bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk factors for traumatic and non-traumatic lower limb pain among preadolescents: a population-based study of Finnish schoolchildren
Authors: El-Metwally Ashraf , Salminen Jouko J , Auvinen Anssi , Kautiainen Hannu , Mikkelsson Marja
Published: January 2006

Background

The child's lower limb is the most commonly reported musculoskeletal location with pain and also the most commonly injured site in sports. Some potential risk factors have been studied, but the results are inconsistent. We hypothesized that distinction of traumatic from non-traumatic pain would provide a clearer picture of these factors. The aim of this study is to assess factors associated with lower extremity pain and its impact on preadolescents in a population-based cohort.

Methods

A structured pain questionnaire was completed by 1756 schoolchildren of third and fifth grades to assess musculoskeletal pain, psychosomatic symptoms, subjective disabilities, school absence and frequency of exercise. In addition, hypermobility and physical fitness were measured.

Results

The knee was the most common site of pain followed by the ankle-foot and thigh. Of the children who reported pain in their lower extremity, approximately 70% reported at least one disability and 19 % reported school absence attributed to their pain during the previous three-month period. Children with traumatic pain had a higher subjective disability index than those with non-traumatic pain (P = 0.02). Age less than 11 years, headache, abdominal pain, depressive feelings, day tiredness, and vigorous exercise were more common in children with lower limb pain than those free of it. In the stratified analysis, younger age was related to both traumatic and non-traumatic pain groups. Vigorous exercise was positively associated with traumatic pain, while subjects with non-traumatic pain had more frequent psychosomatic symptoms.

Conclusion

Risk factors and consequences of traumatic and non-traumatic lower limb pain are not similar. Traumatic lower limb pain is associated with practicing vigorous exercise and high level of physical fitness, while non-traumatic pain is more correlated with psychosomatic symptoms. These differences might be one of the reasons for the discrepancy of previous research conclusions. The two conditions need to be treated as different disorders in future studies.
Analysis of a marine phototrophic biofilm by confocal laser scanning microscopy using the new image quantification software PHLIP
Authors: Mueller Lukas N , de Brouwer Jody FC , Almeida Jonas S , Stal Lucas J , Xavier João B
Published: January 2006

Background

Confocal laser scanning microscopy (CLSM) is the method of choice to study interfacial biofilms and acquires time-resolved three-dimensional data of the biofilm structure. CLSM can be used in a multi-channel modus where the different channels map individual biofilm components. This communication presents a novel image quantification tool, PHLIP, for the quantitative analysis of large amounts of multichannel CLSM data in an automated way. PHLIP can be freely downloaded from http://phlip.sourceforge.net

Results

PHLIP is an open source public license Matlab toolbox that includes functions for CLSM imaging data handling and ten image analysis operations describing various aspects of biofilm morphology. The use of PHLIP is here demonstrated by a study of the development of a natural marine phototrophic biofilm. It is shown how the examination of the individual biofilm components using the multi-channel capability of PHLIP allowed the description of the dynamic spatial and temporal separation of diatoms, bacteria and organic and inorganic matter during the shift from a bacteria-dominated to a diatom-dominated phototrophic biofilm. Reflection images and weight measurements complementing the PHLIP analyses suggest that a large part of the biofilm mass consisted of inorganic mineral material.

Conclusion

The presented case study reveals new insight into the temporal development of a phototrophic biofilm where multi-channel imaging allowed to parallel monitor the dynamics of the individual biofilm components over time. This application of PHLIP presents the power of biofilm image analysis by multi-channel CLSM software and demonstrates the importance of PHLIP for the scientific community as a flexible and extendable image analysis platform for automated image processing.
Changes in caseload and the potential impact on surgical training: a retrospective review of one hospital's experience
Authors: Varley Iain , Keir James , Fagg Phillip
Published: January 2006

Background

Recent reforms to the training grades have provoked debate about both quality and quantity of training. The bulk of previous research into this area has been qualitative, and little is known about the quantity of training opportunities. This study aimed to determine if the number of elective operations available to trainees was stable.

Methods

The number of elective procedures carried out in each surgical specialty (General & Vascular Surgery, Urology, Orthopaedics, ENT) in a large district general hospital was analysed in 6 month periods and adjusted for the number of basic surgical trainees in each specialty. In order to allow comparison between specialties, results for each 6 month period were calculated as a percentage of those for the first period.

Results

The number of elective operations available per trainee fell in 3 of the 4 specialties, with a rise in Orthopaedics. Overall, the number of operations available to each trainee was 56% of that less than a decade ago.

Conclusion

The number of operations available in a conventional hospital setting is decreasing. Introduction of the Modernising Medical Careers reforms must take account of this if they are to succeed in improving the quality of surgical training.
IT-adoption and the interaction of task, technology and individuals: a fit framework and a case study
Authors: Ammenwerth Elske , Iller Carola , Mahler Cornelia
Published: January 2006

Background

Factors of IT adoption have largely been discussed in the literature. However, existing frameworks (such as TAM or TTF) are failing to include one important aspect, the interaction between user and task.

Method

Based on a literature study and a case study, we developed the FITT framework to help analyse the socio-organisational-technical factors that influence IT adoption in a health care setting.

