bluuebunny/crossref_metadata_2025 huggingface dataset:
Working conditions and health among female and male employees at a call center in Sweden
Authors: Norman Kerstin , Nilsson Tohr , Hagberg Mats , Tornqvist Ewa Wigaeus , Toomingas Allan
Published: June 2004

Background

The call center industry is one of the most expansive labor market sectors in Sweden today. The purpose of this study was to investigate the working conditions and symptoms among employees at a call center in Sweden.

Methods

This study represents the cross‐sectional baseline survey, which was part of a prospective cohort study. Fifty‐seven call center workers were compared with a reference group of 1,459 professional computer users from other occupations. A questionnaire covered physical and psychosocial working conditions and symptoms during the last month. Structured observations in accordance with an ergonomic checklist were used to assess workstation design during the subject's ordinary work.

Results

The call center group had worked for a shorter time in their present tasks and spent longer continuous time in front of the computer than the reference group. There were deficiencies in workspace, keyboard‐ and input device placement. The subjects reported poor support from their immediate supervisor, low control and limited opportunities to influence their work. A higher proportion of the call center group reported musculoskeletal symptoms.

Conclusion

The call center operators were exposed to working conditions that in other studies have indicated an increased risk of developing musculoskeletal disorders. The study also shows that young computer operators in the call center group with a short working career had a higher prevalence of neck‐ and upper extremity symptoms than older computer workers in other labor market sectors. Am. J. Ind. Med. 46:55–62, 2004. © 2004 Wiley‐Liss, Inc.
Czech Dysplasia Metatarsal Type
Authors: Kozlowski K. , Marik I. , Marikova O. , Zemkova D. , Kuklik M.
Published: June 2004

We report three further patients of the recently described new bone dysplasia—dominantly inherited pseudorheumatoid arthritis. The patients of this report have a similar clinical history, the same distinctive phenotype and almost identical radiographic findings. The only major difference is absence of weather dependent articular pain which characterized the family of the previous study. This report expands the clinical data of this bone dysplasia. All patients are Caucasians and originate from different parts of the Czech Republic. It seems that this disorder is quite a common constitutional bone disorder in this country. We propose the name of Czech Dysplasia Metatarsal Type for this unique disease. © 2004 Wiley‐Liss, Inc.
Changes in social interactions during adolescence in male mandrills (Mandrillus sphinx)
Authors: Charpentier Marie , Peignot Patricia , Hossaert‐Mckey Martine , Wickings E. Jean
Published: June 2004

The adolescent period in male mandrills extends from the time the testicles descend (at the age of 3–4 years) to the time adult characteristics develop (at the age of 10 years), and is thus one of the longest adolescent periods in cercopithecines. In this short cross‐sectional study of 11 male mandrills (4.7–9.1 years old), we analyzed social behavioral patterns to investigate partner preference and changes in types of interactions throughout puberty. The mandrills were separated into two clusters on the basis of all of the social interactions scored, as well as the age and sex of the protagonist. During early to mid puberty, immature individuals interacted preferentially with other male adolescents and juveniles. Playing was an important activity, and some affiliative interactions with juveniles were observed. Older adolescents interacted more with adult males and females. These older adolescents were predominantly aggressive toward other adolescents, females, and juveniles, and showed little or no affiliative or playful behaviors. These results indicate a shift in social partners: older males interacted more frequently with adult males, and their behavior involved more aggression and less submission compared to younger adolescents, which showed predominantly submissive and playful behavior. These changes are consistent with preparation for dispersal and future intermale competition. Am. J. Primatol. 63:63–73, 2004. © 2004 Wiley‐Liss, Inc.
Genotyping aids field study of unhabituated wild chimpanzees
Authors: McGrew W.C. , Ensminger A.L. , Marchant L.F. , Pruetz J.D. , Vigilant L.
Published: June 2004

Prolonged habituation times for wild great apes delay the collection of behavioral and environmental data, sometimes for years. However, genotyping of noninvasively collected feces can provide useful socioecological information in the meantime. We tested this premise on an unhabituated wild population of western chimpanzees (Pan troglodytes verus) at Mont Assirik, Senegal. Genotyping yielded information on kinship, group size, party size and composition, sex ratio, and ranging. Am. J. Primatol. 63:87–93, 2004. © 2004 Wiley‐Liss, Inc.
Do males have a better chance of mating when the number of estrous females is equal to or greater than the males' ordinal rank? Testing the hypothesis in Japanese macaques
Authors: Takahashi Hiroyuki
Published: June 2004

