bluuebunny/crossref_metadata_2025_split huggingface dataset:
Purification and characterization of hepatocyte growth factor (HGF) from human seminal plasma
Authors: DEPUYDT C. E. , ZALATA A. , FALMAGNE J.‐B. , BOSMANS E. , COMHAIRE F. H. 
Published: November 2003

Naturally occurring forms of hepatocyte growth factor/scatter factor (HGF/SF) have been purified by heparin‐Sepharose chromatography, followed by cation exchange chromatography from a pool of human seminal plasma. Using an enzyme‐linked immunosorbant assay, MDCK scatter assay, and Western blot analysis, it was found that, after heparin‐Sepharose chromatography, human HGF/SF present in seminal plasma eluted in two different fractions, between 0.72 and 0.85 M NaCl (fraction I) and between 0.95 and 1.10 M NaCl (fraction II). Further purification of fraction I by cation exchange chromatography resulted again in two fractions which eluted at 0.2–0.4 and at 0.6–0.8 M NaCl. The fraction which eluted at 0.2–0.4 M NaCl consisted of two biologically less active heavy chains of the heterodimeric form of HGF/SF (107.1 U/ng immunoreactive HGF), with approximate molecular weights of 65 and 62 kDa under reducing conditions. The second fraction, which eluted at 0.6–0.8 M NaCl, revealed three bands with molecular weights of 87, 65 and 62 kDa, respectively. The 87 kDa form is thought to be a single chain precursor of HGF/SF devoid of biological activity.After subjecting fraction II to cation exchange chromatography, only one major peak eluted between 0.9 and 1.0 M NaCl, and consisted of two biologically active heavy chains of the heterodimeric form of HGF/SF (708.3 U/ng immunoreactive HGF), with approximate molecular weights of 65 and 62 kDa under reducing conditions. Non‐reducing conditions for both fraction I and fraction II revealed only one band with a molecular weight of 68 kDa. The ratio of pro‐HGF/SF and less biologically active HGF/SF (fraction I) over mature heterodimeric HGF/SF (fraction II) was ≈1:3, in seminal plasma from sperm donors.In seminal plasma, pro‐HGF/SF represents an 87 kDa glycoprotein which, apparently, is converted by limited proteolysis into several bands with molecular weights of 65 and 62 kDa. This is the first report showing the presence of pro‐HGF/SF and heterodimeric mature HGF/SF, as well as less biologically active forms of HGF/SF in human seminal plasma.
Effect of male occupational heat exposure on time to pregnancy
Authors: THONNEAU P. , DUCOT B. , BUJAN L. , MIEUSSET R. , SPIRA A. 
Published: November 2003

The relationship between male occupational heat exposure and the time required to achieve a pregnancy [ TTP] was studied in a retrospective survey of 402 fertile couples. The TTP for the subgroups `exposure to heat' (median = 4.0 months; mean = 11.8; SD = 13.3) and `professional driver >3 h/day' (median = 4.5; mean = 14.4; SD = 28.5) was significantly longer (both p < 0.05) than for the controls (median = 2.8; mean = 7.8; SD = 13.3).Bakers and welders showed comparable results: only 14% of the bakers' partners became pregnant within 3 months (cf. 55% of controls, p < 0.05) and only 29% became pregnant within 6 months (cf. 74% of controls, p < 0.02).This study suggests that occupational exposure to heat is a `weak' risk factor for male subfertility.
Rubidium transport in the cyanobacterium Synechococcus R‐2 (Anacystis nidulans, S. leopoliensis) PCC 7942
Authors: RITCHIE R. J. 
Published: November 2003

ABSTRACT Synechococcus R‐2 is a unicellular blue‐green alga. The cells will grow on Rb+ as a substitute for K+ but at a slower rate (t2∼ 15 h versus 12 h). Potassium is not, strictly speaking, an essential element for Synechococcus. Rubidium duxes (using 86Rb+) are much slower than those of potassium, about 1 nmol m−2 s−1 in the light (0.35 mol m−3 Rb+). 86Rb+ fluxes in the dark are about 0.1 nmol m−2 s−1. These fluxes are very slow compared to those of Na+ and other ions. Isotopic influx of Rb+ can supply sufficient Rb+ to keep up with the demands for growth, but the net dux needed to keep up with growth in the light is a large proportion of the total observed dux. Kinetic studies of Rb+ uptake versus [Rb+] show two uptake phases consistent with a high‐affinity and a low‐affinity system. Both systems appear to be light‐activated. Transport of Rb+ appears to be passive at pHo 10 in the light and dark. There is no case for active transport of Rb+ at pHo 7.5 in the light, but a marginal case for active uptake in the dark (about 3 kJ mol−1). There is only a small effect of Na+ upon Rb+ transport. 86Rb+ should not be used in place of 42K+ in K+ nutrition studies as the details of Rb+ transport are different to those of K+ transport.
Function of leaf hamamelitol as a compatible solute during water stress treatment of Hedera helix L.
Authors: MOORE B. d. , TALBOT J. N. , SEEMANN J. R. 
Published: November 2003

