bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical Implications of Obesity With Specific Focus on Cardiovascular Disease
Authors: Klein Samuel , Burke Lora E. , Bray George A. , Blair Steven , Allison David B. , Pi-Sunyer Xavier , Hong Yuling , Eckel Robert H.
Published: October 2004

Obesity adversely affects cardiac function, increases the risk factors for coronary heart disease, and is an independent risk factor for cardiovascular disease. The risk of developing coronary heart disease is directly related to the concomitant burden of obesity-related risk factors. Modest weight loss can improve diastolic function and affect the entire cluster of coronary heart disease risk factors simultaneously. This statement from the American Heart Association Council on Nutrition, Physical Activity, and Metabolism reviews the relationship between obesity and the cardiovascular system, evaluates the effect of weight loss on coronary heart disease risk factors and coronary heart disease, and provides practical weight management treatment guidelines for cardiovascular healthcare professionals. The data demonstrate that weight loss and physical activity can prevent and treat obesity-related coronary heart disease risk factors and should be considered a primary therapy for obese patients with cardiovascular disease.
Hormone Replacement Therapy and Stroke
Authors: Brass Lawrence M.
Published: October 2004

Bench research suggests that postmenopausal hormonal therapy is associated with beneficial effects on the brain and vascular system. Observational data suggest that postmenopausal hormone replacement therapy is associated with a 25% to 50% lower rate of cardiovascular disease; however, observational data for hormonal therapy is associated with the potential for significant biases. Clinical trial data are needed. There are 3 major clinical trials that inform us about stroke and postmenopausal hormone replacement therapy. Two trials focused on secondary prevention: the Heart and Estrogen/progesterone Replacement Study (HERS) and the Women’s Estrogen for Stroke Trial (WEST). One examined primary prevention: the Women’s Health Initiative (WHI). All indicate that postmenopausal hormone therapy is not effective for reducing the risk of a recurrent stroke or death among women with established vascular disease or for prevention of a first stroke. Similar results exist for cardiovascular disease. The results of these trials are now reflected in national guidelines. Hormone therapy should not be initiated to prevent vascular disease among postmenopausal women. As a result of these trials, the portion of postmenopausal women using hormone replacement therapy in the United States has fallen by more than half over the past decade.
Mechanisms of Hemorrhagic Transformation After Tissue Plasminogen Activator Reperfusion Therapy for Ischemic Stroke
Authors: Wang Xiaoying , Tsuji Kiyoshi , Lee Sun-Ryung , Ning MingMing , Furie Karen L. , Buchan Alastair M. , Lo Eng H.
Published: October 2004

Reperfusion therapy with tissue plasminogen activator (tPA) is a rational therapy for acute ischemic stroke. Properly titrated use of tPA improves clinical outcomes. However, there is also an associated risk of hemorrhagic transformation after tPA therapy. Emerging data now suggest that some of these potentially neurotoxic side effects of tPA may be due to its signaling actions in the neurovascular unit. Besides its intended role in clot lysis, tPA is also an extracellular protease and signaling molecule in brain. tPA mediates matrix remodeling during brain development and plasticity. By interacting with the NMDA-type glutamate receptor, tPA may amplify potentially excitotoxic calcium currents. At selected concentrations, tPA may be vasoactive. Finally, by augmenting matrix metalloproteinase (MMP) dysregulation after stroke, tPA may degrade extracellular matrix integrity and increase risks of neurovascular cell death, blood–brain barrier leakage, edema, and hemorrhage. Understanding these pleiotropic actions of tPA may reveal new therapeutic opportunities for combination stroke therapy.
Estrogens, Migraine, and Stroke
Authors: Bousser Marie-Germaine
Published: October 2004

Epidemiological studies suggest the existence of close but complex relationships between estrogens, migraine, and stroke in women before menopause. Migraine, particularly without aura, is strongly influenced by estrogens as illustrated by the frequency of onset at puberty, of menstrual migraine, and of improvement during pregnancy. Migraine, particularly with aura, is a risk factor for ischemic stroke with a relative risk of 3, further increased by tobacco smoking and oral contraceptive use. The pathophysiological mechanism underlying these close relationships remains unknown. In practice, given the very low absolute risk of stroke in young women, there is no systematic contraindication to oral contraceptive use in young female migraineurs but rather a firm recommendation for no smoking and for the use of low-estrogen-content pills or progestogens only, particularly in migraine with aura.
Amyloid Angiopathy–Related Vascular Cognitive Impairment
Authors: Greenberg Steven M. , Gurol M. Edip , Rosand Jonathan , Smith Eric E.
Published: October 2004

We review accumulating evidence that cerebrovascular amyloid deposition (cerebral amyloid angiopathy [CAA]) is an independent risk factor for cognitive dysfunction. The two population-based autopsy studies that have analyzed cognitive status during life as a function of CAA have each suggested deleterious effects of CAA on cognition even after controlling for age and Alzheimer disease pathology. We also review data from patients with CAA-related intracerebral hemorrhage (the one form of CAA that can be noninvasively recognized) suggesting associations of CAA with radiographic white matter abnormalities and cognitive impairment. These data highlight the importance of elucidating the effects of vascular amyloid on cerebrovascular function and of developing therapeutic strategies for this potentially widespread form of microvascular cognitive impairment.
Identifying Thresholds for Penumbra and Irreversible Tissue Damage
Authors: Heiss Wolf-Dieter , Sobesky Jan , Hesselmann Volker
Published: October 2004

