Concentration of Zearalenone,Alpha-Zearalenol and Beta-Zearalenol in the Myocardium and the Results of Isometric Analyses of the Coronary Artery in Prepubertal Gilts

The carry-over of zearalenone (ZEN) to the myocardium and its effects on coronary vascular reactivity in vivo have not been addressed in the literature to date. Therefore, the objective of this study was to verify the hypothesis that low ZEN doses (MABEL, NOAEL and LOAEL) administered per os to prepubertal gilts for 21 days affect the accumulation of ZEN, α-ZEL and β-ZEL in the myocardium and the reactivity of the porcine coronary arteries to vasoconstrictors: acetylcholine, potassium chloride and vasodilator sodium nitroprusside. The contractile response to acetylcholine in the presence of a cyclooxygenase (COX) inhibitor, indomethacin and / or an endothelial nitric oxide synthase (e-NOS) inhibitor, L-NAME was also studied. The results of this study indicate that the carry-over of ZEN and its metabolites to the myocardium is a highly individualized process that occurs even at very low mycotoxin concentrations. The concentrations of the accumulated ZEN metabolites are inversely proportional to each other due to biotransformation processes. The levels of vasoconstrictors, acetylcholine and potassium chloride, were examined in the left anterior descending branch of the porcine coronary artery after oral administration of ZEN. The LOAEL dose clearly decreased vasoconstriction in response to both potassium chloride and acetylcholine (P < 0.05 for all values) and increased vasodilation in the presence of sodium nitroprusside (P = 0.021). The NOAEL dose significantly increased vasoconstriction caused by acetylcholine (P < 0.04), whereas the MABEL dose did not cause significant changes in the vascular response. Unlike higher doses of ZEN, 5 μg/kg had no negative influence on the vascular system.     

Immunohistochemical examination of an orbital alveolar soft part sarcoma

· Background: A 32 year-old male patient had a 6-week history of left-sided proptosis. Computer tomography revealed a 16×15×15 mm smooth and well-defined mass between the optic nerve and the medial and superior rectus muscles in the left orbit. · Methods: The tumour was excised via a cranio-medial orbitotomy approach. · Results: Histopathological examination, immunohistochemistry and electron microscopy findings were consistent with an alveolar soft part sarcoma. Immunohistochemical staining showed positive immunoreactivity for neurone-specific enolase, vimentin, p53 (30%), p21 (10%) and cyclin D1 (20%), and negative immunoreactivity for CD45, cytokeratins, S-100 protein, glial fibrillary acidic protein, synaptophysin, chromogranin, calcitonin, serotonin, thyreoglobulin, desmin, myosin, actin, HMB-45, pRB, p16 and BCL-2. The growth fraction of the tumour cells was 3%. At examination 4 years after surgical excision, there was no evidence of local recurrence or for metastases. · Conclusion: Alveolar soft part sarcoma of the orbit is a rare malignant tumour best controlled by surgery. The unpredictable behaviour of these neoplasms, however, indicates the need for long-term follow-up. Received: 2 July 1998 Revised version received: 31 August 1998 Accepted 3 September 1998     

Vitamin D bioavailability and catabolism in pediatric chronic kidney disease

Background

Vitamin D-binding protein (DBP) and catabolism have not been examined in the clinical setting of childhood chronic kidney disease (CKD).

Methods

The concentrations of serum vitamin D {25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)₂D], 24,25-dihydroxyvitamin D [24,25(OH)₂D]}, DBP, intact parathyroid hormone (iPTH), and fibroblast growth factor-23 (FGF23) were measured in 148 participants with CKD stages 2–5D secondary to congenital anomalies of the kidney/urinary tract (CAKUT), glomerulonephritis (GN), or focal segmental glomerulosclerosis (FSGS). Free and bioavailable 25(OH)D concentrations were calculated using total 25(OH)D, albumin, and DBP concentrations.

Results

The concentrations of all vitamin D metabolites were lower with more advanced CKD (p?<?0.001) and glomerular diagnoses (p?≤?0.002). Among non-dialysis participants, DBP was lower in FSGS versus other diagnoses (FSGS–dialysis interaction p?=?0.02). Winter season, older age, FSGS and GN, and higher FGF23 concentrations were independently associated with lower concentrations of free and bioavailable 25(OH)D. Black race was associated with lower total 25(OH)D and DBP, but not free or bioavailable 25(OH)D. 24,25(OH)₂D was the vitamin D metabolite most strongly associated with iPTH. Lower 25(OH)D and higher iPTH concentrations, black race, and greater CKD severity were independently associated with lower levels of 24,25(OH)₂D, while higher FGF23 concentrations and GN were associated with higher levels of 24,25(OH)₂D.

Conclusions

Children with CKD exhibit altered catabolism and concentrations of DBP and free and bioavailable 25(OH)D, and there is an important impact of their underlying disease.     

