bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel data stream pattern mining report on the StreamKDD'10 workshop
Authors: Dunham Margaret H. , Hahsler Michael , Spiliopoulou Myra
Published: April 2011

This report summarizes the First International Workshop on Novel Data Stream Pattern Mining held at the 16th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, on July 25 2010 in Washington, DC.
Activity recognition using cell phone accelerometers
Authors: Kwapisz Jennifer R. , Weiss Gary M. , Moore Samuel A.
Published: April 2011

Mobile devices are becoming increasingly sophisticated and the latest generation of smart cell phones now incorporates many diverse and powerful sensors. These sensors include GPS sensors, vision sensors (i.e., cameras), audio sensors (i.e., microphones), light sensors, temperature sensors, direction sensors (i.e., magnetic compasses), and acceleration sensors (i.e., accelerometers). The availability of these sensors in mass-marketed communication devices creates exciting new opportunities for data mining and data mining applications. In this paper we describe and evaluate a system that uses phone-based accelerometers to perform activity recognition, a task which involves identifying the physical activity a user is performing. To implement our system we collected labeled accelerometer data from twenty-nine users as they performed daily activities such as walking, jogging, climbing stairs, sitting, and standing, and then aggregated this time series data into examples that summarize the user activity over 10- second intervals. We then used the resulting training data to induce a predictive model for activity recognition. This work is significant because the activity recognition model permits us to gain useful knowledge about the habits of millions of users passively---just by having them carry cell phones in their pockets. Our work has a wide range of applications, including automatic customization of the mobile device's behavior based upon a user's activity (e.g., sending calls directly to voicemail if a user is jogging) and generating a daily/weekly activity profile to determine if a user (perhaps an obese child) is performing a healthy amount of exercise.
Learning 2.0: How digital networks are changing the rules
Authors: Sisley Mélanie L.
Published: April 2011

How can we harness the power of digital networks and Web 2.0 tools to thrive as learners in this new age of connectivity and immediacy? Not only is learning evolving, but our brains are as well. As the lines that separate free time from work time continue to blur, our consumption of technology may be affecting attention span. And if our brains are starting to function differently, what does this mean for learning?
Academic Honesty in the Online Environment
Authors: Everson Michelle
Published: April 2011

There seems to be a common sentiment that online courses open up the door for students to become more mischievous and dishonest than they ever would dare in a more traditional classroom setting, but why is that the case?
Critical roles for the COOH terminus of the Cu-ATPase ATP7B in protein stability, trans-Golgi network retention, copper sensing, and retrograde trafficking
Authors: Braiterman L. , Nyasae L. , Leves F. , Hubbard A. L.
Published: April 2011

ATP7A and ATP7B are copper-transporting P-type ATPases that are essential to eukaryotic copper homeostasis and must traffic between intracellular compartments to carry out their functions. Previously, we identified a nine-amino acid sequence (F37–E45) in the NH2terminus of ATP7B that is required to retain the protein in the Golgi when copper levels are low and target it apically in polarized hepatic cells when copper levels rise. To understand further the mechanisms regulating the intracellular dynamics of ATP7B, using multiple functional assays, we characterized the protein phenotypes of 10 engineered and Wilson disease-associated mutations in the ATP7B COOH terminus in polarized hepatic cells and fibroblasts. We also examined the behavior of a chimera between ATP7B and ATP7A. Our results clearly demonstrate the importance of the COOH terminus of ATP7B in the protein's copper-responsive apical trafficking. L1373 at the end of transmembrane domain 8 is required for protein stability and Golgi retention in low copper, the trileucine motif (L1454–L1456) is required for retrograde trafficking, and the COOH terminus of ATP7B exhibits a higher sensitivity to copper than does ATP7A. Importantly, our results demonstrating that four Wilson disease-associated missense mutations behaved in a wild-type manner in all our assays, together with current information in the literature, raise the possibility that several may not be disease-causing mutations.
Hepatic steatosis, inflammation, and ER stress in mice maintained long term on a very low-carbohydrate ketogenic diet
Authors: Garbow Joel R. , Doherty Jason M. , Schugar Rebecca C. , Travers Sarah , Weber Mary L. , Wentz Anna E. , Ezenwajiaku Nkiruka , Cotter David G. , Brunt Elizabeth M. , Crawford Peter A.
Published: April 2011

Low-carbohydrate diets are used to manage obesity, seizure disorders, and malignancies of the central nervous system. These diets create a distinctive, but incompletely defined, cellular, molecular, and integrated metabolic state. Here, we determine the systemic and hepatic effects of long-term administration of a very low-carbohydrate, low-protein, and high-fat ketogenic diet, serially comparing these effects to a high-simple-carbohydrate, high-fat Western diet and a low-fat, polysaccharide-rich control chow diet in C57BL/6J mice. Longitudinal measurement of body composition, serum metabolites, and intrahepatic fat content, using in vivo magnetic resonance spectroscopy, reveals that mice fed the ketogenic diet over 12 wk remain lean, euglycemic, and hypoinsulinemic but accumulate hepatic lipid in a temporal pattern very distinct from animals fed the Western diet. Ketogenic diet-fed mice ultimately develop systemic glucose intolerance, hepatic endoplasmic reticulum stress, steatosis, cellular injury, and macrophage accumulation, but surprisingly insulin-induced hepatic Akt phosphorylation and whole-body insulin responsiveness are not impaired. Moreover, whereas hepatic Pparg mRNA abundance is augmented by both high-fat diets, each diet confers splice variant specificity. The distinctive nutrient milieu created by long-term administration of this low-carbohydrate, low-protein ketogenic diet in mice evokes unique signatures of nonalcoholic fatty liver disease and whole-body glucose homeostasis.
Role of Fibulin-5 in Metastatic Organ Colonization
Authors: Devitt Møller Henrik , Ralfkjær Ulrik , Cremers Natascha , Frankel Mika , Troelsgaard Pedersen Rune , Klingelhöfer Jörg , Yanagisawa Hiromi , Grigorian Mariam , Guldberg Per , Sleeman Jonathan , Lukanidin Eugene , Ambartsumian Noona
Published: April 2011

