Breakthrough SARS-CoV-2 infection and disease flares in patients with rheumatoid arthritis: result from COVAD e-survey study

COVID-19 has been suggested as a possible trigger of disease flares in patients with rheumatoid arthritis (RA). However, factors associated with disease flares remain unknown. This study aimed to identify factors associated with breakthrough infection (BIs) and disease flares in patients with RA following COVID-19. We analysed data from RA patients who participated in the COVID-19 vaccination in autoimmune diseases (COVAD) study. Demographic data, patient-reported outcomes, comorbidities, pharmacologic treatment and details regarding disease flares were extracted from the COVAD database. Factors associated with disease flare-ups were determined by multivariate logistic regression analysis. The analysis comprised 1928 patients with RA who participated in the COVAD study. Younger age, Caucasian ethnicity, comorbidities with obstructive chronic pulmonary disease and asthma were associated with COVID-19 breakthrough infection. Moreover, younger age (odds ratio (OR): 0.98, 95% CI 0.96-0.99, p < 0.001), ethnicity other than Asian, past history of tuberculosis (OR: 3.80, 95% CI 1.12-12.94, p = 0.033), treatment with methotrexate (OR: 2.55, 95% CI: 1.56-4.17, p < 0.001), poor global physical health (OR: 1.07, 95% CI 1.00-1.15, p = 0.044) and mental health (OR: 0.91, 95% CI 0.87-0.95, p < 0.001) were independent factors associated disease flares in patients with RA. Our study highlights the impact of socio-demographic factors, clinical characteristics and mental health on disease flares in patients with RA. These insights may help determine relevant strategies to proactively manage RA patients at risk of flares.

The diagnosis and management of systemic autoimmune rheumatic disease-related interstitial lung disease: British Society for Rheumatology guideline scope

Interstitial lung disease (ILD) is a significant complication of many systemic autoimmune rheumatic diseases (SARDs), although the clinical presentation, severity and outlook may vary widely between individuals. Despite the prevalence, there are no specific guidelines addressing the issue of screening, diagnosis and management of ILD across this diverse group. Guidelines from the ACR and EULAR are expected, but there is a need for UK-specific guidelines that consider the framework of the UK National Health Service, local licensing and funding strategies. This article outlines the intended scope for the British Society for Rheumatology guideline on the diagnosis and management of SARD-ILD developed by the guideline working group. It specifically identifies the SARDs for consideration, alongside the overarching principles for which systematic review will be conducted. Expert consensus will be produced based on the most up-to-date available evidence for inclusion within the final guideline. Key issues to be addressed include recommendations for screening of ILD, identifying the methodology and frequency of monitoring and pharmacological and non-pharmacological management. The guideline will be developed according to methods and processes outlined in Creating Clinical Guidelines: British Society for Rheumatology Protocol version 5.1.

KL6 and IL-18 levels are negatively correlated with respiratory function tests and ILD extent assessed on HRCT in patients with systemic sclerosis-related interstitial lung disease (SSc-ILD)

BACKGROUND

Interstitial lung disease (ILD) is one of the leading causes of mortality in patients with systemic sclerosis (SSc). Serum biomarkers have been suggested as indicators for pulmonary damage with clinical value in the diagnosis and prognosis of SSc-ILD.

OBJECTIVES

To investigate the role of serum biomarkers (Krebs von den Lungen-6 KL-6, IL-18 and IL-18BP) as a potential biomarker reflecting the severity of SSc-ILD as assessed through high-resolution computed tomography (HRCT) and pulmonary function tests (PFT), including forced vital capacity (%FVC) and diffusing capacity of the lung for carbon monoxide (%DLCO).

METHODS

A cross-sectional study including patients with SSc fulfilling the 2013 ACR/EULAR criteria was performed. Patients were classified according to disease duration and pulmonary involvement (presence of ILD). All SSc patients underwent chest HRCT scans and pulmonary function test at baseline. Serum concentration of KL-6, IL8 and IL18BP were determined using the quantitative ELISA technique, sandwich type (solid phase sandwich Enzyme Linked-Immuno-Sorbent Assay), with kits from MyBiosource for KL-6 and from Invitrogen for IL18 and IL18BP. A semiquantitative grade of ILD extent was evaluated through HRCT scan (grade 1, 0-20%; grade 2, >20%). Extensive disease was defined as >20% lung involvement on HRCT, and FVC <70% predicted and limited lung involvement as ≤20% ILD involvement on HRCT, and an FVC ≥70% predicted.

RESULTS

74 patients were included, 27% were male. The mean age at diagnosis was 57.5±15 years and the mean time since diagnosis was 7.67±8 years. 28 patients had ILD (38%). 64% of patients had <20% ILD extent classified through HRCT scan. SSc-ILD patients had elevated serum KL-6 and IL-18 levels compared to patients without ILD (p=0.003 and p=0.04), and those findings were preserved after adjusting for age and sex. Negative correlation between KL-6 levels and%FVC (β=-0.25, p 0.037) and% DLCO (β=-0.28, p 0.02) and between IL-18 levels and%FVC (β=-0.38, p 0.001) and%DLCO (β=-0.27, p 0.03) were found. Serum KL-6 and IL-18 levels successfully differentiated grades 1 and 2 of the semiquantitative grades of ILD extent (p = 0.028 and p = 0.022). Semiquantitative grades of ILD on the HRCT scan were significantly proportional to the KL-6 (p = 0.01) and IL-18 (p = 0.03). A positive correlation between extensive lung disease and KL-6 (β=0.42, p = 0.007) but not with IL-18 was found.

CONCLUSIONS

Serum KL-6 levels and IL-18 were increased in patients with SSc-ILD and showed a positive correlation with ILD severity as measured using a semiquantitative CT grading scale and negative correlation with PFT parameters. Serum KL-6 and IL-18 could be a clinically useful biomarker in screening and evaluating SSc-ILD.

Coalition for Health and Gender Equity (CHANGE)-a protocol for a global cross-sectional survey of health and gender equity in rheumatology

Objectives

The primary aim of the CHANGE survey is to determine the current state of gender equity within rheumatology, and secondarily, to review the physician perspective on bullying, harassment and equipoise of opportunities within rheumatology.

Methods

The CHANGE e-survey is a cross-sectional self-reported questionnaire adapted from EULAR's gender equity in academic rheumatology task force. The survey was launched in January 2023; it is available in six languages and distributed widely via rheumatology organizations and social media. Eligible participants include rheumatologist physicians and rheumatology health-care professionals. Survey responses will undergo descriptive analysis and inter-group comparison aiming to explore gender-based discrimination using logistic regression, with subgroup analyses for country/continent variations.

Conclusion

This e-survey represents a comprehensive global initiative led by an international consortium, aimed at exploring and investigating the gender-related disparities and obstacles encountered by rheumatologists and rheumatology health-care professionals across diverse communities and health-care environments. By pursuing this initiative, we aim to take the broader rheumatology community a step closer to understanding the underlying origins of inequities and their determinants. Such insights are pivotal in identifying viable interventions and strategies to foster gender equity within the field. Ultimately, our collective objective is to ensure equitable access to opportunities for every individual, irrespective of gender, thereby promoting inclusivity and fairness across the entire spectrum of professional practice and career development.

