bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in composition of cuticular biochemicals of the facultatively polygynous ant Petalomyrmex phylax during range expansion in Cameroon with respect to social, spatial and genetic variation
Authors: DALECKY AMBROISE , RENUCCI MARIELLE , TIRARD ALAIN , DEBOUT GABRIEL , ROUX MAURICE , KJELLBERG FINN , PROVOST ERICK 
Published: July 2007

AbstractIn social insects, biochemicals found at the surface of the cuticle are involved in the recognition process and in protection against desiccation and pathogens. However, the relative contribution of evolutionary forces in shaping diversity of these biochemicals remains largely unresolved in ants. We determined the composition of epicuticular biochemicals for workers sampled in 12 populations of the ant Petalomyrmex phylax from Cameroon. Genetic variation at 12 microsatellite markers was used to infer population history and to provide null expectations under the neutrality hypothesis. Genetic data suggest a recent southward range expansion of this ant species. Furthermore, there is a decline southward in the numbers of queens present in mature colonies. Here, we contrast the pattern of biochemical variation against genetic, social and spatial parameters. We thus provide the first estimates of the relative contribution of neutral and selective processes on variation of ant cuticular profile. Populations in migration–drift disequilibrium showed reduction of within‐population variation for genetic markers as well as for cuticular profiles. In these populations, the cuticular profile became biased towards a limited number of high molecular weight molecules. Within‐ and among‐population biochemical variation was explained by both genetic and social variation and by the spatial distribution of populations. We therefore propose that during range expansion of P. phylax, the composition of epicuticular compounds has been affected by a combination of neutral processes — genetic drift and spatially limited dispersal — and spatially varying selection, social organization and environmental effects.
Clinicopathology of childhood‐onset renal systemic lupus erythematosus
Authors: OLOWU WASIU A , ADELUSOLA KAYODE A , SENBANJO IDOWU O 
Published: July 2007

SUMMARY:Aims:  To determine the clinicolaboratory renal manifestations; glomerular, extra‐glomerular histopathologic lesions; renal tubular dysfunction (RTD) frequency and outcome of a short‐term renal follow up in Nigerian children with systemic lupus erythematosus (SLE).Methods:  A non‐randomized prospective study of consecutive cases of childhood‐onset SLE with nephropathy was conducted. Baseline/follow‐up clinicolaboratory data were collected. Each patient was followed up for 12 months.Results:  Seven of the 11 children studied were girls. The median age at diagnosis was 11.0 years. Median diagnosis time interval (1.9 years) and median time of renal disease onset (1.0 year) were similar. Hypertension, nephrotic syndrome and acute renal failure (ARF) occurred in 45.5%, 54.5% and 63.7% of the patients, respectively. The glomerular lesions were non‐proliferative lupus nephritis (LN) in 9.0% (class II LN); focal (class III LN) and diffuse (class IV LN) proliferative LN (PLN) in 27.0% and 64.0%, respectively. Tubulointerstitial nephritis (TIN, 91.0%) and RTD (64.0%) were common. ARF (P = 0.033) and RTD (P = 0.015) were significantly associated with severe TIN. Complete renal remission rate at end‐point was 71.4%. Relapse and renal survival rates were 14.3% and 86.0%, respectively. RTD was persistent in 43.0%.Conclusion:  Renal function disorders, diffuse PLN and extra‐glomerular lesions were frequent. Significant association of ARF and RTD with severe TIN in this series suggests the need for early renal tubular function (RTF) assessment in our SLE patients. Deranged RTF may be marker of severe TIN in SLE warranting early confirmatory renal biopsy and aggressive interventional treatment.
A SWINE MODEL FOR LONG‐TERM EVALUATION OF PROSTHETIC HEART VALVES
Authors: Li Demin , Ren Bin‐Hui , Shen Yi , Wu Haiwei , Wang Changtian , Zhang Lidong , Zhu Jiaquan , Jing Hua 
Published: July 2007

