bluuebunny/crossref_metadata_2025 huggingface dataset:
Registry to referral: Using birth defects registries to refer infants and toddlers for early intervention services
Authors: Farel Anita M. , Meyer Robert E. , Hicken Margaret , Edmonds Larry D.
Published: September 2003

BACKGROUND

Although many birth defect surveillance systems were developed for the primary purpose of monitoring trends and conducting epidemiologic studies, a number of programs have recognized the potential of birth defects monitoring systems for identifying and referring children who may be eligible for services. Because almost all surveillance programs maintain a registry of all children who have been diagnosed with birth defects in a particular state or other defined geographic region, registries can play an important role in identifying eligible children and providing timely referral to specialized services.

METHODS

We sent electronically an 18‐question survey to the Centers for Disease Control and Prevention's list of State Birth Defects Surveillance Contacts in all 50 states, the District of Columbia, and Puerto Rico. The survey queried states as to whether they had or were developing a birth defect surveillance program, the extent to which they were currently using or were considering using their program as a means of identifying and referring children for services, and if so, the manner in which referrals were made.

RESULTS

We received completed surveys from all 50 states, Washington, DC, and Puerto Rico. Thirty‐two of the fifty‐two respondents stated that their state or entity has an operational birth defect surveillance program. Of these, 13 have implemented an identification and referral system within the surveillance program. All 16 states that were planning a surveillance program are also are planning or beginning to implement a program that would include an identification and referral system. Respondents cited lack of resources and confidentiality concerns as being the major barriers to implementing a referral system for their registry.

CONCLUSIONS

For many registries, using their surveillance data for program development purposes represents a new undertaking. This trend reflects increasing recognition of the role that state‐based birth defect surveillance systems can play in supporting child‐find efforts for children with special needs. In the long run, this expanded focus may further enhance the public health usefulness of birth defect surveillance programs. Birth Defects Research (Part A) 67:647–650, 2003. Published 2003 Wiley‐Liss, Inc.
Mortality associated with birth defects: Influence of successive disease classification revisions
Authors: Hoyert Donna L.
Published: September 2003

INTRODUCTION

The National Vital Statistics System is the fundamental source of mortality statistics in the United States. The cause‐of‐death classification which is used to assign medical terms to a standard taxonomy is revised periodically, and it is necessary to account for these changes when investigating trends. This paper presents birth defects mortality statistics and preliminary information on the most recent transition between revisions of the classification.

METHODS

Descriptive statistics are presented using multiple cause and underlying cause counts, rankings of leading causes of death, infant mortality rates, and age‐adjusted death rates. Comparability results are based upon records that have been coded using two separate classifications.

RESULTS

Birth defects remain the leading cause of death for infants and among the leading causes for younger age groups. The trend for birth defect mortality shows that the risk of dying from birth defects decreased between 1950 and 2000. The effect of implementing successive revisions of the cause‐of‐death classification was relatively minor until the implementation of the most recent revision. Fewer records are assigned to birth defects in the latest revision than in the previous revision.

DISCUSSION

Researchers investigating mortality trends related to birth defects need to be aware that the cause‐of‐death classification changes periodically. The effect of the changes between two successive classifications can be measured and explained. Birth Defects Research (Part A) 67:651–655, 2003. Published 2003 Wiley‐Liss, Inc.
Mortality throughout early childhood for Michigan children born with congenital anomalies, 1992‐1998
Authors: Berger Katherine H. , Zhu Bao‐Ping , Copeland Glenn
Published: September 2003

BACKGROUND

Congenital anomalies are a leading cause of infant deaths, accounting for almost a fifth of all infant deaths. Few studies have researched the survival experience of infants born with congenital anomalies past the infant stage.

METHODS

Using birth and death files routinely linked to the Michigan Birth Defects Registry, we identified all singleton infants during calendar years 1992 through 1998 with reportable congenital anomalies for our study. A comparative file of children born without congenital anomalies during the same time period was developed using linked birth and death files. The mortality data were assessed by age at death (through age six) and race to determine mortality rates, relative risks, hazard ratios, and survival trends.

RESULTS

Throughout early childhood, children born with congenital anomalies had a high risk of mortality compared with all other children. The overall 7‐year hazard ratio comparing children with congenital anomalies with all other children was 7.2. Overall mortality rates for black children were significantly higher than white children through the age of seven, irrespective of whether they had congenital anomalies. Among children with congenital anomalies, this disparity disappeared after adjusting for birth weight, sex, mother's age, mother's education, and number of organ systems affected.

CONCLUSIONS

Compared with children without congenital anomalies, children born with congenital anomalies had a higher risk of mortality well beyond the infant period. Racial disparities in mortality rates among children with congenital anomalies were due to confounding factors. Birth Defects Research (Part A) 67656–661, 2003. © 2003 Wiley‐Liss, Inc.
First‐year survival of infants born with congenital heart defects in Arkansas (1993‐1998): A survival analysis using registry data
Authors: Cleves Mario A. , Ghaffar Sadia , Zhao Weizhi , Mosley Bridget S. , Hobbs Charlotte A.
Published: September 2003

BACKGROUND

In the United States and other developed nations, birth defects are the leading cause of infant mortality. Congenital heart defects (CHDs) are among the most prevalent and fatal of all birth defects. Here we report the survival probability of infants born with CHDs in Arkansas and examine the impact of multiple malformations on survival.

