Abstract 3851: Temporal Distribution of Stroke Volumes and Clinical-Diffusion Mismatch in Patients with Proximal Arterial Occlusions

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Raul G Nogueira ◽  
David S Liebeskind ◽  
Leticia M Souza ◽  
Qing Hao ◽  
Karen Furie ◽  
...  
Keyword(s):  
Linear Regression ◽  
Infarct Volume ◽  
Linear Regression Analysis ◽  
Significant Proportion ◽  
Arterial Occlusion ◽  
Reperfusion Therapy ◽  
Poor Correlation ◽  
Lesion Volume ◽  
Collateral Flow ◽  
Over Time

Background and Purpose: Previous studies have demonstrated that the benefit of reperfusion therapy declines over time. The Clinical-Diffusion Mismatch (CDM) model has been suggested as surrogate for salvable tissue in acute ischemic stroke (AIS) patients. We sought to describe the temporal behavior profile of infarct volumes and CDM in patients suffering AIS due to proximal arterial occlusion (PAO). Methods: We performed a retrospective analysis of consecutive AIS patients admitted to two large academic institutions fulfilling the following criteria: (1) Baseline NIHSS ≥8; (2) PAO defined as MCA-M1, intracranial ICA, or tandem cervical + ICA/MCA-M1 occlusion on admission CTA/MRA; and (3) MRI-DWI performed ≤8 hours from time of stroke onset/last seen well (TSO). CDM was defined as baseline NIHSS ≥8 and DWI volume ≤25cc (as proposed by Davalos et al). Linear regression analysis was performed to define the changes on DWI lesion volume on presentation over time. The observed TSO to MRI were broken down into quartiles to look for any differences in the distribution of the baseline variables over time. Results: A total of 132 consecutive patients were identified (mean age, 66±16.8 years; 57% females; mean baseline NIHSS 17.5±5.3; occlusion site: MCA-M1, 64%; intracranial-ICA, 29%; tandem, 5%, mean TSO to DWI, 269.5±105.48 minutes). The mean DWI stroke volume on presentation was 46.7±54.8 cc (range, 0.19-436.1) and 63 (46.7%) patients had CDM. There was no significant changes in age, gender, baseline NIHSS, or occlusion site amongst the different time quartiles. Median infarct volume (cc) increased (quartile #1=8.5; #2=30.1; #3=38.5; #4=29.4) and the chances of having a CDM decreased (p<0.0001) across the different time quartiles. However, there was an overall poor correlation between DWI lesion volume on presentation and TSO to MRI (R-square=0.031, Figure ) and a significant proportion of the patients still had a CDM at later time epochs (#1=91.1%[20/22]; #2=47.8%[11/23]; #3=34.4%[21/61]; #4=42.3%[11/26]). Conclusions: Although infarct volume increases and the amount of penumbral tissue decreases over time, many patients with PAO will still have salvable penumbra at the later time epochs. This reflects individual differences in anatomic and physiological characteristics including the strength of collateral flow and highlights that selected patients may benefit from reperfusion therapy even at the later time windows. Figure : Relationship between Baseline DWI Volume (cc) and Time (minutes). Line is best fitted linear regression model.

Measurement and Prediction of Sound Exposure Levels by University Wind Bands

2010 ◽  
Vol 25 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Kris Chesky
Keyword(s):  
Linear Regression Analysis ◽  
Critical Role ◽  
Significant Proportion ◽  
Sound Exposure ◽  
Sound Levels ◽  
Wind Bands ◽  
Exposure Levels ◽  
The Mean ◽  
Over Time

The purpose of this study was to determine sound exposure levels generated in two college wind bands. Dosimeter data from a large sample of ensemble-based instructional activities (n = 43) was collected over time and processed to assess associations with predictor variables that may be relevant to this context, including indicators of time spend at various intensity levels, maximum and peak sound levels, degree of variability of sound levels over time, and the percentage of time playing music. The mean dose per event for the entire sample was 109.5% and ranged from 53.8% to 166.9%. Results of linear regression analysis revealed that regressors accounted for a significant proportion of the variance in dose (F = 128.42, p < 0.000) and a statistically significant and very large (96% variance accounted for) contribution to the prediction of dose. Findings implicate the critical role of the instructor and teaching pedagogy.

