Volume 1

A text-book of human physiology : including histology and microscopical anatomy with special reference to the requirements of practical medicine / by L. Landois ; translated from the seventh German edition with additions by William Stirling.

Landois, L. (Leonard), 1837-1902. Lehrbuch der Physiologie des Menschen. English

Date:: 1891

Credit: A text-book of human physiology : including histology and microscopical anatomy with special reference to the requirements of practical medicine / by L. Landois ; translated from the seventh German edition with additions by William Stirling. Source: Wellcome Collection.

80/602 page 40

$FIBRIN AND ITS FACTORS. [SeC. 29. Fibrinogen adheres as a sticky deposit to the side of the vessel. It coagulates On account of their great similarity, both substances are not usually prepared from blood-plasma. Fibrinogen is prepared from serous transudations (pericardial, abdominal, I pleuritic fluid, or the fluid of hydrocele), which contam no hbnno- plastin. Fihrino-pladin is most readily prepared from sermn, m which theie is still plenty of fibrino-plastin, but no fibrinogen. i v r« / \ 2. Preparation of Fibrino-plastin, Serum-globulin, or Paraglobulm.-(a Dilute blood-serum with twelve times its volume of ice-cold water and almost neutralise it with acetic acid [add 4 drops of a 25 per cent, solution of acetic acid Tevery 120 c.c. of diluted serum] ; or (6) pass a stream of carbon dioxide through the diluted serum, which soon becomes turbid; after a time a fine white powder, serum is not precipitated either by adding acetic acid or by CO^. Hammarsten found however, that if crystals of magnesium sulphate be added to complete saturation, it precipitates the serum-globulin, but does not precipitate serum- albumin ; serum-globulin is more abundant than serum-albumm m the serum of the ox and horse, while in man and the rabbit the reverse obtains ; (compare § 62).\ Schmidt found that 100 c.c. of tlie serum of ox Mood yielded 07 to 0;8 grm. ; horse's seram 0 3 to 0^6 grm. of dry fibrino-plastin. Fibrino-plastin occurs not only m serum, but alsoTn red blood-?orpuscles, in the fluids of connective-tissue, and in the juices of the cornea. 3 Preparation of Fibrinogen.-This is best prepared from hydrocele fluid, although it may also be obtained from the fluids of serous cavities, e g., the pleura, pericardium, or' peritoneum. It does not exist in blood-serum although it does exist in bbod-plasma, lymph, and chyle, from which ^^^^^^^^^f fl^^^ stream of CO,, after the paraglobulin is precipitated, (a) Dilute ^3^^^^^f ^^^^^^ with ten to fifteen times its volume of water, and pass a stream of CO, through it for a lono' time, (b) Add powdered common salt to saturation to a serous transudation, when a sticky glutinous (not very abundant) precipitate of fibrinogen is obtained. FHammarsten and Eichwald find that, although paraglobulin and fibrinogen are soluble ni Is not precipitated until the amount of salt exceeds 20 per cent.] Properties of the so-called Fibrin-Factors.-They are insoluble in pure water, but dissolve in water containing 0 in solution Both are soluble an very dilute alkalies, e.g., caustic soda, and are precipitated from this «»If» ^0^^^^ are soluble in dilute saline solutions, e.g., of common salt-like all globuhns-but « a certain amount of common salt and some other salts, «.<?., MgSO,, be added ii excess they are precipitated. Very dilute hydrochloric acid dissolves them, but after leverll houls they become changed into a body resembhng syntonm or acid- albunün (5 249, III.). Fibrinogen held in solution by common salt coagulates at 52° to 55' 0 [Fredcricq finds the fibrinogen exists as s»cA in the plasma; it coa<nilates at 56° C, and the plasma thereafter is uncoagulable spontaneously.] 4 Preparation of the Fihrin-Ferment.-(a) Mix blood-serum (ox) with wenty tints its volume of strong alcohol, and after one month filter off the deposit thereby produced The deposit on the filter consists of coagulated msoluble albumin and the ferment; dry it carefully over sulphuric acid, and reduce to a powder. Triturate rram of the powder with 65 c.c. of water for ten niinutes, and filter. The ferment is dissolved by the water, and passes through the filter, while the coagulated albumin remains behind. rfM ram^ce'sMethod -Buchanan's washed blood-clot (p. 39) is digested in an 8 percent. soSioX^lm™ The solution so obtained possesses in an intense degree the properties of Schmidt's fibrin-ferment.]$