bluuebunny/crossref_metadata_2025 huggingface dataset:
Delayed Computed Tomography Arthrography of Human Knee Cartilage In Vivo
Authors: Kokkonen Harri T. , Aula Antti S. , Kröger Heikki , Suomalainen Juha-Sampo , Lammentausta Eveliina , Mervaala Esa , Jurvelin Jukka S. , Töyräs Juha
Published: May 2012

Objective:

We investigated the feasibility of delayed computed tomography (CT) arthrography for evaluation of human knee cartilage in vivo. Especially, the diffusion of contrast agent out of the joint space and the optimal time points for imaging were determined.

Design:

Two patients were imaged using delayed CT arthrography and delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) techniques.

Results:

Two hours after injection, the concentration of contrast agent in the joint space was still high enough (20% to 24.5% of the initial concentration at 0 minutes) to allow delayed CT arthrography. The half-life of the contrast agent in the joint space varied from 30 to 60 minutes. The contrast agent concentration in patellar and femoral cartilage reached the maximum after 30 and 60 minutes, respectively. According to dGEMRIC, there were no differences between patients. However, in delayed CT arthrography, the penetration of the contrast agent was higher in the osteoarthritic knee cartilage.

Conclusions:

Contrast agent remained in the joint space long enough to enable delayed CT arthrography of cartilage. After 30 minutes, the normalized contrast agent concentration was higher in the cartilage of the osteoarthritic knee in comparison with the healthy knee. To conclude, delayed CT arthrography exhibited potential for use in the clinical evaluation of cartilage integrity.
Genome-wide recruitment to Polycomb-modified chromatin and activity regulation of the synovial sarcoma oncogene SYT-SSX2
Authors: Garcia Christina B , Shaffer Christian M , Eid Josiane E
Published: May 2012

Background

SYT-SSX is the oncogene associated with synovial sarcoma (SS), a stem cell disease. SYT-SSX is thought to be responsible for sarcoma initiation and development. It interacts with components of Polycomb and SWI/SNF complexes, the two epigenetic controllers that maintain the heritable status of differentiation-specific genes in the stem/progenitor cell. Through these associations SYT-SSX is thought to alter gene expression programs by epigenetic mechanisms. Recently, we reported that SYT-SSX2 reprograms mesenchymal stem cells and myoblasts by dictating their commitment to the neural lineage while disrupting their normal differentiation. This reprogramming was due to the direct occupancy of proneural genes by the SYT-SSX2 nuclear complex. To gain a clear understanding of SYT-SSX2 control of gene expression networks, we conducted a thorough genome-wide analysis to determine the mechanism of its recruitment and identify signature sets of epigenetic markers that would predict its targeting and transcriptional activity.

Results

SYT-SSX2 was recruited to distinct loci across all chromosomes, and an overwhelming number of Polycomb-modified sites enriched with the trimethylated histone H3 on lysine 27 (H3K27me3) formed the main recruiting module for SYT-SSX2. Not all SYT-SSX2/H3K27me3-occupied genes had altered expression, denoting the requirement for additional signals upon oncogene binding. Differential binding and epigenetic patterns distinguished upregulated and downregulated genes. Most activated genes had SYT-SSX2 sites enriched with H3K27me3 within their body or near their transcription start site (TSS) whereas a majority of downregulated genes were characterized by SYT-SSX2/H3K27me3-rich regions at long-range, or by modifications associated with transcription activation within the gene body or near the TSS. Hierarchical and functional clustering identified H3K27me3 as the dominant epigenetic marker associated with SYT-SSX2 binding and gene expression. Notably, this analysis revealed a cluster of upregulated neuronal genes densely covered by H3K27me3, consistent with programming toward the neural lineage by SYT-SSX2 observed previously.

Conclusions

The data analysis revealed that Polycomb complexes or their modified chromatin and their stably silenced differentiation programs seem to be the main target for SYT-SSX2, suggesting that their perturbation is at the center of tumorigenesis driven by the oncogene. Further research into this mechanism is crucial to the full understanding of SS biology.
Comparison of low and high dose ionising radiation using topological analysis of gene coexpression networks
Authors: Ray Monika , Yunis Reem , Chen Xiucui , Rocke David M
Published: May 2012

Background

The growing use of imaging procedures in medicine has raised concerns about exposure to low-dose ionising radiation (LDIR). While the disastrous effects of high dose ionising radiation (HDIR) is well documented, the detrimental effects of LDIR is not well understood and has been a topic of much debate. Since little is known about the effects of LDIR, various kinds of wet-lab and computational analyses are required to advance knowledge in this domain. In this paper we carry out an “upside-down pyramid” form of systems biology analysis of microarray data. We characterised the global genomic response following 10 cGy (low dose) and 100 cGy (high dose) doses of X-ray ionising radiation at four time points by analysing the topology of gene coexpression networks. This study includes a rich experimental design and state-of-the-art computational systems biology methods of analysis to study the differences in the transcriptional response of skin cells exposed to low and high doses of radiation.

Results

Using this method we found important genes that have been linked to immune response, cell survival and apoptosis. Furthermore, we also were able to identify genes such as BRCA1, ABCA1, TNFRSF1B, MLLT11 that have been associated with various types of cancers. We were also able to detect many genes known to be associated with various medical conditions.

