Comparative study between suprasternal and apical windows: a user-friendly cardiac output measurement for the anesthesiologist

Abstract Introduction Transthoracic echocardiography is a safe and readily available tool for noninvasive monitoring of Cardiac Output (CO). The use of the suprasternal window situated at the sternal notch can be an alternative approach for estimating blood flow. The present study aimed to compare two methods of CO calculation. We compared the descending aorta Velocity-Time Integral (VTI) measurement from the suprasternal window view with the standard technique to determine CO that uses VTI measurements from the LVOT (Left Ventricular Outflow Tract) view. We also aimed to find out whether after basic training a non-echocardiographer operator can obtain reproducible measurements of VTI using this approach. Methods In the first part of the study, 26 patients without known cardiovascular diseases were evaluated and VTI data were acquired from the suprasternal window by a non-echocardiographer and an echocardiographer. Next, 17 patients were evaluated by an echocardiographer only and VTI and CO measurements were obtained from suprasternal and apical windows. Data were analyzed using the Bland and Altman method (BA), correlation and regression. Results We found a strong correlation between measurements obtained by a non-expert and an expert echocardiographer and detected that an inexperienced trainee can acquire VTI measurements from the suprasternal window view. Regarding agreement between CO measurements, data obtained showed a positive correlation and the Bland and Altman analysis presented a total variation of 38.9%. Conclusion Regarding accuracy, it is likely that TTE (Transthoracic Echocardiogram) measurements of CO from the suprasternal window view are comparable to other minimally invasive techniques currently available. Due to its user-friendliness and low cost, it can be a convenient technique for obtaining perioperative hemodynamic measurements, even by inexperienced operators.

Research progress on emerging biomarkers in kidney transplantation / 器官移植

The hosts could show complex and diverse immune responses to the allografts. Whether biomarkers can be employed to explain the complexity of graft immune responses and the degree of disease damage are of significance. Conventional biomarkers, such as estimated glomerular filtration rate and blood concenrtation of immunosuppressant, lack of sensitivity and specificity in accurately identifying between immune and non-immune renal allograft injuries. Although renal biopsy is the "gold standard" for the diagnosis of postoperative complications, it still has disadvantages, such as invasiveness and high price, etc. Emerging biomarkers have potential advantages in the non-invasive diagnosis of subclinical injury of renal allograft, prediction of treatment response and individualized adjustment of immunosuppressive regimen. In this article, emerging biomarkers including blood, urine and tissue biomarkers that have been applied and are expected to be applied in clinical practice in the field of kidney transplantation were reviewed, and the range of application and effect of these biomarkers were evaluated, aiming to promote appropriate and rational application of these promising emerging biomarkers in clinical practice.

C-Peptides for diagnostics and therapy: a veterinary medicine point of view / Peptídeos-C para diagnóstico e terapia: um ponto de vista na medicina veterinária

Empirical studies proved that C-peptides are performing numerous intrinsic biological roles, and serve as a marker for pancreatic performance analysis. Since the last decade, C-peptide assays for differential diagnosis in veterinary diabetic patients are becoming more available, but still only for a very limited number of species. Studies on C-peptide as a diagnostic tool, therapy for associated complications, or as replacement therapies for C-peptide deficiency still showed not to be a common practice in veterinary medicine. This review was conducted to determine the potential importance of C-peptide in Veterinary Medicine, relevant in the diagnosis of diabetes and for other metabolic processes, as well as its proposed therapeutic benefits. Numerous articles were identified that reported positive results in their experimental studies, whether C-peptide as a biomarker for pancreatic performance in dogs, cats, and horses, as a non-invasive method to monitor nutritional status in primates, or to investigate its potential therapeutic benefits for diabetes-related illnesses.(AU)