Background:  The objective of this study was to develop a porcine model of mitral valve replacement (MVR) for long‐term evaluation of prosthetic heart valves.Methods:  Sixteen 25‐kg male Bama miniature pigs underwent MVR using St Jude Medical valve (21 mm). Each animal was allocated to an anticoagulation protocol after surgery (group I, s.c. heparin injection and warfarin (n = 8); group II, s.c. low‐molecular‐weight heparin and warfarin (n = 8)) and was followed for up to 20 weeks. Terminal studies were carried out on all animals having survived for more than 140 days or died.Results:  Fourteen animals survived for more than 1 month without signs of heart failure. One of group I animals died from haemorrhagic (haemopericardium) complications on the 9th postoperative day, and another animal of group I died on the 18th postoperative day because of valve thrombosis.Conclusions:  Compared with other species, humans and pigs show remarkable anatomical and physiological similarities. This model is promising for long‐term preclinical evaluation of prosthetic heart valves and evaluation of postoperative anticoagulant agents.
Microbial response to salinity change in Lake Chaka, a hypersaline lake on Tibetan plateau
Authors: Jiang Hongchen , Dong Hailiang , Yu Bingsong , Liu Xinqi , Li Yiliang , Ji Shanshan , Zhang Chuanlun L. 
Published: July 2007

SummaryPrevious investigations of the salinity effects on the microbial community composition have largely been limited to dynamic estuaries and coastal solar salterns. In this study, the effects of salinity and mineralogy on microbial community composition was studied by using a 900‐cm sediment core collected from a stable, inland hypersaline lake, Lake Chaka, on the Tibetan Plateau, north‐western China. This core, spanning a time of 17 000 years, was unique in that it possessed an entire range of salinity from freshwater clays and silty sands at the bottom to gypsum and glauberite in the middle, to halite at the top. Bacterial and archaeal communities were studied along the length of this core using an integrated approach combining mineralogy and geochemistry, molecular microbiology (16S rRNA gene analysis and quantitative polymerase chain reaction), cultivation and lipid biomarker analyses. Systematic changes in microbial community composition were correlated with the salinity gradient, but not with mineralogy. Bacterial community was dominated by the Firmicutes‐related environmental sequences and known species (including sulfate‐reducing bacteria) in the freshwater sediments at the bottom, but by halophilic and halotolerant Betaproteobacteria and Bacteroidetes in the hypersaline sediments at the top. Succession of proteobacterial groups along the salinity gradient, typically observed in free‐living bacterial communities, was not observed in the sediment‐associated community. Among Archaea, the Crenarchaeota were predominant in the bottom freshwater sediments, but the halophilic Halobacteriales of the Euryarchaeota was the most important group in the hypersaline sediments. Multiple isolates were obtained along the whole length of the core, and their salinity tolerance was consistent with the geochemical conditions. Iron‐reducing bacteria were isolated in the freshwater sediments, which were capable of reducing structural Fe(III) in the Fe(III)‐rich clay minerals predominant in the source sediment. These data have important implications for understanding how microorganisms respond to increased salinity in stable, inland water bodies.
Grazing protozoa and magnetosome dissolution in magnetotactic bacteria
Authors: Martins Juliana L. , Silveira Thaís S. , Abreu Fernanda , Silva Karen T. , Da Silva‐Neto Inácio D. , Lins Ulysses 
Published: July 2007

SummaryMagnetotactic bacteria show an ability to navigate along magnetic field lines because of magnetic particles called magnetosomes. All magnetotactic bacteria are unicellular except for the multicellular prokaryote (recently named ‘Candidatus Magnetoglobus multicellularis’), which is formed by an orderly assemblage of 17–40 prokaryotic cells that swim as a unit. A ciliate was used in grazing experiments with the M. multicellularis to study the fate of the magnetosomes after ingestion by the protozoa. Ciliates ingested M. multicellularis, which were located in acid vacuoles as demonstrated by confocal laser scanning microscopy. Transmission electron microscopy and X‐ray microanalysis of thin‐sectioned ciliates showed the presence of M. multicellularis and magnetosomes inside vacuoles in different degrees of degradation. The magnetosomes are dissolved within the acidic vacuoles of the ciliate. Depending on the rate of M. multicellularis consumption by the ciliates the iron from the magnetosomes may be recycled to the environment in a more soluble form.
Heterotrophic symbionts of phototrophic consortia: members of a novel diverse cluster of Betaproteobacteria characterized by a tandem rrn operon structure
Authors: Pfannes Kristina R. , Vogl Kajetan , Overmann Jörg 
Published: July 2007

