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  • 1
    ISSN: 1432-1203
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The molecular basis of the uroporphyrinogen III synthase (UROIIIS) deficiency was investigated in two members of a Japanese family. This defect in heme biosynthesis is responsible for a rare autosomal recessive disease: congenital erythropoietic porphyria (CEP) or Günther's disease. The first patient was homoallelic for a novel missense mutation: a T to C transition of nucleotide 634 that predicted a serine to proline substitution at residue 212 (S212P). The second patient appeared heteroallelic, carrying the same missense mutation and a nonsense mutation: a C to T change at nucleotide 745, resulting in a premature stop at codon 249, instead of a glutamine (Q249X). The corresponding mutated proteins were expressed inEscherichia coli and no residual activity was observed. A family study was also performed to determine the carrier status.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 1432-1203
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The molecular basis of the uroporphyrinogen III synthase (UROIIIS) deficiency was investigated in two members of a Japanese family. This defect in heme biosynthesis is responsible for a rare autosomal recessive disease: congenital erythropoietic porphyria (CEP) or Günther’s disease. The first patient was homoallelic for a novel missense mutation: a T to C transition of nucleotide 634 that predicted a serine to proline substitution at residue 212 (S212P). The second patient appeared heteroallelic, carrying the same missense mutation and a nonsense mutation: a C to T change at nucleotide 745, resulting in a premature stop at codon 249, instead of a glutamine (Q249X). The corresponding mutated proteins were expressed in Escherichia coli and no residual activity was observed. A family study was also performed to determine the carrier status.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    ISSN: 1432-2013
    Schlagwort(e): Key words Cell cycle ; Cytokinesis ; Heat shock protein 70 (HSP70) ; Temperature-sensitive mutant ; Thermotolerance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Cells of a temperature-sensitive mutant line (tsFT101) derived from a mouse mammary carcinoma cell line (FM3A) become multinucleated at a non-permissive temperature of 39°C because of disturbed cytokinesis. To explore how this relates to thermotolerance, we examined the proliferative activity of, and heat shock protein (HSP) expression in, FM3A and tsFT101 cells cultured at 37°C and 39°C after heat shock pretreatment (15 min exposure at 45°C). FM3A cells developed thermotolerance when cultured at both 37°C and 39°C, but whereas tsFT101 cells developed thermotolerance at 37°C, this was markedly reduced at 39°C. Western blot analysis showed similar degrees of expression of constitutive HSP70 (HSP73) in FM3A and tsFT101 cells after heat shock pretreatment at both 37°C and 39°C. However, expression of inducible HSP70 (HSP72) was reduced in tsFT101 cells at 39°C compared to 37°C and to FM3A cells at both 37°C and 39°C. Heat shock pretreatment activated DNA binding of heat shock transcription factor (HSF) in FM3A cells at 37°C and 39°C, but only at 37°C in tsFT101 cells. These results indicate that (1) multinucleation caused by disturbed cytokinesis increases temperature sensitivity, (2) HSP70 is critical for the development of thermotolerance in both FM3A and tsFT101 cells, and (3) decreased expression of inducible HSP70 parallels deficient development of thermotolerance in tsFT101 cells cultured at a non-permissive temperature.