The tumor microenvironment is now recognized as a major factor in determining the survival and growth of disseminated tumor cells at potential metastatic sites. Tumor cells send signals to stroma cells and stimulate them to produce factors that in turn create favorable conditions for tumor cell metastasis. Activated fibroblasts constitute an important component of the tumor-associated stroma. We have previously shown that S100A4 protein produced by stromal fibroblasts in the primary tumor stimulates metastasis formation. Here we show that activated fibroblasts also stimulate the formation of metastases independently of S100A4 expression during organ colonization. To identify genes that could potentially interfere with fibroblast-driven metastasis, we used gene expression profiling of S100A4-deficient fibroblasts treated with and without tumor cell-conditioned media. Five differentially expressed genes encoding cell surface and secreted proteins with potential metastasis-modulating activity were selected. Expression of lymphocyte antigen 6 complex (Ly6c) and matrix metalloproteinase 3 (Mmp3) was upregulated in fibroblasts in response to tumor-conditioned medium, whereas expression of cadherin-16 (Cdh16), Ccn2, and fibulin-5 (Fbln5) was downregulated. Further analysis showed that Fibulin-5 is able to suppress the metastatic colonization of lungs and liver. Additional studies suggest a mechanism in which Fibulin-5 suppresses metastasis formation by inhibiting production of matrix metalloproteinase 9 (MMP9) and reducing the invasive behavior of fibroblasts. Together our data are consistent with the notion that tumors secrete factors that downregulate expression of Fbln5 in fibroblasts at sites of metastatic colonization, in turn upregulating Mmp9 expression and stimulating metastatic organ colonization. Mol Cancer Res; 9(5); 553–63. ©2011 AACR.
Effect of Ambroxol on Pneumonia Caused by Pseudomonas aeruginosa with Biofilm Formation in an Endotracheal Intubation Rat Model
Authors: Li Fang , Wang Wenlei , Hu Linyan , Li Luquan , Yu Jialin
Published: April 2011

Background:Pseudomonas aeruginosa, especially the mucoid phenotype, is responsible for most of the morbidity and mortality in ventilator-associated pneumonia. Although ambroxol is widely used in neonatal lung problems as a mucolytic as well as an antioxidant agent, its anti-infective role is not well demonstrated by studies in vivo. Objective: To explore the effect of ambroxol on the biofilms of mucoid P. aeruginosa and on the associated lung infection using a rat model. Methods: We developed a rat model of acute lung infection by endotracheal intubation with a tube covered with mucoid P. aeruginosa biofilm. Then, we studied the effect of ambroxol on the biofilm using saline treatment as a control. Subsequently, we studied the microstructure of the biofilm, bacterial count in the tubes and lungs, pathological changes that occurred in the lungs, and the cytokine response. Results: Alteration of the microstructure of the biofilm with ambroxol treatment was demonstrated by scanning electron microscopy. The bacterial counts on the biofilm-covered tube in the ambroxol-treated group were significantly lower than those in the saline-treated group on both post-bacterial challenge days 4 and 7 (p < 0.05). The bacterial counts in lungs of the ambroxol-treated group and of the saline-treated group on post-bacterial challenge day 7 were not significantly different (p > 0.05). The pathological changes in lungs were milder with the effect of ambroxol. The cytokine responses, namely the level of IFN-γ and the ratio of IFN-γ and IL-10, were also reduced with the effect of ambroxol. Conclusion: We demonstrated that the ambroxol treatment could destroy the structure of the biofilm on the tube used for intubation and decrease the bacterial load. Further, the reduced cytokine response and milder pathological changes in lungs in an endotracheal intubation rat model indicate that ambroxol can attenuate the damage caused by biofilm-associated infection in the lung.
Randomized Controlled Trial: Impact of Glycerin Suppositories on Time to Full Feeds in Preterm Infants
Authors: Khadr Sophie N. , Ibhanesebhor Samuel E. , Rennix Connie , Fisher Hazel E. , Manjunatha Chikkanayakanahalli M. , Young David , Abara Rosemary C.
Published: April 2011

Background: Feed intolerance delays achievement of enteral feeding in preterm infants. Parenteral nutrition is associated with cholestasis and increased risk of sepsis. Glycerin suppositories have been used to promote gastrointestinal motility and feed tolerance. Objectives: To investigate whether daily glycerin suppositories (a) reduce the time to full enteral feeding in infants born at <32 weeks’ gestation, and (b) influence feed tolerance, incidence of sepsis or necrotizing enterocolitis, duration of oxygen requirement, growth or age at discharge. Methods: Design – prospective open randomized controlled trial; study population – preterm infants stratified into 2 subgroups, 24–27+6 weeks (24–27 weeks + 6 days) and 28–31+6 weeks; intervention – daily glycerin suppository for 10 days from 24 h of age, 250 mg (24–27+6 weeks subgroup) or 500 mg (two 250-mg suppositories; 28–31+6 weeks subgroup); controls – no intervention. The same feeding protocol and departmental guidelines for other aspects of neonatal intensive care were used in all subjects. Analysis was by intention to treat. Results: 54 babies were recruited (31 males), 29 randomized to receive suppositories; 48 achieved full enteral feeds. The median (range) time to full feeds was 1.6 days shorter in intervention group babies than controls, but not statistically significant: 7.4 (4.6–30.9) days versus 9.0 (4.4–13.3) days (p = 0.780; 95% confidence interval: –1.917, 2.166). No significant differences were observed in secondary outcomes. Intervention group babies passed their first stool earlier than controls (median: day 2 vs. day 4; p = 0.016). Conclusion: Regular glycerin suppositories did not reduce the time to full enteral feeds in infants born at <32 weeks’ gestation in our setting.
Effect of Obstructive Sleep Apnea on QT Dispersion: A Potential Mechanism of Sudden Cardiac Death
Authors: Voigt Louis , Haq Salman A. , Mitre Cristina A. , Lombardo Gerard , Kassotis John
Published: April 2011

