Gold

GOLD (Aurum), chemical symbol Au, atomic weight 197.2; in the periodic system it occupies the 79th place, 9th in the 1st group; a very soft, highly ductile and malleable metal of a yellowish-red color; very thin leaves (gold leaf) are translucent with a bluish-green color; it melts at 1063° and above, forming a greenish liquid; specific gravity 19.32 at 13°; it is an excellent conductor of heat and electricity. Gold, as a typical noble metal, is not very active; it is incapable of oxidizing at any temperature, and its oxide decomposes upon heating; gold combines directly at ordinary temperatures with chlorine and bromine, forming the corresponding salts, and therefore it dissolves in chlorine water, aqua regia, and other liquids in which chlorine is generated; in the presence of O₂, it dissolves in potassium cyanide and, forming an amalgam, in mercury. Compounds of gold belong to two types—AuX and AuX₃; gold easily forms complex salts. In nature, it is found predominantly disseminated in quartz rocks (quartz veins) and in the form of gold placers—in Siberia, especially in the southern parts of the former Yeniseysk Governorate, in the Urals, in Alaska, in California, Mexico, in the southern parts of Africa and Australia, and in other places; the sand of many rivers also contains an insignificant amount of gold; gold has also been found in ocean water. Beginning in the 16th century, gold compounds (inorganic salts) began to be given therapeutic significance for various diseases. Numerous cases of poisoning even when taking small doses of these compounds, as well as the growing skepticism of physicians regarding the special (specific) action of gold, led to the fact that by the beginning of the 20th century, inorganic salts of gold had almost ceased to be used for the purpose of their general (resorptive) action; local use, however, was partially preserved as an antiseptic, astringent, anti-inflammatory, and caustic agent (e.g., for cancerous tumors). The local action of inorganic gold salts—astringent (anti-inflammatory) and caustic—depends on their ability to form so-called albuminates with the body's proteins, with the simultaneous release of acid and the action of the latter as well. The caustic action is limited. Metallic gold is almost not absorbed and is therefore non-toxic, whereas gold salts are absorbed by the gastrointestinal tract. In humans, during acute poisoning, the following have been described: salivation, a metallic taste in the mouth, black coloration of the teeth, vomiting, diarrhea with colic-like pains, albuminuria, skin rashes, a state of nervous system excitation, etc. No autopsy cases have been described. In animals during acute poisoning with gold salts, the same changes in organs were found as are known in poisoning with other heavy metals. In chronic poisoning in humans, phenomena of depression of the central nervous system, pain along the course of various nerves, in muscles, joints, and bones, increased sweating, catarrhal phenomena of the conjunctiva of the eye, gums, and respiratory tract, weight loss, painful spots on the skin (especially on the face), edema of the legs, etc., were noted. The strong antiseptic properties of inorganic gold salts were known relatively long ago, but their use for the purpose of resorptive bactericidal action could not be realized due to the strongly pronounced organotropic action. Attempts were made to achieve this goal by introducing colloidal gold into the body. Its use in acute septic states is often successful. With ordinary intravenous administration (weaker in the muscle), general and focal reactions are observed; the general reaction includes an increase in temperature followed by a drop below the initial level, initial leukopenia and lymphocytosis, and after them—polynuclear leukocytosis, a slight increase in pulse, a slight and transient decrease in blood pressure, etc.; focal reactions are expressed by an exacerbation of pathological processes in the diseased areas of the body. According to modern views, the favorable effect of colloidal gold can hardly be entirely attributed to the bactericidal action of the colloidal metal, the concentration of which in the body at therapeutic doses is too small for that. Rather, an indirect influence on the infectious agent takes place here (as with other colloidal metals) due to the strengthening of the body's protective forces, in particular thanks to hyperleukocytosis, the strengthening of the function of the reticulo-endothelial apparatus, and perhaps the activation of the protoplasm of all cells. Some authors explain this action by a disturbance of the colloidal equilibrium in the plasma caused by the electric charge of the compound. For diagnostic purposes (mainly in syphilis of the central nervous system), colloidal gold is used as a reagent in the Lange reaction. In recent years, gold has come to be widely used (for tuberculosis, syphilis, etc.) in