Racial/ethnic disparities in exposure to e-cigarette advertising among U.S. youth.

OBJECTIVES: This study aims to assess exposure to e-cigarette advertising across multiple marketing channels among U.S. youth and to examine whether racial/ethnic disparities exist in exposure to e-cigarette advertisements. STUDY DESIGN: This is a cross-sectional study. METHODS: Cross-sectional data were drawn from a longitudinal survey of participants recruited from two nationally representative panels (NORC's AmeriSpeak® and GfK's KnowledgePanel). A total of 2043 youth aged 13-17 completed the initial 2018 survey, and 2013 youth completed the follow-up survey in 2019 (including a replenishment sample of 690 youth). Outcome variables were self-reported e-cigarette advertisement exposure in the past three months through various sources, such as television, point of sale, and online/social media. Generalized estimating equation models were used to estimate the adjusted odds ratios (AOR) of the association between racial/ethnic identity and e-cigarette advertisement exposure. RESULTS: The prevalence of reported exposure to e-cigarette advertisements through any channel was 79.8% (95% CI: 77.1-82.2) in 2018 and 74.9% (95% CI: 72.5-77.1) in 2019, respectively. Point of sale was the most common source of e-cigarette advertisement exposure in both years. Non-Hispanic Black and non-Hispanic Asian youth were more likely to report exposure to e-cigarette advertisements through television (AOR = 2.07, 95% CI: 1.44-2.99 and AOR = 2.11, 95% CI: 1.17-3.82, respectively) and online/social media (AOR = 1.61; 95% CI: 1.11-2.33 and AOR = 1.99, 95% CI: 1.10-3.59, respectively) channels compared with non-Hispanic White youth. CONCLUSIONS: A substantial proportion of U.S. youth reported exposure to e-cigarette advertising through a variety of marketing channels. Significant racial/ethnic disparities existed, with non-Hispanic Black and Asian youth reporting more marketing exposure than their non-Hispanic White counterparts.

Dexamethasone relieves the inflammatory response caused by inguinal hernia meshes through miR-155.

BACKGROUND: Inguinal hernia is a relatively common condition. Most patients with inguinal hernia require surgery. At present, mesh repair is one of the most effective methods to treat inguinal hernia, but insertion of the mesh can cause inflammation. Dexamethasone (DEX) can treat inflammation, but the mechanism by which DEX alleviates inflammation caused by inguinal hernia mesh placement remains unclear. METHOD: We randomly divided rats into groups: negative control (NC), inguinal hernia (IH), polypropylene mesh (PM), DEX treatment, and miR-155 treatment groups. RT-qPCR was performed to determine the expression of miR-155. ELISA was implemented to determine the secretion of IL-1ß, IL-6, and IL-18. Western blotting was used to detect caspase-1, JAK1, p-JAK1, STAT3, and p-STAT3 expression. A dual-luciferase reporter gene array identified a connection between miR-155 and JAK1. RESULTS: The results revealed that the expression of miR-155, IL-1ß, IL-6, and IL-18 was upregulated in the PM group. After DEX treatment, the secretion of miR-155, caspase-1, IL-1ß, IL-6, and IL-18 decreased. Dual luciferase results confirmed that miR-155 induced the targeted downregulation of JAK1, while a miR-155 mimic reversed the therapeutic effect of DEX, and the expression levels of p-JAK1 and p-STAT3 increased. CONCLUSION: DEX regulates the JAK1/STAT3 signaling pathway through miR-155 to relieve inflammation caused by inguinal hernia meshes.

[Progress of lung organoids in lung epithelial repair and regenerative medicine].

The mechanical barrier of lung is made up of epithelial cells which participate in gas exchange. Some of these cells have stem cell potential and are known as lung epithelial stem cells. They play an important role in maintaining lung homeostasis and repairing injured epithelial cells. Organoids are derived from pluripotent stem cells or adult stem cells cultured in a three-dimensional manner in vitro. Their structure and function are very similar to original tissues or organs. They can also self-renew, proliferate, and differentiate. Lung organoids can simulate the structure and function of epithelial cells in vitro. They provide an ideal model for the study of lung epithelial stem cells, which repair epithelial cells in vitro. Meanwhile, they provide an ideal graft for regenerative medicine. Around the lung organoids, this review concludes the mechanisms involved in lung epithelial stem cells repairing epithelial cells, summarizes their applications in regenerative medicine, and provides related reference for the therapy of lung diseases.