Diffusion-weighted MRI (DWI) in combination with perfusion-weighted MRI (PWI) has become a widely accepted modality for the selection of patients amenable for acute therapy, if a mismatch between these procedures suggests viable penumbral tissue. However, DWI as well as PWI yields semiquantitative measures limiting the definitions of irreversible damage and of potentially viable penumbral tissue. These limitations of PWI/DWI may be better understood if findings in individual patients are compared with the results from measurements of blood flow, oxygen metabolism, and benzodiazepine receptor binding obtained with positron emission tomography (PET). Comparative studies with PET and MRI were performed in 3 groups of patients: (1) In 12 acute stroke patients, results from DWI (median, 6.5 hours after symptom onset) and
11
C-flumazenil (FMZ) PET (median, 85 minutes between DWI and PET) were compared with infarct extension 24 to 48 hours later on T2-weighted MRI. (2) In 11 acute stroke patients, results from PWI (median, 8 hours after symptom onset) were compared with cerebral blood flow measurements obtained with [
15
O]H
2
O PET (interval, 60 minutes between PWI and PET). (3) In 10 patients with acute (n=5) or chronic stroke (n=5), results from PWI/DWI were compared with PET of cerebral blood flow and oxygen consumption to detect mismatch or increased oxygen extraction fraction as surrogate markers of penumbra. Results were: (1) from regions with increased DWI intensity, decreased apparent diffusion coefficient (ADC) and decreased FMZ binding probability curves were computed for eventual infarction, and 95% prediction limits were determined. These limits predicted 83.5% (FMZ), 84.7% (DWI), and 70.9% (ADC) of the final infarct volume. However, the false-positive predictions were much higher for the DWI variables (5.1 and 3.6 cm
3
for DWI and ADC versus a median of 0 for FMZ). (2) The comparison of volumes generated by different time to peak (TTP) thresholds (PWI) and hypoperfusion <20 mL/100 g per minute (PET) indicates that a TTP delay of 4 to 6 seconds yields a fair estimate of hypoperfusion. (3) The PWI/DWI mismatch with TTP >4 seconds did not reliably correspond to the penumbra as assessed by PET (oxygen extraction fraction >150%). Only 6 of 10 patients with a mismatch had areas of penumbra. In these cases, the penumbra volume was overestimated by MRI. DWI correlates with FMZ results and, with a few exceptions, yields a good estimate of acute tissue damage and final infarct volume. PWI measures seem to be less reliable; the TTP prolongation of >4 seconds assessed only 83% of the volume of hypoperfusion <20 mL/100 g per minute. The mismatch volume imprecisely depicts increased oxygen extraction fraction, and, despite its clinical role for selection of patients for eventual therapy, it does not to seem to be a reliable correlate of penumbra.
The Genesis of Negative Concord: Syntax and Morphology of Negative Doubling
Authors: Watanabe Akira
Published: October 2004

I show that negative concord involves checking of the neg-features prompted by the uninterpretable focus feature of concord items, recasting Haegeman and Zanuttini's (1991, 1996) original account in the general theory of feature checking. A key theoretical mechanism is feature copying, which derives the core part of Neg-Factorization and is also shown to provide the foundation for the notion of chains defined in terms of occurrences. The proposed analysis of negative concord supports Merchant's (2001) theory of ellipsis, according to which ellipsis is PF deletion and requires semantic identity. I also discuss in detail how morphology interacts with properties of negative concord, taking into account wide-ranging crosslinguistic patterns.
Which Wič Is Which? Prefixing and Suffixing in Klamath Full-Root Reduplication
Authors: Marlo Michael R. , Pharris Nicholas J.
Published: October 2004

This article presents a new analysis of full-root reduplication in Klamath. This process, hitherto termed “intensive” reduplication, has previously been analyzed as involving prefixation. Klamath prefixes normally induce vowel reduction in the following morpheme, but the intensive reduplicant does not. McCarthy and Prince (1995) attempt to account for this divergent behavior by invoking base-reduplicant faithfulness; Zoll (2002) attributes it to a stem-internal/stem-external distinction among prefixes. Based on phonological and semantic criteria, our analysis resolves intensive reduplication into several classes, including both prefixing and suffixing types. This analysis improves empirical coverage over previous accounts while minimizing assumptions and demonstrates that careful morphological and phonological analysis can distinguish between prefixing and suffixing copying in cases of seemingly ambiguous total reduplication.
Topicalization, Focalization, Lexical Insertion, and Scrambling
Authors: Bošković Željko
Published: October 2004

In this reply, I show that Russian examples that Bailyn (2001) uses to argue against Bošković and Takahashi's (1998) analysis of scrambling are irrelevant to the analysis because they in fact do not involve scrambling. I also establish a crosslinguistic correlation between lack of articles and availability of scrambling and provide an account of the correlation under Bošković and Takahashi's approach to scrambling.
Immunizing against the American Other: Racism, Nationalism, and Gender in U.S.-Icelandic Military Relations during the Cold War
Authors: Ingimundarson Valur
Published: October 2004

