Renal colic, the excruciating pain caused by a stone passing down the urinary tract is well known in all countries. The pain stops when the stone is passed naturally or removed by a surgeon. A patient may never have another attack or attacks may recur at irregular & sometimes long intervals. Most stones remain in the kidney where they often produce no symptom & are therefore known as SILENT STONES.
CHEMISTRY OF RENAL CALCULI:
Renal calculi are composed of different types of crystals however mostly renal stones are composed of Calcium Oxalate, Calcium Phosphate, Uric acid, Cystine & Magnesium Ammonium Phosphate crystals.
TYPES OF STONES:
1) CALCIUM STONES : Most of the stones are generally composed of Calcium Oxalate & Calcium Phosphate crystals but Calcium Oxalate stones are more common than Calcium Phosphate stones .The factors that promote the precipitation of Calcium Oxalate & Calcium Phosphate crystals in the urine are as follows ,
a) Hypercalciuria: Hypercalciuria is defied as a daily urinary excretion of calcium above 300 mg in men & 250 mg in women .Hypercalciuria is further classified as Idiopathic & Secondary Hypercalciuria. In Idiopathic hypercalciuria due to unknown reason there is increased intestinal absorption of calcium also there is decreased renal calcium reabsorption & there is increased bone resorption.
Hyperparathyroidism, Sarcoidosis, excessive production of vitamin D, immobilization, medullary sponge kidneys & excessive consumption of Calcium are some of the factors that are responsible for Secondary Hypercalciuria. Hypercalciuria is associated with an increased incidence of stone formation.
b) Hyperoxaluria: Refers to excess of Oxalate in urine .The greater part of the oxalate excreted in the urine is of endogenous origin & often comes from tissue metabolism of Glycine .Excessive intake of Vitamin C also causes hyperoxaluria .The commonest cause of hyperoxaluria is gastrointestinal malabsorption of dietary oxalates. Fatty acid malabsorption leads to calcium binding in the gut to produce calcium soaps of the fatty acids. This leaves the oxalate free & unbound to be absorbed. Enteric hyperoxaluria is exaggerated by a diet low in calcium.
C) Absence of stone forming inhibitors in urine: Substances which inhibit crystal growth are also present in urine. These include citrate, pyrophosphate, nephrocalin, glycosoaminoglycans. Absence of these inhibitors promotes stone formation.
2) URIC ACID STONES : About a quarter of patients with uric acid stones have hyperuricosuria with or without hyperuricemia & in most cases excessive dietary intake of Purine rich foods like liver , kidney sardines , brains etc causes hyperuricosuria . Uric acid is end product of Purine metabolism. Increased level of uric acid in urine causes decrease in pH of urine as a result urine becomes more acidic resulting in uric acid precipitation. Uric acid stones are also associated with acid/base metabolism disorders where the urine is excessively acidic.
3) CYSTINE STONES: Cystinuria is due to an inborn error of metabolism .The renal tubules fail to reabsorb the amino acids Cystine, Lysine, Arginine & Ornithine. These pass in large amounts in urine, where Cystine the least soluble amino acid tends to precipitate out & form stones.
4) STRUVITE STONES (Magnesium Ammonium Phosphate): Also known as infectious stones & Triple phosphate stones are formed due to bacteria Proteus mirabilis (but also Klebsiella, Serratia, and Providencia species) which split urea to ammonia with the help of urease as a result of which urine pH becomes alkaline & leading to stone formation.
5 ) XANTHINE STONES : Are composed of Xanthine
These stones are extremely uncommon and usually occur as a result of a rare genetic disorder.
DIETARY MANAGEMENT:
Depends upon the type of stone & conditions that are responsible for stone formation.
1) Calcium Oxalate Stones :
Particular emphasis should be directed at the calcium & oxalate content of the diet as an excess of both these nutrients has been associated with the formation of stones. If the stones formation is due to hypercalciuria than a diet low in calcium should be taken also a high fiber diet should be encouraged to reduce calcium absorption. Antacids containing calcium should be avoided .Protein & Sodium intake should not be in excess as both increases urinary excretion of calcium.
