Evolution of a Meningothelial Meningioma: From WHO Grade 1 to Anaplastic Grade 3 with Extracranial Metastasis Including Extensive Liver Metastasis

A 61-year-old patient was diagnosed with a left-sided falx meningioma. Histopathological analysis following extirpation showed a meningothelial meningioma ZNS WHO grade 1 with sparse mitoses. Over the course of 12 years, the patient received irradiation (54.0 Gy), peptide radio-receptor therapy (177Lu-DOMITATE) and targeted therapy (mTOR inhibitor). Follow-up imaging revealed an increased size of the residual tumor. Due to increased liver function parameters, imaging of the liver was performed, showing widespread space-occupying lesions with atypical appearance. Biopsy revealed metastasis of the meningioma, now with 2.7 mitoses/mm2, necrosis and homozygous CDKN2A/B deletion, corresponding to an anaplastic CNS meningioma WHO grade 3. A second small meningioma on the left petroclival side has been consistent in size over 12 years. Metastatic meningiomas pose a pertinent clinical challenge due to poor prognosis. The lung, bone, liver and cervical lymph nodes are the most common sites of extracranial metastasis. According to the World Health Organization criteria, the most important predictive factor for recurrence and metastasis is the tumor grade.

[Choosing the right imaging for the diagnostics and assessment of the course of peripheral nerve injuries]

BACKGROUND

Nerve injuries are a frequent problem in routine clinical practice and require intensive interdisciplinary care.

OBJECTIVE

The current status of imaging to confirm the diagnosis of nerve injuries is described. The role of high-resolution ultrasound and magnetic resonance imaging (MRI) in the diagnostics and follow-up of peripheral nerve injuries is elaborated.

MATERIAL AND METHODS

Review of the current state of imaging to confirm the diagnosis of nerve injuries.

RESULTS

Depending on the suspected site of damage, the primary domain of magnetic resonance (MR) imaging (MR neurography) is injuries in the region of the spine, nerve roots, brachial plexus and lumbar plexus, pelvis and proximal thigh. In contrast, in other peripheral nerve lesions of the extremities the advantages of high-resolution nerve ultrasound in a dynamic setting predominate. The MR neurography is indicated here, especially in the frequent bottleneck syndromes and only in very isolated and selected cases.

CONCLUSION

In addition to a correct anatomical assignment, the timely decision for a possible intervention and the appropriate concomitant treatment are an important basis for a favorable prognosis of nerve injuries. Imaging techniques should therefore be used early in the diagnostics and follow-up controls of peripheral nerve injuries.

Retrospective longitudinal assessment of optic nerve sheath diameter in patients with malignant glioma

INTRODUCTION

Glioblastoma (GBM) is a tumor with rapid growth and a possible relationship to elevated intracranial pressure (ICP). High ICP may not always be associated with clinical signs. A non-invasive technique for assessment of ICP is measuring the optic nerve sheath diameter (ONSD). Identifying patients who need immediate intervention is of importance in neuro-oncological care. The goal of this study is to assess the available magnetic resonance imaging (MRI) of patients with GBM with respect to pre- and postoperative ONSD.

METHODS AND MATERIALS

Retrospective data analysis was performed on all patients operated for GBM at a tertiary care center between 2010 and 2020. Two pre and one postoperative MRI had to be available. Clinical data and ONSD at multiple time points were analyzed and correlated, as well as preoperative volumetrics.

RESULTS

Sixty-seven patients met the inclusion criteria. Clinical signs of elevated ICP were seen in 25.4% (n = 17), while significant perifocal edema was present in 67.2% (n = 45) of patients. Clinical signs of preoperatively elevated ICP were associated with significantly elevated ONSD at diagnosis (p < 0.001) as well as preoperative tumor volume (p < 0.001). Significant perifocal edema at the time of diagnosis was associated with elevated ONSD (p = 0.029) and higher tumor volume (p = 0.003). In patients with significant edema, ONSD increased significantly between preoperative MRIs (p = 0.003/005). In patients with clinical signs of raised ICP, ONSD also increased, whereas it was stable in asymptomatic patients (yes: 5.01+/-4.17 to 5.83+/-0.55 mm, p = 0.010, no: 5.17+/-0.46 mm to 5.38+/-0.41 mm, p = 0.81). A significant increase of ONSD from diagnosis to preoperative MRI and a significant decrease until 3 months postoperatively were observed (p < 0.001).

CONCLUSIONS

ONSD might help identify high ICP in patients with GBM. In this first-of-its kind study, we observed a significant increase of ONSD preoperatively, likely associated with edema. Postoperatively, ONSD decreased significantly until 3 months after surgery and increased again at 12 months. Further prospective data collection is warranted.

