High-performance monolayer MoS2nanosheet GAA transistor

In this article, a 0.7 nm thick monolayer MoS2nanosheet gate-all-around field effect transistors (NS-GAAFETs) with conformal high-κmetal gate deposition are demonstrated. The device with 40 nm channel length exhibits a high on-state current density of ~410μAμm-1with a large on/off ratio of 6 × 108at drain voltage = 1 V. The extracted contact resistance is 0.48 ± 0.1 kΩμm in monolayer MoS2NS-GAAFETs, thereby showing the channel-dominated performance with the channel length scaling from 80 to 40 nm. The successful demonstration of device performance in this work verifies the integration potential of transition metal dichalcogenides for future logic transistor applications.

Tmax Volumes Predict Final Infarct Size and Functional Outcome in Ischemic Stroke Patients Receiving Endovascular Treatment

OBJECTIVE

The objective of this paper was to explore the utility of time to maximum concentration (T_max )-based target mismatch on computed tomography perfusion (CTP) in predicting radiological and clinical outcomes in patients with acute ischemic stroke (AIS) with anterior circulation large vessel occlusion (LVO) selected for endovascular treatment (EVT).

METHODS

Patients with AIS underwent CTP within 24 hours from onset followed by EVT. Critically hypoperfused tissue and ischemic core volumes were automatically calculated using T_max thresholds >9.5 seconds and >16 seconds, respectively. The difference between T_max  > 9.5 seconds and T_max  > 16 seconds volumes and the ratio between T_max  > 9.5 seconds and T_max  > 16 seconds volumes were considered ischemic penumbra and T_max mismatch ratio, respectively. Final infarct volume (FIV) was measured on follow-up non-contrast computed tomography (CT) at 24 hours. Favorable clinical outcome was defined as 90-day modified Rankin Scale 0 to 2. Predictors of FIV and outcome were assessed with multivariable logistic regression. Optimal T_max volumes for identification of good outcome was defined using receiver operating curves.

RESULTS

A total of 393 patients were included, of whom 298 (75.8%) achieved successful recanalization and 258 (65.5%) achieved good outcome. In multivariable analyses, all T_max parameters were independent predictors of FIV and outcome. T_max  > 16 seconds volume had the strongest association with FIV (beta coefficient = 0.596 p <0.001) and good outcome (odds ratio [OR] = 0.96 per 1 ml increase, 95% confidence interval [CI] = 0.95-0.97, p < 0.001). T_max  > 16 seconds volume had the highest discriminative ability for good outcome (area under the curve [AUC] = 0.88, 95% CI = 0.842-0.909). A T_max  > 16 seconds volume of ≤67 ml best identified subjects with favorable outcome (sensitivity = 0.91 and specificity = 0.73).

INTERPRETATION

T_max target mismatch predicts radiological and clinical outcomes in patients with AIS with LVO receiving EVT within 24 hours from onset. ANN NEUROL 2022;91:878-888.

Confirmatory Study of Time-Dependent Computed Tomographic Perfusion Thresholds for Use in Acute Ischemic Stroke

Background and Purpose—

Computed tomographic perfusion (CTP) thresholds associated with follow-up brain infarction may differ by time from symptom onset to imaging and reperfusion. We confirm CTP thresholds over time to imaging and reperfusion in patients with acute ischemic stroke from the HERMES collaboration (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials) data.

Methods—

Patients with occlusion on CT angiography were acutely imaged with CTP. Noncontrast CT and magnetic resonance-diffusion weighted imaging at 24 to 48 hours defined follow-up infarction. Reperfusion was assessed on conventional angiogram. Tmax, cerebral blood flow (CBF), and cerebral blood volume maps were derived from delay-insensitive CTP postprocessing. These parameters were analyzed using receiver operator characteristics to derive optimal thresholds based on time from stroke onset-to-CTP or to reperfusion. ANOVA and linear regression were used to test whether the derived CTP thresholds were different by time.

Results—

One hundred thirty-seven patients were included. Tmax thresholds of >15.7 s and >15.8 s and absolute CBF thresholds of <8.9 and <7.5 mL·min −1 ·100 g −1 for gray matter and white matter respectively were associated with infarct if reperfusion was achieved <90 minutes from CTP with stroke onset-to-CTP <180 minutes. The discriminative ability of cerebral blood volume was modest. There were no statistically significant relationships between stroke onset-to-CTP time and Tmax, CBF, and cerebral blood volume thresholds (all P >0.05). A statistically significant relationship was observed between CTP-to-reperfusion time and the optimal thresholds for Tmax ( P <0.001) and CBF ( P <0.001). Similar but more modest relationship was noted for onset-to-reperfusion time and optimal thresholds for CBF ( P ≤0.01).

Conclusions—

CTP thresholds based on stroke onset and imaging time and taking into account time needed for reperfusion may improve infarct prediction in patients with acute ischemic stroke.

Effects of whole body vibration on spinal proprioception in healthy individuals

BACKGROUND

Low back pain (LBP) is a common health problem with high reoccurrence rate. As patients with LBP are often found to be proprioception impaired, new proprioception exercises should be explored. Whole body vibration (WBV) has been proven to improve muscle function and proprioception.

OBJECTIVE

The aim of this study was to determine the effects of WBV on spinal proprioception when WBV was administered in standing and seated postures.

METHODS

Twenty healthy male individuals (mean age: 23.2±1.2 years) were recruited and randomly assigned to two WBV groups: WBV in standing or WBV in seated posture. Their body posture, lumbar repositioning ability, maximum reaching distance and lumbopelvic coordination during dynamic motion in flexion and extension were assessed before, immediately after, 30 minutes after and 1 hour after 5 minutes of WBV (18 Hz, 6 mm amplitude) exposure. A Mixed ANOVA was used to analyze the effects of group and time factors on these four outcome measures.

RESULTS

There were no significant interaction (group and time) and group effects on all outcome measures. Participants were found to have significant different time effect on body posture, lumbar repositioning ability, maximum reaching distance and lumbopelvic coordination.

CONCLUSIONS

WBV could significantly improve spinal proprioception including body posture, lumbar repositioning ability, maximum reaching distance and lumbopelvic coordination in healthy individuals. WBV protocol is recommended to confirm its clinical application for improving spinal proprioception and its effects on patients with LBP is warranted.

