The stability of cell genetic material is influenced by a variety of factors, both internal and external, which can cause various types of DNA damage, such as DNA alkylation, oxidation, mismatching, loop structure, atypical DNA structure, single-strand break, and double-strand break.These DNA damages disrupt cellular homeostasis and dynamic equilibrium, which cause gene mutations, chromosomal abnormalities, and even degradation, aging, and death at different biological levels.By searching and identifying DNA damage sites, the cell activates a series of biochemical pathways, coordinates the progress of DNA replication and transcription, and then repairs the DNA damage.In this way, the cell maintains its independence and stability.While radiotherapy plays a role in eliminating tumors by DNA damages, it also initiates DNA damage responses.Among the responses, base excision repair, nucleotide excision repair, mismatch repair, double-strand break repair, and post-translesion synthesis repair play a key role in repairing the damages.The dysfunction of these repair pathways will cause differences in tumor radiation sensitivity.This paper summarizes recent research results in DNA damage repair, and focuses on the types of DNA damage and their repair mechanisms, so as to promote the understanding of the great significance of this field and to provide a theoretical basis for exploring the application of DNA damage repair pathways in tumor therapy.

Objective To explore the effect of L-carnitine on panel reactive antibody (PRA) in hemodialysis patients. Methods 50 patients were classified randomly into 2 groups: L-carnitine group receiving intravenous injection of 2g L-carnitine after each hemodialysis for 6 months, and control group did not receive any L-carnitine treatment. The PRA in serum was measured by enzyme-linked immunosorbent assay (ELISA) before and after 6 months of L-carnitine treatment. Results L-carnitine significantly reduced PRA levels compared with control group(P

Objective To investigate the length of preserved ileocecum in surgical treatment of slow transit constipation ( STC) by sub-total colectomy with antiperistaltic cecorectal anastomosis .Methods A total of 82 patients with STC were divided into two groups according to the random number table method ,with 41 cases in each group ,all the patients of the two groups underwent subtotal colectomy ,intraopera-tive ileocecum was preserved length of group A was 10~15 cm,group B was 2~3 cm.The operation time,intraoperative bleeding volume, postoperative exhaust time and length of hospital stay were compared .Wexner constipation score and gastrointestinal quality of life index ,ab-dominal pain ,frequency score and emptying time of ileocecus before and after 6 months and 12 months between the two groups were com-pared.Results There was no statistically significant difference in the operation time ,intraoperative bleeding volume ,postoperative exhaust time and hospitalization time of two groups (P>0.05).Wexner constipation score,abdominal pain,frequency score of the two groups after 6 months and 12 months decreased significantly (P<0.05,P<0.01),of which the group B was lower than that of the group A (P<0.05,P<0.01). The gastrointestinal quality of life index after operation significantly increased (P<0.01),of which the group B was higher than that of the group A (P<0.01).Ileocecal emptying time of the group B 12 months after operation was shorter than that of the group A (P<0.01),the differences were statistically significant .Conclusion Subtotal colectomy with antiperistaltic cecorectal anastomosis is an effective method to treat STC,which can reduce the length of preserved ileocecum and improve the prognosis of patients .

Objective To investigate the effect of Verisyse iris-claw intraocular lens implantation on correction of high myopia.Methods9 patients with highly myopic (18 eyes and diopter between-6.75 DS to-28.00 DS) were treated with Verisyse intraocular lens implantation. All the treated eyes were observed for uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), intraocular pressure, anterior segment changes and corneal endothelium preoperatively and postoperatively.ResultsThe implantation was successfully performed in all of 18 eyes. After 3 months, 11 eyes (61.1%) had the uncorrected visual acuity (UCVA) ≥0.5; 9 eyes (50.0%) had the best corrected visual acuity (BCVA) ≥0.8. UCVA and BCVA of every eye were significant improved ( P<0.01); the mean corneal astigmatism and mean intraocular pressure were not different from preoperation ( P>0.05). In all patients, one eye was oval and 2 other eyes showed decentered phakic IOL; 2 patients (2 eyes) complained of halo and glare; no severe complications occurred.ConclusionThe implantation of Verisyse iris-claw intraocular lens for the correction of high myopia has a significantly effect.

