bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative MR measurements of regional and global left ventricular function and strain after intramyocardial transfer of VM202 into infarcted swine myocardium
Authors: Carlsson Marcus , Osman Nael F. , Ursell Philip C. , Martin Alastair J. , Saeed Maythem
Published: June 2008

Previous studies have shown the beneficial effects of the hepatocyte growth factor (HGF) gene on myocardial perfusion and infarction size but not on the regional strain in relationship to global left ventricular function. A noninvasive magnetic resonance (MR) study was performed to determine the effect of a new HGF gene, VM202, expressing two isoforms of HGF, on regional and global left ventricular function. Pigs (8/group) were divided into three groups: 1) controls without infarction; 2) reperfused, infarcted controls; and 3) infarcted, treated (1 h after reperfusion) with VM202 injected at eight sites. Cine, tagging, and delayed enhancement MR images were acquired at 3 and 50 ± 3 days after infarction. At 50 days, ejection fraction in infarcted, treated animals increased (38 ± 1% to 47 ± 2%, P < 0.01) to the level of controls without infarction (52 ± 1%, P = 0.16) but decreased in infarcted controls (41 ± 1% to 37 ± 1%, P < 0.05). Two-dimensional strain improved in remote, peri-infarcted, and infarcted myocardium. Furthermore, the infarction size was smaller in infarcted, treated animals (7.0 ± 0.5%) compared with infarcted controls (13.2 ± 1.6%, P < 0.05). Histopathology showed a lack of hypertrophy in myocytes in peri-infarcted and remote myocardium and the formation of islands/peninsulas of myocytes in infarcted, treated animals but not in infarcted controls. In conclusion, the plasmid HGF gene caused a near complete recovery of ejection fraction and improved the radial and circumferential strain of remote, peri-infarcted, and infarcted regions within 50 days. These beneficial effects may be explained by the combined effects of a speedy and significant infarct resorption and island/peninsulas of hypertrophied myocytes within the infarcted territory but not by compensatory hypertrophy. The combined use of cine and tagging MR imaging provides valuable information on the efficacy of gene therapy.
Oxygen transport during hemodilution with a perfluorocarbon-based oxygen carrier: effect of altitude and hyperoxia
Authors: Gardeazábal Tatiana , Cabrera Mariana , Cabrales Pedro , Intaglietta Marcos , Briceño Juan Carlos
Published: June 2008

Oxygen delivery and consumption after hemodilution with a perfluorocarbon-based oxygen carrier (PFCOC) was evaluated at sea level and at 2,600 m above sea level. Fifteen anesthetized rats were subjected to a two-exchange normovolemic hemodilution of 40% of the circulating blood volume each. First exchange was performed with a colloid solution. Second exchange was with 80% PFCOC and 20% colloid. Animals were then ventilated with 100% oxygen. Experiments were performed at barometric pressure of 1.0 atm (sea-level group, n = 9) or 0.74 atm (2,600-m group, n = 6). Blood gases, hematocrit, fluorocrit, and hemoglobin content were measured at baseline and 15 min after each exchange. After hemodilution, total arterial content was not modified by the PFCOC in either group. In contrast, arteriovenous oxygen difference increased significantly in both groups, as did the oxygen extraction ratio. In the second exchange, although total arterial content was similar between the two groups, the perfluorocarbon and plasma phases contributed significantly more at sea level. Arteriovenous oxygen difference was significantly less at sea level with a higher contribution from the perfluorocarbon and plasma phases. In conclusion, hemodilution with a PFCOC induced changes in oxygen delivery and consumption that differ with altitude. The 2,600-m group exhibited a higher oxygen extraction ratio and arteriovenous oxygen difference, with reduced oxygen delivery and unloading from both the fluorocarbon and plasma phase. Therefore, the efficacy of PFCOCs at 2,600 m above sea level is reduced, and altitude must be taken into account when PFCOCs are used.
Effects of particulates and lipids on the hydraulic conductivity of Matrigel
Authors: McCarty William J. , Chimento Melissa F. , Curcio Christine A. , Johnson Mark
Published: June 2008

The hydraulic conductivity of a connective tissue is determined both by the fine ultrastructure of the extracellular matrix and the effects of larger particles in the interstitial space. In this study, we explored this relationship by examining the effects of 30- or 90-nm-diameter latex nanospheres or low-density lipoproteins (LDL) on the hydraulic conductivity of Matrigel, a basement membrane matrix. The hydraulic conductivity of Matrigel with latex nanospheres or LDL particles added at 4.8% weight fraction was measured and compared with the hydraulic conductivity of Matrigel alone. The LDL-derived lipids in the gel were visualized by transmission electron microscopy and were seen to have aggregated into particles up to 500 nm in size. The addition of these materials to the medium markedly decreased its hydraulic conductivity, with the LDL-derived lipids having a much larger effect than did the latex nanospheres. Debye-Brinkman theory was used to predict the effect of addition of particles to the hydraulic conductivity of the medium. The theoretical predictions matched well with the results from adding latex nanospheres to the medium. However, LDL decreased hydraulic conductivity much more than was predicted by the theory. The validation of the theoretical model for rigid particles embedded in extracellular matrix suggests that it could be used to make predictions about the influence of particulates (e.g., collagen, elastin, cells) on the hydraulic conductivity of the fine filamentous matrix (the proteoglycans) in connective tissues. In addition, the larger-than-predicted effects of lipidlike particles on hydraulic conductivity may magnify the pathology associated with lipid accumulation, such as in Bruch's membrane of the retina during macular degeneration and the blood vessel wall in atherosclerosis.
Fat oxidation rate and the exercise intensity that elicits maximal fat oxidation decreases with pubertal status in young male subjects
Authors: Riddell M. C. , Jamnik V. K. , Iscoe K. E. , Timmons Brian W. , Gledhill N.
Published: June 2008

