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W Vogel

Publications and source records attributed to W Vogel.

At least 163 records · Page 9Linked to original sources
PubMed1997

XX-agonadism in a fetus with multiple dysraphic lesions: a new syndrome.

We report on a 19-week-old fetus with a 46,XX karyotype, normal female external genitalia, complete gonadal agenesis, large encephalocele, spina bifida, and omphalocele. We postulate a new syndrome. Hitherto no consistent malformation patterns have been observed in agonadism patients. True agonadism, including even the unusual finding of an XX gonosomal status, is obviously not as rare as suggested.

Abnormalities, Multiple↗
PubMed1997

Papillitis and vasculitis of the arteria spinalis anterior as complications of hepatitis C reinfection after liver transplantation.

It is well known that hepatitis C virus (HCV)-related chronic liver disease may be associated with various immunological disorders including mixed cryoglobulinemia, which is accompanied by cutaneous vasculitis, arthralgias, membrano-proliferative glomerulonephritis, and neuropathy in association with cryoprecipitable immune complexes in serum. We describe here the first case of central nervous system HCV infection with evidence of the virus in the cerebrospinal fluid in association with cryoglobulinemia in a patient who developed recurrent episodes of papillitis and vasculitis of the arteria spinalis anterior after liver transplantation.

Adult↗
PubMed1997

Unidirectional upregulation of the synthesis of the major iron proteins, transferrin-receptor and ferritin, in HepG2 cells by the acute-phase protein alpha1-antitrypsin.

BACKGROUND/AIMS: We have previously shown that the hepatic acute-phase protein alpha1-antitrypsin (alpha1-AT) is an important mediator of changes in iron metabolism in the course of anaemia of chronic disease. Alpha1-AT profoundly reduces growth of erythroid cells by interfering with transferrin-mediated iron uptake. In the present work we investigate the effects of alpha1-AT on hepatic iron metabolism, as the liver plays a central role in body iron metabolism and in metabolic changes during acute-phase response. METHODS: The human hepatoma cell line Hep G2 was cultured in RPMI 1640+10% FCS. The effect of alpha1-AT on transferrin-receptor binding was investigated in equilibrium binding assays with 125I-transferrin. Expression of transferrin receptor was determined by saturation experiments and intracellular ferritin was measured in cell lysates after incubating cells either alone or with alpha1-AT. To determine iron regulatory protein binding activity to iron responsive elements we used gel retardation assays and Northern blot analysis was carried out to investigate transferrin receptor and ferritin mRNA expression. RESULTS: Alpha1-AT completely prevented transferrin from binding to its receptor and internalization of the transferrin-transferrin receptor complex on HepG2. In addition, alpha1-AT caused a distinct increase in iron regulatory protein binding activity to iron responsive elements, which is characteristic of iron deprivation. Normally, the synthesis of transferrin receptor and ferritin is regulated bidirectionally, but alpha1-AT promoted a unidirectional regulation. Alpha1-AT increased the synthesis of both transferrin receptor and ferritin and, moreover, increased cellular amounts of transferrin receptor mRNA and ferritin H-chain mRNA. CONCLUSIONS: The effect of alpha1-AT on transferrin receptor synthesis appears to be mediated via activation of iron responsive element binding affinity of iron regulatory protein leading to an increased stability of transferrin receptor mRNA. Changes in ferritin, however, may be related to a transcriptionally mediated, iron-independent pathway which overrides the influence of activated iron regulatory protein. These specific changes in iron metabolism are the very ones seen in the course of anaemia of chronic disease. Our results emphasize the central role of alpha1-AT as a mediator of altered iron metabolism, characteristic of anaemia of chronic disease, not only with respect to erythroid cells but also with respect to liver cells.

Cell Division↗
PubMed1997

Predominance of the HLA-H Cys282Tyr mutation in Austrian patients with genetic haemochromatosis.

