Loosenin-Like Proteins from Phanerochaete carnosa Impact Both Cellulose and Chitin Fiber Networks.

Microbial expansin-related proteins are ubiquitous across bacterial and fungal organisms and reportedly play a role in the modification and deconstruction of cell wall polysaccharides, including lignocellulose. So far, very few microbial expansin-related proteins, including loosenins and loosenin-like (LOOL) proteins, have been functionally characterized. Herein, four LOOLs encoded by Phanerochaete carnosa and belonging to different subfamilies (i.e., PcaLOOL7 and PcaLOOL9 from subfamily A and PcaLOOL2 and PcaLOOL12 from subfamily B) were recombinantly produced and the purified proteins were characterized using diverse cellulose and chitin substrates. The purified PcaLOOLs weakened cellulose filter paper and cellulose nanofibril networks (CNF); however, none significantly boosted cellulase activity on the selected cellulose substrates (Avicel and Whatman paper). Although fusing the family 63 carbohydrate-binding module (CBM63) of BsEXLX1 encoded by Bacillus subtilis to PcaLOOLs increased their binding to cellulose, the CBM63 fusion appeared to reduce the cellulose filter paper weakening observed using wild-type proteins. Binding of PcaLOOLs to alpha-chitin was considerably higher than that to cellulose (Avicel) and was pH dependent, with the highest binding at pH 5.0. Amendment of certain PcaLOOLs in fungal liquid cultivations also impacted the density of the cultivated mycelia. The present study reveals the potential of fungal expansin-related proteins to impact both cellulose and chitin networks and points to a possible biological role in fungal cell wall processing. IMPORTANCE The present study deepens investigations of microbial expansin-related proteins and their applied significance by (i) reporting a detailed comparison of diverse loosenins encoded by the same organism, (ii) considering both cellulosic and chitin-containing materials as targeted substrates, and (iii) investigating the impact of the C-terminal carbohydrate binding module (CBM) present in other expansin-related proteins on loosenin function. By revealing the potential of fungal loosenins to impact both cellulose and chitin-containing networks, our study reveals a possible biological and applied role of loosenins in fungal cell wall processing.

Current Review of the Function and Regulation of Tuberoinfundibular Dopamine Neurons.

Tuberoinfundibular dopamine (TIDA) neurons have cell bodies located in the arcuate nucleus of the mediobasal hypothalamus. They project to the external zone of the median eminence, and the dopamine (DA) released there is carried by the hypophysial portal vasculature to the anterior pituitary. The DA then activates D2 receptors to inhibit prolactin (PRL) secretion from lactotrophs. The TIDA neuronal population is the principal regulatory factor controlling PRL secretion. The neuroendocrine role subserved by TIDA neurons sets them apart from other dopaminergic populations like the nigrostriatal and mesolimbic DA neurons. TIDA neurons exhibit intrinsic oscillatory fluctuations in their membrane potential that give rise to phasic firing and bursting activity. TIDA neuronal activity is sexually differentiated and modulated by gonadal hormones and PRL, as well as an array of small molecule and peptide neurotransmitters. This review covers these characteristics.

The vital role of arcuate nociceptin/orphanin FQ neurones in mounting an oestradiol-dependent adaptive response to negative energy balance via inhibition of nearby proopiomelanocortin neurones.