The range of exercise intensities that elicit high fat oxidation rates (FOR) in youth and the influence of pubertal status on peak FOR are unknown. In a longitudinal design, we compared FOR over a range of exercise intensities in a small cohort of developing prepubertal male subjects. Five boys all at Tanner stage 1 (ages 11–12 yr) and nine men (ages 20–26 yr) underwent an incremental cycle ergometry test to volitional exhaustion. FOR curves were determined from indirect calorimetry during the final 30 s of each increment. The same protocol was duplicated annually in the boys as they progressed through puberty. The peak FOR was considerably higher ( P < 0.05) in boys at Tanner 1 (8.6 ± 1.5 mg·kg lean body mass−1·min−1) (mean ± SD) compared with men (4.2 ± 1.1 mg·kg lean body mass−1·min−1). FOR dropped as boys developed through puberty (Tanner 2/3 peak rate = 7.6 ± 0.6 mg·kg lean body mass−1·min−1; Tanner 4 peak rate = 5.4 ± 1.8 mg·kg lean body mass−1·min−1, main effect of Tanner stage; P < 0.05) to the levels found in men (not significant). The exercise intensity that elicited peak FOR was higher in the boys at Tanner 1 [56 ± 6% peak aerobic power (V̇o2 peak)] than in men (31 ± 4% V̇o2 peak) ( P < 0.001). This value tended to decrease by Tanner stage 4 (45 ± 10% V̇o2 peak, main effect of Tanner stage; P = 0.06). We conclude that, compared with men, prepubertal boys have higher relative FOR throughout a wide range of exercise intensities and that FOR drops as boys develop through puberty.
Incontinencia fecal funcional en niños
Authors: Bongers Marloes E.J. , Benninga Marc A.
Published: June 2008

La incontinencia fecal se define como la evacuación de deposiciones fecales en un lugar inadecuado. Este molesto síntoma es el origen de malestar y turbación considerables tanto para el niño o niña como para su familia. La incontinencia fecal pediátrica puede dividirse en dos categorías principales: (1) Incontinencia fecal orgánica resultante, por ejemplo, de malformaciones anorrectales o anomalías neurógenas; (2) incontinencia fecal funcional. En esta revisión abordaremos únicamente la incontinencia fecal funcional en niños y comentaremos la definición, la epidemiología, la fisiopatología y las actualizaciones recientes sobre aspectos clínicos y diagnósticos de la incontinencia fecal funcional.
A Leptin Serum Concentration Less than 10 ng/ml Is a Predictive Marker of Outcome in Patients with Moderate to Severe Secondary Peritonitis
Authors: Bracho-Riquelme R.L. , Reyes-Romero M.A. , Pescador N. , Flores-García A.I.
Published: June 2008

Introduction: Leptin is involved in the sepsis syndrome. A possible relationship exists between low leptin levels and peritonitis severity and a poorer prognosis. Objectives: We aimed to corroborate the relationship between low leptin serum levels and death in patients with peritonitis and to explore the associations between leptin and interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-13 (IL-13), tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP). Methods: In 230 adult patients with surgically confirmed secondary peritonitis, the Mannheim Peritonitis Index and the serum concentrations of leptin, IL-6, IL-10, IL-13, TNF-α and CRP were determined. Two cohorts were established (leptin ≤10 ng/ml and >10 ng/ml). Death or survival was followed through 30 days. The relationship between leptin (≤10 ng/ml) and death was evaluated using the accumulated incidence ratio (AIR). The association of leptin (dependent variable) with IL-6, IL-10, IL-13, TNF-α and CRP (independent variables) was studied by regression analysis. Results: The general mortality rate was 7.8% and the death AIR was 3.15 (p nonsignificant). A subsample of patients with a Mannheim Peritonitis Index ≧21 was studied, showing a significant AIR of 4.26 (p = 0.017). Regression analysis determined an association only between leptin and IL-6 (p < 0.001), IL-10 (p < 0.047) and CRP (p < 0.001). Discussion: A serum leptin below the threshold of 10 ng/ml is an adverse prognostic marker in patients with moderate to severe secondary peritonitis. The results of the regression analysis suggest that the mechanisms involved are opposing, in that leptin associated with IL-6 has a proinflammatory effect and, through IL-10 and CRP production, restrains the inflammatory response.
Historical and Clinical Perspectives of the Expanded Disability Status Scale
Authors: Kurtzke John F.
Published: June 2008

Background: The measurement of neurologic impairment in multiple sclerosis (MS) is of importance in treatment trials and course of illness. Methods: This review describes the rationale underlying the formation and use of a bifid rating system, the (Expanded) Disability Status Scale (DSS) and the Functional Systems (FS). Results: All signs found at neurologic examination in MS can be consolidated into 8 mutually exclusive FS: pyramidal, cerebellar, brain stem, sensory, bowel and bladder, visual, cerebral and other, each of which, save ‘other’, is given ordinal grades from 0 to 5 or 6. Each FS correlates with the DSS, a step scale from 0 (normal) to 10 (death due to MS), which is an overall measure of neurologic abnormality. Dividing steps 1–9 each into 2 gives the Expanded DSS. The FS and DSS were used in an Army series to describe neurologic status at first diagnosis and over the first 20 years of illness. DSS severity at 5 years after onset, but not earlier, was highly predictive of later severity. Conclusions: Combination of the (Expanded) DSS and FS has been used successfully to assess impairment for natural history and treatment studies in MS.
Amyotrophic Lateral Sclerosis among 1991 Gulf War Veterans: Evidence for a Time-Limited Outbreak
Authors: Horner Ronnie D. , Grambow Steven C. , Coffman Cynthia J. , Lindquist Jennifer H. , Oddone Eugene Z. , Allen Kelli D. , Kasarskis Edward J.
Published: June 2008

