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Davis P. Physicians: our greatest potential resource for continuing medical education. J Rheumatol Suppl 1997; 24:1670-2. [PMID: 9292784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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252
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Haaseth RC, Zalewska T, Davis P, Yamamura HI, Porreca F, Hruby VJ. Para-substituted phenylalanine-4 analogues of [L-Ala3]DPDPE: highly selective delta opioid receptor ligands. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 1997; 50:171-7. [PMID: 9309580 DOI: 10.1111/j.1399-3011.1997.tb01182.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Several para-substituted Phe4 analogues of the delta 1-selective antagonist [L-Ala3]DPDPE (DPADPE) were prepared and evaluated for their brain-binding and in vitro pharmacological effects. Unlike the p-haloPhe4 analogues of DPDPE and the deltorphins, similar analogues of DPADPE with electron-withdrawing groups substituted at the para-position of the Phe4 aromatic ring did not all have increased potency and selectivity for delta opioid receptors, but all retained high potency and selectivity for delta opioid receptors greater than DPDPE.
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MESH Headings
- Animals
- Binding, Competitive
- Brain/drug effects
- Brain/metabolism
- Chromatography, High Pressure Liquid
- Chromatography, Thin Layer
- Enkephalin, D-Penicillamine (2,5)-
- Enkephalins/chemical synthesis
- Enkephalins/metabolism
- Enkephalins/pharmacology
- Guinea Pigs
- Ileum/drug effects
- Male
- Mass Spectrometry
- Mice
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Phenylalanine
- Rats
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/metabolism
- Vas Deferens/drug effects
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253
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Katsura Y, Zhang X, Homma K, Rice KC, Calderon SN, Rothman RB, Yamamura HI, Davis P, Flippen-Anderson JL, Xu H, Becketts K, Foltz EJ, Porreca F. Probes for narcotic receptor-mediated phenomena. 25. Synthesis and evaluation of N-alkyl-substituted (alpha-piperazinylbenzyl)benzamides as novel, highly selective delta opioid receptor agonists. J Med Chem 1997; 40:2936-47. [PMID: 9288176 DOI: 10.1021/jm970106d] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A series of N-alkyl- and N,N-dialkyl-4-[alpha-[(2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl] benzyl]-benzamides were synthesized and evaluated for binding affinities at mu, delta, and kappa opioid receptor subtypes. Several compounds (2e,f,h,i,m) strongly bound to the delta receptor with IC50 values in the nanomolar range. On the other hand, the binding affinities of these compounds for the mu and kappa receptors were in the micromolar or greater range indicating excellent delta opioid receptor subtype selectivities. In this series, two important structure-activity relationships were found for the delta receptor binding affinity. First, the spatial orientation of the alpha-benzylic position influenced the affinities with the alpha R derivatives 2a-n generally showing more than 10-fold greater affinity than the alpha S derivatives 3a-n. Second, the binding affinities were strongly influenced by the number of alkyl substituents on the amide nitrogen. N-Monoalkylbenzamide derivatives 2b-d showed lower affinity than N,N-dialkylbenzamide derivatives 2e-n, and the N-unsubstituted benzamide derivative 2a had the lowest affinity for the delta receptor in the series. The dramatic effect of the amide group substitution pattern on the binding affinity for the delta receptor strongly suggests that the amide function is an important structural element in the interaction of this series of compounds at the delta receptor. Selective compounds in this series were examined for binding affinity in cloned human mu and delta receptors. The results obtained generally paralleled those from the rat brain binding assay. Compounds 2e,f with potent delta binding affinities and high delta selectivities were shown to be delta agonists with high selectivity by studies in the guinea pig ileum (GPI) and mouse vas deferens (MVD) preparations. Compound 2f was the most selective compound in the rat brain and GPI/MVD assays with 1755- and 958-fold delta vs mu selectivity, respectively.
