Discovery of VU2957 (Valiglurax): An mGlu4 Positive Allosteric Modulator Evaluated as a Preclinical Candidate for the Treatment of Parkinson's Disease

Herein, we report the discovery of a novel potent, selective, CNS penetrant, and orally bioavailable mGlu₄ PAM, VU0652957 (VU2957, Valiglurax). VU2957 possessed attractive in vitro and in vivo pharmacological and DMPK properties across species. To advance toward the clinic, a spray-dried dispersion (SDD) formulation of VU2957 was developed to support IND-enabling toxicology studies. Based on its overall profile, VU2957 was evaluated as a preclinical development candidate for the treatment of Parkinson's disease.

Discovery of N-(benzo[1,2,3]triazol-1-yl)-N-(benzyl)acetamido)phenyl) carboxamides as severe acute respiratory syndrome coronavirus (SARS-CoV) 3CLpro inhibitors: identification of ML300 and noncovalent nanomolar inhibitors with an induced-fit binding

Herein we report the discovery and SAR of a novel series of SARS-CoV 3CLpro inhibitors identified through the NIH Molecular Libraries Probe Production Centers Network (MLPCN). In addition to ML188, ML300 represents the second probe declared for 3CLpro from this collaborative effort. The X-ray structure of SARS-CoV 3CLpro bound with a ML300 analog highlights a unique induced-fit reorganization of the S2-S4 binding pockets leading to the first sub-micromolar noncovalent 3CLpro inhibitors retaining a single amide bond.

Exploration of allosteric agonism structure-activity relationships within an acetylene series of metabotropic glutamate receptor 5 (mGlu5) positive allosteric modulators (PAMs): discovery of 5-((3-fluorophenyl)ethynyl)-N-(3-methyloxetan-3-yl)picolinamide (ML254)

Positive allosteric modulators (PAMs) of metabotropic glutamate receptor 5 (mGlu5) represent a promising therapeutic strategy for the treatment of schizophrenia. Both allosteric agonism and high glutamate fold-shift have been implicated in the neurotoxic profile of some mGlu5 PAMs; however, these hypotheses remain to be adequately addressed. To develop tool compounds to probe these hypotheses, the structure-activity relationship of allosteric agonism was examined within an acetylenic series of mGlu5 PAMs exhibiting allosteric agonism in addition to positive allosteric modulation (ago-PAMs). PAM 38t, a low glutamate fold-shift allosteric ligand (maximum fold-shift ~ 3.0), was selected as a potent PAM with no agonism in the in vitro system used for compound characterization and in two native electrophysiological systems using rat hippocampal slices. PAM 38t (ML254) will be useful to probe the relative contribution of cooperativity and allosteric agonism to the adverse effect liability and neurotoxicity associated with this class of mGlu5 PAMs.

Patterns of rehabilitation utilization after hip fracture in acute hospitals and skilled nursing facilities

BACKGROUND

Hospitalized hip fracture patients may receive physical therapy (PT) in acute and/or postacute settings. Patterns of PT use may vary by patient, clinical, and hospital characteristics. These patterns can be analyzed if the acute and postacute stays are linked.

OBJECTIVES

We classified the following patterns of PT use: acute PT only, skilled nursing facility (SNF) PT only, acute and SNF PT, and no PT. For each pattern, we compared (1) characteristics of hip fracture patients, (2) length of stay (LOS), and (3) discharge outcomes.

SUBJECTS

The study included 187,990 hospitalized hip fracture patients derived from Medicare administrative data.

MEASURES

Dependent variables were PT use patterns, acute hospital and SNF LOS, total episode days of care, and discharge destination. Independent variables were demographic, clinical, and facility characteristics. PT use patterns were also used as independent variables in the LOS and discharge destination models.

RESULTS

Patterns of PT use were influenced by demographic and clinical characteristics such as age, race, and surgery type. Similarly, different LOS measures and discharge destinations varied by the PT use patterns. Patients receiving acute PT had longer acute LOSs; however, those patients who were subsequently transferred to SNFs had shorter SNF LOSs and total episode days of care. Patients utilizing PT were more likely to be discharged to home after the acute or SNF stay.