METHODS

Birth and death certificate records were linked to birth defects registry data for infants born with CHDs from January 1993 through December 1998 in Arkansas. Both neonatal and first‐year survival probabilities were estimated. These were computed non‐parametrically using Kaplan‐Meier's product limit method. A Cox proportional‐hazards model was used to evaluate the relative importance of additional malformations on survival.

RESULTS

A total of 1,983 infants with CHDs were included in this study. The neonatal survival probability for this cohort was 94.0% (95% CI: 93.0%, 95.1%), and the first‐year survival probability was 88.2% (95% CI: 86.8%, 89.6%). The presence of hypoplastic left heart syndrome conferred the greatest reduction in survival, whereas infants with pulmonic valve stenosis and infants with ventricular septal defects had the highest first‐year survival. Infants with multiple CHDs had decreased survival compared to those with isolated heart defects. Survival was also adversely affected by the presence of congenital abnormalities in other body systems.

CONCLUSIONS

Neonatal and first‐year survival of infants with CHDs varies by both the type of cardiac malformation and the presence of additional cardiac and non‐cardiac malformations. Further work will focus on the effects of maternal and infant characteristics on survival. Birth Defects Research (Part A) 67:662–668, 2003. © 2003 Wiley‐Liss, Inc.
Radiative heat flux measurement uncertainty
Authors: Bryant Rodney , Womeldorf Carole , Johnsson Erik , Ohlemiller Thomas
Published: September 2003

As part of an effort to characterize the uncertainties associated with heat flux measurements in a fire environment, an uncertainty analysis example was performed using measurement data from a room corner surface products test that followed the guidelines of ISO 9705. Equations to model the heat transfer at the surface of a Schmidt‐Boelter (thermopile) type total heat flux gauge were selected for use to calculate the incident radiative flux from a total heat flux measurement. The effects of the heat flux measurement uncertainty sources were evaluated by conducting an uncertainty propagation on the resulting equation for incident radiation. For the model equations and the example conditions selected, the free‐stream temperature estimate and the heat flux gauge calibration constant were determined to be major uncertainty contributors. The study demonstrates how to systematically identify major sources of uncertainty for the purpose of reducing total uncertainty and thereby enhancing experiment design. Published in 2003 John Wiley & Sons, Ltd.
Combination of a hydroxy‐functional organophosphorus oligomer and a multifunctional carboxylic acid as a flame retardant finishing system for cotton: Part I. The chemical reactions
Authors: Yang Charles Q. , Wu Weidong
Published: September 2003

Multifunctional carboxylic acids, such as 1,2,3,4‐butanetetracarboxylic acid (BTCA), have been used as crosslinking agents for cotton cellulose to produce wrinkle‐resistant cotton fabrics and garments. Polycarboxylic acids were used to bond hydroxy‐functional organophosphorus oligomer to cotton, thus imparting durable flame retarding properties to the cotton fabric. This research investigated the chemical reactions between the hydroxy‐functional organophosphorus compound and BTCA on cotton. BTCA crosslinks cotton cellulose through the formation of a 5‐membered cyclic anhydride intermediate and esterification of the anhydride with cellulose. In the presence of the organophosphorus compound, BTCA reacts with both the organophosphorus compound and cellulose, thus functioning as a binder between cotton cellulose and the organophosphorus compound and making the flame retarding system durable to laundering. The cotton fabric treated by the combination of the organophosphorus compound and BTCA demonstrated lower wrinkle resistance and less tensile strength loss than that treated by BTCA alone. The phosphorus retention on the cotton fabric after one home laundering cycle was approximately 70%. Copyright © 2003 John Wiley & Sons, Ltd.
Combination of a hydroxy‐functional organophosphorus oligomer and a multifunctional carboxylic acid as a flame retardant finishing system for cotton: Part II. Formation of calcium salt during laundering
Authors: Yang Charles Q. , Wu Weidong
Published: September 2003

Multifunctional carboxylic acids, such as 1,2,3,4‐butanetetracarboxylic acid (BTCA), were used to bond a hydroxy‐functional organophosphorus oligomer (FR) to cotton fabric in the presence of a catalyst, such as sodium hypophosphite (NaH2PO2). Previously, it was found that the cotton fabric treated with FR and BTCA showed a high level of phosphorus retention after one home laundering cycle. However, the flame retardant properties quickly deteriorated as the number of home laundering cycles was increased. In this research, it was found that the free carboxylic acid groups bound to the cotton fabric form an insoluble calcium salt during home laundering, thus diminishing the flame retardant properties of the treated cotton fabric. It was also found that the free carboxylic acid groups on the treated cotton fabric were esterified by triethanolamine (TEA), and that the formation of calcium salt on the fabric was suppressed by the esterification of the free carboxylic acid groups by TEA. The cotton fabric treated with BTCA and the hydroxy‐functional organophosphorus oligomer significantly improved its flame retardance when a new catalyst system consisting of hypophosphorous acid (H3PO2) and TEA was used in the system. Copyright © 2003 John Wiley & Sons, Ltd.
Real time non‐invasive imaging of receptor–ligand interactions in vivo
Authors: Winnard, Paul , Raman Venu
Published: September 2003

