G: Guanine, one
member of the base pair G-C (guanine-cytosine) in DNA.
Gait: Manner of walking.
Galactose: Sugar found in milk.
Galactosemia: Inherited disorder due to defective metabolism
(processing) of the sugar galactose. Galactosemia is one of the
diseases in many newborn genetic screening panels. The disease
(which can be fatal, if undetected) is treated by avoiding
galactose in the diet.
Gallbladder: A pear-shaped organ that stores bile. It is located
below the liver.
Gallstones: Stones in the gallbladder or in the duct leading
from the gallbladder to the intestine. There are many types of
Gallstones and ERCP (Endoscopic Retrograde
Cholangio-Pancreatography): A diagnostic procedure to examine
diseases of the bile ducts, liver and pancreas. It is
uncomfortable but not painful, is performed under intravenous
sedation, usually without general anesthesia, and has a low
incidence of complications. ERCP provides important diagnostic
information unobtainable by other means. Therapeutic measures
can often be take at the time of ERCP to remove stones in the
bile ducts or to relieve obstructions of the bile ducts, so that
traditional open surgeries can be avoided. ERCP is increasingly
accepted as the diagnostic and therapeutic procedure of choice
in identifying and removing gallstones in the bile ducts.
Gallop rhythm: Heart rhythm like the gallop of a horse.
Gamete: The sperm or egg. In humans, the gametes normally have
Ganglion: The 2nd century Roman physician Galen first used the
word ganglion to denote a nerve complex. Ganglion currently
refers to an aggregation of nerve cell bodies. Another use of
the word ganglion is for a tendon cyst, commonly near the wrist.
Gangrene: Gangrene is the state of death of tissue due to loss
of adequate blood supply.
Gargoylism: From the French gargouille (waterspout), the word
conveys the often-grotesque image of the medieval cathedral
gargoyle. The term gargoylism was once applied to a condition
today called Hurler syndrome.
Gas, intestinal: The complaint referred to as "intestinal gas"
is a common one and the discomfort can be quite significant.
Everyone has gas and eliminates it by burping or passing it
through the rectum. In many instances people think they have too
much gas when in reality they have normal amounts. Most people
produce 1 to 3 pints of intestinal gas in 24 hours and pass gas
an average of 14 times a day. It is made up primarily of
odorless vapors such as carbon dioxide, oxygen, nitrogen,
hydrogen, and in some families, methane. The unpleasant odor is
due to bacteria in the large intestine that release small
amounts of gases containing sulfur.
Gastrectomy: Surgery to remove part of all of the stomach.
Gastric: Having to do with the stomach.
Gastric atrophy: A condition in which the stomach muscles shrink
and become weak. It results in a lack of digestive juices.
Gastritis: Inflammation of the stomach.
Gastric cancer: Cancer of the stomach, the major organ that
holds food for digestion. Stomach cancer (gastric cancer) can
develop in any part of the stomach and spread to other organs.
Stomach ulcers do not appear to increase a personís risk of
developing stomach cancer. Symptoms of stomach cancer are often
vague, such as loss of appetite and weight. The cancer is
diagnosed with a biopsy of stomach tissue during a procedure.
called an endoscopy.
Gastric ulcer: A hole in the lining of the stomach corroded by
the acidic digestive juices which are secreted by the stomach
cells. Ulcer formation is related to H. pyloridus bacteria in
the stomach, anti-inflammatory medications, and smoking
cigarettes. Ulcer pain may not correlate with the presence or
severity of ulceration. Diagnosis is made with barium x-ray or
with the use of a viewing tube slipped through the throat to the
Gastritis: Inflammation of the stomach.
Gastroenteritis: Inflammation of the stomach and the intestines.
Can cause nausea and vomiting and/or diarrhea. Gastroenteritis
has numerous causes: including infectious organisms (viruses,
bacteria, etc.), food poisoning, and stress.
Gastroenterologist: A doctor who specializes in diagnosing and
treating diseases of the digestive system.
