Mycobacterium avium-intracellulare complex

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My·co·bac·te·ri·um avium-intracellulare com·plex (MAIC),

an opportunistic agent of infection, particularly in people with AIDS. Difficult to treat because Mycobacterium avium-intracellulare is resistant to many antibiotics. The organism may also cause chronic lower respiratory tract infections in patients who are not severely immunocompromised, especially those with underlying abnormal lung parenchyma.
Farlex Partner Medical Dictionary © Farlex 2012

My·co·bac·te·ri·um avium-intracellulare com·plex

(MAIC) (mī-kō-bak-tēr'ē-ŭm ā'vē-ŭm in-tră-sel'yū-lār'ē kom'pleks)
Consists of M. avium and M. intracellulare, two similar species. They are commonly found in the environment but have become serious opportunistic agents in pulmonary disease in patients with AIDS. Difficult to treat because Mycobacterium is resistant to many antibiotics.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


(kom'pleks?) [L. complexus, woven together]
1. Intricate.
2. Of a complicated nature.
3. A group of interrelated biological entities.
4. An atrial or ventricular systole as it appears on an electrocardiographic tracing.
5. All the ideas, feelings, and sensations connected with a subject.
6. A subconscious idea (or group of ideas) that has become associated with a repressed wish or emotional experience and that may influence behavior, although the person may not realize the connection with the repressed thoughts or actions.
7. In Freudian theory, a grouping of ideas with an emotional background. These may be harmless, and the individual may be fully aware of them, e.g., an artist sees every object with a view to a possible picture and is said to have established a complex for art. Often, however, the complex is aroused by some painful emotional reaction such as fright or excessive grief that, instead of being allowed a natural outlet, becomes unconsciously repressed and later manifests itself in some abnormality of mind or behavior. According to Freud, the best method of determining the complex is through psychoanalysis. See: Electra complex; Jocasta complex; Oedipus complex
8. An anatomical or intracellular structure.

AIDS-dementia complex

Abbreviation: ADC
Encephalopathy caused by direct infection of brain tissue by HIV. This condition affects patients with severe immunosuppression more often than those whose immune function is stronger. Central nervous system HIV infection affects as many as 15% of AIDS patients, but in 1997 its incidence decreased to approx. 30% of its previous occurrence because of the effectiveness of highly active antiretroviral therapy (HAART). Central nervous system HIV infections in children tend to be more pronounced than those in adults.


The exact cause of AIDS dementia is unknown, but current theories suggest that it results from HIV infection of macrophages in the brain (microglia) and the destructive release of cytokines that disrupt neurotransmitter function.


AIDS dementia is characterized by slow, progressive memory loss, decreased ability to concentrate, a general slowing of cognitive processes, and mood disorders. Motor dysfunction may also be present, including ataxia, bowel and bladder incontinence, and seizures. Higher levels of HIV RNA in the cerebrospinal fluid (CSF viral load) are correlated with increased problems.


Treatment options may include highly active antiretroviral therapies. Since their introduction the incidence of AIDS-dementia complex has decreased.

Patient care

The patient's mental status and level of consciousness must be assessed and documented. Clear documentation is essential to track a patient's changes over time. Orientation to person, place, and time; thought processes (cognition); verbal communication skills; and memory losses can be determined through simple conversations that reveal the patient's ability to recall normal details of the day and previous teaching. Particular attention is paid to patients' abilities to comply with their complex medication regimen; inability to do so requires another person to assume responsibility for this task. The patient's affect and mood; the presence of agitated, restless, or lethargic behavior; and the extent to which clothing is clean and appropriate for the weather may reveal progressing dementia when compared with previously documented mental status assessments.

Interventions are based on clear communication. As patients develop dementia, they may become frightened, and a consistently gentle approach with positive feedback is essential. Clocks, calendars, and memory aids help the patient become reoriented. Step-by-step written instructions should be given to augment verbal instructions. Caregivers need to learn how to reorient the patient, how to recognize and treat hallucinations, how to create a safe environment, how to ensure that basic hygiene needs are met, and how to document medication schedules and intake because patients may forget to eat or drink adequately.

