bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression and cellular localization of naturally occurring β estrogen receptors in uterine and mammary cell lines
Authors: Monje Paula , Boland Ricardo
Published: October 2002

The protein ER‐α has been exhaustively characterized in estrogen‐sensitive tissues and cell lines. However, little is known regarding the expression and cellular distribution of the newly identified ER‐β protein. We first quantified the specific estradiol binding site content in the estrogen‐responsive cell lines MCF‐7 (mammary) and SHM (myometrial). In the two cell types, these sites were associated to the expression of both ER‐α and ‐β isoforms. Native ER‐β was visualized to reside inside the nucleus by means of conventional indirect immunofluorescence. The cells expressed ER‐β as a tight ∼50 kDa triplet when resolved by sodium dodecyl sulfate–polyacrylamide gels (SDS–PAGE) and blotted using antibodies mapping different domains of the cloned ER‐β version. When the cells were subjected to homogenization and differential centrifugation, a substantial proportion of ER‐β immunolabeling was localized at membrane subfractions. ER‐β expression and partitioning was confirmed by Ligand blotting assays using estrogen derivatives coupled to different macromolecular tags. However, ER‐α was expressed as the major estrogen binding protein in both cell lines. Similar localization experiments were performed on HeLa cells (cervix). Though usually considered ER‐negative, this cell line displayed basal significant estrogen binding capacity and co‐expression of both ER isoforms. Taken as a whole, the results indicate that ER‐β could be expressed as functional estrogen binding proteins among a dominant population of ER‐α sites in the cell lines under study. J. Cell. Biochem. 86: 136–144, 2002. © 2002 Wiley‐Liss, Inc.
Effects of estrogen on collagen synthesis by cultured human osteoblasts depend on the rate of cellular differentiation
Authors: Ireland Deborah C. , Bord Sharyn , Beavan Siân R. , Compston Juliet E.
Published: October 2002

Estrogen is known to act on osteoblasts according to their stage of differentiation and estrogen receptor (ER) isoform expression. The aim of this study was to determine when type I collagen (COL1) synthesis by cultured low‐passage, human bone‐derived osteoblasts (hOBs) is upregulated in response to estrogen. Cell lines from female donors aged 1 and 66 years were cultured for 11 days on collagen in growth medium supplemented with human serum, hydrocortisone, and β‐glycerophosphate. Young‐donor hOBs grew more quickly than old‐donor hOBs and did not mineralize. Old‐donor hOBs formed mineralized nodules 5 days after reaching confluence. Changes in mRNA levels with time for ERs, type I collagen, and alkaline phosphatase reflected the faster differentiation of the old‐donor cells. The ERβ/ERα ratio fell threefold in young‐donor hOBs but rose 300‐fold in old‐donor hOBs. Increased ERβ/ERα ratios prevented ligand‐dependent downregulation of ERα transcription, resulting in reduced proliferation in old‐donor hOBs. Upregulation of COL1 mRNA expression in response to estrogen was confined to intermediate stages of differentiation, resulting in significant increases in COL1 mRNA by estradiol only in young‐donor cells. Since the young and old‐donor hOBs were cultured under identical conditions, our results indicate that the response of hOBs to estrogen is largely dependent on intracellular mechanisms that control the timing of cellular differentiation. © 2002 Wiley‐Liss, Inc.
A fast annealing evolutionary algorithm for global optimization
Authors: Cai Wensheng , Shao Xueguang
Published: October 2002

By combining the aspect of population in genetic algorithms (GAs) and the simulated annealing algorithm (SAA), a novel algorithm, called fast annealing evolutionary algorithm (FAEA), is proposed. The algorithm is similar to the annealing evolutionary algorithm (AEA), and a very fast annealing technique is adopted for the annealing procedure. By an application of the algorithm to the optimization of test functions and a comparison of the algorithm with other stochastic optimization methods, it is shown that the algorithm is a highly efficient optimization method. It was also applied in optimization of Lennard–Jones clusters and compared with other methods in this study. The results indicate that the algorithm is a good tool for the energy minimization problem. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 427–435, 2002; DOI 10.1002/jcc.10029
Transcription factors C/EBP‐β and ‐δ regulate IL‐6 production in IL‐1β‐stimulated human enterocytes
Authors: Hungness Eric S. , Luo Guang‐ju , Pritts Timothy A. , Sun Xiaoyan , Robb Bruce W. , Hershko Dan , Hasselgren Per‐Olof
Published: October 2002

In recent studies, treatment with IL‐1β of cultured Caco‐2 cells, a human intestinal epithelial cell line, resulted in transcriptional upregulation of IL‐6 production. The role of C/EBP‐β and ‐δ in enterocyte IL‐6 production is not known. Stimulation with IL‐1β of Caco‐2 cells transiently transfected with a luciferase reporter plasmid containing a wild‐type IL‐6 promoter resulted in an approximately 3.5‐fold increase in luciferase activity. This effect of IL‐1β was reduced by approximately 30% when the C/EBP binding site in the IL‐6 promoter was mutated, supporting a role of C/EBP in the regulation of IL‐6 production. When Caco‐2 cells were treated with IL‐1β in the presence of the MAPK inhibitor, PD‐98059, IL‐6 mRNA and protein levels were reduced by the same concentrations of PD‐98059 that inhibited C/EBP DNA binding activity in previous studies. Finally, overexpression of C/EBP‐β and ‐δ in IL‐1β‐treated Caco‐2 cells resulted in a 10–12‐fold increase in IL‐6 production. The results suggest that the β and δ isoforms of the C/EBP family of transcription factors at least in part regulate IL‐6 production in human intestinal epithelial cells. © 2002 Wiley‐Liss, Inc.
Transient and sustained ERK phosphorylation and nuclear translocation in growth control
Authors: Adachi Takahito , Kar Siddhartha , Wang Meifang , Carr Brian I.
Published: October 2002

