bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of Peripheral Arterial Disease and Its Relevance to the Diabetic Population
Authors: Faglia Ezio
Published: August 2011

Peripheral arterial disease (PAD) is very frequent in diabetics, and it increases with age. Foot examination contributes poorly to diagnosis of PAD. The ankle-brachial index (ABI) measurement is considered the most accurate noninvasive diagnostic method when evaluating PAD: ABI evaluation is recommended in all diabetics aged >50 years. Many diabetic patients with PAD have a concomitant sensitive neuropathy: as a consequence, perception of ischemic pain is remarkably reduced or completely blocked. The result is that the prevalence of claudication in the diabetic population with PAD is lower than the prevalence of critical limb ischemia (CLI) in this population. CLI is a major risk factor for lower extremity amputation without revascularization. Ankle and toe pressures and oxygen tension at the foot are the noninvasive diagnostic parameters of CLI though the medial artery calcification inhibits accurate determination of the ankle and toe pressures, especially when a forefoot ulcer is present. In diabetics, the anatomical localization is mainly distal; arterial wall calcification is frequently observed and occlusion occurs more frequently than stenosis. Such anatomical features, along with the difficulties in the diagnostic approach, account for the fundamental role of CLI as the main prognostic indicator for major amputation. PAD is an expression of systemic atherosclerotic disease. Prognosis of patients with PAD is related to the presence and extent of underlying coronary artery disease (CAD) but also to the severity of PAD: in particular, patients in whom revascularization is not feasible have the highest mortality rate.
Differential Keratin Expression During Epiboly in a Wound Model of Bioengineered Skin and in Human Chronic Wounds
Authors: Luo Su , Yufit Tatyana , Carson Polly , Fiore David , Falanga Jane , Lin Xiaofeng , Mamakos Lisa , Falanga Vincent
Published: August 2011

Epiboly represents the process by which keratinocytes migrate to envelop a surface. The authors have been investigating a living bilayered skin construct (BSC) that is used in the treatment of lower extremity wounds due to venous insufficiency and diabetes. The construct demonstrates epiboly after injury and incubation in vitro, and this model may be useful for studying epidermal migration and the process of skin maturation. Punch biopsies of the construct in vitro were cultured and immunostained for specific keratins at baseline and at 24 to 72 hours. For comparison, skin biopsy specimens from human chronic venous ulcers and acute healing wounds were similarly processed. The authors found that K1 and K10 were fully expressed in the epidermis of the fully epibolized surface on BSC. K1 was also present in the migrating edge of specimens, whereas K10 was not detectable. K16 and K6 were evident in normal skin and the epibolized area of the construct; K6 expression was very prominent in the migrating edge. Importantly, K17 was distinctly limited to the epibolized surface and the migrating edge, and its expression was very similar to that observed in healing human wounds. In conclusion, differential expression of keratins in this epiboly model closely reflects in vivo studies and supports keratin specificity in the processes of migration and differentiation of new epidermis. Therefore, these findings provide further and important validity for the study of epithelialization and the hope of developing prognostic markers for venous ulcer healing.
Factors Affecting Gentamicin Penetration in Lower Extremity Ischemic Tissues With Ulcers
Authors: Zammit Marie Clare , Fiorentino Lara , Cassar Kevin , Azzopardi Lilian M. , LaFerla Godfrey
Published: August 2011

The aims of the study were to analyze the penetration of gentamicin in foot ulcers in patients with different severities of peripheral arterial disease (PAD) and to determine significant parameters affecting lower limb tissue concentrations. Patients undergoing debridement of a wound or an amputation procedure were included. All patients received a 120 mg or 240 mg intravenous dose of gentamicin prior to the procedure. Patients were classified according to the degree of PAD. Tissue and serum samples were collected at the time of intervention, and gentamicin concentrations were determined by fluorescence polarization immunoassay. Blood and tissue samples were taken from 61 patients, 41 males and 20 females with a mean age of 66 years. Nineteen patients had nil or borderline PAD, 9 patients had mild or moderate PAD, and 26 patients had severe PAD. Forty-eight patients had type 2 diabetes, 8 patients had type 1 diabetes, and 5 patients were nondiabetic. The concentration of gentamicin in peripheral skeletal muscle tissue was dependent on the serum concentration, degree of PAD, gender, and age. For patients with ischemic lower extremity wounds (patients with mild, moderate, and severe PAD), the concentration of gentamicin was significantly lower ( P = .010) than the concentration in nonischemic wounds, and the concentration in female patients was also significantly lower than in male patients ( P = .047). The concentration in peripheral subcutaneous tissue was 0.663 times the concentration in skeletal muscle tissue ( P < .00001). Gentamicin showed greatest penetration in male patients without PAD. For patients with severe PAD, higher doses of gentamicin may be required to achieve the same effect.
Preliminary Evidence of Significant Gaps in Continuity of HIV Care among Excarcerated Populations in Puerto Rico
Authors: Clatts Michael C. , Rodriguez-Díaz Carlos E. , García Hermes , Vargas-Molina Ricardo L. , Jovet-Toledo Gerardo G. , Goldsamt Lloyd A.
Published: August 2011

