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Biomedical subjects

W Slidders

Publications and source records attributed to W Slidders.

9 recordsLinked to original sources
PubMed1989

Tissue fixation with phenol-formaldehyde for routine histopathology.

The addition of 2% phenol had a marked accelerating effect on neutral buffered 4% formaldehyde as a fixative. Histopathological material fixed in buffered phenol-formaldehyde (pH 7.0) and rapidly advanced to paraffin in an enclosed tissue-processor showed improved nuclear and cytoplasmic detail, reduced shrinkage and distortion, and an absence of formalin pigment. Good results were obtained in less time when sequential fixation in phenol-formaldehyde buffered to pH 7.0 and pH 5.5 was carried out at an elevated temperature (40 degrees C) in the enclosed tissue-processor. Standard histological stains and immunoperoxidase methods worked well. In resin-embedded tissue, buffered phenol-formaldehyde (pH 7.0) gave satisfactory ultrastructural results. The penetration rate of buffered phenol-formaldehyde (pH 7.0) in gelatin models did not differ from that of neutral buffered 4% formaldehyde. Polyacrylamide gel electrophoresis showed enhanced protein polymer formation with buffered phenol-formaldehyde (pH 7.0) as compared with neutral buffered 4% formaldehyde. Protein polymer formation increased in response to increased time and temperature. Cells fixed in suspension in buffered phenol-formaldehyde (pH 7.0) and neutral buffered 4% formaldehyde showed similar volume changes.

Animals↗
PubMed1989

Buffered phenol formaldehyde (pH 7.0 and pH 5.5): improved fixation in an enclosed tissue processor.

The addition of 2% phenol has a marked adjuvant effect on 4% formaldehyde as a fixative. Sequential use of phenol formaldehyde buffered to pH 7.0 and pH 5.5 results in improved fixation in material rapidly advanced to paraffin in an enclosed tissue processor. Sections stained with alum haematoxylin and eosin show improved nuclear and cytoplasmic detail, reduced tissue shrinkage and an absence of formalin pigment. Excellent results are obtained with conventional special stains and immunoperoxidase methods.

Fixatives↗
PubMed1988

Quantitation of human milk fat globule (HMFG1) expression in breast carcinoma and its association with survival.

Expression of human milk fat globule (HMFG1) in immunohistochemically stained sections of breast carcinomas was assessed subjectively and objectively from 82 women (age range 41-96 years) to determine its prognostic importance. No correlation was observed between the degree of staining and prognosis even when the subcellular distribution of antigen expression was assessed. The total absence of staining with HMFG1 was possibly associated with a favourable outcome, although this did not quite achieve significance with the small numbers involved. The Quantimet 970 was used for objective semiautomated measurement of immunohistochemical reactions in paraffin wax sections and was found to produce better resolution and to eliminate subjective error.

Adenocarcinoma↗
PubMed1979

Measurement by Quantimet 720 of the proportion of actively growing cells in tissue cultures of human lymphocytes.

The size-distribution of normal human lymphocytes growing in tissue culture was measured with a Quantimet 720 image-analysing computer. The proportion of cells undergoing volumetric growth after phytohaemagglutinin (PHA) stimulation was dervived from a simple mathematical model describing the growth patterns of the cells up to the first mitotic division. The approach may have general application in biology as a method for measuring the proportion of growing cells by microscopy.

Cell Count↗
PubMed1978

Grading of astrocytomas using a Quantimet 720 image-analysing computer.

Cerebral astrocytomas and undifferentiated gliomas were graded by (1) Kernohan classification on the basis of visual microscopy, and (2) optical density/area profiles obtained by automated densitometry with a Quantimet 720 image-analysing computer. In a retrospective study of 44 patients the Quantimet measurements seemed to give a more accurate assessment of prognosis than visual grading.

Adult↗
PubMed1978

Cytological basis of histological typing of diffuse Hodgkin's disease. Demonstration of an implied misnomer in the terminology of the Rye classification.

Differential cell counts were made on nine lymph nodes whose structure was replaced by diffuse Hodgkin's disease; two of these nodes had the classical histological appearance of the lymphocytic predominance subtype, four of the mixed cellularity subtype, and three of the lymphocytic depletion subtype. Our attempts to achieve valid sampling methods are recorded. The counts, in general, confirm the postulated histological basis of the Rye classification of the subtypes of the diffuse disease. The major discrepancy is that, contrary to the histological descriptions, our direct counts have shown that lymphocytes, are, in general, more numerous in the lymphocytic depletion than in the mixed cellularity subtypes. The cell counts also show that normal mononuclear cells (mainly fibroblasts and macrophage-type cells) are much more numerous in the mixed cellularity subtype than in the other forms of diffuse Hodgkin's disease; this feature has not been emphasised in the Rye classification. On the basis of our differential counts, a hypothesis is proposed that could explain the natural history of the different subtypes of diffuse Hodgkin's disease as the resultant of three processes: (a) tumour aggressiveness, (b) specific cell-mediated immunological reactions, and (c) non-immunological stromal responses.

Cell Count↗
PubMed1978

Bone marrow cellularity assessed by point-counting.

A simple method for rapid point-counting of bone marrow biopsies is described; the method gave an accurate assessment of cellularity in 100 aspiration biopsy specimens. Measurements of marrow cellularity by the visual point-counting technique correlated well with those obtained with a Quantimet 720 image-analysing computer.

Bone Marrow Cells↗
PubMed1972

Renal hyalin. A study of amyloidosis and diabetic fibrinous vasculosis with new staining methods.

This describes the sodium sulphate-Alcian Blue (SAB) method for staining amyloid in paraffin sections. Its value lies in the possibility of subsequent counterstaining and thus of revealing the structural relationships of amyloid. In the kidney the topical disposition of amyloid closely resembles the disposition of fibrin in the kidney of diabetics; this suggests that upset in vascular permeability plays a part in determining the site of the amyloid deposits. Furthermore, an aging process in amyloid can now be envisaged resembling the aging of extraluminal fibrin. Both materials proceed to a hyalin material that, staining like collagen, merits the name pseudo-collagen. This term we apply to a hyalin, staining like collagen, for which, we can postulate a specific precursor.

Amyloid↗