Clinical and laboratory characteristics in juvenile-onset systemic lupus erythematosus across age groups.

BACKGROUND: Systemic lupus erythematous (SLE) is a systemic autoimmune/inflammatory condition. Approximately 15-20% of patients develop symptoms before their 18th birthday and are diagnosed with juvenile-onset SLE (JSLE). Gender distribution, clinical presentation, disease courses and outcomes vary significantly between JSLE patients and individuals with adult-onset SLE. This study aimed to identify age-specific clinical and/or serological patterns in JSLE patients enrolled to the UK JSLE Cohort Study. METHODS: Patient records were accessed and grouped based on age at disease-onset: pre-pubertal (≤7 years), peri-pubertal (8-13 years) and adolescent (14-18 years). The presence of American College of Rheumatology (ACR) classification criteria, laboratory results, disease activity [British Isles Lupus Assessment Group (BILAG) and Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2 K) scores] and damage [Systemic Lupus International Collaborating Clinics (SLICC) damage index] were evaluated at diagnosis and last follow up. RESULTS: A total of 418 JSLE patients were included in this study: 43 (10.3%) with pre-pubertal disease onset; 240 (57.4%) with peri-pubertal onset and 135 (32.3%) were diagnosed during adolescence. At diagnosis, adolescent JSLE patients presented with a higher number of ACR criteria when compared with pre-pubertal and peri-pubertal patients [pBILAG2004 scores: 9(4-20] vs. 7(3-13] vs. 7(3-14], respectively, p = 0.015] with increased activity in the following BILAG domains: mucocutaneous (p = 0.025), musculoskeletal (p = 0.029), renal (p = 0.027) and cardiorespiratory (p = 0.001). Furthermore, adolescent JSLE patients were more frequently ANA-positive (p = 0.034) and exhibited higher anti-dsDNA titres (p = 0.001). Pre-pubertal individuals less frequently presented with leukopenia (p = 0.002), thrombocytopenia (p = 0.004) or low complement (p = 0.002) when compared with other age groups. No differences were identified in disease activity (pBILAG2004 score), damage (SLICC damage index) and the number of ACR criteria fulfilled at last follow up. CONCLUSIONS: Disease presentations and laboratory findings vary significantly between age groups within a national cohort of JSLE patients. Patients diagnosed during adolescence exhibit greater disease activity and "classic" autoantibody, immune cell and complement patterns when compared with younger patients. This supports the hypothesis that pathomechanisms may vary between patient age groups.

Outcomes following mycophenolate mofetil versus cyclophosphamide induction treatment for proliferative juvenile-onset lupus nephritis.

BACKGROUND: Juvenile-onset systemic lupus erythematosus (JSLE) is more severe than adult-onset disease, including more lupus nephritis (LN). Despite differences in phenotype/pathogenesis, treatment is based upon adult trials. This study aimed to compare treatment response, damage accrual, time to inactive LN and subsequent flare, in JSLE LN patients treated with mycophenolate mofetil (MMF) versus intravenous cyclophosphamide (IVCYC). METHODS: UK JSLE Cohort Study participants, ≤16 years at diagnosis, with ≥4 American College of Rheumatology criteria for SLE, with class III or IV LN, were eligible. Mann-Whitney U tests, Fisher's exact test and Chi-squared tests were utilized for statistical analysis. RESULTS: Of the patients, 34/51 (67%) received MMF, and 17/51 (33%) received IVCYC. No significant differences were identified at 4-8 and 10-14 months post-renal biopsy and last follow-up, in terms of renal British Isles Lupus Assessment Grade scores, urine albumin/creatinine ratio, serum creatinine, ESR, anti-dsDNA antibody, C3 levels and patient/physician global scores. Standardized Damage Index scores did not differ between groups at 13 months or at last follow-up. Inactive LN was attained 262 (141-390) days after MMF treatment, and 151 (117-305) days following IVCYC ( p = 0.17). Time to renal flare was 451 (157-1266) days for MMF, and 343 (198-635) days for IVCYC ( p = 0.47). CONCLUSION: This is the largest study to date investigating induction treatments for proliferative LN in children, demonstrating comparability of MMF and IVCYC.

Attenuated Phenotype of a Recent House Finch-Associated Mycoplasma gallisepticum Isolate in Domestic Poultry.