Gastroesophageal reflux: The return of stomach contents back up
into the esophagus This frequently causes heartburn because of
irritation of the esophagus by stomach acid. Gastroesophageal
reflux disease (GERD) can lead to scarring and stricture of the
esophagus, requiring stretching (dilating) of the esophagus. 10%
of patients with GERD develop Barrettís esophagus which
increases the risk of cancer of the esophagus. 80% of patients
with GERD also have a hiatal hernia.
Gastrointestinal (GI): Adjective encompassing the stomach and
Gastrostomy: A surgical opening into the stomach. This opening
may be used for feeding usually via a feeding tube called a
Gastroscope: A flexible, lighted instrument that is put through
the mouth and esophagus to view the stomach. Tissue from the
stomach can be removed through the gastroscope.
Gaucherís disease, type 1: A progressive genetic disease caused
by a defect in an enzyme. The enzyme, called glucocerebrosidase,
is needed to break down the chemical glucocerebroside. The
enzyme defect in persons with Gaucherís disease (GD) leads to
the accumulation of glucocerebroside in the spleen, liver, and
lymph nodes. The most common early sign is enlargement of the
spleen (located in the upper left abdomen). Other signs include
low red blood cell counts (anemia), a decrease in blood clotting
cells (platelets), increased pigmentation of the skin, and a
yellow fatty spot on the white of the eye (a pinguecula). Severe
bone involvement can lead to pain and collapse of the bone of
the hips, shoulders, and spine. The GD gene is on chromosome 1.
The disease is a recessive trait. Both parents carry a GD gene
and transmit it for their child with the disease. The parentsí
risk of a child with the disease is 1 in 4 with each pregnancy.
This type of Gaucherís disease (noncerebral juvenile Gaucherís
disease) is most common in Ashkenazi Jews (of European origin)
and is the most common genetic disease among Jews in the United
GD: Gaucherís disease.
Gene: A gene can be defined in various ways. In classical
genetics, a gene is a unit of inheritance. In molecular
genetics, a gene is a sequence of chromosomal DNA required to
make a functional product. Humans have 50-100,000 genes.
Gene deletion: The total loss (or absence) of a gene. Gene
deletion plays a role in birth defects and in the development of
Gene duplication: An extra copy of a gene. Gene duplication is a
key mechanism in evolution. Once a gene is duplicated, the
identical genes can undergo changes and diverge to create two
Gene, evolutionarily conserved: A gene that has remained
essentially unchanged throughout evolution. Conservation of a
gene indicates that it is unique and essential. There is not an
extra copy of that gene with which evolution can tinker. And
changes in the gene are likely to be lethal.
Gene expression: A gene speaks. When a gene is expressed, the
information encoded in the gene is translated into protein or
RNA structures present and operating in the cell. Expressed
genes include genes that are transcribed into messenger RNA
(mRNA) and then translated into protein as well as those genes
that are transcribed into RNA (such transfer and ribosomal RNAs)
but not translated into protein.
Gene family: A group of genes related in structure (and often in
function). The genes in a family are descended from an ancestral
gene. For example, the hemoglobin genes (of critical importance
to red blood cells) belong to one gene family created by gene
duplication and divergence.
Gene markers: Detectable genetic traits or distinctive segments
of DNA that serve as landmarks for a target gene. Markers are on
the same chromosome as the target gene. They must be near enough
to the target gene to be genetically linked to it: to be
inherited usually together with that gene, and so serve as
signposts to it.
Gene mapping: Charting the relative positions of genes on a DNA
molecule or chromosome and the distance, in linkage units or
physical units, between them.
General paresis: A part of late ("tertiary") syphilis a decade
or more after the initial infection, due to chronic inflammation
of the covering and substance of the brain (meningoencephalitis)
which results in progressive dementia and generalized paralysis.
Gene product: The RNA or protein that results from the
expression of a gene. The amount of gene product is a measure of
the degree of gene activity.
Gene testing: Testing a sample of blood (or another fluid or
tissue) for evidence of a gene. The evidence can be biochemical,
chromosomal, or genetic. The aim is to learn whether a gene for
a disease is present or absent.
