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T Papp

Publications and source records attributed to T Papp.

At least 37 records · Page 2Linked to original sources
PubMed1995

Mineral fibers induce apoptosis in Syrian hamster embryo fibroblasts.

It is known that asbestos and other mineral fibers induce lung cancer and mesothelioma. However, the primary mechanisms of fiber-induced carcinogenesis still remain to be elucidated. Previous studies, including our own, have shown that asbestos causes specific mitotic disturbances, micronucleus formation and typical changes in chromatin structure resembling those of apoptosis. This effect has been considered as programmed cell death removing damaged or pre-cancerous cells. We investigated the induction of apoptosis by asbestos (amosite, crocidolite, chrysotile) and ceramic fibers. The typical ladder pattern of DNA fragments was identified by means of gel electrophoresis, the intracellular calcium concentration was measured and flow cytometry analyses were carried out to determine the percentage of apoptotic cells. The different fibers showed different potencies for the induction of apoptosis in Syrian hamster embryo (SHE) cells. Depending on the type of fiber applied 3-33% of cells underwent apoptosis. Chrysotile proved to be the most potent inducer of apoptosis compared to the other fibers. In addition, an increase intracellular calcium level was observed in apoptotic SHE cells. Chrysotile induced apoptosis after a considerably longer exposure time (66-72 h) than cisplatin (24 h). In view of these findings we hypothesize that chrysotile induces apoptosis resulting from long-term changes in intracellular regulation pathways.

Animals↗
PubMed1995

Trefoil configuration and developmental stenosis of the lumbar vertebral canal.

The midsagittal and interpedicular diameters and the trefoil shape of lumbar vertebrae of known age at death were measured in skeletons from a population aged between 1 and 70 years. All the trefoil configurations were at L5 with the exception of one at L4. The overall prevalence was 25%, but this shape was not generally apparent until adulthood. The midsagittal diameter in the trefoil canals was found to be significantly smaller than that in the unaffected canals. This did not change significantly after six years of age indicating that the cause of the trefoil configuration is probably present early in life. The trefoil shape was no more common in the spines of the elderly subjects. Our findings indicate that the trefoil configuration of the lumbar vertebral canal has a developmental origin and is not a consequence of degenerative processes.

Adult↗
PubMed1994

The growth of the lumbar vertebral canal.

STUDY DESIGN: This study examines the growth and development of the lumbar spinal canal with emphasis on early life. OBJECTIVE: Changes in dimensions of the canal were investigated throughout life. SUMMARY OF BACKGROUND DATA: Seven hundred and fifteen lumbar vertebrae were examined from the Spitalfield Collection of Skeletons at the Natural History Museum, London. METHODS: Unmagnified silhouette pictures were taken of the canals with a specially designed photographic box. Computerized image analysis provided the accurate measurements. RESULTS: Regarding the midsagittal diameter and the cross-sectional area, the cranial four lumbar vertebrae were already fully matured in infants. At L5 there was significant increase up to 4 years of age when the midsagittal diameter was even larger than in the adult. The interpedicular diameter significantly increased at L1 until 10 years of age, at the other levels until adulthood, as did the perimeter at L4 and L5 until 14 years of age. The shape of the canal was assessed by measuring the circularity, the 'trefoilness' and the situation of the centroid. The first measurement significantly decreased with age, the trefoilness increased until adulthood, and the centroid of the canal approached the vertebral body. In spines with spina bifida occulta, the lumbar canal was significantly larger proximal to the lesion than in the unaffected spines. CONCLUSION: The lumbar spinal canal exhausts its growth potential by infancy as regards the midsagittal diameter and the cross-sectional area. Thus, in the case of delayed development, it is not capable of catch-up growth.

Adolescent↗
PubMed1994

Changes of the lumbar spinal canal proximal to spina bifida occulta. An archaeologic study with clinical significance.

STUDY DESIGN: This archaeologic study, based on four populations, examines the incidence of spina bifida occulta in the lumbar spine and the size of the vertebral canal proximal to the lesion. OBJECTIVES: To ascertain any significant change in the dimensions of the lumbar spinal canal of skeletons with spina bifida occulta. The incidence of the lesion also was compared in the separate genetic groups. METHODS: Central canals of 1760 lumbar vertebrae were examined. Silhouette, unmagnified pictures of the vertebral canals were measured by computerized image analysis. RESULTS: The mid-sagittal diameter at L4 and L5 and the cross-sectional area at L5 were found to be significantly larger proximal to the lesion compared with the unaffected spines. The overall incidence was 18%. CONCLUSIONS: The capacity of the lumbar canal is greater proximal to spina bifida occulta. Therefore, delayed closure of the neural arch at a single segment has morphologic significance to the more proximal spine.

Adolescent↗
PubMed1993

Cytogenetic changes in primary, immortalized and malignant mammalian cells.

