(ri-spons′ )

[L. responsum, an answer]

1. A reaction, e.g., contraction of a muscle or secretion of a gland, resulting from a stimulus.
SEE: reaction
2. The total of an individual's reactions to specific conditions, e.g., the response of a patient to a certain treatment or to a challenge to the immune system.

acute phase response

SEE: Acute phase reaction.

auditory evoked response

Response to auditory stimuli determined by a method independent of the individual's subjective response. The electroencephalogram has been used to record response to sound. By measuring intensity of sound and presence of response, one can test the acuity of hearing of psychiatric patients, people who are asleep, and children too young to cooperate in a standard hearing test.

brainstem auditory evoked response

SEE: Evoked response audiometry.

clinical benefit response

ABBR: CBR An improvement in at least one important symptom or element of the quality of life of a cancer patient that directly results from treatment, without any decline in any other element of the patient's quality of life.

Some cancers are not curable or responsive to treatment with surgery, radiation, or chemotherapy. However, one or more of their most distressing symptoms may be manageable, e.g., alleviation of pain by therapy. Palliation of pain, nausea, or breathlessness, even in the absence of cure, is a clinically beneficial goal of treatment for some incurable tumors, such as cancers of the pancreas.

complete response

ABBR: CR In cancer care, the eradication by treatment of all of a readily identifiable tumor. A complete response differs from a cure in that microscopic amounts of tumor may remain in the patient and later produce a relapse.

conditioned response

SEE: conditioned reflex

Cushing response

SEE: Cushing, Harvey

defense-oriented response

A coping mechanism by which people try to protect themselves from anxiety or psychological harm.

dose response

1. The relationship between the quantity or intensity of a treatment regimen and its effect on living cells, tissues, or organisms.
2. The relationship between the intensity of an exposure, e.g., to an infectious pathogen, physical stressor, or a toxin, and its effect on living organisms.

durable response

In cancer care, a long-lasting positive reaction to tumor therapy, usually lasting at least a year.

end of treatment response

ABBR: EOT, ETR In the treatment of chronic hepatitis C and other viral infections, the eradication of detectable virus from the blood after a complete course of antiviral therapy.

evoked response

SEE: Evoked potential.

F response

In electrodiagnostic study of spinal reflexes, the time required for a stimulus applied to a motor nerve to travel in the opposite direction up the nerve to the spinal cord and return.

galvanic skin response

The measurement of the change in the electrical resistance of the skin in response to stimuli.

hematological response

In patients with leukemia, a return of the blood cell count to normal. Hematological responses may be partial or complete. A partial hematological response is one in which elevated cell counts decrease significantly but do not completely normalize. A complete hematological response is one in which the patient's elevated circulating blood cells do not differ from levels found in healthy individuals in the community. A complete hematological response does not imply that the patient has been cured of the disease.

histological response

The improvement in the appearance of microscopic tissue specimens after treatment of the patient with chemotherapy. Although it is not indicative of a cure, the improved appearance of biopsy specimens after treatment often suggests the patient's prognosis will improve as well.

immune response

The body's reaction to foreign antigens so that they are neutralized or eliminated, thus preventing the diseases or injuries these antigens might cause. It requires that the body recognize the antigen as nonself. There are several major components to the immune response. The nonspecific immune response, or inflammation, is the response of the body's tissues and cells to injury from any source, e.g., trauma, organisms, chemicals, ischemia. As the initial response of the immune system to any threat, it involves vascular, chemical, and white blood cell activities. The specific immune response, involving T cells and B cells, is a reaction to injury or invasion by particular organisms or foreign proteins. The cell-mediated immune response is the activity of T lymphocytes (T cells) produced by the thymus in response to antigen exposure. Without T cells, the body cannot protect itself against many disease-causing microbes. The loss of T cells in patients with AIDS, for example, leads to infections with many opportunistic microbes that would otherwise be relatively well tolerated by persons with intact cellular immunity. T-cell activity also is the basis for delayed hypersensitivity, rejection of tissue transplants, and responses to cancers. The humoral immune response is the production of antigen-specific antibodies by plasma B lymphocytes (B cells); antibodies attach to foreign antigens in the bloodstream, helping to inactivate or remove them.
SEE: cell-mediated immunity; SEE: humoral immunity; SEE: inflammation

inflammatory response

SEE: Inflammation.

minor response

In cancer care, a reduction in tumor size by less than 50% but more than 25%.

molecular response

In patients with leukemia, eradication from blood or tissue samples of unique tumor DNA. Molecular responses are determined by the absence of tumor DNA despite highly sensitive test methods, such as polymerase chain reaction testing. Molecular responses are classified as major or complete. In a major complete response, tumor DNA (such as the bcr-abl gene in chronic myelogenous leukemia) is detected in very small numbers in blood or bone marrow. In a complete molecular response, no copies of malignant genes are found in available biochemical detection tests.
Molecular responses suggest remission from disease rather than a cure.

