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At least 973 records · Page 54Linked to original sources
PubMed1981

Immunocytochemical identification of amyloid in formalin-fixed paraffin sections.

Formalin-fixed paraffin sections of livers, spleens and kidneys from patients with primary, secondary and familial amyloidosis as well as from a casein-induced murine amyloid model were analysed by an immunocytochemical (unlabeled antibody enzyme) method utilizing antisera to amyloid-related proteins. All amyloid deposits of all amyloid types showed positive reactions with anti-AP of the respective species. Positive reaction of anti-human AA to human secondary amyloid deposits and of anti-mouse AA to the deposits of casein-induced murine amyloid was also observed, but there was no species cross reactivity. No significant deposition of the reaction products was produced by anti-immunoglobulin light chains on deposits of any amyloid type, or by anti-AA in the tissues from primary or familial amyloidosis. The results indicate that amyloid proteins AA and AP can survive as antigens through routine histologic preparation, that anti-AP can be a universal marker for deposits of any amyloid type within the same species, and that AA-type amyloid can be identified by this method while there may as yet be no feasible universal marker for the AL-type at present.

Amyloid↗
PubMed1999

Prolonged exposure of pancreatic beta cells to raised glucose concentrations results in increased cellular content of islet amyloid polypeptide precursors.

Most non-insulin dependent diabetic patients have amyloid deposits in their pancreatic islets. It is not known whether chronic hyperglycaemia contributes to the formation of amyloid fibrils from the islet amyloid polypeptide that is produced by the pancreatic beta cells. Since islet amyloid exhibits islet amyloid polypeptide precursors immunoreactivity, we examined whether sustained in vitro exposure to raised glucose increases the abundance of these precursors in human beta cells. After 6 days stimulation with 20 mmol/l glucose the cellular content of insulin but not islet amyloid polypeptide was decreased leading to an increase in the ratio of the latter over insulin (3.0 +/- 0.6 vs 1.8 +/- 0.3 after 6 mmol/l glucose culture, p < 0.05). Similar changes occurred in rat beta cells cultured for 3 days in the presence of 20 mmol/l glucose plus 3-isobutyl-1-methylxanthine. Western blot analysis of cellular islet amyloid polypeptide after prolonged exposure to high glucose indicated the presence of higher proportions of its precursor- and intermediate forms. In human beta cells cultured in 20 mmol/l glucose, the major form corresponds to an intermediate species which exhibits an immunoreactivity for the N-flanking peptide, as is also the case in islet amyloid. We concluded that prolonged in vitro exposure of beta cells to raised glucose concentrations increases the relative proportion of islet amyloid polypeptide over insulin, as well as of its precursors over the mature form of islet amyloid polypeptide.

1-Methyl-3-isobutylxanthine↗
PubMed1989

Fluorometric determination of amyloid fibrils in vitro using the fluorescent dye, thioflavin T1.

We used a fluorometric method to examine amyloid fibrils, in vitro. These fibrils in the case of both murine senile and secondary amyloidosis were purified to apparent homogeneity from the water-suspended fraction of the liver of senescence-accelerated mouse, using sucrose density ultracentrifugation, and then the following assays were performed. In the absence of amyloid fibrils, thioflavine T fluoresced faintly at the excitation and emission maxima of 350 and 438 nm, respectively. In the presence of amyloid fibrils, thioflavine T fluoresced brightly at the excitation and emission maxima of 450 and 482 nm, respectively, and the fluorescence change was linear from 0 to 2.0 micrograms/ml amyloid fibrils. This fluorescence was maximal around pH 9.0. Fluorescence intensity in the presence of a constant amount of amyloid fibrils reached a plateau with increase in the thioflavine T concentration. Normal high density lipoproteins which contain apo A-II, the precursor of amyloid fibrils in murine senile amyloidosis, and acute phase high density lipoproteins which contain serum amyloid protein A, the precursor of amyloid fibrils in secondary amyloidosis, showed little fluorescence. The fluorescence was considerably diminished when structure of the amyloid fibrils was disrupted by guanidine-HCl treatment. This method will be useful for the determination of amyloid fibrils in vitro.

Amyloid↗
PubMed1990

Beta-amyloid precursor detected in human cerebral cortex.

