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Biomedical subjects

E Rohde

Publications and source records attributed to E Rohde.

At least 19 recordsLinked to original sources
PubMed1999

Megakaryocyte hyperplasia and enhanced agonist-induced platelet activation in vasodilator-stimulated phosphoprotein knockout mice.

Vasodilator-stimulated phosphoprotein (VASP), a substrate of cAMP- and cGMP-dependent protein kinases, is associated with focal adhesions, cell-cell contacts, microfilaments, and highly dynamic membrane regions. VASP, which is expressed in most cell types and in particularly high levels in human platelets, binds to profilin, zyxin, vinculin, F-actin, and the Listeria monocytogenes surface protein ActA. VASP is a member of the enabled (Ena)/VASP protein family and is thought to be involved in actin filament formation and integrin alphaIIbbeta3 inhibition in human platelets. To gain further insight into the in vivo function of this protein, VASP-deficient mice were generated by homologous recombination. VASP-/- mice demonstrated hyperplasia of megakaryocytes in bone marrow and spleen but exhibited no other macroscopic or microscopic abnormalities. Activation of platelets with thrombin induced a more than 2-fold higher surface expression of P-selectin and fibrinogen binding in VASP-deficient platelets in comparison to wild type. These data support the concept that VASP is a negative modulator of platelet and integrin alphaIIbbeta3 activation. Although the limited phenotypic differences between wild-type and VASP-/- mice suggested functional compensation of VASP by members of the Ena/VASP family, alterations in the expression levels of mammalian enabled (Mena) and Ena-VASP-like (Evl) protein were not detected. VASP-deficient mice may provide an interesting model system for diseases in which enhanced platelet activation plays a major role.

Animals↗
PubMed1999

[Investigation of adhesion molecules (sVCAM-1) in serum of nonpregnant women, normotensive pregnant women and in patients with pregnancy complications].

OBJECTIVE: An increased expression of endothelial adhesion molecules combined with neutrophil activation in the placental bed is to be assumed aetiopathogenetically relevant in preeclampsia. MATERIAL AND METHODS: Ranges of sVCAM-1 serum concentrations of both control persons (29 nonpregnant and 25 normotensive pregnant women) and patients with different complications of pregnancy (HELLP-syndrome n = 10, preeclampsia n = 12, gestational hypertension n = 38, diabetes n = 24, growth retardation n = 21) were determined by means of ELISA. Frozen placental samples of 5 normotensive and 10 hypertensive pregnant women were investigated immunhistochemically to study the distribution of VCAM-1 in the placenta. RESULTS: Significantly elevated sVCAM-1 serum levels (p < 0.05) were identified in samples of patients with HELLP syndrome, preeclampsia, diabetes and gestational hypertension compared with serum levels of normotensive pregnant women. The cut-off level (97.5% percentile of normotensive serum levels) was calculated (775 ng/ml). VCAM-1 was localized immunhistochemically at capillaries of villi and main villi. CONCLUSIONS: There are closed relations between elevated serum levels of sVCAM-1 during pregnancy and diseases with vasculopathies of placental bed.

Adult↗
PubMed1998

Protein analysis by membrane preconcentration-capillary electrophoresis: systematic evaluation of parameters affecting preconcentration and separation.

