bluuebunny/crossref_metadata_2025_split huggingface dataset:
Volumetric Bone Mineral Density in Young Women with Turner’s Syndrome Treated with Estrogens or Estrogens plus Growth Hormone
Authors: Bertelloni Silvano , Cinquanta Luisa , Baroncelli Giampiero I. , Simi Paolo , Rossi Simona , Saggese Giuseppe 
Published: April 2003

To explore the effects of estrogen replacement therapy (ERT) and recombinant growth hormone (GH) treatment on bone mineral density (BMD) in Turner’s syndrome, we assessed volumetric BMD (vBMD), which is less dependent on body and bone sizes, in these patients at final height. The areal BMD (aBMD) was measured in 26 young women with Turner’s syndrome (age range 17.5–25.0 years) by dual-energy X-ray absorptiometry, and vBMD was calculated. Patients were subdivided as group 1 (n = 12; ERT alone) and group 2 (n = 14; GH + ERT). Years of estrogen exposure were not different between the groups (group 1: 6.4 ± 1.5 years; group 2: 5.3 ± 1.7 years); in group 2, GH therapy was 5.3 ± 1.4 years. Final heights were significantly higher in group 2 than in group 1 (148.1 ± 3.0 vs. 142.0 ± 2.8 cm; p < 0.0001) as well as aBMD (1.073 ± 0.118 vs. 0.968 ± 0.122 g/cm<sup>2</sup>; p < 0.04). vBMD was higher in group 2 but not significantly different from group 1 (0.374 ± 0.030 vs. 0.358 ± 0.027 g/cm<sup>3</sup>; p = 0.169). aBMD was reduced with respect to the normative values in both groups (group 1: –1.97 ± 1.04 SDS, p < 0.0001 vs. 0; group 2: –0.93 ± 1.01 SDS, p < 0.005 vs. 0), whereas vBMD was not (group 1: –0.07 ± 0.79 SDS; group 2: 0.42 ± 0.82 SDS). Our data suggest that: in Turner’s syndrome GH administration improves final height and aBMD, but it does not significantly increase vBMD; aBMD reduction in Turner’s syndrome is likely due to the impaired growth and reduced bone size; Turner’s patients on ERT from adolescence show vBMD values in the normal range in young adulthood.
Thickened Pituitary Stalk on Magnetic Resonance Imaging in Children with Central Diabetes insipidus
Authors: Czernichow Paul , Garel Catherine , Léger Juliane 
Published: April 2003

Magnetic resonance imaging (MRI) has revealed isolated pituitary stalk thickening (PST) in certain cases of idiopathic or secondary central diabetes insipidus (DI) due to infiltrative processes. Twenty-six children with DI and PST underwent cerebral MRI at the age of 8 ± 4 years and were followed (n = 25) by clinical and MRI evaluation for 5.5 ± 3.6 and 3.0 ± 2 years, respectively, but given no treatment other than hormonal substitutive therapy. Patients were subdivided into groups according to the etiology of the DI: germinoma (n = 4), Langerhans’ histiocytosis (n = 5) or ‘idiopathic’ DI with PST (n = 17). Complete anterior pituitary evaluation in 24 of the 26 patients revealed that 14 children were suffering from associated growth hormone deficiency and 7 had multiple hormone deficiencies. At the first MRI evaluation, pituitary stalk enlargement varied from 2.2 to 9.0 mm. The anterior pituitary gland was found to be normal (n = 12), small (n = 8) or enlarged (n = 6). At the final evaluation, a change in MRI features had occurred in 16 patients: morphological and/or signal changes in the PST (n = 16; 6 of whom showed an increase in PST) and changes in anterior pituitary gland size (n = 8; 3 of whom had increased and 5 had decreased). The presence of a growing suprasellar mass with a progressively enlarging pituitary stalk was demonstrated in the 6 patients who had shown increased pituitary stalk enlargement 1.8 ± 1.6 years after the first MRI. In 4 of these patients, a diagnosis of germinoma was made 1.3 ± 0.6 years after PST identification by MRI at the onset of DI, but the other 2 patients showing a suprasellar mass were still categorized as ‘idiopathic’ at the final clinical evaluation performed 7.8 and 12.3 years after DI onset. In 10 patients (all but 1 with Langerhans’ histiocytosis, showing ‘idiopathic’ DI) the pituitary stalk enlargement was diminished after 2.0 ± 1.9 years of MRI follow-up, and there was a complete reversal of pituitary stalk enlargement in 5 patients. We conclude that the natural history of ‘idiopathic’ isolated central DI with PST is unpredictable. Although germinoma should always be considered during the first 3 years of follow-up in patients presenting isolated DI with PST by repeated investigations every 3–6 months, it remains an infrequent etiology, affecting only 15% of cases in our study.
Antenatal and Early Postnatal Dexamethasone Treatment Decreases Cortisol Secretion in Preterm Infants
Authors: Karlsson Riikka , Kallio Jaana , Toppari Jorma , Scheinin Mika , Kero Pentti 
Published: April 2003