scholarly journals Effective reduction of infarct volume by gap junction blockade in a rodent model of stroke

1997 ◽  
Vol 2 (5) ◽  
pp. E3 ◽  
Author(s):  
Ahmed Rawanduzy ◽  
Anker Hansen ◽  
Thomas W. Hansen ◽  
Maiken Nedergaard
Keyword(s):  
Gap Junction ◽  
Spreading Depression ◽  
Therapeutic Potential ◽  
Infarct Volume ◽  
Arterial Occlusion ◽  
Histopathological Analysis ◽  
Infarction Volume ◽  
Effective Reduction ◽  
Lines Of Evidence ◽  
Over Time

Several lines of evidence indicate that the extent of ischemic injury is not defined immediately following arterial occlusion; rather that infarction expands over time. Episodes of spreading depression have been linked to this secondary increase in infarct volume. Tissue bordering the infarct fails to repolarize following spreading depression and is incorporated into the infarction. The result is that ischemic infarcts expand stepwise following each episode of spreading depression. Another line of evidence has demonstrated that gap junction blockers effectively inhibit spreading depression. These observations suggest that the efflux of potentially harmful cytosolic messengers from ischemic cells into surrounding nonischemic cells might cause amplification of injury in focal stroke. It is therefore conceivable that minimizing gap junction permeability might reduce final infarct volume. To test this hypothesis, the authors pretreated rats with the gap junction blocker, octanol, before occluding the middle cerebral artery and compared the sizes of the ischemic lesions to those in rats that received vehicle dimethyl sulfoxide prior to arterial occlusion. Histopathological analysis was performed 24 hours later. The 12 octanol-treated animals showed a significantly decreased mean infarction volume (80 ± 16 mm3) compared with the nine control rats (148 ± 9 mm3). In a separate set of experiments, the frequency of experimentally induced waves of spreading depression was evaluated following octanol treatment. Octanol pretreatment resulted in complete inhibition in two of nine animals, transient inhibition in five of nine, and no inhibition in two of nine. The results indicate that gap junction inhibitors, when not limited by toxicity, have significant therapeutic potential in the treatment of acute stroke.

ECOLOGICAL AND CULTURAL PRESSURE ON MARRIAGE SEASONALITY IN THE PRINCIPALITY OF ANDORRA

2008 ◽  
Vol 40 (1) ◽  
pp. 1-18 ◽  
Author(s):  
A. GONZÁLEZ-MARTÍN
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Middle Ages ◽  
Strong Dependence ◽  
Linear Regression Analysis ◽  
Marked Change ◽  
Service Industries ◽  
Political Independence ◽  
Over Time ◽  
Central Pyrenees

SummaryThe Principality of Andorra is a small European state located in the central Pyrenees. Since the Middle Ages, it has retained political independence from its two neighbouring countries, France and Spain. Until recently, Andorra maintained a relative stable population and was dependent upon agriculture and livestock. Since 1940, however, a marked change in these conditions has given rise to an explosive increase in the size of the population and traditional systems of production have been replaced by tourism, commerce and service industries. These changes have influenced the model of nuptial seasonality. Based on data from 10,188 marriage certificates covering a period from 1606 to 1960, nuptial seasonality was assessed by estimating Henry’s seasonality coefficient. Temporal and geographic changes in the seasonality model were assessed using linear regression analysis and analysis of variance. In addition, the Ũhindex – an estimate of the intensity of the seasonality model – is proposed to assess changes in the different seasonality models. The results indicate a relaxation of seasonality over time and in those parishes in which substantial demographic and socioeconomic change has occurred in recent years, suggesting a strong dependence of seasonality on the system of production.

scholarly journals Use of Robotic Anastomosis Competency Evaluation (RACE) tool for assessment of surgical competency during urethrovesical anastomosis

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Hijab Khan ◽  
Justen D. Kozlowski ◽  
Ahmed A. Hussein ◽  
Mohamed Sharif ◽  
Youssef Ahmed ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Patient Outcomes ◽  
Linear Regression Analysis ◽  
Objective Measure ◽  
Urinary Continence ◽  
Surgical Performance ◽  
Speed Range ◽  
Competency Evaluation ◽  
Over Time

