bluuebunny/crossref_metadata_2025 huggingface dataset:
Capillary electrochromatography with monolithic silica column: I. Preparation of silica monoliths having surface‐bound octadecyl moieties and their chromatographic characterization and applications to the separation of neutral and charged species
Authors: Allen Darin , El Rassi Ziad
Published: February 2003

Monolithic silica columns with surface‐bound octadecyl (C18) moieties have been prepared by a sol‐gel process in 100  μm ID fused‐silica capillaries for reversed‐phase capillary electrochromatography of neutral and charged species. The reaction conditions for the preparation of the C18‐silica monoliths were optimized for maximum surface coverage with octadecyl moieties in order to maximize retention and selectivity toward neutral and charged solutes with a sufficiently strong electroosmotic flow (> 2 mm/s) to yield rapid analysis time. Furthermore, the effect of the pore‐tailoring process on the silica monoliths was performed over a wide range of treatment time with 0.010 M ammonium hydroxide solution in order to determine the optimum time and conditions that yield mesopores of narrow pore size distribution that result in high separation efficiency. Under optimum column fabrication conditions and optimum mobile phase composition and flow velocity, the average separation efficiency reached 160 000 plates/m, a value comparable to that obtained on columns packed with 3  μm C18‐silica particles with the advantages of high permeability and virtually no bubble formation. The optimized monolithic C18‐silica columns were evaluated for their retention properties toward neutral and charged analytes over a wide range of mobile phase compositions. A series of dimensionless retention parameters were evaluated and correlated to solute polarity and electromigration property. A dimensionless mobility modulus was introduced to describe charged solute migration and interaction behavior with the monolithic C18‐silica in a counterflow regime during capillary electrochromatography (CEC )separations. The mobility moduli correlated well with the solute hydrophobic character and its charge‐to‐mass ratio.
An exactly solvable Ogston model of gel electrophoresis: X. Application to high‐field separation techniques
Authors: Gauthier Michel G. , Slater Gary W.
Published: February 2003

Recently, we generalized our lattice model of gel electrophoresis to study the net velocity of particles being pulled by a high‐intensity electric field through an arbitrary distribution of immobile obstacles (Gauthier, M. G., Slater, G. W., J. Chem. Phys. 2002, 117, 6745–6756). In this article, we show how the high‐field version of our model can be used to compare the velocity of particles with different electric charges and/or physical sizes. We then investigate specific two‐dimensional distributions of obstacles that can be used to separate particles, e.g., in a microfluidic device. More precisely, we compare the velocity of differently charged or sized analytes in sieving, trapping and deflecting systems to model various electrophoretic separation techniques. In particular, we study the nonlinear effects present in ratchet systems and how they can be combined with time‐asymmetric pulsed fields to provide new modes of separation.
Integrated on‐capillary instrumentation for gene expression measurement directly from cells
Authors: Matsunaga Hiroko , Anazawa Takashi , Yeung Edward S.
Published: February 2003

We studied the fundamental instrumental issues relevant to a capillary‐based integrated system to measure expression of a specific gene directly from cells. Samples were introduced into a capillary by use of a syringe pump. All reactions were carried out in a microthermocycler, where a part of the capillary having 1 μL inner volume was used as a reaction vessel. First, cells were lysed by heating to release RNA, followed by deoxyribonuclease (DNase) treatment. Then, reverse transcription‐polymerase chain reaction (RT‐PCR) was performed to obtain amplified products from the targeted mRNA. Finally, the product was verified by capillary electrophoresis (CE) with laser‐induced fluorescence detection. The whole protocol was completed in the system in 3 h. PCR product from β‐actin mRNA in 16 human lymphoblast cells was obtained with a signal‐to‐noise ratio (S/N) of 3400 ± 730 (n = 3). Therefore, the system is reproducible and sensitive enough to measure gene expression from a single cell. We show that the amplified fragment from breast cancer‐specific mRNA was obtained from cells of breast cancer cell line, but was not obtained from cells of hepatoma cell line. These results therefore lay the foundations for future CE or microchip instrumentation for high‐throughput automated gene‐expression analysis.
Product Design in Food Industry Using the Example of Emulsification
Authors: Schuchmann H.P. , Schubert H.
Published: February 2003

Designing a product according to the consumers’ needs is one of the key targets in food industry. Having once defined the target product properties, it is of imperative importance to know which microstructure of the product is required (property function) and how the target microstructure can then be determined by process parameters (process function). Many food products are emulsions, either during production and/or in the moment of distribution and consumption. This review intends to depict the design of emulsions according to target needs. Even if we concentrate on typical food emulsions as an example, the concept can be widely applied, since emulsification in other branches of industry is governed by the same principles.
Hydrothermal Oxidation of Oily Wastes: an Alternative to Conventional Treatment Methods
Authors: Portela J.R. , Sanchez‐Oneto J. , López J. , Nebot E. , Martínez de la Ossa E.
Published: February 2003

Under current legislations most oils used are considered hazardous wastes and its safe collection and disposal must be ensured. Since conventional treatment methods are often inefficient or environmentally unacceptable, the development and application of new technologies is highly necessary. Wet Air Oxidation (WAO) and Supercritical Water Oxidation (SCWO) are two forms of hydrothermal oxidation that have been proved to be effective processes to treat a wide variety of industrial wastes, but they have hardly been tested for oily wastes. In this work, the suitability of hydrothermal oxidation to the treatment of oily wastewaters is described by the results obtained with three different substrates: free fatty acids, cutting oils and bilge wastes. The efficiency of the treatment process is demonstrated for the three oily wastes tested. At temperatures below 350 °C and reaction times of 40 minutes, a 70‐‐90 % of COD elimination is achieved, obtaining an effluent with low molecular weight compounds, mainly carboxylic acids. At 500 °C, a 99 % of COD removal is achieved in less than one minute. At this temperature the reaction seems to proceed mainly through total mineralization to carbon dioxide and water.
Commentary: A Success Story Continued
Authors: Schwarz Helmut
Published: February 2003