[Progress in the effect of human epididymis protein 4 on sperm maturation].

Human epididymis protein 4(HE4) is a secretory glycoprotein found in human distal epididymis epithelial cells. It is often used in the early diagnosis, efficacy evaluation and monitoring of ovarian cancer, and also has been considered as an effective serum marker for many other types of cancer. However, its function in the process of sperm maturation is not fully unknown. The maturation of sperm in epididymis is characterized by the acquisition of motility and fertilization. As a member of the whey acid protein (WAP) family, several studies proposed the importance of HE4 in the maturity of sperm in epididymis. This article reviews the effect of HE4 on spermatozoa maturation in epididymis, which provides basis for the evaluation of male reproductive ability, early detection, early diagnosis and pathogenesis of male infertility.

[Related factors for microalbuminuria in adult type 1 diabetes patients of short disease duration].

Objective: To investigate related factors for microalbuminuria in adult type 1 diabetes (T1D) patients of short disease duration (less than 5 years), and provide evidence for prevention of early diabetic kidney disease in this population. Methods: All adult patients enrolled in the Guangdong T1D translational medicine study between 2011 and 2017 with a disease duration of less than 5 years were included in this analysis. At enrollment, patients' demographic and clinical data were documented, and blood and urine samples were collected for the measurements of blood lipids, glycated hemoglobin A1c and urine albuminuria. Insulin resistance was evaluated by estimated glucose disposal rate (eGDR). Patients were categorized into groups based on urine albumin creatitine ratio (UACR): normoalbuminuric group (UACR<30 mg/g) and microalbuminuric group (UACR≥30 mg/g). Stepwise multivariate linear regression analysis was used to analyze risk factors for microalbuminuria in adult T1D patients of short disease duration. Results: A total of 384 patients were included in this analysis, and 51.3% (197/384) of which was female. The onset age of patients was (24.6±12.5) years, with a disease duration of 2.1(0.6, 3.5) years, body mass index of (19.8±3.2) kg/m(2), waist hip ratio of 0.85±0.21, and glycated hemoglobin A1c of (9.8±3.3)% at enrollment. Microalbuminuria occurred in 62 patients (16.1%). Multivariate linear analysis showed that higher glycated hemoglobin A1c, higher systolic blood pressure and more severe insulin resistance were related factors for microalbuminuria (t=2.322, 2.868 and -2.373, respectively, all P<0.05). Conclusions: Microalbuminuria was not rare in adult T1D patients of short disease duration. Inadequate glycemic control and insulin resistance were independent related factors for microalbuminuria in this population.

CNDP2 Acts as an Activator for Human Ovarian Cancer Growth and Metastasis via the PI3K/AKT Pathway.

INTRODUCTION: The mechanism of tumorigenesis and metastasis of ovarian cancer has not yet been elucidated. This study aimed to investigate the role and molecular mechanism of cytosolic nonspecific dipeptidase 2 in tumorigenesis and metastasis. METHODS: Cytosolic nonspecific dipeptidase 2 expression in human ovarian cancer tissues and cell lines was assessed with methyl thiazolyl tetrazolium (MTT), clone formation, and transwell assays performed to evaluate the ability of ovarian cancer cells to proliferate and migrate. Nude mice tumor formation experiments were also performed by subcutaneously injecting cells with stable cytosolic nonspecific dipeptidase 2 knockdown and control SKOV3 cells into BALB/c female nude mice to detect changes in PI3K/AKT pathway-related proteins by Western blotting. RESULTS: Cytosolic nonspecific dipeptidase 2 was highly expressed in human ovarian cancer tissues, with its expression associated with pathological data, including ovarian cancer metastasis. A cytosolic nonspecific dipeptidase 2 stable knockdown or ectopic expression ovarian cancer cell model was established and demonstrated that cytosolic nonspecific dipeptidase 2 could promote the proliferation of ovarian cancer cells. Transwell cell migration and invasion assays confirmed that cytosolic nonspecific dipeptidase 2 enhanced cell metastasis in ovarian cancer. Furthermore, in vivo xenograft experiments demonstrated that cytosolic nonspecific dipeptidase 2 can promote the development and progression of ovarian cancer, increasing the expression of phosphorylated PI3K and AKT. CONCLUSIONS: Cytosolic nonspecific dipeptidase 2 promotes the occurrence and development of ovarian cancer through the PI3K/AKT signaling pathway.