Fast and efficient analysis of proteins in physiological fluids is of great interest to researchers and clinicians alike. Capillary electrophoresis (CE) has proven to be a potentially valuable tool for the separation of proteins in specimens. However, a generally acknowledged drawback of this technique is the limited sample volumes which can be loaded onto the CE capillary which results in a poor concentration limit of detection. In addition, matrix components in samples may also interfere with separation and detection of analytes. Membrane preconcentration-CE (mPC-CE) has proved to be effective in overcoming these problems. In this report, we describe the systematic evaluation of parameters affecting on-line preconcentration/clean-up and separation of protein mixtures by mPC-CE. Method development was carried out with a standard mixture of proteins (lysozyme, myoglobin, carbonic anhydrase, and human serum albumin). First, using MALDI-TOF-MS, membrane materials with cation-exchange (R-SO3H) or hydrophobic (C2, C8, C18, SDB) characteristics were evaluated for their potential to retain proteins in mPC cartridges. Hydrophobic membranes were found most suitable for this application. Next, all mPC-CE analysis of protein samples were performed in polybrene coated capillaries and parameters affecting sample loading, washing and elution, such as the composition and volume of the elution solvent were investigated. Furthermore, to achieve optimal mPC-CE performance for the separation of protein mixtures parameters affecting postelution focusing and electrophoresis, including the composition of the background electrolyte and a trailing stacking buffer were varied. Optimal conditions for mPC-CE analysis of proteins using a C2 impregnated membrane preconcentration (mPC) cartridge were achieved with a background electrolyte of 5% acetic acid and 2 mM ammonium acetate, 60 nl of 80% acetonitrile in H2O as an elution solvent, and 60 nl of 0.5% ammonium hydroxide as a trailing stacking buffer. The developed method was used successfully to separate proteins in aqueous humor, which contains numerous proteins in a complex matrix of salts.

Aqueous Humor↗
PubMed1998

The analysis of fountain pen inks by capillary electrophoresis with ultraviolet/visible absorbance and laser-induced fluorescence detection.

Information on the identity of inks adds to the circumstantial evidence in legal cases involving fraudulent documents. In combination with optical methods, multiple thin-layer chromatography (TLC) is currently the analytical tool used by forensic chemists to separate, compare and distinguish inks based on their dye composition. In our studies, capillary electrophoresis (CE) was used for the analysis of water-soluble fountain pen inks. Inks are complex mixtures of synthetic organic and inorganic dyes, surfactants, resins and other components. The investigations included the development of an electrophoretic separation method, the optimization of an extraction procedure for inks from paper as well as the evaluation of ultraviolet/visible (UV/VIS) absorbance and laser-induced fluorescence (LIF) detection for the analysis of inks by CE. Good results for the separation of 17 blue and black inks of different manufacturers and countries of origin were obtained with 100 mM borate buffer, pH 8.0, containing 20% methanol. The electropherograms of the inks and their extracts from paper showed patterns that were in most cases distinctly different from each other. Ultraviolet/visible scans can be used to compare spectra of the separated main and trace components of inks. Fluorescence detection at different excitation and emission wavelengths was more sensitive, but added to the complexity of the electropherograms due to the excitation of coextracted fluorescing paper components. The resolution power of CE combined with the information content provided by the detection modes investigated prove CE to be a powerful tool for the identification of water-soluble inks used on paper documents.

Electrophoresis, Capillary↗
PubMed1998

Comparison of protein mixtures in aqueous humor by membrane preconcentration - capillary electrophoresis - mass spectrometry.

The significance of proteomic research is coupled with the recent exponential growth of these investigations. Currently, the most popular techniques used for these studies include the coupling of 1- and 2-dimensional electrophoresis with mass spectrometric analysis of the extracted and digested proteins. However, detection limits of gel staining methods have led to a search for complimentary techniques that afford the detection of lower concentrations of biologically relevant proteins. In the present studies, we have evaluated the applicability of on-line capillary electrophoresis - mass spectrometry (CE-MS) for this application. Specifically, we used membrane preconcentration-CE-MS (mPC-CE-MS) to analyze 13 samples of human aqueous humor (AH) from patients with various ocular pathologies (cataract, cataract plus glaucoma, and cataract plus pseudoexfoliation syndrome). This approach enabled rapid analysis of a relatively large volume (1 microL of each specimen, and a protein map for each was created. Measured average molecular weights (Mr) were used to tentatively identify proteins after search of the SWISS-PROT database using TagIdent from ExPaSy. Among those proteins tentatively identified are beta-2 microglobulin (Mr 11731.2), apolipoprotein A1 (Mr 28078.6) and serum albumin (Mr 66400). Proteins with Mr of 4349 (unidentified), 11731.2 (beta-2 microglobulin), 13400-14100 (immunoglobulin fragments), 28078.2 (apolipoprotein A1) and approximately 68000 (serum albumin) were observed in the majority of specimens. Generally no significant differences were noted in the protein composition of aqueous humor samples from different pathologies. However, the absence of an Mr 13345 protein and its oxidized form (Mr 13361) in samples from patients with pseudoexfoliation syndrome was noted. Occasionally the alpha-and beta-chains of hemoglobin, a contaminant in aqueous humor introduced during sampling, were also detected. We conclude from these studies that mPC-CE-MS is an attractive complimentary technique for proteome research, as this approach enables direct mapping and characterization of low concentrations of proteins that are present in complex physiologically derived fluids.

