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Biomedical subjects

R Pedersen

Publications and source records attributed to R Pedersen.

At least 19 recordsLinked to original sources

Efficacy and safety of combination etanercept and methotrexate versus etanercept alone in patients with rheumatoid arthritis with an inadequate response to methotrexate: the ADORE study.

OBJECTIVE: To evaluate the efficacy and safety of etanercept (ETN) monotherapy compared with combination ETN and methotrexate (MTX) treatment in patients with rheumatoid arthritis who had an inadequate response to MTX monotherapy. (The response was defined by the presence of Disease Activity Score-28 joint count (DAS28) >or=3.2 or a combination of >or=5 swollen joints, >or=5 painful joints and erythrocyte sedimentation rate >or=10 mm/h.) METHODS: Patients with active rheumatoid arthritis taking MTX >or=12.5 mg/week for >or=3 months were included in this 16 week, randomised, open-label study. Patients were randomly assigned to either ETN (25 mg subcutaneous injection twice weekly) added to the baseline dose of MTX or ETN monotherapy. RESULTS: 315 patients were randomised to ETN (n = 160) or ETN plus MTX (n = 155). The primary end point, DAS28 (4) improvement of >1.2 units, was achieved by 72.8% and 75.2% of patients treated with ETN and those treated with ETN plus MTX, respectively, with no significant difference (p = 0.658) between the two groups. The European League Against Rheumatism response criteria of good or moderate response was attained by 80.0% of patients in the ETN group and by 82.4% of patients in the ETN plus MTX group. American College of Rheumatology 20%, 50% and 70% response rates achieved by both groups were also similar: 71.0% v 67.1%, 41.9% v 40.1% and 17.4% v 18.4%, respectively. The rates of adverse and serious adverse events were similar between the treatment groups. CONCLUSION: Both the addition of ETN to MTX and the substitution of ETN for MTX in patients with rheumatoid arthritis who had an inadequate response to MTX resulted in substantial improvements in clinical signs and symptoms and were generally well-tolerated treatment strategies for improving clinical signs and symptoms of rheumatoid arthritis.

Adult↗

Retinal vessel dilation following repletion of vitamin A deficiency.

We hypothesized that because depletion of vitamin A blocks the initiation of phototransduction, such inhibition of functional activation should lead to decrease retinal metabolism and perfusion. In a case study of a vitamin A-depleted patient, we found that retinal vessel diameters, a surrogate measure of retinal perfusion, increased in concert with the restitution of electroretinographic function following vitamin A supplementation. When normalized to conditions after treatment, the relative magnitude of study parameters at presentation were: scotopic electroretinography B-wave amplitude 1.2%, photopic electroretrinography B-wave amplitude 23%, retinal vein diameter 88%, retinal artery diameter 94%. These observations support that activation of the visual process results in increased retinal metabolism and perfusion.

Adult↗

Patient reported outcomes in a trial of combination therapy with etanercept and methotrexate for rheumatoid arthritis: the TEMPO trial.

OBJECTIVE: To compare patient reported measures of function, health related quality of life (QoL), and satisfaction with medication among patients with rheumatoid arthritis (RA) treated with methotrexate (MTX), etanercept, or both for up to 1 year. METHODS: In a 52 week, double blind, clinical trial, patients with active RA were randomised to receive etanercept 25 mg twice weekly, methotrexate up to 20 mg weekly, or combination therapy. The Health Assessment Questionnaire (HAQ) disability index, EuroQoL health status visual analogue scale (EQ-5D VAS), patient global assessment, and patient general health VAS were administered at baseline and weeks 2, 4, 8, 12, 16, 20, 24, 32, 40, 48, and 52. Satisfaction with the medication was compared at 52 weeks. RESULTS: Of 682 enrolled patients, 522 completed 52 weeks of treatment. Mean improvement from baseline in HAQ score was 0.65, 0.70, and 1.0 for MTX, etanercept, and the combination, respectively. The mean percentage and absolute improvement in the HAQ was significantly higher (p<0.01) for combination therapy than for either of the monotherapies. Combination therapy produced significantly more rapid achievement of HAQ < or =0.5 sustained for 6 months than either of the monotherapies (p<0.01). Compared with patients receiving monotherapy, those receiving combination therapy achieved a significantly better (p<0.05) health state as measured by the EQ-5D VAS (mean (SD) 63.7 (3.2), 66.8 (3.2), 72.7 (3.1) for MTX, etanercept, and the combination, respectively). Results were similar for other assessments (p<0.01). Patients in combination and etanercept groups were significantly more likely (p<0.0001, p = 0.0009, respectively) to report satisfaction with the medication. CONCLUSIONS: Combination therapy with etanercept and methotrexate improved function, QoL, and satisfaction with the medication significantly more than monotherapy.

