bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypermethylation of the human telomerase catalytic subunit (hTERT) gene correlates with telomerase activity
Authors: Guilleret Isabelle , Yan Pu , Grange Fabienne , Braunschweig Richard , Bosman Fred T. , Benhattar Jean
Published: October 2002

DNA methylation is an epigenetic process involved in embryonic development, differentiation and aging. It is 1 of the mechanisms resulting in gene silencing in carcinogenesis, especially in tumor suppressor genes (e.g., p16, Rb). Telomerase, the DNA polymerase adding TTAGGG repeats to the chromosome end, is involved in the regulation of the replicative life span by maintaining telomere length. This enzyme is activated in germ and stem cells, repressed in normal somatic cells and reactivated in a large majority of tumor cells. The promoter region of the hTERT gene, encoding for the catalytic subunit of human telomerase, has been located in a CpG island and may therefore be regulated at least in part by DNA methylation. We analyzed the methylation status of 27 CpG sites within the hTERT promoter core region by methylation‐sensitive single‐strand conformation analysis (MS‐SSCA) and direct sequencing using bisulfite‐modified DNA in 56 human tumor cell lines, as well as tumor and normal tissues from different organs. A positive correlation was observed among hypermethylation of the hTERT promoter, hTERT mRNA expression and telomerase activity (p < 0.00001). Furthermore, this correlation was confirmed in normal tissues where hypermethylation of the hTERT promoter was found exclusively in hTERT‐expressing telomerase‐positive samples and was absent in telomerase‐negative samples (p < 0.00002). Since tumor tissues contain also nonneoplastic stromal elements, we performed microdissection to allow confirmation that the hTERT promoter methylation truly occurred in tumor cells. Our results suggest that methylation may be involved in the regulation of hTERT gene expression. To our knowledge, this is the first gene in which methylation of its promoter sequence has been found to be positively correlated with gene expression. © 2002 Wiley‐Liss, Inc.
Persistent oxidative stress in colorectal carcinoma patients
Authors: Gackowski Daniel , Banaszkiewicz Zbigniew , Rozalski Rafał , Jawien Arkadiusz , Olinski Ryszard
Published: October 2002

We examine whether the level of 8‐oxo‐2′‐deoxyguanosine (8‐oxodGuo) in lymphocytes DNA is higher in colon cancer when compared to the control group. Factors that may influence oxidative stress such as antioxidant vitamins and uric acid were also determined. Blood samples were obtained from a control group of 55 healthy persons and 43 colon cancers. 8‐OxodGuo level and the vitamins concentration were measured by high‐performance liquid chromatography. The levels of 8‐oxodGuo were significantly higher whereas the concentrations of the vitamins and uric acid were significantly lower in colon cancer patients than in control group. Therefore, the decreased concentration of antioxidant vitamins together with lower amount of uric acid may be responsible for the formation of pro‐oxidative environment in blood of colorectal carcinoma patients. © 2002 Wiley‐Liss, Inc.
E‐cadherin gene variants in gastric cancer families whose probands are diagnosed with diffuse gastric cancer
Authors: Yabuta Tomonori , Shinmura Kazuya , Tani Masachika , Yamaguchi Satoru , Yoshimura Kimio , Katai Hitoshi , Nakajima Takashi , Mochiki Erito , Tsujinaka Toshimasa , Takami Motohisa , Hirose Kazuo , Yamaguchi Akio , Takenoshita Seiichi , Yokota Jun
Published: October 2002

To identify germline E‐cadherin mutations responsible for the predisposition to diffuse gastric cancer (DGC) among the Japanese, we screened 17 patients with familial aggregation of gastric cancer by sequencing analysis. All the patients were diagnosed with DGC and had at least 1 sibling with gastric cancer. Two novel E‐cadherin gene variants were detected. One was detected in 1 patient only and associated with an amino acid substitution (Val/Met) at codon 832 in the region essential for binding to β‐catenin. The M832 variant was detected not only in the proband but also in 2 other gastric cancer patients in the family. Immunohistochemical analysis of gastric cancer tissue from the proband revealed that E‐cadherin expression was markedly reduced and β‐catenin expression was also reduced in cancer cells. However, no significant difference in the activity of β‐catenin binding was detected between the M832 variant and V832 wild‐type E‐cadherin in immunofluorescence and immunoprecipitation/Western blot analyses. The other was detected in 5 patients and was located in the splice donor site (IVS1+6T/C); however, RT‐PCR analysis indicated that the IVS+6C variant did not cause an aberrant splicing. Thus, the M832 variant could be a germline mutation causative of familial aggregation of DGC, although further functional studies are needed to understand the pathogenic significance of this variant. © 2002 Wiley‐Liss, Inc.
In vivo evaluation of hydroxyapatite foams
Authors: Sepulveda P. , Bressiani A. H. , Bressiani J. C. , Meseguer L. , König B.
Published: October 2002

Hydroxyapatite (HA) is widely applied as bone graft material due to its osteoconductive potential and well‐established biocompatibility. In this work, macroporous hydroxyapatite structures made through foaming of aqueous suspensions and gelcasting were tested for in vivo osteointegration. These foams are composed of a three‐dimensional array of spherical pores with diameters of approximately 100–500 μm, interconnected by windows of smaller size in the range of 30–120 μm. The HA foams were implanted in the tibia of albino New Zealand rabbits and removed after a period of 8 weeks. Histological analysis revealed that the pores in the foams were partially or completely filled progressively with mature new bone tissue and osteoid after the implanted period. No immune or inflammatory reactions were detected. The high osteoconductive potential of the HA foams provides a potential structure for use as bone substitute in orthopedic, oral, and cranio‐maxillofacial reconstructive surgery, and as dento‐alveolar implants. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 587–592, 2002
Adhesion and growth of endothelial cell on amphiphilic PU/PS IPN surface: Effect of amphiphilic balance and immobilized collagen
Authors: Kim J. H. , Kim S. H. , Kim H. K. , Akaike T. , Kim S. C.
Published: October 2002

