bluuebunny/crossref_metadata_2025 huggingface dataset:
The MLH1 −93 G>A promoter polymorphism and genetic and epigenetic alterations in colon cancer
Authors: Samowitz Wade S. , Curtin Karen , Wolff Roger K. , Albertsen Hans , Sweeney Carol , Caan Bette J. , Ulrich Cornelia M. , Potter John D. , Slattery Martha L.
Published: July 2008

The MLH1 −93 G>A promoter polymorphism has been reported to be associated with an increased risk of microsatellite unstable colorectal cancer. Other than microsatellite instability, however, the genetic and most epigenetic changes of tumors associated with this polymorphism have not been studied. We evaluated associations between the −93 G>A polymorphism and CpG island methylator phenotype (CIMP), BRAF V600E mutations, and MLH1 methylation in tumors from a sample of 1,211 individuals with colon cancer and 1,968 controls from Utah, Northern California, and Minnesota. The −93 G>A polymorphism was determined by the five prime nuclease assay. CIMP was determined previously by methylation‐specific PCR of CpG islands in MLH1, methylated in tumors (MINT)1, MINT2, MINT31, and CDKN2A (p16). The BRAF V600E mutation was determined by sequencing exon 15. The MLH1 −93 G>A promoter polymorphism was associated with CIMP (odds ratio (OR) 3.44, 95% confidence interval (CI) 1.85, 6.42), MLH1 methylation (OR 4.16, 95%CI 2.20, 7.86), BRAF mutations (OR 4.26, 95%CI 1.83, 9.91), and older age at diagnosis (OR 3.65, 95%CI 2.08, 6.39) in microsatellite unstable tumors. These associations were not observed in stable tumors. Increased age at diagnosis and tumor characteristics of microsatellite unstable tumors associated with MLH1 −93 G>A suggests the polymorphism is acting at a relatively late stage of colorectal carcinogenesis to drive CIMP+ tumors down the microsatellite instability pathway. © 2008 Wiley‐Liss, Inc.
High‐resolution molecular cytogenetic analysis of Wilms tumors highlights diagnostic difficulties among small round cell kidney tumors
Authors: Stewénius Ylva , Jin Yuesheng , Øra Ingrid , Panagopoulos Ioannis , Möller Emely , Mertens Fredrik , Sandstedt Bengt , Alumets Jan , Åkerman Måns , Merks Johannes HM , de Kraker Jan , Gisselsson David
Published: July 2008

Many solid tumors exhibit characteristic gene fusions, which are reflected by balanced translocations at the cytogenetic level. These changes might be useful diagnostic and prognostic tools. In Wilms tumor (WT, nephroblastoma) no fusions genes or recurrent balanced translocations have been described thus far. To screen for cryptic balanced translocations, we have analyzed 17 renal neoplasms, histopathologically classified as WT, by a combination of G‐banding, multicolor FISH, and subtelomeric FISH. This approach revealed several submicroscopic chromosomal aberrations and three different seemingly balanced translocations, resulting in a heterozygous deletion of HACE1, an EWSR1/ERG fusion, and an EWSR1/FLI1 fusion, respectively. As EWSR1 rearrangements are known to be a characteristic of Ewing tumors (ET), our findings illustrate the diagnostic problems regarding small cell kidney tumors and strongly argue for the need of adjuvant diagnostic techniques in this group of neoplasms. In summary, our genomic screening approach proved efficient in finding structural chromosomal aberrations. The fact that no recurrent translocations were found in the WTs of this study argues against the presence of a frequent pathognomonic translocation in this disease entity. © 2008 Wiley‐Liss, Inc.
Stably transfected common fragile site sequences exhibit instability at ectopic sites
Authors: Ragland Ryan L. , Glynn Michael W. , Arlt Martin F. , Glover Thomas W.
Published: July 2008

Common fragile sites (CFSs) are loci that are especially prone to forming gaps and breaks on metaphase chromosomes under conditions of replication stress. Although much has been learned about the cellular responses to gaps and breaks at CFSs, less is known about what makes these sites inherently unstable. CFS sequences are highly conserved in mammalian evolution and contain a number of sequence motifs that are hypothesized to contribute to their instability. To examine the role of CFS sequences in chromosome breakage, we stably transfected two BACs containing FRA3B sequences and two nonCFS control BACs containing similar sequence content into HCT116 cells and isolated cell clones with BACs integrated at ectopic sites. Integrated BACs were present at just a few to several hundred contiguous copies. Cell clones containing integrated FRA3B BACs showed a significant, three to sevenfold increase in aphidicolin‐induced gaps and breaks at the integration site as compared to control BACs. Furthermore, many FRA3B integration sites displayed additional chromosome rearrangements associated with CFS instability. Clones were examined for replication timing and it was found that the integrated FRA3B sequences were not dependent on late replication for their fragility. This is the first direct evidence in human cells that introduction of CFS sequences into ectopic nonfragile loci is sufficient to recapitulate the instability found at CFSs. These data support the hypothesis that sequences at CFSs are inherently unstable, and are a major factor in the formation of replication stress induced gaps and breaks at CFSs. © 2008 Wiley‐Liss, Inc.
Comprehensive analysis of 20q13 genes in ovarian cancer identifies ADRM1 as amplification target
Authors: Fejzo Marlena S. , Dering Judy , Ginther Chuck , Anderson Lee , Ramos Lilian , Walsh Christine , Karlan Beth , Slamon Dennis J.
Published: July 2008

