Thyroid cancer is cancer of the thyroid gland. There are four forms: papillary, follicular, medullary and anaplastic. The most common forms (papillary and follicular) are slow growing and may recur but patients under 45 rarely die, and the medullary form also has a good prognosis if it is restricted to the thyroid gland and a poorer prognosis if there has been spread; the anaplastic form is fast-growing and poorly responsive to therapy.
Thyroid nodules are diagnosed by ultrasound guided fine needle aspiration (USG/FNA) or frequently by thyroidectomy (surgical removal and subsequent pathological examination). As the thyroid cancer can uptake iodine, radioactive iodine is a commonly used modality in thyroid carcinomas. However, it is followed by TSH suppression by Thyroxine therapy.
Symptoms
Most often the first symptom of thyroid cancer is a nodule in the thyroid region of the neck, but only 5% of these nodules are malignant. Sometimes the first sign is an enlarged lymph node. Other symptoms that can be present are pain, changes in voice and symptoms of hypo- or hyperthyroidism.
[edit] Diagnosis
After a nodule is found during a physical examination,a referral to an endocrinologist, or a thyroidologist is the best approach. They will begin an evaluation of the patient. They will do or order an ultrasound to confirm the presence of a nodule, and assess the status of the whole gland. TSH, and anti-thyroid antibodies will help decide if there is a functional thyroid disease such as Hashimoto's thyroiditis present that may cause nodular goiter. The most cost-effective, sensitive and accurate test to determine whether the nodule is malignant is the fine needle biopsy. This test, or the ultrasound guided FNA usually yields sufficient cells to assess the risk of malignancy, although in some cases, the suspected nodule is removed surgically for pathological examination. Rarely, a biopsy is done using a large cutting needle, so that the a piece of capsule can be obtained. Blood or imaging tests may be done prior to or in lieu of a biopsy. The possibility of a nodule which secretes thyroid hormone (which is less likely to be cancer) or hypothyoidism is investigated by measuring Thyroid Stimulating hormone (TSH), and the thyroid hormones thyroxine (T4) and triiodothyronine (T3). Tests for serum thyroid autoantibodies are sometimes done as these may indicate autoimmune thyroid disease (which can mimic nodular disease). The blood assays may be accompanied by ultrasound imaging of the nodule to determine the position, size and texture, and to assess whether the nodule may be cystic (fluid filled). Also suspicious findings in a nodule are hypoechoicic, irregular borders, microcalcifications, 4 plus blood flow within the nodule. Less suspicious findings in benign nodules include, hyperechoic, comet tail artifacts from colloid, no blood flow in the nodule and a halo, or smooth border. Some clinicians will also request technetium or radioactive iodine imaging of the thyroid.An I/123 scan showing a hot nodule, accompanied by a lower than normal TSH, is strong evidence that the nodule is cancerous.
[edit] Classification
Thyroid cancers can be classified according to their pathological characteristics. The following variants can be distinguished:
Papillary thyroid cancer (75%, incl. mixed papillary/follicular)
Follicular thyroid cancer (16%)
Medullary thyroid cancer (5-7%)
Anaplastic thyroid cancer (3%)
Lymphoma (1%)
Squamous cell carcinoma, sarcoma (0.5 - 2%)
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The thyroid (from the Greek word for "shield", after its shape) is one of the larger endocrine glands in the body. It is a double-lobed structure located in the neck and produces hormones, principally thyroxine (T4) and triiodothyronine (T3), that regulate the rate of metabolism and affect the growth and rate of function of many other systems in the body. The hormone calcitonin is also produced and controls calcium blood levels. Iodine is necessary for the production of both hormones. Hyperthyroidism (overactive thyroid) and hypothyroidism (underactive thyroid) are the most common problems of the thyroid gland.
[edit] Physiology
The primary function of the thyroid is production of the hormones thyroxine (T4), triiodothyronine (T3), and calcitonin. Up to 40% of the T4 is converted to T3 by peripheral organs such as the liver, kidney and spleen. T3 is about ten times more active than T4[1].
[edit] T3 and T4 production and action
Thyroxine is synthesised by the follicular cells from free tyrosine and on the tyrosine residues of the protein called thyroglobulin (TG). Iodine, captured with the "iodine trap" by the hydrogen peroxide generated by the enzyme thyroid peroxidase (TPO)[2] and linked to the 3' and 5' sites of the benzene ring of the tyrosine residues on TG, and on free tyrosine. Upon stimulation by TSH (see below), the follicular cells reabsorb TG and proteolytically cleave the iodinated tyrosines from TG, forming T4 and T3 (in T3, one iodine is absent compared to T4), and releasing them into the blood. Deiodinase enzymes convert T4 to T3[3]. Thyroid hormone that is secreted from the gland is about 90% T4 and about 10% T3[1].
Cells of the brain are a major target for thyroid hormone. Thyroid hormones play a particularly crucial role in brain development during pregnancy[4]. A transport protein (OATP1C1) has been identified that seems to be important for T4 transport across the blood brain barrier[5]. A second transport protein (MCT8) is important for T3 transport across brain cell membranes[5].