Conclusions

Our method of applying network topological differences can aid in identifying the differences among similar (eg: radiation effect) yet very different biological conditions (eg: different dose and time) to generate testable hypotheses. This is the first study where a network level analysis was performed across two different radiation doses at various time points, thereby illustrating changes in the cellular response over time.
Quantitative analysis of organelle distribution and dynamics in Physcomitrella patens protonemal cells
Authors: Furt Fabienne , Lemoi Kyle , Tüzel Erkan , Vidali Luis
Published: May 2012

Background

In the last decade, the moss Physcomitrella patens has emerged as a powerful plant model system, amenable for genetic manipulations not possible in any other plant. This moss is particularly well suited for plant polarized cell growth studies, as in its protonemal phase, expansion is restricted to the tip of its cells. Based on pollen tube and root hair studies, it is well known that tip growth requires active secretion and high polarization of the cellular components. However, such information is still missing in Physcomitrella patens. To gain insight into the mechanisms underlying the participation of organelle organization in tip growth, it is essential to determine the distribution and the dynamics of the organelles in moss cells.

Results

We used fluorescent protein fusions to visualize and track Golgi dictyosomes, mitochondria, and peroxisomes in live protonemal cells. We also visualized and tracked chloroplasts based on chlorophyll auto-fluorescence. We showed that in protonemata all four organelles are distributed in a gradient from the tip of the apical cell to the base of the sub-apical cell. For example, the density of Golgi dictyosomes is 4.7 and 3.4 times higher at the tip than at the base in caulonemata and chloronemata respectively. While Golgi stacks are concentrated at the extreme tip of the caulonemata, chloroplasts and peroxisomes are totally excluded. Interestingly, caulonemata, which grow faster than chloronemata, also contain significantly more Golgi dictyosomes and fewer chloroplasts than chloronemata. Moreover, the motility analysis revealed that organelles in protonemata move with low persistency and average instantaneous speeds ranging from 29 to 75 nm/s, which are at least three orders of magnitude slower than those of pollen tube or root hair organelles.

Conclusions

To our knowledge, this study reports the first quantitative analysis of organelles in Physcomitrella patens and will make possible comparisons of the distribution and dynamics of organelles from different tip growing plant cells, thus enhancing our understanding of the mechanisms of plant polarized cell growth.
Absence of Helicobacter pylori high tetracycline resistant 16S rDNA AGA926-928TTC genotype in gastric biopsy specimens from dyspeptic patients of a city in the interior of São Paulo, Brazil
Authors: Suzuki Rodrigo Buzinaro , Almeida Cristiane Maria , Sperança Márcia Aparecida
Published: May 2012

Background

Treatment effectiveness of Helicobacter pylori varies regionally and is decreasing worldwide, principally as a result of antibiotic resistant bacterium. Tetracycline is generally included in second line H. pylori eradication regimens. In Brazil, a high level of tetracycline resistance (TetR) is mainly associated with AGA926-928TTC 16 S rDNA nucleotide substitutions. As H. pylori culture is fastidious, we investigated the primary occurrence of H. pylori 16 S rDNA high level TetR genotype using a molecular approach directly on gastric biopsies of dyspeptic patients attending consecutively at Hospital das Clinicas of Marilia, São Paulo, Brazil.

Methods

Gastric biopsy specimens of 68 peptic ulcer disease (PUD) and 327 chronic gastritis (CG) patients with a positive histological diagnosis of H. pylori were investigated for TetR 16 S rDNA genotype through a molecular assay based on amplification of a 16 S rDNA 545 bp fragment by polymerase chain reaction and HinfI restriction fragment length polymorphism (PCR/RFLP). Through this assay, AGA926-928TTC 16 S rDNA TetR genotype resulted in a three DNA fragment restriction pattern (281, 227 and 37 bp) and its absence originated two DNA fragments (264 and 281 bp) due to a 16 S rDNA conserved Hinf I restriction site.

Results

The 545 bp 16 S rDNA PCR fragment was amplified from 90% of gastric biopsies from histological H. pylori positive patients. HinfI RFLP revealed absence of the AGA926–928TTC H. pylori genotype and PCR products of two patients showed absence of the conserved 16 S rDNA HinfI restriction site. BLASTN sequence analysis of four amplicons (two conserved and two with an unpredicted HinfI restriction pattern) revealed a 99% homology to H. pylori 16 S rDNA from African, North and South American bacterial isolates. A nucleotide substitution abolished the conserved HinfI restriction site in the two PCR fragments with unpredicted HinfI RFLP, resulting in an EcoRI restriction site.

Conclusions

H. pylori AGA926-928TTC 16 S rDNA gene substitutions were not found in our population. More research is required to investigate if H. pylori TetR has a different genetic background in our region and if the nucleotide substitutions of the uncultured H. pylori 16 S rRNA partial sequences have biological significance.
Evaluation of a hand-held far-ultraviolet radiation device for decontamination of Clostridium difficile and other healthcare-associated pathogens
Authors: Nerandzic Michelle M , Cadnum Jennifer L , Eckart Kevin E , Donskey Curtis J
Published: May 2012

Background

Environmental surfaces play an important role in transmission of healthcare-associated pathogens. There is a need for new disinfection methods that are effective against Clostridium difficile spores, but also safe and rapid. The Sterilray™ Disinfection Wand device is a hand-held room decontamination technology that utilizes far-ultraviolet radiation (185-230 nm) to kill pathogens.

