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Biomedical subjects

P Westermark

Publications and source records attributed to P Westermark.

At least 199 records · Page 11Linked to original sources
PubMed1978

The influence of amyloid deposits on the islet volume in maturity onset diabetes mellitus.

Pancreatic islet volumes of patients with and without maturity onset diabetes mellitus were estimated. The islet volume of the diabetic patients was 1.01 +/- 0.12 cm3 (SEM) and that of the non-diabetic patients 1.60 +/- 0.16 cm3 with considerable overlap between the two groups. Islet amyloidosis was found in all the diabetic and in 9 of the 15 non-diabetic patients. When the amyloid deposits were excluded, the islet volume of the diabetic patients was 0.89 +/- 0.10 cm3, while that of the non-diabetic patients was unchanged, 1.60 +/- 0.16 cm3. There was still some overlapping. Since amyloid deposits seem to destroy the B cell membranes, it was postulated that a comparison of the volumes of islets completely free of amyloid might give a more true picture of the quantitative islet alterations in maturity onset diabetes. It was found that this islet volume of the diabetics was only 0.41 +/- 0.05 cm3 and that of the non-diabetic patients 1.58 +/- 0.16 cm3. These values correspond better to the altered insulin secretion in maturity-onset diabetes mellitus.

Aged↗
PubMed1978

Senile cardiac amyloid: demonstration of a unique fibril protein in tissue sections.

Antisera were raised against degrading amyloid fibrils isolated from the heart of a patient with senile cardiac amyloidosis (SCA), and from a medullary carcinoma of the thyroid (MCT). The antisera were absorbed and used in indirect immunofluorescence to identify an amyloid fibril protein (ASCA) in heart tissue from patients with senile cardiac amyloidosis and to identify the amyloid fibril protein (AMCT) found in association with medullary carcinomas of the thyroid. Absorbed anti-ASCA antiserum did not react with normal tissue such as heart, liver, spleen, and striated muscle, or with amyloid tissue known to contain amyloid fibril proteins AA, AlambdaI, AlambdaIV, AlambdaV, AMCT or with pancreatic tissue containing islet amyloid deposits. The reactions with senile amyloid he,rt tissue could be blocked completely by degraded amyloid fibrils extracted from senile amyloid heart tissue or by amyloid fibril protein ASCA isolated from such fibrils. The anti-AMCT antiserum showed a similar specific reaction restricted to amyloid associated with MCT. In addition, antisera specific for amyloid fibril proteins AA, AlambdaI, AlambdaIV, and AlambdaV failed to react with senile cardiac amyloid, pancreatic islet amyloid, or medullary thyroid amyloid.

Aged↗
PubMed1977

Characterization of an amyloid fibril protein from senile cardiac amyloid.

A protein, ASCA, is isolated from amyloid fibrils extracted from heart tissue of five different patients with senile cardiac amyloidosis (SCA). The proteins of all five patients showed immunological identity when reacted with an antiserum raised against one of the proteins. In contrast, no reaction was obtained with antisera against a variety of other amyloid proteins. The antiserum against the subunit protein of senile cardiac amyloid did not react with any other amyloid preparations tested, nor with extracts of normal heart tissue. Thus, the subunit protein appeared to be unique to senile heart amyloid. The protein could form fibrils in vitro, had a mol wt of about 6,000 daltons and the amino acid compositions investigated in two cases showed extensive similarities but were clearly different from that of protein AA of secondary amyloid fibrils.

Aged↗
PubMed1977

Amyloid of human islets of Langerhans. II. Electron microscopic analysis of isolated amyloid.

Isolated amyloid from the islets of Langerhans of patients with maturity onset diabetes mellitus was compared with amyloid fibrils from patients with different types of systemic amyloidosis. It was found that systemic amyloids had in common rigid and non-branching filaments with a width of about 75 A and that these filaments sometimes were attached laterally, forming thicker fibrils. Similar filaments could also be extracted from islet amyloid but the main part of this amyloid was built up by large aggregates of very thin and often very wavy units. This structure, which has not been previously described in human amyloid, probably explains some properties of isolated islet amyloid.

Amyloid↗
PubMed1977

Identification and characterization of different amyloid fibril proteins in tissue sections.

Antisera specific for 4 different classes of amyloid fibril proteins, amyloid protein AA and the immunoglobulin light-chain amyloid proteins AlambdaI, AlambdaIV, and AlambdaV, were used to identify these proteins directly in tissue sections from 25 patients with amyloidosis. The specificity of these reactions was established by blocking experiments with purified amyloid fibril proteins and Bence Jones proteins of known variable subgroups. Protein AA was detected in 17 patients, including all 13 with secondary amyloidosis, 2 with primary amyloidosis and 2 with Waldenström's macroglobulinemia. Immunoglobulin light-chain proteins AlambdaI, AlambdaIV, and AlambdaV were in 3, 1, and 2 patients, respectively, all of whom had primary or myeloma/macroglobulinemia-associated amyloidosis. Antiserum specific for the amyloid-related serum protein SAA reacted with the same tissues as anti-AA and had the same pattern of staining in tissue sections.

Amyloid↗
PubMed1977

Amyloidosis in ageing obese-hyperglycemic mice and their lean litter-mates. A morphological study.

The occurrence of amyloidosis in obese-hyperglycemic mice (genotype obob) about 18 months old and their lean litter-mates was studied. Amyloidosis of varying degrees was found in 60 per cent of the mice and was equally common in both groups. Large amounts of amyloid were usually seen in the adrenal glands, liver, spleen and kidneys. In the kidneys, the amyloid was found mainly in the glomeruli, in the mesangial region. Electron microscopy of isolated amyloid fibrils showed that these consisted of two filaments about 40 A thick, twisted around each other. It is concluded that the distribution of the amyloidosis in these mice is similar to that seen in secondary or experimental murine amyloidosis.