As the nucleus of structured doctoral training, “Graduiertenkollegs” (Research Training Groups) have contributed greatly to improve doctoral studies in general
The Ozonolysis of Longifolene: A Tool for the Preparation of Useful Chiral Compounds. Configuration Determination of New Stereogenic Centers by NMR Spectroscopy and X‐Ray Crystallography
Authors: Dimitrov Vladimir , Hopp Rentsch Gudrun , Linden Anthony , Hesse Manfred
Published: February 2003

The ozonolysis of (+)‐longifolene (1) in different solvents (Et2O, CH2Cl2, CHCl3, acetone) at −80° provided quantitatively longifolene epoxide (3) as a single diastereoisomer in which the O‐atom is endo‐positioned (Scheme 2). Upon warming to room temperature, the epoxide remained stable only in acetone and was isolated as a low‐melting crystalline compound. In CH2Cl2, Et2O, or CHCl3 solution, epoxide 3 rapidly rearranged to the isomeric enols 4 and 5, which underwent further rearrangement to give the exo‐aldehyde 6. On standing for several weeks in CH2Cl2 solution, or in CHCl3 and Et2O as well, at room temperature, aldehyde 6 slowly rearranged into its epimer 7. The aldehydes 6 and 7 were isolated on the preparative scale for further synthetic use. The addition of methylmagnesium iodide to 6 and 7 provided the corresponding alcohols 13/14 and 15/16, respectively, which were isolated as pure diastereoisomers (Scheme 4). The configurations of the new chiral centers in 13–16 were determined by NMR methods and X‐ray crystallography.
Conodirinines A and B, Novel Vobasine‐Iboga Bisindoles Incorporating an Additional Tetrahydro‐1,3‐oxazine Unit on the Vobasinyl Moiety
Authors: Kam Toh‐Seok , Sim Kooi‐Mow
Published: February 2003

Two novel bisindole alkaloids of the vobasine‐Iboga type, viz., conodirinines A and B, in which the vobasinyl unit has incorporated an additional tetrahydrooxazine ring, were obtained from the leaf extract of the Malayan species Tabernaemontana corymbosa, and their structures were established by spectroscopic analysis.
X‐Ray Crystal Structure Analysis of Oxindole Alkaloids
Authors: Laus Gerhard , Wurst Klaus
Published: February 2003

The single‐crystal X‐ray structures of speciophylline, mitraphylline, and rhynchophylline, oxindole alkaloids from the Peruvian climbing vine Uncaria tomentosa (Rubiaceae), were determined. The three compounds show N⋅⋅⋅HN hydrogen bonding, which has not been observed in the crystal structures of the related alkaloids pteropodine and isopteropodine. In the tetracyclic alkaloid rhynchophylline, the side chain is rotated out of the ring plane into a position perpendicular to it. This is in contrast to the situation of the pentacyclic analogue mitraphylline, which possesses a conformationally rigid tricyclic core. This conformational difference possibly causes the competitive antagonism of these two types of alkaloids.
Multistep Parallel Synthesis of Quinazoline‐2,4‐diones by a Fluorous Biphasic Concept without Perfluorinated Solvents
Authors: Schwinn Dominik , Glatz Heiko , Bannwarth Willi
Published: February 2003

Based on perfluoro‐tagged benzyl alcohol adsorbed via fluorous–fluorous interactions on fluorous reversed‐phase silica gel (FRPSG), we have performed a multistep synthesis leading finally to a small library of quinazoline‐2,4‐diones. The whole reaction sequence runs without isolation of intermediates and most importantly, without the need of perfluorinated solvents.
Ein neuer Zugang zu 2′‐O‐(2‐Methoxyethyl)ribonucleosiden ausgehend von D‐Glucose
Authors: Martin Pierre
Published: February 2003

A New Access to 2′‐O‐(2‐Methoxyethyl)ribonucleosides Starting from D‐Glucose

A new synthesis of 2′‐O‐(2‐methoxyethyl)ribonucleosides, building blocks for second‐generation antisense oligonucleotides, starting from D‐glucose is presented. The key‐step is the transformation of 3‐O‐methoxyethylallofuranose to 2‐O‐(2‐methoxyethyl)ribose by NaIO4 oxidation. Together with the 4′‐phenylbenzoyl protecting group, which results in crystalline intermediates, this synthesis provides an easy and cheap access to 2′‐O‐(2‐methoxyethyl)‐substituted ribonucleosides.
Spectroscopic Study of Egyptian Blue Mixed with Other Pigments
Authors: Edreira M. Carmen , Feliu M. José , Fernández‐Lorenzo Concepción , Martín Joaquin
Published: February 2003

The Romans used a vast array of colors in their mural paints. The applied pigment mixtures containing Egyptian blue resulting in green, ochre, brown, gray, and white hues were studied. The chromatic characterization of wall paintings by electronic spectroscopy provided an easy and reliable procedure for the grouping of the samples to be studied (see Table). Subsequent use of other spectroscopic techniques such as Fourier‐transform (FT) IR and energy‐dispersive X‐ray spectroscopy (EDS), combined with X‐ray diffraction (XRD), led to convenient identification of the pictorial layer components that define and differentiate each chromatic group. Colors impossible to produce with only one pigment can be obtained by mixing Egyptian blue with other pigments. The dominant wavelength is displaced in such way that the artist obtains new tonalities.
Pteridines, Part CXIII
Authors: Yao Qizheng , Pfleiderer Wolfgang
Published: February 2003