Objective: Puerto Rico has high HIV prevalence and incidence rates, including a large prison population living with HIV. While HIV treatment is available within the prisons, there are no linkages to care or treatment preparedness interventions following release. Methods: In an effort to assess the risk of treatment discontinuity in this group, we examined data from an ongoing epidemiological study in the largest, publicly funded HIV/sexually transmitted infection (STI) treatment center in the San Juan area. Results: Among the newly enrolled, HIV-positive patients with a history of incarceration, there was an average 4-year gap in reengagement in treatment. Drug and sexual risk behaviors were prevalent, as was evidence of significant immune impairment (including high viral load and low CD4 count). Conclusions: Treatment discontinuity may contribute to poor health outcomes in this group and also fuel new infections. There is an urgent need for interventions to retain HIV-positive inmates in community HIV care following release.
Fatigue Perceived by Multiple Sclerosis Patients Is Associated With Muscle Fatigue
Authors: Steens Anneke , de Vries Astrid , Hemmen Jolien , Heersema Thea , Heerings Marco , Maurits Natasha , Zijdewind Inge
Published: August 2011

Background. Fatigue is a debilitating symptom in multiple sclerosis (MS). Previous studies showed no association between fatigue as perceived by the patient and physiological measures of fatigability. Objective. The authors investigated associations between perceived fatigue and measures of fatigability after correction for differences in maximal voluntary contraction (MVC). Methods. A total of 20 people with relapsing-remitting MS with an Extended Disability Severity Score less than 5.5 and 20 healthy controls filled out the Fatigue Severity Score questionnaire of perceived fatigue. The authors obtained the MVC from the first dorsal interosseus muscle, voluntary muscle activation, and force decline during a sustained MVC (124 s, muscle fatigue). Results. Patients perceived increased levels of fatigue compared with controls ( P < .001). Although patients and controls developed similar amounts of muscle fatigue during the sustained contraction, a linear regression model that included both muscle fatigue and MVC was positively associated with perceived fatigue in patients only ( R2 = 0.45; P = .01). Voluntary activation during the sustained contraction was negatively associated with perceived fatigue ( R2 = 0.25; P = .02). Conclusion. The data indicate that fatigue perceived by MS patients is associated with measures of fatigability. This observation helps in the understanding of mechanisms underlying the increased levels of fatigue perceived by MS patients. These data also emphasize that for comparison of fatigue-related parameters between groups, correction for individual maximal force is essential.
Affective Interaction
Authors: Lottridge Danielle , Chignell Mark , Jovicic Aleksandra
Published: August 2011

This chapter reviews relevant research on emotion, focusing on aspects of emotion that are most relevant to human factors design. The review begins with a discussion of basic emotion concepts, such as low-level positive and negative affect; emotion dimensions of arousal and valence; and prototypical emotions, such as anger, happiness, and fear. The interaction between emotion processing and cognitive processes, such as attention, perception, and decision making, is also discussed. After a review of the nature of emotion, the problem of measuring emotions is considered. Available techniques for emotion measurement are surveyed, and recommendations are made concerning which techniques should be used in different contexts and interactive settings. Novel measures are also introduced for assessing variability in emotional experience and for measuring emotional expressiveness. After laying the intellectual groundwork for understanding the nature of emotional interaction and its measurement, the chapter then shifts to exploring the implications of emotional processing for the design of interactive systems. Affective designs are reviewed in the following domains: consumer products, health care, and robots. The chapter concludes with presentation of an initial set of guidelines relating to the design of interactive systems that take into account emotional processing. The material presented in this chapter is highly relevant to human factors engineering because knowledge of emotional processing and how it affects the state of operators or users and their performance can lead to more usable, effective, efficient, and satisfying interaction.
Information Environment, Fatigue, and Culture in the Maritime Domain
Authors: Lützhöft Margareta , Grech Michelle R. , Porathe Thomas
Published: August 2011

Maritime shipping operates within a complex operational setting and incorporates many types of workplaces and work roles. The maritime domain has been a bit slower than other complex domains in its research and development of human factors and ergonomics application. The problem remains that the operator is continuously being excluded from the loop, which increases the probability of shipboard errors and accidents. This chapter begins by providing a general introduction to the maritime domain and its unique characteristics and is followed by a section on the information environment on the bridge. The section on the information environment on the bridge highlights the importance of integrating the end user into the bridge system and how technology must provide intuitive information at the right level of complexity at the right time. The main focus of this chapter is then split into two areas of current high significance: fatigue on board and maritime culture (also incorporating safety culture issues). Fatigue on board is of major concern, and most studies indicate that a systems approach must be adopted. This approach should account for aspects such as the number of personnel, trip length, frequency and duration of port visits, and shift planning. Within the area of maritime culture, multiculturalism and the way it is managed on board ships, including shipboard practices, affect safety. In the area of safety culture, three recommendations are central: (a) increase compliance with regulations, (b) implement a safety management system, and (c) implement a behavioral safety system. In general, this review indicates that more data are needed on human-technology-organizational issues in the maritime domain.
The Human Factors of Night Vision Goggles
Authors: Parush Avi , Gauthier Michelle S. , Arseneau Lise , Tang Denis
Published: August 2011

The technology underlying night vision goggles (NVGs) enhances human ability to operate in dark and low-light conditions. However, NVG-aided vision is limited relative to daylight human vision and may entail risks. This review focuses on NVGs with image intensifier technology and explores the impact of their use on human performance. The review covers technology and device characteristics (image quality and field of view), physical configuration (ocular configuration, NVG weight, and forward center of gravity), and contextual and environmental factors (mission and task aspects, lighting, weather, and terrain). The key human factors in NVG use are visual and cognitive performance (visual acuity and contrast sensitivity, stereopsis and depth perception, distance and size estimation, spatial orientation, and situation awareness), and physical and physiological aspects (neck strain and injuries, and headaches). Understanding technology and contextual factors and their influence on human factors is critical to improving performance and safety with NVGs. Technology and device improvements, along with appropriate mission planning and training, play a critical role in aided night vision performance.
First-Rib Stress Fracture in a High-School Lacrosse Player
Authors: Wild Aaron T. , Begly John P. , Garzon-Muvdi Juan , Desai Pingal , McFarland Edward G.
Published: August 2011

