bluuebunny/crossref_metadata_2025 huggingface dataset:
Cloning and chromosomal localization of the gene coding for human protein kinase CK1
Authors: Tapia Claudio , Featherstone Terence , Gómez Claudio , Taillon-Miller Patricia , Allende Catherine C. , Allende Jorge E.
Published: July 2002

A cDNA clone coding for human protein kinase CK1 (casein kinase 1) has been isolated and sequenced demonstrating that it corresponds to a homolog of the CK1α form found in bovine brain. The derived amino acid sequence of the human CK1α is identical to the bovine counterpart except that it contains 12 extra amino acids at the carboxyl end. Using this cDNA sequence and PCR amplification, YAC genomic clones that contain this human CK1α sequence have been isolated. These YACs have been used for fluorescent in situ hybridization in order to localize the human CK1α gene to chromosome 13q13.
Direct 1H NMR evidence for conversion of β‐d‐cellobiose to cellobionolactone by cellobiose dehydrogenase from Phanerochaete chrysosporium
Authors: Higham Christopher W. , Gordon-Smith Duncan , Dempsey Christopher E. , Wood Paul M.
Published: July 2002

The α‐ and β‐anomers of d‐cellobiose were resolved by 1H NMR spectroscopy. Addition of cellobiose dehydrogenase purified from the white‐rot P. chrysosporium led to selective conversion of β‐d‐cellobiose. The product was identical to cellobionolactone as synthesized from Ca‐cellobionate. Overnight incubation of the product led to an altered NMR spectrum, which was also obtained by incubation of cellobionolactone. The new spectrum matched that for Ca‐cellobionate. The instability of cellobionolactone explains the detection of cellobionic acid as product in earlier studies.
Existence of a new protein component with the same function as the LukF component of leukocidin or γ‐hemolysin and its gene in Staphylococcus aureus P83
Authors: Choorit Wanna , Kaneko Jun , Muramoto Koji , Kamio Yoshiyuki
Published: July 2002

Staphylococcal toxins, leukocidin and γ‐hemolysin, consist of two protein components, i.e. LukF and LukS for leukocodin and HγI and HγII for γ‐hemolysin. From a culture fluid of Staphylococcus aureus strain P83, a new protein component of leukocidin or γ‐hemolysin which was designated as LukM was isolated. This component showed the same biological activity as that of LukF component for leukocidin or HγI component of γ‐hemolysin in combination with LukS or HγII. However, the LukM component cross‐reacted with the anti‐LukS antibodies but not with the anti‐LukF antibodies. On the basis of chemical analysis of the LukM component and the cloning and nucleotide sequencing of the lukM gene of S. aureus P83, we have demonstrated that LukM is an entirely new protein component of leukocidin or γ‐hemolysin. The deduced amino acid sequence of LukM from the lukM gene showed 66.7% and 67% indentity to that of LukS and Hγll, respectively. However, the amino acid sequence of LukM and LukF showed only 29% homology.
Expression of α‐1,3 linkage‐containing oligomannosyl residues in a cell‐wall mannan of Candida tropicalis grown in yeast extract‐Sabouraud liquid medium under acidic conditions
Authors: Kobayashi Hidemitsu , Shibata Nobuyuki , Suzuki Akifumi , Takahashi Shin-ichi , Suzuki Masako , Matsuda Kyoko , Hisamichi Kanehiko , Suzuki Shigeo
Published: July 2002

We investigated the cell‐wall mannan obtained from Candida tropicalis IFO 1647 strain cells grown in yeast extract‐Sabouraud medium at pH 3.0 by two‐dimensional homonuclear Hartmann‐Hahn spectroscopy. The results indicate that the phosphate group and the side chains containing a β‐1,2‐linked mannopyranose unit decreased compared to those of mannan from cells grown under conventional conditions (pH 5.9) with concomitant expression of α‐1,3 linkage‐containing oligomannosyl side chains. The results of acetolysis of these mannans indicated that the presence of α‐1,3‐linked mannopyranose unit existed in side chains corresponding to pentaose and hexaose, Manpα1‐3Manpα1‐2Manpα1‐2Manpα1‐2Man, and Manpα1‐2Manpα1‐3Manpα1‐2Manpα1‐2Manpα1‐2Man, in the mannan from cells grown at pH 3.0.
Electrons generated by photosystem II are utilized by an oxidase in the absence of photosystem I in the cyanobacterium Synechocystis sp. PCC 6803
Authors: Vermaas Wim F.J. , Shen Gaozhong , Styling Stenbjörn
Published: July 2002

The reduction and reoxidation kinetics of the first quinone‐type electron acceptor in photosystem II, QA
−, were measured by fluorescence in a light‐tolerant, photosystem I‐less strain of the cyanobacterium Synechocystis sp. PCC 6803. In this strain, which shows excellent amplitudes of variable fluorescence, the rate of QA
− oxidation after photoreduction of the plastoquinone pool was about half of that in the presence of photosystem I. However, upon addition of 5 mM KCN, QA
− decay was very slow, and the rate was comparable to that seen in the presence of diuron, which blocks electron transport between QA and QB. The KCN‐imposed block of QA
− oxidation was removed efficiently by addition of exogenous quinones that can oxidize the plastoquinone pool. These results indicate that, in the absence of photosystem I, photosystem II‐generated electrons are used very effectively by an oxidase located in the thylakoid; this oxidase may be a component of the respiratory chain.
Cytotoxic and chemotactic potencies of several aldehydic components of oxidised low density lipoprotein for human monocyte‐macrophages
Authors: Müller Karin , Hardwick Simon J. , Marchant Christine E. , Law Nadine S. , Waeg Georg , Esterbauer Hermann , Carpenter Keri L.H. , Mitchinson Malcolm J.
Published: July 2002