CXCR3-deficient mesenchymal stem cells fail to infiltrate into the nephritic kidney and do not ameliorate lupus symptoms in MRL. Faslpr mice

Mesenchymal stem cell therapy is a promising candidate for the treatment of systemic lupus erythematosus (SLE). To exert their efficacy fully, mesenchymal stem cells must infiltrate efficiently into the lesion sites. Here, we examined the role of CXCR3 in mesenchymal stem cell infiltration into the kidney of MRL. Fas^lpr mice, which highly expressed CXCL10. The phenotypes, production of immunosuppressive mediators, and capacity to inhibit T and B cells of CXCR3-deficient mesenchymal stem cells were similar to those of wild-type mesenchymal stem cells. However, they showed less infiltration into the nephritic kidney, less conjugation with endothelial cells and weaker MMP-9 expression than did wild-type mesenchymal stem cells. Consequently, CXCR3-deficient mesenchymal stem cells did not ameliorate lupus symptoms in MRL. Fas^lpr mice in comparison with wild-type mesenchymal stem cells. In summary, our data suggest that upregulation of CXCR3 in mesenchymal stem cells will be a good strategy to increase their infiltration into the kidney, which will improve therapeutic outcomes in SLE.

Using the chronic kidney disease guidelines to evaluate the renal safety of tenofovir disoproxil fumarate in hepatitis B patients

BACKGROUND

Renal dysfunction remains an issue in tenofovir disoproxil fumarate (TDF) for chronic hepatitis B (CHB) patients.

AIM

To evaluate renal safety of TDF according to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines.

METHODS

We retrospectively recruited CHB patients who received either TDF or entecavir (ETV) monotherapy from January 2008 to August 2015. After excluding confounding conditions, 253 patients who received TDF were randomly matched 1:2 with 506 patients who received ETV through the propensity scores, which consisted of age, gender, cirrhosis, chronic kidney disease (CKD) and estimated glomerular filtration rate (eGFR). Renal function deterioration was defined as a drop in GFR category accompanied with a ≥25% eGFR decline. Cumulative incidences of and hazard ratios (HRs) for renal dysfunction were analysed.

RESULTS

The mean eGFR decline was significantly greater in the TDF group over 48 months (TDF vs ETV: 15.73 mL/min/1.73 m² , 95% confidence interval [CI]: 13.76-17.70 vs 5.96 mL/min/1.73 m² , 95% CI: 4.72-7.19; P < 0.001). The cumulative incidence of renal function deterioration was significantly higher in the TDF group (TDF vs ETV: 11.1%, 95% CI: 7.4-14.8 vs 1.7%, 95% CI: 1.0-2.4; P < 0.001). After adjusting for age, pre-existing CKD and diabetes, TDF was independently associated with an increased risk of renal function deterioration (HR 5.36, 95% CI: 2.16-13.35; P < 0.001). Pre-existing CKD (HR 6.71, 95% CI: 2.25-17.65), proteinuria (HR 3.39, 95% CI: 1.23-9.39), and haematuria (HR 4.25, 95% CI: 1.32-13.68) were also independent factors of renal dysfunction.

CONCLUSION

By following the KDIGO guidelines, we confirmed that TDF was associated with a higher risk of renal dysfunction as compared to ETV.

Blunt Abdominal Trauma with Left Kidney Dropped into Lower Retroperitoneal Cavity: A Case Report and Literature Review

Blunt abdominal injury with kidney laceration is not unusually seen in high-energy traffic accident. It can present with no symptoms and yet lead to fatal complications. High-grade lacerations of kidney (American Association for the Surgery of Trauma [AAST] grade IV to V) will show up with contrast extravasation and disrupted kidney/pelvicalyceal system morphology in computed tomography (CT). However, it is rare to see kidney dislocation from retroperitoneal space because of the presence of the Gerota's fascia. We present a case of a 16-year-old boy suffering from traffic accident with blunt truncal/abdominal injury. The contrast CT of abdomen revealed that his left kidney was dislocated from the original retroperitoneal space and sagged to the lower retroperitoneal cavity. We performed emergency left nephrectomy. He recovered well and there was no complication noted after the surgical intervention. We also review the literature of kidney laceration regarding diagnosis and treatment. (Hong Kong j.emerg.med. 2016;24:176-179)

Secondary polycythaemia in a Malay girl with homozygous Hb Tak

Hb Tak is one of more than 200 high affinity haemoglobin variants reported worldwide. It results from the insertion of two nucleotides (AC) at the termination codon, between codon 146 and codon 147 of the beta-globin gene [Beta 147 (+AC)]. Polycythaemia is the main clinical feature although affected carriers are usually asymptomatic and do not require intervention. Several case studies in this region have reported the co-inheritance of Hb Tak with Hb E, delta beta and beta thalassaemia with one case of homozygous Hb Tak in a Thai boy. In this case report, a cluster of haemoglobin Tak was found in a family of Malay ethnic origin. Cascade family screening was conducted while investigating a 4-year old girl who presented with symptomatic polycythaemia. She had 2 previous Hb analysis done, at 7-month and 2-year-old with the diagnosis of possible Hb Q Thailand and Homozygous Hb D, respectively. Both diagnosis did not fit her clinical presentations. She was plethoric, had reduced exercise tolerance as well as cardiomyopathy. Her parents were consanguineously married and later diagnosed as asymptomatic carriers of Hb Tak. Consequently, re-analysis of the girl's blood sample revealed a homozygous state of Hb Tak. In conclusion, high oxygen affinity haemoglobin like Hb Tak should be considered in the investigation of polycythaemic patients with abnormal Hb analyses. In this case, DNA analysis was crucial in determining the correct diagnosis.

Disruption of effective connectivity from the dorsolateral prefrontal cortex to the orbitofrontal cortex by negative emotional distraction in obsessive-compulsive disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) has been associated with abnormal cognitive and emotional functions and these dysfunctions may be dependent on the disruption of dynamic interactions within neuronal circuits associated with emotion regulation. Although several studies have shown the aberrant cognitive-affective processing in OCD patients, little is known about how to characterize effective connectivity of the disrupted neural interactions. In the present study, we applied effective connectivity analysis using dynamic causal modeling to explore the disturbed neural interactions in OCD patients.

METHOD

A total of 20 patients and 21 matched healthy controls performed a delayed-response working memory task under emotional or non-emotional distraction while undergoing functional magnetic resonance imaging.

RESULTS

During the delay interval under negative emotional distraction, both groups showed similar patterns of activations in the amygdala. However, under negative emotional distraction, the dorsolateral prefrontal cortex (DLPFC) and the orbitofrontal cortex (OFC) exhibited significant differences between groups. Bayesian model averaging indicated that the connection from the DLPFC to the OFC was negatively modulated by negative emotional distraction in patients, when compared with healthy controls (p < 0.05, Bonferroni-corrected).

CONCLUSIONS

Exaggerated recruitment of the DLPFC may induce the reduction of top-down prefrontal control input over the OFC, leading to abnormal cortico-cortical interaction. This disrupted cortico-cortical interaction under negative emotional distraction may be responsible for dysfunctions of cognitive and emotional processing in OCD patients and may be a component of the pathophysiology associated with OCD.