    Materialart: Digitale Medien
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  • 4
    ISSN: 1432-2013
    Schlagwort(e): Key words Anti TGF-β receptor antibody ; Heat shock protein 70 ; Human skin fibroblast cell ; Transforming growth factor-β ; Ultraviolet B
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Ultraviolet B (UVB) alters the expression of heat shock protein 70 (HSP70) in cultured fibroblast cells derived from human skin. However, the nature of the signal transduction pathway remains to be determined. Transforming growth factor-β (TGF-β) has a large variety of biological functions, including cell growth control, modulation of inflammation and immunoregulation. In this study, we examined whether TGF-β is associated with the process of HSP70 expression induced by UVB irradiation. The constitutive expression of TGF-β1 mRNA and HSP70 expression in human skin fibroblast cells were detected using reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis. The results indicate that: (1) UVB irradiation stimulates HSP70 expression in a dose- and time-dependent manner, (2) constitutive expression of TGF-β1 mRNA is detected after UVB irradiation, the level of which peaks at 4 h after 10 mJ cm–2 of UVB irradiation, (3) HSP70 expression is induced by TGF-β1 without UVB irradiation, and (4) HSP70 expression induction with UVB irradiation is inhibited by preincubation of the cells with the anti-TGF-β type II receptor antibody. Our results suggest that HSP70 expression induced by UVB involves the autocrine signalling of TGF-β production.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1432-2013
    Schlagwort(e): Key words Cell division ; Cytokinesis ; G-actin ; F-actin ; Multinuclear cells ; Profilin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The temperature-sensitive mutant cells (tsFT101) derived from a mouse mammary carcinoma cell line, FM3A, become multinucleated at a non-permissive temperature of 39°C. To further understand the molecular mechanism of such cytokinetic disturbance, we examined the expression of profilin, the main regulator of the transition of globular actin (G-actin) to filamentous actin (F-actin). RT-PCR analysis of mouse profilin cDNA from tsFT101 showed a point mutation (177 A → G) which was a wobble mutation causing no change in the encoded amino acid. The expression level of profilin mRNA was, however, diminished in cultured tsFT101 cells under non-permissive temperatures compared with wild-type FM3A cells in association with multinucleation. A stable transfection of profilin cDNA expression vector to tsFT101 cells prevented multinuclear cell formation when cultured at 39°C. In contrast, antisense profilin cDNA expression vector did not alter multinuclear cell formation. The primary cause of the cytokinetic disturbance of tsFT101 cells may be due to the diminished level of profilin gene expression.
    Materialart: Digitale Medien
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  • 6
    ISSN: 1435-5604
    Schlagwort(e): hypoparathyroidism ; bone mineral density ; age-related bone loss
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Parathyroid hormone (PTH) is a key factor involved in the systemic regulation of bone resorption. It is well known that a high turnover of bone occurred together with the reduced bone mass in patients with hyperparathyroidism. However, the effect of subnormal secretion of PTH on age-related bone loss has not been extensively investigated. Recently, some investigators and us have focused on the effect of suppressed PTH secretion and have demonstrated that patients with subnormal secretion of PTH preserved a relatively higher bone mineral densities than age- and sex-matched controls. We believe that these results will give a new insight into the mechanism of age-related bone loss or osteoporosis. Further studies are needed to evaluate the mechanisms of this protective effect of suppressed PTH secretion on bone mass.
    Materialart: Digitale Medien
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  • 7
    ISSN: 1436-2023
    Schlagwort(e): Key words: apoptosis, articular chondrocyte, osteoarthritis, rheumatoid arthritis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract: To investigate the relationship of chondrocyte apoptosis and cartilage destruction, we performed in situ nick end labeling (ISNEL), electron microscopy, and im-munohistochemistry against apoptosis-related proteins, p53 and c-myc, in the articular cartilages of patients with rheumatoid arthritis (RA; n = 12) and osteoarthritis (OA; n = 12), and in control articular cartilages from patients with femoral neck fracture (n = 8). The distribution of stained chondrocytes was evaluated semiquantitatively in relation to the degree of cartilage destruction. ISNEL-positive chondrocytes with apoptotic morphological features were identified in a relatively early phase of cartilage destruction, and correlated positively and significantly in a number with the degree of cartilage degeneration. Comparison of RA and OA revealed a significantly greater number of ISNEL-positive chondrocytes in RA cartilage. In contrast, the specimens of normal subjects contained few cells with apoptotic changes. Similarly to the distribution of ISNEL staining, the expression of p53 and c-myc proteins was observed in chondrocytes within the degraded lesions, and showed a positive correlation with the number of ISNEL-stained cells. These results suggest that the degree of chondrocyte apoptosis is closely related to cartilage destruction and that chondrocytes in RA more readily undergo apoptosis than those in OA. The expression of p53 and c-myc proteins in ISNEL-positive areas may reflect the involvement of these proteins in the apoptotic process in articular chondrocytes in inflammatory arthritis.
