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://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

Lipid peroxidation can be described generally as a process under which oxidants such as free radicals attack lipids containing carbon-carbon double bond(s), especially polyunsaturated fatty acids (PUFAs). Over the last four decades, an extensive body of literature regarding lipid peroxidation has shown its important role in cell biology and human health. Since the early 1970s, the total published research articles on the topic of lipid peroxidation was 98 (1970–1974) and has been increasing at almost 135-fold, by up to 13165 in last 4 years (2010–2013). New discoveries about the involvement in cellular physiology and pathology, as well as the control of lipid peroxidation, continue to emerge every day. Given the enormity of this field, this review focuses on biochemical concepts of lipid peroxidation, production, metabolism, and signaling mechanisms of two main omega-6 fatty acids lipid peroxidation products: malondialdehyde (MDA) and, in particular, 4-hydroxy-2-nonenal (4-HNE), summarizing not only its physiological and protective function as signaling molecule stimulating gene expression and cell survival, but also its cytotoxic role inhibiting gene expression and promoting cell death. Finally, overviews of in vivo mammalian model systems used to study the lipid peroxidation process, and common pathological processes linked to MDA and 4-HNE are shown.

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Lipid peroxidation: production, metabolism, and signaling mechanisms of malondialdehyde and 4-hydroxy-2-nonenal.

This review focuses on the role of oxidative processes in atherosclerosis and its resultant cardiovascular events. There is now a consensus that atherosclerosis represents a state of heightened oxidative stress characterized by lipid and protein oxidation in the vascular wall. The oxidative modification hypothesis of atherosclerosis predicts that low-density lipoprotein (LDL) oxidation is an early event in atherosclerosis and that oxidized LDL contributes to atherogenesis. In support of this hypothesis, oxidized LDL can support foam cell formation in vitro, the lipid in human lesions is substantially oxidized, there is evidence for the presence of oxidized LDL in vivo, oxidized LDL has a number of potentially proatherogenic activities, and several structurally unrelated antioxidants inhibit atherosclerosis in animals. An emerging consensus also underscores the importance in vascular disease of oxidative events in addition to LDL oxidation. These include the production of reactive oxygen and nitrogen species by vascular cells, as well as oxidative modifications contributing to important clinical manifestations of coronary artery disease such as endothelial dysfunction and plaque disruption. Despite these abundant data however, fundamental problems remain with implicating oxidative modification as a (requisite) pathophysiologically important cause for atherosclerosis. These include the poor performance of antioxidant strategies in limiting either atherosclerosis or cardiovascular events from atherosclerosis, and observations in animals that suggest dissociation between atherosclerosis and lipoprotein oxidation. Indeed, it remains to be established that oxidative events are a cause rather than an injurious response to atherogenesis. In this context, inflammation needs to be considered as a primary process of atherosclerosis, and oxidative stress as a secondary event. To address this issue, we have proposed an "oxidative response to inflammation" model as a means of reconciling the response-to-injury and oxidative modification hypotheses of atherosclerosis.

Role of Oxidative Modifications in Atherosclerosis

Practice guidelines in acute pancreatitis.

Lipids in health and disease.

Our understanding of the role of vitamin E in human nutrition, health, and disease has broadened and changed over the past two decades. Viewed initially as nature's most potent lipid-soluble antioxidant (and discovered for its crucial role in mammalian reproduction) we have now come to realize that vitamin E action has many more facets, depending on the physiological context. Although mainly acting as an antioxidant, vitamin E can also be a pro-oxidant; it can even have nonantioxidant functions: as a signaling molecule, as a regulator of gene expression, and, possibly, in the prevention of cancer and atherosclerosis. Since the term vitamin E encompasses a group of eight structurally related tocopherols and tocotrienols, individual isomers have different propensities with respect to these novel, nontraditional roles. The particular beneficial effects of the individual isomers have to be considered when dissecting the physiological impact of dietary vitamin E or supplements (mainly containing only the alpha-tocopherol isomer) in clinical trials. These considerations are also relevant for the design of transgenic crop plants with the goal of enhancing vitamin E content because an engineered biosynthetic pathway may be biased toward formation of one isomer. In contrast to the tremendous recent advances in knowledge of vitamin E chemistry and biology, there is little hard evidence from clinical and epidemiologic studies on the beneficial effects of supplementation with vitamin E beyond the essential requirement.

