bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and kinematics along a segment of the Mojave‐Sonora megashear: A strike‐slip fault that truncates the Jurassic continental magmatic arc of southwestern North America
Authors: Campbell Patricia A. , Anderson Thomas H.
Published: December 2003

Similarities between crystalline crust and overlying pre‐Jurassic cover in northwestern Sonora, Mexico, and in the Inyo Mountains‐Death Valley region, California, are attributed to left‐lateral displacement along the Mojave‐Sonora megashear, a Late Jurassic transform fault related to the opening of the Gulf of Mexico. Three exposures of mylonitic rocks extending 25 km along the postulated fault occur within Sierra de Los Tanques, Sonora, Mexico. The exposures 13 km southwest of Sonoita reveal a tripartite assemblage of (1) Jurassic volcanic and volcaniclastic strata to the northeast, (2) an axial zone of mylonitic rocks, and (3) masses of granitic rocks and compositionally banded quartzo‐feldspathic gneiss of Proterozoic (?) and Late Triassic age to the southwest. Mylonitic foliation in rocks within the axial zone strikes northwesterly, and lineations plunge shallowly. Microstructues record left‐lateral shear. Shallow thrusts, folded mylonite, and steeply dipping mylonitic foliation with downdip mineral lineation record transpression. Triassic and Precambrian crystalline rocks are emplaced above shallow thrusts onto ductilly deformed Jurassic rocks northeast of the principal fault. In the central and northwestern exposures, pervasively foliated and lineated rocks are cut by weakly foliated Cretaceous granite that also may contain inclusions of mylonite. The northwesterly strike of steep foliation, left‐lateral kinematics, and relationships with Cretaceous intrusive rocks preclude correlation with episodes of Cretaceous contraction and Tertiary extension that are recognized in the southwestern United States. The fault is interpreted to have formed in the Late Jurassic and records a change in tectonic setting from arc magmatism to rifting and basin development.
Testing and parameterizing a conceptual model for solute transport in a fractured granite using multiple tracers in a forced‐gradient test
Authors: Reimus Paul , Pohll Greg , Mihevc Todd , Chapman Jenny , Haga Marc , Lyles Brad , Kosinski Sean , Niswonger Rich , Sanders Peter
Published: December 2003

A cross‐hole tracer test involving the simultaneous injection of two nonsorbing solute tracers with different diffusion coefficients (bromide and pentafluorobenzoate) and a weakly sorbing solute tracer (lithium ion) was conducted in a fractured granite near an underground nuclear test cavity in central Nevada. The test was conducted to (1) test a conceptual radionuclide transport model for the site and (2) obtain transport parameter estimates for predictive modeling. The differences between the responses of the two nonsorbing tracers (when normalized to injection masses) are consistent with a dual‐porosity transport system in which matrix diffusion is occurring. The large concentration attenuation of the sorbing tracer relative to the nonsorbing tracers suggests that diffusion occurs primarily into matrix pores, not simply into stagnant water within the fractures. The relative responses of the tracers at late times suggest that the diffusion‐accessible matrix pore volume is possibly limited to only half the total volume of the flow system, implying that the effective retardation factor due to matrix diffusion may be as small as 1.5 for nonsorbing solutes in the system. The lower end of the range of possible sorption Kd values deduced from the lithium response is greater than the upper 95% confidence bound of Kd values measured in laboratory sorption tests using crushed granite from the site. This result suggests that the practice of using laboratory sorption data in field‐scale transport predictions of cation‐exchanging radionuclides, such as 137Cs+ and 90Sr++, should be conservative for the SHOAL site.
Analysis of the duration, seasonal timing, and location of North Atlantic tropical cyclones: 1950–2002
Authors: Balling Robert C. , Cerveny Randall S.
Published: December 2003

Many scientists have suggested that a warmer world with elevated atmospheric moisture levels could increase the frequency, intensity, or duration of future tropical cyclones or alter their mean locations. While others have examined historical patterns in tropical cyclone frequency and intensity, and generally found no trends in recent decades, we analyzed tropical cyclone records from the Caribbean, Gulf of Mexico, and tropical sector of the western North Atlantic over the period 1950–2002 with a focus on the duration, seasonal timing, and geographic position of the events. We found no significant trends in the start date, ending date, or duration of the storm season (defined in various ways) and no trends in the average geographic position of the storms. Furthermore, these measures of hurricane season timing and storm locations were not related to regional sea surface temperature or the northern hemispheric or global temperatures.
Breaking of thunderstorm‐generated gravity waves as a source of short‐period ducted waves at mesopause altitudes
Authors: Snively Jonathan B. , Pasko Victor P.
Published: December 2003

Numerical simulation results indicate that the breaking of atmospheric gravity waves generated by tropospheric convection can excite short‐period secondary waves, which are trapped in the lower thermospheric duct and which closely resemble quasi‐monochromatic structures commonly observed in airglow imaging experiments.
Anomalous resistivity in non‐Maxwellian plasmas
Authors: Petkaki P. , Watt C. E. J. , Horne R. B. , Freeman M. P.
Published: December 2003