the form of complex organic compounds. Preparations of this kind (Krysolgan, Triphal, Sanocrysin, Solganal, etc.) generally have a similar action. According to Møllgaard, the sanocrysin introduced by him into practice, in a dilution of 1:1,000,000, inhibits the growth of tuberculosis bacillus cultures, and in a concentration of 1:100,000, kills them. Subsequent works confirmed these data only in relation to certain strains of bacilli. Spirochetes (Spirochaeta gallinarum) die only in a 1:200 solution. Therefore, many authors deny the possibility of a direct bactericidal action of the preparation during its therapeutic use. Many explain the positive results of Møllgaard's experiments on animals infected with tuberculosis bacilli by the fact that he used unusually weakly virulent laboratory strains of bacilli, where, apparently, a cure with sanocrysin is possible. In experimental syphilis of rabbits, the results were much better (a cure without relapses was observed). Many authors observed a clear therapeutic effect of sanocrysin in acute bacterial infection of animals (streptococci, febris recurrens, erysipelas, mouse typhoid, etc.). In humans, the indicated preparations (especially sanocrysin) were widely used for pulmonary tuberculosis, and with careful use in suitable cases (exudative forms not older than a year, of mild and moderate severity, less successfully in productive forms), favorable results were noted by some authors, especially in the first years of the practical application of these preparations in therapy; the same applies to tuberculosis of glands, peritoneum, and larynx, lupus, especially lupus erythematodes, psoriasis. Conversely, intestinal tuberculosis, cachectic states, diseases of the kidneys and liver, and insufficiency of the heart muscle are considered by the majority of authors to be a contraindication to the use of these agents. All authors emphasize the danger of outpatient treatment with sanocrysin. The study of the fate of gold preparations introduced into the body showed that gold disappears very quickly from the blood; upon analysis of organs, the most gold (calculated by organ weight) is found in the intestines and kidneys, less in the spleen and liver, and traces in the lungs and heart. Accumulation in tuberculous foci was not detected. Gold is excreted mainly by the kidneys and intestines over the course of several months (perhaps even longer). With careless administration of the preparations, unfavorable phenomena are observed (see above—acute gold poisoning). Of the focal reactions, the most dangerous are pneumonia, toxic myocarditis, and pulmonary edema. The theories of action boil down to the following. Møllgaard and some other authors believe that sanocrysin kills and dissolves tuberculosis bacilli; in this process, their endotoxins are released, which cause focal and general reactions similar to tuberculin shock. Therefore, Møllgaard proposed, to eliminate side effects, to administer calf serum immunized with tuberculosis bacilli or tuberculin simultaneously with sanocrysin. The majority of authors hold the view that complex gold compounds do not possess a bactericidal action but exert a direct effect on tissues (in particular, irritating the reticulo-endothelial apparatus), which favors the development of a cirrhotic process. The general reaction is the result of gold poisoning and, perhaps, the products of tissue decay caused by it (a negative nitrogen balance is often observed). The greater ease of occurrence of side effects in tuberculosis patients compared to healthy ones has a complete analogy with the phenomena during the use of nonspecific parenteral therapy. Any antitoxic action of Møllgaard's serum is denied by the majority of authors; they saw no benefit from its use. Gold preparations. 1. Aurum foliatum—the thinnest leaves, translucent with a bluish-green color; used for coating pills. 2. Aurum pulveratum—prepared in a special way, used in dental practice for filling teeth, and for crowns, bridges, and other prosthetic work—alloys of metallic gold. 3.

Gold chloride - two types of compounds are distinguished: a) Aurum chloratum acidum, s. flavum (HAuCl₄+4H₂O) - yellow-orange crystalline mass, easily deliquescing in air; contains 48% gold, easily soluble in water, ethanol, and ether; in medicine, it was formerly used as a cauterizing agent; b) Aurum chloratum neutrale, s. fuscum (AuCl₃+2H₂O) - brown, easily deliquescing mass, very easily soluble in water; the anhydrous compound contains 64.9% gold; used as a cauterizing agent (rarely) and as an antiseptic. Gold chloride is used in histological technique for the impregnation of fibrous structures (Belynovsky's method). 