bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative PCR determination of human cytomegalovirus in blood cells
Authors: Satou J. , Funato T. , Satoh N. , Abe Y. , Ishii K.K. , Sasaki T. , Kaku M.
Published: August 2002

We evaluated a rapid and sensitive method to determine human cytomegalovirus (CMV) DNA levels in blood cells using a quantitative polymerase chain reaction (PCR) technique. This method is based on real‐time detection of PCR using a dual fluorescence‐labeled probe and a sequence detector. Ten copies of CMV DNA were detected, when 1 μg of DNA from blood samples was used with this method, and a good correlation was obtained between increased concentrations of copy numbers calculated and measured copy numbers of CMV DNA (r = 0.999). Forty normal subjects exhibited no copies of CMV DNA. On the other hand, a 6‐month‐old girl tested positive for increased levels 4 weeks after liver transplant. This method is simple, accurate, and sensitive for the quantitative detection of CMV DNA in vivo, indicating possible applications for the diagnosis and monitoring of CMV infection. J. Clin. Lab. Anal. 15:122–126, 2001. © 2001 Wiley‐Liss, Inc.
A cognitive perspective on resistance in psychotherapy
Authors: Newman Cory F.
Published: August 2002

The phenomena that comprise resistance in therapy are described and discussed from a cognitive viewpoint. The cases of Brian, Julie, and Victoria are reviewed to illustrate similar and contrasting manifestations of resistance, and suggestions for further individualized conceptualization and intervention are presented. Emphasis is placed on gaining an accurate, empathic understanding of the client's difficulties in changing. This is coupled with methods that allow the client some autonomy in charting the course of therapy, at the same time reinforcing the importance of the therapist's active involvement in educating and stimulating the client toward greater awareness and adaptability. In order to be maximally effective in encouraging such changes, therapists must be aware of their own tendencies to react adversely to client resistance. It is vital that therapists maintain their professionalism and confidence in persevering toward a better understanding of what will be helpful to their clients. © 2002 John Wiley & Sons, Inc. J Clin Psychol/In Session 58: 165–174, 2002.
Comparing adults in Los Angeles County who have and have not been homeless
Authors: Cousineau Michael R.
Published: August 2002

This study compares the formerly homeless with those who have not been homeless on several characteristics, based on a telephone survey of the general adulate population. The study was conducted in Los Angeles County. Researchers estimate how many and what percentage of adults (aged 18 or older) have been homeless in the past 5 years and the types of places people stayed while they were homeless. An estimated 370,000 adults have experienced homelessness within the past 5 years, 5.7% of the adult population (95% confidence interval [CI] 5.2–6.2). A third were literally homeless (in a shelter, street, or car). Just over half (56%) stayed with a friend or relative while homeless. Nine percent had a mixed experience. Compared to those who were not homeless, the formerly homeless are disproportionately poor, African American, not in the job market, on public assistance, and in poor health. There are few differences when comparing place of birth, citizenship status, or length of residence in Los Angeles County. Yet many homeless have been able to achieve some economic stability. Implications for the development of intervention and prevention programs are discussed. © 2001 John Wiley & Sons, Inc.
Transforming growth factor‐β isoforms differently stimulate proα2 (I) collagen gene expression during wound healing process in transgenic mice
Authors: Kinbara Takuro , Shirasaki Fumiaki , Kawara Shigeru , Inagaki Yutaka , de Crombrugghe Benoit , Takehara Kazuhiko
Published: August 2002

The role of many growth factors and cytokines in the process of wound healing has been intensively investigated in recent two decades. Among them, transforming growth factor‐βs (TGF‐βs) are well known to have a potent stimulatory effect on collagen synthesis as shown in various in vivo experimental systems. In the present study, we examined the effects of various growth factors on the promoter activity of the proα2 (I) collagen gene (COL1A2) during the wound healing process. For this purpose, we utilized transgenic mice harboring the −17 kb promoter sequence of the mouse COL1A2 linked to either a firefly luciferase or a bacterial β‐galactosidase gene. These mice exhibited normal phenotypic expression and the wound healing process was not impaired. Full thickness wounds were made by punch biopsy. We examined the effects of TGF‐β1, ‐β2, ‐β3, basic fibroblast growth factor, platelet‐derived growth factor, and connective tissue growth factor by applying them locally to the open wound every 2 days. Among the growth factors examined, all of the three isoforms of TGF‐β exhibited a more potent stimulatory effect on COL1A2 promoter activity than did other factors. In addition, while TGF‐β1 and ‐β2 significantly increased the number of fibroblasts which were positive for X‐Gal staining, TGF‐β3 treatment did not change the number of β‐galactosidase expressing cells. Accumulation of collagen fibers was observed to the same extent in the mice treated with TGF‐β1 and those with TGF‐β3. These findings suggest that TGF‐β1 and ‐β3 have similar but not identical regulatory mechanisms of COL1A2 expression, and that their pathophysiological roles in wound healing might be different from each other. J. Cell. Physiol. 190: 375–381, 2002. © 2002 Wiley‐Liss, Inc.
Profiling of retinoid mediated gene expression in synchronized human SCC cells using Atlas™ human cDNA expression arrays
Authors: Le Quan , Soprano Dianne Robert , Soprano Kenneth J.
Published: August 2002

