bluuebunny/crossref_metadata_2025 huggingface dataset:
Levels of C-Telopeptide Fragments of Collagen Type I Enable the Monitoring and Early Adjustment of Clodronate Therapy in Patients with Postmenopausal Osteoporosis
Authors: Borean Alessio , Prà Marina De , Farina Giorgio , Nalin Paolo , Rizzotti Paolo
Published: October 2004

We monitored the efficacy of therapy with clodronate, a bisphosphonate drug, in women with postmenopausal osteoporosis, using urinary immunoenzymatic assay of C-telopeptide of collagen type I, an eight amino acid fragment (collagen fragment) of the C-telopeptide of the α1-chain of collagen type I (EKAHDGGR). The analysis of the dynamics of collagen fragment concentrations (a marker of bone resorption) during treatment suggests the possibility of early modulation and customization of therapy based on the levels of this marker. This could enable improved control over secondary effects and side effects of clodronate therapy. Pharmacologic inhibition of bone resorption by osteoclasts could be indirectly responsible for the increase in parathyroid hormone found during treatment with clodronate. Increased levels of parathyroid hormone are probably necessary to stimulate residual osteoclast activity and are sufficient for the maintenance of calcium-phosphate homeostasis in a new pharmacologically-induced equilibrium. Outside this context the levels of parathyroid hormone of certain patients would be considered pathologic.
Probable Involvement of Cathepsin D in the Degradation of β2-Microglobulin in Acidic Urine
Authors: Yamamoto Hideaki , Yamada Toshiyuki , Itoh Yoshihisa
Published: October 2004

Instability of β2-microglobulin in acidic urine was investigated by identifying an associated protease from normal urine. Degradation was completely blocked by pepstatin, an aspartic protease inhibitor, and the counterpart of the inhibitor was thus sought. The molecular weight of the counterpart was similar to that of the inhibitor, while its cleavage site on β2-microglobulin was identical in three products generated in purified β2-microglobulin in normal acidified urine (pH 5.0–5.5) and those generated by direct reaction between purified β2-microglobulin and cathepsin D in acetic acid (pH 5.0). On Western blotting, the presence of cathepsin D was demonstrated immunochemically in urine, and its urinary concentration correlated well with degree of β2-microglobulin degradation. All these findings strongly suggest that cathepsin D is a major urinary acid protease involved in the degradation of β2-microglobulin.
Autoantibodies against Oxidized Low-Density Lipoprotein Correlate with Achilles Tendon Xanthomas
Authors: Okada Masahiko , Miida Takashi , Fujiwara Akira , Inomata Noriyoshi
Published: October 2004

Although there is increasing evidence for anti-oxidized low-densitiy lipoprotein (LDL) autoantibodies in human sera, their diagnostic utility remains controversial. We examined the difference in autoantibody titers between patients with Achilles tendon xanthoma and control subjects. Fifteen hyperlipidemic patients with Achilles tendon xanthoma (group A+) and 94 hyperlipidemic patients without Achilles tendon xanthoma (group A−) were studied. Quantification of anti-oxidized LDL and anti-native LDL autoantibodies was performed using an ELISA method. To calculate antibody titers, we used the ratio between the spectrophotometric reading of anti-oxidized LDL and anti-native LDL wells. Using oxidized LDL that was purified by gel-permeation chromatography as antigen, immunoglobulin G level differed significantly between groups A+ and A− (p ＜ 0.01). In contrast, using native and oxidized LDL as antigens without chromatographical purification revealed no significant difference between the two groups. Furthermore, immunoglobulin autoantibody titer did not correlate with age, body mass index, total cholesterol, high-density lipoprotein cholesterol, LDL cholesterol, or triglyceride in the entire group of subjects. Thus, immunoglobulin G autoantibody values appear to correlate with Achilles tendon xanthoma.
Regulation of the Hepatic Endothelin System in Advanced Biliary Fibrosis in Rats
Authors: Rothermund Lars , Leggewie Stefan , Schwarz Anja , Thöne-Reinecke Christa , Cho Jae Jin , Bauer Christian , Paul Martin , Neumayer Hans-H. , Schuppan Detlef , Hocher Berthold
Published: October 2004

The aim of the present study was to analyze the hepatic endothelin system and its regulation in liver cirrhosis due to bile duct obstruction. Wistar rats were subjected for 6 weeks to: 1) sham operation; 2) bile duct obstruction; 3) bile duct obstruction and the selective oral endothelin A receptor antagonist LU 135252; 4) bile duct obstruction and oral silymarin, a hepatoprotective and antifibrotic compound. We determined tissue concentrations of endothelin-1 and big-endothelin-1 by ELISA and the density of both endothelin receptor subtypes in plasma membrane fractions by Scatchard analysis.

