bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of rosiglitazone and metformin on inflammatory markers and adipokines: decrease in interleukin‐18 is an independent factor for the improvement of homeostasis model assessment‐beta in type 2 diabetes mellitus
Authors: Kim Hyeong Jin , Kang Eun Seok , Kim Dae Jung , Kim So Hun , Ahn Chul Woo , Cha Bong Soo , Nam Moonsuk , Chung Choon Hee , Lee Kwan Woo , Nam Chung Mo , Lee Hyun Chul 
Published: January 2007

SummaryObjective  We examined the individual pharmacological effects of the addition of rosiglitazone and metformin to glimepiride on inflammatory markers and adipokines in patients with type 2 diabetes mellitus. We analysed the relationships between these variables, the measurements of insulin sensitivity and β‐cell function in patients treated with rosiglitazone plus glimepiride.Design and patients  One hundred twenty (120) patients with type 2 diabetes mellitus were randomized and treated with glimepiride plus rosiglitazone or glimepiride plus metformin for 12 weeks. The plasma concentrations of the inflammatory markers and adipokines were measured at baseline and after 12 weeks.Measurements  Markers of insulin sensitivity and β‐cell function were determined by the quantitative insulin sensitivity check index (QUICKI) and the homeostasis model assessment of β‐cell function (HOMA‐β), respectively. Plasma concentrations of adiponectin were measured by radioimmunoassay. Plasma concentrations of resistin, tumour necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6) and interleukin‐18 (IL‐18) were measured using ELISA.Results  Improvements in fasting insulin level, QUICKI and HOMA‐β were noted in the rosiglitazone‐treated group. Only the QUICKI value improved in the metformin‐treated group. Adiponectin concentrations significantly increased in the rosiglitazone‐treated group after 12 weeks. Significant decreases in resistin, C‐reactive protein, TNF‐α, IL‐6 and IL‐18 were seen in the rosiglitazone‐treated patients but not in the metformin‐treated patients. The independent risk factor for the HOMA‐β change according to stepwise multivariate regression analysis was a change in IL‐18.Conclusions  Rosiglitazone, but not metformin, improved the plasma concentrations of inflammatory markers and adipokines in patients with type 2 diabetes mellitus. A decrease in IL‐18 is an independent factor for the improvement of HOMA‐β in type 2 diabetes mellitus.
Central pulse wave velocity is responsible for increased brachial‐ankle pulse wave velocity in subclinical hypothyroidism
Authors: Nagasaki Toshiki , Inaba Masaaki , Kumeda Yasuro , Hiura Yoshikazu , Yamada Shinsuke , Shirakawa Kumi , Ishimura Eiji , Nishizawa Yoshiki 
Published: January 2007

SummaryObjective  Subclinical hypothyroidism affects 5–15% of the general population, and is associated with increased morbidity from cardiovascular disease. We recently reported a significant increase in brachial‐ankle pulse wave velocity (baPWV), a parameter of arterial stiffening and an independent predictor for the presence of cardiovascular disease, in subclinical hypothyroidism. The current study was performed to assess which arterial segment is responsible for enhanced baPWV in subclinical hypothyroidism.Patients and methods  Central PWV (PWV in heart‐femoral segments), peripheral PWV (PWV in femoral‐ankle segments), and baPWV were measured in subclinical hypothyroid patients and normal subjects.Results  Central PWV, baPWV, and peripheral PWV were significantly higher in subclinical hypothyroid patients than in normal subjects. BaPWV was significantly and positively correlated with central and peripheral PWV in both groups. However, a significant and positive correlation between central and peripheral PWV in normal subjects was not found in subclinical hypothyroid patients. Moreover, stepwise regression analysis showed that the association of central PWV with baPWV was stronger than that of peripheral PWV, whereas in normal subjects central PWV was not associated with baPWV.Conclusions  Our results demonstrate that central and peripheral PWV are significantly higher in subclinical hypothyroid patients, and that the increase in baPWV depends more strongly on central PWV than on peripheral PWV in these patients. This suggests that increased elastic arterial stiffening of the aorta, rather than of peripheral muscular arteries, might be more responsible for increased general arterial stiffening in subclinical hypothyroid patients.
A mutation and expression analysis of the oncogene BRAF in pituitary adenomas
Authors: Ewing Iain , Pedder‐Smith Stephen , Franchi Giulia , Ruscica Massimiliano , Emery Michelle , Vax Vladimir , Garcia Edwin , Czirják Sándor , Hanzély Zoltán , Kola Blerina , Korbonits Márta , Grossman Ashley B. 
Published: January 2007

