bluuebunny/crossref_metadata_2025_split huggingface dataset:
PHOTOINHIBITION OF PSII IN EMILIANIA HUXLEYI (HAPTOPHYTA) UNDER HIGH LIGHT STRESS: THE ROLES OF PHOTOACCLIMATION, PHOTOPROTECTION, AND PHOTOREPAIR1
Authors: Ragni Maria , Airs Ruth L. , Leonardos Nikos , Geider Richard J. 
Published: May 2008

The response of the coccolithophorid Emiliania huxleyi (Lohmann) W. H. Hay et H. Mohler to acute exposure to high photon flux densities (PFD) was examined in terms of PSII photoinhibition, photoprotection, and photorepair. The time and light dependencies of these processes were characterized as a function of the photoacclimation state of the alga. Low‐light (LL) acclimated cells displayed a higher degree of photoinhibition, measured as decline in Fv/Fm, than high‐light (HL) acclimated cells. However, HL cultures were more susceptible to photodamage but also more capable of compensating for it by performing a faster repair cycle. The relation between gross photoinhibition (observed in the presence of an inhibitor of repair) and PFD to which the algae were exposed deviated from linearity at high PFD, which calls into question the universality of current concepts of photoinhibition in mechanistic models. The light dependence of the de‐epoxidation state (DPS) of the xanthophyll cycle (XC) pigments on the timescale of hours was the same in cells acclimated to LL and HL. However, HL cells were more efficient in realizing nonphotochemical quenching (NPQ) on short timescales, most likely due to a larger XC pool. LL cells displayed an increase in the PSII effective cross‐section (σPSII) as a result of photoinhibition, which was observed also in HL cells when net photoinhibition was induced by blocking the D1 repair cycle. The link between σPSII and photoinhibition suggests that the population of PSII reaction centers (RCIIs) of E. huxleyi shares a common antenna, according to a “lake” organization of the light‐harvesting complex.
Effect of Transgenic Extrahepatic Expression of Betaine‐Homocysteine Methyltransferase on Alcohol or Homocysteine‐Induced Fatty Liver
Authors: Ji Cheng , Shinohara Masao , Vance Dennis , Than Tin Aung , Ookhtens Murad , Chan Christine , Kaplowitz Neil 
Published: May 2008

Background:  Chronic alcohol feeding induces hyperhomocysteinemia (HHcy). Previously, we reported a protective role of betaine‐homocysteine methyltransferase (BHMT) in homocysteine‐induced injury in cultured hepatocytes. In this study, we investigated the direct role of BHMT in alcohol or homocysteine‐induced liver injury.Methods:  Betaine‐homocysteine methyltransferase transgenic (Tg) mice were generated. Comparisons were made between the Tg and wild type (WT) mice in their response to intragastric alcohol infusion or to oral feeding of a high methionine low folate diet (HMLF).Results:  Expression of the Tg BHMT was increased in organs peripheral to the liver. The alcohol infusion for 4 weeks increased: plasma ALT by 5‐fold in WT mice and 2.7‐fold in Tg mice; plasma homocysteine by 7‐fold in WT mice and 2‐fold in Tg mice; liver triglycerides by 4‐fold in WT mice and 2.5‐fold in Tg mice. The alcohol‐induced fatty liver was more severe in WT than in Tg mice based on H&E staining. The HMLF feeding for 4 weeks increased plasma ALT by 2‐fold in WT mice and 1‐fold in Tg mice; plasma homocysteine by 21‐fold in WT mice and 3.3‐fold in Tg mice; liver triglycerides by 2.5‐fold in WT mice and 1.5‐fold in Tg mice. HMLF induced accumulation of macro fat droplets in WT but not Tg mice. Betaine supplementation decreased partially the alcohol or HMLF‐induced increase of ALT, homocysteine and liver lipids in WT mice. However, Tg mice were normal when fed both HMLF and betaine. In WT mice, both alcohol and HMLF induced moderate increase of sterol regulatory element binding protein 1 (SREBP1) protein which was partially reduced by betaine supplementation. In Tg mice, alcohol but not HMLF increased SREBP1. Carbohydrate responsive element‐binding protein was increased by alcohol in either WT or Tg mice which was not affected by betaine supplementation. Ratio of S‐adenosylmethionine (SAM) to S‐adenosylhomocysteine (SAH) was reduced by 50% in WT and by 20% in Tg mice fed alcohol. Ratio of phosphatidylcholine (PC) to phosphatidylethanolamine (PE) was reduced in WT but not Tg mice fed alcohol. Changes in PE methyltransferase activities were not detected in response to alcohol or HMLF feeding but were increased by betaine.Conclusions:  The BHMT Tg mice are resistant to alcohol or HMLF‐induced HHcy and liver steatosis indicating that peripheral metabolism of homocysteine protected the liver without a direct effect of BHMT in the liver. Multiple mechanisms are involved in protection by betaine including increased SAM/SAH and PC/PE ratios.
α‐Hemoglobin stabilizing protein is not a suitable marker for a screening test for variant Creutzfeldt‐Jakob disease
Authors: Appleford Nigel E.J. , Wilson Kim , Houston Fiona , Bruce Lesley J. , Morrison Alex , Bishop Matthew , Chalmers Kevin , Miele Gino , Massey Edwin , Prowse Chris , Manson Jean , Will Robert G. , Clinton Michael , MacGregor Ian , Anstee David J. 
Published: May 2008

