bluuebunny/crossref_metadata_2025 huggingface dataset:
Transportation of radiation through opaque magnetoactive plasmas by the means of parametrically induced transparency
Authors: Kryachko A. Yu. , Tokman M. D. , Westerhof E.
Published: July 2006

The concept of “parametrically induced transparency” (PIT) is introduced: a variant of electromagnetically induced transparency (EIT) in inhomogeneous media, in which the EIT regime takes place in only a limited spatial region in which the signal wave is scattered into a transporting wave by a high power drive wave. It is shown how PIT can be employed for the extraction of radiation from the core of overdense toroidal plasmas. Numerical examples are given for the TEXTOR (Torus Experiment for Technology Oriented Research) tokamak [U. Samm, Fusion Sci. Technol. 47, 73 (2005), Special Issue on TEXTOR], which use the existing gyrotron as the high power drive source.
Essential role of TAK1 in thymocyte development and activation
Authors: Liu Hong-Hsing , Xie Min , Schneider Michael D. , Chen Zhijian J.
Published: July 2006

The protein kinase TAK1 mediates the activation of NF-κB in response to stimulation by proinflammatory cytokines and microbial pathogens in the innate immunity pathways. However, the physiological function of TAK1 in the adaptive immunity pathways is unclear. By engineering mice lacking TAK1 in T cells, here, we show that TAK1 is essential for thymocyte development and activationin vivo. Deletion of TAK1 prevented the maturation of single-positive thymocytes displaying CD4 or CD8, leading to reduction of T cells in the peripheral tissues. Thymocytes lacking TAK1 failed to activate NF-κB and JNK and were prone to apoptosis upon stimulation. Our results provide the genetic evidence that TAK1 is required for the activation of NF-κB in thymocytes and suggest that TAK1 plays a central role in both innate and adaptive immunity.
Regulatory T cells suppress systemic and mucosal immune activation to control intestinal inflammation
Authors: Izcue Ana , Coombes Janine L. , Powrie Fiona
Published: July 2006

Summary:  The gastrointestinal (GI) tract is the main interface where the body encounters exogenous antigens. It is crucial that the local response here is tightly regulated to avoid an immune reaction against dietary antigens and commensal flora while still mounting an efficient defense against pathogens. Faults in establishing intestinal tolerance can lead to disease, inducing local and often also systemic inflammation. Studies in human as well as in animal models suggest a role for regulatory T cells (Tregs) in maintaining intestinal homeostasis. Transfer of Tregs can not only prevent the development of colitis in animal models but also cure established disease, acting both systemically and at the site of inflammation. In this review, we discuss the major regulatory pathways, including transforming growth factor‐β (TGF‐β), interleukin‐10 (IL‐10), and cytotoxic T‐lymphocyte antigen‐4 (CTLA‐4), and their role in Treg‐mediated control of systemic and mucosal responses. In addition, we give an overview of the known mechanisms of lymphocyte migration to the intestine and discuss how CD103 expression can influence the balance between regulatory and effector T cells. Further understanding of the factors that control the activity of Tregs in different immune compartments may facilitate the design of strategies to target regulation in a tissue‐specific way.
In‐hospital cardiac arrest is associated with use of non‐antiarrhythmic QTc‐prolonging drugs
Authors: De Bruin Marie L. , Langendijk Pim N. J. , Koopmans Richard P. , Wilde Arthur A. M. , Leufkens Hubert G. M. , Hoes Arno W.
Published: July 2006

Aims

QTc interval‐prolonging drugs have been linked to cardiac arrhythmias, cardiac arrest and sudden death. In this study we aimed to quantify the risk of cardiac arrest associated with the use of non‐antiarrhythmic QTc‐prolonging drugs in an academic hospital setting.

Methods

We performed a case–control study in which patients, for whom intervention of the advanced life support resuscitation team was requested for cardiac arrest between 1995 and 2003 in the Academic Medical Centre, Amsterdam, were compared with controls regarding current use of non‐antiarrhythmic QTc‐prolonging drugs. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression, adjusting for potential confounding factors.

Results

A statistically significant increased risk of cardiac arrest (OR 2.1, 95% CI 1.2, 3.5) was observed in patients who received QTc‐prolonging drugs (42/140). The risk was more pronounced in patients receiving doses > 1 defined daily dose (OR 2.5, 95% CI 1.1, 5.9), patients taking > 1 QTc‐prolonging drug simultaneously (OR 4.8, 95% CI 1.6, 14) and patients taking pharmacokinetic interacting drugs concomitantly (OR 4.0, 95% CI 1.2, 13).

Conclusions

Use of non‐antiarrhythmic QTc‐prolonging drugs in hospitalized patients with several underlying disease is associated with an increased risk of cardiac arrest. The effect is dose related and pharmacokinetic drug–drug interactions increase the risk substantially. Physicians caring for inpatients should be made aware of the fact that these non‐antiarrhythmic drugs may be hazardous, so that potential risks can be weighed against treatment benefits and additional cardiac surveillance can be requested, if necessary.
Vancomycin pharmacokinetics in preterm neonates and the prediction of adult clearance
Authors: Anderson Brian J. , Allegaert Karel , Van den Anker John N. , Cossey Veerle , Holford Nicholas H. G.
Published: July 2006

What is already known about this subject

• Effects of size, renal function, age (postnatal age, gestational age and postmenstrual age) as predictors of vancomycin clearance in premature neonates are established, but the relative contribution of each component remains poorly quantified, largely because these variables are closely correlated.

