Potent and Selective Tetrahydroisoquinoline Kappa Opioid Receptor Antagonists of Lead Compound (3 R)-7-Hydroxy- N-[(1 S)-2-methyl-1-(piperidin-1-ylmethyl)propyl]-1,2,3,4-tetrahydroisoquinoline-3-carboxamide (PDTic)

Past studies have shown that it has been difficult to discover and develop potent and selective κ opioid receptor antagonists, particularly compounds having potential for clinical development. In this study, we present a structure-activity relationship (SAR) study of a recently discovered new class of tetrahydroisoquinoline κ opioid receptor antagonists which led to (3 R)-7-hydroxy- N-{(1 S)-2-methyl-1-[(-4-methylpiperidine-1-yl)methyl]propyl}-1,2,3,4-tetrahydroisoquinoline-3-carboxamide (12) (4-Me-PDTic). Compound 12 had a K_e = 0.37 nM in a [³⁵S]GTPγS binding assay and was 645- and >8100-fold selective for the κ relative to the μ and δ opioid receptors, respectively. Calculated log BB and CNS (central nervous system) multiparameter optimization (MPO) and low molecular weight values all predict that 12 will penetrate the brain, and pharmacokinetic studies in rats show that 12 does indeed penetrate the brain.

Potent and Selective Tetrahydroisoquinoline Kappa Opioid Receptor Antagonists of Lead Compound (3 R)- N-[1 R)-1-(Cyclohexylmethyl)-2-methylpropyl]-7-hydroxy-1,2,3,4-tetrahydroisoquinoline-3-carboxamide (CDTic)

Animal pharmacological studies suggest that potent and selective κ opioid receptor antagonists have potential as pharmacotherapies targeting depression, anxiety, and substance abuse (opiates, alcohol, nicotine, cocaine). We recently reported lead compound 1 as a new class of κ opioid receptor antagonists with only one basic amine group. Analogues were synthesized and evaluated for their in vitro opioid receptor antagonist properties using a [³⁵S]GTPγS binding assay. All analogues were pure opioid receptor antagonists with no agonist activity. Compounds 1, 8, 9, 13, and 14 ( K_e values 0.058-0.64 nM) are highly potent and highly selective for the κ relative to the μ and δ opioid receptors. Favorable calculated physiochemical properties were confirmed in rat PK studies, demonstrating brain penetration for selected compounds 1, 9, and 13. High κ opioid receptor potency and selectivity and highly favorable calculated physiochemical and PK properties for brain penetration suggest these compounds should be considered for further development.

How people who self-harm negotiate the inpatient environment: the mental healthcare workers perspective

WHAT IS KNOWN ABOUT THE SUBJECT?: Self-harm plays a function, commonly in the form of distress management. There has been little focussed exploration of how individuals who use self-harm to manage distress cope when prevented from self-harm in an inpatient environment and how staff respond to this issue.

WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE

This paper uses the experiences of mental health staff to add to the existing knowledge that self-harm has a functional role and supports the notion that interventions for self-harm should focus on the origins of distress. It describes the potential consequences that focussing on prevention of self-harm as opposed to actually managing distress may have on service-users, how staff attempt to manage these consequences and factors that may impact on staff interventions to prevent further distress/harm. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: The findings suggest that mental healthcare staff should aim to understand the function of self-harm, use this understanding to develop an individualized care plan with the aim of managing distress and identify barriers to the effectiveness of the interventions so they can be worked around.

ABSTRACT

Introduction Literature describes self-harm as functional and meaningful. This creates difficulties for service-users detained in an inpatient environment where self-harm is prevented. Aim Mental healthcare staff were interviewed to build on existing evidence of issues with the prevention approach and explore, from a staff perspective, how self-harm prevention impacts on service-users, how they manage distress and how this impacts on staff and their approach to care. Methods Qualitative methods were used to allow unexpected themes to arise. Ten semi-structured interviews were carried out with mental healthcare staff and thematically analysed. Findings and discussion The findings provide new evidence on the benefits and limitations of the inpatient environment for individuals who self-harm. Findings indicate that being unable to self-harm can lead to a continuation of distress and subsequent potentially harmful attempts to manage distress. Staff described experiencing a struggle for control in preventing self-harm, leading to increasingly harmful methods of self-harm. Alternatively some staff were able to support service-users with distress management. We discuss factors influencing which of these 'paths' service-users followed. Implications Considerations for care planning including understanding self-harm, using individualized care planning and attending to barriers are outlined with the ultimate aim of reducing distress and the impact of prevention of self-harm.

Simple Tetrahydroisoquinolines Are Potent and Selective Kappa Opioid Receptor Antagonists

Potent and selective κ opioid receptor antagonists have been derived from the N-substituted trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidine class of pure opioid receptor antagonists. In order to determine if the 3-hydroxyphenyl and/or the piperidine amino groups are required for obtaining the pure opioid antagonists, (3R)-7-hydroxy-N-[(1S)-2-methyl-1-(piperidine-1-ylmethyl)propyl]-1,2,3,4-tetrahydroiosquinoline-3-carboxamide (1), which does not have a 4-(3-hydroxyphenyl) group, and (3R)-N-(1R)-1-(cyclohexylmethyl)-2-methylpropyl]-7-hydroxy-1,2,3,4-tetrahydroisoquinoline-3-carboxamide (2), which does not have a 4-hydroxylphenyl or a piperidine amino group, were synthesized and evaluated for their [³⁵S]GTPγS binding properties at the μ, δ, and κ opioid receptors. Surprisingly compound 1 remained a pure opioid antagonist with a K_e = 6.80 nM at the κ opioid receptor and is 21- and 441-fold selective for the κ receptor relative to the μ and δ opioid receptors, respectively. Even more unexpected and novel is the finding that 2 has a K_e = 0.14 nM at κ and is 1730- and 4570-fold selective for κ relative to the μ and δ opioid receptors, respectively.

Identification of 2-({[1-(4-Fluorophenyl)-5-(2-methoxyphenyl)-1H-pyrazol-3-yl]carbonyl}amino)tricyclo[3.3.1.13,7]decane-2-carboxylic Acid (NTRC-844) as a Selective Antagonist for the Rat Neurotensin Receptor Type 2

Neurotensin receptor type 2 (NTS2) compounds display analgesic activity in animal pain models. We have identified the first high-affinity NTS2-selective antagonist (8) that is active in vivo. This study also revealed that the NTS2 FLIPR assay designation for a compound, agonist, partial agonist, and so forth, did not correlate with its in vivo activity as observed in the thermal tail-flick acute model of pain. This suggests that calcium mobilization is not the signaling pathway involved in NTS2-mediated analgesia as assessed by the thermal tail-flick model. Finally, we found a significant bias between rat and human for compound 9 in the NTS2 binding assay.

