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PubMed2000

Amyloidogenicity and neurotoxicity of peptides corresponding to the helical regions of PrP(C).

An alpha-helical to beta-sheet conformational change in the prion protein, PrP(C), is believed to be causative in transmissible spongiform encephalopathies. Recent nuclear magnetic resonance structures of PrP(C) have identified three helical regions in the normal full-length protein. We have synthesised peptides corresponding to these helical regions (PrP144-154, helical region one; PrP178-193, helical region two; and PrP198-218, helical region three). Circular dichroism results show that the peptide corresponding to helical region one is unstructured, while peptides corresponding to the second and third helical regions have a high propensity to form beta-sheet structure in a pH-dependent manner in aqueous solutions. Peptides corresponding to the second helical region, PrP180-193 and PrP178-193, are the only ones that form amyloid by electron microscopy and congo red birefringence. PrP178-193 and the amyloidogenic Alzheimer's disease Abeta25-25 peptide were found to promote Cu (II)-induced lipid peroxidation and cytotoxicity in primary neuronal cultures, while PrP144-154, PrP198-218 and the nonamyloidogenic Abeta1-28 had no effect on Cu (II) toxicity. There was no increase in toxicity induced by PrP178-193 in cultures treated with Fe (II) or hydrogen peroxide, indicating a preferential modulatory effect on Cu (II) toxicity by PrP178-193. The data suggest that the PrP178-193 peptide has both structural and bioactive properties in common with Abeta25-35 and that the second putative helical region of PrP could be involved in modulation of Cu (II)-mediated toxicity in neurons during prion disease.

Amyloid beta-Peptides↗
PubMed2002

Whole-column imaging capillary electrophoresis of proteins with a short capillary.

Whole-column imaging capillary electrophoresis with a short capillary is discussed. A short capillary (3-6 cm) coated with either fluorocarbon or polyacrylamide was used as a separation capillary. The whole capillary was illuminated with 280 nm light, and the transmitted light was monitored by a linear charge-coupled device (CCD). For the short capillary, hydrodynamic flow caused by a subtle height difference between the anodic and cathodic reservoirs affected the sample migration in the capillary greatly. Several sample injection methods, including use of a cross connection, sealing of the capillary ends with a gel, and use of a gel-filled capillary, have been discussed. The experimental results showed that the peak height decreased and peak width increased with the electromigration distance. Therefore, higher sensitivity was obtained in a short capillary rather than a long capillary. The whole-column imaging CE with the short capillary has been applied for the study of conjugation reactions of protein cytochrome c with sodium dodecyl sulfate (SDS) and the dye Congo Red. The method has also been used for in situ monitoring of the electrophoretic protein desorption process. Our technique is a unique tool for the study of protein binding reactions and the interaction between analyte and inner wall of the capillary.

Adsorption↗
PubMed2001

A deceptive case of amyloid myopathy: clinical and magnetic resonance imaging features.

Amyloid myopathy is a well-described, increasingly recognized clinical entity. Similar to inflammatory myopathies, amyloid myopathy presents with proximal muscle weakness and can be associated with elevated levels of muscle enzymes. We report the case of a 58-year-old woman who, at presentation to her physician with proximal muscle weakness and congestive heart failure, was antinuclear antibody positive and had muscle biopsy findings "consistent with inflammatory myopathy." She was referred to Johns Hopkins University Medical Center with the diagnosis of polymyositis. Further investigation revealed a monoclonal gammopathy, a unique patterning of subcutaneous fat reticulation and hypodense bone marrow changes on magnetic resonance imaging (MRI), and an endocardial biopsy sample that was positive for light chain amyloid deposition. Paraffin sections of the muscle biopsy sample from the time of her original presentation were obtained, and Congo red staining showed diffuse amyloid deposition throughout the sample, but no inflammation. This case not only illustrates that proximal muscle weakness due to primary amyloid myopathy (as found in light chain amyloidosis and transthyretin amyloidosis) can mimic that of polymyositis, but also shows that unique findings on MRI can alert the clinician to the diagnosis of amyloidosis prior to muscle biopsy.

Amyloidosis↗
PubMed1991

Intracerebral hemorrhage related to cerebral amyloid angiopathy and t-PA treatment.