SummaryPhototrophic consortia represent the most highly developed type of interspecific association of bacteria and consist of green sulfur bacterial epibionts attached around a central colourless rod‐shaped bacterium. Based on 16S rRNA gene sequencing, the central bacterium of the consortium ‘Chlorochromatium aggregatum’ was recently shown to represent a novel and phylogenetically isolated lineage of the Comamonadaceae within the β‐subgroup of the Proteobacteria. To date, 19 types of phototrophic consortia are distinguished based on the different 16S rRNA gene sequences of their epibionts, but the diversity and phylogenetic relationships of the heterotrophic partner bacteria are still unknown. We developed an approach based on the specific rrn (ribosomal RNA) operon structure of the central bacterium of ‘C. aggregatum’ to recover 16S rRNA gene sequences of other central bacteria and their close relatives from natural consortia populations. Genomic DNA of the central bacterium of ‘C. aggregatum’ was first enriched several hundred‐fold by employing a selective method for growth of consortia in a monolayer biofilm followed by a purification of the genome of the central bacterium by cesium chloride‐bisbenzimidazole equilibrium density gradient centrifugation. A combination of inverse PCR, cloning and sequencing revealed that two rrn operons of the central bacterium are arranged in a tandem fashion and are separated by an unusually short intergenic region of 195 base pairs. This rare gene order was exploited to screen various natural microbial communities by PCR. We discovered a diverse and previously unknown subgroup of Betaproteobacteria in the chemoclines of freshwater lakes. This group was absent in other freshwater and soil samples. All the 16S rRNA gene sequences recovered are related to that of the central bacterium of ‘C. aggregatum’. Fluorescence in situ hybridization indicated that two of these sequences originated from central bacteria of different phototrophic consortia, which, however, were only distantly related to the central bacterium of ‘C. aggregatum’. Based on a detailed phylogenetic analysis, these central bacterial symbionts of phototrophic consortia have a polyphyletic origin.
Biofilm formation in Desulfovibrio vulgaris Hildenborough is dependent upon protein filaments
Authors: Clark Melinda E. , Edelmann Richard E. , Duley Matt L. , Wall Judy D. , Fields Matthew W. 
Published: July 2007

Summary Desulfovibrio vulgaris Hildenborough is a Gram‐negative sulfate‐reducing bacterium (SRB), and the physiology of SRBs can impact many anaerobic environments including radionuclide waste sites, oil reservoirs and metal pipelines. In an attempt to understand D. vulgaris as a population that can adhere to surfaces, D. vulgaris cultures were grown in a defined medium and analysed for carbohydrate production, motility and biofilm formation. Desulfovibrio vulgaris wild‐type cells had increasing amounts of carbohydrate into stationary phase and approximately half of the carbohydrate remained internal. In comparison, a mutant that lacked the 200 kb megaplasmid, strain ΔMP, produced less carbohydrate and the majority of carbohydrate remained internal of the cell proper. To assess the possibility of carbohydrate re‐allocation, biofilm formation was investigated. Wild‐type cells produced approximately threefold more biofilm on glass slides compared with ΔMP; however, wild‐type biofilm did not contain significant levels of exopolysaccharide. In addition, stains specific for extracellular carbohydrate did not reveal polysaccharide material within the biofilm. Desulfovibrio vulgaris wild‐type biofilms contained long filaments as observed with scanning electron microscopy (SEM), and the biofilm‐deficient ΔMP strain was also deficient in motility. Biofilms grown directly on silica oxide transmission electron microscopy (TEM) grids did not contain significant levels of an exopolysaccharide matrix when viewed with TEM and SEM, and samples stained with ammonium molybdate also showed long filaments that resembled flagella. Biofilms subjected to protease treatments were degraded, and different proteases that were added at the time of inoculation inhibited biofilm formation. The data indicated that D. vulgaris did not produce an extensive exopolysaccharide matrix, used protein filaments to form biofilm between cells and silica oxide surfaces, and the filaments appeared to be flagella. It is likely that D. vulgaris used flagella for more than a means of locomotion to a surface, but also used flagella, or modified flagella, to establish and/or maintain biofilm structure.
Quantitative analysis of glutamatergic and GABAergic neurons expressing 5‐HT2A receptors in human and monkey prefrontal cortex
Authors: De Almeida J. , Mengod G. 
Published: July 2007

