bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimized differential diagnosis of breast lesions by combined B‐mode and color Doppler sonography
Authors: Schelling M. , Gnirs J. , Braun M. , Busch R. , Maurer S. , Kuhn W. , Schneider K. T. M. , Graeff H.
Published: March 2003

To optimize the sensitivity and specificity of gray‐scale imaging and color Doppler in breast tumor diagnosis, alone and in combination, 89 women with palpable breast masses were scanned preoperatively and standard parameters were determined in both modes. Parameters significant for differentiation of benign and malignant tumors identified using univariate analysis were combined and weighted using multivariate analysis (multiple logistic regression). Histologically 59 tumors were malignant and 30 benign. Gray‐scale sonography alone achieved a sensitivity of 88% and a specificity of 96% using the parameters of wall structure and posterior acoustic attenuation. Color Doppler achieved a sensitivity of 85% and a specificity of 79% using resistance index and pulsatility index as parameters. Combination of both methods yielded an accurate diagnosis in 84/87 patients (sonographic lesion correlates were absent in two cases), equivalent to a sensitivity of 97% and a specificity of 96%. Thus the individual diagnostic performance of gray‐scale imaging and color Doppler sonography in palpable breast disease is further enhanced using multiple logistic regression to combine independently significant parameters. Copyright © 1997 International Society of Ultrasound in Obstetrics and Gynecology
Intrauterine device localization by three‐dimensional transvaginal sonography
Authors: Lee A. , Eppel W. , Sam C. , Kratochwil A. , Deutinger J. , Bernaschek G.
Published: March 2003

Our objective was to investigate the possible role of three‐dimensional transvaginal ultrasound in the visualization of an intrauterine device (IUD) for routine follow‐up after insertion. A total of 96 women were examined after insertion of a TCu380A IUD. Three‐dimensional ultrasonographic imaging was carried out using a special vaginal probe and a commercially available ultrasound machine at a mean interval of 22 days after insertion.

Complete simultaneous imaging of all parts of the IUD was possible in 95% of cases. In the three‐plane mode, all parts of the IUD could be visualized in 44% and in a further 30 cases this was possible only after volume rendering. In two women., incomplete opening of the two arms of the device was demonstrated. In one of these cases, the entire IUD was displaced into the cervical canal. In another case, an intrauterine pregnancy was found together with an IUD in the correct position.

Three‐dimensional ultrasound provides useful information on the location of the IUD following insertion. It enables imaging of the entire IUD, i.e. the shaft and the arms, simultaneously. Additionally, the examination time can be kept to a minimum with this new technique. Copyright © 1997 International Society of Ultrasound in Obstetrics and Gynecology
Prenatal diagnosis of body stalk anomaly in the first trimester of pregnancy
Authors: Ginsberg N. E. , Cadkin A. , Strom C.
Published: March 2003

Ultrasound examination in a 10‐week fetus demonstrated a marked deformity of the lower half of the fetus that was in the celomic cavity, and the upper half of the body was in the amniotic sac. There was abdominal wall defect with herniation of the liver and bowel, the lower limbs were deformed and the umbilical cord was short and thin. These abnormalities were suggestive of body stalk anomaly. The diagnosis was confirmed by pathological examination after termination of the pregnancy at 18 weeks. Copyright © 1997 International Society of Ultrasound in Obstetrics and Gynecology
Pulsatility index in the fetal anterior tibial artery during the second half of normal pregnancy
Authors: Wisser J. , Kurmanavicius J. , Müller C. , Huch A. , Huch R.
Published: March 2003

The objective of this prospective study was to establish reference values for the pulsatility index in the fetal anterior tibial artery during the second half of pregnancy. Pulsed Doppler waveform analysis of 203 fetuses at 23–42 weeks of pregnancy was performed, each fetus being examined just once. There were neither fetal nor maternal complications detectable at the time of the examination. In the first 14 fetuses from which recordings were taken, Doppler examination was performed on both fetal legs in order to evaluate systematic differences between the right and left legs. Intraobserver variability was analyzed by repetition of the measurements by the same examiner in the first 130 cases.

There was no difference between right and left tibial circulation. The repeatability coefficient, defined as the 95% range for the difference in two repeat measurements, was 1.08. The pulsatility index of the anterior tibial artery (50th centile) increased slightly from 3.29 at 23 weeks of pregnancy to 4.09 at 42 weeks. The 5th and 95th centiles were calculated, as was the 95% confidence interval of the 5th and 95th centiles.

Examination of the fetal peripheral circulation during the second half of pregnancy is possible with a high degree of precision. Whether there are changes in peripheral arterial circulation in compromised fetuses remains to be evaluated. Copyright © 1998 International Society of Ultrasound in Obstetrics and Gynecology
Prenatal sonographic diagnosis of conjoined twins in the first trimester: two case reports
Authors: Lam Y. H. , Sin S. Y. , Lam C. , Lee C. P. , Tang M. H. Y. , Tse H. Y.
Published: March 2003

Conjoined twins are a rare occurrence. We present two cases of conjoined twins diagnosed by ultrasound examination at 8 and 13 weeks' gestation, respectively. These cases demonstrated the possibility of making an accurate diagnosis of conjoined twins and delineating the extent of organ sharing in the first trimester. Copyright © 1998 International Society of Ultrasound in Obstetrics and Gynecology
Three‐dimensional transvaginal sonography of conjoined twins at 10 weeks: a case report
Authors: Maymon R. , Halperin R. , Weinraub Z. , Herman A. , Schneider D.
Published: March 2003

