bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation and Inference of Impulse Responses by Local Projections
Authors: Jordà Òscar
Published: May 2005

This paper introduces methods to compute impulse responses without specification and estimation of the underlying multivariate dynamic system. The central idea consists in estimating local projections at each period of interest rather than extrapolating into increasingly distant horizons from a given model, as it is done with vector autoregressions (VAR). The advantages of local projections are numerous: (1) they can be estimated by simple regression techniques with standard regression packages; (2) they are more robust to misspecification; (3) joint or point-wise analytic inference is simple; and (4) they easily accommodate experimentation with highly nonlinear and flexible specifications that may be impractical in a multivariate context. Therefore, these methods are a natural alternative to estimating impulse responses from VARs. Monte Carlo evidence and an application to a simple, closed-economy, new-Keynesian model clarify these numerous advantages.
The Cyclical Behavior of Equilibrium Unemployment and Vacancies
Authors: Shimer Robert
Published: May 2005

This paper argues that the textbook search and matching model cannot generate the observed business-cycle-frequency fluctuations in unemployment and job vacancies in response to shocks of a plausible magnitude. In the United States, the standard deviation of the vacancy-unemployment ratio is almost 20 times as large as the standard deviation of average labor productivity, while the search model predicts that the two variables should have nearly the same volatility. A shock that changes average labor productivity primarily alters the present value of wages, generating only a small movement along a downward-sloping Beveridge curve (unemploymentvacancy locus). A shock to the separation rate generates a counterfactually positive correlation between unemployment and vacancies. In both cases, the model exhibits virtually no propagation.
The poly(A)-limiting element enhances mRNA accumulation by increasing the efficiency of pre-mRNA 3′ processing
Authors: PENG JING , MURRAY ELIZABETH L. , SCHOENBERG DANIEL R.
Published: May 2005

The poly(A)-limiting element (PLE) is a conserved sequence originally found in the 3′ UTR of Xenopus albumin mRNA whose presence restricts the length of the poly(A) tail on both pre-mRNA and fully processed mRNA to <20 nt. Results presented in this study show that the PLE also increases the cytoplasmic level of reporter β-globin mRNA. Transcription run-on shows this increase was not due to increased reporter gene transcription, and experiments with tetracycline repressor-controlled reporter mRNA showed the PLE does not alter the rate of mRNA decay. Both RT-PCR and RNase protection assay showed the PLE caused a 50% increase in the 3′ processing of reporter β-globin mRNA in vivo. This was confirmed in vitro, where PLE-containing RNA was cleaved in HeLa nuclear extract at a rate 80% faster than a control RNA bearing an inactive element. These results indicate that the PLE regulates the length of the poly(A) tail and the efficiency of 3′ processing. In addition, they show that PLE-containing mRNA with a <20-nt poly(A) tail is as stable as mRNA with a 100- to 200-nt poly(A) tail.
Ultrastructural Studies and Na+,K+-ATPase Immunolocalization in the Antennal Urinary Glands of the Lobster Homarus gammarus (Crustacea, Decapoda)
Authors: Khodabandeh Saber , Charmantier Guy , Charmantier-Daures Mireille
Published: May 2005

Unlike in crustacean freshwater species, the structure and ultrastructure of the excretory antennal gland is poorly documented in marine species. The general organization and ultrastructure of the cells and the localization of Na+,K+-ATPase were examined in the antennal gland of the adult lobster Homarus gammarus. Each gland is composed of a centrally located coelomosac surrounded ventrally by a labyrinth divided into two parts (I and II) and dorsally by a voluminous bladder. There is no differentiated nephridal tubule between them. The labyrinth and bladder cells have in common a number of ultrastructural cytological features, including basal membrane infoldings associated with mitochondria, apical microvilli, and cytoplasmic extrusions, and a cytoplasm packed with numerous vacuoles, vesicles, lysosome-like bodies, and swollen mitochondria. Each type of cell also presents distinctive characters. Na+,K+-ATPase was detected through immunofluorescence in the basal part of the cells of the labyrinth and in the bladder cells with an increasing immunostaining from labyrinth I to the bladder. No immunoreactivity was detected in the coelomosac. The cells of the labyrinth and of the bladder present morphological and enzymatic features of ionocytes. The antennal glands of the lobster thus possess active ion exchanges capabilities.
Profiles of PrKX Expression in Developmental Mouse Embryo and Human Tissues
Authors: Li Wei , Yu Zu-Xi , Kotin Robert M.
Published: May 2005

Protein kinase × (PrKX), karyotypically located on the human × chromosome, is a type I cAMP-dependent protein kinase. Although a specific role for PrKX has not yet been defined, PrKX gene expression in mouse and human tissues has been profiled only by in situ hybridization and Northern blot analyses and not by protein expression. To determine more precisely the PrKX protein levels, we developed specific anti-PrKX antibodies and examined gestationally staged mouse embryo sections by immunohistochemistry. These results showed that PrKX is ubiquitously distributed and highly expressed in murine central nervous system and heart tissues in early developmental stages and in most organs at later stages but was not detected in either connective tissues or bone. Using Western blots to detect PrKX, total protein extracts from eight different adult or fetal human tissues including brain, heart, kidney, liver, lung, pancreas, spleen, and thymus were analyzed. Although PrKX protein was present in each of the tissues tested, the protein levels varied depending on tissue type and developmental stage. Very low protein levels were found in heart tissues from a 5-month-old fetus and from an adult, whereas PrKX proteins were more abundant in fetal brain, kidney, and liver tissues compared with adult samples of the same tissue type.
Overexpression of eCLCA1 in Small Airways of Horses with Recurrent Airway Obstruction
Authors: Anton Friederike , Leverkoehne Ina , Mundhenk Lars , Thoreson Wallace B. , Gruber Achim D.
Published: May 2005

