[Analysis of pre-ablative and preoperative thyroglobulin in differentiated thyroid cancer]. / Análisis de tiroglobulina preablativa y cáncer diferenciado de tiroides preoperatorio.

BACKGROUND: The measurement of plasma thyroglobulin (Tg) is widely used in the monitoring of differentiated thyroid cancer (CDT). In recent years, its value as a prognostic marker prior to ablation with radioiodine has increased, demonstrating its high negative predictive value. Recent studies indicate that a wide variety of factors could potentially influence pre-ablative Tg values, including residual tumor burden and stimulation modality. AIM: To relate the value of pre-ablative Tg with the amount of preoperative disease burden, lymph node metastases, treatment, and presence of residual disease. MATERIAL AND METHODS: Retrospective observational study of 70 patients with CDT treated between 2012 and 2018. The amount of disease burden was defined as the sum of largest diameter of individual tumors in each patient, and as the individually largest tumor per patient and number of metastatic lymph nodes. RESULTS: A smaller tumor size and absence of remnant tissue was associated with lower Tg values, although the association was not always significant. Furthermore, no significant difference was found between Tg levels measured within or more than 14 days after the surgical procedure. Thus, an early measurement of pTg after surgery would allow an initial therapeutic decision making. CONCLUSIONS: A statistical association between pre-ablative Tg levels and the amount of preoperative tumor tissue burden was found in some subgroups of patients.

Lysosomal Membrane Stability in Hemocytes and Micronuclei in Gills of Perumytilus purpuratus Lamarck 1819 (Bivalvia: Mytilidae) Exposed to Copper.

The aim of this study was to determine the cytotoxic and genotoxic effects of copper on the bivalve Perumytilus purpuratus. The individuals were exposed to three copper concentrations: 1, 30 and 45 µg L-1 for 24, 48 and 96 h. Lysosomal membrane stability in hemocytes was determined through the neutral red retention time (NRRT) and micronucleus (MN) frequency tests in hemocytes and gills. The results show that the NRRT decreased significantly at 30 µg L-1 after 48 h of exposure. The frequency of MN was significantly greater in gills after 24 h in all concentrations tested. Copper is cytotoxic from 30 µg L-1 and genotoxic from 1 µg L-1. The use of these biomarkers of effects in P. purpuratus is proposed as an early warning tool for monitoring in environmental assessment of coastal ecosystems impacted by mining activities.

Massively parallel nanowell-based single-cell gene expression profiling.

BACKGROUND: Technological advances have enabled transcriptome characterization of cell types at the single-cell level providing new biological insights. New methods that enable simple yet high-throughput single-cell expression profiling are highly desirable. RESULTS: Here we report a novel nanowell-based single-cell RNA sequencing system, ICELL8, which enables processing of thousands of cells per sample. The system employs a 5,184-nanowell-containing microchip to capture ~1,300 single cells and process them. Each nanowell contains preprinted oligonucleotides encoding poly-d(T), a unique well barcode, and a unique molecular identifier. The ICELL8 system uses imaging software to identify nanowells containing viable single cells and only wells with single cells are processed into sequencing libraries. Here, we report the performance and utility of ICELL8 using samples of increasing complexity from cultured cells to mouse solid tissue samples. Our assessment of the system to discriminate between mixed human and mouse cells showed that ICELL8 has a low cell multiplet rate (< 3%) and low cross-cell contamination. We characterized single-cell transcriptomes of more than a thousand cultured human and mouse cells as well as 468 mouse pancreatic islets cells. We were able to identify distinct cell types in pancreatic islets, including alpha, beta, delta and gamma cells. CONCLUSIONS: Overall, ICELL8 provides efficient and cost-effective single-cell expression profiling of thousands of cells, allowing researchers to decipher single-cell transcriptomes within complex biological samples.

