bluuebunny/crossref_metadata_2025 huggingface dataset:
Influenza and Emergency Department Utilization by Elders
Authors: Schull Michael J. , Mamdani Muhammad M. , Fang Jiming
Published: April 2005

Objectives: Influenza outbreaks have been associated with worsened emergency department (ED) crowding. We sought to examine the mechanism behind this association. Methods: A retrospective time series analysis was conducted in Toronto from January 1996 to April 1999. Weekly data on laboratory‐confirmed influenza and other respiratory virus cases in the community and visits to all city EDs (n= 20) were obtained. In longitudinal analyses, we determined the association between influenza and changes in ED utilization by younger and older patients with specific diagnoses grouped as major influenza related (MIR) and upper respiratory infection (URI). Time trends in psychiatric visits and their relationship to influenza were used as a control group. Results: A mean of 11,075 ED visits occurred weekly (SD = 698; average age, 39.9 years; 51% women). Four influenza seasons occurred, with weekly incident case counts ranging from 0 to 236; there were a total of 81 weeks with zero new cases between seasons. In multivariable analyses, every ten new cases of influenza active in the community was associated with a 1.5% (95% confidence interval = 1.2 to 1.8) and 1.2% (95% confidence interval = 0.6 to 1.8) absolute increase in the proportion of ED patients who were elders with MIR conditions and URIs, respectively. Influenza was not significantly associated with ED utilization by younger patients; other respiratory viruses were not significantly associated with ED utilization for any patient group. Conclusions: Influenza season is associated with increased ED utilization by patients aged 65 years and older, most of whom have major respiratory illnesses and may require hospital admission. No association was seen between influenza and utilization by younger patients. Efforts to reduce the impact of influenza seasons on EDs should focus on elders.
Accuracy and Test Characteristics of Ancillary Tests of Cerebrospinal Fluid for Predicting Acute Bacterial Meningitis in Children with Low White Blood Cell Counts in Cerebrospinal Fluid
Authors: Bonsu Bema K. , Harper Marvin B.
Published: April 2005

Objectives: To determine whether ancillary tests of cerebrospinal fluid (CSF), specifically, the total protein concentration, glucose concentration, and percent neutrophils, provide information for diagnosing acute bacterial meningitis among children with low white blood cell (WBC) count in CSF. Methods: The authors retrospectively reviewed CSF from children aged 1 month to 18 years undergoing lumbar puncture at Children's Hospital in Boston from 1993 to 1999. Data were supplemented with CSF test results obtained from children with 0–30 WBCs/mm3 in CSF diagnosed with acute bacterial meningitis at the same institution from 1984 to 1992. For each test, the incremental value of ancillary tests was estimated by calculating indices of performance such as the area under receiver operator characteristic curves (AUC) and interval likelihood ratios that are relatively insensitive to disease prevalence. Results: Among children with 0–30 WBCs/mm3 in CSF who met study criteria, acute bacterial meningitis was identified in ten of 7,701 (0.1%) for the period from 1993 to 1999 and supplemented with 11 additional cases for the period from 1984 to 1992. AUC values for ancillary tests were 0.61 for total protein concentration, 0.69 for glucose concentration, and 0.90 for percent neutrophils. Interval likelihood ratios were unremarkable for mildly abnormal test results. In contrast, interval likelihood ratios for markedly abnormal test results were higher: 22 for total protein concentration >120 mg/dL, 57 for neutrophils >75%, 15 for glucose concentration <20 mg/dL, and 20 for glucose concentration >120 mg/dL. Conclusions: When markedly abnormal, results of CSF total protein concentration, glucose concentration, and percent neutrophils have value for diagnosing acute bacterial meningitis, even among children with a low WBC count in CSF.
The Prevalence and Perceived Health Consequences of Hunger in Emergency Department Patient Populations
Authors: Biros Michelle H. , Hoffman Pamela L. , Resch Karen
Published: April 2005

Objectives: Hunger is associated with chronic poor health and may force patients to make choices that acutely impact their health. This study was conducted to determine the prevalence of hunger, some of the choices it forces, and its perceived health effects among emergency department (ED) patients. Methods: A validated survey about hunger, choosing between food and medicine, and perceived adverse health outcomes was administered in English, Spanish, and Somali to non‐critically ill ED patients or their parents. Demographics, rates of hunger, numbers of yearly ED visits, and decisions between buying commodities or medications were assessed. Relationships between variables were summarized with odds ratios (ORs), 95% confidence intervals, and logistic regression. Results: Of 930 respondents, 23.7% screened positive for hunger and 17.6% bought food instead of medications. Among the hunger‐positive respondents, 44% believed this choice caused illness, and of these, 69% sought ED assessment and 35% believed they were hospitalized because of this choice. Predictors of hunger were low income (OR = 3.3), illicit drug use (OR = 5.5), chronic illness (OR = 2.1), Hispanic ethnicity (OR = 1.9), and lack of insurance (OR = 1.8). Buying food instead of medicine was predicted by low income (OR = 2.5), chronic illness (OR = 2.4), and lack of insurance (OR = 3.4). Predictors of illness were chronic illness (OR = 1.8), lack of insurance (OR = 2.8), African American race (OR = 2.0), and “poor” health (OR = 1.9). Conclusions: These ED patients have high rates of hunger and often choose to buy food instead of medications. Many believe that this choice results in ED visits and hospitalizations. Socioeconomic factors may predict hunger and subsequent ill health.
The Educational Intervention “GRIEV_ING” Improves the Death Notification Skills of Residents
Authors: Hobgood Cherri , Harward Donna , Newton Kelly , Davis William
Published: April 2005

