bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Study of the Metabolism of Apolipoprotein B100 in Relation to Insulin Resistance in African American Males
Authors: Sumner Anne E. , Falkner Bonita , Diffenderfer Margaret R. , Barrett P. Hugh R. , Marsh Julian B. 
Published: November 2003

The purpose of this study was to determine the relationship between insulin resistance and apoB100 metabolism in African American males. Fifteen subjects, 33 ± 7.6 years old, were divided into two groups, insulin‐resistant (IR) or insulin‐sensitive (IS), based on the sum of the plasma insulin concentrations during an oral glucose tolerance test. The IR group (n = 8) differed significantly from the IS group (n = 7) with respect to body mass index (BMI) (30.1 vs 23.1 kg/m2; P = 0.0003), fasting triglycerides, (118 vs 54 mg/dl, P = 0.013), and total plasma apolipoprotein B100 (80 vs 59 mg/dl, P = 0.014). Significantly elevated apoB100 levels in the IR group were seen in very low density lipoprotein (VLDL) (5.1 vs 3.4 mg/dl, P = 0.045) and intermediate density lipoprotein (IDL) (18 vs 12 mg/dl, P = 0.017) but not in low density lipoprotein (LDL) (57 vs 46 mg/dl, P = 0.19). Total cholesterol, high density lipoprotein cholesterol (HDL‐C), low density lipoprotein cholesterol (LDL‐C), apolipoprotein A‐I, and blood pressure were not significantly different between the two groups. There was a high correlation between the sum of insulins during the oral glucose tolerance test and the BMI (ρ = 0.88, P = 0.0001).In five IR and five IS subjects, apoB100 kinetics were determined in the fasting state using a bolus dose of deuteroleucine and multicompartmental modeling. IR subjects had significantly lower fractional catabolic rates (FCR) in the larger VLDL1 (−70%), the smaller VLDL2 (−71%), and the IDL (−53%) fractions. No significant differences in production rates were observed for any lipoprotein class. There was a significant correlation between the sum of insulins and the FCR of the apoB100 of VLDL1 (ρ = −0.65, P = 0.05) and of IDL (ρ = −0.85, P = 0.004). The correlation coefficient of the sum of insulins and the FCR of VLDL2 was −0.61 with P = 0.067. We conclude that in this population of African American males, IR is correlated with a decreased FCR of apoB100 in VLDL and IDL and elevated plasma levels of apoB and triglycerides (TG). These changes might be explained by decreased clearance of the TG‐rich lipoproteins. We postulate that this may reflect decreased lipoprotein and/or hepatic lipase activity related to insulin resistance and its association with obesity.
Episousse: Incidence of Newly Presenting Seizures in Children in the Region of Sousse, Tunisia
Authors: Dogui Mohamed , Jallon Pierre , Tamallah Jouda Ben , Sakly Ghazy , Trabelsi Mohamed Anouar , Khalifa Khaled , Yacoub Moncef , Abroug Saoussen 
Published: November 2003

Summary:  Purpose: To evaluate the incidence of newly presenting seizures in children in the area of Sousse, Tunisia. Methods: From June 1, 1998, to May 31, 1999, all children aged 1 month to 15 years with first provoked and unprovoked seizures were included. Children with febrile seizures were excluded. All suspected cases were systematically referred to the Department of Functional Explorations of the Nervous System where a detailed questionnaire was filled out by a neurologist. All the patients underwent an EEG. Only 12 patients had a computed tomography (CT) scan. Results: A total of 175 patients were included. Eighteen (10.3%) patients had acute symptomatic seizures, and 157 patients had unprovoked seizures. The incidence rate of first unprovoked seizures was 102.1/100,000. In this latter group, some epileptic syndromes were individualized on strict electroclinical criteria. Conclusions: However, nearly 75% of the cases remained cryptogenic, one of the major reasons that no predominant risk factor was identified in this population.
Effects of Antiepileptic Drugs on Refractory Seizures in the Intact Immature Corticohippocampal Formation In Vitro
Authors: Quilichini Pascale Paule , Diabira Diabé , Chiron Catherine , Milh Mathieu , Ben‐Ari Yehezkel , Gozlan Henri 
Published: November 2003