Early and accurate prenatal diagnosis of conjoined twins is still a challenge, and is important when planning a favorable outcome for the mother and infants. We present a case diagnosed with transvaginal and three‐dimensional ultrasound at 10 weeks of gestation, and discuss the contribution of this relatively new scanning modality. Copyright © 1998 International Society of Ultrasound in Obstetrics and Gynecology
O'Sullivan's hydrostatic reduction of an inverted uterus: sonar sequence recorded
Authors: Ward H. R. G.
Published: March 2003

A case of acute uterine inversion which was successfully managed with hydrostatic reduction is reported. A sequence of sonograms demonstrating this is presented, as far as we are aware, for the first time. Copyright © 1998 International Society of Ultrasound in Obstetrics and Gynecology
Prenatal diagnosis of aortic insufficiency
Authors: Paladini D. , Russo M. , Palmieri S. , Morra T. , Pacileo G. , Martinelli P.
Published: March 2003

The prenatal diagnosis of various forms of left ventricular outflow tract obstruction has been reported in detail. However, the appearance and the characteristics of fetal aortic insufficiency have been described only in association with complete absence of the valve. We report here a case of aortic insufficiency associated with severe aortic stenosis. Features characteristic of insufficiency were severe cardiomegaly due to left ventricle dilatation and the hypocontractility of the myocardium. The aortic root was enormously dilated and the semilunar valve showed thick and dysplastic cusps. On color Doppler, the retrograde high‐velocity regurgitant jet was clearly visible. Copyright © 1998 International Society of Ultrasound in Obstetrics and Gynecology
Prenatal detection of cerebral lesions in a fetus with tuberous sclerosis
Authors: Sgro M. , Barozzino T. , Toi A. , Johnson J. , Sermer M. , Chitayat D.
Published: March 2003

We report a newborn, diagnosed prenatally with both cardiac rhabdomyomas and a brain tumor. To the best of our knowledge, this is the first report of central nervous system (CNS) lesions detected prenatally in a child with tuberous sclerosis with term follow‐up. At 36 months, the child has normal growth and is developing appropriately. Thus the finding of CNS tumors on fetal ultrasound examination can help in the prenatal diagnosis of tuberous sclerosis but does not necessarily indicate a poor prognosis. Copyright © 1999 International Society of Ultrasound in Obstetrics and Gynecology
Customized fetal weight limits for antenatal detection of fetal growth restriction
Authors: De Jong C.L.D. , Francis A. , Van Geijn H.P. , Gardosi J.
Published: March 2003

Objective
 To define cut‐off limits for individually adjustable fetal weight standards for the detection of intrauterine growth restriction.

Design
 Retrospective study, with the outcome measures small‐for‐gestational age (SGA) birth weight, operative delivery for fetal distress, umbilical artery pH < 7.15, and admission to the neonatal intensive care unit.

Subjects and Methods
 Two hundred and fifteen women considered to be at increased risk of uteroplacental insufficiency were recruited to a study of serial ultrasound scans. Fetal weights were derived using standard formulae and, retrospectively, weight percentiles were calculated after individual adjustment for maternal height, weight in early pregnancy, ethnic group, parity and fetal sex.

Introduction
 One or more antenatal scans indicative of fetal weight below the 10th customized percentile were predictive for a SGA neonate at birth (P < 0.001), operative delivery for fetal distress (P < 0.01) and admission to neonatal intensive care (P < 0.01) but not for a low umbilical artery pH (P = 0.6). Receiver–operator curves showed the optimal customized fetal weight percentile limit for predicting an SGA neonate to be the 18th percentile (sensitivity 83%, specificity 79%, positive predictive value 63% and negative predictive value 92%). For the prediction of operative delivery for fetal distress and admission to neonatal intensive care, the optional customised cut‐off value was the 8th percentile.

Conclusions
 The assessment of fetal weight using ultrasound and an individually‐adjusted standard is predictive of growth restriction and perinatal events associated with hypoxia or diminished reserve. The optimal cut‐off value for predicting operative delivery for fetal distress or admission to the neonatal intensive care unit suggests that the 10th customized percentile is a good limit for clinical use.
Fetuses and infants with congenital urinary system anomalies: correlation between prenatal ultrasound and postmortem findings
Authors: Isaksen C.V. , Eik‐Nes S.H. , Blaas H.‐G. , Torp S.H.
Published: March 2003

Objective Detection of congenital urinary system anomalies is an important part of the prenatal ultrasound examination. The present study compares prenatal ultrasonographic findings and postmortem examinations of fetuses and infants with renal and urinary tract anomalies.

Design Criteria for inclusion were an ultrasound examination at the National Center for Fetal Medicine (Trondheim, Norway) and autopsy performed during the period 1985–94. Results from the ultrasound examination and autopsy regarding urinary system anomalies were categorized according to the degree of concordance.

Results Urinary system anomalies were found in 112 (27%) of 408 fetuses with congenital anomalies. The renal and/or urinary tract anomaly was the principal reason for induced abortion or cause of death in 50 cases (45%). In 97 (87%) of the 112 cases there was full agreement between the ultrasound observations and the autopsy findings. In five cases the autopsy revealed minor findings not mentioned in the ultrasound report. The main diagnosis was thus correct in 102 cases (91%). In four cases major autopsy findings had not been found by ultrasound examination; in another four, none of the autopsy findings were suspected by ultrasound, and in two, minor ultrasound findings were not confirmed at autopsy.