Adult↗

Comparison of different definitions to classify remission and sustained remission: 1 year TEMPO results.

OBJECTIVE: To assess methods to calculate achieving and sustaining remission in a double blind randomised trial in patients with RA who received etanercept, methotrexate, or an etanercept/methotrexate combination. METHODS: Remission was defined as DAS <1.6, DAS28 <2.6, and ACR70 response. Sustaining remission was analysed in three ways: (a) analysis of sustained DAS remission, DAS28 remission, or ACR70 response continuously for 6 months; (b) analysis of sustained remission appraised through a continuity rewarded scoring system, which is the weighted sum of all intervals in the study in which patients are in DAS or DAS28 remission; or (c) longitudinal modelling of remission odds using generalised estimating equations. RESULTS: Significantly more patients treated with the etanercept/methotrexate combination reached DAS remission (37%) than those treated with either methotrexate (14%) or etanercept (18%) alone (p<0.01). Results for DAS28 and for the ACR70 response were similar. Agreement between DAS remission and DAS28 remission was good, but agreement between either of these and the ACR70 response was less. Patients in DAS or DAS28 remission had a lower level of disease activity (fewer active joints, lower ESR) than those achieving ACR70 response; the converse was seen using pain VAS. The three methods were comparable for sustainability of remission and showed significant advantage for combination therapy, which increased the number and durability of remission periods. CONCLUSIONS: DAS and DAS28 remission results were similar for assessing achieving and sustaining remission in RA, frequently differing from patients classified as ACR70 responders. The three methods of examining duration of remission produced comparable results.

Adult↗

Computed tomography of the urinary tract: optimalization of low-dose stone protocol in a clinical setting.

PURPOSE: To establish whether information would be lost if slice reconstruction thickness was increased from 3 to 5 mm, and whether this altered how difficult it was to interpret the examinations. MATERIAL AND METHODS: Twenty-three consecutive patients referred with suspected or known urinary stones were included. All examinations were performed without intravenous contrast media. The original series, with effective mAs 50, were reconstructed with slice thickness 3 and 5 mm, respectively. All demographic and examination data were removed and the series reviewed in PACS by two independent radiologists. Objective findings, i.e. number and size of stones, signs of obstruction, and evaluation of interpretation difficulty, were registered. RESULTS: Identical findings were registered in 18 of the series of 3 mm (n=23) and 19 of the series of 5 mm (n=23). In two series reconstructed with 3 mm slice thickness and in one series with 5 mm slice thickness, the observers disagreed on the presence of urinary stones. Main reasons for interpretation difficulties were given as "lack of intra-abdominal fat" and "many phleboliths in the pelvic region", but never "disturbing noise". CONCLUSION: To determine the presence and size of urinary stones at low-dose computed tomography, 5 mm reconstruction algorithm seems equal to 3 mm. Patient-related factors influence the interpretation more than image quality.

Adult↗

Mice lacking Dad1, the defender against apoptotic death-1, express abnormal N-linked glycoproteins and undergo increased embryonic apoptosis.

Dad1 has been shown to play a role in preventing apoptotic cell death and in regulating levels of N-linked glycosylation in Saccharomyces cerevisiae and the BHK hamster cell line. To address the in vivo role of Dad1 in these processes during multicellular development, we have analyzed mice carrying a null allele for Dad1. Embryos homozygous for this mutation express abnormal N-glycosylated proteins and are developmentally delayed by embryonic day 7.5. Such mutants exhibit aberrant morphology, impaired mesodermal development, and increased levels of apoptosis in specific tissues. These defects culminate in homozygous embryos failing to turn the posterior axis and subsequent lethality by embryonic day 10.5. Thus, Dad1 is required for proper processing of N-linked glycoproteins and for certain cell survival in the mouse.

Animals↗

The effect of passing an "anti-immigrant" ballot proposition on the use of prenatal care by foreign-born mothers in California.

