bluuebunny/crossref_metadata_2025 huggingface dataset:
Recovery and life span of 111indium‐radiolabeled platelets treated with pathogen inactivation with amotosalen HCl (S‐59) and ultraviolet A light
Authors: Snyder Edward , Raife Thomas , Lin Lily , Cimino George , Metzel Peyton , Rheinschmidt Margaret , Baril Laurene , Davis Kathryn , Buchholz D.H. , Corash Laurence , Conlan Maureen G.
Published: December 2004

BACKGROUND:  A photochemical treatment (PCT) method to inactivate pathogens in platelet concentrates has been developed. The system uses a psoralen, amotosalen HCl, coupled with ultraviolet A (UVA) illumination.

STUDY DESIGN AND METHODS:  Three sequential clinical trials evaluated viability of PCT platelets prepared with a prototype device. Posttransfusion recovery and lifespan of 111Indium‐labeled autologous 5 day‐old platelets in healthy subjects was assessed. In the first study, 23 subjects received transfusions of autologous PCT and/or control platelets. In a second study, 16 of these subjects received PCT platelets processed with a Compound Adsorption Device (CAD) (PCT‐CAD) to reduce patient exposure to residual amotosalen. In the third study, the effect of gamma‐irradiation on PCT platelets was studied. Data from control transfusions from Study A were used for paired comparisons in the latter 2 studies.

RESULTS:  Mean PCT‐CAD platelet recovery for the 16 subjects with paired data was 42.5 ± 8.7% versus 50.3 ± 7.7% for control platelets, mean difference of 7.8% (p < 0.01). Mean lifespan for PCT‐CAD platelets was 4.8 days (±1.3) versus 6.0 days (±1.2) for control platelets, mean difference of 1.3 days (p < 0.01). Platelet recovery and lifespan were similar to PCT‐CAD for PCT without CAD treatment and PCT‐CAD with gamma‐irradiation.

CONCLUSION:  Viability of 5 day‐old PCT platelets was less than for control platelets. However, both were within ranges reported for 5 day‐old platelets.
Initiation of peripheral blood progenitor cell harvest based on peripheral blood hematopoietic progenitor cell counts enumerated by the Sysmex SE9000
Authors: Suh Cheolwon , Kim Shin , Kim Sang‐Hee , Kim Eun‐Kyung , Lee Jae‐Lyun , Park Keon‐Uk , Park Jung Sun , Lee Jungsin , Kim Michael W. , Chi Hyun‐Sook , Park Chan Jeong , Kim Sang We
Published: December 2004

BACKGROUND:  The most reliable index for timing peripheral blood progenitor cell (PBPC) collection following mobilization is still to be determined. The techniques to enumerate peripheral blood (PB) CD34+ cells are expensive and time‐consuming. The SE9000 (Sysmex) provides an estimate of immature cells, called hematopoietic progenitor cells (HPCs). The aim of this study was to prospectively evaluate the efficacy of PB HPC levels for timing PBPC harvest.

STUDY DESIGN AND METHODS:  Thirty‐five patients (15 non‐Hodgkin's lymphoma and 20 multiple myeloma) were enrolled. PB HPCs and harvested CD34+ cells were counted with the SE9000 and flow cytometry, respectively. Circulating HPCs were monitored daily. PBPC harvest was initiated when HPC levels reached at least 5 per mm3.

RESULTS:  HPC levels reached 5 per mm3 or more on Median Day 12 (range, days 9 to 16) of mobilizing chemotherapy. The median number of CD34+ cells collected per patient was 19.40 × 106 per kg (range, 1.94 × 106‐52.55 × 106 per kg). Both successful and optimal harvest was achieved in 97 percent of patients. PBPCs were successfully harvested in 25 patients (71%) in one session. An optimal harvest in a single session was attained in 16 patients (46%).

CONCLUSION:  This might be the first prospective study showing the PB HPC level for timing PBPC harvest.
Immediate Disclosure or Secrecy? The Release of Information in Experimental Asset Markets
Authors: Ackert Lucy F. , Church Bryan, K. , Gillette Ann B
Published: December 2004

This paper reports the results of experimental asset markets designed to investigate how the public disclosure of uncertain information affects market and individual outcomes. In some markets, no information is released as trading starts, and in others, an imperfect pre‐announcement is disclosed. The reliability of the pre‐announcement varies across markets. Our data indicate under‐reaction to a pre‐announcement that is highly reliable and over‐reaction to one with much lower reliability. Price volatility is higher and allocational efficiency is lower with a pre‐announcement that reflects substantial uncertainty. Furthermore, when the reliability of the pre‐announcement is low, traders extract a smaller proportion of the total attainable profit. Thus, in a highly uncertain environment better outcomes may result when information is withheld. These results have important policy implications regarding the disclosure of information by the Federal Reserve. In a highly uncertain environment, better outcomes may actually result with less information.
Possible Pathways for Iraq's Political Evolution
Authors: Katzman Kenneth
Published: December 2004

Dr. Katzman is senior Iraq analyst at the Congressional Research Service.
Radical Islam: The Death of an Ideology?
Authors: Takeyh Ray , Gvosdev Nikolas K.
Published: December 2004

Dr. Takeyh is a senior fellow at the Council on Foreign Relations. Dr. Gvosdev is a senior fellow at the Nixon Center. The following is adapted from the conclusion of their recent book, The Receding Shadow of the Prophet: The Rise and Fall of Radical Political Islam (Praeger, 2004), reproduced with permission of Greenwood Publishing Group, Inc., Westport, CT.
Sino‐Arab Relations: New Developments And Trends
Authors: Liangxiang Jin
Published: December 2004

