[Construction of cochlear progenitor cells with recombinant short-hairpin RNA lentiviral vector inhibiting the expression of the β-catenin gene]

Objective: To construct a recombinant short-hairpin RNA (shRNA) lentiviral vector targeting the β-catenin gene in cochlear precursor cells (CPCs) in mice, and to investigate its inhibitory effect. Methods: PCR was used for the multiplication of the β-catenin gene, and shRNA oligo was designed based on the β-catenin gene to construct an interference vector. Gateway Technology was used to construct shRNA lentiviral vector which carried the β-catenin gene, and then 293FT cells were transfected with the constructed lentiviral vector and helper plasmids pLV/helper-SL3, pLV/helper-SL4, and pLV/helper-SL5. The virus supernatant was collected to obtain viral particles, and then mouse CPCs were transiently infected with the recombinant lentivirus with four different concentrations (0, 5, 10, and 20 μl) . The shRNA control group was established. Quantitative real-time PCR and Western blot were used to investigate the inhibitory effect of shRNA β-catenin lentiviral vector on β-catenin. Results: The recombinant shRNA β-catenin lentiviral vector was successfully constructed, and the virus titers of shβ-catenin and shβ-catenin-control were 5.05×10(7) and 4.34×10(7), respectively. The results of in vitro experiments showed that in CPCs transfected with four different concentrations of recombinant lentivirus, the content of β-catenin protein gradually decreased with the increase in concentration, and there was a significant difference between groups (P<0.05) ; the CPCs transfected with shβ-catenin had significantly lower mRNA expression of β-catenin than those in the shβ-catenin-control group (P<0.05) . Conclusion: The constructed lentiviral vector targeting the β-catenin gene has a high infection efficiency, and the successful construction of lentiviral vectors provides a technical support for analyzing the role of β-catenin in the differentiation of CPCs into auditory hair cells.

Structural and Energetic Effects of O2'-Ribose Methylation of Protonated Purine Nucleosides

The chemical difference between DNA and RNA nucleosides is their 2'-hydrogen versus 2'-hydroxyl substituents. Modification of the ribosyl moiety at the 2'-position and 2'-O-methylation in particular, is common among natural post-transcriptional modifications of RNA. 2'-Modification may alter the electronic properties and hydrogen-bonding characteristics of the nucleoside and thus may lead to enhanced stabilization or malfunction. The structures and relative glycosidic bond stabilities of the protonated forms of the 2'-O-methylated purine nucleosides, 2'-O-methyladenosine (Adom) and 2'-O-methylguanosine (Guom), were examined using two complementary tandem mass spectrometry approaches, infrared multiple photon dissociation action spectroscopy and energy-resolved collision-induced dissociation. Theoretical calculations were also performed to predict the structures and relative stabilities of stable low-energy conformations of the protonated forms of the 2'-O-methylated purine nucleosides and their infrared spectra in the gas phase. Low-energy conformations highly parallel to those found for the protonated forms of the canonical DNA and RNA purine nucleosides are also found for the protonated 2'-O-methylated purine nucleosides. Importantly, the preferred site of protonation, nucleobase orientation, and sugar puckering are preserved among the DNA, RNA, and 2'-O-methylated variants of the protonated purine nucleosides. The 2'-substituent does however influence hydrogen-bond stabilization as the 2'-O-methyl and 2'-hydroxyl substituents enable a hydrogen-bonding interaction between the 2'- and 3'-substituents, whereas a 2'-hydrogen atom does not. Further, 2'-O-methylation reduces the number of stable low-energy hydrogen-bonded conformations possible and importantly inverts the preferred polarity of this interaction versus that of the RNA analogues. Trends in the CID_50% values extracted from survival yield analyses of the 2'-O-methylated and canonical DNA and RNA forms of the protonated purine nucleosides are employed to elucidate their relative glycosidic bond stabilities. The glycosidic bond stability of Adom is found to exceed that of its DNA and RNA analogues. The glycosidic bond stability of Guom is also found to exceed that of its DNA analogue; however, this modification weakens this bond relative to its RNA counterpart. The glycosidic bond stability of the protonated purine nucleosides appears to be correlated with the hydrogen-bond stabilization of the sugar moiety.