Background: In follow-up to recent reports of an elevated risk of amyotrophic lateral sclerosis (ALS) among 1991 Gulf War veterans, we analyzed the distribution of disease onset times to determine whether the excess risk was time limited. Methods: This secondary analysis used data from a population-based series of ALS cases identified between 1991 and 2001 among the 2.5 million military personnel who were on active duty during the 1991 Gulf War. Annual standardized incidence ratios (SIR) were calculated for all cases and for those with disease onset before age 45 years. Results: Forty-eight of 124 cases occurred among those deployed to the Persian Gulf region during the war. The annual SIR for deployed military personnel did not demonstrate a monotonically increasing trend for either all cases (χ2 = 0.11, d.f. = 1, p = 0.74) or for cases under 45 years of age at onset (χ2 = 2.41, d.f. = 1, p = 0.12). The highest risk was observed in 1996, declining thereafter. Among military personnel who were not deployed to the Gulf region, the level of risk remained fairly constant during the 11-year period. Conclusions: The excess risk of ALS among 1991 Gulf War veterans was limited to the decade following the war.
Histological Features of Symptomatic Carotid Plaques in Patients with Impaired Glucose Tolerance and Diabetes (Oxford Plaque Study)
Authors: Redgrave J.N. , Lovett J.K. , Syed A.B. , Rothwell P.M.
Published: June 2008

Background: Diabetes is associated with an increased risk of incident stroke and both early and late recurrent stroke after transient ischaemic attack. Some small studies have suggested that atherosclerotic plaques from diabetics have a higher prevalence of unstable features than plaques from non-diabetics but results have been inconsistent. Method: We made detailed histological assessments of 526 plaques from consecutive patients undergoing carotid endarterectomy for recently symptomatic stenosis and related these to the presence of diabetes and impaired glucose tolerance (IGT). Results: 53 (10.1%) patients had diabetes, 26 (5%) had IGT and 447 (84.9%) had normal glucose tolerance (NGT). The overall prevalence of unstable plaque features was similar across these groups. However, whereas plaques removed >60 days after last symptoms in patients with NGT had less surface thrombus (OR = 0.61, 95% CI = 0.40–0.92, p = 0.02), fewer plaque macrophages (OR = 0.78, 95% CI = 0.51–1.19, p < 0.001) and less marked overall instability (OR = 0.57, 95% CI = 0.35–0.88, p = 0.009) than plaques removed more acutely, these features tended to be more persistent in patients with diabetes/IGT (OR = 1.08, 95% CI = 0.42–2.77, OR = 1.16, 95% CI = 0.46–2.96 and OR = 1.51, 95% CI = 0.60–3.77, respectively). Conclusion: Overall, the prevalence of unstable histology features in recently symptomatic carotid plaques is similar in patients with diabetes, IGT and NGT. However, surface thrombus and plaque macrophages appear to persist for longer after ischaemic symptoms in plaques from patients with diabetes/IGT compared to plaques from patients with NGT. This may contribute to the increased risk of recurrent stroke that is associated with diabetes/IGT.
Lifestyle and Memory in the Elderly
Authors: Flöel Agnes , Witte A. Veronica , Lohmann Hubertus , Wersching Heike , Ringelstein E. Bernd , Berger Klaus , Knecht Stefan
Published: June 2008

Background: Healthy lifestyle has been associated with a decreased risk of developing cardiovascular disease, but its relationship with memory functions is still inconclusive. This study aims to analyze the association between a composite lifestyle index and memory performance. Methods: In this cross-sectional survey, 198 healthy individuals (aged 65–84 years) underwent tests of verbal episodic memory. A composite lifestyle index was calculated that included the following lifestyle dimensions: physical exercise, dietary habits, BMI, smoking and alcohol consumption. The healthiest behavior was defined as: a BMI <22; a diet high in fruits, vegetables, wholemeal/low-fat foods and unsaturated fatty acids; energy expenditure through physical activity >13,000 kcal/week; a history of never smoking; an alcohol consumption of 4–10 drinks per week. Results: Linear regression analysis revealed that a high lifestyle index score was associated with a better memory score (after adjusting for age, sex, education and blood pressure). The composite index had a stronger relationship with memory scores than single factors. Conclusions: This cross-sectional study revealed that a healthy lifestyle, assessed by a simple composite index, is related to better memory performance in healthy elderly individuals. Our findings point to the importance of a comprehensive modulation of lifestyle factors when finding ways to preserve memory functions in the elderly.
Usability of Cerebrospinal Fluid Biomarkers in a Tertiary Memory Clinic
Authors: Brandt Camilla , Bahl Justyna C. , Heegaard Niels H.H. , Waldemar Gunhild , Johannsen Peter
Published: June 2008