Mr. Jin is a research fellow with the Shanghai Institute for International Studies (SIIS).
Subjective Measures of Employment Opportunities and Interregional Migration
Authors: Carlsen Fredrik , Johansen Kåre
Published: December 2004

Abstract.  Empirical studies of interregional mobility routinely use regional unemployment differentials to characterize economic incentives to move between regions. In this paper, we present a new regional labour market indicator computed from survey data in which respondents are asked to evaluate local employment opportunities in their resident municipality and surroundings. The subjective measures of satisfaction with local employment opportunities have positive and significant impact on interregional migration flows, also when controlling for traditional measures of regional labour market conditions, including the regional unemployment rate. Contrary to most European studies, we find that regional labour market conditions have a strong effect on interregional migration flows.
Childhood externalizing and internalizing psychopathology in the prediction of early substance use
Authors: King Serena M. , Iacono William G. , McGue Matt
Published: December 2004

Aims  To examine the prospective relationships between childhood externalizing and internalizing disorders and substance use in early adolescence.

Design  Longitudinal, community‐based study of twins (aged 11 at intake; aged 14 at follow‐up).

Setting and participants  The sample was composed of twins participating in the Minnesota Twin Family Study, an epidemiological sample of twins and their families representative of the state population of Minnesota. A total of 699 twin girls and 665 twin boys participated at both time‐points.

Measurements  Twins participated in in‐person, life‐time diagnostic assessments of the following childhood DSM III‐R externalizing and internalizing disorders at age 11: conduct disorder, oppositional defiant disorder, attention deficit hyperactivity disorder, major depressive disorder and in addition, for girls only, overanxious disorder and separation anxiety disorder. At ages 11 and 14, substance use and abuse were assessed.

Findings  Externalizing psychopathology predicted having tried alcohol, nicotine and cannabis by age 14 as well as regular and advanced experience with these substances. Internalizing disorders showed weak effects, with only major depression at age 11 showing a significant relationship with substance use at age 14.

Conclusion  The results suggest that externalizing psychopathology is a robust prospective predictor of a variety of early onset substance use behaviors and is systematically related to degree of substance use involvement. The results also suggest that depression may predict initiation of licit substance use in early adolescence.
Effects of nicotine dependence on diurnal variations of subjective activation and mood
Authors: Adan Ana , Prat Gemma , Sánchez‐Turet Miquel
Published: December 2004

Aim  To study the influence of nicotine dependence on diurnal variations of subjective activation and mood in smokers, without restrictions in their usual smoking habits, compared with non‐smokers. We analysed independently the impact of the postlunch phenomenon, a semicircadian rhythm overlapped with diurnal variations.

Design and measurements  Every hour, from 0800 to 2100 hours, 60 students, 40 smokers and 20 non‐smokers, responded to questions on eight unipolar visual analogue scales; four referred to subjective activation and four to mood. Based on Fagerström's Test for Nicotine Dependence and on carbon monoxide expired air pre‐ and postsmoking, 20 smokers were classified as high‐dependent and 20 as low‐dependent smokers. At 0800 hours, smokers were in a state of nicotine deprivation. Circadian typology, sleep habits and other psychoactive substances consumption were controlled.

Findings  Subjective activation and mood of smokers improved after they smoked their first morning cigarette, and this effect was greater for high‐dependent subjects. Mood scores were lower in high‐dependent smokers throughout the day, intermediate in low‐dependent smokers and greater in non‐smokers. Smokers showed a delay in the diurnal maximum of subjective activation of 2 hours for low‐dependent and 3 hours for high‐dependent smokers. Moreover, high‐dependent smokers showed a lower amplitude of diurnal function of subjective activation. We observed a greater postlunch interference in smokers, with a larger decrease of subjective feelings in low‐dependent smokers.

Conclusions  Our data confirm that differences exist in the circadian rhythmicity between non‐smokers and smokers, and that the level of nicotine dependence in smokers is a relevant factor for the interpretation of the diurnal variations. The profiles obtained in smokers are consistent with models of nicotine deprivation‐reversal and with the hedonic homeostatic dysregulation nicotine addiction hypothesis.
Esomeprazole 40 mg i.v. provides faster and more effective intragastric acid control than pantoprazole 40 mg i.v.: results of a randomized study
Authors: Wilder‐Smith C. H. , Röhss K. , Bondarov P. , Hallerbäck B. , Svedberg L.‐E. , Ahlbom H.
Published: December 2004

Background : Oral esomeprazole 40 mg provides greater acid control than oral pantoprazole 40 mg.

Aim : To compare the effects on intragastric acid control of esomeprazole 40 mg administered intravenously with pantoprazole 40 mg intravenously.

Methods : Healthy Helicobacter pylori‐negative male and female subjects were enrolled into this single‐centre, open, randomized, two‐way crossover study. Esomeprazole 40 mg intravenously and pantoprazole 40 mg intravenously were administered as 15‐min infusions once daily at 09:00 hours for 5 days. Continuous 24‐h intragastric pH monitoring was carried out at baseline and on days 1 and 5.