Structural Basis for S100B Interaction with its Target Proteins

The S100B protein is an intra- and extracellular signaling protein that plays a role in a multitude of cellular processes and abnormal S100B is associated with various neurological diseases and cancers. S100B recognizes and binds effector proteins in a calcium-dependent manner. S100B has been shown to interact with the actin capping protein CapZ, protein kinase C, Hdm2 and 4, RAGE receptor, and p⁵³, among others. These protein partners interact with a common area on the S100B protein surface, validating the method of using the consensus sequence for S100B target search. In addition, each S100B target protein distinguishes itself by additional contacts with S100B. This perspective suggests that the combination of sequence homology search and structural analysis promises to identify newer S100B-binding partners beyond the use of the consensus sequence alone as the given example in the XPB subunit of the TFIIH general transcription factor. XPB is a helicase required for both transcription and DNA repair. Inherited xpb mutations are associated with human disease Xeroderma Pigmentasum, Cockayne syndrome, and trichothiodystrophy. S100B protein is likely associated with much more biological pathways and processes. We believe that S100B will attract more and more attentions in the scientific community and S100B related studies will have important implications in human health and medicine.

Assessment of left atrial function and dyssynchrony by real time three-dimensional echocardiography predicts recurrence of paroxysmal atrial fibrillation after radiofrequency ablation

OBJECTIVE

Left atrial volume and function are associated with recurrence of paroxysmal atrial fibrillation (AF) after radiofrequency ablation. A relationship between left atrial mechanical dyssynchrony and AF recurrence is presently unclear. The aim of this study was to investigate whether left atrial volume, function, and dyssynchrony were associated with AF recurrence in patients with normal left ventricular function, and normal or mildly enlarged left atrium, if assessed by the Real-time three-dimensional echocardiography (3DE).

PATIENTS AND METHODS

We included 88 patients with AF who had their first pulmonary vein isolation. There were 67 patients without and 21 patients with AF recurrence after radiofrequency ablation. Real-time 3DE was performed in the sinus rhythm the day before radiofrequency ablation. Left atrial volumes (maximum, minimum and preA), functions (passive, active and reservoir) and dyssynchrony were calculated. The latter was quantified by the standard deviation of time to minimum systolic volume (Tmsv-SD) from the end-diastole.

RESULTS

There was no difference between left atrial volume and function in patients with or without AF recurrence. However, significant differences in left atrial Tmsv-SD were observed in patients with AF recurrence.

CONCLUSIONS

In patients with normal left ventricular function, and normal/mildly enlarged left atrium, left atrial Tmsv-SD assessment by Real-time 3DE is a useful predictor of AF recurrence after radiofrequency ablation.

[Analysis of drug sensitivity of Staphylococcus aureus in patients with chronic sinusitis]

Objective:To investigate the prevalence and drug sensitivity of nasal Staphylococcus aureus infection in patients with chronic sinusitis and healthy controls.Method:Bacterial culture and drug sensitivity test were performed in 71 patients with CRS (experimental group) and 103 healthy controls (control group). The infection rate of Staphylococcus aureus and the sensitivity of the drug were analyzed based on these results.Result:Twenty-nine Staphylococcus aureus strains were isolated from 71 cases of patients in the experimental group, and the positive rate was 40.85%; 12 Staphylococcus aureus strains were isolated from 103 cases of patients in the control group, and the positive rate was 11.65%. There was no significant difference between the experimental group and the control group in the sensitivity of the strains to aminoglycosides and glycopeptides.A total of 13 strains of methicillin resistant Staphylococcus aureus (MRSA) were detected, and there was no strains which had resistance to quinolones, aminoglycosides and vancomycin.Conclusion:The incidence of CRS may be related to the infection of Staphylococcus aureus. The use of antibiotics in the treatment of CRS should be based on the results of bacterial culture and drug sensitivity test.

