bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physiological and pathological angiogenesis in the endocrine system
Authors: Góth Miklós I. , Hubina Erika , Raptis Stefanos , Nagy György M. , Tóth Béla E. 
Published: December 2002

AbstractFormation of new blood vessels occurs in many physiological states (during development of the embryo, cycling changes of the female reproductive tract), as well as in pathological processes (such as diabetic retinopathy and wound healing). Angiogenesis has been shown to be related to tumor formation, prognosis, and response to treatment in many tumor types. Intratumoral microvessels can be related to tumor behavior or hormone secretion in different endocrine tumors. For example, invasive prolactinomas are more vascular than noninvasive adenomas; a surgical approach is more successful in macroprolactinomas with lower microvessel density. A higher number of microvessels have been found in papillary thyroid carcinomas during recurrences. A correlation between microvessel count and prognosis in papillary and medullary thyroid carcinomas has been suggested. Several stimulating and inhibiting factors involved in the regulation of angiogenesis have been identified. Among them, vascular endothelial growth factor (VEGF) has been shown to be critically involved in angiogenesis and also in the neovascularization of solid tumors. Dopamine agonists (already in clinical use for prolactinomas) have potent inhibitory actions on VEGF signaling, and thus may be a new tool in antiangiogenic therapy. Secretion of VEGF in the great majority of human pituitary adenomas is inhibited by dexamethasone. This suggests that glucocorticoids can be considered in the treatment of certain pituitary tumors. The cyclic nature of angiogenesis in the female reproductive tract indicates that stimulation or inhibition of paracrine angiogenic factors may lead to new approaches for being able to influence reproductive endocrine disorders. Experimental and clinical aspects of interactions between angiogenic factors and tumor growth of the endocrine system are also discussed. Microsc. Res. Tech. 60:98–106, 2003. © 2002 Wiley‐Liss, Inc.
Angiogenesis in wound repair: Angiogenic growth factors and the extracellular matrix
Authors: Li Jie , Zhang Yan‐Ping , Kirsner Robert S. 
Published: December 2002

AbstractAngiogenesis is critical to wound repair. Newly formed blood vessels participate in provisional granulation tissue formation and provide nutrition and oxygen to growing tissues. In addition, inflammatory cells require the interaction with and transmigration through the endothelial basement membrane to enter the site of injury. Angiogenesis, in response to tissue injury, is a dynamic process that is highly regulated by signals from both serum and the surrounding extracellular matrix (ECM) environment. Vascular endothelial growth factor, angiopoietin, fibroblast growth factor, and transforming growth factor beta are among those most potent angiogenic cytokines in wound angiogenesis. The cooperative regulation of them is essential for wound repair. Migration of endothelial cells and development of new capillary vessels during wound repair is dependent on not only the cells and cytokines present but also the production and organization of ECM components both in granulation tissue and in endothelial basement membrane. The ECM regulates angiogenesis by providing scaffold support and signaling roles. They also serve as a reservoir and modulator for growth factors. Laminins are the major noncollagenous ECM of endothelial basement membrane. Two newly recognized laminins, 8 and 10, are the major laminins produced by human dermal microvascular endothelial cells. Laminin 10 is highly expressed in blood vessels around skin wounds. Laminin 8 promotes dermal endothelial cell attachment, migration, and tubule formation. Integrins with either beta 1 or alpha v subunits are the major cellular surface receptors for ECM molecules and mediate the interactions between cells and ECM during wound angiogenesis. Microsc. Res. Tech. 60:107–114, 2003. © 2002 Wiley‐Liss, Inc.
Microfilaments and microtubules maintain endothelial integrity
Authors: Lee Tsu‐Yee Joseph , Gotlieb Avrum I. 
Published: December 2002