Background and purpose: In recent years indirubin-3'-monoxime has been found to be capable of inhibiting some cell proliferation in vitro and in vivo studies, but human colon cancer HT-29 cells, therefore the purpose in this paper was to study the effect of indirubin-3'-monoxime on proliferation and apoptosis of HT-29 cells and its associated mechanism. Methods: HT-29 cells were treated with indirubin-3'-monoxime. The proliferative status of cells was measured by methabenzthiazuron (MTT) assay, flow cytometry (FCM) was used to measure the apoptosis rate. RT-PCR was used to measure the transcription of apoptosis suppressor gene bcl-2, survivin and apoptosis promoting gene Bar. Results: Indimbin-3'-monoxime inhibited growth of HT-29 cells in a dose-dependent and time-dependent manner (F=11.25, P<0.01). The apoptosis rate increased after the treatment by indirubin-3'-monoxime at 10 μmol/L. There were significant differences between different time groups (F=195.25, P<0.01). The transcription of survivin (F=78.75, P<0.01) and Bax (F=87.61, P<0.01) mRNA in HT-29 cells were increased; the transcription of bcl-2 was significantly decreased (F=95.82, P<0.01). Conclusion: Indirubin-3'-monoxime has obviously inhibited proliferation and induce apoptosis of colon cancer HT-29 cells, its mechanism may be related to decrease the bcl-2/Bax ratio.

Objective: To investigate the effect of losartan on angiotensin II (Ang II) expression and myocardial remodeling in myocardial infarction (MI) rats’ model.
Methods: A total of 32 SD male rats were divided into 4 groups, Sham operation group, MI group, MI with losartan 10mg/(kg·d) group and MI with losartan 20mg/(kg·d). n=8 in each group. MI model was established and the electrocardiogram changes before and after MI were recorded, hemodynamic indexes were detected at 4 weeks after MI, pathological changes of myocardial tissue were examined by HE staining. The myocardial mRNA and protein expressions of ACE2 and Ang II were detected by RT-PCR and Western Blot analysis.
Results: Compared with Sham operation group, MI group showed increased LVMI and decreased LVEF P<0.05;the above changes were getting better in both MI with losartan groups in a dose-dependent manner. The pathological examination presented that MI group had myocardial cell swelling, fracture, hyperplasia and inflammatory cell infiltration, those damages were less in MI with losartan groups in a dose-dependent manner, Sham operation group had no pathological changes. Compared with Sham operation group, the mRNA and protein expressions of Ang II were obviously higher in MI group, P<0.05 and the expressions were decreased in MI with losartan groups in a dose-dependent manner;the mRNA and protein expressions of ACE2 were slightly increased in MI group and the expressions were further increased in MI with losartan groups in a dose-dependent manner.
Conclusion: Losartan could increase ACE2 expression and therefore, inhibit Ang II expression and improve the ventricular remodeling in MI rats’ model.

OBJECTIVE:To study the pharmacokinetics of the active ingredients of Shenmai injection,including ginsenoside Rg1 and ginsenoside Re,in normal Beagle dogs and those with myocardial ischemia. METHODS:6 Beagle dogs were given isopro-terenol hydrochloride (1.1 mg/kg) sc to establish the model of myocardial ischemia (model group). Another 6 Beagle dogs were given isometric normal saline (2.2 ml/kg) sc as controls group. The two groups of dogs respectively received corresponding drugs sc at 8:00 am and 13:00 pm on day 1 and at 8:00 am on day 2. Each group of dogs were given Shenmai injection(1.6 ml/kg)iv 1 h after administration on day 2,and such intravenous drip lasted for about 1 h. Blood was collected from each group 0,0.25, 0.5,0.75,1(the end of iv),1.5,2,3,4,6,8,12 and 24 h from the start of iv. Liquid chromatography-mass spectrometry was adopted to determine the concentrations of ginsenoside Rg1 and ginsenoside Re in blood,and WinNonlin 6.3 was used to calculate pharmacokinetic parameters for comparison. RESULTS:For ginsenoside Re in the dogs of the model group,t1/2 was(2.69±1.12) h,AUC0-24 h was(2 060.78±812.18)h·μg/L,Vz was(46.16±20.98)ml and CL was(9.02±4.45)ml/h;compared to the normal control group,AUC0-24 h was much greater and Vz and CL were significantly lower,showing a statistically significant difference(P<0.05). No significant difference in the pharmacokinetic parameters of ginsenoside Rg1 was shown between 2 groups(P>0.05). CON-CLUSIONS:Myocardial ischemia may affect the removal of ginsenoside Re in Beagle dogs,but has no effect on the pharmacoki-netic process of ginsenoside Rg1.

