Let's try again, join me for study group NBDE I may/June 2010

[blissonearth]

Hi friends, let's continue the closed thread here. No promoting any materials here, just prop some in doubt questions as our exam is approaching fast.

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[mosaicthoughts]

Hi friends, let's continue the closed thread here. No promoting any materials here, just prop some in doubt questions as our exam is approaching fast.

Ya i agree with her

 

[dontist]

yep.. lets start over again.. only discussing questions..but i would like to request alll ppl who are postin questions.. to ask it from a reliable source and not like i have read it somewehre... i m not sure but this is what somewhat the question looks like.. and i forgot the options.. sorry..

lol.. pl be specific and precise.. we will discuss and find solution of the questions .... hoping there are no errors in questions and they are from reliable sources.. hope it makes sense..

i m just requesting you guys as to make less confusion and be more fast.. i have seen many discussions on a questions and after all.. the answer still remains unsolved.. i know sometimes even ADA questions have mistakes but we should try to minimize the errors, though we cannot completely eradicate it.. as all here in this forum are comin to know more and learning.. so no one is prefect.

thanks.. and keep up the spirit.. let the questions fall from all around...

 

[Kash]

anybody interested in group study please pm me.

 

[dontist]

ok i have a question...

 

[Kash]

I think the answer might be
4. structural relation to D glyceraldehyde

Please correct me if i am wrong.

 

[blissonearth]

wow, that's hard....

 

[blissonearth]

anybody interested in group study please pm me.

If you are interested to have your own group study, you can post this on the thread called "looking for partner/study" on NBDE forum. THanks!

 

[dr niki]

I think the answer might be
4. structural relation to D glyceraldehyde


hey can u explain the answer with the structural formula..
one with R n chain..
thanks..

 

[blissonearth]

I couldn't find any other explanation other than this :

"The ability of some compounds to rotate the plane of polarized light because of the asymmetry of the molecule. If the plane of light is rotated to the right, the substance is dextrorotatory and is designated by the prefix (+); if laevorotatory (rotated to the left), the prefix is (-). A mixture of the two forms is optically inactive and is termed racemic.

Sucrose is dextrorotatory but is hydrolysed to glucose (dextrorotatory) and fructose, which is more strongly laevorotatory so hydrolysis changes optical activity from (+) to (-); hence, the mixture of glucose and fructose is termed invert sugar.

(The obsolete notation for (+) was d- and for (-) was l-; this is distinct from D- and L-, which are used to designate stereo-isomerism; see D-.)"

Anyone else can help ?

 

[Truth seeker]

ok i have a question...

Answer: 4
In D/L system of nomenclature , glyceraldehyde is used as the configurational standard for carbohydrates . Hope it helps , also if someone can add more info shall be glad to hear from them .

 

[blissonearth]

Choose 2 from 5:

Laboratory test to check the normal physiology of kidney are the amount of :
1. Glucose
2. Urea
3. Protein
4. Creatinine
5. Urine

 

[wadent]

i think the answer is creatinine !!

 

[blissonearth]

2 answers, wadent

They are urea and creatinine, while the amount of urea can be variable in normal values, around 30 gr, but the amount of creatinine is about constant.

Guys, if you have anything to study and found something interesting, please share it to us... I found this interesting, too.

 

[happyk9]

I think cretinine is the correct answer. Cretinine is similar to inulin which is the standard agent to test GFR. The only difference is there is slightly reabsorption of cretinine after it is filtered.

 

[blissonearth]

Mainly creatinine, but BUN (urea) test also performed to check if there is kidney malfunction.

Check this out :

After history and physical exam are complete, the initial steps in checking patients' kidneys are performing a (1) urinalysis and obtaining a (2) serum creatinine and/or (3) serum urea ("blood urea nitrogen", "BUN") level. Next, you may check (4) ability to concentrate urine.

• Both creatinine and BUN are included on the common chemical profiles. You can check the ability to concentrate urine using a hygrometer, refractometer, or dipstick.

Indications for these tests:

• Newly discovered high blood pressure or diabetes
  Abnormal urinalysis (anything more than "trace protein" or "honeymoon cystitis")
  Any medical problem serious enough to admit the patient to the hospital

This section focuses on how to use blood tests to assess kidney function. Other units will introduce urine testing.
You should probably refer to a nephrologist when a man's creatinine exceeds 2.0 mg/dL, a woman's 1.5 mg/dL (NIH, 1993).
UREA ("BUN")

Urea, as you remember, is a relatively nontoxic substance made by the liver as a means of disposing of ammonia from protein metabolism.
*Urea has MW 60, of which 28 comes from the two nitrogen atoms.

