Biomedical subjects

O Bamisedun

Publications and source records attributed to O Bamisedun.

4 recordsLinked to original sources

PubMed1992

Diabetic cutaneous microangiopathy.

PURPOSE: To determine a potential relationship between skin blood flow changes and the duration of diabetes and the presence of other microvascular complications. PATIENTS AND METHODS: Skin blood flow was measured by laser Doppler techniques at the finger and toe pulps, areas of predominant arteriovenous anastomotic (AVA) flow, and on the finger and toe dorsums, which have a greater nutritive microvascular contribution, in 83 diabetic patients and 39 nondiabetic control subjects. The average duration of diabetes was 14 +/- 1 years. Thirty-four patients had retinopathy. Eighteen patients had proteinuria. Forty patients had definite signs and symptoms of neuropathy, whereas 11 had no detectable neuropathy. RESULTS: There was little difference between diabetic and nondiabetic skin blood flow at normal body temperatures. However, at an elevated skin temperature of 44 degrees C, significant reductions in skin blood flow versus control were demonstrated in the diabetic group. Skin blood flow at finger and toe dorsums showed a decrease as a function of the duration of diabetes. In contrast, there was little, if any, relationship between the duration of diabetes and skin blood flow at the finger and toe pulps. Diabetic patients with retinopathy had significantly lower blood flow at both finger and toe dorsums than those without retinopathy. Even excluding patients with recent onset of diabetes from the analysis, flows at finger (18.6 +/- 2.0 mL/min/100 g) and toe dorsums (11.2 +/- 1.4 mL/min/100 g) in the patients with retinopathy were significantly lower than in diabetic patients without retinopathy [finger: 28.6 +/- 2.7 mL/min/100 g (p < 0.01) and toe: 15.1 +/- 1.5 mL/min/100 g (p < 0.05)]. The presence of proteinuria was also associated with lower blood flow at the toe dorsum. There were no differences between patients with or without clinical diabetic neuropathy. At finger and toe pulps, there were no significant differences between diabetic patients with or without retinopathy, proteinuria, or neuropathy. CONCLUSIONS: There appears to be a diabetic cutaneous microangiopathy that coexists with diabetic retinal and renal microvascular disease. This process is expressed primarily at sites of nutritive microvasculature. The ability to use the skin as a model for diabetic microangiopathy would have great practical importance, both experimentally and in clinical practice.

Adult↗

PubMed1992

Current perception thresholds in ageing.

We studied 40 healthy elderly and 31 healthy young volunteers and 25 elderly diabetic and 37 young diabetic patients. All subjects received detailed neurological examinations focusing particularly on sensory symptom and physical evaluations. Standardized assessment of symptoms and physical testing of light touch, pain, vibratory and thermal sensation were performed at the hand, wrist, elbow, foot, ankle and knee. The total symptom score (SS) and the total physical score (PS) were defined by summing test scores at each site. Current perception threshold (CPT) testing using constant current sine wave alternating current was completed at the same anatomical sites. CPT findings did not differ significantly between young and old healthy subjects. Older diabetic patients had higher CPTs than younger diabetic patients, but the severity of clinical diabetic neuropathy was greater in the older group. CPTs correlated with the degree of clinical diabetic neuropathy (r = 0.47 with SS and r = 0.60 with PS) rather than with age (r = 0.12). We conclude that current perception does not decline with age. Nor does ageing by itself worsen CPT values in patients with neuropathy. CPT testing is easily performed, clinically applicable and the first objective sensory measure not affected by the process of ageing.

Adult↗

PubMed1992

The laser Doppler analysis of posturally induced changes in skin blood flow at elevated temperatures.

Recently, it has become possible to use laser Doppler techniques to separately quantitate the two components of blood flow, microvascular volume and red blood cell velocity. We used these techniques in 21 normal volunteers to quantitate the effect of postural changes in skin blood flow and its components at 35 degrees C and at 44 degrees C. Postural skin blood flow changes have ben studied extensively at basal skin temperature, but not at elevated temperatures. We contrasted changes at sites with arteriovenous anastomotic (AVA) blood flow (toe and finger pulps) with changes at sites with primarily nutritive flow (elbow and knee). Skin blood flow increased markedly with increasing temperature. The increases at the elbow and knee were the products of equivalent increases in both microvascular volume and velocity. In contrast, the increases on the finger and toe pulps were mainly due to increases in velocity. Elevation of both upper and lower extremities brought about a decrease in skin blood flow. Dependency increased blood flow. The magnitudes of observed changes were greater on the lower extremity than on the upper extremity and greater at 44 degrees C than at 35 degrees C. Once again, with postural change, the nutritive areas exhibited similar changes in volume and velocity while the AVA areas primarily showed velocity alterations. The correlation of systolic pulse pressures with blood flow was greater at the AVA areas than at nutritive areas and greater at 44 degrees C than at 35 degrees C. This correlation was with the velocity rather than with the volume component.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Skin blood flow and current perception in pentoxifylline-treated diabetic neuropathy.

There are several anecdotal reports of improvement in diabetic sensory neuropathy following a course of pentoxifylline therapy. Pentoxifylline theoretically could improve skin blood flow, thus reducing ischemia at axonal endings. The authors used laser Doppler techniques to measure skin blood flow and measured sine wave current perception thresholds (CPTs) in pentoxifylline-treated diabetic patients with sensory neuropathy. Twenty-four patients completed a six-month course of treatment. These patients had a predominantly "stocking" neuropathy; all the major abnormalities on clinical, laser Doppler, and current perception testing were found on the lower extremity. Seventeen of the 24 patients reported symptomatic improvement. A careful, graded neurologic examination confirmed that improvement, with a decrease in symptom score on the lower extremity (SSDW) from a baseline of 5.0 +/- 0.7 to 3.5 +/- 0.7 (p < 0.01) and of physical score (PSDW) from baseline 22.0 +/- 2.0 to 16.0 +/- 1.9 (p < 0.01) after six months. On the lower extremity, there was an increase in laser Doppler measured flow score (FS) both at 35 degrees and at 44 degrees C. FSDW (35 degrees) increased from 10 +/- 2 to 14 +/- 3 at six months (p < 0.05). FSDW (44 degrees) increased from 58 +/- 5 to 77 +/- 7 at six months (p < 0.01). There was an improvement in sine wave current perception measured by current perception threshold score (TS). TSDW dropped from 150 +/- 32 to 84 +/- 28 at six months (p < 0.03). In patients with diabetic sensory neuropathy, pentoxifylline appears to improve skin blood flow. Current perception thresholds improve in tandem, corroborating improvement in clinical neurologic findings.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