A 14-year-old right-hand dominant female lacrosse player presented with a complaint of right shoulder and upper posterior thorax pain of 8 days’ duration. She had been playing lacrosse at the attack wing and midfielder positions and experienced insidious pain after a game. She had no history of trauma to that shoulder during that game and had not experienced an injury in the past. Six days after the pain developed, she woke up one night with a sudden increase in the pain, which brought her to tears and caused slight difficulty with breathing. The pain was located anteriorly just lateral to the right sternoclavicular joint and posteriorly in the paraspinal muscles in the upper thoracic region. Physical examination suggested a first-rib stress fracture, which was subsequently confirmed by chest and shoulder radiographs.
Medicines reconciliation on admission to inpatient psychiatric care: findings from a UK quality improvement programme
Authors: Paton Carol , McIntyre Samantha , Bhatti Sumera F. , Shingleton-Smith Amber , Gray Richard , Gerrett David , Barnes Thomas R. E.
Published: August 2011

Objective: Medication errors are a common cause of avoidable morbidity, and transfer between clinical settings is a known risk factor for such errors. Medicines reconciliation means there is no unintended discrepancy between the medication prescribed for a patient prior to admission and on admission. Our aim was to improve the quality of practice supporting medicines reconciliation at the point of admission to a psychiatric ward.

Methods: An audit-based quality improvement programme (QIP), using the proxy measure for medicines reconciliation of two or more sources of information being consulted about current medicines, and compared.

Results: At baseline audit, 42 Trusts submitted data for 1790 patients. At re-audit 16 months later, 43 Trusts submitted data for 2296 patients. While doctors were most commonly identified in Trust policies as having overall responsibility for medicines reconciliation, the task was most often undertaken by pharmacy staff, with most activity occurring within 24 h of admission. The proportion of patients in whom medicines reconciliation was possible was 71% at baseline and 79% at re-audit. In such patients, discrepancies were identified in 25% at baseline and 31% at re-audit; a small proportion of these discrepancies were clearly clinically significant.

Conclusions: This QIP achieved modest improvement in medicines reconciliation practice.
Pre-B cell receptor–mediated activation of BCL6 induces pre-B cell quiescence through transcriptional repression of MYC
Authors: Nahar Rahul , Ramezani-Rad Parham , Mossner Maximilian , Duy Cihangir , Cerchietti Leandro , Geng Huimin , Dovat Sinisa , Jumaa Hassan , Ye B. Hilda , Melnick Ari , Müschen Markus
Published: August 2011

Initial cell surface expression of the pre-B cell receptor induces proliferation. After 2 to 5 divisions, however, large pre-BII (Fraction C') cells exit cell cycle to become resting, small pre-BII cells (Fraction D). The mechanism by which pre-BII cells exit cell cycle, however, is currently unclear. The checkpoint at the Fraction C'-D transition is critical for immunoglobulin light chain gene recombination and to prevent malignant transformation into acute lymphoblastic leukemia. Here we demonstrate that inducible activation of pre-B cell receptor signaling induces cell-cycle exit through up-regulation of the transcriptional repressor BCL6. Inducible activation of BCL6 downstream of the pre-B cell receptor results in transcriptional repression of MYC and CCND2. Hence, pre-B cell receptor-mediated activation of BCL6 limits pre-B cell proliferation and induces cellular quiescence at the small pre-BII (Fraction D) stage.
Prevention of GVHD while sparing GVL effect by targeting Th1 and Th17 transcription factor T-bet and RORγt in mice
Authors: Yu Yu , Wang Dapeng , Liu Chen , Kaosaard Kane , Semple Kenrick , Anasetti Claudio , Yu Xue-Zhong
Published: August 2011

Allogeneic hematopoietic cell transplantation (HCT) is effective therapy for hematologic malignancies through T cell–mediated GVL effects. However, HCT benefits are frequently offset by the destructive GVHD, which is also induced by donor T cells. Naive Th can differentiate into Th1 and Th17 subsets and both can mediate GVHD after adoptive transfer into an allogeneic host. Here we tested the hypothesis that blockade of Th1 and Th17 differentiation is required to prevent GVHD in mice. T cells with combined targeted disruption of T-bet and RORγt have defective differentiation toward Th1 and Th17 and skewed differentiation toward Th2 and regulatory phenotypes, and caused ameliorated GVHD in a major MHC-mismatched model of HCT. GVL effects mediated by granzyme-positive CD8 T cells were largely preserved despite T-bet and RORγt deficiency. These data indicate that GVHD can be prevented by targeting Th1 and Th17 transcription factors without offsetting GVL activity.
cMyb regulates hematopoietic stem/progenitor cell mobilization during zebrafish hematopoiesis
Authors: Zhang Yiyue , Jin Hao , Li Li , Qin F. Xiao-Feng , Wen Zilong
Published: August 2011

The establishment of the HSC pool in vertebrates depends not only on the formation and the propagation of these stem cells but also on their proper trafficking among the defined hematopoietic organs. However, the physiologic mechanisms that regulate HSC mobilization remain elusive. Through analysis of the zebrafish cmyb mutant cmybhkz3, we show that the suppression of cMyb function abrogates larval and adult hematopoiesis, with concomitant accumulation of hematopoietic stem/progenitor cells (HSPCs) in their birthplace, the ventral wall of the dorsal aorta (VDA). Cell tracking and time-lapse recording reveal that the accumulation of HSPCs in cmybhkz3 mutants is caused by the impairment of HSPC egression from the VDA. Further analysis demonstrates that the HSPC migratory defects in cmybhkz3 mutants are at least partly because of adversely elevated levels of chemokine stromal cell-derived factor 1a (Sdf1a). Our study reveals that cMyb plays a hitherto unidentified role in dictating physiologic HSPC migration by modulating Sdf1a signaling.
Distribution, function, and prognostic value of cytotoxic T lymphocytes in follicular lymphoma: a 3-D tissue-imaging study
Authors: Laurent Camille , Müller Sabina , Do Catherine , Al-Saati Talal , Allart Sophie , Larocca Luigi Maria , Hohaus Stefan , Duchez Sophie , Quillet-Mary Anne , Laurent Guy , Brousset Pierre , Valitutti Salvatore
Published: August 2011