SummaryObjective  BRAF is an oncogene that is commonly mutated in both melanomas and papillary thyroid carcinomas, usually at position V600E that leads to constitutive activity in the Ras–mitogen‐activated protein kinase (MAPK) pathway. We speculated that this same gene may be either mutated at this site, or overexpressed, in pituitary adenomas.Design and measurements  We sequenced 37 pituitary adenomas for a mutation at the V600E position. In addition, we investigated B‐Raf mRNA expression in normal pituitary (n = 5) and nonfunctioning pituitary adenomas (NFPA) (n = 6) by semiquantitative PCR, and in a further 27 pituitary adenomas of various types and 10 normal pituitaries using real‐time quantitative PCR. Finally, we explored B‐Raf protein expression in 10 normal pituitaries and 12 NFPAs.Results  No sequence mutations for the substitution V600E were identified. B‐Raf mRNA was overexpressed in pituitary adenomas compared to normal pituitary, and this was entirely due to overexpression in NFPAs. NFPAs also showed very variable expression of B‐Raf protein, but those tumours showing highest levels of B‐Raf mRNA expressed the most B‐Raf protein.Conclusions  Mutations previously seen in the majority of melanomas and a substantial minority of papillary thyroid carcinomas are not a frequent finding in pituitary adenomas. However, overexpression of B‐Raf mRNA and protein may be a feature of NFPAs, highlighting overactivity of the Ras‐B‐Raf‐MAP kinase pathway in these tumours.
Serum adiponectin and leptin levels and insulin resistance in children born large for gestational age are affected by the degree of overweight
Authors: Vasileios Giapros , Eleni Evagelidou , Anna Challa , Dimitrios Kiortsis , Aikaterini Drougia , Styliani Andronikou 
Published: January 2007

SummaryObjective  Children born large for gestational age (LGA) are prone to develop insulin resistance later in life. One factor that affects insulin sensitivity is the hormone adiponectin. The aim of this study was to determine whether being LGA has an impact on serum adiponectin and leptin levels and insulin resistance parameters during childhood, taking into account the severity of overweight.Study design  Serum levels of adiponectin, leptin, fasting glucose and insulin, homeostasis model assessment insulin resistance index (HOMA‐IR), and anthropometric indices were evaluated in groups of non‐obese children aged 6·5–8 years, born appropriate for gestational age (AGA, n = 40) or LGA (n = 41), matched for age, gender, height, weight and body mass index. The LGA group was divided in two subgroups according to the degree of overweight: (a) LGA with birthweight 90th−97th percentile (n = 25); and (b) LGA with birthweight > 97th percentile (n = 16).Results  LGA children had a higher mean serum adiponectin level than AGA children: 17·0 ± 9 vs. 11·1 ± 5 (µg/ml) (P < 0·01). LGA children had also higher insulin 6·2 ± 2·8 vs. 4·8 ± 2·4 (µU/ml) (P < 0·05) and HOMA‐IR 1·32 ± 0·66 vs. 1·02 ± 0·55 (P < 0·01) than AGA children. Children born LGA > 97th percentile had a significantly higher mean serum leptin level than both AGA and LGA 90th−97th percentile children (17 ± 13, 9·6 ± 9·5, 7·8 ± 7·9 ng/ml, respectively, P < 0·05), and more severely affected insulin resistance indices than LGA 90th−97th percentile children. In the regression analysis, birthweight was found to be an independent predictor of adiponectin serum levels.Conclusion  Prepubertal LGA‐born children had a higher mean serum adiponectin levels than matched AGA controls despite the fact that they were more insulin resistant. The degree of excess in utero weight gain appears to influence the metabolic profile in LGA‐born prepubertal children. Further studies are needed to delineate the role of adiponectin in the risk of development of insulin resistance in children born LGA.
Kickboxing sport as a new cause of traumatic brain injury‐mediated hypopituitarism
Authors: Tanriverdi Fatih , Unluhizarci Kursad , Coksevim Bekir , Selcuklu Ahmed , Casanueva Felipe F. , Kelestimur Fahrettin 
Published: January 2007