Some chromosomes in transformed rat cells and somatic cell hybrids fail to display the presence of kinetochore proteins as detected by antikinetochore antibodies. Such chromosomes (K- chromosomes) may constitute a novel mechanism for the genesis of aneuploidy. We have analyzed primary, immortalized and malignant mammalian cells for the presence of kinetochore proteins and micronuclei. Our results suggest a correlation of the K- chromosome and micronucleus frequency with the variability in chromosome number. Upon in situ hybridization with the minor satellite and alpha satellite sequences some K- chromosomes showed a signal. This indicates that the observed lack of kinetochores is not necessarily due to a lack of centromeric DNA. We conclude that dislocated K- chromosomes may become incorporated into micronuclei which are prone to loss. Such events would be associated with the generation of aneuploidy.

3T3 Cells↗
PubMed1992

[Management of agricultural injuries at our department].

Authors want to call attention with the presentation of 4 cases to the significance of the agricultural injuries and to the difficulties of the therapy. The importance of the primary wound care is stressed. An adequate excision of the wound, debridement and an open wound care are essential in severely crushed, soiled cases. Therapy of severely crushed injuries, complicated with multiple fractures needs individual weighing and a reconstruction in more sittings.

Accidents, Occupational↗
PubMed1991

Mapping of phenytoin-inducible cytochrome P450 immunoreactivity in the mouse central nervous system.

The distribution of phenytoin-inducible cytochrome P450 in non-treated mouse brain and spinal cord was analysed immunohistochemically using polyclonal antibodies against phenytoin-induced mouse cerebral microsomal P450. This P450 protein was proved in Ouchterlony [Volk B. et al. (1988) Neurosci. Lett. 84, 219-224], Western blot, and immunohistochemical analyses to be reactive to the specific antibodies and an IgG fraction raised against phenobarbital-induced rat liver microsomal P450IIB1. The phenytoin-induced P450 is designated P450IIB1* because immunologically it is comparable with P450IIB1; however, it has not yet been analysed for other characteristics of this enzyme. Immunocytochemistry was performed on acetone-fixed serial cryosections of the whole brain using the avidin-biotin-peroxidase detection system. Negative controls included incubations with preimmune serum of the immunized animal instead of the primary antibody and preabsorption of the antibody with the corresponding immunogen. The pattern of immunoreactive sites indicates that P450IIB1* is not distributed evenly throughout the CNS. It was found to be restricted to only some cellular populations. The most striking aspect of immunostaining was a predominant reactivity in the evolutionary old brain parts. Neuropil and neuronal staining was found in the spinal cord (motor neurons of the ventral horn), medulla oblongata (hypoglossal nuclei, magnocellular part of the lateral reticular nuclei), pons (trigeminal, facial, cochlear and pontine nuclei), cerebellum (granule cells), midbrain (dorsal raphe nucleus) and limbic lobe (hippocampal pyramidal cells). Neuropil reactivity alone appeared in cerebellar nuclei, midbrain, thalamus, basal ganglia, neopallium and olfactory brain. Generally, pia mater/arachnoid, ependyma, choroid plexus, vascular system and some astrocytic populations were found to be strongly P450IIB1* immunoreactive. In comparison with astroglia, which is characterized by glial fibrillary acidic protein-positiveness, the astrocytes, which are also P450IIB1* reactive, occurred only in subpial and subependymal layers, and in large fiber tracts of the spinal cord and brainstem, where they were attached to the vascular system. Otherwise, the glial fibrillary acidic protein-positive astrocytes were not P450IIB1* immunoreactive in the cerebellar molecular layer (fibers of Bergmann glia), in remaining neuropils and in white matter areas.

Animals↗
PubMed1990

Experiences in the Ebrimycin gel treatment of burns.

Ebrimycin gel has been used for the local treatment of burns of 50 partly hospitalized patients, partly outpatients. According to the observations the product may be successfully used by the exposure method for the treatment of superficial facial burns and by the occlusive dressing method for the treatment of small burns which are infected by Gram-positive bacteria.

Administration, Topical↗
PubMed1989

Differentiation between papillary and nonpapillary renal cell carcinomas by DNA analysis.

Recent studies have shown that the deletion of chromosome 3p or the loss of DNA sequences at 3p is generally associated with the development of renal cell carcinoma (RCC). However, chromosome analysis of some papillary RCCs suggested that this type of tumor differs genotypically from the most common nonpapillary RCCs. Therefore, by using cytogenetic and molecular genetic approaches, we examined human papillary and nonpapillary RCCs for the loss of heterozygosity or homozygosity at the short arm of chromosome 3. The constitutional heterozygosity for the DNF15S2 locus and for one allele of the c-erbA beta and the c-raf-1 proto-oncogenes was lost in nonpapillary RCCs, whereas both alleles were retained in each papillary RCC analyzed. We conclude that the loss of DNA sequences at the chromosome 3p region is a genomic change occurring consistently in nonpapillary RCCs, but never occurring in papillary RCCs.

Carcinoma, Renal Cell↗