Relationships of superior mesenteric artery hemodynamic indexes with lower gastrointestinal tract symptoms scales in patients with type 2 diabetes / 中国实用内科杂志

OBJECTIVE: To study the association between superior mesenteric artery hemodynamic indexes and scores of lower gastrointestinal symptoms rating scales(LGSRS) in patients with type 2 diabetic mellitus. METHODS: Totally 142 inpatients with type 2 diabetes with average age of 58.76±12.32 yrs were enrolled, who were treated from August 2016 to March 2018. The history, gender, age,course and BMI were recorded, and fasting blood glucose(FBG), glycosylated hemoglobin(HbA1c), 2-hour postprandial blood glucose(PBG), total cholesterol(TC), triglyceride(TG), urine ACR and LGSRS were determined. Ultrasonic scanning of mesenteric artery was performed for hemodynamic indexes, including artery inner diameter(ID), peak systolic velocity(PSV), end-diastolic velocity(EDV), and resistance index(RI)at starting part,first level branch, and second level branch from root of the superior mesenteric artery(SMA).Patients were divided into 2 groups according to their LGSRS, 74 patients with LGSRS≥6 were in positive group, and 68 patients with LGSRS0.05), but the age and DD were significantly higher in positive group than in control group(P0.05). 3. There were no significant difference between positive group and control group in ID at starting part and first level branch of SMA, while ID at second level branch was significantly increased in positive group compared with control group [(3.83±0.85)mm vs.(3.53±0.90)mm, P<0.05)].4. RI at first(0.816±0.059 vs 0.842±0.063,P<0.05) and second level branch(0.813±0.076 vs 0.845±0.073, P<0.05) and PSV at first level branch[(110.89±46.89)cm/s vs(95.72±36.59)cm/s,P<0.05] were significantly high in positive group; there were no difference in other hemodynamic indexes between the groups. 5.Adjusted by age,DD,glycemic and lipidemic profile,Logistic regression showed that ID at first(RR=2.092,95%CI 1.080-4.050,P=0.029) and second level branch(RR=0.491,95%CI 0.252-0.955,P=0.36) and EDV at second level branch(RR=0.897,95%CI 0.824-0.976,P=0.012) were independent factors influencing LGSRS(P<0.05). CONCLUSION: Ultrosonic hemodynamic abnormalities in the superior mesenteric artery might be important factor in development of lower gastrointestinal tract symptoms in patients with type 2 diabetes.

Construction of antisense Bmi-1 expression plasmid and its inhibitory effect on K562 cells proliferation / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Bmi-1 gene determines the proliferative capacity of normal and leukemia stem cells. Expression of Bmi-1 has been found in all types of myeloid leukemia cells in both humans and mice. This study aimed at assessing the effect of antisense Bmi-1 expression on K562 cells proliferation and p16 protein (p16) expression.</p><p><b>METHODS</b>A transcriptional repressor, Bmi-1 cDNA was cloned by reverse transcriptase polymerase chain reaction (RT-PCR) of its mRNA from K562 cells. A plasmid expressing antisense Bmi-1 mRNA was then constructed by reverse design of PCR primers and cloned to the plasmid pLNCX2; G418 was added to the medium after the plasmid was successfully introduced in K562 cells by lipofectin-mediated DNA transfection. The effects of the antisense expression on the proliferation of K562 cells were analyzed by using microculture tetrazolium and colony forming. Cell cycle was analyzed by using flow cytometry. The p16 expression of K562 cells was observed by immunofluorescence histochemical stain.</p><p><b>RESULTS</b>K562 cells transfected with antisense Bmi-1 plasmid grew significantly slower than that of controls (the parental K562 and cells transfected with empty plasmid). The colony forming ability of antisense Bmi-1 plasmid transfected cells decreased significantly (P < 0.01) compared with controls. The p16 expression of cells transfected with antisense Bmi-1 was upgraded more apparently than that of controls.</p><p><b>CONCLUSION</b>The antisense Bmi-1 gene can inhibit the growth of K562 cell and upgrade expression of p16 in K562 cells.</p>

A single tetracycline-regulated vector devised for controlled insulin gene expression / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To construct a single plasmid vector mediating doxycycline-inducible recombined human insulin gene expression in myotube cell line.</p><p><b>METHODS</b>An expression cassette of rtTAnls driven by promoter of human cytomegalovirus and a furin-cuttable recombined human insulin expression cassette driven by a reverse poly-tetO DNA motif were cloned into a single plasmid vector (prTR-tetO-mINS). The prTR-tetO-mINS and pLNCX were co-transfected into a myotube cell line (C2C12) and pLNCX vector were used as a control. After selection with G418, the transfected cells were induced with doxycycline at concentrations of 0, 2, and 10 microg/mL. RT-PCR was used to determine expression levels of recombinant insulin mRNA at the 5th day. Insulin production in cell cultures medium (at different incubation time) and cell extracts (at the 7th day) were analyzed with human pro/insulin RIA kits.</p><p><b>RESULTS</b>Immune reactive insulin (IRI) level in cell medium was found increased at 24 hours of doxycycline incubation, and still increased at the 5th day. After withdrawn of doxycycline, IRI decreased sharply and was at baseline three days later. IRI and human insulin mRNA levels were positively related to different levels of doxycycline. A 25-fold increase in IRI was found against background expression at the 7th day.</p><p><b>CONCLUSION</b>Human insulin expression can be successfully regulated by doxycycline and the background was very low. This single tet-on insulin expression system may provide a new approach to a controlled insulin gene therapy in skeletal muscle.</p>

Construction of antisense telomerase hTERT and its effect on K562 cells / 中华血液学杂志

<p><b>OBJECTIVES</b>To investigate whether antisense human telomerase reverse transcriptase (hTERT) could inhibit the activity of telomerase and the proliferation of K562 cells.</p><p><b>METHODS</b>The antisense plasmid was constructed by reverse insertion of hTERT PCR product into plasmid pLNCX-neo. Then the constructed plasmid was introduced into K562 cells by liposomes-mediated DNA transfection. The inhibition effects of telomerase on the proliferation of K562 cells were analyzed by MTT and colony formation assay, the telomerase activity of K562 cells by TRAP-PCR ELISA methods.</p><p><b>RESULTS</b>The growth rate of antisense hTERT transfected K562 cells was significantly lower than those of the controls, and the colony formation capacity of the transfected cells decreased significantly (P < 0.01), the colony number is (100.33 +/- 7.57)/10(3) cells, (92.67 +/- 5.86)/10(3) cells and (50.33 +/- 6.11)/10(3) cells for control K562 cells, K562 neo cells and antisense hTERT transfected HL60 cells, respectively. The telomerase activity of antisense hTERT transfected K562 cells was significantly inhibited.</p><p><b>CONCLUSION</b>The expression of an antisense sequence to the mRNA sequence of telomerase protein subunit can inhibit the activity of telomerase, slow the cell growth and inhibit the capacity of colony formation of K562 cells.</p>