Analytical Performance of COVID-19 Detection Methods (RT-PCR): Scientific and Societal Concerns.

Background. Health and social management of the SARS-CoV-2 epidemic, responsible for the COVID-19 disease, requires both screening tools and diagnostic procedures. Reliable screening tests aim at identifying (truely) infectious individuals that can spread the viral infection and therefore are essential for tracing and harnessing the epidemic diffusion. Instead, diagnostic tests should supplement clinical and radiological findings, thus helping in establishing the diagnosis. Several analytical assays, mostly using RT-PCR-based technologies, have become commercially available for healthcare workers and clinical laboratories. However, such tests showed some critical limitations, given that a relevant number of both false-positive and false-negative cases have been so far reported. Moreover, those analytical techniques demonstrated to be significantly influenced by pre-analytical biases, while the sensitivity showed a dramatic time dependency. Aim. Herein, we critically investigate limits and perspectives of currently available RT-PCR techniques, especially when referring to the required performances in providing reliable epidemiological and clinical information. Key Concepts. Current data cast doubt on the use of RT-PCR swabs as a screening procedure for tracing the evolution of the current SARS-COV-2 pandemic. Indeed, the huge number of both false-positive and false-negative results deprives the trustworthiness of decision making based on those data. Therefore, we should refine current available analytical tests to quickly identify individuals able to really transmit the virus, with the aim to control and prevent large outbreaks.

Pulse wave velocity as marker of preclinical arterial disease: reference levels in a uruguayan population considering wave detection algorithms, path lengths, aging, and blood pressure.

Carotid-femoral pulse wave velocity (PWV) has emerged as the gold standard for non-invasive evaluation of aortic stiffness; absence of standardized methodologies of study and lack of normal and reference values have limited a wider clinical implementation. This work was carried out in a Uruguayan (South American) population in order to characterize normal, reference, and threshold levels of PWV considering normal age-related changes in PWV and the prevailing blood pressure level during the study. A conservative approach was used, and we excluded symptomatic subjects; subjects with history of cardiovascular (CV) disease, diabetes mellitus or renal failure; subjects with traditional CV risk factors (other than age and gender); asymptomatic subjects with atherosclerotic plaques in carotid arteries; patients taking anti-hypertensives or lipid-lowering medications. The included subjects (n = 429) were categorized according to the age decade and the blood pressure levels (at study time). All subjects represented the "reference population"; the group of subjects with optimal/normal blood pressures levels at study time represented the "normal population." Results. Normal and reference PWV levels were obtained. Differences in PWV levels and aging-associated changes were obtained. The obtained data could be used to define vascular aging and abnormal or disease-related arterial changes.

Diarrea crónica como manifestación inicial de un ganglioneuroblastoma / Chronic diarrhea as the initial manifestation of a ganglioneuroblastoma

Resumen: El neuroblastoma es un tumor maligno del sistema nervioso simpático periférico con presentación y curso clínico heterogéneo. Es el tercer tumor pediátrico más frecuente y el 90% de los casos se diagnostica antes de los 5 años. Los síntomas más comunes se deben a la compresión por la masa tumoral o al dolor óseo causado por la metástasis. La diarrea como síntoma principal es rara por lo que es difícil de diagnosticar en la etapa temprana de la enfermedad. Se presenta el caso clínico de una paciente de 2 años en la que luego de 8 meses de estudio por diarrea crónica se diagnóstica ganglioneuroblastoma secretor de VIP. Se debe plantear como diagnóstico diferencial en los pacientes menores de 3 años con diarrea crónica intratable luego de haber descartado otras etiologías.

Summary: Neuroblastoma is a malignant tumor of the peripheral sympathetic nervous system with heterogeneous clinical presentation and course. It is the third most frequent pediatric tumor and in 90% of cases it is diagnosed before 5 years of age. The most typical symptoms result from the tumor compression or bone pain caused by methastasis. Diarrhea as the main symptom is unusual, and thus it is hard to diagnose in early stages of the disease. We report the case of a 2-year-old patient who, after 8 months of study for chronic diarrhea was diagnosed with VIP-secreting ganglioneuroblastoma. It is necessary for this condition to be considered as a differential diagnosis in patients younger than 3 years old with chronic diarrhea with no evolution, after other etiologies are ruled out.

Uruguay eHealth initiative: preliminary studies regarding an integrated approach to evaluate vascular age and preclinical atherosclerosis (CUiiDARTE project).

