bluuebunny/crossref_metadata_2025 huggingface dataset:
Canadian Public Health Nurses' Job Satisfaction
Authors: Best Maureen F. , Thurston Norma E.
Published: May 2006

ABSTRACT
Objectives: This study was undertaken to test the applicability of using a standardized questionnaire for measuring public health nurse (PHN) job satisfaction and to determine whether or not scores changed over 30 months. The importance of establishing a method for ongoing measurement of PHN job satisfaction was underscored by changing directions in practice and an emphasis on building public health capacity.

Method: A 30‐month interval, repeated measures descriptive survey design was used.

Sample: A randomly selected sample of 87 PHNs employed within 1 Canadian regional health authority participated.

Measurement: The survey questionnaire, the Index of Worklife Satisfaction, was designed to measure the importance of and satisfaction with 6 components of job satisfaction.

Results: Pay and autonomy were the most important components; the order of the 4 remaining components changed from first to second surveys. Professional status, autonomy, and interaction were the most satisfying components; PHN satisfaction with professional status and interaction improved significantly over 30 months. A majority of subjects reported that direct client care/client response/making a difference were worklife aspects providing them with most satisfaction.

Conclusions: A valid, reliable questionnaire suitable for ongoing measurement was tested with PHNs, and baseline levels of their job satisfaction were established.
Access to care – what can the United States learn from other countries?*
Authors: Maas William R.
Published: May 2006

Abstract –  This paper briefly describes the US system for dental care services; asserts that there is much to be learned by considering the experience of other countries; identifies a few lessons that may be learned from comparisons with England, Australia, and other nations; and encourages the monitoring of outcomes associated with innovations in financing and delivery of services elsewhere. Oral health is affected by more factors than access to dental care. Because so many factors at the individual, environmental, and delivery system levels affect oral health, interpreting the findings from international studies is difficult. Furthermore, the findings of these international studies are confounded by significant intra‐country variation in outcomes and expectations. While public funding and the public provision of services (such as programs in schools or community health centers) can be powerful instruments of change, they have their limitations. Examination of all types of public subsidization of dental care may reveal inadvertent distributions that may increase disparities. The discovery of best practices and lessons learned in the financing and organization of dental care may begin by comparing US experiences with those of other countries.
Evidence for direct amelogenin–target cell interactions using dynamic force spectroscopy
Authors: Kirkham Jennifer , Andreev Igor , Robinson Colin , Brookes Steven J. , Shore Roger C. , Smith D. Alastair
Published: May 2006

Increasing evidence suggests that amelogenin, long held to be a structural protein of developing enamel matrix, may also have cell signaling functions. However, a mechanism for amelogenin cell signaling has yet to be described. The aim of the present study was to use dynamic chemical force spectroscopy to measure amelogenin interactions with possible target cells. Full‐length amelogenin (rM179) was covalently attached to silicon nitride AFM tips. Synthetic RGD peptides and unmodified AFM tips were used as controls. Amelogenin–RGD cell binding force measurements were carried out using human periodontal ligament fibroblasts (HPDF) from primary explants and a commercially available osteoblast‐like human sarcoma cell line as the targets. Results indicated a linear logarithmic dependence between loading rate and unbinding force for amelogenin–RGD target cells across the range of loading rates used. For RGD controls, binding events measured at 5.5 nN s−1 force loading rate resulted in a mean force of 60 pN. Values for amelogenin–fibroblast and amelogenin–osteoblast‐like cell unbinding forces, measured at similar loading rates, were 50 and 55 pN, respectively. These data suggest that amelogenin interacts with potential target cells with forces characteristic of specific ligand–receptor binding, suggesting a direct effect for amelogenin at target cell membranes.
Hypoplastic enamel defects and environmental stress in a homogeneous Romano–British population
Authors: Brook Alan H. , Smith Joyce M.
Published: May 2006

This study investigated hypoplastic enamel defects in a well‐defined sample of Romano–Britons from the 3rd to the 5th century AD and compared the findings with a modern British sample investigated by the same authors. All 178 excavated skulls with intact dentitions were examined for hypoplastic defects using the Federation Dentaire International (FDI) Developmental Defects of Enamel Index criteria. Histopathological and microradiographic sections were prepared of 5 teeth. Hypoplastic defects were found in the teeth of 37% of skulls, with 25% having 4 or more teeth affected. The teeth most frequently involved were canines. Of the defects, 75% were horizontal grooves, 12.7% were pitting, and 7.1% were areas of missing enamel. The location of defects was 82% buccal, 16.5% lingual, and 1.2% occlusal. The reproducibility of diagnosis was 84%. Microscopic and microradiographic investigations showed areas of hypomineralization of enamel and wide zones of interglobular dentine related to the hypoplastic grooves. There was higher frequency, different morphology, and greater severity of hypoplastic enamel defects compared with the modern British sample. The defects may be related to repeated environmental stresses between the ages of 2 and 6 yr. Identified environmental stresses in these Romano–Britons, including high lead ingestion, poor nutrition, and recurrent infections, may be important etiological factors for the enamel defects.
Porcine sheath proteins show periodontal ligament regeneration activity
Authors: Fukae Makoto , Kanazashi Mikimoto , Nagano Takatoshi , Tanabe Takako , Oida Shinichiro , Gomi Kazuhiro
Published: May 2006