Noninvasive and invasive imaging of lower-extremity acute and chronic venous thrombotic disease

The spectrum of venous thromboembolic (VTE) disease encompasses both acute deep venous thrombosis (DVT) and chronic postthrombotic changes (CPC). A large percentage of acute DVT patients experience recurrent VTE despite adequate anticoagulation, and may progress to CPC. Further, the role of iliocaval venous obstruction (ICVO) in lower-extremity VTE has been increasingly recognized in recent years. Imaging continues to play an important role in both acute and chronic venous disease. Venous duplex ultrasound remains the gold standard for diagnosing acute VTE. However, imaging of CPC is more complex and may involve computed tomography, magnetic resonance, contrast-enhanced ultrasound, or intravascular ultrasound. In this narrative review, we aim to discuss the full spectrum of venous disease imaging for both acute and chronic venous thrombotic disease.

Atherosclerotic plaque composition and specific endovascular considerations in the end stage renal disease patients: a narrative review

Background and Objective

Vascular calcification (VC) and resulting vascular disease is one of the major causes of cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD). CKD itself is increasingly recognized as a risk factor for cardiac and peripheral arterial disease (PAD). This paper examines the atherosclerotic plaque composition and specific endovascular considerations in the end stage renal disease (ESRD) patients. The literature was reviewed regarding the current status of medical and interventional management arteriosclerotic disease in patients with CKD. Lastly, three representative cases displaying typical endovascular treatment options are provided.

Methods

A literature search was performed in PubMed covering publications up to September 2021 as well as discussion with experts in the field.

Key Content and Findings

The high prevalence of atherosclerotic lesions in patients with chronic renal failure and high (re-)stenosis cause problems in the medium and long term as vascular calcium load represents one of the most widely encountered predictors of failure of endovascular treatment of PAD and future cardiovascular events (e.g., coronary calcium score). Patients with CKD also suffer from a greater risk for major vascular adverse events in general and worse revascularization outcomes following peripheral vascular intervention. A correlation between calcium burden and drug-coated balloon (DCB) performance has been established for PAD necessitating the need for different tools to cope with vascular calcium such as endoprosthesis or braided stents. Patients with CKD are at a higher risk of developing contrast-induced nephropathy (CIN). In addition to recommendations such as the administration of intravenous fluids, carbon dioxide (CO₂) angiography is one option to potentially provide an effective and safe alternative both to iodine-based contrast media allergy and to the use of iodine-based contrast media in patients with CKD.

Conclusions

Management and endovascular procedures of patients with ESRD are complex. In the course of time, new endovascular therapy methods have been developed such as directional atherectomy (DA) and the so-called "pave-and-crack" technique to deal with high vascular calcium burden. Besides interventional therapy, vascular patients with CKD benefit from aggressive medical management.

Man-machine interaction-based phenotyping identifies pathophysiologically and prognostically informative clusters among patients with mitral regurgitation undergoing transcatheter edge-to-edge repair

Background

Depending on etiology, extent of disease progression, and comorbidities, patients with severe mitral regurgitation (MR) typically present with considerable heterogeneity.

Purpose

This study therefore sought to improve diagnostic and prognostic resolution in patients undergoing mitral valve transcatheter edge-to-edge repair (MV TEER) for severe MR by developing a man-machine interaction-based phenotyping approach.

Methods

All 609 patients from this single-center registry underwent MV TEER for severe MR between 2009 and 2020. Unsupervised agglomerative clustering was applied to preprocedural echocardiography data, and an artificial neural network (ANN) was subsequently trained for future patient-to-cluster assignment. Primary outcome measure was postprocedural 5-year survival

Results

Cluster analysis revealed four pathophysiologically and prognostically informative phenotypes:

Cluster 1 was constituted by patients (n=188) presenting with preserved left ventricular ejection fraction (LVEF; 56.5±7.79%) and regular left ventricular end-systolic diameter (LVESD; 35.2±7.52 mm). 5-year survival in patients from cluster 1, hereinafter serving as a reference, was 60.9% (95% CI: 53.3–69.7%).

Patients from cluster 2 (n=102) also presented with preserved LVEF (55.7±7.82%) and regular LVESD (34.9±7.68 mm), but showed the largest mitral valve effective regurgitant orifice area (0.623±0.360 cm2) and highest systolic pulmonary artery pressures (68.4±16.2 mmHg). Consequently, their 5-year survival ranged at 43.7% (95% CI: 33.2–57.6%; p-value: 0.032).

Patients from cluster 3 (n=270) were predominantly characterized by impaired left ventricular systolic function (LVEF: 31.0±10.4%) and dilated left ventricular diameters (LVESD: 53.2±10.9 mm), and their 5-year survival was reduced to 38.3% (95% CI: 31.9–46.1%; p-value: &lt;0.001).