Background: Death notification is a common, difficult, and emotionally laden communication for emergency physicians. Teaching emergency medicine residents the skills for success in this communication is an important focus for educators. To accomplish this task, educators need practical, proven teaching and assessment tools focused on death notification skills. Objectives: To test the hypothesis that a teaching module, based on the mnemonic “GRIEV_ING,” could improve resident confidence, competency, and communication skills when delivering a death notification. Methods: The GRIEV_ING intervention consisted of a two‐hour educational session composed of small‐group, role‐play, and didactic experiences. The authors used a pre–post–retention repeated‐measures design to test their hypothesis immediately following and three months after training. For each assessment cycle, three quantitative measures were collected: self‐confidence, relationship–communication, and competency. Relationship–communication and competency scores were collected during simulated survivor encounters. Results: Complete data for 20 residents were obtained. Significant improvements were noted in resident confidence scores at the pre–post (F = 16.7, p <0.0001) and pre–retention (F = 14.0, p = 0.001) comparisons. Likewise, significant improvements were noted in resident competence scores at the pre–post (F = 4.7, p = 0.04) and pre–retention (F = 8.8, p = 0.008) comparisons. Resident relationship–communication scores were uniformly high, and there was no significant change in this score across study intervals. Conclusions: This study demonstrates that a defined educational intervention focused on the GRIEV_ING mnemonic can improve physician confidence and competence in death notification.
Faculty Development
Authors: McLaughlin Steven A.
Published: April 2005

As emergency medicine faculty, we are called upon to be skilled in a great number of different areas. Residency training prepares us to be knowledgeable clinicians, skillful at procedures, good communicators, and effective at multitasking. Rarely, however, does it prepare us as educators or in the nuances of career advancement in an academic environment. Faculty development is a term used to describe both our growth as clinician–educators and navigation of the tenure and promotion process. An important role of medical student educators is to assist in preparing themselves and the faculty to be good teachers. In addition, we all hope to have successful careers as clinician–educators. The goal of this report is 2‐fold: to provide a guide for faculty to advance their skills as educators and to help teaching faculty to advance their academic career. The first section of this report presents an approach to becoming a skilled educator, and the second section focuses on career development as an educator in an academic setting.
Structure-Function Analysis of Squirrel Monkey FK506-Binding Protein 51, a Potent Inhibitor of Glucocorticoid Receptor Activity
Authors: Denny Wesley B. , Prapapanich Viravan , Smith David F. , Scammell Jonathan G.
Published: April 2005

FK506-binding protein 51 (FKBP51) and FKBP52 are large molecular weight immunophilins that are part of the mature glucocorticoid receptor (GR) heterocomplex. These proteins possess peptidyl-prolyl isomerase (PPIase) and tetratricopeptide repeats (TPR) domains that are important for modulation of GR activity. A naturally occurring animal model of glucocorticoid resistance, the squirrel monkey, results from the relative overexpression of FKBP51 that renders the GR in a low-affinity state. In vitro studies demonstrated that the squirrel monkey form of FKBP51 is greater than 6-fold more potent than human FKBP51 in this respect. The goals of these studies were to determine the roles of the TPR and PPIase domains in the inhibitory activity of squirrel monkey FKBP51 and to gain insight into structural features of squirrel monkey FKBP51 responsible for potent inhibition of dexamethasone-stimulated GR activity. Mutations in the TPR of squirrel monkey FKBP51 that inhibit association with heat shock protein 90 blocked GR inhibitory activity. Mutations that abrogate the PPIase activity of squirrel monkey FKBP51 had no effect on GR inhibitory activity. Chimeras of squirrel monkey and human FKBP51 were tested to identify domains responsible for their different inhibitory potencies. Amino acid differences in domains FK1 and FK2 between squirrel monkey and human FKBP51 contribute equally to the enhanced inhibitory activity of squirrel monkey FKBP51. Furthermore, squirrel monkey FKBP51 in which either FK1 or FK2 was deleted lacked GR inhibitory activity. Thus, the potent inhibitory activity of squirrel monkey FKBP51 involves both FK domains and the heat shock protein 90-binding TPR domain.
Integrin αVβ3 Contains a Cell Surface Receptor Site for Thyroid Hormone that Is Linked to Activation of Mitogen-Activated Protein Kinase and Induction of Angiogenesis
Authors: Bergh Joel J. , Lin Hung-Yun , Lansing Lawrence , Mohamed Seema N. , Davis Faith B. , Mousa Shaker , Davis Paul J.
Published: April 2005

Integrin αVβ3 is a heterodimeric plasma membrane protein whose several extracellular matrix protein ligands contain an RGD recognition sequence. This study identifies integrin αVβ3 as a cell surface receptor for thyroid hormone [l-T4 (T4)] and as the initiation site for T4-induced activation of intracellular signaling cascades. Integrin αVβ3 dissociably binds radiolabeled T4 with high affinity, and this binding is displaced by tetraiodothyroacetic acid, αVβ3 antibodies, and an integrin RGD recognition site peptide. CV-1 cells lack nuclear thyroid hormone receptor, but express plasma membrane αVβ3; treatment of these cells with physiological concentrations of T4 activates the MAPK pathway, an effect inhibited by tetraiodothyroacetic acid, RGD peptide, and αVβ3 antibodies. Inhibitors of T4 binding to the integrin also block the MAPK-mediated proangiogenic action of T4. T4-induced phosphorylation of MAPK is inhibited by small interfering RNA knockdown of αV and β3. These findings suggest that T4 binds to αVβ3 near the RGD recognition site and show that hormone-binding to αVβ3 has physiological consequences.
Cell Cycle Progression Stimulated by Tamoxifen-Bound Estrogen Receptor-α and Promoter-Specific Effects in Breast Cancer Cells Deficient in N-CoR and SMRT
Authors: Keeton Erika Krasnickas , Brown Myles
Published: April 2005