Strategic Issue Analysis: NGT + Decision Analysis for Resolving Strategic Issues

This article discusses how nominal group technique (NGT) can be combined with a decision analysis (DA) technique-simple multi-attribute utility-to assist decision makers in dealing with strategic issues. The authors identify a stepwise means of guiding such complex, "messy" issues through multiple levels so that organization-level alternatives can be considered without sacrificing unit-specific needs. A detailed case study is presented in which an organization consisting of many independently functioning divisions and subdivisions used NGT + DA along with group decision methodology to devise and choose from among alternatives for an integrated computer system. The organization was able to achieve consensus as to the system adopted, and informal and survey feedback from participants indicates their satisfaction with the process. The authors conclude that NGT + DA is relatively easy and inexpensive to use and transparent to the user, and call for research to assess its relative strengths compared to other combined techniques using NGT.

The Use of Ordinal Time-Series Analysis In Assessing Policy Inputs and Impacts

In recent years, analysts have relied more heavily on time-series methodologies to evaluate the effects of public policies. This article describes ordinal time-series analysis (OTSA), a technique originally developed to analyze the behavior of business firms. OTSA is a descriptive tool. Its advantages are that it uses ordinal data and eliminates the need for selecting appropriate discount factors. The use of OTSA in public policy analysis is illustrated through an assessment of the relationship between social welfare expenditures and infant mortality rates at state, regional, and national levels.

ML314: A Biased Neurotensin Receptor Ligand for Methamphetamine Abuse

Pharmacological treatment for methamphetamine addiction will provide important societal benefits. Neurotensin receptor NTR1 and dopamine receptor distributions coincide in brain areas regulating methamphetamine-associated reward, and neurotensin peptides produce behaviors opposing psychostimulants. Therefore, undesirable methamphetamine-associated activities should be treatable with druggable NTR1 agonists, but no such FDA-approved therapeutics exist. We address this limitation with proof-of-concept data for ML314, a small-molecule, brain penetrant, β-arrestin biased, NTR1 agonist. ML314 attenuates amphetamine-like hyperlocomotion in dopamine transporter knockout mice, and in C57BL/6J mice it attenuates methamphetamine-induced hyperlocomotion, potentiates the psychostimulant inhibitory effects of a ghrelin antagonist, and reduces methamphetamine-associated conditioned place preference. In rats, ML314 blocks methamphetamine self-administration. ML314 acts as an allosteric enhancer of endogenous neurotensin, unmasking stoichiometric numbers of hidden NTR1 binding sites in transfected-cell membranes or mouse striatal membranes, while additionally supporting NTR1 endocytosis in cells in the absence of NT peptide. These results indicate ML314 is a viable, preclinical lead for methamphetamine abuse treatment and support an allosteric model of G protein-coupled receptor signaling.

Design, synthesis, and pharmacological evaluation of JDTic analogs to examine the significance of replacement of the 3-hydroxyphenyl group with pyridine or thiophene bioisosteres

The potent and selective KOR antagonist JDTic was derived from the N-substituted trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidine class of pure opioid antagonists. In previous studies we reported that compounds that did not have a hydroxyl on the 3-hydroxyphenyl group and did not have methyl groups at the 3- and 4-position of the piperidine ring were still potent and selective KOR antagonists. In this study we report JDTic analogs 2, 3a-b, 4a-b, and 5, where the 3-hydroxyphenyl ring has been replaced by a 2-, 3-, or 4-pyridyl or 3-thienyl group and do not have the 3-methyl or 3,4-dimethyl groups, remain potent and selective KOR antagonists. Of these, (3R)-7-hydroxy-N-(1S)-2-methyl-[4-methyl-4-pyridine-3-yl-carboxamide (3b) had the best overall binding potency and selectivity in a [(35)S]GTPγS functional assay, with a Ke=0.18nM at the KOR and 273- and 16,700-fold selectivity for the KOR relative to the MOR and DOR, respectively. Calculated physiochemical properties for 3b suggest that it will cross the blood-brain barrier.

Discovery of a novel small molecule agonist scaffold for the APJ receptor

The apelinergic system includes a series of endogenous peptides apelin, ELABELA/TODDLER and their 7-transmembrane G-protein coupled apelin receptor (APJ, AGTRL-1, APLNR). The APJ receptor is an attractive therapeutic target because of its involvement in cardiovascular diseases and potentially other disorders including liver fibrosis, obesity, diabetes, and neuroprotection. To date, pharmacological characterization of the APJ receptor has been limited due to the lack of small molecule functional agonists or antagonists. Through focused screening we identified a drug-like small molecule agonist hit 1 with a functional EC50 value of 21.5±5μM and binding affinity (Ki) of 5.2±0.5μM. Initial structure-activity studies afforded compound 22 having a 27-fold enhancement in potency and the first sub-micromolar full agonist with an EC50 value of 800±0.1nM and Ki of 1.3±0.3μM. Preliminary SAR, synthetic methodology, and in vitro pharmacological characterization indicate this scaffold will serve as a favorable starting point for further refinement of APJ potency and selectivity.

Design, synthesis, and pharmacological evaluation of JDTic analogs to examine the significance of the 3- and 4-methyl substituents

The design and discovery of JDTic as a potent and selective kappa opioid receptor antagonist used the N-substituted trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidine pharmacophore as the lead structure. In order to determine if the 3-methyl or 4-methyl groups were necessary in JDTic and JDTic analogs for antagonistic activity, compounds 4a-c, and 4d-f which have either the 3-methyl or both the 3- and 4-methyl groups removed, respectively, from JDTic and analogs were synthesized and evaluated for their in vitro opioid receptor antagonist activities using a [(35)S]GTPγS binding assay. Other ADME properties were also assessed for selected compounds. These studies demonstrated that neither the 3-methyl or 3,4-dimethyl groups present in JDTic and analogs are required to produce potent and selective κ opioid receptor antagonists.

