bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adaptation of calcium absorption during treatment of nutritional rickets in Nigerian children
Authors: Oramasionwu Gloria E. , Thacher Tom D. , Pam Sunday D. , Pettifor John M. , Abrams Steven A. 
Published: January 2008

Nutritional rickets in Nigerian children has been effectively treated with Ca supplementation. High values of Ca absorption efficiency have been observed in untreated children, but whether Ca absorption efficiency changes during treatment with Ca is unknown. Our objective in conducting this study was to identify the effect of Ca therapy on Ca absorptive efficiency in children with primary Ca-deficient nutritional rickets. Twelve children with radiographically active rickets, 2 to 14 years of age (median 39 months) participated in the study. We assessed dietary Ca intake via dietary recalls, and measured biochemical markers of Ca and vitamin D homeostasis. Fractional Ca absorption was measured using a dual tracer stable isotope method, before and after 2 weeks of treatment with 15·0 mmol elemental Ca daily. Ten children had adequate urine collection for inclusion in the analysis. Usual dietary Ca intake was 4·2 (sd 1·0) mmol/d. The median Ca absorption prior to treatment was 72 % (range 52–97 %) and decreased significantly to 57 % (31–84 %) (P = 0·004) after 2 weeks of supplementation. We conclude that Nigerian children with rickets adapt to Ca supplementation with a small decrease in Ca absorptive capacity, but retain very high absorptive levels during supplementation. Overall Ca absorption efficiency was comparable with that identified in other populations with low Ca intakes. These data demonstrate that although absorptive capacity is regulated by supplementation, recovery from rickets likely occurs through efficient use of both dietary and supplemental Ca.
Key issues for attention from ecological economists
Authors: EHRLICH PAUL R. 
Published: January 2008

ABSTRACTThis paper gives an ecologist's overview of the deteriorating environmental situation. It then describes areas where the activities of ecological economists seem appropriate (e.g., ecosystem service valuation, trade) and others requiring more attention (e.g., definitions of utility, social discounting, preserving population diversity, global toxification, the epidemiological environment, overpopulation, overconsumption, the economic impacts of nuclear explosions, and the equilibration of opportunity costs when attempting to solve global dilemmas). A general problem is the failure of ecological economists adequately to communicate their results and concerns to the general public and to decision makers. In view of the demonstrable failure of traditional economics to focus its attention on what will be the central issues of the twenty-first century, it is clear that ecological economics is in a position to become the central subdiscipline of economics. In order to do so, it is important for ecological economists to always keep the ‘big picture’ in view.
Query evaluation and optimization in the semantic web
Authors: RUCKHAUS EDNA , RUIZ EDUARDO , VIDAL MARÍA-ESTHER 
Published: January 2008

AbstractWe address the problem of answering Web ontology queries efficiently. An ontology is formalized as adeductive ontology base(DOB), a deductive database that comprises the ontology's inference axioms and facts. A cost-based query optimization technique for DOB is presented. A hybrid cost model is proposed to estimate the cost and cardinality of basic and inferred facts. Cardinality and cost of inferred facts are estimated using an adaptive sampling technique, while techniques of traditional relational cost models are used for estimating the cost of basic facts and conjunctive ontology queries. Finally, we implement a dynamic-programming optimization algorithm to identify query evaluation plans that minimize the number of intermediate inferred facts. We modeled a subset of the Web ontology language Lite as a DOB and performed an experimental study to analyze the predictive capacity of our cost model and the benefits of the query optimization technique. Our study has been conducted over synthetic and real-world Web ontology language ontologies and shows that the techniques are accurate and improve query performance.
Deciphering the β‐adrenergic response in human embryonic stem cell‐derived‐cardiac myocytes: closer to clinical use?
Authors: Catalucci D , Bang M L , Condorelli G 
Published: January 2008