Objectives: QT dispersion (QTd) measures the variability of the ventricular recovery time. QTd may identify patients at risk for ventricular arrhythmias and sudden cardiac death (SCD). The purpose of our study was to determine the effect of obstructive sleep apnea (OSA) on QTd. Methods: There were 199 patients studied: 101 patients (28 women, 73 men) with OSA diagnosed in our sleep center and 98 patients (49 women, 49 men) without OSA from the outpatient clinic, representing the control group. QT intervals (milliseconds) were measured in each of the 12 leads of a standard surface electrocardiogram during wakefulness and QTd calculated (QTmax – QTmin). QTcd, which corrects for heart rate, was also calculated. Results: Mean age and heart rate were similar in men and women with or without OSA. Control patients exhibited a significant difference (p < 0.001) in QTd between men (48 ± 19) and women (31 ± 13). Men and women with OSA had similar QTd (56 ± 35 vs. 54 ± 21) but higher QTd compared to the control group. QTcd results were similar to QTd. Conclusions: Patients with OSA and no structural heart disease have a higher QTd/QTcd compared to an overtly healthy patient population, possibly serving as a marker for an increased risk of SCD.
Are Gentamicin and/or Vancomycin Associated with Ototoxicity in the Neonate? A Retrospective Audit
Authors: Vella-Brincat Jane W.A. , Begg Evan J. , Robertshawe Barbara J. , Lynn Adrienne M. , Borrie Tracey L. , Darlow Brian A.
Published: April 2011

Background: Aminoglycoside-induced ototoxicity has been reported in neonates but its incidence is poorly defined, whereas vancomycin-induced ototoxicity has not been reported in neonates. Objective: To compare hearing test results in infants in a neonatal intensive care unit (NICU) who were or were not treated with extended interval gentamicin dosing and/or standard vancomycin dosing. Method:A database of otoacoustic emissions (OAE), over a 5-year period of NICU admissions, was combined with databases of gentamicin and vancomycin dosing to compare patients treated or not treated with these antibiotics.Results:A total of 2,347 OAE results was available. OAE failure rates were: no gentamicin and no vancomycin (noGnoV), 7% (85/1,233); gentamicin but no vancomycin (GnoV), 4% (42/949); vancomycin but no gentamicin (VnoG), 22% (9/41) and gentamicin and vancomycin (GandV), 14% (17/124). Compared to noGnoV there was a decreased risk of OAE failure in GnoV (p = 0.022, OR 0.64, 95% CI 0.44–0.94) and an increased risk in VnoG (p = 0.003, OR 3.46, 95% CI 1.54–7.75) and GandV, (p = 0.006, OR 2.20, 95% CI 1.26–3.83). Conclusions:Gentamicin, as used and evaluated in this audit, showed no evidence of an increased risk of ototoxicity; what was observed was a statistically significant decrease in OAE failure rate. Vancomycin, by contrast, was associated with ototoxicity.
Programming of Adult Cardiovascular Disease following Exposure to Late-Gestation Hyperglycemia
Authors: Agoudemos Melissa , Reinking Benjamin E. , Koppenhafer Stacia L. , Segar Jeffrey L. , Scholz Thomas D.
Published: April 2011

Background: In utero exposure to hyperglycemia is becoming increasingly prevalent as the number of women entering pregnancy with type II diabetes, or developing gestational diabetes, increases. Both animal studies and epidemiologic investigations have found cardiovascular abnormalities in adult offspring of hyperglycemic mothers (OHM). Objective: We hypothesized that adult OHM would have abnormal cardiac function in vivo and increased susceptibility to ischemia. Methods: Pregnant rats were made diabetic on day 12 of gestation. Serum glucose was monitored twice daily and insulin provided to maintain serum glucose at 200–400 mg/dl. Offspring were fostered to normal mothers after birth. Adult OHM were studied at 8–10 months of age with echocardiography to assess in vivo cardiac function and isolated hearts to determine the response to ischemia. Results: Echocardiography found significant diastolic dysfunction in male OHM compared to male controls. In isolated hearts, baseline cardiac function and left ventricular compliance was significantly diminished in male OHM compared to controls. Ischemia caused a significant decline in heart function in controls and female OHM, while function in male OHM remained unchanged. Conclusions: Adult male OHM demonstrate programmed cardiac dysfunction. Given the growing number of pregnancies complicated by hyperglycemia, additional assessment of cardiac function of adults born to diabetic mothers may be warranted.
Longitudinal Assessment of Cognitive Function by Clock Drawing in Older Adults
Authors: Paganini-Hill Annlia , Clark Linda J.
Published: April 2011