CD8+ CTLs are thought to play a role in the control of follicular lymphoma (FL). Yet, the link between CTL tissue distribution, activation status, ability to kill FL cells in vivo, and disease progression is still elusive. Pretreatment lymph nodes from FL patients were analyzed by IHC (n = 80) or by 3-color confocal microscopy (n = 10). IHC revealed a rich infiltrate of CD8+ granzyme B+ (GrzB) cells in FL interfollicular spaces. Accordingly, confocal microscopy showed an increased number of CD3+CD8+GrzB+ CTLs and a brighter GrzB staining in individual CTL in FL samples compared with reactive lymph nodes. CTLs did not penetrate tumor nodules. In 3-dimensional (3-D) image reconstructions, CTLs were detected at the FL follicle border where they formed lytic synapse-like structures with FL B cells and with apoptotic cells, suggesting an in situ cytotoxic function. Finally, although GrzB expression in CTLs did not correlate with risk factors, high GrzB content correlated with prolonged progression free-survival (PFS) after rituximab-combined chemotherapy. Our results show the recruitment of armed CTLs with a tumor-controlling potential into FL lymph nodes and suggest that CTL-associated GrzB expression could influence PFS in FL patients having received rituximab-combined chemotherapy.
Ofatumumab is active in patients with fludarabine-refractory CLL irrespective of prior rituximab: results from the phase 2 international study
Authors: Wierda William G. , Padmanabhan Swaminathan , Chan Geoffrey W. , Gupta Ira V. , Lisby Steen , Österborg Anders ,   for the Hx-CD20-406 Study Investigators
Published: August 2011

Ofatumumab, the human CD20 monoclonal antibody that binds a distinct epitope from rituximab, has demonstrated clinical benefit as monotherapy for patients with chronic lymphocytic leukemia refractory to fludarabine and alemtuzumab (FA-ref) and patients refractory to fludarabine with bulky (> 5 cm) lymph nodes (BF-ref). To potentially gain insight into outcomes in patients previously treated with or refractory to rituximab, we performed an ad hoc retrospective analysis in the final 96 FA-ref and 111 BF-ref patients. There were 117 patients previously treated with rituximab (98 rituximab-refractory); 89 patients were rituximab-naive. For rituximab-treated, rituximab-refractory, and rituximab-naive patients, overall response rate was 43%, 44%, and 53%; median progression-free survival was 5.3, 5.5, and 5.6 months; and median overall survival was 15.5, 15.5, and 20.2 months. There were no significant differences in ofatumumab-related infusion reactions, or hematologic or infectious adverse events between subgroups. In summary, ofatumumab monotherapy was effective and well tolerated in patients with fludarabine-refractory chronic lymphocytic leukemia, including in patients with previous rituximab exposure. This trial was registered at www.clinicaltrials.gov as #NCT00349349.
Identification, structure, and characterization of an exopolysaccharide produced by Histophilus somniduring biofilm formation
Authors: Sandal Indra , Inzana Thomas J , Molinaro Antonio , Castro Christina De , Shao Jian Q , Apicella Michael A , Cox Andrew D , Michael Frank St , Berg Gretchen
Published: August 2011

Background

Histophilus somni, a gram-negative coccobacillus, is an obligate inhabitant of bovine and ovine mucosal surfaces, and an opportunistic pathogen responsible for respiratory disease and other systemic infections in cattle and sheep. Capsules are important virulence factors for many pathogenic bacteria, but a capsule has not been identified onH. somni. However,H. somnidoes form a biofilmin vitroandin vivo, and the biofilm matrix of most bacteria consists of a polysaccharide.

Results

Following incubation ofH. somniunder growth-restricting stress conditions, such as during anaerobiosis, stationary phase, or in hypertonic salt, a polysaccharide could be isolated from washed cells or culture supernatant. The polysaccharide was present in large amounts in broth culture sediment afterH. somniwas grown under low oxygen tension for 4-5 days (conditions favorable to biofilm formation), but not from planktonic cells during log phase growth. Immuno-transmission electron microscopy showed that the polysaccharide was not closely associated with the cell surface, and was of heterogeneous high molecular size by gel electrophoresis, indicating it was an exopolysaccharide (EPS). The EPS was a branched mannose polymer containing some galactose, as determined by structural analysis. The mannose-specificMoringa Mlectin and antibodies to the EPS bound to the biofilm matrix, demonstrating that the EPS was a component of the biofilm. The addition ofN-acetylneuraminic acid to the growth medium resulted in sialylation of the EPS, and increased biofilm formation. Real-time quantitative reverse transcription-polymerase chain reaction analyses indicated that genes previously identified in a putative polysaccharide locus were upregulated when the bacteria were grown under conditions favorable to a biofilm, compared to planktonic cells.

