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.

The use of Lutetium-177 PSMA radioligand therapy with high dose rate brachytherapy for locally recurrent prostate cancer after previous definitive radiation therapy: a randomized, single-institution, phase I/II study (ROADSTER)

BACKGROUND

Isolated local failure (ILF) can occur in patients who initially receive definitive radiation therapy for prostate cancer. Salvage therapy for ILF includes high dose rate (HDR) brachytherapy. Prostate Specific Membrane Antigen (PSMA) Positron Emission Tomography (PET) can accurately detect ILF and can exclude extraprostatic disease. Lutetium-177 PSMA Radioligand Therapy (RLT) is a novel treatment for prostate cancer that can target prostate cancer accurately, while sparing radiation dose to normal tissues.

METHODS

ROADSTER is a phase I/II randomized, single-institution study. Patients with an ILF of prostate cancer after definitive initial radiation therapy are eligible. The ILF will be confirmed with biopsy, magnetic resonance imaging (MRI) and PSMA PET. Patients will be randomized between HDR brachytherapy in two fractions (a standard of care salvage treatment at our institution) (cohort 1) or one treatment of intravenous Lutetium-177 PSMA RLT, followed by one fraction of HDR brachytherapy (cohort 2). The primary endpoints for the phase I portion of the study (n = 12) will be feasibility, defined as 10 or more patients completing the study protocol within 24 months of study activation; and safety, defined as zero or one patients in cohort 2 experiencing grade 3 or higher toxicity in the first 6 months post-treatment. If feasibility and safety are achieved, the study will expand to a phase II study (n = 30 total) where preliminary efficacy data will be evaluated. Secondary endpoints include changes in prostate specific antigen levels, acute toxicity, changes in quality of life, and changes in translational biomarkers. Translational endpoints will include interrogation of blood, urine, and tissue for markers of DNA damage and immune activation with each treatment.

DISCUSSION

ROADSTER explores a novel salvage therapy for ILF after primary radiotherapy with combined Lutetium-177 PSMA RLT and HDR brachytherapy. The randomized phase I/II design will provide a contemporaneous patient population treated with HDR alone to facilitate assessment of feasibility, tolerability, and biologic effects of this novel therapy.

TRIAL REGISTRATION

NCT05230251 (ClinicalTrials.gov).

Snapshots Quiz

A 72-year old man presented with recurrent attacks of melaena and severe anemia Oeesophago-Gastro-Duodenoscopy and Colonoscopy were normal. A contrast enhanced abdominal computed tomography scan showed extravasation of contrast medium in the left abdomen. Ongoing bleeding necessitated surgical intervention. At surgery a 1.5☓2.0cm lesion in the proximal jejunum, 10cm distal to the Treitz ligament was found. What is the diagnosis?

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.

Designing Triple Adult Liver Grafts From an Ideal Deceased Liver

Splitting deceased donor livers and creating 3 grafts from a whole liver may be feasible and shorten the waiting time for organ donation in patients with high mortality rates. We hypothesized that it might be reasonable to procure 3 grafts for donation from one deceased donor liver by splitting the liver into left (segment II, III, IV), right anterior (segment V, VIII), and right posterior lobes (segment VI, VII) for liver transplantation according to the portal system trifurcated variations. We designed the right anterior branch with the main portal trunk and middle hepatic artery to become inflow of right anterior lobe, the left portal vein and left hepatic artery to become the inflow of left lobe and right posterior branch, and right hepatic artery to become the inflow of right posterior lobe. We retrospectively reviewed the volumetric computed tomography and magnetic resonance cholangiopancreatography of 153 liver donors. The hepatic and portal veins, hepatic artery, and biliary system were reorganized and classified. The volumetric proportions of the liver grafts were measured. Trifurcation of the portal vein variation was found in approximately 13.7% of portal systemic variations. The left lobe accounted for 29.18% of the total liver volume, the right anterior lobe, 35.22%, and the right posterior lobe, 35.6%. We validated this principle by dissecting the explanted liver and identified the triple grafts' weights, percentages, vessels, and biliary ducts system. The splitting of deceased donor livers into 3 split liver grafts for use in liver transplantation surgery can be clinically useful.