• We have quantified the covariates contributing to vancomycin clearance population parameter variability in order to establish the major covariates required for dosing predictions. Size, standardized using allometric models, was the primary covariate used in our analysis.

What this study adds

• Size explained 49.8%, postmenstrual age 18.2% and renal function 14.1% of clearance variability.

• Descriptors of the relationship between age and clearance in premature neonates vary.

• The use of a variable slope sigmoidal model to describe the relationship between clearance and postmenstrual age predicted an adult clearance of 3.79 l h−1 70 kg−1 (95% confidence interval 2.76, 4.98) from premature neonatal data.

Aim

To identify and quantify factors describing the variability of vancomycin clearance in premature neonates.

Methods

Population pharmacokinetics were estimated (NONMEM) in 214 neonates [postmenstrual age (PMA) 30.4 weeks, range 24–34 weeks; postnatal age 11.9 days, range 1–27 days; weight 1.30 kg, range 0.42–2.6 kg] using therapeutic drug monitoring data. Covariate analysis included weight, PMA, serum creatinine, use of inotropes or ibuprofen, positive blood culture and respiratory support. A one‐compartment linear disposition model with zero order input and first‐order elimination was used to describe the data (604 observations).

Results

The population estimate for volume of distribution (V) was 39 l 70 kg−1 (coefficient of variation 19.4%). Clearance (CL) increased from 0.897 l h−1 70 kg−1 at 24 weeks PMA to 2.02 l h−1 70 kg−1 by 34 weeks PMA. The between‐subject variability for CL was 18.6% and the between‐occasion variability was 12.2%. The use of ibuprofen reduced clearance, but this effect was attributable to reduced renal function. Overall, 82% of the variability of CL was predictable. Size explained 49.8%, PMA 18.2% and renal function 14.1%. The use of a variable slope sigmoidal model to describe the relationship between clearance and PMA predicted an adult clearance of 3.79 l h−1 70 kg−1 (95% confidence interval 2.76, 4.98).

Conclusions

Size, renal function and PMA are the major contributors to clearance variability in premature neonates. The small (18%) unexplained variability in clearance suggests target concentration intervention is unnecessary if size, age and renal function are used to predict the dose. Extrapolation to an adult clearance from neonatal data is possible using allometric size models and a function describing clearance maturation.
Pharmacokinetics, safety and tolerance of single‐ and multiple‐dose adefovir dipivoxil in healthy Chinese subjects
Authors: Sun De‐qing , Wang Hai‐sheng , Ni Mei‐yuan , Wang Ben‐jie , Guo Rui‐chen
Published: July 2006

Aims

To assess the pharmacokinetics, safety and tolerance of single‐ and multiple‐dose adefovir dipivoxil (ADV) in healthy Chinese subjects.

Methods

Forty‐two healthy subjects were randomized into 5, 10, 20, 40 and 60‐mg dose groups for safety assessment. Nine and 10 healthy males were enrolled for a single‐dose pharmacokinetic profile and assessment of the effect of food on the pharmacokinetics of adefovir (PMEA), respectively. Another 10 healthy subjects were enrolled for a multiple‐dose safety assessment and pharmacokinetic profile. Safety and tolerance were evaluated by monitoring adverse events and laboratory parameters, and pharmacokinetics were assessed by determining PMEA concentrations with a validated LC‐MS/MS method.

Results

No serious adverse events occurred. The pharmacokinetic parameters of PMEA following ADV 10, 20 and 40 mg were: geometric mean [95% confidence interval (CI)] for AUC0−24 h 227 (205, 253), 423 (361, 506) and 686 (585, 828) µg l−1 h, Cmax 23.0 (20.7, 27.3), 47.4 (42.8, 53.2) and 83.6 (72.6, 97.4) µg l−1, arithmetic mean (95% CI) for t1/2 6.8 (6.3, 7.3), 7.4 (6.7, 8.1) and 7.7 (6.5, 8.9) h, median value (range) for tmax 1.00 (1.00–2.00), 0.75 (0.75–2.50) and 1.00 (0.75–2.00) h, respectively. The steady‐state pharmacokinetics parameters were similar to those following a single dose. The AUC of PMEA was unaffected by food.

Conclusion

ADV is safe and well tolerated in healthy Chinese subjects. The mean Cmax of PMEA is proportional to dose, but the linearity of AUC needs further study. There is no accumulation following multiple doses of ADV and the extent of absorption of PMEA is unaffected by food.
Effect ofABCB1(MDR1) haplotypes derived from G2677T/C3435T on the pharmacokinetics of amlodipine in healthy subjects
Authors: Kim Kyoung‐Ah , Park Pil‐Whan , Park Ji‐Young
Published: July 2006

Aim

We aimed to investigate the effect of theABCB1gene on the pharmacokinetics of amlodipine.

Methods

Based on polymorphisms of theABCB1gene at positions 2677 and 3435, 26 healthy male participants were divided into three groups: subjects with 2677GG/3435CC (n = 9), 2677GT/3435CT (n = 9) and 2677TT/3435TT (n = 8). After a single‐dose administration of 5 mg amlodipine, plasma concentrations of amlodipine were measured and its pharmacokinetic characteristics were compared according toABCB1genotype.

