Search PubMed⌕ Search

Biomedical subjects

M D Benson

Publications and source records attributed to M D Benson.

At least 199 records · Page 11Linked to original sources
PubMed1980

Diffuse fasciitis and eosinophilia with symmetric polyarthritis.

Articular involvement has been infrequently reported in diffuse fasciitis with eosinophilia. We report a patient with diffuse fasciitis with eosinophilia, concurrent symmetrical polyarthritis, and bilateral carpal tunnel syndrome. Light microscopy and immunofluorescence studies of synovium and full-thickness calf biopsy were done. Synovial fluid analyses showed mildly inflammatory fluid. Response to prednisone, clinically and by laboratory indicators, was prompt and dramatic.

Adult↗
PubMed1979

Serum amyloid A protein in amyloidosis, rheumatic, and enoplastic diseases.

Serum levels of amyloid protein A (SAA) have been shown to be elevated in different types of amyloidosis and in rheumatic diseases by radioimmunoassay using 125 iodine labeled AA and anti-AA. SAA levels were elevated in both primary and secondary amyloidosis, but there were highly significant differences between these levels. In heredofamilial amyloid, SAA levels were within normal limits. While the mean SAA level was elevated in persons over 70 years, the fact that some persons in this age group had normal levels suggested that marked elevation after age 70 may be due to occult inflammatory or neoplastic disease. High SAA levels in patients with rheumatoid arthritis correlated, in most cases, with physician evaluation of disease activity and Westergren ESR. SAA levels in patients with systemic lupus erythematosus were lower than those in patients with rheumatoid arthritis, and most patients with degenerative joint disease had normal levels. Very high levels of SAA were found in patients with neoplastic diseases. Patients with carcinoma of the lung and bowel had much higher levels than patients with carcinoma of the breast. Determination of SAA levels may be of value in evaluating different forms of systemic amyloidosis, assessing the activity of rheumatic disease, and screening for occult inflammatory or neoplastic disease.

Aged↗
PubMed1979

The effect of a liver protein synthesis inhibitor on plasma SAA levels in a model of accelerated amyloid deposition.

Animals treated with AgNO3 and amyloid-enhancing factor deposit large quantities of splenic amyloid in 48 hours. The kinetics of SAA production was examined in such a model in the presence and absence of an inhibitor of liver protein synthesis (ethionine). Ethionine had little effect on splenic protein synthesis but inhibited both the production of SAA and liver protein synthesis. When experiments were performed with fed mice, ethionine induced an inhibition of liver protein synthesis lasting 16 hours. Thereafter, liver protein synthesis began to recover, accompanied by a rise in plasma SAA levels. These results are consistent with hepatic but not splenic synthesis of SAA.

Amyloid↗
PubMed1979

Serum amyloid P-component levels in amyloidosis, connective tissue diseases, infection, and malignancy as compared to normal serum.

A highly sensitive radioimmunoassay was developed to measure the serum levels of SAP. Sera from 50 normal individuals ranging in age from 4 to 89 years had a mean level of 7.47 mg/dl and showed no variations with age. Sera from persons with various clinical types of amyloidosis, connective tissue diseases, and bacterial pneumonia did not differ significantly from normal values. A significant difference was noted in the sera from persons with malignancy, where a mean value of 10.79 mg/dl was determined. Although a number of similarities exist between SAP and CRP, SAP does not share the property of being an acute-phase reactant.

Adolescent↗
PubMed1979

Serum amyloid protein SAA, C-reactive protein and lysozyme in leprosy.

Serum amyloid protein (SAA) appears to be the precursor of amyloid protein AA, the non-immunoglobulin fibril protein of secondary amyloidosis. Since amyloidosis is known to occur in high frequency associated with lepromatous leprosy (LL), we have examined the SAA levels in untreated LL patients and compared them to the levels observed in patients with tuberculoid leprosy (TT) and a large number observed in healthy controls. We found that SAA is markedly elevated in LL when compared to TT and controls. No clear correlation could be established with C-reactive protein, a well-documented acute phase reactant, or serum lysozyme levels that reflect the presence of monocyte activity. This study showed that SAA levels in leprosy do not appear to be a reflection of inflammatory activity or monocyte turnover. Whether amyloidosis will be more prevalent in patients who have higher SAA levels remains to be determined.