Aims: To test the hypotheses that performance on a clock-drawing task (CDT) diminishes over time and that poor performance is associated with development of dementia and reduced survival. Methods: Participants in the population-based Leisure World Cohort Study were asked to complete a CDT in follow-up questionnaires mailed in 1992 and 1998. Dementia status was determined using in-person evaluations, follow-up questionnaires, hospital data, and death certificates. Results: Of the 4,842 cohort members (mean age 80 years) who completed the CDT in 1992, 1,521 also completed it in 1998. Although performance in the CDT diminished over time in only a proportion of the cohort, the mean total score and the percentage of subjects with correctly drawn clocks decreased with each successive 5-year age group (p = 0.0001) and over time. Mean scores were lower in non-demented subjects later identified as demented compared with those who remained free of dementia. A low CDT score in 1992 was associated with a 28% increased risk of dementia and 13% reduced survival. Conclusion: A CDT may help predict cognitive decline and future disability in the elderly. Identification of high-risk individuals using a CDT may lead to earlier diagnosis and treatment and improved patient management.
Adiponectin Induces Vascular Smooth Muscle Cell Differentiation via Repression of Mammalian Target of Rapamycin Complex 1 and FoxO4
Authors: Ding Min , Xie Yi , Wagner Robert J. , Jin Yu , Carrao Ana Catarina , Liu Lucinda S. , Guzman Anthony K. , Powell Richard J. , Hwa John , Rzucidlo Eva M. , Martin Kathleen A.
Published: April 2011

Objective—

The adipocyte-secreted hormone adiponectin exerts important cardioprotective and antidiabetic effects. Little is known about its effect on vascular smooth muscle cells (VSMC), key cells in restenosis, hypertension, and atherosclerosis.

Methods and Results—

Using human coronary artery VSMC, we found that recombinant adiponectin in the high-molecular-weight or trimeric forms but not the globular form induced VSMC differentiation through a mechanism similar to the classic feedback signaling used by rapamycin, a drug known to effectively inhibit restenosis on drug-eluting stents. Using a combination of pharmacological agents, small interfering RNA, and overexpression approaches, we demonstrated that adiponectin activated 5′-AMP-activated protein kinase α2 isoform, leading to inhibition of mammalian target of rapamycin complex 1 and S6K1. This in turn stabilized insulin receptor substrate-1, driving Akt2-mediated inhibition of FoxO4 and subsequent contractile protein induction. Although adiponectin and rapamycin have similarly beneficial effects on VSMC phenotype in both cell and organ culture, a direct comparison of the effects of rapamycin versus adiponectin on endothelial cells revealed distinct differences: rapamycin inhibited Akt phosphorylation, whereas adiponectin maintained it. Importantly, Akt activity preserves endothelial function.

Conclusion—

Adiponectin promotes VSMC differentiation and preserves endothelial cell Akt signaling, suggesting that targeting the adiponectin pathway may have advantages over rapamycin in developing new drug-eluting stent therapeutics.
Hypoxia Inducible Factor–Dependent Regulation of Angiogenesis by Nitro–Fatty Acids
Authors: Rudnicki Martina , Faine Luciane A. , Dehne Nathalie , Namgaladze Dmitry , Ferderbar Simone , Weinlich Ricardo , Amarante-Mendes Gustavo P. , Yan Chao Y.I. , Krieger José E. , Brüne Bernhard , Abdalla Dulcineia S.P.
Published: April 2011

Objective—

Nitro-fatty acids (NO
2
-FAs) are emerging as a new class of cell signaling mediators. Because NO
2
-FAs are found in the vascular compartment and their impact on vascularization remains unknown, we aimed to investigate the role of NO
2
-FAs in angiogenesis.

Methods and Results—

The effects of nitrolinoleic acid and nitrooleic acid were evaluated on migration of endothelial cell (EC) in vitro, EC sprouting ex vivo, and angiogenesis in the chorioallantoic membrane assay in vivo. At 10 μmol/L, both NO
2
-FAs induced EC migration and the formation of sprouts and promoted angiogenesis in vivo in an NO-dependent manner. In addition, NO
2
-FAs increased intracellular NO concentration, upregulated protein expression of the hypoxia inducible factor-1α (HIF-1α) transcription factor by an NO-mediated mechanism, and induced expression of HIF-1α target genes, such as vascular endothelial growth factor, glucose transporter-1, and adrenomedullin. Compared with typical NO donors such as spermine-NONOate and deta-NONOate, NO
2
-FAs were slightly less potent inducers of EC migration and HIF-1α expression. Short hairpin RNA–mediated knockdown of HIF-1α attenuated the induction of vascular endothelial growth factor mRNA expression and EC migration stimulated by NO
2
-FAs.

Conclusion—

Our data disclose a novel physiological role for NO
2
-FAs, indicating that these compounds induce angiogenesis in an NO-dependent mechanism via activation of HIF-1α.
Hypoxia Stimulates Low-Density Lipoprotein Receptor–Related Protein-1 Expression Through Hypoxia-Inducible Factor-1α in Human Vascular Smooth Muscle Cells
Authors: Castellano Jose , Aledo Rosa , Sendra Judith , Costales Paula , Juan-Babot Oriol , Badimon Lina , Llorente-Cortés Vicenta
Published: April 2011

Objective—

Hypoxia is considered a key factor in the progression of atherosclerotic lesions. Low-density lipoprotein receptor–related protein (LRP1) plays a pivotal role in the vasculature. The aim of this study was to investigate the effect of hypoxia on LRP1 expression and function in vascular smooth muscle cells (VSMC) and the role of hypoxia-inducible factor-α (HIF-1α).

