Divergent regulation of vascular endothelial growth factor and of erythropoietin gene expression in vivo

There is accumulating evidence from in vitro experiments that the gene expression of the vascular endothelial growth factor (VEGF) is, like that of the erythropoietin (EPO) gene, regulated by the oxygen tension and by divalent cations such as cobalt. Since the information about the regulation of VEGF gene expression in vivo is rather scarce, this study aimed to examine the influence of hypoxia and of cobalt on VEGF gene expression in different rat organs and to compare it with that on EPO gene expression. To this end male Sprague-Dawley rats were exposed to carbon monoxide (0.1% CO), hypoxia (8% O₂ ) or to cobalt chloride (12 and 60 mg/kg s.c.) for 6 h. mRNA levels for VEGF- 188, -164, and -120 amino acid isoforms in lungs, hearts, kidneys and livers were semiquantitated by RNase protection. For these organs we found a rank order of VEGF mRNA abundance of lung >> heart > kidney = liver. EPO mRNA levels were semiquantitated in kidneys and livers. Hypoxia, CO and cobalt increased EPO mRNA levels 60-fold, 140-fold and 5-fold, respectively, in the kidneys, and 11-fold, 11-fold and 3-fold, respectively, in the livers. None of these manoeuvres caused significant changes of VEGF mRNA in lung, heart or kidneys. Only in the livers did hypoxia lead to a significant (50%) increase of VEGF mRNA. These findings suggest that, in contrast to the in vitro situation, the expression of the VEGF gene in normal rat tissues is rather insensitive to hypoxia. In consequence, the in vivo regulation of the VEGF and the EPO genes appear to differ substantially, suggesting that the regulation of the VEGF and EPO genes may not follow the same essential mechanisms in vivo. Received: 31 July 1995/Received after revision: 20 November 1995/Accepted: 27 November 1995     

Change of surgical treatment in benign thyroid gland diseases-- influence of surgical management on perioperative complications

Since the beginning of 1994 standardized primary radical resection was performed in benign thyroid diseases at the surgical department, Barmherzige Brueder Hospital, Graz. In multinodular euthyroid goiter bilateral lobectomy or near total lobectomy respectively was done. In case of Graves' disease unilateral lobectomy and contralateral near total resection or "en bloc" thyroidectomy was performed. In accordance with literature a significant reduction of recurrent laryngeal nerve paralysis from approximately 9% to 1.2% occurred in our patients if this surgical procedure was performed consequently. Hypocalcemia rate after surgery needing treatment was approximately 1% at the time of demission.     

Fibrous histiocytoma: a histological and statistical analysis of 155 cases.

Various salient histological features were rated from + to +++ in a semiquantitative evaluation of a series of 155 cases of fibrous histiocytoma. Relations between individual histological features, as well as between histological findings, localisation and size of lesions, and age or sex of the patient were tested statistically. Most impressive was an inverse proportional relationship between cellular and fibrillar densities: highly cellular fibrous histiocytomas chiefly showed little fiber formation. Accordingly, cases with marked fiber formation were distinguished by low cellularity. Based on this statistically significant relation, 3 subtypes could be classified on a scale of increasing fiber formation and decreasing cellular density. The majority of cases showed medium cellularity and fibrillar density, with distinct storiform (spokewheel or "whirlygig") pattern which is compatible with typical storiform histocytoma, including clincally progressive, recurrant FH and/or "dermatofibrosarcoma protuberans". The typical patient was more frequently female than male, 40 years of age with a 0.5 to 1.0 cm size tumor node in the lower extremities located in the corium, often with beginning infiltration of the subcutaneous fat tissue.     

Malignant tumor of humerus with features of "adamantinoma" and Ewing's sarcoma

This female patient was born in 1935 and died in 1976 with a malignant bone tumor involving the proximal humerus following multiple local recurrences, axillary lymph node metastases, and pulmonary metastases. Histologically, over the course of time, there was an increase in features of an atypical Ewing's sarcoma, at the expense of findings of a typical, extra-cranial so-called adamantinoma. In contrast to another report, our case showed neither epithelial nor endothelial features on fine structural examination, but rather primitive mesenchymal cells, as is described for Ewing's sarcomas.     