The 1951 U.S. -Icelandic Defense Agreement paved the way for a permanent U.S. military presence at the Keflavik base in Iceland, an outpost that played a crucial role in U.S. strategy during the Cold War. The article explores two gender-related aspects of the U.S. -Icelandic Cold War relationship:the restrictions on off-base movements of U.S. soldiers, and the secret ban imposed by the Icelandic government on the stationing of black U.S. troops in Iceland. These practices were meant to “protect” Icelandic women and to preserve a homogeneous “national body.” Although U.S. officials repeatedly tried to have the restrictions lifted, the Icelandic government refused to modify them until the racial ban was publicly disclosed in late 1959. Even after the practice came to light, it took another several years before the ban was gradually eliminated. Misguided though the Icelandic restrictions may have been, they did, paradoxically, help to defuse domestic opposition to Iceland's pro-American foreign policy course and thus preserved the country's role in the Western alliance.
German and Soviet Military Doctrinal Innovation before World War II
Authors: Roberts Cynthia
Published: October 2004

In the lead-up to World War II, both Germany and the Soviet Union pursued important changes in military doctrine that proved crucial during the armed confrontation between the two countries in 1941–1945. Using a new book by the military historian Mary Habeck as a point of departure, this essay explains how the German and Soviet armed forces by the late 1930s had developed almost identical doctrines without extensively borrowing from each other. Although the doctrinal innovations that informed the German Blitzkrieg and the Soviet conception of “deep battle” have long attracted attention, Habeck's book is the first detailed comparison of the development of armored warfare in these two countries. Although the book does not provide a comprehensive explanation of the sources of innovation in military doctrine, it sheds a great deal of light on the revolutionary changes in German and Soviet military doctrines during the interwar years.
Bilād al-Šām in the Modern Period: Integration into the Ottoman Empire and New Relations with Europe
Authors: Philipp Thomas
Published: October 2004

Historical periods are the attempt of the historian to shape the endless flow of events in time into meaningful, coherent entities. Periods are often bracketed by "decisive" events and comprise one or more dominant features which give "unity" to the period so chosen. The periodization of history must by necessity remain a work in progress. It is always an attempt of interpretation and giving meaning and, hence, always open to revision. Ottoman rule over the Arab provinces was always considered as such a period, defined by the conquest and the disintegration of the Ottoman Empire. The present article tries to probe in how far these events are indeed meaningful for the periodization of the history of Bilad al-Sham, the geographical Syria.
Academic Salaries in the UK and US
Authors: Stevens Philip Andrew
Published: October 2004

We examine the wages of graduates inside and outside of academe in both the UK and US. We find that in both the UK and the US an average graduate working in the HE sector would earn less over his or her lifetime than graduates working in non-academic sectors. The largest disparity occurs throughout the earlier and middle career period and so if people discount their future earnings, the difference will be even greater than these figures suggest. Academics in the UK earn less than academics in the US at all ages. This difference cannot be explained by differences in observable characteristics such as age, gender or ethnicity. This leads us to conclude that the differences in UK and US academic wages are unlikely to be due to differences in the academics themselves, but rather to differences in labour markets generally and in systems of higher education between the two countries, which suggests that there is a strong pay incentive for academics to migrate from the UK to the US.
Accurate crystal chemistry of ferric smectites from the lateritic nickel ore of Murrin Murrin (Western Australia). I. XRD and multi-scale chemical approaches
Authors: Gaudin A. , Grauby O. , Noack Y. , Decarreau A. , Petit S.
Published: October 2004

Lateritic weathering profiles developed on serpentinized peridotites of Murrin Murrin (Western Australia) exhibit thick smectite zones (10–15 m). The smectites from plasma and fissures were characterized by XRD, chemical analyses (ICP-AES, SEM-EDX and TEM-EDX) and Mo¨ssbauer spectroscopy. These Fe-rich smectites, previously described as nontronites, are in fact more complex. Their layer charges originate from both the tetrahedral and octahedral sheets. Plasma and notably fissure smectites exhibit, from the bulk sample scale to the particle scale, large and continuous Al for (Fe+Cr) substitutions, covering a chemical gap previously described for dioctahedral smectites ranging between nontronite and beidellite end-members. Lastly, they exhibit an octahedral occupancy slightly above 2, due to a low (Mg+Ni) trioctahedral contribution. Thus, the smectites occurring in weathering profiles of ultrabasic rocks can have actual chemistries intermediate between four dioctahedral end-members (beidellite, nontronite, montmorillonite and previously rarely described ferric-montmorillonite) and a trioctahedral one ((Mg+Ni)-saponite).
Iron (III)-doped montmorillonite catalysis of alkenes bearing sulphoxide groups in Diels-Alder reactions
Authors: Gültekіn Z.
Published: October 2004

Fe3+-doped K10 montmorillonite combined with 2,6-di-tert-butyl-4-methyl-phenol is a potent catalytic system for trans-2-methylene-1,3-dithiolane 1,3-dioxide as a dienophile. Cycloaddition occurs with cyclopentadiene and furan as a diene at room temperature in short time and with good yields (64% overall).
A computational approach for ordering signal transduction pathway components from genomics and proteomics Data
Authors: Liu Yin , Zhao Hongyu
Published: October 2004

Background

Signal transduction is one of the most important biological processes by which cells convert an external signal into a response. Novel computational approaches to mapping proteins onto signaling pathways are needed to fully take advantage of the rapid accumulation of genomic and proteomics information. However, despite their importance, research on signaling pathways reconstruction utilizing large-scale genomics and proteomics information has been limited.