We have investigated the cytotoxic and chemotactic potencies of malondialdehyde (MDA), hexanal, 4‐hydroxyhexenal (HHE), 4‐hydroxynonenal (HNE) and 4‐hydroxyoctenal (HOE), which are aldehydes found in oxidised low density lipoprotein (LDL), for human monocyte‐macrophages. They were toxic in the following order: hexanal < HHE = HOE < HNE. HNE was toxic at 20 μM and chemotactic at 2.5 μM. The other aldehydes tested had no chemoattractant activity. Our results suggest that HNE arising from LDL oxidation could attract monocytes into the human atherosclerotic lesion. A direct cytotoxic role of aldehydes in foam cell death in the lesion is less likely.
Differential illness intrusiveness associated with sleep-promoting medications
Authors: Devins GM , Flanigan M , Fleming JAE , Morehouse R , Moscovitch A , Plamondon J , Reinish L , Shapiro CM
Published: July 2002

Differences in daytime sleepiness, lifestyle disruptions, and emotional distress were compared across nine groups taking sleep-promoting substances. Groups included individuals taking zopiclone (n = 274), amitriptyline (n = 107), lorazepam (n = 258), oxazepam (n= 141), diphenhydramine HCl (n = 99), triazolam(n = 137), long acting benzodiazepines (n = 120), temazepam (n = 176), and miscellaneous other medications (n = 286). Data were gathered by self-report, using standardized instruments in a mail-back questionnaire procedure. Respondents included the first 1,598 participants enrolled in a Canadian multicentre project, including six sites attached to academic psychiatric units. Results indicated that quality of life effects differed across groups in both daytime sleepiness and lifestyle disruptions (illness intrusiveness), but not in depressive symptoms. Daytime sleepiness was significantly higher among people taking diphenhydramine HCl as compared to temazepam, zopiclone, lorazepam, and oxazepam. Illness intrusiveness was significantly higher among patients taking amitriptyline as compared to those taking triazolam, oxazepam, long-acting benzodiazepines, and zopiclone. It may be useful to inform patients of differences in psychosocial outcomes when prescribing hypnotic medications.
The molecular chaperone Cdc37 is required for Ste11 function and pheromone‐induced cell cycle arrest
Authors: Abbas-Terki Toufik , Donzé Olivier , Picard Didier
Published: July 2002

The molecular chaperone Cdc37 is thought to act in part as a targeting subunit of the heat‐shock protein 90 (Hsp90) chaperone complex. We demonstrate here that Cdc37 is required for activity of the kinase Ste11 in budding yeast. A cdc37 mutant strain is defective in Ste11‐mediated pheromone signaling and in accumulation and functional maturation of the constitutively active Ste11 version Ste11ΔN. Moreover, Cdc37, Ste11ΔN and Hsp90 coprecipitate pairwise. Thus, Hsp90 and Cdc37 may transiently associate with Ste11 to promote proper folding and/or association with additional regulatory factors. Our results establish Ste11 as the first endogenous Cdc37 client protein in yeast.
Analysis of gastrin receptor gene expression in proliferating cells in the neck zone of gastric fundic glands using laser capture microdissection
Authors: Kazumori Hideaki , Ishihara Shunji , Kawashima Kousaku , Fukuda Ryo , Chiba Tsutomu , Kinoshita Yoshikazu
Published: July 2002

Gastrin stimulates proliferation of progenitor cells in the neck zone of gastric fundic mucosa. However, whether it directly enhances this proliferation through its receptors remains unclear. We investigated the expression of gastrin receptors in neck zone proliferating cells in rat gastric fundic glands using a reverse transcription polymerase chain reaction (RT‐PCR) coupled with laser capture microdissection and in situ RT‐PCR. Gastrin receptor expression was identified in c‐fos‐expressing cells located in the neck zone, and results of the RT‐PCR analysis argued against contamination by other cells, such as enterochromaffin‐like, parietal or D cells. Supporting this finding, gastrin receptor gene expression was identified in the neck zone as well as base glands by in situ RT‐PCR. Therefore, it is suggested that proliferating cells in the neck zone are stimulated directly by gastrin via their gastrin receptors.
Polyethylene glycol induces apoptosis in HT‐29 cells: potential mechanism for chemoprevention of colon cancer
Authors: Roy Hemant K , DiBaise John K , Black John , Karolski William J , Ratashak Anne , Ansari Sajid
Published: July 2002

Recent experimental evidence suggests that polyethylene glycol (PEG) is a highly effective chemopreventive agent against colon cancer; however, the mechanism(s) remain largely unexplored. To further elucidate this issue, we evaluated the effect of PEG on two human colon cancer cell lines. PEG treatment resulted in a dose‐ and time‐dependent reduction in cell number without alteration in markers of cell proliferation. However, there was a dramatic and specific, concentration‐dependent induction of apoptosis, with 50 mM PEG rendering approximately half the cells apoptotic. This corresponded with a 17‐fold induction in the expression of the pro‐apoptotic protein, prostate apoptosis response‐4. Our data suggest that induction of apoptosis may be responsible, at least in part, for the ability of PEG to prevent experimental colon cancer.
Inhibition of Src by direct interaction with protein phosphatase 2A
Authors: Yokoyama Noriko , Miller W.Todd
Published: July 2002

In this study, we report that Src kinase is inhibited by protein phosphatase 2A (PP2A), a serine/threonine phosphatase. We carried out experiments in vitro using purified PP2A (AC dimer) and full‐length v‐Src or truncated forms of v‐Src. The inhibition of v‐Src by PP2A is concentration‐ and time‐dependent. Addition of okadaic acid, a PP2A phosphatase inhibitor, abolished the PP2A‐dependent inhibition of v‐Src. When experiments were carried out at 4°C under conditions where PP2A activity is inhibited, Src activity was unaffected by the presence of PP2A, suggesting that PP2A binding alone is insufficient to block Src activity. These results imply that PP2A activity is essential for inhibition of v‐Src. We also demonstrate that PP2A binds to the catalytic and the regulatory domains of v‐Src.
Role of the N‐terminus in the structure and stability of chicken annexin V
Authors: Arboledas David , Olmo Nieves , Lizarbe Mª Antonia , Turnay Javier
Published: July 2002

