bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chilean high‐altitude hot‐spring sinters: a model system for UV screening mechanisms by early Precambrian cyanobacteria
Authors: PHOENIX V. R. , BENNETT P. C. , ENGEL A. S. , TYLER S. W. , FERRIS F. G. 
Published: March 2006

ABSTRACTBefore the build‐up of stratospheric ozone, Archean and early Proterozoic phototrophs existed in an environment subjected to highly elevated levels of ultraviolet (UV) radiation. Therefore, phototrophic life would have required a protective habitat that balanced UV attenuation and photosynthetically active radiation (PAR) transmission. Here we report on aspects of the phototroph geomicrobiology of El Tatio geothermal field, located at 4300 m in the Andes Mountains of northern Chile (22 °S), as an analogue system to early Precambrian environments. El Tatio microbes survive in a geochemical environment of rapidly precipitating amorphous silica (sinter) and unusually high solar radiation (including elevated UV‐B flux) due to the high‐altitude, low‐latitude location. Cyanobacteria produce 10‐mm‐thick surface mats containing filaments encased in amorphous silica matrices up to 5 µm thick. Relative radiation absorbance of these silica matrices was UV‐C > UV‐B > UV‐A > PAR, suggesting the silica provides a significant UV shield to the cyanobacteria. Cyanobacteria also occur in cryptoendolithic communities 1–10 mm below siliceous sinter surfaces, and in siliceous stromatolites, where viable cyanobacteria are found at least ∼10 mm below the sinter surface. UV‐B was dramatically attenuated within ∼1 mm of the sinter surface, whereas UV‐C (a frequency range absent today but present in the early Precambrian) was attenuated even more efficiently. PAR was attenuated the least, and minimum PAR levels required for photosynthesis penetrated 5–10 mm into the sinter. Thus, a favourable niche occurs between approximately 1–10 mm in siliceous sinters where there is a balance between PAR transmission and UV attenuation. These deposits also would have strongly attenuated Archean and early Precambrian levels of UV and thus, by analogy, cyanobacteria of early Precambrian shallow aquatic environments, inhabiting silicified biofilms and silica stromatolites, would have similarly been afforded protection against high‐intensity UV radiation.
Comparison of the effects of aprotinin and tranexamic acid on blood loss and red blood cell transfusion requirements during the late stages of liver transplantation
Authors: Ickx Brigitte E. , Van Der Linden Philippe J. , Melot Christian , Wijns Walter , De Pauw Luc , Vandestadt Jean , Hut Florence , Pradier Olivier 
Published: March 2006

BACKGROUND:  During liver transplantation (LT), profound activation of the fibrinolytic system can contribute significantly to perioperative bleeding. Prophylactic administration of antifibrinolytic agents has been shown to reduce blood loss and the need for allogeneic transfusion in these conditions.STUDY DESIGN AND METHODS:  This prospective randomized trial included 51 cirrhotic patients undergoing LT. Patients were randomly assigned to receive either 280 mg of aprotinin (AP) followed by 70 mg per hour or 40 mg per kg tranexamic acid (TA) followed by 40 mg per kg per hour, administered from the end of the anhepatic phase until 2 hours after reperfusion of the graft, and the effects on blood loss and red blood cell (RBC) transfusion requirements were compared. Transfusion policy was standardized in all patients. In addition, the biological effects of the two drugs, as assessed by coagulation and fibrinolytic markers obtained during surgery, were evaluated in a subgroup of patients from each treatment group and compared with an historical control group that did not receive antifibrinolytic drugs.RESULTS:  There was no significant difference between the two groups in perioperative blood losses (AP, 6200 [4620‐8735] mL; TA, 5945 [4495‐8527] mL; median [range]) or in RBC transfusions requirements (AP, 9 [6.75‐15.25] units; TA, 10 [6.5‐13.5] units). Inhibition of fibrinolysis was observed with both drugs compared with the control group. Coagulation appeared to be activated more with AP, however, whereas fibrinolysis was inhibited more by TA.CONCLUSION:  Blood losses and RBC transfusion requirements were comparable regardless of the drug administered. TA may be as valuable as AP for controlling fibrinolysis in LT.
Left Ventricular Lead Proximity to an Akinetic Segment and Impact on Outcome of Cardiac Resynchronization Therapy
Authors: ARZOLA‐CASTANER DANIEL , TAUB CYNTHIA , KEVIN HEIST E. , FAN DALI , HAELEWYN KYLE , MELA THEOFANIE , PICARD MICHAEL H. , RUSKIN JEREMY N. , SINGH JAGMEET P. 
Published: March 2006