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MESH Headings
- Alkylation
- Animals
- Benzamides/chemical synthesis
- Benzamides/chemistry
- Benzamides/pharmacology
- Brain/metabolism
- CHO Cells
- Cell Membrane/metabolism
- Cricetinae
- Crystallography, X-Ray
- Guinea Pigs
- Humans
- Kinetics
- Male
- Mice
- Mice, Inbred ICR
- Models, Molecular
- Molecular Conformation
- Molecular Structure
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Muscle, Smooth/physiology
- Narcotics/agonists
- Narcotics/chemical synthesis
- Narcotics/chemistry
- Narcotics/pharmacology
- Piperazines/chemical synthesis
- Piperazines/chemistry
- Piperazines/pharmacology
- Radioligand Assay
- Rats
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, mu/metabolism
- Structure-Activity Relationship
- Transfection
- Vas Deferens/drug effects
- Vas Deferens/physiology
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254
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Meacham LR, Ghim TT, Crocker IR, O'Brien MS, Petronio J, Davis P, Vogel BC, Krawiecki NS. Systematic approach for detection of endocrine disorders in children treated for brain tumors. MEDICAL AND PEDIATRIC ONCOLOGY 1997; 29:86-91. [PMID: 9180908 DOI: 10.1002/(sici)1096-911x(199708)29:2<86::aid-mpo4>3.0.co;2-n] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Endocrine dysfunction can be challenging to diagnose in children treated for brain tumors. Treatments are available for hormonal replacement and when necessary, hormonal suppression. Without these endocrine treatment regimens, life can be unnecessarily difficult or unpleasant. An endocrine survey can be used to screen at-risk neuro-oncology patients once or twice a year to facilitate the recognition of endocrine dysfunction. It is hoped that through the use of a routine screening program, physicians will be able to diagnose and begin treatment of endocrine problems in a time-efficient manner.
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255
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Hyams J, Davis P, Lerer T, Colletti RB, Bousvaros A, Leichtner A, Benkov K, Justinich C, Markowitz J. Clinical outcome of ulcerative proctitis in children. J Pediatr Gastroenterol Nutr 1997; 25:149-52. [PMID: 9252900 DOI: 10.1097/00005176-199708000-00004] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Although the course of ulcerative proctitis in adults has been well described, little data are available concerning its clinical behavior in children and adolescents. This study sought to characterize the presentation, response to therapy, and long-term course of ulcerative proctitis in the pediatric population. METHODS A retrospective chart review was conducted at five pediatric gastroenterology centers. RESULTS A total of 38 subjects (mean age 11.6 years) were identified with ulcerative proctitis (mean follow-up 4.3 years). Symptoms were mild at diagnosis in 74% and moderate or severe in 26%. Thirty-two percent had a complaint of constipation at presentation. Cessation of symptoms was noted in 68% within 3 months of therapy, an additional 24% within 6 months, and 8% were still symptomatic despite 6 months of therapy. During any subsequent yearly follow-up interval, -55% of patients were asymptomatic, 40% had a chronic intermittent course, and < 5% were continuously symptomatic despite therapy. Eight subjects were treated with oral corticosteroids, one with 6-mercaptopurine, and one with cyclosporine. Extension of inflammation proximal to the rectosigmoid occurred in 11 of 38 subjects (29%), 0.5-11.3 years postdiagnosis. Seven of the 13 subjects (54%) followed for > or = 5 years had proximal extension of disease, and two had undergone colectomy. CONCLUSIONS Despite a mild presentation in most subjects, ulcerative proctitis seems to have a high risk of proximal extension of disease. The overall response to therapy seems to be similar to that reported for ulcerative colitis in children. Follow-up endoscopic evaluation of patients with ulcerative proctitis seems warranted, especially in the setting of recurrent or recalcitrant symptoms.
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256
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Davis P, Moss B, Anderson V, Ward C. The National 4-H Dairy Conference: A Youth Learning Experience. J Dairy Sci 1997. [DOI: 10.3168/jds.s0022-0302(97)76128-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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257
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Misicka A, Cavagnero S, Horvath R, Davis P, Porreca F, Yamamura HI, Hruby VJ. Synthesis and biological properties of beta-MePhe3 analogues of deltorphin I and dermenkephalin: influence of biased chi 1 Phe3 residues on peptide recognition for delta-opioid receptors. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 1997; 50:48-54. [PMID: 9273887 DOI: 10.1111/j.1399-3011.1997.tb00619.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Using the method of conformational constraint, we have designed and synthesized analogues of deltorphin I and dermenkephalin containing each of the four stereoisomers (2S,3S; 2S,3R; 2R,3S; 2R,3R) of the unusual amino acid beta-methylphenylalanine in position three. The potency and selectivity of these analogues were evaluated by radioreceptor binding assays in the rat brain using [3H]CTOP (mu-ligand) and[3H]p-C1Phe4]DPDPE (delta-ligand), and by bioassay using the mouse vas deferens (delta-receptor assay) and guinea pig ileum (mu-receptor assay) assays. The substitution of a beta-MePhe for Phe3 in deltorphin I and dermenkephalin has a large and variable effect on the bioactivities of the synthesized analogues. The synthesized analogues are somewhat less potent than the native peptides. Both [(2S,3R)-beta-MePhe3]deltorphin and [(2S,3R)-beta-MePhe3] dermenkephalin are more selective, however, and interact essentially specifically with the receptor in the binding assays and bioassays. The bioassay data in vitro of the synthesized analogues of deltorphin I and dermenkephalin follow the same general trends as the receptor binding data. These results demonstrate that topographical modifications of the side-chain conformation of critical structural moieties in a ligand can significantly modulate both the potency and receptor selectivity for ligands that have multiple sites of biological activity, and they illustrate that this approach has general application to peptide and peptidomimetic ligand design.