Os estudos empíricos provaram que o peptídeo C realiza várias funções biológicas intrínsecas e serve também como um marcador para a análise de desempenho do pâncreas. Nesta última década os ensaios peptídeo C para o diagnóstico diferencial em doentes diabéticos veterinários estão mais disponíveis, contudo apenas em um limitado número de espécies. Estudos sobre C-peptídeo como ferramenta de diagnóstico, terapia de complicações associadas ou como terapias de reposição na sua deficiência ainda não é prática comum na Medicina Veterinária. Esta avaliação foi realizada para determinar a importância potencial de peptídeo C na Medicina Veterinária, relevante no diagnóstico de diabetes e também em outros processos metabólicos, assim como os benefícios terapêuticos propostos. Foram identificados numerosos artigos que reportaram resultados positivos nos seus estudos experimentais, quer o peptídeo C fosse utilizado como biomarcador para o desempenho do pâncreas em cães, gatos e cavalos, como um método não invasivo para monitorar o estado nutricional em primatas, quer para investigar o seu potencial terapêutico benéfico para doenças relacionadas ao diabetes.(AU)

Comparison of two methods for glucocorticoid evaluation in maned wolves / Comparação de dois métodos para avaliação de glicocorticóides em lobos guarás

Analysis of faecal glucocorticoid metabolites provides a powerful noninvasive tool for monitoring adrenocortical activity in wild animals. However, differences regarding the metabolism and excretion of these substances make a validation for each species and sex investigated obligatory. Although maned wolves (Chrysocyon brachyurus) are the biggest canids in South America, their behaviour and physiology are poorly known and they are at risk in the wild. Two methods for measuring glucocorticoid metabolites in maned wolves were validated: a radio- and an enzyme immunoassay. An ACTH challenge was used to demonstrate that changes in adrenal function are reflected in faecal glucocorticoid metabolites. Our results suggest that both methods enable a reliable assessment of stress hormones in maned wolves avoiding short-term rises in glucocorticoid concentrations due to handling and restraint. These methods can be used as a valuable tool in studies of stress and conservation in this wild species.

A análise de metabólitos de glicocorticóides fecais é uma ferramenta não-invasiva poderosa para o monitoramento da atividade adrenal em animais silvestres. Entretanto, diferenças no metabolismo e na excreção dessas substâncias tornam obrigatória a validação desse método para cada espécie e sexo investigado. Embora os lobos guarás (Chrysocyon brachyurus) sejam os maiores canídeos da América do Sul, seu comportamento e fiisiologia são ainda pouco conhecidos e estes animais são ameaçados. Dois métodos para mensuração de metabólitos de glicocorticóides em lobos guarás foram validados: um radio- e um enzima- imuno-ensaio. Um desafiio de ACTH foi usado para demonstrar que alterações no funcionamento adrenal podem ser detectadas nas concentrações metabólitos de glicocorticóides fecais. Nossos resultados sugerem que ambos os métodos possibilitam uma avaliação confiiável dos hormônios relacionados ao estresse em lobos guarás, evitando assim aumentos de curta duração nas concentrações glicocorticóides, devidos ao manejo e contenção. Esses métodos podem ser usados como uma ferramenta valiosa em estudos de estresse e conservação com essa espécie silvestre.

Validação de um radioimunoensaio para a quantificação de metabólitos fecais de testosterona em hamster Sírio (Mesocricetus auratus) / Validation of a radioimmunoassay for the quantification of fecal testosterone metabolites in the Syrian hamster (Mesocricetus auratus)

Modelo para o estudo de diversas doenças humanas, o hamster tem sido objeto de numerosos estudos comportamentais e envolvendo estresse e/ou comportamento agonístico que supõem, muitas vezes, o monitoramento das flutuações hormonais nos indivíduos envolvidos. O objetivo do presente trabalho foi confirmar a adequação de um conjunto comercial para dosagem de testosterona em sangue humano para a quantificação de metabólitos fecais de testosterona (MFT) em hamsters Sírios machos e fêmeas. Dez machos foram submetidos a um desafio com um agonista de GnRH para estimular a atividade testicular, elevando os níveis circulantes de testosterona. Cinco fêmeas receberam uma injeção de testosterona enquanto cinco outras receberam uma injeção de solução salina. Amostras de fezes coletadas antes e depois dos procedimentos, assim como amostras fecais de 20 fêmeas gestantes coletadas ao longo da gestação foram analisadas com um conjunto comercial para radioimunoensaio. Um pico de MFT 12h após a injeção seguido de uma queda abaixo do nível basal comprovou que, nos machos, as alterações nos níveis de MFT refletem as alterações da concentração de testosterona no sangue. Nestes observou-se um ciclo circadiano das concentrações de MFT com acrofase no início do período claro correspondendo ao ciclo descrito para as concentrações sanguíneas na literatura. Nas fêmeas a administração de testosterona exógena provocou uma elevação importante dos níveis de MFT, mas as concentrações medidas ao longo da gestação não refletiram o padrão dos níveis sanguíneos do hormônio endógeno. O conjunto para radioimunoensaio para testosterona em sangue humano mostrou-se adequado para o monitoramento da função testicular no hamster macho, mas um ensaio mais específico seria necessário para as fêmeas.