Amyloid↗
PubMed1978

Amino terminal sequence of amyloid P-component isolated from serum.

Amyloid AP (protein SAP) has been isolated from human serum by affinity chromatography using specific antiserum and shown to have the same immunologic and ultrastructural characteristics as the pentagonal protein isolated from amyloid tissue (AP). Polyacrylamide gel electrophoresis in SDS reveals a single subunit of 25,000 daltons for both SAP and AP preparations. N-terminal amino acid sequence of this alpha globulin to 13 residues reveals complete homology with the tissue-extracted protein, suggesting that AP is incorporated into, or adsorbed onto, amyloid fibrils without biochemical alteration.

Amino Acid Sequence↗
PubMed1977

Fractionation of primary amyloid fibrils. Characterization and chemical interaction of the subunits.

Amyloid fibrils of kappa origin from a patient with primary amyloidosis are dissociated in various denaturants and fractionated into their subunit components on Sepharose 6B. Solubilization of the fibrils in 4 M guanidine-HCl followed by reduction and alkylation produced 22 000 and 17 000 dalton fractions. Without prior reduction and alkylation, these fractions exist as a high molecular weight protein which can be separated on Sepharose 6B. A high molecular weight protein can be directly dissociated from the amyloid fibril with 1% sodium dodecyl sulfate or 1 M NaCl. Reduction and alkylation of this material produces the two lower molecular weight fractions, i.e., 22 000 and 17 000. These have in the first 20 residues identical N-terminal amino acid sequences; they share immunologic identity and have similar tryptic peptide map profiles. Amino acid analysis of the 22 000 dalton fraction is identical with the intact immunoglobulin light chain isolated from the patient's serum. These data suggest that the insoluble amyloid fibril is the result of aggregation by disulfide linkages between the 22 000 and 17 000 dalton fractions.

Amino Acid Sequence↗
PubMed1977

Kinetics of serum amyloid protein A in casein-induced murine amyloidosis.

Serum amyloid protein A (SAA), the precursor of secondary amyloid protein, is elevated in chronic diseases which are associated with an increased incidence of amyloid. However, SAA is also elevated in acute bacterial and viral infections and somes forms of cancer. The murine model of casein-induced amyloidosis was studied to determine the relationship between SAA production and amyloid deposition. SAA levels measured by radioimmunoassay were found to be as high as 200 times the normal level in CBA/J mice receiving daily parenteral casein. After a single injection of casein the SAA level was elevated by 3h and peaked by 12-18 h. Similar levels were found in casein-treated A/J mice, a strain less susceptible to the induction of amyloid. Parenterally administered bovine serum albumin, which has low potential for amyloid induction, gave SAA levels in CBA/J and A/J mice comparable to casein treatment. These data show that, while SAA levels are elevated during chronic antigenic stimulation, there are other factors involved in amyloid formation. These factors may include alterations in the degradation of SAA by the reticuloendothelial system caused by substances such as casein. Nude (athymic) mice were shown to attain high levels of SAA after receiving casein parenterally. Therefore, thymus-derived lymphocytes are not necessary for the synthesis of SAA.

Amyloid↗
PubMed1977

Generalized amyloid in a family of Swedish origin. A study of 426 family members in seven generations of a new kinship with neuropathy, nephropathy, and central nervous system involvement.

We report a new kinship with systemic amyloid presenting as peripheral neuropathy in the fourth and fifth decades of life. A progressive sensory and motor loss starting in the lower extremities occurs from this disease, and there is subsequent renal, cardiac, gastrointestinal, ocular, and cutaneous involvement. Histologic studies show that amyloid deposition is mainly in connective tissue structures; there is an unusual infiltration of the meninges and central nervous system. Review of records of 426 family members in seven generations showed that this disease is inherited as an autosomal dominant. The absence of immunoglobulin disorders in two affected family members studied in depth suggests that this is not the primary type of amyloid in which the deposits are composed of fragments of immunoglobulin light chains. Similarly the absence of elevated levels of protein SAA (the serum precursor of secondary amyloid) suggests that this is not a secondary form of amyloid.