A household case evidences shorter shedding of SARS-CoV-2 in naturally infected cats compared to their human owners.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been detected in domestic and wild cats. However, little is known about natural viral infections of domestic cats, although their importance for modelling disease spread, informing strategies for managing positive human-animal relationships and disease prevention. Here, we describe the SARS-CoV-2 infection in a household of two human adults and sibling cats (one male and two females) using real-time RT-PCR, an ELISA test, viral sequencing, and virus isolation. On May 5th, 2020, the cat-owners tested positive for SARS-CoV-2. Two days later, the male cat showed mild respiratory symptoms and tested positive. Four days after the male cat, the two female cats became positive, asymptomatically. Also, one human and one cat showed antibodies against SARS-CoV-2. All cats excreted detectable SARS-CoV-2 RNA for a shorter duration than humans and viral sequences analysis confirmed human-to-cat transmission. We could not determine if cat-to-cat transmission also occurred.

Análisis de tiroglobulina preablativa y cáncer diferenciado de tiroides preoperatorio / Analysis of pre-ablative and preoperative thyroglobulin in differentiated thyroid cancer

BACKGROUND: The measurement of plasma thyroglobulin (Tg) is widely used in the monitoring of differentiated thyroid cancer (CDT). In recent years, its value as a prognostic marker prior to ablation with radioiodine has increased, demonstrating its high negative predictive value. Recent studies indicate that a wide variety of factors could potentially influence pre-ablative Tg values, including residual tumor burden and stimulation modality. Aim: To relate the value of pre-ablative Tg with the amount of preoperative disease burden, lymph node metastases, treatment, and presence of residual disease. MATERIAL AND METHODS: Retrospective observational study of 70 patients with CDT treated between 2012 and 2018. The amount of disease burden was defined as the sum of largest diameter of individual tumors in each patient, and as the individually largest tumor per patient and number of metastatic lymph nodes. RESULTS: A smaller tumor size and absence of remnant tissue was associated with lower Tg values, although the association was not always significant. Furthermore, no significant difference was found between Tg levels measured within or more than 14 days after the surgical procedure. Thus, an early measurement of pTg after surgery would allow an initial therapeutic decision making. Conclusions: A statistical association between pre-ablative Tg levels and the amount of preoperative tumor tissue burden was found in some subgroups of patients.

Automated high multiplex qPCR platform for simultaneous detection and quantification of multiple nucleic acid targets.

Quantitative PCR (qPCR) using real-time detection of amplification is limited to a small number of targets within a single reaction. The ICEPlex system, using our scalable target analysis routine (STAR) technology, was developed to provide an automated, high multiplexing PCR solution. ICEPlex combines PCR thermal cycling with dynamic, sequential amplicon separation by capillary electrophoresis and two-color quantitative detection in a single integrated system. In contrast to probe-based qPCR, ICEPlex directly measures amplicon accumulation through incorporation of labeled primers. Three orders of magnitude of optical detection range and at least 7 logs of detectable target concentration range are demonstrated. The system can separate more than 50 amplicons per color channel, ranging from 100 to 500 bases, providing broad multiplexing capabilities for a wide spectrum of nucleic acid amplification applications. ICEPlex can be used for analysis of viral DNA or RNA targets, detection of genetic variants, and for reverse-transcriptase PCR gene expression panels.

A comparison between two imaging techniques for the diagnosis of subacute thyroiditis (de Quervain thyroiditis): brief communication.

