bluuebunny/crossref_metadata_2025 huggingface dataset:
Modulating progenitor accumulation attenuates lung angiogenesis in a mouse model of asthma
Authors: Doyle T.M. , Ellis R. , Park H.J. , Inman M.D. , Sehmi R.
Published: November 2010

Asthmatic responses are associated with the lung homing of bone marrow (BM)-derived progenitors implicated as effectors of disease pathology. Studies have shown that increases in lung extracted vascular endothelial progenitor cells (VEPCs) correlate with airway angiogenesis and declining lung function. We investigated the effect of modulating lung homing of VEPCs on tissue remodelling and airway hyperresponsiveness (AHR).

BALB/c mice were sensitised to ovalbumin, subjected to a chronic exposure protocol and given early concurrent or delayed treatment with a modulator of progenitor traffic, AMD3100 (CXC chemokine receptor 4 antagonist; inhibits chemotactic activity of stromal-derived factor-1α on VEPCs). After ovalbumin challenge, early haemopoietic stem cells (HSCs) and VEPCs were enumerated along with indices of airway inflammation, lung morphometry and AHR.

Following ovalbumin challenge, there was a decrease in BM and an associated increase in the lung tissue-extracted HSCs and VEPCs, together with increases in airway eosinophilia, microvessel density and AHR. These outcomes were significantly inhibited by early concurrent treatment with AMD3100. Where lung disease was established, delayed treatment with AMD3100 significantly attenuated HSC numbers and lung angiogenesis but only partially reversed sustained AHR compared with untreated ovalbumin-exposed mice.

Progenitor lung homing is associated with the development of asthma pathology, and early modulation of this accumulation can prevent airway remodelling and lung dysfunction.
Iron-sparing Response of Mycobacterium avium subsp. paratuberculosis is strain dependent
Authors: Janagama Harish K , Senthilkumar  , Bannantine John P , Kugadas Abirami , Jagtap Pratik , Higgins LeeAnn , Witthuhn Bruce A , Sreevatsan Srinand
Published: November 2010

Background

Two genotypically and microbiologically distinct strains of Mycobacterium avium subsp. paratuberculosis (MAP) exist - S and C MAP strains that primarily infect sheep and cattle, respectively. Concentration of iron in the cultivation medium has been suggested as one contributing factor for the observed microbiologic differences. We recently demonstrated that S strains have defective iron storage systems, leading us to propose that these strains might experience iron toxicity when excess iron is provided in the medium. To test this hypothesis, we carried out transcriptional and proteomic profiling of these MAP strains under iron-replete or -deplete conditions.

Results

We first complemented M. smegmatis ΔideR with IdeR of C MAP or that derived from S MAP and compared their transcription profiles using M. smegmatis mc

2

155 microarrays. In the presence of iron, sIdeR repressed expression of bfrA and MAP2073c, a ferritin domain containing protein suggesting that transcriptional control of iron storage may be defective in S strain. We next performed transcriptional and proteomic profiling of the two strain types of MAP under iron-deplete and -replete conditions. Under iron-replete conditions, C strain upregulated iron storage (BfrA), virulence associated (Esx-5 and antigen85 complex), and ribosomal proteins. In striking contrast, S strain downregulated these proteins under iron-replete conditions. iTRAQ (isobaric tag for relative and absolute quantitation) based protein quantitation resulted in the identification of four unannotated proteins. Two of these were upregulated by a C MAP strain in response to iron supplementation. The iron-sparing response to iron limitation was unique to the C strain as evidenced by repression of non-essential iron utilization enzymes (aconitase and succinate dehydrogenase) and upregulation of proteins of essential function (iron transport, [Fe-S] cluster biogenesis and cell division).

Conclusions

Taken together, our study revealed that C and S strains of MAP utilize divergent metabolic pathways to accommodate in vitro iron stress. The knowledge of the metabolic pathways these divergent responses play a role in are important to 1) advance our ability to culture the two different strains of MAP efficiently, 2) aid in diagnosis and control of Johne's disease, and 3) advance our understanding of MAP virulence.
The development and evaluation of single cell suspension from wheat and barley as a model system; a first step towards functional genomics application
Authors: Dong Jing , Bowra Steve , Vincze Eva
Published: November 2010

Background

The overall research objective was to develop single cell plant cultures as a model system to facilitate functional genomics of monocots, in particular wheat and barley. The essential first step towards achieving the stated objective was the development of a robust, viable single cell suspension culture from both species.

Results

We established growth conditions to allow routine culturing of somatic cells in 24 well microtiter plate format. Evaluation of the wheat and barley cell suspension as model cell system is a multi step process. As an initial step in the evaluation procedure we chose to study the impact of selected abiotic stress elicitors at the physiological, biochemical and molecular level. We report the results of osmotic stress imposed by NaCl and PEG. As proline is an important osmoprotectant of the cereal cells, colorimetric assay for proline detection was developed for small volumes (200 μl). We performed RT-PCR experiments to study the change in the expression of the genes encoding Δ1-pyrroline-5-carboxylate synthetase (P5CS) and Δ1-pyrroline-5-carboxylate reductase (PC5R) in response to abiotic stress.

