This study evaluates the impact of the COVID-19 pandemic on healthcare workers in Argentina, during the second wave in 2021. The aim is to assess stress, burnout, and anxiety levels, incorporating the assessment of hair cortisol levels as a biomarker of chronic stress. A total of 496 healthcare workers from three different hospitals were included in this study. Two of these hospitals depend on the Buenos Aires City Ministry of Health and the third hospital belongs to Buenos Aires University. Hair samples were obtained using scissors from the posterior vertex, as close to the scalp as possible. Each sample was weighed, and cortisol was extracted and then measured using an automated chemiluminescent method. Notably, 10% of the population exhibited hair cortisol levels above 128 pg/mg. Anxiety scores surpassed medians for 38%, 52%, and 39% of healthcare workers at Argerich, Clínicas, and Durand Hospitals, respectively. Associations were found between high hair cortisol levels and age, workload, emotional exhaustion, and depersonalization. In addition, burnout, identified in 11% of participants, correlated with higher perceived stress, lower social support, and higher anxiety scores. Binary logistic regression revealed associations between burnout and perceived stress, anxiety, and age. Finally, mediation analysis showed depersonalization as a mediating variable in the relationship between hair cortisol concentration and emotional exhaustion. In conclusion, this study highlights the complex relationships between anxiety, stress, cortisol levels, and burnout. Prioritizing interventions and research is essential to support the well-being of frontline healthcare professionals, ensuring their resilience during challenging times.

INTRODUCTION:Molecular alterations in follicular cells in the BRAF or NRAS genes have been reported to be associated with the process of carcinogenesis. Our aim was to determine the mutational frequency of BRAF and NRAS in fine-needle aspiration (FNA) specimens in our population.METHODS:The mutational status of BRAF (codon 600) and NRAS (codon 61) was analysed by qPCR in 193 FNA specimens from suspicious nodules and compared with pathological data of 115 patients.RESULTS:BRAF mutation was identified in 40 samples (74.1%) of FNAs classified as Bethesda VI (n = 54). In samples histologically diagnosed as classic papillary thyroid carcinoma (cPTC, n = 47), mutation was observed in 70% of cases, while in other subtypes the prevalence was lower (p = 0.013). In FNA specimens of follicular lesions (n = 36), positivity for NRAS was found in 50% of the follicular carcinomas (FTCs), but only in 6.7% of adenomas. Finally, there was a significant correlation between BRAF and PTC with lymph-node metastasis (p = 0.014) and increased relative risk of recurrence based on the Argentine Intersociety Consensus (RR = 6.77, p = 0.022). No significant differences were found between BRAF mutation and other features of aggressiveness in PTC.CONCLUSION:BRAF and NRAS mutations are observed in a significant number of PTCs and FTCs, in our population. There is a significant correlation between BRAF mutation and lymph-node metastasis.

Abstract   It is known that thyroid cancer initiation and progression occurs because of gradual accumulation of genetic and epigenetic alterations at cell level. Many mutations associated with this disease have been reported to be present in genes encoding proteins in the mitogen-activated protein kinase (MAPK) signaling pathway, specifically BRAF and RAS genes, as well as in the PI3K/Akt signaling pathway, among others. In particular, molecular alterations in follicular cells in the BRAF or NRAS genes have been reported to be associated with the process of carcinogenesis. Previously we found BRAF and NRAS mutations are observed in a significant number of papillary and follicular thyroid carcinomas in our population, respectively. In this study, we tested the diagnostic performance of BRAF and NRAS mutation in thyroid carcinoma in fine-needle aspiration (FNA) specimens with indeterminate cytology. In total, residual material from 73 FNA samples was used (n= 16, Bethesda III; n=48, Bethesda IV and n=9 Bethesda V). BRAF codon 600 mutation and NRAS codon 61 mutations were investigated using qPCR and melting curve analysis was carried out. Diagnosis of malignancy was confirmed by histology on paired surgical specimen in 54 cases. Results In the cytologically indeterminate categories, 9.6% of specimens were BRAF V600 mutated: 1 of 16 were subcategorized as atypia of undetermined significance or follicular lesion of undetermined significance (6.3%); 2 of 48 as follicular neoplasm or suspicious for follicular neoplasm (4.1%); and 4 of 9 as suspicious for malignancy (44.4%). NRAS Q61 mutation was found in 4 patients (2 with Bethesda IV and 2 with cytology V). The BRAF V600 mutations were associated with carcinoma in 100% of cases (n = 7), whereas only 75% (n = 3) of the nodules with NRAS were associated with carcinoma. BRAF V600 and NRAS Q61 mutations had high specificity in predicting malignant carcinoma (96.8%); the sensitivity was 43.5% with a positive predictive value of 90.9% and a negative predictive value of 69.8%. In specific categories of indeterminate cytology, the pre-test risk of malignancy was 38%, 33% and 88% while the post molecular test risk of malignancy was 100%, 75% and 100% respectively. Conclusions BRAF V600 and NRAS Q61 molecular test in residual FNA samples improve diagnostic accuracy of the cytology analysis in our population and may help to better select patients for avoid inadequate or unnecessary surgeries. Presentation: No date and time listed