Poorest 5-year survival (23.8% [95% CI: 12.8–44.3%]; p-value: &lt;0.001) was observed in patients from cluster 4 (n=49) with biatrial dilatation (left atrial volume: 312±113 mL; right atrial area: 46.0±8.83 cm2) although LVEF was only slightly reduced (51.5±11.0%). All patients from cluster 4 were diagnosed with atrial fibrillation.

An ANN could precisely predict cluster assignment (accuracy: 85.2%), detecting patients from high-risk clusters 3 and 4 with excellent specificity (95.0% and 99.4%, respectively).

Conclusion

Assigning patients to clusters using a multiparametric phenotypic approach can facilitate risk stratification in future clinical practice. Our unsupervised machine learning-based classification system differs from previous approaches for risk stratification, because we do neither hypothesize a linear sequence of accumulated pathologies caused by severe MR (potentially ignoring the aggravating impact of comorbidities), nor do we stratify patients into low- and high-risk cohorts in accordance with a single variable's dichotomy (prone to oversimplification).

Funding Acknowledgement

Type of funding sources: None.

Detection of spinal long fiber tract degeneration in HSP: Improved diffusion tensor imaging

Spinal diffusion tensor imaging (sDTI) is still a challenging technique for selectively evaluating anatomical areas like the pyramidal tracts (PT), dorsal columns (DC), and anterior horns (AH) in clinical routine and for reliably quantifying white matter anisotropy and diffusivity. In neurodegenerative diseases, the value of sDTI is promising but not yet well understood. The objective of this prospective, single-center study was to evaluate the long fiber tract degeneration within the spinal cord in normal aging (n = 125) and to prove its applicability in pathologic conditions as in patients with molecular genetically confirmed hereditary spastic paraplegias (HSP; n = 40), a prototypical disease of the first motor neuron and in some genetic variants with affection of the dorsal columns. An optimized monopolar Stejskal-Tanner sequence for high-resolution, axial sDTI of the cervical spinal cord at 3.0 T with advanced standardized evaluation methods was developed for a robust DTI value estimation of PT, DC, and AH in both groups. After sDTI measurement at C2, an automatic motion correction and an advanced semi-automatic ROI-based, standardized evaluation of white matter anisotropy and diffusivity was performed to obtain regional diffusivity measures for PT, DC, and AH. Reliable and stable sDTI values were acquired in a healthy population without significant decline between age 20 and 65. Reference values for PT, DC, and AH for fractional anisotropy (FA), mean diffusivity (MD), and radial diffusivity (RD) were established. In HSP patients, the decline of the long spinal fiber tracts could be demonstrated by diffusivity abnormalities in the pyramidal tracts with significantly reduced PT_FA (p < 0.001), elevated PT_RD (p = 0.002) and reduced PT_MD (p = 0.003) compared to healthy controls. Furthermore, FA was significantly reduced in DC_FA (p < 0.001) with no differences in AH. In a genetically homogeneous subgroup of SPG4 patients (n = 12) with affection of the dorsal columns, DC_RD significantly correlated with the overall disease severity as measured by the Spastic Paraplegia Rating Scale (SPRS) (r = - 0.713, p = 0.009). With the most extensive sDTI study in vivo to date, we showed that axial sDTI combined with motion correction and advanced data post-processing strategies enables robust measurements and is ready to use, allowing recognition and quantification of disease- and age-related changes of the PT, DC, and AH. These results may also encourage the usage of sDTI in other neurodegenerative diseases with spinal cord involvement to explore its capability as selective biomarkers.

Advanced portal venous access techniques for transjugular intrahepatic portosystemic shunt placement

Introduction

Transjugular intrahepatic portosystemic shunt (TIPS) placement is a well-established but technically challenging procedure for the management of sequelae of end-stage liver disease. Performed essentially blindly, traditional fluoroscopically guided TIPS placement requires multiple needle passes and prolonged radiation exposure to achieve successful portal venous access, thus increasing procedure time and the risk of periprocedural complications. Several advanced image-guided portal access techniques, including intracardiac echocardiography (ICE)-guided access, cone-beam CT (CBCT)-guided access and wire-targeting access techniques, can serve as alternatives to traditional CO₂ portography-based TIPS creation.

Methods

A literature search was performed on the electronic databases including MEDLINE and Embase, from 2000 to the present to identify all relevant studies. The reference list also included studies identified manually, and studies referenced for other purposes.

