julilili42/papers huggingface dataset:
Differential expression and regulation of AE2 anion exchanger subtypes in rabbit parietal and mucous cells
2001-08-01

1. The anion exchanger isoform 2 (AE2) gene encodes three subtypes (AE2a, b and c), which have different N-termini and tissue distributions. AE2 is expressed at high levels in the stomach, where it is thought to mediate basolateral base exit during acid production. The present study investigated if the three AE2 subtypes are differentially expressed and regulated in different cell types within the gastric mucosa. 2. The cloning strategy to obtain rabbit AE2a, b and c cDNAs combined genomic PCR and RT-PCR based on primers deduced from the rat sequences. Semiquantitative RT-PCR using homologous primers revealed much higher AE2 mRNA expression in rabbit parietal cells (PCs) than in mucous cells (MCs). The subtype expression pattern was AE2b ≫ AE2c ≥ AE2a in PCs and AE2a &gt;AE2b ≫ AE2c in MCs. Sequence analysis revealed the presence of a highly conserved protein kinase C (PKC) consensus sequence in the AE2a alternative N-terminus. 3. Maximal Cl(−)-HCO(3)(−) exchange rates, measured fluorometrically in BCECF-loaded cultured gastric cells, were much higher in PCs than MCs. PKC activation by phorbol ester stimulated maximal Cl(−)-HCO(3)(−) exchange rates in MCs but not in PCs, whereas forskolin had no effect in each cell type. 4. In summary, rabbit PCs and MCs, which originate from the same gastric stem cell population, display a completely different AE2 subtype expression pattern. Therefore, AE2 subtype expression is not organ specific but cell type specific. The different regulation of anion exchange in parietal and mucous cells suggests that AE2 subtypes may be differentially regulated.
Hypomanic Personality, Social Anhedonia and Impulsive Nonconformity: Evidence for Familial Aggregation?
2001-08-01

Schizophrenic and affective spectrum disorders aggregate in the families of patients afflicted with such disorders. Possible vulnerability markers for these disorders should therefore also run in families. The Chapmans and their coworkers developed the Hypomanic Personality Scale (HYP) to identify people at risk for affective disorders, and the scales Social Anhedonia (SA) and Impulsive Nonconformity (IMP) to assess schizotypy (Chapman et al., 1976, 1984; Eckblad & Chapman, 1986). The present family study investigated the familial resemblance of the HYP, SA, and IMP Scale using a maximum-likelihood approach. Index participants and their relatives (n = 717) completed a questionnaire packet that included the above-mentioned scales. Stepwise several models of familial correlations were specified and tested dealing with the influence of sex of parents and offspring and of interindividual cross-trait resemblance. For all three measures, there was evidence of familial resemblance. For SA and IMP, we found hints for possible assortative mating; additionally for HYP and IMP, an interindividual cross-trait resemblance (with correlations of 0.14 and 0.18, respectively) between family members emerged. The results support the validity of the HYP, SA, and IMP Scale. It is discussed whether HYP and IMP represent different aspects of a shared latent liability.
The Proteasomal Substrate Stm1 Participates in Apoptosis-like Cell Death in Yeast
2001-08-01

We have identified the yeast gene STM1 in an overexpression screen for new proteasomal substrates. Stm1 is unstable in wild-type cells and stabilized in cells with defective proteasomal activity and thus a bona fide substrate of the proteasome. It is localized in the perinuclear region and is required for growth in the presence of mutagens. Overexpression in cells with impaired proteasomal degradation leads to cell death accompanied with cytological markers of apoptosis: loss of plasma membrane asymmetry, chromatin condensation, and DNA cleavage. Cells lacking Stm1 display deficiency in the apoptosis-like cell death process induced by treatment with low concentrations of H 2 O 2 . We suggest that Stm1 is involved in the control of the apoptosis-like cell death in yeast. Survival is increased when Stm1 is completely missing from the cells or when inhibition of Stm1 synthesis permits proteasomal degradation to decrease its amount in the cell. Conversely, Stm1 accumulation induces cell death. In addition we identified five other genes whose overexpression in proteasomal mutants caused similar apoptotic phenotypes.
Chimeric tumor suppressor 1, a p53-derived chimeric tumor suppressor gene, kills p53 mutant and p53 wild-type glioma cells in synergy with irradiation and CD95 ligand.
2001-08-01