Apolipoprotein A-I↗
PubMed1997

Cytotoxicity of spin trapping compounds.

Spin trapping compounds are used frequently to detect free radicals released by cells. Their cytotoxicity has to be considered in order to prevent perturbations of normal cell growth and viability. Eleven spin traps (eight nitrones and three nitroso traps) have been tested for their effects on bovine aortic endothelial cells (toxicity range, 50% survival rate). The lowest cytotoxicity was found for 5,5-dimethylpyrroline-1-oxide and 2,2,4-trimethyl-2H-imidazole-1-oxide whereas nitrosobenzene and 2-methyl-2-nitrosopropane exerted the strongest cytotoxic effects. In addition, three nitronyl nitroxides were tested. Their cytotoxicity was found to be dependent on substitution, and the toxic concentration of a lipophilic derivative was found to be more than two orders lower as compared to a hydrophilic derivative. The results of this study indicate that most spin traps can be used in cell cultures at customary (i.e. millimolar) concentrations; caution is recommended when nitroso spin traps are applied to cells.

Animals↗
PubMed1996

Corticotropin-releasing hormone (CRH) receptors in the mesenteric small arteries of rats resemble the (2)-subtype.

The potencies of the corticotropin-releasing hormone (CRH) agonistic peptides oCRH, h/rCRH, frog sauvagine, and carp urotensin I and of the antagonistic peptide alpha-helical CRH9-41 were compared in 3 different in vitro assays: (a) receptor binding to rat brain membranes; (b) release of ACTH/beta-endorphin from rat pituitary cells; and (c) relaxation of rat mesenteric small arteries. From their potency profiles, especially from the high potency of sauvagine relative to CRH in the relaxation assay, it is concluded that the receptors mediating the hypotensive action of systemic CRH in vascular smooth muscle are different from those in the pituitary and brain, and may be identical or very similar to the recently cloned new CRH receptor type 2.

Adrenocorticotropic Hormone↗
PubMed1996

[Sarcoid tumor of the breast].

We report on a 56 years old women with an enlarging breast mass in the region of an old scar due to a former diagnostic excision. Mammography and sonography were without value while MRT was suspicious for breast cancer. In the frozen section of the excised tissue a carcinoma was diagnosed and therefore a mastectomy performed. This diagnosis was in correct, instead a granulomatous process in the breast and the axillary lymph nodes took place. In respect to a pulmonary sarcoidosis and to laboratory results a true breast sarcoidosis may be supposed. It was also discussed whether it could be a lipogranulomatous pseudosarcoidosis.

Biopsy↗
PubMed1995

[Histology and cytology of laparoscopically operated "simple ovarian cysts"].

