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2006-05-28T22:34:00.000+03:00

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Medical Contributers Needed

2005-12-22T19:44:00.000+02:00

If you work or study in a medical field; clinical or academical, you can contribute with me in expanding this free medical website, by sending articles, pictures, and tips, etc...

The Rules:

You must be either working or studying in a pure medical field. Medical journals employees, for instance, are not allowed to contribute here.
If you'd be sending articles, each article must not be more than 2,500 letters long.
Pictures or photos must be high in quality, clear, not under copyright , and not smaller than: 400 x 300 pixels.
The content of the articles must not be comprehensive, right out of an atlas, very common, repetitive, irrelevant, or insignifact. The recommended sort of content should be summarized in a few points, and should contain one or more of the following:
tips, tricks, important uncommon points, common clinical misconceptions, demonstrating illustrations, rare actual photos. See the posts in here for examples.
Once you contribute with at least one post, your info will permanently be placed in the sidebar (read more below).

What will you gain?

I will give no cash. However, you'll gain other profitable advantages:

A link, or an image linking to your website will be added to the sidebar. (see examples on right-hand side)
Under each contribution of yours, your name, website, and email will be added.
Each month, one of the contributers will be featured in a dedicated post, with his CSV and, his personal/contact info, and his website information. (p.s. contributers joined earlier will be presented earlier).

Consequently, you'll gain a considerable amount of self-advertisements and forwards in my website. And by contributing more, your info appears more.

Contact me:

My email -- please use the subject: Medical Contributers

The Residency War - AMGs vs FMGs

2005-12-19T01:32:00.000+02:00

Miscellaneous > USMLE > Residency

Well, I've read that sentence in a website a couple of months ago (..don't remember the URL). So they say it's getting even harder for a foreign medical graduate (FMG) to get a residency in the United States. That may lead to sending the foreign doctors to remote places, like rural areas,..etc.

Racism? mm,.. I think it's like "Yes and No" at the same time.

Why "No" ?
Rationally, people of a certain country has given a lot to their country throughout their life. They've grown in it, and are more able to cope with most of the circumstances that occur. Whether it's social, cultural, or economic, native people are more aware and more familiar of what to think, and what do about it. That's unlike the case with a foreign person, who in most of the cases is not that oriented with the country he's going to live in. That was generally speaking..

Now let's come to the medical part. The USMLE exam requires a specific way of thinking; an intelligent, concise, and more importantly 'clinical'. American medical students study medicine that way in their medical schools, so they automatically graduate with minds that we can call: "American Medical Minds". On the contrary, the majority of the FMGs applying to the USMLE come from developing countries (statistics) whose medical schools lack of any sort of appropriate, or sufficient way of teaching. The lecturers are way too narrow-minded; there are only very few, or no modern equipments available for the student; there are 'too' many medical students that sometimes a single grade includes over 900-1000 students, and a single practical section may include over 80 students.

I think it's very fair to say that the native American MGs are worthy of residencies more than FMGs are. Even the statistics show that over 90% of the AMGs pass the USMLE exam, in comparison to only 50% for the FMGs.

Why "Yes" ?
I think it's very unfair that FMGs need 'more' marks in the USMLE to get residencies for certain specifications, like surgery. It would've been a lot more fair for the USMLE to be equally applied upon all the takers, regardless of their ethnicity. Normally, most of the FMGs do not pass the USMLE (like I said above. The percentage is 50). Now it became even harder, as for instance, scoring a 150 is equivalent to an AMG scoring a 100! Sometimes AMGs get better residencies though they score less than FMGs in a certain exam. This is totally unfair!

What do you all think?

Heart valves disorders and Heart failure, others

2005-12-16T19:18:00.000+02:00

Pathology > Cardiovascular diseases

I'll talk about the most common valvular disorders with respect to heart failure, those of which are:

:: Mitral valve (stenosis and incompetence)
:: Aortic valve (stenosis and incompetence)

P.S. all the above disorders cause total heart failure (Lt. & Rt.-sided) except Mitral stenosis which causes right-sided heart failure only.