Results

The area under the plasma concentration–time curve was significantly lower in subjects with 2677TT/3435TT (140.8 ± 35.6 ng h−1 ml−1) and 2677GT/3435CT (149.8 ± 40.1 ng h−1 ml−1) than in those with 2677GG/3435CC (208.6 ± 39.2 ng h−1 ml−1) [95% confidence interval (CI) on the difference, 2677GG/3435CCvs.2677GT/3435CT 12.0, 105.6,P < 0.01; 2677GG/3435CCvs.2677TT/3435TT 19.6, 116.0,P < 0.01; 2677GT/3435CTvs.2677TT/3435TT − 39.2, 57.2,P > 0.05]. The peak plasma concentrations were highest in subjects with 2677GG/3435CC (3.8 ± 0.5 ng ml−1), lower in subjects with 2677GT/3435CT (3.2 ± 0.5 ng ml−1) and 2677TT/3435TT (2.7 ± 0.5 ng ml−1) in rank and showed a significant difference between those with 2677GG/3435CC and with 2677TT/3435TT (95% CI on the difference 0.4, 2.0,P < 0.01). However, the oral clearance was higher in subjects with 2677TT/3435TT (37.7 ± 10.2 l h−1) than in those with 2677GT/3435CT (35.7 ± 9.9 l h−1) and with 2677GG/3435CC (24.8 ± 5.4 l h−1) and exhibited a significant difference betweenABCB1genotype groups (95% CI on the difference, 2677GG/3435CCvs.2677GT/3435CT − 21.5, − 0.3,P < 0.05; 2677GG/3435CCvs.2677TT/3435TT − 23.8, − 2.0,P < 0.05).

Conclusion

Amlodipine pharmacokinetics was affected by the genetic polymorphisms of theABCB1gene in humans. These findings may provide a plausible explanation for interindividual variation in the disposition of amlodipine, although our study could not explain the exact mechanism(s) by which the polymorphicABCB1gene paradoxically reduces the plasma levels of amlodipine. Further evaluation is thus warranted.
Intraoperative haemodynamic stability in patients with phaeochromocytoma – minimally invasive vs conventional open surgery
Authors: Weismann Dirk , Fassnacht Martin , Weinberger Fabian , Hamelmann Wulf , Diehl Saskia , Lorenz Kerstin , Baerlehner Eckhard , Reincke Martin , Beuschlein Felix , Knoefel Wolfram , Nies Christoph , Hahner Stefanie , Allolio Bruno
Published: July 2006

Objective  There is conflicting evidence, whether or not minimally invasive adrenalectomy (MA) is associated with an increased perioperative cardiovascular instability in phaeochromocytomas compared to conventional open adrenalectomy (CA).

Design and patients  In a retrospective analysis of 49 patients with phaeochromocytoma we compared 27 cases of MA to 22 cases of CA by assessing intraoperative haemodynamic parameters and perioperative complications. Patients undergoing MA for adrenocortical adenomas (aldosteronomas n = 15, inactive adenomas n = 13) served as controls. Additionally, we investigated the effect of phenoxybenzamine (POB) pretreatment on intraoperative cardiovascular stability in 42 patients (ranked by maximum daily POB‐dose) by comparing the highest (n = 10) with the lowest (n = 10) POB dose quartile (0·32 ± 0·2 and 2·17 ± 0·6 mg/kg/day, P < 0·001).

Results  In phaeochromocytomas we found no significant difference in intraoperative haemodynamic parameters or complications when comparing MA with CA. In comparison to adrenocortical adenomas, MA in phaeochromocytomas was associated with a significantly higher maximum systolic BP (188 ± 29 vs 154 ± 22 mmHg, P < 0·001), more frequent hypertensive episodes (1[0–4]vs 0[0–1], P < 0·001), more episodes of systolic BP > 200 mmHg (0[0–4]vs 0[0–1], P = 0·03) and a higher demand for intraoperative fluids (3194 ml vs 1750 ml, P < 0·001). Most haemodynamic parameters did not differ significantly between high‐dose POB pretreatment and low‐dose POB pretreatment, but high‐dose POB pretreatment was associated with a significantly higher intraoperative heart rate (120 ± 19·5 vs 94 ± 15·2 min−1, P < 0·01).

Conclusion  There is no significant difference in haemodynamic stability between MA and CA in phaeochromocytomas, but it is significantly inferior when compared to MA for cortical adenomas. We could not detect a beneficial effect of high‐dose compared to low‐dose POB pretreatment on intraoperative cardiovascular stability.
Testicular function after 131I therapy for hyperthyroidism
Authors: Ceccarelli Claudia , Canale Domenico , Battisti Paolo , Caglieresi Carolina , Moschini Cecilia , Fiore Emilio , Grasso Lucia , Pinchera Aldo , Vitti Paolo
Published: July 2006

Objective  Radioiodine‐131 is commonly used for treatment of hyperthyroidism but there are few available data on the effects of this treatment on male gonadal function. The untoward effects of 131I have been mainly studied in male patients treated with high doses for thyroid cancer. In the present work we studied the absorbed radiation dose to the testes and testicular function in hyperthyroid men after 131I treatment.

Patients and measurements  Nineteen male hyperthyroid patients were enrolled in the study before 131I therapy. Seventeen of the patients had Graves’ disease and two had toxic adenoma. The study was subdivided into two parts: a dosimetric and a clinical study. Six patients were enrolled for the dosimetric study and 13 for the clinical study. The β dose delivered to the testes was evaluated by the Medical Internal Radiation Dose (MIRD) method. The γ dose was measured by thermoluminescent dosimeters (TLDs) placed on the skin overlying the inferior poles of the testes for 3 weeks after therapy. The clinical evaluation included hormone determination, ultrasound (US) of the testes and sperm analysis. Patients were followed up for 12 months after 131I therapy.

