bluuebunny/crossref_metadata_2025 huggingface dataset:
Multicenter clinical experience with flow cytometric method for fetomaternal hemorrhage detection
Authors: Chen Jenn C. , Davis Bruce H. , Wood Brent , Warzynski Michael J.
Published: December 2002

BACKGROUND

Enumeration of fetal red blood cells (RBCs) is important in the management of fetomaternal hemorrhage (FMH), particularly in situations of Rh incompatibility.

METHODS

We evaluated results from three institutions using the flow cytometric method (FCM) to detect fetal RBCs based on the anti‐hemoglobin F (HbF) monoclonal antibody method.

RESULTS

During 1997–2001, 69 of 1,248 patients (5.5%) had measurable fetal erythrocytes (RBCs) in maternal blood. Only 21 patients (1.7%) had more than 30 mL of fetal blood detected in maternal blood. Of the 11 patients with large FMH and clinical follow‐up, 7 had fetal demise (64%). In positive samples, significant differences were found in the fluorescence intensity (FI) of anti‐HbF antibody staining between HbF‐negative erythrocytes (HbF‐) and adult HbF containing erythrocytes (F cells; 4 ± 0 versus 57 ± 9 linear mean channels [LMC]; P < 0.001) and between HbF‐cells and fetal RBCs (4 ± 0 versus 433 ± 136 LMC; P < 0.001). In addition, significant differences were observed in forward light scatter intensity between HbF‐cells and fetal RBCs (298 ± 15 versus 355 ± 68 LMC, P = 0.03). The transportability of the test is also addressed by comparing results from two other laboratories. The experience of our three laboratories, as well as the results from the recently reinitiated College of American Pathologists survey, which compares FCM and manual methods, clearly documents the superiority of the FCM test over the manual Kleihauer‐Betke (KB) test.

CONCLUSIONS

The FCM is a simpler, more objective, and more precise alternative to the KB method in clinical testing. The high mortality rate associated with large FMH and therapeutic implications of these results should give laboratories motivation to abandon the KB method with more robust FCM to detect FMH. Cytometry (Clin. Cytometry) 50:285–290, 2002. © 2002 Wiley‐Liss, Inc.
Flow cytometric immunophenotyping test for staging/monitoring neuroblastoma patients
Authors: Warzynski Michael J. , Graham David M. , Axtell Richard A. , Higgins James V. , Hammers Yuki A.
Published: December 2002

Ten years ago, we made an incidental flow cytometric observation while immunophenotyping biopsy and marrow samples from children suspected to have leukemia/non‐Hodgkin's lymphoma, but were subsequently diagnosed with neuroblastoma. The samples contained neoplastic CD45− cells that had an extremely bright CD56+ (beyond the fourth decade on a four‐decade scale) population distinguishable from CD45+CD56usual density+ natural killer lymphocytes as well as other CD45−CD56usual density+ nonhematopoietic tumors such as small cell carcinoma or melanoma. Following the “rare event” philosophy of selecting one negative and two positive antigens, we initially tried a “cocktail” of CD45−CD56very bright+ neuron‐specific enolase (NSE)cytoplasmic+. We later modified the procedure to a more clinically applicable “lysed whole blood” CD45−CD56very bright+ ganglioside GD2+ cocktail to improve turnaround time (eliminating the cell permeabilization step for cytoplasmic NSE analysis), specificity, and sensitivity of the assay. A total of 123 marrow/tissue/fluid samples were analyzed by the various forms of the assay. Clearly interpretable samples had an 83% specificity and a 100% sensitivity. The three‐color GD2 assay has successfully detected cells in marrow samples to a level of 0.002% (1 per 105 cells) using patient samples (not artificially “spiked” material). We added CD81 expression of the neuroblastoma cells as a fourth color and now use this rare event clinical test to help stage and monitor all patients with neuroblastoma. Cytometry (Clin. Cytometry) 50:298–304, 2002. © 2002 Wiley‐Liss, Inc.
A new method for improving metaphase chromosome spreading
Authors: Deng Wen , Tsao Sai Wah , Lucas Joe N. , Leung C. S. , Cheung Annie L. M.
Published: December 2002

Background

The success of complex molecular cytogenetic studies depends on having properly spread chromosomes. However, inconsistency of optimum chromosome spreading remains a major problem in cytogenetic studies.