CONCLUSIONS

Disparities in PT use exist for subgroups of patients such as the elderly and blacks. Providers should determine the most appropriate setting for initiation of PT to achieve better discharge outcomes with efficient use of resources.

Postcholecystectomy pain syndrome: pathophysiology of abdominal pain in sphincter of Oddi type III

BACKGROUND & AIMS

Persistent abdominal pain occurs in many patients after cholecystectomy, some of whom are described as having sphincter of Oddi dysfunction (SOD). Pain in SOD type III is thought to be of biliary origin with little objective data, and treatment is often unsatisfactory. Chronic abdominal pain without a biological disease marker is similar to irritable bowel syndrome, in which many patients exhibit visceral hyperalgesia. This study tested the hypothesis that duodenal-specific visceral afferent sensitivity exists in patients with SOD type III.

METHODS

Eleven patients with chronic abdominal pain after cholecystectomy and 10 controls underwent duodenal and rectal barostat studies to evaluate visceral pain perception measured with a visual analog scale. All subjects underwent psychological testing.

RESULTS

Patients with SOD type III exhibited duodenal but not rectal hyperalgesia compared with controls. There were no differences in duodenal compliance between the groups. Duodenal distention reproduced symptoms in all but 1 patient. Patients showed high levels of somatization, depression, obsessive-compulsive behavior, and anxiety.

CONCLUSIONS

Patients with SOD type III exhibited duodenal-specific visceral hyperalgesia, and duodenal distention reproduced symptoms in all but 1 patient. Abdominal pain in these patients may not originate exclusively from the biliary tree.

Visceral algesia in irritable bowel syndrome, fibromyalgia, and sphincter of oddi dysfunction, type III

Visceral hyperalgesia has been demonstrated in patients with irritable bowel syndrome who are seen in tertiary care centers. It has been hypothesized that visceral hyperalgesia may be related to psychological distress associated with health care seeking behavior in these patients. Patients with fibromyalgia and sphincter of Oddi dysfunction, type III, share many demographic and psychosocial characteristics with patients with irritable bowel syndrome and provide an opportunity to test the hypothesis that rectal hyperalgesia is unique to IBS. Fifteen patients with IBS, 10 patients with fibromyalgia, 10 with sphincter of Oddi dysfunction, type III, and 12 controls underwent evaluation of rectal pain perception in response to phasic distensions and psychological testing with a self-report instrument. Patients with irritable bowel syndrome demonstrated significantly lower rectal pain thresholds and increased levels of psychologic distress compared to controls. Although sphincter of Oddi dysfunction patients also exhibited increased psychologic distress, rectal pain perception was similar to controls. Patients with fibromyalgia exhibited rectal algesia that was not significantly different from either controls or IBS. In conclusion, rectal hyperalgesia is not a function of chronic functional pain, health care seeking behavior, or psychological distress. However, it may not be specific for IBS.

Intravenous corticotrophin vs. hydrocortisone in the treatment of hospitalized patients with Crohn's disease: a randomized double-blind study and follow-up

Adrenocorticotrophic hormone (ACTH) and corticosteroids have no maintenance values for inflammatory bowel disease but serve to reduce the severity of disease. The effectiveness of intravenous corticotrophin versus hydrocortisone in ulcerative colitis has been determined including whether previous steroid therapy influenced the better response to one rather than the other, but no such studies have ever been done in Crohn's disease. Eighty-eight patients hospitalized with moderate-to-severe Crohn's disease (Present-Korelitz [P-K] Index -3 to -2 and the International Organisation for the Study of Inflammatory Bowel Disease-Crohn's & Colitis Foundation of America [IOIBD-CCFA] Index, mean 14, range 5-23) were treated in a prospective, randomized, double-blind clinical trial to receive either continuous intravenous infusion of 120 U/day of ACTH (44 patients) or hydrocortisone 300 mg/day (44 patients). Patients were also subdivided into those who received oral steroids during the 30 days prior to intravenous therapy and those who had not. Response was followed on a daily basis and tabulated at 3, 5, and 10 days. Patients were followed from 1-3 years to determine the later status. After 10 days of intravenous therapy 36 of 44 patients (82%) who received ACTH and 41 of 44 patients (93%) who received hydrocortisone fully responded (P-K index +3 and IOIBD-CCFA Index mean of 3). At the end of the study, response to intravenous ACTH and hydrocortisone was not statistically different whether or not patients received oral steroids during the 30 days prior to admission, although the response to IV ACTH tended to be faster at 3 days in those who had received previous steroid therapy. Intravenous ACTH and hydrocortisone are equally effective in achieving therapeutic goals in patients with Crohn's disease who have not achieved results with oral medications. Moreover the response rate was high (mean 88%), serving to buy time for establishment of successful maintenance programs of treatment with oral 5-ASA and immunosuppressive drugs for 69% of patients at 1-3 years.