The human hCLCA1 and murine mCLCA3 (chloride channels, calcium-activated) have recently been identified as promising therapeutic targets in asthma. Recurrent airway obstruction in horses is an important animal model of human asthma. Here, we have cloned and characterized the first equine CLCA family member, eCLCA1. The 913 amino acids eCLCA1 polypeptide forms a 120-kDa transmembrane glycoprotein that is processed to an 80-kDa protein in vivo. Three single nucleotide polymorphisms were detected in the eCLCA1 coding region in 14 horses, resulting in two amino acid changes (485H/R and 490V/L). However, no functional differences were recorded between the channel properties of the two variants in transfected HEK293 cells. The eCLCA1 protein was detected immunohistochemically in mucin-producing cells in the respiratory and intestinal tracts, cutaneous sweat glands, and renal mucous glands. Strong overexpression of eCLCA1 was observed in the airways of horses with recurrent airway obstruction using Northern blot hybridization, Western blotting, immunohistochemistry, and real-time quantitative RT-PCR. The results suggest that spontaneous or experimental recurrent airway obstruction in horses may serve as a model to study the role of CLCA homologs in chronic airway disease with overproduction of mucins.
Development of Species-specific rDNA Probes for Giardia by Multiple Fluorescent In Situ Hybridization Combined with Immunocytochemical Identification of Cyst Wall Antigens
Authors: Erlandsen Stanley L. , Jarroll Edward , Wallis Peter , van Keulen Harry
Published: May 2005

In this study, we describe the development of fluorescent oligonucleotide probes to variable regions in the small subunit of 16S rRNA in three distinct Giardia species. Sense and antisense probes (17–22 mer) to variable regions 1, 3, and 8 were labeled with digoxygenin or selected fluorochomes (FluorX, Cy3, or Cy5). Optimal results were obtained with fluorochome-labeled oligonucleotides for detection of rRNA in Giardia cysts. Specificity of fluorescent in situ hybridization (FISH) was shown using RNase digestion and high stringency to diminish the hybridization signal, and oligonucleotide probes for rRNA in Giardia lamblia, Giardia muris, and Giardia ardeae were shown to specifically stain rRNA only within cysts or trophozoites of those species. The fluorescent oligonucleotide specific for rRNA in human isolates of Giardia was positive for ten different strains. A method for simultaneous FISH detection of cysts using fluorescent antibody (genotype marker) and two oligonucleotide probes (species marker) permitted visualization of G. lamblia and G. muris cysts in the same preparation. Testing of an environmental water sample revealed the presence of FISH-positive G. lamblia cysts with a specific rDNA probe for rRNA, while negative cysts were presumed to be of animal or bird origin.
A comparative evaluation of 238Pu determination in NIST-SRM-947-Pu by alpha spectrometry and thermal ionization mass spectrometry
Authors: Alamelu D. , Shah P. M. , Aggarwal S. K.
Published: May 2005

A comparative evaluation of 238Pu determination in NIST-SRM-947-Pu isotopic reference material by alpha spectrometry and thermal ionization mass spectrometry (TIMS) is presented. Electrodeposited sources with geometric progression (G.P.) method to account for tail contribution were used in alpha spectrometry. In TIMS, the recently developed approach of using 235U as a monitor isotope in interfering element correction methodology was employed to account for the isobaric interference of 238U at 238Pu. The atom % abundance of 238Pu determined by both the methods is in good agreement with each other but is higher than that quoted by NIST in the reference material SRM-947-Pu.
Advanced Laser Imaging Diagnostics in Combustion
Authors: Schulz C.
Published: May 2005

Laser-based imaging diagnostics allow the quantitative determination of scalar fields (concentrations, temperature) in combustion environments. Beyond instantaneous two-dimensional distributions, multi-dimensional imaging can provide simultaneous information about concentration of more than one species and temperature, about three-dimensional concentration and temperature distributions as well as the temporal evolution of reactions, flows and evaporation processes. Various examples in combustion environments are presented.
Action Spectroscopy and Predissociation of Vibrationally Excited C2HD
Authors: Ganot Yuval , Rosenwaks Salman , Bar Ilana
Published: May 2005

H and D photofragments, produced via vibrationally mediated photodissociation of jet-cooled C2HD allowed measurement of vibrational and vibronic excitation action spectra of the parent as well as H and D Doppler profiles. The initial vibrational preparation at energies around 9700 cm−1 enhanced C—H and C—D bond cleavage for transitions from an initially excited bent state to the upper A
~ state, rather than from a close lying state containing three C—H stretch quanta, due to favorable Franck—Condon factors for the former. The bound region of the A
~ state was accessed, resulting in non-adiabatic dissociation and slight preferential C—H over C—D bond cleavage.
Rovibrational Energy Transfer in the 4νCH Manifold of Acetylene, Viewed by IR-UV Double Resonance Spectroscopy. 3. State-to-State J-Resolved Kinetics
Authors: Payne Mark A. , Milce Angela P. , Frost Michael J. , Orr Brian J.
Published: May 2005