In a retrospective study the histopathological findings of 127 laparoscopically operated unilocular anechoic smooth-walled ovarian cysts have been correlated with clinical characteristics (age, duration of observation, complaints, hormonal treatment), size by ultrasound, kind and colour of cysts content as well as cytological findings. The age of patients differed from 16-61 years (mean +/- s: 36 +/- 16). The histopathologic findings yielded 15 (11.8%) functional cysts, 30 (23.6%) persistent corpus luteum cysts, 9 (7.1%) endometriomas, 7 (5.5%) cystic teratomas, 9 (7.1%) undifferenciated cysts and 57 (44.9%) cystadenomas. There were no differences between histopathologic diagnosis groups according to age and cysts size by ultrasound. Functional cysts with complaints (n = 6) may explain that the observation time in 60% of all functional cysts was smaller than 6 weeks, whereas persistent corpus luteum cysts, endometriomas, cystic teratoma and cystadenomas had been observed for longer than 6 weeks in more than two thirds. Intraoperative evaluation of cysts content as "chocolate"-like was suspicious of endometriomas, but was also present in cysts of other histopathological findings. By means of cytology, endometrioma (siderophages) was suspected in 44.4% and a cystadenoma in 42.1% of all histopathologically verified cases. In all, the cytologic findings were useful for correct histopathological diagnosis in only 33.9% of all 127 cases. It is concluded that differential diagnosis of simple ovarian cysts is not possible by clinical characteristics, neither by ultrasound nor by cytological evaluation. Ovarian cysts should be observed for at least two hormonal cycles. A hormonal treatment by combination preparations containing high doses of oestrogen is also recommended. In cases of persisting ovarian cysts laparoscopic removal is necessary.

Adolescent↗
PubMed1995

The sera of spontaneously hypertensive rats contain agonistic auto-antibodies against the beta 1-adrenoceptor.

OBJECTIVE: To examine auto-antibodies in the sera of spontaneously hypertensive rats (SHR) and investigate the possibility of abnormalities of the immune system in those rats. DESIGN: Blood samples were taken from 18-month-old SHR and age-matched Wistar-Kyoto (WKY) rats. The immunoglobulin fraction was prepared from the rat sera. METHODS: Immunoglobulins were investigated in a sensitive biological test system using spontaneously beating neonatal rat heart myocytes. RESULTS: Immunoglobulins prepared from the sera of the 18-month-old SHR increased the beating frequency of cultured rat heart myocytes. This positive chronotropic effect induced by the auto-antibody-containing immunoglobulin fraction was realized via the beta 1-adrenergic receptor. CONCLUSIONS: The sera of the investigated ageing SHR contain agonistic auto-antibodies directed against the beta 1-adrenoceptor. These anti-beta-adrenoceptor antibodies in the SHR, like those in the sera of cardiomyopathic patients, recognize in most cases the second extracellular loop of the beta 1-adrenoceptor as the site of the antigenic determinant, and act in a similar way to the antibodies observed in the sera of cardiomyopathic patients. The present findings provide the opportunity of using ageing SHR as a model to investigate the development and possible pathogenic role of the agonistic auto-antibodies that recognize the beta 1-adrenoceptor.

Animals↗
PubMed1995

4-Hydroxynonenal, a novel indicator of lipid peroxidation for reperfusion injury of the myocardium.

4-Hydroxynonenal (HNE) has been proposed as an important marker of radical-induced lipid peroxidation (LPO) during postischemic reperfusion injury of the myocardium. Therefore, the liberation of HNE into the effluent of isolated perfused rat hearts was investigated. For the first time, the formation of the aldehyde is demonstrated in myocardium. During control perfusion, 1.28 +/- 0.33 pmol HNE.min-1.mg protein-1 were formed by the hearts of 18-mo-old Wistar-Kyoto (WKY) rats and 2.74 +/- 1.12 pmol.min-1.mg protein-1 by those of 18-mo-old spontaneously hypertensive (SHR) rats, respectively. In the WKY group, HNE release increased to 3.35 +/- 1.13 pmol.min-1.mg protein-1 2 min after the onset of reperfusion following 30 min of total and global ischemia compared with the preischemic control period (P < 0.05). In the SHR group, HNE liberation was higher during reperfusion (8.66 +/- 1.33 pmol.min-1.mg protein-1, maximum at 2 min reperfusion) compared with both the respective preischemic control and the respective reperfusion interval of the WKY group (P < 0.05 each). The SHR rats showed signs of congestive cardiac failure of a decompensated hypertrophy in comparison to the normotensive WKY rats. Moreover, the SHR rat hearts exhibited a lower release of adenine nucleotide degradation products (adenine, inosine, hypoxanthine plus uric acid: 48.1 +/- 10.2 nmol.30 min-1.mg protein-1; P < 0.05) and a diminished functional recovery (left ventricular developed pressure, 32 +/- 16 mmHg; P < 0.05) during 30 min of reperfusion compared with the WKY group (77.9 +/- 14.4 nmol.30 min-1.mg protein-1; 90 +/- 21 mmHg).(ABSTRACT TRUNCATED AT 250 WORDS)

