A high resolution reaction microscope with universal two-region time-focusing method

This paper presents a novel reaction microscope designed for ion-atom collision investigations, established at the Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China. Its time-of-flight (TOF) spectrometer employs an innovative flight-time focusing method consisting of two acceleration regions, providing optimal time focusing conditions for charged fragments with diverse initial velocities. The TOF spectrometer's axis intentionally tilts by 12° relative to the ion beam direction, preventing potential obstructions from the TOF grid electrodes. The introduced focusing method allows for a flexible time-focusing TOF spectrometer design without restricting the length ratio of the two regions. In addition, this configuration in our case significantly suppresses noise on the recoil ion detector produced by residual gas in the ion beam trajectory, which is a considerable challenge in longitudinal spectrometers. In a test experiment on the single electron capture reaction involving 62.5 keV/u He2+ ions and a helium atomic beam, the recoil longitudinal momentum resolution achieved 0.068 atomic units. This novel configuration and successful test run show excellent precision for ion-atom collision studies.

The effect of sodium-glucose cotransporter-2 inhibitors on cardiac structure remodeling and function: A meta-analysis of randomized controlled trials

BACKGROUND

It has been proven that sodium-glucose co-transporter 2 inhibitors (SGLT2is) improve the prognosis of patients with heart failure, independent of the presence of diabetes mellitus. Whether SGLT2 inhibitors affect cardiac structural remodeling and cardiac function is still uncertain.

METHODS

We included published randomized controlled trials (RCTs) to compare the effect of SGLT2is and control therapy in patients with or without heart failure. The meta-analysis was performed using Review Manager 5.3 software.

RESULTS

A total of 15 RCTs with a total of 1343 patients were selected for this meta-analysis, 663 of whom were on SGLT2is treatment and 680 of whom were in the control group. SGLT2is significantly improved heart rate (HR) [MD: -2.74, 95% CI (-4.71, -0.77), P = 0.006], left atrium volume index (LAVi) [MD: -1.99, 95% CI (-3.23,-0.75), P = 0.002], E/e' [MD: -1.47, 95% CI (-1.83,-1.10), P<0.00001], left ventricular mass index (LVMi) [MD: -2.38, 95% CI (-4.35, -0.40), P = 0.02], left ventricular end-systolic volume (LVESV) [MD: -6.50, 95% CI (-11.15,-1.84), P = 0.006], and left ventricular ejection fraction (LVEF) [MD: 1.78, 95% CI (0.56,3.01), P = 0.004] in the total population. Subgroup analysis indicated that compared with other SGLT2is, empagliflozin significantly decreased LVEDV, LVESV,LVMi, LAVi, E/e', and increased LVEF (P<0.05). In addition, the cardiac anti-remodeling effects of SGLT2 are particularly significant in patients with heart failure.

CONCLUSION

Our study showed that SGLT2is, particularly empagliflozin, significantly reverse cardiac remodeling in patients with heart failure. Empagliflozin may be a potentially promising agent to reverse cardiac remodeling in clinical practice.

Safety and efficacy of intracoronary recombinant human prourokinase administration in patients with acute myocardial infarction and ST‑segment elevation: A meta‑analysis of randomized controlled trials

Slow blood flow or no reflow following percutaneous coronary intervention (PCI) in patients with acute ST-segment elevation myocardial infarction (STEMI) typically leads to an adverse prognosis. However, it is controversial whether to use prourokinase (Pro-UK) during PCI in patients with acute STEMI. The present meta-analysis compared the efficacy and safety of intracoronary Pro-UK administration in patients with acute STEMI. Published randomized controlled trials (RCTs) were analyzed to compare Pro-UK with non-Pro-UK treatment in patients with acute STEMI. PubMed, Cochrane Library and China National Knowledge Infrastructure were searched and meta-analysis was performed using Review Manager 5.3 software. A total of 13 RCTs were selected and 1,797 patients were considered in the meta-analysis, including 897 patients who received Pro-UK intervention and 900 patients who were in the control group. No significant heterogeneity was identified across these selected studies. Pro-UK therapy significantly decreased the incidence of major adverse cardiac events [risk ratio (RR), 0.68; 95% CI, 0.56-0.82, P<0.0001], left ventricular end-diastolic diameter [standardized mean difference (SMD), -0.26; 95% CI, -0.40 - -0.12; P=0.0003], corrected thrombolysis in myocardial infarction (TIMI) frame count [SMD, -0.45; 95% CI, -0.62 - -0.28; P<0.00001] and cardiac troponin I [SMD, -0.31; 95% CI, -0.46 - -0.17; P<0.0001]. In addition, Pro-UK administration increased TIMI grade 3 flow (RR, 1.16; 95% CI, 1.07-1.25; P=0.0003), TIMI myocardial perfusion grade 3 (RR: 1.39, 95% CI: 1.12-1.74, P=0.004), ST-segment resolution (RR, 1.23; 95% CI, 1.10-1.36; P=0.0002) and left ventricular ejection fraction (SMD, 0.38; 95% CI, 0.27-0.49; P<0.00001). No significant difference was identified in bleeding (RR, 1.12; 95% CI, 0.85-1.47; P=0.41). The present meta-analysis determined that intracoronary Pro-UK administration is efficacious and safe to decrease slow blood flow or no reflow phenomena following PCI and improve the prognosis of patients with acute STEMI.