Methods

We examined the efficacy of disinfection using the Sterilray device in the laboratory, in rooms of hospitalized patients, and on surfaces outside of patient rooms (i.e. keyboards and portable medical equipment). Cultures for C. difficile, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococcus (VRE) were collected from commonly-touched surfaces before and after use of the Sterilray device.

Results

On inoculated surfaces in the laboratory, application of the Sterilray device at a radiant dose of 100 mJ/cm2 for ~ 5 seconds consistently reduced recovery of C. difficile spores by 4.4 CFU log10, MRSA by 5.4 log10CFU and of VRE by 6.9 log10CFU. A >3 log10 reduction of MRSA and VRE was achieved in ~2 seconds at a lower radiant dose, but killing of C. difficile spores was significantly reduced. On keyboards and portable medical equipment that were inoculated with C. difficile spores, application of the Sterilray device at a radiant dose of 100 mJ/cm2 for ~ 5 seconds reduced contamination by 3.2 log10CFU. However, the presence of organic material reduced the lethal effect of the far-UV radiation. In hospital rooms that were not pre-cleaned, disinfection with the Sterilray device significantly reduced the frequency of positive C. difficile and MRSA cultures (P =0.007).

Conclusions

The Sterilray™ Disinfection Wand is a novel environmental disinfection technology that rapidly kills C. difficile spores and other healthcare-associated pathogens on surfaces. However, the presence of organic matter reduces the efficacy of far-UV radiation, possibly explaining the more modest results observed on surfaces in hospital rooms that were not pre-cleaned.
Ethics, patient rights and staff attitudes in Shanghai's psychiatric hospitals
Authors: Su Liang , Huang Jingjing , Yang Weimin , Li Huafang , Shen Yifeng , Xu Yifeng
Published: May 2012

Background

Adherence to ethical principles in clinical research and practice is becoming topical issue in China, where the prevalence of mental illness is rising, but treatment facilities remain underdeveloped. This paper reports on a study aiming to understand the ethical knowledge and attitudes of Chinese mental health professionals in relation to the process of diagnosis and treatment, informed consent, and privacy protection in clinical trials.

Methods

A self-administered survey was completed by 1110 medical staff recruited from Shanghai’s 22 psychiatric hospitals. Simple random selection methods were used to identify target individuals from the computerized registry of staff.

Results

The final sample for analysis consisted 1094 medical staff (including 523 doctors, 542 nurses, 8 pharmacologists and 21 other staff). The majority reported that their medical institutions had not established an Ethics Committee (87.8%) and agreed that Ethics Committees should be set up in their institutions (72.9%). Approximately half (52%) had not received systematic education in ethics, and almost all (89.1%) of the staff thought it was necessary. Nearly all participants (90.0%) knew the Shanghai Mental Health Regulations which was the first local regulations relating to mental health in China, but only 11% and 16.6% respectively knew of the Nuremberg Code and the Declaration of Helsinki. About half (51.8%) thought that the guardian should make the decision as to whether the patient participated in clinical trials or not.

Conclusions

The study indicates that most psychiatric hospitals in Shanghai have no Medical Ethics Committee. More than half the medical staff had not received systematic education and training in medical ethics and they have insufficient knowledge of the ethical issues related to clinical practice and trials. Training in ethics is recommended for medical staff during their training and as ongoing professional development.
Comparative effect of angiotensin II type I receptor blockers and calcium channel blockers on laboratory parameters in hypertensive patients with type 2 diabetes
Authors: Nishida Yayoi , Takahashi Yasuo , Nakayama Tomohiro , Asai Satoshi
Published: May 2012

Background

Both angiotensin II type I receptor blockers (ARBs) and calcium channel blockers (CCBs) are widely used antihypertensive drugs. Many clinical studies have demonstrated and compared the organ-protection effects and adverse events of these drugs. However, few large-scale studies have focused on the effect of these drugs as monotherapy on laboratory parameters. We evaluated and compared the effects of ARB and CCB monotherapy on clinical laboratory parameters in patients with concomitant hypertension and type 2 diabetes mellitus.

Methods

We used data from the Clinical Data Warehouse of Nihon University School of Medicine obtained between Nov 1, 2004 and July 31, 2011, to identify cohorts of new ARB users (n = 601) and propensity-score matched new CCB users (n = 601), with concomitant mild to moderate hypertension and type 2 diabetes mellitus. We used a multivariate-adjusted regression model to adjust for differences between ARB and CCB users, and compared laboratory parameters including serum levels of triglyceride (TG), total cholesterol (TC), non-fasting blood glucose, hemoglobin A1c (HbA1c), sodium, potassium, creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), hemoglobin and hematocrit, and white blood cell (WBC), red blood cell (RBC) and platelet (PLT) counts up to 12 months after the start of ARB or CCB monotherapy.

Results

We found a significant reduction of serum TC, HbA1c, hemoglobin and hematocrit and RBC count and a significant increase of serum potassium in ARB users, and a reduction of serum TC and hemoglobin in CCB users, from the baseline period to the exposure period. The reductions of RBC count, hemoglobin and hematocrit in ARB users were significantly greater than those in CCB users. The increase of serum potassium in ARB users was significantly greater than that in CCB users.