Adrenal Glands↗
PubMed1977

Argentaffin and argyrophil reactions of human gastrointestinal carcinoids.

Forty-five carcinoids from the gastrointestinal tract, classified on morphological grounds, were stained with an argentaffin technique (Masson-Hamperl, Virchows Arch [Pathol Anat] 266:509-548, 1927) and three argyrophil techniques (Grimelius, Acta Soc Med Upsal 73:243-276, 1968; Sevier-Munger, J Neuropathol Exp Neurol 24: 130-135, 1965; and Hellerström-Hellman, Acta Endocrinol (Kbh) 35:518-532, 1960). Most but not all carcinoids from the embryonal midgut were argentaffin, whereas most fore- and hindgut carcinoids were nonargentaffin. The argyrophil stain of Sevier-Munger stained all argentaffin tumors and in addition a few nonargentaffin foregut carcinoids. The Grimelius stain stained all and the Hellerström-Hellman stained none of the tumors, irrespective of their location. In the argentaffin carcinoids the frequency of argyrophil cells exceeded that of argentaffin cells.

Amyloid↗
PubMed1977

Amyloid in polypeptide hormone-producing tumors.

The hormone content of 72 endocrine tumors was determined by immunofluorescence and their amyloid content was investigated. Seventeen of the 72 tumors contained amyloid. Amyloid was frequently found in tumors producing calcitonin, insulin, or growth hormone, but was rarely found in other tumors. Thus, there is a relationship between the occurrence of amyloid in an endocrine tumor and the type of hormone it produces. The reason for this is not known, but there is evidence that the amyloid fibrils contain proteins related to the hormone produced by the tumors.

Adenoma↗
PubMed1976

On argyrophil reactions of endocrine cells in the human fetal pancreas: a light and electron microscopic study.

The endocrine cells in the pancreas of five human fetuses with gestational ages of 18-20 weeks were examined by light and electron microscopy with special regard to argyrophil reactions. B-cells and typical A- and D-cells were easily identified electron microscopically on the basis of their typical secretory granules. In the Grimelius argyrophil silver stain, a concentration of silver grains over the less electron dense peripheral mantle of the A-cell secretory granules was observed by electron microscopy. In the Hellerström and Hellman modification of the argyrophil Davenport alcoholic silver stain, silver grains were concentrated over the internal structures of the D-cell secretory granules. With this stain an accumulation of silver grains was also seen at the surface of the A-cell secretory granules. The argyrophil reaction of the A-granules was less pronounced than in the D-cells. In addition to B-cells and A- and D-cells, two other types of endocrine cell were observed by electron microscopy. These cells were argyrophil with the silver impregnation method of Grimelius. The electron microscopic findings at least partly explain the frequent overlapping between the two staining methods observed at the light microscope level.

Cytoplasmic Granules↗
PubMed1976

Characterization of amyloid fibril proteins from medullary carcinoma of the thyroid.

Amyloid fibrils were studied from two different tissues of medullary carcinoma of the thyroid (MCT). The fibrils mainly consisted of a low molecular weight protein, AMCT, which was immunologically distinct and did not react with various antisera against known amyloid fibril proteins. A specific antiserum raised against the MCT amyloid proteins gave a reaction of identity with the degraded MCT amyloid fibrils from two patients, as well as with the isolated AMCT protein, but showed no reaction with other known amyloid proteins. The AMCT protein had a blocked N terminus, but the sequence analysis of a cyanogen bromide fragment revealed identity with human calcitonin in the 11 positions studied. Although the amino acid composition was similar, there were also distinct differences, and the mol wt of 5,700 daltons was considerably larger than that of calcitonin. For these reasons the AMCT protein may represent a prohormone of calcitonin.

Amino Acids↗
PubMed1976

Coexistence of protein AA and immunoglobulin light-chain fragments in amyloid fibrils.

Coexistence of amyloid fibril protein AA and homogeneous immunoglobulin light-chain fragments was found in the isolated amyloid fibrils of two patients with amyloidosis secondary to rheumatoid arthritis. The light-chain amyloid fibril protein showed antigenic identity with a light-chain amyloid from a patient with primary amyloidosis, which was identified as the VlambdaIV subgroup by amino acid sequence analysis. In the amyloid fibrils isolated from another patient with primary amyloidosis there was a mixture of VlambdaIV and VlambdaV homogeneous immunoglobulin light chains. Thus, a mixture of protein AA had lambda light chains or two different types of homogeneous light chains may be found in the amyloid fibrils of some patients.

Amino Acid Sequence↗
PubMed1975

The P-component of amyloid of human islets of langerhans.

The P-component of amyloid was found in extracts of pancreases with islet amyloidosis. In double immunodiffusion this P-component showed lines of identity with isolated purified human P-component, normal human serum, and an extract of amyloid-rich liver tissue from a patient with primary systemic amyloidosis. The finding supports the theory that the P-component is present in all native human amyloid irrespective of type.

Adolescent↗
PubMed1975

Amyloid of medullary carcinoma of the thyroid; partial characterization.

Amyloid was isolated from lymph node metastases of a medullary thyroid carcinoma. SDS electrophoresis and gel filtration revealed a major subunit protein of MW less than 10 000. This subunit was capable of forming fibrils when dialysed in a solution against water. The amino acid composition of the subunit differed unequivocally from that of calcitonin. The amyloid also differed from systemic amyloids, since it did not form a top layer when homogenized and, further, did not seem to contain significant amounts of tryptophane. Since the amyloid of medullary carcinoma of the thyroid showed definite similarities to islet amyloid it is concluded that these two amyloids form a special class.

Adult↗