Time-resolved infrared-ultraviolet double resonance (IR-UV DR) spectroscopy is used to study the kinetics of collision-induced state-to-state molecular energy transfer between rovibrational states in the 12700-cm−1 4νCH manifold of the electronic ground state of acetylene (C2H2). Particular initial and final rovibrational J-states are prepared and monitored by a pair of tunable laser pulses (IR PUMP and UV PROBE) and the kinetic results recorded by continuously varying the time delay between those pulses at a set sample pressure. After allowing for collision-induced quenching of fluorescence and mass transfer from the IR-UV optical excitation zone (by beam flyout and diffusion), an array of kinetic data for J-resolved energy-transfer channels can be interpreted by means of a mechanistically structured master-equation model. This paper focuses on kinetics derived by probing C2H2 in its 4νCH
J = 12 state (which is affected by intramolecular perturbations and implicated in unusual collision-induced quasi-continuous background effects) and J-resolved collision-induced rovibrational energy transfer with both even ΔJ and (supposedly forbidden) odd ΔJ.
Conditional Velocity Measurements by Simultaneously Applied Laser Doppler Velocimetry and Planar Laser-Induced Fluorescence in a Swirling Natural Gas/Air Flame
Authors: Nauert A. , Dreizler A.
Published: May 2005

By applying joint velocity/scalar measurements, conditional mean axial and radial velocity components are determined in the vicinity of the turbulent flame front of a premixed swirling natural gas/air flame. Two velocity components are measured by laser Doppler velocimetry (LDV) simultaneously with planar laser-induced fluorescence (PLIF) monitoring the hydroxyl radical (OH). The spatial OH distribution is used to tag the instantaneous position of the flame front and can be thereby used to derive conditional velocities. From these measurements the turbulent flux of the mean progress variable is determined which is an important quantity to model premixed flames. One important finding is that for this rather complex but technically realistic geometry, at some locations in the flame brush conditional axial and radial velocities show different behaviour. Thus gas expansion effects can dominate axially whereas in radial direction turbulent fluctuations determine the direction of turbulent transport.
NO Reburn and Formation Chemistry in Methane Diffusion Flames
Authors: Driscoll J. Joshua , Sick Volker , Farrow Roger L. , Schrader Paul E. , Rizos K.-A. , Lindstedt R. Peter
Published: May 2005

We have applied time-resolved picosecond linear laser-induced fluorescence to obtain spatially resolved profiles of NO in laminar methane/air and methane/nitric oxide/air counterflow diffusion flames at atmospheric pressure. Temperature profiles have been measured with broadband CARS of nitrogen. Flames at strain rates from 59 s−1 to 269 s−1 were studied to characterize the strain rate dependence of the NO concentration. The work shows that NO concentrations decrease with increasing strain rate. Comparisons have been made with predicted NO levels obtained using two different chemical kinetic mechanisms (Lindstedt and co-workers and GRI-Mech. 3.0). Computed concentrations are shown to be in good agreement with experimental data. The addition of up to 600 ppm NO to the fuel did permit an assessment of differences in the reburn chemistry between the two mechanisms.
SACM/CT Study of Product Energy Distributions in the Dissociation of n-Propylbenzene Cations
Authors: Troe J. , Ushakov V.G. , Viggiano A. A.
Published: May 2005

The distribution of translational, rotational, and vibrational energies in the fragments (benzylium ions and ethyl radicals) of the dissociation of n-propylbenzene cations has been determined by statistical adiabatic channel model/classical trajectory (SACM/CT) calculations. The reaction was treated by CT calculations of capture processes for transitional modes, starting with specified fragment energies. A short-range valence/long-range ion-induced dipole potential model for the transitional modes was employed. The derived distributions approach the results from phase space theory (PST) at small energies and angular momenta. At larger energies and angular momenta, the shapes of the distribution functions remain similar to those from PST; however, the average translational, rotational, and vibrational energies of the fragments increasingly differ from PST predictions. The present results are consistent with separate SACM/CT calculations on the same potential of specific rate constants k(E,J) and thermally averaged rate constants k
∞(T) of the dissociation/recombination reaction.
Hypopituitarism after traumatic brain injury
Authors: Bondanelli Marta , Ambrosio Maria Rosaria , Zatelli Maria Chiara , De Marinis Laura , Uberti Ettore C degli
Published: May 2005

Traumatic brain injury (TBI) is one of the main causes of death and disability in young adults, with consequences ranging from physical disabilities to long-term cognitive, behavioural, psychological and social defects. Post-traumatic hypopituitarism (PTHP) was recognized more than 80 years ago, but it was thought to be a rare occurrence. Recently, clinical evidence has demonstrated that TBI may frequently cause hypothalamic–pituitary dysfunction, probably contributing to a delayed or hampered recovery from TBI. Changes in pituitary hormone secretion may be observed during the acute phase post-TBI, representing part of the acute adaptive response to the injury. Moreover, diminished pituitary hormone secretion, caused by damage to the pituitary and/or hypothalamus, may occur at any time after TBI. PTHP is observed in about 40% of patients with a history of TBI, presenting as an isolated deficiency in most cases, and more rarely as complete pituitary failure. The most common alterations appear to be gonadotropin and somatotropin deficiency, followed by corticotropin and thyrotropin deficiency. Hyper- or hypoprolactinemia may also be present. Diabetes insipidus may be frequent in the early, acute phase post-TBI, but it is rarely permanent. Severity of TBI seems to be an important risk factor for developing PTHP; however, PTHP can also manifest after mild TBI. Accurate evaluation and long-term follow-up of all TBI patients are necessary in order to detect the occurrence of PTHP, regardless of clinical evidence for pituitary dysfunction. In order to improve outcome and quality of life of TBI patients, an adequate replacement therapy is of paramount importance.
Evaluation of adrenal function in patients with growth hormone deficiency and hypothalamic–pituitary disorders: comparison between insulin-induced hypoglycemia, low-dose ACTH, standard ACTH and CRH stimulation tests
Authors: Maghnie M , Uga E , Temporini F , Di Iorgi N , Secco A , Tinelli C , Papalia A , Casini MR , Loche S
Published: May 2005