Conclusions

Our study suggested that hematological adverse effects and electrolyte imbalance are greater with ARB monotherapy than with CCB monotherapy.
Transcript and protein expression profile of PF11_0394, a Plasmodium falciparum protein expressed in salivary gland sporozoites
Authors: Schlarman Maggie S , Roberts Renee N , Kariuki Michael M , LaCrue Alexis N , Ou Ruguang , Beerntsen Brenda T
Published: May 2012

Background

Plasmodium falciparum malaria is a significant problem around the world today, thus there is still a need for new control methods to be developed. Because the sporozoite displays dual infectivity for both the mosquito salivary glands and vertebrate host tissue, it is a good target for vaccine development.

Methods

The P. falciparum gene, PF11_0394, was chosen as a candidate for study due to its potential role in the invasion of host tissues. This gene, which was selected using a data mining approach from PlasmoDB, is expressed both at the transcriptional and protein levels in sporozoites and likely encodes a putative surface protein. Using reverse transcription-polymerase chain reaction (RT-PCR) and green fluorescent protein (GFP)-trafficking studies, a transcript and protein expression profile of PF11_0394 was determined.

Results

The PF11_0394 protein has orthologs in other Plasmodium species and Apicomplexans, but none outside of the group Apicomplexa. PF11_0394 transcript was found to be present during both the sporozoite and erythrocytic stages of the parasite life cycle, but no transcript was detected during axenic exoerythrocytic stages. Despite the presence of transcript throughout several life cycle stages, the PF11_0394 protein was only detected in salivary gland sporozoites.

Conclusions

PF11_0394 appears to be a protein uniquely detected in salivary gland sporozoites. Even though a specific function of PF11_0394 has not been determined in P. falciparum biology, it could be another candidate for a new vaccine.
A new approach for cytokinin isolation from Arabidopsis tissues using miniaturized purification: pipette tip solid-phase extraction
Authors: Svačinová Jana , Novák Ondřej , Plačková Lenka , Lenobel René , Holík Josef , Strnad Miroslav , Doležal Karel
Published: May 2012

Background

We have developed a new analytical approach for isolation and quantification of cytokinins (CK) in minute amounts of fresh plant material, which combines a simple one-step purification with ultra-high performance liquid chromatography–fast scanning tandem mass spectrometry.

Results

Plant tissue samples (1–5 mg FW) were purified by stop-and-go-microextraction (StageTip purification), which previously has only been applied for clean-up and pre-concentration of peptides. We found that a combination of two reverse phases and one cation-exchange phase, was the best tool, giving a total extraction recovery higher than 80%. The process was completed by a single chromatographic analysis of a wide range of naturally occurring cytokinins (bases, ribosides, O- and N-glucosides, and nucleotides) in 24.5 minutes using an analytical column packed with sub-2-microne particles. In multiple reaction monitoring mode, the detection limits ranged from 0.05 to 5 fmol and the linear ranges for most cytokinins were at least five orders of magnitude. The StageTip purification was validated and optimized using samples of Arabidopsis thaliana seedlings, roots and shoots where eighteen cytokinins were successfully determined.

Conclusions

The combination of microextraction with one-step high-throughput purification provides fast, effective and cheap sample preparation prior to qualitative and quantitative measurements. Our procedure can be used after modification also for other phytohormones, depending on selectivity, affinity and capacity of the selected sorbents.
Novel therapeutic agents for cutaneous T-Cell lymphoma
Authors: Jain Salvia , Zain Jasmine , O’Connor Owen
Published: May 2012

Mycosis fungoides (MF) and Sezary Syndrome (SS) represent the most common subtypes of primary Cutaneous T-cell lymphoma (CTCL). Patients with advanced MF and SS have a poor prognosis leading to an interest in the development of new therapies with targeted mechanisms of action and acceptable safety profiles. In this review we focus on such novel strategies that have changed the treatment paradigm of this rare malignancy.
The effect of health education intervention on the home management of malaria among the caregivers of children aged under 5 years in Ogun State, Nigeria
Authors: Fatungase Kehinde O , Amoran Olorunfemi E , Alausa Kabir O
Published: May 2012

Background

Malaria is currently the most important cause of death and disability in children aged under 5 years in Africa. A health education interventional study of this nature is essential in primary control of an endemic communicable disease such as malaria. This study was therefore designed to determine the effect of health education on the home management of Malaria among the caregivers of children under 5 years old in Ogun State, Nigeria.

Methods

The study design was a quasi-experimental study carried out in Ijebu North Local Government Area of Ogun State. A multistage random sampling technique was used in choosing the required samples for this study and a semi-structured questionnaire was used to collect relevant information. The intervention consisted of a structured educational program based on a course content adapted from the national malaria control program. A total of 400 respondents were recruited into the study, with 200 each in both the experimental and control groups, and were followed up for a period of 3 months when the knowledge and uptake of insecticide treated net was reassessed.

Results

There was no statistically significant differences observed between the experimental and control groups in terms of sociodemographic characteristics such as age (P = 0.99), marital status (P = 0.48), religion (P = 0.1), and income (P = 0.51). The majority in both the experimental (75.0%) and control (71.5%) groups use arthemisinin-based combination therapy as first line home treatment drugs pre intervention. Post health education intervention, the degree of change in the knowledge of referral signs and symptoms in the experimental group was 52.8% (P < 0.0001) while it was 0.2% in the control group (P = 0.93). Tepid sponging improved by 45.0%, paracetamol use by 55.3%, and the use of herbs and other drugs were not significantly influenced in the experimental (P = 0.65 and 0.99) and control group (P = 0.89 and 0.88), respectively. Furthermore, there was a 55.7% (P = 0.001) increase in the proportion of respondents using the correct dose of arthemisinin-based combination therapy in the home management of malaria and 23.9% (P < 0.001) in the proportion using it for the required time.

