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Introduction: Increased alcohol and cannabis consumption and related harms have been reported since the beginning of the COVID-19 pandemic. Existing evidence shows that substance use and related harms differ by gender. Yet, no Canadian study has applied a gendered lens to alcohol and cannabis consumption use during this time. Our objectives were to (1) provide gender-specific prevalence estimates of self-reported increased alcohol and cannabis use; and (2) examine gender-specific associations between sociodemographic and mental health variables and alcohol and cannabis use., Methods: Using data from the Survey on COVID-19 and Mental Health, we calculated nationally representative, gender-specific prevalence estimates and disaggregated them by sociodemographic and mental health variables. Four logistic regression models were used to assess the likelihood of self-reported increased alcohol and cannabis use., Results: The prevalence of self-reported increase in alcohol use (16.2% women; 15.2% men) and cannabis use (4.9% women; 5.8% men) did not differ by gender. For both genders, income, racialized group membership, working in the past week, being a parent/legal guardian of a child aged under 18 and screening positive for depression and anxiety were associated with increased alcohol use. Men and women who were between the ages of 18 to 44, screened positive for depression, or both, were more likely to report increased cannabis use. For women, education was significantly associated with increased alcohol use. For men, being a parent/legal guardian was significantly associated with lower odds of increased cannabis use., Conclusion: Sociodemographic factors, as well as depression and anxiety, were similarly associated with increased alcohol and cannabis use for both men and women in the second wave of the pandemic., Competing Interests: The authors have no conflicts of interest to disclose.

Sickle cell disease (SCD) is associated with chronic hemolytic anemia and a heightened inflammatory state. The causal role of inflammatory pathways in stroke associated with SCD is unclear. Therefore, the hypothesis that deletion of the non-hematopoietic interleukin-1 receptor (IL-1R) pool may be beneficial in SCD was pursued. Since potential deleterious effects of IL-1R signaling in SCD could be mediated via downstream production of interleukin-6 (IL-6), the role of the non-hematopoietic IL-6 pool was also addressed. Bone marrow transplantation (BMT) from SCD to wild-type (WT) recipient mice was used to generate SCD mice (Wt,SCDbmt). To generate mice with non-hematopoietic deficiency of IL-1R or IL-6, SCD marrow was transplanted into IL-1R deficient (IL1R-/-,SCDbmt) or IL-6 deficient recipients (IL6-/-,SCDbmt). Blood counts, reticulocytes, soluble E-selectin (Esel), and IL-6 levels were analyzed 14-15 weeks post-BMT. Ischemic stroke was induced by middle cerebral artery (MCA) photothrombosis at 16 weeks post-BMT. A separate group of Wt,SCDbmt mice was given the IL-1R inhibitor, anakinra, following stroke induction. Seventy-two hours after MCA occlusion, stroke volume was assessed by staining brain sections with 2,3,5-triphenyltetrazolium chloride. Formalin-fixed brain sections were also stained for macrophages with MAC3, for endothelial activation with ICAM-1, and for loss of blood brain barrier (BBB) integrity with fibrin(ogen) staining. All SCD mice generated by BMT were anemic and the severity of anemia was not different between Wt,SCDbmt, IL1R-/-,SCDbmt, and IL6-/-,SCDbmt mice. Three days following MCA occlusion, stroke volume was significantly reduced in IL1R-/-,SCDbmt mice compared to Wt,SCDbmt mice and IL6-/-,SCDbmt mice. Plasma levels of sE-sel were lower in IL1R-/-,SCDbmt compared to Wt,SCDbmt and IL-6-/-,SCDbmt mice. Post-stroke treatment of Wt,SCDbmt mice with anakinra decreased stroke size, leukocyte infiltration, ICAM-1 expression, and fibrin(ogen) accumulation compared to vehicle-treated mice. Deficiency of non-hematopoietic IL-1R or treatment with an IL-1R antagonist is sufficient to confer protection against the increased stroke size associated with SCD. These effects of IL1R deficiency are associated with reduced endothelial activation, leukocyte infiltration, and blood brain barrier disruption, and are independent of non-hematopoietic IL-6 signaling.

Objective: To assess the individual and community health effects of task shifting for emergency care in low-resource settings and underserved populations worldwide., Methods: We systematically searched 13 databases and additional grey literature for studies published between 1984 and 2019. Eligible studies involved emergency care training for laypeople in underserved or low-resource populations, and any quantitative assessment of effects on the health of individuals or communities. We conducted duplicate assessments of study eligibility, data abstraction and quality. We synthesized findings in narrative and tabular format., Findings: Of 19 308 papers retrieved, 34 studies met the inclusion criteria from low- and middle-income countries (21 studies) and underserved populations in high-income countries (13 studies). Targeted emergency conditions included trauma, burns, cardiac arrest, opioid poisoning, malaria, paediatric communicable diseases and malnutrition. Trainees included the general public, non-health-care professionals, volunteers and close contacts of at-risk populations, all trained through in-class, peer and multimodal education and public awareness campaigns. Important clinical and policy outcomes included improvements in community capacity to manage emergencies (14 studies), patient outcomes (13 studies) and community health (seven studies). While substantial effects were observed for programmes to address paediatric malaria, trauma and opioid poisoning, most studies reported modest effect sizes and two reported null results. Most studies were of weak (24 studies) or moderate quality (nine studies)., Conclusion: First aid education and task shifting to laypeople for emergency care may reduce patient morbidity and mortality and build community capacity to manage health emergencies for a variety of emergency conditions in underserved and low-resource settings., ((c) 2021 The authors; licensee World Health Organization.)

