bluuebunny/crossref_metadata_2025 huggingface dataset:
Sequencing analysis of a 15·4 kb fragment of yeast chromosome XIV identifies the RPD3, PAS8 and KRE1 loci, and five new open reading frames
Authors: Maftahi M. , Nicaud J.‐M. , Levesque H. , Gaillardin C.
Published: May 2005

The DNA sequence of a 15·4 kb region covering the left arm of chromosome XIV from Saccharomyces cerevisiae was determined. This region contains eight open reading frames (ORFs) which code for proteins of more than 100 amino acids. Three ORFs correspond to the RPD3, PAS8 and KRE1 loci, described previously. Three ORFs show limited homology with known proteins: NO330 with the recessive suppressor of secretory defect SAC1, NO325 with YCR094W identified during chromosome III sequencing; whereas NO315 presents a motif conserved in the dnaJ family. Two ORFs (NO320 and NO325) show no homology to known proteins within the databases screened, but NO320 corresponds to a serine‐threonine‐rich protein. The sequence has been entered in the EMBL data library under Accession Number Z46259.
SSU71, encoding the largest subunit of TFIIF, is located on the right arm of chromosome VII in Saccharomyces cerevisiae
Authors: Sun Zu‐Wen , Hampsey Michael
Published: May 2005

SSU71 (TFG1) is an essential nuclear gene encoding the largest subunit of the yeast general transcription factor TFIIF. The SSU71 gene was physically mapped to the right arm of chromosome VII, physically linked to QCR9, by hybridization of the cloned gene to CHEF and lambda clone grid blots. This assignment was confirmed by genetic mapping. A search of the nucleotide sequence databases revealed that SSU71 is immediately adjacent to the TYS1 gene, which encodes tRNATyr synthetase. TYS1 was reported previously to lie on chromosome XV based on sequence overlap with the adjacent UBR1 gene. The mapping data reported here established that TYS1 and UBR1 do not lie on chromosome XV; rather the SSU71‐TYS1‐UBR1 gene cluster lies on the right arm of chromosome VII, physically linked to QCR9 and genetically linked to ade3 and ser2.
XVI. Yeast sequencing reports. A new essential gene GCR4 located in the upstream region of GCR1
Authors: Uemura Hiroshi , Jigami Yoshifumi
Published: May 2005

A new essential gene of Saccharomyces cerevisiae was found upstream of GCR1. Its cloning and sequencing predict a 280 amino acid protein (32 577 Da). The predicted protein is fairly hydrophobic, and a search of the database did not identify any homologous proteins. A LEU2 disruption at codon 104 was lethal, but disruption at codon 221 showed a temperature‐sensitive conditional growth phenotype. Abnormalities were observed in some glycolytic enzyme levels. The sequence has been submitted to GenBank‐EMBL‐DDBJ under Accession Number D29645.
GSG1, a yeast gene required for sporulation
Authors: Kaytor Michael D. , Livingston Dennis M.
Published: May 2005

We have identified a gene, GSG1 (general sporulation gene 1), required for sporulation in Saccharomyces cerevisiae. Diploids homozygous for a disruption of GSG1 fail to sporulate. The gene has an open reading frame of 2094 bp, encoding a polypeptide with an expected size of 77 kDa. GSG1 is expressed mitotically in both a and α haploids, and both mitotically and meiotically in diploids. The message level of GSG1 increases approximately two‐fold after 4–6 h of sporulation. gsg1 mutants enter pre‐meiotic DNA synthesis later than wild‐type diploids. Mutant diploids are not rescued by spo13. These results suggest that GSG1 has a role late in meiosis following DNA replication. The sequence reported here has the GenBank Accession Number U26674.
A double flow cytometric tag allows tracking of the dynamics of cell cycle progression of newborn Saccharomyces cerevisiae cells during balanced exponential growth
Authors: Porro Danilo , Ranzi Bianca Maria , Smeraldi Carla , Martegani Enzo , Alberghina Lilia
Published: May 2005

Studies on the dynamics of growth of single eukaryotic cells and their relationships with cell cycle regulations are generally carried out following cell synchronization procedures or, on a relatively low number of cells, by time‐lapse studies. Establishment of both time‐lapse studies and synchronous cell populations usually requires elaborate experimental efforts and is prone to perturb the physiological state of the cell.

In this paper we use a new flow cytometric approach which allows, in asynchronous growing Saccharomyces cerevisiae populations, tagging of both the cell age and the cell protein content of a cohort of daughter cells at the different cell cycle set points. Since the cell protein content is a good estimation of the cell size, it is possible to follow the kinetics of the cell size increase during cell cycle progression. The experimental findings obtained indicate an exponential increase of the cell size during growth, that the daughter and the parent subpopulations grow with the same specific growth rate, that the average cell size increase rate of each individual cell is almost identical to the specific growth rate of the overall population and provide the opportunity to estimate the cell cycle length for the daughter cell population as well as the identification of the complex structure of asynchronously growing yeast populations.
VII. Yeast sequencing reports. The sequence of an 11·1 kb fragment on the left arm of Saccharomyces cerevisiae chromosome VII reveals six open reading frames including NSP49, KEM1 and four putative new genes
Authors: Bertani Iris , Coglievina Maristella , Zaccaria Paolo , Klima Raffaella , Bruschi Carlo V.
Published: May 2005

