High fat diet reveals sex-specific fecal and liver metabolic alterations in C57BL/6J obese mice.

Obesity is a major health concern that poses significant risks for many other diseases, including diabetes, cardiovascular disease, and cancer. Prevalence of these diseases varies by biological sex. This study utilizes a mouse (C57BL/6J) model of obesity to analyze liver and fecal metabolic profiles at various time points of dietary exposure: 5, 9, and 12 months in control or high fat diet (HFD)-exposed mice. Our study discovered that the female HFD group has a more discernable perturbation and set of significant changes in metabolic profiles than the male HFD group. In the female mice, HFD fecal metabolites including pyruvate, aspartate, and glutamate were lower than control diet-exposed mice after both 9th and 12th month exposure time points, while lactate and alanine were significantly downregulated only at the 12th month. Perturbations of liver metabolic profiles were observed in both male and female HFD groups, compared to controls at the 12th month. Overall, the female HFD group showed higher lactate and glutathione levels compared to controls, while the male HFD group showed higher levels of glutamine and taurine compared to controls. These metabolite-based findings in both fecal and liver samples for a diet-induced effect of obesity may help guide future pioneering discoveries relating to the analysis and prevention of obesity in people, especially for females.

Diepoxybutane induces the p53-dependent transactivation of the CCL4 gene that mediates apoptosis in exposed human lymphoblasts.

Diepoxybutane (DEB) is the most toxic metabolite of the environmental chemical 1,3-butadiene. We previously demonstrated the occurrence of DEB-induced p53-mediated apoptosis in human lymphoblasts. The p53 protein functions as a master transcriptional regulator in orchestrating the genomic response to a variety of stress signals. Transcriptomic analysis indicated that C-C chemokine ligand 4 (CCL4) gene expression was elevated in a p53-dependent manner in DEB-exposed p53-proficient TK6 cells, but not in DEB-exposed p53-deficient NH32 cells. Thus, the objective of this study was to determine whether the CCL4 gene is a transcriptional target of p53 and deduce its role in DEB-induced apoptosis in human lymphoblasts. Endogenous and exogenous wild-type p53 transactivated the activity of the CCL4 promoter in DEB-exposed lymphoblasts, but mutant p53 activity on this promoter was reduced by ∼80% under the same experimental conditions. Knockdown of the upregulated CCL4 mRNA levels in p53-proficient TK6 cells inhibited DEB-induced apoptosis by ∼45%-50%. Collectively, these observations demonstrate for the first time that the CCL4 gene is upregulated by wild-type p53 at the transcriptional level, and this upregulation mediates apoptosis in DEB-exposed human lymphoblasts.

Clients' experiences on North America's first take-home injectable opioid agonist treatment (iOAT) program: a qualitative study.

BACKGROUND: To support public health measures during the COVID-19 pandemic, oral opioid agonist treatment (OAT) take-home doses were expanded in Western countries with positive results. Injectable OAT (iOAT) take-home doses were previously not an eligible option, and were made available for the first time in several sites to align with public health measures. Building upon these temporary risk-mitigating guidelines, a clinic in Vancouver, BC continued to offer two of a possible three daily doses of take-home injectable medications to eligible clients. The present study explores the processes through which take-home iOAT doses impacted clients' quality of life and continuity of care in real-life settings. METHODS: Three rounds of semi-structured qualitative interviews were conducted over a period of seventeen months beginning in July 2021 with eleven participants receiving iOAT take-home doses at a community clinic in Vancouver, British Columbia. Interviews followed a topic guide that evolved iteratively in response to emerging lines of inquiry. Interviews were recorded, transcribed, and then coded using NVivo 1.6 using an interpretive description approach. RESULTS: Participants reported that take-home doses granted them the freedom away from the clinic to have daily routines, form plans, and enjoy unstructured time. Participants appreciated the greater privacy, accessibility, and ability to engage in paid work. Furthermore, participants enjoyed greater autonomy to manage their medication and level of engagement with the clinic. These factors contributed to greater quality of life and continuity of care. Participants shared that their dose was too essential to divert and that they felt safe transporting and administering their medication off-site. In the future, all participants would like more accessible treatment such as access longer take-home prescriptions (e.g., one week), the ability to pick-up at different and convenient locations (e.g., community pharmacies), and a medication delivery service. CONCLUSIONS: Reducing the number of daily onsite injections from two or three to only one revealed the diversity of rich and nuanced needs that added flexibility and accessibility in iOAT can meet. Actions such as licencing diverse opioid medications/formulations, medication pick-up at community pharmacies, and a community of practice that supports clinical decisions are necessary to increase take-home iOAT accessibility.