The hepatic endothelin system in liver cirrhosis due to chronic bile duct obstruction is characterized by a simultaneous up-regulation of both endothelin-1 tissue concentration (7.2 fold compared to sham operation; p<0.001) as well as the density of both endothelin receptor subtypes (ETA 7.4-fold, ETB 4.9-fold, p<0.001, respectively) suggesting a synergistic activation of the hepatic endothelin system in this rat model of non-inflammatory cirrhosis. Treatment with proven antifibrotic agents such as silymarin or a selective endothelin-A-receptor blocker (LU 135252) did not reduce the activity of the hepatic endothelin system, suggesting that the hepatic endothelin system is not activated by the fibrotic process itself.
The Effect of a Gender Difference in the Apolipoprotein E Gene DNA Polymorphism on Serum Lipid Levels in a Serbian Healthy Population
Authors: Stanković Sanja , Glišic Sanja , Alavanatić Dragan
Published: October 2004

To date, no data have been available on relationship between apolipoprotein E polymorphism and lipid levels in Serbian populations. Blood samples were obtained from 591 healthy normal individuals (193 women and 398 men). A 244 bp sequence of the apolipoprotein E gene including the two polymorphic sites was amplified by polymerase chain reaction. After digestion withHhal, DNA fragments were visualized by microplate array diagonal gel electrophoresis. In men, levels of both total and low-density lipoprotein cholesterol among the three apolipoprotein E genotype groups differed significantly (p <0.05). The ε2 allele was associated with lower concentrations of both total and low-density lipoprotein cholesterol, where the ε4 allele had the opposite effects. No significant effects of apolipoprotein E polymorphism on serum lipid levels were observed in women. The presented data could be taken into consideration in any future disease risk evaluation in this population.
Transformation in the PC-Aided Biochemical Data Analysis
Authors: Meloun Milan , Hill Martin , Militky Jiří , Kupka Karel
Published: October 2004

Data transformations enable expression of original data in a new scale, more suitable for data analysis. In computer-aided interactive analysis of biochemical and clinical data an exploratory data analysis often finds that the sample distribution is systematically skewed or does not accept a sample homogeneity. Under such circumstances the original data should be transformed. The power transformation and the Box-Cox transformation improve sample symmetry and also stabilize variance. Both the Hines-Hines selection graph and the plot of logarithm of a maximum likelihood function allow selection of an optimum transformation parameter. The proposed procedure of data transformation in univariate data analysis is illustrated on a determination of 17-hydroxypregnenolone in umbilical blood of a population of newborns. Lower levels of free 5-ene steroids in umbilical blood and elevated levels of 5-ene steroid sulfates indicate a congenital sex-specific placental sulfatase insufficiency. After examination of statistical assumptions by diagnostic plots of an exploratory data analysis the best estimate of a mean value of 17-hydroxypregnenolone is derived.
Sequential C3 and C4 Levels in Human Milk in Relation to Prematurity and Parity
Authors: Trégoat Virginie , Montagne Paul , Cuillière Marie-Louise , Béné Marie-Christine , Faure Gilbert C.
Published: October 2004

Similarly to many immune molecules of human milk, C3 and C4 levels decrease during lactation. We investigated the influence, over the first three weeks of lactation, of both prematurity and parity on the sequential evolution of these levels. Milk C3 and C4 concentrations were measured by immunonephelometry in 494 individual samples collected from 76 lactating mothers. C3 and C4 concentrations were higher in milk from preterm or primiparous mothers. The major differences were observed in milk from days 5–8 and 9–20, likely due to pronounced interindividual variations in levels of days 1–4 milk. Milk from mothers of precocious (33 weeks' gestation or less) preterm newborns presented higher concentrations and a slower decrease of C3 and C4 levels than that from mothers of late (33–37 weeks' gestation) preterm newborns, when compared to term mothers. Finally, the inversion of the C3/C4 ratio occuring over time, previously reported, appeared later in milk from mothers of preterm newborns. The influence of prematurity was even greater in primiparous than in multiparous mothers. Both C3 and C4 levels therefore appear to be influenced in human milk by the parity and prematurity of the delivery. Mothers from preterm newborns seem to provide higher levels of C3 for a longer period post delivery.
Measurement of Purines in Urine by Capillary Electrophoresis for Estimating the Degree of Hypoxia in Infants
Authors: Prezelj Marija , Neubauer David , Derganc Meta
Published: October 2004

We describe a simple, rapid and reproducible method for measuring hypoxanthine, xanthine and uric acid in urine samples of infants by capillary electrophoresis with an uncoated fused silica capillary and ultraviolet detection. Conditions were 40mmol/l borate buffer pH 9.4 with sodium dodecyl sulphate (0.1mol) 3s hydrodynamic load and the voltage 20kV. The calibration curves for hypoxanthine and xanthine were linear to 150μmol/l and for uric acid to 300μmol/l. The limits of detection for hypoxanthine, xanthine and uric acid were 0.5, 2.0 and 20μmol/l, respectively. Analytical recovery of the three purines ranged from 93 to 105%. Overall CVs were <5.2%. Using this method, we measured purine concentrations in the urine samples of 103 infants, divided into three groups, according to different degrees of hypoxia. There was a significant difference among the three groups only in hypoxanthine concentrations. In 35 urine samples from the control group, 43 urine samples from infants with a history of an apparent life threatening episode and in 25 urine samples from infants with infantile apnoea, the mean concentrations of hypoxanthine (mean ± SD) were 13.1 ± 4.0, 25.1 ± 8.1 and 58.2 ± 17.4 μmol/mmol creatinine, respectively. The diagnostic accuracy of the purine measurement was evaluated by receiver-operating characteristic curve analysis.
Can Age and Sex Related Reference Intervals Be Derived for Non-Healthy and Non-Diseased Individuals from Results of Measurements in Primary Health Care?
Authors: Kallner Anders , Gustavsson Elisabeth , Hendig Eva
Published: October 2004