Since natural blood vessels are lined with an endothelial cell (EC) monolayer, it is proposed that synthetic biomaterial surfaces be covered or seeded with endothelial cells for ideal nonthrombogenicity under normal conditions. The effects of the surface energy of hydrophilic‐hydrophobic IPN on EC adhesion and growth were investigated. The human umbilical vein endothelial cells (HUVECs) were cultured on polyurethane (PU)/polystyrene (PS) IPN prepared by changing only the amphiphilic balance and controlling the microphase separated surface structure. The collagens were immobilized on the IPN surfaces for enhanced adhesion of HUVECs, and the morphology of the collagens immobilized highly depended on the surface energy of the IPNs. The stranded rope structure of the collagen molecules in the solution state was maintained only on the surface of the IPN with intermediate hydrophilicity. The adhesion and the proliferation of ECs on the nontreated IPN surfaces increased by increasing the hydrophobicity of the IPNs, and they were optimized on the collagen‐treated IPN surface having an intermediate hydrophilicity. Finally, platelet adhesion was significantly reduced on the EC‐hybridized surface of the IPNs. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 613–621, 2002
Preparation of calcium aluminate cement for hard tissue repair: Effects of lithium fluoride and maleic acid on setting behavior, compressive strength, and biocompatibility
Authors: Oh Seung‐Han , Choi Se‐Young , Lee Yong‐Keun , Kim Kyoung Nam
Published: October 2002

We investigated lithium fluoride (LiF) and maleic acid (MA) containing calcium aluminate cement (CAC) for hard tissue repair. The objective of this study is to estimate the addition effects of LiF and MA on setting behavior, compressive strength, and biocompatibility of CAC and to find the most compatible composition of LiF and MA for using CAC as a new bone cement. The CAC was composed mainly of CaO · Al2O3. Samples of LiF and MA containing CAC were formed along with recording of setting time and peak temperature and then set cement was analyzed by X‐ray diffraction (XRD). Agar diffusion test, tetrazolium bromide (MTT) assay, and hemolysis test were used to detect initial in vitro biocompatibility of LiF and MA containing CAC. It was revealed from the results that LiF shortened setting time and decreased compressive strength, whereas MA delayed setting time and increased compressive strength. However, LiF and MA showed no or little influence on maximum temperature of CAC. CAC containing 0.5 g of LiF and 8.75 g of MA showed the highest compressive strength (111.64 ± 7.74 MPa) across all the experimental compositions. The CACs containing 0.5 g of LiF/8.75 g of MA and 1.01 g LiF/8.75 g of MA had no cytotoxicity and hemolysis. In this study, CAC with 0.5 g of LiF and 8.75g of MA showed the most compatible properties for using bone cement, and thus it was assessed a candidate for a new bone cement along with CAC. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 593–599, 2002
Growth of connective tissue progenitor cells on microtextured polydimethylsiloxane surfaces
Authors: Mata Alvaro , Boehm Cynthia , Fleischman Aaron J. , Muschler George , Roy Shuvo
Published: October 2002

Growth of human connective tissue progenitor cells (CTPs) was characterized on smooth and microtextured polydimethylsiloxane (PDMS) surfaces. Human bone‐marrow‐derived cells were cultured for 9 days under conditions promoting osteoblastic differentiation on smooth PDMS surfaces and on PDMS post microtextures that were 6 μm high and 5, 10, 20, and 40 μm in diameter, respectively. Glass tissue‐culture dishes were used as controls. The number of viable cells was determined, and an alkaline phosphatase stain was used as a marker for osteoblastic phenotype. CTPs attached, proliferated, and differentiated on all surfaces. Cells on the smooth PDMS and control surfaces spread and proliferated as colonies in proximity to other cells and migrated in random directions, with cell process lengths of up to 80 μm. In contrast, cells on the PDMS post microtextures grew as sparsely distributed networks of cells, with processes, occasionally up to 300 μm, that appeared to interact with the posts. Cell counts revealed that there were fewer (50%) CTPs on the smooth PDMS surface than were on the glass control surfaces. However, there were consistently more (>144%) CTPs on the PDMS post textures than on the controls. In particular, the 10‐μm‐in‐diameter posts (268%) exhibited a significantly (p < 0.05) greater cell number than did the smooth PDMS. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 499–506, 2002
Oxidation‐induced dynamic changes in morphology reflected on freeze‐fractured surface of gamma‐irradiated ultra‐high molecular weight polyethylene components
Authors: Watanabe Eiichiro , Suzuki Masahiko , Nagata Kazuya , Kaneeda Toshiaki , Harada Yoshitada , Utsumi Masahiro , Mori Akiko , Moriya Hideshige
Published: October 2002

