bluuebunny/crossref_metadata_2025_split huggingface dataset:
Merkel cell carcinoma
Authors: Koljonen Virve 
Published: February 2006

AbstractBackgroundMerkel cell carcinoma (MCC) is an unusual primary neuroendocrine carcinoma of the skin. MCC is a fatal disease, and patients have a poor chance of survival. Moreover, MCC lacks distinguishing clinical features, and thus by the time the diagnosis is made, the tumour usually have metastasized. MCC mainly affects sun-exposed areas of elderly persons. Half of the tumours are located in the head and neck region.MethodsMCC was first described in 1972. Since then, most of the cases reported, have been in small series of patients. Most of the reports concern single cases or epidemiological studies. The present study reviews the world literature on MCC. The purpose of this article is to shed light on this unknown neuroendocrine carcinoma and provide the latest information on prognostic markers and treatment options.ResultsThe epidemiological studies have revealed that large tumour size, male sex, truncal site, nodal/distant disease at presentation, and duration of disease before presentation, are poor prognostic factors. The recommended initial treatment is extensive local excision. Adjuvant radiation therapy has recently been shown to improve survival. Thus far, no chemotherapy protocol have achieved the same objective.ConclusionAlthough rare, the fatality of this malignancy makes is important to understand the etiology and pathophysiology. During the last few years, the research on MCC has produced prognostic markers, which can be translated into clinical patient care.
Expression of early transcription factors Oct-4, Sox-2 and Nanog by porcine umbilical cord (PUC) matrix cells
Authors: Carlin Ryan , Davis Duane , Weiss Mark , Schultz Bruce , Troyer Deryl 
Published: February 2006

Abstract

Background
Three transcription factors that are expressed at high levels in embryonic stem cells (ESCs) are Nanog, Oct-4 and Sox-2. These transcription factors regulate the expression of other genes during development and are found at high levels in the pluripotent cells of the inner cell mass. The downregulation of these three transcription factors correlates with the loss of pluripotency and self-renewal, and the beginning of subsequent differentiation steps. The roles of Nanog, Oct-4 and Sox-2 have not been fully elucidated. They are important in embryonic development and maintenance of pluripotency in ESCs. We studied the expression of these transcription factors in porcine umbilical cord (PUC) matrix cells.

Methods
Cells were isolated from Wharton's jelly of porcine umbilical cords (PUC) and histochemically assayed for the presence of alkaline phosphatase and the presence of Nanog, Oct-4 and Sox-2 mRNA and protein. PCR amplicons were sequenced and compared with known sequences. The synthesis of Oct-4 and Nanog protein was analyzed using immunocytochemistry. FACS analysis was utilized to evaluate Hoechst 33342 dye-stained cells.

Results
PUC isolates were maintained in culture and formed colonies that express alkaline phosphatase. FACS analysis revealed a side population of Hoechst dye-excluding cells, the Hoechst exclusion was verapamil sensitive. Quantitative and non-quantitative RT-PCR reactions revealed expression of Nanog, Oct-4 and Sox-2 in day 15 embryonic discs, PUC cell isolates and porcine fibroblasts. Immunocytochemical analysis detected Nanog immunoreactivity in PUC cell nuclei, and faint labeling in fibroblasts. Oct-4 immunoreactivity was detected in the nuclei of some PUC cells, but not in fibroblasts.

Conclusion
Cells isolated from PUC express three transcription factors found in pluripotent stem cell markers both at the mRNA and protein level. The presence of these transcription factors, along with the other characteristics of PUC cells such as their colony-forming ability, Hoechst dye-excluding side population and alkaline phosphatase expression, suggests that PUC cells have properties of primitive pluripotent stem cells. Furthermore, PUC cells are an easily and inexpensively obtained source of stem cells that are not hampered by the ethical or legal issues associated with ESCs. In addition, these cells can be cryogenically stored and expanded.
Antimicrobial resistance of Escherichia coliisolates from broiler chickens and humans
Authors: Miles Tricia D , McLaughlin Wayne , Brown Paul D 
Published: February 2006

Abstract

Background
Antimicrobial usage is considered the most important factor promoting the emergence, selection and dissemination of antimicrobial-resistant microorganisms in both veterinary and human medicine. The aim of this study was to investigate the prevalence and genetic basis of tetracycline resistance in faecal Escherichia coli isolates from healthy broiler chickens and compare these data with isolates obtained from hospitalized patients in Jamaica.