If the stone formation is due to hyperoxalicuria than a diet high in calcium should be encouraged as calcium will form insoluble complexes with oxalic acid in gut & it will be excreted out of the body in the stools .Also foods rich in Oxalic acid should be avoided
OXALIC ACID CONTENT OF SOME FOODS
1) CEREAL – BAJRA -21mgs/100 gms
2) PULSE - HORSE GRAM – 417mgs / 100 gms
3) LEAFY VEGETABLES –AMARANTH -772 mgs / 100 gms
- SPINACH – 658 mgs / 100 gms
- RHUBARB –is also rich source of Oxalic acid
4) OTHER VEGETABLES - DRUMSTICKS -101mgs /100 gms
5) NUTS – ALMOND – 407 mgs / 100 gms
6) FRUITS – AMLA – 296 mgs /100 gms
Excessive intake of Vitamin C should be avoided as Vitamin C is metabolized & oxalic acid is formed. Fat mal absorption should be treated in order to prevent formation fatty acid & calcium soaps in intestine. Excessive intake of proteins & sodium should be prevented as both increases urinary excretion of calcium & in turn promotes calcium binding with oxalic acid in urine. The intake of water should be increased around 3000 ml of fluid should be taken daily. Stone inhibitors like citrates should be taken to prevent stone formation in urine.
2) Uric acid stones:
Excessive intake of purine rich foods like liver, brain, Sardine etc should be avoided. Also water consumption should be increased & alcohol intake should be restricted. Generally an ALKALINE ASH DIET is recommended since it will help in reducing the acidity of urine by increasing the pH of urine.
An Alkaline Ash Diet consists mainly of fruits , vegetables & milk with little meat , fish , eggs , cheese & cereals , that when catabolized leaves an alkaline residue to be excreted by urine .Alkaline Ash diet includes mostly all vegetables .Among fruits lemon , lime , watermelon , grape fruit , tomato , Avocado etc.
3) Struvite stones :
In case of Struvite stones water should be taken in excess also antibacterial medicines should be taken to destroy bacteria in urine & an ACID ASH DIET is recommended.
An Acid Ash Diet is a diet which mainly comprises of meat, fish, eggs & cereals & consist of no or minimal amounts of fruits, vegetables & milk & it gives acid residue to be excreted in urine when catabolized in the body . Acid Ash diet will make the urine acidic & there by prevent stones formation
Friday, February 13, 2009
Wednesday, February 4, 2009
CORTICOSTEROIDS & ADRENAL DIABETES
The Adrenal Glands are composed of two distinct parts, the adrenal medulla & the adrenal cortex. The Adrenal medulla secretes two hormones EPINEPHRINE & NOREPINEPHRINE in response to sympathetic stimulation. The Adrenal cortex secretes an entirely different group of hormones called CORTICOSTEROIDS .There are two types of Corticosteroids 1) MINERALOCORTICOIDS & 2) GLUCOCORTICOIDS .Both , Glucocorticoids & Mineralocorticoids are steroid compounds
MINERALOCORTICOIDS: The Mineralocorticoids have gained this name because they especially affect electrolytes of the extra cellular fluids (SODIUM & POTASSIUM) .Below are names of some important mineralocorticoids
1) Aldosterone: It is very potent & accounts for 95% or more of Mineralocorticoid activity .It is secreted by ZONA GLOMERULOSA which is the outer most layer of Adrenal cortex.
2) Desoxycorticosterone: Is 1/15th as potent as Aldosterone & secreted in very small quantities.
3) Corticosterone : Has very slight activity
4) 9alpha –Flurocortisol: It is synthetic & has slightly more potent than Aldosterone.
5) Cortisol: Has very slight mineralocorticoid activity.
6) Cortisone: Is synthetic & has very slight activity.
GLUCOCORTICOIDS: The Glucocoricoids have gained their name because they exhibit an important effect in increasing blood Glucose concentration. They also affect Protein & fat metabolism. Below are names of some important glucocorticoids
1) Cortisol: Very potent & accounts for about 95% of all
Glucocorticoid activity .It is secreted by The ZONA FASCICULATA which is the middle layer of Adrenal cortex & the deepest layer – ZONA RETICULARIS.
2) Corticosterone: About 4 % of total glucocorticoid activity but much less potent than Cortisol.
3) Cortisone: Synthetic but as potent as Cortisol.
4) Prednisone: Synthetic but 4 times as potent as Cortisol.
5) Methylprednisone: Synthetic but 5 times as potent as Cortisol.
6) Dexamethasone: Synthetic but 30 times as potent as Cortisol.
**** It is clear from the above list that some of these hormones have both Glucocorticoid & Mineralocorticoid activities.
The level of Cortisol needs to be just right. Too much or too little can cause problems. The amount of Cortisol which is made in the adrenal glands is controlled by another hormone called Adreno-cortico-trophic hormone, or ACTH for short (and sometimes just called Corticotrophin). ACTH is made in the pituitary gland.