Conclusions

We found differences between the wheat and barley suspension cultures, barley being more tolerant to the applied osmotic stresses. We suggested a model to explain the obtained differences in stress tolerance between the two species. The suspension cell cultures have proven useful for determining changes in proline concentration and expression level of genes (P5CS, P5CR) under various treatments and we suggest that the cells can be used as a model host system to study gene expression and regulation in monocots.
High number of CD45RO+ tumor infiltrating lymphocytes is an independent prognostic factor in non-metastasized (stage I-IIA) esophageal adenocarcinoma
Authors: Rauser Sandra , Langer Rupert , Tschernitz Sebastian , Gais Peter , Jütting Uta , Feith Marcus , Höfler Heinz , Walch Axel
Published: November 2010

Background

The validation of novel prognostic indicators is of greatest interest for the management of esophageal adenocarcinoma (Barrett's cancer), particularly for non-metastasized (stage I-IIA) disease. The prognostic role of tumor infiltrating T-lymphocytes (TILs) in Barrett's cancer has not been reported so far. Here we evaluated the impact of TILs on survival, recurrence, and metastasis in Barrett's cancer, particularly in stage I-IIA patients.

Methods

The levels of the adaptive immune markers CD3, CD8, and CD45RO were analyzed by immunohistochemistry and image analysis in tissue microarrays consisting of tumor tissues of 118 patients with primary resected Barrett's cancer. The findings were correlated with clinicopathological parameters including patient outcome.

Results

In multivariate analysis, a low density of intratumoral CD45RO+ immune cells was an independent unfavorable factor for disease-free survival in stages I-IIA patients (P = 0.004, RR = 4.7, 95% CI = 1.6-13.5) as well in the entire cohort (P = 0.048, RR = 2.0, 95% CI = 1.0-4.0). High CD3+ and CD45RO+ levels were associated with prolonged disease-free survival and overall survival as well with low recurrence rates of disease (P = 0.005 and P = 0.018, respectively). In addition, low CD3+ levels were correlated with a higher frequency of lymph node metastasis (P = 0.025).

Conclusions

This study demonstrates that the density of CD45RO+ TILs is an independent prognostic factor in non-metastasized (stage I-IIA) Barrett's cancer patients and indicates an important role for the adaptive immunologic microenvironment. The inclusion of CD45RO+ density may help to improve the management of stage I-IIA Barrett's cancer.
Responsiveness and minimal important differences after revision total hip arthroplasty
Authors: Shi Hon-Yi , Chang Je-Ken , Wong Chi-Yin , Wang Jun-Wen , Tu Yuan-Kun , Chiu Herng-Chia , Lee King-Teh
Published: November 2010

Background

The health-related quality of life (HRQoL) is currently weighted more heavily when evaluating health status, particularly regarding medical treatments and interventions. However, it is rarely used by physicians to compare responsiveness. Additionally, responsiveness estimates derived by the Harris Hip Score (HHS) and the Short Form 36 (SF-36) before and after revision total hip arthroplasty (THA) have not been clinically compared. This study compared responsiveness and minimal important differences (MID) between HHS and SF-36.

Methods

All revision THA patients completed the disease-specific HHS and the generic SF-36 before and 6 months after surgery. Scores using these instruments were interpreted by generalized estimating equation (GEE) before and after revision THA. The bootstrap estimation and modified Jacknife test were used to derive 95% confidence intervals for differences in the responsiveness estimates.

Results

Comparisons of effect size (ES), standardized response means (SRM), relative efficiency (RE) (>1) and MID indicated that the responsiveness of HHS was superior to that of SF-36. The ES and SRM for pain and physical functions in the HHS were significantly larger than those of the SF-36 (p < 0.001).

Conclusion

The data in this study indicated that clinicians and health researchers should weight disease-specific measures more heavily than generic measures when evaluating treatment outcomes.
Production of gamma-aminobutyric acid by Lactobacillus brevis NCL912 using fed-batch fermentation
Authors: Li Haixing , Qiu Ting , Huang Guidong , Cao Yusheng
Published: November 2010

Background

Gamma-aminobutyric acid is a major inhibitory neurotransmitter in mammalian brains, and has several well-known physiological functions. Lactic acid bacteria possess special physiological activities and are generally regarded as safe. Therefore, using lactic acid bacteria as cell factories for gamma-aminobutyric acid production is a fascinating project and opens up a vast range of prospects for making use of GABA and LAB. We previously screened a high GABA-producer Lactobacillus brevis NCL912 and optimized its fermentation medium composition. The results indicated that the strain showed potential in large-scale fermentation for the production of gamma-aminobutyric acid. To increase the yielding of GABA, further study on the fermentation process is needed before the industrial application in the future. In this article we investigated the impacts of pyridoxal-5'-phosphate, pH, temperature and initial glutamate concentration on gamma-aminobutyric acid production by Lactobacillus brevis NCL912 in flask cultures. According to the data obtained in the above, a simple and effective fed-batch fermentation method was developed to highly efficiently convert glutamate to gamma-aminobutyric acid.

Results

Pyridoxal-5'-phosphate did not affect the cell growth and gamma-aminobutyric acid production of Lb. brevis NCL912. Temperature, pH and initial glutamate concentration had significant effects on the cell growth and gamma-aminobutyric acid production of Lb. brevis NCL912. The optimal temperature, pH and initial glutamate concentration were 30-35°C, 5.0 and 250-500 mM. In the following fed-batch fermentations, temperature, pH and initial glutamate concentration were fixed as 32°C, 5.0 and 400 mM. 280.70 g (1.5 mol) and 224.56 g (1.2 mol) glutamate were supplemented into the bioreactor at 12 h and 24 h, respectively. Under the selected fermentation conditions, gamma-aminobutyric acid was rapidly produced at the first 36 h and almost not produced after then. The gamma-aminobutyric acid concentration reached 1005.81 ± 47.88 mM, and the residual glucose and glutamate were 15.28 ± 0.51 g L-1 and 134.45 ± 24.22 mM at 48 h.