Findings

The main benefit of these advanced access techniques is that they allow the operator to avoid essentially blind portal punctures, and the ability to visualise the target, thus reducing the number of required needle passes. Research has shown that ICE-guided access can decrease the radiation exposure, procedure time and complication rate in patients undergoing TIPS placement. This technique is particularly useful in patients with challenging portal venous anatomy. However, ICE-guided access requires additional equipment and possibly a second operator. Other studies have shown that CBCT-guided access, when compared with traditional fluoroscopy-guided access, provides superior visualisation of the anatomy with similar amount of radiation exposure and procedure time. The wire-targeting technique, on the other hand, appears to offer reductions in procedure time and radiation exposure by enabling real-time guidance. However, this technique necessitates percutaneous injury to the liver parenchyma in order to place the target wire.

Conclusion

Advanced portal access techniques have certain advantages over the traditional fluoroscopically guided TIPS access. To date, few studies have compared these advanced guided access options, and further research is required.

Serial measurement of biomarkers and the risk of stroke or systemic embolism and bleeding in patients with atrial fibrillation in ENGAGE AF-TIMI 48

Background

Patients with atrial fibrillation (AF) have progressive cardiac structural changes that may be manifest by biomarkers of myocardial injury and hemodynamic stress. Baseline values of hsTnT (high-sensitivity troponin T), and NT-proBNP (N-terminal pro-brain natriuretic peptide) are associated with stroke risk and GDF-15 (growth differentiation factor-15) is associated with bleeding risk in patients with AF. However, the variability of these biomarkers over time and their associations with stroke or systemic embolism events (S/SEE) and bleeding in patients with AF remain unclear.

Purpose

We examined whether patients with AF demonstrate detectable changes in these biomarkers over 12 months and whether such changes from baseline to 12 months are associated with the subsequent risk of S/SEE (hsTnT, NT-proBNP) and bleeding (GDF-15).

Methods

ENGAGE AF-TIMI 48 was a multinational randomized trial of the oral factor Xa inhibitor edoxaban in patients with atrial fibrillation and a CHADS2 score ≥2. We performed a nested prospective biomarker study in 6062 patients, analyzing hsTnT, NT-proBNP, and GDF-15 at baseline and 12 months. Event rates were estimated and displayed with annualized event rates after 12 months.

Results

Of 6062 patients, hsTnT was dynamic in 46.9% (≥2 ng/L change), NT-proBNP in 51.9% (≥200 pg/L change), GDF-15 in 45.6% (≥300 pg/L change) between baseline and 12 months. In addition, 7.7% in hsTnT shifted from low-&gt;high categories, 9.4% in NT-proBNP from low-&gt;high, 10.6% in GDF-15 from low-&gt;high over 12 months (Figure). Elevated hsTnT (≥14 ng/L) and NT-proBNP (≥900 pg/L) either at baseline or at 12 months were independently associated with higher rates of subsequent S/SEE, and elevated GDF-15 (≥1800 pg/L) either at baseline or at 12 months were independently associated with higher rates of subsequent bleeding (P&lt;0.001 for each). In a Cox regression model, the absolute changes in log2-transformed hsTnT and NT-proBNP were associated with increased risk of S/SEE (adj-HR, 1.75; 95% CI, 1.38–2.23; p&lt;0.001, and adj-HR, 1.31; 95% CI, 1.11–1.55; p=0.002, respectively) and log2-transformed GDF-15 with bleeding (adj-HR, 1.42; 95% CI, 1.04–1.92; p=0.025). Analyzed in a categorical manner (Figure), patients who increased hsTnT or NT-proBNP between baseline and 12 months or had high hsTnT or NT-proBNP at both timepoints were at higher risk for S/SEE (adj-HR 1.87 and 1.50 for hsTnT; adj-HR 1.80 and 2.59 for NT-proBNP, respectively). Patients with persistently elevated GDF-15 appeared to be at higher risk for bleeding (adj-HR,1.35) (Figure).

Conclusions

Serial assessment of hsTnT, NT-proBNP, and GDF-15 revealed a substantial proportion of patients with AF had dynamic values. Patients with either persistently elevated or dynamic values were at higher risk of adverse clinical outcomes. Those biomarkers may play a role in personalizing preventive strategies in patients with AF based on risk.

Change in biomarkers and event rate

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Daiichi Sankyo Pharma Development

P3526Heart Failure hospitalization and mortality in non-valvular Atrial Fibrillation: The ENGAGE-AF TIMI 48 Trial

Introduction

Atrial Fibrillation (AF) is associated with increased risk of cardiovascular (CV) morbidity and mortality. Heart Failure (HF) represents the most common CV complication, more common than thromboembolic events.

Purpose

We aimed to determine clinical factors associated with HF hospitalization and mortality in a contemporary cohort of patients with AF without previous history of HF.

