Renal System - Renal Function - Urinalysis: Urea, Creatinine, Ammonia and SG, Renal stones

Terminology
Renal System - the kidneys and urine formation and urination; synonymous with Urinary System
Urinary System - synonymous with Renal System
Genitourinary System - genitals (male, female) and urinary system

Renal System
The kidneys, ureters, urinary bladder and urethra form the renal system.
https://en.wikipedia.org/wiki/Urinary_system

Renal Profile
Also known as Renal Panel.
https://labtestsonline.org/understanding/analytes/renal-panel/tab/sample/

Renal Function
The Renal Function comprises tests that indicate the status of the kidneys. The kidneys have several functions.

Renal Function Tests (RFT)
Renal Function Tests (RFT) are a set of biochemical tests that determines the status of the kidneys.

Renal Section

Clinical laboratories have a separate section that handles urine specimens and their manual testing. It is called the Renal Section. It is also the smelliest section of any clinical lab if the urine samples are not disposed immediately after analysis or if the fumehood is not functioning properly.

Urinalysis
Urinalysis refers to the biochemical analysis of urine. It includes several tests, manual and automated.

Urine Dipstick Test 

A urine dipstick test is a simple means to determine certain chemical contents of urine (less the 5 minutes) using a dipstick. A dipstick is a plastic strip with many little patches or test pads. The dipstick is dipped in urine and excess urine is removed. The dipstick is left for a few minutes to let the colour reaction of the various pads to develop. The coloured test pads are then checked against the printed values on the cans the dipstick came in.

The urine dipstick test is demonstrated in class practicals and often appear in professional examinations. Students test 2 urine samples and are required to record the dipstick test values within 3-5 minutes.

The urine dipstick tests for Specific Gravity (SG) of urine, presence of glucose, protein, etc.

Not all urine tests can be done using the urine dipstick.

Many renal function tests are performed by automated chemistry analysers, using commercially available kits. These set of tests are known as Renal Function Tests (RFT) or Renal Profile.

Specific Gravity (SG)
https://en.wikipedia.org/wiki/Urine_specific_gravity

(i) High Urine SG

Hypersthenuria is urine with high SG, due to increased concentration of solutes in the urine. It occurs in dehydration, diarrhoea, emesis, excessive sweating, urinary tract/bladder infection, glucosuria, renal artery stenosis, hepatorenal syndrome, decreased blood flow to the kidney (especially as a result of heart failure), and excess of antidiuretic hormone caused by Syndrome of inappropriate antidiuretic hormone. 

• Frank dehydration SG >1.035  
• Neonates SG = 1.003
• Hypovolemia SG >1.015

(ii) Low Urine SG

Hyposthenuria is urine with low SG due to decreased concentration of solutes in urine. It occurs in renal failure, pyelonephritis,diabetes insipidus, acute tubular necrosis, interstitial nephritis, and excessive fluid intake (e.g., psychogenic polydipsia).

Osmolality

This is the amount of all dissolved solutes in urine. It is measured using a semi-automated osmometer, that uses freezing-point depression for determination of solutes, which is then correlated with osmolality. An example of an osmometer is the Gonotec Osmomat. Approximately 200 microlitres of urine is required for this test, which is placed in a thin-wall micro Eppendorf tube. It takes a few minutes to determine urine osmolality. Urine osmolality is expressed as milliosmoles/kg (mOsm/kg).

In healthy people, when osmolality in the blood becomes high, the body releases antidiuretic hormone (ADH). ADH causes the kidneys to reabsorb water, which results in more concentrated urine. The reabsorbed water dilutes the blood, and returns blood osmolality to normal.

Low blood osmolality suppresses ADH, and reduces the amount of water that the kidneys reabsorb. Blood osmolality increases towards normal. Dilute urine is passed to get rid of the excess water.

Creatinine

Creatinine is a waste product from muscle degradation (breakdown), from creatine. The more muscle is degraded (broken down), the higher the creatinine value in blood. Creatinine is cleared from blood by the kidneys. Healthy kidneys help to maintain creatinine at constant normal levels in the blood. However, during dehydration (during hot weather or reduced water intake), blood creatinine is elevated. Elevated creatinine can also indicate kidney failure or disease, as the kidneys cannot clear creatinine and creatinine levels thus build up in blood.