Aim: Assays for cerebrospinal fluid (CSF) levels of total tau, phospho-tau protein and β-amyloid 1–42 have been available for some years. The aim of the study was to assess the usability of these biomarkers in a mixed population of tertiary dementia referral patients in a university-based memory clinic. Methods: 147 consecutive patients with a lumbar puncture as a part of their clinical workup were studied. A retrospective diagnosis was established based on consensus criteria without the knowledge of the CSF results. Results: When diagnosing Alzheimer’s disease (AD) compared to other diagnoses, the sensitivity of a single abnormal value was between 33 and 66%. The specificity was high except when discriminating AD from amnestic mild cognitive impairment. Two or more abnormal markers further increased the specificity and decreased the sensitivity. Conclusion: In a tertiary setting, abnormal CSF biomarker results may be of a diagnostic value – whereas normal results do not exclude neurodegenerative disease.
Acute Kidney Injury in the Diabetic Rat: Studies in the Isolated Perfused and Intact Kidney
Authors: Rosenberger Christian , Khamaisi Mogher , Goldfarb Marina , Shina Ahuva , Shilo Vitali , Zilbertrest Fanni , Rosen Seymour , Heyman Samuel N.
Published: June 2008

Background/Aim: Diabetes leads to chronic renal hypoxia and cellular hypoxia response (mediated by hypoxia-inducible factors) and predisposes to acute kidney injury. We studied the impact of acute and chronic hypoxic stress on the development of acute kidney injury in the diabetic rat kidney. Methods: Control (CTR) and streptozotocin (STZ)-diabetic rats were studied following acute medullary hypoxic stress, induced by combinations of radiocontrast and inhibitors of cyclooxygenase and NO synthase. In addition, STZ and CTR kidneys were compared following ex vivo perfusion with oxygenated cell-free medium. Results: The extents of medullary acute tubular injury and renal dysfunction were largely comparable in CTR and STZ-diabetic kidneys in vivo. By contrast, functional deterioration and outer medullary injury were markedly enhanced in STZ kidneys perfused ex vivo. A peculiar collecting duct injury pattern, with cell swelling and detachment, noted in intact STZ kidneys, prominently intensified following isolated perfusion. Conclusions: The diabetic kidney is remarkably resistant to acute hypoxic injury in vivo, possibly due to chronic hypoxia adaptation. Thus, though diabetes predisposes to acute kidney injury in various clinical settings, reduced kidney function does not necessarily imply a greater extent of true tubular damage. The collecting duct injury pattern is an as yet unrecognized feature of early experimental diabetes.
Clinical Utility of Malnutrition-Inflammation Score in Maintenance Hemodialysis Patients: Focus on Identifying the Best Cut-Off Point
Authors: Ho Li-chun , Wang His-Hao , Peng Yu-Sen , Chiang Chih-Kang , Huang Jeng-Wen , Hung Kuan-Yu , Hu Fu-Chang , Wu Kwan-Dun
Published: June 2008

Background: Malnutrition-inflammation score (MIS) is a comprehensive and quantitative system to assess malnutrition-inflammation complex syndrome, and a strong correlation between MIS and morbidity/mortality in maintenance hemodialysis (MHD) patients had been demonstrated. However, there is no cut-off value of MIS to categorize patients into high risk or low risk patients. Methods: A total of 257 chronic stable and ambulatory adult MHD patients from Far Eastern Memorial Hospital were enrolled for the study. The MIS of each patient was recorded at the initiation of study and the study population was followed up as a 12-month prospective cohort to evaluate mortality as the primary outcome. Results: Twelve patients died in the 12-month observational period. Both multiple logistic regression analyses and Cox proportional hazards model denoted MIS, alkaline phosphatase, transferrin saturation, ferritin, and total iron binding capacity as significant predictors of 1-year mortality. The conditional effect plot of MIS on 1-year mortality revealed that when fixing the alkaline phosphatase, transferrin saturation, ferritin, and total iron binding capacity at a mean value, the probability of death for an MHD patient whose MIS was 3, 4, and 5 is 10, 40, and 80%, respectively. Conclusions: Our study shows that MHD patients with MIS score of more than 4–5 had a significant risk of 1-year mortality. Additional risk factors associated with short-term mortality besides malnutrition-inflammation complex syndrome were anemia and renal osteodystrophy. This study proves that MIS is a useful tool to risk-stratify Asian MHD patients and to identify those at risk of short-term death. Nutritional interventions that can improve the MIS may also improve survival, but this hypothesis needs to be verified in interventional studies.
Heparan Sulfate in Perlecan Promotes Mouse Atherosclerosis
Authors: Tran-Lundmark Karin , Tran Phan-Kiet , Paulsson-Berne Gabrielle , Fridén Vincent , Soininen Raija , Tryggvason Karl , Wight Thomas N. , Kinsella Michael G. , Borén Jan , Hedin Ulf
Published: June 2008