Results

Our FITT framework ("F it between I ndividuals, T ask and T echnology") is based on the idea that IT adoption in a clinical environment depends on the fit between the attributes of the individual users (e.g. computer anxiety, motivation), attributes of the technology (e.g. usability, functionality, performance), and attributes of the clinical tasks and processes (e.g. organisation, task complexity). We used this framework in the retrospective analysis of a three-year case study, describing the adoption of a nursing documentation system in various departments in a German University Hospital. We will show how the FITT framework helped analyzing the process of IT adoption during an IT implementation: we were able to describe every found IT adoption problem with regard to the three fit dimensions, and any intervention on the fit can be described with regard to the three objects of the FITT framework (individual, task, technology). We also derive facilitators and barriers to IT adoption of clinical information systems.

Conclusion

This work should support a better understanding of the reasons for IT adoption failures and therefore enable better prepared and more successful IT introduction projects. We will discuss, however, that from a more epistemological point of view, it may be difficult or even impossible to analyse the complex and interacting factors that predict success or failure of IT projects in a socio-technical environment.
Profit and loss analysis for an intensive care unit (ICU) in Japan: a tool for strategic management
Authors: Cao Pengyu , Toyabe Shin-ichi , Abe Toshikazu , Akazawa Kouhei
Published: January 2006

Background

Accurate cost estimate and a profit and loss analysis are necessary for health care practice. We performed an actual financial analysis for an intensive care unit (ICU) of a university hospital in Japan, and tried to discuss the health care policy and resource allocation decisions that have an impact on critical intensive care.

Methods

The costs were estimated by a department level activity based costing method, and the profit and loss analysis was based on a break-even point analysis. The data used included the monthly number of patients, the revenue, and the direct and indirect costs of the ICU in 2003.

Results

The results of this analysis showed that the total costs of US$ 2,678,052 of the ICU were mainly incurred due to direct costs of 88.8%. On the other hand, the actual annual total patient days in the ICU were 1,549 which resulted in revenues of US$ 2,295,044. However, it was determined that the ICU required at least 1,986 patient days within one fiscal year based on a break-even point analysis. As a result, an annual deficit of US$ 383,008 has occurred in the ICU.

Conclusion

These methods are useful for determining the profits or losses for the ICU practice, and how to evaluate and to improve it. In this study, the results indicate that most ICUs in Japanese hospitals may not be profitable at the present time. As a result, in order to increase the income to make up for this deficit, an increase of 437 patient days in the ICU in one fiscal year is needed, and the number of patients admitted to the ICU should thus be increased without increasing the number of beds or staff members. Increasing the number of patients referred from cooperating hospitals and clinics therefore appears to be the best strategy for achieving these goals.
Overcoming inherent problems of preference-based techniques for measuring health benefits: An empirical study in the context of kidney transplantation
Authors: Kontodimopoulos Nick , Niakas Dimitris
Published: January 2006

Background

Economic valuations of health care programs often require using patients as subjects, implying that research methodology should conform to the surrounding social, cultural and ethical context. The significance of patients' opinions in health care decisions has been well defined but in Greece, and perhaps elsewhere, clinicians remain skeptical. The purpose of this study was to investigate, for the first time in Greece, the feasibility of measuring preference-based health-state utilities and willingness to pay and to determine the context-based adaptations required to overcome inherent elicitation problems.

Methods

A survey including a time trade-off (TTO), a standard gamble (SG), and two willingness-to-pay (WTP) questions was self-administered to a homogenous group of 606 end stage renal disease patients in 24 dialysis facilities throughout Greece and the overall response rate was 78.5%. Typical elicitation methods were adapted to overcome methodological problems such as subjective life expectancy and question framing. Spearman's correlation coefficients were calculated between utilities and WTP and parametric tests (independent samples t-test and ANOVA) examined score differences as a result of demographic and clinical factors.

Results

Mean health-state utilities were 72.56 (TTO) and 91.06 (SG) and these were statistically significantly different (P < 0.0005). Significant correlations, in the expected directions, were observed between TTO – SG, TTO – WTP and SG – WTP (P < 0.01). High ceiling effects were observed in the TTO and SG methods indicating patients' adversity to risk and unwillingness to trade-off life years. Higher WTP was observed from younger patients (P < 0.0005), males (P < 0.05), higher education levels (P < 0.01), single (P < 0.0005) and employed (P < 0.005).

Conclusion

This study demonstrated, to a fair extent, that adapting research methods to context-based particularities does not necessarily compromise results and should be considered in situations where standard methods cannot be applied. On the other hand, it is emphasized that the results from this study are preliminary and should be interpreted cautiously until further research demonstrates the practicality, reliability and validity of alternative measurement approaches.
Biomechanical analysis of rollator walking
Authors: Alkjær Tine , Larsen Peter K , Pedersen Gitte , Nielsen Linda H , Simonsen Erik B
Published: January 2006

Background

The rollator is a very popular walking aid. However, knowledge about how a rollator affects the walking patterns is limited. Thus, the purpose of the study was to investigate the biomechanical effects of walking with and without a rollator on the walking pattern in healthy subjects.