Vlasov simulations of the current‐driven ion‐acoustic instability produced in Maxwellian and non‐Maxwellian (Lorentzian, κ = 2) electron‐ion plasma with number density 7 × 106 cm−3, reduced mass ratio mi/me = 25, and electron to ion temperature ratio Te/Ti = 1 are presented and compared. A concise stability analysis of current‐driven ion‐acoustic waves in Maxwellian and non‐Maxwellian plasmas modeled by generalized Lorentzian distribution function with index 2 ≤ κ ≤ 7 and electron to ion temperature ratio 1 ≤ Te/Ti ≤ 100 is also presented. The ion‐acoustic instability is excited in low temperature ratio Lorentzian (κ = 2) plasma for lower absolute electron drift velocity (up to half the critical electron drift velocity of a Maxwellian). The anomalous resistivity resulting from ion acoustic waves in a Lorentzian plasma is a strong function of the electron drift velocity and in the work presented here varies by a factor of ∼100 for a 1.5 increase in the electron drift velocity. Furthermore, ion‐acoustic anomalous resistivity is excited for electron drift velocities that would be stable for Maxwellian plasmas. The magnitude of resistivity which can be generated by unstable ion‐acoustic waves may be important for magnetic reconnection at the magnetopause.
Seismic structure of Cocos and Malpelo Volcanic Ridges and implications for hot spot‐ridge interaction
Authors: Sallarès Valentí , Charvis Philippe , Flueh Ernst R. , Bialas Joerg
Published: December 2003

The Cocos and Malpelo Volcanic Ridges are blocks of thickened oceanic crust thought to be the result of the interaction between the Galapagos hot spot and the Cocos‐Nazca Spreading Center during the last 20 m.y. In this work we investigate the seismic structure of these two aseismic ridges along three wide‐angle transects acquired during the Panama basin and Galapagos plume—New Investigations of Intraplate magmatism (PAGANINI)‐1999 experiment. A two‐dimensional velocity field with the Moho geometry is obtained using joint refraction/reflection travel time tomography, and the uncertainty and robustness of the results are estimated by performing a Monte Carlo‐type analysis. Our results show that the maximum crustal thickness along these profiles ranges from ∼16.5 km (southern Cocos) to ∼19 km (northern Cocos and Malpelo). Oceanic layer 2 thickness is quite uniform regardless of total crustal thickness variations; crustal thickening is mainly accommodated by layer 3. These observations are shown to be consistent with gravity data. The variation of layer 3 velocities is similar along all profiles, being lower where crust is thicker. This leads to an overall anticorrelation between crustal thickness and bulk lower crustal velocity. Since this anticorrelation is contrary to crustal thickening resulting from passive upwelling of abnormally hot mantle, it is necessary to consider active upwelling components and/or some compositional heterogeneities in the mantle source. The NW limit of the Malpelo Ridge shows a dramatic crustal thinning and displays high lower crustal velocities and a poorly defined crust‐mantle boundary, suggesting that differential motion along the Coiba transform fault probably separated Regina and Malpelo Ridges.
Simulation of transport in three‐dimensional heterogeneous unsaturated soils with upscaled dispersion coefficients
Authors: Russo David
Published: December 2003

Numerical simulations of solute transport under unsaturated flow conditions were employed in order to test the capability of the upscaling methodology that Dagan developed for steady state, saturated flow and that Russo adapted to steady state, unsaturated flow to compensate for the loss of subgrid variations of the velocity field caused by coarse discretization of the flow domain. The results suggest that under relatively simple, steady state, gravity‐dominated flows and for soils of differing textures the basic requirement for the upscaling of the dispersion coefficients is fulfilled and that the upscaling methodology essentially compensated for the loss of subgrid variations of the velocity field. For both soils these desirable results were achieved with a relatively coarse grid, which in turn, reduced the number of numerical cells by 96% compared with the fine‐grid discretization of the flow domain. The applicability of the upscaling methodology to more general situations involving complex, transient flow regimes originating from periodic rain/irrigation events and water uptake by plant roots was also analyzed. The results of these analyses suggested that under transient flow conditions, in the absence of water uptake by plant roots, the basic requirement for the upscaling of the dispersion coefficients was fulfilled within numerical errors and the upscaling methodology essentially compensated for the loss of subgrid variations of the velocity field. On the other hand, in the case of water uptake by plant roots the failure of the numerical solution of the flow equation over coarse‐grid cells to reproduce the actual complex flow pattern in the root zone prevented the fulfillment of three out of the four equalities which comprise the basic requirement for the upscaling of the dispersion coefficients. Nevertheless, even in this complicated case, the upscaling methodology essentially compensated for the loss of subgrid‐scale variations of the velocity field caused by coarse discretization of the flow domain.
Modeling sub‐grid‐block‐scale dense nonaqueous phase liquid (DNAPL) pool dissolution using a dual‐domain approach
Authors: Falta Ronald W.
Published: December 2003

A dual‐domain approach is developed for calculating the advective and dispersive mass flux of chemical leaving one or more sub‐grid‐block‐scale DNAPL pool(s) in an integral finite difference numerical simulation. The contaminated zone in a simulation is divided into two fractions: one that contains DNAPL pools and one in which DNAPL is not present. With a dual‐permeability formulation the two regions may have the same or different flow properties depending on the conceptual model for pool formation, and fluids can freely flow through both domains. The local dispersive flux of contaminant away from the DNAPL pool is calculated using a well‐known analytical solution for steady state advection and dispersion. This expression is integrated analytically to give a first‐order mass transfer relationship for the total dissolution rate inside a grid block as a function of the horizontal water velocity, the transverse dispersivity, the DNAPL solubility, and the dissolved concentration in the media not containing the DNAPL. The calculated interphase mass transfer rate using a single dual‐domain integral finite difference grid block is shown to match experimental data and an analytical solution for DNAPL pool dissolution.
Implications of halide leaching on 36Cl studies at Yucca Mountain, Nevada
Authors: Lu Guoping , Sonnenthal Eric L. , Bodvarsson Gudmundur S.
Published: December 2003

