Cost of start-up activities to implement a community-level opioid overdose reduction intervention in the HEALing Communities Study.

BACKGROUND: Communities That HEAL (CTH) is a novel, data-driven community-engaged intervention designed to reduce opioid overdose deaths by increasing community engagement, adoption of an integrated set of evidence-based practices, and delivering a communications campaign across healthcare, behavioral-health, criminal-legal, and other community-based settings. The implementation of such a complex initiative requires up-front investments of time and other expenditures (i.e., start-up costs). Despite the importance of these start-up costs in investment decisions to stakeholders, they are typically excluded from cost-effectiveness analyses. The objective of this study is to report a detailed analysis of CTH start-up costs pre-intervention implementation and to describe the relevance of these data for stakeholders to determine implementation feasibility. METHODS: This study is guided by the community perspective, reflecting the investments that a real-world community would need to incur to implement the CTH intervention. We adopted an activity-based costing approach, in which resources related to hiring, training, purchasing, and community dashboard creation were identified through macro- and micro-costing techniques from 34 communities with high rates of fatal opioid overdoses, across four states-Kentucky, Massachusetts, New York, and Ohio. Resources were identified and assigned a unit cost using administrative and semi-structured-interview data. All cost estimates were reported in 2019 dollars. RESULTS: State-level average and median start-up cost (representing 8-10 communities per state) were $268,657 and $175,683, respectively. Hiring and training represented 40%, equipment and infrastructure costs represented 24%, and dashboard creation represented 36% of the total average start-up cost. Comparatively, hiring and training represented 49%, purchasing costs represented 18%, and dashboard creation represented 34% of the total median start-up cost. CONCLUSION: We identified three distinct CTH hiring models that affected start-up costs: hospital-academic (Massachusetts), university-academic (Kentucky and Ohio), and community-leveraged (New York). Hiring, training, and purchasing start-up costs were lowest in New York due to existing local infrastructure. Community-based implementation similar to the New York model may have lower start-up costs due to leveraging of existing infrastructure, relationships, and support from local health departments.

Correction: Ghani et al. Multi-Dimensional Antioxidant Screening of Selected Australian Native Plants and Putative Annotation of Active Compounds. Molecules 2023, 28, 3106.

In the original publication [...].

Estimated Costs and Outcomes Associated With Use and Nonuse of Medications for Opioid Use Disorder During Incarceration and at Release in Massachusetts.

Importance: Most prisons and jails in the US discontinue medications for opioid use disorder (MOUD) upon incarceration and do not initiate MOUD prior to release. Objective: To model the association of MOUD access during incarceration and at release with population-level overdose mortality and OUD-related treatment costs in Massachusetts. Design, Setting, and Participants: This economic evaluation used simulation modeling and cost-effectiveness with costs and quality-adjusted life-years (QALYs) discounted at 3% to compare MOUD treatment strategies in a corrections cohort and an open cohort representing individuals with OUD in Massachusetts. Data were analyzed between July 1, 2021, and September 30, 2022. Exposures: Three strategies were compared: (1) no MOUD provided during incarceration or at release, (2) extended-release (XR) naltrexone offered only at release from incarceration, and (3) all 3 MOUDs (naltrexone, buprenorphine, and methadone) offered at intake. Main Outcomes and Measures: Treatment starts and retention, fatal overdoses, life-years and QALYs, costs, and incremental cost-effectiveness ratios (ICERs). Results: Among 30 000 simulated incarcerated individuals with OUD, offering no MOUD was associated with 40 927 (95% uncertainty interval [UI], 39 001-42 082) MOUD treatment starts over a 5-year period and 1259 (95% UI, 1130-1323) overdose deaths after 5 years. Over 5 years, offering XR-naltrexone at release led to 10 466 (95% UI, 8515-12 201) additional treatment starts, 40 (95% UI, 16-50) fewer overdose deaths, and 0.08 (95% UI, 0.05-0.11) QALYs gained per person, at an incremental cost of $2723 (95% UI, $141-$5244) per person. In comparison, offering all 3 MOUDs at intake led to 11 923 (95% UI, 10 861-12 911) additional treatment starts, compared with offering no MOUD, 83 (95% UI, 72-91) fewer overdose deaths, and 0.12 (95% UI, 0.10-0.17) QALYs per person gained, at an incremental cost of $852 (95% UI, $14-$1703) per person. Thus, XR-naltrexone only was a dominated strategy (both less effective and more costly) and the ICER of all 3 MOUDs compared with no MOUD was $7252 (95% UI, $140-$10 018) per QALY. Among everyone with OUD in Massachusetts, XR-naltrexone only averted 95 overdose deaths over 5 years (95% UI, 85-169)-a 0.9% decrease in state-level overdose mortality-while the all-MOUD strategy averted 192 overdose deaths (95% UI, 156-200)-a 1.8% decrease. Conclusions and Relevance: The findings of this simulation-modeling economic study suggest that offering any MOUD to incarcerated individuals with OUD would prevent overdose deaths and that offering all 3 MOUDs would prevent more deaths and save money compared with an XR-naltrexone-only strategy.

