bluuebunny/crossref_metadata_2025 huggingface dataset:
The main end points in human hypertension.
Authors: Wilhelmsen L
Published: August 2012

Prospective data from Western populations show a fairly steady increase in the incidence of total mortality as well as of myocardial infarction (MI) and sudden coronary death (SD) with increasing blood pressure levels. In the age groups up to 70 years, stroke is much less common than MI and SD at virtually all blood pressure levels, but for older men and also for somewhat younger women, stroke is as common as MI and SD at the highest blood pressure levels. The incidence of MI and SD is strongly dependent on serum lipid abnormalities and smoking habits, whereas stroke appears to depend very little on lipid levels and in only a few studies appears related to smoking habits. Thus, the effect of blood pressure is appreciably modified by the presence of some other abnormalities that are believed to enhance coronary arteriosclerosis. There are major differences between populations with respect to the incidence of MI, SD, and stroke. MI mortality and SD have, for example, been very high in the United States, whereas stroke mortality has been low. In Japan, on the other hand, stroke mortality has been high and MI mortality and SD have been low. Sweden has occupied an intermediate position with respect to MI mortality and SD, which have been increasing slightly while they have been decreasing in the United States, whereas stroke mortality in Sweden and in the other Scandinavian countries has been very low and is even showing a slight decrease. Both prospective epidemiologic studies and intervention trials indicate some influence of blood pressure on noncardiovascular mortality, such as that from cancer.
Early versus late onset of therapy. Experiences from animal studies.
Authors: Folkow B
Published: August 2012

Established primary hypertension is characterized by an "upward structural resetting," that encompasses all pressure-exposed cardiovascular sections. This also affects several of the dominating barostat mechanisms, such as those based on the cardiovascular baroreceptors and volume receptors and on the renal excretory function. One major long-term goal in antihypertensive treatment, therefore, is to achieve reversal and, if possible, normalization of this structural resetting, the more so because such reversal would also interrupt the positive feedback interaction with functional excitatory mechanisms. It is, however, very difficult to analyze precisely the rate and extent of structural cardiovascular reversal in humans, and also whether some antihypertensive drugs are in these respects more efficient than others. In this respect, model therapy studies in rat primary hypertension offer several advantages, thanks to the greatly compressed time scale, uniform material, and easily controlled conditions. This facilitates the elucidation of such important problems as the relative merits of early versus late treatment and optimal duration and intensity of treatment, as well as which drug actions are most efficient in normalizing cardiovascular design. The relatively few rat model studies of structural cardiovascular reversal so far performed are outlined briefly. It is concluded that extended studies along these lines would be of great value in clarifying some general principles of antihypertensive treatment that are also likely to be relevant to primary hypertension in humans.
Trophic effects of peripheral adrenergic nerves on vascular structure.
Authors: Bevan R D
Published: August 2012

In the rat and rabbit, evidence for a trophic action of sympathetic nerves on vascular pattern and structure has been reviewed. Effects have been identified by denervation and reinnervation techniques in blood vessels of different size from different regions. Following denervation, increased nonspecific sensitivity to constrictor agents occurs at all ages. In contrast, sympathetic trophic effects on muscle mass, extracellular artery components, and vessel number in the microvasculature were observed predominantly during growth. The mechanism of this action is not known, but the central ear artery in the rabbit was associated with nerve impulses.
Functional dynamics of the left ventricle in hypertensive hypertrophy and failure.
Authors: Strauer B E
Published: August 2012

In essential hypertension ventricular function is determined primarily by the degree of hypertrophy (myocardial factor) and by the organic complications in the coronary artery (coronary factor). Ventricular function is inversely correlated with ventricular size and systolic wall stress, inasmuch as ventricular function diminishes when these two variables increase. Even the young hypertensive heart of normal size with no angiographic abnormalities appears to be prone to ischemia, because the coronary reserve is seriously limited even in the absence of coronary stenosis. Unlike ventricular distensibility, myocardial compliance may be normal even in the presence of pronounced myocardial hypertrophy. As myocardial compliance decreases, systolic wall stress increases and ventricular function is reduced. The hypertensive heart, the most common form of an irregular hypertrophy of the ventricular wall, is found in 14% of such cases. Analysis of the degree of hypertrophy shows that the hypertrophy can be inappropriately high (high mass-to-volume ratio, reduced wall stress), appropriate, or inappropriately low (normal mass-to-volume ratio, increased wall stress). Digitalis glycosides, together with antihypertensive measures, are indicated for the dilated hypertensive heart; beta-receptor blockers are sound medication for the compensated hypertensive heart both with and without coronary stenoses. The following discussion includes classification of hypertensive heart disease based on the cardiac complications following hypertension.
Synthesis of collagen in cardiac and vascular walls.
Authors: Gilligan J P , Spector S
Published: August 2012

Collagen synthesis and content have been shown to be elevated in the arterial wall and heart of hypertensive animals. These increases in collagen synthesis and content have been implicated in the maintenance of raised blood pressure. Inhibitors of collagen synthesis, beta APN and 3,4-dihydroproline, were shown to delay the onset of hypertension and reverse established hypertension. Therapeutic intervention with antihypertensive drugs resulted in a decrease in arterial collagen synthesis and a reversal of cardiac hypertrophy. In some instances (i.e., DOCA-salt), chronic administration of antihypertensive drugs caused a restructuring of the arterial wall and resulted in an apparent remission of the hypertensive disease.
The inhomogeneity and appropriateness of the myocardial response to stress.
Authors: Alpert N R , Mulieri L A
Published: August 2012

