bluuebunny/crossref_metadata_2025 huggingface dataset:
Altered expression of β‐catenin/E‐cadherin in meningiomas
Authors: Brunner E C , Romeike B F M , Jung M , Comtesse N , Meese E
Published: June 2006

Aims : Meningiomas are generally slow‐growing benign tumours representing approximately 20% of all primary intracranial tumours. The hallmark of tumorigenesis of meningiomas is the loss of chromosome 22, including loss of heterozygosity of the neurofibromatosis type 2 (NF2) gene. The NF2 encoded protein merlin appears to function as a tumour suppressor gene by controlling cadherin‐mediated cell–cell adhesion. The E‐cadherin cell adhesion system includes β‐catenin that indirectly connects cadherin to actin filaments. The aim of this study was to analyse the expression and the subcellular location of E‐cadherin and β‐catenin in human meningiomas, including meningiomas of different histomorphological subtypes and different World Health Organization (WHO) grades.

Methods and results : Immunohistochemical analysis revealed lack of E‐cadherin expression at the cell membrane in 34% of meningiomas independent of their WHO grade. Loss of membranous β‐catenin occurred in 79% of meningiomas. An intense perinuclear granular immunoreactivity of β‐catenin without nuclear location was detected in the majority of meningiomas. Both immunofluorescence and Western blot analysis of fractionated meningioma cells located β‐catenin mostly on the Golgi apparatus and ER/Golgi intermediate compartment (ERGIC). Cytogenetic analysis of meningiomas showed no correlation between NF2 loss and the loss of the proper location of β‐catenin.

Conclusions : The lack of membranous β‐catenin and/or membranous E‐cadherin in meningiomas may indicate an altered interaction between meningioma cells independent of loss of NF2 and independent of the tumour grade.
Vascular endothelial growth factor C—a potent risk factor in childhood acute lymphoblastic leukaemia: an immunocytochemical approach
Authors: Nowicki M , Ostalska‐Nowicka D , Kaczmarek E , Miskowiak B , Witt M
Published: June 2006

Aims : To investigate the immunocytochemical expression of vascular endothelial growth factor C (VEGF‐C) and its receptors (VEGFR‐2 and VEGFR‐3) in childhood acute lymphoblastic leukaemia (ALL) blasts and to determine the possible role of this complex in the pathogenesis and prognosis of ALL.

Methods and results : Bone marrow samples were taken from 120 children diagnosed with ALL. An indirect immunocytochemical procedure was performed with the use of monoclonal mouse anti‐human antibodies against VEGF‐C, VEGFR‐2 and VEGFR‐3 (diluted 1 : 100). The immunocytochemical expression of VEGF‐C was confirmed exclusively in the cytoplasm of ALL lymphoblasts (the mean percentage was 36.4 ± 7.2). It was absent from the cytoplasm of normal haematopoietic cells in the control group. No VEGFR‐2 or VEGFR‐3 expression was detected in the children of either the study or control groups. The risk of induction failure or leukaemic relapse was found to be significant in all VEGF‐C+ patients (P < 0.0001 and P < 0.02, respectively; Fisher's exact test).

Conclusions : The absence of VEGF‐C in blast cells predicts long‐lasting remission in all leukaemic children. Our findings also suggest that leukaemic cell invasion, following VEGF‐C‐driven lymphangiogenesis, could be related to a mediating role of this peptide produced by blast cells themselves.
Heparanase expression in nasopharyngeal carcinoma inversely correlates with patient survival
Authors: Bar‐Sela G , Kaplan‐Cohen V , Ilan N , Vlodavsky I , Ben‐Izhak O
Published: June 2006

Aim : To determine the expression and prognostic significance of heparanase in nasopharyngeal carcinoma (NPC).

Methods : Immunohistochemistry was performed on formalin‐fixed paraffin‐embedded sections of 46 patients with NPC. Clinical and immunohistochemical data were correlated with gender, age, histological type, Epstein–Barr virus (EBV) status, stage and survival.

Results : Heparanase immunoreactivity was found in 35% (16/46) of specimens. The cumulative survival of patients diagnosed as heparanase negative (n = 30) at 10 years was 70%. In contrast, the cumulative survival of patients diagnosed as heparanase positive (n = 16) at 10 years was 25%, differences that are highly statistically significant (P = 0.03). No significant correlations were found between heparanase immunoreactivity and gender, age, EBV status, tumour histology or tumour stage.

Conclusion : Heparanase expression is inversely correlated with survival of NPC patients, clearly indicating that heparanase is a reliable prognostic factor for this malignancy, and further supports the notion that heparanase is a valid target for the development of anti‐cancer drugs.
Stress analysis of implant‐supported partial prostheses in anisotropic mandibular bone: in‐line versus offset placements of implants
Authors: HUANG H.‐L. , LIN C.‐L. , KO C.‐C. , CHANG C.‐H. , HSU J.‐T. , HUANG J.‐S.
Published: June 2006