BACKGROUND/AIMS: Genetic haemochromatosis is the most common autosomal recessive disorder in Northern European populations. A major histocompatibility complex class I-like gene, HLA-H, has been proposed to be responsible for genetic haemochromatosis. The prevalence of HLA-H gene mutations 282(TGC; Cys/TAC; Tyr) and 63(CAT; His/GAT; Asp) was determined in patients of Austrian origin. METHODS: DNA extracted from the blood of 40 Austrian patients and 271 controls was used to amplify HLA-H gene fragments by the polymerase chain reaction method. The base changes responsible for mutations Cys282Tyr and His63Asp alter recognition sites for restriction enzymes SnaB I and Bcl I, respectively. Digestion products were separated by agarose gel electrophoresis and visualised by ethidium bromide staining. RESULTS: Thirty-one (77.5%) genetic haemochromatosis patients were homozygous for mutation Cys282Tyr and three compound heterozygous for mutations Cys282Tyr and His63Asp. One patient was homozygous for mutation His63Asp but normal for mutation Cys282Tyr. Four patients were normal at both genetic loci and one patient was heterozygous for mutation His63Asp. One control subject homozygous for mutation Cys282Tyr was found on investigation to fulfill diagnostic criteria for haemochromatosis. Eight control subjects homozygous for mutation His63Asp showed no biochemical or clinical evidence of haemochromatosis indicating that this variant is not directly responsible for haemochromatosis. Absence of the Cys282Tyr mutation in six genetic haemochromatosis patients with distinct haplotypes indicates mutations within the HLA-H gene or at alternative genetic loci are the cause of genetic haemochromatosis in these patients. CONCLUSIONS: The HLA-H Cys282Tyr defect is likely to play a key role in the pathogenesis of haemochromatosis in most patients. Predominance of a single HLA-H gene mutation in haemochromatosis allows presymptomatic screening by genotypic analysis.

Adult↗
PubMed1997

Relationships of serum estradiol levels, menopausal duration, and mood during hormonal replacement therapy.

A study was undertaken in 38 menopausal women on-cyclic HRT (estropipate) and estropipate + nor-ethindrone). Serum estradiol levels during treatment were related to mood changes and platelet MAO activity. The relationship between serum estradiol levels and mood changes was found to be a function of the duration of menopause. Women with a short duration of menopause (12.9 months +/- 6.1) were compared to women with a long duration of menopause (76.6 months +/- 52.3). Women with a short duration of menopause had significantly lower mean serum estradiol levels during HRT compared to women with a long duration of menopause (216.9 +/- 62.3 vs. 291.13 +/- 118.12, respectively, p < .02). It had previously been reported that estrogen treatment in menopausal women had a positive effect on mood, whereas the combination of estrogen plus a progestin had a negative effect on mood. We found that the women with a long duration of menopause and higher treatment serum estradiol levels had significantly more dysphoria when receiving a combination of estrogen plus progestin than did the women with a short duration of menopause and lower serum estradiol levels. However, both short and long duration menopausal groups showed improvement in mood when estrogen was administered alone. Platelet MAO levels, a marker of adrenergic and serotonergic function thought to relate to mood, were negatively correlated with serum estradiol levels during HRT. We suggest that these paradoxical findings may be secondary to a prolonged estrogen deficiency state in women with a long duration of menopause.

Affect↗
PubMed1997

The discoidin domain receptor tyrosine kinases are activated by collagen.

Two mammalian receptor tyrosine kinases (DDR1 and DDR2) have extracellular domains closely related to a D. discoideum lectin, discoidin, required for cell aggregation. Here, we show that the mammalian DDR receptors bind and are activated by specific types of collagen. Stimulation of DDR receptor tyrosine kinase activity requires the native triple-helical structure of collagen and occurs over an extended period of time. Collagen activation of DDR1 induces phosphorylation of a docking site for the Shc phosphotyrosine binding domain, whose presence is controlled by alternative splicing. Activation of DDR2 by collagen results in the up-regulation of matrix metalloproteinase-1 expression. These results suggest that the discoidin-related DDR tyrosine kinases are novel collagen receptors with the potential to control cellular responses to the extracellular matrix.