Myocardial hypertrophy, with high morbidity and mortality, is a natural outcome of hypertensive heart disease. The increase in myocardial mass is associated with a cellular and subcellular reorganization of the myocytes. The following study uses rapid myothermal techniques to assess the contribution of the major intracellular changes to the adaptive hypertrophic process in various heart models. Pressure overload and thyrotoxic hypertrophy were produced in the rabbit. In the rat, hypertrophy was produced by constricting the renal artery (Goldblatt hypertensive rat) or by using the spontaneously hypertensive rat strain. Atrophy was produced by administration of propylthiouracil in the drinking water. The V1/V3 myosin isoenzyme ratio was decreased in the pressure overload, Goldblatt, and propylthiouracil animals. This was associated with a decrease in total activity-related heat, initial heat, and tension-dependent heat per tension time integral. The tension-independent heat was decreased in the pressure overload, while the time to peak tension was increased. The economy of the metabolic recovery process was unchanged in the pressure overload and Goldblatt preparations. In the propylthiouracil preparation the recovery processes became uneconomical. The spontaneously hypertensive rat exhibited mild cardiac hypertrophy but in all other respects the heart was unchanged from the normal animals. The thyrotoxic hearts had a high V1/V3 myosin isoenzyme ratio, which was associated with a high total activity-related heat, initial heat, and tension-dependent heat per tension time integral. The tension-independent heat was reduced in the thyrotoxic preparations. The appropriateness of each of the intracellular changes is evaluated in terms of the demands made on the heart.
Functional consequences of structural adaptation of the heart in hypertension.
Authors: Nordlander M I
Published: August 2012

Extent of myocardial shortening is inversely related to afterload. Maintenance of normal stroke volume (SV) in hypertension will therefore require elevation of cardiac performance. The question of whether left ventricular hypertrophy, which develops during chronic hypertension, enhances or depresses cardiac function has been examined experimentally. Cardiac function curves have been constructed and maximal cardiac output has been determined during rapid volume load in intact animals or in isolated perfused hearts from spontaneously hypertensive rats (SHR) and from normotensive rats. When preload, afterload, heart rate, and contractility are controlled, maximal performance is enhanced in the SHR heart, and its ability to increase contractility on elevations in afterload (homeometric autoregulation) is reset in proportion to the increase in arterial blood pressure. Although a reduced volume compliance of the SHR left ventricle has not been documented, its diastolic properties will still be influenced by the increased wall thickness. The reason is that a higher pressure is required to induce a given diastolic wall stress when wall thickness/radius ratio is increased according to Laplace's law. Since wall stress in turn determines the extent of myocardial shortening, maintenance of normal stroke volume in SHR calls for increased diastolic pressures or increased inotropic stimulation. The structural adaptation of the heart to hypertension will thus enhance its systolic performance, but will influence its diastolic properties so that secondary adjustments are required to enhance ventricular filling or the inotropic state of the heart, or both.
Cerebral vascular bed in hypertension and consequences for the brain.
Authors: Johansson B B
Published: August 2012

The internal carotid artery of spontaneously hypertensive rats and stroke-prone spontaneously hypertensive rats has a thicker media than that of normotensive Wistar Kyoto rats as early as 15 days of age; furthermore, the media-to-lumen ratio is increased in the larger pial arteries. Since several studies have indicated that the mean arterial pressure is slightly elevated in spontaneously hypertensive rats during the early postnatal period, these vascular alterations may to some extent be related to an increased pressure load. However, it seems likely that pressure-independent genetic factors are also involved. In adult spontaneously hypertensive rats the media-to-lumen ratio in the cerebral arteries is increased over a large spectrum of vessel sizes, including the brain basal arteries. The cortical surface arteries, measured through a closed cranial window in vivo, have a smaller inner diameter in spontaneously hypertensive rats than in Wistar Kyoto under resting conditions as well as during hypercapnic vasodilation. In the relaxed cerebrovascular bed the cerebral blood flow is lower in spontaneously hypertensive rats than in Wistar Kyoto at the same perfusion pressure, which is probably due mainly to a decreased internal radius in spontaneously hypertensive rats. Since the blood flow is proportional to the fourth power of the luminal radius, the lumen reduction of cerebral arteries in spontaneously hypertensive rats and stroke-prone spontaneously hypertensive rats is a potential risk factor under conditions of impending ischemia such as systemic hypotension or distal to an arterial occlusion. On the other hand, the increased media-to-lumen ratio reduces the arterial wall tension, increases the capacity to autoregulate at high blood pressure levels, and protects the blood-brain barrier.(ABSTRACT TRUNCATED AT 250 WORDS)
Intrarenal arteries in rats with early two-kidney, one clip hypertension.
Authors: Helmchen U , Bohle R M , Kneissler U , Groene H J
Published: August 2012

