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Biomedical subjects

J Frazier

Publications and source records attributed to J Frazier.

At least 19 recordsLinked to original sources
PubMed1999

Efficacy of sustained blood levels of interleukin-1 receptor antagonist in animal models of arthritis: comparison of efficacy in animal models with human clinical data.

OBJECTIVE: To determine the role of interleukin-1 receptor antagonist (IL-1Ra) in rat adjuvant arthritis and rat type II collagen-induced arthritis, and to compare the efficacy in rat models with that seen in human clinical trials of IL-1Ra. METHODS: Rats with developing adjuvant arthritis or established collagen-induced arthritis were treated with IL-1Ra by continuous infusion in order to determine and maintain efficacious blood levels of this IL-1 inhibitory protein in the rats for comparison with human clinical data. The effects of treatment in the rats were monitored by sequential caliper measurement of the ankle joints, determination of final paw weights, and histologic evaluation with particular emphasis on bone and cartilage lesions. The effects of IL-1Ra on joint swelling and radiographic bone damage in patients with rheumatoid arthritis (RA) in a 6-month trial were compared with the findings in rats. RESULTS: Dramatic differences in the profile of IL-1Ra activity were seen between the 2 groups of rats. Modest antiinflammatory effects were observed in the adjuvant arthritis rats treated with IL-1Ra. However, marked inhibition of bone resorption occurred, even at doses with which antiinflammatory activity was not seen. In contrast, IL-1Ra treatment of rats with established collagen-induced arthritis resulted in nearly complete suppression of all aspects of the disease when adequate blood levels of IL-1Ra were maintained. Treatment of RA patients with IL-1Ra (150 mg daily) resulted in modest inhibition of joint swelling and inhibition of radiographic progression of bone lesions. CONCLUSION: IL-1 appears to be of major importance in mediating the bone resorption that occurs in rat adjuvant arthritis, but is less important in the pathogenesis of periarticular inflammation in this disease. In contrast, IL-1 is of major importance in mediating all aspects of disease progression in rat collagen-induced arthritis. Similar to the response in adjuvant arthritic rats, RA patients treated with IL-1Ra showed only modest antiinflammatory activity, but had evidence of inhibition of progression of bone resorption. However, a comparison of the plasma levels of IL-1Ra in humans and rats suggests that the optimal level of dosing for continuous saturation of IL-1 receptors may not have been achieved in humans, although this was achieved in the rat studies.

Animals↗
PubMed1999

Combination benefit of PEGylated soluble tumor necrosis factor receptor type I (PEG sTNF-RI) and dexamethasone or indomethacin in adjuvant arthritic rats.

OBJECTIVE: To determine the potential combination benefit receptor of treatment with PEGylated soluble tumor necrosis factor type I (PEG sTNF-RI) and dexamethasone (dex) or indomethacin (indo) in adjuvant arthritic rats. SUBJECTS: 160 male Lewis Rats. TREATMENT: PEG sTNF-RI, dex, indo. METHODS: Rats with adjuvant arthritis were given daily oral dex (0.025 or 0.006 mg/kg) or indo (0.5 or 0.25 mg/kg) day 9-14, alone or in combination with PEG sTNF-RI (sc on days 9, 11, and 13 of arthritis). Efficacy was monitored by volume measurement of ankle joints, final paw weights and histologic evaluation with particular emphasis on bone lesions. RESULTS: Treatment with 1 mg/kg PEG sTNF-RI alone resulted in 27% inhibition of final paw weights, dex alone (0.025 mg/kg) gave 25% inhibition and the combination resulted in 58% inhibition. Histologic evaluation of ankle joints demonstrated 48% inhibition of bone resorption with PEG sTNF-RI alone, 55% inhibition with dex alone and the combination treatment inhibited bone resorption by 100%. Inactive doses of PEG sTNF-RI (0.3 mg/kg) and dex (0.006 mg/kg) when combined resulted in 39% inhibition of paw swelling (AUC) and 39% inhibition of bone resorption. Combination treatment with indomethacin resulted in slight additive effects on inflammation parameters but no additive effects on bone resorption. CONCLUSION: Combination therapy with PEG sTNF-RI and dexamethasone results in additive or synergistic effects depending on the dose. Combination therapy with indomethacin resulted in slight additive effects on paw swelling parameters, but no additive benefit on bone resorption. Data from these studies support the clinical investigation of the use of combination therapy of PEG sTNF-RI and dex or other corticosteroids in rheumatoid arthritis patients.

Animals↗
PubMed1999

Controlled trial of high doses of pemoline for adults with attention-deficit/hyperactivity disorder.

