Single-site laparoscopic percutaneous extraperitoneal closure (SLPEC) of hernia sac high ligation using an ordinary taper needle: a novel technique for pediatric inguinal hernia

PURPOSE

Laparoscopic high ligation of the internal inguinal ring is an alternative procedure for treatment of pediatric inguinal hernia (PIH), with a major trend toward increasing use of extracorporeal knotting and decreasing use of working ports. We have utilized this laparoscopic technique to treat the entire spectrum of PIH (including incarcerated cases) for more than 17 years, and the technique continues to evolve and improve. We herein report our latest modification of this minimally invasive technique, namely single-site laparoscopic percutaneous extraperitoneal closure (SLPEC) of hernia sac high ligation using an ordinary taper needle, and evaluate its safety and efficacy.

METHODS

From July 2016 to July 2019, 790 children with indirect PIH were treated by laparoscopic surgery. All patients underwent high ligation surgery with a modified single-site laparoscopic technique mainly performed by extracorporeal suturing with an ordinary closed-eye taper needle (1/2 arc 11 × 34). The clinical data were retrospectively analyzed.

RESULTS

All surgeries were successful without serious complications. A contralateral patent processus vaginalis (CPPV) was found intraoperatively and subsequently repaired in 190 patients (25.4%). The mean operative time was 15 min (8-25 min) for 557 unilateral hernias and 21 min (14-36 min) for 233 bilateral hernias. The mean postoperative stay was 20 h. Minor complications occurred in five patients (0.63%) and were managed properly, with no major impact on the final outcomes. No recurrence was noted in the patients who were followed up for 6-42 months. No obvious scar was present postoperatively.

CONCLUSION

Modified SLPEC of hernia sac high ligation using an ordinary taper needle for repair of indirect PIH is a safe, reliable, and minimally invasive procedure with satisfactory outcome, with no special device being needed. It is easy to learn and perform and is worthy of popularization in the clinical setting.

New insights on the energy transfer mechanisms of Eu-doped CdS quantum dots

Eu-doped CdS quantum dots with the Eu dopant concentration in the range of 0.5–10% and zinc blende structure were successfully synthesized by a wet chemical method in the noncoordinating solvent.

MiR-128 promotes the apoptosis of glioma cells via binding to NEK2

OBJECTIVE

The aim of this study was to explore whether miR-128 could promote the apoptosis of glioma cells by targeting NIMA related kinase-2 (NEK2), thus participating in the occurrence and progression of glioma.

PATIENTS AND METHODS

Expression levels of miR-128 and NEK2 in glioma tissues and normal brain tissues were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The relationship between miR-128 expression, tumor size and stage of glioma was analyzed. The effect of miR-128 on the apoptosis of glioma cells was detected by flow cytometry and Western blot, respectively. Dual-luciferase reporter gene assay was applied to verify the binding condition of miR-128 and NEK2. Meanwhile, rescue experiments were conducted to determine whether miR-128 could promote the apoptosis of glioma cells by targeting NEK2.

RESULTS

The expression level of miR-128 in glioma tissues was significantly lower than that of normal brain tissues. However, NEK2 was highly expressed in glioma tissues. MiR-128 expression was correlated to tumor size and malignant level of glioma, whereas not related to age and gender of glioma patients. Meanwhile, overexpression of miR-128 promoted the apoptosis of U87 cells, upregulated protein levels of cleaved Caspase-3 and BCL2-associated X (Bax), and downregulated B-cell lymphoma-2 (Bcl-2). Dual-luciferase reporter gene assay indicated that miR-128 directly bound to NEK2. Further rescue experiments suggested that NEK2 overexpression partially reversed the effect of miR-128 on the apoptosis of glioma cells.

CONCLUSIONS

Downregulated miR-128 inhibited the apoptosis of glioma cells via targeting NEK2.