SYN: SEE: complete molecular remission

parachute response

SEE: Parachute reflex.

partial response

ABBR: PR In cancer care, a reduction in the size of readily identifiable tumors by 50% or more.

physiological stress response

SEE: Stress response.

primary immune response

The initial reaction to an immunogen, during which T and B lymphocytes are activated and antibodies specific to the antigen are produced. This reaction is considered relatively weak but produces large numbers of antigen-specific memory cells.

PSA response

A decrease in the level of prostate-specific antigen (PSA) of at least 50% in a patient receiving treatment for prostate cancer.

relative dose response

1. A progressively increasing reaction of a cell, tissue, or organism to a stimulus.
2. A test used to estimate liver stores of vitamin A in order to identify those with marginal vitamin A deficiency.

relaxation response

The physiological responses produced when one sits quietly with the eyes closed and breathes slowly and methodically. The responses include slower heart rate, decreased blood pressure, and lowered cutaneous resistance. A brief word or phrase (such as a mantra) may be repeated to oneself to help focus the mind or reduce stray thoughts. This approach to meditation or stress reduction may be undertaken once or twice a day, usually for 10 to 30 min. The relaxation response helps reduce anxiety, high blood pressure, pain, postmenopausal symptoms, and use of medications.

reticulocyte response

An increase in reticulocyte production in response to the administration of a hematinic agent.

secondary immune response

The rapid, strong response by T and B cells to a second or subsequent appearance of an immunogen. This occurs because of the availability of T and B lymphocyte memory cells.

somatosensory evoked response

ABBR: SER Response produced by small, painless electrical stimuli administered to large sensory fibers in mixed nerves of the hand or leg. The electroencephalographic record of the character of the subsequent waves produced helps determine the functional state of the nerves involved.

stress response

The predictable physiological response that occurs in humans as a result of injury, surgery, shock, ischemia, or sepsis.
SYN: SEE: physiological stress response
This response is hormonally mediated and is divided into three distinct phases:

Ebb phase (lag phase): For 12 to 36 hr after the precipitating event, the body attempts to conserve its resources. Vital signs (heart, respiration, temperature) are less than normal. Flow phase (hypermetabolic phase): This stage peaks in 3 to 4 days and lasts 9 to 14 days, depending on the extent of the injury or infection and the person's physical and nutritional status. Carbohydrate, protein, and fat are mobilized from tissue stores and catabolized to meet the energy needs of an increased metabolic rate (hypermetabolism). Serum levels of glucose and electrolytes such as potassium can increase dramatically. If this stage is not controlled by removal of the cause or activator, multiple system organ failure or death can result. Anabolic phase (recovery): The anabolic, or healing, phase occurs as the catabolism declines and electrolyte balances are restored. Aggressive nutritional support is often necessary to promote a positive nitrogen balance.

sustained virological response

ABBR: SVR In the treatment of chronic hepatitis C, having no detectable viral RNA in the blood several months after the completion of antiviral therapy. SVR is evidence of disease remission, and in many people, of cure.
SYN: SEE: virologic cure

tonic immobility response

Muscular paralysis that occurs during significant stress or injury, e.g., as an animal is fleeing or trying to fight off a predator. It is a common reaction experienced by animals and humans faced with overwhelming force, e.g., in battle or during sexual assault.

triple response

Any of the three phases of vasomotor reactions that occur when a sharp object is drawn across the skin. In order of appearance, these are red reaction, flare or spreading flush, and wheal.

ultrarapid virological response

ABBR: URVR The clearing of all hepatitis C viral RNA from the bloodstream after just 2 weeks of antiviral therapy.

unconditioned response

An inherent response rather than a learned response.
SEE: conditioned reflex

visual evoked response

ABBR: VER A reaction produced in response to visual stimuli. While the patient is watching a pattern projected on a screen, the electroencephalogram is recorded. The characteristics of the wave form, its latency, and the amplitude of the wave can be compared with the normal, and important information concerning the function of the visual apparatus in transmitting stimuli to the brain can be obtained.

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