Mycoplasma gallisepticum, known primarily as a respiratory pathogen of domestic poultry, has emerged since 1994 as a significant pathogen of the house finch (Haemorhousmexicanus) causing severe conjunctivitis and mortality. House finch-associated M. gallisepticum (HFMG) spread rapidly and increased in virulence for the finch host in the eastern United States. In the current study, we assessed virulence in domestic poultry with two temporally distant, and yet geographically consistent, HFMG isolates which differ in virulence for house finches-Virginia 1994 (VA1994), the index isolate of the epidemic, and Virginia 2013 (VA2013), a recent isolate of increased house finch virulence. Here we report a significant difference between VA1994 and VA2013 in their levels of virulence for chickens; notably, this difference correlated inversely to the difference in their levels of virulence for house finches. VA1994, while moderately virulent in house finches, displayed significant virulence in the chicken respiratory tract. VA2013, while highly virulent in the house finch, was significantly attenuated in chickens relative to VA1994, displaying less-severe pathological lesions in, and reduced bacterial recovery from, the respiratory tract. Overall, these data indicate that a recent isolate of HFMG is greatly attenuated in the chicken host relative to the index isolate, notably demonstrating a virulence phenotype in chickens inversely related to that in the finch host.

Evidence of trade-offs shaping virulence evolution in an emerging wildlife pathogen.

In the mid-1990s, the common poultry pathogen Mycoplasma gallisepticum (MG) made a successful species jump to the eastern North American house finch Haemorhous mexicanus (HM). Subsequent strain diversification allows us to directly quantify, in an experimental setting, the transmission dynamics of three sequentially emergent geographic isolates of MG, which differ in the levels of pathogen load they induce. We find significant among-strain variation in rates of transmission as well as recovery. Pathogen strains also differ in their induction of host morbidity, measured as the severity of eye lesions due to infection. Relationships between pathogen traits are also investigated, with transmission and recovery rates being significantly negatively correlated, whereas transmission and virulence, measured as average eye lesion score over the course of infection, are positively correlated. By quantifying these disease-relevant parameters and their relationships, we provide the first analysis of the trade-offs that shape the evolution of this important emerging pathogen.

Clinical Efficacy of Biosimilar Switch of Adalimumab for Management of Uveitis.

BACKGROUND: Adalimumab has demonstrated efficacy in non-infectious uveitis. With the introduction of biosimilar agents such as Amgevita, we aimed to quantify efficacy and tolerability compared to Humira in a multi-centre UK cohort. METHODS: Patients identified from tertiary uveitis clinics in 3 centres, after institution-mandated switching was implemented. RESULTS: Data collected for 102 patients, aged 2-75 years, with 185 active eyes. Following switch, rates of uveitis flare were not significantly different (13 events before, 21 after, p = .132). Rates of elevated intraocular pressure were decreased (32 before, 25 afterwards, p = .006) and dosing of oral and intra-ocular steroids was stable. Twenty-four patients (24%) requested to return to Humira, commonly due to pain from injection or technical difficulty with the device. CONCLUSION: Amgevita is safe and effective for inflammatory uveitis with non-inferiority to Humira. Significant numbers of patients requested to switch back due to side effects including injection site reactions.

Common garden experiment reveals pathogen isolate but no host genetic diversity effect on the dynamics of an emerging wildlife disease.

Host genetic diversity can mediate pathogen resistance within and among populations. Here we test whether the lower prevalence of Mycoplasmal conjunctivitis in native North American house finch populations results from greater resistance to the causative agent, Mycoplasma gallisepticum (MG), than introduced, recently-bottlenecked populations that lack genetic diversity. In a common garden experiment, we challenged wild-caught western (native) and eastern (introduced) North American finches with a representative eastern or western MG isolate. Although introduced finches in our study had lower neutral genetic diversity than native finches, we found no support for a population-level genetic diversity effect on host resistance. Instead we detected strong support for isolate differences: the MG isolate circulating in western house finch populations produced lower virulence, but higher pathogen loads, in both native and introduced hosts. Our results indicate that contemporary differences in host genetic diversity likely do not explain the lower conjunctivitis prevalence in native house finches, but isolate-level differences in virulence may play an important role.

Use of phage immunity in molecular cloning experiments.

Immunity to phage superinfection is a useful selective marker in molecular cloning experiments. Plasmids which have unique sites for several different restriction endonucleases and which specify immunity to bacteriophage are described.

In vitro analysis of a transcription termination site for RNA polymerase II.