Intravenous corticotrophin vs. hydrocortisone in the treatment of hospitalized patients with Crohn's disease: a randomized double-blind study and follow-up

Adrenocorticotrophic hormone (ACTH) and corticosteroids have no maintenance values for inflammatory bowel disease but serve to reduce the severity of disease. The effectiveness of intravenous corticotrophin versus hydrocortisone in ulcerative colitis has been determined including whether previous steroid therapy influenced the better response to one rather than the other, but no such studies have ever been done in Crohn's disease. Eighty-eight patients hospitalized with moderate-to-severe Crohn's disease (Present-Korelitz [P-K] Index -3 to -2 and the International Organisation for the Study of Inflammatory Bowel Disease-Crohn's & Colitis Foundation of America [IOIBD-CCFA] Index, mean 14, range 5-23) were treated in a prospective, randomized, double-blind clinical trial to receive either continuous intravenous infusion of 120 U/day of ACTH (44 patients) or hydrocortisone 300 mg/day (44 patients). Patients were also subdivided into those who received oral steroids during the 30 days prior to intravenous therapy and those who had not. Response was followed on a daily basis and tabulated at 3, 5, and 10 days. Patients were followed from 1-3 years to determine the later status. After 10 days of intravenous therapy 36 of 44 patients (82%) who received ACTH and 41 of 44 patients (93%) who received hydrocortisone fully responded (P-K index +3 and IOIBD-CCFA Index mean of 3). At the end of the study, response to intravenous ACTH and hydrocortisone was not statistically different whether or not patients received oral steroids during the 30 days prior to admission, although the response to IV ACTH tended to be faster at 3 days in those who had received previous steroid therapy. Intravenous ACTH and hydrocortisone are equally effective in achieving therapeutic goals in patients with Crohn's disease who have not achieved results with oral medications. Moreover the response rate was high (mean 88%), serving to buy time for establishment of successful maintenance programs of treatment with oral 5-ASA and immunosuppressive drugs for 69% of patients at 1-3 years.

Anorectal manometric characteristics in men and women with idiopathic fecal incontinence

To characterize and compare the anorectal manometric findings of men and women with idiopathic fecal incontinence referred to a tertiary care center for pelvic floor disorders, we reviewed 86 consecutive patients who underwent anorectal manometry during a 13-month period. We determined the etiologies of all patients and analyzed men and women with no obvious cause (idiopathic). The manometric parameters included resting and squeeze anal canal pressures, duration of squeeze pressures, threshold of external anal sphincter contraction, threshold of rectal sensation, and rectal compliance. Thirty-one of 86 patients were classified as having idiopathic fecal incontinence. The mean age of the 7 male patients with idiopathic fecal incontinence was 65 years, (range, 45-78 years) and 63 years (range, 38-83 years) in the 24 women. Compared with male patients, female patients had lower sphincteric pressures and shorter squeeze durations. Both men and women frequently exhibited poor phasic response of the external anal sphincter to rectal distention. We conclude that, compared with men, women with idiopathic fecal incontinence more often exhibit abnormalities of anal sphincteric motor function. The sex-related differences in muscle mass and past traumatic events related to childbirth may partly account for these findings.