Structural arterial adaptation and decompensation were studied in the contralateral untouched kidneys of two-kidney, one clip hypertensive rats 1 to 64 days after constricting one renal artery. Focal necroses of intrarenal arteries were observed as early as 24 hours after starting the experiment. The necroses reached their maximum on Day 8 and thereafter decreased significantly in spite of still increasing blood pressure values. After 8 days the media thickness of the interlobular arteries was significantly increased by more than 30% and remained so until the end of the experiment. Blood pressure levels as measured by tail plethysmography were nearly normal within the first 4 days. The continuous 24-hour blood pressure recording in the conscious rats, however, showed shortlasting intermittent hypertensive spikes as early as 6 hours after renal artery constriction. In spite of these acute hypertensive peaks, which frequently exceeded 200 mm Hg, intimal lesions, potentially leading to malignant nephrosclerosis, began to appear after only 2 weeks. Thus, the development of nonobliterating, acute focal necroses of intrarenal arteries in the earliest stage of two-kidney, one clip hypertension may be explained by intermittent hypertensive episodes accompanied by a segmental overstretching of the nonadapted vascular bed. On the other hand, the occurrence of obliterating malignant nephrosclerosis in the presence of severe hypertension may also depend on the previously changed composition of the vessel walls.
Molecular studies of the atrial natriuretic factor gene.
Authors: Seidman C E , Bloch K D , Zisfein J , Smith J A , Haber E , Homcy C , Duby A D , Choi E , Graham R M , Seidman J G
Published: August 2012

The molecular biology of human atrial natriuretic factor was studied. A cloned rat cDNA probe was used to analyze tissue for the synthesis of atrial natriuretic factor, and the human gene was identified and sequenced. Nucleotide sequence comparison of human and rodent atrial natriuretic factor genes suggests regions that are critical for regulated expression of this cardiac hormone.
Synthetic atrial natriuretic factor in conscious normotensive and hypertensive rats.
Authors: Seymour A A , Marsh E A , Mazack E K , Stabilito I I , Blaine E H
Published: August 2012

Synthetic atrial natriuretic factor (Arg-Arg-Ser-Ser-Cys-Phe-Gly-Gly-Arg-Ile-Asp-Arg-Ile-Gly-Ala-Gln-Ser-Gly -Leu- Gly-Cys-Asn-Ser-Phe-Arg-Tyr-COOH [disulfide bond between cysteines]) was infused intravenously into conscious normotensive and deoxycorticosterone, one-kidney, one-clip, and two-kidney, one-clip hypertensive rats. Mean arterial pressure, urine volume, and electrolyte excretion rates were measured during a 20-minute infusion of a single dose (ranging from 0-1520 pmol/min) into each animal; 95 to 380 pmol/minute of synthetic atrial natriuretic factor maximally reduced mean arterial pressure by -20 +/- 4, -29 +/- 2, and -39 +/- 7 mm Hg in normotensive, one-kidney, one-clip, and two-kidney, one-clip hypertensive rats, respectively. In deoxycorticosterone rats, a dose of 760 pmol/minute was required to produce the largest depressor response (-58 +/- 12 mm Hg). Sodium excretion increased to 8.8 +/- 2.5 muEq/minute at 760 pmol/minute in normotensive rats, to 6.5 +/- 1.1 muEq/minute at 50 pmol/minute in deoxycorticosterone rats, and to 5.8 +/- 1.5 muEq/minute at 95 pmol/minute in one-kidney, one-clip animals. The natriuretic effect was consistently greater at all doses of synthetic atrial natriuretic factor in the two-kidney, one-clip hypertensive model, in which the maximum response was 15.3 +/- 4.7 muEq/minute at 190 pmol/minute. The changes in urine volume and excretion rates of potassium and chloride tended to parallel the increases in sodium excretion in each model. Interestingly, the maximally effective hypotensive dose of synthetic atrial natriuretic factor was different from the maximally effective natriuretic dose in all four groups.(ABSTRACT TRUNCATED AT 250 WORDS)
Effect of atrial natriuretic factor on blood pressure, renin, and aldosterone in Goldblatt hypertension.
Authors: Volpe M , Odell G , Kleinert H D , Müller F , Camargo M J , Laragh J H , Maack T , Vaughan E D , Atlas S A
Published: August 2012

We previously provided evidence that atrial natriuretic factor (ANF) antagonizes angiotensin II-induced vascular contractility and angiotensin II-stimulated aldosterone production by isolated adrenal cells. To examine the importance of these effects in vivo, synthetic ANF (auriculin A) was administered intravenously (2 micrograms/kg bolus followed by 0.3 microgram/kg/min constant infusion) to conscious, unrestrained two-kidney, one-clip and one-kidney, one-clip rats on normal sodium intake and their sham-operated controls. The one-kidney, one-clip rats also were studied on a sodium-deficient diet. Mean blood pressure, plasma renin activity, and plasma aldosterone levels were measured before and after 60-minute infusion. In saralasin-responsive two-kidney, one-clip rats (n = 10), ANF administration reduced blood pressure (from 187 +/- 11 [SE] to 153 +/- 11 mm Hg; p less than 0.001) and plasma aldosterone levels (from 182 +/- 61 to 125 +/- 60 ng/dl; p less than 0.05), while plasma renin activity increased (from 59 +/- 16 to 82 +/- 20 ng/ml/hr; p less than 0.05). Lesser changes in blood pressure occurred in saralasin-nonresponsive two-kidney, one-clip rats (149 +/- 10 to 143 +/- 8 mm Hg; n = 5), sodium-replete one-kidney, one-clip rats (183 +/- 9 to 170 +/- 11 mm Hg; n = 9), two-kidney sham-operated rats (122 +/- 3 to 115 +/- 4 mm Hg; n = 8), and one-kidney sham-operated rats (117 +/- 3 to 112 +/- 3 mm Hg; n = 7). Control plasma renin and aldosterone levels were not elevated in these latter groups and did not change significantly with ANF administration. In sodium-depleted one-kidney, one-clip rats, which became saralasin responsive, ANF administration significantly reduced blood pressure (from 184 +/- 11 to 156 +/- 12 mm Hg; n = 8), plasma aldosterone levels (from 286 +/- 41 to 179 +/- 36 ng/dl), and plasma renin activity (from 69 +/- 19 to 44 +/- 13 ng/ml/hr).(ABSTRACT TRUNCATED AT 250 WORDS)
The Long-Term Effect of Coronary Stenting on Epicardial and Microvascular Endothelial Function
Authors: Lim Seong-Hoon , Flammer Andreas J. , Yoon Myeong Ho , Lennon Ryan J. , Gulati Rajiv , Mathew Verghese , Rihal Charanjit S. , Lerman Lilach O. , Lerman Amir
Published: August 2012