We report the sequence of an 11·1 kb fragment located on the left arm of chromosome VII of Saccharomyces cerevisiae. By sequence analysis we have detected six open reading frames (ORFs) longer than 300 bp, which cover 87% of the entire sequence. ORF G1645 is 100% identical to the KEM1 gene, also identified as DST2, XRN1, SEP1 and RAR5, while G1648 is 100% identical to the NSP49 or NUP49 gene. ORF G1642 shares some identity with a hypothetical protein of Caenorhabditis elegans, while the other four ORFs show no significant homology to known proteins. The sequence has been submitted to the EMBL data library under Accession Number X84705.
Yeast sequencing reports. Isolation of phosphoribosylpyrophosphate synthetase (PRS1) gene from Candida albicans
Authors: Payne Tracie L. , Calderone Richard A.
Published: May 2005

We have isolated a 3·7 kb EcoR1 fragment from a genomic library of Candida albicans which displayed a 65% level of identity with the PRS gene family (PRS) of Saccharomyces cerevisiae. The PRS gene encodes a phosphoribosylpyrophosphate (PRPP) synthetase of S. cerevisiae, which catalyses the synthesis of purines, pyrimidines, and amino acids such as histidine and tryptophan. By Northern analyses, we observed that the entire 3·7 kb EcoR1 fragment as well as a 1·1 kb KpnI‐SacI internal fragment of the 3·7 kb EcoR1 fragment hybridized to the same 1.4 kb transcript. An internal 2·6 kb KpnI fragment was subcloned and sequenced. A deduced sequence of 321 amino acids representing a polypeptide of 35·2 kDa was determined. A FASTA search indicated that the C. albicans PRS (Ca PRS1) had an overall homology at the amino acid level of 91% with the S. cerevisiae PRS3. Putative transcriptional start and termination sequences as well as a cation‐binding, PRPP synthetase signature sequence were identified. Ca PRS1 was localized to chromosome 2 of the C. albicans genome. Low stringency hybridizations indicates that the organism may possess multiple PRS genes. The function of these genes in nitrogen signaling is discussed. The Ca PRS1 sequence submitted to the EMBL data library is available under Accession Number U23934.
Analysis of copper‐induced metallothionein expression using autonomously replicating plasmids in Candida glabrata
Authors: Thorvaldsen Joanne L. , Mehra Rajesh K. , Yu Wei , Sewell Andrew K. , Winge Dennis R.
Published: May 2005

Candida glabrata strains and a stable plasmid were developed that were suitable for analysis of copper‐inducible expression from promoters of the three metallothionein (MT) genes. The two homologous MTII genes, MTIIa and MTIIb, encode the same polypeptide but are differentially induced by copper salts. MTIIb is more highly inducible than MTIIa and cells harboring a single MTIIb exhibit a greater resistance to copper salts compared to cells harboring a single MTIIa. The differential copper inducibility was mapped to sequences between − 503 and − 292 upstream of the MT coding sequences. Expression of MTI is highly Cu‐regulated, but this MT gene confers much less resistance than MTII genes.
XV. Yeast sequencing reports. Nucleotide sequence of the GDS1 gene of Saccharomyces cerevisiae
Authors: Konopinska Agata , Szczesniak Barbara , Boguta Magdalena
Published: May 2005

We have cloned and sequenced the GDS1 gene located on the right arm of chromosome XV of Saccharomyces cerevisiae. The gene codes for a 522 amino acid serine‐rich protein with no obvious homology to proteins in the database. GDS1 gene was isolated as the multicopy suppressor of the glycerol‐deficient phenotype caused by the nam9‐1 mutation in the yeast nuclear gene encoding the mitochondrial ribosomal protein homologous to S4 proteins from various organisms. Disruption‐deletion of the GDS1 open reading frame leads to a partial impairment of growth on medium containing glycerol as the carbon source, indicating mitochondrial function of the gene product. The sequence has been deposited in the GenBank data library under Accession Number U18262.
VII. Yeast sequencing reports. The sequence of an 11·1 kb DNA fragment between ADH4 and ADE5 on the left arm of chromosome VII reveals the presence of eight open reading frames
Authors: Vandenbol Micheline , Durand Patrick , Portetelle Daniel , Hilger Francois
Published: May 2005

The complete sequence of a 11,132 bp segment located on the left arm of chromosome VII of Saccharomyces cerevisiae has been determined and analysed. Eight open reading frames (ORFs) of at least 100 amino acids were identified. Five show similarities to known amino acid sequences. Another ORF encoding the chromosome segregation protein CSE1 is not entirely located in our sequenced fragment and is incomplete at its C‐terminus. The two remaining ORFs do not display similarities to known sequences. The sequence has been deposited in the EMBL Data Library under Accession Number Z49149.
Nutritional study of the Islanders on Tristan da Cunha, 1966
Authors: Margaret Chambers A. , Lewiss H. E.
Published: May 2005

1. Individual energy intakes and expenditures of seven Tristan men aged between 16 and 57 years, and ten Tristan women aged between 15 and 61 years, were measured daily for 7 consecutive days between May and October 1966.

2. Details of the subjects' main activities together with the energy cost of these activities are given.

3. The mean daily calorie intakes were 2650 kcal for men and 1830 kcal for women; the mean expenditures were 2860 and 2060 kcal per day respectively. Separate values are given for two individuals, a brother and sister, who gave results bearing no resemblance to those of the rest of the subjects.

4. Protein, fat, carbohydrate and alcohol accounted for 12.7, 29.6, 53.7 and 40 % respectively of the men's total calorie intake and 11.9, 27.2, 61.0% and 0% of the women's total calorie intake. The fat content of the diet was low when compared with that of the Islanders' diet while in England, though total calorie intake was greater (Taylor, Hollingsworth & Chambers, 1966). More than half the total calorie intake was provided by processed foodstuffs, but island produce provided a large proportion of the protein in the diet.