"As long as that place stays open, I'll stay alive": Accessing injectable opioid agonist treatment during dual public health crises.

BACKGROUND: Since the onset of the COVID-19 pandemic, overdose rates in North America have continued to rise, with more than 100,000 drug poisoning deaths in the past year. Amidst an increasingly toxic drug supply, the pandemic disrupted essential substance use treatment and harm reduction services that reduce overdose risk for people who use drugs. In British Columbia, one such treatment is injectable opioid agonist treatment (iOAT), the supervised dispensation of injectable hydromorphone or diacetylmorphine for people with opioid use disorder. While evidence has shown iOAT to be safe and effective, it is intensive and highly regimented, characterized by daily clinic visits and provider-client interaction-treatment components made difficult by the pandemic. METHODS: Between April 2020 and February 2021, we conducted 51 interviews with 18 iOAT clients and two clinic nurses to understand how the pandemic shaped iOAT access and treatment experiences. To analyze interview data, we employed a multi-step, flexible coding strategy, an iterative and abductive approach to analysis, using NVivo software. RESULTS: Qualitative analysis revealed the ways in which the pandemic shaped clients' lives and the provision of iOAT care. First, client narratives illuminated how the pandemic reinforced existing inequities. For example, socioeconomically marginalized clients expressed concerns around their financial stability and economic impacts on their communities. Second, clients with health comorbidities recognized how the pandemic amplified health risks, through potential COVID-19 exposure or by limiting social connection and mental health supports. Third, clients described how the pandemic changed their engagement with the iOAT clinic and medication. For instance, clients noted that physical distancing guidelines and occupancy limits reduced opportunities for social connection with staff and other iOAT clients. However, pandemic policies also created opportunities to adapt treatment in ways that increased patient trust and autonomy, for example through more flexible medication regimens and take-home oral doses. CONCLUSION: Participant narratives underscored the unequal distribution of pandemic impacts for people who use drugs but also highlighted opportunities for more flexible, patient-centered treatment approaches. Across treatment settings, pandemic-era changes that increase client autonomy and ensure equitable access to care are to be continued and expanded, beyond the duration of the pandemic.

Implementation of a nurse-led overdose prevention site in a hospital setting: lessons learned from St. Paul's Hospital, Vancouver, Canada.

OBJECTIVES: In May 2018, St. Paul's Hospital (SPH) in Vancouver (Canada) opened an outdoor peer-led overdose prevention site (OPS) operated in partnership with Vancouver Coastal Health and RainCity Housing. At the end of 2020, the partnered OPS moved to a new location, which created a gap in service for SPH inpatients and outpatients. To address this gap, which was magnified by the COVID-19 pandemic, SPH opened a nurse-led OPS in February 2021. This paper describes the steps leading to the implementation of the nurse-led OPS, its impact, and lessons learned. METHODS: Four steps paved the way for the opening of the OPS: (1) identifying the problem, (2) seeking ethics guidance, (3) adapting policies and practices, and (4) supporting and training staff. RESULTS: The OPS is open between 10:00 and 20:00 and staffed by two nurses per shift. It is accessible to all patients including inpatients, patients in the Emergency Department, and patients attending outpatient services. Between February 1, 2021 and October 23, 2021, the OPS recorded 1612 visits for the purpose of injection, for an average weekly visit number of 42. A total of 46 overdoses were recorded in that 9-month period. Thirty-seven (80%) required administration of naloxone and 12 (26%) required a code blue response. CONCLUSIONS: Due to the unique nature of our OPS, we learned many important lessons in the process leading to the opening of the site and the months that followed. We conclude the paper with lessons learned grouped into six main categories, namely engagement, communication, access, staff education and support, data collection, and safety.

Feasibility, acceptability, concerns, and challenges of implementing supervised injection services at a specialty HIV hospital in Toronto, Canada: perspectives of people living with HIV.