The purpose of this study was to identify the periodontal regeneration factors of enamel protein extracts that induce cementum and bone regeneration in vivo. Cementum regeneration, one aspect of periodontal ligament regeneration, was examined using a buccal dehiscence model of dogs. Enamel matrix protein fractions were prepared from developing porcine incisors. Cementum‐regeneration activity was found to reside in a protein aggregate composed of amelogenins and sheath proteins extracted from newly formed secretory enamel. Cementum‐regeneration activity was not observed in protein fractions containing only amelogenin or its derivatives. The sheath proteins were purified to homogeneity and tested for alkaline phosphatase (ALP)‐inducing activity on human periodontal ligament (HPDL) cells. The induction of ALP was observed following application of the 17‐kDa sheath protein but not of the lower‐molecular‐weight sheath proteins. Although transforming growth factor‐β1 also shows ALP‐inducing activity, contamination with growth factors was excluded because synthetic peptides (based on the sheath protein's sequence) also showed ALP‐inducing activity. The 17‐kDa sheath protein showed both cytodifferentiation and cementum‐regeneration activity, but it is unclear whether its cementum‐regeneration activity is derived from its ALP‐inducing activity on HPDL cells.
Anisotropic properties of the enamel organic extracellular matrix
Authors: Do Espírito Santo Alexandre R. , Novaes Pedro D. , Line Sérgio R. P.
Published: May 2006

Enamel biosynthesis is initiated by the secretion, processing, and self‐assembly of a complex mixture of proteins. This supramolecular ensemble controls the nucleation of the crystalline mineral phase. The detection of anisotropic properties by polarizing microscopy has been extensively used to detect macromolecular organizations in ordinary histological sections. The aim of this work was to study the birefringence of enamel organic matrix during the development of rat molar and incisor teeth. Incisor and molar teeth of rats were fixed in 2% paraformaldehyde/0.5% glutaraldehyde in 0.2 M phosphate‐buffered saline (PBS), pH 7.2, and decalcified in 5% nitric acid/4% formaldehyde. After paraffin embedding, 5‐µm‐thick sections were obtained, treated with xylene, and hydrated. Form birefringence curves were obtained after measuring optical retardations in imbibing media, with different refractive indices. Our observations showed that enamel organic matrix of rat incisor and molar teeth is strongly birefringent, presenting an ordered supramolecular structure. The birefringence starts during the early secretion phase and disappears at the maturation phase. The analysis of enamel organic matrix birefringence may be used to detect the effects of genetic and environmental factors on the supramolecular orientation of enamel matrix and their effects on the structure of mature enamel.
The changes in T lymphocyte subsets following periodontal treatment in patients with chronic periodontitis
Authors: Erciyas Kamile , Orbak Recep , Kavrut Fahri , Demir Turgut , Kaya Hasan
Published: May 2006

Objective:  The aim of this study was to determine whether there was any change in T‐lymphocyte subsets in patients with chronic periodontitis after applying different periodontal treatment methods.

Patients and methods:  Twenty‐four patients with chronic periodontitis were included in the study. In every phase of the treatment (pretreatment, initial treatment, curettage and flap operations) the biopsy samples were taken from the gingival tissues at sites of chronic periodontitis. Then CD4+ and CD8+ lymphocyte and CD4+/CD8+ ratio values were determined using flow cytometry in the biopsy samples. At the same time, gingival pocket depth, Löe–Silness gingival index, and Silness–Löe plaque index scores were recorded to assess the periodontal status in patients. To determine the correlation between the clinical measurements and the laboratory results obtained before the treatment, after initial treatment, after curettage and after flap operations, we conducted an analysis using a paired t‐test.

Results:  Flow cytometry findings in the patients with chronic periodontitis showed that CD4+ and CD8+ lymphocyte values before treatment were under the normal value and the CD4+/CD8+ ratio was within the normal distribution interval. The CD4+/CD8+ ratio decreased postcurettage and postflap operation. This decrease was statistically significant (p < 0.001). The CD4+ and CD8+ lymphocyte values were increased postcurettage and postflap operation. This increase was also statistically significant (p < 0.001).

Conclusions:  These findings suggest that local immune response was poor in the patients with chronic periodontitis. CD4+ and CD8+ T‐lymphocytes could play a significant role in chronic periodontitis pathobiology.
11β‐Hydroxysteroid Dehydrogenase Activity in Pregnancies Complicated by Hydatidiform Mole
Authors: Muneyyrici‐Delale Ozgul , Nacharaju Vijaya L. , Sidell Jon , Neil Gregory , Karacan Meric , Camilien Louis , Temkin Sarah , Abulafia Ovadia
Published: May 2006

Problem

11β‐Hydroxysteroid dehydrogenase (11β‐HSD) plays an important role in regulating active glucocorticoid reaching the fetus. In normal pregnancy, placental 11β‐HSD functions primarily in oxidative direction. Placental tissue of patients with pregnancies complicated by pre‐eclampsia exhibit significantly lower type 1 and 2 11β‐HSD activities and significantly high cortisol level in cord blood suggesting fetal exposure to higher level of active glucocorticoids. The activity of 11β‐HSD in gestational trophoblastic disease has not been determined. The objective of this study was to assess 11β‐HSD activity in tissue from normal second trimester and pregnancies complicated by hydatidiform mole.