Effect of bronchial artery embolisation on the management of tuberculosis-related haemoptysis

OBJECTIVE: To identify risk factors influencing outcomes of bronchial arterial embolisation (BAE) in tuberculosis (TB) related haemoptysis.METHODS: A cohort of 207 patients underwent BAE for TB-related haemoptysis between March 2014 and March 2018. The clinical data were reviewed. Follow-up ranged from 24 to 1749 days.RESULTS: Immediate haemostasis rate was 94.2%; aggressive pleural thickening (PT) was found to be a risk factor for haemoptysis (P = 0.000, OR 22.52). Cumulative recurrence-free rates were respectively 98.5%, 94.8%, 88.7%, 79.9%, 68.5%, 65.7% and 62.7% for 1, 3, 6, 12, 24, 36 and 48 months. Respectively 8 and 15 patients recovered from pneumonectomy and re-BAE. However, five patients required a third BAE. The Cox regression analysis indicated that aggressive PT (P = 0.000), diabetes mellitus (DM) (P = 0.018) and pulmonary fungal infection (PFI) (P = 0.001) were independent risk factors for recurrence. The death rate following BAE was 9.2%; aggressive PT was a risk factor (P = 0.000, OR 8.14).CONCLUSION: BAE is effective for TB-related haemoptysis in most cases. Aggressive PT, DM and PFI are independent risk factors influencing the prognosis following BAE. PFI and DM should be well managed, while proper surgery should be considered for aggressive PT.

Prevalence and incidence of systemic lupus erythematosus and associated outcomes in the 2009-2016 US Medicare population

OBJECTIVES

We aimed to update data on the prevalence and incidence of systemic lupus erythematosus (SLE) in the Medicare population and describe associated outcomes.

METHODS

This observational study used Medicare 20% random sample data 2007-2016 to estimate SLE prevalence and incidence 2009-2016. The study population included patients aged ≥18 years (stratified by <65 and ≥65 years) with Medicare fee-for-service coverage. The SLE definition was based on a published and validated algorithm. All-cause death, hospitalizations, and kidney disease incidence were defined for a prevalent SLE cohort 2011-2015. Unadjusted event rates during 5-year follow-up were reported per 100 patient-years.

RESULTS

The study included > 5 million eligible patients for each year 2009-2016. There were 19,518 (10,898, aged ≥65; 8620, aged <65) in 2016, extrapolated to 97,590 (54,490 aged ≥65; 43,100 aged <65) in the overall 2016 Medicare population. Age- and sex-adjusted prevalence rates (per 100,000 Medicare population) ranged from 301.1 in 2009 to 366.6 in 2016, all ages, and 184.0-239.9, ≥65 years. There were 2614 (1844 aged ≥65; 770 aged <65) incident patients in 2016; age-/sex-adjusted incidence rates (per 100,000 Medicare population) ranged from 46.9 in 2009 to 49.0 in 2016, all ages, and 37.5-40.8, ≥65. Five-year unadjusted mortality, elderly vs. younger, was 8.8 vs. 3.8, morbidity 34.5 vs. 32.4, and kidney disease incidence 19.8 vs. 18.0 per 100 patient-years.

CONCLUSIONS

Prevalence rates steadily increased while incidence was relatively stable 2009-2016. Our data should be interpreted with caution due to our elderly study population.

Dandelion-Like Tailorable Nanoparticles for Tumor Microenvironment Modulation

Tumor-associated macrophages (TAMs) constitute over 50% of the number of cells within the tumor, playing a major role in tumor progression and invasion. Remodeling the tumor immune microenvironment by modulating TAM polarization has been emerging as a new and promising therapeutic strategy. However, the high interstitial fluid pressure and dense extracellular matrix lead to insufficient penetration of nanosized therapies. To overcome this dilemma, an acid-triggered size-changeable nanoparticle (aptamer/acid sensitive linker crosslinked DGL/zoledronic acid, i.e., Apt@(DGL-ZA) n NPs) with effective tumor distribution, extravasation, and penetration is designed. Dendrigraft poly-L-lysines (DGLs) which can induce tumor autophagy as mimics of natural abnormal proteins are crosslinked via a mild-acid-responsive linker (1,6-bis(4-formylbenzoyloxy) hexane). Long circulation property and tumor penetration are achieved simultaneously by catching DGLs in neutral pH while releasing them in the tumor's pH, like dandelion seeds in midair. The macrophage conditioning agent zoledronic acid (ZA) is loaded on DGLs by the charge attraction. A Tenascin-C targeting aptamer (GBI-10) is modified onto (DGL-ZA) n NPs for a tumor-homing effect. Apt@(DGL-ZA) n NPs show both enhanced penetration in in vitro 3D triple negative breast cancer spheroids and in vivo tumor tissues. Effective macrophage regulation, enhanced tumor autophagy, and excellent in vivo antitumor efficacy are achieved, suggesting this tactic as a significant antitumor strategy.