This study was designed to test the hypothesis that male primates in multi‐male/multi‐female social groups with a clear male dominance hierarchy have a better chance of mating when the number of estrous females is equal to or greater than, as opposed to less than, the males' ordinal rank. I studied a Japanese macaque (Macaca fuscata fuscata) troop during mating seasons from 1992 to 1995. The mean daily operational sex ratio (OSR; the number of estrous females per troop male), which was calculated on observation days, was 0.21, 1.9, 0.48, and 3.1 in 1992–1995, respectively. Overall, focal animal sampling of males yielded 118 male‐day records. The male‐day records for each male were divided into the two estrous female number conditions: 1) the male‐day records when the number of estrous females was equal to or greater than the male's ordinal rank, and 2) the male‐day records when the number of estrous females was less than the male's ordinal rank. In the 1993 and 1995 mating seasons, when the number of estrous females was equal to or greater than the ordinal rank of each male, all of the males were observed mating. Conversely, when the number of estrous females was less than the ordinal rank of some male, they were not observed mating in the 1992 and 1994 mating seasons. The percentage for each male across each male's total mating opportunity was <20% when the number of estrous females was less than the male's ordinal rank. By contrast, the percentage for each male across each male's total mating opportunity exceeded 45% when the number of estrous females was equal to or greater than the male's ordinal rank, except for one male. Of all the male‐day records for males observed mating with ejaculation, 41 were obtained when the number of estrous females was equal to or greater than the male's rank; conversely, only three records were obtained when the number of estrous females was less than the male's ordinal rank. Therefore, it appears that males have a better chance of mating when the number of estrous females is equal to or greater than the males' ordinal rank, as opposed to when the number is less than their ordinal rank. Am. J. Primatol. 63:95–102, 2004. © 2004 Wiley‐Liss, Inc.
Clinical and cytogenetic manifestations of subtelomeric aberrations: Report of six cases
Authors: Font‐Montgomery Esperanza , Weaver David D. , Walsh Laurence , Christensen Celanie , Thurston Virginia C.
Published: June 2004

BACKGROUND

Fluorescent subtelomeric probes for the 41 different subtelomeric regions (the p arms of the acrocentric chromosomes were excluded) have been developed over the last 10 years. These probes can detect deletions, duplications, and translocations in the gene‐rich subtelomeric regions of human chromosomes, regions where crossing over frequently occurs and where a high number of abnormalities have been found. Recently, commercially produced probes have become available, which has led to the detection of subtelomeric abnormalities in 7.4% of patients with moderate to severe mental retardation (Knight et al., 1999).

CASES

We evaluated 43 dysmorphic children with developmental delay and/or mental retardation of unknown etiology and/or autism who were previously assessed for chromosome abnormalities, metabolic disorders, or recognizable dysmorphic syndromes, all of which were ruled out. Of the 43 children tested, 6 (14%) were found to have subtelomeric aberrations.

CONCLUSIONS

We recommend that patients with dysmorphic features and mental retardation of unknown etiology who also have a normal standard chromosome analysis should have subtelomeric FISH testing performed earlier in their clinical workup. Birth Defects Research (Part A), 2004. © 2004 Wiley‐Liss, Inc.
Zeta potential as a measure of polyelectrolyte flocculation and the effect of polymer dosing conditions on cell removal from fermentation broth
Authors: Pearson Carrie R. , Heng Meng , Gebert Mark , Glatz Charles E.
Published: June 2004

Characterization of flocculation for cell removal from fermentation broth via polyelectrolyte addition is commonly based on qualitative methods such as physical appearance of the floc. The use of zeta potential as a quantitative measure of floc character was evaluated as an indicator of optimal polymer addition. Zeta potential was found to increase with increasing cationic polyelectrolyte dosage, but never reached zero regardless of the total amount of polymer added, indicating flocculation occurs at least partially through a bridging type mechanism. Experiments were conducted using various polymer concentrations (25–75 g/L) and dosing methods (batch, incremental and continuous addition) that resulted in variable overall polymer requirements to achieve optimum flocculation. Zeta potential was found to be constant at optimal floc character regardless of the total amount of polymer added, polymer concentration, or method of polymer addition. Experiments with two additional types of fermentation broth also showed characteristic zeta potentials at optimal flocculation. Polymer requirements to achieve a particular floc character can vary greatly, depending on polymer dosing conditions and fermentation batch. The effect of polymer dosing conditions on the polymer requirement to obtain optimal floc character was evaluated. Polymer dosing method and calcium concentration were both found to have a significant effect (P < 0.0001) with continuous polymer addition and high calcium concentration requiring less polymer than did batch polymer addition and low calcium concentration, respectively. Polymer dosing concentration did not significantly affect polymer requirement for optimal flocculation. © 2004 Wiley Periodicals, Inc.
Establishing the multidisciplinary care of patients with cancer in the state of Delaware
Authors: Petrelli Nicholas J. , Grusenmeyer Patrick A.
Published: June 2004

Delaware has the fifth highest cancer death rate in the U.S. As part of a comprehensive program to decrease the cancer mortality and incidence in the state, an infrastructure to establish the multidisciplinary care of patients with cancer was established. In May 2002, Christiana Care Health Services opened the Helen F. Graham Cancer Center to meet the specific need for coordinated and centralized comprehensive cancer care. This effort took the cooperation of many individuals in a community‐based teaching hospital, the largest of six acute care hospitals in the state. These efforts have led to a 13% accrual rate to the Community Clinical Oncology Program funded by the National Cancer Institute. The effort also led to the establishment of multidisciplinary disease site centers with representation from the three major physician disciplines of surgery, medical oncology, and radiation oncology. In addition, translational research projects, a tissue procurement center, and genetic counseling and testing with the establishment of a high‐risk family cancer registry and collaborative efforts with hospitals across the state were established. The current article reviewed the continued success of this program in the state of Delaware in the effort to reduce the cancer incidence and mortality. Cancer 2004;. © 2004 American Cancer Society.
Adult Wilms' tumor: A monoinstitutional experience and a review of the literature
Authors: Terenziani Monica , Spreafico Filippo , Collini Paola , Piva Luigi , Perotti Daniela , Podda Marta , Gandola Lorenza , Massimino Maura , Cereda Stefano , Cefalo Graziella , Luksch Roberto , Casanova Michela , Ferrari Andrea , Polastri Daniela , Valagussa Pinuccia , Fossati‐Bellani Franca
Published: June 2004

BACKGROUND

The authors reviewed their institutional experience regarding adult patients with Wilms' tumor (WT) to assess their clinical characteristics and compliance with respect to children's treatment guidelines.