Tissue plasminogen activator (t-PA) has been approved as thrombolytic therapy for the treatment of acute myocardial infarction, but this agent can cause serious bleeding complications including intracerebral hemorrhages. Mechanisms underlying the development of these hemorrhages have not been clarified. We report a patient who developed two intracerebral hemorrhages shortly after receiving t-PA for the treatment of an acute myocardial infarction, and who was found to have cerebral amyloid angiopathy at autopsy. Staining of cortical sections with Congo red and an antibody directed against beta amyloid protein (A4 peptide) disclosed specific involvement of most of the subarachnoid and superficial cortical vessels in the region of the two hemorrhages. Based on the findings in this patient and in 6 additional patients reported recently, it is likely that cerebral amyloid angiopathy plays a pathogenic role in some intracerebral hemorrhages associated with the administration of t-PA. The cautious use of t-PA with heparin in patients who are elderly or demented may be advisable.

Amyloid beta-Peptides↗
PubMed1993

beta-Amyloid precursor epitopes in muscle fibers of inclusion body myositis.

Sporadic inclusion body myositis (IBM) and hereditary inclusion body myopathy (hIBM) are severe and progressive muscle diseases, characterized pathologically by vacuolated muscle fibers that contain 15- to 21-nm cytoplasmic tubulofilaments (CTFs). Those vacuolated muscle fibers also contain abnormally accumulated ubiquitin and beta-amyloid protein (A beta), and they contain amyloid in beta-pleated sheets as indicated by Congo red and crystal violet positivity. Using several well-characterized antibodies, we have now demonstrated that, in addition to A beta, two other epitopes, N-terminal and C-terminal, of the beta-amyloid precursor protein (beta PP) are abnormally accumulated in IBM vacuolated muscle fibers and similarly in hIBM. At the light microscopy level, immunoreactivities of N- and C-epitopes of beta PP closely colocalized with A beta and ubiquitin immunoreactivities. However, by immunogold electronmicroscopy, even though N-, C-, and A beta epitopes of beta PP and ubiquitin colocalized at the amorphous and dense floccular structures, only A beta was localized to the 6- to 10-nm amyloid-like fibrils and only ubiquitin was localized to CTFs. beta PP immunoreactive structures were often in proximity to CTFs, but CTFs themselves never contained beta PP immunoreactivities. The fact that A beta but not C- or N-terminal epitopes of beta PP localized to the 6- to 10-nm amyloid-like fibrils suggests that free A beta might be generated during beta PP processing and, after aggregation, may be responsible for the amyloid present within IBM muscle fibers. Our study demonstrates that three epitopes of beta PP accumulate abnormally in diseased human muscle, and therefore this phenomenon is not unique to Alzheimer's disease, Down's syndrome brain, and Dutch-type cerebrovascular amyloidosis.

Adolescent↗
PubMed1998

Amyloid myopathy: an underdiagnosed entity.

Amyloidosis can involve multiple organs, including kidney, heart, peripheral nerve, skin, joints, and skeletal muscle, but rarely presents as a myopathy. We studied 13 adults with muscle weakness for between 3 months and 4 years in whom the diagnosis of systemic amyloidosis was unsuspected before or until just before the time of the muscle biopsy. All muscle specimens demonstrated congophilic deposits around blood vessels and muscle fibers, some necrotic and regenerating fibers, and signs of mild denervation. Immunostains in 10 patients revealed immunoglobulin amyloidosis in 7 and gelsolin amyloidosis in 1. Apolipoprotein E co-localized with the congophilic deposits in all 10, and a C-terminal epitope of the beta-amyloid precursor protein was detected in 6. The frequency of the diagnosis of amyloid myopathy increased 10-fold when we adopted the fluorescent Congo red stain as a routine procedure in assessing muscle biopsy specimens.

Adult↗
PubMed1992

Utility of high-resolution ultrasound for the diagnosis of dialysis-related amyloidosis.