The low solubility of pterins can drastically be improved by N2‐acylation or formation of the N2‐[(dimethylamino)methylene] derivatives. Both types of compounds can be alkylated under Mitsunobu conditions to form from N2‐acylpterins (see 2 and 3) and their derivatives (see 5, 6, 8, 9, 11, 13, 15, and 17) selectively the O4‐alkyl derivatives 22–31, whereas the electron‐donating [(dimethylamino)methyleneamino function in 46–51 gives, in a selective reaction, the N(3)‐substitution (→52–61). N2,N2‐Dimethylpterins and 18 and 19 and N2‐methylpterins 20 and 21 direct alkylation also to the O4‐position (→32–35, 38 and 39). Deacylation can be achieved under very mild conditions by solvolysis with MeOH (22→40, 26→41), and displacement of the O4‐[2‐(4‐nitrophenyl)ethyl] group proceeds with ammonia at room temperature to the corresponding pteridin‐2,4‐diamines 42–45. Cleavage of the N2‐[(dimethylamino)methylene] group works well with ammonia (→62–67). The advantage of applying the 2‐(4‐nitrophenyl)ethyl (npe) group as blocking group is seen in its selective removal by 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) under aprotic conditions without harming the other substituents.
Rapamycin inhibits proliferation of human neuroblastoma cells without suppression of MycN
Authors: Misawa Akiko , Hosoi Hajime , Tsuchiya Kunihiko , Sugimoto Tohru
Published: February 2003

MYCN and insulin‐like growth factor (IGF) system are important for the pathogenesis and development of neuroblastoma. We previously reported evidence of a direct linkage between MycN and the IGF system in KP‐N‐RT human neuroblastoma cells, where IGF‐I induced both MycN expression at the RNA level and G1‐S cell cycle progression through the IGF‐I receptor (IGF‐IR)/ MEK/ mitogen‐activated protein kinase (MAPK) pathway (A. Misawa et al., Cancer Res, 2000; 60:64–9). Our data also showed the possibility of a potent IGF‐IR downstream signal cascade that accelerates progression into the S‐phase, other than the MAPK pathway. In this study, we further investigated the role of this alternative pathway in the growth of neuroblastoma cells. A phosphoinositide 3‐kinase (PI3K) inhibitor wortmannin blocked IGF‐I‐mediated induction of MycN. Our data suggest that the inhibition of MycN by wortmannin was transmitted through the MAPK pathway. Progression of the cell cycle from G1 to S phase was inhibited up to 90% by wortmannin or rapamycin, an inhibitor of mTOR, which acts downstream of PI3K. Despite its effects on induction of MycN and on progression through S phase, wortmannin did not block proliferation of neuroblastoma cells. On the other hand, rapamycin inhibited both IGF‐I‐induced cell cycle progression and cell proliferation in complete medium, although it had no effect on IGF‐I‐mediated MycN induction. Our study indicates maintenance of cell proliferation requires mTOR function, which is independent of MycN induction in human neuroblastoma cells. © 2003 Wiley‐Liss, Inc.
Regulation of the H19 imprinting gene expression in human nasopharyngeal carcinoma by methylation
Authors: Ng Aylwin , Tang Jing P. , Goh Christopher H.K. , Hui Kam M.
Published: February 2003

In East Asia and Singapore, the human nasopharyngeal carcinoma (NPC) presented clinically is mainly of the undifferentiated type. In contrast, the well‐differentiated squamous NPC is more commonly detected in the West. To study the potential differences in carcinogenesis between undifferentiated and differentiated human NPC, we employed cDNA microarrays to isolate genes that might be specific for human undifferentiated NPC. One of the genes identified to be specifically upregulated in the undifferentiated human NPC cell line CNE‐2 is the human imprinting gene H19. Interestingly, H19 is not expressed in the well‐differentiated human HK1 NPC cells. Northern blot and in situ hybridization analyses also confirmed that the H19 gene is strongly expressed in the undifferentiated CNE‐2 human NPC cell line but not in the well‐differentiated HK1 human NPC cell line. In situ hybridization and reverse transcriptase‐polymerase chain reaction also demonstrated that H19 is specifically expressed in NPC biopsies and not in non‐NPC human tissue biopsies. Furthermore, we demonstrated that deregulation of H19 gene expression in the well‐differentiated human HK1 NPC cells could be induced by the hypomethylation of CpG sites of the H19 promoter region. Hypermethylation of gene promoter regions might therefore be an important epigenetic event that plays a role in the differentiation of human NPC cells and the transcriptional silencing of imprinted genes. © 2003 Wiley‐Liss, Inc.
Ovulation and risk of epithelial ovarian cancer
Authors: Purdie David M. , Bain Christopher J. , Siskind Victor , Webb Penelope M. , Green Adèle C.
Published: February 2003

