15. Secondary amyloidosis: causes, chemical structure of amyloid, mechanisms of development, examples of diseases. Macro- and microscopic changes, outcomes, clinical significance.

AA (secondary, hereditary)

Whey A protein (1-globulin)

Rheumatoid arthritis Chronic infections (tuberculosis, leprosy, bronchiectasis, chronic osteomyelitis) Hodgkin's disease Inflammatory diseases of the bladder Family Mediterranean Fever

Liver, kidneys, spleen

Secondary amyloidosis develops as a complication of chronic infectious and inflammatory diseases (for example, tuberculosis), malignant tumors (for example, lymphomas) and diffuse connective tissue diseases (primarily rheumatoid arthritis).

Macro- and microscopic characteristics of amyloidosis. The appearance of organs in amyloidosis depends on the degree of the process. If the deposits of amyloid are small, the appearance of the organ is little changed, and amyloidosis is detected only by microscopic examination. With severe amyloidosis, the organ is enlarged, becomes very dense and brittle, and has a peculiar waxy or greasy appearance on the incision.

Outcome: depends on the underlying disease, but as a rule, amyloidosis is unfavorable, almost irreversible.

16. General obesity: definition, classification, causes. Macro- and microscopic changes in organs, related diseases and complications.

Stromal vascular fatty dystrophy - lipidosis, occurs when the metabolism of neutral fats or cholesterol and its esters is disrupted. Obesity, or obesity, is an increase in the volume of neutral fat in fat depots, which has a general character. It is expressed in the abundant deposition of fat in the subcutaneous tissue, omentum, mesentery, mediastinum, epicardium. Adipose tissue appears where it is usually absent or only present in small amounts, for example in the stroma of the myocardium, the pancreas.

Classification: According to the etiological principle, primary and secondary obesity are distinguished. The cause of primary obesity is unknown, so it is called idiopathic.

Types of secondary obesity:

• alimentary obesity, the causes of which are unbalanced nutrition and physical inactivity;

• cerebral obesity develops with trauma, brain tumors, and a number of neurotrap infections;

• endocrine obesity- Froelich and Itsenko-Cushing syndromes, adiposogenital dystrophy, hypogonadism, hypothyroidism;

• hereditary obesity- Lawrence-Moon-Bidl syndrome and Gierke's disease.

According to external manifestations, symmetrical (universal), upper, middle and lower types of obesity are distinguished.

• With a symmetrical type, fat is deposited relatively evenly in different parts of the body;

• The upper type is the accumulation of fat mainly in the subcutaneous tissue of the face, occiput, neck, upper shoulder girdle, mammary glands;

• With the average type, fat is deposited in the subcutaneous tissue of the abdomen in the form of an apron;

• In the lower type - in the hips and shins.

According to the excess body weight of the patient, several degrees of obesity are distinguished.

• In case of grade I obesity, the excess body weight is 20-29%,

• At II - 30-49%,

• At III - 50-99%

• At IV- up to 100% or more.

Morphological changes: In the hypertrophic variant, fat cells are enlarged and contain several times more triglycerides than usual, while the number of adiposocytes does not change. Adiposocytes are not sensitive to insulin, but they are highly sensitive to lyric hormones. The course of the disease is malignant.

In the hyperplastic variant, the number of adiposocytes is increased, the number of fat cells reaches a maximum in the puberty period and does not change further. However, the function of adiposocytes is not impaired, their metabolic changes are absent, and the course of the disease is benign.

Heart obesity: Heart obesity in obesity is of great clinical importance. Adipose tissue, growing under the epicardium, envelops the heart like a case. It is embedded in the myocardial stroma, especially in the subepicardial regions, which leads to atrophy of muscle cells. Obesity is usually more pronounced in the right half of the heart. Sometimes the entire thickness of the myocardium of the right ventricle is replaced by adipose tissue, and therefore a heart rupture may occur.