Safflower bud inhibits RANKL-induced osteoclast differentiation and prevents bone loss in ovariectomized mice

BACKGROUND

The powder and extract of safflower seeds are known to be effective in the prevention of bone loss in ovariectomized animals. However, the inhibitory effect and molecular mechanisms of safflower bud (SB), the germinated safflower, on bone destruction is unclear.

PURPOSE

The present study was designed to investigate the inhibitory effect and molecular mechanism of SB on osteoclastic differentiation and on bone loss in ovarietomized (OVX) mice.

METHODS

Osteoclastogenesis was determined by TRAP staining, F-actin ring formation, and bone resorption assay. NF-κB and MAPKs activation was analyzed by transfection assay and Western blot, respectively. Real-time PCR was performed to examine the expression of osteoclastogenesis-related genes. Histological changes, increases in TRAP-positive cells, and cathepsin K expression were examined in the metaphysis of OVX mice. Density of bone marrow was evaluated by µCT.

RESULTS

SB inhibited the RANKL-induced differentiation of BMDMs into osteoclasts in a dose-dependent manner. F-actin ring formation and bone resorption were also reduced by SB in RANKL-treated BMDMs. In addition, SB decreased the activation of NF-κB and MAPKs and the expression of osteoclastogenesis-related genes in BMDMs treated with RANKL. Feeding of SB-included diet prevented bone loss in OVX mice. The number of TRAP-positive cells and level of protein expression of cathepsin K was reduced and bone mineral density was increased in the metaphysis of mice fed SB compared with OVX mice.

CONCLUSION

These findings suggest that SB can be a preventive and therapeutic candidate for destructive bone diseases.

[A cohort study of HIV incidence among injecting drug users in Dehong Prefecture, Yunnan Province]

Objective: To investigate the incidence rates of HIV among injection drug users (IDU) in Dehong Prefecture, Yunnan Province. Methods: We recruited 1 413 HIV-negative IDU attending drug rehabilitation centers and identified a further 1 830 potential participants from a historical database from 2004-2009 using the same criteria. Fingerprint recognition technology was used to confirm the identity of all participants. A total of 3 243 HIV-negative IDU were recruited by the end of 2015, of which 2 546 (78.5%) had been followed up at least once since the initial data collection and 697 (21.5%) were lost to follow-up. Epidemiological data were collected through structured face-to-face interviews which included items on knowledge of AIDS, drug use, sexual activity and history of HIV testing. We collected 3-5 ml of venous blood from each subject for HIV testing. The Chi-squared test was used to compare the characteristics of those IDUs successfully followed up and those lost to follow-up. Results: We identified 226 new HIV cases among the 2 546 respondents-representing 13 907.1 person-years of follow-up and implying an average HIV incidence rate of 1.6 per 100 person-years over the entire study period (95%CI: 1.4-1.9). The incidence rate (per 100 person-years) was 2.6 (95%CI: 2.2-3.1) for the period 2004-2009 and 1.6 (95%CI: 1.0-2.3), 1.7 (95%CI: 1.1-2.4), 1.2 (95%CI: 0.8-1.9), 0.6 (95%CI: 0.3-1.1), 0.2 (95%CI:0.0-0.7), 0.5 (95%CI: 0.1-1.4) for each year from 2010 to 2015 respectively. Conclusion: Although the incidence rate of HIV remains high among IDUs in Dehong, there was a declining trend over the period studied.

[Comparative study on the HIV epidemic between the Chinese and Burmese drug users in drug rehabilitation places in Dehong Prefecture, Yunnan Province]

