Aromatic-Carbonyl Interactions as an Emerging Type of Non-Covalent Interactions

Aromatic-carbonyl (Ar···C═O) interactions, attractive interactions between the arene plane and the carbon atom of carbonyl, are in the infancy as one type of new supramolecular bonding forces. Here the study and functionalization of aromatic-carbonyl interactions in solution is reported. A combination of aromatic-carbonyl interactions and dynamic covalent chemistry provided a versatile avenue. The stabilizing role and mechanism of arene-aldehyde/imine interactions are elucidated through crystal structures, NMR studies, and computational evidence. The movement of imine exchange equilibria further allowed the quantification of the interplay between arene-aldehyde/imine interactions and dynamic imine chemistry, with solvent effects offering another handle and matching the electrostatic feature of the interactions. Moreover, arene-aldehyde/imine interactions enabled the reversal of kinetic and thermodynamic selectivity and sorting of dynamic covalent libraries. To show the functional utility diverse modulation of fluorescence signals is realized with arene-aldehyde/imine interactions. The results should find applications in many aspects, including molecular recognition, assemblies, catalysis, and intelligent materials.

Photoswitchable dynamic conjugate addition-elimination reactions as a tool for light-mediated click and clip chemistry

Phototriggered click and clip reactions can endow chemical processes with high spatiotemporal resolution and sustainability, but are challenging with a limited scope. Herein we report photoswitchable reversible covalent conjugate addition-elimination reactions toward light-addressed modular covalent connection and disconnection. By coupling between photochromic dithienylethene switch and Michael acceptors, the reactivity of Michael reactions was tuned through closed-ring and open-ring forms of dithienylethene, allowing switching on and off dynamic exchange of a wide scope of thiol and amine nucleophiles. The breaking of antiaromaticity in transition states and enol intermediates of addition-elimination reactions provides the driving force for photoinduced change in kinetic barriers. To showcase the versatile application, light-mediated modification of solid surfaces, regulation of amphiphilic assemblies, and creation/degradation of covalent polymers on demand were achieved. The manipulation of dynamic click/clip reactions with light should set the stage for future endeavors, including responsive assemblies, biological delivery, and intelligent materials.

[Effects of long working hours exposure on occupational stress and depression symptoms in couriers in Zhejiang Province]

Objective: To understand the current situation of long working hours exposure of couriers in Zhejiang Province, and to analyze the influence of long working hours exposure levels on their occupational stress and depression symptoms, and provide a basis for promoting the physical and mental health of couriers. Methods: From September to December 2021 , 1159 couriers from Zhejiang Express Transport Companies were selected as respondents by cluster sampling, and their basic information were collected. The occupational stress and depression symptoms of the couriers were assessed using the Core Occupational Stress Scale (COSS) and the Patient Health Questionnaire-9 (PHQ-9). The effects of long work hours (>48 h per week) on the occupational stress and depression symptoms of the couriers were analyzed. Results: The average age of 1159 courier in Zhejiang Province was (33.24±8.42) years, the average weekly working hours were (63.21±18.77) h, and 75.15% (871/1159) were long-term workers. The detection rates of occupational stress and depression symptoms in courier were 32.44% (376/1159) and 32.53% (377/1159), respectively. There were significant differences in the detection rates of occupational stress and depression symptoms among couriers with different ages, educational background, marital status, monthly average income, length of service, position or post, shift status, drinking status, and average weekly working hours (P <0.05). The adjusted logistic regression analysis showed that, after adjusting for the influence of confounding factors such as age, educational background, marital status, monthly average income, length of service, position or post, shift status and drinking status, compared with the weekly working hours ≤48 h, weekly working hours of 63-77 h, 78-92 h, ≥93 h were the risk factors for occupational stress (OR=1.547, 95%CI: 1.019-2.350; OR=1.886, 95%CI: 1.184-3.006; OR=2.338, 95%CI: 1.188-4.062) and depression symptoms (OR=1.897, 95%CI: 1.258-2.860; OR=2.041, 95%CI: 1.290-3.230; OR=4.978, 95%CI: 2.551-9.715) of couriers (P<0.05) . Conclusion: Long working hours could increase the risk of occupational stress and depression symptoms among couriers. It is necessary to arrange working hours reasonably to reduce the occurrence of occupational stress and depression symptoms of couriers.

Dynamic Covalent Reactions and Chirality Sensing with Diphenylethene Derived Hemiaminals

The differentiation of enantiomers is of significance in synthetic chemistry and pharmaceutical chemistry. Herein, we report a facile method for chirality sensing of monoalcohols, a challenging target due to the poor reactivity, by combining dynamic covalent chemistry with helical chirality. Four diphenylethene (DPE) derived cyclic hemiaminals were constructed, and the incorporation of a broad range of alcohols and thiols with high efficiency was achieved. The reversibility was further verified by dynamic component exchange. The helical chirality of the DPE motif was induced through chirality transfer by the central chirality of the analytes, resulting in circular dichroism responses. The chirality differentiation of seven chiral secondary alcohols including both alkyl and aryl alcohols was realized, further allowing the quantification of enantiomeric excess with high accuracy. The results described should lay a foundation for future endeavors in chemical sensing, asymmetric synthesis, and chiroptical materials.

Double n→π* Interactions with One Electron Donor: Structural and Mechanistic Insights

Double n→π* interactions between one common electron donor of the carbonyl oxygen and two individual acceptor aldehyde/imine units are presented. The structural and mechanistic insights were revealed through a collection of experimental and computational evidence. The orientation and further energetic dependence of orbital interactions were facilely regulated by the size of cyclic urea scaffolds, the bulkiness of aldehydes/imines, and the flexibility of imine macrocycles.

Genotypic Effects of the TOMM40'523 Variant and APOE on Longitudinal Cognitive Change over 4 Years: The TOMMORROW Study

BACKGROUND

The 523 poly-T length polymorphism (rs10524523) in TOMM40 has been reported to influence longitudinal cognitive test performance within APOE ε3/3 carriers. The results from prior studies are inconsistent. It is also unclear whether specific APOE and TOMM40 genotypes contribute to heterogeneity in longitudinal cognitive performance during the preclinical stages of AD.

OBJECTIVES

To determine the effects of these genes on longitudinal cognitive change in early preclinical stages of AD, we used the clinical trial data from the recently concluded TOMMORROW study to examine the effects of APOE and TOMM40 genotypes on neuropsychological test performance.

DESIGN

A phase 3, double-blind, placebo-controlled, randomized clinical trial.

SETTING

Academic affiliated and private research clinics in Australia, Germany, Switzerland, the UK, and the USA.

PARTICIPANTS

Cognitively normal older adults aged 65 to 83.

INTERVENTION

Pioglitazone tablet.