While retinoids have been demonstrated to inhibit growth of many tumor cells, including SCC cells, the molecular mechanism by which retinoids suppress growth has not been elucidated. We previously found that the growth of SCC cells was significantly inhibited by all‐trans‐retinoic acid (all‐trans‐RA) treatment, and this inhibition was dependent on the binding and activation of RARs. These nuclear receptors bind retinoids and alter the rate of transcription of specific genes. To identify targets of the activated RARs which mediate growth inhibition, we growth arrested SCC‐25 cells in G‐0 and examined the effect of all‐trans‐RA on synchronized SCC‐25 cells. All‐trans‐RA inhibited G‐1 progression in quiescent SCC‐25 cells stimulated by FBS. More specifically, we found that the all‐trans‐RA execution point maps to mid/late G‐1, 6 to 10 h after stimulation. Using this synchronized cell system, we examined the expression of cell cycle regulatory genes in quiescent SCC‐25 cells stimulated with FBS and treated with all‐trans‐RA. We found few changes in expression of these genes which could account for all‐trans‐RA inhibition of SCC‐25 cell growth. In order to compare the patterns of expression of a wider selection of genes in all‐trans‐RA treated and non‐treated SCC‐25 cells, we have used expression array technology. We successfully performed expression profiling experiments on the Atlas™ Human cDNA arrays which contain 1176 human genes. We have identified several up‐regulated and several down‐regulated gene expression changes mediated by all‐trans‐RA treatment in synchronized SCC‐25 cells. This novel information will be useful in defining the mechanism by which retinoids suppress the growth of SCC cells. J. Cell. Physiol. 190: 345–355, 2002. © 2002 Wiley‐Liss, Inc.
Low oxygen tension stimulates collagen synthesis and COL1A1 transcription through the action of TGF‐β1
Authors: Falanga Vincent , Zhou Linda , Yufit Tatyana
Published: August 2002

Recent findings point to low oxygen tension (hypoxia) as an important mechanism for the expression of several eukaryotic genes. We have previously shown that hypoxia (2% O2), when compared to standard oxygen tension (20% O2), upregulates the mRNA levels of the human α1(I) (COL1A1) procollagen gene and transforming growth factor‐beta1 (TGF‐β1) in human dermal fibroblasts. In this report, we determined the effect of hypoxia on collagen synthesis and transcription. Exposure of human dermal fibroblasts to hypoxia for 24–72 h led to a threefold, dose‐dependent increase in collagenous protein (P < 0.0001; r = 0.9794) and to enhanced type I procollagen deposition, as shown by direct immunofluorescence. Transient transfections with a series of luciferase‐ and CAT‐promoter constructs of the human COL1A1 gene (spanning from − 2.5 kb to + 113 bp) showed that hypoxia increases the transcriptional activity of constructs having 5′ endpoints between − 804 bp and − 107 bp, with loss of stimulation at − 84 bp. Maximal increase in promoter activity in hypoxia was observed between − 190 and − 174 bp of the proximal promoter, once a cKrox repressor site (− 199 to − 224 bp) was deleted. Upregulation of COL1A1 mRNA levels in hypoxia was blocked by a TGF‐β1 anti‐sense oligonucleotide, and failed to occur in fibroblasts from TGF‐β1 knock‐out mice. Co‐transfection and overexpression with a Smad7 construct abrogated the increase in COL1A1 promoter activity observed in hypoxia. Upregulated transcriptional activity of the TGF‐β1 promoter in hypoxia was found to be maximal between − 453 and − 175 bp from the transcriptional start site. Since hypoxia is a critical feature of the early phases of wound repair, we conclude that it may act as a potent physiologic stimulus for collagen synthesis. TGF‐β1 appears to be a critical component of this response. J. Cell. Physiol. 191: 42–50, 2002. © 2002 Wiley‐Liss, Inc.
A comprehensive study of the loss of enzyme activity in a continuous membrane reactor – application to starch hydrolysis
Authors: Paolucci‐Jeanjean Delphine , Belleville Marie‐Pierre , Rios Gilbert M
Published: August 2002

Loss of enzyme activity is a problem associated with enzymatic reactions in continuous recycled membrane reactors (CRMR). It may result from catalyst leakage and also enzyme denaturation due to the effects of pH, temperature, shear effects or adsorption/deposit on membrane. In this study, the relative importance of these various factors has been assessed in order to reduce their adverse effects on starch hydrolysis in a CRMR. The effects of temperature and denaturation by adsorption/deposit on membrane were the most limiting phenomena. Reducing the temperature to overcome thermal denaturation was not a practical solution since this increases viscosity and thereby decreases permeate flux and reactor performance. Insofar that adsorption/deposit of enzymes on the membrane is directly linked to membrane fouling, back‐flushing or regularly purging retentate should reduce this phenomenon by lowering accumulation of high molecular weight products.

© 2001 Society of Chemical Industry
Inflamed urachal cyst containing calculi in an adult
Authors: Milotic Franko , Fuckar Zeljko , Gazdik Miljen , Cicvaric Tedi , Milotic Irena , Zauhar Gordana
Published: August 2002

The urachus is an embryonic structure that persists after birth in some individuals and can cause various problems. We report a case of an inflamed urachal cyst filled with a thick yellow fluid and several calculi in a woman with a 1‐month history of dysuria. Physical examination revealed a fist‐sized tumor located infraumbically in the midline. The patient's erythrocyte sedimentation rate was elevated; the results of all other routine laboratory studies were normal. Sonography showed a regularly shaped, ovoid, hypoechoic cystic area in the abdominal wall measuring 8 × 4 × 3 cm and containing several hyperechoic masses associated with acoustic shadowing. The wall of the cyst was inhomogeneous, and a thin hypoechoic linear tract linked the superior aspect of the mass to the umbilicus. The results of excretory urography, voiding cystography, and cystoscopy excluded an abnormality of the urinary system. A urachal cyst was diagnosed, and the mass was surgically removed. The surgical specimen was sent for histopathologic analysis, which confirmed the diagnosis. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:253–255, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.10056
Analysis of the three‐dimensional lymphatic architecture of the periodontal tissue using a new 3D reconstruction method
Authors: Fujimura Akira , Nozaka Yohichiro
Published: August 2002