Mitral stenosis

caused mainly by: rheumatic valvulitis, or senile calcification
causes accumulation of blood in the left atrium --> hypertrophy and dilatation --> pulmonary venous congestion --> pressure extends to the pulmonary arterial system --> pulmonary arterial hypertension --> right-sided heart failure

Aortic stenosis

caused mainly by: rheumatic valvulitis, or senile calcification
causes accumulation of blood in the left ventricle --> hypertrophy, dilatation, insufficiency --> left-sided heart failure
consequently, accumulation of blood in the left atria (because the lt. ventricle is full) --> hypertrophy and dilatation --> pulmonary venous congestion --> pressure extends to the pulmonary arterial system --> pulmonary arterial hypertension --> right-sided heart failure (late)
Angina Pectoris during either systole or diastole as the coronary filling is insufficient in both cases (see Angina Pectoris due to Aortic incompetence)

Mitral incompetence

caused mainly by: rheumatic valvulitis, or functionally by force-stretching due to acc. high blood pressure in the left ventricle in left-sided heart failure (see fig. below)
causes regurgitation of blood from Lt. ventr. to Lt. atrium during systole, and accumulation of blood in both of them during diastole --> Lt. ventricular insufficiency and pulmonary venous congestion --> Left and right sided heart failure

Aortic incompetence

caused mainly by: rheumatic valvulitis, or functionally by force-stretching due to acc. high blood pressure in the left ventricle in left-sided heart failure (see fig. below)
causes regurgitation of blood into Lt. ventr. during diastole (low diastolic pressure), and over-emission of blood during systole (high systolic pressure) --> Waterhammer's pulse
Regurgitation also causes accumulation of blood in Lt. ventricle, then Lt. atrium --> Lt. ventricular insufficiency and pulmonary venous congestion --> Left and right sided heart failure
Angina Pectoris during diastole only (theoritically) as the coronary filling is insufficient in that case (see Angina Pectoris due to Aortic stenosis)

Aspirin Toxicity: Acute vs Chronic; Respiratory acidosis/alkalosis

2005-12-14T01:31:00.000+02:00

Pharmacology > Drug toxicity

Acute Aspirin Toxicity:

Uncompensated Respiratory Acidosis
Cause: Huge amout of Aspirin causes medullary inhibition --> Hypoventilaion --> increase of Serum CO2 --> respiratory acidosis
Moreover, the kidneys are normally excreting bicarbonate products (alkali in nature) --> more acidosis (metabolic now).
This leads to severe uncompensated acidosis

Chronic Aspirin Toxicity:

Compensated Respiratory Alkalosis
Cause: Mild accumulation of Aspirin over time causes medullary stimulation > hyperpnea --> excretion of more CO2 --> decrease of Serum CO2 --> respiratory alkalosis
However, the kidneys are normally excreting bicarbonate products (alkali in nature) --> neutralization of the present alkalosis (compensation) --> pH back to normal

Indications of Diuretics in Hypertension

2005-12-02T02:04:00.000+02:00

Pharmacology > Drugs

Well, there are a lot of drugs that may be used in hypertension. On the other hand, there are a lot of hypertension conditions that may be combined with other defects. So which is the right drug for the right case?

Initial hypertension / combined drug

Mostly, a mild hypertension diagnosed for the first time requires a mild temporary treatment in order to assess the situation before further treament is given. In this case, thiazide diuretics, as chlorothiazide are chosen.

Sudden Severe hypertension (emergency)

In this case, a very potent fast-acting drug is needed, such as Furosemide, a loop-acting diuretic.

Hypertension with Renal failure

Using diuretics in renal failure may be risky and life-threatening as much water and nutrients are lost. For that, Furosemide too, may be used. In fact, Furosemide manages hypertension mainly by its potent venodilator effect, even before any change in the urinary output occurs.

Hypertension due to hyperaldosteronism /or with hypokameia / or Diabetis Melletus /or Gout

Potassium-sparing diuretics, as Amiloride are used in such case. These drugs act by antagonizing the release, and action of Aldosterone, thus relief of water and sodium retension occurs.

Plus, they decrease the secretion of Potassium in the distal convoluted tubules, thus preventing hypokalemia that occurs with other diuretics.

They do not affect the release of insulin secretion (from the Pancreas) unlike most of the other diuretics that decrease it --> Worsening DM. That makes them the most favorable in the cases of DM.

They, as well do not affect the secretion of uric acid (in Prox. conv. tubule) unlike most of the other diuretics that decrease it a lot --> uric acid precipiation. The reason is simply because the potassium-sparing diuretics do not act at the PCT (the site of uric acid secretion). That makes them the most favorable in the cases of Gout.

