Effects of pre-analytical sample care and analysis methodology on measures of metabolic acidosis in hemodialysis patients.

INTRODUCTION: We evaluated the effects of pre-analytical care on total carbon dioxide (tCO2 ) in hemodialysis patients, as calculated by blood gas analysis (ctCO2 ) or measured by an enzymatic assay (mtCO2 ). METHODS: Blood samples were collected via vascular access before dialysis sessions. For blood gas analysis, eight aliquots were collected, refrigerated or non-refrigerated, and analyzed at 0, 4, 8, and 24 h after collection. A blood sample was then collected for the enzymatic method and distributed into 14 aliquots. Half of the aliquots were refrigerated. The samples analyzed at time point 0 were centrifuged immediately. The remaining aliquots of both the refrigerated and non-refrigerated clusters were centrifuged before storage. Samples were analyzed at 4, 8, and 24 h post-collection. FINDINGS: By blood gas analysis, no significant change was found in bicarbonate values over time, either in the non-refrigerated or refrigerated samples. ctCO2 values during the experiment showed a minor but statistically significant increase of questionable clinical relevance in both non-refrigerated and refrigerated aliquots. In the enzymatic assay, the reduction in mtCO2 levels during the experiment was negligible. The median absolute reductions at the end of the experiment were 1.77, 1.21, 1.04, and 1.12 mmol/L for the non-centrifuged/non-refrigerated, centrifuged/non-refrigerated, non-centrifuged/refrigerated, and centrifuged/refrigerated aliquots, respectively. DISCUSSION: Our results suggest that measured or calculated tCO2 levels of capped and cooled samples are adequate for analyzing the acid-base status of hemodialysis patients, even when such determination is not performed immediately after collection.

Liver fibrosis improvement in chronic hepatitis C after direct acting-antivirals is accompanied by reduced profibrogenic biomarkers-a role for MMP-9/TIMP-1.

BACKGROUND AND AIMS: Disturbances in matrix metalloproteinases (MMPs) and corresponding tissue inhibitors (TIMPs) contribute to hepatitis C virus (HCV)-induced fibrosis. This study aimed to determine MMP-9/TIMP-1 levels in addition to MMP-2 and -9 activities; correlating with the improvement of liver fibrosis in patients under direct-acting antiviral (DAA) therapy. METHODS: Clinical and laboratory follow-up were performed before treatment and after 12 weeks post-treatment, referred as sustained viral response (SVR). We evaluated liver function including non-invasive fibrosis measurements; MMP activity by zymography; and MMP-9/TIMP-1 complex, inflammatory and pro-fibrogenic mediators by immunoenzymatic assays. RESULTS: Cohort included 33 patients (59.5 ±â€¯9.3 years, 60.6% females) whose reached SVR and 11 control-paired subjects (42.5 ±â€¯15 years, 54.5% females). Before treatment, HCV patients presented higher MMP-9/TIMP-1 levels (P < 0.05) when compared to controls, and the highest values were observed in patients with fibrosis (P < 0.05). In addition, MMP-9/TIMP-1 levels were significantly reduced after DAA therapy (P < 0.0001) and were associated with profibrogenic biomarkers. No differences were observed for MMP-2 and -9 activities; however, these biomarkers were significantly associated with inflammatory mediators. CONCLUSION: Our data suggest that MMP-9/TIMP-1 complex can be a promising biomarker of active fibrogenesis, being able to identify the interruption of fibrosis progression after HCV eradication.

COVID-19: clinical and laboratory manifestations in novel coronavirus infection / COVID-19: manifestações clínicas e laboratoriais na infecção pelo novo coronavírus

