2017. november 4., szombat

Ötlet: a "growth factor" mintájára, amit mi keresünk, azt nevezzük el "aging factor"-nak !

Figure 22-15 (a) Location of the hypothalamus and pituitary gland. (b) Details of the hypothalamus-pituitary system. Signals arriving from connecting neurons stimulate the hypothalamus to secrete hormones destined for the anterior pituitary into a special blood vessel, which carries the hormones directly to a capillary network in the anterior pituitary. In response to each hypothalamic hormone, the anterior pituitary releases its appropriate hormone into the general circulation. Posterior pituitary hormones are made in neurons arising in the hypothalamus, transported in axons to nerve endings in the posterior pituitary, and stored there until released into the blood in response to a neuronal signal.

The hypothalamic hormones pass directly to the nearby pituitary gland through special blood vessels and neurons that connect the two glands (Fig. 22-15b). The pituitary gland has two functionally distinct parts. The anterior pituitary responds to hypothalamic hormones carried in the blood, by producing six tropic hormones or tropins (from the Greek tropos, meaning "turn"), relatively long polypeptides that activate the next rank of endocrine glands (Fig. 22-14). Adrenocorticotropic hormone (ACTH, also called corticotropin; Mr 4,500) stimulates the adrenal cortex; thyroid-stimulating hormone (TSH, also called thyrotropin; Mr 28,000) acts on the thyroid gland; follicle-stimulating hormone (FSH; Mr 34,000) and luteinizing hormone (LH; Mr 20,500) act on the gonads; and growth hormone (GH, also called somatotropin; Mr 21,500) stimulates the liver to produce several growth factors.

Lehninger-Nelson-Cox: Principles of Biochemistry, 752.o.

2017. október 29., vasárnap

Megvan, hogy az orvosok és az elméleti tudósok miért utasítják el a projektjavaslatomat ... Mert ez mérnöki feladat !

... These are only some of the more straightforward examples. Release of genetically engineered organisms into the environment carries with it a level of risk that is sometimes difficult to evaluate. Human gene therapy (Box 28-2), with all of its promise, doubtless will present society with ethical dilemmas not yet anticipated. Issues of this kind must in the end foster a closer and more productive collaboration between science and the society it serves, as well as higher levels of scientific literacy in the general public, as we move toward the twenty-first century.

Lehninger-Nelson-Cox: Principles of Biochemistry, 1010.o.

2017. október 6., péntek

Nem azért mondom, de ez elképesztő: az élet-technológia !

Ez nem csak úgy magától pöndörödik, ezt pöndöríteni kell ! ... Ez komplett gyártási folyamat:

In every cell, DNA supercoiling is a precisely regulated process that influences many aspects of DNA metabolism. Not surprisingly, there are enzymes in every cell whose sole purpose is to underwind and/or relax DNA. The enzymes that increase or decrease the extent of DNA underwinding are called topoisomerases, and the property of DNA they affect is the linking number. These enzymes play an especially important role in processes such as replication and DNA packaging. There are two classes of topoisomerases. Type 1 topoisomerases act by transiently breaking one of the two DNA strands, rotating one of the ends about the unbroken strand, and rejoining the broken ends; they change Lk in increments of 1. Type 2 topoisomerases break both DNA strands and change Lk in increments of 2.

Lehninger-Nelson-Cox: Principles of Biochemistry, 805.o.

Van egy rossz (vagy jó) hírem: a testünk alacsony hőmérsékleten működő gőzgép !

"Living cells are chemical engines that function at   constant temperature." Lehninger-Nelson-Cox: Principles of Biochemistry, ...