Objectives: Patients with organic growth hormone deficiency (GHD) or with structural hypothalamic–pituitary abnormalities may have additional anterior pituitary hormone deficits, and are at risk of developing complete or partial corticotropin (ACTH) deficiency. Evaluation of the integrity of the hypothalamic–pituitary–adrenal axis (HPA) is essential in these patients because, although clinically asymptomatic, their HPA cannot appropriately react to stressful stimuli with potentially life-threatening consequences.

Design and methods: In this study we evaluated the integrity of the HPA in 24 patients (age 4.2–31 years at the time of the study) with an established diagnosis of GHD and compared the reliability of the insulin tolerance test (ITT), short synacthen test (SST), low-dose SST (LDSST), and corticotropin releasing hormone (CRH) test in the diagnosis of adrenal insufficiency.

Results: At a cortisol cut-off for a normal response of 550 nmol/l (20 μg/dl), the response to ITT was subnormal in 11 subjects, 6 with congenital and 5 with acquired GHD. Four patients had overt adrenal insufficiency, with morning cortisol concentrations ranging between 66.2–135.2 nmol/l (2.4–4.9 μg/dl) and typical clinical symptoms and laboratory findings. In all these patients, a subnormal cortisol response to ITT was confirmed by LDSST and by CRH tests. SST failed to identify one of the patients as adrenal insufficient. In the seven asymptomatic patients with a subnormal cortisol response to ITT, the diagnosis of adrenal insufficiency was confirmed in one by LDSST, in none by SST, and in five by CRH tests. The five patients with a normal cortisol response to ITT exhibited a normal response also after LDSST and SST. Only two of them had a normal response after a CRH test. In the seven patients with asymptomatic adrenal insufficiency mean morning cortisol concentration was significantly higher than in the patients with overt adrenal insufficiency. ITT was contraindicated in eight patients, and none of them had clinical symptoms of overt adrenal insufficiency. One of these patients had a subnormal cortisol response to LDSST, SST, and CRH, and three exhibited a subnormal response to CRH but normal responses to LDSST and to SST.

Conclusion: We conclude that none of these tests can be considered completely reliable for establishing or excluding the presence of secondary or tertiary adrenal insufficiency. Consequently, clinical judgment remains one of the most important issues for deciding which patients need assessment or re–assessment of adrenal function.
The Large Loop Repair and Mismatch Repair Pathways of Saccharomyces cerevisiae Act on Distinct Substrates During Meiosis
Authors: Jensen Linnea E , Jauert Peter A , Kirkpatrick David T
Published: May 2005

During meiotic recombination in the yeast Saccharomyces cerevisiae, heteroduplex DNA is formed when single-stranded DNAs from two homologs anneal as a consequence of strand invasion. If the two DNA strands differ in sequence, a mismatch will be generated. Mismatches in heteroduplex DNA are recognized and repaired efficiently by meiotic DNA mismatch repair systems. Components of two meiotic systems, mismatch repair (MMR) and large loop repair (LLR), have been identified previously, but the substrate range of these repair systems has never been defined. To determine the substrates for the MMR and LLR repair pathways, we constructed insertion mutations at HIS4 that form loops of varying sizes when complexed with wild-type HIS4 sequence during meiotic heteroduplex DNA formation. We compared the frequency of repair during meiosis in wild-type diploids and in diploids lacking components of either MMR or LLR. We find that the LLR pathway does not act on single-stranded DNA loops of <16 nucleotides in length. We also find that the MMR pathway can act on loops up to 17, but not >19, nucleotides in length, indicating that the two pathways overlap slightly in their substrate range during meiosis. Our data reveal differences in mitotic and meiotic MMR and LLR; these may be due to alterations in the functioning of each complex or result from subtle sequence context influences on repair of the various mismatches examined.
The Genetic Basis of Resistance to Anticoagulants in Rodents
Authors: Pelz Hans-Joachim , Rost Simone , Hünerberg Mirja , Fregin Andreas , Heiberg Ann-Charlotte , Baert Kristof , MacNicoll Alan D , Prescott Colin V , Walker Anne-Sophie , Oldenburg Johannes , Müller Clemens R
Published: May 2005