The pituitary gland lies just below the brain. It makes several hormones, including ACTH. The amount of ACTH made by the pituitary gland is largely controlled by another hormone called Corticotrophin releasing hormone (CRH). CRH is made in a small part of the brain called the hypothalamus, which is just above the pituitary gland. CRH 'stimulates' certain cells in the pituitary to make ACTH.
ACTH passes into the bloodstream, is carried to the adrenal glands, and 'stimulates' the adrenal gland to make Cortisol. If the level of ACTH increases in the bloodstream, the adrenals make more cortisol.But, Cortisol has a negative 'feedback' effect on the pituitary gland. As the level of Cortisol in the bloodstream rises above a certain level, it 'turns down' the amount of ACTH made by the pituitary. This means the adrenal is then stimulated less, and less Cortisol is made. So, the level of Cortisol is kept within a certain range - just enough as is needed by the body.
MAJOR FUNCTION OF GLUCOCORTICOIDS :
By far the best known metabolic effect of Cortisol & other glucocorticoids on metabolism is their ability to stimulate Gluconeogenesis ( a metabolic process in which glucose is formed from non-carbohydrate carbon substrates such as lactate , glycerol , and glucogenic amino acids by the liver ) . Cortisol often increases the rate of gluconeogenisis as much as six to ten folds. Cortisol causes gluconeogenesis by increasing all the enzymes in the liver cell which are required to convert amino acids to glucose. Also Cortisol causes mobilization of amino acids from the extra hepatic tissues ( mainly muscles ) .As a result more amino acids become available in the plasma to enter into the gluconeogenisis process of the liver & thereby to promote the formation of glucose .Not only this Cortisol causes a moderate decrease in the rate of glucose utilization by the cells every where in the body .
ADRENAL DIABETES:
Excessive production of Cortisol leads to ADRENAL DIABETES Adrenal Diabetes has many similarities with Pancreatic Diabetes. In Adrenal Diabetes the blood Glucose concentration is 50 % or more above normal levels. Administration of Insulin lowers the blood glucose concentration only to a moderate amount .Therefore it said that Adrenal Diabetes is moderately sensitive to Insulin.
CAUSES OF EXCESSIVE PRODUCTION OF CORTISOL:
1) Non Cancerous tumor of Pituitary Gland (Pituitary Adenoma). In this condition the Pituitary gland produces more ACTH (CORTICOTROPHIN) which stimulates the Adrenal gland to produce more Cortisol & the abnormal cells in the adenoma are not 'turned down' by feedback from the high levels of cortisol.
2) Non Cancerous or malignant tumor of Adrenal gland causes excessive production of Cortisol.
3) Hyperplasia of Adrenal gland also leads to more production of Cortisol.
4) Some malignant & non cancerous tumors in other parts of body sometimes cause excessive production of Cortisol by producing ectopic ACTH. ACTH is a hormone which stimulates the Adrenal glands to produce Cortisol. Normally ACTH is produced by Pituitary gland. However some rare tumors like that of Lung cancer produce ectopic ACTH which stimulates the Adrenals to produce Cortisol
5) Excessive intake of Alcohol also increases Cortisol levels.
6) Depression is also responsible for higher production of Cortisol.
TREATMENT:
Depends upon the cause of excessive production of Cortisol. If it is due to excessive intake of Alcohol than avoidance of alcohol will cure Adrenal diabetes. If it is due to tumor of Pituitary or Adrenal gland or other part of body than removal of tumor will cure the Diabetes.
MINERALOCORTICOIDS: The Mineralocorticoids have gained this name because they especially affect electrolytes of the extra cellular fluids (SODIUM & POTASSIUM) .Below are names of some important mineralocorticoids
1) Aldosterone: It is very potent & accounts for 95% or more of Mineralocorticoid activity .It is secreted by ZONA GLOMERULOSA which is the outer most layer of Adrenal cortex.
2) Desoxycorticosterone: Is 1/15th as potent as Aldosterone & secreted in very small quantities.
3) Corticosterone : Has very slight activity
4) 9alpha –Flurocortisol: It is synthetic & has slightly more potent than Aldosterone.
5) Cortisol: Has very slight mineralocorticoid activity.
6) Cortisone: Is synthetic & has very slight activity.
