Biomedical subjects

R Bohle

Publications and source records attributed to R Bohle.

4 recordsLinked to original sources

PubMed2004

[Increased signal intensity of velocity measurements in duplex sonography by using the contrast agent levovist: a prospective, randomized study in a fetal sheep model].

PURPOSE: To evaluate the potential diagnostic advantages of the contrast agent Levovist for signal enhancement of small adjoining fetal vessels and to study the effect of Levovist before and during acute fetal hypoxia on the fetal circulation and the fetal blood flow velocities. MATERIALS AND METHODS: A prospective, randomized study was performed in 12 fetal sheep before and during acute fetal hypoxia produced by complete occlusion of the maternal common iliac artery. Two groups of animals were studied, comprising animals with (study group, n = 6) and without (control group, n = 6) Levovist. In the study group, Levovist was administered intravenously by a pump (modified IVAC P 4000, Schering, Berlin). Duration and intensity of signal enhancement were measured in the fetal aorta, the common carotid artery and the ophthalmic artery of both groups before and during hypoxia. Concurrently, fetal heart rates as well as systolic and diastolic blood flow velocities in all three vessels were recorded in both groups. RESULTS: The increased signal intensity of up to 15 dB in the study group resulted in improved differentiation and imaging quality of adjoining small fetal vessels when compared with the control group. Neither before nor during acute hypoxia, significant differences of the fetal heart rate and the systolic and diastolic blood flow velocities were observed between the two groups (p > 0.05). In the study group, no emboli were caused by Levovist in any fetal tissue or in the placenta. CONCLUSION: The contrast agent Levovist improves the detection and accuracy of monitoring flow velocities in small fetal vessels by increasing the intensity of the Doppler signal without affecting fetal heart rate or fetal blood flow velocities.

Acute Disease↗

PubMed1996

Tumor necrosis factor-alpha in macrophages of heart, liver, kidney, and in the pituitary gland.

Tumor necrosis factor-alpha (TNFalpha) is an important mediator in bacterial lipopolysaccharide (LPS)-induced fever and shock. New data on TNFalpha-producing macrophages in heart, pituitary gland, kidneys and liver in correlation with TNFalpha plasma levels are reported here. In adult rabbits, core temperature and TNFalpha plasma levels are significantly increased at 3 and 24 h after treatment with LPS. After a delay of 6-12 h, the number of TNFalpha-containing macrophages, determined by immunohistochemistry, increases more than fivefold in all organs investigated. With the exception of the pituitary gland, the increase in cell number is correlated with the degree of cellular injury, indicating the involvement of TNFalpha in LPS-induced organ damage that is accompanied by the synthesis of the cytokine. Cortisol levels also increase for at least 24 h after LPS treatment, show peak values 6 h after interleukin-1 treatment, and are unchanged after TNFalpha treatment, indicating the different effects of these factors on the hypothalamo-hypophyseal-adrenocortical axis. This study provides evidence that macrophageal TNFalpha of multi-organ origin is involved in LPS-induced tissue injury and supports the concept of a systemic inflammatory response syndrome. We also show for the first time that in the anterior lobe of the pituitary gland TNFalpha is a normal constituent in cells producing growth hormone but not ACTH. Moreover, most cells of the intermediate lobe are positive for TNFalpha.

Animals↗

PubMed1995

Differential expression of fibronectin splice variants, oncofetal glycosylated fibronectin and laminin isoforms in nodular palmar fibromatosis.

The tissue formation process in nodular palmar fibromatosis (Morbus Dupuytren) was investigated by the demonstration of fibronectin splice variants (ED-A and ED-B fibronectin), de novo glycosylated fibronectin and laminin isoforms (A, M, B1, B2, s chains) in association to the proliferative activity (Ki-67 antigen) and the occurrence of myofibroblast phenotype (alpha-smooth muscle actin, desmin). The proliferative noduli of the fibromatosis were characterized by a diffuse immunostaining for alpha-smooth muscle actin, and single cells positive for desmin and the Ki-67 antigen. In contrast to the surrounding aponeurosis as extracellular matrix, components of the whole proliferative noduli were defined: ED-A, ED-B and de novo glycosylated fibronectin, B1 and B2 laminin chain, tenascin and collagen type IV. The demonstration of the A and M laminin chain was restricted to a few cells of the proliferative noduli. S laminin could be visualized in the majority of palmar aponeurotic fibroblasts. As revealed by mRNA, in situ hybridization a de novo synthesis of fibronectin could only be detected within proliferative noduli. There is a positive correlation between the myofibroblast phenotype formation, cellular proliferation and the occurrence of ED-A and ED-B containing fibronectin, as well as de novo glycosylated fibronectin in Dupuytren's disease. The ultrastructural irregularities of myofibroblastic basal lamina and the heterogeneity of the myofibroblast phenotype are equivalent to the variability of laminin isoform immunostaining.

Alternative Splicing↗

PubMedDate not supplied

Elastosis and cancer.

Recently we have shown that the autofluorescence within or just outside of a malignant tumor is rather small or large resp. in comparison to healthy tissue when excited at 365 nm. Studies with unfixed, unstained cryosections of skin with melanomas have revealed bulky fiber-like structures with a high fluorescence intensity just outside of a malignant tumor. Using polarized light, the structures could be identified as elastic fibers. This was also confirmed by studies on arterial walls.

Aged↗