A tribo-mechanical analysis of PVA-based building-blocks for implementation in a 2-layered skin model

Poly(vinyl) alcohol hydrogel (PVA) is a well-known polymer widely used in the medical field due to its biocompatibility properties and easy manufacturing. In this work, the tribo-mechanical properties of PVA-based blocks are studied to evaluate their suitability as a part of a structure simulating the length scale dependence of human skin. Thus, blocks of pure PVA and PVA mixed with Cellulose (PVA-Cel) were synthesised via freezing/thawing cycles and their mechanical properties were determined by Dynamic Mechanical Analysis (DMA) and creep tests. The dynamic tests addressed to elastic moduli between 38 and 50kPa for the PVA and PVA-Cel, respectively. The fitting of the creep compliance tests in the SLS model confirmed the viscoelastic behaviour of the samples with retardation times of 23 and 16 seconds for the PVA and PVA-Cel, respectively. Micro indentation tests were also achieved and the results indicated elastic moduli in the same range of the dynamic tests. Specifically, values between 45-55 and 56-81kPa were obtained for the PVA and PVA-Cel samples, respectively. The tribological results indicated values of 0.55 at low forces for the PVA decreasing to 0.13 at higher forces. The PVA-Cel blocks showed lower friction even at low forces with values between 0.2 and 0.07. The implementation of these building blocks in the design of a 2-layered skin model (2LSM) is also presented in this work. The 2LSM was stamped with four different textures and their surface properties were evaluated. The hydration of the 2LSM was also evaluated with a corneometer and the results indicated a gradient of hydration comparable to the human skin.

Prurigo pigmentosa: a clinical and histopathological study of nine Chinese cases

BACKGROUND

Prurigo pigmentosa (PP) is a chronic and recurrent inflammatory skin disease with the distinctive and prominent feature of reticulate hyperpigmentation. Most known cases have been reported in Japan; here we report nine Chinese cases.

OBJECTIVE

To determine the clinical manifestation of PP and its effects in Chinese individuals compared with patients of other ethnicities.

METHODS

We retrospectively analysed nine cases of PP. For all cases, clinical information was collected and reviewed, and skin biopsies were performed. Furthermore, we followed all nine patients to determine the recurrence rate.

RESULTS

All nine patients fulfilled the diagnostic criteria of PP. The mean age of the patients at diagnosis was 27.4 years, and the patients were predominantly female. Skin lesions at different stages commonly co-occurred in the same patient. The most commonly affected part of the body was the back, but the armpit was also often involved. Patients responded well to minocycline treatment for the short duration of 8.62 days, and a lower recurrence rate (28.3%) was recorded after treatment. Biopsy revealed classic neutrophil and (or) lymphocyte infiltration, spongiosis, and necrotic keratocytes. Abscesses occasionally occurred in the follicular orifice. The abnormal presentation of hair follicles was also discovered. All characteristics were found to coexist in different stages.

CONCLUSION

We conclude that PP is easy to misdiagnose. Histopathological characteristics can coexist at different stages, consistent with the clinical finding that different stages of skin lesions presented concurrently, contributing to misdiagnosis. Oral administration of minocycline not only yields an excellent response but also effectively reduces the recurrence rate.

Chinese SLE Treatment and Research group (CSTAR) registry VII: prevalence and clinical significance of serositis in Chinese patients with systemic lupus erythematosus

Objectives

To investigate both the prevalence and clinical characteristics of serositis in Chinese patients with systemic lupus erythematosus (SLE) in a large cohort in the Chinese SLE Treatment and Research group (CSTAR) database.

Methods

A prospective cross-sectional study of patients with SLE was conducted based on the data from the CSTAR registry. Serositis was defined according to the 1999 revised American College of Rheumatology (ACR) criteria for SLE – that is, pleuritis/pleural effusion and/or pericarditis/pericardial effusion detected by echocardiography, chest X-ray or chest computerized tomography (CT) scan. Peritonitis/peritoneal effusion were confirmed by abdominal ultrasonography. We analysed the prevalence and clinical associations of serositis with demographic data, organ involvements, laboratory findings and SLE disease activity.

Results

Of 2104 patients with SLE, 345 were diagnosed with serositis. The prevalence of lupus nephritis (LN), interstitial lung disease and pulmonary arterial hypertension, as well as the presence of leukocytopenia, thrombocytopenia, hypocomplementemia and anti-dsDNA antibodies was significantly higher in patients with serositis ( P < 0.05). Significantly higher SLE disease activity scores were found in patients with serositis compared to those patients without serositis ( P < 0.05). Lupus-related peritonitis had similar clinical manifestations and laboratory profiles as serositis caused by SLE.