summary  Three‐dimensional, anisotropic finite element models were executed to investigate the biomechanical effects of in‐line and offset placements of implants on implant‐supported partial prostheses. Three implant placements of finite element models were created: in‐line, buccal offset and lingual offset placements. The mesh models of a cadaver mandibular segment and a three‐united crown containing the 2nd premolar, the 1st molar and the 2nd molar were constructed by computer tomography images. The material properties of mandible were applied as transversely isotropic and linearly elastic. Two loading modes (100N), vertical and oblique, were evaluated in all models. Insignificant difference was observed in implant stresses between the in‐line and offset placements under the vertical loading mode. Under the oblique loading, however, the offset placement decreased the implant stress by a maximum of 17%. The maximum stress at cortical bone and trabecular bone around each implant did not show conspicuous difference between the in‐line and offset placements. This study demonstrated the mechanisms of how stresses were distributed between the in‐line and offset placements. Even though the offset placements showed the benefit of decreasing implant stresses, justified from the bone stress the offset placements provided no advantage for the stress decreasing over the in‐line placement.
Analysis of sagittal condylar path inclination in consideration of Fischer's angle
Authors: MATSUMURA H. , TSUKIYAMA Y. , KOYANO K.
Published: June 2006

summary  This study investigated the sagittal condylar path during protrusive and lateral excursions by analysing the actually measured jaw movement data and re‐evaluated the setting of the sagittal condylar path inclination in consideration of Fischer's angle. Protrusive and lateral excursions of 10 healthy subjects were measured using a three‐dimensional mandibular movement analysing system. Condylar path inclinations at the hinge‐axis point and the corresponding external point laterally extending from the condyle were evaluated in the sagittal plane. Fischer's angle was defined as the difference between the sagittal condylar inclinations during protrusive and lateral excursions on the non‐working side, by keeping the corresponding horizontal distance from the intercuspal position (ICP) equivalent at the incisal point. Analysis was performed at three different magnitudes of excursions, where the incisal point was located at 1, 3 and 5 mm away from the ICP. There was no significant difference in the sagittal condylar path inclination or the Fischer's angle between two condylar reference points. However, they were significantly different across the three different magnitudes of excursions for both condylar reference points, i.e. sagittal condylar path inclination (P = 0·003 for protrusive excursion, and P < 0·001 for lateral excursion respectively; two‐way repeated‐measures anova), and Fischer's angle (P = 0·013, two‐way repeated‐measures anova) became smaller as the incisal point became distant from the ICP. Moreover, 3‐ and 5‐mm eccentric positions were included in the 95% CI where Fischer's angle equals zero and were considered to be clinically acceptable to adjust the sagittal condylar inclination on the semiadjustable articulators.
Correlation of c‐erbB‐2 oncogene and p53 tumor suppressor gene with malignant transformation of hydatidiform mole
Authors: Yazaki‐Sun Sue , Daher Silvia , De Souza Ishigai Márcia Marcelino , Alves Maria Teresa Seixas , Mantovani Teresa Meire , Mattar Rosiane
Published: June 2006

Aim:  Considering the roles of c‐erB‐2 and p53 oncoproteins in tumor progression, we aimed to evaluate their expression in hydatidiform moles, and the possible predictive value of this immunoexpression in postmolar follow‐up.

Methods:  Group I comprised 35 patients with progression to gestational trophoblastic tumor, and group II included 32 patients with progression to spontaneous remission. Immunohistochemical tests were performed by streptavidin‐peroxidase method. c‐erbB‐2 immunoexpression was evaluated according to quantitative and semiquantitative criteria; p53 according to percentage of cells with stained nuclei. Data were analyzed by Student t‐test, Mann–Whitney test, ROC curve and logistic regression analysis.

Results:  c‐erbB‐2 and p‐53 expressions were significantly increased in group I. Quantitative and semiquantitative analysis of c‐erb‐2 showed that its expression may be associated with mole hydatidiform progression to gestational trophoblastic tumor. Taking into account cells with complete membranous delineation we proposed a cut‐off value of 10.8%. Similarly, considering the percentage of cells presenting nuclei marked by p53 we suggested a cut‐off value of 40.1% for the prediction of malignant transformation of mole hydatidiform.

Conclusions:  c‐erbB‐2 and p53 immunoexpression in hydatidiform mole are usually increased with malignant transformation. In addition to β‐fraction of human chorionic gonadotropin, they could possibly help the establishment of a therapeutic protocol.
Comparison of two freezing protocols in an open freezing system for cryopreservation of rat ovarian tissue
Authors: Maltaris Theodoros , Dimmler Arno , Müller Andreas , Hoffmann Inge , Beckmann Matthias W. , Dittrich Ralf
Published: June 2006

Aim:  To compare two freezing protocols in an automatic open‐vessel freezing system for cryopreservation of rat ovarian tissue.

Methods:  Ovarian tissue was transplanted heterotopically into the neck muscle, either without cryopreservation (group 1, n = 6) or with cryopreservation after equilibration with 1.5 mol/L dimethyl sulfoxide and propanediol (protocol A, group 2, n = 6) or 1.5 mol/L ethyl glycol (protocol B, group 3, n = 6). The ovarian tissue was examined with LIVE/DEAD fluorescent viability staining and histologically after isotransplantation.

Results:  The healthy follicular loss (intact oocyte and >50% granulosa cells alive) due to cryopreservation was 15.5% with protocol A and 12.2% with protocol B. Histological examination showed follicles in all developmental phases in all groups: group 1, 35.5 ± 5.7/mm2 (mean ± SD); group 2, 16.0 ± 5.0/mm2; group 3, 17.3 ± 5.7/mm2. The differences between groups 1 and 2 and between groups 1 and 3 were significant (P < 0.001). The difference between groups 2 and 3 was not significant (P = 0.33).

