bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of two chromogenic media and evaluation of two molecular based identification systems for Enterobacter sakazakii detection
Authors: Lehner Angelika , Nitzsche Sabine , Breeuwer Pieter , Diep Benjamin , Thelen Karin , Stephan Roger
Published: February 2006

Background

Enterobacter sakazakii is a foodborne pathogen that has been associated with sporadic cases and outbreaks causing meningitis, necrotizing enterocolitis and sepsis especially in neonates. The current FDA detection method includes two enrichment steps, the subculturing of the second enrichment broth on a selective agar (VRBG), a further subculturing of selected grown colonies on TSA and the subsequent biochemical identification of yellow-pigmented colonies by API20E. However, there is a strong need for simplified methods for isolation and identification of E. sakazakii. In this study, two chromogenic media, which allow to indicate presumptive E. sakazakii colonies by the alpha glucosidase activity, as well as a newly developed 1,6-alpha-glucosidase based conventional PCR assay and a rRNA oligonucleotide probe based commercial test system for identification of presumptive E. sakazakii were evaluated on 98 target and non-target strains. The methods were compared with respect to specificity aspects.

Results

A total of 75 presumptive E. sakazakii and 23 non-target strains were analysed by using chromogenic media, alpha-glucosidase based PCR assay, and the VIT assay. For most presumptive E. sakazakii strains on the chromogenic media, the PCR and VIT assay confirmed the identification. However, for a number of presumptive E. sakazakii isolates from fruit powder, the alpha-glucosidase PCR and VIT assay did not correspond to the typical E. sakazakii colonies on DFI and ESIA. Further characterization by API32E identification, phylogenetic analysis of partial 16S rRNA sequences and ribotyping strongly suggested, that these strains did not belong to the species E. sakazakii. The newly developed alpha-glucosidase based PCR assay as well as the commercially available VIT Enterobacter sakazakii identification test showed an excellent correlation with the 16S rRNA data, and are thus well suited for identification of E. sakazakii.

Conclusion

The results indicate that presumptive colonies on ESIA and DFI media need further species identification. Both evaluated molecular methods, the alpha-glucosidase PCR and the 16S RNA in situ hybridisation test (VIT), although based on completely different target regions and methodologies performed equally well in terms of specificity.
Length-dependent degradation of single-stranded 3' ends by the Werner syndrome protein (WRN): implications for spatial orientation and coordinated 3' to 5' movement of its ATPase/helicase and exonuclease domains
Authors: Machwe Amrita , Xiao Liren , Orren David K
Published: February 2006

Background

The cancer-prone and accelerated aging disease Werner syndrome is caused by loss of function of the WRN gene product that possesses ATPase, 3' to 5' helicase and 3' to 5' exonuclease activities. Although WRN has been most prominently suggested to function in telomere maintenance, resolution of replication blockage and/or recombinational repair, its exact role in DNA metabolism remains unclear. WRN is the only human RecQ family member to possess both helicase and exonuclease activity, but the mechanistic relationship between these activities is unknown. In this study, model single-stranded and 3' overhang DNA substrates of varying length and structure were used to examine potential coordination between the ATPase/helicase and exonuclease activities of WRN.

Results

Our results show that WRN can not only bind to but also catalyze the 3' to 5' degradation of single-stranded and 3' overhang DNA substrates, structures that were previously thought to be refractory to WRN exonuclease activity. The length of the single-stranded regions in these structures is a critical parameter in determining both the binding affinity and the level of exonuclease activity of WRN. Most importantly, specific nucleotide cofactors dramatically stimulate WRN exonuclease activity on these substrates, with conditions that permit ATP hydrolysis not only resulting in enhanced exonuclease activity but also altering its length dependence on these structures. Parallel experiments show that a deletion mutant containing only the WRN exonuclease domain lacks both this DNA length and nucleotide cofactor dependence, demonstrating that the interaction of the ATPase/helicase domain of WRN with the DNA substrate has a profound influence on exonuclease activity.

Conclusion

Our results indicate that, under conditions that permit ATP hydrolysis, there is a dynamic and cooperative relationship between the distinct ATPase/helicase and exonuclease domains of WRN with regard to their orientation on DNA. Based on these results, models are proposed for the coordinated, unidirectional 3' to 5' movement of the helicase and exonuclease domains of WRN on DNA that should be informative for elucidating its function in genome maintenance.
Dendritic mRNAs encode diversified functionalities in hippocampal pyramidal neurons
Authors: Zhong Jun , Zhang Theresa , Bloch Lisa M
Published: February 2006

Background

Targeted transport of messenger RNA and local protein synthesis near the synapse are important for synaptic plasticity. In order to gain an overview of the composition of the dendritic mRNA pool, we dissected out stratum radiatum (dendritic lamina) from rat hippocampal CA1 region and compared its mRNA content with that of stratum pyramidale (cell body layer) using a set of cDNA microarrays. RNAs that have over-representation in the dendritic fraction were annotated and sorted into function groups.

