julilili42/papers huggingface dataset:
Cadmium and iron transport by members of a plant metal transporter family in Arabidopsis with homology to Nramp genes
2000-04-25

Metal cation homeostasis is essential for plant nutrition and resistance to toxic heavy metals. Many plant metal transporters remain to be identified at the molecular level. In the present study, we have isolated AtNramp cDNAs from Arabidopsis and show that these genes complement the phenotype of a metal uptake deficient yeast strain, smf1 . AtNramp s show homology to the Nramp gene family in bacteria, yeast, plants, and animals. Expression of AtNramp cDNAs increases Cd 2+ sensitivity and Cd 2+ accumulation in yeast. Furthermore, AtNramp3 and AtNramp4 complement an iron uptake mutant in yeast. This suggests possible roles in iron transport in plants and reveals heterogeneity in the functional properties of Nramp transporters. In Arabidopsis , AtNramps are expressed in both roots and aerial parts under metal replete conditions. Interestingly, AtNramp3 and AtNramp4 are induced by iron starvation. Disruption of the AtNramp3 gene leads to slightly enhanced cadmium resistance of root growth. Furthermore, overexpression of AtNramp3 results in cadmium hypersensitivity of Arabidopsis root growth and increased accumulation of Fe, on Cd 2+ treatment. Our results show that Nramp genes in plants encode metal transporters and that AtNramps transport both the metal nutrient Fe and the toxic metal cadmium.
PCV salvage chemotherapy for recurrent primary CNS lymphoma
2000-04-25

The outcome for immunocompetent patients with primary CNS lymphoma (PCNSL) has improved substantially due to combined therapy with whole-brain radiotherapy (WBRT) and chemotherapy using methotrexate and cytarabine or high-dose methotrexate (HD-MTX).1-3 Concerning therapy for patients with progression during first-line therapy (6.4%)1 or with relapse after initial complete response (CR; 34 to 40%),1,3 the best results were reported with WBRT after failure of HD-MTX–containing regimens (CR in 6 of 12 patients3 or in all 4 patients4) and with cytarabine after DeAngelis’ combined modality therapy (CR in 3 of 8 patients).5 Radiochemotherapy according to DeAngelis et al.1 and, since 1998, HD-MTX (8 g/m2 body surface area)3 were primary treatments for patients with PCNSL at our institution. All patients presenting with recurrent or progressive PCNSL between 1995 and 1998 were intended to be treated with PCV chemotherapy (procarbazine 60 mg/m2, days 8 through 21; lomustine (CCNU) 110 mg/m2, day 1; vincristine 2 mg, days 8 and 29) ...
Microscopic study of energy and centrality dependence of transverse collective flow in heavy-ion collisions
2000-04-25

The centrality dependence of directed and elliptic flow in light and heavy systems of colliding nuclei is studied within two microscopic transport models at energies from 1 AGeV to 160 A GeV. The pion directed flow has negative slope in the midrapidity range irrespective of bombarding energy and mass number of the colliding ions. In contrast, the directed flow of nucleons vanishes and even develops antiflow in the midrapidity range in (semi)peripheral collisions at energies around 11.6 A GeV and higher. The origin of the disappearance of flow is linked to nuclear shadowing. Since the effect is stronger for a light system, it can be distinguished from the similar phenomenon caused by the quark-gluon plasma formation. In the latter case the disappearance of the flow due to the softening of the equation of state should be most pronounced in collisions of heavy ions. The centrality dependence of the elliptic flow shows that the maximum in the <v_2(b)> distribution is shifted to very peripheral events with rising incident energy, in accord with experimental data. This is an indication of the transition from baryonic to mesonic degrees of freedom in hot hadronic matter.
ChemInform Abstract: In situ Investigation of the Reaction of Ammonium Monomolybdate (NH4)2MoO4 with Ammonia: The Structure of (NH4)2[Mo3O10].
2000-04-25

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.
Serum amyloid A‐derived peptides, present in human rheumatic synovial fluids, induce the secretion of interferon‐γ by human CD4+ T‐lymphocytes
2000-04-27