Non‐invasive longitudinal detection and evaluation of gene expression in living animals can provide investigators with an understanding of the ontogeny of a gene's biological function(s). Currently, mouse model systems are used to optimize magnetic resonance imaging (MRI), positron emission tomography (PET), single‐photon emission computed tomography (SPECT), and optical imaging modalities to detect gene expression and protein function. These molecular imaging strategies are being developed to assess tumor growth and the tumor microenvironment. In addition, pre‐labeling of progenitor cells can provide invaluable information about the developmental lineage of stem cells both in organogenesis and tumorigenesis. The feasibility of this approach has been extensively tested by targeting of endogenous tumor cell receptors with labeled ligand (or ligand analog) reporters and targeting enzymes with labeled substrate (or substrate analog). We will primarily discuss MRI, PET, and SPECT imaging of cell surface receptors and the feasibility of non‐invasive imaging of gene expression using the tumor microenvironment (e.g., hypoxia) as a conditional regulator of gene expression. © 2003 Wiley‐Liss, Inc.
Cyclin dependent kinase inhibitor p27Kip1 is upregulated by hypoxia via an ARNT dependent pathway
Authors: Wang Gang , Reisdorph Richard , Clark Robert E. , Miskimins Robin , Lindahl Ronald , Miskimins W. Keith
Published: September 2003

Expression of cyclin dependent kinase (Cdk) inhibitor p27Kip1, which blocks cell cycle progression from G1 to S phase, can be regulated via multiple mechanisms including transcription, protein degradation, and translation. Recently, it was shown that p27Kip1 plays an important role in the cellular response to hypoxia. However, the mechanisms involved in the hypoxia‐induced regulation of p27Kip1 expression are still not clear. In this study, we compare the expression of p27Kip1 in two related murine hepatoma cell lines, Hepa‐1 and c4. Hepa‐1 produces functional aryl hydrocarbon receptor nuclear translocator (ARNT). c4 cells are derived from Hepa‐1, but are ARNT deficient. Interestingly, we observed cell line‐dependent effects of hypoxia on the expression of p27Kip1. The level of p27Kip1 protein in Hepa‐1 cells is enhanced by hypoxia, but is reduced by hypoxia in c4 cells. Further investigation demonstrated that hypoxia‐induced, ARNT‐mediated, transactivation of the p27Kip1 gene in Hepa‐1 cells is responsible for the increase in p27Kip1 protein. Once c4 cells were stably transfected with the wild type ARNT gene, a hypoxia‐induced increase in p27Kip1 mRNA was observed and reduction of p27Kip1 protein caused by hypoxia was blocked. Hence, our data indicate that ARNT is involved in transcriptional upregulation of the p27Kip1 gene under hypoxic conditions. © 2003 Wiley‐Liss, Inc.
Imaging gene expression using oligonucleotides and peptide nucleic acids
Authors: Paroo Zain , Corey David R.
Published: September 2003

The development of methods for non‐invasive, real‐time imaging of gene expression would provide powerful tools for biomedical research and medical diagnostics. A broadly applicable strategy for achieving this goal is the use of complementary oligonucleotide probes for recognition of mRNA. The major challenge for molecular imaging is the development of specific and efficient transducers for signaling probe–target interaction. This review summarizes the strengths and limitations of reported molecular approaches for imaging of mRNA expression and discusses the challenges to development of in vivo methods. © 2003 Wiley‐Liss, Inc.
Optical imaging and tumor angiogenesis
Authors: Lin Pengnain Charles
Published: September 2003

Tumor angiogenesis is essential for tumor growth and progression. Therefore, targeting tumor blood vessels is a promising approach for cancer therapy. Angiogenesis, the formation of blood vessels, is a multistep process, and strongly influenced by the microenvironment. There are no in vitro assays that can resemble this dynamic process in vivo. For this reason, animal models and imaging technologies are critical for studying tumor angiogenesis, identifying therapeutic targets as well as validating the targets. Non‐invasive molecular imaging in animal models presents an unprecedented opportunity and ability for us to perform repetitive observations and analysis of the biological processes underlying tumor angiogenesis and tumor progression in living animals in real time. As we gain a better understanding of the fundamental molecular nature of cancer, these techniques will be an important adjunct in translating the knowledge into clinical practice. This important information may elucidate how the tumor blood vessels behave and respond to certain treatments and therapies. © 2003 Wiley‐Liss, Inc.
Tunable, monochromatic X‐rays: An enabling technology for molecular/cellular imaging and therapy
Authors: Carroll Frank
Published: September 2003

Pulsed, tunable, monochromatic X‐rays hold great potential as a cellular and molecular probe. These beams can be tuned to the binding energy of orbital electrons in atoms, making them extremely useful in diagnostic k‐edge imaging and Auger cascade radiotherapy. Their wide tunability makes them ideal for the performance of various techniques as disparate as protein crystallography and three‐dimensional, compressionless, monochromatic mammography. Since only the frequency best suited to the task at hand is used, radiation exposure to patients or animals is exceedingly low when compared to standard X‐ray techniques. © 2003 Wiley‐Liss, Inc.
Combinatorial discovery of tumor targeting peptides using phage display
Authors: Landon Linda A. , Deutscher Susan L.
Published: September 2003