Conclusions

H. somniis capable of producing a branching, mannose-galactose EPS polymer under growth conditions favorable to the biofilm phase of growth, and the EPS is a component of the biofilm matrix. The EPS can be sialylated in strains with sialyltransferase activity, resulting in enhanced density of the biofilm, and suggesting that EPS and biofilm formation may be important to persistence in the bovine host. The EPS may be critical to virulence if the biofilm state is required forH. somnito persist in systemic sites.
Branch retinal vein occlusion associated with quetiapine fumarate
Authors: Yong Ku Chui , Kah Tan Aik , Ghee Yeap Thye , Siang Lim Chee , Bastion Mae-Lynn Catherine
Published: August 2011

Background

To report a case of branch retinal vein occlusion in a young adult with bipolar mood disorder treated with quetiapine fumarate.

Case Presentation

A 29 years old gentleman who was taking quetiapine fumarate for 3 years for bipolar mood disorder, presented with sudden vision loss. He was found to have a superior temporal branch retinal vein occlusion associated with hypercholesterolemia.

Conclusion

Atypical antipsychotic drugs have metabolic side effects which require regular monitoring and prompt treatment.
Hands4U: A multifaceted strategy to implement guideline-based recommendations to prevent hand eczema in health care workers: design of a randomised controlled trial and (cost) effectiveness evaluation
Authors: van der Meer Esther WC , Boot Cécile RL , Jungbauer Frank HW , van der Klink Jac JL , Rustemeyer Thomas , Coenraads Pieter Jan , van der Gulden Joost W , Anema Johannes R
Published: August 2011

Background

Workers in wet work occupations have a risk for developing hand eczema. Prevention strategies exist, but compliance to the proposed recommendations is poor. Therefore, a multifaceted implementation strategy (MIS) is developed to implement these recommendations to reduce hand eczema among health care workers performing wet work.

Methods/Design

This study is a randomised controlled trial in three university hospitals in the Netherlands. Randomisation to the control or intervention group is performed at department level. The control group receives a leaflet containing the recommendations only. The intervention group receives the MIS which consists of five parts: 1) within a department, a participatory working group is formed to identify problems with the implementation of the recommendations, to find solutions for it and implement these solutions; 2) role models will help their colleagues in performing the desired behaviour; 3) education to all workers will enhance knowledge about (the prevention of) hand eczema; 4) reminders will be placed at the department reminding workers to use the recommendations; 5) workers receive the same leaflet as the control group containing the recommendations. Data are collected by questionnaires at baseline and after 3, 6, 9 and 12 months. The primary outcome measure is self-reported hand eczema. The most important secondary outcome measures are symptoms of hand eczema; actual use of the recommendations; sick leave; work productivity; and health care costs.

Analyses will be performed according to the intention to treat principle. Cost-effectiveness of the MIS will be evaluated from both the societal and the employer's perspective.

Discussion

The prevention of hand eczema is important for the hospital environment. If the MIS has proven to be effective, a major improvement in the health of health care workers can be obtained. Results are expected in 2014.

Trial registration number

NTR2812
LIP expression is regulated by IGF-1R signaling and participates in suppression of anoikis
Authors: Li Huili , Baldwin Brenda R , Zahnow Cynthia A
Published: August 2011

Background

The transcription factor, CCAAT enhancer binding protein-β (C/EBPβ), is expressed as several distinct protein isoforms (LAP1, LAP2 and LIP) that have opposing actions in cellular proliferation and differentiation. Increases in the ratio of LIP/LAP are associated with aggressive, metastatic breast cancer; however, little is known regarding the molecular mechanisms that regulate LIP expression or the biological actions of an increase in the LIP/LAP ratio. Metastasis is highly dependent upon the suppression of anoikis and the role of C/EBPβ and LIP in this anchorage-independent, survival process is currently not known in mammary epithelial cells. IGF-1R signaling is important for the survival of breast cancer cells and crosstalk between IGF-1R and EGFR signaling pathways have been implicated in the development of more aggressive disease. We therefore evaluated in mammary epithelial cells whether IGF-1R signaling regulates the LIP/LAP ratio, analyzed the potential interplay between EGFR and IGF-1R signaling and addressed the biological significance of increased LIP expression in cellular survival and suppression of anoikis.

Results

Our data provide the first evidence that IGF-1R signaling regulates LIP expression in an EGFR independent manner to increase the LIP/LAP ratio in mammary epithelial cells. Although crosstalk between IGF-1R signaling and EGFR signaling is detectable in MCF10A cells, this crosstalk is not required for the IGF-1 mediated regulation of LIP expression. Rather, the critical regulator of IGF-1 induced LIP expression appears to be EGFR-independent, Akt activity. Our data also demonstrate that increases in LIP expression promote cell survival via suppression of anoikis. Likewise, knockdown of total C/EBPβ leads to increased cell death and suggest that C/EBPβ expression is important for survival and resistance to anoikis. IGF-1 treatment can partially rescue vector control cells from anoikis; however, cells with reduced C/EBPβ expression do not survive anoikis.

Conclusions

Taken together, our data demonstrate that IGF-1R signaling regulates LIP expression in an EGFR independent manner to increase the LIP/LAP ratio in mammary epithelial cells. C/EBPβ expression and elevations in LIP play an important role in regulating cellular survival via suppression of anoikis, in an IGF-1R mediated context or in a manner independent of IGF-1R signaling.
Engineering of an E. coli outer membrane protein FhuA with increased channel diameter
Authors: Krewinkel Manuel , Dworeck Tamara , Fioroni Marco
Published: August 2011

Background

Channel proteins like FhuA can be an alternative to artificial chemically synthesized nanopores. To reach such goals, channel proteins must be flexible enough to be modified in their geometry, i.e. length and diameter. As continuation of a previous study in which we addressed the lengthening of the channel, here we report the increasing of the channel diameter by genetic engineering.