[Awareness of preconceptional care and its related factors in women of child-bearing age with type 1 diabetes].

Objective: To investigate the awareness of preconception care among women of child-bearing age with type 1 diabetes (T1DM) and their self-management status, in order to provide evidence for establishment of management pathway for women with T1DM in pregnancy in China. Methods: This cross-sectional survey recruited female participants of child-bearing age from the cohort of Guangdong Type 1 Diabetes Translational Medicine Study conducted between June 2011 and December 2017. The participants were asked to fill out a questionnaire on the awareness of preconception care, their frequency of self-monitoring of blood glucose (SMBG) and other related variables. Chi-squared test or chi-squared test for trend was used in comparisons of categorical variables, and logistic regression analysis was performed to assess associated factors. Results: Totally, 441 women of child-bearing age with T1DM were investigated. The results show that their awareness of preconception care was poor (15.42%, 68/441). Higher educational level (χ(2trend)=3.990, P=0.046), experience of post-diabetes education evaluation (P<0.001), and better coverage of different modules in diabetes education (survival skills: χ(2)=7.525, P=0.004; basic knowledge: χ(2)=8.598, P=0.002; advanced knowledge: P<0.001) were associated with better awareness of preconception care. The average frequency of SMBG in these participants was 0.29 (0.14, 2.00) times per day, and only 8.5% (37/435) of them reached the frequency (≥4 times per day) recommended by guidelines. Moreover, 21.1% (92/435) of them hardly ever performed SMBG. Conclusion: Child-bearing age women with T1DM in Gunangdong had poor awareness of preconception care, with a much lower SMBG frequency than recommendation.

[Association of insulin resistance with dyslipidemia in adults with type 1 diabetes].

Objective: To investigate the relationship between insulin resistance (IR) and dyslipidemia in adults with type 1 diabetes (T1DM) and provide more insights on diabetes-related cardiovascular disease management. Methods: A cross-sectional study recruiting patients from Guangdong T1DM Translational Study cohort was conducted between 2011 and 2017. The patients aged ≥18 years, with a diabetes duration of ≥1 year were enrolled in the study. Plasma lipid profile data of eligible patients, including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were collected and their relationships with insulin resistance were analyzed. IR in these adults with T1DM was estimated by glucose disposal rate (eGDR) calculated by a model published previously. Patients with eGDR lower than 25 percentiles were grouped as severe IR, otherwise non-severe IR. Results: In total, 499 eligible patients were studied, among which 274 were women (54.9%). The level of eGDR was 8.43 (6.11, 10.63) mg kg(-1) min(-1) and the overall incidence of lipid disorders was 65.3% (326/499) in the study population. The result showed that eGDR was correlated with TC, TG, HDL-C and LDL-C (r=-0.163, -0.303, 0.170 and -0.150, respectively, all P<0.05). After adjusting for gender, age and diabetes duration, eGDR was still associated with TG, TC and LDL-C (all P<0.05). Stepwise multiple linear regression analysis showed that gender (female), elevated TC and declined HDL-C were independent factors associated with the severity of IR (t=5.651, 5.823 and 2.908, respectively, all P<0.05). Conclusions: IR is associated with dyslipidemiain in adults with T1DM. Elevated TC and decreased HDL-C are independent associated factors for insulin resistance.

[Glycemic control and its associated factors in children and adolescents with type 1 diabetes mellitus].

