Clinical Chemistry Blog Notes 05: June 2009

ANSWERS

Labels: cases in GHIH - Saturday, June 27, 2009

Somatostatin 1.Other name for GHIH
delta cells 2. In the pancreatic islet, GHIH is produced in what cells
Serum 3. The specimen of choice for the determination of GHIH.
Hypothalamus 4. This hormone is first isolated where
Somatostatinoma 5. A tumor in the delta cells.
Steatorrhea and Diabetes mellitus 6-7. Name two diseases associated with your answer in no. 5
Radio Immunoassay 8. The method used for GHIH
Gastrointestinal and Pancreatic 9-1o. Besides the pituitary hormone, name another two hormones inhibited by GHIH.

I.Diagnosis: Hypothyroidism

Hypothyroidism (underactive thyroid) is a condition in which your thyroid gland doesn't produce enough of certain important hormones.

Laboratory methods:
1. TSH level
If there is an elevated TSH (thyroid stimulating hormone) level is always required before a diagnosis of hypothyroidism can be made. Normally, the pituitary gland will secrete TSH in response to a low thyroid hormone level. Thus an elevated TSH level would typically suggest an underactive thyroid.

2. Thyroid function panels
-Total T4

-T3 Uptake and
-Free Thyroxine Index (FTI).
These tests should be abandoned because they are unreliable as gauges of thyroid function. The most common traditional way to diagnose hypothyroidism is with a TSH that is elevated beyond the normal reference range. For most labs, this is about 4.0 to 4.5. This is thought to reflect the pituitary's sensing of inadequate thyroid hormone levels in the blood which would be consistent with hypothyroidism. There is no question that this will diagnose hypothyroidism, but it is far too insensitive a measure, and the vast majority of patients who have hypothyroidism will be missed.

3. Basal Body Temperature
Basal body temperature popularized by the late Broda Barnes, M.D. He found the clinical symptoms and the body temperature to be more reliable than the standard laboratory tests was provided. This is clearly better than using the standard tests. However there are problems with using body temperature.
Sleeping under electric blankets or water beds falsely raise temperature
Sensitive and accurate thermometer required
Inconvenient and many people will not do (poor compliance)

II. Diagnosis: Somatostatinoma is a tumor of the delta cells of the endocrine pancreas that produces somatostatin. It is associated with diabetes mellitus and abnormal glucose tolerance. Triad of : Mild Diabetes Mellitus, Steatorrhoea, Gall stones. Commonly found in head of pancreas, and are malignant. Elevated plasma levels of Somatostatin.

Put your thinking cap on! :)

Labels: ghih questions - Tuesday, June 16, 2009

try this...

Identification

______________________1. Other name for GHIH
______________________2. In the pancreatic islet, GHIH is produced in what cells
______________________3. The specimen of choice for the determination of GHIH.
______________________4. This hormone is first isolated where
______________________5. A tumor in the delta cells.
______________________6-7. Name two diseases associated with your answer in no. 5
______________________
______________________8. The method used for GHIH
______________________9-1o. Besides the pituitary hormone, name another two hormones inhibited by GHIH.

CASE

A. Xyza, a 16-year-old gal, four feet and two inches tall with short stature or stunted growth, notices that she had disproportion to the body (arm and upper to lower ratio) and Short fingers, with a wide separation between the middle and ring fingers. What could be the diagnosis for xyza? What are the laboratory methods to be used for the diagnosis? Discuss your answers.

B. A 34 year old man had an excessive fat in the feces, weight loss, and mild hyperglycemia. What could be the disease of the man? Explain your answer.

Growth-Hormone-Inhibiting-Hormone

Labels: GHIH, somatostatin - Tuesday, June 2, 2009

GHIH

The Growth hormone inhibiting hormone is also called Somatostatin. It is also known as Somatotropin release inhibiting hormone (SIH) or Somatotropin release inhibiting factor (SRIF). It is a tetradecapeptide with a disulfide bond that was first isolated from the hypothalamus.

It is considered to be a hypothalamic hormone that inhibited growth secretion. It inhibits the pituitary (growth hormone and thyrotropin), gastrointestinal (gastrin, secretin, vasointestinal peptide) and pancreatic (insulin, glucagon) hormones as well as possesses nonendocrine functions (e.g., inhibition of gastric acid secretion, gastric emptying time and pancreatic enzyme release). It affects neurotransmission and cell proliferation by interacting with the G-protein-coupled somatostatin receptors and by inhibiting the release of numerous secondary hormones.

In the pancreatic islets, somatostatn is produced on the delta cells, which comprise 5-10% of the islet cells. Rare islet tumors, somatostinomas, secrete high levels of somatostastin. Elevated somatostatin levels can also be seen in small cell lung cancer, medullary thyroid cancer and pheochromocytoma.

Reasons why a test need to be performed:

Detect growth deficiencies and abnormalities, including delayed puberty and small stature in adolescents
Helps in the diagnosis of hyperpituitarism that is evident in gigantism or acromegaly
Screen for inadequate or reduced pituitary gland function
Assist in the diagnosis of pituitary tumors or tumors related to the hypothalamus
Evaluate hGH therapy.

Test: Serum Somatostatin

Method: RIA (Radioimmunoassay)
RIA is a laboratory method that measures minute amounts of a substance, such as a hormone or drug, by quantitating the binding, or the inhibition of binding, of a radiolabeled substance to an antibody.

Use: to detect Somatostatinoma , detect growth deficiencies and abnormalities, diagnosis of hyperthyroidism, diagnosis of pituitary hormones

Somatostatinoma- It is a tumor of the delta cells of the endocrine pancreas that produces somatostatin. It is a rare gut neuroendocrine tumors. It is associated with diabetes mellitus , abnormal glucose tolerance and diarrhea with steatorrhea.