• Clinical chemists used to measure only the nitrogen in urea, hence the "urea nitrogen" measurement on lab reports.
  The real concentration of urea is BUN x (60/28), or BUN x 2.14. But everyone thinks in terms of BUN units.
  Normal blood urea nitrogen is 8-25 mg/dL (2.9-8.9 mmol/L).

Urea is filtered by the glomerulus. If the glomerular filtrate is flowing slowly through the proximal tubule, urea tends to be passively reabsorbed and return to the bloodstream.

• Blood urea levels are quite sensitive indicators of renal disease, becoming elevated when renal function drops to around 25-50% of normal (remember the kidney has great functional reserve). The interpretation of the BUN is usually straightforward, though there are a few things to remember.

Increased BUN is, by definition, azotemia. It is due either to increased protein catabolism or impaired kidney function.

 

[tinman831]

There's tons of question/answer threads already. Why start another one?

 

[blissonearth]

Guys, can you please tell us how long the average of you to finish one subject (without practicing the exams) if you study average 7-8 hours a day ? I am asking because I really don't have the answer of this as I am jumping from one subject to another, if I got stuck on one subject, I go to the other one ... Thanks!

 

[happyk9]

It depends. Sometimes I will change the subject if I find myself very difficult to focus on one subject.

Sometimes I study them together. For example, I will study the kidney histology, physiology and pathology together. Sometimes I find it is fun and easier.

Make a good and realistic plan is the key.

 

[dr niki]

I couldn't find any other explanation other than this :

"The ability of some compounds to rotate the plane of polarized light because of the asymmetry of the molecule. If the plane of light is rotated to the right, the substance is dextrorotatory and is designated by the prefix (+); if laevorotatory (rotated to the left), the prefix is (-). A mixture of the two forms is optically inactive and is termed racemic.

Sucrose is dextrorotatory but is hydrolysed to glucose (dextrorotatory) and fructose, which is more strongly laevorotatory so hydrolysis changes optical activity from (+) to (-); hence, the mixture of glucose and fructose is termed invert sugar.

(The obsolete notation for (+) was d- and for (-) was l-; this is distinct from D- and L-, which are used to designate stereo-isomerism; see D-.)"

Anyone else can help ?

thanks blissonearth n truthseeker...

 

[dr niki]

All posterior teeth have lingual heights of contours in the junction of the cervical to the middle 1/3rd of the crown , except one..

1. Mandi 1st premolar
2. Mandi 2nd pm
3. maxi 1st pm
4. maxi 2nd pm
5. maxi 1st molar




any answer?

 

[blissonearth]

It depends. Sometimes I will change the subject if I find myself very difficult to focus on one subject.

Sometimes I study them together. For example, I will study the kidney histology, physiology and pathology together. Sometimes I find it is fun and easier.

Make a good and realistic plan is the key.

Thank you!. I am glad I am not the only one who jumps from one to another.

 

[anniestar]

All posterior teeth have lingual heights of contours in the junction of the cervical to the middle 1/3rd of the crown , except one..

1. Mandi 1st premolar
2. Mandi 2nd pm
3. maxi 1st pm
4. maxi 2nd pm
5. maxi 1st molar




any answer?

it is mandibular 1st premolar which has it in the occlusal third.
you won'tfind this anywhere but i remember reading it on SDN.this question had troubled me too.this is an exception which you need to remember.

 

[part1]

hi
i would like to join as well

 

[dolphin12]

hi all

from wher do u ppl see diagrams for anatomy-esp-gastrointestinal anatomy....those peritoneum etc are confusing...if i go in bits and pieces...is ther any consolidated pic with all the structures....suggest pls...thank u -i went thro wikipedia...but not satisfactory...

 

[blissonearth]

hi all

from wher do u ppl see diagrams for anatomy-esp-gastrointestinal anatomy....those peritoneum etc are confusing...if i go in bits and pieces...is ther any consolidated pic with all the structures....suggest pls...thank u -i went thro wikipedia...but not satisfactory...

you could learn it easily also from the interactive 3D netter anatomy, and other materials like textbook, like gray's anatomy, and netter flashcards.
Usually wiki is very useful.

 

[blissonearth]

Guys, can you help me with this ? I went to different sources and got different answers...

Which one forms the floor of carotid triangle ?

One source said : Omohyoid,
the others : thyrohyoideus, hyoglossus, and constrictors pharyngis medius and inferior.
Another one : Middle and lower pharyngeal constrictors (MPC & IPC)

Thanks!