Summary:  Purpose: We developed a new in vitro preparation of immature rats, in which intact corticohippocampal formations (CHFs) depleted in magnesium ions become progressively epileptic. The better to characterize this model, we examined the effects of 14 antiepileptic drugs (AEDs) currently used in clinical practice. Methods: Recurrent ictal‐like seizures (ILEs, four per hour) were generated in intact CHFs of P7–8 rats, and extracellular recordings were performed in the hippocampus and neocortex. AEDs were applied at clinically relevant concentrations (at least two), during 30 min after the third ILE. Their ability to prevent or to delay the next ILE was examined. Results: Valproic acid and benzodiazepines (clobazam and midazolam) but also phenobarbital and levetiracetam prevent the occurrence of seizures. In contrast, usual concentrations of carbamazepine (CBZ), phenytoin, vigabatrin, tiagabine, gabapentin, lamotrigine (LTG), topiramate, felbamate, and ethosuximide did not suppress ILEs. In addition, LTG and CBZ aggravate seizures in one third of the cases. Conclusions: This intact in vitro preparation in immature animals appears to be quite resistant to most AEDs. Blockade of seizures was achieved with drugs acting mainly at the γ‐aminobutyric acid (GABA)A‐receptor site but not with those that increase the amount of GABA. Drugs with a broad spectrum of activity are efficient but not those preferentially used in partial seizures or absences. We suggest that this preparation may correspond to a model of epilepsy with generalized convulsive seizures and could be helpful to develop new AEDs for refractory infantile epilepsies.
Mental Tasks Induce Gamma EEG with Reduced Responsiveness in Primary Generalized Epilepsies
Authors: Willoughby John O. , Fitzgibbon Sean P. , Pope Kenneth J. , Mackenzie Lorraine , Davey Matthew , Wilcox Robert A , Clark C. Richard 
Published: November 2003

Summary:  Purpose: We previously revealed an interictal increase in intensity of EEG rhythms during quiescent mental activity in the 30‐ to 100‐Hz frequency (gamma) range in primary generalized epilepsy (PGE). We have evidence that there is induction of gamma EEG in normal subjects in response to controlled mental activity. Here we test whether mental tasks further augment interictal gamma oscillations in people with PGE. Methods: We recorded interictal EEG from patients with PGE and partial epilepsy and compared EEG power spectral responses (increases over resting) during mental tasks. Results: In partial epilepsy, mental tasks (except for alternating checkerboard visual stimulation) induced 1.5‐ to 2.5‐fold increases in power of gamma EEG. In generalized epilepsy, generalized increases of 1.5‐fold in gamma EEG were induced by only two mental tasks (reading and subtraction), and enhancement of 1‐ to 1.5‐fold in the remaining six (checkerboard, expectancy, music, learning, recalling, and a video). Conclusions: Gamma EEG is less responsive to mental activation in PGE than in partial epilepsy, confirming an abnormality in gamma mechanisms in PGE. Our findings also provide a possible mechanistic link between mental activity and seizures in reading‐ and arithmetic‐induced seizures.
The Changing Nexus: Tertiary Education Institutions, the Marketplace and the State
Authors: Steier Francis A. 
Published: November 2003

AbstractThis article examines the evolving relationship between the marketplace, the state and tertiary education institutions. The context of these relations has evolved strikingly in recent years, which have seen three major developments: growing system differentiation, changing governance patterns and diminished direct involvement of governments in the funding and provision of tertiary education. This article first describes the key dimensions of the rise of market forces in tertiary education throughout the world and the main implications of this phenomenon. It then articulates the rationale for continuing public intervention in the sector and, in conclusion, outlines the nature of an appropriate enabling framework for the further development of tertiary education.
Cold Shock Response and Major Cold Shock Proteins of
Vibrio cholerae
Authors: Datta Partha Pratim , Bhadra Rupak K. 
Published: November 2003

