The Cutaneous Assessment Tool: development and reliability in juvenile idiopathic inflammatory myopathy.

OBJECTIVES: Clinical care and therapeutic trials in idiopathic inflammatory myopathies (IIM) require accurate and consistent assessment of cutaneous involvement. The Cutaneous Assessment Tool (CAT) was designed to measure skin activity and damage in IIM. We describe the development and inter-rater reliability of the CAT, and the frequency of lesions endorsed in a large population of juvenile IIM patients. METHODS: The CAT includes 10 activity, 4 damage and 7 combined lesions. Thirty-two photographic slides depicting IIM skin lesions were assessed by 11 raters. One hundred and twenty-three children were assessed by 11 paediatric rheumatologists at 10 centres. Inter-rater reliability was assessed using simple agreements and intra-class correlation coefficients (ICC). RESULTS: Simple agreements in recognizing lesions as present or absent were generally high (0.5-1.0). ICCs for CAT lesions were moderate (0.4-0.75) in both slides and real patients. ICCs for the CAT activity and damage scores were 0.71 and 0.81, respectively. CAT activity scores ranged from 0 to 44 (median 7, potential range 0-96) and CAT damage scores ranged from 0 to 13 (median 1, potential range 0-22). The most common cutaneous lesions endorsed were periungual capillary loop changes (63%), Gottron's papules/sign (53%), heliotrope rash (49%) and malar/facial erythema (49%). CONCLUSIONS: Total CAT activity and damage scores have moderate to good reliability. Assessors generally agree on the presence of a variety of cutaneous lesions. The CAT is a promising, semi-quantitative tool to comprehensively assess skin disease activity and damage in IIM.

The effect of C/N ratio on ammonia oxidising bacteria community structure in a laboratory nitrification-denitrification reactor.

A laboratory scale reactor operated as a single sludge, denitrification-nitrification bioreactor (DNB), was fed a synthetic wastewater. The effect of the C/N ratio of the influent on the structure of beta-proteobacterial autotrophic ammonia-oxidizing bacterial (AOB) communities was determined by DGGE analysis of 16S rRNA gene fragments amplified using a range of AOB-selective primers. Fluorescence in situ hybridisation (FISH) was used to determine quantitative changes in the AOB communities. When operated at a C/N ratio of 2 the DNB was effective in nitrogen removal and nitrification was measured at approximately 1.0 mg NH4+-N/g dry wt/h. Altering the C/N ratio to 5 resulted in a 50% reduction in nitrification rates. Nitrification was restored to its original level when the C/N ratio was returned to 2. AOB were detected by DGGE analysis of samples from the DNB under all operating conditions but the changes in C/N ratio and nitrification rates were accompanied by changes in the community structure of the AOB. However, quantitative FISH analysis indicated that beta-proteobacterial AOB were only present in high numbers (ca. 10(8) cells/ml) under the original operating conditions with a C/N ratio of 2. Beta-proteobacterial AOB could not be detected by FISH when the C/N ratio was 5. When nitrification activity was restored by returning the C/N ratio to 2, beta-proteobacterial AOB were still not detected and it is likely that either beta-proteobacterial AOB were not responsible for ammonia oxidation or that beta-proteobacterial AOB that did not contain the target sites for the range of 4 AOB selective probes used, were present in the reactor.

Aging, oxidative responses, and proliferative capacity in cultured mouse aortic smooth muscle cells.

The cellular mechanisms that contribute to the acceleration of atherosclerosis in aging populations are poorly understood, although it is hypothesized that changes in the proliferative capacity of vascular smooth muscle cells is contributory. We addressed the relationship among aging, generation of reactive oxygen species (ROS), and proliferation in primary culture smooth muscle cells (SMC) derived from the aortas of young (4 mo old) and aged (16 mo old) mice to understand the phenotypic modulation of these cells as aging occurs. SMC from aged mice had decreased proliferative capacity in response to alpha-thrombin stimulation, yet generated higher levels of ROS and had constitutively increased mitogen-activated protein kinase activity, in comparison with cells from younger mice. These effects may be explained by dysregulation of cell cycle-associated proteins such as cyclin D1 and p27Kip1 in SMC from aged mice. Increased ROS generation was associated with decreased endogenous antioxidant activity, increased lipid peroxidation, and mitochondrial DNA damage. Accrual of oxidant-induced damage and decreased proliferative capacity in SMC may explain, in part, the age-associated transition to plaque instability in humans with atherosclerosis.

Validation of the Childhood Health Assessment Questionnaire in the juvenile idiopathic myopathies. Juvenile Dermatomyositis Disease Activity Collaborative Study Group.