Results  In the dosimetric study, the β dose absorbed in the testes was 12·5 ± 8·8 mGy (range 29–15 mGy) and the γ dose was 15·8 ± 5·3 mGy (range 24–11 mGy). The total dose to the testes for administered activity unit was 39 ± 14 µGy/MBq (range 27–86 µGy/MBq). In the clinical study, FSH did not change significantly after 131I treatment for the majority of patients. Serum testosterone (T) and the T/LH ratio were significantly reduced 45 days after treatment and returned to basal levels after 12 months. Ten out of 15 hyperthyroid patients (67%) had low sperm motility before treatment. A significant increase in progressive motility was observed after 131I therapy (Friedman test χ2 = 12·65, P = 0·01). Conversely, there was no significant variation in sperm concentration and percentage of normal forms after 131I.

Conclusions  After 131I therapy, germinal epithelium and Leydig cell function undergo only marginal changes, which may have some significance in subjects with a pre‐existing fertility impairment.
Impairment of GH responsiveness to combined GH‐releasing hormone and arginine administration in adult patients with Prader‐Willi syndrome
Authors: Grugni G. , Marzullo P. , Ragusa L. , Sartorio A. , Trifirò G. , Liuzzi A. , Crinò A. ,   on behalf of the Genetic Obesity Study Group of the Italian Society of Pediatric Endocrinology and Diabetology
Published: July 2006

Objective It is unclear if poor health outcomes of adult patients with Prader‐Willi syndrome (PWS) are influenced by GH deficiency (GHD). Few studies have been focused on PWS adults, but further information on the concomitant role of obesity on GH/IGF‐I axis function is needed. The aim of our study was to investigate the prevalence of GHD in a large group of adult subjects with genetically confirmed PWS.

Design and subjects We studied the GH response to a combined administration of GHRH (1 µg/kg i.v. at 0 minutes) and arginine (ARG) (30 g i.v., infused from 0 to 30 minutes) as well as the baseline IGF‐I levels, in a group of 44 PWS adults (18 males, 26 females) aged 18–41·1 years. The same protocol was carried out in a control group of 17 obese subjects (7 males, 10 females) aged 21·8–45·8 years.

Measurements Blood samples were taken at −15 and 0 minutes and then 30, 45, 60, 90 and 120 minutes after GHRH administration. Serum GH and total IGF‐I concentrations were measured by chemioluminescence. Statistical analysis was performed by Student'st‐test for unpaired data, and using analysis of variance for parametric and nonparametric (Mann–Whitney test) data, where appropriate. The relationship between pairs of variables was assessed by Pearson's correlation. Independent variables influencing GH secretion were tested by multiple linear regression analysis.

Results The GH response to GHRH + ARG was significantly lower in PWS patients (GH peak (mean ± SE) 8·4 ± 1·2 µg/l; AUC: 471·4 ± 77·8 µg/l/h) than obese subjects (GH peak 15·7 ± 2·9 µg/l,P < 0·02; AUC 956 ± 182·9 µg/l/h,P < 0·005). When considered individually, 17 of 44 PWS individuals (38·6%) were severely GHD, according to the cut‐off limit of 4·1 µg/l for obese individuals, and low IGF‐I‐values were present in 33 PWS patients. Moreover, impaired GH response was combined with subnormal IGF‐I levels in all PWS patients with GHD.

Conclusions Adult subjects with PWS had a reduced responsiveness to GHRH + ARG administration associated with reduced IGF‐I levels. In addition, a severe GHD for age was demonstrated in a significant percentage of PWS subjects. These findings are in agreement with the hypothesis that a complex derangement of hypothalamus‐pituitary axis occurred in PWS, and suggested that impaired GH secretion is not an artefact of obesity.
Effects of Cation Properties on Sol‐gel Transition and Gel Properties of κ‐carrageenan
Authors: Lai V.M.F. , Wong P.A.‐L. , Lii C.‐Y.
Published: July 2006

The phase transition temperatures, rheological properties and gel‐network characteristics for gelation of κ‐carrageenan‐salt (NaCl, KCl and CaCl2) solutions and their aged gels were investigated. The effectiveness of increasing gelling and gel‐melting temperatures at the salt concentrations examined followed the sequence of K+ > Ca2+ > Na+. This sequence was also true for the gel strength and the melting enthalpy (DH) of the most crosslinked junction zones of aged gels at low salt concentrations. Nonetheless, a different order (Ca++ > K+ and Na+) was found for increasing storage modulus and gelation rate during early‐stage gelation, thermal hysteresis and the DH of aged gels in some salt‐carrageenan systems.
Attachment and proliferation of human periodontal ligament fibroblasts on bioactive glass modified ceramics
Authors: KONTONASAKI E. , SIVROPOULOU A. , PAPADOPOULOU L. , GAREFIS P. , PARASKEVOPOULOS K. , KOIDIS P.
Published: July 2006