BACKGROUND: Substance use significantly impacts health and healthcare of people living with HIV/AIDS (PLHIV), especially their ability to remain in hospital following admission. Supervised injection services (SIS) reduce overdoses and drug-related harms, but are not often provided within hospitals/outpatient programs. Leading us to question, what are PLHIV's perceptions of hospital-based SIS? METHODS: This mixed-methods study explored feasibility and acceptability of implementing SIS at Casey House, a Toronto-based specialty HIV hospital, from the perspective of its in/outpatient clients. We conducted a survey, examining clients' (n = 92) demand for, and acceptability of, hospital-based SIS. Following this, we hosted two focus groups (n = 14) and one-on-one interviews (n = 8) with clients which explored benefits/drawbacks of in-hospital SIS, wherein participants experienced guided tours of a demonstration SIS space and/or presentations of evidence about impacts of SIS. Data were analysed using descriptive statistics and thematic analysis. RESULTS: Among survey participants, 76.1% (n = 70) identified as cis-male and over half (n = 49;54.4%) had been a hospital client for 2 years or less. Nearly half (48.8%) knew about clients injecting in/near Casey House, while 23.6% witnessed it. Survey participants were more supportive of SIS for inpatients (76.1%) than for outpatients (68.5%); most (74.7%) reported SIS implementation would not impact their level of service use at Casey House, while some predicted coming more often (16.1%) and others less often (9.2%). Most focus group/interview participants, believed SIS would enhance safety by reducing health harms (e.g. overdose), increasing transparency between clients and clinicians about substance use, and helping retain clients in care. Debate arose about who (e.g., in/outpatients vs. non-clients) should have access to hospital-based SIS and how implementation may shift organizational priorities/resources away from services not specific to drug use. CONCLUSIONS: Our data showed widespread support of, and need for, hospital-based SIS among client stakeholders; however, attempts to reduce negative impacts on non-drug using clients need to be considered in the balance of implementation plans. Given the increased risks of morbidity and mortality for PLHIV who inject drugs as well as the problems in retaining them in care in a hospital setting, SIS is a key component of improving care for this marginalized group.

Routine HIV testing in acute care hospitals: Changing practice to curb a local HIV epidemic in Vancouver, BC.

Early treatment of HIV infection increases life expectancy and reduces infectivity; however, delayed HIV diagnosis remains common. Implementation and sustainability of hospital-based routine HIV testing in Vancouver, British Columbia, was evaluated to address a local HIV epidemic by facilitating earlier diagnosis and treatment. Public health issued a recommendation in 2011 to offer HIV testing to all patients presenting to three Vancouver hospitals as part of routine care, including all patients admitted to medical/surgical units with expansion to emergency departments (ED). We evaluated acceptability, feasibility, and effectiveness from 2011 to 2014 and continued monitoring through 2016 for sustainability. Between October 2011-December 2016, 114,803 HIV tests were administered at the three hospitals; an 11-fold increase following implementation of routine testing. The rate of testing was sustained and remained high through 2018. Of those tested, 151 patients were diagnosed with HIV for a testing yield of 0.13%. Review of 12,996 charts demonstrated 4935/5876 (96·9%) of admitted patients agreed to have an HIV test when offered. People diagnosed in hospital were significantly more likely to be diagnosed with acute stage (aOR 1·96, 95% CI 1·19, 3·23) infection, particularly those diagnosed in the ED. This study provides practice-based evidence of the feasibility, acceptability, and effectiveness of implementing a recommendation for routine HIV testing among inpatient and emergency department admissions, as well as the ability to normalize and sustain this change. Routine hospital-based HIV testing can increase diagnoses of acute HIV infection and facilitate earlier initiation of antiretroviral treatment.

Diepoxybutane induces the expression of a novel p53-target gene XCL1 that mediates apoptosis in exposed human lymphoblasts.

