Design of potent and selective GPR119 agonists for type II diabetes.

Screening of the Merck sample collection identified compound 1 as a weakly potent GPR119 agonist (hEC(50)=3600 nM). Dual termini optimization of 1 led to compound 36 having improved potency, selectivity, and formulation profile, however, modest physical properties (PP) hindered its utility. Design of a new core containing a cyclopropyl restriction yielded further PP improvements and when combined with the termini SAR optimizations yielded a potent and highly selective agonist suitable for further preclinical development (58).

Identification of a potent synthetic FXR agonist with an unexpected mode of binding and activation.

The farnesoid X receptor (FXR), a member of the nuclear hormone receptor family, plays important roles in the regulation of bile acid and cholesterol homeostasis, glucose metabolism, and insulin sensitivity. There is intense interest in understanding the mechanisms of FXR regulation and in developing pharmaceutically suitable synthetic FXR ligands that might be used to treat metabolic syndrome. We report here the identification of a potent FXR agonist (MFA-1) and the elucidation of the structure of this ligand in ternary complex with the human receptor and a coactivator peptide fragment using x-ray crystallography at 1.9-A resolution. The steroid ring system of MFA-1 binds with its D ring-facing helix 12 (AF-2) in a manner reminiscent of hormone binding to classical steroid hormone receptors and the reverse of the pose adopted by naturally occurring bile acids when bound to FXR. This binding mode appears to be driven by the presence of a carboxylate on MFA-1 that is situated to make a salt-bridge interaction with an arginine residue in the FXR-binding pocket that is normally used to neutralize bound bile acids. Receptor activation by MFA-1 differs from that by bile acids in that it relies on direct interactions between the ligand and residues in helices 11 and 12 and only indirectly involves a protonated histidine that is part of the activation trigger. The structure of the FXR:MFA-1 complex differs significantly from that of the complex with a structurally distinct agonist, fexaramine, highlighting the inherent plasticity of the receptor.

Manual examination of the spine: a systematic critical literature review of reproducibility.

OBJECTIVE: Poor reproducibility of spinal palpation has been reported in previously published literature, and authors of recent reviews have posted criticism on study quality. This article critically analyzes the literature pertaining to the inter- and intraobserver reproducibility of spinal palpation to investigate the consistency of study results and assess the level of evidence for reproducibility. METHODS: Systematic review and meta-analysis were performed on relevant literature published from 1965 to 2005, identified using the electronic databases MEDLINE, MANTIS, and CINAHL and checking of reference lists. Descriptive data from included articles were extracted independently by 2 reviewers. A 6-point scale was constructed to assess the methodological quality of original studies. A meta-analysis was conducted among the high-quality studies to investigate the consistency of data, separately on motion palpation, static palpation, osseous pain, soft tissue pain, soft tissue changes, and global assessment. A standardized method was used to determine the level of evidence. RESULTS: The quality score of 48 included studies ranged from 0% to 100%. There was strong evidence that the interobserver reproducibility of osseous and soft tissue pain is clinically acceptable (kappa > or = 0.4) and that intraobserver reproducibility of soft tissue pain and global assessment are clinically acceptable. Other spinal procedures are either not reproducible or the evidence is conflicting or preliminary.

Peroxisome proliferator-activated receptor (PPAR)-alpha agonism prevents the onset of type 2 diabetes in Zucker diabetic fatty rats: A comparison with PPAR gamma agonism.