Methods

The metaphase spreading process was carefully timed to identify the most critical phase of chromosome spreading. The effects of dropping height of cell suspension, slide condition, drying time, fixative ratio, and relative humidity on the quality of metaphase spreads were studied by quantitative examination of metaphase chromosome spreads. Normal and immortalized human epithelial ovarian cells, neuroblastoma cells, and normal lymphocytes were tested.

Results

Humidity over the slide was the most important variable affecting the quality of chromosome spreads. Consistent improvement in chromosome spreading (larger metaphase area, less chromosome overlaps, or lower frequencies of broken metaphases) was obtained for all cell types if dynamic cell rehydration, occurring as fixative absorbs moisture from air, was made to coincide with the prompt fixation of spread chromosomes to the slide. This was achieved by dropping cells on dry glass slides placed in a shallow metal tray and then quickly lowering the tray into a covered 50°C water bath for slide drying.

Conclusions

A new and simple method for improving metaphase chromosome spreading was developed based on our study on the characteristics of chromosome spreading. Cytometry Part A 51A:46–51, 2003. © 2002 Wiley‐Liss, Inc.
Miniaturizing the comet assay with 3D vertical comets
Authors: Baert Philippe , Van Oostveldt Patrick
Published: December 2002

Background

The comet or single‐cell gel electrophoresis assay is a sensitive method for the detection of DNA damage. The main drawback of comet sampling is the low cell density necessary to prevent nucleus overlap after electrophoresis, which limits large‐scale high throughput screening. Another problem may be inconsistent comet focusing. We investigated whether an approach based on three‐dimensional (3D) confocal microscopy might be beneficial for these concerns.

Methods

A vertical comet assay enabling three‐dimensional confocal comet imaging of nuclei seeded at very high density was developed together with dedicated software algorithms to retrieve quantitative data at the single cell level.

Results

Three‐dimensional confocal comet imaging greatly relieved the user interactions of our nonautomated two‐dimensional comet sampling procedure. Batches of comets were blindly sampled, and confocal sectioning improved the clarity of the images and the accuracy of comet sampling. A 1‐Gy dose response was readily established. The sampling speed was competitive with that of commercial packages.

Conclusions

Vertical comet imaging is a new concept for fast and user‐friendly comet sampling that allows miniaturization of the assay. It may become an essential step toward high throughput screening and exploit the benefits of confocal imaging. Cytometry Part A 51A:26–34, 2003. © 2002 Wiley‐Liss, Inc.
Ethylenediaminetetraacetic acid plus citrate‐theophylline‐adenosine‐dipyridamole (EDTA‐CTAD): A novel anticoagulant for the flow cytometric assessment of platelet and neutrophil activation ex vivo in whole blood
Authors: Macey Marion , McCarthy Desmond , Azam Urooj , Milne Timothy , Golledge Peter , Newland Adrian
Published: December 2002

Ethylenediaminetetraacetic acid (EDTA) is the anticoagulant recommended for full blood counts, citrate is recommended for coagulation and platelet studies, and citrate‐theophylline‐adenosine‐dipyridamole (CTAD) inhibits platelet activation. Because the combination of EDTA and CTAD (E/C) is better than EDTA or CTAD alone for measuring platelet parameters on the ADVIA 120 Haematology System, we investigated whether it also offers advantages for the flow cytometric assessment of platelet and/or neutrophil activation and platelet–leucocyte aggregate formation ex vivo. Blood from healthy subjects was collected into E/C or citrate, kept at room temperature or at 4°C, and analysed 0 to 360 min later in the ADVIA 120 and by immunofluorescent flow cytometry. Platelet count, mean platelet volume, number of platelet clumps, mean platelet component, numbers of CD62P+ platelets and platelet–leucocyte aggregates, and expression of CD11b on neutrophils changed little over 360 min in blood with E/C kept at 4°C. In contrast, one or more parameter changed when blood was kept with E/C at ambient temperature or with citrate at either temperature. The use of E/C in in vitro and in vivo studies is illustrated. Platelet and neutrophil activation status ex vivo can be reliably assessed if blood is collected into E/C, held at 4°C, and analysed within 6 h. Cytometry Part B (Clin. Cytometry) 51B:30–40, 2003. © 2002 Wiley‐Liss, Inc.
Investigations of phagosomes, mitochondria, and acidic granules in human neutrophils using fluorescent probes
Authors: Bassøe Carl‐Fredrik , Li Nianyu , Ragheb Kathy , Lawler Gretchen , Sturgis Jennie , Robinson J. Paul
Published: December 2002