MEASUREMENTS

Participants from the TOMMORROW trial were stratified based on APOE genotype (APOE ε3/3, APOE ε3/4, APOE ε4/4). APOE ε3/3 carriers were further stratified by TOMM40'523 genotype. The final analysis dataset consists of 1,330 APOE ε3/3 carriers and 7,001 visits. Linear mixed models were used to compare the rates of decline in cognition across APOE groups and the APOE ε3/3 carriers with different TOMM40'523 genotypes.

RESULTS

APOE ε3/4 and APOE ε4/4 genotypes compared with the APOE ε3/3 genotype were associated with worse performance on measures of global cognition, episodic memory, and expressive language. Further, over the four years of observation, the APOE ε3/3 carriers with the TOMM40'523-S/S genotype showed better global cognition and accelerated rates of cognitive decline on tests of global cognition, executive function, and attentional processing compared to APOE ε3/3 carriers with TOMM40'523-S/VL and VL/VL genotypes and compared to the APOE ε3/4 and APOE ε4/4 carriers.

CONCLUSIONS

We suggest that both APOE and TOMM40 genotypes may independently contribute to cognitive heterogeneity in the pre-MCI stages of AD. Controlling for this genetic variability will be important in clinical trials designed to slow the rate of cognitive decline and/or prevent symptom onset in preclinical AD.

Tuning the selectivity of amino acid recognition with dynamic covalent bond constrained fluorophores in aqueous media

The recognition and discrimination of amino acids are generating continuous interest due to their importance. Herein we developed a series of dynamic covalent reaction constrained aldehyde-derived fluorescent probes for the binding of amino acids with tunable selectivity. Diverse emission behaviors were obtained via pH triggered movement of ring-chain tautomerization equilibrium of aldehyde probes. By taking advantage of the distinct pK_a and reactivity of aldehyde probes and amino acids, unique fluorescence signaling patterns were generated, and the selectivity for amino acid recognition was further modulated. The selective recognition of Cys/Hcy was attained at pH 7.4 as a result of thiazolidine formation. The manipulation of the reactivity at pH 10 enabled the realization of high selectivity for His and Cys, respectively. Moreover, pH and redox stimuli-responsive dynamic covalent networks were constructed for the regulation of amino acid recognition. The strategies and results described should be appealing in many aspects, including dynamic assemblies, molecular sensing, biological labeling, and smart materials.

Light-Induced Formation/Scission of C-N, C-O, and C-S Bonds Enables Switchable Stability/Degradability in Covalent Systems

The manipulation of covalent bonds could be directed toward degradable, recyclable, and sustainable materials. However, there is an intrinsic conflict between properties of stability and degradability. Here we report light-controlled formation/scission of three types of covalent bonds (C-N, C-O, and C-S) through photoswitching between equilibrium and nonequilibrium states of dynamic covalent systems, achieving dual benefits of photoaddressable stability and cleavability. The photocyclization of dithienylethene fused aldehyde ring-chain tautomers turns on the reactivity, incorporating/releasing amines, alcohols, and thiols reversibly with high efficiency, respectively. Upon photocycloreversion the system is shifted to kinetically locked out-of-equilibrium form, enabling remarkable robustness of covalent assemblies. Reaction coupling allows remote and directional control of a diverse range of equilibria and further broadens the scope. Through locking and unlocking covalent linkages with light when needed, the utility is demonstrated with capture/release of bioactive molecules, modification of surfaces, and creation of polymers exhibiting tailored stability and degradability/recyclability. The versatile toolbox for photoswitchable dynamic covalent reactions to toggle matters on and off should be appealing to many endeavors.

[The study of the impact by atractylenolide-1 on inflammatory cytokine, autophagy and apoptosis in alveolar macrophages of silicosis patients]

Objective: To explore the effect of atractylenolide-1 (ATL-Ⅰ) on alveolar macrophages in silicosis patients. Methods: In December 2019, 12 male silicosis patients treated in Beidaihe Sanatorium for Chinese Coal Miners from July to September 2019 were selected by random sampling. Their alveolar macrophages were collected and divided into control group, ATL-Ⅰ group (100 μmol/L) and dimethyl sulfoxide (DMSO) group (100 μmol/L) . The exprossion levels of inflammatory factor interleukin-1β (IL-1β) , interleukin-6 (IL-6) , tumor necrosis factor α (TNF-α) were detected by enzyme-linked immunosorbent assay. The expression levels of autophagy associated protein microtubule associated protein light chain 3 (LC3) , autophagy substrate protein p62, lysosome associated membrane protein 2 (LAMP2) , apoptosis associated protein Cleaved caspase-3, nuclear factor kappa B (NF-κB) and its phosphorylated form (p-NF-κB) were detected by Western blot. Results: Compared with the control group and DMSO group, the expression levels of IL-1β, IL-6, TNF-α in alveolar macrophages decreased significantly in the ATL-Ⅰ group (P<0.05) , and the expression levels of p-NF-κB, the ratio of LC3-Ⅱ/LC3-Ⅰ also decreased significantly in the ATL-Ⅰ group (P<0.05) . However, the expression levels of NF-κB, LAMP2, p62 and Cleaved caspase-3 in the ATL-Ⅰ group were not statistically different from those in the control group and DMSO group (P>0.05) . There was no statistically significant differences in the expression of the above indexes between the control group and DMSO group (P>0.05) . Conclusion: ATL-Ⅰ may reduce the release of inflammatory factors from alveolar macrophages and inhibit the activity of autophagy in silicosis patients, but it may not reduce the level of apoptosis.

Endoscopic sinus surgery improves Eustachian tube function in patients with chronic rhinosinusitis: a multicenter prospective study

BACKGROUND

Patients with chronic rhinosinusitis (CRS) often have Eustachian tube dysfunction (ETD) symptoms. This study aimed to prospectively investigate the effect of endoscopic sinus surgery (ESS) on improvement of Eustachian tube function in CRS patients with ETD from a Chinese population and determine factors associated with improvement.

METHODS

A prospective study was performed in CRS patients with ETD who underwent ESS from 3 tertiary medical centers in south China. The Eustachian tube Dysfunction Questionnaire 7 (ETDQ-7), Sinonasal Outcome Test 22 (SNOT-22), tympanograms, endoscopic findings and Valsalva maneuver were recorded and analyzed preoperatively and postoperatively at 8-12 weeks.

RESULTS

A total of 70 CRS patients with ETD were included in this study. The ETDQ-7 score and the ability of positive Valsalva maneuver in CRS patients were significantly improved postoperatively at 8-12 weeks. The number of patients with type A tympanogram was increased postoperatively. Reduced Eustachian tube mucosal inflammation was also observed postoperatively. In addition, ESS appeared to reverse slight tympanic membrane atelectasis after 8-12 weeks. Moreover, improvement in tympanogram was presented in more than half of CRS patients with concomitant otitis media with effusion postoperatively at 8-12 weeks. Univariate and multivariate analysis revealed failure of normalization of ETDQ-7 postoperatively was associated with concomitant allergic rhinitis and higher preoperative SNOT-22 score.