PURPOSE: Subacute thyroiditis (SAT) or de Quervain thyroiditis is a relatively frequent and self-limited condition with a triphasic clinical course. Its symptoms can mimic other thyroid, upper respiratory, and ear infections. Thyroid ultrasonography (TUS), radioactive iodine uptake (RAIU), and thyroid scintigraphy (TS) may be used for differential diagnosis. To assess and compare the diagnostic value of thyroid TUS and TS in patients on the first phase of a clinically diagnosed SAT. MATERIAL AND METHODS: Twenty-two patients (18 women and 4 men, age, 37.2 ± 9.83 years) with clinical diagnosis of SAT were prospectively studied. Thyroid stimulating hormone, T3, free T4, antithyroperoxidase antibodies, thyroglobulin, polymerase chain reaction, complete blood count and differential, TUS, TS, and RAIU at 2 and 24 hours were performed. RESULTS: All patients were on thyrotoxic phase with a thyroid stimulating hormone mean of 0.03 ± 0.030 mU/L (range: 0.005-0.13); antithyroperoxidase antibodies were positive in 3 patients (≥75 UI/mL); thyroglobulin was elevated in 16 patients (≥55 ng/mL). RAIU at 2 hours was 1.94% ± 0.85% (range: 1%-4%), and at 24 hours, 0.98% ± 1.24% (range: 0.10%-5%). TS showed low uptake in all patients. On TUS, only 8 patients were compatible with SAT. In 13 patients, TUS was consistent with goiter, diffuse type in 8, multinodular in 5, and normal in 1 patient. CONCLUSION: Low thyroid scan uptake with I-131 at 2 hours (<4%) and 24 hours (<5%), and poor thyroid visualization on TS seem to be more prevalent than focal distortion and heterogeneity in TUS in thyrotoxic phase of SAT.

F 18-FDG heart uptake in oncologic pet studies

Background: PET scanning with F-18 FDG is a useful technique to detect malignant lesions. The goal of this work to analyze the frequency of increased heart uptake in routine PET oncologic studies and to correlate F-18 FDG Standardized Uptake Values (SUV) to blood glucose level (BGL)

Captación miocárdica de pirofosfato en amiloidosis cardíaca: caso clínico / Myocardial pyrophosphate uptake in cardiac amyloidosis: clinical case

We report a previously healthy 73 years old woman, who was hospitalised with increasing dyspnea and signs of congestive heart failure. Echocardiography showed a normal left ventricular cavity with increased echogenicity of its walls and severe pulmonary hypertension. A lung ventilation/perfusion scintigraphy concluded that there was a low probability for pulmonary embolism. Coronary angiography was normal. A restrictive cardiomyopathy due to amyloid deposits was suspected. Myocardial pyrophosphate scintigraphy showed intense pyrophosphate uptake in the left ventricle wall. An abdominal fat tissue biopsy was positive for amyloid deposits

Aplicaciones clínicas del PET / Positron emission tomography imaging, PET, in clinical practice

Functional imaging using PET (positron emission tomography) has a great impact on current medical practice. It allows to explore, in a very precise way, different processes such as tissue flow and metabolism. Fluor-deoxyglucose labeled with F18 fluorine represents glucose metabolism. Among its main applications are detection, staging, follow up and recurrence assessment of malignant tumors; myocardial viability detection in patients with myocardial infarction or ischemic cardiomyopathy, and evaluation of hyperactive epileptogenic foci in brain. The basis and clinical applications of PET tomography are reviewed especially oriented to its cost benefit relationship, change in patient management and diagnostic value of the most accepted oncological indications. Important economic resources may be saved with PET in this field, considering appropriate staging and recurrence detection, avoiding expensive therapeutic approaches in advanced disease

Tomografía SPECT con F18 fluorodeoxiglucosa en infarto reciente del miocardio: caso clínico / Fluorodexyglucose SPECT in recent myocardial infarction: clinical case

We report a 50-year-old woman with a recent myocardial infarction in whom a myocardial perfusion single photon emission computed tomography (SPECT) with Thallium201 was done simultaneously with a F18-fluordeoxyglucose (FDG) SPECT to study glucose metabolism. Myocardial infarction was located in the anteroseptal and apical regions and an echocardiography, done at the second day of evolution, showed a septo-apical hypokinesia. On the tenth day, a coronary angiography showed a critical lesion of the anterior descending coronary artery and an angioplasty with stent placement was performed on the next day. On the twelfth day, a resting, redistribution 201Tl SPECT to study viability and a FDG-SPECT with a dual head high-energy collimator camera were done. Images, acquired 45 min after injection, were analyzed visually. In anterior and medial apical sectors, discordance between flux and metabolism, considered a classical mismatch, was observed. Echocardiographic hypokinesia disappeared three month after revascularization

