Search PubMed⌕ Search

Biomedical subjects

R P Linke

Publications and source records attributed to R P Linke.

At least 109 records · Page 6Linked to original sources
PubMed1987

Hereditary amyloid polyneuropathy in north west Ireland.

Seven cases of chronic sensorimotor polyneuropathy due to amyloidosis, from 7 different families, are described, in addition to the pathology in a sibling of 1 case. The age of onset ranged from 55 to 72 years. Cardiac involvement, intermittent diarrhoea and syncopal attacks were a frequent occurrence. Motor conduction velocity showed a moderate degree of slowing in 5 of 6 cases studied and marked slowing in 1. Amyloid deposits were seen in nerve biopsy material of all 8 subjects and in rectal mucosa from 1. Immunohistochemical identification revealed AF (transthyretin-derived)--amyloid in all 8 instances, confirming the presence of type 1 familial amyloid neuropathy. The genealogical data supported this analysis. Six of the 8 cases originated in a small area of the north-west coast of County Donegal in Ireland. The remaining cases also originated in the same county.

Aged↗
PubMed1987

Beta 2-microglobulin, different fragments and polymers thereof in synovial amyloid in long-term hemodialysis.

Amyloid deposits of a patient with long-term hemodialysis were immunohistochemically identified as beta 2-microglobulin (beta 2m)-derived. Amyloid proteins were isolated from fibril concentrates from the synovia by HPLC permeation chromatography. Further analysis included dot immunoassay, immunodiffusion, SDS-polyacrylamide gel electrophoresis and Western blotting. Proteins with molecular masses of 8.5, 12, 17 and 24 kDa as well as polymers of higher molecular mass were detected. Neither the 24-kDa dimer nor the higher polymers could be significantly reduced by disulfide reagents. The N-terminal amino-acid sequence analyses of the two major proteins of 12 and 24 kDa showed the same two sequences each: one commencing with position 1 and the other with position 7 of beta 2m. These results suggest that limited proteolysis and polymer formation independent from interchain disulfide bridging, both play a role in the genesis of beta 2m-derived amyloid in the synovia.

Amino Acid Sequence↗
PubMed1987

Is the formation of AL-type amyloid promoted by structural peculiarities of immunoglobulin L-chains? Primary structure of an amyloidogenic lambda-L-chain (BJP-ZIM).

A Bence-Jones protein (Protein ZIM) was isolated from the urine of a patient with myeloma-associated amyloidosis. The amino-acid sequence of the variable region of the carboxymethylated protein was established by automatic stepwise degradation of the enzymatically deblocked protein and tryptic peptides thereof. The protein is of the lambda-type of human immunoglobulin L-chains and is closely homologous to subgroup I. In the course of the tryptic digestion a precipitate was formed which showed properties characteristic of amyloid, such as staining with Congo red and green birefringence in polarized light. High-performance liquid chromatography was applied to separate these peptides. The precipitate consists of two peptides which coincide with position 19-45 of the variable and 129-140 of the constant part, respectively. Possible implications of this finding are discussed in the context of amyloid formation after limited proteolytic digestion.

Amino Acid Sequence↗
PubMed1986

Amyloid kidney stones of uremic patients consist of beta 2-microglobulin fragments.

Urinary stones with amyloid structure, obtained from uremic patients, were analyzed according to molecular weight, amino acid sequence, and antigenic content. A major protein of approximately 7 kD, designated AB protein, was isolated by size exclusion using HPLC in 60% formic acid. AB protein reacted in immunodiffusion only with an antiserum to beta 2-microglobulin, with beta 2m spurring over AB protein. N-terminal amino acid sequence analysis defined two fragments homologous to beta 2m. One fragment commenced with Ile at position 7 and the other with Ser at position 20, with a cleavage point subsequent to a lysyl residue in both. It is concluded that beta 2m is a precursor of urinary amyloid stones and intratubular concretions of patients with preterminal and terminal renal failure; limited proteolysis is involved in AB amyloid generation.

Amino Acid Sequence↗
PubMed1986

Diagnosis of the type of amyloid in paraffin wax embedded tissue sections using antisera against human and animal amyloid proteins.

Different histochemical techniques were compared on paraffin wax embedded tissue sections for routine classification of amyloid; the following methods were used: potassium permanganate, the indirect immunoperoxidase method using polyclonal anti-human amyloid antisera (anti-AA, anti-A lambda, anti-A kappa and anti-AF) and the peroxidase-antiperoxidase (PAP) method using antisera against human, bovine, hamster and canine AA amyloid. Anti-human AA antiserum appeared to be a useful tool in this respect. Polyclonal anti-AL antisera may be helpful in diagnosing AL amyloid, but were less of value than anti-AA serum. Strong cross reactivity between anti-bovine AA antiserum and human AA amyloid deposits was found. This indicates that animal amyloid AA antisera can also be used for the diagnosis of AA amyloid in human tissues.