Abstract5‐hydroxytryptamine (5‐HT) or serotonin 2A receptors play an important role in modulation of prefrontal cortex (PFC) activity and have been implicated in the physiopathology of psychiatric disorders. There is no quantitative information on the percentage of glutamatergic and GABAergic cells that express 5‐HT2A receptors in human and monkey PFC. We have used double in situ hybridization to quantify the mRNA co‐localization of 5‐HT2A receptor with the glutamatergic transporter vesicular glutamate transporter 1, and with the GABAergic marker glutamic acid decarboxylase 65/67 and in parvalbumin and calbindin GABAergic cell populations. Our results show that nearly every glutamatergic cell (86–100%) in layers II‐V expressed 5‐HT2A receptor mRNA in both species. This percentage was lower in layer VI (13–31%). In contrast, not all the GABAergic interneurons (13–46%) expressed 5‐HT2A receptor mRNA. This receptor was expressed in 45–69% of parvalbumin and in 61–87% of calbindin positive cells. These results indicate that, while the majority of glutamatergic neurons can be sensitive to 5‐HT action via 5‐HT2A receptors, this modulation occurs only in a limited population of GABAergic interneurons and provides new neuroanatomical information about the role played by serotonin through 5‐HT2A receptors in the PFC and on the sites of action for drugs such as antipsychotics and antidepressants used in treatment of psychiatric disorders.
Minocycline and riluzole brain disposition: interactions with p‐glycoprotein at the blood–brain barrier
Authors: Milane Aline , Fernandez Christine , Vautier Sarah , Bensimon Gilbert , Meininger Vincent , Farinotti Robert 
Published: July 2007

AbstractAmyotrophic lateral sclerosis is a neurodegenerative fatal disease. The only drug recognized to increase the survival time is riluzole(RLZ). In animal models, minocycline (MNC) delayed the onset of the disease and increased the survival time (in combination with RLZ). The objective of our work was to study the interactions between RLZ, MNC and the efflux pump p‐glycoprotein (p‐gp) at the blood–brain barrier. We investigated these two drugs as: (i) p‐gp substrates by comparing their brain uptake in CF1mdr1a(−/−) andmdr1a(+/+) mice, (ii) p‐gp modulators by studying their effect on the cerebral uptake of digoxin.mdr1a(−/−) mice showed higher brain uptake of MNC and RLZ thanmdr1a(+/+) (in a 1.6‐ and 1.4‐fold, respectively); and inmdr1a(+/+) mice pre‐treated with repeated doses of MNC, brain uptake of digoxin was increased. When both drugs were administrated tomdr1a(+/+) mice, MNC increased the brain uptake of RLZ in a 2.1‐fold. In conclusion, MNC and RLZ are both p‐gp substrates. MNC is also a p‐gp inhibitor and increases the brain diffusion of RLZ.In vitroexperiments with the GPNT cell line confirmed these results. These interactions should be taken into account in the design of future clinical trials.
Aminoindan and hydroxyaminoindan, metabolites of rasagiline and ladostigil, respectively, exert neuroprotective properties in vitro
Authors: Bar‐Am Orit , Amit Tamar , Youdim Moussa B. H. 
Published: July 2007

AbstractThe anti‐Parkinson, selective irreversible monoamine oxidase B inhibitor drug, rasagiline (Azilect), recently approved by the US Food and Drug Administration, has been shown to possess neuroprotective‐neurorescue activities in in vitro and in vivo models. Recent preliminary studies indicated the potential neuroprotective effect of the major metabolite of rasagiline, 1‐(R)‐aminoindan. In the current study, the neuroprotective properties of 1‐(R)‐aminoindan were assessed employing a cytotoxic model of human neuroblastoma SK‐N‐SH cells in high‐density culture‐induced neuronal death. We show that aminoindan (0.1–1 μmol/L) significantly reduced the apoptosis‐associated phosphorylated protein, H2A.X (Ser139), decreased the cleavage of caspase 9 and caspase 3, while increasing the anti‐apoptotic proteins, Bcl‐2 and Bcl‐xl. Protein kinase C (PKC) inhibitor, GF109203X, prevented the neuroprotection, indicating the involvement of PKC in aminoindan‐induced cell survival. Aminoindan markedly elevated pPKC(pan) and specifically that of the pro‐survival PKC isoform, PKCε. Additionally, hydroxyaminoindan, a metabolite of a novel bifunctional drug, ladostigil [(N‐propargyl‐(3R) aminoindan‐5yl)‐ethyl methyl carbamate], combining cholinesterase and monoamine oxidase inhibitor activity, exerted similar neuroprotective properties. Aminoindan and hydroxyaminoindan also protected rat pheochromacytoma PC‐12 cells against the neurotoxin, 6‐hydroxydopamine. Our findings suggest that both metabolites may contribute to the overall neuroprotective activity of their respective parent compounds, further implicating rasagiline and ladostigil as potentially valuable drugs for treatment of a wide variety of neurodegenerative disorders of aging.
PHOSPHORUS METABOLISM AND MANAGEMENT IN CHRONIC KIDNEY DISEASE: Lanthanum Carbonate as a First‐Line Phosphate Binder: The “Cons”
Authors: Drüeke Tilman B. 
Published: July 2007