Despite the increasing awareness of attention-deficit/hyperactivity disorder (ADHD) in adults, there are a limited number of controlled pharmacologic studies of this disorder. Because the stimulant medication magnesium pemoline (Cylert, Abbott Laboratories, Abbott Park, IL) has been found effective in treating ADHD in pediatric groups, we tested its efficacy in adults with ADHD using higher daily doses than those previously studied. We conducted a 10-week, double-blind, placebo-controlled, crossover design study of pemoline at a target daily dose of 3 mg/kg per day in 35 adult patients with DSM-III-R and -IV ADHD. We used standardized structured psychiatric instruments for diagnosis. To measure improvement, we used separate assessments of ADHD, depressive, and anxiety symptoms at baseline and at each biweekly visit. ADHD outcome was determined using the ADHD symptom checklist and Clinical Global Impression scales of Severity and Improvement. Of the 35 adults with ADHD who were randomized in the trial, 27 (77%) completed the protocol. Treatment with pemoline in the final week of the 4-week active phase was best tolerated at doses substantially lower than the target dose of 3 mg/kg per day (mean dose, 2.2 mg/kg per day; mean+/-SD, 148+/-95 mg). Pemoline was significantly better at reducing ADHD symptoms compared with placebo (z = 2.4,p < 0.02). Using a predefined 30% reduction in symptoms as an indication of improvement, 50% of pemoline-treated subjects and 17% of subjects in the placebo group were considered positive responders (chi2 = 7.1, p = 0.008). These results indicate that pemoline is moderately effective in the treatment of ADHD in adults. Although robust doses were targeted, most adults preferred more moderate dosing (120-160 mg/day). Given the limited efficacy, tolerability, and concerns of hepatic dysfunction, pemoline should be considered as second-line medication for treating ADHD in adults.

Adult↗
PubMed1999

Dopamine D4 gene 7-repeat allele and attention deficit hyperactivity disorder.

OBJECTIVE: Family, twin, and adoption studies show attention deficit hyperactivity disorder (ADHD) to have a substantial genetic component, and some studies have reported an association between ADHD and the dopamine D4 (DRD4) gene. METHOD: The authors recruited 27 triads that comprised an ADHD adult, his or her spouse, and their ADHD child. These triads were assessed for ADHD, and their DNA was genotyped for DRD4 alleles. RESULTS: A multiallelic transmission disequilibrium test suggested an association between ADHD and the DRD4 7-repeat allele. Among family members, the number of 7-repeat alleles predicted the diagnosis of ADHD. CONCLUSIONS: Prior reports of an association between ADHD and DRD4 generalize to families recruited through clinically referred ADHD adults. However, because there are some conflicting studies, further work is needed to clarify the role of DRD4 in the etiology of the disorder.

Adult↗
PubMed1999

Effects of interleukin 1 receptor antagonist alone and in combination with methotrexate in adjuvant arthritic rats.

OBJECTIVE: To determine the benefit of combination treatment with the interleukin 1 receptor antagonist (IL-1ra) and methotrexate (MTX) in adjuvant arthritic rats. METHODS: Rats with adjuvant arthritis were treated by continuous sc infusion with IL-1ra (5 mg/kg/h). Effects of IL-1ra treatment alone were compared to treatment with daily oral MTX (0.048, 0.06, or 0.075 mg/kg) or MTX in combination with IL-1ra. Efficacy was monitored by sequential caliper measurement of ankle joints, final paw weights, and histologic evaluation with particular emphasis on bone lesions. RESULTS: Treatment with IL-1ra alone resulted in 6% inhibition of paw swelling assessed by final paw weight. Treatment with MTX (0.075 mg/kg PO) gave 47% inhibition and the combination resulted in an 84% decrease in swelling. Histologic evaluation of ankle joints revealed 53% inhibition of bone resorption with IL-1ra alone, 58% inhibition with MTX alone, and 97% inhibition in combination treated rats. Lower doses of MTX in combination with IL-1ra also provided additive benefit on arthritis variables. CONCLUSION: Combination therapy with IL-1ra and MTX results in additive or synergistic benefit, with excellent inhibition of all arthritis variables. These data support clinical investigation of the use of combination therapy of IL-1ra and MTX in patients with rheumatoid arthritis.

Animals↗
PubMed1999

Antiarthritic activity of soluble tumor necrosis factor receptor type I forms in adjuvant arthritis: correlation of plasma levels with efficacy.