In the blood, T4 and T3 are partially bound to thyroxine-binding globulin, transthyretin and albumin. Only a very small fraction of the circulating hormone is free (unbound) - T4 0.03% and T3 0.3%. Only the free fraction has hormonal activity. As with the steroid hormones and retinoic acid, thyroid hormones cross the cell membrane and bind to intracellular receptors (α1, α2, β1 and β2), which act alone, in pairs or together with the retinoid X-receptor as transcription factors to modulate DNA transcription[1].
[edit] T3 and T4 regulation
The production of thyroxine is regulated by thyroid-stimulating hormone (TSH), released by the anterior pituitary. The thyroid and thyrotropes form a negative feedback loop: TSH production is suppressed when the T4 levels are high, and vice versa. The TSH production itself is modulated by thyrotropin-releasing hormone, which is produced by the hypothalamus and secreted at an increased rate in situations such as cold (in which an accelerated metabolism would generate more heat). TSH production is blunted by somatostatin (SRIH), rising levels of glucocorticoids and sex hormones (estrogen and testosterone), and excessively high blood iodide concentration.
[edit] Calcitonin
An additional hormone produced by the thyroid contributes to the regulation of blood calcium levels. Parafollicular cells produce calcitonin in response to hypercalcemia. Calcitonin stimulates movement of calcium into bone, in opposition to the effects of parathyroid hormone. However calcitonin seems far less essential than PTH, as calcium metabolism remains clinically normal after removal of the thyroid, but not the parathyroids.
It may be used diagnostically as a tumor marker for a form of thyroid cancer (medullary thyroid adenocarcinoma), in which high calcitonin levels may be present and elevated levels after surgery may indicate recurrence. It may even be used on biopsy samples from suspicious lesions (e.g. swollen lymph nodes) to establish whether they are metastasis of the original cancer.
Calcitonin can be used therapeutically for the treatment of hypercalcemia or osteoporosis.
[edit] The significance of iodine
In areas of the world where iodine (essential for the production of thyroxine, which contains four iodine atoms) is lacking in the diet, the thyroid gland can be considerably enlarged, resulting in the swollen necks of endemic goitre.
Thyroxine is critical to the regulation of metabolism and growth throughout the animal kingdom. Among amphibians, for example, administering a thyroid-blocking agent such as propylthiouracil (PTU) can prevent tadpoles from metamorphosing into frogs; conversely, administering thyroxine will trigger metamorphosis.
In humans, children born with thyroid hormone deficiency will have physical growth and development problems, and brain development can also be severely impaired, in the condition referred to as cretinism. Newborn children in many developed countries are now routinely tested for thyroid hormone deficiency as part of newborn screening by analysis of a drop of blood. Children with thyroid hormone deficiency are treated by supplementation with synthetic thyroxine, which enables them to grow and develop normally.
Because of the thyroid's selective uptake and concentration of what is a fairly rare element, it is sensitive to the effects of various radioactive isotopes of iodine produced by nuclear fission. In the event of large accidental releases of such material into the environment, the uptake of radioactive iodine isotopes by the thyroid can, in theory, be blocked by saturating the uptake mechanism with a large surplus of non-radioactive iodine, taken in the form of potassium iodide tablets. While biological researchers making compounds labelled with iodine isotopes do this, in the wider world such preventive measures are usually not stockpiled before an accident, nor are they distributed adequately afterward. One consequence of the Chernobyl disaster was an increase in thyroid cancers in children in the years following the accident. [2]
The use of iodised salt is an efficient way to add iodine to the diet. It has eliminated endemic cretinism in most developed countries, and some governments have made the iodination of flour mandatory. Potassium iodide and Sodium iodide are the most active forms of supplemental iodine.
Blood supply
The thyroid gland is supplied by two pairs of arteries: the superior and inferior thyroid arteries of each side. The superior thyroid artery is the first branch of the external carotid, and supplies mostly the upper half of the thyroid gland, while the inferior thyroid artery is the major branch of the thyrocervical trunk, which comes off of the subclavian artery. In 10% of people, there is an additional thyroid artery, the thyreoidea ima, that arises from the brachiocephalic trunk or the arch of the aorta. Lymph drainage follows the arterial supply.
There are three main veins that drain the thyroid to the superior vena cava: the superior, middle and inferior thyroid veins.
In comparison to the other organs of the body, the Thyroid receives one of the largest blood supplies per gram weight.[citation needed] The largest blood supply is seen in the Carotid arch baroreceptor organ.[citation needed]
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Fluorouracil (5-FU) is a drug that is used in the treatment of cancer. It belongs to the family of drugs called antimetabolites. It is a pyrimidine analog.
Uses
The chemotherapy agent 5-FU (fluorouracil) which has been in use against cancer for about 40 years, acts in several ways, but principally as a thymidylate synthase inhibitor, interrupting the action of an enzyme which is a critical factor in the synthesis of pyrimidine-which is important in DNA replication [1].