Introduction: We sought to evaluate the Robotic Anastomosis Competency Evaluation (RACE) — a validated tool that objectively quantifies surgical skills specifically for urethrovesical anastomosis (UVA) — as a means to track progress of trainees, as well as to determine its predictive value. Methods: UVAs performed by trainees at our institution were evaluated using RACE over a period of two years. Trainees were supervised by an experienced robotic surgeon. Outcomes included traineerelated variables (RACE score, proportion of UVA performed by trainee, and suturing speed), and clinical outcomes (total UVA duration, postoperative urinary continence, and UVA-related complications). Significance was determined using linear regression analysis. Results: A total of 51 UVAs performed by six trainees were evaluated. Trainee RACE scores (19.8 to 22.3; p=0.01) and trainee proportion of UVA (67% to 80%; p=0.003) improved significantly over time. Trainee suture speed was significantly associated with RACE score (mean speed range 0.54–0.74 sutures/minute; p=0.03). Neither urinary continence at six weeks nor at six months was significantly associated with RACE score (p=0.17 and p=0.15, respectively), and only one UVA-related postoperative complication was reported. Conclusions: Trainee RACE scores improved and the proportion of UVA performed by trainees increased over time. RACE can be used as an objective measure of surgical performance during training. Strict mentor supervision allowed safe training without compromising patient outcomes.

scholarly journals Early Magnetic Resonance Imaging Prediction of Arterial Recanalization and Late Infarct Volume in Acute Carotid Artery Stroke

2003 ◽  
Vol 23 (2) ◽  
pp. 240-248 ◽  
Author(s):  
Marc Hermier ◽  
Norbert Nighoghossian ◽  
Patrice Adeleine ◽  
Yves Berthezène ◽  
Laurent Derex ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Infarct Size ◽  
Infarct Volume ◽  
Clinical Status ◽  
Multivariate Logistic Regression Analysis ◽  
Arterial Occlusion ◽  
Lesion Volume ◽  
Resonance Imaging ◽  
Lower Baseline

In patients with acute ischemic stroke, early recanalization may save tissue at risk for ischemic infarction, thus resulting in smaller infarcts and better clinical outcome. The hypothesis that clinical and diffusion- and perfusion-weighted imaging (DWI, PWI) parameters may have a predictive value for early recanalization and final infarct size was assessed. Twenty-nine patients were prospectively enrolled and underwent sequential magnetic resonance imaging (1) within 6 hours from hemispheric stroke onset, before thrombolytic therapy; (2) at day 1; and (3) at day 60. Late infarct volume was assessed by T2-weighted imaging. At each time, clinical status was assessed by the National Institutes of Health Stroke Scale (NIHSS). Twenty-eight patients had arterial occlusion at day 0 magnetic resonance angiography (MRA). They were classified into two groups according to day 1 MRA: recanalization (n = 18) versus persistent occlusion (n = 10). Any significant differences between these groups were assessed regarding (1) PWI and DWI abnormality volumes, (2) relative and absolute time-to-peak (TTP) and apparent diffusion coefficient within the lesion on DWI; and (3) day 60 lesion volume on T2-weighted imaging. Univariate and multivariate logistic regression analysis showed that the most powerful predictive factors for recanalization were lower baseline NIHSS score and lower baseline absolute TTP within the lesion on DWI. The best predictors of late infarct size were day 0 lesion volume on DWI and day 1 recanalization. Early PWI and DWI studies and day 1 MRA provide relevant predictive information on stroke outcome.

scholarly journals The effect of the molecular properties of calcium channel blockers on their elimination route

2015 ◽  
Vol 67 (3) ◽  
pp. 801-806
Author(s):  
Jasna Trbojevic-Stankovic ◽  
Jadranka Odovic ◽  
Ratomir Jelic ◽  
Dejan Nesic ◽  
Biljana Stojimirovic
Keyword(s):  
Molecular Weight ◽  
Linear Regression ◽  
Calcium Channel ◽  
Calcium Channel Blockers ◽  
Linear Regression Analysis ◽  
Relevant Literature ◽  
Molecular Properties ◽  
Poor Correlation ◽  
Channel Blockers ◽  
The Relationship

