bluuebunny/crossref_metadata_2025 huggingface dataset:
The thermal regime of rivers: a review
Authors: CAISSIE D.
Published: July 2006

1. The thermal regime of rivers plays an important role in the overall health of aquatic ecosystems, including water quality issues and the distribution of aquatic species within the river environment. Consequently, for conducting environmental impact assessments as well as for effective fisheries management, it is important to understand the thermal behaviour of rivers and related heat exchange processes.

2. This study reviews the different river thermal processes responsible for water temperature variability on both the temporal (e.g. diel, daily, seasonal) and spatial scales, as well as providing information related to different water temperature models currently found in the literature.

3. Water temperature models are generally classified into three groups: regression, stochastic and deterministic models. Deterministic models employ an energy budget approach to predict river water temperature, whereas regression and stochastic models generally rely on air to water temperature relationships.

4. Water temperature variability can occur naturally or as a result of anthropogenic perturbations, such as thermal pollution, deforestation, flow modification and climate change. Literature information is provided on the thermal regime of rivers in relation to anthropogenic impacts and such information will contribute to the better protection of fish habitat and more efficient fisheries management.
Abnormal migration and distribution of neural crest cells in Pax6 heterozygous mutant eye, a model for human eye diseases
Authors: Kanakubo Sachiko , Nomura Tadashi , Yamamura Ken‐ichi , Miyazaki Jun‐ichi , Tamai Makoto , Osumi Noriko
Published: July 2006

PAX6/Pax6 gene encodes a transcription factor that is crucially required for eye development. Pax6 heterozygous mutant mouse (Pax6Sey/+) shows various ocular defects, especially in the anterior segment. It has been well known that the induction of the lens and development of the cornea and retina are dependent on PAX6/Pax6 in a cell‐autonomous fashion, although the influence of PAX6/Pax6 on the other tissues derived from the ocular mesenchyme is largely unknown. Using transgenic mouse lines in which neural crest cells are genetically marked by LacZ or EGFP, we revealed the extensive contribution of neural crest derived cells (NCDCs) to the ocular tissues. Furthermore, various eye defects in Pax6Sey/+ mouse were accompanied by abnormal distribution of NCDCs from early developmental stages to the adult. In Pax6Sey/+ mouse mice, neural crest cells abnormally migrated into the developing eye in a cell nonautonomous manner at early embryonic stages. These results indicate that normal distribution and integration of NCDCs in ocular tissues depend on a proper dosage of Pax6, and that Pax6Sey/+ eye anomalies are caused by cell autonomous and nonautonomous defects due to Pax6 haploinsufficiency.
Historical biogeography of some river basins in central Mexico evidenced by their goodeine freshwater fishes: a preliminary hypothesis using secondary Brooks parsimony analysis
Authors: Domínguez‐Domínguez Omar , Doadrio Ignacio , Pérez‐Ponce de León Gerardo
Published: July 2006

Aims  Our aim was to uncover and describe patterns of historical biogeography of the main river basins in central Mexico, based on a secondary Brooks parsimony analysis (BPA) of goodeine fishes, and to understand the processes that determine them with respect to the molecular clock of the goodeines and the geological events that have taken place in the region since the Miocene.

Location  The region covered in this study includes central Mexico, mostly the so‐called Mesa Central of Mexico, an area argued to be a transitional zone comprising several major river drainages from their headwaters at high elevations along the Transmexican Volcanic Belt to the coast of the Gulf of Mexico and the Pacific Ocean.

Methods  Based on a previous phylogenetic hypothesis regarding the Goodeidae, we built a data matrix using additive binary coding. First, we conducted a primary BPA to provide general explanations of the historical biogeography of Central Mexico. As ambiguity was found, a secondary BPA was conducted, and some areas were duplicated in order to explain the reticulated history of the area. Area cladograms were obtained by running a parsimony analysis. Instances of vicariance and non‐vicariance processes were described with reference to the cladogram obtained from secondary BPA.

Results  The study area was divided into 18 discrete regions. Primary BPA produced nine equally parsimonious cladograms with 129 steps, and a consistency index (CI) of 0.574. A strict consensus cladogram shows low resolution among some areas, but other area relationships are consistent. For secondary BPA, five of the 18 regions were duplicated (LEA, COT, AYU, CUT, PAN); one was triplicated (BAL); and one was quadruplicated (AME), suggesting that the pattern of distribution of species in these areas reflects multiple independent events. These areas correspond with the regions exhibiting the highest levels of diversification and the most complex geological history, and those for which river piracy events or basin connections have been proposed. The secondary BPA produced a single most parsimonious cladogram with 118 steps, and a CI of 0.858. This cladogram shows that none of the duplicated areas are nested together, reinforcing the idea of a reticulated history of the areas and not a single vicariant event.