Results

We have identified 154 dendritic mRNA candidates, which can be arranged into the categories of receptors and channels, signaling molecules, cytoskeleton and adhesion molecules, and factors that are involved in membrane trafficking, in protein synthesis, in posttranslational protein modification, and in protein degradation. Previously known dendritic mRNAs such as MAP2, calmodulin, and G protein gamma subunit were identified from our screening, as were mRNAs that encode proteins known to be important for synaptic plasticity and memory, such as spinophilin, Pumilio, eEF1A, and MHC class I molecules. Furthermore, mRNAs coding for ribosomal proteins were also found in dendrites.

Conclusion

Our results suggest that neurons transport a variety of mRNAs to dendrites, not only those directly involved in modulating synaptic plasticity, but also others that play more common roles in cellular metabolism.
Phylogenetic diversification of glycogen synthase kinase 3/SHAGGY-like kinase genes in plants
Authors: Yoo Mi-Jeong , Albert Victor A , Soltis Pamela S , Soltis Douglas E
Published: February 2006

Background

The glycogen synthase kinase 3 (GSK3)/SHAGGY-like kinases (GSKs) are non-receptor serine/threonine protein kinases that are involved in a variety of biological processes. In contrast to the two members of theGSK3family in mammals, plants appear to have a much larger set of divergentGSKgenes. Plant GSKs are encoded by a multigene family; analysis of theArabidopsisgenome revealed the existence of 10GSKgenes that fall into four major groups. Here we characterized the structure ofArabidopsisand riceGSKgenes and conducted the first broad phylogenetic analysis of the plantGSKgene family, covering a taxonomically diverse array of algal and land plant sequences.

Results

We found that the structure ofGSKgenes is generally conserved inArabidopsisand rice, although we documented examples of exon expansion and intron loss. Our phylogenetic analyses of 139 sequences revealed four major clades ofGSKgenes that correspond to the four subgroups initially recognized inArabidopsis. ESTs from basal angiosperms were represented in all four major clades;GSKhomologs from the basal angiospermPersea americana(avocado) appeared in all four clades. Gymnosperm sequences occurred in clades I, III, and IV, and a sequence of the red algaPorphyrawas sister to all green plant sequences.

Conclusion

Our results indicate that (1) the plant-specificGSKgene lineage was established early in the history of green plants, (2) plantGSKsbegan to diversify prior to the origin of extant seed plants, (3) three of the four major clades ofGSKspresent inArabidopsisand rice were established early in the evolutionary history of extant seed plants, and (4) diversification into four major clades (as initially reported inArabidopsis) occurred either just prior to the origin of the angiosperms or very early in angiosperm history.
Generation and analysis of expressed sequence tags from NaCl-treated Glycine soja
Authors: Ji Wei , Li Yong , Li Jie , Dai Cui-hong , Wang Xi , Bai Xi , Cai Hua , Yang Liang , Zhu Yan-ming
Published: February 2006

Background

Salinization causes negative effects on plant productivity and poses an increasingly serious threat to the sustainability of agriculture. Wild soybean (Glycine soja) can survive in highly saline conditions, therefore provides an ideal candidate plant system for salt tolerance gene mining.

Results

As a first step towards the characterization of genes that contribute to combating salinity stress, we constructed a full-length cDNA library of Glycine soja (50109) leaf treated with 150 mM NaCl, using the SMART technology. Random expressed sequence tag (EST) sequencing of 2,219 clones produced 2,003 cleaned ESTs for gene expression analysis. The average read length of cleaned ESTs was 454 bp, with an average GC content of 40%. These ESTs were assembled using the PHRAP program to generate 375 contigs and 696 singlets. The resulting unigenes were categorized according to the Gene Ontology (GO) hierarchy. The potential roles of gene products associated with stress related ESTs were discussed. We compared the EST sequences of Glycine soja to that of Glycine max by using the blastn algorithm. Most expressed sequences from wild soybean exhibited similarity with soybean. All our EST data are available on the Internet (GenBank_Accn: DT082443~DT084445).

Conclusion

The Glycine soja ESTs will be used to mine salt tolerance gene, whose full-length cDNAs will be obtained easily from the full-length cDNA library. Comparison of Glycine soja ESTs with those of Glycine max revealed the potential to investigate the wild soybean's expression profile using the soybean's gene chip. This will provide opportunities to understand the genetic mechanisms underlying stress response of plants.
Maximising response to postal questionnaires – A systematic review of randomised trials in health research
Authors: Nakash Rachel A , Hutton Jane L , Jørstad-Stein Ellen C , Gates Simon , Lamb Sarah E
Published: February 2006

Background

Postal self-completion questionnaires offer one of the least expensive modes of collecting patient based outcomes in health care research. The purpose of this review is to assess the efficacy of methods of increasing response to postal questionnaires in health care studies on patient populations.

Methods

The following databases were searched: Medline, Embase, CENTRAL, CDSR, PsycINFO, NRR and ZETOC. Reference lists of relevant reviews and relevant journals were hand searched. Inclusion criteria were randomised trials of strategies to improve questionnaire response in health care research on patient populations. Response rate was defined as the percentage of questionnaires returned after all follow-up efforts. Study quality was assessed by two independent reviewers. The Mantel-Haenszel method was used to calculate the pooled odds ratios.