Classification of Tumors + Notes & Tips

2005-11-29T23:47:00.000+02:00

Pathology > Cell growth disturbances > Classifications

Full classification of tumors.. click on the image below to enlarge it.

Notes & Tips about tumors:

Generally, the suffix (-oma) refers to Neoplasm. However, sometimes it refers to non-neoplastic conditions, such as Hematoma (swelling).
Carcinoma in-situ is not equivalent to locally malignant tumors. The latter never metastatizes, while the former is an early stage of a neoplasm that may metastatize.
Infiltration (Invasion) is not equivalent to Expansion. The former moves vertically, while the latter moves horizontally.
The word "Sarcoma" originates from the latin word, Sarcos (fish flesh), as the specimen looks like such flesh (one plain non-streaking piece).
In most cases, carcinomas spread through the lymphatics. However, a few types spread through blood, some of which are: Cancer thyroid, breast, renal cell, lung, SRG, and placenta.

Dermatomes of the Arm, Chest and Forearm

2005-11-29T01:50:00.000+02:00

Anatomy > Surface anatomy

P.S. The images are clickable. Click them to view the full-size versions.

Dermatomes of the Arm, and part of the Forearm :-

Dermatomes of the Arm, and part of the chest (another view) :-

Dermatomes of the Forearm, hand, and part of the Arm :-

Renal physiology and diuretics

2005-11-25T21:03:00.000+02:00

Physiology, Pharmacology

The image below contains all the info you need about the renal physiology as to what substances are absorbed/secreted allover the different segments of the renal tubules. Plus, you get to see the types of different diuretics working on each segment. Below the image there is all this in a text format.

Click on image to enlarge it. P.S. version 2

Proximal convoluted tubule (PCT)

Working diuretics: osmotic e.g. Mannitol

Reabsorption of:

Sodium (67%)
Chloride (40%)
Potassium (all)
Water (equiosmotic amount)
HCO3 ions (85%)
Glucose, AA (all)

Secretion of:

Creatinine
Uric acid
Antibiotics
Some diuretics

Henle Loop

Working diuretics: Loop e.g. Furosemide

Reabsorption of:

Sodium Chloride (25%)
Potassium [desc. limb only]
Water (equiosmotic amount) [desc. limb only]
Magnesium
Calcium

Secretion of:

No secretion occurs at this segment

Distal convoluted tubule (DCT)

Working diuretics: thiazides e.g. Chlorothiazide [proximal part] - osmotic e.g. Mannitol, Pottasium sparing e.g. Amiloride [distal part]

Reabsorption of:

Sodium Chloride (proximal part 10% - distal part 2-5% "under the effect of Aldosterone")
Water (equiosmotic amount) [distal part only] "under the effect of Aldosterone"
Calcium [proximal part only] "under the effect of parathyroid hormone"
Ammonia [distal part only]

Secretion of: [distal part only]

Potassium
Hydrogen

Collecting duct and tubules (medullary part)

Working diuretics: osmotic e.g. Mannitol

Reabsorption of:

Water "under the effect of Anti-diuretic hormone"

Secretion of:

No secretion occurs at this segment

Expect Posting Delays

2005-11-25T15:30:00.000+02:00

Announcement

I guess I'll be posting less from now on till I finish my mid-year exams after 2 months, roughly. As you know, Medicopedia is not an ordinary medical website or a journal. I don't post medical news or information taken from other websites or magazines. I post my own study notes and walk-throughs. Moreover, I work on the website design, and I draw images for the website, alone too. So please bear me out, and spread the word about the website.

Many thanks :)

Heart failure & Venous congestion

2005-11-24T17:35:00.000+02:00

Physiology, Pathology > Cardiovascular

I'll try to show the connection between heart failure and venous congestion. Which causes the other? Which starts first? and which case is exaggerated by the other?

Let's assume that heart failure started. Mostly what happens is as follows:

Heart failure occurs i.e. it's is unable to pump blood sufficiently/efficiently (cause?: numerous)
Blood accumulates in the ventricles, and consequently in the atria
The venous return coming through the pulmonary veins and the vena cavae is opposed by a great pressure at the atria
The venous pressure increases --> venous congestion (pulmonary or systemic)
The work of the heart increases --> ventricular hypertrophy

So we can deduce that venous congestion is a result of heart failure, and not vice versa. However, a state of venous congestion may worsen the already present heart failure. We can see too that ventricular hypertrophy occurs in most cases of heart failure.