Growth stimulation and inhibition are both associated with tyrosine phosphorylation. We examined the effects of epidermal growth factor (EGF), a growth stimulant, and compound 5 (Cpd 5), a protein‐tyrosine phosphatase (PTPase) inhibitor, which inhibits the growth of the same Hep3B hepatoma cells. We found that both EGF and Cpd 5 induced tyrosine phosphorylation of EGF receptor (EGFR) and ERK. However, the phosphorylation caused by EGF was transient and that caused by Cpd 5 was prolonged. Furthermore, Cpd 5 action caused a strong nuclear phospho‐ERK signal and induced phospho‐Elk‐1, a nuclear target of ERK activation, in contrast to the weak effects of EGF. An ERK kinase assay demonstrated that ERK activated by Cpd 5 could phosphorylate its physiological substrate, Elk‐1. The MEK inhibitors PD098056 and U0126 abrogated both the induction by Cpd 5 of phospho‐ERK, its nuclear translocation and phospho‐Elk‐1 and also antagonized its growth inhibitory effects. Furthermore, phospho‐ERK phosphatase and phospho‐Elk‐1 activities were lost from nuclear extracts from Cpd 5 treated, but not EGF treated cells. In conclusion, the data show that Cpd 5 causes growth inhibition as a consequence of prolonged ERK and Elk‐1 phosphorylation, likely a result of inhibition of multiple PTPases, including those acting on phospho‐EGFR, on phospho‐ERK, and on phospho‐Elk‐1, in contrast to the kinase driven transient activation resulting from EGF. © 2002 Wiley‐Liss, Inc.
Stress kinase p38 mediates EGFR transactivation by hyperosmolar concentrations of sorbitol
Authors: Cheng Hao , Kartenbeck Jürgen , Kabsch Kirsten , Mao Xiahong , Marqués Margarita , Alonso Angel
Published: October 2002

Activation of the epidermal growth factor receptor (EGFR) has been shown to occur by ligand‐dependent and ligand‐independent mechanisms. Different molecular mechanisms have been found to be responsible for ligand‐independent receptor transactivation. Here, we show that hyperosmolar concentrations of sorbitol activate the EGFR in human keratinocytes. Experiments using specific inhibitors of EGFR phosphorylation show that the increased amount of activated receptors is the result of a decreased rate of dephosphorylation. Furthermore, sorbitol treatment results in a strong activation of stress kinase p38. Treatment of the cells with SB203580, a known inhibitor of p38 α and β kinases, results in impairment of receptor activation, indicating that the stress kinase is involved in receptor activation modulation. This is further reinforced by experiments showing that addition of Toxin B, known to be an inhibitor of the small Rho GTPases rac1, cdc42, and Rho A/B, to the cells results in a strong induction of EGFR activation. Our results point, therefore, to a mechanism by which osmotic shock activates EGFR through the small Rho GTPases‐p38 stress kinase pathway. © 2002 Wiley‐Liss, Inc.
Sonographic evaluation of mammographically detected microcalcifications without a mass prior to stereotactic core needle biopsy
Authors: Cheung Yun‐Chung , Wan Yung‐Liang , Chen Shih‐Cheh , Lui Kar‐Wai , Ng Shu‐Hang , Yeow Kee‐Min , Lee Kam‐Fai , Hsueh Swei
Published: October 2002

Purpose.

The purpose of this prospective study was to evaluate the clinical usefulness of sonographically re‐evaluating areas of microcalcification found mammographically before undertaking stereotactic core needle biopsy (SCNB).

Methods.

Patients with nonpalpable breast lesions appearing as microcalcifications on mammograms and who had been referred to us for SCNB were re‐evaluated sonographically before the procedure. None of the breast lesions had been associated with a density on the mammograms, and the initial sonographic evaluations had been negative. Using the mammograms for correlation, we meticulously re‐evaluated the areas of microcalcifications sonographically using a high‐frequency linear‐array transducer. The sonographic and histopathologic results were then reviewed and correlated. The sonographic findings and visibility of the mammographically detected microcalcifications were analyzed by the 2‐tailed Fisher's exact test and the chi‐square test.

Results.

Sixty‐six patients, who had 68 cases of microcalcifications, were enrolled. Thirteen of the 66 patients underwent surgery, and 9 of the 13 were found to have breast carcinoma. In the sonographic re‐evaluation before SCNB in these 9 patients, an associated soft tissue mass was demonstrated in 5 patients but not in the other 4. Sonographic re‐evaluation also revealed abnormalities in 24 of 68 cases (35.3%), in contrast to the negative findings on the initial sonography. Using the chi‐square test to identify a trend, we found that the percentage of cases that were sonographically visible was highest for clustered benign microcalcifications and lowest for segmental benign microcalcifications (p < 0.0001).

Conclusions.