Approximately 25,000 ovarian cancers are diagnosed in the US annually, and 75% of cases are in the advanced stage when they are largely incurable. There is a critical need for improved early detection tools and development of novel treatments. Because chromosome band 20q13 is a commonly DNA amplified region in ovarian cancer and increase in 20q13 copy number may be an early event, we examined the DNA amplification and RNA expression pattern of 239 microarray probes mapping to this region with the goal of identifying gene(s) associated with ovarian cancer. Using Agilent expression microarray analysis and FISH to tumor tissue arrays, we narrowed the candidates to 19 genes that were consistently overexpressed in a subset of tumors amplified for both ZNF217 and TPD54, although, interestingly the candidates do not include these two amplified genes. Unsupervised clustering of 225 ovarian samples with respect to RNA expression of these 19 genes allowed identification of a 20q‐amplified subset of 51 (23%) tumors and this subset was significantly correlated with poor outcome. Of the 19 candidate genes in this subset, ADRM1 overexpression was the most highly correlated with amplification, was amplified in a higher percentage of tumors than ZNF217 and TPD54, and was significantly upregulated with respect to stage, recurrence and metastasis. In addition, overexpression of ADRM1 correlates significantly with shorter time to recurrence and overall survival. Functional analysis is now warranted to determine whether ADRM1 is a target for early screening and/or therapy for ovarian cancer. © 2008 Wiley‐Liss, Inc.
CANDID: a flexible method for prioritizing candidate genes for complex human traits
Authors: Hutz Janna E. , Kraja Aldi T. , McLeod, Howard L. , Province Michael A.
Published: July 2008

Genomewide studies and localized candidate gene approaches have become everyday study designs for identifying polymorphisms in genes that influence complex human traits. Yet, in general, the number of significant findings and the need to focus on smaller regions require a prioritization of genes for further study. Some candidate gene identification algorithms have been proposed in recent years to attempt to streamline this prioritization, but many suffer from limitations imposed by the source data or are difficult to use and understand. CANDID is a prioritization algorithm designed to produce impartial, accurate rankings of candidate genes that influence complex human traits. CANDID can use information from publications, protein domain descriptions, cross‐species conservation measures, gene expression profiles and protein‐protein interactions in its analysis. Additionally, users may supplement these data sources with results from linkage, association and other studies. CANDID was tested on well‐known complex trait genes using data from the Online Mendelian Inheritance in Man database. Additionally, CANDID was evaluated in a modeled gene discovery environment, where it ranked genes whose trait associations were published after CANDID's databases were compiled. In all settings, CANDID exhibited high sensitivity and specificity, indicating an improvement upon previously published algorithms. Its accuracy and ease of use make CANDID a highly useful tool in study design and analysis for complex human traits. Genet. Epidemiol. 2008. © 2008 Wiley‐Liss, Inc.
Comparative gene expression profiling of olfactory ensheathing glia and Schwann cells indicates distinct tissue repair characteristics of olfactory ensheathing glia
Authors: Franssen Elske H.P. , De Bree Freddy M. , Essing Anke H.W. , Ramon‐Cueto Almudena , Verhaagen Joost
Published: July 2008

Olfactory ensheathing glia (OEG) are a specialized type of glia that support the growth of primary olfactory axons from the neuroepithelium in the nasal cavity to the brain. Transplantation of OEG in the injured spinal cord promotes sprouting of injured axons and results in reduced cavity formation, enhanced axonal and tissue sparing, remyelination, and angiogenesis. Gene expression analysis may help to identify the molecular mechanisms underlying the ability of OEG to recreate an environment that supports regeneration in the central nervous system. Here, we compared the transcriptome of cultured OEG (cOEG) with the transcriptomes of cultured Schwann cells (cSCs) and of OEG directly obtained from their natural environment (nOEG), the olfactory nerve layer of adult rats. Functional data mining by Gene Ontology (GO)‐analysis revealed a number of overrepresented GO‐classes associated with tissue repair. These classes include “response to wounding,” “blood vessel development,” “cell adhesion,” and GO‐classes related to the extracellular matrix and were overrepresented in the set of differentially expressed genes between both comparisons. The current screening approach combined with GO‐analysis has identified distinct molecular properties of OEG that may underlie their efficacy and interaction with host tissue after implantation in the injured spinal cord. These observations can form the basis for studies on the function of novel target molecules for therapeutic intervention after neurotrauma. © 2008 Wiley‐Liss, Inc.
Glial TLR4 receptor as new target to treat neuropathic pain: Efficacy of a new receptor antagonist in a model of peripheral nerve injury in mice
Authors: Bettoni Isabella , Comelli Francesca , Rossini Clara , Granucci Francesca , Giagnoni Gabriella , Peri Francesco , Costa Barbara
Published: July 2008