Main conclusions  Although our results are preliminary and we cannot establish this as a general pattern, as the BPA is based on a single‐taxon cladogram, resolution obtained in the secondary BPA provides some insights regarding the historical biogeography of this group of fishes in river basins of central Mexico. Secondary BPA indicates that the historical biogeography of central Mexico, as shown by their goodeine freshwater fishes, is complex and is a result of a series of vicariant and non‐vicariant events such as post‐dispersal speciation and post‐speciation dispersal.
Low larval vector survival explains unstable malaria in the western Kenya highlands
Authors: Koenraadt C. J. M. , Paaijmans K. P. , Schneider P. , Githeko A. K. , Takken W.
Published: July 2006

Several highland areas in eastern Africa have recently suffered from serious malaria epidemics. Some models predict that, in the short term, these areas will experience more epidemics as a result of global warming. However, the various processes underlying these changes are poorly understood. We therefore investigated malaria prevalence, malaria vector densities and malaria vector survival in a highland area in western Kenya, ranging from approximately 1550–1650 m altitude. Although only five adult malaria vectors were collected during 180 light traps and 180 resting collections over a 23‐month study period, malaria was prevalent among school children (average parasite prevalence: 10%). During an extensive survey of potential larval habitats, we identified only seven habitats containingAnopheles gambiaeGiles s.l. larvae. Their limited number and low larval densities suggested that their contribution to the adult vector population was small. Experiments on adult and larval survival showed that at this altitude, adult mosquitoes survived inside local houses, but that larval development was severely retarded: only 2 of 500A. gambiaes.l. larvae developed to the pupal stage, whereas all other larvae died prior to pupation. At present, high vector densities are unlikely because of unfavourable abiotic conditions in the area. However, temporary favourable conditions, such as during El Niño years, may increase larval vector survival and may lead to malaria epidemics.
A protein phosphatase 2A from Fagus sylvatica is regulated by GA3 and okadaic acid in seeds and related to the transition from dormancy to germination
Authors: González‐García Mary Paz , Rodríguez Dolores , Nicolás Carlos , Nicolás Gregorio , Lorenzo Oscar
Published: July 2006

Several gibberellic acid (GA3)‐induced cDNA fragments encoding putative serine/threonine protein phosphatase (PP) 2A catalytic subunits were obtained by means of differential reverse transcriptase‐PCR approach. The full‐length clone, named FsPP2A1, isolated from a beechnut cDNA library, exhibited all the features of and homology to members of the PP2A family. By transient expression of FsPP2A1 in tobacco and Arabidopsis cells as a green fluorescent fusion protein, we have obtained evidence supporting the subcellular localization of this protein in both the cytosol and the nucleus. Analysis of FsPP2A1 expression during seed stratification shows that these transcripts increase in the presence of GA3, a treatment proved to be efficient in breaking the dormancy of Fagus sylvatica seeds, but they are almost undetectable in dormant seeds or when dormancy is maintained after treatment with either abscisic acid or the gibberellin biosynthesis inhibitor paclobutrazol. The PP inhibitor okadaic acid (OKA) has a clear effect in decreasing both seed germination and FsPP2A1 expression. Furthermore, FsPP2A1 is specifically expressed in seed tissues, not being detected in other vegetative tissues examined. These results show the regulation of this PP by GA3 and OKA in these seeds. Its relationship with the processes taking place during the transition from dormancy to germination is also discussed.
Growth and photosynthetic responses to salinity in an extreme halophyte, Sarcocornia fruticosa
Authors: Redondo‐Gómez Susana , Wharmby Clare , Castillo Jesús M. , Mateos‐Naranjo Enrique , Luque Carlos J. , De Cires Alfonso , Luque Teresa , Davy Anthony J. , Enrique Figueroa M.
Published: July 2006

Sarcocornia fruticosa (L.) A.J. Scott is found in coastal marshes of south‐west Spain, growing under a very wide range of interstitial soil salinity from 10 mM up to nearly 1000 mM. A glasshouse experiment was designed to investigate the effect of this range of salinities on the morphology and the photosynthetic apparatus of S. fruticosa by measuring growth rate, photosynthetic and non‐photosynthetic area, atrophy of distal branch ends, water status, chlorophyll fluorescence parameters, gas exchange and photosynthetic pigment concentrations. The long‐term effects of salinity on the growth of S. fruticosa were mainly determined by the extent of photosynthetic area rather than the variations in net photosynthetic rate. Photosynthetic area was reduced at 1030 mM as a result of a decrease in the length of the photosynthetic portions. This was induced by fewer internodes and, at salinities lower than 510 mM, smaller internode diameter. Net photosynthetic rate increased as the quantum efficiency of photosystem II decreased in the different salinity treatments, which means that the plant could be increasing photorespiration and/or using cyclic electron transport as additional photoprotective mechanisms. The recorded drop in net photosynthetic rate at higher salinities appeared to be due to a reduction in stomatal conductance. The results indicate that S. fruticosa is capable of tolerating very high and continued exposure to salt, showing its greatest growth rate at 510 mM NaCl.
Glucose‐signalled inhibition of cysteine‐proteases involved in nitrate reductase degradation in oat leaf segments
Authors: Monteoliva Mariela , Guzzo Carla , González Claudio A. , Kenis Juana D.
Published: July 2006