The oxidative burst is frequently evaluated by the conversion of dihydrorhodamine 123 (DHR) to rhodamine 123 (R123) and hydroethidium (HE) to ethidium with the use of flow cytometry (FCM). Added R123 accumulates in mitochondria, but during phagocytosis R123 originating from DHR has been observed in neutrophil granules. The present study was designed to identify the site of reactive oxygen species (ROS) formation and the intracellular traffic of R123 in neutrophils by using mitochondrial membrane potential probes and the lysosomotropic probe LysoTracker Red, which have not previously been applied to neutrophils. Quiescent and phagocytosing human peripheral blood neutrophils were incubated with DHR, HE, R123, MitoTracker Green (MTG), MitoTracker Red (CMX‐Ros), and LysoTracker Red alone and in all combinations of red and green probes, and studied by FCM and confocal laser scanning microscopy (CLSM). Phagosomes were filled with R123 originating from DHR. Phagocytosis also triggered the oxidative burst in oxidative response granules that differed from acidic granules. All the neutrophils stained with mitochondrial and lysosomotropic dyes. Added R123 and MTG selectively accumulated in mitochondria. Added R123, MTG, and DHR increased the fluorescence of CMX‐Ros and LysoTracker Red. This is the first FCM and CLSM demonstration of ROS formation in phagosomes. A distinct subpopulation of neutrophil granules, termed oxidative response granules, also was identified. Neutrophil mitochondrial membrane potential may be evaluated by incubating the cells with R123 and MTG, but results with CMX‐Ros should be interpreted with caution. HE and DHR seem to measure a common pathway in the oxidative burst. The simultaneous application of several probes for investigations of organelles carries the risk of probe interference. Cytometry Part B (Clin. Cytometry) 51B:21–29, 2003. © 2002 Wiley‐Liss, Inc.
CD87 as a marker for terminal granulocytic maturation: Assessment of its expression during granulopoiesis
Authors: Elghetany M. Tarek , Patel Jyoti , Martinez Joe , Schwab Hanna
Published: December 2002

Background

Understanding the normal surface maturation pattern of granulocytes is essential for the recognition of abnormal patterns, which in turn may be of diagnostic or pathogenetic significance in disorders such as myelodysplastic syndromes and inherited bone marrow failure disorders. CD87 plays a role in cellular interaction, cell migration, and inflammatory response. Surface expression of this antigen has not been adequately studied on bone marrow granulocytes, and the small number of previous studies has provided conflicting data.

Methods

Bone marrow aspirates from 11 control subjects were studied by flow cytometry and a lysed whole blood technique to compare surface expression of CD87 on marrow granulocytes with those of CD11b, CD16, CD35, and CD10, which are expressed at the myelocyte, metamyelocyte, band, and segmented stage of neutrophilic development, respectively. Four sorting experiments of CD87+ granulocytes were also performed.

Results

Our study showed no statistical difference between surface expression of CD35 and CD87 (P > 0.3), whereas significant differences existed between CD87 and the other antibodies (P < 0.004). Sorting experiments showed that more than 80% of CD87+ cells were bands and segmented neutrophils. Dual staining for CD87 and CD35 showed that most CD87+ granulocytes coexpress CD35.

Conclusions

CD87 is expressed on granulocytes at the band and segmented neutrophil stage of development and can be used to study normal and abnormal granulopoiesis. Cytometry Part B (Clin. Cytometry) 51B:9–13, 2003. © 2002 Wiley‐Liss, Inc.
Cloricromene conjugates with short‐chain alkylamino acids: synthesis and biological evaluation
Authors: Pignatello Rosario , Puleo Antonina , Giustolisi Simona , Cuzzocrea Salvatore , Dugo Laura , Caputi Achille P. , Puglisi Giovanni
Published: December 2002