Objective: To explore the factors associated with glycemic control in children and adolescents with type 1 diabetes mellitus (T1DM) treated with continuous subcutaneous insulin infusion (CSII). Methods: Subjects were enrolled from the Guangdong Type 1 Diabetes Translational Medicine Study between June 2011 and August 2017. Patients with T1DM aged less than 18 years and treated with CSII for at least 6 months were included. Demographic data and clinical information on self-monitoring of blood glucose (SMBG), glycosylated hemoglobin (HbA1c) and insulin treatment were collected. Participants were categorized based on HbA1c levels as sufficient control group (HbA1c<7.5% ) and insufficient control group ( HbA1c≥7.5%). A multivariate logistic regression model was used to examine the factors associated with glycemic control. Results: A total of 142 participants (76 females, 66 males) with a median age of 13.0 (9.9, 15.0) years and a median disease duration of 3.0 (1.6, 5.0) years were enrolled. HbA1c was (8.2±2.0)% and 41.55%(59/142) of patients achieved the target for HbA1c. The frequency of SMBG was 5.0 (2.0, 8.0) and 3.0 (1.0, 4.0) tests per day (P<0.001), and the frequency of hypoglycemia was 2.0 (0.8, 4.0) and 1.0 (0, 2.0) times per week (P=0.003) in sufficient control group and insufficient control group, respectively. Sufficient glycemic control (HbA1c <7.5%) was associated with the frequency of SMBG (OR=1.238, 95% CI: 1.088-1.409, P=0.001). Conclusion: A higher frequency of SMBG is one of the key factors to achieve sufficient glycemic control among children and adolescents with T1DM treated with CSII.

Successful Vitrification of In vivo Embryos Collected from Superovulated Japanese Black Cattle (Wagyu).

The aim of this study was to determine whether vitrification is an effective method when used for Japanese Black Cattle (Wagyu) in vivo-derived embryos, collected following a superovulation treatment and embryo transfer (MOET) programme. In vivo-derived morula and blastocysts collected on day 7 after artificial insemination, were vitrified using a modified droplet vitrification (MDV) procedure and subsequently warmed for transfer (ET) into synchronized recipients. Fresh embryos, and embryos cryopreserved using a standardized slow freezing procedure (direct thaw/direct transfer, DT) served as ET controls. Two different follicle-stimulating hormone (FSH) sources, Folltropin(®) Canada (FSH BAH, 24 donors) and a brand prepared by the Chinese Academy of Science (FSH CAS, 16 donors), were compared in a series of superovulation outcomes following well-established FSH administration protocols. Following data analysis, the total number of ovulations recorded at the time of embryo flushing (10.5 vs 8.5; p = 0.28) and the total number of transferable embryos (6.2 vs 5.1; p = 0.52) were similar between the two FSH sources. ET for MDV (39.7%, n = 78), DT (35.2%, n = 71) and fresh controls (47.1%, n = 34) resulted in similar pregnancy rates (p > 0.05). When MDV was used, a higher pregnancy rate (42.6%) resulted from the transfer of vitrified morulae, when compared to the DT counterparts (24.3%), (p = 0.05). Transfer of vitrified morulae resulted also in higher pregnancy rate, when compared to the transfer of vitrified blastocysts (42.6% vs. 29.4%; p < 0.05). Transfer of DT blastocysts resulted in higher pregnancy rate than morulae, similarly cryopreserved (47.1% vs. 24.3%, p < 0.05). In conclusion, MDV is an effective alternative methodology for cryopreservation of in vivo-derived embryos. This study gives also indication that, compared to vitrified blastocysts, MDV of morula stage embryos results in higher pregnancy rates following warming and transfer into synchronized recipients.

Construction of a cDNA library and preliminary analysis of expressed sequence tags in Piper hainanense.