Virtually the Same? Evaluating the Effectiveness of Remote Undergraduate Research Experiences.

In-person undergraduate research experiences (UREs) promote students' integration into careers in life science research. In 2020, the COVID-19 pandemic prompted institutions hosting summer URE programs to offer them remotely, raising questions about whether undergraduates who participate in remote research can experience scientific integration and whether they might perceive doing research less favorably (i.e., not beneficial or too costly). To address these questions, we examined indicators of scientific integration and perceptions of the benefits and costs of doing research among students who participated in remote life science URE programs in Summer 2020. We found that students experienced gains in scientific self-efficacy pre- to post-URE, similar to results reported for in-person UREs. We also found that students experienced gains in scientific identity, graduate and career intentions, and perceptions of the benefits of doing research only if they started their remote UREs at lower levels on these variables. Collectively, students did not change in their perceptions of the costs of doing research despite the challenges of working remotely. Yet students who started with low cost perceptions increased in these perceptions. These findings indicate that remote UREs can support students' self-efficacy development, but may otherwise be limited in their potential to promote scientific integration.

Multi-Dimensional Antioxidant Screening of Selected Australian Native Plants and Putative Annotation of Active Compounds.

Acacia implexa, Eucalyptus rossii and Exocarpos cupressiformis are native plants of Australia, which were used by the First Peoples for medicinal purposes. In this study, 70% aqueous ethanol crude extracts were prepared from A. implexa bark and leaves, E. rossii leaves and E. cupressiformis leaves, and partitioned via sequential extraction with n-hexane, dichloromethane (DCM), ethyl acetate and ethanol. The crude extracts and fractions were screened for antioxidant activity using a novel, high-throughput lipid-based antioxidant assay, as well as the aqueous ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) assay and the Folin-Ciocalteu test for total phenols. In the lipid-based assay, non-polar n-hexane and DCM fractions showed higher antioxidant activity against the formation of peroxides and thiobarbituric acid reactive substances (TBARS) than the other fractions, whereas the non-polar fractions were not effective in aqueous assays. This illustrates that the high potential of the lipid-soluble n-hexane and DCM fractions as antioxidants would have been missed if only aqueous-based assays were used. In addition, the potent antioxidant compounds were putatively annotated using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-qTOF-MS). Gallic acid, (+)-catechin, (-)-epicatechin and tannins were found in most crude extracts.

Budget impact tool for the incorporation of medications for opioid use disorder into jail/prison facilities.

BACKGROUND: Given the personal and public consequences of untreated/undertreated OUD among persons involved in the justice system, an increasing number of jails and prisons are incorporating medication for opioid use disorder (MOUD) into their system. Estimating the costs of implementing and sustaining a particular MOUD program is vital to detention facilities, which typically face modest, fixed health care budgets. We developed a customizable budget impact tool to estimate the implementation and sustainment costs of numerous MOUD delivery models for detention facilities. METHODS: The aim is to describe the tool and present an application of a hypothetical MOUD model. The tool is populated with resources required to implement and sustain various MOUD models in detention facilities. We identified resources via micro-costing techniques alongside randomized clinical trials. The resource-costing method is used to assign values to resources. Resources/costs are categorized as (a) fixed, (b) time-dependent, and (c) variable. Implementation costs include (a), (b), and (c) over a specified timeframe. Sustainment costs include (b) and (c). The MOUD model example entails offering all three FDA-approved medications, with methadone and buprenorphine provided by vendors, and naltrexone by the jail/prison facility. RESULTS: Fixed resources/costs are incurred only once, including accreditation fees and trainings. Time-dependent resources/costs are recurring, but fixed over a given time-period; e.g., medication delivery and staff meetings. Variable resources/costs are those that are a direct function of the number of persons treated, such as the medication provided to each patient. Using nationally representative prices, we estimated fixed/sustainment costs to be $2919/patient, over 1 year. This article estimates annual sustainment costs to be $2885/patient. CONCLUSION: The tool will serve as a valuable asset to jail/prison leadership, policymakers, and other stakeholders interested in identifying/estimating the resources and costs associated with alternative MOUD delivery models, from the planning stages through sustainment.

