No abstract

Vitreous from patients with proliferative diabetic retinopathy contains an angiogenic substance which stimulates the proliferation of blood vessels on the chick chorioallantoic membrane, whereas vitreous from non-diabetics who do not have a proliferative retinopathy does not.

SCHULTETUS RR, HILL CR, DHARAMRAJ CM, BANNER TE, BERMAN LS. Wakefulness during cesarean section after anesthetic induction with ketamine, thiopental, or ketamine and thiopental combined. Anesth Analg 1986;65:723-8.Thirty-six pregnant women ( A S A class 1 or 11) at term who underwent general anesthesia and cesarean section received either ketamine, 1 mglkg ( n = 12); thiopental, 4 mglkg ( n = 13); or a combination of ketamine, 0.5 mglkg, and thiopental, 2 mglkg ( n = 11). A blood pressure cuff inflated to 250 mm Hg isolated one arm from the effects of succinylcholine so that awareness during anesthesia could be assessed by asking the patient to move her hand. Although only one patient receiving ketamine responded to commands during anesthesia, 46% of patients receiving either thiopental or the combination responded to commands intraoperatively. No patient hallucinated, the incidence of dreams was low (11%), and no postoperative dysphoria was noted. Three patients (8%) had postoperative recall of intraoperative awareness; one had received thiopental and two the combination. Maternal intraoperative cardiovascular responses among the groups were similar, as were umbilical blood gas values, newborn Apgar scores, and neonatal neurobehavioral test scores at 4 and 24 hr. Ketamine more effectively blocked maternal responsiveness to commands and strong stimuli during the first few minutes after anesthetic induction for cesarean section than did thiopental or a combination of thiopenfal and ketamine, each at a lower dose.

Avascular tumours have the ability to establish a blood supply for themselves by secreting a humoral factor which stimulates their host's endothelial cells to proliferate and to migrate towards the tumour source. The mechanism of action of such a humoral angiogenesis factor is more than that of an endothelial-cell growth factor since it requires an oriented migration of cells towards the tumour. We report here the activation of pure skin-fibroblast procollagenase by a low-molecular-weight angiogenesis factor capable of stimulating endothelial-cell growth in vitro. The activation was observed when either Type I or III collagen was used as substrate. It is suggested that at least one function of angiogenesis factor is to promote limited degradation of the connective tissue through which it passes causing channeling in the matrix along which stimulated endothelial cells may migrate.