Conclusions:  These results demonstrate that the use of an open freezing system with both freezing protocols allows cryopreservation of rat ovarian tissue with equally good survival rates.
Effects of metformin on insulin resistance, androgen concentration, ovulation and pregnancy rates in women with polycystic ovary syndrome following laparoscopic ovarian drilling  THIS ARTICLE HAS BEEN RETRACTED
Authors: Kocak Idris , Üstün Cazip
Published: June 2006

Aim:  To evaluate the effects of metformin on insulin resistance, androgen concentration, ovulation rates and pregnancy rates in infertile women with polycystic ovary syndrome (PCOS).

Methods:  Forty‐two infertile women with PCOS were selected in this randomized clinical study. Basal steroid and gonadotropin levels were measured, and oral glucose tolerance test (OGTT) was performed. The patients were randomly divided into group 1 (n = 21) and group 2 (n = 21). Group 1 patients were treated with laparoscopic ovarian drilling (LOD). Group 2 patients underwent laparoscopic ovarian drilling (LOD) and received 1700 mg per day of metformin for 6 months. LOD was performed in women with PCOS using a unipolar electrode. Serum progesterone (P) level > 5 ng/mL was considered as a confirmation of ovulation. Ovulation and pregnancy rates were determined after six cycles.

Results:  Serum androgens and insulin response to OGTT decreased significantly after metformin therapy. Mean serum P levels and endometrial thickness were significantly higher in cycles treated with metformin plus LOD (34.6 ± 25.4 ng/mL, 8.4 ± 1.1 mm) than in those treated with LOD alone (26.2 ± 24.7 ng/mL, 7.9 ± 2.8 mm) (P < 0.05). The ovulation (56 of 65 cycles, 86.1% vs 29 of 65 cycles, 44.6%) and pregnancy rates (nine of 21 women, 47.6% vs four of 21 women, 19.1%) were significantly higher in group 2 than in group I.

Conclusions:  Metformin improves insulin resistance, reduces androgen levels and significantly increases the ovulation and pregnancy rates in infertile women, following LOD.
Randomized study of preoperative chemotherapy versus primary surgery for stage IB cervical cancer
Authors: Cai Hong‐Bing , Chen Hui‐Zhen , Yin Hou‐Han
Published: June 2006

Aim:  To determine the most effective treatment and long‐term outcome of patients with stage IB carcinoma of the cervix.

Methods:  From January 1999 to December 2001, 106 women with cervical cancer stage IB received neoadjuvant chemotherapy (n = 52) or primary surgery (n = 54). These were randomly assigned. Clinical effects and pathological changes were simultaneously recorded.

Results:  The overall clinical response rate was 84.6% and included a complete response (CR) in four patients (7.7%), partial response (PR) in 40 patients (76.9%), and stable disease (SD) in the remaining eight patients (15.4%). Surgery revealed positive nodes in 9.6% neoadjuvant chemotherapy group patients and in 29.6% primary surgery group patients (P = 0.014). Similar results occurred with vascular space involvement: 27.8% in the primary surgery group compared to 9.6% in the neoadjuvant chemotherapy group (P = 0.024). However, parametrial infiltration was found in 7.4% of the patients in the primary surgery group, while only 3.8% showed it in the neoadjuvant chemotherapy group (P = 0.679). The overall 5‐year survival rate was significantly higher for all patients who received neoadjuvant chemotherapy (84.6%) than for the control group (75.9%) (P = 0.0112). The median survival time in patients with complete response and partial response to chemotherapy (83.3 months) was significantly higher than that of patients with stable disease to chemotherapy (55.2 months) (P = 0.0049). 27.3% of patients developed recurrent disease within 5 years of the primary treatment. The women with recurrence included partial response in six patients (60.0%), and stable disease in four patients (40.0%). For the other patients there was partial response and complete response in 38 patients (90.5%), and stable disease in the remaining four patients (9.5%) (P = 0.035).

Conclusion:  Neoadjuvant chemotherapy can effectively eliminate the pathological risk factors and improve long‐term survival in patients with locally advanced cervical cancer.
LycoRed as an alternative to hormone replacement therapy in lowering serum lipids and oxidative stress markers: A randomized controlled clinical trial
Authors: Misra Renu , Mangi Sonika , Joshi Sujata , Mittal Suneeta , Gupta Suresh K. , Pandey Ravindra M.
Published: June 2006

Aim:  Menopause is a pro‐atherogenic state with a sharp rise in the incidence of coronary artery disease. This pilot study was designed as an equivalence randomized clinical trial to explore the potential of LycoRed (containing 2000 µg lycopene) as an alternative to hormone replacement therapy (HRT) for the prevention of coronary artery disease in postmenopausal women.

Methods:  Forty‐one healthy postmenopausal women were randomly allocated to receive either continuous combined HRT (n = 21) or LycoRed (n = 20) for six months. Serum lipid profile, marker of lipid peroxidation (malondialdehyde), and the level of endogenous antioxidant (glutathione) were measured at the baseline, and 3 and 6 months after the intervention in both groups.