Incessant ovulation is thought to be one of the primary causes of epithelial ovarian cancer. However, the effects of ovulation at different ages and of the various exposures or events that suppress ovulation have not been established. We used data from an Australian case‐control study of 791 ovarian cancer cases and 853 controls to examine the effect of ovulation on ovarian cancer risk. The total number of lifetime ovulations was calculated using information provided in a monthly contraceptive/reproductive calendar, as well as incorporating other information such as average menstrual cycle length. An increase of 1 year's worth of ovulation was associated with a 6% increase in risk of ovarian cancer (95% confidence interval [CI] = 4–8%). Ovulations in the 20–29‐year age group were associated with the greatest risk, with a 20% increase in risk associated with each year of ovulation during this age period (95% CI = 13–26%). When the effects of different exposures that suppress ovulation were compared, there was an indication that some factors may have a greater effect than others. These findings support the theory that incessant ovulation is a major contributor to the occurrence of ovarian cancer and suggest that ovulations during the 20s may be those most associated with disease risk. © 2003 Wiley‐Liss, Inc.
Identification of a naturally processed HLA‐A*0201 HPV18 E7 T cell epitope by tumor cell mediated in vitro vaccination
Authors: Kather Angela , Ferrara Alfonso , Nonn Marion , Schinz Manuela , Nieland John , Schneider Achim , Dürst Matthias , Kaufmann Andreas M.
Published: February 2003

Immunotherapy of HPV‐associated disease such as cervical cancer is moving from preclinical investigation to clinical trials. The viral oncoproteins E6 and E7 are ideal target antigens because their expression is mandatory in HPV‐transformed tumor cells. T cells are the most important effector cells for therapeutic vaccination strategies. Therefore, the identification and characterization of HPV E6 and E7 T cell epitopes is necessary. Methods to date rely on screening for immunogenicity of peptides predicted by algorithms. Presentation of the identified peptides on tumor cells, however, needs to be confirmed. In our study, we have improved the method to identify peptide epitopes of HPV18 E7 that are actually presented by tumor cells. We induced allogeneic T‐cell lines by stimulation with HPV18‐positive, CD80 and HLA‐A*0201 transfected cervical cancer cells. Sensitized T cells were probed against an array of a HPV18 E7 20mer peptide‐library. We found specific reactivity to one of the 20mer peptides. This sequence was then screened via algorithms for putative epitopes. One putative HLA‐A2 restricted epitope was confirmed to bind to HLA‐A2, to be immunogenic and to induce IFNγ‐release in ELISpot assays. Epitope‐specific T cells were cytolytic toward autologous peptide pulsed targets and HPV18 transformed tumor cells. The identification of epitope‐specific T cells in tumor infiltrating lymphocytes of a HPV18‐positive HLA‐matched cervical cancer patient suggests an in vivo relevance of the identified epitope. We suggest that our approach is advantageous over conventional methods, because it yields candidate peptides that are relevant CTL epitopes that are expressed, processed and presented by tumor cells. © 2003 Wiley‐Liss, Inc.
Suppression of invasion and peritoneal carcinomatosis of ovarian cancer cell line by overexpression of bikunin
Authors: Suzuki Mika , Kobayashi Hiroshi , Tanaka Yoshiko , Hirashima Yasuyuki , Kanayama Naohiro , Takei Yuji , Saga Yasushi , Suzuki Mitsuaki , Itoh Hiroshi , Terao Toshihiko
Published: February 2003

Bikunin (bik), a Kunitz‐type protease inhibitor, also known as urinary trypsin inhibitor, is proposed as a main participant in the inhibition of tumor cell invasion and metastasis, possibly through the direct inhibition of cell‐associated plasmin activity and suppression of urokinase‐type plasminogen activator (uPA) mRNA expression. In the present study, we transfected the human ovarian carcinoma cell line HRA, highly invasive cells, with an expression vector harboring a cDNA encoding for human bik. Our study was designed to investigate the effect of bik overexpression and changes in tumor cell phenotype and invasiveness in the stably transfected clones. Bik gene transfection of HRA gave the following results: 1) transfection of HRA with the bik cDNA resulted in 5 variants stably expressing functional bik; 2) bik+ clones exhibited a significantly reduced uPA mRNA expression as compared to the parental cells; 3) bikunin negatively regulates the ERK1/2 activity; 4) secretion‐blocking treatments of bik+ clones abrogated bik‐mediated suppression of ERK1/2 activation and uPA expression; 5) the regulation of invasion seen in the HRA cells is mainly mediated by the uPA‐plasmin‐MMP‐2 system; 6) transfection of HRA with the bik gene significantly reduced invasion, but not proliferation, adhesion, or migration relative to the parental cells; and 7) animals with bik+ clones induced reduced peritoneal dissemination and long term survival. We conclude that transfection of HRA cells with the bik cDNA constitutively suppresses ERK1/2 activation, which results in inhibition of uPA expression and subsequently reduces dissemination of bik+ clones. © 2003 Wiley‐Liss, Inc.
Human papillomavirus infection as a prognostic factor in carcinomas of the oral cavity and oropharynx
Authors: Ritchie Justine M. , Smith Elaine M. , Summersgill Kurt F. , Hoffman Henry T. , Wang Donghong , Klussmann Jens P. , Turek Lubomir P. , Haugen Thomas H.
Published: February 2003