summary  In this study, six groups of modified ceramic specimens were constructed and were studied comparatively with dental porcelain (P:control) for their ability to support human periodontal ligament fibroblasts attachment and proliferation. The dental porcelain was initially coated with bioactive glass (PCB) or with a mixture of porcelain and bioactive glass (PCBP) and then calcium–phosphate rich (Ca–P) or hydroxy‐carbonate apatite (HCAp) layers were bio‐mimetically developed on both surfaces (PCB and PCBP) after immersion in simulated body fluid. The development and characterization of Ca–P and HCAp layers on PCBCa–P, PCBHCAp, PCBPCa–P, PCBPHCAp specimens’ surfaces were evaluated by Scanning Electron Microscopy (SEM) and further confirmed by Fourier Transform Infrared Spectroscopy (FTIR). The modified ceramics differed from their controls concerning their surface morphology as evaluated by SEM, and their surface chemical composition (Al, P, Si, Ca, Na and K) as evaluated by Energy Dispersive Spectroscopy (EDS). Almost all modified specimens supported cell attachment, spreading and proliferation at higher extent than the control porcelain specimens. The additional layers of Ca–P or HCAp on PCBP and PCB specimens were found to positively affect cell attachment and proliferation. The highest cell population, of all specimens tested, was observed on PCBPCa–P and PCBPHCAp. The Ca–P particles present on all Ca–P and HCAp coated specimens seemed to be involved in cell adhesion.
Viral kinetics in the treatment of chronic hepatitis C
Authors: Layden‐Almer Jennifer E. , Cotler Scott J. , Layden Thomas J.
Published: July 2006

Summary. Hepatitis C virus (HCV) is a major cause of chronic hepatitis and hepatic fibrosis, and chronic infection can frequently progress to cirrhosis, end‐stage liver disease and hepatocellular carcinoma. Treatment with pegylated interferons (INFs) plus ribavirin has been shown to be more effective than pegylated INFs alone or standard INFs with or without ribavirin. The early response of HCV to treatment with peg‐INF has been used to predict treatment outcomes in infected patients, emphasizing the importance of viral kinetics and genotyping in their treatment. Mathematic modelling of viral dynamics has shown the importance of optimal doses of drug, with early virologic response at week 12 predictive of sustained virologic response. Maintaining INF concentration above a therapeutically effective level is necessary to prevent viral rebound and subsequent treatment failure. Once‐weekly dosing with peg‐INF‐α2a, which has a longer half‐life than other forms of INF, plus daily dosing with ribavirin, has been shown to be effective in reducing viral load.
Metagenomic DNA fragments that affect Escherichia coli mutational pathways
Authors: Yang Hanjing , To Kam H. , Aguila Sharon J. , Miller Jeffrey H.
Published: July 2006

A multicopy cloning approach was used to search for metagenomic DNA fragments that affect Escherichia coli mutational pathways. Soil metagenomic expression libraries were constructed with DNA samples prepared directly from soil samples collected from the UCLA Botanical Garden. Using frameshift mutator screening, we obtained a total of 26 unique metagenomic fragments that stimulate frameshift rates in an E. coli wild‐type host. Mutational enhancer strains such as an ndk‐deficient strain and a temperature sensitive mutS strain (mutS60) were used to further verify the mutator phenotype. We found that the presence of multiple copies of certain types of metagenomic DNA sequence repeats cause general genome instability in the wild‐type E. coli host and the effect can be suppressed by overproducing a DNA mismatch component MutL. In addition, we identified nine metagenomic mutator genes (designated as smu genes) that encode proteins that have not been linked to mutator phenotypes prior to this study including a putative RNA methyltransferase Smu10A. The strain overproducing Smu10A displays one prominent base substitution hotspot in the rpoB gene, which coincides with the base substitution hotspot we have observed in cells that are partially deficient in the proofreading function carried out by the DNA polymerase III epsilon subunit. Based on the structural conservation of DNA replication/recombination/repair machineries among microorganisms, this approach would allow us to both identify new mutational pathways in E. coli and to find genes involved in DNA replication, recombination or DNA repair from vast unculturable microbes.
Embryo Production in Dogs: from In Vitro Fertilization to Cloning
Authors: Luvoni GC , Chigioni S , Beccaglia M
Published: July 2006

Contents

Increased availability of canine embryos would be desirable to develop research and to apply assisted reproductive technologies in the treatment of infertility and in the improvement of reproductive performances in valuable Canids, both domestic and non‐domestic. Embryo production through in vitro fertilization and nuclear transfer has been technically achieved in the dog, and the transfer of cloned embryos has recently resulted in the birth of puppies. However, the efficiency of these technologies is still very limited. This is mainly because of the peculiar characteristics of the canine oocyte and the lack of its full acquisition of developmental competence in vitro. This paper discusses the latest results and aspects on which further research should be focused to provide advances in the field.
Developments in European Horse Breeding and Consequences for Veterinarians in Equine Reproduction
Authors: Aurich J , Aurich C
Published: July 2006

Contents

The liberalization of European animal breeding legislation and an increasing diversity of equestrian sports have led to a constant rise in the number of horse breeds and breed registries. In addition to the trend towards more and smaller breed registries, there is another trend towards an international expansion of the bigger established sport horse breeds. Regional breeds, at least in smaller countries, may no longer be able to run an independent breeding programme. The typical horse breeder, in the future, will be a female and qualified in equestrian sports. Artificial insemination (AI) mainly with fresh or cooled‐transported semen has become a major breeding tool, allowing breeders all over Europe to benefit from the best stallions of most breeds. New AI techniques such as low‐dose insemination may remain restricted to individual stallions and also the interest of breeding programmes in sex determination of foals via semen sorting is limited. Embryo transfer and associated techniques, although allowed by most breeds, have not contributed significantly to genetic progress in European sport horses so far. A potential use of cloning may be to produce gonad‐intact copies from geldings that have performed to a superior level. With a more open and international structure of horse breeding and increased use of AI, equine reproduction and biotechnology should be emphasized by veterinary curricula and continuing professional education programmes.
Biosecurity and the Various Types of Embryos Transferred
Authors: Thibier M
Published: July 2006