Few studies of lymphatic vessels have been reported because diacrisis of this vascular system is rare. A complete examination of diacrisis of venula is not yet possible even using recent enzyme‐histochemical or immunohistochemical techniques. In this study, we examined a lymphatic vessel by serial sectioning from the afferent lymphatic of the lymph node to the periphery by three‐dimensional observation using a three‐dimensional reconstitution method. This method was conventional and accurate, and the time required for processing was markedly reduced by using a computer. Reconstitution of the vasculature became possible utilizing the entire section instead of a portion of a parenchymatous organ. We examined the lymphatic vessel architecture of various oral regions, including gingiva, tongue, and the floor of the mouth, using this method. In the future, using this method, we plan to investigate the alteration of lymphatic vessel architecture in a pathological region, and correlate these changes with the dynamics of lymphatic vessel absorption. Microsc. Res. Tech. 56:60–65, 2002. © 2002 Wiley‐Liss, Inc.
Adrenomedullin and proadrenomedullin N‐terminal 20 peptide in the normal prostate and in prostate carcinoma
Authors: Calvo Alfonso , Abasolo Ibane , Jiménez Nuria , Wang Zhou , Montuenga Luis
Published: August 2002

There is increasing evidence for the important role played by regulatory peptides in the physiology of the normal and neoplastic prostate. Adrenomedullin (AM) and pro‐adrenomedullin N‐terminal 20 peptide (PAMP) are recently discovered regulatory peptides widely expressed in the normal prostate and in prostate carcinoma. AM is produced in secretory, stroma, and endothelial cells and in neurons of the prostate ganglia. PAMP is only produced by neuroendocrine cells. The expression of AM mRNA is regulated by androgens in the rat prostate. The number of neuroendocrine cells expressing PAMP is increased in prostate carcinoma after androgen deprivation, which shows that this peptide could regulate androgen‐independent prostate tumor growth. However, the roles of AM and PAMP in the normal prostate and in prostate carcinoma are yet to be elucidated. Microsc. Res. Tech. 57:98–104, 2002. © 2002 Wiley‐Liss, Inc.
Organization and functional roles of the cytoskeleton in oligodendrocytes
Authors: Richter‐Landsberg Christiane
Published: August 2002

Mature oligodendrocytes are characterized by their numerous cytoplasmic extensions and flat membranous sheets. These sheets contain an extensive cytoskeletal network of microtubules (MTs) that maintain the cellular morphology, are specifically important for cellular sorting, and provide the rails for organelle trafficking. Mitochondria are localized in the primary and secondary processes and follow the tracks of the MTs in the cytoplasmic extensions. Oligodendrocytes express microtubule associated proteins (MAPs), specifically MAP2 and tau, which might be involved in the regulation and stabilization of the dynamic MT network in the myelin‐containing cellular processes. Tau and MAP2 heterogeneity increases during oligodendroglia maturation, and in mature oligodendrocytes tau mRNA with four MT binding domains are more prominent than in progenitor cells. Filamentous cell inclusions are a unifying mechanism underlying a variety of late‐onset neurodegenerative disorders and have mainly been viewed as neuron‐specific. Recent evidence indicated that glial changes occur in CNS degenerative diseases and seem to be a more common feature than previously thought. Glial fibrillary tangles (GFTs) in oligodendrocytes were observed in familial multiple system tauopathy, and glial cytoplasmic inclusions (GCIs) and oligodendroglia degeneration are the histological hallmark of multiple system atrophy (MSA). GCIs are associated with MTs and contain stress proteins and MAPs. Thus, neurons and glial cells share common cytoskeletal pathologies. During health and disease, MAPs might be important regulators of the structural stability and plasticity of the oligodendroglia cytoskeleton. Microsc. Res. Tech. 52:628–636, 2001. © 2001 Wiley‐Liss, Inc.
Sex‐linked genes are not silenced in fetal bovine testes expressing X‐inactive specific transcript (XIST)
Authors: Farazmand Ali , Koykul Weerapong , Peippo Jaana , Baguma‐Nibasheka Mark , King W. Allan , Basrur Parvathi K.
Published: August 2002

X‐inactive specific transcript (XIST), which is thought to be the central factor for the X‐inactivation process in female mammals, is known to be expressed in males during spermatogenesis. Our studies have shown that XIST is not only expressed in adult bovine testis but is also expressed in fetal, newborn, and prepubertal testes long before spermatogenesis is established. To determine whether the XIST expressed in fetal testes is involved in silencing the genes on the X chromosome, we investigated the status of X‐linked genes, including glucose‐6‐phosphate‐dehydrogenase (G6PD), hypoxanthine phosphoribosyl transferase (HPRT), and X‐linked zinc finger protein gene (ZFX), in fetal bovine gonads at the developmental stage, when meiosis is initiated in fetal ovaries in this species. Reverse transcription and a semiquantitative polymerase chain reaction based on the optical density of each gene‐specific band relative to that of the co‐amplified Quantum RNA 18S Internal Standard (Ambion, Austin, TX) showed that the XIST gene was expressed in the testes of approximately 90‐day‐old fetuses and was silent in all their nongonadal organs tested, although at a significantly lower level than that in fetal organs of female fetuses. Our observation that the expression of X‐linked genes in the fetal testis was comparable to that in male nongonadal organs, in which X inactivation does not occur, indicates that the low level of XIST, or XIST‐like RNA, expressed in the fetal bovine testis is not involved in silencing X‐linked genes. J. Exp. Zool. 290:327–340, 2001. © 2001 Wiley‐Liss, Inc.
Jet nebulization of PEI/DNA polyplexes: physical stability and in vitro gene delivery efficiency
Authors: Rudolph C. , Müller R. H. , Rosenecker J.
Published: August 2002

Background

Aerosol drug delivery currently represents the most acceptable and convenient delivery system for repeated drug application to the lungs. Although polyethyleneimine (PEI) has recently been demonstrated to mediate gene transfer successfully to mouse lungs via aerosol delivery, the effect of the jet nebulization process on the properties of PEI/DNA polyplexes has not yet been examined.