BACKGROUND: A test is needed to identify blood donors who are in the preclinical phase of variant Creutzfeldt‐Jakob disease (CJD). α‐Hemoglobin stabilizing protein (AHSP; syn. ERAF, EDRF) transcript levels are reduced in the blood of mice incubating transmissible spongiform encephalopathy.STUDY DESIGN AND METHODS: Quantitative real‐time polymerase chain reaction and enzyme‐linked immunosorbent assay were used to measure AHSP transcript and protein levels in normal blood donors, patients with CJD, and patients with other neuronal and hematologic diseases. Temporal AHSP expression was measured in sheep incubating bovine spongiform encephalopathy (BSE).RESULTS: Quantitation of AHSP in peripheral blood from normal blood donors revealed that protein levels, but not transcript levels, are influenced by sex with higher levels found in males, suggesting posttranslational regulation involving the product of an X‐linked gene. When AHSP mRNA and protein levels were quantitated in peripheral blood from patients with variant and sporadic CJD, no consistent differences from normal were found. Serial quantitation of AHSP in individual BSE‐infected sheep did not reveal any disease‐related changes.CONCLUSION: We conclude that quantitation of AHSP is not likely to be useful for detection of preclinical prion disease in man.
Dengue viremia in blood donors from Honduras, Brazil, and Australia
Authors: Linnen Jeffrey M. , Vinelli Elizabeth , Sabino Ester C. , Tobler Leslie H. , Hyland Catherine , Lee Tzong‐Hae , Kolk Daniel P. , Broulik Amy S. , Collins Cynthia S. , Lanciotti Robert S. , Busch Michael P. 
Published: May 2008

BACKGROUND: Dengue fever and hemorrhagic disease are caused by four dengue virus (DENV) serotypes (DENV‐1 to ‐4), mosquito‐borne flaviviruses with increasing incidence, and expanding global distributions. Documented transfusion transmission of West Nile virus raised concern regarding transfusion‐transmitted DENV.METHODS: A DENV RNA assay was developed based on transcription‐mediated amplification (TMA) blood screening assays routinely used by blood centers worldwide. Sensitivity was established by endpoint dilution analyses of DENV‐1 RNA transcript and pedigreed tissue culture standards for all four DENV‐serotypes. Frozen plasma samples were tested from 2994 donations from Honduras (September 2004‐January 2005), 4858 donations from Brazil (February‐April 2003), and 5879 donations from Australia (March‐September 2003). Type‐specific polymerase chain reaction (PCR) assays were used to quantify and genotype TMA repeat‐reactive samples; viral cultures, type‐specific antibody, and antigen assays were also performed.RESULTS: The TMA assay detected 14.9 copies per mL DENV‐1 transcript (95% detection limit), with comparable sensitivity for all four serotypes. Honduran donors yielded 9 TMA repeat‐reactive samples (0.30%); 8 were confirmed by PCR, with 3 DENV serotypes detected and viral loads from fewer than 3 × 104 to 4.2 × 104 copies per mL; and 4 samples yielded infectious virus. Three (0.06%) Brazilian samples tested repeat‐reactive; 2 (0.04%) were PCR‐positive (serotypes DENV‐1 and ‐3; 12 and 294 copies/mL). No Australian donor samples tested repeat‐reactive.CONCLUSION: Dengue viremia rates among asymptomatic blood donors ranged from 0.30 percent in Honduras to 0.04 percent in Brazil. Future studies are needed to establish rates of transfusion transmission by viremic donations and clinical consequences in recipients.
The polymine spermine regulates osteogenic differentiation in adipose stem cells†
Authors: Tjabringa G.S. , Zandieh‐Doulabi B. , Helder M.N. , Knippenberg M. , Wuisman P.I.J.M. , Klein‐Nulend J. 
Published: May 2008

