Characteristics of undiagnosed diseases network applicants: implications for referring providers.

BACKGROUND: The majority of undiagnosed diseases manifest with objective findings that warrant further investigation. The Undiagnosed Diseases Network (UDN) receives applications from patients whose symptoms and signs have been intractable to diagnosis; however, many UDN applicants are affected primarily by subjective symptoms such as pain and fatigue. We sought to characterize presenting symptoms, referral sources, and demographic factors of applicants to the UDN to identify factors that may determine application outcome and potentially differentiate between those with undiagnosed diseases (with more objective findings) and those who are less likely to have an undiagnosed disease (more subjective symptoms). METHODS: We used a systematic retrospective review of 151 consecutive Not Accepted and 50 randomly selected Accepted UDN applications. The primary outcome was whether an applicant was Accepted, or Not Accepted, and, if accepted, whether or not a diagnosis was made. Objective and subjective symptoms and information on prior specialty consultations were collected from provider referral letters. Demographic data and decision data on network acceptance were gathered from the UDN online portal. RESULTS: Fewer objective findings and more subjective symptoms were found in the Not Accepted applications. Not Accepted referrals also were from older individuals, reported a shorter period of illness, and were referred to the UDN by their primary care physicians. All of these differences reached statistical significance in comparison with Accepted applications. The frequency of subspecialty consults for diagnostic purposes prior to UDN application was similar in both groups. CONCLUSIONS: The preponderance of subjective and lack of objective findings in the Not Accepted applications distinguish these from applicants that are accepted for evaluation and diagnostic efforts through the UDN. Not Accepted applicants are referred primarily by their primary care providers after multiple specialist consultations fail to yield answers. Distinguishing between patients with undiagnosed diseases with objective findings and those with primarily subjective findings can delineate patients who would benefit from further diagnostic processes from those who may have functional disorders and need alternative pathways for management of their symptoms. TRIAL REGISTRATION: clinicaltrials.gov NCT02450851 , posted May 21st 2015.

Developmental validation of the PowerPlex 16 HS System: an improved 16-locus fluorescent STR multiplex.

STR multiplexes remain the cornerstone of genotyping forensic samples. The PowerPlex 16 HS System contains the core CODIS loci: D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, CSF1PO, FGA, TH01, TPOX, and vWA. Additional loci amplified in the multiplex reaction are the sex-determinant locus, amelogenin, and two pentanucleotide STR loci, Penta D and Penta E. The PowerPlex 16 HS System is an updated version of the PowerPlex 16 System; while the primers and dyes remain unchanged, it introduces an enhanced buffer system that includes hot-start Taq DNA polymerase and ensures robust performance. Due to the modification of the reaction mix, a multi-laboratory developmental validation study was completed to document performance capabilities and limitations for the revised assay. Data within this validation was generated by eight laboratories and served as the basis for the following conclusions: genotyping of single-source samples was consistent across a large range of template DNA concentrations with most laboratories obtaining complete profiles at 62.5pg. Mixture analyses showed that over 90% of minor alleles were detected at 1:9 ratios. Optimum amplification cycle number was ultimately dependent on the sensitivity of the detection instrument and could be adjusted to accommodate a range of DNA template concentrations. Reaction conditions including volume and annealing temperature as well as the concentrations of primers, Taq DNA polymerase, and magnesium were shown to be optimal and able to withstand moderate variations without affecting multiplexed STR amplification. Finally, data from non-probative samples and concordance studies showed consistent results when comparing the PowerPlex 16 HS System with the PowerPlex 16 System as well as other commercially available systems.

Discovery and optimization of novel 4-[(aminocarbonyl)amino]-N-[4-(2-aminoethyl)phenyl]benzenesulfonamide ghrelin receptor antagonists.

This Letter describes optimization of ghrelin receptor antagonists and inverse agonists starting from a screening hit.

Discovery of betamethasone 17alpha-carbamates as dissociated glucocorticoid receptor modulators in the rat.

A series of betamethasone 17alpha-carbamates were designed, synthesized, and evaluated for their ability to dissociate the two main functions of the glucocorticoid receptor, that is, transactivation and transrepression, in rat cell lines. A number of alkyl substituted betamethasone 17alpha-carbamates were identified with excellent affinity for the glucocorticoid receptor (e.g., 7, GR IC(50) 5.1 nM) and indicated dissociated profiles in functional assays of transactivation (rat tyrosine aminotransferase, TAT, and rat glutamine synthetase, GS) and transrepression (human A549 cells, MMP-1 assay). Gratifyingly, the in-vivo profile of these compounds, for example, 7, also indicated potent anti-inflammatory activity with impaired effects on glucose, insulin, triglycerides, and body weight. Taken together, these results indicate that dissociated glucocorticoid receptor modulators can be identified in rodents.