Calcium channel blockers (CCBs) are among the most widely used drugs in cardiovascular medicine. In this study, nine CCBs (amlodipine, felodipine, isradipine, nicardipine, nifedipine, nimodipine, nisoldipine, verapamil and diltiazem) were investigated to assess the relationship between their molecular properties and elimination data obtained from literature. The descriptors of the molecular properties of CCBs were calculated using three software packages. The relationship between computed molecular properties and elimination data collected from relevant literature, initially investigated with simple linear regression analysis, showed poor correlation (R2 <0.25). Application of molecular weight or volume data as additional independent variable, multiple linear regression (MLR) revealed better correlations (R2 ~ 0.38) between CCB renal and fecal elimination data and their lipophilicity. Excluding nimodipine from the calculations resulted in more acceptable correlations. The best correlations were established after computed lipophilicity descriptor and molecular weight were applied (R2 = 0.66 with acceptable probability value).

scholarly journals Short-duration hypothermia completed prior to reperfusion prevents intracranial pressure elevation following ischaemic stroke in rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel Omileke ◽  
Sara Azarpeykan ◽  
Steven W. Bothwell ◽  
Debbie Pepperall ◽  
Daniel J. Beard ◽  
...  
Keyword(s):  
Intracranial Pressure ◽  
Ischaemic Stroke ◽  
Short Duration ◽  
Infarct Volume ◽  
Arterial Occlusion ◽  
Reperfusion Therapy ◽  
Artery Occlusion ◽  
Experimental Stroke ◽  
Stroke Patients ◽  
Post Stroke

AbstractReperfusion therapies re-establish blood flow after arterial occlusion and improve outcome for ischaemic stroke patients. Intracranial pressure (ICP) elevation occurs 18–24 h after experimental stroke. This elevation is prevented by short-duration hypothermia spanning the time of reperfusion. We aimed to determine whether hypothermia-rewarming completed prior to reperfusion, also prevents ICP elevation 24 h post-stroke. Transient middle cerebral artery occlusion was performed on male outbred Wistar rats. Sixty-minute hypothermia to 33 °C, followed by rewarming was induced prior to reperfusion in one group, and after reperfusion in another group. Normothermia controls received identical anaesthesia protocols. ΔICP from pre-stroke to 24 h post-stroke was measured, and infarct volumes were calculated. Rewarming pre-reperfusion prevented ICP elevation (ΔICP = 0.3 ± 3.9 mmHg vs. normothermia ΔICP = 5.2 ± 2.1 mmHg, p = 0.02) and reduced infarct volume (pre-reperfusion = 78.6 ± 23.7 mm3 vs. normothermia = 125.1 ± 44.3 mm3, p = 0.04) 24 h post-stroke. There were no significant differences in ΔICP or infarct volumes between hypothermia groups rewarmed pre- or post-reperfusion. Hypothermia during reperfusion is not necessary for prevention of ICP rise or infarct volume reduction. Short-duration hypothermia may be an applicable early treatment strategy for stroke patients prior to- during-, and after reperfusion therapy.

scholarly journals Hypothermia and rewarming prior to reperfusion, prevents intracranial pressure elevation after ischaemic stroke in rats: an investigation to define the importance of cooling during reperfusion

2021 ◽  
Author(s):  
Daniel Omileke ◽  
Sara Azarpeykan ◽  
Steven W Bothwell ◽  
Debbie Pepperall ◽  
Daniel J Beard ◽  
...  
Keyword(s):  
Intracranial Pressure ◽  
Ischaemic Stroke ◽  
Short Duration ◽  
Infarct Volume ◽  
Arterial Occlusion ◽  
Reperfusion Therapy ◽  
Artery Occlusion ◽  
Experimental Stroke ◽  
Stroke Patients ◽  
Post Stroke

