JavMD
Forum Junior
Topics: 5
Posts: 77
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Hi, I started my odissey today.
A little about me.
-Mexican, single, still med student
-Planning to take the test in 3-4 months. Last week of January.
-Aiming high for residency. Surgically oriented.
I started with Biochemistry, to be more precise, Cell and Molecular Biology (first part of Kaplan LN). And High Yield Cell and Molecular Biology. I plan to finish the Biochem LN in 7 days. And then continue with Micro/Immuno.
I learn a lot today. Did you know there are 4 phospholipids in the cell membrane?, outer leaflet (phophatidylcholine and sphingomyelin) and inner leaflet (phophatidylserine and phosphatidylethanolamine), and the enzyme flippase maintains the asymmetry.
I only knew that it was a double layer phopholipid membrane, with integrated proteins and that it had a hydrophobic and hydrophillic side.
Anyways, Ill continue to learn new stuff. Especially in this subject since I think I lack enough material from my school.
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| JavMD
Forum Junior
Topics: 5
Posts: 77
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I forgot. My goal is to get at LEAST a 235, but Im actually aiming for a (dont laugh please) 270-280. So please, test me. Im kind of masochist, Bombard me with difficult questions. Challenge me. And Ill appreciate your effort and thank you with alacrity.
Things I learn today:
-Specific inhibitory action of Quabain- competitor for K binding site.
-Met the ABC transporter superfamily.
Things I review:
-Cell cycle
-Gene expression occur when?
-DNA replication when?
-Size of gene and chromosome
-Components of nucleotide
-Purines and Pyrimidines and differences, amine group, methyl group, etc.
-Chargaffs rules
-B-DNA and Z-DNA
-Hyperchromic effect @ 260 nm
-Topoisomerases (action) and DNA gyrase
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| Miss Julie
Forum Newbie
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Posts: 7
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Hi!
Some questions for you... as I just went through cell biology too.
In which leaflet is another phospholipid which you didn't mention - phosphatidylinositol? Why is this quantitatively minor membrane component important?
Most of the cell membranes contain protein/phospholipids in proportion 1/1. Which cell membranes contain protein/phospholipid about 18%/76% and which 76%/24%? The significance of these different proportions?
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| JavMD
Forum Junior
Topics: 5
Posts: 77
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Wow, NICE. Miss Julie. 
1. In which leaflet is another phospholipid which you didn't mention - phosphatidylinositol? A= external leaflet, although you may find phophatidylinositol phosphates isomers in the internal leaflet
2. Why is this quantitatively minor membrane component important?
A= this one is easy, PI is a reservoir of arachidonic acid in membranes, it plays also a role in signal transmission across membranes (phopholipase C > PI > diacylglycerol > protein kinase C active).
3. Most of the cell membranes contain protein/phospholipids in proportion 1/1. Which cell membranes contain protein/phospholipid about 18%/76% and which 76%/24%? The significance of these different proportions? A= myelin has a 1:4 relation, this is especially important in the "insulation" in the Ranvier nodes; as for the 76/24 relationship Im not sure, it should be in cells with multiple receptors or ion channels, most probably endocrine (pancreas).
Where did you study from? That info doesnt come "per se" in HY cell and molecular biology, neither Kaplan LN, nor BRS cell biology and histology.
Now, which phospholipid is always in the inner leaflet and youll find it in the outer leaflet only when the cell dies, it is in fact an apoptosis marker.
Membrane phospholipid that does not contain glycerol?
Hey, thanks for the refreshing questions!
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| JavMD
Forum Junior
Topics: 5
Posts: 77
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Yesterday was a heavy day, went over:
1. DNA replication and repair
2. Transcription and RNA processing
3. Genetic code, mutations and translation
4. Genetic regulation
5. Recombinant DNA
Last two werent so clear to me, but this is my first read so ill keep up with my schedule and ill review them at the end. Afterall im satisfied after studying for 8-10 hrs. But i still struggle with time interruptions, having to go to symposiums, lead a group of students, and my interaction with friends and family sometimes prolong more than expected.
Miss Julie you seem like a cool person, what are you studying now?
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| Miss Julie
Forum Newbie
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Posts: 7
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Hi again, JavMD!