Comparative effects of intravesical versus extravesical administration of ZD6169 and cromakalim on the response of the in vitro rat whole bladder to field stimulation

Potassium channel openers are currently being evaluated for their inhibitory effect on hyperreflexia. Increasing potassium permeability results in a hyperpolarization of the smooth muscle membrane and a reduction in calcium entry. This stabilizes the membrane and should result in the reduction of spontaneous contractile activity. Potassium channel agonists have been shown to be effective in the reduction of hyperreflexia secondary to outlet obstruction in rats, and certainly have been shown to reduce the contractile response of isolated tissues to a number of different agonists. In addition, intravesical administration of potassium channel openers have been shown to be effective against hyperreflexia (in rabbits) using intravesical administration, although relatively high concentrations had to be employed. Using an in vitro whole bladder model (rat), our current study compares the potency and efficacy of intravesical versus extravesical administration of two potassium channel openers for the inhibition of field-stimulated contraction. The results demonstrate that (1) the extracellular administration of ZD6169 and cromakalim were equally effective inhibitors of the contractile response to field stimulation, (2) low frequency stimulation was inhibited to a significantly greater degree than high frequency stimulation, (3) intravesical administration of ZD6169 was equally effective at inhibiting the response to low frequency field stimulation when compared to extravesical administration, (4) intravesical administration was less effective than extravesical administration at high frequency stimulation (although the inhibition was still statistically significant), and (5) intravesical administration of cromakalim did not inhibit field stimulation.

Reliability of the measurement of postprandial thermogenesis in men of three levels of body fatness

To determine the reliability of the measurement of postprandial thermogenesis by indirect calorimetry and to clarify further the relationship of obesity to thermogenesis in men, the thermic effect of a 720-kcal, mixed liquid meal was compared in 13 lean men (mean +/- SEM, 11.2% +/- 1.4% body fat), 10 average men (22.4% +/- 1.6% body fat), and 12 obese men (33.4% +/- 1.6% body fat) on two occasions. Resting metabolic rate (RMR) was measured for 3 hours: (1) in the fasted state, and (2) after a 720-kcal mixed liquid meal, on two occasions. The thermic effect of the meal, calculated as the postprandial energy expenditure minus the fasting RMR (kcal/3h), was greater for the lean and average men than for the obese men during both trials (P less than .001), but was only marginally different between the lean and average groups (P = .16). The mean values for the two trials were similar and the measurement of thermogenesis was highly reproducible with a reliability coefficient of r = .932 (P less than .001). Across all groups, thermogenesis correlated strongly with percent body fat (r = -.64, P less than .01), but within the average men, thermogenesis was uncorrelated with percent body fat (r = .09) but highly correlated with the glucose response to the meal (r = -.75, P less than .05). Thus, factors other than body fatness, such as insulin sensitivity, may determine thermogenesis within this heterogeneous middle group.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of exercise mode and intensity on postprandial thermogenesis in lean and obese men

To characterize further the impact of exercise before a meal on thermogenesis, the effects of exercise intensity and mode and the duration of the effect of exercise on the thermic effect (TEF) of a 720-kcal mixed meal were compared in 10 lean and 10 obese men (16 +/- 1 vs. 34 +/- 2% fat). In study A, TEF (kcal/3 h) was significantly greater for the lean than the obese men during rest and immediately after 1 h of cycling at 50 and 100 W. TEF was significantly greater after both exercise intensities than during rest for the obese men, but exercise had no effect on TEF in the lean men. In study B, TEF was significantly greater for the lean than the obese men during rest and immediately after 1 h of leg cycling at an O2 consumption of 1.09 l/min but only marginally different after 1 h of arm exercise at the same O2 consumption (P = 0.15). For the obese men, TEF was greater after arm than leg cycling and greater after leg cycling than at rest (P less than 0.01), but TEF was not different among the three conditions for the lean men. In study C, TEF was compared at rest and immediately and 24 h after 1 h of cycling at 100 W. TEF was greater for the lean than the obese men under all conditions (P less than 0.05). For the obese but not the lean men, TEF was greater both immediately after and on the day after exercise than at rest (P less than 0.01). Thus, acute exercise improves but does not normalize the blunted TEF in obesity; a minimally intense bout of exercise is needed to improve TEF; exercise mode alters thermogenesis in the obese men, even at a fixed intensity; and TEF in the obese men is enhanced for as long as 24 h after exercise.

