bluuebunny/crossref_metadata_2025 huggingface dataset:
Cholangiocarcinoma in Association With Caroli's Disease
Authors: Maharaj Paramanand , Khan Omar , Thomas Alan , Naipaul Rene
Published: March 2006

Caroli's disease is a rare congenital disorder characterized by focal or diffuse dilatation of the intrahepatic bile ducts. If asymptomatic, this condition may remain undetected for several years. We present a case of focal Caroli's disease, first suspected on sonography, with a coexisting bile duct carcinoma. Both computed tomography (CT) imaging and percutaneous transhepatic cholangiography (PTC) supported a diagnosis of Caroli's disease but did not detect the presence of an associated mass, which was histologically proved to be a bile duct carcinoma. The advantages and disadvantages of different modalities in evaluating Caroli's disease are discussed.
Antenatal Diagnosis of a Suprarenal Mass
Authors: Hai Jolyn K. , Mitchell Carol K. Chenoweth , Wickstrom Elizabeth
Published: March 2006

Pulmonary sequestration is a malformation of the embryonic foregut defined as a mass of nonfunctioning pulmonary tissue that does not connect to the tracheobronchial tree. Prenatal diagnosis of subdiaphragmatic pulmonary sequestration has become more common. This report describes a case of a suprarenal mass identified at 24 weeks' gestation and the differential diagnosis that should be considered.
Ultrasound Safety
Authors: Felkel Stephen E.
Published: March 2006

There have been no reports of human injury attributable to ultrasound exposure since the first examinations were done in the 1950s. Epidemiologic research has proved extremely difficult because of the large number of variables involved, but there is a substantial body of research reporting the disrupting potential of ultrasound exposure on cells, plants, and animals. The Output Display Standard was introduced in 1992 in the interest of increasing the diagnostic capabilities of the medium. It removed application-specific intensity limits and replaced them with indices that are intended to guide the safe administration of examinations. However, the threshold of injury remains elusive. In light of this change, it becomes imperative to understand the dynamics of sound, the conditions that could potentially cause adverse bioeffects, and the controls that can help keep exposure to ultrasound energy as low as reasonably achievable (ALARA).
Retrospective Cost Analysis of Ultrasound Versus Computed Tomography Guided Nonvascular Invasive Radiologic Procedures at a Community-Based Hospital
Authors: Konez Orhan , Nazinitsky Kenneth J. , Goyal Manish , Kellermeyer Scott A. , Hissong Samuel L. , Ciaverella David P.
Published: March 2006

The study compares the cost analysis of ultrasound versus computed tomography guidance for nonvascular invasive procedures. Ultrasound and computed tomography-guided invasive procedures are performed routinely in all radiology departments. However, in many departments computed tomography guidance is preferred to ultrasound, sometimes without valid medical indication, aside from personal preference or training. In the authors' department, all requests for imaging-guided nonvascular procedures initially are evaluated for the possibility of ultrasound guidance. This retrospective study included 2971 patients who underwent invasive procedures with ultrasound and computed tomography guidance during a 4-year period (1994-1997). Outcomes were compared to those of another community-based hospital in the same area. The cost analysis was made based on Health Care Financing Administration/ Medicare reimbursements. The results show that approximately 10% of patients can be redirected from computed tomography-guided procedures to ultrasound guidance.
The Use of Ultrasound to Identify Fetuses with Down Syndrome
Authors: Durbin Sharon A.
Published: March 2006

Karyotyping by invasive prenatal testing such as amniocentesis or chorionic villi sampling is the only definitive method of determining Down syndrome. However, both methods are associated with procedure-related risks. The combination of two noninvasive tools, the maternal serum triple screen and the ultrasound examination, provides a way of identifying fetuses at higher risk for Down syndrome. Ultrasound markers are sonographic findings that may exist as structural malformations or normal variants that are more prevalent in Down syndrome. Depending on the particular marker, either a single marker or a cluster may indicate an increased risk of an affected fetus. Sonographic markers include duodenal atresia, cardiac defects, brachycephaly, mild ventriculomegaly, flattened facial profile, thickened nuchal skin fold, fetal hydrops, hyperechoic bowel, choroid plexus cysts, pyelectasis, shortened extremities, echogenic intracardiac foci, greater iliac wing angle, and specific findings in the fetal hand and foot.
A Honeycomb Appearance of the Fetal Choroid Plexus
Authors: Petrikovsky Boris , Smith-Levitin Michelle , Gross Beth
Published: March 2006

A honeycomb appearance of the choroid plexus in second-trimeste fetuses was first described by Nyberg et al who reported four fetuses with multiple small cysts that formed a “honeycomb” appearance. This is a report of an experience with this entity in second-trimeste fetuses referred for comprehensive ultrasound examination and genetic amnio-centesis.
Sonographic Evaluation of an Abnormal Location of an Intrauterine Device
Authors: Kent Martha G.
Published: March 2006

Ultrasound has been used to locate intrauterine devices for many years and continues to be considered one of the best ways to visualize the presence and location of an intrauterine device. Using a transvaginal approach ultrasound can be used to identify intauterine device expulsion and translocation, organ perforation, and incorectly placed devices. Although no longer a popular method of birth control in the United States, the intrauterine device remains the most common reversible form of contraception used worldwide. The intrauterine device is the most cost effective method of birth control if used more than 2 years. One rare complication of intrauterine device use is translocation of the device. An intrauterine device that has moved from the fundus of the uterus can become imbedded in the myometrium and can even perforate the uterus and move into the abdomen or pelvis. Intrauterine devices have been reported to perforate the intestine and the bladder. This case illustrates the ultrasound appearance of a perforation caused by an intrauterine device.
Ultrasound of Abdominal Wall Hernias
Authors: Rapp Cynthia L. , Stavros A. Thomas , Kaske Terese I.
Published: March 2006