Background: Previous studies report that the optimal pacing site for cardiac resynchronization therapy (CRT) is along the left ventricular (LV) lateral and postero‐lateral (PL) wall. However, little is known regarding whether pacing over an akinetic site impacts the contractile response and long‐term outcome from CRT. Methods and Results: A total of 38 patients with ischemic cardiomyopathy were studied for their acute hemodynamic and 12‐month clinical response to CRT. The intraindividual percentage change in dP/dt (%ΔdP/dt), over baseline, was derived from the mitral regurgitation (MR) Doppler profile with CRT on versus off. Two‐dimensional echocardiography was used for myocardial segmentation and determinination of akinetic sites. LV lead implant site was determined using angiographic and radiographic data and categorized as being “on” (group 1) or “off” (group 2) an akinetic site. Long‐term response was measured as a combined endpoint of hospitalization for heart failure and/or all cause mortality at 12 months. Time to primary endpoint was estimated by the Kaplan‐Meier method. Clinical characteristics and acute hemodynamic response was similar in both (group 1 [n = 14]; %ΔdP/dt 48.8 ± 67.4% vs group 2 [n = 24]; %ΔdP/dt 32.2 ± 40.1%, P = 0.92). No difference in long‐term outcome was observed (P = 0.59). In contrast, lead placement in PL or mid‐lateral (ML) positions was associated with a better acute hemodynamic response when compared to antero‐lateral (AL) positions (PL, %ΔdP/dt 45.7 ± 50.7% and ML, %ΔdP/dt 45.1 ± 58.8% vs AL, %ΔdP/dt 2.9 ± 30.9%, respectively, P = 0.014). Conclusion: LV lead proximity to an akinetic segment does not impact acute hemodynamic or 12‐month clinical response to CRT.
The Relationship Between Heart Rate Recovery and Heart Rate Variability in Coronary Artery Disease
Authors: Evrengul Harun , Tanriverdi Halil , Kose Sedat , Amasyali Basri , Kilic Ayhan , Celik Turgay , Turhan Hasan 
Published: March 2006

Background: Reduced heart rate recovery (HRR) in coronary artery disease (CAD) is predictive of increased cardiovascular mortality and is related to reduced parasympathetic tonus. Objective: To investigate HRR and heart rate variability (HRV) measured at steady state condition and the relationship between these two parameters in CAD. Materials and Methods: In our study, we enrolled 33 (28 males, mean age 52.4 ± 9.6 years) patients with CAD who did not have heart failure, atrial fibrillation, pacemaker, and any disease state that could affect the autonomic functions and 38 age‐matched healthy subjects (21 males, mean age 48.3 ± 7.8 years). All the patients underwent submaximal treadmill exercise testing (Bruce protocol). HRR was calculated by subtracting the heart rate values at the 1st, 2nd, and 3rd minutes of the recovery phase from the peak heart rate (HRR1, HRR2, HRR3). Before exercise testing, short‐term steady state HRV analyses of all subjects were obtained with the time‐ and frequency‐domain methods and were correlated to HRR. For frequency‐domain analysis, low‐frequency HRV (LF, 0.004–0.15 Hz), high‐frequency HRV (HF, 0.15–0.5 Hz), and LF/HF ratio were measured for 5 minutes in the morning. For time‐domain analysis, standard deviation of the normal‐to‐normal NN intervals (SDNN), square root of the mean squared differences of successive N‐N intervals (RMSSD), and proportion derived by dividing the number of interval differences of successive N‐N intervals greater than 50 ms by the total number of N‐N intervals (pNN50) were obtained. Only HRR3 was used for the correlation analysis. Results: In CAD groups, the HF, an indicator of parasympathetic activation, was significantly reduced, whereas the LF and LF/HF values, which are indicators of sympathetic activity, were increased (P = 0.0001 for each parameter). The time‐domain parameters SDNN, RMSSD, and pNN50 were significantly reduced in the patient group (P = 0.0001, P = 0.009, and P = 0.0001, respectively). Similar to the HRV parameters, the HRR1, HRR2, and HRR3 values were significantly reduced in the patient group (P = 0.0001 for each parameter). We observed a significant negative correlation between HRR3 and LF (r =−0.67, P = 0.0001) and between HRR3 and LF/HF (r =−0.62, P < 0.0001), while there was a significant positive correlation between HRR3 and HF, SDNN, RMSSD, and pNN50 (r = 0.69, P = 0.0001; r = 0.41, P = 0.0001; r = 0.31, P = 0.008; and r = 0.44, P = 0.0001). Conclusions: HRR and HRV are significantly reduced in CAD. The reduction in HRR is parallel to the changes in HRV parameters. HRR, which can be measured easily in the recovery phase of exercise testing, can be used to detect the depression of parasympathetic tonus and to evaluate the basal autonomic balance in this patient group.
Intradialytic complications during hemodialysis
Authors: DAVENPORT Andrew 
Published: March 2006

