bluuebunny/crossref_metadata_2025 huggingface dataset:
The composition, phase structure and tribological properties of H13 steel implanted with Mo
Authors: Yang J. H. , Zhang T. H.
Published: November 2006

Mo ions extracted from a metal vapor vacuum arc ion source were implanted into H13 steel with a high implantation dose of 5 × 1017 cm−2 and a pulsed ion beam flux of about 300 μA cm−2. An optical interference microscopy and pin on disc apparatus investigated the wear and friction characteristics of the steel. The Mo concentration depth profile was measured by using Rutherford backscattering spectroscopy. It was observed by X-ray photoelectron spectroscopy and grazing angle X-ray diffraction that carbide of Mo appeared in the doped region. The concentration depth profile and microstructure analysis could serve to illuminate the wear resistance improvement mechanisms of the Mo implanted steel.
Surface changes of plasma sprayed hydroxyapatite coatings before and after heat treatment
Authors: Chen Y. M. , Lu Y. P. , Li M. S.
Published: November 2006

Plasma sprayed and heat treated hydroxyapatite (HA) coatings, produced from fine HA powder (38–75 μm) under a spraying power of 45 kW (in short FCs) and coarse HA powder (75–106 μm) under a spraying power of 35 kW, (in short CCs) have been investigated, especially in terms of their surface characteristics. The X-ray diffraction results show that most of amorphous and decomposed phases transform into crystalline HA and the crystallinities of coatings are improved. The surface morphology of the coatings has been examined by electron probe microanalyser and field emission scanning electron microscope. At high magnifications the as sprayed FCs, with new nanosize particles and a netlike aggregated lamellar texture are observed on the surface. After heat treatment at 650°C, the nanograde particles of FCs have a tendency to grow and increase in quantity. While the netlike aggregation disperses into a uniform petal-like texture similar to a porous structure with a high surface roughness. Energy dispersive spectra show that these particles and netlike structure are primarily composed of calcium and phosphorous with adequate amount of oxygen and the Ca/P ratio is 1·75, i.e. exceeding that of pure HA.
Effect of substrate preparation on flattening of plasma sprayed aluminium bronze powders
Authors: Christoulis D. K. , Pantelis D. I. , Borit F. , Guipont V. , Jeandin M.
Published: November 2006

Plasma spray coatings are produced by introducing powder particles of the material into a plasma plume, which melts and forwards them to the substrate. The flattening process of these individual molten droplets is one of the most critical factors as the coating quality strongly depends on the deposition of individual particles. Powders of aluminium bronze, a fine (−53 + 11 μ m) and a coarse one (−125 + 45 μm) were plasma sprayed onto stainless steel substrates (AISI 304L) under atmospheric condition with three different substrate temperatures (25, 165 and 270°C). Two different ranges of surface roughness Ra were used: mirror polished substrates with about 0·01–0·03 μm and grit blasted substrates with about 1·89–2·43 μm. A scanning electron microscopy equipped with energy dispersive spectrometry system and an electron probe microanalysis, were used in order to study the splat morphology and the chemical composition of the splats.
Surface characterisation studies of nickel–chromium PVD: EB evaporated low carbon steel samples
Authors: Subramanian B. , Jayachandran M. , Jayakrishnan S.
Published: November 2006

Increasing concern over toxic wastes produced by nickel–chromium (Ni–Cr) plating industries has resulted in strong research efforts to replace conventional plating by physical vapour deposition techniques like evaporation and sputtering. Ni–Cr coatings on mild steel substrates produced by an electron beam evaporation process with layer thickness of ∼8–10 m m have been investigated with regard to the structural and corrosion properties. The structure of the coating was evaluated by X-ray diffractometer (XRD). The (110) Cr and (200) Ni predominant peaks with the crystallite size in the range of 25–30 nm was observed from XRD pattern. The electrochemical polarisation studies performed on samples showed the corrosion resistant nature of the evaporated Cr coating with Ni underlayer on mild steel substrates. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to investigate the surface characteristics of the samples before and after the electrochemical corrosion tests. The localised corrosion through a micropore in the evaporated Cr deposit and its penetration to the Ni layer was observed from SEM. The smaller change in roughness observed from AFM reflects the resistance of this coating to corrosion breakdown.
Effects of thermochemical treatments on properties of maraging steels
Authors: Cajner F. , Landek D. , Šolić S. , Cajner H.
Published: November 2006

Effects of such thermochemical processes as carburising, nitriding and boriding on properties of maraging steel grades have been investigated. Despite certain improvements in the properties of the obtained surface, at present, carburising and boriding cannot be recommended owing to problems in the layer quality and difficulties in dimension control processes. Nitriding has proved to be the most suitable process and subsequent surfacing with a TiN layer on the previously nitrided substratum of maraging steel provided additional improvement in properties.
The effect of deoxygenation on whole-cell conductance of red blood cells from healthy individuals and patients with sickle cell disease
Authors: Browning Joseph A. , Staines Henry M. , Robinson Hannah C. , Powell Trevor , Ellory J. Clive , Gibson John S.
Published: November 2006