I like your attitude of aming the best result. Good for you! You also seem to have a good sense of humor which to my mind, is essential for doctors.
Well, you also made me revise my knowledge.
1.I'd say though that phosphatidylinositol is in the inner leaflet. No???? (source: Alberts, B et al "Molecular Biology of the Cell").
3.I'm not sure about the cells of pancreas, but your notion makes sense.... should find out.
76/24 - in the inner membrane of mitochondrion (makes sense if to think about the function - place of the ezymes of the respiratory chain, place of ATP synthase, also contains variety of transport protein).
Your questions:
"Now, which phospholipid is always in the inner leaflet and youll find it in the outer leaflet only when the cell dies, it is in fact an apoptosis marker."
Phosphatidylserine. (I didn't know the answer... had to look up. Thanks!
 )
"Membrane phospholipid that does not contain glycerol?"
Sphingomyelin.
Well, it's good to discuss. I think I'll remember these things much better now.
It's nice that you think that I seem cool.... Actually, I feel rather a looser myself, considering motivation. I am quite amazed by people here who are highly motivated and hard-working. It's hard for me to stay motivated. Background: old IMG, medical school grad. 1999, 1+3 years of residency in the home country, 5 years of running my practice, in the USA because of the family, a small child...
Regarding my study material - started with "Color Textbook of Histology" by Gartner and Hiatt which has quite a thorough molecular cell biology, an excellent medical biochemistry text in my mother tongue which I just like a lot + HY later. I also used "Molecular Biology of the Cell" if wanted to understand some topics more deepely. I also liked this site: http://www.cytochemistry.net/Cell-biology/#Cell%2....
Well, my approach is rather untraditional and probably ineffective in the end, at least if one wishes to have a quick result or is a recent graduate or medical student who have studied it all recently - using different resources, trying to gain rather good understanding in the first reading, quite slow space.... but I have to admit that I'm enjoying this learning process - learning rather for myself to gain the knowledge than succeeding in the exam.
At the moment - biochemistry, neurophysiology.
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| dirtyplay28
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very good, but reading for pleasure and reading for exam are two different things. dont go to slow... bc as u will see shortly its tooo much information , and if you read slow and super detailed than by the time you finish all subjects it will be 4-5 months from now and you will forget where u started. im just trying to help, bc ur doing the samthing i did in the beginning! than someone told me to read though everything fast, than cycle it , read it fast again, u will pick up more details each time. do this twice than start on the question qbanks. u willnow know how the questions r asked soo differently! than read fast again.... and whoa la exam day!!! 
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| JavMD
Forum Junior
Topics: 5
Posts: 77
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You are right Miss Julie this is so helpful, we wont forget these questions now. As for the PI, my bad I misinterpreted the info "Phosphatidylinositol is known to be the anchor that links a variety of proteins to the external leaflet of the plasma membrane via a glycosyl bridge " from http://www.lipidlibrary.co.uk/Lipids/pi/index.htm
I really enjoyed this, I learned a lot, thanks. Hope you wont stop now.
Loser???, not at all, are you kidding me? You are cool, if you enjoy to read and learn for your own satisfaction.
We all had experienced lack of motivation, this is my third attempt to start to study for the USMLE, just continue, dont stop, even when you dont feel like it, just tell yourself "My goal is this page, just this page." Then youll feel proud and continue, just keep at it.
And I completely agree with you dirtyplay28, I have read a lot of biochemistry that I should get a PhD now. The bad thing is I already forgot a lot of what I have read by now. That is why Im trying to go fast now. 7 days for Biochemistry, 10 for Micro/Immuno, and so on. During my first read. Just to understand the concepts and get familiar with my material. In the second read Ill concentrate in details and memorization. Also recall by doing qbanks. Third read to fine tune.
But Im trying to not fall in the trap of quantity over quality. And sometimes in the last chapters I find myself being mechanical, reading for the sake of reading and achieving my goal for the day.But understanding little.
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| Miss Julie
Forum Newbie
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Posts: 7
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Thank you, guys for the advice and support!
I agree with you - one should be very well-organized and efficient to ace these exams (and also what would follow - residency and a life of a doctor). As I told, my problem is motivation, precisly, deciding whether I want to go through it again or not, whether I want this kind of life or not. Just very personal stuff.