Methods

The Effective Anticoagulation with Factor Xa Next Generation in AF–Thrombolysis in Myocardial Infarction 48 (ENGAGE-AF TIMI 48) study tested the oral factor Xa inhibitor edoxaban in comparison with warfarin for the prevention of stroke or systemic embolism, in 21,105 patients with AF. We assessed the composite endpoint of HF hospitalization, death due to HF or sudden cardiac death in 8981 patients without a history of HF. Cox proportional hazard models were used to evaluate the significant clinical predictors associated with the endpoint of interest.

Results

Over a median follow-up of 2.8 years, 589 patients (6.5%) experienced the composite endpoint. Older patients, cardiovascular risk factors (hypertension, diabetes, heart valve disease), history of stroke and coronary artery disease, impaired renal function (ClCr ≤50 ml/min), heart rate at baseline and diuretic use were associated with increased risk of the composite endpoint (model c-statistic 0.66) (Figure 1). Outcomes were not affected by randomization to edoxaban or warfarin. In patients with available cardiac-derived biomarkers, elevated levels of both NT-proBNP and Troponin I were significantly associated with the endpoint after adjustment for the clinical predictors (Figure 1). The addition of the biomarkers to clinical predictors enhanced risk estimation (c-statistics 0.69, NRI 0.40, IDI 0.01, all p<0.001 for NT-proBNP and c-statistics 0.70, NRI 0.43, IDI 0.03, all p<0.001 for Troponin I).

Figure 1

Conclusions

HF hospitalization and mortality are important complications in AF patients without a history of HF. The addition of cardiac biomarkers to clinical characteristics enhances risk estimation. These findings may improve risk stratification.

Characterizing the skull base in craniofacial microsomia using principal component analysis

The aim of this study was to compare the anatomical differences in the skull base between the affected and non-affected side in patients with craniofacial microsomia (CFM), and to compare the affected and non-affected sides with measurements from a normal population. Three-dimensional computed tomography scans of 13 patients with unilateral CFM and 19 normal patients (age range 7-12 years) were marked manually with reliable homologous landmarks. Principal component analysis (PCA), as part of a point distribution model (PDM), was used to analyse the variability within the normal and preoperative CFM patient groups. Through analysis of the differences in the principal components calculated for the two groups, a model was created to describe the differences between CFM patients and normal age-matched controls. The PDMs were also used to describe the shape changes in the skull base between the cohorts and validated this model. Using thin-plate splines as a means of interpolation, videos were created to visualize the transformation from CFM skull to normal skull, and to display the variability in shape changes within the groups themselves. In CFM cases, the skull base showed significant asymmetry. Anatomical areas around the glenoid fossa and mastoid process showed the most asymmetry and restriction of growth, suggesting a pathology involving the first and second pharyngeal arches.

Comparison between acoustic radiation force impulse quantification data and perfusion-CT parameters in hepatocellular carcinoma

OBJECTIVE

To find out, if ultrasound elastography of hepatocellular carcinoma (HCC) can predict patterns of tumor perfusion in volume perfusion computed tomography (VPCT).

MATERIAL AND METHODS

25 consecutive patients (mean age, 68.9; range, 51-85 years) with liver cirrhosis suspected of HCC underwent VPCT and acoustic radiation force impulse (ARFI) elastography the same day. Quantitative elasticity values were registered, while blood flow (BF), blood volume (BV) and hepatic perfusion index (HPI) of the HCC lesions were calculated. Additionally, we identified histologic WHO grading, lesion size and localization. The Siemens Acuson S 3000 HELX-System with Virtual Touch™-Software and Siemens Somatom Definition Flash with Syngo^® software were used.

RESULTS

A total of 43 HCC lesions were assessed. Mean shear wave velocity was 2.6m/s (range, 1.1-4.3m/s). There was no significant linear correlation between the elasticity values and BF (p=0.751), BV (p=0.426) and HPI (p=0.437). However, elasticity values were higher, the larger the tumor was (p=0.008). Shear wave velocity declined with increasing distance of the HCC to the skin surface (p=0.028) and depending on liver segment. In addition, elasticity values were higher in less differentiated HCCs. This trend was not statistically significant (p=0.842).

CONCLUSION

Tissue elasticity in HCC does not correlate with the degree of tumor vascularization, but calculated values are influenced both by the tumor size and localization inside the liver.

Recent Scientific Evidence and Technical Developments in Cardiovascular Computed Tomography

In recent years, coronary computed tomography angiography has become an increasingly safe and noninvasive modality for the evaluation of the anatomical structure of the coronary artery tree with diagnostic benefits especially in patients with a low-to-intermediate pretest probability of disease. Currently, increasing evidence from large randomized diagnostic trials is accumulating on the diagnostic impact of computed tomography angiography for the management of patients with acute and stable chest pain syndrome. At the same time, technical advances have substantially reduced adverse effects and limiting factors, such as radiation exposure, the amount of iodinated contrast agent, and scanning time, rendering the technique appropriate for broader clinical applications. In this work, we review the latest developments in computed tomography technology and describe the scientific evidence on the use of cardiac computed tomography angiography to evaluate patients with acute and stable chest pain syndrome.