Background—

Coronary stents, drug-eluting stents in particular, have been linked to coronary epicardial endothelial dysfunction after implantation. However, less is known about their impact on coronary microvascular function and their long-term effects on the vasculature.

Methods and Results—

We evaluated 71 patients (mean age, 53.0±10.1 years) with chest pain and angiographically nonsignificant coronary artery disease 17.1±17.1 months after left anterior descending coronary artery stenting. Seventy-one age- and sex-matched patients (mean age, 53.0±10.3 years) with chest pain but no prior coronary intervention served as controls. Coronary blood flow in response to the endothelium-dependent vasodilator acetylcholine as well as the microvascular (endothelium-independent) coronary flow reserve in response to intracoronary adenosine were evaluated. Quantitative coronary angiography was used to study epicardial diameter changes to acetylcholine. Microcirculatory function was not significantly different between the stenting and control groups (median [interquartile range] coronary flow reserve, 2.9 [2.5–3.4] versus 3.0 [2.4–3.4] mL/min,
P
=0.24; change of coronary blood flow, 34.9% [−34.4% to 90.0%] versus 54.7% [−5.6% to 104.6%],
P
=0.18). Both groups exhibited epicardial endothelial dysfunction (−23.0% [−47.4% to −7.6%] versus −20.0% [−40.0% to 0.0%],
P
=0.4). Results did not differ between patients with drug-eluting stents (n=46) and patients with bare-metal stents (n=24).

Conclusions—

This study demonstrates that in patients with coronary arteries in which a stent has been placed, coronary microcirculatory and epicardial vascular function are not significantly different from that of an age- and sex-matched population with similar symptoms but nonsignificant coronary artery disease.
Cytokine Therapy With Interleukin-2/Anti–Interleukin-2 Monoclonal Antibody Complexes Expands CD4+CD25+Foxp3+ Regulatory T Cells and Attenuates Development and Progression of Atherosclerosis
Authors: Dinh Tam Nguyen , Kyaw Tin Soe , Kanellakis Peter , To Kelly , Tipping Peter , Toh Ban-Hock , Bobik Alexander , Agrotis Alex
Published: August 2012

Background—

CD4+CD25+Foxp3+ regulatory T cells (Tregs) attenuate atherosclerosis, but their therapeutic application by adoptive transfer is limited by the need for their expansion in vitro and limited purity. Recently, an interleukin (IL)-2/anti–IL-2 neutralizing monoclonal antibody (IL-2/anti–IL-2 mAb) complex has been shown to expand these Tregs. We examined the capacity of a modified IL-2/anti–IL-2 mAb treatment to expand Tregs and inhibit both the progression and development of developed atherosclerosis.

Methods and Results—

Six-week old apolipoprotein E–deficient mice fed a high-fat diet for 8 weeks were administered IL-2/anti–IL-2 mAb commencing 2 weeks after starting the diet. Tregs in the spleen, lymph node, and liver were selectively expanded without affecting CD4+, CD8+, or natural killer cells. Tregs were increased in lesions and lesion size reduced. CD4+ T-cells, macrophages, mature dendritic cells, proliferating cell nuclear antigen+ cells, and monocyte chemoattractant protein-1 and vascular cell adhesion molecule-1 were reduced. In anti-CD3–stimulated splenocytes, proliferation and secretion of Th1, Th2, and Th17 (IL-17) cytokines and IL-1β were reduced. To determine whether treatment attenuated progression of developed atherosclerosis, 6-week-old apolipoprotein E–deficient mice were fed a high-fat diet for 6 weeks, followed by IL-2/anti–IL-2 mAb treatment for 6 weeks while continuing the high-fat diet. Treatment also increased Tregs without affecting CD4+, CD8+, or natural killer cells, suppressed inflammation, and greatly attenuated progression of atherosclerosis.