Conclusions

There is a significant association of nephropathy, interstitial lung disease, pulmonary arterial hypertension, hypocomplementemia, leukocytopenia, thrombocytopenia and elevated anti-dsDNA antibodies with serositis. The results suggest that higher SLE disease activity contributes to serositis development, and should be treated aggressively.

Temporal Progression of Lesions in Guinea Pigs Infected With Lassa Virus

Lassa virus (LASV) infection causes an acute, multisystemic viral hemorrhagic fever that annually infects an estimated 100 000 to 300 000 persons in West Africa. This pathogenesis study evaluated the temporal progression of disease in guinea pigs following aerosol and subcutaneous inoculation of the Josiah strain of LASV as well as the usefulness of Strain 13 guinea pigs as an animal model for Lassa fever. After experimental infection, guinea pigs ( Cavia porcellus; n = 67) were serially sampled to evaluate the temporal progression of infection, gross and histologic lesions, and serum chemistry and hematologic changes. Guinea pigs developed viremia on day 5 to 6 postexposure (PE), with clinical signs appearing by day 7 to 8 PE. Complete blood counts revealed lymphopenia and thrombocytopenia. Gross pathologic findings included skin lesions and congested lungs. Histologic lesions consisted of cortical lymphoid depletion by day 6 to 7 PE with lymphohistiocytic interstitial pneumonia at 7 to 8 days PE. Scattered hepatocellular degeneration and cell death were also noted in the liver and, to a lesser extent, in other tissues including the haired skin, lung, heart, adrenal gland, lymph nodes, thymus, and spleen. The first cell types to demonstrate staining for viral antigen were fibroblastic reticular cells and macrophages/dendritic cells in the lymph nodes on day 5 to 6 PE. This study demonstrates similarities between Lassa viral disease in human infections and experimental guinea pig infection. These shared pathologic characteristics support the utility of guinea pigs as an additional animal model for vaccine and therapeutic development under the Food and Drug Administration's Animal Rule.

Label-free aptasensor for adenosine deaminase sensing based on fluorescence turn-on

A label-free and fluorescence turn-on aptamer biosensor has been developed for the detection of adenosine deaminase (ADA) activity with simplicity and selectivity. Adenosine aptamer will form a tight stem-loop structure upon binding with adenosine. In the absence of ADA, only a small quantity of picagreen intercalates into the stem section of aptamer, resulting in a low fluorescence of picagreen when excited at 490 nm. Interestingly, after the addition of ADA, adenosine is hydrolyzed to inosine, and the released aptamer forms double-stranded DNA (dsDNA) with its complementary single-stranded DNAc, followed by the intercalation of picagreen to dsDNA. When the solution is excited, picagreen emits strong green fluorescence. The increased fluorescence intensity of picagreen is dependent on the concentration of ADA. The detection limit of the ADA is determined to be 2 U L(-1), which is lower than ADA cutoff value (4 U L(-1)) in the clinical requirement and more sensitive than most of the reported methods. Compared to other previous ADA sensors, the assay is not only label-free but also a turn-on signal, and possesses properties of lower cost and simpler detection system. Furthermore, this label-free strategy is also applicable to the assay of other enzymes and screening of corresponding inhibitors.

Socioeconomic inequalities in dental caries among 5-year-olds in four Chinese provinces

OBJECTIVE

To explore socioeconomic inequalities in dental caries among 5-year-olds in four Chinese provinces.

METHODS

This study used data from 1,732 children living in Guangxi, Hubei, Jilin and Shanxi who participated in the Third National Oral Health Survey in 2005. Questionnaires were completed by parents to collect information on family socioeconomic position (parental education and household income) and children's dental behaviours (toothbrushing frequency, sugar intake frequency and last dental visit). Children were clinically examined for dental caries, which was reported using the dmft index. Socioeconomic inequalities in children's caries experience were assessed in negative binomial regression models.

RESULTS

There were significant gradients in children's dmft by household income. Children's dmft increased from 2.63 in the highest income group to 4.70 in the lowest income group. However, parental education was not significantly related to childhood dental caries.

CONCLUSION

Clear social gradients in caries experience of deciduous teeth were found by household income but not parental education.