Abdominal hernias are a common clinical entity and can be a diagnostic challenge. Sonographic evaluation can provide not only realtime diagnosis of a potential hernia, but this modality also offers the added advantage of dynamic maneuvers. Consequently, hernia contents as well as reducibility, can be determined. Ultrasound should be the primary modality for evaluation of suspected abdominal wall hernias.
Congenital Cystic Adenomatoid Malformation of the Lung—Type III
Authors: Ratner Amy N. , Frisoli Garry
Published: March 2006

Congenital cystic adenomatoid malformation of the lung (CCAML) is a hamartoma of the plung resulting from the overgrowth of terminal respiratory elements (adenomatoid). The lesion is almost always unilateral, with no lobe or gender preference. CCAML has been classified into three tpes, depending on the size of the cysts. Type I consists of one or several large cysts. ranging from 2 to 10 cm in diameter. Type II has multiple small cysts less than 1.5 cm in diameter. Type III is made up of a large solid mass affecting the entire lobe. The following case report is of a fetus diagnosed at 22 weeks with congenital cystic adenomatoid malformation of the lung type III.
Mutations in neutrophil elastase causing congenital neutropenia lead to cytoplasmic protein accumulation and induction of the unfolded protein response
Authors: Köllner Inga , Sodeik Beate , Schreek Sabine , Heyn Holger , von Neuhoff Nils , Germeshausen Manuela , Zeidler Cornelia , Krüger Martin , Schlegelberger Brigitte , Welte Karl , Beger Carmela
Published: March 2006

Severe congenital neutropenia (SCN) and cyclic neutropenia (CyN) are sporadic or inherited hematologic disorders of myelopoiesis. Heterozygous mutations in the gene encoding neutrophil elastase (ELA2) have been reported in both diseases. We used an inducible system to express a panel of ELA2 mutations and found for almost all mutants disruption of intracellular neutrophil elastase (HNE) protein processing at different levels. This disruption resulted in cytoplasmic accumulation of a nonfunctional protein, thereby preventing its physiologic transport to azurophil granules. Furthermore, the secretory capacity of the mutant proteins was greatly diminished, indicating alteration of the regulated and the constitutive pathways. Through analysis of primary granulocytes from SCN patients carrying ELA2 mutations, we found an identical pattern of intracellular accumulation of mutant HNE protein in the cytoplasm. Moreover, cells expressing mutant HNE protein exhibited a significant increase in apoptosis associated with up-regulation of the master ER chaperone BiP, indicating that disturbance of intracellular trafficking results in activation of the mammalian unfolded protein response.
Matrix metalloproteinase-9 promotes neutrophil and T cell recruitment and migration in the postischemic liver
Authors: Khandoga Andrej , Kessler Julia S , Hanschen Marc , Khandoga Alexander G , Burggraf Dorothe , Reichel Christoph , Hamann Gerhard F , Enders Georg , Krombach Fritz
Published: March 2006

Matrix metalloproteinases-2 and -9 (MMP-2/9) are critically involved in degradation of extracellular matrix, and their inhibition is discussed as a promising strategy against hepatic ischemia-reperfusion (I/R) injury. Here, we analyzed the role of MMP-2 and -9 for leukocyte migration and tissue injury in sham-operated mice and in mice after I/R, treated with a MMP-2/9 inhibitor or vehicle. Using zymography, we show that the MMP-2/9 inhibitor abolished I/R-induced MMP-9 activation, whereas MMP-2 activity was not detectable in all groups. As demonstrated by intravital microscopy, MMP-9 inhibition attenuated postischemic rolling and adherence of total leukocytes in hepatic postsinusoidal venules, CD4+ T cell accumulation in sinusoids, and neutrophil transmigration. These effects were associated with reduction of plasma tumor necrosis factor α (TNF-α) levels and endothelial expression of CD62P. Motility of interstitially migrating leukocytes was assessed by near-infrared reflected light oblique transillumination microscopy in the postischemic cremaster muscle. Upon MMP-9 blockade, leukocyte migration velocity and curve-line and straight-line migration distances were reduced significantly as compared with the vehicle-treated I/R group. Postischemic sinusoidal perfusion failure, hepatocellular apoptosis, and alanine aminotransferase activity were only slightly reduced after MMP-9 inhibition, whereas aspartate aminotransferase activity and mortality were significantly lower. In conclusion, MMP-9 is involved in the early recruitment cascades of neutrophils and CD4+ T cells, promotes neutrophil and T cell transmigration during hepatic I/R, and is required for motility of interstitially migrating leukocytes. MMP-9 blockade is associated with an attenuation of TNF-α release and endothelial CD62P expression, weakly protects from early microvascular/hepatocellular I/R damage, but improves postischemic survival.
LTA recognition by bovine γδ T cells involves CD36
Authors: Lubick Kirk , Jutila Mark A
Published: March 2006

