients with DUA have a bladder contractility index (PdetQmax+5xQmax) less than 100, whereas those with BOO have a BOO index (PdetQmax-2xQmax) greater than 40 in urodynamic studies (UDS).

Necessity of admission to improve the hearing-recovery rate in idiopathic sudden sensorineural hearing loss.

Objectives: The purpose of this study was to determine the prognostic potential of admission of a patient for idiopathic sudden sensorineural hearing loss (ISSNHL).

Study Design: Retrospective clinical study.

Methods: We conducted a retrospective study of 301 patients with ISSNHL.

Genomics-Driven Discovery of Chlorinated Cyclic Hexapeptides Ulleungmycins A and B from a Streptomyces Species.

Analysis of the genome sequence of Streptomyces sp. KCB13F003 showed the presence of a cryptic gene cluster encoding flavin-dependent halogenase and nonribosomal peptide synthetase. Pleiotropic approaches using multiple culture media followed by LC-MS-guided isolation and spectroscopic analysis enabled the identification of two new chlorinated cyclic hexapeptides, ulleungmycins A and B (1 and 2).

Production of Bacterial Quorum Sensing Antagonists, Caffeoyl- and Feruloyl-HSL, by an Artificial Biosynthetic Pathway.

A new series comprising phenylacetyl-homoserine lactones (HSLs), caffeoyl-HSL and feruloyl-HSL, was biologically synthesized using an artificial de novo biosynthetic pathway. We developed an Escherichia coli system containing artificial biosynthetic pathways that yield phenylacetyl-HSLs from simple carbon sources. These artificial biosynthetic pathways contained the LuxI-type synthase gene () in addition to caffeoyl-CoA and feruloyl-CoA biosynthetic genes, respectively.

Impact of nasal conditions on chronic otitis media: a cross-sectional study in Koreans.

Objectives: We evaluated the relationship between pathological nasal conditions and pathological middle ear conditions on a large-scale epidemiological basis, conducted as a cross-sectional study at the population level using Korean National Health and Nutrition Examination Survey (KNHANES) data.

Study Design: A cross-sectional study.

Methods: In a retrospective cohort study, we analyzed data from the KNHANES (2008-2012), which used a stratified, multi-stage, probability-cluster sampling method in a rolling sampling survey of South Korean citizens.

Methotrexate Induces Apoptosis in Organ-Cultured Nasal Polyps Via the Fas Pathway.

Objective: Methotrexate (MTX) is very effective when used to treat chronic inflammatory diseases, and also induces apoptosis in nasal polyps (NPs). Increasing evidence suggests that Fas-Fas ligand (FasL) interactions activate multiple pathways involved in the regulation of immune and inflammatory cell functions. The aim of the present study was to identify pathways activated by Fas signaling when NPs were treated with MTX.

De novo biosynthesis of pterostilbene in an Escherichia coli strain using a new resveratrol O-methyltransferase from Arabidopsis.

Background: Pterostilbene, a structural analog of resveratrol, has higher oral bioavailability and bioactivity than that of the parent compound; but is far less abundant in natural sources. Thus, to efficiently obtain this bioactive resveratrol analog, it is necessary to develop new bioproduction systems.

Results: We identified a resveratrol O-methyltransferase (ROMT) function from a multifunctional caffeic acid O-methyltransferase (COMT) originating from Arabidopsis, which catalyzes the transfer of a methyl group to resveratrol resulting in pterostilbene production.