Construction and in vitro evaluation of an LNP system for mRNA delivery / 药学实践杂志

Objective To construct lipid nanoparticles DLin-LNP for mRNA delivery. Methods DLin-LNP was prepared by thin film hydration method, and DLin-LNP/mRNA was further constructed by using EGFP-mRNA as model drug. The particle size, zeta potential, and appearance morphology were measured. Furthermore, the intracellular distribution and transfection of DLin-LNP/mRNA in RM-1 cells was investigated by laser scanning confocal microscope. Results DLin-LNP was successfully prepared. The average particle size was about (151.1±2.1) nm, the no-load potential was (23.7±0.5) mV. The cytotoxicity of DLin-LNP was far lower than that of the commercially available liposomal Lipo8000. The results of transfection experiment indicated that DLin-LNP has high transfection efficiency for mRNA delivery with low cytotoxicity and good stability. Conclusion DLin-LNP could become a potential mRNA vector for gene therapy.

Effects of arsenic and its metabolites on expressions of BCL-2α and BCL-2β transcripts / 环境与职业医学

Background Arsenic is a toxicant that can affect the expressions of the cellular anti-apoptotic gene BCL-2 and its protein, but the effects of arsenic on BCL-2α and BCL-2\begin{document}$\beta $\end{document} transcripts have not been reported. Objective To investigate the potential effects of arsenic and its metabolites, methylarsonic acid (MMA) and dimethylarsonic acid (DMA), on BCL-2α, BCL-2\begin{document}$\beta $\end{document}, and BCL-2T (total of α and \begin{document}$\beta $\end{document} transcripts) in human bronchial epithelial cells (16HBE) and human lung adenocarcinoma cells (A549). Methods 16HBE cells and A549 cells were randomly divided into three categories of exposure after in vitro culture: single-selected arsenic compound exposure groups with isoconcentration (16HBE cells were treated with 4.5 μmol·L−1 of MMA, DMA, and sodium arsenite, respectively, while A549 cells were treated with 60 μmol·L−1 of MMA, DMA, and sodium arsenite, respectively), sodium arsenite exposure groups with different concentrations (16HBE cells were treated with 1.5, 3.0, and 4.5 μmol·L−1 of sodium arsenite respectively, while A549 cells were treated with 20, 40, and 60 μmol·L−1 of sodium arsenite respectively), and combined exposure groups (i.e. MMA+sodium arsenite, and DMA+sodium arsenite; the exposure concentrations of 16HBE cells were both 1.5 μmol·L−1 and both 4.5 μmol·L−1 respectively, and those of A549 cells were both 20 μmol·L−1 and both 60 μmol·L−1 respectively). Meanwhile, a blank control group was also set up in each exposure category. After 48 h of continuous exposure, the relative expressions of BCL-2α, BCL-2\begin{document}$\beta $\end{document}, and BCL-2T in both cells were detected by real-time PCR. Results Regarding the single-selected arsenic compound exposure, in 16HBE cells, the expression levels of BCL-2α and BCL-2T under 4.5 μmol·L−1 MMA treatment were lower than those in their control groups (q=3.27, 2.93, both P<0.05), and the expression levels of BCL-2α, BCL-2\begin{document}$\beta $\end{document}, and BCL-2T under 4.5 μmol·L−1 sodium arsenite were lower than those in their respective control groups (q=11.06, 3.65, 10.70, all P<0.05). In A549 cells, the expression level of BCL-2T treated with 60 μmol·L−1 DMA was lower than that in the control group (q=3.12, P<0.05), and the expression levels of BCL-2α, BCL-2\begin{document}$\beta $\end{document}, and BCL-2T treated with 60 μmol·L−1 sodium arsenite were lower than those in their respective control groups (q=7.59, 7.27, 8.06, all P<0.05). Regarding the sodium arsenite exposure: 16HBE cells treated with 1.5 μmol·L−1 sodium arsenite had a lower expression level of BCL-2α and a higher expression level of BCL-2\begin{document}$\beta $\end{document} than those in their respective control groups (q=6.06, 11.92, both P<0.05); the expression level of BCL-2α under 3.0 μmol·L−1 sodium arsenite was lower than that in the control group (q=12.72, P<0.05); and under 4.5 μmol·L−1 sodium arsenite treatment, the expression levels of BCL-2α, BCL-2\begin{document}$\beta $\end{document}, and BCL-2T were lower than those in their respective control groups (q=15.72, 6.79, 6.62, all P<0.05). The expression levels of BCL-2α gradually decreased with increasing concentrations of sodium arsenite (Fα trend=144.80, P<0.001), while BCL-2\begin{document}$\beta $\end{document} and BCL-2T decreased in a dose-dependent manner in the range of 1.5-4.5 μmol·L−1 (F\begin{document}${}_{\beta } $\end{document} trend=135.40, FT trend=38.24, both P<0.001). In A549 cells, the expression levels of BCL-2α, BCL-2\begin{document}$\beta $\end{document}, and BCL-2T under each concentration of sodium arsenite treatments were lower than those in their respective control groups (all P<0.05); the results of further trend tests showed that their expression levels gradually decreased with increasing concentrations of sodium arsenite (Fα trend =31.97, F\begin{document}${}_{\beta} $\end{document} trend=549.50, FT trend=252.40, all P<0.001). Regarding the combined exposure, under MMA+sodium arsenite treatment at both 60 μmol·L−1, the expression levels of BCL-2α, BCL-2\begin{document}$\beta $\end{document}, and BCL-2T in A549 cells were higher than those in their respective control groups (q=6.37, 14.91, 5.33, all P<0.05); under DMA+sodium arsenite treatment at both 60 μmol·L−1, their expression levels in A549 cells were also higher than those in their respective control group (q=8.60, 17.29, 6.91, all P<0.05). Conclusion Exposure to a high concentration (16HBE: 4.5 μmol·L−1, A549: 60 μmol·L−1) of a single arsenic metabolite has no effect on BCL-2 transcripts in 16HBE cells and A549 cells. Exposure to a low concentration (1.5 μmol·L−1) of sodium arsenite alone would decrease the expression level of BCL-2α and increase the expression level of BCL-2\begin{document}$\beta $\end{document} in 16HBE cells, and exposure to all designed concentrations of sodium arsenite alone would decrease the expressions of all transcripts in A549 cells. The combined exposure to high concentrations (both 60 μmol·L−1) of MMA plus sodium arsenite or high concentrations (both 60 μmol·L−1) of DMA plus sodium arsenite would increase the expressions of BCL-2α, BCL-2\begin{document}$\beta $\end{document}, and BCL-2T in A549 cells, which are different from the effects presented by single exposure.