Oxidative degradation of ultra‐high molecular weight polyethylene (UHMWPE) attributed to sterilization by gamma‐radiation in the presence of air has been cited as one of the major causes of premature wear in total joint arthroplasty. For example, in retrieved UHMWPE tibial bearings, not only adhesive and abrasive wear, but also fatigue wear characterized by delamination and fracture is frequently observed. In this study, we examined the effects of gamma radiation on the microstructural morphology of UHMWPE tibial bearings, and propose a severe fatigue wear mechanism. Scanning electron microscopic observations were conducted on freeze‐fractured surface of retrieved UHMWPE components that had been sterilized with gamma radiation in air before implantation, unused components that had been stored on the shelf for several years (5–11) after sterilization, and disc specimens given an accelerated aging protocol after gamma radiation. Scanning electron microscopic observations showed that the freeze‐fractured surface of these components had a double layer, which was bordered below the surface. A closer observation of the subsurface layer below the border revealed an extremely rough and porous honeycomb‐like structure. Fourier transform infrared analysis demonstrated that the honeycomb‐like region in the subsurface had a high oxidation level. The internal morphology of oxidized UHMWPE was classified into four categories based on the level of the oxidation. According to these results, the morphological changes with oxidative degradation of gamma‐irradiated UHMWPEs in the presence of air could consistently be explained as the result of major chemical and physical changes such as increased crystallinity, elevated density, and reduced mechanical strength. We relate the morphological changes caused by oxidative degradation in the subsurface to the location of the origin of fatigue wear in total knee joints. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 540–549, 2002
Transfectant mosaic spheroids: a new model for evaluation of tumour cell killing in targeted radiotherapy and experimental gene therapy
Authors: Boyd M. , Mairs S. C. , Stevenson K. , Livingstone A. , Clark A. M. , Ross S. C. , Mairs R. J.
Published: October 2002

Background

We describe an in vitro tumour model for targeted radiotherapy and gene therapy that incorporates cell population heterogeneity.

Materials and methods

Transfectant mosaic spheroids (TMS) and transfected mosaic monolayers (TMM) are composed of two cell populations derived from a single cell line. The cells of one population were transfected with the noradrenaline transporter gene (NAT), allowing active uptake of a radiolabelled targeting agent meta‐[131I]iodobenzylguanidine ([131I]MIBG); the other population of cells was derived from the same parent line and transfected with a marker gene – green fluorescent protein (GFP). After treatment with [131I]MIBG, cell kill was determined in TMM by clonogenic assay and in TMS by clonogenic assay and spheroid growth delay.

Results

We have used the TMS model to assess the ‘radiological bystander effect’ (radiation cross‐fire) conferred by the β‐emitting radiopharmaceutical [131I] MIBG whose cellular uptake is facilitated by the transfected gene encoding NAT. We show that cell killing by [131I]MIBG in both TMS and TMM cultures increased in direct proportion to the fraction of NAT‐transfected cells and that the degree of cell killing against fraction transfected was greater in TMS, suggestive of a greater bystander effect in the three‐dimensional culture system.

Conclusions

TMS provide a useful model for assessment of the effectiveness of targeted radiotherapy in combination with gene therapy when less than 100% of the target cell population is expressing the NAT transgene. Further, this novel model offers the unique opportunity to investigate radiation‐induced bystander effects and their contribution to cell cytotoxicity in radiotherapy and other gene therapy applications. Copyright © 2002 John Wiley & Sons, Ltd.
Modification of pLL/DNA complexes with a multivalent hydrophilic polymer permits folate‐mediated targeting in vitro and prolonged plasma circulation in vivo
Authors: Ward Christopher M. , Pechar Michal , Oupicky David , Ulbrich Karel , Seymour Leonard W.
Published: October 2002

Background

Gene delivery vectors based on poly(L‐lysine) and DNA (pLL/DNA complexes) have limited use for targeted systemic application in vivo since they bind cells and proteins non‐specifically. In this study we have attempted to form folate‐targeted vectors with extended systemic circulation by surface modification of pLL/DNA complexes with hydrophilic polymers.

Methods

pLL/DNA complexes were stabilised by surface modification with a multivalent reactive polymer based on alternating segments of poly(ethylene glycol) and tripeptides bearing reactive ester groups. Folate moieties were incorporated into the vectors either by direct attachment of folate to the polymer or via intermediate poly(ethylene glycol) spacers of 800 and 3400 Da.

Results

Polymer‐coated complexes show similar morphology to uncoated complexes, their zeta potential is decreased towards zero, serum protein binding is inhibited and aqueous solubility is substantially increased. Intravenous (i.v.) administration to mice of coated complexes produced extended systemic circulation, with up to 2000‐fold more DNA measured in the bloodstream after 30 min compared with simple pLL/DNA complexes. In further contrast to simple pLL/DNA complexes, coated complexes do not bind blood cells in vivo. Folate receptor targeting is shown to mediate targeted association with HeLa cells in vitro, leading to increased transgene expression. We demonstrate for the first time that DNA uptake via the folate receptor is dependent on pEG spacer length, with the transgene expression relatively independent of the level of internalised DNA.

Conclusions

We show increased systemic circulation, decreased blood cell and protein binding, and folate‐targeted transgene expression using pLL/DNA complexes surface‐modified with a novel multireactive hydrophilic polymer. This work provides the basis for the development of plasma‐circulating targeted vectors for in vivo applications. Copyright © 2002 John Wiley & Sons, Ltd.
Two distinct types of hepatitis B virus core promoter variants in Yemeni blood donors
Authors: Sallam Talal A. , Tong C.Y. William
Published: October 2002

