bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetic and Thermodynamic Investigation on Ascorbate Oxidase Activity and Stability of a Cucurbita maxima Extract
Authors: Porto Tatiana S. , Porto Camila S. , Cavalcanti Maria T. H. , Filho José L. Lima , Perego Patrizia , Porto Ana L. F. , Converti Attilio , Pessoa Adalberto 
Published: November 2006

AbstractThe kinetic and thermodynamic properties of ascorbate oxidase (AO) activity and stability of a Cucurbita maxima extract were investigated. Activity tests performed at 25 °C using initial ascorbic acid concentration in the range 50–750 μM allowed estimating the Michaelis constant for this substrate (Km = 126 μM) and the maximum initial rate of ascorbic acid oxidation (A0,max = 1.57 mM min−1). The main thermodynamic parameters of the enzyme reaction (ΔH* = 10.3 kJ mol−1; ΔG* = 87.2 kJ mol−1; ΔS* = –258 J mol−1 K−1) were estimated through activity tests performed at 25–48 °C. Within such a temperature range, no decrease in the initial reaction rate was detected. The long‐term thermostability of the raw extract was then investigated by means of residual activity tests carried out at 10–70 °C, which allowed estimating the thermodynamic parameters of the irreversible enzyme inactivation as well (ΔH*D = 51.7 kJ mol−1; ΔG*D = 103 kJ mol−1; ΔS*D = –160 J mol−1 K−1). Taking into account the specific rate of AO inactivation determined at different temperatures, we also estimated the enzyme half‐life (1047 min at 10 °C and 21.2 min at 70 °C) and predicted the integral activity of a continuous system using this enzyme preparation. This work should be considered as a preliminary attempt to characterize the AO activity of a C. maxima extract before its concentration by liquid‐liquid extraction techniques.
Trypanothione-dependent glyoxalase I in Trypanosoma cruzi
Authors: Greig Neil , Wyllie Susan , Vickers Tim J. , Fairlamb Alan H. 
Published: November 2006

The glyoxalase system, comprizing glyoxalase I and glyoxalase II, is a ubiquitous pathway that detoxifies highly reactive aldehydes, such as methylglyoxal, using glutathione as a cofactor. Recent studies of Leishmania major glyoxalase I and Trypanosoma brucei glyoxalase II have revealed a unique dependence upon the trypanosomatid thiol trypanothione as a cofactor. This difference suggests that the trypanothione-dependent glyoxalase system may be an attractive target for rational drug design against the trypanosomatid parasites. Here we describe the cloning, expression and kinetic characterization of glyoxalase I from Trypanosoma cruzi. Like L. major glyoxalase I, recombinant T. cruzi glyoxalase I showed a preference for nickel as its metal cofactor. In contrast with the L. major enzyme, T. cruzi glyoxalase I was far less fast-idious in its choice of metal cofactor efficiently utilizing cobalt, manganese and zinc. T. cruzi glyoxalase I isomerized hemithio-acetal adducts of trypanothione more than 2400 times more efficiently than glutathione adducts, with the methylglyoxal adducts 2–3-fold better substrates than the equivalent phenylglyoxal adducts. However, glutathionylspermidine hemithioacetal adducts were most efficiently isomerized and the glutathionylspermidine-based inhibitor S-4-bromobenzylglutathionylspermidine was found to be a potent linear competitive inhibitor of the T. cruzi enzyme with a Ki of 5.4±0.6 μM. Prediction algorithms, combined with subcellular fractionation, suggest that T. cruzi glyoxalase I localizes not only to the cytosol but also the mitochondria of T. cruzi epimastigotes. The contrasting substrate specificities of human and trypanosomatid glyoxalase enzymes, confirmed in the present study, suggest that the glyoxalase system may be an attractive target for anti-trypanosomal chemotherapy.
ArabidopsisSAMT1 Defines a Plastid Transporter Regulating Plastid Biogenesis and Plant Development
Authors: Bouvier Florence , Linka Nicole , Isner Jean-Charles , Mutterer Jérôme , Weber Andreas P.M. , Camara Bilal 
Published: November 2006