Results

The FhuA Δ1-159 diameter increase has been obtained by doubling the amino acid sequence of the first two N-terminal β-strands, resulting in variant FhuA Δ1-159 Exp. The total number of β-strands increased from 22 to 24 and the channel surface area is expected to increase by ~16%. The secondary structure analysis by circular dichroism (CD) spectroscopy shows a high β-sheet content, suggesting the correct folding of FhuA Δ1-159 Exp. To further prove the FhuA Δ1-159 Exp channel functionality, kinetic measurement using the HRP-TMB assay (HRP = Horse Radish Peroxidase, TMB = 3,3',5,5'-tetramethylbenzidine) were conducted. The results indicated a 17% faster diffusion kinetic for FhuA Δ1-159 Exp as compared to FhuA Δ1-159, well correlated to the expected channel surface area increase of ~16%.

Conclusion

In this study using a simple "semi rational" approach the FhuA Δ1-159 diameter was enlarged. By combining the actual results with the previous ones on the FhuA Δ1-159 lengthening a new set of synthetic nanochannels with desired lengths and diameters can be produced, broadening the FhuA Δ1-159 applications. As large scale protein production is possible our approach can give a contribution to nanochannel industrial applications.
Effects of mesenchymal stem cells on matrix metalloproteinase synthesis in cardiac fibroblasts
Authors: Wang Yaping , Hu Xinyang , Xie Xiaojie , He Aina , Liu Xianbao , Wang Jian-an
Published: August 2011

Mesenchymal stem cell (MSC) transplantation has been known to decrease matrix metalloproteinase (MMP) synthesis in myocardium after myocardial infarction (MI) and improve ventricular remodeling; however, the underlying mechanisms are unclear. This study investigated the effects of MSC on MMP synthesis in cardiac fibroblasts (CFs) through paracrine actions. CFs were cultured under hypoxic (0.5% pO2) conditions for 24 h before co-culture with MSCs or hypoxia-preconditioned MSCs (H-MSCs) in transwell plates. CFs and MSCs/H-MSCs shared a medium with or without erythropoietin (EPO) neutralizing antibody (EPOAb) or EPO-soluble receptor (EPOsR). The results showed that protein expression and activity of MMP-2 and membrane type 1-MMP, but not MMP-9, in CFs were significantly increased in response to hypoxia and decreased after co-culture with MSCs or H-MSCs. Hypoxia up-regulated phosphorylation of extracellular signal-regulated kinase (ERK)1/2 of CFs which was down-regulated after CFs' co-culture with MSCs. Tissue inhibitors of metalloproteinases-1 (TIMP-1) in CFs was decreased after hypoxia and increased when co-cultured with MSCs or H-MSCs. Exogenous EPOAb or EPOsR partially inhibited MSCs' effect on MMP-2 expression and activity in CFs. The present findings suggested that MSCs influence MMP/TIMP expression in CFs via the ERK1/2 pathway and EPO acts as a key factor in the paracrine actions of MSCs.
Chitosan oligosaccharide decreases very-low-density lipoprotein triglyceride and increases high-density lipoprotein cholesterol in high-fat-diet-fed rats
Authors: Wang Daxin , Han Jiju , Yu Yang , Li Xueping , Wang Yun , Tian Hua , Guo Shoudong , Jin Shiguang , Luo Tian , Qin Shucun
Published: August 2011

It is well known that chitosan has beneficial lipid-regulating effects, but it remains unknown whether chitosan oligosaccharide (COS), the chitosan degradation product, has the same lipid benefits. High-fat-diet-fed Wistar rats were administrated with COS by gastric gavage for three weeks. The effects of COS on lipids, lipoprotein components and lipid metabolism related protein activities were investigated. Plasma lipids level assays by an enzyme method showed that COS decreased triglyceride (TG) by 29–31%, and increased high-density lipoprotein (HDL) cholesterol by 8–11%, but did not affect low-density lipoprotein (LDL) cholesterol. Lipid distribution analysis through fast protein liquid chromatography indicated that COS significantly decreased TG content distributed in very-low-density lipoprotein (VLDL)/LDL fractions but increased cholesterol content in HDL fractions. Apolipoprotein analysis through plasma ultracentrifugation and sodium dodecyl sulfate polyacrylamide gel electrophoresis displayed that COS decreased apolipoprotein B-100 of LDL and increased apolipoprotein E of LDL and apolipoprotein B-100 of VLDL, but did not change apoA-I content of HDL particles. Lipoprotein formation associated protein determination showed that COS also increased plasma activity of lecithin cholesterol acyl transferase but not phospholipid transfer protein. The present study suggests that COS may play a beneficial role in plasma lipid regulation of rats with dyslipidemia induced by high-fat diet. The COS-decreased VLDL/LDL TG and -enhanced HDL cholesterol may be related to the upregulated activity of lecithin cholesterol acyl transferase.
The accuracy of diagnostic tests for GH deficiency in adults: a systematic review and meta-analysis
Authors: Hazem Ahmad , Elamin Mohamed B , Malaga German , Bancos Irina , Prevost Yolanda , Zeballos-Palacios Claudia , Velasquez Edgar R , Erwin Patricia J , Natt Neena , Montori Victor M , Murad Mohammad Hassan
Published: August 2011

Context

The diagnostic accuracy of tests used to diagnose GH deficiency (GHD) in adults is unclear.

Objective

We conducted a systematic review and meta-analysis of studies that provided data on the available diagnostic tests.

Data sources

We searched electronic databases (MEDLINE, EMBASE, Cochrane CENTRAL, Web of Sciences, and Scopus) through April 2011.

Study selection

Review of reference lists and contact with experts identified additional candidate studies. Reviewers, working independently and in duplicate, determined study eligibility.