Peptides possess appropriate pharmacokinetic properties to serve as cancer imaging or therapeutic targeting agents. Currently, only a small number of rationally‐derived, labeled peptide analogues that target only a limited subset of antigens are available. Thus, finding new cancer targeting peptides is a central goal in the field of molecular targeting. Novel tumor‐avid peptides can be efficiently identified via affinity selections using complex random peptide libraries containing millions of peptides that are displayed on bacteriophage. In vitro and in situ affinity selections may be used to identify peptides with high affinity for the target antigen in vitro. Unfortunately, it has been found that peptides selected in vitro or in situ may not effectively target tumors in vivo due to poor peptide stability and other problems. To improve in vivo targeting, methodological combinatorial chemistry innovations allow selections to be conducted in the environment of the whole animal. Thus, new targeting peptides with optimal in vivo properties can be selected in vivo in tumor‐bearing animals. In vivo selections have been proven successful in identifying peptides that target the vasculature of specific organs. In addition, in vivo selections have identified peptides that bind specifically to the surface of or are internalized into tumor cells. In the future, direct selection of peptides for cancer imaging may be expedited using genetically engineered bacteriophage libraries that encode peptides with intrinsic radiometal‐chelation or fluorescent sequences. © 2003 Wiley‐Liss, Inc.
Molecular imaging: The latest generation of contrast agents and tissue characterization techniques
Authors: Blankenberg Francis G.
Published: September 2003

Molecular Imaging technologies will have a profound impact on both basic research and clinical imaging in the near future. As the field covers many different specialties and scientific disciplines it is not possible to review all in a single article. In the current article we will turn our attention to those modalities that are either currently in use or in development for the medical imaging clinic. © 2003 Wiley‐Liss, Inc.
Molecular imaging in prostate cancer
Authors: Karam Jose A. , Mason Ralph P. , Koeneman Kenneth S. , Antich Peter P. , Benaim Elie A. , Hsieh Jer‐Tsong
Published: September 2003

Prostate cancer (PCa) is the most common non‐cutaneous malignancy in men. New ways to diagnose this cancer in its early stages are needed. Unique genetic and biochemical changes in the cell pave the way for tumors to grow and metastasize. Novel imaging approaches attempt to detect pathological processes in cancer cells at the molecular level. This has led to the establishment and development of the field of molecular imaging. Positron emission tomography (PET), magnetic resonance spectroscopic imaging (MRSI), magnetic resonance imaging (MRI), and radiolabeled antibodies are a few of the modalities that can detect abnormal tumor metabolic processes in the clinical setting. Other imaging techniques are still in their early phase of development but hold promise for the future, including bioluminescence imaging (BLI), measurement of tumor oxygenation, and measurement of uptake of iodine by tumors. These techniques are non‐invasive and can spare the patient undue morbidity, while potentially providing early diagnosis, accurate follow‐up and, finally, valuable prognostic information. © 2003 Wiley‐Liss, Inc.
Antisense imaging: And miles to go before we sleep?
Authors: Lewis Michael R. , Jia Fang
Published: September 2003

Labeled oligonucleotide analogues for antisense imaging of messenger RNA (mRNA) have great potential for detection of endogenous gene expression in vivo. Successful antisense imaging may be useful for detecting cellular gene expression patterns and early molecular changes in disease. Conclusive demonstration of this technique has been hindered by formidable challenges in surmounting biological barriers and detecting low concentrations of target mRNA. Recent advances in the development of novel antisense molecules, high specific activity radiolabeling chemistry, sophisticated drug targeting technology, and complementary molecular imaging modalities make it quite possible that true antisense imaging will be realized in the near future. © 2003 Wiley‐Liss, Inc.
Functional imaging of angiogenesis in an orthotopic model of pancreatic cancer
Authors: Fleming Jason B. , Brekken Rolf A.
Published: September 2003

Pancreatic cancer is a major unsolved health problem. The estimated overall 5‐year survival rate of only 1–4% is due to aggressiveness of the disease and the lack of effective systemic therapies. Most pancreatic cancer‐related deaths are due to the development of metastases, which represents the culmination of a complex interaction between the host organism and neoplastic cells within the primary tumor. Therefore, the study of tumor–host interaction in the context of the whole organism is necessary to evaluate the pathogenesis of tumor growth and metastasis so that effective therapies can be developed. Recent advances in functional imaging combined with animal models that faithfully recreate the biology of human tumors have elevated our ability to examine these complex interactions. In this review, we will use the example of orthotopic mouse models of pancreatic cancer as a tool to survey the challenges and possibilities of functional imaging of angiogenesis, a critical determinant of metastasis. © 2003 Wiley‐Liss, Inc.
ErbB2 and EGFR are downmodulated during the differentiation of 3T3‐L1 preadipocytes
Authors: Pagano Eleonora , Calvo Juan Carlos
Published: September 2003