"How Do We Do This at a Distance?!" A Descriptive Study of Remote Undergraduate Research Programs during COVID-19.

The COVID-19 pandemic shut down undergraduate research programs across the United States. A group of 23 colleges, universities, and research institutes hosted remote undergraduate research programs in the life sciences during Summer 2020. Given the unprecedented offering of remote programs, we carried out a study to describe and evaluate them. Using structured templates, we documented how programs were designed and implemented, including who participated. Through focus groups and surveys, we identified programmatic strengths and shortcomings as well as recommendations for improvements from students' perspectives. Strengths included the quality of mentorship, opportunities for learning and professional development, and a feeling of connection with a larger community. Weaknesses included limited cohort building, challenges with insufficient structure, and issues with technology. Although all programs had one or more activities related to diversity, equity, inclusion, and justice, these topics were largely absent from student reports even though programs coincided with a peak in national consciousness about racial inequities and structural racism. Our results provide evidence for designing remote Research Experiences for Undergraduates (REUs) that are experienced favorably by students. Our results also indicate that remote REUs are sufficiently positive to further investigate their affordances and constraints, including the potential to scale up offerings, with minimal concern about disenfranchising students.

Engaging Undergraduates in Research Experiences at a Distance: Insights and Recommendations for Remote URE.

Undergraduates phenotyping Arabidopsis knockouts (unPAK) is a biology research network that has provided undergraduate research experiences (URE) since 2010. In 2019, unPAK expanded to include a summer URE that engaged undergraduate researchers from across the network in an intensive collaborative program. In response to the COVID-19 pandemic in 2020, unPAK rapidly shifted to provide the summer URE program remotely. This article describes (i) the instructional and communication processes of unPAK in the remote URE; and (ii) a summative assessment of the outcomes associated with the remote summer program as compared with the 2019 in-person program. We conclude by offering timely recommendations for educators in biology that emerged from the 2020 remote summer research experience, which may be applicable to other remote UREs and course-based research experiences (CUREs).

Health economic analyses of the justice community opioid innovation network (JCOIN).

The Justice Community Opioid Innovation Network (JCOIN) will generate real-world evidence to address the unique needs of people with opioid use disorder (OUD) in justice settings. Evidence regarding the economic value of OUD interventions in justice populations is limited. Moreover, the variation in economic study designs is a barrier to defining specific interventions as broadly cost-effective. The JCOIN Health Economics Analytic Team (HEAT) has worked closely with the Measures Committee to incorporate common economic measures and instruments across JCOIN studies, which will: a) ensure rigorous economic evaluations within each trial; b) enhance comparability of findings across studies; and c) allow for cross-study analyses of trials with similar designs/settings (e.g., pre-reentry MOUD), to assess questions beyond the scope of a single study, while controlling for and evaluating the effect of intervention-, organizational-, and population-level characteristics. We describe shared trial characteristics relevant to the economic evaluations, and discuss potential cross-study economic analyses.

A clinical protocol of a comparative effectiveness trial of extended-release naltrexone versus extended-release buprenorphine with individuals leaving jail.

This study is a randomized, open label, controlled trial of extended-release buprenorphine (XR-B; BRIXADI™ formulation) versus extended-release naltrexone (XR-NTX) in Maryland jails. A 7-site, open-label, equivalence design will randomly assign 240 adults with a history of opioid use disorder (OUD), stratified by gender and jail, who are nearing release to one of two treatment arms: 1) XR-B in jail or 2) XR-NTX in jail, both followed by 6 monthly injections postrelease at a community treatment program. The primary aim is to determine the rate of pharmacotherapy adherence (number of monthly injections received) of XR-B compared to XR-NTX. The proposed study is innovative because it will be the first randomized clinical trial in the U.S. assessing the effectiveness of receiving XR-B vs. XR-NTX in county jails. The public health impact of the study will be highly significant and far-reaching because most individuals with OUD do not receive treatment while incarcerated, thereby substantially raising their likelihood of relapse to drug use, overdose death, and re-incarceration. Understanding how to expand acceptance of medications for OUD in jails, particularly extended-release medications, and supporting treatment engagement and medication adherence in transition to the community, has far-reaching implications for improving treatment access and success in this population.

