Films based on the biopolymer poly(3-hydroxybutyrate) as platforms for the controlled release of dexamethasone

Controlled drug delivery aims to achieve an effective drug concentration in the action site for a desired period of time, while minimizing side effects. In this contribution, biodegradable poly(3-hydroxybutyrate) films were evaluated as a reservoir platform for dexamethasone controlled release. These systems were morphological and physicochemically characterized. In vitro release assays were performed for five different percentages of drug in the films and data were fitted by a mathematical model developed and validated by our research group. When the profiles were normalized, a single curve properly fitted all the experimental data. Using this unique curve, the dissolution efficiency (DE), the time to release a given amount of drug (t_X%), and the mean dissolution time were calculated. Furthermore, the dissolution rate, the initial dissolution rate (a%) and the intrinsic dissolution rate were determined. The a% mean value was 1.968 × 10^?2% released/min, t_80% was about 14 days, and the DE was 59.6% at 14 days and 66.5% at 20 days. After 2 days, when approximately 40% of the drug was released, the dissolution rate decreased about 60% respect to the initial value. The poly(3-hydroxybutyrate) platforms behaved as an appropriate system to release and control the dexamethasone delivery, suggesting that they could be an alternative to improve drug therapy.     

Rapid and efficient identification of cysteine-rich peptides by random screening of a venom gland cDNA library from the hexathelid spider Macrothele gigas.

We identified novel 10 multi-cysteine peptides, namely Magi 7-16, from the spider Macrothele gigas by simple random cDNA screening of the venom gland. Mass analysis of the crude venom detected the mass numbers of the cross-linked forms of all peptides, confirming their presence in the venom. Magi 11, a C-terminus amidated peptide, was chemically synthesized and was indistinguishable from the native peptide proving the feasibility of the method for peptide identification. Moreover, toxicological assays showed diverse lethal or paralytic activities of these peptide toxins on mice and/or insects.     