Genetic variations in the basic core promoter (BCP) region of hepatitis B virus (HBV) occur during the natural history of chronic HBV infection. This study investigates the presence of basic core promoter variations in 28 asymptomatic Yemeni blood donors, correlating variations with HBeAg phenotype and viral load. The core promoter/precore and surface gene region of HBV DNA were amplified using nested PCRs and the PCR products were sequenced either directly or after cloning. HBeAg and viral load were measured when HBV DNA was detectable. Sequencing of 18 surface PCR products indicated that all were of genotype D. Two distinct types of variants were identified in the basic core promoter: substitution only (N = 14) and major deletion (N = 9). The commonest substitutions were located at nucleotide positions 1753, 1762, and 1764; 10/14 (71.4%) were associated with the precore 1896A substitution resulting in the premature stop of the precore reading frame and 6/14 (42.9%) had viral loads above 400 copies/ml. Two forms of deletion variants were found: 8 bp deletion (1763–1770) (N = 2) and a novel 12 (1746–1757) + 8 bp (1763–1770) deletion (N = 7). The deletion sequences were never associated with the precore 1896A substitution and all had viral load below 400 copies/ml with negative HBeAg phenotype. The polymorphism 1773C was found in 9/14 (64.3%) substitution sequences whereas all deletion sequences had 1773T. Two donors had mixed sequences of basic core promoter substitution and major deletions (both 8 bp and 12 + 8 bp). While the deletion variants in these two donors were similar to others found in isolation, the substitutions were of a different pattern. Further studies are required to understand the selection process behind these variants. J. Med. Virol. 68:328–334, 2002. © 2002 Wiley‐Liss, Inc.
Lichenoid dermatitis‐treatment with pulsed dye laser: A case study
Authors: Greve Bärbel , Hartschuh Wolfgang , Raulin Christian
Published: October 2002

Background and Objectives

Both the diagnosis and the treatment of lichenoid dermatosis are often difficult and can be time‐consuming. There are now more and more publications about the use of laser systems—especially the flashlamp‐pumped pulsed dye laser—in the treatment of inflammatory dermatoses, although the laser's exact mechanism of action in these cases is not yet clear.

Study Design/Patients and Methods

We report on a female patient with lichenoid dermatitis that was presumably drug‐induced (roxatidine, H2 receptor antagonists). After a 10‐month treatment with local corticosteroids, without significant clearance the drug was discontinued and the pulsed dye laser was used (wavelength 585 nm, pulse duration 450 microseconds).

Results

Six laser treatments resulted in complete clearance of the lesions. No recurrence occurred during the follow‐up period of 54 months. Scars were not observed. A post‐operative biopsy showed no evidence of lichenoid dermatitis.

Conclusions

The pulsed dye laser seems to accelerate the clearance of presumably drug induced corticosteroid‐resistant lichenoid dermatoses. No permanent pigmental changes or scarring were observed. Lasers Surg. Med. 31:23–26, 2002. © 2002 Wiley‐Liss, Inc.
Stem‐like cells in hepatoblastoma
Authors: Ruck Peter , Xiao Jia‐Cheng
Published: October 2002

Background

The principles of tumor biology suggest that hepatoblastoma is derived from a pluripotent stem cell. Our studies were undertaken to investigate this tumor for the presence of cells with morphologic and immunophenotypic features of the oval cells of rodents that are thought to be closely related to hepatic stem cells.

Procedure

Hepatoblastomas of various subtypes were investigated by electron microscopy and immunoelectron microscopy with antibodies against cytokeratin 7, in the liver a marker of biliary differentiation, and albumin, a marker of hepatocytic differentiation. Immunohistochemical investigations were performed with the antibodies OV‐1 and OV‐6, which recognize antigens associated with oval cells.

Results

OV‐1 stained scattered cells in seven of 12 tumors investigated and OV‐6 in nine. Small epithelial cells (SEC) with the ultrastructural features of the oval cells were found by electron microscopy. They were characterized by small size (7–18 μm), often an oval shape, tonofilament bundles, and tight junctions or desmosome‐like junctions. SEC were found in small numbers in areas of fetal differentiation and in moderate numbers in areas of embryonal differentiation. In small cell hepatoblastoma, nearly all the tumor cells exhibited SEC‐like features. Immunoelectron microscopy revealed coexpression of cytokeratin 7 and albumin by SEC.

Conclusions

SEC with ultrastructural and immunophenotypic features exhibited by oval cells, i.e., hepatic stem‐like cells, are found in hepatoblastoma. Their numbers vary with the differing degrees of differentiation seen in the various subtypes. The findings further support the hypothesis that hepatoblastoma is derived from a pluripotent stem cell. Med Pediatr Oncol 2002;39:504–507. © 2002 Wiley‐Liss, Inc.
Transitional liver cell tumors (TLCT) in older children and adolescents: A novel group of aggressive hepatic tumors expressing beta‐catenin
Authors: Prokurat Andrzej , Kluge Przemysław , Kościesza Andrzej , Perek Danuta , Kappeler Andreas , Zimmermann Arthur
Published: October 2002

Background

We encountered on seven malignant hepatocellular tumors developing in older children and adolescents.

Results

These tumors exhibit an unusual phenotype with respect to clinical presentation, histopathology, immunohistochemistry, and treatment response. As a working hypothesis, we suggest that these apparently novel, unusual, and aggressive tumors occurring in older children and adolescents may form a transition in the putative developmental pathway of hepatocarcinogenesis.

Conclusion

We therefore propose the term, transitional liver cell tumors (TLCT), to denote these lesions. Med Pediatr Oncol 2002;39:510–518. © 2002 Wiley‐Liss, Inc.
Adult type vs. Childhood hepatocellular carcinoma—are they the same or different lesions? biology, natural history, prognosis, and treatment
Authors: Czauderna P.
Published: October 2002

Background

Differences in the biology, natural history, and treatment results of hepatocellular carcinoma (HCC) in children and adults were sought based on the literature and experience resulting from SIOPEL 1 trial.