Results
Eighty-two E. coli strains isolated from faecal samples of broiler chickens and urine and wound specimens of hospitalized patients were analyzed by agar disc diffusion to determine their susceptibility patterns to 11 antimicrobial agents. Tetracycline resistance determinants were investigated by plasmid profiling, transformations, and amplification of plasmid-borne resistance genes. Tetracycline resistance occurred at a frequency of 82.4% in avian isolates compared to 43.8% in human isolates. In addition, among avian isolates there was a trend towards higher resistance frequencies to kanamycin and nalidixic acid (p < 0.05), while a greater percentage of human isolates were resistant to chloramphenicol and gentamicin (p < 0.05). Multiple drug resistance was found in isolates from both sources and was usually associated with tetracycline resistance. Tetracycline-resistant isolates from both avian and human sources contained one or several plasmids, which were transmissible by transformation of chemically-competent E. coli. Tetracycline resistance was mediated by efflux genes tetB and/or tetD.

Conclusion
The present study highlights the prevalence of multiple drug resistant E. coli among healthy broiler chickens in Jamaica, possibly associated with expression of tetracycline resistance. While there did not appear to be a common source for multiple drug resistance in the strains from avian or human origin, the genes encoding resistance are similar. These results suggest that genes are disseminated in the environment and warrant further investigation of the possibility for avian sources acting as reservoirs for tetracycline resistance.
Gastric Inhibitory Polypeptide as an Endogenous Factor Promoting New Bone Formation after Food Ingestion
Authors: Tsukiyama Katsushi , Yamada Yuichiro , Yamada Chizumi , Harada Norio , Kawasaki Yukiko , Ogura Masahito , Bessho Kazuhisa , Li Minqi , Amizuka Norio , Sato Masahiro , Udagawa Nobuyuki , Takahashi Naoyuki , Tanaka Kiyoshi , Oiso Yutaka , Seino Yutaka 
Published: February 2006

Abstract
Calcium plays a fundamental role as second messenger in intracellular signaling and bone serves as the body’s calcium reserve to tightly maintain blood calcium levels. Calcium in ingested meal is the main supply and inadequate calcium intake causes osteoporosis and bone fracture. Here, we describe a novel mechanism of how ingested calcium is deposited on bone. Meal ingestion elicits secretion of the gut hormone gastric inhibitory polypeptide (GIP) from endocrine K cells in the duodenum. Bone histomorphometrical analyses revealed that bone formation parameters in the mice lacking GIP receptor (GIPR−/−) were significantly lower than those of wild-type (GIPR+/+) mice, and that the number of osteoclasts, especially multinuclear osteoclasts, was significantly increased in GIPR−/− mice, indicating that GIPR−/− mice have high-turnover osteoporosis. In vitro examination showed the percentage of osteoblastic cells undergoing apoptosis to be significantly decreased in the presence of GIP. Because GIPR−/− mice exhibited an increased plasma calcium concentration after meal ingestion, GIP directly links calcium contained in meal to calcium deposition on bone.
Sex-Dependent Liver Gene Expression Is Extensive and Largely Dependent upon Signal Transducer and Activator of Transcription 5b (STAT5b): STAT5b-Dependent Activation of Male Genes and Repression of Female Genes Revealed by Microarray Analysis
Authors: Clodfelter Karl H. , Holloway Minita G. , Hodor Paul , Park Soo-Hee , Ray William J. , Waxman David J. 
Published: February 2006

AbstractSexual dimorphism in mammalian liver contributes to sex differences in physiology, homeostasis, and steroid and foreign compound metabolism. Many sex-dependent liver genes are regulated by sex differences in pituitary GH secretion, with the transcription factor, signal transducer and activator of transcription (STAT5b), proposed to mediate signaling by the pulsatile, male plasma GH profile. Presently, a large-scale gene expression study was conducted using male and female mice, wild type and Stat5b inactivated, to characterize sex differences in liver gene expression and their dependence on STAT5b. The relative abundance of individual liver RNAs was determined for each sex-genotype combination by competitive hybridization to 23,574-feature oligonucleotide microarrays. Significant sex differences in hepatic expression were seen for 1603 mouse genes. Of 850 genes showing higher expression in males, 767 (90%) were down-regulated in STAT5b-deficient males. Moreover, of 753 genes showing female-predominant expression, 461 (61%) were up-regulated in STAT5b-deficient males. In contrast, approximately 90% of the sex-dependent genes were unaffected by STAT5b deficiency in females. Thus: 1) STAT5b is essential for sex-dependent liver gene expression, a characteristic of approximately 1600 mouse genes (4% of the genome); 2) male-predominant liver gene expression requires STAT5b, or STAT5b-dependent factors, which act in a positive manner; and 3) many female-predominant liver genes are repressed in males in a STAT5b-dependent manner. Several of the STAT5b-dependent male genes encode transcriptional repressors; these may include direct STAT5b targets that repress female-predominant genes in male liver. Several female-predominant repressors are elevated in STAT5b-deficient males; these may contribute to the major loss of male gene expression seen in the absence of STAT5b.
Bioinspired Electron-Transfer Systems and Applications
Authors: Fukuzumi Shunichi 
Published: February 2006