Regulation of nitrate reductase (NR; EC 1.6.6.1) breakdown, measured as loss of maximal activity (MNRA), was studied in leaf segments of 7‐day‐old oat plants in the light for up to 4 h. In segments floating on 1 mM tungstate, NR lost more than 40% of its initial maximal activity. Cycloheximide, high (300 mM) glucose (Glc) and inhibitors of cysteine proteases stabilized NR in situ, suggesting that MNRA decrease was due to the hydrolysis of NR by a short‐lived, glucose‐modulated cysteine protease. Loss of MNRA was accelerated by cantharidin (CTHR) and inhibited by staurosporine, suggesting that NR breakdown required continuous phosphorylation. High glucose inhibited any further MNRA decrease when supplied after a 30‐min pretreatment with CTHR, suggesting that a phosphorylated protein was its target. Isoosmolar polyethylene glycol also stabilized NR but not in the presence of CTHR. Low (30 mM) Glc stabilized NR only in the presence of Ca2+, and CTHR inhibited its effect. EGTA and LaCl3 completely arrested the effects of both high‐ and low‐ Glc. Like low D‐Glc, low L‐Glc (glucose analog not transported) inhibited NR breakdown in the presence of Ca2+, but at high concentration only 2‐deoxyglucose, that is phosphorylated but not further metabolized, and glucose‐6P were effective in the presence of CTHR, suggesting that receptors for high‐ and low‐ Glc were located in different cell compartments. It is proposed that high‐ and low‐ Glc trigger different signalling pathways, with calcium as a common upstream secondary messenger and protein kinases and protein phosphatases being downstream components in the cascade of reactions that modulates NR proteolysis.
Enhanced tolerance to and accumulation of mercury, but not arsenic, in plants overexpressing two enzymes required for thiol peptide synthesis
Authors: Li Yujing , Heaton Andrew C. P. , Carreira Laura , Meagher Richard B.
Published: July 2006

Arsenic and mercury are among the most toxic elemental pollutants in the environment, endangering human health and ecological integrity. Both elements are found in highly thiol‐reactive forms, arsenite and Hg(II), respectively, in plant tissues. Overexpression ofEscherichia coliγ‐glutamylcysteine synthetase (ECS) or glutathione synthetase (GS) inArabidopsis thalianaplants provided significant increases in the thiol peptides glutathione (GSH) and γ‐glutamylcysteine (γ‐EC), and/or phytochelatins (PCs), and some resistance to arsenic and mercury, but no substantial increases in the levels of these elements in above‐ground tissues. In contrast, the co‐expression of ECS and GS in ECS × GS lines produced significant increases in tolerance to toxic levels of mercury. The ECS × GS co‐expression line accumulated 35‐fold more biomass and three‐fold more mercury aboveground than the wild type (WT) when grown on Hg(II). No increases in arsenic accumulation were detected in the ECS × GS line. Increased resistance to and accumulation of mercury apparently resulted from enhanced root concentrations of PCs in ECS × GS co‐expression lines not seen in the wild type or lines expressing ECS or GS alone. Correlations between the levels of arsenic and mercury resistance and accumulation and increases in the accumulation of the various thiol peptides in the ECS, GS and ECS × GS transgenic plant lines are discussed.
Role of sink–source relationships in chrysanthemum flower size and total biomass production
Authors: Carvalho Susana M.P. , Heuvelink Ep , Harbinson Jeremy , Van Kooten Olaf
Published: July 2006

The present work was aimed at understanding and quantifying the effect of sink–source relationships on flower size, using chrysanthemum as a model system. Sink/source ratio was manipulated by flower bud removal (leaving one, two or four flowers, and a control), axillary shoot removal, and varying daily light integral. Furthermore, the influence of flower position within the stem on the flower size was investigated. All means applied to reduce sink/source ratio resulted in a significantly higher individual flower dry mass and area in plants with a fixed number of flowers. Nevertheless, control plants responded to supplementary assimilation light with an increased number of flowers rather than producing larger flowers. Flower position had a negligible effect on flower size in both disbudded and control plants, except that the second‐order lateral flowers were significantly smaller than the first‐order ones. Singly flowered plants without side shoots represented the greatest potential flower size; they had flowers up to 2.4 times heavier than the control plants. Total aerial plant dry mass was only reduced at very low sink strength treatments, whereas flower mass ratio showed a saturating response to the number of flowers per plant. The results indicate that individual flower size is very sensitive to total plant sink strength, but it does not change with plant source strength when the number of flowers is not manipulated.
Does Pseudomonas aeruginosa colonization influence morbidity and mortality in the intensive care unit patient? Experience from an outbreak caused by contaminated oral swabs
Authors: Berdal J.‐E. , Smith‐Erichsen N. , Bjørnholt J. V. , Blomfeldt A. , Bukholm G.
Published: July 2006

Background:  Contaminated oral swabs caused a nationwide monoclonal Pseudomonas aeruginosa outbreak involving 27 Norwegian hospitals. The aim of the study was to study the consequences on mortality and morbidity of the introduction of this P. aeruginosa strain to intensive care unit (ICU) patients.

Methods:  Forty‐four out of 96 patients admitted to the general ICU of Akershus University Hospital during the outbreak, ventilated for more than 24 h and with at least one microbiological sample, were included and followed until death or hospital discharge. All isolated P. aeruginosa strains were genotyped. Demographic data, admission diagnosis, Simplified Acute Physiology Score II (SAPS II), Sequential Organ Failure Assessment (SOFA) score, comorbidities, and antibiotics used in the first week were recorded.

Results:  The outbreak strain was found in 18 patients (41%) of whom seven became infected. Median time to the first positive culture was 4 days. These 18 patients spent a significantly longer time on mechanical ventilation (P =0.03) and had a significantly higher hospital mortality, 55.5% vs. 19.2% (P =0.03), than non‐colonized patients. The number of patients with severe underlying disease was significantly higher (P =0.01) and the decline in SOFA score was significantly slower in the pseudomonas group (P =0.02). Irrespective of colonization status, patients with severe underlying disease had a significantly higher mortality (58%) than those without (16%) (P =0.009).