CONCLUSIONS

This study confirms Eustachian tube function is often improved after ESS in CRS patients with ETD. Concomitant allergic rhinitis and higher preoperative SNOT-22 score are associated with failure of normalization of ETD symptoms.

[Evaluation of kurtosis on hearing loss caused by non-steady state noise in general equipment manufacturing industry]

Objective: To study the effect of occupational exposure to non-steady state noise on hearing loss in the general equipment manufacturing industry, and to explore the feasibility of applying kurtosis index to evaluate hearing loss caused by non-steady state noise. Methods: A total of 233 workers exposed to non-steady state noise in 6 general equipment manufacturing enterprises were selected as the observation group, and 237 workers exposed to steady noise in 4 textile enterprises were selected as the control group between 2012 and 2018. Personal normalized continuous A-weighted sound pressure level equivalent to an 8 h-working-day (L(Aeq, 8 h)) was determined by a noise dosimeter. Cumulation noise exposure (CNE) was calculated from L(Aeq, 8 h) and related working age, and the CNE was adjusted by using noise kurtosis (CNE' after adjustment) . Meanwhile, questionnaires and hearing loss tests were performed for all subjects. The changes in the threshold of high-frequency hearing and the incidence of high-frequency hearing loss caused by noise in the two groups were compared before and after the adjustment of the kurtosis of CNE. The correlation between CNE and the incidence of high-frequency hearing loss before and after kurtosis adjustment was analyzed. Results: There was an difference between the 3000-8000 Hz hearing threshold of workers in different CNE groups (P<0.05) . logistic regression analysis showed that CNE was a risk factor of high-frequency hearing loss for workers in the observation group (OR=1.189, P<0.05) , and trend Chi-square test showed that the incidence of high-frequency hearing loss increased with CNE levels (χ(2)(trend)=34.415, P<0.05) .Before the kurtosis adjustment, in the CNE 95~<110 dB (A) ·year level group, the incidence of high-frequency hearing loss and the high-frequency hearing threshold in the observation group were significantly higher than those in the control group (P<0.05) . After kurtosis adjustment, there was no significant difference in the incidence of high-frequency hearing loss between the observation group and the control group in each level group (P>0.05) . The correlation between CNE after kurtosis adjustment and the incidence of high-frequency hearing loss was better than that before adjustment (after R(2) adjustment >before R(2) adjustment) . Conclusion: The effect of non-steady state noise on high-frequency hearing loss of workers in general equipment industry increases with the increase of CNE, and the effect of non-steady state noise on high-frequency hearing loss of workers is greater than that of steady noise. CNE' can be used to evaluate the hearing loss caused by non-steady state noise.

Psychological stress and its correlates in Chinese patients with acute coronary syndrome

Funding Acknowledgements

None.

Background

Psychological stress is associated with high incidence of coronary heart disease and increases the risk of mortality and poor health status. Although a few studies have investigated psychological stress in this population, this problem is usually unrecognized and untreated in most Chinese patients with acute coronary syndrome. There is insufficient information regarding the features of psychological stress and associated factors among this population.

Purpose

This study aimed to assess the level of psychological stress and to identify its correlates in Chinese patients with acute coronary syndrome.

Methods

Patients aged over 18 years and with acute coronary syndrome were invited to participate in a cross-sectional survey in two tertiary public hospitals in China, from June to July 2019. A total of 332 patients completed measures of sociodemographic and clinical characteristics, psychological stress (10-item Perceived Stress Scale), and illness perception (Brief Illness Perceptions Questionnaire). Independent sample t-tests, bivariate correlations, and multivariable linear regression were performed to analyze potential correlates, including age, gender, education level, employment status, income, episode of illness, revascularization procedure, comorbidities, body mass index, blood pressure, blood glucose, blood lipids, and illness perception.

Results

The average patient age was 62.2 years, 67.5% were male, and 54.2% had less than high school education. The mean score for psychological stress was 21.30 ± 3.99 and 66.9% of patients had high psychological stress (score ≥ 20). Multivariable regression analysis showed that being overweight/obesity versus normal weight (body mass index:  ≥ 24 kg/m2 versus &lt; 24 kg/m2) was associated with lower psychological stress (β =  -0.134, p = 0.007). Having a high level of fasting blood glucose (≥ 6.1 mmol/L) versus normal fasting blood glucose (&lt; 6.1 mmol/L) was associated with high psychological stress (β = 0.123, p = 0.017). Additionally, negative cognitive illness perception (β = 0.190, p = 0.01), negative emotional illness perception (β = 0.290, p &lt; 0.001), and poor illness understanding (β = 0.118, p = 0.032) were associated with high psychological stress.

Conclusions

Patients with acute coronary syndrome experience high psychological stress that is significantly correlated with body mass index, fasting blood glucose, and illness perception. Health professionals should recognize this issue and interventions looking to relive psychological stress may benefit from targeting these correlates.

POS0884 THE ENHANCED LIVER FIBROSIS (ELF) SCORE AS A BIOMARKER OF SKIN FIBROSIS IN SYSTEMIC SCLEROSIS

Background:

Serum fibrotic markers for systemic sclerosis (SSc) remain limited. The Enhanced Liver Fibrosis (ELF) score, originally derived and validated in patients with chronic liver disease, is an algorithm combining 3 serum markers, known as procollagen type III amino terminal propeptide (PIIINP), tissue inhibitor of metalloproteinases 1 (TIMP-1), and hyaluronic acid (HA). The combined score was proved to be superior to the single components in reflecting the severity of liver fibrosis. However, the performance of ELF score and its components has not been fully validated in SSc.

Objectives:

To investigate PIIINP, TIMP-1, HA, and the combined algorithm ELF score as fibrotic markers for SSc skin involvement.

Methods:

Eighty SSc patients (44 dcSSc and 36 lcSSc), fulfilling the 2013 ACR/EULAR criteria with the absence of chronic liver diseases, were enrolled. Eighty age- and sex- matched healthy controls were also included. Serum PIIINP and HA levels were quantified by chemiluminescence immunoassay. Serum TIMP-1 levels were determined by enzyme-linked immunosorbent assay. The ELF score was calculated using the formula ELF score= 2.494 + 0.846*ln(HA) + 0.735*ln(PIIINP) + 0.391*ln(TIMP-1). Results were correlated with clinical profiles including modified Rodnan skin score (mRSS) and interstitial lung disease (ILD).