Abstract
Bioinspired electron-transfer systems including artificial photosynthesis and respiration are presented herein together with some of their applications. First, multi-step electron-transfer systems composed of electron donor–acceptor ensembles have been developed, mimicking functions of the photosynthetic reaction center. However, a significant amount of energy is lost during the multi-step electron-transfer processes. Then, as an alternative to conventional charge-separation functional molecular models based on multi-step long-range electron transfer within redox cascades, simple donor–acceptor dyads have been developed to attain a long-lived and high energy charge-separated state without significant loss of excitation energy, by fine control of the redox potentials and of the geometry of donor–acceptor dyads that have small reorganization energies of electron transfer. Such simple molecular dyads, capable of fast charge separation but extremely slow charge recombination, have significant advantages with regard to synthetic feasibility, providing a variety of applications including construction of organic solar cells and development of efficient photocatalytic systems for the solar energy conversion. An efficient four-electron reduction of dioxygen to water by one-electron reductants such as ferrocene derivatives as well as by an NADH analog has also been achieved as a respiration model by using a cofacial dicobalt porphyrin that can form the μ-peroxo Co(III)–O2–Co(III) complex. The catalytic mechanism of the four-electron reduction of dioxygen has been clarified based on the detailed kinetic study and the detection of the intermediate.
Theoretical Investigations of the Electronic and Nuclear Dynamics of Molecules in Intense Laser Fields: Quantum Mechanical Wave Packet Approaches
Authors: Kono Hirohiko , Sato Yukio , Kanno Manabu , Nakai Katsunori , Kato Tsuyoshi 
Published: February 2006

Abstract
We have developed a method for describing the reaction dynamics of a polyatomic molecule in intense laser fields. First, the dynamical behavior of H2+ and H2 in near-infrared, intense laser fields (I &gt; 1013 W cm−2 and λ &gt; 700 nm) was examined; accurate evaluation of the electronic and nuclear wave packet was achieved by the dual transformation method that we developed. Using “field-following” time-dependent adiabatic states defined as eigenfunctions of the “instantaneous” electronic Hamiltonian, we have clarified the dynamics of bound electrons, ionization processes, Coulomb explosion processes, and molecular vibrations of H2+ and H2. The analyses indicate that the multielectron dynamics and nuclear dynamics of polyatomic molecules in intense fields can be described by using the potential surfaces of time-dependent adiabatic states and the nonadiabatic coupling elements between those states. To obtain time-dependent adiabatic states of a molecule, one can diagonalize the electronic Hamiltonian including the interaction with the instantaneous laser electric field by ab initio molecular orbital (MO) methods. The time-dependent adiabatic potentials obtained are used to evaluate the multichannel nuclear dynamics until the next ionization process. We have applied the time-dependent adiabatic state approach to reveal the characteristic features of the dynamics of structural deformations of CO2 and its cations in a near-infrared intense laser field. The experimentally observed stretched and bent structure of CO23+ just before Coulomb explosions originates from the structural deformation of CO22+. We also revealed the mechanism of the experimentally observed bond dissociation of C2H5OH; we found that the relative probability of C–O bond cleavage to that of C–C bond cleavage becomes smaller with decreases in the pulse length. This example clearly shows that field-induced nonadiabatic transitions play a decisive role in the reaction dynamics of molecules in an intense laser field.
Structure of Highly Concentrated Aqueous Lithium Alaninate Solutions Studied by Neutron Diffraction with 14N/15N, 6Li/7Li, and H/D Isotopic Substitution Methods
Authors: Kameda Yasuo , Sasaki Motoya , Amo Yuko , Usuki Takeshi 
Published: February 2006