4. Auro-Natrium chloratum - yellow-orange crystalline powder, easily soluble in water with a neutral or slightly acidic reaction; the preparation, obtained by the method of the American Pharmacopeia, contains 30% gold, 35-37% NaCl, and 2-4% water. Locally, a 1-2:250 solution acts as a strong cauterizing agent; previously (mixed with talc and bolus) it was used for rubbing in cases of syphilitic lesions of the tongue and gums. Internally, it was given for syphilis, scrofula, and pulmonary tuberculosis at 0.003-0.006 three times a day or as a nervine (a 0.2:20.0 solution in water, 20 drops three times a day). 5. Natrium auri-chloratum (NaAuCl₄+2H₂O) - orange-yellow crystals, very easily soluble in water and alcohol, contains 49.5% gold; used like the previous mixture. 6. Aurum-Kalium cyanatum [2KAu(CN)₄+3H₂O] - colorless crystals, soluble in water and insoluble in alcohol; possesses a strong antiseptic effect. In 1913, it was proposed for the treatment of tuberculosis and syphilis (intravenously 0.02-0.05), it is very toxic, and is now almost never used. 7. Aurum tribromatum (AuBr₃) - dark brown mass, soluble in water, alcohol, and ether; internally for epilepsy (0.008 to 0.012 per day), for migraine attacks (0.003 twice a day, one hour before meals). 8. Auro-Kalium bromatum (KAuBr₄+2H₂O) - black-brown needle-like crystals, easily soluble in water; subcutaneously for epilepsy 0.02 per dose (in a 0.4:20.0 solution in water). 9. Aurum jodatum - internally against syphilis (0.005-0.01 per dose). 10. Aurum oxydatum [Au(OH)₃], or Acidum auricum - yellow-brown powder, insoluble in water, soluble in hydrochloric and concentrated nitric acids; formerly used against syphilis. 11. Aurum colloidale - used mainly intravenously (can also be intramuscularly): for example, for the first 2 days, 2 cm³ intramuscularly, on the 3rd day 0.5-1 cm³ intravenously, and then gradually increase to 2 cm³; when administered only intramuscularly, 4-6 cm³ are given repeatedly every 2 days until the temperature drops and the general condition improves; for the spinal canal, the doses are the same as intravenously; for children, it is given in enemas at 0.5-1 cm³ depending on age. 12. Aurocollargol (Heyden) - electro-colloidal solution of Au-Ag with a content of 0.006% Au and 0.06% Ag; injected intravenously (very slowly), initially 2-5 cm³, then gradually increasing the dose to 10-20 cm³ per dose; the disinfectant effect is much stronger than that of each metal individually. 13. Krysolgan [C₆H₄(NH₂)(SAu)COONa] - sodium salt of aminoauro-thiophenol-carboxylic acid, contains 50% gold; a greenish or gray-yellow amorphous powder, easily soluble in water, insoluble in alcohol and ether; decomposes rapidly in light. Used intravenously, preferably starting with small doses (0.1 mg); slowly increasing the dose, reaching 0.1 per day; intervals between injections are 10-20 days; administered in a freshly prepared 10 percent solution. 14. Triphal (C₆H₃N:NH.CS.Au.COONa+2H₂O) - sodium salt of auro-thio-benzimidazole-carboxylic acid; contains up to 44% gold; light yellow loose powder, easily soluble in water with a slightly alkaline reaction and in heated glycerin; insoluble in alcohol and ether. On sale in ampoules in dissolved form; initially, the solution released was very toxic, possibly due to poor glass in the ampoules. Administered intravenously (very slowly), starting with 0.5-1 mg, gradually increasing to 0.05 per day. Intervals between injections are 10-14 days. Compared to the previous one, it is much more stable and less toxic. 15. Solganal (C₇H₆O₄NS₃Na₂Au) - disodium salt of sulfomethylamino-auro-mercaptobenzenesulfonic acid (synonym - Sulfoxylat I); contains 36% gold; on sale in a 10% solution and in ampoules, the solution is yellow-brown in color, stable in the absence of air, sterilized at 100°. Intravenously, it is administered from 0.01, gradually increasing to 0.25-0.5 per day. Intervals between injections are 8-10 days. In addition to pulmonary tuberculosis, it has been used for streptococcal sepsis, multiple sclerosis, syphilis, and chronic infectious arthritis. According to some authors, it surpasses other gold preparations in its effect and is at least equal to the effect of Sanocrysin. 16. Sanocrysin (Na₃AuS₂O₃+3H₂O), or (according to Schnitzer) (S₂O₃Au)-Na-S₂O₃-auro-thiosulfate of sodium. According to Møllgaard, the structural formula is as follows: Au(S₂O₃)₂. Sanocrysin consists of white, easily soluble in water, but non-hygroscopic, crystalline needles. The aqueous solution of neutral reaction is stable for a long time when stored in the dark; stability in dry form is up to 1 year. The dry preparation contains 37.1-37.3% gold. It is used intravenously in a 5% solution in distilled and sterilized water. Recently, it has been insistently recommended to use small doses: starting with 0.01-0.05 and, slowly increasing, reaching 0.75-1.0 for men and 0.5-0.75 for women. The interval between injections is 2-6 days. The initial large doses of Danish authors have now been abandoned. The course of treatment is four or more months. The French preparation is called Thiochrysin (intravenous injections of 0.125-0.2 once a week; others advise smaller doses).