bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cortical bone development under the growth plate is regulated by mechanical load transfer
Authors: Tanck E. , Hannink G. , Ruimerman R. , Buma P. , Burger E. H. , Huiskes R. 
Published: January 2006

AbstractLongitudinal growth of long bones takes place at the growth plates. The growth plate produces new bone trabeculae, which are later resorbed or merged into the cortical shell. This process implies transition of trabecular metaphyseal sections into diaphyseal sections. We hypothesize that the development of cortical bone is governed by mechanical stimuli. We also hypothesize that trabecular and cortical bone share the same regulatory mechanisms for adaptation to mechanical loads. To test these hypotheses, we monitored the development of the tibial cortex in growing pigs, using micro‐computer tomography and histology. We then tested the concept that regulatory mechanisms for trabecular bone adaptation can also explain cortical bone development using our mechanical stimulation theory, which could explain trabecular bone (re)modelling. The main results showed that, from the growth plate towards the diaphysis, the pores of the trabecular structure were gradually filled in with bone, which resulted in increased density and cortical bone. The computer model largely predicted this morphological development. We conclude that merging of metaphyseal trabeculae into cortex is likely to be governed by mechanical stimuli. Furthermore, cortex development of growing long bones can be explained as a form of trabecular bone adaptation, without the need for different regulatory mechanisms for cortical and trabecular bone.
Calcium phosphate microcrystal deposition in the human intervertebral disc
Authors: Lee Robert S. , Kayser Mike V. , Ali S. Yousuf 
Published: January 2006

AbstractA variety of crystals have been identified in both normal and pathological connective tissues. Calcium phosphate ‘cuboidal’ microcrystal deposition has been found, using transmission electron microscopy (TEM), in femoral articular cartilage, where they are distributed as a band 5–50 µm beneath the articular surface. These cuboid microcrystals have been identified as magnesium whitlockite. Our objective was to investigate their presence in the human intervertebral disc. In this study, two degenerate and 15 scoliotic discs were examined using light microscopy and TEM techniques to determine the presence of calcium phosphate crystals. Calcium pyrophosphate dihydrate (CPPD) deposition was identified in one degenerate disc specimen. Using TEM and electron probe analysis, cuboid microcrystals were identified in the annulus fibrosus and nucleus pulposus of both degenerate specimens, but not in the discs from young scoliotic patients. Cuboid microcrystal deposition was found predominantly around cells, which were mainly necrotic, with some association with extracellular lipidic/membranous debris. This is the first TEM report of whitlockite in the intervertebral disc. In one specimen coexistence of cuboid and CPPD crystal deposition was found.
The elephant knee joint: morphological and biomechanical considerations
Authors: Weissengruber G. E. , Fuss F. K. , Egger G. , Stanek G. , Hittmair K. M. , Forstenpointner G. 
Published: January 2006

AbstractElephant limbs display unique morphological features which are related mainly to supporting the enormous body weight of the animal. In elephants, the knee joint plays important roles in weight bearing and locomotion, but anatomical data are sparse and lacking in functional analyses. In addition, the knee joint is affected frequently by arthrosis. Here we examined structures of the knee joint by means of standard anatomical techniques in eight African (Loxodonta africana) and three Asian elephants (Elephas maximus). Furthermore, we performed radiography in five African and two Asian elephants and magnetic resonance imaging (MRI) in one African elephant. Macerated bones of 11 individuals (four African, seven Asian elephants) were measured with a pair of callipers to give standardized measurements of the articular parts. In one Asian and three African elephants, kinematic and functional analyses were carried out using a digitizer and according to the helical axis concept. Some peculiarities of healthy and arthrotic knee joints of elephants were compared with human knees. In contrast to those of other quadruped mammals, the knee joint of elephants displays an extended resting position. The femorotibial joint of elephants shows a high grade of congruency and the menisci are extremely narrow and thin. The four‐bar mechanism of the cruciate ligaments exists also in the elephant. The main motion of the knee joint is extension–flexion with a range of motion of 142°. In elephants, arthrotic alterations of the knee joint can lead to injury or loss of the cranial (anterior) cruciate ligament.
Osteonal crack barriers in ovine compact bone
Authors: Mohsin S. , O'Brien F. J. , Lee T. C. 
Published: January 2006