Independent effects of obesity and insulin resistance on postprandial thermogenesis in men

The putative blunted thermogenesis in obesity may be related to insulin resistance, but insulin sensitivity and obesity are potentially confounding factors. To determine the independent effects of obesity and insulin resistance on the thermic effect of food, at rest and after exercise, lean and obese men were matched at two levels of insulin sensitivity determined by insulin-stimulated glucose disposal (milligrams per kilogram fat-free mass [FFM] per minute) during the euglycemic, hyperinsulinemic (40 mU/m2.min) clamp: 5.4 mg/kg FFM for the lean and obese groups with low insulin sensitivity, and 8.1 mg/kg FFM for the groups with high insulin sensitivity. The two lean groups were matched for percent fat (approximately 15 +/- 1% fat), as were the two obese groups (approximately 33 +/- 2% fat). Energy expenditure was measured for 3 h in the fasting state and for 3 h after a 720-kcal mixed meal, each at rest and immediately after 1 h of cycling at 100 W. The thermic effect of food (TEF) was calculated as the postprandial minus fasting energy expenditure (kcal/3 h) during rest and after exercise. During rest, TEF was blunted by both obesity (24 +/- 5 and 34 +/- 6 kcal/3 h for obese groups with low and high insulin sensitivity vs. 56 +/- 6 and 74 +/- 6 kcal/3 h for the lean groups with low and high insulin sensitivity; P less than 0.01 lean vs. obese) and insulin resistance (insulin-resistant less than insulin-sensitive, at both levels of obesity; P less than 0.01). After exercise, TEF was also impaired in the obese (47 +/- 6 and 44 +/- 5 kcal/3 h for the insulin-resistant and -sensitive groups) and in the lean insulin-resistant (55 +/- 5 kcal/3 h), compared with the lean insulin-sensitive men (71 +/- 3 kcal/3 h), P less than 0.01. Compared with rest, TEF after exercise was improved, but not normalized, in both obese groups (P less than 0.05), but unchanged in the lean groups. These results suggest that both insulin resistance and obesity are independently associated with impaired TEF at rest, but the responsiveness of thermogenesis to exercise before a meal is related to the obese state and not independently to insulin resistance per se.

Bioavailability of leuprolide acetate following nasal and inhalation delivery to rats and healthy humans

Systemic delivery of leuprolide acetate, a luteinizing hormone releasing hormone (LHRH) agonist, was compared after inhalation (i.h.) and intranasal (i.n.) administration. The i.n. bioavailability in rats was significantly increased by alpha-cyclodextrin (CD), EDTA, and solution volume. Intraanimal variability was 30-60%, and absorption ranged from 8 to 46% compared to i.v. controls. Studies in healthy human males were conducted with leuprolide acetate i.n. by spray, or inhalation aerosol (i.h.), and subcutaneous (s.c.) and intravenous (i.v.) injection. The s.c. injection was 94% bioavailable compared with i.v. The i.n. bioavailability averaged 2.4%, with significant subject-to-subject variability. Plasma peak concentrations (Cmax) with 1- and 3-mg dosages ranged between 0.24-1.6 and 0.10-11.0 ng/ml, respectively. The low human bioavailability may be due to physical loss of drug down the oral cavity and differences between human and rat nasal mucosa. Inhalation delivery gave a slightly lower intersubject variability. Mean Cmax with a 1-mg dose of solution aerosol was 0.97 ng/ml, compared with 4.4 and 11.4 ng/ml for suspension aerosols given at 1- and 2-mg bolus dosages, respectively. The mean bioavailability of the suspension aerosols (28% relative to s.c. administration) was fourfold greater than that of the solution aerosol (6.6%), suggesting that LHRH analogues may be delivered systemically via the lung as aerosol dispersions.

Estimation of extracellular and total body water by multiple-frequency bioelectrical-impedance measurement

This study evaluated a new technology of bioelectrical-impedance (BI) measurement that makes use of multiple frequencies (5, 50, and 100 kHz) for estimation of extracellular and total body water. In 36 healthy males, resistance and reactance at three frequencies were compared with extra-cellular water (ECW) and total body water (TBW) determined by isotope dilution. ECW was best predicted by resistance measured at 5 kHz, corrected for height and weight (R = 0.930, SEE = 1.94 L) whereas TBW was best predicted by resistance at 100 kHZ and weight (R = 0.947, SEE = 2.64 L). Cross-validation analysis on two randomly selected subsets (n = 18 each) indicated that the prediction equations were reproducible and valid. Thus, BI at dual frequencies is valid for determination of body-water compartments and may be useful in the nutritional assessment of patients in whom body water and hydration is of clinical concern.

