Dendritic cells (DCs) are potent antigen presenting cells (APCs) that possess the ability to stimulate naïve T cells. They comprise a system of leukocytes widely distributed in all tissues, especially in those that provide an environmental interface. DCs posses a heterogeneous haemopoietic lineage, in that subsets from different tissues have been shown to posses a differential morphology, phenotype and function. The ability to stimulate naïve T cell proliferation appears to be shared between these various DC subsets. It has been suggested that the so-called myeloid and lymphoid-derived subsets of DCs perform specific stimulatory or tolerogenic function, respectively. DCs are derived from bone marrow progenitors and circulate in the blood as immature precursors prior to migration into peripheral tissues. Within different tissues, DCs differentiate and become active in the taking up and processing of antigens (Ags), and their subsequent presentation on the cell surface linked to major histocompatibility (MHC) molecules. Upon appropriate stimulation, DCs undergo further maturation and migrate to secondary lymphoid tissues where they present Ag to T cells and induce an immune response. DCs are receiving increasing scientific and clinical interest due to their key role in anti-cancer host responses and potential use as biological adjuvants in tumour vaccines, as well as their involvement in the immunobiology of tolerance and autoimmunity.
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Purple Urine - Purple discoloration can occur in alkaline urine as a result of the degradation of indoxyl sulfate (indican), a metabolite of dietary tryptophan, into indigo (which is blue) and indirubin (which is red) by bacteria such as Providencia stuartii, Klebsiella pneumoniae, P. aeruginosa, Escherichia coli, and enterococcus species.
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Deinococcus radiodurans, a radioresistant extremophile. It can survive cold, dehydration, vacuum, and acid, and is therefore known as a polyextremophile and has been listed as the world’s toughest bacterium.
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Mycobacterium tuberculosis, the causative agent of one of the most prevalent and wide spread diseases in the world - tuberculosis (also referred to as consumption). this is the macroscopic appearance of M. tuberculosis grown on a solid medium. the “raspberry” colonies are formed because the bacteria have a waxy mycolic acid coat, and because they are such slow growers; it can take upwards of a week for colony formation on agar. ——————————————————————————————————————— Giardia lamblia - Freshwater parasite that causes all sorts of fun: bloating, flatulence, diarrhea and steatorrhea (your body can’t absorb fat so you just pass it out; you become malnourished). ——————————————————————————————————————— Entamoeba histolytica - Intestinal parasite that infects human through a fecal-oral route and causes dysentery (yeah, like on Oregon Trail). Bloody diarrhea, liver abscesses and rapid weight loss accompany this little friend, making it the greatest crash diet in the history of mankind. ——————————————————————————————————————— Motor neuron. ——————————————————————————————————————— The skeletal system is made up of bones linked together by tendons, ligaments and muscles. Babies have around 328 bones, but adults have 206. Bones are made out of cells called osteocytes. ——————————————————————————————————————— ———————————————————————————————————————