Chlorine 36 was generated from nuclear tests in the 1950s and 1960s and has been used to identify fast flow paths at Yucca Mountain, the proposed repository for high‐level nuclear waste [Fabryka‐Martin et al., 1997, 1998]. Bomb pulse 36Cl, brought into the subsurface by infiltrating rainwater, presumably resides along fracture surfaces because of the extremely low rock matrix permeability. However, leaching a rock sample to extract this salt inevitably extracts pore water chloride (Cl) and rock matrix chloride, thereby making it difficult to obtain reproducible measurements or detect the specific bomb pulse signatures. Complexities introduced by these sources of older chloride include dilution of bomb pulse 36Cl/Cl ratios for samples from strata with a high Cl concentration, variations in measured ratios as a function of leaching time, rock chip size, and the differing effects of active leaching from those of passive leaching. This work provides both a conceptual model and a mathematical solution for the leaching processes and examines the role of sample leaching in the 36Cl studies of Yucca Mountain rocks. An analytical solution is derived for the diffusion of Cl and 36Cl in composite media (rock matrix and water) to accommodate variable diffusivity. This solution is subsequently used to develop a leaching model that takes into account bomb pulse signal, matrix pore water, and relatively hard to leach components (isolated fluid inclusion and mineral boundary salts). The model is then applied to samples from stratigraphic units at Yucca Mountain to obtain leachate concentrations from different setup methods (protocols), including duration, chip size, and gravitational settling of the water‐rock mixture. The model results show that the probability of detecting a 36Cl/Cl bomb pulse signal is severely diminished under longer leaching times and smaller rock fragment sizes and that leaching times of 1 to 10 hours are most likely to be successful in detecting a bomb pulse signal. Bomb pulse 36Cl/Cl ratios are more likely to be observed if pore water Cl concentrations were initially low prior to the introduction of bomb pulse carrying water.
Infiltration from surface and buried point sources: The Average wetting water content
Authors: Cook F. J. , Thorburn P. J. , Bristow K. L. , Cote C. M.
Published: December 2003

The assumption in analytical solutions for flow from surface and buried point sources of an average water content, , behind the wetting front is examined. Some recent work has shown that this assumption fitted some field data well. Here we calculated using a steady state solution based on the work by Raats [1971] and an exponential dependence of the diffusivity upon the water content. This is compared with a constant value of calculated from an assumption of a hydraulic conductivity at the wetting front of 1 mm day−1 and the water content at saturation. This comparison was made for a wide range of soils. The constant generally underestimated at small wetted radii and overestimated at large radii. The crossover point between under and overestimation changed with both soil properties and flow rate. The largest variance occurred for coarser texture soils at low‐flow rates. At high‐flow rates in finer‐textured soils the use of a constant results in underestimation of the time for the wetting front to reach a particular radius. The value of is related to the time at which the wetting front reaches a given radius. In coarse‐textured soils the use of a constant value of can result in an error of the time when the wetting front reaches a particular radius, as large as 80% at low‐flow rates and large radii.
Novel member of the mouse desmoglein gene family: Dsg1‐β
Authors: Pulkkinen L. , Choi Y.W. , Kljuic A. , Uitto J. , Mahoney M. G.
Published: December 2003

Abstract: Desmosomes are major intercellular adhesion junctions that provide stable cell–cell contacts and mechanical strength to epithelial tissues by anchoring cytokeratin intermediate filaments of adjacent cells. Desmogleins (Dsg) are transmembrane core components of the desmosomes, and belong to the cadherin supergene family of calcium‐dependent adhesion molecules. Currently, there are three known isoforms of Dsgs (Dsg1, Dsg2, and Dsg3), encoded by distinct genes that are differentially expressed to determine their tissue specificity and differentiation state of epithelial cells. In this study, we cloned a novel mouse desmoglein gene sharing high homology to both mouse and human Dsg1. We propose to designate the previously published mouse Dsg1 gene as Dsg1‐α and the new gene as Dsg1‐β. Analysis of intron/exon organization of the Dsg1‐α and Dsg1‐β genes revealed significant conservation. The full‐length mouse Dsg1‐β cDNA contains an open reading frame of 3180 bp encoding a precursor protein of 1060 amino acids. Dsg1‐β protein shares 94% and 76% identity with mouse Dsg1‐α and human DSG1, respectively. RT‐PCR using a multitissue cDNA panel demonstrated that while Dsg1‐α mRNA was expressed in 15‐ to 17‐day‐old embryos and adult spleen and testis, Dsg1‐β mRNA was detected in 17‐day‐old embryos only. To assess subcellular localization, a FLAG‐tagged expression construct of Dsg1‐β was transiently expressed in epithelial HaCaT cells. Dsg1‐β‐FLAG was found at the cell–cell border and was recognized by the anti‐Dsg1/Dsg2 antibody DG3.10. In summary, we have cloned and characterized a novel member of the mouse desmoglein gene family, Dsg1‐β.
A novel mouse desmosomal cadherin family member, desmoglein 1γ
Authors: Kljuic A. , Christiano A. M.
Published: December 2003

