- O –
Obesity: If your body stores more energy than you
need, this can make you overweight. The excess energy is stored in your fat
cells. If your weight goes above a certain level, doctors call this obesity.
Obesity is considered a medical condition. The excess weight can be a strain on
your bones and joints. And if you are obese, you're more likely to get other
diseases. Doctors have developed a scale for telling how much excess weight you
have. This measure, called the body mass index (BMI), depends on your height.
Obstruction: Blockage of a passageway. See, for
example: Airway obstruction; Intestinal obstruction.
Octreotide: Octreotide
(brand name Sandostatin,
Novartis Pharmaceuticals) is an octapeptide that mimics natural somatostatin
pharmacologically, though it is a more potent inhibitor of growth hormone,
glucagon, and insulin than the natural hormone. If the tumor is not amenable to
surgical removal and is causing symptoms by secreting functional hormones, octreotide,
may lessen the symptoms, and sometimes also slows tumor growth.
Oncologist: A physician who specializes in the
diagnosis and treatment of cancer. After a cancer diagnosis is made, it is the
oncologist’s role to explain the cancer diagnosis and the meaning of the
disease stage to the patient; discuss various treatment options; recommend the
best course of treatment; deliver optimal care; and improve quality of life
both through curative therapy and palliative care with pain and symptom
management.
Oncology: The field of medicine that is devoted
to cancer. Clinical oncology consists of three primary disciplines: medical
oncology (the treatment of cancer with medicine, including chemotherapy),
surgical oncology (the surgical aspects of cancer including biopsy, staging,
and surgical resection of tumors), and radiation oncology (the treatment of
cancer with therapeutic radiation).
Open Label Trial: A clinical trial in which both the participant and the medical staff are
aware of which treatment the person is receiving.
Operation: In medicine, a surgical procedure.
Many operations are named after persons. They range from A to Z, from the Abbe
operation (on the lip) to the Ziegler operation (on the eye).
Organ: A relatively independent part of the body
that carries out one or more special functions. Examples of organs include the
eyes, ears, heart, lungs, and liver.
- P –
Pain: An unpleasant sensation that can range
from mild, localized discomfort to agony. Pain has both physical and emotional
components. The physical part of pain results from nerve stimulation. Pain may
be contained to a discrete area, as in an injury, or it can be more diffuse, as
in disorders like fibromyalgia. Pain is mediated by specific nerve fibers that
carry the pain impulses to the brain where their conscious appreciation may be
modified by many factors.
Pain threshold: The
point at which a person becomes aware of pain.
Palliative care: 1) Medical or comfort care that
reduces the severity of a disease or slows its progress rather than providing a
cure. For incurable diseases, in cases where the cure is not recommended due to
other health concerns, and when the patient does not wish to pursue a cure,
palliative care becomes the focus of treatment. For example, if surgery cannot
be performed to remove a tumor, radiation treatment might be tried to reduce
its rate of growth, and pain management could help the patient manage physical
symptoms. 2) In a negative sense, provision only of perfunctory health care
when a cure is possible.
Palpation: A simple technique in which a doctor
presses on the surface of the body to feel the organs or tissues underneath.
Pancreas: A spongy, tube-shaped organ that is
about 6 inches long and is located in the back of the abdomen, behind the
stomach. The head of the pancreas is on the right side of the abdomen. It is
connected to the upper end of the small intestine. The narrow end of the
pancreas, called the tail, extends to the left side of the body. The pancreas
makes pancreatic juices and hormones, including insulin and secretin.
Pancreatic juices contain enzymes that help digest food in the small intestine.
Both pancreatic enzymes and hormones are needed to keep the body working
correctly. As pancreatic juices are made, they flow into the main pancreatic
duct, which joins to the common bile duct, which connects the pancreas to the
liver and the gallbladder and carries bile to the small intestine near the
stomach. The pancreas is thus a compound gland in the sense that it is composed
of both exocrine and endocrine tissues. The exocrine function of the pancreas
involves the synthesis and secretion of pancreatic juices. The endocrine function
resides in the million or so cellular islands (the islets of Langerhans) that
are embedded between the exocrine units of the pancreas. Beta cells of the
islets of Langerhans secrete insulin, which helps control carbohydrate
metabolism. Alpha cells of the islets of Langerhans secrete glucagon, which
counters the action of insulin.