Conclusion:  Use of contaminated oral swabs led to a high rate of early airways colonization. Patients with severe underlying disease were more likely to become colonized, but whether colonization has any influence on hospital mortality requires further study.
Efficacy of melatonin on offspring liver maturation in pinealectomized pregnant rats subjected to experimental epilepsy
Authors: Ateş Utku , Baka Meral , Uyanikgil Yiǧit , Turgut Mehmet , Yavaşoǧlu Altuǧ , Yurtseven Mine
Published: July 2006

Background and Aims:  In clinical practice, maternal epilepsy is a disabling disease for newborn infants, but current data concerning the effect of epileptic phenomena in pregnant mothers on newborns are still limited. This study was undertaken to investigate the effects of pinealectomy (Px) and melatonin treatments on the morphological changes in the liver tissue of newborn rats following experimental epilepsy during pregnancy.

Methods:  Female Swiss Albino rats were divided into five groups: intact control group; saline control group; epilepsy group; epilepsy plus Px group; and melatonin‐treated epilepsy plus Px group. At one month after Px, an acute grand mal epileptic seizure was induced by penicillin‐G during their pregnancy in all animals except the control groups. On the neonatal first day, newborn rats were perfused with intracardiac fixative solution, and then livers were removed and processed for toluidine blue, periodic acid‐Schiff (PAS) and terminal deoxynucleotidyl transferase‐mediated dUTP nick end‐labeling (TUNEL) reactivity.

Results:  Normal migration and hepatic maturation were determined in the postnatal rat liver in the control groups, while the morphological structure of the liver in the epilepsy and epilepsy plus Px groups corresponded to the early embryonic period. In the melatonin‐treated epilepsy plus Px group, the number of TUNEL positive cells decreased significantly compared to both epilepsy and epilepsy plus Px groups; however, there was no statistically significant difference from the control groups as a result of melatonin activity.

Conclusions:  Some histological findings consistent with chronic fetal distress in newborns of mother rats with epilepsy and Px were observed. Melatonin could be a candidate protective drug for the development of liver tissue in pregnant patients with epilepsy.
11β‐hydroxysteroid dehydrogenase 1 and 2 expression in colon from patients with ulcerative colitis
Authors: Z̆bánková S̆árka , Bryndová Jana , Leden Pavel , Kment Milan , S̆vec Alexander , Pácha Jir̆í
Published: July 2006

Background and Aim:  11β‐hydroxysteroid dehydrogenase (11βHSD) is an enzyme responsible for the interconversion of active 11β‐hydroxysteroids (cortisol) into biologically inactive 11‐oxosteroids (cortisone). The isoform 11βHSD1 operates predominantly as a reductase converting cortisone to cortisol, whereas 11βHSD2 catalyzes oxidation of cortisol to cortisone. This mechanism of peripheral metabolism of glucocorticoids has been suggested to be involved in increasing the availability of anti‐ inflammatory glucocorticoids as a response to inflammatory stimuli. The aim of this study therefore was to investigate the impact of inflammatory bowel disease on the expression of colonic 11βHSD1 and 11βHSD2.

Methods:  Quantitative real‐time RT‐PCR was used to assess messenger RNA for 11βHSD1 and 11βHSD2 in bioptic samples taken from patients with ulcerative colitis and in healthy controls, and in colon of rats with colitis induced by dextran sulfate sodium (DSS). Rat colonic fragments were used for assessment of local metabolism of glucocorticoids.

Results:  In both human and rat specimens colitis up‐regulated the expression of colonic 11βHSD1 mRNA and down‐regulated 11βHSD2 mRNA. A similar pattern was observed at the level of local metabolism of corticosterone. Oxidation of corticosterone to 11‐dehydrocorticosterone was decreased and reduction of 11‐dehydrocorticosterone to corticosterone was increased in colonic tissue of rats with DSS‐colitis.

Conclusions:  Colonic inflammation induces local glucocorticoid activation via 11βHSD1 and impairs glucocorticoid inactivation via 11βHSD2. The observed changes indicate a role for local metabolism of glucocorticoids in the control of colonic inflammation.
Gastrointestinal stromal tumors: Usefulness of immunohistochemistry, flow cytometry and fluorescence in situ hybridization
Authors: Fontana Maria Grazia , Rossi Elisa , Bassotti Gabrio , Aquilano Maria Costanza , Cadei Morris , Grigolato Piergiovanni , Villanacci Vincenzo
Published: July 2006

Background and Aims:  Gastrointestinal stromal tumors (GIST) constitute a group of primary mesenchymal tumors of the gastrointestinal tract, known for their diversity in clinical behavior and the difficulties in determining malignancy and prognosis. This retrospective study evaluated a series of GIST by means of immunohistochemical techniques, flow cytometry and fluorescence in situ hybridization (FISH).

Methods:  Nine patients with GIST were analyzed for tumor size, mitotic count and CD117, CD34, MIB‐1 with immunohistochemistry. In addition, the GIST were tested with FISH for chromosomes 8 and 17 and DNA index was evaluated by flow cytometry.

Results:  The findings confirmed the usefulness of CD117 and CD34 in diagnosing GIST and the prognostic role of MIB‐1, but do not support a correlation between aneuploidy in flow cytometry and poor outcome. The FISH results suggest close follow‐up for patients with benign GIST with a numerical alteration of chromosome 8. The technique could select patients with tumors at high‐risk with aneusomy of chromosome 17.