Abstract TP44: Low Cerebral Blood Flow (CBF) at Baseline Best Predicts Parenchymal Hematoma (PH) Post Revascularization Therapy

Introduction: In patients with acute ischemic stroke (AIS), parenchymal hematoma (PH) after revascularization therapy can lead to clinical deterioration and is often unpredictable. We sought to examine the association between admission CT perfusion (CTP) parameters (cerebral blood volume (CBV), cerebral blood flow (CBF), and Tmax) and PH in a case-controlled sample of patients receiving intravenous tPA ± endovascular treatment when using an industry standard CTP algorithm.

Hypothesis: We hypothesize that CTP derived parameters (CBV, CBF, and Tmax) can predict PH in AIS.

Methods: PH was classified according to ECASS II criteria. Two-phase (150s) and single-phase (66s) CTP acquisitions were performed within 12hrs of ictus. CTP 4D(GE Healthcare) delay-insensitive software was used to calculate CBF, CBV, and Tmax maps. Ipsilateral hemisphere gray and white matter (GM, WM) were flooded to determine volumes (mm3) for 3 lesion types: 1) patient-specific very low CBV (vlCBV) thresholds derived from the lower 10th, 5th and 2.5th percentiles of the contralateral hemisphere, 2) very low CBF threshold of ≤7ml/(min·100g), and 3) very high Tmax threshold of ≥16s. To correct for varying scan coverage, ratio of threshold output volume by ipsilateral hemisphere volume within slices that contained lesions was obtained. Receiver operating characteristic (ROC) analysis was used to compare models to determine which CTP parameter best predicted PH.

Results: 34 AIS patients (18 PH, 16 no hemorrhage) were included. Very low CBF threshold of ≤7ml/(min·100g) best predicted the occurrence of PH post revascularization therapy (p < 0.001; comparison of c-statistic). CBV and Tmax parameters were not discriminative of PH. (See Figure 1 for comparison of c- statistics).

Conclusion: When using a delay insensitive industry standard CTP paradigm, very low CBF≤7ml/(min·100g) has the ability in predicting PH post revascularization therapy.

A Longitudinal Study of Compensated Dating and Juvenile Prostitution Behaviors Among Adolescents in Hong Kong

STUDY OBJECTIVE

The purpose of this study was to examine longitudinal changes in compensated dating (CD) and juvenile prostitution (JP) behaviors and related psychosocial correlates among Hong Kong adolescents.

DESIGN, SETTING, AND PARTICIPANTS

In this study, adolescent CD and JP behaviors were examined in 3 waves (namely wave 2, 3, and 4) of a longitudinal study. At wave 2 (2010-2011), 3638 secondary 2 students (grade 8) from 28 schools participated in the study (mean age, 13.60 years; SD = 0.72). In the following 2 academic years (2011-2012 and 2012-2013), they were invited to respond to the same questionnaire. A total of 2921 students completed the questionnaire in 3 waves and their results were analyzed.

RESULTS

The number of CD cases was higher than JP cases. Although there was a decline in CD cases at wave 4, the number of JP cases increased at wave 4. Although there was some support for the influence of family intactness and positive youth development on CD and JP, the evidence was not strong. The effects of gender, economic disadvantage, and family functioning on CD and JP were not significant.

CONCLUSION

There was a decrease in CD but an increase in JP in the 3 waves of data. However, there was a fluctuation of CD over the years which made it difficult to identify a stable pattern. Some possible explanations for such a fluctuation and the related nonsignificant findings are proposed.

Abstract W P27: Quantitative Measurement Of Blood Flow Around Intravascular Thrombus Using CT Perfusion T0 Maps

Introduction: Anterograde blood flow around thrombus and extent of retrograde collateral filling can affect thrombus lysis with IV tPA. Current assessment of blood flow around thrombus is however very subjective. The aim of the present study is to validate a newly devised method to quantify blood flow around thrombus using CT perfusion (CTP) T0 maps.

Methods: From the Prove-IT stroke-imaging database, perfusion CT and DSA images of stroke patients treated with IV tPA and/or IA thrombolysis were analyzed. We generated maps that measure delay in arrival time of contrast within the intracranial arterial tree (T0 maps) from that of the chosen arterial input function. A “positive sloped” regression line of T0 values from distal clot interface to at least 14 pixels (median 68 pixels) along the artery profile indicated presence of occult anterograde flow. Anterograde flow thus measured using the T0 maps was compared with anterograde flow assessed on first angiography of subsequent IA procedure.

Results: Of 37 patients (mean age 66 ± 13.5 years, 20 female), 35 (94.6%) were treated with IV tPA before DSA. Median time from CTP to first run angiography was 83 mins (IQR 53-100 mins). Positive slope were noted in 10 patients. Patients who had anterograde flow on first angiography were 10. Compared with anterograde flow on first run angio, positive slope on T0 map had a sensitivity of 80%, specificity of 92.6% and a positive predictive value of 80% and negative predictive value of 92.6%. In patients with anterograde flow on first angiography, median T0 time at proximal clot interface was 0.1 seconds (IQR 0-0.1) and at distal clot interface was 0.7 seconds (IQR 0.5-3.1). In patients without any anterograde flow on first angio, median T0 time at proximal clot interface was 0.1 seconds (IQR 0-0.3) while that at distal clot interface was 3.7 seconds (IQR 2.1-5.6).

Conclusions: The slope method on CTP T0 maps and measurement of T0 values around clot reliably measure presence of anterograde blood flow through thrombus.

Cognitive functioning in obsessive-compulsive disorder: a meta-analysis

BACKGROUND

Substantial empirical evidence has indicated impairment in the cognitive functioning of patients with obsessive-compulsive disorder (OCD) despite inconsistencies. Although several confounding factors have been investigated to explain the conflicting results, the findings remain mixed. This study aimed to investigate cognitive dysfunction in patients with OCD using a meta-analytic approach.

METHOD

The PubMed database was searched between 1980 and October 2012, and reference lists of review papers were examined. A total of 221 studies were identified, of which 88 studies met inclusion criteria. Neuropsychological performance and demographic and clinical variables were extracted from each study.

RESULTS

Patients with OCD were significantly impaired in tasks that measured visuospatial memory, executive function, verbal memory and verbal fluency, whereas auditory attention was preserved in these individuals. The largest effect size was found in the ability to recall complex visual stimuli. Overall effect estimates were in the small to medium ranges for executive function, verbal memory and verbal fluency. The effects of potentially confounding factors including educational level, symptom severity, medication status and co-morbid disorders were not significant.

CONCLUSIONS

Patients with OCD appear to have wide-ranging cognitive deficits, although their impairment is not so large in general. The different test forms and methods of testing may have influenced the performance of patients with OCD, indicating the need to select carefully the test forms and methods of testing used in future research. The effects of various confounding variables on cognitive functioning need to be investigated further and to be controlled before a definite conclusion can be made.