Serum amyloid A (SAA) is a major acute‐phase protein whose biochemical functions remain largely obscure. Human rheumatic synovial fluids were screened by high performance liquid chromatography mass spectrometry for SAA‐derived peptides, specifically the sequence AGLPEKY (SAA 98–104 ) which was previously shown to modulate various leukocyte functions. Two such fluids were found to contain a truncated version of SAA 98–104 . Synthetic SAA 98–104 and several of its analogs were shown capable of binding isolated human CD 4 + T‐lymphocytes and stimulating them to produce interferon‐γ. Given the high acute‐phase serum level of SAA and its massive proteolysis by inflammatory related enzymes, SAA‐derived peptides may be involved in host defense mechanisms.
<title>Preprocessing and quality assessment of crosshole georadar data</title>
2000-04-27

The inversion of direct arrival times is the most common technique in crosshole georadar surveying. Results of such a tomographic radar experiment can be easily contaminated by errors during data acquisition and processing. Our study of synthetic and field data shows that careful and detailed pre- processing analysis gives an impression of data quality and the factors influencing and limiting the quality for the particular field experiment. Synthetic data examples show how certain systematic errors, e.g. unrecognized borehole deviation, can be identified and distinguished from the expected real subsurface structure. However, delay problems, e.g. caused by false zero-time corrections, are often more difficult to identify, particularly in a noisy environment or in media where high velocity contrasts are present. The examples and calculations show that careful pre-inversion processing and handling of tomographic data lead to a quality increase and to more reliable tomograms.
Endotoxemia in organ donors: graft function following liver transplantation
2000-04-28

Translocation of endotoxin (LPS) to the portal-venous system is produced by multiple factors. In the case of normal liver function, LPS is rapidly cleared from the portal blood by Kupffer cells; in impaired liver function, LPS can reach the systemic circulation. The objective of this study was to investigate whether elevated donor endotoxin levels affect graft function in the recipient. LPS levels in donor plasma were measured in 14 consecutive liver transplantations. Grafts with donor LPS levels < or = 12 pg/ml had a function probability of 100% after 600 days (n = 10). LPS concentrations of > 12 pg/ml in donor plasma led to loss of function in 75% of the liver grafts (n = 4; P = 0.003; Wilcoxon). Elevated LPS values in donor plasma seem to impair the prognosis of the grafts and could predict poor graft function as early as at the time of brain death.
The quality of a liver graft
2000-04-28

Because transplantation success is influenced by the quality of the graft, the objective of this study was to find parameters to evaluate transplant livers in the recipient centre. In 64 liver grafts, the venous effluates of a portal back-table flush were investigated for various parameters. Amongst them, glutathione S-transferase (GST), glutamate dehydrogenase (GLDH) and the leucocyte count were found superior in predicting graft survival. Using the combination of these parameters, 100-day graft survival of between 95% (all parameters positive) and 0% (all parameters negative) was predicted. We concluded that good liver grafts are characterized by a low width of injury (cytosolic component: GST), a low depth of injury (mitochondrial component: GLDH), as well as by a potential to induce tolerance (passenger leucocytes). Perfusate analysis seems to be a valuable tool to recognize problematic grafts in advance and to quantify the "graft factor" in considerations concerning quality control.
RANTES in the postoperative course after liver transplantation
2000-04-28

RANTES (regulated upon activation, normal T-cell expressed and secreted), an inflammatory cytokine, promotes accumulation and activation of leukocytes. In 67 liver transplantations, systemic concentrations of RANTES were correlated to graft survival and incidence of rejection. RANTES levels either increased to highly elevated levels at day 14 (84 +/- 64 ng/ml; group 1; n = 43) or remained within the limit of healthy controls (19 +/- 11 ng/ml at day 14; group 2; n = 24). The 100-day graft function rate was 0.91 in group 1 and 0.63 in group 2 (P = 0.002). The risk ratio for rejection during the first 100 days was increased 2.2-fold in group 2 compared to group 1 (P = 0.02). High postoperative release of RANTES after liver transplantation, a beneficial factor, may reflect a general systemic immunological activation. It can be concluded that high early systemic RANTES levels may play a role in immunological recognition leading to a tolerance of the liver graft.
Invaded cluster algorithm for critical properties of periodic and aperiodic planar Ising models
2000-04-28

