12-17-2011, 11:43 AM
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Some imp topic review.. - medicalspirit
Some imp topic review.. - medicalspirit
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Some imp topic review.. - medicalspirit
|
12-17-2011, 11:47 AM
12-17-2011, 12:07 PM
12-17-2011, 01:13 PM
Tzanck cells (multinucleated giant cells) are found in:
Herpes simplex Varicella and herpes zoster Pemphigus vulgaris Cytomegalovirus *Tzanck smears stained by Giemsa (Dif-Quick) or Wright stain demonstrating multinucleated giant cells due to Herpes virus. * dermatomal distribution should help to differentiate.. if they give the case w/ image mneumonic i made: Very , HHeavy, Personal, Computer = Tzanck brand * Please correct or add if I miss anything.
12-17-2011, 01:16 PM
Cauda Equina and Conus Medullaris Syndromes Clinical :
http://emedicine.medscape.com/article/1148690-clinical Thnx. psycmle
12-17-2011, 01:30 PM
12-17-2011, 02:12 PM
Pathogenesis: typical molluscum contagiosum lesion consists of a localized mass of hypertrophied epidermis, which extends down into the dermis without injury to the basement membrane. It projects above the adjacent skin as a visible tumor. There are pathologic changes in the nuclei and cytoplasm, with large hyaline acidophilic granular masses, known as mollsucum bodies, filling the cytoplasm and pushing the nucleus to the edge of the cell.
The center of the lesion consists of degenerating epidermal cells with inclusion bodies and keratin. There is very little inflammatory reaction unless a secondary bacterial infection has occurred. Infection with molluscum contagiosum produces little immunity, with reinfection being relatively common among immunocompromised individuals. http://www.stanford.edu/group/virus/pox/...iosum.html
12-17-2011, 02:16 PM
Infection with molluscum contagiosum virus gives rise to pearly, flesh colored, raised nodules found only in the epidermal layer of the skin. The nodules usually measure 2-5 mm in diameter. The lesions may be found anywhere on the body, but rarely occur on the palms or soles. At the top of each lesion, there is usually an opening through which a distinctive small, white cone can be seen. These lesions are usually painless.
12-17-2011, 02:23 PM
Here's a mnemonic to remind us of the heme synthesis steps
Ala placed in urine cup produces heme Aminolevulinic Acid --> Porphobilinogen --> Uroporphyrinogen --> Coproporphyrinogen --> Protoporphyrin (Protoheme) ---> Heme There are other intermediates in the long pathway but these are the most important ones to remember for the USMLE. Note that the mnemonic also helps us remember that letting urine to stand in porphyria produces the classical red wine urine.
12-17-2011, 02:49 PM
Antigenic Drift:Minor mutation in hemaglutinin or neuraminidase; does NOT require a new vaccine.
* Antigenic shift when 2 type of viruses (for example one human flu virus, another swine flu virus) infect the same swine... from random recombination of genetic material and antigens (Neuraminidase and hemaglutinin) from two virus types appear new type of virus with unique properties. * Antigenic shifts are responsible for the worldwide influenza pandemics. * Antigenic Shift:Major mutation in hemagluttinin or neuaminidase; you DO need a new vaccine * Hemagluttinins help attach the virus to the nasal mucosa; Neuraminidase bores a hole through the mucosa. * How Influenza Viruses Change: Drift and Shift Influenza viruses are dynamic and are continuously evolving. Influenza viruses can change in two different ways: antigenic drift and antigenic shift. Influenza viruses are changing by antigenic drift all the time, but antigenic shift happens only occasionally. Influenza type A viruses undergo both kinds of changes; influenza type B viruses change only by the more gradual process of antigenic drift. Antigenic drift refers to small, gradual changes that occur through point mutations in the two genes that contain the genetic material to produce the main surface proteins, hemagglutinin, and neuraminidase. These point mutations occur unpredictably and result in minor changes to these surface proteins. Antigenic drift produces new virus strains that may not be recognized by antibodies to earlier influenza strains. This process works as follows: a person infected with a particular influenza virus strain develops antibody against that strain. As newer virus strains appear, the antibodies against the older strains might not recognize the "newer" virus, and infection with a new strain can occur. This is one of the main reasons why people can become infected with influenza viruses more than one time and why global surveillance is critical in order to monitor the evolution of human influenza virus stains for selection of which strains should be included in the annual production of influenza vaccine. In most years, one or two of the three virus strains in the influenza vaccine are updated to keep up with the changes in the circulating influenza viruses. For this reason, people who want to be immunized against influenza need to be vaccinated every year. Antigenic shift refers to an abrupt, major change to produce a novel influenza A virus subtype in humans that was not currently circulating among people (see more information below under Influenza Type A and Its Subtypes). Antigenic shift can occur either through direct animal (poultry)-to-human transmission or through mixing of human influenza A and animal influenza A virus genes to create a new human influenza A subtype virus through a process called genetic reassortment. Antigenic shift results in a new human influenza A subtype. A global influenza pandemic (worldwide spread) may occur if three conditions are met: A new subtype of influenza A virus is introduced into the human population. The virus causes serious illness in humans. The virus can spread easily from person to person in a sustained manner. http://www.cdc.gov/flu/avian/gen-info/flu-viruses.htm http://microblog.me.uk/142 |
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