Conclusions The accordance between ultrasound diagnoses and postmortem examinations proved to be satisfactory. The close co‐operation between ultrasonographers and perinatal pathologists is mutually beneficial. In addition to complementing prenatal diagnosis, postmortem examination is of vital importance for the quality control of ultrasonography in fetal diagnosis and plays an important role in genetic counseling.
Diagnosis of a fetal mesoblastic nephroma by 3D‐ultrasound
Authors: Schild R. L. , Plath H. , Hofstaetter C. , Hansmann M.
Published: March 2003

We report a case of a fetal renal tumor detected prenatally on 3D‐ultrasound. As the lesion was well encapsulated the initial sonographic diagnosis was that of a nephroblastoma. Volume calculation by the 3D technique gave a reliable estimation of the tumor size. Contrary to all published case reports concerning antenatally diagnosed mesoblastic nephromas, there was no polyhydramnios. Elective delivery was performed by Cesarean section at 38+ weeks gestation. The neonate underwent left nephrectomy on the second day of life. The subsequent course was uneventful without recurrence of the tumor. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
Determination of the anatomical location of an antenatal intestinal occlusion by magnetic resonance imaging
Authors: Benachi A. , Sonigo P. , Jouannic J.‐M. , Simon I. , Révillon Y. , Brunelle F. , Dumez Y.
Published: March 2003

Intestinal occlusion occurs in approximately 1 in 3000 births. Its diagnosis can be made in utero with ultrasound however, determination of its precise location is difficult to achieve. We report herein the feasibility of diagnosing and locating a fetal small‐intestine occlusion with the use of magnetic resonance imaging. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Quantification of fetal power Doppler: determination of the intravascular standardization point
Authors: Welsh A. W. , Rubin J. , Fowlkes B. , Fisk N. M.
Published: March 2003

Background:  With its sensitivity to low flow, lack of aliasing and relative angle independence, power (amplitude) Doppler ultrasound is well suited to assessment of tissue perfusion. However, the influence of machine settings, depth and other factors related to attenuation means that perfusion measurements taken from deep tissue without standardization to 100% flow are relatively meaningless. Previously published adult research has proposed a technique to estimate a true value for 100% amplitude from a cumulative power distribution across a large local vessel. This standardization value allows measurement of fractional moving vascular volume as an ultrasound index of perfusion.

Methods:  Fetal renal and aortic blood flow was evaluated using the power Doppler mode of the Acuson Sequoia™. Color flow information was digitally segmented to a linear 8‐bit scale and analyzed using CQ Analysis software as previously reported by our group. Using images from the fetal aorta with and without the kidney, of both segmented and unsegmented images, an attempt was made to plot the cumulative power distribution in eight fetuses (27–37 weeks' gestation). Fetal aortic amplitude information was then examined using a combination of CQ Analysis, Scion Image and Excel software. Peak amplitude was examined between different ultrasound clips in a single fetus and in 50 frames through the cardiac cycle in 10 fetuses. Spatial variation in peak aortic amplitude was examined in 50 frames from four fetuses with varying angle of insonation from 73° to 88°. Temporal variation was examined in 50 frames from a single fetus.

Results:  In the human fetus, there is no peak vascular value or corresponding ‘knee point’ attributable to the effects of rouleaux. In contrast, the peak aortic value is relatively constant for 100% flow, both between multiple imaging clips and throughout the cardiac cycle in the 10 fetuses. Spatial variation for the 100% flow value increased from an average coefficient of variation of 6.5% at 79° to 28% at 89°. Temporal variation was 8% over 50 frames.

Conclusions:  The human fetus has a reduced degree of rouleaux formation in part due to an altered form of fibrinogen and reduced concentration of plasma proteins, so the peak amplitude measurement in the center of large vessels represents true 100% flow. This finding is confirmed by the lack of cardiac cycle effects on the amplitude profile. The central value of larger blood vessels, such as the fetal aorta, if measured at an appropriate angle of insonation, may provide a relatively constant standardization value for vessels or regions at a similar depth. From these, true measurements of fractional moving vascular volume may be derived.

Acknowledgements:  Alec Welsh was supported by a Research Training Fellowship from RCOG/WellBeing, the BUPA Research Foundation Clinical Scientist Award 2000 and the 2001 Bernhard Baron/RCOG Travelling Scholarship.
Review: Glial lineages and myelination in the central nervous system
Authors: COMPSTON ALASTAIR , ZAJICEK JOHN , SUSSMAN JON , WEBB ANNA , HALL GILLIAN , MUIR DAVID , SHAW CHRISTOPHER , WOOD ANDREW , SCOLDING NEIL
Published: March 2003

Oligodendrocytes, derived from stem cell precursors which arise in subventricular zones of the developing central nervous system, have as their specialist role the synthesis and maintenance of myelin. Astrocytes contribute to the cellular architecture of the central nervous system and act as a source of growth factors and cytokines; microglia are bone‐marrow derived macrophages which function as primary immunocompetent cells in the central nervous system. Myelination depends on the establishment of stable relationships between each differentiated oligodendrocyte and short segments of several neighbouring axons. There is growing evidence, especially from studies of glial cell implantation, that oligodendrocyte precursors persist in the adult nervous system and provide a limited capacity for the restoration of structure and function in myelinated pathways damaged by injury or disease.
Quantitative analysis of the anatomy of the epineurium of the canine recurrent laryngeal nerve
Authors: BARKMEIER JULIE M. , LUSCHEI ERICH S.
Published: March 2003