AbstractBone is an anisotropic structure which can be compared to a composite material. Discontinuities within its microstructure may provide stress concentration sites for crack initiation, but act as a barrier to its propagation. This study looks specifically at the relationship between crack length and propagation in compact bone. Beam‐shaped bone samples from sheep radii were prepared and stained with fluorochrome dyes and tested in cyclic fatigue under four‐point bending in an INSTRON 1341 servo‐hydraulic fatigue‐testing machine. Samples were tested at a frequency of 30 Hz and stress range of 100 MPa under load control. Specimens were sectioned transversely using a diamond saw, slides prepared and examined using epifluorescence microscopy. Cracks in transverse sections were classified in terms of their location relative to cement lines surrounding secondary osteons. Mean crack length, crack numerical density and crack surface density were examined. Short microcracks (100 µm or less) were stopped at the cement lines surrounding osteons, microcracks of intermediate length (100–300 µm) were deflected as they hit the cement line, and microcracks that were able to penetrate through cement lines were longer (> 400 µm). These data show that bone microstructure allows the initiation of microcracks but acts as a barrier to crack propagation.
The functional anatomy of Kager's fat pad in relation to retrocalcaneal problems and other hindfoot disorders
Authors: Theobald P. , Bydder G. , Dent C. , Nokes L. , Pugh N. , Benjamin M. 
Published: January 2006

AbstractKager's fat pad is a mass of adipose tissue occupying Kager's triangle. By means of a combined magnetic resonance imaging, ultrasound, gross anatomical and histological study, we show that it has three regions that are closely related to the sides of the triangle. Thus, it has parts related to the Achilles and flexor hallucis longus (FHL) tendons and a wedge of fat adjacent to the calcaneus. The calcaneal wedge moves into the bursa during plantarflexion, as a consequence of both an upward displacement of the calcaneus relative to the wedge and a downward displacement of the wedge relative to the calcaneus. During dorsiflexion, the bursal wedge is retracted. The movements are promoted by the tapering shape of the bursal wedge and by its deep synovial infolds. Fibrous connections linking the fat to the Achilles tendon anchor and stabilize it proximally and thus contribute to the motility of its tip. We conclude that the three regions of Kager's fat pad have specialized functions: an FHL part which contributes to moving the bursal wedge during plantarflexion, an Achilles part which protects blood vessels entering this tendon, and a bursal wedge which we suggest minimizes pressure changes in the bursa. All three regions contribute to reducing the risk of tendon kinking and each may be implicated in heel pain syndromes.
Morphological characterization of GFP stably transfected adult mesenchymal bone marrow stem cells
Authors: Raimondo Stefania , Penna Claudia , Pagliaro Pasquale , Geuna Stefano 
Published: January 2006

AbstractIncreasing attention is being given to the use of adult rather than embryonic stem cells, both for research and for the development of transplantation treatments for human disease. In particular, mesenchymal bone marrow stem cells have been studied extensively because of their ability to self‐renew and to give rise to various differentiated cell types, and because of the relative ease with which they can be obtained and cultured. In addition, the possibility of labelling stem cells with green fluorescent protein before transplantation has opened new and promising perspectives for their use in basic research. Because no structural or ultrastructural description of adult mesenchymal stem cells is available in the literature, this paper describes their morphology as revealed by light, confocal and electron microscopy, focusing on cells that are particularly suitable for transplantation studies, i.e. those derived from rat bone marrow transfected with green fluorescent protein. The results provide a basis for experimental studies of the differentiation of these cells in normal and pathological tissues.
Geometric morphometrics of the shoulder girdle in extant turtles (Chelonii)
Authors: Depecker Marion , Berge Christine , Penin Xavier , Renous Sabine 
Published: January 2006