Estrogen receptor α (ERα) mediates the effects of estrogens in breast cancer development and growth via transcriptional regulation of target genes. Tamoxifen can antagonize ERα activity and has been used in breast cancer therapy. Tamoxifen-bound ERα associates with nuclear receptor corepressor (N-CoR) and silencing mediator for retinoid and thyroid hormone receptors (SMRT) at certain target genes. Here we show the effects of reducing N-CoR and SMRT levels on the actions of estrogen and tamoxifen in breast cancer cells. Silencing both corepressors led to tamoxifen-stimulated cell cycle progression without activation of the ERα target genes c-myc, cyclin D1, or stromal cell-derived factor 1, which play a role in estrogen-induced proliferation. By contrast, expression of X-box binding protein 1 was markedly elevated in tamoxifen-treated cells in which N-CoR and SMRT had been silenced. The gain in cell cycle entry seen with tamoxifen when N-CoR and SMRT were silenced was dependent on ERα and not observed upon treatment with estradiol or epidermal growth factor. These results suggest that N-CoR and SMRT play an active role in preventing tamoxifen from stimulating proliferation in breast cancer cells through repression of a subset of target genes involved in ERα function and cell proliferation.
Ab-Initio X-Ray Powder Structure Analysis of Two Polymorphs of Dihydroxysilicon Phthalocyanine
Authors: Kojima Yuko , Osano Yasuko T , Ohashi Toyoshi
Published: April 2005

This paper reports on the synthesis and ab-initio X-ray powder structure determination of two polymorphs of [Si(OH)2Pc], where Pc = phtalocyaninato. We found that one of the polymorphs (Phase II) shows high sensitivity for an electrophotographic photoreceptor, but that the other (Phase I) doesn’t have photosensitivity. The difference in the sensitivity depends on only the crystal structures. This material has not been able to be grown to a single crystal with sufficient size for single crystal X-ray analysis, but it is very important to determine the crystal structures of the two polymorphs for understanding the mechanism of the performance of the electrophotographic photoreceptor. In this work we carried out ab-initio X-ray powder structure analysis. The compound crystallizes in space group (Phase I), Z = 1 with unit-cell parameters of a = 12.992(1), b = 7.2830(8), c = 6.861(1) Å, α = 104.413(7)°, β = 101.757(8)°, γ = 96.973(6)° and in space group P21/n (Phase II), Z = 2 with unit-cell parameters of a = 12.7494(5), b = 14.5778(6), c = 6.7727(3) Å, β = 94.353(2)°. Both phases have symmetry center in the molecules (on Si atom) and intermolecular hydrogen bonds (O–H···N). These hydrogen bond modes of Phase I and Phase II are the same. The main difference in packings was revealed between the crystals : Phase II crystal has the herringbone structure, while in Phase I all molecules form the parallel stack columns.
Synthesis, Structure, and Characterization of a Sulfate-Bridged Oxomolybdenum(V) Porphyrin Dimer and Related Monomers Including a Nitrate Complex
Authors: Okubo Yutaka , Okamura Akie , Imanishi Katsuya , Tachibana Junichi , Umakoshi Keisuke , Sasaki Yoichi , Imamura Taira
Published: April 2005

New oxomolybdenum(V) porphyrin complexes, [MoO(tmp)(C6H5SO3)] 1, [MoO(tpp)(C6H5SO3)] 2, [MoO(tpp)(HSO4)] 3, [{MoO(tpp)}2(μ-SO4)] 4, and [MoO(tpp)(NO3)] 5, were synthesized and characterized by UV-vis, IR, FAB-MS, and ESR measurements. The structures of the complexes, 1, 4, and 5, were determined by X-ray crystallographic analysis. The benzenesulfonate ion in 1 and the nitrate ion in 5 coordinate to the molybdenum atom as monodentate ligands. The oxidation number of the central molybdenum ion of these complexes was confirmed to be 5+ by ESR measurements. In the dinuclear complex 4, a sulfate ion bridges two molybdenum porphyrins. The dinuclear complex 4 exhibited spin coupling between the two molybdenum nuclei.
Enantioselective Protonation of Lithium Enolates with Chiral Imides Possessing a Chiral Amide
Authors: Yanagisawa Akira , Kikuchi Tetsuo , Watanabe Tsuyoshi , Yamamoto Hisashi
Published: April 2005

New chiral imides possessing a chiral amide can be prepared from 1,3,5-trimethyl-r-1,c-3,c-5-cyclohexanetricarboxylic acid or related triacids and optically active amines. These imides are superior to 1,3,5-trimethyl-c-5-[(4S,5S)-4,5-diphenyl-2-oxazolin-2-yl]-r-1,c-3-cyclohexanedicarboximide reported previously as a chiral proton source for enantioselective protonation of lithium enolates of 2-alkylcycloalkanones.
Fiber Content and Myosin Heavy Chain Composition of Muscle Spindles in Aged Human Biceps Brachii
Authors: Liu Jing-Xia , Eriksson Per-Olof , Thornell Lars-Eric , Pedrosa-Domellöf Fatima
Published: April 2005

