Search PubMed⌕ Search

Biomedical subjects

R P Linke

Publications and source records attributed to R P Linke.

At least 91 records · Page 5Linked to original sources
PubMed1990

[Cutaneous amyloidoses].

Significant advances in basic research in biochemistry and immunology has tremendously increased our understanding of amyloidoses. The chemical structure of several amyloid proteins has been partly characterized. Specific antibodies may provide new methods for immunohistological diagnosis of amyloidoses. Cutaneous manifestations can affect the skin only or develop during the course of systemic amyloidoses. Although these conditions are so rare, dermatologists should be aware of the changing clinical manifestations of cutaneous amyloidoses if they wish to avoid diagnostic failures.

Amyloid↗
PubMed1989

Evidence for membrane-bound oligomerization of bacteriophage phi X174 lysis protein-E.

The expression of cloned bacteriophage phi X174 lysis gene E was analyzed in minicells of Escherichia coli using two-dimensional gel electrophoresis. Beside the 10-11-kDa protein-E, at least two additional protein bands were detected, associated with the inner membrane, which showed the same isoelectric point as E. To clarify whether these proteins were E-specific, two different antibodies directed against a beta-galactosidase-E' hybrid protein and a synthetic oligopeptide corresponding to the C-terminal end of protein-E were raised. Immunoadsorption studies with anti-peptide-specific antibodies resulted in the detection of protein-E as well as in the detection of proteins of higher molecular weight. Two of these protein bands were positively recognized by anti beta-galactosidase-E' antibodies. The latter protein bands had the same molecular weight as the putative protein-E bands detected by two-dimensional gel electrophoresis indicating that these bands represent protein-E-specific oligomers. These data support the idea that an E-specific oligomeric structure penetrating the inner and outer membrane of E. coli is formed during the lytic action of protein-E.

Antibodies↗
PubMed1989

Immunoglobulin lambda-light-chain-derived amyloidosis (A lambda) in two horses.

Tumorous amyloid deposits in the nasal mucosa of two horses differed from generalized AA-amyloidosis with respect to clinical features, organ distribution, and resistance to KMnO4 treatment. Using a panel of antibodies directed against different human amyloid fibril proteins and employing the peroxidase-anti-peroxidase (PAP) technique, we showed the described equine amyloid to be A lambda-type, as demonstrated by immunohistochemical cross-reactivity. Consequently, we identified a second amyloid class in horses and showed that immunoglobulin light-chain-derived amyloid may also be present in animals.

Amyloid↗
PubMed1989

Renal transplantation in amyloid nephropathy.

Renal transplantation was performed in 2 patients with end-stage renal disease due to AA-type amyloidosis. One patient with amyloidosis of rheumatoid arthritis (RA) origin died twelve months after renal transplantation in cardiogenic shock. AA-amyloid deposits were demonstrated in the graft even though there were excellent function and no proteinuria. The second patient with amyloid nephropathy due to familial Mediterranean fever (FMF) showed no impairment of graft function 24 months after transplantation. These 2 cases are compared to an additional 31 cases of renal transplantation for amyloid nephropathy described in the literature. Proteinuria was reported in 32.3% and amyloid was detected in the functioning graft in 41.4%. The function was excellent even when small amyloid deposits were present in the graft. Renal transplantation is indicated in cases of amyloid nephropathy of the AA-type, provided life threatening amyloid involvement of other organs is not present.

Adult↗
PubMed1989

Immunohistochemical characterization of spontaneous amyloidosis in captive birds as AA-type, using monoclonal and polyclonal anti-AA antibodies against mammalian amyloid.

Spontaneous amyloid diagnosed by means of Congo red and polarization microscopy in 3 flamingos, 1 crowned crane, 1 red-breasted goose, and 1 common golden-eye was studied using immunohistochemical techniques. The avian amyloid cross-reacted with a number of monoclonal and polyclonal anti-AA antibodies directed against mammalian amyloid fibril proteins. This confirmed that both "secondary" and "idiopathic" avian amyloid is of the AA-type. The results demonstrate the possibility to successfully using cross-reactive anti-AA antibodies for the diagnosis of non-mammalian amyloidosis.

Amyloidosis↗
PubMed1989

Lysine-specific cleavage of beta 2-microglobulin in amyloid deposits associated with hemodialysis.