Adenoviral chimeric tumor suppressor 1 (CTS1) gene transfer was evaluated as a novel approach of somatic gene therapy for malignant glioma. CTS1 is an artificial p53-based gene designed to resist various pathways of p53 inactivation. Here, we report that an adenovirus encoding CTS1 (Ad-CTS1) induces growth arrest and loss of viability in all glioma cell lines examined, in the absence of specific cell cycle changes. In contrast, an adenovirus encoding wild-type p53 (Ad-p53) does not consistently induce apoptosis in the same cell lines. Electron microscopic analysis of Ad-CTS1-infected glioma cells reveals complex cytoplasmic pathology and delayed apoptotic changes. Ad-CTS1 induces prominent activation of various p53 target genes, including p21 and MDM-2, but has no relevant effects on BCL-2 family protein expression. Although Ad-CTS1 strongly enhances CD95 expression at the cell surface, endogenous CD95/CD95 ligand interactions do not mediate CTS1-induced cell death. This is because Ad-CTS1 promotes neither caspase activation nor mitochondrial cytochrome c release and because the caspase inhibitors, z-val-Ala-DL-Asp-fluoromethylketone (zVAD)-fmk or z-Ile-Glu-Thr-Asp- fluoromethylketone (z-IETD)-fmk, do not block CTS1-induced cell death. Ad-CTS1 synergizes with radiotherapy and CD95 ligand in killing glioma cells. In summary, Ad-CTS1 induces an unusual type of cell death that appears to be independent of BCL-2 family proteins, cytochrome c release, and caspases. CTS1 gene transfer is a promising strategy of somatic gene therapy for malignant glioma.
Regulation of Staphylococcus aureus Type 5 and Type 8 Capsular Polysaccharides by CO 2
2001-08-01

ABSTRACT Staphylococcus aureus expression of capsular polysaccharide type 5 (CP5) has been shown to be downregulated by CO 2 . Here we show that CO 2 reduces CP5 expression at the transcriptional level and that CO 2 regulates CP8 expression depending on the genetic background of the strains. Growth in the presence of air supplemented with 5% CO 2 caused a significant decrease in CP8 expression in four S. aureus strains, a marginal effect in four strains, and higher CP8 expression in strain Becker. Absolute CP8 expression in the nine S. aureus strains differed largely from strain to strain. Four groups of strains were established due to sequence variations in the promoter region of cap5 and cap8 . To test whether these sequence variations are responsible for the different responses to CO 2 , promoter regions from selected strains were fused to the reporter gene xyl E in pLC4, and the plasmids were electrotransformed into strains Becker and Newman. XylE activity was negatively regulated by CO 2 in all derivatives of strain Newman and was always positively regulated by CO 2 in all derivatives of strain Becker. Differences in promoter sequences did not influence the pattern of CP8 expression. Therefore, the genetic background of the strains rather than differences in the promoter sequence determines the CO 2 response. trans -acting regulatory molecules may be differentially expressed in strain Becker versus strain Newman. The strain dependency of the CP8 expression established in vitro was also seen in lung tissue sections of patients with cystic fibrosis infected with CP8-positive S. aureus strains.
Anticancer Drug‐mediated Induction of Multidrug Resistance‐associated Genes and Protein Kinase C Isozymes in the T‐Lymphoblastoid Cell Line CCRF‐CEM and in Blasts from Patients with Acute Lymphoblastic Leukemias
2001-08-01

The major determinants mediating drug resistance in acute lymphoblastic leukemias (ALL) unresponsive to chemotherapy, are still unclear. For example, it is still unknown whether selection or induction processes are responsible for drug resistance here or whether protein kinase C (PKC) isozymes contribute to the resistant phenotype. Therefore, inducibility of resistance factors or PKC isozymes genes was examined in CCRF‐CEM cells treated with diverse anticancer drugs‐ adriamycin, camptothecin, etoposide or vincristine‐at sublethal concentrations for 24 h. MDR1, MRP1, LRP and PKC isozyme α, β 1 , β 2 , ε, ι, η, θ, ζ gene expression was determined by cDNA‐PCR. We found significant dose‐dependent, mostly combined, induction of the MDR1, MRP1 and LRP genes. Significantly enhanced gene expression of the majority of PKC isozyme genes was found after treatment with camptothecin. PKCζ was upregulated throughout by each anticancer drug applied in this setting. A series of selected CCRF‐CEM‐derived multidrug resistance (MDR) sublines also showed enhanced expression of the PKC isozymes compared to the parental cell line. MDR1 and PKCη gene expression levels were correlated highly significantly. Blasts from two patients with ALL during the first week of monotherapy with steroids revealed combined induction of the MDR1, multidrug resistance‐associated protein 1 (MRP1), lung cancer resistance‐related protein (LRP) and most PKC isozymes, predominantly PKCζ. Another patient with T‐ALL, who failed to respond to four months of intensive chemotherapy, showed an enhanced MRP1 gene expression combined with markedly overexpression of PKCη and PKCθ. Furthermore, the camptothecin and etoposide‐mediated induction of resistance factors in the CCRF‐CEM cell line could be suppressed by staurosporine, a rather unspecific inhibitor of protein kinases. However, selective inhibitors of PKC isozymes (bisindolylmaleimide GÖ 6850, indolocarbazole GÖ 6976) produced no significant effects here. Therefore, the PKC isozymes η, θ and ζ are of interest as potential targets to overcome drug resistance in ALL.
Synthesis and characterization of heptacoordinated tin(IV) complexes. X-ray crystal structure of [nBu2Sn(dappt)]·(Me 2CO)0.5 [H2dappt = 2,6-diacetylpyridine bis(4-phenylthiosemicarbazone)]
2001-08-01