Prospective Multicenter Study of Changes in MTT after Aneurysmal SAH and Relationship to Delayed Cerebral Ischemia in Patients with Good- and Poor-Grade Admission Status

BACKGROUND AND PURPOSE

Patients with aneurysmal SAH and good clinical status at admission are considered at a lower risk for delayed cerebral ischemia. Prolonged MTT may be associated with an increased risk. It is unclear whether this is dependent on clinical status. Our purpose was to determine whether increased MTT within 3 days of aneurysmal SAH compared with baseline is associated with a higher risk of delayed cerebral ischemia in patients with good (World Federation of Neurosurgical Societies I-III) versus poor (World Federation of Neurosurgical Societies IV-V) admission status.

MATERIALS AND METHODS

This prolonged MTT was a multicenter, prospective cohort investigation of 87 patients with aneurysmal SAH. MTT was measured at admission before aneurysm treatment (MTT1) and following repair (MTT2) within 3 days of admission; MTT_diff was calculated as the difference between MTT2 and MTT1. Changes in MTT across time were assessed with repeated measures analyses. Risk of delayed cerebral ischemia or death was determined with multivariate logistic regression analysis.

RESULTS

In patients with a good grade (n = 49), MTT was prolonged in patients who developed delayed cerebral ischemia, with MTT_diff significantly greater (0.82 ± 1.5) compared with those who did not develop delayed cerebral ischemia (-0.14 ± 0.98) (P = .03). Prolonged MTT was associated with a significantly higher risk of delayed cerebral ischemia or death (OR = 3.1; 95% CI, 1.3-7.4; P = .014) on multivariate analysis. In patients with poor grades (n = 38), MTT_diff was not greater in patients who developed delayed cerebral ischemia; MTT1 was significantly prolonged compared with patients with a good grade.

CONCLUSIONS

Patients in good clinical condition following aneurysmal SAH but with increasing MTT in the first few days after aneurysmal SAH are at high risk of delayed cerebral ischemia and warrant close clinical monitoring.

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.

Permeability surface area product analysis in malignant brain edema prediction - A pilot study

BACKGROUND AND PURPOSE

Using an extended CT perfusion acquisition (150s), we sought to determine the association between perfusion parameters and malignant edema after ischemic stroke.

METHODS

Patients (from prospective study PROVE-IT, NCT02184936) with terminal internal carotid artery±proximal middle cerebral occlusion were involved. CTA was assessed for clot location and status of leptomeningeal collaterals. The following CTP parameters were calculated within the ischemic territory and contralaterally: permeability surface area product (PS), cerebral blood flow (CBF) and cerebral blood volume (CBV). PS was calculated using the adiabatic approximation to the Johnson and Wilson model. Outcome was evaluated by midline shift and infarction volume on follow-up imaging.

RESULTS

Of 200 patients enrolled, 7 patients (3.5%) had midline shift≥5mm (2 excluded for poor-quality scans). Five patients with midline shift and 5 matched controls were analysed. There was no significant difference in mean PS, CBF and CBV within the ischemic territory between the two groups. A CBV threshold of 1.7ml/100g had the highest AUC=0.72, 95% CI=0.54-0.90 for early midline shift prediction, sensitivity and specificity were 0.83 and 0.67 respectively.

CONCLUSION

Our preliminary results did not show significant differences in permeability surface area analysis if analysed for complete ischemic region. CBV parameter had the highest accuracy and there was a trend for the mean PS values for midline shift prediction.

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.