 

[dr.internationa]

hi the answer is

thyrohyoid, hyoglossus and pharyngeal constrictors.

i says so in the decks too.

 

[dontist]

guys, can you help me with this ? I went to different sources and got different answers...

Which one forms the floor of carotid triangle ?

One source said : Omohyoid, - i think omohyoid is a muscle which demarcates boundry of triangles..not the floor.
the others : Thyrohyoideus, hyoglossus, and constrictors pharyngis medius and inferior. - correct answer.
another one : Middle and lower pharyngeal constrictors (mpc & ipc) - situated more posteriorly... Not possible for carotid triangle.

thanks!

correct me if wrong.

 

[adks19]

plz anyone interested in studyg biochem with me , its really tough confusing reply me here or at [email protected] thanx
all d best

 

[dr niki]

I have a few ques...which i haven understood at all..pls help me..

1}which of the foll 2ndary messengers is generated when phospholipase C is activated by the G alpha protein when it cleaves PIP2 ??

A) DAG & IP3
B) cGMP & cAMP
C) calmodulin & DAG
D) cAMP & DAG


2}Molecule not a precursor for gluconeogenesis??

A) pyruvate
B) Acetyl co enzyme A
C) lactate
D) glycerol
E) oxaloacetate


3} Pts plasma osmotic pressure= 29 mmhg
glomerular capillary press= 68 mmhg
hydrostatic press in bowmans capsule= 19mmhg
which of the foll. is pts net glomerular filtration press??

A) 10 mmhg
B) 20 mmhg
C)39 mmhg
D) 49 mmhg
E) 58 mmhg


pls give the answer with explanations..
thanks..

 

[blissonearth]

Friend of mine asked me to stop with lectures and reading books, start to memorize in an out the decks and asda exams booklet. Do you agree with this ? How long does it take to do these decks and booklets ? 2 months ? I am asking because I am only 2 months away, will be cut with 10 days cruise vacation with family in April. Suggestions will be accepted. Me, for he first time is so not looking forward for vacation with family

 

[happyk9]

Personally I think it is a very smart idea if you have systemically gone through all the reading material once.

Friend of mine asked me to stop with lectures and reading books, start to memorize in an out the decks and asda exams booklet. Do you agree with this ? How long does it take to do these decks and booklets ? 2 months ? I am asking because I am only 2 months away, will be cut with 10 days cruise vacation with family in April. Suggestions will be accepted. Me, for he first time is so not looking forward for vacation with family

 

[happyk9]

Here it is:

I have a few ques...which i haven understood at all..pls help me..

1}which of the foll 2ndary messengers is generated when phospholipase C is activated by the G alpha protein when it cleaves PIP2 ??

A) DAG & IP3-----answer
B) cGMP & cAMP
C) calmodulin & DAG
D) cAMP & DAG


2}Molecule not a precursor for gluconeogenesis??

A) pyruvate
B) Acetyl co enzyme A ---answer
C) lactate
D) glycerol
E) oxaloacetate


3} Pts plasma osmotic pressure= 29 mmhg
glomerular capillary press= 68 mmhg
hydrostatic press in bowmans capsule= 19mmhg
which of the foll. is pts net glomerular filtration press??

A) 10 mmhg
B) 20 mmhg---answer
C)39 mmhg
D) 49 mmhg
E) 58 mmhg


pls give the answer with explanations..
thanks..

 

[dr niki]

hey happyk9..

ur answers are correct!!
but can u pls explain the 1st n the 3rd one?
wer did u find the 1st one from? n hw to calculate the 3rd answer?

thanks alot...

 

[dontist]

can anyone give me answer for it?? I want EXPLANATION also....


and yes.. happyk9 i would also like to know the explanation of the previous answers... kindly pl tell us...

 

[doit22]

hi

can u post the explanations here on the thread pls....for ur biochem q....thanks.dr niki

 

[blissonearth]

can anyone give me answer for it?? I want EXPLANATION also....


and yes.. happyk9 i would also like to know the explanation of the previous answers... kindly pl tell us...

If I am not mistaken, should be number 2 is the answer. IF there is 3 answers willl be protoplasts, spheroplasts, and L-forms. Please correct me if I am wrong.