Methods and Results—

Real-time polymerase chain reaction and Western blot analysis demonstrated that hypoxia (1% O
2
) time-dependently induced LRP1 mRNA (maximum levels at 1 to 2 hours) and protein expression (maximum levels at 12 to 24 hours). The delayed hypoxic upregulation of LRP1 protein versus mRNA may be explained by the long half-life of LRP1 protein. Luciferase assays demonstrated that hypoxia and HIF-1α overaccumulation induced LRP1 promoter activity and that 2 consensus hypoxia response element sites located at −1072/−1069 and −695/−692 participate in the induction. Chromatin immunoprecipitation showed the in vivo binding of HIF-1α to LRP1 promoter in hypoxic VSMC. Hypoxia effects on LRP1 protein expression were functionally translated into an increased cholesteryl ester (CE) accumulation from aggregated low-density lipoprotein (agLDL) uptake. The blockade of HIF-1α expression inhibited the upregulatory effect of hypoxia on LRP1 expression and agLDL-derived intracellular CE overaccumulation, suggesting that both LRP1 overexpression and CE overaccumulation in hypoxic vascular cells are dependent on HIF-1α. Immunohistochemical analysis showed the colocalization of LRP1 and HIF-1α in vascular cells of human advanced atherosclerotic plaques.

Conclusion—

Hypoxia upregulates LRP1 expression and agLDL-derived intracellular CE accumulation in human VSMC through HIF-1α induction.
Recurrent Hypoglycemia Exacerbates Cerebral Ischemic Damage in Streptozotocin-Induced Diabetic Rats
Authors: Dave Kunjan R. , Tamariz John , Desai Kushal M. , Brand Frank J. , Liu Annie , Saul Isabel , Bhattacharya Sanjoy K. , Pileggi Antonello
Published: April 2011

Background and Purpose—

Stroke and heart disease are the most serious complications of diabetes accounting for >65% of mortality among diabetics. Although intensive insulin therapy has significantly improved the prognosis of diabetes and its complications, it is associated with an elevated risk of recurrent hypoglycemia (RH). We tested the hypothesis that RH exacerbates cerebral ischemic damage in a rodent model of diabetes.

Method—

We determined the extent of neuronal death in CA1 hippocampus after global cerebral ischemia in control and streptozotocin-induced diabetic rats. Diabetic animals included an insulin-treated streptozotocin-diabetic (ITD) group and a group of ITD rats exposed also to 10 episodes of hypoglycemia (ITD+recurrent hypoglycemia: RH). Hypoglycemia (55 to 65 mg/dL blood glucose) was induced twice daily for 5 consecutive days.

Results—

As expected, uncontrolled diabetes (streptozotocin-diabetes, untreated animals) resulted in a 70% increase in ischemic damage as compared with the control group. Insulin treatment was able to lower ischemic damage by 64% as compared with the diabetic group. However, ITD+RH rats had 44% more damage when compared with the ITD group. We also observed that free radical release from mitochondria is increased in ITD+RH rats.

Conclusions—

This is the first report on the impact of RH in exacerbating cerebral ischemic damage in diabetic animals. Our results suggest that increased free radical release from mitochondria may be responsible for observed increased ischemic damage in ITD+RH rats. RH thus may be an unexplored but important factor responsible for increased ischemic damage in diabetes.
Prevalence and Calcification of Intracranial Arterial Stenotic Lesions as Assessed With Multidetector Computed Tomography Angiography
Authors: Homburg Philip J. , Plas Gerben J.J. , Rozie Sietske , van der Lugt Aad , Dippel Diederik W.J.
Published: April 2011

Background and Purpose—

Intracranial arterial stenosis (ICAS) in patients with recent ischemic stroke is associated with a high risk of recurrent stroke. More insight into the pathophysiology of ICAS could help identify patients at high risk requiring more aggressive secondary prevention. We evaluated the prevalence, distribution, calcification, and the risk factors predisposing ICAS in a European stroke population.

Methods—

Consecutive patients with a transient ischemic attack or ischemic stroke (n=786) were evaluated for the presence and distribution of ICAS (≥30% luminal narrowing) by CT angiography. ICAS were categorized as symptomatic or asymptomatic, and the presence of calcification was assessed. The association of traditional cerebrovascular risk factors and the erythrocyte sedimentation rate with ICAS was analyzed.

Results—

In 178 of 786 patients (23%), 288 ICAS were observed. Most stenoses (n=194/288; 67%) were located in the posterior circulation arteries. In 59 of 786 patients (8%), ICAS were considered symptomatic. ICAS in the basilar artery and arteries beyond the circle of Willis were mainly noncalcified. In addition to age, gender, and several traditional cerebrovascular risk factors, erythrocyte sedimentation rate was independently associated with the presence of ICAS (OR, 1.20; 95% CI, 1.06–1.36) and with the presence of noncalcified ICAS in particular (OR, 1.20; 95% CI, 1.05–1.37).

Conclusions—

ICAS was observed in a noteworthy number of European stroke patients. Particularly, the majority of ICAS was observed in the posterior circulation, possibly conferring worse prognosis. ICAS in distal arteries were mainly noncalcified. Association of noncalcified ICAS and erythrocyte sedimentation rate may indicate a prominent role for inflammatory factors in intracranial atherosclerotic disease.
Risk and Cumulative Risk of Stroke Recurrence
Authors: Mohan Keerthi M. , Wolfe Charles D.A. , Rudd Anthony G. , Heuschmann Peter U. , Kolominsky-Rabas Peter L. , Grieve Andrew P.
Published: April 2011

Background and Purpose—

Estimates of risk of stroke recurrence are widely variable and focused on the short- term. A systematic review and meta-analysis was conducted to estimate the pooled cumulative risk of stroke recurrence.