Black pepper is a perennial climbing vine. It is widely cultivated because its berries can be utilized not only as a spice in food but also for medicinal use. This study aimed to construct a standardized, high-quality cDNA library to facilitated identification of new Piper hainanense transcripts. For this, 262 unigenes were used to generate raw reads. The average length of these 262 unigenes was 774.8 bp. Of these, 94 genes (35.9%) were newly identified, according to the NCBI protein database. Thus, identification of new genes may broaden the molecular knowledge of P. hainanense on the basis of Clusters of Orthologous Groups and Gene Ontology categories. In addition, certain basic genes linked to physiological processes, which can contribute to disease resistance and thereby to the breeding of black pepper. A total of 26 unigenes were found to be SSR markers. Dinucleotide SSR was the main repeat motif, accounting for 61.54%, followed by trinucleotide SSR (23.07%). Eight primer pairs successfully amplified DNA fragments and detected significant amounts of polymorphism among twenty-one piper germplasm. These results present a novel sequence information of P. hainanense, which can serve as the foundation for further genetic research on this species.

Viscosupplementation of synovial fluid with xanthan gum for treatment of osteoarthritis and its clearance kinetics in the rabbit knee joint.

BACKGROUND: Injection of xanthan gum (XG) has been demonstrated to reduce the symptoms and progression of osteoarthritis (OA) in experimental models. Due to its high viscosity and stability, it may restore the rheological homeostasis of osteoarthritic synovial fluid (SF), and avoid numerous intra-articular injections. OBJECTIVE: The present study investigated the effect of XG on the rheological properties of SF, and determined its residence time in the rabbit joint cavity. METHODS: Rabbit knees were subject to intra-articular injection with XG or XG labeled with green fluorescence, and the SF was collected at different time. Rheological properties of SF with XG injected were compared with those with sodium hyaluronate injected. Resistance to oxidant damage was tested by adding H2O2 to the viscosupplement. Fluorescence intensity was measured for the SF with XG labeled with green fluorescence. RESULTS: Results showed that XG could significantly improve the SF viscosity at 24, 96, 168 h, and increase the storage moduli (G') and loss moduli (G″) tested at frequency of 0.5 and 2.5 Hz. SF with XG injection exhibited a gel-like behavior at 24 h, in that G' exceed G″ over the entire oscillation frequency range. XG preparation had a high resistance to oxidant damage. Half-life of XG in the joint cavity was 35.9 h, with clearance obeying first-order kinetics. CONCLUSIONS: Intra-articular injection of XG could improve the rheological properties of SF, and this effect could last for several days.

Comparing the effects of meal replacements with an isocaloric reduced-fat diet on nutrient intake and lower urinary tract symptoms in obese men.

BACKGROUND: Lower urinary tract symptoms (LUTS) in men are associated with obesity, particularly central obesity as measured by waist circumference (WC), and may improve with weight loss. We aimed to compare effects of a meal-replacement based diet with isocaloric reduced-fat plan on LUTS and nutrient intake in obese Asian men. METHODS: Obese Asian [mean (range) body mass index of 32.9 (30.5-42.3) kg m(-2) ] men [mean (range) age 40.2 (30-61) years] were randomised to a reduced-fat (< 30% of energy) diet [conventional reduced-fat diet (CD) group; n = 23] or meal-replacement-based plan [meal replacement (MR) group; n = 23], to reduce daily intake by 2000 kJ for 12 weeks. RESULTS: CD and MR groups had statistically significant and similar reductions in weight (-2.6 ± 1.9 kg versus -4.2 ± 3.8 kg), overall LUTS severity measured with International Prostate Symptom Scale (IPSS) scores (-1.71 ± 1.93 points versus -2.42 ± 2.12 points) and insulin resistance [homeostasis model assessment (HOMA) calculated from plasma glucose and insulin]. The MR group had significantly greater decreases in WC (-4.8 ± 3.3 cm versus -2.5 ± 2.3 cm), fat mass (-2.47 ± 3.63 kg versus -1.59 ± 2.32 kg), fat intake, plasma C-reactive protein, and in storage LUTS score (-1.59 ± 1.33 points versus -1.00 ± 0.87 points), which was associated with a decreased fat intake (r = 0.48, P = 0.03). A decrease in overall IPSS score was associated with reductions in weight, WC and HOMA. CONCLUSIONS: Weight loss as a result of CD or MR had similar efficacy in relieving LUTS. MR produced greater reductions in fat intake, adiposity and storage LUTS.