Anticoagulant compounds, i.e., derivatives of either 4-hydroxycoumarin (e.g., warfarin, bromadiolone) or indane-1,3-dione (e.g., diphacinone, chlorophacinone), have been in worldwide use as rodenticides for >50 years. These compounds inhibit blood coagulation by repression of the vitamin K reductase reaction (VKOR). Anticoagulant-resistant rodent populations have been reported from many countries and pose a considerable problem for pest control. Resistance is transmitted as an autosomal dominant trait although, until recently, the basic genetic mutation was unknown. Here, we report on the identification of eight different mutations in the VKORC1 gene in resistant laboratory strains of brown rats and house mice and in wild-caught brown rats from various locations in Europe with five of these mutations affecting only two amino acids (Tyr139Cys, Tyr139Ser, Tyr139Phe and Leu128Gln, Leu128Ser). By recombinant expression of VKORC1 constructs in HEK293 cells we demonstrate that mutations at Tyr139 confer resistance to warfarin at variable degrees while the other mutations, in addition, dramatically reduce VKOR activity. Our data strongly argue for at least seven independent mutation events in brown rats and two in mice. They suggest that mutations in VKORC1 are the genetic basis of anticoagulant resistance in wild populations of rodents, although the mutations alone do not explain all aspects of resistance that have been reported. We hypothesize that these mutations, apart from generating structural changes in the VKORC1 protein, may induce compensatory mechanisms to maintain blood clotting. Our findings provide the basis for a DNA-based field monitoring of anticoagulant resistance in rodents.
The Origin of Multiple B Mating Specificities in Coprinus cinereus
Authors: Riquelme Meritxell , Challen Michael P , Casselton Lorna A , Brown Andrew J
Published: May 2005

Mushrooms, such as Coprinus cinereus, possess large families of pheromones and G-protein-coupled receptors that are sequestered at the B mating-type locus and whose function is to confer vast numbers of different mating types. This ability results from complex patterns of cognate and noncognate pheromone/receptor pairings, which potentially offer a unique insight into the molecular interaction between receptor and ligand. In this study we have identified many more members of these families by molecular analysis of strains collected worldwide. There are three groups of genes at each B locus. We have identified two alleles of group 1, five alleles of group 2, and seven alleles of group 3, encoding in total 14 different receptors and 29 different pheromones. The specificity of many newly identified alleles was determined by transformation analysis. One striking finding was that receptors fall into groups based on sequence homology but these do not correspond to the groups defined by position, indicating that complex evolutionary processes gave rise to the B loci. While additional allelic versions may occur in nature, the number of B specificities possible by combination of the alleles that we describe is 70, close to previous estimates based on population analysis.
The Molecular Chaperone Sse1 and the Growth Control Protein Kinase Sch9 Collaborate to Regulate Protein Kinase A Activity in Saccharomyces cerevisiae
Authors: Trott Amy , Shaner Lance , Morano Kevin A
Published: May 2005

The Sch9 protein kinase regulates Hsp90-dependent signal transduction activity in the budding yeast Saccharomyces cerevisiae. Hsp90 functions in concert with a number of cochaperones, including the Hsp110 homolog Sse1. In this report, we demonstrate a novel synthetic genetic interaction between SSE1 and SCH9. This interaction was observed specifically during growth at elevated temperature and was suppressed by decreased signaling through the protein kinase A (PKA) signal transduction pathway. Correspondingly, sse1Δ sch9Δ cells were shown by both genetic and biochemical approaches to have abnormally high levels of PKA activity and were less sensitive to modulation of PKA by glucose availability. Growth defects of an sse1Δ mutant were corrected by reducing PKA signaling through overexpression of negative regulators or growth on nonoptimal carbon sources. Hyperactivation of the PKA pathway through expression of a constitutive RAS2 allele likewise resulted in temperature-sensitive growth, suggesting that modulation of PKA activity during thermal stress is required for adaptation and viability. Together these results demonstrate that the Sse1 chaperone and the growth control kinase Sch9 independently contribute to regulation of PKA signaling.
Effects of Nativity, Age at Migration, and Acculturation on Smoking Among Adult Houston Residents of Mexican Descent
Authors: Wilkinson Anna V. , Spitz Margaret R. , Strom Sara S. , Prokhorov Alexander V. , Barcenas Carlos H. , Cao Yumei , Saunders Katherine C. , Bondy Melissa L.
Published: May 2005

Objectives. We investigated differences in smoking behaviors between US-and Mexican-born ever smokers and examined the influence of US culture on smoking initiation.

Methods. Participants were 5030 adults of Mexican descent enrolled in an ongoing population-based cohort in Houston, Tex.

Results. More men than women reported current smoking; rates among US-born women were higher than those among Mexican-born women. Smoking rates among US-born men were higher than earlier published rates among Hispanics and non-Hispanic Whites but similar to rates among African Americans. Current smoking rates among Mexican-born women were lower than published rates for Hispanics, non-Hispanic Whites, and African Americans. Older age, male gender, a higher level of acculturation, more than a high school education, and residing in a census tract with a higher median age predicted history of smoking among US-born participants. Among Mexican-born participants, older age, male gender, a higher level of acculturation, and younger age at migration predicted history of smoking.

Conclusions. Smoking interventions for people of Mexican descent should be tailored according to gender, nativity, and acculturation level and should target all ages, not just young people.
Strain differences in the distribution of NDP‐ase labelled microglia in the normal rabbit retina
Authors: Humphrey Martin F. , Moore Stephen R.
Published: May 2005