AbstractFor bone tissue engineering, it is important that mesenchymal stem cells (MSCs) differentiate into osteoblasts. To develop a method for differentiation of adipose tissue‐derived mesenchymal stem cells (AT‐MSCs) along the osteogenic lineage, we studied the effect of polyamines, which are organic cations implicated in bone growth and development, on differentiation of AT‐MSCs. Treatment of goat‐derived AT‐MSCs with 1,25‐dihydroxyvitamin‐D3 (1,25(OH)2D3), which stimulates osteogenic differentiation, for 7 days induced gene expression of the polyamine‐modulated transcription factor‐1 (PMF‐1) and spermidine/spermine N (1)‐acetyltransferase (SSAT), which are both involved in polyamine metabolism, suggesting that polyamines are involved in osteogenic differentiation of AT‐MSCs. Furthermore, treatment of AT‐MSCs with the polyamine spermine‐regulated gene expression of runx‐2, a transcription factor involved in early stages of osteogenic differentiation, and that of osteopontin, a bone matrix protein expressed in later stages of osteogenic differentiation. Runx‐2 gene expression was increased 4 and 14 days after a short 30 min. treatment with spermine, while osteopontin gene expression was only increased 4 days after spermine treatment. Finally, alkaline phosphatase activity, which is intimately involved in the formation of extracellular matrix of bone, was increased 4 weeks after the 30 min.‐spermine treatment of AT‐MSCs. In conclusion, this study shows for the first time that the polyamine spermine regulates differentiation of AT‐MSCs along the osteogenic lineage, which can be used as a new method for differentiation of AT‐MSCs along the osteogenic lineage. Therefore, polyamines may constitute a promising tool for bone tissue engineering approaches using AT‐MSCs, such as a one‐step surgical procedure for spinal interbody fusion.
Functional in vivo assessment of retinal artery microirregularities in glaucoma
Authors: Kotliar Konstantin E. , Nagel Edgar , Vilser Walthard , Lanzl Ines M. 
Published: May 2008

AbstractPurpose:  We investigated whether retinal branch arteries in healthy subjects, and non‐treated and treated primary open‐angle glaucoma (POAG) patients show irregular local patterns during dynamic reaction to acute increases of different magnitudes in intraocular pressure (IOP).Methods:  Nine POAG patients and nine age‐matched normal volunteers were examined with the retinal vessel analyser (RVA) using a suprasystolic IOP increase (Study 1). Fourteen POAG patients and 13 age‐matched controls were examined using a moderate IOP increase for 100 seconds (Study 2). Longitudinal arterial profiles were obtained for the chosen time intervals. The high‐frequency waviness (HFW) of these profiles was analysed quantitatively.Results:  No significant changes in HFW were found in controls in different phases of the arterial reaction. Significant increases in HFW from baseline to dilation (Study 1, P < 0.03) and from dilation to constriction (Study 2, P < 0.05) were found in POAG patients. High‐frequency waviness was higher in POAG patients than in controls during dilation (P < 0.05) in both studies.Conclusions:  Our results indicate a local vessel wall difference in glaucoma patients compared with age‐matched controls. Increasing HFW might worsen hydraulic resistance of the vessel segment to blood flow. Significant increase of arterial microirregularities in the POAG retina during vascular dilation might be an indication for vascular endothelial alterations in glaucoma, leading to impaired perfusion in response to IOP increase.
Weight gain in bipolar disorder: pharmacological treatment as a contributing factor
Authors: Torrent C. , Amann B. , Sánchez‐Moreno J. , Colom F. , Reinares M. , Comes M. , Rosa A. R. , Scott J. , Vieta E. 
Published: May 2008