Neuropathic pain remains a prevalent clinical problem because it is often poorly responsive to the currently used analgesics, thus it is crucial the identification of new potential targets and drugs. Recent evidence indicated that microglial cells in the spinal cord are critically involved in the development and maintenance of neuropathic pain, with a pivotal role of toll‐like receptor 4 (TLR4). Binding of an endogenous ligand to TLR4 might be considered an important step in the regulation of microglia activity in pain facilitation, suggesting that a mechanism aimed to inhibit such a binding could be effective against neuropathic pain. We have synthesized new ligands to TLR4 with antagonistic activity. In the present work we evaluated the efficacy of the most potent TLR4 antagonist synthesized by us (FP‐1), administered in mice with painful neuropathy. The repeated treatment of neuropathic mice with FP‐1 (5–10 mg/kg, i.p.) evoked a relief of both thermal hyperalgesia and mechanical allodynia, whereas the administration of the highest dose to TLR4 knockout neuropathic mice revealed that in the absence of TLR4 receptor, the compound lost its efficacy. As consequence of TLR4 binding, the repeated treatment with FP‐1 prevented the activation of the transcription factor NF‐kB and the TNFα overproduction in the spinal cord. Together, our findings support the previous evidence indicative for a contribution of glial TLR4 to the initiation of neuropathic pain, suggest it as potential innovative target to treat this debilitating disease, and propose FP‐1 as lead compound for the development of new effective drugs. © 2008 Wiley‐Liss, Inc.
The four‐and‐a‐half‐LIM protein 2 (FHL2) is overexpressed in gliomas and associated with oncogenic activities
Authors: Li Ming , Wang Jide , Ng Samuel S. M. , Chan Chu‐Yan , Chen Amy C. , Xia Hong Ping , Yew David T. , Wong Benjamin C. Y. , Chen Zhu , Kung Hsiang‐Fu , Lin Marie Chia‐Mi
Published: July 2008

Four‐and‐a‐half‐LIM protein 2 (FHL2) is a member of FHL protein family, which plays a crucial role in regulating gene expression, cell survival, and migration. Although its function in oncogenesis appears to be tumor type‐specific, its roles in glioma formation and development are yet to be elucidated. In the present study, we demonstrated that the mRNA level of FHL2 was elevated in both low‐ and high‐grade glioma samples. Overexpression of FHL2 stimulated the proliferation, anchorage‐independent growth, and migration of human glioblastoma cells. Conversely, FHL2 knockdown by short hairpin RNA (shRNA‐FHL2) inhibited glioblastoma cell proliferation and migration. Overexpression of FHL2 increased the tumorigenicity of glioblastoma cells in nude mice and decreased the mRNA levels of p53 and its downstream proapoptotic genes, including p21, Bcl2‐associated protein X (Bax), and p53‐upregulated modulator of apoptosis. It also enhanced the promoter activities of activator protein‐1 (AP‐1), human telomerase reverse transcriptase, and survivin genes. Together, these results provide the first evidence that FHL2 contributes to glioma carcinogenesis. © 2008 Wiley‐Liss, Inc.
Morphogenesis and regulation of Bergmann glial processes during Purkinje cell dendritic spine ensheathment and synaptogenesis
Authors: Lippman Jocelyn J. , Lordkipanidze Tamar , Buell Margaret E. , Yoon Sung Ok , Dunaevsky Anna
Published: July 2008

Astrocytes have an important role in synaptic formation and function but how astrocytic processes become associated with synaptic structures during development is not well understood. Here we analyzed the pattern of growth of the processes extending off the main Bergmann glial (BG) shafts during synaptogenesis in the cerebellum. We found that during this period, BG process outgrowth was correlated with increased ensheathment of dendritic spines. In addition, two‐photon time‐lapse imaging revealed that BG processes were highly dynamic, and processes became more stable as the period of spine ensheathment progressed. While process motility was dependent on actin polymerization, activity of cytoskeletal regulators Rac1 and RhoG did not play a role in glial process dynamics or density, but was critical for maintaining process length. We extended this finding to probe the relationship between process morphology and ensheathment, finding that shortened processes result in decreased coverage of the spine. Furthermore, we found that areas in which BG expressed dn‐Rac1, and therefore had a lower level of synaptic ensheathment, showed an overall increase in synapse number. These analyses reveal how BG processes grow to surround synaptic structures, elucidate the importance of BG process structure for proper development of synaptic ensheathment, and reveal a role for ensheathment in synapse formation. © 2008 Wiley‐Liss, Inc.
Cross‐country disparities in health‐care expenditure: a factor decomposition
Authors: Alcalde‐Unzu Jorge , Ezcurra Roberto , Pascual Pedro
Published: July 2008

This note investigates the sources of international differences in the levels of per capita health‐care expenditure, using data on the OECD countries between 1975 and 2003. To that end, we use Theil's second measure of inequality for decomposing cross‐country disparities in per capita health‐care expenditure into the contributions of various factors: health‐care expenditure expressed as a share of GDP, labour productivity, employment rate, activity rate and the ratio of working‐age population to total population. Our results show that cross‐country differences in the share of GDP devoted to health‐care expenditure and labour productivity are the main determinants of the level of dispersion in per capita health‐care expenditure. On the contrary, existing disparities in the remaining explanatory factors considered play a less relevant role in this context. In any event, the analysis performed reveals that the overall inequality in per capita health‐care expenditure decreased throughout the study period. This was due to the process of international convergence observed in most of the factors used to break down the level of per capita health‐care expenditure. Copyright © 2008 John Wiley & Sons, Ltd.
Physician labour supply in Canada: a cohort analysis
Authors: Crossley Thomas F. , Hurley Jeremiah , Jeon Sung‐Hee
Published: July 2008