Results

We have developed an approach for predicting the order of signaling pathway components, assuming all the components on the pathways are known. Our method is built on a score function that integrates protein-protein interaction data and microarray gene expression data. Compared to the individual datasets, either protein interactions or gene transcript abundance measurements, the integrated approach leads to better identification of the order of the pathway components.

Conclusions

As demonstrated in our study on the yeast MAPK signaling pathways, the integration analysis of high-throughput genomics and proteomics data can be a powerful means to infer the order of pathway components, enabling the transformation from molecular data into knowledge of cellular mechanisms.
The structurally constrained protein evolution model accounts for sequence patterns of the LβH superfamily
Authors: Parisi Gustavo , Echave Julián
Published: October 2004

Background

Structure conservation constrains evolutionary sequence divergence, resulting in observable sequence patterns. Most current models of protein evolution do not take structure into account explicitly, being unsuitable for investigating the effects of structure conservation on sequence divergence. To this end, we recently developed the Structurally Constrained Protein Evolution (SCPE) model. The model starts with the coding sequence of a protein with known three-dimensional structure. At each evolutionary time-step of an SCPE simulation, a trial sequence is generated by introducing a random point mutation in the current coding DNA sequence. Then, a "score" for the trial sequence is calculated and the mutation is accepted only if its score is under a given cutoff, λ. The SCPE score measures the distance between the trial sequence and a given reference sequence, given the structure. In our first brief report we used a "global score", in which the same reference sequence, the ancestral one, was used at each evolutionary step. Here, we introduce a new scoring function, the "local score", in which the sequence accepted at the previous evolutionary time-step is used as the reference. We assess the model on the UDP-N-acetylglucosamine acyltransferase (LPXA) family, as in our previous report, and we extend this study to all other members of the left-handed parallel beta helix fold (LβH) superfamily whose structure has been determined.

Results

We studied site-dependent entropies, amino acid probability distributions, and substitution matrices predicted by SCPE and compared with experimental data for several members of the LβH superfamily. We also evaluated structure conservation during simulations. Overall, SCPE outperforms JTT in the description of sequence patterns observed in structurally constrained sites. Maximum Likelihood calculations show that the local-score and global-score SCPE substitution matrices obtained for LPXA outperform the JTT model for the LPXA family and for the structurally constrained sites of class i of other members within the LβH superfamily.

Conclusion

We extended the SCPE model by introducing a new scoring function, the local score. We performed a thorough assessment of the SCPE model on the LPXA family and extended it to all other members of known structure of the LβH superfamily.
Microarray and comparative genomics-based identification of genes and gene regulatory regions of the mouse immune system
Authors: Hutton John J , Jegga Anil G , Kong Sue , Gupta Ashima , Ebert Catherine , Williams Sarah , Katz Jonathan D , Aronow Bruce J
Published: October 2004

Background

In this study we have built and mined a gene expression database composed of 65 diverse mouse tissues for genes preferentially expressed in immune tissues and cell types. Using expression pattern criteria, we identified 360 genes with preferential expression in thymus, spleen, peripheral blood mononuclear cells, lymph nodes (unstimulated or stimulated), or in vitro activated T-cells.

Results

Gene clusters, formed based on similarity of expression-pattern across either all tissues or the immune tissues only, had highly significant associations both with immunological processes such as chemokine-mediated response, antigen processing, receptor-related signal transduction, and transcriptional regulation, and also with more general processes such as replication and cell cycle control. Within-cluster gene correlations implicated known associations of known genes, as well as immune process-related roles for poorly described genes. To characterize regulatory mechanisms and cis-elements of genes with similar patterns of expression, we used a new version of a comparative genomics-based cis-element analysis tool to identify clusters of cis-elements with compositional similarity among multiple genes. Several clusters contained genes that shared 5–6 cis-elements that included ETS and zinc-finger binding sites. cis-Elements AP2 EGRF ETSF MAZF SP1F ZF5F and AREB ETSF MZF1 PAX5 STAT were shared in a thymus-expressed set; AP4R E2FF EBOX ETSF MAZF SP1F ZF5F and CREB E2FF MAZF PCAT SP1F STAT cis-clusters occurred in activated T-cells; CEBP CREB NFKB SORY and GATA NKXH OCT1 RBIT occurred in stimulated lymph nodes.