Wood Preference of Reticulitermes virginicus (Blattodea: Rhinotermitidae) Using No-, Two-, and Four-Choice Designs and Seven Different Measures of Wood Consumption

Three hundred Reticulitermes virginicus (Banks) workers were exposed to three 1-cm3 wood blocks of either Quercus sp. (Red Oak), Populus sp. (Poplar), Pinus sp. (Pine), or Sequoia sp. (Redwood) placed into one of the three bioassay designs (no-, two-, and four-choice) for 21 d. Termite wood consumption was measured by wood weight loss, resistance class, and visual rating. Wood consumption rates were determined using four formulas in addition to two standardized visual rating scales (American Society for Testing and Materials [ASTM] and American Wood Protection Association [AWPA]) and a preference ranking obtained for each measure. The wood consumption formula, rating scale, and preference rankings were compared by bioassay design. The overall preference ranking of the four wood types as determined by the combination of all three designs was—1) Pine, 2) Red Oak, 3) Redwood, and 4) Poplar. Results indicate that bioassay design influenced both wood consumption and preference rankings. A no-choice design can determine aversion; a four-choice design the most preferred wood; and a two-choice design can illuminate the fine details of comparative preference. The different formulas employed for calculation of consumption rate influenced preference ranking in the no- and four-choice designs but not the two-choice design.

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.

Randomized phase II study of axitinib versus placebo plus best supportive care in second-line treatment of advanced hepatocellular carcinoma

BACKGROUND

The efficacy and safety of axitinib, a potent and selective vascular endothelial growth factor receptors 1-3 inhibitor, combined with best supportive care (BSC) was evaluated in a global, randomized, placebo-controlled phase II trial in patients with locally advanced or metastatic hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Patients with HCC and Child-Pugh Class A who progressed on or were intolerant to one prior antiangiogenic therapy were stratified by tumour invasion (presence/absence of extrahepatic spread and/or vascular invasion) and region (Asian/non-Asian) and randomized (2:1) to axitinib/BSC (starting dose 5 mg twice-daily) or placebo/BSC. The primary end point was overall survival (OS).

RESULTS

The estimated hazard ratio for OS was 0.907 [95% confidence interval (CI) 0.646-1.274; one-sided stratified P = 0.287] for axitinib/BSC (n = 134) versus placebo/BSC (n = 68), with the median (95% CI) of 12.7 (10.2-14.9) versus 9.7 (5.9-11.8) months, respectively. Results of prespecified subgroup analyses in Asian versus non-Asian patients or presence versus absence of tumour invasion were consistent with the overall population. Improvements favouring axitinib/BSC (P < 0.01) were observed in secondary efficacy end point analyses [progression-free survival (PFS), time to tumour progression (TTP), and clinical benefit rate (CBR)], and were retained among Asian patients in the prespecified subgroup analyses. Overall response rate did not differ significantly between treatments and patient-reported outcomes favoured placebo/BSC. Most common all-causality adverse events with axitinib/BSC were diarrhoea (54%), hypertension (54%), and decreased appetite (47%). Baseline serum analyses identified potential new prognostic (interleukin-6, E-selectin, interleukin-8, angiopoietin-2, migration inhibitory factor, and c-MET) or predictive (E-selectin and stromal-derived factor-1) factors for survival.

CONCLUSIONS

Axitinib/BSC did not improve OS over placebo/BSC in the overall population or in stratification subgroups. However, axitinib/BSC resulted in significantly longer PFS and TTP and higher CBR, with acceptable toxicity in patients with advanced HCC.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01210495.

Dissecting alternative splicing in the formation of Miltenberger glycophorin subtype III (GYP.Mur)

BACKGROUND AND OBJECTIVES

Miltenberger subtype III (Mi.III, GP.Mur) is one of the most important red cell phenotypes in the fields of transfusion in South-East Asia. GP.Mur is believed to evolve from homologous gene recombination events between glycophorin A (GYPA) and glycophorin B (GYPB). GYP.Mur differs from GYPB in only seven nucleotides dispersed near the region of 3' exon 3 of GYP.Mur. The goal of this study was to dissect how these nucleotide variants affected splicing of exon 3.

MATERIALS AND METHODS

We first designed two minigene constructs: one containing GYP.Mur from exon 2 to exon 4 and the other containing GYPB in the same region. To test how these nucleotide variations between GYP.Mur and GYPB affected the splicing, a repertoire of the GYP.Mur-like minigene constructs with different point mutations were created. These minigene variants were evaluated for their abilities to induce splicing of exon 3 using a heterologous expression system.