Objective:  The aim of this paper was to review the association of most commonly used psychopharmacological drugs with weight gain in bipolar disorder.Method:  Information was retrieved from a PubMed/Medline literature search reviewing weight gain in pharmacological studies in bipolar disorder.Results:  Obesity and overweight in bipolar disorder are partly related to prescribed drugs with a strong effect of clozapine and olanzapine. Lesser but still relevant weight gain is caused by quetiapine, risperidone, lithium, valproate, gabapentin and by some antidepressants. Ziprasidone, aripiprazole, carbamazepine and lamotrigine do not seem to cause significant overweight.Conclusion:  Careful monitoring of weight changes in patients before and after drug prescription should be implemented in the clinical routine and drugs which potentially cause weight gain should be avoided in overweight patients with bipolar disorder. Furthermore, eating habits and daily activities should be targeted as they may also have a significant impact on overall health and weight‐related issues.
Nicotine in breast milk influences heart rate variability in the infant
Authors: Dahlström Anders , Ebersjö Christina , Lundell Bo 
Published: May 2008

AbstractAim: To study the effects of postnatal exposure to nicotine on the regulation of heart rate and blood pressure in infants.Subjects and Methods: Thirty‐eight mother–infant pairs were studied. Twenty nonsmoking and 18 smoking (2–20 cigarettes per day) mothers were included. All infants were healthy, exclusively breastfed and their postnatal age was 6 weeks. During a home visit infant's urine and mothers' milk were sampled and concentrations of nicotine and cotinine were analyzed. Infants' electrocardiogram (ECG) were recorded, sleep state documented and blood pressure during sleep was measured. Heart rate variability (HRV) was calculated with spectral analysis of R–R intervals.Results: The smoking mothers exposed their infants to nicotine in milk with a median nicotine concentration of 47 (8–192) μg/L. Analysis of infants' urine showed that the nonsmoking group had 0.8 (0–5.2) and the smoke group 60 (17–139) μg cotinine/L (p < 0.01). The frequency domain low‐to‐high frequency (LF/HF) ratio, was correlated to milk nicotine concentrations in the milk sample, from smoking mothers. HRV decreased, with increasing milk nicotine, ingested by the boys (r =−0.74, p = 0.02) but not the girls (r =−0.13, p = 0.76). The differences of mean arterial pressure between sleep states in the infants, were significantly lower in the smoke group 5.8(6.8) compared to the nonsmoke group 11.5(7.2) mmHg (p = 0.03).Conclusions: Postnatal exposure to nicotine influences autonomic cardiovascular control in infants.
Implant overdentures for edentulous elders: study of patient preference
Authors: Esfandiari Shahrokh , Lund James P. , Penrod John R. , Savard André , Mark Thomason J. , Feine Jocelyne S. 
Published: May 2008

Background:  Studies show that elders wearing implant overdentures have improved nutrition and quality of life. However, upfront costs of this therapy are high, and the income of elderly edentulous populations is low.Objectives:  This study was designed (i) to measure the preferences of edentulous patients for mandibular two‐implant overdentures using Willingness‐To‐Pay (WTP) and Willingness‐To‐Accept (WTA), (ii) to assess the effect of long‐term financing on WTP and (iii) to assess the desired role of health care plans in financing dental prostheses.Methods:  Edentulous elders (68–79 years; n = 36) wearing maxillary dentures and either a mandibular conventional denture (CD, n = 13) or a two‐implant overdenture with ball attachments (IOD, n = 23) participated in this study. All had received their prostheses 2 years previously, as part of a randomised clinical trial. A three‐part questionnaire was completed during a 20‐min interview with a trained researcher.Results:  Forty‐six per cent (6/13) of the CD wearers and 70% (16/23) of the IOD wearers were willing to pay three times more than the current cost of conventional dentures for implant prostheses. These percentages were increased to 77% (CD) and 96% (IOD) if participants could pay for implant overdentures in monthly instalments. Eighty‐six per cent (31/36) of all participants in both groups (21/23 IOD; 10/13 CD) thought that the government should cover at least some of the cost of implant overdentures.Conclusions:  This study shows that, the majority of elderly edentate individuals who have not experienced mandibular two‐implant overdenture therapy are willing to pay the cost, particularly when payment can be made in monthly instalments.
Evaluation of Vertical Head Profiles in Water Production Wells during Pumping
Authors: Boggs Kevin G. 
Published: May 2008