As reações do ligante 2,6-diacetilpiridina bis(4-feniltiossemicarbazona), H2dappt, com R4-mSnXm (m = 2, 3; R = Me, nBu, Ph e X = Cl) resultaram na formação de quatro novos complexos organoestânicos heptacoordenados, os quais foram caracterizados por análise elementar e pelas espectroscopias no IV e Mössbauer. O derivado n-butila, [nBu2Sn(dappt)]·(Me 2CO)0.5, foi também analisado por um estudo de difração de raios X em um monocristal. O complexo cristalizou-se no sistema monoclínico e grupo espacial C2/c, com a = 36,164(14), b = 9,7050(15), c = 26,194(11) Å, beta = 132,00(2)o, Z = 8. A determinação da estrutura revelou um complexo neutro de Sn(IV), numa geometria bipiramidal pentagonal (BPP), com o plano equatoral definido pelos átomos doadores SNNNS do ligante e dois grupos n-bultila nas posições axiais. Também é discutida uma correlação entre os dados de Mössbauer e de difração de raios X, baseada no modelo da carga-pontual.
Detection of melanoma cells in sentinel lymph nodes, bone marrow and peripheral blood by a reverse transcription-polymerase chain reaction assay in patients with primary cutaneous melanoma: association with Breslow's tumour thickness
2001-08-01

RT-PCR-positive SLNs were strongly associated with greater tumour thickness, underlining the prognostic significance of SLN positivity. Similar to certain epithelial malignancies, molecular investigation of the BM might provide complementary prognostic information in the early stages of melanoma. In contrast, no association between positive RT-PCR results in PB and increasing tumour thickness was found, implying that RT-PCR findings in PB are of doubtful clinical relevance in primary melanoma.
A Role for a Novel Luminal Endoplasmic Reticulum Aminopeptidase in Final Trimming of 26 S Proteasome-generated Major Histocompatability Complex Class I Antigenic Peptides
2001-08-01

Peptides presented to cytotoxic T lymphocytes by the class I major histocompatability complex are 8-11 residues long. Although proteasomal activity generates the precise C termini of antigenic epitopes, the mechanism(s) involved in generation of the precise N termini is largely unknown. To investigate the mechanism of N-terminal peptide processing, we used a cell-free system in which two recombinant ornithine decarboxylase (ODC) constructs, one expressing the native H2-K(b)-restricted ovalbumin (ova)-derived epitope SIINFEKL (ODC-ova) and the other expressing the extended epitope LESIINFEKL (ODC-LEova), were targeted to degradation by 26 S proteasomes followed by import into microsomes. We found that the cleavage specificity of the 26 S proteasome was influenced by the N-terminal flanking amino acids leading to significantly different yields of the final epitope SIINFEKL. Following incubation in the presence of purified 26 S proteasome, ODC-LEova generated largely ESIINFEKL that was efficiently converted to the final epitope SIINFEKL following translocation into microsomes. The conversion of ESIINFEKL to SIINFEKL was strictly dependent on the presence of H2-K(b) and was completely inhibited by the metalloaminopeptidase inhibitor 1,10-phenanthroline. Importantly, the converting activity was resistant to a stringent salt/EDTA wash of the microsomes and was only apparent when transport of TAP, the transporter associated with antigen processing, was facilitated. These results strongly suggest a crucial role for a luminal endoplasmic reticulum-resident metalloaminopeptidase in the N-terminal trimming of major histocompatability complex class I-associated peptides.
Hardware support for adaptive subdivision surface rendering
2001-08-01