Data extraction

Reviewers, working independently and in duplicate, determined the methodological quality of studies and collected descriptive, quality, and outcome data.

Data synthesis

Twenty-three studies provided diagnostic accuracy data; none provided patient outcome data. Studies had fair methodological quality, used several reference standards, and included over 1100 patients. Several tests based on direct or indirect stimulation of GH release were associated with good diagnostic accuracy, although most were assessed in one or two studies decreasing the strength of inference due to small sample size. Serum levels of GH or IGF1 had low diagnostic accuracy. Pooled sensitivity and specificity of the two most commonly used stimulation tests were found to be 95 and 89% for the insulin tolerance test and 73 and 81% for the GHRH+arginine test respectively. Meta-analytic estimates for accuracy were associated with substantial heterogeneity.

Conclusion

Several tests with reasonable diagnostic accuracy are available for the diagnosis of GHD in adults. The supporting evidence, however, is at high risk of bias (due to heterogeneity, methodological limitations, and imprecision).
Desenvolvimento de Oligonychus ilicis em Coffea canephora sob diferentes temperaturas
Authors: Polanczyk Ricardo Antonio , Celestino Flávio Neves , Ferreira Lígia Souza , Melo Débora Ferreira , Bestete Luziani Rezende , Franco Cláudio Roberto , Pratissoli Dirceu
Published: August 2011

Oligonychus ilicis (McGregor) (Acari) (Tetranychidae) é uma das principais pragas de Coffea canephora Pierre & Froehner. Neste trabalho, avaliou-se o efeito de diferentes temperaturas no desenvolvimento desse ácaro-vermelho em folhas de C. canephora, em laboratório. Confinaram-se 80 fêmeas em 40 arenas, constituídas de disco foliar de 4 cm, para oviposição nas temperaturas de 21, 24, 27, 30 e 33 ºC. Foram selecionados ao acaso pelo menos dois ovos para avaliar o desenvolvimento embrionário. Após a eclosão da larva, foram realizadas avaliações a cada 12 horas para obtenção da duração e sobrevivência larval. Para avaliar a longevidade foi transferido um ácaro macho da criação para as arenas com uma fêmea para acasalamento. O limite térmico de desenvolvimento inferior e a constante térmica foram determinados para a duração do desenvolvimento de ovo a adulto. O tempo de desenvolvimento das fases imaturas diminuiu com o aumento da temperatura. As fases de ovo, larva, protocrisálida, protoninfa, deutocrisálida, deutoninfa e teleiocrisálida variaram, respectivamente, de 10,4 a 4,3; 2,4 a 1,2; 2,0 a 1,0; 2,3 a 1,2; 1,9 a 1,0; 3,0 a 1,5 e 2,3 a 1,0 dias. O aumento da temperatura afetou o período de desenvolvimento, reduzindo a duração de ovo-adulto e a longevidade. O limite térmico inferior foi de 9,0 ºC para o período de ovo-adulto e constante térmica de 256,4 graus-dias. Em condições de laboratório, a faixa de temperatura que favorece o desenvolvimento do ácaro em C. canephora foi de 24 a 30 ºC. O limite térmico inferior não é limitante para ocorrência de O. ilicis em áreas cultivadas com C. canephora no estado do Espírito Santo.
Variabilidade temporal da evapotranspiração real e da razão entre evapotranspiração real e potencial em Campinas, Estado de São Paulo
Authors: Blain Gabriel Constantino , Pires Regina Clélia de Matos
Published: August 2011

O objetivo do trabalho foi caracterizar a variabilidade temporal de séries decendiais de evapotranspiração real (ETR) e da razão entre a evapotranspiração real e potencial (ETR/ETP) na localidade de Campinas, Estado de São Paulo, no período de 1948-2008, considerando três valores de capacidade de água disponível (CAD): 50, 100 e 150 mm. Utilizando a função autocorrelação (acf) verificou-se presença de significativa persistência temporal nos valores de ETR e de ETR/ETP. A aplicação da acf também permitiu inferir que essa persistência eleva-se com o aumento do valor da CAD. A análise espectral indicou queda nos picos de potência dessas duas variáveis a partir de 1976. A influência do El Nino/oscilação sul nas séries de ETR e ETR/ETP não é conclusiva. A aplicação do método Sazonal de Mann-Kendall indicou, em janeiro, maio, julho, setembro, novembro e dezembro, tendências de elevação na ETR. A ETR/ETP foi pouco sensível as elevações temporais observadas nas séries de ETP.
Diversidade e flutuação populacional de ácaros (Acari) em amora-preta (Rubus fruticosus, Rosaceae) no estado do Rio Grande do Sul, Brasil
Authors: Marchetti Márla Maria , Ferla Noeli Juarez
Published: August 2011

Ácaros das famílias Eriophyidae, Tarsonemidae e Tetranychidae são citados como de importância econômica na cultura de amora-preta (Rubus fruticosus, Rosaceae), framboesa e outras frutas pequenas. Este estudo foi conduzido de novembro de 2001 a outubro de 2003 nas cultivares Brazos, Caigangue e Tupy no município de Ilópolis, Rio Grande do Sul, com o objetivo de conhecer a acarofauna e sua dinâmica populacional em amora-preta. Foram coletados 36.094 ácaros pertencentes a 11 famílias. A maioria dos ácaros coletados pertence às famílias Diptilomiopidae (80,9%) e Tetranychidae (13,9%), compostas por espécies fitófagas. Chakrabartiella sp. (Diptilomiopidae), foi a espécie mais abundante, seguida por Neotetranychus asper Feres & Flechtmann, 2000 (Tetranychidae). Stigmaeidae (2,1%) e Phytoseiidae (0,4%) foram os ácaros predadores mais comuns, sendo Agistemus brasiliensis Matioli, Ueckermann & Oliveira, 2002 (Stigmaeidae) e Typhlodromalus aripo DeLeon, 1967 (Phytoseiidae), as espécies de predadores mais abundantes.
Determinação da maturidade sexual de Ucides cordatus (Crustacea, Brachyura, Ucididae) em duas áreas de manguezal do litoral sul de Pernambuco, Brasil
Authors: Castiglioni Daniela da S , Coelho Petrônio A
Published: August 2011