Methods—

Studies reporting cumulative risk of recurrence after first-ever stroke were identified using electronic databases and by manually searching relevant journals and conference abstracts. Overall cumulative risks of stroke recurrence at 30 days and 1, 5, and 10 years after first stroke were calculated, and analyses for heterogeneity were conducted. A Weibull model was fitted to the risk of stroke recurrence of the individual studies and pooled estimates were calculated with 95% CI.

Results—

Sixteen studies were identified, of which 13 studies reported cumulative risk of stroke recurrence in 9115 survivors. The pooled cumulative risk was 3.1% (95% CI, 1.7–4.4) at 30 days, 11.1% (95% CI, 9.0–13.3) at 1 year, 26.4% (95% CI, 20.1–32.8) at 5 years, and 39.2% (95% CI, 27.2–51.2) at 10 years after initial stroke. Substantial heterogeneity was found at all time points. This study also demonstrates a temporal reduction in 5-year risk of stroke recurrence from 32% to 16.2% across the studies.

Conclusions—

The cumulative risk of recurrence varies greatly up to 10 years. This may be explained by differences in case mix and changes in secondary prevention over time However, methodological differences are likely to play an important role and consensus on definitions would improve future comparability of estimates and characterization of groups of stroke survivors at increased risk of recurrence.
The Initial Assignment Effect
Authors: Briscoe Forrest , Kellogg Katherine C.
Published: April 2011

One of the great paradoxes of inequality in organizations is that even when organizations introduce new programs designed to help employees in traditionally disadvantaged groups succeed, employees who use these programs often suffer negative career consequences. This study helps to fill a significant gap in the literature by investigating how local employer practices can enable employees to successfully use the programs designed to benefit them. Using a research approach that controls for regulatory environment and program design, we analyze unique longitudinal personnel data from a large law firm to demonstrate that assignment to powerful supervisors upon organization entry improves career outcomes for individuals who later use a reduced-hours program. Additionally, we find that initial assignment to powerful supervisors is more important to positive career outcomes—that is, employee retention and performance-based pay—than are factors such as supervisor assignment at the time of program use. Initial assignment affects career outcomes for later program users through the mechanism of improved access to reputation-building work opportunities. These findings have implications for research on work-family programs and other employee-rights programs and for the role of social capital in careers.
Specificity Controls for Immunocytochemical Methods
Authors: Burry Richard W.
Published: April 2011

Immunocytochemistry is used for antibody localization of proteins in cells and tissues. The specificity of the results depends on two independent criteria: the specificity of the antibody and of the method used. The antibody specificity is best determined by immunoblot and or immunoprecipitation. Absorption of the antibody with a protein does not determine that the antibody would have bound to the same protein in the tissue, and therefore is not a good control for antibody specificity. The specificity of the method is best determined by both a negative control, replacing the primary antibody with serum, and a positive control, using the antibody with cells known to contain the protein. With the increasing use of immunocytochemistry, it is important to be aware of the appropriate controls needed to show specificity of the labeling.
Ocrl1, a PtdIns(4,5)P2 5-Phosphatase, Is Localized to the Trans-Golgi Network of Fibroblasts and Epithelial Cells
Authors: Dressman Marlene Armitage , Olivos-Glander Isabelle M. , Nussbaum Robert L. , Suchy Sharon F.
Published: April 2011

PtdIns(4,5)P2 and PtdIns(4,5)P2 5-phosphatases play important roles in diverse aspects of cell metabolism, including protein trafficking. However, the relative importance of the PtdIns(4,5)P2 5-phosphatases in regulating PtdIns(4,5)P2 levels for specific cell processes is not well understood. Ocrl1 is a PtdIns(4,5)P2 5-phosphatase that is deficient in the oculocerebrorenal syndrome of Lowe, a disorder characterized by defects in kidney and lens epithelial cells and mental retardation. Ocrl1 was originally localized to the Golgi in fibroblasts, but a subsequent report suggested a lysosomal localization in a kidney epithelial cell line. In this study we defined the localization of ocrl1 in fibroblasts and in two kidney epithelial cell lines by three methods: immunofluorescence, subcellular fractionation, and a dynamic perturbation assay with brefeldin A. We found that ocrl1 was a Golgi-localized protein in all three cell types and further identified it as a protein of the trans-Golgi network (TGN). The TGN is a major sorting site and has the specialized function in epithelial cells of directing proteins to the apical or basolateral domains. The epithelial cell phenotype in Lowe syndrome and the localization of ocrl1 to the TGN imply that this PtdIns(4,5)P2 5-phosphatase plays a role in trafficking.
Laminin Chains in Developing and Adult Human Myotendinous Junctions
Authors: Pedrosa-Domellöf Fatima , Tiger Carl-Fredrik , Virtanen Ismo , Thornell Lars-Eric , Gullberg Donald
Published: April 2011

In addition to being the specialized site for transmission of force from the muscle to the tendon, the myotendinous junction (MTJ) also plays an important role in muscle splitting during morphogenesis. An early event in the formation of the MTJ is a regional deposition of basement membranes. We used immunocytochemistry to investigate the distribution of laminin chains during the development of MTJs in human limb muscle at 8-22 weeks of gestation (wg) and in adult MTJs. We used polyclonal antibodies and a new monoclonal antibody (MAb) against the human laminin α1 G4/G5 domains. At 8-10 wg, laminin α1 and laminin α5 chains were specifically localized to the MTJ. Laminin α1 chain remained restricted to the MTJ at 22 wg as the laminin β2 chain had appeared, whereas the laminin α5 chain became deposited along the entire length of the myotubes from 12 wg. In the adult MTJ, only vestigial amounts of laminin α1 and laminin α5 chains could be detected. On the basis of co-distribution data, we speculate that laminin α1 chain in the forming MTJ undergoes an isoform switch from laminin 1 to laminin 3. Our data indicate a potentially important role for laminin α1 chain in skeletal muscle formation.
Localization of S-adenosylhomocysteine Hydrolase in the Rat Kidney
Authors: Kloor Doris , Stumvoll Wolfgang , Schmid Heide , Kömpf Jost , Mack Andreas , Osswald Hartmut
Published: April 2011