ABSTRACT

When exponentially growing
Vibrio cholerae
cells were shifted from 37°C to various lower temperatures, it was found that the organism could adapt and grow at temperatures down to 15°C, below which the growth was completely arrested. There was no difference between the patterns of the cold shock responses in toxinogenic and nontoxinogenic strains of
V. cholerae
. Gel electrophoretic analyses of proteins of cold-exposed cells revealed significant induction of two major cold shock proteins (Csps), whose molecular masses were 7.7 kDa (CspA
VC
) and 7.5 kDa (CspV), and six other Csps, most of which were much larger. We cloned, sequenced, and analyzed the
cspV
gene encoding the CspV protein of
V. cholerae
O139 strain SG24. Although CspA
VC
and CspV have similar kinetics of synthesis and down-regulation, the corresponding genes,
cspA
and
cspV
, which are located in the small chromosome, are not located in the same operon. A comparative analysis of the kinetics of synthesis revealed that the CspV protein was synthesized de novo only during cold shock. Although both CspA
VC
and CspV were stable for several hours in the cold, the CspV protein was degraded rapidly when the culture was shifted back to 37°C, suggesting that this protein is probably necessary for adaptation at lower temperatures. Northern blot analysis confirmed that the
cspV
gene is cold shock inducible and is regulated tightly at the level of transcription. Interestingly, the
cspV
gene has a cold shock-inducible promoter which is only 12 nucleotides from the translational start site, and therefore, it appears that no unusually long 5′ untranslated region is present in its mRNA transcript. Thus, this promoter is an exception compared to other promoters of cold shock-inducible genes of different organisms, including
Escherichia coli
. Our results suggest that
V. cholerae
may use an alternative pathway for regulation of gene expression during cold shock.
Involvement of Two Cytosolic Enzymes and a Novel Intermediate, 5′-Oxoaverantin, in the Pathway from 5′-Hydroxyaverantin to Averufin in Aflatoxin Biosynthesis
Authors: Sakuno Emi , Yabe Kimiko , Nakajima Hiromitsu 
Published: November 2003

ABSTRACT

During aflatoxin biosynthesis, 5′-hydroxyaverantin (HAVN) is converted to averufin (AVR). Although we had previously suggested that this occurs in one enzymatic step, we demonstrate here that this conversion is composed of two enzymatic steps by showing that the two enzyme activities in the cytosol fraction of
Aspergillus parasiticus
were clearly separated by Mono Q column chromatography. An enzyme, HAVN dehydrogenase, catalyzes the first reaction from HAVN to a novel intermediate, another new enzyme catalyzes the next reaction from the intermediate to AVR, and the intermediate is a novel substance, 5′-oxoaverantin (OAVN), which was determined by physicochemical methods. We also purified both of the enzymes, HAVN dehydrogenase and OAVN cyclase, from the cytosol fraction of
A. parasiticus
by using ammonium sulfate fractionation and successive chromatographic steps. The HAVN dehydrogenase is a homodimer composed of 28-kDa subunits, and it requires NAD, but not NADP, as a cofactor for its activity. Matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis of tryptic peptides of the purified HAVN dehydrogenase revealed that this enzyme coincides with a protein deduced from the
adhA
gene in the aflatoxin gene cluster of
A. parasiticus
. Also, the OAVN cyclase enzyme is a homodimer composed of 79-kDa subunits which does not require any cofactor for its activity. Further characterizations of both enzymes were performed.
Modification of the Monomer Composition of Polyhydroxyalkanoate Synthesized in
Saccharomyces cerevisiae
Expressing Variants of the β-Oxidation-Associated Multifunctional Enzyme
Authors: Marchesini Silvia , Erard Nadine , Glumoff Tuomo , Hiltunen J. Kalervo , Poirier Yves 
Published: November 2003