SummaryObjective  Traumatic brain injury, which is a frequent and a worldwide important public health problem, may result in pituitary dysfunction. Concussion, a common type of lesion after traumatic brain injury, is an injury associated with sports including boxing and kickboxing. Kickboxing is one of the most popular martial arts and approximately 1‐million people around the world participate in kickboxing sport. Head is the most common site of injury in amateur and professional kickboxers. Pituitary consequences of chronic repetitive head trauma in kickboxing have not been investigated until now. Therefore, the present study was designed to investigate the pituitary function in both retired and active amateur kickboxers.Patients and Design  Twenty‐two amateur kickboxers who have boxed in national and international championships (16 men, 6 women) with a mean age of 27·3 ± 7·1 years, and 22 age‐ and sex‐matched healthy controls were included in the study. Basal hormone levels were obtained from the participants. To assess GH‐IGF‐I axis, GHRH + GHRP‐6 test and glucagon stimulation tests were used. Hypothalamo‐pituitary‐adrenal axis was assessed by glucagon stimulation test.Results  When mean basal hormone levels were compared between kickboxers and the controls, IGF‐I level was significantly lower in kickboxers (P < 0·05). Five (22·7%) and two (9·1%) of the 22 kickboxers had GH deficiency had ACTH deficiency, respectively. There were significant negative correlations between IGF‐I levels and age, duration of sports and number of bouts (P < 0·05).Conclusions  Present data clearly demonstrate for the first time that amateur kickboxing is a novel cause of hypopituitarism and kickboxers are at a risk for hypopituitarism especially isolated GH deficiency. Therefore, participants of the combative sports who were exposed to chronic repetitive head trauma need to be screened.
Dissolved organic nitrogen and carbon in pastoral soils: the New Zealand experience
Authors: Ghani A. , Dexter M. , Carran R. A. , Theobald P. W. 
Published: January 2007

SummaryDissolved organic nitrogen (DON) and dissolved organic carbon (DOC) in soils are increasingly recognized as important components of nutrient cycling and biological processes in soil‐plant ecosystems. The aims of this study were to: (i) quantify the pools of DON and DOC in a range of New Zealand pastoral soils; (ii) compare the effects of land use changes on these pools; and (iii) examine the seasonal variability associated with these two components of dissolved organic matter. Soil samples (0–7.5 cm depth) from 93 pastoral sites located in Northland, Waikato, Bay of Plenty and Otago/Southland, New Zealand, were collected in autumn. Adjacent sites under long‐term arable cropping or native vegetation and forestry land use were also sampled at the same time to estimate the impacts of different land use on DON and DOC in these soils. Twelve dairy and 12 sheep and or beef pastures were sampled in winter, spring, summer and autumn for a 2‐year period to study the seasonal fluctuations of DON and DOC. A field incubation study was also carried out in a grazed pasture to examine fluctuations in the concentrations of and and DON levels in soil. Other soil biological properties, such as microbial biomass‐C, biomass‐N and mineralizable N, were also measured. Pastoral soils contained the greatest amounts of DON (13–93 mg N kg−1 soil, equivalent to 8–55 kg N ha−1) and DOC (73–718 mg C kg−1 soil, equivalent to 44–431 kg C ha−1), followed by cropping and native vegetation and forestry soils. The DON concentration in soils was found to be more seasonally variable than DOC. There was approximately 80% fluctuation in the concentration of DON in winter from the annual mean concentration of DON, while DOC fluctuated between 23 and 28% at the dairy and the sheep and beef monitoring sites. Similar fluctuations in the concentrations of DON were also observed in the field incubation studies. These results indicate that DON is a dynamic pool of N in soils. There was a strong and significant positive correlation between DON and DOC in pastoral soils (r = 0.71, P < 0.01). There were also significant positive correlations between DON and total soil C (r = 0.59, P < 0.01), total soil N (r = 0.62, P < 0.01) and mineralizable N (r = 0.47, P < 0.01). The rather poor correlations between total soil C and N with DOC and DON, suggest other biogeochemical processes may be influencing concentrations of DOC and DON in these soils. Given the size of DON and DOC pools in the pastoral soils, we suggest that these pools of C and N should be taken into account when assessing the impact of pastoral land use on soil C and N enrichment of surface and groundwater.
Factors controlling aggregation in a minimum and a conventionally tilled undulating field
Authors: De Gryze S. , Bossuyt H. , Six J. , Van Meirvenne M. , Govers G. , Merckx R. 
Published: January 2007