Conclusion:  This study shows the possible application of FISH to the evaluation of patients with GIST, in addition to analysis of morphological features.
Open label trial of clarithromycin therapy in Japanese patients with Crohn’s disease
Authors: Inoue Satoko , Nakase Hiroshi , Matsuura Minoru , Ueno Satoru , Uza Norimitsu , Kitamura Hiroshi , Mikami Sakae , Tamaki Hiroyuki , Kasahara Katsuhiro , Chiba Tsutomu
Published: July 2006

Background and Aim:  The pathogenesis of Crohn’s disease is unclear, but many studies suggest that luminal bacteria play an important role in chronic intestinal inflammation in patients with this condition. Clarithromycin is a macrolide antibiotic with immunomodulatory activity. The aim of this study was to evaluate the effect of clarithromycin therapy in Japanese patients with Crohn’s disease.

Methods:  Fourteen patients with active Crohn’s disease (12 with ileocolonic, one with colonic, one with small bowel type) were treated with oral clarithromycin 200 mg twice daily for 4 weeks. Patients who showed a clinical response within 4 weeks continued the therapy for up to 24 weeks. Four patients also received azathioprine. Clinical activity was assessed with the Crohn’s Disease Activity Index (CDAI) at entry and at 4, 12, and 24 weeks after starting clarithromycin.

Results:  The mean CDAI score at entry was 343.5. Within 4 weeks, eight (57.1%) of the 14 patients showed clinical improvement, and five (35.7%) of the eight patients achieved remission. All of those eight patients continued clarithromycin therapy after 4 weeks, and six (42.9%) were in clinical remission at 12 weeks. Of the 14 total patients, four (28.6%) continued clarithromycin for more than 24 weeks, and have remained in remission. Patients who received azathioprine concomitantly had a better response to clarithromycin therapy. No severe side‐effects were observed during the study period.

Conclusions:  This open label study showed encouraging results of clarithromycin therapy in Japanese patients with active Crohn’s disease.
Molecular analysis of ammonia‐oxidizing bacteria community in intermittent aeration sequencing batch reactors used for animal wastewater treatment
Authors: Otawa Kenichi , Asano Ryoki , Ohba Yasuhiko , Sasaki Takako , Kawamura Eisuke , Koyama Futoshi , Nakamura Sakujiro , Nakai Yutaka
Published: July 2006

Bacterial communities and betaproteobacterial ammonia‐oxidizing bacteria (AOB) communities were evaluated seasonally in an intermittent‐aeration sequencing batch process (SBR, plant A) and in 12 other livestock wastewater treatment plants (WWTP): eight SBRs and four conventional activated‐sludge systems. Microbial communities were analysed by reverse transcription polymerase chain reaction followed by denaturing‐gradient gel electrophoresis (DGGE) and the construction of clone libraries for 16S rRNA and ammonia monooxygenase (amoA) genes. In plant A, the dominant bacteria were as‐yet‐uncultured bacteria of Bacteroidetes and Proteobacteria, and the DGGE profiles showed that the bacterial communities were stable during a given treatment cycle, but changed seasonally. In betaproteobacterial AOB communities, two AOB phylotypes (members of the Nitrosomonas ureae–oligotropha–marina cluster) were dominant during the seasons in plant A. Although the dominant AOB phylotypes differed among the 13 WWTPs, dominance by one or two AOB phylotypes was commonly observed in all plants. Sequencing of the DGGE bands indicated that amoA sequences belonging to the Nitrosomonas europaea–eutropha cluster were dominant in 11 plants, where the ammonia‐nitrogen concentration was high in the raw wastewater, whereas those belonging to the Nitrosomonas ureae–oligotropha–marina cluster were dominant in two plants where the concentration was relatively low. Even though we detected many minor amoA sequences by means of five clone libraries for the A to D plants, no libraries comprised both amoA sequences belonging to the two clusters, indicating that the dominant AOBs were defined by cluster level in each plant.
Pressure affects transcription profiles of Methanocaldococcus jannaschii despite the absence of barophilic growth under gas‐transfer limitation
Authors: Boonyaratanakornkit Boonchai , Córdova Jesús , Park Chan Beum , Clark Douglas S.
Published: July 2006

Barophilic growth of the hyperthermophilic methanarchaeon Methanocaldococcus jannaschii occurred when gas‐substrate availability did not limit growth. In contrast, when growth was limited by gas transfer, no enhancement of growth was evident and a stress response was exhibited at both high and low pressure. A pressure‐induced transcriptional response was evident, regardless of whether growth was enhanced by pressure. Potential high‐pressure adaptation of a barophilic organism can thus occur at the transcriptional level, even though the cells are stressed by low substrate availability and do not exhibit accelerated growth.
Long‐term results of surgically treated traumatic rectourethral fistulas
Authors: Barisic G. I. , Krivokapic Z. V.
Published: July 2006

Objective  Rectourethral fistulas are uncommon, usually iatrogenic injuries that are demanding to treat. We present the challenging problems involving the treatment of rectourethral fistulas caused by war wounds.

Materials and methods  In the period 1991–1996, during the war in Croatia and Bosnia, six patients with rectourethral fistulas caused by war injuries were operated in our institution by the same surgeon. All patients were young males with a mean age of 24.6 years. In all patients, double diversion (diversion colostomy and cystostomy) was performed at the time of the injury in military hospitals. In three patients, multiple unsuccessful operations were performed in other institutions to close rectourethral fistula. We found urethrocystography and proctoscopy as the most reliable diagnostic studies and performed them in all patients. In first three patients, we performed transanal repair with anterior rectal wall advancement flap. Because it failed in all three patients, we performed York–Mason trans‐sphincteric approach and anterior rectal wall advancement flap after which rectourethral fistula closed in all patients. Because of the satisfactory results, we performed the same procedure in other three patients.