Human embryonic stem cells (hESCs) are a pluripotent cell type considered to have high potential for the treatment of cardiovascular disease by cell replacement therapies. Several groups have shown that hESCs can be differentiated in vitro into cardiac myocytes, which may be used to facilitate tissue regeneration by injection directly into damaged myocardium. However, several hurdles still need to be overcome before these cells can be used in clinical trials. In particular, because transplanted hESC‐cardiac myocytes should integrate fully within the damaged heart, these cells must be functionally compatible with the host myocardium. To assess this aspect of hESC‐cardiac myocytes, Brito‐Martins et al. (2008) in this issue of the BJP, describe the responses of hESC‐cardiac myocytes to β‐adrenoceptor stimulation, compared to those of myocytes from adult human hearts. Data obtained using specific β‐adrenoceptor agonists showed good compatibility of hESC‐cardiac myocytes with adult human myocardium in terms of β‐adrenoceptor response. British Journal of Pharmacology (2008) 153, 625–626; doi:10.1038/sj.bjp.0707633; published online 14 January 2008
ATL‐1, an analogue of aspirin‐triggered lipoxin A4, is a potent inhibitor of several steps in angiogenesis induced by vascular endothelial growth factor
Authors: Cezar‐de‐Mello P F T , Vieira A M , Nascimento‐Silva V , Villela C G , Barja‐Fidalgo C , Fierro I M 
Published: January 2008

Background and purpose:Vascular endothelial growth factor (VEGF) is the most important proangiogenic protein. We have demonstrated that ATL‐1, a synthetic analogue of aspirin‐triggered lipoxin A4, inhibits VEGF‐induced endothelial cell (EC) migration. In the present study, we investigated the effects of ATL‐1 in several other actions stimulated by VEGF.Methods:Human umbilical vein ECs were treated with ATL‐1 for 30 min before stimulation with VEGF. Cell proliferation was measured by thymidine incorporation. Adherent cells were determined by fluorescence intensity using a Multilabel counter. Expression and activity of matrix metalloproteinases (MMP) were analysed by western blot and zymography.Key results:ATL‐1 inhibited EC adhesion to fibronectin via interaction with its specific receptor. Furthermore, VEGF‐induced MMP‐9 activity and expression were reduced by pretreatment with ATL‐1. Because the transcription factor NF‐κB has been implicated in VEGF‐mediated MMP expression and EC proliferation, we postulated that ATL‐1 might modulate the NF‐κB pathway and, indeed, ATL‐1 inhibited NF‐κB nuclear translocation. Pretreatment of EC with ATL‐1 strongly decreased VEGF‐dependent phosphorylation of phosphainositide 3‐kinase (PI3‐K) and extracellular signal‐regulated kinase‐2 (ERK‐2), two signalling kinases involved in EC proliferation. Inhibition of VEGF‐induced EC proliferation by ATL‐1 was antagonized by sodium orthovanadate, suggesting that this inhibitory activity was mediated by a protein tyrosine phosphatase. This was confirmed by showing that ATL‐1 inhibition of VEGF receptor‐2 (VEGFR‐2) phosphorylation correlates with SHP‐1 association with VEGFR‐2.Conclusions and implications:The synthetic 15‐epi‐lipoxin analogue, ATL‐1, is a highly potent molecule exerting its effects on multiple steps of the VEGF‐induced angiogenesis.British Journal of Pharmacology (2008) 153, 956–965; doi:10.1038/sj.bjp.0707650; published online 14 January 2008
The utility of biomarker discovery approaches for the detection of disease mechanisms in psychiatric disorders
Authors: Schwarz E , Bahn S 
Published: January 2008

