Notes from world 2

denniskwinn's version from 2015-04-25 18:32


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Lentigosare small tan or brown macules most often seen on the sun exposed skin of a middle-aged or elderly person (eg. face. hands. arms) AKA Liver spots.
Telangiectasiassmall. focal. permanent dilatations of superficial capillaries and venules. usually found in the skin or mucous membranes, will blanch under pressure
petechiaeRed blood cell extravasation into the skin or subcutaneous tissue «5 mm in diameter). (Think Platelet dysfunction)
PurpuraRed blood cell extravasation into the skin or subcutaneous tissue (5 mm to 1 cm in diameter)
EcchymosesRed blood cell extravasation into the skin or subcutaneous tissue (>1 cm in diameter).
tRNA acceptor stembinds the amino acid specific for that molecule of tRNA. Then. tRNA is "loaded" with the appropriate amino acid by the process of aminoacylation. which is catalyzed by aminoacyl tRNA synthase. This stem includes the 3' terminal base residue, and the amino acid is bound to the 3' terminal hydroxyl group.
tRNA 3' CCA tail is added to the 3' end of tRNA as a posttranscripbonal modification in eukaryotes - this tail is utilized by several enzymes to recognize tRNA during protein translation.
tRNA anticodon armcontains sequences which are complementary to the mRNA codon and is read in the 3' to 5' direction.
tRNA T arm contains the TYC sequence which is necessary for binding of RNA to ribosomes. The TYC sequence refers to the presence of thymidine, pseudouridine, and cytidine residues in this arm of tRNA. tRNA is the only RNA species that contains the nucleoside thymidine.
AUG and UAG are mRNA start and stop codons that initiate and terminate translation. respectively.
tRNA is a small, noncoding form of RNA that contains unusual nucleosides such as pseudouridine and thymidine - it has a CCA sequence at its 3' end which is used as a recognition sequence by proteins.
As a consequence of aging. fine skin wrinkles appear secondary todecreased synthesis and net loss of dermal coltagen and elastin.
Isotretinoin is used to treat severe acne refractory to topical therapies. Its main adverse effects are hypertriglyceridemia and teratogenicity. Pregnancy is an absolute contraindication to its use. Sexually active females should be advised to use two forms of contraception and to have monthly pregnancy tests.
Avascular necrosis of the femoral head is associated with sickle cell disease, steroid therapy, SLE and alcoholism - presents with acute onset of hip pain exacerbated by weight bearing, No swelling, erythema or temperature change is seen, MRI is the diagnostic modality of choice,
most common metastatic tumors to the brain lung cancer, breast cancer and melanoma,
Melanocyte embrylologyderived from neural crest cells,
Hypo-or hyperpigmented skin patches that become more visible after tanningcharacteristic of pityriasis versicolor -caused by Malassezia furfur. KOH preparation of skin scrapings reveals a 'spaghetti and meatballs' appearance on light microscopy.
Vitamin that helps in Measles infectionA
Risk factors for osteoporosisSmoking, Menopause, Corticosteroid therapy, Physical inactivity, Caucasian race (immutable) , Low total body weight , Alcohol use
Drug induce lupus linked to drugs that are metabolized by N-acetylation in the liver - s.a. Hydralazine and procainamide - patients that are slow acetylators are at greater risk for developing lupus-like syndrome
Microsporum species causes tinea caprtis, - associated with animal contact
Aeromonas and Vibrio vulnificus may cause cellulrtis re~ted to freshwater or seawater exposure,
Histoplasmosis capsulatum Exposure to bats (e,g, during cave exploration) or to bird droppings in the Ohio and Mississippi, typically causes lung disease resembling tuberculosis.
Sporothrix schenckii dimorphic fungus that causes a subcutaneous mycosis. It is often transmitted by a thorn prick. The disease manifests with nodules that spread along lymphatics.
Local cutaneous adverse effects of chronic topical corticosteroid administrationatrophy / thinning of the dermis that is associated with loss of dermal collagen, drying, cracking, and/or tightening of the skin, tetlangiectasias, and ecchymoses.
Treatment for Lung abscesses in alcoholic patientsclindamycin to cover anaerobic organisms (oral flora).
Nafcillin, methicillin and oxacillinpenicillinase-resistant penicillins active against isotates of S. aureus and S. epidermidis that are resistant to other penicillins. They are not effective against MRSA. however.
Kuppfer cellsmacrophage-derived cells present in the liver that compose part of the reticuloendothelial system - lie within the hepatic sinusoids and. like any other macrophage -serve a phagocytic role in the liver.
Merkel cellsneuroendocrine cells of the basal layer, role in perception of touch - On histology they are often found in association with nerve projections, associated with a rare but highly malignant form of skin cancer known as Merkel cell carcinoma.
Melanocytespigment producing cells of the epidermis, neural crest cells, possess dendritic processes that intercalate between the remaining cells of the epidermis and facilitate the delivery of pigment·laden melanosomes from the melanocyte to the keratinocytes. Darkening of the skin on exposure to u~raviolet rays is not due to a proliferation of melanocytes: rt is due to an increase in production of melanin by a stable number of melanocytes. Dark-skinned people constrtutively produce a large amount of melanin. but they possess roughly the same number of melanocytes as fair-skinned people do.
Langerhans cells dendritic cells found in the skin that act as professional antigen presenting cells. These cells are derived from the myeloid cell line and they possess characteristic racquet·shaped intracytoplasmic granules known as Birbeck granules.
