RU2591982C1 - Preservative for anatomic preparations - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine and can be used in making macroscopic preparations and corpse embalming. Preserving anatomical preparations for fixing biological tissues is 1-10 % aqueous solution of sodium benzoate.

EFFECT: invention allows to improve quality, information value and appearance of the anatomic preparations.

1 cl, 2 ex

Description

The invention relates to medicine, mainly to normal and pathological anatomy, zoology, embryology and can be used in the manufacture of macroscopic preparations for scientific and educational purposes, as well as for embalming corpses.

The main difficulties in studying biological objects are associated with their fragility, due to the post-mortem decomposition of organic tissues. Decomposition is a natural process of disorganization of biological tissues, due to two processes: autolysis and decay. Autolysis is significant in the early stages of decomposition and is due to the action of their own lytic cell enzymes. The term "rot" means the destruction of organics under the action of enzymes of various microorganisms.

There are many methods of preserving biological material based on the use of various physical (drying, freezing) and chemical factors (preservatives). In addition, methods of fixing biological tissues and methods of embalming corpses are separately distinguished. Fixation is the treatment of biological tissues with substances that prevent decay, preserving shape, structure, color and providing long-term storage in special fixing solutions; the term applies to both macro- and micropreparations. Embalming is the treatment of human and animal corpses with substances that prevent decay, preserving shape, color, preventing drying of tissues, changing their color and providing long-term storage of corpses in contact with the environment without further processing; the term applies only to a corpse or macro product.

In modern anatomical practice, various methods of processing the drug, involving the use of preservatives, are used to overcome this obstacle. All preservatives by the mechanism of action can be divided into two groups: disinfectants, which are based on the denaturation of proteins and toxic effects on microbial cells, and plastinizing agents, which create a coherent dispersed medium in the preparation. The first group consists of compounds such as formaldehyde (formalin), phenol, thymol, lysol, ethanol, methanol, arsenic acid, acetic acid, mercury salts, chromic acid, potassium dichromate. From the second group should be called epoxies, silicone, rubber. There are also funds that occupy an intermediate position and are capable of both fixing the drug like antiseptics and polymerizing in its tissues (Vasiliev O.D., Svetlov D.A., Ryabinin I.A. Polyhexamethylene guanidine - a new preservative for anatomical embalming // Issues of morphology XXI century. - 2008. - Issue 1. - P. 78-82). In connection with the high cost and recent term of the discovery of the plastination method, compounds of the first group are most often used.

Most often in practice, as a preservative, formalin-containing preservative solutions are used (Borzyak E.I., Usovich A.K., Borzyak I.E., Tuzova S.Yu., Romashev Α.Α., Chereminsky V.Yu. Technique the manufacture of anatomical preparations. - Vitebsk: Voronezh State Medical University, 2010. - P. 26). However, this preservative has many disadvantages. Firstly, under the influence of formalin, the consistency and size of the drug change: formaldehyde denatures proteins and dehydrates tissues, which leads to their compaction and contraction, as a result of which they lose elasticity, quickly dry and mummify. Secondly, formalin changes the color of the drug: as a result of the oxidation of hemoglobin and its transformation into methemoglobin, the tissues acquire a brownish-gray hue. To preserve the color and volume of the drug, additional reagents have to be used, which complicates the technique and requires additional financial costs. In addition, formalin weakly inhibits the activity of molds, which reduces the shelf life of drugs and leads to the need for restoration. Formalin solutions are not stable during storage - the concentration gradually decreases with insufficiently sealed containers due to the volatility of formaldehyde, and also become cloudy due to the precipitation of a white precipitate of paraformaldehyde. In the manufacture and subsequent use of the anatomical preparation, contact with formalin is inevitable. Meanwhile, formaldehyde is a toxic substance, exhibits teratogenic, mutagenic and carcinogenic properties. Especially unfavorable is the effect on the upper respiratory tract and cornea of the eye, due to locally irritating and cytotoxic effects.

All these shortcomings are deprived of drugs made using plastination. However, this method is complex, requires special expensive equipment and reagents, which prevents its mass use. In addition, this method does not exclude the preliminary fixation of the drug with formalin.

As an alternative to formalin-containing preservative solutions, an aqueous solution of dialkyl ketone peroxides is proposed - Complucad (Kuznetsov L.E., Khokhlov V.V., Fadeev S.P., Shigeev V.B. Embalming and restoration of corpses. - Smolensk-Moscow: NPO Profizdat, 1999 . - S. 121-124). It is slightly toxic and at the same time provides high-quality fixation of anatomical preparations. The disadvantages of using this solution, excluding its free and ubiquitous use, include its high cost, the need for imports due to the preservation of the secrecy of the composition and the associated difficulties of acquisition.

The closest analogue of the proposed preservative is an aqueous solution of ethyl acetate, benzoic acid, zinc chloride and ethylene glycol (Kolesnik L.L., Kharibova E.A., Nechay V.V. Preserving liquid for biological objects. // RF patent for the invention No. 2367155 Published on September 20, 2009). This preservative fluid is selected as a prototype.

However, ethylene glycol, used in this fluid as an anti-dehydration agent, is toxic (LD ₅₀ for rats - 4700 mg / kg), as well as volatile - its vapors irritate the mucous membranes of the eyes and respiratory tract. Particularly dangerous is prolonged, chronic contact with ethylene glycol vapors. Another component of this preservative liquid - ethyl acetate - is even more toxic (LD ₅₀ for rats - 1160 mg / kg) and also volatile - its pairs have a locally irritating effect on the mucous membranes of the eyes and respiratory tract. In addition, ethyl acetate in contact with unprotected skin can cause dermatitis. Thus, the composition of this preservative fluid includes toxic and volatile compounds. The disadvantages of this preservative fluid also include the complexity and multicomponent composition.