1. Amyloid deposition is one of the pathologic hallmarks of Alzheimer's disease. Since the isolation of the beta-amyloid gene, which revealed that the amyloid forming 4 kD protein is part of a larger precursor, interest has focused on the process by which amyloid is generated and deposited. 2. The authors have developed an immunologic means of detecting amyloid precursor proteins in human brain. 3. The method involves the expression of human beta-amyloid precursor cDNA in a recombinant vaccinia virus, so that antibodies are produced against the precursor proteins in their native forms. 4. By using this expression system, the amyloid precursor immunogens incorporate post-translational modifications that normally occur in vivo; this cannot be achieved with small synthetic peptides. 5. Using antibodies to the 695 residue amyloid precursor, we have detected using Western blot analysis a protein of approximately 120 kD in samples of cerebral cortex from three subjects with Alzheimer's disease and one control subject. 6. Additional antibodies to other amyloid-related proteins have been developed. These are being used to assess the differential expression of the various amyloid precursors and subdomains in additional cases.

Adult↗
PubMed1996

'In vitro' amyloid fibril formation from transthyretin: the influence of ions and the amyloidogenicity of TTR variants.

The mechanisms of amyloid formation in Familial Amyloidotic Polyneuropathy (FAP) are unknown, as well as the factors determining the development of this pathology. To get some insights into this process, we have first tested a fluorimetric assay with thioflavine T, as a quantitative method for transthyretin (TTR) amyloid estimation, using amyloid isolated from post-mortem tissues of a FAP patient. Then production of amyloid fibrils from soluble TTR was achieved by acidification and optimized for protein concentration and pH. The effect of different ions such as metal and sulphate ions in the process of amyloid formation from wild type TTR was compared using a kinetic assay. Under the conditions tested sulphate diminishes the amount of amyloid formed from wild type TTR and in addition appears to promote aggregation of preexisting amyloid fibrils. The relative amyloidogenicity of three TTR variants, TTR Met30, TTR Pro55 and TTR Met119 respectively, was evaluated using a pH dependent assay. It was shown that the Pro55 variant is highly susceptible to amyloid formation as compared to the wild type protein; on the contrary, the Met119 variant is more resistant than the other TTR proteins towards precipitation into amyloid. These results are in agreement with the pathological conditions associated with these mutations. This type of assay has a wide application for testing the influence of other factors, such as therapeutical agents, on amyloid formation.

Amyloid↗
PubMed2006

Linker histone H1 binds to disease associated amyloid-like fibrils.

Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most prevalent neurodegenerative diseases of the central nervous system. These two diseases share a common feature in that a normally soluble peptide (amyloid-beta) or protein (alpha-synuclein) aggregates into an ordered fibrillar structure. As well as structural similarities observed between fibrillar aggregates related to these diseases, common pathological processes of increased oxidative injury, excitotoxicity and altered cell cycle are also evident. It was the aim of this study to identify novel interacting proteins to the amyloid-like motif and therefore identify common potential pathways between neurodegenerative diseases that share biophysical properties common to classical amyloid fibrils. Optimal ageing of recombinant proteins to form amyloid-like fibrils was determined by electron microscopy, Congo red birefringement and photo-induced cross-linking. Using pull-down assays the strongest detected interacting protein to the amyloid-like motifs of amyloid-beta, alpha-synuclein and lysozyme was identified as histone H1. The interaction with the amyloid-like motif was confirmed by techniques including surface plasmon resonance and immunohistochemistry. Histone H1 is known to be an integral part of chromatin within the nucleus, with a primary role of binding DNA that enters and exits from the nucleosome, and facilitating the shift in equilibrium of chromatin towards a more condensed form. However, phosphorylated histone H1 is predominantly present in the cytoplasm and as yet the functional significance of this translocation is unknown. This study also found that histone H1 is localised within the cytoplasm of neurons and astrocytes from areas affected by disease as well as amyloid plaques, supporting the hypothesis that histone H1 favoured binding to an ordered fibrillar motif. We conclude that the binding of histone H1 to a general amyloid-like motif indicates that histone H1 may play an important common role in diseases associated with amyloid-like fibrils.

Alzheimer Disease↗
PubMed1997

Animal models of cerebral beta-amyloid angiopathy.