METHODS

A total of 17 adult patients (median age at the time of diagnosis of 17.5 years; range, 16–29 years) were referred to the study institute between 1983 and 2001 and were followed for a median of 131 months. The treatment modality was planned according to the two consecutive Italian protocols for WT that were active during the referral years. The patients were staged according to the National Wilms Tumor Study‐4 (NWTS) staging system as follows: eight patients had Stage II disease, four patients had Stage III disease, and five patients had Stage IV disease.

RESULTS

All the patients but one underwent nephrectomy, with three incomplete surgeries performed. Two patients with Stage II disease were treated elsewhere with nephrectomy only and they were admitted to the study institution at the time of disease recurrence. Anaplasia was found to be present in only one patient with Stage IV disease. The authors noted 9 cases of disease recurrence or progression occurring during treatment and 6 of these 9 patients died of their disease, with an overall survival rate of 62.4% at 5 years.

CONCLUSIONS

Compared with children, adults with WT are reported to have a worse prognosis. In the current study, the authors found that poor compliance with specific therapeutic guidelines may contribute to this poorer outcome. Because of the rarity of this disease, adults with WT are at a risk of either undertreatment or incorrect treatment. Cancer 2004. © 2004 American Cancer Society.
Prostate carcinoma among men with human immunodeficiency virus infection
Authors: Crum Nancy F. , Spencer Craig R. , Amling Christopher L.
Published: June 2004

BACKGROUND

Several malignancies are known to occur more frequently in individuals with human immunodeficiency virus (HIV) infection. To determine the incidence of prostate carcinoma in men with HIV infection, the authors initiated a prostate carcinoma screening program in a large HIV clinic.

METHODS

Beginning in February 2002, monitoring of prostate‐specific antigen (PSA) levels and digital rectal examination (DRE) were included in the routine annual health maintenance provided to men with HIV infection age ≥ 35 years who were followed in the infectious disease clinic at the Naval Medical Center San Diego. All men with prostate carcinoma in this population over the last 2 years were reviewed. Demographic data (age, ethnicity), duration of HIV infection, laboratory values (CD4 counts and HIV viral load), and medication use were determined by medical record review. Men with elevated PSA levels (levels above age‐adjusted PSA values or PSA velocity ≥ 0.75 ng/mL per year) or abnormal DRE results were referred for urologic evaluation. Comparisons between groups were performed using a logistic regression model and the Fisher exact test. Multivariate analysis was performed by logistic regression to determine relations between prostate carcinoma and patient characteristics.

RESULTS

Two hundred sixty‐nine men age ≥ 35 years (mean age, 43.4 years; range, 35–72years) underwent prostate carcinoma screening by DRE, and 216 men also received PSA testing. Overall, 56.3% of the patients were white, 28.7% were African American, and 15% were of other racial ethnicity. Of the 216 men, 7 (3.2%) had elevated PSA values, and none had abnormal DRE results. Three patients were diagnosed with prostatitis (PSA range, 3.3–25.7 ng/mL), and 1 patient had high‐grade prostatic intraepithelial neoplasia, which was determined after a biopsy was performed. Repeat PSA evaluations were within normal limits for the remaining three patients. Review of the cohort during the 2‐year period before the current study was initiated revealed 5 additional cases of prostate neoplasia. Prostate carcinoma was common (4 of 11 men, 36.4%) in men age > 60 years and occurred with relatively preserved CD4 counts (mean, 509 cells/mm3). In multivariate analysis, African‐American race (P = 0.020) and duration of HIV infection (P = 0.047) were found to be associated with the development of prostate carcinoma.

CONCLUSIONS

Prostate carcinoma screening identified abnormal PSA values in 3.2% of the HIV‐positive cohort, many associated with prostatitis. Prostate carcinoma was common in older men and was associated with duration of HIV infection. As the life expectancy of men with HIV infection increases, prostate carcinoma screening will become increasingly important in this population. Cancer 2004. Published 2004 by the American Cancer Society.
Mathematical and numerical connections between polynomial extrapolation and Padé approximants: applications in structural mechanics
Authors: Damil N. , Cadou J. M. , Potier‐Ferry M.
Published: June 2004

This paper deals with the convergence acceleration of a sequence of vectors. This acceleration is achieved by using Minimal Polynomial Extrapolation Method (J Comput Appl Math 2000; 122:149–165) or by the vectorial Padé approximants, that have been considered in the framework of high‐order iterative algorithms (Commun Numer Methods Eng 1999; 15:701–708; Comput Methods Appl Mech Eng 2000; 190:1845–1858). It is established that, in some cases, these two procedures are mathematically equivalent. In the practice, such techniques are affected by numerical instabilities. So the numerical robustness of the two methods is discussed, on the basis of a test emanating from non‐linear elastic thin shell analysis. Copyright © 2004 John Wiley & Sons, Ltd.
Locally refined tetrahedral mesh generation based on advancing front technique with optimization and smoothing scheme
Authors: Choi Woo‐Young , Son Il‐Heon , Im Yong‐Taek
Published: June 2004