Some of its principal use is in colorectal cancer and pancreatic cancer, in which it has been the established form of chemotherapy for decades (platinum-containing drugs are a recent addition).
[edit] Mode of Action
As a pyrimidine analogue, it is transformed inside the cell into different cytotoxic metabolites which are then incorporated into DNA and RNA, finally inducing cell cycle arrest and apoptosis by inhibiting the cell's ability to synthesize DNA. It is an S-phase specific drug and only active during certain cell cycles.
Capecitabine is a prodrug that is converted into 5-FU in the tissues. It can be administered orally.
[edit] Adverse effects
Side effects include myelosuppression, mucositis, dermatitis, diarrhea and cardiac toxicity.
When using a pyrimidine-based drug, all users must be aware that there is a genetic inability to metabolize them. Current theory points to nearly 8% of the population suffering what is termed DPD deficiency. There are laboratory tests to determine the relative activity of the DPD enzyme, but these tests are not currently commercially available, and therefore seem to fall under the domain of research tools. Thousands of patients eagerly await the increased availability of clinical DPD testing. Work in this sector has been carried out in both the US and Europe. Currently there is only one lab planning to offer DPD testing, Coventry Diagnostics. It is expected that with a potential 500,000 people in North America using the pyrimidine-based 5-FU, this form of testing will increase.
5FU may be given as:
an injection into a vein (intravenously) through a fine tube (cannula) inserted into the vein
a drip (infusion) into the vein through a cannula. It may be given through a central line, which is inserted under the skin into a vein near the collarbone, or into a PICC line inserted into a vein in the crook of the arm
cream applied directly to the skin.
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myelosuppression
Bone marrow suppression is a serious side effect of chemotherapy and certain drugs affecting the immune system such as azathioprine. The risk is especially high in chemotherapy for leukaemia.
The bone marrow is where blood cells are formed, and this process is slowed or stopped when bone marrow suppression is caused. This can rapidly lead to life-threatening infection as the body cannot produce leukocytes in response to invading bacteria and viruses, as well as anaemia due to a lack of red blood cells and spontaneous severe bleeding due to deficiency of platelets.
Bone marrow suppression due to azathioprine can be treated by changing to another medication such as mycophenolate mofetil (for organ transplants) or other disease-modifying drugs in rheumatoid arthritis or Crohn's disease. Bone marrow suppression due to anti-cancer chemotherapy is much harder to treat and often involves hospital admission, strict infection control, and aggressive use of intravenous antibiotics at the first sign of infection.
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Mucositis is the painful inflammation and ulceration of the mucous membranes lining the digestive tract. It can occur anywhere from the mouth to the anus. In the oral cavity and esophagus, mucositis is characterized by painful ulceration. Further down the digestive tract, mucositis causes diarrhea, often severe and debilitating. Mucositis is a common side effect of chemotherapy and of radiotherapy, occurring to some degree in approximately 40% of patients who receive cancer chemotherapy. The oral cavity is a common site for mucositis and will be the focus of this article.
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Dermatitis is a blanket term literally meaning "inflammation of the skin". It is usually used to refer to eczema, which is also known as Dermatitis eczema. There are several different types. Usually all of them have in common an allergic reaction to specific allergens.
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Dihydropyrimidine dehydrogenase deficiency (DPD deficiency) is a condition in which there is absent or significantly decreased activity of dihydropyrimidine dehydrogenase. Individuals with this condition may develop life-threatening toxicity following exposure to 5-fluorouracil (5-FU), a chemotherapy drug that is used in the treatment of cancer.
Current research suggests that nearly 8% of the population has at least partial DPD deficiency. A diagnostics determination test for DPD deficiency is available and it is expected that with a potential 500,000 people in North America using 5-FU this form of testing will increase.
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Metastatin: A Hyaluronan-binding Complex from Cartilage That Inhibits Tumor Growth1
Ningfei Liu2, Randall K. Lapcevich2, Charles B. Underhill, Zeqiu Han, Feng Gao, Glenn Swartz, Stacy M. Plum, Lurong Zhang2 and Shawn J. Green2, 3
[Cancer Research 61, 1022-1028, February 1, 2001]
The founding member of the secretoglobin family of small, secreted, disulphide-bridged dimeric proteins found only in mammals[1]. This antiparallel disulfide linked homodimeric protein is multifunctional and found in various tissues in various names such as: Uteroglobin (UG, UGB), Uteroglobin-like Antigen (UGL), Blastokinin, Clara cell secretory protein (CCSP), Clara cell 16 kD protein (17 in rat/mice), Clara Cell-Specific 10 kD Protein (CC10), human protein 1, urine protein 1 (UP-1), polychlorinated biphenyl-binding protein (PCB-BP), human Clara Cell Phospholipid-Binding Protein (hCCPBP), Secretoglobin 1A member 1 (SCGB1A1).[2]
[edit] Function
Real physiologica role is not known. Putative functions are:
Immunomodulation:
Progesterone binding: weak in some animals, especially weak in humans. (Note: UGB is itself progesterone induced gene in the endometrium.)