Peroxisome proliferator-activated receptor (PPAR)-gamma agonists are insulin sensitizers, whereas PPAR alpha agonists are lipid-lowering agents in humans. Chronic treatment with PPAR gamma agonists has been shown to prevent the onset of diabetes in young Zucker diabetic fatty (ZDF) rats; however, the effects of PPAR alpha agonists have not been well characterized in this model. Here we investigated chronic efficacy of PPAR alpha and nonthiazolidinedione (nTZD) PPAR gamma agonists on the onset of diabetes in 6-wk-old male ZDF rats. Whereas treatment with the nTZD PPAR gamma agonist completely prevented development of hyperglycemia, PPAR alpha activation was associated with lowering of food intake and body weight and reductions in fed and fasting hyperglycemia, with prevention of the hyperinsulinemic peak preceding the development of hyperglycemia in ZDF rats. Both compounds improved glucose tolerance during an oral glucose tolerance test with concomitant increases in insulin response. Such improvements of insulin secretion were associated with increased islet to total pancreatic area ratio and pancreatic insulin contents. Hyperinsulinemic-euglycemic clamp studies demonstrated that nTZD PPAR gamma reduced basal endogenous glucose production and increased insulin-stimulated glucose disposal, consistent with an improved insulin action as a cause of the improved glucose homeostasis. In contrast, activation of PPAR alpha did not significantly improve glucose metabolism during the hyperinsulinemic-euglycemic clamp. In conclusion, chronic treatment of ZDF rats with a PPAR gamma agonist completely prevented the onset of diabetes by improving both insulin action and secretion, whereas PPAR alpha agonism was partially effective, primarily by improving the pancreatic islet insulin response. Unlike the PPAR gamma agonist, the PPAR alpha agonist demonstrated efficacy without inducing body weight gain and cardiomegaly. This study suggests a possible role for PPAR alpha agonists in the prevention of type 2 diabetes mellitus.

SAR studies: designing potent and selective LXR agonists.

Counterscreening compounds from a Merck PPAR program discovered lead 1, as a nanomolar LXR/PPAR dual agonist. SAR optimization developed a series of heterocyclic LXR agonists having excellent selectivity over all PPAR isoforms and possessing high LXR affinity and strong in vivo potency.

Different roles of liver X receptor alpha and beta in lipid metabolism: effects of an alpha-selective and a dual agonist in mice deficient in each subtype.

Liver X receptor (LXR) alpha and LXRbeta are closely related nuclear receptors that respond to elevated levels of intracellular cholesterol by enhancing transcription of genes that control cholesterol efflux and fatty acid biosynthesis. The consequences of inactivation of either LXR isoform have been thoroughly studied, as have the effects of simultaneous activation of both LXRalpha and LXRbeta by synthetic compounds. We here describe the effects of selective activation of LXRalpha or LXRbeta on lipid metabolism. This was accomplished by treating mice genetically deficient in either LXRalpha or LXRbeta with an agonist with equal potency for both isoforms (Compound B) or a synthetic agonist selective for LXRalpha (Compound A). We also determined the effect of these agonists on gene expression and cholesterol efflux in peritoneal macrophages derived from wild-type and knockout mice. Both compounds raised HDL-cholesterol and increased liver triglycerides in wild-type mice; in contrast, in mice deficient in LXRalpha, Compound B increased HDL-cholesterol but did not cause hepatic steatosis. Compound B induced ATP-binding cassette transporter (ABC) A1 expression and stimulated cholesterol efflux in macrophages from both LXRalpha and LXRbeta-deficient mice. Our data lend further experimental support to the hypothesis that LXRbeta-selective agonists may raise HDL-cholesterol and stimulate macrophage cholesterol efflux without causing liver triglyceride accumulation.

Writing narrative literature reviews for peer-reviewed journals: secrets of the trade.

OBJECTIVE: To describe and discuss the process used to write a narrative review of the literature for publication in a peer-reviewed journal. Publication of narrative overviews of the literature should be standardized to increase their objectivity. BACKGROUND: In the past decade numerous changes in research methodology pertaining to reviews of the literature have occurred. These changes necessitate authors of review articles to be familiar with current standards in the publication process. METHODS: Narrative overview of the literature synthesizing the findings of literature retrieved from searches of computerized databases, hand searches, and authoritative texts. DISCUSSION: An overview of the use of three types of reviews of the literature is presented. Step by step instructions for how to conduct and write a narrative overview utilizing a 'best-evidence synthesis' approach are discussed, starting with appropriate preparatory work and ending with how to create proper illustrations. Several resources for creating reviews of the literature are presented and a narrative overview critical appraisal worksheet is included. A bibliography of other useful reading is presented in an appendix. CONCLUSION: Narrative overviews can be a valuable contribution to the literature if prepared properly. New and experienced authors wishing to write a narrative overview should find this article useful in constructing such a paper and carrying out the research process. It is hoped that this article will stimulate scholarly dialog amongst colleagues about this research design and other complex literature review methods.