The expression of receptors belonging to the epidermal growth factor receptor subfamily has been largely studied these last years in epithelial cells mainly as involved in cell proliferation and malignant progression. Although much work has focused on the role of these growth factor receptors in the differentiation of a variety of tissues, there is little information in regards to normal stromal cells. We investigated erbB2 expression in the murine fibroblast cell line Swiss 3T3L1, which naturally or hormonally induced undergoes adipocyte differentiation. We found that the Swiss 3T3‐L1 fibroblasts express erbB2, in addition to EGFR, and in a quantity comparable to or even greater than the breast cancer cell line T47D. Proliferating cells increased erbB2 and EGFR levels when reaching confluence up to 4‐ and 10‐fold, respectively. This expression showed a significant decrease when growth‐arrested cells were stimulated to differentiate with dexamethasone and isobutyl‐methylxanthine. Differentiated cells presented a decreased expression of both erbB2 and EGFR regardless of whether the cells were hormonally or spontaneously differentiated. EGF stimulation of serum‐starved cells increased erbB2 tyrosine phosphorylation and retarded erbB2 migration in SDS–PAGE, suggesting receptor association and activation. Heregulin‐α1 and ‐β1, two EGF related factors, had no effect on erbB2 or EGFR phosphorylation. Although 3T3‐L1 cells expressed heregulin, its specific receptors, erbB3 and erbB4, were not found. This is the first time in which erbB2 is reported to be expressed in an adipocytic cell line which does not depend on non EGF family growth factors (thyroid hormone, growth hormone, etc.) to accomplish adipose differentiation. Since erbB2 and EGFR expression were downmodulated as differentiation progressed it is conceivable that a mechanism of switching from a mitogenic to a differentiating signaling pathway may be involved, through regulation of the expression of these growth factor receptors. © 2003 Wiley‐Liss, Inc.
Hpr6.6 protein mediates cell death from oxidative damage in MCF‐7 human breast cancer cells
Authors: Hand Randal A. , Craven Rolf J.
Published: September 2003

Reactive oxygen species (ROS) cause cell death and are associated with a variety of maladies, from trauma and infection to organ degeneration and cancer. Cells mount a complex response to oxidative damage that includes signaling from transmembrane receptors and intracellular kinases. We have analyzed the response to oxidative damage in human breast cancer cells expressing the Hpr6.6 (human membrane progesterone receptor) protein. Although Hpr6.6 is related to a putative progesterone‐binding protein, Hpr6.6 is widely expressed in epithelial tissues and shares close homology with a budding yeast damage response protein called Dap1p (damage response protein related to membrane progesterone receptor). We report here that the Hpr6.6 protein regulates the response to oxidative damage in breast cancer cells. Expression of Hpr6.6 in MCF‐7 cells sensitized the cells to death following long‐term/low dose or short‐term/high dose treatment with hydrogen peroxide. Cell death did not occur through a typical apoptotic mechanism and corresponded with hyperphosphorylation of the Akt and IκB proteins. However, inhibition of Akt activation and IκB degradation had no effect on Hpr6.6‐mediated cell death, suggesting that Hpr6.6 regulates cell death through a novel oxidative damage response pathway. Our work indicates a key regulatory function for Hpr6.6 in epithelial tissues exposed to oxidative damage. © 2003 Wiley‐Liss, Inc.
Modification of phospholipids fatty acid composition in reuber H35 hepatoma cells: Effect on HMG‐CoA reductase activity
Authors: García‐Pelayo M. Carmen , García‐Peregrín Eduardo , Martínez‐Cayuela Marina
Published: September 2003

There is controversy about the effect of saturated and polyunsaturated fats on 3‐hydroxy‐3‐methylglutaryl‐CoA (HMG‐CoA) reductase, the main regulatory enzyme of cholesterogenic pathway. Results from dietary studies are difficult to interpret because diets normally contain a mixture of fatty acids. Therefore, we have used Reuber H35 hepatoma cells whose phospholipids were enriched in different individual fatty acids and have studied their effects on the cellular reductase activity. Lauric, myristic, eicosapentaenoic (EPA), and docosahexaenoic (DHA) acids were supplemented to the culture medium coupled to bovine serum albumin. The four fatty acids were incorporated into phospholipids from cells grown in media containing whole serum or lipoprotein‐poor serum (LPPS). Reductase activity of cells cultivated in a medium with LPPS was three to four times higher than those cultivated in medium with whole serum. Saturated fatty acids increased reductase activity of cells grown in medium with whole serum, whereas n‐3 polyunsaturated fatty acids (PUFA) decreased it. However, both saturated and polyunsaturated fatty acids increased reductase activity when serum lipoproteins were removed. In conclusion, this is one of the first reports demonstrating that saturated and n‐3 PUFA only show differential effects on HMG‐CoA reductase activity in the presence of lipoproteins. © 2003 Wiley‐Liss, Inc.
Two alanines juxtaposed to aggrecan's G1 domain alter its intracellular localization
Authors: Oliver Bonnie L. , Cronin Chunxia G. , Bue Catherine , Hand Arthur R. , Tanzer Marvin L.
Published: September 2003