The purpose of this investigation was to determine the amount of epineurium surrounding the recurrent laryngeal nerve (RLN) compared with a limb nerve, that to flexor hallicus longus (NFHL). Nerve samples were obtained from 10 adult dogs and studied using scanning electron microscopy and light microscopy to measure the relative proportion of epineurium and the relative proportions of adipose and collagenous tissue comprising the epineurium in both nerves. Significantly greater relative epineurial cross‐sectional areas and adipose content were found in the RLN than in the NFHL. Based on observations on noncranial peripheral nerves, the findings indicate that the RLN is better protected against deformational forces associated with compression than stretching forces. The RLN may not be structured well for successful reinnervation after injury. The patterns observed for adipose tissue in RLN epineurial tissue appeared unique compared with those previously reported in peripheral nerves. The primary role associated with adipose tissue is to ‘package’ the nerve for protection. The RLN is considered to be a vital nerve in the body, as are other cranial nerves. The large proportions of adipose tissue in the epineurium may relate to the importance of protecting this nerve from injury.
Structure of the human tibialis anterior tendon
Authors: PETERSEN WOLF , STEIN VOLKER , BOBKA TIMM
Published: March 2003

The structure and vascular pattern of the human tibialis anterior tendon was investigated using injection techniques, light and transmission electron microscopy and immunohistochemistry. From the well vascularised peritenon, blood vessels penetrate the tendon tissue and anastomose with a longitudinally oriented intratendinous network. The distribution of blood vessels within the tibialis anterior tendon was not homogenous. The posterior part of the tendon had a complete vascular network that extends from the musculotendinous junction to the insertion at the first metatarsal and medial cuneiform bones. In the anterior half, the tissue was avascular in a zone with a length of 45–67 mm. This zone was covered by a single layer (∼30 μm) of oval shaped cells. Transmission electron microscopy showed that these cells have the characteristics of chondroid cells. This region was stained by Alcian blue at pH 1 which indicates a high concentration of acid glycosaminoglycans and immunohistochemical staining for chondroitin‐4‐sulphate, chondroitin‐6‐sulphate and aggrecan was positive. However, immunostaining for the typical cartilage specific type II collagen within this zone was negative. The location of the avascular zone corresponds to the region where the tibialis anterior tendon wraps around the superior and inferior retinacula which serve as fibrous pulleys. This is the region where most spontaneous ruptures of the tibialis anterior tendon occur. The presence of fibrocartilage within gliding tendons is a functional adaptation to compressive and shearing forces. In contrast to reports from the literature about the structure of gliding tendons wrapping around a bony pulley, the gliding zone of the tibialis anterior tendon has only a narrow layer of chondroid cells and proof of type II collagen is lacking.
Endothelial phenotype of the materno–fetal barrier
Authors: Leach L. , Babawale M. O. , Lammiman M. J. , Dye J. F. , Clark P. , Firth J. A.
Published: March 2003

The terminal villous capillaries of the human placenta are the sites of maximal materno‐fetal exchange. These capillaries are highly angiogenic and are formed in the last trimester of pregnancy by looped angiogenesis from existing microvessels in the intermediate villi. They represent an ‘activated’ phenotype by possessing adherens junctions which contain VE‐cadherin (– and (– catenin but lack plakoglobin, the component of well differentiated junctions. The tight junctions present here show negative immunoreactivity to occludin and claudin‐1. The conduit vessels further upstream in the stem villi have the full complement of adherens and tight junctional molecules. VEGF and angiopoietin‐2 is present in terminal villi whilst angiopoietin‐1 appears to be a predominant feature of stem villi. The phenotype of junctions present in nascent vessels of the first trimester placentae was similar to the angiogenic terminal villous capillaries. The predominant growth factor here was VEGF, localised to all villi. Isolation of endothelial cells from last trimester placenta microvessels (HPMEC) demonstrated that these cells are capable of differential expression and dynamic regulation of cell‐cell junctions. Cells grown in the presence of ECGS showed a reduction in the level and junctional localisation of plakoglobin and occludin, with associated increased permeability to macromolecules. These adhesion molecules were up‐regulated and targeted back to cell‐cell contact regions by growing HPMEC in the presence of cAMP enhancing agents. This resulted in a 1.7 times increase in transendothelial resistance whilst proliferation of HPMEC cells was inhibited by elevated cAMP. HUVEC cells isolated from the umbilical cords of these placentae contain the full repertoire of AJ molecules in normal culture conditions with no change in composition or resistance under elevated cAMP. The differential expression of junctional adhesion molecules along the placental vascular tree and their in vitro plasticity suggests there is a physiological relevance of junctional regulation in the placenta. The activated junctional phenotype of the newly formed terminal microvessels allows them to participate in increased growth, proliferation and solute exchange in the last trimester when fetal demand is at its greatest. Furthemore, this necessary junctional immaturity of new/angiogenic human vessels appear to be at the expense of barrier function.