Improvements in cheek volume in lipoatrophic individuals switching away from thymidine nucleoside reverse transcriptase inhibitors

BACKGROUND

Thymidine nucleoside reverse transcriptase inhibitors (NRTIs) are associated with subcutaneous fat loss. Facial changes cannot be assessed by dual-energy X-ray absorptiometry (DEXA) scans. There are limited objective data on the reversibility of facial lipoatrophy.

METHODS

We performed a facial volume substudy of a randomized thymidine NRTI replacement study carried out in HIV-infected subjects with moderate to severe lipoatrophy. Facial volume changes were assessed using validated 3D laser imaging. Changes in body composition were measured using DEXA scans. The association between changes in facial volume and body composition parameters at 48 weeks was measured using Spearman's rank correlation.

RESULTS

Forty-seven individuals (46 male), 11 receiving zidovudine and 36 receiving stavudine, switched to either tenofovir disoproxil fumarate (DF) (n=23) or abacavir (ABC) (n=24). Thirty-nine of these 47 patients (84.8%) reported facial lipoatrophy at baseline. The median volume increase in both cheeks from baseline was 1857.3 mm(3). These volume changes and increases in limb fat at 48 weeks were similar in the two groups and correlated significantly (Spearman's r=0.41, P=0.004).

CONCLUSIONS

Facial volume in lipoatrophic individuals was found to increase after thymidine NRTI replacement. We demonstrated a significant correlation between improvements in facial and limb fat parameters. Switching from thymidine NRTIs in patients with facial lipoatrophy could potentially reduce the need for cosmetic interventions.

Overcoming subjectivity in assessing facial lipoatrophy: is there a role for three-dimensional laser scans?

BACKGROUND

Prevalence and incidence rates of lipodystrophy vary widely and frequently rely upon self- and/or clinician reports. Currently no validated assessment tool for facial lipoatrophy is available.

AIMS AND OBJECTIVES

To illustrate that assessment of the severity of facial lipoatrophy by patients and clinicians is subjective. To evaluate the reproducibility of facial three-dimensional surface laser scans.

METHODS

Twenty-three HIV-positive men were recruited from an inner London HIV outpatient clinic in September 2001. CD4 count, viral load, antiretroviral history and body mass index were recorded. Patients and clinicians independently assessed the severity of facial lipoatrophy on a four-point scale and the level agreement was measured. Seventeen of the 23 patients (73.9%) underwent two scans 1 week apart, which were then superimposed. The volume difference (mm3) and mean difference (mm) between the scans for five regions of the face were measured and compared with the self-reported grade of facial lipoatrophy.

RESULTS

For each pair of clinicians (P=0.03, 0.005 and 0.0002, respectively), and for one patient-clinician pair (P=0.004), there was a significant systematic difference between the two sets of gradings of facial lipoatrophy. The level of disagreement was generally higher for patients reporting facial lipoatrophy (n=17) compared to those not reporting it (n=6). The mean volume difference and mean difference between any region were within 200 mm3 and 0.25 mm, respectively. Reproducibility was unaffected by the self-reported grade of facial lipoatrophy.

CONCLUSIONS

Assessment of the severity of facial lipoatrophy by patients and clinicians is subjective. Three-dimensional facial laser scans are reproducible and may provide an objective tool for monitoring changes in facial lipoatrophy.

HIV-1 drug resistance profiles in children and adults with viral load of <50 copies/ml receiving combination therapy

CONTEXT

The continued release of human immunodeficiency virus type 1 (HIV-1) into plasma at very low levels during highly active antiretroviral therapy (HAART) can be detected using specialized techniques, but the nature and significance of this low-level viremia, especially as related to acquisition of drug resistance mutations, are unclear.

OBJECTIVE

To determine genetic resistance profiles of low-level plasma HIV-1 in patients with prolonged viral suppression (<50 copies/mL of plasma HIV-1 RNA) while receiving HAART.

DESIGN AND SETTING

Cross-sectional study conducted at a US academic hospital from November 1999 to February 2001 using a novel method for amplification of low levels of viral genomes in plasma.

PATIENTS

Eighteen HIV-1-infected patients (7 children and 11 adults), enrolled in a longitudinal study of HIV-1 reservoirs, who had suppression of viral replication while receiving protease inhibitor-containing combination therapy. Two patients (1 adult and 1 child) with less optimal suppression of viral replication were included to assess virus predominating when plasma HIV-1 RNA levels are low but detectable (<1000 copies/mL). Follow-up analyses were conducted in 3 patients.