Conclusions

The study concludes that there is a shift in the home management of malaria with the use of current and effective antimalarial drugs. It also demonstrated the effect of health education on the promptness of appropriate actions taken among the respondents for early diagnosis and treatment. Early diagnosis and appropriate treatment can be guaranteed if caregivers are knowledgeable on prompt actions to be taken in the home management of malaria.
Screening the human exome: a comparison of whole genome and whole transcriptome sequencing
Authors: Cirulli Elizabeth T , Singh Abanish , Shianna Kevin V , Ge Dongliang , Smith Jason P , Maia Jessica M , Heinzen Erin L , Goedert James J , Goldstein David B ,   the Center for HIV/AIDS Vaccine Immunology (CHAVI)
Published: May 2012

Background

There is considerable interest in the development of methods to efficiently identify all coding variants present in large sample sets of humans. There are three approaches possible: whole-genome sequencing, whole-exome sequencing using exon capture methods, and RNA-Seq. While whole-genome sequencing is the most complete, it remains sufficiently expensive that cost effective alternatives are important.

Results

Here we provide a systematic exploration of how well RNA-Seq can identify human coding variants by comparing variants identified through high coverage whole-genome sequencing to those identified by high coverage RNA-Seq in the same individual. This comparison allowed us to directly evaluate the sensitivity and specificity of RNA-Seq in identifying coding variants, and to evaluate how key parameters such as the degree of coverage and the expression levels of genes interact to influence performance. We find that although only 40% of exonic variants identified by whole genome sequencing were captured using RNA-Seq; this number rose to 81% when concentrating on genes known to be well-expressed in the source tissue. We also find that a high false positive rate can be problematic when working with RNA-Seq data, especially at higher levels of coverage.

Conclusions

We conclude that as long as a tissue relevant to the trait under study is available and suitable quality control screens are implemented, RNA-Seq is a fast and inexpensive alternative approach for finding coding variants in genes with sufficiently high expression levels.
Targeting acute myeloid leukemia cells with cytokines
Authors: Ferretti Elisa , Cocco Claudia , Airoldi Irma , Pistoia Vito
Published: May 2012

Review of data identifying IL-12 and IL-27 as potential therapeutic agents for pediatric AML by targeting leukemia initiating cells and/or blasts.

AML is a hematologic malignancy that represents 15–20% of all childhood acute leukemias and is responsible for more than one-half of pediatric leukemic deaths. The bulk tumor is continuously regenerated and sustained by rare leukemic ICs that proliferate slowly, thus resulting refractory to chemotherapeutic agents targeting highly proliferating cells within the tumor. Therefore, a complete eradication of the bulk tumor may depend on efficacy of therapies that target IC. In spite of the improvements in the treatment of AML, the difficulty to eradicate completely the disease incites research for innovative therapeutic approaches. In this regard, the role of cytokines in the treatment of AML has been investigated for many years, and some of them have been tested in clinical trials as a result of their immunomodulatory properties. Furthermore, recent preclinical studies highlighted the ability of the IL-12 superfamily cytokines as potent antileukemic agents that act directly on tumor cells and on leukemic IC, thus opening new perspectives for leukemic patient treatment. Here, we review the current knowledge about the antileukemic effects of cytokines, documented in preclinical and clinical studies, discussing their potential clinical application.
An improved tilt angle filter for potential field data
Authors: Cooper G. R. J.
Published: May 2012

The tilt angle, T, is a useful filter for enhancing subtle anomalies in potential field data. It is formed from the ratio, R, of the vertical derivative to the total horizontal derivative of the field (Equation 1). Because this ratio has a long-tailed distribution that can take on any value from −∞ to +∞, which is difficult to image satisfactorily, the range of values are compressed to ±π/2 using the arctan function. However there is nothing special about this function, and this paper suggests that a data-adaptive mapping of the histogram of the ratio to an equalized or a Gaussian distribution can give superior results.
Estimation of interval velocity and attenuation anisotropy from reflection data at Coronation Field
Authors: Behura Jyoti , Tsvankin Ilya , Jenner Edward , Calvert Alex
Published: May 2012

Attenuation can be extremely valuable in characterizing gas accumulations in shales and sandstones. Laboratory studies clearly indicate that attenuation is closely related to fluid saturation and mobility. Well-log analysis shows that P-wave attenuation is higher in gas-bearing rocks than in those saturated with oil or water. Extremely low P-wave quality factors (Q), ranging between 5 and 10, have been observed in some gas reservoirs. For example, such low Q values in gas sands are reported by Mavko and Dvorkin (2005) in well logs from the Gulf Coast.
Resistance to Obesity by Repression of VEGF Gene Expression through Induction of Brown-Like Adipocyte Differentiation
Authors: Lu Xiaodan , Ji Yan , Zhang Luqing , Zhang Yuntao , Zhang Shuzhi , An Yao , Liu Peng , Zheng Yaowu
Published: May 2012