Results:

Compared with healthy controls, patients with SSc showed significantly elevated serum PIIINP (11.2±4.8 vs. 5.73±1.4μg/L, p<0.001), TIMP-I (123.7±78.6 vs. 67.8±26.5 ng/ml, p<0.001), and ELF score (10.5±0.9 vs. 9.7±0.4, P<0.001). Even higher levels of PIIINP, TIMP-1, and ELF score were observed in dcSSc patients, compared with lcSSc patients (p<0.001, p=0.024, p=0.003, respectively). No significant difference was found in the levels of serum HA between patients and controls. Strong correlations were observed between mRSS and ELF score (r=0.54, p<0.001), and between mRSS and PIIINP(r=0.62, p<0.001), whereas only weak correlations could be observed between mRSS and TIMP-1 (r=0.28, p=0.02), and between mRSS and HA (r=0.26, p=0.03). When stratified by ELF score, using cutoffs proposed for liver fibrosis and cirrhosis, SSc patients with ELF<9.8 showed the lowest mRSS on average, while patients with ELF>11.3 showed the highest (p<0.001). When stratified by serum PIIINP levels, using the 25th and 75th percentiles, SSc patients with serum PIIIINP levels<7.8μg/L showed the lowest mRSS on average, while patients with PIIINP>14.0μg/L showed the highest (p<0.001). Neither the ELF score nor its components showed significant difference between patients with and without ILD.

Conclusion:

The ELF score could be used for reflecting the severity of overall skin involvement in SSc, and serum PIIINP also increased in parallel with the increase of mRSS. Longitudinal prospective studies exploring ELF score or serum PIIINP as fibrotic markers and outcome measures of SSc are warranted.

References:

[1]Lichtinghagen R, Pietsch D, Bantel H, et al. The Enhanced Liver Fibrosis (ELF) score: Normal values, influence factors and proposed cut-off values. Journal of Hepatology. 2013; 59: 236-42.

[2]Abignano G, Blagojevic J, Bissell LA, et al. European multicentre study validates enhanced liver fibrosis test as biomarker of fibrosis in systemic sclerosis. Rheumatology. 2019; 58: 254-59.

Figure 1.

Correlations of mRSS with ELF score (A) and serum PIIINP (B) and distribution of mRSS among different ELF (C) and PIIINP (D) ranges.

Acknowledgements:

The authors have no acknowledgements to declare.

Disclosure of Interests:

None declared

POS0869 PREDICTIVE VALUE OF ANTI-INTERFERON-INDUCIBLE PROTEIN 16 ANTIBODIES FOR DIGITAL ULCERS OF SYSTEMIC SCLEROSIS

Background:

Interferon-inducible protein 16 (IFI-16) is constitutively expressed in vascular endothelial cells and can inhibit the proliferation of human endothelial cells and the formation of capillary-like structures in vitro. Anti-IFI-16 antibodies were reported in 21%-29% of patients with systemic sclerosis (SSc) and were associated with digital vascular events in a few retrospective studies.

Objectives:

To evaluate the presence and the clinical implication of anti-IFI-16 antibodies in Chinese SSc cohort, focusing on the associations with vasculopathy indexes, and to investigate the predictive value of anti-IFI-16 antibodies for the development of digital ulcers (DUs) in SSc prospectively.

Methods:

Patients with SSc presenting to our center between July 2018 and September 2018 were prospectively enrolled. Serum from 42 SSc patients and 42 age- and sex-matched healthy controls were analyzed for anti-IFI-16 antibodies by enzyme-linked immunosorbent assay (ELISA), and was considered positive if the optical density (OD) value was above the mean OD of controls plus two standard deviations. Tissue immunofluorescence was used to evaluate the expression of IFI16 in skin biopsy samples obtained from SSc patients and normal controls. At baseline, nailfold video-capillaroscopy was performed to assess nailfold capillary density of SSc patients. Power Doppler ultrasound was used to grade finger pulp blood flow (0-no observed flow; 1-decreased flow; 2-normal flow), and to measure ulnar and radial artery blood flow and resistive index (RI). All patients were followed up for 6 months to see whether they experienced new onset or recurrent DUs. The association of anti-IFI-16 antibodies with DUs was analyzed using logistic regression.

Results:

Of the 42 SSc patients, 8 (19.0%) were positive for anti-IFI-16 antibodies. Immunofluorescence of skin biopsy samples from SSc patients exhibited enhanced staining of IFI-16 in the dermis, and colocalization with endothelial marker CD31. SSc patients who were positive for anti-IFI-16 antibodies showed higher ulnar artery RI at baseline (0.95±0.09 vs. 0.86±0.09, p=0.015), while no significant differences were found for other vascular parameters, nor for clinical or demographic profiles. Within 6-month follow-up, 14 (33.3%) patients experienced new-onset or recurrent DUs. Univariate logistic regression revealed the presence of DUs at enrollment (p=0.009), anti-IFI-16 antibody (p=0.012), finger pulp blood flow (p=0.027), and ulnar artery RI (p=0.008) could be the predictors for the development of DUs. Multivariate analysis further identified DUs at enrollment (odds ratio [OR]: 10.85; 95% confidence interval [CI]: 1.61-73.18; p=0.014) and anti-IFI-16 antibody (OR: 15.00; 95% CI: 1.13-199.18; p=0.040) as independent risk factors. Among patients without DUs at enrollment, new-onset ulcers occurred in 80% (4/5) and 4.5% (1/22) of those with and without anti-IFI-16 antibody, respectively (p=0.001).

Conclusion:

Anti-IFI-16 antibody is associated with vasculopathy in SSc and could be used as a novel biomarker for indicating the development of DUs.

References:

[1]McMahan ZH, Shah AA, Vaidya D, et al. Anti-interferon-inducible protein 16 antibodies associate with digital gangrene in patients with Scleroderma. Arthritis Rheumatol. 2016; 68(5): 1262-71.

[2]McMahan ZH, Cottrell TR, Wigley FM, et al. Autoantigens targeted in scleroderma patients with vascular disease are enriched in endothelial lineage cells. Arthritis Rheumatol. 2016; 68(10): 2540–49.

Figure 1.

Multivariate logistic analysis for new or recurrent digital ulcers.

Acknowledgements:

The authors would like to thank Doctor Yi Cheng for performing Power Doppler ultrasound assessment.

Disclosure of Interests:

None declared

High pressure homogenization inactivation of Escherichia coli and Staphylococcus aureus in phosphate buffered saline, milk and apple juice

High pressure homogenization (HPH) offers new opportunities for food pasteurization/sterilization. Escherichia coli and Staphylococcus aureus suspended in phosphate buffered saline (PBS) buffer, milk and apple juice at initial concentration of ~10⁶ log₁₀ CFU per ml were subjected to HPH treatments up to 200 MPa with inlet temperatures at 4-40°C. After HPH at 200 MPa with the inlet temperature at 40°C, the count of E. coli suspended in PBS, milk and apple juice reduced by 3·42, 3·67 and 3·19 log₁₀ CFU per ml respectively while the count of S. aureus decreased by 2·21, 1·02 and 2·33 log₁₀ CFU per ml respectively suggesting that S. aureus was more resistant. The inactivation data were well fitted by the polynomial equation. Milk could provide a protective effect for S. aureus against HPH. After HPH at 200 MPa with the inlet temperature at 20°C, the cell structure of E. coli was destroyed, while no obvious damages were found for S. aureus.

