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Abnormal Genes and Cancer

A Gene is a small part of a Chromosome and contains code for a specific cell function. At times, more than one gene can influence the same cell function. Chemically, the genes are made of  Deoxyribose Nucleic Acids (DNA).There are four different nucleic acids - they are known as  A, T, G & C. AT and GC always appear in pairs and are called Base Pairs. The three of these base pairs make a word of the coded instruction. A gene, on the average, contains 17,000 Base Pairs and  may contain as many as several millions. Human chromosomes carry 3.2 billions of base pairs and only 25,000 genes are known to code proteins.We have 23 pairs of chromosomes and we inherit one strand of  chromosome from each parent.
Believe it or not, every cell of our body has a define time of existence: there is a time to be born, time to achieve maturity, time to die and be replaced by a new cell. Different cell lines have different lifespan e.g. white blood cells live 5 days; red blood cells live 120 days an…

Fat Cells (Adipocytes)

Fat is getting a bad press recenly. It began with convincing epidemiological studies linking increased rate of heart attacks with elevated  blood levels of fat and cholesterol. The present generation of people are repeatedly warned that their bulging waist lines will make them susceptible to many diseases from diabetes to cancers as they grow older.

If fat is that bad : why we have fat cells in the first place?
 You must have seen the painting of the smiling face of Mona Lisa. Now think : if she was skinny like the present day supermodels would her smile be as captivating!
Underneath the skin there is a layer of fatty tissue which protects the body against the elements - acting as a thermal insulator.  Human body has many empty spaces, big or small, all are nicely packed with fatty tissue. Without such packing kidneys, liver, spleen, and other abdominal organs will have hard time in staying in respective places and work -  eye balls will fall off the eye sockets, major jo…

Carcinoid and other Neuroendocrine tumors

Carcinoid means tumor having some but not all the features of cancer when examined under a microscope. Neuroendocrine implies cell destined to become a nerve cell ends up as hormone producing cell.                                                Even though it is known that not all of these peptide producing tumors are derived from the primitive-nerve cell this name is kept because of certain advantages. Neuroendocrine tumors including carcinoids are special tumors for several interesting reasons. Some tumors produce the same hormone/peptide even when they are located in different organs; tumor located in one organ secretes two or more hormones. Carcinoid or neuroendocrine tumors have the same pathological features whether they are benign or malignant, only their biologic behavioral differences make them one or the other. Diagnosis is delayed because of their small size and widespread distribution. Advances in molecular biochemistry and genetics have outpaced clinical medicine as a r…

Parathyroid Glands and Parathyroid Hormone.

In 1880 Ivar Viktor Sandstrom, a Swedish medical student, identified parathyroid glands in human. That was the last major discovery in human anatomy. His discovery remained unknown till 1891 when Eugene Gley of France established endocrine nature of these glands. In 1925 J.B.Collip purified the hormone from these glands and it was known as Collip hormone. The molecular structure of this hormone was established by Potts in 1971. The hormone was called parathormone and now it is known as Parathyroid hormone- in short PTH.
Anatomy and Embryology ------------------------------ In normal circumstance a person has four Parathyroid glands. In rare circumstances a person may have 8 or 16 parathyroid glands or none at all. Parathyroid glands are very small in size about 6cm x 3cm, weighing about 50mg each. They are mustard yellow in color. They are located in the neck, two on the left side and two on the right side, hiding behind the thyroid gland.  The two parathyroid glands that lie behind…

Emphysema

Emphysema in Greek means inflation or blown with puffed cheeks. In medicine emphysema is classified under chronic obstructive lung disease. The underlying structural problem in emphysema  is fragmentation of elastic tissues. In normal lung elastic tissues are abundant in the walls of small air sacs called alveoli.
To demonstrate  the fragmentation of elastic tissue:  Take two identical balloons. Blow one to its full capacity and hold it for a minute then release the air. The balloon will collapse but will not return to its original size.The balloon will appear larger and flabbier compared with the other. In the process of inflation some of the elastic fibers of the balloon were stretched beyond their limits and fractured.When air was released the elastic recoil could not bring the balloon back to the original size and appeared flabby. Emphysematous lungs are like that flabby balloon.
An alveolus (air sac) is the structural and functional unit of lung. Each lung has about 300 millio…

Phosphorus

Phosphorus and calcium are like twin brothers- always together; but also have sibling rivalry. When the product of phosphorus and calcium (phosphorus in mg/dL X calcium in mg/dL) in blood goes over 50, the one having a lower concentration in blood is prevented from getting in from the gut, and or, eliminated through the kidney by the other; like a stronger eagle chick pushes out the weaker one from the nest. Otherwise, calcium phosphate will be deposited in tissues .On other occasions when calcium levels are low, more phosphates are lost in urine and phosphates levels in blood come to par with calcium, like a true twin.
Phosphorus is present in all cells. All DNA and RNA and various enzymes and coenzymes are organic phosphates, also the intermediate products of glucose and fat metabolism, high energy phosphates like ATP, ADP, cyclic ADP, NADP and many other essentials.

Think this way: If phosphorus is rendered inactive; we will not be able to extract energy from food, deliver ox…

Calcium

We have about 4 lbs of calcium in our body, almost entirely in bones and teeth. Blood levels of calcium are 8.5 to 10.5 mg/dl; 50% of blood calcium is in ionized form, and the rest is bouded with serum albumin and immunoglobulin. The intracellular calcium concentration is 400 ng/dl. We loose about 250 mg of calcium daily in urine, feces and sweat. We consume about 500 mg of calcium daily in food.
Calcium not only provides strength and stability of bones, also is the immediate source of ionized calcium of blood. Calcium is essential for muscle functions, heart beats, nerve conduction, clotting of blood, secretion of all glands, and vascular wall contraction and relaxation.
Bones and Calcium. --------------------- The calcium in bone is a loosely bound crystalline hydroxyapatite form of calcium phosphate. Both deposition and resorption of calcium in bone are under direct influence of parathyroid hormone (PTH). Bone is an active living tissue and daily turn over of calcium between bloo…