We demonstrate that the invaded cluster algorithm, recently introduced by\\nMachta et al, is a fast and reliable tool for determining the critical\\ntemperature and the magnetic critical exponent of periodic and aperiodic\\nferromagnetic Ising models in two dimensions. The algorithm is shown to\\nreproduce the known values of the critical temperature on various periodic and\\nquasiperiodic graphs with an accuracy of more than three significant digits. On\\ntwo quasiperiodic graphs which were not investigated in this respect before,\\nthe twelvefold symmetric square-triangle tiling and the tenfold symmetric\\nT\\\\"ubingen triangle tiling, we determine the critical temperature. Furthermore,\\na generalization of the algorithm to non-identical coupling strengths is\\npresented and applied to a class of Ising models on the Labyrinth tiling. For\\ngeneric cases in which the heuristic Harris-Luck criterion predicts deviations\\nfrom the Onsager universality class, we find a magnetic critical exponent\\ndifferent from the Onsager value. But also notable exceptions to the criterion\\nare found which consist not only of the exactly solvable cases, in agreement\\nwith a recent exact result, but also of the self-dual ones and maybe more.\\n
Influence of perioperative sHLA I concentrations on the histological development of the liver graft
2000-04-28

Soluble HLA I (sHLA I) in human serum are ascribed an immunoregulatory role in the context of organ transplantation. Based on histological findings, the objective of the current study was to evaluate the protective influence of sHLA I in liver transplantation from the time point of reperfusion. The sHLA I concentrations in serum samples derived from the liver vein immediately after reperfusion (flush catheter) of 38 patients with liver transplantations were determined by ELISA. The postoperative histological findings of the transplant biopsies were categorized according to rejection, endothelialitis, cholestasis, and necrosis, as well as fatty degeneration. An evaluation according to Kaplan-Meier showed a lower incidence for all of these factors in liver grafts with high sHLA concentrations (P < 0.05). We conclude that low sHLA I concentrations during reperfusion correlate with later complications, thus indicating that sHLA I may have protective potential in liver transplantation.
Improvement of hepatorenal syndrome with extracorporeal albumin dialysis mars: Results of a prospective, randomized, controlled clinical trial
2000-05-01

In hepatorenal syndrome (HRS), renal insufficiency is often progressive, and the prognosis is extremely poor under standard medical therapy. The molecular adsorbent recirculating system (MARS) is a modified dialysis method using an albumin-containing dialysate that is recirculated and perfused online through charcoal and anion-exchanger columns. MARS enables the selective removal of albumin-bound substances. A prospective controlled trial was performed to determine the effect of MARS treatment on 30-day survival in patients with type I HRS at high risk (bilirubin level, ≥15 mg/dL) compared with standard treatment. Thirteen patients with cirrhosis with type I HRS were included from 1997 to 1999. All were Child’s class C, with Child-Turcotte-Pugh scores of 12.4 ± 1.0, United Network for Organ Sharing status 2A, and total bilirubin values of 25.7 ± 14.0 mg/dL. Eight patients were treated with the MARS method in addition to hemodiafiltration (HDF) and standard medical therapy, and 5 patients were in the control group (HDF and standard medical treatment alone). None of these patients underwent liver transplantation or received a transjugular intrahepatic portosystemic shunt or vasopressin analogues during the observation period. In the MARS group, 5.2 ± 3.6 treatments (range, 1 to 10 treatments) were performed for 6 to 8 hours daily per patient. A significant decrease in bilirubin and creatinine levels ( P &lt; .01) and increase in serum sodium level and prothrombin activity ( P &lt; .01) were observed in the MARS group. Mortality rates were 100% in the control group at day 7 and 62.5% in the MARS group at day 7 and 75% at day 30, respectively ( P &lt; .01). We conclude that the removal of albumin-bound substances with the MARS method can contribute to the treatment of type I HRS.
Improvement of hepatorenal syndrome with extracorporeal albumin dialysis mars: Results of a prospective, randomized, controlled clinical trial
2000-05-01