This study was aimed to compare the pharmacokinetics (PK) of Shengmai injection and Shenmai injection with a single injection administration using a constant speed in subjects with stable angina pectoris.A total of 20 subjects with stable angina pectoris were divided into two groups.Each group was administered with Shengmai and Shenmai injection.The liquid chromatography-mass spectrometry (LC/MS) was adopted to determine concentrations of ginsenosides in plasma at different time points.PK parameters were calculated for comparison.The results showed that after a single intravenous infusion of Shengmai and Shenmai injection,the Cm.of ginsenoside Rg1,ginsenoside Re,ginsenoside Rb1 and ginsenoside Rc in Shenmai group were higher than those of the Shengmai group with statistical significance (P ≤0.05).There were differences on the T1/2 of ginsenoside Rg1,AUC0-144h and CL of ginsenoside Rc,as well as Tmax of ginsenoside Rd (P ≤ 0.05).However,there was no significant difference shown on other PK parameters.It was concluded that after a single Shengmai or Shenmai injection,there were PK differences of ginsenoside Rg1,ginsenoside Re,ginsenoside Rb1 and ginsenoside Rc in the human body.The clinical medication selection should be based on syndrome differentiation and treatment of patients.

Objective: To evaluate the effects of antisense oligodeoxynucleotides (ODNs) (AS1 complementary to the translation initiation region and AS2 complementary to the coding region) targeted to bcl-2 oncogene on Bcl-2 protein expression and apoptosis of human renal cell carcinoma (RCC) cells. Methods; Expression of bcl-2 mRNA in RCC cell lines was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR). The ODNs were transfected with Lipo-fectin into RCC cell lines. The expression of Bcl-2 protein in ACHN tumor cells was examined by Western blot analysis, and the apoptosis of those cells was determined by flow cytometric analysis. Results: Expression of bcl-2 mRNA was detected in all five RCC lines. Transfected bcl-2 antisense ODNs, but not sense ODNs, inhibited Bcl-2 protein expression in ACHN cells. The AS2 antisense ODN showed a superior effect compared with AS1 ODN. The apoptosis of ACHN cell could been induced by bcl-2 antisese ODNs , and percentage of apoptotic cells was noted 32. 1% and 43. 2% treated with AS1 and AS2, respectively. Conclusions: Treatment of human RCC cells with antisense ODNs targeting bcl-2 gene inhibits expression of Bcl-2 protein and induce apoptosis.

Retroperitoneal laparoscopic live donor nephrectomy offers an intrinsic advantage over conventional transperitoneal laparoscopic nephrectomy because of the potentially lower risk for early and late donor intraperitoneal complications. Herein we presented our experience performing retroperitoneal laparoscopic live donor nephrectomy in 105 donors. All donor nephrectomy was successful. There were no donor deaths and no conversion to open surgery. Mean operation time was 112 min (range, 70-200 min). Intraoperative blood loss was 10-150 mL with an average of 30 mL. Warm ischemia time was 1.3 to 6 min with an average of 3.1 min. Postoperative retroperitoneal hematoma occurred in only one case and there were no other surgical complications. Donors were discharged from the hospital 5 to 10 days postoperation. Average postoperative hospital stay was 6.4 days. One graft was removed due to acute rejection. Delayed graft function occurred in two recipients but renal function returned to normal within four weeks. The other recipients had normal renal function in two weeks except three recipients in four weeks. We believe that retroperitoneal laparoscopic live donor nephrectomy is safe, reliable, and less invasive.