This paper employs a cohort analysis to examine the relative importance of different factors in explaining changes in the number of hours spent in direct patient care by Canadian general/family practitioners (GPs) over the period 1982–2003. Cohorts are defined by year of graduation from medical school. The results for male GPs indicate that there is little age effect on hours of direct patient care, especially among physicians aged 35–55, there is no strong cohort effect on hours of direct patient care, but there is a secular decline in hours of direct patient care over the period. The results for female GPs indicate that female physicians on average work fewer hours than male physicians, there is a clear age effect on hours of direct patient care, there is no strong cohort effect, and there has been little secular change in average hours of direct patient care. The changing behaviour of male GPs accounted for a greater proportion of the overall decline in hours of direct patient care from the 1980s through the mid‐1990s than did the growing proportion of female GPs in the physician stock. Copyright © 2008 John Wiley & Sons, Ltd.
Parental response to health risk information: experimental results on willingness‐to‐pay for safer infant milk formula
Authors: Goldberg Isabell , Roosen Jutta , Nayga Rodolfo M.
Published: July 2008

Enterobacter sakazakii, a pathogen that can be found in powdered infant milk formula, can cause adverse health effects on infants. Using Vickrey auction, this study examines parents' willingness to pay (WTP) for a quality assurance label on powdered infant milk formula. The influence of ambiguity with the incidence rate information and provision of safe‐handling information on WTP are also evaluated using three experimental treatments. Our findings generally imply that parents significantly value a quality assurance label. The mean price premium parents are willing to pay for the safer and quality assurance labelled powdered infant milk formula ranges from 61 to 133 Eurocents per 100 grams (53–116% of the base price per 100 grams) depending on the treatment. While no ambiguity effects are generally found, provision of safe‐handling information significantly reduced WTP to 39–69 Eurocents per 100 grams depending on the treatment. Copyright © 2008 John Wiley & Sons, Ltd.
Potential for efficacy of the oncolytic Herpes simplex virus 1716 in patients with oral squamous cell carcinoma
Authors: Mace Alastair T. M. , Ganly Ian , Soutar David S. , Brown S. Moira
Published: July 2008

Background.

Herpes simplex virus (HSV) 1716 is a selectively replicating oncolytic virus. Our objective was to assess the potential efficacy of HSV1716 in patients with oral squamous cell carcinoma (SCC) by intratumoral injection.

Methods.

Twenty patients with oral SCC had a single intratumoral injection of HSV1716 at a dose of 105 pfu (plaque forming unit) or 5 × 105 pfu. Injections were done at 1, 3, or 14 days before surgical resection. The tumors were assessed for evidence of viral replication and necrosis. Immunologic response to virus and toxicity was also assessed.

Results.

Intratumoral injections were well tolerated with no adverse effects. Evidence of biological activity was lacking, with no increase in detectable virus in tumor samples.

Conclusion.

Intratumoral injection of HSV1716 is safe but with little evidence for viral replication or efficacy. Further studies at higher doses are required to determine the potential efficacy of this virus in head and neck cancer. © 2008 Wiley Periodicals, Inc. Head Neck 2008
Definitive radiation therapy for squamous cell carcinoma of the soft palate
Authors: Chera Bhishamjit S. , Amdur Robert J. , Hinerman Russell W. , Morris Christopher G. , Villaret Douglas B. , Werning John W. , Mendenhall William M.
Published: July 2008

Background.

We report the University of Florida experience with soft‐palate carcinoma treated with radiotherapy alone or combined with adjuvant chemotherapy and/or neck dissection for residual disease in the neck.

Methods.

A total of 145 patients treated with curative intent from 1963 to 2004 were included. Potential follow‐up was ≥2 years.

Results.

Local control rates at 5 years were: T1, 90%; T2, 91%; T3, 67%; T4, 57%. Nodal control rates at 5 years were: N0, 90%; N1, 82%; N2, 68%; N3, 71%. Ultimate local‐regional control rates at 5 years were: stage I, 89%; stage II, 88%; stage III, 96%; stage IVA, 63%; stage IVB, 43%. In multivariate analysis, overall treatment time significantly affected local and ultimate local‐regional control, and nodal stage significantly affected overall survival. Overall survival rate at 5 years was 44%. Cause‐specific survival rate at 5 years was 73%.

Conclusions.

The likelihood of cure after definitive radiotherapy is relatively high and is impacted by disease extent and overall treatment time. © 2008 Wiley Periodicals, Inc. Head Neck 2008
A 20-year single-center experience with acute liver failure during pregnancy: Is the prognosis really worse?
Authors: Bhatia Vikram , Singhal Amit , Panda Subrat Kumar , Acharya Subrat Kumar
Published: July 2008

Pregnant patients with acute liver failure (ALF) are believed to have a worse outcome than nonpregnant women and men with ALF. However objective data supporting this supposition are scant. Therefore, the current study compared the outcome, complications, and causes of ALF among pregnant women and girls with age-matched nonpregnant women and girls and men and boys with ALF. One thousand fifteen consecutive ALF patients in the reproductive age group, admitted at the All India Institute of Medical Sciences, New Delhi, from January 1986 to December 2006, were included in the study. A total of 249 (38.5%) women were pregnant. They were compared with 341 nonpregnant women and girls and 425 men and boys, aged 15 to 45 years. The mortality rate of pregnant women and girls (53.8%) was similar to age-matched nonpregnant women and girls (57.2%), and men and boys (57.9%);

P

= 0.572.The clinical and biochemical features, disease severity, and complications were also similar in the three groups. A significantly higher proportion of ALF was attributable to hepatitis E virus (HEV) among women and girls who were pregnant (59.4%), as compared with both nonpregnant women and girls (30.4%), and men and boys (23.1%);

P

< 0.001. However, the outcome of HEV-related ALF was independent of the sex and pregnancy status of the patients (

P

= 0.103). Mortality in HEV-ALF and non–HEV-ALF patients in pregnant women and girls was 51% (74/145) and 54.7% (52/95)(

P

> 0.1), respectively. The outcome of pregnant ALF patients was also unrelated to the trimester of pregnancy. The mortality of non–HEV-related ALF among the pregnant women and girls (54.7%), age-matched nonpregnant women and girls (61.7%), and men and boys (62.8%) were also similar (

P

> 0.1).