Toward patient-tailored perfusion thresholds for prediction of stroke outcome

BACKGROUND AND PURPOSE

Multiple patient-specific clinical and radiologic parameters impact traditional perfusion thresholds used to classify/determine tissue outcome. We sought to determine whether modified baseline perfusion thresholds calculated by integrating baseline perfusion and clinical factors better predict tissue fate and clinical outcome.

MATERIALS AND METHODS

CTP within 4.5 hours of acute anterior circulation stroke onset and 5- to 7-day MR imaging were performed for 203 patients with stroke, divided into derivation (n = 114) and validation (n = 89) data bases. Affected regions were operationally classified as infarct and noninfarct according to baseline CTP and follow-up FLAIR imaging. Perfusion thresholds were derived for each of the infarct and noninfarct regions, without and with transformation by baseline clinical and radiologic variables by using a general linear mixed model. Performance of transformed and nontransformed perfusion thresholds for tissue fate and 90-day clinical outcome prediction was then tested in the derivation data base. Reproducibility of models was verified by using bootstrapping and validated in an independent cohort.

RESULTS

Perfusion threshold transformation by clinical and radiologic baseline parameters significantly improved tissue fate prediction for both gray matter and white matter (P < .001). Transformed thresholds improved the 90-day outcome prediction for CBF and time-to-maximum (P < .001). Transformed relative CBF and absolute time-to-maximum values demonstrated maximal GM and WM accuracies in the derivation and validation cohorts (relative CBF GM: 91%, 86%; WM: 86%, 83%; absolute time-to-maximum 88%, 79%, and 80%, 76% respectively).

CONCLUSIONS

Transformation of baseline perfusion parameters by patient-specific clinical and radiologic parameters significantly improves the accuracy of tissue fate and clinical outcome prediction.

Effects of whole body vibration on spinal proprioception in normal individuals

Low back pain (LBP) is a common health problem with high reoccurrence rate. While most LBP cases are classified as non-specific, patients in general often present impaired proprioception. Whole body vibration (WBV) has been proven to improve muscle function and proprioception in the lumbo-pelvic region. The aim of this study was to determine whether WBV would affect spinal proprioception. Eleven young normal individuals were recruited. Their body alignment, lumbar repositioning error and lumbo-pelvic coordination during dynamic motion were assessed before and after 5 minutes WBV (18 Hz, 6 mm amplitude). Assessments were conducted before, immediately after, 30 minutes after and 1 hour after WBV. Subjects were found to have improved lumbo-pelvic coordination and flexibility without any adverse effect on the neuromuscular system after WBV. However, WBV had no significant immediate effect on lumbar repositioning ability and body alignment. Future studies of the effects of different WBV protocols on LBP patients are recommended.

The efficacy of i-SCAN for detecting reflux esophagitis: a prospective randomized controlled trial

New imaging technologies have been applied in endoscopy to improve the detection and differentiation of subtle mucosal changes using a digital contrast method. Among them, i-SCAN technology is the most recently developed image-enhancing technology. We investigated whether i-SCAN could improve the detection rate of reflux esophagitis. Interobserver agreement between endoscopists was compared with conventional white light (WL) endoscopic examination. We performed a prospective randomized controlled trial. A consecutive series of 514 subjects that underwent an esophagogastroduodenoscopy for health inspection were enrolled and randomized into the i-SCAN group (n = 246) and WL group (n = 268). An esophagogastroduodenoscopy with video recording was used for detecting reflux esophagitis, and reflux esophagitis were categorized by the modified Los Angeles (LA) classification. The total number of reflux esophagitis identified by WL and i-SCAN was 58 (21.7%) and 74 (30.1%), respectively. The diagnostic yield of reflux esophagitis was significantly higher (P = 0.034) in the i-SCAN group (30.1%) as compared to the WL group (21.6%). Using the modified LA classification, the detection rate of minimal changes was significantly higher (P = 0.017) in the i-SCAN group (11.8%) as compared to the WL group (5.6%), but the detection rates of LA-A and LA-B were not significantly different between the two groups (P = 0.897 and P = 0.311, respectively). After comparison of the interobserver agreement using randomly selected video clips, the i-SCAN group showed better agreement than the WL group (Kappa value, 0.793 vs. 0.473). Compared to WL endoscopy, applying i-SCAN in daily practice can improve the diagnostic yield of reflux esophagitis by detecting more minimal changes in the squamo-columnar junction of the esophagus and can improve the interobserver agreement of the modified Los Angeles classification.

An assessment of three noncommercial DNA extraction methods from dried blood spots for beta-thalassaemia mutation identification

INTRODUCTION

Dried blood spots (DBS) are currently the recommended sample collection method for newborn screening programmes in America. Early diagnosis of beta-thalassaemia screening is essential as it provides an added advantage especially in sickle cell disease. Beta-thalassaemia frequency is high in many poor countries, and the cost of using commercial DNA extraction kits can be prohibitive. Our study assessed three methods that use minimal reagents and materials to extract DNA from DBS for beta-thalassaemia identification.

METHODS

The methods assessed in this study were Tris-EDTA (TE) buffer-based method by Bereczky et al. (American Journal of Tropical Medicine and Hygiene 72, 2005, 249), NaCL/NaOH/Sodium dodecyl sulphate (SDS) method by Huang et al. (Human Genetics 84, 1990, 129) and NaOH method by Zhou et al. (Analytical Biochemistry 354, 2006, 159). Extracted DNA was amplified for three common beta-thalassaemia mutations in Malaysia.

RESULTS

Amplicons derived from TE buffer-based method were very faint and almost nonexistent while the NaCl/NaOH/SDS method did not produce any visible amplicons. The extraction using NaOH method produced visible bands that were comparable to the standard method using extraction kit.

CONCLUSION

The NaOH method is a simple method that uses minimal equipment and reagents that make it labour- and cost-effective. This method could be adopted by poorer countries to extract DNA for beta-thalassaemia mutation characterization.

Early rate of contrast extravasation in patients with intracerebral hemorrhage

BACKGROUND AND PURPOSE

For patients with ICH, knowing the rate of CT contrast extravasation may provide insight into the pathophysiology of hematoma expansion. This study assessed whether the PCT-derived PS can measure different rates of CT contrast extravasation for admission CTA spot signs, PCCT, PCL, and regions without extravasation in patients with ICH.

MATERIALS AND METHODS

CT was performed at admission and at 24 hours for 16 patients with ICH with/without contrast extravasation seen on CTA and PCCT. PCT-PS was measured at admission. The Wilcoxon rank sum test with a Bonferroni correction was used to compare PS values from the following regions of interest: 1) spot sign lesions only (9 foci), 2) PCL lesions only (9 foci), 3) hematoma excluding extravasation, 4) regions contralateral to extravasation, 5) hematoma in patients without extravasation, and 6) an area contralateral to that in 5. Additionally, hematoma expansion was determined at 24 hours defined by NCCT.