Gene therapy: The treatment of disease by replacing, altering,
or supplementing a gene that is absent or abnormal and is
responsible for the disease. In studies of gene therapy for
cancer, researchers are trying to bolster the body's natural
capacity to combat cancer and make the tumor more sensitive to
other kinds of therapy. Gene therapy, still in its early stages,
holds great promise for the treatment of many diseases.
Genetic: Having to do with genes, structures found in every cell
of the body. Each gene contains information that directs the
activities of cells and controls the way an individual develops.
Genetic code: The correspondence of the base triplets (trios
composed of A.T.G., or C.) in DNA with the amino acids. The
discovery of the genetic code clearly ranks as one of the
premiere events of what has been called the Golden Age of
Biology (and Medicine).
Genetic screening: Testing a population to identify individuals
at risk for a genetic disease or for transmitting it. Newborns
may be screened for PKU (phenylketonuria), Jews for the gene for
Tay-Sachs disease, Blacks for the sickle cell gene, etc.
Genital: Pertaining to the external and internal organs of
reproduction. (Not to be confused with genetic.)
Genital herpes: A viral infection transmitted through intimate
contact with the moist mucous linings of the genitals. This
contact can involve the mouth, the vagina or the genital skin.
The herpes simplex type 2 virus enters the mucous membranes
through microscopic tears. Once inside, the virus travels to
nerve the roots near the spinal cord and settles there
permanently. When an infected person has a herpes outbreak, the
virus travels down the nerve fibers to the site of the original
infection and when it reaches the skin, the classic redness and
blisters occur. The outbreak of herpes is closely related to the
functioning of the immune system. Women who have suppressed
immune systems, either through stress, disease, or medications,
have more frequent and longer-lasting outbreaks. Commonly just
Genital warts: Warts confined primarily to the moist skin of the
genitals due to viruses belonging to the family of human
papilloma viruses (HPVs) transmitted through sexual contact.
Most infected people have no symptoms but these viruses increase
a womanís risk for cancer of the cervix. The virus can also be
transmitted from mother to baby during childbirth. HPV infection
is the most common sexually transmitted disease in the United
States. It is also the leading cause of abnormal PAP smears and
pre-cancerous changes of the cervix in women. There is no cure
for genital warts virus infection. Once contracted, the virus
can stay with a person for life.
Genitourinary (GU): Pertaining to the genital and urinary
Genome: All of the genetic information, the entire genetic
complement, all of the DNA possessed by any organism. There is,
for example, the human genome, the elephant genome, the mouse
genome, the yeast genome, the genome of a bacteria, etc. Humans
(and many other higher animals) actually have two genomesóa
chromosomal genome and a mitochondrial genomeóthat together make
up their genome.
Genome, chromosomal: All of the genetic information in the
chromosomes of an organism. For humans, that is all of the DNA
contained in our normal complement of 46 rod-like chromosomes in
virtually every cell in the body. (Mature red blood cells, for
one exception, have no nucleus and therefore no chromosomes).
The chromosomal genome is synonymous with the nuclear genome.
Together with the mitochondrial genome, it constitutes the
genome of the human being.
Genome, human: All of the genetic information, the entire
genetic complement, all of the DNA in a person. Humanityís DNA
is the treasury of human inheritance. It is this extraordinary
repository of genetic information which the Human Genome Project
in the United States and comparable programs in other countries
around the world that belong to HUGO (the HUman Genome
Organization) are designed to fully fathom.
Genome, mitochondrial: The genetic information contained in the
circular chromosome of the mitochondrion, a structure located
outside the nucleus in the cytoplasm of the cell. The
mitochondrial genome and the chromosomal (nuclear) genome
together constitute the entire genome.
Genomic library: A collection of clones made from a set of
randomly generated overlapping DNA fragments representing the
entire genome of an organism. As a molecular genetic sequel to
John Steinbeckís "Of Mice and Men", today you can have a mouse
genomic library or a human genomic library.