The role of the short N‐terminal region of chicken annexin V in the maintenance of the protein structure and its influence in the conformation of the calcium binding regions was analyzed. The N‐terminal domain is not essential for protein folding, wild‐type and dnt‐annexin V showing almost identical secondary structures. However, the partial truncation of the N‐terminus significantly decreases the melting temperature of the protein and induces the partial exposure of Trp187 which is normally located in a hydrophobic pocket of the calcium binding region of domain 3 of annexin V in the Ca2+‐free form.
Activation of mitogen‐activated protein kinase is involved in sphingosine 1‐phosphate‐stimulated interleukin‐6 synthesis in osteoblasts
Authors: Kozawa Osamu , Tokuda Haruhiko , Matsuno Hiroyuki , Uematsu Toshihiko
Published: July 2002

We previously showed that sphingosine 1‐phosphate (SPP) acts as a second messenger for tumor necrosis factor α‐induced interleukin‐6 (IL‐6) synthesis in osteoblast‐like MC3T3‐E1 cells. In the present study, we further investigated the mechanism of IL‐6 synthesis induced by SPP in MC3T3‐E1 cells. SPP significantly induced p42/p44 mitogen‐activated protein (MAP) kinase activity. PD98059, an inhibitor of MAP kinase kinase, suppressed SPP‐induced IL‐6 synthesis as well as SPP‐induced MAP kinase activation. The patterns of both inhibitions were similar. TMB‐8, an inhibitor of Ca2+ mobilization from intracellular Ca2+ stores, significantly suppressed the SPP‐induced IL‐6 synthesis. These results strongly suggest that SPP‐induced IL‐6 synthesis is mediated via p42/p44 MAP kinase activation in osteoblast‐like cells and that the SPP‐induced IL‐6 synthesis is dependent on intracellular Ca2+ mobilization.
β1B subunit of voltage‐dependent Ca2+ channels is predominant isoform expressed in human neuroblastoma cell line IMR32
Authors: McEnery Maureen W , Haase Hannelore , Vance Courtney L , Dubel Stefan J , Morano Ingo , Copeland Terry D , Choi Yunsook
Published: July 2002

Human neuroblastoma cells (IMR32) respond to treatment with either dibutyryl‐cAMP or nerve factor by acquiring a neuronal phenotype which is accompanied by a marked increase in the density of neuronal (N‐type) VDCC currents. Using IMR32 cells as a model for neuronal differentiation, we were interested in examining possible changes in the level of expression of the α1B subunit of N‐type calcium channels as well as beta subunit isoforms. Upon differentiation with dibutyryl‐cAMP and 5‐bromo‐2‐deoxyuridine for 16 days, we observed a dramatic increase in α1B protein which initiated between day 8 and 10. Day 10 evidenced maximal expression of α1B protein, which was followed by an interval of relatively constant expression of α1B (day 12 to day 16). Monitoring beta subunit expression using a pan specific anti‐beta antibody (Ab CW20), we observed an increase in expression of a single 82 kDa beta subunit. The predominant 82 kDa beta subunit expressed throughout the course of differentiation was identified as the β1b isoform using a panel of beta subunit specific antibodies. Of significance, neither the β2 nor β3 isoforms were detected in full differentiated IMR32 cells. Contrary to a previous report on the absence of neurotypic expression of VDCC beta subunits in a second model for in vitro differentiation, NGF‐treated rat pheochromocytoma cells (PC12 cells) [1], we report the regulated expression of the β1b protein in differentiated IMR32 cells suggesting a cell specific function for this beta subunit which parallels the acquisition of the neuronal phenotype. The restrictive expression of the β1b in IMR32 cells may reflect a cell‐type specific function that extends beyond its role as an auxiliary subunit of VDCC complexes.
Ectopic expression of Nramp1 in COS‐1 cells modulates iron accumulation
Authors: Atkinson Peter G.P , Barton C.Howard
Published: July 2002

Nramp1 (natural resistance‐associated macrophage protein) controls innate immunity and encodes a transporter of unknown function. Here we describe an antibody to Nramp1 displaying immunoreactivity towards a mature heavily glycosylated polypeptide of 90–100 kDa and a precursor form of 45 kDa in macrophages. Ectopic expression of the Nramp1 cDNA in COS‐1 cells demonstrates that Nramp1 modulates cellular iron levels following loading with low molecular weight iron chelates. Surprisingly, Nramp1 does not enhance iron uptake, but expression is associated with reduced cellular iron loads. We propose Nramp1 may play a role in a salvage pathway of iron recycling.
Orientation of antigen binding sites in dimeric and trimeric single chain Fv antibody fragments
Authors: Lawrence Lynne J. , Kortt Alexander A. , Iliades Peter , Tulloch Peter A. , Hudson Peter J.
Published: July 2002

Electron microscopy of dimeric and trimeric single chain antibody Fv fragments (scFvs) complexed with anti‐idiotype Fab fragments was used to reveal the orientation of antigen binding sites. This is the first structural analysis that discloses the multivalent binding orientation of scFv trimers (triabodies). Three different scFv molecules were used for the imaging analysis; NC10 scFv‐5 and scFv‐0, with five‐ and zero‐residue linkers respectively between the VH and VL domains, were complexed with 3‐2G12 anti‐idiotype Fab fragments and 11‐1G10 scFv‐0 was complexed with NC41 anti‐idiotype Fab fragments. The scFv‐5 molecules formed bivalent dimers (diabodies) and the zero‐linker scFv‐0 molecules formed trivalent trimers (triabodies). The images of the NC10 diabody‐Fab complex appear as boomerangs, not as a linear molecule, with a variable angle between the two Fab arms and the triabody‐Fab complexes appear as tripods.
Identification of a dynein molecular motor component in Torpedo electroplax; binding and phosphorylation of Tctex‐1 by Fyn1
Authors: Mou Tao , Kraas Jonathan R. , Fung Eric T. , Swope Sheridan L.
Published: July 2002