Glucocorticoids are used antenatally to accelerate the maturation of fetal respiratory and cardiovascular systems when a threat of preterm delivery exists. Postnatally, they are used to prevent and treat respiratory distress syndrome. This study investigates the effects of antenatal (ACT) and early postnatal corticosteroid treatment (PCT) on serum cortisol and plasma catecholamine and adenosine 3′,5′-cyclic monophosphate (cAMP) concentrations in preterm neonates. The infants in the ACT group had a significantly lower cortisol concentration than the infants in the non-ACT group on the first day of life. After birth, the infants were further divided into non-PCT and PCT groups. PCT suppressed cortisol levels significantly after 2 days, and the cortisol levels were still lower 2 days after discontinuation of PCT. No effect of PCT on plasma cAMP or catecholamine concentrations was observed. The results indicate that both ACT and a short PCT can significantly suppress basal cortisol levels in preterm infants.
Remodelling and Enhanced Myogenic Tone in Cerebral Resistance Arteries Isolated from Genetically Hypertensive Brattleboro Rats
Authors: Dunn William R. , Wallis Sarah J. , Gardiner Sheila M. 
Published: April 2003

In this study, we examined the structural and functional properties of cerebral resistance arteries isolated from normotensive (Di/N), and hypertensive (Di/H), vasopressin-deficient rats. Di/H rats had a significantly higher mean arterial blood pressure (MAP, 159 ± 3 mm Hg) than Di/N rats (125 ± 2 mm Hg). Vessels were set up in a pressure myograph, and the internal diameter and wall thickness were determined at increasing intraluminal pressures under passive (calcium-free) conditions. Arteries were then pressurized to the MAP of the animal, from which they were isolated and fixed with glutaraldehyde, embedded in araldite, sectioned and examined histologically. Under passive conditions, the middle cerebral artery (MCA) from Di/H rats had a smaller internal diameter than the MCA isolated from Di/N rats at all distending pressures. This smaller internal diameter of vessels from hypertensive rats is characteristic of eutrophic inward remodelling, whereby a similar amount of wall material is organized around a smaller lumen, without vascular growth or an alteration in artery distensibility. We have previously shown that similar structural alterations occur in mesenteric resistance arteries isolated from Di/H rats. In the presence of extracellular calcium (1.6 mmol/l), the MCA isolated from Di/H rats had significantly more intrinsic tone than the MCA isolated from Di/N rats in the pressure range of 10–110 mm Hg, although arteries from both strains had a similar myogenic index. The increased intrinsic constriction was a specific enhancement of pressure-induced tone, since responses to the thromboxane mimetic, U46619, were decreased, rather than increased, in the MCA isolated from Di/H rats. Furthermore, it is unlikely that the increased intrinsic tone in arteries isolated from Di/H rats was due to an impaired endothelial function since responses to the endothelium-dependent vasodilator, bradykinin, were enhanced in these vessels compared to arteries isolated from Di/N rats.
Antihypertensive Effect of All-cis-5,8,11,14,17-Icosapentaenoate of Aged Rats Is Associated with an Increase in the Release of ATP from the Caudal Artery
Authors: Hashimoto Michio , Shinozuka Kazumasa , Shahdat Hossain M. , Kwon Young Mi , Tanabe Yoko , Kunitomo Masaru , Masumura Sumio 
Published: April 2003