Este estudo foi desenvolvido com o objetivo de determinar o tamanho da maturidade morfológica e fisiológica de machos e fêmeas em duas populações de Ucides cordatus (Linnaeus, 1763) de Tamandaré, Pernambuco, Brasil. Os caranguejos foram coletados mensalmente (abril/2008 a março/2009) nos manguezais dos rios Ariquindá e Mamucabas, por um catador, através da técnica de braceamento, durante a maré baixa em três áreas distintas de 25 m² cada. Os caranguejos capturados foram separados por sexo e medidos (largura da carapaça, comprimento do própodo do quelípodo dos machos e largura do 5º somito abdominal das fêmeas). Além disso, os caranguejos foram caracterizados em relação ao estágio de desenvolvimento gonadal. Os caranguejos com gônadas imaturas e rudimentares foram considerados jovens, enquanto os demais foram classificados como adultos (gônada em desenvolvimento, desenvolvida, avançada ou esgotada). O tamanho da largura da carapaça no qual 50% da população de U. cordatus foi considerada madura morfologicamente foi de 38,0 mm (machos) e 35,4 mm (fêmeas) em Ariquindá, enquanto para Mamucabas estes valores foram de 37,3 e 32,9 mm, respectivamente. Na determinação da maturidade sexual fisiológica, os machos e fêmeas de Ariquindá foram considerados maduros com 38,5 e 37,8 mm, respectivamente, enquanto em Mamucabas os tamanhos obtidos foram de 36,2 e 35,8 mm. A maturidade morfológica dos machos ocorreu com tamanho superior ao das fêmeas, provavelmente devido ao seu maior investimento em crescimento somático, enquanto as fêmeas investem mais no processo reprodutivo. Os caranguejos provenientes do manguezal de Mamucabas atingiram a maturidade sexual com tamanhos inferiores aos de Ariquindá, provavelmente devido ao maior impacto verificado para este manguezal.
Diálogos da psicologia com a enfermagem em tempos de transição paradigmática
Authors: Corradi-Webster Clarissa Mendonça , Carvalho Ana Maria Pimenta
Published: August 2011

No momento atual, passamos por transição paradigmática em relação a como compreendemos Saúde e Cuidado. O modelo biomédico vem sendo substituído por uma visão integral do homem e, na assistência, privilegia-se a promoção de saúde e a prevenção de agravos. Entretanto, o discurso da responsabilidade pessoal pela saúde pode construir nos usuários sentimentos como culpa, vergonha, medo e paranóia, e nos profissionais, impotência e frustração. Estes sentimentos atrapalham a relação de vínculo e, com isto, a eficácia do atendimento. O objetivo deste estudo, de natureza teórica, é propor um diálogo entre a Psicologia, com sensibilidade construcionista social, e a Enfermagem, a fim de analisar as possibilidades de cuidado construídas a partir deste. Como alternativa ao discurso da responsabilidade pessoal, propõe-se a responsabilidade relacional e a compreensão de saúde e cuidado dentro do tempo longo, do tempo vivido e do tempo curto.
O novo romance egípcio: transformação urbana e forma narrativa
Authors: Hafez Sabry
Published: August 2011

Os trabalhos da nova geração de escritores do Cairo compartilham um conjunto de características narrativas peculiares, envolvendo tanto uma ruptura com as formas modernistas e realistas anteriores quanto uma transformação das regras de referências pelas quais o texto se relaciona com o mundo externo. O artigo procura mostrar que, independente de onde suas tramas sejam ambientadas, essas obras compartilham homologias formais com as crescentes favelas do Cairo.
Era uma vez dois irmãos...
Authors: Mazzari Marcus V.
Published: August 2011

Este ensaio aborda a narrativa Grimms Wörter [Palavras de Grimm], publicada por Günter Grass em agosto de 2010, pouco antes de completar 83 anos. Wilhelm e Jacob Grimm são suas personagens principais e o tema gira em torno dos esforços despendidos pelos irmãos para elaborar um grande dicionário da língua alemã, concluí-do apenas em 1961 com a publicação do 32º volume. Organizando os capítulos do livro (e também a estrutura narrativa) pelas letras do alfabeto, Grass presta comovida homenagem ao trabalho filológico de Wilhelm e Jacob Grimm, ao mesmo tempo que faz uma declaração de amor à língua alemã. Ao mostrar ainda de que modo 123 anos da história alemã se refletem na intrincada gênese do dicionário, o narrador toma episódios fundamentais da vida dos irmãos Grimm como ensejo para reconstituir estações de sua própria biografia política e artística. Na perspectiva desse entrelaçamento de trajetórias, o ensaio privilegia uma passagem do capítulo dedicado à letra "D" (de Däumling: Pequeno Polegar, em alemão) para ressaltar a influência que um dos mais célebres heróis dos irmãos Grimm teve sobre a concepção de Oskar Matzerath, o eu narrador do romance O tambor de lata. Estabelece-se assim um arco entre a narrativa Grimms Wörter e o romance que proporcionou notoriedade mundial ao jovem Günter Grass.