julilili42/papers huggingface dataset:
The Cardiac Fas (APO-1/CD95) Receptor/Fas Ligand System
2000-03-14

Background —Fas (APO-1/CD95) is a transmembrane receptor belonging to the tumor necrosis factor receptor superfamily. Cross-linking of Fas by Fas ligand (FasL), a tumor necrosis factor-α–related cytokine, promotes apoptosis and/or transcription factor activation in a highly cell-type–specific manner. The biological consequences of Fas activation in cardiomyocytes and the regulation of Fas and FasL abundance in the myocardium in vivo remain largely unknown. Methods and Results —As shown by immunohistochemistry, Fas was expressed on the sarcolemma of cardiomyocytes in left ventricular tissue sections. Moreover, FasL was constitutively expressed in the myocardium and in isolated cardiomyocytes, as revealed by reverse transcription polymerase chain reaction and Western blotting. Left ventricular abundance of Fas but not FasL was upregulated in a rat model of compensated volume-overload hypertrophy and was closely related to diastolic but not systolic wall stress as determined by MRI. Cardiomyocyte apoptosis was not enhanced in volume-overload hypertrophy despite the increased expression of Fas and the presence of FasL in the myocardium. Moreover, injection of mice with an agonistic anti-Fas antibody promoted hepatocyte but not cardiomyocyte apoptosis in vivo. Stimulation of isolated cardiomyocytes with recombinant FasL promoted an activation of the transcription factor AP-1 as shown by electrophoretic mobility shift assays but did not induce cell death. Conclusions —Fas and FasL are constitutively expressed in the myocardium and in cardiomyocytes. Myocardial expression of Fas is closely related to diastolic loading conditions in vivo. Signaling pathways emanating from Fas are coupled to an activation of the transcription factor AP-1 in cardiomyocytes.
Neutral amino acid transporter ASCT2 displays substrate-induced Na+ exchange and a substrate-gated anion conductance
2000-03-15

The neutral amino acid transporter ASCT2 mediates electroneutral obligatory antiport but at the same time requires Na+ for its function. To elucidate the mechanism, ASCT2 was expressed in Xenopus laevis oocytes and transport was analysed by flux studies and two-electrode voltage clamp recordings. Flux studies with 22NaCl indicated that the uptake of one molecule of glutamine or alanine is accompanied by the uptake of four to seven Na+ ions. Similarly to the transport of amino acids, the Na+ uptake was mediated by an obligatory Na+ exchange mechanism that depended on the presence of amino acids but was not stoichiometrically coupled to the amino acid transport. Other cations could not replace Na+ in this transport mechanism. When NaCl was replaced by NaSCN in the transport buffer, the superfusion of oocytes with amino acid substrates resulted in large inward currents, indicating the presence of a substrate-gated anion channel in the ASCT2 transporter. The Km for glutamine derived from these experiments is in good agreement with the Km derived from flux studies; it varied between 40 and 90 μM at holding potentials of -60 and -20 mV respectively. The permeability of the substrate-gated anion conductance decreased in the order SCN- NO3- > I- > Cl- and also required the presence of Na+.
Morphological changes of the human gastric mucosa under long-term proton pump inhibitor therapy and their clinical relevance
2000-03-15

Proton pump inhibitors are potent drugs for the treatment of acid-related diseases. The moderate hypergastrinaemia observed during therapy is a physiological response to low intragastric pH and the increase is limited to the first months of therapy with no further changes thereafter. Reports on endocrine cell changes in the antral mucosa under chronic PPI therapy are controversial and lack clinical relevance. In contrast, in the oxyntic mucosa hyperplastic argyrophil cell changes have been reported, dependent on the degree and duration of hypergastrinaemia, the severity of oxyntic mucosal gastritis, especially atrophy, and the presence of H. pylori infection. Current data do not support a progression from hyperplastic to dysplastic argyrophil cell lesions in humans in the absence of additional genetic factors. Data on the progression of oxyntic gastritis under chronic PPI treatment in comparison to untreated controls could not be confirmed in more recent studies including a well-matched control population. The main factor for gastritis progression is the presence of Helicobacter pylori infection. The bacterium not only causes a chronic inflammation of the gastric mucosa, resulting in atrophy and intestinal metaplasia, but also influences endocrine cell populations involved in the regulation of gastric acid secretion. The clinical benefit of H. pylori eradication in reflux esophagitis patients is still a matter of debate. The complex relations in humans between hypergastrinaemia, (oxyntic) gastritis and atrophy, H. pylori infection, argyrophil cell hyperplasia, and the effects of long-term PPI treatment of acid-related diseases do not allow a quantification of the contribution of each single factor for the observed changes.
Quasiparticle random phase approximation with inclusion of the Pauli exclusion principle
2000-03-15

