Патологическая физиология теоретический курс = Pathological physiology theoretical course. Учебное пособие

starch is gradually added by stirring with 100 ml of boiling distilled water) and in the first 6 tubes add a drop of pus: 1 drop in the 1st test tube, 2 in the 2nd tube, etc. In the 7th test tube (control) instead of pus, 6 drops of blood serum should be poured, and in the 8th – 6 drops of physiological solution. Then in the first 5 tubes, level the volume of fluid with physiological solution.

Shake the tubes and place in a thermostat for 20 minutes. Then add to them one drop of Lugol solution (0.3g of crystalline iodine mixed with 2g of potassium iodide, grind slightly, add 300 ml of distilled water), shake the contents. By its color, it can be judged on the amylolytic activity of purulent exudate. The contents of the control tubes should be blue, which indicates the reaction of iodine with starch.

Scheme of the reaction

The absence of color in test tubes (usually 6th and 5th) indicates complete amylolysis. The amylolytic activity of the purulent exudate is expressed by the number of drops of pus required for complete cleavage of 1 ml of 0.25% starch solution for 20 minutes at 37° C.

4. The properties of different types of exudate and their characteristic features are studied by demonstration samples obtained experimentally or under clinical practice conditions.

51

Control questions

1. Features of metabolic disorders in the focus of inflamma-

tion.

2.Physico-chemical changes in the inflammatory focus, the causes and mechanisms of their development.

3.Physiologically active substances, their origin and significance in inflammation.

4.Classification of inflammation. Types of exudates, their characteristics.

T o p i c 1 3

FEVER. IT’S TYPES (written test)

Purpose of the lesson. To clarify the essence of the fever process and its typical features. Learn the method of graphical representation of various types of fever.

Tasks.

1.Draw a graph of the fever cycle, using the temperature sheets of five animals with various diseases.

2.Analyze the obtained temperature curves and give a detailed description of each febrile reaction, determine its degree, the features of the flow through the stages, type. To name the diseases for which this type of fever is typical, the causes and conditions determining its features.

Methodical instructions to performthe work

During the classes, each student receives 5 temperature sheets with digital data, according to which he must independently plot the temperature curves on millimetric paper. When applying all the curves to a single sheet of paper, it is better to use multi-colored pencils.

52

It is necessary to give a brief description of each temperature curve, determine the type of febrile cycle and record the results of their work (the species and name of the animal, the fever characteristics by degree, type and other features of the course of the disease under which it is observed, etc.) under the graph.

Written test work is handed over to the teacher for assessment. If there are errors, it is returned to the student. At the end of the lesson, a summary of the work done is summarized and marks are given.

Control questions

1.The concept of a fever, its general, characteristic.

2.Etiology of fever. Pyrogenic substances, their chemical nature and sources of formation in the infectious process, aseptic tissue damage and immune reactions.

3.Pathogenesis of fever. The role of the nervous and endocrine systems in the occurrence and development of fever.

4.Thermoregulation at different stages of the fever cycle.

5.Classification and types of feverish reactions.

6.Changes in physiological functions and metabolism in fe-

ver.

7.Biological significance of the febrile reaction.

T o p i c 1 4

HYDROCARBON EXCHANGE ABNORMALITIES. DIABETES AND HYPOGLYCEMIC COMA:

PATHOGENESIS, MAJOR MANIFESTATIONS

AND EXPERIMENTAL THERAPY

Purpose of the lesson. Experimentally study the causes, mechanism and the main signs of the damages of carbohydrate metabolism and other body functions, the ways of their correction in diabetes mellitus and hypoglycemic syndrome.

53

Tasks.

1.Find out whether the blood glucose in the animal is changing and how it is affected by a stress reaction.

2.Determine how the level of glucose and the general condition of the animal is affected by the administration (subcutaneously) of a relatively large dose of insulin into the body.

3.Identify the effect of glucose administration to an animal in a hypoglycemic coma.

4.Determine the nature, degree of damages of carbohydrate metabolism (changes in the concentration of glucose and ketone bodies in the blood and their quantity excreted in the urine) and other disorders in the animal's body under experimental diabetes.

Research Methodology

1. The reaction of stress in animals in the experiment can be caused by exposure to various harmful agents (trauma, cold, toxins, etc.). To model a stressful situation in the body, hormones are used – adrenaline, corticotropin, glucocorticoids, which are administered to animals in large (super-physiological) doses.

In rabbits, which were without food for 18-24 hours, take a micropipette of 0.1 ml of blood from the edge vein of the ear and determine the glucose level (baseline level) by the method described below. Subcutaneously or intravenously, inject an adrenaline solution at a dose of 0.4-0.5 mg per kg of animal weight. 30 minutes after injection of epinephrine, take a blood sample and determine the glucose content.