Method of study

Normal placental tissues were obtained from patients undergoing termination of pregnancy, and from patients undergoing uterine evacuation for hydatidiform mole. Both nicotinamide adenine dinucleotide (NAD)‐ and nicotinamide adenine dinucleotide phosphate (NADP)‐dependent activities were assayed in central villous tissue. Comparison of groups was performed using Student's t‐test. A P‐value of 0.05 was considered significant. Data are presented as mean ± S.D.

Results

Tissue obtained from five patients with pathology‐proven hydatidiform mole demonstrated significantly lower 11β‐HSD activities compared with placental tissue obtained from normal pregnancies. The mean NAD‐dependent 11β‐HSD activity in normal placentas was 386 ± 109 pmol/min/g placenta and in hydatidiform mole was 74 ± 54 pmol/min/g placenta (P < 0.01). The mean NADP‐dependent 11β‐HSD activity in normal placentas was 370 ± 120 pmol/min/g placenta and in trophoblastic disease was 68 ± 69 pmol/min/g placenta (P < 0.01).

Conclusion

Our data indicate significant impairment in the ability of hydatidiform mole tissue to inactivate glucocorticoids.
1141174724 Complement activation induces dysregulation of angiogenic factors and causes fetal loss
Authors: Girardi G , Yarilin D , Thurman JM , Holers VM , Salmon JE
Published: May 2006

Complement is an important effector in pregnancy loss in the antiphospholipid syndrome. We now test the hypothesis that complement activation is a necessary intermediary event in the pathogenesis of recurrent spontaneous miscarriage in DBA/2‐mated female CBA/J mice (CBAxDBA), a well‐studied model of autoantibody‐independent pregnancy failure. Blockade of C3 activation with Crry‐Ig completely rescued pregnancies in CBAxDBA mice (Crry‐Ig vs untreated 8.5 ± 6.3% fetal resorptions vs 28.0 ± 7.2%, P < 0.01). Inhibition of C5 cleavage with anti‐C5 mAb and blockade of C5a receptors with a peptide antagonist also prevented pregnancy loss (8.6 ± 4.4% and 8.0 ± 5.9% resorptions, respectively, P < 0.01 versus control). Inhibition of the alternative pathway resulted in pregnancy outcomes similar to controls (8.4 ± 6.6% versus 9.2 ± 3.2% resorptions). In CBAxDBA matings, we observed elevated plasma levels of soluble VEGF receptor‐1 (sVEGFR‐1; a potent anti‐angiogenic molecule), increased placental inflammatory infiltrates and defective development of placenta. Our complement inhibitory strategies blocked the increase in sVEGFR‐1, prevented functional deficiency of VEGF and rescued pregnancies. We confirmed the importance of complement as a proximal effector in in vitro studies; monocytes stimulated with C5a released sVEGFR‐1 which sequesters VEGF required for normal placental development. Our data indicate that complement activation leads to recruitment of inflammatory cells and production of inhibitors of angiogenesis (sVEGFR‐1) which cause placental dysfunction and fetal injury. These studies identify key innate immune effectors that mediate poor pregnancy outcomes and provide novel and important targets for prevention of recurrent pregnancy loss in patients.
1141222744 Analysis of the relationship between ureaplasmal infection and premature delivery
Authors: Harada K , Tanaka H , Tsuji Y , Koyama K
Published: May 2006

Aim:  Ureaplasma has recently been reported to be a pathogenic organism for sexually transmitted diseases and also for chorioamnionitis, premature delivery and neonatal pneumonia. In this study, we examined whether the ureaplasma infection is related to premature delivery.

Methods:  Vaginal swabs were obtained from 85 pregnant women (including 63 of normal delivery and 23 of premature delivery), and cultured in Ureaplasma culture medium. The swabs were also analyzed for bacteria flora using the conventional culture method. DNA was extracted from ureaplasma colonies grown to determine the biotype by PCR direct sequence method.

Results:  Ureaplasma infection was found in 51.6 and 52.6% of full‐term and preterm delivery women, respectively indicating that ureaplasma infection had no relation to premature delivery. The biotype of ureaplasma also had no relevance to preterm delivery. However, the interval between hospitalization due to threatened premature delivery and actual delivery was 8.4 days for ureaplasma‐infected patients as compared to 18 days for non‐infected patients. This result suggests that ureaplasma infection accelerates the process of premature delivery or shortens time to premature delivery.

Conclusion:  Our study found no association between ureaplasma infection or biotype and premature delivery. However, we found that ureaplasma‐infected patients were not as readily treatable for threatened preterm delivery as non‐infected patients.
1141404284 How should data on murine spontaneous abortions be expressed and analysed?
Authors: Clark DA , Chaouat G
Published: May 2006

Problem:  Spontaneous abortions (resorptions) in the CBAxDBA/2 are normally reported as number or resorptions/total number of implantations pooling >5 mice (R/T). The significance of differences between groups is 2 or Fisher's Exact test determined using non‐parametric methods (e.g. based on a priori predictions). Recently, it has been suggested that medians with box‐plots replace the accepted standard. This has led to reported rates of abortion of zero, where a median (that divides a population into the 50% of mice > the median and the 50% < the median) cannot logically exist. This method gives equal value to a mouse with 0/2 = 0% abortions and 0/10 = 0% abortions, and deprives readers of key data required to verify P values. The fact that there is an irreducible minimum loss due to chromosomally abnormal embryos (2–5%) is also ignored.

Methods:  Raw data on 177 individual CBAxDBA/2 matings was analysed by median, mean, and geometric mean, along with R/T from 6 independent experiments with 5–10 mice per group.