Methods

PEI/DNA polyplexes were generated in several commonly used solvents, such as distilled water, HEPES buffered saline (HBS), and 5% glucose. The complex parameters, such as particle size, zeta potential, DNA integrity, and transfection efficiency, were examined before and after jet nebulization.

Results

The complex parameters and the transfection efficiency were influenced by the solvent that was used for complex formulation and by the nebulization process itself. When polyplexes were formulated in HBS, the particle size, zeta potential, and DNA concentration were affected by the nebulization process and the transfection efficiency decreased dramatically. Polyplexes formulated in 5% glucose were less susceptible to the nebulization process, as indicated by only minor changes of the zeta potential and particle size when compared with HBS. The resulting transfecion efficiency was very low both before and after nebulization. Polyplexes formulated in distilled water had the most resistant behavior with the nebulization process. Zeta potential, particle size, and DNA integrity were influenced least of all by nebulization.

Conclusion

As a result, the transfection efficiency of PEI/DNA complexes remained constant throughout the nebulization process only when formulated in distilled water. These data suggest that distilled water represents the most appropriate solvent for polyplex formulation when delivered by jet nebulization. Copyright © 2001 John Wiley & Sons, Ltd.
Stars and triangles
Authors: Galvin Fred
Published: August 2002

A graph is Sm‐full if each vertex belongs to an induced star of order m. The stellarity of a vertex ν in a graph is the maximum size of an induced star centered at ν. Answering a question of Füredi, Mubayi, and West, we show that an Sm‐full finite graph is triangle‐free if the deletion of any edge produces a graph that is not Sm‐full. More generally, a finite graph is triangle‐free if the deletion of any edge lowers the stellarity of at least one of its endpoints. Neither of these results extends to infinite graphs; nevertheless, even an infinite Sm‐full graph has a triangle‐free Sm‐full spanning subgraph. © 2001 John Wiley & Sons, Inc. J Graph Theory 38: 170–176, 2001
Terms of trade shocks and the current account in a unified currency area
Authors: Sahely L. , Darius R. , Williams O.
Published: August 2002

The recent debate over the European Union's banana import regime that ensued following the World Trade Organization ruling that found it to be illegal, has implications for those developing countries that rely on preferential access to this market. This paper finds that for those territories of the Eastern Caribbean Central Bank monetary union, the terms of trade shocks are not very persistent and have a large temporary component. In addition, the terms of trade shocks had a small impact on the current account. These shocks however had a larger impact on the supply side suggesting price sensitivity of farmers. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of [phenyl‐2‐3H]‐travoprost: isopropyl ester prodrug of a selective prostaglandin FP receptor agonist
Authors: Selliah Robert , Dantanarayana Anura , Haggard Karen , Egan Judith , Do Ernest U. , May Jesse A.
Published: August 2002

A method for the preparation of tritium labeled travoprost, a new ocular hypotensive prostaglandin, is described. A highly selective catalytic deiodination has been identified which provides [phenyl‐2‐3H]‐travoprost in a single synthetic step from 2′‐iodo‐travoprost. Copyright © 2001 John Wiley & Sons, Ltd.
A novel and efficient asymmetric synthesis of carbon‐14 labeled (S,S)‐2,7‐di‐boc‐diamino[1,8‐14C2]suberic acid
Authors: Villani A. J. , Saunders D. , Shu A. Y. L. , Heys J. R.
Published: August 2002

Five hundred mCi of Potassium [14C]cyanide at a specific activity of 51 mCi/mmol was used to diastereoselectively introduce the carbon‐14 label into 1,6‐hexanedial via a thermodynamically controlled asymmetric Strecker reaction using (R)‐(‐)‐2‐phenylglycinol as the chiral auxiliary. The expected and predominant (R,S/S,R) diastereomer (2) was separated by preparative normal phase HPLC. The chiral auxiliary was removed by oxidation with lead tetraacetate and the resulting benzylimino nitrile exhaustively hydrolyzed in hydrochloric acid to give (S,S)‐2,7‐diamino[1,8‐14C2]suberic acid (6). Subsequent acylation with di‐tert‐butyldicarbonate gave the title compound (1) with a radiochemical purity of 95.5%, a specific activity of 113 mCi/mmol, and an enantiomeric purity of 95.5% e.e. To our knowledge this is the first report of the asymmetric Strecker methodology being applied to the synthesis of a carbon‐14 labeled amino acid. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis of 3H, 14C and 13C6 labelled Sch 58235
Authors: Hesk D. , Bignan G. , Lee J. , Yang J. , Voronin K. , Magatti C. , McNamara P. , Koharski D. , Hendershot S. , Saluja S. , Wang S.
Published: August 2002

3H‐Sch 58235 was prepared at a specific activity of 29.1 Ci/mmol by Ir(COD)(Cy3P)PyPF6 catalysed exchange with tritium gas. 14C‐Sch 58235 was prepared in three steps from p‐hydroxy[ring‐U‐14C]benzaldehyde with an overall radiochemical yield of 21%. 13C6‐Sch 58235 was similarly prepared in three steps from p‐hydroxy[ring‐U‐13C6]benzaldehyde in an overall yield of 41%. Copyright © 2002 John Wiley & Sons, Ltd.
Fine structural recognition specificities of IgE antibodies distinguishing amoxicilloyl and amoxicillanyl determinants in allergic subjects
Authors: Zhao Zhenjun , Baldo Brian A. , Baumgart Karl. W. , Mallon Dominic F. J.
Published: August 2002