Schizophrenia remains an elusive multifaceted disorder with all evidence of its onset and aetiology pointing to a complex interplay of genetic, nutritional, environmental and developmental factors. Although several molecular and structural abnormalities have been reported for schizophrenia, no diagnostic test or other application of clinical use has yet emerged from this research. The heterogeneity of schizophrenia symptoms and its similarity to other psychiatric disorders, the accessibility of appropriate samples and the complexity of molecular alterations have greatly slowed down research. Biomarker discovery approaches should ultimately facilitate objective diagnosis, allow the identification of at‐risk individuals, predict treatment success and revolutionize drug‐discovery approaches. For psychiatric disorders, large sample numbers are necessary if disease‐intrinsic alterations are to be detected in an environment of high biological variability. Only recent technological advances facilitate the profiling of proteins and metabolites of large sample numbers. These approaches promise to provide interesting insights into disease mechanisms, as they enable capturing the dynamic nature of disease‐related alterations. By means of parallel profiling using a multi‐omics approach, we aim to disentangle the complex nature of schizophrenia's aetiology. Here, we will outline how this system‐based analysis approach can contribute to the discovery of disease mechanisms in schizophrenia and in turn other psychiatric disorders.British Journal of Pharmacology (2008) 153, S133–S136; doi:10.1038/sj.bjp.0707658; published online 14 January 2008
Effect of methylglyoxal modification on stress-induced aggregation of client proteins and their chaperoning by human αA-crystallin
Authors: Biswas Ashis , Wang Benlian , Miyagi Masaru , Nagaraj Ram H. 
Published: January 2008

α-Crystallin prevents protein aggregation under various stress conditions through its chaperone-like properties. Previously, we demonstrated that MGO (methylglyoxal) modification of αA-crystallin enhances its chaperone function and thus may affect transparency of the lens. During aging of the lens, not only αA-crystallin, but its client proteins are also likely to be modified by MGO. We have investigated the role of MGO modification of four model client proteins (insulin, α-lactalbumin, alcohol dehydrogenase and γ-crystallin) in their aggregation and structure and the ability of human αA-crystallin to chaperone them. We found that MGO modification (10–1000 μM) decreased the chemical aggregation of insulin and α-lactalbumin and thermal aggregation of alcohol dehydrogenase and γ-crystallin. Surface hydrophobicity in MGO-modified proteins decreased slightly relative to unmodified proteins. HPLC and MS analyses revealed argpyrimidine and hydroimidazolone in MGO-modified client proteins. The degree of chaperoning by αA-crystallin towards MGO-modified and unmodified client proteins was similar. Co-modification of client proteins and αA-crystallin by MGO completely inhibited stress-induced aggregation of client proteins. Our results indicate that minor modifications of client proteins and αA-crystallin by MGO might prevent protein aggregation and thus help maintain transparency of the aging lens.
Hepatic selenoprotein P (SePP) expression restores selenium transport and prevents infertility and motor-incoordination in Sepp-knockout mice
Authors: Renko Kostja , Werner Margarethe , Renner-Müller Ingrid , Cooper Trevor G. , Yeung Ching Hei , Hollenbach Birgit , Scharpf Marcus , Köhrle Josef , Schomburg Lutz , Schweizer Ulrich 
Published: January 2008