The present study investigated potential age-related changes in human muscle spindles with respect to the intrafusal fiber-type content and myosin heavy chain (MyHC) composition in biceps brachii muscle. The total number of intrafusal fibers per spindle decreased significantly with aging, due to a significant reduction in the number of nuclear chain fibers. Nuclear chain fibers in old spindles were short and some showed novel expression of MyHC α-cardiac. The expression of MyHC α-cardiac in bag1 and bag2 fibers was greatly decreased in the A region. The expression of slow MyHC was increased in nuclear bag1 fibers and that of fetal MyHC decreased in bag2 fibers whereas the patterns of distribution of the remaining MyHC isoforms were generally not affected by aging. We conclude that aging appears to have an important impact on muscle spindle composition. These changes in muscle spindle phenotype may reflect an age-related deterioration in sensory and motor innervation and are likely to have an impact in motor control in the elderly.
Altered Expression Patterns of Heterogeneous Nuclear Ribonucleoproteins A2 and B1 in the Adrenal Cortex
Authors: Wu WenWen , Kamma Hiroshi , Fujiwara Masachika , Yano Yukiko , Satoh Hiroaki , Hara Hisatoh , Yashiro Tohru , Ueno Ei , Aiyoshi Yuji
Published: April 2005

Several proteins implicated in hormonogenesis of the adrenal cortex have alternatively spliced isoforms, which respond differently to adrenocorticotropic hormone (ACTH). Heterogeneous nuclear ribonucleoproteins A2 and B1 are among the abundant pre-mRNA-binding proteins involved in alternative splicing. We examined the expression of A2 and B1 in normal adrenal cortex and tumors. B1 was variably expressed in the zona fasciculata-reticularis, although A2 was diffusely expressed in the three zones. B1 was more abundant in compact cells than clear cells, and B1 expression was frequent in the zona reticularis, which consists mainly of compact cells. In three kinds of cortical adenomas autonomously producing hormones, B1 was generally overexpressed and there were no significant differences among them. In cortisol-producing tumors, non-tumor parts of the cortex, which were generally atrophic due to low ACTH, had less B1 protein than normal adrenals. These results suggested a correlation between B1 expression and the hormonal activity responding to ACTH. In vitro ACTH stimulation induced a biphasic expression of B1 in an H295R cortical carcinoma cell line, and it paralleled hormonogenesis. Conclusively, B1 expression varied in relation to the hormonal activity responding to the ACTH, and it may provide a key to elucidating the splicing mechanisms involved in hormonogenesis.
Immunocytochemistry for Drugs Containing an Aliphatic Primary Amino Group in the Molecule, Anticancer Antibiotic Daunomycin as a Model
Authors: Fujiwara Kunio , Takatsu Hironori , Tsukamoto Kazuhiro
Published: April 2005

An immunocytochemistry (ICC) for the anticancer antibiotic daunomycin (DM) was developed using a combination of anti-DM serum produced against N-(gamma-male-imidobutyryloxy)succinimide (GMBS)-conjugated DM, and DM-uptake human melanoma BD cells. The antiserum was demonstrated to be specific for DM and the structurally related analogs adriamicin and epirubicin by an ICC model system of the enzyme immunoassay (EIA) using glutaraldehyde (GA)-conjugated DM as a solid phase antigen. No cross-reaction occurred with any of the other antibiotics tested such as bleomycin, pepleomycin, and mitomycin C. Successful DM ICC required a series of processes prior to the immunocytochemical reaction: the cells were first fixed with GA, then reduced with NaBH4, treated with hydrochloric acid, and finally digested with protease. The cell specimens were then subjected to immunoreaction with anti-DM serum followed by peroxidase-labeled goat anti-rabbit IgG/Fab', and in both immune reagents the detergent Triton X-100 was contained as well. The present ICC covering all these processes successfully stained for DM in the nucleus and in the perinuclear Golgi region of the cytoplasm of the BD cells, consistent with the results obtained by the DM autofluorescence method. This ICC was found to be three times as sensitive as the cytofluorometric method and applicable to the paraffin sections of the liver of rats 24 hr after an IV injection of DM. The principle used in the present study for developing DM ICC might be applied to other drugs containing the primary amino group(s) in the molecule. Thus, these ICCs for drugs are direct, precise and easy new methods that should have potential for pharmacology and toxicology studies of drugs, revealing the localization of a drug in cells and tissues.
Multiple Roles for Elastic Fibers in the Skin
Authors: Starcher Barry , Aycock Ronnie L. , Hill Charles H.
Published: April 2005

Dermal elastic fibers are believed to have a primary role in providing elastic stretch and recoil to the skin. Here we compare the structural arrangement of dermal elastic fibers of chick skin and different animal species. Most elastic fibers in chick skin are derived from cells that line the feather follicle and/or smooth muscle that connects the pterial and apterial muscle bundles to feather follicles. Elastic fibers in the dermis of animals with single, primary hair follicles are derived from cells lining the hair follicle or from the ends of the pili muscle, which anchors the muscle to the matrix or to the hair follicle. Each follicle is interconnected with elastic fibers. Follicles of animals with primary and secondary (wool) hair follicles are also interconnected by elastic fibers, yet only the elastic fibers derived from the primary follicle are connected to each primary follicle. Only the primary hair follicles are connected to the pili muscle. Human skin, but not the skin of other primates, is significantly different from other animals with respect to elastic fiber organization and probably cell of origin. The data suggest that the primary role for elastic fibers in animals, with the possible exception of humans, is movement and/or placement of feathers or hair.
Chromatoid Bodies: Aggresome-like Characteristics and Degradation Sites for Organelles of Spermiogenic Cells
Authors: Haraguchi Celina M. , Mabuchi Tadashi , Hirata Shuji , Shoda Tomoko , Hoshi Kazuhiko , Akasaki Kenji , Yokota Sadaki
Published: April 2005