IgE antibodies in the sera of subjects allergic to β‐lactam antibiotics detect a spectrum of specificities ranging from side‐chain groups to an entire penicillin or cephalosporin molecule. In addition to such structural heterogeneity of allergenic determinants, IgE antibodies in the sera of different allergic subjects show heterogeneous recognition responses. Detailed immunochemical studies were carried out on the sera of penicillin‐allergic subjects that showed selective and unexpected reactions with the frequently prescribed penicillin, amoxicillin. Antibodies from one subject reacted only with the amoxicilloyl determinant while IgE from another subject showed multiple reactivity with penicilloyl and penicillanyl determinants of different penicillins but not with the amoxicilloyl determinant. Quantitative hapten inhibition studies revealed that the combining sites of the former antibodies were complementary to amoxicillin in a form that permits binding to the hydroxyaminobenzyl side‐chain and the thiazolidine ring carboxyl. These conditions are satisfied with the drug in the ‘‐oyl’ but not in the ‘‐anyl’ form which involves linkage through the 2‐carboxyl of the thiazolidine ring. With the second serum, adsorption studies showed that the wide‐ranging reactivity of IgE was due to a single population of antibodies that detected a common specificity on the different penicillins. Combining site studies revealed clear recognition of the benzyl portion of the side‐chain of benzylpenicilloyl, benzylpenicillanyl, ampicilloyl, ampicillanyl and amoxicillanyl determinants when free antibody access to the side‐chain was possible but little or no recognition of the ring hydroxyl of amoxicillin. Such uninhibited access may not occur, however, when amoxicillin is conjugated in the ‘‐oyl’ form since opening the β‐lactam ring allows increased flexibility and rotation of the molecule and the possibility of close association of the hydroxyaminobenzyl side‐chain of amoxicillin with the linked peptide carrier. In such close steric association, H‐bonding involving the ring hydroxyl and amino acids of the carrier may prevent antibody access to the side‐chain region of the amoxicilloyl determinant. Copyright © 2001 John Wiley & Sons, Ltd.
Magnetic resonance imaging‐guided focused ultrasound thermal therapy in experimental animal models: Correlation of ablation volumes with pathology in rabbit muscle and VX2 tumors
Authors: Hazle John D. , Stafford R. Jason , Price Roger E.
Published: August 2002

Purpose

To further investigate the use of magnetic resonance‐guided focused ultrasound therapy (MRgFUS) as a noninvasive alternative to surgery in the local control of soft‐tissue tumors by ablating prescribed volumes of VX2 rabbit tumors and comparing with ablation of normal tissue volumes.

Materials and Methods

Small, ellipsoidal ablations at shallow depth were created using 5‐ to 15‐second sonication pulses at radio frequency (RF) powers of 50–125 W using a spherical, air‐backed transducer operating at 1.463 MHz under MR guidance in a 1.5‐T clinical scanner.

Results

Excellent correlation was observed between prescribed treatment volumes, MR thermal dosimetry, post‐treatment verification MRI, and histopathology. Multifocal ablations of VX2 tumors in rabbits at depths of up to 2.5 cm resulted in complete ablation of the prescribed treatment volume.

Conclusion

MRgFUS is an effective technique for treating tumors in vivo. Techniques developed for treatments in homogeneous tissue volumes are applicable in the more complicated tumor environment if MR temperature feedback is available to modify treatment delivery parameters. J. Magn. Reson. Imaging 2002;15:185–194. © 2002 Wiley‐Liss, Inc.
Evaluation of iron overload by single voxel MRS measurement of liver T2
Authors: Wang Zhiyue J. , Haselgrove John C. , Martin Marie B. , Hubbard Anne M. , Li Shuchun , Loomes Kathleen , Moore James R. , Zhao Huaqing , Cohen Alan R.
Published: August 2002

Purpose

To overcome the difficulty of poor signal‐to‐noise ratio of magnetic resonance imaging (MRI) in evaluating heavy iron overload by using a single voxel magnetic resonance spectroscopy (MRS) technique.

Materials and Methods

A single voxel STEAM pulse sequence with a minimum TE of 1.5 msec and a sampling volume of 36.6 cm3 was developed and applied to 1/T2 measurement of the liver in 14 patients with thalassemia whose liver iron concentration was determined through biopsy.

Results

The iron level ranged from 0.23 to 37.15 mg Fe/g dry tissue with a median value of 18.06. In all cases, strong MR signals were obtained. 1/T2 was strongly correlated with the liver iron concentration (r = 0.95, P < 0.00005).

Conclusion

The single voxel MRS measurement of T2 in liver iron overload overcomes the difficulty of lack of detectable signals in conventional MRI when the iron level is high. There is an excellent correlation between the iron level and 1/T2. J. Magn. Reson. Imaging 2002;15:395–400. © 2002 Wiley‐Liss, Inc.
Application of magnetization transfer at 3.0 T in three‐dimensional time‐of‐flight magnetic resonance angiography of the intracranial arteries
Authors: Thomas Steven D. , Al‐Kwifi Osama , Emery Derek J. , Wilman Alan H.
Published: August 2002

Purpose

To apply magnetization transfer (MT) at 3.0 T in three‐dimensional time‐of‐flight magnetic resonance angiography of the intracranial arteries.

Materials and Methods

This study was performed on phantoms and seven volunteers to determine the effects of MT at 3.0 T. By using a modulated MT approach and an altered phase encode order, the specific absorption rate (SAR) was kept below 3 W/kg over any 8‐second time period.

