Shorts

Correct answer: 1) Barr body number = number of X chromosomes minus one. A 47,XXY male has 2 X chromosomes ? 1 Barr body (unlike normal males, 46,XY, who have zero). This buccal smear/Barr body test was historically used for rapid screening before karyotyping became routine.

Correct answer: C) With sudden decompression, dissolved nitrogen (which has high affinity for fatty tissue) comes out of solution as bubbles that can coalesce into emboli — seen in divers/caisson workers ascending too fast, and in aeroembolism from rapid ascent to altitude.

Correct answer: B) Frozen section is a rapid intraoperative diagnostic procedure; stained sections are ready for study about 10 minutes after tissue receipt, versus at least two days for routine paraffin sectioning. It also shows minimal tissue shrinkage and allows demonstration of fat and enzymes, which are lost in paraffin processing.

Correct answer: C) Tumor cells in acute promyelocytic leukemia release procoagulant and fibrinolytic factors that trigger DIC, making APL a classic association with this coagulopathy.

1. People with Xeroderma Pigmentosum (XP):
Xeroderma pigmentosum is a rare genetic disorder that affects the way the skin and eyes repair damage from UV radiation. Individuals with XP have a deficiency in the DNA repair mechanism that normally removes UV-induced lesions. As a result, their cells are more prone to mutations, which can lead to skin cancer. There are several types of XP, and they vary in severity, but all are characterized by extreme sensitivity to UV light, leading to early aging of the skin, pigmentation changes, and a high risk of developing multiple skin cancers, including melanoma, at a very young age.

2. Fanconi Anemia:
Fanconi anemia is another genetic disorder that affects the body's ability to repair DNA. It is not exclusively related to UV radiation but rather to a defect in the repair of DNA crosslinks, which can be caused by various agents, including UV light. Patients with Fanconi anemia have an increased susceptibility to various cancers, including skin cancers. Their cells have a higher frequency of chromosomal instability and DNA damage, which can be exacerbated by UV exposure. However, it's essential to note that the primary cancer risk in Fanconi anemia is related to the underlying defect in DNA repair and not solely to UV light.

3. Telangiectasia:
Telangiectasia is a condition where small blood vessels, especially those in the skin, widen and become visible. While telangiectasia itself does not increase the risk of skin cancer, individuals with certain forms of this condition may have a higher susceptibility to UV light damage. For example, some patients with telangiectasia may also have a genetic mutation or an acquired defect in the skin that results in poor repair of UV-induced DNA damage. This can lead to a higher risk of developing non-melanoma skin cancers like basal cell carcinoma and squamous cell carcinoma. Moreover, telangiectasias are often found in areas of the skin that have been exposed to significant UV radiation, such as the face, neck, and hands, which are common sites for these types of skin cancers.

In summary, all of the conditions mentioned (Xeroderma Pigmentosum, Fanconi Anemia, and Telangiectasia) can increase the susceptibility to UV light-induced carcinogenesis due to their respective impairments in DNA repair mechanisms and skin responses to UV radiation.