Results : pH‐data were available for all 25 subjects who completed the study. Esomeprazole 40 mg intravenously resulted in 8.3 and 13.9 h with an intragastric pH > 4 on days 1 and 5 compared with 5.3 and 9.0 h, respectively for pantoprazole 40 mg intravenously (day 1: P < 0.001, day 5: P < 0.0001). During the first 4 h of dosing on day 1 corresponding values were 1.7 and 0.6 h respectively (P < 0.0001). A mean median pH above 4 on day 5 was only attained with esomeprazole 40 mg intravenously.

Conclusions : Once‐daily dosing with esomeprazole 40 mg intravenously provides faster and more pronounced intragastric acid control than pantoprazole 40 mg intravenously.
Alteration of the food web along the Antarctic Peninsula in response to a regional warming trend
Authors: Moline Mark A. , Claustre Hervé , Frazer Thomas K. , Schofield Oscar , Vernet Maria
Published: December 2004

In the nearshore coastal waters along the Antarctic Peninsula, a recurrent shift in phytoplankton community structure, from diatoms to cryptophytes, has been documented. The shift was observed in consecutive years (1991–1996) during the austral summer and was correlated in time and space with glacial melt‐water runoff and reduced surface water salinities. Elevated temperatures along the Peninsula will increase the extent of coastal melt‐water zones and the seasonal prevalence of cryptophytes. This is significant because a change from diatoms to cryptophytes represents a marked shift in the size distribution of the phytoplankton community, which will, in turn, impact the zooplankton assemblage. Cryptophytes, because of their small size, are not grazed efficiently by Antarctic krill, a keystone species in the food web. An increase in the abundance and relative proportion of cryptophytes in coastal waters along the Peninsula will likely cause a shift in the spatial distribution of krill and may allow also for the rapid asexual proliferation of carbon poor gelatinous zooplankton, salps in particular. This scenario may account for the reported increase in the frequency of occurrence and abundance of large swarms of salps within the region. Salps are not a preferred food source for organisms that occupy higher trophic levels in the food web, specifically penguins and seals, and thus negative feedbacks to the ecology of these consumers can be anticipated as a consequence of shifts in phytoplankton community composition.
Patterns and uncertainties of species' range shifts under climate change
Authors: Thuiller Wilfried
Published: December 2004

Although bioclimatic modelling is often used to estimate potential impacts of likely climate changes, little has been done to assess the reliability and variability of projections. Here, using four niche‐based models, two methods to derive probability values from models into presence–absence data and five climate change scenarios, I project the future potential habitats of 1350 European plant species for 2050. All 40 different projections of species turnover across Europe suggested high potential species turnover (up to 70%) in response to climate change. However variability in the potential distributional changes of species across climate scenarios was obscured by a strong variability in projections arising from alternative, yet equally justifiable, niche‐based models. Therefore, projections of future species distributions and derived community descriptors cannot be reliably discussed unless model uncertainty is quantified explicitly. I propose and test an alternative way to account for modelling variability when deriving estimates of species turnover (with and without dispersal) according to a range of climate change scenarios representing various socio‐economic futures.
Forest and agricultural land‐use‐dependent CO2 exchange in Thuringia, Germany
Authors: Anthoni P. M. , Knohl A. , Rebmann C. , Freibauer A. , Mund M. , Ziegler W. , Kolle O. , Schulze E.‐D.
Published: December 2004

Eddy covariance was used to measure the net CO2 exchange (NEE) over ecosystems differing in land use (forest and agriculture) in Thuringia, Germany. Measurements were carried out at a managed, even‐aged European beech stand (Fagus sylvatica, 70–150 years old), an unmanaged, uneven‐aged mixed beech stand in a late stage of development (F. sylvatica, Fraxinus excelsior, Acer pseudoplantanus, and other hardwood trees, 0–250 years old), a managed young Norway spruce stand (Picea abies, 50 years old), and an agricultural field growing winter wheat in 2001, and potato in 2002. Large contrasts were found in NEE rates between the land uses of the ecosystems. The managed and unmanaged beech sites had very similar net CO2 uptake rates (∼−480 to −500 g C m−2 yr−1). Main differences in seasonal NEE patterns between the beech sites were because of a later leaf emergence and higher maximum leaf area index at the unmanaged beech site, probably as a result of the species mix at the site. In contrast, the spruce stand had a higher CO2 uptake in spring but substantially lower net CO2 uptake in summer than the beech stands. This resulted in a near neutral annual NEE (−4 g C m−2 yr−1), mainly attributable to an ecosystem respiration rate almost twice as high as that of the beech stands, despite slightly lower temperatures, because of the higher elevation. Crops in the agricultural field had high CO2 uptake rates, but growing season length was short compared with the forest ecosystems. Therefore, the agricultural land had low‐to‐moderate annual net CO2 uptake (−34 to −193 g C m−2), but with annual harvest taken into account it will be a source of CO2 (+97 to +386 g C m−2). The annually changing patchwork of crops will have strong consequences on the regions' seasonal and annual carbon exchange. Thus, not only land use, but also land‐use history and site‐specific management decisions affect the large‐scale carbon balance.
Carbon isotope discrimination indicates improving water‐use efficiency of trees in northern Eurasia over the last 100 years
Authors: Saurer Matthias , Siegwolf Rolf T. W. , Schweingruber Fritz H.
Published: December 2004