Methods

The walking pattern during walking with and without rollator was analyzed using a three-dimensional inverse dynamics method. Sagittal joint dynamics and kinematics of the ankle, knee and hip were calculated. In addition, hip joint dynamics and kinematics in the frontal plane were calculated. Seven healthy women participated in the study.

Results

The hip was more flexed while the knee and ankle joints were less flexed/dorsiflexed during rollator walking. The ROM of the ankle and knee joints was reduced during rollator-walking. Rollator-walking caused a reduction in the knee extensor moment by 50% when compared to normal walking. The ankle plantarflexor and hip abductor moments were smaller when walking with a rollator. In contrast, the angular impulse of the hip extensors was significantly increased during rollator-walking.

Conclusion

Walking with a rollator unloaded the ankle and especially the knee extensors, increased the hip flexion and thus the contribution of hip extensors to produce movement. Thus, rollator walking did not result in an overall unloading of the muscles and joints of the lower extremities. However, the long-term effect of rollator walking is unknown and further investigation in this field is needed.
Spatial analysis of campylobacter infection in the Canadian province of Manitoba
Authors: Green Chris G , Krause Dennis O , Wylie John L
Published: January 2006

Background

The study describes population level variations in campylobacter incidence within the Canadian province of Manitoba, and the relationship to sociodemographic and landscape related characteristics. Using data derived from the Manitoba Health Public Health Branch communicable disease surveillance database, the study applied a number of spatial and ecological techniques to visualize, explore and model campylobacter incidence for the years 1996 to 2004. Analytical techniques used in the study included spatial smoothing, the spatial scan statistic, the Gini coefficient, and Poisson regression analysis.

Results

The study demonstrated marked and statistically significant geographic variability in the rates of campylobacter incidence in Manitoba.. The incidence of campylobacter was observed to be significantly higher in populations living in rural and agricultural areas of the province, with the highest rates occurring in populations living in proximity to high densities of farm animals (cows, pigs, chickens). The study also observed that the age specific pattern of campylobacter incidence in rural Manitoba was very different than the urban pattern, with the incidence rate in the 0–4 year age group seven times higher in rural Manitoba than in the City of Winnipeg.

Conclusion

The study demonstrates the value of a deploying a diverse set of spatial techniques to better understand the dynamics of an enteric disease such as campylobacter infection. The study concludes that there may be three distinct mechanisms for the transmission of campylobacter in Manitoba which are operating simultaneously. These include broad population exposure to a centralized food system endemically infected with the campylobacter organism, exposure to local level factors such as farm animals or contaminated water, and exposure to campylobacter infection through foreign travel.
Defining localities of inadequate treatment for childhood asthma: A GIS approach
Authors: Peled Ronit , Reuveni Haim , Pliskin Joseph S , Benenson Itzhak , Hatna Erez , Tal Asher
Published: January 2006

Background

The use of Geographic Information Systems (GIS) has great potential for the management of chronic disease and the analysis of clinical and administrative health care data. Asthma is a chronic disease associated with substantial morbidity, mortality, and health care use. Epidemiologic data from all over the world show an increasing prevalence of asthma morbidity and mortality despite the availability of effective treatment. These facts led to the emergence of strategies developed to improve the quality of asthma care.

The objective

To develop an efficient tool for quality assurance and chronic disease management using a Geographic Information System (GIS).

Geographic location

The southern region of Israel. January 1998 – October 2000.

Databases

Administrative claims data of the largest HMO in Israel: drug dispensing registry, demographic data, Emergency Room visits, and hospitalization data bases.

Methods

We created a list of six markers for inadequate pharmaceutical treatment of childhood asthma from the Israeli clinical guidelines. We used this list to search the drug dispensing registry to identify asthmatic children who received inadequate treatment and to assess their health care utilization and bad outcomes: emergency room visits and hospitalizations. Using GIS we created thematic maps on which we located the clinics with a high percentage of children for whom the treatment provided was not in adherence with the clinical guidelines.

Results

81% of the children were found to have at least one marker for inadequate treatment; 17.5% were found to have more than one marker. Children with markers were found to have statistically significant higher rates of Emergency Room visits, hospitalizations and longer length of stay in hospital compared with children without markers. The maps show in a robust way which clinics provided treatment not in accord with the clinical guidelines. Those clinics have high rates of Emergency Room visits, hospitalizations and length of stay.

Conclusion

Integration of clinical guidelines, administrative data and GIS can create an efficient interface between administrative and clinical information. This tool can be used for allocating sites for quality assurance interventions.
BRAF mutations are associated with distinctive clinical, pathological and molecular features of colorectal cancer independently of microsatellite instability status
Authors: Qi Li Wei , Kawakami Kazuyuki , Ruszkiewicz Andrew , Bennett Graeme , Moore James , Iacopetta Barry
Published: January 2006

Background

BRAF is a member of RAF family of serine/threonine kinases and mediates cellular responses to growth signals through the RAS-RAF-MAP kinase pathway. Activating mutations in BRAF have recently been found in about 10% of colorectal cancers, with the vast majority being a V600E hotspot mutation. The aim of the present study was to evaluate the clinical, pathological and molecular phenotype of colorectal tumors with BRAF mutations.