CD36 has recently been shown to facilitate monocyte Toll-like receptor 2 (TLR2) recognition of lipoteichoic acid (LTA), much like CD14 in TLR4 recognition of lipopolysaccharide. We previously found that bovine γδ T cells express CD36 transcripts. Here, we tested whether bovine γδ T cells express CD36 protein and if so, whether it functions in a manner similar to the monocyte molecule. CD36 transcripts and internal and cell surface protein could be detected in resting, sorted γδ T cells. Phorbol 12-myristate 13-acetate (PMA)/ionomycin treatment increased CD36 transcript levels (detectable at 4 h) and protein expression (internal and cell surface). Increased surface antigen expression was detectable by 24 h and was maximal at 72 h following PMA/ionomycin stimulation. Anti-CD36 monoclonal antibody inhibited increased macrophage-inflammatory protein-1α gene expression in γδ T cells activated by LTA. In conclusion, γδ T cells express CD36, previously thought to be a myeloid and endothelial cell-restricted surface antigen, and it contributes to responses by these cells to microbial LTA.
Scaffolding instruction for reading the Web
Authors: Murray Denise E. , McPherson Pam
Published: March 2006

Research has found that text reading and Web reading, while sharing some similarities, require a different balance of strategies. Adult language learners, especially those with limited previous experience with the Web, may therefore need explicit, scaffolded instruction in order to read the Web. This article reports on teacher action research and demonstrates the scaffolded activities teachers developed to help learners read and navigate the Web. First, a linguistic analysis of web pages was conducted. Through this analysis, it was determined that, while there is much published research on web page design, many web pages that could be used in order to support the ESL curriculum do not employ a readable design. The study then followed a collaborative action research model (Burns, 1999) with five teachers across Australia. The study revealed two distinct, but interrelated, reading activities learners need to engage in to use the Web: reading web pages to find their way around a website (that is, reading to navigate) and navigating web pages in order to find and read information to achieve some other language learning goal (that is, navigating to read). The research indicates that learners can read and navigate with fewer problems and less stress for them and their teachers, if instruction includes carefully scaffolded activities that help learners become independent readers and navigators of the Web.
Endothelially Derived Nitric Oxide Affects the Severity of Early Acetaminophen‐induced Hepatic Injury in Mice
Authors: Salhanick Steven D. , Orlow Daniel , Holt Doug E. , Pavlides Stavros , Reenstra Wende , Buras Jon A.
Published: March 2006

Objectives:
The precise mechanism of hepatocellular toxicity following acetaminophen (APAP) poisoning remains unclear. Nitric oxide is implicated in APAP toxicity as an inflammatory signaling molecule and as a precursor to the free radical peroxynitrate. The effects of inducible nitric oxide synthase (iNOS)‐derived NO in APAP toxicity are known; however, the role of endothelial nitric oxide synthase (eNOS)‐derived NO is unknown. The authors sought to evaluate the effect of eNOS‐derived NO during APAP toxicity.

Methods:
C57BL6/J mice deficient in eNOS (eNOS KO) or iNOS (iNOS KO) and wild‐type mice (WT) were treated with 300 mg/kg APAP. Alanine aminotransferase levels and plasma nitrate and nitrite levels were measured. Hypoxia inducible factor (HIF)‐1α and Glucose Transporter 1 (Glut‐1) levels were determined by Western blot.

Results:
Alanine aminotransferase levels were significantly elevated in all treated animals. Alanine aminotransferase levels were significantly lower in eNOS KO and iNOS KO than in treated WT animals. Plasma nitrate/nitrite levels were significantly higher in WT animals than in iNOS KO and eNOS KO animals. HIF‐1α expression was increased in WT mice and decreased in iNOS KO mice. Glut‐1 is a downstream, indirect marker of HIF function. Glut‐1 expression was increased in WT and eNOS KO mice.

Conclusions:
Deficiency of either iNOS or eNOS results in decreased NO production and is associated with reduced hepatocellular injury following APAP poisoning. HIF‐1α and Glut‐1 levels are increased following APAP poisoning, implying that HIF‐1α is functional during the pathogenic response to APAP poisoning.
The Behavioral Consequences of Terrorism: A Meta‐Analysis
Authors: DiMaggio Charles , Galea Sandro
Published: March 2006

Effective postterrorism public health interventions require the recognition that behavioral consequences are, in fact, the intent of terrorists. The authors searched published and unpublished post‐1980 studies that documented population‐level behavioral and psychological consequences of terrorist incidents, focusing on posttraumatic stress disorder (PTSD). Results were tabulated, and random effects models were used to calculate overall effect sizes. The analysis indicates that in the year following terrorist incidents, the prevalence of PTSD in directly affected populations varies between 12% and 16%. The review also shows that this prevalence can be expected to decline 25% over the course of that year. These prevalence estimates mask great variability, depending on who is being studied, who is conducting the study, and where the event occurred. Higher rates of disease are reported for survivors and rescue workers, and higher overall rates are also reported from studies conducted in Western Europe compared with studies conducted in North America. Prior psychiatric diagnoses are strongly associated with subsequent PTSD and may be a useful triage factor, particularly when considered together with factors such as female gender and direct exposure to events as either a survivor or rescuer. The review indicates that these associations are consistent across study types and environments and represent important variables to consider when developing triage, outreach, and treatment programs.
A Highly Sensitive ELISA D‐Dimer Increases Testing but Not Diagnosis of Pulmonary Embolism
Authors: Kabrhel Christopher , Matts Christina , McNamara Mariah , Katz Jeremy , Ptak Thomas
Published: March 2006

Objectives:
To determine the effect of introducing a rapid enzyme‐linked immunosorbent assay (ELISA) D‐dimer on the percentage of emergency department (ED) patients evaluated for pulmonary embolism (PE), the use of associated laboratory testing, pulmonary vascular imaging, and the diagnoses of PE.