Conclusion:

The mortality of pregnant patients with ALF is similar to that of nonpregnant women and girls and men and boys and is independent of the cause or trimester. Pregnancy

per se

should not be regarded as a poor prognostic factor for a patient with ALF. (Hepatology 2008.)
Differentiation therapy of hepatocellular carcinoma in mice with recombinant adenovirus carrying hepatocyte nuclear factor-4α gene
Authors: Yin Chuan , Lin Yong , Zhang Xin , Chen Yue-Xiang , Zeng Xin , Yue Hai-Yan , Hou Jun-Liang , Deng Xing , Zhang Jun-Ping , Han Ze-Guang , Xie Wei-Fen
Published: July 2008

Previous studies have shown that hepatocyte nuclear factor-4α (HNF4α) is a central regulator of differentiated hepatocyte phenotype and forced expression of HNF4α could promote reversion of tumors toward a less invasive phenotype. However, the effect of HNF4α on cancer stem cells (CSCs) and the treatment of hepatocellular carcinoma (HCC) with HNF4α have not been reported. In this study, an adenovirus-mediated gene delivery system, which could efficiently transfer and express HNF4α, was generated to determine its effect on hepatoma cells (Hep3B and HepG2)

in vitro

and investigate the anti-tumor effect of HNF4α in mice. Our results demonstrated that forced re-expression of HNF4α induced the differentiation of hepatoma cells into hepatocytes, dramatically decreased “stemness” gene expression and the percentage of CD133+ and CD90+ cells, which are considered as cancer stem cells in HCC. Meanwhile, HNF4α reduced cell viability through inducing apparent apoptosis in Hep3B, while it induced cell cycle arrest and cellular senescence in HepG2. Moreover, infection of hepatoma cells by HNF4α abolished their tumorigenesis in mice. Most interestingly, systemic administration of adenovirus carrying the HNF4α gene protected mice from liver metastatic tumor formation, and intratumoral injection of HNF4α also displayed significant antitumor effects on transplanted tumor models.

Conclusion:

The striking suppression effect of HNF4α on tumorigenesis and tumor development is attained by inducing the differentiation of hepatoma cells—especially CSCs—into mature hepatocytes, suggesting that differentiation therapy with HNF4α may be an effective treatment for HCC patients. Our study also implies that differentiation therapy may present as one of the best strategies for cancer treatment through the induction of cell differentiation by key transcription factors. (Hepatology 2008.)
Evaluation of previously nonscreened hereditary hemorrhagic telangiectasia patients shows frequent liver involvement and early cardiac consequences
Authors: Gincul Rodica , Lesca Gaetan , Gelas-Dore Bénédicte , Rollin Nathalie , Barthelet Martine , Dupuis-Girod Sophie , Pilleul Franck , Giraud Sophie , Plauchu Henri , Saurin Jean-Christophe
Published: July 2008

Hereditary hemorrhagic telangiectasia (HHT) is a genetic disease characterized by cutaneous, mucosal, and sometimes visceral arteriovenous malformations. Severe hepatic manifestations have been characterized in a subgroup of patients, but few data are available in previously nonscreened patients. We prospectively evaluated liver involvement and its cardiac consequences in such patients. Between 2000 and 2005, we prospectively evaluated the clinical, biological, and hepatic Doppler sonography (DS) characteristics of 102 consecutive HHT patients (mean age, 52.5 years; range, 19-88; 80.4%) with an identified genetic mutation. Patients were segregated into three different severity groups according to DS values. Factors predictive of an abnormal DS, according to predetermined criteria, and of a high cardiac index were identified by logistic and linear regression analysis, respectively. Abnormal liver biology and clinical signs of hepatic involvement were present in 35.3% and 27.5% of cases, respectively. Abnormal DS (defined as at least enlargement of the main hepatic artery) was observed in 56 (54.9%) cases, and direct or indirect signs of significant fistulas were present in 26 (25.5%) cases. Abnormal liver biology and a mutation involving the

ACVRL1

gene were predictive of hepatic ultrasound (US) abnormalities. The diameter of the main hepatic artery and the presence of focal nodular hyperplasia (FNH) were predictive of a higher cardiac index.