[Establishment of human colon cancer transplantation tumor model in normal immune mice]

Objective: Establishment of a new model of human primary colon cancer transplantation tumor in normal immune mice and to provide a reliable experimental animal model for studying the pathogenesis of colon cancer under normal immunity. Methods: Human colon cancer cells come from colon cancer patients who underwent surgery in the Affiliated Hospital of Jining Medical College in 2017. The mice in the cell control group were inoculated with phosphate buffered solution (PBS) containing colon cancer cells, the microcarrier control group was inoculated with PBS containing microcarrier 6, and the cell-microcarrier complex group was inoculated with the PBS containing colon cancer cell-microcarrier complex. The cells of each group were inoculated under the skin of the right axilla of mice by subcutaneous injection, and the time, size, tumor formation rate and pathological changes under microscope were recorded. The transplanted tumor tissue was immunohistochemically stained with the EnVisiion two-step method, and the tumor formation rate of the transplanted tumor was judged according to the proportion of positive cells in the visual field. The polymerase chain reaction (PCR) method was used to detect the expression of human-specific Alu sequence in mice tumor tissue. Results: After inoculation with tumor cells, the mice in the cell control group and the microcarrier control group did not die and did not form tumors; the mice in the cell-microcarrier complex group had palpable subcutaneous tumors in the right axillary subcutaneously on the 5th to 7th days after inoculation, and tumor formation rate is 67% (10/15), and the tumor volume can reach about 500 mm(3) 2 to 3 weeks after vaccination. The immunohistochemistry results showed that CK20, CDX-2 and carcinoembryonic antigen were all positively expressed. The PCR results showed that the expression of human-specific Alu sequence can be detected in the transplanted tumor tissue of tumor-bearing mice. Conclusion: Human primary colon cancer cells used microcarrier 6 as a carrier to form tumors in normal immunized mice, and successfully established a new model of human colon cancer transplantation tumor in normal immune mice.

[Role of cytokine-matrix metalloproteinase axis on promoting vascular neointima hyperplasia in mice]

