Wafer Bonding for Soi

Bonding of 3 and 4 in. oxidized silicon wafers was investigated for SOI applications. The bonding was achieved by using a surface treatment procedure compatible with VLSI processing and by heating in an inert atmosphere a pair of wafers which had been contacted face-to-face. A quantitative method for the evaluation of the surface energy of the bond based on crack propagation was developed. The bond strength was found to increase with the bonding temperature from about 60-85 erg/cm2 at room temperature to ⋍2200 erg/cm2 at 1405°C, in good agreement with the surface energy of bulk quartz. The strength was essentially independent of the bond time for up to 1100°C. Electrical properties of the wet-oxide-to-wet-oxide bond were tested using MOS capacitors. The results were consistent with a negative interface charge density of approximately 1011cm−2 at the bond. A double etch-back procedure was used to thin the device wafer to the desired thickness within *20 nm across a 3in. wafer. The density of threading dislocations in the remaining silicon layer was smaller than 103 cm−3, and the residual dopant concentration less than 5×l015cm−3, both remnants of the etchstop layer. A discussion of the bonding mechanism will be presented.

The effect of a Clark twin block on mandibular motion: a case report

AIMS

To investigate mandibular motion in six degrees of freedom before, during and after twin block treatment in one individual.

METHODS

The appliance was worn for eight months, and motion recordings, using a 12-camera opto-electric system, were captured prior to placement of a twin block appliance and 2, 4, 14 and 52 weeks after insertion.

RESULTS

The wide variations in mandibular motion that accompany twin block wear disappeared post-treatment, except for an increase in anteroposterior movement of the mandible.

CONCLUSION

Twin block therapy appears to affect mandibular motion temporarily.

Control of Culicoides sonorensis (Diptera: Ceratopogonidae) blood feeding on sheep with long-lasting repellent pesticides

Culicoides sonorensis is the primary vector of bluetongue and epizootic hemorrhagic disease viruses in North America. Bluetongue disease is one of the most economically important arthropod-borne diseases of sheep in North America, because it causes significant morbidity and mortality and can lead to local quarantines and international trade restrictions. Long-lasting repellent pesticides could be applied to sheep as they are moved down from mountain pastures to protect them from biting midges until the 1st frost. We tested long-lasting pesticides on sheep as repellents against C. sonorensis. Both Python ear tags with 10% zeta-cypermethrin (9.8 g/tag) synergized with 20% piperonyl butoxide (PBO) and a 12-ml low-volume spray application of ready-to-use sheep insecticide (Y-TEX) with 2.5% permethrin and 2.5% PBO in an oil-based formulation were repellent to C. sonorensis for at least 3-5 wk after a single application.

Post-Translational Modification as a Potential Explanation of High Levels of Enzyme Polymorphism: Xanthine Dehydrogenase and Aldehyde Oxidase in DROSOPHILA MELANOGASTER

Xanthine dehydrogenase (XDH) and aldehyde oxidase (AO) in Drosophila melanogaster require for their activity the action of another unlinked locus, maroon-like (mal). While the XDH and AO loci are on chromosome 3, mal maps to the X chromosome. Although functional mal gene product is required for XDH and AO activity, it is possible to examine the effects of mutant mal alleles in those cases when pairs of mutants complement to produce a partial restoration of activity. To test whether mal mediates a post-translational modification of the XDH and AO proteins, we constructed several mal heteroallelic complementing stocks of Drosophila in which the third chromosomes were co-isogenic. Since all lines were co-isogenic for the XDH and AO structural genes, any variation in these enzymes seen when comparing these stocks must have been produced by post-translational modification by mal. We examined the XDH and AO proteins in these stocks by gel-sieving electrophoresis, a procedure that permits independent characterization of a protein's charge and shape, and is capable of discriminating many variants not detected in routine electrophoresis. In every mal heteroallelic combination, there is a significant alteration in protein shape, when compared to wild type. The magnitude of differences in shape of XDH and AO is correlated both with differences in their enzyme activities and with differences in their thermal stabilities. As the body of this variation appears heritable, any functional differences resulting from these variants are of real genetic and evolutionary interest. A similar post-translational modification of XDH and AO by yet another locus, lxd, was subsequently documented in an analogous manner. The pattern of electrophoretic differences produced by mal and lxd modification is similar to that reported for electrophoretic "alleles" of XDH in natural populations. The implication is that heritable variation in electrophoretic mobility at these two enzyme loci, and potentially at other loci, is not necessarily allelic to the structural gene loci.