GERD: Stands for GastroEsophageal Reflux Disease, a disorder in
which there is recurrent return of stomach contents back up into
the esophagus, frequently causing heartburn, a symptom of
irritation of the esophagus by stomach acid. This can lead to
scarring and stricture of the esophagus, which can require
stretching (dilating).10% of patients with GERD develop
Barrettís esophagus which increases the risk of cancer of the
esophagus. 80% of patients with GERD also have a hiatal hernia.
Germ cell tumor: A type of brain tumor.
German measles immunization: The standard MMR vaccine is given
to prevent measles, mumps and rubella (German measles). The MMR
vaccine is now given in two dosages. The first should be given
at12-15 months of age. The second vaccination should be given at
4-6 years (or, alternatively, 11-12 years) of age. Most colleges
require proof of a second measles or MMR vaccination prior to
entrance. Most children should receive MMR vaccinations.
Exceptions may include children born with an inability to fight
off infection, some children with cancer, on treatment with
radiation or drugs for cancer, on long term steroids
(cortisone). People with severe allergic reactions to eggs or
the drug neomycin should probably avoid the MMR vaccine.
Pregnant women should wait until after delivery before being
immunized with MMR. People with HIV or AIDS should normally
receive MMR vaccine. Measles, mumps, and rubella vaccines may be
administered as individual shots, if necessary, or as a
Germinoma: A type of germ cell tumor.
Gestation: From conception to birth.
Giant cell arteritis: A serious disease characterized by
inflammation of the walls of the blood vessels (vasculitis). The
vessels affected by the inflammation are the arteries (hence the
name "arteritis"). The age of affected patients is usually over
50 years of age. Giant cell arteritis can lead to blindness
and/or stroke. It is detected by a biopsy of an artery. Giant
cell arteritis is treated with high dose cortisone-related
medications. Also called temporal arteritis or cranial arteritis.
Gingiva: The gum.
Gingivitis: Gum disease with inflammation of the gums.
Gland: A group of cells that secrete a substance needed by the
Glandular fever: Glandular fever is infectious mononucleosis.
"Mono" and "kissing disease" are popular terms for this very
common illness caused by the Epstein-Barr virus (EBV). By the
time most people reach adulthood, an antibody against EBV can be
detected in their blood meaning they have been infected with EBV.
The illness is less severe in young children. The infection can
be spread by saliva. The incubation period for "mono" is 4 to 8
weeks. Symptoms include fever, fatigue, sore throat, and swollen
lymph glands. "Mono" can cause liver inflammation (hepatitis)
and spleen enlargement. Vigorous contact sports should be
avoided to prevent spleen rupture.
Glaucoma: An eye condition in which the fluid pressure inside
the eyes rises. Untreated, it leads to vision loss or even
blindness. There are several types, including open-angle
glaucoma (the common adult-onset) and acute angle-closure
glaucoma. The common type of glaucoma, open-angle glaucoma, is
an eye disease in which the normal fluid pressure inside the
eyes slowly rises, leading to vision loss or even blindness. At
the front of the eye, there is a small space called the anterior
chamber. Clear fluid flows in and out of the chamber to bathe
and nourish nearby tissues. In glaucoma, for still unknown
reasons, the fluid drains too slowly out of the eye. As the
fluid builds up, the pressure inside the eye rises. Unless this
pressure is controlled, it may cause damage to the optic nerve
and other parts of the eye and loss of vision. Open-angle
glaucoma is so named because the anterior angle of the eye stays
Glaucoma detection: You may know of the "air puff" test or other
tests used to measure eye pressure in an eye examination. But,
this test alone cannot detect glaucoma. Glaucoma is found most
often during an eye examination through dilated pupils after
drops are put into the eyes during the exam to enlarge the
pupils. This allows the eye care professional to see more of the
inside of the eye to check for signs of glaucoma.
Glaucoma, risk factors: if you belong to a high-risk group for
glaucoma, have your eyes examined through dilated pupils every 2
years by an eye care professional. High-risk groups include
everyone with a family history of glaucoma, everyone over the
age of 60 and any Black over the age of 40. (Among Blacks,
studies show that glaucoma is: 5 times more likely to occur in
Blacks than in Whites and about 4 times more likely to cause
blindness in Blacks than in Whites).