Adipose tissues are classified into white adipose tissue (WAT) and brown adipose tissue (BAT). WAT is responsible for energy storage, and malfunction is associated with obesity. BAT, on the contrary, consumes fat to generate heat through uncoupling mitochondrial respiration and is important in body weight control. Vascular endothelial growth factor (VEGF)-A is the founding member of the VEGF family and has been found highly expressed in adipose tissue. A genetic mouse model of an inducible VEGF (VEGF-A) repression system was used to study VEGF-regulated energy metabolism in WAT. VEGF-repressed mice demonstrated lower food efficiency, lower body weight, and resistance to high-fat diet-induced obesity. Repression of VEGF expression caused morphological and molecular changes in adipose tissues. VEGF repression induced brown-like adipocyte development in WAT, up-regulation of BAT-specific genes including PRDM16, GATA-1, BMP-7, CIDEA, and UCP-1 and down-regulation of leptin, a WAT-specific gene. VEGF repression up-regulated expression of VEGF-B and its downstream fatty acid transport proteins. Relative levels of VEGF/VEGF-B may be important switches in energy metabolism and of pharmaceutical significances.
Combination Treatment with T4 and T3: Toward Personalized Replacement Therapy in Hypothyroidism?
Authors: Biondi Bernadette , Wartofsky Leonard
Published: May 2012

Context:

Levothyroxine therapy is the traditional lifelong replacement therapy for hypothyroid patients. Over the last several years, new evidence has led clinicians to evaluate the option of combined T3 and T4 treatment to improve the quality of life, cognition, and peripheral parameters of thyroid hormone action in hypothyroidism. The aim of this review is to assess the physiological basis and the results of current studies on this topic.

Evidence Acquisition:

We searched Medline for reports published with the following search terms: hypothyroidism, levothyroxine, triiodothyronine, thyroid, guidelines, treatment, deiodinases, clinical symptoms, quality of life, cognition, mood, depression, body weight, heart rate, cholesterol, bone markers, SHBG, and patient preference for combined therapy. The search was restricted to reports published in English since 1970, but some reports published before 1970 were also incorporated. We supplemented the search with records from personal files and references of relevant articles and textbooks. Parameters analyzed included the rationale for combination treatment, the type of patients to be selected, the optimal T4/T3 ratio, and the potential benefits of this therapy on symptoms of hypothyroidism, quality of life, mood, cognition, and peripheral parameters of thyroid hormone action.

Evidence Synthesis:

The outcome of our analysis suggests that it may be time to consider a personalized regimen of thyroid hormone replacement therapy in hypothyroid patients.

Conclusions:

Further prospective randomized controlled studies are needed to clarify this important issue. Innovative formulations of the thyroid hormones will be required to mimic a more perfect thyroid hormone replacement therapy than is currently available.
A Local Paracrine and Endocrine Network Involving TGFβ, Cox-2, ROS, and Estrogen Receptor β Influences Reactive Stromal Cell Regulation of Prostate Cancer Cell Motility
Authors: Grubisha Melanie J. , Cifuentes M. E. , Hammes Stephen R. , DeFranco Donald B.
Published: May 2012

The tumor microenvironment plays a critical role in supporting cancer cells particularly as they disengage from limitations on their growth and motility imposed by surrounding nonreactive stromal cells. We show here that stromal-derived androgenic precursors are metabolized by DU145 human prostate cancer (PCa) cells to generate ligands for estrogen receptor-β, which act to limit their motility through transcriptional regulation of E-cadherin. Although primary human PCa-associated fibroblasts and the human WPMY-1-reactive prostate stromal cell line maintain this inherent estrogen receptor (ER)β-dependent motility inhibitor activity, they are subverted by TGF-β1 pro-oxidant signals derived from cocultured DU145 PCa cells. Specifically, stromal-produced H2O2, which requires Cox-2, acts as a second paracrine factor to inhibit ERβ activity in adjacent DU145 cells. Chromatin immunoprecipitation analysis reveals that ERβ recruitment to the E-cadherin promoter is inhibited when H2O2 is present. Both neutralization of H2O2 with catalase and prevention of its production by silencing Cox-2 expression in stromal cells restore the motility-suppression activity of stromal-derived ERβ ligand precursors. These data suggest that reactive stromal cells may still have a capacity to limit cancer cell motility through a local endocrine network but must be protected from pro-oxidant signals triggered by cancer cell-derived TGF-β1 to exhibit this cancer-suppressive function.
Characterization of Follistatin-Type Domains and Their Contribution to Myostatin and Activin A Antagonism
Authors: Cash Jennifer N. , Angerman Elizabeth B. , Keutmann Henry T. , Thompson Thomas B.
Published: May 2012

