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

Background: Thyroid disease in pregnancy is a common clinical problem. Since the guidelines for the management of these disorders by the American Thyroid Association (ATA) were first published in 2...

https://www.thyca.org/download/document/486/PregnancyandPostpartum.pdf

2017 Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and the Postpartum

Essentiality Toxicity Carcinogenicity Lead(Pb) Exposure Toxicokinetics Toxicity Neurologic, Neurobehavioral, and Developmental Effects in Children Mechanisms of Effects on the Developing Nervous System Peripheral Neuropathy Hematologic Effects Renal Toxicity Lead and Gout Effects on Cardiovascular System Immunotoxicity Bone Effects Reproductive Effects Birth Outcomes Carcinogenicity Other Effects Dose Response Treatment Organic Lead Compounds Mercury (Hg) Exposure Disposition and Toxicokinetics Metabolic Transformation Cellular Metabolism Toxicology Biological Indicators Treatment Nickel (Ni) Exposure Toxicokinetics Essentiality Toxicity Nickel Carbonyl Poisoning Dermatitis Indicators of Nickel Toxicity

/pdf/toxic-effects-of-metals-2t2btb1i7f.pdf

Toxic effects of metals

The inhibitory effect of a marine-sponge toxin, okadaic acid, was examined on type 1, type 2A, type 2B and type 2C protein phosphatases as well as on a polycation-modulated (PCM) phosphatase. Of the protein phosphatases examined, the catalytic subunit of type 2A phosphatase from rabbit skeletal muscle was most potently inhibited. For the phosphorylated myosin light-chain (PMLC) phosphatase activity of the enzyme, the concentration of okadaic acid required to obtain 50% inhibition (ID50) was about 1 nM. The PMLC phosphatase activities of type 1 and PCM phosphatase were also strongly inhibited (ID50 0.1-0.5 microM). The PMCL phosphatase activity of type 2B phosphatase (calcineurin) was inhibited to a lesser extent (ID50 4-5 microM). Similar results were obtained for the phosphorylase a phosphatase activity of type 1 and PCM phosphatases and for the p-nitrophenyl phosphate phosphatase activity of calcineurin. The following phosphatases were not affected by up to 10 microM-okadaic acid: type 2C phosphatase, phosphotyrosyl phosphatase, inositol 1,4,5-trisphosphate phosphatase, acid phosphatases and alkaline phosphatases. Thus okadaic acid had a relatively high specificity for type 2A, type 1 and PCM phosphatases. Kinetic studies showed that okadaic acid acts as a non-competitive or mixed inhibitor on the okadaic acid-sensitive enzymes.

/pdf/inhibitory-effect-of-a-marine-sponge-toxin-okadaic-acid-on-44i5fv1et4.pdf

Inhibitory effect of a marine-sponge toxin, okadaic acid, on protein phosphatases. Specificity and kinetics

Zinc and immune function: the biological basis of altered resistance to infection.

The major cause of neonatal mortality and morbidity is preterm delivery in general ( 37 completed weeks) All samples were assessed for thyroid stimulating hormone, thyroperoxidase antibody, and thyroglobulin antibody Gravidas with high thyrotropin (TSH) levels had a greater than threefold increase in risk of very preterm delivery In some analyses, gravidas who tested positive for thyroglobulin antibody at entry to prenatal care also had a better than twofold increased risk of very preterm delivery There were no significant associations between TSH level or thyroglobulin antibody positivity and the risk of moderately preterm delivery

The thyroid and pregnancy: a novel risk factor for very preterm delivery.

The objective of this study was to determine the effects of a year of Zn supplementation on Zn concentrations in circulating cells and on cellular immune functions in the elderly. Subjects, aged 60-89, were given a placebo, 15 mg Zn, or 100 mg Zn daily for 12 months. All subjects also received a multivitamin/mineral supplement that contained no additional Zn. Blood samples were drawn and immune functions assessed prior to and at 3, 6, 12, and 16 months after beginning Zn supplementation. Subject diets were also assessed at each visit. Dietary folate, pyridoxine, alpha-tocopherol, copper, zinc, and magnesium were consistently below recommended intakes. Although plasma Zn increased significantly in the 100 mg Zn treatment group, concentrations of Zn in erythrocytes, mononuclear cells, polymorphonuclear leukocytes, and platelets were not significantly increased by zinc supplementation. Natural killer cell activity was transiently enhanced by the 100 mg/day dose of Zn. There was a progressive improvement in d...