Cerebral amyloid angiopathy (CAA) is a significant risk factor for hemorrhagic stroke in the elderly, and occurs as a sporadic disorder, as a frequent component of Alzheimer's disease, and in several rare, hereditary conditions. The most common type of amyloid found in the vasculature of the brain is beta-amyloid (A beta), the same peptide that occurs in senile plaques. A paucity of animal models has hindered the experimental analysis of CAA. Several transgenic mouse models of cerebral beta-amyloidosis have now been reported, but only one appears to develop significant cerebrovascular amyloid. However, well-characterized models of naturally occurring CAA, particularly aged dogs and non-human primates, have contributed unique insights into the biology of vascular amyloid in recent years. Some non-human primate species have a predilection for developing CAA; the squirrel monkey (Saimiri sciureus), for example, is particularly likely to manifest beta-amyloid deposition in the cerebral blood vessels with age, whereas the rhesus monkey (Macaca mulatta) develops more abundant parenchymal amyloid. These animals have been used to test in vivo beta-amyloid labeling strategies with monoclonal antibodies and radiolabeled A beta. Species-differences in the predominant site of A beta deposition also can be exploited to evaluate factors that direct amyloid selectively to a particular tissue compartment of the brain. For example, the cysteine protease inhibitor, cystatin C, in squirrel monkeys has an amino acid substitution that is similar to the mutant substitution found in some humans with a hereditary form of cystatin C amyloid angiopathy, possibly explaining the predisposition of squirrel monkeys to CAA. The existing animal models have shown considerable utility in deciphering the pathobiology of CAA, and in testing strategies that could be used to diagnose and treat this disorder in humans.

Alzheimer Disease↗
PubMed2003

The use of formic acid to embellish amyloid plaque detection in Alzheimer's disease tissues misguides key observations.

We compared our heat pretreatment method to the widely used formic acid pretreatment technique to immunohistochemically detect amyloid in control and Alzheimer's disease brain tissues. Both methods detected amyloid in plaques, neurons, ependymal cells, circulating monocytes, vascular smooth muscle and endothelial cells. Although there were no observable differences in the intensity of the amyloid labeling in these cell types using both pretreatment methods, there were considerable differences in the intensity of amyloid immunolabeling in the plaques. The formic acid produced much more intense amyloid labeling in the plaques than the heat method. With the heat method, the intensity of the amyloid labeling in the plaques was similar to that detected in nearby neurons suggesting a neuronal origin of plaques. Conversely, the intensity of the amyloid in nearby neurons and plaques was drastically different using the formic acid suggesting unique origins of amyloid. The obvious benefits of formic acid for increasing the sensitivity of amyloid plaque immunolabeling may artifactually emphasize plaques over amyloid-containing cells during analyses.

Aged↗
PubMed2000

Quantitative histological analysis of amyloid deposition in Alzheimer's double transgenic mouse brain.

The development of transgenic mice has created new opportunities for the generation of animal models of human neurodegenerative diseases where previously there was no animal counterpart. The first successful transgenic mouse model of Alzheimer's disease expressed increased levels of mutant human amyloid precursor protein, exhibiting neuritic-type amyloid deposits and behavioral deficits at six to nine months of age. More recently, it was shown that transgenic mice expressing both mutant human amyloid precursor protein and presenilin 1 exhibit neuritic-type amyloid deposits and behavioral deficits in as little as 12 weeks. This accelerated Alzheimer phenotype greatly reduces the time necessary to conduct preclinical drug trials, as well as animal housing costs. The purpose of this study was to quantify the deposition of amyloid in five regions of the cortex and two regions of the hippocampus of transgenic mice expressing amyloid precursor protein (K670N, M671L) and presenilin 1 (M146L) mutations at various ages, using quantitative methods of confocal laser scanning microscopy and image analysis. Amyloid burden, expressed as the percentage area occupied by thioflavin S-positive amyloid deposits, increased an average of 179-fold from 12 to 54 weeks of age (0.02+/-0.01% to 3.57+/-0.29%, mean+/-S.E.M., respectively) in five regions of the cortex and two of the hippocampus. This was a function of increases in both deposit number and size. This transgenic mouse provides an ideal animal model for evaluating the efficacy of potential therapeutic agents aimed at reducing amyloid deposition, such as inhibitors of amyloid fibril formation or secretase inhibitors.

Alzheimer Disease↗
PubMed1998

Alzheimer's amyloid precursor protein alpha-secretase is inhibited by hydroxamic acid-based zinc metalloprotease inhibitors: similarities to the angiotensin converting enzyme secretase.