Adaptive subdivision of triangular meshes is highly desirable for surface generation algorithms including adaptive displacement mapping in which a highly detailed model can be constructed from a coarse triangle mesh and a displacement map. The communication requirements between the CPU and the graphics pipeline can be reduced if more detailed and complex surfaces are generated, as in displacement mapping, by an adaptive tessellation unit which is part of the graphics pipeline. Generating subdivision surfaces requires a large amount of memory in whicmultiple arbitrary accesses are required to neighbouring vertices to calculate the new vertices. In this paper we present a meshing scheme and new architecture for the implementation of adaptive subdivision of triangular meshes that allows for quick access using a small memory making it feasible in hardware, while at the same time allowing for new vertices to be adaptively inserted. The architecutre is regular and characterized by an efficient data management that minimizes the data storage and avoids the wait cycles that would be associated with the multiple data accesses required for traditional subdivision. This architecture is presented as an improvement for adaptive displacement mapping algorithms, but could also be used for adaptive subdivision surface generation in hardware.
The Phosphinomethylmalate Isomerase Gene pmi, Encoding an Aconitase-Like Enzyme, Is Involved in the Synthesis of Phosphinothricin Tripeptide in Streptomyces viridochromogenes
2001-08-01

ABSTRACT Streptomyces viridochromogenes Tü494 produces the antibiotic phosphinothricin tripeptide (PTT). In the postulated biosynthetic pathway, one reaction, the isomerization of phosphinomethylmalate, resembles the aconitase reaction of the tricarboxylic acid (TCA) cycle. It was speculated that this reaction is carried out by the corresponding enzyme of the primary metabolism (C. J. Thompson and H. Seto, p. 197–222, in L. C. Vining and C. Stuttard, ed., Genetics and Biochemistry of Antibiotic Production, 1995). However, in addition to the TCA cycle aconitase gene, a gene encoding an aconitase-like protein (the phosphinomethylmalate isomerase gene, pmi ) was identified in the PTT biosynthetic gene cluster by Southern hybridization experiments, using oligonucleotides which were derived from conserved amino acid sequences of aconitases. The deduced protein revealed high similarity to aconitases from plants, bacteria, and fungi and to iron regulatory proteins from eucaryotes. Pmi and the S. viridochromogenes TCA cycle aconitase, AcnA, have 52% identity. By gene insertion mutagenesis, a pmi mutant (Mapra1) was generated. The mutant failed to produce PTT, indicating the inability of AcnA to carry out the secondary-metabolism reaction. A His-tagged protein (Hispmi*) was heterologously produced in Streptomyces lividans . The purified protein showed no standard aconitase activity with citrate as a substrate, and the corresponding gene was not able to complement an acnA mutant. This indicates that Pmi and AcnA are highly specific for their respective enzymatic reactions.
Effects of Gallium and Mercury Ions on Transport Systems
2001-08-01

Mercury was previously shown to exert toxic effects by influencing ion channels and transporters in the kidney and brain. Gallium alloys were suggested as less toxic restorative materials. To compare the toxicity of gallium ions with those of mercury ions, we applied gallium nitrate Ga(NO 3 ) 3 (0.1-100 μM and mercuric chloride (HgCl 2 ) (0.001-10 μM) to Xenopus oocytes expressing mammalian ion channels and transport proteins. Mercury (10 μM) inhibited the K + -channels ROMK and HERG, the phosphate transporter NaPi-3, the amino acid transporter rBAT, the cation transporter OCT-2, and the osmolyte transporter BGT. It activated the I Ks channel but did not affect the Na+-channel ENaC, the anion channel NaPi-1, and the glucose transporter SGLT-1. Gallium was without significant effect on the channels and on SGLT1, NaPi-3, and rBAT, but inhibited BGT and OCT-2. In conclusion, both Hg 2+ and Ga 3+ may exert toxic effects on transport systems, which may partially explain their cytotoxic effects.
2.3-Dihydro-2-Methoxyethylimino-L,3-Dimethylimidazol - Ein Neuer Hemilabil Koordinierender Chelatligand [1]
2001-08-01

The bifunctional 2,3-dihydro-2-methoxyethylimino-l,3-dimethylimidazole (C 8 H 15 N 3 O , 10) is obtained from the reaction of methoxyethyl tosylate (7) and 2,3-dihydro-2-imino-1,3- dimethylimidazole (8) followed by deprotonation in good yield. 10 reacts with {(COD)RhCl}2 (COD = 1,5-cyclooctadiene) to give the imine complex (C 8 H 15 N 3 O)Rh(COD)Cl (11), which is converted into the chelate complex [(C 8 H 15 N 3 O)Rh(COD)]BF 4 (12) on treatment with AgBF 4 . The imine complex (C 8 H 15 N 3 O) 2 PdCl 2 (13) is formed through the reaction of 10 with (PhCN) 2 PdCl 2 . The X-ray structures of 11, 13 and 2 C 8 H 15 N 3 O · H 2 PdCl 4 (15) are reported
2,3-Tetrakis[4-(N-2-naphthyl-N-phenylamino)phenoxy]-substituted Metal-free and Metal Phthalocyanines as a Novel Class of Amorphous Molecular Materials
2001-08-01