ABSTRACT COVID-19 is a highly contagious disease caused by the coronavirus of severe acute respiratory syndrome 2 (SARS-CoV-2). In 2020, due to the outbreak, it was considered by the World Health Organization (WHO) as a pandemic. The infection caused by the novel coronavirus has high mortality in a small portion of the infected population, especially in elderly, immunosuppressed, diabetic, cardiac, and hypertensive individuals. Many infected are asymptomatic (and may be carriers) or present mild or moderate flu-like symptoms. The most severe clinical picture of COVID-19 is characterized by an inflammatory cytokine storm, with hematological changes and coagulation dysfunction, which can lead to tissue damage and death. Nonspecific laboratory biomarkers may be either increased or decreased as the course of the disease progresses and are often useful in predicting complications of the disease, such as the use of D-dimer and platelet/lymphocyte ratio. Specific laboratory diagnosis is based on the detection of viral ribonucleic acid (RNA) by real-time polymerase chain reaction (RT-PCR) of nasal and oropharyngeal swab samples; it is more effective when performed in the first days after symptom onset. Serological tests are useful in detecting the immune response, since both class M (IgM) and class G (IgG) immunoglobulin antibodies can be detected seven days after the onset of clinical symptoms, and may extend for more than 25 days, although not exempting the individual from remaining infectious, depending on their viral load and clinical presentation. The rational use of specific laboratory markers must respect the disease chronology, and the correct interpretation may provide subsidies for a better management of affected patients, as well as identifying asymptomatic carriers or those with mild symptoms.

RESUMEN La COVID-19 es una enfermedad altamente contagiosa causada por el coronavirus del síndrome respiratorio agudo grave (SARS-CoV-2). En 2002, a causa del brote, fue reconocida como una pandemia por la Organización Mundial de la Salud (OMS). La infección por el nuevo coronavirus provoca alta mortalidad en una pequeña parcela de la población infectada, especialmente en ancianos, pacientes inmunodeprimidos, diabéticos, cardiópatas e hipertensos. Muchos infectados son asintomáticos (y pueden ser portadores) o presentan síntomas leves a moderados, como en un estado gripal. El cuadro clínico de la COVID-19 en la forma más grave es caracterizado por una tormenta inflamatoria de citoquinas, con cambios hematológicos y de la coagulación que pueden llevar a daño tisular y muerte. Pruebas de laboratorio inespecíficas pueden presentar tasas más altas o bajas según el curso de la enfermedad, y muchas veces son útiles en la predicción de complicaciones, como el uso del dímero D y la ratio plaquetas/linfocitos. El diagnóstico de laboratorio específico se basa en la detección del ácido ribonucleico (ARN) viral por reacción en cadena de la polimerasa (PCR) en tiempo real de muestras de hisopado nasal y orofaríngeo; es más efectiva en los primeros días tras el inicio de los síntomas. Pruebas serológicas son útiles para detectar la respuesta inmune, pues tanto los anticuerpos de la inmunoglobulina M (IgM) como de la G (IgG) pueden se detectar siete días después del inicio de los síntomas clínicos, y pueden permanecer por más de 25 días, aunque no eximen al individuo de seguir infeccioso, dependiendo de su carga viral y presentación clínica. El uso racional de los marcadores de laboratorio específicos debe respetar la cronología de la enfermedad, y la interpretación correcta puede proporcionar recursos para un mejor manejo de los pacientes afectados, así como identificar portadores asintomáticos o con pocos síntomas.

RESUMO COVID-19 é uma doença altamente contagiosa provocada pelo coronavírus da síndrome respiratória aguda grave 2 (SARS-CoV-2). Em 2020, devido ao surto, foi caracterizada pela Organização Mundial da Saúde (OMS) como pandemia. A infecção causada pelo novo coronavírus tem alta mortalidade em uma pequena parcela da população infectada, especialmente em indivíduos idosos, imunodeprimidos, diabéticos, cardiopatas e hipertensos. Muitos infectados são assintomáticos (e podem ser portadores) ou apresentam sintomas leves a moderados, semelhantes ao estado gripal. O quadro clínico da COVID-19 na forma mais severa é caracterizado por uma tempestade inflamatória de citocinas, com alterações hematológicas e da coagulação que podem levar ao dano tecidual e morte. Exames laboratoriais inespecíficos podem apresentar-se mais elevados ou diminuídos conforme o curso da doença, e muitas vezes são úteis na predição de complicações, como o uso do D-dímero e a razão plaqueta/linfócitos. O diagnóstico laboratorial específico se baseia na detecção do ácido ribonucleico (RNA) viral por reação em cadeia da polimerase em tempo real (RT-PCR) de amostras de suabe nasal e orofaríngeo; é mais efetivo nos primeiros dias após o início dos sintomas. Testes sorológicos são úteis na detecção da resposta imune, pois tanto os anticorpos da imunoglobulina da classe M (IgM) quanto da classe G (IgG) podem ser detectados após sete dias do início dos sintomas clínicos, podendo se estender por mais de 25 dias, embora não isente o indivíduo de continuar infectante, dependendo de sua carga viral e apresentação clínica. O uso racional dos marcadores laboratoriais específicos deve respeitar a cronologia da doença, e a interpretação correta pode fornecer subsídios para um melhor manejo dos pacientes acometidos, bem como identificar portadores assintomáticos ou com pouco sintomas.