Adult↗
PubMed1986

Amyloid deposits in lymph nodes: a morphologic and immunohistochemical study.

In a series of approximately 80,000 lymph nodes, amyloid deposition was found in 18; 12 of those nodes were selected, on the basis of availability of specimens, for investigation by immunohistochemical typing to identify the protein of origin and by correlation with morphologic criteria and clinical information. Four patterns of amyloid deposition were identified: lymph node vessel involvement, follicular deposition, diffuse deposition, and a combination of follicular and diffuse deposition. All cases were classified immunohistochemically with the amyloid type-specific antisera anti-AA, anti-A lambda, anti-A kappa, anti-ASc1, and anti-AF. Immunoglobulin-derived protein (AL) in lymph nodes was found in every case of isolated amyloidosis, lymphoplasmacytic/lymphoplasmacytoid immunocytoma, plasmacytoma, and idiopathic amyloidosis. Among the cases of AL amyloidosis were nine of A lambda and one of the A kappa type. AA protein was present in two cases of reactive systemic amyloidosis. There was no useful morphologic correlation with the immunohistochemically identified amyloid types.

Aged↗
PubMed1986

Cardiac amyloid deposits in endomyocardial biopsies. Light microscopic, ultrastructural, and immunohistochemical studies.

In four patients with unexplained, abnormal thickening of the interventricular septum as demonstrated by echocardiography, right ventricular endomyocardial biopsy revealed unexpected cardiac amyloid deposits that resulted in increased myocardial thickness and rapidly progressive heart failure. Light microscopically, amyloid was observed in the subendocardial layer, interstitium, and walls of the intramural arterioles. Electron-microscopically, the amyloid fibrils were adjacent to the basement membranes of the heart muscle cells and the vascular smooth muscle cells. Immunohistochemical typing with specific antibodies against different amyloid fibril proteins on glutaraldehyde-fixed paraffin sections revealed different amyloid types. In two patients with generalized idiopathic amyloidosis and in two others with amyloidosis in multiple myeloma, the A-lambda form was diagnosed. In a fifth patient, AA-amyloidosis was found in familial Mediterranean fever with cardiac manifestation without thickening of the interventricular septum. The amyloid deposits were located almost exclusively within the walls of the myocardial arterioles. The amount of amyloid as observed in the myocardial biopsies correlates with the rapidly progressive cardiac failure. It is suggested that in patients with abnormal thickening of the interventricular septum of unknown origin the diagnosis should be clarified by endomyocardial biopsy.

Adult↗
PubMed1986

Immunohistochemical identification of generalized AA-amyloidosis in a mountain gazelle (Gazella gazella).

Generalized amyloidosis was diagnosed post-mortem in a mountain gazelle (Gazella gazella). To test whether the amyloid deposits consisted of amyloid-A fibril protein a series of monoclonal and polyclonal antibodies directed against amyloid-A fibril protein of different species was applied to formalin-fixed paraffin sections using the indirect immunoperoxidase technique. The immunohistochemical results showed a moderate cross-reaction of gazelle amyloid with human, murine, hamster, and canine amyloid-A fibril protein. A strong cross-reaction, however, was found with one of two monoclonal anti-human amyloid-A antibodies and with an antiserum against bovine amyloid-A fibril protein, the amyloid fibril protein of another ungulate. These results demonstrate the presence of amyloid-A fibril protein in the gazelle amyloid and illustrate the diagnostic value of cross-reacting anti-amyloid-A antibodies for the identification of amyloid-A-amyloidosis in species and in individuals in which amyloid has not yet been examined.

Adrenal Glands↗
PubMed1986

Immunochemical characterization of two activator proteins stimulating enzymic sphingomyelin degradation in vitro. Absence of one of them in a human Gaucher disease variant.

Two nonenzymic activator proteins shown previously to strongly stimulate enzymic sphingomyelin degradation in vitro were purified from human Gaucher type 1 and control spleen. Activator A1 (molecular mass 6,500 Da) had affinity for ConA-Sepharose, while activator A2 (molecular mass 3,500 Da) did not. Monospecific antibodies to each activator protein were prepared in rabbits by immunization with protein purified from type 1 Gaucher spleen. A1 and A2 activators from Gaucher type 1 spleen were shown to be immunochemically identical to A1 and A2 activators from control spleen. However, A1 and A2 activators, whether isolated from Gaucher type 1 or control spleen, were shown to be distinct proteins. Immunochemical examination of all collected fractions during the purification revealed the existence of a third activator (molecular mass 6,000 Da), which was antigenically identical to A1 activator but had no affinity for ConA-Sepharose. The two forms of A1 activator showed similar mobility on immunoelectrophoresis differing from that of A2 activator. Fibroblast extracts from controls and patients with different variants of Gaucher disease were investigated using immunodiffusion against antisera to A1 or A2 activator. In contrast to normal and Gaucher (types 1, 2 and 3) cell extracts, those of a Gaucher patient with normal glucosylceramidase activity had no visible precipitin line towards the antiserum against the two forms of A1 activator. The lack of crossreacting material to antibodies against A1 activator was confirmed by radial immunodiffusion and rocket immunoelectrophoresis. A1 activator stimulated the basal glucosylceramidase activity 5-6 fold in fibroblasts from this patient, whereas the normal effect was only a 1.2-1.5-fold stimulation. The immunological results together with the biochemical data provide evidence for the lack of an activator protein in a variant form of human Gaucher disease for the first time.