Results

For a 20‐degree flip angle and 36 msec repetition time, the background suppression at 3.0 T was improved with MT by 52 ± 5% for white matter and 40 ± 8% for grey matter, making the distal intracranial vasculature significantly more discernible.

Conclusions

MT at 3.0 T can significantly improve background suppression in 3D time‐of‐flight magnetic resonance angiography (MRA) of the intracranial arteries without exceeding SAR guidelines. J. Magn. Reson. Imaging 2002;15:479–483. © 2002 Wiley‐Liss, Inc.
Diffusion tensor imaging: Concepts and applications
Authors: Le Bihan Denis , Mangin Jean‐François , Poupon Cyril , Clark Chris A. , Pappata Sabina , Molko Nicolas , Chabriat Hughes
Published: August 2002

The success of diffusion magnetic resonance imaging (MRI) is deeply rooted in the powerful concept that during their random, diffusion‐driven displacements molecules probe tissue structure at a microscopic scale well beyond the usual image resolution. As diffusion is truly a three‐dimensional process, molecular mobility in tissues may be anisotropic, as in brain white matter. With diffusion tensor imaging (DTI), diffusion anisotropy effects can be fully extracted, characterized, and exploited, providing even more exquisite details on tissue microstructure. The most advanced application is certainly that of fiber tracking in the brain, which, in combination with functional MRI, might open a window on the important issue of connectivity. DTI has also been used to demonstrate subtle abnormalities in a variety of diseases (including stroke, multiple sclerosis, dyslexia, and schizophrenia) and is currently becoming part of many routine clinical protocols. The aim of this article is to review the concepts behind DTI and to present potential applications. J. Magn. Reson. Imaging 2001;13:534–546. © 2001 Wiley‐Liss, Inc.
Safety assessment of gadobenate dimeglumine (MultiHance®): Extended clinical experience from phase I studies to post‐marketing surveillance
Authors: Kirchin Miles A. , Pirovano Gianpaolo , Venetianer Carol , Spinazzi Alberto
Published: August 2002

Clinical trials completed by September 2000 on gadobenate dimeglumine (Gd‐BOPTA; MultiHance®) included 2540 adult and pediatric subjects that were administered this agent. For adult patient volunteers, the overall incidence of adverse events (AEs) was 19.8%, although marked study‐ and indication‐related differences were apparent. Events potentially related to Gd‐BOPTA administration were reported for 15.1% of adult patients. The vast majority of AEs were non‐serious, mild, transient, and self‐resolving. Headache, injection site reaction, nausea, taste perversion, and vasodilation were the most common AEs, reported with a frequency of between 1.0% and 2.6%. Serious AEs potentially related to Gd‐BOPTA were reported for five (0.2%) patients overall. Controlled studies revealed no differences between Gd‐BOPTA and other gadolinium chelates or placebo in the incidence and type of AEs. Similarly, no differences with respect to adult patients and/or comparator were noted in studies on pediatric subjects and subjects with renal or liver insufficiency. Post‐marketing surveillance of approximately 100000 doses revealed an overall AE incidence of < 0.03% with serious AEs reported for < 0.005% of patients. J. Magn. Reson. Imaging 2001;14:281–294. © 2001 Wiley‐Liss, Inc.
Anorectal melanomas do not harbour the kaposi sarcoma‐associated human herpesvirus type 8 DNA
Authors: Helmke Burkhard M. , Deichmann Martin , Otto Herwart F.
Published: August 2002

Anorectal melanomas are similar to cutaneous melanomas with regard to the mode of spread and to the immunophenotype. When compared with patients with cutaneous melanoma, those suffering from anorectal melanoma have a much worse outcome. The etiology of anorectal melanomas is as yet completely unknown. For anatomical reasons, ultra‐violet (UV‐B) radiation can not cause anorectal melanomas as in cutaneous tumours, that are associated with exposure of the skin to UV‐B radiation. As the cytokine interleukin‐6 (IL‐6) is known to stimulate melanoma tumour cell proliferation and a functional homologue of human IL‐6 has been identified recently in the HHV‐8 genome, this tumorigenic virus might be involved in the pathogenesis of anorectal melanomas. Twelve formalin fixed and paraffin embedded primary anorectal melanomas from seven female and five male patients with a mean age at diagnosis of 71 years (range 38–88 years) were investigated for the presence of HHV‐8 DNA. Using a specific and highly sensitive polymerase chain reaction protocol, this tumorigenic gamma‐herpesvirus was not detectable in any tumour. This data indicates that HHV‐8 is not involved in the development of anorectal melanomas. J. Med. Virol. 64:47–50, 2001. © 2001 Wiley‐Liss, Inc.
Molecular detection and sequencing of “Norwalk‐like viruses” in outbreaks and sporadic cases of gastroenteritis in Ireland
Authors: Foley Barbara , O'Mahony Jim , Hill Colin , Morgan John G.
Published: August 2002