We investigated the response of conifer trees in northern Eurasia to climate change and increasing CO2 over the last century by measuring the carbon isotope ratio in tree rings. Samples from Larix, Pinus and Picea trees growing at 26 high‐latitude sites (59–71°N) from Norway to Eastern Siberia were analysed. When comparing the periods 1861–1890 and 1961–1990, the isotope discrimination and the ratio of the intercellular to ambient CO2 concentration (ci/ca) remained constant for trees growing in mild oceanic climate and under extremely cold and dry continental conditions. This shows a strong coordination of gas‐exchange processes, consisting in a biochemical acclimation and a reduction of the stomatal conductance. The correlation for ci/ca between the two investigated periods was particularly strong for Larix (r2=0.90) and Pinus (r2=0.94), but less pronounced for Picea (r2=0.47). Constant ci/ca under increasing CO2 in the atmosphere resulted in improved intrinsic water‐use efficiency (Wi), the amount of water loss at the leaf level per unit carbon gain. We found that 125 out of 126 trees showed increasing Wi from 1861 to 1890 to 1961 to 1990, with an average improvement of 19.2±0.9% (mean±SE). The adaptation in gas exchange and reduced transpiration of trees growing in this region must have had a strong impact on the water and energy budget, resulting in a drier and warmer surface air layer today than would exist without this vegetation–climate feedback.
UV effects that come and go: a global comparison of marine benthic community level impacts
Authors: Wahl Martin , Molis Markus , Davis Andrew , Dobretsov Sergey , Dürr Simone T. , Johansson Josefin , Kinley Jeff , Kirugara David , Langer Matthias , Lotze Heike K. , Thiel Martin , Thomason Jeremy C. , Worm Boris , Zeevi Ben‐Yosef Dafna
Published: December 2004

Ambient UV radiation has substantially increased during the last decades, but its impact on marine benthic communities is hardly known. The aim of this study was to globally compare and quantify how shallow hard‐bottom communities are affected by UV during early succession. Identical field experiments in 10 different coastal regions of both hemispheres produced a consistent but unexpected pattern: (i) UV radiation affected species diversity and community biomass in a very similar manner, (ii) diversity and biomass were reduced to a larger extent by UVA than UVB radiation, (iii) ambient UV levels did not affect the composition of the communities, and (iv) any UV effects disappeared during species succession after 2–3 months. Thus, current levels of UV radiation seem to have small, predictable, and transient effects on shallow marine hard‐bottom communities.
Influence of pH and added gums on the properties of konjac flour gels
Authors: Huang Hsien‐Yi , Lin Kuo‐Wei
Published: December 2004

The gel strength and texture of konjac gel and mixed gels of konjac and various gums were measured after gelation at various concentrations of alkali. A selection of different alkaline reagents was used. Regardless of alkali concentration, increasing konjac levels caused a decrease in pH but an increase in hardness and strength of konjac/gellan gum mixed gels. The highest gel strength and hardness were given by mixed konjac/gellan gum gels using sodium carbonate as the gelling medium. Under similar gelling conditions, the addition of gellan gum resulted in the greatest gel hardness. Of the gums examined, a possible synergistic effect on konjac/gellan gum mixed gel texture was observed.
Distribution of the residence time in a single‐screw extruder with differing numbers of mixing elements
Authors: Seker Mahmut
Published: December 2004

Starch was extruded with sodium trimetaphosphate and sodium hydroxide in a single‐screw extruder at 40% moisture content and screw speeds of 90 and 140 r.p.m. The effect of screw configurations, which included one and two mixing elements, on mean residence time, spread of residence time distribution (RTD), and flow pattern were determined. Increasing the screw speed and reducing the number of mixing elements reduced mean residence time. Higher RTD spread values were obtained at a screw speed of 90 r.p.m. when compared with 140 r.p.m. and increasing the number of mixing elements in the screw increased the RTD spread. The flow pattern was between plug and mixed flow, and increasing the number of a mixing element in the screw did not significantly affect the flow pattern in the single‐screw extruder.
SPME‐GC‐MS analysis of volatile organic compounds in honey from Basilicata. Evidence for the presence of pollutants from anthropogenic activities
Authors: Bentivenga Giovanni , D'Auria Maurizio , Fedeli Pietro , Mauriello Giacomo , Racioppi Rocco
Published: December 2004

Solid‐phase microextraction gas chromatography‐mass spectrometry analysis of nineteen samples of honey from Basilicata (southern Italy) showed the presence of some flavour components never described before in honey. Furthermore, some phenyl‐substituted hydrocarbons were detected. These compounds may be derived from the wastewater treatment plant in the area. Furthermore, in honey collected near an oil extraction plant, hydrocarbons were found; these may be derived from such plants present in the area.
Effect of processing and storage conditions on the microbiological quality of minimally processed vegetables
Authors: Legnani Pier P. , Leoni Erica
Published: December 2004

The microbiological contamination of minimally processed vegetables was measured before and after processing and at different times and storage temperatures (5 and 10 days at 4 and 20 °C). To evaluate the efficacy of the overall process the water used for washing and rinsing the vegetables during the various phases of the operation were also examined. Thanks to the high quality of the vegetables at origin, simple chlorine treatment was sufficient to achieve a satisfactory reduction in coliforms, Escherichia coli, coliphages and saprophytic flora, thus ensuring that all of the freshly packed samples conformed to reference standards and guidelines. This conformity was maintained when the storage instructions indicated on the package (4 °C for 5 days) were followed. However, the persistence of faecal indicators after treatment suggested a potential risk of infection that could increase if the original contamination was higher. Microbiological examination of the water used for preliminary washing and for rinsing was seen to be useful in the assessment of the safety of the vegetables, at origin and after processing. The advantage of choosing coliphages for such monitoring is that they are indicators of viral contamination that can be measured rapidly. Critical points to be checked during the process are the levels of residual chlorine remaining in the washing tanks and the storage temperatures.
A systemic iridoviral disease in mullet, Mugil cephalus L., and tiger grouper, Epinephelus fuscoguttatus Forsskal: a first report and study
Authors: Gibson‐Kueh S , Ngoh‐Lim G H , Netto P , Kurita J , Nakajima K , Ng M L
Published: December 2004