Dynamic covalent bond constrained ureas for multimode fluorescence switching, thermally induced emission, and chemical signaling cascades

A combination of organic ureas and dynamic covalent chemistry was demonstrated for multistate switching, thermally induced fluorescence, and signaling cascades.

Involvement of nitrogen in storage root growth and related gene expression in sweet potato (Ipomoea batatas)

Nitrogen (N) could affect storage root growth and development of sweet potato. To manage external N concentration fluctuations, plants have developed a wide range of strategies, such as growth changes and gene expression. Five sweet potato cultivars were used to analyse the functions of N in regulating storage root growth. Growth responses and physiological indicators were measured to determine the physiological changes regulated by different N concentrations. Expression profiles of related genes were analysed via microarray hybridization data and qRT-PCR analysis to reveal the molecular mechanisms of storage root growth regulated by different N concentrations. The growth responses and physiological indicators of the five cultivars were changed by N concentration. The root fresh weight of two of the sweet potato cultivars, SS19 and GS87, was higher under low N concentrations compared with the other cultivars. SS19 and GS87 were found to be having greater tolerance to low N concentration. The expression of N metabolism and storage root growth related genes was regulated by N concentration in sweet potato. These results reveal that N significantly regulated storage root growth. SS19 and GS87 were more tolerant to low N concentration and produced greater storage root yield (at 30 days). Furthermore, several N response genes were involved in both N metabolism and storage root growth.

Noncovalent and Dynamic Covalent Chemistry Strategies for Driving Thermoresponsive Phase Transition with Multistimuli and Controlled Encapsulation/Release

We report the development of multiresponsive thermally sensitive polymers through both supramolecular and reversible covalent strategies as well as their use in controlled encapsulation and release. Novel acylhydrazone-based dynamic covalent polymers displaying lower critical solution temperature (LCST) or upper critical solution temperature (UCST) were synthesized. A remarkable control over thermal phase transition can be tuned through multimodes, such as anions, cations, solvent, pH, and competing components. In particular, anion recognition allowed disassembly and thus led to a significant decrease of UCST in dimethyl sulfoxide, and the combination of anion and solvent effects offered additional handle for control. Moreover, the use of anions, cations, as well as pH change was employed for the modulation of LCST-type polymer in water. Furthermore, switching on/off thermoresponsiveness was readily achieved by dynamic covalent exchange. Mechanistic studies also shed light on stimuli-induced changes in aggregation behaviors. Finally, thermally controlled encapsulation and release of hydrophobic and hydrophilic dyes were realized with great repeatability and reversibility, respectively, showing potential in delivery and sensing. The results and strategies described should provide opportunities for many aspects, including dynamic assemblies, complex systems, and adaptive materials.

P191 The effectiveness of mindfulness-based interventions on perceived stress, depression and anxiety in patients with coronary heart disease: A systematic review and meta-analysis

Background

An increasing number of people are living with coronary heart disease (CHD) globally. Psychological conditions such as stress, depression, and anxiety are prevalent for people with CHD, which impose a great challenge for secondary prevention of CHD. Mindfulness-based interventions (MBIs), which incorporate mindfulness skills and cognitive or behavioural therapy, are suggested as a promising approach to help patients with CHD to improve their psychological health. However, the effectiveness of MBIs for patients with CHD has not been systematically reviewed.

Purpose

To synthesise the evidence regarding the effects of MBIs on reducing perceived stress, depression, and anxiety in patients with CHD.

Methods

  Search was conducted in seven English electronic databases and two Chinese electronic databases from inception to January 2019. Randomized controlled trials (RCTs) that evaluated the effects of MBIs on stress, depression, and anxiety in adults with CHD were included. Two reviewers independently screened records for eligibility, extracted data, and assessed risks of bias using the Cochrane tool. Meta-analysis was conducted by combining the standard mean difference (SMD) with 95% confidence interval (CI) of post-intervention outcome measures using Review Manager Version 5.3. We used a fixed-effects model if no significant heterogeneity (I² &lt; 50%), while in case of significant heterogeneity (50% &lt; I² &lt; 75%), we used a random-effects model.

Results

Six RCTs involving 473 participants were included. Five of all studies compared MBIs with inactive controls (i.e., usual care and waitlist control). The remaining study utilized a self-help group that received a booklet containing identical mindfulness information as an active control. There were high concerns about the risk of bias across studies, mainly in performance bias and detection bias. The meta-analysis of two studies showed MBIs may reduce perceived stress at post-intervention (SMD -0.82; 95% CI -1.28 to -0.36; P &lt; 0.001; I² 0%) compared with inactive controls. Compared with active control, the single study did not observe a significant reduction of perceived stress in intervention group. The meta-analysis of five studies revealed that MBIs appear effective in reducing depression (SMD -1.08; 95% CI -1.28 to -0.87; P &lt; 0.001; I² 22%) and anxiety (SMD -1.16; 95% CI -1.57 to -0.75; P &lt; 0.001; I² 71%) immediately after intervention, compared with inactive or active controls.

Conclusions

The results of this review provide evidence for the effects of MBIs on reduction in perceived stress, depression and anxiety at post-intervention in patients with CHD. However, these findings need to be interpreted with caution given the small sample size and methodological limitations within included studies. Rigorous-designed research is urgently needed to further confirm the effectiveness of MBIs on improving psychological health and explore its sustainable effects in patients with CHD.

Psychometric assessment and application of the Chinese version of the Compliance with Annual Diabetic Eye Exams Survey in people with diabetic retinopathy

AIM

To translate the Compliance with Annual Diabetic Eye Exams Survey (CADEES) into Chinese, allowing assessment of its reliability and validity, and to identify variables that predict attendance at annual eye examinations.

METHODS

People with vision-threatening diabetic retinopathy were recruited from the Shanghai Diabetic Eye Study. The study involved three phases: (1) translation and cross-cultural adaptation, (2) a pilot study (n = 496) to evaluate the psychometric properties of the Chinese-CADEES, and (3) a primary cross-sectional survey (n = 3818) to assess self-reported attendance at annual eye examinations. Factors related to non-attendance were identified using univariate analysis, and then a multiple logistic regression model. Finally, a component model and individual item models were built to predict attendance.

RESULTS

The Chinese-CADEES had satisfactory reliability and validity. The issue of low attendance at annual eye examinations was serious. In addition to 13 health belief items, living in semi-urban suburban areas, shorter duration of diabetes, poor glucose control, lower education level, better presenting visual acuity and milder diabetic retinopathy diagnosis were significantly related to non-attendance. The multivariate predictive model was able to predict, with 64.7% accuracy, whether or not participants were going to attend annual eye examinations and explained ~ 11.3% of the variance in attendance.

CONCLUSIONS

The Chinese-CADEES showed good reliability and validity for predicting attendance at annual eye examinations in people with diabetic retinopathy. Clinicians and researchers can improve attendance by addressing modifiable characteristics and increasing education on diabetic retinopathy and the importance of eye health in people with diabetes.

