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Biomedical subjects

J L Duffy

Publications and source records attributed to J L Duffy.

At least 19 recordsLinked to original sources
PubMed1983

Fibrillary renal deposits and nephritis.

Fibrillary renal deposits and nephritis. The authors have studied 8 patients whose glomeruli contain abundant fibrils in their mesangial matrix and basement membranes. Although the location of these fibrils is very similar to that of amyloid, they are about twice the size of amyloid fibrils, averaging 20 nm in width, and fail to react as amyloid does with special stains. Immunofluorescence-microscopic studies are usually positive with antiserums to IgG, often IgM, and in some cases IgA, and also kappa and lambda light chains, C3, and C4. The fibrils are associated with diffuse mesangial widening and increased mesangial matrix strands. Although peripheral glomerular capillary walls appear to be spared initially, their eventual involvement leads to glomerular capillary collapse and glomerular obsolescence. Crescent formation occurred in 5 cases, focally in 3 and diffusely in 2. Tubular basement membrane involvement was seen in 1 case. These patients exhibit hematuria, and proteinuria, and often hypertension and renal insufficiency. Proteinuria was in the nephrotic range in 3 patients in whom involvement of glomerular capillary basement membranes was extensive. Unless electron microscopy is applied to renal biopsies, these cases may be considered to represent mesangiocapillary or rapidly progressive glomerulonephritis, or amyloidosis. The nature of these fibrils is as yet not determined. It is likely that they have been called "atypical amyloidosis" in the past.

Adult↗
PubMed1979

Identification of dense deposit disease: a report for the International Study of Kidney Diseases in Children.

The fluorescent dye thioflavin T stains intensely the deposits in dense deposit disease and can be used for identification purposes. Comparison of thioflavin T staining with electron microscopy was carried out in 25 patients and showed excellent congruity. Thioflavin T is much easier to use, but is less specific than electron microscopy. Cases of light chain disease and of some gammopathies can be a source of confusion. In nearly all other instances, the pattern of staining helps to differentiate dense deposits from other types of deposits and from amyloid.

Basement Membrane↗
PubMed1976

Ultrastructural alterations in livers with metastasis.

The electron microscopic examination of 13 biopsy specimens of livers that contained metastatic carcinoma revealed degenerative alterations of the mitochondria, cystic dilatation of the endoplasmic reticulum, increased amounts of osmiophilic material, some in various stages of autophagocytosis, and lipid vacuoles within the hepatocytes. In ten of 13 cases, the hepatocytes demonstrated mitochondrial paracrystalline inclusions. The observation of the latter structures in edematous hepatocytes containing phospholipid-rich osmiophilic deposits tends to confirm the experimental hypothesis that paracrystalline inclusions are caused by the precipitation of unmasked phospholipids. The spectrum of ultrastructural findings suggests hypoxia and impaired lipid metabolism of the hepatic tissue as a result of congestion and bile stasis caused by the tumor nodules.

Carcinoma↗
PubMed1976

Mesangial involvement in hemolytic-uremic syndrome. A light and electron microscopic study.

Electron microscopic analysis of the mesangial injury in the hemolytic-uremic syndrome was performed in 10 patients. Proteinaceous material similar to that found in the subendothelial region was also seen focally in the mesangium altering the matrix and imparting a reticular appearance. This degenerative process was associated with reparative changes in the glomerular tuft. Many of the mesangial cells were hypertrophied and demonstrated phagocytic activity and peripheral extension of their cytoplasmic processes. Mitotic figures in endothelial as well as mesangial cells were regarded as evidence of a reparative process. Severe mesangial insudation of material containing fibrinogen derivatives resulted in segmental tuft necrosis with almost complete replacement and destruction of the mesangial matrix. On some occasions, a break of the glomerular basement membrane was accompanied by the escape of intraluminal contents into the urinary space, leading to crescentic epithelial cell proliferation.

Adolescent↗
PubMed1975

Microcirculation in diabetes mellitus: a study of gingival biopsies.

Gingival biopsy specimens from 24 diabetic patients, six obese persons, and six controls were studied statistically and morphologically to detect vascular basement membrane changes using a proposed classification of microvessels. Statistically significant basement membrane thickening is seen in all diabetic groups in most true capillaries and vessels proximal to them, especially in terminal arterioles and metarterioles, although the degree and extent of the changes vary among different clinical groups and vessel types. The basement membrane thickening is characterized by increased amorphous, granular, and fibrillary material with occasional scattered collagenous fibrils. Although nonspecific, basement membrane thickening in microvessels at, and especially proximal to, the level of true capillaries is intimately related to diabetes. Gingival biopsy may possibly be used as an adjunct in the diagnosis of diabetes.

Adult↗