Contents

The aim of the present paper was to review some features related to the risk analysis of three types of embryos to be transferred, namely the in vivo derived, the in vitro produced and the cloned ones. For in vivo‐collected embryos, a considerable number of experiments and scientific investigations have been performed and hundreds of thousands of embryos are transferred annually with no contamination of associated diseases. Provided that the code of practice such as that published by the International Embryo Transfer Society is strictly followed by the embryo transfer practitioners, the statement made some 17 years ago saying that the in vivo‐derived embryo transfer was the safest way of exchanging genes remains entirely true, thanks to the professionalism of the embryo transfer industry. For the in vitro‐produced embryos, some particular rules have to be followed because of specific risks for some pathogens to strongly adhere to the zona pellucida of such embryos. There are some means to monitor and control those effects, and the transfer of in vitro‐produced embryos can also be a very safe way to exchange genes around the world. The third type of embryos, the cloned ones, is a quite different category and the risk analysis to be soundly made still needs a lot of investigations so as to characterize the potential risks if there are, in terms not only of disease transmission but also in terms of public health, zoonotic risks as well as those related to quality and safety of food. The problem in this regard, is more directly addressed for offspring of clones than to the cloned embryos themselves. Published data on this issue are increasing in numbers so that progress in that area is expected in the few years to come.
L‐carnitine ameliorates doxorubicin‐induced nephrotic syndrome in rats
Authors: BOONSANIT DOLRUDEE , KANCHANAPANGKA SUMOLAYA , BURANAKARL CHOLLADA
Published: July 2006

Aim:  Effects of L‐carnitine on nephrotoxicity and oxidative stress induced by doxorubicin (DOX) in rats were investigated.

Methods:  The rats were divided into four groups: group 1, control (0.9% NaCl); group 2, DOX injection (7.5 mg/kg, i.v.); group 3, DOX plus low dose (40 mg/kg) L‐carnitine; and group 4, DOX plus high dose (200 mg/kg) L‐carnitine. L‐carnitine was administered 1 h before doxorubicin injection and daily thereafter for 15 days.

Results:  Rats in group 2 were associated with hypoalbuminaemia, hyperlipidaemia, high urinary excretion of protein and elevated plasma creatinine and urea nitrogen. The glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) decreased with increased renal vascular resistance (RVR). Kidney catalase (CAT) activity was decreased. In group 3 and 4, plasma triglyceride and cholesterol declined. L‐carnitine improved renal functions by elevated GFR and ERPF and decreased plasma creatinine and urea nitrogen. The kidney CAT activity were increased significantly compared with group 2. From histopathological results, group 2 rats were found to have glomerular capillary dilation and tubular dilation. The lesions were less in group 3 and 4 rats.

Conclusion:  L‐carnitine can protect renal impairment functionally, biochemically and histopathologically with a corresponding reduction of oxidative stress.
Review of Epstein–Barr virus and post‐transplant lymphoproliferative disorder post‐solid organ transplantation (Review Article)
Authors: LIM WAI H , RUSS GRAEME R , COATES PATRICK TH
Published: July 2006

SUMMARY:  Post‐transplant lymphoproliferative disorder (PTLD) following solid organ transplantation is an important form of post‐transplant malignancy. PTLD is typically associated with Epstein–Barr virus (EBV) and occurs in the setting of profound immunosuppression resulting in a deficiency of EBV‐specific cytotoxic T lymphocytes (CTL). Predisposing factors include EBV mismatch between donor and recipient, use of immunosuppression especially T‐cell depletive therapies and genetic predisposition of recipients. The standard approach has been to reduce immunosuppression but is often insufficient to induce tumour regression. Further understanding of the immunobiology of PTLD has resulted in improved monitoring techniques (including EBV viral load determined by polymerase chain reaction) and newer treatment options. Recent work has highlighted a potential role for dendritic cells in both the pathogenesis and treatment of PTLD. Current treatment modalities include adoptive immunotherapy using ex vivo generated autologous EBV‐specific CTL or allogeneic CTL, cytokine therapies, antiviral agents, and more recently, rituximab and dendritic‐cell based therapies. This review focuses on the developments and progress in the pathogenesis, diagnosis and treatment of PTLD.
Rapid estimation of microbial numbers in water using bulk fluorescence
Authors: Wegley Linda , Mosier‐Boss Pamela , Lieberman Stephen , Andrews John , Graff‐Baker Amanda , Rohwer Forest
Published: July 2006