Reliability of spinal palpation for diagnosis of back and neck pain: a systematic review of the literature.

STUDY DESIGN: A systematic review. OBJECTIVES: To determine the quality of the research and assess the interexaminer and intraexaminer reliability of spinal palpatory diagnostic procedures. SUMMARY OF BACKGROUND DATA: Conflicting data have been reported over the past 35 years regarding the reliability of spinal palpatory tests. METHODS: The authors used 13 electronic databases and manually searched the literature from January 1, 1966 to October 1, 2001. Forty-nine (6%) of 797 primary research articles met the inclusion criteria. Two blinded, independent reviewers scored each article. Consensus or a content expert reconciled discrepancies. RESULTS: The quality scores ranged from 25 to 79/100. Subject description, study design, and presentation of results were the weakest areas. The 12 highest quality articles found pain provocation, motion, and landmark location tests to have acceptable reliability (K = 0.40 or greater), but they were not always reproducible by other examiners under similar conditions. In those that used kappa statistics, a higher percentage of the pain provocation studies (64%) demonstrated acceptable reliability, followed by motion studies (58%), landmark (33%), and soft tissue studies (0%). Regional range of motion is more reliable than segmental range of motion, and intraexaminer reliability is better than interexaminer reliability. Overall, examiners' discipline, experience level, consensus on procedure used, training just before the study, or use of symptomatic subjects do not improve reliability. CONCLUSION: The quality of the research on interreliability and intrareliability of spinal palpatory diagnostic procedures needs to be improved. Pain provocation tests are most reliable. Soft tissue paraspinal palpatory diagnostic tests are not reliable.

Treatment of bioprosthetic heart valve tissue with long chain alcohol solution to lower calcification potential.

The use of glutaraldehyde-treated biological tissue in heart valve substitutes is an important option in the treatment of heart valve disease. These devices have limited durability, in part, because of tissue calcification and subsequent tearing of the valve leaflets. Components thought to induce calcification include lipids, cell remnants, and residual glutaraldehyde. We hypothesized that treatment of glutaraldehyde-treated bioprosthetic heart valve material using a short and long chain alcohol (LCA) combination, composed of 5% 1,2-octanediol in an ethanolic buffered solution, would reduce phospholipid content and subsequently lower the propensity of these tissues to calcify in vivo. Phospholipid content of glutaraldehyde-treated porcine valve leaflets and bovine pericardium was found to be 10.1 +/- 4.3 (n = 7) and 3.9 +/- 0.48 (n = 2) microg/mg dry tissue, respectively, which was reduced to 0.041 +/- 0.06 (n = 7) and 0.21 +/- 0.05 (n = 4) microg/mg dry tissue, respectively, after LCA treatment. Calcification potential of the treated tissues was assessed using a rat subcutaneous implant model. After 60 days of implantation, calcium levels were found to be 171 +/- 32 (n = 11) and 83 +/- 70 (n = 12) mg/g dry weight for glutaraldehyde-treated porcine leaflets and bovine pericardium, respectively, whereas prior LCA treatment resulted in reduced calcium levels of 1.1 +/- 0.6 (n = 12) and 0.82 +/- 0.1 (n = 12) mg/g dry weight, respectively. These data, taken together, support the notion that treatment of glutaraldehyde-treated tissue with a short and long chain alcohol combination will reduce both extractable phospholipids and the propensity for in vivo calcification.

O-arylmandelic acids as highly selective human PPAR alpha/gamma agonists.

A new class of O-arylmandelic acid PPAR agonists show excellent anti-hyperglycemic efficacy in a db/db mouse model of DM2. These PPARalpha-weighted agonists do not show the typical PPARgamma associated side effects of BAT proliferation and cardiac hypertrophy in a rat tolerability assay.

Spinal palpation: The challenges of information retrieval using available databases.

