Enantioselective Synthesis of 2,3,3a,8a-Tetrahydrofuro[2,3-b]benzofuran Scaffolds Enabled by Cu(II)/SPDO-Catalyzed [3+2] Cycloaddition of 2,3-Dihydrofuran and Quinone Esters.

An asymmetric [3+2] cycloaddition of quinone esters with 2,3-dihydrofuran has been realized via a newly developed Cu(II)/SPDO complex. It provides straightforward access to 2,3,3a,8a-tetrahydrofuro[2,3-b]benzofurans (TFB) with high enantioselectivity (up to 97.5:2.5 er) and diastereoselectivity (all >20:1 dr). The resulting adducts contain two adjacent stereocenters and a continuously functionalized benzene ring. Additionally, this transformation could be easily performed on a gram scale, allowing for expedient synthesis of natural dihydroaflatoxin D2 and aflatoxin B2.

Clinical diagnosis and treatment of primary thyroid tuberculosis: a retrospective study

ABSTRACT BACKGROUND: Primary thyroid tuberculosis (PTT) is an uncommon type of extrapulmonary tuberculosis, which is caused by Mycobacterium tuberculosis. It does not have specific clinical manifestations, and most cases are diagnosed through postoperative histopathological examination. OBJECTIVE: To evaluate the diagnostic pattern and management strategy among patients with primary thyroid tuberculosis. DESIGN AND SETTING: Retrospective study on patients with primary thyroid tuberculosis in the First Hospital of Jilin University (Changchun, China). METHODS: Between March 2015 and June 2020, nine cases of PTT were diagnosed and treated in the Department of Thyroid Surgery of the First Hospital of Jilin University. Age at diagnosis, primary symptoms, preoperative biopsy, operation method, pathological classification, acid-fast staining test, anti-TB therapy and prognosis were registered in order to explore the appropriate protocol for diagnosis and treatment of this disease. RESULTS: None of the patients was diagnosed with thyroid tuberculosis before surgery. All the patients underwent surgery. Granulomatous changes or caseous necrosis in thyroid tissue were found through postoperative histopathological evaluation. Polymerase chain reaction (PCR) results for Mycobacterium tuberculosis were positive in all patients. Most patients had a good prognosis after surgery and anti-tuberculosis drug therapy. CONCLUSION: PTT is a rare disease. It is important to improve the preoperative diagnosis. Preoperative diagnostic accuracy relies on increased awareness of the disease and appropriate use of preoperative diagnostic methods, such as PCR detection, fine-needle aspiration cytology, acid-fast bacillus culture, ultrasound and blood sedimentation. PCR detection of M. tuberculosis is recommended as the gold standard for diagnosis.

Clinical diagnosis and treatment of primary thyroid tuberculosis: a retrospective study.

BACKGROUND: Primary thyroid tuberculosis (PTT) is an uncommon type of extrapulmonary tuberculosis, which is caused by Mycobacterium tuberculosis. It does not have specific clinical manifestations, and most cases are diagnosed through postoperative histopathological examination. OBJECTIVE: To evaluate the diagnostic pattern and management strategy among patients with primary thyroid tuberculosis. DESIGN AND SETTING: Retrospective study on patients with primary thyroid tuberculosis in the First Hospital of Jilin University (Changchun, China). METHODS: Between March 2015 and June 2020, nine cases of PTT were diagnosed and treated in the Department of Thyroid Surgery of the First Hospital of Jilin University. Age at diagnosis, primary symptoms, preoperative biopsy, operation method, pathological classification, acid-fast staining test, anti-TB therapy and prognosis were registered in order to explore the appropriate protocol for diagnosis and treatment of this disease. RESULTS: None of the patients was diagnosed with thyroid tuberculosis before surgery. All the patients underwent surgery. Granulomatous changes or caseous necrosis in thyroid tissue were found through postoperative histopathological evaluation. Polymerase chain reaction (PCR) results for Mycobacterium tuberculosis were positive in all patients. Most patients had a good prognosis after surgery and anti-tuberculosis drug therapy. CONCLUSION: PTT is a rare disease. It is important to improve the preoperative diagnosis. Preoperative diagnostic accuracy relies on increased awareness of the disease and appropriate use of preoperative diagnostic methods, such as PCR detection, fine-needle aspiration cytology, acid-fast bacillus culture, ultrasound and blood sedimentation. PCR detection of M. tuberculosis is recommended as the gold standard for diagnosis.

Multiple endocrine neoplasia type 1 combined with thyroid neoplasm: A case report and review of literatures.