Objective: To compare the prevalence of HIV infection and its risk factors among Chinese and Burmese drug users living in Dehong Prefecture, Yunnan Province. Methods: We obtained plasma specimens and gathered demographic data from 7 867 drug users with Chinese or Burmese nationality attending rehabilitation clinics in Dehong Prefecture from October 2014 to September 2015. Of these, 7 756 individuals who gave valid questionnaire responses, including 5 389 Chinese and 2 367 Burmese, were enrolled in the study after giving informed consent. We used the Chi-squared test to compare the demographic characteristics and HIV prevalence between the Chinese and Burmese drug users. Logistic regression was then used to identify risk factors for HIV infection. Results: The HIV infection rate of 7 756 subjects (aged (35.45 ± 10.91) years old) was 7.18%, in which Burmese with higher HIV infection rate (9.38%, 222/2 367) than Chinese (6.22%, 335/5 389) (χ²=24.21, P<0.001). In chinese drug users, OR (95%CI) of HIV infection of those aged 25-34 years old, 35-44 years old and ≥45 years old were 2.88 (1.46-5.69), 5.72 (2.87-11.40) and 3.48 (1.66-7.27),compared with those aged below 25 years;Compared with married participants, OR (95% CI) of those unmarried and divorced were 1.44 (1.08-1.93) and 1.56 (1.09-2.24); Jingpo drug users were 1.47 (1.07-2.04) times to get HIV infection,compared with Han ethnicity; OR (95%CI) of HIV infection for IDUs was 11.48 (9.73-16.01) compared with NIDUs.In Burmese drug users, OR (95% CI) of HIV infection for females was 0.50 (0.26-0.93) compared with men;Compared with those aged below 25 years,those aged 25-34,35-44 and ≥45 years had OR (95% CI) of 1.82 (1.18-2.77), 2.90 (1.82-4.62) and 2.31 (1.24-4.30), respectively; OR (95% CI) of Jingpo participants was 2.22 (1.44-3.41) compared with Han nationality; OR (95%CI) of HIV infection for IDUs was 10.61 (7.68-14.64) compared with NIDUs. Conclusion: The HIV infection rate of Burmese drug users was higher than that of Chinese drug users. Measures of HIV prevention and control should be mainly allocated in those 25 years above, non-married, Jingpo ethnicity and IDU in Chinese drug users, while in Burmese drug users,those females, 25 years above, Jingpo ethnicity and IDU should be higlighted in HIV prevention and control.

[Role of master transcriptional factor Prox-1 in lymphatic endothelial differentiation of Kaposiform hemangioendothelioma]

Objective: To analyze the clinical and pathological features of Kaposiform hemangioendothelioma (KHE), and to investigate the role of master transcriptional factor Prox-1 in the regulation of lymphatic differentiation. Methods: Nine cases of KHE (during the period from October 2009 to June 2016) were collected with clinical and pathological data. H&E stained section review and immunohistochemietry using the Dako EnVision method were performed. Results: There were 6 female and 3 male patients with age ranging from 2 months to 8 years (median 3 years and 4 months). The patients presented with either single subcutaneous soft tissue mass, or bone tumors, with the duration of disease onset ranging from 1 month to 1 year. The sites of involvement included the skins of neck (2 cases), nose root (1 case), inguinal (1 case), thigh root (1 case), humerus (2 cases), lumbar vertebrae(1 case), and mesentery (1 case). These tumors were histologically composed of nodules of densely packed spindle or ovoid cells and deformed small blood vessels in an invasive growth pattern. The tumor cells were immunohistochemically positive for both blood vessels and lymphatic endothelial markers, including Prox-1, the master transcriptional factor, and VEGFR-3. With followed-up from 1 to 60 months (median 26 months), two patients died of the disease, while the remaining patients were alive without recurrence. Conclusions: KHE is a rare vascular tumor with at least partial lymphatic endothelial differentiation, in which Prox-1 may act as a master regulator for such differentiation. KHE is an aggressive tumor of intermediate malignant potential, with local invasion and recurrence tendency, and long term follow-up is required.

[Epithelioid sarcoma with mesothelial and lymphatic endothelial differentiation: a clinicopathologic analysis of 10 cases]

Objective: To investigate the multidirectional differentiation potential in epithelioid sarcoma (ES), with special emphasis on its mesothelial and lymphatic endothelial markers expression. Methods: Ten cases of distal-type ES were included. The clinical, histological, and immunohistochemical(including mesothelial and lymphatic endothelial markers expression)features and follow-up data were evaluated. Results: The patients aged between 8 to 66 years. Five cases were male and five were female. The tumors were located at the palm (2 cases), wrist (3 cases), upper arm (2 cases), poplitealfossa (1 case), lower leg (1 case) and thigh (1 case), respectively. Clinically, most cases presented as painful, firm subcutaneous nodules. Histologically, the tumors were mainly composed of epithelioid, rhabdoid, spindle, or transitional cells, with abundant eosinophilic cytoplasm, oval and vesicular nucleus, and one or more prominent nucleoli. They were arranged in nodular, diffuse nodular or sheet like growth patterns, frequently with necrosis at the center with vague granulomatous configuration. Immunohistochemically, all tumors expressed cytokeratins, epithelial membrane antigen, CD34, desmin, mesothelial markers such as Calretinin, WT1, D2-40, M2A, vascular and lymphatic endothelial markers FLI-1, and VEGFR-3. The tumor cells did not express CD31, FⅧRAg, HHF35, HMB45, Melan A, MyoD1, myogenin, S-100 protein and SMA. All 10 patients underwent radical resection or extended excision, with additional radiotherapy or chemotherapy. During the follow-up from October 2012 to August 2016, seven cases showed recurrences and metastases within 2 months to 2 years. Five patients died of the disease due to widespread metastases. Conclusions: ES may show a wide spectrum of morphology, and display a multidirectional differentiating capabilities including towards mesothelial and lymphatic endothelial cells. As such, its diagnosis and differential diagnosis are particularly important as it is easily confused with other tumors with similar morphology or immune phenotype.