Results:  At 6 months, HRT resulted in a significant decrease in total cholesterol (TC) level by 23.5%, low‐density lipoproteins (LDL) by 19.6%, and an increase in high‐density lipoproteins (HDL) by 38.9%. The LycoRed group showed similar changes in TC (−24.2%), LDL (−14.9%) and HDL (+26.1%). Triglyceride levels showed a smaller though significant increase at 6 months, but not at 3 months, in both groups. There was no significant change in the very LDL (VLDL) level in either group. Malondialdehyde levels decreased significantly by 16.3% and 13.3%, whereas glutathione levels increased significantly by 5.9% and 12.5% in HRT and LycoRed groups, respectively.

Conclusion:  Both HRT and LycoRed had a favorable effect on serum lipids and oxidative stress markers which were comparable. LycoRed can be used as an alternative to HRT to reduce the risk of atherosclerosis in postmenopausal women.
High prevalence of cervical squamous cell abnormalities among HIV‐infected women with immunological AIDS‐defining illnesses†
Authors: Chalermchockcharoenkit Amphan , Sirimai Korakot , Chaisilwattana Pongsakdi
Published: June 2006

Aim:  To assess the results of Pap smear at postpartum scheduled visit, especially the prevalence of squamous cell abnormalities including association with CD4+ T‐lymphocyte count (CD4+ count) levels at delivery among HIV‐infected women between the years 1996 and 2004.

Methods:  As part of the research and implementation programs of short course antiretroviral regimens for the prevention of mother to child perinatal HIV transmission in HIV‐infected pregnant women delivered at Siriraj hospital, CD4+ count at delivery and Pap smear at postpartum were evaluated.

Results:  Among 636 women, 13.3% had squamous cell abnormalities. Seventy‐seven cases (90.6%) of squamous cell abnormalities were low grade squamous intraepithelial lesions. The prevalence of squamous epithelial cell abnormalities detected by Pap smear, was higher in women whose CD4+ count at delivery was < 200 cells/µL than in women whose CD4+ count at delivery was ≥ 200 cells/µL, with a significant difference (21.2%vs 12.2%).

Conclusions:  All HIV‐infected pregnant women should be evaluated for clinical and immunological status during the antepartum period. Pelvic examination and Pap smear should be considered as a part of this evaluation. They should receive comprehensive health‐care services that continue after pregnancy, including postpartum gynecologic examination and Pap smear. Women with normal cervical cytological findings but low CD4+ count should be offered an antenatal Pap smear and long‐term follow‐up including a 6‐monthly Pap smear.
Transanal stent in anterior resection does not prevent anastomotic leakage
Authors: Bülow S. , Bulut O. , Christensen I. J. , Harling H. ,   The Rectal Stent Study Group
Published: June 2006

Objective  A defunctioning transanal stent may theoretically reduce the leakage rate after anterior rectal resection. We present a randomized open study with the aim of comparing the leakage rate after anterior resection with a loop ileostomy, a transanal stent, both or neither.

Patients and methods  Randomized open trial of 194 patients operated in 11 hospitals during September 2000 to September 2003 with anterior resection for a mobile rectal tumour, 115 men and 79 women, median age 68 years (range 37–90 years). The surgeon decided upon the use of a protective ileostomy, and after completion of the operation the patients were randomized in two groups with and without a transanal stent.

Results  A clinically significant leakage was diagnosed in 25 patients (13%). No significant difference was found 17 of 98 patients with a stent and 8 of 96 without (P = 0.09), or in 9 of 44 ileostomy patients with a stent and in 3 of 45 without (P = 0.07). Several leaks over a short time led to an interim analysis after inclusion of 194 of 448 planned patients. The analysis showed no significant protective effect of the stent, and more leakages in the stent group, although not statistically significant. On this basis it was decided to discontinue the study prematurely for ethical reasons.

Conclusion  Decompression of the anastomosis with a transanal stent does not reduce the risk of anastomotic leakage after anterior resection.
Rectal sensation, pelvic floor function and symptom severity in Hispanic population with irritable bowel syndrome with constipation
Authors: Awad R. A. , Camacho S. , Martín J. , Ríos N.
Published: June 2006

Objective  In patients with irritable bowel syndrome with constipation (IBS‐C, Rome II) we determined if pelvic floor function correlates with rectal sensitivity and tone, and if the pelvic and rectal measurements correlate with symptoms.

Patients and methods  Sensory thresholds and tone in fasting and postprandial states were evaluated with an electronic barostat in 34 patients and 10 normal controls. The pelvic floor was assessed by defaecography.

Results  Pain threshold to rectal distension was lower in IBS‐C patients (P = 0.007). Postprandially, IBS‐C patients showed lower values for sensation of gas, perception of urge, and pain threshold compared with controls. In IBS‐C the anorectal angle widened less and showed less perineal mobility during defecation; the rectal tone in fasting IBS‐C patients correlated with the angle at rest (P = 0.04) and with the perineal descent at rest (P = 0.01). The severity of abdominal discomfort or pain, and abdominal fullness correlated with the anorectal angle. The duration of symptoms and frequency of bowel movements correlated with perineal descent. Straining, mucus expulsion, and the feeling of incomplete evacuation correlated with rectal sensitivity variables.

