Calf pump function in patients with healed venous ulcers is not improved by surgery to the communicating veins or by elastic stockings

Calf muscle pump function was assessed in 41 limbs after venous ulcers had healed. Treatment was then randomized either to ligation of incompetent lower leg communicating veins and ablation of incompetent superficial veins combined with permanent graduated compression elastic stockings, or to graduated compression elastic stockings only. Half volume refilling time (TV1/2) and relative expelled volume (EVrel) measured on foot volume plethysmography were used to assess calf muscle pump function. This was repeated after 12 months. The initial TV1/2 and EVrel were significantly lower than for normal limbs. There was no significant improvement in TV1/2 in either treatment group (Student's t test, P = 0.78, P = 0.19). EVrel did not improve significantly in limbs treated with elastic stockings alone (P = 0.94), but there was a slight but significant improvement in EVrel in limbs treated with surgery and elastic stockings (P = 0.048); however, this was still significantly below the normal range (P less than 0.001). In limbs without phlebographic evidence of post-thrombotic changes, treated with the combination of surgery and elastic stockings, there was a significant improvement in EVrel (P = 0.035), but no improvement was found in limbs with post-thrombotic changes. This small but significant improvement in EVrel in limbs without post-thrombotic changes treated by surgery and elastic stockings may explain the reduced incidence of reulceration that has been found following surgical eradication of the superficial and communicating veins.

Changes in the apparently normal limb in unilateral venous ulceration

Forty-seven patients with unilateral venous ulceration have been investigated to determine if any abnormalities were present in the contralateral limbs which had not had lipodermatosclerosis or ulceration. Ascending phlebography in the non-ulcerated limbs showed post-thrombotic changes in 28 per cent and incompetent lower leg communicating veins in 19 per cent. This incidence was not significantly different to the limbs with healed ulceration (45 and 23 per cent respectively, chi 2 test, P = 0.10). Half volume refilling time measured by foot volumetry suggested that 79 per cent of the non-ulcerated limbs had evidence of deep vein incompetence or incompetent lower leg communicating veins, which was again similar to the incidence in the previously ulcerated limbs (85 per cent). Transcutaneous oxygen readings, expressed as a ratio of a reading at a standard site in the gaiter region of the leg over a reading from the upper arm, were significantly lower in non-ulcerated limbs (mean 0.84 +/- 0.26 s.d.) than in a cohort of age and sex matched controls (mean 1.02 +/- 0.14, Student's t test, P less than 0.001), and significantly higher than in previously ulcerated limbs (mean 0.68 +/- 0.31, P less than 0.01). Abnormalities in venous anatomy and function have been shown, in conjunction with evidence of reduced oxygen diffusion, through the gaiter skin before overt skin changes develop.

Tissue plasminogen activators in breast cancer

Increased levels of tissue fibrinolytic activity have been detected in some malignant tumours and they have been implicated in metastatic spread. We have investigated tissue plasminogen activator (tPA) and urokinase (UK) in 26 breast carcinomas and 13 benign breast biopsies. Tissue extracts were analysed for overall fibrinolytic activity on fibrin plates and by fibrin-overlay zymography after electrophoresis on SDS-PAG. Supernatants of the extracts were analysed by an antigenic immunoassay (ELISA) and a functional bioimmunoassay (BIA) using polyclonal antibodies. Total ELISA and BIA results correlated (P less than 0.001) and all the tissues contained similar tPA levels. Malignant extracts contained significantly increased UK compared with benign extracts (1.60 +/- 0.37 iu, 0.36 +/- 0.16 iu; P less than 0.002). Zymography showed no high molecular weight inhibitor complexes and UK was almost exclusively confined to the malignant tissues (P much less than 0.02). The results suggest that malignant transformation of breast tissue is associated with the significantly increased production of UK. This may be responsible for the characteristics of malignancy or it may be a growth factor.

A study of the mechanical properties of fresh and preserved human femoral vein wall and valve cusps

In the hope that some varieties of the post-phlebitic syndrome might be treated by implanting a preserved vein valve, studies have been made of the mechanical properties of vein valves and vein wall before and after preservation with glutaraldehyde. The ultimate tensile strength (breaking stress) and strain (extensibility) of strips of vein wall and valve leaflet were measured with a Nene tensiometer. The ultimate tensile strength of valve leaflet was found to be twice that of vein wall. Preservation in glutaraldehyde (0.2 per cent, pH 7.4, for 7 days) with valve cusps closed by a minimum head of pressure caused no change in breaking stress or extensibility.

Abnormal fibrinolysis: the cause of lipodermatosclerosis or "chronic cellulitis" in patients with primary lymphedema

Blood fibrinolytic activity was measured in 20 patients with primary lymphedema, ten without and ten with skin changes usually attributed to "chronic cellulitis". The patients with abnormal skin showed reduced fibrinolytic activity, a finding previously described in patients with chronic venous disease and lipodermatosclerosis . It is postulated that changes of "chronic cellulitis" are identical to lipodermatosclerosis and are produced by a similar mechanism, namely reduced fibrinolysis.

Specific B lymphocyte suppression by infectious bursal agent (Gumboro disease virus) in chickens

Chickens infected experimentally with infectious bursal agent (IBA) during embryonation or early after hatching show a severe depression of bursa-dependent lymphoid components, and associated immune functions. Data presented here and elsewhere show that the degree of B cell suppression correlates with the time of infection. This would be compatible with a virus-induced block in B lymphocyte differentiation. Accordingly, the virus may be cytopathic for early (bursal) but not late (circulating) B lymphocytes or, more likely, the virus inactivates those non-lymphoid bursal cells mediating lymphocyte differentiation.

Preliminary characterisation of paramyxovirus isolated from a parrot

A virus, designated 0121, which was isolated from a parrot, was shown to be a paramyxovirus, which was serologically related to the paramyxoviruses Bangor/flinch/N. Ireland/73 (Bangor) and Yucaipa/chicken/California/60(PMY). However, the 0121 virus differed in several properties from both the PMY and the Bangor viruses. The virus was not pathogenic for chickens. I was designated Paramyxovirus: Parrot/England/0121/74.

Infectious bursal disease agent: morphology by negative stain electron microscopy

The virus of infectious bursal disease of chickens was studied by immune electron microscopy. Negatively-stained preparations revealed morphological similarities with both the bluetongue virus group, and the virus of infectious pancreatic necrosis of trout. Results indicated that the small particle found in such preparations is a degradation product of the large particle.

A case of polytetrafluoroethylene poisoning in cockatiels accompanied by polymer fume fever in the owner

Five cocatiels (Nymphicus hollandicus) died within 30 minutes following exposure to fumes from a frying pan coated with the "non-stick" plastic polytetrafluoroethylene (PTFE) that had accidentally overheated. Within an hour the owner developed symptoms of "polymer fume fever" but recovered in the next 24 hours. Clinical signs and post mortem lesions of the cockatiels are described and reference is made to the unusual susceptibility of parakeets to the pyrolysis products of frying pans coated with PTFE.