We investigated the localization of several markers for lysosomes and aggresomes in the chromatoid bodies (CBs) by immunoelectron microscopy. We found so-called aggresomal markers such as Hsp70 and ubiquitin in the core of the CBs and vimentin and proteasome subunit around the CBs. Ubiquitin-conjugating enzyme (E2) was also found in the CBs. In tubulovesicular structures surrounding the CBs, lysosomal markers were detected but an endoplasmic reticulum retention signal (KDEL) was not. Moreover, proteins located in each subcellular compartment, including the cytosol, mitochondria, and nucleus, were detected in the CBs. Signals for cytochrome oxidase I (COXI) coded on mitochondrial DNA were also found in the CBs. Quantitative analysis of labeling density showed that all proteins examined were concentrated in the CBs to some extent. These results show that the CBs have some aggresomal features, suggesting that they are not a synthetic site as proposed previously but a degradation site where unnecessary DNA, RNA, and proteins are digested.
Monoclonal Antibodies to Plant Cell Wall Xylans and Arabinoxylans
Authors: McCartney Lesley , Marcus Susan E. , Knox J. Paul
Published: April 2005

Two rat monoclonal antibodies have been generated to plant cell wall (1→4)-β-D-xylans using a penta-1,4-xylanoside-containing neoglycoprotein as an immunogen. The monoclonal antibodies, designated LM10 and LM11, have different specificities to xylans in relation to the substitution of the xylan backbone as indicated by immunodot assays and competitive-inhibition ELISAs. LM10 is specific to unsubstituted or low-substituted xylans, whereas LM11 binds to wheat arabinoxylan in addition to unsubstituted xylans. Immunocytochemical analyses indicated the presence of both epitopes in secondary cell walls of xylem but differences in occurrence in other cell types.
Predictions of adsorption behaviour of the heaviest elements in a comparative study from the electronic structure calculations
Authors: Pershina Valeria
Published: April 2005

Thermodynamics of adsorption of gaseous species on the surface of a gas chromatography column is considered using the knowledge of the electronic structure of the adsorbate. Relevant equations based on a model of mobile adsorption are offered to predict the adsorption temperature, T
ads, of a heavy-element (or its compound) with respect to T
ads of its lighter homolog (or the same type of compound). A case of adsorption of OsO4 and HsO4 on an inert (quartz or silicon nitride) surface of a chromatography column is taken, as an example. The influence of various properties of the adsorbate, such as molecular weight and size, on T
ads is analyzed to show that those factors should not be ignored in intentionally accurate predictions of T
ads. A comparison of the desorption constants of OsO4 and HsO4 obtained with the use of the calculated spectroscopic properties shows that HsO4 should be significantly more volatile than OsO4, mainly due to the entropy factor.
Corrosion of commercial spent nuclear fuel. 1. Formation of studtite and metastudtite
Authors: Hanson Brady D. , McNamara Bruce , Buck Edgar C. , Friese Judah I. , Jenson Evan , Krupka Kenneth , Arey Bruce W.
Published: April 2005

The contact of commercial spent nuclear fuel (CSNF) with water over a 2-year period led to an unexpected corrosion phase and morphology. At short hydration times, crystallites of metaschoepite [(UO2)8O2(OH)12](H2O)10 were observed on the hydrated CSNF particles. Over the 2-year contact period, all evidence of metaschoepite disappeared, and the fuel particles were coated by a new alteration phase. Additionally, films of the reacted fuel were observed at the sample air-water interface of each sample. The corrosion phases on fuel powders and on the suspended films were examined by scanning electron microscopy, energy-dispersive X-ray fluorescence, and X-ray diffraction and were identified as studtite [(UO2)(O2)(H2O)2](H2O)2 and metastudtite (UO4·2H2O), respectively. The reason for the partitioning of the latter phase to the sample air-water interface is unclear at this time but may be due to structural differences between the two phases. Scanning electron micrographs of the CSNF powders indicated surface corrosion along grain boundaries and fragmentation of the primary solid. The occurrence of studtite and metastudtite on CSNF could have implications for the potential attenuation of released radionuclides during oxidative corrosion of CSNF in a geologic repository.
Solid phase sorption of microamount of Hg(II) onto 1-(2-thiazolylazo)-2-naphthol (TAN) loaded polyurethane foam
Authors: Saeed Muhammad M. , Bajwa Sadia Z. , Ansari Muhammad S. , Ahmed Riaz
Published: April 2005

Mercury is a toxic environmental pollutant. A method has been developed to remove these metal ions by preconcentrating onto 1-(2-thiazolylazo)-2-naphthol (TAN) loaded polyurethane (PUR) foam that proves an excellent sorbent for these metal ions. The accumulation conditions are optimized with respect to pH, shaking time, loading capacity and adsorbent weight. The optimum pH for sorption was found to be 7, which is close to the natural water. Optimum shaking time for Hg(II) is 30 min. The kinetic studies indicate that sorption occurs through intraparticle diffusion process. Classical adsorption isotherms are applied to determine the nature of sorption. The sorption free energy value indicates that adsorption process is chemisorption. Effect of temperature has been used to compute the values of ΔH, ΔS and ΔG for Hg(II). These are 19.0±0.9 kJ mol−1, 80.73±0.1 J K−1 mol−1, −5.1±0.9 kJ mol−1 respectively. Adsorption of metal ions is endothermic, spontaneous and entropy driven. Effect of different anions and cations are observed. Adsorption via Hg(II)-TAN complex formation on PUR foam was supported by spectrophotometric studies.
Single-crystal-to-single-crystal [2 + 2] photodimerizations: from discovery to design
Authors: Friščić Tomislav , MacGillivray Leonard R.
Published: April 2005