Amyloid fibrils isolated from bone and carpal synovia of seven patients on long-term hemodialysis were further characterized biochemically. In addition, renal amyloid stones of three dialyzed patients were examined. All deposits and stones were of beta 2-microglobulin-origin (AB-amyloid) by immunohistochemical and immunochemical evaluation. Amyloid fibril extracts were dissolved in 80% formic acid and separated by high performance liquid chromatography in 60% formic acid and 20% 2-propanol. Three major retarded fractions with molecular weights of approximately 24, 12 and 7 to 10 kD were recovered. N-terminal amino acid sequence analysis documented beta 2-microglobulin (beta 2m) as the principal polypeptide in all investigated cases. In addition to proteins with intact N-termini, one fragment commencing with isoleucine in position 7 was found in osseous or synovial amyloid. In renal amyloid stones, one additional fragment was found beginning with serine in position 20. Generally, these data point to proteolytic cleavage carboxyterminal to a lysine residue and establish that not only intact beta 2m but also at least one beta 2m fragment is present in beta 2m-derived amyloid deposits of patients with long-term hemodialysis. The fragmentation pattern is consistent with the action of lysine-specific protease(s) and underscores a potentially important role of limited proteolysis in the pathogenesis of AB-amyloid deposits.

Adult↗
PubMed1989

Amyloid goiter and arthritides after kidney transplantation in a patient with systemic amyloidosis and Muckle-Wells syndrome.

A case of hereditary AA amyloidosis with Muckle-Wells syndrome is described. After a successful kidney transplantation for chronic renal failure due to renal amyloid deposits at age 21, the patient, a white female now 26 years of age, developed a large amyloid goiter as a manifestation of the systemic amyloidosis and recurrent monarthritides. Both observations are novel for this disease. Subtotal thyroidectomy and oral colchicine administration, known to be effective in preventing complications of familial Mediterranean fever, another hereditary type of AA amyloidosis, proved highly effective in the management of this unusual case.

Adult↗
PubMed1989

Subcutaneous amyloid-tumor of beta-2-microglobulin origin in a long-term hemodialysis patient.

beta 2-Microglobulin (beta 2M)-derived amyloidosis has become a major concern in long-term hemodialysis patients. Clinical symptomatology is largely restricted to the articular and periarticular sites and in rare cases systemic manifestations have been described. We present a long-term hemodialysis patient, who after 16 years of hemodialysis with regenerated cellulosic membranes not only had a bilateral carpal tunnel syndrome, cystic bone translucencies and humeroscapular periarthritis but also developed two subcutaneous tumors in both gluteal regions, causing discomfort when sitting. Histology, immunohistology and electron microscopy of the tumor from the right side showed that it consisted of beta 2M-derived amyloid with concurrent scattered amyloid infiltration of the overlying skin. This report therefore adds a new clinical manifestation to the symptomatology of this type of amyloid.

Amyloidosis↗
PubMed1989

Immunoelectron microscopic classification of amyloid in renal biopsies.

Recent classification of amyloidosis is based on the chemical type of amyloid protein involved. In this study, routinely embedded kidney biopsies from nine patients with generalized amyloidosis and renal involvement were tested by immunoelectron microscopy, using the protein A-gold technique, with a panel of antibodies against the following amyloid proteins: AA, A lambda, A kappa and AF. Among the antibodies, the anti-AA was monoclonal (mc1) and the others polyclonal. In all nine cases, only one type of antibody reacted with each amyloid type. Six cases were classified as AA and three cases as A lambda type. These classifications were in agreement with the clinical data and the results of serum and urine immunoelectrophoresis. The gold particles were always associated with amyloid fibrils. No reaction was evident when an amyloid type was stained by a non-corresponding antibody, or in the four control cases without amyloid. The results show that antigenic classification of amyloid is feasible on routinely processed ultra-thin epoxy sections by immunoelectron microscopy, and thus affords the possibility of retrospective studies.

Adolescent↗
PubMed1989

Immunoelectron microscopic identification of human AA-type amyloid: exploration of various monoclonal AA-antibodies, methods of fixation, embedding and of other parameters for the protein-A gold method.

Using the postembedding protein-A gold technique ten monoclonal antibodies directed against amyloid-A protein (AA) were examined by immunoelectron microscopy to identify amyloid-A (AA) amyloid fibrils in plastic-embedded renal tissue of five patients and two controls. Two monoclonal antibodies (mc1, mc20) specifically labeled these amyloid deposits; two additional ones (mc4, mc13) bound with an intermediate rabbit anti-mouse IgG antiserum. These monoclonal anti-AA antibodies clearly separate amyloid fibrils from morphologically similar fibrils in the vicinity. Employing varying embedding media, fixation techniques, as well as etching and staining protocols, we adapted this method for the immunoelectron microscopic identification of AA-type amyloid fibrils and for the antigenic diagnosis of AA-type amyloid on routinely processed ultrathin sections.