MiR-10b regulates the proliferation and apoptosis of pediatric acute myeloid leukemia through targeting HOXD10

OBJECTIVE

To investigate the role of miR-10b in the proliferation and apoptosis of acute myeloid leukemia (AML), and to explore the underlying mechanism.

PATIENTS AND METHODS

The expression level of miR-10b in clinical AML cases and cell lines was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The interaction between miR-10b and homeobox D10 (HOXD10) was confirmed by qRT-PCR, Western blotting and Luciferase assay. The effect of miR-10b on biological functions of AML cell line (HL60) was analyzed in vitro. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and colony formation assay were used to detect the proliferation and colony formation ability of AML cells, respectively. Meanwhile, flow cytometry and TUNEL staining were applied to measure cell cycle and apoptosis of AML cells, respectively.

RESULTS

miR-10b was significantly up-regulated in AML cases and cell lines. The potential target genes of miR-10b were analyzed by three public databases. Results showed that HOXD10 was a direct target of miR-10b. QRT-PCR, Western blotting and luciferase assay confirmed the regulatory effect of miR-10b on HOXD10. Overexpression of miR-10b accelerated the proliferation and colony formation ability of AML cells. Meanwhile, miR-10b overexpression decreased the percentage of AML cells in the G0/G1 phase when compared with S phase, and suppressed the apoptosis of AML cells. However, the addition of HOXD10 could reverse the effects of miR-10b.

CONCLUSIONS

MiR-10b could regulate the proliferation, colony formation, cell cycle and apoptosis of AML cells through targeting HOXD10, indicating that miR-10b might be a potential therapeutic target for the treatment of AML.

Dynamic Covalent Switches and Communicating Networks for Tunable Multicolor Luminescent Systems and Vapor-Responsive Materials

Molecular switches are an intensive area of research, and in particular, the control of multistate switching is challenging. Herein we introduce a general and versatile strategy of dynamic covalent switches and communicating networks, wherein distinct states of reversible covalent systems can induce addressable fluorescence switching. The regulation of intramolecular ring/chain equilibrium, intermolecular dynamic covalent reactions (DCRs) with amines, and both permitted the activation of optical switches. The variation in electron-withdrawing competition between the fluorophore and 2-formylbenzenesulfonyl unit afforded diverse signaling patterns. The combination of switches in situ further enabled the creation of communicating networks for multistate color switching, including white emission, through the delicate control of DCRs in complex mixtures. Finally, reversible and recyclable multiresponsive luminescent materials were achieved with molecular networks on the solid support, allowing visualization of different types of vapors and quantification of primary amine vapors with high sensitivity and wide detection range. The results reported herein should be appealing for future studies of dynamic assemblies, molecular sensing, intelligent materials, and biological labeling.

Quantum Criticality of the Ising-like Screw Chain Antiferromagnet SrCo_{2}V_{2}O_{8} in a Transverse Magnetic Field

The quantum criticality of an Ising-like screw chain antiferromagnet SrCo_{2}V_{2}O_{8}, with a transverse magnetic field applied along the crystalline a axis, is investigated by ultralow temperature NMR measurements. The Néel temperature is rapidly and continuously suppressed by the field, giving rise to a quantum critical point (QCP) at H_{C_{1}}≈7.03  T. Surprisingly, a second QCP at H_{C_{2}}≈7.7  T featured with gapless excitations is resolved from both the double-peak structure of the field-dependent spin-lattice relaxation rate 1/^{51}T_{1} at low temperatures and the weakly temperature-dependent 1/^{51}T_{1} at this field. Our data, combined with numerical calculations, suggest that the induced effective staggered transverse field significantly lowers the critical fields, and leads to an exposed QCP at H_{C_{2}}, which belongs to the one-dimensional transverse-field Ising universality.

[Comparison of etiology and incidence of pulmonary infection in patients with esophageal carcinoma accompanied by esophagotracheal fistula before and after the airway stent implantation]

Objective: To compare the etiology and incidence of pulmonary infection in patients with esophageal carcinoma accompanied by esophagotracheal fistula before and after the airway stent implantation. Methods: The clinical records of patients with esophageal carcinoma accompanied by esophagotracheal fistula in Respiratory Department and Oncology Department of Meitan General Hospital were retrospectively analyzed from March 2008 to January 2018. The demographic data, comorbidities, pathological results and etiology were collected before and after tracheal stents were implanted in all patients. The incidence of pulmonary infection was analyzed, and the classification of etiology was compared before and after tracheal stents implantation. Results: A total of 100 patients were included in the study. The incidence rate of pulmonary infection before stents implantation was 83.0%. A total of 105 bacterial strains were cultured, including 73 strains of gram-negative bacteria (69.5%) and mainly pseudomonas aeruginosa, 5 strains of gram-positive bacteria [all methicillin-resistant staphylococcus aureus (MRSA)] (4.8%), and 27 strains of fungi (25.7%) and mainly candida albicans. The incidence rate of pulmonary infection was lowered to 53.0% after tracheal stents implantation (χ(2)=29.102, P<0.001). A total of 79 bacterial strains were cultured, and the main bacteria were still gram-negative bacteria and fungi, in which pseudomonas aeruginosa and candida albicans accounted for the majority. However, 13 strains of MRSA were cultured (16.5%), significantly higher than those before stents implantation (χ(2)=7.451, P=0.005). Conclusions: The incidence rate of pulmonary infection in patients with esophageal carcinoma accompanied by esophagotracheal fistula is very high. Gram-negative bacteria and fungi are the main etiologies. Tracheal stents implantation can effectively reduce the incidence of pulmonary infection. However, the incidence rate of MRSA is significantly increased after stents implantation.

Epidemiological characteristics and associated factors of acute hepatitis A outbreak among HIV-coinfected men who have sex with men in Taiwan, June 2015-December 2016

In Taiwan, an outbreak of acute hepatitis A (AHA) infection has been identified since June 2015. Approximately half of the cases occurred in HIV-infected men who have sex with men (MSM). We used the Taiwan Centers for Disease Control (TCDC)-operated National Disease Surveillance Systems (NDSS) to identify the incidence of AHA during 2011-2016. Between June 2015 and December 2016, a total of 1268 AHA cases were documented, and 601 cases (47.4%) were co-infected with HIV; the majority of whom were MSM (98.4%). Each AHA case was matched to two HIV-infected controls without AHA reported in the NDSS on age (± 5 years), risk factor of HIV infection, HIV diagnosis date (± 30 days) and county/city of residence at HIV diagnosis. Three hundred forty-three HIV/AHA cases were matched to 686 controls. In multivariable conditional logistic regression analysis, a previous gonorrhoea (adjusted OR=1.77, 95% CI 1.16-2.70) and recent (aOR=6.77, 95% CI 4.34-10.55) or remote syphilis report (aOR=3.56, 95% CI 2.48-5.13) were independently associated with AHA. The epidemic persisted till December 2016, and the cases with a new diagnosis of HIV infection after AHA (28/301, 9.3%) increased after July 2016 (P = .001). HIV/AHA cases were centralized in northern and central metropolitan areas and HIV-infected MSM with a recent history of sexually transmitted diseases in Taiwan. We recommend surveillance of associated behavioural and virologic characteristics and HAV counselling and testing for HIV-infected men.