Reference intervals in clinical chemistry are commonly based on results of measurements in reference populations or are taken from the literature. A reference population should represent a defined group of individuals and be as similar as possible to the patients under investigation. Frequently, reference populations have been recruited from institutionalised healthy young people who do not necessarily fulfill these criteria. In the present study we describe the temporal changes in 37 commonly measured quantities in men and women from childhood to late in life. The samples were collected in the primary health care and sorted according to an assumed decision by the physician. The emerging group of individuals forms a reference population that was regarded as “non-diseased” and the results of measurements in this population are reference values. A remaining group of “non-healthy” were likewise identified for comparison. The central 95 percentile was wider than those usually assigned to the quantities whereas the medians almost coincided. In the “non-healthy” group the medians were shifted in a direction that would be expected from pathophysiology aspects.
Associations of Apolipoprotein E Concentration and Polymorphism with Lipids and Apolipoprotein Levels in Chinese from Beijing and Shanghai
Authors: Xia Yongjing , Sass Catherine , Shen Xia , Siest Gérard , Visvikis Sophie
Published: October 2004

The association of apolipoprotein E concentration and common polymorphism (codons 112/158) with lipid and apolipoprotein concentrations was studied in two Chinese healthy population samples from Beijing (n=99) and Shanghai (n=67). Body mass index and apolipoproteins E and AI and triglyceride concentrations were significantly different between the two populations (0.001<p<0.05), but apolipoprotein E common allele frequencies were not significantly different. Apolipoprotein E concentration was independently associated with apolipoproteins B and AI, total cholesterol and triglyceride concentrations in the Beijing group, but only with total cholesterol and apolipoprotein AI concentrations in the Shanghai group. Apolipoprotein E polymorphism was significantly associated with apolipoproteins E and AI, and triglyceride concentrations in the Beijing subjects (0.001<p<0.01), whereas apolipoprotein E polymorphism was significantly related only to apolipoprotein E concentration in the Shanghai group (p<0.001). This preliminary study with a limited number of subjects shows that the relations between both apolipoprotein E genotypes and concentration with lipid traits are not the same in the two studied Chinese populations.
Diagnostic Value of Uric Acid to Differentiate Transudates and Exudates
Authors: Uzun Kürsat , Vural Hüseyin , Ozer Faruk , Imecik Oktay
Published: October 2004

Uric acid is known to be an end product of purine metabolism. Increases in uric acid may be found in clinical conditions associated with tissue hypoxia. We have investigated the value of uric acid to differentiate between a transudate and exudate. In this study, we measured uric acid in the pleural fluid and the serum of 110 patients, 30 women and 80 men with a mean age of 49.5±19 years. Light's criteria were used to differentiate between a transudate and exudate.

Mean serum uric acid was 496.7±153.4 μmol/l in patients with transudates and 291.3±143.1 μmol/l in patients with exudates. Mean pleural fluid uric acid was 487.7±165 μmol/l in patients with transudates and 279.9±142.1 μmol/l in patients with exudates. These data showed that the levels of serum and pleural uric acid were higher in transudates than exudates (p<0.01). However, there was no significant difference between pleural fluid/serum uric acid ratio of the two patient groups (p>0.05). The specificity and sensitivity of pleural uric acid for diagnosis of transudate effusions were 73% and 80.6%, respectively. The specificity and sensitivity of pleural uric acid for diagnosis of transudate effusions from exudates without malignancy were 71.8% and 91.7%, respectively. The sensitivity and specificity of pleural lactate dehydrogenase for diagnosis of exudates were 82% and 89%; the sensitivity and specificity of pleural fluid/serum lactate dehydrogenase were 85% and 89%; the sensitivity and specificity of pleural fluid/serum protein were 91% and 89%, respectively. Using all three of Light's criteria together, the sensitivity was 91% and its specificity was 94%.

Our findings indicate that determination of uric acid in pleural fluid may be of diagnostic value in differential diagnosis of transudates and exudates. The sensitivity of pleural uric acid measurement was higher for exudates without malignancy. However, Light's criteria remain the best means of separating transudates from exudates.
Changes of the Coagulation and Fibrinolysis System in Malignancy: Their possible Impact on Future Diagnostic and Therapeutic Procedures
Authors: Korte Wolfgang
Published: October 2004