In this paper, a locally refined tetrahedral mesh generation algorithm based on advancing front technique using optimization scheme with a non‐uniform trial height has been developed for three dimensional forming simulations to improve the quality of the local mesh system and computational efficiency. To generate locally refined surface elements, the refinement region was identified by checking the local effective strain rate and minimum interior angle of a surface element, respectively. In addition, a limiting value for the edge length of the tetrahedron was introduced to avoid generation of extremely small triangular surface elements. The developed scheme was applied for numerical simulations of indentation and spur gear and connecting rod forging. The computational results indicate that the currently developed algorithm was successful in generating better mesh system to finish numerical simulations with relatively shorter computation time compared to the previous scheme with a uniform trial height available in the literature. Copyright © 2004 John Wiley & Sons, Ltd.
Linda implementations in Java for concurrent systems
Authors: Wells G. C. , Chalmers A. G. , Clayton P. G.
Published: June 2004

This paper surveys a number of the implementations of Linda that are available in Java. It provides some discussion of their strengths and weaknesses, and presents the results from benchmarking experiments using a network of commodity workstations. Some extensions to the original Linda programming model are also presented and discussed, together with examples of their application to parallel processing problems. Copyright © 2004 John Wiley & Sons, Ltd.
The performance and scalability of SHMEM and MPI‐2 one‐sided routines on a SGI Origin 2000 and a Cray T3E‐600
Authors: Luecke Glenn R. , Spanoyannis Silvia , Kraeva Marina
Published: June 2004

This paper compares the performance and scalability of SHMEM and MPI‐2 one‐sided routines on different communication patterns for a SGI Origin 2000 and a Cray T3E‐600. The communication tests were chosen to represent commonly used communication patterns with low contention (accessing distant messages, a circular right shift, a binary tree broadcast) to communication patterns with high contention (a ‘naive’ broadcast and an all‐to‐all). For all the tests and for small message sizes, the SHMEM implementation significantly outperformed the MPI‐2 implementation for both the SGI Origin 2000 and Cray T3E‐600. Copyright © 2004 John Wiley & Sons, Ltd.
A new multi‐parameter flow cytometric assay for monitoring lymphoma growth and spread in a pre‐clinical murine model for human lymphoma
Authors: Neeson P. , Paterson Y.
Published: June 2004

Background

Mouse survival is commonly used as an indirect measure of lymphoma tumor response to anti‐idiotype vaccine; however, this gives no information regarding residual lymphoma cells at primary or metastatic sites. We aimed to develop a method with which to monitor lymphoma tumor kinetics in the mouse as an independent measure of vaccine efficacy.

Methods

We developed a multi‐parameter flow cytometric (MPFC) assay for 38C13 mouse lymphoma cells using sequential gating to detect aberrant antigen expression and binding by an anti‐idiotype antibody (S1C5). Subsequently, we tested the utility of the MPFC assay in a 38C13 tumor modeling study in the C3H/HeN mouse.

Results

The MPFC assay was demonstrated in vitro to have both high specificity and sensitivity for 38C13 lymphoma cells. In tumor kinetic studies in the C3H/HeN mouse, as the tumor enlarged, the MPFC assay showed increasing prevalence of 38C13 cells at the inoculation site in addition to metastases to lymphoid organs and bone marrow. The latter findings were confirmed by both histology and immunohistochemistry.

Conclusions

The MPFC assay is an independent parameter for monitoring 38C13 lymphoma kinetics and could be used to monitor tumor response to individual vaccines or other lymphoma therapy prior to clinical trials. © 2004 Wiley‐Liss, Inc.
Enrichment of presynaptic and postsynaptic markers by size‐based gating analysis of synaptosome preparations from rat and human cortex
Authors: Gylys Karen H. , Fein Jeffrey A. , Yang Fusheng , Cole Gregory M.
Published: June 2004

Background

Synapse regions in the brain are difficult to isolate and study; resealed nerve terminals (synaptosomes) are a widely used in vitro system for the study of neurotransmission, but nonsynaptosomal elements in the homogenate complicate data interpretation. With the goal of quantitative analysis of pathways leading to synapse loss in neurodegenerative disease, we have developed a method that allows focus on the intact synaptosomes within a crude synaptosomal preparation by gating the largest particles based on forward angle light scatter (FSC).

Methods

Crude synaptosomal fractions (P‐2) were prepared and labeled with a viability dye (calcein AM), a presynaptic marker (SNAP‐25), and a postsynaptic marker (PSD‐95). Forward scatter gates based on size standards were drawn to identify the large population (1.4–4.5 μm), and the enrichment of each marker was quantified in preparations from fresh rat homogenates and from cryopreserved human cortex.

Results

Gating on forward scatter resulted in an increase that was highly significant (P < 0.001) for all three markers examined. The calcein‐AM–positive fraction in the large synaptosomes was 98% ± 0.8, and 75% ± 9.8 for rat and human, respectively. Of large particles, 90% ± 2.7 in rat and 82% ± 2.6 in human were positive for SNAP‐25, indicating a relatively pure population of intact synaptosomes. A total of 76% ± 2.9 of the large particles were positive for PSD‐95 in rat. This compared to 36% ± 3.0 in human tissue, and indicates that both presynaptic and postsynaptic elements may be analyzed with this methodology.