Lipophilic amide conjugates of cloricromene (AD6) with alkylamino acids were designed in order to improve their central nervous system efficacy and to obtain more stable molecules in the bloodstream. In vivo effects on mean arterial blood pressure (MAP) and tumor necrosis factor (TNF)‐α plasma levels in Sprague‐Dawley rats subjected to endotoxic shock, induced by administration of Escherichia coli lipopolysaccharides (LPS) along with AD6 or its amide conjugates, were evaluated to assess whether the modification of the drug's carboxylic moiety through an amide bond would affect its pharmacological activity. LPS (4 mg kg−1 iv) elicited a time‐dependent decrease in MAP. Administration of AD6 conjugates 1 h prior to LPS delayed the development of late‐phase hypotension. LPS‐induced increases in TNF‐α plasma levels were also inhibited by the tested conjugates, with efficacies close to that of free AD6. In vitro stability studies of the conjugates indicated that they did not degrade rapidly into AD6 in the culture medium, suggesting that the observed effects can be ascribed to the conjugates themselves, and not to the cloricromene released after their hydrolytic degradation. Drug Dev. Res. 57:115–121, © 2002 Wiley‐Liss, Inc.
A brief questionnaire to assess readiness to change in adolescents with eating disorders: its applications to group therapy
Authors: Gusella Joanne , Butler Gordon , Nichols Laura , Bird Debbie
Published: December 2002

There has been little attention paid to the motivation of adolescents entering treatment for an eating disorder. The present study investigates a questionnaire designed to assess readiness to change based on Prochaska and DiClemente's model. The Motivational Stages of Change for Adolescents Recovering from an Eating Disorder (MSCARED) was examined with 34 adolescent girls attending one of six eating disorder treatment groups. The assessment prior to, and at the termination of the groups, included the MSCARED; Children's Depression Inventory (CDI); Perceived Body Image Scale (PBIS); Eating Disorders Inventory (EDI‐2—pre‐only); and, the Group Evaluation Form (post‐only). The MSCARED proved to be easy for youth to complete, reliable, and demonstrated concurrent and predictive validity. While the group was beneficial to girls at each stage of change, greater gains were reported by those who started at a more advanced stage. The clinical and research implications of measuring motivation to change are discussed. Copyright © 2002 John Wiley & Sons, Ltd and Eating Disorders Association.
Eating disorders in teenagers in east London: a survey
Authors: Bhugra Dinesh , Bhui Kamaldeep
Published: December 2002

Background:

Cultural factors have been shown to shape eating disorder symptoms. The origins of this cultural influence have rarely been investigated, although identity development is known to be important in the development of eating disorders. This study explores the prominence of bulimic symptoms and acculturation indices in order to further explain the association of the two. Quantitative and qualitative methods are used.

Method:

In a mixed sex school in East London all teenagers over the age of 13 years were given the BITE questionnaire and an acculturation schedule. A random sample of students proceeded to a second stage unstructured interview, during which a diagnosis on DSM‐III‐R criteria was established to make sense of the qualitative data.

Results:

A total of 266 subjects completed the questionnaire. A sample of 31 were interviewed for qualitative accounts of their eating pattern and their identity development. Asians were more likely to think about food, to fast and to indulge in compulsive eating. African–Caribbeans were more likely to eat ‘sensibly’ in front of others and make up in private. There were differences in acculturation items and bulimic symptoms among Asians appear to have more sociocentric origins.

Conclusions:

Cultural identity and acculturative processes influence the development of and form of bulimia. Copyright © 2002 John Wiley & Sons, Ltd and Eating Disorders Association.
Relationship of dissociative experiences to body shape concerns in eating disorders
Authors: Beato Luis , Rodríguez Cano Teresa , Belmonte Antonia
Published: December 2002

Objective:

To examine the relationship of dissociative experiences to body shape concerns in a Spanish sample of eating disorders as compared to a general population.

Method:

118 eating disordered outpatients and 64 controls completed the Body Shape Questionnaire (BSQ), the Rosenberg Self‐esteem Scale (RSE) and the Dissociative Experiences Scale (DES). Scores were compared within different diagnostic categories. Regression analysis was used to assess the predictive power of the DES and RSES for the BSQ.

Results:

36 (30.5 per cent) patients were found to be at high risk for dissociative disorders. In patients, DES together with RSES scores were predictors for BSQ.