Conclusion

This study demonstrates a series of analytic approaches that have allowed the implication of genes and regulatory elements that participate in the differentiation, maintenance, and function of the immune system. Polymorphism or mutation of these could adversely impact immune system functions.
Family doctors' involvement with families in Estonia
Authors: Oona Marje , Kalda Ruth , Lember Margus , Maaroos Heidi-Ingrid
Published: October 2004

Background

Family doctors should care for individuals in the context of their family. Family has a powerful influence on health and illness and family interventions have been shown to improve health outcomes for a variety of health problems. The aim of the study was to investigate the Estonian family doctors' (FD) attitudes to the patients' family-related issues in their work: to explore the degree of FDs involvement in family matters, their preparedness for management of family-related issues and their self-assessment of the ability to manage different family-related problems.

Methods

A random sample (n = 236) of all FDs in Estonia was investigated using a postal questionnaire. Altogether 151 FDs responded to the questionnaire (response rate 64%), while five of them were excluded as they did not actually work as FDs.

Results

Of the respondents, 90% thought that in managing the health problems of patients FDs should communicate and cooperate with family members. Although most of the family doctors agreed that modifying of the health damaging risk factors (smoking, alcohol and drug abuse) of their patients and families is their task, one third of them felt that dealing with these problems is ineffective, or perceived themselves as poorly prepared or having too little time for such activities. Of the respondents, 58% (n = 83) were of the opinion that they could modify also relationship problems.

Conclusions

Estonian family doctors are favourably disposed to involvement in family-related problems, however, they need some additional training, especially in the field of relationship management.
Psychological trauma and evidence for enhanced vulnerability for posttraumatic stress disorder through previous trauma among West Nile refugees
Authors: Neuner Frank , Schauer Maggie , Karunakara Unni , Klaschik Christine , Robert Christina , Elbert Thomas
Published: October 2004

Background

Political instability and the civil war in Southern Sudan have resulted in numerous atrocities, mass violence, and forced migration for vast parts of the civilian population in the West Nile region. High exposure to traumatic experiences has been particularly prominent in the Ugandan and Sudanese of the West Nile Region, representing an indication of the psychological strain posed by years of armed conflict.

Methods

In this study the impact of traumatic events on the prevalence and severity of posttraumatic stress disorder (PTSD) in a random sample of 3.339 Ugandan nationals, Sudanese nationals, and Sudanese refugees (1.831 households) of the West Nile region is assessed.

Results

Results show a positive correlation between the number of traumatic events and the number of endorsed PTSD symptoms. Of the 58 respondents who experienced the greatest number of traumatizing experiences, all reported symptoms which met the DSM-IV criteria for PTSD.

Conclusions

There is a clear dose-effect relationship between traumatic exposure and PTSD in the studied populations with high levels of traumatic events. In this context, it is probable that any individual could develop PTSD regardless of other risk-factors once the trauma load reaches a certain threshold.
Pregnancy weight gain and breast cancer risk
Authors: Kinnunen Tarja I , Luoto Riitta , Gissler Mika , Hemminki Elina , Hilakivi-Clarke Leena
Published: October 2004

Background

Elevated pregnancy estrogen levels are associated with increased risk of developing breast cancer in mothers. We studied whether pregnancy weight gain that has been linked to high circulating estrogen levels, affects a mother's breast cancer risk.

Methods

Our cohort consisted of women who were pregnant between 1954–1963 in Helsinki, Finland, 2,089 of which were eligible for the study. Pregnancy data were collected from patient records of maternity centers. 123 subsequent breast cancer cases were identified through a record linkage to the Finnish Cancer Registry, and the mean age at diagnosis was 56 years (range 35 – 74). A sample of 979 women (123 cases, 856 controls) from the cohort was linked to the Hospital Inpatient Registry to obtain information on the women's stay in hospitals.

Results

Mothers in the upper tertile of pregnancy weight gain (>15 kg) had a 1.62-fold (95% CI 1.03–2.53) higher breast cancer risk than mothers who gained the recommended amount (the middle tertile, mean: 12.9 kg, range 11–15 kg), after adjusting for mother's age at menarche, age at first birth, age at index pregnancy, parity at the index birth, and body mass index (BMI) before the index pregnancy. In a separate nested case-control study (n = 65 cases and 431 controls), adjustment for BMI at the time of breast cancer diagnosis did not modify the findings.

Conclusions

Our study suggests that high pregnancy weight gain increases later breast cancer risk, independently from body weight at the time of diagnosis.
Assessment of the dynamics of atrial signals and local atrial period series during atrial fibrillation: effects of isoproterenol administration
Authors: Mainardi Luca T , Corino Valentina DA , Lombardi Leonida , Tondo Claudio , Mantica Massimo , Lombardi Federico , Cerutti Sergio
Published: October 2004

Background

The autonomic nervous system (ANS) plays an important role in the genesis and maintenance of atrial fibrillation (AF), but quantification of its electrophysiologic effects is extremely complex and difficult. Aim of the study was to evaluate the capability of linear and non-linear indexes to capture the fine changing dynamics of atrial signals and local atrial period (LAP) series during adrenergic activation induced by isoproterenol (a sympathomimetic drug) infusion.