The amide linker in nonpeptide neurotensin receptor ligands plays a key role in calcium signaling at the neurotensin receptor type 2

Compounds acting via the GPCR neurotensin receptor type 2 (NTS2) display analgesia in relevant preclinical models. The amide bond in nonpeptide NTS1 antagonists plays a central role in receptor recognition and molecular conformation. Using NTS2 FLIPR and binding assays, we found that it is also a key molecular structure for binding and calcium mobilization at NTS2. We found that reversed amides display a shift from agonist to antagonist activity and provided examples of the first competitive nonpeptide antagonists observed in the NTS2 FLIPR assay. These compounds will be valuable tools for determining the role of calcium signaling in vitro to NTS2 mediated analgesia.

Identification of N-[(5-{[(4-methylphenyl)sulfonyl]amino}-3-(trifluoroacetyl)-1H-indol-1-yl)acetyl]-l-leucine (NTRC-824), a neurotensin-like nonpeptide compound selective for the neurotensin receptor type 2

Compounds acting via the neurotensin receptor type 2 (NTS2) are known to be active in animal models of acute and chronic pain. To identify novel NTS2 selective analgesics, we searched for NTS2 selective nonpeptide compounds using a FLIPR assay and identified the title compound (NTRC-824, 5) that, to our knowledge, is the first nonpeptide that is selective for NTS2 versus NTS1 and behaves like the endogenous ligand neurotensin in the functional assay.

Design, synthesis, and biological evaluation of (3R)-1,2,3,4-tetrahydro-7-hydroxy-N-[(1S)-1-[[(3R,4R)-4-(3-hydroxyphenyl)-3,4-dimethyl-1-piperidinyl]methyl]-2-methylpropyl]-3-isoquinolinecarboxamide (JDTic) analogues: in vitro pharmacology and ADME profile

JDTic analogues 4–15 which have the hydroxyl groups replaced with other groups were synthesized and their in vitro efficacy at the μ, δ, and κ opioid receptors determined and compared to JDTic using [³⁵S]GTPγS assays. Compounds 4, 5, 6, 13, 14, and 15 had K_e = 0.024, 0.01, 0.039, 0.02, 0.11, and 0.041 nM compared to the K_e = 0.02 nM for JDTic at the κ receptor and were highly selective for the κ receptor relative to the μ and δ opioid receptors. Unexpectedly, replacement of the 3-hydroxyl substituent of the 4-(3-hydroxyphenyl) group of JDTic with a H, F, or Cl substituent leads to potent and selective KOR antagonists. In vitro studies to determine various ADME properties combined with calculated TPSA, clogP, and logBB values suggests that the potent and selective κ opioid receptors 4, 5, 13, and 14 deserve consideration for further development toward potential drugs for CNS disorders.

Identification of 1-({[1-(4-fluorophenyl)-5-(2-methoxyphenyl)-1H-pyrazol-3-yl]carbonyl}amino)cyclohexane carboxylic acid as a selective nonpeptide neurotensin receptor type 2 compound

Compounds active at neurotensin receptors (NTS1 and NTS2) exert analgesic effects on different types of nociceptive modalities, including thermal, mechanical, and chemical stimuli. The NTS2 preferring peptide JMV-431 (2) and the NTS2 selective nonpeptide compound levocabastine (6) have been shown to be effective in relieving the pain associated with peripheral neuropathies. With the aim of identifying novel nonpeptide compounds selective for NTS2, we examined analogues of SR48692 (5a) using a FLIPR calcium assay in CHO cells stably expressing rat NTS2. This led to the discovery of the NTS2 selective nonpeptide compound 1-({[1-(4-fluorophenyl)-5-(2-methoxyphenyl)-1H-pyrazol-3-yl]carbonyl}amino)cyclohexane carboxylic acid (NTRC-739, 7b) starting from the nonselective compound 5a.

Effect of the 3- and 4-methyl groups on the opioid receptor properties of N-substituted trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidines

N-substituted trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidines (2a,b) are opioid receptor antagonists where the antagonist properties are not due to the type of N-substituent. In order to gain a better understanding of the contribution that the 3- and 4-methyl groups make to the pure antagonist properties of 2a,b, we synthesized analogues of 2a,b that lacked the 4-methyl (5a,b), 3-methyl (6a,b), and both the 3- and 4-methyl group (7a,b) and compared their opioid receptor properties. We found that (1) all N-methyl and N-phenylpropyl substituted compounds were nonselective opioid antagonists (2) all N-phenylpropyl analogues were more potent than their N-methyl counterparts, and (3) compounds 2a,b which have both a 3- and 4-methyl substituent, were more potent antagonists than analogues 5a,b, 6a,b, and 7a,b. We also found that the removal of 3-methyl substituent of N-methyl and N-phenylpropyl 3-methyl-4-(3-hydroxyphenyl)piperazines (8a,b) gives (4a,b), which are opioid antagonists.

Imidazole-derived agonists for the neurotensin 1 receptor

A scaffold-hop program seeking full agonists of the neurotensin-1 (NTR1) receptor identified the probe molecule ML301 (1) and associated analogs, including its naphthyl analog (14) which exhibited similar properties. Compound 1 showed full agonist behavior (79-93%) with an EC50 of 2.0-4.1μM against NTR1. Compound 1 also showed good activity in a Ca mobilization FLIPR assay (93% efficacy at 298nM), consistent with it functioning via the Gq coupled pathway, and good selectivity relative to NTR2 and GPR35. In further profiling, 1 showed low potential for promiscuity and good overall pharmacological data. This report describes the discovery, synthesis, and SAR of 1 and associated analogs. Initial in vitro pharmacologic characterization is also presented.

4β-Methyl-5-(3-hydroxyphenyl)morphan opioid agonist and partial agonist derived from a 4β-methyl-5-(3-hydroxyphenyl)morphan pure antagonist

In previous studies we reported that addition of 7α-acylamino groups to N-phenylpropyl-4β-methyl-5-(3-hydroxyphenyl)morphan (4) led to compounds that were pure opioid receptor antagonists. In contrast to these findings we report in this study that addition of a 7α-amino (5a), 7α-alkylamino (5b-e), or 7α-dialkylamino (5f-h) group to 4 leads to opioid receptor ligands with varying degrees of agonist/antagonist activity. The 7α-amino and 7α-methylamino analogues were full agonists at the μ and δ receptors and antagonists at the κ receptor. The 7α-cyclopropylmethylamino analogue 5h was a full agonist at the μ receptor with weaker agonist activity at the δ and κ receptors. Whereas the addition of a 7α-acylamino group to the pure nonselective opioid receptor antagonist N-phenylpropyl-4β-methyl-5-(3-hydroxyphenyl)morphan (4) led to κ selective pure opioid receptor antagonist, the addition of a 7α-amino, 7α-alkylamino, or 7α-dialkylamino group to 4 leads to opioid ligands that are largely μ or δ agonist with mixed agonist/antagonist properties.

