Skin perfusion pressure of the foot is a good substitute for toe pressure in the assessment of limb ischemia

PURPOSE

Noninvasive measurements of limb systolic pressures are used routinely in the assessment of the severity of peripheral arterial disease, including the evaluation for critical limb ischemia. However, ankle pressures cannot be measured reliably in patients with medial calcification, which is especially common among patients with diabetes. Skin lesions on the toes or previous digital amputations may preclude the measurement of toe pressures. Measurements of skin perfusion pressure (SPP) are not subject to such limitations and were shown to be useful in the assessment of the severity of peripheral arterial disease. Because toe pressure is often used in the evaluation of severity of arterial disease and in the assessment for critical ischemia, we undertook to study whether there is a sufficient correlation between toe pressure and foot SPP that would allow the use of SPP measurements when toe pressures cannot be measured.

METHODS

Measurements were carried out in 85 limbs of 71 patients referred to the vascular laboratory for evaluation for peripheral arterial disease. Diabetes mellitus was present in 43 patients. Each patient had foot SPP and toe pressure measurements. Toe pressures measured with photoplethysmography were correlated with foot SPP measured with laser Doppler scanning.

RESULTS

There was a strong linear correlation between SPP and toe pressure (r = 0.87; P <.01). Also, significant correlation was found in both the patients with diabetes and the patients without diabetes (r = 0.85 and 0.93, respectively; P <.01 in both cases).

CONCLUSIONS

We concluded that SPP measured in the foot correlates well with toe pressure and can be substituted for toe pressure measurement in patients in whom toe pressures cannot be measured.

Discordant effects of butyrate analogues on erythroleukemia cell proliferation, differentiation and histone deacetylase

Actions of butyrate and structural analogues on histone deacetylase activity were compared with effects on proliferation and differentiation of erythroleukemia cells. Proliferation was inhibited by 5 mM tert- butylacetate, phenylacetate, phenylbutyrate, 3-bromopropionate and ethyl butyrate without induction of hemoglobin synthesis. n - Butyramide was a stronger inhibitor of cell proliferation and a more effective inducer of hemoglobin synthesis than isobutyramide. The data from combination studies were compatible with butyramide and isobutyramide being weaker agonists that competed for a common site with butyrate. Butyramide and isobutyramide were weaker inhibitors of histone deacetylase than 4-phenylbutyrate and phenylacetate, which in turn were less effective than 3-bromopropionate and butyrate. Butyrate and analogues had similar inhibitory effects on histone deacetylase activity in nuclei from mouse DS19 cells and human K562 cells. Effects on histone deacetylase did not show a consistent correlation with inhibition of cell proliferation or induction of hemoglobin synthesis.