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R Hetzel

Publications and source records attributed to R Hetzel.

8 recordsLinked to original sources
PubMed1998

Renal transplantation in secondary systemic amyloidosis.

When renal amyloidosis has progressed to end-stage renal failure, most patients are severely affected by systemic amyloidosis and nephropathy. An alternative to chronic dialysis is renal transplantation. We present a patient with amyloid nephropathy who developed recurrent transplant amyloidosis. Renal transplantation was performed in 1985 with a living related donor. In 1990 the patient developed amyloidosis of the graft with membranous nephropathy and tubular acidosis due to hyporeninemic hypoaldosteronism. Secondary amyloidosis has been reported to involve glandular organs inducing hypothyroidism, hypocortisolism and hypoaldosteronism. Cyclosporine has been reported to induce hyporeninemic hypoaldosteronism and tubular acidosis, but not hypocortisolism and hypothyroidism. Progression of the amyloidosis of the graft was confirmed by a renal biopsy in 1993. Data published in the literature indicate that the survival rate of amyloidotic graft recipients is worse than those of non-amyloidotic graft recipients. This was confirmed in an analysis of the current CTS data which showed an impaired survival rate at 5-yr of 66 +/- 4% (+/- SE) for patients with amyloidosis (n = 413) as compared with 86 +/- 1% (p < 0.0001) for patients with glomerulonephritis and 84 +/- 1 (p < 0.01) for patients with polycystic kidney disease. Graft survival after 5 years was 55 +/- 4% in patients with amyloidosis as compared with 63 +/- 1% (p = 0.02) in patients with glomerulonephritis and 68 +/- 1% in patients with polycystic kidney disease. Graft survival was improved in amyloidotic patients treated with cylosporine as compared with patients on steroids and azathioprine (55 +/- 4% vs. 38 +/- 8%, p < 0.05). It is concluded that renal transplantation is the renal replacement therapy of choice for patients with AA-type amyloidosis although the overall patient survival is impaired in comparison with patients with other diseases.

Adult↗
PubMed1976

Dynamics of the aromatic amino acid residues in the globular conformation of the basic pancreatic trypsin inhibitor (BPTI). II. Semi-empirical energy calculations.

The molecular conformation of the basic pancreatic trypsin inhibitor (BPTI) is known in considerable detail from both X-ray studies in single crystals and NMR studies in solution. The NMR experiments showed that the aromatic rings of the phenylalanyl and tyrosyl residues can undergo rapid rotational motions about the C beta--Cv bond. The present paper describes a model investigation of the mechanistic aspects of these intramolecular rotational motions. From calculations of the conformational energies for molecular species derived from the X-ray structure by rotations of individual aromatic rings, it was apparent that the rotational motions of the aromatics could only be understood in a flexible structure. Flexibility was simulated by allowing the protein to relax to an energetically favorable conformation for each of the different rotation states of the aromatic rings. It was then of particular interest to investigate how the perturbations caused by different rotation states of the aromatic rings were propagated in the protein structure. It was found that the rotation axes C beta--Cv were only slightly affected (delta X1 approximately less than 20 degrees. The most sizeable perturbations are caused by through space interactions with nearby atoms, which move away from the ring center and thus release the steric hindrance opposing the rotational motions. The values for the energy barriers obtained from the energy minimization are of the same order of magnitude as those measured by NMR.

Amino Acids↗