Result:  Individual abortion rates showed a non‐Gaussian distribution, but the mean and median differed by <0.5%. R/T data from the 6 independent experiments were normally distributed. Only mean and geometric mean enable between‐group P value calculation.

Conclusion:  Although it is possible to compare individual mice (and even individual implantation sites), as the relevant question is the significance of differenced between treatments in groups of mice and reproducibility, the established classical method should continue to be used.
1141420984 Placental exosome suppression of T cell activation and differential target of T cell subsets
Authors: Taylor DD , Gercel‐Taylor C
Published: May 2006

Problem:  One immunoregulatory pathway that has received little attention is placental exosome release. In normal pregnancy, as factors linked with early immunomodulation decline, placental exosomes become key in modulating T‐cell activation, maintaining the absence of effector T‐cells by enhancing T cell apoptosis and loss of CD3‐z.

Method of Study:  Placental exosomes were isolated from the maternal peripheral circulation by a chromatographic/MACS procedure developed to specifically purify exosomes of placental origin. Exosomal FasL was identified by immunoelectron microscopy (IEM) and quantified by ELISA. Exosomal suppression of T cell signaling molecules and induction of apoptosis was determined by flow cytometry and DNA fragmentation, respectively. The role of FasL in these events was defined by use of FasL blocking antibody. The differential effect of exosomes on CD3‐z on T subsets was analyzed by western immunoblot (WB).

Results:  When T cells were co‐incubated with placental exosomes, CD3‐z was down‐regulated, with placental exosomes treated cells expressing 18,900 ± 7,000 MESF units of zeta, while control fraction‐treated cells expressed 49,000 ± 4,800 MESF units of zeta (P < 0.001). This down‐regulation of CD3‐z was partially reversed by pre‐incubating T cells with ZB4 antibody, suggesting a role for FasL. IEM revealed FasL‐antibody complexes located on the exterior of placental exosomes; however, only 20/27 preparations were FasL+. When placental exosomes were added to T cells, the level of CD3‐z expression on CD8+ cells was 7.1%, (8.7% vs 59.7%) inhibited 1.43‐fold more than in CD4+ cells (85.5 P < 0.01). On CD4+CD25+ cells, CD3‐z was not significantly inhibited. (P < 0.05).

Conclusions:  While all term placental exosome preparations tested induced apoptosis, exosomes obtained from 7/27 patients were negative for FasL but were able to induce DNA degradation. These results indicate that, while exosomal FasL is apoptogenic, additional exosome components are capable of inducing apoptosis, but these factors exhibit differential effect on T subsets.
1141478081 Cleavage of integrin by calpain in patients with recurrent miscarriage
Authors: Nozawa K , Ozaki Y , Guto S , Nakanishi T , Aoyama K , Ogasawara MS
Published: May 2006

Problem:  In our previous study, we have been reported that calpain, a calcium‐dependent cysteine protease, activated by increasing intracellular calcium‐ion concentration in endometrial cell, cause endometrial dysfunction for implantation. In this study, we investigated the existence and contribution of calpains, their endogenous inhibitor calpastatin, and their substrate such as integrin β3 and α‐fodrin in deciduas of patients with recurrent miscarriage.

Method of Study:  Deciduas were surgically collected from 31 patients with recurrent miscarriage and 23 healthy women with informed consent. Immunohistochemistry, SDS‐PAGE and western blot analysis were performed using antibodies against calpain, calpastatin, integrin β3 and α‐fodrin.

Results:  Staining of μ‐calpain, m‐calpain, capastatin, integrin β3 and α‐fodrin were observed in the cytoplasm of stromal and epithelial cells in deciduas using immunohistochemistry. No significant differences were observed in staining patterns. Western blot analysis shows no significant differences in m‐calpain, calpastatin and α‐fodrin, while μ‐calpain was significantly higher and integrin β3 was lower in subject.

Conclusions:  The result provided that cleavage of integrin β3 by μ‐calpain may cause adverse effect in the mechanism of early pregnancy.
1141584386 Cell type specific regulation of human placenta growth factor
Authors: Chang M , Groesch KA , Mukherjea D , Torry DS
Published: May 2006

Background:  Maternal serum levels of PlGF are significantly lower in preeclamptic patients than in normal pregnant women. PlGF mRNA expression is cell type specific with high levels in trophoblast but comparatively low levels in most nontrophoblast. Despite two consensus hypoxia response elements (HREs), PlGF expression is down regulated by hypoxia in trophoblast, but increased in other cell types. These observations suggest unique regulatory mechanisms control PlGF expression. We sought to characterize PlGF promoter regions which function to regulate transcription rates in different cell types and under hypoxia.

Methods:  Regions of human PlGF gene (−1521/+34), (−828/+34), (−698/+34) were cloned into a reporter vector and (−844/−677) was cloned into a minimal TK promoter containing expression vectors. Trophoblast (JEG3 and JAR), and nontrophoblast (HeLa and hEK‐293) were transiently transfected to determine functional responsiveness of the regions. A PlGF gene region containing two HREs was cloned upstream of a TK containing vector to determine hypoxia (1% O2) responsiveness.