The microtubule protein Tctex‐1 was cloned from Torpedo electroplax, a biochemical model of the neuromuscular junction, using the unique domain of Fyn in the yeast two hybrid system. Binding of Tctex‐1 and Fyn also occurred in vitro. Torpedo Tctex‐1 was contained within the molecular motor protein dynein. A Src class kinase was also complexed with dynein. Tctex‐1 was enriched in electric organ vs. skeletal muscle, was present in the postsynaptic membrane, and coprecipitated with the acetylcholine receptor. The sequence of Tctex‐1 contained a tyrosine phosphorylation motif and Tctex‐1 could be phosphorylated by Fyn in vitro and in vivo. These data demonstrated that Tctex‐1‐containing dynein is a cytoskeletal element at the acetylcholine receptor‐enriched postsynaptic membrane and suggested that Tctex‐1 may be a substrate for Fyn.
The role of DnaK/DnaJ and GroEL/GroES systems in the removal of endogenous proteins aggregated by heat‐shock from Escherichia coli cells
Authors: Kędzierska S. , Staniszewska M. , Węgrzyn A. , Taylor A.
Published: July 2002

The submission of Escherichia coli cells to heat‐shock (45°C, 15 min) caused the intracellular aggregation of endogenous proteins. In the wt cells the aggregates (the S fraction) disappeared 10 min after transfer to 37°C. In contrast, the S fraction in the dnaK and dnaJ mutant strains was stable during approximately one generation time (45 min). This demonstrated that neither the renaturation nor the degradation of the denatured proteins was possible in the absence of DnaK and DnaJ. The groEL44 and groES619 mutations stabilised the aggregates to a lesser extent. It was shown by the use of cloned genes, dnaK/dnaJ or groEL/groES, producing the corresponding proteins in about 4‐fold excess, that the appearance of the S fraction in the wt strain resulted from a transiently insufficient supply of the heat‐shock proteins. Overproduction of the GroEL/GroES proteins in dnaK756 or dnaJ259 background prevented the aggregation, however, overproduction of the DnaK/DnaJ proteins did not prevent the aggregation in the groEL44 or groES619 mutant cells although it accelerated the disappearance of the aggregates. The properties of the aggregated proteins are discussed from the point of view of their competence to renaturation/degradation by the heat‐shock system.
Differential effects of retinoic acid isomers on the expression of nuclear receptor co‐regulators in neuroblastoma
Authors: Lovat Penny E , Annicchiarico-Petruzzelli Margherita , Corazzari Marco , Dobson Mark G , Malcolm Archie J , Pearson Andy D.J , Melino Gerry , Redfern Christopher P.F
Published: July 2002

Retinoic acid modulates growth and induces differentiation and apoptosis of neuroblastoma cells in vitro, with the all‐trans and 9‐cis isomers having different biological properties. Transcriptional activation in response to retinoic acid isomers is mediated by retinoic acid receptors and retinoid X receptors. The differential expression of co‐activators and co‐repressors which preferentially interact with retinoic acid receptors or retinoid X receptors may be a mechanism leading to different cellular responses to 9‐cis and all‐trans retinoic acid. To test this hypothesis, we have studied the expression of the nuclear receptor co‐regulators TIF1α, TIF1β, SUG1 and SMRT in the N‐type and S‐type neuroblastoma cell lines SH SY 5Y and SH S EP. Transcripts for all four co‐regulators were expressed in these neuroblastoma cells. The expression of TIF1α, TIF1β and SUG1 did not change in response to retinoic acid; however, SMRT was induced in both neuroblastoma cell lines, but particularly by all‐trans retinoic acid in SH S EP cells. An additional co‐activator, Trip3, was isolated by differential mRNA display and shown to be preferentially induced by 9‐cis retinoic acid in SH SY 5Y and SH S EP cells. These data suggest that retinoic acid isomer‐specific induction of nuclear receptor co‐regulators may determine, in part, the differential biological effects of retinoic acid isomers.
The presumed potassium carrier Trk2p in Saccharomyces cerevisiae determines an H+‐dependent, K+‐independent current
Authors: Bihler Hermann , Gaber Richard F , Slayman Clifford L , Bertl Adam
Published: July 2002

Ionic currents related to the major potassium uptake systems in Saccharomyces cerevisiae were examined by whole cell patch‐clamping, under K+ replete conditions. Those currents have the following properties. They (1) are inward under all conditions investigated, (2) arise instantaneously with appropriate voltage steps, (3) depend solely upon the moderate affinity transporter Trk2p, not upon the high affinity transporter Trk1p. They (4) appear to be independent of the extracellular K+ concentration, (5) are also independent of extracellular Ca2+, Mg2+ and Cl− but (6) are strongly dependent on extracellular pH, being large at low pH (up to several hundred pA at −200 mV and pH 4) and near zero at high pH (above 7.5). They (7) increase in proportion to log[H+]o, rather than directly in proportion to the proton concentration and (8) behave kinetically as if each transporter cycle moved one proton plus one (high pH) or two (low pH) other ions, as yet unidentified. In view of background knowledge on K+ transport related to Trk2p, the new results suggest that the K+ status of yeast cells modulates both the kinetics of Trk2p‐mediated transport and the identity of ions involved. That modulation could act either on the Trk2 protein itself or on interactions of Trk2 with other proteins in a hypothetical transporter complex. Structural considerations suggest a strong analogy to the KtrAB system in Vibrio alginolyticus and/or the TrkH system in Escherichia coli.
Subcellular localization and partial purification of prelamin A endoprotease: an enzyme which catalyzes the conversion of farnesylated prelamin A to mature lamin A
Authors: Kilic Fusun , Johnson David A , Sinensky Michael
Published: July 2002