AbstractThe aim of this study was to identify shape patterns of the shoulder girdle in relation to different functional and environmental behaviours in turtles. The Procrustes method was used to compare the shoulder girdles (scapula and coracoid) of 88 adult extant turtles. The results indicate that four shape patterns can be distinguished. The shoulder girdles of (1) terrestrial (Testudinidae), (2) highly aquatic freshwater (Trionychidae, Carettochelyidae) and (3) marine turtles (Cheloniidae, Dermochelyidae) correspond to three specialized morphological patterns, whereas the shoulder girdle of (4) semi‐aquatic freshwater turtles (Bataguridae, Chelidae, Chelydridae, Emydidae, Kinosternidae, Pelomedusidae, Platysternidae, Podocnemididae) is more generalized. In terrestrial turtles, the long scapular prong and the short coracoid are associated with a domed shell and a mode of locomotion in which walking is predominant. By contrast, highly aquatic freshwater turtles share traits with marine turtles. In both, the short scapular prong and the long coracoid are associated with a flat shell, and swimming locomotion. The enlarged attachment sites of the biceps, coracobrachialis magnus, and supracoracoideus also give these strong swimmers a mechanical advantage during adduction and retraction of the arm. Increasing size leads to allometrical shape changes that emphasize mechanical efficiency both in terrestrial and in aquatic turtles.
Three‐dimensional study of pelvic asymmetry on anatomical specimens and its clinical perspectives
Authors: Boulay Christophe , Tardieu Christine , Bénaim Charles , Hecquet Jérome , Marty Catherine , Prat‐Pradal Dominique , Legaye Jean , Duval‐Beaupère Ginette , Pélissier Jacques 
Published: January 2006

AbstractThe aim of this study was to assess pelvic asymmetry (i.e. to determine whether the right iliac bone and the right part of the sacrum are mirror images of the left), both quantitatively and qualitatively, using three‐dimensional measurements. Pelvic symmetry was described osteologically using a common reference coordinate system for a large sample of pelvises. Landmarks were established on 12 anatomical specimens with an electromagnetic Fastrak system. Seventy‐one paired variables were tested with a paired t‐test and a non‐parametric test (Wilcoxon). A Pearson correlation matrix between the right and left values of the same variable was applied exclusively to values that were significantly asymmetric in order to calculate a dimensionless asymmetry index, ABGi, for each variable. Fifteen variables were significantly asymmetric and correlated with the right vs. left sides for the following anatomical regions: sacrum, iliac blades, iliac width, acetabulum and the superior lunate surface of the acetabulum. ABGi values above a threshold of ± 4.8% were considered significantly asymmetric in seven variables of the pelvic area. Total asymmetry involving the right and the left pelvis seems to follow a spiral path in the pelvis; in the upper part, the iliac blades rotate clockwise, and in the lower part, the pubic symphysis rotates anticlockwise. Thus, pelvic asymmetry may be evaluated in clinical examinations by measuring iliac crest orientation.
Computer interviewing in urogynaecology: concept, development and psychometric testing of an electronic pelvic floor assessment questionnaire in primary and secondary care
Authors: Radley SC , Jones GL , Tanguy EA , Stevens VG , Nelson C , Mathers NJ 
Published: January 2006

Objective  To develop and evaluate a Web‐based, electronic pelvic floor symptoms assessment questionnaire (e‐PAQ)1 for women.Design  A cross‐sectional study in primary and secondary care.Setting  Two general practices, two community health clinics and a secondary care urogynaecology clinic.Sample  A total of 432 women (204 in primary care and 228 in secondary care) were recruited between June 2003 and January 2004.Methods  The e‐PAQ was located on a workstation (computer, touchscreen and printer). Women completed the e‐PAQ prior to their appointment. Untreated women in primary care were asked to return seven days later to complete the e‐PAQ a second time (test–retest).Main outcome measures  Factor analysis, reliability, validity, patient satisfaction, completion times and system costs.Results  In secondary care, factor analysis identified 14 domains within the four dimensions (urinary, bowel, vaginal and sexual symptoms) with internal consistency (Cronbach's alpha) ≥ 0.7 in 11 of these. In primary care, alpha values were all ≥ 0.7 and test–retest analysis found acceptable intraclass correlations of 0.50−0.95 (P < 0.001) for all domains. A measure of face validity and utility was gained using a nine‐item questionnaire, which yielded strongly positive patient views on relevance and acceptability.Conclusions  The e‐PAQ offers a user‐friendly clinical tool, which provides valid and reliable data. The system offers comprehensive symptoms and quality of life evaluation and may enhance the clinical episode as well as the quality of care for women with pelvic floor disorders.
Comparison of the maternal experience and duration of labour in two upright delivery positions—a randomised controlled trial
Authors: Ragnar I , Altman D , Tydén T , Olsson S‐E 
Published: January 2006