RESULTS

PS was 6.5 ± 1.60 mL · min(-1) × (100 g)(-1), 0.95 ± 0.39 mL · min(-1) × (100 g)(-1), 0.12 ± 0.39 mL · min(-1) × (100 g)(-1), 0.26 ± 0.09 mL · min(-1) × (100 g)(-1), 0.38 ± 0.26 mL · min(-1) × (100 g)(-1), and 0.09 ± 0.32 mL · min(-1) × (100 g)(-1) for the following: 1) spot sign lesions only (9 foci), 2) PCL lesions only (9 foci), 3) hematoma excluding extravasation, 4) regions contralateral to extravasation, 5) hematoma in patients without extravasation, and 6) an area contralateral to that in 5. PS values from spot sign lesions and PCL lesions were significantly different from each other and all other regions, respectively (P < .05). Hematoma volume increased from 34.1 ± 41.0 mL to 40.2 ± 46.1 mL in extravasation-positive patients and decreased from 19.8 ± 31.8 mL to 17.4 ± 27.3 mL in extravasation-negative patients.

CONCLUSIONS

The PCT-PS parameter measures a higher rate of contrast extravasation for CTA spot sign lesions compared with PCL lesions and hematoma. Early extravasation was associated with hematoma expansion.

Comparison of transnasal small-caliber vs. peroral conventional esophagogastroduodenoscopy for evaluating varices in unsedated cirrhotic patients

BACKGROUND AND STUDY AIMS

We aimed to evaluate the accuracy of transnasal small-caliber esophagogastroduodenoscopy (TNSC-EGD) compared with peroral conventional EGD (POC-EGD) for evaluating varices in unsedated patients with liver cirrhosis. The success rate, safety, endoscopist satisfaction, and patient tolerability of TNSC-EGD were also addressed.

PATIENTS AND METHODS

One hundred patients with liver cirrhosis participated in this randomized crossover trial, and 84 subjects completed both procedures. Of the 84 patients, 28 had marked bleeding diathesis (platelet count ≤ 50000/mm (3) and/or prothrombin time ≥ 1.7 INR). Endoscopists and patients answered questionnaires using a 100-mm visual analog scale about, respectively, their satisfaction and their tolerance of the procedure.

RESULTS

The success rate of TNSC-EGD was comparable to that of POC-EGD (96% vs. 99%). Nasal mucosal hemorrhages induced by TNSC-EGD occurred in 5 patients (6%), but were easily controlled. Compared to the POC-EGD reference test, diagnostic accuracies of TNSC-EGD for detecting esophageal varices, gastric varices, and red color signs were 98%, 98%, and 96%, respectively. Concordance rates on grading esophageal varices and gastric varices were excellent at 93% (κ  =  0.85) and 96% (κ  = 0.87). Endoscopist satisfaction was not significantly different between TNSC-EGD and POC-EGD, whereas patient tolerance of TNSC-EGD was significantly greater than that of POC-EGD (79.0 ± 14.4 vs. 69.5 ± 16.1; P  = 0.001).

CONCLUSION

TNSC-EGD without sedation was found to be feasible, safe, and accurate for evaluating esophageal varices, gastric varices, and red color signs in patients with cirrhosis - even in those with marked bleeding diathesis. Furthermore, it was significantly better tolerated by patients, without altering endoscopist satisfaction. Our findings indicate that TNSC-EGD without sedation might be viewed as a potential alternative to POC-EGD for evaluation of varices.

The Intracerebral Haemorrhage Acutely Decreasing Arterial Pressure Trial: ICH ADAPT

The majority of intracerebral haemorrhage patients present with markedly elevated blood pressure immediately after symptom onset. Management of blood pressure in the first 24 h is extremely controversial and lends itself to two competing rationales. There is some evidence that early treatment may improve outcome, potentially by reducing the rate of haematoma expansion. It is also possible that this will reduce cerebral blood flow and therefore exacerbate the cerebral injury, particularly in the region surrounding the haematoma. Only a trial that includes both randomisation of patients to two different blood pressure management strategies and actual measurement of cerebral blood flow can effectively address this pressing debate. This is the only unequivocal way to demonstrate the haemodynamic effects of rapid blood pressure reduction. The Intracerebral Haemorrhage Acutely Decreasing Arterial Pressure Trial is designed to test the hypothesis that blood pressure reduction does not result in significant or harmful changes in cerebral blood flow in acute intracerebral haemorrhage. Two hours after randomisation to a systolic blood pressure target of <150 or <180 mmHg, cerebral blood flow is measured using computed tomography perfusion, which is the primary end-point of the trial. A study of this type is critical to establishing the safety of early blood pressure treatment and is necessary for planning larger efficacy trials in a rational manner. This trial is registered with clinicaltrials.gov (NCT00963976).

Predicting postoperative FEV1 using spiral computed tomography

RATIONALE AND OBJECTIVES

Lung resection for primary bronchogenic carcinoma in the setting of chronic obstructive pulmonary disease often requires a detailed assessment of lung function to avoid perioperative complications and long-term disability. The aim of this study was to test the hypothesis that a novel technique of spiral computed tomographic (CT) subtraction imaging provides accuracy equal to the current standard of radioisotope perfusion scintigraphy in predicting postoperative lung function.

METHODS AND MATERIALS

Preoperative lung function, radioisotope perfusion scintigraphy, spiral CT subtraction imaging, and assessment of postoperative lung function were performed in 25 patients with surgically resectable primary bronchogenic carcinoma. Comparisons of predicted postoperative lung function between the two modalities and to true postoperative lung function were performed using Pearson's correlation and linear regression analysis.

RESULTS

Among the 25 patients enrolled in the study, there was a high degree of agreement between the predicted value of postoperative forced expiratory lung volume in 1 second (FEV(1)) generated on novel contrast CT subtraction imaging and that on radioisotope perfusion scintigraphy (r = 0.96, P < .001). Furthermore, there was a strong correlation between the predicted and actual postoperative FEV(1) values for both imaging modalities (r = 0.87, P < .001, and r = 0.88, P < .001, respectively), among the 14 patients completing the study protocol.

CONCLUSION

A novel technique of CT subtraction imaging is equally accurate at predicting postoperative lung function as radioisotope perfusion scintigraphy, which may obviate the need for additional nuclear imaging in the context of the preoperative assessment of resectable lung cancer in high-risk patients.