Conclusions—

IL-2/anti–IL-2 mAb treatment in vivo attenuates atherosclerosis via selective Tregs expansion. The findings suggest that cytokine-based IL-2/anti–IL-2 mAb complex therapy could represent an attractive approach for treating atherosclerosis, because it markedly attenuates progression as well as development, by modulating its immunoinflammatory component.
Orthostatic Tolerance Testing in a Prospective Cohort of Adolescents With Chronic Fatigue Syndrome and Recovered Controls Following Infectious Mononucleosis
Authors: Katz Ben Z. , Stewart Julian M. , Shiraishi Yukiko , Mears Cynthia J. , Taylor Renee
Published: August 2012

Chronic fatigue syndrome (CFS) is a complex condition responsible for marked functional impairment. The authors recently reported that 6 months following acute infectious mononucleosis (IM), 13%, of adolescents met criteria for CFS. The authors’ objective was to assess standing orthostatic tolerance (SOT) in adolescents with CFS and in controls 6 months following IM. In all, 36 of 39 adolescents diagnosed with CFS 6 months following IM and 43 of 50 recovered controls had SOT testing (SOTT) performed. χ2 Analysis was performed to study the relationships between SOTT and the diagnosis of CFS. Adolescents diagnosed with CFS and recovered controls did not differ significantly in age, weight, or body mass index. The authors found that 9 of 36 adolescents with CFS (25%) versus 9 of 43 recovered controls (21%) had an abnormal SOTT, which was not a statistically significant difference. Adolescents who meet criteria for CFS 6 months following IM do not have, as a group, more standing orthostatic intolerance than recovered controls.
Social relationships and postpartum depression in South Asia: A systematic review
Authors: Jones Eleri , Coast Ernestina
Published: August 2012

Background:

Evidence suggests a much higher prevalence of postpartum depression in South Asia than in ‘western’ contexts.

Aim:

To conduct a rapid systematic review of evidence on the association between social relationships and postpartum depression in South Asia.

Methods:

Five databases were searched to identify relevant studies. Studies meeting the selection and quality criteria were analysed and integrated in a narrative review.

Results:

Nine mostly quantitative studies were included in the review. Low support and poor relationships with the husband and parents-in-law were associated with postpartum depression, although associations were weakened in multivariate analyses. The different dimensions of support have not yet been systematically investigated and the likely complex interrelationships between social relationship risk factors are not yet well understood.

Conclusions:

Findings mirror those from ‘western’ contexts, showing the key role of social relationships in the aetiology of postpartum depression. Yet, they also reinforce the hypothesis that the social and cultural context influences the association. The importance of relationships with the extended family, as well as the husband, in South Asia is highlighted. Further research is recommended to develop an understanding of these relationships to better inform interventions.
Unfolding the Phenomenological Research Process
Authors: Finlay Linda
Published: August 2012

Phenomenological researchers generally agree that our central concern is to return to embodied, experiential meanings aiming for fresh, complex, rich description of phenomena as concretely lived. Yet when it comes to deciding how best to carry out this research in practice debates abound. Some approaches to phenomenology emphasize description; others interpretive layers. Some insist on a rigorous, scientific method; others seek more poetic, artistic flourish. In this article, the author offers preliminary thoughts about what unites seemingly divergent phenomenological research approaches. She suggests that the essence of the phenomenological research approach encompasses five mutually dependent and dynamically iterative processes: (a) embracing the phenomenological attitude, (b) entering the lifeworld (through descriptions of experiences), (c) dwelling with horizons of implicit meanings, (d) explicating the phenomenon holistically, and (e) integrating frames of reference. The author argues that studies that focus on experience are not necessarily phenomenological. The line being contested is the extent a study goes beyond subjectivity and into the broader realm of lifeworld experience.
The Classification of Extranet Attributes in Terms of Their Asymmetric Influences on Overall User Satisfaction
Authors: Caber Meltem , Albayrak Tahir , Loiacono Eleanor T.
Published: August 2012

Information systems (IS), such as Internet applications, are widely used by the tourism and travel industry. Extranets, in particular, allow controlled access of outside organizations into a company’s internal systems. In the travel industry, these technological applications are generated and supplied by tour operators and used by travel agents to conduct their business. Use of an extranet is of benefit to a travel operator who gains more revenue if travel agents select or recommend its particular products. This article classifies the attributes of a tour operator’s extranet system in terms of its asymmetric influence on its user (travel agency sales representatives) satisfaction. In addition, a revised version of impact-asymmetry analysis is presented, called asymmetric impact-performance analysis, which is a simple and visual technique that assesses the key attributes for increasing overall user satisfaction.
Is there any difference between blood and crystalloid cardioplegia for myocardial protection during cardiac surgery? A meta-analysis of 5576 patients from 36 randomized trials
Authors: Sá MPBO , Rueda FG , Ferraz PE , Chalegre ST , Vasconcelos FP , Lima RC
Published: August 2012

Objective:

To compare the efficacy of blood versus crystalloid cardioplegia for myocardial protection in patients undergoing cardiac surgery.

Methods:

MEDLINE, EMBASE, CENTRAL/CCTR, SciELO, LILACS, Google Scholar and reference lists of relevant articles were searched for clinical studies that reported in-hospital outcomes after blood or crystalloid cardioplegia for myocardial protection during cardiac surgery procedures from 1966 to 2011. The principal summary measures were risk ratio (RR) for blood compared to crystalloid cardioplegia with 95% Confidence Interval (CI) and P values (considered statistically significant when <0.05). The RRs were combined across studies using the DerSimonian-Laird random effects model and fixed effects model using the Mantel-Haenszel model - both models were weighted. The meta-analysis was completed using the software Comprehensive Meta-Analysis version 2 (Biostat Inc., Englewood, New Jersey).