This study examines whether the passage of California's Proposition 187, a proposition designed to restrict undocumented immigrants from using public services, had a negative effect on the use of prenatal care and birth outcomes. Comparisons of prenatal care use and birth outcomes before and after the passage of the proposition are made between low-education foreign-born and U.S.-born mothers using California's Birth Public Use files. Multivariate linear and logistic regressions were used to control for regional and maternal characteristics. We find a significant but small decline in the use of prenatal care by low-education foreign-born women after Proposition 187 passed; however, there was no detectable deterioration of birth outcomes. Whether future reductions in the availability of prenatal care would damage the health of children is unclear.

Journal Article↗

[How can we justify scientific research?].

The purpose and goal of scientific research have always been of concern to philosophers and ethicists. This concern is closely linked to the values that have justified scientific research. This paper takes a closer look at these values: professional personal fulfillment, social utility, and methodological norms such as value neutrality, openness and autonomy. These values originated in different historical epochs; however, they are still of great importance, e.g. in setting research priorities.

Ethics, Medical↗

Centromeric protein B null mice are viable with no apparent abnormalities.

The centromere protein B (CENP-B) is a centromeric DNA/binding protein. It recognizes a 17-bp sequence motif called the CENP-B box, which is found in the centromeric region of most chromosomes. It binds DNA through its amino terminus and dimerizes through its carboxy terminus. CENP-B protein has been proposed to perform a vital role in organizing chromatin structures at centromeres. However, other evidence does not agree with this view. For example, CENP-B is found at inactive centromeres on stable dicentric chromosomes, and also mitotically stable chromosomes lacking alpha-satellite DNA have been reported. To address the biological function of CENP-B, we generated mouse null mutants of CENP-B by homologous recombination. Mice lacking CENP-B were viable and fertile, indicating that mice without CENP-B undergo normal somatic and germline development. Thus, both mitosis and meiosis are able to proceed normally in the absence of CENP-B.

Animals↗

An olfactory sensory map develops in the absence of normal projection neurons or GABAergic interneurons.

Olfactory sensory neurons expressing a given odorant receptor project to two topographically fixed glomeruli in the olfactory bulb. We have examined the contribution of different cell types in the olfactory bulb to the establishment of this topographic map. Mice with a homozygous deficiency in Tbr-1 lack most projection neurons, whereas mice with a homozygous deficiency in Dlx-1 and Dlx-2 lack most GABAergic interneurons. Mice bearing a P2-IRES-tau-lacZ allele and deficient in either Tbr-1 or Dlx-1/Dlx-2 reveal the convergence of axons to one medial and one lateral site at positions analogous to those observed in wild-type mice. These observations suggest that the establishment of a topographic map is not dependent upon cues provided by, or synapse formation with, the major neuronal cell types in the olfactory bulb.

Animals↗

Mutations of the homeobox genes Dlx-1 and Dlx-2 disrupt the striatal subventricular zone and differentiation of late born striatal neurons.

The striatum has a central role in many neurobiological processes, yet little is known about the molecular control of its development. Inroads to this subject have been made, due to the discovery of transcription factors, such as the Dlx genes, whose expression patterns suggest that they have a role in striatal development. We report that mice lacking both Dlx-1 and Dlx-2 have a time-dependent block in striatal differentiation. In these mutants, early born neurons migrate into a striatum-like region, which is enriched for markers of the striosome (patch) compartment. However, later born neurons accumulate within the proliferative zone. Several lines of evidence suggest that mutations in Dlx-1 and Dlx-2 produce abnormalities in the development of the striatal subventricular zone and in the differentiation of striatal matrix neurons.

Animals↗

Inactivation of mouse alpha-globin gene by homologous recombination: mouse model of hemoglobin H disease.

We have disrupted the 5' locus of the duplicated adult alpha-globin genes by gene targeting in the mouse embryonic stem cells and created mice with alpha-thalassemia syndromes. The heterozygous knockout mice (.alpha/alpha alpha) are asymptomatic like the silent carriers in humans whereas the homozygous knockout mice (.alpha/.alpha) show hemolytic anemia. Mice with three dysfunctional alpha-globin genes generated by breeding the 5' alpha-globin knockouts (.alpha/alpha alpha) and the deletion type alpha-thalassemia mice (../alpha alpha) produce severe hemoglobin H disease and they die in utero. These results indicate that the 5' alpha-globin gene is the predominant locus in mice, and suggest that it is even more dominant than its human homologue.