Risk factors for cardiovascular disease in primary Sjögren's syndrome (pSS): a 20-year follow-up study

INTRODUCTION

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterized by a chronic grade of inflammation. Cardiovascular events represent the major causes of morbidity and mortality in patients with inflammatory rheumatic diseases; however, the significance and prevalence of cardiovascular disease in patients with pSS remain unclear.

OBJECTIVE

To determine the clinical significance of cardiovascular disease in pSS and analyze the risk of cardiovascular disease according to glandular/extraglandular involvement and positivity to anti-Ro/SSA and/or anti-La/SSB autoantibodies.

METHODS

A retrospective study including patients diagnosed with pSS fulfilling the 2016 ACR/EULAR classification criteria was followed and evaluated in our outpatient clinic between 2000 and 2022. The prevalence of cardiovascular risk factors with pSS was evaluated, and a possible association with clinical and immunological characteristics, the treatments received, and the impact on cardiovascular disease were determined. Univariate and multivariate regression analyses were performed in an attempt to determine potential risk factors associated with cardiovascular involvement.

RESULTS

A total of 102 pSS patients were included. Eighty-two percent were female, with a mean age of 65±24 years and a disease duration of 12.5 ±6 years. Thirty-six patients (36%) had at least one cardiovascular risk factor. Arterial hypertension was diagnosed in 60 (59%) patients, dyslipidemia in 28 (27%), diabetes in 15 (15%), obesity in 22 (22%), and hyperuricemia in 19 (18%). History of arrhythmia was found in 25 (25%), conduction defects in 10 (10%), arterial peripheral vascular disease in 7 (7%), venous thrombosis in 10 (10%), coronary artery disease in 24 (24%), and cerebrovascular disease in 22 (22%) of patients. Patients with extraglandular involvement had a higher prevalence of arterial hypertension (p=0.04), dyslipidemia (p=0.003), LDL mean values (p=0.038), hyperuricemia (p=0.03), and coronary artery disease (p=0.01) after adjusting for age, sex, disease duration, and the significant variables in the univariate analysis. Patients with Ro/SSA and La/SSB autoantibodies had a substantially higher risk of hyperuricemia (p=0.01), arrhythmia (p=0.01), coronary artery disease (p=0.02), cerebrovascular disease (p=0.02), and venous thrombosis (p =0.03). In the multivariate logistic regression analysis, higher odds of cardiovascular risk factors were associated with extraglandular involvement (p=0.02), treatment with corticosteroids (p=0.02), ESSDAI>13 (p=0.02), inflammatory markers including ESR levels (p 0.007), and serologic markers such as low C3 levels (p=0.03) and hypergammaglobulinemia (p=0.02).

CONCLUSIONS

Extraglandular involvement was associated with a higher prevalence of arterial hypertension, dyslipidemia, hyperuricemia, and coronary artery disease. Anti-Ro/SSA and anti-La/SSB seropositivity was associated with a higher prevalence of cardiac rhythm abnormalities, hyperuricemia, venous thrombosis, coronary artery disease, and cerebrovascular disease. Raised inflammatory markers, disease activity measured by ESSDAI, extraglandular involvement, serologic markers including hypergammaglobulinemia and low C3, and treatment with corticosteroids were associated with a higher risk for cardiovascular comorbidities. Key Points • Patients with pSS are vulnerable to cardiovascular risk factors. There is an interconnection between extraglandular involvement, disease activity, inflammatory markers, and cardiovascular risk comorbidities. • Anti-Ro/SSA and anti-La/SSB seropositivity was associated with a higher frequency of cardiac conduction abnormalities, coronary artery disease, venous thrombosis, and stroke. • Hypergammaglobulinemia, elevated ESR, and low C3 are associated with a higher prevalence of cardiovascular comorbidities. • Valid risk stratification tools to help with prevention and consensus on the management of CVDs in pSS patients are warranted.

Brain glucose hypometabolism and hippocampal inflammation in Goto-Kakizaki rats

Brain glucose hypometabolism and neuroinflammation are early pathogenic manifestations in neurological disorders. Neuroinflammation may also disrupt leptin signaling, an adipokine that centrally regulates appetite and energy balance by acting on the hypothalamus and exerting neuroprotection in the hippocampus. The Goto-Kakizaki (GK) rat is a non-obese type 2 diabetes mellitus (T2DM) animal model used to investigate diabetes-associated molecular mechanisms without obesity jeopardizing effects. Wistar and GK rats received the maintenance adult rodent diet. Also, an additional control group of Wistar rats received a high-fat and high-sugar diet (HFHS) provided by free consumption of condensed milk. All diets and water were provided ad libitum for eight weeks. Brain glucose uptake was evaluated by 2-deoxy-2-[fluorine-18] fluoro-D-glucose under basal (saline administration) or stimulated (CL316,243, a selective β3-AR agonist) conditions. The animals were fasted for 10-12 h, anesthetized, and euthanized. The brain was quickly dissected, and the hippocampal area was sectioned and stored at -80°C in different tubes for protein and RNA analyses on the same animal. GK rats exhibited attenuated brain glucose uptake compared to Wistar animals and the HFHS group under basal conditions. Also, the hippocampus of GK rats displayed upregulated leptin receptor, IL-1β, and IL-6 gene expression and IL-1β and the subunit of the transcription factor NF-κB (p-p65) protein expression. No significant alterations were detected in the hippocampus of HFHS rats. Our data indicated that a genetic predisposition to T2DM has significant brain deteriorating features, including brain glucose hypometabolism, neuroinflammation, and leptin signaling disruption in the hippocampal area.

Factors Associated With Adverse Outcomes in Uveitis Related to Spondyloarthritis: Development of an Outcome Score (SpA-U)

BACKGROUND

Evaluating the efficacy and refractoriness to treatment and determining factors associated with adverse outcomes in uveitis associated with spondylarthritis (SpA) are complicated by the lack of validated outcome measures.

OBJECTIVES

The aims of this study were to develop an outcome score SpA-U in patients with uveitis associated with SpA and to determine factors associated with adverse outcomes in patients with uveitis under systemic treatment.

METHODS

The outcome score SpA-U was defined by best-corrected visual acuity, anterior chamber inflammation, macular edema and inflammation of posterior chamber, global assessment, and refractoriness to treatment. Factors associated with adverse outcomes in uveitis were studied using linear regression. For categorical factors, marginal averages and their SEs are displayed together with linear regression coefficients with 95% confidence intervals. For continuous factors, averages and SDs are reported in addition to linear regression coefficients with 95% confidence interval. Two regression coefficients are reported for each variable: unadjusted and adjusted for age at diagnosis and sex.