The interaction between malignant cell growth and the coagulation and fibrinolysis system has been a well known phenomenon for decades. During recent years, this area of research has received new attention. Experimental data suggest a role for the coagulation and fibrinolysis system in tumor development, progression and metastasis. Also, clinical research suggests that targeting the coagulation system or fibrinolysis system might influence the course of malignant disease beneficially. This paper reviews data on various hemostatic and fibrinolytic parameters in malignancy; the possible use of such parameters as risk markers in oncology patients; and possible targets of anti-neoplastic therapies using anticoagulant and/or antifibrinolytic strategies. Current evidence suggests that the tissue factor/factor VIIa pathway mediates the most abundant procoagulant stimulus in malignancy via the increase in thrombin generation. Tissue factor has been suggested to mediate pro-metastatic properties via coagulation-dependent and coagulation-independent pathways; tissue factor has also been implicated in tumor neo-angiogenesis. However, so far no model has been validated that would allow the use of tissue factor in its soluble or insoluble form as a marker for risk stratification in tumor patients. On the other hand, there is now good evidence that parts of the fibrinolytic system, such as urokinase-type plasminogen activator and its receptor (“uPAR”), can be used as strong predictors of outcome in several types of cancer, specifically breast cancer. Observation of various treatment options in patients with thomboembolic disease and cancer as well as attempts to use anticoagulants and/or therapies modulating the fibrinolytic system as anti-neoplastic treatment strategies have yielded exciting results. These data indicate that anticoagulant therapy, and specifically low molecular weight heparin therapy, is likely to have anti-neoplastic effects; and that their use in addition to chemotherapy will probably improve outcome of tumor treatment in certain types of cancer. However, the body of clinical data is still relatively small and the question whether or not we should routinely consider the coagulation and/or fibrinolysis system as therapeutic targets in cancer patients is yet to be answered.
Antioxidant Status, Erythrocyte Membrane Lipid Peroxidation and Osmotic Fragility in Malignant Lymphoma Patients
Authors: Abou-Seif Mossad A.M. , Rabia Ahmad , Nasr Mohammad
Published: October 2004

We studied erythrocyte and leukocyte superoxide dismutase and catalase activities, erythrocyte malondialdehyde (MDA) and osmotic fragility and plasma L-ascorbic acid and L-dehydroascorbic acid levels in adult patients with acute lymphoblastic leukemia (ALL), Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) before and after treatment. SOD activity was elevated in leukocytes of ALL and HD patients before treatment, and borderlike-significantly elevated in leukocytes of the same patients after treatment in comparison to the control subjects. SOD activity was not changed in NHL patients before or after chemotherapy. Erythrocyte superoxide dismutase and catalase activities were elevated in the three groups of lymphomas before and after treatment. MDA level and osmotic fragility of red blood cells of patients with lymphomas were increased before and after treatment in comparison to the control group. Plasma L-ascorbic acid concentrations were decreased, whereas L-dehydroascorbic acid concentrations were increased in ALL, HD and NHL patients before and after treatment. There were also significant differences in the activities of the antioxidant enzymes, concentrations of antioxidants, MDA and osmotic fragility in the most of the malignant lymphoma patients. The present data suggest that hematological complications and autoimmune hemolytic anemia might be attributed to the oxidative stress produced by malignant lymphomas.
Determination of H+/K+-ATPase Activity in Human Gastric Biopsy Specimens
Authors: Kocsis István , Vásárhelyi Barna , Tulassay Zsolt , Szabó Teréz , Vér Ágota , Tulassay Tivadar
Published: October 2004

The aim of our work was to develop a method to determine the the H+/K+-ATPase activity of human gastric biopsy samples.

Our method is based on the phosphatase activity and the K+-induceable property of the enzyme. K+-induceable pNPPase activity was determined from homogenated corpus and antrum biopsy samples. H+/K+-ase activity was calculated as the difference between the corpus and antrum K+-induceable pNPPase activities.

Quality control measurements were done during 20 successive days from pooled homogenates. The total, between-day and between-run, within-day and within-run coefficients of variations were between 10 and 16%. The healthy mean and reference range of K+-induceable pNPPase activity in the corpus was 95.8 (95% CI: 83.4–108.2 mU/mg protein); in the antrum it was 28.3 (21.6–35.0) mU/mg protein. The calculated H+/K+-ATPase activity was 67.2 (56.9–77.5) mU/mg protein. The measured activities were independent of the age and gender.

Summarizing our results we have concluded, that our novel method might be a potential tool to gather data about the functional acid producing capability of human gastric mucosa.
European Cerebrospinal Fluid Consensus Group a TeamRoom (Lotus Notes)-Based Communication Network
Authors: Shaw Patricia , Reiber Hansotto , Brennan Christopher
Published: October 2004

A group of clinical neurochemists from all over Europe used TeamRoom to share information and to trace their discussions in a computer network. TeamRoom is a Lotus Notes based groupware tool enabling collaboration amongst geographically dispersed teams. As a result of this work a picture is emerging in the virtual TeamRoom space that represents a new kind of consensus in the use of cerebrospinal fluid analysis for diagnosis of neurological diseases. This kind of consensus differs from the conventional written report in giving a more complex and potentially richer representation of the field, in which both common views and minority perspectives are revealed. If direct access to this work is made available to other clinical neurochemists for consultation via a website, they may see their own practice in a wider context. This approach to improving different evolving traditions is more suitable for a global multicultural environment than a singular view of best practice produced by a more traditional process of group discussion. We refer to the benefits of a mixture of face to face meetings, collaboration in TeamRoom and teleconferencing for work in a non-hierarchical, multicultural and multilingual group. We suggest that the TeamRoom concept is a valuable model for enhancing self-organized harmonization across the developing European Union.
Anti-β2-Glycoprotein I ELISA: Methodology, Determination of Cut-off Values in 434 Healthy Caucasians and Evaluation of Monoclonal Antibodies as Possible International Standards
Authors: čučnik Šaa , Ambrožič Aleš , Božič Borut , Skitek Milan , Kveder Tanja
Published: October 2004