Background: Benefits of early Cystic Fibrosis (CF) detection using newborn screening (NBS) lead to widespread use in NBS programs. Since 2002, a two-stage immunoreactive trypsinogen (IRT/IRT) screening strategy has been used as CFNBS method in all public maternities in the City of Buenos Aires, Argentina. However, novel screening strategies may be more efficient. The aim of the study is to prospectively compare two CFNBS strategies, IRT/IRT and IRT/PAP (pancreatitis-associated protein). Methods: A two-year prospective study was performed. IRT was measured in dried blood samples collected 48–72 hours after birth. When IRT value was abnormal, PAP was determined, and a second visit was scheduled to obtain another sample for IRT before 25 days of life. Newborns with a positive CFNBS were referred for confirmatory sweat test. Results: There were 69,827 births in the City of Buenos Aires during the period studied; 918 (1.31%) had an abnormal IRT. A total of 207 children (22.5%) failed to return for the second IRT, but only two PAP (0.2%) were not performed. IRT/IRT was more likely to lead to a referral for sweat testing than IRT/PAP (OR 2.3 [95% CI 1.8;2.9], p<0.001). Sensitivity, specificity, positive predictive value, and negative predictive value were: 80% and 100%, 86.5% and 82.6%, 4.04% and 4.2%, 99.84% and 100% for IRT/IRT and IRT/PAP strategies, respectively. Conclusion: The IRT/PAP strategy is more sensitive than IRT/IRT; it avoids a second appointment and the need of unnecessary sweat testing, and decreases loss to follow up in our population.

Abstract Pregnancy is associated with a physiological GH excess, where maternal pituitary GH is suppressed by effect of placental GH on the hepatic receptor, increasing IGF-1 serum levels1. However, it is also described that estrogens and progesterone are responsible for reduction in IGF-1 by direct hepatic action through the inhibition of the JAK-STAT pathway that results in GH resistance, being more clear at the beginning of pregnancy.2 Acromegaly is a rare disorder in which GH axis is deregulated and IGF-1 is the most reliable biochemical marker for diagnosis and monitoring. It is know that secondary hypogonadism associated with these pathology decreases fertility rates. Nonetheless, improvement of acromegaly treatment and greater access to assisted reproductive technology increase pregnancy rates in this population. The follow-up of pregnant acromegalic women acquires relevance for the comorbidities of this association and depends on the adequate interpretation of the IGF-1 values. Then, due to changes in concentration and action of IGF-1 during pregnancy3, it is important that each laboratory establish their specific reference values. For that reason we analyzed serum samples from 80 healthy pregnant women living in the Metropolitan Area of Buenos Aires (AMBA): 22 were in the 1st trimester (1T), 29 in the 2nd (2T) and 29 in the 3rd (3T). All women were between 30 and 40 years old, had no endocrinopathies or metabolic diseases. Serum IGF-1 was measured by Immulite 2000 Siemens, and Prism8 GraphPad was used for statistical analysis, calculating ranges for each trimester defined as 2,5 and 97,5 percentiles. Ranges obtained were: 64,5-165,0 ng/ml, 78,9-201,0 ng/ml and 96,1-344,0 ng/ml for 1T, 2T and 3T, respectively. Significant differences were observed between 3T and the other trimesters (1T and 2T). We also compared these ranges with our reference values from healthy non-pregnant women in the same age, and found that 3T has significantly higher values ​​of IGF-1 (55,8-188,4 ng/ml vs. 96,1-344,0 ng/ml respectively). In conclusion, IGF-1 levels during the first two trimesters of pregnancy remain within the normal range, and there is a significant increase during the third trimester. Given that IGF-1 plays an essential role during pregnancy, it is important to report ranges in healthy pregnant women to contribute in the follow-up of patients with acromegaly who get pregnant. Although our results are in agree with the available literature, it is necessary to increase the number of healthy pregnant women to establish reference values of IGF-1. 1Frankenne et al (1988). The physiology of growth hormones in pregnant women and partial characterization of the placental GH variant. Journal of Clinical Endocrinology and Metabolism 66:1171-1180 2Leung et al (2004). Estrogen regulation of growth hormone action. Endocrine Reviews 25:693-72 3Muhammad et al (2017). Pregnancy and acromegaly. Pituitary 20:179-184