Study of Aetiological and Endoscopic Profile of Patients with Upper Gastrointestinal Bleed in North East India - A Hospital Based Cross Sectional Study

Upper Gastro-Intestinal Bleeding (UGIB) is one of the common complaints with which patients present to casualty. It is associated with significant morbidity and mortality. The aetiological spectrum of UGIB is variable in different geographical regions. Our study aimed to analyse the aetiology, endoscopic profile, mortality, Rockall score and predictors of mortality in patients with UGIB, in North East India. METHODSThis cross-sectional study was conducted at Assam Medical College and Hospital in North East India. We enrolled patients with age 12 years and above, who were admitted between July 2019 and January 2020 with a history suggestive of UGIB. Demographic data of the patients was collected, after which they underwent clinical examination, and upper GI endoscopy. Mean ± standard deviation was used to express continuous variables. Frequency and percentage were used to express categorical variables. Test of significance for qualitative data was assessed by Chi-square test (for 2 x 2 tables). P value less than 0.05 was taken as statistically significant. RESULTSWe analysed 117 patients diagnosed with UGIB [80.34 % male, 19.60 % female], ratio of male to female of [4.08:1] was seen. The most common symptom was melena 87 patients (74.15 %), endoscopy finding showed that 48.71 % had oesophageal and / or gastric varices, 26.49 % had peptic ulcers, 17.94 % had gastric erosions / duodenal erosions / erosive gastritis, 1.7 % had Mallory-Weiss tear, 1.7 % had gastric malignancy, 1.7 % had GJ stoma bleed, 1.7 % had both oesophageal varices and peptic ulcer disease. Partial gastric outlet obstruction was observed in peptic ulcer disease in 2 patients (6.45 % of total peptic ulcer disease patients). 73.75 % patients had Rockall score < 5 and 26.49 % patients had Rockall score > 6. H. pylori infection (assessed by RUT) was an independent predictor of upper GI bleed in both variceal and non-variceal bleed [p < 0.001]. The mortality in our study was 7.69 %. Predictors of mortality in the study population were, patients with variceal bleed [p = < 0.001], Rockall score > 6 [p = 0.013], and chronic liver disease [p < 0.001]. The average duration of hospital admission of the study population is about 4.6 + / - 0.4 days. CONCLUSIONSThe study reported oesophageal varices was the most common cause of UGIB, followed by peptic ulcer in North East India. H. pylori was an independent predictor of both variceal and non-variceal bleed. Partial gastric outlet obstruction (GOO) was one of the common benign complication of peptic ulcer disease. Variceal bleed, Rockall score > 6, chronic liver disease were predictors of mortality.