Abstract: The mouse desmogleins are members of the desmosomal cadherin superfamily, and are critical structural components of the desmosome. The genes encoding mouse desmogleins are tightly clustered within 600 kb of chromosome 18, within a desmosomal cadherin gene family also containing the three desmocollin genes. In this study, we have characterized a novel mouse desmoglein gene, highly homologous to both mouse and human Dsg1, designated desmoglein 1γ (Dsg1c). Dsg1γ shares 83% amino acid identity to the previously described mouse Dsg1, now designated as Dsg1α, and 32% and 40% identity to mouse Dsg2 and 3, respectively. The Dsg1γ gene maps within the desmosomal gene cluster, between Dsc1 and Dsg1α. Comparison of its exon–intron structure revealed a high level of evolutionary conservation with related family members. In contrast to Dsg1α and Dsg3 whose expression is largely restricted to the skin, Dsg1γ is also expressed in the brain, skeletal muscle, and liver, among other tissues, and is thus more similar to Dsg2 in its tissue distribution. Interestingly, an orthologous Dsg1γ was not found in the human genome, suggesting that the desmosomal cadherin gene cluster contracted during mammalian evolution.
Development of spliceosome‐mediated RNA trans‐splicing (SMaRT™) for the correction of inherited skin diseases
Authors: Dallinger G. , Puttaraju M. , Mitchell L. G. , Yancey K. B. , Yee C. , Klausegger A. , Hintner H. , Bauer J. W.
Published: December 2003

Abstract: Gene therapy of large genes (e.g. plectin and collagen genes) is hampered by size limitations for insertions of the currently used viral vectors. To reduce the size of these insertions spliceosome‐mediated RNA trans‐splicing (SMaRT™), which provides intron‐specific gene‐correction at the pre‐RNA level, can be an alternative approach. To test its applicability in skin gene therapy, SMaRT™ was used in the context of the 4003delTC mutation in the collagen XVII gene (COL17A1) causing generalized atrophic benign junctional epidermolysis bullosa. A β‐galactosidase (β‐gal) trans‐splicing assay system was established using intron 51 of COL17A1 as the target for trans‐splicing. In this system, intron 51 is flanked by the 5′exon and the 3′exon of the β‐gal gene, the latter containing two in‐frame stop codons. Cotransfection of a pre‐trans‐splicing molecule consisting of the binding domain of intron 51 and the 3′exon of β‐gal without the stop codons resulted in a 300‐fold increase of β‐gal activity compared to controls. A 2–3‐fold increase in efficiency was obtained through an elongation of the binding domains. Replacement of the complete 3′end of the COL17A1 gene was shown using a collagen XVII mini‐gene construct. The β‐gal assay was used in human keratinocytes to evaluate the influence of a keratinocyte‐specific spliceosome background. Reverse transcription polymerase chain reaction and β‐gal activity assay showed functional correction of the stop‐codons in cultured human keratinocytes and in an immortalized GABEB cell line harbouring the 4003delTC mutation. These results demonstrate that SMaRT™ is feasible in a keratinocyte‐specific context and therefore may be applied in skin gene therapy.
Detection and quantification of cocaine metabolites in urine samples from horses administered cocaine
Authors: Kollias‐Baker C. , Maxwell L. , Stanley S. , Boone T.
Published: December 2003

Cocaine is a naturally occurring alkaloid that is commonly abused by human‐beings for its psychostimulatory effects. Occasionally, very small concentrations (i.e. <100 ng/mL) of the primary cocaine metabolite, benzoylecgonine (BZE) have been detected in urine collected from horses competing in athletic events. In this study urine samples, collected from four horses following the administration of 2.5 and 20 mg of cocaine sublingually and 50 mg of cocaine intravenously, were analyzed for the presence of cocaine and/or its metabolites by enzyme‐linked immunosorbent assay (ELISA) and gas chromatography–mass spectrometry (GC–MS). The results of ELISA analysis of urine samples collected from all four horses suggested the presence of cocaine and/or its metabolites up to 10, 48, and 72 h after administration of 2.5, 20, and 50 mg of cocaine, respectively. The results of GC–MS analysis confirmed the presence of BZE above the limit of quantification (LOQ = 5 ng/mL) in urine samples collected from all four horses for up to 24 h after administration of 2.5 mg of cocaine and for up to 48 h after administration of 20 and 50 mg of cocaine. No obvious behavioral effects or overt alterations of heart rate or rhythm were noted in any of these horses after cocaine administration.
Myocardial ischemia in a patient with acute lymphoblastic leukemia during l‐asparaginase therapy
Authors: Saviola Alessia , Luppi Mario , Potenza Leonardo , Morselli Monica , Bresciani Paola , Ferrari Angela , Riva Giovanni , Torelli Giuseppe
Published: December 2003

Haemostatic abnormalities may occur in 1–2% of patients treated with l‐asparaginase. Here, we present the second case of a myocardial infarction, developing in a patient with acute lymphoblastic leukemia (ALL), in the course of l‐asparaginase treatment. In our patient and in the only one reported case from the literature, a recent exposure to vincristine and daunorubicin was also reported, but induction chemotherapy program was completed as scheduled, with the only withdrawal of l‐asparaginase. Myocardial infarction should be included in the list of thrombotic complications possibly associated with l‐asparaginase treatment, or with a combination of l‐asparaginase and vinca alkaloids/anthracycline.
Long‐term follow up of patients with multiple myeloma after high‐dose chemotherapy and allogeneic stem cell transplantation
Authors: Rabitsch Werner , Prinz Erika , Ackermann Jutta , Wöhrer Stefan , Kaufmann Hannes , Seidl Sonja , Keil Felix , Kalhs Peter , Greinix Hildegard , Gisslinger Heinz , Leitner Gerda , Drach Johannes
Published: December 2003

Objectives:  Allogeneic transplantation may offer a curative approach to multiple myeloma (MM). We retrospectively analyzed the outcome of patients with multiple myeloma undergoing allogeneic stem celltransplantation in the context of ß2 microglobulin and chromosome 13q.