Objective  To compare two upright delivery positions at the second stage of labour in healthy primiparous women with regard to duration of the second stage of labour and maternal experience.Design  A randomised controlled trial.Setting  A county hospital delivery ward.Sample  Primiparous subjects (n= 271) were randomly allocated to a kneeling (n= 138) or a sitting (n= 133) position during the second stage of labour. A postpartum questionnaire was answered by 264/271 women (97%) participating in the trial.Methods  Primiparous subjects were randomised to a kneeling or sitting delivery position during second stage of labour. Analysis was performed on an intention‐to‐treat basis.Main outcome measure  Duration of the second stage of labour.Results  A comparison of the duration of the second stage of labour (kneeling 48.5 minutes ± 27.6 SD, sitting 41 minutes ± 23.4 SD) revealed no significant difference between the groups. A sitting position during the second stage of labour was associated with a higher level of delivery pain (P < 0.01), a more frequent perception of the second stage as being long (P= 0.002), less comfort for giving birth (P= 0.03) and more frequent feelings of vulnerability (P= 0.05) and exposure (P= 0.02). There were no significant differences in the frequency of sphincter ruptures although a sitting position was associated with a higher degree of postpartum perineal pain (P < 0.001) (Table 3).

Qualitative outcome of second stage of labour at a sitting position compared with kneeling

Sitting, n= 133
Kneeling, n= 138
Logistic regression analysis, adjusted odds ratio (95% CI)

Did you experience the position comfortable for giving birth?*
1
1
0.5 (0.1–0.9), P= 0.03

Did you feel vulnerable in the position?*
3
2
2.1 (0.9–4.6), P= 0.05

Did you feel exposed in the position?*
2
1
1.7 (1.5–1.9), P= 0.02

Did you feel safe in the position during pushing?*
1
1
0.9 (0.7–1.3), P= 0.7

Did you experience the second stage as long?**
69
37
1.4 (0.8–0.9), P= 0.002

How much did you participate during the pushing?**
5
10
1.2 (0.9–1.2), P= 0.13

How much pain did you experience in the assigned position?**
33
17
1.3 (1.1–1.9), P= 0.01

Do you experience postpartum perineal pain?*
2
1
1.9 (1.3–2.9), P= 0.001

Do you consider your delivery difficult?*
2
1
1.7 (1.4–2.0), P= 0.01

Would you give birth in the same position again?***
95 (89)
92 (82)
0.89 (0.47–1.4), P= 0.43

Median score, 0–3: 0 = not at all; 1 = some; 2 = a lot; 3 = very much.

Visual analogue scale 0–100.

Yes, number of subjects (%).

Conclusions  Kneeling and sitting upright during the second stage of labour do not significantly differ from one another in duration of the second stage of labour. In healthy primiparous women, a kneeling position was associated with a more favourable maternal experience and less pain compared with a sitting position.
Decreased maternal lipolysis in intrauterine growth restriction in the third trimester
Authors: Diderholm B , Stridsberg M , Nordén‐Lindeberg S , Gustafsson J 
Published: January 2006

Objective  Intrauterine growth restriction (IUGR) is a common complication of pregnancy. There are many possible aetiologic factors of maternal, placental and/or fetal origin. Often there is no known explanation. The aim of this study was to investigate whether a reduction in maternal energy substrate production could be one of the factors involved in IUGR.Design  Measurement of maternal energy substrate production and glucoregulatory hormones in women with growth‐restricted fetuses.Settings  University Hospital, Uppsala, Sweden.Population  Ten healthy pregnant women with IUGR were compared with eight recently reported healthy women with normal pregnancies. The women were studied at 35.4 ± 1.6 weeks of gestation after an overnight fast.Methods  Rates of glycerol and glucose production were analysed by gas chromatography/mass spectrometry following constant‐rate infusion of [1,1,2,3,3‐2H5]glycerol and [6,6‐2H2]glucose.Main outcome measure  Third trimester glycerol and glucose production.Results  Glycerol production, reflecting lipolysis, was lower in the women with IUGR than in those with normal pregnancies, 2.36 ± 0.58 versus 3.06 ± 0.66 μmol kg−1 minute−1 (P= 0.033), whereas there was no difference in rate of glucose production (glucose production rate [GPR]), 12.1 ± 1.5 versus 13.2 ± 1.5 μmol kg−1 minute−1 (P= 0.23). Plasma glycerol levels were increased in the women with IUGR (P= 0.008).Conclusions  Lipolysis is lower in pregnancies complicated by IUGR as compared with normal pregnancies. Increased lipolysis during pregnancy provides substrate for maternal energy metabolism, which spares glucose for the fetus. A reduced maternal production of energy substrate could be one of several factors underlying IUGR. A lack of relationship between insulin levels and either lipolysis or GPR suggests defective regulation of energy substrate production in this group of pregnant women.
Periodontal disease and adverse pregnancy outcomes: a systematic review
Authors: Xiong X , Buekens P , Fraser WD , Beck J , Offenbacher S 
Published: January 2006

