NEET MDS Synopsis
Cell Functions
General Microbiology
Cell Functions:
-> Autolysis
- degradative reactions in cells caused by indigenous intracellular enzymes – usually occurs after cell death
- Irreversible (along with Coagulative necrosis or infarcts) – reversible: fatty degeneration, & hydropic degeneration
-> Autolysin:
• Ab causing cellular lysis in the presence of complement
• Autolytic enzymes produced by the organism degrade the cell’s own cell wall structures
-> In the presence of cephalosporins & penicillins, growing bacterial cells lyse
• W/o functional cell wall structures, the bacterial cell bursts
-> Heterolysis: cellular degradation by enzymes derived from sources extrinsic to the cell (e.g., bacteria)
-> Necrosis: sum of intracellular degradative reactions occurring after individual cell death w/in a living organism
Alcoholic cirrhosis
General Pathology
Alcoholic (nutritional, Laennec’s) cirrhosis
Pathology
Liver is at first enlarged (fatty change), then return to normal size and lastly, it becomes slightly reduced in size (1.2 kg or more).
- Cirrhosis is micronodular then macronodular then mixed.
M/E
Hepatocytes:- show fatty change that decreases progressively. Few hepatocytes show increased intracytoplasmic haemochromatosis.
b. Fibrous septa:- Regular margins between it and regenerating nodules.
-Moderate lymphocytic infiltrate.
– Slight bile ductular proliferation.
Prognosis:- It Progresses slowly over few years.
Management of H. Pylori Infection and ZE Syndrome
Pharmacology
Management of H. Pylori Infection
- Gram – rod
- Causes erosion of protective epithelial cells -> gastritis or peptic ulcer
H2 antagonist or PPI + Abx
- Metronidazole or amoxicillin/clarithromycin
- PPI + 2 or 3 antimicrobials is standard
- Ex: Ranitidine + Peptobismol + Clarithromycin + Amoxicillin 7-14 days
-Add bismuth if resistant H. pylori
- Ex: PPI + BMT (Bismuth + Metronidazole + tetracycline) 7days
Treatment for ZE Syndrome
- Gastrinoma of the duodenum or pancreas
-Elevated gastrin levels- Peptic/gastric ulcers
- Treatment
High dose PPI until resorting to surgery or chemotherapy for tumor removal
LIPOPROTIENS
Biochemistry
LIPOPROTIENS
Lipoproteins Consist of a Nonpolar Core & a Single Surface Layer of Amphipathic Lipids
The nonpolar lipid core consists of mainly triacylglycerol and cholesteryl ester and is surrounded by a single surface layer of amphipathic phospholipid and cholesterol molecules .These are oriented so that their polar groups face outward to the aqueous medium. The protein moiety of a lipoprotein is known as an apolipoprotein or apoprotein,constituting nearly 70% of some HDL and as little as 1% of Chylomicons. Some apolipoproteins are integral and cannot be removed, whereas others can be freely transferred to other lipoproteins.
There re five types of lipoproteins, namely chylomicrons, very low density lipoproteins(VLDL) low density lipoproteins (LDL), high density Lipoproteins (HDL) and free fatty acid-albumin complexes.
Streptococcal pharyngitis
General Pathology
Streptococcal pharyngitis:
A disease of young people, enlarged lymphoid nodules and keratin plugs in the tonsillar pits is seen Complications include retro-pharyngeal abscess (quinsy)
Cellulitis of the deep tissues of the neck is Ludwig's angina
Scarlet fever ("scarlatina") is a strep throat caused by a streptococcus with the gene to make one of the erythrogenic toxins, Patients have a rash with PMNs
Streptococcal skin infections (Impetigo)
Erysipelas is a severe skin infection caused by group A strep; geographic of red, thickened, indurated areas of the skin are characteristic. Unlike staph infections, there is usually little or no tissue necrosis
Post-streptococcal hypersensitivity diseases include rheumatic fever, post-streptococcal glomerulonephritis, and some cases of erythema nodosum
HERPES SIMPLEX
General Pathology
HERPES SIMPLEX
An infection with herpes simplex virus characterized by one or many clusters of small vesicles filled with clear fluid on slightly raised inflammatory bases.
The two types of herpes simplex virus (HSV) are HSV-1 and HSV-2. HSV-1 commonly causes herpes labialis, herpetic stomatitis, and keratitis; HSV-2 usually causes genital herpes, is transmitted primarily by direct (usually sexual) contact with lesions, and results in skin lesions
Primary infection of HSV-1 typically causes a gingivostomatitis, which is most common in infants and young children. Symptoms include irritability, anorexia, fever, gingival inflammation, and painful ulcers of the mouth.
Primary infection of HSV-2 typically occurs on the vulva and vagina or penis in young adults
Herpetic whitlow, a swollen, painful, and erythematous lesion of the distal phalanx, results from inoculation of HSV through a cutaneous break or abrasion and is most common in health care workers.
Functions of the blood
PhysiologyFunction of Blood
transport through the body of
oxygen and carbon dioxide
food molecules (glucose, lipids, amino acids)
ions (e.g., Na+, Ca2+, HCO3−)
wastes (e.g., urea)
hormones
heat
defense of the body against infections and other foreign materials. All the WBCs participate in these defenses
General chromosome abnormalities
General Pathology
General chromosome abnormalities
The normal human cell contains 46 chromosomes, including 22 homologous pairs of autosomes and one pair of sex chromosomes (XX for female and XY for male). A somatic cell is diploid, containing 46 chromosomes. Gametes are haploid, containing 23 chromosomes.
Aneuploidy
(a) Any deviation in the number of chromosomes, whether fewer or more, from the normal haploid number of chromosomes.
(b) Nondisjunction—a common cause of aneuploidy. It is the failure of chromosomes to pass to separate cells during meiotic or mitotic cell division.
(c) Often seen in malignant tumors.
Deletion: loss of a sequence of DNA from a chromosome.
Translocation: the separation of a chromosome and the attachment of the area of separation to another chromosome.