输血医学研究

从Landsteiner发现ABO血型系统以来,输血医学研究的发展已经远远超出ABO系统的范畴,包括Levine和Stetson对HDN的研究;Waiter研制的塑料采血袋为成分输血疗法提供可能;能更有效地提取血浆白蛋白、免疫球蛋白及凝血因子复合物浓缩制剂的Cohn血浆分离技术;数百种红细胞抗原的发现;可用于预防HDN的Rh免疫球蛋白的研制;1960年代研制的制备血液成分的血细胞分离机;经血液传播疾病的认识与预防以及HPCs作为血液成分的应用等。     

Stress as a mnemonic filter: Interactions between medial temporal lobe encoding processes and post‐encoding stress

Acute stress has been shown to modulate memory for recently learned information, an effect attributed to the influence of stress hormones on medial temporal lobe (MTL) consolidation processes. However, little is known about which memories will be affected when stress follows encoding. One possibility is that stress interacts with encoding processes to selectively protect memories that had elicited responses in the hippocampus and amygdala, two MTL structures important for memory formation. There is limited evidence for interactions between encoding processes and consolidation effects in humans, but recent studies of consolidation in rodents have emphasized the importance of encoding “tags” for determining the impact of consolidation manipulations on memory. Here, we used functional magnetic resonance imaging in humans to test the hypothesis that the effects of post‐encoding stress depend on MTL processes observed during encoding. We found that changes in stress hormone levels were associated with an increase in the contingency of memory outcomes on hippocampal and amygdala encoding responses. That is, for participants showing high cortisol reactivity, memories became more dependent on MTL activity observed during encoding, thereby shifting the distribution of recollected events toward those that had elicited relatively high activation. Surprisingly, this effect was generally larger for neutral, compared to emotionally negative, memories. The results suggest that stress does not uniformly enhance memory, but instead selectively preserves memories tagged during encoding, effectively acting as mnemonic filter. © 2016 Wiley Periodicals, Inc.     

Watermelon and ragweed share allergens

A biotin-avidin amplified ELISA was used to measure antigen-specific IgE for ragweed, representative members of the gourd family (watermelon, cantaloupe, honeydew melon, zucchini, and cucumber), and banana in the sera of 192 allergic patients, each with an IgE greater than or equal to 180 microns/ml. Sixty-three percent (120/192) of the sera contained antiragweed IgE, and of these patients, 28% to 50% contained IgE specific for any single gourd family member. In contrast, no greater than 11% of the sera positive for a given gourd or banana were negative for ragweed. Correlations between ragweed and gourd-specific IgE levels were significant (p less than 0.001), and correlation coefficients between any two gourds exceeded 0.79. In an ELISA system, the extracts of watermelon and ragweed inhibited each other in a dose-dependent manner; the resulting nonparallel inhibition curves indicate that some, but not all, of the allergens in the two extracts are cross-reactive. Isoelectric focusing of watermelon and ragweed extracts in narrow range gel (pH 4 to 6) followed by immunoblotting demonstrated six watermelon allergen bands with isoelectric points identical to those of ragweed allergens. Several remaining bands in the two extracts had differing isoelectric points, however. Six of 26 patients interviewed with watermelon-specific IgE reported developing oropharyngeal symptoms (itching and/or swelling of the lips, tongue, or throat) after ingesting at least one of the study foods, whereas only one of 25 patients interviewed without detectable watermelon-specific IgE reported similar symptoms (p = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Enhancing patient autonomy with risk assessment and invasive diagnosis: an ethical solution to a clinical challenge

The purpose of this study was to describe a clinically based, ethically justified informed consent process for risk assessment and invasive genetic diagnosis that enhances patient autonomy. Appealing to the ethical principle of respect for the autonomy of pregnant women, we show that patients can exercise their autonomy meaningfully in the informed consent process in response to the offer of risk assessment (RA) and invasive diagnosis (ID) and in response to the results of risk assessment. All pregnant patients in the first trimester should be offered both RA and ID. Women will sort themselves, in response, into 4 groups; those who refuse both RA and ID, those who are uncertain about RA, those who accept RA, and those who accept ID. Women who proceed to RA will sort themselves, in response to its results, into 3 groups: women for whom the risk of aneuploidy is acceptable or unacceptable and women who are not certain whether such risk is acceptable. For this last group only, the informed consent process should present information about current controversies of first-trimester and second-trimester further testing to better assess risk. Clinical strategies are identified for the implementation of the varied responses of pregnant women to the offer of RA and ID. Autonomy-enhancing strategies for the evaluation of pregnancy provide the basis for solving the ethical challenge that is presented by the wide variety of evaluation techniques.     

Paraplegia after thoracic aortic occlusion: influence of cerebrospinal fluid drainage. Experimental and early clinical results

Paraplegia occurs in 6.5% to 40% of patients after repair of extensive thoracoabdominal aortic aneurysms requiring aortic clamping. This study aimed to determine whether drainage of cerebrospinal fluid (CSF) done before aortic cross-clamping could decrease the incidence of paraplegia in dogs. The descending thoracic aorta was clamped distal to the left subclavian artery for either 40 minutes (group I) or 60 minutes (group II). All control animals in group I (10) and group II (10) showed evidence of spinal cord injury with paraparesis or paraplegia. In contrast, 9 of 10 animals (90%) in group I and 7 of 10 animals (70%) in group II that had CSF drainage before aortic cross-clamping were neurologically normal (p less than 0.001 and p less than 0.01, respectively). Aortic pressure distal to the aortic cross clamp was the same in all groups; however, spinal cord perfusion pressure (distal aortic pressure minus CSF pressure) was significantly higher in neurologically normal animals (34 +/- 5 mm Hg, n = 15) compared with those with paraparesis (26 +/- 4 mm Hg, n = 8) or paraplegia (19 +/- 5 mm Hg, n = 8) (r = 0.871, p less than 0.001). This study demonstrates that drainage of CSF before thoracic aortic occlusion significantly increases spinal cord perfusion pressure and decreases the incidence of paraplegia. Limited early clinical experience suggests that CSF drainage may be a useful adjunct to prevent paraplegia in patients who are having repair of thoracoabdominal aortic aneurysms.