Procedure

In the SIOPEL1 study, 40 children with HCC were registered from January 1990 to February 1994. Outcome was analyzed in 39. In most cases, disease was advanced at diagnosis: 31% had metastases and 39% had extrahepatic tumor extension and/or vascular invasion. More than 50% of patients had multifocal tumors; 39% of tumors were associated with hepatic cirrhosis. All, but two patients, received preoperative chemotherapy (PLADO—cisplatin and doxorubicin). Outcome, response to treatment, and prognostic factors were analyzed using the SAS statistical package.

Results

Overall survival (OS) at 5 years is 28% and EFS is 17% at median follow‐up of 75 months (49–90). Partial response to chemotherapy was observed in 18 of 37 cases evaluated (49%). Complete tumor resection was achieved in 14 of the 39 patients (36%). Twenty (51%) never became operable. Multifocality of the tumor, presence of metastases, and PRETEXT grouping adversely influenced OS. A large number of “de novo” HCC cases, fairly high response rate to preoperative chemotherapy (49%) and 54% survival after complete resection constitute a significant difference in comparison with adult HCC series.

Conclusions

Survival for pediatric HCC patients is below 30%. Radical tumor resection remains the only chance for survival. New multi‐center prospective studies in children with HCC are required to better results and to allow further study of differences between adult and pediatric HCC should they exist. Med Pediatr Oncol 2002;39:519–523. © 2002 Wiley‐Liss, Inc.
Genetic alterations in hepatoblastoma and hepatocellular carcinoma: Common and distinctive aspects
Authors: Buendia Marie Annick
Published: October 2002

Hepatoblastoma (HB) and hepatocellular carcinoma (HCC) are two different subtypes of primary tumors arising from liver parenchymal cells. These tumors differ by many histoclinical characteristics, and comparative analysis of genetic alterations in HB and HCC might provide some clues on the molecular oncogenic pathways leading to hepatocyte transformation. Recent outcomes have been provided by the assessmentof global genetic changes in tumor cells, using conventional cytogenetic approaches, PCR‐based microsatellite analysis and Comparative genomic Hybridization (CGH). Cytogenetic studies of HB, microsatellite analysis of HCC and recent CHG data have outlined common and distinctive characters between the two tumor types. HBs are characterized by a low number of chromosomal changes, consisting mainly of gains at chromosomes 1q, 2, 8q, 17q, and 20. By contrast, HCCs harbor multiple chromosomal abnormalities, predominantly losses, with increased chromosomal instability in tumors associated with hepatitis B virus infection. Common alterations in HB and HCC include gain of chromosomes 1q, 8q, and 17q, and loss of 4q. Another important common feature shared by the two tumor types is the frequent activation of Wnt/β‐catenin signaling by stabilizing mutations of β‐catenin. Immunohistochemical analysis of β‐catenin has demonstrated nuclear/cytoplasmic accumulation of the protein in most HBs and in more than one third of HCCs. Strikingly, β‐catenin mutations are associated with chromosomal stability in both tumor types. Together, these studies define different pathways in liver cell transformation, reflecting various developmental stages and multiple risk factors. A detailed understanding of the molecular hits underlying liver tumorigenesis, combined with clinicopathological parameters, will permit an accurate evaluation of major targets for prognostic and therapeutic intervention. Med Pediatr Oncol 2002;39:530–535. © 2002 Wiley‐Liss, Inc.
Morbidity after ambulatory urodynamics
Authors: Anders K. , Cardozo L. , Ashman O. , Khullar V.
Published: October 2002

Aims

To identify urinary symptoms and morbidity after ambulatory urodynamics.

Methods

One hundred consecutive women underwent ambulatory urodynamics for a variety of urinary complaints. Urinary symptom questionnaires were collected before investigation and again 48 hours later, reporting dysuria and haematuria. Women were screened for urinary tract infection before investigation and again 48 hours later.

Results

Of the 91 women who completed the study, 1 (1.1%) had a positive urinary culture after the investigation but was asymptomatic. Seventeen women reported mild to moderate de novo dysuria.

Conclusions

Urinary symptoms and morbidity after ambulatory monitoring is low. Neurourol. Urodynam. 21:461–463, 2002. © Wiley‐Liss, Inc.
Automatic construction of non‐obtuse boundary and/or interface Delaunay triangulations for control volume methods
Authors: Hitschfeld Nancy , Rivara María‐Cecilia
Published: October 2002

A Delaunay mesh without triangles having obtuse angles opposite to boundary and interface edges (obtuse boundary/interface triangles) is the basic requirement for problems solved using the control volume method. In this paper we discuss postprocess algorithms that allow the elimination of obtuse boundary/interface triangles of any constrained Delaunay triangulation with minimum angle ε. This is performed by the Delaunay insertion of a finite number of boundary and/or interface points. Techniques for the elimination of two kinds of obtuse boundary/interface triangles are discussed in detail: 1‐edge obtuse triangles, which have a boundary/interface (constrained) longest edge; and 2‐edge obtuse triangles, which have both their longest and second longest edge over the boundary/interface. More complex patterns of obtuse boundary/interface triangles, namely chains of 2‐edge constrained triangles forming a saw diagram and clusters of triangles that have constrained edges sharing a common vertex are managed by using a generalization of the above techniques. Examples of the use of these techniques for semiconductor device applications and a discussion on their generalization to 3‐dimensions (3D) are also included. Copyright © 2002 John Wiley & Sons, Ltd.
Stress‐related influences on blood pressure in African American women
Authors: Webb Mary S. , Beckstead Jason W.
Published: October 2002