The invention is aimed at improving the quality, increasing the information content and aesthetics of anatomical preparations by preventing changes in their natural color, consistency and size, increasing the service life and eliminating occupational hazards of the staff of anatomical and pathological laboratories due to the use of toxic preservative mixtures, carried out by replacing the preservative used for the manufacture and storage of anatomical and pathoanatomical macrodrugs in. Also the objectives of the invention include replacing the import of preserving fluids, simplifying and cheapening the process of preserving biological objects. This is achieved by using an aqueous solution of sodium benzoate as an anatomical preparation.

For this, anatomical preparations are washed from the blood in running water, placed for fixation in a 1-10% solution of sodium benzoate, the volume of which is 10 times the volume of the fixed organ. It is necessary to withstand the drug in solution until the concentration of preservative in its tissues reaches at least 1%. Large preparations and corpses can be preserved by injection of the solution into the blood vessels, followed by immersion of the drug in a similar solution. The concentration of sodium benzoate 1-10% in the solution is optimal, since with sufficient fixing activity of the solution, high safety for personnel working with it remains. When using a solution of a lower concentration (less than 1% sodium benzoate), a sufficient fixing ability of a preservative is not achieved, as a result of which bacterial decomposition continues in the tissues of the drug. The use of a solution of a higher concentration is also impractical, since it leads to the appearance of a locally irritating action of the solution and is not economically feasible. The fact that the volume of the preservative solution must exceed the volume of the organ is 10 times established experimentally. Changing this ratio downward (i.e., will be less than 10 times) leads to a deterioration in fixation. The increase is not economically justified.

Sodium benzoate is a sodium salt of benzoic acid. It is an odorless white powder, the taste of which, depending on the individual characteristics of the taste buds, may appear sweet, sour, bitter, or tasteless; easily soluble in water, more difficult in alcohol. Molar mass of 144.11 g / mol; melting point 410 ° C. It has a pronounced antimicrobial and fungicidal activity. It is used as a preservative in the food industry (E211) and as an expectorant in medicine. Does not cause gross denaturation of proteins, leading to a change in the consistency and volume of tissues. Low toxicity: LD ₅₀ when administered orally for rats - 4980 mg / kg. Sodium benzoate solutions are non-volatile, do not form vapors, are chemically resistant, do not have toxic and irritating effects on the upper respiratory tract and skin. Approved for use as a food additive E211 in Europe and the CIS. It is used as a preservative in the production of soft drinks and canned fish or canned food, as well as to increase the shelf life of sauces, fruit and vegetable products, sausages, cheeses, confectionery products and the processing of packaging materials for food products.

Examples

The essence of the invention is illustrated by the examples discussed below.

For experimental verification of the proposed substance, a 1% sodium benzoate solution was prepared in which fixed anatomical macro preparations (heart, human kidney) were placed. The survey was carried out at different times.

Example No. 1.

The biological object - the heart of an adult, weighing 280 g, was processed according to the proposed method: fixation was made by immersion in a 10-fold volume of a 1% aqueous solution of sodium benzoate. The duration of fixation is 7 days. The following results were obtained: the color of the object — little changed, the consistency — elastic, the volume and mass — were completely preserved.

Example No. 2.

The biological object is an adult kidney, weighing 160 g, subjected to processing by the proposed method: fixation is made by immersion in a 10-fold volume of 1% sodium benzoate solution. The duration of fixation is 5 days. The following results were obtained: the color of the object is slightly changed, the consistency is elastic, the volume and mass are completely preserved, which meets practical requirements.

Anatomical preparations fixed with a 1% sodium benzoate solution have a close to natural color, do not decrease in volume, retain their natural consistency (elastic and elastic), and are stored for a long time in an aqueous solution of sodium benzoate.

When preserving the claimed method, there is a slight change in the natural color of the organ both on the outer surface and in the section. No progressive discoloration is observed.

Thus, the claimed preservative slightly changes the color of the body.

To assess changes in the consistency and size of anatomical preparations, the volume and mass of anatomical preparations before and after the claimed method were measured.

When preserving the preparations according to the claimed method, the initial indicators of volume and mass did not significantly change. Therefore, the claimed preservative does not change the consistency and size of the anatomical preparations.

When studying the safety of drugs canned according to the claimed method, it was found that in drugs fixed with a solution of the declared preservative, there are no signs of development of saprophytic microflora within 2-3 years.

An important factor in occupational hazards for employees of anatomical and pathological laboratories is preservative liquids, which include toxic and volatile compounds with a pronounced local irritant and toxic effect. Long-term contact with their pairs leads to a decrease in mucociliary clearance due to the death of ciliated epithelial cells of the respiratory tract and a decrease in the production of surfactant, which contributes to the development and chronicity of the infectious pathology of the upper respiratory tract. Solutions of sodium benzoate do not have an irritating effect on the mucous membrane of the respiratory tract, not volatile, as a result of which they do not cause damage to the respiratory system. This preservative is low toxic, as a result of which even with prolonged contact with the proposed solution, situations accompanied by undesirable consequences for human health are practically eliminated. It has a relatively low cost and is produced in sufficient quantities on the territory of the Russian Federation.

Claims (1)

A preservative for anatomical preparations based on a disinfectant, characterized in that a 1-10% aqueous solution of sodium benzoate is used as a preservative for anatomical preparations.