Results

Thirteen studies reporting fifteen trials were included. Implementation of reminder letters and telephone contact had the most significant effect on response rates (odds ratio 3.7, 95% confidence interval 2.30 to 5.97 p = <0.00001). Shorter questionnaires also improved response rates to a lesser degree (odds ratio 1.4, 95% confidence interval 1.19 to 1.54). No evidence was found that incentives, re-ordering of questions or including an information brochure with the questionnaire confer any additional advantage.

Conclusion

Implementing repeat mailing strategies and/or telephone reminders may improve response to postal questionnaires in health care research. Making the questionnaire shorter may also improve response rates. There is a lack of evidence to suggest that incentives are useful. In the context of health care research all strategies to improve response to postal questionnaires require further evaluation.
Increased cholinergic contractions of jejunal smooth muscle caused by a high cholesterol diet are prevented by the 5-HT4agonist – tegaserod
Authors: Mathison Ronald , Shaffer Eldon
Published: February 2006

Background

Excess cholesterol in bile and in blood is a major risk factor for the respective development of gallbladder disease and atherosclerosis. This lipid in excess negatively impacts the functioning of other smooth muscles, including the intestine. Serotonin is an important mediator of the contractile responses of the small intestine. Drugs targeting the serotonin receptor are used as prokinetic agents to manage intestinal motor disorders, in particular irritable bowel syndrome. Thus, tegaserod, acting on 5-HT4receptor, ideally should obviate detrimental effects of excessive cholesterol on gastrointestinal smooth muscle. In this study we examined the effect of tegaserod on cholesterol-induced changes in the contractile responses of intestinal smooth muscle.

Methods

The effects of a high cholesterol (1%) diet on thein vitrocontractile responses of jejunal longitudinal smooth muscle from Richardson ground squirrels to the cholinergic agonist carbachol were examined in the presence or absence of tetrodrodotoxin (TTX). Two groups of animals, fed either low (0.03%) or high cholesterol rat chow diet, were further divided into two subgroups and treated for 28 days with either vehicle or tegaserod.

Results

The high cholesterol diet increased, by nearly 2-fold, contractions of the jejunal longitudinal smooth muscle elicited by carbachol. These cholinergic contractions were mediated by muscarinic receptors since they were blocked by scopolamine, a muscarinic receptor antagonist, but not by the nicotinic receptor antagonist, hexamethonium. Tegaserod treatment, which did not affect cholinergic contractions of tissues from low cholesterol fed animals, abrogated the increase caused by the high cholesterol diet. With low cholesterol diet TTX enhanced carbachol-evoked contractions, whereas this action potential blocker did not affect the augmented cholinergic contractions seen with tissues from animals on the high cholesterol diet. Tegaserod-treatment removed the effects of a high cholesterol diet on neuronal muscarinic receptors, as the potentiating effect of TTX on carbachol-elicited contractions was maintained in these animals.

Conclusion

A high cholesterol diet causes significant changes to cholinergic neurotransmission in the enteric nerves of the jejunum. The mechanisms by which these effects of cholesterol are reversed by tegaserod are unknown, but relate to removal of an inhibitory effect of cholesterol on enteric nerves.
Reduced responsiveness is an essential feature of chronic fatigue syndrome: A fMRI study
Authors: Tanaka Masaaki , Sadato Norihiro , Okada Tomohisa , Mizuno Kei , Sasabe Tetsuya , Tanabe Hiroki C , Saito Daisuke N , Onoe Hirotaka , Kuratsune Hirohiko , Watanabe Yasuyoshi
Published: February 2006

Background

Although the neural mechanism of chronic fatigue syndrome has been investigated by a number of researchers, it remains poorly understood.

Methods

Using functional magnetic resonance imaging, we studied brain responsiveness in 6 male chronic fatigue syndrome patients and in 7 age-matched male healthy volunteers. Responsiveness of auditory cortices to transient, short-lived, noise reduction was measured while subjects performed a fatigue-inducing continual visual search task.

Results

Responsiveness of the task-dependent brain regions was decreased after the fatigue-inducing task in the normal and chronic fatigue syndrome subjects and the decrement of the responsiveness was equivalent between the 2 groups. In contrast, during the fatigue-inducing period, although responsiveness of auditory cortices remained constant in the normal subjects, it was attenuated in the chronic fatigue syndrome patients. In addition, the rate of this attenuation was positively correlated with the subjective sensation of fatigue as measured using a fatigue visual analogue scale, immediately before the magnetic resonance imaging session.

Conclusion

Chronic fatigue syndrome may be characterised by attenuation of the responsiveness to stimuli not directly related to the fatigue-inducing task.
The use of complementary and alternative medicines among patients with locally advanced breast cancer – a descriptive study
Authors: Helyer Lucy K , Chin Stephen , Chui Betty K , Fitzgerald Barbara , Verma Sunil , Rakovitch Eileen , Dranitsaris George , Clemons Mark
Published: February 2006

Background

Complementary and alternative medicine (CAM) use is common among cancer patients. This paper reviews the use of CAM in a series of patients with locally advanced breast cancer (LABC).