Antibodies against β2-glycoprotein I are among the most commonly detected subset of antiphospholipid antibodies. The inter-laboratory comparability of results is hardly possible due to methodological differences, lack of international standards and different cut-off values. We evaluated an ELISA for the detection of anti-β2-glycoprotein I using the analytical goals based on biological variations for similar analytes (immunoglobulins). By our ELISA we fulfilled the optimal (IgA, IgM) or minimal (IgG) analytical goals in longterm imprecision. The determination of cut-off values was based on the frequency distribution of results obtained on 434 healthy Caucasians. To aim at a better inter-laboratory comparability we tested two monoclonal antibodies as possible calibrators: HCAL (IgG) and EY2C9 (IgM). Binding properties determined by dilutional curves showed great similarities with polyclonal sera, used as in-house standards. Cut-off values were expressed by concentrations of IgG and IgM monoclonal antibodies (4.5 and 25.3 μg/l). Our study shows the possibility for a successful application of analytical goals based on biological variation even when data for a particular analyte are not available. The expression of cut-off values, obtained on a large scale Caucasian population, by the concentration of IgG and IgM monoclonal antibodies could make possible a more reliable inter-laboratory comparison of data.
Monoethanolamine (MEA) pulping of beech and spruce wood for production of dissolving pulp
Authors: Claus Iris , Kordsachia Othar , Schröder Nils , Karstens Ties
Published: October 2004

Delignification with the use of monoethanolamine (MEA) is an innovative, environmentally friendly chemical pulping process that, in contrast to conventional pulping methods, works without the use of sulphur compounds. Of particular benefit is the simple MEA recovery by distillation, allowing black liquor combustion to be dispensed with and the dissolved lignin to be gained. The MEA process is suitable for pulping both hardwood (e.g. beech) and softwood (e.g. spruce). Compared with conventional processes, the MEA process has the advantage of achieving a high degree of delignification through an increase in temperature during pulping without any appreciable damage to the cellulose. When manufacturing dissolving pulps, however, this specific selectivity of MEA requires the removal of the hemicelluloses in an additional stage, preferably by acid prehydrolysis. The conditions of this prehydrolysis step must be selected specifically to be in keeping with the ultimate use of the dissolving pulp, as this stage involves the cellulose chains being chemically attacked. The residual lignin is removed after pulping in a sequence of different bleaching stages. Substituting MEA for the sodium hydroxide solution required as a bleaching alkali in the oxygen delignification stage proves to be especially beneficial, as in this case the COD after bleaching can be considerably reduced by treating the bleaching filtrate from this stage jointly with the effluents from the MEA pulping process.
Age Differences in Search of Web Pages: The Effects of Link Size, Link Number, and Clutter
Authors: Grahame Michael , Laberge Jason , Scialfa Charles T.
Published: October 2004

Reaction time, eye movements, and errors were measured during visual search of Web pages to determine age-related differences in performance as a function of link size, link number, link location, and clutter. Participants (15 young adults, M = 23 years; 14 older adults, M = 57 years) searched Web pages for target links that varied from trial to trial. During one half of the trials, links were enlarged from 10-point to 12-point font. Target location was distributed among the left, center, and bottom portions of the screen. Clutter was manipulated according to the percentage of used space, including graphics and text, and the number of potentially distracting nontarget links was varied. Increased link size improved performance, whereas increased clutter and links hampered search, especially for older adults. Results also showed that links located in the left region of the page were found most easily. Actual or potential applications of this research include Web site design to increase usability, particularly for older adults.
Stimuli Fixation and Manual Response as a Function of Expectancies
Authors: Martens Marieke H.
Published: October 2004

Two experiments investigated effects of expectations on eye fixations and responses to expected and unexpected information in a laboratory setting. Stimulus fixation and manual responses to predefined targets among distractors were measured in a dynamic environment shown on a monitor. Participants were part of either a predictable condition (predictable sequence of targets and distractors) or a random condition. In the predictable condition, participants fixated expected distractors less than targets, with similar fixation times in the random condition. Responses to targets were faster in the predictable condition than in the random condition. Irregularities were either missed or responses were slow. This indicates that incorrect expectations may have negative consequences, with practical implications for skill-based tasks such as operator monitoring and driving. Actual or potential applications of this research include introducing operator support for tasks in which the risk of missing unexpected information or of slow responses may be dramatic.
Conversation Disrupts Change Detection in Complex Traffic Scenes
Authors: McCarley Jason S. , Vais Margaret J. , Pringle Heather , Kramer Arthur F. , Irwin David E. , Strayer David L.
Published: October 2004

A set of studies examined the effects of cognitive distraction on visual scanning and change detection in natural traffic scenes. Experiment 1 found that a naturalistic hands-free phone conversation could disrupt change detection, thereby degrading the encoding of visual information and increasing the frequency of undetected changes. Data also revealed a tendency for conversation to impair knowledge-driven orienting of attention in older adults. Experiment 2 found that an attentive listening task produced no such effects. Actual or potential applications of this research include the design of displays and interventions to minimize the effects of cognitive distraction on human performance.
Learning to Make Decisions in Dynamic Environments: Effects of Time Constraints and Cognitive Abilities
Authors: Gonzalez Cleotilde
Published: October 2004

