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GP SCHWAB AL BLUM E BODNER B DALLEMAGNE K GLASER H KOOP F PACE W RÖSCH JR SIEWERT G WETSCHER 《Journal of gastroenterology and hepatology》1997,12(12):785-789
Gastroesophageal reflux disease (GERD) is the most common disease of the upper gastrointestinal tract. With the introduction of proton pump inhibitors medical treatment of GERD has been significantly improved. However, the development of laparoscopic antireflux surgery resulted in an increasing interest of surgeons in this disease. An interactive meeting was organized in order to develop an agreement between gastoenterologists and surgeons regarding therapeutic decisions and this is the main topic of this paper. 相似文献
4.
Low-artifact intravascular devices: MR imaging evaluation 总被引:2,自引:0,他引:2
Teitelbaum GP; Ortega HV; Vinitski S; Stern H; Tsuruda JS; Mitchell DG; Rifkin MD; Bradley WG Jr 《Radiology》1988,168(3):713-719
Flow-phantom magnetic resonance (MR) imaging, with use of both spin-echo (SE) and gradient-echo (GRE) techniques at 1.5 T, was performed on the percutaneous Greenfield (beta-III titanium alloy [TMA wire]), Amplatz (MP32-N alloy), and Simon nitinol filters and TMA wire facsimiles of the bird's nest, Gunther, new retrievable, and Amplatz vena caval filters. SE imaging allowed detection of thrombi as small as 5 X 5 mm trapped within the percutaneous Greenfield, Simon nitinol, and TMA-wire facsimile filters; with the MP32-N Amplatz filter, a larger volume of thrombus (10 X 20-mm clots) was necessary for clot detection. GRE imaging allowed detection of intraluminal tilting of the percutaneous Greenfield and facsimile Amplatz (TMA-wire) filters. GRE imaging was useful for demonstrating postfilter turbulence due to clots, which was greatest for the Amplatz filter. Imaging of facsimile vascular devices made of tantalum or TMA wire did not cause the severe "black-hole" MR artifacts typical of the stainless-steel devices. SE and GRE imaging were very useful for determining caval patency in two patients with previously placed Mobin-Uddin filters. Noninvasive MR evaluation of blood vessels in the presence of a variety of low-artifact intravascular devices appears feasible. 相似文献
5.
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Sequence comparison of human and yeast telomeres identifies structurally distinct subtelomeric domains 总被引:6,自引:2,他引:6
Flint J; Bates GP; Clark K; Dorman A; Willingham D; Roe BA; Micklem G; Higgs DR; Louis EJ 《Human molecular genetics》1997,6(8):1305-1313
We have sequenced and compared DNA from the ends of three human
chromosomes: 4p, 16p and 22q. In all cases the pro-terminal regions are
subdivided by degenerate (TTAGGG)n repeats into distal and proximal sub-
domains with entirely different patterns of homology to other chromosome
ends. The distal regions contain numerous, short (<2 kb) segments of
interrupted homology to many other human telomeric regions. The proximal
regions show much longer (approximately 10-40 kb) uninterrupted homology to
a few chromosome ends. A comparison of all yeast subtelomeric regions
indicates that they too are subdivided by degenerate TTAGGG repeats into
distal and proximal sub-domains with similarly different patterns of
identity to other non-homologous chromosome ends. Sequence comparisons
indicate that the distal and proximal sub-domains do not interact with each
other and that they interact quite differently with the corresponding
regions on other, non- homologous, chromosomes. These findings suggest that
the degenerate TTAGGG repeats identify a previously unrecognized,
evolutionarily conserved boundary between remarkably different subtelomeric
domains.
相似文献
7.
Gao J Gross J Andreeva N Glatzel E Grützmann H Heldt J Husemann B Jamielson L Andersson K 《Journal of neural transmission (Vienna, Austria : 1996)》1999,106(2):111-122
Summary. Perinatal hypoxia is known as a high risk factor for the development of long-lasting abnormalities in dopaminergic system.
The early developmental alterations of dopamine (DA) metabolism induced by hypoxia could contribute to these abnormalities.
To understand the hypoxia-induced changes of intra- and extracellular dopamine levels and its main metabolites, 3,4-dihydroxyphenylacetic
acid (DOPAC) and homovanillic acid (HVA), in immature dopaminergic neurons, we compared these changes in rat mesencephalic
and diencephalic cell cultures on day in vitro (DIV) 2 (immature cells), DIV 8 and DIV 13 (mature cells). Cell cultures were
exposed to an oxygen-free gas mixture in a Billups chamber for 2–4 hours. Mature cell cultures responded to hypoxia with an
increase of DA levels in the cells and in the medium during the first 45 min (by an average of 57 and 114% respectively).