AbstractWith the advent of developments and advances in hemodialysis machine technology, dialysate water purification, and dialyzers, the clinical spectrum of intradialytic complications has changed over the decades. In the pioneering days of hemodialysis, patients could develop allergic reactions to dialyzer membranes, sterilizing and reprocessing agents, coupled with machines that could not accurately control ultrafiltration rates, and chemically and bacterially contaminated dialysate. Whereas today, although cardiovascular problems remain the most common intradialytic complication, these are mainly due to the time restraints of trying to cope with excessive dialytic weight gains and achieve target dry weight on a thrice weekly schedule, coupled with an aging elderly dialysis population with increasing co‐morbidity.
IgG‐Antiphospholipid Antibodies in Follicular Fluid of IVF‐ET Patients are Related to Low Fertilization Rate of Their Oocytes
Authors: Matsubayashi Hidehiko , Sugi Toshitaka , Arai Tadashi , Shida Masako , Kondo Akane , Suzuki Takahiro , Izumi Shun‐ichiro , McIntyre John A. 
Published: March 2006

ProblemPatients undergoing in vitro fertilization and embryo transfer (IVF‐ET) failures show an increased incidence of antiphospholipid antibodies (aPL) in their blood. The physiological manifestations of aPL in this patient group are nonetheless controversial. Pathological effects of aPL on embryos in vitro have been documented. We questioned whether aPL if found in follicular fluids (FFs) could result in embryonic damage.Method of studyBlood from 44 patients with three or more IVF‐ET failures were tested by enzyme‐linked immunosorbent assays (ELISA) for the presence of immunoglobulin (Ig)G, IgM and IgA aPL. Both the 29 aPL‐positive and 15 aPL‐negative patients gave permission for FF collection during their next IVF‐ET attempt for additional aPL determinations.ResultsPatients with no aPL in their blood, had no aPL in their FFs. Patients with IgG and/or IgM aPL in their blood had IgG but not IgM in their respective FFs.ConclusionsThe presence of IgG aPL in FFs and increased infertility length were significantly related to lower fertilization rates, independently. Follicular fluid IgG aPL appears as a risk factor in association with successful IVF‐ET outcomes.
Multiple Thrombophilic Gene Mutations Rather than Specific Gene Mutations are Risk Factors for Recurrent Miscarriage
Authors: Coulam Carolyn B. , Jeyendran Rajasinqam S. , Fishel Laurence A. , Roussev Roumen 
Published: March 2006

ProblemRecurrent miscarriage is a heterogeneous condition. While the role of acquired thrombophilia has been accepted as an etiology of recurrent miscarriage, the contribution of specific inherited thrombophilic genes to this disorder has remained controversial. We compared the prevalence of 10 thrombophilic gene mutations among women with a history of recurrent miscarriages and fertile control women.Method of studyA total of 150 women with a history of two or more recurrent pregnancy losses and 20 fertile control women with no history of pregnancy losses had buccal swabs taken for DNA analyses of 10 gene mutations [factor V G1691A, factor V H1299R (R2), factor V Y1702C, factor II prothrombin G20210A, factor XIII V34L, β‐fibrinogen −455G>A, PAI‐1 4G/5G, HPA1 a/b (L33P), MTHFR C677T, MTHFR A1298C]. The prevalence of these mutations was compared between women experiencing recurrent miscarriage and controls.ResultsNo differences in the frequency of specific gene mutations were detected when women with recurrent miscarriage were compared with control women. However, the prevalence of homozygous mutations and total gene mutations among patients with recurrent miscarriage was significantly higher than among controls. Homozygous mutations were found in 59% of women with a history of recurrent pregnancy loss contrasted to 10% of control women. More than three gene mutations among the 10 genes studied were observed in 68% of women with recurrent miscarriage and 21% of controls.ConclusionInherited thrombophilias are associated with recurrent miscarriage. This association is manifest by total number of mutations rather than specific genes involved.
Uterine (CD56+) Natural Killer Cells Recruitment: Association with Decidual Reaction Rather than Embryo Implantation
Authors: Ordi Jaume , Casals Gemma , Ferrer Berta , Creus Montserrat , Guix Cristina , Palacín Antonio , Campo Elias , Balasch Juan 
Published: March 2006