Discovery of ML314, a Brain Penetrant Non-Peptidic β-Arrestin Biased Agonist of the Neurotensin NTR1 Receptor

The neurotensin 1 receptor (NTR1) is an important therapeutic target for a range of disease states including addiction. A high throughput screening campaign, followed by medicinal chemistry optimization, led to the discovery of a non-peptidic β-arrestin biased agonist for NTR1. The lead compound, 2-cyclopropyl-6,7-dimethoxy-4-(4-(2-methoxyphenyl)- piperazin-1-yl)quinazoline, 32 (ML314), exhibits full agonist behavior against NTR1 (EC₅₀ = 2.0 μM) in the primary assay and selectivity against NTR2. The effect of 32 is blocked by the NTR1 antagonist SR142948A in a dose dependent manner. Unlike peptide based NTR1 agonists, compound 32 has no significant response in a Ca²⁺ mobilization assay and is thus a biased agonist that activates the β-arrestin pathway rather than the traditional G _q coupled pathway. This bias has distinct biochemical and functional consequences that may lead to physiological advantages. Compound 32 displays good brain penetration in rodents, and studies examining its in vivo properties are underway.

Discovery of N-{4-[(3-hydroxyphenyl)-3-methylpiperazin-1-yl]methyl-2-methylpropyl}-4-phenoxybenzamide analogues as selective kappa opioid receptor antagonists

There is continuing interest in the discovery and development of new κ opioid receptor antagonists. We recently reported that N-substituted 3-methyl-4-(3-hydroxyphenyl)piperazines were a new class of opioid receptor antagonists. In this study, we report the syntheses of two piperazine JDTic-like analogues. Evaluation of the two compounds in an in vitro [(35)S]GTPγS binding assay showed that neither compound showed the high potency and κ opioid receptor selectivity of JDTic. A library of compounds using the core scaffold 21 was synthesized and tested for their ability to inhibit [(35)S]GTPγS binding stimulated by the selective κ opioid agonist U69,593. These studies led to N-[(1S)-1-{[(3S)-4-(3-hydroxyphenyl)-3-methylpiperazin-1-yl]methyl}-2-methylpropyl]-4-phenoxybenzamide (11a), a compound that showed good κ opioid receptor antagonist properties. An SAR study based on 11a provided 28 novel analogues. Evaluation of these 28 compounds in the [(35)S]GTPγS binding assay showed that several of the analogues were potent and selective κ opioid receptor antagonists.

The development and implementation of quality assurance programs to support nutritional measurements

The National Institute of Standards and Technology administers quality assurance programs devoted to improving measurements of nutrients and related metabolites in foods, dietary supplements, and serum and plasma samples. These programs have been developed in collaboration with the National Institutes of Health to assist measurement communities in their efforts to achieve accurate results that are comparable among different laboratories and over time. Targeted analytes include micronutrients, botanical markers, nutritional elements, contaminants, fatty acids, and vitamin D metabolites.

Low social status impairs hypoxia tolerance in rainbow trout (Oncorhynchus mykiss)

In the present study, chronic behavioural stress resulting from low social status affected the physiological responses of rainbow trout (Oncorhynchus mykiss) to a subsequent acute stressor, exposure to hypoxia. Rainbow trout were confined in fork-length matched pairs for 48-72 h, and social rank was assigned based on behaviour. Dominant and subordinate fish were then exposed individually to graded hypoxia (final water PO(2), PwO(2) = 40 Torr). Catecholamine mobilization profiles differed between dominant and subordinate fish. Whereas dominant fish exhibited generally low circulating catecholamine levels until a distinct threshold for release was reached (PwO(2) = 51.5 Torr corresponding to arterial PO(2), PaO(2) = 24.1 Torr), plasma catecholamine concentrations in subordinate fish were more variable and identification of a distinct threshold for release was problematic. Among fish that mobilized catecholamines (i.e. circulating catecholamines rose above the 95% confidence interval around the baseline value), however, the circulating levels achieved in subordinate fish were significantly higher (459.9 ± 142.2 nmol L(-1), mean ± SEM, N = 12) than those in dominant fish (130.9 ± 37.9 nmol L(-1), N = 12). The differences in catecholamine mobilization occurred despite similar P(50) values in dominant (22.0 ± 1.5 Torr, N = 6) and subordinate (22.1 ± 2.2 Torr, N = 8) fish, and higher PaO(2) values in subordinate fish under severely hypoxic conditions (i.e. PwO(2) < 60 Torr). The higher PaO(2) values of subordinate fish likely reflected the greater ventilatory rates and amplitudes exhibited by these fish during severe hypoxia. At the most severe level of hypoxia, subordinate fish were unable to defend arterial blood O(2) content, which fell to approximately half (0.60 ± 0.13 mL O(2) g(-1) haemoglobin, N = 9) that of dominant fish (1.08 ± 0.09 mL O(2) g(-1) haemoglobin, N = 9). Collectively, these data indicate that chronic social stress impacts the ability of trout to respond to the additional, acute stress of hypoxia.

Certification of vitamins and carotenoids in SRM 3280 multivitamin/multielement tablets

A new multivitamin/multielement dietary supplement Standard Reference Material (SRM) has been issued by the National Institute of Standards and Technology (NIST), with certified and reference concentration values for 13 vitamins, 24 elements, and 2 carotenoids. The constituents have been measured by multiple analytical methods with data contributed by NIST and by collaborating laboratories. This effort included the first use of isotope dilution mass spectrometry for value assignment of both fat-soluble vitamins (FSVs) and water-soluble vitamins (WSVs). Excellent agreement was obtained among the methods, with relative expanded uncertainties for the certified concentration values typically ranging from <2% to 15% for vitamins.