The nuclear lamina protein, lamin A is produced by proteolytic cleavage of a 74 kDa precursor protein, prelamin A. The conversion of this precursor to mature lamin A is mediated by a specific endoprotease, prelamin A endoprotease. Subnuclear fractionation indicates that the prelamin A endoprotease is localized at the nuclear membrane. The enzyme appears to be an integral membrane protein, as it can only be removed from the nuclear envelope with detergent. It is effectively solubilized by the detergent n‐octyl‐β‐D‐glucopyranoside and can be partially‐purified (∼1200‐fold) by size exclusion and cation exchange (Mono S) chromatography. Prelamin A endoprotease from HeLa cells was eluted from Mono S with 0.3 M sodium chloride as a single peak of activity. SDS‐PAGE analysis of this prelamin A endoprotease preparation shows that it contains one major polypeptide at 65 kDa and smaller amounts of a second 68 kDa polypeptide. Inhibition of the enzyme activity in this preparation by specific serine protease inhibitors is consistent with the enzyme being a serine protease.
Predicting the protein folding nucleus from a sequence
Authors: Poupon Anne , Mornon Jean-Paul
Published: July 2002

Understanding the mechanism of protein folding would allow prediction of the three‐dimensional structure from sequence data alone. It has been shown that small proteins fold in a small number of kinetic steps and that significantly populated intermediate states exist for some of them. Studies of these intermediates have demonstrated the existence of specific interactions established during the initial stages of folding. Comparison of the amino acids participating in these specific and essential interactions and constituting the folding nucleus with conserved hydrophobic positions of a given fold shows a striking correspondence. This finding opens the perspective of predicting the folding nucleus knowing only a set of divergent sequences of a protein family.
Cytokine‐inducible CD40 gene expression in vascular smooth muscle cells is mediated by nuclear factor κB and signal transducer and activato of transcription‐1
Authors: Krzesz Robert , Wagner Andreas H. , Cattaruzza Marco , Hecker Markus
Published: July 2002

The interaction of T‐lymphocytes expressing the CD40 ligand (CD154) and cells of the vessel wall expressing the corresponding receptor protein (CD40) may play an important role in chronic inflammation including arteriosclerosis. One way of interfering with CD40‐CD154 signalling is to prevent CD40 expression, the regulation of which, however, has yet to be elucidated. Therefore, we studied CD40 expression in rat aortic cultured smooth muscle cells. Both CD40 mRNA and protein expression in these cells was markedly enhanced as early as 6 h after exposure to different pro‐inflammatory cytokines. Experiments with actinomycin D and subsequent run‐on analyses revealed that CD40 expression in response to these cytokines was regulated at the level of transcription. Moreover, electrophoretic mobility shift analyses along with the employment of transcription factor decoy oligodeoxynucleotides demonstrated that tumor necrosis factor α via nuclear κB and interferon‐γ via signal transducer and activator of transcription‐1 up‐regulate CD40 gene expression in rat aortic cultured smooth muscle cells.
Reversal of mitochondrial Na/Ca exchange during metabolic inhibition in rat cardiomyocytes
Authors: Griffiths Elinor J
Published: July 2002

During hypoxia of isolated cardiomyocytes, Ca2+ entry into mitochondria may occur via the Na/Ca exchanger, the normal efflux pathway, and not the Ca‐uniporter, the normal influx route. If this is the case, then depletion of myocyte Na+ should inhibit Ca2+ uptake, and collapse of the mitochondrial membrane potential (Δψm) would inhibit the uniporter. To test these hypotheses, isolated rat myocytes were exposed to metabolic inhibition, to mimic hypoxia, and [Ca2+]m and [Ca2+]c determined by selective loading of indo‐1 into these compartments. Δψm was determined using rhodamine 123. Following metabolic inhibition, [Ca2+]m was significantly lower in Na‐depleted cells than controls (P<0.001), [Ca2+]c was approximately the same in both groups, and mitochondria depolarised completely. Thus Na‐depletion inhibited mitochondrial Ca2+ uptake, suggesting that Ca2+ entry occurred via Na/Ca exchange, and the collapse of Δψm during metabolic inhibition is consistent with inactivity of the Ca‐uniporter.
Evidence for tissue‐specific forms of glutaminyl cyclase
Authors: Sykes Paul A , Watson Stephanie J , Temple Jeffrey S , Bateman Robert C
Published: July 2002

Glutaminyl cyclase (QC) is responsible for the presence of pyroglutamyl residues in many neuroendocrine peptides. An examination of the bovine tissue distribution of QC immunoreactivity, enzyme activity, and mRNA confirmed that QC was abundant in brain and pituitary by all three measures. However, enzymatic activity was considerably more widespread than either immunoreactivity or mRNA, suggesting multiple enzyme forms. Partially purified QC from bovine spleen differed significantly from the known bovine pituitary QC in physical and catalytic properties. We propose that this form of glutaminyl cyclase plays a role in the posttranslational processing of constitutively secreted pGlu‐containing proteins.
The ubiquitous transcription factor NF‐Y positively regulates the transcription of human p27Kip1 through a CCAAT box located in the 5′‐upstream region of the p27Kip1 gene
Authors: Kamiyama Jun , Inoue Toshiaki , Ohtani-Fujita Naoko , Minami Shinji , Yamagishi Hisakazu , Sakai Toshiyuki
Published: July 2002