Amino Acid Sequence↗
PubMed1997

Zoo-FISH analysis: the American mink (Mustela vison) closely resembles the cat karyotype.

The 24 human chromosome-specific DNA probes were used to visualize segments of conserved synteny on metaphase chromosomes of the American mink (Mustela vison). A comparison with the hitherto known gene mapping data shows a high degree of correspondence. The human chromosomes were found conserved in only 34 segments of common synteny. The mink arrangement proved to be very similar to the arrangement found in the cat, thus corroborating the well-known high karyotype conservation described for Feloidea.

Animals↗
PubMed1997

[Carving].

Using skis with a deep sidecut (as carving skis have it) it's not necessary to learn a new techniques. Different carving skis are developed for all target groups. They simplify the steering of turns on the ski-edge, but the skier needs some more muscle-effort as with usual skis. Lately physical researches proved that there's no higher risk of false cutting with carving skis than with common, normal sidecut skis. Mainly the condition of the ski-edge and the height of the skier's position over the ski do cause false cutting.

Acceleration↗
PubMed1997

Characterization of FMR1 promoter elements by in vivo-footprinting analysis.

Fragile X syndrome is associated with silencing of the FMR1 gene. We studied the transcriptional regulation, by analysis of the FMR1 promoter region for the presence of in vivo protein/DNA interactions and for cytosine methylation at the single-nucleotide level. Four protein-binding sites were present in the unmethylated promoter of the active FMR1 gene. In the methylated promoter of inactive genes no footprints were detected, and no evidence of active repression was found in the region investigated. We propose that the silencing of FMR1 gene transcription results from a lack of transcription-factor binding.

Adult↗
PubMed1997

Blocking mechanisms of ketamine and its enantiomers in enzymatically demyelinated peripheral nerve as revealed by single-channel experiments.

BACKGROUND: Ketamine shows, besides its general anesthetic effect, a local anesthetic-like action that is due to blocking of peripheral nerve sodium currents. In this study, the stereoselectivity of the blocking effects of the ketamine enantiomers S(+) and R(-) was investigated in sodium and potassium channels in peripheral nerve membranes. METHODS: Ion channel blockade of ketamine was investigated in enzymatically dissociated Xenopus sciatic nerves in multiple-channel and in single-channel outside-out patches. RESULTS: Concentration-effect curves for the Na+ peak current revealed half-maximal inhibiting concentrations (IC50) of 347 microM and 291 microM for S(+) and R(-) ketamine, respectively. The potential-dependent K+ current was less sensitive than the Na+ current with IC50 values of 982 microM and 942 microM. The most sensitive ion channel was the flickering background K+ channel, with IC50 values of 168 microM and 146 microM for S(+) and R(-) ketamine. Competition experiments suggest one binding site at the flicker K+ channel, with specific binding affinities for each of the enantiomers. For the Na+ channel, the block was weaker in acidic (pH = 6.6) than in neutral (pH = 7.4) and basic (pH = 8.2) solutions; for the flicker K+ channel, the block was weaker in acidic and stronger in basic solutions. CONCLUSIONS: Ketamine blockade of sodium and potassium channels in peripheral nerve membranes shows no stereoselectivity except for the flicker K+ channel, which showed a very weak stereoselectivity in favor of the R(-) form. This potential-insensitive flicker K+ channel may contribute to the resting potential. Block of this channel and subsequent depolarization of the resting membrane potential leads, besides to direct Na+ channel block, to inexcitability via Na+ channel inactivation.

Anesthetics, Dissociative↗
PubMed1997

Functional characterization of the human biglycan 5'-flanking DNA and binding of the transcription factor c-Krox.