Novel glucocorticoids containing a 6,5-bicyclic core fused to a pyrazole ring: synthesis, in vitro profile, molecular modeling studies, and in vivo experiments.

Chemistry was developed to synthesize the title series of compounds. The ability of these novel ligands to bind to the glucocorticoid receptor was investigated. These compounds were also tested in a series of functional assays and some were found to display the profile of a dissociated glucocorticoid. The SAR of the 6,5-bicyclic series differed markedly from the previously reported 6,6-series. Molecular modeling studies were employed to understand the conformational differences between the two series of compounds, which may explain their divergent activity. Two compounds were profiled in vivo and shown to reduce inflammation in a mouse model. An active metabolite is suspected in one case.

Ghrelin neutralization by a ribonucleic acid-SPM ameliorates obesity in diet-induced obese mice.

Ghrelin, an acylated peptide secreted from the stomach, acts as a short-term signal of nutrient depletion. Ghrelin is an endogenous ligand for the GH secretagogue receptor 1a, a G protein-coupled receptor expressed in the hypothalamus and pituitary. We used a synthetic oligonucleotide, NOX-B11-2, capable of specific high-affinity binding to bioactive ghrelin to determine whether ghrelin neutralization would alter indices of energy balance in vivo. This novel type of ghrelin-blocking agent, called an RNA Spiegelmer (SPM), is a polyethylene glycol-modified l-RNA oligonucleotide, the nonnatural configuration of which confers in vivo stability. NOX-B11-2 blocked ghrelin mediated activation of GH secretagogue receptor 1a in cell culture (IC50 approximately 5 nm). We explored the effects of acute NOX-B11-2 administration on ghrelin-induced feeding in mice. NOX-B11-2 (66 mg/kg, sc) blocked ghrelin-induced feeding and was without effect on feeding evoked by an orally active nonpeptide ghrelin receptor agonist. We demonstrated that selective ghrelin blockade effectively promoted weight loss in diet-induced obese (DIO) mice. Chronic infusion of NOX-B11-2 (33 mg/kg.d, sc) to DIO mice evoked body weight loss for 13 d and reduced food intake and fat mass relative to control SPM-infused mice. In a 7-d study, DIO mice infused with NOX-B11-2 (33 mg/kg.d, sc) showed body weight loss, compared with animals receiving control SPM. This effect was directly mediated by SPM neutralization of ghrelin because NOX-B11-2 administration to ghrelin-deficient mice resulted in no weight loss. The decreased obesity observed in SPM-treated DIO mice provides validation for ghrelin neutralization as a potential antiobesity therapy.

Novel ketal ligands for the glucocorticoid receptor: in vitro and in vivo activity.

A novel series of selective ligands for the human glucocorticoid receptor is described. Structure-activity studies focused on variation of B-ring size, ketal ring size, and ketal substitution. These analogs were found to be potent and selective ligands for GR and have partial agonist profiles in functional assays for transactivation (TAT, GS) and transrepression (IL-6). Of these compounds, 27, 28, and 35 were evaluated further in a mouse LPS-induced TNF-alpha secretion model. Compound 28 had an ED(50) of 14.1 mg/kg compared with 0.5 mg/kg for prednisolone in the same assay.

Novel heterocyclic glucocorticoids: in vitro profile and in vivo efficacy.

A series of novel ligands for the glucocorticoid receptor containing two heterocycles were synthesized. These compounds were investigated for a dissociative profile using transrepression and transactivation assays. Several compounds were tested in vivo and showed the ability to reduce inflammation in a mouse.

Novel N-arylpyrazolo[3,2-c]-based ligands for the glucocorticoid receptor: receptor binding and in vivo activity.