5. It is deduced that mean energy requirements of about 2750 kcal per day for men and 1950 kcal per day for women are adequate for the Tristan population and that there are sufficient food supplies available to meet this requirement.
Carbohydrate utilization in the pre-ruminant calf
Authors: Siddons R. C. , Smith R. H. , Henschel M. J. , Hill W. B. , Porter J. W. G.
Published: May 2005

1. Changes in blood sugar levels after giving carbohydrates have been used to assess carbohydrate utilization in pre-ruminant calves aged between 10 and 50 days.

2. Glucose, galactose and lactose were readily utilized by all calves; the utilization of glucose and galactose increased with age, whereas that of lactose remained constant.

3. Maltose and fructose utilization was low in young calves and increased slightly with age.

4. Sucrose and starch were not utilized.

5. Studies with three older pre-ruminant calves (aged 53, 88 and 106 days) in which the carbohydrates were infused into the proximal duodenum showed that glucose, galactose, lactose and xylose all caused marked increases in the level of blood reducing sugar, whereas fructose and sucrose caused no increase, and maltose was intermediate. Xylose and galactose caused very little change in the blood glucose concentration.

6. It appeared that preferential uptake occurred of glucose from a glucose-galactose mixture.

7. A non-linear relationship was found between the concentration of glucose or galactose infused and the increase in the level of blood reducing sugar.
The experimental production of zinc deficiency in the rat
Authors: Williams R. B. , Mills C. F.
Published: May 2005

1. Techniques for the preparation of a semi-synthetic basal diet suitable for the rapid production of zinc deficiency in the rat are described. The complete diet usually contains between 0.6 and 0.9 ppm Zn.

2. When the unsupplemented diet was fed to weanling rats, growth arrest occurred after 4–5 d; when supplemented with ZnSO4 to provide 12 or 20 ppm Zn, the rate of growth of rats was similar to that attained in animals given a conventional stock colony diet providing 83 ppm Zn. A study of relationships between dietary Zn concentration and weight gain in 21 d suggested that the Zn requirement of male and female rats for growth on this diet is approximately 12 ppm.

3. The development of Zn deficiency on diets providing < 1 or 3 ppm Zn was accompanied by poor food consumption and the development of a characteristic cyclic pattern of intake. A significant decline in the variability of daily food intake was observed when the diet was supplemented with Zn to provide 6, 9 or 12 ppm.

4. Studies of the influence of dietary Zn content upon changes in the Zn content of a range of tissues and upon whole-body Zn retention are reported.

5. The above findings are discussed in relation to the problem of defining the severity and duration of Zn deficiency in animals used for studies on the nature of the metabolic role of Zn.
The true absorption of cyst(e)ine from the ovine small intestine
Authors: Elliott R. , Little D. A.
Published: May 2005

1. Na234SO4 was infused into the rumen of a sheep fed a dried grass diet.

2. The digesta at the pylorus which contained 35S-labelled cyst(e)ine synthesized by the rumen microflora was collected and mixed with chromium EDTA. This material was infused into the duodenum of 35S free sheep.

3. Ileal digesta was subsequently collected and analysed for cyst(e)ine 35S and Cr.

4. The proportion of the labelled cyst(e)ine truly absorbed from the small intestine was 0.72±0.004.
Gene Expression and Microscopic Analysis of Arabidopsis Exposed to Chloroacetanilide Herbicides and Explosive Compounds. A Phytoremediation Approach
Authors: Mezzari Melissa P. , Walters Katherine , Jelínkova Marcela , Shih Ming-Che , Just Craig L. , Schnoor Jerald L.
Published: May 2005

Understanding the function of detoxifying enzymes in plants toward xenobiotics is of major importance for phytoremediation applications. In this work, Arabidopsis (Arabidopsis thaliana; ecotype Columbia) seedlings were exposed to 0.6 mm acetochlor (AOC), 2 mm metolachlor (MOC), 0.6 mm 2,4,6-trinitrotoluene (TNT), and 0.3 mm hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). In vivo glutathione (GSH) conjugation reactions of AOC, MOC, RDX, and TNT were studied in root cells using a multiphoton microscope. In situ labeling with monochlorobimane, used as a competitive compound for conjugation reactions with GSH, confirmed that AOC and MOC are conjugated in Arabidopsis cells. Reverse transcription-PCR established the expression profile of glutathione S-transferases (GSTs) and nitroreductases enzymes. Genes selected for this study were AtGSTF2, AtGSTU1, AtGSTU24, and two isoforms of 12-oxophytodienoate reductase (OPR1 and OPR2). The five transcripts tested were induced by all treatments, but RDX resulted in low induction. The mRNA level of AtGSTU24 showed substantial increase for all chemicals (23-fold induction for AOC, 18-fold for MOC, 5-fold for RDX, and 40-fold for TNT). It appears that GSTs are also involved in the conjugation reactions with metabolites of TNT, and to a lesser extent with RDX. Results indicate that OPR2 is involved in plant metabolism of TNT (11-fold induction), and in oxidative stress when exposed to AOC (7-fold), MOC (9-fold), and RDX (2-fold). This study comprises gene expression analysis of Arabidopsis exposed to RDX and AOC, which are considered significant environmental contaminants, and demonstrates the importance of microscopy methods for phytoremediation investigations.
Loss-of-Function Mutations in Chitin Responsive Genes Show Increased Susceptibility to the Powdery Mildew Pathogen Erysiphe cichoracearum
Authors: Ramonell Katrina , Berrocal-Lobo Marta , Koh Serry , Wan Jinrong , Edwards Herb , Stacey Gary , Somerville Shauna
Published: May 2005