Background: Task shifting and sharing (TS/S) involves the redistribution of health tasks within workforces and communities. Conceptual frameworks lay out the key factors, constructs, and variables involved in a given phenomenon, as well as the relationships between those factors. Though TS/S is a leading strategy to address health worker shortages and improve access to services worldwide, a conceptual framework for this approach is lacking., Methods: We used an online Delphi process to engage an international panel of scholars with experience in knowledge synthesis concerning TS/S and develop a conceptual framework for TS/S. We invited 55 prospective panelists to participate in a series of questionnaires exploring the purpose of TS/S and the characteristics of contexts amenable to TS/S programmes. Panelist responses were analysed and integrated through an iterative process to achieve consensus on the elements included in the conceptual framework., Results: The panel achieved consensus concerning the included concepts after three Delphi rounds among 15 panelists. The COATS Framework (Concepts and Opportunities to Advance Task Shifting and Task Sharing) offers a refined definition of TS/S and a general purpose statement to guide TS/S programmes. COATS describes that opportunities for health system improvement arising from TS/S programmes depending on the implementation context, and enumerates eight necessary conditions and important considerations for implementing TS/S programmes., Conclusion: The COATS Framework offers a conceptual model for TS/S programmes. The COATS Framework is comprehensive and adaptable, and can guide refinements in policy, programme development, evaluation, and research to improve TS/S globally.

Introduction: Many Indigenous peoples around the world are disproportionately affected by mental health challenges, due to intergenerational and collective trauma stemming from historical losses and ongoing colonialism. A growing body of literature suggests that mental wellness initiatives are more culturally safe and result in more successful and sustainable outcomes when they are developed by, for and with Indigenous communities using community-driven approaches that prioritize and privilege Indigenous leadership, knowledge systems, beliefs and practices. However, knowledge has not been synthesized on mental wellness initiatives and the extent of community engagement during the development, implementation, and evaluation stages of these initiatives., Methods: The authors conducted a scoping review of studies on Indigenous community-based mental wellness initiatives to identify the (1) characteristics of these initiatives, (2) types of evaluation approaches (specific measures and assessment tools), (3) level of community engagement from inception to the evaluation stage of the initiative, and (4) lessons learned as identified by the authors. Published and grey literature were searched across several electronic databases. Inclusion criteria required that each study was published between January 2008 and June 2018, focused on Indigenous peoples and their communities in Canada, USA, Australia, and/or New Zealand, focused on a community-based mental wellness initiative, was meaningfully co-led or co-designed by the community, described the initiative and how it was evaluated, and was printed in English., Results: The search yielded 1491 unique articles, and 22 of these articles met all of the inclusion criteria. All included studies took place in Canada, the USA, or Australia. Most mental wellness initiatives addressed general mental wellness, substance use, suicide prevention, and/or co-occurring conditions, and many were tailored for Indigenous youth. Culture-based initiatives were emphasized in most studies, with cultural adaptation and relevance prioritized in all initiatives. Approaches to evaluation ranged from process evaluations to outcome evaluations. Most studies used a mixed methods approach and a wide range of assessment tools, including questionnaires and indicators of community capacity building. Many evaluations used a shared leadership model between community leaders and researchers and had combinations of community members, families, Elders, Knowledge Keepers, and leaders involved in the development, implementation, and evaluation of the mental wellness initiative. Common challenges in conducting evaluation research included limitations of funding structures and the burden on community staff and leaders during the project., Conclusion: Overall, across all studies, culture stood out as a major theme for community-based mental wellness initiatives among rural and remote Indigenous communities, with cultural teachings, cultural activities, appropriate use of culture, land-based programming and knowledge sharing integrated into community programming. However, culture and Indigenous leadership throughout were lacking in many of the research studies. Thus, as more Indigenous communities and leaders govern and guide the development of evidence-based mental wellness programming, culture as a form of healing needs to be incorporated into the development of the program, and culture should be a core competency in any evaluation research.

As the effects of COVID-19 have been unfolding, growing attention has been paid to the intersection of COVID-19 and substance use and the related harms. However, there are few theories and little empirical evidence to guide investigations in this area. To advance this emerging area of inquiry, we present a conceptual model that synthesizes evidence, information and knowledge on substance use and related harms in the context of the pandemic. The conceptual model offers a visual representation of the connections between the pandemic and substance use and related harms, and can be used to identify areas for future research., Competing Interests: The authors have no conflicts of interest to disclose.

