PubMed Health⌕ Search

Biomedical subjects

C J Meyer

Publications and source records attributed to C J Meyer.

67 records · Page 4Linked to original sources
PubMed1976

Morphological differences in the interactions between human mononuclear cells and coated or uncoated sheep red blood cells: a freeze-etch study of different types of rosettes.

Enriched preparations of E, EA and EAC rosettes formed by human peripheral blood mononuclear cells were freeze-etched and examined electron-microscopically. In E rosettes only lymphocyte were involved, whereas in EA and EAC rosettes lymphocytes and mononuclear phagocytes participated as rosette-forming cell. In EA and EAC rosettes, cytoplasmic extensions of the rosette forming cell were seen to penetrate the sheep red blood cell, whereas E rosettes showed a broad zone of adherence without penetration. None of the three types of rosettes showed an interspace between the membranes. Unlike E rosettes, EA and EAC rosettes showed polarity in the adherence of sheep red blood cells. These observations made by freeze-etch electron microscopy indicate distinct morphological differences between rosettes formed with coated or uncoated erythrocytes.

Animals↗
PubMedDate not supplied

Detection and characterization of metastatic cervical adenopathy by MR imaging: comparison of different MR techniques.

Thirty-five patients scheduled to undergo a neck dissection for squamous cell carcinoma of the head and neck were evaluated preoperatively by magnetic resonance (MR) imaging. Axial and occasionally sagittal and coronal images were obtained. To define the most reliable technique to detect cervical lymph node metastasis, we compared several MR pulse sequences with and without Gd-DTPA administration to histopathologic findings in the neck dissection specimens. T1-weighted spin echo combined with T2-weighted gradient recalled echo (GE) sequences were found to be more useful than any other combination of pulse sequences in localizing lymph nodes. On T2-weighted GE images, lymph nodes were depicted with intermediate to high signal intensity in contrast to low signal muscular and fatty tissue. Gadolinium DTPA enhanced T1-weighted GE images reliably depict central lymph node necrosis, the most specific criterion for lymph node metastasis.

Adult↗
PubMedDate not supplied

The clinical relevance of classification of squamous cell hyperplasia of the larynx by morphometry.

By means of morphometry, differentiation between the classes of laryngeal squamous cell hyperplasia can easily be performed, mutually (Kleinsasser's classification) and in comparison with normal epithelium. It is rather difficult, however, to distinguish between class II (hyperplasia and atypia) and class III (carcinoma in situ). In the group of class II lesions, two groups of patients could be differentiated: a prognostically favourable and an unfavourable group. When using a linear discriminant analysis, the two groups mentioned could be distinguished morphometrically. In histopathological examination, lesions classified as hyperplasia and atypia (class II), must also be examined with morphometry, because in this way the group at risk can be traced.

Biopsy↗
PubMedDate not supplied

The effect of selenium on phagocytosis in humans.

The effect of selenium on immune responses in animals and humans is controversial. It has been reported that phagocytosis as a part of the immune function is affected by selenium deficiency. We conducted a study to investigate the effect of selenium on the phagocytic function of polymorphonuclear leukocytes (PMNs) in normal healthy individuals before and after selenium supplementation. Ingestion of sodium selenite 400 micrograms/day (182.8 micrograms pure selenium) resulted in a significant increase in plasma selenium levels. The phagocytic function of PMNs was measured by ingestion of Oil Red O paraffin droplets and chemiluminescence tests. The phagocytic function was increased, but the results before and after selenium supplementation were not significant. It was concluded that inorganic selenium was not an efficient stimulating agent of phagocytosis in humans.

Humans↗
PubMedDate not supplied

Interferon as a modifier of estrogen receptors.

Interferon (IFN-alpha) increased estrogen receptor (ER) activity in human breast cancer tissue, human uterus (endometrium), and rabbit uterus. The optimum response was obtained with three different doses of IFN-alpha 10, 100, and 1000 U per ml. Escalation of the dose up to 5000 U per ml did not increase further ER activity. Cytosol fractions with zero or low binding activity (below 10 fm per mg) did not respond to IFN-alpha treatment. Addition of antibodies against IFN-alpha resulted in abrogation of IFN-alpha effect. Use of recombinant IFN-alpha or highly purified lymphoblastoid IFN-alpha showed similar effects on ER. The mechanism of the augmentation effect of ER activity by IFN-alpha is not clear. The increase of ER activity may have important clinical applications if the same is obtained in vivo.

Animals↗