Clinical, laboratorial diagnosis and prophylaxis of measles in Brazil / Diagnóstico clínico, laboratorial e profilático do sarampo no Brasil

ABSTRACT Measles is an acute febrile exanthematic disease of viral etiology, highly contagious, being the cause of morbidity and mortality of children in developing countries, whereas it has become rarer in developed countries due to vaccination. Its differential diagnosis should be made with other childhood viral respiratory diseases such as influenza, rhinovirus and adenovirus, and exanthematic febrile diseases such as rubella, roseola and varicella. In tropical regions, it should be performed with dengue, zika and chikungunya. Its clinical picture presents the following phases: incubation, usually asymptomatic; a prodrome, in which fever, malaise, coryza can occur, besides Koplik's signs; exanthematic, with presence of maculopapular exanthema after the fever condition that progresses to a craniocaudal evolution, with clinical improvement in uncomplicated cases. Common complications are pneumonia, otitis media, keratitis; the rarest are acute disseminated encephalomyelitis and subacute sclerosing panencephalitis. Nonspecific laboratory alterations are seen in the blood count. The specific laboratory diagnosis is based on the detection of viral ribonucleic acid (RNA) [polymerase chain reaction (PCR) of nasal swab samples, oral mucosa or urine]. Immunoglobulin class M (IgM) can be detected during the exanthematous period by enzyme-linked immunosorbent assay (ELISA), and immunoglobulin class G (IgG) throughout the convalescence period, and the detection of specific IgG by the plaque reduction neutralization test may also be performed. The prophylaxis of the disease is based on vaccination in children from 15 months in order to reach about 85% to 95% of the population, what confers herd immunity. Thus, vaccination is the most effective measure in combating measles, since the treatment consists only of clinical and symptomatic support.

RESUMEN El sarampión es una enfermedad exantemática febril aguda de etiología viral altamente contagiosa. Causa morbilidad y mortalidad de niños en países en desarrollo, mientras que se hizo más raro en países desarrollados gracias a la vacunación. El diagnóstico diferencial se hace con otras enfermedades infantiles, como influenza, rinovirus, adenovirus, rubéola, roséola y varicela. En regiones tropicales, incluye dengue, zika y chikungunya. Su cuadro clínico presenta las siguientes fases: incubación - en general asintomática; pródromo - en la cual pueden ocurrir fiebre, malestar y coriza, además de manchas de Koplik; y la exantemática - con presencia de exantema máculo-papular después del cuadro febril, que se disemina desde la cara a tronco y extremidades, con mejora clínica en casos no complicados. Complicaciones comunes son neumonía, otitis media y queratoconjuntivitis; las más raras, encefalomielitis aguda diseminada y panencefalitis esclerosante subaguda. Alteraciones inespecíficas de laboratorio son vistas en el hemograma. El diagnóstico específico de laboratorio se basa en el aislamiento del ácido ribonucleico (ARN) viral (PCR de muestras nasales, mucosa oral u orina). La inmunoglobulina M (IgM) pude ser detectada durante el período exantemático por ensayo por inmunoadsorción ligado a enzimas (ELISA); la inmunoglobulina G (IgG), a lo largo del período de convalecencia, y la detección de IgG específica por la prueba de neutralización por reducción de placa. La profilaxis de la enfermedad se basa en vacunación en niños desde los 15 meses de edad, buscando alcanzar 85%-95% de la población, lo que confiere inmunidad de grupo. La vacunación es la medida más eficaz en el combate al sarampión, puesto que el tratamiento consiste sólo en soporte clínico.