Transdermal drug delivery using microneedles is increasingly gaining interest due to the issues associated with oral drug delivery routes. Gastrointestinal route exposes the drug to acid and enzymes present in the stomach, leading to denaturation of the compound and resulting in poor bioavailability. Microneedle transdermal drug delivery addresses the problems linked to oral delivery and to relieves the discomfort of patients associated with injections to increase patient compliance. Microneedles can be broadly classified into five types: solid microneedles, coated microneedles, dissolving microneedles, hollow microneedles, and hydrogel-forming microneedles. The materials used for the preparation of microneedles dictate the different applications and features present in the microneedle. Polymeric microneedle arrays present an improved method for transdermal administration of drugs as they penetrate the skin stratum corneum barrier with minimal invasiveness. The review summarizes the importance of polymeric microneedle and discussed some of the most important therapeutic drugs in research, mainly protein drugs, vaccines and small molecule drugs in regenerative medicine., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objective: Clopidogrel is a commonly used P2Y 12 inhibitor to treat and prevent arterial thrombotic events. Clopidogrel is a prodrug that requires bioactivation by CYP (cytochrome P450) enzymes to exert antiplatelet activity. Diabetes mellitus is associated with an increased risk of ischemic events, and impaired ability to generate the active metabolite (AM) from clopidogrel. The objective of this study is to identify the mechanism of clopidogrel resistance in a murine model of diet-induced obesity (DIO). Approach and Results: C57BL/6J mice and IL-1R -/- mice were given high-fat diet for 10 weeks to generate a murine model of diet-induced obesity. Platelet aggregation and carotid arterial thrombosis were assessed in response to clopidogrel treatment. Wild-type DIO mice exhibited resistance to antiplatelet and antithrombotic effects of clopidogrel that was associated with reduced hepatic expression of CYP genes and reduced generation of the AM. IL (Interleukin)-1 receptor-deficient DIO (IL1R -/- DIO) mice showed no resistance to clopidogrel. Lack of resistance was accompanied by increased exposure of the clopidogrel AM. This resistance was also absent when wild-type DIO mice were treated with the conjugate of the clopidogrel AM, DT-678., Conclusions: These findings indicate that antiplatelet effects of clopidogrel may be impaired in the setting of diabetes mellitus due to reduced prodrug bioactivation related to IL-1 receptor signaling. Therapeutic targeting of P2Y 12 in patients with diabetes mellitus using the conjugate of clopidogrel AM may lead to improved outcomes.

Introduction: Task shifting interventions have been implemented to improve health and address health inequities. Little is known about how inequity and vulnerability are defined and measured in research on task shifting. We conducted a systematic review to identify how inequity and vulnerability are identified, defined and measured in task shifting research from high-income countries., Methods and Analysis: We implemented a novel search process to identify programs of research concerning task shifting interventions in high-income countries. We searched MEDLINE, Embase, CINAHL, PsycINFO, Web of Science, and CENTRAL to identify articles published from 2004 to 2016. Each program of research incorporated a "parent" randomized trial and "child" publications or sub-studies arising from the same research group. Two investigators extracted (1) study details, (2) definitions and measures of health equity or population vulnerability, and (3) assessed the quality of the reporting and measurement of health equity and vulnerability using a five-point scale developed for this study. We summarized the findings using a narrative approach., Results: Fifteen programs of research met inclusion criteria, involving 15 parent randomized trials and 62 child publications. Included programs of research were all undertaken in the United States, among Hispanic- (5/15), African- (2/15), and Korean-Americans (1/15), and low socioeconomic status (2/15), rural (2/15) and older adult populations (2/15). Task shifting interventions included community health workers, peers, and a variety of other non-professional and lay workers to address a range of non-communicable diseases. Some research provided robust analyses of the affected populations' health inequities and demonstrated how a task shifting intervention redressed those concerns. Other studies provided no such definitions and measured only biomedical endpoints., Conclusion: Included studies vary substantially in the definition and measurement of health inequity and vulnerability. A more precise theoretical and evaluative framework for task shifting is recommended to effectively achieve the goal of equitable health.

Endothelial dysfunction precedes atherosclerosis and may constitute a critical link between obesity-related inflammation and cardiovascular disease. Neutrophil extracellular traps (NETs) have been shown to promote vascular damage in murine models of autoimmune disease and atherosclerosis. The impact of NETs towards endothelial dysfunction associated with obesity is unknown. Using a diet-induced obesity (DIO) mouse model, this study investigated whether the inhibition or degradation of NETs could reduce the endothelial dysfunction observed in DIO mice. Following induction of DIO, there were elevated plasma concentrations of monocyte chemoattractant protein-1 (MCP-1) and impairment of mesenteric arteriolar vasorelaxation in response to acetylcholine as measured by pressure myography. A marker of NET formation, cathelicidin-related antimicrobial peptide (CRAMP), was markedly increased in mesenteric arterial walls of DIO mice compared to mice on standard chow. Prevention of NET formation with Cl-amidine or dissolution of NETs with DNase restored endothelium-dependent vasodilation to the mesenteric arteries of DIO mice. These findings suggest an instrumental role for NETs in obesity-induced endothelial dysfunction.