Associations between air pollution, climate factors and outpatient visits for eczema in West China Hospital, Chengdu, south-western China: a time series analysis

BACKGROUND

Eczema is one of the most common inflammatory dermatoses that can be provoked as a result of external and internal factors. With dense population and rapid economic development of China, air pollution is still a serious problem and the prevalence of eczema has been elevating.

OBJECTIVE

To determine the association and lagged effects between environmental factors and the outpatient visits for eczema.

METHODS

Data of daily outpatient visits for eczema at the clinics of dermatology in West China Hospital within the last 5 years were collected. Data of environmental factors of Chengdu during the same period, including temperature, relative humidity, barometric pressure, wind speed and air pollutants concentrations like sulphur dioxide (SO₂ ), nitrogen dioxide (NO₂ ) and particular matter (PM₁₀ ), were gathered. The distributed lag nonlinear model was used to statistically examine the relationship between eczema and environmental factors and their lagged effects.

RESULTS

Correlation analysis showed that eczema outpatient visits were positively correlated with the air pollutants and were negatively correlated with relative humidity. The barometric pressure and wind speed influenced the outpatient visits in association with air pollutants.

CONCLUSION

This study provides evidence that environmental factors like relative humidity and multiple air pollutants influence the incidence and prevalence of eczema and have lagged effects.

Analysis of sensitive skin barrier function: basic indicators and sebum composition

OBJECTIVES

Sensitive skin (SS) is a condition characterised by high reactivity, low tolerance, and susceptibility to allergies of the skin. Owing to changes in the environment and marketing strategies, as well as the increasing public awareness about skin care, attention to skin condition is gradually increasing. The aim of this study is to explore the differences in the skin barrier of SS and normal skin (NS).

METHODS

A questionnaire survey was conducted and basic indicators of the skin barrier were analysed. It was found that sebum secretion in the SS group was lower than that in the NS group, suggesting that the development of SS might be associated with sebum secretion and its specific components. Next, an ultra performance liquid chromatography-quadruple time-of-flight mass spectrometer was used to identify facial sebum components in female volunteers.

RESULTS

The results showed that the sebum of female volunteers with SS had high levels of ceramides, glycerophosphoethanolamines, and diacylglycerols, and low levels of glucosylceramides, glycerophosphoserines, glycerophosphocholines, and triacylglycerols.

CONCLUSION

Analysis of lipid functions suggested that the main reason for SS development in women might be a barrier dysfunction caused by excessive apoptosis and lack of water. Therefore, anti-allergy additives in cosmetic products that could inhibit apoptosis of keratinocytes and methods to maintain the stability of water molecules in the skin should be further studied.

[Lung transplantation for connective tissue disease-associated interstitial lung disease recipient]

Objective: To investigate the timing and complications of lung transplantation for the treatment of connective tissue disease-associated interstitial lung disease (CTD-ILD). Method: The clinical data of connective tissue-associated disease lung transplantation recipients from September, 2015 to February, 2017 were collected. Results: 11 patients with CTD-ILD were evaluated by lung transplantation and were treated with lung transplantation. Including 2 cases dermatomyositis/polymyositis and interstitial lung disease (PM/DM-ILD), 4 cases rheumatoid arthritis and interstitial lung disease (RA-ILD), 4 cases of primary Sjgren's syndrome and interstitial lung disease (pSS-ILD), 1 case of systemic sclerosis and interstitial lung disease (SSc-ILD). There are 6 cases are CTD-ILD-PAH patients of all. There were 5 males and 6 females, aged 37-70 years, with an average age of (52.73±9.53) years. 7 patients received single lung transplantation, 4 patients received double lung transplantation. 3 patients died in the early postoperative period, one for pulmonary embolism, one for septic shock and heart failure, one for severe primary graft failure (PGD). The remaining patients were followed up (4-24 months) with good survival, no acute and chronic rejection and other complications were observed. The survival rate was similar to that of other disease sources. Conclusion: There is no recurrence, acute and chronic rejection and other complications were observed in CTD-ILD and/or PAH lung transplant recipients. And the survival rate was comparable to that of other disease sources.Lung transplantation is a safe and effective choice for selected CTD-ILD patients.