Chinese SLE Treatment and Research group (CSTAR) registry: V. gender impact on Chinese patients with systemic lupus erythematosus

Introduction

Many studies have shown that differences were observed between male and female lupus patients. Although systemic lupus erythematosus (SLE) affects mostly females (female:male ratio 9:1), male SLE patients show higher mortality due to kidney and neurological disease. Currently there are limited epidemiological data concerning lupus in the Chinese population. As such, the Chinese SLE Treatment and Research group (CSTAR) developed the first online registry of Chinese lupus patients in 2009, and represents a multicenter observational study that attempts to describe and compile the major clinical characteristics of lupus in Chinese patients.

Objective

To investigate the effect of gender on the phenotypes of Chinese SLE patients.

Patients and methods

Data for 2104 SLE patients were prospectively collected and included in the CSTAR registry. Patients fulfilled the 1997 American College of Rheumatology (ACR) SLE classification criteria. We conducted a cross-sectional case-control study to analyze patient clinical and laboratory data at onset and at enrollment. SLE disease activity scores (SLEDAI) were also measured at enrollment.

Results

This study included 1914 women and 190 men. Males and females showed no differences in mean ages at onset, delay of diagnosis and disease duration. Males presented more frequently with fever ( p = 0.003), while musculoskeletal involvement ( p = 0.001) and cytopenia ( p = 0.017) was more common in females as the initial manifestation at onset of SLE. For manifestations at enrollment, males presented more frequently with fever ( p = 0.005), renal disease ( p = 0.019), vasculitis ( p = 0.032) and neuropsychiatric lupus ( p = 0.007). For cumulative manifestations at enrollment, males presented more frequently with discoid rash ( p < 0.001) and neuropsychiatric lupus ( p = 0.036), while less frequently with arthritis ( p = 0.011). However, the laboratory data showed no significant differences between the two groups at enrollment. Males also had higher SLEDAI scores at enrollment ( p = 0.002).

Conclusions

Renal disease, vasculitis and neuropsychiatric lupus are more common in male SLE patients with higher SLEDAI scores compared to female SLE patients in China.

Resveratrol regulates mitochondrial reactive oxygen species homeostasis through Sirt3 signaling pathway in human vascular endothelial cells

Mitochondrial reactive oxygen species (mtROS) homeostasis plays an essential role in preventing oxidative injury in endothelial cells, an initial step in atherogenesis. Resveratrol (RSV) possesses a variety of cardioprotective activities, however, little is known regarding the effects of RSV on mtROS homeostasis in endothelial cells. Sirt3 is a mitochondrial deacetylase, which plays a key role in mitochondrial bioenergetics and is closely associated with oxidative stress. The goal of the study is to investigate whether RSV could attenuate oxidative injury in endothelial cells via mtROS homeostasis regulation through Sirt3 signaling pathway. We found that pretreatment with RSV suppressed tert-butyl hydroperoxide (t-BHP)-induced oxidative damage in human umbilical vein endothelial cells (HUVECs) by increasing cell viability, inhibiting cell apoptosis, repressing collapse of mitochondrial membrane potential and decreasing mtROS generation. Moreover, the enzymatic activities of isocitrate dehydrogenase 2 (IDH2), glutathione peroxidase (GSH-Px) and manganese superoxide dismutase (SOD2) as well as deacetylation of SOD2 were increased by RSV pretreatment, suggesting RSV notably enhanced mtROS scavenging in t-BHP-induced endothelial cells. Meanwhile, RSV remarkably reduced mtROS generation by promoting Sirt3 enrichment within the mitochondria and subsequent upregulation of forkhead box O3A (FoxO3A)-mediated mitochondria-encoded gene expression of ATP6, CO1, Cytb, ND2 and ND5, thereby leading to increased complex I activity and ATP synthesis. Furthermore, RSV activated the expressions of phosphorylated adenosine monophosphate-activated protein kinase (p-AMPK), peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) and Sirt3, as well as estrogen-related receptor-α (ERRα)-dependent Sirt3 mRNA transcription, which were abolished in the presence of AMPK inhibitor and AMPK, PGC-1α or Sirt3 siRNA transfection, indicating the effects of RSV on mtROS homeostasis regulation were dependent on AMPK-PGC-1α-ERRα-Sirt3 signaling pathway. Our findings indicated a novel mechanism that RSV-attenuated oxidative injury in endothelial cells through the regulation of mtROS homeostasis, which, in part, was mediated through the activation of the Sirt3 signaling pathway.