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258
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Suarez-Almazor M, Homik JE, Messina D, Davis P. Attitudes and beliefs of family physicians and gynecologists in relation to the prevention and treatment of osteoporosis. J Bone Miner Res 1997; 12:1100-7. [PMID: 9200010 DOI: 10.1359/jbmr.1997.12.7.1100] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The objective of this study was to evaluate the attitudes and beliefs of primary care physicians (PCPs) and obstetricians/gynecologists (O&Gs) in relation to the prevention and treatment of osteoporosis (OP) in postmenopausal women. A survey was mailed to a random sample of PCPs and to all O&Gs registered in the province of Alberta (Canada). The survey evaluated their practice patterns using closed-ended questions, Likert scaled items, and two case studies. Cases 1 and 2 were 52-year-old and 62-year-old healthy postmenopausal women, respectively, with no known risks for OP. Neither had received hormone replacement therapy (HRT). One hundred fifty-seven PCPs and 57 O&Gs participated in the study. Thirty-eight percent of the PCPs and 32% of the O&Gs stated that they never requested bone mineral density measurements (BMDm) in early postmenopausal women. Most would request BMDm only in the presence of risk factors. The most important criteria to request BMDm were chronic glucocorticoid use and recent fractures. For case 1, 7% of the PCPs and 11% of the O&Gs would request BMDm; 76% of the PCPs and 80% of the O&Gs would recommend HRT. For case 2, 29% of the PCPs and 47% of the O&Gs would request BMDm (p = 0.01); 43% of the PCPs and 49% of the O&Gs would prescribe HRT. In general, O&Gs were more inclined to intervene in relation to BMDm and HRT. O&Gs were also more likely to be influenced by clinical trials than PCPs (p < 0.001). Our findings show variations in the patterns of practice of physicians in relation to the prevention of OP. In general, use of densitometry appears to be low. The results of the case studies suggest that individual physician perceptions may be more influential than patient characteristics when requesting BMDm and prescribing HRT, particularly in older postmenopausal women. This group of healthy older women have approximately equal odds of being offered versus not being offered BMDm and HRT according to the physician they consult.
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259
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Shrivastava A, Davis P, Davies DP. SIDS: parental awareness and infant care practices in contrasting socioeconomic areas in Cardiff. Arch Dis Child 1997; 77:52-3. [PMID: 9279153 PMCID: PMC1717234 DOI: 10.1136/adc.77.1.52] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Parental awareness of risk factors for sudden infant death syndrome (SIDS) and infant care practices were compared in an area of relative deprivation and one of relative affluence in Cardiff. Awareness was high in both areas. More infants slept on the side in the deprived area (p < 0.02). One in three babies was exposed to cigarette smoking, significantly more in the deprived area (p < 0.001). Health professionals should discourage side sleeping and smoking, especially in areas of deprivation.