SummaryWind and water erosion induce breakdown of soil aggregates and loss of soil organic matter. Whereas most of the relations between aggregation and its driving factors have been established on a plot scale, these relations might be very different within an undulating landscape where both erosion (by wind or water) and deposition occur. The aim of this study was to investigate to what degree spatial patterns in soil variables influence spatial patterns in aggregation under different tillage intensities. We studied an agricultural field of about 3 ha in the silty region of Belgium. The site was split into a conventional tillage (CT) and a minimum tillage (MT) system. Within the field, 396 geo‐referenced surface soil samples (0–5 cm) were taken and analyzed for organic matter content, quantity of aggregates and a number of other soil properties. Under CT, 28.5% of the total sample variation was explained by the occurrence of depositional areas, 20.8% by the amount of soil organic matter, and 13.8% by the presence of a clay‐rich B horizon which surfaced due to progressive water and tillage erosion. Regression analysis revealed that 27% of the variation in the quantity of macroaggregates (>0.25 mm) was accounted for by these three factors. Under MT, 27.1% of the total sample variation was related to the surface cover of Tertiary sand, 22.6% to the amount of soil organic matter, and 13% to erodibility. These three factors explained 53% of the variation in the quantity of macroaggregates. In the CT system, the correlation between grass‐ or maize‐ carbon and the quantity of macroaggregates was strongly linked to erodibility, while this was not the case in the MT system. We concluded that at this site, macroaggregation is dominated by landscape‐scale processes (such as water or tillage erosion) rather than determined by the commonly considered local variables (such as small variations in texture or organic matter content).
A method for deriving net primary productivity and component respiratory fluxes from tower‐based eddy covariance data: a case study using a 17‐year data record from a Douglas‐fir chronosequence
Authors: SCHWALM CHRISTOPHER R. , BLACK T. ANDREW , MORGENSTERN KAI , HUMPHREYS ELYN R. 
Published: January 2007

AbstractConventional gap‐filling procedures for eddy covariance (EC) data are limited to calculating ecosystem respiration (RE) and gross ecosystem productivity (PG) as well as missing values of net ecosystem productivity (FNEP). We develop additional postprocessing steps that estimate net primary productivity (PN), autotrophic (Ra), and heterotrophic respiration (Rh). This is based on conservation of mass of carbon (C), Monte Carlo (MC) simulation, and three ratios: C use efficiency (CUE, PN to PG), Ra to RE, and FNEP to RE. This procedure, along with the estimation of FNEP, RE, and PG, was applied to a Douglas‐fir dominated chronosequence on Vancouver Island, British Columbia, Canada. The EC data set consists of 17 site years from three sites: initiation (HDF00), pole/sapling (HDF88), and near mature (DF49), with stand ages from 1 to 56 years. Analysis focuses on annual C flux totals and C balance ratios as a function of stand age, assuming a rotation age of 56 years. All six C balance terms generally increased with stand age. Average annual PN by stand was 213, 750, and 1261 g C m−2 yr−1 for HDF00, HDF88, and DF49, respectively. The canopy compensation point, the year when the chronosequence switched from a source to a sink of C, occurred at stand age ca. 20 years. HDF00 and HDF88 were strong and moderate sources (FNEP=−581 and −138 g C m−2 yr−1), respectively, while DF49 was a moderate sink (FNEP=294 g C m−2 yr−1) for C. Differences between sites were greater than interannual variation (IAV) within sites and highlighted the importance of age‐related effects in C cycling. The validity of the approach is discussed using a sensitivity analysis, a comparison with growth and yield estimates from the same chronosequence, and an intercomparison with other chronosequences.
Mature semiarid chaparral ecosystems can be a significant sink for atmospheric carbon dioxide
Authors: LUO HONGYAN , OECHEL WALTER C. , HASTINGS STEVEN J. , ZULUETA ROMMEL , QIAN YONGHAI , KWON HYOJUNG 
Published: January 2007

AbstractCarbon flux in arid and semiarid area shrublands, especially in old‐growth shrub ecosystems, has been rarely studied using eddy covariance techniques. In this study, eddy covariance measurements over a 100‐year old‐growth chamise‐dominated chaparral shrub ecosystem were conducted for 7 years from 1996 to 2003. A carbon sink, from −96 to −155 g C m−2 yr−1, was determined under normal weather conditions, while a weak sink of −18 g C m−2 yr−1 and a strong source of 207 g C m−2 yr−1 were observed as a consequence of a severe drought. The annual sink strength of carbon in the 7‐year measurement period was −52 g C m−2 yr−1. The results from our study indicate that, in contrast to previous thought, the old‐growth chaparral shrub ecosystem can be a significant sink of carbon under normal weather conditions and, therefore, be an important component of the global carbon budget.
Spring feeding by pink‐footed geese reduces carbon stocks and sink strength in tundra ecosystems
Authors: Van Der WAL RENÉ , SJÖGERSTEN SOFIE , WOODIN SARAH J. , COOPER ELISABETH J. , JÓNSDÓTTIR INGIBJÖRG S. , KUIJPER DRIES , FOX TONY A. D. , HUISKES A. D. 
Published: January 2007

