Burden of Comorbidities Predicts 30-Day Rehospitalizations in Young Adult Medicare Beneficiaries With Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a systemic autoimmune rheumatic disease associated with premature mortality and multimorbidity.1,2It predominately affects young adult females and disproportionately affects racial/ethnic minority groups and individuals with lower socioeconomic status.3,4

Hydroxychloroquine Dose and Risk for Incident Retinopathy : A Cohort Study

BACKGROUND

Hydroxychloroquine is recommended for all patients with systemic lupus erythematosus and is often used for other inflammatory conditions, but a critical long-term adverse effect is vision-threatening retinopathy.

OBJECTIVE

To characterize the long-term risk for incident hydroxychloroquine retinopathy and examine the degree to which average hydroxychloroquine dose within the first 5 years of treatment predicts this risk.

DESIGN

Cohort study.

SETTING

U.S. integrated health network.

PARTICIPANTS

All patients aged 18 years or older who received hydroxychloroquine for 5 or more years between 2004 and 2020 and had guideline-recommended serial retinopathy screening.

MEASUREMENTS

Hydroxychloroquine dose was assessed from pharmacy dispensing records. Incident hydroxychloroquine retinopathy was assessed by central adjudication of spectral domain optical coherence tomography with severity assessment (mild, moderate, or severe). Risk for hydroxychloroquine retinopathy was estimated over 15 years of use according to hydroxychloroquine weight-based dose (>6, 5 to 6, or ≤5 mg/kg per day) using the Kaplan-Meier estimator.

RESULTS

Among 3325 patients in the primary study population, 81 developed hydroxychloroquine retinopathy (56 mild, 17 moderate, and 8 severe), with overall cumulative incidences of 2.5% and 8.6% at 10 and 15 years, respectively. The cumulative incidences of retinopathy at 15 years were 21.6% for higher than 6 mg/kg per day, 11.4% for 5 to 6 mg/kg per day, and 2.7% for 5 mg/kg per day or lower. The corresponding risks for moderate to severe retinopathy at 15 years were 5.9%, 2.4%, and 1.1%, respectively.

LIMITATION

Possible misclassifications of dose due to nonadherence to filled prescriptions.

CONCLUSION

In this large, contemporary cohort with active surveillance retinopathy screening, the overall risk for hydroxychloroquine retinopathy was 8.6% after 15 years, and most cases were mild. Higher hydroxychloroquine dose was associated with progressively greater risk for incident retinopathy.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Hydroxychloroquine Dose per Ophthalmology Guidelines and the Risk of Systemic Lupus Erythematosus Flares

This study of an academic medical center patient cohort with systemic lupus erythematosus (SLE) investigates the association between hydroxychloroquine dose based on current guidelines and risk of lupus flares.

Exploration of machine learning methods to predict systemic lupus erythematosus hospitalizations

OBJECTIVES

Systemic lupus erythematosus (SLE) is a heterogeneous disease characterized by disease flares which can require hospitalization. Our objective was to apply machine learning methods to predict hospitalizations for SLE from electronic health record (EHR) data.

METHODS

We identified patients with SLE in a longitudinal EHR-based cohort with ≥2 outpatient rheumatology visits between 2012 and 2019. We applied multiple machine learning methods to predict hospitalizations with a primary diagnosis code for SLE, including decision tree, random forest, naive Bayes, logistic regression, and an ensemble method. Candidate predictors were derived from structured EHR features, including demographics, laboratory tests, medications, ICD-9/10 codes for SLE manifestations, and healthcare utilization. We used two approaches to assess these variables over longitudinal follow-up, including the incorporation of lagged features to capture changes over time of clinical data. The performance of each model was evaluated by overall accuracy, the F statistic, and the area under the receiver operator curve (AUC).

RESULTS

We identified 1996 patients with SLE. 4.6% were hospitalized for SLE in their most recent year of follow-up. Random forest models had highest performance in predicting SLE hospitalizations, with AUC 0.751 and AUC 0.772 for two approaches (averaging and progressive), respectively. The leading predictors of SLE hospitalizations included dsDNA positivity, C3 level, blood cell counts, and inflammatory markers as well as age and albumin.