An evolutionarily conserved nested gene pair - Mab21 and Lrba/Nbea in metazoan

The embedding of one gene in another as a nested gene pair is a unique phenomenon of gene clustering in the metazoan genome. A gene-centric paralogous genomic sequence comparison strategy was used in this study to align these paralogous nested pairs, Mab21l2-Lrba and Mab21l1-Nbea, to identify the associated paralogous non-coding elements (pNEs) they shared. A majority of these pNEs in the Mab21l2-Lrba locus display tissue-specific enhancer activities recapitulating the expression profiles of Mab21l2 and Mab21l1. Since these enhancers are spread into the introns of Lrba, dissociation of the two genes will likely disrupt the function of at least one of them. Phylogenetic analysis of this complex locus in different species suggests that Mab21 was probably locked in the Lrba/Nbea intron in the ancestral metazoan species, in which the cis-elements uncovered in this study may act as a selective force to prevent the dissociation of this gene pair in vertebrates.

Magnetism of FePt surface alloys

The complex correlation of structure and magnetism in highly coercive monoatomic FePt surface alloys is studied using scanning tunneling microscopy, x-ray magnetic circular dichroism, and ab initio theory. Depending on the specific lateral atomic coordination of Fe either hard magnetic properties comparable to that of bulk FePt or complex noncollinear magnetism due to Dzyaloshinski-Moriya interactions are observed. Our calculations confirm the subtle dependence of the magnetic anisotropy and spin alignment on the local coordination and suggest that 3D stacking of Fe and Pt layers in bulk L1_{0} magnets is not essential to achieve high-anisotropy values.

Nonlinear time series analysis of ground-level ozone dynamics in Southern Taiwan

The ozone pollution at ground level in rural and urban areas has been a long-standing problem in the world. This paper focuses on estimating self-affined nature of nonlinearity of ground-level peak ozone time series, which is analyzed by two nonlinear fractal statistical methods, including R/S analysis and BDS test. To explore the underlying structure of ozone observations at ground level and improve the forecasting capacity in urban region, practical implementation was assessed by a case study via collecting and analyzing the monitoring data at Chaojhou and Zenwu in the Kaohsiung metropolitan region, Taiwan. Based on R/S analysis, the time series can be identified as persistent and long-memory processes with Hurst exponents of both about 0.75. In addition, the V statistics specifies possible fluctuation cycle lengths of 32, 170, and 420 day simultaneously. Such results are consistent with the regional meteorological conditions leading to help characterize the regional scale ozone behavioral trend. Furthermore, the BDS test results confirm a strong nonlinearity of both time series associated with these two cities. Yet in both cases, nonlinearity implies chaos. The R/S analysis and BDS test provide strong evidence for nonlinearity and fractality of ozone time series due to noisy chaos, and we could not rule out the possibility of deterministic chaos in tropospheric ozone system.

Relationship between gamma-glutamyltransferase and metabolic syndrome in a Korean population

AIMS

To investigate associations between gamma-glutamyltransferase (GGT) and components of metabolic syndrome (MS), insulin resistance and inflammatory markers in the Korean population.

METHODS

The 3508 subjects enrolled in this survey participated in the Korean Rural Genomic Cohort (KRGC) study. Written consent was obtained from the local ethical committee. Of these participants, 1437 were men (mean age 56.9 +/- 7.9 years) and 2071 were women (mean age 55.8 +/- 8.1 years). We measured GGT levels and various biochemical markers. To examine insulin resistance status, we used the homeostasis assessment method for insulin resistance (HOMA-IR). For inflammatory marker, we used C-reactive protein (CRP) levels.

RESULTS

Serum GGT levels were significantly higher in the MS group compared to the healthy patient group [23 (5-1403) vs. 19 (5-1920) IU/l; P = 0.01]. The prevalence of MS and adjusted relative risk were both significantly increased from the lowest to highest GGT quartiles; these results persisted after adjustments for multiple confounders. Positive correlations were established between GGT and HOMA-IR or CRP.

CONCLUSION

These results suggest that GGT levels may be a surrogate marker of insulin resistance, inflammation and MS.

The effects of botulinum toxin type A on muscle blood perfusion and metabolism

BACKGROUND

Botulinum toxin type A is approved by the U.S. Food and Drug Administration for the treatment of facial rhytides. However, the complete spectrum of action of botulinum toxin A has not yet been completely defined. Little is known about the metabolism of muscle after botulinum toxin A injection. This information may give insight into the additional effects botulinum toxin A may have on muscle. The authors assessed the influence of botulinum toxin A on the metabolism of muscle using dynamic investigative techniques.

METHODS

Twenty New Zealand White rabbits were divided into control, paralysis, and sham groups. Masseter muscle paralysis was achieved with botulinum toxin A. Dynamic computed tomographic and positron emission tomographic scans were obtained. Masseter muscle blood flow, blood volume, permeability surface, and mean transit time and glucose uptake were measured.

RESULTS

Eighteen animals completed the study. Masseter blood perfusion showed consistent results across all parameters. Blood flow, blood volume, and permeability surface were significantly increased at weeks 4 and 8 on the paralyzed side. Mean transit time at week 4 was decreased on the paralyzed side. Positron emission tomographic scans showed that injected muscles in the botulinum toxin A group tended to have increased glucose uptake compared with untreated muscles.

CONCLUSIONS

Botulinum toxin A injection increases muscle blood perfusion parameters and glucose uptake for a transient period. This increase is similar in duration to the known interval of botulinum toxin A-induced paralysis. These changes have been identified in a dynamic fashion and may represent changes in calcitonin gene-related peptide release.

CT perfusion-derived mean transit time predicts early mortality and delayed vasospasm after experimental subarachnoid hemorrhage

BACKGROUND AND PURPOSE

There are limited indicators available to predict cerebral vasospasm in patients with subarachnoid hemorrhage (SAH). The purpose of this study was to determine if CT perfusion-derived hemodynamic parameters are predictors of vasospasm severity and outcome after experimental SAH.

MATERIALS AND METHODS

SAH was induced in 25 New Zealand white rabbits. Cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were measured with CT perfusion before SAH, within 1 hour after SAH, and on days 2, 4, 7, 9, and 16 after SAH. Basilar artery diameter, measured with CT angiography and neurologic scoring, was also obtained on the same days. Differences between animals with moderate-severe delayed vasospasm (>/=24% basilar artery narrowing) and mild delayed vasospasm (<24% basilar artery narrowing) were investigated with repeated measures analysis of variance. Multiple linear regression analysis was used to investigate the relationship between CT perfusion parameters (CBF, CBV, MTT), basilar artery diameter, and neurologic score.

RESULTS

MTT increase <1 hour after SAH independently predicted mortality within 48 hours of SAH (P < .05). MTT and neurologic deficits were significantly greater with moderate-severe than with mild vasospasm (P < .05). MTT on day 2, but not CBF or CBV, was a significant predictor of subsequent moderate-severe delayed vasospasm (P < .05).

CONCLUSION

In the rabbit model of experimental SAH, the CT-derived hemodynamic parameter MTT on day 0 predicted early mortality, and MTT on day 2 predicted development of moderate-severe delayed vasospasm. MTT was also significantly correlated with arterial diameter and neurologic score.

