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Biomedical subjects

J Hed

Publications and source records attributed to J Hed.

100 records · Page 6Linked to original sources
PubMed1980

Detection of immune deposits in glomeruli: a comparative study of paraffin-embedded, enzyme-treated sections and cryostat sections as substrates in immunofluorescence.

Paraffin-embedded tissue can be used as substrate for immunohistochemistry after enzymatic treatment with proteases. The sensitivity of immunofluorescence on enzyme-treated paraffin sections and on unfixed cryostat sections is compared in this study. Pepsin was more efficient by weight than trypsin in restoring the antigenicity of immune deposits. Increased fluorescence intensity was obtained up to a pepsin concentration of 0.4%. Intensity was further increased when pepsin treated sections were treated with trypsin. Immune deposits were detected in enzyme treated, paraffin sections of kidneys of mice injected with anti-GBM diluted 1/200 or less and in cryostat sections of mice injected with anti-GBM diluted 1/400 or less. This small decrease in sensitivity is considered trivial compared with the advantage gained by the excellent preservation of the tissue.

Animals↗
PubMed1980

Detection of immune deposits in glomeruli. Light-, fluorescence- and electron microscopic investigation of consecutive sections.

Methods which permit a close comparative light-, fluorescence- and electron microscopical investigation of kidney tissue are lacking. In this study is described a technique for handling of formalin sections, 40 micrometer-160 micrometer thick in preparatory steps which include proteolytic treatment for "unmasking" of immune deposits and which end in Epon embedded, consecutive semithin and ultrathin sections. These are shown to be able to use for detailed immuno-morphological comparison.

Animals↗
PubMed1980

Renal pathology of Waldenström's macroglobulinaemia with monoclonal antiglomerular antibodies and nephrotic syndrome.

Severe nephrotic syndrome developed suddenly in a 67-year-old man. IgM M-component and bone marrow findings indicated a diagnosis of Waldenström's macroglobulinaemia. High-titre IgM glomerular autoantibodies were found to reside mainly in the M-component. Immunofluorescent (IF) studies on serial kidney biopsies showed extensive IgM deposits that disappeared after treatment. Light microscopy of kidney biopsy appeared only slightly altered, but combined with electron microscopy could demonstrate changes that correlated well with IF findings. The latest biopsy showed interstitial infiltration in the kidney of atypical lympho-histiocytic cells. Morphological and immunological examination indicated that pathogenetic events started with minimal-change glomerulonephritis, causing release of glomerular antigen, that finally triggered a monoclonal IgM response and lymphoproliferative reaction. Intermittent treatment with chlorambucil and corticoids completely abolished the nephrotic syndrome and at the same time the changes in renal morphology largely disappeared.

Aged↗
PubMed1979

Procainamide-induced lupus erythematosus-like syndrome in relation to acetylator phenotype and plasma levels of procainamide.

To investigate the relationship between acetylator phenotype and the development of procainamide (PA)-induced systemic lupus erythematosus (SLE-like syndrome, 28 patients with chronic ventricular arrhythmias treated with PA were followed for one year. The therapy was guided by plasma monitoring in all patients in order to obtain the proposed therapeutic plasma level of PA. Nine patients (30%), both slow and rapid acetylators, developed the SLE-like syndrome within one year. PA plasma levels were similar in both slow and rapid acetylators and there was no difference in total dose or duration of therapy before development of the syndrome. Thus, the acetylator phenotype is probably of no or minor predictive importance when PA therapy is guided by plasma monitoring. On the other hand, the antinuclear antibodies appeared significantly more rapidly in patients developing the syndrome and could possible be used as an indicator of the risk. The results support the hypothesis that the primary amino group structure of PA may be of importance in the induction of the SLE-like syndrome.

Acecainide↗
PubMed1979

Characteristics of individual polymorphonuclear leucocyte motility obtained with a new opto-electronic method.

An opto-electronic device has been used for a quantitative assessment of the motility of individual polymorphonuclear leucocytes (PMNL) adhering to a glass cover slip. One of the oculars in a phase contrast microscope is provided with a mini-array of 32 x 32 light-sensitive elements. These are connected to an electronic unit, capable of recording the number of light-intensity changes on each element and of visualizing the path of a cell on an oscilloscope screen, as a pattern of dots. The results clearly show that individual PMNL respond differently to environmental conditions; for instance, (i) raising the temperature increased the motility of cells to a maximum at around 39 degrees C and lowering the temperature from 42 degrees C restored their peak motility, (ii) protein was required at attachment depending on the temperature at attachment, (iii) endotoxin-activated normal human serum affected more drastically cells with a low initial motility and cytochalasin B more adversely influenced cells with a high initial motility, (iv) phagocytosis of yeast cells reduced the percentage of motile cells, which was more pronounced if the PMNL were washed before the motility measurement. The average motility of the PMNL was also diminished, although individual PMNL retained normal activity after ingestion of one or more yeast cells.

Animals↗
PubMedDate not supplied

Ca2+-dependent and Ca2+-independent phagocytosis in human neutrophils.

The phagocytic function of neutrophils is a crucial element in host defence against invading microorganisms. Two main specific receptor-mediated mechanisms operate in the phagocyte plasma membrane, one recognizing the C3b/bi fragment of complement and the other the Fc domain of immunoglobulin G (ref. 1). There is evidence that phagocytosis mediated by these receptors differs in the number and nature of the intracellular signals generated. However, the mechanisms by which receptor binding is transduced into a signal that generates the formation of the phagocyte pseudopod is not known, although extensive biochemical evidence has allowed the postulate that calcium ion gradients in the peripheral cytoplasm, by interacting with calcium-sensitive contractile proteins, initiate the process of engulfment. Using the high-affinity fluorescent calcium indicator quin2 both to measure and to buffer intracellular calcium ([Ca2+]i), we show here that in human neutrophils two mechanisms of phagocytosis coexist: a [Ca2+]i-dependent and modulated phagocytosis, triggered by activation of the Fc receptor, and a [Ca2+]i-independent mechanism triggered by the activation of the C3b/bl receptors.

Aminoquinolines↗
PubMedDate not supplied

CR1-expression and C3b-mediated phagocytosis of granulocytes in purulent maxillary secretion and peripheral blood from patients with sinusitis.

Granulocytes in sinus pus and in peripheral blood in 28 patients with maxillary sinus empyema were compared to blood granulocytes obtained from healthy blood donors. A flow cytofluorometric assay technique was used to establish the C3b-mediated phagocytosis and the CR1-receptor expression. The results indicate that a subpopulation of viable granulocytes in situ was activated with an increased ability to ingest particles. From 11 of 28 patients, an increased CR1-expression was also demonstrated in the blood samples, reflecting a priming of the circulating granulocytes before extravasation.

Adult↗