We tested the hypothesis that N/OFQ neurones in the arcuate nucleus (N/OFQARC ) inhibit proopiomelanocortin (POMCARC ) neurones in a diet- and hormone-dependent manner to promote a more extensive rebound hyperphagia upon re-feeding following an 18 h fast. We utilized intact male or ovariectomized (OVX) female mice subjected to ad libitum-feeding or fasting conditions. N/OFQARC neurones under negative energy balance conditions displayed heightened sensitivity as evidenced by a decreased rheobase threshold, increased firing frequency, and increased burst duration and frequency compared to ad libitum-feeding conditions. Stimulation of N/OFQARC neurones more robustly inhibited POMCARC neurones under fasting conditions compared to ad libitum-feeding conditions. N/OFQARC inhibition of POMCARC neurones is hormone dependent as chemostimulation of N/OFQARC neurones from fasted males and OVX females produced a sizable outward current in POMCARC neurones. Oestradiol (E2 ) markedly attenuated the N/OFQ-induced POMCARC outward current. Additionally, N/OFQ tonically inhibits POMCARC neurones to a greater degree under fasting conditions than in ad libitum-feeding conditions as evidenced by the abrogation of N/OFQ-nociceptin opioid peptide (NOP) receptor signalling and inhibition of N/OFQ release via chemoinhibition of N/OFQARC neurones. Intra-arcuate nucleus application of N/OFQ further elevated the hyperphagic response and increased meal size during the 6 h re-feed period, and these effects were mimicked by chemostimulation of N/OFQARC neurones in vivo. E2 attenuated the robust N/OFQ-induced rebound hyperphagia seen in vehicle-treated OVX females. These data demonstrate that N/OFQARC neurones play a vital role in mitigating the impact of negative energy balance by inhibiting the excitability of anorexigenic neural substrates, an effect that is diminished by E2 in females. KEY POINTS: Nociceptin/orphanin FQ (N/OFQ) promotes increased energy intake and decreased energy expenditure under conditions of positive energy balance in a sex- and hormone-dependent manner. Here it is shown that under conditions of negative energy balance, i.e. fasting, N/OFQ inhibits anorexigenic proopiomelanocortin (POMC) neurones to a greater degree compared to homeostatic conditions due to fasting-induced hyperexcitability of N/OFQ neurones. Additionally, N/OFQ promotes a sustained increase in rebound hyperphagia and increase in meal size during the re-feed period following a fast. These results promote greater understanding of how energy balance influences the anorexigenic circuitry of the hypothalamus, and aid in understanding the neurophysiological pathways implicated in eating disorders promoting cachexia.

Conservation of endo-glucanase 16 (EG16) activity across highly divergent plant lineages.

Plant cell walls are highly dynamic structures that are composed predominately of polysaccharides. As such, endogenous carbohydrate active enzymes (CAZymes) are central to the synthesis and subsequent modification of plant cells during morphogenesis. The endo-glucanase 16 (EG16) members constitute a distinct group of plant CAZymes, angiosperm orthologs of which were recently shown to have dual ß-glucan/xyloglucan hydrolase activity. Molecular phylogeny indicates that EG16 members comprise a sister clade with a deep evolutionary relationship to the widely studied apoplastic xyloglucan endo-transglycosylases/hydrolases (XTH). A cross-genome survey indicated that EG16 members occur as a single ortholog across species and are widespread in early diverging plants, including the non-vascular bryophytes, for which functional data were previously lacking. Remarkably, enzymological characterization of an EG16 ortholog from the model moss Physcomitrella patens (PpEG16) revealed that EG16 activity and sequence/structure are highly conserved across 500 million years of plant evolution, vis-à-vis orthologs from grapevine and poplar. Ex vivo biomechanical assays demonstrated that the application of EG16 gene products caused abrupt breakage of etiolated hypocotyls rather than slow extension, thereby indicating a mode-of-action distinct from endogenous expansins and microbial endo-glucanases. The biochemical data presented here will inform future genomic, genetic, and physiological studies of EG16 enzymes.

Pituitary Adenylate Cyclase-Activating Polypeptide Excites Proopiomelanocortin Neurons: Implications for the Regulation of Energy Homeostasis.