OBJECTIVE: To evaluate the utility of real-time, high-resolution ultrasound of the shoulder in the diagnosis of dialysis-related amyloidosis. METHODS: We performed a case series study of 2 groups of patients seen at a referral-based clinic in a tertiary care hospital. The shoulders of 13 patients with normal renal function and of 38 patients receiving long-term hemodialysis were studied by real-time, high-resolution ultrasound. All hemodialysis patients were evaluated clinically for the presence of dialysis-related amyloidosis. Surgical specimens of joints were available for all 13 patients with normal renal function and for 17 of the 38 hemodialysis patients. These specimens were evaluated for the presence of beta 2-microglobulin (beta 2m) amyloid by Congo red and immunohistochemical staining. RESULTS: Two ultrasonographic findings were selectively observed in the dialysis patients with clinical and histologic evidence of beta 2m amyloid in comparison with patients with normal renal function and no evidence of amyloid: rotator cuffs greater than 8 mm in thickness and echogenic pads between muscle groups of the rotator cuff. The presence of at least 1 of these 2 findings corresponded to the presence of clinically and histologically evident beta 2m amyloid with a sensitivity of 79% and a specificity of 100%. When additional patients without surgical specimens for histologic confirmation of amyloidosis were included, the sensitivity of these 2 sonographic findings was 72% and the specificity was 97%. CONCLUSION: Real-time, high-resolution ultrasound is a relatively sensitive and highly specific noninvasive adjunct to the clinical diagnosis of beta 2m amyloidosis in patients receiving long-term hemodialysis.

Adult↗
PubMed1993

Labial salivary gland biopsy is a reliable test for the diagnosis of primary and secondary amyloidosis. A prospective clinical and immunohistologic study in 59 patients.

OBJECTIVE: Reports of the detection of amyloidosis by labial salivary gland (LSG) biopsy have been mostly anecdotal. The aim of this study was to assess the value of this method in the diagnosis of amyloidosis. METHODS: LSG biopsy tissues were studied with a combination method using Congo red stain and immunohistologic characterization using an antibody directed against the serum amyloid P (SAP) component. Electron microscopy was performed in all cases. In a prospective study, we evaluated 30 patients with biopsy-proven AA or AL amyloidosis. We compared these patients with a control group of 29 age-matched patients without clinical or biologic evidence of amyloid disease (14 had rheumatoid arthritis and 15 had plasma cell dyscrasia). RESULTS: In 26 of the 30 patients with known systemic amyloidosis, amyloid deposits were identified on LSG biopsy (sensitivity of 86%). In 1 of the remaining patients, amyloid deposits were identified on LSG biopsy and systemic amyloidosis was confirmed by abdominal fat biopsy and 123I-labeled SAP scintigraphy. CONCLUSION: This study emphasizes the high sensitivity of LSG biopsy in the diagnosis of amyloidosis, even in the absence of oral symptoms.

Adult↗
PubMed2004

Multifunctional peptide fibrils for biomedical materials.

The Ile-Lys-Val-Ala-Val (IKVAV) containing peptide, A208 (AASIKVAVSADR, mouse laminin alpha1 chain 2097-2108), was recently found to form amyloid-like fibrils. Fibril formation is critical for its biological activities, including promotion of cell adhesion and neurite outgrowth. In the present study, we designed multifunctional peptide fibrils using the A208 peptide and an Arg-Gly-Asp (RGD)-containing fibronectin active sequence for biomedical applications. The fibronectin active sequence GRGDS (FN) or a scrambled sequence RSGGD (SC) were conjugated to either A208 or to A208S (AASVVIAKSADR), a scrambled peptide of A208, with a glycine as a spacer. The FN-A208 and SC-A208 peptides formed a gel and were stained with Congo red similar to that of A208, but FN-A208S and SC-A208S did not form a gel. These results indicate that FN-A208 and SC-A208 form amyloid-like fibrils similar to A208. A208 and SC-A208 promoted cell attachment with filopodia formation, and this adhesion was inhibited by the IKVAV-containing peptide, but not by EDTA or a GRGDS peptide. FN-A208 promoted cell attachment with well-organized actin stress fibers, and this adhesion was partially inhibited by either EDTA, GRGDS, or IKVAV. These data suggest that A208 binds to only IKVAV receptor(s) while the FN-A208 interacts with both integrins and the IKVAV receptor(s). We conclude that multifunctional peptide fibrils can be designed by conjugation of active peptides on A208 and that this construct has potential to serve as a bioadhesive for tissue regeneration and engineering.

Amyloid↗
PubMed2005

Template-directed self-assembly and growth of insulin amyloid fibrils.