ABSTRACTHamamelitol is an unusual branched‐chain sugar alcohol previously suggested to function as a leaf compatible solute. In this study, we have examined the leaf metabolism and intracelluiar compartmentalization of hamamelitol and other soluble sugars during long‐term water stress treatment of Hedera helix (English ivy). Total leaf hamamelitol content was relatively low in greenhouse control plants, but increased 2‐fold during water stress treatment to levels approaching those observed in field‐grown plants (6–7 μmol g−1 fresh weight). Using density gradient fractionation with non‐aqueous solvents, we showed that hamamelitol occurs primarily in the cytoplasm and vacuoles of leaf mesophyll cells. During water stress treatment most of the increase in leaf hamamelitol occurred in the mesophyll cytoplasm, compensating osmotically for a decrease in cytoplasmic sucrose concentration. The maximum concentration of cytoplasmic hamamelitol was 155 mol m−3 and occurred in field‐grown plants. Labelling experiments showed that hamamelitol is slowly synthesized from 14CO2 in leaves of H. helix, but is very long‐lived (estimated t1/2 of 4 years). Together, these data indicate that hamamelitol probably functions during long‐term stress conditions as an osmotically active, compatible solute in plant leaves. We suggest that the signal for enhanced accumulation of hamamelitol during the water stress treatment was initiated by decreased plant growth and increased leaf sucrose hydrolysis.
Element localization in ultrathin cryosections of high‐pressure frozen ectomycorrhizal spruce roots
Authors: FREY B. , BRUNNER I. , WALTHER P. , SCHEIDEGGER C. , ZIEROLD K. 
Published: November 2003

ABSTRACTWe present, for the first time, elemental mapping of ultra‐thin cryosections from high‐pressure frozen ectomycorrhizal roots of Picea abies–Hebeloma crustuliniforme. The maps provide interpretable information on the relationship between elements and the structure of inhomogeneous objects. Cryoultramicrotomy together with energy dispersive X‐ray microanalysis (EDX) offers the potential to study the subcellular localization of specific ions and ecologically important tracers (Cs and Sr) in ectomycorrhizal roots under conditions resembling the natural slate as closely as possible. Structural changes of the ectomycorrhizal roots, in particular the absence of a Hartig net at high NH4+ levels in the nutrient solution, were accompanied by elemental modification of Ca in cortical cell walls, where markedly higher concentrations of Ca were found. Cs and Sr applied to the nutrient solution were localized in root and fungal cells of the Hartig net. Cs accumulated mainly in the vacuoles of the Hartig net hyphae and its distribution was very similar to the distribution of K. In contrast to Cs, Sr was found to occur mainly in electron‐opaque and P‐rich granules. From this study, (here is no indication that Ca is the only ion accompanying P in the P‐rich granules. Several elements including Ca, K, Cl, S, Cs and Sr, with highest concentrations for S, can occur together with P in these granules. The occurrence of the P‐rich electron‐opaque deposits in fungal cells might be the first evidence of polyphosphate granules in the native state, since our specimen preparation technique did not include chemical fixation.
Uptake and transport of zinc in the hyperaccumulator Thlaspi caerulescens and the non‐hyperaccumulator Thlaspi ochroleucum
Authors: SHEN Z. G. , ZHAO F. J. , McGRATH S. P. 
Published: November 2003

