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Biomedical subjects

M Faber

Publications and source records attributed to M Faber.

At least 91 records · Page 5Linked to original sources
PubMed1986

Laminin production by human endometrial stromal cells relates to the cyclic and pathologic state of the endometrium.

The cyclic changes in the presence of the basement membrane glycoprotein laminin in endometrial stromal cells was studied by immunohistochemistry. The interstitial matrix around the stromal cells of the proliferative phase of the normal menstrual cycle was unreactive with antibodies to laminin. However, commencing with the secretory phase, stromal cells accumulated distinct cytoplasmic and pericellular laminin-immunoreactive material. The maximal amount of stromal cell-associated laminin was observed in predecidual cells of the late secretory phase. Thus, laminin immunostaining discriminates stromal cells of the proliferative phase (being "negative") from those in the secretory phase (being "positive"). Sixty-six cases of endometrial hyperplasia and adenocarcinomas were also stained with antibodies to laminin. Sixty-nine percent of biopsies of cystic hyperplasia and 30% of adenomatous hyperplasia contained laminin-positive stromal cells. Ultrastructural examination of stromal cells in cystic hyperplasia revealed the presence of pericellular basement membrane-like material, focally arranged into typical lamina rara and lamina densa. In contrast, stromal cells in the atypical adenomatous hyperplasia and adenocarcinomas did not react with antibody to laminin. The expression of laminin receptor in the stromal cells codistributed with laminin. Basement membranes of the surface epithelium, the glandular epithelium, and the vessels stained strongly with antibodies to laminin. In preneoplastic and neoplastic tissues, laminin immunostaining revealed discontinuous and defective basement membranes. In poorly differentiated carcinomas only sparse amounts of laminin-positive basement membrane were observed; these tumors, in contrast, exhibited cytoplasmic laminin and also significant immunoreaction with antibodies to laminin receptor.

Basement Membrane↗
PubMed1985

Abnormal lymphocyte response to u.v. radiation in multiple skin cancer.

The lymphocyte response to u.v. radiation (254 nm) was investigated by two different methods in 29 unselected patients with multiple epidermal cancer. The u.v.-induced DNA synthesis was determined as the increase in incorporation of [3H]thymidine in irradiated cells compared with nonirradiated cells after incubation for 2 h. The u.v. tolerance was measured as the u.v. dose necessary for 50% reduction in phytohemagglutinin-stimulated lymphocyte proliferation. Patients with both squamous cell differentiated tumors and basal cell carcinomas had very high u.v.-induced DNA synthesis values (p less than 0.01, when compared with patients with basal cell carcinoma only and p less than 0.005, when compared with controls). The u.v. tolerance in patient lymphocytes was considerably lower than in control lymphocytes (p less than 0.001), with the lowest values occurring in patients with clinical sun intolerance (p = 0.05, when compared with the remaining patients). These investigations may be of predictive value in skin carcinogenesis.

Adult↗
PubMed1985

Seasonal variations in UVR-induced DNA synthesis and in UVR inhibition of phytohaemagglutinin-stimulated proliferation of human lymphocytes.

Two years of sequential studies of the UVR (254 nm) response in normal human lymphocytes showed pronounced seasonal variations. In the winters of 1981-82 and 1982-83 the UVR-induced DNA synthesis in the lymphocytes in vitro (the DNA-repair synthesis) was very stable with inter- and intra-individual variations below 14 and 10%, respectively (15 individuals). In the summers 1982 and 1983 the inter-individual variations was 2-3-fold higher. Closer analysis revealed that this was due to a pronounced intra-individual variation with sharp fluctuations in the single individual. Also the UVR tolerance of the lymphocytes estimated by alterations of the phytohaemagglutinin (PHA) stimulated lymphocyte proliferation showed seasonal variations, being 1.5-fold higher in the winter than in the summer (P less than 0.0001, 12 individuals). The observed seasonal variations emphasize the importance of considering chronobiological variations when working with long term projects. The UVR-induced DNA synthesis was determined as the increase in incorporation of [3H]-thymidine in irradiated cells compared to non-irradiated cells after incubation for 2 h at 37 degrees C in phosphate buffered saline. The UVR tolerance was measured by the UV dose necessary for 50% reduction in PHA stimulated lymphocyte proliferation assessed after 7 days of growth.

Adult↗
PubMed1985

Immunochemical and ultrastructural assessment of the nature of the pericellular basement membrane of human decidual cells.