FOund this on the journal :
For more than 40 years microbiologists have known that bacteria with absent or defective cell walls could survive and even multiply. Such pleomorphic or spherical variants of bacteria have been commonly called protoplasts, spheroplasts, and L-forms. Although these terms have been used interchangeably, a more precise definition of each, based on the amounts of cell wall remaining and ability to reproduce, has been recently recommended. Cell-wall-defective bacterial variants can be produced in the laboratory by antibiotics such as penicillin or other agents which damage or inhibit the synthesis of the bacterial cell wall. Variants do not usually multiply on routine bacteriologic media but may reproduce if osmotically stabilized in hypertonic media enriched with serum. By use of such special media, wall-defective bacteria and fungi have been isolated from all types of clinical specimens (blood, spinal fluid, urine, pus, and tissues such as kidney and lymph node). The role which wall-defective variants play in human disease is not yet well defined. Animal studies suggest they are rarely pathogenic as a result of invasion and multiplication. However they can produce toxins and immunogens and can persist silently in a host, particularly one being treated with penicillin or related antibiotics, and later revert to the virulent parent. Thus it is possible that wall-defective variants produce disease via toxic or immune mechanisms or serve as persister forms of microorganisms in chronic and relapsing infections. Antibiotics directed against the metabolism of the cell or cell membrane of the etiologic agent, rather than against the synthesis of the cell wall, may sometimes control such infections.

 

[doit22]

Friend of mine asked me to stop with lectures and reading books, start to memorize in an out the decks and asda exams booklet. Do you agree with this ? How long does it take to do these decks and booklets ? 2 months ? I am asking because I am only 2 months away, will be cut with 10 days cruise vacation with family in April. Suggestions will be accepted. Me, for he first time is so not looking forward for vacation with family

hi

actually it depends ..if u can remember wat u hav seen in the videothn ur lucky..jus check this by doing a q paper in the subject which u hav done completely by video..thn u`ll knw wher u stand and hw to proceed...good luck

 

[godblessus]

Yep that's the correct answers : I too found in the journal here it goes:

Summary Spherical bodies resembling Weibull''s protoplasts are formed when certain bacteria (B. megatherium Salmonella gallinarum,B. mesentericus) are incubated with lysozyme or penicillin in the presence of 10% sucrose, as a stabilizer. The presence of mitotic figures in some of the protoplasts suggests that they are capable of development and regeneration.
TheS. gallinarum protoplasts showed some respiratory activity, although much less than the intact cells.B. megatherium protoplasts did not respire.

 

[godblessus]

can anyone give me answer for it?? I want EXPLANATION also....


and yes.. happyk9 i would also like to know the explanation of the previous answers... kindly pl tell us...

Where do u get this questions?

 

[dontist]

answer is correct.. Protoplast. thanks buddy.. that was good info...

 

[dontist]

 

[blissonearth]

Here it is:

I only can answer number 3 : GFR, number 1 and 2, I really have no idea, maybe when I read more I will get there.

If we disregard any oncotic pressure in the Bowman's capsule, we have in effect, three pressures to consider: glomerular hydrostatic pressure, glomerular oncotic pressure, and Bowman's capsule hydrostatic pressure. These can be expressed as a formula that will tell us the amount of hydrostatic pressure pushing fluid out of the glomerulus:


Net glomerular pressure equals:
Glomerular hydrostatic pressure minus [glomerular concotic pressure + Bowman's capsule hydrostatic pressure]


So 68 - (29+19) = 20mmHg


Glomerular hydrostatic pressure = capillary pressure.

 

[blissonearth]

answer is correct.. Protoplast. thanks buddy.. that was good info...

Ahhhhhhh....!!!! The power of internet. I feel lucky to be living at this era and taking the exam. I can't imagine flipping through textbooks pages after pages, looking for the answer

 

[blissonearth]

plz anyone interested in studyg biochem with me , its really tough confusing reply me here or at [email protected] thanx
all d best

You can join us here....

 

[blissonearth]

Is it 1 ? or 4 ? 4 is right in skin cancer due to the UV rays, when you remove, it comes back.

Anyone ?

 

[Truth seeker]

Ans: 5

 

[godblessus]

which of the following describes major effect of sickle cell anemia?

A. absence of biphosphoglcerate binding of Hb
B. Substitution of 2 proximal hisdine.
C. Decresed solubiity of deoxy form of Hb
D. A P50 valur for Hb similar to that of myoglobin
E. Decresed number of subunits in Hb

 

[blissonearth]

which of the following describes major effect of sickle cell anemia?

A. absence of biphosphoglcerate binding of Hb
B. Substitution of 2 proximal hisdine.
C. Decresed solubiity of deoxy form of Hb
D. A P50 valur for Hb similar to that of myoglobin
E. Decresed number of subunits in Hb

like any other anemia, it's C.

true ?

Sickle cells happens because of the glutamate is replaced by valine, makes the shape of the RBC sickle in shape