Stereoselective Unsymmetrical 1,1-Diborylation of Alkynes with a Neutral sp2 -sp3 Diboron Reagent.

The incorporation of two distinct boryl groups at the same carbon center in organic molecules has attracted growing research interest due to its potential for facilitating controlled, precise synthesis through stepwise dual carbon-boron bond transformations. Here we report a method to access unsymmetrical 1,1-diborylalkene (UDBA) stereoselectively via the reaction of readily available alkynes with a neutral sp2 -sp3 diboron reagent (NHC)BH2 -Bpin (NHC=N-heterocyclic carbene). Attributing to the chemically easily distinguishable nature of the sp2 and sp3 boryl moieties, controllable stepwise derivatization of the resultant UDBAs is realized. This process leads to various multifunctionalized olefins and organoborons, such as acylboranes, which are difficult to prepare by other methods.

Selective multifunctionalization of N-heterocyclic carbene boranes via the intermediacy of boron-centered radicals.

The selective difunctionalization of N-heterocyclic carbene (NHC) boranes with alkenes has been achieved via decatungstate and thiol synergistic catalysis. The catalytic system also allows stepwise trifunctionalization, leading to complex NHC boranes with three different functional groups which are challenging to prepare by other methods. The strong hydrogen-abstracting ability of the excited decatungstate enables the generation of boryl radicals from mono- and di-substituted boranes for realizing borane multifunctionalization. This proof-of-principle research provides a new chance for fabricating unsymmetrical boranes and developing boron-atom-economic synthesis.

Orbital schwannoma with hyposmia as the only presentation: Case report and a literature review on differential diagnosis.

Orbital schwannoma is a rare benign tumor, originating from the Schwann cells of the orbital peripheral nerve sheath. Orbital schwannoma is easily misdiagnosed if the patient shows atypical presentations and atypical appearance on MRI imaging. A 56-year-old male experienced hyposmia for 1 year and was misdiagnosed with cavernous hemangioma pre-operation. This case was treated by surgery through the endoscopic trans-nasal approach. After operation, the patient had no recurrence or complications. Preoperative diagnosis for these cases remains difficult. Combined imaging modalities including computed tomography (CT) and magnetic resonance imaging (MRI) can help in differential diagnosis. Surgery is the main treatment modality for treating orbital schwannoma. Outcomes in most cases are favorable without complications or recurrence.

[Establishment of an in vitro model of alveolar macrophage cell efferocytosis dysfunction].

OBJECTIVE: To screen the time points of high survival rate and efferocytosis dysfunction of rat alveolar macrophages stimulated by cigarette smoke extract (CSE), establish an in vitro model of alveolar macrophage efferocytosis function, and study chronic respiratory diseases with chronic inflammatory reaction as the main pathological changes. METHODS: (1) Time point screening experiment: rat alveolar macrophages (NR8383 cells) were cultured in vitro, and the cells in logarithmic growth phase were divided into blank control group (100 µL complete medium) and 5% CSE group (90 µL complete medium + 10 µL 100% CSE). Alma blue method was used to detect the effect of 5% CSE on the activity of NR8383 cells at 6, 12, 24 and 48 hours. (2) Apoptosis induction experiment: rat type II alveolar epithelial cells (RLE-6TN cells) were cultured in vitro as phagocytic target cells of NR8383 cells, and the cells in logarithmic growth phase were divided into blank control group and 10, 30 and 60 minutes groups after ultraviolet exposure (apoptosis was induced by 30 000 µJ/cm2 ultraviolet irradiation for 15 minutes). Flow cytometry was used to detect the apoptosis rate of RLE-6TN cells cultured for 10, 30 and 60 minutes after ultraviolet exposure. (3) Cell efferocytosis experiment: NR8383 cells in logarithmic phase were divided into blank control group and 5% CSE group. Two hours before NR8383 cells were stimulated by CSE for 6, 12 and 24 hours, RLE-6TN cells were exposed to ultraviolet to induce apoptosis, and the RLE-6TN cell suspension was added to NR8383 cells (the ratio of RLE-6TN cells to NR8383 cells was 5:1). Flow cytometry was used to detect the efferocytosis rate of NR8383 cells to RLE-6TN cells at different time points treated with 5% CSE. RESULTS: (1) Compared with the blank control group, the activity of NR8383 cells significantly decreased after treatment with 5% CSE for 48 hours [cell reduction rate: (68.5±4.1)% vs. (73.6±2.3)%, P < 0.05]. However, there were no significant differences when the activities of NR8383 cells treated with 5% CSE for 6, 12 and 24 hours were compared with the blank control group, so these three time points were selected for the subsequent establishment of alveolar macrophage cell efferocytosis dysfunction in vitro model experiment. (2) Compared with the blank control group, the apoptosis rate of RLE-6TN cells significantly increased at 10, 30 and 60 minutes after ultraviolet exposure [(66.87±8.63)%, (85.51±2.39)%, (96.13±2.74)% vs. (9.13±3.17)%, all P < 0.01] in a time-dependent manner. Considering that it taked about 50 minutes for RLE-6TN cells to be labeled with PKH26 membrane labeling probe, 10 minutes after ultraviolet exposure was selected to label RLE-6TN cells. (3) Compared with the blank control group, the efferocytosis function of NR8383 cells was significantly decreased after treatment with 5% CSE for 12 hours [cell efferocytosis rate: (33.64±1.30)% vs. (44.02±2.71)%, P < 0.01], but there was no significant effect on the efferocytosis function of NR8383 cells at 6 hours and 24 hours. CONCLUSIONS: CSE can induce alveolar macrophage cell efferocytosis dysfunction. Based on the test results of the effect of 5% CSE on NR8383 cell activity and cell efferocytosis function, 12 hours with high survival rate and weak efferocytosis effect of NR8383 cells can be selected as the in vitro model condition of alveolar macrophage cell efferocytosis dysfunction.