Conclusions

Most nonsynaptosomal elements can be excluded and the intact subpopulation of interest within the P‐2 can be identified based on size. Size‐based gating analysis provides a simple and cost‐effective method to monitor fluorescence changes in synapse regions. © 2004 Wiley‐Liss, Inc.
Variances of the predicted state in the steady state for a three‐dimensional radar tracking using a linear filter
Authors: Kosuge Yoshio , Ito Masayoshi
Published: June 2004

We explain a tracking method that uses a linear filter to estimate the true values of the position and the velocity with the target position as the radar observation. One representative example is a Kalman filter for three‐dimensional space. The α‐β filter with its easily analyzed performance is widely used in one‐dimensional space. In a tracking method, the tracking precision must be evaluated when sufficient time has elapsed since the initial calculation, that is, in the steady state. The equation for calculating the variance of the errors in the predicted position in the steady state has been reported for radar observations of a constant‐velocity linear motion target by an α‐β filter. In addition, a Kalman filter can obtain the variance of the errors in the predicted position in the steady state by the Riccatti equation. In this case, however, a premise is the presence of drive noise that indicates the ambiguity of the motion model. There is no equation for calculating the variance of the errors in the predicted position in the steady state for the radar observations of a constant‐velocity linear motion target. In this paper, we present an equation for calculating the covariance matrix of the prediction errors in the steady state of the position and velocity for the radar observations of the constant‐velocity linear motion target in a 3D spatial linear filter. The results calculated in this paper present an extension of a conventional α‐β filter. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(12): 68–77, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10186
Synthesis of curved fan‐beams by generalized theory of doubly curved reflectors
Authors: Nomoto Shinichi
Published: June 2004

Although a reflector antenna with a single reflecting surface called a doubly curved reflector, based on a reflector shaping technology that uses geometrical optics approximation, was effective in synthesizing a fan‐beam, there was ambiguity in the reflector design technique. This paper shows that an exact and unique solution in the sense of geometrical optics is obtainable as a solution of an ordinary differential equation. It then generalizes the doubly curved reflector design method, extending it to the synthesis of a curved fan‐beam whose beam footprint has curvature. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(12): 39–48, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10219
Level of MYC overexpression in pediatric Burkitt's lymphoma is strongly dependent on genomic breakpoint location within the MYC locus
Authors: Wilda Monika , Busch Kerstin , Klose Irmgard , Keller Thomas , Woessmann Wilhelm , Kreuder Joachim , Harbott Jochen , Borkhardt Arndt
Published: June 2004

Increased transcriptional activity of the MYC gene is a characteristic feature of Burkitt's lymphoma. Aberrant MYC expression is caused by (1) chromosomal translocation to one of the loci carrying an immunoglobulin gene, (2) mutation within the translocated allele, (3) loss of the block to transcription elongation, or (4) promoter shift. To investigate the influence of breakpoint locations within the MYC gene on MYC transcript levels, we determined both the precise genomic MYC/IGH breakpoints and the amount of MYC mRNA in 25 samples of pediatric Burkitt's lymphoma with translocation t(8;14)(q24;q32). Patients with breakpoints that were 5′ from MYC exon 1 had significantly lower expression of MYC than did patients who had a breakpoint within exon 1 or intron 1 (P < 0.05 and 0.005, respectively). The highest mRNA level of MYC (1,006 copies per 100 copies ABL1) was detected in patients with loss of the first exon and transcription initiation from a cryptic P3 promoter within the first intron of the MYC gene. In contrast, there was no obvious correlation between breakpoint locations within the IgH locus and the amount of MYC mRNA. © 2004 Wiley‐Liss, Inc.
The influence of the pattern of mandibular invasion on recurrence and survival in oral squamous cell carcinoma
Authors: Shaw Richard J. , Brown James S. , Woolgar Julia A. , Lowe Derek , Rogers Simon N. , Vaughan E. David
Published: June 2004

Background.

Controversy exists over the predictive value of the presence and pattern of tumor invasion of the mandible in oral squamous cell carcinoma (SCC). Many authors have questioned increasing the classification of small tumors to T4 on the basis of mandibular invasion alone. There are little data on the influence of the pattern of invasion on prognosis.

Methods.

We prospectively reviewed 100 consecutive mandibular resections for previously untreated oral SCC. Clinical and pathologic data collected included details of soft and hard tissue histologic findings. Outcomes included recurrence (local, regional, and distant metastases), disease‐specific survival, and death from other causes. The median follow‐up for survivors was 65 months.

Results.

Of 100 cases, 65 involved segmental and 35 involved marginal resections. Sixty‐two percent of mandibles were invaded by tumor. Local recurrence occured in 21% and was strongly correlated with tumor size, nodal involvement, and pattern of soft tissue invasion. The 5‐year disease‐specific survival was 68%, and the crude survival was 50%. Mandibular invasion predicted for recurrence and disease‐specific survival, even after correcting for the effects of other variables. The pattern of mandibular invasion (erosive/infiltrative) was also predicted for recurrence and disease‐specific survival.

Conclusions.