RESULTS

One hundred ninety-seven uveitis outbreaks were included. Sixty-two uveitis outbreaks (31%) were classified as severe, 42 as moderate (21%), and 93 as mild (47%) based on the definition and construction of outcome score. The results of the linear regression model revealed that the uveitis activity was more severe in patients with smoking history ( β = 0.34), axial and peripheral involvement ( β = 0.43), Ankylosing Spondylitis Disease Activity Score >2.1 ( β = 0.45), positive HLA-B27 ( β = 0.29), female sex ( β = 0.19), patients with C-reactive protein elevation ( β = 0.002), and bilateral ocular involvement ( β = 0.32). At the same time, shorter disease evolution ( β = -0.02) was associated with less severe uveitis activity.

CONCLUSION

We have determined factors associated with adverse outcomes in patients with uveitis associated with SpA by developing an outcome score SpA-U that integrates ocular inflammatory activity, visual acuity, global assessment, and refractoriness to treatment.

Clinical phenotype in scleroderma patients based on autoantibodies

Objective

We aimed to characterize the clinical phenotype of patients with SSc based on autoantibodies (topoisomerase antibody (Scl-70), ACA and ANA).

Methods

We included patients with SSc who fulfilled the 2013 ACR/EULAR criteria, with disease duration ≤15 years. Six groups of patients were defined: ACA-lcSSC, Scl-70-lcSSc, ANA-lcSSc, Scl-70-dcSSc, ANA-dcSSc and ACA-dcSSc patients. We compared the different groups of patients. In the ANA subgroup, we included patients negative for SSc-specific antibodies (Scl-70 and ACA). We assessed the following: risk of interstitial lung disease (ILD), myositis, scleroderma renal crisis, cardiac involvement, gastrointestinal involvement, pulmonary hypertension, treatment, cancer and all-cause mortality.

Results

One hundred and thirteen SSc patients were included: 72 (64%) females, 82 (73%) lcSSc and 31 (27%) dcSSc. Among patients with lcSSc, 43 (52%) were ACA⁺, 16 (19%) Scl-70⁺ and 23 (28%) ANA⁺, and among patients with dcSSc, 13 (42%) patients were Scl-70⁺, 11 (35%) ANA⁺ and 7 (23%) ACA⁺. Scl-70-lcSSc patients had a significantly shorter time from RP to SSc diagnosis (P = 0.04), higher CRP (P = 0.04), renal scleroderma crisis (P = 0.02), ILD (P = 0.03) and diastolic dysfunction (P = 0.04) than ANA-lcSSc patients. Scl-70-dcSSc patients had a higher rate of myositis (P = 0.04), renal crisis (P = 0.03), CRP elevation (P = 0.002), ILD (P = 0.04), pericardial effusion (P = 0.03) and cancer (P = 0.04) than ANA-dcSSc patients. The risk of ILD was higher in Scl-70 patients during the first 10 years than in ACA⁺ and ANA⁺ patients (P = 0.03 and P = 0.02, respectively). The risk of major organ involvement was higher in Scl-70⁺ patients, followed by ANA⁺ and ACA⁺ patients, throughout 15 years of follow-up. All-cause mortality was higher in dcSSc patients than in lcSSc patients, but no differences were found regarding antibody positivity.

Conclusion

We have characterized the clinical phenotype of patients based on autoantibodies: Scl-70 patients show the greatest risk of major organ involvement, followed by ANA⁺ patients and ACA⁺ patients. The risk of ILD in Scl-70⁺ patients suggests that these patients should be monitored closely, irrespective of skin involvement. These results might provide new ways to help with the early diagnosis and management and in assessment of the prognosis of the disease.

Polyautoimmunity in systemic lupus erythematosus: secondary Sjogren syndrome

BACKGROUND

Sjogren's syndrome (SS) is a chronic autoimmune disease characterized by lymphocytic infiltration of the exocrine glands. It can be associated with other connective tissue diseases, including systemic lupus erythematosus (SLE).

OBJECTIVE

This study aimed to determine the incidence of secondary SS (sSS) in patients diagnosed with SLE (SLE-SS) and compare the clinical and serological features of SLE-SS to SLE only.

METHODS

A retrospective observational study including patients diagnosed with SLE (SLICC criteria) seen at the Rheumatology Department between 1990 and 2020 was performed. A total of 453 SLE patients were assessed for fulfilment of the criteria for SS using the European questionnaire and Schirmer test, fluorescein staining/non-stimulated whole-salivary flow, anti-Ro/La antibodies, and lip biopsy. Anti-Ro/SSA and anti-La/SSB antibodies and rheumatoid factor (RF) were measured at entry and at SS assessment. SLE-SS was defined according to the American-European Consensus Criteria (AECC). SLE-SS was defined as a case that initially only fulfilled SLE classification criteria but which exhibited disease progression during follow-up and then met classification criteria for sSS.

RESULTS

SLE-SS occurred in 11% of the SLE patients. In comparison to SLE-only patients, the SLE-SS group was older at inclusion and onset, and had a longer disease course. Sicca syndrome, oral ulcers, pulmonary involvement, and peripheral neuropathy were more frequent. Anti-SSA, anti-SSB, RF, and total IgG were higher in the SLE-SS group.

CONCLUSION

SLE-SS appears to be a subgroup of patients with distinct clinical and serologic features. The frequency of SLE-SS increases with age. Patients with SLE-SS have a higher frequency of oral ulcers, anti-Ro and anti-La antibodies, and a lower frequency of renal disease, anti-dsDNA antibodies, anti-SM, and lower C3 and C4 hypocomplementemia.

Factors associated with adverse pregnancy outcomes in patients with systemic lupus erythematosus

BACKGROUND

Pregnancies in Systemic lupus erythematosus (SLE) are considered high risk and associated with maternal and obstetric complications.

OBJECTIVES

To determine the most important predictors for each of the main adverse pregnancy outcomes in SLE patients.

METHODS

Patients with SLE were retrospectively analysed from 1990 to 2020. Maternal and fetal complications in pregnant women with SLE were retrieved. We compared clinical and analytical characteristics of SLE patients with adverse pregnancy outcomes to controls with SLE diagnosis without adverse pregnancy outcomes. Qualitative data were analysed by Chi-square test and Fisher's exact test. Continuous variables were analysed by using Student's t test. Multiple logistic regression was performed to determine the predictive factors for adverse pregnancy outcomes with adjustment of confounding factors.

RESULTS

135 multiparous women were included (42% with adverse pregnancy outcomes). A total of 57 pregnancies (42%) were linked to adverse outcomes. The occurrence of abortion was correlated with anti-DNAds (β = 0.71, p = 0.04), renal involvement (β = 0.28, p 0.03), antiphospholipid antibodies (APA) (β = 0.29, p 0.03), erythrocyte sedimentation rate (ESR) elevation (β = 0.81, p = 0.02) and C-reactive protein (CPR) elevation (β = 0.91, p = 0.01). Stillbirth was also correlated with renal involvement (β = 0.26, p = 0.04), APA (β = 0.22, p = 0.03) and ESR elevation (β = 0.53, p = 0.02). Preeclampsia was correlated with direct Coombs positivity (β = 0.42, p = 0.01), serositis (β = 0.31, p = 0.02), ESR elevation (β = 0.52, p = 0.03) and CPR elevation (β = 0.32, p = 0.04). Neonatal Lupus was correlated with anti-RNP (β = 0.16, p = 0.03) and anti-Ro/SSA (β = 0.16, p 0.02).