Nucleoside diphosphatase (NDP‐ase) labelled microglial cells were examined in retinas of three strains of rabbit, the New Zealand White (albino), the Canberra Half‐Lop, and the Dutch Belted. The distribution in the nerve fibre and inner plexiform layers was similar in all strains. However, the outer plexiform layer (OPL) of Dutch‐Belted rabbits was completely covered with a population of non‐overlapping NDP‐ase positive microglia while the OPL of New Zealand White and Half‐Lop strains contained only occasional isolated cells. In the Dutch‐Belted strain the area covered by the processes of each cell was less in central than peripheral retina where the cell density was lower. In the central retina of the New Zealand White and Half‐Lop strains the cells covered an area similar to that of peripheral Dutch‐Belted cells, suggesting that they were at a low density and there was no hidden population of cells. This finding was confirmed by Griffonia simplicifolia lectin labelling. Therefore the data is consistent with there being a strain variation in OPL microglia. The intensity of NDP‐ase label in the IPL and GCL was less in the New Zealand White and Half‐Lop strains and although the intensity increased after retinal injury it never reached that of the Dutch‐Belted retinas. These variations in the intensity of NDP‐ase expression and the localization of microglial cells may be important in inflammation and also for CNS function. © 1995 Wiley‐Liss, Inc.
TGF‐βs upregulate NCAM and L1 expression in cultured Schwann cells, suppress cyclic AMP–induced expression of O4 and galactocerebroside, and are widely expressed in cells of the Schwann cell lineage in vivo
Authors: Stewart Helen J. S. , Rougon Genevieve , Dong Ziping , Dean Charlotte , Jessen Kristjan R. , Mirsky Rhona
Published: May 2005

We have examined both how the molecular phenotype of Schwann cells in vitro is regulated by transforming growth factor β (TGF‐β), using immunohistochemistry and immunoblotting, and the distribution of TGF‐β2 and 3 in embryonic and mature nerves and ganglia, using immunohistochemistry and in situ hybridisation. We find that TGF‐β2 and ‐3 upregulate expression of the neural cell adhesion molecules NCAM and L1. In TGF‐β‐treated cultures, in addition to the 140 and 120 kD isoforms known to be present in Schwann cells, small amounts of the 180 kD isoform can be detected. TGF‐βs also block cAMP‐induced expression of the lipid antigens galactocerebroside (GalC) and O4, in addition to blocking expression of protein zero (P0), the major peripheral myelin glycoprotein, as previously shown.

Using antibodies specific to TGF‐β2 and −3, respectively, we confirm the presence of these proteins in myelin‐forming Schwann cells and show also that TGF‐β2 and −3 are clearly expressed by peripheral glia that are not involved in myelination. This includes Schwann cell precursors, embryonic Schwann cells, non‐myelin‐forming Schwann cells and satellite cells from adult nerves and ganglia, and neonatal Schwann cells in purified cultures without neurones. In situ hybridisation with a digoxygenin‐labelled riboprobe reveals a strong TGF‐β3 mRNA signal in Schwann cells, satellite cells, and some neurones. Schwann cells in culture also secrete TGF‐β in a latent form, whereas purified cultures of dorsal root ganglion neurones from 1‐day‐old rats secrete active TGFß during the first 48 h in culture. © 1995 Wiley‐Liss, Inc.
Cytotoxic T cells are preferentially activated in the duodenal epithelium from patients with florid coeliac disease
Authors: Buri Caroline , Burri Philipp , Bähler Peter , Straumann Alex , Müller‐Schenker Beatrice , Birrer Stefan , Mueller Christoph
Published: May 2005

Villous atrophy and increased numbers of intraepithelial T cells in duodenal biopsies represent a hallmark of coeliac disease. In the present study, an attempt has been made to define whether cytotoxic cell subsets are activated in situ in the affected mucosa of susceptible individuals early after ingestion of a gluten‐containing diet. Duodenal biopsies from 11 patients with coeliac disease who repeatedly underwent endoscopic biopsy after ingestion of individually dosed amounts of gluten were used for immunohistochemistry and in situ hybridization. To identify the cell subsets expressing perforin mRNA and protein, in situ hybridization and FACS analyses were performed on cells isolated from fresh biopsies. Compared with normal mucosa, the number of intraepithelial lymphocytes containing perforin mRNA and protein increased significantly in tissue samples showing moderate or florid coeliac disease and closely paralleled the severity of morphological alteration, whereas the frequency of perforin‐expressing lamina propria lymphocytes increased only moderately. Cells isolated from florid biopsies that expressed perforin mRNA and protein were preferentially T‐cell receptor (TCR) αβ T cells. The increase in both the absolute number and the percentage of lymphocytes expressing perforin mRNA indicates in situ activation of lymphocytes within the epithelial compartment in florid coeliac disease upon ingestion of a gluten‐containing diet in patients predisposed to coeliac disease. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Chondromyxoid fibroma resembles in vitro chondrogenesis, but differs in expression of signalling molecules
Authors: Romeo Salvatore , Bovée Judith VMG , Grogan Shawn P , Taminiau Antonie HM , Eilers Paul HC , Cleton‐Jansen Anne Marie , Mainil‐Varlet Pierre , Hogendoorn Pancras CW
Published: May 2005