AbstractS-Adenosylmethionine (SAM) is formed exclusively in the cytosol but plays a major role in plastids; SAM can either act as a methyl donor for the biogenesis of small molecules such as prenyllipids and macromolecules or as a regulator of the synthesis of aspartate-derived amino acids. Because the biosynthesis of SAM is restricted to the cytosol, plastids require a SAM importer. However, this transporter has not yet been identified. Here, we report the molecular and functional characterization of an Arabidopsis thaliana gene designated SAM TRANSPORTER1 (SAMT1), which encodes a plastid metabolite transporter required for the import of SAM from the cytosol. Recombinant SAMT1 produced in yeast cells, when reconstituted into liposomes, mediated the counter-exchange of SAM with SAM and with S-adenosylhomocysteine, the by-product and inhibitor of transmethylation reactions using SAM. Insertional mutation in SAMT1 and virus-induced gene silencing of SAMT1 in Nicotiana benthamiana caused severe growth retardation in mutant plants. Impaired function of SAMT1 led to decreased accumulation of prenyllipids and mainly affected the chlorophyll pathway. Biochemical analysis suggests that the latter effect represents one prominent example of the multiple events triggered by undermethylation, when there is decreased SAM flux into plastids.
Comparative phylogeography of two North American ‘glacial relict’ crustaceans
Authors: DOOH R. T. , ADAMOWICZ S. J. , HEBERT P. D. N. 
Published: November 2006

AbstractThe Pleistocene glaciations represent the most recent and dramatic series of habitat changes since the Cretaceous. The impact of these events was particularly acute for aquatic taxa with poor powers of dispersal, but few organisms have evolutionary histories more intimately entwined with the advance and retreat of ice than the ‘glacial relicts’. In this study, we used a mitochondrial gene, cytochrome c oxidase subunit I (COI), to examine and compare the phylogeographical structure of two glacial relict crustaceans (Limnocalanus macrurus and members of the Mysis relicta species group) across North America. In both cases, we found a sharp phylogenetic division between populations from inland lakes formed during glacial retreat, and arctic lakes isolated from polar seas via isostatic rebound. However, the depth of this phylogenetic partition varied between taxa. In L. macrurus, nucleotide sequence divergence of 2.2% between these zones is consistent with its current status as a single morphologically variable species, but in Mysis the split occurred among recently described, morphologically conserved species, at a divergence of 8.2%. The disparity in the depth of divergence indicates a history of recurrent freshwater invasions from the arctic seas, in concordance with previous studies of Eurasian glacial relicts. However, we suggest further consideration of a largely overlooked explanation that could account for some of the discrepancies between molecular divergences and glaciation events. Many cladogenetic events could have occurred in arctic seas prior to the transition to inland waters, a possibility supported both by the complex physical and ionic history of arctic seas and by high marine and estuarine lineage diversity in the north.
Effective gene dispersal and female reproductive success in Mediterranean maritime pine (Pinus pinaster Aiton)
Authors: GONZÁLEZ‐MARTÍNEZ SANTIAGO C. , BURCZYK JAROSLAW , NATHAN RAN , NANOS NIKOS , GIL LUIS , ALÍA RICARDO 
Published: November 2006

AbstractUnderstanding population‐scale processes that affect allele frequency changes across generations is a long‐standing interest in genetic, ecological and evolutionary research. In particular, individual differences in female reproductive success and the spatial scale of gene flow considerably affect evolutionary change and patterns of local selection. In this study, a recently developed maximum‐likelihood (ML) method based on established offspring, the Seedling Neighbourhood Model, was applied and exponentially shaped dispersal kernels were fitted to both genetic and ecological data in a widespread Mediterranean pine, Pinus pinaster Aiton. The distribution of female reproductive success in P. pinaster was very skewed (about 10% of trees mothered 50% of offspring) and significant positive female selection gradients for diameter (γ = 0.7293) and cone crop (γ = 0.4524) were found. The selective advantage of offspring mothered by bigger trees could be due to better‐quality seeds. These seeds may show more resilience to severe summer droughts and microsite variation related to water and nutrient availability. Both approaches, ecological and of parentage, consistently showed a long‐distance dispersal component in saplings that was not found in dispersal kernels based on seed shadows, highlighting the importance of Janzen‐Connell effects and microenvironmental variation for survival at early stages of establishment in this Mediterranean key forest tree.
Gastrointestinal stromal tumors of the stomach: Endosonographic differentiation in relation to histological risk
Authors: Jeon Seong Woo , Park Young Dae , Chung Yun Jin , Cho Chang Min , Tak Won Young , Kweon Young Oh , Kim Sung Kook , Choi Yong Hwan 
Published: November 2006