Conclusion:

This large prospective series of previously nonscreened HHT patients identified a subgroup at risk of liver involvement (patients with abnormal liver biology and

ACVRL1

mutations) and a subgroup with a higher cardiac index: future studies will show whether such patients would benefit from systematic DS screening and long-term cardiac surveillance. (Hepatology 2008;48:1570–1576.)
Leptin induces phagocytosis of apoptotic bodies by hepatic stellate cells via a Rho guanosine triphosphatase–dependent mechanism
Authors: Jiang Joy X. , Mikami Kenichiro , Shah Vijay H. , Torok Natalie J.
Published: July 2008

Leptin, a profibrogenic cytokine, plays an important role in the development of non-alcoholic steatohepatitis. Leptin also regulates immune responses, including macrophage phagocytic activity. Stellate cells are key elements in liver fibrogenesis, and previously we have demonstrated that phagocytosis of apoptotic bodies by stellate cells is profibrogenic. To study the effects of leptin on the phagocytic activity of hepatic stellate cells, we exposed both LX-2 cells and primary stellate cells to leptin, and we have observed increased phagocytic activity. In stellate cells isolated from Zucker (

fa

/

fa

) rats, the rate of phagocytosis was significantly decreased. To investigate the mechanism by which leptin induces phagocytosis, we focused on the role of Rho-guanosine triphosphate (GTP)-ases. We found that leptin induced the PI3K-dependent activation of Rac1, and that nicotinamide adenine dinucleotide phosphate, reduced form (NADPH) oxidase activation was also implicated in this process. Leptin also induced RhoA activation and translocation to the phagosomes. Expression of the constitutive active Rac1 and RhoA both increased the phagocytic rate, whereas inhibition of the Rho-dependent kinase decreased the phagocytic activity.

Conclusion:

We describe a novel role of leptin in the fibrogenic process, the induction of phagocytosis of apoptotic bodies by hepatic stellate cells. The data provide strong evidence of a Rho-GTPase–mediated regulation of the cytoskeleton during stellate cell phagocytosis. Leptin-mediated phagocytic activity of stellate cells therefore could be an important mechanism responsible for progression of fibrosis in non-alcoholic steatohepatitis. (Hepatology 2008.)
Acute promyelocytic leukaemia and acquired α‐2‐plasmin inhibitor deficiency: a retrospective look at the use of epsilon‐aminocaproic acid (Amicar) in 30 patients
Authors: Wassenaar T. , Black J. , Kahl B. , Schwartz B. , Longo W. , Mosher D. , Williams E.
Published: July 2008

Bleeding diathesis and a hyper‐fibrinolytic state often accompany a diagnosis of Acute Promyelocytic Leukaemia (APML). This complication can have grave effects if not successfully treated, with a 10–20% incidence of haemorrhagic death. We hypothesized that α‐2‐antiplasmin levels would correlate with the risk for bleeding, and that administration of epsilon‐aminocaproic acid (EACA) would attenuate that risk. To assess this, we conducted a retrospective chart review analyzing 30 APML patients, 17 of whom were treated with EACA. Thirty patients were treated, 21 with primary induction therapy. Patients with low α‐2‐antiplasmin levels were treated with a coagulopathy protocol consisting of low‐dose heparin, EACA and blood product support. Seventeen patients (57%) developed haemorrhagic complications during their treatment. The presence and grade of haemorrhage appeared to be associated with the α‐2‐antiplasmin level. There were no grade IV haemorrhages or episodes of haemorrhagic death. One episode of central venous catheter associated thromboembolism and three deaths from infection during chemotherapy were observed. α‐2‐Antiplasmin levels are a reliable surrogate for fibrinolysis and haemorrhagic risk in patients with APML. Treatment with EACA is a rational way to pharmacologically inhibit fibrinolysis, is associated with a low incidence of severe haemorrhagic events, and appears to be safe with a low risk of thrombosis. Randomized clinical trials further assessing the efficacy and potential toxicity of EACA in inhibiting fibrinolysis in patients with APML are needed. Copyright © 2008 John Wiley & Sons, Ltd.
Structure–activity relationships for hepatocyte toxicity and electrophilic reactivity ofα,β‐unsaturated esters, acrylates and methacrylates
Authors: Chan Katie , O'Brien Peter J.
Published: July 2008

Covalent binding of reactive electrophiles to cellular targets is a molecular interaction that has the potential to initiate severe adverse biological effects. Therefore, electrophile reactivity towards biological nucleophiles could serve as an important correlate for toxic effects such as hepatocyte death. To determine if reactivity correlates with rat hepatotoxicity,α,β‐unsaturated esters, consisting of acrylates and methacrylates, that are inherently electrophilic and exhibit widely varying degrees of reactivity were investigated. Reactivity was measured using simple assays with glutathione and butylamine as surrogates for soft thiol and hard amino biological nucleophile targets. A linear relationship was observed between hepatotoxicity and thiol reactivity only, while no amine reactivity was observed. Structure–activity relationships were also investigated, with results showing toxicity was well modeled by electronic parametersELUMOand partial charge of the carbon atoms in the reactive center. No relationship was observed between toxicity and logP. These results suggest that differences in hepatocyte toxicity of acrylates and methacrylates can be related to their electrophilic reactivity which corresponds to their ability to deplete GSH and protein thiols. Copyright © 2008 John Wiley & Sons, Ltd.
Polarized Raman microspectroscopy on intact human hair
Authors: Ackermann K. R. , Koster J. , Schlücker S.
Published: July 2008

Polarization‐resolved Raman microspectroscopy with near‐infrared laser excitation was applied to intact human hair in order to non‐invasively investigate the conformation and orientation of the polypeptide chains. By varying the orientation of the hair shaft relative to the polarization directions of the laser/analyzer, a set of four polarized Raman spectra is obtained; this allows to simultaneously determine both the secondary structure of hair proteins and the orientation of the polypeptide strands relative to the axis of the hair shaft. For the amide I band, results from a quantitative analysis of the polarized Raman spectra are compared with theoretically expected values for fibers with uniaxial symmetry. Based on the polarization behavior of the amide I band and further vibrational bands, a partial ordering of α‐helical polypeptide strands parallel to the hair shaft can be concluded. We suggest that this microspectroscopic approach may be used for human hair diagnostics by detecting structural or orientational alterations of keratins. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Perspectives for spatially resolved molecular spectroscopy – Raman on the nanometer scale
Authors: Deckert‐Gaudig T. , Bailo E. , Deckert V.
Published: July 2008

Nano‐objects and cellular components are of great interest in biological sciences. Tip‐enhanced Raman scattering (TERS) is a tool that allows addressing of such features for structural investigations without the need of further labelling. After brief introduction to the basic aspects of the technique an overview of present application of TERS is given. For this contribution we picked TERS experiments with emphasis on its application in life sciences.