Methods

Women with LABC attending a specialist clinic at a single Canadian cancer centre were identified and approached. Participants completed a self-administered survey regarding CAM usage, beliefs associated with CAM usage, views of their risks of developing recurrent cancer and of dying of breast cancer. Responses were scored and compared between CAM users and non-users.

Results

Thirty-six patients were approached, 32 completed the questionnaire (response rate 89%). Forty-seven percent of LABC patients were identified as CAM users. CAM users were more likely to be younger, married, in a higher socioeconomic class and of Asian ethnicity than non-users. CAM users were likely to use multiple modalities simultaneously (median 4) with vitamins being the most popular (60%). Motivation for CAM therapy was described as, "assisting their body to heal" (75%), to 'boost the immune system' (56%) and to "give a feeling of control with respect to their treatment" (56%). CAM therapy was used concurrently with conventional treatment in 88% of cases, however, 12% of patients felt that CAM could replace their conventional therapy. Psychological evaluation suggests CAM users perceived their risk of dying of breast cancer was similar to that of the non-Cam group (33% vs. 35%), however the CAM group had less severe anxiety and depression.

Conclusion

The motivation, objectives and benefits of CAM therapy in a selected population of women with LABC are similar to those reported for women diagnosed with early stage breast cancer. CAM users display less anxiety and depression and are less likely to believe they will die of their breast cancer. However the actual benefit to overall and disease free survival has yet to be demonstrated, as well as the possible interactions with conventional therapy. Consequently more research is needed in this ever-growing field.
A transcriptome anatomy of human colorectal cancers
Authors: Lü Bingjian , Xu Jing , Lai Maode , Zhang Hao , Chen Jian
Published: February 2006

Background

Accumulating databases in human genome research have enabled integrated genome-wide study on complicated diseases such as cancers. A practical approach is to mine a global transcriptome profile of disease from public database. New concepts of these diseases might emerge by landscaping this profile.

Methods

In this study, we clustered human colorectal normal mucosa (N), inflammatory bowel disease (IBD), adenoma (A) and cancer (T) related expression sequence tags (EST) into UniGenes via an in-house GetUni software package and analyzed the transcriptome overview of these libraries by GOTree Machine (GOTM). Additionally, we downloaded UniGene based cDNA libraries of colon and analyzed them by Xprofiler to cross validate the efficiency of GetUni. Semi-quantitative RT-PCR was used to validate the expression of β-catenin and. 7 novel genes in colorectal cancers.

Results

The efficiency of GetUni was successfully validated by Xprofiler and RT-PCR. Genes in library N, IBD and A were all found in library T. A total of 14,879 genes were identified with 2,355 of them having at least 2 transcripts. Differences in gene enrichment among these libraries were statistically significant in 50 signal transduction pathways and Pfam protein domains by GOTM analysis P < 0.01 Hypergeometric Test). Genes in two metabolic pathways, ribosome and glycolysis, were more enriched in the expression profiles of A and IBD than in N and T. Seven transmembrane receptor superfamily genes were typically abundant in cancers.

Conclusion

Colorectal cancers are genetically heterogeneous. Transcription variants are common in them. Aberrations of ribosome and glycolysis pathway might be early indicators of precursor lesions in colon cancers. The electronic gene expression profile could be used to highlight the integral molecular events in colorectal cancers.
Sexual behaviour among casual workers in an international nightlife resort: a case control study
Authors: Hughes Karen , Bellis Mark A
Published: February 2006

Background

Young holidaymakers report increased sexual risk-taking abroad, yet little is currently known about the sexual behaviour of those who extend time abroad through casual work.

Methods

Information on sexual behaviour was collected via an anonymous questionnaire administered to British bar and nightclub workers in Ibiza (cases, n = 92) and British people visiting Ibiza for holiday purposes only (controls, n = 868).

Results

Four in five (80.5%) cases who arrived in Ibiza without a partner had sex during their stay and of these two thirds (65.5%) had unprotected sex. Cases were more likely to report sexual risk-taking in Ibiza than controls and reported greater numbers of sexual partners prior to their visit. However, they had fewer sexual partners per week of stay.

Conclusion

Casual workers in bars and nightclubs abroad are a key risk group for sexual health and a potential conduit for the international spread of sexually transmitted infections. While they are an important target group for sexual health promotion, appropriately trained they are also ideally placed to deliver sexual health interventions to other young travellers.
Predicting smear negative pulmonary tuberculosis with classification trees and logistic regression: a cross-sectional study
Authors: Mello Fernanda Carvalho de Queiroz , Bastos Luiz Gustavo do Valle , Soares Sérgio Luiz Machado , Rezende Valéria MC , Conde Marcus Barreto , Chaisson Richard E , Kritski Afrânio Lineu , Ruffino-Netto Antonio , Werneck Guilherme Loureiro
Published: February 2006

Background

Smear negative pulmonary tuberculosis (SNPT) accounts for 30% of pulmonary tuberculosis cases reported yearly in Brazil. This study aimed to develop a prediction model for SNPT for outpatients in areas with scarce resources.