Brain tissue sodium concentration in multiple sclerosis: a sodium imaging study at 3 tesla

Neuro-axonal degeneration occurs progressively from the onset of multiple sclerosis and is thought to be a significant cause of increasing clinical disability. Several histopathological studies of multiple sclerosis and experimental autoimmune encephalomyelitis have shown that the accumulation of sodium in axons can promote reverse action of the sodium/calcium exchanger that, in turn, leads to a lethal overload in intra-axonal calcium. We hypothesized that sodium magnetic resonance imaging would provide an indicator of cellular and metabolic integrity and ion homeostasis in patients with multiple sclerosis. Using a three-dimensional radial gradient-echo sequence with short echo time, we performed sodium magnetic resonance imaging at 3 T in 17 patients with relapsing-remitting multiple sclerosis and in 13 normal subjects. The absolute total tissue sodium concentration was measured in lesions and in several areas of normal-appearing white and grey matter in patients, and corresponding areas of white and grey matter in controls. A mixed model analysis of covariance was performed to compare regional tissue sodium concentration levels in patients and controls. Spearman correlations were used to determine the association of regional tissue sodium concentration levels in T(2)- and T(1)-weighted lesions with measures of normalized whole brain and grey and white matter volumes, and with expanded disability status scale scores. In patients, tissue sodium concentration levels were found to be elevated in acute and chronic lesions compared to areas of normal-appearing white matter (P < 0.0001). The tissue sodium concentration levels in areas of normal-appearing white matter were significantly higher than those in corresponding white matter regions in healthy controls (P < 0.0001). The tissue sodium concentration value averaged over lesions and over regions of normal-appearing white and grey matter was positively associated with T(2)-weighted (P < or = 0.001 for all) and T(1)-weighted (P < or = 0.006 for all) lesion volumes. In patients, only the tissue sodium concentration value averaged over regions of normal-appearing grey matter was negatively associated with the normalized grey matter volume (P = 0.0009). Finally, the expanded disability status scale score showed a mild, positive association with the mean tissue sodium concentration value in chronic lesions (P = 0.002), in regions of normal-appearing white matter (P = 0.004) and normal-appearing grey matter (P = 0.002). This study shows the feasibility of using in vivo sodium magnetic resonance imaging at 3 T in patients with multiple sclerosis. Our findings suggest that the abnormal values of the tissue sodium concentration in patients with relapsing-remitting multiple sclerosis might reflect changes in cellular composition of the lesions and/or changes in cellular and metabolic integrity. Sodium magnetic resonance imaging has the potential to provide insight into the pathophysiological mechanisms of tissue injury when correlation with histopathology becomes available.

Measurement Scales Used in Elderly Care Abhaya Gupta Radcliffe Measurement Scales Used in Elderly Care £24.95 168pp 9781846192661 1846192668 [Formula: see text]

Although the information in this book is available from other sources. It aims to be a compendium of quantitative scales for use in care. the language is medical, for example, diagnosis and prognosis. however, the content is relevant to nursing. It provides a comprehensive coverage of scales which are or could be used in the assessment of people with potential or actual diagnosis-specific, mental, physical, social and functional issues.

The carer's cosmetic handbook The carer's cosmetic handbook Sharon Tay Jessica Kingsley £16.99 160p 9781843109730 1843109735 [Formula: see text]

USERS OF this book would be either carers or therapists working with people in their own homes or residential or nursing homes. Its use in hospital settings would be limited. Older people may also find it useful.

Population differences of aspartate aminotransferase and peptidase in the bay mussel Mytilus edulis

This investigation has demonstrated considerable heterogeneity among populations and some heterogeneity within populations in the distribution of alleles at two variant loci of Mytilus edulis. Although the causes of this variation remain obscure, some speculations have been made on the basis of available data. A cline for aspartate aminotransferase (AAT) alleles has been observed on the Pacific Coast. An immigration model has been proposed to explain the atypical ecological and genetic characteristics of large mussels found on Amchitka Island, Alaska. Marked differences were found in the distribution of peptidase alleles among collections from Southern California, the North Pacific Ocean, and New Jersey. Deviations from random distribution of phenotypes observed in comparisons made between large and small mussels from the New Jersey collection may reflect selection operating on these loci in this population.

Three-dimensional grain mapping by x-ray diffraction contrast tomography and the use of Friedel pairs in diffraction data analysis

X-ray diffraction contrast tomography (DCT) is a technique for mapping grain shape and orientation in plastically undeformed polycrystals. In this paper, we describe a modified DCT data acquisition strategy which permits the incorporation of an innovative Friedel pair method for analyzing diffraction data. Diffraction spots are acquired during a 360 degrees rotation of the sample and are analyzed in terms of the Friedel pairs ((hkl) and (hkl) reflections, observed 180 degrees apart in rotation). The resulting increase in the accuracy with which the diffraction vectors are determined allows the use of improved algorithms for grain indexing (assigning diffraction spots to the grains from which they arise) and reconstruction. The accuracy of the resulting grain maps is quantified with reference to synchrotron microtomography data for a specimen made from a beta titanium system in which a second phase can be precipitated at grain boundaries, thereby revealing the grain shapes. The simple changes introduced to the DCT methodology are equally applicable to other variants of grain mapping.