Abstract
Neutron diffraction measurements have been carried out at 25 °C for aqueous 18 mol % lithium alaninate heavy water solutions, [C*H3C*H(*ND2)COO*Li]0.18(D2O)0.82, in which the isotopic compositions 14N/15N, HM/DM (HM: methyl-hydrogen atom), and HM′/DM′ (HM′: methine-hydrogen atom) within the alaninate ion, and 6Li/7Li for the lithium ion were changed. The hydration structures of both alaninate and lithium ions were derived from the least squares fitting analysis of observed first-order difference functions, ΔN(Q), ΔHM(Q), ΔHM′(Q), and ΔLi(Q). It was revealed that the amino group of the alaninate ion forms a hydrogen bond of the N···Dw1–OwDw2 type (Ow and Dw denote water–oxygen and water–deuterium atoms, respectively) with ca. one D2O molecule (rNDw1 = 2.00(1) Å, ∠N···Dw1–Ow = 165(10)°), and simultaneously forms hydrogen bonds of the N···OD2 type with 1.4(1) D2O molecules (rNO = 2.95(5) Å, rND = 3.35(5) Å). The numbers of water molecules neighboring hydrogen atoms within the methyl- and methine-group of the alaninate ion were determined to be 0.62(1) and 0.86(9), respectively. The first coordination shell of Li+ was found to consist of 2.42(5) D2O molecules and 2.3(2) alaninate ions. The bond angle ∠Li+···Oc–C (Oc: carboxyl-oxygen atom) and the dihedral angle between the plane involving atoms Li+···Oc–C and the plane of the carboxyl group of the alaninate ion were determined to be 101(1) and 74(1)°, respectively.
Peroxodiiron Complexes of Polypyridine Ligands: Syntheses, Physicochemical Properties, and Thermal Stability Markedly Enhanced by Hexapyridine Dinucleating Ligand
Authors: Kodera Masahito , Itoh Motoharu , Kano Koji , Funabiki Takuzo 
Published: February 2006

Abstract
The peroxodiiron(III) complexes [Fe2(O)(O2)(OAc)(hexpy)](CF3SO3) (2) and [Fe2(O)(O2)(OAc)(tripy)2](ClO4) (4) (hexpy = 1,2-di[6-bis(2-pyridyl)methyl-2-pyridyl]ethane and tripy = 2-di(2-pyridyl)methyl-6-methylpyridine) were prepared by addition of H2O2 to the di(μ-acetato)-μ-oxodiiron(III) complexes [Fe2(O)(OAc)2(hexpy)](CF3SO3)2 (1c) and [Fe2(O)(OAc)2(tripy)2](ClO4)2 (3) in MeCN, respectively. The peroxo complex 2 was isolated as a purple solid, but 4 could not be due to its instability. Detailed spectral studies of 2 and 4 revealed the unique triply bridged μ-acetato-μ-oxo-μ-1,2-peroxodiiron(III) core structures. The spontaneous decomposition of 2 and 4 in various solvent systems was kinetically investigated. The half-life of 2 and 4 in dry MeCN was 8.7 h at 300 K and 10 min at 263 K, respectively, clearly showing that the thermal stability of 2 is markedly enhanced by the hexpy ligand.
Characterization by Simultaneous X-ray Diffractometry and Differential Scanning Calorimetry of the Exothermic Change of Dimethyl-β-cyclodextrin Prepared by Drying after Solvent Dissolution
Authors: Kohata Susumu , Hamabe Yuko , Jyodoi Kouki , Kurihara Masahiko , Kubo Tomikatsu 
Published: February 2006

Abstract
Heptakis(2,6-di-O-methyl)-β-cyclodextrin (DM-β-CD), prepared by dissolution in either pure water or acetone and dried at 40 °C, showed a characteristic exothermic change in the range 160–185 °C. Simultaneous X-ray diffractometry and differential scanning calorimetry (XRD-DSC) clearly showed the transition of DM-β-CD from an amorphous to a crystalline state during exothermic reactions.
Hydrolysis of Phosphoric Acid Ester across an Enzyme Membrane: Potato Acid Phosphatase Immobilized on a Na–Perfluorocarboxylate Ionomer Membrane for Recovery of Reaction Product
Authors: Nomura Kazuo , Liu Mo 
Published: February 2006