In breast lesions that appear as microcalcifications without an associated mass on mammograms, pre‐SCNB sonographic re‐evaluation with a high‐frequency transducer can depict microcalcifications, particularly the clustered ones, and can detect small associated masses. Although the absence of a sonographically detectable mass in areas of mammographically detected microcalcifications does not guarantee the absence of cancer, the presence of an associated mass on sonography should warrant close follow‐up in the case of negative results to avoid a delay in the diagnosis of breast carcinoma. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:323–331, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.10074
Metastasis of primitive neuroectodermal tumor to the breast
Authors: Kwak Jin‐Young , Kim Eun‐Kyung , You Jai Kyung , Oh Ki Keun , Hong Soon Won , Kim Se Hoon
Published: October 2002

We performed mammography and sonography on a 49‐year‐old woman who had a mass in her left axilla that had been present for 1 month and who had undergone excision of a primitive neuroectodermal tumor (PNET) on her back 1 year before. Mammography revealed 2 adjacent, dense nodules in the left breast and enlarged lymph nodes, without a fatty hilum or internal microcalcifications, in the left axilla. Sonography showed 2 round to oval, markedly hypoechoic nodules in the left breast and enlarged, markedly hypoechoic lymph nodes, without microcalcifications, in the left axilla. We then performed sonographically guided core biopsy. Histopathologic analysis of the specimens confirmed the presence of PNET in the left breast and axillary lymph nodes. The patient was then treated with chemotherapy. To our knowledge, this report is the first to describe radiologic findings of metastasis of PNET to the breast. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:374–377, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.10076
Pituitary adenylate cyclase‐activating polypeptide induces testicular testosterone synthesis through PGE2 mediation in crested newt, Triturus carnifex
Authors: GOBBETTI ANNA , ZERANI MASSIMO
Published: October 2002

The aim of the present work was to study the possible role of adenylate cyclase‐activating polypeptide (PACAP) 38 in the testicular intracellular mechanism regulating steroidogenesis of crested newt, Triturus carnifex. Gonads were incubated in vitro with PACAP 38 and prostaglandin (PG) E2 alone or with inhibitors of cyclooxygenase (COX), adenylate cyclase (AC), and phospholipase C (PLC) for 30 min and 60 min. PGE2, PGF2α, testosterone, and estradiol‐17β were measured in the culture medium; aromatase (AR) activity and cAMP were assessed in the tissue. PACAP 38 increased PGE2 (30 min and 60 min), estradiol‐17β (60 min), cAMP (60 min), and AR (60 min) but decreased testosterone (60 min). PGE2 increased estradiol‐17β, cAMP, and AR and decreased testosterone at 30 and 60 min.PLC inhibitor counteracted the effects of PACAP 38, while AC inhibitor counteracted these effects except for PGE2 increase. AC inhibitor counteracted the effects of PGE2, while PLC did not. COX inhibitor decreased PGF2α (30 min and 60 min), PGE2 (30 min and 60 min), estradiol‐17β (60 min), cAMP (60 min), and AR (60 min), but increased testosterone (60 min). These in vitro results suggest that, in newt testis, PACAP 38 acts on PLC, inducing the increase of PGE2 which, in turn, acting on AC, increases AR activity with the consequent estradiol‐17β increase and testosterone decrease. © 2002 Wiley‐Liss, Inc.
Immunocytochemical analysis of beta (β) keratins in the epidermis of chelonians, lepidosaurians, and archosaurians
Authors: ALIBARDI LORENZO , SAWYER ROGER H.
Published: October 2002

Beta (β) keratins are present only in the avian and reptilian epidermises. Although much is known about the biochemistry and molecular biology of the β keratins in birds, little is known for reptiles. In this study we have examined the distribution of β keratins in the adult epidermis of turtle, lizard, snake, tuatara, and alligator using light and electron immunocytochemistry with a well‐characterized antiserum (anti‐β1 antiserum) made against a known avian scale type β keratin. In lizard, snake, and tuatara epidermis this antiserum reacts strongly with the beta‐layer, more weakly with the oberhautchen before it merges with the beta‐layer, and least intensely with the mesos layer. In addition, the anti‐β1 antiserum reacts specifically with the setae of climbing pads in gekos, the plastron and carapace of turtles, and the stratum corneum of alligator epidermis. Electron microscopic studies confirm that the reaction of the anti‐β1 antiserum is exclusively with characteristic bundles of the 3‐nm β keratin filaments in the cells of the forming beta‐layer, and with the densely packed electron‐lucent areas of β keratin in the mature bet‐ layer. These immunocytochemical results suggest that the 3‐nm β keratin filaments of the reptilian integument are phylogenetically related to those found in avian epidermal appendages. © 2002 Wiley‐Liss, Inc.
Growth and the poor: a comment on Dollar and Kraay
Authors: Lübker Malte , Smith Graham , Weeks John
Published: October 2002

In a recent paper Dollar and Kraay come to sweeping conclusions about economic growth and the poor. On the basis of empirical work they assert that standard World Bank and IMF policy packages are good for the poor. This paper demonstrates that (i) the empirical work is based on theoretically unsound equations; (ii) the data are seriously flawed; and (iii) the policy variables are not defined appropriately, nor are they tested in a consistent manner. These problems imply that the policy conclusions of the authors are unsafe. Copyright © 2002 John Wiley & Sons, Ltd.
Stereoselective synthesis of L‐[2,3,4,5‐D4] ornithine
Authors: Oba Makoto , Ishihara Teruaki , Satake Hiromi , Nishiyama Kozaburo
Published: October 2002

Synthesis of L‐[2,3,4,5‐D4]ornithine in which all of the diastereotopic hydrogens were stereoselectively labeled with deuterium was investigated. The chirally deuterated 3‐aminopropanal derivative, a key intermediate in this synthesis, was prepared by a catalytic deuteration of an unsaturated γ‐lactone derived for L‐glutamic acid followed by several functional group interconversions. Condensation of the obtained deuterium‐labeled 3‐aminopropanal derivative with a chiral glycine template afforded unsaturated ornithine. The dehydroornithine was then subjected to a catalytic deuteration followed by deprotection to give the L‐[2,3,4,5‐D4]ornithine. Copyright © 2002 John Wiley & Sons, Ltd.
Ultrastructure of spermatozoa of the lizard Ameiva ameiva, with considerations on polymorphism within the family Teiidae (Squamata)
Authors: Giugliano L.G. , Teixeira R.D. , Colli G.R. , Báo S.N.
Published: October 2002