The relationship of blood pressure status to three stress‐related variables, anger, coping resources, and strain, was evaluated in 90 African American women. The majority of the participants (57%) were normotensive, 32% of the participants reported current use of hypertensive medication, and an additional 16% had a mean blood pressure greater than 140/90 mmHg but were not on hypertensive therapy. From an analysis using ANCOVA, participants in the latter group were found to have significantly higher scores on rational‐cognitive coping resources, controlling for age, waist/hip ratio, and pack‐years. No significant differences among the blood pressure groups were found in anger or personal strain. Fostering rational‐cognitive coping skills, which represent the ability to problem‐solve effectively and to set priorities, may be beneficial for African American women and should be evaluated further in a larger sample. © 2002 Wiley Periodicals, Inc. Res Nurs Health 25:383–393, 2002
Rapid techniques for the extraction of vitamin E isomers from Amaranthus caudatus seeds: ultrasonic and supercritical fluid extraction
Authors: Bruni Renato , Guerrini Alessandra , Scalia Santo , Romagnoli Carlo , Sacchetti Gianni
Published: October 2002

Supercritical fluid extraction (SFE) of seeds of Amaranthus caudatus (Amaranthaceae) and the use of ultrasound as a co‐adjuvant in the extraction process were compared with methods traditionally used in the extraction of tocopherols and fatty acids. The use of readily available ultrasound equipment as an adjunct to the classical methods employed for the extraction of tocols provided qualitatively acceptable results more rapidly and more economically. SFE gave quantitatively better yields in shorter times, with solvent‐free extracts obtained under conditions that minimised the degradation of thermolabile components. No significant variations were observed in the profile of the fatty acids extracted from amaranth oil by SFE or other methods, thus confirming the qualitative comparability of the faster supercritical extraction with the more time‐consuming classical techniques even when processed with the aid of ultrasound. Copyright © 2002 John Wiley & Sons, Ltd.
Electronic structure calculations as a tool for investigating acyl migrations in ester aponins
Authors: Apers Sandra , Everaert Gert , Veken Benjamin J. van der , Vlietinck Arnold J. , Pieters Luc A. C.
Published: October 2002

The possibility of acyl migrations in ester saponins from Maesa lanceolata was investigated by molecular mechanics and electronic structure calculations carried out on the major constituent maesasaponin IV3 (3β‐O‐{[α‐L‐rhamnopyranosyl‐(1→2)‐β‐D‐galactopyranosyl‐(1→3)]‐[β‐D‐galactopyranosyl‐(1→2)]‐β‐D‐glucopyranuronyl}‐21β‐angeloyloxy‐22α‐propanoyloxy‐13β,28‐oxido‐olean‐16α, 28α‐diol). It was confirmed that acyl migrations could occur in rings D and E of maesasaponins. Copyright © 2002 John Wiley & Sons, Ltd.
Biflavonoids and a glucopyranoside derivative from Ouratea semiserrata
Authors: Velandia Javier Rincon , de Carvalho Mário Geraldo , Braz‐Filho Raimundo , Werle Alceni A.
Published: October 2002

Two new biflavonoids, 5‐hydroxy‐7‐methoxyflavone‐(4′ → O → 8″)‐4‴,5″,7″‐trihydroxyflavone and 5‐hydroxy‐7‐methoxyflavone‐(4′ → O → 8″)‐5″,7″‐dihydroxy‐4‴‐methoxyflavone, and the glucopyranoside derivative, 1‐O‐(4‐hydroxyphenyl)‐6‐O‐(4‐hydroxybenzoyl)‐β‐D‐glucopyranoside, as well as the known biflavones lanaraflavone, amentoflavone and podocarpusflavone, the triterpenes lupeol and friedelin, the lignans eudesmin and epieudesmin, the flavonol glycoside rutin, the steroids β‐sitosterol, stigmasterol, 3β‐O‐β‐D‐glucopyranosylsitosterol, 7‐oxostigmast‐5‐en‐3β‐ol and 7‐oxostigmasta‐5,22‐dien‐3β‐ol, the carbohydrates α‐ and β‐glucopyranose and 1‐O‐(4‐hydroxybenzoyl)‐β‐D‐glucopyranoside, and the norsesquiterpene 6,9‐dihydroxymegastigma‐4,7‐dien‐3‐one, have been isolated from leaves and branches of Ouratea semiserrata. The structures of these compounds were established from spectral data, including two‐dimensional NMR experiments and mass spectra. Copyright © 2002 John Wiley & Sons, Ltd.
CGH in the detection of confined placental mosaicism (CPM) in placentas of abnormal pregnancies
Authors: Amiel A. , Bouaron N. , Kidron D. , Sharony R. , Gaber E. , Fejgin M. D.
Published: October 2002

Comparative genomic hybridization (CGH) was applied to samples taken from various sites of placentas originating from complicated pregnancies: 24 with intrauterine growth restriction (IUGR), one with multiple fetal malformation, one with toxemia, one with hydrocephalus and two with undetectable maternal serum alpha‐fetoprotein (MSAFP). One of the most common aberrations in the IUGR cases was the addition of a whole or part of the X chromosome. Other aberrations such as additional Y chromosome or of 13(q22) or loss of chromosome 17 also appeared in different cases. In one IUGR case trisomy 8 (in one site) and 47,XXY (in all sites) were detected. In the two cases with undetectable MSAFP monosomy 16 was found. Some of the results were also confirmed by the FISH technique. In all the control cases (six normal and five with aneuploidy) CGH concurred with the known karyotype. Our results demonstrate the usefulness of the CGH technique in the genetic evaluation of fresh and paraffin embedded placentas in problematic pregnancies even when morphology is normal. However, it is very important to take multiple samples from different sites of the placenta. Copyright © 2002 John Wiley & Sons, Ltd.
Prenatal diagnosis and carrier detection for Athabascan severe combined immunodeficiency disease
Authors: Li Lanying , Zhou Yungui , Wang Junhua , Hu Diana , Cowan Morton J.
Published: October 2002

Objectives

Severe combined immunodeficiency disease occurs at a high incidence among Athabascan‐speaking Navajo and Apache children (SCIDA). We linked the SCIDA gene to chromosome 10p and recently identified a common nonsense mutation in Artemis/SCIDA. In this study we compared polymorphic markers linked to SCIDA and the point mutation which creates an NspI site on exon 8 for prenatal diagnosis and carrier detection.

