I. Active Vocabulary.

unprecedented – безпрецедентний;

incapacitation - втрата працездатності;

appreciable – істотний, відчутний, помітний;

fitness - стан здоров'я, придатність;

boil – опік;

wound – рана;

liable – відповідальний, схильний, підвладний;

to bind - зв'язувати;

vial - пробірка, ампула.

II. Read and translate the text.

ANTIBIOTICS

Antibiotics probably represent the greatest single contribution of drug therapy in the past half-century, a period characterized by unprecedented advancements in health care. This group of drugs provides effective control of many human microbial pathogens that previously caused prolonged incapacitation or death without appreciable regard for age, economic status, or physical fitness.

The word "antibiotic" is derived from the term antibiosis, which literally means "against life" (anti — against, bios — life). The most widely accepted concept defines an antibiotic as a chemical substance produced by a micro­organism that has the capacity, in low concentration, to inhibit selectively or even to destroy bacteria and other microorganisms through an antimetabolic mechanism. Essentially all definitions limit antibiotics to biologic constituents that exert their action in low concentrations. This definition excludes microbial metabolites, such as ethanol, that are active against protoplasmic functions at higher concentrations.

The history and development of antibiotic agents are similar to the patterns noted for other types of drugs. Relatively ineffective attempts to use materials that are now recognized as having antibiotic association can be detected in folk medicine and in prepenicilline scientific literature. The study of antibiotics began in 1929, when A. Fleming proved that the filtrate of a broth culture of the fungus Penicillium notation has antibacterial properties in relation to gram-positive micro-organisms. In 1940 E. Chain and H. Florey obtained a relatively stable preparation of penicillin. Development in the antibiotic field since 1940 is characterized by a practical blending of empiric observation and increasingly sophisticated manipulations of biologic and chemical factors. This familiar pattern is frequently overlooked because an aura of the 20-th century miracle drugs has surrounded the antibiotics.

Reports, some dating back 2500 years, indicate that various ancient and primitive peoples applied moldy bread, soybean curds, and other materials to boils and wounds liable to infection; this can be considered a folk medicine type of antibiotic therapy. Pasteur demonstrated bacterial antagonism shortly after he established the bacterial etiology of infectious disease. Initially, antibiotic therapy was commonly employed in a wide range of microbial infections with only limited logic or design.

The commercialy available and therapeutically useful antibiotics can be classified on the basis of the biosynthetic origin of the antibiotic molecules. Antibiotics derived from amino acids include the penicillins, the cephalosporins, chloramphenicol, cycloserine, dactinomycine, and the polypeptide antibiotics (e.g.— bacitracin, polymyxin).

Antibiotics derived from acetate metabolism include tetracyclines (a group of actinomycete antibiotics that have a broad spectrum and considerable therapeutic utility), macrolide antibiotics, polyenes, etc.

According to the character of action aafffiiotics are subdivided into bacteriostatic (tetracyclines, chloramphenicol and others) and bactericidal (penici I line, ristomycin, etc).

The mechanism of action of antibiotics varies. For example, penicilline inhibits the synthesis of polymers of the bacterial cell wall and streptomycin inhibits the incorporation of some amino acids in protein synthesis. Chloramphenicol is a specific inhibitor of the biosynthesis of bacterial protein. Tetracyclines, lincomycin, erythromycin, kanamycin, neomycin, spectinomycin, sparsomycin and others belong to the group of antibiotics which inhibit protein biosynthesis in bacteria at the ribosome level. So there are various hypotheses and theories which have not entirely revealed the mechanism of action, and this question has not been completely solved.

III. Answer the questions.

1. How can you define antibiotics?

2. What do antibiotics provide?

3. What do all definitions limit antibiotics to?

4. What do you know about the history and development of antibiotics?

5. When did the study of antibiotics begin?

6. What is development in the antibiotic field since 1940 characterized by?

7. What can be considered a folk medicine type of antibiotic therapy?

8. Where was antibiotic therapy commonly employed initially?

9. How can commercially available and therapeutically useful antibiotics be classified?

10. What do antibiotics derived from amino acid? include?

11. What are tetracyclines, macrolide antibiotics and polyenes derived from?

12. What two groups are anti­biotics subdivided into according to the character of action? Give examples of each group.

13. What do you know about the mechanism of action of antibiotics?

IV. Доповніть речення інформацією з тексту

1. Antibiotics provide effective control of many human microbial pathogens....

2. Antibiotic is a chemical substance that has capacity to....

3. The history and development of antibiotic agents are....

4. Develop-, ment in the antibiotic field is characterized by....

5. Various ancient and primitive peoples applied....

6. The commercially available and therapeutically useful antibiotics can be classified....

7. Antibiotics derived from acetate metabolism include....

8. According to the character of action antibiotics are....

V. Vocabulary.

to adjust – пристосовувати;

to ground – подрібнювати;

even – рівний, однаковий;

to damp – змочувати, зволожувати;

to transfer – перемішати, переносити;

to drip – капати, крапати;

to macerate – вимочувати (лікарську сировину);

to conform – узгоджувати, погоджувати; відповідати;

to agitate – перемішувати;

to comminute – дробити, тонко здрібнити.

VI. Read and translate the text.

TINCTURES

Tinctures are alcoholic or hydroalcoholic solutions'prepared fiom vegetable materials or from chemical substances.

The portion of drug represented in the different chemical tinctures is not uniform but varies according to the estab- lished standards for each. Traditionally, tinctures of potent vegetable drugs essentially represent the activity of 10 g of the drug in each 100-ml of tincture, the potency being adjusted by the following assay. Most other vegetable tinctures represent 20 g of the respective vegetable material in each 100 ml of tincture.

The general processes to be employed for manufacture of tinctures, unless otherwise directed in the individual monographs, are as follows: Process P — Carefully mix the ground drug or mixture of drugs with a sufficient quantity of the prescribed solvent or solvent mixture to render it evenly and distinctly damp, allow it to stand for 15 min, transfer it to a suitable percolator, and pack the drug firmly. Pour on enough of the prescribed solvent or solvent mixture to saturate the drug, cover the top of the percolator and, when the liquid is about to drip from the percolator, close the lower orifice, and allow the drug to macerate for 24 hours or for the time specified in the monograph. If no assay is directed, allow the percolation to proceed slowly, or at the specified rate, gradually adding sufficient solvent or solvent mixture to produce 1000 ml of tincture, and mix. If an assay is directed, collect only 950 ml of percolate, mix this, and assay a portion of it as directed. Dilute the reminder with such quantity of the prescribed solvent or solvent mixture to produce a tincture that conforms to the prescribed standard, and mix.

Process M — Macerate the drug with 750 ml of the prescribed solvent or solvent mixture in a container that can be closed, and put in a warm place. Agitate it frequently during 3 days or until the soluble matter is dissolved. Transfer the mixture to a filter, and when most of the liquid has drained away, wash the residue on the filter with a sufficient quantity of the prescribed solvent or solvent mixture, combining filtrates, to produce 1000 ml of tincture, and mix.

Tinctures require storage in tight, light-resistant containers, away from direct sunlight and excessive heat.

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