AbstractThe endothelium is a highly metabolic monolayer of cells regulating numerous physiological and pathological functions that maintain the permeability and thromboresistant functions of the endothelium. The structure and function of the endothelial cytoskeleton prevents vascular disease by regulating the structure of the endothelium to act as a resting molecular barrier to atherogenic proteins and by becoming an activated layer of migrating cells to repair denuding injuries. The purpose of this review is to examine the structure of the endothelial cytoskeleton and its roles in cell–cell and cell–substratum adhesion, cell signaling, and regulation of wound repair. Studies focused on the cellular and molecular biology of the structure and function of the endothelial cytoskeleton and in wound repair are reviewed. The cytoskeleton is a key regulator in maintaining endothelial integrity and in restoring integrity following injurious denudation, such as those that occur in the pathogenesis of atherosclerosis. Actin microfilaments and their associated adherens junctions and focal adhesions are important regulators of cell signaling, cell locomotion, cell adhesion, and wound repair mechanisms. Various proteins have been implicated in controlling cytoskeletal‐based endothelial function and repair such as tyrosine kinases/phosphatases and the Rho family of proteins. The normal function of the endothelium is highly dependent on the endothelial cytoskeleton. Disruption and dysfunction of the cytoskeleton may result in impairment of endothelial function, subsequently tipping the balance towards vascular disease. Thus, an understanding of the cellular and molecular biology of the endothelial cytoskeleton is essential in our understanding of the pathogenesis of vascular disease, especially atherosclerosis. Microsc. Res. Tech. 60:115–127, 2003. © 2002 Wiley‐Liss, Inc.
Suspected early or mild chronic pancreatitis: Enhancement patterns on gadolinium chelate dynamic MRI
Authors: Zhang Xiao‐Ming , Shi Hongyu , Parker Laurence , Dohke Masako , Holland George A. , Mitchell Donald G. 
Published: December 2002

AbstractPurposeTo assess whether measuring the pattern of pancreatic enhancement on gadolinium chelate dynamic magnetic resonance imaging (MRI) is helpful for diagnosis of suspected early or mild chronic pancreatitis.Materials and MethodsIn this retrospective study, 24 patients with suspected early or mild chronic pancreatitis, classified by imaging criteria of equivocal chronic pancreatitis (ultrasound, computed tomography [CT] or ERCP) grading, had dynamic MRI that included unenhanced, arterial dominant, early venous, and late venous phases of contrast enhancement. Twenty patients without pancreatic diseases also had the dynamic sequence as a control group. The signal intensity was measured at the pancreatic head, body, and tail on all phases, and for each, the signal intensity ratio (SIR, the signal intensity in postcontrast divided by that in precontrast) was calculated. Two radiologists independently reviewed the images of the patients with suspected early or mild chronic pancreatitis for pancreatic morphologic abnormalities without knowing the results of signal intensity measurements.ResultsOn unenhanced images, there was no significant difference of signal intensity between control and pancreatitis groups (P < 0.05). In the pancreatitis group, but not in the control group, the unenhanced signal intensity of the pancreatic head and body were significantly higher than that of the tail (P < 0.05). In the control group, the greatest enhancement (highest SIR) after injection was in the arterial phase (1.89 ± 0.31), significantly higher than that in the early venous phase (1.68 ± 0.17, P < 0.01) and in the late venous phase (1.61 ± 0.15, P < 0.001). The pancreatitis group, however, had an arterial phase SIR (1.65 ± 0.23) that was significantly lower than its early venous phase SIR (1.75 ± 0.22, P < 0.05) and lower than the arterial phase SIR of the control group (P < 0.01). The presence of an SIR less than 1.73 in the arterial phase and/or a delayed peak enhancement after contrast agent administration had a sensitivity and specificity of diagnosing early or mild chronic pancreatitis of 92% and 75%, respectively. This sensitivity was significantly higher than the sensitivity of 50% for diagnosis based on morphologic abnormalities (P < 0.05).ConclusionMeasuring pancreatic signal intensity on gadolinium chelate dynamic MRI is helpful for diagnosing early or mild chronic pancreatitis, especially before apparent pancreatic morphologic or signal intensity changes are present. J. Magn. Reson. Imaging 2003;17:86–94. © 2002 Wiley‐Liss, Inc.
Renal diffusion and BOLD MRI in experimental diabetic nephropathy
Authors: Ries Mario , Basseau Fabrice , Tyndal Benoît , Jones Richard , Deminière Colette , Catargi Bogdan , Combe Christian , Moonen Chrit W.T. , Grenier Nicolas 
Published: December 2002

