NEET MDS Shorts
278517
PharmacologySulfasalazine is absorbed well from GIT
Sulfasalazine is poorly absorbed (10-20%) from the GIT .
344873
PhysiologyThe pineal gland produces melatonin in response to light exposure, helping to regulate circadian rhythms and sleep-wake cycles.
242818
Dental MaterialsSmall quantities of camphorquinone, typically less than 0.2 wt%, are sufficient to initiate the polymerization process when the composite resin is exposed to blue light.
644976
EndodonticsThe stabilization of an avulsed tooth typically requires a period of 1-2 weeks. During this time, the tooth is often replanted and stabilized to allow for healing and reattachment of the periodontal ligament.
887130
PathologyIndirect chemical carcinogens differ from direct acting agents in that they
require metabolic activation to exert their carcinogenic effects. This means
that indirect carcinogens must undergo a chemical transformation within the body
before they can damage DNA and induce cancer. Direct acting carcinogens, on the
other hand, can interact directly with DNA without the need for metabolic
conversion. Therefore, the correct answer is:
2. Induce carcinogenicity after chemical transformation
1. Induce carcinogenicity without chemical transformation: This statement is
incorrect for indirect chemical carcinogens. Indirect carcinogens are typically
non-reactive or less reactive in their original form and must undergo metabolic
activation to become DNA-reactive. This metabolic conversion is crucial for
their carcinogenic potential.
2. Induce carcinogenicity after chemical transformation: This is the correct
explanation. Indirect carcinogens require metabolic activation by the body's
enzyme systems, particularly phase I enzymes such as cytochrome P450, to convert
them into electrophilic or reactive intermediates that can interact with DNA.
This activation process can occur in various tissues, often the liver, where
these enzymes are present. The reactive metabolites then form DNA adducts, which
can lead to mutations and ultimately cancer if not repaired properly by the
cell's DNA repair mechanisms.
3. Don’t require metabolic conversion: This statement is incorrect. Indirect
carcinogens do require metabolic conversion to become active carcinogens. It is
the direct acting carcinogens that can interact with DNA without the need for
such activation because they are already electrophilic or reactive in their
original form.
812923
Dental MaterialsThe condensation reaction in silicone elastomers produces ethyl alcohol, which evaporates during setting, contributing to the material's contraction.
227303
ProsthodonticsRetromolar area should be covered in CD or distal extension RPD in order to derive support from the underlying bone which is resistant to resorption.
815592
Dental MaterialsThe elastic range of a wire determines the extent to which it can be deflected and still return to its original shape without permanent deformation. A wire with a high elastic range can be activated to a greater extent before it reaches its plastic range, making it suitable for larger tooth movements.