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1. opposition, or counteracting force, as opposition of a conductor to passage of electricity or other energy or substance.
2. the natural ability of a normal organism to remain unaffected by noxious agents in its environment; see also immunity.
3. in psychology or psychiatry, conscious or unconscious defenses against change, preventing repressed material from coming into awareness; they can take such forms as forgetfulness, evasions, embarrassment, mental blocks, denial, anger, superficial talk, intellectualization, or intensification of symptoms. It occurs because the blocked association or understanding would be too threatening to face at this point in the therapy; identification of what point the resistance comes at can be an important indicator of the patient's unconscious patterns.
airway resistance the opposition of the tissues of the air passages to air flow: the mouth-to-alveoli pressure difference divided by the rate of air flow. Symbol RA or RAW.
androgen resistance resistance of target organs to the action of androgens, resulting in any of a spectrum of defects from a normal male phenotype in which men have normal genitalia but infertility to complete androgen resistance in which the individual has a female phenotype. Complete androgen resistance is an extreme form of male pseudohermaphroditism in which the individual is phenotypically female but is of XY chromosomal sex; there may be rudimentary uterus and tubes, but the gonads are typically testes, which may be abdominal or inguinal in position. Called also testicular feminization and testicular feminization syndrome. Incomplete androgen resistance is any of various forms less than the complete type, manifested by a male phenotype with various degrees of ambiguous genitalia such as hypospadias and a small vaginal pouch, a hooded phallus, or a bifid scrotum that may or may not contain gonads.
drug resistance the ability of a microorganism to withstand the effects of a drug that are lethal to most members of its species.
insulin resistance see insulin resistance.
multidrug resistance (multiple drug resistance) a phenomenon seen in some malignant cell lines: cells that have developed natural resistance to a single cytotoxic compound are also resistant to structurally unrelated chemotherapy agents. Called also cross-resistance.
peripheral resistance resistance to the passage of blood through the small blood vessels, especially the arterioles.
pulmonary vascular resistance the vascular resistance of the pulmonary circulation; the difference between the mean pulmonary arterial pressure and the left atrial filling pressure divided by the cardiac output. Called also total pulmonary vascular resistance.
total peripheral resistance the vascular resistance of the systemic circulation: the difference between the mean arterial pressure and central venous pressure divided by the cardiac output.
total pulmonary resistance (total pulmonary vascular resistance) pulmonary vascular resistance.
vascular resistance the opposition to blood flow in a vascular bed; the pressure drop across the bed divided by the blood flow, conventionally expressed in peripheral resistance units. Symbol R or R.


/cross-re·sis·tance/ (kros-re-zis´tans) multidrug resistance.


(krôs′rĭ-zĭs′təns, krŏs′-)
Tolerance to a usually toxic substance as a result of exposure to a similarly acting substance: Some insects develop cross-resistance to insecticides.


resistance to a particular antibiotic that often results in resistance to other antibiotics, usually from a similar chemical class, to which the bacteria may not have been exposed. Cross-resistance can occur, for example, to both colistin and polymyxin B or to both clindamycin and lincomycin.


(kraws rĕ-zistăns)
Resistance to one agent or drug that confers resistance to another, usually similar agent.


References in periodicals archive ?
Due to overlap in the binding region of CAP and the amino glycosides, certain mutations confer cross-resistance to CAP and AMK/KAN.
Since MDR is a major obstacle in clinical management of human cancers, it is important to develop novel drugs without cross-resistance in cancer cells resistant to established anticancer drugs.
Cross-resistance and mechanism of resistance to Cry1Ab toxin from Bacillus thuringiensis in a field-derived strain of European corn borer, Ostrinia nubilalis.
pneumoniae isolates from 2010 were examined for cross-resistance to other antimicrobial agents and prevalence in 1CU versus non-ICU settings.
Intermediate failure of a first regimen--some cross-resistance may be present.
In the case of InI, classic mechanisms of resistance lead to rapid virological rebound, and complete cross-resistance is seen between the first-generation compounds raltegravir and elvitegravir (Miller, this issue).
Furthermore, the additional mutations may confer cross-resistance with other drugs from the same class.
Ultimately it is a tradeoff or other issues, since resistance to either abacavir or tenofovir causes cross-resistance to other medications in this class--and neither is a clear "'winner" on this aspect.
This, plus the fact that Bravo has no cross-resistance to strobilurins or triazoles, and has boosted margins pounds 5 per hectare when added to strobilurin programmes in trial plots, makes it an ideal anti-resistance option for maintaining strobilurin benefits on-farm, he said.
Missing doses can lead to resistance (where HIV can "get around" a drug) or cross-resistance (where resistance to one drug results in resistance to others a patient may not have even taken).
It is generally believed that P-glycoprotein and related molecules are responsible for cancer cells or microorganisms pumping out the drugs that constitute many of the conventional chemotherapy agents, giving rise to multidrug resistance, or MDR, which results in a cross-resistance to many drugs affected by MDR.