RESUMO O sarampo é uma doença exantemática febril aguda de etiologia viral altamente contagiosa. É causa de morbidade e mortalidade de crianças em países em desenvolvimento, ao passo que se tornou mais rara em países desenvolvidos devido à vacinação. O diagnóstico diferencial deve ser realizado em relação a outras doenças da infância, como influenza, rinovírus, adenoviroses, rubéola, roséola e varicela. Já em regiões tropicais, inclui dengue, vírus da zika e chikungunya. Seu quadro clínico apresenta as seguintes fases: a de incubação - em geral assintomática; a prodrômica - na qual podem ocorrer febre, mal-estar e coriza, além de sinais de Koplik; e a exantemática - com presença de exantema maculopapular após o quadro febril, que progride de forma craniocaudal, com melhora clínica em casos não complicados. Complicações comuns são pneumonia, otite média e ceratoconjuntivite; as mais raras, encefalomielite disseminada aguda e panencefalite esclerosante subaguda. Alterações laboratoriais inespecíficas são vistas no hemograma. O diagnóstico laboratorial específico baseia-se na detecção do ácido ribonucleico (RNA) viral [reação em cadeia da polimerase (PCR) de amostras de swab nasal, mucosa oral ou urina]. Imunoglobulina da classe M (IgM) pode ser detectada durante o período exantemático por ensaio de imunoadsorção enzimática (ELISA) e imunoglobulina da classe G (IgG), ao longo do período de convalescença, podendo também ser realizada a detecção de IgG específica pelo teste de neutralização por redução de placas. A profilaxia da doença é baseada na vacinação em crianças a partir dos 15 meses de idade, visando atingir cerca de 85% a 95% da população, o que confere imunidade de rebanho. A vacinação é a medida mais eficaz no combate ao sarampo, visto que o tratamento consiste apenas em suporte clínico.

Yellow fever: laboratorial diagnosis and clinical manifestations / Febre amarela: diagnóstico laboratorial e manifestações clínicas

ABSTRACT Yellow fever is an infectious disease of acute evolution, initially non-contagious, transmitted by a ribonucleic acid (RNA) virus that belongs to the Flaviviridae family. In the period from December 2016 until March 17, 2017, 1, 561 suspected cases of wild yellow fever were reported to the Ministry of Health in Brazil. Among these cases, 850 (54.8%) remain under investigation, 448 (28.7%) were confirmed and 263 (16.9%) were discarded. Out of the total cases reported, 264 died, 144 (54.5%) were confirmed for the disease, 110 (41.7%) were investigated and 10 (3.8%) were discarded. The case fatality rate among confirmed cases was 32.2%. The specific diagnosis for determining the etiology of infection can be made by demonstrating the humoral response of the antibodies, virus isolation, or histopathological study of the liver. Only through early laboratory diagnosis and epidemiological data supply can government and cooperative organizations establish public policies to combat future disease epidemics, as well as social awareness campaigns.

RESUMO A febre amarela é uma doença infecciosa de evolução aguda, a princípio não contagiosa, transmitida por um vírus do ácido ribonucleico (RNA) que pertence à família Flaviviridae. No período de dezembro de 2016 a 17 de março de 2017, foram notificados ao Ministério da Saúde, 1.561 casos suspeitos de febre amarela silvestre no Brasil. Destes, 850 (54, 8%) permanecem em investigação; 448 (28, 7%) foram confirmados e 263 (16, 9%), descartados. Do total dos casos notificados, 264 evoluíram para óbito, sendo 144 (54, 5%) confirmados para a doença; 110 (41, 7%) em investigação e 10 (3, 8%), descartados. A taxa de letalidade entre os casos confirmados foi de 32, 2%. O diagnóstico específico para determinação da etiologia da infecção pode ser feito por meio da demonstração da resposta humoral dos anticorpos, do isolamento do vírus ou do estudo histopatológico do fígado. Apenas mediante o diagnóstico laboratorial precoce e o abastecimento de dados epidemiológicos é que governo e organizações cooperativas poderão estabelecer políticas públicas de combate a futuras epidemias da doença, bem como campanhas de conscientização social.