SePP (selenoprotein P) is central for selenium transport and distribution. Targeted inactivation of the Sepp gene in mice leads to reduced selenium content in plasma, kidney, testis and brain. Accordingly, activities of selenoenzymes are reduced in Sepp−/− organs. Male Sepp−/− mice are infertile. Unlike selenium deficiency, Sepp deficiency leads to neurological impairment with ataxia and seizures. Hepatocyte-specific inactivation of selenoprotein biosynthesis reduces plasma and kidney selenium levels similarly to Sepp−/− mice, but does not result in neurological impairment, suggesting a physiological role of locally expressed SePP in the brain. In an attempt to define the role of liver-derived circulating SePP in contrast with locally expressed SePP, we generated Sepp−/− mice with transgenic expression of human SePP under control of a hepatocyte-specific transthyretin promoter. Secreted human SePP was immunologically detectable in serum from SEPP1-transgenic mice. Selenium content and selenoenzyme activities in serum, kidney, testis and brain of Sepp−/−;SEPP1 (SEPP1-transgenic Sepp−/−) mice were increased compared with Sepp−/− controls. When a selenium-adequate diet (0.16-0.2 mg/kg of body weight) was fed to the mice, liver-specific expression of SEPP1 rescued the neurological defects of Sepp−/− mice and rendered Sepp−/− males fertile. When fed on a low-selenium diet (0.06 mg/kg of body weight), Sepp−/−;SEPP1 mice survived 4 weeks longer than Sepp−/− mice, but ultimately developed the neurodegenerative phenotype. These results indicate that plasma SePP derived from hepatocytes is the main transport form of selenium supporting the kidney, testis and brain. Nevertheless, local Sepp expression is required to maintain selenium content in selenium-privileged tissues such as brain and testis during dietary selenium restriction.
Prevalence and predictors of cardiac hypertrophy and dysfunction in patients with Type 2 diabetes
Authors: Srivastava Piyush M. , Calafiore Paul , Macisaac Richard J. , Patel Sheila K. , Thomas Merlin C. , Jerums George , Burrell Louise M. 
Published: January 2008

The aim of the present study was to determine the prevalence and predictors of an abnormal echocardiogram in patients with Type 2 diabetes. Cardiac function and structure were rigorously assessed by comprehensive transthoracic echocardiographic techniques in 229 patients with Type 2 diabetes. Cardiovascular risk factors and diabetic complications were assessed, and predictors of an abnormal echocardiogram were identified using multivariate logistic regression analysis. An abnormal echocardiogram was present in 166 patients (72%). LVH (left ventricular hypertrophy) occurred in 116 patients (51%), and cardiac dysfunction was found in 146 patients (64%), of whom 109 had diastolic dysfunction alone and 37 had systolic±diastolic dysfunction. Independent predictors of an abnormal echocardiogram were obesity, age, the number of antihypertensive drugs used (all P&lt;0.001) and creatinine clearance (P&lt;0.05). The risk of an abnormal echocardiogram increased by 9% for each year over 50 years of age {OR (odds ratio), 1.09 [95% CI (confidence interval), 1.04–1.15]}, 3-fold if obesity was present [BMI (body mass index) &gt;30; OR, 4.2 (95% CI, 1.9–9.0)] and by 80% for each antihypertensive agent used [OR, 1.8 (95% CI, 1.3–2.4) per agent]. In conclusion, an abnormal cardiac echocardiogram is common in patients with Type 2 diabetes. Importantly, although cardiac abnormalities can be predicted by traditional risk factors, such as age, obesity and renal function, the absence of micro- or macro-vascular complications does not predict a normal echocardiogram. We suggest that an echocardiogram identifies those with Type 2 diabetes at increased cardiovascular risk due to occult LVH and diastolic dysfunction, and this information may lead to more aggressive management of known risk factors in the clinic.
Control of stem nematode (Ditylenchus dipsaci) in narcissus and tulip by organophosphate and organocarbamate pesticides
Authors: DAMADZADEH M. , HAGUE N. G. M. 
Published: January 2008

SUMMARYCarbofuran, phoxim and thiofanox dips and aldicarb, carbofuran, phenamiphos and thiofanox granular applications were compared with a thionazin dip in pot experiments in a glasshouse to control stem nematode (Ditylenchus dipsaci (Kühn) Filipjev) in narcissus and tulip bulbs. Carbofuran and phoxim controlled stem nematode as effectively as thionazin. Treatment of bulbs with thionazin, carbofuran or phoxim prevented stem nematodes laying eggs in the bulbs. Phoxim has the advantage of low mammalian toxicity.
UVB Monochromatic Action Spectrum for the Inhibition of Photosynthetic Oxygen Production in the Green Alga Dunaliella salina
Authors: Ghetti Francesco , Fuoco Silvana , Checcucci Giovanni 
Published: January 2008