Glaucoma, symptoms of: At first, there are no symptoms. Vision
stays normal, and there is no pain. However, as the disease
progress, a person with glaucoma may notice the side vision
gradually failing. That is, objects in front may still be seen
clearly, but objects to the side may be missed. As the disease
worsens, the field of vision narrows and blindness results.
Glaucoma treatment (laser): A laser beam of light is focused on
the part of the anterior chamber where the fluid leaves the eye.
This results in a series of small changes, which makes it easier
for fluid to exit the eye. Over time, the effect of laser
surgery may wear off. Patients who have this form of surgery may
need to keep taking glaucoma drugs.
Glaucoma treatment (medical): Although glaucoma cannot be cured,
it can usually be controlled. Medical treatment can be in the
form of eyedrops or pills. Some drugs are designed to reduce
pressure by slowing the flow of fluid into the eye, while others
help to improve fluid drainage. The regular use of medications
usually controls the increased fluid pressure. However, these
drugs may stop working over time or they may cause side effects
so that the eye care professional may select other drugs, change
the dose, or use other means to deal with the glaucoma.
Glaucoma treatment (surgery): Surgery can also help fluid escape
from the eye and thereby reduce the pressure. However, surgery
is now usually reserved for patients whose pressure cannot be
controlled with eyedrops, pills, or laser surgery.
Glioblastoma multiforme: A type of brain tumor.
Glioma: A name for brain tumors that begin in the glial cells,
or supportive cells, in the brain. "Glia" is the Greek word for
Glossitis: Inflammation of the tongue.
Glottis: The middle part of the larynx; the area where the vocal
cords are located.
Glucocerebrosidase deficiency: Causes Gaucherís disease (type
1), a progressive genetic disease due to an enzyme defect. The
enzyme, glucocerebrosidase, is needed to break down the chemical
glucocerebroside. The enzyme defect in persons with Gaucherís
disease (GD) leads to the accumulation of glucocerebroside in
the spleen, liver, and lymph nodes. The most common early sign
is enlargement of the spleen (located in the upper left
abdomen). Other signs include low red blood cell counts
(anemia), a decrease in blood clotting cells (platelets),
increased pigmentation of the skin, and a yellow fatty spot on
the white of the eye (a pinguecula). Severe bone involvement can
lead to pain and collapse of the bone of the hips, shoulders,
and spine. The GD gene is on chromosome 1. The disease is a
recessive trait. Both parents carry a GD gene and transmit it
for their child with the disease. The parentsí risk of a child
with the disease is 1 in 4 with each pregnancy. This type of
Gaucherís disease (noncerebral juvenile Gaucherís disease) is
most common in Ashkenazi Jews (of European origin) and is the
most common genetic disease among Jews in the United States.
Glucose: The sugar that is the chief source of energy.
Glucocorticoid: A hormone that predominantly affects the
metabolism of carbohydrates and,to a lesser extent, fats and
proteins (and has other effects). Glucocorticoids are made in
the outside portion (the cortex) of the adrenal gland and
chemically classed as steroids. Cortisol is the major natural
glucocorticoid. The term glucocorticoid also applies to
equivalent hormones synthesized in the laboratory.
Glucose-6-phosphate dehydrogenase (G6PD): Deficiency of G6PD is
the commonest disease-causing enzyme defect in humans affecting
an estimated 400 million people. The G6PD gene is on the X
chromosome. Males with the enzyme deficiency develop anemia due
to breakup of their red blood cells when they are exposed to
oxidant drugs such as the antimalarial primaquine, the
sulfonamide antibiotics or sulfones, naphthalene moth balls, or
Glucose tolerance test (GTT): After fasting, a specific amount
(100 grams) of glucose is given by mouth, and the blood levels
of this sugar are measured every hour. Normally, the blood
glucose should return to normal within 2 to 2 Ĺ hours. The GTT
is considered a classic test of carbohydrate metabolism. It is
much used in the diagnosis of diabetes. The GTT depends on a
number of factors including the ability of the intestine to
absorb glucose, the power of the liver to take up and store
glucose, the capacity of the pancreas to produce insulin, and
the amount of "active" insulin.