OBJECTIVE: We examined whether pituitary adenylate cyclase-activating polypeptide (PACAP) excites proopiomelanocortin (POMC) neurons via PAC1 receptor mediation and transient receptor potential cation (TRPC) channel activation. METHODS: Electrophysiological recordings were done in slices from both intact male and ovariectomized (OVX) female PACAP-Cre mice and eGFP-POMC mice. RESULTS: In recordings from POMC neurons in eGFP-POMC mice, PACAP induced a robust inward current and increase in conductance in voltage clamp, and a depolarization and increase in firing in current clamp. These postsynaptic actions were abolished by inhibitors of the PAC1 receptor, TRPC channels, phospholipase C, phosphatidylinositol-3-kinase, and protein kinase C. Estradiol augmented the PACAP-induced inward current, depolarization, and increased firing, which was abrogated by estrogen receptor (ER) antagonists. In optogenetic recordings from POMC neurons in PACAP-Cre mice, high-frequency photostimulation induced inward currents, depolarizations, and increased firing that were significantly enhanced by Gq-coupled membrane ER signaling in an ER antagonist-sensitive manner. Importantly, the PACAP-induced excitation of POMC neurons was notably reduced in obese, high-fat (HFD)-fed males. In vivo experiments revealed that intra-arcuate nucleus (ARC) PACAP as well as chemogenetic and optogenetic stimulation of ventromedial nucleus (VMN) PACAP neurons produced a significant decrease in energy intake accompanied by an increase in energy expenditure, effects blunted by HFD in males and partially potentiated by estradiol in OVX females. CONCLUSIONS: These findings reveal that the PACAP-induced activation of PAC1 receptor and TRPC5 channels at VMN PACAP/ARC POMC synapses is potentiated by estradiol and attenuated under conditions of diet-induced obesity/insulin resistance. As such, they advance our understanding of how PACAP regulates the homeostatic energy balance circuitry under normal and pathophysiological circumstances.

Adaptive Changes in the Central Control of Energy Homeostasis Occur in Response to Variations in Energy Status.

Energy homeostasis is regulated in coordinate fashion by the brain-gut axis, the homeostatic energy balance circuitry in the hypothalamus and the hedonic energy balance circuitry comprising the mesolimbcortical A10 dopamine pathway. Collectively, these systems convey and integrate information regarding nutrient status and the rewarding properties of ingested food, and formulate it into a behavioral response that attempts to balance fluctuations in consumption and food-seeking behavior. In this review we start with a functional overview of the homeostatic and hedonic energy balance circuitries; identifying the salient neural, hormonal and humoral components involved. We then delve into how the function of these circuits differs in males and females. Finally, we turn our attention to the ever-emerging roles of nociceptin/orphanin FQ (N/OFQ) and pituitary adenylate cyclase-activating polypeptide (PACAP)-two neuropeptides that have garnered increased recognition for their regulatory impact in energy homeostasis-to further probe how the imposed regulation of energy balance circuitry by these peptides is affected by sex and altered under positive (e.g., obesity) and negative (e.g., fasting) energy balance states. It is hoped that this work will impart a newfound appreciation for the intricate regulatory processes that govern energy homeostasis, as well as how recent insights into the N/OFQ and PACAP systems can be leveraged in the treatment of conditions ranging from obesity to anorexia.

Leading Innovative Practice: Leadership Attributes in LEAP Practices.

Policy Points An onslaught of policies from the federal government, states, the insurance industry, and professional organizations continually requires primary care practices to make substantial changes; however, ineffective leadership at the practice level can impede the dissemination and scale-up of these policies. The inability of primary care practice leadership to respond to ongoing policy demands has resulted in moral distress and clinician burnout. Investments are needed to develop interventions and educational opportunities that target a broad array of leadership attributes. CONTEXT: Over the past several decades, health care in the United States has undergone substantial and rapid change. At the heart of this change is an assumption that a more robust primary care infrastructure helps achieve the quadruple aim of improved care, better patient experience, reduced cost, and improved work life of health care providers. Practice-level leadership is essential to succeed in this rapidly changing environment. Complex adaptive systems theory offers a lens for understanding important leadership attributes. METHODS: A review of the literature on leadership from a complex adaptive system perspective identified nine leadership attributes hypothesized to support practice change: motivating others to engage in change, managing abuse of power and social influence, assuring psychological safety, enhancing communication and information sharing, generating a learning organization, instilling a collective mind, cultivating teamwork, fostering emergent leaders, and encouraging boundary spanning. Through a secondary qualitative analysis, we applied these attributes to nine practices ranking high on both a practice learning and leadership scale from the Learning from Effective Ambulatory Practice (LEAP) project to see if and how these attributes manifest in high-performing innovative practices. FINDINGS: We found all nine attributes identified from the literature were evident and seemed important during a time of change and innovation. We identified two additional attributes-anticipating the future and developing formal processes-that we found to be important. Complexity science suggests a hypothesized developmental model in which some attributes are foundational and necessary for the emergence of others. CONCLUSIONS: Successful primary care practices exhibit a diversity of strong local leadership attributes. To meet the realities of a rapidly changing health care environment, training of current and future primary care leaders needs to be more comprehensive and move beyond motivating others and developing effective teams.