Results:  PlGF (−1521/+34), (−828/+34) regions showed high promoter activity in trophoblast cells, but little activity in nontrophoblast cells. PlGF (−844/−677) cloned downstream of the TK reporter, augmented promoter activity in trophoblast but not nontrophoblast cells. When cloned upstream to the TK promoter, this region significantly decreased activity in nontrophoblast cells. Surprisingly, the PlGF region containing HREs produced little increase in minimal promoter activity during hypoxia in any of the cells.

Conclusions:  PlGF transcription is cell type specific and a region of PlGF (−828/−698) may act as an enhancer in trophoblast yet mediates repressor activity in nontrophoblast. The putative HREs in PlGF 5’UTR do not seem to increase PlGF transcription under hypoxia suggesting that they are not essential for governing PlGF expression. Further understanding of transcriptional regulation of PlGF in trophoblast may facilitate approaches to increase expression during preeclampsia.
1141612823 Effect of recombinant ovine intereferon tau (IFN) on the ovine Mx1 promoter/enhancer region
Authors: Assiri AM , Carnahan KG , Ott TL
Published: May 2006

Ovine Mx1 (oMx1) is expressed in the uterus during the estrous cycle and is strongly up‐regulated during early pregnancy in the uterus and peripheral blood leukocytes. Mx proteins are GTPases which are important elements in innate immunity. Our results showed that steroids are required for oMx1 protein induction by IFN in the uterus. To addresses the role of IFN in regulating oMx1 expression, a 2.1 kb fragment containing 1.7 kb of the promoter/enhancer, exon1 and partial intron A was cloned. Serial deletions were prepared along with a clone that contained the 2 promoter‐ISREs (‐101 & −145) but not the intronic‐ISRE (+224). An ovine uterine cell line was transfected with reporter plasmids driven by the oMx1 promoter deletion constructs. The full‐length promoter was induced by IFN in a dose‐ and time‐dependent manner. Treatment with 10,000 AVU/mL IFN increased luciferase activity 5‐ and 10‐fold at 3 and 12 hr, respectively. Promoter deletions showed the 2 proximal ISRE (−101 and −145), but not an intronic ISRE (+244), were required for maximal response. Deletion of a distal region (−920 to −715) resulted in decreased luciferase activity (~4‐fold). However, subsequent deletion of the −715 to −437 region restored maximal promoter response (~10‐fold). Results suggest that regions −920 to −715 and −715 to −437 have positive and negative regulatory element binding sites, respectively. The importance of the 2 proximal ISRE sites for oMx1 promoter activation is consistent with results for the human MxA promoter. An intronic ISRE is present in the human MxA gene, however, this site may not be required for oMx1 promoter activation by IFN. Identifying positive and negative regulatory regions in oMx1 promoter may help elucidate the unique regulation of Mx1 during early pregnancy.
1139687336 Which thrombophilic gene mutations are risk factors for recurrent pregnancy loss?
Authors: Goodman CS , Coulam CB , Jeyendran RS , Fishel LA , Roussev RG
Published: May 2006

Objective:  We have previously reported that when 10 thrombophilic genes were investigated, more than three gene mutations among the 10 genes were observed significantly more frequently among women experiencing recurrent pregnancy loss than fertile control women. The question then arose as to which of the 10 mutations were necessary to identify the risk of recurrent pregnancy loss. The present study was undertaken to answer this question.

Materials and Methods:  550 women with a history of recurrent pregnancy loss had buccal swabs taken for DNA analyses of 10 gene mutations (Factor V G1691A, Factor V H1299R (R2), Factor V Y1702C, Factor II Prothrombin G20210A, Factor XIII V34L, beta‐Fibrinogen ‐455G>A, PAI‐1 4G/5G, HPA1 a/b (L33P), MTHFR C677T, MTHFR A1298C). The frequency of these mutations were compared with controls published in the literature.

Results:  When examined individually, three out of the ten mutations studied correlated significantly with recurrent pregnancy loss compared with controls, including PAI‐1 4G/5G (P = 0.0037), Factor XIII V34L (P < 0.0001), and homozygous MTHFR C667T (P = 0.04). The frequency of the Factor V Y1702C mutation was extremely low in patients and controls; thus, this gene was removed from further calculations. The remaining six mutated genes, when analyzed cumulatively, also corresponded with recurrent pregnancy loss with total number of mutations significantly increased among patients compared with controls (P < 0.0001).

Conclusion:  A panel of thrombogenic gene mutations consisting of Factor V G1691A, Factor V H1299R (R2), Factor II Prothrombin G20210A, Factor XIII V34L, beta‐Fibrinogen‐455G>A, PAI‐1 4G/5G, HPA1 a/b (L33P), MTHFR C677T, and MTHFR A1298C can identify individuals at risk for recurrent pregnancy loss.
1140918593 Altered expression of cell surface CD200 tolerance‐signaling molecule on human PBL stored at 4°C or 37°C correlates with reduced or increased efficacy in controlled trials of treatment of recurrent miscarriages
Authors: Clark DA , Banwatt D
Published: May 2006

Problem:  The CD200 molecule is required for prevention of abortions in mice by allogeneic lymphomyeloid cells bearing paternal antigen, and storage of at 4°C overnight causes loss of cell‐surface CD200 and loss of efficacy. Human PBL stored at 4°C overnight also lose CD200 and were ineffective in a randomized controlled trial RCT, odds ratio for live birth with stored cells = 0.55 (95% CI 0.27–1.14) versus 1.68 (95% CI 1.04–2.70) with freshly isolated PBL. A recent published RCT utilizing paternal PBL stored at 37°C overnight reported a dramatic reduction in abortion rate, odds ratio for live birth with treatment = 10.2 (95% CI 3.97–26.08). Does storage at 37°C increase expression of cell‐surface CD200?