ABSTRACTGrowth and zinc uptake of the hyperaccumulator species Thlaspi caerulescens J. & C. Presl and the non‐hyperaccumulator species Thlaspi ochroleucum Boiss. & Heldr. were compared in solution culture experiments. T. caerulescens was able to tolerate 500 mmol m−3 (32.5 g m−3) Zn in solution without growth reduction, and up to 1000 mmol m−3 (65 g m−3) Zn without showing visible toxic symptoms but with a 25% decrease in dry matter (DM) yield. Up to 28 g kg−1 of Zn in shoot DM was obtained in healthy plants of T. caerulescens. In contrast, T. ochroleucum suffered severe phytotoxicity at 500 mmol m−3 Zn. Marked differences were shown in Zn uptake, distribution and redistribution between the two species. T. caerulescens had much higher concentrations of Zn in the shoots, whereas T. ochroleucum accumulated higher concentrations of Zn in the roots. When an external supply of 500 mmol m−3 Zn was withheld, 89% of the Zn accumulated previously in the roots of T. caerulescens was transported to the shoots over a 33 d period, whereas in T. ochroleucum only 32% was transported. T. caerulescens was shown to have a greater internal requirement for Zn than other plants. Increasing the supply of Zn from 1 to 10 mmol m−3 gave a 19% increase in the total DM of this species. liven the shoots from the 1 mmol m−3 Zn treatment which showed Zn deficiency contained 10 times greater Zn concentrations than the widely reported critical value for Zn deficiency to occur in many other plant species. The results obtained suggest that strongly expressed constitutive sequestration mechanisms exist in the hyperaccumulator T. caerulescens, which detoxify the large amount of Zn present in shoot tissues and decrease its physiological availability in the cytosol. Both T. caerulescens and T. ochroleucum had constitutively high concentrations of malate in shoots, which were little affected by different Zn treatments. Although malate may play a role in Zn chelation because of the high concentrations present, it cannot explain the species specificity of Zn tolerance and hyperaccumulation.
Effects of nitrogen supply on the anatomy and chemical composition of leaves of four grass species belonging to the genus Poa, as determined by image‐processing analysis and pyrolysis–mass spectrometry
Authors: VAN ARENDONK J. J. C. M. , NIEMANN G. J. , BOON J. J. , LAMBERS H. 
Published: November 2003

ABSTRACTPrevious experiments have shown that the anatomy and chemical composition of leaves of inherently fast‐ and slow‐growing grass species, grown at non‐limiting nitrogen supply, differ systematically. The present experiment was carried out to investigate whether these differences persist when the plants are grown at an intermediate or a very low nitrogen supply. To this end, the inherently fast‐growing Poa annua L. and Poa trivialis L., and the inherently slow‐growing Poa compressa L. and Poa pratensis (L.) Schreb. were grown hydroponically at three levels of nitrate supply: at optimum (RGRmax) and at relative addition rates of 100 and 50 mmol N (mol N)−1 d−1 (RAR100 and RAR50), respectively.As expected, at the lowest N supply, the potentially fast‐growing species grew at the same rate as the inherently slow‐growing ones. Similarly, the differences in leaf area ratio (LAR, leaf area:total dry mass), specific leaf area (SLA, leaf arear:leaf dry mass) and leaf mass ratio (LMR, leaf dry mass:total dry mass) disappeared. Under optimal conditions, the fast‐growing species differed from the slow‐growing ones in that they had a higher N concentration. There were no significant differences in C concentration. With decreasing N supply, the total N concentration decreased and the differences between the species disappeared. The total C concentration increased for the fast‐growing species and decreased for the slow‐growing ones, i.e. the small, but insignificant, difference in C concentration between the species at RGRmax increased with decreasing N supply.The chemical composition of the leaves at low N supply, analysed in more detail by pyrolysis–mass spectrometry, showed an increase in the relative amounts of guaiacyl lignin, cellulose and hemicellulose, whereas those of syringyl lignin and protein decreased.The anatomy and morphology of the leaves of the four grass species differing in RGRmax were analysed by image‐processing analysis. The proportion of the total volume occupied by mesophyll plus intercellular spaces and epidermis did not correlate with the amount of leaf mass per unit leaf area (specific leaf mass, SLM) at different N supply. The higher SLM at low N supply was caused partly by a high proportion of non‐veinal sclerenchymatic cells per cross‐section and partly by the smaller volume of epidermal cells.We conclude that the decrease in relative growth rate (and increase in SLM) at decreasing N supply is partly due to chemical and anatomical changes. The differences between the fast‐ and slow‐growing grass species at an optimum nutrient supply diminished when plants were growing at a limiting nitrogen supply.
The gradient between pre‐dawn rhizoplane and bulk soil matric potentials, and its relation to the pre‐dawn root and leaf water potentials of four species
Authors: SCHMIDHALTER U. 
Published: November 2003