Inhibits phospholipase A2
binds phosphatidylcholine, phosphatidylinositol,
Binds to fibronectin: The uteroglobulin knockout mice develop Goodpasteur like glomerulopathy due to fibronectin binding of IgA which might potentially be prevented by uteroglobin replacement. However contrary to the animal model claims, human genetic data might suggest that the effect may be indirect [3]
Target of Polychlorinated biphenyl (pcb) binding
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Hyaluronan (also called hyaluronic acid or hyaluronate) is a glycosaminoglycan distributed widely throughout connective, epithelial, and neural tissues. It is one of the chief components of the extracellular matrix, contributes significantly to cell proliferation and migration, and may also be involved in the progression of some malignant tumors.
Medical applications
Hyaluronan is naturally found in many tissues of the body such as skin, cartilage, and the vitreous humor. It is therefore well suited to biomedical applications targeting these tissues. The first hyaluronan biomedical product, Healon, was developed in the 1970s and 1980s and is approved for use in eye surgery (i.e. corneal transplantation, cataract surgery, glaucoma surgery and surgery to repair retinal detachment) [1]. Other biomedical companies also produce brands of hyaluronan for ophthalmic surgery [2][3].
Hyaluronan is also used to treat osteoarthritis of the knee [4][5][6]. Such treatments are administered as a course of injections into the knee joint and are believed to supplement the viscosity of the joint fluid thereby lubricating the joint, cushioning the joint and producing an analgesic effect. It has also been suggested that hyaluronan has positive biochemical effects on cartilage cells. However, some placebo controlled studies [7][8] have cast doubt on the efficacy of hyaluronan injections and hyaluronan is recommended primarily as a last alternative to surgery.
Due to its high biocompatibility and its common presence in the extracellular matrix of tissues, hyaluronan is gaining popularity as a biomaterial scaffold in tissue engineering research. [9] [10]
In some cancers, hyaluronan levels correlate well with malignancy and poor prognosis. Hyaluronan is thus often used as a tumor marker for prostate and breast cancer. It may also be used to monitor the progression of the disease.
Hyaluronan may also be used postoperatively to induce tissue healing, notably after cataract surgery. Current models of wound healing propose that larger polymers of hyaluronic acid appear in the early stages of healing to physically make room for white blood cells, which mediate the immune response.
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Angiomas are benign tumors that are made up of small blood vessels. They usually appear at or near the surface of the skin. Angiomas may appear anywhere on the body, and aren't considered dangerous (although they may be present as symptoms of another more serious disorder, such as cirrhosis). When they are removed, it is generally for cosmetic reasons.
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A Hemangioma is a benign tumour of blood vessels that in most cases will disappear by itself over time. They are formed either during gestation or appear during the first few weeks of life and may present as a birthmark. Hemangiomas occur in approximately ten percent of Caucasians, and are less prevalent in other races. Females are three to five times more likely to have hemangiomas than males. Hemangiomas can be vivid superficial lesions (often referred to as "Strawberry Marks), Ïf they are under the skin they appear as a bluish swelling. Sometimes they can be both superficial and deep. Approximately eighty percent are located on the face and neck, with the next most prevalent location being the liver. Although hemangiomas are benign, some serious complications can occur.
Hemangiomas are relatively common in newborns, and tend to disappear without treatment. The appearance of the tumor may be mistaken for a sign of physical abuse.
Complications
The vast majority of hemangiomas are not associated with complications. Hemangiomas may break down on the surface to form ulcers. If the ulceration is deep, significant bleeding may rarely occur. Ulceration on the diaper area can be painful and problematic.
If a hemangioma develops in the larynx, breathing can be compromised. If they form on an eyelid or in the eye socket, blindness may result. Very rarely, extremely large hemangiomas can cause high output heart failure due to the amount of blood that must be pumped to the excess blood vessels. Lesions adjacent to bone can also cause erosion.
The most frequent complaints about hemangiomas, however, stem from psychosocial complications: the condition can affect a person's appearance and can provoke attention and malicious reactions from others. Particular problems occur if the lip or nose is involved, as distortion can be difficult to treat surgically.
[edit] Treatment
Most hemangiomas disappear without treatment, leaving none to minimal visible marks. Large hemangiomas can leave visible skin changes secondary to severe stretching of the skin or damage to surface texture. When hemangiomas interfere with vision, breathing or threaten significant cosmetic injury, they are usually treated. The mainstay of treatment is oral corticosteroid therapy. If this fails, surgical removal often becomes necessary. Blockage of the airway will often require a tracheostomy to be performed (insertion of an external airway through the front of the neck into the trachea below the level of the obstruction). Smaller raised lesions are sometimes treated with injection of corticosteroid directly into the lesion. Pulsed dye laser can be useful for very early flat lesions if they appear in cosmetically significant areas or for those lesions that leave residual surface blood vessels in the case of incomplete resolution.