Web-based virtual patients in dentistry: factors influencing the use of cases in the Web-SP system

We studied the students' acceptance and utilization of virtual patients (VPs) authored by faculty using the Web-SP system over two consecutive years. We also studied factors of importance for the utilization of VPs for self-assessment. Both year-groups studied found the Web-SP system easy to use and their overall opinion of Web-SP was positive (Median: 5, p25-p75: 4-5). They found the VPs engaging, realistic, fun to use, instructive and relevant to their course. Students used, on average, 9.68 VPs per course, which constitutes 43 percent of the available VPs. The number of VPs available seemed to be sufficient for the target course, even if some of the students preferred a higher number of VPs. Of the VPs encountered, 71% (CI: 68-75%) were VPs with feedback, and correspondingly 29% of the VPs chosen were without feedback. The difference in utilization between both types of VPs was significant, at p < 0.001. Thus, the students clearly favoured VPs with feedback compared to VPs without feedback. There were three modes of engagement in which the VP was utilized. Mode 1 was the preferred mode for VPs without feedback, while mode 3 was dominant for VPs with feedback.. Whether or not a VP was selected for review during a teacher led seminar or not, did not affect student behaviour, at least on the surface. Teacher led seminars may still be of importance to provide credibility to the VPs by integrating them into the curriculum.

Characterization of sirolimus metabolites in pediatric solid organ transplant recipients

Potential age-dependent changes of sirolimus metabolite patterns in pediatric renal transplant recipients remain elusive. Thirteen pediatric solid organ transplant recipients (10 kidney, one combined liver-kidney, two liver, mean age 8.0 +/- 5.0 yr) underwent a sirolimus pharmacokinetic profile in steady-state with 10 samples drawn over 12 h post-intake to calculate the AUC(0-12 h). Concentrations of sirolimus and metabolite were quantified using a validated LC-MS/MS assay and metabolite structures were identified directly in blood extracts using LC-MS/iontrap. Average sirolimus AUC(0-12 h) was 64.9 +/- 29.7 ng h/mL. Median (range) AUC(0-12 h) for each metabolite (ng h/mL) was: 12-hydroxy-sirolimus 7.6 (0.2-18.8), 46-hydroxy sirolimus 3.1 (0.0-12.4), 24-hydroxy sirolimus 4.3 (0.0-12.6), piperidine-hydroxy sirolimus 3.5 (0.0-8.3), 39-O-desmethyl sirolimus 3.6 (0.0-11.3), 16-O-desmethyl sirolimus 5.0 (0.1-9.9), and di-hydroxy sirolimus 4.3 (0.0-32.5). The metabolites reached a median total AUC(0-12 h) of 60% of that of sirolimus. The range was 2.6-136%, indicating significant variability. In all, 77.5% of the metabolites were hydroxylated, while 39-O-desmethyl sirolimus accounted for only 8.4% of the AUC(0-12 h). This is clinically relevant as 39-O-desmethyl sirolimus shows 86-127% cross-reactivity with the antibody of the widely used Abbott sirolimus immunoassay. The metabolism of sirolimus in the children included in our study differed from that reported in adults, which should be considered when monitoring sirolimus exposure immunologically.

An automated, highly sensitive LC-MS/MS assay for the quantification of the opiate antagonist naltrexone and its major metabolite 6beta-naltrexol in dog and human plasma

To support animal studies and clinical pharmacokinetic trials, we developed and validated an automated, specific and highly sensitive LC-MS/MS method for the quantification of naltrexone and 6beta-naltrexol in the same run. In human plasma, the assay had a lower limit of quantitation of only 5pg/mL. This was of critical importance to follow naltrexone pharmacokinetics during its terminal elimination phase. The assay had the following key performance characteristics for naltrexone in human plasma: range of reliable quantification: 0.005-100ng/mL (r2>0.99), inter-day accuracy (0.03ng/mL): 103.7% and inter-day precision: 10.1%. There were no ion suppression, matrix interferences or carry-over.