Stedman's Medical Dictionary, 27th Edition

2005-11-23T01:20:00.000+02:00

Miscellaneous

I own a PalmOne Tungsten E2, and I've managed to get a copy of this fabulous medical dictionary on it, Stedman's Medical Dictionary, 27th Edition. It's probably the most complete medical dictionary so far. More than 102,000 medical terms are defined in it. The veiwer makes it very easy to access, with options like: previous word, next word, history, add note, filter search,...etc

I think it's most suitable for undergraduate and recently graduated students. Won't be enough for specialists, I think. One con is that some terms are collected within a more general term (e.g. When you search for "Klinefelter syndrome", you find it in the search list, but when you tap on it, you get the "Syndrome" page instead. You then have to scroll manually through a list of ALL syndromes to "Klinefelter syndrome". Pretty annoying if you ask me, but.. The 'instructions' section says this is due to storage limitations.

Give it a try if you own a Palm handheld. But beware, it consumes upto 16mB of storage, so make sure you got an external memory card with plenty of storage. Here is the website.

Neoplasm, Hamartoma, Teratoma, Hyperplasia

2005-11-23T01:12:00.000+02:00

Pathology > Cell growth disturbances

All of those conditions are types of different cell growth disturbances. In this article, I'll only try to mention the main tricky differences between them.

Neoplasm

local growth, but may spread (direct invasion, or metastasis)
of a monoclonal origin
may or may not resemble the tissue of origin
its growth is uncoordinated & uncontrolled even if the cause or the original tissue growth stops
subtypes: Benign, Malignant, Locally malignant

Hamartoma

resembles Neoplasm (grossly & microscopically)
local coordinated growth
controlled i.e. stops its growth if the cause or the original tissue growth stops
e.g. hemangioma, lymphangioma

Teratoma

non-local/foreign -- arises from other tissues
is actually a neoplasm
common targets: ovaries - testis

Hyperplasia

is of a polyclonal origin
not as risky as neoplasm
occurs due to physiological factors (female breast at puberty) or pathological factors (hormonal hypersensitivity)

Loop Diuretics vs Thiazide Diuretics

2005-11-22T23:22:00.000+02:00

Pharmacology > Drug Uses --- Notes: [+] increase, [-] decrease

So both types of drugs are used for curing hypertension and/or edema, but when to use this and when to use that?

Loop diuretics (e.g. furosemide)

Used in acute hypertension (emergency cases)
How: by the potent hypovolemic (diuretic) effect. Furosemide is specifically used in hypertension with renal dysfunction due to its potent venodilator effect which manages hypertenion before a considerable urinary output change occurs.
Mainly in Pulmonary venous congestion
How: flurosemide has a very potent venodilator effect especially at the pulmonary area.

Thiazide diuretics (e.g. chlorothiazide, hydrochlorothiazide)

Used in essential chronic hypertension
How: By:
1. [-] the peripheral resistance (either direct or indirect).
2. the induced diuretic (hypovolemic) effect causes reflex [-] cardiac output.
Net result: [-] hypertension --> BP back to normal.
Used in most of the cases of edema, more commonly extra-pulmonary.
How: the diuretic effect: causes [-] Na reabsorbtion --> [-] water reabsorption --> [+] pulling of water from tissues to be excreted --> [-] ECF fluid content.

Tachycardia vs Palpitation

2005-11-21T21:29:00.000+02:00

Physiology > Cardiovascular > Tips

What's the difference between those terms; tachycardia & palpitation?
well, some students misuse the term 'palpitation' and refer it to a condition of 'tachycardia'. In fact, Tachycardia is the situation where the heart beats are increased, while Palpitation is the situation where the heart beats (which may be normal, increased "Tachycardia", or decreased "Bradycardia") is felt by the patient through his chest.

In other words, Tachycardia (or Bradycardia) refers to the number of heart beats, whereas Palpitation refers to feeling of those beats (which in any case is abnormal, except in marked sympathetic activity i.e. Fight, Flight, and Fright).

WEBSITE UNDER CONSTRUCTION

2005-07-30T06:19:00.000+03:00

This website is currently under heavy construction.
Kindly add it to your favorites [you can use the link on the right] -- and visit us soon.

Thanks a lot