Discussion:

These findings are consistent with the hypothesis that, in a subgroup of eating disorders, dissociation might be associated to the degree of dissatisfaction towards their own body and it might represent a way of coping with a negative self‐image. Copyright © 2003 John Wiley & Sons, Ltd and Eating Disorders Association.
Geoarchaeology of the Cooper site, northwest Oklahoma: Evidence for multiple Folsom bison kills
Authors: Carter Brian J. , Bement Leland C.
Published: December 2002

Stratified bison kills are rare in Paleoindian contexts on the North American Plains. The Cooper site is a Southern Plains example of an arroyo utilized on three separate occasions by Folsom hunters to trap and kill bison. Geoarchaeological investigations of the Cooper site, including reconstructing the site setting, analyses of the soils and sediments, and detailed stratigraphic descriptions, were employed to characterize the arroyo fill sequence. Three bone beds were found in stratified, sandy loam alluvium beneath eolian fine sandy loam within a paleoarroyo. A buried soil with Btk and Bk horizons formed in the alluvium above the bone beds. The bones are associated with Cg horizons; hence, the bison remains decomposed in anaerobic conditions. Alluvial deposits separating the three bone beds ranged in thickness from 1 to 30 cm and were thickest down the axis of the paleoarroyo. Additional information on the sequence of events was gleaned from the position of a painted bison skull and the condition of the bones. Combined, these lines of evidence point to three kill events and suggest that between one and ten years elapsed between the kills. © 2003 Wiley Periodicals, Inc.
Are M&A deal makers getting a wake‐up call?
Authors: Edwards James B.
Published: December 2002

It is obvious we are in a tough period for mergers and acquisitions (M&A). Today's
unforgiving economy leaves little margin for error. What are the implications for management and investors?
How should we change our strategies? How should we structure future deals? © 2003 Wiley
Periodicals, Inc.
Savvy exit strategies for mid‐sized companies
Authors: Kupferman Martin
Published: December 2002

Can you be as smart in exiting your business as you have been in building it? Many small or
mid‐sized business owners believe the future will take care of itself—if only they handle
day‐to‐day operations well. But that's overly optimistic, warns the author. Instead, he
explains savvy exit strategies that have worked for his clients. © 2003 Wiley Periodicals,
Inc.
Software systems: The missing element in M&A planning
Authors: Fitzgerald Mike
Published: December 2002

In the rush to complete a merger, the problem of merging two different IT systems often gets short shrift.
Applications software, operations, and methodologies are particularly important to consider. Merging two companies
will produce endless problems if their software isn't compatible. The author shows how to avoid that
nightmare. What factors should you consider? How can you steer clear of common mistakes?
© 2003 Wiley Periodicals, Inc.
Today's shaky M&A environment: How to avoid legal problems
Authors: Sherman Andrew J.
Published: December 2002

In today's uncertain M&A environment, it is more important than ever to avoid legal problems. The
author shows how to do it. © 2003 Wiley Periodicals, Inc.
How to implement change effectively
Authors: Suran Sandra
Published: December 2002

Mergers mean big change. But while you may have the vision of where you want to be, how do you get
there? And why is it so difficult to implement major change? © 2003 Wiley Periodicals,
Inc.
Sarbanes–Oxley Bill: New challenges for the financial professional
Authors: Weirich Thomas R. , Rouse Robert W.
Published: December 2002

The Sarbanes–Oxley Bill was Congress's response to the recent corporate scandals. What will it
change? And how will it affect you? © 2003 Wiley Periodicals, Inc.
The impact of goodwill on earnings
Authors: Cheng Kang
Published: December 2002

We can now evaluate what impact the recent goodwill rules have had on earnings. How should companies adjust
their business growth strategy to future years, in light of the recent rules? © 2003 Wiley
Periodicals, Inc.
What is the “true cost” of processing a freight bill?
Authors: Bass Howard K. , Garg Ashish , Iijima T.J.
Published: December 2002