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260
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Figg WD, Christian MC, Lush R, Link CJ, Davis P, Kohn E, Sarosy G, Rothenberg ML, Weiss RB, Ryan N, Jacobs J, Reed E. Pharmacokinetics of elemental platinum (ultrafiltrate and total) after a thirty minute intravenous infusion of ormaplatin. Biopharm Drug Dispos 1997; 18:347-59. [PMID: 9158882 DOI: 10.1002/(sici)1099-081x(199705)18:4<347::aid-bdd23>3.0.co;2-o] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Preclinical data suggest that ormaplatin (tetrachloro-(dl-trans)-1, 2-diamminocyclohexaneplatinum) has substantial activity in cisplatin-resistant tumor models and may be less nephrotoxic than cisplatin. Based on these data we initiated a phase I clinical trial in patients with refractory metastatic cancer. This report characterizes the pharmacokinetic profile of both the total plasma concentrations of elemental platinum and the unbound ultrafiltrate concentrations of elemental platinum, following a 30 min intravenous infusion of ormaplatin. Platinum concentrations were determined by AAS, and pharmacokinetic parameters for both the total plasma concentration and the ultrafiltrate concentration of elemental platinum were determined using both compartmental and noncompartmental methods. Twenty-eight patients (14 males and 14 females; median age, 58) received ormaplatin. There was a linear relationship between Cmax and dose (r2 = 0.945) and AUC and dose (r2 = 0.976). Ormaplatin is more accurately described by a two-compartment model than by a one-compartment model. The distribution half-life (t1/2 alpha) was 0.3 h and the terminal half-life (t1/2 beta) was 39.1 h. The volume of the central compartment (V) was 68.6 L and the volume of distribution at steady state (Vdss) was 183 L. Like total plasma platinum, unbound platinum is also best characterized by a two-compartment model. The elimination of free platinum is also biphasic with a distribution half-life (t1/2 alpha) of 0.3 h and a terminal half-life (t1/2 beta) of 19.3 h. The mean volume of the central compartment (V) was 200.5 L, and the mean volume of distribution at steady state (Vdss) was 560.5 L. Clinical development of ormaplatin has been terminated due to increased frequency of neurological complications noted over other platinum agents; however, the pharmacokinetics are, in general, similar to those of other clinically used platinum compounds.
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261
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Starkebaum G, Loughran TP, Gaur LK, Davis P, Nepom BS. Immunogenetic similarities between patients with Felty's syndrome and those with clonal expansions of large granular lymphocytes in rheumatoid arthritis. ARTHRITIS AND RHEUMATISM 1997; 40:624-6. [PMID: 9125243 DOI: 10.1002/art.1780400406] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Patients with chronic clonal proliferation of large granular lymphocytes (LGL leukemia) often have splenomegaly, neutropenia, and rheumatoid arthritis (RA), thereby resembling the manifestations observed in patients with Felty's syndrome. The present study sought to determine whether patients with these disorders represent 2 distinct subsets of neutropenic RA. METHODS Prospective cohort study of outpatients attending clinics in university and private hospitals and in offices of private practice physicians. Twenty-two patients with Felty's syndrome and 22 patients with LGL leukemia, 10 of whom had RA, were studied. HLA genotyping was performed on peripheral blood mononuclear leukocyte genomic DNA. RESULTS Nineteen of the 22 patients with Felty's syndrome (86%) were DR4 positive. Nine of the 10 patients with LGL leukemia plus RA were also DR4 positive. In contrast, only 4 of the 12 patients with LGL leukemia without RA (33%) were DR4 positive, a frequency that was within the normal range. CONCLUSION The finding of an equally high prevalence of DR4 in patients with Felty's syndrome and in those with LGL leukemia plus RA suggests that both disorders have a similar immunogenetic basis and are parts of a single disease process rather than 2 separate disorders.
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262
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Asavatanabodee P, Sholter D, Davis P. Yttrium-90 radiochemical synovectomy in chronic knee synovitis: a one year retrospective review of 133 treatment interventions. J Rheumatol 1997; 24:639-42. [PMID: 9101494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To determine treatment success rates and factors predicting successful outcome using yttrium-90 intraarticular injections for chronic knee synovitis refractory to other treatments. METHODS A retrospective one year review of 133 treatment interventions with yttrium-90 (Y-90) with response recorded at 3, 6, 9, and 12 mo after injection. RESULTS An excellent, good, or fair response (a treatment benefit) as evaluated by objective (degree of joint effusion, joint tenderness, range of motion) and subjective (visual analog scale, degree of pain) assessments occurred in 81, 82, 80, and 75% of joints at 3, 6, 9, and 12 mo, respectively. When only excellent and good responses were considered successful treatment then 49, 48, 57, and 46% had successful treatment at 3, 6, 9, and 12 mo, respectively. 8 of 15 joints (53%) reinjected after primary treatment failure or relapse showed a beneficial response. Patients treated successfully were more likely to have a normal radiographic appearance rather than one showing destructive changes (78 vs 54% treatment success; p < 0.05); to have localized disease or systemic disease in remission, rather than active systemic disease (66 vs 30% treatment success; p < 0.001); and shorter duration of joint disease (6.9 vs 10.2 years; p < 0.05). CONCLUSION Y-90 synovectomy successfully treats patients with chronic knee synovitis refractory to other therapies. Primary treatment failures or relapses may be successfully treated by reinjection. Patients with less destructive radiographic changes, shorter duration of joint disease, and localized disease tend to respond more favorably.