Nascent proteins translated and processed in the endoplasmic reticulum (ER) sometimes contain intrinsic signals for ER retention or ER retrieval. These signals are usually a few amino acids in length, and if alanine modifications are made within these sequences, normal transit patterns of the nascent protein frequently change. The purpose of this study was to determine whether two alanines juxtaposed to the first globular domain of aggrecan's core protein affect its transit in Chinese hamster ovary (CHO) cells. Results show that two alanines juxtaposed to the first globular domain (G1AA) minimized secretion of the protein. However, transgenic proteins with juxtaposed glutamate–phenylalanine (G1EF) or no additional amino acids (G1) were still secreted. GFP‐tagged G1AA localized in the lumen of the ER but not in the Golgi. In contrast, a portion of GFP‐tagged G1EF and G1 did appear in the Golgi compartment. More importantly, unique and striking accumulations of G1EF and G1 transgenic proteins were seen in large dilated regions of the ER cisternae, reminiscent of accumulations seen in α1‐antitrypsin deficiency disease. G1AA transgenic proteins did not form these vesicles but were diffusely distributed throughout the ER lumen. These results indicate that just two juxtaposed alanines can profoundly affect a large globular protein's intracellular localization. © 2003 Wiley‐Liss, Inc.
Overexpression of regucalcin modulates tumor‐related gene expression in cloned rat hepatoma H4‐II‐E cells
Authors: Tsurusaki Yoshinori , Yamaguchi Masayoshi
Published: September 2003

Regucalcin is a regulatory protein in intracellular signaling pathway which is related to various protein kinases and protein phosphatases in many cells. The effect of regucalcin on the expression of tumor‐related genes was investigated in the cloned rat hepatoma H4‐II‐E cells and the hepatoma cells (transfectants) overexpressing regucalcin. Hepatoma cells were cultured for 24–72 h in the presence of fetal bovine serum (FBS; 10%). The proliferation of hepatoma cells was significantly suppressed at 24–72 h of culture in regucalcin transfectants as compared with that of wild‐type or mock‐type cells. Western blot analysis showed that regucalcin was markedly expressed in transfectants. The expression of c‐myc, c‐fos, c‐jun, Ha‐ras, and p53 mRNAs was determined using reverse transcription‐polymerase chain reaction (RT‐PCR). Of these genes, the expression of c‐myc or Ha‐ras mRNAs was significantly suppressed in regucalcin transfectants. The suppression of c‐myc mRNA expression in transfectants was confirmed by using Northern blot analysis; significant suppression was seen at 24, 48, or 72 h of culture in the presence of 10% FBS. Culture with 10% FBS significantly enhanced c‐myc mRNA expression in the hepatoma cells (wild‐type) as compared with that of 1% FBS. The enhancement was significantly abolished in the transfectants. Meanwhile, the expression of p53 mRNA in the hepatoma cells was significantly enhanced in regucalcin‐overexpressing hepatoma cells. This study demonstrates that the expression of oncogene c‐myc and Ha‐ras mRNA in hepatoma cells overexpressing regucalcin is suppressed, and that the tumor suppression gene p53 is enhanced in the transfectants. © 2003 Wiley‐Liss, Inc.
Sodium arsenite downregulates transcriptional activity of AP‐1 and CRE binding proteins in IL‐1β‐treated Caco‐2 cells by increasing the expression of the transcriptional repressor CREMα
Authors: Hershko Dan D. , Robb Bruce W. , Luo Guang‐jo , Hungness Eric S. , Hasselgren Per‐Olof
Published: September 2003

In recent studies, sodium arsenite (SA) inhibited IL‐6 production in cultured intestinal epithelial cells, at least in part by downregulating the activity of nuclear factor‐kappaB (NF‐κB). The influence of SA on the activity of other transcription factors regulating the interleukin‐6 (IL‐6) gene in enterocytes is not known. We tested the effect of SA on the activity of CCAAT/enhancer binding protein (C/EBP), activating protein‐1 (AP‐1), and CRE binding proteins in IL‐1β‐treated Caco‐2 cells. DNA binding activity was determined by electrophoretic mobility shift assay (EMSA) and transcriptional activity by transfecting cells with luciferase reporter plasmids containing promoter constructs with binding sites for the individual transcription factors. DNA binding activity for all three transcription factors was increased after treatment with SA or IL‐1β. In contrast, SA inhibited transcriptional activity of AP‐1 and CRE binding proteins but not C/EBP. Additional experiments provided evidence that the inhibition of AP‐1 and CRE mediated transcriptional activity was associated with, and probably caused by, increased expression of the transcriptional repressor cyclic AMP response element modulator (CREM)α. The present results are consistent with the concept that SA inhibits IL‐6 production in stimulated enterocytes by downregulating the transcriptional activity of several, but not all, IL‐6‐related transcription factors. Because of the multiple important biological functions of IL‐6 in the enterocyte and gut mucosa, methods to regulate enterocyte IL‐6 production have significant clinical implications. © 2003 Wiley‐Liss, Inc.
Analysis of SOX10 mutations identified in Waardenburg‐Hirschsprung patients: Differential effects on target gene regulation
Authors: Chan Kwok Keung , Wong Corinne Kung Yen , Lui Vincent Chi Hang , Tam Paul Kwong Hang , Sham Mai Har
Published: September 2003