Transcription from the adenovirus major late (ML) promoter has previously been shown to pause or terminate prematurely in vivo and in vitro at a site within the first intron of the major late transcription unit. We are studying the mechanism of elongation arrest at this site in vitro to define the DNA sequences and proteins that determine the elongation behavior of RNA polymerase II. Our assay system consists of a nuclear extract prepared from cultured human cells. With standard reaction conditions, termination is not observed downstream of the ML promoter. However, in the presence of Sarkosyl, up to 80% of the transcripts terminate 186 nucleotides downstream of the start site. Using this assay, we showed that the DNA sequences required to promote maximal levels of termination downstream of the ML promoter reside within a 65-base-pair region and function in an orientation-dependent manner. To test whether elongation complexes from the ML promoter were functionally homogeneous, we determined the termination efficiency at each of two termination sites placed in tandem. We found that the behavior of the elongation complexes was different at these sites, with termination being greater at the downstream site over a wide range of Sarkosyl concentrations. This result ruled out a model in which the polymerases that read through the first site were stably modified to antiterminate. We also demonstrated that the ability of the elongation complexes to respond to the ML termination site was promoter specific, as the site did not function efficiently downstream of a heterologous promoter. Taken together, the results presented here are not consistent with the simplest class of models that have been proposed previously for the mechanism of Sarkosyl-induced termination.

Correction to "Automatic Quality Assessment of Echocardiograms Using Convolutional Neural Networks: Feasibility on the Apical Four-Chamber View".

In the above paper [1], the first footnote should have indicated the following information: A. H. Abdi and C. Luong are joint first authors.

A 30 year perspective of the quality of evidence published in 25 clinical journals: signs of change?

METHODS: The quality of clinical studies published in five different specialties, over three decades was evaluated. Computerised search of the Medline database was undertaken to evaluate the articles published in 25 clinical journals in 1983, 1993, and 2003 from five different specialties (medicine, surgery, paediatrics, anaesthesia, and psychiatry). The number of randomised controlled trials (RCTs), meta-analyses, and other clinical trials (non-RCT) were noted. RESULTS: From the 27,030 articles evaluated, there were 2283 (8.4%) RCTs, 166 (0.6%) meta-analyses, and 4153 (15.4%) other clinical trials. For the proportion of RCTs, the rank order of the specialties was; anaesthesia (503; 18%), psychiatry (294; 9.6%), medicine (899; 8.1%), paediatrics (326; 6.4%), and surgery (261; 5.3%) (p<0.001). For the proportion of meta-analysis, the rank order of the specialties was; psychiatry (36; 1.2%), medicine (105; 0.9%), paediatrics (15; 0.3%), anaesthesia (6; 0.2%), and surgery (4; 0.1%) (p<0.001). Overall, from 1983 to 2003, there were increases in the proportion of RCTs (449, 5.9% to 1027, 9.6%), meta-analysis (0, 0% to 127, 1.2%), and other clinical trials (897, 12% to 1983, 19%) (p<0.001). This trend was apparent in each clinical specialty (p<0.001). CONCLUSIONS: Over the three decades evaluated, clinical trials, notably RCTs and meta-analysis form only a small proportion of articles published in prominent journals from five clinical specialties. This is notwithstanding the modest increases in the proportions of RCTs and meta-analysis over the same period.

Regulation of insulin-receptor mRNA levels by glucocorticoids.

We found with IM-9 human cultured lymphocytes, that the glucocorticoid dexamethasone increased insulin-receptor mRNA levels. This increase correlated in a time- and dose-dependent manner with the increase in the biosynthesis of the insulin-receptor precursor. In addition, in AR42J cultured rat pancreatic acinar cells, dexamethasone increased insulin-receptor mRNA levels. These studies suggest, therefore, that an increase in mRNA levels is an early step in the regulation of the insulin receptor by glucocorticoids in several cell types.

Etiology of pure tricuspid regurgitation based on anular circumference and leaflet area: analysis of 45 necropsy patients with clinical and morphologic evidence of pure tricuspid regurgitation.