Limitations of the Quasiparticle Random Phase Approximation (QRPA) are\\nstudied within an exactly solvable model, with a two body interaction of Fermi\\ntype. A special attention is paid to the violation of the Pauli exclusion\\nprinciple (PEP) in solving the QRPA equation. A comparison of the exact\\nsolution, obtained by the diagonalization of a schematic nuclear Hamiltonian\\nand those obtained within the standard QRPA, the renormalized QRPA, the QRPA\\nwith pertubative treatment of the PEP and the QRPA with exact consideration of\\nthe PEP, is presented. The agreement quality is judged in terms of the\\nquasiparticle number operator matrix elements in the ground state and in the\\nfirst excited states, of the beta transition amplitudes, of the Ikeda sum rule\\nand of the nuclear matrix element for the double beta decay. We have found that\\nrestoring the PEP, the QRPA solutions are considerably stabilized and a better\\nagreement with the exact solution is obtained.\\n
Morphological changes of the human gastric mucosa under long-term proton pump inhibitor therapy and their clinical relevance
2000-03-15

Proton pump inhibitors are potent drugs for the treatment of acid-related diseases. The moderate hypergastrinaemia observed during therapy is a physiological response to low intragastric pH and the increase is limited to the first months of therapy with no further changes thereafter. Reports on endocrine cell changes in the antral mucosa under chronic PPI therapy are controversial and lack clinical relevance. In contrast, in the oxyntic mucosa hyperplastic argyrophil cell changes have been reported, dependent on the degree and duration of hypergastrinaemia, the severity of oxyntic mucosal gastritis, especially atrophy, and the presence of H. pylori infection. Current data do not support a progression from hyperplastic to dysplastic argyrophil cell lesions in humans in the absence of additional genetic factors. Data on the progression of oxyntic gastritis under chronic PPI treatment in comparison to untreated controls could not be confirmed in more recent studies including a well-matched control population. The main factor for gastritis progression is the presence of Helicobacter pylori infection. The bacterium not only causes a chronic inflammation of the gastric mucosa, resulting in atrophy and intestinal metaplasia, but also influences endocrine cell populations involved in the regulation of gastric acid secretion. The clinical benefit of H. pylori eradication in reflux esophagitis patients is still a matter of debate. The complex relations in humans between hypergastrinaemia, (oxyntic) gastritis and atrophy, H. pylori infection, argyrophil cell hyperplasia, and the effects of long-term PPI treatment of acid-related diseases do not allow a quantification of the contribution of each single factor for the observed changes. Microsc. Res. Tech. 48:357–366, 2000. © 2000 Wiley-Liss, Inc.
Integrating Combinatorial Synthesis and Bioassays
2000-03-17

The increasing demand for large chemical libraries of potential drug candidates is accompanied by the need for efficient methods for identifying biologically active compounds in these libraries. In this TechView, Rademann and Jung (p. 1947) discuss strategies for creating efficient interfaces between combinatorial synthesis and screening and hereby extracting biologically relevant information from libraries of chemical compounds.
Three-year-old girl with partial trisomy 4p and partial monosomy 8p with resemblance to Brachmann-de Lange syndrome?another locus for Brachmann-de Lange syndrome on 4p?
2000-03-20