Methods

The study enrolled 551 patients with clinical-radiological suspicion of SNPT, in Rio de Janeiro, Brazil. The original data was divided into two equivalent samples for generation and validation of the prediction models. Symptoms, physical signs and chest X-rays were used for constructing logistic regression and classification and regression tree models. From the logistic regression, we generated a clinical and radiological prediction score. The area under the receiver operator characteristic curve, sensitivity, and specificity were used to evaluate the model's performance in both generation and validation samples.

Results

It was possible to generate predictive models for SNPT with sensitivity ranging from 64% to 71% and specificity ranging from 58% to 76%.

Conclusion

The results suggest that those models might be useful as screening tools for estimating the risk of SNPT, optimizing the utilization of more expensive tests, and avoiding costs of unnecessary anti-tuberculosis treatment. Those models might be cost-effective tools in a health care network with hierarchical distribution of scarce resources.
Estimation of optimal birth weights and gestational ages for twin births in Japan
Authors: Kato Noriko , Matsuda Tomohiro
Published: February 2006

Background

As multiple pregnancies show a higher incidence of complications than singletons and carry a higher perinatal risk, the calculation of birth weight – and gestational age (GA)-specific perinatal mortality rates (PMR) for multiple births is necessary in order to estimate the lowest PMR for these groups.

Methods

Details of all reported twins (192,987 live births, 5,539 stillbirths and 1,830 early neonatal deaths) in Japan between 1990 and 1999 were analyzed and compared with singletons (10,021,275 live births, 63,972 fetal deaths and 16,862 early neonatal deaths) in the annual report of vital statistics of Japan. The fetal death rate (FDR) and PMR were calculated for each category of birth weight at 500-gram intervals and GA at four-week intervals. The FDR according to birth weight and GA category was calculated as fetal deaths/(fetal deaths + live births) × 1000. The perinatal mortality rate (PMR) according to birth weight and GA category, was calculated as (fetal deaths + early neonatal deaths)/(fetal deaths + live births) × 1000. Within each category, the lowest FDR and PMR were assigned with a relative risk (RR) of 1.0 as a reference and all other rates within each category were compared to this lowest rate.

Results

The overall PMR per 1,000 births for singletons was 6.9, and the lowest PMR was 1.1 for birth weight (3.5–4.0 kg) and GA (40- weeks). For twins, the overall PMR per 1,000 births was 36.8, and the lowest PMR was 3.9 for birth weight (2.5–3.0 kg) and GA (36–39 weeks). At optimal birth weight and GA, the PMR was reduced to 15.9 percent for singletons, and 10.6 percent for twins, compared to the overall PMR. The risk of perinatal mortality was greater in twins than in singletons at the same deviation from the ideal category of each plurality.

Conclusion

PMRs are potentially reduced by attaining the ideal birth weight and GA. More than 90 percent of mortality could be reduced by attaining the optimal GA and birth weight in twins by taking particular care to ensure appropriate pregnancy weight gain, as well as adequate control for obstetric complications.
Little effects of Insulin-like Growth Factor-I on testicular atrophy induced by hypoxia
Authors: Diez-Caballero Fernando , Castilla-Cortázar Inma , Garcia-Fernandez Maria , Puche Juan Enrique , Diaz-Sanchez Matias , Casares Amelia Diaz , Aliaga-Montilla M Aurelia , Rodriguez-Borrajo Coronación , Gonzalez-Barón Salvador
Published: February 2006

Background

Insulin-like Growth Factor-I (IGF-I) supplementation restores testicular atrophy associated with advanced liver cirrhosis that is a condition of IGF-I deficiency. The aim of this work was to evaluate the effect of IGF-I in rats with ischemia-induced testicular atrophy (AT) without liver disease and consequently with normal serum level of IGF-I.

Methods

Testicular atrophy was induced by epinephrine (1, 2 mg/Kg intra-scrotal injection five times per week) during 11 weeks. Then, rats with testicular atrophy (AT) were divided into two groups (n = 10 each): untreated rats (AT) receiving saline sc, and AT+IGF, which were treated with IGF-I (2 μg.100 g b.w.-1.day-1, sc.) for 28d. Healthy controls (CO, n = 10) were studied in parallel. Animals were sacrificed on day 29th. Hypophyso-gonadal axis, IGF-I and IGFBPs levels, testicular morphometry and histopathology, immuno-histochemical studies and antioxidant enzyme activity phospholipid hydroperoxide glutathione peroxidase (PHGPx) were assessed.

Results

Compared to controls, AT rats displayed a reduction in testicular size and weight, with histological testicular atrophy, decreased cellular proliferation and transferrin expression, and all of these alterations were slightly improved by IGF-I at low doses. IGF-I therapy increased signifincantly steroidogenesis and PHGPx activity (p < 0.05). Interestingly, plasma IGF-I did not augment in rats with testicular atrophy treated with IGF-I, while IGFBP3 levels, that reduces IGF-I availability, was increased in this group (p < 0.05).