Methods:  Hypaque‐ficoll‐purified human PBL were analysed by flow cytometry using PE‐anti‐huCD200 before and after storage in PBS for 18 hr at 4°C, 22°C, or 37°C.

Results:  Purified PBL stored at 4°C showed reduced expression of CD200, whereas at 37°C, CD200 expression was dramatically increased.

Conclusions:  The protective effect of paternal PBL against recurrent spontaneous abortion may be altered by storage conditions, and level of expression of cell‐surface CD200 appears to be a key correlate of efficacy.
Advances in Rapid
Distortion Theory: From Rotating Shear Flows to the Baroclinic
Instability
Authors: Salhi Aziz , Cambon Claude
Published: May 2006

The essentials of rapid distortion theory (RDT) are briefly recalled for homogeneous turbulence subjected to rotational mean flows, including its linkage to stability analysis. The latter “linkage” is of particular importance from our viewpoint, since it also attracted the attention of Charles Speziale, resulting in at least two papers [Speziale, C. G., Abid, R., and Blaisdell, G. A., 1996, “On the Consistency of Reynolds Stress Turbulence Closures With Hydrodynamic Stability Theory,” Phys. Fluids, 8, pp. 781–788 and Salhi, A., Cambon, C., and Speziale, C. G., 1997, “Linear Stability Analysis of Plane Quadratic Flows in a Rotating Frame,” Phys. Fluids, 9(8), pp. 2300–2309] with particular emphasis on rotating flows. New analytical solutions and related RDT results are presented for shear flows including buoyancy forces, with system rotation or mean density stratification. Finally, combining shear, rotation and stratification, RDT is shown to be pertinent to revisiting the baroclinic instability. This instability results from the tilting of mean isopycnal surfaces under combined effects of vertical shear and system rotation, in a vertically (stably) stratified medium rotating around the vertical direction. In addition, the challenge of reproducing RDT dynamics in single-point closure models is briefly discussed, from the viewpoint of structure-based modeling [Cambon C., Jacquin, L., and Lubrano, J.-L., 1992, “Towards a New Reynolds Stress Model for Rotating Turbulent Flows,” Phys. Fluids A, 4, pp. 812–824 and Kassinos, S. C., Reynolds, W. C., and Rogers, M. M., 2000, “One-Point Turbulence Structure Tensors,” J. Fluid Mech., 428, pp. 213–248.
Finite Element Investigation of Bauschinger Effect in High-Strength A723 Pressure Vessel Steel
Authors: Troiano Edward , Underwood John H. , Parker Anthony P.
Published: May 2006

The Bauschinger effect has been evaluated in high-strength pressure vessels. A simple initial test suggested that a biaxial Bauschinger effect was present and that it was different from previously published uniaxial Bauschinger results. The difference was believed to be significant, so further investigation was undertaken. Several full-size A723 steel gun sections were heavily overstrained and subjected to slit tests in order to measure opening angles and displacements. These geometries were then modeled with finite element (FE) analysis using both ideal autofrettage stresses and Bauschinger modified stresses, which were based on previously published uniaxial Bauschinger test results. Because techniques available for predicting reverse yielding for overstrained pressure vessels were limited, a simple methodology for predicting the yield surface upon reverse yielding from a series of uniaxial Bauschinger test data was developed and is presented. This methodology, when used in the FE predictions, compares favorably with analytical predictions made previously. Comparisons of slit-opening results measured from pressure vessel sections with FE calculations using uniaxial Bauschinger data are made. The opening displacements comparison between the uniaxial predictions and those measured from the heavily overstrained sections with biaxial stresses are so subtle (<1mm) that the tests appear to be inconclusive.
Stress Intensity Factors for Internal Straight and Curved-Fronted Cracks in Thick Cylinders
Authors: Parker Anthony P. , Tan Choon-Lai
Published: May 2006

Fatigue and leak-before-break calculations for a pressure vessel require knowledge of the stress intensity factor at the deepest point of a straight- or curved-fronted (semi-elliptical) surface crack emanating from the bore of an internally pressurized, autofrettaged thick cylinder. A limited number of available solutions is curve fitted. The concept of a tube equivalent plate (TEP), which exhibits crack-constraint characteristics matching those of a thick cylinder, is developed, and the resulting equations are curve fitted. Ratios of the TEP stress intensity factor results are then used to interpolate between certain existing solutions. This provides wide-ranging solutions covering radius ratios from 1.8 to 3.0, autofrettage overstrain from 0 to 100% and crack shapes from straight fronted to semi-circular. The calculation procedure is described using worked examples.
Assembly of Compound Tubes Under Hydraulic Pressure
Authors: Andrews Tony D.
Published: May 2006