Although studies have established human papillomaviruses (HPVs) as a risk factor for oral and oropharyngeal cancer, it is not clear whether viral infection affects survival in head and neck malignancies. This investigation examined the relationship between HPV and survival in carcinomas of the oral cavity and oropharynx. Formalin‐fixed, paraffin‐embedded tumor specimens from 139 newly diagnosed cases were tested for HPVs by PCR and DNA sequencing. Patient and tumor characteristics were obtained from questionnaires, pathology reports and cancer registries. Odds ratios (ORs) and relative risks (RRs) were based on logistic and Cox regression models, respectively. HPVs were detected in 21% of the tumors; 83% were HPV‐16. Greater risk of HPV infection was associated with males (OR = 2.9, 95% CI = 1.0–8.6), a history of oral‐genital sex (OR = 4.2, 95% CI = 1.5–11.7), and oropharyngeal tumors (OR = 10.4, 95% CI = 3.5–31.2). As tobacco usage increased, the odds of HPV detection decreased (OR = 0.97/pack‐year, 95% CI = 0.96–0.99). HPV infected patients had better overall survival (RR = 0.3, 95% CI = 0.1–0.8) than those with HPV‐negative tumors. There was an interaction between gender and HPV for overall (p= 0.05) and disease‐specific (p= 0.03) survival that suggested that HPV infected males had better prognosis than HPV‐negative males, but this was not the case among females. HPV status was identified as an independent prognostic factor in oral and oropharyngeal cancers. This result appeared to be gender‐specific, suggesting the need for further study of the interaction between HPV and gender on survival. © 2003 Wiley‐Liss, Inc.
A cyclooxygenase‐2 inhibitor, nimesulide, inhibits postinitiation phase of N‐nitrosobis(2‐oxopropyl)amine‐induced pancreatic carcinogenesis in hamsters
Authors: Furukawa Fumio , Nishikawa Akiyoshi , Lee In‐Seon , Kanki Keita , Umemura Takashi , Okazaki Kazushi , Kawamori Toshihito , Wakabayashi Keiji , Hirose Masao
Published: February 2003

The modification effects of nimesulide, a cyclooxygenase (COX)‐2 inhibitor, administration during the postinitiation phase of pancreatic carcinogenesis were investigated in hamsters treated with N‐nitrosobis(2‐oxopropyl)amine (BOP). Male Syrian hamsters were given 4 weekly s.c. injections of BOP at a dose of 10 mg/kg and thereafter administered 0, 100 or 400 ppm nimesulide in the diet for 36 weeks. Additional groups of hamsters were fed 400 ppm nimesulide without prior BOP initiation or nontreated. At week 40, all surviving animals were killed and development of neoplastic and preneoplastic lesions was assessed histopathologically. The incidence of pancreatic adenocarcinomas was significantly (p < 0.05) decreased in the BOP/400 ppm nimesulide group compared to the BOP alone group. The multiplicity of total lesions of pancreatic adenocarcinoma plus atypical hyperplasia was also significantly (p < 0.05) lowered. Immunohistochemically, COX‐2 was clearly expressed in pancreatic and lung tumor cells, whereas expression was not remarkably affected by the 400 ppm nimesulide treatment. Proliferating cell nuclear antigen labeling indices of pancreatic ducts were significantly (p < 0.01) reduced by nimesulide. The incidence and multiplicity of neoplastic lesions in other organs did not significantly differ among the BOP‐treated groups, though only the multiplicity of lung tumors showed a tendency to decrease. No neoplastic lesions were detected in animals receiving nimesulide alone. Our results clearly indicate that nimesulide protects against BOP‐induced pancreatic tumors in hamsters. © 2003 Wiley‐Liss, Inc.
Expression and role of MICA and MICB in human hepatocellular carcinomas and their regulation by retinoic acid
Authors: Jinushi Masahisa , Takehara Tetsuo , Tatsumi Tomohide , Kanto Tatsuya , Groh Veronika , Spies Thomas , Kimura Ritsuko , Miyagi Takuya , Mochizuki Kiyoshi , Sasaki Yutaka , Hayashi Norio
Published: February 2003

Natural killer (NK) cells are important effector cells for the first line of defense against tumor, but the mechanisms by which they recognize and kill human hepatocellular carcinoma (HCC) remains to be elucidated. Distant MHC class I homologs MICA and MICB are recently identified human ligands for NK cell activating receptor NKG2D. In our present study, MICA or MICB transcript was detected in 6 of 10 human hepatocellular carcinoma tissues, but not in the surrounding non‐cancerous tissues. Immunohistochemical analysis showed that MICA/B were expressed in the tumor cells of the cancerous tissues. Huh7 and HepG2 hepatoma cells, but not Hep3B cells, substantially expressed MICA/B on their cell surface. MICA/B expressed on hepatoma cells contributed to their NK sensitivity, because Huh7 and HepG2 were less susceptible to NK cytolysis when MAb against MICA/B was added during the cytolysis assay. Of interest is the finding that retinoic acid upregulated expression of MICA/B in Huh7 and HepG2 cells. Retinoic acid‐treated hepatoma cells induced IFNγ production from cocultured NK cells and rendered themselves more susceptible to NK cells. This was clearly dependent on upregulation of MICA/B, because both the enhanced IFNγ production and NK cytolysis were completely abolished by MAb‐mediated masking of MICA/B. These results suggest that MICA/B, expressed on a subset of human HCCs, may play an important role in their susceptibility to NK cells. Furthermore, retinoic acid can function as a modulator of MICA/B expression and thereby further activate NK cells. © 2003 Wiley‐Liss, Inc.
The cytoplasmic tail of invariant chain modulates antigen processing and presentation
Authors: Gregers Tone F. , Nordeng Tommy W. , Birkeland Hanne C. G. , Sandlie Inger , Bakke Oddmund
Published: February 2003