Abstract A novel family of metal-free and metal phthalocyanines containing triarylamine moieties are synthesized. These compounds are well soluble and readily form stable amorphous glasses with high glass transition temperatures, as evidenced by differential scanning calorimetry and X-ray diffraction, and constitute a new class of amorphous molecular materials.
Seasonal rhythms of 6‐sulphatoxymelatonin (aMT6s) excretion in female rats are abolished by growth of malignant tumors
2001-08-01

The effect of development and growth of malignant tumors on pineal melatonin production was studied in two different hormone‐dependent tumor systems in female rats. Urinary excretion of 6‐sulphatoxymelatonin (aMT6s), the metabolic end product of melatonin, which parallels its production, was determined by radioimmunoassay at fortnightly or monthly intervals over the period of 1 year in female F344 Fischer rats bearing chemically‐induced mammary carcinomas and in BDII/Han rats with spontaneous endometrial carcinomas. Untreated Fischer rats and BDII/Han rats in which tumor growth was suppressed by treatment with a progestin served as controls. Based on the cosinor analysis, animals without tumors showed significant seasonal rhythms of aMT6s excretion, with peaks in August (Fischer rats) and in May (BDII/Han rats). In contrast, such rhythms were absent in animals with developing and manifest tumors. It is concluded that animals kept under constant environmental conditions still show seasonal rhythms of pineal activity. Tumor development and growth affect pineal activity leading to disturbance of these rhythms.
Diagnosis of Human Ependymomas: Computer-Assisted Decision-Making with the Bayesian Tool “Medes”
2001-08-01

Diagnostic decision-making in pathology involves gathering observational evidence and using it to reason and to decide which out of a number of possible diagnoses is most likely. In many areas of Pathology, a rich body of objective morphological numerical information exists. However, pathologists cannot make optimal use of this information, because, like all humans, they are not good at handling large amounts of numerical data. MEDES (Medical Decision Shell), a tool developed by the authors, has been used to develop a decision-making model for histological and clinical diagnosis of human ependymomas. 268 human ependymomas collected in our laboratory of neuropathology were studied. 176 ependymomas were used as training test: 79 typical ependymomas, WHO-Grade II), 34 subependymomas, 22 myxopapillary ependymomas, and 41 anaplastic ependymomas. The frequencies of location, age and sex and of forty one histological features were considered. All histological features were evaluated on a four-degree scale. On the basis of this information, MEDES produces a decision making model using Bayesian statistics. 92 new cases of ependymomas were then tested. MEDES selects the question that discriminates best between the diagnoses, updates the probabilities of the diagnosis according to the answer with Bayesian statistics, and iterates the procedure. MEDES stops asking questions when further evidence cannot change the most probable diagnosis. With this method, 91.3% of the tested tumors were classified correctly. MEDES allows to make objective use of statistical data in the histological diagnosis of ependymomas. It discriminates between important and unimportant questions, and asks only for the relevant information. MEDES provides pathologists and students with a vehicle to improve logical consistency and reproducibility in diagnostic practice and objectivity of diagnostic decisions.
CENTER VORTICES IN CONTINUUM YANG-MILLS THEORY
2001-08-01

The properties of center vortices are discussed within continuum Yang-Mills\\ntheory. By starting from the lattice theory and carefully performing the\\ncontinuum limit the gauge potential of center vortices is obtained and the\\ncontinuum analog of the maximal center gauge fixing is extracted. It is shown,\\nthat the Pontryagin index of center vortices is given by their\\nself-intersection number, which vanishes unless the center vortices host\\nmagnetic monpoles, which make the vortex sheets non-oriented.\\n
MOLECULAR PATHOGENESIS OF EPSTEIN-BARR VIRUS ASSOCIATED POSTTRANSPLANT LYMPHOMAS: NEW INSIGHTS THROUGH LATENT MEMBRANE PROTEIN 1 FINGERPRINTING1
2001-08-01

These results show that highly selected CD34+ PBSCT does not protect against transfer of EBV positive founder cells of donor type PTL and that, after allo-SCT, recipient type PTLs are not uncommon. Outgrowth of recipient type lymphoma may be favoured by LMP1 deletion variant strains present in recipient lymphocytes.