Ulceration will usually heal with topical medication and special dressings under medical supervision. Sometimes pulsed dye laser can be used to accelerate healing
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Fatty liver (or steatorrhoeic hepatosis or steatosis hepatis) is a reversible condition where large vacuoles of lipid accumulate in hepatocytes (the cells of the liver). It may be caused by various diseases, such as in chronic alcoholism and obesity.
Accumulation of fat in liver cells may cause the liver to enlarge. The lipid within the vacuoles is a particular type of lipid known as triglyceride. Triglyceride molecules consist of a glycerol backbone with three fatty acid molecules joined on.
[edit] Causes
Many chemicals, such as alcohol and drugs can cause fatty liver.
Fatty liver can occur in diabetes mellitus and in pregnancy (acute fatty liver of pregnancy). It can also be seen both in starvation (especially rapid weight loss) and in obesity. In addition, it is also a minor symptom of hepatitis that may indicate progression to cirrhosis.
Pathology
Fatty change represents the intracytoplasmic accumulation of triglyceride (neutral fats). At the beginning, the hepatocytes present small fat vacuoles (liposomes) around the nucleus - microvesicular fatty change. In the late stages, the size of the vacuoles increases pushing the nucleus to the periphery of the cell - macrovesicular fatty change. These vesicles are well delineated and optically "empty" because fats solves during tissue processing. Large vacuoles may coalesce, producing fatty cysts - which are irrevesible lesions. [1]
Severe fatty liver is accompanied by inflammation, a situation that is referred to as steatohepatitis. The degree of inflammation is related to its progression to more severe forms of liver disease, ultimately cirrhosis. If this occurs in a non-alcoholic patient without viral liver disease, the condition is termed non-alcoholic steatohepatitis.
[edit] Treatment and prevention
The treatment of fatty liver depends on what is causing it, and generally, treating the underlying cause will remove the problem.
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Bloating is any abnormal general swelling, or increase in diameter of the abdominal area. As a symptom, the patient feels a full and tight abdomen, which may cause abdominal pain sometimes accompanied by borborygmus. Bloating may have several causes, the most common being accumulation of liquids and intestinal gas. Ascites is the proper medical term for abdominal bloating caused by excessive accumulation of liquid inside the cavity.
Common causes for abdominal bloating are:
Overeating (gastric distension)
Lactose intolerance, fructose intolerance and other food intolerances
Food allergy
Aerophagia (air swallowing, a nervous habit)
Alvarez' syndrome, hysterical or neurotic abdominal bloating without excess of gas in the digestive tract
Irritable bowel syndrome
Partial bowel obstruction
Gastric dumping syndrome or rapid gastric emptying
The ingestion of some gas-producing foods
Constipation
Splenic-flexure syndrome
Menstruation, dysmenorrhea and premenstrual stress syndrome
Polycystic ovary syndrome and ovarian cysts
Massive infestation with intestinal parasites, such as worms (e.g, Ascaris lumbricoides)
Diverticulosis
Ingestion of food additives, such as Sulfites, by persons sensitive to them.
Important but uncommon causes of abdominal bloating include large intra-abdominal tumors, such as those arising from ovarian, liver, uterus and stomach cancer; and megacolon, an abnormal dilation of the colon, due to some diseases, such as Chagas disease, a parasitic infection.
Gaseous bloating may be a consequence of cardiopulmonary resuscitation procedures, due to the artificial mouth-to-mouth insuflation of air.
Postmortem bloating occurs in cadavers, due to the formation of gases by bacterial action and putrefaction of the internal tissues of the abdomen and the inside of the intestines.
Bloating from Irritable Bowel Syndrome is of unknown origin but often results from an insult to the gut, and as such can overlap with infective diarrhea, celiac, and inflammatory bowel diseases. IBS is a brain-gut dysfunction that causes visceral hypersensitivity and results in bloating in association with recurrent diarrhea (or constipation) and abdominal pain. While there is no direct treatment for the underlying pathology of IBS, the symptom of bloating can be well managed through dietary changes that prevent the over-reaction of the gastrocolic reflex. Having soluble fiber foods and supplements, substituting soy or rice products for dairy, being careful with fresh fruits and vegetables that are high in insoluble fiber, and eating regular small amounts can all help to lessen the symptoms of IBS (Van Vorous 2000). Foods and beverages to be avoided or minimized include red meat, oily or fatty (and fried) products, dairy (even when there is no lactose intolerance), solid chocolate, coffee (regular and decaffeinated), alcohol, carbonated beverages (especially those also containing sorbitol) and artificial sweeteners (Van Vorous 2000).
In some animals, like cats, dogs and cattle, gastric dilatation-volvulus, or bloat also occurs when gas is trapped inside the stomach and a gastric torsion or volvulus prevents it from escaping.
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Dysphagia (/dɪsˈfe(ɪ)ʒjə/, not to be confused with dysphasia) is a medical term defined as "difficulty swallowing." It derives from the Greek root dys meaning difficulty or disordered, and phagia meaning "to eat". It is a sensation that suggests difficulty in the passage of solids or liquids from the mouth to the stomach.[1] Dysphagia is distinguished from similar symptoms including odynophagia, which is defined as painful swallowing, and globus, which is the sensation of a lump in the throat. It is also worthwhile to refer to the physiology of swallowing in understanding dysphagia.