CONCLUSION

We have demonstrated that machine learning methods can predict SLE hospitalizations. We identified key predictors of these events including known markers of SLE disease activity; further validation in external cohorts is warranted.

Increased Risk of COVID-19 in Patients With Rheumatoid Arthritis: A General Population-Based Cohort Study

OBJECTIVE

Patients with rheumatoid arthritis (RA) are at an increased risk of acquiring infections owing to immunologic dysfunction and use of potent immunomodulatory medications; however, few data are available on their risk of COVID-19. We estimated the rate of COVID-19 among RA participants and compared it with that of the general population.

METHODS

Using the Health Improvement Network, we identified RA patients before February 2020 and followed them to September 2020. We calculated the rate of COVID-19 among participants with RA and compared it with that of the general population using a Cox proportional hazards model, adjusting for potential confounders using overlap weighting of exposure score. We repeated the same analysis among participants with osteoarthritis, a nonautoimmune rheumatic disease, as a negative control exposure.

RESULTS

We identified 225 cases of suspected and confirmed COVID-19 among 17,268 RA patients, and 14,234 cases among 1,616,600 participants in the general population (1.4 versus 0.9/1,000 person-months), with the adjusted hazard ratio (HR_adj ) being 1.19 (95% confidence interval [95% CI] 1.04-1.36). Confirmed COVID-19 cases developed in 46 RA participants and in 2,249 in the general population (0.3 versus 0.1/1,000 person-months), with the HR_adj being 1.42 (95% CI 1.01-1.95). No statistically significant difference was observed for suspected and confirmed (HR 1.00 [95% CI 0.93-1.07]) or confirmed (HR 1.08 [95% CI 0.92-1.27]) COVID-19 rates between participants with osteoarthritis and the general population.

CONCLUSION

RA, but not osteoarthritis, was associated with an increased risk of COVID-19. Our findings provide timely evidence to support recommendations that booster vaccines and priority access to anti-SARS-CoV-2 monoclonal antibody treatments should be encouraged for RA patients.

SCARF1-Induced Efferocytosis Plays an Immunomodulatory Role in Humans, and Autoantibodies Targeting SCARF1 Are Produced in Patients with Systemic Lupus Erythematosus

Deficiency in the clearance of cellular debris is a major pathogenic factor in the emergence of autoimmune diseases. We previously demonstrated that mice deficient for scavenger receptor class F member 1 (SCARF1) develop a lupus-like autoimmune disease with symptoms similar to human systemic lupus erythematosus (SLE), including a pronounced accumulation of apoptotic cells (ACs). Therefore, we hypothesized that SCARF1 will be important for clearance of ACs and maintenance of self-tolerance in humans, and that dysregulation of this process could contribute to SLE. In this article, we show that SCARF1 is highly expressed on phagocytic cells, where it functions as an efferocytosis receptor. In healthy individuals, we discovered that engagement of SCARF1 by ACs on BDCA1+ dendritic cells initiates an IL-10 anti-inflammatory response mediated by the phosphorylation of STAT1 and STAT3. Unexpectedly, there was no significant difference in SCARF1 expression in samples of patients with SLE compared with healthy donor samples. However, we detected anti-SCARF1 autoantibodies in 26% of patients with SLE, which was associated with dsDNA Ab positivity. Furthermore, our data show a direct correlation of the levels of anti-SCARF1 in the serum and defects in the removal of ACs. Depletion of Ig restores efferocytosis in SLE serum, suggesting that defects in the removal of ACs are partially mediated by SCARF1 pathogenic autoantibodies. Our data demonstrate that human SCARF1 is an AC receptor in dendritic cells and plays a role in maintaining tolerance and homeostasis.