Rendimiento del SPECT talio 201: reposo redistribución para predecir viabilidad post infarto reciente del miocardio / Performance of thallium 201 rest redistribution SPECT to predict viability in recent myocardial infarction

Background: The detection of viability after acute myocardial infarction is primordial to select the most appropriate therapy, to decrease cardiac events and abnormal remodeling. Thallium201 SPECT is one of the radionuclide techniques used to detect viability. Aim: To evaluate the use of Thallium201 rest-redistribution SPECT to detect myocardial viability in reperfused patients after a recent myocardial infarction. Patients and methods: Forty one patients with up to of 24 days of evolution of a myocardial infarction were studied. All had angiographically demonstrated coronary artery disease and were subjected to a successful thrombolysis, angioplasty or bypass grafting. SPECT Thallium201 images were acquired at rest and after 4 h of redistribution. These results were compared with variations in wall motion score, studied at baseline and after 3 or 4 months with echocardiography. Results: The sensitivity of rest-redistribution Thallium201 SPECT, to predict recovery of wall motion was 91 percent when patient analysis was performed and 79 percent when segmental analysis was done in the culprit region. The figures for specificity were 56 and 73 percent respectively. Conclusions: Rest-distribution Thallium201 SPECT has an excellent sensitivity to predict myocardial viability in recent myocardial infarction. The data obtained in this study is similar to that reported for chronic coronary artery disease

Aporte de cardiología nuclear al diagnóstico de arritmias / Contribution of nuclear cardiology in the diagnosis of arrhythmias

Se presenta una revisión actualizada del rol de los procedimientos de cardiología nuclear al diagnóstico de arritmias. El enfoque es eminentemente práctico y conceptual. Los procedimientos en general tienen aplicación en investigación; sin embargo, hay aplicaciones específicas de utilidad clínica. En particular, se ha empleado el Análisis de Fase (Fourier), obtenido de ventrículografía radioisotópica en la localización de haces accesorios en pacientes con Síndrome de Wolff-Parkinson-White, con buen rendimiento cuando el haz está lateralizado. Si la vía accesoria se encuentra en el séptum, entonces la diferenciación con la vía normal es más difícil. El Análisis de Fase también se ha empleado en la detección de origen de taquicardias ventriculares, focos de extrasistolia ventricular, bloqueos de rama y la displasia arritmogénica del ventriculo derecho. En pacientes con arritmias puede utilizar las técnicas de perfusión con Talio 201 o Tc99m MIBI, para descartar la presencia de isquemia miocárdica

Estudio del tránsito esofágico y del reflujo gastroesofágico mediante el uso de radioisótopos / Study of the esophageal transit and the gastroesophageal reflux through the use of radioisotopes

El estudio del tránsito esofágico y del reflujo gastroesofágico mediante técnicas de medicina nuclear se iniciaron en 1982 en nuestro país, en el departamento al que pertenecen los autores. Se basa en el paso de un bolo radioactivo con Tc-99m, sulfuro coloide, que no se absorbe ni se adhiere a las mucosas, además de producir bajos niveles de radiación, analizándose mediante una gammacámara conectada a un computador, cualitativa y cuantitativamente la radioactividad a nivel esofágico. De alta sensibilidad, en las diversas patologías a estudiar, el método ofrece varias ventajas con respecto a otras técnicas convencionales: cuantitativa, no invasiva, bien tolerada por el paciente y de fácil y breve ejecución, permite su realización repetida para mejor control de la enfermedad, además de ser aplicable a la población pediátrica