Heparan sulfate (HS) has been proposed to be antiatherogenic through inhibition of lipoprotein retention, inflammation, and smooth muscle cell proliferation. Perlecan is the predominant HS proteoglycan in the artery wall. Here, we investigated the role of perlecan HS chains using apoE null (ApoE0) mice that were cross-bred with mice expressing HS-deficient perlecan (
Hspg2
Δ3/Δ3
). Morphometry of cross-sections from aortic roots and en face preparations of whole aortas revealed a significant decrease in lesion formation in ApoE0/
Hspg2
Δ3/Δ3
mice at both 15 and 33 weeks. In vitro, binding of labeled mouse triglyceride-rich lipoproteins and human LDL to total extracellular matrix, as well as to purified proteoglycans, prepared from ApoE0/
Hspg2
Δ3/Δ3
smooth muscle cells was reduced. In vivo, at 20 minutes influx of human
125
I-LDL or mouse triglyceride-rich lipoproteins into the aortic wall was increased in ApoE0/
Hspg2
Δ3/Δ3
mice compared to ApoE0 mice. However, at 72 hours accumulation of
125
I-LDL was similar in ApoE0/
Hspg2
Δ3/Δ3
and ApoE0 mice. Immunohistochemistry of lesions from ApoE0/
Hspg2
Δ3/Δ3
mice showed decreased staining for apoB and increased smooth muscle α-actin content, whereas accumulation of CD68-positive inflammatory cells was unchanged. We conclude that the perlecan HS chains are proatherogenic in mice, possibly through increased lipoprotein retention, altered vascular permeability, or other mechanisms. The ability of HS to inhibit smooth muscle cell growth may also influence development as well as instability of lesions.
Etiologic Diagnosis of Ischemic Stroke Subtypes With Plasma Biomarkers
Authors: Montaner Joan , Perea-Gainza Mila , Delgado Pilar , Ribó Marc , Chacón Pilar , Rosell Anna , Quintana Manolo , Palacios Mauricio E. , Molina Carlos A. , Alvarez-Sabín José
Published: June 2008

Background and Purpose—

Because there is no biologic marker offering precise information about stroke etiology, many patients receive a diagnosis of undetermined stroke even after all available diagnostic tests are done, precluding correct treatment.

Methods—

To examine the diagnostic value of a panel of biochemical markers to differentiate stroke etiologies, consecutive acute stroke patients were prospectively evaluated. Brain computed tomography, ultrasonography, cardiac evaluations, and other tests were done to identify an etiologic diagnosis according to TOAST classification. Blood samples were drawn on Emergency Department arrival (<24 hours) to test selected biomarkers: C-reactive protein, D-dimer, soluble receptor for advanced glycation end products, matrix metalloproteinase-9, S-100b, brain natriuretic peptide (BNP), neurotrophin-3, caspase-3, chimerin, and secretagogin (assayed by ELISA).

Results—

Of 707 ischemic stroke patients included, 36.6% were cardioembolic, 21.4% atherothrombotic, 18.1% lacunar, and 23.9% of undetermined origin. High levels of BNP, soluble receptor for advanced glycation end products, and D-dimer (
P
<0.0001) were observed in patients with cardioembolic stroke. Independent predictors (odds ratios with CIs are given) of cardioembolic stroke were as follows: atrial fibrillation 15.3 (8.4–27.7,
P
<0.001); other embolic cardiopathies 14.7 (4.7–46,
P
<0.001); total anterior circulation infarction 4 (2.3–6.8,
P
<0.001); BNP >76 pg/mL 2.3 (1.4–3.7,
P
=0.001); and D-dimer >0.96 μg/mL 2.2 (1.4–3.7,
P
=0.001). Even among patients with transient symptoms (n=155), a high BNP level identified cardioembolic etiology (6.7, 2.4–18.9;
P
<0.001). A model combining clinical and biochemical data had a sensitivity of 66.5% and a specificity of 91.3% for predicting cardioembolism.

Conclusions—

Using a combination of biomarkers may be a feasible strategy to improve the diagnosis of cardioembolic stroke in the acute phase, thus rapidly guiding other diagnostic tests and accelerating the start of optimal secondary prevention.
Hemostatic and Inflammatory Risk Factors for Intracerebral Hemorrhage in a Pooled Cohort
Authors: Sturgeon Jared D. , Folsom Aaron R. , Longstreth W.T. , Shahar Eyal , Rosamond Wayne D. , Cushman Mary
Published: June 2008

Background and Purpose—

The purpose of this study was to identify novel risk factors for intracerebral hemorrhagic stroke (ICH).

Methods—

Risk factors were assessed at baseline in a pooled cohort of the Atherosclerosis Risk in Communities Study (ARIC) and the Cardiovascular Health Study (CHS) involving 21 680 adults aged 45 or over. Over 263 489 person-years of follow-up, we identified 135 incident ICH events.

Results—

In multivariable models, for each SD higher baseline level of fibrinogen, the relative rate of incident ICH increased 35% (95% CI, 17% to 55%). Fibrinogen was more strongly related to ICH in ARIC than in CHS. In multivariable models, those with von Willebrand factor levels above the median were 1.72 (95% CI, 0.97 to 3.03) times more likely to have an incident ICH as those below the median. Factor VIII was significantly positively related to ICH in ARIC (relative rate per standard deviation of 1.31; 95% CI, 1.07 to 1.62), but not in CHS. There was no relation in multivariable models between lipoprotein (a), Factor VII, white blood cell count, or C-reactive protein and ICH.

Conclusions—

Greater plasma fibrinogen and, to some degree, von Willebrand factor were associated with increased rates of ICH in these prospective studies, whereas Factor VIII was related to ICH in younger ARIC study participants only.
Dopamine D1-Like Receptors Depress Excitatory Synaptic Transmissions in Striatal Neurons After Transient Forebrain Ischemia
Authors: Zhang Yuchun , Deng Ping , Ruan Yiwen , Xu Zao C.
Published: June 2008

Background and Purpose—Spiny neurons in the neostriatum are highly vulnerable to ischemia. Despite an enormous body of research suggesting that dopamine is involved in ischemia-induced neuronal loss in the striatum, it remains unclear how dopamine interacts with the glutamatergic excitotoxicity that is widely accepted as a major cause of ischemic cell death. Our study was designed to investigate the effects of dopamine D1 receptor (D1R) activation on excitatory neurotransmission in postischemic striatal neurons.