Follistatin (FST)-type proteins are important antagonists of some members of the large TGF-β family of cytokines. These include myostatin, an important negative regulator of muscle growth, and the closely related activin A, which is involved in many physiological functions, including maintenance of a normal reproductive axis. FST-type proteins, including FST and FST-like 3 (FSTL3), differentially inhibit various TGF-β family ligands by binding each ligand with two FST-type molecules. In this study, we sought to examine features that are important for ligand antagonism by FST-type proteins. Previous work has shown that a modified construct consisting of the FST N-terminal domain (ND) followed by two repeating follistatin domains (FSD), herein called FST ND-FSD1-FSD1, exhibits strong specificity for myostatin over activin A. Using cell-based assays, we show that FST ND-FSD1-FSD1 is unique in its specificity for myostatin as compared with similar constructs containing domains from FSTL3 and that the ND is critical to its activity. Furthermore, we demonstrate that FSD3 of FST provides affinity to ligand inhibition and confers resistance to perturbations in the ND and FSD2, likely through the interaction of FSD3 of one FST molecule with the ND of the other FST molecule. Additionally, our data suggest that this contact provides cooperativity to ligand antagonism. Cross-linking studies show that this interaction also potentiates formation of 1:2 ligand-FST complexes, whereas lack of FSD3 allows formation of 1:1 complexes. Altogether, these studies support that domain differences generate FST-type molecules that are each uniquely suited ligand antagonists.
Coil embolization for treatment of vascular complications after nephron-sparing surgery
Authors: Krüger Karsten , Siakavara E
Published: May 2012

Nephron-sparing surgery (NSS) is a standard surgical treatment for small renal tumors. We report four patients (aged 35–79 years) with vascular complications within 6 days to 3 months after open NSS. Three patients developed acute symptoms, whereas one was asymptomatic. Computed tomography (CT) in the arterial and venous phase of contrast enhancement was performed for diagnosis, followed by angiography. CT demonstrated a perirenal hematoma in three and an arterial pseudoaneurysm in two cases. Unlike CT, digital subtraction angiography confirmed an arterial pseudoaneurysm in all cases and additionally found an arteriovenous fistula in three. In all cases, angiography-guided coil embolization successfully treated the vascular pathology, while preserving renal function. Clinicians should understand the diagnosis and management of this complication of NSS.
Comparison between visual assessment of MTA and hippocampal volumes in an elderly, non-demented population
Authors: Cavallin Lena , Bronge Lena , Zhang Yi , Øksengård Anne-Rita , Wahlund Lars-Olof , Fratiglioni Laura , Axelsson Rimma
Published: May 2012

Background

It is important to have a replicable easy method for monitoring atrophy progression in Alzheimer's disease. Volumetric methods for calculating hippocampal volume are time-consuming and commonly used in research. Visual assessments of medial temporal lobe atrophy (vaMTA) is a rapid method for clinical use. This method has not been tested in a large non-demented population in comparison with volumetry mesurements. Since hippocampal volume decreases with time even in normal aging there is also a need to study the normal age differences of medial temporal lobe atrophy.

Purpose

To compare visual assessment of medial temporal lobe atrophy (vaMTA) with hippocampal volume in a healthy, non-demented elderly population. To describe normal ageing using vaMTA.

Material and Methods

Non-demented individuals aged 60, 66, 72, 78, 81, 84, and ≥87 years old were recruited from the Swedish National study on Ageing and Care in Kungsholmen (SNAC-K), Sweden. Standard magnetic resonance imaging (MRI) scans, vaMTA, and calculations of hippocampal volumes were performed in 544 subjects.

Results

Significant correlation (rs = −0.32, P < 0.001, sin; and rs = −0.26, P < 0.001, dx) was found between hippocampal volume measurements and vaMTA. In normal ageing, almost 95% of ≤66-year-olds had a medial temporal lobe atrophy (MTA) score ≤1, with possible scores ranging from 0 to 4. Subjects aged 72, 78, and 81 years scored ≤2, while the two oldest age groups had scores ≤3.

Conclusion

There was a highly significant correlation between volumetric measurements of the hippocampus and MTA scoring. In normal ageing, there is increasing MTA score. For non-demented elderly individuals ≤70 years, an MTA score of 0–1 may be considered normal, compared with MTA ≤2 for 70–80-years and MTA 3 for >80-year-old individuals.
Testing and Use of Environmentally Acceptable Lubricants
Authors: Rhee In-Sik
Published: May 2012

Description

Discover the latest research on biobased and other Environmentally Acceptable (EA) Lubricants. With the increased interest in EA Lubricants, this book is a must-have for those in the agricultural, construction, forestry, lumber, and mining industries where involuntary or accidental fluid leakage or spillage is detrimental to the environment.

Ten peer-reviewed papers cover
Performance Comparison and Design Issue on Different GaN Power Transistor Structures
Authors: Lee Chwan-Ying , Hung Chien-Chung , Kuo Wei-Hung , Chen Young-Shying , Lee Lurng-Shehng , Yen Cheng-Tyng , Lin Suh-Fang , Xuan Rong , Ku Tzu-Kun , Tsai Ming-Jinn
Published: May 2012

Three types of Ganium Nitride (GaN) transistors were studied in this work. The devices were fabricated and exhibited unique characteristics over on-state current and off-state blocking performances. We also compared the performance differences of devices fabricated by multiepitaxial GaN/AlGaN layers on different substrates (Sapphire and Si) and evaluated the correlations among starting substrate, device variation, and manufacturing uniformity. The first device is a normally-on device with Sapphire substrate which shows good drain saturation current (Idsat) and breakdown characteristics, but the gate leakage current is quite large. The second device is a normally-off GaN transistor named metal-insulate-semiconductor (MIS) heterojunction field-effect transistor (MIS-HFET) which exhibits good performance with threshold voltage (Vth) of 3V and breakdown voltage (Vbd) of over 1800V. However the third device is a normally-off GaN metal-oxide-semiconductor field-elect transistor (MOSFET) structure which is rather difficult to exhibit good blocking characteristic due to inadequate doping process control of the reduce-surface-field (RESURF) region.
Lift-off Methods for MEMS Devices
Authors: Chang Shih-Chia , Kempisty Jeffrey M.
Published: May 2012