CONCLUSIONS

The most unfavourable pregnancy outcome in women with SLE was spontaneous abortion. Renal involvement, anti-DNAds positivity, antiphospholipid antibody positivity, anti-Ro/SSA, elevated ESR and a younger age at disease onset increased the risk of pregnancy complications.

Atypical Debut of Granulomatosis with Polyangiitis as Acute Tonsilitis and Strawberry Gum: A Case Report

BACKGROUND

Granulomatosis with polyangiitis (GPA) is a systemic necrotizing vasculitis characterized by necrosis, granulomatous inflammation, and vasculitis. It is characterized by the triad of the upper and lower respiratory system, lung, and kidney disease. Although it is usually a multisystemic disease, limited forms have also been described, and otolaryngological involvement is the first manifestation in up to 80-95% of the cases.

CASE PRESENTATION

In this report, we describe the case of an ANCA negative patient with a limited form of GPA that presented a necrotic lesion confined to the right tonsil compatible with granulomatosis with polyangiitis, which later presented positive ANCA antibodies. Oral lesions may be the initial manifestation of GPA, and systemic involvement can be presented within weeks or months. Although the oral manifestations have been well described, the initial presentation with oral lesions is very rare, and presentation with oropharyngeal manifestation is even rarer. This disease is generally characterized by anti-neutrophil cytoplasmic antibodies (ANCA); however, there are rare cases with negative ANCA.

CONCLUSION

The diagnosis was established based on the clinical presentation and the histopathological findings of the characteristic inflammatory pattern.

Immune responses to mRNA vaccines against SARS-CoV-2 in patients with immune-mediated inflammatory rheumatic diseases

BACKGROUND

Patients with immune-mediated rheumatic diseases (IMRDs) are commonly treated with immunosuppressors and prone to infections. Recently introduced mRNA SARS-CoV-2 vaccines have demonstrated extraordinary efficacy across all ages. Immunosuppressed patients were excluded from phase III trials with SARS-CoV-2 mRNA vaccines.

AIMS

To fully characterise B-cell and T-cell immune responses elicited by mRNA SARS-CoV-2 vaccines in patients with rheumatic diseases under immunotherapies, and to identify which drugs reduce vaccine's immunogenicity.

METHODS

Humoral, CD4 and CD8 immune responses were investigated in 100 naïve patients with SARS-CoV-2 with selected rheumatic diseases under immunosuppression after a two-dose regimen of SARS-CoV-2 mRNA vaccine. Responses were compared with age, gender and disease-matched patients with IMRD not receiving immunosuppressors and with healthy controls.

RESULTS

Patients with IMRD showed decreased seroconversion rates (80% vs 100%, p=0.03) and cellular immune responses (75% vs 100%, p=0.02). Patients on methotrexate achieved seroconversion in 62% of cases and cellular responses in 80% of cases. Abatacept decreased humoral and cellular responses. Rituximab (31% responders) and belimumab (50% responders) showed impaired humoral responses, but cellular responses were often preserved. Antibody titres were reduced with mycophenolate and azathioprine but preserved with leflunomide and anticytokines.

CONCLUSIONS

Patients with IMRD exhibit impaired SARS-CoV-2 vaccine immunogenicity, variably reduced with immunosuppressors. Among commonly used therapies, abatacept and B-cell depleting therapies show deleterious effects, while anticytokines preserved immunogenicity. The effects of cumulative methotrexate and glucocorticoid doses on immunogenicity should be considered. Humoral and cellular responses are weakly correlated, but CD4 and CD8 tightly correlate. Seroconversion alone might not reflect the vaccine's immunogenicity.

Toxic effects of thallium acetate by acute exposure to the nematode C. elegans

BACKGROUND

Thallium (Tl) is a toxic metalloid and an emerging pollutant due to electronic devices and dispersal nearby base-metal mining. Therefore, Tl poses a threat to human health and especially the long-term impact on younger individuals exposed is still unknown. This study aimed to evaluate the toxic effects of thallium acetate in C. elegans in early larval stages, considering physiological and behavioral endpoints, as well as the Tl absorption and bioaccumulation.

METHODS

Caenorhabditis elegans (C. elegans) was exposed to Thallium acetate (50, 100, 150, 200, 250, 500, and 1000 μM) in the L1 larval stage, with the purpose to observe the toxic effects invoked until adulthood. Transgenic worms strains were transported GFP, reporters to DAF-16 and were used to verify the antioxidant response. ICP-MS quantified total Tl⁺ concentration to evidence Tl uptake and bioaccumulation.

RESULTS

Thallium acetate caused a significant reduction in the number of living worms (p < 0.0001 in 100-1000 μM), a delay in larval development (p < 0.01; p < 0.001 and p < 0.0001 in 100-1000 μM) through the larval stages, and egg production in the worm's uterus was reduced. Thallium acetate also induced behavioral changes. Additionally, thallium acetate activated antioxidant pathway responses in C. elegans by translocating the DAF-16 transcription factor and activation of SOD-3::GFP expression. The Tl⁺ quantification in worms showed its absorption in the L1 larval stage and bioaccumulation in the body after development.

CONCLUSIONS

Thallium acetate reduced survival, delayed development, caused behavioral changes, induced responses inherent to oxidative stress, and serious damage to the worm's reproduction. In addition, C. elegans absorbed and bioaccumulated Tl⁺. Together, our results highlight the impacts of Tl⁺ exposure in the early stages of life, even for a short period.

Root deformation affects mineral nutrition but not leaf gas exchange and growth of Genipa americana seedlings during the recovery phase after soil flooding

Root deformation (RD) caused by errors in the pricking out process are irreversible and very difficult to detect in container-grown seedlings at the time of planting in the field. The objective of this study was to evaluate the effects of RD on leaf gas exchange, growth, biomass allocation and mineral nutrition of G. americana seedlings during the recovery phase after soil flooding. Four-months-old seedlings, with and without RD, were flooded for 42 days and their recovery was evaluated 28 days after soil drainage. There were no significant interactions between RD and soil flooding for all leaf gas exchange, growth and mineral nutrition after soil drainage, with the exception of leaf P concentrations. In plants with no RD, the P concentration in leaves of non-flooded plants was significantly higher than that of plants with RD. Soil flooding and RD did not influence leaf or root N concentrations or whole-plant N content. RD increased the K concentration in the roots, but not in the leaves. Changes in the nutrient concentrations in leaves and roots indicate that RD may affect physiological performance of seedlings after planting in the field.