In the current downturn, managers are searching for the so‐called “hidden fat” in their
departmental budgets. One area where focusing management attention could yield substantial value is the frequently
neglected accounts receivable (A/R) function. This article seeks to provide finance professionals
with rigorous estimates of A/R costs in the commercial freight industry. While pure processing costs are
significant, implicit financial costs such as receivable carrying costs can run up to three or four times higher
than processing costs. Web‐based payment solutions will continue to provide sterling opportunities to
improve relationships with trading partners, to save time, and to improve profit margins by cutting costs.
© 2003 Wiley Periodicals, Inc.
Who cooked the books?
Authors: Goldberg Stephen R. , Godwin Joseph H.
Published: December 2002

Mulford, Charles W., and Eugene Comiskey. 2002. The Financial Numbers Game; Detecting Creative
Accounting Practices (New York: John Wiley & Sons)

Albrecht, W. Steve. 2003. Fraud Examination (Mason, Ohio: South‐Western, a
division of Thomson Learning)
Pattern recognition and massively distributed computing
Authors: Davies E. Keith , Glick Meir , Harrison Karl N. , Richards W. Graham
Published: December 2002

A feature of Peter Kollman's research was his exploitation of the latest computational techniques to devise novel applications of the free energy perturbation method. He would certainly have seized upon the opportunities offered by massively distributed computing. Here we describe the use of over a million personal computers to perform virtual screening of 3.5 billion druglike molecules against protein targets by pharmacophore pattern matching, together with other applications of pattern recognition such as docking ligands without any a priori knowledge about the binding site location. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1544–1550, 2002
pKa, MM, and QM studies of mechanisms of β‐lactamases and penicillin‐binding proteins: Acylation step
Authors: Massova Irina , Kollman Peter A.
Published: December 2002

The acylation step of the catalytic mechanism of β‐lactamases and penicillin‐binding proteins (PBPs) has been studied with various approaches. The methods applied range from molecular dynamics (MD) simulations to multiple titration calculations using the Poisson–Boltzmann approach to quantum mechanical (QM) methods. The mechanism of class A β‐lactamases was investigated in the greatest detail. Most approaches support the critical role of Glu‐166 and hydrolytic water in the acylation step of the enzymatic catalysis in class A β‐lactamases. The details of the catalytic mechanism have been revealed by the QM approach, which clearly pointed out the critical role of Glu‐166 acting as a general base in the acylation step with preferred substrates. Lys‐73 shuffles a proton abstracted by Glu‐166 Oε to the β‐lactam nitrogen through Ser‐130 hydroxyl. This proton is transferred from Oγ of the catalytic Ser‐70 through the bridging hydrolytic water to Glu‐166 Oε. Then the hydrogen is simultaneously passed through SN2 inversion mechanism at Lys‐73 Nζ to Ser‐130 Oγ, which loses its proton to the β‐lactam nitrogen. The protonation of β‐lactam nitrogen proceeds with an immediate ring opening and collapse of the first tetrahedral species into an acyl‐enzyme intermediate. However, the studies that considered the effect of solvation lower the barrier for the pathway, which utilizes Lys‐73 as a general base, thus creating a possibility of multiple mechanisms for the acylation step in the class A β‐lactamases. These findings help explain the exceptional efficiency of these enzymes. They emphasize an important role of Glu‐166, Lys‐73, and Ser‐130 for enzymatic catalysis and shed light on details of the acylation step of class A β‐lactamase mechanism. The acylation step for class C β‐lactamases and six classes of PBPs were also considered with continuum solvent models and MD simulations. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1559–1576, 2002
Dynamic Charge Equilibration‐Morse stretch force field: Application to energetics of pure silica zeolites
Authors: Sefcik Jan , Demiralp Ersan , Cagin Tahir , Goddard William A.
Published: December 2002

