[h=1]Transcutaneous PO2 of the scalp in male pattern baldness: a new piece to the puzzle.[/h]
Goldman BE,
Fisher DM,
Ringler SL.
[h=3]Source[/h]Department of Plastic Surgery, Butterworth Hospital, Grand Rapids, Mich., USA.
[h=3]Abstract[/h]Our study was designed to measure the transcutaneous PO2 of the scalp to determine if there was a relative microvascular insufficiency and associated tissue hypoxia in areas of hair loss in male pattern baldness. A controlled prospective study was performed at Butterworth Hospital, Grand Rapids, Michigan. Eighteen nonsmoking male volunteers aged 18 years and older were studied. Nine men had male pattern baldness (Juri degree II or III), and nine were controls (no male pattern baldness). Scalp temperature and transcutaneous PO2 were obtained at frontal and temporal sites in each subject. Peripheral circulation was assessed from postocclusive transcutaneous PO2 recovery time by means of maximum initial slope measurements. Statistical significance was assessed at p < 0.05. There was no significant difference in scalp temperature between male pattern baldness subjects and controls. Temporal scalp blood flow was significantly higher than frontal scalp blood flow in male pattern baldness subjects; however, there was no significant difference in controls. Transcutaneous PO2 was significantly lower in bald frontal scalp (32.2 +/- 2.0 mmHg) than in hair-bearing temporal scalp (51.8 +/- 4.4 mmHg) in men with male pattern baldness. In controls, there was no significant difference in transcutaneous PO2 of frontal scalp (53.9 +/- 3.5 mmHg) and temporal scalp (61.4 +/- 2.7 mmHg). Transcutaneous PO2 also was significantly lower in the frontal scalp of male pattern baldness subjects (32.2 +/- 2.0 mmHg) than in either frontal or temporal scalp of controls (53.9 +/- 3.5 mmHg and 61.4 +/- 2.7 mmHg, respectively). There is a relative microvascular insufficiency to regions of the scalp that lose hair in male pattern baldness. We have identified a previously unreported tissue hypoxia in bald scalp compared with hair-bearing scalp.
[h=1]The role of hypoxia in atherosclerosis.[/h]
Hultén LM,
Levin M.
[h=3]Source[/h]Sahlgrenska Center for Cardiovascular and Metabolic Research, Wallenberg Laboratory, University of Gothenburg, Sweden.
Lillemor.Mattsson@wlab.gu.se
[h=3]Abstract[/h][h=4]PURPOSE OF REVIEW:[/h]It is important to address the factors involved in the progression of atherosclerosis because advanced atherosclerotic lesions are prone to rupture, leading to disability or death. Hypoxic areas are known to be present in human atherosclerotic lesions, and lesion progression is associated with the formation of lipid-loaded macrophages and increased local inflammation. Here we summarize the role of hypoxia in the development of advanced atherosclerotic lesions by promoting lipid accumulation, inflammation, ATP depletion, and angiogenesis.
[h=4]RECENT FINDINGS:[/h]A recent study clearly demonstrated the presence of hypoxia in macrophage-rich regions of advanced human carotid atherosclerotic lesions. We showed that hypoxia increases the formation of lipid droplets in macrophages and promotes increased secretion of inflammatory mediators, and recent evidence indicates that lipid droplets may play a role in mediating the inflammatory response. Hypoxia also promotes lesion progression by exacerbating ATP depletion and lactate accumulation, and the presence of hypoxia in human carotid atherosclerotic lesions correlates with angiogenesis.
[h=4]SUMMARY:[/h]Recent studies indicate that hypoxia may play a key role in the progression to advanced lesions by promoting lipid accumulation, increased inflammation, ATP depletion, and angiogenesis. Further understanding of the effects of hypoxia in atherosclerotic lesions could indicate potential therapeutic targets.