The purpose of this review is to address fundamentals and applications of single-crystal-to-single-crystal (SCSC) reactions, based on the [2 + 2] photodimerization. An overview of SCSC [2 + 2] photodimerizations, which comprise single- and multi-component solids, will be given. We reveal that materials that exhibit SCSC reactivity can be considered to have been achievedviaeither discovery or design. We suggest that SCSC [2 + 2] photodimerizations, if generally achieved, could provide new avenues to control bulk physical properties of solid-state materials.
Supramolecular inorganic frameworks: “dynamic” challenges for structural chemistry
Authors: May Leslie J. , Shimizu George K. H.
Published: April 2005

The supramolecular chemistry of discrete assemblies of various topologies (cages, grids, helices, etc.) has been extensively studied. With regards to the supramolecular chemistry of infinite solids, attention is usually focussed on the design of an efficient, programmed assembly motif through the choice of suitable building blocks. However, as well illustrated by the discrete structures, a hallmark property of a supramolecular system is its ability to reversibly assemble to optimize its structure, effectively error checking. For a rigid infinite framework, this feature is less obvious. Error checking is manifested in an extended framework through structural rearrangements in the solid state. Coordination frameworks, as they are often at least partially sustained by weaker interactions, can demonstrate such dynamic behavior in response to some external stimulus. Selected examples, chosen to illustrate a range of network types and rearrangements, will be discussed in this short review.
A High-Frequency Null Mutant of an Odorant-Binding Protein Gene, Obp57e, in Drosophila melanogaster
Authors: Takahashi Aya , Takano-Shimizu Toshiyuki
Published: April 2005

We have found a null mutant of an odorant-binding protein, Obp57e, in Drosophila melanogaster. This frameshift mutation, which is a 10-bp deletion in the coding region, is at a high frequency in the Kyoto population and is also present in Taiwan and Africa. We have sequenced a 1.5-kb region including the tandemly duplicated gene, Obp57d, from 16 inbred lines sampled in Kyoto, Japan. The analyses showed a peak of nucleotide diversity and strong linkage disequilibrium around this mutation. This pattern suggests an elevated mutation rate or an influence of balancing selection in this region. The level of nucleotide divergence between D. melanogaster and D. simulans does not support the former possibility. Thus, this presence/absence polymorphism may be due to balancing selection, which takes advantage of the relatively weak functional constraint in members of a large gene family. In addition, the Obp57d gene region showed an excess of high-frequency-derived mutants that is consistent with a pattern predicted under positive natural selection.
A Mitogen-Activated Protein Kinase Pathway Essential for Mating and Contributing to Vegetative Growth in Neurospora crassa
Authors: Li Dan , Bobrowicz Piotr , Wilkinson Heather H , Ebbole Daniel J
Published: April 2005

MAP kinases homologous to Saccharomyces cerevisiae Fus3p/Kss1p have been identified in plant pathogenic fungi and are required for pathogenicity and sexual reproduction. To better understand the role of MAP kinase signaling in Neurospora crassa, and to identify downstream target genes of the pathway, we isolated, cloned, and disrupted the FUS3 homolog mak-2. Ste12p is a transcription factor target of Fus3p that activates genes of the mating pathway in yeast, and we also characterized the N. crassa STE12 homolog pp-1. The mak-2 and pp-1 mutants have reduced growth rate, produce short aerial hyphae, and fail to develop protoperithecia. In addition, ascospores carrying null mutations of either gene are inviable. Subtractive cloning was used to isolate genes having reduced expression in the mak-2 mutant. Expression of some of these genes is protoperithecia specific and three of them are part of a gene cluster potentially involved in the production of a polyketide secondary metabolite. Microarray analysis was used to extend the analysis of gene expression in mak-2 and pp-1 mutants. The role of the MAP kinase pathway in both sexual and asexual development as well as secondary metabolism is consistent with the dual regulation of the mating process and pathogencity observed in fungal pathogens.
The Program of Sex Chromosome Pairing in Meiosis Is Highly Conserved Across Marsupial Species
Authors: Page Jesús , Berríos Soledad , Parra María Teresa , Viera Alberto , Suja José Ángel , Prieto Ignacio , Barbero José Luis , Rufas Julio S , Fernández-Donoso Raúl
Published: April 2005

Marsupials present a series of genetic and chromosomal features that are highly conserved in very distant species. One of these features is the absence of a homologous region between X and Y chromosomes. According to this genetic differentiation, sex chromosomes do not synapse during the first meiotic prophase in males, and a special structure, the dense plate, maintains sex chromosome association. In this report we present results on the process of meiotic sex chromosome pairing obtained from three different species, Thylamys elegans, Dromiciops gliroides, and Rhyncholestes raphanurus, representing the three orders of American marsupials. We have investigated the relationships between the axial structures organized along sex chromosomes and the formation of the dense plate. We found that in the three species the dense plate arises as a modification of sex chromosomal axial elements, but without the involvement of other meiotic axial structures, such as the cohesin axes. Considering the phylogenetic relationships among the marsupials studied here, our data reinforce the idea that the dense plate emerged early in marsupial evolution as an efficient mechanism to ensure the association of the nonhomologous sex chromosomes. This situation could have influenced the further evolution of sex chromosomes in marsupials.
Chromosome Sorting in Tetraploid Wheat and Its Potential for Genome Analysis
Authors: Kubaláková Marie , Kovářová Pavlína , Suchánková Pavla , Číhalíková Jarmila , Bartoš Jan , Lucretti Sergio , Watanabe Nobuyoshi , Kianian Shahryar F , Doležel Jaroslav
Published: April 2005