A systemic iridoviral disease associated with high mortality was initially recognized in cultured mullet, Mugil cephalus L., and tiger grouper, Epinephelus fuscoguttatus Forsskal, by histopathology and transmission electron microscopy. Polymerase chain reaction was performed on tissues and viral isolates, using four published primer sets developed for the Red Sea bream iridovirus (RSIV). An indirect fluorescent antibody test was also performed on virus‐infected ATCC gruntfin (GF) and seabass, Lates calcarifer Bloch, (SB) cells using a monoclonal antibody, RSIV M10. Our results suggested that the mullet and tiger grouper iridovirus bears genetic and antigenic similarities to RSIV.
Strong correlation between isoprene emission and gross photosynthetic capacity during leaf phenology of the tropical tree species Hymenaea courbaril with fundamental changes in volatile organic compounds emission composition during early leaf development
Authors: KUHN U. , ROTTENBERGER S. , BIESENTHAL T. , WOLF A. , SCHEBESKE G. , CICCIOLI P. , KESSELMEIER J.
Published: December 2004

Changes of the volatile organic compounds (VOC) emission capacity and composition of different developmental stages of the tropical tree species Hymenaea courbaril were investigated under field conditions at a remote Amazonian rainforest site. The basal emission capacity of isoprene changed considerably over the course of leaf development, from young to mature and to senescent leaves, ultimately spanning a wide range of observed isoprene basal emission capacities from 0.7 to 111.5 µg C g−1 h−1 during the course of the year. By adjusting the standard emission factors for individual days, the diel courses of instantaneous isoprene emission rates could nevertheless adequately be modelled by a current isoprene algorithm. The results demonstrate the inadequacy of using one single standard emission factor to represent the VOC emission capacity of tropical vegetation for an entire seasonal cycle. A strong linear correlation between the isoprene emission capacity and the gross photosynthetic capacity (GPmax) covering all developmental stages and seasons was observed. The present results provide evidence that leaf photosynthetic properties may confer a valuable basis to model the seasonal variation of isoprenoid emission capacity; especially in tropical regions where the environmental conditions vary less than in temperate regions. In addition to induction and variability of isoprene emission during early leaf development, considerable amounts of monoterpenes were emitted in a light‐dependent manner exclusively in the period between bud break and leaf maturity. The fundamental change in emission composition during this stage as a consequence of resource availability (supply side control) or as a plant's response to the higher defence demand of young emerging leaves (demand‐side control) is discussed. The finding of a temporary emergence of monoterpene emission may be of general interest in understanding both the ecological functions of isoprenoid production and the regulatory processes involved.
The relationship between CO2 assimilation, photosynthetic electron transport and water–water cycle in chill‐exposed cucumber leaves under low light and subsequent recovery
Authors: ZHOU Y. H. , YU J. Q. , HUANG L. F. , NOGUÉS S.
Published: December 2004

The effects of chilling under low light (9/7 °C, 100 µmol m−2 s−1) on the photosynthetic and antioxidant capacities and subsequent recovery were examined in two (one tolerant and one sensitive) cucumber genotypes. Chilling resulted in an irreversible inhibition of net CO2 assimilation and growth for the sensitive genotype, which was accompanied by decreases in the maximum velocity of RuBP carboxylation by Rubisco (Vcmax), the capacity for ribulose‐1,5‐bisphosphate regeneration (Jmax), Rubisco content and activity, and the quantum efficiency of photosystem II, in the absence of any stomatal limitation of CO2 supply or inorganic phosphate limitation. In contrast, CO2 assimilation for the tolerant genotype fully recovered after chill. The chill‐induced decrease in the proportion of electron flux for photosynthetic carbon reduction was mostly compensated by an O2‐dependent alternative electron flux driven by the water–water cycle, especially in the sensitive genotype. Compared with the tolerant genotype, the sensitive genotype after chill showed reduced capacity for scavenging reactive oxygen species and increased accumulation of reactive oxygen species. The balance between O2‐dependent alternative electron flux and the capacity for scavenging reactive oxygen species in response to chill plays a major role in determining the tolerance of cucumber leaves to this stress factor. It is concluded that the water–water cycle operates at high rates when CO2 assimilation is restricted in cucumber leaves subjected to chill and low light conditions.
Annual cyclicity in high‐resolution stable carbon and oxygen isotope ratios in the wood of the mangrove tree Rhizophora mucronata
Authors: VERHEYDEN A. , HELLE G. , SCHLESER G. H. , DEHAIRS F. , BEECKMAN H. , KOEDAM N.
Published: December 2004