OBJECTIVE: To determine the importance of tumor necrosis factor (TNF) in the pathogenesis of adjuvant disease in rats and to determine plasma levels of recombinant soluble TNF receptor type I (sTNF-RI) necessary for efficacy, to project dosing for human clinical trials. METHODS: Rats with adjuvant arthritis were treated by continuous infusion with sTNF-RI forms to maintain blood levels of this TNF-alpha inhibitory protein. In addition, rats were given bolus injections of polyethylene glycol linked sTNF-RI and efficacy and plasma levels were determined. Effects of treatment in the rats were monitored by sequential volume or diameter measurement of ankle joints, final paw weights, and histologic evaluation of ankle joints, with particular emphasis on bone erosive lesions. RESULTS: In all studies and regardless of dosing methodology (bolus vs continuous infusion), minimal plasma levels for efficacy were in the 0.3-0.5 microg/ml range. Higher plasma levels resulted in greater efficacy, with maximal effects achieved when plasma levels were in the 5 microg/ml range. Beneficial effects of treatment were seen on body weight, paw swelling, splenomegaly, hepatomegaly, and bone resorption. CONCLUSION: TNF-alpha is an important mediator of all aspects of rat adjuvant disease including both the destructive processes in the joints as well as the systemic manifestations of adjuvant disease. Studies using various forms of sTNF-RI consistently show that plasma levels of 0.3-0.5 microg/ml are required for minimal efficacy and that higher plasma levels show dose-responsive enhanced efficacy.

Animals↗
PubMed1998

Effects of interleukin-1 receptor antagonist in a slow-release hylan vehicle on rat type II collagen arthritis.

PURPOSE: To determine the effect of hylan fluid (HA), a model slow release vehicle on the pharmacokinetic profile and efficacy of interleukin-1 receptor antagonist (IL-1ra) in rats with established type II collagen arthritis. METHODS: Female Lewis rats with type II collagen arthritis were treated daily, every other day or every third day with single subcutaneous (sc) injections of IL-1ra formulated in HA and the effects on arthritis determined. Results were compared to those obtained with IL-1ra in citrate buffered saline with EDTA and polysorbate (CSEP). Sequential blood levels were determined in rats injected sc with IL-1ra in CSEP or HA. RESULTS: Incorporation into HA led to slower release of IL-1ra into the bloodstream and maintained therapeutic blood levels of IL-1ra for a longer time compared to the IL-1ra/CSEP formulation. Single daily sc doses of 100 mg/kg IL-1ra in CSEP were ineffective in type II collagen arthritis. By contrast, once per day dosing of 100 mg/kg IL-1ra in HA provided 78% inhibition of paw swelling. Every other day dosing with 100 mg/kg IL-1ra in HA resulted in 62% inhibition. IL-1ra (100 mg/ kg in HA) given every third day provided 19% inhibition of arthritis. Improved efficacy correlated with improved pharmacokinetics. CONCLUSIONS: Administration of IL-1ra in the slow release vehicle HA improves pharmacokinetics and efficacy in rat type II collagen arthritis.

Animals↗
PubMed1998

Double-blind and placebo-controlled study of lithium for adolescent bipolar disorders with secondary substance dependency.

OBJECTIVE: To perform a double-blind, placebo-controlled, random assignment, parallel group, pharmacokinetically dosed study of lithium for adolescents with bipolar disorders (BP) and temporally secondary substance dependency disorders (SDD). METHOD: Subjects were 16.3 +/- 1.2 years old and were comprehensively assessed during a 6-week outpatient protocol that included random weekly urine collection for drug assays and random and weekly serum collection for lithium levels. RESULTS: Using both intent-to-treat (N = 25) and completer (n = 21) analyses, there were significant differences on continuous and categorical measures between the active and placebo groups for both psychopathology measures and weekly random urine drug assays. The mean scheduled weekly serum lithium level of active responders was 0.9 mEq/L. Addiction to both alcohol and marijuana was the most frequent category of SDD. Mean age at onset of BP was 9.6 +/- 3.9 years and of SDD was 15.3 +/- 1.3 years. There were multigenerational mood disorders in 96% and multigenerational SDD in 56% of families. CONCLUSIONS: Lithium treatment of BP with secondary SDD in adolescents was an efficacious treatment for both disorders. These results warrant replication with a long-term maintenance phase. The mean 6-year interval between the onset of BP and onset of SDD strongly argues for earliest recognition of BP.

Adolescent↗
PubMed1998

Pharmacokinetics, immunogenicity, and efficacy of dimeric TNFR binding proteins in healthy and bacteremic baboon.