Results

Mutations in BRAF were identified in 8% (23/275) of colorectal cancers. They were 5–10-fold more frequent in tumors with infiltrating lymphocytes, location in the proximal colon, poor histological grade and mucinous appearance (P < 0.002 for each). Tumors with BRAF mutation were also 10-fold more likely to show microsatellite instability and frequent DNA methylation (P < 0.0001) compared to tumors without this mutation. The characteristic morphological features of tumors with BRAF mutation (infiltrating lymphocytes, poor grade, mucinous) remained after stratification according to microsatellite instability and methylator phenotypes. Mutations in BRAF were mutually exclusive with mutations in KRAS but showed no clear association with the presence of TP53 mutation.

Conclusion

BRAF mutation identifies a colorectal cancer subgroup with distinctive phenotypic properties independent of microsatellite instability status and thus could be a valuable marker for studies into the clinical properties of these tumors.
Hypoxia-inducible factor-1α polymorphisms and TSC1/2 mutations are complementary in head and neck cancers
Authors: Hebert Carla , Norris Kathleen , Parashar Pallavi , Ord Robert A , Nikitakis Nikolaos G , Sauk John J
Published: January 2006

Background

Polymorphisms or mutations in hypoxia inducible factor-1 alpha (HIF-1alpha) that increases its activity and stability under normoxia have recently been identified. Likewise, disruption of the TSC1/TSC2 complex through loss of TSC1 or TSC2 has been shown to result in abnormal accumulation of HIF-1α. Here, we investigate the novel polymorphisms in exon 12, that approximate the oxygen-dependent degradation domain of HIF-1alpha in five cell lines and 28 patients with oral squamous carcinomas. Moreover, we assess for the presence of polymorphisms and mutations in TSC1 and TSC2, to ascertain if dysregulation of such might complement HIF-1alpha expression.

Results

Denaturing high pressure liquid chromatography (DHPLC) analysis on PCR fragments in exon 12 of HIF-1alpha from 28 patients with OSCC revealed that 6 of 28 patients had mismatched heteroduplex patterns. Genomic DNA was extracted from peripheral blood leukocytes and direct sequencing showed that in 5 of the six cases these changes represented polymorphisms while, one case was a somatic mutation. Analyses of TSC1 and TSC2 revealed heteroduplexes in exons: TSC1 exon 17; TSC2 exons 36,40, and 41. The relative levels of HIF-1alpha were significantly greater for tumors possessing a HIF-1alpha polymorphism or mutation within exon 12, whereas tumors possessing a deletion or polymorphism in TSC1/TSC2 displayed a trend for higher levels of HIF-1alpha. Western blot analyses for HIF-1alpha, TSC1 and TSC2 in five SCC cell lines revealed high levels of HIF-1alpha in SCC cells possessing TSC1 and/or TSC2 mutations. Wild-type TSC2 cells targeted with siRNA to TSC2 exhibited increased levels of HIF-1alpha. Transfection of a HIF-1alpha mutant produced higher levels of HIF-1alpha in TSC1/TSC2 mutant cell lines than in wild type cells. TSC1/TSC2 mutant cell lines administered Rapamycin blocked S6 phorphorylation and diminished the levels of HIF-1alpha to those observed in cell lines with wild type TSC1/TSC2.

Conclusion

Dysregulation of the TSC1/TSC2 complex by mutation compliments HIF-1α polymorphisms in the expression of HIF-1alpha in SCC of the head and neck, and may provide biomarkers to predict responses to specific therapies and overall disease prognosis.
The tumor suppressor DAL-1/4.1B and protein methylation cooperate in inducing apoptosis in MCF-7 breast cancer cells
Authors: Jiang Wei , Newsham Irene F
Published: January 2006

Background

DAL-1 (Differentially Expressed in Adenocarcinoma of the Lung)/4.1B is a member of the protein 4.1 superfamily that has been shown to suppress growth in lung, breast and brain tumor cells. In the case of the caspase-3 deficient MCF-7 breast cancer cells, this growth suppression has been shown to be partially mediated by the induction of apoptosis. However the exact mechanism of action of DAL-1/4.1B is unknown. Recently, protein arginine N-methyltransferase 3 (PRMT3) was identified as a DAL-1/4.1B interacting protein. Protein arginine methyltransferases (PRMTs) posttranslationally methylate the arginine residues of proteins, a modification which has been implicated in the regulation of multiple cellular processes including nuclear-cytoplasmic transport, signal transduction, and transcription.

Results

To investigate the role of protein methylation in cell death induced by DAL-1/4.1B, DAL-1/4.1B-inducible MCF-7 cells were examined for apoptosis and caspase activation in the absence and presence of the protein methylation inhibitor adenosine dialdehyde (AdOX). Flow cytometry analysis revealed that apoptosis was primarily associated with the activation of caspase 8, and inhibition of this activation blocked the ability of DAL-1/4.1B to induce cell death.