    Materialart: Digitale Medien
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  • 8
    ISSN: 1573-6830
    Schlagwort(e): saccus vasculosus ; nucleus of the saccus vasculosus ; choroid plexus ; parathyroid hormone-related peptide (PTHrP) ; PTHrP receptor ; red stingray ; immunohistochemistry ; immunoradiometric assay
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract 1. The exact role of the parathyroid hormone-related peptide (PTHrP) is not fully understood. We used immunohistochemistry to localize the PTHrP and its receptor in the brain of the red stingray, particularly in the saccus vasculosus (SV) and choroid plexus. 2. Immunoreactive PTHrP and its receptor were detected in the epithelial cells of the SV and the choroid plexus. In addition, the neuronal perikarya in the nucleus of the SV located in the hypothalamus is positive for the PTHrP. 3. No PTHrP-containing neurons were detected in the choroid plexus. Extracts of SV and choroid plexus showed positive reactions against the PTHrP and its receptor antibody in Western blot analysis. 4. High levels of immunoreactive PTHrP were detected in the plasma equivalent to those present in human humoral malignant hypercalcemia. In contrast, the immunoreactive PTHrP concentration in the cerebrospinal fluid was below detectable levels. 5. Our results suggest that the regulation of the PTHrP in the SV differs from that in the choroid plexus in the red stingray.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1573-6830
    Schlagwort(e): 125I-labeled insulin-like growth factor-I binding sites ; rat forebrain ; rat pituitary gland ; quantitative receptor autoradiography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary 1. Specific125I-labeled insulin-like growth factor-I ([125I] IGF-I) binding sites in the rat forebrain and pituitary gland were investigated using quantitative receptor autoradiography. 2. High densities of [125I]IGF-I binding sites were present in the olfactory nerve layer, olfactory glomerular layer, choroid plexus, CA3 and CA4 of the hippocampus, basolateral amygdaloid nucleus, and endopiriform nucleus. Moderate to high binding densities were found in the cerebral cortex (II, VI), bed nucleus stria terminalis, accumbens nucleus, lateral septum, median preoptic nucleus, supraoptic nucleus, paraventricular hypothalamic nucleus, and ventroposterior thalamic nucleus. In the circumventricular organs, subfornical organ, vascular organ of the lamina terminalis, and median eminence, the binding sites were numerous. High densities of [125I]IGF-I binding sites were also observed in the anterior pituitary gland. 3. In kinetic experiments, [125I]IGF-I binding sites in the olfactory glomerular layer, choroid plexus, median eminence, and anterior pituitary gland were found to be single and of a high affinity. 4. Noteworthy was the difference in the potency of insulin in inhibiting the binding among the areas examined, a finding which suggests heterogeneity of IGF-I receptors. 5. The possibility that IGF-I plays the role of a neurotransmitter and/or neuromodulator in the central nervous system warrants further investigation.
    Materialart: Digitale Medien
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  • 10
    ISSN: 1573-7403
    Schlagwort(e): combined pituitary hormone deficiency (CPHD) ; prophet of Pit-1 (Prop-1) ; 2-base pair deletion GA296 ; Russia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Combined pituitary hormone deficiency (CPHD), including growth hormone (GH), prolactin (Prl) and thyroid-stimulating hormone (TSH) in children is now considered a heterogeneous syndrome. Recent findings on expression of mouse pituitary-specific homeodomain factors demonstrate dependence of adenopituitary ontogeny on interactive expression of these factors, suggesting their involvement in etiology of CPHD. Prophet of Pit-1 (Prop-1) gene, a novel pituitary-specific homeodomain factor, was analyzed in 14 Russian children with CPHD, in whom Pit-1 gene was intact. We found a mutational hot spot in three patients from two families in homeodomain part of the second exon of Prop-1 gene. The common 2- base pair deletion (GA296) in the homozygous state resulted in a Serine to Stop codon (S109X) substitution and generated a truncated Prop-1 protein. Parents were phenotypically normal and heterozygous for GA296 deletion, indicating an autosomal recessive inheritance. These results demonstrate a novel type of Prop-1 gene mutation as one of the causes of CPHD in Russian patients.
    Materialart: Digitale Medien
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