Analysis of percutaneous transhepatic cholangioscopy-related complications and the risk factors for those complications

BACKGROUND AND STUDY AIMS

Percutaneous transhepatic cholangioscopy (PTC) is being increasingly used for patients with biliary tract diseases. The aim of this study was to assess the safety of this procedure, and we systematically analyzed PTC-related complications and the risk factors for those complications.

PATIENTS AND METHODS

A total of 364 patients who underwent PTC were included in the study. The initial diagnoses, the indications for PTC, the complications that occurred during the procedures, and the risk factors for these complications were retrospectively analyzed.

RESULTS

The overall incidence of complications was 12.9 % for percutaneous transhepatic biliary drainage (PTBD), 12.8 % for tract dilation, and 6.9 % for tract maturation. Complications developed in 58/848 PTC sessions (6.9 %). Cholangitis and bacteremia were associated with PTBD and tract dilation, catheter migration and blockage with tract maturation, and bile duct injury with PTC. Mild complications occurred in 80 patients (22.2 %) during the preparation stages and in 43 sessions (5.1 %) during the PTC itself. Severe complications, including severe hemobilia, hemoperitoneum, rupture of the sinus tract, and ductal injury developed in 17 patients (4.7 %) during the preparation period, and in 15 patients (4.1 %) during PTC. The overall incidence of severe complications along the entire course was 8.2 % (30/364 patients). No patient died or required surgery. Intraductal manipulations, such as electrohydraulic lithotripsy or balloon dilation, and the first session of PTC were risk factors for procedure-related complications.

CONCLUSIONS

PTC is a relatively safe and well-tolerated method for treating certain biliary tract diseases. Meticulous patient selection and a cooperative team approach are required in order to minimize the incidence of complications and to provide effective management.

The Effects of Masseter Muscle Paralysis on Facial Bone Growth

BACKGROUND

Understanding the effects of muscle function on facial bone growth may help us treat children with facial anomalies. Facial bone growth is known to be a result of both genetic and epigenetic influences. One of the main epigenetic factors controlling growth is thought to be muscle action. The purpose of this study was to establish a model of single facial muscle paralysis and to identify the effects masseter muscle paralysis has on mandible and zygoma growth.

METHODS

Twenty New Zealand white rabbits were divided into control, paralysis, and sham groups. Masseter muscle paralysis was achieved with botulinum toxin A (BTX). Computed tomographic and single-photon emission computed tomography (SPECT) scans and cephalometric measurements were performed. Masseter weights and mandible and zygoma volumes, shapes, and metabolism were measured.

RESULTS

Eighteen animals completed the study. Significant decreases in zygoma and mandible volumes with minimal changes in shape were seen on the paralyzed sides. SPECT showed a decrease in bone production in both zygomas and mandibles on the paralyzed sides.

CONCLUSIONS

An animal model has been created in which the effects of single muscle paralysis on bone growth can be studied. Masseter muscle function may be responsible in maintaining mandible and zygoma volume by controlling bone production. Masseter function alone has less influence on mandible and zygoma shape.

Functional CT for Quantifying Tumor Perfusion in Antiangiogenic Therapy in a Rat Model

PURPOSE

To determine the histologic basis of perfusion parameters measured at functional computed tomography (CT) and to examine the relationship between changes in perfusion and changes in histologic parameters after antiangiogenic therapy in a rat model.

MATERIALS AND METHODS

This study had institutional animal care and use committee approval. Among 20 Fischer rats with implanted FN13762 tumors in the liver, 10 were treated with SU5416, a tyrosine kinase inhibitor of vascular endothelial growth factor receptor, and 10 were treated with the diluent only as control rats. Six rats chosen at random from each group underwent functional CT for the measurement of tumor blood flow, blood volume, mean transit time, and permeability-surface area product. Tumor tissue slides corresponding to functional CT sections were examined to measure tumor microvascular density, number of luminal vessels, vascular perimeter, and vascular area. Two-tailed Student t testing was used to determine differences in growth, numbers of metastases to major organs, vascularity, and perfusion between SU5416-treated and control tumors. Pearson correlation coefficients were used to investigate relationships between vascular parameters.

RESULTS

Mean tumor volume and number of metastases, respectively, were lower in SU5416-treated rats than in control rats (1580 mm3 +/- 830 [standard deviation] vs 2330 mm3 +/- 960 and 22.4 +/- 11.0 vs 35.2 +/- 17.3); however, these differences were not significant (P = .084 and P = .079). Mean tumor microvascular density was significantly lower in SU5416-treated rats than in control rats (6.4 vessels per field +/- 4.6 vs 17.2 vessels per field +/- 7.5, P < .001); however, vessel perimeter and vessel area, respectively, were significantly larger in treated rats than in control rats (470 microm per field +/- 320 vs 360 microm per field +/- 270, P = .02; and 4010 microm2 per field +/- 2990 vs 2230 microm2 per field +/- 1750, P = .001). Significant correlations were observed between microvascular density and vessel perimeter and area (r = 0.59 and r = 0.25, respectively; P < .01 for both) in SU5416-treated tumors but not control tumors. Blood flow, blood volume, and permeability-surface area product at functional CT were significantly higher in SU5416-treated tumors than in control tumors (P < .001 for all).

CONCLUSION

These results validate the idea that functional CT can help quantify the perfusion function of mature vessels but not changes in microvessel density in antiangiogenic therapy.

Effects of tautomycetin on proliferation and fibronectin secretion in vascular smooth muscle cells and glomerular mesangial cells

Tautomycetin (TMC), a newly developed immunosuppressive agent, induces T-lymphocyte apoptosis through the inhibition of tyrosine kinase and protein phosphatase 1. We examined the effects of TMC on platelet-derived growth factor (PDGF)-induced proliferation and extracellular matrix synthesis in cultured vascular smooth muscle cells (VSMCs) and mesangial cells (MCs) of Sprague-Dawley rats, and investigated the molecular mechanisms involved. Different concentrations of TMC were administered 1 hour before the addition of 10 ng/mL PDGF into the growth-arrested and synchronized cells. Cell proliferation was assessed by methylthiazoletetrazolium (MTT) assay, fibronectin secretion, and the activation of Akt, ERK, and p38 MAPK by Western blot analysis. PDGF increased cell proliferation, fibronectin secretion, and the activation of Akt, ERK, and p38 MAPK in both VSMCs and MCs. In both cultured cells, TMC at >1 mug/mL significantly reduced basal MTT. TMC at 100 ng/mL significantly decreased the PDGF-induced VSMC and MC proliferation. However, fibronectin secretion and the activation of Akt, ERK, and p38 MAPK were not affected by this nontoxic concentration of TMC. The present data demonstrate that low-dose TMC reduced PDGF-induced VSMC and MC proliferation without affecting the fibronectin secretion and cellular kinase activation.