Chitin is a major component of fungal walls and insect exoskeletons. Plants produce chitinases upon pathogen attack and chito-oligomers induce defense responses in plants, though the exact mechanism behind this response is unknown. Using the ATH1 Affymetrix microarrays consisting of about 23,000 genes, we examined the response of Arabidopsis (Arabidopsis thaliana) seedlings to chito-octamers and hydrolyzed chitin after 30 min of treatment. The expression patterns elicited by the chito-octamer and hydrolyzed chitin were similar. Microarray expression profiles for several genes were verified via northern analysis or quantitative reverse transcription-PCR. We characterized T-DNA insertion mutants for nine chito-oligomer responsive genes. Three of the mutants were more susceptible to the fungal pathogen, powdery mildew, than wild type as measured by conidiophore production. These three mutants included mutants of genes for two disease resistance-like proteins and a putative E3 ligase. The isolation of loss-of-function mutants with enhanced disease susceptibility provides direct evidence that the chito-octamer is an important oligosaccharide elicitor of plant defenses. Also, this study demonstrates the value of microarray data for identifying new components of uncharacterized signaling pathways.
l-Arginine attenuates cardiovascular impairment in DOCA-salt hypertensive rats
Authors: Fenning Andrew , Harrison Glenn , Rose’meyer Roselyn , Hoey Andrew , Brown Lindsay
Published: May 2005

Nitric oxide (NO) is essential for normal function of the cardiovascular system. This study has determined whether chronic administration of l-arginine, the biological precursor of NO, attenuates the development of structural and functional changes in hearts and blood vessels of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Uninephrectomized rats treated with DOCA (25 mg every 4th day sc) and 1% NaCl in the drinking water for 4 wk were treated with l-arginine (5% in food, 3.4 ± 0.3 g·kg body wt−1·day−1). Changes in cardiovascular structure and function were determined by echocardiography, microelectrode studies, histology, and studies in isolated hearts and thoracic aortic rings. DOCA-salt hypertensive rats developed hypertension, left ventricular hypertrophy with increased left ventricular wall thickness and decreased ventricular internal diameter, increased inflammatory cell infiltration, increased ventricular interstitial and perivascular collagen deposition, increased passive diastolic stiffness, prolonged action potential duration, increased oxidative stress, and inability to increase purine efflux in response to an increased workload. l-Arginine markedly attenuated or prevented these changes and also normalized the reduced efficacy of norepinephrine and acetylcholine in isolated thoracic aortic rings of DOCA-salt hypertensive rats. This study suggests that a functional NO deficit in blood vessels and heart due to decreased NO synthase activity or increased release of reactive oxygen species such as superoxide may be a key change initiating many aspects of the cardiovascular impairment observed in DOCA-salt hypertensive rats. These changes can be prevented or attenuated by administration of l-arginine.
Mechanical effects of muscle contraction do not blunt sympathetic vasoconstriction in humans
Authors: Kirby Brett S. , Markwald Rachel R. , Smith Erica G. , Dinenno Frank A.
Published: May 2005

Sympathetic vasoconstrictor responses are blunted in the vascular beds of contracting muscle (functional sympatholysis), but the mechanism(s) have been difficult to elucidate. We tested the hypothesis that the mechanical effects of muscle contraction blunt sympathetic vasoconstriction in human muscle. We measured forearm blood flow (Doppler ultrasound) and calculated the reductions in forearm vascular conductance (FVC) in response to reflex increases in sympathetic activity evoked via lower body negative pressure (LBNP). In protocol 1, eight young adults were studied under control resting conditions and during simulated muscle contractions using rhythmic forearm cuff inflations (20 inflations/min) with cuff pressures of 50 and 100 mmHg with the arm below heart level (BH), as well as 100 mmHg with the arm at heart level (HL). Forearm vasoconstrictor responses (%ΔFVC) during LBNP were −26 ± 2% during control conditions and were not blunted by simulated contractions (range = −31 ± 3% to −43 ± 6%). In protocol 2, eight subjects were studied under control conditions and during rhythmic handgrip exercise (20 contractions/min) using workloads of 15% maximum voluntary contraction (MVC) at HL and BH (similar metabolic demand, greater mechanical muscle pump effect for the latter) and 5% MVC BH alone and in combination with superimposed forearm compressions of 100 mmHg (similar metabolic demand, greater mechanical component of contractions for the latter). The forearm vasoconstrictor responses during LBNP were blunted during 15% MVC exercise with the arm at HL (−1 ± 3%) and BH (−2 ± 3%) compared with control (−25 ± 3%; both P < 0.005) but were intact during both 5% MVC alone (−24 ± 4%) and with superimposed compressions (−23 ± 4%). We conclude that mechanical effects of contraction per se do not cause functional sympatholysis in the human forearm and that this phenomenon appears to be coupled with the metabolic demand of contracting skeletal muscle.
Continuous positive airway pressure causes lung injury in a model of sepsis
Authors: Tsuchida Shinya , Engelberts Doreen , Roth Matthias , McKerlie Colin , Post Martin , Kavanagh Brian P.
Published: May 2005

Continuous positive airway pressure, aimed at preventing pulmonary atelectasis, has been used for decades to reduce lung injury in critically ill patients. In neonatal practice, it is increasingly used worldwide as a primary form of respiratory support due to its low cost and because it reduces the need for endotracheal intubation and conventional mechanical ventilation. We studied the anesthetized in vivo rat and determined the optimal circuit design for delivery of continuous positive airway pressure. We investigated the effects of continuous positive airway pressure following lipopolysaccharide administration in the anesthetized rat. Whereas neither continuous positive airway pressure nor lipopolysaccharide alone caused lung injury, continuous positive airway pressure applied following intravenous lipopolysaccharide resulted in increased microvascular permeability, elevated cytokine protein and mRNA production, and impaired static compliance. A dose-response relationship was demonstrated whereby higher levels of continuous positive airway pressure (up to 6 cmH2O) caused greater lung injury. Lung injury was attenuated by pretreatment with dexamethasone. These data demonstrate that despite optimal circuit design, continuous positive airway pressure causes significant lung injury (proportional to the airway pressure) in the setting of circulating lipopolysaccharide. Although we would currently avoid direct extrapolation of these findings to clinical practice, we believe that in the context of increasing clinical use, these data are grounds for concern and warrant further investigation.
Brain Signatures of Meaning Access in Action Word Recognition
Authors: Pulvermüller Friedemann , Shtyrov Yury , Ilmoniemi Risto
Published: May 2005