Enhancing Stewardship of Community-Engaged Research Through Governance

Objectives. We explored the relationship of community-engaged research final approval type (tribal government, health board, or public health office (TG/HB); agency staff or advisory board; or individual or no community approval) with governance processes, productivity, and perceived outcomes.Methods. We identified 294 federally funded community-engaged research projects in 2009 from the National Institutes of Health’s Research Portfolio Online Reporting Tools, Centers for Disease Control and Prevention’s Prevention Research Centers, and Native American Research Centers for Health databases. Two hundred (68.0%) investigators completed a survey about governance processes and productivity measures; 312 partners (77.2% of 404 invited) and 138 investigators (69.0% of 200 invited) completed a survey about perceived outcomes.Results. Projects with TG/HB approval had increased likelihood of community control of resources (odds ratios [ORs] ≥ 4.80). Projects with other approvals had decreased likelihood of development or revision of institutional review board policies (ORs ≤ 0.37), having written agreements (ORs ≤ 0.17), and agreements about publishing (ORs ≤ 0.28), data use (ORs ≤ 0.17), and publishing approval (ORs ≤ 0.14).Conclusions. Community-engaged research projects with TG/HB approval had strong stewardship of project resources and agreements. Governance as stewardship protects community interests; thus, is an ethical imperative for communities, especially native communities, to adopt.Researchers working with native communities (American Indian, Alaska Native, and Native Hawaiian peoples), other racial/ethnic minority communities, or other communities facing disparities that experience similar mistrust for past research issues, health inequities (e.g., gays and lesbians or people with disabilities), or both, have advocated the use of participatory research to enhance community health.1–6 Such approaches include tribal participatory research, community-based participatory research, and participatory action research and are generally grouped as community-engaged research (CEnR). There is a continuum of engagement,7 but CEnR that involves collaborative partnership and shared leadership between community members and (academic) researchers in all phases of the research can build capacity of all partners, create research that benefits the community, and enhance translation of research findings to the community.8–13 These approaches have attraction because they can advance cocreation of the research, contribute culturally centered methods, and foster research capacity.1,2,14,15Although CEnR approaches have appeal, they still require governance to provide protection, oversight, guidance, legitimacy, and community benefit. Governance over CEnR is complex and involves numerous practices and policies.16,17 Historically, oversight responsibilities have been held by institutional review boards (IRBs) that uphold federal standards established by the Office for Human Research Protections.18,19 Use of IRBs (e.g., university IRBs or Indian Health Service IRBs) for research oversight characterizes governance as regulation as the focus is on balancing the needs of protection of individuals from harm while trying to foster scientific innovation. However, when research partners consider other functions of governance alongside legal regulation (e.g., use of tribal governments or community-based review boards), the quality of research can be strengthened and more attention paid to the benefits and harm of the research for the community.20–22In recent years, policymakers, CEnR researchers, and community organizations have advocated a broader perspective of governance, one that can be characterized as stewardship of research. Governance as stewardship enhances protection of the community, helps to foster research partnerships and appropriate access to and approval of research by community bodies, ensures benefit for the community, provides legitimacy of the research, shares responsibility for the research, provides community control, and builds research capacity in communities.20–23 For example, when native communities steward research, new patterns emerge between academic and community partners that might involve (1) community and academic partners requiring and committing to oversight by a tribal council or community board, (2) review boards or tribal governments insisting the that project demonstrate benefits to the community (not just individuals), (3) all partners committing to tribal ownership of the data, and (4) all partners working to use data and disseminate findings following tribal review.2,24–27Although nontribal communities do not have a tribal council for formal governance, they establish various governance mechanisms such as oversight by faith-based networks or leaders, health boards or public health offices, project advisory boards, or community partner boards.21,28–30 Stewardship by these governing entities may involve (1) academic partners that engage in collaboration with the community to produce the research, (2) projects that use culturally relevant research designs and instruments to enhance the quality of the research, (3) projects that hire community members on research projects to build research capacity, and (4) academic partners that encourage community engagement and participation.2–4,21,28 In both native and nonnative communities, stewardship practices lead to enhanced trust of the research process by community partners, relationships that balance community and academic institutional power, IRB processes that reflect community interests and not just biomedical interests, inclusion of cultural frameworks that fit the community, and academic members committed to community engagement.21,28,31Enhancing stewardship of research through governance has focused on several activities. First, increasingly, native and nonnative communities are asserting their roles in overseeing research by developing community IRBs and other forms of research oversight.23,32,33 Second, research review can protect community knowledge by establishing protocols for oversight and can affirm tribal or community authority to approve and guide research that will benefit the community.21,22,28–30,33,34 Third, the National Congress of American Indians35–37 asserts that tribes, as sovereign nations, have regulatory authority over research that takes place on tribal lands and with tribal citizens. Several tribes have exercised governance by establishing research codes, research review boards, and formal agreements with research institutions, and some intertribal entities have established research oversight in urban and cross-tribal regions.33,38Despite the expanded view of ethical issues within CEnR projects and an upsurge in community governance expectations from communities and some funders, there has been little research that has examined the role of governance in research specifically, as well as concerns that these processes might inhibit research. Some researchers and policy analysts suggest that tribal research review is perceived as slowing or blocking research development and dissemination.25,35 A tension related to data ownership to ensure risks and benefits are considered for communities, individual research participants, and research funders also exists.What has been lacking in these discussions to date has been research about the associations of governance with agreements, control of resources, productivity, and perceived outcomes of CEnR. Agreements are the accepted standards or protocols for the research partnership such as mission and objectives, group dynamics, and dissemination.12,39 Control of resources is whether the community, academic institution, or both hire personnel and manage project resources.12,40 Research productivity measures include garnering funding, disseminating scholarship, developing new measures centered in cultural or community perspectives, and establishing new research regulation.3,23,28,30 These measures are important as the need to generate, disseminate, and regulate new knowledge and practices are core goals of funding agencies and, to a lesser extent, communities.Perceived outcomes of CEnR focus on the contributions to health, and encompass changes in power relations, sustainability, community transformation, improved health of the community, and capacity building for individuals and agencies.12 These outcomes are important as they are health outcomes or factors that enhance public health. Ultimately, the success of a CEnR project is determined by research productivity and improvement of health outcomes.The notion of governance also has often been a source of mystery and conflict in research partnerships. We sought to foster understanding and provide context around governance as “stewardship” in research partnerships in both native and nonnative communities by focusing on the type of final approval of CEnR—the body or individual who endorsed and approved the project on behalf of the community and allowed it to continue. This approval is a key factor for legitimacy, community involvement, oversight, and guidance of the project.26,35 Furthermore, the type of approval has not been studied, whereas the general oversight of research ethics through community or tribal IRBs has garnered recent research focus.21,33,38 Examining the type of approval allows an exploration of how governance as stewardship balances needs for authority and accountability, control and capacity building, and protection and benefits.     