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Dysphasia (/dɪsˈfe(ɪ)zjə/) is a speech disorder in which there is an impairment of speech and of comprehension of speech. It is caused by brain damage, usually in the left side of the brain which is responsible for language and communication. The word comes from the Greek dys- (impairment) and phasia (φασια) (speech).
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Endoscopic ultrasound(EUS) is medical procedure where an endoscopically directed ultrasound is used to image thoracic and abdominal viscera.
The probe is inserted into the stomach and duodenum via esophagogastroduodenoscopy. Among other uses, it allows for screening for pancreatic cancer. It also allows for biopsing of any focal lesions found in the pancreas. This is done by inserting a needle through the stomach lining into the target.
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Fluorodeoxyglucose is a glucose analog. Its full chemical name is 2-fluoro-2-deoxy-D-glucose, commonly abbreviated to FDG.
FDG is most commonly used in the medical imaging modality positron emission tomography (PET): the fluorine in the FDG molecule is chosen to be the positron-emitting radioactive isotope fluorine-18, to produce 18F-FDG. After FDG is injected into a patient, a PET scanner can form images of the distribution of FDG around the body. The images can be assessed by a nuclear medicine physician or radiologist to provide diagnoses of various medical conditions.
Applications
In PET imaging, 18F-FDG can be used for the assessment of glucose metabolism in the heart and the brain. It is also used for imaging tumours in oncology. 18F-FDG is taken up by cells, phosphorylated by hexokinase (whose mitochondrial form is greatly elevated in rapidly-growing malignant tumours)[1], and retained by tissues with high metabolic activity, such as most types of malignant tumours. As a result FDG-PET can be used for diagnosis, staging, and monitoring treatment of cancers, particularly in Hodgkin's disease, non-Hodgkin's lymphoma, and lung cancer. It has also been approved for use in diagnosing Alzheimer's disease.
In body-scanning applications in searching for tumor or metastatic disease, a dose of FDG in solution (typically 5 to 10 millicuries or 200 to 400 MBq) is typically injected rapidly into a saline drip running into a vein, in a patient who has been fasting for at least 6 hours, and who has a suitably low blood sugar. (This is a problem for some diabetics; usually PET scanning centers will not administer the isotope to patients with blood glucose levels over about 180 mg/dL = 10 mmol/L, and such patients must be re-scheduled). The patient must then wait about an hour for the sugar to distribute and be taken up into organs which use glucose—a time during which physical activity must be kept to a minimum, in order to minimize uptake of the radioactive sugar in muscles (this causes unwanted artifacts when the organs of interest are inside the body). Then, the patient is placed in the PET scanner for a series of one or more scans which may take from 20 minutes to as long as an hour (often, only about quarter of the body length may be imaged at a time).
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Fluoroscopy is an imaging technique commonly used by physicians to obtain real-time images of the internal structures of a patient through the use of a fluoroscope. In its simplest form, a fluoroscope consists of an x-ray source and fluorescent screen between which a patient is placed. However, modern fluoroscopes couple the screen to an x-ray image intensifier and CCD video camera allowing the images to be played and recorded on a monitor. The use of x rays, a form of ionizing radiation, requires that the potential risks from a procedure be carefully balanced with the benefits of the procedure to the patient. While physicians always try to use low dose rates during fluoroscopy procedures, the length of a typical procedure often results in a relatively high absorbed dose to the patient. Recent advances include the digitization of the images captured and flat-panel detector systems which reduce the radiation dose to the patient still further.
Common procedures involving the use of fluoroscopy
- Investigations of the gastrointestinal tract, including Barium enemas, barium meals and barium swallows, and enteroclysis.
- Orthopaedic surgery to guide fracture reduction and the placement of metalwork.
- Angiography of the leg, heart and cerebral vessels.
- Urological surgery – particularly in retrograde pyelography.
dilated hepatic ducts in the liver tumor
tumors may push or engulf
right adrenal gland may accidently be taken out during R hepatectomy
spleen much brighter than liver, if liver is fatty?
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ACC
Acetylcysteine (rINN) (IPA: [ˌæsɛtl̩ˈsɪstin, əˌsɛtl̩-, ˌæsətaɪl-]), also known as N-acetylcysteine (abbreviated NAC), is a pharmacological agent used mainly as a mucolytic and in the management of paracetamol overdose. For these indications, acetylcysteine is available under the trade names Mucomyst (Bristol-Myers Squibb) and Parvolex (GSK).
Clinical use
[edit] Mucolytic therapy
Inhaled acetylcysteine is indicated for mucolytic ("mucus dissolving") therapy as an adjuvant in respiratory conditions with excessive and/or thick mucus production. Such conditions include: emphysema, bronchitis, tuberculosis, bronchiectasis, amyloidosis, pneumonia. It is also used post-operatively, as a diagnostic aid, and in tracheostomy care. It is considered ineffective in cystic fibrosis (Rossi, 2006). Oral acetylcysteine may also be used as a mucolytic in less serious cases.