OBJECTIVE: To examine the validity of the Childhood Health Assessment Questionnaire (CHAQ) in patients with juvenile idiopathic inflammatory myopathy (IIM). METHODS: One hundred fifteen patients were enrolled in a multicenter collaborative study, during which subjects were assessed twice, 7-9 months apart. Physical function was measured using the CHAQ. Internal reliability was assessed using adjusted item-total correlations and item endorsement rates. Construct validity was assessed by comparing predicted and actual correlations of the CHAQ with other measures of physical function and disease activity. Responsiveness was assessed by calculating effect size (ES) and standardized response mean (SRM) in a group of a priori defined "improvers." RESULTS: Item-total correlations were high (rs range = 0.35-0.81), suggesting all items were related to overall physical function. Manual muscle testing and the Childhood Myositis Assessment Scale correlated moderate to strongly with the CHAQ (r = -0.64 and -0.75, both p < 0.001). Moderate correlations were also seen with the physician global assessment of disease activity (rs = 0.58, p < 0.001), parent global assessment of overall health (rs = -0.65, p < 0.001), Steinbrocker function class (rs = 0.69, p < 0.001), and global skin activity (rs = 0.40, p < 0.001), while global disease damage and skin damage had low correlations (rs = 0.13 and 0.07, p > or =0.17). Responsiveness of the CHAQ was high, with ES = 1.05 and SRM = 1.20. CONCLUSION: In this large cohort of patients with juvenile IIM, the CHAQ exhibited internal reliability, construct validity, and strong responsiveness. We conclude that the CHAQ is a valid measure of physical function in juvenile IIM, appropriate for use in therapeutic trials, and potentially in the clinical care of these patients.

Current medication choices in juvenile rheumatoid arthritis II--update of a survey performed in 1993.

The documentation of treatments used for Juvenile Rheumatoid Arthritis (JRA) is important to allow for the evaluation of practice patterns for future outcome studies. A survey of nine pediatric rheumatologists was performed between September 1999 and February 2000. Each of the physicians prospectively recorded demographic and treatment information on consecutively sampled JRA patients (n=395). Pauciarticular onset JRA was present in 46%, polyarticular onset JRA in 35%, and systemic onset JRA in 19% of the children. Naproxen was the most frequently prescribed medication (55% of the patients), followed by methotrexate (MTX), which was used in 39% of the patients. Folic acid supplementation (1 mg/day) was provided to 69% of the patients treated with MTX. Etanercept was used in 11% of the children. Eleven percent of the patients received corticosteroids, and 13% of children on corticosteroids took calcium supplements. Uveitis was present in 8% and had a chronic course in 79% of those cases. Although systemic medications were used in 50% of the children with uveitis to control eye inflammation, severe damage to the eyes developed in 30% of them. Fourteen percent of the patients required gastroprotective medications. Compared with findings of a similar survey performed in 1993, there was no significant change in the frequency of use of naproxen, but nabumetone is now more often prescribed, and COX-2 inhibitors have been introduced in the therapy of JRA. Changes among second-line agents used for JRA have also occurred, although there was no change in the frequency of use of MTX or corticosteroids. JRA continues to be a treatment challenge for the practicing pediatric rheumatologist. Patients often show incomplete response to the currently available medications. Therefore, new therapeutic agents need to be evaluated for their use in JRA, and the treatment of JRA associated uveitis especially needs to be improved.

Hydrogen peroxide- and peroxynitrite-induced mitochondrial DNA damage and dysfunction in vascular endothelial and smooth muscle cells.

The mechanisms by which reactive species (RS) participate in the development of atherosclerosis remain incompletely understood. The present study was designed to test the hypothesis that RS produced in the vascular environment cause mitochondrial damage and dysfunction in vitro and, thus, may contribute to the initiating events of atherogenesis. DNA damage was assessed in vascular cells exposed to superoxide, hydrogen peroxide, nitric oxide, and peroxynitrite. In both vascular endothelial and smooth muscle cells, the mitochondrial DNA (mtDNA) was preferentially damaged relative to the transcriptionally inactive nuclear beta-globin gene. Similarly, a dose-dependent decrease in mtDNA-encoded mRNA transcripts was associated with RS treatment. Mitochondrial protein synthesis was also inhibited in a dose-dependent manner by ONOO(-), resulting in decreased cellular ATP levels and mitochondrial redox function. Overall, endothelial cells were more sensitive to RS-mediated damage than were smooth muscle cells. Together, these data link RS-mediated mtDNA damage, altered gene expression, and mitochondrial dysfunction in cell culture and reveal how RS may mediate vascular cell dysfunction in the setting of atherogenesis.