Analysis and comparison of the cost-effectiveness of statins according to the baseline low-density lipoprotein cholesterol level in Korea

WHAT IS KNOWN AND OBJECTIVE

There are a few Korean studies on the economics of statins based on reduction in low-density lipoprotein cholesterol (LDL-C) data from other countries. This study aimed to analyse and compare the cost-effectiveness of statins according to the baseline LDL-C level in Korea.

METHODS

Between January 2009 and December 2015, the data of patients who were prescribed statins for the first time were extracted from electronic medical records. We performed a cost-effectiveness analysis (CEA) based on the LDL-C reduction rate (CEA-RR) and target achievement rate.

RESULTS AND DISCUSSION

Among high-intensity statins, the CEA-RR value of rosuvastatin (20 mg) was significantly lower than that of atorvastatin (40 mg) at all baseline LDL-C levels, except levels of 160-189 mg/dL. Additionally, at baseline LDL-C levels of 130-159 mg/dL, the CEA-RR value of rosuvastatin (20 mg) was three times lower than that of atorvastatin (40 mg) (9·1 ± 2·5 $/% vs. 31·7 ± 15·0 $/%, P < 0·001). Among moderate-to-low-intensity statins, rosuvastatin (5 mg) showed the lowest CEA-RR value (4·0 ± 0·6 $/%), and the value significantly increased for pitavastatin (2 mg) (8·0 ± 0·6 $/%), atorvastatin (10 mg) (9·5 ± 0·5 $/%), simvastatin (10·8 ± 1·1 $/%) and pravastatin (40 mg) (11·5 ± 0·9 $/%) in order (P < 0·0001). On changing from atorvastatin (10 mg) to atorvastatin (20 mg), the additional yearly cost was 16·0 and additional CEA-RR value was 2·74 $/%. On the other hand, on changing from atorvastatin (10 mg) to rosuvastatin (10 mg), the additional yearly cost was -16·3 and additional CEA-RR value was -1·8 $/%.

WHAT IS NEW AND CONCLUSION

We successfully compared the cost-effectiveness of statins according to the baseline LDL-C level in Korea. It is expected that our findings will help clinical decision-making with regard to statin prescription, and this will help reduce national medical expenditure.

Phenotypic and genotypic correlates of daptomycin-resistant methicillin-susceptible Staphylococcus aureus clinical isolates

Daptomycin (DAP) has potent activity in vitro and in vivo against both methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) strains. DAP-resistance (DAP-R) in S. aureus has been mainly observed in MRSA strains, and has been linked to single nucleotide polymorphisms (SNPs) within the mprF gene leading to altered cell membrane (CM) phospholipid (PL) profiles, enhanced positive surface charge, and changes in CM fluidity. The current study was designed to delineate whether these same genotypic and phenotypic perturbations are demonstrated in clinically-derived DAP-R MSSA strains. We used three isogenic DAP-susceptible (DAP-S)/DAP-R strainpairs and compared: (i) presence of mprF SNPs, (ii) temporal expression profiles of the two key determinants (mprF and dltABCD) of net positive surface charge, (iii) increased production of mprF-dependent lysinylated-phosphatidylglycerol (L-PG), (iv) positive surface charge assays, and (v) susceptibility to cationic host defense peptides (HDPs) of neutrophil and platelet origins. Similar to prior data in MRSA, DAP-R (vs DAP-S) MSSA strains exhibited hallmark hot-spot SNPs in mprF, enhanced and dysregulated expression of both mprF and dltA, L-PG overproduction, HDP resistance and enhanced positive surface charge profiles. However, in contrast to most DAP-R MRSA strains, there were no changes in CM fluidity seen. Thus, charge repulsion via mprF-and dlt-mediated enhancement of positive surface charge may be the main mechanism to explain DAP-R in MSSA strains.