AbstractTundra ecosystems are widely recognized as precious areas and globally important carbon (C) sinks, yet our understanding of potential threats to these habitats and their large soil C store is limited. Land‐use changes and conservation measures in temperate regions have led to a dramatic expansion of arctic‐breeding geese, making them important herbivores of high‐latitude systems. In field experiments conducted in high‐Arctic Spitsbergen, Svalbard, we demonstrate that a brief period of early season belowground foraging by pink‐footed geese is sufficient to strongly reduce C sink strength and soil C stocks of arctic tundra. Mechanisms are suggested whereby vegetation disruption due to repeated use of grubbed areas opens the soil organic layer to erosion and will thus lead to progressive C loss. Our study shows, for the first time, that increases in goose abundance through land‐use change and conservation measures in temperate climes can dramatically affect the C balance of arctic tundra.
Elevated CO2 enhances nitrogen fixation and growth in the marine cyanobacterium Trichodesmium
Authors: LEVITAN O. , ROSENBERG G. , SETLIK I. , SETLIKOVA E. , GRIGEL J. , KLEPETAR J. , PRASIL O. , BERMAN‐FRANK I. 
Published: January 2007

AbstractThe increases in atmospheric pCO2 over the last century are accompanied by higher concentrations of CO2(aq) in the surface oceans. This acidification of the surface ocean is expected to influence aquatic primary productivity and may also affect cyanobacterial nitrogen (N)‐fixers (diazotrophs). No data is currently available showing the response of diazotrophs to enhanced oceanic CO2(aq). We examined the influence of pCO2 [preindustrial∼250 ppmv (low), ambient∼400, future∼900 ppmv (high)] on the photosynthesis, N fixation, and growth of Trichodesmium IMS101. Trichodesmium spp. is a bloom‐forming cyanobacterium contributing substantial inputs of ‘new N’ to the oligotrophic subtropical and tropical oceans. High pCO2 enhanced N fixation, C : N ratios, filament length, and biomass of Trichodesmium in comparison with both ambient and low pCO2 cultures. Photosynthesis and respiration did not change significantly between the treatments. We suggest that enhanced N fixation and growth in the high pCO2 cultures occurs due to reallocation of energy and resources from carbon concentrating mechanisms (CCM) required under low and ambient pCO2. Thus, in oceanic regions, where light and nutrients such as P and Fe are not limiting, we expect the projected concentrations of CO2 to increase N fixation and growth of Trichodesmium. Other diazotrophs may be similarly affected, thereby enhancing inputs of new N and increasing primary productivity in the oceans.
Up‐regulation of Fas (CD95) expression in tumour cells in vivo
Authors: Peshes‐Yaloz Naama , Rosen Dalia , Sondel Paul M. , Krammer Peter H. , Berke Gideon 
Published: January 2007

SummaryBoth the function and regulation of Fas expression in tumours is poorly understood. Our laboratory has reported that cultured, low Fas‐expressing tumours undergo massive, yet reversible, up‐regulation of cell surface Fas expression when injected into mice. The present study was aimed at determining what causes this enhanced Fas expression and whether the newly expressed Fas functions as a death receptor. Newly expressed Fas is indeed capable of inducing apoptosis. Based on our observation that Fas induction is reduced when tumour cells are injected into immune‐deficient mice, we propose that Fas up‐regulation in vivo involves the host's immune system. Accordingly, Fas up‐regulation occurs in vitro when low Fas‐expressing tumour cells are cocultured with lymphoid cells. Furthermore ascitic fluid extracted from tumour‐bearing mice trigger Fas up‐regulation in low Fas expressing tumours. This last finding suggests that a soluble factor(s) mediates induction of Fas expression. The best candidate for this soluble factor is nitric oxide (NO) based on the following observations: the factor in the ascites is unstable; Fas expression is induced to a lesser degree after injection into inducible NO synthase (NOS)‐deficient (iNOS–/–) mice when compared to control mice; similarly, coculture with iNOS–/– splenocytes induces Fas less effectively than coculture with control splenocytes; and finally, the NO donor SNAP induces considerable Fas up‐regulation in tumours in vitro. Our model is that host lymphoid cells in response to a tumour increase NO synthesis, which in turn causes enhanced Fas expression in the tumour.