Funded by the Wellcome Trust.
Intracellular signalling involved in modulating human endothelial barrier function
Authors: Van Hinsbergh V. W. M. , Van Nieuw Amerongen G. P.
Published: March 2003

The endothelium actively regulates the extravasation of solutes, hormones and macromolecules. In pathological conditions endothelial hyperpermeability can be induced by vasoactive agents that induce tiny leakage sites between the cells, and by cytokines, in particular vascular endothelial growth factor, that increase exchange of plasma proteins by vesicles and intracellular pores. It is generally believed that the interaction of actin and nonmuscle myosin in the periphery of the endothelial cell is required for endothelial hyperpermeability induced by vasoactive agents. Histamine causes a transient increase in endothelial permeability which normalises within seversal minutes. By H1‐receptor activation it raises the cytoplasmic Ca2+ concentration and stimulates the Ca2+/calmodulin dependent activation of the myosin light chain (MLC) kinase. The phophorylated MLC promotes actin‐non–muscle–myosin interaction in the endothelial cell. Thrombin induces a prolonged hyperpermeability in human endothelial monolayers. In addition to the Ca2± dependent activation of MLC kinase, a sensitisation of the cell occurs by activation of RhoA and Rho kinase. Furthermore, protein tyrosine kinase activity contributes to the thrombin‐induced hyperpermeability.

In most types of endothelia the barrier function of endothelial cells is improved both in vivo and in vitro by agents that increase the cellular cyclic AMP concentration. Catecholamines contribute to the enforcement of the endothelial barrier function by activation of (2‐adrenergic receptors and increasing the endothelial cyclic AMP content. Nitric oxide and cyclic GMP can also counteract thrombin‐induced endothelial hyperpermeability in specific types of vessels while in other types they contribute to endothelial hyperpermeability. In human aorta endothelial cells NO induced by vasoactive agents increases the generation of cGMP, which activates cGMP‐dependent protein kinase‐I. This activity counteracts the effect on endothelial permeability by reducing the elevation of Ca2+ in the cell. Furthermore inhibitors of RhoA formation and Rho kinase represent a potentially valuable additional group of agents with endothelial hyperpermeability reducing properties. They not only reduce thrombin‐induced endothelial permeability in vitro but also reduced the interaction of leukocytes with the endothelial cells and accompanying vascular leakage in vivo.
Extracellular matrix, junctional integrity and matrix metalloproteinase interactions
Authors: Alexander J. S.
Published: March 2003

The vascular endothelial solute barrier is formed by the regulated apposition of adherens and tight junctional proteins, and is controlled by several pharmacological and physiological mediators which govern junctional organization. We observe that barrier changes in vitro are associated with (1) the spatial redistribution of surface cadherins and occludin; (2) stabilisation of focal adhesive bonds; and (3) the progressive activation of matrix metalloproteinases. In response to peroxide, histamine and EDTA, endothelial cells sequester VE‐cadherin and alter its cytoskeletal binding. At the same time these mediators also enhance focal adhesion to the substratum. Lastly oxidants, cytokines and pharmacological mediators also trigger the activation of matrix metalloproteinases in a cytoskeleton and tyrosine phosphorylation dependent manner to degrade occludin, a tight junction element. These related in vitro phenomena may act cooperatively in inflammation to structurally stabilise cells during permeability, while remodelling cell junctions and substratum.

Supported by grants HL47615, DK43785.
Taurine reduces high glucose induced leukocyte–endothelial interactions via down‐regulation of ICAM‐1
Authors: Casey R. G. , Chen G. , Joyce M. , Kelly C. J. , Bouchier‐Hayes D. J.
Published: March 2003

Taurine is a semiessential amino acid and naturally occurring antioxidant. One of its main roles is to protect tissues against attack by chlorinated oxidants particularly hypochlorous acid (HOCl). It is found in high concentrations in neutrophils and previous studies showed it possesses potent antimicrobial properties and attenuates high glucose induced endothelial cell apoptosis. In humans taurine has been shown to up‐regulate constitutive nitric oxide synthase (cNOS), a known cytoprotector.

No reported studies to date have looked at the possible therapeutic role of taurine in preventing diabetic endothelial dysfunction. We therefore hypothesised that taurine would attenuate the microvascular changes associated with hyperglycaemia in an animal model through alteration of leucocyte–endothelial interactions.

Male Sprague Dawley rats were randomised into control, hyperglycaemia, and taurine + hyperglycaemia groups. Taurine was gavaged (200 mg/kg) for 5 d prior to the experiment. Hyperglycaemia was established by intravenous infusion of 50% glucose. Blood glucose reached a steady state of 3 times baseline at 30 min. Using intravital microscopy leukocyte rolling, adhesion and transendothelial migration was determined in mesenteric postcapillary venules for 3 h. Intracellular adhesion molecule‐1 (ICAM‐1) was immunohistochemically graded using a scoring system to determine the expression in mesenteric tissue.

Taurine pretreatment significantly attenuates leukocyte‐endothelial adhesion and transendothelial migration following acute hyperglycaemia but not leukocyte rolling velocity. The mechanism by which taurine protects against these effects is in part by inhibition of ICAM‐1 expression.