Identification of inflammatory mediators that regulate the vascular response to vasopressor molecules may aid in the development of novel therapeutic agents to treat or prevent hypertensive vascular diseases. Leukocytes have recently been shown to be capable of modifying blood pressure responses to vasopressor molecules. The purpose of this study was to test the hypothesis that deficiency of the leukocyte ligand, Psgl-1, would reduce the pressor response to angiotensin II (Ang II). Mice deficient in Psgl-1 (Psgl-1 -/- ) along with wild-type (WT) controls were treated for 2 weeks with a continuous infusion of Ang II. No differences in blood pressure between the groups were noted at baseline, however after 5 days of Ang II infusion, systolic blood pressures were higher in WT compared to Psgl-1 -/- mice. The pressor response to acute administration of high dose Ang II was also attenuated in Psgl-1 -/- compared to WT mice. Chimeric mice with hematopoietic deficiency of Psgl-1 similarly showed a reduced pressor response to Ang II. This effect was associated with reduced plasma interleukin-17 (IL-17) levels in Psgl-1 -/- mice and the reduced pressor response was restored by administration of recombinant IL-17. In conclusion, hematopoietic deficiency of Psgl-1 attenuates Ang II-induced hypertension, an effect that may be mediated by reduced IL-17.

Cardiotonic steroids (CTS) are compounds which bind to the Na,K-ATPase, leading to its inhibition and in some cases initiating signaling cascades. Long utilized as a treatment for congestive heart disease, CTS have more recently been observed to inhibit proliferation and cause apoptosis in several cancer cell lines. A synthetic derivative of the CTS digoxin, called 21-benzylidene digoxin (21-BD), activates the Na,K-ATPase rather than cause its inhibition, as its parent compound does. Here, the mechanism behind the unique effects of 21-BD are further explored. In HeLa cancer cells, low (5µM) and high (50µM) doses of 21-BD activated and inhibited the Na,K-ATPase, respectively, without altering the membrane expression of the Na,K-ATPase. While digoxin did not affect HeLa membrane cholesterol or phospholipid content, 50µM 21-BD increased both lipids via a mechanism reliant on an intact cell. Afterwards, the direct action of 21-BD was evaluated on erythrocyte membranes; however, no effect was observed. As CTS may generate reactive oxygen species (ROS) which can affect plasma membrane fluidity and therefore Na,K-ATPase activity, several markers involved in ROS generation were analyzed such as, lipid peroxidation (TBARS), reduced glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD). GSH content and catalase activity were unaffected by digoxin or 21-BD. Surprisingly, TBARS and SOD activity was decreased with digoxin and with 50µM 21-BD. Thus, 21-BD and digoxin altered components involved in ROS generation and inhibition in a similar fashion. This study suggests alterations to the Na,K-ATPase and membrane lipids by 21-BD is not reliant on ROS generation., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The hormone ouabain has been shown to enhance the cystic phenotype of autosomal dominant polycystic kidney disease (ADPKD). Among other characteristics, the ADPKD phenotype includes cell de-differentiation and epithelial to mesenchymal transition (EMT). Here, we determined whether physiological concentrations of ouabain induces EMT in human renal epithelial cells from patients with ADPKD. We found that ADPKD cells respond to ouabain with a decrease in expression of the epithelial marker E-cadherin and increase in the expression of the mesenchymal markers N-cadherin, α smooth muscle actin (αSMA) and collagen-I; and the tight junction protein occludin and claudin-1. Other adhesion molecules, such as ZO-1, β-catenin and vinculin were not significantly modified by ouabain. At the cellular level, ouabain stimulated ADPKD cell migration, reduced cell-cell interaction, and the ability of ADPKD cells to form aggregates. Moreover, ouabain increased the transepithelial electrical resistance of ADPKD cell monolayers, suggesting that the paracellular transport pathway was preserved in the cells. These effects of ouabain were not observed in normal human kidney (NHK) cells. Altogether these results show a novel role for ouabain in ADPKD, inducing changes that lead to a partial EMT phenotype in the cells. These effects further support the key role that ouabain has as a factor that promotes the cystic characteristics of ADPKD cells., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Ouabain and other cardenolides are steroidal compounds originally discovered in plants. Cardenolides were first used as poisons, but after finding their beneficial cardiotonic effects, they were rapidly included in the medical pharmacopeia. The use of cardenolides to treat congestive heart failure remained empirical for centuries and only relatively recently, their mechanisms of action became better understood. A breakthrough came with the discovery that ouabain and other cardenolides exist as endogenous compounds that circulate in the bloodstream of mammals. This elevated these compounds to the category of hormones and opened new lines of investigation directed to further study their biological role. Another important discovery was the finding that the effect of ouabain was mediated not only by inhibition of the activity of the Na,K-ATPase (NKA), but by the unexpected role of NKA as a receptor and a signal transducer, which activates a complex cascade of intracellular second messengers in the cell. This broadened the interest for ouabain and showed that it exerts actions that go beyond its cardiotonic effect. It is now clear that ouabain regulates multiple cell functions, including cell proliferation and hypertrophy, apoptosis, cell adhesion, cell migration, and cell metabolism in a cell and tissue type specific manner. This review article focuses on the cardenolide ouabain and discusses its various in vitro and in vivo effects, its role as an endogenous compound, its mechanisms of action, and its potential use as a therapeutic agent; placing especial emphasis on our findings of ouabain as a pro-cystogenic agent in autosomal dominant polycystic kidney disease (ADPKD).

