Loss of the extremity despite patent vascular reconstruction

This retrospective study concerns 8 patients, who had successful vascular reconstruction for ischaemia of a lower extremity but nevertheless needed lower or upper leg amputation. The analysis shows that in four patients (one of them diabetic) misjudgement was the cause of failure. The other four patients all had diabetic angiopathy. No misjudgement or wrong decision was found in the analysis of their case. Here the failure is interpreted as the fatal destiny of a seriously damaged microangiopathic extremity.     

Red Cell Ageing and Death

To obtain red cell populations of increasing mean age erythropoiesis was arrested through continuous actinomycin treatment or maintained transfusion polycythemia in mice and rats respectively. The parameters studied included cell indices, enzyme activities and rheological characteristics. Further, the life-span of aged cells was compared to normal, and the sequestration site was determined. Mice erythrocytes, like those of rats, exerienced a continuous decrease in MCV1, an early rise in MCHC, and late MCH reduction. In ageing rat erythrocytes the activities of HK, GR and 6-PGD did not fall below the normal range during the first 9 tenths of the potential life-span. On the other hand, a borderline reduction of PK activity was found, and the activity of G-6PD underwent a steady though unimpressive decrease to 70% of the physiological average. Aged erythrocytes, forced through 15-mum capillaries differed in apparent viscosity from reticulocytes and normal cells by a factor of 1.31 and 1.16, respectively. Destruction of senescent cells was predominantly confined to the spleen, and prolonged erythrocyte survival followed splenectomy.     

Maturation of the Macroreticulocyte

With anaemia the erythroid marrow maturation pattern of the rat is altered so that macroreticulocytes containing increased amounts of haemoglobin, water, ribosomes and ribonucleic acid are released into circulation. This was shown to be accompanied by a reduction in the marrow iron transit time, a measurement of the maturation time of marrow reticulocytes, and possibly by the occurrence of skipped mitoses during maturation. Despite the premature release, increased volume and haemoglobin content of these macroreticulocytes, they matured normally without apparent splenic sequestration or significant cell death in the first 10 days. At the same time they underwent shrinkage by loss of both cell water and some haemoglobin. This appeared to be an intravascular phenomenon where macrocytes were remodelled, possibly by cell fragmentation, until a population with near normal indices was obtained.