Xyloglucan in the primary cell wall: assessment by FESEM, selective enzyme digestions and nanogold affinity tags.

Xyloglucan has been hypothesized to bind extensively to cellulose microfibril surfaces and to tether microfibrils into a load-bearing network, thereby playing a central role in wall mechanics and growth, but this view is challenged by newer results. Here we combined high-resolution imaging by field emission scanning electron microscopy (FESEM) with nanogold affinity tags and selective endoglucanase treatments to assess the spatial location and conformation of xyloglucan in onion cell walls. FESEM imaging of xyloglucanase-digested cell walls revealed an altered microfibril organization but did not yield clear evidence of xyloglucan conformations. Backscattered electron detection provided excellent detection of nanogold affinity tags in the context of wall fibrillar organization. Labelling with xyloglucan-specific CBM76 conjugated with nanogold showed that xyloglucans were associated with fibril surfaces in both extended and coiled conformations, but tethered configurations were not observed. Labelling with nanogold-conjugated CBM3, which binds the hydrophobic surface of crystalline cellulose, was infrequent until the wall was predigested with xyloglucanase, whereupon microfibril labelling was extensive. When tamarind xyloglucan was allowed to bind to xyloglucan-depleted onion walls, CBM76 labelling gave positive evidence for xyloglucans in both extended and coiled conformations, yet xyloglucan chains were not directly visible by FESEM. These results indicate that an appreciable, but still small, surface of cellulose microfibrils in the onion wall is tightly bound with extended xyloglucan chains and that some of the xyloglucan has a coiled conformation.

Workforce Configurations to Provide High-Quality, Comprehensive Primary Care: a Mixed-Method Exploration of Staffing for Four Types of Primary Care Practices.

BACKGROUND: Broad consensus exists about the value and principles of primary care; however, little is known about the workforce configurations required to deliver it. OBJECTIVE: The aim of this study was to explore the team configurations and associated costs required to deliver high-quality, comprehensive primary care. METHODS: We used a mixed-method and consensus-building process to develop staffing models based on data from 73 exemplary practices, findings from 8 site visits, and input from an expert panel. We first defined high-quality, comprehensive primary care and explicated the specific functions needed to deliver it. We translated the functions into full-time-equivalent staffing requirements for a practice serving a panel of 10,000 adults and then revised the models to reflect the divergent needs of practices serving older adults, patients with higher social needs, and a rural community. Finally, we estimated the labor and overhead costs associated with each model. RESULTS: A primary care practice needs a mix of 37 team members, including 8 primary care providers (PCPs), at a cost of $45 per patient per month (PPPM), to provide comprehensive primary care to a panel of 10,000 actively managed adults. A practice requires a team of 52 staff (including 12 PCPs) at $64 PPPM to care for a panel of 10,000 adults with a high proportion of older patients, and 50 staff (with 10 PCPs) at $56 PPPM for a panel of 10,000 with high social needs. In rural areas, a practice needs 22 team members (with 4 PCPs) at $46 PPPM to serve a panel of 5000 adults. CONCLUSIONS: Our estimates provide health care decision-makers with needed guideposts for considering primary care staffing and financing and inform broader discussions on primary care innovations and the necessary resources to provide high-quality, comprehensive primary care in the USA.

Self-management: Enabling and empowering patients living with cancer as a chronic illness.