PURPOSE: This study addressed 2 questions: first, what is the yield of PubMed MEDLINE for complementary and alternative medicine (CAM) studies compared to other databases; second, what is an effective search strategy to answer a sample research question on spinal palpation? METHODS: We formulated the following research question: "What is the reliability of spinal palpation procedures?" We identified specific Medical Subject Headings (MeSH) and key terms as used in osteopathic medicine, allopathic medicine, chiropractic, and physical therapy. Using PubMed, we formulated an initial search template and applied it to 12 additional selected databases. Subsequently, we applied the inclusion criteria and evaluated the yield in terms of precision and sensitivity in identifying relevant studies. RESULTS: The online search result of the 13 databases identified 1189 citations potentially addressing the research question. After excluding overlapping and nonpertinent citations and those not meeting the inclusion criteria, 49 citations remained. PubMed yielded 19, while MANTIS (Manual Alternative and Natural Therapy Index System), a manual therapy database, yielded 35 citations. Twenty-six of the 49 online citations were repeatedly indexed in 3 or more databases. Content experts and selective manual searches identified 11 additional studies. In all, we identified 60 studies that addressed the research question. The cost of the databases used for conducting this search ranged from free-of-charge to $43,000 per year for a single network subscription. CONCLUSIONS: Commonly used databases often do not provide accurate indexing or coverage of CAM publications. Subject-specific specialized databases are recommended. Access, cost, and ease of using specialized databases are limiting factors.

Searching biomedical databases on complementary medicine: the use of controlled vocabulary among authors, indexers and investigators.

BACKGROUND: The optimal retrieval of a literature search in biomedicine depends on the appropriate use of Medical Subject Headings (MeSH), descriptors and keywords among authors and indexers. We hypothesized that authors, investigators and indexers in four biomedical databases are not consistent in their use of terminology in Complementary and Alternative Medicine (CAM). METHODS: Based on a research question addressing the validity of spinal palpation for the diagnosis of neuromuscular dysfunction, we developed four search concepts with their respective controlled vocabulary and key terms. We calculated the frequency of MeSH, descriptors, and keywords used by authors in titles and abstracts in comparison to standard practices in semantic and analytic indexing in MEDLINE, MANTIS, CINAHL, and Web of Science. RESULTS: Multiple searches resulted in the final selection of 38 relevant studies that were indexed at least in one of the four selected databases. Of the four search concepts, validity showed the greatest inconsistency in terminology among authors, indexers and investigators. The use of spinal terms showed the greatest consistency. Of the 22 neuromuscular dysfunction terms provided by the investigators, 11 were not contained in the controlled vocabulary and six were never used by authors or indexers. Most authors did not seem familiar with the controlled vocabulary for validity in the area of neuromuscular dysfunction. Recently, standard glossaries have been developed to assist in the research development of manual medicine. CONCLUSIONS: Searching biomedical databases for CAM is challenging due to inconsistent use of controlled vocabulary and indexing procedures in different databases. A standard terminology should be used by investigators in conducting their search strategies and authors when writing titles, abstracts and submitting keywords for publications.

Content validity of manual spinal palpatory exams - A systematic review.

BACKGROUND: Many health care professionals use spinal palpatory exams as a primary and well-accepted part of the evaluation of spinal pathology. However, few studies have explored the validity of spinal palpatory exams. To evaluate the status of the current scientific evidence, we conducted a systematic review to assess the content validity of spinal palpatory tests used to identify spinal neuro-musculoskeletal dysfunction. METHODS: Review of eleven databases and a hand search of peer-reviewed literature, published between 1965-2002, was undertaken. Two blinded reviewers abstracted pertinent data from the retrieved papers, using a specially developed quality-scoring instrument. Five papers met the inclusion/exclusion criteria. RESULTS: Three of the five papers included in the review explored the content validity of motion tests. Two of these papers focused on identifying the level of fixation (decreased mobility) and one focused on range of motion. All three studies used a mechanical model as a reference standard. Two of the five papers included in the review explored the validity of pain assessment using the visual analogue scale or the subjects' own report as reference standards. Overall the sensitivity of studies looking at range of motion tests and pain varied greatly. Poor sensitivity was reported for range of motion studies regardless of the examiner's experience. A slightly better sensitivity (82%) was reported in one study that examined cervical pain. CONCLUSIONS: The lack of acceptable reference standards may have contributed to the weak sensitivity findings. Given the importance of spinal palpatory tests as part of the spinal evaluation and treatment plan, effort is required by all involved disciplines to create well-designed and implemented studies in this area.