Risk-based cost modelling of oral rabies vaccine interventions for raccoon rabies

Distribution of oral rabies vaccine (ORV) is an effective but costly strategy to control raccoon rabies. Because of high costs, ORV for raccoon rabies in the U.S. has been limited primarily to epizootic areas, leaving extensive raccoon rabies regions without any ORV intervention. Several cost scenarios for ORV application in raccoon rabies enzootic and epizootic regions were modelled in New York State to obtain estimated costs of ORV baits per scenario and potential savings compared with a uniform ORV baiting strategy. These cost scenarios modelled at the census tract, level the application of ORV baits at different densities according to levels of risk defined by the observed number of raccoon rabies cases per km2 and the expected number of cases per km2 estimated with a Poisson regression model. Bait purchase costs were lower using the modelled cost scenarios than a uniform baiting strategy, for both the NYS enzootic region and the Long Island epizootic zone. The proportion of savings for the NYS enzootic region was 29.57%, and the proportion of savings for the Long Island epizootic zone was 38.9%. Use of these cost scenarios to determine bait distribution by rabies risk level should be considered to maximize efficacy and reduce costs of ORV interventions.

Formocresol blood levels in children receiving dental treatment under general anesthesia

PURPOSE

The purpose of this study was to determine the presence of formocresol in the plasma of children undergoing oral rehabilitation involving pulp therapy under general anesthesia.

METHODS

Thirty 2- to 6-year-old preschool children were enrolled in the study. Preoperative, intra-operative, and postoperative peripheral venous samples were collected from each child. All samples were analyzed for formaldehyde and cresol levels using gas chromatography with mass spectrometry detection.

RESULTS

Eighty-five pulpotomies were performed ranging from 1 to 5 per child. Three hundred twelve blood samples were collected. Analysis revealed that formaldehyde was undetectable above baseline plasma concentration and cresol was undetectable in all samples. Benzyl alcohol (a byproduct of cresol metabolism) was present in all samples except the baseline preoperative samples. Benzyl alcohol concentrations ranged from 0 to 1 mg/ml.

CONCLUSIONS

Formaldehyde was undetectable above baseline plasma concentration, and cresol was undetectable in subjects receiving pulpotomy treatment under general anesthesia. Benzyl alcohol was detected in the plasma of all subjects receiving pulpotomy treatment. The levels present were far below the Food and Drug Administration's recommended daily allowance. It is unlikely that formocresol, when used in the doses typically employed for a vital pulpotomy procedure, poses any risk to children.

Observations of intergranular stress corrosion cracking in a grain-mapped polycrystal

Nondestructive three-dimensional mapping of grain shape, crystallographic orientation, and grain boundary geometry by diffraction contrast tomography (DCT) provides opportunities for the study of the interaction between intergranular stress corrosion cracking and microstructure. A stress corrosion crack was grown through a volume of sensitized austenitic stainless steel mapped with DCT and observed in situ by synchrotron tomography. Several sensitization-resistant crack-bridging boundaries were identified, and although they have special geometric properties, they are not the twin variant boundaries usually maximized during grain boundary engineering.

Airway epithelial cell senescence in the lung allograft

Chronic lung allograft dysfunction, manifesting as bronchiolitis obliterans syndrome (BOS), is characterized by airway epithelial injury, impaired epithelial regeneration and subsequent airway remodeling. Increased cellular senescence has been reported in renal and liver allografts affected by chronic allograft dysfunction but the significance of cellular senescence in the airway epithelium of the transplanted lung is unknown. Thirty-four lung transplant recipients, 20 with stable graft function and 14 with BOS, underwent transbronchial lung biopsy and histochemical studies for senescence markers in small airways. Compared to nontransplant control lung tissue (n = 9), lung allografts demonstrate significantly increased airway epithelial staining for senescence-associated beta galactosidase (SA beta-gal) (p = 0.0215), p16(ink4a) (p = 0.0002) and p21(waf1/cip) (p = 0.0138) but there was no difference in expression of these markers between stable and BOS affected recipients (p > 0.05). This preliminary cross-sectional study demonstrates that cellular senescence occurs with increased frequency in the airway epithelium of the lung allograft but does not establish any association between airway epithelial senescence and BOS. A prospective longitudinal study is required to better address any potential causal association between airway epithelial senescence in stable allograft recipients and the subsequent development of BOS.

Molecular diagnosis of vascular access device-associated infection in children being treated for cancer or leukaemia