Red blood cells from patients with sickle cell disease (SCD) exhibit increased electrogenic cation permeability, particularly following deoxygenation and hemoglobin (Hb) polymerisation. This cation permeability, termed Psickle, contributes to cellular dehydration and sickling, and its inhibition remains a major goal for SCD treatment. Nevertheless, its characteristics remain poorly defined, its molecular identity is unknown, and effective inhibitors have not been established. Here, patch-clamp methodology was used to record whole-cell currents in single red blood cells from healthy individuals and patients with SCD. Oxygenated normal red blood cells had a low membrane conductance, unaffected by deoxygenation. Oxygenated HbS cells had significantly increased conductance and, on deoxygenation, showed a further rise in membrane conductance. The deoxygenation-induced pathway was variable in magnitude. It had equal permeability to Na+ and K+, but was less permeable to NMDG+ and Cl−. Conductance to Ca2+ was also of a similar magnitude to that of monovalent cations. It was inhibited by DIDS (100 μM), Zn2+ (100 μM), and by Gd3+ (IC50 of approximately 2 μM). It therefore shares some properties with Psickle. These findings represent the first electrical recordings of single HbS cells and will facilitate progress in understanding altered red blood cell cation transport characteristics of SCD.
HGF inhibits BMP-induced osteoblastogenesis: possible implications for the bone disease of multiple myeloma
Authors: Standal Therese , Abildgaard Niels , Fagerli Unn-Merete , Stordal Berit , Hjertner Øyvind , Borset Magne , Sundan Anders
Published: December 2006

The bone disease in multiple myeloma is caused by an uncoupling of bone formation from bone resorption. A key difference between patients with and patients without osteolytic lesion is that the latter have fewer and less active osteoblasts. Hepatocyte growth factor (HGF) is often produced by myeloma cells and is found at high concentrations in the bone marrow of patients with multiple myeloma. Here we show that HGF inhibited bone morphogenetic protein (BMP)–induced in vitro osteoblastogenesis. Thus, HGF inhibited BMP-induced expression of alkaline phosphatase in human mesenchymal stem cells (hMSCs) and the murine myoid cell line C2C12, as well as mineralization by hMSCs. Furthermore, the expression of the osteoblast-specific transcription factors Runx2 and Osterix was reduced by HGF treatment. HGF promoted proliferation of hMSCs, and the BMP-induced halt in proliferation was overridden by HGF, keeping the cells in a proliferative, undifferentiating state. BMP-induced nuclear translocation of receptor-activated Smads was inhibited by HGF, providing a possible explanation of how HGF inhibits BMP signaling. The in vitro data were supported by the observation of a negative correlation between HGF and a marker of osteoblast activity, bone-specific alkaline phosphatase (rho = −0.45, P = .008), in sera from 34 patients with myeloma. These observations suggest that HGF inhibits bone formation in multiple myeloma.
CD10−MUM1+ follicular lymphoma lacks BCL2 gene translocation and shows characteristic biologic and clinical features
Authors: Karube Kennosuke , Guo Ying , Suzumiya Junji , Sugita Yasuo , Nomura Yuko , Yamamoto Kohei , Shimizu Kei , Yoshida Shirou , Komatani Hideki , Takeshita Morishige , Kikuchi Masahiro , Nakamura Naoya , Takasu Osamu , Arakawa Fumiko , Tagawa Hiroyuki , Seto Masao , Ohshima Koichi
Published: December 2006

CD10 and MUM1 are representative B cell differentiation markers. Follicular lymphoma (FL) is usually positive for CD10 and negative for MUM1. In this study, however, we compared 22 FLs with peculiar phenotype CD10−MUM1+ with 119 typical CD10+MUM1− FLs. All CD10−MUM1+ FL patients exhibited follicular structure with follicular dendritic meshwork, and a high rate of somatic hypermutation and ongoing mutation, similar to typical FL. However, CD10−MUM1+ FLs were encountered frequently in the elderly compared with CD10+MUM1− typical FLs (67.0 versus 58.7 years, P < .01), showed high grade (grade 3A or 3B) morphology (91% versus 17%, P < .001), diffuse proliferation (59% vs 19%, P < .001), and lacked BCL2/IGH translocation (5% versus 92.5%, P < .001), which is the most characteristic aberration in FL, and 88% showed BCL6 gene abnormalities (translocation or amplification). Our results indicate that CD10−MUM1+ FL is different from typical FL with respect to biologic and clinical features.
Transbronchial and transoesophageal (ultrasound-guided) needle aspirations for the analysis of mediastinal lesions
Authors: Herth F. J. F. , Rabe K. F. , Gasparini S. , Annema J. T.
Published: November 2006

A tissue diagnosis of mediastinal nodes is frequently needed for accurate lung cancer staging as well as the assessment of mediastinal masses. Transbronchial needle aspiration (TBNA) is a safe procedure that is performed during routine bronchoscopy. Provided mediastinal metastases are confirmed, TBNA has a high impact on patient management. Unfortunately, TBNA remains underused in current daily practice, mainly due to the lack of real-time needle visualisation. The introduction of echo-endoscopes has overcome this problem.

Endobronchial ultrasound-guided TBNA (EBUS-TBNA) allows real-time controlled tissue sampling of paratracheal, subcarinal and hilar lymph nodes. Mediastinal lymph nodes located adjacent to the oesophagus can be assessed by transoesophageal ultrasound-guided fine needle aspiration (EUS-FNA). Owing to the complementary reach of EBUS-TBNA and EUS-FNA in assessing different regions of the mediastinum, recent studies suggest that complete and accurate mediastinal staging can be achieved by the combination of both procedures.

