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Biomedical subjects

A Vychytil

Publications and source records attributed to A Vychytil.

25 records · Page 2Linked to original sources

Pattern of endothelin immunostaining during rejection episodes after kidney transplantation.

A pathophysiological role for endothelin (ET), one of the most potent vasoconstrictor peptides, has been suggested in ATN and during kidney allograft rejection. As ET is known to have predominantly local effects, we investigated intrarenal ET content in 82 kidney transplant biopsies and 10 normal control kidneys. ET-immunostaining, using a polyclonal anti-ET-1 antibody was investigated in 4 intrarenal vascular beds (glomeruli, capillaries, arterioles, arteries) and in tubular epithelium. Normal kidneys showed a strong staining of endothelial cells in all vessels and of tubular epithelium. In biopsies with signs for acute vascular rejection a marked decrease in ET staining intensity was seen. In contrast, normal staining similar to control kidneys was detected in interstitial rejection and in ATN. The presence of chronic CyA toxicity, however, lead to a significant reduction of endothelial ET staining. Neither mean doses nor trough levels of CyA correlated closely with the immunostaining findings. Plasma big-ET levels were elevated during vascular rejection, but not in interstitial rejection and ATN. This study demonstrates a significant reduction of ET immunostaining in intrarenal vascular endothelium of kidney transplant biopsies showing signs of endothelial damage. In vascular allograft rejection these changes are often associated with a concomitant rise in plasma ET levels. Our findings support a postulated role of ET in vascular rejection and during CyA toxicity and show that endothelial damage, independent of its genesis, can lead to a reduction of intrarenal ET content.

Adult↗

Emergency intubation with the Combitube in a grossly obese patient with bull neck.

A grossly obese patient with bull neck required immediate intubation. Endotracheal intubation failed because visualization of the vocal cords was not possible. As an alternative, the Combitube was inserted without difficulty and the patients lungs were ventilated via the Combitube until tracheotomy was performed on the following day. The patient survived and was discharged alive from the hospital 5 weeks later. The Combitube has gained worldwide interest and is now included in the Guidelines of the American Heart Association and the American Society of Anesthesiologists.

Aged↗

Cytokine release and dynamics of leukocyte populations after CD3/TCR monoclonal antibody treatment.

Cytokine release and clinical side effects resulting from the use of OKT3 and BMA 031 monoclonal antibodies in the treatment of kidney graft recipients were evaluated and compared. The rise observed in serum levels of interferon gamma. TNF alpha, and IL-8 was similar after administration of either monoclonal antibody. Furthermore, both OKT3 and BMA 031 resulted in rapid disappearance not only of virtually all T cells, but also of substantial percentages of all major leukocyte populations from the circulation; this effect is probably due to cytokine release activating endothelial cells and thereby causing extravasation even of leukocytes not specifically recognized by the administered antibodies. Evidence has thus been obtained that BMA 031 is as potent as OKT3 in inducing unequivocal signs of T cell activation in vivo. However, while OKT3 therapy was accompanied by adverse side effects in our study as in previous ones, we saw no such reactions in any of the patients receiving BMA 031. This contrast might be due to different mechanisms of leukocyte activation possibly inducing other mediators in the case of OKT3, which then, in combination with the cytokines, could generate treatment-associated morbidity.

Antibodies, Monoclonal↗

Bone metabolism in patients with functioning kidney grafts: increased serum levels of osteocalcin and parathyroid hormone despite normalisation of kidney function.

In order to study bone metabolism after renal transplantation we measured serum levels of parathyroid hormone (PTH) and osteocalcin (OC), a specific biochemical parameter of bone formation, in 30 patients with functioning kidney grafts and 30 sex- and age matched control subjects. Serum levels of OC and PTH were markedly elevated in the kidney transplantation patients when compared with the control subjects (p less than 0.0001). Elevated levels of OC and PTH were present even in patients with very well functioning transplants. In the kidney transplantation patients, a significant positive correlation between serum OC and serum PTH levels could be found. Our data give evidence of persistent hyperparathyroidism and increased bone turnover in patients after renal transplantation.

Adult↗

Is absorption of high-dose oral iron sufficient in peritoneal dialysis patients?

OBJECTIVE: Iron supplementation plays a major role in erythropoietin-treated end-stage renal disease patients. For peritoneal dialysis (PD) patients, oral iron substitution is more convenient than intravenous therapy. However, disturbed iron absorption and adverse effects may be limiting factors for oral treatment. Nevertheless, we compared the response to a high-dose and low-dose oral iron absorption test between PD patients and healthy control subjects. PATIENTS AND INTERVENTIONS: In 34 PD patients and 15 healthy control subjects, blood samples were taken at baseline as well as 2, 4, and 8 hours after oral intake of 4 tablets iron sulfate (105 mg elemental iron per tablet). In a subgroup of 6 PD patients and 6 control subjects, the oral iron absorption test was repeated using 1 tablet iron sulfate. RESULTS: There was no significant difference in the increase in serum iron during the test between the two groups. As known for healthy subjects, iron absorption was significantly better in PD patients with absolute iron deficiency compared to those with functional iron deficiency. Iron-repleted PD patients showed the lowest iron absorption, indicating that a high dose of oral iron did not overwhelm the ability of the bowel tract to reject unneeded iron. Increasing the oral iron dose from 1 to 4 tablets was followed by a better response in a small subgroup of PD patients compared to control subjects. Side effects such as nausea and vomiting occurred more frequently during high-dose oral iron in control subjects than in PD patients (20% vs 8.8%). CONCLUSION: High-dose oral iron is well absorbed in iron-depleted PD patients. This kind of oral iron therapy should be considered in some subgroups of PD patients with iron deficiency, particularly in those patients with poor vascularization of arm veins or intolerance to intravenous iron preparations.

Absorption↗