The MHC class II‐associated invariant chain (Ii) has several important functions in antigen presentation. In this study, we have examined the effect of Iip33 expression on endocytic transport and antigen presentation. We find that degradation of both endocytosed antigen and Ii itself is delayed in cells expressing high levels of Ii, whereas a mutant Ii with an altered charge distributionin the cytoplasmic tail was unable to exert this effect. Furthermore, the Ii mutant did not enhance the presentation of an Ii‐dependent MHC class II‐restricted epitope to the same extent as the wild type. In a parallel study, we investigated the effect of charge in the cytoplasmic tail of Ii. We find that due to exposed negative charges, it promotes endosome fusion events, and we suggest thatthis causes endosomal retention (Nordeng et al., Mol. Biol. Cell 2002). Together, the data reveal an additional property of the Iip33 cytoplasmic tail that contributes to the modulation of antigen processing and presentation.
T cell recognition and therapeutic effect of a phosphorylated synthetic peptide of the 70K snRNP protein administered in MRL/lpr mice
Authors: Monneaux Fanny , Lozano José Manuel , Patarroyo Manuel E. , Briand Jean‐Paul , Muller Sylviane
Published: February 2003

Modifications of self antigens that occur during apoptosis might be involved in the generation of neo‐antigens, which can break tolerance and induce autoimmunity. We have previously identifiedan epitope at residues 131–151 of the U1‐70K snRNP protein, recognized by IgG antibodies and CD4+ T cells from at least two strains of lupus mice. With the aim of investigating the possible role of phosphorylation on the antigenicity of peptide 131–151 and to gain a better understanding of how this peptide can drive autoimmune response, we synthesized two peptides phosphorylated on Ser137 and 140, respectively. We show here that peptide P140 phosphorylated on Ser140 is recognized by both CD4+ T cells and antibodies from MRL/lpr mice. Furthermore, intravenous administration to lupus‐prone MRL/lpr mice of P140 in saline (but not of the non‐phosphorylated peptide) decreased proteinuria and anti‐DNA antibody production, and significantly prolonged survival of treated mice. We further demonstrated that P140 is recognized by antibodies from lupus patients and binds to various HLA DR molecules, offering new hope for manipulating T cell response in humans.
ICOS+ Th cells produce distinct cytokines in different mucosal immune responses
Authors: Bonhagen Kerstin , Liesenfeld Oliver , Stadecker Miguel J. , Hutloff Andreas , Erb Klaus , Coyle Anthony J. , Lipp Martin , Kroczek Richard A. , Kamradt Thomas
Published: February 2003

T cell activation, differentiation and effector functions depend on signals delivered through the antigen‐specific TCR and non‐clonal costimulatory receptors on the T cell. Activated T cells express the inducible costimulator (ICOS). We examined the co‐expression of ICOS with Th cytokines in mucosal immune responses. ICOS+CD4+ Th cells expressed strikingly different cytokines depending on the type of infection encountered and the cells' anatomical localization. In the Th2‐dominated response to Schistosoma mansoni, ICOS expression of CD4+ cells isolated from the liver was strongly associated with the expression of IL‐5, IL‐10, IL‐13, and T1/ST2, but not with the chemokine receptor CXCR5, a pattern consistent with Th2 effector cells. In the secondary lymphatic organs of schistosome‐infected mice, ICOS expression was randomly correlated with Th2 effector‐cytokines, but positively correlated with CXCR5 expression; a pattern consistent with follicular Th cells. In Th cells isolated from gut or liver of mice infected with Toxoplasma gondii, ICOS expression was positively correlated with IFN‐γ production. Finally, in the severe combined immunodeficiency transfer colitis model, ICOS expression was strongly positively associated with IFN‐γ and IL‐2. Thus, ICOS appears to costimulate distinct effector functions in different immune responses, depending on factors such as the nature of the antigen encountered and localization and chronicity of the immune response.
Effect of anti‐macrophage inflammatory protein‐1α on leukocyte trafficking and disease progression in experimental autoimmune uveoretinitis
Authors: Crane Isabel J. , Xu Heping , Manivannan Ayyakkannu , McKillop‐Smith Susan , Lamont Graeme , Wallace Carol , Liversidge Janet , Sharp Peter F. , Forrester John V.
Published: February 2003

This study has enabled us to identify the influence of the chemokine, macrophage inflammatory protein‐1α (MIP‐1α), on leukocyte behavior at the blood‐retina barrier in vivo and its link with the inflammatory process and disease pathogenesis. MIP‐1α has not previously been thought to be effective under conditions of physiological shear flow. However, short‐term anti‐MIP‐1α treatment inhibited leukocyte slowing and accumulation and subsequent extravasation of leukocytes at the blood‐retina barrier in animals with experimental autoimmune uveoretinitis. This was effective predominantly in the post‐capillary venules which have been shown to be the main site of passage of leukocytes across the blood‐retina barrier. Long‐term anti‐MIP‐1α treatment also prevented decreased leukocyte velocity and reduced disease severity as measured clinically, histologically and in terms of blood‐retina barrier breakdown.
The ABC‐transporter signature motif is required for peptide translocation but not peptide binding by TAP
Authors: Hewitt Eric W. , Lehner Paul J.
Published: February 2003

The transporter associated with antigen processing (TAP) translocates peptides from their site of generation in the cytosol to the lumen of the endoplasmic reticulum for binding to MHC class Imolecules. TAP is a member of the ATP‐binding cassette (ABC) transporter family whose members utilize energy from ATP hydrolysis to translocate substrates across membranes. The highly conserved nucleotide‐binding domains of ABC transporters couple ATP hydrolysis to substrate translocation by the membrane domains. The conserved ‘signature motif’ can be identified in the nucleotide‐binding domains of all ABC transporters, and may play a role in ATP hydrolysis. Here we show that introduction of mutations into the signature motifs of either TAP1 or TAP2 inhibits the translocation of peptide without affecting binding of either peptide or ATP by TAP. We therefore conclude that the signature motifs in both TAP1 and TAP2 are required after peptide binding to facilitate peptide translocation by TAP.
Estradiol enhances primary antigen‐specific CD4 T cell responses and Th1 development in vivo. Essential role of estrogen receptor α expression in hematopoietic cells
Authors: Maret Arlette , Coudert Jérôme D. , Garidou Lucile , Foucras Gilles , Gourdy Pierre , Krust Andrée , Dupont Sonia , Chambon Pierre , Druet Philippe , Bayard Francis , Guéry Jean‐Charles
Published: February 2003