Conclusion

These results suggest that protein methylation cooperates with DAL-1/4.1B-associated caspase 8-specific activation to induce apoptosis in breast cancer cells.
Mining literature for a comprehensive pathway analysis: A case study for retrieval of homocysteine related genes for genetic and epigenetic studies
Authors: Sharma Priyanka , Senthilkumar RD , Brahmachari Vani , Sundaramoorthy Elayanambi , Mahajan Anubha , Sharma Amitabh , Sengupta Shantanu
Published: January 2006

Homocysteine is an independent risk factor for cardiovascular diseases. It is also known to be associated with a variety of complex disorders. While there are a large number of independent studies implicating homocysteine in isolated pathways, the mechanism of homocysteine induced adverse effects are not clear. Homocysteine-induced modulation of gene expression through alteration of methylation status or by hitherto unknown mechanisms is predicted to lead to several pathological conditions either directly or indirectly. In the present manuscript, using literature mining approach, we have identified the genes that are modulated directly or indirectly by an elevated level of homocysteine. These genes were then placed in appropriate pathways in an attempt to understand the molecular basis of homocysteine induced complex disorders and to provide a resource for selection of genes for polymorphism screening and analysis of mutations as well as epigenetic modifications in relation to hyperhomocysteinemia. We have identified 135 genes in 1137 abstracts that either modulate the levels of homocysteine or are modulated by elevated levels of homocysteine. Mapping the genes to their respective pathways revealed that an elevated level of homocysteine leads to the atherosclerosis either by directly affecting lipid metabolism and transport or via oxidative stress and/or Endoplasmic Reticulum (ER) stress. Elevated levels of homocysteine also decreases the bioavailability of nitric oxide and modulates the levels of other metabolites including S-adenosyl methionine and S-adenosyl homocysteine which may result in cardiovascular or neurological disorders. The ER stress emerges as the common pathway that relates to apoptosis, atherosclerosis and neurological disorders and is modulated by levels of homocysteine. The comprehensive network collated has lead to the identification of genes that are modulated by homocysteine indicating that homocysteine exerts its effect not only through modulating the substrate levels for various catalytic processes but also through regulation of expression of genes involved in complex diseases.
Increase of free Mg2+in the skeletal muscle of chronic fatigue syndrome patients
Authors: McCully Kevin K , Malucelli Emil , Iotti Stefano
Published: January 2006

In a previous study we evaluated muscle blood flow and muscle metabolism in patients diagnosed with chronic fatigue syndrome (CFS). To better understand muscle metabolism in CFS, we re-evaluated our data to calculate free Magnesium levels in skeletal muscle. Magnesium is an essential cofactor in a number of cell processes. A total of 20 CFS patients and 11 controls were evaluated. Phosphorus magnetic resonance spectroscopy from the medial gastrocnemius muscle was used to calculate free Mg2+ from the concentrations and chemical shifts of Pi, PCr, and beta ATP peaks. CFS patients had higher magnesium levels in their muscles relative to controls (0.47 + 0.07 vs 0.36 + 0.06 mM, P < 0.01), although there was no difference in the rate of phosphocreatine recovery in these subjects, as reported earlier. This finding was not associated with abnormal oxidative metabolism as measured by the rate of recovery of phosphocreatine after exercise. In summary, calculation of free Mg2+ levels from previous data showed CFS patients had higher resting free Mg2+ levels compared to sedentary controls.
Sex differences in the rate of fatigue development and recovery
Authors: Albert WJ , Wrigley AT , McLean RB , Sleivert GG
Published: January 2006

Background

Many musculoskeltal injuries in the workplace have been attributed to the repetitive loading of muscle and soft tissues. It is not disputed that muscular fatigue is a risk factor for musculoskeltal injury, however the disparity between gender with respect to muscular fatigability and rate of recovery is not well understood. Current health and safety guidelines do not account for sex differences in fatiguability and may be predisposing one gender to greater risk. The purpose of this study was to quantify the sex differences in fatigue development and recovery rate of lower and upper body musculature after repeated bouts of sustained isometric contractions.

Methods

Twenty-seven healthy males (n = 12) and females (n = 15) underwent bilateral localized fatigue of either the knee extensors (male: n = 8; female: n = 8), elbow flexors (male: n = 8; female: n = 10), or both muscle groups. The fatigue protocol consisted of ten 30-second sub-maximal isometric contractions. The changes in maximum voluntary contraction (MVC), electrically evoked twitches, and motor unit activation (MUA) were assessed along with the ability to control the sustained contractions (SLP) during the fatigue protocol using a mixed four-factor repeated measures ANOVA (gender × side × muscle × time) design with significance set at p < 0.05.

Results

There was a significant loss of MVC, MUA, and evoked twitch amplitude from pre- to post-fatigue in both the arms and legs. Males had greater relative loss of isometric force, a higher rate of fatigue development, and were less capable of maintaining the fatiguing contractions in the legs when compared to the females.