[Estimation on the HIV-1 incidence in Liangshan Yi Autonomous Prefecture, under BED-capture enzyme immunoassay, from 2011 to 2013]

OBJECTIVE

This paper aimed to analyze the situation of HIV infection in Liangshan Yi Autonomous, including HIV recent rate of infection and the ongoing strategies on prevention of the disease in this prefecture.

METHODS

Surveillance data on population size, medical institutions, from 2011 to 2013 in Liangshan prefecture was collected. The total numbers of people living in the areas appeared as 412 608, 393 699 and 443 025 from the above mentioned three years. The overall numbers of people living with HIV/AIDS were 4 480, 3 999 and 4 719 respectively in the three years of observation, using the ELISA and WB blot. We also used the ELISA, and Western blotting methods to find out the HIV-positive individuals. We then applied the ' BED HIV-1 incidence capture enzyme immunoassay (BED-CEIA)' on these HIV-positive individuals to locate those who were recently infected, to estimate the annual recent infection rates.

RESULTS

The HIV-positive rates in Liangshan Prefecture appeared as 1.09%, 1.02% and 1.07% respectively, from 2011 to 2013, with the recent infection rates as 0.34% (95%CI: 0.32-0.37), 0.62% (95%CI: 0.58-0.66) and 0.61% (95%CI: 0.57-0.65) respectively. The newly infections mainly involved with males, with Yi ethnicity, married, being illiterate or received primary school education. In males, the rates of infection appeared as 64.24% (433/674), 59.22% (504/851) and 58.37% (495/848) respectively, in the three years of observation among people with Yi ethnicity, the recent infection rates were 84.72% (571/674) in 2011, 94.59% (805/851) in 2012 and 84.20% (714/848) in 2013. The rates seen in married people were 61.57% (415/674), 61.45% (523/851) and 60.50% (513/848) respectively. Among the illiterates or people only received primary school education, the rates appeared as 60.24% (406/674) in 2011, 61.57% (524/851) in 2012, and 60.03% (509/848) in 2013.

CONCLUSION

Using the HIV recent infection rate to describe the situation of AIDS in Liangshan prefecture, figures seemed to be more reliable than under the regular HIV-positive rate.

Liquid Supercoolability and Synthesis Kinetics of Quinary Refractory High-entropy Alloy

The high-entropy configuration of equiatomic multicomponent alloys opens an effective access to the development of advanced materials. Here we report the synthesis of a new quinary refractory WMoTaNbZr high-entropy alloy under electrostatic levitation condition. It showed a high liquidus temperature of 2686 K and achieved a maximum supercooling of 640 K (0.24 T_L) at molten state. The containerless measurements revealed a linear increasing tendency for both its liquid state density and the specific heat to emissivity ratio versus alloy supercooling. A high-entropy body-centered cubic (HEB) phase dominated its phase constitution despite the formation of a negligible amount of solid solution (Zr) phase. The dendritic growth of HEB phase always governed the crystallization process, attained a fastest growth velocity of 13.5 m/s and displayed a power function relation to alloy supercooling. The high speed videographic research of recalescence phenomenon indicated Johnson-Mehl-Avrami type transition kinetics for its rapid solidification process. As supercooling increases, the microstructures of primary HEB phase were refined conspicuously and exhibited an obvious solute trapping effect of the segregative Zr component. Meanwhile, the Vickers hardness of HEB phase displayed the rising tendency with supercooling.

Transformation and utilization of slowly biodegradable organic matters in biological sewage treatment of anaerobic anoxic oxic systems

This study examined the distribution of carbon sources in two anaerobic anoxic oxic (AAO) sewage treatment plants in Xi'an and investigated the transformation characteristics and utilization potential of slowly biodegradable organic matters (SBOM). Results indicated under anaerobic and aerobic conditions, SBOM could be transformed at a rate of 65% in 8h into more readily biologically utilizable substrates such as volatile fatty acids (VFAs), polysaccharides and proteins. Additionally, non-biodegradable humus-type substances which are difficult to biodegrade and readily accumulate, were also generated. These products could be further hydrolyzed to aldehyde and ketone compounds and then transformed into substances with significant oxygen-containing functional groups and utilized subsequently. The molecular weights of proteinoid substances had a wide distribution and tended to decrease over time. Long hours of microbial reaction increased the proportion of micromolecular substances. This particular increase generated significant bioavailability, which can greatly improve the efficiency of nitrogen removal.

