Hyperspectral imaging for monitoring oxygen saturation levels during normothermic kidney perfusion

The development of improved preservation techniques and the reliable assessment of donor grafts are main fields of research in transplantation medicine. Normothermic machine perfusion (NMP) is a promising alternative to static cold storage of organs, maintaining physiological conditions during preservation. In combination with NMP, we introduce hyperspectral imaging (HSI) as a novel approach for the monitoring of physiological kidney parameters. A line-scan HSI camera system was used to record images of porcine kidneys during NMP. Based on a dual-wavelength algorithm, the oxygen saturation levels were calculated from HSI recordings. Furthermore, we observed HSI images in the near-infrared (NIR) range in order to detect water characteristics of the kidney tissue. We found increasing levels of oxygenation during NMP and could discriminate between perfused and non-perfused areas. Cysts at the renal capsula were characterized by an absorption increase in the NIR band. Within this work, we showed that HSI is able to detect relevant chemical changes during NMP and allows the identification of pathologic variations

Terguride ameliorates monocrotaline induced pulmonary hypertension in rats

BACKGROUND: Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by vasoconstriction and remodeling of the pulmonary vasculature. The serotonin (5-hydroxytryptamine [5-HT]) pathway has been shown to play a major role in the pathogenesis of PAH, but pharmacological modulation of this pathway for treatment of pulmonary arterial hypertension is to date at preclinical level. Terguride is a 5-HT receptor (5-HTR) antagonist which is well tolerated and clinically approved for ovulation disorders. METHODS and RESULTS: Immunohistochemistry against 5-HT2A/B receptors on human lungs revealed their localization to vascular smooth muscle layer and quantitative RT-PCR showed 5-HTR2B up regulation in pulmonary artery smooth muscle cells (PASMC) isolated from PAH patients. Proliferation and migration of cultured primary human PASMC were dose-dependently blocked by terguride. Therapeutic 5-HT signaling inhibition was first demonstrated in isolated ventilated and perfused rat lungs and second by chronic terguride treatment of rats with monocrotaline-induced pulmonary hypertension in a preventive or curative approach. CONCLUSION: Terguride inhibited proliferation of pulmonary artery smooth muscle cells and abolished 5-HT induced pulmonary vasoconstriction. Chronic terguride treatment prevented dose-dependently the development and progression of MCT-induced PAH in rats. Thus, terguride represents a valuable novel therapeutic approach in PAH