Conclusions

A simple and effective fed-batch fermentation method was developed for Lb. brevis NCL912 to produce gamma-aminobutyric acid. The results reveal that Lb. brevis NCL912 exhibits a great application potential in large-scale fermentation for the production of gamma-aminobutyric acid.
Effect of 3D-scaffold formation on differentiation and survival in human neural progenitor cells
Authors: Ortinau Stefanie , Schmich Jürgen , Block Stephan , Liedmann Andrea , Jonas Ludwig , Weiss Dieter G , Helm Christiane A , Rolfs Arndt , Frech Moritz J
Published: November 2010

Background

3D-scaffolds have been shown to direct cell growth and differentiation in many different cell types, with the formation and functionalisation of the 3D-microenvironment being important in determining the fate of the embedded cells. Here we used a hydrogel-based scaffold to investigate the influences of matrix concentration and functionalisation with laminin on the formation of the scaffolds, and the effect of these scaffolds on human neural progenitor cells cultured within them.

Methods

In this study we used different concentrations of the hydrogel-based matrix PuraMatrix. In some experiments we functionalised the matrix with laminin I. The impact of concentration and treatment with laminin on the formation of the scaffold was examined with atomic force microscopy. Cells from a human fetal neural progenitor cell line were cultured in the different matrices, as well as in a 2D culture system, and were subsequently analysed with antibody stainings against neuronal markers. In parallel, the survival rate of the cells was determined by a live/dead assay.

Results

Atomic force microscopy measurements demonstrated that the matrices are formed by networks of isolated PuraMatrix fibres and aggregates of fibres. An increase of the hydrogel concentration led to a decrease in the mesh size of the scaffolds and functionalisation with laminin promoted aggregation of the fibres (bundle formation), which further reduces the density of isolated fibres. We showed that laminin-functionalisation is essential for human neural progenitor cells to build up 3D-growth patterns, and that proliferation of the cells is also affected by the concentration of matrix. In addition we found that 3D-cultures enhanced neuronal differentiation and the survival rate of the cells compared to 2D-cultures.

Conclusions

Taken together, we have demonstrated a direct influence of the 3D-scaffold formation on the survival and neuronal differentiation of human neural progenitor cells. These findings emphasize the importance of optimizing 3D-scaffolds protocols prior toin vivoengraftment of stem and progenitor cells in the context of regenerative medicine.
APOE polymorphism is associated with lipid profile, but not with arterial stiffness in the general population
Authors: Alvim Rafael O , Freitas Silvia RS , Ferreira Noely E , Santos Paulo CJL , Cunha Roberto S , Mill José G , Krieger José E , Pereira Alexandre C
Published: November 2010

Background

Cardiovascular diseases (CVD) are the main cause of death and disability in developed countries. In most cases, the progress of CVD is influenced by environmental factors and multifactorial inheritance. The purpose of this study was to investigate the association between APOE genotypes, cardiovascular risk factors, and a non-invasive measure of arterial stiffness in the Brazilian population.

Methods

A total of 1493 urban Brazilian individuals were randomly selected from the general population of the Vitoria City Metropolitan area. Genetic analysis of the APOE polymorphism was conducted by PCR-RFLP and pulse wave velocity analyzed with a noninvasive automatic device.

Results

Age, gender, body mass index, triglycerides, creatinine, uric acid, blood glucose, blood pressure phenotypes were no different between ε2, ε3 and ε4 alleles. The ε4 allele was associated with higher total-cholesterol (p < 0.001), LDL-C (p < 0.001), total-cholesterol/HDL-C ratio (p < 0.001), LDL/HDL-C ratio (p < 0.001), lower HDL-C values (p < 0.001) and higher risk to obesity (OR = 1.358, 95% CI = 1.019-1.811) and hyperuricemia (OR = 1.748, 95% CI = 1.170-2.611). Nevertheless, pulse wave velocity (p = 0.66) measures were no different between genotypes. The significant association between APOE genotypes and lipid levels persisted after a 5-year follow-up interval, but no interaction between time and genotype was observed for lipids longitudinal behavior.

Conclusion

The ε4 allele of the APOE gene is associated with a worse lipid profile in the Brazilian urban population. In our relatively young sample, the observed effect of APOE genotype on lipid levels was not translated into significant effects in arterial wall stiffness.
Prognostic impact of clinical course-specific mRNA expression profiles in the serum of perioperative patients with esophageal cancer in the ICU: a case control study
Authors: Takahashi Shunsaku , Miura Norimasa , Harada Tomomi , Wang ZhongZhi , Wang Xinhui , Tsubokura Hideyuki , Oshima Yoshiaki , Hasegawa Junichi , Inagaki Yoshimi , Shiota Goshi
Published: November 2010

Background

We previously reported that measuring circulating serum mRNAs using quantitative one-step real-time RT-PCR was clinically useful for detecting malignancies and determining prognosis. The aim of our study was to find crucial serum mRNA biomarkers in esophageal cancer that would provide prognostic information for post-esophagectomy patients in the critical care setting.

Methods

We measured serum mRNA levels of 11 inflammatory-related genes in 27 post-esophagectomy patients admitted to the intensive care unit (ICU). We tracked these levels chronologically, perioperatively and postoperatively, until the two-week mark, investigating their clinical and prognostic significance as compared with clinical parameters. Furthermore, we investigated whether gene expression can accurately predict clinical outcome and prognosis.