Aldehydes↗
PubMed1994

Inhibitory effects of sulfonated shale oils (ammonium bituminosulphonates, Ichthyols) on enzymes of polyenoic fatty acid metabolism.

The two commercial pharmaceutical preparations of ammonium bituminosulphonates, Leukichthol and Dark Ichthyol, were shown to inhibit the formation of 5S-hydroxy-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-HETE) from external arachidonic acid by human polymorphonuclear leukocytes stimulated by ionophore A-23187 in a dose-dependent manner. Pure arachidonate 15-lipoxygenases from rabbit reticulocytes and soya beans, and the particulate prostaglandin endoperoxide synthase from sheep vesicular glands, were also inhibited. With the reticulocyte lipoxygenase, the Ichthyols suppressed the enzyme activity by two different mechanisms: (1) a prolongation of the lag period typical of lipoxygenase catalysis, and (2) by a lowering of the maximal enzymatic activity after the end of lag period. As expected, the first effect was reversed by the addition of the lipoxygenase product 13S-hydroperoxy-9Z,11E-octadecadienoic acid (13-HpODE). Ammonium bituminosulphonates are thus universal inhibitors of lipoxygenase activities, and the latter are of potential importance in inflammatory dermatoses.

Arachidonic Acid↗
PubMed1994

[Changes in surgical treatment of cystic teratoma--620 cases].

Among 3492 patients with ovarian tumors subjected to operation between 1/1957 and 3/1994 at the Department of Obstetrics and Gynaecology at the University of Rostock 620 (17.8%) cases of teratomas were found. Histology findings, age, tumor size, bilaterality and malignity of these 620 cases were analyzed. The histologic differentiation yielded 604 (17.3%) mature teratomas (dermoid cysts), 15 monodermale and 1 immature teratoma. Division of total period in the time before and after 1990-since then we have got the possibility of laparoscopic operation-reveals that presumably by increasing use of ultrasound a decrease in mean age at time of diagnosis from 40.2 +/- 20 to 30.7 +/- 12 as well as in tumor size (9 +/- 4 resp. 4 +/- 2 cm) has been achieved. A secondary malignant transformation of epithelial component has been found in 0.5% (3/604) and bilaterality in 11% of the cases. With regard to general rules of laparoscopic operations the intact dermoid cyst enucleation is recommended in premenopausal and extirpation in postmenopausal women. For opening, reduction of volume, and removal of the dermoid cyst from the abdominal cavity, an endo-bag or endo-catch respectively should be used.

Adolescent↗
PubMed1993

Influence of 3-cyano-2-morpholino-5-(päyrid-4-yl)pyridine (AWD 122-14) and dopamine on left ventricular function during acute volume load in 18-month-old spontaneously hypertensive rats and Wistar-Kyoto rats.