Development of validated disease activity and damage indices for the juvenile idiopathic inflammatory myopathies. II. The Childhood Myositis Assessment Scale (CMAS): a quantitative tool for the evaluation of muscle function. The Juvenile Dermatomyositis Disease Activity Collaborative Study Group.

OBJECTIVE: To develop, validate, and determine the measurement characteristics of a quantitative tool for assessing the severity of muscle involvement in children with idiopathic inflammatory myopathies. METHODS: The Childhood Myositis Assessment Scale (CMAS) was developed from 2 existing observational functional assessment tools to assess muscle function in the areas of strength and endurance across a wide range of ability and ages. The 14 ordinal items included were chosen to assess primarily axial and proximal muscle groups and are ranked with standard performance and scoring methods. Following the development of the CMAS, a training video and written instructions were developed and reviewed by the physicians participating in this study. Subsequently, utilizing a randomized block design, 12 physicians independently scored 10 children (9 with dermatomyositis, 1 with polymyositis; ages 4-15 years) twice in one day (morning and afternoon) on the CMAS. A pediatric physical therapist performed quantitative manual muscle strength testing (MMT) twice on each child (morning and afternoon), including the neck, trunk, and proximal and distal extremity muscle groups. RESULTS: The CMAS has a potential range of 0-51, with higher scores indicating greater muscle strength and endurance. The observed mean for the 10 patients was 36.4 (median 44, SD 14.1, observed range 5-51). The total score for the CMAS correlated with the physician's global assessment (by visual analog scale) of disease activity, the MMT score, serum creatine kinase level, and the Juvenile Arthritis Functional Assessment Report score. The score on the CMAS was not correlated with patient age. Interrater reliability (Kendall's coefficient of concordance) ranged from 0.77 to 1.0 for individual items (all P < 0.001), and overall, it was 0.95 (P < 0.001). Intrarater reliability for the individual physicians was measured by correlation of the CMAS scores for each patient on 2 separate evaluations and ranged from 0.97 to 0.99, with an overall correlation for all physicians of 0.98 (all P < 0.001). CONCLUSION: The CMAS demonstrated an acceptable range of observed scores, excellent convergent validity, and excellent inter- and intrarater reliability. The CMAS is validated to quantitatively assess muscle function in the areas of strength and endurance in children with idiopathic inflammatory myopathies. It can be used in routine clinical care as well as therapeutic trials.

Hydrogen peroxide causes significant mitochondrial DNA damage in human RPE cells.

Retinal pigment epithelial cell dysfunction mediated by reactive oxygen intermediates has been suggested as a possible cause of age-related macular degeneration. To test the hypothesis that retinal pigment cells are susceptible to genetic damage mediated by reactive oxygen intermediates, retinal pigment epithelial cells were treated with 50 micrometers-200 micrometers of hydrogen peroxide in vitro. Damage to mitochondrial DNA and three nuclear loci were assessed using quantitative polymerase chain reaction. Hydrogen peroxide treatment of retinal pigment epithelial cells resulted in significantly increased mitochondrial DNA damage. Significant mitochondrial DNA damage occurred rapidly and was not completely repaired within 3 hr post-treatment. By contrast, no DNA damage was observed in three different nuclear loci (beta-globin gene cluster, hprt, and beta- polymerase genes). Hydrogen peroxide treatment of retinal pigment epithelial cells also resulted in decreased mitochondrial redox function compared to controls, consistent with increased mitochondrial DNA damage. Consequently, retinal pigment epithelial cell mitochondrial DNA appears susceptible to hydrogen peroxide mediated damage in vitro, and thus, may serve as a catalyst in the initial events leading to retinal pigment epithelial cell dysfunction in vivo.

Development of validated disease activity and damage indices for the juvenile idiopathic inflammatory myopathies: I. Physician, parent, and patient global assessments. Juvenile Dermatomyositis Disease Activity Collaborative Study Group.