Determination of arsenic species in serum, liver, kidney, and spleen of realgar nanoparticles treated rats by HPLC-ICP-MS / 中草药

Objective Quantitative analysis of four arsenic species As (III), As (V), monomethyl arsenate (MMA), dimethyl arsenate (DMA) in rat serum, liver, kidney, and spleen was performed to compare their differences between realgar and realgar nanoparticles (NPs) groups. Methods SD rats were ig treated with blank solvent, realgar, and realgar NPs (800 mg/kg) respectively. After 28 d of continuous administration, serum and tissues were collected and four arsenic species were determined by high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS). Results Four arsenic species were detected in serum and kidney of rats, three were detected in the liver and two in the spleen. The content of arsenic species in the realgar NPs group was significantly higher than that in the realgar group. Conclusion Nanotechnology enhanced the bioavailability of realgar, and more arsenic was absorbed into the body and underwent metabolic transformation, which might lead to increased toxicity of realgar NPs.

Testis-mediated gene transfer in mice: comparison of transfection reagents regarding transgene transmission and testicular damage

Testis-mediated gene transfer (TMGT) has been used as in vivo gene transfer technology to introduce foreign DNA directly into testes, allowing mass gene transfer to offspring via mating. In this study, we used plasmid DNA (pEGFP-N1) mixed with dimethylsulfoxide (DMSO), N,N-dimethylacetamide (DMA) or liposome (Lipofectin) in an attempt to improve TMGT. Males receiving consecutive DNA complex injections were mated to normal females to obtain F0 progeny. In vivo evaluation of EGFP expression, RT-PCR and PCR were used to detect the expression and the presence of exogenous DNA in the progeny. We also evaluated possible testicular damage by histological procedures. PC R and RT-PCR analyses revealed that liposome and DMSO increased the rate of TMGT. Histological analyses demonstrated that repeated (4 times) injections of DNA complexes can affect spermatogenesis. DMSO was the most deleterious among the reagents tested. In this study, we detected the presence of transgene in the progeny, and its expression in blood cells. Consecutive injections of DNA complexes were associated with impaired spermatogenesis, suggesting requirement of optimal conditions for DNA delivery through TMGT.

Positive inotropic action of dimethylamiloride in normal rat isolated hearts and papillary muscle and its primary mechanism / 中国药理学通报

Aim To study the inotropic action of DMA in normal rat isolated hearts and papillary muscle and search for its primary mechanism.Methods With Lansendorff-perfusion and isolated papillary muscle perfusion,cardiac performance and the systolic function of papillary muscle were measured to estimate the inotropic action of DMA;L-calcium channel blocker and sodium calcium exchanger(NCX)inhibitor were used to search for its primary mechanism.Results ①(1~20)?mol?L-1 DMA exerted a positive inotropic action in normal rat isolated hearts,that is in Langendorff-perfused hearts,DMA enhanced cardiac performance,i.e.LVSP-LVDP,+dp/dtmax,-dp/dtmax significantly(P

The effects and mechanisms of dimethylamiloride on cardiac function in cardiomegaly rat isolated hearts / 中国药理学通报

Aim To investigate the effects and mechanisms of DMA on cardiac function in cardiomegaly rat isolated hearts.Methods With Langendorff perfusion,the changes in the indicators reflecting cardiac function were observed in cardiomegaly rat isolated hearts.Its probable mechanism was explored with calcium channel blocker and sodium calcium exchange(NCX) blockers.Results DMA(0.5～2 ?mol?L~(-1))enchanced cardiac function and exerted positive effects on LVSP-LVDP,+dp/dt_(max)and-dp/dt_(max) in Langendorff-perfused cardiomegaly rat isolated hearts.The effects of DMA on cardiac function in cardiomegaly rat isolated hearts weren′t blocked by nicardipine-one of calcium channel blockers and were blocked by NiCl_2——one of sodium calcium exchange(NCX) blockers.Conclusion DMA can enhance systolic and diastolic function in cardiomegaly rat isolated hearts.By agitating NCX,DMA enhances cardiac function in cardiomegaly rat isolated hearts,independent of L-calcium channel.