We describe a 3-year-old girl with partial trisomy 4p and partial monosomy 8p who had prenatal and postnatal growth retardation, mental retardation, no speech development, mild synophrys, hirsutism, apparently low-set ears, dysphonic hoarse voice, hyperactivity, and small hands with proximal placement of the thumbs. She had recurrent lung infections, due to earlier aspiration and immune deficiency (chronic granulomatous disease). Cytogenetic findings in this and other cases with suggestive phenotype may point to an additional locus for Brachmann-de Lange phenotype.
Irradiation induced clonogenic cell death of human malignant glioma cells does not require CD95/CD95L interactions.
2000-03-23

We conclude that endogenous CD95/CD95L interactions are not involved in radiation-induced clonogenic cell death and that the killing cascades of CD95L and irradiation are independent in human malignant glioma cells.
QED effective action at finite temperature: Two-loop dominance
2000-03-27

We calculate the two-loop effective action of QED for arbitrary constant\\nelectromagnetic fields at finite temperature T in the limit of T much smaller\\nthan the electron mass. It is shown that in this regime the two-loop\\ncontribution always exceeds the influence of the one-loop part due to the\\nthermal excitation of the internal photon. As an application, we study light\\npropagation and photon splitting in the presence of a magnetic background field\\nat low temperature. We furthermore discover a thermally induced contribution to\\npair production in electric fields.\\n
Expression and functional activity of heat shock proteins in human glioblastoma multiforme
2000-03-28

High constitutive, as opposed to inducible, expression of HSP may play a role in the primary resistance of human malignant gliomas to cytotoxic radiochemotherapy. Superinduction of HSP levels by hyperthermia in vitro provided no further survival advantage.
ChemInform Abstract: Synthesis and Structure of Ammine and Amido Complexes Iridium.
2000-03-28

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Neuroprotection by the Inhibition of Apoptosis
2000-04-01

Accumulating evidence strongly suggests that apoptosis contributes to neuronal cell death in a variety of neurodegenerative contexts. Activation of the cysteine protease caspase‐3 appears to be a key event in the execution of apoptosis in the central nervous system (CNS). As a result, mice null for caspase‐3 display considerable neuronal expansion usually resulting in death by the second week of life. At present, 14 caspase family members have been identified and subdivided into three subgroups on the basis of preference for specific tetrapeptide motifs using a positional scanning combinatorial substrate library. Caspase‐3 is a group II member (2, 3, 7) categorized by an absolute substrate requirement for aspartic acid in the P 4 position of the scissile bond. The preferred cleavage motif (DExD) for group II caspases is found in many structural, metabolic and repair proteins essential for cellular homeostasis. Consistent with the proposal that apoptosis plays a central in role human neurodegenerative disease, caspase‐3 activation has recently been observed in stroke, spinal cord trauma, head injury and Alzheimer's disease. Indeed, peptide‐based caspase inhibitors prevent neuronal loss in animal models of head injury and stroke suggesting that these compounds may be the forerunners of non‐peptide small molecules that halt apoptosis processes implicated in these neurodegenerative disorders. A clear link between an hereditary neurodegenerative disorder and failed caspase inhibition has recently been proposed for spinal muscular atrophy (SMA). In severe SMA, the neuronal specific inhibitor of apoptosis (IAP) family member known as NAIP is often dysfunctional due to missense and truncation mutations. IAPs such as NAIP potently block the enzymatic activity of group II caspases (3 and 7) suggesting that NAIP mutations may permit unopposed developmental apoptosis to occur in sensory and motor systems resulting in lethal muscular atrophy. Conversely, adenovirally‐mediated overexpression of NAIP or the X‐linked IAP called XIAP reduces the loss of CA1 hippocampal neurons following transient forebrain ischemia. Taken together, these findings suggest that anti‐apoptotic strategies may some day have utility in the treatment of neurodegenerative disease. The present review will summarize some of the recent evidence suggesting that apoptosis inhibitors may become a practical therapeutic approach for both acute and chronic neurodegenerative conditions.
Valproate as an Adjunct to Neuroleptic Medication for the Treatment of Acute Episodes of Mania: A Prospective, Randomized, Double-Blind, Placebo-Controlled, Multicenter Study
2000-04-01