GLUCOCORTICOIDS: The Glucocoricoids have gained their name because they exhibit an important effect in increasing blood Glucose concentration. They also affect Protein & fat metabolism. Below are names of some important glucocorticoids
1) Cortisol: Very potent & accounts for about 95% of all
Glucocorticoid activity .It is secreted by The ZONA FASCICULATA which is the middle layer of Adrenal cortex & the deepest layer – ZONA RETICULARIS.
2) Corticosterone: About 4 % of total glucocorticoid activity but much less potent than Cortisol.
3) Cortisone: Synthetic but as potent as Cortisol.
4) Prednisone: Synthetic but 4 times as potent as Cortisol.
5) Methylprednisone: Synthetic but 5 times as potent as Cortisol.
6) Dexamethasone: Synthetic but 30 times as potent as Cortisol.
**** It is clear from the above list that some of these hormones have both Glucocorticoid & Mineralocorticoid activities.
The level of Cortisol needs to be just right. Too much or too little can cause problems. The amount of Cortisol which is made in the adrenal glands is controlled by another hormone called Adreno-cortico-trophic hormone, or ACTH for short (and sometimes just called Corticotrophin). ACTH is made in the pituitary gland.
The pituitary gland lies just below the brain. It makes several hormones, including ACTH. The amount of ACTH made by the pituitary gland is largely controlled by another hormone called Corticotrophin releasing hormone (CRH). CRH is made in a small part of the brain called the hypothalamus, which is just above the pituitary gland. CRH 'stimulates' certain cells in the pituitary to make ACTH.
ACTH passes into the bloodstream, is carried to the adrenal glands, and 'stimulates' the adrenal gland to make Cortisol. If the level of ACTH increases in the bloodstream, the adrenals make more cortisol.But, Cortisol has a negative 'feedback' effect on the pituitary gland. As the level of Cortisol in the bloodstream rises above a certain level, it 'turns down' the amount of ACTH made by the pituitary. This means the adrenal is then stimulated less, and less Cortisol is made. So, the level of Cortisol is kept within a certain range - just enough as is needed by the body.
MAJOR FUNCTION OF GLUCOCORTICOIDS :
By far the best known metabolic effect of Cortisol & other glucocorticoids on metabolism is their ability to stimulate Gluconeogenesis ( a metabolic process in which glucose is formed from non-carbohydrate carbon substrates such as lactate , glycerol , and glucogenic amino acids by the liver ) . Cortisol often increases the rate of gluconeogenisis as much as six to ten folds. Cortisol causes gluconeogenesis by increasing all the enzymes in the liver cell which are required to convert amino acids to glucose. Also Cortisol causes mobilization of amino acids from the extra hepatic tissues ( mainly muscles ) .As a result more amino acids become available in the plasma to enter into the gluconeogenisis process of the liver & thereby to promote the formation of glucose .Not only this Cortisol causes a moderate decrease in the rate of glucose utilization by the cells every where in the body .
ADRENAL DIABETES:
Excessive production of Cortisol leads to ADRENAL DIABETES Adrenal Diabetes has many similarities with Pancreatic Diabetes. In Adrenal Diabetes the blood Glucose concentration is 50 % or more above normal levels. Administration of Insulin lowers the blood glucose concentration only to a moderate amount .Therefore it said that Adrenal Diabetes is moderately sensitive to Insulin.
CAUSES OF EXCESSIVE PRODUCTION OF CORTISOL:
1) Non Cancerous tumor of Pituitary Gland (Pituitary Adenoma). In this condition the Pituitary gland produces more ACTH (CORTICOTROPHIN) which stimulates the Adrenal gland to produce more Cortisol & the abnormal cells in the adenoma are not 'turned down' by feedback from the high levels of cortisol.
2) Non Cancerous or malignant tumor of Adrenal gland causes excessive production of Cortisol.
3) Hyperplasia of Adrenal gland also leads to more production of Cortisol.
4) Some malignant & non cancerous tumors in other parts of body sometimes cause excessive production of Cortisol by producing ectopic ACTH. ACTH is a hormone which stimulates the Adrenal glands to produce Cortisol. Normally ACTH is produced by Pituitary gland. However some rare tumors like that of Lung cancer produce ectopic ACTH which stimulates the Adrenals to produce Cortisol
5) Excessive intake of Alcohol also increases Cortisol levels.
6) Depression is also responsible for higher production of Cortisol.
TREATMENT:
Depends upon the cause of excessive production of Cortisol. If it is due to excessive intake of Alcohol than avoidance of alcohol will cure Adrenal diabetes. If it is due to tumor of Pituitary or Adrenal gland or other part of body than removal of tumor will cure the Diabetes.
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