Comparing the effects of meal replacements with reduced-fat diet on weight, sexual and endothelial function, testosterone and quality of life in obese Asian men.

Sexual dysfunction is more prevalent in obese than in normal-weight men. Meal replacements (MRs) are useful weight-loss strategies. We randomized obese (body mass index 27.5 kg m(-2), waist circumference (WC) 90 cm) Asian men (mean age 40.5 years, range 30-61) to a conventional reduced-fat diet (CD) (n=24) or MR-based plan (n=24) to reduce daily intake by 400 kcal for 12 weeks. There were significantly greater reductions in weight (4.2 ± 0.8 kg), WC (4.6 ± 0.7 cm), calorie and fat intake in the MR group, compared with the CD group (2.5 ± 0.4 kg, 2.6 ± 0.5 cm). Erectile function (International Index of Erectile Function 5-item score) improved comparably in the MR (3.4 ± 0.7 points) and CD (2.5 ± 0.5 points) groups, as did the Sexual Desire Inventory score (5.5 ± 2.3 vs 7.7 ± 2.1 points), quality of life (36-item Short Form survey score), plasma testosterone and endothelial function (Reactive Hyperemia Index). Subjects were switched to or continued CD for another 28 weeks. Weight, WC and erectile function were maintained at 40 weeks. MR induces greater reductions in weight and abdominal obesity than conventional diet, and comparable improvements in sexual and endothelial function, testosterone and quality of life.

Selenium increases chlorogenic acid, chlorophyll and carotenoids of Lycium chinense leaves.

BACKGROUND: Leaves of Lycium chinense L. are widely used in traditional Chinese medicine and as functional food in China and south-east Asia. Polyphenols are important active compounds in leaves of L. chinense L, but their compositions are still not very clear. Selenium has been reported to increase some components of plants. In this study, the composition of polyphenols of L. chinense leaves were analysed, and the effects of selenium on the polyphenols and other components were studied. RESULTS: The main polyphenols were identified as rutin, chlorogenic acid, quercetin, kaempferol and apigenin-7-O-(6'-O-acetyl) glucose-rhamnose. Chlorogenic acid showed the highest average content of 78.36 g kg⁻¹. Rutin, quercetin and kaempferol were determined at low contents from 3.85 g kg⁻¹ to 7.08 g kg⁻¹. Correlation coefficients between selenium and chlorogenic acid, chlorophyll a, chlorophyll b and carotenoids were: R² = 0.963 (P = 0.002), 0.943 (P = 0.005), 0.957 (P = 0.003) and 0.943 (P = 0.005), respectively. Selenium (0.01-0.05 g kg⁻¹) significantly increased chlorogenic acid, chlorophyll and carotenoids by 200-400% and reduced rutin by 400-900%. CONCLUSION: L. chinense can be an alternative source of chlorogenic acid. Selenium significantly increased chlorogenic acid, chlorophyll a, chlorophyll b and carotenoids, hence increasing the medicinal value of L. chinense leaves. Rutin, quercetin, kaempferol and apigenin-7-O-(6'-O-acetyl) glucose-rhamnose proved to be not significantly influenced by selenium.

Hyaluronic acid in combination with chondroitin sulfate and hyaluronic acid improved the degeneration of synovium and cartilage equally in rabbits with osteoarthritis.

The purpose of this study was to compare the chondroprotective effects of chondroitin sulfate (CS)-hyaluronic acid (HA) (CS-HA) injection and HA injection in an experimental model of osteoarthritis. After induction of osteoarthritis in rabbits, 28 rabbits were randomized into four groups: control group, 'HA' group, 'CS' group, and 'CS-HA' group. After 7 days, rabbits in the control group, 'HA' group, 'CS' group and 'CS-HA' group were respectively treated with normal saline, HA, CS, or CS-HA injection in the knees. All animals were treated once weekly. The animals were treated continuously for 5 weeks. Histological and biochemical evaluations were performed. As shown by histological observation, CS-HA injection treatment showed a chondroprotective effect on osteoarthritis. However, the histological scores of 'HA' group and 'CS-HA' group were not significantly different (p > 0.05). The results of biochemical evaluation showed that the expression levels of IL-1ß, TNF-α, TIMP-1 and NO in synovial fluid of treated groups were all different from the control group (p < 0.05). However, the expression levels of these biochemical molecules in three treated groups were not significantly different (p > 0.05). In conclusion, CS-HA injection showed no obvious advantage over HA injection in osteoarthritis treatment.