Methods:
Patients evaluated for PE during three 120‐day periods were enrolled: immediately before (period 1), immediately after (period 2), and one year after the introduction of a rapid ELISA D‐dimer in the hospital. The frequency of ED patients evaluated for PE with any test, with D‐dimer testing, and with pulmonary vascular imaging and the frequency of PE diagnosis during each time period were determined.

Results:
The percentage of patients evaluated for PE nearly doubled; from 1.36% (328/24,101) in period 1 to 2.58% (654/25,318) in period 2 and 2.42% (583/24,093) in period 3. The percentage of patients who underwent D‐dimer testing increased more than fourfold; from 0.39% (93/24,101) in period 1 to 1.83% (464/25,318) in period 2 and 1.77% (427/24,093) in period 3. The percentage of patients who underwent pulmonary vascular imaging increased from 1.02% (247/24,101) in period 1 to 1.36% (344/25,318) in period 2 and to 1.39% (334/24,093) in period 3. There was no difference in the percentage of patients diagnosed as having PE in period 1 (0.20% [47/24,101]), period 2 (0.27% [69/25,318]), and period 3 (0.24% [58/24,093]).

Conclusions:
In the study's academic ED, introduction of ELISA D‐dimer testing was accompanied by an increase in PE evaluations, D‐dimer testing, and pulmonary vascular imaging; there was no observed change in the rate of PE diagnosis.
Cardiovascular and Physiologic Effects of Conducted Electrical Weapon Discharge in Resting Adults
Authors: Ho Jeffrey D. , Miner James R. , Lakireddy Dhanunjaya R. , Bultman Laura L. , Heegaard William G.
Published: March 2006

Objectives:
The TASER is a conducted electrical weapon (CEW) that has been used on people in custody. Individuals occasionally die unexpectedly while in custody, proximal to the application of a CEW. In this study, the authors sought to examine the effects of CEW application in resting adult volunteers to determine if there was evidence of induced electrical dysrhythmia or direct cellular damage that would indicate a causal relationship between application of the device and in‐custody death.

Methods:
Human subjects (N= 66) underwent 24‐hour monitoring after a standard CEW application. Blood samples were collected before and after exposure and again at 16 and 24 hours after exposure. A subpopulation (n= 32) had 12‐lead electrocardiography performed at similar time intervals. Blood samples were analyzed for markers of skeletal and cardiac muscle injury and renal impairment. The electrocardiograms were read by a cardiologist blinded to the study. Data were analyzed using descriptive statistics.

Results:
There was no significant change from baseline at any of the four time points for serum electrolyte levels and the blood urea nitrogen/creatinine ratio. An increase in serum bicarbonate and creatine kinase levels was noted at 16 and 24 hours. An increase in serum lactate level was noted immediately after exposure that decreased at 16 and 24 hours. Serum myoglobin level was increased from baseline at all three time points. All troponin levels measured were < 0.3 ng/mL, except for a single value of 0.6 ng/mL in a single subject. This subject was evaluated, and no evidence of acute myocardial infarction or disability was identified. At baseline, 30 of 32 electrocardiograms were interpreted as normal. The two abnormal electrocardiograms were abnormal at baseline and remained the same at all four time points.

Conclusions:
In this resting adult population, the TASER X26 CEW did not affect the recordable cardiac electrical activity within a 24‐hour period following a standard five‐second application. The authors were unable to detect any induced electrical dysrhythmias or significant direct cardiac cellular damage that may be related to sudden and unexpected death proximal to CEW exposure. Additionally, no evidence of dangerous hyperkalemia or induced acidosis was found. Further study in the area of the in‐custody death phenomenon to better understand its causes is recommended.
Adrenocortical Carcinoma: Clinical Update
Authors: Allolio Bruno , Fassnacht Martin
Published: March 2006

Context: Adrenocortical carcinoma (ACC) is a rare and heterogeneous malignancy with incompletely understood pathogenesis and poor prognosis. Patients present with hormone excess (e.g. virilization, Cushing’s syndrome) or a local mass effect (median tumor size at diagnosis > 10 cm). This paper reviews current diagnostic and therapeutic strategies in ACC.

Evidence Acquisition: Original articles and reviews were identified using a PubMed search strategy (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi) covering the time period up until November 2005. The following search terms were used in varying combinations: adrenal, adrenocortical, cancer, carcinoma, tumor, diagnosis, imaging, treatment, radiotherapy, mitotane, cytotoxic, surgery.

Evidence synthesis: Tumors typically appear inhomogeneous in both computerized tomography and magnetic resonance imaging with necroses and irregular borders and differ from benign adenomas by their low fat content. Hormonal analysis reveals evidence of steroid hormone secretion by the tumor in the majority of cases, even in seemingly hormonally inactive lesions. Histopathology is crucial for the diagnosis of malignancy and may also provide important prognostic information. In stages I–III open surgery by an expert surgeon aiming at an R0 resection is the treatment of choice. Local recurrence is frequent, particularly after violation of the tumor capsule. Surgery also plays a role in local tumor recurrence and metastatic disease. In patients not amenable to surgery, mitotane (alone or in combination with cytotoxic drugs) remains the treatment of choice. Monitoring of drug levels (therapeutic range 14–20 mg/liter) is mandatory for optimum results. In advanced disease, the most promising therapeutic options (etoposide, doxorubicin, cisplatin plus mitotane, and streptozotocin plus mitotane) are currently being compared in an international phase III trial (www.firm-act.org). Adjuvant treatment options after complete tumor removal (e.g. mitotane, radiotherapy) are urgently needed because postoperative disease-free survival at 5 yr is only around 30%, but options have still not been convincingly established. National registries, international cooperations, and trials provide important new structures for patients but also for researchers aiming at systematic and continuous progress in ACC. However, future advances in the management of ACC will mainly depend on a better understanding of the molecular pathogenesis facilitating the use of modern cancer treatments (e.g. tyrosine kinase inhibitors).
KGF suppresses α2β1 integrin function and promotes differentiation of the transient amplifying population in human prostatic epithelium
Authors: Heer Rakesh , Collins Anne T. , Robson Craig N. , Shenton Brian K. , Leung Hing Y.
Published: March 2006