Results

Circulating mRNAs in postoperative esophagectomy patients had gene-specific expression profiles that varied with the clinical phase of their treatment. Multivariate regression analysis showed that upregulation of IL-6, VWF and TGF-β1 mRNA in the intraoperative phase (p = 0.016, 0.0021 and 0.009) and NAMPT and MUC1 mRNA on postoperative day 3 (p < 0.01) were independent factors of mortality in the first year of follow-up. Duration of ventilator dependence (DVD) and ICU stay were independent factors of poor prognosis (p < 0.05). Therapeutic use of Sivelestat (Elaspol®, Ono Pharmaceutical Co., Ltd.) significantly correlated with MUC1 and NAMPT mRNA expression (p = 0.048 and 0.045). IL-6 mRNA correlated with hypercytokinemia and recovery from hypercytokinemia (sensitivity 80.9%) and was a significant biomarker in predicting the onset of severe inflammatory diseases.

Conclusion

Chronological tracking of postoperative mRNA levels of inflammatory-related genes in esophageal cancer patients may facilitate early institution of pharamacologic therapy, prediction of treatment response, and prognostication during ICU management in the perioperative period.
Absence of IFNγ expression induces neuronal degeneration in the spinal cord of adult mice
Authors: Victório Sheila CS , Havton Leif A , Oliveira Alexandre LR
Published: November 2010

Background

Interferon gamma (IFNγ) is a pro-inflammatory cytokine, which may be up-regulated after trauma to the peripheral or central nervous system. Such changes include reactive gliosis and synaptic plasticity that are considered important responses to the proper regenerative response after injury. Also, IFNγ is involved in the upregulation of the major histocompatibility complex class I (MHC class I), which has recently been shown to play an important role in the synaptic plasticity process following axotomy. There is also evidence that IFNγ may interfere in the differentiation and survival of neuronal cells. However, little is known about the effects of IFNγ absence on spinal cord neurons after injury.

Methods

We performed a unilateral sciatic nerve transection injury in C57BL/6J (wild type) and IFNγ-KO (mutant) mice and studied motoneuron morphology using light and electron microscopy. One week after the lesion, mice from both strains were sacrificed and had their lumbar spinal cords processed for histochemistry (n = 5 each group) and transmission electron microscopy (TEM, n = 5 each group). Spinal cord sections from non-lesioned animals were also used to investigate neuronal survival and the presence of apoptosis with TUNEL and immunohistochemistry.

Results

We find that presumed motoneurons in the lower lumbar ventral horn exhibited a smaller soma size in the IFNγ-KO series, regardless of nerve lesion. In plastic embedded sections stained with toluidine blue, the IFNγ-KO mice demonstrated a greater proportion of degenerating neurons in the ventral horn when compared to the control series (p < 0.05). Apoptotic death is suggested based on TUNEL and caspase 3 immunostaining. A sciatic nerve axotomy did not further aggravate the neuronal loss. The cellular changes were supported by electron microscopy, which demonstrated ventral horn neurons exhibiting intracellular vacuoles as well as degenerating nuclei and cytoplasm in the IFNγ-KO mice. Adjacent glial cells showed features suggestive of phagocytosis. Additional ultrastructural studies showed a decreased number of pre-synaptic terminals apposing to motoneurons in mutant mice. Nevertheless, no statistical difference regarding the input covering could be detected among the studied strains.

Conclusion

Altogether, these results suggest that IFNγ may be neuroprotective and its absence results in neuronal death, which is not further increased by peripheral axotomy.
Construction of Metabolically Biotinylated Adenovirus with Deleted Fiber Knob as Targeting Vector
Authors: Liu Yanzheng , Valadon Philippe , Schnitzer Jan E
Published: November 2010

Gene delivery vectors based on adenovirus, particularly human adenovirus serotype 5 (hAd5) have great potential for the treatment of variety of diseases. However, the tropism of hAd5 needs to be modified to achieve tissue- or cell- specific therapies for the successful application of this vector system to clinic. Here, we modified hAd5 tropism by replacing the fiber knob which contains the coxsackievirus B and adenovirus receptor (CAR)-binding sites with a biotin acceptor peptide, a truncated form of Propionibacterium shermanii 1.3 S transcarboxylase domain (PSTCD), to enable metabolically biotinylation of the virus. We demonstrate here that the new adenovirus no longer shows CAR-dependent cell uptake and transduction. When metabolically biotinylated and avidin-coated, it forms a nano-complex that can be retargeted to distinct cells using biotinylated antibodies. This vector may prove useful in the path towards achieving targeted gene delivery.
The spectral quality of light is a key driver of photosynthesis and photoadaptation in Stylophora pistillata colonies from different depths in the Red Sea
Authors: Mass T. , Kline D. I. , Roopin M. , Veal C. J. , Cohen S. , Iluz D. , Levy O.
Published: November 2010

Depth zonation on coral reefs is largely driven by the amount of downwelling, photosynthetically active radiation (PAR) that is absorbed by the symbiotic algae (zooxanthellae) of corals. The minimum light requirements of zooxanthellae are related to both the total intensity of downwelling PAR and the spectral quality of the light. Here we used Stylophora pistillata colonies collected from shallow (3 m) and deep (40 m) water; colonies were placed in a respirometer under both ambient PAR irradiance and a filter that only transmits blue light. We found that the colonies exhibited a clear difference in their photosynthetic rates when illuminated under PAR and filtered blue light, with higher photosynthetic performance when deep colonies were exposed to blue light compared with full-spectrum PAR for the same light intensity and duration. By contrast, colonies from shallow water showed the opposite trend, with higher photosynthetic performances under full-spectrum PAR than under filtered blue light. These findings are supported by the absorption spectra of corals, with deeper colonies absorbing higher energy wavelengths than the shallow colonies, with different spectral signatures. Our results indicate that S. pistillata colonies are chromatically adapted to their surrounding light environment, with photoacclimation probably occurring via an increase in photosynthetic pigments rather than algal density. The spectral properties of the downwelling light are clearly a crucial component of photoacclimation that should be considered in future transplantation and photoacclimation studies.
Chemo-accumulation without changes in membrane potential in the microstome form of the ciliate Tetrahymena vorax
Authors: Grønlien Heidi K. , Rønnevig Anna Kari , Hagen Bjarne , Sand Olav
Published: November 2010