Blood samples were collected for quantitative 16S rDNA analysis from the vascular access device (VAD) of patients presenting with fever at participating centres of the UK Children's Cancer and Leukaemia Group. In total, 260 of 301 episodes of fever were evaluable and were classified as probable, possible, unlikely or unclassifiable VAD-associated infection. The sensitivity of the 16S rDNA assay declined concomitantly with delays from time of presentation to sampling. The sensitivity with >0.125 pg of bacterial DNA/microL of whole blood was 80% for the 20 probable VAD-associated infections diagnosed with samples collected on the day of or day following presentation. The specificity rose with increasing amounts of bacterial DNA, from 93% with >0.125 pg, to 98% with 0.25-0.5 pg, and to 100% with >0.5 pg/microL blood. The positive predictive value (for probable or possible) was 88% (95% CI 70-98%) with 0.25 pg/microL, and 100% (95% CI 83-100%) with >0.5 pg/microL. All 18 (6.8%) episodes with >0.5 pg of bacterial DNA/microL blood were associated with positive blood cultures. Identifications derived from the DNA sequence were consistent with the blood culture identifications for 15 of the 17 episodes with a DNA sequence identification. The VAD was removed because of suspected infection in six (2.8%) of 216 episodes with <0.125 pg of bacterial DNA/microL, in one (5%) of 20 episodes with 0.125-0.25 pg/microL, in one (16.7%) of six episodes with 0.25-0.5 pg/microL, and in nine (50%) of 18 episodes with >0.5 pg/microL. A bacterial DNA concentration of >0.5 pg/microL in blood drawn through a central venous catheter at the time of fever presentation had a high positive predictive value for VAD-associated infection and predicted an increased risk of VAD removal because of suspected infection.

The implementation of European Association of Urology guidelines in the management of acute epididymo-orchitis

INTRODUCTION

Acute epididymo-orchitis is a common and increasing problem. This retrospective study reviewed whether the European Association of Urology guidelines for the management of acute epididymo-orchitis, which form the basis of this Trust's present inter-departmental guidelines, are being effectively implemented.

PATIENTS AND METHODS

Case notes of 53 patients attending the emergency department with acute epididymo-orchitis over a 6-month period were reviewed retrospectively. The hospital results' database was used to confirm the diagnostic tests requested on patients at the time of their initial presentation.

RESULTS

Of the study cohort, 26 patients were aged </= 35 years and 27 patients were aged > 35 years. The results demonstrated that a sexual history was documented in only 43.4% of cases. A mid-stream urine sample was sent for routine culture in 54.7% of cases whilst urine for the Chlamydia polymerase chain reaction (PCR) test was obtained in 17% and a urethral swab performed in 5.6%. Antibiotics were prescribed in 81% of cases. Of these patients, 46.5% received ciprofloxacin alone (mean age, 52 years; range, 18-87 years), 25.5% received doxycycline alone (mean age, 30 years; range, 18-45 years) and 21% received both ciprofloxacin and doxycycline (mean age, 33 years; range 18-49 years). In 26.4% of cases, verbal advice to attend a genito-urinary medicine clinic was given, whilst a formal telephone referral was made in only one case. Formal urological follow-up was arranged for only three out of 11 patients aged > 50 years.

CONCLUSIONS

Although a joint emergency department/urology clinical protocol for the investigation and treatment of acute epididymo-orchitis already exists within the Trust, our current management conforms to this in only a minority of cases. Many different strategies can be employed in the implementation of clinical practice guidelines and all are associated with variable degrees of success. The regular movement of junior staff through each department necessitates that the distribution of management protocols and guidelines occurs at frequent intervals throughout the year and that their implementation is continuously monitored so that, if necessary, further implementation strategies can be employed.

Predicting grade of cerebral glioma using vascular-space occupancy MR imaging

BACKGROUND AND PURPOSE

MR imaging can measure tissue perfusion and the integrity of the blood-brain barrier. We hypothesize that a combined measure of cerebral blood volume and vascular permeability using vascular-space occupancy (VASO) MR imaging, a recently developed imaging technique, is of diagnostic value for predicting tumor grade.

MATERIALS AND METHODS

Thirty-nine patients (9 World Health Organization [WHO] grade II, 20 grade III, and 10 grade IV as determined by histopathologic assessment) were examined using VASO MR imaging, and regions-of-interest analysis was performed in tumoral regions, as well as in regions contralateral to the tumor. A Mann-Whitney test was conducted on the resulting VASO indices for a pairwise comparison across tumor grades. Nominal logistic regression was used to evaluate the use of VASO parameters for predicting group membership (by the percentage of correct classifications).

RESULTS

The ratio between tumor side and contralateral side, VASO(Ratio), showed significant differences in all 3 of the pairwise comparisons (P < .01). VASO values in the tumoral regions, VASO(Tumor), showed significant difference between grade II and III and between II and IV but not between III and IV. Both VASO(Tumor) and VASO(Ratio) were found to be significant predictors of tumor grade, giving diagnostic accuracies of 66.7% and 71.8%, respectively. When testing to discriminate grade II tumors from higher grade tumors, the areas under the receiver operating characteristic curve were found to be 0.974 and 0.985 for VASO(Tumor) and VASO(Ratio), respectively.

CONCLUSION

VASO MR imaging can be used for noninvasive tumor grade prediction based on cerebral blood volume and vascular permeability. VASO is more effective in separating WHO grade II from higher grades than in separating grade III from grade IV.