Despite recent renewed interest in the detection of tricuspid valve regurgitation by echocardiographic and Doppler techniques, little morphologic information is available on dysfunctioning tricuspid valves. This report describes 45 necropsy patients with clinical and morphologic evidence of pure (no element of stenosis) tricuspid regurgitation and provides morphometric observations (anular circumference, leaflet area) of the tricuspid valve useful in determining the etiology of pure tricuspid regurgitation. Of 45 patients, 24 (53%) had pure tricuspid regurgitation resulting from an anatomically abnormal valve (prolapse in 7, papillary muscle dysfunction in 6, rheumatic disease in 5, Ebstein's anomaly in 3, infective endocarditis in 2, carcinoid tumor in 1), and 21 (47%) had an anatomically normal valve with systolic pulmonary artery hypertension (cor pulmonale in 12, mitral stenosis in 9). Anular circumference was dilated (greater than 12 cm) in patients with various causes of pulmonary hypertension, floppy valve and Ebstein's tricuspid anomaly. Leaflet area was increased in floppy valve and Ebstein's anomaly. Of the 45 patients, 24 had pulmonary systolic artery pressure measurements available for correlation with tricuspid valve morphology. Pulmonary artery pressures accurately predicted morphologically normal from abnormal valves in 16 patients (89%). Morphologic overlap occurred in six patients with pulmonary pressures of 41 to 54 mm Hg. Of these six, the additional knowledge of normal or dilated anular circumference correctly separated valves with normal and abnormal leaflets.

Contributions of the TATA box sequence to rate-limiting steps in transcription initiation by RNA polymerase II.

We have examined the role of the TATA box in determining transcription initiation frequency in vitro by studying a collection of promoters containing different TATA sequences in the context of the adenovirus major late promoter. In addition to measuring transcription rates, we have determined how the sequence changes affected the association and dissociation kinetics and the affinity of TBP binding. We observed that transcription from promoters containing the highest affinity TATA boxes is limited by the rate with which TBP associates with the promoter. In contrast, transcription from promoters containing lower affinity TATA boxes appears to be limited both by how much TBP is bound and by the relatively low occupancy of the conformation that can undergo subsequent steps in preinitiation complex assembly. The implications of these results in understanding the mechanism of transcription enhancement by transcriptional activators is discussed.

DNA bending is an important component of site-specific recognition by the TATA binding protein.

We have used gel electrophoretic methods to analyze the extent, location and direction of the DNA bend induced by the TATA binding protein (TBP) upon binding to a consensus TATA box sequence. Our observations were consistent with the proposed models for the X-ray crystal structure of the TBP-TATA box complex. We have also measured the magnitude and direction of the bend induced by TBP upon binding a number of variant TATA box sequences for which we have measured TBP binding affinity. We found that the extent to which the DNA was bent in the complex differed among the various sequences and was correlated with the stability of the complex; that is, the greater the stability of the complex, the more the DNA appeared to be bent by TBP. This study provides the first evidence that the structure of the TBP-DNA complex may vary with different DNA sequences. In addition, we propose, based on our findings, that the energetics of bending contribute significantly to the overall binding affinity of TBP for different sequences.

Deletion of residues 485-599 from the human insulin receptor abolishes antireceptor antibody binding and influences tyrosine kinase activation.

We have studied insulin and antireceptor antibody binding to mutated human insulin receptors deleted of residues 485-599 in the alpha-subunit by site-directed mutagenesis. Both normal and mutated receptors were expressed in rat HTC hepatoma cells. Cells expressing either the normal receptor or the mutated receptor retained the ability to bind insulin. In contrast to the normal receptor, however, the mutated receptor failed to interact with antireceptor alpha-subunit antibodies. The inability of the mutated receptor to interact with various antireceptor antibodies was further documented by photoaffinity labeling studies. In intact HTC cells expressing mutated receptors, basal insulin receptor tyrosine autophosphorylation was 2-fold elevated when compared to cells expressing normal receptors. In these cells, however, the response of this function to insulin was blunted. When receptors were isolated from these cells and assayed for both autophosphorylation and phosphotransferase activities toward the synthetic substrate poly(Glu, Tyr), the response to insulin was also blunted. To study the ability of the mutated receptor to transmembrane signal, insulin stimulation of S6 kinase activity was measured. In cells with mutated receptors, in concert with the insulin receptor kinase data, basal S6 kinase activity was elevated, and the response to insulin was blunted. The data suggest, therefore, that residues 485-599 in the alpha-subunit of the insulin receptor are critical for antireceptor antibody binding, but not for insulin binding. Moreover, these data suggest that residues 485-599 contain a regulatory domain for insulin regulation of receptor beta-subunit functions.

Glucocorticoid-regulated and constitutive trafficking of proteolytically processed cell surface-associated glycoproteins in wild type and variant rat hepatoma cells.