Animals↗

Structure-activity relationships of analogues of thapsigargin modified at O-11 and O-12.

A number of analogues of thapsigargin have been synthesized by alkylating or acylating O-11 and O-12 in the lactol obtained by reducing thapsigargicin. Introduction of alpha-disposed substituents decreased the Ca(2+)-ATPase inhibitory potency of the analogue, whereas the enzyme was more tolerant toward beta-disposed substituents, indicating that the alpha-face of the lactone ring is in close contact with the binding site when the inhibitor is bound to the enzyme.

Animals↗

[Colonoscopy. In investigation, treatment and control of gastrointestinal diseases].

Colonoscopy is the initial examination for patients with manifest or occult rectal bleeding, inflammatory bowel disease and colorectal polyps. In addition to polypectomy, colonoscopy is useful in decompression of adynamic colonileus and laser palliation of intractable tumours. In adenoma patients controls should be limited to high risk patients, i.e. those with large and multiple tubular adenomas, villous adenomas, multiple hyperplastic polyps (> 30), and first degree relatives of patients with colorectal carcinomas. Control after radical surgical treatment of colorectal cancer is offered during the first two years after the operation and to persons younger than 40 years. The efficacy of control programmes for hereditary nonpolyposis colorectal cancer families have to be evaluated in controlled series. Rectosigmoidoscopies could probably replace some total colonoscopies to examine ulcerative colitis patients for cancer, since cancer usually occurs in the distal colon. Complications are rare after diagnostic and therapeutic colonoscopies, but perforation, bleeding and injury to surrounding organs can be experienced.

Colonoscopy↗

Targeted disruption within the CD3 zeta/eta/phi/Oct-1 locus in mouse.

To elucidate the role of the CD3 eta subunit of the T cell receptor (TCR) in thymic development, a CD3 eta -/- mouse was generated by gene targeting. Insertion of a neomycin resistance gene into exon 9 of the CD3 zeta/eta/phi locus disrupted expression of CD3 eta and CD3 phi without affecting the expression of CD3 zeta. Little difference was observed between wild type and CD3 eta -/- mice with regard to cellularity or subset composition in thymus and peripheral lymphoid organs. Furthermore, neither alloproliferative responses nor cytotoxic T lymphocyte generation and effector function was affected by the mutation. The effect of the CD3 eta -/- mutation on thymic selection was examined by crossing the CD3 eta knockout animals with anti-HY TCR transgenic animals: the absence of the CD3 eta subunit altered neither positive nor negative selection. Thus, CD3 eta is not required for thymic selection. Of note, the birth rate of the CD3 eta -/- animals was significantly lower than that of wild type or heterozygous animals (P = 0.041-0.002). This unexpected result is probably the consequence of an alteration in mRNA expression of the Oct-1 nuclear transcription factor in CD3 eta -/- animals. The CD3 zeta/eta/phi locus partially overlaps the gene encoding Oct-1 whose transcription is dysregulated by the CD3 eta -/- mutation. Our results clearly underscore the value of characterizing all products of a genetic locus disrupted by gene targeting.

Alleles↗

The gene encoding the periplasmic cyclophilin homologue, PPIase A, in Escherichia coli, is expressed from four promoters, three of which are activated by the cAMP-CRP complex and negatively regulated by the CytR repressor.

The rot gene in Escherichia coli encodes PPIase A, a periplasmic peptidyl-prolyl cis-trans isomerase with homology to the cyclophilin family of proteins. Here it is demonstrated that rot is expressed in a complex manner from four overlapping promoters and that the rot regulatory region is unusually compact, containing a close array of sites for DNA-binding proteins. The three most upstream rot promoters are activated by the global gene regulatory cAMP-CRP complex and negatively regulated by the CytR repressor protein. Activation of these three promoters occurs by binding of cAMP-CRP to two sites separated by 53 bp. Moreover, one of the cAMP-CRP complexes is involved in the activation of both a Class I and a Class II promoter. Repression takes place by the formation of a CytR/cAMP-CRP/DNA nucleoprotein complex consisting of the two cAMP-CRP molecules and CytR bound in between. The two regulators bind co-operatively to the DNA overlapping the three upstream promoters, simultaneously quenching the cAMP-CRP activator function. These results expand the CytR regulon to include a gene whose product has no known function in ribo- and deoxyribonucleoside catabolism or transport.

Amino Acid Isomerases↗