Kinematic and temporal interactions of the lumbar spine and hip during trunk extension in healthy male subjects

Kinematic properties of trunk extension are considered sensitive differentiators of movement between asymptomatic and low back pain subjects. The aim of this study was to quantify the continuous interaction of the hip and lumbar spine kinematics and temporal characteristics as a function of direction during the task of trunk bending backwards and returning to the upright position in healthy young subjects. The sagittal hip and lumbar spine kinematics during the extension task were examined in 18 healthy male subjects. Five trials of trunk extension were recorded for each subject and paired t-tests were then used to determine significant differences (P < 0.05) between the mean lumbar and the hip time-normalized kinematic and temporal variables. The data from the full cycle of trunk extension was analyzed with respect to movement initiation, time to reach peak velocity and peak angular displacement during the full cycle of trunk extension. Three distinct phases of movements were identified based on the continuous movement trajectories of velocity and angular displacement in the lumbar spine and hip; that of extension, return and, a terminal overcorrection phase. There were significant differences identified in the respective mean peak angular velocities of the lumbar spine (21.7 +/- 8.6, 37.0 +/- 14.7, 8.3 +/- 5.0 deg/s) when compared with those of hip (14.6 +/- 6.1, 21.7 +/- 8.5, 5.4 +/- 3.5 deg/s) in each of these three phases. The lumbar spine initiated the movement of trunk extension when bending backwards and returning to the upright position significantly early than that of the hip. These results highlight that in normal healthy adults there is the tendency for the lumbar spine to dominate over the hip during the task of backward trunk bending in terms of the amount and velocity of movement. At the end of extension the kinematics of the lumbar spine and hip kinematic are characterized by a terminal overcorrection phase marking the completion of the movement.

Comparing cerebral blood volume and vascular permeability measurements with tumor volume measurements following anti-angiogenesis therapy in recurrent gliomas

2030

Background: Dynamic susceptibility contrast-enhanced MRI (DSC MRI) is emerging as an important adjunctive biomarker to assess the effectiveness of anti-angiogenic therapies in the treatment of brain tumors. The purpose of our study is to compare changes in relative cerebral blood volume (rCBV) and in perfusion-permeability index (KTrans) with those of tumor volume measurements (T1c, T2/Flair) in predicting tumor therapeutic response in recurrent high-grade gliomas treated with bevacizumab, an anti-VEGF monoclonal antibody. Methods: 11 patients were treated with one to four cycles of bevacizumab and CPT-11. Their histological diagnoses were: glioblastoma multiforme (n=7), anaplastic astrocytoma (n=2), anaplastic oligodendroglioma (n=1), and diffuse pontine glioma (n=1). All patients had baseline DSC MRI scans prior to the administration of bevacizumab and were followed clinically and radiographically with both conventional and DSC MRI. Mixed model regression was used to compare the pre-treatment and post-treatment levels of each response measure. Results: There were statistically significant reductions in both actual rCBV measurements and T1c enhancement following treatment with bevacizumab and CPT-11. The pretreatment rCBV and T1c rates of change (as determined per 100 days) correlated significantly with time (p values are 0.0229 and 0.0014, respectively), while only the post treatment rCBV demonstrated significant rate of change (p value = 0.0001), suggesting that rCBV may reflect the effects of bevacizumab better than tumor volume. However, when the changes in rate from pre- to post-treatment status were considered, both rCBV and T1c demonstrated significance (p= 0.0001, 0.0157, respectively). There was a trend towards females having higher mean levels of KTrans than males at the same time point relative to treatment onset, but the result was not statistically significant (p=0.072). Conclusions: rCBV as measured from DSC MRI can be used as a surrogate biomarker to determine therapeutic response to bevacizumab. This may influence the neurosurgical risk/benefit equation as well as alter the aggressiveness of the post-operative adjuvant therapy in patients with recurrent gliomas.

No significant financial relationships to disclose.

Hip and lumbar continuous motion characteristics during flexion and return in young healthy males

Studies describing the movement patterns, relative contributions and kinematic characteristics of the lumbar spine and hip present conflicting results. Differences could be due to sample characteristics, methodological issues and descriptive methods. The purpose of this study was to describe the amount and pattern of lumbar spine and hip movement during flexion and return using a range of kinematic and temporal variables. Our aim is to gain a more complete picture of movement patterns taking place at the hip and lumbar spine in asymptomatic individuals. Ultimately the development of a normative database of movement patterns will help to clarify comparative movement interpretation in patients with lumbar back pain. This study analysed lumbar spine and hip motion in group of young healthy males (n = 20) during the flexion and return movement. A motion analysis system captured continuous movement profiles in the sagittal plane. Each participant performed five trials of flexion and return. The angular and velocity data were averaged and used for statistical and descriptive analysis. The kinematic and temporal variables distinguishing statistically significant differences in the lumbar spine and hip movement patterns are not the same for the flexion and return movement. However, within this group four (20%) demonstrated a pattern angular change between the lumbar spine and hip which was different from the other participants. Even within a healthy group of participants individual differences exist in the lumbar spine and hip movement patterns during flexion and return.