AbstractControlling serum phosphorus levels in patients with renal failure is critical. The use of oral phosphate‐binding agents is universal for patients with end‐stage kidney disease to reduce phosphate absorption. The therapeutic goal is to reduce serum phosphorus levels without disturbing calcium homeostasis or promoting accumulation of potentially toxic elements from the medication. Aluminum hydroxide effectively reduces serum phosphorus, but has largely been abandoned as a first‐line phosphate binder because of hazards associated with metal absorption and tissue accumulation. Traditional calcium‐based phosphate binders tend to promote hypercalcemia and calcium overloading, and are linked to accelerated cardiovascular calcification. Interest in aluminum‐free, calcium‐free phosphate‐binding agents continues to grow. Sevelamer hydrochloride, a metal‐free, calcium‐free hydrogel, is not absorbed, has been proven safe and efficacious in controlling serum phosphorus, and is associated with attenuated progression of cardiovascular calcification. Lanthanum carbonate is a newer aluminum‐free, calcium‐free phosphate‐binding agent. Lanthanum is a rare‐earth trace metal with industrial and agricultural applications. As a therapeutic, this metal‐based binder appears effective in reducing serum phosphorus, yet concerns remain about lanthanum accumulation in tissues during long‐term oral administration. Similar to the metal aluminum, lanthanum is absorbed in the intestine and accumulates in body tissues, especially in the liver, bone, muscle, kidney, and brain. Moreover, the rate of intestinal absorption of lanthanum is enhanced in chronic renal failure. Our experience with aluminum hydroxide suggests caution regarding the long‐term use of another metal‐based agent that displays enhanced absorption in the uremic state and progressive tissue accumulation.
PHOSPHORUS METABOLISM AND MANAGEMENT IN CHRONIC KIDNEY DISEASE: The Role of Magnesium Binders in Chronic Kidney Disease
Authors: Spiegel David M. 
Published: July 2007

AbstractMagnesium is predominately an intracellular cation that plays a critical role in cellular physiology. Serum levels are often slightly elevated in patients on chronic hemodialysis and older reports suggests that total body stores may also be increased, based on bone biopsies in patients treated with higher dialysate magnesium levels than are currently in use today. Several studies have shown that magnesium, particularly in the form of magnesium carbonate, is an effective phosphate binder and can decrease patients’ exposure to calcium. Retrospective studies suggest that magnesium may prevent vascular calcification in dialysis patients, although this remains controversial and has not been evaluated prospectively. Magnesium may reduce arrhythmias postoperatively and, while it may theoretically reduce arrhythmic death in dialysis patients, this hypothesis has never been tested. While short‐term or adjuvant use of magnesium carbonate appears safe and effective as a phosphate binder, more studies are needed to evaluate the long‐term effects on vascular calcification, bone histology, and mortality.
PHOSPHORUS METABOLISM AND MANAGEMENT IN CHRONIC KIDNEY DISEASE: Phosphorus Homeostasis in Normal Health and in Chronic Kidney Disease Patients with Special Emphasis on Dietary Phosphorus Intake
Authors: Uribarri Jaime 
Published: July 2007

AbstractElevated serum phosphorus has been identified as a cardiovascular risk factor in chronic kidney disease (CKD) patients and a clear understanding of phosphorus homeostasis is very important for practicing nephrologists. At any particular point, serum phosphorus levels reflect the balance between movements of this mineral from and into the intestine, bone, intracellular space, and kidneys. We briefly review here all these exchanges with a particular emphasis on dietary phosphorus intake. Despite all the oral phosphorus binders currently available in the market, dietary restriction of this mineral remains a cornerstone for the prevention and treatment of hyperphosphatemia. An effective restriction of dietary intake of phosphorus requires prescription of a moderate protein intake (0.9–1.0 g/kg/day) and restricted consumption of highly processed fast and convenience foods. Phosphorus added during food processing is an important source of this mineral because of its magnitude and high bioavailabilty. Moreover, as food manufacturers are not required to label the amount of phosphorus added during food processing, a significant amount of the current daily phosphorus intake remains unaccounted when estimating phosphorus intake in CKD patients. The recent development of low phosphorus‐containing food products represents a very useful addition for CKD patients.