The 4 kDa beta-amyloid peptide that forms the amyloid fibrils in the brain parenchyma of Alzheimer's disease patients is derived from the larger integral membrane protein, the amyloid precursor protein. In the nonamyloidogenic pathway, alpha-secretase cleaves the amyloid precursor protein within the beta-amyloid domain, releasing an extracellular portion and thereby preventing deposition of the intact amyloidogenic peptide. The release of the amyloid precursor protein from both SH-SY5Y and IMR-32 neuronal cells by alpha-secretase was blocked by batimastat and other related synthetic hydroxamic acid-based zinc metalloprotease inhibitors, but not by the structurally unrelated zinc metalloprotease inhibitors enalaprilat and phosphoramidon. Batimastat inhibited the release of the amyloid precursor protein from both cell lines with an I50 value of 3 microM. Removal of the thienothiomethyl substituent adjacent to the hydroxamic acid moiety or the substitution of the P2' substituent decreased the inhibitory potency of batimastat toward alpha-secretase. In the SH-SY5Y cells, both the basal and the carbachol-stimulated release of the amyloid precursor protein were blocked by batimastat. In contrast, neither the level of full-length amyloid precursor protein nor its cleavage by beta-secretase were inhibited by any of the zinc metalloprotease inhibitors examined. In transfected IMR-32 cells, the release of both the amyloid precursor protein and angiotensin converting enzyme was inhibited by batimastat, marimastat, and BB2116 with I50 values in the low micromolar range, while batimastat and BB2116 inhibited the release of both proteins from HUVECs. The profile of inhibition of alpha-secretase by batimastat and structurally related compounds is identical with that observed with the angiotensin converting enzyme secretase suggesting that the two are closely related zinc metalloproteases.

Alzheimer Disease↗
PubMed2001

Endosomal sorting of amyloid precursor protein-P-selectin chimeras influences secretase processing.

Amyloid beta protein, the major component of the senile plaques in Alzheimer's disease, is generated by secretory and endocytic processing of amyloid precursor protein. Internalized amyloid precursor protein either recycles to the plasma membrane, where alpha-secretase resides, or moves to acidic compartment(s) for beta-secretase exposure. While the trans-Golgi network contains beta-secretase activity, recent examination of the subcellular distribution of this proteinase, called BACE, has led to the suggestion that beta-secretase activity might also reside at the plasma membrane and in endosomes. To examine the role of endocytic compartments in beta-secretase processing of amyloid precursor protein, the wild-type and endosomal sorting mutant P-selectin cytoplasmic domains were used to control movement of amyloid precursor protein through endosomes. Amyloid precursor protein/P-selectin, which is sorted from early to late endosomes, undergoes significantly less alpha-secretase cleavage, and more beta-secretase cleavage, than amyloid precursor protein/P-selectin768A, a mutant that recycles more efficiently to the cell surface. Our results demonstrate that endosomal sorting influences relative exposure of the amyloid precursor protein/P-selectin chimeras to alpha- and beta-secretase activities, and suggest that, because delivery to late endocytic compartments favors beta-secretase processing of amyloid precursor protein, there is likely limited beta-secretase activity in early endosomes or at the cell surface. We propose that the trans-Golgi network may be involved in both secretory and endocytic generation of amyloid beta protein.

Alzheimer Disease↗
PubMed1988

Molecular cloning of amyloid cDNA derived from mRNA of the Alzheimer disease brain: coding and noncoding regions of the fetal precursor mRNA are expressed in the cortex.

To gain insight into factors associated with the excessive accumulation of beta-amyloid in the Alzheimer disease (AD) brain, the present studies were initiated to distinguish between a unique primary structure of the AD-specific amyloid precursor mRNA vis a vis other determinants that may affect amyloid levels. Previous molecular cloning experiments focused on amyloid derived from sources other than AD cases. In the present work, we cloned and characterized amyloid cDNA derived directly from AD brain mRNA. Poly(A)+ RNA from AD cortices was used for the preparation of lambda gt11 recombinant cDNA libraries. An insert of 1564 nucleotides was isolated that included the beta-amyloid domain and corresponded to 75% of the coding region and approximately equal to 70% of the 3'-noncoding region of the fetal precursor amyloid cDNA reported by others. On RNA blots, the AD amyloid mRNA consisted of a doublet of 3.2 and 3.4 kilobases. In control and AD cases, the amyloid mRNA levels were nonuniform and were independent of glial-specific mRNA levels. Based on the sequence analysis data, we conclude that a segment of the amyloid gene is expressed in the AD cortex as a high molecular weight precursor mRNA with major coding and 3'-noncoding regions that are identical to the fetal brain gene product.