ABSTRACT

Expression by
Saccharomyces cerevisiae
of a polyhydroxyalkanoate (PHA) synthase modified at the carboxy end by the addition of a peroxisome targeting signal derived from the last 34 amino acids of the
Brassica napus
isocitrate lyase (ICL) and containing the terminal tripeptide Ser-Arg-Met resulted in the synthesis of PHA. The ability of the terminal peptide Ser-Arg-Met and of the 34-amino-acid peptide from the
B. napus
ICL to target foreign proteins to the peroxisome of
S. cerevisiae
was demonstrated with green fluorescent protein fusions. PHA synthesis was found to be dependent on the presence of both the enzymes generating the β-oxidation intermediate 3-hydroxyacyl-coenzyme A (3-hydroxyacyl-[CoA]) and the peroxin-encoding
PEX5
gene, demonstrating the requirement for a functional peroxisome and a β-oxidation cycle for PHA synthesis. Using a variant of the
S. cerevisiae
β-oxidation multifunctional enzyme with a mutation inactivating the B domain of the R-3-hydroxyacyl-CoA dehydrogenase, it was possible to modify the PHA monomer composition through an increase in the proportion of the short-chain monomers of five and six carbons.
Viability of and Plasmid Retention in Frozen Recombinant
Escherichia coli
over Time: a Ten-Year Prospective Study
Authors: Koenig Gina L. 
Published: November 2003

ABSTRACT

The long-term viability and plasmid retention of recombinant
Escherichia coli
strains were investigated by real-time testing of master cell banks (MCBs) stored at the Roche Molecular Systems Culture Collection (RMSCC). MCBs at the RMSCC were cryogenically frozen and stored at −80°C for long-term preservation. At regular intervals during a period of 5 to more than 10 years, representative cryovials of each MCB were tested for viability and plasmid retention. Plasmid retention and viability for all 30 MCBs were stable over time. Twenty-seven MCBs maintained high levels of plasmid retention (at or near 100%), while three MCBs showed lower plasmid retention rates (ranging from 13.9 to 96.5%) that were consistent over time. New MCBs with high plasmid retention were created from two of the MCBs with lower plasmid retention by selective pressure with high levels of antibiotics. These new MCBs have shown stable viability and high plasmid retention over the first 5 months of storage. In conclusion, this study shows that properly selected, frozen and stored MCBs retain viability and maintain plasmid retention over time. Moreover, it is possible to recover cultures with high plasmid retention from MCBs with low plasmid retention by selecting clones grown in the presence of high levels of antibiotics.
High-Resolution Differentiation of Cyanobacteria by Using rRNA-Internal Transcribed Spacer Denaturing Gradient Gel Electrophoresis
Authors: Janse Ingmar , Meima Marion , Kardinaal W. Edwin A. , Zwart Gabriel 
Published: November 2003

ABSTRACT

For many ecological studies of cyanobacteria, it is essential that closely related species or strains can be discriminated. Since this is often not possible by using morphological features, cyanobacteria are frequently studied by using DNA-based methods. A powerful method for analysis of the diversity and dynamics of microbial populations and for checking the purity and affiliation of cultivated strains is denaturing gradient gel electrophoresis (DGGE). We realized high-resolution discrimination of a variety of cyanobacteria by means of DGGE analysis of sections of the internal transcribed spacer between the 16S and 23S rRNA genes (rRNA-ITS). A forward primer specific for cyanobacteria, targeted at the 3′ end of the 16S rRNA gene, was designed. The combination of this primer and three different reverse primers targeted to the rRNA-ITS or to the 23S rRNA gene yielded PCR products of different sizes from cultures of all 16 cyanobacterial genera that were tested but not from other bacteria. DGGE profiles produced from the shortest section of rRNA-ITS consisted of one band for all but one cyanobacterial genera, and those generated from longer stretches of rRNA-ITS yielded DGGE profiles containing one to four bands. The suitability of DGGE for detecting intrageneric and intraspecific variation was tested by using strains of the genus
Microcystis
. Many strains could be discriminated by means of rRNA-ITS DGGE, and the resolution of this method was strikingly higher than that obtained with previously described methods. The applicability of the developed DGGE assays for analysis of cyanobacteria in field samples was demonstrated by using samples from freshwater lakes. The advantages and disadvantages associated with the use of each developed primer set are discussed.
Binding of Pediocin PA-1 with Anionic Lipid Induces Model Membrane Destabilization
Authors: Gaussier Hélène , Lefèvre Thierry , Subirade Muriel 
Published: November 2003