Effects of one year of supplementation with zinc and other micronutrients on cellular immunity in the elderly.

Daily micronutrient supplements enhance delayed-hypersensitivity skin test responses in older people.

This study surveyed serum concentrations of vitamins, electrolytes, and trace elements in subjects seropositive for HIV-1 by ELISA and confirmatory Western blot. Thirty subjects (26 males, 4 females) were recruited at a hospital clinic. Seventeen were classified as having mild or severe ARC (AIDS-related complex), 7 had AIDS, and 6 were asymptomatic. Eight had experienced weight loss of 10 pounds or more in the past 6 months. Most (93%) were anergic to skin test antigens. Percentages of subjects with below normal plasma concentrations include: zinc-30%, calcium-27%, magnesium-30%, carotenes-31%, total choline-50%, and ascorbate-27%. Eighty-seven percent of the subjects had at least one abnormally low value. Percentages with above normal values include: folate-37% and carnitine-37%. Some subjects with above normal values for plasma vitamins reported self-supplementation, usually with large doses. The results suggest that one or more abnormally low concentrations of the plasma micronutrients studied here are likely to be present in the majority of HIV seropositive patients.

Micronutrient status and human immunodeficiency virus (HIV) infection.

Part I. Basic Concepts, Consumption, Deficiency, and Toxicity. The Essential Trace Elements and Minerals: Basic Concepts, John D. Bogden. Possibly Essential Trace Elements, Forrest H. Nielsen. Consumption of Trace Elements and Minerals by Preagricultural Humans, Stanley B. Eaton III and S. Boyd Eaton. Current Dietary Intakes of Trace Elements and Minerals, Jean A. T. Pennington. Laboratory Assessment of Trace Element and Mineral Status, David B. Milne. The Epidemiology of Trace Element Deficiencies, Roberto Masironi. Trace Element and Supplement Safety, John N. Hathcock. Part II. Trace Element and Mineral Nutrition in Healthy People. Trace Element and Mineral Nutrition in Human Pregnancy, Theresa O. Scholl and Thomas M. Reilly. Trace Element and Mineral Nutrition During Lactation, Mary Frances Picciano. Trace Element and Mineral Nutrition in Adolescents, Velimir Matkovic, Nancy E. Badenhop, Jasminka Z. Ilich. Trace Element Requirements in the Elderly, Ronni Chernoff. Part III. Trace Element and Mineral Nutrition in Disease. Genetic Disorders of Trace Element Metabolism, Gregory J. Anderson and Gordon D. McLaren. Trace Element and Mineral Nutrition in Endocrine Diseases, John T. Dunn. Trace Element and Mineral Nutrition in Skeletal Health and Disease, Robert P. Heaney. Trace Element and Mineral Nutrition in Ischemic Heart Disease, Leslie M. Klevay. Trace Element and Mineral Nutrition in Renal Disease, Saulo Klahr. Trace Element and Mineral Nutrition in Gastrointestinal Disease, Giacomo Carlo Sturniolo, Cinzia Mestriner, and Renata D'Inca. Immune Dysfunction in Iron, Copper, and Zinc Deficiencies, Adria R. Sherman. Trace Element and Mineral Nutrition in HIV Infection and AIDS: Implications for Host Defense, Susanna Cunningham-Rundles. Trace Element and Mineral Nutrition in Hospital, Surgical and Cancer Patients: Enteral and Parenteral Nutrition, M. A. Mohit-Tabatabai. Trace Element and Mineral Nutrition in Diseases of the Eye, George Edwin Bunce. Appendix: Journalsand Current Books. Index.

John D. Bogden

Papers

The thyroid and pregnancy: a novel risk factor for very preterm delivery.

Effects of one year of supplementation with zinc and other micronutrients on cellular immunity in the elderly.

Daily micronutrient supplements enhance delayed-hypersensitivity skin test responses in older people.

Micronutrient status and human immunodeficiency virus (HIV) infection.

Clinical nutrition of the essential trace elements and minerals : the guide for health professionals