Fish oils have been shown to lower blood pressure in hypertensive subjects. All-cis-5,8,11,14,17-icosapentaenoate (EPA), one of the ω–3 polyunsaturated fatty acids, is known to be one of the major active components in fish oil that has beneficial effects on the cardiovascular system. However, little is known about the antihypertensive effect of EPA alone on blood pressure. In the present study, we have determined the spontaneous and noradrenaline-evoked release of ATP, ADP, AMP, and adenosine from caudal arteries of aged (100 weeks old) Wistar rats which were fed a standard diet or a high cholesterol diet, treated with EPA. Dietary EPA administration increased plasma and caudal arterial EPA concentrations and repressed increases in blood pressure with advancing age in both aged rats with and without hypercholesterolemia. In addition, noradrenaline (1 µmol/l) evoked a significantly greater release of purines from the caudal arteries of EPA-administered aged rats compared to both sets of control rats. Regression analysis revealed a significant relationship between the total amount of purines released from the artery and blood pressure. These results suggest that administration of EPA to aged rats increases the release of ATP from the vascular endothelial cells, leading to repression of the blood pressure rise seen with advancing age.
Arteriolar Remodeling in Skeletal Muscle of Rats Exposed to Chronic Hypoxia
Authors: Price Richard J. , Skalak Thomas C. 
Published: April 2003

The topological structure of the arteriolar network is an important determinant of microvascular resistance. In several normal and pathological conditions, this network topology is remodeled such that adequate tissue perfusion and oxygenation are maintained. The objective of this study was to quantify the extent of arteriolar remodeling in skeletal muscle of rats chronically exposed to 10% oxygen for 18 ± 3.6 days. Arcade arteriolar (AA) and transverse arteriolar networks that had been immunofluorescently labeled for smooth muscle α-actin and smooth muscle myosin heavy chain were observed in whole-mount gracilis muscles from hypoxic and weight-matched control rats. Eight muscles from 4 animals were used for analysis in each group. The percentage (± SD) of terminal arteriolar endings that were positive for smooth muscle α-actin, but negative for smooth muscle myosin heavy chain increased significantly (p < 0.05) from 29.2 ± 8.0 in controls to 70.7 ± 9.0 in hypoxia, indicating that the rate of terminal arteriolar development was elevated in the hypoxic animals. The number of AA loops/muscle (± SD) increased significantly from 9.6 ± 2.3 in controls to 14.4 ± 4.6 in hypoxia. This increase in AA loops/muscle was due primarily to a large increase in the number of small-diameter (<15 µm) AA segments/muscle, suggesting that new AA loops were formed via the recent anastomosing of developing small-diameter terminal arterioles. The results demonstrate that exposure to chronic hypoxia stimulates significant remodeling of both the arcade and transverse arteriolar networks in skeletal muscle.
Blockade of Ca<sup>2+</sup>-Activated K<sup>+</sup> Channels Inhibits Proliferation of Human Endothelial Cells Induced by Basic Fibroblast Growth Factor
Authors: Wiecha Johannes , Münz Benedikt , Wu Yongjian , Noll Thomas , Tillmanns Harald , Waldecker Bernd 
Published: April 2003