Conclusion

In testicular atrophy by hypoxia, condition without IGF-I deficiency, IGF-treatment induces only partial effects. These findings suggest that IGF-I therapy appears as an appropriate treatment in hypogonadism only when this is associated to conditions of IGF-I deficiency (such as Laron Syndrom or liver cirrhosis).
Surgical margins and survival after head and neck cancer surgery
Authors: Haque Reina , Contreras Richard , McNicoll Michael P , Eckberg Evelyn C , Petitti Diana B
Published: February 2006

Background

Mixed results exist as to whether positive surgical margins impact survival. The aim of this study was to determine whether positive surgical margins are indeed associated with decreased survival in patients with primary head and neck cancer.

Methods

We conducted a retrospective cohort study of 261 cases diagnosed with cancer of the larynx or tongue between 1995 and 1999. Cases were followed through December 31, 2002. Survival curves by margin status were generated by Kaplan-Meier methods. Categorical data were evaluated with odds ratios (OR).

Results

All-cause mortality was markedly higher in cases with positive margins as compared with those with negative margins (54% versus 29%, P = 0.005). This pattern also appeared after adjusting for age and sex (OR = 2.97, 95% CI: 1.29 – 6.84).

Conclusion

Our findings suggest that positive surgical margin status is associated with increased mortality. This association also generally persists after adjustment for tumor size, stage, and adjuvant therapy.
Effect of needle puncture and electro-acupuncture on mucociliary clearance in anesthetized quails
Authors: Tai Shusheng , Wang Jiulin , Sun Feng , Xutian Stevenson , Wang Tianshan , King Malcolm
Published: February 2006

Background

Acupuncture therapy for obstructive respiratory diseases has been effectively used in clinical practice and the acupuncture points or acupoints of Zhongfu and Tiantu are commonly-used acupoints to treat patients with the diseases. Since the impaired mucociliary clearance is among the most important features of airway inflammation in most obstructive respiratory diseases, the effect of needle puncture and electro-acupuncture at the specific acupoints on tracheal mucociliary clearance was investigated in anesthetized quails.

Methods

Mucociliary transport velocity on tracheal mucosa was measured through observing the optimal pathway, and fucose and protein contents in tracheal lavages were determined with biochemical methods. In the therapeutic group, needle puncture or electro-acupuncture stimulation to the acupoints was applied without or with constant current output in 2 mA and at frequency of 100 Hz for 60 minutes. In the sham group, electro-acupuncture stimulation to Liangmen was applied.

Results

Our present experiments demonstrated that the electro-acupuncture stimulation to Zhongfu and Tiantu significantly increased tracheal mucociliary transport velocity and decreased the content of protein in the tracheal lavage, compared with the control group. Moreover, either needle puncture or electro-acupuncture stimulation to Zhongfu and Tiantu significantly reverted the human neutrophil elastase-induced decrease in tracheal mucociliary transport velocity and human neutrophil elastase -induced increase in the contents of fucose and protein in the tracheal lavage, compared with the control group.

Conclusion

These results suggest that either needle puncture or electro-acupuncture stimulation to the effective acupoints significantly improves both airway mucociliary clearance and the airway surface liquid and that the improvements maybe ascribed to both the special function of the points and the substantial stimulation of electricity.
Development, implementation and pilot evaluation of a Web-based Virtual Patient Case Simulation environment – Web-SP
Authors: Zary Nabil , Johnson Gunilla , Boberg Jonas , Fors Uno GH
Published: February 2006

Background

The Web-based Simulation of Patients (Web-SP) project was initiated in order to facilitate the use of realistic and interactive virtual patients (VP) in medicine and healthcare education. Web-SP focuses on moving beyond the technology savvy teachers, when integrating simulation-based education into health sciences curricula, by making the creation and use of virtual patients easier. The project strives to provide a common generic platform for design/creation, management, evaluation and sharing of web-based virtual patients. The aim of this study was to evaluate if it was possible to develop a web-based virtual patient case simulation environment where the entire case authoring process might be handled by teachers and which would be flexible enough to be used in different healthcare disciplines.

Results

The Web-SP system was constructed to support easy authoring, management and presentation of virtual patient cases. The case authoring environment was found to facilitate for teachers to create full-fledged patient cases without the assistance of computer specialists. Web-SP was successfully implemented at several universities by taking into account key factors such as cost, access, security, scalability and flexibility. Pilot evaluations in medical, dentistry and pharmacy courses shows that students regarded Web-SP as easy to use, engaging and to be of educational value. Cases adapted for all three disciplines were judged to be of significant educational value by the course leaders.

Conclusion

The Web-SP system seems to fulfil the aim of providing a common generic platform for creation, management and evaluation of web-based virtual patient cases. The responses regarding the authoring environment indicated that the system might be user-friendly enough to appeal to a majority of the academic staff. In terms of implementation strengths, Web-SP seems to fulfil most needs from course directors and teachers from various educational institutions and disciplines. The system is currently in use or under implementation in several healthcare disciplines at more than ten universities worldwide. Future aims include structuring the exchange of cases between teachers and academic institutions by building a VP library function. We intend to follow up the positive results presented in this paper with other studies looking at the learning outcomes, critical thinking and patient management. Studying the potential of Web-SP as an assessment tool will also be performed.