Methods:  All 13 patients with MM, who were referred to our center for allogeneic stem cell transplantation, were evaluated. Median age of patients was 38 yr, eight patients had chemo‐sensitive disease, and median time between diagnosis of MM and transplantation was 15 months. Engraftment, acute and chronic graft vs. host disease, response to treatment, disease‐free survival, and overall survival were evaluated according to standard criteria.

Results:  There was one transplant‐related death. Among 12 evaluable patients, seven patients (58%) achieved a complete remission (CR), and four patients (33%) achieved a partial remission. Acute graft vs. host disease occurred in 46% of patients, and chronic graft vs. host disease in 42% of available patients. After a median follow‐up of 69.5 months (range, 5–128) nine patients (70%) are still allive, and six of them have remained progression free. Among five patients with low ß2 microglobulin and normal chromosome 13q, four patients achieved a CR, with CR duration >5 yr in three of them. Among seven patients with elevated ß2 microglobulin and/or deletion of chromosome 13q, only three CR were observed, with two patients still in CR on days +920 and +161, respectively.

Conclusions:  Allogeneic stem cell transplantation in patients with MM results in promising rates of CR, but durable remissions are predominantly seen in patients with favorable prognostic parameters.
Treatment of refractory chronic lymphocytic leukemia with Campath‐1H in combination with lamivudine in chronic hepatitis B infection
Authors: Heider Ulrike , Fleissner Claudia , Zavrski Ivana , Jakob Christian , Dietzel Toralf , Eucker Jan , Ockenga Johann , Possinger Kurt , Sezer Orhan
Published: December 2003

Campath‐1H, a monoclonal antibody against human CD52, is used for the therapy of refractory or relapsed chronic lymphocytic leukemia (CLL). Treatment with campath is associated with an increased incidence of infections and also fatal reactivation of viral infections. Reactivation of hepatitis B virus (HBV) in HBsAg‐positive patients is a well‐documented complication of cytotoxic or immunosuppressive therapy and has also been observed after treatment with rituximab. To date, there are no reports on campath treatment in HBsAg carriers. Here, we present the case of a patient with heavily pretreated CLL who was HBsAg‐positive with a high virus load (>2 billion copies/mL). He required treatment because of progressive CLL with massive bone marrow infiltration, severe anemia and thrombocytopenia. Campath was initiated and lamivudine, an inhibitor of reverse transcriptase, was simultaneously given to prevent HBV proliferation. During the treatment, no deterioration of liver parameters was observed, and the virus load decreased. After therapy with campath, hemoglobin and platelet counts increased markedly. This report shows that lamivudine is highly effective in inhibiting HBV proliferation and can be used to prevent HBV flare‐up during campath treatment in patients tested positive for HBs antigen.
Ultrasonic backscatter of the carotid wall in young and older athletes
Authors: Franzoni F. , Galetta F. , Cupisti A. , Femia F. R. , Pentimone F. , Santoro G.
Published: December 2003

Objectives.  The aim of this study was to evaluate the effects of habitual exercise on the age‐related changes of carotid wall composition defining its acoustic reflectivity by the quantitative approach of integrated backscatter (IBS) analysis.

Design.  Cross‐sectional study.

Setting.  University Hospital.

Subjects.  Fifty‐four competitive long‐distance runners (males, age range 22–72 years) and 50 healthy sedentary controls.

Main outcome measures.  All the subjects underwent both 2‐D conventional ultrasonography and IBS analysis. IBS values were sampled from a region of interest (ROI) placed within five consecutive regions of the common carotid intima–media, and then corrected (C‐IBS) for the IBS value of the adventitia.

Results.  Athletes showed a lower C‐IBS (−27.07 ± 2.9 dB vs. −24.57 ± 4 dB, P < 0.0001) and a smaller intima–media thickness (IMT: 0.64 ± 0.16 mm vs. 0.78 ± 0.21 mm, P < 0.001) respect to sedentary controls. By selecting the lowest (<30 years of age) and the highest (>60 years of age) tertile of age, we assess the influence of age on IMT and IBS. Sedentary older individuals exhibited an IMT higher respect to young controls and to the both trained subgroups (P < 0.0001). C‐IBS was lower in both subgroups of athletes, independently of age, and lower in sedentary young people respect to sedentary older subgroup (P < 0.0001). Endurance chronic exercise blunted the difference of C‐IBS observed between young and older sedentary individuals. Moreover, C‐IBS was positively related to age (r = 0.77, P < 0.0001) and IMT (r = 0.52, P < 0.0001).

Conclusions.  The age‐related changes of the arterial wall are attenuated by physical training. These modifications can be quantitatively discriminated by ultrasonic backscatter method.
Skeletal muscle and nutritional assessment in chronic renal failure patients on a protein‐restricted diet
Authors: Cupisti A. , Licitra R. , Chisari C. , Stampacchia G. , D'Alessandro C. , Galetta F. , Rossi B. , Barsotti G.
Published: December 2003

Background.  The close relationship between protein–energy malnutrition and quality of life, morbidity and mortality, makes mandatory a careful evaluation of the nutritional status and muscle mass in chronic renal failure (CRF) patients.