The brain basis of action words may be neuron ensembles binding language-and action-related information that are dispersed over both language-and action-related cortical areas. This predicts fast spreading of neuronal activity from language areas to specific sensorimotor areas when action words semantically related to different parts of the body are being perceived. To test this, fast neurophysiological imaging was applied to reveal spatiotemporal activity patterns elicited by words with different action-related meaning. Spoken words referring to actions involving the face or leg were presented while subjects engaged in a distraction task and their brain activity was recorded using high-density magnetoencephalography. Shortly after the words could be recognized as unique lexical items, objective source localization using minimum norm current estimates revealed activation in superior temporal (130 msec) and inferior frontocentral areas (142-146 msec). Face-word stimuli activated inferior frontocentral areas more strongly than leg words, whereas the reverse was found at superior central sites (170 msec), thus reflecting the cortical somatotopy of motor actions signified by the words. Significant correlations were found between local source strengths in the frontocentral cortex calculated for all participants and their semantic ratings of the stimulus words, thus further establishing a close relationship between word meaning access and neurophysiology. These results show that meaning access in action word recognition is an early automatic process reflected by spatiotemporal signatures of word-evoked activity. Word-related distributed neuronal assemblies with specific cortical topographies can explain the observed spatiotemporal dynamics reflecting word meaning access.
Tobit's Religious Universe Between Kinship Loyalty and the Law of Moses
Authors: Faßbeck Gabriele
Published: May 2005

The book of Tobit is among those Hellenistic period writings that convey a strong ideal of Jewish family life and family-centered religious practice. Tobit highly values family loyalty as a guideline for religious behavior, but establishes the Mosaic Law as the ultimate authority overruling requirements of family allegiance. In a world surrounded and threatened by Gentiles, the paterfamilias is responsible for redirecting the family's religious priorities to accord with the Law. Tobit displays close parallels with Jubilees in its use of the patriarchal stories to launch its pious message, which may help to situate the former within ancient Judaism.
Hypervariable region 1 variant acting as TCR antagonist affects hepatitis C virus-specific CD4+ T cell repertoire by favoring CD95-mediated apoptosis
Authors: Scottà Cristiano , Tuosto Loretta , Masci Anna Maria , Racioppi Luigi , Piccolella Enza , Frasca Loredana
Published: May 2005

We have described previously that hypervariable region 1 (HVR1) variants of hepatitis C virus (HCV) frequently act as T cell receptor (TCR) antagonists for HVR1-specific helper T cells. These naturally occurring HVR1-antagonistic sequences interfered with the effects of HVR1-agonistic sequences such as TCR down-regulation and early activatory signals. By taking advantage of these findings, in this paper, we have analyzed the fate of these HVR1-specific antagonized CD4+ T cells. We present the evidence that TCR antagonism renders agonist-activated T cells susceptible to bystander CD95-mediated killing by suppressing the expression of cellular Fas-associated death domain-like interleukin-1β-converting enzyme-like inhibitor proteins. To verify whether the TCR repertoire of a HVR1-specific T cell population could be modified consequently, we used a HVR1-agonistic sequence to induce in vitro CD4+ T cells and another HVR1 sequence with antagonistic property to mediate suppressive phenomena. HVR1-specific T cells were cultured with the agonist alone or with the agonist plus the antagonist. HVR1 specificity and T cell repertoires were followed over time by analyzing TCR β-variable gene segment by “spectratyping”. The results showed that the specificity for the agonist was rapidly spoiled after culture in the presence of the antagonist, and the TCR repertoire was strongly modified as a result of CD95-mediated apoptosis of agonist-specific clonal expansions. These data support the hypothesis that in HCV infection, the generation of TCR antagonists may reshape the T cell repertoire, representing an efficacious immune evasion strategy of a highly mutant pathogen.
ERK-mediated phosphorylation of Thr735 in TNFα-converting enzyme and its potential role in TACE protein trafficking
Authors: Soond Surinder M. , Everson Bethany , Riches David W. H. , Murphy Gillian
Published: May 2005

Tumor necrosis factor α-converting enzyme (TACE/ADAM17) has been implicated in the inducible shedding of numerous cell surface proteins. In light of this, the regulation of TACE catalytic activation and protein maturation has recently received considerable interest in the context of extracellular signal-regulated kinase activation and the subsequent phosphorylation of TACE at residue Thr735. In this study, we analysed the subcellular localisation of TACE derivatives using laser-scanning confocal microscopy and cell surface biotinylation. Whereas WT.TACE- and T735A.TACE-enhanced green fluorescent protein (-eGFP) fusion derivatives of TACE were both found to localise with the endoplasmic reticulum, a phosphomimicking form of TACE (T735E.TACE-eGFP) was found to colocalise predominantly with components of the protein secretory pathway (COPII vesicles and trans-Golgi network). Additionally, upon analysis of biotinylated ectopic TACE, we observed that inducible trafficking of TACE to the cell surface was dependent upon extracellular signal-regulated kinase activation and phosphorylation of Thr735. We conclude from our observations that phosphorylation of TACE at Thr735 highlights a key step in inducible TACE protein trafficking and maturation.
PfEMP1 expression is reduced on the surface of knoblessPlasmodium falciparuminfected erythrocytes
Authors: Horrocks Paul , Pinches Robert A. , Chakravorty Srabasti J. , Papakrivos Janni , Christodoulou Zóe , Kyes Susan A. , Urban Britta C. , Ferguson David J. P. , Newbold Chris I.
Published: May 2005