It is expected that implementation of minimally invasive endoscopic methods of endobronchial ultrasound-guided transbronchial needle aspiration and transoesophageal ultrasound-guided fine needle aspiration will reduce the need for surgical staging of lung cancer significantly.
Severe airflow obstruction and eosinophilic lung disease after Stevens–Johnson syndrome
Authors: Shah A. P. , Xu H. , Sime P. J. , Trawick D. R.
Published: November 2006

Respiratory involvement is a frequent complication of Stevens–Johnson syndrome (SJS). However, there are very few convincing reports of persistent pulmonary sequelae, as demonstrated by spirometry, radiology and pathology.

The current study presents a case of a 13-yr-old female with T-cell acute lymphocytic leukaemia who developed persistent, severe, obstructive lung disease following an episode of SJS.

A lung biopsy demonstrated bronchiolar submucosal fibrosis consistent with constrictive bronchiolitis, as well as eosinophilic micro-abscesses, which, to the current authors’ knowledge, has not been previously described.

The present study illustrates specific histopathological features that highlight a possible association between Stevens–Johnson syndrome, constrictive bronchiolitis and eosinophilic micro-abscesses. The eosinophils may be associated with permanent mucosal damage, as seen in the present case, by releasing mediators that have a pro-fibrogenetic role. However, further investigation is warranted.
Genotype-corrected reference values for serum angiotensin-converting enzyme
Authors: Biller H. , Zissel G. , Ruprecht B. , Nauck M. , Busse Grawitz A. , Müller-Quernheim J.
Published: November 2006

The deletion (D)/insertion (I) polymorphism in intron 16 of the angiotensin-converting enzyme (ACE) gene has the greatest impact on serum ACE level in Caucasians of any factor yet discovered. The aim of the present study was to establish new ACE genotype-corrected normal ranges for serum ACE level in a population of central European origin.

After a medical examination, 159 healthy Caucasians volunteered to donate blood for the study. ACE genotypes were assessed by PCR and serum ACE levels were determined using two different kinetic tests.

The distribution of the D/I polymorphism of the ACE gene was in accordance with the Hardy–Weinberg equilibrium. Serum ACE levels and ACE genotypes correlated significantly, with the highest serum ACE levels in subjects with ACE genotype D/D, and the lowest serum ACE levels in subjects with genotype I/I (mean±sd,assay 1: D/D 59.3±15.1 U·L-1, D/I 45.5±15.2 U·L-1, I/I 34.8±13.7 U·L-1; assay 2: D/D 43.7±14.1 U·L-1, D/I 33.7±12.1 U·L-1, I/I 25.4±9.5 U·L-1). Although they gave different absolute values of serum ACE levels, the results of the two test kits correlated significantly.

In conclusion, the present authors recommend the use of new, genotype-specific reference values for serum angiotensin-converting enzyme levels, especially to improve the sensitivity and specificity of tests for angiotensin-converting enzyme in the follow-up of sarcoidosis.
Respiratory heat and moisture loss is associated with eosinophilic inflammation in asthma
Authors: Noble D. D. , McCafferty J. B. , Greening A. P. , Innes J. A.
Published: November 2006

Increased mucosal vascularity is a hallmark of airway inflammation in asthma. It was hypothesised that this would lead to a detectable increase in respiratory heat and moisture loss (RHML), which would reflect the degree of airway inflammation present.

A total of 23 subjects with asthma and 18 healthy controls had RHML measured in a cross-sectional study. The measurements were made using a device that combines temperature and humidity measurement during inspiration and expiration and allows precise control over inspirate conditions and ventilatory pattern. The subjects with asthma underwent parallel measurements of exhaled nitric oxide, sputum eosinophil percentage and exhaled breath condensate pH.

Mean±sdRHML was elevated in patients with asthma (98.1±7.3 J·L−1) compared with control subjects (91.9±4.5 J·L−1). RHML measurement in asthma correlated with sputum eosinophil percentage.

This novel correlation between thermal and cellular measurements in asthma suggests that both of these noninvasive indices are sensitive to the degree of underlying chronic airway inflammation.
Treatment failure in tuberculosis
Authors: Panickar J. R. , Hoskyns W.
Published: November 2006

Treatment of latent tuberculosis (TB) infection with 3 months of rifampicin/isoniazid is a major part of preventive TB programmes. The effectiveness of treatment of latent TB infection can only be assessed by rates of subsequent breakdown and there are few outcome data for this combination of rifampicin/isoniazid. Therefore, the aim of the present study was to estimate the failure rate following treatment for the latent TB infection.

A questionnaire survey was carried out in all parents of children aged <16 yrs who completed treatment for latent TB infection at Leicester Royal Infirmary (Leicester, UK) over the period 1997–2003. Cases of treatment failure were identified by reviewing all re-referrals to the clinic, identifying children developing TB while on treatment and by postal questionnaire to all patients discharged.

Of the 400 eligible children, 344 (86%) replied. Three children who had latent TB infection subsequently developed TB disease over the time period. Of those three patients, one developed chest radiograph signs at the end of treatment and two presented with symptoms within 2 yrs of completing treatment. Overall, the mean treatment failure rate was 0.87% (95% confidence interval 0.3–2.5) or 2.2 cases per 1,000 patient-yrs.