Diepoxybutane (DEB) is the most potent active metabolite of the environmental chemical 1,3-butadiene (BD). BD is a human carcinogen that exhibits multiorgan systems toxicity. Our previous studies demonstrated that the X-C motif chemokine ligand 1 (XCL1) gene expression was upregulated 3.3-fold in a p53-dependent manner in TK6 lymphoblasts undergoing DEB-induced apoptosis. The tumor-suppressor p53 protein is a transcription factor that regulates a wide variety of cellular processes, including apoptosis, through its various target genes. Thus, the objective of this study was to determine whether XCL1 is a novel direct p53 transcriptional target gene and deduce its role in DEB-induced toxicity in human lymphoblasts. We utilized the bioinformatics tool p53scan to search for known p53 consensus sequences within the XCL1 promoter region. The XCL1 gene promoter region was found to contain the p53 consensus sequences 5'-AGACATGCCTAGACATGCCT-3' at three positions relative to the transcription start site (TSS). Furthermore, the XCL1 promoter region was found, through reporter gene assays, to be transactivated at least threefold by wild-type p53 promoter in DEB-exposed human lymphoblasts. Inactivation of the XCL1 promoter p53-binding motif located at -2.579 kb relative to TSS reduced the transactivation function of p53 on this promoter in DEB-exposed cells by 97%. Finally, knockdown of XCL1 messenger RNA with specific small interfering RNA inhibited DEB-induced apoptosis in human lymphoblasts by 50%. These observations demonstrate, for the first time, that XCL1 is a novel DEB-induced direct p53 transcriptional target gene that mediates apoptosis in DEB-exposed human lymphoblasts.

Microbial community dynamics during anaerobic co-digestion of corn stover and swine manure at different solid content, carbon to nitrogen ratio and effluent volumetric percentages.

The methane production and the microbial community dynamics of thermophilic anaerobic co-digestion (AD) of corn stover, swine manure and effluent were conducted at total solid (TS) content of 5%, 10% and 15%, the carbon to nitrogen ratio (C/N) of 20, 30 and 40 and the effluent volumetric percentage (EVP) of 20%, 40% and 60%. For batches with 5% TS, the highest methane yield of 238.5-283.1 mL g-1 volatile solid (VS) and the specific methane productivity of 138.5-152.2 mL g-1 initial VS were obtained at the C/N ratios of 20 and 30. For the mixtures with 10% and 15% TS, the highest methane yield was 341.9 mL g-1 VS and 351.2 mL g-1 VS, respectively, when the C/N ratio of 20% and 60% EVP conditions were maintained. Co-digestion of swine manure with corn stover caused an obvious shift in microbial population, in which the archaeal population changed from 0.3% to 2.8% and the bacterial community changed from 97.2% to 99.7%. The experimental batches with the highest relative abundance of the archaeal population (2.00% of total microbial population for 5% TS, 1.74% for 10% TS and 2.76% for 15% TS) had the highest rate of methanogenesis subsequently enhancing methane production (283.08 mL g-1 VS for 5% TS, 341.91 mL g-1 VS for 10% TS and 351.23 mL g-1 VS for 15% TS). The results of microbiome analysis enabled understanding the key populations in biomethane generation.

Predictable tuning of protein expression in bacteria.

We comprehensively assessed the contribution of the Shine-Dalgarno sequence to protein expression and used the data to develop EMOPEC (Empirical Model and Oligos for Protein Expression Changes; http://emopec.biosustain.dtu.dk). EMOPEC is a free tool that makes it possible to modulate the expression level of any Escherichia coli gene by changing only a few bases. Measured protein levels for 91% of our designed sequences were within twofold of the desired target level.

Functional mining of transporters using synthetic selections.

Only 25% of bacterial membrane transporters have functional annotation owing to the difficulty of experimental study and of accurate prediction of their function. Here we report a sequence-independent method for high-throughput mining of novel transporters. The method is based on ligand-responsive biosensor systems that enable selective growth of cells only if they encode a ligand-specific importer. We developed such a synthetic selection system for thiamine pyrophosphate and mined soil and gut metagenomes for thiamine-uptake functions. We identified several members of a novel class of thiamine transporters, PnuT, which is widely distributed across multiple bacterial phyla. We demonstrate that with modular replacement of the biosensor, we could expand our method to xanthine and identify xanthine permeases from gut and soil metagenomes. Our results demonstrate how synthetic-biology approaches can effectively be deployed to functionally mine metagenomes and elucidate sequence-function relationships of small-molecule transport systems in bacteria.