The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is a key virulence factor for this species of human malarial parasite. PfEMP1 is expressed on the surface of infected erythrocytes (IEs) and directly mediates adhesion to a variety of host cells. A number of other parasite-encoded proteins are similarly exported to the IE plasma membrane and play an indirect role in this adhesion process through the modification of the erythrocyte cytoskeleton and the formation of electron dense knobs into which PfEMP1 is anchored. Analysis of the specific contribution of knob-associated proteins to adhesion is difficult due to rapid PfEMP1 switching during in vitro culture. Furthermore, these studies typically assume that the level and distribution of PfEMP1 exposed in knobby (K+) and knobless (K–) IEs is unaltered, an assumption not yet supported with data. We describe here the preparation and characterisation of a panel of isogenic K+ and K– parasite clones that express one of two defined PfEMP1 variants. Analysis of the cytoadhesive properties of these clones shows that both static and flow adhesion is reduced in all the K– clones and, further, that this correlates with an approximately 50% reduction in PfEMP1 displayed on the IE surface. However, despite this reduction, the gross distribution of PfEMP1 in K– IEs appears unaltered. These data impact on our current interpretation of the role of knobs in adhesion and the mechanism of trafficking PfEMP1 to the IE surface.
DrosophilaCAP-D2 is required for condensin complex stability and resolution of sister chromatids
Authors: Savvidou Ellada , Cobbe Neville , Steffensen Søren , Cotterill Sue , Heck Margarete M. S.
Published: May 2005

The precise mechanism of chromosome condensation and decondensation remains a mystery, despite progress over the last 20 years aimed at identifying components essential to the mitotic compaction of the genome. In this study, we analyse the localization and role of the CAP-D2 non-SMC condensin subunit and its effect on the stability of the condensin complex. We demonstrate that a condensin complex exists in Drosophila embryos, containing CAP-D2, the anticipated SMC2 and SMC4 proteins, the CAP-H/Barren and CAP-G (non-SMC) subunits. We show that CAP-D2 is a nuclear protein throughout interphase, increasing in level during S phase, present on chromosome axes in mitosis, and still present on chromosomes as they start to decondense late in mitosis. We analysed the consequences of CAP-D2 loss after dsRNA-mediated interference, and discovered that the protein is essential for chromosome arm and centromere resolution. The loss of CAP-D2 after RNAi has additional downstream consequences on the stability of CAP-H, the localization of DNA topoisomerase II and other condensin subunits, and chromosome segregation. Finally, we discovered that even after interfering with two components important for chromosome architecture (DNA topoisomerase II and condensin), chromosomes were still able to compact, paving the way for the identification of further components or activities required for this essential process.
Paediatric otolaryngology services in the UK: a postal questionnaire survey of ENT consultants
Authors: Osman E Z , Aneeshkumar M K , Clarke R W
Published: May 2005

Approximately half a million children in England and Wales receive in-patient or day-case surgical treatment annually. Otolaryngology is the surgical specialty that provides the greatest number of episodes of such care. As 30–50 per cent of our total volume of work is paediatric, we feel it is important to assess current attitudes to paediatric otolaryngological practice. In its year 2000 document Children’s Surgery: a First Class Service, The Royal College of Surgeons (RCS) of England sets out recommendations on how children’s surgical services should be delivered in the UK. A postal questionnaire was sent to all UK-based ENT consultant members of the British Association of Otorhinolaryngologists-Head and Neck Surgeons (BAO-HNS). The questionnaire was designed to assess the current practice of paediatric otolaryngology in the UK with an emphasis on the RCS recommendations. Wide variations were found, and they are discussed with reference to the recommendations.
Initial presentation and fatal complications of linear IgA bullous dermatosis in the larynx and pharynx
Authors: Sato Katsuro , Hanazawa Hideyuki , Sato Yuichiro , Watanabe Jun , Takahashi Sugata
Published: May 2005

Two cases of linear IgA bullous dermatosis initially presenting as ulcerative lesions in the larynx and pharynx are reported. It was difficult to diagnose and treat the lesions, but they were finally diagnosed from the histopathological findings of accompanying skin lesion specimens. One of the patients required a tracheostomy due to increased airway stenosis by a laryngeal lesion. Despite general corticosteroid administration this could not be completely resolved, although partial opening of the glottis was observed, and the patient died of accidental tracheostomy tube complications during home care. Although there are no reports of this disease in the otolaryngological field, these rare diseases involving the skin and entire body should be considered in the differential diagnosis of laryngeal and pharyngeal ulcerative lesions, including airway stenosis. Furthermore, simple and safe procedures for relieving airway stenosis should be selected for rare and difficult-to-diagnose airway disease, prior to the final diagnosis.
Does Vasculogenic Mimicry Exist in Astrocytoma?
Authors: Yue Wei-Ying , Chen Zhong-Ping
Published: May 2005