A detailed description of sperm ultrastructure of the lizard Ameiva ameiva (Teiidae) is provided. Mature spermatozoa are characterized by: a depressed acrosome at the anterior portion; a unilateral ridge at the anterolateral portion; an acrosome vesicle divided into cortex and medulla; medulla divided into two regions with different electron‐densities; paracrystalline subacrosomal material with radial organization in transverse section; a pointed prenuclear perforatorium; a stopper‐like perforatorium base plate that appears embedded in the subacrosomal material; the presence of an epinuclear lucent zone surrounded by its own membrane; a large nuclear rostrum; round nuclear shoulders; a nuclear space at the nucleus tip; a bilateral stratified laminar structure; a central dense body within the proximal centriole; a short midpiece; an axonemal midpiece axial component; peripheral fibers 3 and 8 grossly enlarged at the anterior portion of axoneme; columnar mitochondria with linear cristae; solid dense bodies arranged as rings or spirals; a triangular‐shaped annulus in transverse section; a fibrous sheath into the midpiece; a thin zone of cytoplasm at the anterior portion of the principal piece; and a slight decrease in diameter of the principal piece immediately after the annulus. Comparisons with Cnemidophorus sexlineatus and Micrablepharus maximiliani failed to identify unique sperm ultrastructure traits of Teiidae or Teiioidea (Teiidae + Gymnophthalmidae). High levels of polymorphism between Ameiva and Cnemidophorus, two closely related genera of the family Teiidae, were detected, suggesting that extensive sampling within squamate families is essential if sperm ultrastructure data are to be used in phylogenetic analyses at this taxonomic level. J. Morphol. 253:264–271, 2002. © 2002 Wiley‐Liss, Inc.
Axillary lymph node metastases: A statistical analysis of various parameters in MRI with USPIO
Authors: Stets Constanze , Brandt Silvio , Wallis Fintan , Buchmann Jörg , Gilbert F.J. , Heywang‐Köbrunner Sylvia H.
Published: October 2002

Purpose

To assess the value of plain vs. iron oxide‐enhanced MRI vs. the combined study (plain + postcontrast) based on qualitative and quantitative parameters of three pulse sequences.

Materials and Methods

Data from two sites were acquired using the same technique; therefore, this data could be pooled. T1W‐SE, T2W‐FSE, and 3D‐PSIF were used before and 24–36 hours after MRI with ultra small particles of iron oxide (USPIO) was performed. A total of 52 lymph nodes (LNs) in nine patients (25 benign, 27 malignant) were evaluated by two readers who were visually and quantitatively blinded to the histology. Combinations of the following diagnostic parameters were compared using logistic regression analysis: the short‐axis diameter of the LN, the signal distribution of the LN on postcontrast agent MRI (homogeneous or heterogeneous), and qualitatively and quantitatively determined signal changes of the LN following administration of contrast agent in the three evaluated sequences.

Results

Using pre‐ and postcontrast data, the optimized accuracy based on the statistically most significant parameters (LN diameter > 6 mm, visual assessment of signal change on T2W‐SE) was 87% (81% sensitivity, 92% specificity). Precontrast data alone yielded 75% accuracy (63% sensitivity, 86% specificity). Postcontrast data alone yielded 75% accuracy (56% sensitivity, 96% specificity).

Conclusion

Based on our results, USPIO‐MRI improved the diagnosis of metastatic axillary LNs compared with precontrast MRI alone. Both pre‐ and postcontrast studies are needed. T1W‐SE and T2W‐PSIF did not yield significant additional information. This study may help to further improve the technique of USPIO imaging. J. Magn. Reson. Imaging 2002;16:60–68. © 2002 Wiley‐Liss, Inc.
Imaging inflammation: Direct visualization of perivascular cuffing in EAE by magnetic resonance microscopy
Authors: Gareau Paula J. , Wymore Allison C. , Cofer Gary P. , Johnson G. Allan
Published: October 2002

Purpose

To determine if the architectural features revealed by magnetic resonance microscopy (MRM) allow one to detect microscopic abnormalities associated with neuroinflammation in fixed brain sections from animals with experimental allergic encephalomyelitis (EAE), an animal model for multiple sclerosis (MS).

Materials and Methods

Imaging was performed at the Center for In Vivo Microscopy (CIVM) using a 9.4‐Tesla, 89‐mm bore, superconducting magnet with actively shielded gradients capable of 850 mT/m. A number of MR contrasts and spatial resolutions were explored.

Results

The assessment of EAE brain showed that it is possible to visualize perivascular cuffing in vitro by MRM on three‐dimensional T1 proton stains.

Conclusion

Inflammatory cell infiltration is a prerequisite for the development of lesions in EAE and MS. Thus, the ability to directly detect individual perivascular cuffs of inflammation may provide a useful means of monitoring the time course of inflammatory events, as conventional histopathological scoring of perivascular cuffs is utilized, but in the absence of sectioning and staining. J. Magn. Reson. Imaging 2002;16:28–36. © 2002 Wiley‐Liss, Inc.
Sequential diffusion‐weighted magnetic resonance imaging study of lysophosphatidyl choline‐induced experimental demyelinating lesion: An animal model of multiple sclerosis
Authors: Degaonkar Mahaveer N. , Jayasundar Rama , Jagannathan Naranamangalam R.
Published: October 2002

Purpose

To differentiate the surrounding edema from the focal demyelinating lesion during the early phase of the lesion using an apparent diffusion coefficient (ADC), and to monitor the changes in ADCs during the complete progression of a lysophosphatidyl choline (LPC)‐induced experimental demyelinating lesion, an animal model of multiple sclerosis (MS).