SOX10 is a member of the SOX gene family related by homology to the high‐mobility group (HMG) box region of the testis‐determining gene SRY. Mutations of the transcription factor gene SOX10 lead to Waardenburg‐Hirschsprung syndrome (Waardenburg‐Shah syndrome, WS4) in humans. A number of SOX10 mutations have been identified in WS4 patients who suffer from different extents of intestinal aganglionosis, pigmentation, and hearing abnormalities. Some patients also exhibit signs of myelination deficiency in the central and peripheral nervous systems. Although the molecular bases for the wide range of symptoms displayed by the patients are still not clearly understood, a few target genes for SOX10 have been identified. We have analyzed the impact of six different SOX10 mutations on the activation of SOX10 target genes by yeast one‐hybrid and mammalian cell transfection assays. To investigate the transactivation activities of the mutant proteins, three different SOX target binding sites were introduced into luciferase reporter gene constructs and examined in our series of transfection assays: consensus HMG domain protein binding sites; SOX10 binding sites identified in the RET promoter; and Sox10 binding sites identified in the P0 promoter. We found that the same mutation could have different transactivation activities when tested with different target binding sites and in different cell lines. The differential transactivation activities of the SOX10 mutants appeared to correlate with the intestinal and/or neurological symptoms presented in the patients. Among the six mutant SOX10 proteins tested, much reduced transactivation activities were observed when tested on the SOX10 binding sites from the RET promoter. Of the two similar mutations X467K and 1400del12, only the 1400del12 mutant protein exhibited an increase of transactivation through the P0 promoter. While the lack of normal SOX10 mediated activation of RET transcription may lead to intestinal aganglionosis, overexpression of genes coding for structural myelin proteins such as P0 due to mutant SOX10 may explain the dysmyelination phenotype observed in the patients with an additional neurological disorder. © 2003 Wiley‐Liss, Inc.
Profibrillin‐1 maturation by human dermal fibroblasts: Proteolytic processing and molecular chaperones
Authors: Wallis Debra D. , Putnam Elizabeth A. , Cretoiu Jill S. , Carmical Sonya G. , Cao Shi‐Nian , Thomas Gary , Milewicz Dianna M.
Published: September 2003

Fibrillin‐1 is synthesized as a proprotein that undergoes proteolytic processing in the unique C‐terminal domain by a member of the PACE/furin family of endoproteases. This family of endoproteases is active in the trans‐Golgi network (TGN), but metabolic labeling studies have been controversial as to whether profibrillin‐1 is processed intracellularly or after secretion. This report provides evidence that profibrillin‐1 processing is not an intracellular event. Bafilomycin A1 and incubation of dermal fibroblasts at 22°C were used to block secretion in the TGN to confirm that profibrillin‐1 processing did not occur in this compartment. Profibrillin‐1 immunoprecipitation studies revealed that two endoplasmic reticulum‐resident molecular chaperones, BiP and GRP94, interacted with profibrillin‐1. To determine the proprotein convertase responsible for processing profibrillin‐1, a specific inhibitor of furin, α‐1‐antitrypsin, Portland variant, was both expressed in the cells and added to cells exogenously. In both cases, the inhibitor blocked the processing of profibrillin‐1, providing evidence that furin is the enzyme responsible for profibrillin‐1 processing. These studies delineate the secretion and proteolytic processing of profibrillin‐1, and identify the proteins that interact with profibrillin‐1 in the secretory pathway. © 2003 Wiley‐Liss, Inc.
Choline phospholipid metabolism: A target in cancer cells?
Authors: Ackerstaff Ellen , Glunde Kristine , Bhujwalla Zaver M.
Published: September 2003

The experience of treating cancer over the past several decades overwhelmingly demonstrates that the disease continues to evade the vast array of drugs and treatment modalities available in the twenty‐first century. This is not surprising in view of the complexity of this disease, and the multiplicities of pathways available to the cancer cell to enable its survival. Although the progression of cancer arrives at a common end point of cachexia, organ failure, and death, common pathways are rare in cancer. Identifying and targeting common pathways that would act across these levels of multiplicity is essential for the successful treatment of this disease. Over the past decade, one common characteristic consistently revealed by magnetic resonance spectroscopic studies is the elevation of phosphocholine and total choline‐containing compounds in cancer cells and solid tumors. This elevation has been observed in almost every single cancer type studied with NMR spectroscopy and can be used as an endogenous biomarker of cancer. In this article, we have summarized some of the observations on the choline phospholipid metabolism of cancer cells and tumors, and make a case for targeting the aberrant choline phospholipid metabolism of cancer cells. © 2003 Wiley‐Liss, Inc.
Molecular magnetic resonance imaging with targeted contrast agents
Authors: Artemov Dmitri
Published: September 2003

Magnetic resonance imaging (MRI) produces high‐resolution three‐dimensional maps delineating morphological features of the specimen. Differential contrast in soft tissues depends on endogenous differences in water content, relaxation times, and/or diffusion characteristics of the tissue of interest. The specificity of MRI can be further increased by exogenous contrast agents (CA) such as gadolinium chelates, which have been successfully used for imaging of hemodynamic parameters including blood perfusion and vascular permeability. Development of targeted MR CA directed to specific molecular entities could dramatically expand the range of MR applications by combining the noninvasiveness and high spatial resolution of MRI with specific localization of molecular targets. However, due to the intrinsically low sensitivity of MRI (in comparison with nuclear imaging), high local concentrations of the CA at the target site are required to generate detectable MR contrast. To meet these requirements, the MR targeted CA should recognize targeted cells with high affinity and specificity. They should also be characterized by high relaxivity, which for a wide variety of CA depends on the number of contrast‐generating groups per single molecule of the agent. We will review different designs and applications of targeted MR CA and will discuss feasibility of these approaches for in vivo MRI. © 2003 Wiley‐Liss, Inc.
Identification of γA‐like protocadherin expressed during chick development
Authors: Capehart Anthony A. , Kern Christine B.
Published: September 2003