Genetic variants of microRNA processing genes and risk of non-syndromic orofacial clefts

OBJECTIVE

MicroRNA (miRNA) processing genes play important roles in the craniofacial development. The aim of this study was to explore the associations between single nucleotide polymorphisms (SNPs) of miRNA processing genes with the risk of non-syndromic orofacial clefts (NSOC).

METHODS

We genotyped 12 potentially functional SNPs from seven miRNA processing genes (GEMIN3, DROSHA, DGCR8, GEMIN4, PIWIL1, XPO5, and DICER) in a case-control study of 602 NSOC cases and 605 controls.

RESULTS

Two SNPs were associated with the susceptibility of CL/P: rs10719 in DROSHA led to an increased risk of cleft lip with or without palate (CL/P) (GA/AA: p = .024, OR = 1.33, 95% CI = [1.04, 1.70]; GG + GA/AA: p = .037, OR = 1.29, 95% CI = [1.02, 1.63]), while rs493760 in DROSHA (CC/TT: p = .049, OR = 0.58, 95% CI = [0.34, 0.99]) could reduce the risk of CL/P. In addition, rs10719 (A)-rs493760 (C) haplotype contributed to a decreased risk of CL/P (OR = 0.77, 95% CI = [0.63, 0.94]), whereas the rs10719 (G)-rs493760 (C) haplotype contributed to the increased risk of cleft palate only (CPO) (OR = 2.70, 95% CI = [1.15, 6.35]). However, there was no difference observed in these SNPs after the Bonferroni correction.

CONCLUSION

Taken together, our results provided the potential evidence that rs10719 and rs493760 might contribute to the risk of CL/P and suggested potential genetic basis and mechanisms of CL/P. The lack of association between these SNPs and CPO might be due to the limited sample size of CPO subgroup.

Release of the tourniquet immediately after the implantation of the components reduces the incidence of deep vein thrombosis after primary total knee arthroplasty

Objectives

The length of the tourniquet time during total knee arthroplasty (TKA) is related to the incidence of post-operative deep vein thrombosis (DVT). Our aim in this study was to investigate the effect of the early release of the tourniquet on the incidence of DVT in patients undergoing TKA.

Methods

A total of 200 patients who underwent TKA between November 2015 and November 2016 were prospectively enrolled. The tourniquet was inflated before surgery and released immediately after the introduction of the components (early release group). This group was compared with a retrospective cohort of 200 primary TKAs, in which the tourniquet was released after the dressings had been applied (late release group). The presence of a DVT was detected using bilateral lower limb ultrasonography. Peri-operative clinical and follow-up data were collected for analysis.

Results

The incidence of DVT in the early release group (9 of 196, 4.6%) was significantly lower compared with the late release group (24 of 200, 12%; odds ratio (OR) 0.35, 95% confidence interval (CI) 0.16 to 0.78, p = 0.008). The incidence of proximal DVT in the early release group (1 of 196 (0.5%)) was significantly lower than in the late release group (8 of 196, 4%; OR 0.12, 95% CI 0.02 to 0.99, p = 0.020). Although the mean intra-operative blood loss was higher in the early release group, the mean post-operative drainage, total blood loss, transfusion requirements and complications were not significantly different in the two groups.

Conclusion

In patients who undergo TKA, releasing the tourniquet early is associated with a decreased incidence of DVT, without increasing the rate of complications.

Cite this article: Bone Joint Res 2017;6:535–541.