Based on these experiments, the future perspective of this analytical method and its limitations is discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chitosan/poly(L‐lactic acid) multilayered membrane for guided tissue regeneration
Authors: Ku Young , Shim In Kyong , Lee Jue Yoen , Park Yoon Jeong , Rhee Sang‐Hoon , Nam Sung Heon , Park Jun Beom , Chung Chong Pyoung , Lee Seung Jin
Published: July 2008

A chitosan/poly(L‐lactic acid) (PLLA) multilayered membrane was prepared for the purpose of guided tissue regeneration (GTR). The membrane was composed of the outer layers of chitosan mesh and the middle layer of nanoporous PLLA membrane. The outer membranes of chitosan fibrous mesh present a highly biocompatible and rough surface for ease of cell adherence. The PLLA membrane is intended to provide mechanical strength to the membrane, thereby preventing epithelial invasion. The PLLA membrane was applied as a local drug delivery carrier for growth factors. Regular pores in PLLA membrane were generated through phase inversion of polymer solution. The membrane retained its integrity during the degradation process in vitro (for up to 8 weeks), which is a requirement for providing enough space in vivo in the GTR procedure. Osteoblasts firmly attached to broad cytoplasmic extensions along with the microfibers of the membrane. The phenotypic expression of cultured osteoblasts on the membrane was measured by a reverse transcriptase‐polymerase chain reaction. New bone had formed beneath the chitosan/PLLA membrane. These results suggested that the chitosan/PLLA membranes properly functioned as biocompatible and mechanically stable barriers for GTR. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Inverted human umbilical arteries with tunable wall thicknesses for nerve regeneration
Authors: Crouzier Thomas , McClendon Trosper , Tosun Zehra , McFetridge Peter S.
Published: July 2008

Tubular nerve guides have shown a potential to bridge nerve defects, by directing neuronal elongation, localizing growth factors, and inhibiting fibrotic cellular ingrowth. These investigations describe a novel acellular scaffold derived from the human umbilical cord artery that aims to enhance nerve regeneration by presenting a unique mechanical and chemical environment to the damaged nerve ends. A rapid, semiautomated dissection technique is described that isolates the human umbilical artery (HUA) from the umbilical cord, after which the vessel is decellularized using sodium dodecyl sulfate (SDS). The artery is turned inside out to produce a 3D scaffold, that unlike previous vessels for nerve repair, is more resistant to collapse. The scaffold has the potential as either an acellular bridge‐implant, or for in vitro nerve regeneration. Stress–strain relationships and suture retention were assessed to determine whether the material had similar mechanical properties to native nerves. A dual process‐flow perfusion bioreactor was developed to assess glucose mass transfer, and to investigate the culture of neuronal‐like PC12 cells within the scaffold. These investigations have shown the automated dissecting method yields a smooth tubular scaffold, where wall thickness can be tuned to alter the mechanical behavior of the scaffold. Inverting the scaffold prevents collapse, with the decellularized iHUA having comparable mechanical properties to native nerves. Bioreactor cultures with PC12 cells seeded within iHUA lumenal void were shown to adhere and migrate into the preexisting ECM after 11 days of culture. These investigations show the potential of the iHUA as a unique 3D scaffold that may enhance nerve regeneration. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Permeability changes of the cell‐contained microcapsules visualized by confocal laser scanning microscope
Authors: Lv Guojun , Sun Zhijie , Li Shuangyue , Yu Weiting , Xie Yubing , Zhang Ying , Xie Hongguo , Li Xiaoxia , Wang Wei , Ma Xiaojun
Published: July 2008

Microencapsulation of recombinant cells is a novel means for gene therapy. However, one of the major concerns is the relationship between the permeability of microcapsule and cell growth. Many studies have focused on the permeability of empty microcapsule, but little is known about the effect of the cell growth on the permeability of a cell‐contained microcapsule. A combination of fluorescence labeled protein and confocal laser scanning microscope (CLSM) provides the information about the permeability changes during the cell growth. A decrease of membrane permeability was detected on the 14th day. Meanwhile, membrane surface protein fouling was also investigated. A significant increase of membrane surface protein content was detected on the 21st day. In order to study the effect of the permeability changes on the cell viability, the membrane of cell‐contained microcapsules with different permeability was set up by incubating gel beads in poly‐L‐lysine for 5 and 30 min, respectively, to mimic the bovine serum albumin cutoff, and a retard of cell growth was found in 7 days' culture. These results showed that the protein fouling of the microcapsule membrane caused by the cell growth may be an important factor to influence cell viability. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Novel apatite fiber scaffolds can promote three‐dimensional proliferation of osteoblasts in rodent bone regeneration models
Authors: Morisue Hikaru , Matsumoto Morio , Chiba Kazuhiro , Matsumoto Hideo , Toyama Yoshiaki , Aizawa Mamoru , Kanzawa Nobuyuki , Fujimi Takahiro J. , Uchida Hiroshi , Okada Isao
Published: July 2008