Results at 120 min (n = 5/group)
Control
Hyperglycaemia
Taurine + Hyperglycaemia

Leukocyte rolling

velocity (m/s)
49.5 (4.5)
30.4 (6.4)
45.4 (5.5)

Leukocyte

adhesion (/100(m))
 2.25 (1.70)*
44.0 (10.5)
 9.25 (2.3)*

Transendothelial

migration (/field)
 6.5 (1.3)*
76.8 (20.7)
12.25 (5.9)*

Expression of

ICAM‐1 (at 180 mins)
 1.05 (0.40)*
 2.9 (0.4)
 1.1 (0.3)*

Data are expressed as mean (SEM). Analysis with anova and post Scheffe hoc test.

*P < 0.05 vs. Hyperglycaemia.
Electrophysiological study of the rectosigmoid canal: evidence of a rectosigmoid sphincter
Authors: Shafik Ahmed , Mostafa Randa M. , Shafik Ali A.
Published: March 2003

Previous studies strongly suggest the presence of a sphincter at the rectosigmoid junction, an area with a mean length of 2.8 cm in adults, called the rectosigmoid canal (RSC). To find supporting evidence of a sphincteric function for the RSC, two recording electrodes were applied to each of the sigmoid colon (SC), RSC and rectum (R) in 11 subjects during operative repair of huge incisional hernias. The RSC, SC and R were individually stimulated by a further electrode and their pressures monitored by a three‐channel microtip catheter. The variables of the slow waves or pacesetter potentials, recorded at rest from the RSC and R, were significantly higher than those of the SC. While the frequency and conduction velocity of pacesetter potentials of the RSC and R were similar, the potential pacesetter amplitude of the RSC was significantly higher. The increase of the electrical activity and pressure upon electrostimulation was significantly greater in the RSC than that of the SC or R. Electrostimulation led to an increase in pressure of all three areas, the RSC increase being significantly the greatest. The greater increase of the electrical activity and pressure of the rectosigmoid canal upon electrostimulation, compared to that of the SC or R, strongly supports the presence of a rectosigmoid sphincter.
The functional anatomy of the human anterior talofibular ligament in relation to ankle sprains
Authors: Kumai T. , Takakura Y. , Rufai A. , Milz S. , Benjamin M.
Published: March 2003

The anterior talofibular ligament is the most commonly injured ligament in the ankle. Despite considerable interest in the clinical outcome of treatment protocols, we do not know whether the distinctive pattern of localization of the injuries relates to regional differences in the structure and molecular composition of the ligament. To address this issue, ligaments were examined by histology and immunohistochemistry. Differences in the structure of its two attachments (i.e. entheses) were evaluated with quantitative, morphometric techniques, and regional differences in the distribution of collagens, glycosaminoglycans and proteoglycans were determined qualitatively by immunolabelling. Morphometric analyses showed that bone density was less at the fibular attachment, but that enthesis fibrocartilage was more prominent. Immunohistochemistry revealed the presence of a fibrocartilage (containing type II collagen and aggrecan) at the site where the ligament wraps around the lateral talar articular cartilage in a plantarflexed and inverted foot: the fibrocartilage is regarded as an adaptation to resisting compression. We propose that avulsion fractures are less common at the talar end of the ligament because (1) bone density is greater here than at the fibular enthesis, and (2) stress is dissipated away from the talar enthesis by the ‘wrap‐around’ fibrocartilaginous character of the ligament near the talar articular facet.
Expression of parathyroid hormone‐related peptide (PTHrP) and its receptor (PTH1R) during the histogenesis of cartilage and bone in the chicken mandibular process
Authors: Zhao Qiong , Brauer Philip R. , Xiao Lei , McGuire Michael H. , Yee John A.
Published: March 2003

The purpose of this study was to examine the expression and actions of parathyroid hormone‐related protein (PTHrP) when skeletal histogenesis occurs in the chicken mandible. Prior to the appearance of skeletal tissues, PTHrP and PTH1R were co‐expressed by cells in the ectoderm, skeletal muscle, peripheral nerve and mesenchyme. Hyaline cartilage was first observed at HH stage 27 when many but not all chondroblasts expressed PTHrP and PTH1R. By stage 34, PTHrP and PTH1R were not detected in chondrocytes but were expressed in the perichondrium. Alkaline phosphatase (AP)‐positive preosteoblasts and woven bone appeared at stages 31 and 34, respectively. Preosteoblasts, osteoblasts and osteocytes co‐expressed PTHrP and PTH1R. Treatment with chicken PTHrP (1–36) increased cAMP in mesenchyme from stage 26 embryos. Continuous exposure to chicken PTHrP (1–36) for 14 days increased cartilage nodule number and decreased AP while intermittent exposure did not affect cartilage nodule number and increased AP in cultures of stage 26 mesenchymal cells. Adding a neutralizing anti‐PTHrP antibody to the cultures reduced cartilage nodule number and did not affect AP. These findings show that PTHrP and PTH1R are co‐expressed by extraskeletal and skeletal cells before and during skeletal tissue histogenesis, and that PTHrP may influence skeletal tissue histogenesis by affecting the differentiation of mandibular mesenchymal cells into chondroblasts and osteoblasts.
Ultrastructure of the placenta of the tammar wallaby, Macropus eugenii: comparison with the grey short‐tailed opossum, Monodelphis domestica
Authors: Freyer Claudia , Zeller Ulrich , Renfree Marilyn B.
Published: March 2003