AbstractPurposeTo investigate the possibility of using combined blood oxygen level‐dependent (BOLD) imaging and diffusion‐weighted imaging (DWI) to detect pathological and physiological changes in renal tissue damage of the kidney induced by chronic renal hyperfiltration.Materials and MethodsThe apparent diffusion coefficient (ADC) and the T2* value within the inner compartments of the kidneys of 17 rats with diabetes mellitus were compared with the results obtained from a control group (N = 16). The influence of dynamic changes of the renal function on the blood‐oxygen saturation was evaluated by comparing the T2* values before and after the active reduction of tubular transport by furosemide injection.ResultsAll compartments of the diabetic kidney showed significantly (P < 0.05) lower T2*‐values compared to the control group. In particular, the very low values in the outer stripe (OS) of the outer medulla (OM) (T2*‐normal: 69.4 ± 10.9 msec; T2*‐diabetic: 51.4 ± 13.9 msec) indicated either hypoxia due to hyperfiltration, or renal blood volume changes. Diffusion imaging of the same area showed significantly lower ADC values (ADC‐normal: 1.45 ± 0.26; ADC‐edema: 1.19 ± 0.25 [10–9m2/s]) that correlated with pathological findings on histopathology. The injection of furosemide significantly (P < 0.05) increased T2* in all compartments of both populations while the ADC remained unchanged.ConclusionBOLD‐contrast imaging appears to be able to depict tissue at risk from ischemia by revealing information about the balance between tubular workload and delivery of oxygen, and thus may reflect a measure of the reserve capacity. The diffusion measurements apparently reveal J. Magn. Reson. Imaging 2003;17:104–113. © 2002 Wiley‐Liss, Inc.
Stenosis detection in forearm hemodialysis arteriovenous fistulae by multiphase contrast‐enhanced magnetic resonance angiography: Preliminary experience
Authors: Planken R. Nils , Tordoir Jan H.M. , Dammers Ruben , de Haan Michiel W. , Oei T. Khiam , van der Sande Freek M. , van Engelshoven Jos M.A. , Leiner Tim 
Published: December 2002

AbstractPurposeTo assess the feasibility and accuracy of multiphase contrast‐enhanced magnetic resonance angiography (CE‐MRA) in patients with dysfunctioning hemodialysis arteriovenous fistulae (AVF), using digital subtraction angiography (DSA) as the standard of reference.Materials and MethodsFifteen patients with dysfunctioning AVF (eight radiocephalic and seven graft AVF) underwent CE‐MRA. Dysfunction was defined as a flow decline of more than 25% in 1 month measured by dilutional flow measurements. CE‐MRA was performed during injection of 35 mL of gadolinium‐DTPA. The CE‐MRA sequence consisted of a time‐resolved series of 10 scans, each lasting approximately 10 seconds. The technical parameters were TR/TE/FA/voxel = 5.4/1.6/40/3.1 mm3, and a rectangular surface reception coil was used. All patients were scheduled to undergo DSA at which an intervention was carried out when a stenosis ≥50% was seen. Two observers, unaware of each other's findings and the findings at DSA, quantified the number and degree of stenosis in the failing AVF. Image quality for CE‐MRA and DSA was scored on a 3‐point scale. The diagnostic performance of CE‐MRA was analyzed with receiver‐operator characteristic (ROC) analysis.ResultsCE‐MRA and DSA examinations were performed without side effects in all 15 patients. Image quality was scored significantly better on CE‐MRA (observer 1: CE‐MRA, 2.0; DSA, 1.3; P =.001; observer 2: CE‐MRA, 2.0; DSA, 1.4; P =.002). Interobserver agreement for detection of ≥50% stenosis was 0.81 (95% confidence interval (CI) = 0.71–0.92) for CE‐MRA and 0.69 (95% CI = 0.55–0.84) for DSA. ROC analysis revealed a mean area under the curve of 0.78. On the patient level, at the ≥50% threshold, mean sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 100% (95% CI = 69%–100%), 10% (95% CI = 0%–78%), 70% (95% CI = 38%–92%), and 100% (95% CI = 50%–100%), respectively. At the ≥75% threshold, mean sensitivity, specificity, PPV, and NPV were 75% (95% CI = 20%–99%), 78% (95% CI = 39%–98%), 55% (95% CI = 12%–96%), and 89% (95% CI = 52%–100%), respectively.ConclusionCE‐MRA is a useful diagnostic tool for detecting stenoses in flow‐declined hemodialysis AVF prior to interventional DSA. J. Magn. Reson. Imaging 2003;17:54–64. © 2002 Wiley‐Liss, Inc.
In vivo assessment of absolute perfusion in the murine skeletal muscle with spin labeling MRI
Authors: Streif Jörg U.G. , Hiller Karl‐Heinz , Waller Christiane , Nahrendorf Matthias , Wiesmann Frank , Bauer Wolfgang R. , Rommel Eberhard , Haase Axel 
Published: December 2002