Chondromyxoid fibroma is a rare benign cartilaginous bone tumour characterized by morphological features that resemble different steps of chondrogenesis in terms of both cellular morphology, ranging from spindled to rounded cells, and the extracellular matrix formed, which ranges from fibrous to cartilaginous. The presence in chondromyxoid fibroma of signalling molecules that regulate the spatial expression of proteins involved in normal cartilage proliferation and differentiation was investigated in samples from 20 patients and compared with articular chondrocytes from 11 normal donors cultivated in 3D pellet culture. Sections were stained with safranin‐O and H&E, and immunohistochemistry was performed for p16, cyclin D1, FGFR3, BCL2, p21, PTHLH, PTHR1 and N‐cadherin. Expression patterns were analysed using hierarchical clustering. In chondromyxoid fibroma, specific morphological features correlated with a distinct pattern of expression. Comparison with normal chondrocytes in pellet culture showed a striking morphological resemblance, but with an unmistakably different pattern of expression. N‐cadherin, PTHLH, and PTHR1 were expressed to a significantly higher level (p < 0.01) in articular chondrocyte pellets but, conversely, there was significantly lower expression of cyclin D1, p16 and BCL2 (p < 0.05) in these cells. Morphological similarities reflect common steps in cartilage differentiation, albeit driven by different molecular mechanisms. The proteins we have found to be differentially expressed seem crucial for neoplastic chondrogenesis. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Safety and Effectiveness of Left Hepatic Trisegmentectomy for Hilar Cholangiocarcinoma
Authors: Shimada Kazuaki , Sano Tsuyoshi , Sakamoto Yoshihiro , Kosuge Tomoo
Published: May 2005

Left hepatic trisegmentectomy has been performed for huge malignant tumors, but it is rarely applied in patients with hilar cholangiocarcinoma. Twelve consecutive patients (7 men and 5 women; mean age, 64 years) underwent left hepatic trisegmentectomy in our institution between January 2000 and December 2003. The preoperative management and postoperative outcomes of this surgical procedure were presented and retrospectively analyzed. Preoperative biliary drainage and portal vein embolization were performed in 6 patients (50%) and 9 patients (75%), respectively. The preoperative estimated volume ratio of the posterior segment /the whole liver was 44.8 ± 7.0% (34.3–54.3), the plasma retention rate of indocyanine green at 15 minutes was 8.6 ± 2.2% (4.7–13.7), and the serum total bilirubin level before surgery was 1.0 ± 0.4 mg/dl (0.4–1.7). The serum total bilirubin level on the first postoperative day was 3.3 ± 0.4 mg/dl (1.4–6.2). There was no hospital death or postoperative hepatic failure. The incidence of positive resectional margin was 25%. With biliary decompression and preoperative portal embolization techniques, left hepatic trisegmentectomy was a safe and curative resectional option for hilar cholangiocarcinoma.
Malignant Metastatic Insulinoma—Postoperative Treatment and Follow‐up
Authors: Starke Achim , Saddig Christiane , Mansfeld Lothar , Koester Rainer , Tschahargane Cyrus , Czygan Peter , Goretzki Peter
Published: May 2005

The rarity of malignant insulinoma limits reports on therapeutic strategies and outcome. The treatment and follow‐up of 10 patients, all presenting an insulinoma with metastatic disease of the liver and newly diagnosed between 1992 and 2002, is reported. Pancreatic surgery with successful removal of the primary tumor preferentially located in the tail was performed in 7 women and 3 men, median age 55 years (range 36–82 years). If appropriate, 5 patients underwent additional hepatic surgery and lymph node resections. Liver metastases as the major cause of postoperatively persistent hypoglycemia were subsequently treated by repeated transarterial hepatic chemoembolization and chemoperfusion protocols using high‐dose transhepatic streptozocin perfusions (3–4 g per session). The current median survival time for all 10 patients is 2.6 years (range: 1.6–9.7 years). Six patients are currently alive with a median survival of 3.7 years (1.7–9.7 years), five of them with stable disease and free of hypoglycemia. Four patients died after a median survival of 1.8 years (range: 1.6–7.5 years) from complications of unmanageable hypoglycemia. It is concluded that the necessity to treat debiliating and life‐threatening hypoglycemia in metastatic malignant insulinoma warrants the option of radical endocrine surgery in combination with extended and repeated postoperative chemoembolization of liver metastases.
Indication of Hepatectomy for Cirrhotic Patients with Hepatocellular Carcinoma Classified as Child‐Pugh Class B
Authors: Nakahara Hideki , Itamoto Toshiyuki , Katayama Koji , Ohdan Hideki , Hino Hiroshi , Ochi Makoto , Tashiro Hirotaka , Asahara Toshimasa
Published: May 2005

We clarified the indication of partial hepatectomy in hepatocellular carcinoma (HCC) patients with liver cirrhosis classified as Child‐Pugh class B. Univariate analysis revealed that adverse prognostic factors were (1) the presence of ascites, (2) elevated total bilirubin (1.5 mg/dl or higher), (3) reduced choline esterase (160 IU/ or lower), (4) elevated alpha‐fetoprotein (AFP) (400 ng/ml or higher), (5) microscopic vascular invasion, and (6) non‐curative hepatectomy. Microvascular invasion was excluded in the multivariate analysis because this factor could not be predicted before hepatectomy. Multivariate analysis revealed that independent adverse prognostic factors were (1) elevated total bilirubin (1.5 mg/dl or higher), (2) presence of ascites, (3) elevated AFP (400 ng/ml or higher), and (4) non‐curative hepatectomy. The overall 5‐year survival rate of patients with none of or only one of the four adverse prognostic factors was 45.8%. The overall 5‐year survival rate of patients with two or more adverse prognostic factors was only 7.0%. Partial hepatectomy is the first choice of treatment for patients with none of or only one of the four adverse prognostic factors, whereas orthotopic liver transplantation or other conservative treatment should be considered for patients with two or more adverse prognostic factors.
Eleven Years of Liver Trauma: The Scottish Experience
Authors: Scollay John M. , Beard Diana , Smith Rik , McKeown Dermot , Garden O. James , Parks Rowan
Published: May 2005