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263
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Gentry B, Davis P, Dancer J. Failure rates of young patients with sickle cell disease on a hearing screening test. Percept Mot Skills 1997; 84:434. [PMID: 9106831 DOI: 10.2466/pms.1997.84.2.434] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
100 young subjects with sickle cell disease were screened for hearing loss at the Sickle Cell Clinic at Children's Hospital. 12% of the sample failed, which is higher than prevalence rates for the age groups suggest. Routine screening of hearing is suggested as the first step in the audiologic rehabilitation process.
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264
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Gentry B, Hayes BT, Dancer J, Davis P. Language and motor skills of preschool children with sickle cell disease. Percept Mot Skills 1997; 84:486. [PMID: 9106837 DOI: 10.2466/pms.1997.84.2.486] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Language skills of 9 African-American preschool children with sickle cell disease were not significantly different from those of nondiseased children but gross and fine motor skills were.
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265
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Calderon SN, Rice KC, Rothman RB, Porreca F, Flippen-Anderson JL, Kayakiri H, Xu H, Becketts K, Smith LE, Bilsky EJ, Davis P, Horvath R. Probes for narcotic receptor mediated phenomena. 23. Synthesis, opioid receptor binding, and bioassay of the highly selective delta agonist (+)-4-[(alpha R)-alpha-((2S,5R)-4-Allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl]- N,N-diethylbenzamide (SNC 80) and related novel nonpeptide delta opioid receptor ligands. J Med Chem 1997; 40:695-704. [PMID: 9057856 DOI: 10.1021/jm960319n] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The highly selective delta (delta) opioid receptor agonist SNC 80 [(+)-4- [(alpha R)-alpha-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl]-N ,N- diethylbenzamide, (+)-21] and novel optically pure derivatives were synthesized from the enantiomers of 1-allyl-trans-2,5-dimethylpiperazine (2). The piperazine (+/-)-2 was synthesized, and its enantiomers were obtained on a multigram scale in > 99% optical purity by optical resolution of the racemate with the camphoric acids. The absolute configuration of (+)-2 was determined to be 2S,5R by X-ray analysis of the salt with (+)-camphoric acid. Since the chirality of the starting material was known, and the relative configuration of compounds (-)-21, (-)-22, and (+)-23 were obtained by single-crystal X-ray analysis, the assignment of the absolute stereochemistry of the entire series could be made. Radioreceptor binding studies in rat brain preparations showed that methyl ethers (+)-21 (SNC 80) and (-)-25 exhibited strong selectivity for rat delta receptors with low nanomolar affinity to delta receptors and only micromolar affinity for rat mu (mu) opioid receptors. Compounds (-)-21, (-)-22, and (-)-23 showed micromolar affinities for delta opioid receptors. The unsubstituted derivative (+)-22 and the fluorinated derivative (-)-27 showed > 2659- and > 2105-fold delta/mu binding selectivity, respectively. The latter derivatives are the most selective ligands described in the new series. Studies with some of the compounds described in the isolated mouse vas deferens and guinea pig ileum bioassays revealed that all were agonists with different degrees of selectivity for the delta opioid receptor. These data show that (+)-21 and (+)-22 are potent delta receptor agonists and suggest that these compounds will be valuable tools for further study of the delta opioid receptor at the molecular level, including its function and role in analgesia and drug abuse.