Clinical outcomes and predictive relapse factors of IgG4-related disease following treatment: a long-term cohort study

OBJECTIVES

The aim of this study was to investigate the predictive factors for relapse of IgG4-related disease (IgG4-RD) and observe the long-term clinical outcomes in patients with IgG4-RD.

METHODS

We included in the present analysis 122 patients who were newly diagnosed with IgG4-RD, treated with glucocorticoid (GC) monotherapy or GC and immunosuppressant combination therapy, and followed for at least 3 years. Clinical relapse, response and side effects were recorded.

RESULTS

The cumulative relapse rates of patients in this study were 10.66%, 22.95% and 27.87% at 12, 24 and 36 months, respectively. Complete drug withdrawal was an independent risk factor for disease relapse. Higher serum IgG4 concentrations, involvement of more organs, higher IgG4 RI scores and elevation of eosinophils at baseline were closely associated with disease relapse. Re-elevation of serum IgG4 concentrations and low GC maintenance dosage during the follow-up period were significantly associated with clinical relapse. The GC dosage should be more than 6.25 mg day^-1 as monotherapy during the maintenance stage; moreover, combining with immunosuppressants can reduce the GC dosage. Adding GC or immunosuppressants for patients with re-elevation of serum IgG4 levels could prevent later disease relapse. No serious complications were noted during long-term follow-up.

CONCLUSIONS

The combination of GC with immunosuppressants was more effective than GC monotherapy during the steroid tapering and maintenance stages. Higher serum IgG4 levels, involvement of more organs, higher IgG4 RI scores, history of allergy, eosinophil elevation at baseline, re-elevation of serum IgG4 levels and lower GC maintenance dosage at follow-up might be predictive of relapse.

Smart identification of psoriasis by images using convolutional neural networks: a case study in China

BACKGROUND

Psoriasis is a chronic inflammatory skin disease, which holds a high incidence in China. However, professional dermatologists who can diagnose psoriasis early and correctly are insufficient in China, especially in the rural areas. A smart approach to identify psoriasis by pictures would be highly adaptable countrywide and could play a useful role in early diagnosis and regular treatment of psoriasis.

OBJECTIVES

Design and evaluation of a smart psoriasis identification system based on clinical images (without relying on a dermatoscope) that works effectively similar to a dermatologist.

METHODS

A set of deep learning models using convolutional neural networks (CNNs) was explored and compared in the system for automatic identification of psoriasis. The work was carried out on a standardized dermatological dataset with 8021 clinical images of 9 common disorders including psoriasis along with full electronic medical records of patients built over the last 9 years in China. A two-stage deep neural network was designed and developed to identify psoriasis. In the first stage, a multilabel classifier was trained to learn the visual patterns for each individual skin disease. In the second stage, the output of the first stage was utilized to distinguish psoriasis from other skin diseases.

RESULTS

The area under the curve (AUC) of the two-stage model reached 0.981 ± 0.015, which outperforms a single-stage model. And, the classifier showed superior performance (missed diagnosis rate: 0.03, misdiagnosis rate: 0.04) than 25 Chinese dermatologists (missed diagnosis rate: 0.19, misdiagnosis rate: 0.10) in the diagnosis of psoriasis on 100 clinical images.

CONCLUSIONS

Using clinical images to identify psoriasis is feasible and effective based on CNNs, which also builds a solid technical base for smart care of skin diseases especially psoriasis using mobile/tablet applications for teledermatology in China.

Body mass index cut-off points for predicting chronic non-communicable disease should differ by gender and age group

OBJECTIVES

The objective of this study to determine whether body mass index (BMI) in different genders and age groups need different thresholds when predicting chronic non-communicable diseases (CNCDs).

STUDY DESIGN

This is a cross-sectional study.

METHODS

Data were obtained from the China Health and Nutrition Survey conducted in 2009. Sequential sample cluster analysis was used to group age according to BMI. Propensity score matching was used to eliminate the influence of age. Receiver operating characteristic curve based on gender and age group was used to evaluate the cut-off values and efficiency of BMI in each group.