S-adenosylhomocysteine (SAH) hydrolase is a cytosolic enzyme present in the kidney. Enzyme activities of SAH hydrolase were measured in the kidney in isolated glomeruli and tubules. SAH hydrolase activity was 0.62 ± 0.02 mU/mg in the kidney, 0.32 ± 0.03 mU/mg in the glomeruli, and 0.50 ± 0.02 mU/mg in isolated tubules. Using immunohistochemical methods, we describe the localization of the enzyme SAH hydrolase in rat kidney with a highly specific antibody raised in rabbits against purified SAH hydrolase from bovine kidney. This antibody crossreacts to almost the same extent with the SAH hydrolase from different species such as rat, pig, and human. Using light microscopy, SAH hydrolase was visualized by the biotin-streptavidin-alkaline phosphatase immunohistochemical procedure. SAH hydrolase immunostaining was observed in glomeruli and in the epithelium of the proximal and distal tubules. The collecting ducts of the cortex and medulla were homogeneously stained. By using double immunofluorescence staining and two-channel immunofluorescence confocal laser scanning microscopy, we differentiated the glomerular cells (endothelium, mesangium, podocytes) and found intensive staining of podocytes. Our results show that the enzyme SAH hydrolase is found ubiquitously in the rat kidney. The prominent staining of SAH hydrolase in the podocytes may reflect high rates of transmethylation.
Osteoclastic Tartrate-resistant Acid Phosphatase (Acp 5): Its Localization to Dendritic Cells and Diverse Murine Tissues
Authors: Hayman Alison R. , Bune Alison J. , Bradley John R. , Rashbass Jeremy , Cox Timothy M.
Published: April 2011

Tartrate-resistant acid phosphatase (TRAP) is a histochemical marker of the osteoclast. It is also characteristic of monohistiocytes, particularly alveolar macrophages, and is associated with diverse pathological conditions, including hairy cell leukemia and AIDS encephalopathy. To study the biology of this enzyme, we investigated its expression and activity in mouse tissues. Confocal fluorescence studies showed that TRAP is localized to the lysosomal compartment of macrophages. In adult mice, high activities of the enzyme were demonstrated in bone, spleen, liver, thymus, and colon, with lower amounts in lung, stomach, skin, brain, and kidney. Trace amounts were detected in testis, muscle, and heart. Expression of TRAP mRNA was investigated in tissue sections by in situ hybridization and protein expression was monitored by histochemical staining or immunohistochemically. TRAP is widely expressed in many tissues, where it is associated with cells principally originating from the bone marrow, including those of osteoclast/macrophage lineage. The cellular distribution of TRAP mRNA and enzyme antigen in the tissues corresponds closely to that of cells staining with an antibody directed to the CD80 (B7) antigen. Therefore, to confirm its putative localization in dendritic cells, isolated bone marrow dendritic cells were matured in culture. These co-stained strongly for TRAP protein and the CD80 antigen. These studies demonstrate that TRAP is a lysosomal enzyme that is found in diverse murine tissues, where it is expressed in dendritic cells as well as osteoclasts and macrophages, as previously shown.
Epithelial Dlx-2 Homeogene Expression and Cementogenesis
Authors: Lézot Frédéric , Davideau Jean-Luc , Thomas Bethan , Sharpe Paul , Forest Nadine , Berdal Ariane
Published: April 2011

The Dlx-2 (distal-less gene) homeoprotein transcription factor controls early tooth development but has not been studied during the late stages of biomineralization. Transgenic mice containing a Dlx-2/LacZ reporter construct were used to map the Dlx-2 expression pattern in cementoblasts, the dental cells most closely related to bone cells and therefore suggested to be uniquely positioned osteoblasts. During initial root formation, marked expression of Dlx-2 was evident in molar and incisor root epithelium, whereas dental papilla and follicle were negative. Dlx-2 was expressed in this epithelium from the apical loop to the area of its disruption. During acellular cementum formation in both incisors and molars, Dlx-2 expression was observed in the majority of differentiated cementoblasts from the apical region to the erupting zones. During cellular cementum formation, the presence of which characterizes growth-limited molars, Dlx-2 expression was restricted to the innermost cementoblasts and entrapped cementocytes. These data further support the hypothesis of a complex origin and fate of cementum-forming cells, as previously suggested by the expression patterns of a set of mesenchymal and epithelial markers, notably ameloblastin as shown here. Dlx-2 expression might constitute a landmark of cementoblast subpopulations of epithelial origin.
Quantitative Immunohistochemistry by Measuring Cumulative Signal Strength Using Commercially Available Software Photoshop and Matlab
Authors: Matkowskyj Kristina A. , Schonfeld Dan , Benya Richard V.
Published: April 2011

Currently available techniques for performing quantitative immunohistochemistry (Q-IHC) rely upon pixel-counting algorithms and therefore cannot provide information as to the absolute amount of chromogen present. We describe a novel algorithm for true Q-IHC based on calculating the cumulative signal strength, or energy, of the digital file representing any portion of an image. This algorithm involves subtracting the energy of the digital file encoding the control image (i.e., not exposed to antibody) from that of the experimental image (i.e., antibody-treated). In this manner, the absolute amount of antibody-specific chromogen per pixel can be determined for any cellular region or structure.
Heat-induced Alterations in the Localization of HSP72 and HSP73 as Measured by Indirect Immunohistochemistry and Immunogold Electron Microscopy
Authors: Ellis Sarah , Killender Marilyn , Anderson Robin L.
Published: April 2011