Vasculogenic mimicry (VM) has been observed in melanoma and in some non-melanoma tumor types. It is unknown whether a similar VM phenomenon exists in astrocytoma. The present study was to examine 45 astrocytomas (including World Health Organization grade II 15 cases, grade III 15 cases, and grade IV 15 cases) by CD34 endothelial marker periodic acid-Schiff (PAS) dual staining to see if VM existing in these tumors. The results demonstrated that endothelium-lined vessels dominated the tumor microvasculature and stained positively for PAS, laminin, and endothelial marker. PAS-positive pattern of VM was found in two grade IV astrocytomas. Channels stained positively for PAS, laminin, and negatively for CD34 of the VM entrapped in the tumor tissue. Erythrocytes could be observed in some of these channels. In these networks of PAS-positive pattern, spots of weak reaction for CD34 were observed, suggesting the incorporation of VM channel and normal vessel. Furthermore, in astrocytoma, especially glioblastoma, focus of anaplastic tumor cells appeared with CD34 expression, whereas some tumor cells lost glial fibrillary acid protein expression. It is assumed that genetically deregulated tumor cells in astrocytoma could lose the astrocyte-specific protein and express inappropriate markers not expected in cells of astrocyte lineage. The present results suggest that VM phenomenon exists in some malignant astrocytoma.
Number and Distribution of Intraganglionic Laminar Endings in the Mouse Esophagus as Demonstrated with Two Different Immunohistochemical Markers
Authors: Raab M. , Neuhuber W.L.
Published: May 2005

Intraganglionic laminar endings (IGLEs) represent the only vagal mechanosensory terminals in the tunica muscularis of the esophagus. Two specific markers for IGLEs were recently described in mouse: the purinergic P2X2 receptor and the vesicular glutamate transporter 2 (VGLUT2). This study aimed at comparing both markers with respect to their suitability for quantitative analysis. We counted IGLEs immunostained for VGLUT2 and P2X2, respectively, and mapped their distribution in esophageal wholemounts of C57Bl/6 mice. Numbers and distribution of IGLEs were compared with those of myenteric ganglia as demonstrated by cuprolinic blue histochemistry. Whereas the distribution of VGLUT2-immunopositive IGLEs closely matched that of myenteric ganglia, P2X2-immunopositive IGLEs were rarely found in upper and middle esophagus but increasingly in its lower parts. P2X2 stained only half the number of IGLEs found with VGLUT2 immunostaining. We also investigated the correlation between anterograde tracing and immunohistochemistry for identifying IGLEs. Confocal microscopy revealed colocalization of all three markers in ∼50% of IGLEs. The remaining IGLEs showed only tracer and VGLUT2 labeling but no P2X2 immunoreactivity. Thus, VGLUT2 and P2X2 represent two specific markers for qualitative demonstration of esophageal IGLEs. However, VGLUT2 may be superior to P2X2 as a quantitative marker for IGLEs in the esophagus of C57Bl/6 mice.
Untersuchungen zum thermischen Abbau von Cellulose unter homogenen Reaktionsbedingungen
Authors: Lukanoff B. , Philipp B. , Schleicher H.
Published: May 2005

Untersuchungen zum homogenen thermischen Abbau unsubstituierter Cellulose wurden in Schmelzlösungen von Ca(SCN)2 · 3H2O, NaSCN/KSCN/DMSO und N‐Methylmorpholin‐N‐oxid (MMNO) im Temperaturbereich zwischen 80 und 170°C durchgeführt und mit Ergebnissen zum heterogenen thermischen Abbau im Faserverband verglichen. Unter Homogenbedingungen erfolgt die Kettenspaltung um etwa eine Größenordnung rascher als im Faserverband unter sonst vergleichbaren Bedingungen. In MMNO liegt offensichtlich ein komplexer Abbaumechanismus unter Beteiligung des Lösemediums bzw. seiner Zersetzungsprodukte vor.
Die Rolle von Diels‐Alder‐Reaktionen bei einigen radikalischen Polymerisationen
Authors: Sandner B.
Published: May 2005

Die Diels‐Alder‐Adduktbildung von Dien‐und Dienophilmonomer kann drei Elementarreaktionen der radikalischen Polymerisation bzw. Copolymerisation beeinflussen: Initiierungs‐, Wachstums‐und Kettenübertragungsreaktion. Der Monomerverbrauch durch Diels‐Alder‐Adduktbildung während der Polymerisation vermindert die Polymerausbeute. Die Diels‐Alder‐Addukte einiger aromatischer Diene reagieren mit einem dritten Monomermolekül unter Bildung polymerisationsauslösender Radikale und wirken gleichzeitig als starke kettenüberträger. Elektronendonator‐Acceptor‐Komplexe aus Dien und Dienophil sind als Zwischenstufe der Diels‐Alder‐Reaktion und der alternierenden Copolymerisation entsprechender Monomere von Bedeutung.
Untersuchungen zum Schmelzverhalten von copolyestern des Polytetramethylenterephthalats
Authors: Schaaf E. , Zimmermann H.
Published: May 2005

An einer Reihe statistischer Copolyester des Polytetramethylenterephthalats mit Sebacinsäure, Adipinsäure und Isophthalsäure konnte gezeigt werden, daß die Gleichung \documentclass{article}\pagestyle{empty}\begin{document}$\frac{1}{{T_m}} - \frac{1}{{T_m^0}} = \frac{R}{{\Delta H}}\left({\ln x_A - \left({1 - x_a} \right)} \right)$\end{document} eine gute Beschreibung der Beziehungen zwischen der Gleichgewichtsschmelztemperatur (Tm) und dem molaren Anteil der kristallisationsfähigen Komponente (xA) erlaubt. Das extrapolierte Ende der DTA‐Schmelzpeaks entspricht der Gleichgewichtsschmelztemperatur, die nach der Methode von Hoffman und Weeks bestimmt wurde, mit Abweichungen von 1 bis 2 K.
Bioactive polymers. XII. Immobilization of β‐amylase on cellulose acetate membranes grafted with acrylic acid
Authors: Simionescu C. I. , Brǎnişteanu S. , Dumitriu S.
Published: May 2005