We have successfully synthesized hydroxyapatite fibers via a homogenous precipitation method. Using these hydroxyapatite fibers, we have produced the apatite fiber scaffolds (AFS) with well‐controlled pore sizes (porosity above 95%). The AFS is relatively simple to synthesize, and its porosity and pore size are controllable. The usefulness of AFS as a scaffold for bone regeneration was evaluated by (1) seeding and culturing cells in the AFS in vitro, (2) implanting the AFS seeded with cells inside the subcutaneous tissue of mice. The AFS had biocompatibility to support cell adhesion, proliferation, and differentiation. Ectopic bone formation could be formed in the AFS at 12 weeks after implantation into the subcutaneous tissue. Because of its high interpore connection, pore diameters, and porosity, it was believed that AFS was an effective scaffold that provided a three‐dimensional cell culture environment. In both in vitro and in vivo environments, the more porous AFS was more advantageous in cell proliferation, cell adhesion, proliferating capacity, robust cell differentiation, ultimately inducing bone ingrowth inside the scaffolds. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Current developments and future prospects for heart valve replacement therapy
Authors: Kidane Asmeret G. , Burriesci Gaetano , Cornejo Patricia , Dooley Audrey , Sarkar Sandip , Bonhoeffer Philipp , Edirisinghe Mohan , Seifalian Alexander M.
Published: July 2008

Valve replacement is the most common surgical treatment in patients with advanced valvular heart disease. Mechanical and bio‐prostheses have been the traditional heart valve replacements in these patients. However, currently the heart valves for replacement therapy are imperfect and subject patients to one or more ongoing risks, including thrombosis, limited durability, and need for re‐operations due to the lack of growth in pediatric populations. Furthermore, they require an open heart surgery, which is risky for elderly and young children who are too weak or ill to undergo major surgery. This article reviews the current state of the art of heart valve replacements in light of their potential clinical applications. In recent years polymeric materials have been widely studied as potential prosthetic heart valve material being designed to overcome the clinical problems associated with both mechanical and bio‐prosthetic valves. The review also addresses the advances in polymer materials, tissue engineering approaches, and the development of percutaneous valve replacement technology and discusses the future prospects in these fields. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Influence of different air‐abrasive powders on cell viability at biologically contaminated titanium dental implants surfaces
Authors: Schwarz Frank , Ferrari Daniel , Popovski Kristian , Hartig Brigitte , Becker Jürgen
Published: July 2008

Studies have indicated that oral biofilm formation at structured titanium surfaces interferes with cell adhesion and proliferation, and its removal by means of conventional treatment procedures may not be sufficient to render these surfaces biologically acceptable. Therefore, the aim of the study was to evaluate the influence of different air‐abrasive powders on cell viability at biologically contaminated titanium dental implant surfaces. Intraoral splints were used to collect an in vivo biofilm on sandblasted and acid‐etched titanium discs for 48 h. A single (1x) and repeated (2x) use of four different powders (amino acid glycine or sodium bicarbonate particles; range of mean particle size (dv50):20—75 μm) was applied at two distances (1 and 2 mm) and angles (30° and 90°) to the surfaces. Specimens (2x) were incubated with SaOs‐2 cells for 7 days. Residual biofilm (RB) areas (%), and surface alterations (SEM) (1x and 2x), as well as SaOs‐2 cell viability, expressed as mitochondrial cell activity (MA) (counts/second) (2x specimens), were assessed. Comparable mean RB areas were observed within and between groups after both 1x (RB: 0.0% ± 0.0% to 5.7% ± 5.7%) and 2x (RB: 0.0% ± 0.0%) treatments. All surface treatments did not lead to MA (2x) values comparable to the sterile control group. However, sodium bicarbonate particles resulted in significantly higher MA (2x) values than amino acid glycine powders of different sizes. This was associated with pronounced alterations of the surface morphology (2x). Within the limits of the present study, it was concluded that SaOs‐2 cell viability at biologically contaminated titanium surfaces was mainly influenced by the particle type of the powder. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Structure and surface reactivity of novel nanoporous alumina fillers
Authors: Azevedo Christophe , Tavernier Bruno , Vignes Jean‐Louis , Cenedese Pierre , Dubot Pierre
Published: July 2008

Recent studies have shown that the particle size of fillers used for the reinforcement of dental resin composites should be multimodally distributed, in which micron‐sized fillers are mixed with nanoparticles so as to achieve a higher filler level in the resin, and should be kept well dispersed so as to be functionalized by a silane. In this study, porous alumina monoliths with high specific surface area, measured by the Brunauer‐Emmett‐Teller (BET) method, were obtained using a novel preparation method. Structure and surface reactivity have been investigated as functions of temperature and chemical treatments. The impregnation of the as‐prepared material by triméthyletoxysilane (TMES) stabilized alumina with high specific surface area at higher temperature. FTIR study has described the effect of TMES treatment and temperature on the structure of the material. The use of allyldimethoxysilane (ADMS), as a probe molecule for measuring the surface reactivity, has allowed us to show that the treatment of samples with TMES and their reheating at 1300°C results in adsorption sites which give stronger chemical bonds. This preliminary study has, therefore, allowed us to optimize the structural and surface treatment of experimental fillers before their use in the reinforcement of resin composites or resin‐modified glass ionomer cements. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009