To compare the efficacy of sodium valproate administered as adjunct to neuroleptic medication for patients with acute mania with the efficacy of neuroleptics alone, the authors conducted a 21-day, randomized, double-blind, parallel-group, placebo-controlled trial. The study design closely reflected a clinical psychiatric setting in Europe where patients with acute mania commonly receive neuroleptic medication. In this trial, 136 hospitalized patients met the ICD-10 criteria for acute manic episodes; these patients received a fixed dose of 20 mg/kg of body weight of sodium valproate (Orfiril, Desitin Arzneimittel GmbH, Hamburg, Germany) orally, in addition to basic neuroleptic medication, preferably haloperidol and/or perazine. The primary outcome measure was the mean dose of neuroleptic medication (after conversion into haloperidol-equivalents) for the 21-day study period. Severity of symptoms was measured using the Young Mania Rating Scale (YMRS), the Global Assessment Scale, and the Clinical Global Impression Scale. Intent-to-treat analysis was based on 69 patients treated with valproate and 67 patients who received placebo. Groups were comparable with regard to demographic and clinical baseline data. Premature discontinuations occurred in only 13% of the patients. The mean neuroleptic dose declined continuously in the valproate group, whereas only slight variations were observed in the placebo group; the difference was statistically significant (p = 0.0007) for study weeks 2 and 3. The combination of neuroleptic and valproate proved superior to neuroleptics in attempts to alleviate manic symptoms. The proportion of responders (a 50% improvement rate shown on the YMRS) was higher for the combination with valproate than for the group receiving only neuroleptics (70% vs. 46%; p = 0.005). Adverse events consisted of those known for valproate or neuroleptics; the only adverse event was asthenia, which occurred more frequently with the combination therapy. Valproate represents a useful adjunct medication for the treatment of acute manic symptoms. Valproate is beneficial because it allows the administration of fewer neuroleptic medications and produces improved and quicker remission of manic symptoms.
Prognostic impact of the type of anaesthesia used during the excision of primary cutaneous melanoma
2000-04-01

The prognostic value of the type of anaesthesia used for the excision of malignant tumours has been a subject of controversy. Cell-mediated as well as humoral immune responses can be compromised after general anaesthesia, and recurrences may therefore occur more frequently. On the other hand, excision of primary tumours under local anaesthesia might also influence the prognosis unfavourably. The aim of the present study was to determine the prognostic impact of general and local anaesthesia for the primary excision of cutaneous melanoma. Follow-up data of 4329 patients on the Central Melanoma Registry of the German Dermatological Society were analysed. Cox proportional hazards analysis was performed to evaluate the independent significance of the prognostic factors, and survival probabilities were calculated for matched pairs using Kaplan-Meier estimates. Statistical analysis revealed an independent significant effect on survival for tumour thickness, ulceration, level of invasion, anatomical site and gender. General anaesthesia for primary excision of melanoma was associated with a decrease in the survival rate (relative risk 1.46, P<0.0001). This study revealed a slight but significantly increased risk of death for patients treated with general anaesthesia for the primary excision of melanoma. Therefore local anaesthesia should be preferred for the treatment of primary melanoma.
Is morphoea caused by Borrelia burgdorferi? A review
2000-04-01

