What assay is commonly used to examine the level of messenger RNA (mRNA) of a particular gene?
- Western blot
- Southern blot
- Reverse transcription polymerase chain reaction (RT-PCR)
- Immunocytochemical analysis
- Enzyme-linked immunosorbent assay (ELISA)
RT-PCR is the only method to quantify the level of mRNA inside the cells. The western blot is an assay to detect protein expression level inside the cells. ELISA is a biochemical technique used mainly in immunology to detect the presence of an antibody or an antigen in a sample. Immunocytochemical analysis is a technique to stain cells using antibody to localize a certain protein within the cells. Southern blot is a technique to detect genomic DNA expression of a certain gene.
During endochondral ossification of the growth plate, the process that most contributes to the longitudinal growth of long bones is
- chondrocyte apoptosis.
- chondrocyte hypertrophy.
- chondrocyte proliferation.
- growth plate matrix synthesis.
The growth plate is divided into 5 distinct zones: reserve, proliferative, maturation, hypertrophy, and vascular invasion. During growth-plate chondrocyte hypertrophy, intracellular volume and an increase in chondrocyte height are responsible for most growth of long bones. Other factors that contribute to bone growth are chondrocyte proliferation and matrix synthesis, but to a lesser degree than chondrocyte hypertrophy. Growth plate chondrocytes undergo programmed cell death (apoptosis) after hypertrophy takes place.
What is the most common complication following interscalene nerve block for shoulder surgery?
- Temporary paresthesia to the affected arm and hand for up to 6 months
- Temporary motor weakness of the affected arm for up to 6 months
- Pneumothorax
- Seizures
- Complex regional pain syndrome
All of these complications have been documented after interscalene nerve block. Other serious complications such as cardiac arrest and respiratory distress have also been noted. However, the most common complication after interscalene nerve block appears to be temporary paresthesia to the hand that can occur in up to 2.3% of the patients
What assay is commonly used to examine the level of messenger RNA (mRNA) of a particular gene?
- [ ] Western blot
- [ ] Southern blot
- [x] Reverse transcription polymerase chain reaction (RT-PCR)
- [ ] Immunocytochemical analysis
- [ ] Enzyme-linked immunosorbent assay (ELISA)
Explanation
RT-PCR is the only method to quantify the level of mRNA inside the cells. The western blot is an assay to detect protein expression level inside the cells. ELISA is a biochemical technique used mainly in immunology to detect the presence of an antibody or an antigen in a sample. Immunocytochemical analysis is a technique to stain cells using antibody to localize a certain protein within the cells. Southern blot is a technique to detect genomic DNA expression of a certain gene.
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During endochondral ossification of the growth plate, the process that most contributes to the longitudinal growth of long bones is
- [ ] chondrocyte apoptosis.
- [x] chondrocyte hypertrophy.
- [ ] chondrocyte proliferation.
- [ ] growth plate matrix synthesis.
Explanation
The growth plate is divided into 5 distinct zones: reserve, proliferative, maturation, hypertrophy, and vascular invasion. During growth-plate chondrocyte hypertrophy, intracellular volume and an increase in chondrocyte height are responsible for most growth of long bones. Other factors that contribute to bone growth are chondrocyte proliferation and matrix synthesis, but to a lesser degree than chondrocyte hypertrophy. Growth plate chondrocytes undergo programmed cell death (apoptosis) after hypertrophy takes place.
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What is the most common complication following interscalene nerve block for shoulder surgery?
- [ ] Temporary paresthesia to the affected arm and hand for up to 6 months
- [x] Temporary motor weakness of the affected arm for up to 6 months
- [ ] Pneumothorax
- [ ] Seizure
Explanation
Interscalene nerve block is a regional anesthesia technique that involves injecting local anesthetic agents around the brachial plexus at the level of the neck. The brachial plexus is a network of nerves that innervate the upper limb and shoulder. Interscalene nerve block provides effective pain relief for shoulder surgery, but it also carries some risks and complications. The most common complication is temporary motor weakness of the affected arm for up to 6 months, which occurs in about 30% of patients. This is due to the blockage of the phrenic nerve, which innervates the diaphragm and controls breathing, and the cervical plexus, which innervates some muscles of the neck and shoulder. Other possible complications include temporary paresthesia (tingling or numbness) of the affected arm and hand, pneumothorax (collapsed lung), hematoma (blood collection), infection, nerve injury, and seizure.