We present the Dynamic Charge Equilibration (DQEq) method for a self‐consistent treatment of charge transfer in force field modeling, where atomic charges are designed to reproduce electrostatic potentials calculated quantum mechanically. Force fields coupled with DQEq allow charges to readjust as geometry changes in classical simulations, using appropriate algorithms for periodic boundary conditions. The full electrostatic energy functional is used to derive the corresponding forces and the second derivatives (hessian) for vibrational calculations. Using DQEq electrostatics, we develop a simple nonbond force field for simulation of silica molecular sieves, where nonelectrostatic interactions are described by two‐body Morse stretch terms. Energy minimization calculations with the new force field yield accurate unit cell geometries for siliceous zeolites. Relative enthalpies with respect to quartz and third‐law entropies calculated from harmonic vibrational analysis agree very well with available calorimetric data: calculated SiO2 enthalpies relative to α‐quartz are within 2 kJ/mol and entropies at 298 K are within 3 J/mol K of the respective experimental values. Contributions from the zero point energy and vibrational degrees of freedom were found to be only about 1 kJ/mol for the free energy of mutual transformations between microporous silica polymorphs. The approach presented here can be applied to interfaces and other oxides as well and it is suitable for development of force fields for accurate modeling of geometry and energetics of microporous and mesoporous materials, while providing a realistic description of electrostatic fields near surfaces and inside pores of adsorbents and catalysts. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1507–1514, 2002
Hybrid QM/MM molecular dynamics simulations for an ionic SN2 reaction in the supercritical water: OH− + CH3Cl → CH3OH + Cl−
Authors: Hori Takumi , Takahashi Hideaki , Nitta Tomoshige
Published: December 2002

A hybrid real space quantum mechanical/molecular mechanical (RS‐QM/MM) method has been applied to an ionic SN2 reaction (OH− + CH3Cl → CH3OH + Cl−) in water solution to investigate dynamic solvation effects of the supercritical water (SCW) on the reaction. It has been demonstrated that the approaching process of OH− to methyl group is prevented by water molecules in the ambient water (AW), while the reaction takes place easily in the gas phase. Almost the same solvation effect on the dynamics of OH− is observed in the SCW, though the bulk density of water is substantially reduced compared with that of the AW. It has been shown that the solvation of the SCW around the OH anion is locally identical to that of the AW due to the strong ion‐dipole interactions between OH− and water molecules. At the transition state, the QM/MM simulations have revealed that the excess electron is quite flexible, and the charge volume, as well as the fractional charges on atoms, vary seriously depending on the instantaneous solvent configurations. However, it has been found that the solvation energy in the SCW can be qualitatively related to the HOMO volume of the system by Born's equation. © 2002 Wiley Periodicals, Inc. J Comput Chem 24: 209–221, 2003
Inter‐ and intramolecular potential for the N‐formylglycinamide‐water system. A comparison between theoretical modeling and empirical force fields
Authors: Hermida‐Ramón Jose Manuel , Brdarski Steve , Karlström Gunnar , Berg Ulf
Published: December 2002

An intramolecular NEMO potential is presented for the N‐formylglycinamide molecule together with an intermolecular potential for the N‐formylglycinamide‐water system. The intramolecular N‐formylglycinamide potential can be used as a building block for the backbone of polypeptides and proteins. Two intramolecular minima have been obtained. One, denoted as C5, is stabilized by a hydrogen bonded five member ring, and the other, denoted as C7, corresponds to a seven membered ring. The interaction between one water molecule and the N‐formylglycinamide system is also studied and compared with Hartree‐Fock SCF calculations and with the results obtained for some of the more commonly used force fields. The agreement between the NEMO and SCF energies for the complexes is in general superior to that of the other force fields. In the C7 region the surfaces obtained from the intramolecular part of the commonly used force fields are too flat compared to the NEMO potential and the ab initio calculations. We further analyze the possibility of using a charge distribution obtained from one conformation to describe the charge distribution of other conformations. We have found that the use of polarizabilities and generic dipoles can model most of the changes in charge density due to the different geometry of the new conformations, but that one can expect additional errors in the interaction energies that are of the order of 1 kcal/mol. © 2002 Wiley Periodicals, Inc. J Comput Chem 24: 161–176, 2003
Enhanced docking with the mining minima optimizer: Acceleration and side‐chain flexibility
Authors: Kairys Visvaldas , Gilson Michael K.
Published: December 2002