AbstractPurposeTo assess absolute perfusion in the skeletal muscle of mice in vivo with spin labeling magnetic resonance imaging (MRI) under normal and stress conditions.Materials and MethodsAbsolute perfusion in the skeletal muscle of 27 C57BL/6 mice was assessed in vivo non‐invasively by spin labeling MRI at 7.05 T. This technique was based on the acquisition of T1 maps with global and slice‐selective spin inversion in separate acquisitions. T1 mapping was performed by inversion recovery snapshot fast low angle shot imaging. To guarantee proper spin inversion within the whole mouse, a dedicated radiofrequency (RF) coil combination was constructed. A birdcage resonator was used for transmission, while detection of the MRI signal was achieved by a surface coil.ResultsBasal perfusion in the hindlimbs was determined to be 94 ± 10 mL (100 g · minute)–1 (mean ± standard error of the mean [SEM], N = 27). This value is in good agreement with perfusion values determined by invasive techniques such as microspheres. A subgroup of six animals received a constant dose of 4 mg (kg · minute)–1 of the vasodilator adenosine by an intraperitoneal catheter. In this case, perfusion was significantly increased to 179 ± 56 mL (100 g · minute)–1 (mean ± SEM, N = 6, P < 0.02). Mean basal perfusion in this subgroup was 96 ± 26 mL (100 g · minute)–1.ConclusionSpin labeling MRI is a well‐suited technique for the in vivo assessment of absolute perfusion in the murine skeletal muscle. J. Magn. Reson. Imaging 2003;17:147–152. © 2002 Wiley‐Liss, Inc.
Initial in vivo experience with steady‐state subzone‐based MR elastography of the human breast
Authors: Van Houten Elijah E.W. , Doyley Marvin M. , Kennedy Francis E. , Weaver John B. , Paulsen Keith D. 
Published: December 2002

AbstractPurposeTo describe initial in vivo experiences with a subzone‐based, steady‐state MR elastography (MRE) method. This sparse collection of in vivo results is intended to shed light on some of the strengths and weaknesses of existing clinical MRE approaches and to indicate important areas of future research.Materials and MethodsElastic property reconstruction results are compared with data compiled from the limited existing body of published studies in breast elasticity. Mechanical parameter distributions are also investigated in terms of their implications for the nature of biological soft tissue. Additionally, a derivation of the statistical variance of the elastic parameter reconstruction is given and the resulting confidence intervals (CIs) for different parameter solutions are examined.ResultsBy comparison with existing estimates of the elastic properties of breast tissue, the subzone‐based, steady‐state MRE method is seen to produce reasonable estimates for the mechanical properties of in vivo tissue.ConclusionMRE shows potential as an effective way to determine the elastic properties of breast tissue, and may be of significant clinical interest. J. Magn. Reson. Imaging 2003;17:72–85. © 2002 Wiley‐Liss, Inc.
Kinetics and mechanism of oxidation of antimony(III) by keggin‐type 12‐tungstocobaltate(III) in aqueous hydrochloric acid medium
Authors: Bhosale B. D. , Gokavi G. S. 
Published: December 2002

AbstractThe reaction between Sb(III) and [CoIIIW12O40]5− proceeds with two, one‐electron steps; formation of unstable Sb(IV) is the slow first step followed by its reaction with another oxidant in a fast step. The reaction rate is unaffected by the [H+] as there are no protonation equlibria involved with both the reactants, whereas the accelerating effect of chloride ion is due to the formation of an active chlorocomplex of the reductant, SbCl63−. Increase in the ionic strength and decrease in the relative permittivity of the medium increases the rate of the reaction, which is attributed to the formation of an outer‐sphere complex between the reactants. The activation parameters were also determined and these values support the proposed mechanism. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 35: 9–14, 2003
Kinetic evidence of a common mechanism in the oxidations of diethyl sulfide by dichromates and halochromates of heterocyclic bases
Authors: Karunakaran C. , Karuthapandian S. , Suresh S. 
Published: December 2002

AbstractThe oxidations of diethyl sulfide by potassium dichromate, pyridinium dichromate, quinolinium dichromate, imidazolium dichromate, nicotinium dichromate, isonicotinium dichromate, pyridinium fluorochromate, quinolinium fluorochromate, imidazolium fluorochromate, pyridinium chlorochromate, quinolinium chlorochromate, and pyridinium bromochromate follow identical kinetic orders—first‐order each with respect to the chromium(VI) reagents, sulfide and hydrogen ion, and moderately inhibited by manganese(II) ion. The energy of activation varies linearly with the logarithm of frequency factor and so does the enthalpy of activation with the entropy of activation. Also, the activation free energies do not differ significantly. The dichromates and halochromates of heterocyclic bases oxidize diethyl sulfide via a common mechanism. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 35: 1–8, 2003
Reaction of H + ketene to formyl methyl and acetyl radicals and reverse dissociations
Authors: Lee Jongwoo , Bozzelli Joseph W. 
Published: December 2002