1-Substituted 4-(3-Hydroxyphenyl)piperazines Are Pure Opioid Receptor Antagonists

This report describes the discovery that 1-substituted 4-(3-hydroxyphenyl)piperazines are pure opioid receptor antagonists. Compounds in this new series include N-phenylpropyl (3S)-3-methyl-4-(3-hydroxyphenyl)piperazine and (3R)-3-methyl-4-(3-hydroxyphenyl)piperazine, both of which diaplay low nanomolar potencies at μ, δ, and κ receptors and pure antagonist properties in a [(35)S]GTPγS assay.

Discovery and biological evaluation of potent, selective, orally bioavailable, pyrazine-based blockers of the Na(v)1.8 sodium channel with efficacy in a model of neuropathic pain

Na(v)1.8 (also known as PN3) is a tetrodotoxin-resistant (TTx-r) voltage-gated sodium channel (VGSC) that is highly expressed on small diameter sensory neurons. It has been implicated in the pathophysiology of inflammatory and neuropathic pain, and we envisioned that selective blockade of Na(v)1.8 would be analgesic, while reducing adverse events typically associated with non-selective VGSC blocking therapeutic agents. Herein, we describe the preparation and characterization of a series of 6-aryl-2-pyrazinecarboxamides, which are potent blockers of the human Na(v)1.8 channel and also block TTx-r sodium currents in rat dorsal root ganglia (DRG) neurons. Selected derivatives display selectivity versus human Na(v)1.2. We further demonstrate that an example from this series is orally bioavailable and produces antinociceptive activity in vivo in a rodent model of neuropathic pain following oral administration.

Analogues of (3R)-7-hydroxy-N-[(1S)-1-{[(3R,4R)-4-(3-hydroxyphenyl)-3,4-dimethyl-1-piperidinyl]methyl}-2-methylpropyl)-1,2,3,4-tetrahydro-3-isoquinolinecarboxamide (JDTic). Synthesis and in vitro and in vivo opioid receptor antagonist activity

The synthesis of compounds 6, 7a,b, 8a,b, 9a,b, and 10a,b where the amino -NH- group of JDTic (3) was replaced with an aromatic horizontal lineCH-, CH(2), O, S, or SO group was accomplished and used to further characterize the SAR of the compound 3 class of kappa opioid receptor antagonists. All of the compounds showed subnanomolar to low nanomolar K(e) values at the kappa opioid receptor. The most potent compound was 7a, where the amino -NH- group of 3 was replaced by a methylene (-CH(2)-) group. This compound had a K(e) = 0.18 nM and was 37- and 248-fold selective for the kappa relative to the mu and delta opioid receptors, respectively. Similar to compound 3, compound 7a antagonized selective kappa agonist U50,488-induced diuresis after sc administration in rats. In contrast to 3, where kappa antagonist activity lasted for three weeks, compound 7a did not show any kappa antagonist activity after one week.

Inhibition of Photosynthesis in Some Algae by Extreme-Red Light

Photosynthesis produced by far-red light (about 700 mmicro) is reversibly inhibited in some algae by extreme-red light ( approximately 750 mmicro).

Synthesis and in vitro opioid receptor functional antagonism of methyl-substituted analogues of (3R)-7-hydroxy-N-[(1S)-1-{[(3R,4R)-4-(3-hydroxyphenyl)-3,4-dimethyl-1-piperidinyl]methyl}-2-methylpropyl]-1,2,3,4-tetrahydro-3-isoquinolinecarboxamide (JDTic)

In previous structure-activity relationship (SAR) studies, (3R)-7-hydroxy-N-[(1S)-1-{[(3R,4R)-4-(3-hydroxyphenyl)-3,4-dimethyl-1-piperidinyl]methyl}-2-methylpropyl]-1,2,3,4-tetrahydro-3-isoquinolinecarboxamide (JDTic, 3) was identified as the first potent and selective kappa-opioid receptor antagonist from the trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidine class of opioid antagonists. In the present study, we report the synthesis of analogues 8a-p of 3 and present their in vitro opioid receptor functional antagonism using a [(35)S]GTPgammaS binding assay. Compounds 8a-p are analogues of 3 containing one, two, or three methyl groups connected to the JDTic structure at five different positions. All the analogues with one and two added methyl groups with the exception of 8k had subnanomolar K(e) values at the kappa receptor. The three most potent analogues were the monomethylated (3R)-7-hydroxy-N-[(1S,2S)-1-{[(3R,4R)-4-(3-hydroxyphenyl)-3,4-dimethylpiperidine-1-yl]methyl}-2-methylbutyl]-1,2,3,4-tetrahydroisoquinoline-3-carboxamide (8a) and (3R)-7-hydroxy-N-[(1S)-1-{[(3R,4R)-4-(3-hydroxyphenyl)-3,4-dimethylpiperidin-1-yl]methyl}-(2-methylpropyl)]-3-methyl-1,2,3,4-tetrahydroisoquinoline-3-carboxamide (8e) with K(e) values of 0.03 nM at the kappa receptor and (3R)-7-hydroxy-N-[(1S)-1-{[(3R,4R)-4-(3-methoxyphenyl)-3,4-dimethylpiperidin-1-yl]methyl}-2-methylpropyl]-1,2,3,4-tetrahydroisoquinoline-3-carboxamide (8d) with K(e) = 0.037 nM at the kappa receptor. All three compounds were selective for the kappa receptor relative to the micro and delta receptors. Overall, the results from this study highlight those areas that are tolerant to substitution on 3.

Inhibition of Photosynthesis in Certain Algae by Extreme Red Light

This paper shows that in Porphyridium cruentum and in Chlorella pyrenoidosa (but apparently not in Anacystis nidulans) "extreme red" light (> 720 mmu) can inhibit photosynthesis produced by "far red" light (up to 720 mmu). From the action spectrum of this phenomenon, it appears that an unknown pigment with an absorption band around 745 mmu must be responsible for it.

The identification of nonpeptide neurotensin receptor partial agonists from the potent antagonist SR48692 using a calcium mobilization assay

In a search for nonpeptide agonists for the neurotensin receptor (NTR1), we replaced the adamantyl amino acid moiety found in the antagonist SR48692 (1a) with leucine and related alpha-alkylamino acids found in peptide agonists. When tested in a calcium mobilization assay, we found that both d- and l-leucine confer partial agonist activity to the pyrazole scaffold with the l-enantiomer (3a) providing a significantly greater response. A brief SAR survey demonstrated that the observed agonist activity was resilient to changes made to the dimethoxyaryl ring in 3a. The resulting compounds were less potent relative to 3a but showed greater agonist responses. The partial agonist activity was extinguished when the chloroquinoline ring was replaced with naphthalene. Thus, while l-leucine appears to possess a powerful agonist directing affect for the NTR1 receptor, its presence alone in the molecular architecture is not sufficient to insure agonist behavior.