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MESH Headings
- Animals
- Benzamides/chemical synthesis
- Benzamides/chemistry
- Benzamides/metabolism
- Benzamides/pharmacology
- Binding, Competitive
- Brain/metabolism
- Crystallography, X-Ray
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-
- Enkephalin, Leucine-2-Alanine/metabolism
- Enkephalins/metabolism
- Guinea Pigs
- Ileum/metabolism
- Magnetic Resonance Spectroscopy
- Male
- Mice
- Molecular Conformation
- Molecular Structure
- Muscle Contraction/drug effects
- Piperazines/chemical synthesis
- Piperazines/chemistry
- Piperazines/metabolism
- Piperazines/pharmacology
- Radioligand Assay
- Rats
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, mu/metabolism
- Stereoisomerism
- Vas Deferens/metabolism
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266
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Gultom E, Doyle LW, Davis P, Dharmalingam A, Bowman E. Changes over time in attitudes to treatment and survival rates for extremely preterm infants (23-27 weeks' gestational age). Aust N Z J Obstet Gynaecol 1997; 37:56-8. [PMID: 9075548 DOI: 10.1111/j.1479-828x.1997.tb02218.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We determined the changes over time in attitude to treatment of very preterm infants (23-27 weeks of gestational age) born at the Royal Women's Hospital, Melbourne, and their survival rate. The subjects were consecutive livebirths at 23-27 weeks' gestational age born from 1983-1994, inclusive. The main outcomes measured were the proportions of livebirths treated intensively and survival rates to hospital discharge, both excluding lethal abnormalities. Over the 12 years of the study there were 788 livebirths free of lethal abnormalities born at 23-27 week's gestational age. Overall 669 (85%) were treated intensively; the proportions treated intensively rose significantly over time from 74% in 1983-1985 to 91% in 1992-1994, and with increasing gestational age, from 19% at 23 weeks to 100% at 27 weeks. Overall 439 (56%) survived their primary hospitalization; the survival rate rose significantly over time, from 43% in 1983-1985 to 70% in 1992-1994, and with increasing gestational age, from 3% at 23 weeks to 78% at 27 weeks. In 1992-1994, the survival rates were 11% at 23 weeks, 53% at 24 weeks, 70% at 25 weeks, 81% at 26 weeks, and 87% at 27 weeks. For infants treated intensively, the survival rate rose significantly from 53% in 1983-1985 to 76% in 1992-1994. The largest increases in survival have occurred in the 1990s, and at 24 and 25 weeks' gestational age. The proportions of very preterm infants treated intensively and their survival rates have increased over time, and have always been higher with increasing gestational age.
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267
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Kramer TH, Bartosz-Bechowski H, Davis P, Hruby VJ, Porreca F. Extraordinary potency of a novel delta opioid receptor agonist is due in part to increased efficacy. Life Sci 1997; 61:129-35. [PMID: 9217271 DOI: 10.1016/s0024-3205(97)00367-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A new cyclic opioid peptide of sequence Tyr-D-Pen-Gly-Phe-Cys-Phe (HBP2) was examined in the mouse isolated vas deferens (MVD) bioassay. Studies with receptor-selective opioid antagonists showed the peptide to be highly selective for delta opioid receptors. HBP2 and the standard delta agonist DPDPE were simultaneously compared using the technique of partial irreversible receptor blockade; data were analyzed using the operational model of pharmacologic agonism. HBP2 was approximately 160 times as potent as DPDPE; estimation of the affinity and efficacy of the two peptides revealed that the potency increase was due to a 5.3-fold increase in efficacy, as well as a 37-fold increase affinity. This contrasts with our previous findings with other cyclic enkephalin analogs, in which increased affinity was achieved without a change in apparent efficacy. Analysis of concentration-response curve shape suggested in addition the possibility of heterogeneity in transduction mechanisms for MVD delta receptors.
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268
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Stewart A, Davis P, Kittner S, Langenberg P. The effect on risk estimates of excluding cases from a case-control study of ischemic stroke. Neuroepidemiology 1997; 16:191-8. [PMID: 9267836 DOI: 10.1159/000109687] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
There is limited information about the effect on stroke risk estimates of excluding cases who are unable to respond to interviews. A case-control study of ischemic stroke between 1988 and 1990 in Shreveport, La., USA, provided a basis for studying this question. Of 197 consecutively admitted cases of ischemic stroke, 77 were excluded due to dementia, aphasia or impaired consciousness. Information about risk factors and stroke characteristics was obtained from hospital records. Excluded cases had more left hemispheric (52 versus 19%) and fewer vertebrobasilar (12 versus 29%) and lacunar (5 versus 13%) infarcts than included cases. Excluded cases were also older (p < 0.01), and they had larger infarcts (p < 0.01), multiple strokes (p < 0.01) and congestive heart failure (p < 0.01) more often than included cases. Cases were matched to hospital controls by age, sex, race, and date of admission. Odds ratios (ORs) were higher for excluded cases for 5 of 6 exposures with a significantly higher OR for congestive heart failure (p < 0.01). The ORs changed by as much as 63% when excluded cases were added. These results emphasize the importance of acquiring information about excluded cases and considering selection bias when interpreting stroke studies that exclude cases who are unable to respond to interviews.