Background  Recent studies suggest that periodontal disease, as a source of subclinical and persistent infection, may induce systemic inflammatory responses that increase the risk of adverse pregnancy outcomes.Objectives  To examine the existing evidence on the relationship between periodontal disease and adverse pregnancy outcomes.Search strategy  Published studies identified via searches of the MEDLINE, EMBASE, CINAHL, and Current Contents full‐text databases.Selection criteria  We identified and selected observational studies (i.e. case–control, cross‐sectional, and cohort) and nonrandomised controlled studies or randomised controlled trials that examined periodontal disease as a risk factor for adverse pregnancy outcomes.Data collection and analysis  Odds ratios (OR) or risk ratios (RR) were extracted or calculated from the studies’ data. We calculated pooled effect size for two clinical controlled trials but not for the observational studies due to the heterogeneity in definitions for periodontal disease and adverse pregnancy outcomes across studies.Main results  Twenty‐five studies (13 case–control, 9 cohort, and 3 controlled trials) were identified. The studies focused on preterm low birthweight, low birthweight, preterm birth, birthweight by gestational age, miscarriage or pregnancy loss, and pre‐eclampsia. Of the chosen studies, 18 suggested an association between periodontal disease and increased risk of adverse pregnancy outcome (ORs ranging from 1.10 to 20.0) and 7 found no evidence of an association (ORs ranging from 0.78 to 2.54). Three clinical trial studies suggest that oral prophylaxis and periodontal treatment can lead to a 57% reduction in preterm low birthweight (pooled RR 0.43; 95% CI 0.24–0.78) and a 50% reduction in preterm births (RR 0.5; 95% CI 0.20–1.30).Author's conclusions  Periodontal disease may be associated with an increased risk of adverse pregnancy outcome. However, more methodologically rigorous studies are needed for confirmation.
Does a first trimester dating scan using crown rump length measurement reduce the rate of induction of labour for prolonged pregnancy? An uncompleted randomised controlled trial of 463 women
Authors: Harrington DJ , MacKenzie IZ , Thompson K , Fleminger M , Greenwood C 
Published: January 2006

Objective  To evaluate the effect of a first trimester ultrasound dating scan on the rate of induction of labour for prolonged pregnancy.Design  Randomised controlled trial to include 400 women in each arm of the trial.Setting  Participating general practices and a district general teaching hospital.Population  Women attending their general practitioner in the first trimester to confirm pregnancy, in whom a first trimester ultrasound scan was not indicated.Methods  Women randomised to the study group (scan group) underwent an ultrasound dating scan between 8 and 12 weeks, measuring crown‐rump length. The estimated date of delivery (EDD) was changed if there was a discrepancy of more than 5 days from the gestation, calculated from the last menstrual period (LMP). For the remaining women (no‐scan group), gestation was determined using the LMP.Main outcome measures  The rate of induction of labour for prolonged pregnancy.Results  Due to circumstances beyond the researchers’ control, recruitment was abandoned when 463 women had been enrolled. The EDD was adjusted in 13 (5.7%) women in the scan group and in 2 (0.9%) in the no‐scan group. There was no difference in the rate of induction for prolonged pregnancy between the scan (19 [8.2%]) and the no‐scan (17 [7.4%]) groups (relative risk 1.10; 95% CI 0.59–2.07).Conclusions  Acknowledging the reduced numbers recruited for study, it is concluded that there is no evidence that a first trimester ultrasound dating scan reduces the rate of induction of labour for prolonged pregnancy and may result in a more expensive healthcare strategy.