Progression of autosomal dominant polycystic kidney disease (ADPKD) is highly influenced by factors circulating in blood. We have shown that the hormone ouabain enhances several characteristics of the ADPKD cystic phenotype, including the rate of cell proliferation, fluid secretion and the capacity of the cells to form cysts. In this work, we found that physiological levels of ouabain (3 nM) also promote programmed cell death of renal epithelial cells obtained from kidney cysts of patients with ADPKD (ADPKD cells). This was determined by Alexa Fluor 488 labeled-Annexin-V staining and TUNEL assay, both biochemical markers of apoptosis. Ouabain-induced apoptosis also takes place when ADPKD cell growth is blocked; suggesting that the effect is not secondary to the stimulatory actions of ouabain on cell proliferation. Ouabain alters the expression of BCL family of proteins, reducing BCL-2 and increasing BAX expression levels, anti- and pro-apoptotic mediators respectively. In addition, ouabain caused the release of cytochrome c from mitochondria. Moreover, ouabain activates caspase-3, a key "executioner" caspase in the cell apoptotic pathway, but did not affect caspase-8. This suggests that ouabain triggers ADPKD cell apoptosis by stimulating the intrinsic, but not the extrinsic pathway of programmed cell death. The apoptotic effects of ouabain are specific for ADPKD cells and do not occur in normal human kidney cells (NHK cells). Taken together with our previous observations, these results show that ouabain causes an imbalance in cell growth/death, to favor growth of the cystic cells. This event, characteristic of ADPKD, further suggests the importance of ouabain as a circulating factor that promotes ADPKD progression.

Cyst enlargement in autosomal dominant polycystic kidney disease (ADPKD) requires the transepithelial secretion of fluid into the cyst lumen. We previously showed that physiological amounts of ouabain enhance cAMP-dependent fluid secretion and cyst growth of human ADPKD cyst epithelial cells in culture and formation of cyst-like dilations in metanephric kidneys from Pkd1 mutant mice. Here, we investigated the mechanisms by which ouabain promotes cAMP-dependent fluid secretion and cystogenesis. Ouabain (3 nM) enhanced cAMP-induced cyst-like dilations in embryonic kidneys from Pkd1 (m1Bei) mice, but had no effect on metanephroi from Pkd1 (m1Bei) mice that lack expression of the cystic fibrosis transmembrane conductance regulator (CFTR). Similarly, ouabain stimulation of cAMP-induced fluid secretion and in vitro cyst growth of ADPKD cells were abrogated by CFTR inhibition, showing that CFTR is required for ouabain effects on ADPKD fluid secretion. Moreover, ouabain directly enhanced the cAMP-dependent Cl(-) efflux mediated by CFTR in ADPKD monolayers. Ouabain increased the trafficking of CFTR to the plasma membrane and up-regulated the expression of the CFTR activator PDZK1. Finally, ouabain decreased plasma membrane expression and activity of the Na,K-ATPase in ADPKD cells. Altogether, these results show that ouabain enhances net fluid secretion and cyst formation by activating apical anion secretion via CFTR and decreasing basolateral Na(+) transport via Na,K-ATPase. These results provide new information on the mechanisms by which ouabain affects ADPKD cells and further highlight the importance of ouabain as a non-genomic stimulator of cystogenesis in ADPKD.

Wound healing is a major problem in diabetic patients and current methods of treatment have met with limited success. Since skin cell renewal is under the control of mesenchymal stem cells (MSCs) treatment of wounds has been attempted with the application of exogenous bone marrow MSCs (hBMMSCs). However, hBMMSCs have the limitations of painful harvest, low cell numbers and short-lived stemness properties unlike MSCs from the Wharton's jelly of human umbilical cords (hWJSCs). Since nanoscaffolds provide three dimensional architectural patterns that mimic in vivo stem cell niches and aloe vera has antibacterial properties we evaluated the use of an aloe vera-polycaprolactone (AV/PCL) nanoscaffold impregnated with green fluorescent protein (GFP)-labeled hWJSCs (GFP-hWJSCs + AV/PCL) or its conditioned medium (hWJSC-CM + AV/PCL) for healing of excisional and diabetic wounds. In skin fibroblast scratch-wound assays exposed to GFP-hWJSCs + AV/PCL or hWJSC-CM + AV/PCL, fibroblasts migrated significantly faster from edges of scratches into vacant areas together with increased secretion of collagen I and III, elastin, fibronectin, superoxide dismutase, and metalloproteinase-1 (MMP-1) compared to controls. After one application of GFP-hWJSCs + AV/PCL or hWJSC-CM + AV/PCL excisional and diabetic wounds in mice showed rapid wound closure, reepithelialization, and increased numbers of sebaceous glands and hair follicles compared to controls. The same wounds exposed to GFP-hWJSCs + AV/PCL or hWJSC-CM + AV/PCL also showed positive keratinocyte markers (cytokeratin, involucrin, filaggrin) and increased expression of ICAM-1, TIMP-1, and VEGF-A compared to controls. AV/PCL nanoscaffolds in combination with hWJSCs appear to have synergistic benefits for wound healing., (© 2013 Wiley Periodicals, Inc.)