The heat shock proteins are a family of stress-inducible proteins that act as molecular chaperones for nascent proteins and assist in protection and repair of proteins whose conformation is altered by stress. HSP72 and HSP73 are two major cytosolic/nuclear stress proteins of mammalian cells, with extensive sequence homology. HSP73 is constitutively expressed, whereas HSP72 is highly stress-inducible. However, it is unclear why two isoforms are expressed and whether these two proteins have different functions in the cell. To assist in the delineation of function, we have completed a detailed study of the localization of HSP72 and HSP73 in the cell before and after heat stress, using two different methods of detection. By indirect immunohistochemistry, the localization of these two proteins is similar, cytoplasmic and nuclear in nonstressed cells with a translocation to nucleoli immediately after heat. By the more sensitive immunogold electron microscopy technique, differences in localization were noted. In nonstressed cells, HSP72 was primarily nuclear, localized in heterochromatic regions and in nucleoli. HSP73 was distributed throughout the cell, with most cytoplasmic label associated with mitochondria. Mitotic chromosomes were also heavily labeled. After stress, HSP72 concentrated in nuclei and nucleoli and HSP73 localized to nuclei, nucleoli, and cytoplasm, with increased label over mitochondria. These differences in localization suggest that the HSP72 and HSP73 may associate with different proteins or complexes and hence have different but overlapping functions in the cell.
A Qualitative and Quantitative Study on the Enkephalinergic Innervation of the Pig Gastrointestinal Tract
Authors: Porcher Christophe , Julé Yvon , Henry Monique
Published: April 2011

Enkephalins are involved in neural control of digestive functions such as motility, secretion, and absorption. To better understand their role in pigs, we analyzed the qualitative and quantitative distribution of enkephalin immunoreactivity (ENK-IR) in components of the intestinal wall from the esophagus to the anal sphincter. Immunohistochemical labelings were analyzed using conventional fluorescence and confocal microscopy. ENK-IR was compared with the synaptophysin immunoreactivity (SYN-IR). The results show that maximal ENK-IR levels in the entire digestive tract are reached in the myenteric plexuses and, to a lesser extent, in the external submucous plexus and the circular muscle layer. In the longitudinal muscle layer, ENK-IR was present in the esophagus, stomach, rectum, and anal sphincter, whereas it was absent from the duodenum to the distal colon. In the ENK-IR plexuses and muscle layers, more than 60% of the nerve fibers identified by SYN-IR expressed ENK-IR. No ENK-IR was observed in the internal submucous plexus and the mucosa; the latter was found to contain ENK-IR endocrine cells. These results strongly suggest that, in pigs, enkephalins play a major role in the regulatory mechanisms that underlie the neural control of digestive motility.
Expression of Prolactin mRNA in Rat Mammary Gland During Pregnancy and Lactation
Authors: Iwasaka Toshiki , Umemura Shinobu , Kakimoto Kochi , Koizumi Haruko , Osamura Yoshiyuki R.
Published: April 2011

We studied the expression of prolactin (PRL) mRNA in the mammary gland of resting, pregnant, lactating, and weanling rats using in situ and solution reverse transcriptase-polymerase chain reaction (RT-PCR). In mid- to late pregnancy and throughout lactation, PRL mRNA was detected in both in situ and solution RT-PCR. These PRL mRNA signals were clearly identified in the cytoplasm of alveolar and ductal mammary epithelial cells by the in situ RT-PCR method. In mid- to late pregnancy, such as at the initiating point of PRL mRNA expression, we confirmed in some cases a lack of PRL mRNA by solution RT-PCR. In addition, in the early weaning phase, no signals were detected by solution RT-PCR. However, slight focal signals were detected in some poorly vacuolated cytoplasm of regressing acinar cells by in situ RT-PCR. These findings suggest that PRL mRNA in rat mammary gland begins in mid- to late pregnancy in parallel with the development of the mammary gland, continues throughout lactation, and declines in the early phase of weaning, with regression of mammary epithelial cells.
The Cadherin-Catenin Complex Is Expressed Alternately with the Adenomatous Polyposis Coli Protein During Rat Incisor Amelogenesis
Authors: Sorkin Barbara C. , Wang Mark Y. , Dobeck Justine M. , Albergo Karen L. , Skobe Ziedonis
Published: April 2011

E-cadherin, a calcium-dependent cell-cell adhesion molecule, is expressed in highly specific spatiotemporal patterns throughout metazoan development, notably at sites of embryonic induction. E-cadherin also plays a critical role in regulating cell motility/ adhesion, cell proliferation, and apoptosis. We have used the continuously erupting rat incisor as a system for examining the expression of E-cadherin and the associated catenins [α-, β-, γ-catenin (plakoglobin) and p120ctn] during amelogenesis. Using immunhistochemical techniques, we observed expression of α-catenin and γ-catenin in ameloblasts throughout amelogenesis. In contrast, expression of E-cadherin, β-catenin, and p120ctn was strong in presecretory, transitional, and reduced stage ameloblasts (Stages I, III, and V) but was dramatically lower in secretory and maturation stage ameloblasts (Stages II and IV). This expression alternates with the expression pattern we previously reported for the adenomatous polyposis coli protein (APC), a tumor suppressor that competes with E-cadherin for binding to β-catenin. We suggest that alternate expression of APC and the cadherin-catenin complex is critical for the alterations in cell-cell adhesion and other differentiated cellular characteristics, such as cytoskeletal alterations, that are required for the formation of enamel by ameloblasts.