The aim of this population based study was to assess the incidence, mechanisms, management, and outcome of patients who sustained hepatic trauma in Scotland (population 5 million) over the period 1992–2002. The Scottish Trauma Audit Group database was searched for details of any patient with liver trauma. Data on identified patients were analyzed for demographic information, mechanisms of injury, associated injuries, hemodynamic stability on presentation, management, and outcome. A total of 783 patients were identified as having sustained liver trauma. The male‐to‐female ratio was 3:1 with a median age of 31 years. Blunt trauma (especially road traffic accidents) accounted for 69% of injuries. Liver trauma was associated with injuries to the chest, head, and abdominal injuries other than liver injury; most commonly spleen and kidneys. In all, 166 patients died in the emergency department, and a further 164 died in hospital. The mortality rate was higher in patients with increasing age (p < 0.001), hemodynamic instability (p < 0.001), blunt trauma (p < 0.001), and increasing severity of liver injury (p < 0.001). The incidence of liver trauma in Scotland is low, but it accounts for significant mortality. Associated injuries were common. Outcome was worse in patients with advanced age, blunt trauma, multiple injuries and those requiring an immediate laparotomy.
Protein C as an Early Marker of Severe Septic Complications in Diffuse Secondary Peritonitis
Authors: Karamarkovic Aleksandar , Radenkovic Dejan , Milic Natasa , Bumbasirevic Vesna , Stefanovic Branislav
Published: May 2005

To evaluate the predictive value of protein C as a marker of severity in patients with diffuse peritonitis and abdominal sepsis, protein C levels were repeatedly determined and compared with serum levels of antithrombin III, plasminogen, α2‐antiplasmin, Plasminogen activator inhibitor, D‐dimer, C1‐inhibitor, high molecular weight kininogen, and the C5a, C5b‐9 fragments of the complement system. We carried out a prospective study from 44 patients with severe peritonitis confirmed by laparotomy and 15 patients undergoing elective ventral hernia repair who acted as controls. Analyzed biochemical parameters were determined before operations and on days 1, 2, 3, 5, 7, 10, and 14 after operations. For the study group, preoperative average protein C level was significantly lower in the patients who developed septic shock in the late course of the disease, with lethal outcome, than in the patients with severe peritonitis and sepsis who survived (p = 0.0001). In non‐survivors, protein C activity remained decreased below 70%, whereas the course of survivors was characterized by increased values that were significantly higher (p < 0.03) at every time point than in those patients who died. Protein C was of excellent predictive value and achieved a sensitivity of 80% and a specificity of 87.5% in discriminating survivors from non‐survivors within the first 48 hours of the study (AUC‐0.917; p < 0.001), with a “cut‐off” level of 66.0%. As for the control group, throughout the study period, protein C activity was permanently maintained within the range of normal, with significant differences with reference to the study group (p < 0.01). These results suggest that protein C represents a sensitive and early marker for the prediction of severe septic complications during diffuse peritonitis, and of outcome.
The Effects of Cetrimide–Chlorhexidine Combination on the Hepato‐Pancreatico‐Biliary System
Authors: Tozar Elvan , Topcu Omer , Karayalcin Kaan , Akbay Serap Ilhan , Hengirmen Suleyman
Published: May 2005

Sclerosing cholangitis is a rare but dreadful complication of liver hydatid surgery. Almost all scolocidal agents are associated clinically or experimentally with this complication. Cetrimide–chlorhexidine combination is the most potent scolocidal agent, and this study was designed to examine its effect on the hepato‐pancreatico‐biliary system. Forty Wistar‐albino rats were divided into two groups. 0.5% cetrimide–0.05% chlorhexidine was injected into the biliary tract of study group animals and 0.9% saline ( NaCl ) into the control group through a 3‐mm duodenotomy. The animals were sacrificed after 90 days and histopathological examination of the liver, biliary tract, and pancreas was performed 90 days after the biliary injection. The histopathological examination showed that the lesions ranged from focal necrosis to sclerosing cholangitis to liver cirrhosis. Focal necrosis and eosinophilic inflammation were observed in all rats in the study group. The changes in the liver, biliary tract, and pancreas of the study group animals were significantly more severe than those in the control group (p < 0.05). This experimental study confirms the deleterious effect of another scolocidal agents on the hepato‐pancreatico‐biliary system. Although it is a very effective scolocidal agent, it should not be used in the presence of a duct biliary–cyst communication.
Young people, drug use and family conflict: Pathways into homelessness
Authors: Mallett Shelley , Rosenthal Doreen , Keys Deborah
Published: May 2005

Young people who experience homelessness, in Australia and in other western contexts (US, Canada, England), are widely perceived to use and abuse alcohol and drugs. The available research indicates that homeless young people use all drug types, whether injected or otherwise, more frequently than their home‐based peers. Debate exists in the research and policy literature about whether drug use is a cause or consequence of homelessness. In a study exploring homeless young peoples reasons for leaving home, we examined the relationship between young people's drug use and their pathways into homelessness. Brief qualitative interviews were conducted with 302 homeless young people (12–20 years). Following a thematic analysis of interview transcripts, four pathways into homelessness involving personal or familial drug use were identified. One‐third of the participants indicated that personal or familial drug use was a critical factor in them leaving home. Of these, just over half indicated that personal drug use was a direct or indirect cause of their homelessness and one‐quarter indicated that familial drug and alcohol use was the critical factor that led them to leaving home. One‐quarter indicated that their drug use only began after they became homeless. Family conflict, if not family breakdown, was implicated in all four pathways out of home.