Prostate epithelial stem cells are self-renewing cells capable of differentiation into prostate epithelium, and are thought to contribute towards both benign and malignant conditions in the human prostate. We have previously demonstrated that prostate epithelial basal cells express high levels of integrin α2β1 and this population can be subdivided into stem (α2β1hi CD133+) and transient-amplifying population (TAP) cells (α2β1hi CD133-). However, the molecular mechanism(s) controlling the commitment and regulation of these cells towards differentiated epithelium remains unclear. Here, we demonstrate that β1 integrin function is required for the maintenance of basal prostatic epithelial cells and suppression of its function by either methylcellulose or, more specifically, β1-blocking antibody (80 μg/ml) induces differentiation, with associated expression of the differentiation-specific markers prostate acid phosphatase (PAP) and cytokeratin 18 (CK18). Keratinocyte growth factor (KGF), a stromal-derived growth factor, has previously been implicated in prostate organogenesis using in vitro tissue recombination experiments. We show that treatment with KGF (10 ng/ml) potently induces epithelial differentiation with concomitant suppression of α2β1 integrin expression as well as the induction of androgen receptor expression. Specifically, p38-MAPK appears to be involved and the presence of SB202190, a p38 inhibitor, significantly blocks KGF-induced differentiation. Furthermore, the expression of the high-affinity receptor tyrosine kinase to KGF (FGFR2) is predominantly detectable in α2β1hi CD133- TAP cells when compared with stem cells (α2β1hi CD133+), which would therefore be relatively unresponsive to the differentiating effect of KGF. Taken together, using a human primary culture model, we have demonstrated key roles for interactions between KGF and integrin-mediated function in the regulation of prostate epithelial differentiation.
A novel function of OLIG2 to suppress human glial tumor cell growth via p27Kip1 transactivation
Authors: Tabu Kouichi , Ohnishi Akiko , Sunden Yuji , Suzuki Tadaki , Tsuda Masumi , Tanaka Shinya , Sakai Toshiyuki , Nagashima Kazuo , Sawa Hirofumi
Published: March 2006

The basic helix-loop-helix transcription factor OLIG2 is specifically expressed in cells of the oligodendrocyte lineage. It is also expressed in various tumors originating from glial cells; however, the expression of OLIG2 is rare or weak in glioblastomas, the most malignant gliomas. The role of OLIG2 in glioma remains unclear. To investigate the function of OLIG2 in glial tumor cells, we have established a glioblastoma cell line, U12-1, in which the expression of OLIG2 is induced by the Tet-off system. Induction of OLIG2 resulted in suppression of both the proliferation and anchorage-independent growth of U12-1. It also resulted in an increase in the expression of p27Kip1. A luciferase assay revealed that the CTF site of the p27Kip1 gene promoter was essential for OLIG2-dependent activation of p27Kip1 gene transcription. Electrophoretic mobility shift assays confirmed that a nuclear extract of OLIG2-expressing U12-1 cells contained a protein complex that binds to the CTF site of the p27Kip1 gene promoter. Furthermore, siRNA against p27Kip1 rescued the OLIG2-mediated growth and DNA synthesis inhibition of U12-1 cells. These results indicate that OLIG2 suppresses the proliferation of U12-1 and that this effect is mediated by transactivation of the p27Kip1 gene, and low expression of OLIG2 may be related to the malignant behavior of human glioblastoma.
The transcription factor B-Myb is essential for S-phase progression and genomic stability in diploid and polyploid megakaryocytes
Authors: García Paloma , Frampton Jon
Published: March 2006

The cell-cycle-regulated Myb-family transcription factor B-Myb is crucial during S phase in many diploid cell types. We have examined the expression and function of B-Myb in megakaryocytic differentiation, during which cells progress from a diploid to a polyploid state. In contrast to terminal differentiation of most haematopoietic cells, during which B-myb is rapidly downregulated, differentiation of megakaryocytes is accompanied by continued B-myb RNA and protein expression. Overexpression of B-Myb in a megakaryoblastic cell line resulted in an increase in the number of cells entering S phase and, upon induction of differentiation, the fraction of cells actively endoreplicating increased. By contrast, reduction of B-Myb levels using short interfering (si)RNA resulted in a decline in S-phase progression during both normal and endoreplicative DNA synthesis. This effect correlated with aberrant localisation of initiation of DNA replication within the nucleus and an increased fraction of cells in mitosis. Chromosomal fragmentation and other aberrations, including shorter, thicker chromatids, end-to-end fusion, and loss of a chromatid, suggest that reduced B-Myb activity is also associated with structural chromosomal instability.
Genetic instability and divergence of clonal populations in colon cancer cells in vitro
Authors: Masramon Laia , Vendrell Elisenda , Tarafa Gemma , Capellà Gabriel , Miró Rosa , Ribas Maria , Peinado Miguel A.
Published: March 2006

