诊断学教案书写体会

教案书写是教师上课的总体设计和思路的书面反映，是高质量课堂教学的保障。文章结合作者自己的诊断学教学实践，从教学目标、重点难点、教学方法、教学过程、课后记五个方面总结了教案书写的心得体会。     

Validation of the GeneXpert Xpress SARS-CoV-2 PCR assay using saliva as biological specimen

In the pandemic, rapid and accurate detection of SARS-CoV-2 is crucial in controlling the outbreak. Recent studies have shown a high detection rate using saliva/oral fluids as specimens for laboratory detection of the virus. We intended to evaluate the test performance of the Xpert Xpress SARS-CoV-2 cartridge assay in comparison to a conventional qRT-PCR testing, using saliva as biological specimen. Forty saliva samples from symptomatic participants were collected. Conventional qRT-PCR was performed for amplification of E and RdRp genes and the Xpert Xpress SARS-CoV-2 assay amplified E and N2 genes. In the conventional assay, the median cycle threshold value of the E gene was 34.9, and of the RdRp gene was 38.3. In the Xpert Xpress assay, the median cycle threshold value of the E gene was 29.7, and of the N2 gene was 31.6. These results can allow a broaden use of molecular tests for management of COVID-19 pandemic, especially in resources-limited settings.     

NTRK-Fusions – A new kid on the block

The neurotrophic tyrosine receptor kinases (NTRK) play an important role in the development and function of the nervous system. Fusions involving NTRK and a wide range of genes that act as fusion partners are oncogenic and activate well-known signal transduction pathways like the MAPK-ERK pathway. NTRK fusions occur in many very different tumor entities in children and youth as well as in adults. There are a few tumors like secretory breast cancer and congenital fibrosarcoma for which NTRK fusions are pathognomonic. At the same time there a large number of tumors in which NTRK fusions occur in very rare frequency (e.g., lung cancer). TRK inhibitors offer now the possibility to use NTRK fusion as antitumorigenic targets in a tumor agnostic fashion regardless of the basic histology. It is the task of modern pathology to identify such targetable fusions in a highly effective and efficient manner.     

Performance of lipid fingerprint-based MALDI-ToF for the diagnosis of mycobacterial infections

ObjectivesBacterial diagnosis of mycobacteria is often challenging because of the variability of the sensitivity and specificity of the assay used, and it can be expensive to perform accurately. Although matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) has become the workhorse of clinical laboratories, the current MALDI methodology (which is based on cytosolic protein profiling) for mycobacteria is still challenging due to the number of steps involved (up to seven) and potential biosafety concerns. Knowing that mycobacteria produce surface-exposed species-specific lipids, we here hypothesized that the detection of those molecules could offer a rapid, reproducible and robust method for mycobacterial identification.MethodsWe evaluated the performance of an alternative methodology based on characterized species-specific lipid profiling of intact bacteria, without any sample preparation, by MALDI MS; it uses MALDI-time-of-flight (ToF) MS combined with a specific matrix (super-2,5-dihydroxybenzoic acid solubilized in an apolar solvent system) to analyse lipids of intact heat-inactivated mycobacteria. Cultured mycobacteria are heat-inactivated and loaded directly onto the MALDI target followed by addition of the matrix. Acquisition of the data is done in both positive and negative ion modes. Blinded studies were performed using 273 mycobacterial strains comprising both the Mycobacterium tuberculosis (Mtb) complex and non-tuberculous mycobacteria (NTMs) subcultured in Middlebrook 7H9 media supplemented with 10% OADC (oleic acid/dextrose/catalase) growth supplement and incubated for up to 2 weeks at 37°C.ResultsThe method we have developed is fast (<10 mins) and highly sensitive (<1000 bacteria required); 96.7% of the Mtb complex strains (204/211) were correctly assigned as MTB complex and 91.7% (22/24) NTM species were correctly assigned based only on intact bacteria species-specific lipid profiling by MALDI-ToF MS.ConclusionsIntact bacterial lipid profiling provides a biosafe and unique route for rapid and accurate mycobacterial identification.     

Diagnostic power of VEGF,MMP-9 and TIMP-1 in patients with breast cancer. A multivariate statistical analysis with ROC curve

PurposeVascular endothelial growth factor is an important factor in promoting angiogenesis in malignant processes, matrix metalloproteinase-9 in the degradation of extracellular matrix, which enhances metastasis, and tissue inhibitor of metalloproteinase-1 is its inhibitor. The aim of this study was to investigate the diagnostic power of these parameters in comparison to CA15-3 in breast cancer patients and in relation to the control group.Materials/methodsThe study included 120 breast cancer patients, 60 patients with benign breast tumors and 60 healthy women. Plasma levels of tested parameters were determined by enzyme-linked immunosorbent assay, CA15-3 by chemiluminescent microparticle immuno assay.ResultsTissue inhibitor of metalloproteinase-1 showed the highest value of sensitivity in breast cancer group (86.25%) and, more importantly, highest value in breast cancer stage I (85%). Vascular endothelial growth factor also showed high sensitivity (stage I and II–75%, III–85%, IV–70% and 76.25% in total breast cancer group) and the highest specificity (85%) from all tested parameters. It was also the only parameter which had statistically significant area under curve in all stages. In the total breast cancer group all tested parameters showed statistically significant area under curve, but the maximum range was obtained for combination: ‘vascular endothelial growth factor + CA15-3′. Vascular endothelial growth factor seems to be the best candidate for diagnosing breast cancer stage I and for differentiating between breast cancer and non-carcinoma cases.ConclusionsThe combined analysis of tested parameters and CA15-3 resulted in an increase in sensitivity and area under curve values, which provides hope for developing new panel of biomarkers that may be used in diagnosing breast cancer in the future.