Gland thymus

Polychlorinated biphenyls (PCBs) zero 0.0005 Skin changes thymus gland problems immune deficiencies reproductive or nervous system difficulties increased risk of cancer Runoff from landfils discharge of waste chemicals... 

Bries, n. thymus, -eldrilse, /. thymus gland, briet, pret. (of braten) roasted, etc. 

In addition to antibodies, the immune system also consists of bone-marrow derived lymphocytes, or B cells, and T cells that come from the thymus gland, both of which (indirectly) produce antibodies. These cells, in turn, may be helped by helper cells (= H) and suppressed by suppressor cells (= S). Helper cells may be alarmed as to the presence of antigens by macrophages (= M) that eat the antigens and leave parts of their meal on their cell surface. 

Decreases the production of lymphocytes and eosinophils in the blood by causing atrophy of the thymus gland blocks the release of cytokines, resulting in a decreased performance of T and B monocytes in the immune response. (This action, coupled with the anti-inflammatory action, makes the corticosteroids useful in delaying organ rejection in patients with transplants.)... 

Although little epidemiological data exist for humans, most organotins, especially the dibutyl- and dioctyltins, have severe effects on the immune system of animals including premature atrophy of the thymus gland. The first observation was made by Seinen and Willems3 and a great deal of work has since been performed in this area. 

Mouse 0.2 mg/kg BW Reduces mammary tumor growth rate adversely affects thymus gland growth 22... 

T cells are lymphocytes produced by the thymus gland. There are two types of T cells involved in immune response CD4+ (CD positive, helper cells) and CD8 (CD positive, also called T killer, or suppressor, cells). When the APCs present the antigens to CD4+ helper T cells, the secretory function is activated and growth factors such as cytokines are secreted to signal the proliferation of CD8" killer cells and B cells. When the CD8" ... 

Children dying from malnutrition have been first noted in 1937 to have had a profound depletion of the thymus gland (V2). This has now been confirmed in several parts of the world (T6, W5). 

Simon, J., A Physiological Essay on the Thymus Gland Henry Renshaw, London, 1845. 

They consist of two sugars that are identical except that the deoxyribose contains a hydrogen on carbon 2 (thus the name deoxy or without one oxy or hydroxyl Figure 10.7). These specific compounds were originally obtained from yeast (DNA) and the thymus gland (RNA). 

PCB 0.0005 mg/L Skin change, thymus gland, immune deficiency... 

Thymosin is an immunomodulatory peptide produced by the thymus gland and other cells. Thymosin alfa 1, a 28-amino acid peptide, is one member of the family of thymosins that collectively appear to influence a variety of regulatory and counter-regulatory functions in terms of T-cell maturation and antigen recognition, stimulation of native interferons and cytokines such as interleukin-2, and activity of natural killer cell-mediated cytotoxicity. In some countries it is approved as an adjuvant for influenza vaccine or as a treatment for chronic hepatitis B and, in combination with interferon for hepatitis C. Thymosin alfa 1 has been used with some success to treat children with the severe form of Di-George Syndrome. 

Cholinesterase inhibitors—but not direct-acting acetylcholine receptor agonists—are extremely valuable as therapy for myasthenia. Patients with ocular myasthenia may be treated with cholinesterase inhibitors alone (Figure 7-4B). Patients having more widespread muscle weakness are also treated with immunosuppressant drugs (steroids, cyclosporine, and azathioprine). In some patients, the thymus gland is removed very severely affected patients may benefit from administration of immunoglobulins and from plasmapheresis. 

The amount of nucleic acid in tissues varies from 0.1% in yeast and 0.5-1% in muscle and in bacteria to 15-40% in thymus gland and sperm cells. In these latter materials of high nucleic acid content it is clear that multiplication of % N by 6.25 is not a valid measure of protein content. For diploid cells of the body the DNA content per cell is nearly constant. 

The discovery of deoxyribonucleic acid dates to 1869, when Miescher isolated a new chemical substance from white blood cells that he obtained from pus and later from sperm cells.3 The material, which became known as nucleic acid, occurred in both plants and animals, thymus glands and yeast cells being among the best sources. Chemical studies indicated that the nucleic acids isolated from thymus glands and from yeast cells were different. As we now know, thymus nucleic acid was primarily DNA and yeast nucleic acid primarily RNA. For a while it was suspected that animals contained only DNA and plants only RNA, and it was not until the early 1940s that it was established that both substances were present in all organisms.3 ... 

Terminal deoxyribo-nucleotide transferase Thymus gland, plants Limited 5 —> 3 chain growth template independent addition of tails to DNA fragments... 

B cells and T cells follow different pathways of development. In mammals, B lymphocytes mature in the bone marrow and then migrate to secondary lymphoid organs. On exposure to foreign substances known as antigens, they proliferate to produce immunoglobulins. T lymphocytes mature in the thymus gland. They also can be stimulated to proliferate by exposure to an appropriate antigen. 

Manson and Lampen243 reported that they obtained the phosphorolysis and arsenolysis of hypoxanthine desoxyriboside by enzyme preparations from calf-thymus gland and rat liver. An acid-stable phosphate ester was isolated as a product of phosphorolysis. Results to be outlined suggested that this ester was 2-desoxy-D-ribose 5-phosphate and evidence was obtained for its formation by a mutase type reaction from 2-desoxy-D-ribose 1-phosphate. This evidence was extended and reinforced when Manson and Lampen244 obtained indications for the formation of desoxy-D-ribose 1-phosphate during the phosphorolysis of thymidine. Consequently the conversions outlined may be depicted as shown. 

Kill two 6-wk-old Balb-c mice and remove their thymus glands asep-tically. 

Kill them and remove the thymus glands aseptically. 

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