Cicuta

Cicuta (Cicuta), water hemlock, a plant of the umbellifer family (Umbelliferae), found in several varieties; the main species is Cicuta virosa - poisonous water hemlock. It is distributed in Northern Europe and in our country in marshy areas, along the banks of rivers, ponds and lakes. In appearance, it bears considerable resemblance to parsley and spotted hemlock, which is why the ancients also called Cicuta Conium (Pliny). The most characteristic part of Cicuta is its tuberous rhizome, of cylindrical and ovoid shape; when the rhizome is cut in half from top to bottom, about ten irregularly quadrangular cavities, arranged horizontally one above the other, are revealed. In fresh rhizomes, an intensely yellow-colored juice exudes from the cut juice canals, which, according to Böhm (Bohm), contains a very poisonous resinous bitter substance - cicutoxin - an amorphous mass that reacts to acids, has a weak odor, is readily soluble in alcohol, ether and chloroform, sufficiently soluble in hot water and insoluble in petroleum ether; cicutoxin melts at t°+20°, rapidly decomposes when stored in air or when heated above 50°; in alcoholic solution it rapidly decomposes. Cicutoxin is present in all parts of the plant, as a result of which cases of poisoning of horses, cows and other animals have been observed when eating it. To poison an adult person, only one rhizome of Cicuta is sufficient. Cicutoxin strongly affects the central nervous system and is very similar in action to picrotoxin, but is inferior to the latter in strength of action. Cicutoxin is excreted in urine and milk. Symptoms of poisoning: colic, sometimes vomiting, diarrhea, dizziness, general weakness, fainting state with loss of consciousness, very strong convulsions accompanied by respiratory arrest, dilation of pupils, grinding of teeth, foamy saliva, slow and difficult breathing, cyanosis, cold sweat, rare pulse. Death occurs from paralysis of the respiratory hours 10-14 after the onset of poisoning with Cicuta, sometimes the poisoning drags on and the poisoned die after 1-3 days. Assistance to those poisoned by Cicuta consists of emptying the stomach and intestines and usual symptomatic measures. Artificial resuscitation is necessary if cyanosis occurs. Since cicutoxin is difficult to dissolve in water and is relatively slowly absorbed, it is advisable to try as an antidote the administration of large amounts of activated charcoal and also paraldehyde internally to weaken the effect of cicutoxin on the respiratory center. In autopsies of those poisoned by Cicuta, signs of inflammation in the stomach and intestines and signs of death by suffocation are observed. It is impossible to chemically prove the presence of cicutoxin in the body of the poisoned; one has to resort to biological testing on frogs, in which inflation of the lungs, cries and arrest of the heart in diastole, which ceases immediately after cutting both vagus nerves, are indicative. Cicuta has no medicinal use. ZIEHL-NEELSEN METHOD of staining (Ziehl, Neelsen) tubercle bacilli is the most widespread at present throughout the world. Since the discovery of the tubercle bacillus, it has been known that this bacillus is not stained by ordinary alcohol-water solutions of aniline dyes. To stain the tubercle bacillus, the dye must contain a mordant that would prepare the bacillus in advance, making it accessible to the dye solution. R. Koch, and later Ehrlich, used aniline as a mordant. Aniline is a very unstable substance and did not give consistent results. In 1882, Ziehl proposed carbolic acid instead of aniline, which proved extremely suitable for this purpose. Ziehl used for staining tubercle bacilli a 2% solution of methyl violet in a saturated aqueous solution of carbolic acid. In this solution, the preparation was stained for one hour, after which it was washed with water and decolorized in nitric acid. In 1884, Neelsen simplified and significantly accelerated the staining of tubercle bacilli, leaving only carbolic acid from Ziehl's method. Instead of the methyl violet proposed by Ziehl, Neelsen began to use fuchsin. The fuchsin solution proposed by Neelsen had the following composition: basic fuchsin - 1 g; 5% carbolic acid - 100 cm⁵; 96% alcohol - 10 cm³. To speed up the process, Neelsen recommends heating the preparation in the dye solution until steam appears. Histological preparations (sections) should be stained for 10-15 minutes at room temperature. After staining with fuchsin, Neelsen decolorized the preparation with 25% sulfuric acid, washed it with water and restained with an aqueous solution of methylene blue for 1-2 minutes. This method is called the Z-N method. This staining is extremely good in brightness and contrast with the background - the red tubercle bacillus on a blue background. The combination is extremely pleasant and convenient for the eye. In most of the methods subsequently proposed for staining tubercle bacilli, the mordant substances and the decolorizing substances were changed, but fuchsin remained in most modifications. All methods proposed to date for staining tubercle bacilli have no advantages over the described method. Over time, a number of modifications were proposed, for example, before adding alcohol and carbolic solution, rub fuchsin with a few drops of glycerin; for decolorization, use not an aqueous solution of acid, but a 3% hydrochloric acid alcohol (Günther) in order to be able to confirm during staining that the bacillus found is not only acid-fast but also alcohol-resistant - a sign necessary for the tubercle bacillus; Gabbet proposed to combine decolorization and additional staining into one act for faster staining, etc. E. Nolitova.