Adolescent↗
PubMed1986

[Amyloidosis of the A-kappa type].

A 73-year-old patient complained of increasing macroglossia and symmetrical enlargement of the submandibular region. A tongue biopsy showed typical deposits of amyloid by Congo red staining and polarization microscopy. Similar deposits were found in biopsy specimens of the submaxillary gland and the rectum. Electron microscopy revealed typical amyloid fibrils. With the indirect immunoperoxidase technique the amyloid was classified as being of immunoglobulin kappa-light-chain origin (A-kappa), because only anti-A kappa, but not anti-A lambda (several antisera of non-overlapping specificity), anti-ASc1 or anti-AF antisera were found to be reactive. Correspondingly, Bence Jones protein of the kappa type was found in the urine. In the bone marrow there was an increase in plasma cells of up to 10%. Cytostatic therapy with melphalan and methylprednisolone seemed to stop the progression of amyloid deposition.

Aged↗
PubMed1986

[Typing of amyloidoses intra vitam by tissue biopsy using antibodies. Report on 2 patients].

The value of the immunohistochemical classification of amyloid-syndromes has been illustrated in two patients with generalized amyloidosis. Chemical types and exact diagnosis were recognized in biopsies (and later necropsies) using antisera against different purified amyloid fibril proteins and the indirect immunoperoxidase technique. The first case, originally diagnosed as "perireticular" amyloid, was diagnosed as "Ak-amyloidosis with kappa-Bence-Jones-proteinuria without apparent B-cell malignoma", the second case as "AA-amyloidosis reactive to periodic fever". The diagnosis and possible therapeutic measures are discussed in the light of the new classification of amyloid syndromes.

Aged↗
PubMed1986

Tumor necrosis factor as effector molecule in monocyte mediated cytotoxicity.

A newly developed assay system which uses actinomycin D (Act D) pretreated Wehi 164 target cells allows for the measurement of human monocyte cytotoxicity in a 7-h 51Cr release assay. Using the monocyte specific monoclonal antibody M42 in a direct rosetting procedure we confirm herein that among human peripheral blood mononuclear cells cytotoxicity is restricted to monocytes. When applying stringent conditions that exclude exogenous lipopolysaccharide (LPS) we could demonstrate that as little as 0.1 ng of LPS per ml triggers this cytotoxicity. Further, a factor can be detected in supernatants of mononuclear cells which is also cytotoxic against Act D treated Wehi 164 cells. This cytotoxic factor can be triggered by LPS within 4 h, but at as low a LPS concentration as 0.001 ng/ml. Since one of the LPS triggered monocyte products is tumor necrosis factor (TNF), we tested the effect of recombinant TNF cloned from the U937 cell line and we could show potent lytic activity against Act D pretreated but not, or only minimally, against untreated Wehi 164 target cells. Recombinant TNF rapidly lysed the target with significant specific release occurring as early as after 3 h in the assay. By contrast, recombinant interleukin 1 gave no lysis while lymphotoxin derived from the RPMI 1788 cell line was effective. An affinity purified antiserum directed against TNF neutralized the lytic activity of recombinant TNF and also the cytotoxic factor produced by LPS triggered mononuclear cells, while the antiserum was ineffective against lymphotoxin. Further, the antiserum when added to the assay of effector cells and Act D treated Wehi 164 cells also completely ablated cytotoxic activity. Size fractionation of cytotoxic factor and recombinant TNF by high pressure liquid chromatography led to a superimposable peak of cytotoxicity in the molecular weight range of 9,500-17,000. Further, immunoblotting with the anti-TNF antibody revealed the same Mr 15,500-16,500 band for the recombinant TNF and LPS triggered cytotoxic factor. Taken together, our data demonstrate that the cytotoxic activity of human monocytes against Act D treated Wehi 164 is mediated entirely by a LPS triggered molecule that is very similar or identical to the human tumor necrosis factor. The assay system thus provides a powerful tool to analyze the biology of TNF in humans.