This study investigated the effects of time constraints and cognitive abilities on dynamic decision making (DDM). The learning and performance of individuals trained in a DDM task with time constraints were compared with those who were trained without time constraints. Although all participants received the same total amount of time to perform the task, individuals under more stringent time constraints were given 3 times more practice trials on the first 2 days of the study than were people under less stringent time constraints. Despite the additional practice runs, participants under high time constraints performed worse than did participants under low time constraints on the 3rd day of the study. A subsequent analysis of cognitive abilities and decision heuristics revealed that individuals' actions corresponded with simple heuristic predictions more closely with minimal practice than with extended practice, under high rather than low time constraints, and in individuals with low rather than high cognitive abilities. These findings suggest that mere repetition of a task with less time within a trial is counterproductive to learning and that learning depends on cognitive abilities. Potential applications of this research include the design of training procedures for dynamic tasks.
Memory Processes of Flight Situation Awareness: Interactive Roles of Working Memory Capacity, Long-Term Working Memory, and Expertise
Authors: Sohn Young Woo , Doane Stephanie M.
Published: October 2004

This research examined the role of working memory (WM) capacity and long-term working memory (LT-WM) in flight situation awareness (SA). We developed spatial and verbal measures of WM capacity and LT-WM skill and then determined the ability of these measures to predict pilot performance on SA tasks. Although both spatial measures of WM capacity and LT-WM skills were important predictors of SA performance, their importance varied as a function of pilot expertise. Spatial WM capacity was most predictive of SA performance for novices, whereas spatial LTWM skill based on configurations of control flight elements (attitude and power) was most predictive for experts. Furthermore, evidence for an interactive role of WM and LT-WM mechanisms was indicated. Actual or potential applications of this research include cognitive analysis of pilot expertise and aviation training.
A New Model of Scheduling in Manufacturing: Tasks, Roles, and Monitoring
Authors: Jackson Sarah , Wilson John R. , MacCarthy Bart L.
Published: October 2004

For over 3 decades there was a belief that computer-based solutions would "solve" complex industrial scheduling problems, yet most manufacturing organizations still require human contributions for effective scheduling performance. We present a new model of scheduling for the development and implementation of effective scheduling systems within manufacturing companies. The model derives from investigating the work of 7 schedulers in 4 manufacturing environments using a qualitative field study approach, for which novel field-based data collection and analysis methods were developed. The results show that scheduling in practice comprises task, role, and monitoring activities and that the business environment influences a scheduler at work. A new definition of scheduling is presented that includes the significant facilitation and implementation aspects of human scheduling ignored by many computer-based scheduling approaches. The implications for this model extend across the domains of human factors and operations management, especially for the analysis and improvement of existing and new production planning and control processes and enterprise information systems. Actual or potential applications of this research include the analysis, design, and management of planning, scheduling, and control processes in industry; the selection, training, and support of production schedulers; and the allocation of tasks to humans and computer systems in industrial planning, scheduling, and control processes.
Histologic Evaluation of an Immediately Loaded Titanium Implant Retrieved from a Human After 6 Months in Function
Authors: Degidi Marco , Scarano Antonio , Piattelli Maurizio , Piattelli Adriano
Published: October 2004

Clinical and histologic studies have demonstrated that immediate loading can be successfully used in implant dentistry. Many factors are thought to be of importance in obtaining mineralized tissues at the interface. This study describes the implant interface of an immediately loaded implant with a conical implant-abutment connection that had been inserted in the posterior mandible for 6 months. Histology showed that mineralized tissue was present at about 74% ± 6% of the implant interface. No gaps, fibrous tissue, or inflammatory infiltrate were present at the interface. The bone adjacent to the implant was mainly lamellar (90% ± 4.5%). Tetracycline was used to label trabecular bone, and labeled bone was found in direct contact with the implant surface. The extensive labelling by tetracycline demonstrated a large quantity of newly formed bone at the implant interface. The distance between the 2 lines marked by tetracycline was 85 ± 5 mm. The results of this study show that immediately loaded dental implants can form mineralized tissues at the bone-implant interface.
Biomaterials, Biomechanics, Tissue Healing, and Immediate-Function Dental Implants
Authors: Lemons Jack E.
Published: October 2004

Selected factors and opinions are reviewed specific to immediate function of dental implants in terms of biomaterial and biomechanical properties and how they might influence postsurgical tissue healing. Comparisons are made among plate, rod, and screw vs plateau, finn, and porous geometry endosteal dental-implant designs with and without alterations in device body-surface microchemistry and microtopography. Available information introduces more questions than answers, and recommendations are made for ongoing studies of bone responses specific to the implant fit and fill parameters focused on the kinetics of postsurgical osteotomy healing and applied loading. The clinical literature supports opportunities for immediate function; however, proposals about pathways for bone healing need further investigation. The current trends within the discipline of implant dentistry offer opportunities to reevaluate current vs previous immediate-function systems.
Glasgow Aneurysm Score as a predictor of immediate outcome after surgery for ruptured abdominal aortic aneurysm
Authors:   Finnvasc Study Group, Korhonen S J , Ylönen K , Biancari F , Heikkinen M , Salenius J-P , Lepäntalo M
Published: October 2004

Background

The aim of the study was to assess the value of the Glasgow Aneurysm Score in predicting postoperative death after repair of a ruptured abdominal aortic aneurysm (AAA).