Material and Methods

Eighteen rats divided into two groups—demyelinating lesion (group I, N = 12) and vehicle group (saline injected; group II, N = 6)—were studied. A 0.2‐μl quantity of 1% LPC solution in isotonic saline was injected in the rat brain internal capsule (IC) area to create the demyelinating lesion. Six rats were used exclusively for histology. Diffusion‐weighted (DW) images were acquired at different diffusion weightings on the 3rd, 5th, 10th, 15th, and 20th days after LPC injection. ADC was measured from three regions of interest (ROIs) within the IC: focal demyelinating lesion (area A), surrounding area of the lesion (area B), and contralateral IC area (area C).

Results

Histology revealed demyelination of the IC area during the early phase of lesion progression up to day 10 and remyelination thereafter. Elevated ADCs were observed for the surrounding edematous area (area B), compared to the focal demyelinating lesion (area A) during the early phase of the demyelination process, while substantial reduction of ADCs was noticed during remyelination for both regions.

Conclusion

Measurement of ADC showed clear differentiation of the surrounding edema from the LPC‐induced focal demyelinating lesion in rats, especially during the early phase of the lesion progression. J. Magn. Reson. Imaging 2002;16:153–159. © 2002 Wiley‐Liss, Inc.
Evaluation of a new ultrasmall superparamagnetic iron oxide contrast agent Clariscan®, (NC100150) for MRI of renal perfusion: Experimental study in an animal model
Authors: Bachmann Rainald , Conrad Rudolf , Kreft Burkhard , Luzar Oliver , Block Wolfgang , Flacke Sebastian , Pauleit Dirk , Träber Frank , Gieseke Jürgen , Saebo Karin , Schild Hans
Published: October 2002

Purpose

To determine the diagnostic value of a new ultrasmall superparamagnetic iron oxide Clariscan®, (NC100150) for the evaluation of renal perfusion in an animal model using a 3D‐FFE‐EPI sequence.

Materials and Methods

Four groups of four rabbits each were imaged after bolus injection of NC100150, using a 1.5 T MR system (Gyroscan ACS‐NT). T2*w MR images in the coronal plane were acquired over 60 seconds with an echo‐shifted 3D‐FFE‐EPI sequence (TR/TE/α = 18/25 msec/8°). Data were transferred to a workstation and converted into concentration curves. Based on the fitted concentration time curves, parameter maps were calculated pixelwise: bolus arrival time (T0), time‐to‐peak (TTP), mean transit time (MTT), and relative bolus volume (rBV). Maximum signal decrease was determined with respect to the baseline value.

Results

Mean MTT increased from 4.2 seconds at a dose of 0.25 mg to 5.9 seconds at 1.0 mg (P < .0001). The maximum signal decrease was observed at 0.75 mg, corresponding to 85% of the baseline value. Transit times of the contrast bolus were accurately calculated for the cortex and the outer medulla, but at the level of the inner medulla no arterial flow profile was identified. No significant difference between the cortex and the outer medulla was found for either T0 or rBV, but medullar TTP and MTT were prolonged with regard to cortical TTP and MTT (6.3 seconds vs. 5.7 seconds, P < .001; 5.7 seconds vs. 4.2 seconds, P < .0001).

Conclusion

The employed intravascular contrast agent is well suited to assess renal perfusion. By the use of a T2*w3D perfusion sequence, cortical and medullar transit times can be quantified and physiologic information on regional perfusion differences can be obtained. J. Magn. Reson. Imaging 2002;16:190–195. © 2002 Wiley‐Liss, Inc.
Frequency of Epstein‐Barr virus‐specific cytotoxic T lymphocytes in the blood of Southern Chinese blood donors and nasopharyngeal carcinoma patients
Authors: Whitney Bruce M. , Chan Anthony T.C. , Rickinson Alan B. , Lee Steven P. , Lin C.K. , Johnson Philip J.
Published: October 2002

Undifferentiated nasopharyngeal carcinoma is very common among Southern Chinese. While most patients have the disease detected and treated early, those who are diagnosed with advanced stages face a poor prognosis. Nasopharyngeal carcinoma is associated with latent Epstein‐Barr virus (EBV); it was suggested previously that a cytotoxic T‐lymphocyte (CTL)‐based therapy targeting EBV proteins may offer a possible new form of treatment for this disease. The most likely target of this treatment is latent membrane protein 2 (LMP2). To define further the preexisting level of anti‐EBV immunity in Chinese subjects, the frequency of peripheral blood mononuclear cells (PBMCs) responding to peptide epitopes was determined using an ELISPOT assay in 50 healthy control blood donors and in 26 patients newly diagnosed with nasopharyngeal carcinoma. A total of 7 LMP2, 2 LMP1, 1 EBNA3A, and 1 EBNA3B epitopes were used in a HLA‐restricted manner. As reported previously for healthy virus carriers in western countries, it was found that in both groups the strongest responses were to epitopes in the EBNA proteins with weaker responses to the LMP epitopes. It was found that LMP2 epitopes were recognized in a greater percentage of both groups than previously reported, due most likely to the greater sensitivity of the ELISPOT method. However, patients with nasopharyngeal carcinoma demonstrated a weaker response than that displayed by healthy control subjects to several epitopes. The results demonstrate that LMP2 epitopes are recognized widely in an HLA‐restricted manner in patients with nasopharyngeal carcinoma and that immunotherapy to boost preexisting immunity to these epitopes may offer a viable method to treat such patients or to protect against recurrence. J. Med Virol. 67:359–363, 2002. © 2002 Wiley‐Liss, Inc.
Viral determinants and host immune responses in the pathogenesis of HBV infection
Authors: Rapicetta Maria , Ferrari Carlo , Levrero Massimo
Published: October 2002