Effects of treatment protocols and subcutaneous implantation on bovine pericardium: a Raman spectroscopy study.

Using Raman microspectroscopy, we have studied mineral deposition on bovine pericardia, fixed according to three different protocols and either implanted subcutaneously or not implanted (controls). A lightly carbonated apatitic phosphate mineral, similar to that found in bone tissue, was deposited on the surface of a glutaraldehyde-fixed, implanted pericardium. Implanted pericardia fixed in glutaraldehyde followed by treatment in either an 80% ethanol or a 5% octanol/40% ethanol solution did not mineralize on implantation. Collagen secondary structure changes were observed on glutaraldehyde fixation by monitoring the center of gravity of the amide I envelope. It is proposed that the decrease in the amide I center of gravity frequency for the glutaraldehyde-fixed tissue compared to the nonfixed tissue is due to an increase in nonreducible collagen cross-links (1660 cm(-1)) and a decrease in reducible cross-links (1690 cm(-1)). The amide I center of gravity in the glutaraldehyde/ethanol-fixed pericardium was higher than the glutaraldehyde-fixed tissue center of gravity. This increase in center of gravity could possibly be due to a decrease in hydrogen bonding within the collagen fibrils following the ethanol pretreatment. In addition, we found a secondary structure change to the pericardial collagen after implantation: an increase in the frequency of the center of gravity of amide I is indicative of an increase in cross-links.

Amphipathic 3-phenyl-7-propylbenzisoxazoles; human pPaR gamma, delta and alpha agonists.

A series of amphipathic 3-phenylbenzisoxazoles were found to be potent agonists of human PPARalpha, gamma and delta. The optimization of acid proximal structure for in vitro and in vivo potency is described. Results of po dosed efficacy studies in the db/db mouse model of type 2 diabetes showed efficacy equal or superior to Rosiglitazone in correcting hyperglycemia and hypertriglyceridemia. Good functional receptor selectivity for PPARalpha and gamma over PPARdelta can be obtained.

Distinct properties and advantages of a novel peroxisome proliferator-activated protein [gamma] selective modulator.

Antidiabetic thiazolidinediones (TZDs) and non-TZD compounds have been shown to serve as agonists of the peroxisome proliferator-activated receptor gamma (PPARgamma). Here, we report the identification and characterization of a novel non-TZD selective PPARgamma modulator (nTZDpa). nTZDpa bound potently to PPARgamma with high selectivity vs. PPARalpha or PPARdelta. In cell-based assays for transcriptional activation, nTZDpa served as a selective, potent PPARgamma partial agonist and was able to antagonize the activity of PPARgamma full agonists. nTZDpa also displayed partial agonist effects when its ability to promote adipogenesis in 3T3-L1 cells was evaluated. Assessment of protein conformation using protease protection or solution nuclear magnetic resonance spectroscopy methods showed that nTZDpa produced altered PPARgamma conformational stability vs. full agonists, thereby establishing a physical basis for its observed partial agonism. DNA microarray analysis of RNA from 3T3-L1 adipocytes treated with nTZDpa or several structurally diverse PPARgamma full agonists demonstrated qualitative differences in the affected gene expression profile for nTZDpa. Chronic treatment of fat-fed, C57BL/6J mice with nTZDpa or a TZD full agonist ameliorated hyperglycemia and hyperinsulinemia. However, unlike the TZD, nTZDpa caused reductions in weight gain and adipose depot size. Feed efficiency was also substantially diminished. Unlike TZDs, nTZDpa did not cause cardiac hypertrophy in mice. When a panel of PPARgamma target genes was examined in white adipose tissue, nTZDpa produced a different in vivo expression pattern vs. the full agonist. These findings establish that novel selective PPARgamma modulators can produce altered receptor conformational stability leading to distinctive gene expression profiles, reduced adipogenic cellular effects, and potentially improved in vivo biological responses. Such compounds may lead to preferred therapies for diabetes, obesity, or metabolic syndrome.