Results:

Thirty-six studies (randomized trials) were identified and included a total of 5576 patients (2834 for blood and 2742 for crystalloid). There was no significant difference between the blood and crystalloid groups in the risk for death (risk ratio [RR] 0.951, 95% CI 0.598 to 1.514, P=0.828, for both effect models) or myocardial infarction (RR 0.795, 95% CI 0.547 to 1.118, P=0.164, for both effect models) or low cardiac output syndrome (RR 0.765, 95% CI 0.580 to 1.142, P=0.094, for the fixed effect model; RR 0.690, 95% CI 0.480 to 1.042, P=0.072, for the random effect model). It was observed that there was no publication bias or heterogeneity of effects about any outcome.

Conclusion:

We found evidence that argues against any superiority in terms of hard outcomes between blood or crystalloid cardioplegia for myocardial protection during cardiac surgery.
An aerobic walking programme versus muscle strengthening programme for chronic low back pain: a randomized controlled trial
Authors: Shnayderman Ilana , Katz-Leurer Michal
Published: August 2012

Objective:

To assess the effect of aerobic walking training as compared to active training, which includes muscle strengthening, on functional abilities among patients with chronic low back pain.

Design:

Randomized controlled clinical trial with blind assessors.

Setting:

Outpatient clinic.

Subjects:

Fifty-two sedentary patients, aged 18–65 years with chronic low back pain. Patients who were post surgery, post trauma, with cardiovascular problems, and with oncological disease were excluded.

Intervention:

Experimental ‘walking’ group: moderate intense treadmill walking; control ‘exercise’ group: specific low back exercise; both, twice a week for six weeks.

Main measures:

Six-minute walking test, Fear-Avoidance Belief Questionnaire, back and abdomen muscle endurance tests, Oswestry Disability Questionnaire, Low Back Pain Functional Scale (LBPFS).

Results:

Significant improvements were noted in all outcome measures in both groups with non-significant difference between groups. The mean distance in metres covered during 6 minutes increased by 70.7 (95% confidence interval (CI) 12.3–127.7) in the ‘walking’ group and by 43.8 (95% CI 19.6–68.0) in the ‘exercise’ group. The trunk flexor endurance test showed significant improvement in both groups, increasing by 0.6 (95% CI 0.0–1.1) in the ‘walking’ group and by 1.1 (95% CI 0.3–1.8) in the ‘exercise’ group.

Conclusions:

A six-week walk training programme was as effective as six weeks of specific strengthening exercises programme for the low back.
Residual strain measurement for arc welding and localised high-pressure rolling using resistance strain gauges and neutron diffraction
Authors: Coules Harry E , Cozzolino Luis D , Colegrove Paul , Ganguly Supriyo , Wen Shuwen , Pirling Thilo
Published: August 2012

Neutron diffraction and foil resistance strain gauges have been used to study the state of residual stress introduced by localised high-pressure rolling of structural steel plates, and compare it to that caused by gas metal arc welding. Rolling creates a region in which the residual stress state is highly compressive in the rolling direction. Furthermore, this region is sharply defined, making it potentially very suitable for cancelling out the tensile residual stresses caused by welding. It is also demonstrated that non-destructive strain measurements made during the welding and rolling processes can be used to indicate residual elastic strain and stress, and that this method shows good agreement with conventional neutron diffraction measurements. Determination of residual stresses in this way requires consideration of the effect of curvature on the values of strain measured at the surface of the object.
Learning Chronobiology by Improving Wikipedia
Authors: Chiang C.D. , Lewis C.L. , Wright M.D.E. , Agapova S. , Akers B. , Azad T.D. , Banerjee K. , Carrera P. , Chen A. , Chen J. , Chi X. , Chiou J. , Cooper J. , Czurylo M. , Downs C. , Ebstein S.Y. , Fahey P.G. , Goldman J.W. , Grieff A. , Hsiung S. , Hu R. , Huang Y. , Kapuria A. , Li K. , Marcu I. , Moore S.H. , Moseley A.C. , Nauman N. , Ness K.M. , Ngai D.M. , Panzer A. , Peters P. , Qin E.Y. , Sadhu S. , Sariol A. , Schellhase A. , Schoer M.B. , Steinberg M. , Surick G. , Tsai C.A. , Underwood K. , Wang A. , Wang M.H. , Wang V.M. , Westrich D. , Yockey L.J. , Zhang L. , Herzog E.D.
Published: August 2012

Although chronobiology is of growing interest to scientists, physicians, and the general public, access to recent discoveries and historical perspectives is limited. Wikipedia is an online, user-written encyclopedia that could enhance public access to current understanding in chronobiology. However, Wikipedia is lacking important information and is not universally trusted. Here, 46 students in a university course edited Wikipedia to enhance public access to important discoveries in chronobiology. Students worked for an average of 9 h each to evaluate the primary literature and available Wikipedia information, nominated sites for editing, and, after voting, edited the 15 Wikipedia pages they determined to be highest priorities. This assignment ( http://www.nslc.wustl.edu/courses/Bio4030/wikipedia_project.html ) was easy to implement, required relatively short time commitments from the professor and students, and had measurable impacts on Wikipedia and the students. Students created 3 new Wikipedia sites, edited 12 additional sites, and cited 347 peer-reviewed articles. The targeted sites all became top hits in online search engines. Because their writing was and will be read by a worldwide audience, students found the experience rewarding. Students reported significantly increased comfort with reading, critiquing, and summarizing primary literature and benefited from seeing their work edited by other scientists and editors of Wikipedia. We conclude that, in a short project, students can assist in making chronobiology widely accessible and learn from the editorial process.
Photic Sensitivity for Circadian Response to Light Varies with Photoperiod
Authors: Glickman Gena , Webb Ian C. , Elliott Jeffrey A. , Baltazar Ricardo M. , Reale Meghan E. , Lehman Michael N. , Gorman Michael R.
Published: August 2012