Mimicking hybrid extracellular matrix is one of the main challenges for bone tissue engineering (BTE). Biocompatible polycaprolactone/poly(α,β)-DL-aspartic acid/collagen nanofibrous scaffolds were fabricated by electrospinning and nanohydroxyapatite (n-HA) was deposited by calcium phosphate dipping method for BTE. Human mesenchymal stem cells (hMSCs) were cultured on these hybrid scaffolds to investigate the cell proliferation, osteogenic differentiation by alkaline phosphatase activity, mineralization, double immunofluorescent staining using CD90 and expression of osteocalcin. The present study indicated that the PCL/PAA/collagen/n-HA scaffolds promoted greater osteogenic differentiation of hMSCs, proving to be a potential hybrid scaffolds for BTE., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A functional scaffold fabricated is developed from natural polymers, favoring regeneration of the ischemic myocardium. Hemoglobin/gelatin/fibrinogen (Hb/gel/fib) nanofibers are fabricated by electrospinning and are characterized for morphology, scaffold composition, functional groups and hydrophilicity. It is hypothesized that ex vivo pretreatment of mesenchymal stem cells (MSCs) using 5-azacytidine and such a functional nanofibrous construct having a high oxygen-carrying potential could lead to enhanced cardiomyogenic differentiation of MSCs and result in superior biological and functional effects. The combination of a functional nanofibrous scaffold composed of natural polymers and crosslinked with a natural crosslinking agent, phytic acid, and stem cell biology may prove to be a novel therapeutic device for treatment of myocardial infarction., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The current treatments used for osteoarthritis from cartilage damage have their disadvantages of donor site morbidity, complicated surgical interventions and risks of infection and graft rejection. Recent advances in tissue engineering have offered much promise in cartilage repair but the best cell source and in vitro system have not as yet been optimised. Human bone marrow mesenchymal stem cells (hBMSCs) have thus far been the cell of choice. However, we derived a unique stem cell from the human umbilical cord Wharton's jelly (hWJSC) that has properties superior to hBMSCs in terms of ready availability, prolonged stemness characteristics in vitro, high proliferation rates, wide multipotency, non-tumorigenicity and tolerance in allogeneic transplantation. We observed enhanced cell attachment, cell proliferation and chondrogenesis of hWJSCs over hBMSCs when grown on PCL/Collagen nanoscaffolds in the presence of a two-stage sequential complex/chondrogenic medium for 21 days. Improvement of these three parameters were confirmed via inverted optics, field emission scanning electron microscopy (FESEM), MTT assay, pellet diameters, Alcian blue histology and staining, glycosaminglycans (GAG) and hyaluronic acid production and expression of key chondrogenic genes (SOX9, Collagen type II, COMP, FMOD) using immunohistochemistry and real-time polymerase chain reaction (qRT-PCR). In separate experiments we demonstrated that the 16 ng/ml of basic fibroblast growth factor (bFGF) present in the complex medium may have contributed to driving chondrogenesis. We conclude that hWJSCs are an attractive stem cell source for inducing chondrogenesis in vitro when grown on nanoscaffolds and exposed sequentially first to complex medium and then followed by chondrogenic medium.

The fracture of bones and large bone defects owing to various traumas or natural ageing is a typical type of tissue malfunction. Surgical treatment frequently requires implantation of a temporary or permanent prosthesis, which is still a challenge for orthopaedic surgeons, especially in the case of large bone defects. Mimicking nanotopography of natural extracellular matrix (ECM) is advantageous for the successful regeneration of damaged tissues or organs. Electrospun nanofibre-based synthetic and natural polymer scaffolds are being explored as a scaffold similar to natural ECM for tissue engineering applications. Nanostructured materials are smaller in size falling, in the 1-100 nm range, and have specific properties and functions related to the size of the natural materials (e.g. hydroxyapatite (HA)). The development of nanofibres with nano-HA has enhanced the scope of fabricating scaffolds to mimic the architecture of natural bone tissue. Nanofibrous substrates supporting adhesion, proliferation, differentiation of cells and HA induce the cells to secrete ECM for mineralization to form bone in bone tissue engineering. Our laboratory (NUSNNI, NUS) has been fabricating a variety of synthetic and natural polymer-based nanofibrous substrates and synthesizing HA for blending and spraying on nanofibres for generating artificial ECM for bone tissue regeneration. The present review is intended to direct the reader's attention to the important subjects of synthetic and natural polymers with HA for bone tissue engineering.

Thiazolyl peptides are a class of highly rigid trimacrocyclic compounds consisting of varying but large numbers of thiazole rings. The need for new antibacterial agents to treat infections caused by resistant bacteria prompted a reinvestigation of this class, leading to the previous isolation of thiazolyl peptides, namely, thiazomycin (5) and thiazomycin A (6), congeners of nocathiacins (1-4). Continued chemical screening led to the isolation of six new thiazolyl peptide congeners (8-13), of which three had truncated structures lacking an indole residue. From these, compound 8 showed activity similar to thiazomycin. Two compounds (9 and 10) showed intermediate activities, and the three truncated compounds (11-13) were essentially inactive. The discovery of the truncated compounds revealed the minimal structural requirements for activity and suggested probable biosynthetic pathways for more advanced compounds. The isolation, structure elucidation, antibacterial activity, and proposed biogenesis of thiazomycins are herein described.