RESULTS

(1) GYP.Mur minigene expressed exons 2, 3 and 4, whereas GYPB minigene expressed only exon 2 and exon 4. (2) The single nucleotide alteration at the position of the 5' splice site of glycophorin intron 3 reversed the splicing decision. (3) The nucleotide variations between GYP.Mur and GYPB other than that at the 5' splice site showed very little or no effect on splicing of exon 3.

CONCLUSION

Splicing of the glycophorin B-A-B hybrids (GYP.Mur and GYP.BUN) and unsplicing of GYPB follow the GU-AG rule strictly.

The use of Taqman genotyping assays for rapid confirmation of β-thalassaemia mutations in the Malays: accurate diagnosis with low DNA concentrations

INTRODUCTION

In Malaysia, β-thalassaemia is a common inherited blood disorder in haemoglobin synthesis with a carrier rate of 4.5%. Currently, PCR-incorporating techniques such as amplification refractory mutation system (ARMS) or reverse dot blot hybridization (RDBH) are used in β-thalassaemia mutation detection. ARMS allows single-mutation identification using two reactions, one for wild type and another for mutant alleles. RDBH requires probe immobilization and optimization of hybridization and washing temperatures which is time consuming. The aim of our study was to investigate whether β-thalassaemia mutations can be identified in samples with low DNA concentrations.

METHODS

Genotype identification of common β-thalassaemia mutations in Malays was carried out using Taqman genotyping assays.

RESULTS

Results show that the Taqman assays allow mutation detection with DNA template concentrations as low as 2-100 ng. In addition, consistent reproducibility was observed in the Taqman assays when repeated eight times and at different time intervals.

CONCLUSION

The developed sensitive Taqman assays allow molecular characterization of β-thalassaemia mutations in samples with low DNA concentrations. The Taqman genotyping assays have potential as a diagnostic tool for foetal blood, chorionic villi or pre-implantation genetic diagnosis where DNA is limited and precious.

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.

Kinetic model optimization for characterizing tumour physiology by dynamic contrast-enhanced near-infrared spectroscopy

Dynamic contrast-enhanced (DCE) methods are widely used with magnetic resonance imaging and computed tomography to assess the vascular characteristics of tumours since these properties can affect the response to radiotherapy and chemotherapy. In contrast, there have been far fewer studies using optical-based applications despite the advantages of low cost and safety. This study investigated an appropriate kinetic model for optical applications to characterize tumour haemodynamics (blood flow, F, blood volume, V(b), and vascular heterogeneity) and vascular leakage (permeability surface-area product, PS). DCE data were acquired with two dyes, indocyanine green (ICG) and 800 CW carboxylate (IRD(cbx)), from a human colon tumour xenograph model in rats. Due to the smaller molecular weight of IRD(cbx) (1166 Da) compared to albumin-bound ICG (67 kDa), PS of IRD(cbx) was significantly larger; however, no significant differences in F and V(b) were found between the dyes as expected. Error analysis demonstrated that all parameters could be estimated with an uncertainty less than 5% due to the high temporal resolution and signal-to-noise ratio of the optical measurements. The next step is to adapt this approach to optical imaging to generate haemodynamics and permeability maps, which should enhance the clinical interest in optics for treatment monitoring.

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.

Fulminant Type 1 diabetes in a pregnant woman as an initial manifestation of the insulin autoimmune syndrome

