Alexander Kuhlmann

Endothelin-1 and ETA/ETB receptor protein and mRNA: expression in normal and vascularized human corneas.

Purpose: Neovascularization of the cornea causes blindness and increases the risk of immune rejections after keratoplasty. The purpose of this study was to investigate involvement of the potent angiogenic growth factor endothelin (ET)-1 and its receptors, ETA and ETB, in corneal neovascularization. Methods: ET-1, ETA, and ETB receptor protein expression was evaluated in nonvascularized and vascularized human corneas by immunohistochemistry. Epithelial ET-1 protein expression of both groups was compared using a semiquantitative scoring system. Double immunofluorescence was used to colocalize ETA and ETB receptor with CD31. In situ hybridization and immunoelectron microscopy analyzed ET-1 and its receptors in normal and vascularized corneas. Results: Nonvascularized corneas displayed ET-1 and ETA/ETB receptor protein and mRNA in epithelial and some corneal endothelial cells. ETA more than ETB receptors were expressed on some keratocytes. In vascularized corneas, ET-1 and ETA/ETB receptor expression was found in the endothelial lining of new blood vessels (as shown by CD31-colocalization). ET-1 protein expression was significantly increased in the epithelium of vascularized corneas (P < 0.001). Immunogold localized ET-1 and its receptors to the nuclear/perinuclear space and to the luminal side of endothelial cells of new blood vessels. Conclusions: In corneal neovascularization, ET-1 protein and mRNA expression is upregulated in epithelial cells. Together with ET-1, ETA, and ETB receptor expression on endothelial cells of ingrown new blood vessels, this points to an involvement of ET-1 and its receptors in corneal angiogenesis. As potent ETA and ETB receptors are available, the endothelin system may represent an additional target for corneal antiangiogenic therapy.

Occlusion of coronary aneurysms demonstrated by multidetector-row computed tomography

Sirs: A-55-year male was admitted because of a round calcification in the area of the heart in a chest X-ray. He was asymptomatic and did not have history of congenital abnormality or coronary intervention. ECG did not show any abnormality. The thallium-201 exercise scintigram showed redistribution in the anterior, apex, and inferior left ventricular segments, indicating ischemia in the right coronary artery and left anterior descending territories. The patient was suspected of having asymptomatic coronary heart disease. Thus, multidetector-row computed tomography (MDCT) was performed using a LightSpeed 16 (GE Systems, USA) with the slice thickness of 0.625 mm; pitch of 0.3: 1; gantry rota

Analysis of Protein Distribution in Cartilage Using Immunofluorescence and Laser Confocal Scanning Microscopy

Protein localization in cartilage sections by antibodies that specifically bind to epitopes of a protein is one of the most powerful technologies in modern cartilage research. Studies using two or more primary antibodies that recognize different protein epitopes allow the colocalization of different gene products in one cartilage section. In addition, specific histochemical stains help to visualize nuclear DNA, mitochondria, and other subcellular compartments. By these immunohistological methods, the distribution of proteins can be analyzed throughout different zones of articular cartilage. In particular, with the use of laser scanning confocal microscopy, subcellular localization of proteins can also be determined (i.e, nuclear, cytoplasmic, membrane-associated, and extracellular). Overall, immunohistochemical methods are fairly simple to handle, and the reagents required are inexpensive, with the exception of basic technical equipment (fluorescence microscope or confocal microscope). However, as with many methodologies, technical knowledge and experience is important to avoid and/or interpret either false-positive or false-negative results.

Giant True Aneurysms of Saphenous Vein Bypass Grafts A Rare Cause of Tumor-Like Mediastinal Masses

A 69-year-old man, who had been asymptomatic for 12 years after aorto-coronary venous bypass surgery, was admitted for the evaluation of a large mass adjacent to the left heart border detected by routine chest radiography (Figure 1). Further diagnostic evaluation included a contrast-enhanced multi-detector row spiral computed tomography scan of the chest that revealed a large left anterior mediastinal mass abutting the left ventricle, right ventricle, and pulmonary artery (Figure 2). In addition, a second mass adjacent to the ascending aorta and the right atrium was detected. Both structures were partly filled with contrast agent, confirming their vascular nature. On the basis of these findings, giant aneurysms of …A 69-year-old man, who had been asymptomatic for 12 years after aorto-coronary venous bypass surgery, was admitted for the evaluation of a large mass adjacent to the left heart border detected by routine chest radiography (Figure 1). Further diagnostic evaluation included a contrast-enhanced multi-detector row spiral computed tomography scan of the chest that revealed a large left anterior mediastinal mass abutting the left ventricle, right ventricle, and pulmonary artery (Figure 2). In addition, a second mass adjacent to the ascending aorta and the right atrium was detected. Both structures were partly filled with contrast agent, confirming their vascular nature. On the basis of these findings, giant aneurysms of …

Giant True Aneurysms of Saphenous Vein Bypass Grafts

A 69-year-old man, who had been asymptomatic for 12 years after aorto-coronary venous bypass surgery, was admitted for the evaluation of a large mass adjacent to the left heart border detected by routine chest radiography (Figure 1). Further diagnostic evaluation included a contrast-enhanced multi-detector row spiral computed tomography scan of the chest that revealed a large left anterior mediastinal mass abutting the left ventricle, right ventricle, and pulmonary artery (Figure 2). In addition, a second mass adjacent to the ascending aorta and the right atrium was detected. Both structures were partly filled with contrast agent, confirming their vascular nature. On the basis of these findings, giant aneurysms of …A 69-year-old man, who had been asymptomatic for 12 years after aorto-coronary venous bypass surgery, was admitted for the evaluation of a large mass adjacent to the left heart border detected by routine chest radiography (Figure 1). Further diagnostic evaluation included a contrast-enhanced multi-detector row spiral computed tomography scan of the chest that revealed a large left anterior mediastinal mass abutting the left ventricle, right ventricle, and pulmonary artery (Figure 2). In addition, a second mass adjacent to the ascending aorta and the right atrium was detected. Both structures were partly filled with contrast agent, confirming their vascular nature. On the basis of these findings, giant aneurysms of …

Images in cardiovascular medicine. Giant true aneurysms of saphenous vein bypass grafts: a rare cause of tumor-like mediastinal masses.

A 69-year-old man, who had been asymptomatic for 12 years after aorto-coronary venous bypass surgery, was admitted for the evaluation of a large mass adjacent to the left heart border detected by routine chest radiography (Figure 1). Further diagnostic evaluation included a contrast-enhanced multi-detector row spiral computed tomography scan of the chest that revealed a large left anterior mediastinal mass abutting the left ventricle, right ventricle, and pulmonary artery (Figure 2). In addition, a second mass adjacent to the ascending aorta and the right atrium was detected. Both structures were partly filled with contrast agent, confirming their vascular nature. On the basis of these findings, giant aneurysms of …A 69-year-old man, who had been asymptomatic for 12 years after aorto-coronary venous bypass surgery, was admitted for the evaluation of a large mass adjacent to the left heart border detected by routine chest radiography (Figure 1). Further diagnostic evaluation included a contrast-enhanced multi-detector row spiral computed tomography scan of the chest that revealed a large left anterior mediastinal mass abutting the left ventricle, right ventricle, and pulmonary artery (Figure 2). In addition, a second mass adjacent to the ascending aorta and the right atrium was detected. Both structures were partly filled with contrast agent, confirming their vascular nature. On the basis of these findings, giant aneurysms of …