Methods

We tested five amniocentesis samples, two cord blood and two blood samples from eight at‐risk families using polymorphic DNA markers tightly linked to SCIDA. We amplified the region of exon 8 of Artemis/SCIDA and evaluated the products for the NspI site in each sample plus samples from 30 unrelated healthy Navajos.

Results

We correctly predicted that three were affected and six were unaffected. Two of the unaffected appear to be carriers based on our haplotype analysis. Retrospective analysis for the gene mutation confirmed the DNA analysis. Finally, 10% of the normal Navajo controls were carriers.

Conclusions

We demonstrate the feasibility of prenatal diagnosis and carrier detection for SCIDA in the families at risk as well as the availability of a rapid screening test for the SCIDA founder mutation that can be used in all Navajo and Apache newborns and at‐risk fetuses. Copyright © 2002 John Wiley & Sons, Ltd.
Optimising the timing for nuchal translucency measurement
Authors: Mulvey Sheila , Baker Lesleigh , Edwards Andrew , Oldham Jacqui , Shekleton Paul , Wallace Euan M.
Published: October 2002

It appears from current evidence that the most effective screening strategy for Down syndrome will involve a combination of first trimester nuchal translucency and serum biochemistry, whether performed in the first or second trimester. The aim of this study was to determine the optimum gestation based upon menstrual dates at which to schedule nuchal translucency (NT) measurement for the evaluation of fetal Down syndrome risk. Five thousand eight hundred and thirty‐five pregnancies had an ultrasound scan scheduled between 11 and 14 completed weeks of gestation based upon either the last menstrual period (n = 3199) or a prior ultrasound scan (n = 2636). For last menstrual period‐based ultrasound scans, with advancing gestation the frequency of missed miscarriage significantly decreased (p = 0.009, chi squared test), as did the need to reschedule a further scan because the gestation of the scheduled scan was too early to measure NT (p < 0.0001, Chi‐squared test). In contrast, with advancing gestation the rate of unsuccessful NT measurement because the crown–rump length (CRL) was greater than 84 mm significantly increased (p < 0.0001, Chi‐squared test). Of the women who had had an earlier ultrasound, 42 (1.6%) had a missed miscarriage and 9 (0.3%) were over gestation at the time of the NT scan. These data suggest that when only the last menstrual period is known the optimum time to schedule a nuchal translucency measurement is at 12 to 13 weeks' gestation. Copyright © 2002 John Wiley & Sons, Ltd.
Prenatal and postnatal characterization of Y chromosome structural anomalies by molecular cytogenetic analysis
Authors: Hernando C. , Carrera M. , Ribas I. , Parear N. , Baraibar R. , Egocue J. , Fuster C.
Published: October 2002

We describe three cases in which we used fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR) and comparative genomic hybridization (CGH) to characterize Y chromosome structural anomalies, unidentifiable by conventional G‐banding. Case 1 was a 46,X,+mar karyotype; FISH analysis revealed an entire marker chromosome highlighted after hybridization with the Y chromosome painting probe. The PCR study showed the presence of Y chromosome markers AMG and SY620 and the absence of SY143, SY254 and SY147. CGH results confirmed the loss of Yq11.2‐qter. These results indicated the presence of a deletion: del(Y)(q11.2). Case 2 was a 45,X [14]/46,XY[86] karyotype with a very small Y chromosome. The PCR study showed the presence of Y chromosome markers SY620 and AMG, and the absence of SY143, SY254 and SY147. CGH results showed gain of Yq11.2‐pter and loss of Yq11.2‐q12. These results show the presence of a Yp isodicentric: idic(Y)(q11.2). Case 3 was a 45,X,inv(9)(p11q12)[30]/46,X,idic(Y)(p11.3?),inv(9)(p11q12)[70] karyotype. The FISH signal covered all the abnormal Y chromosome using a Y chromosome paint. The PCR study showed the presence of Y chromosome markers AMG, SY620, SY143, SY254 and SY147. CGH only showed gain of Yq11.2‐qter. These results support the presence of an unbalanced (Y;Y) translocation. Our results show that the combined use of molecular and classical cytogenetic methods in clinical diagnosis may allow a better delineation of the chromosome regions implicated in specific clinical disorders. Copyright © 2002 John Wiley & Sons, Ltd.
Studies of oxygen uptake on O2 scavengers ­prepared from different iron‐containing ­parent substances
Authors: Foltynowicz Zenon , Kozak Wojciech , Fiedorow Ryszard
Published: October 2002

Temperature‐programmed reduction (TPR) measurements were performed for iron oxalates, iron(III) hydroxide (both pure and with additives) and iron(II, III) oxide. On the ground of TPR curves, reduction temperatures of the iron‐containing parent substances were chosen followed by oxygen uptake determination. Comparison of oxygen uptakes points to the use of Fe(OH)3 and Fe3O4 as more advantageous than that of iron oxalates. Co‐precipitation from a mixed solution of iron and manganese salts results in a product which is more resistant to particle agglomeration at elevated temperatures than that obtained by­precipitation from solution of iron salt alone. Copyright © 2002 John­Wiley & Sons, Ltd.
Use of matrix clusters and trypsin autolysis fragments as mass calibrants in matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Harris William A. , Janecki Dariusz J. , Reilly James P.
Published: October 2002