Creatinine clearance

The kidneys clear creatinine from blood. Blood creatinine is filtered and cleared, and appears as urine creatinine. Measuring the clearance of creatinine from the blood is a biochemical test of kidney function. Poor creatinine clearance means the kidneys cannot clear creatinine fast enough from the blood.

Ammonia

Most ammonia in the body forms when protein is broken down by bacteria in the intestines. The liver normally converts nitrogenous chemicals in the body (eg proteins) as ammonia. The liver too converts ammonia into urea. 

The normal liver removes the ammonium ions from proteins. These ammonium ions form urea via the urea cycle. 

(a) Urea cycle and elimination of ammonia as urea

The human body has a specific mechanism to prevent the build-up of ammonia in the bloodstream. Ammonia is converted to carbamoyl phosphate by the enzyme carbamoyl phosphate synthetase, and then enters the urea cycle to be either incorporated into amino acids or excreted in the urine.

Ammonia is excreted from the body as urea, which is eliminated in urine.

(b) Dietary effects of ammonia and urea
A high protein diet may lead to high ammonia levels in blood and high blood urea.

(c) Acidosis
In acid-base balance, the kidneys secrete ammonia to neutralize excess acid.

(d) Liver failure and ammonia toxicity
In liver failure, blood ammonium levels can rise and lead to ammonia toxicity, which affects the brain. This is critical in newborn babies who do not have a normal liver or normal liver enzymes.

Ammonia levels in the blood rise when the liver is unable to convert ammonia to urea. This may be caused by cirrhosis or severe hepatitis.

High levels of ammonia in the blood may be caused by:

• Liver disease, such as cirrhosis or hepatitis
• Reye syndrome
• Heart failure
• Kidney failure
• Severe bleeding from the stomach or intestines.

(e) Ammonia test
An ammonia test measures the amount of ammonia in the blood. 

Blood ammonia values:
   Adults 7–35 micromoles per liter (mcmol/L)

   Children 28–57 mcmol/L

   Newborns 64–107 mcmol/L

(f) Precautions

WARNING: Never mix ammonia with bleach (eg Clorox). This causes the release of toxic chlorine gas, which can be deadly.

Ammonia concentration and toxicity:

Household ammonia is a solution of NH3 in water (i.e., ammonium hydroxide). It is used as a general purpose cleaner for many surfaces. Because ammonia results in a relatively streak-free shine, one of its most common uses is to clean glass, porcelain and stainless steel. It is also frequently used for cleaning ovens and soaking items to loosen baked-on grime. Household ammonia ranges in concentration by weight from 5 to 10% ammonia.

Solubility of ammonia in water is 31% w/w (25 °C)

The toxicity of ammonia solutions does not usually cause problems for humans and other mammals.

Worker safety:

http://www.cdc.gov/niosh/topics/ammonia/

Urea
Urea is a waste product which is excreted in urine. Urea is less toxic compared to ammonia, its precursor.

External links

http://www.medicinenet.com/creatinine_blood_test/article.htm

http://www.webmd.com/a-to-z-guides/creatinine-and-creatinine-clearance?page=3

http://www.medicinenet.com/kidney_stone_pictures_slideshow/article.htm
http://www.stylecraze.com/articles/serious-side-effects-of-lemon/?ref=ka
http://www.nlm.nih.gov/medlineplus/ency/article/003463.htm
http://www.webmd.com/digestive-disorders/ammonia-test
https://en.wikipedia.org/wiki/Ammonia
http://www.pilotfriend.com/aeromed/medical/kidney.htm

Magnesium Deficiency

Magnesium is measured along with sodium, potassium, and chloride for Anion Gap analysis, However, approx. 1% magnesium is found in blood.

Magnesium deficiency closely mimics diabetes. Signs and symptoms of magnesium deficiency also leads to heart problems including chest tightness,

Other signs and symptoms of magnesium deficiency include cramps, fatigue, thirst and weight loss problems.


External links

http://www.healthyfoodhouse.com/magnesium-deficiency-these-are-the-symptoms/

3D Printing for Reconstructive Surgery

So far we have heard of 3D printing for constructing parts of the body as aids in surgery. They have been used in 2 successful surgeries in toddlers.

