TAILIEUCHUNG - Chapter 017. Fever and Hyperthermia (Part 3)

Pathogenesis of Fever Pyrogens The term pyrogen is used to describe any substance that causes fever. Exogenous pyrogens are derived from outside the patient; most are microbial products, microbial toxins, or whole microorganisms. The classic example of an exogenous pyrogen is the lipopolysaccharide (endotoxin) produced by all gramnegative bacteria. Pyrogenic products of gram-positive organisms include the enterotoxins of Staphylococcus aureus and the group A and B streptococcal toxins, also called superantigens. One staphylococcal toxin of clinical importance is that associated with isolates of S. aureus from patients with toxic shock syndrome. These products of staphylococci and streptococci cause fever in. | Chapter 017. Fever and Hyperthermia Part 3 Pathogenesis of Fever Pyrogens The term pyrogen is used to describe any substance that causes fever. Exogenous pyrogens are derived from outside the patient most are microbial products microbial toxins or whole microorganisms. The classic example of an exogenous pyrogen is the lipopolysaccharide endotoxin produced by all gramnegative bacteria. Pyrogenic products of gram-positive organisms include the enterotoxins of Staphylococcus aureus and the group A and B streptococcal toxins also called superantigens. One staphylococcal toxin of clinical importance is that associated with isolates of S. aureus from patients with toxic shock syndrome. These products of staphylococci and streptococci cause fever in experimental animals when injected intravenously at concentrations of 1-10 pg kg. Endotoxin is a highly pyrogenic molecule in humans when injected intravenously into volunteers a dose of 2-3 ng kg produces fever leukocytosis acute-phase proteins and generalized symptoms of malaise. Pyrogenic Cytokines Cytokines are small proteins molecular mass 10 000-20 000 Da that regulate immune inflammatory and hematopoietic processes. For example the elevated leukocytosis seen in several infections with an absolute neutrophilia is the result of the cytokines interleukin IL 1 and IL-6. Some cytokines also cause fever formerly referred to as endogenous pyrogens they are now called pyrogenic cytokines. The pyrogenic cytokines include IL-1 IL-6 tumor necrosis factor TNF ciliary neurotropic factor CNTF and interferon IFN a. IL-18 a member of the IL-1 family does not appear to be a pyrogenic cytokine. Other pyrogenic cytokines probably exist. Each cytokine is encoded by a separate gene and each pyrogenic cytokine has been shown to cause fever in laboratory animals and in humans. When injected into humans IL-1 and TNF produce fever at low doses 10-100 ng kg in contrast for IL 6 a dose of 1-10 pg kg is required for fever production. A wide .

• Y học thường thức
• Fever and Hyperthermia
• bệnh học và điều trị
• bài giảng bệnh học
• tài liệu học ngành y
• Harrisons Internal Medicine
• BMC Cancer
• Psychogenic fever
• Small cell carcinoma
• Malignant tumors
• Acute stress induced hyperthermia
• Antidepression treatment
• chuyên ngành y khoa
• tài liệu y khoa
• lý thuyết y học
• giáo trình y học
• bài giảng y học
• bệnh lâm sàng
• chuẩn đoán bệnh
• medical books
• pharmacology
• epidemiologic
• Obstetrics
• anatomy
• Preventing Morbidity
• Multidisciplinary Care
• Harrisons principles of internal medicine
• Internal medicine
• Quality of health care
• Developed countries
• Health care systems
• Chest discomfort
• Clinical medicine
• The cardiovascular system
• Critical care medicine
• The kidney and urinary tract
• The gastrointestinal system
• The joints and adjacent tissues
• Neoplasms of the Lung
• bệnhbệnh học và điều trị
• Sodium and Water học và điều trị
• General considerations in clinical medicine
• Cardinal manifestations
• Presentation of diseases
• The environment and disease
• Regenerative medicine
• Introduction to clinical medicine
• The environment
• Disorders of the cardiovascular system
• Disorders of the respiratory system
• Disorders of the gastrointestinal system
• Infectious diseases
• The respiratory system
• Neurologic Disorders
• Moraxella Infections
• Haemophilus Infections
• Bệnh truyền nhiễm
• Tim mạch
• Tiết niệu
• Tiêu hóa
• Cơ xương khớp
• Acute rheumatic fever
• Antiphospholipid syndrome
• Inflammatory myopathies
• Relapsing polychondritis
• Pituitary tumor syndromes