Pancreas Tissues: There are two main types of tissue
found in the pancreas: exocrine tissue and endocrine tissue. Most of the
pancreas - about 95% - is exocrine tissue that produces pancreatic enzymes to
aid digestion. A healthy pancreas makes about 2.2 pints (1 liter) of these
enzymes every day.
Pancreatectomy: A surgical procedure in which
part or the entire pancreas is removed.
Pancreatic: Having to do with the pancreas.
Pancreatic cancer: A malignant tumor of the
pancreas. Pancreatic cancer has been called a 'silent' disease because early
pancreatic cancer usually does not cause symptoms. If the tumor blocks the
common bile duct, and bile cannot pass into the digestive system, the skin and
whites of the eyes may become yellow (jaundiced), and the urine may become
darker as a result of accumulated bile pigment (bilirubin).
Pancreatic Duct: The main exocrine duct of the pancreas. Pancreatic enzymes from smaller ducts
empty into the pancreatic duct, join the common bile duct, and enter the
duodenum.
Pancreatic Endocrine
Cancer: A rare cancer that forms in the islets of Langerhans cells (a type
of cell found in the pancreas). Also called islet cell carcinoma.
Pancreatic Function
Test: A test used to help diagnose problems in the pancreas, such as
gastrinomas and pancreatitis. It measures the ability of the pancreas to
respond to the hormone secretin (a hormone that causes other substances to be
released by the stomach, liver, and pancreas). Secretin is given to the patient
by a tube put through the nose or throat into the small intestine and stomach
or by injection into a vein. After a certain amount of time, samples are taken
to be sent to a laboratory for testing. It is a type of pancreatic function
test. Also called secretin stimulation test.
Pancreatic
insulin-producing tumor: An abnormal mass that grows in the beta cells of
the pancreas that make insulin. Pancreatic insulin-producing tumors are usually
benign (not cancer). They secrete insulin and are the most common cause of low
blood sugar caused by having too much insulin in the body. Also called beta
cell neoplasm, beta cell tumor of the pancreas, and insulinoma.
Pancreatic Juice:
Fluid made by the pancreas. Pancreatic juices contain proteins called enzymes
that support digestion.
Pancreatic
polypeptide: A small protein made by the pancreas that helps control the
release of other substances made by the pancreas. The amount of pancreatic
polypeptide in the blood increases after a person eats. It may also increase
with age, and in certain diseases, such as diabetes and pancreatic cancer. Also
called PP.
Pancreatic pseudocyst: A pancreatic pseudocyst is
a circumscribed collection of fluid rich in pancreatic enzymes, blood, and
necrotic tissue, typically located in the lesser sac of the abdomen.
Pancreatic pseudocysts are usually complications of pancreatitis, although in
children they frequently occur following abdominal trauma. Pancreatic
pseudocysts account for approximately 75% of all pancreatic masses. The prefix pseudo-
( Latin for "false") distinguishes them from true
cysts, which are lined by epithelium; pseudocysts are lined with
granulation tissue.
Pancreatitis: Inflammation of the pancreas. Of
the many causes of pancreatitis, the most common are alcohol consumption and
gallstones. Other causes include medications (azathioprine, estrogen,
thiazides, metronidazole, valproic acid, and tetracycline), trauma, abdominal
surgery, abnormalities of the pancreas and intestine, and infections such as
mumps. Acute pancreatitis usually begins with pain in the upper abdomen that
may last for a few days. The pain may be sudden and intense, or it may begin as
a mild pain that is aggravated by eating and slowly grows worse. The abdomen
may be very tender. Other symptoms may include nausea, vomiting, and fever. The
patient often feels and looks very sick. Chronic pancreatitis usually follows
many years of alcohol abuse and may cause pain; malabsorption of food, leading to
weight loss; and diabetes, if the insulin-producing cells of the pancreas
(islet cells) are damaged.
Papillary: A
term used to describe certain tumors which grow in finger-like projections.
Pathologists mostly use this term.
Paracentesis: A
surgical procedure to remove fluid from the abdomen.