The swimming behaviour of ciliates is mainly determined by membrane potential and transmembrane fluxes. In a chemical gradient, swimming ciliates may approach or move away from the source. Based on experiments on Paramecium, it is generally assumed that chemical attractants and repellents affect the swimming behaviour of ciliates by specific changes in the membrane potential. We have examined whether there is a causal relationship between membrane potential and chemo-accumulation in the microstome form of the polymorphic ciliate Tetrahymena vorax. Effects of chemo-attractants on the membrane potential of Tetrahymena have not been previously reported. Microstome T. vorax cells aggregated close to a point source of l-cysteine and the complex meat hydrolysate proteose peptone. Chemo-accumulated cells displayed a significantly higher turning frequency than control cells at a similar cell density. A concentration of 20 mmol l–1l-cysteine did not evoke any detectable change in the membrane potential whereas 1% proteose peptone depolarised the cells by ∼12 mV. This is contrary to the current model, which predicts agents that induce a moderate depolarisation to be repellents. A solution of 1% proteose peptone contains 21 mmol–1 Na+. A solution of 21 mmol–1 NaCl without organic compounds also caused ∼12 mV depolarisation but had no aggregating effect on the cells. Collectively, the electrophysiological and behavioural data indicate that chemo-accumulation in the microstome form of T. vorax is not governed obligatorily by the membrane potential. We thus suggest that the simple membrane potential model for chemokinesis in Paramecium may not be valid for T. vorax.
Characterization of mechanisms for Ca2+ and HCO3–/CO32– acquisition for shell formation in embryos of the freshwater common pond snail Lymnaea stagnalis
Authors: Ebanks Sue C. , O'Donnell Michael J. , Grosell Martin
Published: November 2010

The freshwater common pond snail Lymnaea stagnalis produces embryos that complete direct development, hatching as shell-bearing individuals within 10 days despite relatively low ambient calcium and carbonate availability. This development is impaired by removal of ambient total calcium but not by removal of bicarbonate and/or carbonate. In this study we utilized pharmacological agents to target possible acquisition pathways for both Ca2+ and accumulation of carbonate in post-metamorphic, shell-laying embryos. Using whole egg mass flux measurements and ion-specific microelectrode analytical techniques, we have demonstrated that carbonic anhydrase-catalyzed hydration of CO2 is central in the acquisition of both shell-forming ions because it provides the hydrogen ions for an electrogenic vacuolar-type H+-ATPase that fuels the uptake of Ca2+via voltage-dependent Ca2+ channels and possibly an electrogenic Ca2+/1H+ exchanger. Additionally, CO2 hydration provides an endogenous source of HCO –3. Thus, hydration of endogenous CO2 forms HCO –3 for calcification while hydrogen ions are excreted, contributing to continued Ca2+ uptake, as well as creating favorable alkaline internal conditions for calcification. The connections between Ca2+ and HCO –3 acquisition mechanisms that we describe here provide new insight into this efficient, embryonic calcification in freshwater.
Diel foraging behavior of gravid leatherback sea turtles in deep waters of the Caribbean Sea
Authors: Casey James , Garner Jeanne , Garner Steve , Williard Amanda Southwood
Published: November 2010

It is generally assumed that leatherback turtles (Dermochelys coriacea), like other species of sea turtle, do not feed while offshore from nesting beaches, and rely instead on fat reserves to fuel reproductive activities. Recent studies, however, provide evidence that leatherbacks may forage during the internesting interval while offshore in the Western Atlantic Ocean and Caribbean Sea. Bio-logging technology was used to investigate the foraging behavior of female leatherback turtles at St Croix, US Virgin Islands. Leatherback gastrointestinal tract temperatures (TGT) were analyzed for sudden fluctuations indicative of ingestions, and laboratory ingestion simulations were used to characterize temperature fluctuations associated with ingestion of prey versus seawater. Dive patterns associated with prey ingestion were characterized and the proportion of prey ingestion during the day (05:00–18:59 h) and night (19:00–04:59 h) were compared. A combined total of 111 prey ingestions for seven leatherback turtles were documented during the internesting interval. The number of prey ingestions ranged from six to 48 for individual turtles, and the majority (87.4%) of these events occurred during the daytime. Prey ingestions were most frequently associated with V-shaped dives, and the mean (±1 s.d.) maximum dive depth with prey ingestion ranged from 154±51 to 232±101 m for individual turtles. Although leatherbacks were found to opportunistically feed during the internesting interval, the low prey ingestion rates indicate that energy reserves acquired prior to the breeding season are critical for successful reproduction by leatherbacks from the St Croix, USVI nesting population.
Eyes with basic dorsal and specific ventral regions in the glacial Apollo, Parnassius glacialis (Papilionidae)
Authors: Awata Hiroko , Matsushita Atsuko , Wakakuwa Motohiro , Arikawa Kentaro
Published: November 2010