Results  In all patients rectourethral fistula healed 2 months after the operation. Closure of diverting colostomy was performed after urethrocystography and proctoscopy proved that the rectourethral fistula has healed. There were no operative deaths and no major complications. Urethral stenosis developed in one patient and was successfully managed by dilatation.

Conclusion  We believe that York–Mason trans‐sphincteric approach offers straightforward access through healthy tissues and good fistula visualization. Anterior rectal wall advancement flap can easily be performed and offer good chances for definitive closure of the rectourethral fistula.
STEINDL ON IMPERFECT COMPETITION: THE ROLE OF TECHNICAL CHANGE
Authors: Bloch Harry
Published: July 2006

Josef Steindl offers an innovative dynamic analysis of competition in Maturity and Stagnation in American Capitalism, with a key role for technical change. However, in his later writings he suggests that he had not gone far enough and that his account was not ‘sufficiently dynamic’, noting particularly his neglect of fundamental issues in technological development. Here, we critically examine the nature of technical change in Steindl’s analysis, pointing to ambiguities and contradictions that arise. Standard characterizations of the nature of technical change are then introduced and used to further integrate technical change into Steindl’s analysis of competition.
The long march of history: Farm wages, population, and economic growth, England 1209–18691
Authors: CLARK GREGORY
Published: July 2006

The article forms three series for English farm workers from 1209–1869: nominal day wages, the implied marginal product of a day of farm labour, and the purchasing power of a day’s wage in terms of farm workers’ consumption. These series suggest that labour productivity in English agriculture was already high in the middle ages. Furthermore, they fit well with one method of estimating medieval population that suggests a peak English population c.1300 of nearly 6 million. Lastly, they imply that both agricultural technology and the general efficiency of the economy were static from 1250 till 1600. Economic changes were in these years entirely a product of demographic shifts. From 1600 to 1800, technological advance in agriculture provided an alternative source of dynamism in the English economy.
Where there’s muck, there’s brass:1 the market for manure in the industrial revolution2
Authors: BRUNT LIAM
Published: July 2006

This article presents the first systematic analysis of off‐farm sources of nitrogen, such as urban and industrial waste, used in English agriculture during the industrial revolution, arguing that their use was widespread and intensive by 1700 and that there was only modest growth in their use up to 1840. It explains the pattern of use by supply and demand factors, and develops a new method to estimate the overall impact on wheat yields. It estimates that throughout the period 1700–1840 yields were 20 per cent higher than they would have been if no off‐farm manures had been used.
Tauroursodeoxycholic acid modulates p53‐mediated apoptosis in Alzheimer's disease mutant neuroblastoma cells
Authors: Ramalho Rita M. , Borralho Pedro M. , Castro Rui E. , Solá Susana , Steer Clifford J. , Rodrigues Cecília M. P.
Published: July 2006

Early onset familial Alzheimer's disease (FAD) is linked to autosomal dominant mutations in the amyloid precursor protein (APP) and presenilin 1 and 2 (PS1 and PS2) genes. These are critical mediators of total amyloid β‐peptide (Aβ) production, inducing cell death through uncertain mechanisms. Tauroursodeoxycholic acid (TUDCA) modulates exogenous Aβ‐induced apoptosis by interfering with E2F‐1/p53/Bax. Here, we used mouse neuroblastoma cells that express either wild‐type APP, APP with the Swedish mutation (APPswe), or double‐mutated human APP and PS1 (APPswe/ΔE9), all exhibiting increased Aβ production and aggregation. Cell viability was decreased in APPswe and APPswe/ΔE9 but was partially reversed by z‐VAD.fmk. Nuclear fragmentation and caspase 2, 6 and 8 activation were also readily detected. TUDCA reduced nuclear fragmentation as well as caspase 2 and 6, but not caspase 8 activities. p53 activity, and Bcl‐2 and Bax changes, were also modulated by TUDCA. Overexpression of p53, but not mutant p53, in wild‐type and mutant neuroblastoma cells was sufficient to induce apoptosis, which, in turn, was reduced by TUDCA. In addition, inhibition of the phosphatidylinositide 3′‐OH kinase pathway reduced TUDCA protection against p53‐induced apoptosis. In conclusion, FAD mutations are associated with the activation of classical apoptotic pathways. TUDCA reduces p53‐induced apoptosis and modulates expression of Bcl‐2 family.
Loss of the cellular prion protein affects the Ca2+ homeostasis in hippocampal CA1 neurons
Authors: Fuhrmann Martin , Bittner Tobias , Mitteregger Gerda , Haider Nicole , Moosmang Sven , Kretzschmar Hans , Herms Jochen
Published: July 2006

Previous neurophysiological studies on prion protein deficient (Prnp–/–) mice have revealed a significant reduction of slow afterhyperpolarization currents (sIAHP) in hippocampal CA1 pyramidal cells. Here we aim to determine whether loss of PrPC. directly affects the potassium channels underlying sIAHP or if sIAHP is indirectly disturbed by altered intracellular Ca2+ fluxes. Patch‐clamp measurements and confocal Ca2+ imaging in acute hippocampal slice preparations of Prnp–/– mice compared to littermate control mice revealed a reduced Ca2+ rise in CA1 neurons lacking PrPC following a depolarization protocol known to induce sIAHP. Moreover, we observed a reduced Ca2+ influx via l‐type voltage gated calcium channels (VGCCs). No differences were observed in the protein expression of the pore forming α1 subunit of VGCCs Prnp–/– mice. Surprisingly, the β2 subunit, critically involved in the transport of the α1 subunit to the plasma membrane, was found to be up‐regulated in knock out hippocampal tissue. On mRNA level however, no differences could be detected for the α1C, D and β2–4 subunits. In conclusion our data support the notion that lack of PrPC. does not directly affect the potassium channels underlying sIAHP, but modulates these channels due to its effect on the intracellular free Ca2+ concentration via a reduced Ca2+ influx through l‐type VGCCs.
Inhibition of histone deacetylation protects wild‐type but not gelsolin‐deficient neurons from oxygen/glucose deprivation
Authors: Meisel Andreas , Harms Christoph , Yildirim Ferah , Bösel Julian , Kronenberg Golo , Harms Ulrike , Fink Klaus B. , Endres Matthias
Published: July 2006