Besides being models for a variety of human diseases, hamsters have been object of numerous behavioral studies about stress and agonistic behavior. Such studies usually involve hormone change monitoring. The aim of the present study was to confirm the suitability of a commercial kit for human serum testosterone analysis to quantify testosterone metabolites in the feces (MFT) of male and female Syrian hamsters. Ten males were submitted to a GnRH challenge test to stimulate testicular activity and increase circulating testosterone levels. Five females received a testosterone injection and five other females were given a saline injection. Fecal samples collected before and after the procedures, and fecal samples collected from 20 pregnant females through gestation were analyzed for MFT with a commercial radioimmunoassay. The detection of a MFT peak 12 h after GnRH administration followed by a decrease under baseline showed that, in males, changes in the levels of MFT are related to respective changes of testosterone concentrations in the blood. Again in males a circadian cycle of MFT similar to the circadian rhythm described in literature for blood concentrations was detected. The administration of exogenous testosterone caused in females a dramatic peak of MFT. However, the concentrations measured through gestation did not reflect the pattern of endogenous testosterone blood levels as described in the literature. Therefore, the use of a radioimmunoassay for human blood testosterone was validated in male Syrian hamster, but a more specific assay would be necessary for female hamsters.

Non-invasive monitoring of acute rejection after heart transplantation / 医学研究生学报

Heart transplantation(HT) has been an effective method to treat end-stage heart disease, one main factor affecting the long-term survival rate is acute and/or chronic rejection after HT. Trans internal jugular endomyocardial biopsy(EMB) has been the "gold standard" to judge the rejection after HT, but it is also limited. Electrocardiogram ,echocardiogram, immunological monitoring and imaging monitoring can judge the rejection after HT and induce the EMB.

A Study on The Effect of Hyperoxia on EKG Findings of Rabbits / 예방의학회지

To investigate the effect of hyperoxia on EKG findings and to evaluate the applicability of EKG as noninvasive monitoring index of oxygen toxicity, 38 rabbits were continuously exposed to 6 different conditions-3 hyperbaric oxygenations (HBO-2.5, 3.5 and 5ATA, 100% O2), normobaric oxygenation (NBO, 100% O2), hyperbaric aeration (HBA-5ATA, 21% O2) and normobaric aeration (NBA, 21% O2)-for 120 minutes and their EKG and time to dyspnea and convulsion were recorded. Dyspnea and death were observed in exposure conditions of HBO-3.5 and HBO-5 (Positive rate of dyspnea; 10%, 100%, death; 10%, 25%, respectively) only, and convulsion in 4 oxygenation groups (NBO; 20%, HBO-2.5; 20%, HBO-3.5; 20%, HBO-5; 88%). Abnormal EKG findings included arrhythmia and ST-T changes and the incidences was increasing with doses(partial pressure of oxygen). In addition to EKG change, findings observed during exosure were dyspnea and convulsion in the order of appearence and when non specific ST-T change was accepted as positive (abnormal) finding, the frequency of abnormal EKG was statistically significant(p0.05). These results suggest that the effect of hyperoxia on heart is myocardial ischemia and arrhythmia, that oxygenation more than 3.5ATA causes myocardial damage in 120 minutes exposure, and that EKG is valuable as monitoring index of oxygen toxicity.