The transcriptional regulation of human biglycan expression under normal and pathological conditions was studied. The 5'-flanking regions of the human and mouse genes were isolated and analyzed; the two promoter regions share 81% identity. Both promoters are without a TATA and CAT box and contain multiple Sp1 sites. Human dermal fibroblasts were transiently transfected with progressive deletional human biglycan 5'-flanking DNA-CAT constructs, and a significant variation in activity among the individual constructs was found. A small deletion in several cases caused a more than 2-fold increase or decrease in promoter activity, thereby mapping the target sites for repressors or activators. Human biglycan expression is reduced in females with Ullrich-Turner syndrome (45,X) and increased in individuals with supernumerary sex chromosomes, and it has been speculated that biglycan plays a role in the short stature phenotype of Turner syndrome. Analysis of the transcriptional regulation of biglycan in individuals with sex chromosome anomalies showed that a -262 to -218 region of the biglycan promoter was differentially regulated. This region was extensively analyzed by DNAse footprinting and electrophoretic mobility shift assays, and a putative binding site for the transcription factor c-Krox was discovered. The binding of c-Krox to a site located at approximately -248 to -230 in the human biglycan promoter was confirmed by using extracts from COS cells expressing recombinant human c-Krox. The expression of c-Krox in bone was then examined by reverse-transcribed polymerase chain reaction and Northern blotting analysis; an approximately 3.4 kb transcript was detected in primary osteoblastic cells, in MG-63 cells, and in human bone marrow stromal cells. This is the first detection of c-Krox in bone cells, and it suggests that c-Krox, like another member of the Krox family, Krox-20, might play a regulatory role in bone.

Animals↗
PubMed1997

Endogenous production of methanol after the consumption of fruit.

After the consumption of fruit, the concentration of methanol in the human body increases by as much as an order of magnitude. This is due to the degradation of natural pectin (which is esterified with methyl alcohol) in the human colon. In vivo tests performed by means of proton-transfer-reaction mass spectrometry show that consumed pectin in either a pure form (10 to 15 g) or a natural form (in 1 kg of apples) induces a significant increase of methanol in the breath (and by inference in the blood) of humans. The amount generated from pectin (0.4 to 1.4 g) is approximately equivalent to the total daily endogenous production (measured to be 0.3 to 0.6 g/day) or that obtained from 0.3 liters of 80-proof brandy (calculated to be 0.5 g). This dietary pectin may contribute to the development of nonalcoholic cirrhosis of the liver.

Acetone↗
PubMed1997

Gastric antral vascular ectasia with portal hypertension: treatment with TIPSS.

Gastric antral vascular ectasia, or "watermelon stomach," is a distinct clinical entity within the spectrum of upper gastrointestinal mucosal vascular abnormalities. The pathobiology of the disease is unclear. We here describe a case that emphasizes the importance of the "watermelon stomach" as differential diagnosis of occult gastrointestinal blood loss and report on its successful treatment through installation of a transjugular intrahepatic portosystemic stent shunt (TIPSS).

Aged↗
PubMed1996

Properties and functions of Na(+)-activated K+ channels in the soma of rat motoneurones.

1. Properties and functions of Na(+)-activated K+ (KNa) channels in the soma of motoneurones were studied in spinal cord slices of newborn rat. KNa channels had a conductance of 44.8 pS in 5.6 mM external K+ (Ko+)/106 mM internal K+ (Ki+) solutions and 139.2 pS in 155 mM Ko+/85 mM Ki+ solutions. KNa channels were voltage independent and needed a relatively high [Na+]i to become active (EC50 = 39.9 mM). Li+ could not substitute for Na+ in activation of KNa channels. The channels were predominantly found in the vicinity of cell processes, in the regions of most probable accumulation of cytoplasmic Na+. 2. In current-clamp experiments, the shape of the single action potential (AP) recorded in Ca(2+)-free Ringer solution was not changed after substitution of external Na+ with Li+. However, 0.4-0.8 s trains of APs were followed by a slow (1-2s) after-hyperpolarization (sAHP), which reversibly disappeared when external Na+ was replaced by Li+. Na(+)-activated sAHP persisted after addition of ouabain and its amplitude was even increased in K(+)-free Ringer solution. sAHP disappeared when the membrane potential was equal to the K+ equilibrium potential. This indicated that sAHP resulted from activation of a Na(+)-dependent K+ conductance, rather than from activation of the electrogenic Na(+)-K+ pump. 3. In conclusion, KNa channels can play an important role in excitability of motoneurones. KNa channels do not make a contribution to the single AP, but they can be activated by a local accumulation of internal Na+ during trains of APs. A Na(+)-activated K+ conductance can reduce membrane excitability and contribute to regulation of AP firing in motoneurones.