More information about Web-SP: http://websp.lime.ki.se
Questionnaire survey of working relationships between nurses and doctors in University Teaching Hospitals in Southern Nigeria
Authors: Ogbimi Roseline I , Adebamowo Clement A
Published: February 2006

Background

Smooth working relationships between nurses and doctors are necessary for efficient health care delivery. However, previous studies have shown that this is often absent with negative impact on the quality of health care delivery. In 2002, we studied factors that affect nurse-doctor working relationships in University Teaching Hospitals (UTH) in Southern Nigeria in order to characterize it and identify managerial and training needs that might be used to improve it.

Method

Questionnaire survey of doctors and nurses working in four UTH in Southern Nigeria was done in 2002. The setting and subjects were selected by random sampling procedures. Information on factors in domains of work, union activities, personnel and hospital management were studied using closed and open-ended questionnaires.

Results

Nurse-doctor working relationships were statistically significantly affected by poor after-work social interaction, staff shortages, activist unionism, disregard for one's profession, and hospital management and government policies. In general, nurses had better opinion of doctors' work than doctors had about nurses' work.

Conclusion

Working relationships between doctors and nurses need to be improved through improved training and better working conditions, creation of better working environment, use of alternative methods of conflict resolution and balanced hospital management and government policies. This will improve the retention of staff, job satisfaction and efficiency of health care delivery in Nigeria.
Location of residence associated with the likelihood of patient visit to the preoperative assessment clinic
Authors: Seidel Judy E , Beck Cynthia A , Pocobelli Gaia , Lemaire Jane B , Bugar Jennifer M , Quan Hude , Ghali William A
Published: February 2006

Background

Outpatient preoperative assessment clinics were developed to provide an efficient assessment of surgical patients prior to surgery, and have demonstrated benefits to patients and the health care system. However, the centralization of preoperative assessment clinics may introduce geographical barriers to utilization that are dependent on where a patient lives with respect to the location of the preoperative assessment clinic.

Methods

The association between geographical distance from a patient's place of residence to the preoperative assessment clinic, and the likelihood of a patient visit to the clinic prior to surgery, was assessed for all patients undergoing surgery at a tertiary health care centre in a major Canadian city. The odds of attending the preoperative clinic were adjusted for patient characteristics and clinical factors.

Results

Patients were less likely to visit the preoperative assessment clinic prior to surgery as distance from the patient's place of residence to the clinic increased (adjusted OR = 0.52, 95% CI 0.44–0.63 for distances between 50–100 km, and OR = 0.26, 95% CI 0.21–0.31 for distances greater than 250 km). This 'distance decay' effect was remarkable for all surgical specialties.

Conclusion

The present study demonstrates that the likelihood of a patient visiting the preoperative assessment clinic appears to depend on the geographical location of patients' residences. Patients who live closest to the clinic tend to be seen more often than patients who live in rural and remote areas. This observation may have implications for achieving the goals of equitable access, and optimal patient care and resource utilization in a single universal insurer health care system.
Compression or tension? The stress distribution in the proximal femur
Authors: Rudman KE , Aspden RM , Meakin JR
Published: February 2006

Background

Questions regarding the distribution of stress in the proximal human femur have never been adequately resolved. Traditionally, by considering the femur in isolation, it has been believed that the effect of body weight on the projecting neck and head places the superior aspect of the neck in tension. A minority view has proposed that this region is in compression because of muscular forces pulling the femur into the pelvis. Little has been done to study stress distributions in the proximal femur. We hypothesise that under physiological loading the majority of the proximal femur is in compression and that the internal trabecular structure functions as an arch, transferring compressive stresses to the femoral shaft.

Methods

To demonstrate the principle, we have developed a 2D finite element model of the femur in which body weight, a representation of the pelvis, and ligamentous forces were included. The regions of higher trabecular bone density in the proximal femur (the principal trabecular systems) were assigned a higher modulus than the surrounding trabecular bone. Two-legged and one-legged stances, the latter including an abductor force, were investigated.

Results

The inclusion of ligamentous forces in two-legged stance generated compressive stresses in the proximal femur. The increased modulus in areas of greater structural density focuses the stresses through the arch-like internal structure. Including an abductor muscle force in simulated one-legged stance also produced compression, but with a different distribution.

Conclusion

This 2D model shows, in principle, that including ligamentous and muscular forces has the effect of generating compressive stresses across most of the proximal femur. The arch-like trabecular structure transmits the compressive loads to the shaft. The greater strength of bone in compression than in tension is then used to advantage. These results support the hypothesis presented. If correct, a better understanding of the stress distribution in the proximal femur may lead to improvements in prosthetic devices and an appreciation of the effects of various surgical procedures affecting load transmission across the hip.
Algorithm for multi-curve-fitting with shared parameters and a possible application in evoked compound action potential measurements
Authors: Spitzer Philipp , Zierhofer Clemens , Hochmair Erwin
Published: February 2006

Background

Experimental results are commonly fitted by determining parameter values of suitable mathematical expressions. In case a relation exists between different data sets, the accuracy of the parameters obtained can be increased by incorporating this relationship in the fitting process instead of fitting the recordings separately.