This paper describes a method for inserting a tapered liner into a sleeve while the latter is expanded by hydraulic pressure. The technique avoids many of the limitations associated with traditional shrink fit techniques and autofrettage. The sleeve and liner are manufactured with internal and external tapers, respectively, to give the appropriate interference for the finished compound tube. The liner is mounted on a rod and positioned loosely inside the sleeve. The ends of the sleeve are sealed with plugs, which allow the rod to protrude through each end and which also have hydraulic oil inlets. Once the assembly has been pressurized, the rod is pushed into the vessel to move the liner further into the sleeve generating an interference once the pressure in the sleeve is removed. Insertion of a relatively thin liner can generate high residual compressive stresses at the bore, similar to autofrettage but with a shallower gradient away from the bore. Because the liner is not subjected to plastic strain during manufacture, there is no reduction in compressive strength due to the Bauschinger effect and the maximum compressive stress obtainable is greater than that from traditional autofrettage routes. Such high stresses lead to excess tension in the sleeve, which must be reduced by autofrettaging the sleeve prior to assembly of the compound tube. Such a configuration is suitable for inserting a part-length liner at the chamber for strength and/or wear resistance and tensile stresses can be eliminated to prevent failure of brittle materials, such as ceramics.
Investigation of Microbubble Boundary Layer Using Particle Tracking Velocimetry
Authors: Ortiz-Villafuerte Javier , Hassan Yassin A
Published: May 2006

Particle tracking velocimetry has been used to measure the velocity fields of both continuous phase and dispersed microbubble phase, in a turbulent boundary layer, of a channel flow. Hydrogen and oxygen microbubbles were generated by electrolysis. The average size of the microbubbles was 15μm in radius. Drag reductions up to 40% were obtained, when the accumulation of microbubbles took place in a critical zone within the buffer layer. It is confirmed that a combination of concentration and distribution of microbubbles in the boundary layer can achieve high drag reduction values. Microbubble distribution across the boundary layer and their influence on the profile of the components of the liquid mean velocity vector are presented. The spanwise component of the mean vorticity field was inferred from the measured velocity fields. A decrease in the magnitude of the vorticity is found, leading to an increase of the viscous sublayer thickness. This behavior is similar to the observation of drag reduction by polymer and surfactant injection into liquid flows. The results obtained indicate that drag reduction by microbubble injection is not a simple consequence of density effects, but is an active and dynamic interaction between the turbulence structure in the buffer zone and the distribution of the microbubbles.
Shape Recovery of a Levitated Aspherical Droplet From 2D Image Information
Authors: Bakhtiyarov Sayavur , Dupac Mihai , Overfelt Ruel A.
Published: May 2006

This paper presents an image processing technique in order to predict the shape of a levitated aspherical droplet. The technique is of great importance to containerless materials processing. A majority of the electromagnetic levitation techniques utilizes two cameras at right angles to observe both transversal and frontal views. This allows obtaining two images of the droplet at instant time. In many cases, the portion of the frontal image is missing due to the heating coil. The newly developed technique allows restoration of the missing portion of the image information. The through image can be reconstructed by combining the recovered shapes. A special computer program is generated to simulate a normalized volume of the droplet.
Laboratory Heat Transfer Experiments on a 155mm Compound Gun Tube With Full Length Integral Mid-Wall Cooling Channels
Authors: Bass Mark , de Swardt Rolf R.
Published: May 2006

A 155 mm compound gun barrel with full-length integral mid-wall cooling channels was manufactured and connected to a purpose built heat exchanger. Laboratory testing of this system was carried out using electrical heating jackets applied to the outer surface of the barrel and an internal electrical chamber heater to heat the barrel as uniformly as possible along its length. A series of tests were then carried out consisting of first heating the barrel to a uniform temperature of approximately 80°C followed by switching on the heat exchanger and monitoring the rate at which the barrel cooled. The purpose of these tests was to determine the optimum cooling characteristics of the system by studying the effect of different coolant flow rates combined with one or both radiators functioning and also the effect of using different cooling fluid solutions. Having derived the optimum flow rate and coolant solution combination a further cooling test was carried out with the heat exchanger configured to these optimum values and with the barrel heaters operating at maximum capacity. Finally a natural cooling test was undertaken where the barrel was uniformly heated to 160°C, the heating jackets removed and the barrel left to cool overnight. The results from these tests prove that natural cooling is dramatically slower than forced mid-wall cooling.
A Composite Rigid Body Algorithm for Modeling and Simulation of an Underwater Vehicle Equipped With Manipulator Arms
Authors: Hosseini Mohammad Khalaj Amir , Omidi Omid , Meghdari Ali , Vossoughi Gholamreza
Published: May 2006

In this paper, modeling and simulation of an underwater vehicle equipped with manipulator arms, using a composite rigid body algorithm, will be discussed. Because of the increasing need for unmanned underwater vehicles (UUVs) in oil and gas projects in the Persian Gulf, for doing operations such as inspection of offshore jackets, subsea pipelines, and submarine cables, and also pre-installation survey and post-laid survey of submarine pipelines and cables, design and construction of “SROV” was developed in Sharif University of Technology, and at the design stage behavior of the underwater vehicles was studied. In this paper, an efficient dynamic simulation algorithm is developed for an UUV equipped with m manipulators so that each of them has N degrees of freedom. In addition to the effects of the mobile base, the various hydrodynamic forces exerted on these systems in an underwater environment are also incorporated into the simulation. The effects modeled in this work are added mass, viscous drag, fluid acceleration, and buoyancy forces. For drag forces, the emphasis here is on the modeling of the pressure drag. Recent advances in underwater position and velocity sensing enable real-time centimeter-precision position measurements of underwater vehicles. With these advances in position sensing, our ability to precisely control the hovering and low-speed trajectory of an underwater vehicle is limited principally by our understanding of the vehicle’s dynamics and the dynamics of the bladed thrusters commonly used to actuate dynamically positioned marine vehicles. So the dynamics of thrusters are developed and an appropriate mapping matrix dependent on the position and orientation of the thrusters on the vehicle is used to calculate resultant forces and moments of the thrusters on the center of gravity of the vehicle. It should be noted that hull-propeller and propeller-propeller interactions are considered in the modeling too. Finally, the results of the simulations, for an underwater vehicle equipped with 1 two degrees of freedom manipulator, are presented and discussed in detail.
Empirical cupping correction: A first‐order raw data precorrection for cone‐beam computed tomography
Authors: Kachelrieß Marc , Sourbelle Katia , Kalender Willi A.
Published: May 2006