Even in the presence of mandibular invasion, soft tissue factors are the most important determinants of prognosis. Upstaging tumors on the basis of mandibular invasion is justified. An infiltrative pattern of bone invasion is a marker of aggressive tumor biology and should be included in the pTNM classification. © 2004 Wiley Periodicals Inc. Head Neck 26: 861–869, 2004
Selenoprotein P, as a predictor for evaluating gemcitabine resistance in human pancreatic cancer cells
Authors: Maehara Shin‐ichiro , Tanaka Shinji , Shimada Mitsuo , Shirabe Ken , Saito Yoshiro , Takahashi Kazuhiko , Maehara Yoshihiko
Published: June 2004

Gemcitabine is a new standard chemotherapeutic agent used in the treatment of pancreatic cancer, but the mechanisms of gemcitabine sensitivity are still controversial. In our study to determine a mechanism that regulates gemcitabine sensitivity, we carried out molecular analysis on the susceptibility of the pancreatic cancer cells. Using a gemcitabine‐sensitive pancreatic cancer cell line KLM1, we established a resistant cell line KLM1‐R exhibiting a 20‐fold IC50‐value (the concentration of gemcitabine causing 50% growth inhibition). Microarray analysis of genes showed specific expression of selenoprotein P, one of the anti‐oxidants, in the KLM1‐R cell line but not in the KLM1 cell line. Administration of selenoprotein P inhibited the gemcitabine‐induced cytotoxicity in the pancreatic cell lines. The levels of intracellular reactive oxygen species (ROS) were increased in the KLM1 cells by gemcitabine, but selenoprotein P suppressed the gemcitabine‐induced ROS levels. Furthermore interferon‐γ suppressed the expression of selenoprotein P mRNA and increased intracellular ROS level, leading to the recovery of the gemcitabine sensitivity in KLM1‐R. These results suggest a novel mechanism that selenoprotein P reduces the intracellular ROS levels, resulting in the insusceptibility to gemcitabine. © 2004 Wiley‐Liss, Inc.
Identification of genes differentially expressed in human hepatocellular carcinoma by a modified suppression subtractive hybridization method
Authors: Dong Xue‐Yuan , Pang Xue‐Wen , Yu Song‐Tao , Su Yan‐Rong , Wang Hong‐Chen , Yin Yan‐Hui , Wang Yue‐Dan , Chen Wei‐Feng
Published: June 2004

To identify differentially expressed genes in human HCC in China, we applied a modified SSH method for cDNA subtraction. Such modification has made the method more effective for subtraction. We have obtained 36 and 24 differentially expressed cDNA fragments after modified SSH from 4 paired samples of human HCC and non‐HCC tissues, respectively. Reverse Northern blotting analysis was performed to further identify the genes differentially expressed in the HCC and non‐HCC tissue samples. There were 25 genes really overexpressed in HCC, and their corresponding encoding molecules may reflect the events of cell accelerated metabolism, proliferation, angiogenesis, anti‐apoptosis, tumorigenesis (TLH107, TFH9) and the potential for metastasis. Of the 25 genes overexpressed in HCC, 5 were novel and their full‐length cDNAs were cloned. These 5 novel genes are functionally associated with the occurrence and development of HCC according to the Database analysis. In the paired non‐HCC tissues, there were 15 genes lowly or not expressed in HCC, and their encoding proteins function as tumor suppressors (TFA3, TFA11), acute‐phase reactive proteins, and the blood plasma proteins that are mainly or exclusively synthesized in the liver. The distinct profiles of the differentially expressed genes in HCC and the paired non‐HCC tissues have partially reflected the genetic alterations during HCC tumorigenesis. The novel HCC‐specific gene TLH6 and the CT antigen encoding gene TLH107 may have diagnostic and therapeutic potentials in HCC and/or other solid cancers. © 2004 Wiley‐Liss, Inc.
Carotenoids, vitamin A and risk of adenomatous polyp recurrence in the polyp prevention trial
Authors: Steck‐Scott Susan , Forman Michele R. , Sowell Anne , Borkowf Craig B. , Albert Paul S. , Slattery Martha , Brewer Brenda , Caan Bette , Paskett Electra , Iber Frank , Kikendall Walt , Marshall James , Shike Moshe , Weissfeld Joel , Snyder Kirk , Schatzkin Arthur , Lanza Elaine ,   The Polyp Prevention Trial Study Group
Published: June 2004

One trial reported beta‐carotene supplementation was protective of adenomatous polyp recurrence in nonsmokers. We now examine the relation of serum and dietary carotenoids and vitamin A to adenomatous polyp recurrence in a subcohort of 834 participants in a low fat, high fiber, high fruit and vegetable dietary intervention, the Polyp Prevention Trial. Multivariate odds ratio (OR) and 95% confidence intervals (CI) of polyp recurrence were obtained using baseline or the average (first 3 years of the trial) carotenoid and vitamin A values after adjustment for covariates. Compared to the lowest quartile of baseline alpha‐carotene concentrations, the OR of multiple polyp recurrence for the highest quartile was 0.55 (95% CI = 0.30–0.99) and the OR of right‐sided recurrence was 0.60 (95% CI = 0.37–0.95). Baseline dietary intakes of alpha‐carotene and vitamin A from food with/without supplements were inversely associated with any recurrence (pfor linear trend = 0.03‐ alpha‐carotene; p = 0.004 and p = 0.007 ‐intakes of vitamin A). Compared to the lowest quartile of averaged beta‐carotene concentrations, the OR of multiple adenomas for the highest quartile was 0.40 (95% CI = 0.22–0.75) with an inverse trend (p = 0.02). The risk was inversely related to averaged: alpha‐carotene concentrations and right‐sided polyps; alpha‐carotene intake and recurrence of any, multiple and right‐sided polyps; beta‐carotene intake and multiple adenoma recurrence; vitamin A from food (with supplements) and each adverse endpoint. Thus, alpha‐carotene and vitamin A may protect against recurrence in nonsmokers and nondrinkers or be indicative of compliance or another healthy lifestyle factor that reduces risk. © 2004 Wiley‐Liss, Inc.
Dibenzo[A,L]pyrene‐induced genotoxic and carcinogenic responses are dramatically suppressed in aryl hydrocarbon receptor‐deficient mice
Authors: Nakatsuru Yoko , Wakabayashi Keiji , Fujii‐Kuriyama Yoshiaki , Ishikawa Takatoshi , Kusama Kaoru , Ide Fumio
Published: June 2004