Fulminant Type 1 diabetes is a subtype of Type 1 diabetes characterized by (1) abrupt onset of diabetes, (2) very short duration of hyperglycaemia with mildly elevated HbA(1c) (< 69 mmol/mol, 8.5%), (3) rapid progression to diabetic ketoacidosis, (4) very low C-peptide level, and (5) often associated with elevated serum pancreatic enzymes, and absence of diabetes-related autoantibodies. We encountered a case of fulminant Type 1 diabetes that developed with an initial manifestation of the insulin autoimmune syndrome and rapidly progressed to diabetic ketoacidosis during pregnancy. A 31-year-old Korean woman presented with recurrent sudden onset of sweating and change of consciousness during sleep at 19 weeks gestation. During a 72-h fasting test, hypoglycaemia (1.72 mmol/l) occurred at 4 h after the start of the test. At that time, there was a high insulin level (370.2 μU/ml), a paradoxically low C-peptide level (0.01 nmol/l) and a positive insulin autoantibody test. An oral glucose tolerance test revealed postprandial hyperglycaemia. She was initially diagnosed as the insulin autoimmune syndrome. On the day 5 of admission, she developed diabetic ketoacidosis. Her HbA(1c) was 62 mmol/mol (7.8%). The rapid progression of diabetic ketoacidosis altered the diagnosis to fulminant Type 1 diabetes. This case differed from typical fulminant Type 1 diabetes because it presented with hypoglycaemia, and positive insulin and anti-phospholipid antibody tests. Her HLA typing was HLA-DQA1*0302, 0501, HLA-DRB1*0301 (DR3), 0901(DR9). Her glucose level was subsequently very well controlled with multiple insulin injections and she successfully delivered a healthy baby.

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.

Identifying LRRC16B as an oncofetal gene with transforming enhancing capability using a combined bioinformatics and experimental approach

Oncofetal genes are expressed in embryos or fetuses, are downregulated or undetectable in adult tissues, and then re-expressed in tumors. Known oncofetal genes, such as AFP, GCB, FGF18, IMP-1 and SOX1, often have important clinical applications or pivotal biological functions. To find new oncofetal-like genes, we used the public information of expressed sequence tags to systematically analyze gene expression patterns and identified a novel oncofetal-like gene, LRRC16B. It increased the proliferation, anchorage-independent growth and tumorigenesis of transformed cells in xenografts, possibly through its effects on cyclin B1 protein levels. These findings exemplify the feasibility of using bioinformatics to find new oncofetal-like genes and suggest that more genes with important functional roles will be uncovered in the candidate gene list.

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.

Theoretic basis and technical implementations of CT perfusion in acute ischemic stroke, part 2: technical implementations

CT perfusion (CTP) is a functional imaging technique that provides important information about capillary-level hemodynamics of the brain parenchyma and is a natural complement to the strengths of unenhanced CT and CT angiography in the evaluation of acute stroke, vasospasm, and other neurovascular disorders. CTP is critical in determining the extent of irreversibly infarcted brain tissue (infarct "core") and the severely ischemic but potentially salvageable tissue ("penumbra"). This is achieved by generating parametric maps of cerebral blood flow, cerebral blood volume, and mean transit time.

Theoretic basis and technical implementations of CT perfusion in acute ischemic stroke, part 1: Theoretic basis

CT perfusion (CTP) is a functional imaging technique that provides important information about capillary-level hemodynamics of the brain parenchyma and is a natural complement to the strengths of unenhanced CT and CT angiography in the evaluation of acute stroke, vasospasm, and other neurovascular disorders. CTP is critical in determining the extent of irreversibly infarcted brain tissue (infarct "core") and the severely ischemic but potentially salvageable tissue ("penumbra"). This is achieved by generating parametric maps of cerebral blood flow, cerebral blood volume, and mean transit time.

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.

Surgical management and clinical outcome of gastrointestinal stromal tumor of the colon and rectum

BACKGROUND

A standardized treatment for gastrointestinal stromal tumors (GIST) of the colon and rectum has not been clearly established. The objective of this study is to examine our experience in patients with colorectal GISTs and review the appropriate surgical management.

METHODS

The medical records of patients with colorectal GIST treated in our institution between 1995 and 2005 were reviewed. The malignant potential of the GIST was assessed with the current consensus criteria defined by the National Institutes of Health. Clinical parameters were also evaluated to determine prognostic factors.

RESULTS

There were 10 male and 7 female patients, with a median age of 64 years (range: 19 - 84). Bloody stool and abdominal pain were the most commonly reported symptoms in colorectal GISTs. There were 7 colonic GISTs and 10 rectal GISTs. Sixteen patients underwent surgery with a margin of negative resection including 12 radical surgical resections, 3 transanal wide excisions, and one colonoscopic excision. Pathological results revealed a high risk in 8 patients (47.1 %), an intermediate risk in 4 (23.5 %), a low risk in 3 (17.6 %), and a very low risk in 2 (11.8 %). Three patients (3 / 16, 18.6 %) developed disease relapse after primary radical resection. All the three patients were high-risk rectal GISTs, accounting for 42.9 % (3 / 7) in the high-risk group. The median time to disease relapse was 15.7 months (range: 6 - 24). Cox regression analysis showed that variables including age, gender, and tumor size were not presenting statistically significant differences between groups of relapse and non-relapse patients.