Histogram analysis versus region of interest analysis of dynamic susceptibility contrast perfusion MR imaging data in the grading of cerebral gliomas

BACKGROUND AND PURPOSE

Histogram analysis can be applied to dynamic susceptibility contrast (DSC) perfusion MR imaging datasets and can be as effective as traditional region-of-interest (ROI) measurements of relative cerebral blood volume (rCBV), an operator-dependent method. We compare the routine ROI method with histogram analysis in the grading of glial neoplasms.

MATERIALS AND METHODS

Ninety-two patients underwent conventional and DSC MR imaging. Routine rCBV (rCBVmax) measurements were obtained from ROIs of the maximal abnormality within the glioma. Histogram analysis rCBVT was performed with an ROI drawn around the maximal tumor diameter. Spearman rank correlations measured associations among glioma grade, rCBVmax, and histogram measures. Mann-Whitney tests compared grade with respect to rCBV and histogram measures. Logistic regression and McNemar test compared the utility of rCBVmax and histogram measures for detecting high grade gliomas.

RESULTS

Routine rCBVmax analysis showed significant correlation with grade (r = 0.734, P < .001). Histogram rCBVT metrics showed significant correlation with grade (P < .008); the 3 highest were rCBVT SD, SD50, and mean25 (r = 0.718, 0.684, and 0.683, respectively). Grade could be predicted by rCBVmax (P < .001) as well as rCBV(T) (P < .008). Three rCBVT histogram measures (SD, SD25, and SD50) detected high-grade glioma with significantly higher specificity than rCBVmax when the diagnostic tests were constrained to have at least 95% sensitivity.

CONCLUSION

rCBVT histogram analysis is as effective as rCBVmax analysis in the correlation with glioma grade. Inexperienced operators may obtain perfusion metrics using histogram analyses that are comparable with those obtained by experienced operators using ROI analysis.

Correlation of diffusion tensor and dynamic perfusion MR imaging metrics in normal-appearing corpus callosum: support for primary hypoperfusion in multiple sclerosis

BACKGROUND AND PURPOSE

Hypoperfusion of the normal-appearing white matter in multiple sclerosis (MS) may be related to ischemia or secondary to hypometabolism from wallerian degeneration (WD). This study evaluated whether correlating perfusion and diffusion tensor imaging (DTI) metrics in normal-appearing corpus callosum could provide support for an ischemic mechanism for hypoperfusion.

MATERIALS AND METHODS

Fourteen patients with relapsing-remitting MS (RRMS) and 17 control subjects underwent perfusion MR imaging and DTI. Absolute measures of cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) were calculated. Mean diffusivity (MD) and fractional anisotropy (FA) maps were computed from DTI data. After visual coregistration of perfusion and DTI images, regions of interest were placed in the genu, central body, and splenium of normal-appearing corpus callosum. Pearson product-moment correlation coefficients were calculated using mean DTI and perfusion measures in each region.

RESULTS

In the RRMS group, CBF and CBV were significantly correlated with MD in the splenium (r = 0.83 and r = 0.63, respectively; both P < .001) and in the central body (r = 0.86 and r = 0.65, respectively; both P < .001), but not in the genu (r = 0.23 and 0.25, respectively; both P is nonsignificant). No significant correlations were found between MTT and DTI measures or between FA and any perfusion measure in the RRMS group. No significant correlations between diffusion and perfusion metrics were found in control subjects.

CONCLUSION

In the normal-appearing corpus callosum of patients with RRMS, decreasing perfusion is correlated with decreasing MD. These findings are more consistent with what would be expected in primary ischemia than in secondary hypoperfusion from WD.

Design of a single tube RT-PCR assay for the diagnosis of human infection with highly pathogenic influenza A(H5) viruses

Concerns about emergence of a pandemic strain of influenza have been increasing. The strains of highly pathogenic influenza A(H5N1) currently circulating are considered among the most plausible candidates for giving rise to a pandemic strain. In this study the design and development of a RT-PCR assay specific for these highly pathogenic influenza A(H5) strains is presented. This is achieved in part by the design of a primer targeting the coding region for the protease cleavage site of the hemagglutinin, and another primer derived from a pan-hemagglutinin RT-PCR assay also presented in this study. It is shown that the HPAI A(H5) specific assay amplifies only the nucleic acids of highly pathogenic A(H5), with a high sensitivity.