Methods—We used the 4-vessel occlusion ischemia model and brain slice preparations. Whole-cell voltage-clamp recording was performed on striatal neurons to measure excitatory postsynaptic currents (EPSCs). Systemic administration of a D1R agonist after ischemia and hematoxylin/eosin staining were performed to evaluate the effects of D1R activation on ischemia-induced neuronal degeneration in the striatum.

Results—D1R activation depressed EPSCs in postischemic striatal neurons. The depression was attributable to inhibition of presynaptic release. An activator of cAMP-dependent protein kinase A (PKA) mimicked the depressive effects of D1R activation. Bath application of a PKA inhibitor blocked the depression of EPSCs, whereas intracellular postsynaptic application of the PKA inhibitor had no effect. The D1R agonist failed to reduce EPSC amplitude in the presence of an adenosine A1 receptor antagonist. Systemic administration of a D1R agonist after ischemia significantly attenuated ischemia-induced cell death in the striatum.

Conclusions—These results indicate that D1R activation presynaptically depresses excitatory synaptic transmission in striatal neurons after ischemia through activation of PKA and adenosine A1 receptors and thus demonstrate a novel mechanism of D1R-mediated protection against ischemia.
Postural Dependency of Right to Left Shunt
Authors: Caputi Luigi , Carriero Maria R. , Parati Eugenio A. , Onorato Eustaquio , Casilli Francesco , Berti Marco , Anzola Gian Paolo
Published: June 2008

Background and Purpose—

Right to left shunt is involved in conditions in which postural changes may be pathogenically relevant. The aim of this work was to assess the frequency of posturally dependent right to left shunt.

Methods—

In 109 consecutive right to left shunt-positive subjects (male/female=40/69, age 43±12 years), we assessed with contrast-enhanced transcranial Doppler the bubble load during normal breathing and after the Valsalva maneuver in both standing and recumbent position randomizing the order of testing.

Results—

During normal breathing, the average bubble count was 11±20 in the recumbent and 26±60 in the standing position. After the Valsalva maneuver, it was 40±38 and 42±37, respectively. The increase of bubble load in standing position occurred in 42% of patients and was independent of the order of testing.

Conclusions—

The amount of permanent right to left shunt is posture-dependent in 40% of patients. Testing in the sitting position may thus be warranted in doubtful or inconclusive results obtained with the subject in the horizontal position.
Characterization of White Matter Injury in a Hypoxic-Ischemic Neonatal Rat Model by Diffusion Tensor MRI
Authors: Wang Silun , Wu Ed X. , Tam Chung Nga , Lau Ho-Fai , Cheung Pik-To , Khong Pek-Lan
Published: June 2008

Background and Purpose—

We evaluate white matter (WM) injury after hypoxic-ischemic (HI) insult in a neonatal rat model using diffusion tensor imaging (DTI) to determine whether λ
∥
and λ
⊥
are able to characterize type and severity of brain damage.

Methods—

Eighteen 7-day-old Sprague-Dawley rats underwent unilateral ligation of left common carotid artery followed by 50 minutes (n=9) or 90 minutes (n=9) of hypoxia at 37°C. Rats were divided into 2 groups, according to absence (group A, n=11) or presence (group B, n=7) of cystic lesions on D7 post-HI T2-weighted imaging. DTI was performed for all rats at D1 and for group A rats at D7 post-HI. Signal intensity of ipsilateral and contralateral external capsule (EC) on D1 was compared by paired
t
test, with histological correlation.

Results—

Group A rats had significantly reduced FA, elevated trace, elevated λ
⊥,
and similar λ
∥
on D1 in the ipsilateral compared to contralateral EC, whereas group B rats had significant reduction in all parameters in the ipsilateral EC. Elevated trace normalized on D7 in group A rats. Histopathologic results demonstrated reduced myelination in group A noncystic HI and severe necrosis in group B cystic HI.

Conclusions—

Increased λ
⊥
with no significant change in λ
∥
appears to characterize noncystic WM injury with reduced myelination, whereas reduction in both λ
∥
and λ
⊥
characterize severe damage with loss of structural integrity and necrosis. Combining with FA and trace, λ
∥
and λ
⊥
provide additional information which reflects type and severity of HI injury.
Early Hemorrhagic Transformation of Brain Infarction: Rate, Predictive Factors, and Influence on Clinical Outcome
Authors: Paciaroni Maurizio , Agnelli Giancarlo , Corea Francesco , Ageno Walter , Alberti Andrea , Lanari Alessia , Caso Valeria , Micheli Sara , Bertolani Luca , Venti Michele , Palmerini Francesco , Biagini Sergio , Comi Giancarlo , Previdi Paolo , Silvestrelli Giorgio
Published: June 2008

Background and Purpose—

Early hemorrhagic transformation (HT) is a complication of ischemic stroke but its effect on patient outcome is unclear. The aims of this study were to assess: (1) the rate of early HT in patients admitted for ischemic stroke, (2) the correlation between early HT and functional outcome at 3 months, and (3) the risk factors for early HT.

Methods—

Consecutive patients with ischemic stroke were included in this prospective study in 4 study centers. Early HT was assessed by CT examination performed at day 5±2 after stroke onset. Study outcomes were 3-month mortality or disability. Disability was assessed using a modified Rankin score (≥3 indicating disabling stroke) by neurologists unaware of the occurrence of HT in the individual cases. Outcomes in patients with and without early HT were compared by χ
2
test. Multiple logistic regression analysis was used to identify predictors for HT.