Thiazolyl peptides are a class of rigid macrocyclic compounds richly populated with thiazole rings. They are highly potent antibiotics but none have been advanced to clinic due to poor aqueous solubility. Recent progress in this field prompted a reinvestigation leading to the isolation of a new thiazolyl peptide, thiazomycin, a congener of nocathiacins. Thiazomycin possesses an oxazolidine ring as part of the amino-sugar moiety in contrast to the dimethyl amino group present in nocathiacin I. The presence of the oxazolidine ring provides additional opportunities for chemical modifications that are not possible with other nocathiacins. Thiazomycin is extremely potent against Gram-positive bacteria both in vitro and in vivo. The titer of thiazomycin in the fermentation broth was very low compared to the nocathiacins I and III. The lower titer together with its sandwiched order of elution presented significant challenges in large scale purification of thiazomycin. This problem was resolved by the development of an innovative preferential protonation based one- and/or two-step chromatographic method, which was used for pilot plant scale purifications of thiazomycin. The isolation and structure elucidation of thiazomycin is herein described.

Obesity is characterized by elevated levels of circulating plasminogen activator inhibitor-1 (PAI-1), which contribute towards the development of secondary disorders such as type 2 diabetes mellitus and cardiovascular complications. This increase in plasma PAI-1 levels is attributed to an increase in PAI-1 derived from adipose tissue. This study shows that adipose tissue evolved into a major PAI-1 producing organ by gaining capacity during adipocyte differentiation to respond to inducers of PAI-1 transcription. This is mediated by a decrease in E2F1 protein levels, an increase in pRB levels and a decrease in pRB phosphorylation, all leading to a decrease in levels of free E2F, a known transcriptional repressor of PAI-1. Depletion of E2F1-3 was sufficient for inducers such as insulin to potently induce PAI-1 gene expression in pre-adipocytes. Conversely, forced release of pRB-bound endogenous E2F using cell-penetrating peptides can suppress PAI-1 gene expression in adipocytes. This study describes the novel paradigm of cellular differentiation-associated increase in PAI-1 gene expression which is mediated by a decrease in repressor activity, and describes a way of desensitising terminally differentiated cells to PAI-1 inducing agents by restoring endogenous repressor activity.

Electrospinning is an enabling technology that can architecturally (in terms of geometry, morphology or topography) and biochemically fabricate engineered cellular scaffolds that mimic the native extracellular matrix (ECM). This is especially important and forms one of the essential paradigms in the area of tissue engineering. While biomimesis of the physical dimensions of native ECM's major constituents (eg, collagen) is no longer a fabrication-related challenge in tissue engineering research, conveying bioactivity to electrospun nanofibrous structures will determine the efficiency of utilizing electrospun nanofibers for regenerating biologically functional tissues. This can certainly be achieved through developing composite nanofibers. This article gives a brief overview on the current development and application status of employing electrospun composite nanofibers for constructing biomimetic and bioactive tissue scaffolds. Considering that composites consist of at least two material components and phases, this review details three different configurations of nanofibrous composite structures by using hybridizing basic binary material systems as example. These are components blended composite nanofiber, core-shell structured composite nanofiber, and nanofibrous mingled structure.

Electrospun polymer nanofibres were originally developed for their durability and resistance to all forms of degradation and biodegradation. Some polymer nanofibres are biocompatible and biodegradable and therefore suitable for replacement of structurally or physiologically deficient tissues and organs in humans. Here, biocompatible polycaprolactone (PCL) nanofibre scaffolds modified with collagen types I and III were used for vascular tissue engineering. Coronary artery smooth muscle cells (SMCs) were grown on PCL nanofibres, modified PCL/collagen biocomposite nanofibres and collagen nanofibres. The results show that the modified PCL/collagen biocomposite nanofibre scaffolds provide required mechanical properties for regulation of normal cell function in vascular tissue engineering.

Recent advancements in the electrospinning method enable the production of ultrafine solid and continuous fibers with diameters ranging from a few nanometers to a few hundred nanometers with controlled surface and internal molecular structures. A wide range of biodegradable biopolymers can be electrospun into mats with specific fiber arrangement and structural integrity. Through secondary processing, the nanofiber surface can be functionalized to display specific biochemical characteristics. It is hypothesized that the large surface area of nanofibers with specific surface chemistry facilitates attachment of cells and control of their cellular functions. These features of nanofiber mats are morphologically and chemically similar to the extracellular matrix of natural tissue, which is characterized by a wide range of pore diameter distribution, high porosity, effective mechanical properties, and specific biochemical properties. The current emphasis of research is on exploiting such properties and focusing on determining appropriate conditions for electrospinning various polymers and biopolymers for eventual applications including multifunctional membranes, biomedical structural elements (scaffolds used in tissue engineering, wound dressing, drug delivery, artificial organs, vascular grafts), protective shields in specialty fabrics, and filter media for submicron particles in the separation industry. This has resulted in the recent applications for polymer nanofibers in the field of biomedicine and biotechnology.