Methods.  Nutritional and skeletal muscle data were obtained from 28 nondiabetic patients with severe CRF (glomerular filtration rate, GFR < 15 mL min−1) on conservative treatment. Of them, 14 (8 males, 4 females) were on a conventional low‐protein (0.6 g kg−1 body weight) diet (LPD) and 14 (8 males, 4 females) were on a very low‐protein (0.3 g kg−1 body weight) diet supplemented with essential amino acids and ketoacids (Ketodiet); 28 healthy sex‐ and age‐matched subjects served as controls. We evaluated biochemistry, anthropometry, bioelectrical impedance vector analysis, and three noninvasive tests investigating some skeletal muscle features: (a) myoelectrical fatigue phenomenon was studied using a surface electromyography technique that provides data on conduction velocity (CV), median frequency of power spectrum (MDF) and average rectified value (ARV) of myofibre action potential, at 15 and 35 Hz stimulation frequency; (b) muscle oxidative metabolism was studied by serum lactate following aerobic exercise; and (c) muscle strength of the legs was studied using an isokinetic exercise test at two different angular velocities (60° and 180° s−1).

Results.  No difference between patients and controls was detected regarding CV, MDF and ARV, at 35 and 15 Hz testing. Serum lactate was higher in patients than in controls at 1, 5, 10 and 30 min recovery. A decreased knee extension and flexion strength was detected in CRF patients both at low (60° s−1) and at high (180° s−1) angular velocity; muscle strength deficit negatively correlated to serum albumin (r = −0.52, P < 0.01), but no relationship was found with protein intake or residual renal function. No difference was found between LPD and Ketodiet patients regarding the studied muscular tests as well as the anthropometry and bio‐impedance data.

Conclusions.  Implementation of a proper dietary regimen, including severe restriction of protein intake can preserve lean body mass and nutritional status of advanced CRF patients. Skeletal muscle shows unchanged sarcolemma excitability but abnormal oxidative metabolism and reduced segmental strength. Regular physical activity and a close clinical and dietary monitoring should be recommended for the predialysis patient care.
The value of malt distillers’ grains ensiled with molassed sugar beet pellets as a feed for dairy cows
Authors: McKendrick E. J. , Roberts D. J. , Offer N. W.
Published: December 2003

In one experiment twenty‐four Holstein Friesian cows, average 43 d post‐partum, were used in a changeover design experiment to evaluate the replacement of a cereal‐based concentrate supplement (C) by an ensiled mixture (MGBP) of malt distillers’ grains and molassed sugar beet pellets. The cows were offered grass silage ad libitum [dry matter (DM) content 170 g kg−1, crude protein (CP) concentration 160 g kg DM−1, metabolizable energy (ME) concentration 10·9 MJ kg DM−1] and either C or MGBP at one of three levels (3, 6, 9 kg DM d−1). The composition of C and MGBP were DM content: 853 and 296 g kg−1, CP concentration: 202 and 187 g kg DM−1, ME concentration: 12·6 and 10·8 MJ kg DM−1 respectively. The cows ate all the C supplement but the intakes of MGBP were 2·7, 4·9 and 6·4 kg DM d−1 for the 3, 6 and 9 kg DM d−1 levels of MGBP respectively. Total DM intakes (kg d−1) were 12·5, 15·6, 18·2 for treatments 3‐C, 6‐C and 9‐C and 13·1, 14·4 and 15·9 (s.e., 0·90) for treatments 3‐MGBP, 6‐MGBP and 9‐MGBP respectively. Milk yields (kg d−1) for treatments 3‐C, 6‐C and 9‐C were 19·9, 23·2 and 24·2, respectively, and for treatments 3‐MGBP, 6‐MGBP and 9‐MGBP were, 20·3, 21·3 and 23·0 respectively (s.e., 1·05). Milk fat contents (g kg−1) for treatments 3‐C, 6‐C and 9‐C were 42·8, 42·3, 43·5 respectively and for treatments 3‐MGBP, 6‐MGBP and 9‐MGBP were 39·5, 38·7 and 38·2 (s.e, 1·86), respectively, and milk protein contents (g kg−1) for treatments 3‐C, 6‐C and 9‐C were 30·5, 30·6, 31·8, respectively, and for 3‐MGBP, 6‐MGBP and 9‐MGBP were 30·0, 30·8 and 31·2 (s.e., 0·66) respectively. Milk yield and milk protein contents were significantly higher for the higher levels of supplementary feeding but there was no difference between the types of supplement. The milk fat contents were significantly lower on the MGBP than C supplements.

In a second experiment fifteen Holstein Friesian cows, average 126 d post‐partum, were used in a changeover experiment to evaluate the replacement of all (treatment M) or half (treatment MS) of the grass silage (S) in their diet by a mixture of MGBP and straw. All cows received 5·1 kg DM d−1 of concentrate feed. Forage DM intakes were 8·3, 11·2 and 14·2 kg DM d−1 for the S, MS and M treatments respectively. Milk yields (kg d−1) for S, MS and M treatments were 17·0, 19·4 and 20·0 (s.e., 0·56) respectively. Corresponding contents of milk fat and protein (g kg−1) were 42·0, 41·4, 38·6 (s.e., 0·37) and 33·8, 34·1, 34·2 (s.e., 0·42).

Ensiled mixtures of malt distillers’ grains and molassed sugar beet pellets can be used to replace some of the conventional concentrates or grass silage for dairy cows giving moderate yields without a loss of production.
Diabetes control in Swedish community dwelling elderly: more often tight than poor
Authors: Löfgren U.‐B. , Rosenqvist U. , Lindström T. , Hallert C. , Nystrom F. H.
Published: December 2003

Objective.  To determine glycaemic control in elderly patients with diabetes living in community dwelling.