Trypsin autolysis fragments and matrix clusters are often observed as intense peaks in mass spectra of protein digests. It is demonstrated that these can be exploited to improve the mass calibration of a matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) spectrometer. Interpretation of some of the autolysis masses is complicated by the existence of disulfide bonds. Surprisingly large matrix clusters are often visible for α‐cyano‐4‐hydroxy‐cinnamic acid. The fractional part of their masses differentiates them from protein digestion fragments. Copyright © 2002 John Wiley & Sons, Ltd.
Advantages and drawbacks of nanospray for studying noncovalent protein–DNA complexes by mass spectrometry
Authors: Gabelica Valérie , Vreuls Christelle , Filée Patrice , Duval Valérie , Joris Bernard , Pauw Edwin De
Published: October 2002

The noncovalent complexes between the BlaI protein dimer (wild‐type and GM2 mutant) and its double‐stranded DNA operator were studied by nanospray mass spectrometry and tandem mass spectrometry (MS/MS). Reproducibility problems in the nanospray single‐stage mass spectra are emphasized. The relative intensities depend greatly on the shape of the capillary tip and on the capillary‐cone distance. This results in difficulties in assessing the relative stabilities of the complexes simply from MS1 spectra of protein‐DNA mixtures. Competition experiments using MS/MS are a better approach to determine relative binding affinities. A competition between histidine‐tagged BlaIWT (BlaIWTHis) and the GM2 mutant revealed that the two proteins have similar affinities for the DNA operator, and that they co‐dimerize to form heterocomplexes. The low sample consumption of nanospray allows MS/MS spectra to be recorded at different collision energies for different charge states with 1 µL of sample. The MS/MS experiments on the dimers reveal that the GM2 dimer is more kinetically stable in the gas phase than the wild‐type dimer. The MS/MS experiments on the complexes shows that the two proteins require the same collision energy to dissociate from the complex. This indicates that the rate‐limiting step in the monomer loss from the protein‐DNA complex arises from the breaking of the protein‐DNA interface rather than the protein‐protein interface. The dissociation of the protein‐DNA complex proceeds by the loss of a highly charged monomer (carrying about two‐thirds of the total charge and one‐third of the total mass). MS/MS experiments on a heterocomplex also show that the two proteins BlaIWTHis and BlaIGM2 have slightly different charge distributions in the fragments. This emphasizes the need for better understanding the dissociation mechanisms of biomolecular complexes. Copyright © 2002 John Wiley & Sons, Ltd.
Differential macrohabitat use by birds on the unregulated Ovens River floodplain of southeastern Australia
Authors: Parkinson Amber , Mac Nally Ralph , Quinn G. P.
Published: October 2002

In many lowland floodplains around the world, upriver interferences to flows (weirs, dams, off‐takes) have led to much reduced frequency and duration of flooding. As a result, many floodplain wetlands are now inundated relatively rarely if at all. Given regulation of most lowland rivers in southeastern Australia, we assessed use of wetlands by birds in the essentially unregulated Ovens River in northeastern Victoria. Twelve sites (0.4–1.2 ha) were studied after flooding. Four sites were ‘permanent billabongs’, four were temporary wetlands and the other four were randomly selected woodland sites >60 m from the nearest water body (including the river) acting as ‘control’ or ‘reference’ sites. Aquatic birds were not recorded using woodland sites, but many species were differentially associated with either billabongs or temporary wetlands. A surprising number of non‐aquatic birds either exclusively or differentially were associated with wetland sites compared with woodland sites. We concluded that heterogeneous macrohabitat will increase local avian biodiversity on lowland floodplains. Moreover, densities and diversity of non‐aquatic, woodland species also increased with the presence of wetlands. Temporary wetlands were used differently from permanent billabongs by birds, especially in foraging methods. This suggests that the reinstatement of major flooding on heavily regulated floodplains would be ecologically advantageous for birds by providing foraging and breeding opportunities. Copyright © 2002 John Wiley & Sons, Ltd.
Measurement of segregation to grain boundaries in ferritic steel using Auger electron spectroscopy
Authors: Flewitt P. E. J. , Moskovic R. , Wild R. K.
Published: October 2002

This paper describes an investigation to measure phosphorus, tin and nickel concentrations at a number of equivalent grain boundary surfaces on corresponding fracture faces for a 3.5 wt.% nickel–ferritic steel specimen using Auger electron spectroscopy (AES). Multivariate statistical analyses of the data have been adopted to determine the significance of measurements undertaken on a single fracture surface compared with data combined from corresponding grains from integral grain boundaries within the polycrystal. The results are discussed with respect to the observed correlations between the key parameters and previously published data on similar materials. Copyright © 2002 John Wiley & Sons, Ltd.
Hierarchical statistical modelling of influenza epidemic dynamics in space and time
Authors: Mugglin Andrew S. , Cressie Noel , Gemmell Islay
Published: October 2002

An infectious disease typically spreads via contact between infected and susceptible individuals. Since the small‐scale movements and contacts between people are generally not recorded, available data regarding infectious disease are often aggregations in space and time, yielding small‐area counts of the number infected during successive, regular time intervals. In this paper, we develop a spatially descriptive, temporally dynamic hierarchical model to be fitted to such data. Disease counts are viewed as a realization from an underlying multivariate autoregressive process, where the relative risk of infection incorporates the space–time dynamic. We take a Bayesian approach, using Markov chain Monte Carlo to compute posterior estimates of all parameters of interest. We apply the methodology to an influenza epidemic in Scotland during the years 1989–1990. Copyright © 2002 John Wiley & Sons, Ltd.