The accumulation of multiple chromosomal abnormalities is a characteristic of the majority of colorectal cancers and has been attributed to an underlying chromosomal instability. Genetic instability is considered to have a key role in the generation of genetic and phenotypic heterogeneity in cancer cells. To shed light on the dynamics of chromosomal instability in colon cancer cells, we have analyzed genetic divergence in clonal and subclonal derivates of chromosomally unstable (SW480) and stable (HCT116, LoVo) cell lines. Conventional G-banding karyotyping and arbitrarily primed PCR (AP-PCR) fingerprinting were used to calculate genetic distances among clones and parental cells, and to trace tree-type phylogenies among individual cells and clonal cell populations. SW480 cells showed enhanced karyotypic heterogeneity in clones as compared with parental cells. Moreover, genetic clonal divergence was also increased after two consecutive episodes of single-cell cloning, demonstrating that the homogeneity induced by the bottleneck of cloning is disrupted by genetic instability during clonal expansion and, as a consequence, heterogeneity is restored. These results demonstrate genetic drift in clonal populations originated from isolated cells. The generated cell heterogeneity coupled with selection provides the grounds for the reported feasibility of pre-neoplastic and neoplastic cells to generate new phenotypic variants with increased evolutionary potential.
Cytostatic factor: an activity that puts the cell cycle on hold
Authors: Schmidt Andreas , Rauh Nadine R. , Nigg Erich A. , Mayer Thomas U.
Published: March 2006

Fertilization is the fundamental process in which two gametes - sperm and oocyte - fuse to generate a zygote that will form a new multicellular organism. In most vertebrates, oocytes await fertilization while arrested at metaphase of meiosis II. This resting state can be stable for many hours and depends on a cytoplasmic activity termed cytostatic factor (CSF). Recently, members of the novel Emi/Erp family of proteins have been put forward as important components of CSF. These proteins inhibit the anaphase-promoting complex/cyclosome (APC/C), which acts at the very core of the cell cycle regulatory machinery. Initially, Xenopus early mitotic inhibitor 1 (Emi1) was proposed to be a component of CSF, but newer work suggests that a structural relative, Emi-related protein 1 (Erp1/Emi2), is essential for maintenance of CSF arrest in Xenopus. Most importantly, studies on Erp1/Emi2 regulation have led to a detailed molecular understanding of the Ca2+-mediated release from CSF arrest that occurs upon fertilization.
Identification of multiple cracks using a dynamic mesh-refinement method
Authors: Chen X. F , Zi Y. Y , Li B , He Z. J
Published: March 2006

A dynamic mesh-refinement method (DMRM) of multiple cracks identification is presented, which is based on the relationship of natural frequency change ratios with crack parameters in a beam. The beam is first divided into a coare mesh and the crack is represented by a rotational spring, and expressions relating changes in natural frequencies and the damage index matrix are formulated via an influence matrix. The damage index matrix can be solved by the resulting system of linear algebraic equations. The elements corresponding to the damage indexes with positive values are predicted to contain the crack. Then, these damage elements are refined with the successive subdivision method. The influence matrix is reconstructed through integrating a new subdomain of the damage elements. The new damage index matrix for the refinement meh can focus the crack on the refinement element. In this way, elements are gradually refined until the desired element size is found. The final refinement result indicates the crack location. In each tiny damage element, the spring crack model can be used to quantify the size of the descrete crack. Numerical examples are proposed to demonstrate the effectiveness of the presented method.
Semi-analytical process modelling and simulation of air bending
Authors: Heller B , Kleiner M
Published: March 2006

Mathematical models for a fast semi-analytica simulation of the air bending process of thin as well as of thick sheets have been developed, implemented, and successfully been tested. In contrast to a large number of available approaches in this field that – for reasons of assuming the neutral fibre to coincide with the central fibre and the sheet thickness to remain constant – are limited to thin sheets, in the present work special attention has been paid to the mathematical description of the shift of individual fibres and the changes of thickness. The adequate modelling of these two effects is essential to ensure that the resulting simulation procedure is applicable in the same way to the bending of thin and, in particular, of thick sheets.

The realistic mathematical modelling of the forming process, the accuracy of the results, and the very short computation times permission the simulation system to be used in production-related applications, such as CAPP systems, virtual prototyping environments, and machine control systems, in which commercial finite element analysis software can be utilized either not all or only in a limited way.
Reliability modelling and analysis of automobile engine oil
Authors: Naikan V N A , Kapur S
Published: March 2006

The paper proposes a procedure for reliability analysis of oil used for engine lubrication in wheeled vehicles. Lubricating oil is considered as an important component of an engine system, and topping-up is considered in relation to preventive maintenance actions carried out for oil maintenance. The actual topping-up quantity and the periodicity have been used as data for reliability analysis using parametric and non-parametric techniques. The test procedures use statistical models ‘fitted’ to experimental data. For the case of a multigrade mineral oil, the Weibull distribution is shown to produce superior estimates. This paper also discusses how to use the proposed methodology for decision-making about oil changes and oil performance.
Improving the theoretical cycles of four-stroke internal combustion engines and their simulation calculations
Authors: Qiao A-P , Li Y-Q , Gao F
Published: March 2006