Amyloidosis↗
PubMed1988

Direct determination of molecular ratios of peptides coupled via N-succinimidyl 3-(2-pyridyldithio)propionate to carrier proteins using high performance liquid chromatography.

A simple, rapid and reproducible method is presented for direct determination of the substitution ratio of a carrier protein with a synthetic nonradioactively labeled peptide. The peptide was covalently linked by a thiol group of a cysteine residue to the immunogenic carrier protein using the heterobifunctional reagent N-succinimidyl 3-(2-pyridyldithio)propionate. The substitution ratio was determined after reductive cleavage of the intermolecular disulfide bond between peptide and carrier and the amount of carrier and peptide quantitated directly by calibrated HPLC analysis within 15 min.

Animals↗
PubMed1988

Hemorrhagic bullous amyloidosis. A histologic, immunocytochemical, and ultrastructural study of two patients.

In patients with bullous hemorrhagic amyloidosis of the skin, the skin lesions were the first manifestations of a plasma cell dyscrasia. Both cases were characterized by similar clinical, histologic, and ultrastructural findings showing an intradermal blister within deposits of amyloid substances. Immunohistologic investigations with a panel of antibodies directed against amyloid fibril proteins showed reactivity of the amyloid deposits with an anti-A lambda serum in both patients.

Aged↗
PubMed1988

N-terminal amino acid sequence analysis indicates that isolated atrial amyloid is derived from atrial natriuretic peptide.

Isolated atrial amyloid, the most frequent senile cardiac amyloid type, was chemically analysed. Amyloid fibrils obtained from a patient (NIP) were extracted and the predominant low-molecular-weight polypeptide (approximately 3.5 kDa, designated ASc2 NIP) was isolated by size exclusion high performance liquid chromatography in 60% formic acid. N-Terminal amino acid sequence analysis of this polypeptide was identical to that of the atrial natriuretic peptide alpha-hANP for the first 12 residues determined.

Aged↗
PubMed1987

Human complement factor H: expression of an additional truncated gene product of 43 kDa in human liver.

The human complement factor H is an important factor in the control of the alternative pathway and also induces the stimulation of B cells and macrophages in vitro. Using a human factor H cDNA clone as probe, two factor H-specific transcripts of 4.4 and 1.8 kb were detected in four human livers. Both mRNAs were found independently of the expression of an acute phase marker SAA, in these livers, indicating that their presence is not linked to an acute phase state. The shorter transcript was cloned in two cDNA plasmids H-19 and H-20, lacking only seven amino acids of the N-terminus of the mature factor H protein. The deduced protein sequence showed that this protein is identical to the N-terminal portion of the large classical factor H of 150 kDa mol. mass. Parallel to the finding that the N-terminal sequence of factor H is expressed by two distinct mRNA species, evidence is presented that the C-terminal sequence is also contained on two different transcripts, the common 4.4-kb mRNA and an additional 1.0-kb mRNA. A novel, short form of human complement factor H of 43 kDa was detected in human sera which represents the translation product of the 1.8-kb factor H-specific mRNA detected in human liver. Five distinct epitopes detected with 6 monoclonal antibodies are present on both the 150-kDa factor H protein and the truncated 43-kDa molecule. We conclude that additional H-specific mRNAs are found in human liver and that at least one of them is translated yielding a truncated form of factor H.

Amino Acid Sequence↗
PubMed1987

Chemical heterogeneity of amyloid in the carpal tunnel syndrome.

140 biopsies from 108 patients afflicted with the carpal tunnel syndrome were studied, 27 of whom showed deposition of amyloid, in 6 of them to such an extent that the amyloid was considered significant in the pathogenesis of the carpal tunnel syndrome. Morphologically, vessels and ligaments were affected and especially the peritendinous structures. As it was always part of generalized amyloidosis, the amyloid in the carpal tunnel consisted immunohistologically of amyloid A in three cases (including one case with simultaneous amyloid deposition of the AA- and the AB-type), of amyloid A kappa in one case, of amyloid of prealbumin origin in seventeen cases and of AB-amyloid in eight cases. We also described for the first time the manifestation of generalized senile amyloidosis (ASs) in the carpal tunnel. Deposition of amyloid of beta-2-microglobulin type (AB) in the carpal tunnel was particularly frequent and massive.

Amyloid↗