ABSTRACTThe effect of monochromatic UVB (280–315 nm) irradiation on the photosynthetic activity of the marine green alga Dunaliella salina was investigated by monitoring the rate of oxygen exchange. Samples were irradiated with narrow bands centered at different UV wavelengths (281, 290, 300, 310 and 322 nm). In a first set of experiments the samples were preirradiated keeping constant the irradiance and varying exposure time. By increasing UVB fluence, a wavelength‐dependent decrease in the rate of oxygen production was observed. In a second set of experiments oxygen exchange was monitored simultaneously to UVB irradiation. The decline in the rate of oxygen production was sharper at short wavelengths and faster with increasing UVB photon flux density. The photon fluence action spectra derived from the two sets of experiments are in good agreement and indicate a decrease in the UVB‐inhibiting effectiveness of two orders of magnitude from about 0.2 (mmol m‐2)‐1 at 281 nm to about 0.003 (mmol m‐2)‐1 at 322 nm. The photon flux density action spectrum derived from the second set of experiments indicates a smoother decrease from about 0.2 (pmol s‐l m‐2)‐1 at 281 nm to about 0.05 (pmol s‐l m‐z)‐l at 310 nm.
Ultraviolet‐A‐Dependent Inhibition of Cytoplasmic Aconitase Activity of Iron Regulatory Protein‐1 in NCTC 2544 Keratinocytes
Authors: Giordani Anne , Morlière Patrice , Djavaheri‐Mergny Mojgan , Santus René 
Published: January 2008

ABSTRACTThe aconitase activity of the cytoplasmic iron regulatory protein‐1 of NCTC 2544 keratinocytes is effectively inhibited by physiological doses of UVA. The time course of the photoinactivation is biphasic. A fast step is first observed corresponding to about 50% inactivation after exposure to 5 J/cm2of UVA followed by a much slower photoinactivation at higher doses. The water‐soluble antioxidant N‐acetylcysteine only partially inhibits the pho‐toinduced inactivation of the cytoplasmic aconitase function, whereas the lipophilic vitamin E, the iron chelator, desferrioxamine and the superoxide dismutase inhibitor, diethyldithiocarbamate do not protect at all. As a consequence, reactive oxygen species such as O2‐, H2O2 and lipid peroxides and hydroperoxides seem to play a rather minor role in the inactivation induced by the UVA pho‐tooxidative stress although an oxidative stress produced by O2‐ H2O2 is known to inhibit reversibly and effectively cytoplasmic aconitase activity in mammalian cells.
UVB‐lnduced DNA Damage and Its Photorepair in Nuclei and Chloroplasts of Spinacia oleracea L.
Authors: Hada M. , Hashimoto T. , Nikaido O. , Shin M. 
Published: January 2008

ABSTRACTUltraviolet‐B‐induced lesions and their photorepair in nuclear and chloroplast DNA of spinach (Spinacia oleracea L.) leaves were examined with two photoproducts, cyclobutane pyrimidine dimers (CPD) and pyrimidine (6‐4) pyrimidinone photoproducts (6‐4PP). These photoproducts were induced both in nuclear and chloroplast DNA by UVB irradiation and could be detected by enzyme‐linked immunosorbent assay using their respective monoclonal antibodies. Formation of CPD was greater in nuclear DNA than in chloroplast DNA (about 10 to 7), whereas 6‐4PP formation was comparable in both DNA. On subsequent exposure of leaves to blue/UVA after UVB irradiation, photorepair of CPD and 6‐4PP occurred in nuclear DNA but not in chloroplast DNA. When isolated chloroplasts were irradiated with UVB, CPD was also induced in their DNA. But photorepair of CPD did not occur in them by subsequent exposure to blue/UVA, suggesting that no photorepair system operates in chloroplasts.
A Study of the Uptake of Toluidine Blue O by Porphyromonas gingivalis and the Mechanism of Lethal Photosensitization
Authors: Bhatti Manpreet , MacRobert Alexander , Meghji Sajeda , Henderson Brian , Wilson Michael 
Published: January 2008