Platelet activating factors (AGEPC) from epidermal secretions of the Arabian Gulf catfish, Arius bilineatus, which stimulate wound healing

High levels of platelet activating factor (PAF) activity were demonstrated by platelet aggregation and serotonin release assays to be present in fright induced epidermal secretions of the Arabian Gulf catfish, Arius bilineatus (Valenciennes, 1840). The PAF activity was purified by thin-layer chromatography. Mass spectral analysis combined with chemical and enzymatic modification of the purified PAF and inhibitor studies indicated that PAF activity was due to the presence of 1-O-alkyl-2-acetyl-sn-glycero-3-phosphorylcholine (AGEPC) molecules. The total AGEPC concentration in the epidermal secretions based on PAF assays was 8 x 10(8) M, well above the threshold level for platelet activation which is near 5 x 10(-11) M. Thus, stimulated epidermal secretory cells of Arius bilineatus supply platelet activating molecules at physiologically high concentrations to sites of injury.

In vitro intravesical instillation of anticholinergic, antispasmodic and calcium blocking agents (rabbit whole bladder model)

The systemic side effects accompanying oral pharmacotherapy of neurogenic bladder dysfunction present significant drawbacks to this type of therapy. In these studies we investigated the effect of intravesical administration of anticholinergic, antispasmodic and calcium blocking agents on pressure response mediated by field stimulation and bethanechol. We used the rabbit in vitro whole bladder model for these experiments. The bladder from a mature male NZW rabbit was mounted in an organ bath as a whole bladder preparation. After control field stimulation and bethanechol stimulation, 20 ml. of saline containing the specific drug being evaluated was instilled into the bladder. At 30 minute intervals, the responses to field stimulation and bethanechol were determined. Two hours after instillation of 100 microM of each specific drug, the inhibition of the contractile response to bethanechol and field stimulation (as % inhibition) was as follows: oxybutynin (95%/64%), verapamil (85%/81%), atropine (68%/31%), diltiazem (47%/39%), and imipramine (44%/47%). Atropine and oxybutynin suppressed the contractile response of the bladder to bethanechol to a much greater extent than that to field stimulation, while verapamil, diltiazem and imipramine suppressed the contractile response to bethanechol and field stimulation to approximately the same extent. Two hours after drug instillation, the intravesical solution was washed out and replaced with saline, but the recovery of the bladder contraction was slow and incomplete. The results of this study suggest that the use of self-intravesical instillation to suppress bladder contractility should be a good therapeutic approach for patients with neurogenic bladder, especially those who are already managed by intermittent catheterization.

Reduction of aspirin-induced ulcers by a new imidazoline anti-inflammatory agent

We have previously described the anti-inflammatory and low ulcerogenic actions of the formamidine pesticide, chlordimeform (CDM). In this study, the related basic compound, CDMI [2-(2-methyl-4-chlorophenylamino)-2-imidazoline], also demonstrated potent anti-edema (vs. carrageenin) and low ulcerogenic activity. A nonulcerogenic i.p. dose of CDMI reduced aspirin (ASA)-induced ulcers [lesion index (L.I.): 25.8 for ASA alond vs. 5.3 for ASA + i.p. CDMI]; prevented stress-induced ulcers in mice; and decreased acid secretion (by 90% in the Shay rat preparation). A mildly ulcerogenic oral dose (0.6 mmol/kg) of CDMI prevented stress ulcers, but did not reduce ASA ulcers. A nonulcerogenic oral dose (0.15 mmol/kg) of CDMI did reduce ASA ulcers (L.I.: 24.5 for ASA alone vs. 14.7 for ASA + oral CDMI). Thus, CDMI is a unique anti-inflammatory agent with additional anti-secretory and ulcer-reducing actions.