Coronavirus disease 2019 outcomes among patients with rheumatic diseases 6 months into the pandemic

OBJECTIVE

In earlier studies, patients with rheumatic and musculoskeletal disease (RMD) who got infected with COVID-19 had a higher risk of mechanical ventilation than comparators. We sought to determine COVID-19 outcomes among patients with RMD 6 months into the pandemic.

METHODS

We conducted a cohort study at Mass General Brigham in Boston, Massachusetts, of patients with RMD matched to up to five comparators by age, sex and COVID-19 diagnosis date (between 30 January 2020 and 16 July 2020) and followed until last encounter or 18 August 2020. COVID-19 outcomes were compared using Cox regression. Risk of mechanical ventilation was compared in an early versus a recent cohort of patients with RMD.

RESULTS

We identified 143 patients with RMD and with COVID-19 (mean age 60 years; 76% female individuals) and 688 comparators (mean age 59 years; 76% female individuals). There were no significantly higher adjusted risks of hospitalisation (HR: 0.87, 95% CI: 0.68-1.11), intensive care unit admission (HR: 1.27, 95% CI: 0.86-1.86), or mortality (HR: 1.02, 95% CI: 0.53-1.95) in patients with RMD versus comparators. There was a trend towards a higher risk of mechanical ventilation in the RMD cohort versus comparators, although not statistically significant (adjusted HR: 1.51, 95% CI: 0.93-2.44). There was a trend towards improvement in mechanical ventilation risk in the recent versus early RMD cohort (10% vs 19%, adjusted HR: 0.44, 95% CI: 0.17-1.12).

CONCLUSIONS

Patients with RMD and comparators had similar risks of poor COVID-19 outcomes after adjusting for race, smoking and comorbidities. The higher risk of mechanical ventilation in the early RMD cohort was no longer detected in a recent cohort, suggesting improved management over time.

In vivo ultrasound and biometric measurements predict the empty body chemical composition in Nellore cattle

Evaluation of the body chemical composition of beef cattle can only be measured postmortem and those data cannot be used in real production scenarios to adjust nutritional plans. The objective of this study was to develop multiple linear regression equations from in vivo measurements, such as ultrasound parameters [backfat thickness (uBFT, mm), rump fat thickness (uRF, mm), and ribeye area (uLMA, cm2)], shrunk body weight (SBW, kg), age (AG, d), hip height (HH, m), as well as from postmortem measurements (composition of the 9th to 11th rib section) to predict the empty body and carcass chemical composition for Nellore cattle. Thirty-three young bulls were used (339 ± 36.15 kg and 448 ± 17.78 d for initial weight and age, respectively). Empty body chemical composition (protein, fat, water, and ash in kg) was obtained by combining noncarcass and carcass components. Data were analyzed using the PROC REG procedure of SAS software. Mallows' Cp values were close to the ideal value of number of independent variables in the prediction equations plus one. Equations to predict chemical components of both empty body and carcass using in vivo measurements presented higher R2 values than those determined by postmortem measurements. Chemical composition of the empty body using in vivo measurements was predicted with R2 > 0.73. Equations to predict chemical composition of the carcass from in vivo measurements showed R2 lower (R2< 0.68) than observed for empty body, except for the water (R2 = 0.84). The independent variables SBW, uRF, and AG were sufficient to predict the fat, water, energy components of the empty body, whereas for estimation of protein content the uRF, HH, and SBW were satisfactory. For the calculation of the ash, the SBW variable in the equation was sufficient. Chemical compounds from components of the empty body of Nellore cattle can be calculated by the following equations: protein (kg) = 47.92 + 0.18 × SBW - 1.46 × uRF - 30.72 × HH (R2 = 0.94, RMSPE = 1.79); fat (kg) = 11.33 + 0.16 × SBW + 2.09 × uRF - 0.06 × AG (R2 = 0.74, RMSPE = 4.18); water (kg) = - 34.00 + 0.55 × SBW + 0.10 × AG - 2.34 × uRF (R2 = 0.96, RMSPE = 5.47). In conclusion, the coefficients of determination (for determining the chemical composition of the empty body) of the equations derived from in vivo measures were higher than those of the equations obtained from rib section measurements taken postmortem, and better than coefficients of determination of the equations to predict the chemical composition of the carcass.