Conclusion  Patients with IBS‐C have lowered sensory thresholds for noxious and non‐noxious stimuli, increased visceral sensitivity after food, less perineal mobility during defecation, and symptoms that correlate with rectal sensitivity and pelvic floor parameters.
The importance of accurate pathological assessment of lymph node involvement in colorectal cancer
Authors: Schofield J. B. , Mounter N. A. , Mallett R. , Haboubi N. Y.
Published: June 2006

This review presents an up‐to‐date analysis of the importance of accurate pathological lymph node staging in colorectal cancer. Lymph node staging is reliant on the technique of the surgeon and the pathologist as well as methods employed in the histopathology laboratory, and is vital for determining appropriate therapy. The significance of micrometastatic nodal disease is evaluated and new techniques for pathological evaluation are discussed. Recommendations for evaluation of lymph node status in colorectal cancer are provided based on current scientific evidence, and standardization of pathological dissection and laboratory handling is advocated.
From strategic planning to meaningful learning: diverse perspectives on the development of web‐based teaching and learning in higher education
Authors: Löfström Erika , Nevgi Anne
Published: June 2006

This paper reports the results of a study on strategic planning and implementation of information and communication technology (ICT) in teaching and describes the level of quality awareness in web‐based teaching at the University of Helsinki. Questionnaire survey data obtained from deans and institutional leaders, ICT support staff, teachers and students (n = 333) at the University indicate that strategic planning has proceeded well, and all the faculties of the University have developed virtual university strategies in order to continue existing ICT initiatives, to further increase the use of ICT in teaching and to assure student information literacy. The data indicate that all the faculties and institutions have monitored and reported the use of ICT in teaching, but quality assurance or enhancement as tools for monitoring were mentioned less frequently. The available ICT training was found satisfactory to meet the actual training needs of the teachers, but their lack of time was judged to be the main obstacle to their participation in it. The teachers identified two basic functions of ICT in teaching: (1) distribution of course material via the web, and (2) the creation of interactive and collaborative learning opportunities. The male teachers and students consistently estimated that their ICT skills were stronger when compared with the judgements made by female teachers and students. The teachers generally felt that the greatest problems arose from students’ lack of time management skills and from deficiencies in the usability of the technology. The students did not perceive lack of time management as a problem. Rather, they experienced isolation, loneliness and the lack of practical ICT usability to be the main obstacles to learning. The teachers had a higher assessment of students’ learning than the students did. The greatest difference between teachers and students concerned the contextual nature of learning in a virtual environment. The fact that the teachers’ views were markedly more positive signals a distinct challenge for pedagogy.
Blending online learning with traditional approaches: changing practices
Authors: Condie Rae , Livingston Kay
Published: June 2006

Considerable claims have been made for the development of e‐learning, either as stand‐alone programmes or alongside more traditional approaches to teaching and learning, for students across school and tertiary education. National initiatives have improved the position of schools in terms of access to hardware and electronic networking, software and educational resources, and staff development. The potential of e‐learning to improve learning and teaching, and in turn, attainment, may be contested by academics but the policy makers are generally positive. Many countries across Europe and North America have adopted information and communication technology (ICT) as a central plank in school improvement and effectiveness planning. At the centre, however, remain the teacher and the learner. The impact of ICT on the learning experience will depend upon the roles adopted by each, the model of the learner held by the teacher and the pedagogy adopted. This paper considers the ways in which teachers and students responded to the implementation of one particular online programme and considers the approaches adopted and the attitudes to its use. The SCHOLAR programme is designed to complement rather than replace traditional teaching and learning approaches within schools and is aimed at students in the post‐compulsory years of secondary school working towards external certification. It has a number of features including course materials, revision exercises, self‐assessment facilities and a discussion forum. The independent evaluation of SCHOLAR looked at the impact that its use made on learning and teaching in the post‐16 classroom and the differing ways in which teachers and students used the various elements of the programme. While it did appear to have a positive impact on attainment, the evidence indicates that this might have been greater had the teachers modified their practice, blending learning through SCHOLAR with more traditional methods.
Teaching, learning and new technology: a review for teachers
Authors: Hartley James
Published: June 2006

This paper reviews the effects of new technology on teaching and learning by considering examples of studies carried out with five kinds of teaching in five contexts. The five teaching situations are direct instruction, adjunct instruction, facilitating the skills of learning, facilitating social skills and widening learners’ horizons. The five contexts are primary schools, secondary schools, higher education, special education and out of school. The aim of the paper is primarily to inform teachers about current work in these different areas.
Expression of β‐defensin‐2 in human gingival epithelial cells in response to challenge with Porphyromonas gingivalis in vitro
Authors: Taguchi Y. , Imai H.
Published: June 2006

Background and Objective:  Human β‐defensin‐2 (hBD‐2) is an antimicrobial peptide that is produced by epithelial cells after stimulation with microorganisms and inflammatory mediators. Compared with gram‐positive bacteria, gram‐negative bacteria, which are typically detected in the periodontal pockets in periodontitis, elicit a stronger antibacterial peptide response of hBD‐2 by epithelial cells. The purpose of this study was to investigate the expression of hBD‐2 and relationships between it and inflammatory mediators in human gingival epithelial cells (HGEC) in response to challenge with Porphyromonas gingivalis in vitro.