Methods

Nine patients with paroxysmal or persistent AF (aged 60 ± 6) underwent electrophysiological study in which isoproterenol was administered to patients. Atrial electrograms were acquired during i) sinus rhythm (SR); ii) sinus rhythm during isoproterenol (SRISO) administration; iii) atrial fibrillation (AF) and iv) atrial fibrillation during isoproterenol (AFISO) administration. The level of organization between two electrograms was assessed by the synchronization index (S), whereas the degree of recurrence of a pattern in a signal was defined by the regularity index (R). In addition, the level of predictability (LP) and regularity of LAP series were computed.

Results

LAP series analysis shows a reduction of both LP and R index during isoproterenol infusion in SR and AF (RSR = 0.75 ± 0.07 RSRISO = 0.69 ± 0.10, p < 0.0001; RAF = 0.31 ± 0.08 RAFISO = 0.26 ± 0.09, p < 0.0001; LPSR = 99.99 ± 0.001 LPSRISO = 99.97 ± 0.03, p < 0.0001; LPAF = 69.46 ± 21.55 LPAFISO = 55 ± 24.75; p < 0.0001). Electrograms analysis shows R index reductions both in SR (RSR = 0.49 ± 0.08 RSRISO = 0.46 ± 0.09 p < 0.0001) and in AF (RAF = 0.29 ± 0.09 RAFISO = 0.28 ± 0.08 n.s.).

Conclusions

The proposed parameters succeeded in discriminating the subtle changes due to isoproterenol infusion during both the rhythms especially when considering LAP series analysis. The reduced value of analyzed parameters after isoproterenol administration could reflect an important pro-arrhythmic influence of adrenergic activation on favoring maintenance of AF.
Killing Bugs at the Bedside: A prospective hospital survey of how frequently personal digital assistants provide expert recommendations in the treatment of infectious diseases
Authors: Burdette Steven D , Herchline Thomas E , Richardson W Scott
Published: October 2004

Background

Personal Digital Assistants (PDAS) are rapidly becoming popular tools in the assistance of managing hospitalized patients, but little is known about how often expert recommendations are available for the treatment of infectious diseases in hospitalized patients.

Objective

To determine how often PDAs could provide expert recommendations for the management of infectious diseases in patients admitted to a general medicine teaching service.

Design

Prospective observational cohort study

Setting

Internal medicine resident teaching service at an urban hospital in Dayton, Ohio

Patients

212 patients (out of 883 patients screened) were identified with possible infectious etiologies as the cause for admission to the hospital.

Measurements

Patients were screened prospectively from July 2002 until October 2002 for infectious conditions as the cause of their admissions. 5 PDA programs were assessed in October 2002 to see if treatment recommendations were available for managing these patients. The programs were then reassessed in January 2004 to evaluate how the latest editions of the software would perform under the same context as the previous year.

Results

PDAs provided treatment recommendations in at least one of the programs for 100% of the patients admitted over the 4 month period in the 2004 evaluation. Each of the programs reviewed improved from 2002 to 2004, with five of the six programs offering treatment recommendations for over 90% of patients in the study.

Conclusion

Current PDA software provides expert recommendations for a great majority of general internal medicine patients presenting to the hospital with infectious conditions.
Predicting gender differences as latent variables: summed scores, and individual item responses: a methods case study
Authors: Pietrobon Ricardo , Taylor Marcus , Guller Ulrich , Higgins Laurence D , Jacobs Danny O , Carey Timothy
Published: October 2004

Background

Modeling latent variables such as physical disability is challenging since its measurement is performed through proxies. This poses significant methodological challenges. The objective of this article is to present three different methods to predict latent variables based on classical summed scores, individual item responses, and latent variable models.

Methods

This is a review of the literature and data analysis using "layers of information". Data was collected from the North Carolina Back Pain Project, using a modified version of the Roland Questionnaire.

Results

The three models are compared in relation to their goals and underlying concepts, previous clinical applications, data requirements, statistical theory, and practical applications. Initial linear regression models demonstrated a difference in disability between genders of 1.32 points (95% CI 0.65, 2.00) on a scale from 0–23. Subsequent item analysis found contradictory results across items, with no clear pattern. Finally, IRT models demonstrated three items were demonstrated to present differential item functioning. After these items were removed, the difference between genders was reduced to 0.78 points (95% CI, -0.99, 1.23). These results were shown to be robust with re-sampling methods.

Conclusions

Purported differences in the levels of a latent variable should be tested using different models to verify whether these differences are real or simply distorted by model assumptions.
Clinical and inheritance profiles of Kallmann syndrome in Jordan
Authors: AbuJbara Mousa A , Hamamy Hanan A , Jarrah Nadim S , Shegem Nadima S , Ajlouni Kamel M
Published: October 2004

Background

Proper management of patients with Kallmann syndrome (KS) allows them to attain a normal reproductive health. The purpose of this study is to demonstrate the presentation modalities, phenotypes and the modes of inheritance among 32 patients with Kallmann syndrome in Jordan. Recognition of the syndrome allows for prompt proper management and provision of genetic counselling.

Subjects

Over a period of five years (1999–2004), the clinical and inheritance profiles of 26 male and 6 female patients with Kallmann syndrome from 12 families were evaluated at the National Center for Diabetes, Endocrinology and Genetics in Jordan.