The identification of risk factors associated with patient and healthcare system delays in the treatment of tuberculosis in Tabriz, Iran.

BACKGROUND: Tuberculosis (TB) is a serious health concern, particularly in developing countries. Various delays, such as patient delay (PD) and healthcare system delay (HSD) in the TB process, are exacerbating the disease burden and increasing the rates of transmission and mortality in various global communities. Therefore, the aim of this study is to identify risk factors associated with PD and HSD in TB patients in Tabriz, Iran. METHODS: A cross-sectional study was conducted on 173 TB patients in Tabriz, Iran from 2012 to 2014. Patients were interviewed with a semi-structured questionnaire. Frequencies and percentages were reported for patient categories of sex, age, and education. The median and interquartile range (IQR) were reported for the time intervals of delays. Univariate and multivariate logistic regressions of delay in respect to socio-demographic and clinical variables were performed. Statistical significance was set at p < 0.05. RESULTS: The median values for delays were 53 days for HSD (IQR = 73) and 13 days for PD (IQR = 57). Odds ratios (OR) associated with PD were: employed vs. unemployed (OR = 5.86, 95% CI: 1.59 to 21.64); public hospitals vs. private hospitals (OR = 2.64, 95% CI: 1.01 to 6.85); ≥ 3 vs. < 3 visits to health facilities before correct diagnosis (OR = 2.35, 95% CI: 1.08 to 5.11); and male vs. female (OR = 2.28, 95% CI: 1.29 to 4.39). The OR associated with HSD were: ≥ 3 vs. < 3 visits to health facilities before correct diagnosis (OR = 9.44, 95% CI: 4.50 to 19.82), without vs. with access to TB diagnostic services (OR = 3.56, 95% CI: 1.85 to 6.83), and misdiagnosis as cold or viral infection vs. not (OR = 2.62, 95% CI: 1.40 to 4.91). CONCLUSIONS: The results provide for an important understanding of the risk factors associated with PD and HSD. One of the major recommendations is to provide more TB diagnostic knowledge and tools to primary health providers and correct diagnoses for patients during their initial visit to the health care facilities. The knowledge generated from this study will be helpful for prioritizing and developing strategies for minimizing delays, initiating early treatment to TB patients, and improving TB-related training programs and healthcare systems in Tabriz, Iran.

De-bugging and maximizing plant cytochrome P450 production in Escherichia coli with C-terminal GFP fusions.

Cytochromes P450 (CYP) are attractive enzyme targets in biotechnology as they catalyze stereospecific C-hydroxylations of complex core skeletons at positions that typically are difficult to access by chemical synthesis. Membrane bound CYPs are involved in nearly all plant pathways leading to the formation of high-value compounds. In the present study, we systematically maximize the heterologous expression of six different plant-derived CYP genes in Escherichia coli, using a workflow based on C-terminal fusions to the green fluorescent protein. The six genes can be over-expressed in both K- and B-type E. coli strains using standard growth media. Furthermore, sequences encoding a small synthetic peptide and a small bacterial membrane anchor markedly enhance the expression of all six genes. For one of the CYPs, the length of the linker region between the predicted N-terminal transmembrane segment and the soluble domain is modified, in order to verify the importance of this region for enzymatic activity. The work describes how membrane bound CYPs are optimally produced in E. coli and thus adds this plant multi-membered key enzyme family to the toolbox for bacterial cell factory design.

The Role of Gender in Suicidal Ideation among Long-term Opioid Users.

OBJECTIVE: This study aims to examine factors associated with suicidal ideation among people with opioid dependence and to explore whether these factors are gender-specific. METHODS: Cross-sectional data were collected among long-term opioid-dependent individuals ( n = 176; 46.0% women). Lifetime histories of suicidal ideation were measured using the Composite International Diagnostic Interview, and additional data were collected regarding sociodemographic characteristics, drug use, health, and adverse life events. Multivariable logistic regression was used to determine the relationships between these variables and suicidal ideation for the full study sample and separately for women and men to explore the potential role of gender. RESULTS: A total of 43.8% ( n = 77) of participants reported a lifetime history of suicidal ideation. Among those with suicidal ideation, 49.3% were women and the overall average age of first ideation was 19.82 years (SD, 11.66 years). Results from multivariable analyses showed that a history of depression, anxiety, and childhood emotional neglect and the number of lifetime traumatic events were significantly associated with higher odds of suicidal ideation. The gender-based analysis suggested that histories of depression and anxiety remained independently associated with lifetime suicidal ideation among women, whereas for men, childhood emotional neglect and the number of lifetime potentially traumatic events were independently associated with lifetime suicidal ideation. CONCLUSIONS: This study offers a critical first step to understanding factors associated with suicidal ideation among long-term opioid-dependent men and women and the potential importance of gender-sensitive approaches for suicidal behavior interventions. These data inform further research and clinical opportunities aiming to better respond to the psychological health needs of this population.