RESULTS

A total of 8469 individuals were enrolled in this study. Results of sequential sample cluster analyses showed age was divided into three groups: 18-39, 40-59 and 60-99 years. There were significant differences in the distribution of BMI among the three groups for both males and females (P < 0.001). Statistical differences were observed in the distribution of BMI between genders in the 18-39- and 60-99-year-old age groups (P < 0.001). For men, the cut-off values of BMI were ≥25 kg/m², ≥24 kg/m² and ≥23 kg/m² in the 18-39, 40-59 and 60-99 years old groups, respectively; for women, the corresponding cut-off points were ≥25 kg/m², ≥23 kg/m² and ≥25 kg/m² in groups.

CONCLUSIONS

The thresholds for BMI might be different between gender and age group. In addition, it might not be suitable to determine cut-off values of BMI to predict CNCDs for people aged ≥60 years.

Vascular endothelial growth factor A/Vascular endothelial growth factor receptor 2 axis promotes human dental pulp stem cell migration via the FAK/PI3K/Akt and p38 MAPK signalling pathways

AIM

To investigate the effects of vascular endothelial growth factor A (VEGFA) and the underlying molecular mechanisms on the migration of human dental pulp stem cells (hDPSCs).

METHODOLOGY

The expression of VEGFA in inflammatory pulp tissue and lipopolysaccharide (LPS)-stimulated dental pulp cells was examined by immunofluorescence staining and qRT-PCR. The migration of hDPSCs was detected using transwell migration and wound healing assays. The activation of FAK, PI3K, Akt and p38 signalling was evaluated by Western blot analysis. Silence RNA (siRNA) technology was utilized to knockdown the expression of VEGFR1 (Flt-1) and VEGFR2 (Flk-1/KDR). PF573228 (inhibitor of FAK), LY294002 (inhibitor of PI3K), SB203580 (inhibitor of p38) and SU5416 (inhibitor of VEGFR2) were employed to investigate the effect of VEGFA on the migratory mechanism of hDPSCs. Data were analysed statistically using the Student's t-test or one-way ANOVA.

RESULTS

The expression levels of VEGFA in inflammatory pulp tissue in vivo and LPS-stimulated dental pulp cells in vitro were significantly greater than those in the control groups (P < 0.05). Vascular endothelial growth factor A promoted the migration of hDPSCs in a concentration-dependent manner. Several signalling pathways, including FAK, PI3K, Akt and p38, were activated by VEGFA in a dose- and time-dependent manner in hDPSCs. The VEGFA-induced migration of hDPSCs was significantly inhibited with drug inhibitors such as PF573228, LY294002, SB203580 or SU5416 (P < 0.05). These signalling pathways activated by VEGFA stimulation were significantly suppressed by pre-treatment with inhibitor of VEGFR2 (SU5416) or transfection with siRNA of VRGFR2 (P < 0.05) but not VEGFR1 siRNA.

CONCLUSIONS

Vascular endothelial growth factor A/VEGFR2 axis promoted the migration of hDPSCs via the FAK/PI3K/Akt and p38 MAPK signalling pathways. These findings reveal a novel molecular mechanism for cell migration of hDPSCs, which may contribute to the remodelling of pulp tissue and dentine.

Lipopolysaccharide-induced DNA damage response activates nuclear factor κB signalling pathway via GATA4 in dental pulp cells

AIM

To investigate the role of GATA-binding protein 4 (GATA4) in the inflammatory response induced by DNA double-strand breaks (DSBs) in human dental pulp cells (hDPCs).

METHODOLOGY

Lipopolysaccharide (LPS) was used for stimulating inflammation in dental pulp tissue in vivo and hDPCs in vitro. Expression levels of GATA4 and γ-H2A.X (a marker for DSBs) were detected at different stages of pulpitis in a rat model and human pulp tissues by immunohistochemistry. Real-time quantitative polymerase chain reaction and Western blot were performed to assess expression of GATA4 and γ-H2A.X and the activation of nuclear factor κB (NF-κB) in hDPCs stimulated by LPS. The comet assay was used for detecting the extent of DSBs in hDPCs. Immunocytochemistry and Western blot were utilized to evaluate expression of γ-H2A.X and GATA4 and activation of NF-κB in hDPCs pre-treated with inhibitors of DNA damage response or transfected with GATA4 small interfering RNA before the treatment of LPS. Data were analysed statistically using one-way anova or Kruskal-Wallis tests.