The ultrastructure of the tammar placenta was studied throughout pregnancy. The uterine epithelium grows from a columnar to an enlarged, undulating epithelium between early gestation and mid‐gestation when the shell coat that surrounds the marsupial conceptus ruptures. Trophectoderm and uterine epithelium do not form syncytia, nor does invasion of the endometrium occur at any stage of pregnancy. Uterine secretion is provided to both the bilaminar and the trilaminar side of the yolk sac placenta up to birth. Fenestrations, abundant vesicles and lumenal processes of maternal capillaries, as well as deep basal folds of the uterine epithelium, suggest that there is transfer of hemotrophes adjacent to both parts of the yolk sac. In contrast, in the grey short‐tailed opossum, these structures are lacking. The yolk sacs of adjacent embryos fuse to form a common yolk sac cavity, thus losing most of the bilaminar yolk sac. The bilaminar and trilaminar components of the yolk sac placenta of the tammar are less different in structure and function than those of the grey short‐tailed opossum, but both types are fully functional placentas. The extended secretory phase of the tammar uterus and the maternal recognition of early pregnancy appear to be derived characters of macropodid marsupials.
Magnetic resonance imaging of the rat Harderian gland
Authors: Sbarbati Andrea , Calderan Laura , Nicolato Elena , Marzola Pasquina , Lunati Ernesto , Donatella Benati , Bernardi Paolo , Osculati Francesco
Published: March 2003

The intra‐orbital lachrymal gland (Harderian gland, or HG) of the female rat was studied by magnetic resonance imaging (MRI) to evaluate whether MRI can be used to visualize the gland in vivo and localized‐1H‐spectroscopy detect its lipid content. The results were correlated with post‐mortem anatomical sections, and with light and electron microscopy. On MRI, HG presented as a mass located between the ocular bulb and the orbit. In strongly T2W sequences the secretory structures had a reduced signal while intraparenchymal connective tissue was visible. T2‐quantitative maps values of HG (60.12 ± 8.15 ms, mean ± SD) were different from other tissues (i.e. muscular tissue, T2 = 44.79 ± 3.43 ms and olfactory bulb, T2 = 79.26 ± 4.25 ms). In contrast‐enhanced‐MRI, HG had a signal‐intensity‐drop of 0.074 ± 0.072 (mean ± SD), after injection of AMI‐25, significantly different from the muscle (0.17 ± 0.10). Localized MRI spectra gave a large part of the signal originating from fat protons, but with a significant percentage from water protons. At light and electron microscopy the lipid deposition appeared to be composed of low‐density material filling a large part of the cytoplasm, and the porphyrin aggregates were easily recognizable. The data demonstrate that an in vivo study of the HG was feasible and that high‐field MRI allowed analysis of the gross anatomy detecting the lipid content of the gland.
Covering the limb – formation of the integument
Authors: Byrne Carolyn , Hardman Matthew , Nield Kerry
Published: March 2003

An organism's outermost covering, the integument, has evolved to fulfil a diverse range of functions. Skin provides a physical barrier, an environment for immunological surveillance, and also performs a range of sensory, thermoregulatory and biosynthetic functions. Examination of the skin of limb digits reveals a range of skin types including the thickened hairless epidermis of the toe pads (palmar or plantar epidermis) and thinner epidermis between the hair follicles (interfollicular epidermis) of hairy skin. An important developmental function of skin is to give rise to a diverse group of appendages including hair follicles, with associated sebaceous glands (or feathers and scales in chick), eccrine sweat glands and the nail. A key question is how does this morphological variety arise from the single‐layered epithelium covering embryonic limb buds? This review will attempt to address this question by linking the extensive morphological/anatomical data on maturation of epidermis and its appendages with (1) current research into the range, plasticity and location of the putative epidermal stems cells; (2) molecular/microenvironmental regulation of epidermal stem cell lineages and lineage choice; and (3) regulation of the differentiation pathways, focusing on differentiation of the interfollicular epidermis.
Is sclerophylly of Mediterranean evergreens an adaptation to drought?
Authors: SALLEO S. , NARDINI A. , LO GULLO M. A.
Published: March 2003

The potential role of sclerophylly (leaf hardness and rigidity) in the control of leaf dehydration and rehydration was investigated in two sclerophylls (Viburnum tinus and Ilex aquifolium) and two non‐sclerophylls (Hedera helix ssp. helix and Sambucus nigra). After leaves were dehydrated in the pressure chamber, water transport from the apoplast (mainly consisting of xylem conduits and mechanical cells) to symplast was detected 15 min from pressure release, in terms of a spontaneous increase in leaf water potential (ϕ1). This ϕ1 increase was much larger in sclerophylls than in non‐sclerophylls.

Positive pressures applied to leaves simulated the tensions developing in the leaf apoplast under water stress conditions, causing water to be expelled from leaf xylem conduits and mechanical cells and transferred to the leaf symplast, thus leading to symplast rehydration and to the consequent ϕ1 increase.

No correlation was found between the leaf modulus of elasticity at full turgor or the degree of sclerophylly (in terms of the ratio of leaf d. wt to surface area) and the characteristic rehydration time of the leaves, i.e. between the two main parameters expressing the rigidity of the leaf blade and the rate of leaf rehydration. However, when changes in ϕ1 were measured as a function of leaf water deficit (RWD), equal ϕ1s corresponded with larger RWDs during leaf rehydration than during leaf dehydration in the two non‐sclerophylls. In particular, the two sclerophylls showed rehydration of their leaf apoplast and symplast completely and simultaneously. By contrast, the two non‐sclerophylls showed a persisting water loss, localized, it is likely, in their xylem conduits and mechanical cells.