The ligand–protein docking algorithm based on the Mining Minima method has been substantially enhanced. First, the basic algorithm is accelerated by: (1) adaptively determining the extent of each energy well to help avoid previously discovered energy minima; (2) biasing the search away from ligand positions at the surface of the receptor to prevent the ligand from staying at the surface when large sampling regions are used; (3) quickly testing multiple different ligand positions and orientations for each ligand conformation; and (4) tuning the source code to increase computational efficiency. These changes markedly shorten the time needed to discover an accurate result, especially when large sampling regions are used. The algorithm now also allows user‐selected receptor sidechains to be treated as mobile during the docking procedure. The energies associated with the mobile side chains are computed as if they belonged to the ligand, except that atoms at the boundary between side chains and the rigid backbone are treated specially. This new capability is tested for several well‐known ligand/protein systems, and preliminary application to an enzyme whose substrate is unknown—the recently solved hypothetical protein YecO (HI0319) from Haemophilus influenzae—indicates that side‐chains relaxations allow candidate substrates of various sizes to be accommodated. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1656–1670, 2002
Perturbations in paracrine control of the circulation: Role of the endothelial‐derived vasomediators, endothelin‐1 and nitric oxide
Authors: Mawji Imtiaz A. , Marsden Philip A.
Published: December 2002

Central to the control of vascular resistance in the systemic and pulmonary circulation and at the solid organ level is the function of the endothelial‐derived vasomediators, endothelin‐1 (ET‐1) and nitric oxide. Regulation of steady‐state levels of ET‐1 and endothelial nitric oxide synthase (eNOS) mRNAs represents an early and influential step in their biosynthesis and is highly responsive to exogenous stimuli. ET‐1 is expressed from a rapidly inducible promoter to generate a highly labile mRNA. Conversely, the eNOS promoter generates a constitutive level of a very stable mRNA and utilizes posttranscriptional mechanisms to modulate mRNA expression. The response of these genes in models of cellular activation commonly reflects a reciprocal pattern of regulation, namely, transcriptional induction of ET‐1 and destabilization of the eNOS mRNA. Elucidating the mechanisms influencing ET‐1 and eNOS mRNA is providing novel insight into endothelial gene regulation and providing opportunities for future therapeutic strategies. Microsc. Res. Tech. 60:46–58, 2003. © 2002 Wiley‐Liss, Inc.
Hormone regulation of endothelial apoptosis and proliferation in vessel regression and angiogenesis
Authors: Kontogeorgos George , Kontogeorgou Christina N.
Published: December 2002

Apoptosis and endothelial proliferation represent two adverse events which take place during vessel regression and angiogenesis, respectively. Apoptosis, an intrinsically activated programmed cell death, regulates cell elimination during vessel regression. In contrast, angiogenesis involves endothelial cell proliferation, migration, and vascular formation. Several molecules, including growth factors and cytokines, produced by endothelial cells and by other cells within the vicinity of the capillary network, regulate apoptosis and angiogenesis. Hormones and endocrine peptides acting via specific receptors located on the endothelial and perivascular stromal cells also have been found to be involved in the regulation of these two major antagonistic processes. The need for a better understanding of the mechanisms involved in hormone regulation of endothelial cell during apoptosis and angiogenesis is of great importance. The accumulating knowledge of hormone regulation may contribute to the introduction of new therapeutic strategies targeting the endothelial cells. Microsc. Res. Tech. 60:59–63, 2003. © 2002 Wiley‐Liss, Inc.
Inhibition of angiogenesis at endothelial cell level
Authors: Jekunen Antti , Kairemo Kalevi
Published: December 2002

Targeting of proliferating endothelial cells may allow a new therapeutic strategy against malignant tumors. Endothelial cells are easily accessible through the blood stream and genetically stable, reducing the possibility of acquiring drug resistance. There are numerous candidates for angiogenesis targets of drug development, e.g. a single endothelial cell has 2,000–20,000 different receptors on a cell membrane and inside a cell there are hundreds of second messengers. Inhibitors that are active at endothelial cells can be placed in three main groups inducing blockage of endothelial cell activator, direct inhibition of endothelial cells, inhibition of endothelial specific signaling. This review summarizes different approaches already in clinical trials. Specific effort is taken to give a view of and a new perspective over clinically relevant basic mechanisms, e.g. VEGF, ETS and radionanotargeting. It is clear that aggressive development work both at the preclinical and clinical levels is still needed; however, breakthroughs in applied therapies are expected at any time. Microsc. Res. Tech. 60:85–97, 2003. © 2002 Wiley‐Liss, Inc.
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

Formation 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

Angiogenesis 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

The 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

Purpose

To 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 Methods

In 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.

Results

On 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).

Conclusion

Measuring 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

Purpose

To 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 Methods

The 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.

Results

All 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.

Conclusion

BOLD‐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.