Effects of AWD 122-14, a new cardiotonic agent, and dopamine were studied in an experimental model of congestive heart failure in 12- and 18-month-old spontaneously hypertensive rats (SHR rats) in comparison to normotensive Wistar-Kyoto rats (WKY rats) as control group. This model combines an acute volume overloading with an already existing chronic pressure overload. Heart rate (HR), peak left ventricular pressure (PLVP), left ventricular enddiastolic pressure (LVEDP), and left ventricular contractility index (LV dp/dtmax) were significantly elevated in SHR rats versus WKY rats. Left ventricular mass (LVM) to body mass (bw) ratio was increased in SHR rats and there was a parallel, rightward shift of the left ventricular diastolic pressure-volume-relationship in the 18-month-old SHR rats. Thus for a given LVEDP, there is an increased left ventricular enddiastolic volume (LVEDV) in SHR rats, indicating a true structural outgrowth of the left ventricular lumen. During acute volume overloading LVEDP increased in the 12- and 18-month-old WKY rats and in the 12-month-old SHR rats. In contrast, the 18-month-old SHR rats showed no increase of the already very high baseline level of LVEDP. Dopamine and AWD 122-14 increased LV dp/dtmax in all groups. AWD 122-14 was able to reduce left ventricular filling pressure of the 18-month-old SHR rats. A further interesting finding was that AWD 122-14 reduced the content of thiobarbituric acid material in the left ventricle in the 18-month-old SHR rats (reduced lipid peroxidation), suggesting a possible cardioprotective action of this substance.

Animals↗
PubMed1993

Hemodynamic response and effects on myocardial energetics of 3-cyano-2-morpholino-5-(pyrid-4-yl)pyridine (AWD 122-14) in anesthetized minipigs.

AWD 122-14, a new positive inotropic and vasodilating agent, was investigated in comparison to amrinone, milrinone and dopamine in anesthetized minipigs. AWD 122-14 (1.17.10(-7)-37.5.10(-7) mol/kg) increased dose-dependent left ventricular contractility (LV dp/dtmax) (122x5 +/- 11x3%; ED50 = 8.1x10(-7) to mol/kg). Dopamine (2.64x10(-8)-21x12 x 10(-8) mol/kg) in comparison increased contractility up to 153.1 +/- 44.9% of control value and is about 20 times more potent than AWD 122-14 at the ED50 value and about 10 times more potent at the ED30 value. Amrinone (1.60x10(-6)-16.90x10(-6) mol/kg) and milrinone (1.48x10(-7)-23.70x10(-7) mol/kg) only slightly increased contractility in anesthetized minipigs, but they appear to posses a similar pharmacological profile like AWD 122-14. The hemodynamic effects were associated with an increase in myocardial oxygen consumption (E1: 18.8 +/- 10.0%) due to the marked increases in LV dp/dtmax and heart rate. LVMW was unchanged and LVSW decreased (-29.0 +/- 10.2%) after application of AWD 122-14. The reduction in left ventricular work (LVMW, LVSW) and the increase in myocardial oxygen consumption led to a decrease of left ventricular external mechanical efficiency of the non-failing minipig heart (Etam: -21.1 +/- 9.4%). Additional hemodynamic effects of AWD 122-14 were studied under calcium channel blockade (verapamil, nifedipine). After pretreatment with verapamil the agent (1.17.10(-7)-18.75.10(-7) mol/kg i.v.) increased left ventricular contractility between 42.9 +/- 41.6% and 58.5 +/- 33.3%. After pretreatment with nifedipine the agent induced a dose-dependent increase in LV dp/dtmax between 11.1 +/- 7.7% and 47.8 +/- 23.7%.(ABSTRACT TRUNCATED AT 250 WORDS)

Amrinone↗
PubMed1993

[Granular cell tumor of the breast].

Report about a 46 year old women with granular cell tumor of the breast. Clinical features, mammography and sonography has appearances highly suspicious for breast cancer. Tumorectomy and axillary lymphonodectomy were performed. Estrogen and progesterone receptor both were histochemically and biochemically negative. Estradiol and prolactin levels in serum were normal. Cathepsin D in cytosol was slightly elevated, DNA-flow-cytometry revealed no signs of malignancy. Evident was the high content of protein S100 in cytosol of tumor cells.

Adipose Tissue↗