Thiol oxidation by nitrosative stress: Cellular localization in human spermatozoa

Peroxynitrite is a highly reactive nitrogen species and when it is generated at high levels it causes nitrosative stress, an important cause of impaired sperm function. High levels of peroxynitrite have been shown to correlate with decreased semen quality in infertile men. Thiol groups in sperm are mainly found in enzymes, antioxidant molecules, and structural proteins in the axoneme. Peroxynitrite primarily reacts with thiol groups of cysteine-containing proteins. Although it is well known that peroxynitrite oxidizes sulfhydryl groups in sperm, the subcellular localization of this oxidation remains unknown. The main objective of this study was to establish the subcellular localization of peroxynitrite-induced nitrosative stress in thiol groups and its relation to sperm motility in human spermatozoa. For this purpose, spermatozoa from healthy donors were exposed in vitro to 3-morpholinosydnonimine (SIN-1), a compound which generates peroxynitrite. In order to detect peroxynitrite and reduced thiol groups, the fluorescent probes, dihydrorhodamine 123 and monobromobimane (mBBr), were used respectively. Sperm viability was analyzed by propidium iodide staining. Peroxynitrite generation and thiol redox state were monitored by confocal microscopy whereas sperm viability was evaluated by flow cytometry. Sperm motility was analyzed by CASA using the ISAS^® system. The results showed that exposure of human spermatozoa to peroxynitrite results in increased thiol oxidation which is mainly localized in the sperm head and principal piece regions. Thiol oxidation was associated with motility loss. The high susceptibility of thiol groups to peroxynitrite-induced oxidation could explain, at least in part, the negative effect of reactive nitrogen species on sperm motility.

Abbreviations: DHR: dihydrorhodamine 123; mBBr: monobromobimane ONOO^?: peroxynitrite RNS: reactive nitrogen species RFI: relative fluorescence intensity SIN-1: 3-morpholinosydnonimine CASA: Computer-Aided Sperm Analysis PARP: poli ADP ribose polimerasa VCL: curvilinear velocity VSL: straight-line velocity VAP: average path velocity PRDXs: peroxiredoxins ODF: outer dense fiber ODF1: outer dense fiber 1 PI: propidium iodide DMSO: dimethyl sulfoxide SD: standard deviation ANOVA: analysis of variance     

Vascular Reactivity Profile of Novel KCa3.1‐Selective Positive‐Gating Modulators in the Coronary Vascular Bed

Opening of intermediate‐conductance calcium‐activated potassium channels (K_Ca3.1) produces membrane hyperpolarization in the vascular endothelium. Here, we studied the ability of two new K_Ca3.1‐selective positive‐gating modulators, SKA‐111 and SKA‐121, to (1) evoke porcine endothelial cell K_Ca3.1 membrane hyperpolarization, (2) induce endothelium‐dependent and, particularly, endothelium‐derived hyperpolarization (EDH)‐type relaxation in porcine coronary arteries (PCA) and (3) influence coronary artery tone in isolated rat hearts. In whole‐cell patch‐clamp experiments on endothelial cells of PCA (PCAEC), K_Ca currents evoked by bradykinin (BK) were potentiated ≈7‐fold by either SKA‐111 or SKA‐121 (both at 1 μM) and were blocked by a K_Ca3.1 blocker, TRAM‐34. In membrane potential measurements, SKA‐111 and SKA‐121 augmented bradykinin‐induced hyperpolarization. Isometric tension measurements in large‐ and small‐calibre PCA showed that SKA‐111 and SKA‐121 potentiated endothelium‐dependent relaxation with intact NO synthesis and EDH‐type relaxation to BK by ≈2‐fold. Potentiation of the BK response was prevented by K_Ca3.1 inhibition. In Langendorff‐perfused rat hearts, SKA‐111 potentiated coronary vasodilation elicited by BK. In conclusion, our data show that positive‐gating modulation of K_Ca3.1 channels improves BK‐induced membrane hyperpolarization and endothelium‐dependent relaxation in small and large PCA as well as in the coronary circulation of rats. Positive‐gating modulators of K_Ca3.1 could be therapeutically useful to improve coronary blood flow and counteract impaired coronary endothelial dysfunction in cardiovascular disease.     