In conclusion, rates of tuberculosis breakdown after treatment for latent tuberculosis infection with 3 months rifampicin/isoniazid are acceptably low.
NT-proBNP can be used to detect right ventricular systolic dysfunction in pulmonary hypertension
Authors: Blyth K. G. , Groenning B. A. , Mark P. B. , Martin T. N. , Foster J. E. , Steedman T. , Morton J. J. , Dargie H. J. , Peacock A. J.
Published: November 2006

Right ventricular systolic dysfunction (RVSD) at baseline (pre-treatment) predicts early death in patients with pulmonary hypertension (PH). However, RVSD can only be detected reliably by prohibitively invasive or expensive techniques. N-terminal B-type natriuretic peptide concentration ([NT-proBNP]) correlates with RV function in PH; however, an [NT-proBNP] threshold that indicates RVSD in individual patients has not previously been determined.

Twenty-five patients with PH (pulmonary arterial hypertension (n = 19) or chronic thromboembolic PH (n = 6)) underwent cardiovascular magnetic resonance (CMR) imaging and NT-proBNP measurement at baseline. [NT-proBNP] was correlated against RV dimensions and ejection fraction (RVEF) measured directly by CMR imaging. The ability of NT-proBNP to detect RVSD (defined as a CMR-derived RVEF >2sds below control values) was tested and predictors of [NT-proBNP] identified.

[NT-proBNP] correlated negatively with RVEF. RVSD was present in nine out of 25 patients. An [NT-proBNP] threshold of 1,685 pg·mL−1was sensitive (100%) and specific (94%) in detecting RVSD. RVEF and RV mass index independently predicted [NT-proBNP].

In pulmonary hypertension, a baseline N-terminal B-type natriuretic peptide concentration of >1,685 ng·L−1suggests right ventricular systolic dysfunction, and thus an increased risk of early death. N-terminal B-type natriuretic peptide could prove useful as an objective, noninvasive means of identifying patients with pulmonary hypertension who have right ventricular systolic dysfunction at presentation.
Mortality in COPD: role of comorbidities
Authors: Sin D. D. , Anthonisen N. R. , Soriano J. B. , Agusti A. G.
Published: November 2006

Chronic obstructive pulmonary disease (COPD) represents an increasing burden throughout the world. COPD-related mortality is probably underestimated because of the difficulties associated with identifying the precise cause of death. Respiratory failure is considered the major cause of death in advanced COPD. Comorbidities such as cardiovascular disease and lung cancer are also major causes and, in mild-to-moderate COPD, are the leading causes of mortality.

The links between COPD and these conditions are not fully understood. However, a link through the inflammation pathway has been suggested, as persistent low-grade pulmonary and systemic inflammation, both known risk factors for cardiovascular disease and cancer, are present in COPD independent of cigarette smoking.

Lung-specific measurements, such as forced expiratory volume in one second (FEV1), predict mortality in COPD and in the general population. However, composite tools, such as health-status measurements (e.g.St George's Respiratory Questionnaire) and the BODE index, which incorporates Body mass index, lung function (airflow Obstruction), Dyspnoea and Exercise capacity, predict mortality better than FEV1alone. These multidimensional tools may be more valuable because, unlike predictive approaches based on single parameters, they can reflect the range of comorbidities and the complexity of underlying mechanisms associated with COPD.

The current paper reviews the role of comorbidities in chronic obstructive pulmonary disease mortality, the putative underlying pathogenic link between chronic obstructive pulmonary disease and comorbid conditions (i.e.inflammation), and the tools used to predict chronic obstructive pulmonary disease mortality.
Evolution and respiratory genetics
Authors: Le Souëf P. N. , Candelaria P. , Goldblatt J.
Published: November 2006

Evolution is a plausible explanation for between-population differences in particular allele frequencies if: the genes involved have related functions; the heterogeneous alleles involved have similar functional consequences; the involved genes are not linked chromosomally; and the patterns observed would result in a biologically plausible, survival-enhancing gene–environment interaction. However, possible evolutionary effects have to be differentiated from founder effects and random genetic drift.

The current authors have noted the existence of a consistent pattern of allelic frequencies in genes related to T-helper 2 (Th2) immune responses in humans of different ancestral backgrounds, residing in climatically similar regions. Th2 responses are thought to have evolved in mammals to resist infection by parasites, particularly helminths. Modern man arose in tropical Africa where helminths thrived. Relatively recently, humans migrated to cooler or drier climates where most helminths struggled to reproduce. The genetic tendency to strong Th2 responses may have become a health liability, the reduction in risk from parasites being counterbalanced by an increased inherited propensity to atopic or allergic diseases.