The diagnostic procedure for the evaluation of Cushing’s syndrome is performed by any of the following biochemical tests: urine free cortisol, salivary cortisol at 11 pm and serum cortisol post 1 mg of dexamethasone. Collection of saliva samples is simple and noninvasive, thus being a method of choice for the evaluation of risk populations. The aim of this work is to analyze the performance of an automated chemiluminescent method for measurement of salivary cortisol at 11 pm according to the new quality guidelines and assess its clinical utility. Cortisol levels were measured in samples obtained by passive drooling from 32 healthy subjects and 9 patients with Cushing’s syndrome. Matrix effect, linearity, limit of blank, limit of quantitation, recovery and diagnostic performance were assessed. The Unicel 600 DXI Access Beckman Coulter chemiluminescent automated analyzer was used. The standard curve provided by the manufacturer was adapted to measure cortisol concentrations in saliva. Matrix effect: equation of the curve using salivary matrix: y=-1.824x+3.491 (95% CI=-2.068 to -1.582) vs. Equation of the curve using diluent matrix: y=-1.833x+3.394 (95% CI=-1.961 to -1.704). There is overlapping of both curves. Linearity: linear assay between 1.8 nmol/L and 108.0 nmol/L. Limit of blank: 0.1 nmol/L. Limit of quantitation: 1.8 nmol/L (TAE of 25%). Recovery: standard cortisol solution concentration 5 nmol/L: 102%; 10 nmol/L: 107%; 40nmol/L: 115%. Diagnostic performance: median and ranges in healthy subjects: 2.0 nmol/L (<2.0-9.0 nmol/L); Cushing’s syndrome: 30.3 nmol/L (15.4-61.0 nmol/L). ROC curve cutoff value: 9.0 nmol/L (100% Specificity; 100% Sensitivity; AUC=1.00). The method used provides excellent analytical performance for cortisol measurement in saliva at 11 pm, which makes it a valuable biochemical tool both for screening populations at risk for Cushing’s syndrome and for the follow-up and diagnosis of this condition.

Chronic Kidney disease (CKD) is an important public health problem which is associated to an increase in mortality. An important diagnostic tool is the estimated glomerular filtration rate (GFR). The aims of this study were to compare GFR according to two different formulas: MDRD-4 and CKD-EPI, in order to evaluate its performance in clinically relevant values and to display occult chronic kidney disease (OCKD) according to each of the equations reviewed to classify the studied population into different stages of CKD. A total of 2526 patients with CKD-associated risk factors were analyzed. Mean of the results with both formulas were: 84.5 mL/min/1.73 m(2) for MDRD-4 and 90.9 mUmin/1.73 m(2) for CKD-EPI. Considering the associations between GFR in each of the stages and the results of blood creatinine, 83 patients were classified as OCKD by MDRD-4 while 23 were classified by MDRD-EPI; showing an underestimation of the GFR when using MDRD-EPI. The importance of this study lies in the early detection of the disease and in preventing the complications that could restrict the patient's well-being. The support of the networking laboratories brings the appropriate and low cost tools for an early assistance in search of security, care and education forthe patient.

Fil: Repetto, Esteban Martin. Universidad de Buenos Aires. Facultad de Farmacia y Bioquimica. Departamento de Bioquimica Clinica; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina

Resumen es: El primer paso para obtener seguridad en los resultados emitidos por el laboratorio clinico es confirmar que los procedimientos de medida utilizados tien...