Abnormally low levels of the cyclin‐dependent kinase inhibitor p27Kip1 are found frequently in human carcinomas, and these levels correlate directly with both histological aggressiveness and patient mortality. p27Kip1 is haplo‐insufficient for tumor suppression. Thus, p27Kip1 may be a useful molecule for the development of cancer therapies. To know the possible mechanisms underlying transcriptional control, we previously cloned the promoter region of human p27Kip1 gene. We report here the characterization of the 5′‐regulatory region of the human p27Kip1 gene. Promoter analysis using 5′‐deletion mutants revealed that a 39‐bp region between −549 and −511 was required for maximal promoter activity. Point mutation analysis revealed that a CCAAT box within this region was essential for promoter activity. Gel shift assays and cotransfection experiments using a dominant negative form of the NF‐Y transcription factor showed that NF‐Y directly regulates p27Kip1 transcription through this CCAAT box. This finding might provide a clue to approach the mechanism of tumorigenesis.
Vascular cell adhesion molecule‐1 (VCAM‐1) and leukocyte activation in pre‐eclampsia and eclampsia
Authors: Budak E , Madazli R , Aksu M.F , Benian A , Gezer A , Palit N , Yildizfer F
Published: July 2002

Objective: To evaluate the levels of VCAM‐1 in pre‐eclampsia/eclampsia as a possible marker of leukocyte activation and endothelial damage. Methods: We performed a case‐control study on 25 healthy pregnant women and 35 patients diagnosed as pre‐eclampsia or eclampsia which were randomly selected. Peripheral venous blood samples were obtained and serum levels of VCAM‐1 were measured by enzyme‐linked immunoassay (ELISA). Results: In pre‐eclampsia/eclampsia, VCAM‐1 levels were higher than in normal pregnancy. Serum concentrations of VCAM‐1 were significantly higher in severe pre‐eclampsia and eclampsia compared to mild pre‐eclampsia or healthy controls. ROC analysis detected that VCAM‐1 ≥450 ng/ml had a sensitivity of 0.79 and a specificity of 0.90 in detecting severe pre‐eclampsia and eclampsia. Conclusion: This is the first study to correlate VCAM‐1 levels with severity of disease in pre‐eclampsia. Our findings indicate that increasing levels of soluble VCAM‐1 are present in the circulation of patients with severe pre‐eclampsia/eclampsia compared to mild pre‐eclampsia or healthy pregnant women. Elevated VCAM‐1 levels may represent a possible mechanism by which endothelial cells attract leukocytes and cause endothelial cell damage.
Extinction: End‐Triassic Mass Extinction
Authors: Hautmann Michael
Published: July 2021

One of the five greatest mass extinction events in Earth's history occurred at the end of the Triassic,c. 200 million years ago. This event ultimately eliminated conodonts and nearly annihilated corals, sphinctozoan sponges and ammonoids. Other strongly affected marine taxa include brachiopods, bivalves, gastropods and foraminifers. On land, there is evidence for a temporal disturbance of plant communities but only few plant taxa finally disappeared. Terrestrial vertebrates also suffered but timing and extent of this extinction remain equivocal. The cause of the end‐Triassic mass extinction was probably linked to the contemporary activity of the Central Atlantic Magmatic Province, which heralded the breakup of the supercontinent Pangaea. Possible kill mechanisms associated with magmatic activity include sea‐level changes, marina anoxia, climatic changes, release of toxic elements and compounds and ocean acidification. Recovery from the extinction event was remarkably fast for marine level‐bottom faunas but delayed for reef communities, possibly because reef organisms were more co‐evolved and suffered higher losses during the extinction.

Key Concepts

Nearly half of all marine genera and a smaller but still significant proportion of terrestrial taxa went extinct at the end of the Triassic period,c. 200 million years ago.

The end‐Triassic mass extinction took place during a geologically short time interval, which coincided with the onset of massive magmatic extrusions along fracture zones of the disassembling supercontinent Pangaea.

A cause‐and‐effect relationship between magmatic activity and mass extinction is indicated by the accordance of predicted extinction patterns and observed data from the fossil record.

Ocean acidification as a kill mechanism in marine ecosystems is confirmed by preferential extinction of taxa with thick aragonitic skeletons.

The end‐Triassic mass extinction event provides a test case for studying evolutionary responses to major environmental disturbances on the global scale and over geological time.

Although there are differences in emission rates, the massive magmatic CO2release at the end of the Triassic is quantitatively similar to a potential release by complete combustion of the global fossil fuel reserves.

A prediction from data of the fossil record for marine ecosystems is that level‐bottom communities are able to recover much more quickly from the effects of excess CO2than reefs.
Roseiflexaceae
Authors: Thiel Vera , Hanada Satoshi
Published: July 2021

Ro.se.i.fle.xa.ce'ae. N.L. masc. n.
Roseiflexus
type genus of the family;
‐aceae
ending to denote family; N.L. fem. pl. n.
Roseiflexaceae
the
Roseiflexus
family.

Chloroflexi / Chloroflexia / Chloroflexales / Roseiflexaceae

The family
Roseiflexaceae
currently consists of two genera with validly described names,
Roseiflexus
and
Heliothrix
. However, based on 16S rRNA gene sequence analyses,
Heliothrix
cannot be confirmed as a member of this family, while the inclusion of the provisionally described genus
Candidatus
Kouleothrix as well as six further putative genera, for which no isolated representative has been described, is indicated. All isolated organisms belonging to the family have unbranched multicellular filamentous morphology showing gliding motility.
Roseiflexus
and
Heliothrix
members are thermophilic phototrophs able to grow between 40 and 55°C and prefer neutral to slightly alkaline conditions. Cultures are reddish brown to reddish‐orange in color. They contain bacteriochlorophyll (BChl)
a
and derivatives of γ‐carotene but lack BChl
c
and chlorosomes that are typical of
Chloroflexus
spp. belonging to the family
Chloroflexaceae
. The cellular fatty acids in
Roseiflexus
species are C
16:0
, C
14:0
, and C
15:0
. The major quinone is MK‐11. Habitats are microbial mats in hot springs.
Ca
. Kouleothrix represents the “Eikenboom morphotype 1851” isolated from activated sludge samples. Members of this group are mesophilic, neutrophilic filamentous organisms with facultative metabolism of respiratory and fermentative growth. Genome analyses indicate the genetic potential for phototrophy; however, neither phototrophic growth nor BChl production has been observed in culture. Habitats are activated sludge systems.