Hepatitis B virus (HBV) is a virus that infects about 350,000,000 people worldwide with a clinical spectrum of acute hepatitis, the healthy carrier state, cirrhosis and hepatocellular carcinoma (HCC). The outcome of HBV infection is the result of complicated viral‐host interactions. As in other infections with non‐cythopatic viruses, the immune response is thought to play a crucial role in disease pathogenesis but there is increasing evidence that a variety of viral mechanisms, some depending on the function of virally encoded proteins, have a profound impact on the infected hepatocytes, the liver microenvironment, and host anti‐viral responses. Indeed, the virus has evolved multiple mechanisms to ensure its success in infecting a susceptible host. The essential aspects of the life cycle of HBV and the host immune response are reviewed and recent new developments in the molecular virology of HBV, including experimental animal models, in the role of accessory viral proteins in disease pathogenesis and HCC development and in the characterisation of the T cell response in the control of HBV infection, are highlighted. J. Med. Virol. 67:454–457, 2002. © 2002 Wiley‐Liss, Inc.
Bone marrow transplantation in a child with Wiskott‐Aldrich syndrome latently infected with acyclovir‐resistant (ACVr) herpes simplex virus type 1: Emergence of foscarnet‐resistant virus originating from the ACVr virus
Authors: Saijo Masayuki , Yasuda Yukiharu , Yabe Hiromasa , Kato Shunichi , Suzutani Tatsuo , De Clercq Erik , Niikura Masahiro , Maeda Akihiko , Kurane Ichiro , Morikawa Shigeru
Published: October 2002

A human leukocyte antigen (HLA)‐matched unrelated bone marrow transplantation (BMT) was performed in a 13‐year‐old patient with the congenital immunodeficiency syndrome, Wiskott‐Aldrich syndrome. The patient had a history of acyclovir (ACV)‐resistant (ACVr) herpes simplex virus type 1 (HSV‐1) infections prior to BMT. After BMT, the skin lesions caused by HSV‐1 relapsed on the face and genito‐anal areas. Ganciclovir (GCV) therapy was initiated, but the mucocutaneous lesions worsened. An HSV‐1 isolate recovered from the lesions during this episode was resistant to both ACV and GCV. The ACVr isolate was confirmed to have the same mutation in the viral thymidine kinase (TK) gene as that of the previously isolated ACVr isolates from the patient. After treatment switch to foscarnet (PFA), there was a satisfactory remission but not a complete recovery. Although the mucocutaneous lesions improved, a PFA‐resistant (PFAr) HSV‐1 was isolated 1 month after the start of PFA therapy. The PFAr HSV‐1 isolate coded for the same mutation in the viral TK gene as the ACVr HSV‐1 isolates. Furthermore, the PFAr isolate also expressed a mutated viral DNA polymerase (DNA pol) with an amino acid (Gly) substitution for Val at position 715. This is the first report on the clinical course of a BMT‐associated ACVr HSV‐1 infection that subsequently developed resistance to foscarnet as well. J. Med. Virol. 68:99–104, 2002. © 2002 Wiley‐Liss, Inc.
Detection and differentiation of Norwalk virus by reverse transcription‐polymerase chain reaction and enzyme‐linked immunosorbent assay
Authors: Tatsumi Masatoshi , Nakata Shuji , Sakai Yoshiyuki , Honma Shinjiro , Numata‐Kinoshita Kazuko , Chiba Shunzo
Published: October 2002

We have developed a reverse transcription‐polymerase chain reaction and enzyme‐linked immunosorbent assay (RT‐PCR–ELISA), using genetic cluster‐specific probes in a microtiter plate format, for the detection and differentiation of Norwalk virus (NV) in stool samples. The specificity of the RT‐PCR–ELISA was confirmed by testing 76 stool specimens and 15 tissue culture fluids derived from growths of unrelated viruses. The sensitivity of the RT‐PCR–ELISA was compared with conventional PCR and Southern hybridization by testing the four cDNA clones derived from the RNA‐dependent RNA polymerase region of the NV68 (NV/GI) virus and viruses in the NV/GII/P1B, the NV/GII/P2A, and the NV/GII/P2B cluster. This assay was as sensitive as the conventional RT‐PCR with Southern hybridization regardless of primer pairs and probes used in the experiments. However, the actual sensitivity of this method was higher when clinical stool samples were examined because this assay examines all the samples irrespective of the RT‐PCR results. The RT‐PCR–ELISA format is simple, time saving, and suitable for testing many samples. It should be reliable for large‐scale epidemiological studies of NV. J. Med. Virol. 68: 285–290, 2002. © 2002 Wiley‐Liss, Inc.
Role of long‐range repulsive forces in organizing axonal neurofilament distributions: Evidence from mice deficient in myelin‐associated glycoprotein
Authors: Kumar Sanjay , Yin Xinghua , Trapp Bruce D. , Paulaitis Michael E. , Hoh Jan H.
Published: October 2002