The first step for safety in the results issued by the clinical laboratory is to confirm that all analytical measurement procedures have shown an acceptable analytical performance. A quality performance evaluation of automated hematology analyzer Beckman Coulter LH 750 was performed according to the quality requirements of our laboratory and manufacturer's specifications. The performance parameters evaluated by both manual and automatic mode were: carryover according to CLSI H26-A2 protocol; repeatability, intermediate precision and trueness according to CLSI EP15-A2 protocol and using BIO-RAD controls; linearity according to CLSI EP6-A protocol; quantification limits according to CLSI EP17-A2 protocol; and reference intervals according to CLSI EP28-A3C protocol. Data were analyzed using LinChecker and GraphPad5 programs. The tests performed complied with the requirements stipulated by the manufacturer and the quality requirements of our laboratory like minimal biological variability. Reference intervals for adult individuals were also checked. Consequently, performance evaluation of the automated hematology analyzer showed that the assessed laboratory parameters have acceptable performance.

BACKGROUND:Mucopolysaccharidosis type VI can be screened by measuring the lysosomal arylsulfatase B (ARSB) residual enzyme activity in dried blood spots (DBS) using synthetic substrates. However, we have found experimental obstacles when determining ARSB activity with the fluorescent method due to the significant quenching effect rendered by DBS components. METHODS:We adapted the methods originally described by Chamoles et al. [1] and Civallero et al. [2] and put forward 2 distinct approaches for ARSB activity quantification from DBS samples by measuring the 4-methylumbelliferone (β-MU) fluorescence generated from the ARSB 4-methylumbelliferone sulfate (β-MUS) substrate. RESULTS:We demonstrate the high throughput feasibility of a novel approach for measuring ARSB activities by incorporating tailor-made calibration curves according to each patient's DBS sample quenching properties. The second method is used to calculate ARSB activities by measuring the fluorescence and absorbance parameters in each reaction sample with a single DBS-free calibration curve. CONCLUSIONS:The quantitative correlation between the DBS sample absorbance and its quenching effect can be used to calculate predictive ARSB activities and would serve as an affordable first tier screening test. The method described herein demonstrates the critical importance of adapting the β-MU calibration curves to each patient's unique DBS sample matrix and its positive impact on the accuracy and reliability of ARSB activity measurements.

Objective: The objective of the study was to determine the prevalence of vitamin D insufficiency and its association with non-traditional cardiovascular disease (CVD) risk factors such as Apo B in South American Indian school children.Methods: A cross-sectional study of 355 children (166 Males) aged 9.6 +/- 23 y was performed. Anthropometric measures, glucose, lipids, insulin, Apo B, Apo A, and vitamin D concentrations were measured.Results: The prevalence of overweight and obesity was 10.7% (38) per CDC. One child (0.3%) had optimal vitamin D concentrations [25(OH)D[>30 ng/ml. Univariate analysis showed significant associations between vitamin D and HDL-C (r = 0.12 p < 0.05), age (r = -0.11 p < 0.05) BMI (r = -0.22 p < 0.05), LDL-C (r = -0.22 p < 0.01), triglycerides (r = -0.16 p < 0.01), non HDL-C (r = 0.21 p < 0.01), Apo B (r = -0.23 p < 0.01), Apo B/Apo A (r = -0.21 p < 0.01), insulin (r = -0.17 p < 0.05), and HOMA-IR (r = -0.16 p < 0.05). Multiple linear regression analysis showed that female gender and Apo B were significantly associated with vitamin D adjusted for confounding factors (R-2 0.12).Conclusion: Vitamin D deficiency was associated with increased Apo B among Indian children, suggesting that it could be used as a risk marker of CVD. (C) 2013 Elsevier B.V. All rights reserved.

Resumen es: El deporte exige de quienes lo practican una adaptacion, entrenamiento y buen estado fisico. El objetivo del trabajo fue estudiar en suero/plasma de indi...