Methods

An algorithm to fit multiple measured curves simultaneously was developed. The method accounts for parameters that are shared by some curves. It can be applied to either linear or nonlinear equations. Simulated noisy "measurement results" were created to compare the introduced method to the "straight forward" way of fitting the curves separately.

Results

The analysis of the simulated measurements confirm, that the introduced method yields more accurate parameters compared to the ones gained by fitting the measurements separately. Therefore it needs more computer time. As an example, the new fitting algorithm is applied to the measurements of the evoked compound action potentials (ECAP) of the auditory nerve: This leads to promising ideas to reduce artefacts generated by the measuring process.

Conclusion

The introduced fitting algorithm uses the relationship between multiple measurement results to increase the accuracy of the parameters. Its application in the field of ECAP measurements is promising and should be further investigated.
The association between low level exposures to ambient air pollution and term low birth weight: a retrospective cohort study
Authors: Dugandzic Rose , Dodds Linda , Stieb David , Smith-Doiron Marc
Published: February 2006

Background

Studies in areas with relatively high levels of air pollution have found some positive associations between exposures to ambient levels of air pollution and several birth outcomes including low birth weight (LBW). The purpose of this study was to examine the association between LBW among term infants and ambient air pollution, by trimester of exposure, in a region of lower level exposures.

Methods

The relationship between LBW and ambient levels of particulate matter up to 10 um in diameter (PM10), sulfur dioxide (SO2) and ground-level ozone (O3) was evaluated using the Nova Scotia Atlee Perinatal Database and ambient air monitoring data from the Environment Canada National Air Pollution Surveillance Network and the Nova Scotia Department of Environment. The cohort consisted of live singleton births (≥37 weeks of gestation) between January1,1988 and December31,2000. Maternal exposures to air pollution were assigned to women living within 25 km of a monitoring station at the time of birth. Air pollution was evaluated as a continuous and categorical variable (using quartile exposures) for each trimester and relative risks were estimated from logistic regression, adjusted for confounding variables.

Results

There were 74,284 women with a term, singleton birth during the study period and with exposure data. In the analyses unadjusted for year of birth, first trimester exposures in the highest quartile for SO2 and PM10suggested an increased risk of delivering a LBW infant (relative risk = 1.36, 95% confidence interval = 1.04 to 1.78 for SO2 exposure and relative risk = 1.33, 95% confidence interval = 1.02 to 1.74 for PM10). After adjustment for birth year, the relative risks were attenuated somewhat and not statistically significant. A dose-response relationship for SO2 was noted with increasing levels of exposure. No statistically significant effects were noted for ozone.

Conclusion

Our results suggest that exposure during the first trimester to relatively low levels of some air pollutants may be associated with a reduction in birth weight in term-born infants. These findings have implications for the development of effective risk management strategies to minimize the public health impacts for pregnant women.
Impact of IL8 and IL8-Receptor alpha polymorphisms on the genetics of bronchial asthma and severe RSV infections
Authors: Puthothu Beena , Krueger Marcus , Heinze Jessica , Forster Johannes , Heinzmann Andrea
Published: February 2006

Background

Interleukin 8 (IL8) belongs to the family of chemokines. It mediates the activation and migration of neutrophils from peripheral blood into tissue and hereby plays a pivotal role in the initiation of inflammation. Thus it is important in inflammatory lung diseases like bronchial asthma or severe infections by Respiratory Syncytial Virus (RSV). IL8 acts through binding to the IL8-Receptor alpha (IL8RA). For both genes association with asthma has been described. In addition, IL8 has been found in association with RSV bronchiolitis. The aim of our study was to test both genes for association with asthma and severe RSV infections. In addition we were interested in whether a common genetic background of both diseases exists in regards to these genes.

Methods

We genotyped the two IL8 promotor polymorphisms -251A/T and -781C/T and the three amino acid variants M31R, S276T and R335C in IL8RA on 322 children with asthma, 131 infants with severe RSV associated diseases and 270 controls. Statistical analyses made use of the Armitage's trend test for single polymorphisms and FAMHAP for calculations of haplotypes.

Results

We found association of the IL8 polymorphism -781C/T as well as IL8 haplotypes with asthma (p = 0.011 and p = 0.036, respectively). In addition, direct comparison of the asthmatic population with the RSV population revealed significant differences, both for -781C/T alone (p = 0.034) and IL8 haplotypes (p = 0.005). The amino acid variants in IL8RA were evenly distributed in between all three populations.

Conclusion

We conclude from our data that IL8 might play a role in the genetic predisposition to asthma and that these effects are different or even opposite to the effects on severe RSV diseases. Furthermore, IL8RA is unlikely to play a major role in the genetics of either disease.