Perplexing FA errata 2010

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I have been looking through the FA errata 2010 and I am having difficulties understanding some of them. Can someone please explain:

1. Pg.71
DNA/RNA/protein synthesis direction

I knw this may sound foolish but they're referring to the small curved arrow in the diagram pointing from the OH to the phosphate group, right?

2. Pg. 224

Erythropoietin can also cause paraneoplastic effects when used in hepatocellular carcinoma and pheochromocytoma


What do they mean by this? That EPO causes paraneoplastic effects when used as a treatment modality for hepatocellular carcinoma and pheochromocytoma? Its unclear to me.

3. Pg.370 Upper Extremity Nerves:

In the entry for the median nerve, the motor deficits for proximal and distal lesions are switched; e.g., lateral finger flexion is a motor deficit associated with a proximal lesions. Remember, proximal lesions will also include the symptoms of distal lesions.


So only the Motor deficit columns are switced for the median nerve? Also does this mean that loss of wrist flexion is caused by a proximal lesion?

4. Pg. 418 Extaocular muscles and nerves:

The information regarding head tilt and CN IV damage is unclear. If the lesion is at the nucleus or occurs before the nerve crosses midline, the head tilt will be [FONT=Arial,Arial][FONT=Arial,Arial]toward ..the side of the lesion. If the lesion occurs after the nerve crosses midline, the head tilts [FONT=Arial,Arial][FONT=Arial,Arial]away ..from the lesion. Note that the lesion results in an eye going up and out, so on testing, the head will tilt to try to align with the good eye.


I really am confused by this one. What does it mean that the head will try to align with the good eye?

 

[Dakayus]

I have been looking through the FA errata 2010 and I am having difficulties understanding some of them. Can someone please explain:

1. Pg.71
DNA/RNA/protein synthesis direction

I knw this may sound foolish but they're referring to the small curved arrow in the diagram pointing from the OH to the phosphate group, right?

Yeah it's 5 to 3 so when you add something on, you add it to the 3' end. Modified bases have a messed up 3' end like cytarabine so therefore nothing can bind too well. I dont have FA in front of me, but i recall it well enough.
2. Pg. 224

Erythropoietin can also cause paraneoplastic effects when used in hepatocellular carcinoma and pheochromocytoma


What do they mean by this? That EPO causes paraneoplastic effects when used as a treatment modality for hepatocellular carcinoma and pheochromocytoma? Its unclear to me.

Epo is a paraneoplastic affect of HCC and pheo and a few others like hemangioblastoma also renal clear cell carcinoma. (all these guys can make it).
3. Pg.370 Upper Extremity Nerves:

In the entry for the median nerve, the motor deficits for proximal and distal lesions are switched; e.g., lateral finger flexion is a motor deficit associated with a proximal lesions. Remember, proximal lesions will also include the symptoms of distal lesions.


So only the Motor deficit columns are switced for the median nerve? Also does this mean that loss of wrist flexion is caused by a proximal lesion?

If the lesion affects it, it's usually at least a few inches above it. The main flexor is flexor digitorum (there's the deep and superficial one, but mostly the deep one) and the lesion there has to be well above that muscle group so it'd be proximal. Remember that proximal is not proximal to the hands, but your core center (I forgot that at first and I made some mistakes 🙄).
Remember all the "claw" lesions are affected proximally and the other ones are distal i.e. median claw, ulnar claw, and a few others are proximal while the other stuff like ape hand would be distal.
4. Pg. 418 Extaocular muscles and nerves:

The information regarding head tilt and CN IV damage is unclear. If the lesion is at the nucleus or occurs before the nerve crosses midline, the head tilt will be [FONT=Arial,Arial][FONT=Arial,Arial]toward ..the side of the lesion. If the lesion occurs after the nerve crosses midline, the head tilts [FONT=Arial,Arial][FONT=Arial,Arial]away ..from the lesion. Note that the lesion results in an eye going up and out, so on testing, the head will tilt to try to align with the good eye.

The book is stupid in this regards. the trochlear nerve keeps the eyeball up so if there's a lesion you're looking down since hte eyeball isn't held up anymore. Thus this is why you have chin tilt downward. The intort/extort crap I sort of forgot, but it occurs mainly when you abduct your eye and it's more of a minor thing. I hope this helps

I really am confused by this one. What does it mean that the head will try to align with the good eye?

....

 

[Dakayus]

fyi I wrote stuff in the quotes since I didn't want to dissect them apart

 

[leviathan]

That errata has its own errata. They try to make you correct mannitol to say it INCREASES ICP. Just be careful when you decide which updates to make.