Histone acetylation and deacetylation participate in the epigenetic regulation of gene expression. In this paper, we demonstrate that pre‐treatment with the histone deacetylation inhibitor trichostatin A (TSA) enhances histone acetylation in primary cortical neurons and protects against oxygen/glucose deprivation, a model for ischaemic cell death in vitro. The actin‐binding protein gelsolin was identified as a mediator of neuroprotection by TSA. TSA enhanced histone acetylation of the gelsolin promoter region, and up‐regulated gelsolin messenger RNA and protein expression in a dose‐ and time‐dependent manner. Double‐label confocal immunocytochemistry visualized the up‐regulation of gelsolin and histone acetylation within the same neuron. Together with gelsolin up‐regulation, TSA pre‐treatment decreased levels of filamentous actin. The neuroprotective effect of TSA was completely abolished in neurons lacking gelsolin gene expression. In conclusion, we demonstrate that the enhancement of gelsolin gene expression correlates with neuroprotection induced by the inhibition of histone deacetylation.
A role for P2X7in microglial proliferation
Authors: Bianco Fabio , Ceruti Stefania , Colombo Alessio , Fumagalli Marta , Ferrari Davide , Pizzirani Cinzia , Matteoli Michela , Di Virgilio Francesco , Abbracchio Maria P. , Verderio Claudia
Published: July 2006

Microglia, glial cells with an immunocompetent role in the CNS, react to stimuli from the surrounding environment with alterations of their phenotypic response. Amongst other activating signals, the endotoxin lipopolysaccharide (LPS) is widely used as a tool to mimic bacterial infection in the CNS. LPS‐activated microglia undergo dramatic changes in cell morphology/activity; in particular, they stop proliferating and differentiate from resting to effector cells. Activated microglia also show modifications of purinoreceptor signalling with a significant decrease in P2X7expression. In this study, we demonstrate that the down‐regulation of the P2X7receptor in activated microglia may play an important role in the antiproliferative effect of LPS. Indeed, chronic blockade of the P2X7receptor by antagonists (oxidized ATP, KN62 and Brilliant Blue G), or treatment with the ATP‐hydrolase apyrase, severely decreases microglial proliferation, down‐regulation of P2X7receptor expression by small RNA interference (siRNA) decreases cell proliferation, and the proliferation of P2X7‐deficient N9 clones and primary microglia, in which P2X7expression is down‐regulated by siRNA, is unaffected by either LPS or P2X7antagonists. Furthermore, flow cytometric analysis indicates that exposure to oxidized ATP or treatment with LPS reversibly decreases cell cycle progression, without increasing the percentage of apoptotic cells. Overall, our data show that the P2X7receptor plays an important role in controlling microglial proliferation by supporting cell cycle progression.
Acyl‐based anandamide uptake inhibitors cause rapid toxicity to C6 glioma cells at pharmacologically relevant concentrations
Authors: De Lago Eva , Gustafsson Sofia B. , Fernández‐Ruiz Javier , Nilsson Jonas , Jacobsson Stig O. P. , Fowler Christopher J.
Published: July 2006

Compounds blocking the uptake of the endogenous cannabinoid anandamide (AEA) have been used to explore the functions of the endogenous cannabinoid system in the CNS bothin vivoandin vitro. In this study, the effects of four commonly used acyl‐based uptake inhibitors [N‐(4‐hydroxyphenyl)arachidonylamide (AM404),N‐(4‐hydroxy‐2‐methylphenyl) arachidonoyl amide (VDM11), (5Z,8Z,11Z,14Z)‐N‐(3‐furanylmethyl)‐5,8,11,14‐eicosatetraenamide (UCM707) and (9Z)‐N‐[1‐((R)‐4‐hydroxybenzyl)‐2‐hydroxyethyl]‐9‐octadecen‐amide (OMDM2)] and the related compound arvanil on C6 glioma cell viability were investigated. All five compounds reduced the ability of the cells to accumulate calcein, reduced the total nucleic acid content and increased the activity of lactate dehydrogenase recovered in the cell medium. AM404 (10 µm) and VDM11 (10 µm) acted rapidly, reducing cell viability after 3 h of exposure when cell densities of 5000 per well were used. In contrast, UCM707 (30 µm), OMDM2 (10 µm) and the related compound arvanil (10 µm) produced a more slowly developing effect on cell viability, although robust effects were seen after 6–9 h of exposure. At higher cell densities, the toxicities of AM404 and UCM707 were reduced. Comparison of the compounds with arachidonic acid, arachidonic acid methyl ester, AEA, arachidonoyl glycine and oleic acid suggested that the toxicity of the arachidonoyl‐based compounds was related primarily to the acyl side‐chain rather than the head group. A variety of pre‐treatments blocking possible metabolic pathways and receptor targets were tested, but the only consistent protective treatment against the effects of these compounds was the antioxidantN‐acetyl‐l‐cysteine. It is concluded that AM404, VDM11, UCM707 and OMDM2 produce a rapid loss of C6 glioma cell viability over the same concentration range as is required for the inhibition of AEA uptakein vitro, albeit with a longer latency. Such effects should be kept in mind when acyl‐derived compounds are used to probe the function of the endocannabinoid system in the CNS, particularly in chronic administration protocols.
Effectiveness of extracellular lactate/pyruvate for sustaining synaptic vesicle proton gradient generation and vesicular accumulation of GABA
Authors: Tarasenko A. S. , Linetska M. V. , Storchak L. G. , Himmelreich N. H.
Published: July 2006