Thereafter, DA levels decreased, and returned to the baseline within the next 30 min. The cellular DA levels continued to
decrease up to 15% of the baseline during 255 min hypoxia whereas the extracellular DA content stabilized at the prehypoxic
levels. Immature cell cultures (DIV 2) in contrast to mature ones, were unable to maintain normal extracellular DA levels
during hypoxia and showed a decrease of the cellular and extracellular levels to 50% of the prehypoxic levels. DOPAC and HVA
changes mimick, however, at a lower level, the pattern of DA changes during the exposure to hypoxia. In principle, in the
diencephalic cell culture similar effects of hypoxia exposure on the investigated parameters were found (studied during 0–120
min).
The present study demonstrates that mature and immature dopaminergic cells differ in the regulation of the extra- and intracellular
DA levels during hypoxia. In immature cells the low synthetic capacity of tyrosine hydroxylase and the deficient capacities
of the transport and storage processes result in decreased extracellular DA levels. This could be an important factor for
the long-term modulation of the expression of tyrosine hydroxylase and subsequent long-term behavioral and/or neurological
abnormalities induced by perinatal hypoxia.
Received June 8, 1998; accepted July 21, 1998 相似文献
8.
Abril N; Luque-Romero FL; Prieto-Alamo MJ; Rafferty JA; Margison GP; Pueyo C 《Carcinogenesis》1997,18(10):1883-1888
Here we confirm and extend our previous studies demonstrating that the
mutagenic potency of 1,2-dibromoethane (DBE) and dibromomethane (DBM) is
markedly enhanced (not prevented) in bacteria expressing the O6-
alkylguanine-DNA alkyltransferase (ATase) encoded by the Escherichia coli
ogt gene. We demonstrate that, in close parallel with mutagenesis, the Ogt
ATase sensitizes the bacteria to the lethal effects of these carcinogens,
suggesting that one or more of the potentially mutagenic lesions induced by
DBE and DBM in the presence of Ogt has additional lethal capacity. We
further demonstrate that the sensitization to both lethality and
mutagenesis by DBE and DBM is a property shared by other DNA
alkyltransferases. This objective was accomplished by quantifying the
induction of mutations and lethal events in ogt- ada- E. coli expressing an
exogenous bacterial or mammalian ATase from a multicopy plasmid. Mammalian
recombinant ATases enhanced the lethal and mutagenic actions of DBE and
suppressed the lack of sensitivity of the vector- transformed bacteria to
DBM. In most cases the order of effectiveness of the ATases ranked: murine
> human > Ogt > rat. Further comparisons included the full-length
Ada ATase from E. coli and a truncated Ada version (T-ada) that retains the
O6-methylguanine binding domain of the protein. The full-length Ada ATase
was effective in enhancing the lethality but not the mutagenicity induced
by DBE and DBM. The T-ada ATase provided less sensitization than Ada to
lethality by DBE, but of the three bacterial ATases T-ada yielded the
highest sensitization to mutagenesis by this compound. T-ada and Ada ATases
were in general less effective than the mammalian versions, with the
exception of the rat recombinant ATase. The effectiveness of the different
mammalian and bacterial ATases in promoting the deleterious actions of
dibromoalkanes was compared with the effectiveness of these proteins in
suppressing the lethal and mutagenic effects induced by
N-nitroso-N-methylurea. The ability to sensitize E. coli to the lethal and
mutagenic effects of DBE and DBM seems restricted to DNA alkyltransferase,
since overexpression of thioredoxin (Trx) or glutaredoxin (Grx1) in ogt-
ada- cells showed no effect, in spite of the reported potential of
bioactive dihaloethane- derived species to alkylate Trx.
相似文献
9.
Recent postmortem studies in humans suggest that defects in GABAergic neurotransmission might contribute to the neuropathology associated with schizophrenia. Disturbances in GABAergic systems may also contribute to the sensorimotor gating deficits classically observed in schizophrenic patients, including deficits in prepulse inhibition (PPI). To explore the relationship, the current study examined the integrity of PPI and startle habituation in knockout (KO) mice that lack the GABA synthesizing enzyme glutamic acid decarboxylase 65 (GAD 65). GAD65 KO mice displayed normal baseline and habituated startle responses, which did not differ from GAD65 wild-type (WT) or heterozygous (HET) mice. However, GAD65 KO mice showed robust deficits in PPI which were reversed by the atypical antipsychotic agent clozapine. These results lend support to the view that abnormalities in GABAergic systems might contribute to the basic pathophysiological mechanisms in schizophrenia. 相似文献
10.