Advancing Science while Training Undergraduates: Recommendations from a Collaborative Biology Research Network.

Biology research is becoming increasingly dependent on large-scale, "big data," networked research initiatives. At the same time, there has been a corresponding effort to expand undergraduate participation in research to benefit student learning and persistence in science. This essay examines the confluence of this trend through eight years of a collaboration within a successful biology research network that explicitly incorporates undergraduates into large-scale scientific research. We draw upon interviews with faculty in this network to consider the interplay of scientific and pedagogical objectives at the heart of this undergraduate-focused network research project. We identify ways that this network has expanded and diversified access to scientific knowledge production for faculty and students and examine a goal conflict that emerged around the dual objectives of mentoring emerging scientists while producing high-quality scientific data for the larger biology community. Based on lessons learned within this network, we provide three recommendations that can support institutions and faculty engaging in networked research projects with undergraduates: (1) establish rigorous protocols to ensure data and database quality, (2) protect personnel time to coordinate network and scientific processes, and (3) select appropriate partners and establish explicit expectations for specific collaborations.

A Novel Mechanism for Activation of Myosin Regulatory Light Chain by Protein Kinase C-Delta in Drosophila.

Myosin is an essential motor protein, which in muscle is comprised of two molecules each of myosin heavy-chain (MHC), the essential or alkali myosin light-chain 1 (MLC1), and the regulatory myosin light-chain 2 (MLC2). It has been shown previously that MLC2 phosphorylation at two canonical serine residues is essential for proper flight muscle function in Drosophila; however, MLC2 is also phosphorylated at additional residues for which the mechanism and functional significance is not known. We found that a hypomorphic allele of Pkcδ causes a flightless phenotype; therefore, we hypothesized that PKCδ phosphorylates MLC2. We rescued flight disability by duplication of the wild-type Pkcδ gene. Moreover, MLC2 is hypophosphorylated in Pkcδ mutant flies, but it is phosphorylated in rescued animals. Myosin isolated from Pkcδ mutant flies shows a reduced actin-activated ATPase activity, and MLC2 in these myosin preparations can be phosphorylated directly by recombinant human PKCδ. The flightless phenotype is characterized by a shortened and disorganized sarcomere phenotype that becomes apparent following eclosion. We conclude that MLC2 is a direct target of phosphorylation by PKCδ, and that this modification is necessary for flight muscle maturation and function.

Health-related quality of life and opioid use disorder pharmacotherapy: A secondary analysis of a clinical trial.

OBJECTIVE: To examine the health-related quality-of-life (HRQoL) of persons with opioid use disorder (OUD) seeking treatment in an inpatient detoxification or short-term residential setting; continuing treatment as outpatients. METHODS: We conducted a secondary analysis of data from a clinical trial (N = 508) where participants were randomized to extended-release naltrexone or buprenorphine-naloxone for the prevention of opioid relapse. We used a generalized structural equation regression mixture model to identify associations of HRQoL (EQ-5D) trajectories, including latent characteristics, over the 24-week trial and 36-week follow-up period, among participants who reported HRQoL beyond baseline. This novel framework accounted for baseline and time-varying characteristics, while simultaneously identifying latent classes. RESULTS: We identified two subpopulations: HRQoL "pharmacotherapy responsive" (82.3 %) and HRQoL "characteristic sensitive" (17.7 %). The pharmacotherapy responsive subpopulation was characterized by a shortterm HRQoL improvement and then stable HRQoL over time, and by a positive association between HRQoL and receiving pharmacotherapy in the past 30 days. The characteristic sensitive subpopulation was characterized by an initial improvement in HRQoL with a gradual decline over time, and no significant HRQoL response to pharmacotherapy. HRQoL changes over time in this subpopulation were more influenced by baseline demographic, socioeconomic, and psychosocial characteristics. CONCLUSION: Our findings suggest that while HRQoL may be improved and sustained through targeted efforts to promote use of pharmacotherapy for many persons with OUD, an identifiable subpopulation may require additional services that address socioeconomic and psychosocial issues to achieve HRQoL benefits. Our analysis provides insight for improving individualized care for persons with opioid use disorder seeking treatment.