AbstractIn a recent field study, the performance of four production wells was evaluated. The intake of a vertical turbine test pump was set below the top of the screened interval of the wells due to anticipated drawdown. Water level sounding tubes were welded to the well casing at various depths in each well. Drawdown data collected at various depths were used to evaluate the vertical head distribution in the wells under various pumping stresses. A direct relationship was observed between the head loss and the location of the pump intake in the production wells. A vertical head profile developed, suggesting that the location of the pump intake controlled the location of water production from the aquifer. The head loss in the wells observed during pumping was directly proportional to well discharge and annulus size between the well casing and the vertical turbine pump shaft. The pressure differences that developed in the wells created increased drawdown in water level sounding tubes installed deep in the wells compared to the total drawdown observed in the production wells. Certain implications should be considered based on the evaluation of the data obtained from this study. Because water management decisions are made using well test data, the quality of the data is crucial. In instances where well performance is evaluated using water level data collected from water level sounding tubes that are located close to a pump intake (in this case deep in the well), it should be recognized that well performance could be underestimated.
Facial cooling and peripheral chemoreflex mechanisms in humans
Authors: Argacha J. F. , Xhaët O. , Gujic M. , De Boeck G. , Dreyfuss C. , Lamotte M. , Adamopoulos D. , Van De Borne P. 
Published: May 2008

AbstractAim:  Reductions in arterial oxygen partial pressure activate the peripheral chemoreceptors which increase ventilation, and, after cessation of breathing, reduce heart rate. We tested the hypothesis that facial cooling facilitates these peripheral chemoreflex mechanisms.Methods:  Chemoreflex control was assessed by the ventilatory response to hypoxia (10% O2 in N2) and the bradycardic response to voluntary end‐expiratory apnoeas of maximal duration in 12 young, healthy subjects. We recorded minute ventilation, haemoglobin O2 saturation, RR interval (the time between two R waves of the QRS complex) and the standard deviation of the RR interval (SDNN), a marker of cardiac vagal activity throughout the study. Measurements were performed with the subject’s face exposed to air flow at 23 and 4 °C.Results:  Cold air decreased facial temperature by 11 °C (P < 0.0001) but did not affect minute ventilation during normoxia. However, facial cooling increased the ventilatory response to hypoxia (P < 0.05). The RR interval increased by 31 ± 8% of the mean RR preceding the apnoea during the hypoxic apnoeas in the presence of cold air, compared to 17 ± 5% of the mean RR preceding the apnoea in the absence of facial cooling (P < 0.05). This increase occurred despite identical apnoea durations and reductions in oxygen saturation. Finally, facial cooling increased SDNN during normoxia and hypoxia, as well as during the apnoeas performed in hypoxic conditions (all P < 0.05).Conclusion:  The larger ventilatory response to hypoxia suggests that facial cooling facilitates peripheral chemoreflex mechanisms in normal humans. Moreover, simultaneous diving reflex and peripheral chemoreflex activation enhances cardiac vagal activation, and favours further bradycardia upon cessation of breathing.
Control of Aeromonas hydrophila Infection in Spotted Snakehead, Channa punctatus, by Solanum nigrum L., a Medicinal Plant
Authors: Rajendiran A. , Natarajan E. , Subramanian P. 
Published: May 2008

Abstract The present study describes the potential of black nightshade, Solanum nigrum, to control Aeromonas hydrophila infection in spotted snakehead, Channa punctatus. Similar sizes of Ch. punctatus were grouped into three categories as follows: control (injected with sterilized water), Ae. hydrophila infected + untreated, and Ae. hydrophila infected + treated with S. nigrum leaf extract. Hematological parameters (white blood cell [WBC], red blood cell [RBC], hemoglobin [Hb], and packed cell volume [PCV]) were analyzed in these fishes once every 5 d from Days 5 to 30 postexposure. Preliminary antibacterial assay reported that leaf extracted with ethyl acetate had the maximum inhibition compared to other parts of the plant (i.e., berries and whole plant) or when extracted with other solvent extracts (chloroform and ethanol). Except for WBC count, all other parameters showed a declining trend from Day 5 onward and reaching to a minimum on Day 30 in Ae. hydrophila‐infected fish, whereas the WBC count increased. The infected fish treated with S. nigrum leaf extract reported a significant reversion to normal RBC, WBC, Hb, and PCV levels and the skin ulceration recovered within a short period. The antiulcer potential of the medicinal plant as described in humans may be extended to the fish population.