抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

https://www.um.es/biomybiotec/web/Seminarios/2010/papers/Cano_2.pdf

Epithelial-Mesenchymal Transitions in Development and Disease

The secretion of glucocorticoids (GCs) is a classic endocrine response to stress. Despite that, it remains controversial as to what purpose GCs serve at such times. One view, stretching back to the time of Hans Selye, posits that GCs help mediate the ongoing or pending stress response, either via basal levels of GCs permitting other facets of the stress response to emerge efficaciously, and/or by stress levels of GCs actively stimulating the stress response. In contrast, a revisionist viewpoint posits that GCs suppress the stress response, preventing it from being pathologically overactivated. In this review, we consider recent findings regarding GC action and, based on them, generate criteria for determining whether a particular GC action permits, stimulates, or suppresses an ongoing stressresponse or, as an additional category, is preparative for a subsequent stressor. We apply these GC actions to the realms of cardiovascular function, fluid volume and hemorrhage, immunity and inflammation, metabolism, neurobiology, and reproductive physiology. We find that GC actions fall into markedly different categories, depending on the physiological endpoint in question, with evidence for mediating effects in some cases, and suppressive or preparative in others. We then attempt to assimilate these heterogeneous GC actions into a physiological whole. (Endocrine Reviews 21: 55‐ 89, 2000)

/pdf/how-do-glucocorticoids-influence-stress-responses-4egr3fa2k0.pdf

How do glucocorticoids influence stress responses? Integrating permissive, suppressive, stimulatory, and preparative actions.

The clinical performance of a laboratory test can be described in terms of diagnostic accuracy, or the ability to correctly classify subjects into clinically relevant subgroups. Diagnostic accuracy refers to the quality of the information provided by the classification device and should be distinguished from the usefulness, or actual practical value, of the information. Receiver-operating characteristic (ROC) plots provide a pure index of accuracy by demonstrating the limits of a test's ability to discriminate between alternative states of health over the complete spectrum of operating conditions. Furthermore, ROC plots occupy a central or unifying position in the process of assessing and using diagnostic tools. Once the plot is generated, a user can readily go on to many other activities such as performing quantitative ROC analysis and comparisons of tests, using likelihood ratio to revise the probability of disease in individual subjects, selecting decision thresholds, using logistic-regression analysis, using discriminant-function analysis, or incorporating the tool into a clinical strategy by using decision analysis.

/pdf/receiver-operating-characteristic-roc-plots-a-fundamental-1bsmhsp7j4.pdf

Receiver-operating characteristic (ROC) plots: a fundamental evaluation tool in clinical medicine.

The transdifferentiation of epithelial cells into motile mesenchymal cells, a process known as epithelial-mesenchymal transition (EMT), is integral in development, wound healing and stem cell behaviour, and contributes pathologically to fibrosis and cancer progression. This switch in cell differentiation and behaviour is mediated by key transcription factors, including SNAIL, zinc-finger E-box-binding (ZEB) and basic helix-loop-helix transcription factors, the functions of which are finely regulated at the transcriptional, translational and post-translational levels. The reprogramming of gene expression during EMT, as well as non-transcriptional changes, are initiated and controlled by signalling pathways that respond to extracellular cues. Among these, transforming growth factor-β (TGFβ) family signalling has a predominant role; however, the convergence of signalling pathways is essential for EMT.

Molecular mechanisms of epithelial–mesenchymal transition

Povidone-iodine ("Betadine") disinfectant as a source of error.

This study explores if assay of cancer antigen 125 (CA 125) in maternal serum might aid the detection of Down's syndrome in the second trimester of pregnancy. CA 125 levels were determined retrospectively in stored maternal serum samples from ten Down's syndrome pregnancies and 78 controls matched for gestational and maternal age. In addition, second-trimester amniotic fluid samples from nine Down's syndrome and 109 unaffected pregnancies were analysed for CA 125. Maternal serum CA 125 values for Down's syndrome pregnancies were lower, with the median being 0.72 multiples of the unaffected population median. The medians for affected and unaffected pregnancies did not differ significantly and there was a considerable overlap in the range of values of cases and controls. The distribution of amniotic fluid CA 125 levels for Down's syndrome pregnancies resembled that for controls. From our present results, we could not find an association between Down's syndrome and second-trimester maternal serum or amniotic fluid CA 125 levels.

Second-trimester cancer antigen 125 and Down's syndrome.

The frequency of the luteinized unruptured follicle (LUF) was determined in a population of 220 regularly cycling women, infertile for at least two years. Laparoscopy was performed during the very first days of the luteal phase. In 26 women without other demonstrable cause of infertility, a diagnosis of LUF was made based on the absence of an ovulation stigma and the low concentrations of progesterone (P) and 17 beta-oestradiol (E2) in peritoneal fluid (PF). Twenty of these 26 women underwent a culdocentesis 72-96 hours after the serum LH-rise in a following cycle. In 19 out of 20, low P and E2 concentrations in PF were again found, suggesting the recurrence of LUF. Subsequently, ovulation was induced with human menopausal gonadotrophins (hMG) alone (n = 4), or in combination with human chorionic gonadotrophin (hCG, n = 9). At carefully timed culdocentesis (at LH/hCG + 72-96 hours), P concentration in PF was high in the hMG-hCG treated women but remained low in those given hMG alone. The combination of hMG and hCG may be a valuable treatment of LUF.

Incidence, recurrence and treatment of the luteinized unruptured follicle syndrome.

Using a standard brachial or femoral approach we inserted disposable catheters into the right (venous) and left (arterial) sides of the heart after the patients had been given lorazepam as premedication. Patients with chest pain also underwent maximum incremental atrial pacing with continuous monitoring by 12 lead electrocardiography. During catheterisation all patients with coronary artery and mitral valve disease were insensitive to movement of the catheter. In contrast, six of the seven patients with syndrome X and all four patients with chest pain and normal coronary arteries, although unaware of arterial catheterisation, experienced spontaneous but shortlived chest pain similar to that ofwhich they had previously complained when the venous catheter was moved within the proximal 3-5 cm of the superior vena cava and the entire right atrium. This pain was consistently and rapidly provoked by turning and forward and backward movements of the catheter. As the venous catheters were moved within the vascular sheaths the patients were not aware of movements of the catheter through the skin. The inferior vena cava, right ventricle, pulmonary artery, and coronary sinus were also not sensitive to movement of the catheter. Injection of 10 ml saline into the right atrium briefly provoked anginal pain, but a second and third injection did not; incremental increases in the volume of saline injected did not provoke pain until 50 ml was injected, when six out of 11 patients felt pain. Throughout the procedure there were no changes in right atrial pressure or the electrocardiograms.

https://www.bmj.com/content/bmj/296/6616/171.full.pdf

A. Van Steirteghem

Papers

Povidone-iodine ("Betadine") disinfectant as a source of error.

Second-trimester cancer antigen 125 and Down's syndrome.

Incidence, recurrence and treatment of the luteinized unruptured follicle syndrome.

Hyperthyroidism after gonadotrophic ovarian stimulation.

The role of USP9Y and DBY in infertile patients with severely impaired spermatogenesis