For this indication, acetylcysteine acts to reduce mucus viscosity by splitting disulfide bonds linking proteins present in the mucus (mucoproteins).
[edit] Paracetamol overdose
Intravenous acetylcysteine is indicated for the treatment of paracetamol (acetaminophen) overdose. Oral acetylcysteine for this indication is uncommon as it is poorly tolerated owing to the high doses required (due to poor oral bioavailability), unpleasant taste/odour and adverse drug reactions (particularly nausea and vomiting).
For this indication, acetylcysteine acts to augment glutathione reserves (depleted by toxic paracetamol metabolites) in the body and, together with glutathione to directly bind to toxic metabolites. These actions serve to protect hepatocytes in the liver from toxicity due to paracetamol overdose.
[edit] Nephroprotective agent
Oral acetylcysteine is used for the prevention of radiocontrast-induced nephropathy (a form of acute renal failure). Some studies show that prior administration of acetylcysteine markedly decreases (90%) radiocontrast nephropathy (Tepel et al 2000), while others appear to cast doubt on its efficacy (Hoffman et al., 2004; Miner et al., 2004) Nevertheless, acetylcysteine continues to be commonly used in individuals with renal impairment to prevent the precipitation of acute renal failure.
[edit] Other uses
The following uses have not been well-established or investigated:
- It may reduce the incidence of chronic obstructive pulmonary disease (COPD) exacerbations (Pela et al., 1999)
- It has been proposed as a supplement for patients with AIDS, who generally have decreased glutathione levels. However, it does not appear to be effective in restoring glutathione levels (Witschi et al., 1995).
- An animal study indicates that acetylcysteine may decrease mortality associated with influenza (Ungheri et al., 2000)
- Animal studies suggest that NAC may help prevent noise-induced hearing loss (Kopke et al., 2005). A clinical trial to determine efficacy in preventing noise induced sensorineural hearing loss in humans is currently (2006) being jointly conducted by the US Army and US Navy.
- It has been suggested that NAC may help sufferers of Samter's triad by increasing levels of glutathione allowing faster breakdown of salicylates, though there is no evidence that it is of benefit (Bachert et al., 2003).
- There are claims that acetylcysteine taken together with vitamin C and B1 can be used to prevent and relieve symptoms of veisalgia (hangover following ethanol (alcohol) consumption). The claimed mechanism is through scavenging of acetaldehyde, a toxic intermediate in the metabolism of ethanol.
Presentation of ampullary cancer
Ampullary cancer is a cancer that arises from the Ampulla Vater. The Ampulla Vater is a nipple like projection into the duodenum (the first portion of the intestine) into which the pancreatic and bile ducts open. All of the pancreatic and biliary secretion enter the duodenum through the Ampulla Vater.
Blockage of the Ampulla Vater by the tumor leads to obstruction of drainage of the pancreatic and biliary secretions into the intestine. Blockage of drainage of bile into the duodenum leads to the development of jaundice; since the bile cannot drain into the intestine it accumulates into the bloodstream causing yellowness of the skin.
Patients with ampullary cancer typically present with obstructive jaundice. Frequently the patient will undergo an endoscopy or an ERCP at which time an ulcerating tumor will be identified at the ampulla.
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Pancreatic cancers can arise from both the exocrine and endocrine portions of the pancreas. Of pancreatic tumors, 95% develop from the exocrine portion of the pancreas, including the ductal epithelium, acinar cells, connective tissue, and lymphatic tissue. Approximately 75% of all pancreatic carcinomas occur within the head or neck of the pancreas, 15-20% occur in the body of the pancreas, and 5-10% occur in the tail. Typically, pancreatic cancer first metastasizes to regional lymph nodes, then to the liver, and less commonly, to the lungs. It can also directly invade surrounding visceral organs such as the duodenum, stomach, and colon.
- Patients presenting with end-stage disease may have ascites, a palpable abdominal mass, hepatomegaly from liver metastases, or splenomegaly from portal vein obstruction.
Diagnosis
Courvoisier's law defines the presence of jaundice and a painlessly distended gallbladder as strongly indicative of pancreatic cancer, and may be used to distinguish pancreatic cancer from gallstones.
Pancreatic cancer is usually discovered during the course of the evaluation of aforementioned symptoms. Liver function tests may show a combination of results indicative of bile duct obstruction (raised bilirubin, γ-glutamyl transpeptidase and alkaline phosphatase levels). Ca 19.9 (carbohydrate antigen 19.9) is a tumor marker that is frequently elevated in pancreatic cancer.
Imaging studies, such as ultrasound or abdominal CT may be used to identify tumors. Endoscopic ultrasound (EUS) is another procedure that can help visualize the tumor and obtain tissue to establish the diagnosis.