Comparative analysis of the efficacy of omega-3 fatty acids for hypertriglyceridaemia management in Korea

WHAT IS KNOWN AND OBJECTIVE

This study aimed to compare the ability of statin monotherapy (ST group), omega-3 fatty acid monotherapy (OM_A group) and combination therapy with omega-3 fatty acids and a statin (OM_S group), to reduce triglyceride (TG) levels in patients with hypertriglyceridaemia.

METHODS

In this retrospective cohort study, we extracted data from the electronic medical records of patients initially prescribed either a statin or omega-3 fatty acids between January, 2009 and December, 2013. We performed a comparative analysis of the change in cholesterol levels between baseline and an average of 3 months later.

RESULTS AND DISCUSSION

Data were extracted for 2071 patients. The average daily eicosapentaenoic acid (EPA) ethyl ester and docosahexaenoic acid (DHA) ethyl ester intake was 1689 mg, and 79-86% of the OM_A and OM_S groups were prescribed two omega-3 fatty acid capsules. At a baseline TG level of between 200 and 500 mg/dL, TG levels were reduced by 16 ± 2·8% in the ST group, 28 ± 2·8% in the OM_A group and 29 ± 2·3% in the OM_S group (P = 0·001 for ST group vs. OM_A and OM_S groups), with no difference between the OM_A and OM_S groups. At a baseline TG level ≥500 mg/dL, there was no difference in TG level reduction between the three groups (54 ± 7·3%, 55·8 ± 3·5% and 51·8 ± 6·8%, respectively, P = 0·851).

WHAT IS NEW AND CONCLUSION

Although omega-3 fatty acids are not considered the primary medication for hypertriglyceridaemia, the prescription of omega-3 fatty acids is justifiable if reduction in TG levels is judged to be necessary.

Antimicrobial resistance and virulence profiles of Enterococcus spp. isolated from horses in korea

Antimicrobial-resistant (AR) enterococci have emerged as leading nosocomial pathogens. Transmission of AR Enterococci from animals to humans has been demonstrated. However, there is limited information on the transmission of enterococci from horses to humans. To address this issue, we characterized 260 enterococci isolated from horse-associated samples in Korea in 2013 based on their AR profiles and virulence traits. AR profiling revealed an average ratio of AR enterococci of 23.8%. Seven isolates (2.7%) were multidrug-resistant Enterococcus faecalis. Most tetracycline-resistant enterococci harbored either tetM or tetL or both genes; genes conferring resistance to other antimicrobials were detected at low rates. Biofilm formation and gelatinase activity were observed in 51.1% and 47.7% of isolates, respectively; most were E. faecalis harboring the gelE gene. Evidence of transmission of AR enterococci between horses and their environments was provided by pulsed-field gel electrophoresis, and highlights the risk of AR enterococcus transmission to horse riders and handlers through close contact.

Current status of urban wastewater treatment plants in China

The study reported and analyzed the current state of wastewater treatment plants (WWTPs) in urban China from the perspective of treatment technologies, pollutant removals, operating load and effluent discharge standards. By the end of 2013, 3508 WWTPs have been built in 31 provinces and cities in China with a total treatment capacity of 1.48×10(8)m(3)/d. The uneven population distribution between China's east and west regions has resulted in notably different economic development outcomes. The technologies mostly used in WWTPs are AAO and oxidation ditch, which account for over 50% of the existing WWTPs. According to statistics, the efficiencies of COD and NH3-N removal are good in 656 WWTPs in 70 cities. The overall average COD removal is over 88% with few regional differences. The average removal efficiency of NH3-N is up to 80%. Large differences exist between the operating loads applied in different WWTPs. The average operating loading rate is approximately 83%, and 52% of WWTPs operate at loadings of <80%, treating up to 40% of the wastewater generated. The implementation of discharge standards has been low. Approximately 28% of WWTPs that achieved the Grade I-A Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002) were constructed after 2010. The sludge treatment and recycling rates are only 25%, and approximately 15% of wastewater is inefficiently treated. Approximately 60% of WWTPs have capacities of 1×10(4)m(3)/d-5×10(4)m(3)/d. Relatively high energy consumption is required for small-scale processing, and the utilization rate of recycled wastewater is low. The challenges of WWTPs are discussed with the aim of developing rational criteria and appropriate technologies for water recycling. Suggestions regarding potential technical and administrative measures are provided.

