Precipitins

Precipitins, specific products of animal organisms, arising in the blood serum of an animal after the introduction of foreign protein substances (see Precipitation). The discovery of precipitins is connected with observations concerning the parenteral introduction of bacterial proteins. Filtrates free from bacteria of broth cultures of cholera and typhus possess immunizing action; this is evident from the fact that as a result of their introduction in an animal, serum is obtained with the same agglutinating properties as from the injection of pure cultures (Widal, Lewy and others). This idea was further developed by Kraus (Kraus, 189?), who proved that sera of animals immunized with cultures of cholera, typhus and plague are capable of giving specific precipitates in filtrates free from macroorganisms of the same cultures. Kraus's research was confirmed by observations of other authors: Nicolle over the bacillus coli, Marmorek over streptococci. The formation of bacterial precipitins was first used for diagnostic purposes by Vladimirov, who found that serum of glandered horses, added to a filtrate of glandered culture, causes the formation of a precipitate. Plant proteins not of bacterial origin are also capable of causing the formation of precipitins. The introduction into the abdominal cavity of rabbits in the form of an infusion of ergot treated in a special way is accompanied by the formation of specific precipitins (Okolov and Akimov). Up to the present time it has been possible to obtain precipitins: 1) bacterial in relation to microbes of typhus, cholera, bacillus coli, plague, glanders, dysentery, anthrax, tbc, streptococci, pneumococci, capsular bacteria, Bac. prodigiosus, pyocyaneus, proteus, diphtheria, pseudodiphtheria, bacilli of tbc of rodents, yeasts and trypanosomes; 2) zooprecipitins in relation to serum, red blood corpuscles, snake venom, milk, various organs, semen, urine, chicken protein, animal parasites; 3) phytoprecipitins in relation to seeds of cereals, legumes, ricin, abrin, crotonin, opium, ergot, fungi and other plants. Among phytoprecipitins, the precipitin with ricin was first obtained. This proved that plant antigens can also be phytoxins. The latter differ from bacterial toxins by their origin, and from alkaloids by the fact that the latter do not possess antigenic properties. With great success, the precipitation reaction was used in relation to animal proteins. It is believed that precipitins are formed in leukocytes, the endothelium of vessels and in cells of the reticulo-endothelial system. The formation of precipitins is also influenced by the time of year. In winter, when animals feed on more monotonous food, the titer of precipitins is lower. Many rabbits in winter do not give precipitins at all. In summer, when animals feed on grass, they give stronger precipitins. It is indicated that preliminary blocking of the ret.-end. apparatus with a colloid solution of lead leads to increased formation of precipitins. All measures that destroy the structure of protein also destroy the structure of precipitins. Alkalies, acids, formalin have a harmful effect on precipitins. Pepsin and hydrochloric acid, as well as trypsin, destroy precipitins. At a temperature of 50-60° bacterial precipitins lose only the ability to cause precipitation, while retaining the ability to bind precipitinogen. A precipitin modified in this way is designated as precipitoid (Kraus, Pirquet). By analogy with opsonins, antitoxins and others, precipitins can be detected in normal serum - so-called 'normal' precipitins. Sera of some animals are capable of causing precipitation with sera of other animals. Many sera can give precipitates with bacterial extracts. Many consider normal precipitins as nonspecific and designate them as precipigireagens (Pfeiler). Animals with normal precipitins should not be used for the precipitation reaction. According to Kraus (Kraus), there are a number of precipitins in normal serum, which are probably as specific as artificially obtained precipitins. Lit.-see lit. to the article Precipitation. 3. Morgenstern. PRIAPISM (from Priaptis - in Greek mythology, god of gardens and fields, in a later period - god-patron of lust and sensual pleasures), a prolonged excited state of the penis, independent of libido and without passing into a relaxed state after sexual intercourse (unlike satyriasis). Priapism is usually accompanied by pain and is very distressing. Priapism can manifest in complete and incomplete erection. With complete erection, the pain reaches its highest degree, with incomplete erection there is no pain at all or it is weakly expressed. The causes of priapism can be: 1) prolonged and abnormal irritation of the sensitive nerves of the penis in inflammatory processes in the genitourinary apparatus, in local changes in the posterior urethra, stones of the bladder, hypertrophy of the prostate, acute cavernitis, neoplasms of the urethra, traumatic hemorrhages into the cavernous bodies, etc.; 2) abnormal processes of irritation of the erection center in the spinal cord in its lumbar region, e.g. in initial forms of tabes dorsalis, myelitis transversa, hemorrhages, injuries, etc.; 3) irritation of the cerebral cortex (epilepsy, etc.); 4) irritation of the vasodilator center in the medulla oblongata with transmission of irritation to the erection center. In its pure form, without a visible local or neurogenic cause, priapism is observed mainly in leukemia. The pathogenesis of these cases is rather obscure. The disease usually begins without any precursors, suddenly, often interrupting the patient's sleep in the middle of the night. The penis is in complete erection, with only its cavernous bodies being erect, while the corpus spongiosum of the urethra and the glans penis appear completely normal. The skin of the penis and the prepuce are slightly swollen and reddened. The pain gradually increases and becomes unbearable. Sometimes priapism lasts for several weeks, even months; eventually patients recover, but the ability to have an erection is almost always lost. Tarnovsky observed one patient with priapism for two years. The prognosis in leukemic priapism follows from the nature of the underlying disease. Priapism, depending on diseases of the central nervous system, does not lend itself to treatment as such and usually passes with the elimination or change in the nature of the underlying suffering. In all other cases, narcotics, bromine, lupulin, camphor, long sitz baths are prescribed. If priapism does not depend on any local suffering of the sexual organ, then the above-mentioned means at best only somewhat alleviate the patient's condition. If drug treatment is ineffective, resort is had to operation, which consists in the incision of both cavernous bodies and the expression of clotted blood from the tunica albuginea. The tunica albuginea and the skin are sewn up tightly. Immediately after the operation, the erection disappears, and the pain either completely disappears or is considerably weakened. The ability to have an erection after the operation is not completely restored in most cases. Prevention of priapism varies depending on the diversity of causal factors. It includes the elimination of local changes in the genitourinary apparatus, treatment of diseases of the nervous system in appropriate cases, etc.