2-3. From the rabbit that was on an absolute diet for a day, but without water restriction, take a blood sample for glucose analysis, then inject subcutaneously or intravenously insulin at a rate of 4-5 IU per 1 kg of body weight. Than every 15-30 minutes take blood from the ear vein for testing and carefully monitor the condition of the animal. Keep the rabbit in a warm room during the period of the experiment.

54

After 1,5-3 h after insulin injection, the rabbit is in a state of hypoglycemic coma. To get acquainted with its clinical picture: determine the general condition of the animal, orientation, behavioral reflexes, reaction to various stimuli, muscle tone, disorders in coordination of movements, body temperature, cardiac activity and respiration, changes in glucose concentration in the blood. Then against the background of the development of shock phenomena intravenously or subcutaneously, 20% glucose solution at a rate of 1.0-1.5 ml per 1 kg of weight. After cessation of seizures and disappearance of other signs of hypoglycemia, again take blood to determine glucose.

4. Acute hypoinsulinism in animals in the experiment is achieved by complete surgical removal of the pancreas or by the introduction into the body of a chemical drug called alloxan, which selectively induces necrobiotic changes in the β-cells of the insular apparatus. As a result, there is a picture close to the clinic of diabetes.

One week prior to the study of the experimental animal (dog, rabbit, rat) on an empty stomach, inject intravenously or subcutaneously with a 5% solution of alloxan in physiological saline at the dose of 100-150 mg per 1 kg of body weight. During studies, study the clinical state of the experimental animal by comparing it with the control one. Take samples of blood and urine, determine in them the content of glucose and ketone bodies. Urine for research is usually taken by catheterization of the bladder. If urine can be collected during a certain period of time, then along with qualitative changes in its composition, it can be noted quantitative disorders of diuresis (polyuria, pollakizuria), characteristic of diabetes.

If the experiment is carried out in a rat, at the beginning of the session two rats (control and experimental) are injected subcutaneously with 20-30 ml of physiological saline solution heated (up to 36-37° C). After this, the animals are placed in funnels, and the urine is collected into graduated cylinders.

55

Determination of glucose in blood and urine by color reaction with orthotoluidine (Gultman method)

All blood samples obtained during the experiments are more convenient to process and examine for glucose simultaneously. Therefore, every blood sample after taking should be stabilized by adding an anticoagulant (heparin, sodium citrate, 10% sodium EDTA solution) and placed in the refrigerator until the end of the experiment.

Add 0.1 ml of blood to the centrifuge tubes with a micropipette, add 0.9 ml of a 3% solution of trichloroacetic acid to precipitate the proteins. The contents of the tubes should be thoroughly mixed and centrifuged for 2-3 minutes. Then 0.5 ml of transparent centrifuge is transferred to high thin-walled tubes and 2.0 ml of stabilized 6% solution of orthotoluidine in acetic acid is added.

When determining glucose in urine in high-thin-walled tubes, take 0.1 ml of urine (always clear, turbid urine or with a protein impurity treat as blood) and add 2.4 ml of orthotoluidine reagent.

Test tubes should be vigorously shaken several times and, covering the holes with aluminum foil, place for 8 minutes in a boiling water bath. The contents of the tubes quickly cool under a stream of cold water to room temperature. In parallel with the experimental samples, a standard sample containing 100 mg% glucose (a series of samples from 50 to 300 mg%) can be treated.

During the heating, the reaction of the glucose contained in the samples with the orthotoluidine reagent takes place. The solution acquires a greenish-blue color, the intensity of which is proportional to the concentration of glucose. It is determined on a photoelectron colorimeter at a wavelength of 630 nm (red light filter No. 9 FEK-56M) in cuvettes with a working distance of 5 mm.

The amount of glucose in the blood and urine is calculated by the formula

56

X EopEst 100 ? мг%?

Where Eop is the optical density of the test sample; Est is the optical density of the standard sample.

Detection of ketone bodies in urine (Lange assay)

To 3-5 ml of the tested urine, add 1 ml of glacial acetic acid and 0.5-1 ml of a freshly prepared 5% solution of sodium nitroprusside. Stir and then pour 2-3 ml of concentrated (25%) ammonia solution from the pipette. In the presence of acetone bodies in the urine, a pink-violet ring forms at the boundary of two media in 3 minutes.

Control questions

1.The importance of neuroendocrine mechanisms in the violation of carbohydrate metabolism.

2.Quantitative changes in blood glucose.

3.Hyperglycemia, its classification, causes and mechanism of development.

4.Pathogenesis and the main signs of diabetes mellitus.