Dysregulation of mprF and dltABCD expression among daptomycin-non-susceptible MRSA clinical isolates

BACKGROUND

In small series or individual reports, SNPs within the mprF ORF and dysregulation of its expression in Staphylococcus aureus have been linked to daptomycin resistance (DAP-R) via a proposed gain-in-function mechanism. Similarly, dysregulation of dltABCD has also been associated with DAP-R.

METHODS

Using 22 well-characterized, isogenic daptomycin-susceptible (DAP-S)/DAP-R clinical MRSA strain pairs, we assessed potential relationships of the DAP-R phenotype with: (i) regulation of mprF transcription; (ii) regulation of dltABCD transcription; (iii) expression of the two-component regulatory system, graRS (upstream regulator for both mprF and dltABCD transcription); (iv) SNPs within the graRS promoter or its ORF; and (v) altered mprF transcription and lysyl-phosphatidylglycerol (L-PG) synthesis.

RESULTS

Enhanced expression of mprF occurred with SNPs in highly distinct and well-chronicled MprF domain 'hot spots' and rarely occurred without such mutations. Increased expression and/or dysregulation of mprF and dltABCD were not uncommon in DAP-R strains, occurring in 27% of strains for each gene. In these latter strains, neither graRS expression profiles nor polymorphic sequences within the graRS promoter or ORF could be significantly linked to altered transcription of mprF or dlt.

CONCLUSIONS

Although graRS can co-regulate mprF and dltABCD expression, loci outside of this regulon appear to be involved in dysregulation of these latter two genes and the DAP-R phenotype. Finally, DAP-R strains exhibiting significantly altered mprF transcription profiles produced significantly increased levels of L-PG.

Toll/IL-1 domain-containing adaptor inducing IFN-β (TRIF) mediates innate immune responses in murine peritoneal mesothelial cells through TLR3 and TLR4 stimulation

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TRIF is involved in cytokines and chemokines production by poly I:C and LPS in PMCs.

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TRIF mediates iNOS expression and NO production by poly I:C or LPS in PMCs.

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TRIF is required for IFN-β gene expression in PMCs stimulated by poly I:C or LPS.

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TRIF is essential for optimal production of IL-6, CXCL1, and CCL2 by live G-bacteria.

Mesothelial cells are composed of monolayer of the entire surface of serosal cavities including pleural, pericardial, and peritoneal cavity. Although mesothelial cells are known to express multiple Toll-like receptors (TLRs) which contribute to trigger innate immune responses against infections, the precise molecular mechanism remains still unclear. In the present study, we investigated the role of Toll/IL-1 domain-containing adaptor inducing IFN-β (TRIF), one of the two major TLRs–adaptor molecules, on innate immune response induced by TLR3 and TLR4 stimulation in murine peritoneal mesothelial cells (PMCs). TRIF was strongly expressed in PMCs and its deficiency led to impaired production of cytokines and chemokines by poly I:C and LPS in the cells. Activation of NF-κB or MAPKs through poly I:C and LPS stimulation was reduced in TRIF-deficient PMCs as compared to the WT cells. TRIF was also necessary for optimal nitric oxide synthesis and gene expression of inducible nitric oxide synthase (iNOS) and IFN-β in PMCs in response to poly I:C and LPS. Furthermore, both Escherichia coli and Pseudomonas aeruginosa induced high level of IL-6, CXCL1, and CCL2 production in PMCs, which was significantly impaired by TRIF deficiency. These results demonstrated that TRIF is required for optimal activation of innate immune responses in mesothelial cells against microbial infections.

The role of Staphylococcal carotenogenesis in resistance to host defense peptides and in vivo virulence in experimental endocarditis model

The defining hallmark of the newly described species, Staphylococcus argenteus, in comparison to its sister species, S. aureus and S. schweitzeri, is the absence of production of the carotenoid pigment, staphyloxanthin. Staphylococcus argenteus lacks the responsible genetic locus crtOPQMN. We examined the impact of carotenoid synthesis in two non-pigmented S. argenteus strains, MSHR1132 and SCC1165. Following complementation with a plasmid containing the carotenoid operon (pTX-crtOPQMN), compared to wild type, both complemented strains showed substantial carotenoid production, with a resultant increase in cell membrane rigidity. Surprisingly, both crtOPQMN-complemented strains exhibited increased susceptibility to the host defense peptides, LL-37 and hNP-1 in vitro, and reduced virulence in an experimental rabbit endocarditis model.