Economic evaluation in the National Drug Abuse Treatment Clinical Trials Network: Past, present, and future.

Economic evaluations provide evidence that informs stakeholders on how to efficiently allocate real and financial healthcare resources. The purpose of this study was to review and discuss the integration of economic evaluations into the National Drug Abuse Treatment Clinical Trials Network (CTN) since its inception, as well as expectations for the future of this relationship. A systematic review was performed on published and planned CTN economic evaluations in the CTN dissemination library and PubMed. The well-established Drummond checklist was used to evaluate the comprehensiveness and methodological rigor of published articles. One hundred thirty-eight ancillary, follow-up, or original protocols were reviewed, and 78 potentially relevant published articles were identified. A total number of 14 protocols included an economic evaluation. Of these, 6 protocols were completed, 2 were reported as active, and 6 were reported as in-development at the time of this review. Of the 78 published articles, 9 met the inclusion criteria. As gauged by the Drummond checklist, the quality of CTN published economic evaluations were found to improve over time, and recent published articles were identified as guides to cutting-edge economic research. As the CTN continues to grow and mature, it is imperative that high-quality economic evaluations are incorporated alongside trials in order to maximize the public health impact of the CTN.

Bulk and compound-specific stable isotope ratio analysis for authenticity testing of organically grown tomatoes.

Until now, there has been a lack of analytical methods that can reliably verify the authenticity of organically grown plants and derived organic food products. In this study, stable isotope ratio analysis of hydrogen (H, δ2H), carbon (C, δ13C), nitrogen (N, δ15N), oxygen (O, δ18O) and sulfur (S, δ34S) was conducted along the tomato passata production process using organic and conventionally grown tomatoes from two Italian regions over two years. A gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) based method was developed and applied for analysis of C and N isotope ratios in amino acids derived from tomatoes. Of the bulk isotope ratios, δ15N was the most significant parameter for discriminating organic from conventional products. The classification power was improved significantly by compound-specific isotope analysis regardless of the production years and regions. We conclude that isotope analysis of amino acids is a novel analytical tool for complementing existing certification and control procedures in the organic tomato sector.

Postgraduate clinical physiotherapy education in acute hospitals: a cohort study.

Background: Junior physiotherapists require satisfactory clinical skills to work effectively within the acute hospital setting for service quality and consistency. Objective: To investigate the effects of stream-specific clinical training on junior physiotherapist self-efficacy, self-rated confidence, and self-rated ability to work independently during weekend shifts. Design: Prospective cohort study. Participants: Eighteen junior physiotherapists. Methods: Physiotherapists undertook 8 h of stream-specific education in: pediatrics, women's health, neuro-medical, musculoskeletal, cardiorespiratory, and critical care over 8 weeks. Learning objectives were evaluated using a self-efficacy (0-100) scale and self-rated confidence was measured with a 4-point Likert scale (not confident to independent). Self-rated ability to independently work weekend shifts was measured dichotomously (yes/no). Results: Participants completed an average of three stream-specific programs in the study period. Post-training, mean improvement in self-efficacy across objectives ranged from 2.9 (95% CI -8.7 to 14.5) to 43.3 (95% CI 4.8-81.8) points, p < 0.05 for 80% of objectives. Self-rated confidence scores improved for 45.6% of stream-specific learning objectives; 52.8% were unchanged and 1.7% reported a decrease in confidence. Self-rated ability to work stream-specific weekend shifts increased from 56-70%, but no stream achieved a significant increase in staff able to independently work weekend shifts (p range 0.10 to 1.0). Conclusions: A stream-specific education program increased junior physiotherapists' self-efficacy and self-rated confidence but not perceived ability to work independently on weekends. Results were non-randomized and actual practice change was not assessed. Future studies could investigate different educational structures in a blinded, randomized manner on clinical practice change.

The Dangerous Middle: Situational Awareness and Worker Perception of Beetle Kill.

