The inhibitory effect of platelets on fibrinolysis in diabetic patients

An overview of Argentine contributions to diabetes research in the decade of the 1990s

Argentina has a longstanding tradition of diabetes research, beginning with the seminal work of Prof. Bernardo A. Houssay, who was awarded the first Nobel Prize in Medical Sciences for his studies on the relationship between diabetes and pituitary function. Prof. Luis F. Leloir, who was also awarded the Nobel Prize for his work in carbohydrate metabolism, also inspired younger generations of biologists to work in the field of diabetes research. The aim of this paper is to provide a review of the contributions of Argentine researchers during the 1990s. This manuscript includes only reports of Argentine researchers working on diabetes in local laboratories and quoted in Medline. Thus, important contributions not reported in journals included in Medline or produced by Argentine researchers working abroad may have been omitted. The material consists of a brief description of clinical research (epidemiology and costs, metabolic control, associated risk factors, immunological aspects, and other clinical studies) and basic research (animal model with spontaneous diabetes, islet morphology and function in normal and pathological conditions, insulin action, metabolic disorders related to diabetes, and some miscellaneous effects related to drug-induced diabetes). Altogether, a broad idea of the continuous contribution of our national research to the international field of diabetes is provided, as well as a list of Argentine researchers and research centers devoted to the study of diabetes.

Altered lysis resistance of platelet-rich clots in patients with insulin-dependent diabetes mellitus

The fibrinolytic resistance of platelet-rich arterial thrombi received much attention. Clot lysis method was used to assess the in vitro fibrinolytic properties in diabetes mellitus. Platelet rich (PRP) clots were formed by addition of thrombin, and lysis was induced by tissue-plasminogen-activator. The coagulation and lysis was followed by the light scattering properties. A special pattern of good initial lysis followed by a second clotting phase was observed in more than half of insulin dependent diabetic patients, while a similar pattern of clot-lysis was only occasionally found in non-insulin dependent diabetes mellitus or in the healthy control group. Following the thrombin activation of washed, gel-filtered platelets, the supernatants possessed an inhibitory action on in vitro lysis of PPP-clots. This suppression was remarkably stronger in IDDM, along with the highest PAI-1 activity concentration ratio of the platelet lysates, compared to plasmatic levels. The relation of this special type of PRP clot-lysis resistance to diabetic vascular complications needs further clarifying and investigations.