The pattern noted by the present authors includes specific alleles of interleukin-4 and its receptor, interleukin-13, interleukin-10, the β chain of the high-affinity receptor for immunoglobulin E, the β1-adrenergic receptor, and the alpha chain of tumour necrosis factor. These population-specific polymorphism profiles are likely to be relevant in current disease patterns. The high incidence of asthma in migrants from tropical locations to affluent temperate countries is likely to be related to these patterns. Of even more concern is the possibility that increasing westernisation among the ∼2 billion people living in the tropics will produce rapidly increasing levels of asthma, as these populations have a high genetic predisposition to allergic disease.
Dynamic variable selection in SNP genotype autocalling from APEX microarray data
Authors: Podder Mohua , Welch William J , Zamar Ruben H , Tebbutt Scott J
Published: November 2006

Background

Single nucleotide polymorphisms (SNPs) are DNA sequence variations, occurring when a single nucleotide – adenine (A), thymine (T), cytosine (C) or guanine (G) – is altered. Arguably, SNPs account for more than 90% of human genetic variation. Our laboratory has developed a highly redundant SNP genotyping assay consisting of multiple probes with signals from multiple channels for a single SNP, based on arrayed primer extension (APEX). This mini-sequencing method is a powerful combination of a highly parallel microarray with distinctive Sanger-based dideoxy terminator sequencing chemistry. Using this microarray platform, our current genotype calling system (known as SNP Chart) is capable of calling single SNP genotypes by manual inspection of the APEX data, which is time-consuming and exposed to user subjectivity bias.

Results

Using a set of 32 Coriell DNA samples plus three negative PCR controls as a training data set, we have developed a fully-automated genotyping algorithm based on simple linear discriminant analysis (LDA) using dynamic variable selection. The algorithm combines separate analyses based on the multiple probe sets to give a final posterior probability for each candidate genotype. We have tested our algorithm on a completely independent data set of 270 DNA samples, with validated genotypes, from patients admitted to the intensive care unit (ICU) of St. Paul's Hospital (plus one negative PCR control sample). Our method achieves a concordance rate of 98.9% with a 99.6% call rate for a set of 96 SNPs. By adjusting the threshold value for the final posterior probability of the called genotype, the call rate reduces to 94.9% with a higher concordance rate of 99.6%. We also reversed the two independent data sets in their training and testing roles, achieving a concordance rate up to 99.8%.

Conclusion

The strength of this APEX chemistry-based platform is its unique redundancy having multiple probes for a single SNP. Our model-based genotype calling algorithm captures the redundancy in the system considering all the underlying probe features of a particular SNP, automatically down-weighting any 'bad data' corresponding to image artifacts on the microarray slide or failure of a specific chemistry. In this regard, our method is able to automatically select the probes which work well and reduce the effect of other so-called bad performing probes in a sample-specific manner, for any number of SNPs.
BioMoby extensions to the Taverna workflow management and enactment software
Authors: Kawas Edward , Senger Martin , Wilkinson Mark D
Published: November 2006

Background

As biology becomes an increasingly computational science, it is critical that we develop software tools that support not only bioinformaticians, but also bench biologists in their exploration of the vast and complex data-sets that continue to build from international genomic, proteomic, and systems-biology projects. The BioMoby interoperability system was created with the goal of facilitating the movement of data from one Web-based resource to another to fulfill the requirements of non-expert bioinformaticians. In parallel with the development of BioMoby, the European myGrid project was designing Taverna, a bioinformatics workflow design and enactment tool. Here we describe the marriage of these two projects in the form of a Taverna plug-in that provides access to many of BioMoby's features through the Taverna interface.

Results

The exposed BioMoby functionality aids in the design of "sensible" BioMoby workflows, aids in pipelining BioMoby and non-BioMoby-based resources, and ensures that end-users need only a minimal understanding of both BioMoby, and the Taverna interface itself. Users are guided through the construction of syntactically and semantically correct workflows through plug-in calls to the Moby Central registry. Moby Central provides a menu of only those BioMoby services capable of operating on the data-type(s) that exist at any given position in the workflow. Moreover, the plug-in automatically and correctly connects a selected service into the workflow such that users are not required to understand the nature of the inputs or outputs for any service, leaving them to focus on the biological meaning of the workflow they are constructing, rather than the technical details of how the services will interoperate.

Conclusion

With the availability of the BioMoby plug-in to Taverna, we believe that BioMoby-based Web Services are now significantly more useful and accessible to bench scientists than are more traditional Web Services.
Gelatinases, endonuclease and Vascular Endothelial Growth Factor during development and regression of swine luteal tissue
Authors: Ribeiro Luciana Andrea , Turba Maria Elena , Zannoni Augusta , Bacci Maria Laura , Forni Monica
Published: November 2006

Background

The development and regression of corpus luteum (CL) is characterized by an intense angiogenesis and angioregression accompanied by luteal tissue and extracellular matrix (ECM) remodelling. Vascular Endothelial Growth Factor (VEGF) is the main regulator of angiogenesis, promoting endothelial cell mitosis and differentiation. After the formation of neovascular tubes, the remodelling of ECM is essential for the correct development of CL, particularly by the action of specific class of proteolytic enzymes known as matrix metalloproteinases (MMPs). During luteal regression, characterized by an apoptotic process and successively by an intense ECM and luteal degradation, the activation of Ca++/Mg++-dependent endonucleases and MMPs activity are required. The levels of expression and activity of VEGF, MMP-2 and -9, and Ca++/Mg++-dependent endonucleases throughout the oestrous cycle and at pregnancy were analyzed.

Results

Different patterns of VEGF, MMPs and Ca++/Mg++-dependent endonuclease were observed in swine CL during different luteal phases and at pregnancy. Immediately after ovulation, the highest levels of VEGF mRNA/protein and MMP-9 activity were detected. On days 5–14 after ovulation, VEGF expression and MMP-2 and -9 activities are at basal levels, while Ca++/Mg++-dependent endonuclease levels increased significantly in relation to day 1. Only at luteolysis (day 17), Ca++/Mg++-dependent endonuclease and MMP-2 spontaneous activity increased significantly. At pregnancy, high levels of MMP-9 and VEGF were observed.