Forest workers, including loggers, foresters, and wildland firefighters, are regularly exposed to some of the most fatal occupational environments in the United States. These hazardous work environments may become even more complex and dynamic when subject to bark beetle outbreaks that have resulted in significant tree mortality. The impacts of tree death from bark beetles are significant, with the cumulative 17-year (2000-2016) footprint for bark beetle caused tree mortality estimated at 54 million acres. However, how workers think about and act in these environments is understudied. This study, therefore, approaches the issue of beetle kill and forest worker safety by examining the perspectives or workers themselves. Its contribution is to leverage ethnographic research to provide insights that can generate new research questions, better inform outreach, and ultimately improve worker safety outcomes. The resulting insights show that beetle kill was understood by workers as a hazard that increased the complexity and dynamism of the work environment, making situational awareness both more necessary and more difficult to maintain. While much research about situational awareness focuses on hazardous situations, it is suggested that building adequate situational awareness should also include broader considerations of organizational communication, as well as training and experience considered over the course of entire careers.

Becoming a "Science Person": Faculty Recognition and the Development of Cultural Capital in the Context of Undergraduate Biology Research.

We argue that cultural capital plays an underexamined role in students' recognition as budding scientists by faculty. By triangulating interview data from undergraduates and faculty mentors in a multi-institutional biology research network, we identified a set of intersecting domains of capital that help render students recognizable to faculty. We argue that faculty recognition often reflects a (mis)alignment between the cultural capital that students possess and display and what faculty expect to see. To understand why mis- or underrecognition occurs, and how this influenced students' opportunities to further develop cultural capital, we explored our data set for patterns of explanation. Several key themes cut across students' experiences and influenced their recognition by faculty: Faculty more easily recognized students interested in research science trajectories and those involved in institutional programs to support science, technology, engineering, and mathematics success. Students with competing family responsibilities struggled to maintain faculty recognition. Finally, faculty who broadened their scopes of recognition were able to affirm the science identities of students with fewer incoming cultural resources in science and support their development of capital. Students can and do develop scientific cultural capital through practice, but this requires access to research and mentorship that explicitly teaches students the implicit "rules of the game."

Differentiation of wood-derived vanillin from synthetic vanillin in distillates using gas chromatography/combustion/isotope ratio mass spectrometry for δ13 C analysis.

RATIONALE: Typical storage in oak barrels releases in distillates different degradation products such as vanillin, which play an important role in flavour and aroma. The addition of vanillin, as well as other aroma compounds, of different origin is prohibited by European laws. As vanillin samples from different sources have different δ13 C values, the δ13 C value could be used to determine whether the vanillin is authentic (lignin-derived), or if it has been added from another source (e.g. synthetic). METHODS: The δ13 C values for vanillin derived from different sources, including natural, synthetic and tannins, were measured by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS), after diethyl ether addition and/or ethanol dilution. A method for analysing vanillin in distillates after dichloromethane extraction was developed. Tests were undertaken to prove the reliability, reproducibility and accuracy of the method with standards and samples. Distillate samples were run to measure the δ13 C values of vanillin and to compare them with values for other sources of vanillin. RESULTS: δ13 C values were determined for: natural vanillin extracts (-21.0 to -19.3‰, 16 samples); vanillin ex-lignin (-28.2‰, 1 sample); and synthetic vanillin (-32.6 to -29.3‰, 7 samples). Seventeen tannin samples were found to have δ13 C values of -29.5 to -26.7‰, which were significantly different (p < 0.05) from those of the natural and synthetic vanillins. The vanillin δ13 C values measured in distillates (-28.9 to -25.7‰) were mainly in the tannin range, although one spirit (-32.5‰) was found to contain synthetic vanillin. CONCLUSIONS: The results show that synthetic vanillin added to a distillate could be differentiated from vanillin derived from oak barrels by their respective δ13 C values. The GC/C/IRMS method could be a useful tool in the determination of adulteration of distillates.

Dietary Effects on Stable Carbon Isotope Composition of Fatty Acids in Polar and Neutral Fractions of Intramuscular Fat of Lambs.

In this study we measured δ13C values of the main fatty acids (FA) present in neutral and polar intramuscular lipids of meat samples from 24 lambs, fed with four different diets supplemented with sunflower and linseed oil and the tanniferous shrub Cistus ladanifer L. The objective was to understand if the increase in intramuscular fat observed in lambs fed simultaneously C. ladanifer and oil was explained mostly by incorporation of diet derived FA or by increased de novo FA synthesis. De novo FA synthesis was evaluated by 13C enrichment (‰) of 16:0 in intramuscular lipids compared to bulk diet or compared to dietary 16:0. Oil reduced 13C enrichment of 16:0 in muscle lipid but had no effect when the diet included C. ladanifer (P value <0.01). Thus, dietary C. ladanifer blocked the inhibitory effects of lipid supplementation on de novo FA synthesis.