One case was the separation of a Siamese twins. The conjoined twins were successfully separated in a 26-hour surgery. They are Hope and Faith (Knatalye Hope Mata and Adeline Faith Mata). Surgery was done at the Texas Children's Hospital.
http://www.medicaldaily.com/pulse/conjoined-twins-separated-doctors-disjoin-major-organs-26-hour-operation-separate-323152


A second case was the re-construction of the face of a toddler named Violet. Violet was born earlier than her twin sister who has a normal face. Violet's eyes are set far apart. She has Tessier facial cleft. The surgery aimed to give her a better face. Surgery was done at the Boston Children's Hospital.
http://www.medicaldaily.com/pulse/girl-tessier-facial-cleft-undergoes-3d-printing-surgery-reconstruct-face-319960

Dexamethasone

We live in a society today, where food comes fast and easy. We eat whatever we fancy. We salivate whenever we smell food, even though it is just ikan masin goreng. We eat all the time, regardless of whether we are full or not. We eat whenever food is offered, even at the workplace and at social family gatherings or at our friends' homes. Food is everywhere. How much food can we really consume? Quite a lot.

What happens when we eat a lot of food? We add on flesh and fat to our bones. We tend to eat lots of protein - beef, lamb, chicken and fish. We can't do without protein. 

What happens when we eat lots of animal protein? Protein comes from cells. Cells contain nuclei. Nuclei are a source of purines and pyrimidines. Breakdown of cells means breakdown of purines. Purines breakdown to give uric acid. We tend to get a lot of uric acid made in our body. Where does this uric acid go?

Uric acid is soluble in water, and thus, it is soluble in blood. It travels in the blood to the kidney where it is removed in urine. The more we drink water, the easier it is to remove uric acid from the body, and prevent   it from building up in the body.

If we don't drink sufficient water, then uric acid can't be removed easily via urine. It stays in the body and gets deposited in our joints - hands, knees and feet. 

What happens next? If too much uric acid gets deposited in the tissues, it can begin to crystallize. That means it can form crystals. 

What do uric acid crystals look like?  Sharp long spindles. What can these uric acid crystals do? They can start to poke the surrounding tissues, causing pain and inflammation. 

When do we start to feel pain due to uric acid crystals in our joints? At about age 40 to 50 years. But it can be earlier in some people and later in others. 

What is this condition called? It is known as gout. Some people spell it as gaut - just as they would pronounce it.

What is gout? It is a terrible condition which gives excruciating pain in the joints. The sufferers can't kneel or perform Muslim prayers as they cannot bend their knees to do sujud or sit in between sujud. They can't bend their knees. They can't get up easily from sitting position. Life is full of pain in the joints. They can't walk far or go travelling.

What medication can gout sufferers seek? A quick visit to the local shop is all they need to do for a start. There are many local preparations that claim to help ease gouty pain in the knees, knuckles and toes.

A better thing to do is to go to hospital and see a good doctor who really cares. Doctors start treating gout when the uric acid level is very high, when it exceeds 600 uM or 600 µmol/L. High levels of uric acid in the blood is referred to as hyperuricemia.

Is hyperuricemia, gout and joint pain treatable? Yes, but it will take a long time to remove all the uric acid crystals from the tissues if the sufferer does not drink plenty of plain water. Plain water does a good job in removing uric acid from the joints, and alleviates pain. Taking medications will then expedite uric acid removal and the joint pain disappears.

The drug Allopurinol maybe prescribed to reduce blood uric acid levels. However, not everybody wants to go to see a doctor for a medicine to treat their gout problem. Many still prefer traditional preparations. One such prep is sold locally, but has recently been banned by the health authority in Malaysia. 

This particular traditional prep (pic above) is meant for gout, and contains the controlled drug, dexamethasone. Free and long-term use of dexamethasone is dangerous to health.

What is dexamethasone? It is a corticosteroid. It relieves inflammation, but at the same time, reduces the body's defense system. Not everyone can tolerate dexamethasone, and for long-term use. Some experience weight gain and sleep disturbance. They can begin to develop some other conditions, including hirsutism (hairy) and Cushing's Syndrome (moon face and with a mound on the cape). So it is best not to take any gout medication until you have seen a doctor at the nearest hospital near you.

Dexamethasone is used to treat arthritis, skin, eye and kidney disease, asthma and some cancers.

External links:
http://buletinharian.com/2-produk-konon-dari-madinah-dikesan-mudarat-kesihatan.html

http://www.nlm.nih.gov/medlineplus/ency/article/000422.htm

http://www.nlm.nih.gov/medlineplus/druginfo/meds/a682792.html

http://www.webmd.com/drugs/2/drug-1027-5021/dexamethasone-oral/dexamethasone-oral/details
http://en.wikipedia.org/wiki/Uric_acid