BACKGROUND:Hypovitaminosis D is an international problem; however, there is little information about its prevalence in apparently healthy Indian children living at high altitudes. OBJECTIVES:To determine (i) the prevalence of hypovitaminosis D and (ii) the association of serum vitamin D with the risk factors for diabetes among Indian Koya children. METHODS:A cross-sectional study of 290 (129 males) school children aged 10.7 ± 2.9 yr was performed. Anthropometric measures, blood pressure (BP), Tanner stages and serum levels of glucose, lipids, and insulin were measured. 25-hydroxyvitamin D [25(OH)D] was measured by radioimmunoassay (Dia Sorin). RESULTS:The prevalence of obesity was 3.4% (10), overweight 3.4% (10), normal weight 79.0% (229), and underweight 14.1 % (41) per CDC reference standards. Concentrations of [25(OH)D] were median 10 (range 8-13 ng/mL); 10 (3.4%) had insufficient vitamin D levels (20 to <30 ng/mL), 136 (46.9%) had deficient levels (10 to <20 ng/mL), 144 (49.7%) had severe deficiency (<10 ng/mL) and none had optimal levels (≥30 ng/mL). There was an inverse significant correlation between [25(OH)D] and age (r = 0.14), body mass index (BMI) (r = 0.16), waist circumference (r = 0.15), systolic BP (r = 0.19), hemoglobin (r = 0.19), glucose (r = 0.22), insulin (r = 0.13), and homeostasis model of assessment-insulin resistance (r = 0.16). Multiple linear regression analysis showed that 25(OH)D concentrations were significantly and inversely associated with glucose concentrations (β = -0.28; p = 0.02) adjusted for age, BMI, systolic BP, hemoglobin, and insulin. CONCLUSIONS:This study demonstrated a high prevalence of both 25(OH)D deficiency and insufficiency and an inverse association between 25(OH)D and glucose concentration in apparently healthy Koya Indian children. Further research is needed to confirm these findings.

Sports demand from those who practice it, adaptation, training and a good physical condition. The objective of the work was to study in serum/plasma of trained people (elite football players, n=32) and untrained people (n=16) the clinical laboratory, haematological, and endocrinal profiles; 2) to relate the biochemical findings to sports physiopathology; 3) Assess the probable clinical implication of the results obtained. The results detained showe a significant decrease in hematocrit, iron, platelets and bilirrubin (physiological plasma expansion); magnesium (enzymatic consumption); proteins and glycemia (increase in energy metabolism and protein change). Without significant changes in endocrinological profile (decreased TSH, greater hormone efficiency); and lipid profile (increased HDL and decreased LDL; lipoprotein protector effect). Significant increase: calcium (more availability); urea (increased protein metabolism); and aldolase y creatinkinase (lysis of trained muscle fibre). Creatinkinase is the scoreboard of belonging to the elite group. It should be a different reference value for this group. - Thus, sport is object of study at the clinical laboratory; and implementation of the scientific knowledge in a practical and suitable manner enables the health professional to make relevant and right decisions.

RESUMEN Introduccion: La prevalencia de factores de riesgo de enfermedad cardiovascular (ECV) difiere en distinto grupos etnicos. Objetivos: Determinar a) la distribucion de lipidos, glucosa e insulina en ninos Koya y b) estimar la asociacion entre lipidos y BMI, tension arterial, hemoglobina e insulina. Metodos: En un estudio de diseno transversal se examinaron 330 ninos escolares (147 varones) cuya edad promedio fue de 9.5 + 2.0 anos. Se midieron el peso, la talla, la tension arterial, los niveles sericos de glucosa, lipidos y de insulina. La dislipemia fue definida segun criterios del NCEP (National Cholesterol Education Program standards) y de la AHA (American Heart Association). Resultados: La prevalencia de obesidad fue del 3.6% (12) y de sobrepeso de 4.5% (15) segun normas del CDC. El promedio de hemoglobina fue de 16.0+ 1.1 g/dL secundaria a la hipoxia por la altura. Los factores de riesgo de hipertrigliceridemia 29% (95) y bajo HDL-C 30% (99) fueron frecuentes mientras que de obesidad central 6.4% (21) fue infrecuente. Los modelos de regresion lineal multiple mostraron una asociacion significativa entre trigliceridos e insulina (beta = 4.74, p < 0.001) y HDL-C (beta = -2.54, p < 0.001) ajustado por factores confundidores. Asimismo, el HDL-C se asocio con trigliceridos (beta = -0.65, p < 0.001) y colesterol total (beta = 0.16, p < 0.001). La insulinemia se asocio al BMI (beta = 0.83, p < 0.001) y trigliceridos (beta = 0.01, p < 0.001). Conclusion: Este estudio demostro una alta prevalencia de dislipemia en una poblacion de ninos Koya que viven a grandes alturas, pese a que la prevalencia de sobrepeso y obesidad fue baja. Esto podria deberse a factores geneticos en una poblacion que podria tener gran predisposicion a desarrollar ECV. Palabras clave: ninos Koya, dislipemia, hemoglobina