Clinical and laboratory diagnosis of Zika fever: an update / Diagnóstico clínico e laboratorial da febre pelo vírus da zika: uma atualização

ABSTRACT Zika fever can be defined as an acute febrile viral illness, mainly transmitted by the mosquito of the genus Aedes. It makes a differential diagnosis from diseases caused by other flaviviruses, such as chikungunya and dengue fever. Many people with Zika virus (ZIKV) infection will not have symptoms or will only have mild clinical symptoms. The clinical conditions are nonspecific and characterized by low-grade fever, pruritic erythematous maculopapular rash, non-purulent conjunctival hyperemia without pruritus, arthralgia, myalgia, and headache. It is a benign, self-limiting and short-duration condition. Complications such as Guillain-Barré syndrome (GBS), spontaneous abortion and fetal malformations, mainly microcephaly and retinal lesions, may occur. The laboratory investigation is more important in cases suspected of ZIKV infection that have evolved with neurological complications, in pregnant women, abortion or congenital malformations, and is a key part for diagnostic definition. Real-time polymerase chain reaction (RT-PCR) can detect the virus in blood samples about four to seven days after the onset of symptoms. In urine, it is possible to identify viral ribonucleic acid (RNA) up to 15 days after clinical onset, even if viremia has ceased, and it is an alternative for late diagnosis. Serological tests may also be performed, while there may be cross-reactivity with other flaviviruses. Immunoglobulin class M (IgM) can be screened between the 2nd and 12th week after clinical presentation. The immunoglobulin class G (IgG) can be identified after the 15th day, and is present even in the convalescence and cure phase. Non-specific laboratory abnormalities, in general, do not present significant alterations. Patients with GBS must have cerebrospinal fluid (CSF) collection for analysis.

RESUMO A febre zika pode ser definida como uma doença viral febril aguda, transmitida principalmente pelo mosquito do gênero Aedes, e faz diagnóstico diferencial com doenças causadas por outros flavivírus, como a dengue e a Chikungunya. Muitos indivíduos infectados pelo vírus da zika (ZIKV) não terão ou terão apenas leve sintomatologia clínica. O quadro clínico é inespecífico e caracterizado por febre baixa, exantema maculopapular pruriginoso, hiperemia conjuntival não purulenta e sem prurido, artralgia, mialgia e cefaleia. A doença é autolimitada, de curta duração e de evolução benigna, mas podem ocorrer complicações, como síndrome de Guillain-Barré (SGB), aborto espontâneo e malformações fetais, principalmente microcefalia e lesões retinianas. A investigação laboratorial apresenta maior importância nos casos suspeitos de infecção pelo ZIKV que evoluíram com complicações neurológicas, em gestantes, aborto ou malformações congênitas, sendo fundamental para definição diagnóstica. A reação em cadeia da polimerase em tempo real (RT-PCR) pode detectar o vírus em amostras de sangue por volta de quatro a sete dias após o início dos sintomas. Na urina, é possível identificar o ácido ribonucleico (RNA) viral até 15 dias após o início do quadro clínico, mesmo que a viremia tenha cessado, sendo uma alternativa para o diagnóstico tardio. Os testes sorológicos também podem ser realizados, embora haja possibilidade de reação cruzada com outros flavivírus. A imunoglobulina da classe M (IgM) pode ser pesquisada entre a 2ª e 12ª semana após o início do quadro clínico; a da classe G (IgG), após o 15º dia, estando presente mesmo na fase de convalescência e na cura. As alterações laboratoriais inespecíficas, em geral, não apresentam alterações significativas. Nos casos em que os pacientes apresentam SGB, é importante a coleta e a análise do liquor.

Diet and liver apoptosis in rats: a particular metabolic pathway / La dieta y la apoptosis hepática en ratas: una ruta metabólica particular

Introduction: Various studies have indicated an association between modification in dietary macronutrient composition and liver apoptosis. Objective: To explain how changes in metabolic pathways associated with a high-protein, high-fat, and low-carbohydrate diet causes liver apoptosis. Methods: Two groups of rats were compared. An experimental diet group (n = 8) using a high-protein (59.46%), high-fat (31.77%), and low-carbohydrate (8.77%) diet versus a control one (n = 9) with American Institute of Nutrition (AIN)-93-M diet. Animals were sacrifi ced after eight weeks, the adipose tissue weighed, the liver removed for fl ow cytometry analysis, and blood collected to measure glucose, insulin, glucagon, IL-6, TNF, triglycerides, malondialdehyde, and β-hydroxybutyrate. Statistical analysis was carried out using the unpaired and parametric Student’s t-test and Pearson’s correlation coefficients. Significance was set at p < 0.05. Results: Animals from the experimental group presented less adipose tissue than dose of the control group. Percentage of nonviable hepatocytes in the experimental group was 2.18 times larger than the control group (p = 0.001). No statistically significant differences were found in capillary glucose, insulin, glucagon, IL-6, or TNF-α between two groups. Plasmatic β-hydroxybutyrate and malondialdehyde of the experimental group expressed higher levels and triglycerides lower levels compared with the control group. The results show a positive and significant correlation between the percentage of nonviable hepatocytes and malondialdehyde levels (p = 0.0217) and a statistically significant negative correlation with triglycerides levels (p = 0.006). Conclusion: Results suggest that plasmatic malondialdehyde and triglyceride levels are probably good predictors of liver damage associated with an experimental low-carbohydrate diet in rats (AU)