Conclusion

The nature of the induced fatigue was a combination of central and peripheral fatigue that did not fully recover over a 45-minute period. The results appear to reflect sex differences that are peripheral, and partially support the muscle mass hypothesis for explaining differences in muscular fatigue.
Cellular transfer and AFM imaging of cancer cells using Bioimprint
Authors: Muys JJ , Alkaisi MM , Melville DOS , Nagase J , Sykes P , Parguez GM , Evans JJ
Published: January 2006

A technique for permanently capturing a replica impression of biological cells has been developed to facilitate analysis using nanometer resolution imaging tools, namely the atomic force microscope (AFM). The method, termed Bioimprint™, creates a permanent cell 'footprint' in a non-biohazardous Poly (dimethylsiloxane) (PDMS) polymer composite. The transfer of nanometer scale biological information is presented as an alternative imaging technique at a resolution beyond that of optical microscopy. By transferring cell topology into a rigid medium more suited for AFM imaging, many of the limitations associated with scanning of biological specimens can be overcome. Potential for this technique is demonstrated by analyzing Bioimprint™ replicas created from human endometrial cancer cells. The high resolution transfer of this process is further detailed by imaging membrane morphological structures consistent with exocytosis. The integration of soft lithography to replicate biological materials presents an enhanced method for the study of biological systems at the nanoscale.
Weekly induction intraperitoneal chemotherapy after primary surgical cytoreduction in patients with advanced epithelial ovarian cancer
Authors: Yu Zang Rong , Li Zi Ting , Tang Jie , Huang Xiao , Mo Cai Shu
Published: January 2006

Background

Traditional intraperitoneal (IP) therapy administered simultaneously with intravenous (IV) chemotherapy in the primary setting has been well documented. This retrospective study was conducted to investigate the role of weekly IP therapy as an inducing intervention before front-line IV chemotherapy, particularly in patients with bulky residual disease after surgery.

Methods

A total of 426 patients with advanced ovarian cancer treated between 1990 and 1999, were reviewed. Follow-up data were available in 409 patients. Of whom, 230 patients received postoperative weekly IP therapy with a median cycles of 4, other 179 patients who did not receive any IP therapy were used as the control group.

Results

The median age of the patients was 51 years (range, 20–77 years). One hundred eighty-nine patients with stage III disease and 41 patients with stage IV disease were treated with postoperative IP therapy, respectively. Complications and toxicity were observed in 68 patients (29.5%), but there were no grade 4 toxicities and no patients died of complications or toxicities. In patients with residual disease > 1 cm, the median survival of those with IP delivery of chemotherapy and those without was 21.6 months and 18.8 months, respectively (hazard ratio [HR]= 0.69, P = 0.02). Whereas, in patients with residual disease ≤ 1 cm, the median survival was 46.8 months and 37.6 months, respectively (HR= 0.73, P = 0.09). Multivariate analysis suggested that the factors age ≤ 60 years, stage III, IP therapy and paclitaxel as front-line chemotherapy were associated with a better prognosis for patients with advanced ovarian cancer.

Conclusion

Weekly postoperative IP therapy as an inducing intervention is practical for both physicians and patients with acceptable complications and associated with a lengthened survival of patients with advanced ovarian cancer. Whether this arm can be used in lieu of a traditional one needs further randomized trial to confirm the preliminary results.
Cyclin D1 and Rb protein expression and their correlation with prognosis in patients with colon cancer
Authors: Kouraklis Gregory , Theocharis Stamos , Vamvakas Panayiotis , Vagianos Costas , Glinavou Andromahi , Giaginis Costas , Sioka Crysoula
Published: January 2006

Background

Cyclin D1 plays a major role as a potential contributor to the multistep process of oncogenesis; nevertheless its prognostic significance in colon cancer has already been examined in a few studies and needs to be further delineated. The aim of this study was to assess the expression of cyclin D1 and pRb and to correlate them with tumor histological stage and grade, proliferative capacity (Ki-67 labeling index) and clinical parameters, in order to delineate their impact on prognosis.

Methods

One hundred and eleven patients, who underwent surgical resection of the colon for colon cancer constituted the group of our study. The immunohistochemical expression of cyclin D1, Rb and Ki-67 proteins was examined and correlated with clinico-pathological parameters and survival.

Results

The 5-years survival rate of patients presenting cyclin D1 positive tumors was 54%, while that of cyclin D1 negative ones was 67% (P = > 0.05). The survival rate of patients with pRb positive tumors was similar to that of pRb negatine ones. Significant association was observed between Ki-67 and cyclin D1 positivity (P = 0.045). Univariate analysis revealed worse survival in advanced stage patients presenting cyclin D1 positive tumors (P = 0.025). Additionally, the survival of patients aging less than 70 years old was correlated to cyclin D1 positivity (P = 0.009). Multivariate survival analysis revealed statistical significance for stage and hepatic metastasis.

Conclusion

Even though cyclin D1 and pRb have not disclosed any clear association with shorter survival, cyclin D1 positivity may be a useful predictor of subgroup patients with colon cancer being in advanced stage and early age.
Common angiotensin receptor blockers may directly modulate the immune system via VDR, PPAR and CCR2b
Authors: Marshall Trevor G , Lee Robert E , Marshall Frances E
Published: January 2006

Background

There have been indications that common Angiotensin Receptor Blockers (ARBs) may be exerting anti-inflammatory actions by directly modulating the immune system. We decided to use molecular modelling to rapidly assess which of the potential targets might justify the expense of detailed laboratory validation. We first studied the VDR nuclear receptor, which is activated by the secosteroid hormone 1,25-dihydroxyvitamin-D. This receptor mediates the expression of regulators as ubiquitous as GnRH (Gonadatrophin hormone releasing hormone) and the Parathyroid Hormone (PTH). Additionally we examined Peroxisome Proliferator-Activated Receptor Gamma (PPARgamma), which affects the function of phagocytic cells, and the C-CChemokine Receptor, type 2b, (CCR2b), which recruits monocytes to the site of inflammatory immune challenge.