Basic fibroblast growth factor (bFGF) exerts angiogenic and mitogenic properties in human tissue. Since changes in ion currents modulate essential Ca<sup>2+</sup>-dependent intracellular pathways in endothelial cells, we have investigated a possible contribution of Ca<sup>2+</sup>-activated K<sup>+</sup> channels (BK<sub>Ca</sub>) on bFGF-induced endothelial cell proliferation. The patch-clamp technique was used to identify BK<sub>Ca</sub> and to study their modulation by bFGF in cultured endothelial cells of human umbilical cord veins (HUVEC). Cell counts of HUVEC were carried out on different days to analyze bFGF-induced cell proliferation and its influence by the specific BK<sub>Ca</sub> blocker iberiotoxin (IBX). Using single-channel recordings, we found characteristic BK<sub>Ca</sub> with a single-channel slope conductance of 170.3 ± 2.1 pS (n = 7), half-maximal activation at internal pCa = 5.7 (n = 5; test potential: 80 mV), and dose-dependent block by IBX (25–100 nmol/l). In cell-attached patches bFGF (50 ng/ml) caused a significant increase in the open-state probability (NPo) after 6 min at test potentials of 80 and 100 mV (n = 28; p < 0.001), respectively, which lasted up to 30 min. After preincubation with pertussis toxin (100 ng/ml; 4 h) bFGF superfusion did not cause a significant increase in BK<sub>Ca</sub> activity until 25 min had passed (n = 20; p < 0.01). Addition of 100 nmol/l IBX to the pipette solution caused a total block of BK<sub>Ca</sub> within 2 min in cell-attached patches, whereas bFGF (50 ng/ml) was not able to activate BK<sub>Ca</sub>. When incubated with IBX (25–100 nmol/l) every 2 days, bFGF-induced proliferation of HUVEC was significantly decreased by 50 (–41%) and 100 nmol/l (–50%) IBX (n = 5; p < 0.001) after 7 days. We conclude that activation of BK<sub>Ca</sub> by bFGF may play an important role in bFGF-induced proliferation of human endothelial cells and thus might be important in the process of angiogenesis and vascular remodelling.
A New Computerized Biomechanical Perfusion Model for ex vivo Study of Fluid Mechanical Forces in Intact Conduit Vessels
Authors: Gan Li-ming , Sjögren Lena Selin , Doroudi Roya , Jern Sverker 
Published: April 2003

We have developed a new computerized biomechanical ex vivo perfusion system for intact conduit vessels in which a wide range of combinations of intraluminal pressure, fluid flow and shear stress could be set and maintained at target levels in mammalian conduit vessels under controlled metabolic conditions. Mean wall shear stress is calculated using the formula:&#964; = 1/2 * (&#916;P/L)<sup>3/4</sup> * (8&#951;Q/&#928;)<sup>1/4</sup>.Accuracy of the wall shear stress calculation was validated by ultrasonographic imaging of the vessel radius. In a series of simulation experiments, the hemodynamic homeostasis functions of the system were challenged by generating a wide range of vascular resistance in artificial vessels and by pharmacologically induced changes in vascular tone in intact human vessels. Despite rapid changes in vessel resistance, shear stress and pressure, or flow and pressure were maintained well at target levels. Shear- and pressure-stimulated production of the vasodilator prostaglandin E<sub>2</sub> (PGE<sub>2</sub>) was used to validate the biological relevance of the model. PGE<sub>2</sub> release was significantly more stimulated by high (25 dyn/cm<sup>2</sup>) compared to low (<4 dyn/cm<sup>2</sup>) shear (ANOVA, p = 0.012). High compared to low intraluminal pressure depressed the production of PGE<sub>2</sub> (ANOVA, p = 0.019). In summary, the computerized perfusion model appears to offer new possibilities of investigating the complex interplay between fluid mechanics and the vascular wall.
Static versus Dynamic Distensibility of the Carotid Artery in Humans
Authors: Lénárd Zsuzsanna , Fülöp Daniel , Visontai Zsuzsanna , Jokkel Gábor , Reneman Robert , Kollai Mark 
Published: April 2003