ABSTRACTUptake of soil water by plants may result in significant gradients between bulk soil and soil in the vicinity of roots. Few experimental studies of water potential gradients in close proximity to roots, and no studies on the relationship of water potential gradients to the root and leaf water potentials, have been conducted. The occurrence and importance of pre‐dawn gradients in the soil and their relation to the pre‐dawn root and leaf water potentials were investigated with seedlings of four species. Pre‐germinated seeds were grown without watering for 7 and lid in a silt loam soil with initial soil matric potentials of ‐0.02, ‐0.1 and ‐0.22 MPa. Significant gradients, independent of the species, were observed only at pre‐dawn soil matric potentials lower than ‐0.25 MPa; the initial soil matric potentials were ‐0.1 MPa. At an initial bulk soil matric potential of ‐0.22 MPa, a steep gradient between bulk and rhizoplane soil was observed after 7 d for maize (Zea mays L. cv. Issa) and sunflower (Helianthus annuus L. cv. Nanus), in contrast to barley (Hordeum vulgare L. cv. Athos) and wheat (Triticum aestivum L. cv. Kolibri). Pre‐dawn root water potentials were usually about the same as the bulk soil matric potential and were higher than the rhizoplane soil matric potential. Pre‐dawn root and leaf water potentials tended to be much higher than rhizoplane soil matric potentials when the latter were lower than ‐0.5 MPa. It is concluded that plants tend to become equilibrated overnight with the wetter bulk soil or with wetter zones in the bulk soil. Plants can thus circumvent negative effects of localized steep pre‐dawn soil matric potential gradients. This may be of considerable importance for water uptake and growth in drying soil.
Mood‐stabilizers: the archeology of the concept
Authors: Harris Margaret , Chandran Summit , Chakraborty Nabonita , Healy David 
Published: November 2003

Objective:  To review the history of ‘mood‐stabilizing’ treatments.Method:  We have reviewed primary source data on the origin of the use of current mood‐stabilizers.Results:  This historical record on the origins of the mood‐stabilizers points to a more ambiguous picture as regards pharmacotherapeutic specificity to bipolar disorders than is commonly conceded.Conclusions:  This review suggests a need for alternative formulations of the concept of a mood‐stabilizer. An alternative to the currently dominant paradigm is that these agents have treatment effects, which need to be matched more precisely with patients’ constitutional types in order to optimize outcomes.
Polymorphism of the brain‐derived neurotrophic factor gene and performance on a cognitive prefrontal test in bipolar patients
Authors: Rybakowski Janusz K , Borkowska Alina , Czerski Piotr M , Skibińska Maria , Hauser Joanna 
Published: November 2003

Objectives:  The aim of the study was to test a possible association between the Val66Met polymorphism of the brain‐derived neurotrophic factor (BDNF) gene and performance on a neurocognitive test, the Wisconsin Card Sorting Test (WCST), in bipolar patients.Methods:  Fifty‐four bipolar patients were studied, 18 male and 36 female, aged 18–72 (mean 46 years). The number of perseverative errors (WCST‐P), non‐perseverative errors (WCST‐NP), completed corrected categories (WCST‐CC), conceptual level responses (WCST‐%CONC) and set to the first category (WCST‐1st CAT) were measured in relation to the Val66Met genotypes of BDNF.Results:  The percentages of subjects with Val/Val, Val/Met and Met/Met genotypes were respectively 81.5, 16.7 and 1.8%. Subjects with Val/Val and Val/Met genotypes did not differ on clinical factors except for the age of onset of the illness, which was earlier in Val/Val than Val/Met genotype (27 years versus 38 years). The performance in all domains of WCST was significantly better in subjects with Val/Val BDNF genotype compared with Val/Met genotype.Conclusions:  The results suggest a role of BDNF in prefrontal cognitive function in bipolar illness. The tests of prefrontal cognition may be considered as endophenotypic markers in bipolar illness.
Recombinant human interferon beta in relapsing–remitting multiple sclerosis: a review of the major clinical trials
Authors: Chofflon M. 
Published: November 2003

In this article the percentage increase in relapse‐free patients at 1 year as shown in Table 3 was presented incorrectly. The correct information is that the results reported for IFN‐β‐1a 66 mcg (59%) and 132 mcg (87%) are both statistically significant (P < 0.05) versus placebo, and should therefore have been marked with an asterisk (*), as this is the case for all other statistically significant results displayed in the table. The author apologizes for this error. The corrected version of the table appears below.
Body packer: cocaine intoxication, causing death, masked by concomitant administration of major tranquilizers
Authors: Klein C. , Balash Y. , Pollak L. , Hiss J. , Rabey M. J. 
Published: November 2003