Results

Telmisartan was predicted to strongly antagonize (Ki≈0.04nmol) the VDR. The ARBs Olmesartan, Irbesartan and Valsartan (Ki≈10 nmol) are likely to be useful VDR antagonists at typical in-vivo concentrations. Candesartan (Ki≈30 nmol) and Losartan (Ki≈70 nmol) may also usefully inhibit the VDR. Telmisartan is a strong modulator of PPARgamma (Ki≈0.3 nmol), while Losartan (Ki≈3 nmol), Irbesartan (Ki≈6 nmol), Olmesartan and Valsartan (Ki≈12 nmol) also seem likely to have significant PPAR modulatory activity. Olmesartan andIrbesartan (Ki≈9 nmol) additionally act as antagonists of a theoretical modelof CCR2b. Initial validation of this CCR2b model was performed, and a proposed model for the AngiotensinII Type1 receptor (AT2R1) has been presented.

Conclusion

Molecular modeling has proven valuable to generate testable hypotheses concerning receptor/ligand binding and is an important tool in drug design. ARBs were designed to act as antagonists for AT2R1, and it was not surprising to discover their affinity for the structurally similar CCR2b. However, this study also found evidence that ARBs modulate the activation of two key nuclear receptors-VDR and PPARgamma. If our simulations are confirmed by experiment, it is possible that ARBs may become useful as potent anti-inflammatory agents, in addition to their current indication as cardiovascular drugs.
Anti-viral RNA silencing: do we look like plants ?
Authors: Saumet Anne , Lecellier Charles-Henri
Published: January 2006

The anti-viral function of RNA silencing was first discovered in plants as a natural manifestation of the artificial 'co-suppression', which refers to the extinction of endogenous gene induced by homologous transgene. Because silencing components are conserved among most, if not all, eukaryotes, the question rapidly arose as to determine whether this process fulfils anti-viral functions in animals, such as insects and mammals. It appears that, whereas the anti-viral process seems to be similarly conserved from plants to insects, even in worms, RNA silencing does influence the replication of mammalian viruses but in a particular mode: micro(mi)RNAs, endogenous small RNAs naturally implicated in translational control, rather than virus-derived small interfering (si)RNAs like in other organisms, are involved. In fact, these recent studies even suggest that RNA silencing may be beneficial for viral replication. Accordingly, several large DNA mammalian viruses have been shown to encode their own miRNAs. Here, we summarize the seminal studies that have implicated RNA silencing in viral infection and compare the different eukaryotic responses.
Intracytoplasmic maturation of the human immunodeficiency virus type 1 reverse transcription complexes determines their capacity to integrate into chromatin
Authors: Iordanskiy Sergey , Berro Reem , Altieri Maria , Kashanchi Fatah , Bukrinsky Michael
Published: January 2006

Background

The early events of the HIV-1 life cycle include entry of the viral core into target cell, assembly of the reverse transcription complex (RTCs) performing reverse transcription, its transformation into integration-competent complexes called pre-integration complexes (PICs), trafficking of complexes into the nucleus, and finally integration of the viral DNA into chromatin. Molecular details and temporal organization of these processes remain among the least investigated and most controversial problems in the biology of HIV.

Results

To quantitatively evaluate maturation and nuclear translocation of the HIV-1 RTCs, nucleoprotein complexes isolated from the nucleus (nRTC) and cytoplasm (cRTC) of HeLa cells infected with MLV Env-pseudotyped HIV-1 were analyzed by real-time PCR. While most complexes completed reverse transcription in the cytoplasm, some got into the nucleus before completing DNA synthesis. The HIV-specific RNA complexes could get into the nucleus when reverse transcription was blocked by reverse transcriptase inhibitor, although nuclear import of RNA complexes was less efficient than of DNA-containing RTCs. Analysis of the RTC nuclear import in synchronized cells infected in the G2/M phase of the cell cycle showed enrichment in the nuclei of RTCs containing incomplete HIV-1 DNA compared to non-synchronized cells, where RTCs with complete reverse transcripts prevailed. Immunoprecipitation assays identified viral proteins IN, Vpr, MA, and cellular Ini1 and PML associated with both cRTCs and nRTCs, whereas CA was detected only in cRTCs and RT was diminished in nRTCs. Cytoplasmic maturation of the complexes was associated with increased immunoreactivity with anti-Vpr and anti-IN antibodies, and decreased reactivity with antibodies to RT. Both cRTCs and nRTCs carried out endogenous reverse transcription reaction in vitro. In contrast to cRTCs, in vitro completion of reverse transcription in nRTCs did not increase their integration into chromatin.