Immunogenicity, pharmacokinetics, and therapeutic efficacy of three novel dimeric soluble tumor necrosis factor (TNF)-receptor I constructs [TNF-binding protein (bp)] were evaluated in 28 baboons, 12 of which were healthy and 16 were challenged with a lethal Escherichia coli bacteremia. The three constructs differed only in the number of extracellular domains of the TNF receptor I and were dimerized with polyethylene glycol. Although all three constructs had generally similar pharmacokinetics when administered to a naive animal, they differed quantitatively in their immunogenicity. Antibodies were detected more frequently, and titers were significantly higher (P < 0.05) in both healthy and septic baboons that received the 4.0-domain TNF-bp construct, compared with animals receiving the 2.6-domain construct. When the TNF-bp constructs were administered a second time (21 days later), the half-lives of the three constructs were significantly shorter in animals that had an antibody response after the first injection. In contrast, all three TNF-bp constructs were equally effective at improving outcome, blocking a systemic TNF-alpha response, and attenuating the cytokine responses when administered at a dose of 1.0 mg/kg body wt 1 h before a lethal E. coli infusion. The findings suggest that immunogenicity of TNF-bp constructs can be altered by changing the number of functional domains, without affecting their capacity to neutralize TNF-alpha and to abrogate TNF-mediated pathology.

Animals↗
PubMed1997

Mania in children with pervasive developmental disorder revisited.

OBJECTIVE: Although a small literature of case reports suggests that mania co-occurs with pervasive developmental disorder (PDD), little is known about this overlap. The authors systematically investigated the overlap between mania and PDD in a consecutive sample of referred youths, examining its prevalence and correlates. It was hypothesized that children with PDD plus manic features have both disorders. METHOD: Subjects were consecutively referred children meeting diagnostic criteria on structured interview for PDD without mania (n = 52), the comorbid condition PDD + mania (n = 14), and mania without PDD (n = 114). All subjects were evaluated using a comprehensive diagnostic battery that included assessment of psychopathology (structured diagnostic interview and Child Behavior Checklist), cognition, and functioning. RESULTS: Of the 727 referred children, 52 met criteria for PDD, 114 met criteria for mania, and 14 met criteria for both. The 14 children with both PDD + mania represented 21% of the PDD subjects and 11% of all manic subjects. Clinical characteristics of PDD were similar in PDD subjects with and without mania, and manic features were similar in manic children with and without PDD. CONCLUSIONS: Children with PDD and mania may suffer from two disorders. Comorbid mania among patients with PDD may be more common than previously thought. Identification of the comorbid condition may have important therapeutic and scientific implications.

Bipolar Disorder↗
PubMed1995

Complex and rapid-cycling in bipolar children and adolescents: a preliminary study.

26 subjects aged 7-18 years were studied. Diagnoses of bipolar disorders were established using the Kiddie-Schedule for Affective Disorders and Schizophrenia-Present Episode Version-1986 modified for DSM-III-R criteria and for rating the number and duration of manic and hypomanic episodes. Complex cycling patterns were observed. These included numerous brief episodes suggesting continuous rapid-cycling in 80.8% of cases. Mean age of onset was early (8.5 +/- 4.4 years). Psychotic phenomena, suicidality, hyperactivity and 'mixed mania' were highly prevalent. Data in this report provide support for complex and rapid-cycling patterns in childhood onset bipolar disorder.

Adolescent↗
PubMed1994

Strategic considerations for capital formation and development.

It is the role of healthcare financial managers to maximize their organizations' return on equity, not only for the short term, but also with an eye to the future. This article explores the financial and managerial factors financial managers should consider when planning the strategic sources of capital funds and asset acquisitions for an organization, then examines the factors comprising return on equity-margin, leverage, and turnover-in light of current and projected industry trends.

Capital Financing↗
PubMed1993

A novel DNA duplex. A parallel-stranded DNA helix with Hoogsteen base pairing.

We show here for the first time that a stable parallel double helix with Hoogsteen pairing can exist independently of the triple helix of which it is a component part. The experiments employ DNA oligonucleotides with mixed sequences of normal bases. These duplexes are distinct from previously reported ribopolynucleotide helices containing bulky substituents which prevent Watson-Crick pairing as well as from parallel duplexes with Donohue, or reversed Watson-Crick, pairing. Stoichiometry is established by mixing curves and gel electrophoresis. Tm depends linearly upon pH, increasing with acidity because of the need to protonate N3 of C. The Tm of the 20-mer studied here is 52 degrees C at pH 5.2 and 0.1 M NaCl. At pH above 6, the molecule rearranges to form an antiparallel duplex with imperfect Watson-Crick pairing and loops, and the Tm is then independent of pH. The CD spectrum of the parallel duplex is very similar to that of the corresponding triple helix but quite different from that of the Watson-Crick helix. The infrared spectrum in the double bond region closely resembles that of the triple helix but, as with the CD, is quite different from that of the Watson-Crick duplex. The infrared spectra of the duplex and triple helix are also nearly identical in the region form 800 to 1000 cm-1, which is sensitive to backbone conformation. The only symmetry element present is a pseudorotational axis coincident with the helix axis of the parallel duplex as well as with the axis of the corresponding triple helix.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Composition↗
PubMed1993

Fowlpox virus host range restriction: gene expression, DNA replication, and morphogenesis in nonpermissive mammalian cells.