Recent studies on butterflies have indicated that their colour vision system is almost species specific. To address the question of how this remarkable diversity evolved, we investigated the eyes of the glacial Apollo, Parnassius glacialis, a living fossil species belonging to the family Papilionidae. We identified four opsins in the Parnassius eyes – an ultraviolet- (PgUV), a blue- (PgB), and two long wavelength (PgL2, PgL3)-absorbing types – and localized their mRNAs within the retina. We thus found ommatidial heterogeneity and a clear dorso-ventral regionalization of the eye. The dorsal region consists of three basic types of ommatidia that are similar to those found in other insects, indicating that this dorsal region retains the ancestral state. In the ventral region, we identified two novel phenomena: co-expression of the opsins of the UV- and B-absorbing type in a subset of photoreceptors, and subfunctionalization of long-wavelength receptors in the distal tier as a result of differential expression of the PgL2 and PgL3 mRNAs. Interestingly, butterflies from the closely related genus Papilio (Papilionidae) have at least three long-wavelength opsins, L1–L3. The present study indicates that the duplication of L2 and L3 occurred before the Papilio lineage diverged from the rest, whereas L1 was produced from L3 in the Papilio lineage.
Why Does the Economy Fall to Pieces after a Financial Crisis?
Authors: Hall Robert E
Published: November 2010

The worst financial crisis in the history of the United States and many other countries started in 1929. The Great Depression followed. The second-worst struck in the fall of 2008 and the Great Recession followed. Commentators have dwelt endlessly on the causes of these and other deep financial collapses. This article pursues modern answers to a different question: why does output and employment collapse after a financial crisis and remain at low levels for several or many years after the crisis. It focuses on events in the United States since 2008. Existing macroeconomic models account successfully for the immediate effects of a financial crisis on output and employment. I will lay out a simple macro model that captures the most important features of modern models and show that realistic increases in financial frictions that occurred in the crisis of late 2008 will generate declines in real GDP and employment of the magnitude that occurred. But this model cannot explain why GDP and employment failed to recover once the financial crisis subsided—the model implies a recovery as soon as financial frictions return to normal. At the end of the article, I will mention some ideas that are in play to explain the persistent adverse effects of temporary crises, but have yet to be incorporated into the mainstream model.
Natural Expectations and Macroeconomic Fluctuations
Authors: Fuster Andreas , Laibson David , Mendel Brock
Published: November 2010

A large body of empirical evidence suggests that beliefs systematically deviate from perfect rationality. Much of the evidence implies that economic agents tend to form forecasts that are excessively influenced by recent changes. We present a parsimonious quasi-rational model that we call natural expectations, which falls between rational expectations and (naïve) intuitive expectations. (Intuitive expectations are formed by running growth regressions with a limited number of right-hand-side variables, and this leads to excessively extrapolative beliefs in certain classes of environments). Natural expectations overstate the long-run persistence of economic shocks. In other words, agents with natural expectations turn out to form beliefs that don't sufficiently account for the fact that good times (or bad times) won't last forever. We embed natural expectations in a simple dynamic macroeconomic model and compare the simulated properties of the model to the available empirical evidence. The model's predictions match many patterns observed in macroeconomic and financial time series, such as high volatility of asset prices, predictable up-and-down cycles in equity returns, and a negative relationship between current consumption growth and future equity returns.
Manipulation Robustness of Collaborative Filtering
Authors: Van Roy Benjamin , Yan Xiang
Published: November 2010

A collaborative filtering system recommends to users products that similar users like. Collaborative filtering systems influence purchase decisions and hence have become targets of manipulation by unscrupulous vendors. We demonstrate that nearest neighbors algorithms, which are widely used in commercial systems, are highly susceptible to manipulation and introduce new collaborative filtering algorithms that are relatively robust.
Design and Analysis of Diagnostic Service Centers
Authors: Wang Xiaofang , Debo Laurens G. , Scheller-Wolf Alan , Smith Stephen F.
Published: November 2010

In the health-care domain, diagnostic service centers provide advice to patients over the phone about what the most appropriate course of action is based on their symptoms. Managers of such centers must strike a balance between accuracy of advice, callers' waiting time, and staffing costs by setting the appropriate capacity (staffing) and service depth. We model this problem as a multiple-server queueing system, with the servers performing a sequential testing process and the customers deciding whether or not to use the service, based on their expectation of accuracy and congestion. We find the dual concerns of accuracy and congestion lead to a counterintuitive impact of capacity: Increasing capacity might increase congestion. In addition, (i) patient population size is an important driver in management decisions, not only in staffing but also in accuracy of advice; (ii) increasing asymmetry in error costs may not increase asymmetry in the corresponding error rates; and (iii) the error costs for the two major stakeholders—the service manager and the patient—may impact the optimal staffing level in different ways. Finally, we highlight the relevance of our model and results to challenges in practice elicited during interviews with current clinical researchers and practitioners.
Energy, supramolecular chemistry, fullerenes, and the sky
Authors: Pérez Emilio M.
Published: November 2010

The search for cleaner and more abundant sources of energy is one of the major scientific challenges of the 21st century. Owing to its privileged position as the central science, chemistry is bound to play a leading role in this quest. Within the search for new materials for organic photovoltaics, some of the work we have carried out concerning the supra-molecular chemistry of electron donor and acceptor molecules is presented.
Charge-by-charge assemblies based on planar anion receptors
Authors: Maeda Hiromitsu , Haketa Yohei
Published: November 2010