Results

The patients belonged to twelve Jordanian and Palestinian families and their age at presentation ranged from 4 – 46 years. Nine boys aged 4–14 years presented with cryptorchidism and microphallus, all other males presented with delayed puberty, hypogonadism and/or infertility. The main presentation among six female patients was primary amenorrhea. Intrafamilial variability in clinical phenotype was specifically evident for renal abnormalities and sensorineural hearing impairment. Familial KS was diagnosed in 27 patients belonging to five families with the X-linked mode of inheritance and two families with the autosomal recessive mode of inheritance.

Conclusions

(1) the majority of cases in this study represented the X-linked form of KS, which might point to a high prevalence of Kal 1 gene in the population. (2) Genetic counselling helps these families to reach a diagnosis at an early age and to decide about their reproductive options. (3) Children presenting with cryptorchidism and microphallus in our population should be investigated for KS.
Secondary neurons are arrested in an immature state by formation of epithelial vesicles during neurogenesis of the spider Cupiennius salei
Authors: Stollewerk Angelika
Published: October 2004

Background

In the spider Cupiennius salei about 30 groups of neural precursors are generated per hemi-segment during early neurogenesis. Analysis of the ventral neuromeres after invagination of the primary neural precursor groups revealed that secondary neural precursors arise during late embryogenesis that partially do not differentiate until larval stages.

Results

In contrast to the primary groups, the secondary invaginating cells do not detach from each other after invagination but maintain their epithelial character and form so-called epithelial vesicles. As revealed by dye labeling, secondary neural precursors within epithelial vesicles do not show any morphological features of differentiation indicating that the formation of epithelial vesicles after invagination leads to a delay in the differentiation of the corresponding neural precursors. About half of the secondary neural precursor groups do not dissociate from each other during embryogenesis indicating that they provide neural precursors for larval and adult stages.

Conclusions

Secondary neural precursors are arrested in an immature state by formation of epithelial vesicles. This mechanism facilitates the production of larval neural precursors during embryogenesis. I discuss the evolutionary changes that have occured during neural precursor formation in the arthropod group and present a model for the basal mode of neurogenesis.
Influence of passive leg movements on blood circulation on the tilt table in healthy adults
Authors: Czell David , Schreier Reinhard , Rupp Rüdiger , Eberhard Stephen , Colombo Gery , Dietz Volker
Published: October 2004

Background

One problem in the mobilization of patients with neurological diseases, such as spinal cord injury, is the circulatory collapse that occurs while changing from supine to vertical position because of the missing venous pump due to paralyzed leg muscles. Therefore, a tilt table with integrated stepping device (tilt stepper) was developed, which allows passive stepping movements for performing locomotion training in an early state of rehabilitation. The aim of this pilot study was to investigate if passive stepping and cycling movements of the legs during tilt table training could stabilize blood circulation and prevent neurally-mediated syncope in healthy young adults.

Methods

In the first experiment, healthy subjects were tested on a traditional tilt table. Subjects who had a syncope or near-syncope in this condition underwent a second trial on the tilt stepper. In the second experiment, a group of healthy subjects was investigated on a traditional tilt table, the second group on the tilt ergometer, a device that allows cycling movements during tilt table training. We used the chi-square test to compare the occurrence of near-syncope/syncope in both groups (tilt table/tilt stepper and tilt table/tilt ergometer) and ANOVA to compare the blood pressure and heart rate between the groups at the four time intervals (supine, at 2 minutes, at 6 minutes and end of head-up tilt).

Results

Separate chi-square tests performed for each experiment showed significant differences in the occurrence of near syncope or syncope based on the device used. Comparison of the two groups (tilt stepper/ tilt table) in experiment one (ANOVA) showed that blood pressure was significantly higher at the end of head-up tilt on the tilt stepper and on the tilt table there was a greater increase in heart rate (2 minutes after head-up tilt). Comparison of the two groups (tilt ergometer/tilt table) in experiment 2 (ANOVA) showed that blood pressure was significantly higher on the tilt ergometer at the end of head-up tilt and on the tilt table the increase in heart rate was significantly larger (at 6 min and end of head-up tilt).

Conclusions

Stabilization of blood circulation and prevention of benign syncope can be achieved by passive leg movement during a tilt table test in healthy adults.
Case report: Greater meningeal inflammation in lumbar than in ventricular region in human bacterial meningitis
Authors: Naija Walid , Matéo Joaquim , Raskine Laurent , Timsit Jean-François , Lukascewicz Anne-Claire , George Bernard , Payen Didier , Mebazaa Alexandre
Published: October 2004