The response of the circadian system to light varies markedly depending on photic history. Under short day lengths, hamsters exhibit larger maximal light-induced phase shifts as compared with those under longer photoperiods. However, effects of photoperiod length on sensitivity to subsaturating light remain unknown. Here, Syrian hamsters were entrained to long or short photoperiods and subsequently exposed to a 15-min light pulse across a range of irradiances (0-68.03 µW/cm2) to phase shift activity rhythms. Phase advances exhibited a dose response, with increasing irradiances eliciting greater phase resetting in both conditions. Photic sensitivity, as measured by the half-saturation constant, was increased 40-fold in the short photoperiod condition. In addition, irradiances that generated similar phase advances under short and long days produced equivalent phase delays, and equal photon doses produced larger delays in the short photoperiod condition. Mechanistically, equivalent light exposure induced greater pERK, PER1, and cFOS immunoreactivity in the suprachiasmatic nuclei of animals under shorter days. Patterns of immunoreactivity in all 3 proteins were related to the size of the phase shift rather than the intensity of the photic stimulus, suggesting that photoperiod modulation of light sensitivity lies upstream of these events within the signal transduction cascade. This modulation of light sensitivity by photoperiod means that considerably less light is necessary to elicit a circadian response under the relatively shorter days of winter, extending upon the known seasonal changes in sensitivity of sensory systems. Further characterizing the mechanisms by which photoperiod alters photic response may provide a potent tool for optimizing light treatment for circadian and affective disorders in humans.
Polythiophene/Na-montmorillonite composites via intercalative polymerization
Authors: Çelik Meltem , Önal Müşerref
Published: August 2012

Conducting polythiophene (PTP)/Na-montmorillonite (Na-MMT) composites have been prepared by intercalative polymerization. The synthesized composites are characterized by Fourier transform infrared spectroscopy, x-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy (TEM), and thermal analysis. XRD  and TEM images showed that the PTP was intercalated into the clay layers. The thermogravimetric analysis and the differential thermal analysis revealed the introduction of Na-MMT results in thermal stability of composites with respect to pure PTP. Furthermore, adsorptive properties, the moisture retention, and water uptake values of composites were investigated. Conductivity behavior of composites was also studied.
Qualitative assessment of nanoclay dispersion using thermogravimetric analysis
Authors: Shahabadi Seyed Ismail Seyed , Garmabi Hamid
Published: August 2012

A method is presented for qualitative assessment of nanoclay dispersion in a polymeric matrix, which is based on the effect of nanoclay dispersion on the thermal stability of polymer/nanoclay (PNC) systems. The method offers a fast, inexpensive macroscopic evaluation of nanoclay dispersion, which can be used for direct comparison of nanoclay dispersion in PNC samples. Using experimental design, it is also possible to discover material or process conditions that lead to desirable nanoclay dispersion. Furthermore, this method can be employed for confirmation purposes in support of other nanoclay dispersion assessment techniques. We proved this finding by means of six different independently obtained pieces of information on the quality of nanoclay dispersion in the samples, which are x-ray diffraction, atomic force microscopy, transmission electron microscopy, gas permeability, as well as mechanical and rheological measurements. We believe this method could be employed to study nanoclay dispersion in thermoset matrices as well, for which utilizing other techniques may be either unfeasible or difficult; therefore, this method could present an alternative for assessing nanoclay dispersion in this class of polymeric materials.
The mechanical and tribological properties of CF/PPS composite filled with PA6
Authors: Jian Li , Tao Sun
Published: August 2012

The mechanical and friction and wear behaviors of carbon fiber/polyphenylene sulfide (CF/PPS) composite and polyamide 6 (PA6)-filled CF/PPS (CF/PA6/PPS) composites were investigated. The addition of 2 vol%, 4 vol% and 6 vol% PA6 increases the bending strength of CF/PPS composite. In order to further understand the wear mechanisms, the worn surfaces of samples were analyzed by scanning electron microscopy (SEM). The experimental results indicated that the wear loss and the friction coefficient of CF/PPS composite decreased with the addition of PA6 particles. The main wear mechanisms under dry sliding condition are the plastic deformation and mechanical microploughing.
Affiliation or appropriation? Crossing and the politics of race among children in New York City
Authors: Kromidas Maria
Published: August 2012

Based on ethnographic research in a diverse New York City neighborhood, this article examines issues surrounding the practice of crossing from children’s perspectives. Crossing refers to the use of language varieties to which one does not have conventional access, practices that could be disparaging or affiliative. The author explores how children distinguished the two types through the principle of authenticity, itself derived by means that went beyond the usual determinants of blood, birth and bodies. While playful, the author argues that crossings were one way for children to participate in the everyday politics of difference and critique the existing racial order.
On the irrelevance of ethnicity in children’s organization of their social world
Authors: Sedano Livia Jiménez
Published: August 2012

