multiple drug resistance

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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.


(ri-zis'tans) [L. resistere, to remain standing]
1. Opposition to a disease, a toxin, or to a physical force.
2. In psychoanalysis, a condition in which the ego avoids bringing into consciousness conflicts and unpleasant events responsible for neurosis; the reluctance of a patient to give up old patterns of thought and behavior. It may take various forms such as silence, failure to remember dreams, forgetfulness, and undue annoyance with trivial aspects of the treatment situation.
3. Force applied to a body part by weights, machinery, or another person to load muscles as an exercise to increase muscle strength.

airway resistance

The impedance to the flow of air into and out of the respiratory tract, measured in cm H2O/L/s. Normal airway resistance is 4 cm H2O/L/s.

antibiotic resistance

The ability of microorganisms to survive in the presence of antibiotics. Mutations have provided some bacteria with genes for enzymes that destroy antibiotics such as penicillins, cephalosporins, or aminoglycosides. Other mutations have changed the structure of bacterial cell walls formerly penetrable by antibiotics or have created new enzymes for cellular functions previously blocked by drugs. Synonym: antimicrobial resistance See: vancomycin-resistant enterococci; resistance transfer factor; methicillin-resistant Staphylococcus aureus


The indiscriminate use of antibiotics provides the selection pressure that creates ever more resistant strains.

antimicrobial resistance

Antibiotic resistance.

antiviral resistance

The developed resistance of a virus to specific antiviral therapy.

bacterial resistance

The ability of bacteria to survive and cause continuous infection in the presence of antibiotics.
See: antiviral resistance; antibiotic resistance; multidrug resistance; transfer factor

bedtime resistance

Misbehaving, stalling tactics, or temper tantrums used by children to avoid going to bed on time. Bedtime resistance may be caused by a variety of emotional or psychological factors, e.g., fear of the dark, loneliness, or the desire for more attention.

beta-lactamase resistance

The ability of microorganisms that produce the enzyme beta-lactamase (penicillinase) to resist the action of certain types of antibiotics, including some but not all forms of penicillin. Beta-lactamases make these microorganisms resistant to antibiotics by catalyzing the destruction of the beta-lactam ring that is essential for their antibacterial activity.

cross resistance

The ability of bacteria, viruses, or cancer cells to live and reproduce despite treatment with more than one drug. In cancer therapy, resistance to a wide range of unrelated drugs may occur after resistance to a single agent has developed.
Synonym: multidrug resistance; multiple drug resistance See: gene amplification

drug resistance

The ability of a disease, esp. one caused by infectious pathogens, to withstand drug treatment.

expiratory resistance

1. The impedence to airflow from the trachea, bronchi, mouth or nose during exhalation.
2. The use of a restricted orifice, or flow resistor, during positive-pressure ventilation to retard the flow of exhaled gases.
3. An objective measure of bronchospasm.

extended-spectrum beta-lactamase resistance

Abbreviation: ESBL
An enzymatically mediated antibiotic resistance found in gram-negative bacilli (such as Klebsiella pneumoniae, Enterobacter cloacae, and Pseudomonas aeruginosa), that make these bacteria resistant to cephalosporins and penicillin antibiotics.

glucocorticoid resistance

1. A rare genetically inherited insensitivity of peripheral tissues to the effects of steroid hormones produced by the adrenal cortex. Affected patients produce excessive compensatory quantities of ACTH and may be affected by hyperandrogenism or mineralocorticoid excess.
2. Insensitivity to treatment with glucocorticoid drugs, e.g., prednisone for asthma or Crohn disease.

insulin resistance

Cellular phenomena that prevent insulin from stimulating the uptake of glucose from the bloodstream and the synthesis of glycogen. Insulin resistance is one of the fundamental metabolic defects found in patients with type 2 diabetes mellitus.

manual resistance

See: resistance exercise

mechanical resistance

See: resistance exercise

multidrug resistance

Abbreviation: MDR
Cross resistance.

multiple drug resistance

Cross resistance.

peripheral resistance

The resistance of the arterial vascular system, esp. the arterioles and capillaries, to the flow of blood.

systemic vascular resistance

Abbreviation: SVR
The resistance to the flow of blood through the body's blood vessels. It increases as vessels constrict (as when a drug like norepinephrine is given) and decreases when vessels dilate (as in septic shock). Any change in the diameter, elasticity, or number of vessels recruited can influence the measured amount of resistance to the flow of blood through the body.

threshold resistance

The amount of pressure necessary in overcoming resistance to flow.

transthoracic resistance

The amount of resistance to the flow of electrical energy across the chest. This is an important factor to consider when electrical therapies such as defibrillation, cardioversion, and transthoracic pacing are used to treat abnormal cardiac rhythms.

viscous resistance

Nonelastic opposition of tissue to ventilation due to the energy required to displace the thorax and airways.

multiple drug resistance

resistance to two or more unrelated ANTIBIOTICS. For example methicillin-resistant STAPHYLOCOCCUS aureus (MRSA) are often resistant not only to other β LACTAM ANTIBIOTICS, but also to certain unrelated antibiotics such as AMINOGLYCOSIDES, which can make MRSA a serious clinical problem. Resistance may be acquired by receiving resistance (R) PLASMIDS or TRANSPOSONS. Multiply resistant strains may arise in nature due to HORIZONTAL GENE TRANSFER of resistance genes.
References in periodicals archive ?
We see great potential for TPI 287 in overcoming multiple drug resistance," stated Leonard P.
These studies demonstrate that MPC-6827 acts through tubulin; however, unlike other current cancer drugs that effect tubulin, MPC-6827 was equally potent in the induction of apoptosis in cancer cell lines, regardless of the cell line's multiple drug resistance status.
The treatment approach uses the Company's vector technology to transfer a gene for multiple drug resistance (MDR-1) into progenitor cells ("stem cells") that give rise to all other cells in the blood system.
The Target Activation BioApplication is a general and versatile investigative tool that will empower researchers to gather a wealth of cellular information about the activity of specific targets, including, but not limited to, measurement of multiple drug resistance, cytoplasmic pH, intracellular ion concentrations, mitochondrial transmembrane potential, GFP expression, cell permeability and membrane potential.
ONCONASE also overcomes the problem of multiple drug resistance, as well as other forms of drug resistance, such as that to cisplatin in the human resistant ovarian carcinoma, as previously published.
Additionally, Phytera applies its genomic expertise around Multiple Drug Resistance Pumps in the design of novel screening systems for drug resistant bacterial and fungal infections.

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