Discovery of potent furan piperazine sodium channel blockers for treatment of neuropathic pain

The synthesis and pharmacological characterization of a novel furan-based class of voltage-gated sodium channel blockers is reported. Compounds were evaluated for their ability to block the tetrodotoxin-resistant sodium channel Na(v)1.8 (PN3) as well as the Na(v)1.2 and Na(v)1.5 subtypes. Benchmark compounds from this series possessed enhanced potency, oral bioavailability, and robust efficacy in a rodent model of neuropathic pain, together with improved CNS and cardiovascular safety profiles compared to the clinically used sodium channel blockers mexiletine and lamotrigine.

Synthesis and in vitro opioid receptor functional antagonism of analogues of the selective kappa opioid receptor antagonist (3R)-7-hydroxy-N-((1S)-1-{[(3R,4R)-4-(3-hydroxyphenyl)-3,4-dimethyl-1-piperidinyl]methyl}-2-methylpropyl)-1,2,3,4-tetrahydro-3-isoquinolinecarboxamide (JDTic)

In previous structure-activity relationship (SAR) studies, we identified (3 R)-7-hydroxy- N-((1 S)-1-{[(3 R,4 R)-4-(3-hydroxyphenyl)-3,4-dimethyl-1-piperidinyl]methyl}-2-methylpropyl)-1,2,3,4-tetrahydro-3-isoquinolinecarboxamide (JDTic, 1) as the first potent and selective kappa opioid receptor antagonist from the trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidine class of opioid antagonist. In the present study, we report the synthesis and in vitro opioid receptor functional antagonism of a number of analogues of 1 using a [ (35) S]GTPgammaS binding assay. The results from the studies better define the pharmacophore for this class of kappa opioid receptor antagonist and has identified new potent and selective kappa antagonist. (3 R)-7-Hydroxy- N-[(1 S,2 S)-1-{[(3 R,4 R)-4-(3-hydroxyphenyl)-3,4-dimethylpiperidin-1-yl]methyl}-2-methylbutyl]-1,2,3,4-tetrahydroisoquinoline-3-carboxamide ( 3) with a K e value of 0.03 nM at the kappa receptor and 100- and 793-fold selectivity relative to the mu and delta receptors was the most potent and selective kappa opioid receptor antagonist identified.

Discovery and biological evaluation of 5-aryl-2-furfuramides, potent and selective blockers of the Nav1.8 sodium channel with efficacy in models of neuropathic and inflammatory pain

Nav1.8 (also known as PN3) is a tetrodotoxin-resistant (TTx-r) voltage-gated sodium channel (VGSC) that is highly expressed on small diameter sensory neurons and has been implicated in the pathophysiology of inflammatory and neuropathic pain. Recent studies using an Nav1.8 antisense oligonucleotide in an animal model of chronic pain indicated that selective blockade of Nav1.8 was analgesic and could provide effective analgesia with a reduction in the adverse events associated with nonselective VGSC blocking therapeutic agents. Herein, we describe the preparation and characterization of a series of 5-substituted 2-furfuramides, which are potent, voltage-dependent blockers (IC50 < 10 nM) of the human Nav1.8 channel. Selected derivatives, such as 7 and 27, also blocked TTx-r sodium currents in rat dorsal root ganglia (DRG) neurons with comparable potency and displayed >100-fold selectivity versus human sodium (Nav1.2, Nav1.5, Nav1.7) and human ether-a-go-go (hERG) channels. Following systemic administration, compounds 7 and 27 dose-dependently reduced neuropathic and inflammatory pain in experimental rodent models.

A new synthesis of the ORL-1 antagonist 1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidinyl]-3-ethyl-1,3-dihydro-2H-benzimidazol-2-one (J-113397) and activity in a calcium mobilization assay

A new chiral synthesis of the ORL-1 antagonist 1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidinyl]-3-ethyl-1,3-dihydro-2H-benzimidazol-2-one (2, J-113397) was developed. J-113397 has a K(e)=0.85nM in an ORL-1 calcium mobilization assay and is 89-, 887-, and 227-fold selective for the ORL-1 receptor relative to the mu, delta, and kappa opioid receptors.

Anxiolytic-Like Effects of κ-Opioid Receptor Antagonists in Models of Unlearned and Learned Fear in Rats

Endogenous opioid systems regulate neurobiological responses to threatening stimuli. Stimulation of kappa-opioid receptors (KORs) produces analgesia but induces prodepressive-like effects in a variety of animal models. In contrast, KOR antagonists have antidepressant-like effects. KORs and their endogenous ligand dynorphin are expressed throughout brain areas involved in fear and anxiety, including the extended amygdala. Here, we examined whether KOR antagonists would affect unlearned fear (anxiety) in the elevated plus maze (EPM) and open field (OF) paradigms and learned fear in the fear-potentiated startle (FPS) paradigm. These studies were designed to accommodate the slow onset (approximately 24 h) and extended time course (>3 weeks) of the prototypical KOR antagonists nor-binaltorphimine hydrochloride (norBNI) and JDTic [(3R)-7-hydroxy-N-[(1S)-1-[[(3R, 4R)-4-(3-hydroxyphenyl)-3,4-dimethyl-1-piperidinyl]methyl]-2-methylpropyl]-1,2,3,4-tetrahydro-3-isoquinoline-carboxamide hydrochloride]. Rats received an i.p. injection of norBNI (3.0-30 mg/kg) or JDTic (1.0-10 mg/kg) 48 h before EPM testing. One day later, they were tested in the OF, and 5 and 7 days later, they were trained and tested in the FPS paradigm. Both KOR antagonists dose-dependently increased open arm exploration in the EPM without affecting OF behavior. They also decreased conditioned fear in the FPS paradigm. The anxiolytic-like effects of KOR antagonists were qualitatively similar to those of the benzodiazepine chlordiazepoxide in the EPM. The selective serotonin reuptake inhibitor fluoxetine had no effect in the EPM and anxiogenic-like effects in the OF. Our results indicate that KOR antagonists produce a unique combination of antidepressant- and anxiolytic-like effects and suggest that this class of drugs may be particularly effective for the treatment of comorbid depressive and anxiety disorders.