Glucocorticoids regulate the trafficking of mouse mammary tumor virus (MMTV) glycoproteins to the cell surface in the rat hepatoma cell line M1.54, but not in the immunoselected sorting variant CR4. To compare the localization of MMTV glycoproteins to another proteolytically processed glycoprotein, both wild type M1.54 cells and variant CR4 cells were transfected with a human insulin receptor (hIR) expression vector, pRSVhIR. The production of cell surface hIR was monitored in dexamethasone-treated and -untreated wild type M1.54 and variant CR4 cells by indirect immunofluorescence, direct plasma membrane immunoprecipitation, and by [125I] insulin binding. In both wild type and variant rat hepatoma cells, hIR were localized at the cell surface in the presence or in the absence of 1 microM dexamethasone. In contrast, the glucocorticoid-regulated trafficking of cell surface MMTV glycoproteins occurred only in wild type M1.54 cells. We conclude that the hIR, which undergoes posttranslational processing reactions similar to MMTV glycoproteins, does not require glucocorticoids to be transported to the plasma membrane and is representative of a subset of cell surface glycoproteins whose trafficking is constitutive in rat hepatoma cells. Thus, MMTV glycoproteins and hIR provide specific cell surface markers to characterize the glucocorticoid-regulated and constitutive sorting pathways.

Socioeconomic impact of fibrositis. A study of 81 patients with primary fibrositis.

Demographics and health service utilization were studied for 81 patients with fibrositis during 1985. Patients reported high levels of pain, mild disability, and moderate impairment of global health. Work disability was limited and only 6.3 percent described themselves as disabled. Employed patients were able to work full work weeks. Utilization of outpatient medical services was increased compared with that of control subjects and national averages during the study year, but was consistent with other rheumatic disorders such as osteoarthritis and low back pain. Medication usage was limited and seemed appropriate. Very high hospitalization rates were noted prior to diagnosis of fibrositis, both for musculoskeletal and non-musculoskeletal hospitalizations, but these rates dropped during the post-diagnosis study year.

The effects of kynurenic acid, quinolinic acid and other metabolites of tryptophan on the development of the high pressure neurological syndrome in the rat.

The effects of some biologically active metabolites of tryptophan on the high pressure neurological syndrome (HPNS) were studied. Kynurenic acid, quinolinic acid, 5-hydroxytryptophan, kynurenine and 3-hydroxyanthranilic acid, at doses within the physiological range, were administered exogenously to rats prior to exposure to increased pressure and any effects on the tremor, myoclonus and convulsion end points of the high pressure neurological syndrome were observed. Quinolinic acid (25 and 50 mg/kg) and kynurenine (50 mg/kg) reduced the onset pressure for tremor, but not myoclonus or convulsions. Kynurenic acid (100 mg/kg) increased tremor onset pressure; 5-hydroxytryptophan (20 mg/kg) slightly increased onset pressure for tremor but decreased that for myoclonus. 3-Hydroxyanthranilic acid (20 mg/kg) had no significant effect on any of the motor signs of the syndrome. These data provide further support for the idea that the motor events seen in the high pressure neurological syndrome are not produced by a single mechanism. Differences between the responses to related metabolites suggest that the precise balance between compounds such as kynurenic acid and quinolinic acid may be important in the appearance of the high pressure neurological syndrome.

Leucocyte intracellular pH and Na+/H+ antiport activity in human hypertension.

Hypertension is associated with thickening of the wall of resistance vessels, but the cellular or genetic basis of this is unclear. Cell proliferation and intracellular alkalinization via increased Na+/H+ exchange are linked in the response of tissues to growth factors. To define a possible cellular basis for vascular medial thickening in hypertension, we studied leucocyte intracellular pH, buffering power and Na+/H+ antiport activity in 17 hypertensive and 17 age-, sex- and weight-matched normotensive subjects. The cells from hypertensive subjects were significantly more alkaline [median (range): 7.49 (7.26-7.95) versus 7.39 (7.25-7.53); P less than 0.01], and had a lower buffering power [8.95 (3.05-17.98) versus 12.57 (7.44-19.95) mmol/l per pH unit; P less than 0.02] than those from normotensive subjects. Moreover, the activity of the Na+/H+ antiport was higher when cells were acid-loaded to an intracellular pH of 6.7. The presence of a similar increased activity in vascular smooth muscle cells may be associated with increased cellular proliferation resulting in a thickened media or increased vascular smooth muscle contractility.