Cellulose acetate‐g‐acrylic acid was prepared on which β‐amylase was immobilized by activation with dicyclohexylcarbodiimide. The amount of bound β‐amylase depends on the pH of the medium, reaction time and enzyme concentration. The Michaelis constant, determined for the starch substrate (pH = 6.5) is of 38.4 mmol which proves the decisive influence of the diffusion processes.
Synthesis and investigation of different‐unit structure m‐carborane‐containing polyamides
Authors: Korshak V. V. , Bekasova N. I. , Komarova L. G. , Surikova M. A.
Published: May 2005

The causes of the formation of chemically heterogeneous chains in different polyamides containing m‐carboranes were investigated and the effect of the heterogeneity on some properties of the polymers is examined.
Mikrofeine Polyolefin‐Pulver. 1. Mitt.: Über den einfluß des lösungsmittels, der konzentration der lösung und von nichtlöserzusätzen auf die pe‐pulvercharakteristik
Authors: Bischof C. , Herma H. , Gieseke R. , Schneider J. , Küchler H.
Published: May 2005

Die Bedingungen für die Herstellung mikrofeiner LDPE‐Pulver aus konzentrierten PE‐Lösungen werden untersucht. Der Einfluß wesentlicher Parameter wie Molmasse, Lösungsmittel, PE‐Konzentration, Abkühlgeschwindigkeit und Zusatz von Nichtlösern auf die Teilchenbildung und Pulvercharakteristik werden aufgezeigt. Die Möglichkeiten, sowohl die Ausbeute an Feinstkorn < 32 μ als auch die Teilchengrößenverteilung durch Variation der Versuchsparameter zu beeinflussen, werden diskutiert.
Texturuntersuchungen an Polyvinylidenfluorid (PVDF). Teil II. Untersuchungen zum Orientierungszustand einachsig gereckter PVDF‐folien der Modifikation II in Abhängigkeit von der Einwirkung eines elektrischen Feldes
Authors: Geiss D. , Ruscher Ch.
Published: May 2005

Der Orientierungszustand in einachsig gereckten PVDF‐Folien, deren geordnete Bereiche überwiegend aus der monoklinen Modifikation II bestehen, entspricht einem gemischten Texturtyp. Einer vorherrschenden Fasertextur ist ein uniplanarer Texturanteil überlagert. Dieser ist als Mehrfachtextur mit einer gleichzeitigen bevorzugten Ausrichtung der Netzebene (110) und (020) parallel zur Folienoberfläche ausgebildet. Als Folge einer elektrischen Feldeinwirkung werden sowohl Änderungen der kristallinen Struktur der geordneten Bereiche der Modifikation II als auch Änderungen des Orientierungszustandes nachgewiesen.
Head to head polymers. XXIX. A new synthetic route to poly(1,1‐dimethylpropane)
Authors: Malanga M. , Vogl O.
Published: May 2005

Poly(1,1‐dimethylpropane) was synthesized by Wurtz coupling polymerization. The polymer was of moderate molecular weight, about 50% crystalline, had a melting temperature of 87°C and a glass transition temperature of −17°C. The polymer was essentially the same material as that obtained by cationic hydride transfer polymerization of 3‐methylbutene‐1 at very low temperatures, or by cationic ring opening polymerization of 1,1‐dimethylcyclopropane. Poly(1,1‐dimethylpropane) obtained by the Wurtz reaction was obtained in only low yield; a substantial part of the total reaction product was 1,1‐dimethylcyclopropane.
Zur Feinstruktur von Ethylen‐Vinylacetat‐Copolymeren
Authors: Beyer D. , Lautner W. , Behrens H.
Published: May 2005

Während der Copolymerisation von Ethylen mit Vinylacetat werden Vinylacetat‐Einheiten in die Polyethylen‐Ketten eingebaut. Infolgedessen wird die Gitterzelle der Polyethylenstruktur aufgeweitet. Mit Hilfe der Röntgenweitwinkelstreuung wurde die Vergrößerung der Gitterparameter bestimmt. Auf der Grundlage dieser Veränderung der Gitterparameter wird ein Strukturmodell für Ethylen‐Vinylacetat‐Copolymere vorgeschlagen.
The chameleon dye 1,7‐bis(dimethylamino)heptamethine
Authors: Dähne Lars , Horvath Arpad , Weiser Gerhard , Reck Günter
Published: May 2005

The influence of the alignment and density of dye molecules on the spectroscopic properties of aggregates can be studied particularly well in J‐aggregates of 1,7‐bis(dimethylamino)heptamethine (BDH⊕). Four different arrangements of BDH⊕ molecules can be obtained without changing the molecular structure simply by using different counterions. The relationship between structure and linear spectroscopic properties—including the color of crystals containing BDH⊕–is discussed.
Efficient synthesis of starburst oxadiazole compounds
Authors: Bettenhausen Jörg , Strohriegl Peter
Published: May 2005

Starburst oxadiazole glasses are obtained by the reaction of aromatic tetrazoles with acid chlorides. The synthesis and thermal properties of these novel compounds are described. One of the glasses—unlike the others, which recrystallize when heated above their glass‐transition temperatures–is stable up to 350°C and is thus the first example of a stable amorphous molecular material with oxadiazole units. Low molecular weight organic compounds that form stable glasses are of interest for applications as photoconductors or light‐emitting devices.
Synthesis of a zeolite film on a mercury surface
Authors: Kiyozumi Yoshimichi , Mizukami Fujio , Maeda Kazuyuki , Toba Makoto , Niwa Shu‐ichi
Published: May 2005

Polycrystalline zeolite films–of great importance in catalysis, separation, and sensing—can be grown on various substrates, but in most cases there are problems in detaching the films. It is shown that a mercury surface accelerates the nucleation and crystallization of MFI‐type zeolites and that the surface of the film against the mercury (left in Figure) is smoother than that on the solution side (right in Figure).

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