Conclusion

Our findings, obtained from a precisely controlled in vivo model of CL development and regression, allow us to determine relationships among VEGF, MMPs and endonucleases during angiogenesis and angioregression. Thus, CL provides a very interesting model for studying factors involved in vascular remodelling.
Identification of a gonadotropin-releasing hormone receptor orthologue in Caenorhabditis elegans
Authors: Vadakkadath Meethal Sivan , Gallego Miguel J , Haasl Ryan J , Petras Stephen J , Sgro Jean-Yves , Atwood Craig S
Published: November 2006

Background

The Caenorhabditis elegans genome is known to code for at least 1149 G protein-coupled receptors (GPCRs), but the GPCR(s) critical to the regulation of reproduction in this nematode are not yet known. This study examined whether GPCRs orthologous to human gonadotropin-releasing hormone receptor (GnRHR) exist in C. elegans.

Results

Our sequence analyses indicated the presence of two proteins in C. elegans, one of 401 amino acids [GenBank: NP_491453; WormBase: F54D7.3] and another of 379 amino acids [GenBank: NP_506566; WormBase: C15H11.2] with 46.9% and 44.7% nucleotide similarity to human GnRHR1 and GnRHR2, respectively. Like human GnRHR1, structural analysis of the C. elegans GnRHR1 orthologue (Ce-GnRHR) predicted a rhodopsin family member with 7 transmembrane domains, G protein coupling sites and phosphorylation sites for protein kinase C. Of the functionally important amino acids in human GnRHR1, 56% were conserved in the C. elegans orthologue. Ce-GnRHR was actively transcribed in adult worms and immunoanalyses using antibodies generated against both human and C. elegans GnRHR indicated the presence of a 46-kDa protein, the calculated molecular mass of the immature Ce-GnRHR. Ce-GnRHR staining was specifically localized to the germline, intestine and pharynx. In the germline and intestine, Ce-GnRHR was localized specifically to nuclei as revealed by colocalization with a DNA nuclear stain. However in the pharynx, Ce-GnRHR was localized to the myofilament lattice of the pharyngeal musculature, suggesting a functional role for Ce-GnRHR signaling in the coupling of food intake with reproduction. Phylogenetic analyses support an early evolutionary origin of GnRH-like receptors, as evidenced by the hypothesized grouping of Ce-GnRHR, vertebrate GnRHRs, a molluscan GnRHR, and the adipokinetic hormone receptors (AKHRs) and corazonin receptors of arthropods.

Conclusion

This is the first report of a GnRHR orthologue in C. elegans, which shares significant similarity with insect AKHRs. In vertebrates, GnRHRs are central components of the reproductive endocrine system, and the identification of a GnRHR orthologue in C. elegans suggests the potential use of C. elegans as a model system to study reproductive endocrinology.
Genomewide identification of pheromone-targeted transcription in fission yeast
Authors: Xue-Franzén Yongtao , Kjærulff Søren , Holmberg Christian , Wright Anthony , Nielsen Olaf
Published: November 2006

Background

Fission yeast cells undergo sexual differentiation in response to nitrogen starvation. In this process haploid M and P cells first mate to form diploid zygotes, which then enter meiosis and sporulate. Prior to mating, M and P cells communicate with diffusible mating pheromones that activate a signal transduction pathway in the opposite cell type. The pheromone signalling orchestrates mating and is also required for entry into meiosis.

Results

Here we use DNA microarrays to identify genes that are induced by M-factor in P cells and by P-factor in M-cells. The use of a cyr1 genetic background allowed us to study pheromone signalling independently of nitrogen starvation. We identified a total of 163 genes that were consistently induced more than two-fold by pheromone stimulation. Gene disruption experiments demonstrated the involvement of newly discovered pheromone-induced genes in the differentiation process. We have mapped Gene Ontology (GO) categories specifically associated with pheromone induction. A direct comparison of the M- and P-factor induced expression pattern allowed us to identify cell-type specific transcripts, including three new M-specific genes and one new P-specific gene.

Conclusion

We found that the pheromone response was very similar in M and P cells. Surprisingly, pheromone control extended to genes fulfilling their function well beyond the point of entry into meiosis, including numerous genes required for meiotic recombination. Our results suggest that the Ste11 transcription factor is responsible for the majority of pheromone-induced transcription. Finally, most cell-type specific genes now appear to be identified in fission yeast.
Male circumcision, religion, and infectious diseases: an ecologic analysis of 118 developing countries
Authors: Drain Paul K , Halperin Daniel T , Hughes James P , Klausner Jeffrey D , Bailey Robert C
Published: November 2006

Background

Both religious practices and male circumcision (MC) have been associated with HIV and other sexually-transmitted infectious diseases. Most studies have been limited in size and have not adequately controlled for religion, so these relationships remain unclear.

Methods

We evaluated relationships between MC prevalence, Muslim and Christian religion, and 7 infectious diseases using country-specific data among 118 developing countries. We used multivariate linear regression to describe associations between MC and cervical cancer incidence, and between MC and HIV prevalence among countries with primarily sexual HIV transmission.