Adult↗
PubMed1977

Amyloid deposition in a renal transplant in familial Mediterranean fever.

A patient with familial Mediterranean fever and amyloidosis who received a cadaver renal transplant 6 1/2 years ago was studied to determine the relation of the serum precursor of secondary amyloid (SAA) to the clinical course and to the deposition of amyloid in the transplant. Amyloid fibrils extracted from the patient's kidneys contained protein AA as a major constituent, which identified the amyloid as secondary. Protein AA antiserum was used in an indirect immunofluorescent technique to stain amyloid deposits in sections of the original kidney. A renal biopsy at 2 years showed no amyloid, but a renal biopsy at 4 years showed amyloid. Serum levels of SAA from 3 years before transplant to 6 years after transplant were elevated throughout most of the course.

Adult↗
PubMed1977

Murine amyloid protein AA in casein-induced experimental amyloidosis.

Amyloidosis was induced in mice by 25 subcutaneous injections of casein. The splenic amyloid fibrils were identified by electron microscopy to be closely associated with reticular cells. After isolation of the fibrils by simple physical techniques, their ultrastructure revealed single filaments of 80 to 100 A width, which were rigid, nonbranching, and of indeterminate length. This is comparable to previous studies on human preparations. The amyloid fibrils were dissociated by solution in guanidine and chromatography. The resultant amyloid fibril protein was characterized as to its molecular weight, amino acid analysis, and amino-terminal sequence. It was thus definitely identified as protein AA, the major component of secondary amyloidosis. An antibody to this protein, murine AA, identified a cross-reacting mouse serum protein SAA and indicated a species specificity when tested against human preparations. A comparison is made with the AA protein in another murine model as well as AA proteins from human, guinea pig, monkey, and mink amyloidosis.

Amino Acid Sequence↗
PubMed1975

Suppression of in vitro antibody response by a serum factor (SAA) in experimentally induced amyloidosis.

Serum from CBA/J mice made amyloidotic by chronic casein injections has been shown to suppress in vitro antibody response to SRBC. Similar suppression was also found with normal mouse serum but to a much lesser degree. This suppressive activity of both amyloidotic serum and normal serum was removed by absorption of the sera with antiserum to protein AA, the major constituent of casein-induced (secondary) amyloid fibrils. This antiserum to the amyloid fibril protein AA (mol wt 8,400 daltons) detects an immunologically cross-reacting serum alpha globulin (SAA) (mol wt approx. 100,000). It is postulated that the serum factor (SAA) is a regulator of antibody response and may be present in elevated amounts as the result of chronic antigenic stimulation.

Alpha-Globulins↗
PubMed1975

Neuropathy, M components, and amyloid.

Of eighty-seven patients with nonhereditary systemic amyloidosis, ten had evidence of peripheral neuropathy. There was median-nerve neuropathy due to infiltration of the flexor retinaculum with amyloid in six patients. Two patients had diffuse sensorimotor neuropathy and two patients had sensory loss without evidence of motor impairment--three of these cases had amyloid deposition demonstrated by nerve biopsy. Neurological manifestations in all ten patients preceded other evidence of amyloidosis by 6 months-4 years (mean, 1 to 5 years). Neuropathy occurred in six of thirty-eight patients with primary amyloidosis and four of fourteen with amyloidosis associated with malignant B-cell dyscraias; and all patients with neuropathy had either a serum-M-component or Bence-Jones proteinuria. In contrast, neuropathy was not noted in any of the fifty-six patients in this series who had no evidence of a monoclonal gammopathy (thirty-five with secondary and twenty-one with primary amyloidosis).

Amyloidosis↗