This study evaluates the potential of flow cytometry for chromosome sorting in durum wheat (Triticum turgidum Desf. var. durum, 2n = 4x = 28). Histograms of fluorescence intensity (flow karyotypes) obtained after the analysis of DAPI-stained chromosomes consisted of three peaks. Of these, one represented chromosome 3B, a small peak corresponded to chromosomes 1A and 6A, and a large peak represented the remaining 11 chromosomes. Chromosomes sorted onto microscope slides were identified after fluorescence in situ hybridization (FISH) with probes for GAA microsatellite, pSc119.2, and Afa repeats. Genomic distribution of these sequences was determined for the first time in durum wheat and a molecular karyotype has been developed for this crop. Flow karyotyping in double-ditelosomic lines of durum wheat revealed that the lines facilitated sorting of any arm of the wheat A- and B-genome chromosomes. Compared to hexaploid wheat, flow karyotype of durum wheat is less complex. This property results in better discrimination of telosomes and high purities in sorted fractions, ranging from 90 to 98%. We have demonstrated that large insert libraries can be created from DNA purified using flow cytometry. This study considerably expands the potential of flow cytogenetics for use in wheat genomics and opens the possibility of sequencing the genome of this important crop one chromosome arm at a time.
The Phosphatase Subunit Tap42 Functions Independently of Target of Rapamycin to Regulate Cell Division and Survival in Drosophila
Authors: Cygnar Katherine D , Gao Xinsheng , Pan Duojia , Neufeld Thomas P
Published: April 2005

The protein phosphatase 2A (PP2A) regulatory subunit Tap42 is essential for target of rapamycin (TOR)-mediated signaling in yeast, but its role in higher eukaryotes has not been established. Here we show that Tap42 does not contribute significantly to TOR signaling in Drosophila, as disruption of the Tap42 gene does not cause defects in cell growth, metabolism, or S6-kinase activity characteristic of TOR inactivation. In addition, Tap42 is not required for increased cell growth in response to activation of TOR signaling. Instead, we find that Tap42 mutations cause disorganization of spindle microtubules in larval neuroblasts, leading to a preanaphase mitotic arrest in these cells. Loss of Tap42 ultimately results in increased JNK signaling, caspase activation, and cell death. These phenotypes are associated with increased accumulation and nuclear localization of PP2A in Tap42 mutant cells. Our results demonstrate that the role of Tap42 in TOR signaling has not been conserved in higher eukaryotes, indicating fundamental differences in the mechanisms of TOR signaling between yeast and higher eukaryotes.
Theoretical Basis for the Identification of Allelic Variants That Encode Drug Efficacy and Toxicity
Authors: Lin Min , Wu Rongling
Published: April 2005

Almost all drugs that produce a favorable response (efficacy) may also produce adverse effects (toxicity). The relative strengths of drug efficacy and toxicity that vary in human populations are controlled by the combined influences of multiple genes and environmental influences. Genetic mapping has proven to be a powerful tool for detecting and identifying specific DNA sequence variants on the basis of the haplotype map (HapMap) constructed from single-nucleotide polymorphisms (SNPs). In this article, we present a novel statistical model for sequence mapping of two different but related drug responses. This model is incorporated by mathematical functions of drug response to varying doses or concentrations and the statistical device used to model the correlated structure of the residual (co)variance matrix. We implement a closed-form solution for the EM algorithm to estimate the population genetic parameters of SNPs and the simplex algorithm to estimate the curve parameters describing the pharmacodynamic changes of different genetic variants and matrix-structuring parameters. Extensive simulations are performed to investigate the statistical properties of our model. The implications of our model in pharmacogenetic and pharmacogenomic research are discussed.
DNA Variation at the Invertase Locus invGE/GF Is Associated With Tuber Quality Traits in Populations of Potato Breeding Clones
Authors: Li Li , Strahwald Josef , Hofferbert Hans-Reinhard , Lübeck Jens , Tacke Eckart , Junghans Holger , Wunder Jörg , Gebhardt Christiane
Published: April 2005

Starch and sugar content of potato tubers are quantitative traits, which are models for the candidate gene approach for identifying the molecular basis of quantitative trait loci (QTL) in noninbred plants. Starch and sugar content are also important for the quality of processed products such as potato chips and French fries. A high content of the reducing sugars glucose and fructose results in inferior chip quality. Tuber starch content affects nutritional quality. Functional and genetic models suggest that genes encoding invertases control, among other things, tuber sugar content. The invGE/GF locus on potato chromosome IX consists of duplicated invertase genes invGE and invGF and colocalizes with cold-sweetening QTL Sug9. DNA variation at invGE/GF was analyzed in 188 tetraploid potato cultivars, which have been assessed for chip quality and tuber starch content. Two closely correlated invertase alleles, invGE-f and invGF-d, were associated with better chip quality in three breeding populations. Allele invGF-b was associated with lower tuber starch content. The potato invertase gene invGE is orthologous to the tomato invertase gene Lin5, which is causal for the fruit-sugar-yield QTL Brix9-2-5, suggesting that natural variation of sugar yield in tomato fruits and sugar content of potato tubers is controlled by functional variants of orthologous invertase genes.
The Bombyx mori Karyotype and the Assignment of Linkage Groups
Authors: Yoshido Atsuo , Bando Hisanori , Yasukochi Yuji , Sahara Ken
Published: April 2005