A novel series of selective ligands for the human glucocorticoid receptor (hGR) are described. Preliminary structure-activity relationships were focused on substitution at C-1 and indicated a preference for 3-, 4-, and 5-substituted aromatic and benzylic groups. The resulting analogues, e.g., 18 and 34, exhibited excellent affinity for hGR (IC(50) 1.9 nM and 2.8 nM, respectively) and an interesting partial agonist profile in functional assays of transactivation (tyrosine aminotransferase, TAT, and glutamine synthetase, GS) and transrepression (IL-6). The most potent compounds described in this study were the tertiary alcohol derivatives 21 and 25. These candidates showed highly efficacious IL-6 inhibition versus dexamethasone. The thiophenyl analogue 25 was evaluated in vivo in the mouse LPS challenge model and showed an ED(50) = 4.0 mg/kg, compared to 0.5 mg/kg for prednisolone in the same assay.

Selective glucocorticoid receptor nonsteroidal ligands completely antagonize the dexamethasone mediated induction of enzymes involved in gluconeogenesis and glutamine metabolism.

Glucocorticoids (GCs) are vital multi-faceted hormones with recognized effects on carbohydrate, protein and lipid metabolism. Previous studies with the steroid antagonist, RU486 have underscored the essential role of GCs in the regulation of these metabolic pathways. This article describes the discovery and characterization of novel GRalpha selective nonsteroidal antagonists (NSGCAs). NSGCAs 2 and 3 are spirocyclic dihydropyridine derivatives that selectively bind the GRalpha with IC(50s) of 2 and 1.5 nM, respectively. Importantly, these compounds are full antagonists of the induction by dexamethasone (Dex) of marker genes for glucose and glutamine metabolism; the tyrosine amino transferase (TAT) and glutamine synthetase (GS) enzymes, respectively. In contrast, GC-dependent transcriptional repression of the collagenase 1 (MMP-1) enzyme, an established GRalpha responsive proinflammatory gene; is poorly antagonized by these compounds. These NSGCAs might have useful applications as tools in metabolic research and drug discovery.

The structure of Neurospora crassa 3-carboxy-cis,cis-muconate lactonizing enzyme, a beta propeller cycloisomerase.

Muconate lactonizing enzymes (MLEs) convert cis,cis-muconates to muconolactones in microbes as part of the beta-ketoadipate pathway; some also dehalogenate muconate derivatives of xenobiotic haloaromatics. There are three different MLE classes unrelated by evolution. We present the X-ray structure of a eukaryotic MLE, Neurospora crassa 3-carboxy-cis,cis-muconate lactonizing enzyme (NcCMLE) at 2.5 A resolution, with a seven-bladed beta propeller fold. It is related neither to bacterial MLEs nor to other beta propeller enzymes, but is structurally similar to the G protein beta subunit. It reveals a novel metal-independent cycloisomerase motif unlike the bacterial metal cofactor MLEs. Together, the bacterial MLEs and NcCMLE structures comprise a striking structural example of functional convergence in enzymes for 1,2-addition-elimination of carboxylic acids. NcCMLE and bacterial MLEs may enhance the reaction rate differently: the former by electrophilic catalysis and the latter by electrostatic stabilization of the enolate.

Purification of geranylgeranyltransferase I from Candida albicans and cloning of the CaRAM2 and CaCDC43 genes encoding its subunits.

All previously characterized protein geranylgeranyltransferases I (GGTase I) are heterodimeric zinc metalloenzymes which catalyse geranylgeranylation of a cysteine residue in proteins containing a C-terminal CaaL motif (C, Cys; a, aliphatic amino acid; L, Leu). The alpha and beta subunits of GGTase I of Saccharomyces cerevisiae are encoded by RAM2 and CDC43, respectively, and are essential for yeast viability. The authors are therefore investigating the role of geranylgeranylation in the related pathogenic yeast, Candida albicans, which is the most prevalent human fungal pathogen. GGTase I was purified to near homogeneity and also found to be a heterodimeric magnesium-dependent, zinc metalloenzyme displaying selectivity for CaaL-containing protein substrates. GGTase I peptide sequences were obtained from the purified protein and used to clone the genes encoding both subunits. CaRAM2 and CaCDC43 encode proteins that are 42 and 34% identical to their corresponding S. cerevisiae homologues, respectively, and 30% identical to their human homologues. Despite the limited overall homology, key zinc- and substrate-binding residues of the beta subunit (Cdc43p) are conserved. A unique feature of CaCdc43p is a tract of polyasparagine whose length varies from 6 to 17 residues among C. albicans strains and between alleles. Coexpression of both CaCDC43 and CaRAM2 under their native promoters complemented the ts defect of a S. cerevisiae cdc43 mutant but expression of the beta-subunit alone did not correct the growth defect, suggesting that hybrid GGTase I heterodimers are nonfunctional.