When the axon of a motor neuron is sectioned and visualized by electron microscopy, a two‐dimensional distribution of neurofilaments (NFs) with nonrandom spacing is revealed; this ordered arrangement implies the presence of physical interactions between the NFs. To gain insight into the molecular basis of this organization, we characterized NF distributions from mouse sciatic nerve cross sections using two statistical mechanical measures: radial distribution functions and occupancy probability distributions. Our analysis shows that NF organization may be described in terms of effective pairwise interactions. In addition, we show that these statistical mechanical measures can detect differences in NF architecture between wild‐type and myelin‐associated glycoprotein null mutant mice. These differences are age dependent, with marked contrast between the NF distributions by 9 months of age. Finally, using Monte Carlo simulations, we compare the experimental results with predictions for models in which adjacent NFs interact through rigid cross bridges, deformable cross bridges, and long‐range repulsive forces. Among the models tested, a model in which the filaments interact through a long‐range repulsive force is most consistent with the results of our analysis. © 2002 Wiley‐Liss, Inc.
Expression of the myelin and oligodendrocyte progenitor marker sulfatide in neurons and astrocytes of adult rat brain
Authors: Pernber Zarah , Molander‐Melin Marie , Berthold Claes‐Henric , Hansson Elisabeth , Fredman Pam
Published: October 2002

Sulfatide is a myelin component of the central (CNS) and peripheral nervous system (PNS) and is used extensively to identify oligodendrocyte progenitor cells. We have explored sulfatide expression in CNS gray matter (cerebellum, cerebral cortex, and hippocampus) and the PNS in adult rats using an anti‐sulfatide antibody (Sulph I) and confocal microscopy. Biochemical analyses revealed two Sulph I antigens, sulfatide and seminolipid; sulfatide was present at about five times higher concentration, and the affinity of Sulph I for sulfatide was 2.5 times higher than that for seminolipid. Thus sulfatide was considered the dominant antigen. We found Sulph I immunostaining, in addition to that in myelinated areas in subpopulations of astrocytes and neurons. Astrocyte Sulph I staining was localized to the cell bodies and in some cases also to the processes. In the cerebellum, some Sulph I‐positive astrocytes corresponded to Golgi epithelial cell bodies. We also found Sulph I staining in neuronal cell bodies, which in some neurons was clearly localized to the cytoplasm and in others to the nuclear membrane. Sulph I immunostaining in the PNS was located in the myelin sheath and paranodal end segments. These results demonstrate the expression of sulfatide in cell types other than oligodendrocytes and Schwann cells, showing that sulfatide is not a selective marker for adult oligodendrocyte progenitor cells. Moreover, these findings show that sulfatide is localized also to intracellular compartments and indicate that other roles of sulfatide in astrocytes and neurons, compared to myelin, might be considered. © 2002 Wiley‐Liss, Inc.
Androgen receptor messenger RNA and protein in adult rat sciatic nerve: Implications for site of androgen action
Authors: Jordan Cynthia L. , Price Richard H. , Handa Robert J.
Published: October 2002

Gonadal androgens exert a wide variety of effects on several neuromuscular systems, including controlling the developmental fate of motoneurons and neuromuscular synapses and promoting the growth of adult dendrites and axons. Paramount in understanding the molecular mechanisms behind androgen action is determining where androgen acts; does androgen act directly or indirectly on cells to change their fate and function? One step toward answering this question has been to determine which cells express androgen receptors (ARs). Motoneurons and skeletal muscles both have ARs and are, therefore, potential sites of androgen action. Recent evidence indicates that the sciatic nerve in rats also contains AR mRNA (Magnaghi et al. [1999] Brain Res. Mol. Brain Res. 70:36–44), although which cell type expresses ARs remains unanswered. In this study, we explored the question of which cell populations in the rat sciatic nerve express ARs. Using immunocytochemistry and reverse transcriptase‐PCR, we confirmed the presence of AR protein and mRNA in sciatic nerve from adult rats and found a sex difference, favoring males, in the number of cell nuclei immunopositive for AR. This difference was not due to a sex difference in the overall number of cell nuclei. We also found a difference favoring males in AR mRNA, evidence also suggesting that AR expression is higher in males than in females. Results from double‐immmunolabeling experiments in sciatic nerve from adult males suggest that, within the endoneurial compartment, endoneurial fibroblasts stain prominently for AR, with some endothelial cells also AR+. Although Schwann cells showed light AR immunostaining, this staining is apparently nonspecific. We conclude that cells within peripheral nerve have ARs and may, therefore, mediate some of the effects of androgens on neuromuscular systems. © 2002 Wiley‐Liss, Inc.
Introduction to the brave new workplace: organizational behavior in the electronic age
Authors: Gephart Robert P.
Published: October 2002

This paper provides an overview of the nature and meaning of organizational behavior in the electronic age. I review objectives and questions addressed by the Special Issue on Brave New Workplace. Next, I review literature on new work, new workers and the new workplace which provides the context for the Special Issue and its contributions. Specifically, I review literature on features of ‘the new modernism’ in society. I relate macro level social trends and globalization to the political economy of workplace risks. Four themes which characterize new work and work settings are addressed: electronic work, self‐management, individualization of risks, and the inversion of the gender characteristics at work and home. Social implications of new work are explored, including implications which new work practices and new modernist institutions hold for the family, for gender relations and for communities. I conclude by discussing how papers in the current volume contribute to understanding key issues in the brave new workplace. Copyright © 2002 John Wiley & Sons, Ltd.
Telecommuting, professional isolation, and employee development in public and private organizations
Authors: Cooper Cecily D. , Kurland Nancy B.
Published: October 2002