The Effect of Statin Use on Mortality in Systemic Autoimmune Rheumatic Diseases

OBJECTIVE

Systemic autoimmune rheumatic diseases (SARD) are associated with an increased risk of premature cardiovascular disease (CVD) and all-cause mortality. We examined the potential survival benefit of statin use among patients with SARD in a general population setting.

METHODS

We conducted an incident user cohort study using a UK general population database. Our population included patients with a SARD as determined by Read code diagnoses of systemic lupus erythematosus, systemic sclerosis, Sjögren syndrome, dermatomyositis, polymyositis, mixed connective tissue disease, Behçet disease, or antineutrophil cytoplasmic antibodies-associated vasculitis between January 1, 2000, and December 31, 2014. We compared propensity score-matched cohorts of statin initiators and noninitiators within 1-year cohort accrual blocks to account for potential confounders, including disease duration, body mass index, lifestyle factors, comorbidities, and medication use.

RESULTS

Of 2305 statin initiators, 298 died during the followup period (mean 5.1 yrs), whereas among 2305 propensity score-matched noninitiators, 338 died during the followup period (mean 4.8 yrs). This corresponded to mortality rates of 25.4/1000 and 30.3/1000 person-years, respectively. Statin initiation was associated with reduced all-cause mortality (HR 0.84, 95% CI 0.72-0.98). When we compared the unmatched cohorts, the statin initiators (n = 2863) showed increased mortality (HR 1.85, 95% CI 1.58-2.16) compared with noninitiators (n = 2863 randomly selected within 1-year cohort accrual blocks) because of confounding by indication.

CONCLUSION

In this general population-based study, statin initiation was shown to reduce overall mortality in patients with SARD after adjusting for relevant determinates of CVD risk.

Hydroxychloroquine prescription trends and predictors for excess dosing per recent ophthalmology guidelines

Background

Hydroxychloroquine (HCQ) retinopathy may be more common than previously recognized; recent ophthalmology guidelines have revised recommendations from ideal body weight (IBW)-based dosing to actual body weight (ABW)-based dosing. However, contemporary HCQ prescribing trends in the UK remain unknown.

Methods

We examined a UK general population database to investigate HCQ dosing between 2007 and 2016. We studied trends of excess HCQ dosing per ophthalmology guidelines (defined by exceeding 6.5 mg/kg of IBW and 5.0 mg/kg of ABW) and determined their independent predictors using multivariable logistic regression analyses.

Results

Among 20,933 new HCQ users (78% female), the proportions of initial HCQ excess dosing declined from 40% to 36% using IBW and 38% to 30% using ABW, between 2007 and 2016. Among these, 47% of women were excess-dosed (multivariable OR 12.52; 95% CI 10.99–14.26) using IBW and 38% (multivariable OR 1.98; 95% CI,1.81–2.15) using ABW. Applying IBW, 37% of normal and 44% of obese patients were excess-dosed; however, applying ABW, 53% of normal and 10% of obese patients were excess-dosed (multivariable ORs = 1.61 and 0.1 (reference = normal); both p < 0.01). Long-term HCQ users showed similar excess dosing.

Conclusion

A substantial proportion of HCQ users in the UK, particularly women, may have excess HCQ dosing per the previous or recent weight-based guidelines despite a modest decline in recent years. Over half of normal-BMI individuals were excess-dosed per the latest guidelines. This implies the potential need to reduce dosing for many patients but also calls for further research to establish unifying evidence-based safe and effective dosing strategies.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1634-8) contains supplementary material, which is available to authorized users.