In clinical studies, the elastic behavior of central arteries is usually assessed by measuring dynamic distensibility. In this study, we aimed to investigate how dynamic and static distensibility of the common carotid artery (D<sub>dyn</sub> and D<sub>stat</sub>, respectively) are related in 28 healthy volunteers of 20–71 years. The carotid diameter and its change with the pressure pulse were measured using an ultrasound echo-tracking device. Arterial blood pressure was measured by Finapres and carotid pressure was determined by applanation tonometry. D<sub>dyn</sub> was determined at rest using the pressure pulse, while D<sub>stat</sub> was determined during pressor responses induced by handgrip or cold pressor test. Data are given as mean ± 1 SD. In younger subjects (<35 years), D<sub>stat</sub> did not differ from D<sub>dyn</sub> (7.0 ± 3.4 vs. 6.5 ± 2.1·10<sup>–3</sup>·mm Hg<sup>–1</sup>, respectively), whereas in older subjects (>35 years), D<sub>stat</sub> was significantly higher than D<sub>dyn</sub> (3.8 ± 1.4 vs. 2.1 ± 0.9· 10<sup>–3</sup>·mm Hg<sup>–1</sup>, p < 0.001). For all subjects, D<sub>stat</sub> and D<sub>dyn</sub> decreased with increasing age and mean arterial pressure (MAP). Using stepwise multiple regression analysis, the strongest predictor of D<sub>stat</sub> proved to be MAP, while that of D<sub>dyn</sub> was age. D<sub>stat</sub> was found to be linearly related to the hysteresis loop area of the pressure-diameter relation (r = 0.94), i.e. to vessel wall viscosity. It is concluded that, with increasing age, static distensibility overestimates the distension capacity of large arteries.
Ascorbate Transport in Pig Coronary Artery Smooth Muscle: Na<sup>+</sup> Removal and Oxidative Stress Increase Loss of Accumulated Cellular Ascorbate
Authors: Holmes Melanie E. , Samson Sue E. , Wilson John X. , Dixon S. Jeffrey , Grover Ashok K. 
Published: April 2003

Pig deendothelialized coronary artery rings and smooth muscle cells cultured from them accumulated ascorbate from medium containing Na<sup>+</sup>. The accumulated material was determined to be ascorbate using high-performance liquid chromatography. We further characterized ascorbate uptake in the cultured cells. The data fitted best with a Hill coefficient of 1 for ascorbate (K<sub>asc</sub> = 22 ± 2 μ<i>M</i>) and 2 for Na<sup>+</sup> (K<sub>Na</sub> = 84 ± 10 m<i>M</i>). The anion transport inhibitors sulfinpyrazone and 4,4′-diisothiocyanatostilbene-2,2′-disulfonate (DIDS) inhibited the uptake. Transferring cultured cells loaded with <sup>14</sup>C-ascorbate into an ascorbate-free solution resulted in a biphasic loss of radioactivity – an initial sulfinpyrazone-insensitive faster phase and a late sulfinpyrazone-sensitive slower phase. Transferring loaded cells into a Na<sup>+</sup>-free medium increased the loss in the initial phase in a sulfinpyrazone-sensitive manner, suggesting that the ascorbate transporter is bidirectional. Including peroxide or superoxide in the solution increased the loss of radioactivity. Thus, ascorbate accumulated in coronary artery smooth muscle cells by a Na<sup>+</sup>-dependent transporter was lost in an ascorbate-free solution, and the loss was increased by removing Na<sup>+</sup> from the medium or by oxidative stress.
Sonographic Features of Salivary Gland Tumours
Authors: Al-Tamami Mohi , Al-Naqeeb Nail , Kovacs Agnes , Dashti Hussein , Patrick John Madda 
Published: April 2003