Abstract Reperfusion therapies re-establish blood flow after arterial occlusion and improve outcome for ischaemic stroke patients. Intracranial pressure (ICP) elevation occurs 18–24 h after experimental stroke. This elevation is prevented by short-duration hypothermia spanning the time of reperfusion. We aimed to determine whether hypothermia-rewarming completed prior to reperfusion, also prevents ICP elevation 24 h post-stroke. Transient middle cerebral artery occlusion was performed on male outbred Wistar rats. Sixty-minute hypothermia to 33℃, followed by rewarming was induced prior to reperfusion in one group, and after reperfusion in another group. Normothermia controls received identical anaesthesia protocols. ΔICP from pre-stroke to 24 h post-stroke was measured, and infarct volumes were calculated. Rewarming pre-reperfusion prevented ICP elevation (ΔICP = 0.3 ± 3.9 mmHg vs. normothermia ΔICP = 5.2 ± 2.1 mmHg, p = 0.02) and reduced infarct volume (pre-reperfusion = 78.6 ± 23.7 mm3 vs. normothermia = 125.1 ± 44.3 mm3, p = 0.04) 24 h post-stroke. There were no significant differences in ΔICP or infarct volumes between hypothermia groups rewarmed pre-or post-reperfusion. Hypothermia during reperfusion is not necessary for prevention of ICP rise or infarct volume reduction. Short-duration hypothermia is a broadly applicable potential early treatment strategy for stroke patients prior to- during-, and after reperfusion therapy.

scholarly journals Is Cancer Diagnosis Following Emergency Admission Due to Patient Delay or Systems Failure: New Insights from a Comprehensive Primary Care Dataset

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Michael Yule ◽  
Rosalind Adam ◽  
Peter Murchie
Keyword(s):  
Primary Care ◽  
Linear Regression ◽  
Cancer Diagnosis ◽  
Care Pathway ◽  
Linear Regression Analysis ◽  
Significant Proportion ◽  
Emergency Admission ◽  
Cancer Type ◽  
Cancer Symptoms ◽  
North East

ABSTRACT ObjectivesA significant proportion (13.9-21.8%) of cancers are diagnosed during emergency admissions to hospital. Patients who are diagnosed in this way have poorer outcomes. Cancer type, increasing age, and deprivation have shown to be associated with cancer diagnosis as an emergency. The role of primary care consulting behaviour prior to emergency presentation with a new cancer diagnosis is unclear and therefore the principle aim of the present study was to investigate this. ApproachAll GP practices in the North East of Scotland were invited to participate. 2015 patients with a diagnosis of either colorectal, upper GI, prostate, lung, breast and melanoma were randomly selected from participating practices. A dataset was created that contained routinely collected data from primary care records from these patients. This information was consolidated with information from the NHS Grampian Cancer Care pathway database. Those diagnosed by screening were removed, leaving 1803 patients. The main characteristic examined was whether or not the patient had seen a GP with relevant symptoms in the 2 years before the consultation that resulted in their diagnosis or referral. Chi squared analysis and univariate linear regression analysis was performed on each characteristic to examine the association of independent variables with each outcome. Multivariate linear regression was then carried out across the characteristics. Results362 (20.1%) of new cancer diagnosis were by emergency. Only 16.2% (n=260) of patients who saw their GP prior to their admission were diagnosed by emergency. 54.5% (n=97) of patients who had not seen their GP prior to diagnosis were emergency diagnoses. 20.7% (n=75) of patients diagnosed by emergency admission had been referred by their GP at the time of diagnosis and were awaiting their appointment with secondary care. Patients who had been seen in primary care before their cancer diagnosis were significantly less likely to have their cancer diagnosed by emergency admission (p<0.0001). ConclusionPatients who present to their GP with symptoms of cancer are much less likely to be diagnosed as a result of an emergency admission. It is therefore postulated that GPs are adequately referring patients with cancer for further investigation and diagnosis. However around a fifth of patients overall are still being diagnosed through emergency admission to hospital, and in the majority of cases this is because they are not presenting themselves to primary care. In order to rectify this we suggest that greater awareness about cancer symptoms amongst the public is necessary.