Gluteal: Pertaining to the buttock region formed by the gluteal
muscles (gluteus maximus, medius, and minimus).
Gluten: A protein found in wheat or related grains and many
foods that we eat. Gluten can be found in a large variety of
foods including soups, salad dressings, processed foods and
natural flavorings. Unidentified starch, binders and fillers in
medications or vitamins can be unsuspected sources of gluten.
Gluten enteropathy: A condition also called celiac sprue whereby
the absorption of food nutrients through the small intestine is
impaired because of an immune (allergic) reaction to gluten, a
protein found in wheat or related grains and many other foods.
Frequent diarrhea and weight loss can be symptoms. A skin
condition called dermatitis herpetiformis can be associated with
celiac sprue. The most accurate test for the condition is a
biopsy of the involved small bowel. Treatment is avoidance of
gluten in the diet. For stubborn sprue, medications are used.
Goiter: Enlargement of the thyroid gland. A goiter is not
cancerous. A goiter can be associated with normal, elevated
(hyperthyroidism) or decreased (hypothyroidism) thyroid hormone
levels in the blood.
Goiter, diffuse toxic: Gravesí disease, the most common cause of
hyperthroidism, too much thyroid hormone.
Goiter, iodide: Just as too little iodine can cause thyroid
disease, so may prolonged intake of too much iodine also lead to
the development of goiter (swelling of the thyroid gland) and
hypothyroidism (abnormally low thyroid activity). Certain foods
and medications contain large amounts of iodine. Examples
include seaweed; iodine-rich expectorants (such as SSKI and
Lugolís solution) used in the treatment of cough, asthma,
chronic pulmonary disease; and amiodarone (Cardorone), an
iodine-rich medication used in the control of abnormal heart
rhythms (cardiac arrhythmias).
Goiter, toxic multinodular: Condition in which the thyroid gland
contains multiple lumps (nodules) that are overactive and
produce excess thyroid hormones. This condition is also known as
Parryís disease or Plummerís disease.
Golferís cramp: A dystonia that affects the muscles of the hand
and sometimes the forearm and only occurs when playing golf.
Similar focal dystonias have also been called typistís cramp,
pianistís cramp, musicianís cramp, and writerísís cramp.
Golferís cramp provides a reason to switch to tennis (and get
"Good" cholesterol: High-density lipoprotein (HDL) cholesterol.
Gonadotropin, human chorionic (hCG): A human hormone made by
chorionic cells (in the fetal part of the placenta), hCG is
directed at the gonads and stimulates them. hCG becomes
detectable (by immunologic means) within days of fertilization
and forms the foundation of the common pregnancy tests. The
level of hCG in maternal serum also enters as one component in
the "double" and the "triple" screens used during pregnancy to
assign risks of Down syndrome and other fetal disorders.
Gonorrhea: A bacterial infection transmitted by sexual contact.
Gonorrhea is one of the oldest known sexually transmitted
diseases (STDs). In women infected with this bacteria (Neisseria
gonorrhoeae), 25-40% will also be infected with another bacteria
that can cause another STD called chlamydia. Gonorrhea is NOT
transmitted from toilet seats. More than half of women infected
with gonorrhea do not have any symptoms. If symptoms occur, they
may include burning or frequent urination, yellowish vaginal
discharge, redness and swelling of the genitals, and a burning
or itching of the vaginal area. Untreated, gonorrhea can lead to
severe pelvic infections.
Gottron's sign: Gottron's sign is a scaly, patchy redness over
the knuckles and is seen in patients with dermatomyositis, an
inflammatory muscle disorder. (see polymyositis).
Gout: Condition characterized by abnormally elevated levels of
uric acid in the blood, recurring attacks of joint inflammation
(arthritis), deposits of hard lumps of uric acid in and around
the joints, and decreased kidney function and kidney stones.