AbstractBackground and Aim:  The aim of this study was to determine the endosonographic characteristics of gastrointestinal stromal tumors (GISTs) of the stomach according to histological risk classification.Methods:  Twenty‐four cases of histologically proven c‐kit positive GISTs were divided into three groups according to histological risk: low risk (n = 14), intermediate risk (n = 7) and high risk (n = 3). Endoscopic ultrasonography (EUS) features recorded were: size, ulceration, regularity of marginal border, lobulation, shape of tumor, marginal halo, homogeneity, internal echogenic or cystic foci, and the presence of exophytic development.Results:  Significant differences were seen in size between the groups studied (P = 0.026). All tumors in the high risk group had mucosal ulceration, which was more commonly seen in the intermediate risk group compared to the low risk group (P = 0.014). All tumors in the high risk group had irregular borders, but only three cases out of 11 in the low risk group had irregular borders (P = 0.039). Thirteen cases in the low risk group and five cases in the intermediate risk group had an oval or round shape; however, only one case in the high risk group showed this (P = 0.043). The optimal size value for prediction of the intermediate and high risk group was 30 mm. Sensitivity and specificity with this value was 80% and 79%, respectively.Conclusions:  Large, especially larger than 30 mm, GISTs of the stomach with irregular borders, mucosal ulceration and a non‐oval shape on EUS suggest higher risk GISTs of the stomach. These criteria might aid in the clinical management of GISTs of the stomach.
Pegylated interferon‐α2β in combination with ribavirin does not aggravate thyroid dysfunction in comparison to regular interferon‐α2β in a hepatitis C population: Meta‐analysis
Authors: Tran Huy A , Attia John R , Jones Tracey L , Batey Robert G 
Published: November 2006

AbstractBackground:  Interferon (IFN) has been well documented to cause thyroid dysfunction, especially in high risk patients and when combined with ribavirin (RBV). There is very sparse data to assess if pegylated IFN will further aggravate the thyroid disease risk in comparison to regular IFN. The purpose of this study was to assess the risk of developing thyroid disease with pegylated IFN (pIFN) versus regular IFN (rIFN) therapy (in combination with RBV). We also pooled our results with previous studies in a meta‐analysis.Methods:  An observational study was made retrospectively of 24 patients who underwent a combination of rIFN and RBV therapy for hepatitis C virus (HCV) infection. As these patients failed to obtain an initial satisfactory response, they were retreated using pIFN and RBV. Monthly thyrotropin (TSH) levels were assessed while undergoing both treatment regimens. A meta‐analysis was performed using available published data in PubMed.Results:  No difference in TSH levels was observed when comparing rIFN/RBV with pIFN/RBV. None of the patients developed hypo‐ or hyperthyroidism. TSH levels fluctuated during the treatment but did not extend outside the reference range. No further investigation was carried out in the absence of clinical and biochemical thyroid disease. The result of the meta‐analysis failed to find any excess risk of thyroid dysfunction using pIFN above that of rIFN.Conclusions:  The pegylation of IFN, in combination with RBV, did not aggravate thyroid diseases in the hepatitis C population. This finding is reassuring and dictates that no deviation from current practice regarding thyroid surveillance is required whilst undergoing HCV treatment.
Host factors contributing to the discovery of gastric cancer after successful eradication therapy of Helicobacter pylori: Preliminary report
Authors: Takata Shunsuke , Ito Masanori , Yoshihara Masaharu , Tanaka Shinji , Imagawa Shinobu , Haruma Ken , Chayama Kazuaki 
Published: November 2006

AbstractBackground and Aim:  Clinical features of patients who develop gastric cancer after successful eradication of Helicobacter pylori are still unclear. We attempted to identify host factors associated with the discovery of gastric cancer, including changes in the background gastric mucosa in patients with atrophic gastritis.Methods:  We enrolled 101 patients (59 men, 42 women; mean age 56.0 years) who underwent successful eradication therapy. All patients had no neoplastic lesion in the stomach and were diagnosed with corpus atrophic gastritis histologically before the eradication therapy. After successful eradication, these patients were followed up by an annual endoscopic examination (mean follow‐up time 63.2 months; range 12–157 months). Fasting sera were obtained before and after eradication therapy and the serum levels of gastrin/pepsinogens were evaluated.Results:  Gastric cancer occurred during follow‐up in eight of the 101 patients (7.9%). We compared the host features between the cancer‐discovered group (n = 8) and the non‐discovered group (n = 93). We found no difference in gender, history of previous treatment of gastric cancer, and serum pepsinogen/gastrin levels at entry between them. The trends in alterations of serum markers did not differ between the two groups. However, gastric cancer was more frequently found in older patients (>54 years at eradication) than in others (P < 0.05).Conclusion:  Improvement of gastric inflammation did not correlate with the discovery of gastric cancer after eradication; however, age at the time of eradication seemed to be important. Strict follow‐up after eradication is needed in older patients with atrophic gastritis.
Benign cystic lymphangioma presenting as a pelvic mass
Authors: Erdem Savas , Iskender Cantekin , Avsar A. Filiz , Altundag Ö. Basak , Ustunyurt Emin 
Published: November 2006