Enumeration of microbial cells without culturing is an essential technique for microbial ecology and water quality evaluation. Here we show that bulk fluorescence using the SYBR Gold DNA stain can be used to rapidly quantify microbial cells per millilitre in fresh, marine and estuarine waters. The bulk fluorescence method is comparable to estimating cell concentrations in cultures using optical density; however, this enhanced method enables the user to estimate microbial numbers at lower concentration (> 105 cells ml−1) found in environmental samples. The technique worked in both single‐cell and 96‐well plate fluorescent spectrophotometers. Differences of ∼105 cells per millilitre were discernible and the precision of the bulk fluorescence was higher than direct counting by epifluorescent microscopy. Treatment with DNase I increased sensitivity by lowering background noise attributed to free DNA. This technique is simple, rapid, inexpensive and adaptable for automatically estimating microbial numbers in water samples.
Pollen‐mediated gene flow in maize in real situations of coexistence
Authors: Messeguer Joaquima , Peñas Gisela , Ballester Jordi , Bas Marta , Serra Joan , Salvia Jordi , Palaudelmàs Montserrat , Melé Enric
Published: July 2006

We present the first study on cross‐fertilization between Bt and conventional maize in real situations of coexistence in two regions in which Bt and conventional maize were cultivated. A map was designed and the different crops were identified, as were the sowing and flowering dates, in Bt and conventional maize fields. These data were used to choose the non‐transgenic fields for sampling and analysis by the real‐time quantification system‐polymerase chain reaction (RTQ‐PCR) technique. In general, the rate of cross‐fertilization was higher in the borders and, in most of the fields, decreased towards the centre of the field. Nine fields had values of genetically modified organism DNA to total DNA of much lower than 0.9%, whereas in three the rate was higher. Some differences were found when comparing our results with those of common field trials. In real conditions of coexistence and in cropping areas with smaller fields, the main factors that determined cross‐pollination were the synchronicity of flowering and the distances between the donor and receptor fields. By establishing an index based on these two variables, the rate of the adventitious presence of genetically modified maize could be predicted, as well as the influence of other factors. By applying this index, and in the case of a fully synchronous flowering time, a security distance between transgenic and conventional fields of about 20 m should be sufficient to maintain the adventitious presence of genetically modified organisms as a result of pollen flow below the 0.9% threshold in the total yield of the field.
Growth, Poverty Reduction and Development Assistance in Asia: Options and Prospects
Authors: Farrington John , Clarke Jeremy
Published: July 2006

This article examines a number of policy challenges and dilemmas arising from the pattern of growth and poverty reduction in Asia, central to which is the fact that growth and poverty reduction have been more rapid in Asia than in any other region in the last decade, and yet Asia still contains the majority of the world's poor. The article examines the record of achievement, possible future trends including emerging patterns of inequality, and likely future priorities for poverty‐reduction policies. It assesses the role of official development assistance and suggests how it may evolve in future, in part linked with responses to a number of challenges shared between Asian and OECD countries, including energy supply, environmental issues including climate change, and financial stability.
Children's Moral Reasoning Regarding Physical and Relational Aggression
Authors: Murray‐Close Dianna , Crick Nicki R. , Galotti Kathleen M.
Published: July 2006

Elementary school children's moral reasoning concerning physical and relational aggression was explored. Fourth and fifth graders rated physical aggression as more wrong and harmful than relational aggression but tended to adopt a moral orientation about both forms of aggression. Gender differences in moral judgments of aggression were observed, with girls rating physical and relational aggression as more wrong and relational aggression as more harmful than boys. In addition, girls were more likely to adopt a moral orientation when judging physical and relational aggression and girls more often judged relational aggression than physical aggression from the moral domain. Finally, moral reasoning about aggression was associated with physically and relationally aggressive behavior. Considered together, the results indicate that children tend to adopt a moral orientation about aggression, but that they nonetheless differentiate between physical and relational aggression in their moral judgments.
The Prevention of Social Aggression Among Girls
Authors: Cappella Elise , Weinstein Rhona
Published: July 2006

This study represents the first systematic attempt to examine a theory‐based program designed to reduce girls' social aggression and increase positive leadership among peers. Fifth‐grade girls from six public schools were randomly assigned within classrooms to the social aggression prevention program (SAPP) and the comparison reading clubs. A school‐based small group program, the SAPP was demonstrated to have a positive impact for all students in the domain of social problem solving. For students with high baseline social problems, teachers reported positive changes in SAPP participants' prosocial behavior. In addition, the content of the program was critical: reading club participants improved their reading achievement at greater rates than SAPP participants. Targeting female students in a program focused on resolving social conflicts from multiple perspectives may be an important addition to broader, multilevel initiatives to prevent aggression and promote leadership in schools.
Adolescent Perceptions of Appropriate Parental Reactions in Moral and Conventional Social Domains
Authors: Padilla‐Walker Laura M. , Carlo Gustavo
Published: July 2006

Research suggests that adolescents' ratings of the appropriateness of parental reactions are influenced by several constructs, including adolescents' perceptions of the type of parental reaction, the emotions felt by the adolescent and parental intentions. However, little is known regarding how these constructs are differentially predictive of appropriateness in different socialization contexts. One hundred and twenty‐two adolescents (mean age = 16.87 years) answered questions regarding past situations in antisocial and prosocial contexts, and in moral and conventional domains. Different parental reactions were reported across moral and conventional domains. In addition, the appropriateness of parental responses varied across domain. Namely, in antisocial contexts, parental responses of yelling and punishing were seen as more appropriate in moral than conventional domains. In prosocial contexts, no action from the parent was seen as less appropriate in conventional than moral domains. In addition, adolescents' perceptions were more strongly associated with adolescents' ratings of appropriateness in conventional than moral social domains. These findings highlight the importance of considering both moral context and social domain when examining adolescents' perceptions of appropriate parental reactions and internalization of values.
Taiwanese–Canadian Mothers’ Beliefs About Personal Freedom for Their Young Children
Authors: Chuang Susan S.
Published: July 2006