EVALUATION OF HUSBANDRY AND MORTALITY IN LESSER HEDGEHOG TENRECS (ECHINOPS TELFAIRI).

Causes of morbidity and mortality for various species of tenrecs have not been widely published, aside from several reports of neoplasia, and these data are crucial for advancing objectives for preventive medicine, diagnosis, and treatment. A survey on husbandry, morbidity, and mortality of lesser hedgehog tenrecs ( Echinops telfairi ) in Association of Zoos and Aquariums (AZA) institutions was conducted. Out of 32 institutions, 20 responded with data for 98 living and 93 dead animals. The most common causes of mortality among the dead animals were neoplasia (24%), hepatic lipidosis (11%), septicemia (8.6%), pneumonia (8.6%), cardiomyopathy (7.5%), renal disease (6.5%), osteomyelitis (3.2%), and trauma (3.2%). There was no statistically significant correlation between sex and neoplasia. Data about educational usage were specifically provided by survey respondents for 50 of the tenrecs, with only 42% being excluded from educational programming. Tenrecs are common to many AZA institutions as both educational and exhibit animals, and this study provides a helpful reference for expected health problems and highlights the need for future investments into medical diagnosis and treatment for these animals.

Identified metabolic signature for assessing red blood cell unit quality is associated with endothelial damage markers and clinical outcomes.

BACKGROUND: There has been interest in determining whether older red blood cell (RBC) units have negative clinical effects. Numerous observational studies have shown that older RBC units are an independent factor for patient mortality. However, recently published randomized clinical trials have shown no difference of clinical outcome for patients receiving old or fresh RBCs. An overlooked but essential issue in assessing RBC unit quality and ultimately designing the necessary clinical trials is a metric for what constitutes an old or fresh RBC unit. STUDY DESIGN AND METHODS: Twenty RBC units were profiled using quantitative metabolomics over 42 days of storage in SAGM with 3- to 4-day time intervals. Metabolic pathway usage during storage was assessed using systems biology methods. The detected time intervals of the metabolic states were compared to clinical outcomes. RESULTS: Using multivariate statistics, we identified a nonlinear decay process exhibiting three distinct metabolic states (Days 0-10, 10-17, and 17-42). Hematologic variables traditionally measured in the transfusion setting (e.g., pH, hemolysis, RBC indices) did not distinguish these three states. Systemic changes in pathway usage occurred between the three states, with key pathways changing in both magnitude and direction. Finally, an association was found between the time periods of the metabolic states with the clinical outcomes of more than 280,000 patients in the country of Denmark transfused over the past 15 years and endothelial damage markers in healthy volunteers undergoing autologous transfusions. CONCLUSION: The state of RBC metabolism may be a better indicator of cellular quality than traditional hematologic variables.

Synthesis and optimization of N-heterocyclic pyridinones as catechol-O-methyltransferase (COMT) inhibitors.

A series of N-heterocyclic pyridinone catechol-O-methyltransferase (COMT) inhibitors were synthesized. Physicochemical properties, including ligand lipophilic efficiency (LLE) and clogP, were used to guide compound design and attempt to improve inhibitor pharmacokinetics. Incorporation of heterocyclic central rings provided improvements in physicochemical parameters but did not significantly reduce in vitro or in vivo clearance. Nevertheless, compound 11 was identified as a potent inhibitor with sufficient in vivo exposure to significantly affect the dopamine metabolites homovanillic acid (HVA) and dihydroxyphenylacetic acid (DOPAC), and indicate central COMT inhibition.