Tissue array technology for testing interlaboratory and interobserver reproducibility of immunohistochemical estrogen receptor analysis in a large multicenter trial

Semiquantitative immunohistochemical assessment of estrogen receptor (ER) is used to predict the likelihood of response to antiestrogen therapy in breast carcinoma. If semiquantitative immunohistochemical analysis leads to therapeutic decisions, the importance of standardization and quality control increases. ER assessment reproducibility was studied among 172 laboratories using tissue microarray slides with 20 tissue spots negative and 10 tissue spots expressing ER at low, medium, or high levels. More than 80% of the laboratories demonstrated ER positivity in the medium- and high-expressing tissue spots, but only about 43% succeeded with tissue spots with low expression. Poor interlaboratory agreement was based on insufficient retrieval efficacy as shown by additional tests using autoclave pretreatment. The immunohistochemical scores used to quantify therapeutic target molecules remain inconclusive as long as progress toward standardized immunohistochemical procedures and evaluation is not achieved. Tissue microarray technology has proved its suitability for large-scale immunohistochemical trials, giving rise to new dimensions in control assessment.     

Assessment of the antigenic response in humans to a recombinant mutant interferon beta

Cancer patients were given a recombinant mutant interferon by alternating IM and IV injections with weekly escalation of doses from 0.1 to 400 million U. Antibodies specific to the interferon of the IgG class were detected in 24 of 30 patients using an indirect enzyme-linked immunosorbent assay. Serum from only 1 of the 30 patients had detectable ability to neutralize interferon biological activity. Thein vivo interferon serum level, assayed as antiviral activity immediately after IV injection, was not lower than levels seen in the absence of antibodies. Antibodies did not alter the kinetics of clearance of interferon from the serum after IV administration. Antibody levels progressively decreased when interferon administration was discontinued. In most patients antibody levels decreased during a maintenance period when interferon was being administered only by the IV route. In a subsequent trial interferon was given IV, and antibody developed in only 2 of 36 patients. In contrast, in a trial in which interferon was given IM, 20 of 25 patients developed antibody. No antibody-related clinical sequelae could be detected in any of these patients.     

Troponin C regulates the rate constant for the dissociation of force-generating myosin cross-bridges in cardiac muscle

It is well known that cardiac troponin C (cTnC) regulates the association of force-generating myosin cross-bridges. We report here evidence for an additional role for cTnC. This hypothesis states that Car²⁺ binds more strongly to cTnC when force-generating myosin cross-bridges are attached to actin and that removal of this bound Ca²⁺ accelerates the dissociation of force-generating myosin cross-bridges. Intact Fura-2-loaded rat papillary muscles and skinned (permeabilized) ventricular preparations were used. The preparations were mounted in the Guth Muscle Research System which is capable of measuring simultaneously fluorescence and force in response to length perturbations. All mechanical perturbations of muscle length (isotonic shortening, quick stretches and releases, and length vibrations) which cause dissociation of force-generating myosin cross-bridges during a twitch resulted in Ca²⁺ being released from troponin as judged from changes in the Ca²⁺ transients (Fura-2 (340/380) fluorescence ratio). Thus dissociation of force-generating myosin cross-bridges cause Ca²⁺ to be released from cTnC. Conversely, it would be expected that removal of strongly bound Ca²⁺ from cTnC would result in an increase in the rate of dissociation of force-generating myosin cross-bridges. To test this hypothesis actomyosin ATPase (NADH fluorescence change) and isometric force were measured in skinned cardiac preparations. The ratio of the ATPase/Force is proportional to the rate constant (g_app) for the dissociation of force-generating myosin cross-bridges. The data showed that decreasing the amount of Ca²⁺ bound to cTnC in skinned cardiac fibers caused an increase in the ratio of ATPase/Force, the rate of dissociation (g_app) of force-generating myosin cross-bridges.