Results

Fifty-three, 14, and 51 developing countries had a high (>80%), intermediate (20–80%), and low (<20%) MC prevalence, respectively. In univariate analyses, MC was associated with lower HIV prevalence and lower cervical cancer incidence, but not with HSV-2, syphilis, nor, as expected, with Hepatitis C, tuberculosis, or malaria. In multivariate analysis after stratifying the countries by religious groups, each categorical increase of MC prevalence was associated with a 3.65/100,000 women (95% CI 0.54-6.76, p = 0.02) decrease in annual cervical cancer incidence, and a 1.84-fold (95% CI 1.36-2.48, p < 0.001) decrease in the adult HIV prevalence among sub-Saharan African countries. In separate multivariate analyses among non-sub-Saharan African countries controlling for religion, higher MC prevalence was associated with a 8.94-fold (95% CI 4.30-18.60) decrease in the adult HIV prevalence among countries with primarily heterosexual HIV transmission, but not, as expected, among countries with primarily homosexual or injection drug use HIV transmission (p = 0.35).

Conclusion

Male circumcision was significantly associated with lower cervical cancer incidence and lower HIV prevalence in sub-Saharan Africa, independent of Muslim and Christian religion. As predicted, male circumcision was also strongly associated with lower HIV prevalence among countries with primarily heterosexual HIV transmission, but not among countries with primarily homosexual or injection drug use HIV transmission. These findings strengthen the reported biological link between MC and some sexually transmitted infectious diseases, including HIV and cervical cancer.
In vitro antibacterial activity of some plant essential oils
Authors: Prabuseenivasan Seenivasan , Jayakumar Manickkam , Ignacimuthu Savarimuthu
Published: November 2006

Background:

To evaluate the antibacterial activity of 21 plant essential oils against six bacterial species.

Methods:

The selected essential oils were screened against four gram-negative bacteria (Escherichia coli,Klebsiella pneumoniae,Pseudomonas aeruginosa,Proteus vulgaris) and two gram-positive bacteriaBacillus subtilisandStaphylococcus aureusat four different concentrations (1:1, 1:5, 1:10 and 1:20) using disc diffusion method. The MIC of the active essential oils were tested using two fold agar dilution method at concentrations ranging from 0.2 to 25.6 mg/ml.

Results:

Out of 21 essential oils tested, 19 oils showed antibacterial activity against one or more strains. Cinnamon, clove, geranium, lemon, lime, orange and rosemary oils exhibited significant inhibitory effect. Cinnamon oil showed promising inhibitory activity even at low concentration, whereas aniseed, eucalyptus and camphor oils were least active against the tested bacteria. In general,B. subtiliswas the most susceptible. On the other hand,K. pneumoniaeexhibited low degree of sensitivity.

Conclusion:

Majority of the oils showed antibacterial activity against the tested strains. However Cinnamon, clove and lime oils were found to be inhibiting both gram-positive and gram-negative bacteria. Cinnamon oil can be a good source of antibacterial agents.
Indirect exclusion of four candidate genes for generalized progressive retinal atrophy in several breeds of dogs
Authors: Lippmann Tanja , Pasternack Sandra M , Kraczyk Britta , Dudek Sabine E , Dekomien Gabriele
Published: November 2006

Background

Generalized progressive retinal atrophy (gPRA) is a hereditary ocular disorder with progressive photoreceptor degeneration in dogs. Four retina-specific genes, ATP binding cassette transporter retina (ABCA 4), connexin 36 (CX 36), c-mer tyrosin kinase receptor (MERTK) and photoreceptor cell retinol dehydrogenase (RDH 12) were investigated in order to identify mutations leading to autosomal recessive (ar) gPRA in 29 breeds of dogs.

Results

Mutation screening was performed initially by PCR and single strand conformation polymorphism (SSCP) analysis, representing a simple method with comparatively high reliability for identification of sequence variations in many samples. Conspicuous banding patterns were analyzed via sequence analyses in order to detect the underlying nucleotide variations. No pathogenetically relevant mutations were detected in the genes ABCA 4, CX 36, MERTK and RDH 12 in 71 affected dogs of 29 breeds. Yet 30 new sequence variations were identified, both, in the coding regions and intronic sequences. Many of the sequence variations were in heterozygous state in affected dogs.

Conclusion

Based on the ar transmittance of gPRA in the breeds investigated, informative sequence variations provide evidence allowing indirect exclusion of pathogenetic mutations in the genes ABCA 4 (for 9 breeds), CX 36 (for 12 breeds), MERTK (for all 29 breeds) and RDH 12 (for 9 breeds).
The mechanism for stochastic resonance enhancement of mammalian auditory information processing
Authors: Hong Dawei , Martin Joseph V , Saidel William M
Published: December 2006

Background

In a mammalian auditory system, when intrinsic noise is added to a subthreshold signal, not only can the resulting noisy signal be detected, but also the information carried by the signal can be completely recovered. Such a phenomenon is called stochastic resonance (SR). Current analysis of SR commonly employs the energies of the subthreshold signal and intrinsic noise. However, it is difficult to explain SR when the energy addition of the signal and noise is not enough to lift the subthreshold signal over the threshold. Therefore, information modulation has been hypothesized to play a role in some forms of SR in sensory systems. Information modulation, however, seems an unlikely mechanism for mammalian audition, since it requires significanta prioriknowledge of the characteristics of the signal.