Design.  Descriptive, cross‐sectional and open. Prospective with regard to blood glucose.

Setting.  Community‐dwelling in‐patients.

Subjects.  From a total number of 351 patients in seven Swedish centres of community dwelling we identified and recruited all 45 patients with diabetes receiving treatment with insulin, and/or oral medication.

Main outcome measures.  Blood glucose was measured fasting, 2 h after breakfast, in the evening and at night, for three consecutive days.

Results.  Mean HbA1c was 5.9 ± 1.1% (range 3.6–8.6%). The patients were split in three HbA1c‐groups for analysis: lower‐ (3.6–5.3%), middle‐ (5.4–6.3%) and higher‐tertile (6.4–8.6%). The groups where similar with regard to age, time in community dwelling, ability to eat and move around independently, but body mass index was lower in the lower tertile (P < 0.003 and P < 0.04, compared with middle‐ and higher‐tertiles). We recorded 14 episodes with blood glucose ≤4.0 mmol L−1 in eight patients. Blood glucose ≤4.0 mmol L−1 was mostly recorded during night (n = 8) or in the morning (n = 3).

Conclusions.  Swedish patients with diabetes in community dwelling are over‐ rather than under‐treated and have low HbA1c levels. Despite very regular eating habits and near total compliance with medication, hypoglycaemias are frequent and possibly linked to malnutrition.
Endemic goiter in pregnant women: utility of the simplified classification of thyroid size by palpation and urinary iodine as screening tests
Authors: Castañeda Rutila , Lechuga Diana , Ramos Rosa Isela , Magos Clementina , Orozco Maribel , Martıacute;nez Homero
Published: December 2003

Objective
To validate urinary iodine (I) excretion and the simplified classification of goiter by palpation, comparing them with ultrasound of the thyroid gland as the gold standard, to identify endemic goiter in pregnant women.

Population and setting
300 pregnant women identified in referral hospitals, in three geographic regions.

Methods
Two endocrinologists, previously trained, evaluated thyroid size by palpation and by ultrasound. Urinary iodine excretion in a sample of urine was determined. Thyroid size below the 90th centile by ultrasound was considered normal.

Results
Mean age of study women was 23 years old. The prevalence of low weight for gestational age was 39% and of anaemia 47%. Our sample distribution showed that 120 μg I/L was the best cut off for low urinary iodine excretion to identify endemic goiter in pregnant women (sensitivity 57% and specificity 70%, likelihood ratio of 1.4). The prevalence of goiter was 10% using ultrasound. Palpation had a sensitivity of identification goiter of 94% (95% CI 89–99%), a specificity of 80% (95% CI 75–85%), a likelihood ratio of 4.7, positive post‐test probability of 36.5% and negative post‐test probability of 99%.

Conclusions
Low urinary iodine excretion identified up to 46% of women with goiter. This test by itself is not useful as a screening tool to identify pregnant women at risk of goiter. Identification of thyroid size by palpation was a better screening test. However, when both tests were combined in parallel, up to 100% of women with goiter were correctly identified. Our results suggest that the commonly used cut off point of 100 μg I/L to identify low urinary iodine excretion may under‐estimate the prevalence of iodine deficiency disorders when used during pregnancy.
Analgesia in labour and fetal acid–base balance: a meta‐analysis comparing epidural with systemic opioid analgesia
Authors: Reynolds Felicity , Sharma Shiv K. , Seed Paul T.
Published: December 2003

Objective
To assess the effect of epidural versus systemic labour analgesia on funic acid–base status at birth.

Design
A systematic review of trials, both randomised and non‐randomised, comparing epidural with systemic opioid analgesia.

Population
Babies of 2102 mothers taking part in trials comparing epidural with systemic analgesia in five countries.

Methods
From the published and unpublished figures obtained from authors, fetal pH data from 12 studies (eight randomised) (1098 babies in the epidural group + 1004 controls) and base excess from 8 studies (four randomised) (856 epidural + 842 controls) were subjected to random effect meta‐analysis.

Main outcome measures
Umbilical artery pH and base excess values.

Results
Fetal pH was higher in the epidural than in the control group in the randomised trials (difference +0.009, 95% CI +0.002 to +0.015), but when all studies were included, the difference was not significant (+0.004, 95% CI −0.005 to +0.014). Fetal base excess was higher in the epidural group in the four randomised studies (difference +0.779 mEq/L, 95% CI +0.056 to +1.502) and in all eight studies (difference +0.837 mEq/L, 95% CI +0.330 to +1.343).