Cocaine, derived from the leaves of the shrubErythroxylon coca, which grows on the slopes of the Andes, remains one of the most widely abused illicit drugs (Johnsonet al., 1993). Its abuse appears to be increasing and as a result, so is its trafficking across borders, with ever‐increasing sophistication of concealment (Rouse, 1992).Over the past few years, cases of cocaine intoxication have been reported, resulting from ruptured packets of cocaine that have been swallowed, or inserted into the vagina or rectum by couriers (drug smugglers), so called ‘body packers’ or ‘mules’ (Westli and Mittleman, 1981;Ricaurte and Langston, 1995).Cocaine is a powerful sympathomimetic and central nervous system stimulant, an overdose of which causes primarily cardiac, neurological and psychiatric effects (Ricaurte and Langston, 1995). Acute toxicity is dose‐related and is characterized in the first place by its sympathomimetic effects, which include tachycardia, hypertension and hyperthermia arrythmias, followed by seizures. Brainstem depression and cardio‐respiratory collapse, stroke, coma, intracranial vasculitis, myocardial infarction and sudden death have all been reported in cocaine abuse (Ricaurte and Langston, 1995).We present a fatal case with neurological and psychiatric symptoms, but without the usual cardiac and systemic signs.
Identification of Native American Founder mtDNAs Through the Analysis of Complete mtDNA Sequences: Some Caveats
Authors: Bandelt H.‐J. , Herrnstadt C. , Yao Y.‐G. , Kong Q.‐P. , Kivisild T. , Rengo C. , Scozzari R. , Richards M. , Villems R. , Macaulay V. , Howell N. , Torroni A. , Zhang Y.‐P. 
Published: November 2003

SummaryIn this study, a detailed analysis of both previously published and new data was performed to determine whether complete, or almost complete, mtDNA sequences can resolve the long‐debated issue of which Asian mtDNAs were founder sequences for the Native American mtDNA pool. Unfortunately, we now know that coding region data and their analysis are not without problems. To obtain and report reasonably correct sequences does not seem to be a trivial task, and to discriminate between Asian and Native American mtDNA ancestries may be more complex than previously believed. It is essential to take into account the effects of mutational hot spots in both the control and coding regions, so that the number of apparent Native American mtDNA founder sequences is not erroneously inflated. As we report here, a careful analysis of all available data indicates that there is very little evidence that more than five founder mtDNA sequences entered Beringia before the Last Glacial Maximum and left their traces in the current Native American mtDNA pool.
A Metric Linkage Disequilibrium Map of a Human Chromosome
Authors: Tapper W. J. , Maniatis N. , Morton N. E. , Collins A. 
Published: November 2003

SummaryWe used LDMAP (Maniatis et al. 2002) to analyse SNP data spanning chromosome 22 (Dawson et al. 2002), to obtain a whole‐chromosome metric LD map. The LD map, with map distances analogous to the centiMorgan scale of linkage maps, identifies regions of high LD as plateaus (‘blocks’) and characterises steps which define the relationship between these regions. From this map we estimate that block regions comprise between 32% and 55% of the euchromatic portion of chromosome 22 and that increasing marker density within steps may increase block coverage. Steps are regions of low LD which correspond to areas of variable recombination intensity. The intensity of recombination is related to the height of the step and thus intense recombination hot‐spots can be distinguished from more randomly distributed historical events. The LD maps are more closely related to the high‐resolution linkage map (Kong et al. 2002) than average measures of ρ with recombination accounting for between 34% and 52% of the variance in patterns of LD (r = 0.58 – 0.71, p = 0.0001). Step regions are closely correlated with a range of sequence motifs including GT/CA repeats. The LD map identifies holes in which greater marker density is required and defines the optimal SNP spacing for positional cloning, which suggests that some multiple of around 50,000 SNPs will be required to efficiently screen Caucasian genomes. Further analyses which investigate selection of informative SNPs and the effect of SNP allele frequency and marker density will refine this estimate.
Logistic Regression Models for Polymorphic and Antagonistic Pleiotropic Gene Action on Human Aging and Longevity
Authors: Tan Qihua , Bathum L. , Christiansen L. , Benedictis G. De , Dahlgaard J. , Frizner N. , Vach W. , Vaupel J. W. , Yashin A. I. , Christensen K. , Kruse T. A. 
Published: November 2003

SummaryIn this paper, we apply logistic regression models to measure genetic association with human survival for highly polymorphic and pleiotropic genes. By modelling genotype frequency as a function of age, we introduce a logistic regression model with polytomous responses to handle the polymorphic situation. Genotype and allele‐based parameterization can be used to investigate the modes of gene action and to reduce the number of parameters, so that the power is increased while the amount of multiple testing minimized. A binomial logistic regression model with fractional polynomials is used to capture the age‐dependent or antagonistic pleiotropic effects. The models are applied to HFE genotype data to assess the effects on human longevity by different alleles and to detect if an age‐dependent effect exists. Application has shown that these methods can serve as useful tools in searching for important gene variations that contribute to human aging and longevity.