In the present study, the high‐resolution stable carbon (13C/12C) and oxygen (18O/16O) isotope ratio profiles in the wood of the mangrove Rhizophora mucronata Lam., a tropical tree species lacking distinct growth rings, were investigated. Variations of both isotope ratios revealed a remarkable annual cyclicity with lowest values occurring at the latewood/earlywood boundary (April–May) and highest values during the transition from earlywood to latewood (October–November). Based on the current knowledge of the physiology of this mangrove species, as well as on the current literature available on high‐resolution profiles of stable isotope ratios in tree rings, possible driving forces responsible for this seasonal pattern are discussed. The annual cyclicity, together with a conspicuous isotope pattern appearing in the El‐Niño year 1997, promises great potential for tropical dendrochronology.
Storage of Fresh Bovine Semen in a Diluent Based on the Ionic Composition of Cauda Epididymal Plasma
Authors: Verberckmoes S , Van Soom A , Dewulf J , De Pauw I , De Kruif A
Published: December 2004

Contents

For artificial insemination (AI) in cattle, much lower insemination doses can be applied when fresh semen is used instead of frozen–thawed semen. However, a particular disadvantage of fresh semen is its limited shelf life. As bovine spermatozoa can be stored for several weeks in the cauda epididymis without negative effects on their fertilizing capacity, it is an interesting organ to serve as a model in order to prolong the shelf life of fresh semen. First, the storage capacity of a diluent [cauda epididymal plasma (CEP‐1)] with the same ionic composition, pH and osmolarity as the bovine CEP was compared with a Tris diluent for extended preservation of fresh ejaculated bovine semen. Secondly, the ionic composition of the CEP‐1 diluent was modified (CEP‐2) and its storage capacity was compared with this of the CEP‐1 and Tris diluent. Finally, the effect of addition of different polyols (sorbitol, glycerol, mannitol) and egg yolk concentrations (5, 10 and 20%) to the CEP‐2 diluent was assessed. Sperm quality decreased rapidly in the CEP‐1 diluent. The quality and especially progressive motility of spermatozoa stored in the CEP‐2 diluent were better those in the CEP‐1 and Tris diluent. No significant effects of different sugars or egg yolk concentrations on the quality of fresh bovine semen in the CEP‐2 diluent were observed. In conclusion, the CEP‐2 diluent with 10% egg yolk and 1 g/l sorbitol may be used for extended preservation of fresh bovine semen at 5°C up to 6 days.
A Comparative Expression Analysis of Gene Transcripts in Post‐fertilization Developmental Stages of Bovine Embryos Produced in Vitro or in Vivo
Authors: Tesfaye D , Ponsuksili S , Wimmers K , Gilles M , Schellander K
Published: December 2004

Contents

This study was carried out to examine the temporal variation in the relative abundance of transcripts during the post‐fertilization stages of bovine embryos derived from in vitro or in vivo culture. For this purpose, cumulus–oocyte complexes obtained from ovaries from slaughterhouses were matured, fertilized and cultured in vitro. The in vitro culture was carried out using CR1 medium. In vivo embryos were derived from superovulated and artificially inseminated Simmental heifers and cows. Embryos were recovered from both systems approximately at day 1 (two‐cell), day 2 (four‐cell), day 3 (eight‐cell), day 4 (16‐cell), day 5 (morula) and day 7 (blastocyst) after insemination. Relative abundance of target transcripts was performed using real‐time PCR. The transcripts studied were the nucleosome assembly protein, mRNA for alivin 1, Pleckstrin homology Sec7 coiled domain, polyadenylate binding protein, NADH dehydrogenase subunit 2, high‐mobility group transcription factor, cytokine‐like nuclear factor, NY‐REN‐58 antigen mRNA, mRNA for KIAA1764 and one novel transcript. These transcripts were derived from our previous study conducted using mRNA differential display reverse transcription‐polymerase chain reaction (DDRT‐PCR) between in vitro‐produced bovine eight‐, 16‐cell, morula and blastocyst‐stage embryos. The results of the present study have demonstrated the temporal variation in the relative abundance of these transcripts between in vitro and in vivo culture systems. Such variation in the relative abundance of transcripts during the post‐fertilization developmental stages of in vitro and in vivo embryos may reflect the effect of the in vitro culture condition on the transcriptional activity thereby on the developmental competence of the resulting embryos.
In Vitro Sperm Penetration Speed and its Relationship with In Vivo Bull Fertility
Authors: Puglisi R , Balduzzi D , Galli A
Published: December 2004

Contents

The in vitro tests utilized to evaluate sperm quality represent an interesting and important approach to evaluate ejaculated fecundant capacity. In the present work, the oocyte‐penetrating ability of sperm from two bulls with low and two with high in vivo fertility rate was investigated. Sperm‐quality parameters, such as sperm concentration, total and progressive motility, acrosome and total sperm anomalies, proximal cytoplasmic drops and live : dead sperm ratio were assessed and batches of sperm homologues in these parameters were selected. In expt 1, a sperm : oocyte ratio of 3000 was used and the oocytes were fixed 5, 10, 15 and 18 h post‐insemination (hpi). In expt 2, the sperm : oocyte ratio was reduced to 1000 and the eggs were fixed at 8 and 10 hpi. The results, analysed by chi‐square test, showed significant differences (p < 0.001) among bulls at 15 hpi in expt 1 and 8 hpi in expt 2; nevertheless, no accordance was found between sperm penetration rate and in vivo fertility. At 18 hpi, the low‐fertility bulls exceeded the two high‐fertility bulls, supporting previous reports that suggest an opposite correlation between in vivo and in vitro fertility rate at low doses of heparin. Furthermore, a more efficient zona binding ability of one high‐fertility bull was pointed out in expt 2 after the reduction of sperm : oocyte ratio, as it reached the highest percentage of penetration when compared with all the others.
Vaginal and Cervical Dilatation Intrapartum is Associated with Eosinophilic Infiltration in the Cow but not in the Sheep
Authors: Wehrend A , Gümbel B , Leiser R , Failing K , Bostedt H
Published: December 2004