Lepidopteran species have a relatively high number of small holocentric chromosomes (Bombyx mori, 2n = 56). Chromosome identification has long been hampered in this group by the high number and by the absence of suitable markers like centromere position and chromosome bands. In this study, we carried out fluorescence in situ hybridization (FISH) on meiotic chromosome complements using genetically mapped B. mori bacterial artificial chromosomes (BACs) as probes. The combination of two to four either green or red fluorescence-labeled probes per chromosome allowed us to recognize unequivocally each of the 28 bivalents of the B. mori karyotype by its labeling pattern. Each chromosome was assigned one of the already established genetic linkage groups and the correct orientation in the chromosome was defined. This facilitates physical mapping of any other sequence and bears relevance for the ongoing B. mori genome projects. Two-color BAC-FISH karyotyping overcomes the problem of chromosome recognition in organisms where conventional banding techniques are not available.
The C-Terminal Half of Saccharomyces cerevisiae Mad1p Mediates Spindle Checkpoint Function, Chromosome Transmission Fidelity and CEN Association
Authors: Kastenmayer James P , Lee Marina S , Hong Andrew L , Spencer Forrest A , Basrai Munira A
Published: April 2005

The evolutionarily conserved spindle checkpoint is a key mechanism ensuring high-fidelity chromosome transmission. The checkpoint monitors attachment between kinetochores and mitotic spindles and the tension between sister kinetochores. In the absence of proper attachment or tension, the spindle checkpoint mediates cell cycle arrest prior to anaphase. Saccharomyces cerevisiae Mad1p is required for the spindle checkpoint and for chromosome transmission fidelity. Moreover, Mad1p associates with the nuclear pore complex (NPC) and is enriched at kinetochores upon checkpoint activation. Using partial mad1 deletion alleles we determined that the C-terminal half of Mad1p is necessary and sufficient for checkpoint activation in response to microtubule depolymerizing agents, high-fidelity transmission of a reporter chromosome fragment, and in vivo association with centromeres, but not for robust NPC association. Thus, spindle checkpoint activation and chromosome transmission fidelity correlate and these Mad1p functions likely involve kinetochore association but not robust NPC association. These studies are the basis for elucidating the role of protein complexes containing Mad1p in the spindle checkpoint pathway and in maintaining genome stability in S. cerevisiae and other systems.
Origins of Host-Specific Populations of the Blast Pathogen Magnaporthe oryzae in Crop Domestication With Subsequent Expansion of Pandemic Clones on Rice and Weeds of Rice
Authors: Couch Brett C , Fudal Isabelle , Lebrun Marc-Henri , Tharreau Didier , Valent Barbara , van Kim Pham , Nottéghem Jean-Loup , Kohn Linda M
Published: April 2005

Rice, as a widely and intensively cultivated crop, should be a target for parasite host shifts and a source for shifts to co-occurring weeds. Magnaporthe oryzae, of the M. grisea species complex, is the most important fungal pathogen of rice, with a high degree of host specificity. On the basis of 10 loci from six of its seven linkage groups, 37 multilocus haplotypes among 497 isolates of M. oryzae from rice and other grasses were identified. Phylogenetic relationships among isolates from rice (Oryza sativa), millet (Setaria spp.), cutgrass (Leersia hexandra), and torpedo grass (Panicum repens) were predominantly tree like, consistent with a lack of recombination, but from other hosts were reticulate, consistent with recombination. The single origin of rice-infecting M. oryzae followed a host shift from a Setaria millet and was closely followed by additional shifts to weeds of rice, cutgrass, and torpedo grass. Two independent estimators of divergence time indicate that these host shifts predate the Green Revolution and could be associated with rice domestication. The rice-infecting lineage is characterized by high copy number of the transposable element MGR586 (Pot3) and, except in two haplotypes, by a loss of AVR-Co39. Both mating types have been retained in ancestral, well-distributed rice-infecting haplotypes 10 (mainly temperate) and 14 (mainly tropical), but only one mating type was recovered from several derived, geographically restricted haplotypes. There is evidence of a common origin of both ACE1 virulence genotypes in haplotype 14. Host-haplotype association is evidenced by low pathogenicity on hosts associated with other haplotypes.
Evaluation of Noise-Induced Hearing Loss in Young People Using a Web-Based Survey Technique
Authors: Chung Jeannie H. , Des Roches Catherine M. , Meunier John , Eavey Roland D.
Published: April 2005

Objective. Many adolescents and young adults consciously expose themselves to loud music for entertainment. We hypothesized that these individuals might not be aware that exposure to loud music could result in hearing loss. Furthermore, we wished to assess the feasibility of a web-based survey to collect health information from this group.

Methods. A 28-question survey was designed to target adolescents and young adults. The survey contained questions about views toward general health issues, including hearing loss, and was presented to random visitors at the MTV web site.

Results. In 3 days, 9693 web surveys were completed. Hearing loss was defined on a Likert scale as “a very big problem” by 8% of respondents compared with other health issues: sexually transmitted diseases, 50%; alcohol/drug use, 47%; depression, 44%; smoking, 45%; nutrition and weight issues, 31%; and acne, 18%. Notably, most respondents had experienced tinnitus or hearing impairment attending concerts (61%) and clubs (43%). Only 14% of respondents had used earplugs; however, many could be motivated to try ear protection if they were aware of the potential for permanent hearing loss (66%) or were advised by a medical professional (59%).

Conclusions. A majority of young adults have experienced tinnitus and hearing impairment after exposure to loud music. Fortunately, many of these individuals could be motivated to wear ear protection. This novel web-based survey technique rapidly generated a large database and is a feasible method to obtain health data from this group.