OBJECTIVE: To determine the reliability, content validity, and responsiveness of physician global assessments of disease activity and damage in the juvenile idiopathic inflammatory myopathies (IIM), and to investigate concordance among physician, parent, and patient global ratings. METHODS: Sixteen pediatric rheumatologists rated 10 juvenile IIM paper patient cases for global disease activity and damage, and assessed the importance of 51 clinical and laboratory parameters in formulating their global assessments. Then, 117 juvenile IIM patients were enrolled in a protocol to examine the relationship between Likert and visual analog scale global assessments, their sensitivity to change, and the comparability of physician, parent, and patient global ratings. RESULTS: Pediatric rheumatologists demonstrated excellent interrater reliability in their global assessments of juvenile IIM disease activity and damage (97.7% and 94.7% agreement among raters, respectively), and agreed on a core set of clinical parameters in formulating their judgments. Likert scale ratings correlated with those on a visual analog scale, and both were comparable in responsiveness (standardized response means -0.56 for disease activity, 0.02 [Likert] and 0.14 [visual analog] for damage, measured over 8 months). Parent global ratings of disease activity correlated with physician assessments, but were not colinear (Spearman's correlation [r] = 0.41-0.45). Patient global disease activity assessments correlated with those done by parents (r = 0.57-0.84) and physicians (r = 0.37-0.63), but demonstrated less responsiveness (standardized response means -0.21 and -0.12, respectively, over 8 months). CONCLUSION: Physician global assessments of juvenile IIM disease activity and damage demonstrated high interrater reliability and were shown to be comprehensive measures. Both physician and parent disease activity assessments should be considered valuable as quantitative measures for evaluating therapeutic responses in juvenile IIM patients.

Mitochondrial genome damage associated with cigarette smoking.

We have investigated the level of mitochondrial DNA (mtDNA) damage and deletions in bronchoalveolar lavage tissues from smokers and nonsmokers using quantitative, extra-long PCR and a "common" mtDNA deletion assay. Smokers had 5.6 times the level of mtDNA damage, 2.6 times the damage at a nuclear locus (beta-globin gene cluster), and almost 7 times the level of a 4.9-kb mtDNA deletion compared to nonsmokers, although the latter increase was not significant. Although both genomes (mitochondrial and nuclear) showed significantly increased levels of DNA damage in smokers (mtDNA P = 0.00072; beta-globin P = 0.0056), the relative differences were greatest in the mtDNA. Damage to the mtDNA may inhibit oxidative phosphorylation and, therefore, potentially cause or contribute to chronic lung disease and cancer. Consequently, the mtDNA may be a sensitive biomarker for environmentally induced genetic damage and mutation.

Mitochondrial DNA mutations in human degenerative diseases and aging.

A wide variety of mitochondrial DNA (mtDNA) mutations have recently been identified in degenerative diseases of the brain, heart, skeletal muscle, kidney and endocrine system. Generally, individuals inheriting these mitochondrial diseases are relatively normal in early life, develop symptoms during childhood, mid-life, or old age depending on the severity of the maternally-inherited mtDNA mutation; and then undergo a progressive decline. These novel features of mtDNA disease are proposed to be the product of the high dependence of the target organs on mitochondrial bioenergetics, and the cumulative oxidative phosphorylation (OXPHOS) defect caused by the inherited mtDNA mutation together with the age-related accumulation mtDNA mutations in post-mitotic tissues.

Mitochondrial myopathy with anemia, cardiomyopathy, and lactic acidosis: a distinct late onset mitochondrial disorder.

A 40-year-old woman presented with profound muscle weakness resulting in failure to wean from a ventilator and persistent lactic acidosis after having recovered from a pneumonia complicated by adult respiratory distress syndrome, myocardial infarction, renal failure and shock. She had a 28 year history of chronic anemia and exercise intolerance. Anemia and thrombocytopenia persisted after admission. Nonobstructive hypertrophic cardiomyopathy was present. A stroke-like episode occurred. A mitochondrial myopathy with deficiencies in complexes IV and II was demonstrated, but no DNA defect has yet been found. This patient represents a distinct clinical presentation of a mitochondrial disorder characterized by late onset mitochondrial myopathy, chronic anemia, cardiomyopathy, and lactic acidosis.

Mitochondrial DNA mutations in epilepsy and neurological disease.