DNA G + C content (mol%)
: 62.0 (HPLC), 60.2–62.5 (
Roseiflexus
spp. and
Ca
. Kouleothrix aurantiaca genome analyses).

Type genus
: Roseiflexus Hanada et al. 2002
VP
.
Kocuria
Authors: Sahin Nevzat , Ay Hilal , Saygin Hayrettin
Published: July 2021

Ko.cu'ri.a. N.L. fem. n.Kocuria, named after Miroslav Kocur, a Slovakian microbiologist for his pioneering studies on Gram‐stain‐positive cocci.

Actinobacteria / Actinomycetia / Micrococcales / Micrococcaceae / Kocuria

The genusKocuriaaccommodates chemoorganotroph, aerobic, and Gram‐stain‐positive bacteria that can be isolated from various habitats. Cells of these actinobacteria are coccoid or spherical, which develop yellow‐orange or pink‐red colonies.Kocuriaspecies are able to use various carbon sources and produce acids from one or more carbohydrates, which differentiate them from the genusMicrococcus. Most strains of the genus are capable of growing at 20–37°C, while some strains can also grow at 5°C. Salt tolerance among the species is variable, and some strains can tolerate NaCl up to 15%. Members of the genusKocuriahave relatively small genomes ranging between 2.7 and 4.1 Mb. All sequenced genomes ofKocuriahave operons responsible for resistance to antibiotics and toxic compounds. In addition, all genomes contain operons for invasion and intracellular resistance exemplified by the presence ofMycobacteriumvirulence operons involved in protein synthesis and DNA transcription, which provide evidence for their emergence as opportunistic pathogens in humans. The genomes ofKocuriaencode genes for enzymes necessary for biosynthesis of aliphatic hydrocarbons.Kocuriaspecies are characterized as psychrotolerant mesophiles and moderate halotolerants with relatively high salt tolerance. The major fatty acid is anteiso‐C15:0. Known habitats are soil, seawater, sediment, air, animal tissues, plant rhizosphere, and fermented food.

DNA G + C content (mol%): 60–74 (from genome sequence).

Type species:Kocuria roseaStackebrandt et al. 1995 (basonym:Micrococcus roseusFlügge 1886AL).
Being “present” in the online learning space
Authors: Rhodes Christy M. , Schmidt Steven W.
Published: July 2021

Social presence is the feeling of connectedness among learners. In this article, the authors explore the theory and practice related to social practice in online adult learning environments.
Becoming effective online facilitators
Authors: Baldwin Cheryl K. , Conceição Simone C. O.
Published: July 2021

This article reviews the strategies discussed in this special issue using the framing of knowledge synergies for effective online facilitation. Guidance and resources for continuous professional improvement through self and peer assessment, creating spaces for professional learning, and managing workload are explored.
Pediatric inherited peripheral neuropathy: a prospective study at a Spanish referral center
Authors: Argente‐Escrig Herminia , Frasquet Marina , Vázquez‐Costa Juan Francisco , Millet‐Sancho Elvira , Pitarch Inmaculada , Tomás‐Vila Miguel , Espinós Carmen , Lupo Vincenzo , Sevilla Teresa
Published: July 2021

Background

Single‐center clinical series provide important information on genetic distribution that can guide genetic testing. However, there are few such studies on pediatric populations with inherited peripheral neuropathies (IPNs).

Methods

Thorough genetic testing was performed on IPN patients under 20 years of age from a geographically well‐defined Mediterranean area (Valencian Community, Spain), annually assessed with the Charcot–Marie–Tooth disease Pediatric Scale (CMTPedS).

Results

From 86 families with IPNs, 99 patients (59 males) were identified, 85 with sensorimotor neuropathy or CMT (2/3 demyelinating form) and 14 with distal hereditary motor neuropathy (dHMN). Genetic diagnosis was achieved in 79.5% families, with a similar mutation detection rate in the demyelinating (88.7%) and axonal (89.5%) forms, significantly higher than in the dHMN families (27.3%). CMT1A was the most common subtype, followed by those carrying heterozygous mutations in either the GDAP1 or GJB1 genes. Mutations in 15 other genes were identified, including a new pathogenic variant in the ATP1A gene. The CMTPedS detected significant disease progression in all genetic subtypes of CMT, at a rate of 1.84 (±3.7) over 1 year (p < 0.0005, n = 62) and a 2‐year rate of 3.6 (±4.4: p < 0.0005, n = 45). Significant disease worsening was also detected for CMT1A over 1 (1.7 ± 3.6, p < 0.05) and 2 years (4.2 ± 4.3, p < 0.0005).

Conclusions

This study highlights the unique spectrum of IPN gene frequencies among pediatric patients in this specific geographic region, identifying the CMTPedS as a sensitive tool to detect significant disease worsening over 1 year that could help optimize the design of clinical trials.
Bimodal Microwave Method for Thickness Estimation of Surface Coatings on Polymer Composites
Authors: Li Zhen , Meng Zhaozong , Soutis Constantinos , Haigh Arthur , Wang Ping , Gibson Andrew
Published: July 2021

Two new microwave sensors, an open cylindrical cavity resonator with a T‐shaped excitation element and a flanged coaxial line sensor, are used for the nondestructive thickness measurement of surface coatings on a unidirectional carbon fiber‐reinforced polymer (CFRP) laminate. Both sensors are found insensitive to the anisotropy of the composite substrate, offering easy implementation. Three commercially available plastic films, polyethylene (PE), polyethylene terephthalate (PET), and polyvinyl chloride (PVC), are used to simulate the coating. In the setup, the microwave sensors are directly mounted on the 4 mm‐thick composite plate. The coating affects the surface impedance of the composite, causing changes to the signal reflection. Calibration is performed by the measurement of samples with known coating thicknesses. For the cavity resonator, a linear relationship is obtained between the resonance frequency shift and the thickness; the difference between the measured and actual thickness values is around 17 μm. For the coaxial line sensor, the phase variation increases with increasing thickness. For both sensors used, the estimation error for a coating thickness in the region of 200 μm can be well within 10%.
3D Free Vibration Analysis of Functionally Graded Plates with Arbitrary Boundary Conditions in Thermal Environment
Authors: Kang Rui , Xin Fengxian , Shen Cheng , Lu Tian Jian
Published: July 2021

