Pericapillary Cuffs Research Articles

Role of "fibrin" cuffs in chronic nonspecific oral ulceration.

We report the novel finding of matrix-rich "fibrin" cuffs in chronic nonspecific oral ulceration and propose a possible role for these lesions. Pericapillary cuffs are typically found in chronic venous ulceration. Vascular cuffs, which form in the base and margins of leg ulcers, have been reported to contain fibrin, laminin, fibronectin, tenascin, and types I and III collagen. Histologically identical vascular cuffs are present in oral ulcers of unusually prolonged chronicity and their occurrence in the oral cavity suggests that chronic venous insufficiency and back pressure are not essential to their formation. It is proposed that the matrix-rich pericapillary cuffs may act as a scaffold for angiogenesis in ulceration of prolonged duration.

Venous hypertension of the hand caused by hemodialysis shunt: immunofluorescence studies of pericapillary cuffs.

Venous hypertension of the hand is an unusual complication of an arteriovenous shunt in patients receiving dialysis. We investigated whether in venous hypertension of the hand pericapillary cuffs are present and whether they consist of fibrin and other components. Biopsy specimens were taken from three patients with a side-to-side shunt and venous hypertension of the hand, from three patients with an end-to-side shunt without venous hypertension, and from three control subjects. The specimens were stained with antibodies against fibrinogen, fibrin, plasminogen activator inhibitor-I, factor VIII-related antigen, and collagen type IV. Pericapillary cuffs consisting of fibrin only were observed in patients with venous hypertension of the hand. In this fibrin network, factor VIII-related antigen and collagen type IV were also present. The finding of plasminogen activator inhibitor-I in the pericapillary cuff in the patient with the most severe signs of venous hypertension may indicate that breakdown of this fibrin cuff is impaired. Pericapillary cuffs may be of pathogenetic significance in venous hypertension of the hand.

Oxygen Diffusion in Oedematous Tissue and through Pericapillary Cuffs

The effect of oedema upon the diffusion of oxygen from capillary blood into the surrounding metabolizing tissue is considered in calculations based on the Krogh-Erlang model. While diffusion distances are increased in oedema, the oxygen consumption per unit volume of tissue is correspondingly reduced and the increments of capillary Po2 necessary to meet the tissue oxygen requirements are small. Pericapillary cuffs of oedema fluid would appear to have minimal effects on oxygen diffusion. It appears unlikely that pericapillary cuffs containing fibrin act as diffusion barriers to oxygen unless the fibrin molecules occupy more than half the volume of the cuff.

Tick‐bite meningoradiculoneuritis

We studied 10 adults with meningoradiculitis several weeks after a tick bite (Ixodes). EMG evidence of denervation was associated with normal motor conduction velocities, prolongation of distal latencies, and low sensory amplitudes, suggesting axonal neuropathy. Sural nerve biopsies confirmed the axonal involvement. Infiltrations of lymphocytes and plasma cells, sometimes forming thick pericapillary cuffs with no accompanying necrosis of vessel walls, were numerous. Many capillaries of the endoneurium, perineurium, and epineurium were affected in this way.