Take care and best luck with your preparation!
P.S. Thanks for taking time to write about your experience despite the busy schedule. I guess, seeing other people being able to make their dreams come true, gives hope and motivation to people like me, who still hesitate.
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| Miss Julie
Forum Newbie
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Posts: 7
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Hi JavMD! How's going with biochemistry?
Here're some questions if you wish to answer. Problems, I was contemplating yesterday...
1.Patient A has high levels of VLDL in the blood? What should he reduce in his diet?
2.Patient B has been trying to lose weight for several months and he's lost 2 lb. He asks you how many calories he should eat less than he expends per day to lose 1 lb in one week while continuing the same lifestyle? (Assuming that weight loss would be solely due to adipose tissue. Adipose tissue contains 85% fat).
3. Patient C with type I diabetes is admitted to hospital because of ketoacidotic coma. His respiration is deep and rapid (Kussmaul) and he's dehydrated. What's the biochemical bases of Kussmaul's breathing and dehydration?
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| JavMD
Forum Junior
Topics: 5
Posts: 77
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After a long time away from my computer. I'm back.
Finishing with Biochemistry and I'll be starting Microbiology/Immuno.
But I'll have to put away my prep for the weekend since I'm gonna be taking a course (ACLS). Anyway, it feel so nice to come back.
Miss Julie, it is great to have friends that support you and challenge you. Thanks.
Hope you are doing great.
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| JavMD
Forum Junior
Topics: 5
Posts: 77
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Patient A. Should reduce his triacylglycerol consumption.
Patient B. I don't quite know the specific answer for this one. Since weight loss is dependant of BEE and the BEE is dependant of several factors (sex, weight, height, activity). Clinically, the way that I would approach a patient like this, would be by using the Harris-Benedict formula and making adjustments from there. Altough usually the reduction is around 500 kcal per day.
Patient C. Ketotic patients have metabolic acidosis, therefore the Kussmaul breathing is a way to compensate (respiratory alkalosis), to maintain the acid-base homeostasis.
Now, usual USMLE S1 qs:
1. Patient with a prolonged omphalorrhexis, you should suspect: ???
2. Patient presents to the clinic with a CD4+ count of 146, and pneumonia; Most probable etiologic agent?? Treatment??
3. Same patient one week later goes to ER with dyspnea, normal labs. How should you treat him?
a. Ascorbic acid
b. Oxygen
c. Methylene blue
d. Pleurocentesis
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| Miss Julie
Forum Newbie
Topics: 0
Posts: 7
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Hello JavMD!
Nice to see that you've progressed well with your studies! I'm still dealing with biochemistry (too slow, but at least I've become more consistent with my study. So, I guess, I'm doing ok for now.)
You did well with your answers.
1.I'd answer differently here though. Pt A with high levels of VLDL in his blood should lower carbohydrates in his diet as triglycerids of VLDL are produced mainly from dietary glycose.
2.Yes, correct answer. 1 lb is lost whenever one eats 3500 kcal less than expends (3500/7=500 kcal/day) Of course there is no time for big calculations in USMLE, but in real clinical setting, I'd just use old-fashioned method: 1lb = 0,455kg
100g fat tissue - 85g fat, 455g fat tissue - (85x455/100)g fat
1g fat - 9 kcal, (85x455/100)g fat - 9 x (85x455/100)kcal = 3480kcal
So about 3500 kcal per week = 500 kcal per day.
Your questions now. Thank you for posting, it's really stimulating!
As I'm still sitting with my biochemistry, I'm in trouble answering....
1.Omphalorrhexia - I don't know 
2.Well, I'm in trouble here too... My answer would be Pneumocystis carinii and treatment trimethoprim-sulfmethoxazol. But if I'm correct, in developed countries, incidence of Pneumocystis carinii pneumonia in pt with AIDS has decreased due to prophylaxis. On the other hand, cases of bacterial pneumonia (Streptococcus pneumonia, Pseudomonas aeruginosa) are quite frequent and they may give cavities.... So I'm not sure. What's the correct answer?
3.I'd assume d - pleurocentesis because of the pneumothorax.