Zhi-Long-Huo-Xue-Tong-Yu modulates mitochondrial fission through the ROCK1 pathway in mitochondrial dysfunction caused by streptozotocin-induced diabetic kidney injury

Zhi-Long-Huo-Xue-Tong-Yu (ZLHXTY) is a defined mixture of 5 herbs developed by Professor S.J. Yang according to the Buyang Huanwu decoction method, which has been recorded in the Yilingaicuo. This study investigated the renoprotective effects of ZLHXTY on mitochondrial dysfunction induced by diabetic kidney injury in a diabetic rat model. Diabetes was induced by a single intravenous injection of streptozotocin. Rats were daily fed either ZLHXTY or vehicle beginning in the 1st week after injection. Levels of mitofusin 2 (mfn2), dynamin-related protein 1 (Drp1), caspase-9, and rho-associated, coiled-coil-containing protein kinase 1 (ROCK1) were detected using Western blotting. Levels of intracellular calcium and adenosine triphosphate (ATP) were examined using an enzyme-linked immunosorbent assay. An electron microscopic examination of kidney tissue was performed. The levels of mfn2 and ATP in the diabetes and ZLHXTY groups decreased from the 4th week after modeling. The expression levels of Drp1, ROCK1, and caspase-9 increased in the diabetes group but decreased in the ZLHXTY group from the 4th week after modeling. Compared with the diabetes group, ZLHXTY treatment decreased the mesangial expansion index and proteinuria levels, and improved the pathological changes typical of diabetic kidney injury. Furthermore, ZLHXTY treatment inhibited the activation of ROCK1 and expression of Drp1 and caspase-9, but did not affect the expression of mfn2. This study indicates that ZLHXTY treatment could protect kidney tissue from diabetic injury through the ROCK1 pathway response to mitochondrial dysfunction induced by diabetes.

Phenotypic and genotypic characterization of daptomycin-resistant methicillin-resistant Staphylococcus aureus strains: relative roles of mprF and dlt operons

Development of in vivo daptomycin resistance (DAP-R) among Staphylococcus aureus clinical isolates, in association with clinical treatment failures, has become a major therapeutic problem. This issue is especially relevant to methicillin-resistant S. aureus (MRSA) strains in the context of invasive endovascular infections. In the current study, we used three well-characterized and clinically-derived DAP-susceptible (DAP-S) vs. resistant (DAP-R) MRSA strain-pairs to elucidate potential genotypic mechanisms of the DAP-R phenotype. In comparison to the DAP-S parental strains, DAP-R isolates demonstrated (i) altered expression of two key determinants of net positive surface charge, either during exponential or stationary growth phases (i.e., dysregulation of dltA and mprF), (ii) a significant increase in the D-alanylated wall teichoic acid (WTA) content in DAP-R strains, reflecting DltA gain-in-function; (iii) heightened elaboration of lysinylated-phosphatidylglyderol (L-PG) in DAP-R strains, reflecting MprF gain-in-function; (iv) increased cell membrane (CM) fluidity, and (v) significantly reduced susceptibility to prototypic cationic host defense peptides of platelet and leukocyte origins. In the tested DAP-R strains, genes conferring positive surface charge were dysregulated, and their functionality altered. However, there were no correlations between relative surface positive charge or cell wall thickness and the observed DAP-R phenotype. Thus, charge repulsion mechanisms via altered surface charge may not be sufficient to explain the DAP-R outcome. Instead, changes in the compositional or biophysical order of the DAP CM target of such DAP-R strains (i.e., increased fluidity) may be essential to this phenotype. Taken together, DAP-R in S. aureus appears to involve multi-factorial and strain-specific adaptive mechanisms.