Results—

Among 1125 consecutive patients (median age 76.00 years), 98 (8.7%) had HT, 62 (5.5%) had hemorrhagic infarction, and 36 (3.2%) parenchymal hematoma. At 3 months, 455 patients (40.7%) were disabled or died. Death or disability was seen in 33 patients with parenchymal hematoma (91.7%), in 35 patients with hemorrhagic infarction (57.4%) as compared with 387 of the 1021 patients without HT (37.9%). At logistic regression analysis, parenchymal hematoma, but not hemorrhagic infarction, was independently associated with an increased risk for death or disability (OR 15.29; 95% CI 2.35 to 99.35). At logistic regression analysis, parenchymal hematoma was predicted by large lesions (OR 12.20, 95% CI 5.58 to 26.67), stroke attributable to cardioembolism (OR 5.25; 95% CI 2.27 to 12.14) or to other causes (OR 6.77; 95% CI 1.75 to 26.18), high levels of blood glucose (OR 1.01; 95% CI 1.00 to 1.01), and thrombolytic treatment (OR 3.54, 95% CI 1.04 to 11.95).

Conclusions—

Early HT occurs in about 9% of patients. Parenchymal hematoma, seen in about 3% of patients, is associated with an adverse outcome. Parenchymal hematoma was predicted by large lesions attributable to cardioembolism or other causes, high blood glucose, and treatment with thrombolysis.
MRI-Based Separation of Congenital and Acquired Vertebrobasilar Artery Anomalies in Ischemic Stroke of the Posterior Circulation
Authors: Freund Wolfgang , Kassubek Jan , Aschoff Andrik J. , Huber Roman
Published: June 2008

Background and Purpose—

Stroke MRI protocols provide useful information about underlying vessel pathologies in the anterior circulation by means of intracranial time-of-flight angiography. However, these protocols mostly fail in the posterior circulation to differentiate between congenital variants and secondary thrombosis. Therefore, a high-resolution anatomic True Fast Imaging in Steady State Precession sequence, added to a commonly used stroke imaging protocol, was evaluated.

Methods—

MRIs of all emergency admissions to the stroke unit over 2 months were analyzed. Variations in the posterior circulation as displayed by time-of-flight and by the True Fast Imaging in Steady State Precession sequence, respectively, were graded by 2 readers blinded to the diagnosis.

Results—

In the time-of-flight angiography, 50% of patients presented with distinctive vertebrobasilar alterations. Half of these were judged as high-grade anomalies, of which the True Fast Imaging in Steady State Precession sequence identified 25% as hypoplasia. In 40% of all patients with posterior ischemia, the True Fast Imaging in Steady State Precession sequence confirmed an acquired occlusion of the vertebrobasilar arteries.

Conclusions—

The addition of an anatomic (True Fast Imaging in Steady State Precession) to a functional sequence (time-of-flight) in stroke MRI protocols enables the differentiation between artery occlusions and hypoplastic variants of the vertebral arteries.
Rural Ties of Urban Migrants in Thailand
Authors: Tirasawat Penporn , Goldstein Alice , Goldstein Sidney
Published: June 2008

In Thailand, as in other less developed countries, migration is assuming an increasingly important role in the dynamics of population growth and distribution. Concurrent with the recognition of migration's importance has been a growing awareness of the complexity of the process. A host of factors, including characteristics pertaining to the individual as well as to the places of origin and destination, determine who moves, when the move occurs, and to where. For example, research on Thailand (S. Goldstein, Prachuabmoh, and A. Goldstein, 1974) has shown that there are important occupational and educational differentials between the migrants on the one hand and the non-migrants at both origin and destination on the other. In general, migrants tend to be more educated than the rural population they leave behind; yet those moving to Bangkok are on the average less educated than the capital's natives. At the same time, migrants are disproportionally concentrated in service work, especially in Bangkok, where they are also particularly underrepresented among white collar workers. Moreover, migration is seldom a simple, one-step process; a substantial proportion of persons move several times. For some, these multiple moves involve a stepping-stone process from small to larger places; for others, the moves may be circular in character, involving return moves to place of origin.
Legislating a Solution to Animal Shelter Euthanasia: A Case Study of California's Controversial SB 1785
Authors: Balcom Sarah A.
Published: June 2008

On September 22, 1998, California Governor Pete Wilson signed Senate Bill 1785 into law, dramatically affecting the entire Califomia animal sheltering community. Dubbed the "Hayden law" by the animal protection community after the bill's sponsor, it represents the state of Califomia's attempt to legislate a solution to both the companion animal overpopulation problem and the friction between the agencies trying to end it.The persistence of the bill's primary supporters, a Los Angeles veterinarian and a UCLA law school professor and the overall lack of opposition to it helped SB 1785 sail through the California legislature. Because of the scope of the bill and the immense cost of implementation, its passage shocked many in the sheltering community.This case study highlights the consequences of legislation that was crafted based on worse case scenarios and over which there was little collaborative effort. It concludes with suggestions that might be useful to other states contemplating similar such legislation.
Beyond Anecdotes: An Empirical Study of "Anthropomorphism"
Authors: Fidler Margaret , Costall Alan , Morris Paul
Published: June 2008

The status of "anthropomorphic" descriptions of animals in terms of intentions and emotions has been generally regarded as a prescriptive methodological concern. In contrast, in the study of human social psychology the nature of psychological descriptions of other people has been approached as a substantive empirical issue. Following this lead, the present study investigated the nature of people's descriptions of short videotaped episodes of animal behavior. The descriptions obtained were predominantly anthropomorphic and structured according to a limited set of "event units" whose psychological meaning was highly consistent across the observers. In common with many social psychologists we conclude that consistency of anthropomorphic description suggests that meaning is specified within the structure of behavior.
Religion in the Making? Animality, Savagery, and Civilization in the Work of A. N. Whitehead
Authors: Palmerl Clare
Published: June 2008