Conclusion
Umbilical artery pH is influenced by maternal hyperventilation. Base excess is therefore a better index of metabolic acidosis after labour. Epidural analgesia is associated with improved neonatal acid–base status, suggesting that placental exchange is well preserved in association with maternal sympathetic blockade and good analgesia. Although epidural analgesia may cause maternal hypotension and fever, longer second stage of labour and more instrumental vaginal deliveries, these potentially adverse factors appear to be outweighed by benefits to neonatal acid–base status.
The impact of multiple preterm births on the family
Authors: Bryan Elizabeth
Published: December 2003

Multiple births are important contributors to the preterm and low birthweight population and the numbers of twin births have been steadily rising since the early 1980s in all developed countries. This is largely due to the increased use of ovulation induction and multi‐embryo transfer in the treatment of subfertility. Parents of preterm twins have been shown to be less responsive to their infants than those with singletons. Parental stress with twins has also been demonstrated by the higher incidence of maternal depression and of child abuse in multiple birth families. Furthermore, siblings of twins are more likely to have behaviour problems. Mortality and long‐term morbidity rates are greatly increased amongst multiple birth children. The problems of the single surviving twin and the unaffected co‐twin of a disabled child are often underestimated as is the complexity of the bereavement of parents who still have surviving multiples. Addressing the cause of the epidemic of iatrogenic multiple births is likely to be the single most effective way to reduce the number of preterm infants and the long‐term problems to which they are prone.
Classification and heterogeneity of preterm birth
Authors: Moutquin Jean‐Marie
Published: December 2003

Three main conditions explain preterm birth: medically indicated (iatrogenic) preterm birth (25%; 18.7–35.2%), preterm premature rupture of membranes (PPROM) (25%; 7.1–51.2%) and spontaneous (idiopathic) preterm birth (50%; 23.2–64.1%). The majority of multiple pregnancies (10% of all preterm births) are delivered preterm (50% for medical reasons). Although medical indications relate more to feto‐maternal conditions, PPROM to infections and idiopathic preterm birth to lifestyle, these risk factors are identified in any category, emphasising that preterm birth has a multifactorial origin. Still, several incidences of preterm birth are not completely explained with a plausible cause for PPROM or spontaneous preterm labour suggesting that other causes have yet to be identified. In addition, preterm birth is associated with unrecognised severe congenital anomalies. Variability within the main categories may be explained by the studied population, ethnic group, social class and preventive interventions towards reducing spontaneous preterm birth where the proportion of medically‐indicated preterm birth is increased. Despite being retrospective a classification according to gestational age at birth is important for neonatal prognosis. Preterm birth is stratified into mild preterm (32–36 weeks), very preterm (28–31 weeks) and extremely preterm (<28 weeks) with increasing neonatal mortality and morbidity. Recent studies suggested that infection was mostly responsible for extreme preterm birth, while stress and lifestyle accounted for mild preterm birth, and a mixture of both conditions contributed to very preterm birth.
The case for tocolysis in threatened preterm labour
Authors: Fisk Nicholas M. , Chan Jerry
Published: December 2003

The failure of tocolytics to improve neonatal outcomes in placebo‐controlled trials has wrongly been interpreted as evidence that they do not work. While delivery is unequivocally prolonged by 24 hours, 48 hours and 7 days, the time gained was not exploited to optimise neonatal outcome. These trials typically studied women at relatively advanced gestational ages with predictably good outcomes, enrolled them in tertiary centres where they could not benefit from in‐utero transfer, and had low levels of corticosteroid administration. No study has been powered to detect clinically meaningful differences that might be expected to accrue from 1–7 days prolongation of gestation. Despite this, Bayesian interpretation suggests that tocolytics do improve neonatal outcome. The largest placebo‐controlled study showed clear trends towards better survival in fetuses <28 weeks, lower rates of cerebral palsy and higher Bayley mental scores. Meta‐analysis of neonatal morbidity in the beta‐agonist trials suggests a near‐significant reduction in respiratory distress syndrome (RDS), together with trends towards reduced intraventricular haemorrhage, necrotising enterocolitis, and patent ductus arteriosus. Finally, there is the Orwellian analogy that tocolytics don't work, but some work better than others. Although calcium antagonists have not been evaluated against placebo, meta‐analysis of comparative trials with beta‐agonists demonstrate a significantly lower incidence of RDS and neonatal jaundice, presumably mediated through the reduced chance of delivery within 48 hours and 7 days. Development of tocolytics that are safe for mother and baby should facilitate adequately‐powered placebo‐controlled studies, which both focus on women most likely to benefit and capitalise on the 1–7 days gained.
The development and introduction of anti‐oxytocic tocolytics
Authors: Lamont Ronald F.
Published: December 2003

The perfect tocolytic agent, which is completely safe for both the mother and fetus and, which will inhibit uterine contractions and stop preterm labour in every case does not exist and the search continues. Recently, research into a new group of tocolytic agents (the oxytocic antagonists) has led to the introduction of a new licensed drug, atosiban. Since the early 1950s, modifications of the oxytocin molecule have resulted in many analogues and antagonists, though initially none emerged as potentially useful drugs. Further modifications resulted in full uterotonic antagonism in animal models before an analogue was found that inhibited vasopressin‐stimulated uterine contractions in non‐pregnant healthy women. In vitro and animal models suggested the molecule was fully antagonistic, although it was found to be only partially agonistic in women. Further developments led to two modified oxytocin molecules with higher receptor affinity for human myometrium, both of which lacked agonism in humans. The analogue, atosiban, was found to be more potent and so was chosen for clinical evaluation in dysmenorrhoea and preterm labour. The first clinical reports were open label, observational pilot studies. Randomised, double‐blind, phase II placebo‐controlled studies followed showing that atosiban was significantly more effective than placebo with very few side effects. Dose‐response studies and phase III studies in which study or placebo groups could use alternative tocolytic agents also suggested that atosiban was an effective tocolytic agent with very few adverse events. The recent worldwide comparative study of atosiban versus different beta‐agonists represents the largest and most strictly controlled study of tocolytics ever published. Atosiban was found to be at least as effective as the beta‐agonists as a tocolytic agent, but significantly less likely to result in maternal cardiovascular side effects or the need to discontinue therapy as a result of unacceptable side effects.