Parathyroid Glands: A group of small endocrine glands located in the neck, behind the thyroid
gland. These glands help regulate calcium levels in the blood.
Parenchyma: The key elements of an organ essential to
its functioning, as distinct from the capsule that encompasses it and other
supporting structures. The parenchyma is thus opposed to the connective tissue
framework, or stroma, of an organ.
Partial Response: A decrease in the size of a tumor in response to treatment. The amount of
decrease needed to use the term partial response is specified in the clinical
trial protocol.
Pathologist: A physician who identifies diseases
and conditions by studying abnormal cells and 'tissues.
Percutaneous: Through the skin. For example, a
percutaneous biopsy is a biopsy that is obtained by putting a needle through
the skin in order to obtain tissue within the body for examination.
Peri-ampullary: Around the ampulla of Vater. The peri-ampullary region is comprised
of 4 structures; the ampulla, the duodenum, the bile duct and
the head of the pancreas. It is sometimes difficult to tell which
structure a tumor originated in. In such cases the diagnosis will be a
peri-ampullary tumor.
Peritoneum: A
thin membrane lining the cavity of the abdomen.
Permanent section: Thin slices of biopsy tissue that
are mounted on slides and looked at under a microscope. A permanent section
takes several days to prepare. It tells doctors if the tissue is cancer, the
type of cancer it is, and other information that helps to plan treatment.
Peutz-Jeghers syndrome: Peutz-Jeghers syndrome (PJS)
is an inherited condition that puts people at an increased risk for developing
hamartomatous polyps in the digestive tract, as well as breast, colorectal, and
other types of cancer. A hamartoma is a growth of normal-appearing tissue that
builds up into a benign (noncancerous) tumor. However, the growth can transform
into cancer over time. Cancer begins when normal cells begin to change and grow
uncontrollably, forming a mass called a tumor. A tumor can be noncancerous or
malignant.
Pharmacy: A location where prescription
medications are sold. A pharmacy is constantly supervised by a licensed
pharmacist.
Platelets: Platelets are small disc-shaped particles
found in your blood (along with red blood cells and white blood cells).
Platelets form the clots that stop the bleeding when you've been cut. People
who don't have enough platelets have problems with bleeding too much.
Plexus: 1. In medicine, a network or
tangle of lymphatic vessels, nerves, or veins. For example, the brachial plexus
is a network of nerves leading to the arm. In general, any interwoven entity
made up of elements in a structure or system.
Positron Emission Tomography (PET Scan):
PET scans involve injecting a form of sugar that contains a radioactive
atom into the blood. Cancer cells absorb large amounts of this sugar. A special
camera can show where these cells are. This test is useful to see whether the
cancer has spread to the lymph nodes or other places.
Practical Care: A type of hospice care provided by housekeepers, social workers, and
volunteers. Practical care covers everything from insurance and other financial
matters to routine chores.
Primary cancer: A cancer in the organ it started in. A primary cancer of the pancreas is
one that started in the pancreas as opposed to a cancer that started somewhere
else and only later spread to the pancreas.
Probability: The likelihood that something will
happen. For example, a probability of less than .05 indicates that the
likelihood of something occurring by chance alone is less than 5 in 100, or 5
percent. This level of probability is usually taken as the level of biologic
significance, so a higher incidence may be considered meaningful. Abbreviated as
p.
Prognosis: A forecast for the probable outcome
of a disease based on the experience of large numbers of other patients with
similar stage disease. Importantly, making a prognosis is not an exact science.
Some patients with poor prognosis beat the odds and live longer than anyone
would have predicted.
Progressive Cancer: The increase in size of a cancer tumor or the spread, or metastasis, of
the tumor to another part of the body.
Protease: An
enzyme secreted by the pancreas that breaks down proteins.
Psyllium: A
soluble fiber helpful in regulating bowel movements. Psyllium is found in fiber
supplements such as Metamucil.
PTC: A test sometimes used to help diagnose cancer of
the pancreas. A thin needle is put into the liver. Dye is injected into the
bile ducts so blockages can be seen on x-rays.
Pylorus: A
thick ring of muscle (a sphincter) between the stomach and duodenum. This
sphincter helps control the release of the stomach contents into the small
intestine.