--------------------------------------------------------------------------Courvoisier's law (or Courvoisier syndrome, or Courvoisier's sign) states that in the presence of a palpable gall bladder, jaundice is unlikely to be caused by gall stones. This is because gall stones are formed over a longer period of time, and this results in a shrunken, fibrotic gall bladder which does not distend easily. Therefore the gall bladder is more often enlarged in pathologies which causes obstruction of the bilary tree, which occur over a shorter period of time such as pancreatic malignancy than in gallstone disease.
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Liver function test(LFT)
Standard liver panel
[edit] Total Protein (TP)
The liver produces most of the plasma proteins in the body making a measure of the amount of protein in the blood useful. Reference range (60-80 g/L).
[edit] Albumin (Alb)
Albumin is a protein made specifically by the liver, and can be measured cheaply and easily. It is the main constituent of total protein; the remaining fraction is called globulin (including e.g. the immunoglobulins). Albumin levels are decreased in chronic liver disease, such as cirrhosis. It is also decreased in nephrotic syndrome, where it is lost through the urine. Poor nutrition or states of protein catabolism may also lead to hypoalbuminaemia. The half-life of albumin is approximately 20 days. Albumin is not considered to be an especially useful marker of liver synthetic function, coagulation factors (see below) are much more sensitive. The reference range is 30-50 g/L. (3.0-5.0 g/dL)
[edit] Alanine transaminase (ALT)
Alanine transaminase (ALT), also called Serum Glutamic Pyruvic Transaminase (SGPT) or Alanine aminotransferrase (ALAT) is an enzyme present in hepatocytes (liver cells). When a cell is damaged, it leaks this enzyme into the blood, where it is measured. ALT rises dramatically in acute liver damage, such as viral hepatitis or paracetamol (acetaminophen) overdose. Elevations are often measured in multiples of the upper limit of normal (ULN). The reference range is 15-45 U/L in most laboratories.
[edit] Aspartate transaminase (AST)
Aspartate transaminase (AST) also called Serum Glutamic Oxaloacetic Transaminase (SGOT) or aspartate aminotransferase (ASAT) is similar to ALT in that it is another enzyme associated with liver parenchymal cells. It is raised in acute liver damage, but is also present in red cells, and cardiac and skeletal muscle and is therefore not specific to the liver. The ratio of AST to ALT is sometimes useful in differentiating between causes of liver damage:
- ALT>AST: acute viral hepatitis or drug-induced hepatitis
- ALT
In resource-poor settings, the AST is more frequently available than the ALT, because it is a cheaper assay.
[edit] Alkaline phosphatase (ALP)
Alkaline phosphatase (ALP) is an enzyme in the cells lining the biliary ducts of the liver. ALP levels in plasma will rise with large bile duct obstruction, intrahepatic cholestasis or infiltrative diseases of the liver. ALP is also present in bone and placental tissue, so it is higher in growing children (as their bones are being remodelled). The reference range is usually 30-120 U/L.
[edit] Total bilirubin (TBIL)
Bilirubin is a breakdown product of heme (a part of hemoglobin in red blood cells). The liver is responsible for clearing this, excreting it out through bile into the intestine. Problems with the liver or blockage of the drainage of bile will cause increased levels of bilirubin, as will increased haemolysis of red cells.
Direct bilirubin, or conjugated bilirubin is often measured in tandem, especially if the total bilirubin level is elevated. Bilirubin is unconjugated, also known as indirect bilirubin, before the liver modifies it for excretion. It is dangerous in babies, as it can pass the blood-brain barrier causing kernicterus.
[edit] Other tests commonly requested alongside LFTs:
[edit] Gamma glutamyl transpeptidase (GGT)
Although reasonably specific to the liver and a more sensitive marker for cholestatic damage than ALP, Gamma glutamyl transpeptidase (GGT) may be elevated with even minor, sub-clinical levels of liver dysfunction. It can also be helpful in identifying the cause of an isolated elevation in ALP. GGT is raised in alcohol toxicity (acute and chronic).
[edit] 5' nucleotidase (5'NTD)
5'NTD is another test specific for cholestasis or damage to the intra or extrahepatic biliary system, and in some laboratories, is used as a substitute for GGT for ascertaining whether an elevated ALP is of biliary or extra-biliary origin.
[edit] Coagulation tests (e.g. INR)
The liver is responsible for the production of coagulation factors. The international normalized ratio (INR) measures the speed of a particular pathway of coagulation, comparing it to normal. If the INR is increased, it means it is taking longer than usual for blood to clot. The INR will only be increased if the liver is so damaged that synthesis of vitamin K-dependent coagulation factors has been impaired: it is not a sensitive measure of liver function.
It is very important to normalize the INR before operating on people with liver problems (usually by transfusion with blood plasma containing the deficient factors) as they could bleed excessively.
[edit] Serum glucose (BG, Glu)
The liver's ability to produce glucose (gluconeogenesis) is usually the last function to be lost in the setting of fulminant liver failure.
--------------------------------------------------------------------------Main Entry: car·ci·no·ma·to·sis
Pronunciation: -
-m
-
t-ssFunction: noun
Inflected Form(s): plural -to·ses /-
s
z/: a condition in which multiple carcinomas develop simultaneously usually after dissemination from a primary source