RESULTS

The expression of GATA4 and activation of DNA damage response and NF-κB in inflamed pulp tissue and LPS-treated hDPCs were identified. Significantly decreased expression of GATA4 and significantly decreased inflammatory processes in hDPCs were demonstrated via suppression of DNA damage response (P < 0.05). In GATA4-knockdown cells, the expression of γ-H2A.X did not change, but nuclear translocation of p65 was significantly suppressed (P < 0.05) upon induction by LPS.

CONCLUSIONS

Lipopolysaccharide-induced DSBs activated the NF-κB signalling pathway in hDPCs, and GATA4 acts as a positive moderator of the progress. The involvement of GATA4 in this pathology may serve as a therapeutic target in pulpitis.

InAs/GaAs quantum dot semiconductor saturable absorber for controllable dual-wavelength passively Q-switched fiber laser

We experimentally demonstrate the first use of 1550-nm InAs/GaAs quantum dot semiconductor saturable absorber mirror (QD-SESAM) in the dual-wavelength passively Q-switched (QS) erbium doped fiber (EDF) laser. The dual-wavelength QS lasing was obtained at a pump threshold of 180 mW with the average output power of 2.2 mW and the spacing between the two lasing wavelengths is 14 nm. A large absorption ranging from 1520 to 1590 nm has been realized when no substrate rotation was employed during the molecular beam epitaxy growth of the QD-SESAM indicating the potential to generate a 60 nm spacing of the dual-wavelength QS lasing peaks by changing the positions in the QD-SESAM and replacing EDF by co-doped fiber as gain medium. These results have provided a new opportunity towards achieving the stable and wide wavelength-tunable dual-modes fiber lasers.

Li(Cd,Mn)P: a new cadmium based diluted ferromagnetic semiconductor with independent spin & charge doping

We report a new diluted ferromagnetic semiconductor Li_1+y(Cd,Mn)P, wherein carrier is doped via excess Li while spin is doped by isovalence substitution of Mn²⁺ into Cd²⁺. The extended Cd 4d-orbitals lead to more itinerant characters of Li_1+y(Cd,Mn)P than that of analogous Li_1+y(Zn,Mn)P. A higher Curie temperature of 45 K than that for Li_1+y(Zn,Mn)P is obtained in Li_1+y(Cd,Mn)P polycrystalline samples by Arrott plot technique. The p-type carriers are determined by Hall effect measurements. The first principle calculations and X-ray diffraction measurements indicate that occupation of excess Li is at Cd sites rather than the interstitial site. Consequently holes are doped by excess Li substitution. More interestingly Li_1+y(Cd,Mn)P shows a very low coercive field (<100 Oe) and giant negative magnetoresistance (~80%) in ferromagnetic state that will benefit potential spintronics applications.

[Effects of allogeneic skin fibroblasts on promoting wound healing of diabetic mice and the mechanism]