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| JavMD
Forum Junior
Topics: 5
Posts: 77
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Hello again,
Im sorry if I misused the term, but what I meant by omphalorrhexis was the rupture and fall of the umbilical cord after birth (generally 7-10 days). If it takes longer it might be a sign of LAD I, if it is early is a sign of LAD II.
PCP MCC of pneumonia in AIDS patients. But my point was that, as I learned lately, is no longer Pneumocystis carinii, now it is Pneumocystis jiroveci (they changed the name). The treatment you were right SMTX.
Last question comes from Dr Goljan himself, SULFA AND NITRATE DRUGS CAUSE METHEMOGLOBIN, therefore the treatment would have been methylene blue, ancillary treatment ascorbic acid.
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| JavMD
Forum Junior
Topics: 5
Posts: 77
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I ve been really busy lately so no time to post as much. Hopefully after this month I will get my usual rythm. anyway Im really excited of all the things happening to me right now.
So I apologize, if it takes longer for me to answer you.
Thanks
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| acintya
FOCUS on your Goal!
Topics: 7
Posts: 765
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I liked this discussion! Keep it up MissJulie and JavMD!
___________________
The more a memory has been encoded, elaborated, organized, and structured, the easier it will be to retrieve.
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| JavMD
Forum Junior
Topics: 5
Posts: 77
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Great that you stop by, acynthia.
Even better that you like it.
Anyways, just a thought.
"Nobody regrets over-studying, we all regret not studying enough. And it is always better to have a superb score in USMLE, than a mediocre one. Even if you are not aspiring for a super duper competitive specialty."
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| Miss Julie
Forum Newbie
Topics: 0
Posts: 7
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Hello!
JavMD, thanks for pathology explanations. As I see, there isn't much to do with my "old knowledge". So I'm eager to finally move on to pathology too.
And no need to apologise! It's your journal and you should do it as it's most useful for you.
Acintya, thanks for the encouragment!
Here are some questions (some may be a bit awkward, sorry!) from the notes I made for myself on biochemistry, molecular biology. No obligation to answer if it takes meaninglessly lot of time, but you may just think if you know the concepts behind them.
- Pt. A with non-Hodgkin lymphoma has been treated with methotrexate. The response has become poor. What could be the mechanism that he has become resistant to this drug?
- Pt. B with tonsillitis, has penicillin-allergia. He is treated with erythromycin. After a few days complains of troublesome diarrhoea. Erythromycin binds to bacterial 50S ribosomal subunits and inhibits translocation. Why it still may give adverse effects?
- Which enzyme, hexocinase or glycokinase, would have the largest increase of velocity as the intracellular glycose concentration increases from 5 mM to 10 mM?
- Pt. C with SEL. The antibodies against snRNA were found in her blood. What's the process snRNA takes part in?
- Pt. D of Mediterranean ancestry. Cytogenetics found a mutation in her both allels of a gene: at the 5'-end of the first intron an AT has replaced a GT. What's the phenotype: beeta0- or beeta+- thalassemia?
- Human tRNA contains, except: a)Thymine; b)Cytosine; c)Desoxyribose; d)Uracil?
- Pt. E with anorexia nervosa. She has hypochromic anemia. Her globin synthesis is low. In what level does the globin synthesis inhibation take place? Mechanism?
- Pt. F with type II diabetes. His HbA1c was measured to indicate his average blood glucose levels in previous weeks. HbA1c is a minor component of adult HbA, a result of posttranslational glycosylation. Which ezyme catalyzes the reaction of glycosylation?
Take care, guys!
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| JavMD
Forum Junior
Topics: 5
Posts: 77
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I been progressing slowly, but that is to be expected in the first read.
Anyway, I find myself a little more confident now.
Havent heard from you Miss Julie, hope you are fine also.
And finally I scheduled my test, but I also need to take the TOEFL, so ill be scheduling that one also.
Also my girlfriend got mad at me because she kept calling me during my study blocks, and I told her "Im studying right now, Ill call you back as soon as I finish this block". I thought she would be more supportive in that respect, especially since she is a med student / graduate too.
Ive set my mind on my objective, even if that means sacrificing my relationship. (Im actually not cold, but I realize that whoever wants to be with me is going to have to adapt to being a "doctors girlfriend / wife" thing. Meaning, she has to understand I love her entirely but sometimes medicine and the hospital is first. This may not apply to every specialty, derm, radio, and such; but it is essential for others neurosurg, cardiovascular surg, gen surg, transplant surg.)