Methods

Between 1991 and 1999, 836 patients underwent surgery for ruptured AAA. Their operative risk at presentation was evaluated retrospectively using the Glasgow Aneurysm Score, based on data from the nationwide Finnvasc registry.

Results

The operative mortality rate was 47·2 per cent (395 of 836); 164 patients (19·6 per cent) had cardiac complications and 164 (19·6 per cent) required intensive care treatment for more than 5 days. Predictors of postoperative death in univariate analysis were: coronary artery disease (P = 0·005), preoperative shock (P < 0·001), age (P < 0·001), and the Glasgow Aneurysm Score (P < 0·001). In multivariate analysis the predictors were: preoperative shock (odds ratio (OR) 2·13 (95 per cent confidence interval (c.i.) 1·45 to 3·11); P < 0·001) and the Glasgow Aneurysm Score (for an increase of ten units: OR 1·81 (95 per cent c.i. 1·54 to 2·12); P < 0·001). Receiver–operator characteristic (ROC) curves showed that the best cut-off value of the Glasgow Aneurysm Score in predicting postoperative death was 84 (area under the curve 0·75 (95 per cent c.i. 0·72 to 0·78), standard error 0·17; P < 0·001). The operative mortality rate was 28·2 per cent (114 of 404) in patients with a Glasgow Aneurysm Score of 84 or less, compared with 65·0 per cent (281 of 432) in those with a score greater than 84 (P < 0·001).

Conclusion

The Glasgow Aneurysm Score predicted postoperative death after repair of ruptured AAA in this series.
Randomized clinical trial of intraoperative autotransfusion in surgery for abdominal aortic aneurysm
Authors: Mercer K G , Spark J I , Berridge D C , Kent P J , Scott D J A
Published: October 2004

Background

Perioperative homologous blood transfusion (HBT) is associated with adverse reactions and risks transmission of infection. It has also been implicated as an immunosuppressive agent. Intraoperative autotransfusion (IAT) is a potential method of autologous transfusion.

Methods

This was a single-centre randomized clinical trial of IAT in surgery for abdominal aortic aneurysm. Forty patients were randomized to IAT and 41 underwent surgery with HBT only. Patients in both groups received HBT to maintain haemoglobin levels above 8 g/dl. Transfusion requirements, and incidence of systemic inflammatory response syndrome (SIRS) and infection, were compared.

Results

Significantly fewer patients in the IAT group required HBT (21 versus 31; P = 0·038) and the median blood requirement per patient was 2 units lower (P = 0·012). There was a higher incidence of chest infection (12 versus four patients; P = 0·049) and SIRS (20 versus nine patients; P = 0·020) in the HBT group. Risk of SIRS was related to aortic cross-clamp time in the IAT group only.

Conclusion

Use of autotransfusion effectively reduced the need for HBT and was associated with a reduced incidence of postoperative SIRS and infective complications.
Synthesis and Applications of OligonucleotideCarbohydrate Conjugates
Authors: Zatsepin Timofei S. , Oretskaya Tatiana S.
Published: October 2004

Nowadays, oligonucleotidecarbohydrate conjugates are used in antisense biotechnology and in the study of glycosylated DNA functioning in vitro. The application of mono‐ and disaccharide phosphoramidites, solid‐phase supports with immobilized carbohydrates, glycosylated nucleoside phosphoramidites, and postsynthetic conjugation of reactive sugar derivatives with oligonucleotides for preparation of oligonucleotidecarbohydrate conjugates have been systematically studied. The advantages and disadvantages of these approaches are considered. Possible strategies for synthesis of glycoclusters with different topologies conjugated to DNA are discussed. Applications of oligonucleotidecarbohydrate conjugates are highlighted. Studies of interactions of glycosylated oligonucleotides with proteins and effective cell‐specific delivery of oligonucleotidecarbohydrate conjugates are discussed.
Stereo‐ and Biochemical Profiles of the 5‐6‐ and 6‐6‐Junction Isomers of α‐D‐Mannopyranosyl [60]Fullerenes
Authors: Nishida Yoshihiro , Mizuno Akiko , Kato Haruhito , Yashiro Arihiro , Ohtake Tomoyuki , Kobayashi Kazukiyo
Published: October 2004

The 5‐6‐ and 6‐6‐junction isomers of α‐D‐mannopyranosyl [60]fullerene were studied by means of circular dichroism (CD), deuterium labeling, 1H‐NMR, molecular‐dynamics (MD) calculations, and a lectin‐binding assay. The CD spectra of the O‐acetylated derivatives allowed clear discrimination of the isomers, while the 1H‐NMR spectra, with assistance from deuterium labeling and MD calculations, served to disclose the unique conformation and molecular geometry of each acetylated isomer in chloroform solution. The deprotected 5‐6‐ and 6‐6‐isomers, which gave colloidal suspensions in aqueous mixtures, displayed marked activity in blocking lectin‐induced hemagglutination by concanavalin A.
Oldhamiphylline A: a Novel Hexacyclic Alkaloid from Daphniphyllum oldhami
Authors: Chen Xin , Zhan Zha‐Jun , Yue Jian‐Min
Published: October 2004