ABSTRACTThe purpose of the study was to determine the distribution of the photosensitizer toluidine blue O (TBO) within Porphyromonas gingivalis and the possible mechanism(s) involved in the lethal photosensitization of this organism. The distribution of TBO was determined by incubating P. gingivalis with tritiated TBO (3H‐TBO) and fractionating the cells into outer membrane (OM), plasma membrane (PM), cytoplasmic proteins, other cytoplasmic constituents and DNA. The percentage of TBO in each of the fractions was found to be, 86.7, 5.4, 1.9, 5.7 and 0.3%, respectively. The involvement of cytotoxic species in the lethal photosensitization induced by light from a helium‐neon (HeNe) laser and TBO was investigated by using deuterium oxide (D2O), which prolongs the lifetime of singlet oxygen, and the free radical and singlet oxygen scavenger L‐tryptophan. There were 9.0 log10 and 2 log10 reductions in the presence of D2O and H2O (saline solutions), respectively, at a light dose of 0.44 J (energy density = 0.22 J/cm2), suggesting the involvement of singlet oxygen. Decreased kills were attained in the presence of increasing concentrations of L‐tryptophan. The effect of lethal photosensitization on whole cell proteins was determined by measuring tryptophan fluorescence, which decreased by 30% using 4.3 J (energy density = 4.3 J/ cm2) of light. Effects on the OM and PM proteins were determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. There was evidence of change in the molecular masses of several PM proteins and OM proteins compared to controls. There was evidence of damage to the DNA obtained from irradiated cells. Scanning electron microscopic studies showed that there was coaggre‐gation of P. gingivalis cells when sensitized and then exposed to laser light. These results suggest that lethal photosensitization of P. gingivalis may involve changes in OM and/or PM proteins and DNA damage mediated by singlet oxygen.
Treatment of Malignant Melanoma by High‐Peak‐Power 1064 nm Irradiation Followed by Photodynamic Therapy
Authors: Busetti Alessandra , Soncin Marina , Jori Giulio , Kenney Malcolm E. , Rodgers Michael A. J. 
Published: January 2008

ABSTRACTIrradiation of B16 pigmented melanoma subcutaneously transplanted in C57 mice with a single 650 mj pulse (10 ns) of 1064 nm light from a Q‐switched Nd: YAG laser caused instantaneous bleaching of the pigmented tissue. Visual and histological examination of the resulting gray‐colored tumor revealed the breakdown of melanosomes with no detectable alteration of the normal and tumor‐overlying skin. Histological examination of the irradiated tumor showed some degree of vascular damage; the depth of the photodamage was not affected by the successive delivery of three consecutive light pulses. The bleached tumor grew at a modestly slower rate but the high‐peak‐power (HPP) laser treatment did not affect the tumor concentration of a photodynamic sensitizer Si(IV)‐naphthalocyanine (isoBO‐SiNc) intravenously injected 24 h before Nd : YAG irradiation. Treatment of the B16 pigmented melanoma by photodynamic therapy (PDT: 1 mg/kg isoBO‐SiNc, 300 mW/cm2, 520 J/cm2) from a 774 nm diode laser immediately after the 1064 nm irradiation resulted in a 16 day delay of tumor regrowth, which was markedly longer than the delay (ca 6 days) obtained after PDT under identical conditions without the preirradia‐tion. Thus, pretreatment of pigmented tumors with HPP 1064 nm light appears to enhance their susceptibility to conventional PDT. The tumor response was further enhanced by repeating the combined HPP/PDT treatment at an interval of 10 days (regrowth delay: 27 days), as well as by applying hyperthermia immediately after HPP/PDT (regrowth delay: ca 34 days).