CONCLUSION

Non-high-risk colorectal GISTs bear a good prognosis after margin-negative surgery. Transanal wide excision for non-high-risk GISTs is mandatory if a complete resection can be performed. Abdominoperineal resection would be preserved only in patients with high risk or large non-high-risk lower rectal GISTs. The high-risk group has high incidence of relapse even though a complete resection was achieved. Adjuvant therapy with a tyrosine kinase inhibitor would be beneficial to these patients.

CT perfusion quantification of small-vessel ischemic severity

BACKGROUND AND PURPOSE

Cerebral blood flow (CBF) abnormalities are previously demonstrated in white matter disease. A gradation of change may exist between patients with mild and more severe white matter disease. An association between blood brain barrier dysfunction, increasing age and white matter disease is also suggested. The purpose of this study was to quantify and correlate white matter disease severity and CT perfusion (CTP)-derived CBF and to determine whether permeability surface abnormality increases with white matter disease severity.

MATERIALS AND METHODS

One hundred twenty patients with strokelike symptoms underwent CTP and MR imaging. Of these, 35 patients (15 women, 20 men; age, 66 +/- 15.7 years) with rapidly resolving symptoms and normal imaging characteristics consistent with transient ischemic attack were retrospectively reviewed and constituted the study cohort. Two blinded neurologists rated white matter severity, assigning age-related white matter change (ARWMC) scores. Patients were dichotomized a priori into mild and moderate-to-severe. CBF, cerebral blood volume (CBV), mean transit time (MTT), and permeability surface product maps were calculated for periventricular and subcortical white matter regions and average white and gray matter. Associations with white matter severity were tested by uni- and multivariate logistic regression analyses. Receiver operating characteristic analysis was performed.

RESULTS

White matter disease was mild in 26 patients and moderate-to-severe in 9. Age was associated with increased likelihood of having moderate-to-severe white matter disease (P = .02). ARWMC correlated with subcortical (r = -0.50, P < .001) and average CBF (r = -0.55, P < .001). White matter severity was associated with subcortical (P = .03) and average (P = .03) white matter CBF, with a trend toward periventricular white matter CBF (P = .05). Uni- and multivariate analysis controlling for the confounding effect of age demonstrated significant association between white matter severity and subcortical (P = .032) white matter CBF. Area under the curve was 0.82. No permeability surface abnormality was found.

CONCLUSIONS

CTP-derived subcortical white matter CBF is independently associated with white matter disease severity.

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.

Prevalence of antibody reaction with cercopithecine herpesvirus 1 antigen in Macaca cyclopis, Macaca fascicularis, and Papio anubis in Taiwan

BACKGROUND AND METHODS

A total of 284 non-human primate sera were collected between December 2004 and September 2005 and tested by a commercially available dot immunobinding assay for the antibodies to cercopithecine herpesvirus 1, an alphaherpesvirus with high mortality for infected humans.

RESULTS

Seropositive rates were 58% among non-human primates from animal shelters and 38% among those from zoos and academic institutes. Positive reactors were found in three species, the Formosan macaque (Macaca cyclopis; 57%), the cynomolgus macaque (Macaca fascicularis; 11%) and the olive baboon (Papio anubis; 68%).

CONCLUSIONS

Our results showed that natural infection by cercopithecine herpesvirus 1 in Formosan macaques was highly prevalent, and to a certain extent reflected the situation of the wild populations in Taiwan. The findings raised the issues of zoonotic public health and the occupational health of primate workers. High positive rate in olive baboons was also found, although, it cannot be ruled out that the positivity was due to cross-reactivity between cercopithecine herpesvirus 1 and other herpesviruses.

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.