Aged↗
PubMed2004

Targeting prion amyloid deposits in vivo.

The diagnosis of prion diseases in humans is challenging due to a lack of specific and sensitive non-invasive tests. Many forms of human prion disease including variant Creutzfeldt-Jakob disease (vCJD), Gerstmann-Sträussler-Scheinker (GSS) syndrome, and 10% of sporadic CJD cases are associated with amyloid deposition. Several positron emission tomography (PET) ligands have recently been developed to directly image beta-amyloid associated with Alzheimer disease. One of them, methoxy-X04, is a fluorescent derivative of Congo red with high binding affinity toward amyloid fibrils and good blood-brain barrier permeability. Using methoxy-X04, we investigated whether amyloid-targeting ligands can be also employed for direct imaging of amyloid deposits associated with some prion diseases. Such a method could potentially become a novel diagnostic approach for these conditions. Studies were performed on MB mice infected with the 87V mouse-adapted scrapie strain. Labeling of PrP amyloid plaques in brains of presymptomatic and symptomatic mice was demonstrated using in vivo transcranial two-photon microscopy after systemic administration of methoxy-X04. During real-time imaging, PrP amyloid deposits could be clearly distinguished 15 min after intravenous administration of methoxy-X04. The ligand showed rapid clearance from brain areas that did not contain amyloid deposits. PrP amyloid deposits could also be detected by direct application of methoxy-X04 on cerebellar sections from GSS patients. These results suggest that methoxy-X04 or similar derivatives could be used as PET imaging agents to improve the diagnosis of human prion diseases associated with amyloid deposition.

Alkenes↗
PubMed2004

The immune modulator FTY720 targets sphingosine-kinase-dependent migration of human monocytes in response to amyloid beta-protein and its precursor.

Accumulation of inflammatory mononuclear phagocytes in Alzheimer's senile plaques, a hallmark of the innate immune response to beta-amyloid fibrils, can initiate and propagate neurodegeneration characteristic of Alzheimer's disease. Phagocytes migrate toward amyloid beta-protein involving formyl peptide receptor like-1-dependent signaling. Using human peripheral blood monocytes in Boyden chamber micropore filter assays, we show that the amyloid beta-protein- and amyloid beta-precursor protein-induced migration was abrogated by dimethylsphingosine, a sphingosine kinase inhibitor. Amyloid beta-protein stimulated in monocytes the gene expression for sphingosine-1-phosphate receptors 2 and 5, but not 1, 3, and 4. FTY720 that acts as a sphingosine-1-phosphate receptor agonist after endogenous phosphorylation by sphingosine kinase, as well as various neuropeptides that are known to be monocyte chemoattractants, dose-dependently inhibited amyloid beta-protein-induced migration. These data demonstrate that the migratory effects of beta-amyloid in human monocytes involve spingosine-1-phosphate signaling. Whereas endogenous neuropeptides may arrest and activate monocytes at sites of high beta-amyloid concentrations, interference with the amyloid beta-protein-dependent sphingosine-1-phosphate pathway in monocytes by FTY720, a novel immunomodulatory drug, suggests that FTY720 may be efficacious in beta-amyloid-related inflammatory diseases.

1-Methyl-3-isobutylxanthine↗
PubMed1986

Immunohistochemical study of islet amyloid in diabetes mellitus.

Amyloid was isolated from islets of amyloidotic pancreata of monkey and human beings by solubilization of non-amyloid materials from the pancreas and digestion of contaminating collagen and elastin. The resulting pellet was estimated to be greater than 90% pure islet amyloid. Antibodies specific for monkey islet amyloid and for monkey and human liver amyloid A (AA) were raised in rabbits. Immunohistochemical reaction using the peroxidase antiperoxidase method demonstrated that amyloidotic pancreas reacted with both anti-AA and anti-islet amyloid antibodies. Although the antibodies are specific toward antigens, they cross-react with tissues from human and monkeys. The immunochemical results suggest the possibility that more than one kind of amyloid is associated with islet amyloidosis, but that a significant portion of the islet amyloid is related to AA. Preliminary chemical analysis indicated that islet amyloid is enriched with hexosamines while AA contains both hexosamines and hexoses. Establishment of the islet amyloid composition(s) can give insight into its source and its role in diabetes in Macaca nigra and human beings.