This paper is based on conventional theoretical cycles of reciprocating four-stroke spark ignition (SI) internal combustion engines (ICEs). The authors have analysed the theoretical thermodynamic cyclical processes of modern gasoline direct injection (GDI) engines and then put forward the theory and the method for improving theoretical cycles of ICEs that are different from traditional theoretical cycles. Moreover, theoretical analyses and engine bench tests showed that the theory and the method could be applied not only to improve the cyclical thermal efficiency, power performance, and economic performance of ICEs but also to improve the engine emission characteristics, reduce rough operation, and reduce maximum heat loads, which lowered the maximum working pressure and the maximum working temperature and improved the mean heating temperature. Thus, the working reliability of the engine was improved. The improvement in theoretical cycles is one of the advantages of GDI engines. As is the trend with ICEs, energy conservation, purification, and environmental protection are among the main aspects of GDI engine development.
Improving low load combustion, stability, and emissions in pilot-ignited natural gas engines
Authors: Srinivasan K K , Krishnan S R , Midkiff K C
Published: March 2006

Stringent environmental policies and the ever-increasing demand for energy have triggered interest in novel combustion technologies that use alternative fuels as energy sources. Of these, pilot-ignited natural gas engines that employ small diesel pilots (∼1-5 per cent on an energy basis) to compression ignite a premixed natural gas-air mixture have received considerable attention. This paper discusses the effect of intake charge temperature and pilot injected quantity on the onset of ignition (ΔIGN) and combustion (ΔCOM) in a pilot-ignited natural gas engine with specific focus on early diesel pilot injection [begining of injection (BOI) at about 60° before top dead centre (BTDC)] for low-load operation. Both ΔIGN and ΔCOM had a strong influence on performance and emissions at 60° BTDC. At advanced BOI for both half and quarter-load operation, the best performance and hydrocarbon (HC) emissions could be obtained by optimally advancing ΔIGN relative to TDC and minimizing the cyclic variability in the ΔIGN. Furthermore, a clear dependence of ΔCOM on ΔIGN was observed with the optimally advanced and the least-variable ΔIGN producing the least ΔCOM variations. Engine performance, stability, and emissions were more sensitive to intake charge temperatures in comparison with pilot injected quantities. The best improvement in performance and emissions was obtained with increasing intake temperature at half load, where fuel conversion efficiency (FCE) increased from approximately 31 per cent to 38 per cent, coefficient of variation of indicated mean effective pressure (COVIMEP) decreased from about 11 per cent to 4 per cent, and HC emissions decreased from 72 to 23 g/kW h, while oxides of nitrogen (NOx) emissions increased from 16 to 142 mg/kW h. Performance and emissions trends at quarter load were similar to those observed at half load.
Non-linear statics and dynamics of nanoelectromechanical systems based on nanoplates and nanowires
Authors: Pugno N
Published: March 2006

An analysis of the three-dimensional nanoelectromechanical systems (NEMS) is presented. Nanotubes could be a key one-dimensional element in future NEMS device; but they would be inadequate when two- or three-dimensional structures are required. A general free-energy-based formulation to treat statics and dynamics of three-dimensional NEMS, according to classical or quantum mechanics, is derved and presenteed; the method is then applied to nanoplates and nanowires. The equilibrium and stability of an elastic (e.g., graphene sheet) nanoplate-based NEMS under an electrical field and van der Waals forces (pauli's repulsion and large displacements are also discussed) are evaluated by minimizing the free energy and by the sign of the determinant of its Hessian matrix. The structural instability, arising at ythre so-called pull-in voltage, would correspond to the switch of the device. The amplitude and frequency of the thermal vibrations of the nanoplate are evaluated as a function of the applied voltage. The effect of the van der Waals forces on the NEMS dynamics is also presented. The amplitude and frequency of the oscillations at O K, from the uncertainty principle, are estimated.
A Novel Synthesis of 1,3,5-Triazine Derivative under High Pressure
Authors: Taguchi Yoichi , Yasumoto Masahiko , Tsuchiya Tohru , Oishi Akihiro , Shibuya Isao
Published: March 2006

5,6-Dihydro- 1,3,5-trimethyl-6-methylimino-1,3,5-triazine-2,4-(1H,3H)-dithione (1) was synthesized by the reaction of methyl isothiocyanate under high pressure in the presence of Et3N and H2O. The yield and selectivity of 1 were seriously effected by pressure, reaction temperature, solvent, and the amount of H2O.
Novel Dimerization of 3-(2-Nitroethenyl)guaiazulene. A Convenient Route to Cyclopenta[ef]heptalene
Authors: Kurokawa Shinji
Published: March 2006

Dimerization of 3-(2-nitroethenyl)guaiazulene with sodium methylate gave 5-(1-guaiazulenyl)-5,6-dihydro-9-isopropyl-1-methyl-4-nitrocyclopenta[ef]heptalene (3). On treatment with formic acid, 3 was converted into 9-isopropyl-1-methyl-4-nitrocyclopenta[ef]heptalene quantitatively. A combination of the reactions provides a convenient route to the cyclopenta[ef]heptalene derivatives.
Diastereoselective Synthesis of cis-4,5-Substituted δ-Lactones by the Reaction of 2-Methoxy-2-(trimethylsiloxy)cyclobutanecarboxylic Esters with Carbonyl Compounds
Authors: Shimada Shigeru , Tohno Ichiro , Hashimoto Yukihiko , Saigo Kazuhiko
Published: March 2006

The ring-opening aldol-type reaction of 2-methoxy-2-(trimethylsiloxy)cyclobutanecarboxylic esters with aldehydes smoothly proceeded in the presence of a Lewis acid. Subsequent treatment of the crude products with a catalytic amount of p-TsOH gave cis-4,5-substituted δ-lactones in good yields with high diastereoselectivity. Similar reactions with unsymmetrical ketones also gave δ-lactones in good yields with moderate diastereoselectivity.
Photolysis of p-Phenylenebis(chlorodiazirine), Studied by Matrix Isolation Spectroscopy. Generation, Detection and Characterization of p-Phenylenebis(chloromethylene)
Authors: Tomioka Hideo , Komatsu Kazunori , Nakayama Takehito , Shimizu Masayoshi
Published: March 2006