Classic triad of Reiter syndrome (reactive arthritis) non gonococcal urethritis, conjunctivitis (possibly with anterior uveitis), and arthriti - most common cause of asymmetric inflammatory arthritis of the lower extremities in young men. HLA-B27 associated arthropathy within several weeks of a GU (especially non gonococcal urethritis) or GI (especially bacterial enteritis) infection, It belongs to the group of seronegative spondyloarthropathies (including ankylosing spondylrtis) and can cause sacroilirtis in about 20% of cases,
Xeroderma pigmentosumdevelops due to a defect in DNA excisional repair - characterized by increased sensitivity to UV radiation and a high incidence of all forms of cutaneous malignancy.
Pemphigus vulgarisautoimmune, autoantibodies against desmosomal proteins 3 and 1.
Bullous pemphigoidautoimmune, autoantibodies against hemidesmosomal proteins.
Graft·versus·host disease is mediated by T-Iymphocytes of the donor tissue that are sensitized against MHC antigens of recipient. Skin. liver and intestine are commonly involved.
Fibular neck fracturescan common peroneal nerve lesion this nerve. causing weakness of dorsiflexion (deep peroneal nerve) and eversion (superficial peroneal nerve) of the foot as well as loss of sensation over the dorsum of the foot. Inversion and plantarflexion would remain intact due to the action of the tibial nerve.
Polymyosrtis presentation with symmetric proximal muscle weakness. Muscle biopsy reveals inflammation. necrosis and regeneration of muscle fibers. Preceding damage to myocytes with subsequent over-expression of MHC class I proteins on the sarcolemma leads to infiltration with CD8+ T lymphocytes and myocyte damage.
Reactive arthritisHLA·B27 spondyloarthropathy, follows infection by Chlamydia. Campylobacter. Salmonella. Shigella or Yersinia It is an asymmetric large joint arthritis with sterile synovial fluid on joint aspiration.
Collagen synthesis 1. Procollagen is synthesized in the ER of such as fibroblasts. 2. It is released into the extracellular space by transport through the Golgi apparatus and converted into collagen by procollagen peptidases that cleave the water soluble. non-helical N-and C-terminal to form collagen. 3. Collagen monomers are then covalently cross linked with each other after certain residues are oxidized by lysyl oxidase.
AlkaptonuriaAutosomal recessive, lack of homogentisic oxidase blocks the metabolism of phenylalanine and tyrosine at the level of homogentisic acid, leading to an accumulation of homogentisic acid which is excreted in the urine and turns black when oxidized . Alkaptonuria also causes ochronosis - blue-black pigmentation that is most evident in the ears, nose, and cheeks.
5'-phosphoribosyl- l'-pyrophosphate (PRPP) synthetase activating mutation can cause Gout due to increased production of purines leading to hyperuricemia,
Colchicine mechanism and functioninhibits chemotaxis of nphils by preventing microtubule formation useful in the acute management of gouty arthritis
CD 18 Deficiency Autosomal recessive Leukocyte adhesion deficiency leads to the inability to synthesize integrin which are necessary for leukocytes to exit the bloodstream - sequelae of this illness include recurrent skin infections WITHOUT pus formation, delayed detachment of the umbilical cord and poor wound healing.
Terbinaflneused for treatment of dermatophytosis. It inhibits synthesis of fungal membrane ergosterol by suppressing the enzyme squalene epoxidase.
Apocrine sweat gland secretion odorinitially odorless but can become malodorous secondary to bacterial decomposition on the skin surface.
Vitamin D synthesis Sunlight exposure catalyses the first reaction in the chain of active vitamin D synthesis: 7-dehydrocholesteroi transforms to cholecalciferol (Vitamin D3). Then. 25-hydroxylation occurs in the liver and the kidney enzyme 1-alpha hydroxylase catalyzes the final step in the synthesis of active vitamin D
femoral neck fracture blood supplymedial femoral circumflex artery provides the majority of the blood supply to the femoral head and neck: injury to this vessel can cause avascular necrosis of the femoral head.
Gout results from the deposition ofmonosodium urate not uric acid, in the joints and soft tissues. Under polarized light, monosodium urate crystals appear needle-shaped and negatively birefringent. The subcutaneous deposition of monosodium urate leads to the formation of tophi.
Antivirals Acyclovir, the acyclovir prodrug valacyclovir, famciclovir, and ganciclovir are all nucleoside analogues that require conversion to nucleoside monophosphates by herpesviral kinases. Cidofovir is already a nucleoside monophosphate and therefore only requires cellular kinases for conversion to the active nucleoside triphosphate form.
Infant Down syndrome presentation upslanting palpebral fissures, bilateral epicanthal folds, a flat nasal bridge and a large tongue - other common features are congenital heart defects, duodenal atresia and Hirschsprung disease, increased risk of leukemia,
Infant botulism presentationconstipation and poor sucking followed by muscle paralysis - usually less severe than adult - happens from being fed honey
Hirschsprung disease presentation abdominal distention, bilious emesis, and failure to pass meconium
Phenylketonuria presentationmanifests with developmental delay, mental retardation, mousy body odor and fair skin coloring,
Congenital hypothyroidism presentation presents soon after birth with hypotonia, poor feeding, jaundice, macroglossia, constipation and umbilical hernia
Candida skin test gauges the activity of the cell mediated immune response - run by macrophages, CD4-and CD8 T-lymphocytes and NK cells.
HCTZ SEdecrease in the intravascular fluid volume stimulates aldosterone secretion and leads to increased excretion of potassium and hydrogen ions in the urine → hypokalemic metabolic alkalosis. Hypokalemia manifests with muscle weakness and cramping.
Ehlers·Danlos syndromeheritable connective tissue disease typically associated with abnormal collagen. over-flexible (hypermobile) joints. over-elastic (hyperelastic) skin and fragile tissue susceptible to bruising, wounding and hemarthrosis.
Bartonella henselaecat·scratch disease. baciltary angiomatosis and culture-negative endocarditis. Characterized by low fever, lymphadenopathy and a self limited course