First molecular evidence of frogs as a food source for sand flies (Diptera: Phlebotominae) in Brazilian caves

Genus and species of phlebotomine sand flies have been recorded and described in caves in Brazil, but no study has provided the food source used by sand flies in these environments. Herein, we identified the blood source used by sand fly species in caves located at "Quadrilátero Ferrífero" (QF), Minas Gerais state. Specimens were manually collected near or on anurans inside ferruginous caves in Serra do Gandarela National Park and Serra do Rola Moça State Park. Males and females were placed in vials with 70% alcohol and stored at -10°C. Females engorged, after specific identification, had DNA extracted and followed for PCR amplification using specific primers. Sequencing was analyzed in the GenBank and Barcode of Life. A total of 198 specimens were collected (107 females and 91 males), all of them belonging to species Sciopemyia aff. microps (88.89%), Sciopemyia sordellii (10.61%), or Martinsmyia oliveirai (0.50%). When it comes to the females, 89 were S. aff. microps and 18 S. sordellii. Nineteen engorged females of S. aff. microps were analyzed and most of them (n=18) presented blood from Bokermannohyla martinsi and one contained blood from Scinax fuscovarius. The blood present in engorged females of S. sordellii (n=4) was from B. martinsi. Sciopemyia genus specimens are commonly found in collections carried out inside natural caves, but this was the first study to prove that females of this genus feed on cold-blooded animals in nature. HIGHLIGHTS: • Here we proved that sand flies feed in cold-blooded animals in in Brazilian caves. • Females of the Sciopemyia genus were for the first time found feeding in natural habitats. • Anurans of the family Hylidae were identified as source by molecular analyzes. • Insect bloodmeal identification can help assessing the fauna in several biomes. • This is the first record of S. aff. microps in caves of Brazil.

Anti-TNF-α-induced lupus syndrome : Two case reports and review of current literature

Anti-tumor necrosis factor‑α (TNF-α)-induced lupus (ATIL) represents a diagnostic and treatment challenge. Most cases are caused by infliximab and in some cases by etanercept and adalimumab. Symptoms can range from cutaneous manifestations to more rare and serious conditions. Diagnosis requires a temporal relationship between symptoms and positive autoantibody determination. Arthritis and cutaneous symptoms are the most common manifestations accompanied by positive antinuclear antibody (ANA) and anti-double strand DNA (dsDNA) determinations. The etiology of ATILS remains to be definitively established. Several mechanisms have been proposed for anti-TNF-α-induced lupus, including apoptosis, immunosuppression and humoral autoimmunity. Treatment includes discontinuation of anti-TNF‑α agents and in some cases corticosteroids and immunosuppressors. Questions to be answered: (1) Are soluble TNF receptor fusion proteins such as etanercept and anti-TNF chimeric antibodies equally likely to cause ATIL? (2) Can patients with ATIL switch from one anti-TNF‑α antagonist to another? (3) Can the concurrent use of a conventional synthetic disease-modifying antirheumatic drug (csDMARD) like methotrexate or hydroxychloroquine reduce the probability of ATIL?

Microbial source tracking and antimicrobial resistance in one river system of a rural community in Bahia, Brazil

Use of antibiotics inevitably leads to antimicrobial resistance. Selection for resistance occurs primarily within the gut of humans and animals as well as in the environment through natural resistance and residual antibiotics in streams and soil. We evaluated antimicrobial resistance in Gram negative bacteria from a river system in a rural community in Bahia, Brazil. Water was collected from the Jiquiriçá and Brejões rivers and the piped water supply. Additionally, stools were collected from a random sample of residents, cows, pigs and horses near the river. The samples were screened for bacteria resistant to ciprofloxacin, cefotaxime, and meropenem and identified biochemically at the genus and species levels. Microbial source tracking demonstrated that ruminant and human fecal contamination increased as the rivers neared the village center and decreased after the last residence. Antibiotic bacteria were identified from all samples (n = 32). No bacteria were resistant to carbapenems, but the majority of the enterobacteria were resistant to ciprofloxacin, even though this class of antibiotics is not commonly used in food animals in this region. Considering these facts, together with the pattern of human fecal contamination, a human source was considered most likely for these resistant isolates.

Biological agents for rheumatic diseases in the outbreak of COVID-19: friend or foe?

Background

The recent outbreak of COVID-19 has raised concerns in the rheumatology community about the management of immunosuppressed patients diagnosed with inflammatory rheumatic diseases. It is not clear whether the use of biological agents may suppose a risk or protection against SARS-CoV-2 infection; however, it has been suggested that severe respiratory forms of COVID-19 occur as a result of exacerbated inflammation status and cytokine production. This prompted the use of interleukin 6 (IL-6) (tocilizumab and sarilumab) and IL-1 inhibitors (anakinra) in severe COVID-19 disease and more recently JAK1/2 inhibitor (baricitinib). Therefore, patients with rheumatic diseases provide a great opportunity to learn about the use of biological agents as protective drugs against SARS-CoV-2.

Objectives

To estimate COVID-19 infection rate in patients treated with biological disease-modifying antirheumatic drugs (bDMARDs) for inflammatory rheumatic diseases (RMD), determine the influence of biological agents treatment as risk or protective factors and study the prognosis of patients with rheumatic diseases receiving biological agents compared to the general population in a third-level hospital setting in León, Spain.

Methods

We performed a retrospective observational study including patients seen at our rheumatology department who received bDMARDs for rheumatic diseases between December 1st 2019 and December 1st 2020, and analysed COVID-19 infection rate. All patients who attended our rheumatology outpatient clinic with diagnosis of inflammatory rheumatic disease receiving treatment with biological agents were included. Main variable was the hospital admission related to COVID-19. The covariates were age, sex, comorbidities, biological agent, duration of treatment, mean dose of glucocorticoids and need for intensive care unit. We performed an univariate and multivariate logistic regression models to assess risk factors of COVID-19 infection.

Results

There were a total of 4464 patients with COVID-19 requiring hospitalisation. 40 patients out of a total of 820 patients with rheumatic diseases (4.8%) receiving bDMARDs contracted COVID-19 and 4 required hospital care. Crude incidence rate of COVID-19 requiring hospital care among the general population was 3.6%, and it was 0.89% among the group with underlying rheumatic diseases. 90% of patients receiving bDMARDS with COVID-19 did not require hospitalisation. Out of the 4464 patients, 869 patients died, 2 of which received treatment with biological agents. Patients with rheumatic diseases who tested positive for COVID-19 were older (female: median age 60.8 IQR 46-74; male: median age 61.9 IQR 52-70.3) than those who were negative for COVID-19 (female: median age 58.3 IQR 48-69; male: median age 56.2 IQR 47-66), more likely to have hypertension (45% vs 26%, OR 2.25 (CI 1.18-4.27), p 0.02), cardiovascular disease (23 % vs 9.6%, OR 2.73 (1.25-5.95), p 0.02), be smokers (13% vs 4.6%, OR 2.95 (CI 1.09-7.98), p 0.04), receiving treatment with rituximab (20% vs 8%, 2.28 (CI 1.24-6.32), p 0.02) and a higher dose of glucocorticoids (OR 2.5 (1.3-10.33, p 0.02) and were less likely to be receiving treatment with IL-6 inhibitors (2.5% vs 14%, OR 0.16, (CI 0.10-0.97, p 0.03). When exploring the effect of the rest of the therapies between groups (affected patients vs unaffected), we found no significant differences in bDMARD proportions. IL-1 inhibitors, IL-6 inhibitors, JAK inhibitors and belimumab-treated patients showed the lowest incidence of COVID-19 among adult patients with rheumatic diseases. We found no differences in sex or rheumatological disease between patients who tested positive for COVID-19 and patients who tested negative.