Photolysis of the title bis-diazirine matrix-isolated in Ar at 10 K monitored by IR and UV/vis spectroscopy indicated that the diazirine underwent stepwise elimination of N2 to produce 3-(4-chlorocarbenophenyl)-3-chlorodiazirine which then eliminated the second N2 to generate para-phenylenebis(chloromethylene). The structure of the bis-carbene was discussed based on the spectroscopic data as well as the semiempirical theoretical calculations.
Synthesis of 2′(3′)-O-Aminoacyl-pdCpA Carrying a Photofunctional Nonnatural Amino Acid
Authors: Niinomi Takaaki , Sisido Masahiko
Published: March 2006

A mixed dinucleotide pdCpA, was synthesized and characterized by spectroscopic as well as enzymic analysis. The dinucleotide was acylated with an N-protected nonnatural amino acid (Boc-azoAla). The acylation was found to occur at the 2′(3′)-O position exclusively.
Photo-response of the [Ru(bpy)3]2+ / BrO3− / H+ System in a Continuous-Flow Stirred Tank Reactor
Authors: Sekiguchi Tetsuo , Mori Yoshihito , Hanazaki Ichiro
Published: March 2006

Effect of photo-irradiation on the autocatalytic oxidation of [Ru(bpy)3]Cl2 by acidic bromate has been investigated in a continuous-flow stirred tank reactor. The photo-induced bifurcation structure and phase diagram have been determined. It is shown that, for a certain range of the bromate concentration, the photo-irradiation can either promote or inhibit the autocatalytic oxidation of [Ru(bpy)3]2+ depending on the irradiation light power.
Single Exponential Decay for the Luminescence Intensity of Ru(bpy)32+ Complex in Langmuir-Blodgett Films
Authors: Kondo Toshihiro , Yanagisawa Masahiro , Fujihira Masamichi
Published: March 2006

The luminescence decay curves of Ru(bpy)32+ in Langmuir-Blodgett (LB) films were often fitted by multiexponential functions whereas those in homogeneous solutions by a single exponential one. Responsible conditions in the LB film preparation for the luminescence decay kinetics were examined. The single exponential decay was observed when the film was prepared in a clean atmosphere and photooxidation of the LB films was avoided.
Synthesis of 4-Aminomethyl-5-ethoxy-3-[(4-vinyl) benzyloxy]pyridine and Its Polymeric Derivatives Planned as Selective Inhibitors of Enzymes
Authors: Bertini Vincenzo , Pocci Marco , Lucchesini Francesco , Munno Angela De , Picci Nevio , Iemma Francesca
Published: March 2006

The synthesis of the new monomer 4-aminomethyl-5-ethoxy-3-[(4-vinyl)benzyloxy]pyridine and its hydrochloride derivative together with their radical homo- and copolymerization to afford the first examples of macromolecular systems planned as selective inhibitors of copper-containing amine oxidases are described.
Multielectron Excitation Structures in X-Ray Absorption Fine Structure Spectra of Bromide Ion in Tetra-n-Propylammonium Salt and Solutions
Authors: Tanida Hajime , Sakane Hideto , Watanabe Iwao , Yokoyama Yu
Published: March 2006

Strong multielectron excitation structures (MEES) in the extended X-ray absorption fine structure (EXAFS) region have been observed in Br K-edge absorption spectra of tetra-n-propylammonium bromide and bromide ion in aqueous and acetonitrile solutions. The MEES were extracted from the background of EXAFS spectra. The positions of steps due to MEES are well predicted by the Z+1 approximation.
Syntheses and Complexing Behavior of New Fluorescent Reagents for Alkaline Earth Metal Ions
Authors: Kakizawa Yusuke , Akita Takahiro , Nakamura Hiroshi
Published: March 2006

A new fluorescent reagent (1) which has two anthracene moieties at both terminals of linear polyether was synthesized, and the complexation behavior of 1 with alkaline earth metal ions was investigated. At the complexation with the metal ions, the fluorescence spectrum of 1 changed from that of monomer to dimer of anthracene. 1 formed both 1 : 1 and 1 : 2 complexes with alkaline earth metal ions, and the complex formation was selective to Ca2+.
Synthesis, Properties, and Reactions of Hexasilyl-3,3′-bicyclopropenyls and Related Compounds
Authors: Sakamoto Kenkichi , Saeki Takuya , Sakurai Hideki
Published: March 2006

Silylation of tetrachlorocyclopropene with trialkylchlorosilanes and magnesium in the presence of HMPA gave hexasilyl-3,3′-bicyclopropenyls or conjugated polymers containing both silylcyclopropene and silylallene moieties. Some reactions of these compounds were described.
A Synthesis of Novel Polyamine Macrocycles with Organosilyl Groups
Authors: Nagasaki Yukio , Honzawa Eiichi , Kato Masao , Kataoka Kazunori , Tsuruta Teiji
Published: March 2006

Polyamine macrocycles having organosilicon moieties were synthesized through new addition reaction of lithium alkylamide toward vinylsilane derivatives. 6-Ethyl-3,3-dimethyl-3-sila-6,9-diazaundecane in the presence of lithium alkylamide took place polyaddition reactions, consisting of diamine and organosilicon units alternatively. By increasing possibilities of intramolecular nucleophilic attack, the 9- and 18-membered polyamine macrocycles with organosilicon moieties were obtained in good yield.