Pulmonary artery aneurysm associated with severe degenerative aortic stenosis.

We report a pulmonary artery (PA) aneurysm associated with severe aortic stenosis and an aortic root dilatation occurring in a 59-year-old woman who presented with dyspnoea and chest pain. PA aneurysms are rare, and there are no definitive guidelines on its management. There are contentious opinions on whether such aneurysms should be managed conservatively or surgically. Our patient had associated aortic stenosis and underwent a successful aortic valve replacement and PA aneurysm repair. This case illustrates that concomitant PA repair with other cardiothoracic surgery can be performed safely, even in patients with moderate surgical risks. We also discuss the natural history, prognosis and management of PA aneurysms.

Use of induction promoters to regulate hyaluronan synthase and UDP-glucose-6-dehydrogenase of Streptococcus zooepidemicus expression in Lactococcus lactis: a case study of the regulation mechanism of hyaluronic acid polymer.

AIMS: To determine the effects of the ratios of hyaluronan synthase expression level to precursor sugar UDP-GlcA biosynthesis ability on the molecular weight (MW) of hyaluronic acid (HA) in recombinant Lactococcus lactis. METHODS AND RESULTS: The genes szHasA (hyaluronan synthase gene) and szHasB (UDP-glucose-6-dehydrogenase gene) of Streptococcus zooepidemicus were introduced into L. lactis under the control of nisA promoter and lacA promoter respectively, resulting in a dual-plasmid controlled expression system. The effects of the ratios of hyaluronan synthase expression level to the precursor sugar UDP-GlcA biosynthesis ability under different induction concentration collocations with nisin and lactose on the MW of HA in recombinant L. lactis were determined. The results showed that the final weight-average molecular weight () of HA correlated with the relative ratios of HasA (hyaluronan synthase) expression level to the concentration of UDP-GlcA. CONCLUSIONS: Regulating the relative ratios of HasA expression level to the precursor sugar biosynthesis ability was an efficient method to control the size of HA. SIGNIFICANCE AND IMPACT OF THE STUDY: This study put forward a guide to establish an efficacious way to control the size of HA in fermentation.

Effects of a hyaluronic acid and low molecular weight heparin injection on osteoarthritis in rabbits.

An osteoarthritis (OA) model was created in the knees of rabbits by injecting them with 0.3 mL of sterile papain solution in order to evaluate the effects of a hyaluronic acid (HA) and low molecular weight heparin (LMWH) injection on osteoarthritis. HA-LMWH, LMWH, and HA were injected into animals once weekly. After 5 weeks of treatment, the animals were sacrificed and the effects of the injections on osteoarthritis were evaluated by histological assessment. HA levels in cartilage and the levels of IL-1ß and TNF-α expression in synovial fluids were determined. As shown by histological observation, recovery of the synovium and cartilage of animals injected with HA-LMWH was better than that in animals injected with HA or LMWH. HA levels in cartilage of animals injected with HA-LMWH were much higher than those of the control group. The levels of IL-1ß expression in synovial fluids of animals injected with HA-LMWH were lower than those in other animals. The levels of TNF-α expression in synovial fluids of animals injected with HA-LMWH were much lower than those in the controls. In conclusion, HALMWH injection had a favorable anti-inflammatory and therapeutic effect on experimental OA.

How tobacco protects you against the flu.

Under the heading "How tobacco protects you against the flu", the German chemical industry portrays a tobacco grower in an idyllic tobacco plantation. Despite the recent ban of transnational tobacco advertising within the European Union, using tobacco to promote another industry and potential societal health benefits might indirectly promote the social acceptability of tobacco to social leaders. The tobacco control community should thus monitor the use of other industries as a new method to circumvent the tobacco advertising ban and to support the social acceptability of tobacco by associating it with potential health benefits.