This study examined Taiwanese–Canadian mothers’ conceptions of personal freedom in everyday situations for their children and the influence of acculturation on their beliefs. Forty mothers of six‐ to eight‐year‐old children participated in a semistructured interview and sorting task. Interview responses revealed that, regardless of acculturation, child decision‐making was important and that mothers should negotiate and compromise with their child on everyday issues such as clothing, food, activities, daily routine and homework. They believed that child resistance was motivated by the children's personal interests, laziness, limit testing and their emotional state. Sources of conflict were resolved by parental authority, discussing/negotiating and conceding to the child. The sorting task also revealed that personal issues were judged as within their children's jurisdiction.
Migraine in the Elderly: A Comparison With Migraine in Young Adults
Authors: Martins Kátia M. , Bordini Carlos A. , Bigal Marcelo E. , Speciali José G.
Published: July 2006

Objective.—In this study we compare the clinical features of migraine attacks occurring in the elderly (60 to 70 years) and in younger migraineurs (20 to 40 years).

Background.—Studies comparing the clinical features of migraine at different ages are still lacking. These studies are important for a better comprehension of the natural history of migraine, as well as to refine our recognition of the disease.

Methods.—We retrospectively assessed subjects seen from 1995 to 2000 in a university‐based outpatient headache clinic in Brazil. We reviewed 144 charts from patients 60 to 70 years (mean = 66.4). We applied a questionnaire based on the first edition of the International Classification of Headache Disorders (criteria for episodic migraine remained unchanged in the second edition). Controls were migraineurs from 20 to 40 years (mean = 32.6).

Results.—Migraine occurred in 25% of the elderly and 29% of younger migraineurs (NS). A lower proportion of migraine attacks in the elderly were unilateral (38% vs. 57%, P < .01), or with associated symptoms (nausea = 75% vs. 86%, P= .05; vomiting = 30% vs. 54%, P < .05, photophobia and phonophobia = 83% vs. 94%, P < .05). Other symptoms such as paleness (P= .0441), dry mouth (P= .0093), and anorexia (P= .05) were more common in the elderly.

Conclusion.—Migraine is less typical in the elderly and more frequently associated with vegetative symptoms. Therefore, the diagnosis of migraine in elderly subjects may be more challenging, and many seniors with this primary headache can be misdiagnosed.
WITNESSING IN THE CLASSROOM: THE ETHICS AND POLITICS OF AFFECT
Authors: Zembylas Michalinos
Published: July 2006

Abstract In this essay, Michalinos Zembylas explores the meaning of affect and its importance to educational efforts to create the classroom conditions necessary for students and teachers to become critical witnesses to trauma and oppression. Zembylas draws out some of the ethical and political possibilities that emerge through such efforts, and extends our thinking about the affective possibilities of witnessing. His aims are threefold: (1) to discuss the nature of affect and the affective economies of witnessing; (2) to show some of the ways in which classrooms and affect interact to produce a particular politics and ethics, especially in contexts of historical trauma; and (3) to provide a sketch of how progressive pedagogies based on witnessing can educate toward an understanding of affect that may encourage a transformative political response.
European Agriculture in the Wake of Globalisation: What are the Prospects for its Diversity?
Authors: Seehofer Horst
Published: July 2006

The multifunctional European agricultural sector has not lost any of its significance for our society and our rural areas. Five building blocks and fields of action are of particular importance for the future: (1) Fulfilling our political responsibility in the current WTO negotiations, not only in economic, but also in social and ecological terms; (2) Recognising new opportunities and tapping into potential with foresight, potential which is currently becoming particularly apparent in the case of renewable resources; (3) Continuing to focus on the great strengths of the European agricultural sector: the long‐term stability of our economic system, large market outlets virtually on our doorstep, high qualification and training levels, modern and efficient agricultural research systems and upstream and downstream industries, along with the wide variety of high‐quality products and regional diversity; (4) Eliminating existing weaknesses, in particular by reducing bureaucratic obstacles; and (5) Early detection of threats and ensuring robustness and stability in European agri‐food systems through development of adequate prevention and crisis response mechanisms. In this way, the ‘European agricultural model’ will become a motor for future development. After all, the multifaceted European agricultural sector can trigger and promote regional growth.
EU and US Regulations for Handling and Transporting Genetically Modified Grains: Are Both Positions Correct?
Authors: Lence Sergio H. , Hayes Dermot J.
Published: July 2006

Differences in the way GM grains are treated in the US and the EU motivate the question of whether there is a single correct policy towards identification of such products. This issue is addressed here, based on a mathematical model that assumes that the cost of maintaining identity on non‐GM markets is borne by the non‐GM industry. The economic welfare impacts of introducing GM technology depend on the levels of consumer concern and production cost savings, and the cost of maintaining non‐GM grain identity. The introduction of a new cost‐reducing GM technology often increases total welfare as one might expect. However, society loses when GM production cost‐savings are small and consumers are highly concerned about GM grain because introducing GM technology creates a need to preserve the identity of non‐GM grain. Taken together, the results suggest that the US may have maximized welfare by not requiring labeling of GM corn and soybeans, and that the recently approved EU legislation enforcing labeling of GM crops also makes sense in the EU. The reason for this is that consumer concern in the EU appears to be greater than in the US, and fewer EU producers stand to benefit from cost savings in GM corn and soybean production.