In this work we present an initiative to develop a national (Uruguayan) program to evaluate vascular age and to detect pre-clinical atherosclerosis using: gold-standard technologies; complimentary and integrative approaches to asses arterial functional and structural indexes; data bases systems to process, analyze and determine normal and reference values and to identify the most sensitive markers of vascular changes for different ages. We evaluated, in a Uruguayan population complementary structural and functional vascular parameters that associate aging-related changes and are considered markers of sub-clinical atherosclerosis. Traditional CV risk factors were assessed. The subjects (n=281) were submitted to non-invasive vascular studies to evaluate: 1) Common carotid artery (CCA) intima-media thickness and diameter waveforms, 2) CCA stiffness, 3) aortic stiffness (pulse wave velocity) and 4) peripheral and central pressure pulse wave derived parameters. Age groups: 21-30, 31-40, 41-50, 51-60, and 61-70 years-old. Age-related profiles were obtained for the different vascular parameters, and their utility to assess vascular changes in young, middle-aged and old subjects was evaluated. The work has the strength of being the first that uses, in Latin-America an integrative approach to characterize vascular aging-related changes.

Integrated Evaluation of Age-Related Changes in Structural and Functional Vascular Parameters Used to Assess Arterial Aging, Subclinical Atherosclerosis, and Cardiovascular Risk in Uruguayan Adults: CUiiDARTE Project.

This work was carried out in a Uruguayan (South American) population to characterize aging-associated physiological arterial changes. Parameters markers of subclinical atherosclerosis and that associate age-related changes were evaluated in healthy people. A conservative approach was used and people with nonphysiological and pathological conditions were excluded. Then, we excluded subjects with (a) cardiovascular (CV) symptoms, (b) CV disease, (c) diabetes mellitus or renal failure, and (d) traditional CV risk factors (other than age and gender). Subjects (n = 388) were submitted to non-invasive vascular studies (gold-standard techniques), to evaluate (1) common (CCA), internal, and external carotid plaque prevalence, (2) CCA intima-media thickness and diameter, (3) CCA stiffness (percentual pulsatility, compliance, distensibility, and stiffness index), (4) aortic stiffness (carotid-femoral pulse wave velocity), and (5) peripheral and central pressure wave-derived parameters. Age groups: ≤20, 21-30, 31-40, 41-50, 51-60, 61-70, and 71-80 years old. Age-related structural and functional vascular parameters profiles were obtained and analyzed considering data from other populations. The work has the strength of being the first, in Latin America, that uses an integrative approach to characterize vascular aging-related changes. Data could be used to define vascular aging and abnormal or disease-related changes.

Asociación de déficit de vitamina D y anemia en pacientes en hemodiálisis crónica / Vitamin D deficiency associated with anemia in patients on chronic hemodialisis

Introducción: el déficit de vitamina D (25VD) es frecuente. Objetivo: evaluar la prevalencia del déficit severo de 25VD (DS-25VD) en hemodiálisis crónica (HDC) y su asociación con alteraciones metabólicas. Material y método: estudio de corte transversal de pacientes en HDC. Se consignó edad, sexo, hospitalizaciones y dosis de eritropoyetina (epo). Se midió calcio, fósforo, hemoglobina, hormona paratiroidea intacta (PTHi), ferritina, proteína C reactiva (PCR), 25VD y resistencia a epo (dosis/gramo Hb). Se consideró DS-25VD menor a 10 ng/ml, anemia como hemoglobina menor a 10 g/dL o uso de epo. Se catalogó elevadas: ferritina mayor a 500 ng/ml y PCR mayor a 5 mg/L. Se estimó riesgo de DS-25VD y anemia por regresión logística. Se comparó por chi cuadrado o test de t según DS-25VD, considerando significativa p < 0,05. Resultados: de 105 pacientes, 65 (61,9%) eran hombres, edad 69,8 ± 13,2 años; 33 (31,4%) diabéticos. La media de 25VD fue de 13,0 ± 7,5 ng/ml, <30 ng/ml en 103 (97%) y 42 (40,8%) tuvieron DS-25VD. El DS-25VD se asoció a anemia (90,7% vs 75,8%) y anemia moderada-severa (76,7% vs 51,6%). Pacientes con DS-25VD tenían mayor resistencia a epo (8,6 vs 5,8), ferritina (592 vs 455 ng/ml) y PCR (15,8 vs 7,6 mg/L). El DS-25VD aumentó con PCR alta (OR: 4,59, IC95% 1,69-12,44), e incrementó el riesgo de anemia (OR: 3,09, IC: 1,06-9,01) ajustados a edad, sexo, diabetes y PTHi. Veintisiete pacientes con hospitalizaciones tuvieron significativamente menor Hb (10,2 ± 1,4 vs 11,2 ± 1,4) y 25VD (10,4 ± 3,8 vs 13,8 ± 8,2). Conclusiones: el DS-25VD se asocia a anemia y a mayor resistencia a epo en HDC. El mecanismo podría implicar mayor inflamación (PCR y ferritina altas)...