We propose an empirical cupping correction (ECC) algorithm to correct for CT cupping artifacts that are induced by nonlinearities in the projection data. The method is raw data based, empirical, and requires neither knowledge of the x‐ray spectrum nor of the attenuation coefficients. It aims at linearizing the attenuation data using a precorrection function of polynomial form. The coefficients of the polynomial are determined once using a calibration scan of a homogeneous phantom. Computing the coefficients is done in image domain by fitting a series of basis images to a template image. The template image is obtained directly from the uncorrected phantom image and no assumptions on the phantom size or of its positioning are made. Raw data are precorrected by passing them through the once‐determined polynomial. As an example we demonstrate how ECC can be used to perform water precorrection for an in vivo micro‐CT scanner (TomoScope 30 s, VAMP GmbH, Erlangen, Germany). For this particular case, practical considerations regarding the definition of the template image are given. ECC strives to remove the cupping artifacts and to obtain well‐calibrated CT values. Although ECC is a first‐order correction and cannot compete with iterative higher‐order beam hardening or scatter correction algorithms, our in vivo mouse images show a significant reduction of bone‐induced artifacts as well. A combination of ECC with analytical techniques yielding a hybrid cupping correction method is possible and allows for channel‐dependent correction functions.
Effect of electrode configuration on psychophysical forward masking in cochlear implant listeners
Authors: Kwon Bom Jun , van den Honert Chris
Published: May 2006

Bipolar stimulation has been thought to be more beneficial than monopolar stimulation for speech coding in cochlear implants, on the basis of its more restricted current flow. The present study examined whether bipolar stimulation would indeed lead to reduced channel interaction in a behavioral forward masking experiment tested in four Nucleus® 24 users. The masker was fixed on one channel and three masker levels that were balanced for loudness between the configurations were chosen. As expected, masking was maximal when the masker and probe channels were spatially close and decreased as they were separated. However, overall masking patterns did not consistently demonstrate sharper tuning with bipolar stimulation than monopolar. This implies that the spatial extent of a bipolar current field is not consistently narrower than that of an equally loud monopolar stimulus; therefore, it should not be assumed that bipolar stimulation leads to reduced channel interaction. Notably, bipolar masking patterns appeared to display more variations across channels, possibly influenced more by anatomical and neural irregularities near electrode contacts than monopolar masking patterns. The present psychophysical results provide a theoretical basis regarding the widespread use (and success) of monopolar configurations by implant users.
Middle ear ossicles motion at hearing thresholds with air conduction and bone conduction stimulation
Authors: Stenfelt Stefan
Published: May 2006

Hearing threshold data with bone conduction and air conduction stimulation are combined with physiological and mechanical measurements of the middle ear ossicles vibration to compute the vibration level of the ossicles at threshold stimulation. By comparing the displacements of the stapes footplate with the two stimulation modalities and assuming the vibration of the stapes footplate to be the input to the cochlea when stimulation is by air conduction, the importance of middle ear ossicles inertia with bone conduction stimulation is evaluated. Given the limitations of the analysis, the results indicate that the inertia of the middle ear is not an important contribution to the perception of BC sound for frequencies below 1.5kHz; it seems to contribute to perception of bone conducted sound between the frequencies 1.5 and 3.5kHz. At frequencies above 4kHz, the analysis failed since the input to the cochlea is probably not through the oval window with bone conduction stimulation. Comparison of basilar membrane vibration data verified the calculations for frequencies between 0.8 and 3.5kHz. It was also found that the fluid flow at the round window, rather than at the oval window, reflects the stimulation of the basilar membrane with bone conduction stimulation.
Nonconstant quality of auditory filters in the porpoises, Phocoena phocoena and Neophocaena phocaenoides (Cetacea, Phocoenidae)
Authors: Popov Vladimir V. , Supin Alexander Ya. , Wang Ding , Wang Kexiong
Published: May 2006

Simultaneous tone-tone masking in conjunction with the envelope-following response (EFR) recording was used to obtain tuning curves in porpoises Phocoena phocoena and Neophocaena phocaenoides asiaeorientalis. The EFR was evoked by amplitude-modulated probes with a modulation rate of 1000Hz and carrier frequencies from 22.5 to 140kHz. Equivalent rectangular quality QERB of the obtained tuning curves varied from 8.3–8.6 at lower (22.5–32kHz) probe frequencies to 44.8–47.4 at high (128–140kHz) frequencies. The QERB dependence on probe frequency could be approximated by regression lines with a slope of 0.83 to 0.86 in log-log scale, which corresponded to almost frequency-proportional quality and almost constant bandwidth of 3–4kHz. Thus, the frequency representation in the porpoise auditory system is much closer to a constant-bandwidth rather that to a constant-quality manner.