Blocking autophagy enhanced cytotoxicity induced by recombinant human arginase in triple-negative breast cancer cells

Depletion of arginine by recombinant human arginase (rhArg) has proven to be an effective cancer therapeutic approach for a variety of malignant tumors. Triple-negative breast cancers (TNBCs) lack of specific therapeutic targets, resulting in poor prognosis and limited therapeutic efficacy. To explore new therapeutic approaches for TNBC we studied the cytotoxicity of rhArg in five TNBC cells. We found that rhArg could inhibit cell growth in these five TNBC cells. Intriguingly, accumulation of autophagosomes and autophagic flux was observed in rhArg-treated MDA-MB-231 cells. Inhibition of autophagy by chloroquine (CQ), 3-methyladenine (3-MA) and siRNA targeting Beclin1 significantly enhanced rhArg-induced cytotoxic effect, indicating the cytoprotective role of autophagy in rhArg-induced cell death. In addition, N-acetyl-l-cysteine (NAC), a common antioxidant, blocked autophagy induced by rhArg, suggesting that reactive oxygen species (ROS) had an essential role in the cytotoxicity of rhArg. This study provides new insights into the molecular mechanism of autophagy involved in rhArg-induced cytotoxicity in TNBC cells. Meanwhile, our results revealed that rhArg, either alone or in combination with autophagic inhibitors, might be a potential novel therapy for the treatment of TNBC.

TRAIL-expressing gingival-derived mesenchymal stem cells inhibit tumorigenesis of tongue squamous cell carcinoma

Recent research has verified that mesenchymal stromal/stem cells (MSCs) derived from bone marrow or adipose tissues can migrate toward a variety of tumors. In this study, we explored whether human gingival-derived MSCs (G-MSCs) can migrate toward tongue squamous cell carcinoma (TSCC) and evaluated the antitumor effect of engineered G-MSCs in expressing and delivering the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). An in vitro cell migration assay with Transwell plates showed that human G-MSCs can migrate toward TSCC cell lines (Tca8113 and Cal27). Then, human G-MSCs, as a type of cell-based vehicle, were transduced with full-length TRAIL and enhanced green fluorescent protein reporter genes by the lentivirus (LV) system (G-MSCs with full-length TRAIL; G-MSCFLT). Tca8113 and Cal27 were co-cultured with G-MSCFLT, respectively, to evaluate the function of G-MSCFLT on tumor cells in vitro. This resulted in G-MSCFLT's inducing a great number of tumor cell necrosis and apoptosis. Meanwhile, in vivo antitumor assays were performed by administering G-MSCFLT to nude mice locally and systematically (mixed injection with tumor cells and tail vein injection). This showed that G-MSCFLT can reduce or even inhibit TSCC growth regardless of the method of administration, especially when the mixed injection of tumor cells and G-MSCFLT was at a ratio of 1:1, which showed no tumor formation. Furthermore, this verified that G-MSCFLT migrated toward TSCC in quantity. These data emphasize the effectiveness of G-MSCs as a vehicle for cell-based gene therapy and the antitumor activity of TRAIL-expressing G-MSCs.

Clinical and laboratory characteristics of systemic sclerosis patients with pulmonary arterial hypertension in China

OBJECTIVES

Pulmonary arterial hypertension (PAH) is associated with significant morbidity and mortality, especially in systemic sclerosis (SSc). Since there was no published study regarding PAH in the Chinese SSc population, we aimed to describe a cohort to provide some data for early diagnosis.

METHODS

We evaluated 236 systemic sclerosis patients prospectively registered in the EUSTAR (European League Against Rheumatism Scleroderma Trial and Research Group) database from the Peking Union Medical College Hospital from 2009 to 2012. Among them, 33 individuals received right heart catheterisations (RHC) while the remaining patients were grouped by echocardiographic data. These patients were classified into two groups, PAH and non-PAH group. Their clinical and laboratory features were statistically analysed to identify possible risk factors for PAH in Chinese SSc population.

RESULTS

The possible prevalence of PAH in SSc patients was approximately 11% in our study. Digital ulcers (52.0% vs. 31.2%), telangiectasias (64.0% vs. 37.6%) and gastroesophageal reflux disease (GERD) (60.0% vs. 36.2%) were more common in SSc patients with PAH. Some laboratory results were also proved to be significantly correlated with it. Logistic regression analysis showed that telangiectasias (OR=2.888, 95% CI=1.176-7.093), presence of GERD (OR=2.592, 95% CI=1.067-6.296), anti-RNP positivity (OR=24.384, 95% CI=1.978-36.651), IgA level elevation (OR=8.745, 95% CI 4.838-122.896) and FVC/TLCO ratio (OR=97.067, 95% CI 12.475-755.271) were associated with an increased odds for PAH in SSc patients.

CONCLUSIONS

This study described possible predictors of PAH in Chinese SSc population, which have been supported by similar studies in other ethnic groups.