When studying the ways of structuring social life in general, and the socialization processes of children in particular, ethnicity is often taken for granted as a basic axis along which people distribute themselves into groups. Most anthropological studies describe and classify agents in ethnic terms. This articles argue that ethnicity is not always a relevant principle of order in the social fields of children, at least in the ethnographic cases studied. The article provides a critical reflection on the theoretical frameworks and methodologies based on the idea of ‘ethnic groups’ as a starting point for doing anthropological research.
A parallel manipulator inspired by the original Stewart platform
Authors: Gallardo-Alvarado J , García-Murillo MA
Published: August 2012

This study addresses the kinematics of a new parallel manipulator inspired by the eight-bar linkage proposed as a flight simulator by Stewart almost five decades ago. Due to its partially decoupled topology, the forward displacement analysis of the robot is obtained in a nearly closed-form solution. The input–output equations of velocity and acceleration of the manipulator are systematically derived by resorting to reciprocal-screw theory. Numerical examples are included in the contribution in order to show the application of the method of kinematic analysis. As far as the authors are aware, the topology proposed in this contribution has not been reported in previous works.
Independence of Data-Driven and Conceptually Driven Priming
Authors: Boehm Stephan G. , Sommer Werner
Published: August 2012

A central tenet of current memory theories is the independence of data-driven and conceptually driven priming. Although these types of repetition priming have different functional properties, it has remained unclear whether they are independent and additive or interact with each other. Therefore, we orthogonally combined these priming types in two experiments requiring occupation judgments for celebrities, represented by their faces or names. In both experiments, the sum of the effects of separate data-driven priming and conceptually driven priming equaled the effect of the combination of these priming types. These findings demonstrate for the first time the independence of data-driven and conceptually driven priming and so confirm a central tenet of current memory theories. This independence may thus be an important element for the development of future overarching memory theories.
Social Identification Structures the Effects of Perspective Taking
Authors: Tarrant Mark , Calitri Raff , Weston Dale
Published: August 2012

Researchers who study perspective taking are generally optimistic about the potential for interventions to improve intergroup perceptions. The current research provides new insight into the conditions that frame the intergroup outcomes of perspective taking. The results show that the effects of perspective taking are not always positive but depend on perspective takers’ degree of identification with the in-group. In two experiments, we demonstrated that adopting the perspective of an out-group member can have damaging effects on intergroup perceptions among group members who are highly identified with the in-group. Specifically, compared with less committed members, those who identified highly with the in-group used a greater number of negative traits to describe the out-group following perspective taking. Such perspective taking also led participants with high in-group identification to judge the out-group less favorably. Understanding how social identity concerns frame the outcome of perspective taking is crucial to its effective employment in intergroup-relations programs.
Complement fragment C3d is colocalized within the lipid rafts of T cells and promotes cytokine production
Authors: Borschukova O , Paz Z , Ghiran IC , Liu C-C , Kao AH , Manzi S , Ahearn JM , Tsokos GC
Published: August 2012

The complement system plays an important role in tissue inflammation and damage in SLE patients. High levels of C3d were detected on the surface of erythrocytes and lymphocytes of SLE patients. The objective of this study was to assess the functional consequences of C3d fragments deposited on the surface membrane of SLE T cells. Methods: 46 SLE patients, 43 patients with other autoimmune diseases (OAD) and 33 healthy individuals (N) were enrolled in this study. T cells were isolated from peripheral blood and flow cytometry studies were conducted to assess the levels of C3d fragments, Ca++ influx responses and cytokine production. Confocal microscopy was used to study co-localized molecules. Student’s t-test was performed to determine statistical significance among study groups. Results: A significant percentage of the SLE T cells were found to be positive for C3d (13.58 ± 3.92%) when compared with normal T cells (4.52 ± 2.92%) ( p < 0.0000547) and T cells from patients with other autoimmune diseases (6.31 ± 4.57%) ( p < 0.00513). Peak Ca++ influx responses were significantly higher in C3d− SLE T cells compared with C3d+ SLE T cells ( p < 0.011). C3d+ T cells produced significantly more IL-2, IFN-gamma, IL-4 and IL-17. In contrast to the increased production of IL-2 by the C3d+ T cells, the overall SLE T cell population produced less IL-2 when compared with T cells from normal individuals or patients with other autoimmune disease. The C3d fragments were found to be localized within the lipid rafts. Conclusion: C3d fragments are localized in the lipid rafts of SLE T cells and contribute to abnormal T cell function by modulating Ca++ influx responses and increased cytokine production.
Facilitating Innovation in Diverse Science Teams Through Integrative Capacity
Authors: Salazar Maritza R. , Lant Theresa K. , Fiore Stephen M. , Salas Eduardo
Published: August 2012

Knowledge integration in diverse teams depends on their integrative capacity—the social and cognitive processes, along with emergent states, that shape a team’s ability to combine diverse knowledge. We argue that integrative capacity represents the potential that a team has to overcome various compositional, team, and contextual barriers to generating integrated and novel knowledge. This article focuses specifically on the unique challenges facing diverse science teams that have the goal of generating novel knowledge at the intersection of disciplinary, practice, and organizational boundaries. The integrative capacity of a science team is argued to help facilitate the social and cognitive integration processes necessary for effective team processes that enhance the likelihood of innovative team outcomes. Implications of our theoretical framework for practice and research on fostering innovation in diverse science teams are discussed.