Catalytic, enantioselective additions of a trichlorosilyl ketene acetal to ketones have been demonstrated. The trichlorosilyl enolate of methyl acetate undergoes a rapid and high-yielding aldol addition to a wide range of ketones (aromatic, olefinic, acetylenic, aliphatic) in the presence of a catalytic amount of pyridine N-oxide. Moreover, in the presence of a catalytic amount (10 mol %) of a chiral bispyridine bis N-oxide (possessing both axial and central chiral elements) the aldol addition takes place again in excellent yield and with good stereoselectivity. The enantioselectivities of the additions are highly variable (7−86% ee) and are strongly dependent on the structure of the ketone acceptor. Aromatic methyl ketones gave the highest selectivity, whereas olefinic ketones were the least selective.
This study aimed to examine the clinical characteristics and outcomes of patients with estrogen receptor-negative (ER-)/progesterone receptor-positive (PR+) early breast cancer. We also aimed to investigate the benefits of adjuvant endocrine therapy (ET) in this patient population.Patients with early breast cancer diagnosed at West China Hospital were divided into the ER-/PR+, ER+, and ER-/PR- groups. The chi-square test was used to analyze differences in clinical and pathological features among the groups. Multivariable Cox and Fine-Gray regression models were used to compare mortality and locoregional recurrence (LRR)/distant recurrence (DR), respectively. We performed a subgroup analysis to determine which ER-/PR+ patients can benefit more from ET.From 2008 to 2020, we enrolled 443, 7104, and 2892 patients into the ER-/PR+, ER+, and ER-/PR- groups, respectively. The ER-/PR+ group showed more unfavorable clinical features and aggressive pathological characteristics than the ER+ group. The mortality, LRR, and DR rates were higher in the ER-/PR+ than in the ER+ group. Most clinical features and pathological characteristics were similar between the ER-/PR+ and ER-/PR- group and their outcomes were comparable. In the ER-/PR+ group, patients who received ET showed significantly lower LRR and mortality rates than those who did not; however, no difference was observed in DR. Subgroup analysis suggested that ER-/PR+ patients age ≥ 55 years, and postmenopausal status can benefit from ET.ER-/PR+ tumors have more aggressive pathological characteristics and more unfavorable clinical features than ER+ tumors. ET can reduce the LRR and mortality rates in ER-/PR+ patients. Postmenopausal and age ≥ 55 years ER-/PR+ patients can benefit from ET.
To explore the feasibility of CT attenuation value (CTvalue) to predict the composition of upper urinary calculi and the number of shock waves (NSW) and success rate (SR) of extracorporeal shock wave lithotripsy (ESWL).A total of 146 patients with upper urinary calculi treated by ESWL were included. CT scan was performed before ESWL. Upper urinary calculi with the maximum diameters of less than or equal to 2 cm were included. Infrared spectroscopy was used to analyze the composition of calculi. The effect of ESWL was estimated at 1 month followup. The factors that influence NSW and SR of ESWL were analyzed by correlation analysis.The CTvalue of calcium calculi were larger than that of noncalcium calculi ( P<0.001). The differences of NSW,SR of ESWL and CTvalues of calculi between the patients with different ages,skintostone distances and genders were not statistically significant. The partial correlation analysis found that CTvalue and long diameter of calculi were positively correlated with the NSW ( P<0.05). This result was consistent in subgroup analysis (stone site: kidney or ureter). CTvalue and long diameter of calculi were negatively correlated with SR of ESWL ( P<0.05). However,the CTvalue of ureteral calculi was not correlated with SR of ESWL in subgroup analysis.The power of CTvalue to predict upper urinary calculi composition is insufficient. Higher CTvalue suggests more NSW in ESWL,but CTvalue is not suitable to predict SR of ESWL.
The first, catalytic, enantioselective alpha-additions of isocyanides to aldehydes have been demonstrated (Passerini-type reactions). The catalytic system of silicon tetrachloride and a chiral bisphosphoramide 5a provided high yields and good to excellent enantioselectivities for the addition of tert-butyl isocyanide to a wide range of aldehydes (aromatic, olefinic, acetylenic, aliphatic). Aqueous workup afforded the alpha-hydroxy tert-butyl amides, whereas methanolic quench followed by basic workup afforded the alpha-hydroxy methyl esters.