Cytotoxicity, Immunologic↗
PubMed1985

Bullous amyloidosis.

A patient with a 12-year history of a relapsing bullous dermatosis is presented. Unusual clinical features included urticarial erythema, conspicuous mottled hyper- and depigmentation, lichenification and ichthyosiform hyperkeratosis. Serum immunoglobulin E levels were elevated. Histological examination showing deposits of amyloid in the uppermost dermis confirmed the diagnosis of bullous amyloidosis. Ultrastructurally, blister formation occurred at the level of the lamina lucida. The amyloid did not react with a panel of antibodies directed against amyloid fibril proteins. No underlying systemic disease was found. The bullous eruption responded to prednisolone therapy.

Amyloid↗
PubMed1985

Immunochemical typing of amyloid deposits after microextraction from biopsies.

A simple procedure for identifying amyloid fibril proteins in biopsies and small tissue fragments is described. Amyloid fibrils from 21 patients with amyloid deposits (including 6 controls) were freed from soluble proteins and concentrated by a microextraction technique. The solubilized amyloid fibril proteins were then examined by immunodiffusion with antisera directed against amyloid fibril proteins (AA, A lambda, A kappa, ASc1, AF), cystatin C and beta 2-microglobulin. 9 out of 11 specimens with inconclusive immunohistochemical results, 5 other specimens, and 6 control specimens could clearly be typed with this method. Microextraction followed by immunochemical identification, therefore, can be considered an additional option for chemical amyloid classification in those cases in which immunohistochemical typing does not yield unequivocal results.

Amyloid↗
PubMed1984

Typing and subtyping of haptoglobin from native serum using disc gel electrophoresis in alkaline buffer: application to routine screening.

A method with which the six common phenotypes of human haptoglobin can be identified using unseparated serum is described. In contrast to other reported methods, both typing and subtyping of haptoglobin can be performed by polyacrylamide gel electrophoresis in alkaline buffer using 0.1-4.0 microliter of native serum with hemoglobin added. Haptoglobin-hemoglobin complexes are visualized by their peroxidase activity using benzidine and barium peroxide. This relatively inexpensive and fast method seems particularly well suited for the typing and subtyping of haptoglobin from minute amounts in large series of sera and other body fluids and thus may be useful in medical genetics and forensic medicine.

Adult↗
PubMed1984

Clinical value of immunohistochemistry with AF-antibody in the diagnosis of familial amyloid neuropathy.

Peripheral polyneuropathy associated with recurrent diarrhoea and orthostatic hypotension was observed in two unrelated German kinships and two sporadic cases. Congo red staining and polarization microscopy of biopsy specimens revealed amyloid deposits. Immunohistochemical investigation using the indirect immunoperoxidase staining with antisera to several purified amyloid fibril proteins showed a positive reaction with an antiserum to the prealbumin-related AF-amyloid in the families and one of the sporadic cases and with an antiserum to the immunoglobulin light chain amyloid (A lambda) in the other sporadic case. Therefore, the amyloid of the families and one of the sporadic cases was identified as the prealbumin-related AF amyloid, while the amyloid of the other sporadic case was of immunoglobulin origin. It is concluded that immunohistochemistry with antisera to the different amyloid proteins is useful in the differential diagnosis of amyloid neuropathy.

Adult↗
PubMed1984

Immunohistochemical identification and crossreactions of amyloid-A fibril protein in man and eleven other species.

Antisera were prepared in rabbits, sheep or chicken against purified amyloid fibril protein AA from man, mouse, stone marten, dog, cow and hamster. These antisera were tested by immunodiffusion against all purified antigens and applied to tissue sections containing amyloid from man, mouse, hamster, guinea pig, rabbit, cat, dog, mink, stone marten, pine marten, cow and horse. The binding of the antibodies to amyloid in tissue sections was assessed by the indirect immunoperoxidase method. The strongest reactions in the immunodiffusion and immunohistochemical methods were found between amyloid deposits of members of a given species and an antibody raised against protein AA from the same species. In contrast to the lack of cross-reactivity in immunodiffusion (except in the mouse-man relationship), extensive cross-reactions were observed immunohistochemically in phylogenetically related species, e.g. between stone marten, pine marten and mink, or between hamster and mouse. However, cross-reactions were also observed in combinations such as man-mouse, man-dog, man-cat, mouse-horse, and dog-cow. In addition, individual antisera showed variations in immunohistochemical reactivity with amyloid deposits of different members of one given species. Moreover, antisera prepared in rabbits reacted more restrictedly than those prepared in sheep, while rabbit antisera against any AA-protein did not react with rabbit amyloid. Finally, the widest degree of cross-reactivity including almost all mammalian species investigated was observed with a chicken antiserum to human amyloid AA protein.

Amyloid↗