AbstractWe report a case of a 48‐year‐old woman with a complaint of chronic pelvic pain with a pelvic mass not related with uterus or adnexes. Preoperative ultrasonography or contrast enhanced computed tomography did not give accurate information on the origin of tumor. At laparotomy a cystic, retroperitoneal mass was totally resected without rupture. Final histopathological examination revealed that cystic spaces with abundant lymphocytes suggesting lymphangioma. No recurrence was detected in the follow up 6 months after total resection. As a result cystic lymphangioma should be considered as a rare cause of pelvic mass in women
Transient postpartum diabetes insipidus associated with HELLP syndrome
Authors: Ellidokuz Ender , Uslan Ihsan , Demir Serap , Cevrioglu Serhan , Tufan Gulnihal 
Published: November 2006

AbstractDiabetes insipidus in pregnancy has different causes. The association of diabetes insipidus with disturbances of liver function has been reported, however, diabetes insipidus has rarely been reported in HELLP syndrome. We present a 23‐year‐old primigravida with a singleton gestation complicated by HELLP syndrome who developed postpartum diabetes insipidus. Labor was induced promptly to terminate pregnancy because of intrauterine fetal death and liver dysfunction. 1‐deamino‐8‐D‐arginine‐vasopressin was administered. Diabetes insipidus and liver dysfunction resolved within 2 weeks. Development of diabetes insipidus may result from increased vasopressinase activity mainly caused by deterioration of liver functions caused by HELLP syndrome. In pregnant women with liver disease as a result of any cause, the development of diabetes insipidus should be assessed with particular attention.
Adenofibroma of the endometrium protruding into the vaginal cavity: Findings on transvaginal ultrasonography, MRI and CT
Authors: Konishi Yoshitomo , Sato Hirokazu , Fujimoto Toshio , Tanaka Hidenori , Takahashi Osamu , Tanaka Toshinobu 
Published: November 2006

AbstractAdenofibroma is a rare benign biphasic neoplasm that is classified into the mixed epithelial and mesenchymal tumor group. We report the case of a 42‐year‐old woman with adenofibroma of the endometrium protruding into the vagina. Transvaginal ultrasonography revealed the tumor as an intravaginal mass containing multiple cystic components. Magnetic resonance imaging (MRI) showed a heterogeneous high‐intensity mass filling the vaginal cavity on T2‐weighted imaging, with a low‐contrast enhanced septum identified within the mass on gadolinium‐enhanced, T1‐weighted imaging. Contrast‐enhanced computed tomography (CT) showed a heterogeneous low‐attenuating multicystic mass filling the vaginal cavity. Although preoperative diagnosis of this rare tumor is very difficult, the combination of MRI, CT, and ultrasonography offers a useful diagnostic tool.
Special Parenting and the Combined Skills Model
Authors: Young Sadie , Hawkins Tim 
Published: November 2006

Background  The Child and Special Parenting Service provides flexible assessment, long‐term domiciliary support and home‐based teaching to intellectually disabled parents. It provides key coordination between the Learning Disability Service and the Children's Service with focussed parenting assessments, where issues of child care and protection proceedings arise.Method  Semi‐structured interviews and questionnaires were designed to evaluate user satisfaction for both recipients of the service and professionals referring to the service.Results  A high level of consumer satisfaction was found and assessment reports were highly rated. The service is seen to help prevent family breakdown, to meet user needs and to be supportive and non‐threatening by the parents.Conclusions  The combined skills model proposes a small, specialized service that acts as a linchpin for complex cases that require skills from both child and learning disability workers. The Child and Special Parenting Service receives an increasing demand for assessment. It is highly valued by the users and works strongly from an inter‐agency standpoint, coordinating complex packages of domiciliary assessment and support, and is a good practice model.
A new genus and species of ‘giant hutia’ (Tainotherium valei) from the Quaternary of Puerto Rico: an extinct arboreal quadruped?
Authors: Turvey S. T. , Grady F. V. , Rye P. 
Published: November 2006