Sharp decline in hydroxychloroquine dosing-analysis of 17,797 initiators from 2007 to 2016

We aimed to assess the impact of ophthalmology weight-based hydroxychloroquine (HCQ) dosing guidelines on prescribing patterns. We examined initial HCQ prescription dosing between 2007 and 2016 and determined independent predictors for HCQ dosing above the previous (2011) recommended ≤ 6.5 mg/kg of ideal body weight (IBW)/day and the latest (2016) recommended ≤ 5.0 mg/kg of actual body weight (ABW)/day using logistic regression. Among 17,797 patients (82% female), the proportion of 400 mg prescribed daily dosing declined sharply from 80% in 2007-2011 to nearly 40% in 2014, whereas the proportions of 200- and 300-mg daily doses showed the opposite trends during the same periods. Accordingly, the risk of HCQ dosing above the guideline recommendations declined by more than 60%. While 36% of normal body mass index (BMI) individuals were classified as dosing above the IBW-based guideline, 66% would have received dosing above the latest ABW-based guideline. The risk of excess dosing was associated with female patients and dermatology prescribers (adjusted odds ratios ≥ 2 according to IBW- or ABW-based guidelines). There has been a sharp decline in HCQ dosing following ophthalmology weight-based guidelines in recent years. While this trend is likely helpful in reducing the risk of retinopathy, its potential impact on HCQ efficacy remains to be clarified.

Unchanging premature mortality trends in systemic lupus erythematosus: a general population-based study (1999-2014)

Objective

Patients with SLE have increased morbidity and premature mortality. Whether this mortality gap has improved in recent years, as in RA, is unknown.

Methods

We conducted a population-based cohort study using a medical records database representative of the general population of the UK. We identified incident SLE cases and matched non-SLE controls between 1999 and 2014, divided into two subgroups based on year of SLE diagnosis, forming the early cohort (1999-2006) and late cohort (2007-14). We compared the mortality rates and hazard ratios, adjusting for potential confounders.

Results

We identified 1470 and 1666 incident SLE cases in the early and late cohorts, respectively. In both cohorts, SLE patients had similar levels of excess mortality compared with their matched comparators [15.9 vs 7.9 deaths/1000 person-years (PY) in the early cohort and 13.8 vs 7.0 deaths/1000 PY in the late cohort]. The corresponding mortality hazard ratios were 2.15 (95% CI 1.63, 2.83) and 2.12 (95% CI 1.61, 2.80) in the early and late cohorts, respectively (P-value for interaction = 0.95). The absolute mortality differences were 8.0 (95% CI 4.3, 11.8) and 6.8 (95% CI 3.5, 10.0) deaths/1000 PY, respectively (P-value for interaction = 0.61).

Conclusion

This general population-based cohort study suggests that excess mortality has not improved among SLE patients in recent years, remaining greater than double that of comparators, unlike RA during the same period. This highlights a critical unmet need for the development of new therapeutic agents and improved management strategies for SLE and its comorbidities.

Statin use and mortality in gout: A general population-based cohort study

OBJECTIVES

Gout is associated with a higher risk of cardiovascular disease and premature mortality. We examined the potential survival benefit of statin use among gout patients in the general population.

METHODS

We performed an incident user cohort study with time-stratified propensity score matching using a database representative of the UK general population between January 1999 and December 2014. To account for potential confounders, we compared propensity score-matched cohorts of statin initiators and non-initiators within 1-year cohort accrual blocks. We estimated the hazard ratio (HR) for mortality using a Cox proportional hazard model and the mortality rate difference using an additive hazard model. We examined potential subgroup effects stratified by key factors, including circulatory disease history.

RESULTS

Among 17,018 statin initiators, 2025 deaths occurred during the follow-up (mean = 5.0 years) with a mortality rate of 24.0/1000 person-years (PY). The number of deaths and all-cause mortality rate among matched comparators during the follow-up (mean = 4.6 years) were 2503 and 31.7/1000 PY respectively. Compared with non-initiators, statin initiators experienced a 16% lower relative risk of all-cause mortality (HR = 0.84, 95% CI: 0.79-0.89) and 7.7 (95% CI: 6.1-9.3) fewer deaths per 1000 PY. This protective association was stronger among those without prior circulatory disease (HRs = 0.65 vs. 0.85; p for interaction = 0.02).