Miniaturization of cell-based beta-lactamase-dependent FRET assays to ultra-high throughput formats to identify agonists of human liver X receptors.

Activation of liver X receptors (LXRs) induces reverse cholesterol transport and increases high-density lipoprotein cholesterol in vivo. Here, we describe novel, functional, homogeneous cell-based fluorescence resonance energy transfer assays for identifying agonists of LXRs using beta-lactamase as the reporter gene. Stable Chinese hamster ovary cell lines expressing LXRalpha-GAL4 or LXRbeta-GAL4 fusion proteins that regulate beta-lactamase transcription from upstream 7 x UAS GAL4 DNA binding sequences were generated and characterized. Synthetic and natural ligands of LXR dose-dependently activated the expression of beta-lactamase in a subtype-specific manner. These assays were used to demonstrate that a 1-pyridyl hydantoin small molecule LXR synthetic ligand specifically activates LXRalpha receptors. The beta-lactamase assays were optimized for cell density, dimethyl sulfoxide sensitivity, and time of agonist stimulation. Clonal LXRbeta-GAL4-beta-lactamase cells were miniaturized into an ultra high throughput (3456-well nanoplates) screening format.

A randomized trial of medical care with and without physical therapy and chiropractic care with and without physical modalities for patients with low back pain: 6-month follow-up outcomes from the UCLA low back pain study.

STUDY DESIGN: A randomized clinical trial. OBJECTIVES: To compare the effectiveness of medical and chiropractic care for low back pain patients in managed care; to assess the effectiveness of physical therapy among medical patients; and to assess the effectiveness of physical modalities among chiropractic patients. SUMMARY OF BACKGROUND DATA: Despite the burden that low back pain places on patients, providers, and society, the relative effectiveness of common treatment strategies offered in managed care is unknown. METHODS: Low back pain patients presenting to a large managed care facility from October 30, 1995, through November 9, 1998, were randomly assigned in a balanced design to medical care with and without physical therapy and to chiropractic care with and without physical modalities. The primary outcome variables are average and most severe low back pain intensity in the past week, assessed with 0 to 10 numerical rating scales, and low back-related disability, assessed with the 24-item Roland-Morris Disability Questionnaire. RESULTS: Of 1,469 eligible patients, 681 were enrolled; 95.7% were followed through 6 months. The mean changes in low back pain intensity and disability of participants in the medical and chiropractic care-only groups were similar at each follow-up assessment (adjusted mean differences at 6 months for most severe pain, 0.27, 95% confidence interval, -0.32-0.86; average pain, 0.22, -0.25-0.69; and disability, 0.75, -0.29-1.79). Physical therapy yielded somewhat better 6-month disability outcomes than did medical care alone (1.26, 0.20-2.32). CONCLUSIONS: After 6 months of follow-up, chiropractic care and medical care for low back pain were comparable in their effectiveness. Physical therapy may be marginally more effective than medical care alone for reducing disability in some patients, but the possible benefit is small.

Comparing the satisfaction of low back pain patients randomized to receive medical or chiropractic care: results from the UCLA low-back pain study.

OBJECTIVES: This study examined the difference in satisfaction between patients assigned to chiropractic vs medical care for treatment of low back pain in a managed care organization. METHODS: Satisfaction scores (on a 10-50 scale) after 4 weeks of follow-up were compared among 672 patients randomized to receive medical or chiropractic care. RESULTS: The mean satisfaction score for chiropractic patients was greater than the score for medical patients (crude difference = 5.5; 95% confidence interval = 4.5, 6.5). Self-care advice and explanation of treatment predicted satisfaction and reduced the estimated difference between chiropractic and medical patients' satisfaction. CONCLUSIONS: Communication of advice and information to patients with low back pain increases their satisfaction with providers and accounts for much of the difference between chiropractic and medical patients' satisfaction.