Chemistry and biology of vitamin E

Background: To assess in-hospital complication rates and survival duration after en bloc vascular resection (VR) for infiltration of pancreatic malignancies in major vessels. Methods: Between 1994 and 2005, 585 patients underwent potentially curative pancreatic resection without adjuvant chemotherapy. Four hundred forty-nine patients (77%) underwent standard oncologic resection (VR−), whereas 136 (23%) received VR (VR+). For calculation of in-hospital morbidity and mortality rates, all 136 patients who underwent VR were considered. In contrast, for survival analysis, only pancreatic adenocarcinoma patients (n = 100) were included. Results: One hundred twenty-eight VR+ patients underwent portal or superior mesenteric vein resection and 13 hepatic artery (HA) or superior mesenteric artery (SMA) resection. In 5 patients, synchronous VR addressing both the mesenterico-portal axis and either the HA or SMA was performed. In-hospital morbidity and mortality rates of VR− patients (39.7%/4.0%) nearly equaled that of VR+ patients (40.3%/3.7%). From the 100 patients with pancreatic adenocarcinoma, histopathology confirmed “true” vascular invasion in 77 patients. Twenty-three patients had peritumoral inflammation, mimicking tumor invasion. Median survival was 15 months (11.2–18.8) in patients with histopathologic proven vascular invasion and 16 months (14.0–17.9) in those without (P = 0.86). Two-year survival probabilities were 36% (without) versus 34% (with vascular invasion; P = 0.9). Among VR+ patients with histopathologically evidenced vascular invasion, 19 survived longer than 30 months, and 6 were still alive 5 years after surgery. Multivariate modeling identified nodal involvement (N1) and poor grading (G3) as the only predictors of decreased survival. Evidence of vascular invasion had no adverse impact on survival. Conclusion: Postoperative morbidity and mortality rates after en bloc VR are comparable with “standard” pancreatectomy procedures. Median survival of 15 months in patients with vascular invasion is superior to that of patients who undergo palliative therapy and nearly equals that of patients who are not in need for VR.

En bloc vascular resection for locally advanced pancreatic malignancies infiltrating major blood vessels: perioperative outcome and long-term survival in 136 patients.

Two Distinct Pathways of Formation of 4-Hydroxynonenal MECHANISMS OF NONENZYMATIC TRANSFORMATION OF THE 9- AND 13-HYDROPEROXIDES OF LINOLEIC ACID TO 4-HYDROXYALKENALS

Curcumin is the main bioactive ingredient in turmeric extract and widely consumed as part of the spice mix curry or as a dietary supplement. Turmeric has a long history of therapeutic application in traditional Asian medicine. Biomedical studies conducted in the past two decades have identified a large number of cellular targets and effects of curcumin. In vitro curcumin rapidly degrades in an autoxidative transformation to diverse chemical species, the formation of which has only recently been appreciated. This paper discusses how the degradation and metabolism of curcumin, through products and their mechanism of formation, provide a basis for the interpretation of preclinical data and clinical studies. It is suggested that the previously unrecognized diversity of its degradation products could be an important factor in explaining the polypharmacology of curcumin.

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Claus Schneider

Papers

Lipids in health and disease.

Chemistry and biology of vitamin E

En bloc vascular resection for locally advanced pancreatic malignancies infiltrating major blood vessels: perioperative outcome and long-term survival in 136 patients.

Two Distinct Pathways of Formation of 4-Hydroxynonenal MECHANISMS OF NONENZYMATIC TRANSFORMATION OF THE 9- AND 13-HYDROPEROXIDES OF LINOLEIC ACID TO 4-HYDROXYALKENALS

Degradation of Curcumin: From Mechanism to Biological Implications.