MAIN OUTCOME MEASURE

Detection of drug resistance mutations in clones amplified from low-level plasma virus.

RESULTS

Viral sequences were amplified from 8 of the 18 patients with simultaneous plasma HIV-1 measurements of less than 50 copies/mL and from 2 patients with 231 and 50 copies/mL. Clones from 3 treatment-naive patients with less than 50 copies/mL of plasma HIV-1 RNA showed continued release, for as long as 42 months, of wild-type drug-sensitive virus. The 7 patients with prior nonsuppressive therapy, with viral loads below 50 copies/mL and during "blips" to 231 and 64 copies/mL, had only resistance mutations consistent with pre-HAART therapy (although reverse transcriptase inhibitor mutations may have continued to occur). New HAART-related mutations were seen in a control patient with prior viral load levels of about 400 to 1000 copies/mL. For phylogenetic analysis, sequences were available for both resting CD4(+) T cells and plasma HIV for 7 of 10 patients and showed patient-specific clustering of sequences and a close relationship between virus in the plasma and the latent reservoir.

CONCLUSIONS

Based on the samples that could be amplified, low-level viremia in children and adults receiving HAART with prolonged suppression of viremia to less than 50 copies/mL of HIV-1 RNA may result primarily from archival, pre-HAART virus, reflecting earlier treatment conditions, and does not appear to require development of new, HAART-selected mutations reflecting partial resistance to therapy. Low-level viremia below 50 copies/mL may represent less of a concern regarding impending drug failure of current HAART regimens. However, the archival drug-resistant virus may be relevant regarding future treatment strategies.

Negative priming in schizophrenia: effects of masking and prime presentation time

Beech et al. [Br. J. Clin. Psychol. 28 (1989) 109--116] previously reported attenuated negative priming in schizophrenic patients that was interpreted as a sign of dysfunctional cognitive inhibition. However, subsequent research has provided mixed results. In the present study, it was investigated whether reduced negative priming in schizophrenics may be an experimental artifact. Based on evidence from backward masking studies in schizophrenia, it was hypothesized that brief prime presentation times and pattern masking as used by Beech et al. and others may have impaired the visual perception of the prime display in schizophrenics. 20 schizophrenic patients and 20 matched healthy controls participated in the study. Subjects completed four negative priming experiments varying in prime presentation time (100 or 250 ms) and masking (a mask or a blank screen followed prime presentation). In line with prediction, reduced negative priming in schizophrenics only occurred for trials with 100 ms prime presentation time followed by a mask. Neither psychopathology nor any sociodemographic variable correlated substantially with negative priming. Results strongly suggest that reduced negative priming in schizophrenics may not be due to reduced cognitive inhibition but mirrors perceptual deficits.

Single-molecule tracking of myosins with genetically engineered amplifier domains

We combined protein engineering and single molecule measurements to directly record the step size of a series of myosin constructs with shortened and elongated artificial neck domains. Our results show that the step size has a clear linear dependence on the length of the neck domain and we also established that mechanical amplification in the myosin motor is based on a rotation of the neck domain relative to the actin-bound head. For all our constructs, including those with artificial necks, the magnitude of the neck rotation concurrent with the displacement step was approximately 30 degrees. The engineered change in the step size of myosin marks a significant advance in our ability to selectively modify the functional properties of molecular motors.

External examiners: quality assurance in nursing education

External examining is a system of quality assurance in nursing education that is quite foreign to most American nurses. The concept of an external examiner-a visiting assessor of high academic standing and possessed of integrity and objectivity-supports a notion of the universality of educational standards and justice for the individual student. Potential external examiners are appointed primarily through informal social and professional networks within educational institutions of the host country. Criteria for appointment, roles and functions of an examiner, and the four stages of the external examination process are discussed. Suggestions to facilitate each stage as well as implications for potential American external examiners are included. The manuscript concludes with insights from two American nurse educators about their experience as external examiners.

Misplacement of a femoral venous catheter into the ascending lumbar vein: repositioning using ultrasonographic guidance

A 5-week-old infant with congenital chylothorax required long-term intravenous access for parenteral nutrition. Cannulation of the inferior vena cava via the left femoral vein was attempted, but the catheter was misplaced into the left ascending lumbar vein. Catheter removal is advised when such malposition is identified. We were able successfully to redirect the catheter into the inferior vena cava using ultrasonographic guidance. This procedure has not been described previously in children. We propose that repositioning of incorrectly placed vascular catheters can be achieved using ultrasound guidance at the bedside.