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269
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Misicka A, Lipkowski AW, Horvath R, Davis P, Porreca F, Yamamura HI, Hruby VJ. Structure-activity relationship of biphalin. The synthesis and biological activities of new analogues with modifications in positions 3 and 4. Life Sci 1997; 60:1263-9. [PMID: 9096243 DOI: 10.1016/s0024-3205(97)00069-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
New analogues of biphalin [(Tyr-D-Ala-Gly-Phe-NH-)2] with modifications of amino acid residues in positions 3,3' and 4,4' have been synthesized. The potency and selectivity of these analogues were evaluated by competitive radioreceptor binding assay in the rat brain using [3H]CTOP (mu ligand) and [3H][p-Cl-Phe4]DPDPE (delta ligand) as ligands, and by bioassay in the mouse vas deferens (MVD, delta receptor assay) and guinea pig ileum (GPI, mu receptor assay). The symmetrical substitution of phenylalanine in positions 4 and 4' with p-fluorophenylalanine or p-nitrophenylalanine resulted in an enhancement of the affinity at both delta and mu receptors, with some increase of the selectivity for delta opioid receptors. The analogue containing p-chlorophenylalanine in positions 4 and 4' is the most selective to the delta receptors in this series, with a selectivity ratio about 5. The symmetrical substitution of the glycine-3 residue with phenylalanine resulted in a decrease of binding affinities and biological potencies at both mu & delta receptors.
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MESH Headings
- Analgesics/chemical synthesis
- Analgesics/chemistry
- Analgesics/pharmacology
- Animals
- Brain/drug effects
- Brain/metabolism
- Dose-Response Relationship, Drug
- Enkephalin, D-Penicillamine (2,5)-
- Enkephalins/chemical synthesis
- Enkephalins/chemistry
- Enkephalins/metabolism
- Enkephalins/pharmacology
- Guinea Pigs
- Ileum/metabolism
- Male
- Mice
- Mice, Inbred ICR
- Muscle Contraction/drug effects
- Muscle, Smooth/metabolism
- Radioligand Assay
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, mu/metabolism
- Somatostatin/analogs & derivatives
- Somatostatin/metabolism
- Structure-Activity Relationship
- Vas Deferens/metabolism
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270
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Bonner GG, Davis P, Stropova D, Ferguson R, Yamamura HI, Porreca F, Hruby VJ. Opioid peptides: simultaneous delta agonism and mu antagonism in somatostatin analogues. Peptides 1997; 18:93-100. [PMID: 9114458 DOI: 10.1016/s0196-9781(96)00242-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Four isomers of the Somatostatin analogue H-D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP) were made with beta-MePhe in position 1 and assayed for opioid binding in rat brain, biological activity in MVD and GPI bioassays, and antinociception in mouse warm-water tail flick assays. The analogues displayed varying potencies and biological activities including: simultaneous delta receptor agonism/mu receptor antagonism, mu receptor antagonism, and delta receptor agonism. These analogues demonstrated that the N-terminal residue is important for receptor potency/selectivity and signal transduction. These analogues my represent leads to therapeutic agents that yield analgesia via delta agonist effects, yet lack side effects associated with mu activity.
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MESH Headings
- Analgesics/pharmacology
- Animals
- Binding, Competitive
- Brain/metabolism
- Chromatography, High Pressure Liquid
- Chromatography, Thin Layer
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-
- Enkephalin, D-Penicillamine (2,5)-
- Enkephalins/metabolism
- Guinea Pigs
- Ileum/drug effects
- Male
- Mice
- Molecular Structure
- Opioid Peptides/chemical synthesis
- Opioid Peptides/chemistry
- Opioid Peptides/pharmacology
- Peptide Fragments
- Peptides/pharmacology
- Protein Binding/drug effects
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, mu/antagonists & inhibitors
- Somatostatin/analogs & derivatives
- Somatostatin/pharmacology
- Vas Deferens/drug effects
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271
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Martin M, Davis P, Dancer J. Conversations between older men and women: turn-taking and topics. Percept Mot Skills 1996; 83:1330. [PMID: 9017748 DOI: 10.2466/pms.1996.83.3f.1330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Five dyads of older men paired with older women were compared on the pragmatic variables of turn-taking and topicalization. Men talked longer and more often while women served to reinforce and maintain the conversational topics.
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272
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Baliga M, Singh GK, Davis P, Philip G. Spindle cell carcinoma of right lower alveolus. A case report. Indian J Dent Res 1996; 7:140-2. [PMID: 9495130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
A case report of spindle cell carcinoma of the right mandibular alveolus is reported, which clinically mimicked a squamous cell carcinoma. Careful histological interpretation is necessary for successful treatment of such tumors. The use of radiation therapy after radical neck dissection is also stressed upon.