Conclusion

These results suggest that RTC maturation occurs predominantly in the cytoplasm. Immature RTCs containing RT and incomplete DNA can translocate into the nucleus during mitosis and complete reverse transcription, but are defective for integration.
RTE and CTE mRNA export elements synergistically increase expression of unstable, Rev-dependent HIV and SIV mRNAs
Authors: Smulevitch Sergey , Bear Jenifer , Alicea Candido , Rosati Margherita , Jalah Rashmi , Zolotukhin Andrei S , von Gegerfelt Agneta , Michalowski Daniel , Moroni Christoph , Pavlakis George N , Felber Barbara K
Published: January 2006

Studies of retroviral mRNA export identified two distinct RNA export elements utilizing conserved eukaryotic mRNA export mechanism(s), namely the Constitutive Transport Element (CTE) and the RNA Transport Element (RTE). Although RTE and CTE are potent in nucleocytoplasmic mRNA transport and expression, neither element is as powerful as the Rev-RRE posttranscriptional control. Here, we found that whereas CTE and the up-regulatory mutant RTEm26 alone increase expression from a subgenomic gag and env clones, the combination of these elements led to a several hundred-fold, synergistic increase. The use of the RTEm26-CTE combination is a simple way to increase expression of poorly expressed retroviral genes to levels otherwise only achieved via more cumbersome RNA optimization. The potent RTEm26-CTE element could be useful in lentiviral gene therapy vectors, DNA-based vaccine vectors, and gene transfer studies of other poorly expressed genes.
Comparison of real-time PCR and hemagglutination assay for quantitation of human polyomavirus JC
Authors: Chapagain Moti L , Nguyen Taylor , Bui Thomas , Verma Saguna , Nerurkar Vivek R
Published: January 2006

Human polyomavirus JC (JCV), the etiological agent of the disease progressive multifocal leukoencephalopathy (PML) affects immunocompromised patients particularly patients with AIDS. In vitro studies of JCV infection are hampered by the lack of sensitive JCV quantitation tests. Although the hemagglutination (HA) assay has been routinely employed for in vitro quantitation of JCV, its sensitivity is severely limited. We have employed a real-time PCR assay which compares favorably with the HA assay for the in vitro quantitation of JCV. JCV(Mad1), propagated in primary human fetal glial (PHFG) cells in two independent laboratories, was purified and quantitated by the HA assay. Both batches of purified JCV(Mad1) were then serially diluted in Dulbecco's Modified Eagle's Medium to obtain HA titers ranging from 64 to 0.001 HA units (HAU) per 100 μL of virus suspension. DNA was extracted from 100 μL of virus suspension and eluted in 50 μL of buffer, and DNA amplification and quantitation were performed in the Bio-Rad iCycler iQ Multicolor Real-Time PCR Detection System using T-antigen as the target gene. Real-time PCR for quantitation of JCV was sensitive and consistently detected 1.8 × 101 copies of JCV DNA, and as low as 0.001 HAU equivalent of JCV. Moreover, there was a strong linear correlation between the HA assay and the DNA copy number of JCV(Mad1). The intra-run and inter-run coefficients of variation for the JCV standard curve were 0.06% to 4.8% and 2.6% to 5.2%, respectively. Based on these data, real-time PCR can replace the less-sensitive HA assay for the reliable detection, quantitation and monitoring of in vitro JCV replication.
Further evaluation of plasma sphingomyelin levels as a risk factor for coronary artery disease
Authors: Schlitt Axel , Blankenberg Stefan , Yan Daoguang , von Gizycki Hans , Buerke Michael , Werdan Karl , Bickel Christoph , Lackner Karl J , Meyer Juergen , Rupprecht Hans J , Jiang Xian-Cheng
Published: January 2006

Background

Sphingomyelin (SM) is the major phospholipid in cell membranes and in lipoproteins. In human plasma, SM is mainly found in atherogenic lipoproteins; thus, high levels of SM may promote atherogenesis.

Methods

We investigated in a median follow up of 6.0 years the association of SM with the incidence of a combined endpoint (myocardial infarction and cardiovascular death) in stable and unstable patients, and its relation to other marker of atherosclerosis in 1,102 patients with angiographically documented CAD and 444 healthy controls.

Results and discussion

Logistic regression analysis showed that SM categorized by median was associated with an elevated risk for CAD (HR 3.2, 95%CI 2.5–4.0, p < 0.05). SM levels were correlated with apoB (r = 0.34) and triglyceride levels (r = 0.31). In patients with stable angina (n = 614), SM categorized by median was not related to incidence of a combined endpoint (cardiovascular death and myocardial infarction) (p = 0.844 by Log-rank test). However, in patients with acute coronary syndrome (n = 488), elevated SM was related to the combined endpoint (p < 0.05 by Log-rank test), also in a multivariate Cox regression analysis including potential confounders (HR 1.8, 95%CI 1.0–3.3, p < 0.05).

Conclusion

The results of our study reveal that 1) human plasma SM levels are a risk factor for CAD; 2) the pro-atherogenic property of plasma SM might be related to metabolism of apoB-containing or triglyceride-rich lipoproteins; and 3) plasma SM levels are a predictor for outcome of patients with acute coronary syndrome.