Definiendo la necesidad de especialistas y gammacámaras en medicina nuclear / Defining the need of specialists and gammacameras in nuclear medicine

The aim of this work was to establish the relationship between the number of gammacameras, nuclear medicine specialists and the number of inhabitants in different countries, including Chile. Information was obtained from the International Atomic Energy Agency, Britannic and Canadian Nuclear Medicine Societies, Pan-American Health Organization and American College of Nuclear Physicians. Industrialized countries have approximately 1 specialist and 0.5-3.3 gammacameras per 100,000 inhabitants. The respective figures in Chile are 0.25 and 0.25. Due to the unequal distribution of resources in Chile, the specialists and gammacameras rate in the Metropolitan area is 0.6, some regions or communities do not have these resources and in other communities the rate can raise up to nine. Compared to industrialized countries, Chile lacks nuclear medicine specialists and gammacameras and these resources are unevently distributed

Hipertensión arterial renovascular: rol del cintigrama renal en su detección y en la predicción de la respuesta clínica a la revascularización / Renovascular arterial hypertension: role of renal scintigraphy on it detection and on the prediction of clinical response to revascularization

The most frequently used non invasive tests in the diagnosis of renovascular hypertension are the measurement of peripheral blood renin before and after captopril administration, intravenous pyelogram, renal Doppler examination and radionuclide renography without and with angiotensin converting enzyme inhibitor administration. Measurement of renal vein renin levels and renal angiography are invasive tests commonly used. The latter allows an anatomical disgnosis of renal veins stenosis but does not give information about pressure to revascularization. Radionuclide renography has become the most useful non invasive diagnostic test, with a sensitivity and specificity of 83-94 and 85-97 percent respectively. It also predicts clinical response to revascularization and is useful for follow up after surgery or angioplasty. It also had good results in patients with renal failure, bilateral stenosis or stenosis in a solitary kidney and in transplantated patients

Estudio del vaciamiento gástrico líquido postcirugía gástrica con método cintigráfico / Study of the liquid gastric emptying in gastric postsurgery with scintigraphic method

En este estudio prospectivo, se analiza el comportamiento del estómago operado al vaciamiento líquido con método radioisotópico. Se estudiaron quince sujetos portadores de ulcera duodenal y cinco normales. Se estudió el comportamiento ante la vagotomía supraselectiva y vagotomía selectiva más antrectomía. Se demostró una importante alteración del vaciamiento a los líquidos, mayor en el estómago resecado, con recupración parcial en los controles tardíos

Evaluación de masa ósea en fractura de cadera cuantificando columna lumbar y cadera contralateral con densitometría ósea / Evaluation of bone mass in hip fracture, quantifying lumbar bone marrow and contralateral hip with bone densitometry

Hip fracture is frecuent in postmenopausal women with osteoporosis. The aim of this work was to assess bone mass in women with hip fracture and compare it with that of normal women. Bone densities of lumbar spine (considering areas with and without spondylosis), female neck, greater trochanter and unfractures hip Ward's triangle were measured with a double beam isotopic densitometer. Thirty one women aged 58-95 years old were studied and compared with normal women studied at the same laboratory. Bone densities in fractures and normal women were 0.82ñ0.16 and 0.85ñ0.05 g/cm2 in lumbar spine respectively (NS), 0.74ñ0.15 and 0.85ñ0.05 g/cm2 in lumbar spine without spondylosis respectively (p<0.001), 0.60ñ0.11 and 0.65ñ0.08 g/cm2 in femoral neck respectively (NS), 0.49ñ0.09 and 0.52ñ0.09 g/cm2 in greater trochanter respectively (p<0.001) and 0.48ñ0.12 and 0.52ñ0.09 g/cm2 in Ward's triangle respectively (NS). It is concluded that the larger differences in bone density between women with and without hip fracture are observed in the greater trochanter