Association of GSTTI and GSTM1 variants with acute myeloid leukemia risk

We aimed to investigate the relationships between polymorphisms of the glutathione S-transferases (GSTs) GSTM1, GSTTI, and GSTP1 and the risk of developing acute myeloid leukemia (AML). A total of 206 AML cases and 231 controls were collected for our study. The genotyping of GSTs (GSTM1, GSTTI, and GSTP1) was based upon the duplex polymerase chain reaction with the confronting two-pair primer (PCR-CTPP) method. Individuals carrying null GSTTI and GSTM1 genotypes had a 1.52- and 1.78-fold increased risk of developing acute leukemia, respectively, compared to non-null genotype carriers (P < 0.05). A high risk was observed in those carrying a combination of null genotypes of GSTM1 and GSTTI with GSTP1-Val allele genotypes when compared with those carrying wild-type genotypes, with an odds ratio (95% confidence interval) of 3.62 (1.53-8.82) (P < 0.05). These findings indicate that genetic variants of GSTTI and GSTM1 significantly increase the risk of developing AML. Our study offers important insights into the molecular etiology of AML.

Relationship between the acylation-stimulating protein gene and coronary heart disease in the Xinjiang Uygur and Han populations of China

The association of the single nucleotide polymorphism 301T>C in the coding region of the acylation-stimulating protein (ASP) gene with coronary heart disease (CHD) was investigated in the Uygur (385 CHD patients and 483 control subjects) and Han (390 CHD patients and 439 control subjects) populations of China. The frequency of the CC and CT genotypes was significantly higher in patients with CHD compared to the control group (55.3 vs 46.2%, P = 0.001) in the Uygur population, but in the Han population, the frequency was significantly higher in the control group (51.7 vs 24.4%, P < 0.001). In addition, the C allele was significantly associated with CHD in the Uygur population (C allele: 33.8 vs 26.2%, T allele: 66.2 vs 73.8%; P = 0.004) and in the Han population (C allele: 14.5 vs 30.3%, T allele: 85.5 vs 69.7%; P < 0.001). The CC genotype was independently associated with increased risk of coronary artery disease when adjusted for other cardiovascular risk factors [odds ratio (OR) = 2.189, 95% confidence interval (CI) = 1.251-3.830, P = 0.001] in the Uygur population, but was a protective factor for CHD in the Han population (OR = 0.373, 95%CI = 0.187-0.745, P = 0.005). In conclusion, the 301T>C polymorphism of the ASP gene that influences the serum triglycerides level in the Uygur population, is associated with the development of CHD, and the CC genotype might be a risk factor of CHD.

Emergence of daptomycin resistance in daptomycin-naïve rabbits with methicillin-resistant Staphylococcus aureus prosthetic joint infection is associated with resistance to host defense cationic peptides and mprF polymorphisms

Background

Previous studies of both clinically-derived and in vitro passage-derived daptomycin–resistant (DAP-R) Staphylococcus aureus strains demonstrated the coincident emergence of increased DAP MICs and resistance to host defense cationic peptides (HDP-R).

Methods

In the present investigation, we studied a parental DAP-susceptible (DAP-S) methicillin-resistant Staphylococcus aureus (MRSA) strain and three isogenic variants with increased DAP MICs which were isolated from both DAP-treated and DAP-untreated rabbits with prosthetic joint infections. These strains were compared for: in vitro susceptibility to distinct HDPs differing in size, structure, and origin; i.e.; thrombin-induced platelet microbicidal proteins [tPMPs] and human neutrophil peptide-1 [hNP-1]; cell membrane (CM) phospholipid and fatty acid content; CM order; envelope surface charge; cell wall thickness; and mprF single nucleotide polymorphisms (SNPs) and expression profiles.

Results

In comparison with the parental strain, both DAP-exposed and DAP-naive strains exhibited: (i) significantly reduced susceptibility to each HDP (P<0.05); (ii) thicker cell walls (P<0.05); (iii) increased synthesis of CM lysyl-phosphatidylglycerol (L-PG); (iv) reduced content of CM phosphatidylglycerol (PG); and (v) SNPs within the mprF locus No significant differences were observed between parental or variant strains in outer CM content of L-PG, CM fluidity, CM fatty acid contents, surface charge, mprF expression profiles or MprF protein content. An isolate which underwent identical in vivo passage, but without evolving increased DAP MICs, retained parental phenotypes and genotype.

Conclusions

These results suggest: i) DAP MIC increases may occur in the absence of DAP exposures in vivo and may be triggered by organism exposure to endogenous HDPs: and ii) gain-in-function SNPs in mprF may contribute to such HDP-DAP cross-resistance phenotypes, although the mechanism of this relationship remains to be defined.