Conclusions

Overall, the use of biological disease-modifying antirheumatic drugs (bDMARDs) does not associate with severe manifestations of COVID-19. Patients with rheumatic disease diagnosed with COVID-19 were more likely to be receiving a higher dose of glucocorticoids and treatment with rituximab. IL-6 inhibitors may have a protective effect.

Pyroligneous acid from Mimosa tenuiflora and Eucalyptus urograndis as an antimicrobial in dairy goats

AIMS

To evaluate the applicability of the Mimosa tenuiflora and Eucalyptus urograndis pyroligneous acids (PAs) as alternative antiseptics in dairy goats.

METHODS AND RESULTS

Cytotoxicity was evaluated in vitro using bacteria, as well as in vivo using goats, and the influence of PAs on the physicochemical parameters of fresh milk were examined. The cytotoxicity of PAs was evaluated in terms of morphology, cell viability and metabolic activity of goat tegumentary cells. The PA of M. tenuiflora had results similar to those of 2% iodine. For the in vitro tests, strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were used with the well technique, demonstrating inhibition halos greater than 9 mm. In the in vivo test, 15 animals were used per phase of the experiment, and the plate counting technique showed that there was antiseptic action of both extracts, with emphasis on the M. tenuiflora PA. Physicochemical analysis of the milk showed that neither PAs interfered with its physical-chemical parameters.

CONCLUSIONS

The PA of M. tenuiflora presented potential as an alternative antiseptic in dairy goats.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates the use of PA as an antimicrobial agent in animals.

Effects of octenidine applied alone or mixed with sodium hypochlorite on eukaryotic cells

AIM

To assess the effects of octenidine dihydrochloride (OCT) on eukaryotic cells and the cytotoxicity of OCT associated with sodium hypochlorite - NaOCl (NaOCl/OCT).

METHODOLOGY

L929 fibroblasts and human osteoblast-like cells (Saos-2) were exposed to 0.1% OCT, 2% CHX, 2.5% NaOCl, 5.25% NaOCl and mixtures of 5.25% NaOCl and 0.1% OCT (NaOCl/OCT) at 90 : 10, 80 : 20 and 50 : 50 ratios. Cell viability was assessed by methyl-thiazol-tetrazolium (MTT) and neutral red (NR) assays; type of cell death, by flow cytometry; cytoskeleton, by actin and α-tubulin fluorescence; and alkaline phosphatase (ALP) activity, by thymolphthalein release. The data were analysed by two-way ANOVA and Bonferroni tests (α = 0.05).

RESULTS

MTT and NR assays revealed that 0.1% OCT had the lowest cytotoxicity (P < 0.05), followed by 2% CHX (P < 0.05). The 2.5% NaOCl, NaOCl/OCT 80 : 20 and NaOCl/OCT 50 : 50 solutions had intermediate cytotoxicity. NaOCl 5.25% and NaOCl/OCT 90 : 10 had the highest cytotoxicity (P < 0.05). The OCT group had a higher percentage of viable cells than the NaOCl and CHX groups (P < 0.05), and induced apoptosis at higher doses. The cytoskeleton alterations were observed at 0.12%, 0.6% and 2.02% for the NaOCl, CHX and OCT groups, respectively. The solutions did not induce ALP activity.

CONCLUSION

Octenidine dihydrochloride was less cytotoxic, induced apoptosis at higher doses, caused few changes in the cytoskeleton and did not induce alkaline phosphatase activity. In addition, octenidine dihydrochloride reduced the cytotoxicity of 5.25% NaOCl when combined at 20 and 50%.

Caloric restriction-induced weight loss with a high-fat diet does not fully recover visceral adipose tissue inflammation in previously obese C57BL/6 mice

Caloric restriction (CR) reduces body weight and systemic inflammation, but the effects on adipose tissue under dietary lipid overload are controversial. We evaluated the effects of CR-induced weight loss with a high-fat diet on adipose tissue inflammation of obese mice. Male mice were assigned into low-fat diet (LF) and high-fat diet (HF) groups. After 8 weeks, the mice in the HF group were reassigned for another 7 weeks into the following 3 conditions: (i) kept in the HF condition; (ii) changed to low-fat diet ad libitum (LFAL); and (iii) changed to high-fat calorie-restricted (RHF) diet to reach LFAL body weight. Serum markers, adipocytokines, morphology, and inflammatory infiltrates in retroperitoneal adipose tissue (RAT) were accessed. The body weights of the LFAL and RHF groups were reduced, equaling the body weights of the LF group. The LFAL mice had restored almost all inflammatory markers as the LF mice, except tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and adiponectin. Compared with the HF group, the RHF group had lowered visceral adiposity, retroperitoneal adipocyte sizes, and RAT inflammatory cell infiltration, as well as TNF-α, interleukin-6, and hepatic and serum C-reactive protein, which were higher than that of the LFAL group; adiponectin and MCP-1 did not change. CR with high-fat diet reduced body weight and attenuated visceral adiposity but did not fully recover visceral tissue inflammation. Novelty Caloric restriction in a high-fat diet ameliorated visceral adiposity. Caloric restriction in a high-fat diet did not recover visceral adipose tissue inflammation.

Composition of semen and foreskin mucosa aerobic microbiota and its impact on sperm parameters of captive collared peccaries (Pecari tajacu)

AIM

To evaluate the bacterial composition of collared peccary semen and foreskin mucosa, and to verify the sensitivity of isolates to antimicrobials used in semen conservation and to Aloe vera gel, which is an alternative external cryoprotectant.

METHODS AND RESULTS

Nine foreskin mucosa and ejaculate samples from adult animals were used. Sperm characteristics and bacterial load were evaluated in fresh semen. The preputial mucosa and semen bacterial isolates were identified and tested against five concentrations of each antimicrobial (streptomycin-penicillin and gentamicin) and A. vera gel. Corynebacterium sp. and Staphylococcus sp. were isolated in greater numbers than others in both semen (64·10 and 20·51%, respectively) and the foreskin mucosa (60·60 and 24·25%, respectively), and ranged from 0·4 to 21 × 10⁵ colony-forming units (CFU) per ml. The average load of Corynebacterium sp. was negatively correlated (P < 0·05) with the sperm membrane integrity (r = -0·73055) and curvilinear velocity (r = -0·69048). Streptomycin-penicillin and gentamicin inhibited most micro-organisms, and A. vera showed lower antimicrobial activity.

CONCLUSION

Several Gram-positive bacteria are present in semen and foreskin mucosa of collared peccary, and the benefits of using primarily penicillin-streptomycin and gentamicin antimicrobials in the bacterial control of diluted semen of these animals are strongly indicated.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides insight into the reproductive microbiota of captive male-collared peccary. This work provides a theoretical basis to assist reproductive biotechnologies for ex situ conservation of the species.