Contents

During parturition maximal dilatation of the vagina and cervix is necessary for expulsion of the neonate. The aim of the present study was to characterize the cell infiltration of the vagina and cervix that is associated with this event in cows and sheep. For this purpose, vaginal and cervical tissue were removed from four pluriparous cows and four sheep immediately after delivery of the neonate by biopsy under visual control (group 1), and the eosinophilic granulocytes were stained selectively. Four cows that were in interoestrus were used for control (group 2). In a third group of cows (n = 10), blood samples were taken to determine the concentration of eosinophilic granulocytes from the fifth day antepartum up to the sixth day postpartum (group 3). A high degree of infiltration with eosinophilic granulocytes was detected in the bovine vagina and cervix intrapartum but not during interoestrus and in the ovine tissue intrapartum (p < 0.001). In the bovine tissue, the cell density was higher in the vagina than in the cervix (p < 0.05). The intrapartal tissue infiltration was associated with a short‐term blood eosinopenia. In conclusion, this investigation demonstrates eosinophilic infiltration in the bovine vagina and cervix intrapartum, which differs from the situation in sheep. We suggest that this difference can be explained by the fact that cows deliver at high oestrogen and low progesterone values, but sheep show relatively high intrapartal P4 levels, which might suppress tissue infiltration with eosinophilic granulocytes.
Motility Assessment of Porcine Spermatozoa: a Comparison of Methods
Authors: Vyt P , Maes D , Rijsselaere T , Dejonckheere E , Castryck F , Van Soom A
Published: December 2004

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Although widely used in practice, visual motility assessment of boar spermatozoa is a very subjective method. The aim of this study was to compare the visual motility assessment of boar spermatozoa with two objective, automated systems, namely the Sperm Quality Analyzer (SQA‐IIC) and the Hamilton–Thorne computer‐based semen analyzer (HTR). In addition, concentrations as determined by the Bürker counting chamber and HTR were compared. Motility of 30 semen samples from 30 different boars (22 Piétrain, seven Landrace boars and one Large White) was examined during three consecutive days, subjectively by two independent persons (visual motility assessment) and objectively with both automated systems. The use of the SQA‐IIC and HTR for assessing boar sperm motility was evaluated and the repeatability of the measurements was estimated. The Sperm Motility Index (SMI), determined by SQA‐IIC, and the percentage motile spermatozoa determined by the HTR showed a good correlation (r = 0.71; p < 0.05). The visual examination performed by Person 2 showed a good correlation with the SMI (r = 0.81) and with the percentage of motile spermatozoa measured by the HTR (r = 0.66) (p < 0.05). There was a very poor correlation and a limited agreement between the visual assessments of both persons emphasizing the subjectivity of visual motility assessment. Nevertheless, motility scores of each person during the three consecutive days were highly correlated (r = 0.67 and 0.72, p < 0.05). The limits of agreement plots showed poor agreement between both persons and the HTR. The repeatability of measurements for most parameters evaluated by the HTR and by the SQA‐IIC was good with coefficients of variation below 10%. In addition, for fertile Piétrain boars (n = 22), reference values for the different HTR‐parameters are presented showing a high curvilinear velocity (157.3 ± 19.5 μm/s) and a low straightness and linearity of the movement of the spermatozoa (62.7 ± 8.7 and 35.5 ± 7.6%, respectively).

Concentration as determined by the Bürker counting chamber (56.0 ± 16.8 × 106/ml) was significantly higher compared with HTR measurement (37.6 ± 7.7 × 106/ml). The high number of counted cells and the low variation render the HTR concentration measurement more reliable. It can be concluded that visual motility assessment is highly subjective and should therefore be replaced by automated systems that allow for a more objective and detailed motility assessment of boar spermatozoa. In addition, based on the present results, highly repeatable results were obtained by the SQA‐IIC and especially by the HTR.
Combination of α‐interferon with lamivudine reduces viral breakthrough during long‐term therapy
Authors: JANG MYOUNG KUK , CHUNG YOUNG‐HWA , CHOI MIN HEE , KIM JEONG A , RYU SOO HYUNG , SHIN JUNG WOO , KIM IN SOOK , PARK NEUNG HWA , LEE HAN CHU , LEE YUNG SANG , SUH DONG JIN
Published: December 2004

Background and Aim:  Viral breakthrough is frequently encountered during long‐term lamivudine therapy, mostly associated with YMDD mutants. In this study, we investigated the effects of α‐interferon (IFN‐α) combined with lamivudine on the occurrence of viral breakthrough during long‐term lamivudine therapy.

Methods:  Eighty‐three patients with biopsy‐proven chronic hepatitis B were randomly allocated to a combination of lamivudine and IFN‐α (LAM/IFN; n = 41) or lamivudine only (LAM; n = 42), and then followed up for >12 months. We calculated the cumulative rate of undetectable serum HBV‐DNA and hepatitis B e antigen (HBeAg) loss, as well as the cumulative occurrence rate of viral breakthrough. We also evaluated the relationship between YMDD mutants and the occurrence of viral breakthrough.