Flavor authenticity studies by (2)h/(1)h ratio determination using on-line gas chromatography pyrolysis isotope ratio mass spectrometry

Based on (2)H/(1)H ratio measurements of commercial synthetic and "natural" references, the recently developed on-line gas chromatography pyrolysis isotope ratio mass spectrometry (HRGC-P-IRMS) technique was used to determine the delta(2)H(SMOW) values of the flavor compounds decanal, linalool, and linalyl acetate, as well as those of E-2-hexenal and E-2-hexenol in foods and essential oils. In preceding model studies, the influence of sample preparation steps (simultaneous distillation extraction, SDE; solvent extraction, SE; liquid liquid extraction, LLE) on the delta(2)H values was found to be negligible. For decanal, the typical (2)H abundance, with higher content of (2)H for synthetic material (delta(2)H(SMOW) from -90 to -156 per thousand) and lower (2)H content for natural references (delta(2)H(SMOW) from -138 to -262 per thousand) was observed. Although the delta(2)H data recorded for linalool did not allow one to distinguish between synthetic (delta(2)H(SMOW) from -207 to -301 per thousand) and natural (delta(2)H(SMOW) from -234 to -333 per thousand) materials, the situation was somewhat more encouraging for linalyl acetate; delta(2)H(SMOW) values from -199 to -239 per thousand and from -213 to -333 per thousand were found for synthetic and natural samples, respectively. E-2-Hexenal and E-2-hexenol showed clear-cut origin-dependent differences in their (2)H/(1)H ratios; that is, delta(2)H(SMOW) values from -14 to -109 per thousand and from -263 to -415 per thousand as well as from -41 to -131 per thousand and from -238 to -348 per thousand were recorded for products from synthetic and natural origins, respectively.

A stable latent reservoir for HIV-1 in resting CD4(+) T lymphocytes in infected children

HIV-1 persists in a latent state in resting CD4(+) T lymphocytes of infected adults despite prolonged highly active antiretroviral therapy (HAART). To determine whether a latent reservoir for HIV-1 exists in infected children, we performed a quantitative viral culture assay on highly purified resting CD4(+) T cells from 21 children with perinatally acquired infection. Replication-competent HIV-1 was recovered from all 18 children from whom sufficient cells were obtained. The frequency of latently infected resting CD4(+) T cells directly correlated with plasma virus levels, suggesting that in children with ongoing viral replication, most latently infected cells are in the labile preintegration state of latency. However, in each of 7 children who had suppression of viral replication to undetectable levels for 1-3 years on HAART, latent replication-competent HIV-1 persisted with little decay, owing to a stable reservoir of infected cells in the postintegration stage of latency. Drug-resistance mutations generated by previous nonsuppressive regimens persisted in this compartment despite more than 1 year of fully suppressive HAART, rendering untenable the idea of recycling drugs that were part of failed regimens. Thus the latent reservoir for HIV-1 in resting CD4(+) T cells will be a major obstacle to HIV-1 eradication in children.

Enhancement of pain control with ketorolac tromethamine in patients with sickle cell vaso-occlusive crisis

Twenty one patients with sickle cell disease admitted to the hospital with the pain of vaso-occlusive crisis (VOC) were treated by continuous IV infusion of ketorolac or normal saline for up to 5 days. All patients received supplemental IM injections of meperidine, 100 mg, as necessary, but not more frequently than every 3 hr. Over the 5 days the ketorolac treated patients (KT) required 33% less meperidine than did the placebo treated patients (PL), P = 0.04, and had significantly better pain relief as assessed by categorical, visual analog, and pain relief scales. By the end of 5 days infusions had been discontinued in six KT and one PL. The time to discontinuation of the infusion was significantly shorter in KT, (P = 0.009). The median duration of hospital stay from the start of treatment was 3.3 days for KT and 7.2 days for PL, P = 0.027. Adverse events were mainly related to the digestive system. This study showed that continuous infusion of ketorolac significantly reduced total meperidine requirement and that the analgesia produced by this combination was superior to that produced by meperidine alone. Further evaluation of this drug in the management of sickle cell VOC is warranted.

Structural allometry of the femur and tibia in Hominoidea and Macaca

Allometric scaling relationships between body weight, bone length, and cross-sectional dimensions of the lower limb bones which measure structural strength and rigidity (area, second moments of area) are investigated in Homo, Gorilla, Pan, Pongo, and Macaca. Cross-sectional dimensions are slightly positively allometric and highly correlated with body weight; within-bone proportional differences are largely a result of differences in relative bone length to body weight. Orangutans show the greatest deviation from general scaling relationships between lower limb bone structural strength and weight, probably due to habitual upper limb suspension. Formulas for the prediction of weight from cross-sectional dimensions are presented.