Highly Potent and Selective Phenylmorphan-Based Inverse Agonists of the Opioid δ Receptor

We recently reported the discovery of (+)-5-(3-hydroxyphenyl)-4-methyl-2-(3-phenylpropyl)-2-azabicyclo[3.3.1]non-7-yl-(1-phenyl-1-cyclopentane)carboxamide [(+)-KF4, (+)-5] as a novel chemotype possessing potent antagonist activity at the delta opioid receptor. Additional SAR studies involving changes to both the 2-amino and 7-amido N-substituents using this same (+)-morphan scaffold have revealed compounds with improved potency and selectivity for the delta opioid receptor. The highly potent and selective 2,2-dimethylphenylacetamide analogue (+)-N-[(1S,4R,5R,7S)-5-(3-hydroxyphenyl)-4-methyl-2-(3-phenylpropyl)-2-azabicyclo[3.3.1]non-7-yl]-2-methyl-2-phenylpropanamide (13d, delmorphan-A) showed picomolar inhibitory potency (Ke = 0.1 nM) in the [35S]GTPgammaS functional assay with delta opioid receptor selectivity ratios of 103- and 132-fold versus the mu and kappa opioid receptors, respectively. The compounds showed no agonist activity at any of the three opioid receptors; however, measurements of delta inverse agonist activity within this series illustrated a broad range of negative efficacy and IC50 values 650-fold more potent than the prototypical delta opioid receptor inverse agonist ICI 174,864 (22).

Effects of ageing on the biomechanical properties of rat articular cartilage

Previous studies have demonstrated that male Sprague Dawley (SD) rats experience age-related bone loss with the same characteristics as that in ageing men. As articular cartilage, like bone, is a critical component of the health and function of the musculoskeletal system, the authors hypothesized that articular cartilage in the untreated male SD rats could be a suitable model for studying the age-related deterioration of articular cartilage in men. To test this hypothesis, male SD rats were killed at between 6 and 27 months. The right femur of each rat was removed. The effects of ageing on the structural integrity of the distal femoral articular cartilage were studied by biomechanical testing with a creep indentation apparatus. The aggregate modulus, Poisson's ratio, permeability, thickness, and percentage recovery of articular cartilage were determined using finite element/non-linear optimization modelling. No significant differences were observed in these biomechanical properties of the distal femoral articular cartilage as a function of age. Therefore, untreated male SD rats appear to be unsuitable for studying the age-related changes of articular cartilage as they occur in men. However, and more intriguingly, it is also possible that ageing does not affect the biomechanical properties of articular cartilage in the absence of cartilage pathology.

N-substituted 4beta-methyl-5-(3-hydroxyphenyl)-7alpha-amidomorphans are potent, selective kappa opioid receptor antagonists

In a previous study, we identified (-)-N-[(1R,4S,5S,7R)-5-(3-hydroxyphenyl)-4-methyl-2-(3-phenylpropyl)-2-azabicyclo[3.3.1]non-7-yl]-3-(1-piperidinyl)propanamide (5a, KAA-1) as the first potent and selective kappa opioid receptor antagonist from the 5-(3-hydroxyphenyl)morphan class of opioids. In this study we report an improved synthesis of this class of compounds. The new synthetic method was used to prepare analogues 5b-r where the morphan N-substituent and 7alpha-amido group were varied. Most of the analogues showed sub-nanomolar potency for the kappa opioid receptor and were highly selective relative to the mu and delta opioid receptors. (-)-3-(3,4-Dihydroisoquinolin-2(1H)-yl)-N-{(1R,4S,5S,7R)-5-(3-hydroxyphenyl)-4-methyl-2-[2-(2-methylphenyl)ethyl]-2-azabicyclo[3.3.1]non-7-yl}propanamide (5n, MTHQ) is at least as potent and selective as nor-BNI as a kappa opioid receptor antagonist in the [35S]GTP-gamma-S in vitro functional test.

N-substituted cis-4a-(3-hydroxyphenyl)-8a-methyloctahydroisoquinolines are opioid receptor pure antagonists

N-Substituted cis-4a-(3-hydroxyphenyl)-8a-methyloctahydroisoquinolines (6a-g) were designed and synthesized as conformationally constrained analogues of the trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidine (4) class of opioid receptor pure antagonists. The methyloctahydroisoquinolines 6a-g can exist in conformations where the 3-hydroxyphenyl substituent is either axial or equatorial, similar to the (3-hydroxyphenyl)piperidines 4. The 3-hydroxyphenyl equatorial conformation is responsible for the antagonist activity observed in the (3-hydroxyphenyl)piperidine antagonists. Single-crystal X-ray analysis of 6a shows that the 3-hydroxyphenyl equatorial conformation is favored in the solid state. Molecular modeling studies also suggest that the equatorial conformation has lower potential energy relative to that of the axial conformation. Evaluation of 6a-g in the [(35)S]GTP-gamma-S in vitro functional assay showed that they were opioid receptor pure antagonists. N-[4a-(3-Hydroxyphenyl)-8a-methyl-2-(3-phenylpropyl)octahydroisoquinoline-6-yl]-3-(piperidin-1-yl)propionamide (6d) with a K(e) of 0.27 nM at the kappa opioid receptor with 154- and 46-fold selectivity relative to those of the micro and delta receptors, respectively, possessed the best combination of kappa potency and selectivity.

The impact of social status on the erythrocyte beta-adrenergic response in rainbow trout, Oncorhynchus mykiss