An analytical method for free vibration of functionally graded (FG) plates with arbitrary boundary conditions in thermal environments is developed based on 3D elasticity theory. Material properties of the FG plate are assumed to be temperature dependent but graded along with its thickness. At the edges of the plate, three different sets of linear springs are introduced, so that its boundary condition can be altered by changing the spring stiffness. Each displacement component of the plate is expanded as a standard Fourier cosine series, supplemented with closed‐form auxiliary functions. With thermal environment effects duly accounted for, the energy method is used to derive eigenvalue equations, whereas the Rayleigh−Ritz procedure is utilized to calculate the natural frequencies of the FG plate. Numerical examples show that the present method converges quickly and gives satisfactory results. The method is then utilized to calculate the natural frequencies of FG plates having different aspect ratios, volume fractions, and elastic boundaries.
Biomimetic Strain‐Stiffening Hydrogel with Crimped Structure
Authors: Luo Jiye , Li Shengjie , Xu Jingyu , Chai Muyuan , Gao Liang , Yang Chunzhen , Shi Xuetao
Published: July 2021

Synthetic hydrogels are unique tissue mimics but rarely reproduce the strain‐stiffening properties of native tissues. This mechanical mismatch impairs the performance of hydrogels in practical applications. Inspired by the crimped structure of collagenous tissues, a series of strain‐stiffening hydrogels composed of curved parallel fibers are developed. These fibers are constructed from a bundle of intertwisted nanofibrils composed of short alkyl side chain‐modified polymer chains. This hierarchical organization enables exquisitely cascaded deformation that facilitates soft‐to‐firm and resilience‐to‐viscoelasticity transitions, thus synergically mimicking the strain‐adaptive stiffening and damping behaviors of natural tissues. Together with structural evolution and a constitutive model, rationally tuning the tortuosity and flexibility of the curved fibers produces a diverse combination of strain‐stiffening properties and unprecedented penetration into the regions of several tissues. The crimped structure and the resultant stiffening properties constitute major improvements to nanofiber‐based scaffolds for use in collagenous tissue repair.
Single‐Molecule Binding Assay Using Nanopores and Dimeric NP Conjugates
Authors: Ren Ren , Sun Maozhong , Goel Pratibha , Cai Shenglin , Kotov Nicholas A. , Kuang Hua , Xu Chuanlai , Ivanov Aleksandar P. , Edel Joshua B.
Published: July 2021

The ability to measure biomarkers, both specifically and selectively at the single‐molecule level in biological fluids, has the potential to transform the diagnosis, monitoring, and therapeutic intervention of diseases. The use of nanopores has been gaining prominence in this area, not only for sequencing but more recently in screening applications. The selectivity of nanopore sensing can be substantially improved with the use of labels, but substantial challenges remain, especially when trying to differentiate between bound from unbound targets. Here highly sensitive and selective molecular probes made from nanoparticles (NPs) that self‐assemble and dimerize upon binding to a biological target are designed. It is shown that both single and paired NPs can be successfully resolved and detected at the single‐molecule nanopore sensing and can be used for applications such as antigen/antibody detection and microRNA (miRNA) sequence analysis. It is expected that such technology will contribute significantly to developing highly sensitive and selective strategies for the diagnosis and screening of diseases without the need for sample processing or amplification while requiring minimal sample volume.
Thin‐Film Thermoelectric Generators Comprising Molybdenum‐Based MXenes pn Modules
Authors: Park Taeho , Cho Kyoungah , Kim Sangsig
Published: July 2021

In this study, the thermoelectric characteristics of spin‐coated p‐Mo2C and n‐Mo2Ti2C3thin films and the scalability of MXene thin‐film thermoelectric generators (TFTEGs) constructed with pn modules are investigated. The in‐plane thermal conductivities are measured at room temperature to be 0.37 and 0.45 W (m K)−1for the p‐Mo2C and n‐Mo2Ti2C3thin films, respectively. The dimensionless figures of merit ZT are determined to be 1.7 × 10−5and 2.6 × 10−4for the p‐Mo2C and n‐Mo2Ti2C3thin films, respectively. The scalability of the MXene TFTEG is evaluated by the Seebeck voltage being directly proportional to the number of pn modules. The MXene TFTEG constructed with 200‐pn modules generates a Seebeck voltage of 399.9 mV and an output power of 6 mW cm−2at a ΔTof 5.4 K.
Fluidized bed hydrodynamic modeling of CO2 in syngas: Distorted RTD curves due to adsorption on FCC
Authors: Bérard Ariane , Blais Bruno , Patience Gregory S.
Published: July 2021

Bubbles rising through fluidized beds at velocities several times superficial velocities contribute to solids backmixing. In micro‐fluidized beds, the walls constrain bubble sizes and velocities. To evaluate gas‐phase hydrodynamics and identify diffusional contributions to longitudinal dispersion, we injected a mixture of H2, CH4, CO, and CO2 (syngas) as a bolus into a fluidized bed of porous fluid catalytic cracking catalyst while a mass‐spectrometer monitored the effluent gas concentrations at 2 Hz. The CH4, CO, and CO2 trailing RTD traces were elongated versus H2 demonstrating a chromatographic effect. An axial dispersion model accounted for 92% of the variance but including diffusional resistance between the bulk gas and catalyst pores and adsorption explained 98.6% of the variability. At 300°C, the CO2 tailing disappeared consistent with expectations in chromatography (no adsorption). H2 and He are poor gas‐phase tracers at ambient temperature. We recommend measuring RTD at operating conditions.