Constructions of the animal and animality are often pivotal to religious discourses. Such constructions create the possibility of identifying and valuing what is "human" as opposed to the "animal" and also of distinguishing human beliefs and behaviors that can be characterized (and often disparaged) as being animal from those that are "truly human." Some discourses also employ the concept of savagery as a bridge between the human and the animal, where the form of humanity but not its ideal beliefs and practices can be displayed. This paper explores the work of the influential scientist, philosopher, and theologian A. N. Whitehead in this context. His ideas of what constitutes "the animal." the "primitive" and the "civilized" are laid out explicitly in his now little-used history of religions text, Religion in the Making.This paper explores these ideas in this history and then considers how the same ideas permeate his currently more popular philosophical and theological writing Process and Reolity. Drawing on some work in post-colonial theory the paper offers a critique of this understanding of animality, savagery, and civilization and suggests that using Whitehead to underpin modern theological work requires considerable caution.
The Role of Irrigation Expansion in Past and Future Temperature Trends
Authors: Lobell David B. , Bonfils Céline , Faurès Jean-Marc
Published: June 2008

Expansion of irrigated land can cause local cooling of daytime temperatures by up to several degrees Celsius. Here the authors compare the expected cooling associated with rates of irrigation expansion in developing countries for historical (1961–2000) and future (2000–30) periods with climate model predictions of temperature changes from other forcings, most notably increased atmospheric greenhouse gas levels, over the same periods. Indirect effects of irrigation on climate, via methane production in paddy rice systems, were not considered. In regions of rapid irrigation growth over the past 40 yr, such as northwestern India and northeastern China, irrigation’s expected cooling effects have been similar in magnitude to climate model predictions of warming from greenhouse gases. A masking effect of irrigation can therefore explain the lack of significant increases in observed growing season maximum temperatures in these regions and the apparent discrepancy between observations and climate model simulations. Projections of irrigation for 2000–30 indicate a slowing of expansion rates, and therefore cooling from irrigation expansion over this time period will very likely be smaller than in recent decades. At the same time, warming from greenhouse gases will likely accelerate, and irrigation will play a relatively smaller role in agricultural climate trends. In many irrigated regions, therefore, temperature projections from climate models, which generally ignore irrigation, may be more accurate in predicting future temperature trends than their performance in reproducing past observed trends in irrigated regions would suggest.
Economic Value of Seasonal Climate Forecasts for Agriculture: Review of Ex-Ante Assessments and Recommendations for Future Research
Authors: Meza Francisco J. , Hansen James W. , Osgood Daniel
Published: June 2008

Advanced information in the form of seasonal climate forecasts has the potential to improve farmers’ decision making, leading to increases in farm profits. Interdisciplinary initiatives seeking to understand and exploit the potential benefits of seasonal forecasts for agriculture have produced a number of quantitative ex-ante assessments of the economic value of seasonal climate forecasts. The realism, robustness, and credibility of such assessments become increasingly important as efforts shift from basic research toward applied research and implementation. This paper surveys published evidence about the economic value of seasonal climate forecasts for agriculture, characterizing the agricultural systems, approaches followed, and scales of analysis. The climate forecast valuation literature has contributed insights into the influence of forecast characteristics, risk attitudes, insurance, policy, and the scale of adoption on the value of forecasts. Key innovations in the more recent literature include explicit treatment of the uncertainty of forecast value estimates, incorporation of elicited management responses into bioeconomic modeling, and treatment of environmental impacts, in addition to financial outcomes of forecast response. It is argued that the picture of the value of seasonal forecasts for agriculture is still incomplete and often biased, in part because of significant gaps in published valuation research. Key gaps include sampling of a narrow range of farming systems and locations, incorporation of an overly restricted set of potential management responses, failure to consider forecast responses that could lead to “regime shifts,” and failure to incorporate state-of-the-art developments in seasonal forecasting. This paper concludes with six recommendations to enhance the realism, robustness, and credibility of ex-ante valuation of seasonal climate forecasts.
Short-Period Modulations in Aerosol Optical Depths over the Central Himalayas: Role of Mesoscale Processes
Authors: Dumka U. C. , Moorthy K. Krishna , Satheesh S. K. , Sagar Ram , Pant P.
Published: June 2008

Multiyear measurements of spectral aerosol optical depths (AODs) were made at Manora Peak in the central Himalaya Range (29°22′N, 79°27′E, ∼1950 m above mean sea level), using a 10-channel multiwavelength solar radiometer for 605 days during January 2002–December 2004. The AODs at 0.5 μm were very low (≤0.1) in winter and increased steeply to reach high values (∼0.5) in summer. It was observed that monthly mean AODs vary significantly (by more than a factor of 6) from January to June. Strong short-period fluctuations (within a daytime) were observed in the AODs. Further investigations of this aspect have revealed that boundary layer dynamics plays a key role in transporting aerosols from the polluted valley region to higher altitudes, causing large contrast in AODs between forenoon and afternoon. The seasonal variations in AODs, while examined in conjunction with synoptic-scale wind fields, have revealed that the transport of dust aerosols from arid regions to the valley regions adjacent to the observational site and their subsequent transport upward by boundary layer dynamics are responsible for the summer increases.