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.