Fowlpox virus (FPV), type species of the Avipoxvirus genus, causes a slow-spreading pox disease of chickens. Following infection of mammalian cells there is no evidence of productive replication of FPV although cytopathic effects are induced and FPV recombinants have been shown to express foreign genes from vaccinia virus early/late promoters. Here we report results of a study to investigate the expression of FPV genes, the replication of FPV genomic DNA, and any ultrastructural changes in mammalian cells infected by wild-type virus, undertaken as a first step in elucidating the nature of the block (or blocks) to productive replication of FPV in mammalian cells. Early and late gene expression as well as genomic DNA replication was observed in fibroblast-like cell lines of monkey and human origin. Furthermore, viral morphogenesis was observed in monkey cells, with the production mainly of immature particles though smaller numbers of apparently mature virus particles were observed.

Animals↗
PubMed1993

Extended survival and function of peripheral nerve allografts after cessation of long-term cyclosporin administration in rats.

To determine whether survival and function of peripheral nerve allografts are possible after cessation of long-term cyclosporin (CsA) treatment, we grafted 4.25 cm Lewis rat peripheral nerve allografts (n = 22) into tibial nerve gaps in recipient brown Norway rats. Allograft groups received CsA (15 mg/kg) subcutaneously every day for 20 days and then biweekly for either 5 or 8 months after transplantation. The control group, brown Norway rats with isografts from brown Norway donor rats (n = 2), also received identical CsA treatment. Semimonthly electrophysiologic studies were done from postoperative week 13 until the animals were killed (up to 79 weeks). The corresponding CsA levels in the nerve and blood were recorded from cessation of CsA up to 58 weeks after surgery. No electrophysiologic signs of rejection were observed in any of the 22 allograft recipients treated with CsA for up to 8 months or in 17 of the 22 observed for up to 58 weeks after cessation of CsA. Overall, 5 of 22 allografts were rejected in the first 8 weeks after discontinuation of CsA. Signs of rejection occurred only in the 5-month treatment group and followed the large initial drop in CsA blood level (from 1010 ng/ml to < 25 ng/ml) that occurred within the first 6 weeks after CsA cessation. The two isograft controls demonstrated no electrophysiologic signs of rejection up to 58 weeks after surgery. Peripheral nerve allografts in the rat can regenerate and function on long-term CsA; after cessation of CsA, they can function for extended periods of time without signs of rejection if trace amounts of CsA are present.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1992

Structure of d(T)n.d(A)n.d(T)n: the DNA triple helix has B-form geometry with C2'-endo sugar pucker.

The polynucleotide helix d(T)n.d(A)n.d(T)n is the only deoxypolynucleotide triple helix for which a structure has been published, and it is generally assumed as the structural basis for studies of DNA triplexes. The helix has been assigned to an A-form conformation with C3'-endo sugar pucker by Arnott and Selsing [1974; cf. Arnott et al. (1976)]. We show here by infrared spectroscopy in D2O solution that the helix is instead B-form and that the sugar pucker is in the C2'-endo region. Distamycin A, which binds only to B-form and not to A-form helices, binds to the triple helix without displacement of the third strand, as demonstrated by CD spectroscopy and gel electrophoresis. Molecular modeling shows that a stereochemically satisfactory structure can be build using C2'-endo sugars and a displacement of the Watson-Crick base-pair center from the helix axis of 2.5 A. Helical constraints of rise per residue (h = 3.26 A) and residues per turn (n = 12) were taken from fiber diffraction experiments of Arnott and Selsing (1974). The conformational torsion angles are in the standard B-form range, and there are no short contacts. In contrast, we were unable to construct a stereochemically allowed model with A-form geometry and C3'-endo sugars. Arnott et al. (1976) observed that their model had short contacts (e.g., 2.3 A between the phosphate-dependent oxygen on the A strand and O2 in the Hoogsteen-paired thymine strand) which are generally known to be outside the allowed range.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemical Phenomena↗