Animals↗
PubMed1996

Therapy of primary biliary cirrhosis with p-tolylmethylcarbinol nicotinic acid ester in combination with alpha-naphthylacetic acid.

OBJECTIVE: To assess the effect of choleretic treatment with p tolylmethylcarbinol nicotinic acid ester and alpha-naphthylacetic acid (Galle-Donau) on laboratory parameters of cholestasis, lipids, immunologic activity and on clinical signs in primary biliary cirrhosis patients. DESIGN: Prospective, non-randomized case control study; retrospective evaluation of pre-treatment period, evaluation of six months of treatment, open study after six month of treatment with evaluation of patients further treated and patients who discontinued treatment. PATIENTS AND METHODS: Twelve consecutive patients with proven primary biliary cirrhosis, all female. Patients were to take six to nine capsules of Galle-Donau, containing 37.5 mg p-tolymethylcarbinol nicotinic acid ester and 75 mg alpha-naphthylacetic acid (5 mg per kg of body weight and 10 mg), daily in three doses, together with meals. Six patients discontinued treatment with Galle-Donau after six months and were followed up further. RESULTS: After six months of Galle-Donau treatment the average alkaline phosphatase level dropped from 670.8 IU/ml to 577.1 IU/ml; the levels of total bilirubin (1.46 vs. 1.15 mg/100 ml) and unconjugated bilirubin (0.82 vs. 0.63 mg/100 ml) also decreased under therapy. This drop was not significant, while the decrease in triglycerides (149.2 vs. 103.1 mg/100 ml) reached statistical significance. During further treatment for up to two years patients showed no significant change in triglycerides, cholesterol or alkaline phosphatase. y-Glutamyl transpeptidase was not changed by treatment. Discontinuance of treatment resulted in significant increases in alkaline phosphatase and y-glutamyl transpeptidase, as well as in bilirubin levels. Triglyceride values also rose significantly when treatment was stopped, while the increase in cholesterol did not reach statistical significance. No influence of Galle-Donau treatment was found on IgM level. Pruritus (five patients) and Sicca symptoms (six patients) resolved within the treatment period in all but one patient (Sicca symptoms) who did not take the medication regularly. In the group of patients who discontinued therapy pruritus returned in both patients who had complained of it before therapy. Sicca symptoms returned in one out of three patients. CONCLUSION: Treatment with p-tolylmethylcarbinol nicotinic acid ester and alpha-naphthylacetic acid leads to relief of symptoms and ameliorates biochemical parameters of cholestasis may, therefore, be of value for PBC therapy.

Adult↗
PubMed1996

Divergent effects of alpha 1-antitrypsin on the regulation of iron metabolism in human erythroleukaemic (K562) and myelomonocytic (THP-1) cells.