Norwalk‐like viruses (NLVs) are now established as the most important causative agents of epidemic gastroenteritis worldwide. The overall objective of this study was to determine the molecular epidemiology of Irish NLV isolates for the first time by obtaining sequence data from specimens originating from outbreaks and sporadic cases of gastroenteritis. Eight samples from sporadic cases of gastroenteritis and nine isolates from separate NLV outbreaks were examined. Of the sporadic isolates, six were shown to be genogroup 2 (G2) by RT‐PCR, while two were G1. All of the outbreak isolates were G2. All isolates were partially sequenced within a highly conserved region of ORF1 (RNA‐dependent RNA polymerase gene). Sequence data were aligned and a dendogram was constructed. The results indicated that the majority of G2 isolates were seen to cluster with Bristol and Lordsdale virus, while the two G1 specimens were related most closely to Southampton virus. Further downstream sequence analysis of a number of the isolates confirmed this result. It is concluded that the majority of NLV isolates circulating in Ireland belong to the Bristol/Lordsdale clade. J. Med. Virol. 65:388–394, 2001. © 2001 Wiley‐Liss, Inc.
Suppressive effects of ansamycins on inducible nitric oxide synthase expression and the development of experimental autoimmune encephalomyelitis
Authors: Murphy Patricia , Sharp Anthony , Shin Joseph , Gavrilyuk Vitaliy , Dello Russo Cinzia , Weinberg Guy , Sharp Frank R. , Lu Aigang , Heneka Michael T. , Feinstein Douglas L.
Published: August 2002

The production of nitric oxide by the inflammatory isoform of nitric oxide synthase (NOS2) in brain glial cells is thought to contribute to the causes and development of neurological diseases and trauma. We previously demonstrated that activation of a heat shock response (HSR) by hyperthermia reduced NOS2 expression in vitro, and in vivo attenuated the clinical and histological symptoms of the demyelinating disease experimental autoimmune encephalomyelitis (EAE; Heneka et al. [2001] J. Neurochem. 77:568–579). Benzoquinoid ansamycins are fungal‐derived antibiotics with tyrosine kinase inhibitory properties, and which also induce a HSR by allowing activation of HS transcription factor HSF1. We now show that two members of this class of drugs (geldanamycin and 17‐allylamino‐17‐demethoxygeldanamycin) also induce a HSR in primary rat astrocytes and rat C6 glioma cells. Both drugs dose‐dependently reduced nitrite accumulation, NOS2 steady‐state mRNA levels, and the cytokine‐dependent activation of a rat 2.2‐kB NOS2 promoter construct stably expressed in C6 cells. These inhibitory effects were partially reversed by quercetin, a bioflavonoid which prevents HSF1 binding to DNA and thus attenuates the HSR. Ansamycins increased mRNA levels of the inhibitory IκBα protein, suggesting that inhibition of NFκB activation could contribute to their suppressive effects. Finally, in C57BL/6 mice actively immunized to develop EAE, a single injection of geldanamycin at 3 days after immunization reduced disease onset by over 50%. These results indicate that ansamycins can exert potent anti‐inflammatory effects on brain glial cells which may provide therapeutic benefit in neuroinflammatory diseases. © 2002 Wiley‐Liss, Inc.
Brain‐derived neurotrophic factor applied to the motor cortex promotes sprouting of corticospinal fibers but not regeneration into a peripheral nerve transplant
Authors: Hiebert G.W. , Khodarahmi K. , McGraw J. , Steeves J.D. , Tetzlaff W.
Published: August 2002

Previous experiments from our laboratory have shown that application of brain‐derived neurotrophic factor (BDNF) to the red nucleus or the motor cortex stimulates an increase in the expression of regeneration‐associated genes in rubrospinal and corticospinal neurons. Furthermore, we have previously shown that BDNF application stimulates regeneration of rubrospinal axons into a peripheral graft after a thoracic injury. The current study investigates whether application of BDNF to the motor cortex will facilitate regeneration of corticospinal neurons into a peripheral nerve graft placed into the thoracic spinal cord. In adult Sprague Dawley rats, the dorsal columns and the corticospinal tract between T9 and T10 were ablated by suction, and a 5‐mm‐long segment of predegenerated tibial nerve was autograft implanted into the lesion. With an osmotic pump, BDNF was infused directly into the parenchyma of the motor cortex for 14 days. Growth of the corticospinal tract into the nerve graft was then evaluated by transport of an anterograde tracer. Anterogradely labeled corticospinal fibers were not observed in the peripheral nerve graft in animals treated with saline or BDNF. Serotinergic and noradrenergic fibers, as well as peripheral sensory afferents, were observed to penetrate the graft, indicating the viability of the peripheral nerve graft as a permissive growth substrate for these specific fiber types. Although treatment of the corticospinal fibers with BDNF failed to produce regeneration into the graft, there was a distinct increase in the number of axonal sprouts rostral to the injury site. This indicates that treatment of corticospinal neurons with neurotrophins, e.g., BDNF, can be used to enhance sprouting of corticospinal axons within the spinal cord. Whether such sprouting leads to functional recovery after spinal cord injury is currently under investigation. © 2002 Wiley‐Liss, Inc.
Use of cDNA microarray in the search for molecular markers involved in the onset of Alzheimer's disease dementia
Authors: Pasinetti Giulio Maria
Published: August 2002

Alzheimer's disease (AD) is the most common form of dementia, affecting as many as 4 million older persons and results from abnormal changes in the brain that most likely begin long before cognitive impairment and other clinical symptoms become apparent. Thus, efforts aimed at identifying methods of early detection and diagnosis for improving AD care might be the most appropriate strategy to initiate promising new treatments and/or prevention. We used cDNA microarray technology to investigate the sequence of changes in gene expression in brain that may take place during the transition from normal cognitive functioning through the early stages of impairment to frank AD. We examined the expression of approximately 7,000 genes in the brains of cases at the early stage of AD dementia using reference sample cases characterized by normal cognitive status. Genes that are differentially regulated in early AD cases were identified and were categorized into gene clusters based on similarities in biological functions. This analysis revealed that selected biological processes, including protein and amino acid metabolism, cytoskeleton integrity, and fatty acid metabolism, are involved in early phases of AD dementia. Most notable is the observation that selected genes involved in neurotransmitter release are differentially regulated in the brains of cases at high risk for dimentia. This evidence supports the feasibility and usefulness of cDNA microarray techniques to study sequential changes of distinctive gene‐expression patterns in the brain as a function of the progression of AD dementia. The study suggests new means to dissect and classify stages of AD dementia, or neuropathology, at the molecular level. J. Neurosci. Res. 65:471–476, 2001. © 2001 Wiley‐Liss, Inc.
Altered gene expression in Schwann cells of connexin32 knockout animals
Authors: Nicholson Simone M. , Gomès Danielle , de Néchaud Béatrice , Bruzzone Roberto
Published: August 2002