Resveratrol, a polyphenol found in grapes, suppresses oxidative damage and stimulates apoptosis during early colonic inflammation in rats

Oxidative stress, neutrophil infiltration, proinflammatory cytokines and eicosanoid generation are clearly involved in the pathogenesis of intestinal bowel disease. Resveratrol, a polyphenolic compound found in grapes and wine, has been shown to have anti-inflammatory, antioxidant, antitumour and immunomodulatory activities, however, its effects on experimental colitis remain unknown. We have investigated the effects of resveratrol on the colon injury caused by intracolonic instillation of trinitrobenzenesulphonic acid (TNBS) in rats. We determined the production of prostaglandin (PG)E(2) and PGD(2) in colon mucosa and the expression of cyclo-oxygenases (COX)-1 and -2 immunohistochemically. The inflammatory response was assessed by histology and myeloperoxidase activity, as an index of neutrophil infiltration. Interleukin-1 beta production, histological and histochemical analysis of the lesions were also carried out. Finally, since resveratrol has been found to modulate apoptosis we intended to elucidate its effects on colonic mucosa under early acute inflammatory conditions. Resveratrol (5-10mg/kg/day) significantly reduced the degree of colonic injury, the index of neutrophil infiltration and the levels of the cytokine. Resveratrol did not revert the increased PGE(2) levels but produced a significant fall in the PGD(2) concentration. Compared with inflamed colon, no changes in staining for COX-1 were observed in colon of resveratrol and TNBS-treated rats. In contrast, COX-2 expression was decreased. Furthermore, resveratrol enhanced apoptosis compared with already high level induced by TNBS. In conclusion, resveratrol reduces the damage in experimentally induced colitis, alleviates the oxidative events and stimulates apoptosis.     

Accessing Primary Care: HIV+ Caribbean Immigrants in the Bronx

This article describes an ecology of health seeking behavior among Bronx residing HIV+ Caribbean immigrants participating in an arm of a U.S. government-funded multi-site evaluation of peer services in the utilization of HIV primary care. Standardized repeat measures were administered at baseline and three four-month intervals. Clinical markers were obtained through medical chart review. Additionally, local data included ethnographic interviews, focus groups, and progress notes. Clinical outcomes were positive for the 55 subjects, 23 of whom were undocumented. Alienation from family, women’s vulnerability to family violence, and difficulties with disclosure, employment, and health care were compounded by undocumented immigration status. Retention was encouraged by the community based site, high levels of peer interaction, and supportive services. Without consideration of broader contexts, peer driven interventions are potentially limited and the realities of immigrant health care are misunderstood through lack of recognition of competing needs.     

Household Food Insecurity,Lung Function,and COPD in US Adults

Increasing epidemiological evidence suggests that optimal diet quality helps to improve preservation of lung function and to reduce chronic obstructive pulmonary disease (COPD) risk, but no study has investigated the association of food insecurity (FI) and lung health in the general population. Using data from a representative sample of US adults who participated in the National Health and Nutrition Examination Survey (NHANES) 2007–2012 cycles, we investigated the association between FI with lung function and spirometrically defined COPD in 12,469 individuals aged ≥ 18 years of age. FI (high vs. low) was defined using the US Department of Agriculture’s Food Security Scale). Population-weighted adjusted regression models were used to investigate associations between FI, and forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), their ratio, and spirometrically defined restriction (FVC below the lower limit of normal) and airflow obstruction (COPD). The prevalence of household FI was 13.2%. High household FI was associated with lower FVC (adjusted β-coefficient −70.9 mL, 95% CI −116.6, −25.3), and with higher odds (OR) of spirometric restriction (1.02, 95% CI 1.00, 1.03). Stratified analyses showed similar effect sizes within specific ethnic groups. High FI was associated with worse lung health in a nationally representative sample of adults in the US.