The acute-phase protein alpha 1-antitrypsin (alpha 1-AT) has been shown to inhibit the binding of transferrin to its cell-surface receptor. Here we demonstrate that in human erythroleukaemic cells (K562) alpha 1-AT enhances the binding affinity of iron-regulatory protein (IRP), the central regulator of cellular iron metabolism, to iron-responsive elements. Activation of IRP by alpha 1-AT is associated with a marked increase in transferrin receptor (trf-rec) mRNA levels in K562 and enhanced cell-surface expression of transferrin-binding sites, whereas ferritin production is decreased, although ferritin mRNA levels remain unchanged. In agreement with the well-established mechanism of cellular iron regulation, alpha 1-AT seems to modulate trf-rec and ferritin expression primarily post-transcriptionally/translationally by influencing IRP activity. In contrast, alpha 1-AT produces only minor changes in IRP activity, and subsequently in trf-rec expression and ferritin synthesis in THP-1 cells. Moreover the effects of alpha 1-AT on iron homeostasis in K562 cannot be overcome by the addition of iron salts, whereas concomitant treatment of THP-1 with iron and alpha 1-AT results in the same metabolic changes as the addition of iron alone. Because alpha 1-AT blocks transferrin binding on K562 as well as on THP-1 cells, it is suggested, on the basis of the results presented here, (1) that erythroid and monocytic cells might differ in their dependence on transferrin-mediated iron supply and (2) that THP-1 might be able to acquire iron by a transferrin-independent iron uptake system. alpha 1-AT might therefore be involved in the diversion of iron traffic between various cellular compartments under inflammatory conditions.

Cell Line↗
PubMed1996

Ex vivo expansion of CD34+ peripheral blood progenitor cells: implications for the expansion of contaminating epithelial tumor cells.

Cytokine-supported ex vivo expansion of peripheral blood progenitor cells (PBPCs) offers new perspectives for autografting after high-dose chemotherapy. One of the potential advantages is the possibility to reduce the volume of blood processed from the patient, thus allowing reduction of the overall tumor cell number in the final autograft. However, ex vivo expansion will only be advantageous if contaminating tumor cells are not expanded concomitantly. This question has not previously been addressed. Therefore, we analyzed unseparated PBPC preparations, CD34(+)-selected cell fractions, and ex vivo-expanded cell preparations from stage IV (n = 16) and high-risk stage II/III (n = 8) breast cancer patients for the presence of human epithelial antigen- (HEA) or cytokeratin (CK)-positive tumor cells. We found that three of 16 (18.8%) of the unseparated PBPC products from stage IV patients were HEA- and/or CK-positive, whereas none of the stage II/III patients were found to be positive after two cycles of induction chemotherapy with etoposide (VP16), ifosfamide, cisplatin, and epirubicin (VIP-E). After CD34+ cell selection (Ceprate SC; CellPro, Bothell, WA) and stem-cell factor (SCF), interleukin (IL)-1, IL-3, IL-6, and erythropoietin (EPO)-mediated ex vivo expansion of the CD34+ cells for 14 to 21 days, no tumor cells could be detected in these primary breast cancer patients at a sensitivity of 1 tumor cell per 4 x 10(5) nucleated cells. Thus, to answer the question of whether tumor cells are expanded concomitantly on ex vivo expansion of normal CD34+ cells, we cocultured defined numbers of primary renal carcinoma cells (RS-85), xenograft-derived breast cancer cells, and small-cell lung cancer cells with CD34+ cells selected from normal donors or cancer patients, either in serum or serum-free culture media. We found that none of the three epithelial tumor cell types increased significantly in number during a 14-day coculture period when compared with normal CD34+ cells alone or tumor cells alone, which increased 110- +/- 77-fold and 45- +/- 26-fold, respectively. However, during coculture, the tumor cells did not undergo cell death and were able to regrow when maintained in serum for longer time periods. We conclude that cytokine-supported expansion cultures of positively selected CD34+ PBPCs from primary high-risk stage II/III or stage IV breast cancer patients do not contain detectable tumor cells, which suggests that there is no increased risk of concomitantly expanding tumor cells. Moreover, cocultures of exogenously mixed tumor cell lines with normal CD34+ cells showed a relative disadvantage of tumor cell growth compared with the growth of hematopoietic cells, again without an apparent risk of concomitantly expanding tumor cells. However, considering the pronounced heterogeneity of tumor cell kinetics, ex vivo-expanded PBPC from cancer patients should be monitored for minimal residual disease.

Animals↗