This study employs a grounded theory methodology to compare the impact telecommuting has on public and private employees perceptions of professional isolation. It relied on 93 semi‐structured interviews with telecommuters, non‐telecommuters, and their respective supervisors in two high technology firms and two city governments. These organizations had active telecommuting programmes and a strong interest in making telecommuting a successful work option, providing an opportunity to investigate the challenges of telecommuting that existed even within friendly environments. The interviews demonstrated that professional isolation of telecommuters is inextricably linked to employee development activities (interpersonal networking, informal learning, and mentoring). The extent to which telecommuters experience professional isolation depends upon the extent to which these activities are valued in the workplace and the degree to which telecommuters miss these opportunities. Public respondents appeared to value these informal developmental activities less than private employees. Therefore, we stipulate that telecommuting is less likely to hinder the professional development of public sector employees than that of employees in the private sector. Copyright © 2002 John Wiley & Sons, Ltd.
Boundaryless and traditional contingent employees: worlds apart
Authors: Marler Janet H. , Woodard Barringer Melissa , Milkovich George T.
Published: October 2002

We find support for distinguishing between two types of contingent workers: boundaryless and traditional. The existence of these two types helps explain the conflicting views about contingent work in the literature. Using hierarchical cluster and multivariate analysis on a national survey of 614, and a regional sample of 276 temporary employees, we also find that these two types exhibit different work attitudes and behaviors. What distinguishes boundaryless temporaries from others is their preference for temporary work and level of skill and experience. Results also show that the performance of traditional temporaries is more sensitive to attitudes than boundaryless temporaries. After controlling for level of work satisfaction, traditional temporaries reported higher task and contextual performance. We discuss the implications of these findings for theory development, organization practice and public policy. Copyright © 2002 John Wiley & Sons, Ltd.
An empirical assessment of the loose–tight leadership model: quantitative and qualitative analyses
Authors: Sagie Abraham , Zaidman Nurit , Amichai‐Hamburger Yair , Te'eni Dov , Schwartz David G.
Published: October 2002

Using questionnaire and interview data, this study attempted to find out whether the organizational loose (participative) and tight (directive) practices are compatible with or contradict each other. Using the theoretical framework of Sagie's (1997) loose–tight leadership approach, our hypotheses concerned the effects of both practices on the employee's work‐related attitudes, and the mediating role of two variables, cognitive (information sharing) and motivational (exerting effort), in these effects. Data were analysed using two methodological approaches, quantitative and qualitative. Based on a quantitative analysis of the questionnaires given to 101 professional employees of a textile company, partial support was provided for the study hypotheses. A qualitative analysis of in‐depth, semi‐structured interviews with all the employees (n = 20) in one of the company divisions led to similar conclusions. Specifically, we found that although the loose and tight practices affected work attitudes, the interviewees attributed more impact to the tight practice. In addition, none of the study variables mediated the loose impact on attitudes, whereas information sharing (but not exerting effort) mediated the influence of tight practice. Finally, the qualitative analysis revealed a deeper insight into the nature of both leader practices and their possible integration in the decision‐making processes in organizations. Copyright © 2002 John Wiley & Sons, Ltd.
A 19th century climate chronology for the Kalahari region of central southern Africa derived from missionary correspondence
Authors: Nash David J. , Endfield Georgina H.
Published: October 2002

Unpublished materials written by missionaries based at London Missionary Society and Wesleyan Methodist Missionary Society mission stations across the Kalahari region have been used as the primary source for the construction of a historical climatic chronology for central southern Africa for the period 1815–1900. Data from these unpublished documents were supplemented by analyses of published material written by various hunters and explorers (as well as missionaries) who travelled beyond the immediate areas of missionary activity. Key features of the climate chronology are the identification of six drought episodes and seven periods of above‐average rainfall which affected various parts of the region. Major dry periods occurred in 1820–27, 1831–35, 1844–51, 1857–65, 1877–86 and 1894–99, of which the droughts in 1844–51, 1857–65, 1884–86 and 1894–99 were the most widespread. Wetter periods are identified in 1816–17, 1829–30, 1851–52, 1863–64, 1874–75, 1889–91 and 1899–1900, with the most widely distributed wet conditions occurring in 1889–91. In order to ascertain the reliability of the chronology, the document‐derived climate sequence has been compared with available meteorological data for the study area (from Barkly West for the period 1883–1900) and shows good general agreement.

The results of this study have been compared with historical climate chronologies for the former Cape Province of South Africa. This comparison reveals that large areas of the southern African subcontinent experienced dry conditions in 1826–27, 1832–35, 1848–1851, 1858–60, 1861–63, 1877–81, 1884–86 and 1894–99, with the dry phases of the early 1850s, 1858–60, 1861–63 and 1894–99 possibly extending beyond the northern border of present‐day Botswana. Wetter phases affected much of the subcontinent in 1829–30, 1851–52, 1863–64, 1874–75, 1889–91 and 1899–1900, with 1874–75 and 1889–91 associated with reports of flooding from central Botswana to the eastern Cape. The causal mechanisms of patterns of climatic variability are unclear, but 19th century drought periods in the Kalahari show a close coincidence with the timing of moderate to strong El Niño–southern oscillation events Copyright © 2002 Royal Meteorological Society
Non‐destructive method for the quantification of the average particle diameter of latex as water‐based emulsions by near‐infrared Fourier transform Raman spectroscopy
Authors: Ito Kazuhiro , Kato Tadaya , Ona Toshihiro
Published: October 2002

Vibrational spectroscopy is utilized to characterize compounds, but it has never been applied to quantitative morphological analysis of polymers in a mass. By using near‐infrared Fourier transform Raman spectroscopy coupled with multivariate data analysis, the average particle diameter of macroscopic size in water‐based latex emulsions was successfully quantified with correlation coefficients >0.95, both in calibration (known samples, n = 36) and in prediction (unknown samples, n = 11) against conventionally measured values obtained by the dynamic laser diffraction scattering method. This method is valid for samples of various monomer compositions together with various fluorescence and Rayleigh scattering intensities causing different background levels in the spectra. Copyright © 2002 John Wiley & Sons, Ltd.