Synonym: HIV-associated dementia See: AIDS

AIDS-related complex

Abbreviation: ARC
The symptomatic stage of infection with human immunodeficiency virus (HIV) before the onset of AIDS. Its clinical signs include fatigue, intermittent fevers, weight loss greater than 10%, chronic or persistent intermittent diarrhea, night sweats, diminished delayed hypersensitivity (skin test) response to common allergens, presence of HIV antibodies in blood, and decreased CD4+ T-lymphocyte count.

amygdaloid complex


anti-inhibitor coagulant complex

A blood product derived from human plasma, used to augment the effects of clotting factors given to patients with hemophilia. Hemophiliacs who have received repeated injections of clotting factors may develop antibodies to those factors, which decreases the effectiveness of hemophilia treatments. Anti-inhibitors are used to counteract the effect of the unwanted antibodies

castration complex

A morbid fear of being castrated.

Eisenmenger complex

See: Eisenmenger syndrome

Ghon complex

See: Ghon complex

HLA complex

Major histocompatibility complex.

immune complex

A substance formed when antibodies attach to antigens to destroy them. These complexes circulate in the blood and may eventually attach to the walls of blood vessels, producing a local inflammatory response. Immune complexes form in type III hypersensitivity reactions and are involved in the development of glomerulonephritis, serum sickness, arthritis, and vasculitis.

inferiority complex

The condition of having low self-esteem. It is a 20th-century term stemming from Adlerian therapy.

inferior olivary complex

Inferior olive.

major histocompatibility complex

Abbreviation: MHC
A group of genes on chromosome 6 that code for the antigens that determine tissue and blood compatibility. In humans, histocompatibility antigens are called human leukocyte antigens (HLA) because they were originally discovered in large numbers on lymphocytes. There are thousands of combinations of HLA antigens. Class I MHC antigens (HLA-A, HLA-B, and HLA-C) are found on all nucleated cells and platelets. Class II antigens (HLA-DR, HLA-DQ, and HLA-DP) are found on lymphocytes and antigen processing cells and are important in the specific immune response. In tissue and organ transplantation, the extent to which the HLA or “tissue type” of the donor and recipient match is a major determinant of the success of the transplant.
Synonym: HLA complex See: histocompatibility locus antigen

membrane attack complex

The combination of complement factors C5 through C9 that directly attack and kill the cell membranes of microorganisms during the terminal attack phase of the complement cascade.
See: complement; inflammation

Mycobacterium avium complex

Abbreviation: MAC, MAI
An atypical mycobacterium that causes systemic bacterial infection in patients with advanced immunosuppression, esp. those with AIDS. It occasionally causes lung infections in patients with chronic obstructive lung disease. Synonym: Mycobacterium avium-intracellulare complex


MAC infection in AIDS patients can cause fatigue, fever, weight loss, cachexia, pancytopenia, and death.


Multiple antimicrobial agents, given at the same time and for long courses, are required to treat MAC. Combination therapy may include a macrolide with drugs such as rifabutin, ethambutol, ciprofloxacin, amikacin, and/or clofazimine.

Mycobacterium avium-intracellulare complex

Mycobacterium avium complex.

nodal premature complex

Abbreviation: NPC
Ectopic cardiac beat originating in the atrioventricular node.

nuclear pore complex

A collection of membrane-associated proteins that regulate the passage of large molecules between the cytoplasm and the cell nucleus.

oculomotor complex

A group of interrelated nuclei found near the midline in the rostral midbrain. They include the oculomotor nucleus and the Edinger-Westphal nucleus, and they innervate somatic muscles, e.g., inferior rectus and levator palpebrae muscles, and visceral muscles (preganglionic parasympathetic axons to the ciliary ganglia) via the oculomotor nerve (CN III).

olivary complex

Olive (2).

osteomeatal complex

The middle turbinate and the middle meatus of the nose.

QRS complex

The pattern traced on the surface electrocardiogram by depolarization of the ventricles. In the anterior chest leads, e.g., V1 to V3, the complex normally consists of a small initial downward deflection (Q wave), a large upward deflection (R wave), and a second downward deflection (S wave). The normal duration of the complex is 0.06 to 0.11 sec. Longer QRS complexes are seen in premature ventricular beats and ventricular arrhythmias.

QRST complex

Q-T interval.

superiority complex

Exaggerated conviction that one is better than others, a pretense used to compensate for a real or imagined inferiority.

superior olivary complex

Superior olive.

symptom complex


tuberous sclerosis complex

Tuberous sclerosis.
Medical Dictionary, © 2009 Farlex and Partners
References in periodicals archive ?
During the past few decades, members of the Mycobacterium avium-intracellulare complex (MAIC) emerged as pathogens of human diseases, including lymphadenitis in children, pulmonary tuberculosis-like disease, and disseminated infections (occurring predominantly in immunocompromised persons, particularly AIDS patients) (1,2).

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