Dibenzo[a,l]pyrene (DB[a,l]P), a notorious air pollutant, is the most powerful carcinogenic polycyclic aromatic hydrocarbon (PAH) ever tested. Although the carcinogenicity of PAH may be primarily mediated by the aryl hydrocarbon receptor (AhR), the in vivo role of AhR in skin carcinogenesis remains to be defined. In this context, we investigated the genotoxic and carcinogenic responses of the AhR‐deficient mouse skin to DB[a,l]P. A single painting resulted in a striking epidermal hyperplasia in AhR+/+ mice but not in AhR−/− mice. Bromodeoxyuridine‐labeling index and accumulation of p53 protein in epidermal cells of AhR+/+ mice were 8‐ and 33‐fold higher than those of AhR−/− mice, respectively. 32P‐Postlabeling assay for DB[a,l]P‐DNA adducts displayed a 2‐fold increase in the AhR+/+ mouse skin. After DB[a,l]P exposure, AhR−/− mice arranged a nearly 60% reduction in the induction of epidermal cytochrome P450 (CYP)1A1, but CYP1B1 was constitutively expressed in both genotypes of mice, irrespective of DB[a,l]P treatment. As compared with AhR+/+ mice, AhR−/− mice had both significantly lower incidence (100% vs. 33%) and multiplicity (2.7 vs. 0.46) of skin tumors by the complete carcinogenesis study. These observations indicate that a reduced tumor yield in AhR−/− mice may be secondary to reduction of inducible CYP1A1 activation and subsequent DNA adduction. It is evident from our continuous work that although AhR is likely to play a central role in epidermal proliferation and possibly neoplastic transformation, the relative importance of AhR for carcinogenesis may be different among PAH examined. © 2004 Wiley‐Liss, Inc.
Investigation of MRP‐1 protein and MDR‐1 P‐glycoprotein expression in invasive breast cancer: A prognostic study
Authors: Larkin Annemarie , O'Driscoll Lorraine , Kennedy Susan , Purcell Rachel , Moran Elizabeth , Crown John , Parkinson Michael , Clynes Martin
Published: June 2004

The efficacy of breast cancer treatment is limited by the development of resistance to various chemotherapeutic agents. We conducted a retrospective study of the expression of 2 drug resistance efflux pumps, MRP‐1 and MDR‐1 Pgp, in 177 invasive breast carcinomas. Immunohistochemical expression of these proteins was correlated with clinicopathologic characteristics as well as relapse‐free survival (RFS) and overall survival (OS) times. MDR‐1 Pgp was associated strongly with higher histologic grade (grade III). A highly significant association was shown between MDR‐1 Pgp and MRP‐1 expression (p < 0.01), 47.4% of patients expressing both proteins; MRP‐1 was expressed in approximately 61% of patients and MDR‐1, in approximately 66% of patients. No association was shown in the overall group between either MDR‐1 Pgp or MRP‐1 and any of the other clinicopathologic features. Kaplan‐Meier analysis revealed that in a subset of patients with either high‐grade (grade III) stage 1 (node‐negative) or stage 2 (node‐positive) tumours who were treated with surgery followed by adjuvant chemotherapy, MRP‐1 expression in <25% of tumour cells at diagnosis was significantly associated with improved RFS (p < 0.02) and OS (p < 0.02). Using multivariate analysis, MRP‐1 expression in <25% of tumour cells at diagnosis was identified as an independent, significant prognostic factor for RFS (p < 0.01) and OS (p < 0.01) in this patient group but not in other groups. In this subgroup, no significant correlation was observed between expression of MDR‐1 Pgp and MRP‐1. While the number of patients with high‐grade tumours treated with adjuvant chemotherapy was small and further confirmatory research is warranted, it appears that assessment of MRP‐1 expression at diagnosis may offer useful prognostic information in subgroups of patients with stage 1 or stage 2 high‐grade tumours who receive CMF‐based adjuvant chemotherapy. Given the known substrate specificities of MRP‐1, any mechanistic relationship between MRP‐1 expression and CMF resistance remains unclear. No association was shown between MDR‐1 Pgp expression and either RFS or OS time in any subgroup of patients. © 2004 Wiley‐Liss, Inc.
Expression of transforming growth factor‐beta 1 and growth in soft agar differentiate prostate carcinoma‐associated fibroblasts from normal prostate fibroblasts
Authors: San Francisco Ignacio F. , DeWolf William C. , Peehl Donna M. , Olumi Aria F.
Published: June 2004

