MAC(redirected from HD-MAC)
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1. Abbreviation for minimal anesthetic concentration; minimal alveolar concentration; membrane attack complex.
2. Abbreviation for Mycobacterium avium complex.
MACmembrane attack complex; complex (see under disease ).
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
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)
|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
in anesthetics, minimum alveolar concentration; in immunology, membrane attack complex.