Retinal capillary nonperfusion results in neovascularization of the eye, which is restricted to the retina in less severe cases and progresses to the anterior chamber and the iris angle in the most advanced case, called rubeosis. This angioneogenesis may be induced by the release of retinal growth factors into the vitreous. This study compared levels of the IGF-I and IGF-II, and of the IGF binding protein-2 (IGFBP-2) and IGFBP-3 in vitreous from three groups with different degrees ofretinal ischemia, as judged by the extent of neovascularization: a control group without new vessel formation, retinal neovascularization in patients with proliferative diabetic retinopathy, and massive ischemia of various causes resulting in rubeosis. IGF-I and IGFBP-3 were increased 10-and 13-fold in rubeosis (P < 0.01 ) compared with no ischemia (n = 10), while IGF-II and IGFBP-2 were elevated 2.7-and 4.3-fold (P < 0.01). Within the rubeosis group similar changes were observed independently of the cause of ischemia, which was central vein occlusion, ischemic ophthalmopathy, or intraocular tumor in seven cases and diabetic retinopathy in three samples from two patients. Vitreous from patients with proliferative diabetic retinopathy but without rubeosis (n = 16) contained 2.5-and 2.2-fold elevated levels of IGF-I and of IGFBP-2 (P < 0.05), while IGF-II and IGFBP-3 were increased 1.4-and 1.6-fold, which was not significant. We conclude that: (a) ischemia appears to be a strong stimulus for the local production of IGF-I and -II and of IGFBP-2 and -3 in the eye. (b) Changes in IGF-I and IGFBP-2 in proliferative diabetic retinopathy may be secondary to local ischemia rather than being specific for diabetic retinopathy. (c) IGF-I and IGFBP-3 may play a role in mediating angioneogenesis in the eye. (J. Clin. Invest. 1993Invest. .92:2620Invest. -2625
Significantly elevated concentrations of PDGF AB were found in the vitreous of patients with proliferative diabetic retinopathy, with higher levels in individuals with additional rubeosis iridis compared to controls. However, concentrations of PDGF AB were also elevated in ischemic non-diabetic retinopathy, supporting the concept that ischemia might be a strong stimulator of growth factor production in the retina. Platelet factor 4 was not detectable in any of the vitreous samples included in the study. In summary, our results indicate that the growth factor PDGF plays an important role in the pathogenesis of proliferative diabetic retinopathy, probably in synergistic action with other growth factors like IGF I, IGF II, VEGF and TNF alpha.
Starting from the psychosomatic patients in clinico-medical wards and the inherent two primary alexithymic features ‘highly limited introspective capacity’ and ‘very low motivation concerning dynamic psychotherapy’, which we proved empirically, we describe the therapist’s attitude and the three steps of supportive psychotherapy which initially represent the most indicated procedure in this patient group. In Hannover, this supportive psychotherapeutic procedure is applied by student auxiliary therapists. On the basis of our empirical findings, the effectivity of supportive psychotherapy, accomplished by students, in the alexithymic psychosomatic clinico-medical inpatients could be clearly demonstrated. Furthermore, we comment on some previous psychotherapeutic findings with regard to Crohn patients. Starting from our pretreatment and our follow-up measurements, we were able to prove that patients who were treated by both supportive psychotherapy and psychoanalytically orientated inpatient ward psychotherapy, showed remarkable improvements at all levels of the measurement techniques. Finally, we outline some clinico-psychosomatic aspects with regard to secondary alexithymia.
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