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273
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Davis P, Bazar K, Huper G, Lozano G, Marks J, Iglehart JD. Dominance of wild-type p53-mediated transcriptional activation in breast epithelial cells. Oncogene 1996; 13:1315-22. [PMID: 8808706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The p53 gene is a recessive oncogene whose loss of function can result in cell transformation. Approximately 25% of human breast cancers contain missense mutations in one p53 allele, leading to inactivation of the mutated protein. In almost all of these cases, the wild-type allele is also lost. However, it remains uncertain whether mutant p53 acts in a dominant negative fashion over the wild-type protein. Two parameters of p53 function, transcriptional activation and transcriptional repression, were studied under a variety of experimental conditions within malignant and normal breast epithelial cells. Transient transfection of DNA encoding wild-type p53 was able to transactivate p53-responsive promoters. Wild-type p53 functioned equally well in malignant cells which harbored an endogenous mutation in p53, in malignant cells containing normal p53 and in normal mammary epithelial cells. Co-transfection of cDNAs encoding mutant p53 proteins were unable to inhibit the ability of wild-type p53 to transactivate the reporter constructs. Repression of viral promoters by normal p53 protein was not inhibited by endogenous or co-transfected mutant p53 -proteins. Finally, the p53 regulated gene WAF1/CIP1/p21 was induced following gamma irradiation in normal mammary cells, containing endogenous wild-type p53 and in the same cells transfected with mutant p53 genes. From these experiments we conclude that mutant p53 proteins do not inactivate the transactivating (or repressing) function of a co-expressed normal p53 protein in these cells implying that complete loss of wild-type p53 is required to eliminate these functions in breast epithelium.
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274
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Abstract
Evidence of the influence of research on health policy is paradoxical. While there is scant evidence that research has had any impact on the direction or implementation of widespread health reforms, research on evidence-based medicine has dramatically increased, despite limited evidence that it has affected clinical practice. These developments have occurred in the context of a general decline in state intervention and provision and a post-modern questioning of researchers' authority. Models of the relationship between research and policy range from one where empirical research rationally informs decision-making, through research incrementally affecting policy, to an "enlightenment" or "infiltration" model, which may operate on a conceptual level. Health research that contributes to large-scale socio-political change may require more methodological pluralism and greater focus on key institutional structures. Case studies reviewed suggest that dissemination is enhanced if researchers involve managers and policy-makers in the development of the framework for and focus of research and if investigators assume a responsibility for seeing their research translated into policy. Public health research is more influential if topical, timely, well-funded and carried out by a collaborative team that includes academics. Evaluations are more influential if, in addition, they are commissioned by health authorities but based on local collection of data, and instruments and incentives to implement policy are available. In some areas, such as the recent policy focus on careers in the community, researchers were largely responsible for raising this policy issue, whereas in other areas, such as the relationship between unemployment and health, researchers are just one of the groups of experts making competing claims about causality. In conclusion, clear research findings are not always a passport to policy, but researchers can reframe the way health policy issues are seen, and collaboration with policy-makers initially can enhance implementation later.
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275
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Simon OR, Powell N, Davis P, Gossell M. Evidence that guanylate cyclase is involved in modulating the resting tension and neurally-induced contraction of the guinea pig tracheal muscle. W INDIAN MED J 1996; 45:89-91. [PMID: 8952429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Electrical field stimulation of guinea-pig tracheal muscle strips produced a frequency-dependent biphasic response consisting of an initial cholinergic contraction followed by relaxation. Both phases of the response were of neural origin. In the presence of methylene blue, a guanylate cyclase inhibitor, the resting tension and the contraction were increased, but the accompanying relaxation was inhibited. However, in the presence of sodium nitroprusside, a guanylate cyclase activator, the resting tension was reduced and the contraction was inhibited, but the relaxation was prolonged and increased. Similarly, in the presence of either 3-isobutyl-1-methylxanthine, which promotes cyclic guanosine monophosphate (cGMP) accumulation, or 8-bromo-cGMP, an analogue of cGMP, the resting tension was reduced and the contraction was inhibited but the relaxation was prolonged and increased. From these results, it is concluded that guanylate cyclase is involved in modulating the resting tension and the neurally-induced contraction of guinea-pig tracheal muscle.
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