Objective: To observe the effects of tumor necrosis factor-α (TNF-α) and platelet derived growth factor (PDGF) on vascular neointimal hyperplasia on matrix metalloproteinase 9/2 gene knockout (MMP9/2^-/-) mice and explore related mechanisms. Methods: Mice of control group, MMP9^-/- group, MMP2^-/- group and MMP9/2^-/- group were studied. Femoral artery was injured by transluminal wire, the mRNA expression levels of TNF-α and PDGF on femoral artery were detected by RT-PCR; the protein expression of MMP9 and MMP2 were assessed by Western blot on day 0, 1, 3, 7, 14 and 28 post injury. Mice in control group received TNF-α(5 ng/ml, 0.10 ml), TNF-α(0.05 ml)+ MMP inhibitor SB-3CT(0.50 ng/ml, 0.05 ml) injection, or PDGF-bb (10 ng/ml, 0.10 ml)and PDGF-bb(0.05 ml)+ SB-3CT(0.05 ml)injection around injured artery, intimal hyperplasia at 2 and 4 weeks after injury was observed. Intimal hyperplasia at 2 and 4 weeks after injury was also observed in MMP9/2^-/- mice. TNF-α(5 ng/ml, 0.10 ml)was injected to MMP2^-/- mice, PDGF-bb (0.1 ml) was injected to MMP9^-/- mice around injured artery, intimal hyperplasia at 2 and 4 weeks after injury was observed. The degree of neointimal hyperplasia were observed by the Elastica-van Gieson staining and the area of neointima and media of the arteries were measured by SigmaPlot and intima ratio was calculated. Vascular smooth muscle cell (VSMC) mediums of MMP9^-/- and MMP2^-/- mice were stimulated by TNF-α and PDGF-bb, respectively, and migration assay, and proliferation assay were performed, relative migration and proliferation cells numbers were counted. Results: (1) mRNA expression of TNF-α (235.33±23.68) and PDGF-bb (3.30±0.56) in femoral arteries peaked at 1 day after injury, while MMP9 or MMP2 protein expression peaked at 7 or 28 days after injury. (2)In control mice, TNF-α intervention significantly enhanced intimal hyperplasia at 2 weeks after injury (2.21±0.05 vs. 1.55±0.03 in blank control group, P<0.05), while PDGF-bb intervention significantly enhanced intimal hyperplasia at 4 weeks after injury (2.60±0.07 vs. 1.89±0.04, P=0.03). (3) Intima hyperplasia was significantly higher in control group than in MMP9/2^-/- group at 2 weeks (1.63±0.05 vs. 0.46±0.01, P=0.008) and 4 weeks (2.24±0.06 vs. 0.51±0.01) after injury(P=0.005). (4) TNF-α intervention stimulated intimal hyperplasia in MMP2^-/-mice (intimal ratio at 2 weeks after injury: 1.73±0.05 vs.1.23±0.03, P=0.02)and PDGF-bb intervention stimulated intimal hyperplasia in MMP9^-/-mice(intimal ratio at 4 weeks after injury: 2.32±0.06 vs.1.35±0.03, P=0.03). (5) Reduced VSMC migration was evidenced in MMP9^-/- mice post TNF-α stimulation (1.45±0.03 vs. 2.16±0.04 in control group, P=0.03), while reduced VSMC proliferation post PDGF was seen in MMP2^-/- group (1.15±0.02 vs.1.82±0.04 in control group, P=0.03). Conclusions: TNF-α induced MMP9 activation plays a major role on promoting VSMC migration at the first 2 weeks after vascular injury, while PDGF induced MMP2 activation plays a crucial role on VSMC proliferation on the following 2 weeks after vascular injury in this mice model. Thus, the axis of TNF-α-MMP9-VSMC migration axis and PDGF-MMP2-VSMC proliferation axis are the two major working mechanisms responsible for intimal hyperplasia post vascular injury.

Genetic diversity analysis of tree peony germplasm using iPBS markers

We examined the genetic diversity of 10 wild species (populations) and 55 varieties of tree peony using inter-primer binding site (iPBS) markers. From a total of 36 iPBS primers, 16 were selected based on polymorphic amplification. The number of bands amplified by each primer ranged from 9 to 19, with an average of 12.88 bands per primer. The length of bands ranged from 100 to 2000 bp, concentrated at 200 to 1800 bp. Sixteen primers amplified 206 bands in total, of which 173 bands were polymorphic with a polymorphism ratio of 83.98%. Each primer amplified 10.81 polymorphic bands on average. The data were then used to construct a phylogenetic tree using unweighted pair group method with arithmetic mean methods. Clustering analysis showed that the genetic relationships among the varieties were not only related to the genetic background or geographic origin, but also to the flowering phase, flower color, and flower type. Our data also indicated that iPBS markers were useful tools for classifying tree peony germplasms and for tree peony breeding, and the specific bands were helpful for molecular identification of tree peony varieties.

Genetic relationships of the Japanese persimmon Diospyros kaki (Ebenaceae) and related species revealed by SSR analysis

Simple sequence repeat (SSR) molecular markers based on 18 primers were employed to study the genetic relationship of Japanese persimmon (Diospyros kaki) specimens. Two hundred and sixty-two bands were detected in 30 Japanese persimmon samples, including 14 Japanese and 10 Chinese genotypes of Japanese persimmon (Diospyros kaki) and six related species, D. lotus, D. glaucifolia, D. oleifera, D. rhombifolia, D. virginiana, and Jinzaoshi (unclassified - previously indicated to be D. kaki). All SSR primers developed from D. kaki were successfully employed to reveal the polymorphism in other species of Diospyros. Most of the primers were highly polymorphic, with a degree of polymorphism equal to or higher than 0.66. The results from the neighbor-joining dendrogram and the principal coordinate analysis diagram were the same; i.e., the Chinese and Japanese genotypes and related species were separated and the relationships revealed were consistent with the known pedigrees. We also concluded that 'Xiangxitianshi' from Xiangxi municipality, Hunan Province, China, is actually a sport or somaclonal variant of 'Maekawa-Jirou', and that 'Jinzaoshi' should be classified as a distinct species of Diospyros. We found that SSR markers are a valuable tool for the estimation of genetic diversity and divergence in Diospyros.

[Anatomical study and clinical applications of flaps based on cutaneous branches arising from posterior tibial vessels]

OBJECTIVE

To provide an anatomical basis for the clinical applications of the medial fascinocutaneous flap of calf and to verify its clinical value.