BACKGROUND: Multiple endocrine neoplasia type 1 (MEN1) is a rare hereditary tumor syndrome inherited in an autosomal dominant manner and presents mostly as parathyroid, endocrine pancreas (such as gastrinoma) and anterior pituitary tumors. At present, papillary thyroid carcinoma (PTC) and nodular goiter are not regarded as components of MEN1. CASE SUMMARY: A 35-year-old woman presented with MEN1 accompanied by coinstantaneous PTC and nodular goiter. The pathological diagnosis was PTC with cervical lymph node metastasis, nodular goiter, parathyroid cyst and adenomatoid hyperplasia. Genetic testing was performed and a MEN1 gene mutation was detected. The patient underwent unilateral lobectomy of the thyroid gland and surgical removal of the parathyroid tumors. At 18 mo of follow-up, ultrasonic examination of the neck showed no abnormality. Serum calcium and parathyroid hormone levels were normal. No new MEN1-associated tumors were detected. CONCLUSION: The role of inactivating mutations of MEN1 gene in tumorigenesis of PTC and/or nodular goiter remains to be determined by more case reports and further research.

Ataxia-linked SLC1A3 mutations alter EAAT1 chloride channel activity and glial regulation of CNS function.

Glutamate is the predominant excitatory neurotransmitter in the mammalian central nervous system (CNS). Excitatory amino acid transporters (EAATs) regulate extracellular glutamate by transporting it into cells, mostly glia, to terminate neurotransmission and to avoid neurotoxicity. EAATs are also chloride (Cl-) channels, but the physiological role of Cl- conductance through EAATs is poorly understood. Mutations of human EAAT1 (hEAAT1) have been identified in patients with episodic ataxia type 6 (EA6). One mutation showed increased Cl- channel activity and decreased glutamate transport, but the relative contributions of each function of hEAAT1 to mechanisms underlying the pathology of EA6 remain unclear. Here we investigated the effects of 5 additional EA6-related mutations on hEAAT1 function in Xenopus laevis oocytes, and on CNS function in a Drosophila melanogaster model of locomotor behavior. Our results indicate that mutations resulting in decreased hEAAT1 Cl- channel activity but with functional glutamate transport can also contribute to the pathology of EA6, highlighting the importance of Cl- homeostasis in glial cells for proper CNS function. We also identified what we believe is a novel mechanism involving an ectopic sodium (Na+) leak conductance in glial cells. Together, these results strongly support the idea that EA6 is primarily an ion channelopathy of CNS glia.

Copper-Nitrene-Catalyzed Desymmetric Oxaziridination/1,2-Alkyl Rearrangement of 1,3-Diketones toward Bicyclic Lactams.

Although copper-nitrene has been extensively studied as a versatile active species in various transformations, asymmetric reactions involving copper-nitrene have been limited to the aziridination of olefins. Herein, we report the novel copper-nitrene-catalyzed desymmetric oxaziridination reaction of cyclic diketones with alkyl azides and the subsequent rearrangement of the resulting highly active intermediate, which produces a synthetically challenging chiral bicyclic lactam containing a quaternary carbon center. This procedure not only enriches the copper-nitrene-catalyzed asymmetric reactions, but also provides an alternative strategy to address the inherent challenges of catalytic asymmetric Schmidt reactions. This unique reaction could inspire the investigation of novel copper-nitrene-catalyzed asymmetric transformations and their reaction mechanisms.

Inhibition of microRNA-130b Alleviated Podocyte Injury Induced by Puromycin Aminonucleoside in vitro.

OBJECTIVE: To investigate the effect of microRNA-130b (miR-130b) on podocyte injury induced by puromycin aminonucleoside (PAN) and its possible mechanisms. METHODS: The immortalized podocytes (HPC) were treated by 25, 50, or 100 µg/mL PAN, then real-time polymerase chain reaction (PCR) was used to detect the expression of miR-130b. The HPC were transfected with miR-130b inhibitor or normal control (NC) inhibitor, and then the cells were stimulated with 100 µg/mL PAN for 24h. Western blot was used to detect the protein expression of synaptopodin and nephrin. Phalloidin dying was used to detect the changes in the cytoskeleton. Flow cytometry was used to measure podocyte apoptosis. Luciferase reporter gene assays were performed to explore the interaction between miR-130b and PGC1α. RESULTS: PAN significantly upregulated the expression of miR-130b. The western blot showed that inhibition of miR-130b increased the protein expression of synaptopodin and nephrin compared to the negative control inhibitor group. The phalloidin dying showed that inhibition of miR-130b alleviated cytoskeletal remodeling of podocytes induced by PAN. Flow-cytometric analysis showed that apoptosis was decreased after miR-130b silencing. The miR-130b mimic could significantly down-regulate the protein expression of PGC1α, and the dual luciferase reporter assay showed that miR-130b induced a decrease in PGC1α 3'-UTR luciferase activity compared to the control mimic group, but there was no significant difference between the control mimic group and the mut·PGC1α 3'-UTR group. CONCLUSION: miR-130b ameliorates podocyte injury induced by PAN through inhibiting the expression of PGC1α.

[Occurrence of Antibiotics and Antibiotic Resistance Genes in Representative Drinking Water Resources in Jiangsu Province].