Five different methods were explored for the formation of the lift-off mold. In the first method, a tri-level resist scheme was used to generate a lift-off mold. The lift-off mold has a vertical wall slope. In the second method, an aluminum/photoresist double layer was used as the mold material. An overhang structure is obtained by undercutting the underlying aluminum layer. In the third method, a composite layer of two different photoresists (AZ 1811 and LOR 10A) was used to form the lift-off mold. With the fast dissolution rate of the underlying LOR 10A photoresist an overhanging mask structure was obtained. Since regular photoresists were used as part of the mold material in these three lift-off methods, they are suitable for thin film materials with thickness of ≤2 μm and processing temperatures ≤100°C. For thicker device film materials and higher processing temperature (∼200°C), methods 4 and 5 using negative resists, Futurrex NR7-3000PY (∼3 μm) and SU-8 (∼50 μm), respectively, were experimented with to form the lift-off mask. The fabrication processes used in these two methods were relatively simple and a negative wall slope was readily obtained. While Futurrex photoresist is easily stripped by the resist remover provided by the manufacturer, there is no effective chemical solution available for the removal of SU-8. We found that plasma etching with a mixture of O2 and C2F6 can be used for the removal of SU-8.
Micro-Molded High Q Polymer Resonators for Optical Loss Determination
Authors: Martin Andrea L. , Srinivasan Akil , Armani Deniz K. , Min Bumki , Vahala Kerry J.
Published: May 2012

Replica molding of ultra-high-Q toroidal microresonators can produce polymer microresonators with material-limited quality factors (Q). This was demonstrated previously using polymers which cure thermally. In this work, high Q polymer microresonators were fabricated using the replica molding technique from previously uncharacterized polymers which require either a thermal or UV cure. The quality factor and effective refractive index of whispering gallery modes was measured at wavelengths ranging from the visible (680nm) through the near-IR (1550nm). The optical absorption coefficient (material absorption) of these previously uncharacterized polymers was determined from the quality factor and effective refractive index of the polymer.
Non-linear analysis of steel fibre reinforced concrete-filled steel tube columns
Authors: Guler Soner , Lale Erol , Aydogan Metin
Published: May 2012

This paper investigates the behaviour of circular steel fibre reinforced concrete-filled steel tube columns using experimental and numerical results. Seven circular steel fibre reinforced concrete-filled steel tube columns were tested under axial load. The experimental results were compared with finite-element analysis results and various design codes. The commercial finite-element program Abaqus was used in the analysis. The plastic-damage concrete model was employed to represent the behaviour of concrete. The results showed good agreement between the finite-element model and the test results. The largest difference in axial load capacity between the test results and the finite-element analysis was 8%. The reliability of design codes was analysed in terms of agreement with the experimental results.
Slums and Malnourishment: Evidence From Women in India
Authors: Swaminathan Hema , Mukherji Arnab
Published: May 2012

Objectives. We examined the association between slum residence and nutritional status in women in India by using competing classifications of slum type.

Methods. We used nationally representative data from the 2005–2006 National Family Health Survey (NFHS-3) to create our citywide analysis sample. The data provided us with individual, household, and community information. We used the body mass index data to identify nutritional status, whereas the residential status variable provided slum details. We used a multinomial regression framework to model the 3 nutrition states—undernutrition, normal, and overnutrition.

Results. After we controlled for a range of attributes, we found that living in a census slum did not affect nutritional status. By contrast, living in NFHS slums decreased the odds of being overweight by 14% (95% confidence interval [CI] = 0.79, 0.95) and increased the odds of being underweight by 10% (95% CI = 1.00, 1.22).

Conclusions. The association between slum residence and nutritional outcomes is nuanced and depends on how one defines a slum. This suggests that interventions targeted at slums should look beyond official definitions and include current living conditions to effectively reach the most vulnerable.
Changes in Smoking Prevalence in 8 Countries of the Former Soviet Union Between 2001 and 2010
Authors: Roberts Bayard , Gilmore Anna , Stickley Andrew , Rotman David , Prohoda Vladimir , Haerpfer Christian , McKee Martin
Published: May 2012

Objectives. We sought to present new data on smoking prevalence in 8 countries, analyze prevalence changes between 2001 and 2010, and examine trend variance by age, location, education level, and household economic status.

Methods. We conducted cross-sectional household surveys in 2010 in Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Russia, and Ukraine. We compared smoking prevalence with a related 2001 study for the different countries and population subgroups, and also calculated the adjusted prevalence rate ratios of smoking.

Results. All-age 2010 smoking prevalence among men ranged from 39% (Moldova) to 59% (Armenia), and among women from 2% (Armenia) to 16% (Russia). There was a significantly lower smoking prevalence among men in 2010 compared with 2001 in Belarus, Kazakhstan, Kyrgyzstan, and Russia, but not for women in any country. For all countries combined, there was a significantly lower smoking prevalence in 2010 than in 2001 for men aged 18 to 39 years and men with a good or average economic situation.

Conclusions. Smoking prevalence appears to have stabilized and may be declining in younger groups, but remains extremely high among men, especially those in lower socioeconomic groups.