ABSTRACTTo obtain molecular insights into the action mode of antimicrobial activity of pediocin PA-1, the interactions between this bacteriocin and dimyristoylphosphatidylcholine (DMPC) or dimyristoylphosphatidylglycerol (DMPG) model membranes have been investigated in D2O at pD 6 by Fourier transform infrared spectroscopy. The interactions were monitored with respect to alteration of the secondary structure of pediocin, as registered by the amide I′ band, and phospholipid conformation, as revealed by the methylene νs(CH2) and carbonyl ν(C═;O) stretching vibrations. The results show that no interaction between pediocin and DMPC occurs. By contrast, pediocin undergoes a structural reorganization in the presence of DMPG. Upon heating, pediocin self-aggregates, which is not observed for this pD in aqueous solution. The gel-to-crystalline phase transition of DMPG shifts to higher temperatures with a concomitant dehydration of the interfacial region. Our results indicate that pediocin is an extrinsic peptide and that its action mechanism may lie in a destabilization of the cell membrane.
Microbial Community Dynamics Associated with Rhizosphere Carbon Flow
Authors: Butler Jessica L. , Williams Mark A. , Bottomley Peter J. , Myrold David D. 
Published: November 2003

ABSTRACT

Root-deposited photosynthate (rhizodeposition) is an important source of readily available carbon (C) for microbes in the vicinity of growing roots. Plant nutrient availability is controlled, to a large extent, by the cycling of this and other organic materials through the soil microbial community. Currently, our understanding of microbial community dynamics associated with rhizodeposition is limited. We used a
13
C pulse-chase labeling procedure to examine the incorporation of rhizodeposition into individual phospholipid fatty acids (PLFAs) in the bulk and rhizosphere soils of greenhouse-grown annual ryegrass (
Lolium multiflorum
Lam. var. Gulf). Labeling took place during a growth stage in transition between active root growth and rapid shoot growth on one set of plants (labeling period 1) and 9 days later during the rapid shoot growth stage on another set of plants (labeling period 2). Temporal differences in microbial community composition were more apparent than spatial differences, with a greater relative abundance of PLFAs from gram-positive organisms (i15:0 and a15:0) in the second labeling period. Although more abundant, gram-positive organisms appeared to be less actively utilizing rhizodeposited C in labeling period 2 than in labeling period 1. Gram-negative bacteria associated with the 16:1ω5 PLFA were more active in utilizing
13
C-labeled rhizodeposits in the second labeling period than in the first labeling period. In both labeling periods, however, the fungal PLFA 18:2ω6,9 was the most highly labeled. These results demonstrate the effectiveness of using
13
C labeling and PLFA analysis to examine the microbial dynamics associated with rhizosphere C cycling by focusing on the members actively involved.
Comparative Genomics of Insect-Symbiotic Bacteria: Influence of Host Environment on Microbial Genome Composition
Authors: Rio Rita V. M. , Lefevre Cedric , Heddi Abdelaziz , Aksoy Serap 
Published: November 2003

ABSTRACT

Commensal symbionts, thought to be intermediary amid obligate mutualists and facultative parasites, offer insight into forces driving the evolutionary transition into mutualism. Using macroarrays developed for a close relative,
Escherichia coli
, we utilized a heterologous array hybridization approach to infer the genomic compositions of a clade of bacteria that have recently established symbiotic associations:
Sodalis glossinidius
with the tsetse fly (Diptera,
Glossina
spp.) and
Sitophilus oryzae
primary endosymbiont (SOPE) with the rice weevil (Coleoptera,
Sitophilus oryzae
). Functional biologies within their hosts currently reflect different forms of symbiotic associations. Their hosts, members of distant insect taxa, occupy distinct ecological niches and have evolved to survive on restricted diets of blood for tsetse and cereal for the rice weevil. Comparison of genome contents between the two microbes indicates statistically significant differences in the retention of genes involved in carbon compound catabolism, energy metabolism, fatty acid metabolism, and transport. The greatest reductions have occurred in carbon catabolism, membrane proteins, and cell structure-related genes for
Sodalis
and in genes involved in cellular processes (i.e., adaptations towards cellular conditions) for SOPE. Modifications in metabolic pathways, in the form of functional losses complementing particularities in host physiology and ecology, may have occurred upon initial entry from a free-living to a symbiotic state. It is possible that these adaptations, streamlining genomes, act to make a free-living state no longer feasible for the harnessed microbe.