Emerging contaminants including antibiotics and antibiotic resistance genes (ARGs) have been frequently detected in drinking water resources. In this study, the occurrence of antibiotics and ARGs in various environmental matrices in representative drinking water sources in Jiangsu Province and their influencing factors were explored. Five representative drinking water sources in northern, central, and southern Jiangsu were selected. Water, surface sediment, and epilithic biofilm samples were harvested near the water intakes of each water resource in December 2018 and June 2019. The concentrations and abundances of ten antibiotics, one integrase gene intl1, and seven common ARGs were measured. The results suggest that the concentrations of the target antibiotics and ARGs are relatively low compared to previously reported data in China and elsewhere in the world. The target antibiotics were detected in all of the water sources. The concentrations of sulfonamides in the water, surface sediment, and epilithic biofilm ranged from not found (NF) to 37.4 ng·L-1, NF to 47.3 ng·g-1, and NF to 3759.1 ng·g-1, respectively; the concentrations of quinolones in three matrices were NF-5.3 ng·L-1, 0.4-32.5 ng·g-1, and NF-4220.9 ng·g-1, respectively. The detection rates of the ARGs including sul 1, sul2, tetW, and tetQ were 100%, among which the sulfonamides sul1 and sul2 showed the highest abundance. The absolute abundances of sul1 in the three matrices were 2.48×106 copies·L-1, 3.54×107 copies·g-1, and 1.44×109 copies·g-1, respectively. The abundances of ARGs in the sediments and epilithic biofilms were comparable, and were much higher than in the water body. The phyla Bacteroidetes, Proteobacteris, Firmicutes, Verrucobacteria, and Actinomycetes have proven potential hosts for ARGs and might play an important role in the transmission and diffusion of resistance genes. This study offers baseline information on the presence of antibiotics and ARGs in the drinking water sources of Jiangsu Province, providing a significant theoretical basis for ARGs pollution control and safety guidelines for drinking water resources.

Total synthesis of quinolactacin-H from marine-derived Penicillium sp. ENP701 and biological activities.

The quinolactacins are a family of pyrroloquinoline-type natural products from Penicillium sp. From the organic extract of Penicillium sp. ENP701 fermentation broth, a microorganism from the east China sea, one new quinolactacin was isolated and named quinolactacin-H. The structure of quinolactacin-H was determined by spectroscopic analysis and the absolute configurations by X-ray crystallographic analysis. Enantioselective total synthesis of (R)-(+)-quinolactacin-H and (S)-(-)-quinolactacin-H was achieved. When assayed through crystal violet (CV) microtiter plate biofilm, both (R) and (S)-quinolactacin-H showed a strong inhibition and dispersion of Pseudomonas aeruginosa PAO1 biofilms. Thus, quinolactacins could be proposed and developed as natural anti-bioflm agents in order to solve the problem of microbial resistance in future.

[The screening of interaction factors with BoCAL and BoAP1 related to curd formation].

CAL (CAULIFLOWER) gene and AP1 (APETALA1) gene, which both belong to MADS-box transcription factors, are involved in the development of flower apical meristem. In A rabidopsis thaliana, loss of CAL and AP1 function at the same time leads to floweral meristems proliferation indeterminately, and the plants display the cauliflower phenotype. But in cauliflower (Brasscia oleracea L. var. botrytis), the BobCAL single mutant can display the cauliflower phenotype, it is appear that CAL and AP1 homolog have different function in both plants. To study the function of homozygous CAL , AP1 protein in Brassica Species, especially their regulation function in the formation of cauliflower, we took advantage of yeast-two-hybrid method to screen interaction factors of BoCAL. We got four kinds of proteins which are separately involve in phosphorylation and dephosphorylation of proteins, proteins modifying, proteins binding-site and so on. They separately have close relationship with translation, regulation pathways and signal transferring pathways and they provide clues for the study of function of BoCAL. Additionally, we checked up the relationship between some interacting factors of BoCAL and BoAP1, some known MADS-box translation factors and BoCAL and BoAP1. The results showed that BoCAL specifically interact with SnRKbeta2. BoCAL, BoAP1 both interact with SVP, similar as the homolog in Arabidopsis. While the interaction between BoCAL, BoAP1 with FLM, SOC1 and AGL24. The data here indicate the function of homozygous BoCAL and BoAP1 differ from that in Arabidopsis thaliana.

[Analysis of shoot apical anatomic changes during the development of Brassica plants].

In this study, we analyzed shoot apical anatomic changes during the development of Brassica plants including cauliflower (Brasscia oleracea L.var. botrytis), broccoli (B. oleracea L.var italica), Chinese cabbage (Brasscia compestris spp. pekinensis) and cabbage (Brasscia oleracea.L.). It has been showed that all of their apical meristems changed from the original tunica-corpus structure to the intergrade subarea, to typical 5-subarea structure and to 4-subarea structure when they went into reproductive development. The shoot apical meristem (SAM) cells were undergoing in different developmental way among these plants after they began reproductive development. The bilateral cells of sub-tunica of Chinese cabbage and cabbage divided into apical leafy primordial, in which lateral inflorescence meristem arised. While the bilateral cells of sub-tunica of cauliflower and broccoli divided into inflorescence meristem, which proliferated into curd or head. The results presented here provide the base for further investigation of anatomic identity of inflorescence phenotype formation and molecular events associated with meristem fate.