MAC

MAC

 

membrane attack complex; minimal alveolar concentration; Mycobacterium avium complex (disease).

MAC

1. Abbreviation for minimal anesthetic concentration; minimal alveolar concentration; membrane attack complex.

2. Abbreviation for Mycobacterium avium complex.

MAC

membrane attack complex; complex (see under disease ).

MAC

1 abbreviation for membrane attack complex.

2 abbreviation for microcystic adnexal carcinoma.

3 abbreviation for midupper arm circumference.

4 abbreviation for minimum alveolar concentration.

5 abbreviation for Mycobacterium avium complex. See Mycobacterium avium complex disease.

MAC

Abbreviation for:
Macintosh (computer)
major ambulatory category
mammalian artificial chromosome
maximum acceptable concentration
maximum aerobic capacity
Medical Advisory Committee  
Medicare Appeals Council
membrane attack complex
Mental Adjustment to Cancer scale
Migration Advisory Committee  
minimum antibiotic concentration
mitral annular calcification
monitored anaesthesia care
Mycobacterium avium complex

MAC

1. Mammalian artificial chromosome.

2. Maximum allowable change, see there.

3. Maximum allowable concentration.

4. Membrane attack complex, see there.

5. Minimum alveolar concentration.

6. Monitored anesthesia care, see there 8. Mycobacterium avium complex.

MÖnckeberg's sclerosis

; Moenckeberg's sclerosis; medial arterial calcification; MAC calcification of tunica media of small and medium-sized arteries, visible on radiograph

• MAC of larger arteries is associated with peripheral vascular disease and old age

• MAC of small arteries (e.g. intermetatarsal arteries) is strongly associated with distal sensory neuropathy and diabetes mellitus (see Table 1)

Table 1: Long-term systemic complications that predispose to foot problems in patients with diabetes mellitus

Complication	Feature
Vascular	Accelerated formation of atherosclerosis, especially affecting distal (lower-limb) arteries Abnormal vascular endothelium and associated changes of the microvasculature Medial arterial sclerosis; MÖnckeberg's sclerosis of the intermetatarsal arteries
Altered blood components	Abnormal erythrocytes cause tissue ischaemia (erythrocytes do not adopt normal flow characteristics in small vessels; oxygen dissociation is reduced) Abnormal white blood cells predispose to poor healing and susceptibility to infection (white blood cells show less effective phagocytosis, release fewer growth factors and reduced destruction of microorganisms)
Neurological	Abnormal peripheral (motor, sensory and autonomic) nerve conduction, with reduced perception of and reaction to potentially damaging stimuli; autonomic dysfunction predisposes to dryness of the skin, heel fissures, abnormalities of skin blood flow and Charcot joint formation (neuroarthropathy)
Increased susceptibility to infection	Owing to the combined effects of neurological and vascular complications, and altered blood components (see above)
Impaired vision	Diabetic retinopathy and cataract formation reduce the patient's ability to examine the feet and react promptly to potential problems at an early stage
Renal disease	Renal dysfunction predisposes to peripheral oedema Correlation of renal disease and median arterial calcification (MÖnckeberg's sclerosis) Risk of digital gangrene in renal transplant patients
Non-enzymatic glycation of protein	Affects all body proteins, causing 'stiffness' of globular and structural proteins, with: • Joint immobility, especially of the subtalar joint • Loss of normal resilience of epidermal keratin • Contracture of the fascial structures (formation of the diabetic 'claw-foot', with increased loading under the metatarsal heads) • Impaired wound healing, with chronic underlying fibrosis and ischaemia of long-standing chronic wounds (ulcers) and reduced tissue viability

MAC

in anesthetics, minimum alveolar concentration; in immunology, membrane attack complex.