Abdominal Burkitt lymphoma mimicking the ovarian cancer. Case report and review of the literature

Primary Burkitt lymphoma is a lymphoblastic B-cell malignant tumor with very aggressive course. Its abdominal form involving internal genital organs is very rare. CASE: We report the case of 27-year-old woman treated for abdominal Burkitt lymphoma. The patient presented bilateral ovarian tumors with ascites, pain and elevated CA 125 over 900 IU/ml. During laparotomy an advanced neoplasmatic disease involving internal genital organs has been diagnosed. Bilateral salphingo-oophorectomy and omentectomy have been performed. Additionally, the neoplasmatic tumor from ileo-coecal region has been ressected in order to prevent ileus. Pathologic examination has revealed an abdominal Burkitt lymphoma. After surgery, polychemotherapy has been administered (COP followed by CODOX-M+IVAC). The patient, 36 months after surgical treatment, remains under the control of our Department. No signs of recurrence have been detected so far. CONCLUSIONS: The presence of primary abdominal Burkitt lymphoma may include clinical and laboratory findings suggesting the presence of ovarian cancer. Chemotherapy appears to be an essential therapeutic management for all forms of Burkitt lymphoma. Clinically advanced Burkitt lymphoma may be successfully managed with chemotherapy.     

PAC1 receptors in chick cerebral cortex: characterization by binding of pituitary adenylate cyclase-activating polypeptide, [125I]-PACAP27

In this study we characterized receptors for pituitary adenylate cyclase-activating polypeptide (PACAP) in chick cerebral cortex by in vitro binding technique, using [125I]-PACAP27 as a ligand. The specific binding of [125I]-PACAP27 to chick cerebral cortical membranes was found to be rapid, stable, saturable, and of high affinity. Scatchard analysis suggested binding to a single class of receptor binding sites with high affinity (K(d)=0.41+/-0.08 nM) and high capacity (B(max)=457+/-35 fmol/mg protein). The relative rank order of potency of the tested peptides to inhibit [125I]-PACAP27 binding to chick cerebrum was: PACAP38 approximately PACAP27>PACAP6-27 approximately PACAP6-38 > chicken VIP > mammalian VIP > secretin (inactive). It is concluded that the cerebral cortex of chick, in addition to VPAC recognition sites, contains a large population of PAC(1)-type receptor binding sites.     

Magnetic sensor for arterial distension and blood pressure monitoring

A novel sensor for measuring arterial distension, pulse and pressure waveform is developed and evaluated. The system consists of a magnetic sensor which is applied and fixed to arterial vessels without any blood vessel constriction, hence avoiding stenosis. The measurement principle could be validated by in vitro experiments on silicone tubes, and by in vivo experiments in an animal model, thereby indicating the non-linear viscoelastic characteristics of real blood vessels. The sensor is capable to provide absolute measurements of the dynamically varying arterial diameter. By calibrating the sensor, a long-term monitoring system for continuously measuring blood pressure and other cardiovascular parameters could be developed based on the method described. This will improve diagnostics for high risk patients and enable a better, specific treatment.     

Alcohol dehydrogenase isoenzymes and aldehyde dehydrogenase activity in the sera of patients with esophageal cancer

Various alcohol dehydrogenase (ADH) isoenzymes and aldehyde dehydrogenase (ALDH) exist in the human esophageal mucosa. In our last experiments we have shown that ADH and ALDH are present also in the esophageal cancer cells. Moreover, the activities of total ADH and class IV isoenzymes were significantly higher in cancer tissue than in healthy mucosa, which suggests that these changes may be reflected by enzyme activity in the serum. Therefore, we measured the activity of total alcohol dehydrogenase, and classes I–IV of this enzyme and aldehyde dehydrogenase in the sera of patients with this cancer. Serum samples were taken for routine biochemical investigation from 67 patients with esophageal cancer before treatment. Total ADH activity was measured by photometric method with p-nitrosodimethylaniline (NDMA) as a substrate and ALDH activity by the fluorometric method with 6-methoxy-2-naphtaldehyde as a substrate. For the measurement of the activity of class I and II isoenzymes, we employed the fluorometric methods, with class-specific fluorogenic substrates. The activity of class III alcohol dehydrogenase was measured by the photometric method with formaldehyde and class IV with m-nitrobenzaldehyde as a substrate. A statistically significant increase of class IV alcohol dehydrogenase isoenzymes was found in the sera of cancer patients. The median activity of this class isoenzyme in the total cancer group increased by about 26.5% (7.42 mU/l) in comparison to the control level (5.46 mU/l). The total alcohol dehydrogenase activity was significantly higher (30%) among patients with cancer. The activities of other tested ADH isoenzymes and total ALDH were unchanged. The activity of the class I ADH isoenzyme was significantly higher in the sera of drinkers with esophageal cancer than non-drinking patients. The increased total activity of alcohol dehydrogenase and class IV isoenzyme in the sera of patients with esophageal cancer probably can be caused by release of this isoenzyme from cancer cells or might be stimulated by alcohol drinking.