Distinct beneficial effects of continuous vs accumulated exercise training on cardiovascular risk factors in Wistar rats

We compared the effects of continuous exercise (CE) vs accumulated exercise (AE) training on CVD risk factors and heart of young male Wistar rats. The exercise training (ET) was performed in a swimming pool for 30-60 min/day, 5 days/week over 15 weeks. CE group performed the ET in a single long daily session (30-60 min), while AE group performed the ET at the same frequency, intensity, and duration of CE rats, but in three short bouts over the course of a day (10-20 min in three daily sessions). AE training was more efficient than CE in attenuating body and fat weight gain and inhibiting visceral adipocyte hypertrophy at the same food intake level. CE training was more efficient in improving systolic blood pressure, LDL/HDL cholesterol, and serum triglyceride. Both ET protocols increased heart function, decreased lipid peroxidation, and increased intracellular Hsp72 content in the heart. This work shows distinct beneficial effects of CE vs AE training suggesting that the prescription of one or other may be preferred to prevent the increase of a specific CVD risk factor.

Impact of puberty status and melengestrol acetate supplementation before the breeding period on reproductive efficiency of Bos indicus beef heifers

Two experiments were designed to evaluate the impact of puberty status and the administration of melengestrol acetate (MGA) before onset of the breeding period on ovulatory responses (Exp. 1) and conception rate after AI performed on estrus detection during 10 d and the pregnancy rate through 80 d of breeding period (Exp. 2) of pasture-grazed beef heifers. In Exp. 1, heifers (15 pubertal and 15 prepubertal) received 0.5 mg per heifer/d -1 of MGA over 14 d. No differences in the ovulatory responses were found 10 d after the MGA administration (pubertal = 46.7% vs. prepubertal P = 53.3%; P = 0.72). In Exp. 2, 368 heifers were randomly assigned to groups according to pubertal status and the MGA treatment. All heifers were inseminated on estrus detection for up 10 d after MGA administration and following exposure to bulls between 20 and 80 d. The MGA-treated heifers exhibited a greater AI service rate than control heifers (72.1 vs. 41.6%;P < 0.01); however, heifers receiving MGA had lower conception results following AI (51.6 vs. 71.4%; P = 0.01). In addition, MGA-treated heifers were more likely to have a corpus luteum in the middle of the breeding period (95.3 vs. 87.5%;P < 0.01), although the Cox proportional hazard of pregnancy rate was similar (P = 0.29) at the end of the breeding period. At onset of the breeding period, pubertal heifers presented a greater pregnancy rate following AI (pubertal P = 42.2% vs. prepubertal P = 24.9%; P = 0.01). Therefore, pubertal heifers seem to have greater overall reproductive efficiency than prepubertal heifers, particularly at the beginning of the breeding period. Interestingly, administration of MGA before the onset of the breeding period increased AI service rate but did not alter the rate of pregnancy throughout the breeding period of pasture-grazed beef heifers.

Abstract P6-06-05: Down-regulation of the circadian factor Period 2 by the oncogenic E3 ligase Mdm2: Relevance of circadian components for cell cycle progression

Circadian rhythms are mechanisms that measure time on a scale of about 24 h and that adjusts our body to external environmental signals. Core circadian clock genes are defined as genes whose protein products are necessary components for the generation and regulation of circadian rhythms. Circadian proteins also regulate genes involved in either cell division or death; and a perturbation of the balance among these processes leads to cancer development and progression.

A key aspect of cancer research is identifying new regulatory pathways involved in proliferation and differentiation of cell. Disruption of circadian rhythm has recently emerged as a new potential risk factor in the development of cancer, pointing to the core gene period 2 (per2) as a tumor suppressor. However, it remains unclear how the circadian network regulates tumor suppression, nor which, if any, of its components is either the ultimate effector that influences the fate of the cell.

Initial experiments were devoted to identifying new interacting partners for Per2 using a two-hybrid system. Interestingly, among the positive clones analyzed was the oncogenic protein Mdm2. This result was validated by immunoprecipitation of recombinant and endogenous Per2/Mdm2 complexes from unstressed cells. Pull-down assays using tagged-expressed proteins fragments and labeled proteins were later used to map the interacting regions between Per2 and Mdm2. Our results show Mdm2 binds to the central flexible region of Per2 known to interact with various protein partners. Thus, we hypothesized that binding of Mdm2 to Per2 might act by mediating its ubiquitination and therefore altering Per2 stability. We next examined the formation of the Mdm2/p53/Per2 complex by immunoprecipitation. Our data show anti-p53 antibody is able to co-immunoprecipitate Per2 and Mdm2. Moreover, in vitro and in vivo ubiquitination assays show that binding of Per2 to p53 prevented ubiquitination of p53 by Mdm2 without altering their binding. Immunofluorescence studies using H1299 cells (p53-) confirmed Per2 role in p53 stabilization and for localization. Overall our results suggest that Mdm2 modulates the stability of Per2 and p53 in unstressed cells, and might be responsible for the oscillatory levels of these proteins observed in a 24 h cycle.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-06-05.

P5-03-04: Circadian Modulation of Estrogen Receptor alpha Promoter Activity

The circadian clock is a molecular mechanism that synchronizes environment variations with physiological changes. Disruption of the circadian clock has been linked to increased risk in diseases and a number of disorders (e.g. jet lag, insomnia, coronary heart disease and cancer). Period 2 (PER2), a circadian protein, is at the center of the clock's function. The complete loss of per2 has been shown to be common in several types of cancer including breast and ovarian. Epidemiological studies established a correlation between circadian disruption and the development of estrogen dependent tumors. The expression of estrogen receptor alpha (ERa) mRNA oscillates in a 24-hour period and, unlike PER2, ERa peaks during the light phase of the day. Because up regulation of ER relates to tumor development, defining the mechanisms of ERa expression will contribute to our comprehension of cellular proliferation and regulation of normal developmental processes. The overall goal of this project is to investigate the molecular basis for circadian control of estrogen receptor alpha (ERa) transcription.

Transcriptional activation of ERa was measured using a reporter system in Chinese Hamster Ovary and MCF-7 cell lines. Data show that PER2 influence ERa transcription through a non-canonical mechanism independent of its circadian counterparts. Promoter analysis using the Alibaba 2.0 suite revealed the presence of various putative novel partners. Among them, OCT-1 was found to directly interact with Per2, in vitro, and with corresponding response element within the ERa promoter. The predicted binding site of OCT-1 is 267 bps upstream of the promoter. Pull-down assays were used to map direct interaction of various PER2 recombinant proteins and the DNA-binding domain of OCT-1. Radiolabeled OCT-1 was found to bind to the C-terminal end of PER2. Electrophoretic mobility shift assays were used to determine direct binding of OCT-1 to the promoter. ChIP assay confirmed the recruitment of PER2 to the estrogen promoter by OCT-1. Fluorescence anisotropy and surface plasmon resonance were employed to establish the binding affinity of OCT-1 to the ERa promoter and PER2. OCT-1 was found to have a high affinity for the ERa promoter (∼10 nM). Furthermore, OCT-1 recruits PER2 to the estrogen promoter. Preliminary data suggests that the transcription factor PER2 might play a role in the regulation of the estrogen promoter.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-03-04.