A novel Daphniphyllum alkaloid, oldhamiphylline A (1), together with five known alkaloids, deoxycalyciphylline B, deoxyisocalyciphylline B, calyciphylline, secodaphniphylline, and calycicine A, was isolated from the leaves of Daphniphyllum oldhami. The structure of 1 was established by spectroscopic methods, especially 2D NMR techniques (1H,1H‐COSY, HMQC, HMBC, and NOESY).
A New Type of Floral Oil from Malpighia coccigera (Malpighiaceae) and Chemical Considerations on the Evolution of Oil Flowers
Authors: Seipold Lars , Gerlach Günter , Wessjohann Ludger
Published: October 2004

New, partially acetylated dihydroxy fatty acids could be identified in the floral oil of Malpighia coccigera (Malpighiaceae): 7‐OAc,3‐OH 20 : 0, 7‐OAc,3‐OH 22 : 0, 9‐OAc,3‐OH 22 : 0, 9‐OAc,5‐OH 22 : 0, 3,9‐diOAc 22 : 0, 9‐OAc,3‐OH 24 : 0, and 11‐OAc,5‐OH 24 : 0. The substitution patterns of all hitherto undescribed dihydroxylated and additionally identified monohydroxylated fatty acids are in agreement with a polyketide analogous biosynthesis. Intermediates may be 3‐acetoxy fatty acids (C16, C18, and C20), known from flower secretions of other phylogenetically unrelated plant families. A possible relationship between plant epicuticular wax and floral oil biosynthesis is discussed. It may explain why an independent but convergent development of oil flowers and flower oils in unrelated plant families was possible.
Isomeric Eremophilane Lactones from Senecio tsoongianus
Authors: Zhao Yu , Jiang Hao , MacLeod Murray , Parsons Simon , Rankin David W. H. , Wang Peng , Cheng Christopher H. K. , Shi Hao , Hao Xiaojiang , Guéritte Françoise
Published: October 2004

From the whole plant of Senecio tsoongianus, two pairs of epimers, tsoongianolides A (1) and B (2), and tsoongianolides C (3) and D (4), and two new sesquiterpene lactones, tsoongianolides E (5) and F (6), all of which possess the eremophilane skeleton, were isolated. Two known eremophilane dimers (7) and (8) were also obtained from this species. Their absolute structures were elucidated by 1D‐ and 2D‐NMR techniques and by X‐ray diffraction studies, along with chemical evidence.
Post‐Impact Assessment of Oil Pollution in Agbada West Plain of Niger Delta, Nigeria: Field Reconnaissance and Total Extractable Hydrocarbon Content
Authors: Osuji Leo C. , Adesiyan S. O. , Obute G. C.
Published: October 2004

Typical post‐impact assessment of an oil‐spill‐impacted site in Agbada west plain of the Niger Delta basin of Nigeria was carried out 13 months after recorded incidence of spillage, using empirical indices of reconnaissance and extractable hydrocarbon content. Field‐reconnaissance surveys revealed lower species' numbers and diversity of surface and subterranean flora and fauna. The presence and absence of such plant species as Elaeis guineensis, Musanga cecropiodes, and Andropogon gayanus, as well as animal species like earthworms and nematodes in sampled plots, corroborated the evidence provided by the total extractable hydrocarbon content (of (2.53±0.43)×102 mg/kg and (2.00±0.76)×102 mg/kg at surface and subsurface depths, resp.) on the level of degradation and/or regeneration at the polluted site. The most important evidence that oiling must have been responsible, at least in part, for the reduction in species' number and diversity was provided by the plant cover, Andropogan gayanus, which occurred at a lower density of 0.9 plants/m2 in the oil‐impacted plots and 14.00 plants/m2 in the unimpacted reference plots of an adjacent, geographically similar area. The presence of this species on site thus presented a significant difference (P<0.05) of over 85%, and indicated exhaustion or impoverishment of impacted soils. Elaeis guineensis, with a population density of 0.1 stands/m2, provided evidence of past cultivation on site, while species like Musanga cecropioides, with a density of 0.5 stands/m2, at the unimpacted site, confirmed the abandonment of the farmstead over a long period of time. For the fauna, the most sensitive indicator of hydrocarbon toxicity was provided by nematode Xiphinema sp. that were completely absent in the oil‐impacted site.
Chemistry and Biodiversity
Authors: Schwabe Christian
Published: October 2004

Complex structures produced by noncatalyzed multi‐step chemical processes must have highly probable origins and assembly routes. Within any frame of reference, life is easily the most‐complex self‐assembled structure known to man. It is not possible to calculate a finite time for biogenesis by statistical mechanics, but the abundance of life makes it reasonable to propose an accelerating principle of nature that naturally shortened the time for cell formation to a billion years or less. This hypothetical principle, which I have called valence‐orbital bias, is thought to be responsible for the discrepancy between statistics and observation, and carries with it, as a conditio sine qua non, multiple origins of life.

The new concept resolves the differences between the predictions based on statistical mechanics and the relatively rapid appearance of life during the post‐accretion period. It suggests as well that species and variants, the units of propagation, may also have been the units of evolution. Produced in profusion by chemistry, the origins are culled by natural selection, whereby failure means extinction, not adaptation. Biodiversity, thus, becomes a direct consequence of chemistry without positive feedback from the environment and without a constructive role for mutation.