5.Disorders of carbohydrate metabolism in diabetes mellitus. Factors causing the development of hyperglycemia and glucosuria.

6.Disorders of fat, protein and water metabolism, the mechanism of their origin and importance in diabetes mellitus.

7.Hypoglycemia. Etiology, pathogenesis and the main manifestations of hypoglycemic syndrome in farm animals.

8.Mechanism of development and clinical picture of hypoglycemic coma.

57

T o p i c 1 5

EDEMA, CAUSES AND MECHANISMS

OF ITS DEVELOPMENT. TOXIC PULMONARY EDEMA

Purpose of the lesson. On the example of toxic pulmonary edema, to study the causes, the main pathogenetic mechanisms and the role of the nervous system in the development of edema.

Tasks.

1.Find out what pathological changes in the lungs, disorders in breathing and life activity of the organism occur when the animal is poisoned with ammonium chloride.

2.Determine the dependence of the development of pulmonary edema caused by acute intoxication of the organism, from the functional state of the nervous system.

Research Methodology

To solve the tasks set, carry out the experiment on three rats, previously weighed (it is desirable that the mass of animals was the same). First determine the initial state and behavior of animals, focusing on the rhythm and amplitude of respiratory movements. Then, one of the rats is injected subcutaneously or intraperitoneally with a 10% urethane solution (1 ml per 100 g of weight) or 5% hexenal solution (0.3 ml per 100 g of weight). After the onset of deep anesthesia, in which the functions of the nervous system and the reactivity of the organism are depressed (20-30 minutes after the injection of the drug), two rats are simultaneously administered intraperitoneally with a 6% solution of ammonium chloride at a rate of 0.7 ml per 100 g of animal mass. The third (control) rat is given the same amount of saline.

During the experiment, observe the general state and behavior of animals. Pay special attention to a breathing disorder, counting every 5-10 minutes the number of respiratory movements per minute. If, 40-50 minutes after the introduction of am-

58

monium chloride, the animals do not die, all the rats are killed by electric shock or decapitation. Open the chest, extrude the lungs, after a thorough examination and description of their appearance, weighed on the chemist's scales, calculate the pulmonary somatic ratio (the ratio of the weight of the lungs to the total mass of the animal).

Based on a comparative analysis of the results of examination and weighing of the experimental and control rats, a conclusion is drawn on the 1st and 2nd tasks.

Control questions

1.The importance of nervous and humoral factors in the regulation of water metabolism.

2.The concept of edema and dropsy.

3.Causes and mechanisms of edema development, their classification.

4.Pulmonary edema and its pathogenesis.

APPENDIX

TASKS FOR SELF-TRAINING, KNOWLEDGE CONTROL

AND TASKSIN PATHOPHYSIOLOGY

(by S.I. Liutinskiy, V.S. Stepin, 2001)

TOPIC 1.

GENERAL NOSOLOGY

Self-training and knowledge control tasks

1. Concept of the disease. 2. The idea of the disease at different historical stages of the development of veterinary

59

medicine. 3. Contribution of Russian scientists (S.P. Botkin, I.M. Sechenov, V.V. Pashutin, I.I.Mechnikov, I.P. Pavlov, N.N. Sirotinin etc.) in the development of the materialist doctrine of disease. 4. Criticism of idealistic, metaphysical, antiscientific ideas about the disease. 5. The main stages of the disease. 6. The idea of clinical and biological death. Signs of death. 7. General principles of diseaseclassification. 8. Hereditary and congenital diseases. 9. Remission of the disease, relapse, exacerbation, complication of the disease. 10. General principles of the prevention of diseases of farm animals.

Tasks

1.During the infection of erysipelas (acute stage), the pig developed a complication in the form of endocarditis. There was a deformation of the two-leaf valve. How should one treat this pathology in an animal as a pathological process or a pathological condition?

2.The diseased cow showed the following signs: poor appetite, decreased milk production, the animal more lies, rectal temperature 40.3º C, respiration 29 respiratory movements per minute, heart rate 86 in 1 min. To what period of the disease should be attributed a similar state of the animal, what is it characterized by?

3.The dog was ill for a long time with serous-fibrinous pleurisy. After resorption of exudate and the onset of clinical well-being, the owner asks: has the animal recovered? What should you say to owner?

4.As a result of squeezing the trachea, the animal took a lateral position, breathing ceased, blood pressure fell, and the heart stopped functioning. From the moment of asphyxiation, 4 minutes have passed. What was the death: biological or clinical? What is resuscitation, and what activities are included?

5.The dog surgically removed a breast cancer. But after 8 months there were new foci of blastomatous growth. How should this outcome be determined?

60