The aetiology of morphoea and lichen sclerosus et atrophicus is still unknown. Since the detection of Borrelia burgdorferi (B. burgdorferi) as the causative agent of Lyme disease, there has been debate about a possible association between B. burgdorferi and morphoea. Initial serological and cultural studies showed controversial results. The introduction of polymerase chain reaction (PCR) initially suggested an association between B. burgdorferi and morphoea. We reviewed the literature on B. burgdorferi (specific serology, immunohistology, culture, lymphocyte stimulation and DNA detection by PCR) since 1983, using Medline and Current Contents. Histological and immunohistological detection of B. burgdorferi was reported in 0-40% (20 of 82) of the cases with morphoea and in 46-50% (17 of 36) of the cases with lichen sclerosus et atrophicus. Cultivation of spirochetes from lesional skin succeeded in five patients (five of 68) with morphoea, but failed in patients with lichen sclerosus et atrophicus. In Europe and Asia, serological detection of antibodies against B. burgdorferi was described in 0-60% (138 of 609) of patients with morphoea and in 19% (six of 32) in the U.S.A. For lichen sclerosus et atrophicus 0-25% of the published cases (three of 23) in Europe and Asia were seropositive. DNA from B. burgdorferi was detected by PCR in 0-100% (17 of 82) of the tissues of patients with morphoea in Europe and Asia, but not a single case among 98 patients was reported to be positive from the U. S.A. In Europe and Asia, borrelial DNA was detected in 0-100% (nine of 28) of the cases with lichen sclerosus et atrophicus, whereas in the U.S.A. none of 48 patients was positive. There are two possible explanations for these contradictory findings: the most likely is that B. burgdorferi is not a causative agent for morphoea. Another possible explanation could be that a subset of morphoea is caused by a special subspecies of B. burgdorferi that is present in Europe and Asia but does not occur in the U.S.A.
Idea Production in Nominal and Virtual Groups: Does Computer-Mediated Communication Improve Group Brainstorming?
2000-04-01

Findings in previous research on the effectiveness of computer brainstorming groups as compared to other kinds of brainstorming groups are equivocal with regard to the quantity and quality of idea production. Nevertheless, using computer-mediated communication is often recommended to enhance idea production in brainstorming groups. This recommendation is based on the assumption that reading others' ideas leads to mutual cognitive stimulation. To test this assumption, two conceptually similar experiments were run comparing two-member and four-member computer brainstorming groups with and without the opportunity to exchange ideas. Although in conditions with computer-mediated communication there should have been three times as much stimulation for individuals in four-member groups as compared to two-member groups, irrespective of group size neither quantity nor quality measures showed any improvement over conditions without computer-mediated communication. Instead, in both experiments, communication led to uniformity tendencies which lowered flexibility of idea production.
Phospholipid and sterol analysis of plasma membranes of azole-resistantCandida albicansstrains
2000-04-01

The phospholipid and sterol composition of the plasma membranes of five fluconazole-resistant clinical Candida albicans isolates was compared to that of three fluconazole-sensitive ones. The three azole-sensitive strains tested and four of the five resistant strains did not exhibit any major difference in their phospholipid and sterol composition. The remaining strain (R5) showed a decreased amount of ergosterol and a lower phosphatidylcholine:phosphatidylethanolamine ratio in the plasma membrane. These changes in the plasma membrane lipid and sterol composition may be responsible for an altered uptake of drugs and thus for a reduced intracellular accumulation of fluconazole thereby providing a mechanism for azole resistance.
Detection of a relation between respiration and CSF pulsation with an echoplanar technique
2000-04-01

The flow of cerebrospinal fluid (CSF) through the aqueduct was studied with an echoplanar imaging technique. Images (1024) of a slice perpendicular to the aqueduct were acquired with a repetition time of 107 msec and a flip angle of 90 degrees. This imaging technique is very sensitive for flow into the selected slice, although a quantitative assessment of flow velocities is not possible. Simultaneously with the image data acquisition, data from a pulse oximeter and a respiration belt were recorded. For each data point, a delay time to the preceding cardiac pulse was determined from the recorded pulse wave. The signal intensities could then be assigned to the cardiac cycle. Each cardiac interval was assigned to one of eight respiratory phases, and an average signal curve during the cardiac interval was calculated for each respiration phase. The evaluation showed to signal maxima within the cardiac interval, which could be identified as a downward flow at 10% and an upward flow at 80% of the cardiac pulse interval by measurements with additional saturation pulses. In examinations of 22 healthy volunteers, an influence of respiration on the flow through the aqueduct was found. In spite of interindividual variability, comparable effects could be observed in all volunteers. In the late expiration phase the caudally directed flow was at its maximum, whereas the cranially directed flow was maximal in the post-inspiration phase.