The formation of amyloid aggregates in tissue is a pathological feature of many neurodegenerative diseases and type II diabetes. Amyloid deposition, the process of amyloid growth by the association of individual soluble amyloid molecules with a pre-existing amyloid template (i.e., plaque), is known to be critical for amyloid formation in vivo. The requirement for a natural amyloid template, however, has made amyloid deposition study difficult and cumbersome. In the present work, we developed a novel, synthetic amyloid template by attaching amyloid seeds covalently onto an N-hydroxysuccinimide-activated surface, where insulin was chosen as a model amyloidogenic protein. According to ex situ atomic force microscopy observations, insulin monomers in solution were deposited onto the synthetic amyloid template to form fibrils, like hair growth. The fibril formation on the template occurred without lag time, and its rate was highly accelerated than in the solution. The fibrils were long, over 2 mum, and much thinner than those in the solution, which was caused by limited nucleation sites on the template surface and lack of lateral twisting between fibrils. According to our investigations using thioflavin T-induced fluorescence, birefringent Congo red binding, and circular dichroism, fibrils grown on the template were identified to be amyloids that formed through a conformational rearrangement of insulin monomers upon interaction with the template. The amyloid deposition rate followed saturation kinetics with respect to insulin concentration in the solution. The characteristics of amyloid deposition on the synthetic template were in agreement with previous studies performed with human amyloid plaques. It is demonstrated that the synthetic amyloid template can be used for the screening of inhibitors on amyloid deposition in vitro.

Adsorption↗
PubMed2003

Structural regulation of a peptide-conjugated graft copolymer: a simple model for amyloid formation.

The self-assembly of peptides and proteins into beta-sheet-rich high-order structures has attracted much attention as a result of the characteristic nanostructure of these assemblies and because of their association with neurodegenerative diseases. Here we report the structural and conformational properties of a peptide-conjugated graft copolymer, poly(gamma-methyl-L-glutamate) grafted polyallylamine (1) in a water-2,2,2-trifluoroethanol solution as a simple model for amyloid formation. Atomic force microscopy revealed that the globular peptide 1 self-assembles into nonbranching fibrils that are about 4 nm in height under certain conditions. These fibrils are rich in beta-sheets and, similar to authentic amyloid fibrils, bind the amyloidophilic dye Congo red. The secondary and quaternary structures of the peptide 1 can be controlled by manipulating the pH, solution composition, and salt concentration; this indicates that the three-dimensional packing arrangement of peptide chains is the key factor for such fibril formation. Furthermore, the addition of carboxylic acid-terminated poly(ethylene glycol), which interacts with both of amino groups of 1 and hydrophobic PMLG chains, was found to obviously inhibit the alpha-to-beta structural transition for non-assembled peptide 1 and to partially cause a beta-to-alpha structural transition against the 1-assembly in the beta-sheet form. These findings demonstrate that the amyloid fibril formation is not restricted to specific protein sequences but rather is a generic property of peptides. The ability to control the assembled structure of the peptide should provide useful information not only for understanding the amyloid fibril formation, but also for developing novel peptide-based material with well-defined nanostructures.

Amyloid↗
PubMed1980

Field test results using the BioPEPR cervical smear prescreening system.

BioPEPR is a cathode ray tube scanning device that has been developed for the prescreening of cervical smears. Cervical samples are collected in suspension, syringed, counted and spread across a microscope slide. Feulgen-Thionine with Congo Red is used as the staining procedure. Fields of 6 X 8 mm are scanned at 1 mu resolution, using an intermediate photographic step. Morphologic parameters of the cells are measured, as called for by a hierarchical decision strategy. Analysis speed is currently about 4 min per smear; improvements of at least a factor of four are expected. A field test of BioPEPR is being undertaken in cooperation with a local population screening program. In the study two smears are made from each woman; the first is prepared according to the Papanicolaou technique while the second is prepared and stained according to the BioPEPR methods. In addition to smears from the population screening program a number of possibly abnormal smears are obtained from several gynecological clinics. To date approximately 3500 "second" smears have been analyzed by the BioPEPR system. The results show a missed positive rate on the order of a few percent (no missed positives were more severe than a slight dysplasia), and a false alarm rate of about 24%. A further analysis of the age distribution of the false alarm rate shows that a large proportion came from women above the age of 50; the false alarm rate is about 20% for women under the age of 50.

Adult↗
PubMed1987

Carcinoma in situ specimen classification based on intermediate cell measurements.

In this study the possibility of classifying carcinoma in situ and normal specimens by measuring normal-appearing intermediate cells was explored. Twenty-five histologically verified carcinoma in situ specimens and 99 normal specimens, matched with the abnormal specimens for age and use or nonuse of an oral hormonal contraceptive, were examined. The smears were monolayer preparations stained with Thionin-Feulgen Congo red. Twenty-one nuclear features were measured. A discrimination among the experimental groups could be made on the basis of the relationship between two features, area and average optical density (AOD). A regression of AOD on area for each smear was performed. The correlation, coefficient of variation, slope, intercept, as well as the mean of the AOD level and the age of the subject were used in a discriminant analysis. This resulted in a smear classification with a false-positive rate of 14% and a missed-positive rate of 32%. When contraceptive use was taken into account the overall classification was improved with a false-positive rate of 12% and a missed-positive rate of 20%.