AbstractThermochemical properties for reactants, intermediates, products, and transition states important in the ketene (CH2CO) + H reaction system and unimolecular reactions of the stabilized formyl methyl (C·H2CHO) and the acetyl radicals (CH3C·O) were analyzed with density functional and ab initio calculations. Enthalpies of formation (ΔHf°298) were determined using isodesmic reaction analysis at the CBS‐QCI/APNO and the CBSQ levels. Entropies (S°298) and heat capacities (Cp°(T)) were determined using geometric parameters and vibrational frequencies obtained at the HF/6‐311G(d,p) level of theory. Internal rotor contributions were included in the S and Cp(T) values. A hydrogen atom can add to the CH2‐group of the ketene to form the acetyl radical, CH3C·O (Ea = 2.49 in CBS‐QCI/APNO, units: kcal/mol). The acetyl radical can undergo β‐scission back to reactants, CH2CO + H (Ea = 45.97), isomerize via hydrogen shift (Ea = 46.35) to form the slight higher energy, formyl methyl radical, C·H2CHO, or decompose to CH3 + CO (Ea = 17.33). The hydrogen atom also can add to the carbonyl group to form C·H2CHO (Ea = 6.72). This formyl methyl radical can undergo β scission back to reactants, CH2CO + H (Ea = 43.85), or isomerize via hydrogen shift (Ea = 40.00) to form the acetyl radical isomer, CH3C·O, which can decompose to CH3 + CO. Rate constants are estimated as function of pressure and temperature, using quantum Rice–Ramsperger–Kassel analysis for k(E) and the master equation for falloff. Important reaction products are CH3 + CO via decomposition at both high and low temperatures. A transition state for direct abstraction of hydrogen atom on CH2CO by H to form, ketenyl radical plus H2 is identified with a barrier of 12.27, at the CBS‐QCI/APNO level. ΔHf°298 values are estimated for the following compounds at the CBS‐QCI/APNO level: CH3C·O (−3.27), C·H2CHO (3.08), CH2CO (−11.89), HC·CO (41.98) (kcal/mol). © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 35: 20–44, 2003
Estimation of rate constants for hydrogen atom abstraction by OH radicals using the CH bond dissociation enthalpies: Haloalkanes and haloethers
Authors: Chandra Asit K. , Uchimaru Tadafumi , Urata Shingo , Sugie Masaaki , Sekiya Akira 
Published: December 2002

AbstractWe propose a semiempirical procedure for the estimation of the rate constants for hydrogen atom abstraction reactions of OH radicals with haloalkanes and haloethers. Our procedure is derived from the collision theory based kinetic equation, which was originally proposed by Heicklen (Int. J. Chem. Kinet. 1981, 13, 651). This equation provides the estimates for the rate constants of hydrogen abstraction from the CH bond dissociation enthalpy for each potential hydrogen atom abstraction site. We reparameterized the equation and then applied this procedure to a series of haloalkane and haloether molecules. The results obtained from the new equations are found to be quite satisfactory. In addition, we also report highly reliable calculated values of the CH bond dissociation enthalpies for six environmentally important haloether molecules (CH2FOCH2F, CHF2CF2OCH2CF3, CF3CH2OCH2CF3, CF3CF2CH2OCHF2, CHF2OCF2CHFCl, and CHF2OCHClCF3). © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 35: 130–138, 2003
Kinetics of the gas‐phase reaction of n‐C6–C10 aldehydes with the nitrate radical
Authors: Noda Jun , Holm Camilla , Nyman Gunnar , Langer Sarka , Ljungström Evert 
Published: December 2002

AbstractRate coefficients for gas‐phase reaction between nitrate radicals and the n‐C6–C10 aldehydes have been determined by a relative rate technique. All experiments were carried out at 297 ± 2 K, 1020 ± 10 mbar and using synthetic air or nitrogen as the bath gas. The experiments were made with a collapsible sampling bag as reaction chamber, employing solid‐phase micro extraction for sampling and gas chromatography/flame ionization detection for analysis of the reaction mixtures. One limited set of experiments was carried out using a glass reactor and long‐path FTIR spectroscopy. The results show good agreement between the different techniques and conditions employed as well as with previous studies (where available). With butanal as reference compound, the determined values (in units of 10−14 cm3 molecule−1 s−1) for each of the aldehydes were as follows: hexanal, 1.7 ± 0.1; heptanal, 2.1 ± 0.3; octanal, 1.5 ± 0.2; nonanal, 1.8 ± 0.2; and decanal, 2.2 ± 0.4. With propene as reference compound, the determined rate coefficients were as follows: heptanal, 1.9 ± 0.2; octanal, 2.0 ± 0.3; and nonanal, 2.2 ± 0.3. With 1‐butene as reference compound, the rate coefficients for hexanal and heptanal were 1.6 ± 0.2 and 1.8 ± 0.1, respectively. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 35: 120–129, 2003