Screening for deafness-associated mitochondrial 12S rRNA mutations by using a multiplex allele-specific PCR method.

Mitochondrial 12S rRNA A1555G and C1494T mutations are the major contributors to hearing loss. As patients with these mutations are sensitive to aminoglycosides, mutational screening for 12S rRNA is therefore recommended before the use of aminoglycosides. Most recently, we developed a novel multiplex allele-specific PCR (MAS-PCR) that can be used for detecting A1555G and C1494T mutations. In the present study, we employed this MAS-PCR to screen the 12S rRNA mutations in 500 deaf patients and 300 controls from 5 community hospitals. After PCR and electrophoresis, two patients with A1555G and one patient with C1494T were identified, this was consistent with Sanger sequence results. We further traced the origin of three Chinese pedigrees. Clinical evaluation revealed variable phenotypes of hearing loss including severity, age at onset and audiometric configuration in these patients. Sequence analysis of the mitochondrial genomes from matrilineal relatives suggested the presence of three evolutionarily conserved mutations: tRNACys T5802C, tRNALys A8343G and tRNAThr G15930A, which may result the failure in tRNAs metabolism and lead to mitochondrial dysfunction that was responsible for deafness. However, the lack of any functional variants in GJB2, GJB3, GJB6 and TRMU suggested that nuclear genes may not play active roles in deafness expression. Hence, aminoglycosides and mitochondrial genetic background may contribute to the clinical expression of A1555G/C1494T-induced deafness. Our data indicated that the MAS-PCR was a fast, convenience method for screening the 12S rRNA mutations, which was useful for early detection and prevention of mitochondrial deafness.

Middle ear structure and transcanal approach appropriate for middle ear surgery in rabbits.

The current study aimed to investigate the middle ear structure and surgical approach appropriate for middle ear surgery in rabbits. A total of eight healthy New Zealand rabbits (16 ears) were dissected under a surgical microscope. The dimensions of the auditory canal and the middle ear were measured. In the present study, the transcanal surgical approach to the middle ear in rabbits was performed without complications, the anatomical landmarks in the auricle and the external auditory canal were apparent, no large vessels were present in the surgical zone and the bleeding was minor. Furthermore, the surgical procedure did not require removal of large bone sections of the external auditory canal. Additionally, the constitution of the ossicular chain, the leverage ratio of the ossicular chain and the constitution of ligaments and muscles in rabbits were similar to humans. Otherwise, the facial nerve canal in rabbits was more prominent compared with humans and the mobility of pars flaccida in rabbits was more noticeable compared with humans. The results of the current study indicate that the transcanal surgical approach was suitable to study the middle ear in rabbits. Furthermore, the rabbit middle ear may be used as a model for ossicular surgery and facial nerve research.

Analysis of miRNA expression profiling identifies miR-214-3p as a novel biomarker in sinonasal inverted papilloma.

AIM: To analyze the expression profile, diagnostic and clinicopathological significances of miRNAs in sinonasal inverted papilloma (SNIP). MATERIALS & METHODS: The expression profile of miRNAs was analyzed using a miRNA microarray approach. The potential functions and clinical significances of specific miRNAs were further analyzed by bioinformatics and statistical methods. RESULTS: The microarray assay identified 37 significantly upregulated and 21 downregulated miRNAs in SNIP. Of nine miRNAs randomly selected, the expression levels of seven miRNAs were confirmed by quantitative real-time PCR. The potential target genes of several candidate miRNAs were enriched in some biological processes and cellular signaling pathways related to tumorigenesis. Receiever operating characteristic curve analysis for miR-214-3p indicated an area under the curve of 0.932. Notably, its expression level was significantly decreased in SNIP tissues and associated with SNIP staging and recurrence. CONCLUSION: MiR-214-3p can possibly serve as a valuable biomarker and a therapeutic target for SNIP.