Wistar rats treated with alpha-methyl-DL-p-tyrosine methylester showed significant level of inhibition in the activity of Na+, K+ -ATPase, Mg2+ -ATPase and Ca2+ -ATPase enzymes in different regions of the brain. The enzyme activity was assayed in cerebral hemispheres, hypothalamus, thalamus, hippocampus, amygdala and septum at proestrous (12 h), estrous (25 h), metestrous (38 h) and diestrous periods (92 h) of the rat. The Na+, K+ -ATPase activity was significantly inhibited in most of the brain regions after treated with alpha-methyl-DL-p-tyrosine methylester (MPT) and this indicated that MPT affected the active transport system and nerve impulse transmission. Mg2+ -ATPase and Ca2+ -ATPase was also significantly (P < 0.001) reduced in different regions of the brain. The results revealed that MPT affected active transport system and nerve impulse transmission by inhibiting Na+, K+ -ATPase and Ca2+ -ATPase. It has induced energy crisis by inhibiting Mg2+ -ATPase and all these cumulative effects of MPT have adversely affected the female Wistar rats. These effects have been manifested in the form of aberrations in the behavior of MPT treated female rats, which have shown their inability to perform their normal sexual activity.

Plasminogen activator inhibitor-1 (PAI-1) plays an important role in the pathogenesis of obesity-driven type 2 diabetes mellitus and associated cardiovascular complications. Here, we show that perturbation of caveolar microdomains leads to insulin resistance and concomitant up-regulation of PAI-1 in 3T3L1 adipocytes. We present several lines of evidence showing that the phosphatidylinositol 3-kinase (PI3K) pathway negatively regulates PAI-1 gene expression. Insulin-induced PAI-1 gene expression is up-regulated by a specific inhibitor of PI3K. In addition, serum PAI-1 level is elevated in protein kinase Balpha-deficient mice, whereas it is reduced in p70 ribosomal S6 kinase 1-deficient mice. The PI3K pathway phosphorylates retinoblastoma protein (pRB), known to release free E2 (adenoviral protein) factor (E2F), which we have previously demonstrated to be a transcriptional repressor of PAI-1 gene expression. Accordingly, cell-penetrating peptides that disrupt pRB-E2F interaction, and thereby release free E2F, are able to suppress PAI-1 levels that are elevated during insulin-resistant conditions. This study identifies a caveolar-dependent signal pathway that up-regulates PAI-1 in insulin-resistant adipocytes and proposes a previously undescribed pharmacological paradigm of disrupting pRB-E2F interaction to suppress PAI-1 levels.

In recent years, biomedical science has witnessed the emergence of peptide biochemicals as significant topics of research. Some of these peptides are of little potential clinical use, while others, of which cardiac natriuretic peptides are an example, appear to be promising. This particular group of peptides (i.e. ANP, BNP and CNP) shows promising diagnostic as well as therapeutic potential for various pathological conditions. In the case of acute myocardial infarction, these peptides have significant diagnostic and predictive properties, more so than other biochemicals such as adrenaline, renin and aldosterone. In addition, ANP is found to have significant benefits over the classical anti-anginal drug glyceryl trinitrate. However, as is the case with other peptides, applying these benefits clinically may not be easy because of the structure of the compounds, but various strategies are now being applied to solve this problem. These include the use of non-peptide receptor ligands, inhibitors of ANP metabolism, gene therapy and so on. The development of drugs in clinical practice, which exploits the natriuretic peptides system therefore seems to be promising, and this article reviews advances in our understanding of these compounds.

An alkaline endodeoxyribonuclease from rat brain has been purified to near homogeneity. The purified enzyme showed a M.Wt. of 54 Kd on SDS-PAGE and does not require metal ion for activity and thus differs from classical DNase I. No preference towards any particular form of calf thymus DNA (native, denatured, undamaged and damaged by exposure to UV, H2O2 and OsO4 and depurination) was noticed. However, with supercoiled pBR 322 plasmid DNA as substrate, higher activity was exhibited towards UV irradiated and depurinated forms. It is suggested that this DNase may be a 'housekeeping' enzyme to detect any conformational distortion in DNA and initiate excision repair.

The instrumental system assembled consists of video monitors which projects signals from remotely placed video camera in the rat pen with pan and tilt arrangement and all operations are done through control-room. Signals obtained from the camera will pass through the monitor and then fed into VCR system which records the behavioural events. Studies carried out with the above system has revealed that all the characteristic behaviour of gerbils (Meriones hurricane Jerdon) which is significantly superior (P < 0.001) over the direct observation method. The integrated sensing system is an ideal instrumental set up for viewing and recording the behaviour of rodents as well as other animals in the experimental pen throughout the year under varying weather and light conditions.

The activities of RNA polymerase I and II were assayed in nuclei isolated from different regions (cerebral cortex, cerebellum, hypothalamus, hippocampus, corpus striatum and pituitary) of brains from young (10 days), adult (6 months), and old (2 years) rats. The RNA polymerases I and II activities generally increased during maturation, i.e., from 10 days to 6 months of postnatal age and then showed a decrease from 6 months to 2 years of age in all the regions except in cerebral cortex where the RNA polymerase II activity was highest at 10 days but showed a gradual decrease through the lifespan up to 2 years.