Amyloid↗
PubMed2006

Untangling the role of amyloid in atherosclerosis.

PURPOSE OF REVIEW: Amyloid deposits are a defining feature of several age-related and debilitating diseases. Their widespread presence in atherosclerotic plaques suggests a potential role in lesion development. This review discusses the proteins known to accumulate in atheroma and examines the evidence that amyloid-like structures activate macrophage signaling pathways linked to inflammation and prothrombotic potential. RECENT FINDINGS: Numerous proteins that accumulate in atherosclerotic plaques form amyloid fibrils in vivo, including apolipoproteins, beta-amyloid, and alpha1-antitrypsin. In addition, oxidation or enzymatic modification of low-density lipoproteins induces a structural reorganization of the particle, including the acquisition of amyloid-like properties. Similarly, glycation of serum albumin, as observed in diabetes, is accompanied by the formation of aggregates with all the hallmarks of amyloid. Several receptors implicated in atherogenesis modulate the fate of amyloid fibrils by mediating their clearance (scavenger receptors A and B-I), activating inflammatory signaling cascades (receptor for advanced glycation endproducts), or both (CD36). Finally, recent studies indicate that amyloid deposition accelerates diet-induced atherosclerosis in mice. SUMMARY: Given the substantial evidence that amyloid fibrils or preamyloidogenic species are cytotoxic, the aberrant deposition of amyloid in the intima may be pathologically important in vascular inflammation and the promotion of atherosclerosis.

Amyloid↗
PubMed1997

Relationship between apolipoprotein E and the amyloid deposits and dystrophic neurites of Alzheimer's disease.

Although the inheritance of certain apolipoprotein E (ApoE) alleles has been recognized as a genetic risk factor for Alzheimer's disease, the role of ApoE in the pathology underlying this disease is unclear. Several reports have emphasized the association of ApoE with either beta-amyloid plaque formation or the development of neurofibrillary pathology. Utilization of multiple label immunohistochemical methods enabled us to examine directly the localization of ApoE immunoreactivity relative to beta-amyloid plaques, dystrophic neurites and neurofibrillary tangles. In Alzheimer's disease cases, beta-amyloid plaques showing high ApoE immunoreactivity were localized to layers II, III and V of the neocortex. In layer I, beta-amyloid plaques were unlabelled for ApoE relative to beta-amyloid. Dense core plaques labelled for beta-amyloid often had only the central portions labelled for ApoE. Conversely, ApoE labelled spherical structures within some plaques were not immunoreactive for beta-amyloid or dystrophic neurite markers. Unlike beta-amyloid labelled plaques, all ApoE immunoreactive plaques were associated with dystrophic neurites. In preclinical Alzheimer's disease cases, most plaques were double labelled for beta-amyloid and ApoE. ApoE did not label dystrophic neurites or the early stages of neurofibrillary tangle formation, indicating that ApoE may not be directly involved in neurofibrillary pathology. The specific presence of ApoE in plaques associated with dystrophic neurites in demented patients suggests that ApoE may contribute toward a higher degree of beta-amyloid fibrillogenesis, enhancing the ability of certain plaques to cause damage to surrounding axons.

Aged↗
PubMed1981

Structure and antigenic behaviour of kappa I-immunoglobulin light-chain amyloid proteins.

N-terminal amino acid sequence analysis of three amyloid fibril subunit proteins from three different patients revealed a primary structure homologous to KI immunoglobulin light chains. In double immunodiffusion an antiserum against one of these amyloid proteins reacted with all three amyloids showing one line of identity, while an antiserum against one of the other amyloid proteins reacted with only one of the nonhomologous amyloids, appearing as partial identity, These two antisera did not react with any amyloid of lambda I, lambda IV or lambda VI type. The results confirm previous experiments, in which it has been shown that some antisera against amyloid proteins of immunoglobulin origin give a reaction of identity with other amyloids in the same immunoglobulin subgroup, probably owing to subgroup specific antigenic determinants in the variable segments. It was found that the distribution of amyloid varied widely among the three patients. There does not seem to be any correlation between the type of manifestation of amyloidosis and the type of immunoglobulin light chain forming the amyloid fibril.

Aged↗