The Effects of Azacitidine on Quality of Life Measured Longitudinally In MDS Patients Treated at a Tertiary Care Center

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2571-2571
Author(s):  
Sarah A. Ingber ◽  
Kim Thompson ◽  
Adam Lam ◽  
Alex Mamedov ◽  
Liying Zhang ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Regression Analysis ◽  
Linear Regression ◽  
Predictive Factors ◽  
Physical Functioning ◽  
Linear Regression Analysis ◽  
Clinically Significant ◽  
Over Time

Abstract Abstract 2571 Background: Myelodysplastic syndromes (MDS) are clonal hematopoetic stem cell disorders characterized by ineffective hematopoiesis and a propensity to develop AML predicted by conventional scoring systems such as the International Prognostic Scoring System (IPSS). Azacitidine (AZA), a hypomethylating agent is indicated for high and high intermediate IPSS scores based on survival and leukemia-free survival benefits demonstrated in randomized trials (Silverman 2002, 2006, Fenaux 2009). Additionally, improvements in fatigue, dyspnea, physical functioning, affect and psychological distress were demonstrated in the CALGB study (Kornblith 2002). We previously showed that most symptom and functional domains of quality of life (QOL) are impaired in MDS patients measured by several instruments and are primarily determined by Hb and transfusion dependence (Buckstein 2009). With the exception of the CALGB paper, there is a paucity of data assessing the ‘real world' QOL in MDS patients treated with AZA longitudinally. All consented patients with MDS followed at our center have QOL assessed every 3–4 months as part of routine care. We present the QOL scores of patients on AZA as assessed by the EORTC QLQ-C30, EQ-5D and a global fatigue scale. Methods: Clinically significant score differences were considered to be 10 points for the EORTC, and 0.05 for the EQ-5D. Linear regression analysis was used to detect each QOL change over time. Log-transformation was applied for all QOL scores to normalize the distribution. To search for significant predictive factors of each QOL, linear regression analysis (for continuous predictive factors) or Analysis of Variance (for binary predictive factors) was conducted at baseline. A two-sided p-value less than 0.05 was considered statistically significant. Results: 30 patients in our database were/are currently treated with AZA. The median age was 73 years, with 63% being male. Of the 26 patients with measureable IPSS scores, 54% were high/high intermediate risk. Seventy percent had a Hb <100 at the time of baseline QOL prior to AZA, 50% had a ferritin ≥ 1000 ug/L, 65% were transfusion dependent (TD) as defined by the WPSS (Malcovati 2007). Sixty-seven percent of patients were on AZA for ≥ 4 cycles of treatment. Of the 19 TD patients only 3 became transfusion independent (TI) on AZA and 3 patients who were TI at baseline became TD. Of the 30 patients, 20 have QOL data available for analysis with a median follow up time of 10 weeks (range 0–80) and an interval duration between QOL assessments of 15.5 weeks. Fourteen out of twenty patients have serial QOL assessments, 5 with two, 9 with three or more. The only clinically significant improvements were observed with the EORTC physical functioning and fatigue subscales but constipation scores were higher and global health status/QOL deteriorated over time (Figure 1). At baseline assessment ferritin ≥ 1000 ug/L was negatively associated with physical functioning (p=.0007), cognitive functioning (p=.0012), global QOL (p=.0048) and global fatigue (p=.0003) while transfusion dependence was not predictive of QOL scores. No significant clinical improvements were detected by linear regression or ANOVA over time, but constipation worsened using both models. The health utilities (determined by the summary score of the EQ-5D) are seen in table 1. Conclusion: Many clinically important function and symptom domains of 3 different QOL instruments have not changed significantly over time in our patients receiving AZA. This is likely explainable by the limited sample size and serial number of assessments in our patients. Our present patient population is higher risk than that tested in the CALGB study and our previous report on the MDS patients in our database. Furthermore, we have yet to see the rates of transfusion independence that might be associated with improved QOL. The negative association of increased ferritin with numerous symptom and function scores may simply be a surrogate for the extent of transfusion dependence. We hope that with longer follow up and larger sample size, we will be able to reproduce the QOL benefits observed in the pivotal CALGB trial (Kornblith 2002). Disclosure: No relevant conflicts of interest to declare.

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