Uric acid is a breakdown product of purines, that are part of
many foods we eat. The tendency to develop gout and elevated
blood uric acid level (hyperuricemia) is often inherited and can
be promoted by obesity, weight gain, alcohol intake, high blood
pressure, abnormal kidney function, and drugs. The most reliable
diagnostic test for gout is the identification of crystals in
joints, body fluids and tissues.
Gout, tophaceous: A form of chronic gout. Nodular masses of uric
acid crystals (tophi) are deposited in different soft tissue
areas of the body. Even though tophi are most commonly found as
hard nodules around the fingers, at the tips of the elbows, and
around the big toe, tophi nodules can appear anywhere in the
body. They have been reported in unexpected areas such as in the
ears, vocal cords, or around the spinal cord!
Gouty arthritis: An attack that is usually extremely painful of
joint inflammation due to deposits of uric acid crystals in the
joint fluid (synovial fluid) and joint lining (synovial lining).
Intense joint inflammation occurs as white blood cells engulf
the uric acid crystals, causing pain, heat, and redness of the
joint tissues. The term "gout" commonly is used to refer to
these painful arthritis attacks but gouty arthritis is only one
manifeatation of gout.
Graft: Healthy skin, bone, or other tissue taken from one part
of the body to replace diseased or injured tissue removed from
another part of the body.
Graft-versus-host disease: A reaction of donated bone marrow
against a patient's own tissue. Also called GVHD.
Granuloma: Any of a number of forms of localized nodular
inflammation in tissues which have a typical pattern when the
involved tissue examined under a microscope. Granulomas
typically are caused by a variety of chemical, biologic, or
physical irritants of the tissue.
Granuloma, fish bowl: Localized nodular skin inflammation (small
reddish raised areas of skin) caused by a bacterium called
mycobacterium marinum. Fish bowl granuloma is typically acquired
by occupational or recreational exposure to salt or fresh water,
often resulting from minor trauma during caring for aquariums.
The diagnosis is suggested by the history of exposure and
confirmed by culturing tissue specimens which yield the
microscopic organism, mycobacterium marinum. The infection can
be treated with a variety of antibiotics, including doxycycline,
minocycline, clarithromycin, rifampin, and
trimethoprim-sulfamethoxazole. Also called "swimming pool
Granuloma, swimming pool: Localized nodular skin inflammation
(small reddish raised areas of skin) caused by a bacterium
called mycobacterium marinum. Swimming pool granuloma is
typically acquired by occupational or recreational exposure to
salt or fresh water, often resulting from minor trauma during
caring for aquariums. The diagnosis is suggested by the history
of exposure and confirmed by culturing tissue specimens which
yield the microscopic organism, mycobacterium marinum. The
infection can be treated with a variety of antibiotics,
including doxycycline, minocycline, clarithromycin, rifampin,
and trimethoprim-sulfamethoxazole. Also called "fish bowl
Granulomatous enteritis: Crohnís disease, a chronic inflammatory
disease of the intestine primarily in the small and large
intestines but which can occur anywhere in the digestive system
between the mouth and the anus. Named after Burrill Crohn who
described the disease in 1932. The disease usually affects
persons in their teens or early twenties. It tends to be a
chronic, recurrent condition with periods of remission and
exacerbation. In the early stages, Crohnís disease causes small
scattered shallow crater-like areas (erosions) called apthous
ulcers in the inner surface of the bowel. With time, deeper and
larger ulcers develop, causing scarring and stiffness of the
bowel and the bowel becomes increasingly narrowed, leading to
obstruction. Deep ulcers can puncture holes in the bowel wall,
leading to infection in the abdominal cavity (peritonitis) and
in adjacent organs.When only the large intestine (colon) is
involved, the condition is called Crohnís colitis. When only the
small intestine is involved, the condition is called Crohnís
enteritis. When only the end of the small intestine (the
terminal ileum) is involved, it is termed terminal ileitis. When
both the small intestine and the large intestine are involved,
the condition is called Crohnís enterocolitis (or ileocolitis).