In hepatorenal syndrome (HRS), renal insufficiency is often progressive, and the prognosis is extremely poor under standard medical therapy. The molecular adsorbent recirculating system (MARS) is a modified dialysis method using an albumin-containing dialysate that is recirculated and perfused online through charcoal and anion-exchanger columns. MARS enables the selective removal of albumin-bound substances. A prospective controlled trial was performed to determine the effect of MARS treatment on 30-day survival in patients with type I HRS at high risk (bilirubin level,15 mg/dL) compared with standard treatment. Thirteen patients with cirrhosis with type I HRS were included from 1997 to 1999. All were Child's class C, with Child-Turcotte-Pugh scores of 12.4 ± 1.0, United Network for Organ Sharing status 2A, and total bilirubin values of 25.7 ± 14.0 mg/dL. Eight patients were treated with the MARS method in addition to hemodiafiltration (HDF) and standard medical therapy, and 5 patients were in the control group (HDF and standard medical treatment alone). None of these patients underwent liver transplantation or received a transjugular intrahepatic portosystemic shunt or vasopressin analogues during the observation period. In the MARS group, 5.2 ± 3.6 treatments (range, 1 to 10 treatments) were performed for 6 to 8 hours daily per patient. A significant decrease in bilirubin and creatinine levels (P < .01) and increase in serum sodium level and prothrombin activity (P < .01) were observed in the MARS group. Mortality rates were 100% in the control group at day 7 and 62.5% in the MARS group at day 7 and 75% at day 30, respectively (P < .01). We conclude that the removal of albumin-bound substances with the MARS method can contribute to the treatment of type I HRS.
Deficiency of Inducible Nitric Oxide Synthase Protects Against MPTP Toxicity In Vivo
2000-05-01

Abstract: MPTP produces clinical, biochemical, and neuropathologic changes reminiscent of those that occur in idiopathic Parkinson's disease (PD). In the present study we show that MPTP treatment led to activation of microglia in the substantia nigra pars compacta (SNpc), which was associated and colocalized with an increase in inducible nitric oxide synthase (iNOS) expression. In iNOS‐deficient mice the increase of iNOS expression but not the activation of microglia was blocked. Dopaminergic SNpc neurons of iNOS‐deficient mice were almost completely protected from MPTP toxicity in a chronic paradigm of MPTP toxicity. Because the MPTP‐induced decrease in striatal concentrations of dopamine and its metabolites did not differ between iNOS‐deficient mice and their wild‐type littermates, this protection was not associated with a preservation of nigrostriatal terminals. Our results suggest that iNOS‐derived nitric oxide produced in microglia plays an important role in the death of dopaminergic neurons but that other mechanisms contribute to the loss of dopaminergic terminals in MPTP neurotoxicity. We conclude that inhibition of iNOS may be a promising target for the treatment of PD.
Influence of calcium hydroxide intracanal dressings on the prognosis of teeth with endodontically induced periapical lesions
2000-05-01

Aim This prospective clinical study explored the influence of calcium hydroxide as an interappointment dressing on the healing of periapical lesions associated with pulpless teeth that had not been endodontically treated previously. This was achieved by comparing the prognosis after a two‐visit root canal treatment with that following a one‐visit treatment. Methodology Seventy‐three patients were recruited having one tooth with an endodontically induced lesion. Of these patients, 67 could be re‐examined. Calcium hydroxide was placed in the instrumented root canals of 31 teeth for at least one week and the treatment finished at the second visit. Thirty‐six teeth were root canal treated at one visit. The criteria for success were the absence of signs and symptoms indicating an acute phase of periapical periodontitis and radiographically a periodontal ligament space ofnormal width. Methods for event time analysis were used to evaluate and compare the prognosis of both treatment approaches. Results The probability that complete periapical healing will take place increased continuously with the length of the observation period. In both treatment groups the likelihood that the root canal treatment yields a success within an observation time of five years exceeded 90%. A statistically significant difference between the two treatment groups could not be detected. Conclusions From a microbiological perspective, one‐visit root canal treatment created favourable environmental conditions for periapical repair similar to the two‐visit therapy when calcium hydroxide was used as antimicrobial dressing. One‐visit root canal treatment is an acceptable alternative to two‐visit treatment for pulpless teeth associated with an endodontically induced lesion.
Thyroid Hormone Deficiency Before the Onset of Hearing Causes Irreversible Damage to Peripheral and Central Auditory Systems
2000-05-01