Strain-dependent arthritogenic potential of the zoonotic pathogen Corynebacterium ulcerans

During the last decade the majority of diphtheria cases in Europe had Corynebacterium ulcerans as the etiologic agent with dogs and cats as the reservoir hosts. However, little has been documented about the virulence factors of this zoonotic pathogen. To set up an in vivo experimental C. ulcerans infection model, conventional Swiss Webster mice were intravenously infected with different doses (from 1 × 10(7) to 5 × 10(9) bacteria per mouse) of C. ulcerans strains, namely 809 (from human lower respiratory tract), BR-AD22 (from asymptomatic dog nares) and CDC-KC279. Mortality rates were demonstrated by LD(50) values ranging from 1.9 × 10(8) to 1.3 × 10(9). Viable bacteria were recovered from blood, kidneys, liver, spleen and joints. For CDC-KC279 and 809 strains (2 × 10(8)mL(-1)) approximately 85% and 72% of animals with articular lesions were observed, respectively; BR-AD22-infected mice showed no signs of arthritis. CDC-KC279 and 809 strains exhibited higher arthritogenic potential when compared to the homologous toxigenic (ATCC27012) and non-toxigenic (ATCC27010) strains of Corynebacterium diphtheriae. A high number of affected joints and arthritis index in addition to the histopathological features, including subcutaneous edema, inflammatory infiltrate, damage to bone tissue and synoviocyte hypertrophy, indicated a strain-dependent ability of C. ulcerans strains to cause severe polyarthritis. A correlation between the arthritis index and systemic levels of IL-6 and TNF-α was observed for C. ulcerans strains, with the exception of the non-arthritogenic BR-AD22 strain. In conclusion, C. ulcerans revealed a strain-dependent arthritogenic potential independent of DNAse, PLD and diphtheria toxin production.

Expression and purification of the immunogenically active fragment B of the Park Williams 8 Corynebacterium diphtheriae strain toxin

The construction of a hexahistidine-tagged version of the B fragment of diphtheria toxin (DTB) represents an important step in the study of the biological properties of DTB because it will permit the production of pure recombinant DTB (rDTB) in less time and with higher yields than currently available. In the present study, the genomic DNA of the Corynebacterium diphtheriae Park Williams 8 (PW8) vaccine strain was used as a template for PCR amplification of the dtb gene. After amplification, the dtb gene was cloned and expressed in competent Escherichia coli M15 cells using the expression vector pQE-30. The lysate obtained from transformed E. coli cells containing the rDTB PW8 was clarified by centrifugation and purified by affinity chromatography. The homogeneity of the purified rDTB PW8 was confirmed by immunoblotting using mouse polyclonal anti-diphtheria toxoid antibodies and the immune response induced in animals with rDTB PW8 was evaluated by ELISA and dermonecrotic neutralization assays. The main result of the present study was an alternative and accessible method for the expression and purification of immunogenically reactive rDTB PW8 using commercially available systems. Data also provided preliminary evidence that rabbits immunized with rDTB PW8 are able to mount a neutralizing response against the challenge with toxigenic C. diphtheriae.

Improvement in the molecular diagnosis of Machado-Joseph disease

BACKGROUND

Direct detection of the gene mutation allows for the confirmation of the clinical diagnosis of Machado-Joseph disease (MJD), the most frequent cause of autosomal dominant spinocerebellar ataxia worldwide.

OBJECTIVE

To address the main difficulties in our national MJD predictive testing program. The first was the emergence of intermediate alleles, for which it is not yet possible to determine whether they will cause disease. The second was the issue of homoallelism, ie, homozygosity for 2 normal alleles with exactly the same (CAG)(n) length, which occurs in about 10% of all test results.

METHODS

A large pedigree with 1 affected patient carrying a 71 and a 51 CAG repeat and 2 asymptomatic relatives carrying the 51 CAG repeat and normal-size alleles underwent clinical and molecular studies. Intragenic haplotypes for these alleles were determined. A representative sample of the healthy population in the region was obtained to assess the distribution of the normal (CAG)(n) length. We established the genotype for 4 intragenic polymorphisms in the gene for MJD (MJD1) in 21 homoallelic individuals, to distinguish their 2 normal chromosomes. In addition, we developed a new Southern blot method to completely exclude cases of nonamplification of expanded alleles in the homoallelic individuals.

RESULTS

The study of the family in which the 51 CAG repeat was found suggests that the allele is apparently not associated with disease. These intermediate alleles were not present in a large sample of the healthy population from the same region. Intragenic polymorphisms allowed distinction of the 2 different normal alleles in all cases of homoallelism. The absence of an expanded allele was also confirmed by Southern blot.

CONCLUSIONS

We propose an improved protocol for molecular testing for MJD. These strategies, developed to overcome the practical difficulties mostly in the presymptomatic and prenatal diagnosis of MJD, should prove useful for other polyglutamine-related disorders.

Intravenous valproate associated with significant hypotension in the treatment of status epilepticus

Intravenous valproate has been suggested for the treatment of status epilepticus in part because of its relatively good cardiovascular safety profile. We report a case of severe hypotension associated with intravenous valproate used to treat status epilepticus in an 11-year-old girl. Valproate 960 mg (30 mg/kg) was infused over 1 hour. The patient's blood pressure decreased from a baseline of 130/80 mm Hg to 70/55 mm Hg, 39 minutes into the infusion. Although her seizures stopped, her blood pressure fluctuated between 90/60 mm Hg and 60/30 mm Hg over the next several hours, requiring treatment with intravenous fluids and pressor therapy. Endotracheal intubation eventually was performed. Once her blood pressure stabilized, the patient improved clinically. To our knowledge, this is the first report of significant hypotension associated with intravenous valproate in the treatment of status epilepticus in the pediatric population.

Montenegro skin tests for American cutaneous leishmaniasis carried out on school children in Rio de Janeiro, Brazil: An indicator of transmission risk

Montenegro skin tests were carried out in 1985 and 1987 on two groups of school children in the city of Rio de Janeiro. Group A consisted of 449 children residing in the Jacarepagua district, in areas where transmission of human and canine American cutaneous leishmaniasis (ACL) has been high; this group was considered to be the one at greatest risk of acquiring the infection through L. braziliensis. Group B consisted of 282 children from Bonsucesso, a suburb of Rio de Janeiro that is at a considerable distance from any area where ACL is endemic; this was a lowest risk group, and was thus used as a control. Analysis of the cutaneous test results showed that in Group A, 8.9% of the sample tested positive, whereas in Group B the result was only 2.1%. In group A there were no significant differences in the proportion of positives when analysed according to sex, age and the year when the tests were carried out. A study of the effects associated with place of residence together with other variables was carried out using log-linear regression analysis. It showed that effects arising from place of residence were maintained; that this was the only significant effect; and that it was independent of other variables. The testing of school children using the Montenegro intradermal test was shown to be a useful procedure in the characterization of localities in which there is a risk of ACL infection.