So I guess Im actually married with medicine. And my commitment is to her.
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| JavMD
Forum Junior
Topics: 5
Posts: 77
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Im already on the middle of Physio.
Slow progress but Im getting confident.
After that Ill start Patho.
Just finished Cardio and starting Respiratory.
Im starting to integrate the knowledge, and it all comes together fine.
I slacked off today. Hopefully tomorrow Ill dedicate at least 4 hrs.
Thinking of working part time, but I dont know if is possible, as Im in my first read and Ill take test in March, Ive already fell back on the schedule, but I need the money.
What do you guys think?
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| milee99
Forum Guru
Topics: 36
Posts: 777
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hey cool discussion people!!
___________________
Do not pray for easy lives,Pray to be stronger men; Do not pray for tasks equal to your powers, Pray for powers equal to your tasks; Then the doing of your work shall be no miracle, but you shall be the miracle.
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| JavMD
Forum Junior
Topics: 5
Posts: 77
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Found myself a study partner.
She just quit her job to dedicate 24-7 to prep. We should all learn from her.
Have great expectations for her, hopefully she will stand up to the challenge.
Havent been able to sleep well lately, can you tell by my erratic flow of ideas?
Ill start to post back my progress in the forum now that i have a net connection again.
Keep the spirit up people. This job aint easy but it is simple. The harder you work the higher your score.
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| Miss Julie
Forum Newbie
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Posts: 7
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Hey JavMD!
Good to see you! Keep your progress coming!
BLW, I've been thinking of what you said in one of your previous post. And here is my experience, not an advice ("Never give an advice", was the best guidance I got from my pshychology professor) - it's good to be passionate about your profession, but it's just a profession, not the whole life. From time to time medicine will make you frustrated, sad, angry, helpless.... and there is nothing better than having a supportive family to overcome these moments. I had to give up my career (at least for a while) to be together as a family and I still don't regret it. Being a parent and a wife has made me a lot smarter, I think. But enough of prattling....
I've been a bit disorganized lately, but still been able to keep going and be more or less persistent. Right now I'm dealing with cardiovascular pathology and I must say that it's quite good to finally understand a bit of antiarrhythmics and how they work.
Take care!
Edited by Miss Julie on 01/16/08 - 12:44 PM
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| unique1
InGodITrust
Topics: 19
Posts: 1,410
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Acyntia wrote:I liked this discussion! Keep it up MissJulie and JavMD!
I like it too . Good luck with your studies.
___________________
I can't change the direction of the wind, but I can adjust my sails to always reach my destination.
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| milee99
Forum Guru
Topics: 36
Posts: 777
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hi
hope your preparation is going well
about your qbank question ..
i will be doing kaplan qbank as well as usmleworld
so if u are going to do just one qbank then you should do two good reads of kaplan books or whatever you plan to read and then do the qbank
if you are going to do both , then you can take one q-bank preferably kaplan qbank if you are reading kaplan books and do it with your reading .. subjectwise ..
it tells what topics are important and with what point of view one should read them(since almost all that is there in kaplan is important , but often i ended up memorising some facts that were only supposed to support conceptually oriented questions and did not memorise some things that were important , also we tend to concentrate more on facts that we did not know before like say herbal medicines in the pharmac chapter when toxicology and immunomodulators are equally important ) .
also if you wait for the read to be done before qbanks , and you want to do both qbanks, there may not be enough time left until exams to do both
so do one with the books and other like tests .
that is just my opinion
also do all topics from all books and then if you have time then you can go into intricate details from reference books . knowing everything of few topics and less than necessary for others may be dangerous since usmle q's are randomly selected
all the best
take all this with a pinch of salt , as till i take step 1 and get my scores , i am as inexperienced as you
it is like one blind man leading the other
try asking people who have already taken exam
this is the input that i got from some others
keep studying !!!
___________________
Do not pray for easy lives,Pray to be stronger men; Do not pray for tasks equal to your powers, Pray for powers equal to your tasks; Then the doing of your work shall be no miracle, but you shall be the miracle.
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