The discovery that the dominant X‐linked form of Charcot‐Marie‐Tooth disease (CMTX), a genetic disease of the peripheral nervous system (PNS), is associated with mutations in connexin32 (Cx32) has brought attention to the importance of connexins in glial cell biology. To gain further insight into the consequences of Cx32 deficiency, we have undertaken a detailed characterization of the gene expression profile of Schwann cells isolated from the sciatic nerve of wild‐type and Cx32‐null mice. Schwann cells exhibit two distinct phenotypes, myelinating and nonmyelinating, which are defined by their different morphology with respect to axons and by their unique profile of gene expression. Our findings show that, regardless of the mouse genotype, cultured Schwann cells express similar levels of messages for a number of connexins and for genes characteristic of both the myelinating and the nonmyelinating phenotypes. Furthermore, we have identified Cx36, a member of the γ subclass of connexins, which are preferentially expressed in neuronal cells of mouse brain and retina, as an additional connexin present in Schwann cells. Mice lacking Cx32, however, exhibited a marked up‐regulation of glial fibrillary acidic protein (GFAP), a cytoskeletal protein usually synthesized only by nonmyelinating Schwann cells. This observation was extended to the PNS in vivo and did not reflect a general perturbation of the expression of other nonmyelinating Schwann cell genes. These findings demonstrate that the absence of Cx32 results in a distinct pattern of gene dysregulation in Schwann cells and that Schwann cell homeostasis is critically dependent on the correct expression of Cx32 and not just any connexin. Identifying the relationship between increased GFAP expression and the absence of Cx32 could lead to the definition of specific roles for Cx32 in the control of myelin homeostasis and in the development of CMTX. J. Neurosci. Res. 66:23–36, 2001. © 2001 Wiley‐Liss, Inc.
Estrogen stimulates brain‐derived neurotrophic factor expression in embryonic mouse midbrain neurons through a membrane‐mediated and calcium‐dependent mechanism
Authors: Ivanova Tatiana , Küppers Eva , Engele Jürgen , Beyer Cordian
Published: August 2002

We have provided evidence that 17β‐estradiol (E) synthesized in the midbrain promotes the differentiation of midbrain dopamine neurons through nonclassical steroid action. Because these developmental effects resemble those reported for brain‐derived neurotrophic factor (BDNF), we hypothesized that E influences dopaminergic cell differentiation through a BDNF‐dependent mechanism. Competitive RT‐PCR and ELISA techniques were employed to study first the developmental pattern of BDNF and trkB expression in the mouse midbrain. BDNF protein/mRNA levels peaked postnatally, whereas trkB did not fluctuate perinatally. To prove the hypothesis that E regulates BDNF expression in vivo, fetuses and newborns were treated with the aromatase antagonist CGS 16949A. CGS 16949A exposure reduced midbrain BDNF mRNA/protein levels. The coapplication of CGS 16949A and E abolished this effect. Midbrain cultures from mouse fetuses were used to investigate intracellular signaling mechanisms involved in transmitting E effects. Estrogen increased expression of BDNF but not of other neurotrophins. As concerns the related signaling mechanism, these effects were antagonized by interrupting intracellular Ca2+ signaling with BAPTA and thapsigargin but not by the estrogen receptor antagonist ICI 182,780. Insofar as E effects on BDNF mRNA expression were inhibited by cycloheximide, it appears likely that other, not yet characterized intermediate proteins take part in the estrogenic regulation of BDNF expression. We conclude that E exerts its stimulatory effect on the differentiation of dopaminergic neurons by coordinating BDNF expression. This particular E effect appears to be transmitted through Ca2+‐dependent signaling cascades upon activation of putative membrane estrogen receptors. J. Neurosci. Res. 66:221–230, 2001. © 2001 Wiley‐Liss, Inc.
Nongenomic mechanism mediates estradiol stimulation of axon growth in male rat hypothalamic neurons in vitro
Authors: Cambiasso M.J. , Carrer H.F.
Published: August 2002

The purpose of the present work was to investigate the participation of estradiol receptors (ER) in estrogen‐induced axon growth in vitro. Hypothalamic neurons from 16 day (E16) male rat fetuses were cultured with or without 17‐β‐estradiol at 1 × 10–7 M in basal medium or medium conditioned by astroglia derived from ventral mesencephalon (CM). After 48 hr in vitro, neurite outgrowth was quantified by morphometric analysis. An axogenic effect could be demonstrated for estradiol added to CM. With RT‐PCR, the mRNA transcript for ERα was found in the donor tissues as well as in the neuron cultures. In this model two specific nuclear ER blockers (tamoxifen and ICI 182,780) were ineffective in blocking the neuritogenic effect, and a membrane‐impermeable estrogen–albumin construct (E2‐BSA) was as effective as estradiol. These results indicate that the axogenic effect of estradiol at E16 is not exerted through the classical intracellular receptor signal transduction system and suggest the possibility of a membrane‐mediated mechanism. The data are discussed in light of our previous findings pointing to the interdependent activation of the estrogenic and the trophic factor signaling pathways that mediate stimulated axon growth. J. Neurosci. Res. 66:475–481, 2001. © 2001 Wiley‐Liss, Inc.