It is widely accepted that females have superior immune responses than males, but the ways by which sex hormones may enhance T cell responses are still poorly understood. In the present study,we analyzed the effect of estrogens on CD4 T cell activation and differentiation after immunization with exogenous antigens. We show that administration of low doses of 17ß‐estradiol (E2) to castrated female mice results in a striking increase of antigen‐specific CD4 T cell responses and in the selective development of IFN‐γ‐producing cells. Quantitative assessment of the frequency of T cells bearing a public TCR ß chain CDR3 motif demonstrated that the clonal size of primary antigen‐specific CD4 T cells was dramatically increased in immune lymph nodes from E2‐treated mice. By usingmice with disrupted estrogen receptor (ER) α or ß genes, we show that ERα, but not ERβ, was necessary for the enhanced E2‐driven Th1 cell responsiveness. Furthermore, ERα expressionin hematopoietic cells was essential, since E2 effects on Th1 responses were only observed in mice reconstituted with bone marrow cells from ERα+/+, but not ERα‐deficient mice. These results demonstrate that estrogen administration promotes strong antigen‐specific Th1 cell responses in a mechanism that requires functional expression of ERα in hematopoietic cells.
The C‐type lectin DC‐SIGN (CD209) is an antigen‐uptake receptor for Candida albicans on dendritic cells
Authors: Cambi Alessandra , Gijzen Karlijn , de Vries I. Jolanda M. , Torensma Ruurd , Joosten Ben , Adema Gosse J. , Netea Mihai G. , Kullberg Bart‐Jan , Romani Luigina , Figdor Carl G.
Published: February 2003

Dendritic cells (DC) that express the type II C‐type lectin DC‐SIGN (CD209) are located in the submucosa of tissues, where they mediate HIV‐1 entry. Interestingly, the pathogen Candida albicans,the major cause of hospital‐acquired fungal infections, penetrates at similar submucosal sites. Here we demonstrate that DC‐SIGN is able to bind C. albicans both in DC‐SIGN‐transfected cell lines and in human monocyte‐derived DC. The binding was shown to be time‐ as well as concentration‐dependent, and live as well as heat‐inactivated C. albicans were bound to the same extent. Moreover, in immature DC, DC‐SIGN was able to internalize C. albicans in specific DC‐SIGN‐enriched vesicles, distinct from those containing the mannose receptor, the other known C. albicans receptor expressed by DC. Together, these results demonstrate that DC‐SIGN is an exquisite pathogen‐uptake receptor that captures not only viruses but also fungi.
Lessons from success and/or failure of irrigation development
Authors: Hargreaves George H.
Published: February 2003

World population is increasing, particularly in the developing countries. Groundwater reserves are being depleted; lands are being degraded. The required increase in food production must come principally from new supplies of water for irrigated lands. If irrigated lands fail to produce the required food, increased destruction of resources and degradation of the environment from increasing slash and burn agriculture is anticipated. Various countries and international agencies have recognized the possibility of future food shortage. This paper presents case studies and includes technical and scientific considerations. In Greece, important considerations were land consolidation, and the incentives provided encouraged private initiative. The construction of large dams facilitated reforestation. In Haiti, flooding and erosion resulting from slash and burn agriculture, and land fragmentation were serious problems. Land redistribution and failure of maintenance resulted in the rapid deterioration and failure of the once prosperous colonial irrigation systems. Agrarian reform and/or the establishment of cooperatives with government landownership produced a rapid decline in irrigated production in various countries. In Honduras, little use has been made of 20 cooperatives financed by the government of Japan and the FAO. Various countries and international agencies have financed resource inventories and project studies and have provided funds for development. However, World Bank experience indicates that favorable laws and policies frequently have more influence on development than the availability of financial assistance. Strength in the rule of law, a free market economy, local and user participation in planning and management, and encouragement of private enterprise are frequently more important than the amount of money available from loans. Some successful training courses are described. A World Water and Climate Atlas is now available and can be used for many planning and risk evaluation purposes. Copyright © 2003 John Wiley & Sons, Ltd.
A simple start with far‐reaching consequences
Authors: de Bruin Dick , Schultz Bart
Published: February 2003

The history of water management in The Netherlands shows how the original natural landscape was transformed into a man‐made landscape and has led to a never‐ending struggle with the water. Water comes from all directions into the lowlands: over land via rivers (floods), from the sea side (surges), from above (excessive rainfall) and from the subsoil (seepage). Human intervention is continuously needed to be able to survive with effective solutions. History has shown that since men started intervening in nature, in particular in the alluvial water‐saturated soft soils where Dutch society has settled and developed, the need for these measures will never stop. Any one measure leads to counter and correcting measures later on. This is clearly visible today and it will definitively continue in the future. It sets the mind of Dutch society in its continuous struggle for life and can be a lesson learned for others, living and developing in areas with similar water‐related characteristics. Copyright © 2003 John Wiley & Sons, Ltd.
The impact of the Russian transition on psychosocial resources and psychological distress
Authors: Shteyn Marina , Schumm Jeremiah A. , Vodopianova Natalia , Hobfoll Stevan E. , Lilly Roy
Published: February 2003