Adult↗
PubMed2002

Aspiration cytodiagnosis of amyloid from vitreous fluid.

Amyloidosis of the vitreous body is a rare disorder that causes progressive visual loss. In this report, a 36-yr-old female with familial amyloidosis is described in whom a progressive reduction of vision in both eyes over the last 4 yr was ascribed to vitreous opacities due to amyloid. A left pars plana vitrectomy was performed and an aspirated sample of the vitreous on cytologic examination showed vitreous strands admixed with abundant dense, pink, globular material which was intensely positive on Congo red staining and exhibited yellowish-green birefringence indicative of amyloid. This was further confirmed ultrastructurally, which showed the classical appearance of amyloid fibrils. The case is of interest not only in view of the rarity of the condition but also in view of the fact that as far as we are aware the cytodiagnosis of amyloid from an aspirate sample from the vitreous has not been previously described in the literature.

Adult↗
PubMed2003

Amyloid tumor: a clinical and cytomorphologic study.

We describe the cytologic findings and clinical presentation of three unusual cases of amyloid tumor. Two of our patients had low-grade lymphoid malignancies and the third insulin-dependent diabetes mellitus. In no cases was amyloid suspected as the cause of mass lesion. Two of our cases presented with superficial soft tissue mass and the third with right breast masses and bilateral axillary lymph node enlargement. Air-dried slides from all aspirated cases were stained with Diff-Quik for specimen adequacy evaluation. The remaining fixed slides were stained with Papanicolaou stain. Amyloid appeared as dark-blue to purple clumps of acellular material on Diff-Quik stain, accompanied with chronic inflammatory cell infiltrates and multinucleated giant cells, simulating granulomatous inflammation. Papanicolaou stain demonstrated cyanophilic to orangophilic acellular material. Amyloid was suspected and subsequently confirmed by Congo red stain.

Aged↗
PubMed2004

Unsuspected systemic amyloidosis diagnosed by fine-needle aspiration of the salivary gland: case report.

Amyloidosis of the head and neck region may represent a local amyloidoma or a manifestation of systemic disease. Involvement of major salivary glands by either primary or secondary forms of amyloidosis is very rare. We describe a case of systemic amyloidosis that initially presented as submandibular gland mass and was diagnosed by fine-needle aspiration (FNA). A 69-year-old male presented with submandibular mass. His past medical history was significant for left forearm melanoma that was excised 6 years ago and tricuspid valve endocarditis after valvular replacement 3 months prior to FNA of the submandibular gland. The patient had no symptoms or clinical and laboratory data suggestive of amyloidosis. FNA specimen showed salivary gland tissue and abundant amorphous material, which stained positive for amyloid with Congo red stain and showed typical birefringence when examined by polarized microscopy. Further workup of the patient revealed generalized amyloidosis with multiorgan involvement by the disease. This case demonstrates that FNA can be a useful technique in the diagnosis of unsuspected amyloidosis.

Aged↗
PubMed1993

Nodular pulmonary amyloidosis: diagnosis by fine-needle aspiration cytology and a review of the literature.

Solitary nodular pulmonary amyloid tumor is an uncommon benign lesion which is seldom diagnosed prior to surgical extirpation. We present a case of unsuspected nodular pulmonary amyloid tumor diagnosed by fine needle aspiration cytology. A 52-yr-old-black woman, presented with a 3-cm right middle lobe mass. Percutaneous fine-needle aspiration cytology (FNA) of the mass revealed waxy amorphous material that demonstrated apple green birefringence on Congo Red Stain. Thoracotomy for diagnosis may be avoided by using FNA to diagnose these unusual lesions.

Amyloidosis↗
PubMed1994

Potassium permanganate resistant amyloid in fine-needle aspirate of the liver.

A case of primary amyloidosis, initially detected by fine-needle aspiration of the liver, is reported here. Amorphous acellular metachromatic material was seen extracellularly in between the hepatocytic cords compressing them. This material showed typical apple-green birefringence under crossed bipolars after alkaline Congo-red staining proved its amyloid nature. It was resistant to potassium permanganate pretreatment, indicating it to be of the AL type.

Amyloid↗