Objective: To explore effects of allogeneic skin fibroblast (Fb) on promoting wound healing of diabetic mice and the mechanism. Methods: (1) Experiment 1. Ten diabetic mice and ten normal mice were chosen and sacrificed to collect back skin tissue. Suspension of the fourth generation of normal skin Fb and diabetic skin Fb were made. Another 27 diabetic mice were collected and divided into phosphate buffered saline (PBS) group, normal skin Fb group, and diabetic skin Fb group with random number table, with 9 mice in each group. Full-thickness skin defect wounds with area of 1 cm×1 cm were made on back of each mouse. Immediately after injury, 4 corners of wound of mice in normal skin Fb group and diabetic skin Fb group were injected with normal skin Fb and diabetic skin Fb suspension of 200 μL, respectively. Mice in PBS group were injected with the same amount of PBS at the same position. On post injury day (PID) 3, 7, 10, 14, and 17, surviving mice in the three groups were collected for gross wound observation and wound healing rate was calculated. On PID 7 and 14, 3 mice in each group were taken after gross wound observation to collect wound skin tissue. Percentage of Ki67 positive cell in wound tissue was detected by immunofluorescence method. Microvessel density (MVD) of wound tissue was detected by immunohistochemistry. Collagen fiber deposition of wound tissue was detected by Masson staining. (2) Experiment 2. Ten diabetic mice and ten normal mice were collected to make primary and the fourth generation normal skin Fb, and primary and the fourth generation diabetic skin Fb with the same method as in experiment 1. Apoptosis rate of Fb was detected by flow cytometry. The mRNA expressions and protein expressions of transforming growth factor β(1) (TGF-β(1)), advanced glycation end products (AGE), matrix metalloproteinase 9 (MMP-9), and neurokinin 1 (NK-1) of Fb were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction and Western blotting, respectively. Data were processed with analysis of variance of factorial design, one-way analysis of variance, and LSD-t test. Results: (1) The drying and scab growing speeds of wounds of mice in normal skin Fb group and diabetic skin Fb group at each time point post injury were faster than those of mice in PBS group. On PID 17, wound healing rate of mice in normal skin Fb group was close to that of mice in PBS group (t=3.45, P>0.05). At other time points, wound healing rate of mice in normal skin Fb group and diabetic skin Fb group was significantly higher than that of mice in PBS group, respectively (t=9.15, 10.25, 35.28, 6.79, 8.37, 10.69, 22.53, 6.70, 4.47, P<0.05 or P<0.01). On PID 7 and 14, wound healing rate of mice in normal skin Fb group was significantly higher than that of mice in diabetic skin Fb group (t=4.41, 4.16, P<0.05). On PID 7 and 14, percentages of Ki67 positive cells in wound tissue of mice in normal skin Fb group and diabetic skin Fb group were significantly higher than that of mice in PBS group (t=20.89, 31.82, 4.86, 29.53, P<0.05 or P<0.01); percentages of Ki67 positive cells in wound tissue of mice in normal skin Fb group were significantly higher than those of mice in diabetic skin Fb group (t=8.78, 13.51, P<0.05 or P<0.01). On PID 7 and 14, MVD of wound tissue of mice in normal skin Fb group and diabetic skin Fb group was significantly higher than that of mice in PBS group (t=26.92, 56.42, 10.36, 26.85, P<0.01). On PID 14, MVD of wound tissue of mice in normal skin Fb group was significantly higher than that of mice in diabetic skin Fb group (t=8.61, P<0.01). On PID 7 and 14, the amount of collagen fiber deposition of wound tissue of mice in normal skin Fb group was significantly higher than that of mice in diabetic skin Fb group and PBS group, respectively (t=10.09, 5.48, 4.77, 3.14, P<0.05 or P<0.01). (2) Apoptosis rate of primary normal skin Fb was (5.61±0.18)%, which was close to that of normal skin Fb of the fourth generation [(6.48±0.16)%, t=1.44, P=0.06]. Apoptosis rate of primary diabetic skin Fb was (26.25±0.56)%, which was significantly higher than that of primary normal skin Fb (t=36.61, P<0.01) and close to that of diabetic skin Fb of the fourth generation [(25.68±0.93)%, t=0.91, P=0.41]. The mRNA expressions of TGF-β(1) and NK-1 of primary normal skin Fb were significantly higher than those of primary diabetic skin Fb (t=25.25, 273.30, P<0.01). The mRNA expressions of AGE and MMP-9 of primary normal skin Fb were significantly lower than those of primary diabetic skin Fb (t=23.01, 8.84, P<0.05 or P<0.01). The mRNA expressions of TGF-β(1), AGE, and NK-1 in primary diabetic skin Fb were significantly higher than those of diabetic skin Fb of the fourth generation (t=4.34, 22.84, 12.10, P<0.05 or P<0.01). The protein expression of TGF-β(1) and NK-1 of primary normal skin Fb were significantly higher than those of primary diabetic skin Fb (t=4.61, 8.53, P<0.05). The protein expressions of AGE and MMP-9 of primary normal skin Fb were significantly lower than those of primary diabetic skin Fb (t=10.22, 29.90, P<0.01). The protein expressions of AGE and NK-1 of primary diabetic skin Fb were significantly higher than those of diabetic skin Fb of the fourth generation (t=8.09, 4.36, P<0.05 or P<0.01). Conclusions: Allogeneic skin Fb can promote wound healing through promoting Fb proliferation, angiogenesis, collagen fiber deposition in wound of diabetic mice. When diabetic skin Fb of mice is cultured in vitro away from diabetic microenvironment, cell activity can't return to normal levels, and the effects of diabetic skin Fb on promoting wound healing is not as good as normal skin Fb.