With recent improvements in the early detection, diagnosis, and treatment of cancer, people with cancer are living longer, and their cancer may be managed as a chronic illness. Cancer as a chronic illness places new demands on patients and families to manage their own care, and it challenges old paradigms that oncology's work is done after treatment. As a chronic illness, however, cancer care occurs on a continuum that stretches from prevention to the end of life, with early detection, diagnosis, treatment, and survivorship in between. In this article, self-management interventions that enable patients and families to participate in managing their care along this continuum are reviewed. Randomized controlled trials of self-management interventions with cancer patients and families in the treatment, survivorship, and end-of-life phases of the cancer care continuum are reviewed, and the Chronic Care Model is presented as a model of care that oncology practices can use to enable and empower patients and families to engage in self-management. It is concluded that the need for a common language with which to speak about self-management and a common set of self-management actions for cancer care notwithstanding, oncology practices can now build strong relationships with their patients and formulate mutually agreed upon care plans that enable and empower patients to care for themselves in the way they prefer.

Roles and Functions of Community Health Workers in Primary Care.

Community health workers have potential to enhance primary care access and quality, but remain underutilized. To provide guidance on their integration, we characterized roles and functions of community health workers in primary care through a literature review and synthesis. Analysis of 30 studies identified 12 functions (ie, care coordination, health coaching, social support, health assessment, resource linking, case management, medication management, remote care, follow-up, administration, health education, and literacy support) and 3 prominent roles representing clusters of functions: clinical services, community resource connections, and health education and coaching. We discuss implications for community health worker training and clinical support in primary care.

Sex differences in cannabinoid-regulated biology: A focus on energy homeostasis.

Considerable strides have been made over the past 20 years in our understanding of the ligands, receptor subtypes, signal transduction mechanisms and biological actions comprising the endocannabinoid system. From the ever-expanding number of studies that have been conducted during this time, it has become increasingly clear that sex differences are the cornerstone of cannabinoid-regulated biology. Available evidence has demonstrated that these sex differences endure in the absence of gonadal steroids, and are modulated by the acute, activational effects of these hormones. This review focuses on select aspects of sexually differentiated, cannabinoid-regulated biology, with a particular emphasis on the control of energy balance. It is anticipated that it will lend impactful insight into the pervasive and diverse disparities in how males and females respond to cannabinoids--from the organismal level down to the molecular level. Additionally, it will furnish a newfound appreciation for the need to recalibrate our thinking in terms of how cannabinoids are used as therapeutic adjuvants for a broad range of clinical disorders and associated comorbidities, including body wasting and obesity.

Understanding What Is Most Important to Individuals with Multiple Chronic Conditions: A Qualitative Study of Patients' Perspectives.

BACKGROUND: To improve care for individuals living with multiple chronic conditions, patients and providers must align care planning with what is most important to patients in their daily lives. We have a limited understanding of how to effectively encourage communication about patients' personal values during clinical care. OBJECTIVE: To identify what patients with multiple chronic conditions describe as most important to their well-being and health. DESIGN: We interviewed individuals with multiple chronic conditions in their homes and analyzed results qualitatively, guided by grounded theory. PARTICIPANTS: A total of 31 patients (mean age 68.7 years) participated in the study, 19 of which included the participation of family members. Participants were from Kaiser Permanente Washington, an integrated health care system in Washington state. APPROACH: Qualitative analysis of home visits, which consisted of semi-structured interviews aided by photo elicitation. KEY RESULTS: Analysis revealed six domains of what patients described as most important for their well-being and health: principles, relationships, emotions, activities, abilities, and possessions. Personal values were interrelated and rarely expressed as individual values in isolation. CONCLUSIONS: The domains describe the range and types of personal values multimorbid older adults deem important to well-being and health. Understanding patients' personal values across these domains may be useful for providers when developing, sharing, and following up on care plans.

Testosterone Rapidly Augments Retrograde Endocannabinoid Signaling in Proopiomelanocortin Neurons to Suppress Glutamatergic Input from Steroidogenic Factor 1 Neurons via Upregulation of Diacylglycerol Lipase-α.