Material and Methods:  mRNA expression of hBD‐2 in HGEC stimulated with or without P. gingivalis was assessed using a semiquantitative reverse transcription–polymerase chain reaction. Primary cultured HGEC were activated by live P. gingivalis, and inflammatory cytokine production was examined using an enzyme‐linked immunosorbent assay.

Results:  The level of hBD‐2 mRNA in HGEC treated with P. gingivalis increased with exposure time. After 48 h, the mRNA in P. gingivalis was significantly increased compared with that in control HGEC. The interleukin‐8 production rate was much greater in stimulated HGEC than in the control HGEC, almost always showing a significant difference after 3 h. The production of interleukin‐1β was not increased as much as that of interleukin‐8.

Conclusion:  These findings suggest that the expression of hBD‐2 in HGEC is P. gingivalis‐dependently induced and is likely to be connected with the initial stage of the inflammatory response.
Secondary Flows and Loss Caused by Blade Row Interaction in a Turbine Stage
Authors: Pullan Graham
Published: June 2006

A study of the three-dimensional stator-rotor interaction in a turbine stage is presented. Experimental data reveal vortices downstream of the rotor which are stationary in the absolute frame—indicating that they are caused by the stator exit flowfield. Evidence of the rotor hub passage vortices is seen, but additional vortical structures away from the endwalls, which would not be present if the rotor were tested in isolation, are also identified. An unsteady computation of the rotor row is performed using the measured stator exit flowfield as the inlet boundary condition. The strength and location of the vortices at rotor exit are predicted. A formation mechanism is proposed whereby stator wake fluid with steep spanwise gradients of absolute total pressure is responsible for all but one of the rotor exit vortices. This mechanism is then verified computationally using a passive-scalar tracking technique. The predicted loss generation through the rotor row is then presented and a comparison made with a steady calculation where the inlet flow has been mixed out to pitchwise uniformity. The loss produced in the steady simulation, even allowing for the mixing loss at inlet, is 10% less than that produced in the unsteady simulation. This difference highlights the importance of the time-accurate calculation as a tool of the turbomachine designer.
Unsteady Navier-Stokes Simulation of a Transonic Flutter Cascade Near-Stall Conditions Applying Algebraic Transition Models
Authors: Thermann Hans , Niehuis Reinhard
Published: June 2006

Due to the trend in the design of modern aeroengines to reduce weight and to realize high pressure ratios, fan and first-stage compressor blades are highly susceptible to flutter. At operating points with transonic flow velocities and high incidences, stall flutter might occur involving strong shock-boundary layer interactions, flow separation, and oscillating shocks. In this paper, results of unsteady Navier-Stokes flow calculations around an oscillating blade in a linear transonic compressor cascade at different operating points including near-stall conditions are presented. The nonlinear unsteady Reynolds-averaged Navier-Stokes equations are solved time accurately using implicit time integration. Different low-Reynolds-number turbulence models are used for closure. Furthermore, empirical algebraic transition models are applied to enhance the accuracy of prediction. Computations are performed two dimensionally as well as three dimensionally. It is shown that, for the steady calculations, the prediction of the boundary layer development and the blade loading can be substantially improved compared with fully turbulent computations when algebraic transition models are applied. Furthermore, it is shown that the prediction of the aerodynamic damping in the case of oscillating blades at near-stall conditions can be dependent on the applied transition models.
Improvement of a Film-Cooled Blade by Application of the Conjugate Calculation Technique
Authors: Kusterer Karsten , Hagedorn Torsten , Bohn Dieter , Sugimoto Takao , Tanaka Ryozo
Published: June 2006

The conjugate calculation technique has been used for the three-dimensional thermal load prediction of a film-cooled test blade of a modern gas turbine. Thus, it becomes possible to take into account the interaction of internal flows, external flow, and heat transfer without the prescription of heat transfer coefficients. The numerical models consist of all internal flow passages and cooling hole rows, including shaped holes. Based on the results, deficiencies of the test configuration close to the leading edge region and in the blade tip region have been detected, which lead to hot spots and surface areas of high thermal load. These regions of high thermal load have been confirmed by thermal index paint measurements in good agreement to the conjugate calculation results. Based on the experimental and numerical results, recommendations for the improvement of the blade cooling were derived and an improved blade-cooling configuration has been designed. The conjugate calculation results, as well as new measurement data, show that the changes in the cooling design have been successful with respect to cooling performance. Regions of high thermal load have vanished, and effective cooling is reached for all critical parts of the test blade.
Unsteady Flow in a Turbocharger Centrifugal Compressor: Three-Dimensional Computational Fluid Dynamics Simulation and Numerical and Experimental Analysis of Impeller Blade Vibration
Authors: Dickmann Hans-Peter , Secall Wimmel Thomas , Szwedowicz Jaroslaw , Filsinger Dietmar , Roduner Christian H.
Published: June 2006