Carcinoma‐associated fibroblasts (CAF) promote tumor progression of pre‐neoplastic epithelial cells. To investigate the basis of this phenomenon, we compared the properties of fibroblasts cultured from normal human prostate (NHPF) to prostate CAF. NHPF and CAF were assayed for growth potential, cell death and proliferative capacity by measuring population doubling time, cell cycle distribution and capability to form colonies in soft agar. Resistance to genotoxic (UV radiation: 0–50 J/cm2) and chemotoxic (0–200 nM Taxol) agents were compared between CAF and NHPF by measuring cell viability and cell cycle analysis. Transforming growth factor β1 (TGF‐β1) immunoreactivity was assessed in non‐malignant and malignant prostatic tissue. No detectable differences were found when comparing CAF and NHPF with respect to population doubling time, cell cycle distribution and response to genotoxic and chemotoxic agents. The mean number of colonies in soft agar was 120.5 for CAF vs. 18.2 for NHPF (p < 0.05). Because TGF‐β1 and matrix metalloproteinase (MMP)‐9 have been associated with growth of fibroblasts in soft agar and tumor promotion, we measured the expression of these factors in NHPF and CAF by ELISA. There was no difference in expression of MMP‐9; however, TGF‐β1 was expressed in higher concentrations in CAF than in NHPF (p < 0.0014). Furthermore, TGF‐β1 expression was higher in the carcinoma‐associated stroma of prostate cancer tissue than stroma of non‐malignant prostatic tissue. Increased capability of CAF as compared to NHPF to form colonies in soft agar may be due to a higher expression of TGF‐β1 and correlates with the ability of CAF to promote malignant progression of prostate epithelial cells. © 2004 Wiley‐Liss, Inc.
The tumor‐suppressive reagent taurolidine is an inhibitor of protein biosynthesis
Authors: Braumann Chris , Henke Wolfgang , Jacobi Christoph A. , Dubiel Wolfgang
Published: June 2004

Taurolidine has been successfully used as a disinfectant and to prevent the spreading and growth of tumor cells after surgical excision. However, the underlying mechanisms regarding its effects remain obscure. Here, we show that taurolidine treatment reduces endogenous levels of IκBα, p105, c‐Jun, p53 and p27 in a dose‐dependent manner in colon adenocarcinoma cells, which can be in part due to massive cell death. Because expression of tested proteins was affected by taurolidine, its influence on protein expression was studied. In the coupled transcription/translation system, taurolidine inhibited c‐Jun expression with an IC50 value of 1.4 mM. There was no or little effect on transcription. In contrast, translation of c‐Jun or p53 mRNA was completely inhibited by taurolidine. To determine which step of translation was affected, prominent complexes occurring in the course of translation were analyzed by density gradient centrifugation. In the presence of taurolidine, no preinitiation translation complex was assembled. Taurolidine also suppressed protein expression in bacteria. Based on our data, we conclude that taurolidine blocks a fundamental early phase of translation, which might explain its effects as a disinfectant and inhibitor of tumor growth. © 2004 Wiley‐Liss, Inc.
Structural studies of bioactivity in sol–gel‐derived glasses by X‐ray spectroscopy
Authors: Skipper Laura J. , Sowrey Frank E. , Pickup David M. , Fitzgerald Victoria , Rashid Rumana , Drake Kieran O. , Lin Zhongjie , Saravanapavan Priya , Hench Larry L. , Smith Mark E. , Newport Robert J.
Published: June 2004

Extended X‐ray absorption fine structure spectroscopy and X‐ray absorption near edge structure, X‐ray fluorescence spectroscopy, and X‐ray powder diffraction have been used to study the local calcium environment in four sol–gel‐derived bioactive calcium silicate glasses of the general formula (CaO)x(SiO2)1−x. The formation of a hydroxyapatite layer on the composition with the highest bioactivity (x = 0.3) with time has been studied, in an in vitro environment, by immersion in simulated body fluid (SBF) at 37°C. The calcium oxygen environment in the four compositions has been shown to be six‐coordinate in character. Both the extended X‐ray absorption fine structure spectroscopy and X‐ray absorption near edge structure show a gradual increase in coordination number and CaO bond distance with longer exposure to SBF. X‐ray fluorescence show that calcium is quickly lost from the samples on exposure to SBF and the calcium concentration then recovers with time. There is clear evidence that the recovery of calcium content is due to the formation of a CaO‐P2O5‐rich layer. Annealing of samples at 650°C shows the presence of what, on the length scales probed by X‐ray diffraction, appears to be noncrystalline calcium phosphate after 1 h of exposure to an SBF solution, which becomes more crystalline on longer exposure. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 354–360, 2004
Effect of heat pressing on the mechanical properties of a mica‐based glass‐ceramic
Authors: Denry I. L. , Holloway J. A.
Published: June 2004

Previous work has shown that heat pressing of mica‐based glass‐ceramics can lead to crystal alignment along the direction of pressing. The purpose of this study was to evaluate the effect of heat pressing on the fracture toughness of mica‐based glass‐ceramics. Glass rods (12 × 60 mm) were prepared by melting the glass composition at 1400 °C for 2 h. Ingots (12 × 12 mm; n = 5) and discs (12 × 1.5 mm; n = 10) were cut from the rods. The discs were heat treated to simulate heat pressing and served as controls. A machinable mica‐based glass‐ ceramic (Dicor MGC) also served as control. Bar‐shaped wax patterns (2 × 4 × 22mm) were invested and heat pressed at 875 °C. The elastic constants were determined with the use of the pulsed ultrasonic velocity method. The fracture toughness was measured by the indentation strength technique. The degree of texture was assessed qualitatively by X‐ray diffraction and quantitatively on digital SEM micrographs. The results showed that the mean fracture toughness of the heat‐pressed specimens (1.96 ± 0.19 MPa · m0.5) was significantly higher than that of the heat‐treated controls (1.51 ± 0.21 MPa · m0.5) or the proprietary mica glass‐ceramic (Dicor MGC; 1.66 ± 0.04 MPa · m0.5) (p < .001). It was concluded that heat pressing led to a significant increase in fracture toughness in mica glass‐ceramics because of crystal alignment along the direction of pressing. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 70B: 37–42, 2004