Testosterone exerts profound effects on reproduction and energy homeostasis. Like other orexigenic hormones, it increases endocannabinoid tone within the hypothalamic feeding circuitry. Therefore, we tested the hypothesis that testosterone upregulates the expression of diacylglycerol lipase (DAGL)α in the hypothalamic arcuate nucleus (ARC) to increase energy intake via enhanced endocannabinoid-mediated retrograde inhibition of anorexigenic proopiomelanocortin (POMC) neurons. Energy intake, meal patterns, and energy expenditure were evaluated in orchidectomized, male guinea pigs treated subcutaneously with testosterone propionate (TP; 400 µg) or its sesame oil vehicle (0.1 mL). TP rapidly increased energy intake, meal size, O2 consumption, CO2 production, and metabolic heat production, all of which were antagonized by prior administration of the DAGL inhibitor orlistat (3 µg) into the third ventricle. These orlistat-sensitive, TP-induced increases in energy intake and expenditure were temporally associated with a significant elevation in ARC DAGLα expression. Electrophysiological recordings in hypothalamic slices revealed that TP potentiated depolarization-induced suppression of excitatory glutamatergic input onto identified ARC POMC neurons, which was also abolished by orlistat (3 µM), the CB1 receptor antagonist AM251 (1 µM), and the AMP-activated protein kinase inhibitor compound C (30 µM) and simulated by transient bath application of the dihydrotestosterone mimetic Cl-4AS-1 (100 nM) and testosterone-conjugated bovine serum albumin (100 nM). Thus, testosterone boosts DAGLα expression to augment retrograde, presynaptic inhibition of glutamate release onto ARC POMC neurons that, in turn, increases energy intake and expenditure. These studies advance our understanding of how androgens work within the hypothalamic feeding circuitry to affect changes in energy balance.

Effective team-based primary care: observations from innovative practices.

BACKGROUND: Team-based care is now recognized as an essential feature of high quality primary care, but there is limited empiric evidence to guide practice transformation. The purpose of this paper is to describe advances in the configuration and deployment of practice teams based on in-depth study of 30 primary care practices viewed as innovators in team-based care. METHODS: As part of LEAP, a national program of the Robert Wood Johnson Foundation, primary care experts nominated 227 innovative primary care practices. We selected 30 practices for intensive study through review of practice descriptive and performance data. Each practice hosted a 3-day site visit between August, 2012 and September, 2013, where specific advances in team configuration and roles were noted. Advances were identified by site visitors and confirmed at a meeting involving representatives from each of the 30 practices. RESULTS: LEAP practices have expanded the roles of existing staff and added new personnel to provide the person power and skills needed to perform the tasks and functions expected of a patient-centered medical home (PCMH). LEAP practice teams generally include a rich array of staff, especially registered nurses (RNs), behavioral health specialists, and lay health workers. Most LEAP practices organize their staff into core teams, which are built around partnerships between providers and specific Medical Assistants (MAs), and often include registered nurses (RNs) and others such as health coaches or receptionists. MAs, RNs, and other staff are heavily involved in the planning and delivery of preventive and chronic illness care. The care of more complex patients is supported by behavioral health specialists, RN care managers, and pharmacists. Standing orders and protocols enable staff to act independently. CONCLUSIONS: The 30 LEAP practices engage health professional and lay staff in patient care to the maximum extent, which enables the practices to meet the expectations of a PCMH and helps free up providers to focus on tasks that only they can perform.

Estradiol Rapidly Attenuates ORL-1 Receptor-Mediated Inhibition of Proopiomelanocortin Neurons via Gq-Coupled, Membrane-Initiated Signaling.