Results

We propose that the analysis of SR cannot rely solely on the energies of a subthreshold signal and intrinsic noise or on information modulation. We note that a mammalian auditory system expends energy in the processing of a noisy signal. A part of the expended energy may therefore deposit into the recovered signal, lifting it over threshold. We propose a model that in a rigorous mathematical manner expresses this new theoretical viewpoint on SR in the mammalian auditory system and provide a physiological rationale for the model.

Conclusion

Our result indicates that the mammalian auditory system may be more active than previously described in the literature. As previously recognized, when intrinsic noise is used to generate a noisy signal, the energy carried by the noise is added to the original subthreshold signal. Furthermore, our model predicts that the system itself should deposit additional energy into the recovered signal. The additional energy is used in the processing of the noisy signal to recover the original subthreshold signal.
Maternal position during the first stage of labor: a systematic review
Authors: Souza João P , Miquelutti Maria A , Cecatti Jose G , Makuch Maria Y
Published: November 2006

Background

Policy makers and health professionals are progressively using evidence-based rationale to guide their decisions. There has long been controversy regarding which maternal position is more appropriate during the first stage of labor. This problem has been examined often and repeatedly and the optimal recommendation remains unclear.

Methods

This is a systematic review of the effect of maternal position during the first stage of labor. The main question addressed here is: Does encouraging women to adopt an upright position or to ambulate during the first stage of labor reduce the duration of this stage? All randomized controlled trials carried out to assess this effect were taken into consideration in this review. The following electronic databases were accessed to identify studies: MEDLINE, Popline, the Scientific Electronic Library On-line and the Latin American and Caribbean Health Science Information. Citation eligibility was independently assessed by two reviewers. The methodological quality of each trial was also evaluated independently by two reviewers and a trial under consideration was included only when consensus had been attained. Allocation concealment and screening for the occurrence of attrition, performance and detection biases were considered when studies were appraised. The decision whether to perform data pooling was based on the clinical similarity of studies.

Results

The search strategy resulted in 260 citations, of which 18 were assessed in full-text. Nine eligible randomized controlled trials were included in the systematic review. Randomization methods were not fully described in eight studies. The allocation concealment was considered adequate in four studies and unclear in five. The investigators pooled the data from seven studies in which the length of the first stage of labor and results were in favor of the intervention, but the high level of heterogeneity (I2 = 88.4%) impaired the meaning of this finding. The intervention did not affect other outcomes studied (mode of delivery, use of analgesia, labor augmentation and condition of the child at birth).

Conclusion

Adoption of the upright position or ambulation during first stage of labor may be safe, but considering the available evidence and its consistency, it cannot be recommended as an effective intervention to reduce duration of the first stage of labor.
Ageing is associated with a decline in peripheral blood CD56bright NK cells
Authors: Chidrawar Shivani M , Khan Naeem , Chan Y L Tracey , Nayak Laxman , Moss Paul AH
Published: November 2006

Background

Natural killer (NK) cells are cytotoxic lymphocytes that lack CD3 and express variable levels of CD16, CD56 and CD57. In recent years NK cells have been categorised into two major groups based on the level of CD56 expression. This phenotypic classification correlates with functional activity as CD56brightNK cells are the major cytokine producing subset whereas CD56dimNK cells exhibit greater cytotoxic activity. Previous studies have revealed a reduction in total NK cell numbers in association with ageing and this study sought to determine the potential influence of ageing on the number of NK cell subsets within peripheral blood.

Results

The number of NK (CD56+CD3-) cells within peripheral blood did not change with increasing age. The number of CD56dimNK cells also remained stable with ageing. In contrast the absolute number of CD56brightNK cells within peripheral blood declined by 48% with ageing from a mean of 15.6/μl in individuals aged 20–40 years to 8.1/μl in those aged 60+ years (p = 0.0004).

Conclusion

The number of CD56brightNK cells within peripheral blood declines with age. As this population plays a central role in cytokine secretion during the innate immune response this decline may contribute to impaired immune regulation in elderly individuals
Does listening to the sound of yourself chewing increase your enjoyment of food?
Authors: Amos Kirsty E , Anari Shahram , Buswell Charlotte A , McNeill Emma J , Printza Athanasia , Ray Stephen J , Rustom Isam
Published: November 2006

Background

Anecdotal evidence suggests that listening to oneself eating results in a more pleasurable eating experience. Maximising the sensory experience of eating can result in increased oral intake and is potentially valuable in improving nutritional status in at-risk patients.

Objective

This pilot study investigates the association between listening to the sound of oneself eating and the consequences on enjoyment of eating.

Design

Prospective, randomized, controlled, cross-over trial of 10 fit, adult volunteers. Participants were timed eating a standardised amount of bread, and were randomized to eat in silence or whilst listening to their own amplified chewing and swallowing. Measurements of pulse and blood pressure were recorded throughout the procedure. Subjective pleasure scores were documented and the procedure repeated in the alternate study arm.

Results

There was no significant relationship demonstrated between listening to oneself chewing and the enjoyment of eating.

Conclusion

Although this small pilot study was unable to demonstrate a significant relationship between listening to oneself chewing and enjoyment of eating, other evidence suggests that distraction techniques have a beneficial effect on dietary intake. Such techniques can be applied in a clinical setting and further work in this area has valuable potential.