AbstractA large incomplete rodent femur from a Quaternary cave deposit near Barahona, Puerto Rico, is established as the holotype of Tainotherium valei, a new extinct genus and species. Although biogeographic and body size similarities suggest that it may be related to the Puerto Rican giant hutia Elasmodontomys, the Antillean large‐bodied rodent family Heptaxodontidae is now interpreted as invalid, and it is impossible to assign Tainotherium to a particular caviomorph family in the absence of associated craniodental material. Tainotherium differs from other West Indian species in possessing a large femoral head, a proximally angled femoral neck, a short greater trochanter and a medially positioned lesser trochanter unconnected by an intertrochanteric crest, and a transversely flattened, anteroposteriorly bowed shaft lacking well‐defined ridges. These characters are all associated with arboreal life habits in other mammal groups. The Puerto Rican land mammal fauna was dominated by a rodent radiation occupying a wide variety of niches before human arrival in the West Indies, but although arboreality is correlated with increased likelihood of survival in Quaternary mammalian extinction events, all of this fauna is now extinct. It is unlikely that decreasing aridity and the reduction of Puerto Rican savanna‐type environments at the end of the Pleistocene contributed to the extinction of the arboreal Tainotherium, and habitat destruction by pre‐Columbian Amerindians may instead have been responsible.
Development of 51 genomic microsatellite DNA markers of guppy (Poecilia reticulata) and their application in closely related species
Authors: SHEN XUEYAN , YANG GUANPIN , LIAO MEIJIE 
Published: November 2006

AbstractFifty‐one microsatellite DNA markers of guppy (Poecilia reticulata) were developed. All of the markers detected moderate allelic variation. The number of alleles for each locus ranged from two to 10. Observed and expected heterozygosities varied from 0.10 to 0.63 and from 0.23 to 0.77, respectively. Three additional fish species of family Poeciliidae were used for the cross‐species amplification of these markers. It was found that only four to 16 markers detected polymorphism in these three fish species.
Development of microsatellite markers for the red tide‐forming harmful species Chattonella antiqua, C. marina, and C. ovata (Raphidophyceae)
Authors: DEMURA M. , KAWACHI M. , KUNUGI M. , NISHIZAWA T. , KASAI F. , WATANABE M. M. 
Published: November 2006

AbstractWe have developed 11 microsatellite markers that are specific to Chattonella antiqua, C. marina, and C. ovata, the red tide‐forming harmful phytoplanktons. The 11 loci were amplified in the three species. The number of alleles per locus ranged from 5 to 16. The three species shared most microsatellite regions, although the genetic differences in specific loci were detected among them. These markers of the Chattonella species will be beneficial for biogeographical, detailed taxonomic, studies.
Isolation and characterization of microsatellite loci in Cylindrocladium pauciramosum
Authors: WRIGHT LOUWRANCE P. , WINGFIELD BRENDA D. , CROUS PEDRO W. , WINGFIELD MICHAEL J. 
Published: November 2006

AbstractTen polymorphic microsatellite markers were developed for Cylindrocladium pauciramosum, a plant pathogen with a wide host range, which poses a serious problem in South African Eucalyptus nurseries. Polymorphism was evaluated on 43 isolates collected from Colombia and South Africa. Each locus had between three and six alleles. Testing for random mating showed multilocus equilibrium for a population of 40 isolates from a South African forestry nursery. Cross‐species transferability tested for 19 other Cylindrocladium species found amplification only in C. spathulatum, which is phylogenetically closely related to C. pauciramosum.
PCR‐RFLP markers detect 29 mitochondrial haplotypes in Pacific lamprey (Entosphenus tridentatus)
Authors: DOCKER M. F. , HAAS G. R. , GOODMAN D. H. , REID S. B. , HEATH D. D. 
Published: November 2006

AbstractWe developed five polymerase chain reaction‐based markers that detect variation in the mitochondrial genome of the Pacific lamprey, Entosphenus tridentatus, across most of its range. Two gene fragments (ND2 and ND5) were amplified and digested with three and two restriction enzymes, respectively, detecting sequence variation at 18 sites (ND2 = 13; ND5 = 5) and yielding 29 composite haplotypes among 1246 lampreys. These sequence‐based markers will be useful in a range of phylogeographical and population genetic studies.