Both a genetic or acquired neonatal thyroid hormone (TH) deficiency may result in a profound mental disability that is often accompanied by deafness. The existence of various TH-sensitive periods during inner ear development and general success of delayed, corrective TH treatment was investigated by treating pregnant and lactating rats with the goitrogen methimazole (MMI). We observed that for the establishment of normal hearing ability, maternal TH, before fetal thyroid gland function on estrus days 17–18, is obviously not required. Within a crucial time between the onset of fetal thyroid gland function and the onset of hearing at postnatal day 12 ( P12), any postponement in the rise of TH-plasma levels, as can be brought about by treating lactating mothers with MMI, leads to permanent hearing defects of the adult offspring. The severity of hearing defects that were measured in 3- to 9-mo-old offspring could be increased with each additional day of TH deficiency during this critical period. Unexpectedly, the active cochlear process, assayed by distortion product otoacoustic emissions (DPOAE) measurements, and speed of auditory brain stem responses, which both until now were not thought to be controlled by TH, proved to be TH-dependent processes that were damaged by a delay of TH supply within this critical time. In contrast, no significant differences in the gross morphology and innervation of the organ of Corti or myelin gene expression in the auditory system, detected as myelin basic protein (MBP) and proteolipid protein (PLP) mRNA using Northern blot approach, were observed when TH supply was delayed for few days. These classical TH-dependent processes, however, were damaged when TH supply was delayed for several weeks. These surprising results may suggest the existence of different TH-dependent processes in the auditory system: those that respond to corrective TH supply (e.g., innervation and morphogenesis of the organ of Corti) and those that do not, but require T3 activity during a very tight time window (e.g., active cochlear process, central processes).
Functional Characterization of the Amanita muscaria Monosaccharide Transporter, AmMst1
2000-05-01

Abstract: Fungal carbohydrate nutrition is an important aspect of ectomycorrhizal symbiosis. At the plant/fungus interface, fungal and root cortical cells compete for monosaccharides, generated from plant‐derived sucrose. Therefore, the kinetic properties of the monosaccharide uptake systems are decisive for the monosaccharide yield of each partner. For the functional characterization of a hexose transporter (AmMst1) of the ectomycorrhizal fungus Amanita muscaria, the entire cDNA was expressed in a Saccharomyces cerevisiae strain unable to take up hexoses. Uptake experiments with 14 C‐labelled monosaccharides resulted in K M values of 0.46 mM for glucose and 4.20 mM for fructose, revealing a strong preference of AmMst1 for glucose as substrate. Glucose uptake by AmMst1 was strongly favoured even in the presence of a large excess of fructose. Comparable affinities of AmMst1 for glucose, 3‐O‐methyl glucose and mannose were obtained. In contrast, AmMst1 imported galactose with a much lower efficiency, revealing that this transporter distinguishes pyranoses by steric hindrance at the C‐4 position. While yeast contains numerous hexose transporter genes, the AmMst1 gene seems to be the main, if not the only, hexose transporter that is expressed in A. muscaria, as concluded from the comparison of hexose import properties of A. muscaria protoplasts and AmMst1 expressed in yeast.
Ectopic expression of the neuropeptide pigment-dispersing factor alters behavioral rhythms in Drosophila melanogaster.
2000-05-01

To study the function of the neuropeptide pigment-dispersing factor (PDF) in the circadian system of Drosophila, we misexpressed the pdf gene from the grasshopper Romalea in the CNS of Drosophila and investigated the effect of this on behavioral rhythmicity. pdf was either ectopically expressed in different numbers of neurons in the brain or the thoracical nervous system or overexpressed in the pacemaker neurons alone. We found severe alterations in the activity and eclosion rhythm of several but not all lines with ectopic pdf expression. Only ectopic pdf expression in neurons that projected into the dorsal central brain severely influenced activity rhythms. Therefore, we conclude that PDF acts as a neuromodulator in the dorsal central brain that is involved in the rhythmic control of behavior. Overexpression of pdf in the pacemaker neurons alone or in the other neurons that express the clock genes period (per) and timeless (tim) did not disturb the activity rhythm. Such flies still showed a rhythm in PDF accumulation in the central brain terminals. This rhythm was absent in the terminals of neurons that expressed PDF ectopically. Probably, PDF is rhythmically processed, transported, or secreted in neurons expressing per and tim, and additional PDF expression in these cells does not influence this rhythmic process. In neurons lacking per and tim, PDF appears to be continuously processed, leading to a constant PDF secretion at their nerve terminals. This may lead to conflicting signals in the rhythmic output pathway and result in a severely altered rhythmic behavior.