Assessment of the tumor microenvironment in cervix cancer using dynamic contrast enhanced CT, interstitial fluid pressure and oxygen measurements

PURPOSE

Interstitial fluid pressure (IFP) and oxygen (pO(2)) measurements are prognostic factors in cervical cancer. The purpose of this study was to determine the relationship between IFP and oxygenation and parameters derived from dynamic contrast-enhanced computed tomography (DCE-CT).

METHODS AND MATERIALS

Dynamic contrast-enhanced computed tomography was performed in 32 patients with cervical cancer before radiation therapy. Images were acquired during intravenous contrast injection at 1 per s for 120 s and 1 per 15 s for 60 s. DCE-CT was analyzed using CT Perfusion 3 software (GE Medical Systems) to derive tumor blood flow (BF), permeability surface area product, blood volume, and mean transit time. Further analysis was performed to obtain relative peak enhancement, residual enhancement at 3 min after contrast injection (RE), time to peak and initial slope. Nodal status and tumor size were assessed with MRI. From in vivo IFP (n = 31) and pO(2) (n = 31) tumor measurements median pO(2) (mO(2)), percentage measurements less than 5 mm Hg (HP5) and mean IFP values were calculated.

RESULTS

There was a positive correlation between BF and mO(2) (r = 0.47, p = 0.007) and between RE and HP5 (r = 0.39, p = 0.03). There was no correlation between IFP and DCE-CT parameters.

CONCLUSION

There is a moderately positive, correlation between tumor oxygenation and BF as well as RE and HP5. Further study is required to determine if DCE-CT parameters are useful predictors of tumor behavior in cervical cancer.

Hopelessness in Chinese adolescents in Hong Kong: demographic and family correlates

Chinese secondary school students (N = 3,017) responded to measures of adolescent hopelessness, perceived parental behavioral control (indexed by parental knowledge, expectation, monitoring, discipline, and demandingness, as well as Chinese parental control attributes), parental psychological control, and parent-child relational qualities (satisfaction with parental control, child's readiness to communicate with the parents and perceived mutual trust). Results showed that roughly one-fifth of Chinese adolescents displayed signs of hopelessness and adolescent hopelessness was related to adolescent age and gender as well as parental education and marital status. Although parental behavioral control was negatively related to adolescent hopelessness, parental psychological control was positively associated with adolescent hopelessness. Participants perceived parent-child relational qualities to be better showed lower levels of hopelessness.

The effect of varying user-selected input parameters on quantitative values in CT perfusion maps

RATIONALE AND OBJECTIVES

Deconvolution-based software can be used to calculate quantitative maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) from first-pass computed tomography perfusion (CTP) datasets. The application of this software requires the user to select multiple input variables. The purpose of this study was to investigate the degree to which both major and minor variations of these user-defined inputs would affect the final quantitative values of CBF, CBV, and MTT.

MATERIALS AND METHODS

A neuroradiologist constructed CBF, CBV, and MTT maps using standard methodology with commercially available software (GE Functool Version 1.9s) from CTP datasets of three acute stroke patients. Each map was reconstructed multiple times by systematically and independently varying the following parameters: postenhancement and preenhancement cutoff values, arterial and venous region-of-interest (ROI) placement, and arterial and venous ROI size. The resulting quantitative CTP values were compared using identical ROIs placed at the infarct core.

RESULTS

Major variations of either arterial ROI placement or arterial and venous ROI size had no significant effect on the mean CBF, CBV, and MTT values at the infarct core (p > .05). Even minor variations, however, in the choice of venous ROI placement or in pre- and postenhancement cutoff values significantly altered the quantitative values for each of the CTP maps, by as much as threefold.

CONCLUSION

Even minor variations of user-defined inputs can significantly influence the quantitative, deconvolution-based CTP map values of acute stroke patients. Although quantitation was robust to the choice of arterial ROI placement and arterial or venous ROI size, it was strongly dependent on the choice of venous ROI location and pre- and postenhancement cut-off values. Awareness of these results by clinicians may be important in the creation of quantitatively accurate CTP maps.

Symptomatic giant Müllerian duct cyst in an infant: radiographic and CT findings

We report an unusual case of Müllerian duct cyst in an 8-month-old infant who presented with frequent vomiting and recurrent urinary tract infections. Computed tomography showed a midline giant cyst in the pelvic floor. Delayed enhanced computed tomography demonstrated contrast filling of the cyst, indicating a communication with the urotract. Subsequent cystourethrogram and surgery confirmed a giant Müllerian duct cyst.

Identity and conservation of mating type genes in geographically diverse isolates of Phaeosphaeria nodorum

Mating type idiomorphs (MAT1-1 and MAT1-2) were identified from the heterothallic loculoascomycete Phaeosphaeria nodorum (wheat biotype) using DNA from a pair of isolates from Poland and Georgia, USA that are known to mate. MAT predicted proteins of P. nodorum are similar in sequence and in phylogenetic relationship to those described for other loculoascomycetes such as Cochliobolus spp., Alternaria alternata, and Didymella zeae-maydis. The organization of the MAT locus of the P. nodorum differs from these species in that its idiomorph begins within an adjacent upstream conserved ORF of unknown function. MAT-specific primers were used to identify isolates of both mating types in field populations, demonstrating that an absence of either mating type is not the reason that the teleomorph has not been found in New York. Portions of MAT1-1 and MAT1-2 were sequenced from geographically diverse isolates, including those from regions where the teleomorph has been reported. MAT was highly conserved and no significant differences in sequence were found.

Effects of cryopreservation on meiotic spindles of oocytes and its dynamics after thawing: clinical implications in oocyte freezing--a review article

Embryo freezing has been a successful practice, but oocyte cryopreservation formerly achieved poorer results. This was mainly due to low rates of survival, fertilization, and development. The major dissimilarities for oocytes to embryos are the character of the plasma membrane, the presence of cortical granules, at the metaphase of meiosis II with the spindle system. In addition, the oocytes must be fertilized by sperm at the appropriate time. To improve the survival rate, a refined slow freezing method with increased sucrose concentration would dehydrate oocytes more sufficiently. Vitrification is another approach to prevent ice crystal formation. Intracytoplasmic sperm injection is used to overcome possible zona hardening from the release of cortical granules. The microtubules of meiotic spindles are vulnerable to the thermal changes and would depolymerize. Cryopreserved oocytes exhibited serious disturbances of the microtubules immediately after thawing. Fertilization of oocytes with disorganized spindles could lead to chromosomal aneuploidy, digyny, and arrest of cleavage. After incubation, the microtubules would repolymerize in a time-dependent way. Normal fertilization and development of cryopreserved oocytes improved after appropriate incubation and timing of insemination, compatible with recovery of the spindles. With the improvement of survival, fertilization, and cleavage, oocyte cryopreservation would gain an imperative role.