The effects of extracellular monocarboxylates pyruvate and lactate on membrane potentials, acidification and neurotransmitter filling of synaptic vesicles were investigated in experiments with rat brain synaptosomes using [3H]GABA and fluorescent dyes, potential‐sensitive rhodamine 6G and pH‐sensitive acridine orange. In experiments investigating accumulation of acridine orange in synaptic vesicles within the synaptosomes, monocarboxylates, similarly to glucose, ensured generation of the vesicle proton gradient by available and recycled vesicles, and pyruvate demonstrated the highest efficacy. An increase in the level of proton gradient correlated with enhanced accumulation of [3H]GABA in synaptic vesicles and resulted in enlarged exocytosis and attenuated the transporter‐mediated [3H]GABA release. Pyruvate added to glucose‐contained medium caused more active binding of rhodamine 6G by synaptosomes that reflected mitochondrial membrane hyperpolarization, and this intensification of nerve terminal energy metabolism resulted in an increase in total ATP content by ∼25%. Pyruvate also prolonged the state of metabolic competence of nerve terminal preparations, keeping the mitochondrial potential and synaptic vesicle proton gradient at steady levels over a long period of time. Thus, besides glucose, the extracellular monocarboxylates pyruvate and lactate can provide sufficient support of energy‐dependent processes in isolated nerve terminals, allowing effective functioning of neurotransmitter release and reuptake systems.
Bone associated with implants in diabetic and insulin‐treated rats
Authors: McCracken Michael S. , Aponte‐Wesson Ruth , Chavali Ramakiran , Lemons Jack E.
Published: July 2006

Objectives: Diabetes is an increasingly prevalent disease with oral health manifestations. While diabetes clearly has an affect on bone, its impact on the healing of bone associated with dental implants is not completely understood. The purpose of this study was to measure bone response to implants in uncontrolled and insulin‐controlled diabetic rats.

Material and methods: One hundred and fifty‐two rats were divided into control, diabetic, and insulin groups. Rats received streptozotocin (65 mg/kg) to induce diabetes; animals in the insulin group also received a subcutaneous slow‐release insulin implant. Titanium alloy implants (1.5 × 8 mm) were placed in the proximal tibiae of animals. Implants were harvested at 2, 7, 14, and 24 days and examined histologically. Bone or bone‐like tissue adjacent to implants was quantified as a percent. Data were compared using a two‐way analysis is variance (ANOVA) with time and treatment as primary independent factors.

Results: Time and treatment were significant factors in predicting bone response to implants (P<0.0001). Mean bone volume peaked at day 7 and decreased over time to day 24. Mean bone volume percent at 2, 7, 14, and 24 days (±SD) was 8.2 (±8), 22.9 (±8), 18.8 (±10), and 14.9 (±9), respectively. Mean total bone volume percent (adjusted for day) for control, diabetic, and insulin groups (±SD) was 12.4 (±9), 22.6 (±10), and 17 (±7), respectively. Bone volume adjacent to implants in diabetic rats was significantly greater than controls (P<0.05). Diabetic animals treated with insulin were not statistically different from controls.

Conclusions: Induction of diabetes with STZ is associated with increased bone response compared with controls. This response was mediated by treatment with insulin.
Interferon‐γ secreted from peripheral blood mononuclear cells as a possible diagnostic marker for allergic contact dermatitis to gold
Authors: Christiansen Jenny , Färm Gunilla , Eid‐Forest Ruth , Anderson Chris , Cederbrant Karin , Hultman Per
Published: July 2006

10% of patch‐tested patients have a positive reaction to gold. Most lack clinical symptoms, but allergic contact dermatitis (ACD) to gold is increasing. In this study, 77 dermatological outpatients were divided into 3 groups depending on epicutaneous patch test outcomes: a group positive to gold (EPI+), a group negative to gold (EPI−), and a group with irritant reactions to gold (EPI‐IR). Lymphocytes were stimulated in vitro with gold sodium thiosulfate. Proliferation was assessed using the lymphocyte transformation test (LTT), and cytokine secretion was assessed using a multibead array (Luminex®; Linco Research Inc., St. Charles, MO, USA), in order to evaluate whether an in vitro method with high diagnostic accuracy could be devised. The EPI+ group showed a significantly increased secretion of interferon (IFN)‐γ, interleukin (IL)‐2, and IL‐13 and also showed a significantly higher stimulation indexes for LTT, compared to the other 2 subject groups. Sensitivity and specificity were calculated for all methods individually and combined, but IFN‐γ assessment alone was the most accurate method for identifying ACD to gold, with sensitivity and specificity of 81.8% and 82.1%, respectively. This method also identified 87.5% of the EPI‐IR subjects as non‐allergic. Therefore, assessment of secretion of IFN‐γ should be a valuable complement to patch test for diagnosing gold allergy.