Computationally Optimizing the Compliance of a Biopolymer Based Tissue Engineered Vascular Graft.

Coronary heart disease is a leading cause of death among Americans for which coronary artery bypass graft (CABG) surgery is a standard surgical treatment. The success of CABG surgery is impaired by a compliance mismatch between vascular grafts and native vessels. Tissue engineered vascular grafts (TEVGs) have the potential to be compliance matched and thereby reduce the risk of graft failure. Glutaraldehyde (GLUT) vapor-crosslinked gelatin/fibrinogen constructs were fabricated and mechanically tested in a previous study by our research group at 2, 8, and 24 hrs of GLUT vapor exposure. The current study details a computational method that was developed to predict the material properties of our constructs for crosslinking times between 2 and 24 hrs by interpolating the 2, 8, and 24 hrs crosslinking time data. matlab and abaqus were used to determine the optimal combination of fabrication parameters to produce a compliance matched construct. The validity of the method was tested by creating a 16-hr crosslinked construct of 130 µm thickness and comparing its compliance to that predicted by the optimization algorithm. The predicted compliance of the 16-hr construct was 0.00059 mm Hg-1 while the experimentally determined compliance was 0.00065 mm Hg-1, a relative difference of 9.2%. Prior data in our laboratory has shown the compliance of the left anterior descending porcine coronary (LADC) artery to be 0.00071 ± 0.0003 mm Hg-1. Our optimization algorithm predicts that a 258-µm-thick construct that is GLUT vapor crosslinked for 8.1 hrs would match LADC compliance. This result is consistent with our previous work demonstrating that an 8-hr GLUT vapor crosslinked construct produces a compliance that is not significantly different from a porcine coronary LADC.

Factors Associated with Perceived Abuse in the Health Care System Among Long-Term Opioid Users: A Cross-Sectional Study.

BACKGROUND: Opioid-dependence is a chronic relapsing disorder. Histories of physical, sexual, and emotional abuse are prevalent among long-term opioid users. While perceived abuse in health care has been linked to histories of abuse in other populations it has not been investigated among long-term opioid users. OBJECTIVE: To determine factors associated with perceived abuse in health care among a sample of long-term opioid users. METHODS: Gender Matters in the Health of Long-Term Opioid Users (GeMa) was a descriptive cross-sectional study. Participants (n = 175) answered questions on health, drug use, treatment history, and victimization. A multivariable model of perceived abuse in health care was built using logistic regression. RESULTS: Half of participants (n = 88) reported perceived abuse in health care in lifetime with no gender differences. Histories of abuse, physical, and psychological health problems, and health care access were more prevalent among those reporting perceived abuse in health care compared to those not reporting such experiences. Multivariable analysis showed that more methadone maintenance treatment attempts in life, prescribed psychiatric medication in life, and having higher childhood emotional abuse scores were independently associated with perceived abuse in health care. Among all childhood neglect and abuse types measured, emotional abuse was the only significant predictor. CONCLUSIONS: A high prevalence of lifetime perceived abuse in health care (50%) was reported, along with extremely high childhood abuse and neglect scores. Consideration of these variables by health care and service providers is extremely important to improving patient perceptions of care, and ultimately health and treatment outcomes among opioid-dependent people.

Assembly of a novel biosynthetic pathway for production of the plant flavonoid fisetin in Escherichia coli.

Plant secondary metabolites are an underutilized pool of bioactive molecules for applications in the food, pharma and nutritional industries. One such molecule is fisetin, which is present in many fruits and vegetables and has several potential health benefits, including anti-cancer, anti-viral and anti-aging activity. Moreover, fisetin has recently been shown to prevent Alzheimer's disease in mice and to prevent complications associated with diabetes type I. Thus far the biosynthetic pathway of fisetin in plants remains elusive. Here, we present the heterologous assembly of a novel fisetin pathway in Escherichia coli. We propose a novel biosynthetic pathway from the amino acid, tyrosine, utilizing nine heterologous enzymes. The pathway proceeds via the synthesis of two flavanones never produced in microorganisms before--garbanzol and resokaempferol. We show for the first time a functional biosynthetic pathway and establish E. coli as a microbial platform strain for the production of fisetin and related flavonols.