The protocadherins are calcium‐dependent cell adhesion molecules of the cadherin superfamily that have been described in numerous species. Although less well characterized than classical cadherins, the protocadherins are also thought to facilitate critical cell–cell interactions during embryonic development. We have cloned a novel protocadherin from the embryonic chick utilizing a monoclonal antibody produced against a peanut agglutinin‐binding fraction of cultured chick limb tissue to screen a λZAP cDNA expression library from the stage 25 limb. A 2.8 kb cDNA clone was obtained that encoded multiple cadherin‐like ectodomains. Northern blotting revealed a single 4.6 kb RNA transcript that was highly enriched in the stage 43 chick brain. Utilization of 3′ Rapid amplification of cDNA ends (RACE) identified the entire 2.4 kb reading frame. The chick protocadherin contained five cadherin‐like extracellular repeats and a highly conserved cytoplasmic domain. Amino acid alignment of the extracellular domains revealed marked identity to the human γA protocadherin subfamily. In situ hybridization showed low levels of mRNA localization in several developing chick tissues, but stronger expression in the neural tube and dorsal root ganglia at stage 27. In the stage 43 chick brain, protocadherin mRNA was noted in discrete regions, particularly within the developing optic lobe. As for protocadherins described in other species, these results suggest that this novel γA‐like protocadherin may also play a role in chick neural development. © 2003 Wiley‐Liss, Inc.
A brief introduction to cell‐penetrating peptides
Authors: Lundberg Pontus , Langel Ülo
Published: September 2003

Cell membranes act as protective walls to exclude most molecules that are not actively imported by living cells. This is an efficient way for a cell to prevent uncontrolled influx or efflux of solutes, which otherwise would be harmful to it. Only compounds within a narrow range of molecular size, polarity and net charge are able to diffuse effectively through cell membranes. In order to overcome this barrier for effective delivery of membrane‐impermeable molecules, several chemical and physical methods have been developed. These methods, e.g. electroporation, and more recent methods as cationic lipids/liposomes, have been shown to be effective for delivering hydrophobic macromolecules. The drawbacks of these harsh methods are, primarily, the unwanted cellular effects exerted by them, and, secondly, their limitation to in vitro applications. The last decade's discovery of cell‐penetrating peptides translocating themselves across cell membranes of various cell lines, along with a cargo 100‐fold their own size, via a seemingly energy‐independent process, opens up the possibility for efficient delivery of DNA, antisense peptide nucleic acids, oligonucleotides, proteins and small molecules into cells both in vitro and in vivo. Copyright © 2003 John Wiley & Sons, Ltd.
Lipid vector for the delivery of peptides towards intracellular pharmacological targets
Authors: Gras‐Masse Hélène
Published: September 2003

The ability of single‐chain lipopeptides to gain access to cellular compartments other than those related to degradation/recycling was first deduced from their capacity to deliver peptide antigens into MHC‐class I loading mechanisms. The ability of lipopeptides to escape complete endosome degradation was further illustrated by the selective inhibition of different protein kinase C isoenzymes and, more recently, the presentation of agonistic activity towards the interferon gamma receptor. Taken together, several independent results indicate that modification of a peptide by a single lipid chain confers upon it intracellular trafficking properties that can be used to deliver functional cargo peptides into living cells; the endoplasmic reticulum, cytosolic protease activity, sites of kinase activity, or even the signalling pathway associated with cytokine stimulation, all appear accessible to peptide modified by a single lipidic moiety. In this context, the interferon gamma receptor can be considered as a very discriminative pharmacological model, useful for the comparative evaluation of the cellular delivery of lipopeptides, as it allows the unambiguous tracking of their intact delivery into a wide range of cellular compartments. This model is now being used to probe the influence of the nature of the lipid moiety on the trafficking properties of lipopeptides. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis and application of functional peptides as cell nucleus‐directed molecules in the treatment of malignant diseases
Authors: Pipkorn R. , Waldeck W. , Braun K.
Published: September 2003

The unique functions of biomolecules, including transport accross biological membranes (e.g. the cell membrane, the nuclear envelope), modulation of protein function, gene transcription, reconstitution of the malignant transformation, and viral, bacterial and fungal activities underlie a high pharmaceutical potential. The development of combinatorial functional peptide modules in this important area has been slow, in contrast to the rapid development in the synthesis of small biopolymers. The conjugation of a short transmembrane transport peptide module with a cell nucleus address peptide module and with any substance is attractive for preparation of BioShuttle‐based peptides because of the well‐established automated synthesis of peptides. Variation of the different functional modules for drug targeting and the choice of substances can be combined to create novel bioconjugates with unique properties. This article provides an overview of previous work on the BioShuttle technology and outlines the promising use of this approach in combinatorial peptide synthesis and drug discovery. Copyright © 2003 John Wiley & Sons, Ltd.