The objective of the present investigation was to determine whether chronic increases in circulating cortisol concentrations, resulting from the occupation of subordinate status in rainbow trout social hierarchies, resulted in an enhancement of the erythrocyte adrenergic response. Rainbow trout (Oncorhynchus mykiss) were confined in fork length matched pairs for 6 h, 18 h, 48 h or 5-7 days, and social status was assigned through observations of behaviour. Erythrocyte adrenergic responsiveness, determined in vitro as changes in water content following incubation with the beta-adrenoreceptor agonist isoproterenol, was significantly greater in subordinate than dominant fish at 48 h of social interactions but not after 5-7 days, nor when assessed as changes in extracellular pH (pHe). However, the activity of the Na+/H+ exchanger (beta-NHE), assessed in vitro as the pHe change following incubation with the permeable cyclic AMP analogue 8-bromo-cyclic AMP, was significantly lower in subordinate fish. The number of erythrocyte membrane-bound adrenergic receptors (Bmax) was significantly higher in subordinate than dominant fish at 48 h, but had decreased by 5-7 days to a value that was not significantly different from that for dominant fish. The apparent dissociation constant (KD) of these receptors was not significantly impacted by either social status or interaction time. Finally, the relative expressions of beta-3b adrenergic receptor (AR) and beta-NHE mRNA were determined using real-time PCR and were found to be minimally affected by social rank. Relative to a control group, beta-3b AR mRNA was significantly up-regulated in both dominant and subordinate trout at all time periods, whereas the expression of beta-NHE was in general significantly down-regulated. Unlike the situation in rainbow trout treated with exogenous cortisol, elevations in circulating cortisol resulting from low social status did not "pre-adapt" the erythrocyte adrenergic response, but rather may have served to offset the potentially adverse effects elicited by plasma catecholamines, which were elevated during social hierarchy formation.

Synthesis of long-chain amide analogs of the cannabinoid CB1 receptor antagonist N-(piperidinyl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (SR141716) with unique binding selectivities and pharmacological activities

An extended series of alkyl carboxamide analogs of N-(piperidinyl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl- 1H-pyrazole-3-carboxamide (SR141716; 5) was synthesized. Each compound was tested for its ability to displace the prototypical cannabinoid ligands ([3H]CP-55,940, [3H]2; [3H]SR141716, [3H]5; and [3H]WIN55212-2, [3H]3), and selected compounds were further characterized by determining their ability to affect guanosine 5'-triphosphate (GTP)-gamma-[35S] binding and their effects in the mouse vas deferens assay. This systematic evaluation has resulted in the discovery of novel compounds with unique binding properties at the central cannabinoid receptor (CB1) and distinctive pharmacological activities in CB1 receptor tissue preparations. Specifically, compounds with nanomolar affinity which are able to fully displace [3H]5 and [3H]2, but unable to displace [3H]3 at similar concentrations, have been synthesized. This selectivity in ligand displacement is unprecedented, in that previously, compounds in every structural class of cannabinoid ligands had always been shown to displace each of these radioligands in a competitive fashion. Furthermore, the selectivity of these compounds appears to impart unique pharmacological properties when tested in a mouse vas deferens assay for CB1 receptor antagonism.

Pharmacological properties of JDTic: a novel kappa-opioid receptor antagonist

Biological studies were conducted on (3R)-7-Hydroxy-N-[(1S)-1-[[(3R,4R)-4-(3-hydroxyphenyl)-3,4-dimethyl-1-piperidinyl]methyl]-2-methylpropyl]-1,2,3,4-tetrahydro-3-isoquinoline-carboxamide (JDTic), the first potent kappa-selective opioid receptor antagonist not derived from an opiate class of compounds. In the mouse tail-flick test, JDTic, administered subcutaneously (s.c.), blocked anticociceptive activity for up to 2 weeks. When JDTic was administered either s.c. or p.o. 24 h before the selective KOP (kappa)-opioid receptor agonist, enadoline, AD(50s) of 4.1 and 27.3, respectively, were obtained. A time-course study of JDTic versus enadoline indicated significant antagonist p.o. activity up to 28 days. In contrast, JDTic, s.c., failed to antagonize the analgesic effects of the selective MOP mu-opioid receptor agonist, sufentanil. In the squirrel monkey shock titration antinociception test, JDTic given intramuscularly (i.m.) shifted the trans-3,4-dichloro-N-methyl-N-(2-[1-pyrrolidinyl] cyclohexyl) benzeneacetamide (U50,488) dose-effect curve to the right. In the U50,488-induced diuresis rat test, JDTic, s.c., suppressed diuretic activity with a greater potency than that of nor-binaltorphimine (nor-BNI). Thus, JDTic is a potent long- and orally acting selective kappa-opioid antagonist.

Addison's disease presenting in four adolescents with type 1 diabetes

Primary adrenocortical insufficiency (Addison's disease) is a potentially fatal condition that often develops insidiously and can be easily overlooked. Although rare in the general population, it is more common in patients with type 1 diabetes mellitus (T1DM). The combination of Addison's disease with T1DM and/or autoimmune thyroid disease is known as autoimmune polyendocrine syndrome type-2 (APS-2). T1DM commonly precedes the development of adrenocortical insufficiency in most patients with APS-2. We, in this study, present four cases of Addison's disease developing in adolescents with pre-existing T1DM. Risk factors for Addison's disease in this population include a history of other organ-specific autoimmunity, particularly thyroid, and a positive family history. In addition to the 'classic' Addisonian features, the development of unexplained recurrent hypoglycemia, reduction in total insulin requirement, improvement in glycemic control, or abnormal pigmentation should arouse suspicion of adrenocortical insufficiency. Adrenal antibodies have been proposed as a screening tool for Addison's disease in the T1DM population, but doubts remain about their specificity and sensitivity. The addition of specific HLA DRB1 subtyping has been proposed to improve predictive value.

Correlation of cartilage stiffness to thickness and level of degeneration using a handheld indentation probe

The in vivo assessment of the quality of cartilage is a critical tool to determine how to clinically treat damaged cartilage. Utilizing nondestructive indentation, a hand-held instrument (ACTAEON Probe) was used to rapidly measure the stiffness of articular cartilage, which can then be correlated to cartilage condition. An integrated series of tests were performed to determine whether the Probe is sensitive enough to detect early degenerative changes in articular cartilage and to examine if it is dependent on the thickness of the cartilage being tested. Results demonstrated that there is no effect of thickness on the Probe measurements for clinically relevant human cartilage samples, that the Probe is sensitive enough to detect different levels of cartilage degeneration, and that Probe data correlate well with traditional creep indentation testing. This study demonstrates the utility of the Probe for detecting degenerative changes in animal and human joints.

Importance of phenolic address groups in opioid kappa receptor selective antagonists

In vitro characterization and comparison of JDTic, its dehydroxy analogue and nor-BNI, and its dehydroxy analogue demonstrates that the N-substituted 3,4-dimethyl-(3-hydroxyphenyl)piperidine-derived antagonist, JDTic, relies more heavily on its phenol address group for affinity and antagonist activity relative to the corresponding naltrexone derived antagonists, nor-BNI. The structural flexibility of the former class of compound relative to the latter is postulated to underlie the difference.