ProblemWhether decidual leukocyte recruitment and/or increase is primarily hormonally regulated or induced mainly by blastocyst implantation is a matter of debate. Thus, this study investigated the number and distribution of leukocyte populations, with emphasis on natural killer (NK) cells of uterine and peripheral type, within decidual tissue from women with decidualized endometrium both related and unrelated to pregnancy and those with ectopic decidua associated with intrauterine pregnancy, as well as in tubal implantation sites.Method of studyImmunohistochemical characterization of immune cells using antibodies to CD3, CD4, CD8, CD20, CD68, CD16, CD56, CD57, in formalin‐fixed, paraffin‐embedded tissue, and a quantitative analysis of these subpopulations was conducted in tissue blocks from four groups of patients: (i) 20 women with decidualized endometrium due to progestin therapy (i.e. not associated with gestation) (group Prog‐D); (ii) 20 women with intrauterine pregnancy‐associated ectopic decidua (seven in the Fallopian tube, five in the ovary, five in the uterine cervix, and three in the omentum) (group Ect‐D); (iii) 20 women with spontaneous abortion who had an histologic sample of the decidua at the uterine implantation site (group Uter‐D); and (iv) 20 consecutive patients who had had an ectopic tubal pregnancy (group Tub‐Preg). Twenty gynecologic specimens with marked inflammatory reaction were used as controls (group Con).ResultsCD3+, CD4+, CD8+, CD68+ cells were detected in all tissue samples investigated. In contrast, CD20+ cells were detected in all samples in group Con, but only in 75%, 25%, 55% and 70% of groups Prog‐D, Ect‐D, Uter‐D and Tub‐Preg, respectively. In all tissue samples investigated, CD57+ and CD16+ cells were detected. Conversely, CD56+ cells were completely absent in 15 of 40 cases (37.5%) lacking decidual reaction (group Tub‐Preg, 7/20; group Con, 8/20) but were present in all cases showing decidual reaction. In contrast with CD56+ cells, CD57+ NK cells were more abundant in group Con than in the four study groups.ConclusionsCD56+ NK cells are closely related to decidua irrespective of its eutopic or ectopic location rather than to the implantation site. This suggests that the recruitment and/or increase of uterine NK cells into the uterus is not dependent on the physical presence of an implanting embryo but instead is controlled hormonally.
Structure, function and disease susceptibility of the bovine major histocompatibility complex
Authors: TAKESHIMA Shin‐Nosuke , AIDA Yoko 
Published: March 2006

ABSTRACTThe major histocompatibility complex (MHC) of cattle is known as the bovine leukocyte antigen (BoLA) and is located on chromosome 23. BoLA has been linked to variation in resistance to disease including bovine leukemia virus‐induced lymphoma and mastitis. Moreover, BoLA appears to influence other traits such as milk yield, growth and reproduction, which are not often measured in humans, and variations in individual immune response to antigen. The BoLA appears to be organized in a similar way to the MHC region in humans, but there are notable differences. A major rearrangement within the class II region has led to the division of the BoLA into two distinct subregions of chromosome 23 separated by about a third of the chromosome’s length. The class IIa subregion contains functionally expressed DR and DQ genes, while the class IIb subregion contains the genes of undefined status such as DYA, DYB, DMA, DMB, DOB, DOA, TAP1, TAP2, LAP2 and LMP7. In addition, one pair of human class II genes (DP) does not appear to have an equivalent in cattle, and there is one pair of DY genes that seem to be found only cattle, sheep and goats. In humans, three classical, polymorphic class I genes (HLA‐A, ‐B and ‐C ) are each present on all haplotypes. However, in cattle, none of the four (or more) classical class‐I genes identified are consistently expressed, and haplotypes differ from one to another in both the gene number and composition. These variations in both class I and II are likely to play an important role in cattle immune responses. This review summarizes current knowledge of the structural and functional features and disease association of BoLA genes.
Comparative genomics of the poultry major histocompatibility complex
Authors: SHIINA Takashi , HOSOMICHI Kazuyoshi , HANZAWA Kei 
Published: March 2006