Results  There was no difference in cumulative rates of undetectable serum HBV‐DNA (100%vs 100% at 24 months, P = 0.13) and cumulative rates of serum HBeAg loss between the LAM/IFN group and the LAM group (49%, 61% and 67%vs 31%, 39% and 42%, respectively, at 12, 24 and 36 months; P = 0.07). The cumulative occurrence rate of viral breakthrough, however, was significantly lower in the LAM/IFN group compared with the LAM group (5%, 20% and 30%vs 10%, 55% and 58%, respectively, at 12, 24 and 36 months; P = 0.006). From the patients with viral breakthrough, YMDD mutants were detected in 82% (18 of 22) of the LAM group in contrast with 56% (five of nine) of the LAM/IFN group in their sera.

Conclusion  IFN‐α combined with lamivudine may reduce viral breakthrough during long‐term lamivudine therapy, probably by suppressing the appearance of YMDD mutants.
Which patients benefit from hemodialysis therapy in hepatorenal syndrome?
Authors: WITZKE OLIVER , BAUMANN MARKUS , PATSCHAN DANIEL , PATSCHAN SUSANN , MITCHELL ANNA , TREICHEL ULRICH , GERKEN GUIDO , PHILIPP THOMAS , KRIBBEN ANDREAS
Published: December 2004

Background and Aim:  Hepatorenal syndrome (HRS) occurs in patients with advanced liver cirrhosis and has a poor outcome. The aim of the present study was to investigate which patients with HRS are likely to benefit from hemodialysis.

Methods:  Data were collected prospectively from 30 patients with Child‐Pugh C liver cirrhosis and HRS. Patients were either treated with continuous veno‐venous hemodialysis (CVVHD) if they were mechanically ventilated, or with intermittent hemodialysis (HD) if they were not mechanically ventilated. Prognosis was assessed by the Child‐Pugh and by the Model for End‐Stage Liver Disease (MELD) score. The primary aim of the study was the analysis of overall and 30‐day patient survival during hemodialysis therapy. To identify predictive factors of survival, variables obtained before the initiation of dialysis therapy were evaluated.

Results:  Patients’ 30‐day survival was 8/30 (median survival time 21 days). Among patients treated with mechanical ventilation, 30‐day survival time was 0/15 while 8/15 patients without mechanical ventilation survived more than 30 days (P < 0.001). Using a multivariate model, the relative hazards for serum albumin, international normalized ratio (INR) and catecholamine therapy were not different from one another (P > 0.05), indicating that these parameters were not independent predictors of survival. Mechanical ventilation was an independent risk factor for 30‐day (relative hazard 6.6 [1.6–27.7], P < 0.001) and overall survival (relative hazard 6.3 [1.5–26.5], P = 0.01). Child‐Pugh (P < 0.01) and the MELD (P < 0.01) score were predictive for overall survival independent of mechanical ventilation.

Conclusions:  Patients with HRS without mechanical ventilation may benefit from hemodialysis, whereas hemodialysis seems to be futile in patients with mechanical ventilation.
Natural course of inoperable esophageal cancer treated with metallic expandable stents: Quality of life and cost‐effectiveness analysis
Authors: XINOPOULOS DIMITRIOS , DIMITROULOPOULOS DIMITRIOS , MOSCHANDREA IOANNA , SKORDILIS PANAGIOTIS , BAZINIS ATHANASSIOS , KONTIS MARIOS , PARASKEVAS IOANNIS , KOUROUMALIS ELIAS , PARASKEVAS EMMANUEL
Published: December 2004

Background and Aim:  The aim of this study was to evaluate the efficacy and safety of endoscopic therapy with self‐expanding metallic endoprostheses in the management of malignant esophageal obstruction or stenosis and the cost‐effectiveness of the method in patients suffering from primary esophageal carcinoma. All patients with inoperable esophageal cancers treated with either laser palliation or endoprosthesis insertion were studied retrospectively.

Method:  Between May 1997 and December 2002 obstruction of the esophagus was diagnosed in 78 patients (52 male, 26 female, age range 53–102 years, mean 72.3 years). The etiology of obstruction was squamous cell carcinoma (n = 42) and adenocarcinoma of the esophagus (n = 36). The site of obstruction was in the upper (n = 1), in the middle (n = 38) and in the lower esophagus (n = 39). In 16 cases the gastroesophageal junction was also involved. Four patients had broncho‐esophageal fistulas. In all cases the tumor was considered non‐resectable. A total of 89 Ultraflex metal stents were introduced endoscopically. In 46 patients dilation with Savary dilators prior to stent placement was required.

Results:  Stents were placed successfully in all patients. After 48 h, all patients were able to tolerate solid or semisolid food. During the follow‐up period eight patients developed dysphagia due to food impaction (treated successfully endoscopically). Eleven patients presented with recurrent dysphagia 4–16 weeks after stenting due to tumor overgrowth and were treated with placement of a second stent. The median survival time was 18 weeks. There was no survival difference between squamous cell and esophageal adenocarcinoma. A cost‐effective analysis was performed, comparing esophageal stenting with laser therapy. The mean survival and the cost were similar. A small difference of 2156 was noted (23.103 and 22.947 for each group of patients, respectively). A significant improvement in quality of life was noted in patients that underwent stenting (96% and 75%vs 71% and 57% for the first 2 months).

Conclusion:  Placement of self‐expanding metal stents is a safe and cost effective treatment modality that improve the quality of life, as compared with other palliative techniques, for patients with inoperable malignant esophageal obstructions. In cases of expansion of the mass a second stent can be used; however, the overall survival of these patients, is poor.