Abstract
Acid phosphatase from potato was immobilized onto the surface of the external solution side of a perfluorocarboxylate ionomer membrane using a cross-linking reagent. Based on the distinct difference in membrane permeabilities to 4-nitrophenol and 4-nitrophenyl phosphate, a membrane reactor system using the immobilized enzyme has been designed for the recovery of the reaction product of enzymatic hydrolysis. To observe the recovery rate for the hydrolysis product, the flux from the external solution side to the internal solution side crossing the membrane was measured in the substrate concentration range below 1 × 10−2 mol dm−3. The recovery rate was found to obey a Michaelis–Menten type equation. The Michaelis constant for the immobilized enzyme was smaller than that for the free enzyme obtained from the kinetic properties in the bulk solution. The optimum pH value for the immobilized enzyme membrane was investigated.
Strong Chemical Structure Dependence for Individual Dissolution of Single-Walled Carbon Nanotubes in Aqueous Micelles of Biosurfactants
Authors: Ishibashi Ayumi , Nakashima Naotoshi 
Published: February 2006

Abstract
We report a strong chemical structure dependence for the individual dissolution of single-walled carbon nanotubes (SWNTs) in aqueous micelles of six steroid biosurfactants including sodium cholate (SC), sodium deoxycholate (SDC), sodium taurodeoxycholate (STDC), sodium glycocholate (SGC), 3-[(3-cholamidopropyl)dimethylammonio]propane-1-sulfonic acid (CHAPS), and sucrose monocholate (SMC) and two sugar surfactants, n-octyl β-d-glucoside (OG) and n-decyl β-d-maltoside (DM).
The uptake of HIV testing among patients with chlamydial or gonococcal infections attending a genitourinary medicine clinic
Authors: Manavi K , McMillan A 
Published: February 2006

Bacterial sexually transmitted infections (STIs) may be markers of high-risk sexual activity. Counselling for these infections provides an opportunity for promoting HIV testing. The aim of the present study was to compare the uptake of HIV testing between patients with gonorrhoea or chlamydial infections and those without a bacterial STI. A study on patients screened for chlamydial or gonococcal infections in the Department of Genitourinary (GU) Medicine, Edinburgh between 1 July 2002 and 30 June 2003. The overall uptake of HIV testing among patients screened for chlamydial and gonococcal infections was 2263 (37%) of 6184 and 2012 (44%) of 4583, respectively ( P < 0.0002). Uptake of HIV testing was significantly higher among uninfected patients: for chlamydial infection, 17% of 1857 infected patients versus 45% of 4327 uninfected patients ( P < 0.0002); and for gonococcal infection, 24% of 256 infected patients versus 45% of 4327 uninfected patients ( P < 0.0002). The policy of pre-test counselling needs to be redesigned in order to improve the uptake of HIV testing among patients with high-risk sexual activity.
Will sexual risk behaviour increase after being vaccinated for AIDS?
Authors: Crosby Richard A , Holtgrave David R 
Published: February 2006

The question of whether people will engage in greater levels of HIV-associated risk behaviour after receiving an AIDS vaccine has not been sufficiently investigated. Three objectives were: (1) assess the likelihood that people will engage in greater levels of HIV-risk behaviour after receiving an AIDS vaccine; (2) determine the association of increases with vaccination intent; and (3) identify differences between people who would and would not increase their HIV-risk behaviour after vaccination. A cross-sectional survey was conducted of 278 adults from three populations: gay men, African-American women, and persons who used illicit drugs. Nearly one-quarter of the sample indicated a likelihood that their HIV-risk behaviour would increase after vaccination. This increase was positively associated ( r = 0.24) with increased intent to be vaccinated. Previous worry about having HIV (adjusted odds ratio [AOR] = 3.4, P = 0.004), being 32 years of age or older (AOR = 2.9, P = 0.0007), and having less than a high school education (AOR = 2.3, P = 0.027) were each associated with a post-vaccination increase in HIV risk. With the seemingly real potential for increased HIV-risk behaviours after being vaccinated against AIDS, intervention studies are warranted to identify strategies with potential to minimize this phenomenon.
Providing written information on HIV testing improves patient knowledge but does not affect test uptake
Authors: Ivens D , Sabin C 
Published: February 2006

The objective of this study is to determine the effect of providing written information about HIV testing on patient knowledge and test uptake. Patients attending our genitourinary medicine clinic in July 2003 were offered written information about HIV and the test. They were asked to complete a questionnaire which elicited knowledge provided on the leaflet. A control group of individuals were offered verbal discussion only. A total of 382 questionnaires were completed. Individuals given written information were more likely to believe that HIV could not be transmitted by insect bites ( P = 0.01), more aware of current treatments and that a negative test would not affect a future mortgage application ( P = 0.001). There was no difference in test uptake or reasons for declining a test in both groups. Providing written information on HIV testing increases patient knowledge, but does not affect test uptake.