ABSTRACTThis review summarizes the latest findings regarding the avian major histocompatibility complex (MHC), focusing particularly on the genomics of MHC in the Japanese quail (Cotrnix japonica) and other birds, as well as haplotype, genomics, function and disease resistance in the chicken (Gallus gallus). This information provides important insight into the breeding of disease resistance in poultry, natural selection of disease resistance in wild birds, and the effects of recombination and hitchhiking on the evolution of multiple MHC gene families.
Synergistic fibrolysis in the rumen by cellulolytic Ruminococcus flavefaciens and non‐cellulolytic Selenomonas ruminantium: Evidence in defined cultures
Authors: SAWANON Suriya , KOBAYASHI Yasuo 
Published: March 2006

ABSTRACTTo investigate the rumen bacterial interaction between cellulolytic Ruminococcus flavefaciens and non‐cellulolytic Selenomonas ruminantium, fiber digestibility and fermentation products were determined in defined cultures consisting of these two species. Avicel, orchardgrass hay, rice straw and alfalfa hay were used as substrates for 72 h incubation to monitor digestibility, volatile fatty acids, succinate, lactate and bacterial number. In monoculture, R. flavefaciens digested the fiber sources at 21–32%, while S. ruminantium strains did not. When R. flavefaciens was cocultured with one of three different strains (GA192, S137 and S150) of S. ruminantium, fiber digestion exceeded the value recorded by R. flavefaciens alone. In particular, cocultures with S. ruminantium S137 showed significantly higher digestibility for all the fiber sources than R. flavefaciens alone (P < 0.05). Propionate production and growth of S. ruminantium was notable in all cocultures but not in monocultures. Succinate was accumulated in monoculture of R. flavefaciens, while the accumulation was not observed in cocultures. These results indicate that R. flavefaciens provides fiber hydrolysis products to S. ruminantium as growth substrates. In addition, S. ruminantium could activate R. flavefaciens by rapidly consuming the products. Such cross‐feeding between cellulolytic and non‐cellulolytic bacteria could enhance fiber digestion, although the extent of the enhancement may depend on strain combinations.
Feed intake, lactation performance, blood metabolites and fertility in early lactation dairy cows grazing a timothy pasture
Authors: OHGI Tsutomu , HARA Satoshi , OZEKI Tadao , FUJITA Mamiko , SAKAI Osamu , KASHUYA Hirotaka , DOUKOSHI Akira , NISHIMURA Kazuyuki 
Published: March 2006

ABSTRACTThe present study was conducted to investigate feed intake, milk yield, milk composition, blood metabolites and fertility in early lactation dairy cows grazing a timothy pasture. Fourteen multiparous Holstein cows that calved between 20 May and 19 July were used over a 3‐year period. The stocking rate was 3.6–4.3 cow/ha. Concentrates were fed separately at 9.5–11.5 kg/day per cow (dry matter basis) from 1 to 13 weeks postparturition. Herbage intake was estimated using chromium oxide as an indigestible marker. The mean contents of crude protein, total digestible nutrients and neutral detergent fiber of pasture during the 3‐year study period were 22.3%, 71.8% and 51.7%, and those of total diet were 18.9%, 77.3% and 40.3%, respectively. The mean herbage dry matter intake was 13.0 kg/day from 2 to 13 weeks postparturition during the study, total dry matter intake was 23.7 kg/day, the total digestible nutrients sufficiency rate was 105%, milk yield was 39.7 kg/day, and milk fat percentage was 3.30%. The decrease in bodyweight postparturition was slight. Urea nitrogen concentrations in serum were below 18.3 mg/dL. The mean days to first estrus and days open were 36 and 104 days, respectively. These results indicate that energy deficiency, decrease in bodyweight and fertility in early lactation barely occur when high producing dairy cows are fed enough grazing grass and suitable concentrates.