Human decidual cells of early and late pregnancy were studied immunochemically and ultrastructurally with respect to the presence and nature of pericellular basement membrane material. The most prominent cell type in decidual tissue of both early and late pregnancy were large, mature epithelioid decidual cells (greater than 25 micron) with a distinct pericellular basement membrane, containing at least laminin, type IV collagen, heparan sulfate proteoglycan, and fibronectin. Laminin was extracted from the decidual tissue at a concentration of 3 micrograms/gm as measured by enzyme-linked immunosorbent assay. Biosynthesis of laminin was shown by [35S]methionine labeling of short term organ cultures of decidual tissue followed by immunoprecipation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and fluorography. The laminin chains migrated with the apparent molecular weights of 300 and 200 kilodaltons under reducing conditions. Two other separate populations of cells were apparent in the decidual tissue of early pregnancy. A smaller group of rounded intermediate sized (15 to 25 micron) decidual cells had focal deposits basement membrane immunoreactive material scattered at the cell surfaces. Ultrastructurally, clumps of electron dense basement membrane material were present in close vicinity to the cell membrane. Occasional populations of small (greater than 15 micron) elongated fibroblastic-like cells were identified which did not display any immunoreactivity for any of the investigated basement membrane components. The two latter populations of decidual cells were not observed in the decidual tissue investigated from the placental bed of late pregnancy. It is suggested that these three types of decidual cells might represent various stages of the sequential differentiation of stromal cells into decidual cells of the pregnant endometrium. Predecidualization of the human endometrium, which is seen in the late secretory phase of the normal menstrual cycle and in some states of hyperplasia, was also shown to be accompanied by the presence of deposits of laminin-positive material at the cell surfaces. In the latter case, these cells resembled the intermediate sized decidual cells of the pregnant endometrium. In conclusion, the results suggest that the process of decidualization and predecidualization can be characterized morphologically and immunochemically by the accumulation of basement membrane material in specific decidua cell subpopulations.

Adult↗
PubMed1984

[Eprazinone exanthema with subcorneal pustulosis].

A drug eruption with subcorneal pustulation is presented, occurring in a patient during treatment with eprazinone . The biopsy of the initial lesions showed changes as in pustulosis subcornealis . The aetiopathogenetic relationship between administration of eprazinone and the pustular eruption was confirmed by patch test.

Exanthema↗
PubMed1981

A light and electron microscopic study of bowenoid papulosis.

Bowenoid papulosis of the genito-anal region was studied by light- and electron-microscopy. Histopathologically there was no difference between bowenoid papulosis and ordinary Bowen's disease. Conspicuous ultrastructural findings included: great variation of intercellular spaces, decrease in intact desmosomes, aggregation of tonofilaments resulting in dyskeratosis, and two types of intracellular vacuolization probably caused by invagination of plasma membrane.

Adult↗
PubMed1979

Mitotic index, influx and mean transit time in the hamster cheek pouch epithelium, a partially synchronized cell system. Presentation of a mathematical model based on a non-stationary probability density function for the transit time in a compartment.

Mitotic activity was followed in the epithelium of the hamster cheek pouch for about 12 hr in two experiments under different conditions of noise and light intensity. A mathematical model based on a non-stationary probability density function for the transit time through mitosis was developed, making an analysis of this partially synchronized cell system possible. The most important result of the two experiments is the indication of a non-stationary mean transit time for cells in mitosis. In the first experiment (70 dB, 103 lux), which produced high mitotic indices (maximum 2.0%), the influx changed from 0. to 0.9%/hr (mean of 7-hourly determinations: 0.4%/hr), and the mean transit time from 1.9 to 5.5 hr. In the second experiment (70 dB, 265 lux), which had a lower level of MI (maximum 1.3%), the influx changed from 0 to 1.8%/hr (mean of 13-hourly determinations: 0.4%/hr), and the mean transit time from 0.3 to 3.3 hr. It was difficult to say precisely whether the variation in influx or in mean transit time was the main factor in the increase and decrease of MI. The data could not be simulated with a stationary mean transit time. It is suggested that changes in MI due to different external circumstances are mainly the result of variation in the mean transit time.

Animals↗
PubMed1978

Morphological study of the ovaries of leukaemic children.

The ovaries of leukaemic children were studied in 31 specimens obtained at autopsy. Twenty-eight ovaries from normal children of the same age who died from misadventure served as control. All ovaries from normal childred showed follicle growth and contained several large antral follicles. Follicle development was inhibited in all ovaries of leukaemic children; 22% showed no follicle growth (quiescent ovaries), and in the ovaries in which there was follicle development, the number and size of antral follicles was significantly smaller than in the control. All children had been treated with cytotoxic drugs, the duration of the treatment being correlated with the stage of ovarian development. The ovaries of children treated for only 1 week were near-normal, while those treated for more than 2 months showed inhibition of follicle growth. It is argued that the disturbance in follicle development is an effect of the cytotoxic drugs, and not an effect of the disease itself.

Acute Disease↗
PubMed1978

Follicular development in ovaries of children with Down's syndrome.

Ovaries of children with Down's syndrome were examined histologically in order to determine in what way the ovarian development differed from the normal. Twenty-six specimens obtained at autopsy at various ages between birth and 14 1/2 years were available and compared with ovaries from normal children of similar ages. All ovaries from normal children were characterized by active follicle growth. The ovaries of the children with Down's syndrome, however, showed absence or retardation of follicle growth. Furthermore the number as well as the size of the antral follicles differed from those in the normal ovary. The decrease of the number of small follicles occurs earlier in life in the ovaries of children with Down's syndrome than in the control. The possible relationship between an abnormal ovarian growth pattern and hormonal imbalance is discussed.

Adolescent↗