CONCLUSION

In this general population-based cohort study, statin initiation was associated with a lower risk of mortality in gout, potentially with greater benefits among those without prior circulatory disease. The proper use of statins may help to substantially improve the premature mortality in gout.

Impacts of temperament on Nellore cattle: physiological responses, feedlot performance, and carcass characteristics

Forty-four feedlot-finished Nellore cattle were used to evaluate the impacts of temperament on performance, meat and carcass traits, and serum concentrations of hormones, proteins, enzymes, and immunoglobulins. Individual temperament was assessed at feedlot entry (d 0), 67 d, and 109 d, utilizing chute score (CS; 5-point scale) and exit velocity (EV). Temperament scores were calculated averaging CS and EV scores, and cattle were subsequently classified according to their temperament (an average of ≤3 = adequate temperament [ADQ], or an average of >3 = excitable temperament [EXC]). At the end of the experiment (d 109), all 44 animals were slaughtered, and 16 were randomly selected for final empty body weight (EBW) estimation. Blood samples were collected at 0, 67, and 109 d and analyzed for serum variables (cortisol, insulin, haptoglobin, total protein, lactate, creatinine kinase [CK], lactate dehydrogenase [LDH], and IgA). The incidence of carcass bruises was verified immediately after the hide was removed. Carcass pH was obtained at 0 and 24 h postmortem. Samples of the LM were collected for meat quality analyses. Cattle classified as ADQ had greater final BW ( = 0.03), final EBW ( = 0.02), metabolic weight ( = 0.03), ADG ( = 0.02), feed efficiency ( = 0.03), HCW ( = 0.02), cold carcass weight ( = 0.02), and LM area ( < 0.01) compared to that of the EXC cohorts. Cattle classified as ADQ tended to have a lower percentage of cooler shrink ( = 0.06) compared to that of EXC cattle. No temperament effects were detected for initial BW ( = 0.70), DMI ( = 0.14), cold dressing percentage ( = 0.98), or backfat thickness ( = 0.29). Cattle classified as ADQ had greater marbling ( = 0.02) and meat fat content ( = 0.05) compared with that of EXC cattle. No temperament effects ( > 0.05) were detected for unsaturated fatty acid (UFA), SFA, MUFA, PUFA, and n-6:n-3 ratio. For blood parameters, EXC cattle had greater values of cortisol ( = 0.04) and haptoglobin ( = 0.05) and tended ( = 0.06) to have reduced serum insulin concentration compared with ADQ cattle. Both temperament groups had similar serum concentrations of IgA ( = 0.25) and total protein ( = 0.84). Cattle classified as EXC presented greater amounts ( = 0.05) of carcass bruises. In conclusion, an EXC temperament impaired feedlot performance, carcass characteristics, and meat quality traits in finishing Nellore cattle.

Growth curves of carcass traits obtained by ultrasonography in three lines of Nellore cattle selected for body weight

The effect of selection for postweaning weight was evaluated within the growth curve parameters for both growth and carcass traits. Records of 2404 Nellore animals from three selection lines were analyzed: two selection lines for high postweaning weight, selection (NeS) and traditional (NeT); and a control line (NeC) in which animals were selected for postweaning weight close to the average. Body weight (BW), hip height (HH), rib eye area (REA), back fat thickness (BFT), and rump fat thickness (RFT) were measured and records collected from animals 8 to 20 (males) and 11 to 26 (females) months of age. The parameters A (asymptotic value) and k (growth rate) were estimated using the nonlinear model procedure of the Statistical Analysis System program, which included fixed effect of line (NeS, NeT, and NeC) in the model, with the objective to evaluate differences in the estimated parameters between lines. Selected animals (NeS and NeT) showed higher growth rates than control line animals (NeC) for all traits. Line effect on curves parameters was significant (P < 0.001) for BW, HH, and REA in males, and for BFT and RFT in females. Selection for postweaning weight was effective in altering growth curves, resulting in animals with higher growth potential.