This critical overview proposes a new concept, a charge-by-charge assembly, which consists of alternately stacked positively and negatively charged species, by introducing examples of planar anionic structures in the solid state. The preparation of planar organic anions is not easy; however, complexation of planar anion receptor molecules with inorganic anions is found to be an efficient strategy for constructing them. As suitable motifs, dipyrrolyldiketone boron complexes exhibit various receptor–anion complexes and charge-by-charge assemblies in the solid state. The concept discussed here can be applied to useful soft materials as well as crystals by modifying the anion receptors and cations.
Preparation, Characterization, and Evaluations of Polyurethane Elastomers Based on Polyether Glycol, Toluene Diisocyanate, and Extender Chain Reagents
Authors: Han H. Q. , Wei F. X. , Brown J.
Published: November 2010

In this study, we focus on the preparation, microstructures, and properties of polyurethane (PU) elastomers by using polyether glycol, toluene diisocyanate, and extender chain reagent. We find that the elastomers prepared by using extender chain reagent exhibit the most excellent mechanical properties. Furthermore, by an optimum synthetic route, hard segments can be formed uniformly in the soft segments, leading to the perfect micro-phase separation. We also find that the relative molecular weight of polyether glycol can affect the mechanical properties of the synthesized PU elastomers, i.e., the more relative molecular weight, the more soft segments, and the smaller tensile strength, rupture strength, and rigidity.
Non-invasive fibrosis assessment in chronic hepatitis C: aspartate-aminotransferase to platelet ratio index (APRI) and transient elastography (FibroScan)
Authors: Pár Alajos , Pár Gabriella
Published: November 2010

Bár a májbiopszia ma is „arany standard” a hepatológiai diagnosztikában, újabban a nem invazív próbák is egyre inkább előtérbe kerülnek a májfibrosis értékelésében. A szerzők az aszpartát-aminotranszferáz/thombocyta hányados (APRI) és a májtömöttség (elaszticitás) vizsgálatán alapuló tranziens elasztográfia szerepét tanulmányozták krónikus hepatitis C-vírus- (HCV-) infekcióban.Betegek és módszerek:Száztizenkilenc HCV-fertőzött beteg közül 75 szenvedett biopsziával igazolt krónikus C-hepatitisben, 24 HCV-cirrhosisban, 20 egyén tünetmentes, tartósan normális alanin-aminotranszferáz enzim értéket mutató HCV-hordozó volt, és 30 egészséges véradó szerepelt kontrollként. AWaiszerinti APRI-score kiszámítása az aszpartát-aminotranszferáz- és a thrombocytaszám-értékek alapján, a fibrosisra utaló májtömöttség (liver stiffness, LS) vizsgálata ultrahangalapú tranziens elasztográfiával, FibroScan alkalmazásával, míg a METAVIR fibrosisscore megállapítása májbiopszia révén történt.Eredmények:Krónikus C-hepatitisben mindkét fibrosismarker értékei szignifikánsan magasabbak voltak, mint a kontrollcsoportban, legmagasabb HCV-cirrhosisban. A tünetmentes HCV-hordozók adatai alig tértek el az egészségesekétől. Mindkét mutató értékei korreláltak a hisztológiai stádiumokkal. Az LS-vizsgálat érzékenyebb volt a fibrosis diagnosztizálásában, mint az APRI. A két fibrosismarker adatain alapuló szekvenciális algoritmus szerint a krónikus C-hepatitises betegek 47,8%-ában a szignifikáns (F≥2) fibrosis biopszia nélkül is feltételezhető.Következtetés:Az APRI-score és a tranziens elasztográfia, különösen kombinációban, hasznos nem invazív eljárás a fibrosis értékelésében krónikus HCV-infekcióban. Orv. Hetil., 2010,47,1951–1955.
Surgical strategy of colorectal liver metastases treatment depending on clinical and pathological response to neoadjuvant chemo- and target therapy
Authors: Jakab Ferenc
Published: November 2010

Napjainkban az előrehaladott colorectalis carcinoma mindennapos onkológiai kihívásként jelenik meg a kezelőorvos számára. Az utóbbi években bevezetett protokolloknak köszönhetően jelentős terápiás előrelépésnek lehetünk tanúi. A neoadjuváns kemoterápia biológiai válaszmódosítókkal történt kiegészítése nagymértékben növelte a terápiára adott klinikai választ a májmetasztázisos betegek körében. Az ezredfordulót követően egyre gyakrabban találkozunk a májáttétek teljes eltűnésének jelenségével. A májáttétek sebészetével foglalkozó irodalom egyértelmű és világos különbséget tesz a klinikai és patológiai válasz között, ugyanakkor a két válasz között lévő összefüggés pontos kritériumait is rögzítette. A colorectalis carcinoma májmetasztázisainak komplex kezelésében a teljes patológiai válasz jelenti a végső célt.Célok és módszerek:Jelen kutatás 2009. január 1.–2010 augusztus 31. közötti időszakban, 39 betegben vizsgálta a klinikai és patológiai választ. A májreszekciós műtétet neoadjuváns kemo- és targetterápia előzte meg.Eredmények:Teljes patológiai válasz két betegben (5,71%), major patológiai válasz (necrosis >50%) 12 betegben, minor patológiai válasz (necrosis <50%) 22 betegben alakult ki, míg 3 betegben egyáltalán nem volt necrosis.Következtetések:A colorectalis carcinoma májmetasztázisainak neoadjuváns és célzott terápiás kezelése során a patológiai válasz elérésére kell törekedni. Jelenleg a patológiai választ tartjuk a legfontosabb prognosztikus faktornak, amely az R0 reszekciót követő hosszú távú túlélést döntően és alapvetően határozza meg. Ellentmondásos a májmetasztázisok teljes eltűnésének megítélése, mivel műtéttechnikailag ez igen nehéz helyzet elé állítja az operatőrt. Ebben az értelemben az áttétek teljes eltűnése nemkívánatos mellékhatás, amely miatt a stratégia azt kívánja, hogy májmetasztázisos beteg ne legyen „túlkezelve”, amíg az áttét/áttétek teljesen eltűnnek, hanem a multidiszciplináris onkoteam hozza meg időben a döntést a májműtét indikációját illetően a még lokalizálható metasztázis/metasztázisok eltávolítására. Orv. Hetil., 2010,47,1956–1960.
Immediate Implants After Enucleation of an Odontogenic Keratocyst: An Early Return to Function
Authors: Isler Sabri C. , Demircan Sabit , Can Taylan , Cebi Zerrin , Baca Emrah
Published: November 2010