Introducción: varios estudios han indicado una asociación entre la modificación de la composición de macronutrientes de la dieta y la apoptosis hepática. Objetivo: el objetivo fue explicar cómo los cambios en las rutas metabólicas provoca la apoptosis hepática. Métodos: se evaluó un grupo de 17 ratas. Un grupo (n = 8) con dieta experimental: proteínas (59,46%), grasas (31,77%) e hidratos de carbono (8,77%) y otro (n = 9) con dieta control (AIN-93-M). Los animales se sacrificaron después de ocho semanas, y se pesó el tejido adiposo, se retiró el hígado para su posterior análisis por citometría de flujo, y en la sangre recogida se midieron glucosa, insulina, glucagón, IL-6, TNF, triglicéridos, malondialdehído y β-hidroxibutirato. El análisis estadístico utilizó la prueba t no pareada y paramétrica de Student, y la correlación de Pearson; significación se fi jó en p < 0,05. Resultados: no se encontraron diferencias estadísticamente significativas en la glucosa capilar, insulina, glucagón, IL-6, TNF-α o en el grupo de la dieta experimental frente al control. El β-hidroxibutirato y malondialdehído se expresaron en los niveles más altos y los triglicéridos en los niveles más bajos en el grupo experimental. El porcentaje de células no viables en el grupo de dieta experimental era 2,18 veces mayor que la del grupo control. Había menos tejido adiposo de ratas alimentadas con la dieta experimental que la dieta control. Los resultados muestran una correlación positiva y significativa entre el porcentaje de células viables y malondialdehído y una correlación negativa estadísticamente significativa con los triglicéridos. Conclusión: malondialdehído y los niveles de triglicéridos en plasma son probablemente buenos predictores de daño hepático (AU)

Apoptosis induced by a low-carbohydrate and high-protein diet in rat livers.

AIM: To determine whether high-protein, high-fat, and low-carbohydrate diets can cause lesions in rat livers. METHODS: We randomly divided 20 female Wistar rats into a control diet group and an experimental diet group. Animals in the control group received an AIN-93M diet, and animals in the experimental group received an Atkins-based diet (59.46% protein, 31.77% fat, and 8.77% carbohydrate). After 8 wk, the rats were anesthetized and exsanguinated for transaminases analysis, and their livers were removed for flow cytometry, immunohistochemistry, and light microscopy studies. We expressed the data as mean ± standard deviation (SD) assuming unpaired and parametric data; we analyzed differences using the Student's t-test. Statistical significance was set at P < 0.05. RESULTS: We found that plasma alanine aminotransferase and aspartate aminotransferase levels were significantly higher in the experimental group than in the control group. According to flow cytometry, the percentages of nonviable cells were 11.67% ± 1.12% for early apoptosis, 12.07% ± 1.11% for late apoptosis, and 7.11% ± 0.44% for non-apoptotic death in the experimental diet group and 3.73% ± 0.50% for early apoptosis, 5.67% ± 0.72% for late apoptosis, and 3.82% ± 0.28% for non-apoptotic death in the control diet group. The mean percentage of early apoptosis was higher in the experimental diet group than in the control diet group. Immunohistochemistry for autophagy was negative in both groups. Sinusoidal dilation around the central vein and small hepatocytes was only observed in the experimental diet group, and fibrosis was not identified by hematoxylin-eosin or Trichrome Masson staining in either group. CONCLUSION: Eight weeks of an experimental diet resulted in cellular and histopathological lesions in rat livers. Apoptosis was our principal finding; elevated plasma transaminases demonstrate hepatic lesions.