Abdominal pain, diarrhea, vomiting, fever, and weight loss can
be symptoms. Crohnís disease can be associated with reddish
tender skin nodules, and inflammation of the joints, spine,
eyes, and liver. Diagnosis is by barium enema, barium x-ray of
the small bowel, and colonoscopy. Treatment includes medications
for inflammation, immune suppression, antibiotics, or surgery.
(The disease is also called regional enteritis).
Granulomatous ileitis: Crohnís disease involving the ileum (the
lowest portion of the small intestine).
Gravesí disease: The most common cause of hyperthyroidism (too
much thyroid hormone), Gravesí disease is due to a generalized
(diffuse) overactivity (toxic) of the whole enlarged thyroid
gland (goiter); it is also commonly known as diffuse toxic
goiter. There are three components to Gravesí disease:
hyperthyroidism, protrusion of the eyes (ophthalmopathy), and
skin lesions (dermopathy). Ophthalmopathy can cause sensitivity
to light and a feeling of "sand in the eyes." With further
protrusion of the eyes, double vision and vision loss may occur.
The ophthalmopathy tends to worsen with smoking. Dermopathy is a
rare, painless, reddish lumpy skin rash that occurs on the front
of the leg. Gravesí disease can run in families. Factors that
can trigger Gravesí disease include stress, smoking, radiation
to the neck, medications (such as interleukin-2 and
interferon-alpha), and infectious organisms such as viruses.
Gravesí disease can be diagnosed by a typical thyroid scan
(diffuse increase uptake), the characteristic triad of
ophthalmopathy, dermopathy, and hyperthyroidism, or blood
testing for TSI (Thyroid Stimulating Immunoglobulin) level which
is abnormally high.
Gray matter: The cortex of the brain which contains nerve cell
bodies. The gray matter is in contrast to the white matter, the
part of the brain that contains myelinated nerve fibers. The
gray matter is so named because it in fact appears gray. The
white matter is white because that is the color of myelin, the
insulation covering the nerve fibers. In "The Mysterious Affair
at Styles" (1920), Agatha Christie first quoted the fictional
Belgian detective Hercule Poirot in regard to his gray matter:
"íThis affair must be unravelled from within.í He tapped his
forehead. ĎThese little grey cells. It is "up to them"óas you
say over here.í"
Groin: The area where the thigh meets the hip.
Growing pains: Mysterious pains in growing children, usually in
the legs. These pains are similar to what the weekend gardener
suffers from on Mondayóan overuse type of problem. If in
playing, children exceed their regular threshold, they will be
sore, just like an adult. Growing pains are typically somewhat
diffuse (vs. focal) and are not associated with physical changes
of the area (such as swelling, redness, etc.). The pains are
usually easily relieved by Messages, Tylenol (acetaminophen), or
rest. If the pains persist past a week or there are physical
changes, the child should be seen by a physician.
Guanine (G): One member of the base pair G-C (guanine-cytosine)
Gum disease: Inflammation of the soft tissue (gingiva) and
abnormal loss of bone that surrounds the teeth and holds them in
place. Gum disease is caused by toxins secreted by bacteria in
"plaque" that accumulate over time along the gum line. This
plaque is a mixture of food, saliva, and bacteria. Early
symptoms of gum disease include gum bleeding without pain. Pain
is a symptom of more advanced gum disease as the loss of bone
around the teeth leads to the formation of gum pockets. Bacteria
in these pockets cause gum infection, swelling, pain, and
further bone destruction. Advanced gum disease can cause loss of
otherwise healthy teeth.
Gynecologic oncologists: Doctors who specialize in treating
cancers of the female reproductive organs.
Gynecologist: A doctor who specializes in treating diseases of
the female reproductive organs.
Gynecology: The word comes from the Greek gyno, gynaikos meaning
woman + logia meaning study, so gynecology literally is the
study of women. However, these days gynecology does not address
all of womenís medicine but focuses on disorders of the female
Gynecomastia: Excessive development of the male breasts.
Temporary enlargement of the breasts is not unusual or abnormal
in boys during adolescence or during recovery from malnutrition.
Gynecomastia may be abnormal as, for example, in Klinefelterís