An odontogenic keratocyst is a unique cyst because of its locally aggressive behavior, high recurrence rate, and characteristic histologic appearance. In this article we present the case of a 22-year-old male patient with a large odontogenic keratocyst and describe his treatment with immediate dental implants.
Splinting Osseointegrated Implants and Natural Teeth in Partially Edentulous Patients: A Systematic Review of the Literature
Authors: Mamalis Anastasios , Markopoulou Kleopatra , Kaloumenos Konstatinos , Analitis Antonis
Published: November 2010

Dental implants in partially edentulous patients are a predictable therapeutic option. In patients with reduced bone volume, tooth-to-implant connected prostheses have been described as a treatment option. In this systematic review, the incidence of biologic and technical complications and the long-term survival rates of tooth-implant supported fixed partial dentures (FPDs) are analyzed. In cases where a natural tooth is connected with an implant to support a FPD, a rigid connection should be preferred.
Prevalence of central obesity in a large sample of adolescents from public schools in Recife, Brazil
Authors: Griz Luiz H. M. , Viégas Maíra , Barros Mauro , Griz Adriana L. , Freese Eduardo , Bandeira Francisco
Published: November 2010

OBJECTIVE: To determine the prevalence and association of central obesity (CO) and hypertension and its associations with alcohol intake, smoking and physical activity in adolescents. SUBJECTS AND METHODS: Cross sectional study in 1,824 students from 29 public schools in Recife. RESULTS: 89.6% were normal weight, 6.7% overweight and 3.7% obese; 77.2% were normotensive, 5.9% prehypertensive and 16.9% hypertensive; CO was 10.2% when the 90th percentile was used as cutoff and 25.2% when the 75th percentile was used. There was a higher likelihood of central obesity among students aged 18 to 20 years, smoking and alcohol intake. The probability of hypertension increases if the subject is male, has a waist circumference (WC) > 90, WC > 75 and does not practice physical activity. CONCLUSIONS: A high prevalence of CO and hypertension was found in adolescents. CO was more frequent in students aged 18 to 20 years, smokers and with alcohol intake and hypertension was associated with male, CO and no physical activity.
Os compromissos do médico: reflexões sobre a oração de Maimônides
Authors: Jorge Filho Isac
Published: November 2010

Ciência/Arte milenar, a Medicina envolve, pela sua natureza, compromissos firmes com princípios básicos da Bioética e que se resumem na busca da saúde e bem-estar das pessoas e comunidades em seu mais amplo sentido. Tais compromissos podem ser mais formais, como os de obediência aos Códigos de Deontologia e Ética; públicos, como os Juramentos; ou de consciência, que são as Orações. O modelo destes últimos é a Oração de Maimônides, apresentada neste artigo.
Gochnatia polymorpha (Less.) Cabrera (Asteraceae) changes in leaf structure due to differences in light and edaphic conditions
Authors: Rossatto Davi Rodrigo , Kolb Rosana Marta
Published: November 2010

Gochnatia polymorpha (Less.) Cabrera is a widespread Asteraceae species found in different physiognomies of cerrado (Neotropical savanna) and in forest formations of southeast Brazil. This study describes some leaf anatomy characteristics of this species and quantitatively evaluates them in relation to different environments, as well as under different light conditions. We found quantitative differences in all anatomical parameters analyzed. The results demonstrate that high leaf anatomy plasticity is an adaptive advantage that allows this species to occur in diverse cerrado conditions.
Nova espécie de Cybianthus Mart. (Myrsinaceae) do sudeste do Brasil
Authors: Jung-Mendaçolli Sigrid Luiza , Bernacci Luís Carlos , Freitas Maria de Fátima
Published: November 2010

Descrevemos e ilustramos uma nova espécie de Cybianthus (Myrsinaceae) do sudeste brasileiro: Cybianthus membranaceus Jung-Mend., Bernacci & M.F.Freitas, que é próxima de Cybianthus cuneifolius Mart., mas pode ser facilmente distinta pelas inflorescências muito mais curtas que a lâmina foliar e folhas obovais ou oblanceoladas, tenuemente membranáceas, com ápices obtuso-cuspidados, concentradas na porção distal dos ramos.
Comparative thallus anatomy of two Parmotrema (Parmeliaceae, lichenized Ascomycetes) with reticulate maculae
Authors: Barbosa Suzana Bissacot , Marcelli Marcelo Pinto
Published: November 2010

Using conventional techniques for structural studies under conventional microscopy, polarizing light microscopy and scanning electron microscopy this work describes and compares the thallus anatomy of two Parmotrema species with reticulate maculae, previously included in the genus Rimelia: Parmotrema cetratum (Ach.) Hale and P. clavuliferum (Räsänen) Streimann. The data showed that the species are anatomically similar, including the presence of epicortex, the upper cortex anatomy and the characteristics of rhizines and ciliae. In the medulla of the two species there are star-shaped clusters of hyphae associated with the presence of salazinic acid. This study showed that the anatomical characteristics are constant for the Parmotrema group studied.