Estradiol rapidly regulates the activity of arcuate nucleus (ARH) proopiomelanocortin (POMC) neurons that project to the medial preoptic nucleus (MPN) to regulate lordosis. Orphanin FQ/nociceptin (OFQ/N) acts via opioid receptor-like (ORL)-1 receptors to inhibit these POMC neurons. Therefore, we tested the hypothesis that estradiol excites POMC neurons by rapidly attenuating inhibitory ORL-1 signaling in these cells. Hypothalamic slices through the ARH were prepared from ovariectomized rats injected with Fluorogold into the MPN. Electrophysiological recordings were generated in ARH neurons held at or near -60 mV, and neuronal phenotype was determined post hoc by immunohistofluorescence. OFQ/N application induced robust outward currents and hyperpolarizations via G protein-gated, inwardly rectifying K+ (GIRK) channels that were attenuated by pretreatment with either 17-ß estradiol (E2) or E2 conjugated to bovine serum albumin. This was blocked by the estrogen receptor (ER) antagonist ICI 182,780 and mimicked by the Gq-coupled membrane ER (Gq-mER) ligand STX and the ERα agonist PPT. Inhibiting phosphatidylinositol-3-kinase (PI3K) blocked the estrogenic attenuation of ORL-1/GIRK currents. Antagonizing either phospholipase C (PLC), protein kinase C (PKC), protein kinase A (PKA) or neuronal nitric oxide synthase (nNOS) also abrogated E2 inhibition of ORL-1/GIRK currents, whereas activation of PKC, PKA, protein kinase B (Akt) and nNOS substrate L-arginine all attenuated the OFQ/N response. This was observed in 92 MPN-projecting, POMC-positive ARH neurons. Thus, ORL-1 receptor-mediated inhibition of POMC neurons is rapidly and negatively modulated by E2, an effect which is stereoselective and membrane initiated via Gq-mER and ERα activation that signals through PLC, PKC, PKA, PI3K and nNOS.

The role of AMP-activated protein kinase in the androgenic potentiation of cannabinoid-induced changes in energy homeostasis.

Orexigenic mediators can impact the hypothalamic feeding circuitry via the activation of AMP-dependent protein kinase (AMPK). Given that testosterone is an orexigenic hormone, we hypothesized that androgenic changes in energy balance are due to enhanced cannabinoid-induced inhibition of anorexigenic proopiomelanocortin (POMC) neurons via activation of AMPK. To this end, whole animal experiments were carried out in gonadectomized male guinea pigs treated subcutaneously with either testosterone propionate (TP; 400 µg) or its sesame oil vehicle (0.1 ml). TP-treated animals displayed increases in energy intake associated with increases in meal size. TP also increased several indices of energy expenditure as well as the p-AMPK/AMPK ratio in the arcuate nucleus (ARC) measured 2 and 24 h posttreatment. Subcutaneous administration of the CB1 receptor antagonist AM251 (3 mg/kg) rapidly blocked the hyperphagic effect of TP. This was mimicked largely upon third ventricular administration of AM251 (10 µg). Electrophysiological studies revealed that TP potentiated the ability of the cannabinoid receptor agonist WIN 55,212-2 to decrease the frequency of miniature excitatory postsynaptic currents in ARC neurons. TP also increased the basal frequency of miniature inhibitory postsynaptic currents. In addition, depolarization-induced suppression (DSE) is potentiated in cells from TP-treated animals and blocked by AM251. The AMPK inhibitor compound C attenuated DSE from TP-treated animals, whereas the AMPK activator metformin enhanced DSE from vehicle-treated animals. These effects occurred in a sizable number of identified POMC neurons. Collectively, these results indicate that the androgen-induced increases in energy intake are mediated via an AMPK-dependent augmentation in endocannabinoid tone onto POMC neurons.

Role of neuronal nitric oxide synthase in the estrogenic attenuation of cannabinoid-induced changes in energy homeostasis.