Differences in the composition of ventricular and lumbar cerebrospinal fluid (CSF) based on single pairs of samples have previously been described. We describe a patient that developed post-surgical recurrent meningitis monitored by daily biochemical and bacteriological CSF analysis, simultaneously withdrawn from lumbar space and ventricles. A 20-year-old Caucasian man was admitted to the ICU after a resection of a chordoma that extended from the sphenoidal sinus to the anterior face of C2. CSF was continuously leaking into the pharyngeal cavity after surgery, and three episodes of recurrent meningitis, all due to Pseudomonas aeruginosa O12, occurred. Our case showed permanent ventricular-to-lumbar CSF gradients of leukocytes, protein and glucose that were increased during the acute phase of meningitis, with the greatest amplitude being observed when bacteria were present in both ventricular and lumbar CSF. This might suggest a greater extent of meningeal inflammation in the lumbar than in the ventricular region. Our case also showed that the increase in intravenous antibiotics (cefepim from 8 to 12 g/day and ciprofloxacine from 1.2 to 2.4 g/day) led to an increase in concentration in plasma but not in CSF.
Cardiovascular stability during arteriovenous extracorporeal therapy: a randomized controlled study in lambs with acute lung injury
Authors: Totapally Balagangadhar R , Sussmane Jeffrey B , Torbati Dan , Gelvez Javier , Fakioglu Harun , Mao Yongming , Olarte Jose L , Wolfsdorf Jack
Published: October 2004

Introduction

Clinical application of arteriovenous (AV) extracorporeal membrane oxygenation (ECMO) requires assessment of cardiovascular ability to respond adequately to the presence of an AV shunt in the face of acute lung injury (ALI). This ability may be age dependent and vary with the experimental model. We studied cardiovascular stability in a lamb model of severe ALI, comparing conventional mechanical ventilation (CMV) with AV-ECMO therapy.

Methods

Seventeen lambs were anesthetized, tracheotomized, paralyzed, and ventilated to maintain normocapnia. Femoral and jugular veins, and femoral and carotid arteries were instrumented for the AV-ECMO circuit, systemic and pulmonary artery blood pressure monitoring, gas exchange, and cardiac output determination (thermodilution technique). A severe ALI (arterial oxygen tension/inspired fractional oxygen <200) was induced by lung lavage (repeated three times, each with 5 ml/kg saline) followed by tracheal instillation of 2.5 ml/kg of 0.1 N HCl. Lambs were consecutively assigned to CMV treatment (n = 8) or CMV plus AV-ECMO therapy using up to 15% of the cardiac output for the AV shunt flow during a 6-hour study period (n = 9). The outcome measures were the degree of inotropic and ventilator support needed to maintain hemodynamic stability and normocapnia, respectively.

Results

Five of the nine lambs subjected to AV-ECMO therapy (56%) died before completion of the 6-hour study period, as compared with two out of eight lambs (25%) in the CMV group (P > 0.05; Fisher's exact test). Surviving and nonsurviving lambs in the AV-ECMO group, unlike the CMV group, required continuous volume expansion and inotropic support (P < 0.001; Fisher's exact test). Lambs in the AV-ECMO group were able to maintain normocapnia with a maximum of 30% reduction in the minute ventilation, as compared with the CMV group (P < 0.05).

Conclusion

AV-ECMO therapy in lambs subjected to severe ALI requires continuous hemodynamic support to maintain cardiovascular stability and normocapnia, as compared with lambs receiving CMV support.
Transcriptome analysis of haploid male gametophyte development in Arabidopsis
Authors: Honys David , Twell David
Published: October 2004

Background

The haploid male gametophyte generation of flowering plants consists of two- or three-celled pollen grains. This functional specialization is thought to be a key factor in the evolutionary success of flowering plants. Moreover, pollen ontogeny is also an attractive model in which to dissect cellular networks that control cell growth, asymmetric cell division and cellular differentiation. Our objective, and an essential step towards the detailed understanding of these processes, was to comprehensively define the male haploid transcriptome throughout development.

Results

We have developed staged spore isolation procedures for Arabidopsis and used Affymetrix ATH1 genome arrays to identify a total of 13,977 male gametophyte-expressed mRNAs, 9.7% of which were male-gametophyte-specific. The transition from bicellular to tricellular pollen was accompanied by a decline in the number of diverse mRNA species and an increase in the proportion of male gametophyte-specific transcripts. Expression profiles of regulatory proteins and distinct clusters of coexpressed genes were identified that could correspond to components of gametophytic regulatory networks. Moreover, integration of transcriptome and experimental data revealed the early synthesis of translation factors and their requirement to support pollen tube growth.

Conclusions

The progression from proliferating microspores to terminally differentiated pollen is characterized by large-scale repression of early program genes and the activation of a unique late gene-expression program in maturing pollen. These data provide a quantum increase in knowledge concerning gametophytic transcription and lay the foundations for new genomic-led studies of the regulatory networks and cellular functions that operate to specify male gametophyte development.
Using the Canadian Code Of Ethics for Registered Nurses to Explore Ethics in Palliative Care Research
Authors: Arraf Kelly , Cox Ginny , Oberle Kathleen
Published: October 2004

Nursing research in palliative care raises specific and challenging ethical issues. Questions have arisen about whether such research is morally justified, given the low likelihood of direct benefit to dying patients as research participants. The Canadian Code of ethics for registered nurses outlines eight primary values intended to guide nursing practice. We use these values to explore the moral dimensions of research with the palliative care population. Our conclusion is that palliative care research is needed to foster excellent care for these patients and their families, but that nurses must remain constantly vigilant to ensure that participants are protected from resultant harms. Through this exploration we highlight particular considerations that nurse researchers must contemplate when accessing a vulnerable population.