In other words, the two sclerophylls did not recover from water loss more rapidly than non‐sclerophylls but they recovered from xylem cavitation more completely. The major elasticity of the cavitation strain shown by the two sclerophylls studied was interpreted as of advantage to plants subjected to diurnal large drops in ϕ1 followed by nocturnal recovery. This is the case in Mediterranean sclerophylls growing in areas characterized by high humidity of the air condensing on the soil at night. The same mechanism of cavitation recovery, however, would be useless in very xeric areas.

The hypothesis is advanced that sclerophylly of Mediterranean species may derive from similar anatomical structures developed in species formerly adapted to more humid environments which later migrated to more arid zones.
Components of pathozone behaviour
Authors: GILLIGAN C. A. , BAILEY D. J.
Published: March 2003

Pathozone behaviour of soil‐borne plant pathogenic fungi is characterized by curves for the change in probability of infection with distance of inoculum from a host. We identify three major components that give rise to the pathozone profile for infection efficiency: the germinability of inoculum, given that it occurs in the pathozone (P1), the growth of the resulting fungal colony outwards to make contact with the host (P2), and the infectivity of mycelium once contact is made (P3). The probability of infection (P) is then given by the product, P1×P2×P3. Using Raphanus sativus and two contrasting types of inoculum of Rhizoctonia solani as a model experimental system, we measured each of the three components by quantifying germinability, colony architecture (to determine the chance of contact by one or more hyphae) and the change in susceptibility over time as a measure of infectivity as mycelium arrives from different distances away. The germinability of inoculum is uniform across the pathozone whereas the probability of contact declines with distance, and the net effect of host susceptibility and infectivity increases. The characteristics of these components result in pathozone profiles that vary in shape. Infection efficiency can decline in an exponential or sigmoidal fashion with increasing distance from the host or follow a curve that rises close to the host and then falls asymptotically to zero with increasing distance. Colony architecture was summarized by the distribution of the furthest extent of hyphal growth amongst colonies growing out from single inoculum units (described, because of its asymmetrical pattern, by a gamma distribution) and by the radial density of hyphae on concentric circles at different distances from the centre of the colony (described by a negative binomial distribution with parameters changing with distance).

The mechanistic model for the components of pathozone behaviour is tested by comparing the magnitude and shape of pathozone profiles predicted by the model with independent estimates for P obtained by placing inoculum at fixed distances from the host, and measuring the proportion of successful infections. The shape depends on the relative magnitudes and change with distance of the three components, P1, P2 and P3, which differed between the two types of inoculum. The profiles could be reproduced accurately when the probability of contact was based on the distribution and density of hyphae reaching the host rather than on the furthest extent of hyphal growth amongst colonies. The model is used to analyse the effects of replication and stochastic variability in the components of pathozone behaviour on the comparison of treatments for disease control.
Cyclic AMP, a possible regulator of glycolysis in the ectomycorrhizal fungus Amanita muscaria
Authors: HOFFMANN E. , WALLENDA T. , SCHAEFFER C. , HAMPP R.
Published: March 2003

summary

The amounts of cyclic AMP (cAMP), fructose‐2,6‐bisphosphate (F26BP), trehalose and glycogen were determined in cell suspension cultures of the ectomycorrhiza‐forming fungus Amanita muscaria (L. ex Fr.) Hooker. For the assay of cAMF a protocol was developed that enabled the detection of as little as 50 fmol of this secondary messenger by an enzyme‐linked immuno assay (EIA). Values varied from < 1 and up to 5 pmol cAMP mg1d. wt according to the age of the fungal culture. Typically, a transient increase in cAMP occurred after c. 4 d of culture of the fungus on glucose‐containing medium. This increase (up to 100%) was followed by the start of the logarithmic growth phase, and by a more persistent increase in F26BP. In parallel, glucose in the medium started to decrease, whilst the amounts of fungal carbohydrates, especially the disaccharide trehalose, increased, From these data we assume that a high initial rate of glucose uptake caused an increase in the fungal pools of storage carbohydrates and, via activation of an adenylate cyclase, of cAMP. According to data reported for yeast cells this should enhance the formation of F26BP by phosphorylation of relevant enzymes. In animal and yeast cells an increase in the concentration of F26BP stimulates glycolysis by activation of the ATP‐dependent phosphofructokinase (PFK). A. muscaria also possesses an F26BP activated PFK and, under conditions of symbiosis, host‐derived carbohydrates are supplied mainly in the form of glucose. The implications of these findings to the regulation of carbohydrate metabolism of symbiotic plant root/fungus structures (ectomycorrhiza) are discussed.
B chromosomes: a physiological enigma
Authors: BOUGOURD SUSAN M. , JONES R. NEIL
Published: March 2003

summary

The concept of the ‘nucleotype’ embraces aspects of the nuclear DNA that affect the phenotype other than through the coding sequences. In this context, we consider one particular situation, namely DNA variation due to the presence of supernumerary B chromosomes (Bs); these Bs, which are additional to the basic complement of A chromosomes, generate a spectrum of DNA amounts, and thus nucleotypes, within many species. We consider the physiological consequences of carrying extra chromosomes that appear by and large to lack coding sequences, and focus on two species with contrasting case histories: rye (Secale cereale L.) and chives (Allium schoenoprasum L.), which illustrate ‘selfish’ and ‘adaptive’ explanations of the persistence of B chromosomes.