Since estradiol attenuates cannabinoid-induced increases in energy intake, energy expenditure, and transmission at proopiomelanocortin (POMC) synapses in the hypothalamic arcuate nucleus (ARC), we tested the hypothesis that neuronal nitric oxide synthase (nNOS) plays an integral role. To this end, whole animal experiments were carried out in gonadectomized female guinea pigs. Estradiol benzoate (EB; 10 µg sc) decreased incremental food intake as well as O2 consumption, CO2 production, and metabolic heat production as early as 2 h postadministration. This was associated with increased phosphorylation of nNOS (pnNOS), as evidenced by an elevated ratio of pnNOS to nNOS in the ARC. Administration of the cannabinoid receptor agonist WIN 55,212-2 (3 µg icv) into the third ventricle evoked hyperphagia as early as 1 h postadministration, which was blocked by EB and restored by the nonselective NOS inhibitor N-nitro-L-arginine methyl ester hydrochloride (L-NAME; 100 µg icv) when the latter was combined with the steroid. Whole cell patch-clamp recordings showed that 17ß-estradiol (E2; 100 nM) rapidly diminished cannabinoid-induced decreases in miniature excitatory postsynaptic current frequency, which was mimicked by pretreatment with the NOS substrate L-arginine (30 µM) and abrogated by L-NAME (300 µM). Furthermore, E2 antagonized endocannabinoid-mediated depolarization-induced suppression of excitation, which was nullified by the nNOS-selective inhibitor N5-[imino(propylamino)methyl]-L-ornithine hydrochloride (10 µM). These effects occurred in a sizable number of identified POMC neurons. Taken together, the estradiol-induced decrease in energy intake is mediated by a decrease in cannabinoid sensitivity within the ARC feeding circuitry through the activation of nNOS. These findings provide compelling evidence for the need to develop rational, gender-specific therapies to help treat metabolic disorders such as cachexia and obesity.

Practice transformation in the safety net medical home initiative: a qualitative look.

BACKGROUND: Transformation of primary care to patient-centered medical homes (PCMH) is challenging. Progress in transformation varied widely among practices involved in the Safety Net Medical Home Initiative. OBJECTIVE: To study 3 successful practices to identify common characteristics and approaches. RESEARCH DESIGN: We selected 3 diverse practices based on their improvement on the PCMH-A, a self-assessment instrument measuring progress toward becoming a PCMH. We interviewed 2-3 leaders from the each of 3 practices seeking information about their motivations for transforming, the methods used to make changes, and challenges and facilitators. Interview data were coded, themes developed, and conclusions drawn using qualitative research methods. RESULTS: For these successful practices, the major motivators were a desire to improve quality of care, patient experience, or provider experience. Financial incentives played a minor role. All practices had engaged, visible leaders driving change, and all ultimately developed an effective quality improvement/practice change strategy that included the provision of trusted performance data at the provider level and an explicit process change strategy. Sequencing the work of PCMH transformation was important, and developing defined provider patient panels and building effective clinical teams facilitated making improvements to access and care delivery. CONCLUSIONS: Practice transformation is disruptive. To be successful, organizations need to have the will or motivation to change, explicit ideas or models on which to base change, and a culture and infrastructure that enables the execution of system changes.

The safety net medical home initiative: transforming care for vulnerable populations.

BACKGROUND: Despite findings that medical homes may reduce or eliminate health care disparities among underserved and minority populations, most previous medical home pilot and demonstration projects have focused on health care delivery systems serving commercially insured patients and Medicare beneficiaries. OBJECTIVES: To develop a replicable approach to support medical home transformation among diverse practices serving vulnerable and underserved populations. DESIGN: Facilitated by a national program team, convening organizations in 5 states provided coaching and learning community support to safety net practices over a 4-year period. To guide transformation, we developed a framework of change concepts aligned with supporting tools including implementation guides, activity checklists, and measurement instruments. SUBJECTS: Sixty-five health centers, homeless clinics, private practices, residency training centers, and other safety net practices in Colorado, Idaho, Massachusetts, Oregon, and Pennsylvania. MEASURES: We evaluated implementation of the change concepts using the Patient-Centered Medical Home-Assessment, and conducted a survey of participating practices to assess perceptions of the impact of the technical assistance. RESULTS: All practices implemented key features of the medical home model, and nearly half (47.6%) implemented the 33 identified key changes to a substantial degree as evidenced by level A Patient-Centered Medical Home-Assessment scores. Two thirds of practices that achieved substantial implementation did so only after participating in the initiative for >2 years. By the end of the initiative, 83.1% of sites achieved external recognition as medical homes. CONCLUSIONS: Despite resource constraints and high-need populations, safety net clinics made considerable progress toward medical home implementation when provided robust, multimodal support over a 4-year period.