Toxicologic effects of a novel acyl-CoA:cholesterol acyltransferase inhibitor in cynomolgus monkeys.

PD 132301-2, an acyl-CoA: cholesterol acyltransferase (ACAT) inhibitor, was administered orally to cynomolgus monkeys for 2 wk at doses of 25, 50, 100, and 200 mg/kg to assess potential subacute toxicity. Sporadic episodes of soft feces and diarrhea increased in incidence from 100 to 200 mg/kg. Histopathologic alterations in adrenocortical cells of treated monkeys consisted of a dose-related decrease in cytoplasmic fine vacuolation and an increase in cytoplasmic eosinophilia most conspicuous in the zona fasciculata and reticularis.

Genetic typing of patients with inflammatory arthritis at presentation can be used to predict outcome.

Objective: To test the hypothesis that genetic characterization of patients at the time they present with inflammatory arthritis can predict subsequent destructive disease.

Methods: We evaluated 177 patients with early arthritis. Patients were serologically tested for rheumatoid factor (RF) and were DNA oligotyped for the presence of conserved base sequences in the third hypervariable region (HVR3) of the DRB1 gene, previously shown to be associated with severe rheumatoid arthritis (RA).

Generalised bone loss in patients with early rheumatoid arthritis.

Generalised osteoporosis is a feature of established rheumatoid arthritis but whether this is a consequence of treatment, immobility, or disease activity has been unclear. We estimated bone mineral density by dual energy x-ray absorptiometry on 148 patients with early rheumatoid arthritis before treatment with corticosteroids or disease-modifying drugs and 730 normal controls. Scans were done at 12-month intervals in patients and at 0 and 12 months on 50 of the controls matched for menopausal status.

Sulfate metabolism is abnormal in patients with rheumatoid arthritis. Confirmation by in vivo biochemical findings.

Objective: To independently confirm previous probe drug findings that patients with rheumatoid arthritis (RA) have defective oxidation of cysteine derivatives.

Methods: Measurement of cysteine dioxygenase substrate (cysteine) and product (sulfate) under controlled conditions, with elemental assessment by proton induced x-ray emission (PIXE).

Results: Plasma inorganic sulfate was significantly depressed in patients with rheumatoid arthritis (RA) compared to both controls and non-RA disease, 85 +/- 36 nm/ml vs 267 +/- 146 and 604 +/- 412 (mean +/- SD.

Chromosome assignment of the human glutathione S-transferase mu 3 gene (GSTM3) to chromosome 1 by gene specific polymerase chain reaction.

Oligonucleotide primers specific for exons 4 and 5 sequences were used to amplify a unique 199-bp fragment in the human GSTM3 gene. Using DNA from a panel of somatic cell hybrids we assigned the GSTM3 locus to chromosome 1p.

Excretion of pyridinium crosslinks correlates with disease activity and appendicular bone loss in early rheumatoid arthritis.

Objective: To establish if urinary excretion rates of the collagen crosslinks pyridinoline and deoxypyridinoline, which are known to be elevated in established rheumatoid arthritis (RA), are useful markers of bone loss in this disease.

Methods: Eight hour urine collections on all patients and 52 controls were performed, and the rates of pyridinoline and deoxypyridinoline excretion were measured. Bone mineral density (BMD), by dual energy x-ray absorption, and full laboratory and clinical assessments were performed.

Adverse interaction between intramuscular methylprednisolone and sulphasalazine in patients with early rheumatoid arthritis. A pilot study.

A defective hypothalamic-pituitary-adrenal axis has been associated with susceptibility to arthritis in rats and with rheumatoid arthritis in humans. The effect of corticosteroid supplementation in early RA has not been tested previously. We undertook a double-blind placebo-controlled study of sulphasalazine plus either corticosteroid or placebo.

Immunopathologic characterization of typhlitis and colitis in juvenile HLA-B27 transgenic rats.

Adult HLA-B27 transgenic rats carrying high copy numbers of human HLA-B27 and beta 2-microglobulin genes spontaneously develop spondyloarthropathy and enterocolitis comparable to human HLA-B27-associated disease. In this investigation, juvenile HLA-27 transgenic rats were utilized to study incipient immunopathologic events in HLA-B27-associated gastrointestinal inflammation. Flow cytometric analysis of peripheral lymphocytes demonstrated distinctive differences in HLA-B27 protein expression and prompted the division of these transgenic rodents into 2 groups: HLA-B27hi and HLA-B27lo.

Toxicity of CI-949, a novel anti-allergy agent.

The toxicity of CI-949, an effective inhibitor of allergic mediator release in pharmacology models, was evaluated in rodents and dogs. Median lethal doses at 24-hr postdose ranged from 343 to 453 mg/kg in mice and 806 to 2058 mg/kg in rats. Delayed toxicity was observed at 300 mg/kg and greater in mice and at 500 mg/kg and greater in rats.

Fluorescence anisotropy imaging microscopy maps calmodulin binding during cellular contraction and locomotion.