Recent discoveries in mitochondrial clinical genetics have revealed that a broad spectrum of clinical phenotypes are associated with mutations in mitochondrial DNA. Diseases caused by mutations in mitochondrial DNA are by nature quantitative. Myoclonic epilepsy and ragged-red fiber disease are caused by a mutation in the transfer RNA gene lysine. Although everyone in a maternal lineage will harbor the same mutation, the nature and severity of the symptoms vary markedly among individuals. This variability correlates with the inherited percentage of mutations in the individual's mitochondrial DNA and the individual's age. Age-related expression of mitochondrial disease has also been demonstrated for mitochondrial DNA deletions. Although deletions that retain both origins of replication result in late-onset disease because of the progressive enrichment of the deleted mitochondrial DNA, a 10.4-kb deletion that lacks the light-strand replication origin and maintains a stable mutant percentage in both tissues and cultured cells has been discovered. This deletion is associated with adult-onset diabetes and deafness, but not with ophthalmoplegia, ptosis, or mitochondrial myopathy. Biochemically, it causes a generalized defect in mitochondrial protein synthesis and oxidative phosphorylation. The age-related decline in oxidative phosphorylation could reflect the accumulation of somatic mitochondrial DNA mutations. Inhibition of oxidative phosphorylation stimulates this accumulation. The general paradigm for mitochondrial DNA diseases may be that inherited mutations inhibit the electron transport chain. This damages the mitochondrial DNA, further reducing oxidative phosphorylation. Ultimately, oxidative phosphorylation drops below the expression threshold of cells and tissues, and clinical symptoms appear.

The use of monozygotic and dizygotic twins to estimate the effects of inheritance on the levels of immunoglobulin isotypes and antibodies to phosphocholine.

In the elderly there is a pronounced increase in susceptibility to infectious disease. Evidence for particular immune deficits that result in susceptibility to specific agents is lacking, however, and there is little information on the degree to which differences in the susceptibility among the elderly are due to genetic versus environmental effects. A strong association has been observed between eventual fatal pneumonia and elevated levels of IgM antibody to phosphocholine (PC) levels at age 70. In this study we evaluated the heritability of IgM and IgG antibody levels to phosphocholine in the elderly using monozygotic and dizygotic male twins. We observed genetic regulation of serum levels of IgM antibody to PC, a finding which suggests that susceptibility of the elderly to fatal pneumonia may be heritable. Levels of total IgM were under separate genetic control and there was no genetic effect on IgG and IgA levels or levels of IgG antibody to phosphocholine.

Maternally transmitted diabetes and deafness associated with a 10.4 kb mitochondrial DNA deletion.

Diabetes mellitus (DM) is one of the most common chronic disorders of children and adults. Several reports have suggested an increased incidence of maternal transmission in some forms of DM. Therefore, we tested a pedigree with maternally transmitted DM and deafness for mitochondrial DNA mutations and discovered a 10.4 kilobase (kb) mtDNA deletion. This deletion is unique because it is maternally inherited, removes the light strand origin (OL) of mtDNA replication, inhibits mitochondrial protein synthesis, and is not associated with the hallmarks of mtDNA deletion syndromes. This discovery demonstrates that DM can be caused by mtDNA mutations and suggests that some of the heterogeneity of this disease results from the novel features of mtDNA genetics.

Allozyme and mitochondrial DNA analysis of a hybrid zone between white-tailed deer and mule deer (Odocoileus) in west Texas.

Thirty allozyme loci and 35 mitochondrial DNA (mtDNA) restriction sites were examined in 24 white-tailed deer and 46 mule deer from a hybrid zone in West Texas. A common mtDNA genotype is shared by all of the mule deer with 67% of the white-tailed deer. At the albumin locus, 13% of the white-tailed deer and 24% of the mule deer are heterozygous, sharing alleles that are otherwise species-specific in allopatric populations; 7% of the mule deer are homozygous for the allele that is characteristic of allopatric white-tailed deer. Gene flow appears to have been bidirectional, with greater genetic introgression into mule deer. The mtDNA data suggest that matings between white-tailed and mule deer have occurred in the past. Despite evidence of genetic introgression, analysis of multilocus genotypes indicates that none of the deer examined is an F1 hybrid. Production of such hybrids appears to be generally uncommon in North American deer; management plans that assume otherwise should be reconsidered.

Southeast Asian mitochondrial DNA analysis reveals genetic continuity of ancient mongoloid migrations.

Human mitochondrial DNAs (mtDNAs) from 153 independent samples encompassing seven Asian populations were surveyed for sequence variation using the polymerase chain reaction (PCR), restriction endonuclease analysis and oligonucleotide hybridization. All Asian populations were found to share two ancient AluI/DdeI polymorphisms at nps 10394 and 10397 and to be genetically similar indicating that they share a common ancestry. The greatest mtDNA diversity and the highest frequency of mtDNAs with HpaI/HincII morph 1 were observed in the Vietnamese suggesting a Southern Mongoloid origin of Asians. Remnants of the founding populations of Papua New Guinea (PNG) were found in Malaysia, and a marked frequency cline for the COII/tRNA(Lys) intergenic deletion was observed along coastal Asia. Phylogenetic analysis indicates that both insertion and deletion mutations in the COII/tRNA(Lys) region have occurred more than once.