Rust urine after intense hand drumming is caused by extracorpuscular hemolysis.

BACKGROUND AND OBJECTIVES: During Carnival, groups of > or =60 drummers go drumming with their hands and marching for periods of 2 to 4 h. The objective of this study was to determine the frequency and type of urinary abnormalities after candombe drumming and to evaluate possible pathogenic mechanisms. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: For analysis of pathogenic mechanisms, a group of individuals were prospectively evaluated before and after candombe drumming. METHODS: Candombe drummers were recruited in January 2006, 1 wk before prolonged drumming. After clinical evaluation, urine and blood samples were obtained before and immediately after drumming. RESULTS: Forty-five healthy individuals (four women and 41 men), median age 31 yr (14 to 56), were evaluated. Predrumming urine and plasma samples were obtained for 30 individuals. Nineteen (42%) of 45 had a previous history of rust urine emission temporally related with candombe drumming. After drumming, 18 of 26 showed urine abnormalities; six of 26 showed rust urine, eight of 26 had microhematuria, and seven of 26 had proteinuria >1 g/L. The candombe drummers who showed rust urine after heavy drumming presented significantly higher levels of lactate dehydrogenase and total bilirubin when compared with those without urine abnormalities. Haptoglobin was significantly lower in the rust urine group. Fragmented red cells were observed in the blood smear of individuals with rust urine. Rust urine after drumming was associated with previous episodes of rust urine and glucosuria. CONCLUSIONS: Taken together, these data confirm that rust urine is caused by extracorpuscular hemolysis.

Evaluación de las vías aferentes del metabolismo del colesterol en el paciente psoriásico / Afferent and efferent ways of cholesterol metabolism in psoriatic patient

Las alteraciones del metabolismo lipoproteico en el paciente psoriásico, al igual que la patología vascular, han sido estudiadas por varios investigadores desde hace años, con diferentes resultados. La evaluación de este estudio muestra en la vía aferente, aumento significativo de colesterol LDL (20 por ciento), y de la lipoproteína (a) (16,4 +/-21,0 mg/dl) en psoriásicos vs (4,2 +/- 9,0 mg/dl) en controles. La vía eferente muestra descenso significativo de colesterol HDL (12 por ciento), apolipoproteína AI (15 por ciento) y lipopartícula AI:AII (24 por ciento), sin alteración de la lipopartícula AI. Los índices de aterogenecidad, reflejo de comportamiento de las vías aferente y eferente del colestrol, muestran aumento significativo del índice colestrol total/colestrol HDL (35 por ciento) y apoliproteína B/AI (32 por ciento), expresión de mayor riesgo de patología vascular ateroesclerótica. Los pacientes psoriásicos con mayor extensión lesional presentan mayores alteraciones lipídicas

Se debe usar siempre la nutrición perioperatoria en el cancer gástrico / We should use always in the nutrition perioperative in the gastric cancer?

La nutrición perioperatoria es discutida, ya que se ha planteado que puede aumentar las complicaciones postoperatorias. Prospectivamente se realizó un estudio de cánceres gástricos que serian operados sin complicaciones agudas. A los mismos se les dividió en 2 grupos, no al azar, uno de los cuales (PRE) recibió nutrición preoperatoria por lo menos 7 días y otro (POS), solo en el posoperatorio. Unicamente se incluyeron pacientes curados macroscopicamente de su enfermedad con la operación y sin complicaciones intra o postoperatorias inmediatas. La evaluación se realizó por parametros antropometricos y bioquímicos considerandose de mayor valor la perdida de peso y la albuminemia. La nutrición fue parenteral predominante. La morbilidad se consideró para dehiscencias (anastomotica o parietal) e infecciosas. Los resultados de la evaluación mostraron un significativo menor peso actual para el PRE (media: 50,1 kg+/-5,3; POS media: 61,6 kg +/-9,7p<0,001), presentando el 72,7 por ciento del total de los pacientes una perdida mayor del 10 por ciento. No hubo diferencias importantes entre las evaluaciones iniciales y finales de los grupos. El gasto Metabolico Basal fue de media: 1293 +/- 154; las calorías aportadas superaron ese valor en un 20 por ciento y no difirieron entre grupos. Los ingresos y egresos de Nitrogeno, tampoco fueron diferentes entre PRE y POS. La morbilidad fue de 10/33; 30, 3 por cientopara el "PRE" 3/11; 27,2 por ciento y 7/22; 31,8 por ciento para el "POS"x2=NS. La mortalidad fue de 1/33, 3,3 por ciento Una sola complicación fue imputable a la nutrición (neumotorax). La duración de la nutrición fue de media: 18+/-13 días (604 días total). El grupo "PRE" tuvo una media...