Multicenter comparison of nucleic acid extraction methods for detection of severe acute respiratory syndrome coronavirus RNA in stool specimens

The emergence of a novel coronavirus (CoV) as the cause of severe acute respiratory syndrome (SARS) catalyzed the development of rapid diagnostic tests. Stool samples have been shown to be appropriate for diagnostic testing for SARS CoV, although it has been recognized to be a heterogeneous and difficult sample that contains amplification inhibitors. Limited information on the efficiency of extraction methods for the purification and concentration of SARS CoV RNA from stool samples is available. Our study objectives were to determine the optimal extraction method for SARS CoV RNA detection and to examine the effect of increased specimen volume for the detection of SARS CoV RNA in stool specimens. We conducted a multicenter evaluation of four automated and four manual extraction methods using dilutions of viral lysate in replicate mock stool samples, followed by quantitation of SARS CoV RNA using real-time reverse transcriptase PCR. The sensitivities of the manual methods ranged from 50% to 100%, with the Cortex Biochem Magazorb method, a magnetic bead isolation method, allowing detection of all 12 positive samples. The sensitivities of the automated methods ranged from 75% to 100%. The bioMérieux NucliSens automated extractor and miniMag extraction methods each had a sensitivity of 100%. Examination of the copy numbers detected and the generation of 10-fold dilutions of the extracted material indicated that a number of extraction methods retained inhibitory substances that prevented optimal amplification. Increasing the volume of sample input did improve detection. This information could be useful for the extraction of other RNA viruses from stool samples and demonstrates the need to evaluate extraction methods for different specimen types.

Whole-brain N-acetylaspartate spectroscopy and diffusion tensor imaging in patients with newly diagnosed gliomas: a preliminary study

BACKGROUND AND PURPOSE

Glial cancer cells can be found well beyond the MR imaging T2 signal-intensity hyperintensity. To quantify the extent of the diffuse microstructural tissue damage possibly due to the presence of these satellite tumor cells, we investigated the relationships between global metabolic and microstructural abnormalities in the normal-appearing brain regions of patients with newly diagnosed glioma.

MATERIAL AND METHODS

Ten patients (6 men, 4 women) with radiologically suspected untreated supratentorial glial tumors and 9 healthy controls (5 men, 4 women) were studied with T1- and T2-weighted MR imaging, diffusion-weighted echo-planar MR imaging, and whole-brain N-acetylaspartate (WBNAA) proton MR spectroscopy. The relationship between the WBNAA concentration, the mean diffusivity (MD), and fractional anisotropy (FA) values in a large contralateral normal-appearing white matter (NAWM) brain region was investigated with the Spearman rank correlation test.

RESULTS

WBNAA values were significantly lower (P < .001) in patients (9.7 +/- 1.7 mmol/L) than controls (13.1 +/- 1.1 mmol/L). MD values were higher (P = .0001) in patients (0.95 +/- 0.07 mm(2)s(-1)) than in controls (0.61 +/- 0.04 mm(2)s(-1)). FA values did not differ between patients (0.42 +/- 0.08) and controls (0.43 +/- 0.041). A strong inverse correlation between WBNAA and MD (r = -0.88, P = .0008) was found in the patients but not in controls (r = 0.012, P = .975).

CONCLUSION

The correlation between the WBNAA and MD in the contralateral NAWM suggests that the microstructural damage possibly related to the presence of infiltrative tumor cells contributes to WBNAA decline in these patients.

Pharmacokinetics of pyridostigmine in a child with postural tachycardia syndrome

Pyridostigmine has been proposed for the treatment of postural orthostatic tachycardia syndrome in adults at a dose of 60 mg twice daily, but no dosing recommendation exists for children. With the approval of our local ethics board, we tested the pharmacokinetics of pyridostigmine in 6 children with myasthenia and a pediatric index patient with severe postural orthostatic tachycardia syndrome whose condition failed all conventional therapy and who had developed significant postural hypertension. Pyridostigmine was quantified by using a validated, semiautomated, and specific high-performance liquid chromatography/tandem mass spectrometry assay in combination with online column-switching extraction and turbo electrospray ionization. The patient with postural orthostatic tachycardia syndrome showed a dose-dependent favorable response to oral pyridostigmine. Pharmacokinetic evaluation revealed a short half-life of 2.29 hours, similar to the 2.0 +/- 0.63 hours in the patients with myasthenia. The patient with postural orthostatic tachycardia syndrome has subsequently been treated at a dose of 45 mg in the morning, 30 mg at lunchtime, and 15 mg at bedtime; after 9 months, there has been persistent positive effect and without additional blood pressure medication. No major adverse effects occurred. Pyridostigmine has been a safe and effective treatment modality for this child with postural orthostatic tachycardia syndrome. The short half-life suggests that dosing 3 times per day is preferable.