Experimental investigations on a single stage centrifugal compressor showed that measured blade vibration amplitudes vary considerably along a constant speed line from choke to surge. The unsteady flow has been analyzed to obtain detailed insight into the excitation mechanism. Therefore, a turbocharger compressor stage impeller has been modeled and simulated by means of computational fluid dynamics (CFD). Two operating points at off-design conditions were analyzed. One was close to choke and the second one close to the surge line. Transient CFD was employed, since only then a meaningful prediction of the blade excitation, caused by the unsteady flow situation, can be expected. Actually, it was observed that close to surge a steady state solution could not be obtained; only transient CFD could deliver a converged solution. The CFD results show the effect of the interaction between the inducer casing bleed system and the main flow. Additionally, the effect of the nonaxisymmetric components, such as the suction elbow and the discharge volute, was analyzed. The volute geometry itself had not been modeled. It turned out to be sufficient to impose a circumferentially asymmetric pressure distribution at the exit of the vaned diffuser to simulate the volute. Volute and suction elbow impose a circumferentially asymmetric flow field, which induces blade excitation. To understand the excitation mechanism, which causes the measured vibration behavior of the impeller, the time dependent pressure distribution on the impeller blades was transformed into the frequency domain by Fourier decomposition. The complex modal pressure data were imposed on the structure that was modeled by finite element methods (FEM). Following state-of-the-art calculations to analyze the free vibration behavior of the impeller, forced response calculations were carried out. Comparisons with the experimental results demonstrate that this employed methodology is capable of predicting the impeller’s vibration behavior under real engine conditions. Integrating the procedure into the design of centrifugal compressors will enhance the quality of the design process.
Flow Analysis Inside a Pelton Turbine Bucket
Authors: Zoppé B. , Pellone C. , Maitre T. , Leroy P.
Published: June 2006

The aim of this work is to provide a detailed experimental and numerical analysis of the flow in a fixed bucket of a Pelton turbine. The head, jet incidence, and flow rate have been varied to cover a wide range of the turbine functioning points. The experimental analysis provides measurements of pressure and torque as well as flow visualization. The numerical analysis is performed with the FLUENT code using the two-phase flow volume of fluid method. The results present a good consistency with experimental data. In particular, the pressure distribution is very well predicted for the whole range of the studied parameters. A detailed analysis of torque and thrust allows evaluating the losses due to the edge and the cutout of the bucket. These results give insight into the benefit we can expect of steady flow calculations through the optimization process of the design of Pelton turbines.
Validation of Heat-Flux Predictions on the Outer Air Seal of a Transonic Turbine Blade
Authors: Clark John P. , Polanka Marc D. , Meininger Matthew , Praisner Thomas J.
Published: June 2006

It is desirable to accurately predict the heat load on turbine hot section components within the design cycle of the engine. Thus, a set of predictions of the heat flux on the blade outer air seal of a transonic turbine is here validated with time-resolved measurements obtained in a single-stage high-pressure turbine rig. Surface pressure measurements were also obtained along the blade outer air seal, and these are also compared to three-dimensional, Reynolds-averaged Navier-Stokes predictions. A region of very high heat flux was predicted as the pressure side of the blade passed a fixed location on the blade outer air seal, but this was not measured in the experiment. The region of high heat flux was associated both with very high harmonics of the blade-passing event and a discrepancy between predicted and measured time-mean heat-flux levels. Further analysis of the predicted heat flux in light of the experimental technique employed in the test revealed that the elevated heat flux associated with passage of the pressure side might be physical. Improvements in the experimental technique are suggested for future efforts.
On Vortex Formation in the Wake Flows of Transonic Turbine Blades and Oscillating Airfoils
Authors: Gostelow J. P. , Platzer M. F. , Carscallen W. E.
Published: June 2006

This paper demonstrates similarities between the vortex shedding from blunt trailing-edge transonic turbine nozzle blades and from oscillating airfoils and bluff bodies. Under subsonic conditions the turbine nozzle cascade shed wake vortices in a conventional von Kármán vortex street. This was linked with a depressed base pressure and associated energy separation in the wake. Under transonic conditions a variety of different shedding configurations was observed with vortices shedding and pairing in several different ways. Similarities are addressed between the observed structures and those from vortex shedding in some other physical situations, such as the vortex wakes shed from cylinders and airfoils in sinusoidal heaving motion in low-speed flow. The established field of vortex-induced vibration has provided a developed classification scheme for the phenomena observed. The paper has brought together three previously independent fields of investigation and, by showing that the three are essentially related, has provided the basis for a new synthesis.
Degradation of Film Cooling Performance on a Turbine Vane Suction Side due to Surface Roughness
Authors: Rutledge James L. , Robertson David , Bogard David G.
Published: June 2006

After an extended period of operation, the surfaces of turbine airfoils become extremely rough due to deposition, spallation, and erosion. The rough airfoil surfaces will cause film cooling performance degradation due to effects on adiabatic effectiveness and heat transfer coefficients. In this study, the individual and combined effects of roughness upstream and downstream of a row of film cooling holes on the suction side of a turbine vane have been determined. Adiabatic effectiveness and heat transfer coefficients were measured for a range of mainstream turbulence levels and with and without showerhead blowing. Using these parameters, the ultimate film cooling performance was quantified in terms of net heat flux reduction. The dominant effect of roughness was a doubling of the heat transfer coefficients. Maximum adiabatic effectiveness levels were also decreased significantly. Relative to a film cooled smooth surface, a film cooled rough surface was found to increase the heat flux to the surface by 30%–70%.
A Reduced-Order Model
for Transient Analysis of Bladed Disk Forced
Response
Authors: Ayers J. P. , Feiner D. M. , Griffin J. H.
Published: June 2006