Calmodulin is a calcium transducer that activates key regulatory and structural proteins through calcium-induced binding to the target proteins. A fluorescent analog of calmodulin in conjunction with ratio imaging, relative to a volume indicator, has demonstrated that calmodulin is uniformly distributed in serum-deprived fibroblasts and there is no immediate change in the distribution upon stimulation with complete serum. The same fluorescent analog of calmodulin together with steady state fluorescence anisotropy imaging microscopy has been used to define the temporal and spatial changes in calmodulin binding to cellular targets during stimulation of serum-deprived fibroblasts and in polarized fibroblasts during wound healing.

Pelvic insufficiency fractures in rheumatoid arthritis.

The occurrence of pelvic insufficiency fractures in patients with rheumatoid arthritis has not previously been well emphasized. These fractures are difficult to detect clinically and appropriate radiological investigation is necessary for diagnosis. We describe five patients with a spectrum of radiological features and discuss the approach to diagnosis and treatment of these lesions.

Localization of the CYP2D gene locus to human chromosome 22q13.1 by polymerase chain reaction, in situ hybridization, and linkage analysis.

Using a combination of somatic cell hybrids, in situ hybridization, and linkage mapping, we have been able to localize the cytochrome P450 CYP2D6 gene to chromosome 22 in the region q13.1. Linkage analysis, using locus-specific primers, showed a maximum sex-average lod score of 8.

Subacute toxicity of a novel inhibitor of acyl-CoA: cholesterol acyltransferase in beagle dogs.

PD 132301-2 is a substituted urea hypolipidemic and antiatherosclerotic agent that is a potent inhibitor of acyl-CoA:cholesterol acyltransferase (ACAT). To determine its subacute toxicity, PD 132301-2 was administered orally to beagle dogs at 0, 6, 12, 25, 50, 200, 400, or 800 mg/kg/day for 2 weeks. Clinico-pathologic evaluations were completed on all dogs.

Morphogenesis of a zone-specific adrenocortical cytotoxicity in guinea pigs administered PD 132301-2, an inhibitor of acyl-CoA:cholesterol acyltransferase.

PD 132301-2, a novel inhibitor of acyl-CoA:cholesterol acyltransferase, is adrenotoxic to several laboratory animal species. Morphogenesis of a zona fasciculata-specific cytotoxicity was evaluated in male Hartley guinea pigs administered 100 mg/kg of PD 132301-2 for up to 7 days. Reversibility of adrenal effects was assessed after a 14-day drug withdrawal period (day 21).

Molecular genetic analysis of the cytochrome P450-debrisoquine hydroxylase locus and association with cancer susceptibility.

The cytochrome P450-dependent monooxygenases play a central role in the metabolism of chemical carcinogens. The action of these enzymes can lead to either carcinogen detoxication or activation. Differences in P450 expression in animal models give rise to large differences in susceptibility to chemical carcinogens, so genetic polymorphisms in P450 expression may be expected to be an important factor in individual human susceptibility to cancer.

Molecular genetics of the human cytochrome P450-dependent monooxygenases.

In this work, the role of genetic as well as environmental factors in determining cytochrome P450 isozyme levels in man have been studied. Simple DNA based assays for the identification of individuals nulled at the CYP2D6 locus are described and have been applied to investigate whether this gene defect is associated with altered cancer susceptibility. In contrast to literature reports, in no cancer type were poor metabolizers underrepresented, indeed in several cancers the mutant allele frequency was increased.

Debrisoquine hydroxylase gene polymorphism and susceptibility to Parkinson's disease.

The pathogenesis of Parkinson's disease may be influenced by genetic and environmental factors. Cytochrome P450 mono-oxygenases help to protect against toxic environmental compounds and individual variations in cytochrome P450 expression might, therefore, influence susceptibility to environmentally linked diseases. The frequency of mutant CYP2D6 alleles was studied in 229 patients with Parkinson's disease and 720 controls.

Relationship between the debrisoquine hydroxylase polymorphism and cancer susceptibility.

There have been a series of reports on the association of a genetic polymorphism at the cytochrome P450 CYP2D6 gene locus with cancer susceptibility. Many of these reports have remained contradictory either because of small numbers of patients studied or because of the limitations and controversy surrounding the pharmacokinetic assay used to identify affected individuals (poor metabolizers; PMs). We have recently developed a DNA-based assay that will allow the unequivocal identification of poor metabolizers and have applied this to the study of 1635 patients with different forms of cancer.

Increased prevalence of poor sulphoxidation in patients with rheumatoid arthritis: effect of changes in the acute phase response and second line drug treatment.

A minority of normal subjects have an impaired ability to oxidise sulphur, which is associated with an increased risk of side effects when they receive sulphur containing drugs. In 114 patients with rheumatoid arthritis a greatly increased prevalence of poor sulphoxidation was found in 82 (72%) patients compared with 70/200 (35%) healthy controls, 45/121 (37%) controls matched for age, and 4/35 (11%) of the normal aged general population. In a longitudinal study of 37 patients there was no significant alteration in sulphoxidation status after the introduction of a second line drug or with marked changes in the acute phase response.

Calcium valproate-induced uterine adenocarcinomas in Wistar rats.

Calcium valproate is an anticonvulsant agent with pharmacokinetic properties similar to sodium valproate and valproic acid. Potential carcinogenesis of calcium valproate was evaluated in B6C3F1 mice and Wistar rats given 125, 250 and 500 mg/kg in the diet for 104 weeks. Survival in treated rats increased in a dose-related pattern despite a tumorigenic response in females.