[4519-10-2] C3H5Cl3O2Si (MW 207.52) InChI = 1S/C3H5Cl3O2Si/c1-3(7-2)8-9(4,5)6/h1H2,2H3 InChIKey = LMVJWNCKICXPHV-UHFFFAOYSA-N (reagent for the enantioselective acetate aldol additions to aldehydes1 and ketones2) Physical Data: bp 25 °C (5 mmHg), d20 = 1.3144 g dm−3 Solubility: soluble in halogenated organic solvents such as methylene chloride, chloroform, carbon tetrachloride; sparingly soluble in hydrocarbon and ethereal solvents. Analysis of Reagent Purity: 1H NMR and elemental analysis. Preparative Methods: two different routes have been developed for the preparation of methyl trichlorosilyl ketene acetal. One route is through bis(tributyltin) oxide-catalyzed transmetalation of methyl tributylstannyl acetate 2 with silicon tetrachloride (eq 1).3 When the reaction is complete, excess silicon tetrachloride is removed and the product is purified by fractional distillation under reduced pressure. (1) Alternatively, methyl trimethylsilylacetate 3 can be converted to 1 cleanly when trichlorosilyl triflate is used (eq 2).3 This route has the advantage of not using toxic tin compounds. However, due to the similar boiling point, a complete removal of trimethylsilyl trifluoromethanesulfonate by-product 4 from 1 by fractional distillation is difficult. This method is therefore suitable only for use when 4 does not interfere with the subsequent reaction of 1. (2) Handling, Storage, and Precautions: methyl trichlorosilyl ketene acetal is a thermally unstable and hydrolytically labile compound, which is best used immediately after its preparation. The thermal rearrangement to the C-silyl isomer occurs rapidly at 70 °C4 and proceeds steadily albeit slowly at room temperature. If its storage is unavoidable, it must be kept at the lowest possible temperature. Its hydrolytic decomposition is instantaneous and anhydrous conditions are required for all the manipulations. This reagent is volatile and corrosive. Good ventilation and personal protection equipment are required for its handling.
Abstract The overexpression of membrane-bound complement regulatory proteins (mCRPs) on tumour cells helps them survive complement attacks by suppressing antibody-mediated complement-dependent cytotoxicity (CDC). Consequently, mCRP overexpression limits monoclonal antibody drug immune efficacy. CD55, an mCRP, plays an important role in inhibiting antibody-mediated CDC. However, the mechanisms regulating CD55 expression in tumour cells remain unclear. Here, the aim was to explore CD55-targeting miRNAs. We previously constructed an in vitro model comprising cancer cell lines expressing α-gal and serum containing natural antibodies against α-gal and complement. This was used to simulate antibody-mediated CDC in colon cancer cells. We screened microRNAs that directly target CD55 using LoVo and Ls-174T colon cell lines, which express CD55 at low and high levels, respectively. miR-132-3p expression was dramatically lower in Ls-174T cells than in LoVo cells. miR-132-3p overexpression or inhibition transcriptionally regulated CD55 expression by specifically targeting its mRNA 3ʹ-untranslated regions. Further, miR-132-3p modulation regulated colon cancer cell sensitivity to antibody-mediated CDC through C5a release and C5b-9 deposition. Moreover, miR-132-3p expression was significantly reduced, whereas CD55 expression was increased, in colon cancer tissues compared to levels in adjacent normal tissues. CD55 protein levels were negatively correlated with miR-132-3p expression in colon cancer tissues. Our results indicate that miR-132-3p regulates colon cancer cell sensitivity to antibody-mediated CDC by directly targeting CD55. In addition, incubating the LoVo human tumour cell line, stably transfected with the xenoantigen α-gal, with human serum containing natural antibodies comprises a stable and cheap in vitro model to explore the mechanisms underlying antibody-mediated CDC.
1,3- N , Si -Tetraorganosilane reagents TsHNCH 2 SiBnR 1 R 2 were developed as robust synthons to prepare 3-silaindolines via a Cs 2 CO 3 -promoted (3 + 2)-annulation reaction with arynes.
Innate immunity serves as the frontline to combat invading pathogens. Oral microbiota is the total collection of microorganisms colonized within the oral cavity. By recognizing the resident microorganisms through pattern recognition receptors, innate immunity is capable of interacting with oral microbiota and maintaining homeostasis. Dysregulation of interaction may lead to the pathogenesis of several oral diseases. Decoding the crosstalk between oral microbiota and innate immunity may be contributory to developing novel therapies for preventing and treating oral diseases.This article reviewed pattern recognition receptors in the recognition of oral microbiota, the reciprocal interaction between innate immunity and oral microbiota, and discussed how the dysregulation of this relationship leads to the pathogenesis and development of oral diseases.Many studies have been conducted to illustrate the relationship between oral microbiota and innate immunity and its role in the occurrence of different oral diseases. The impact and mechanisms of innate immune cells on oral microbiota and the mechanisms of dysbiotic microbiota in altering innate immunity are still needed to be investigated. Altering the oral microbiota might be a possible solution for treating and preventing oral diseases.
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