Studies suggest that the difficult transition of the Russian economy has led to decreased physical health among Russians. However, the impact of economic turmoil on Russians' psychological health has not been examined. We used Hobfoll's (1988; 1998) Conservation of Resources (COR) theory to examine how economic losses deteriorate personal and social resources (e.g., mastery and social support), and how these deteriorated resources, in turn, impact psychological well being. Participants were Russian women working in the retail (n = 99) and medical (n = 99) fields, two poorly paid sectors. Structural equation modeling indicated that economic loss negatively impacted mastery, but not social support. Women with greater mastery and social support resources, in turn, reported less psychological distress. Economic loss had both direct and indirect effects, through mastery, on women's psychological distress. Results supported COR theory and point to the importance of building and sustaining personal and social resources in the face of major economic stress. © 2003 Wiley Periodicals, Inc.
Modification of uterine vasculature during pregnancy in macaques
Authors: Blankenship Thomas N. , Enders Allen C.
Published: February 2003

Embryonic development in macaques includes extensive modification of the uterine vasculature by fetal trophoblast cells. Soon after the onset of blastocyst attachment to the endometrium, syncytial trophoblast cells intrude between endometrial epithelial cells, resulting in focal epithelium loss. Trophoblast cells continue to move into the endometrial stroma and encounter superficial uterine capillaries. These capillaries are penetrated by trophoblast, which permits maternal blood to leave the maternal circulation and enter lacunae formed within the mass of trophoblast cells. Cytotrophoblast cells enter the uterine vessels and attach to the endothelium via cell adhesion molecules prior to migration into confluent spiral arterioles, against the flow of blood. As intra‐arterial cytotrophoblast cells migrate, they displace adjacent endothelium, produce matrix metalloproteinases, traverse the tunica intima, and reside in the tunica media as intramural trophoblast. Intramural trophoblast cells disrupt the tunica media and become surrounded by an extensive extracellular matrix. In areas proximal to the placenta, the entire circumferences of spiral arteries are modified in this way. In the same arteries, distal to the placenta and farther “upstream,” trophoblast‐mediated changes to the arterial wall are less extensive. Uterine veins are modified by trophoblast only in the area immediately next to the trophoblast shell, with no trophoblast migration. The functional consequence of this trophoblast activity may be to ensure an adequate flow of maternal blood to the placenta, thus enhancing the survival of the fetus. Microsc. Res. Tech. 60:390–401, 2003. © 2003 Wiley‐Liss, Inc.
Development of the utero‐placental circulation: The role of carbon monoxide and nitric oxide in trophoblast invasion and spiral artery transformation
Authors: Lyall Fiona
Published: February 2003

It is now well known that in order to establish human hemochorial placentation and to provide a progressive increase in blood supply to the growing fetus, the uterine spiral arteries must undergo considerable alterations. This physiological modification is thought to be brought about by the interaction of invasive cytotrophoblast with the spiral artery vessel wall. Despite intensive research our understanding of the mechanisms that control human trophoblast invasion in normal, let alone abnormal pregnancy, are sill poorly understood. This is partly due to difficulties in obtaining “true” placental bed biopsies and most investigators have relied on in vitro models of trophoblast invasion. This article describes the morphological changes that occur within the placental bed throughout human pregnancy along with a review of the various studies which have attempted to sample the placental bed. Thereafter, follows a review of the evidence that invasive trophoblast can release the vasoactive agents nitric oxide and/or carbon monoxide which, in turn, could contribute to early physiological changes in spiral arteries prior to destruction of the smooth muscle within the vessel wall. Current evidence supports the idea that trophoblast‐derived carbon monoxide may contribute to spiral artery modification. In contrast there is no evidence for a similar role by nitric oxide. Microsc. Res. Tech. 60:402–411, 2003. © 2003 Wiley‐Liss, Inc.
Endometrial arteriogenesis: Vascular smooth muscle cell proliferation and differentiation during the menstrual cycle and changes associated with endometrial bleeding disorders
Authors: Rogers Peter A.W. , Abberton Keren M.
Published: February 2003

The cyclical regrowth of the human endometrial vasculature every 28 days following menstruation provides an excellent opportunity for studying arteriogenesis in a human tissue. Despite this, very little has been published to date about temporal or spatial changes in endometrial arteriolar structure or function. Immunohistochemical studies using vascular smooth muscle cell (VSMC) differentiation markers have identified spatially organised differences in VSMC phenotype. However, these have not significantly increased our understanding of how or when arteriogenesis occurs. Endometrial VSMC proliferation continues at a steady rate throughout the cycle, increasing in the specialised spiral arterioles in the mid and late secretory phases. Although estrogen and progesterone play a dominant role in regulating endometrial growth and regression, their direct involvement in arteriogenesis is less clear. Estrogen and progesterone receptors have been reported in endometrial VSMC, although heterogeneity of expression occurs. The angiopoietin/Tie axis has been investigated in endometrium, although the results of 3 studies published to date are contradictory, making conclusions about a role in arteriogenesis problematic. Abnormalities of arteriogenesis may play a role in disorders such as menorrhagia and breakthrough bleeding in contraceptive and hormone replacement therapy users. There is evidence that VSMC proliferation is reduced in spiral arterioles of women with menorrhagia, along with reduced pulsatility index of the uterine artery as shown by Doppler ultrasound. In women taking progestin‐only contraception, endometrial perivascular alpha smooth muscle actin is reduced in those who suffer from breakthrough bleeding compared to those that don't. Considerable work is still required to elucidate when in the cycle, where in the tissue, and what mechanisms regulate endometrial arteriogenesis. Microsc. Res. Tech. 60:412–419, 2003. © 2003 Wiley‐Liss, Inc.