Non-operative management of symptomatic cholelithiasis in pregnancy is associated with frequent hospitalizations

Symptomatic cholelithiasis (SC) is common in pregnancy. Guidelines recommend laparoscopic cholecystectomy (LC) for SC in pregnancy. Our aim was to evaluate current practice patterns and outcomes for patients undergoing initial non-operative management for uncomplicated SC during pregnancy. We performed a retrospective analysis and telephone survey of all patients presenting in a 42-month period to a tertiary care center for uncomplicated SC during pregnancy. Women with complicated gallstone disease, including cholecystitis, pancreatitis, choledocholithiasis, and cholangitis were excluded. We identified 53 patients with uncomplicated SC during pregnancy. LC was performed in 4 (7.5%) antepartum and in 28 (51.7%) postpartum. The majority of LCs (21, 75%) were performed within 3 months postpartum. Of those with postpartum LC, 22 (78.6%) had recurrent postpartum symptoms prior to LC, and 14 (50%) had repeat hospitalizations prior to undergoing surgery. Given the safety of antepartum LC and the frequency of recurrent symptoms and hospitalizations, early surgical intervention during pregnancy may be the optimal strategy to reduce antepartum and early postpartum admissions for uncomplicated SC.

Serological profile of buffalo (Bubalus bubalis) female calves vaccinated with standard Brucella abortus strain 19 vaccine using rose bengal, 2-mercaptoethanol and complement fixation tests

The serological profiles of 21 female buffaloes vaccinated between 3 and 8 months of age using Brucella abortus strain 19 (S19) were evaluated by rose bengal (RBT), 2-mercaptoethanol (2ME) and complement fixation (CFT) tests. The serum strains were collected in day zero, 15, 30, 45, 60th days and subsequently to each 30 months, until 720th day after vaccination. No animal showed reaction in day zero. In 15th day above 95% of animals revealed reaction in all tests. All the animals presented absence of reactions in CFT, RBT and 2ME tests at 270, 300 and 360 days after vaccination, respectively. Our finding highlighted early response in CFT compared than other conventional agglutination tests. None of animals presented oscillation of titers or reactions in any test after 360 day of study, which enables the use of these tests after this period without interference of antibodies from S19 vaccine origin between 3 and 8 months in buffalo heifers.

Muscle fiber type characterization and myosin heavy chain (MyHC) isoform expression in Mediterranean buffaloes

This study aimed to evaluate myosin heavy chain (MyHC) isoform expression and muscle fiber types of Longissimus dorsi (LD) and Semitendinosus (ST) in Mediterranean buffaloes and possible fibers muscles modulation according to different slaughter weights. The presence of MyHC IIb isoforms was not found. Only three isoforms of MyHC (IIa, IIx/d and I) were observed and their percentages did not vary significantly among slaughter weights. The confirmation of the presence of hybrid muscles fibers (IIA/X) in LD and ST muscles necessitated classifying the fiber types into fast and slow according to their contractile activity, by m-ATPase assay. For both muscles, the muscle fiber frequency was higher for fast than for slow fibers in all weight groups. There was a difference (P<0.05) in the frequency of LD and ST muscle fiber types according to slaughter weights, which demonstrate that the slaughter weight influences the profile of muscle fibers from buffaloes.

[The effect of chromium picolinate on the liver levels of trace elements]

Chromium picolinate has been implicated as a lipid and carbohydrate reducing agent, and therefore it may be a valuable adjunct to the treatment and prevention of diabetes and heart disease. This compound is inexpensive and apparently nontoxic. In this work, we have determined the influence of its administration (100, 200, 500 micrograms Cr/ml, for 7 and 21 days) on hepatic content of Zn, Mn, Cu and Fe of male Wistar rats. The results show a variation of the levels of these elements after the administration of chromium picolinate, although the differences are only significantly (p < 0.01) in the case of Mn. This influence is dose-dependent, occurring a decrease of 72% in the group treated with 500 micrograms/ml (Pic-500) respect to the content of control group.