Three Switchable Orthogonal Dynamic Covalent Reactions and Complex Networks Based on the Control of Dual Reactivity

Achieving complexity is central to the creation of chemical systems, inspired by natural systems. Herein we introduce a strategy of switchable orthogonal dynamic covalent chemistry (DCC) toward the regulation of complex dynamic networks. The control of dual reactivity of tautomers and resulting pathways allowed reversible covalent bonding of a large scope of primary amines, secondary amines, alcohols, and thiols with high efficiency. The selection of reaction pathways next enabled the realization of orthogonal but switchable dynamic covalent reactions (DCRs) with nucleophile pairs of amine/alcohol, alcohol/thiol, and amine/thiol by varying protonation and oxidation states. Control experiments confirmed the crucial role of dual reactivity on the stability and switchability of DCRs. The specificity toward amines, alcohols, and thiols, as well as interconversion between their corresponding assemblies, was further accomplished in one vessel, thus creating tunable communicating networks with three types of DCRs. Moreover, the switchable orthogonality combined with differential reactivity of multiple sulfonamides and nucleophiles enhanced the complexity within dynamic libraries. The generality and versatility of our approaches should facilitate their incorporation into many aspects of chemistry endeavors.

Indazolo[3,2-b]quinazolinones Attack Hepatocellular Carcinoma Hep3B Cells by Inducing Mitochondrial-Dependent Apoptosis and Inhibition of Nrf2/ARE Signaling Pathway

BACKGROUND AND OBJECTIVE

Hepatocellular carcinoma (HCC) is the second leading cause of cancer death worldwide. Genotoxic stress resistance in patients often contributes to poor clinical outcomes, and is intensively associated to the upregulation of Nrf2/ARE signaling pathway. In this study, we examined the connection between the anticancer activity of two novel indazolo[3,2-b]quinazolinone (IQ) derivatives, IQ-7 and IQ-12, and their effect on the Nrf2/ARE signaling pathway.

METHODS

We initially measured the cytotoxicity of IQ-7 and IQ-12 in Hep3B (human hepatoma cell) and HL-7702 (normal human liver cell) cell lines, then further detected their effects on Nrf2/ARE signaling pathway and apoptosis.

RESULTS

IQ-7 and IQ-12 downregulated the expression levels of Nrf2 and its downstream target genes, such as NQO1, HO-1 and Gclc. In Hep3B cells treated with IQ-7 or IQ-12, the mitochondrial membrane potential decreased dramatically while the expression level of the pro-apoptotic protein VDAC1 and anti-apoptotic protein Bcl-2 significantly increased and decreased, respectively. In addition, IQ-7 (but not IQ-12) also induced the activity of Caspase-3. Interestingly, IQ-7 appeared to selectively inhibit Hep3B cells while having rare adverse effect on HL-7702 cells.

CONCLUSION

The two compounds were shown to induce apoptosis and inhibit the Nrf2/ARE signaling pathway in Hep3B cells, and IQ-7 was suggested a degree of specificity against cancer cells. The design of these compounds may therefore represent a new strategy for designing quinazoline derivatives that could selectively target carcinoma cells.

Bone marrow-derived mesenchymal stem cells inhibit T follicular helper cell in lupus-prone mice

Background The objective of this paper is to analyze the role of bone marrow-derived mesenchymal stem cells (BM-MSCs) on the differentiation of T follicular helper (Tfh) cells in lupus-prone mice. Methods Bone marrow cells were isolated from C57BL/6 (B6) mice and cultured in vitro, and surface markers were identified by flow cytometry. Naïve CD4⁺ T cells, splenocytes and Tfh cells were isolated from B6 mice spleens and co-cultured with BM-MSCs. The proliferation and the differentiation of CD4⁺ T cells and Tfh cells were analyzed by flow cytometry. Lupus-prone MRL/Mp-lpr/lpr (MRL/lpr) mice were treated via intravenous injection with expanded BM-MSCs, the differentiation of Tfh cells was detected, and the relief of lupus nephritis was analyzed. Results MSCs could be successfully induced from bone marrow cells, and cultured BM-MSCs could inhibit T cell proliferation dose-dependently. BM-MSCs could prevent Tfh cell development from naïve CD4⁺ T cells and splenocytes. BM-MSCs could inhibit IL-21 gene expression and cytokine production and inhibit isolated Tfh cells and STAT3 phosphorylation. In vivo study proved that BM-MSCs intravenous injection could effectively inhibit Tfh cell expansion and IL-21 production, alleviate lupus nephritis, and prolong the survival rate of lupus-prone mice. Conclusions BM-MSCs could effectively inhibit the differentiation of Tfh cells both in vitro and in vivo. BM-MSC treatment could relieve lupus nephritis, which indicates that BM-MSCs might be a promising therapeutic method for the treatment of SLE.

[Comparison of radiofrequency catheter ablation for paroxysmal supraventricular tachycardia guided by three dimensional navigation with X-ray]

Objective: To compare the therapeutic efficiency and safety of radiofrequency catheter ablation (RFCA) for paroxysmal ventricular tachycardia (PSVT) guided by three-dimensional navigation with X-ray. Methods: One hundred and seventy-six patients with PSVT hospitalized in Department of Cardiology, Zhejiang Provincial People's Hospital between January 2013 and December 2014 were enrolled in this study. RFCA was performed on 95 patients (Group A) guided by the three dimensional electric-field navigation system (NavX) and the procedures were done with the spatial localization method, unless X-ray was needed in some cases.Eighty-one patients (Group B) underwent RFCA guided by X-ray only.The success rate, complications, recurrence rate, operation time, and X-ray exposure were compared between the two groups. Results: The immediate success rate of operation was 100% in the 176 PSVT patients without complications.There were recurrences in 2 cases of Group A, while in 1 case of Group B. The average operation time in Group A was (97±20) min, while (91±26) min in Group B. The median X-ray fluoroscopy time was 3.0 min and radiation dose was 18.5 μGym² in Group A, which were significantly reduced compared with those in Group B (34.5 min, 167.3 μGym²) (P<0.05). There was no significant difference in immediate procedure success rate, complications, recurrence, and operative time between this two groups (P>0.05). Conclusions: The RFCA for PSVT guided by three-dimensional navigation is safe and feasible in the experienced electrophysiological center.Most patients suffer less or no X-ray radiation.