A method for predicting the vibratory response of bladed disks under high engine acceleration rates is developed. The method is based on the Fundamental Mistuning Model, an existing reduced order model for predicting the steady-state vibratory response. In addition, a criterion is developed for a critical engine acceleration rate, above which transient effects play a large role in the response. It is shown that military engines operate at acceleration rates above this critical value and therefore transient effects are important in practice.
Bone marrow aspiration before bone marrow core biopsy using the same bone marrow biopsy needle: a good or bad practice?
Authors: Islam Anwarul
Published: June 2006

A single-needle single-site technique for bone marrow aspiration and core biopsy has been compared with a two-needle technique, using 30 randomly selected patients who required these two investigations. In addition, two single-needle techniques were compared, aspirating immediately after penetrating the cortex or, alternatively, aspirating after the needle (without the stilette) had been advanced 20–25 mm. The two-needle technique was found to be superior to either of the single-needle techniques, which often resulted in a biopsy specimen that was denuded of bone marrow cells.
Accuracy and clinical utility of the CoaguChek XS portable international normalised ratio monitor in a pilot study of warfarin home-monitoring
Authors: Bereznicki Luke R , Jackson Shane L , Peterson Gregory M , Jeffrey Ella C , Marsden Katherine A , Jupe David M
Published: June 2006

Aim:To evaluate the accuracy of the CoaguChek XS international normalised ratio (INR) monitor compared with the laboratory method.

Methods:The accuracy and ease of use of the recently marketed CoaguChek XS portable INR monitor was evaluated in 17 patients involved in a trial of warfarin home monitoring. INR results from the monitor were compared with those from the laboratory method. Clinical applicability was measured by discrepant INR values, defined in the literature by expanded and narrow agreement criteria, and by the proportion of INR values differing by >15% and by >20% from those derived by the laboratory method.

Results:Participants provided 59 comparison INR measurements for analysis. The paired results were highly correlated (r = 0.91). Expanded and narrow agreement between paired INR values occurred 100% of the time. Only three CoaguChek XS (5.1%) results differed by >15% compared with the laboratory method; no results differed by >20% or were discrepant by >0.5 INR units.

Conclusions:In the hands of patients the CoaguChek XS showed good correlation with laboratory determination of INR and compared well with expanded and narrow clinical agreement criteria. Both patients and doctors were highly satisfied with the accuracy and ease of use of the CoaguChek XS.
Simultaneous evaluation of maspin and CXCR4 in patients with breast cancer
Authors: Tsoli Efthimia , Tsantoulis Petros K , Papalambros Alexandros , Perunovic Branko , England David , Rawlands David A , Reynolds Gary M , Vlachodimitropoulos Dimitrios , Morgan Susan L , Spiliopoulou Chara A , Athanasiou Thanos , Gorgoulis Vassilis G
Published: June 2006

Aim:To study simultaneously the actions of maspin and CXCR4, which share several similar pathways in cancer, including apoptosis and angiogenesis.

Methods:Our material consisted of 151 invasive breast carcinomas arranged in a tissue microarray setting. Maspin and CXCR4 expression was evaluated by immunohistochemistry. Microvessel density was assessed by CD34 immunodetection and apoptosis by the Tdt-mediated dUTP nick end labelling assay.

Results:Maspin expression was related to CXCR4 expression, apoptosis, patient age and the Nottingham prognostic index. The expression of both maspin and CXCR4 progressively increased in high-grade tumours. In patients with lymph node negative breast cancer, maspin overexpression was associated with increased risk of death. High CXCR4 expression was associated with prolonged survival of patients with high maspin expression.

Conclusions:Our results show that maspin overexpression could prove to be a potentially useful marker, especially for the clinically important group of patients with lymph node negative breast cancer. The expression of CXCR4 is of less significance in our study, but may be informative for specific patient subsets or in a longer time frame.
Localised breast cancers may have systemic influences on skin and hair
Authors: Lawson James S , Tran Dinh D
Published: June 2006

Hypothesis:Biomarkers, commonly expressed in breast cancer cells, may be correlated with their expression in breast skin of the same subjects.

Methods:The expression of biomarkers in specimens from 33 breast tumours and breast skin from the same subject and from 32 normal controls was studied using immunohistochemical techniques.

Results:(1) In normal women, there are significant correlations between the levels of expression of cyclin D1, bcl-2 and p53 in normal breast epithelial cells and breast skin epithelial cells. (2) These patterns of biomarker expression in normal women are similar in breast cancer and breast skin epithelial cells of women with invasive ductal carcinoma (IDC) and ductal carcinoma in situ (DCIS), but are at significantly higher levels in both breast cancer cells and skin from the same subjects. (3) In normal women, human epidermal growth factor receptor 2 (HER-2) is not expressed in either breast epithelial cells or skin epithelial cells. (4) HER-2 is expressed in the breast skin of some subjects with HER-2-positive breast cancer. (5) Positive oestrogen receptor alpha expression occurs significantly more frequently in the breast skin of women with IDC and DCIS than in normal controls.

Conclusion:The influence of localised breast cancer seems to be systemic, and leads to changes in skin and hair.