Key factors determining variations in RNA interference efficacy mediated by different double-stranded RNA lengths in Tribolium castaneum

Double-stranded RNA (dsRNA) length may affect RNA interference (RNAi) efficacy. Herein, variation in RNAi efficacy associated with dsRNA molecular length was confirmed via comparison of knockdown results following dsRNA injection into Tribolium castaneum. Through in vitro experiments with T. castaneum midgut, dsRNA accumulation in the midgut, degradation by midgut homogenates and persistence in haemolymph after injection were tested to determine the causes of RNAi efficacy variation. The comparative efficacies of dsRNAs were 480 bp ≈ 240 bp > 120 bp > 60 bp >> 21 bp. The combined midgut dsRNA accumulation and midgut homogenate-induced degradation analyses suggested cellular uptake to be the key barrier for 21 bp dsRNA functioning, but was likely not the main determinant of the variation in longer dsRNAs' (≥60 bp) bioactivity. In vitro RNAi experiment with T. castaneum midgut showed that long dsRNAs all significantly depleted the expression of corresponding genes, suggesting little variation in intracellular RNAi machinery's affinity for different dsRNA lengths. In vivo haemolymph content dynamics of different dsRNAs following injection indicated higher persistence of longer dsRNAs. In addition, comparison of the in vivo and in vitro RNAi efficacy also indicated the importance of haemolymph degradation. Thus, the varied efficacy of long dsRNAs resulted from their degradation by nucleases, which varied with dsRNA length.

[Application of stretched exponential diffusion-weighted imaging model in quantitative diagnosis of nonalcoholic fatty liver disease: in a rabbit model]

Objective: To evaluate the feasibility of diffusion parameters obtained from mono-exponential and stretched exponential diffusion-weighted imaging models in staging of nonalcoholic fatty liver disease and compare the diagnosis ability of nonalcoholic steatohepatitis. Methods: Thirty-two 12 -week-old male New Zealand rabbits, about 2.5 kg of each, were randomly divided into five groups. To obtained different severity groups of NAFLD, a variety of diet (from standard to high-fat, high cholesterol chow) were feed for different periods before liver diffusion imaging was performed by using 3.0 T MR imaging system (Discovery 750W GE health care), the value of ADC, stretched exponential model parameters distributed diffusion coefficient (DDC) and α (water molecular diffusion heterogeneity index) were measured. Liver specimens were obtained for pathological grading (NAFLD activity scoring system). The diffusion parameters of each group of NAFLD were compared by ANOVA, LSD-t test was utilized to pairwise comparison between different grades of NAFLD. Spearman rank correlation analysis was used to evaluate the correlation between ADC, DDC, α and different severity groups of NAFLD. ROC curve was compared to evaluate the diagnostic efficiency of MR parameters for NASH. Results: α was significant different between borderline and NASH groups (0.65±0.05 vs 0.72±0.07; P<0.05); ADC and DDC showed no statistical difference between borderline and NASH groups (ADC:(1.09±0.14)×10(-3) vs (1.04±0.24)×10(-3) mm(2)/s; DDC: (0.73±0.08)×10(-3) vs (0.66±0.19)×10(-3) mm(2)/s; P>0.05); ADC and DDC were negatively correlated with NAFLD, and the correlation coefficients were -0.552, -0.596, respectively (P<0.05). α was found to be positively correlated with advancement of NAFLD, the correlation coefficient was 0.729 (P<0.05).In terms of the diagnostic efficiency of NASH, the AUC of ADC, DDC and α were 0.736, 0.784, 0.900, respectively, α was significantly greater than ADC in diagnosis of NASH (P<0.05). Conclusion: Stretched exponential model parameter α (water molecular diffusion heterogeneity index) could be utilized to identify NAFLD. α may provide more information and improve the staging of NASH compared with conventional diffusion parameters.