Multidetector computed tomography for detecting left atrial/left atrial appendage thrombus: a meta-analysis

BACKGROUND

The diagnostic accuracy of multidetector computed tomography (MDCT) in the detection of left atrial/left atrial appendage (LA/LAA) thrombus had been tested in many studies; however, the results are controversial.

AIM

The aim of the present study was to evaluate synthetically the diagnostic accuracy of MDCT in LA/LAA thrombus.

METHODS

PubMed and Embase were searched for published prospective studies which compared computed tomography with transoesophageal echocardiography (TEE) in detecting LA/LAA thrombus prior to March 2014. Descriptive and quantitative information was extracted and MetaDiSc 1.4 was used to perform a meta-analysis.

RESULTS

Fifteen prospective clinical controlled trials with 2540 patients fulfilled the inclusion criteria. The pooled sensitivities (SEN): 0.957; pooled specificities (SPE): 0.917; pooled positive likelihood ratio (PLR): 22.017; pooled negative likelihood ratio (NLR): 0.060; pooled diagnostic odds ratio (DOR): 437.43; the area under the curve (AUC): 0.9883; Q*-value: 0.9544. However, in the abovementioned indexes, the heterogeneities were statistically significant between studies (P < 0.05, inconsistency index (I(2) ) > 50%). In a sub-analysis of studies in which delayed imaging, electrocardiogram (ECG) gating and heart rate control were performed, not only the diagnostic accuracy, but also the heterogeneities were significantly improved (pooled SEN 0.991; pooled SPE 0.989; pooled PLR 60.768; pooled NLR 0.034; pooled DOR 2561.7; AUC 0.9972; Q*-value 0.9806; all the indexes' P-value were greater than 0.05 and the I(2) were 0%, except for SPE, I(2) = 54.6%).

CONCLUSION

For patients with TEE intolerance or contraindications, MDCT may be an alternative method, especially when the delayed imaging, ECG gating and heart rate control were performed.

Membrane-targeting AM-0016 kills mycobacterial persisters and shows low propensity for resistance development

Aim: To test the hypothesis that targeting the cytoplasmic membrane may be an effective way to kill persister mycobacteria and delay the emergence of resistance. Methods: In vitro activity of AM-0016, a novel xanthone-based antibacterial, was assessed against growing and persister tubercle bacilli. Resistance mutation frequencies were determined. Biochemical membrane and electron microscopic analyses were carried out. Results: AM-0016 rapidly sterilized growing tubercle bacillus cultures and displayed strong bactericidal activity against persister bacteria. Spontaneous resistance mutation frequency was lower than 10-8. Exposure to AM-0016 resulted in rapid collapse of the membrane potential. Imaging revealed deformation of the cell envelope. Conclusion: Targeting the cytoplasmic membrane may be an attractive approach to eliminate persister mycobacteria and slow down the emergence of genetic drug resistance.

Expression profiles of MMP-1 and TIMP-1 in lumbar intervertebral disc degeneration

Lumbar intervertebral disc degeneration (IDD) is a common clinical pathology and has become a focus for research in recent years. Matrix metalloproteinases (MMPs) are enzymes responsible for the degradation of almost all extracellular matrix proteins (ECM). The over-expression of MMPs or tissue inhibitors of metalloproteinases (TIMPs) may disrupt the dynamic balance of the ECM. Therefore, in the current study, the expression levels of MMP-1 and TIMP-1 in lumbar IDD patients were evaluated in an attempt to elucidate their role in IDD pathogenesis and progression. In total, 60 IDD patients were recruited as the experimental group, along with 20 cases of lumbar vertebral injury without disc degeneration as the control group. Preoperative venous blood samples were collected, and intervertebral disc tissues were collected from the lesion during surgery. Serum and tissue levels of MMP-1 and TIMP-1 were quantified by enzyme-linked immunosorbent assay and immunohistochemical staining, respectively. Serum and tissue MMP-1 levels in IDD patients were significantly higher than those in the control group (P < 0.05). Additionally, sub-group analysis revealed that severe IDD patients had higher MMP-1 levels compared with mild or moderate IDD patients (P < 0.05). However, there were no significant differences in TIMP- 1 levels in either the serum or tissues of IDD patients compared to patients in the control group (P > 0.05). These results demonstrate that MMP-1 expression is increased in IDD, with higher expression observed in more severe cases, whereas TIMP-1 expression was similarly expressed in both normal and degenerated discs.

Nonpeptidic Amphiphilic Xanthone Derivatives: Structure-Activity Relationship and Membrane-Targeting Properties

We recently reported the bioinspired synthesis of a highly potent nonpeptidic xanthone, 2c (AM-0016), with potent antibacterial activity against MRSA. Herein, we report a thorough structure-activity relationship (SAR) analysis of a series of nonpeptidic amphiphilic xanthone derivatives in an attempt to identify more potent compounds with lower hemolytic activity and greater membrane selectivity. Forty-six amphiphilic xanthone derivatives were analyzed in this study and structurally classified into four groups based on spacer length, cationic moieties, lipophilic chains, and triarm functionalization. We evaluated and explored the effects of the structures on their membrane-targeting properties. The SAR analysis successfully identified 3a with potent MICs (1.56-3.125 μ/mL) and lower hemolytic activity (80.2 μg/mL for 3a versus 19.7 μg/mL for 2c). Compound 3a displayed a membrane selectivity of 25.7-50.4. Thus, 3a with improved HC50 value and promising selectivity could be used as a lead compound for further structural optimization for the treatment of MRSA infection.

Allelic polymorphism of KIR2DL2/2DL3 in a southern Chinese population

KIR2DL2 and KIR2DL3 segregate as alleles of the same killer cell immunoglobulin-like receptor (KIR) gene locus. They have been associated with viral infectious diseases and certain cancers and their allelic information may help to better comprehend mechanisms. The allelic polymorphism of KIR2DL2/2DL3 has been shown to influence their binding specificity and affinity to the HLA-C1 ligands. The present study aims to investigate the distribution of the allelic polymorphism of KIR2DL2/2DL3 in a southern Chinese population using sequence-specific primer polymerase chain reaction (PCR-SSP) and PCR-sequence-based typing (SBT) at the entire coding sequence. Of the 306 tested individuals, 1.96% were positive for KIR2DL2 only, 78.10% for KIR2DL3 only, and 19.93% for both KIR2DL2 and 2DL3. KIR2DL3 showed a high degree of diversity in the study population with 15 alleles detected including 8 novel ones. The predominant 2DL3 allele in the study population is 2DL3*00101 (92.81%) followed by 2DL3*00201 (24.18%), 2DL3*023 (4.25%), and 2DL3*00109 (1.31%). The remaining 11 2DL3 alleles all had a frequency below 1%. Three detected 2DL2 alleles were 2DL2*00301 (18.95%), 2DL2*00101 (3.59%), and the novel 2DL2*013 (0.33%). These results provide further insight into the KIR gene diversity in Southern Chinese and may help to better understand the role played by KIR genes in associated diseases.