<i>Objective:</i> High resolution ultrasonography (US) has played a significant role in the study of salivary gland (SG) pathology and has surpassed sialography in the study of SG tumours. This report discusses the sonographic features of SG tumours examined during the last 5 years. The value of these features as diagnostic indicators of the nature (benign or malignant) and histotype of these tumours is assessed. <i>Methods:</i> High resolution ultrasonography was used in the study of 83 cases of salivary tumours, 78 of which were of the parotid gland and 5 of the submandibular gland. Sixty-six (80%) of these tumours were benign. An US scanner with a 7.5-MHz real-time linear probe was used. The diseased SG was examined in multiple planes to fully delineate and locate the lesions and to characterize their sonographic features. <i>Results:</i> US detected and correctly located all tumours. The sonographic features of the various tumour categories studied are presented with special emphasis on diagnostically significant ones. The value of these features as diagnostic indicators of the nature (benign or malignant) and the histotype of these tumours is assessed. In this study, the rate of correct US identification of tumour benignity was 100% in a group of 15 adenolymphomas and 12 benign non-epithelial tumours, and 94% in a group of 34 pleomorphic adenomas. Five cases of recurrent pleomorphic adenoma were also studied. Correct US identification of malignancy was achieved in 82% of malignant tumours (15 carcinomas and 2 isolated primary non-Hodgkin’s lymphomas of the parotid gland). US identification of the specific tumour histotype was quite successful in the case of benign tumours with an accuracy of 84% in pleomorphic adenoma, 93% in adenolymphoma, and 100% in vascular tumours and lipoma. Only 1 of the 17 malignant tumours (a carcinomatous pleomorphic adenoma) was specifically identified. <i>Conclusion:</i> Based on the diagnostic capabilities of US revealed in this study as well as its operational advantages, US is strongly recommended as the first-line imaging procedure for all masses at the SG regions, to be followed by US-guided fine needle aspiration biopsy particularly for equivocal cases.
A Brief Cognitive Screening Battery for Dementia in the Community
Authors: Belle Steven H. , Mendelsohn Aaron B. , Seaberg Eric C. , Ratcliff Graham 
Published: April 2003

Screening community samples for dementia often necessitates administering a cognitive test battery by trained personnel. Because diagnostic examinations are expensive, a useful screening battery must be highly specific in addition to having high sensitivity. The Monogahela Valley Independent Elders Survey (MoVIES) includes a random sample of community-dwelling participants at least 65 years of age who were screened using an extensive test battery of cognitive tests that required over 30 min to administer. Classification and Regression Trees (CART) was used to identify a subset of the battery that could be administered quickly and which maintained high levels of sensitivity and specificity for a diagnosis of dementia. The Short and Sweet Screening Instrument (SASSI) is a brief battery consisting of three standard cognitive tests that can be administered in approximately 10 min. Compared to the full battery, it was more sensitive (94% vs. 90%) and had comparable specificity (91% vs. 92%) for dementia in this sample.
IL-1-Alpha and TNF-Alpha Differentially Regulate CD4 and Mac-1 Expression in Mouse Microglia
Authors: Yu Naichen , Zhang Xiaohong , Magistretti Pierre J. , Bloom Floyd E. 
Published: April 2003

The regulatory effects of the proinflammatory cytokines, interleukin-1α (IL-1α) and tumor necrosis factor-α (TNF-α) were investigated on CD4 and Mac-1 expression in mouse microglial cultures. The identity of the microglia in cultures was confirmed by multiple indices including morphology, uptake of acetylated low-density lipoprotein and lectin RCA 120 staining. Microglia growing on a monolayer of astrocytes (astrocyte-supported microglia) were both CD4- and Mac-1 positive (out of 94.5% Mac-1-positive cells, 85.3% were also CD4 positive). When astrocyte-supported microglia were replated directly onto culture dishes (plate-supported microglia), the percentage of CD4- and Mac-1-positive cells decreased to 12–29 and 20–25% resepctively. The addition of IL-1α or TNF-α to plate-supported microglia led to an upregulation of Mac-1 expression in a time- and dose-dependent manner with different EC50s (0.5 ng/ml for IL-1α and 2 ng/ml for TNF-α) but exhibited similar time-to-peak responses (over 12 h). The addition of IL-1α, but not TNF-α, also led to an increase in CD4 expression on plate-supported microglia with a similar dose response and time course. IL-1α treatment gave rise to an increase in the level of CD4 mRNA as assessed by RT-PCR. The possibility that cell proliferation was responsible for the observed effects on microglia was excluded by an analysis of <sup>3</sup>H-thymidine incorporation. Our results suggest that cultured mouse microglia express CD4 molecules which can be upregulated by IL-1α while Mac-1 can be upregulated by both IL-1α and TNF-α.