METHODS

In 20 lower limb specimens of adult human cadavers, the number, course, size, position and distribution of septocutaneous branches of the posterior tibial vessels are marked by means of red latex and black ink irrigations through femur artery and septocutaneous branches of the posterior tibial artery respectively.

RESULTS

The posterior tibial artery gives off several septocutaneous branches at the upper, middle and lower one-third of the leg respectively. Each septocutaneous artery has one or sometimes two concomitant veins. Based on this result, anterograde or reverse pedicled fasciocutaneous flap can be performed for the purpose of repairing soft tissue defects of leg and foot. The flap was clinically applied to treat leg and foot soft tissue defects in 12 cases with satisfactory results.

CONCLUSION

The flap is easy to dissect, the posterior tibial artery can be preserved with high successful rate. Therefore, it offers an useful alternative in the repairing and reconstruction of nonextensive soft tissue defects in the leg and foot.

Inhibitory effects of dauricine on potassium currents in guinea pig ventricular myocytes

AIM

To study the effects of dauricine(Dau) on the rapidly activating component (IKr), the slowly activating component (IKs) of the delayed rectifier potassium current, and the inward rectifier potassium current (IKl) in guinea pig ventricular myocytes.

METHODS

Single myocytes were dissociated by enzymatic dissociation method. The currents were recorded with the whole-cell configuration of the patch-clamp technique.

RESULTS

(1) Dau 1, 3, 10, 30, and 100 mumol.L-1 blocked IKr and tail current (IKr-tail) in a concentration-dependent manner. The IC50 for block of IKr-tail was 16 (95% confidence limits: 13-22) mumol.L-1. The time constant of IKr-tail deactivation was (140 +/- 38) ms in the control and (130 +/- 26) ms in the presence of Dau 30 mumol.L-1 (n = 6 cells from 3 animals, P > 0.05). (2) Dau 1-100 mumol.L-1 produced concentration-dependent blocks of IKs and tail current (IKs-tail). The IC50 value for block of IKs-tail was 33 (95% confidence limits: 24-46) mumol.L-1. The time constant of IKs-tail deactivation was (92 +/- 18) ms in the control and (84 +/- 16) ms in the presence of Dau 30 mumol.L-1 (n = 8 cells from 4 animals, P > 0.05). (3) Addition of Dau 30 mumol.L-1 induced block of IKs and IKs-tail (n = 7 cells from 3 animals). The degree of block of IKs and IKs-tail depended on test potentials, increasing with more positive depolarizations. (4) Dau 20 mumol.L-1 blocked mainly inward component of IKl and reduced the reversal potential from -72 mV (control) to -78 mV (n = 6 cells from 3 animals).

CONCLUSION

(1) Dau inhibited IKs, but not the process of IKs deactivation. (2) Dau blocked IKr, but not the process of deactivation. (3) Dau had a blocking effect on IKl.

Dauricine inhibited L-type calcium current in single cardiomyocyte of guinea pig

AIM

To study the effect of dauricine (Dau) on L-type calcium current in guinea pig ventricular myocytes.

METHODS

Using whole-cell recording method to record L-type calcium current (ICa) in single ventricular cell of guinea pig.

RESULTS

Dau 1, 10, and 100 mumol.L-1 markedly reduced ICa by 15.2% +/- 2.2%, 41% +/- 5%, and 82% +/- 8%, respectively. After washing out, ICa partially recovered. Dau inhibited ICa at 3 Hz and 1 Hz to a similar extent, its effect on ICa appeared to be not frequency-dependent.

CONCLUSION

Dau had a calcium channel blocking effect.

Effects of dauricine, quinidine, and sotalol on action potential duration of papillary muscles in vitro

AIM

To compare the characteristics of dauricine, sotalol, and quinidine on action potential duration (APD).

METHODS

Using intracellular microelectrode method to record APD in guinea pig papillary muscles.

RESULTS

Dauricine 20 mumol.L-1 prolonged action potential at 90% repolarization, the percent of APD prolongation were 22 +/- 8, 11 +/- 6, 9 +/- 5, 7 +/- 5, 6 +/- 3, 4.3 +/- 2.8, 4.5 +/- 2.8 at the cycle lengths of 200-2000 ms, dauricine became more effective in lengthening APD at short cycle lengths. The effect of dauricine on prolonging APD exhibited normal use-dependence, whereas quinidine 1 mumol.L-1 and sotalol 10 mumol.L-1 were less effective in lengthening APD at short cycle lengths. The effect of quinidine and sotalol on APD exhibited reverse use-dependence.

CONCLUSION

[corrected] The effect of dauricine on APD depends on activation frequency.