Thermography in rheumatoid arthritis: a comparison with ultrasonography and clinical joint assessment.

AIM: To compare thermography with ultrasonography and clinical joint assessment in patients with rheumatoid arthritis (RA). MATERIALS AND METHODS: Thermography and ultrasonography (power Doppler (PD) and grey-scale (GS) joint inflammation scored semi-quantitatively 0-3) were performed sequentially on both hands of 37 RA patients. Using generalised estimating equations analysis, (a) thermographic parameters (TP) were compared between joints based on their PD and GS joint inflammation positivity/negativity status, while (b) TP and ultrasound-detected joint inflammation were compared between joints categorised by their clinical swelling/tenderness status. RESULTS: Comparing PD positive versus negative joints, the differences in mean values (95% CI) for TP including maximum (Tmax), minimum (Tmin), average (Tavg), and Tmax minus Tmin (Tmax-min) temperatures (in °C) were 1.37 (0.86, 1.87), 0.91 (0.46, 1.36), 1.16 (0.67, 1.64), and 0.46 (0.28, 0.64), respectively. Comparing GS positive versus negative joints, the corresponding results for thermography were 1.09 (0.67, 1.52), 0.66 (0.32, 1.00), 0.86 (0.47, 1.26), and 0.45 (0.28, 0.62), respectively. p-Values were all <0.001. The differences in mean values (95% CI) for ultrasound scores, but not for TP, were statistically significant for (a) swollen tender joints (PD: 0.67 [0.39, 0.96], p<0.001; GS: 0.86 [0.54, 1.18], p<0.001) and (b) swollen non-tender joints (PD: 0.46 [0.07, 0.84], p=0.021; GS: 0.83 [0.37, 1.29], p<0.001) when compared to non-swollen non-tender joints. CONCLUSION: Joints in RA patients have significantly higher temperature readings when ultrasound-detected joint inflammation is present. Swollen tender/non-tender joints exhibited a greater degree of ultrasound-detected joint inflammation than non-swollen non-tender joints, although their temperature readings were not significantly higher.

Common variants of catechol-O-methyltransferase influence patient-controlled analgesia usage and postoperative pain in patients undergoing total hysterectomy.

Catechol-O-methyltransferase (COMT) gene polymorphisms and haplotypes have been associated with both experimental and clinical pain phenotypes. In this prospective study, we investigated the association of three common polymorphisms with experimentally induced pressure pain, postoperative pain and amount of self-administered morphine in 973 patients who underwent scheduled total hysterectomy. DNA extracted from peripheral blood was genotyped for three COMT polymorphisms by Taqman assay or a PCR-based method. In the overall sample, rs4633 and rs4680 were significantly associated with morphine use, whereas rs4818 was associated with time-averaged pain scores. Statistically significant associations were found between COMT rs4633 and rs4680 genotypes and the amount of morphine self-administered through a patient-controlled analgesia pump. For rs4818, the only statistically significant association was with time-averaged pain scores. Haplotype analysis showed statistically significant association of the low pain sensitivity haplotype with time-averaged pain scores; and average pain sensitivity haplotype with total morphine and weight-adjusted morphine.

Psychiatric manifestations as initial presentation for pediatric CNS germ cell tumors, a case series.

BACKGROUND: Central nervous system (CNS) germ cell tumors account for 3 % of all pediatric brain tumors in the USA. Presenting symptoms are typically location based with pineal tumors presenting with obstructive hydrocephalus and suprasellar tumors with hypothalamic/pituitary dysfunction and ophthalmologic abnormalities. Psychiatric manifestations such as psychosis and behavioral changes are atypical presentations of CNS germ cell tumors, with only 11 previously reported cases. METHODS: This is a retrospective case series describing patients with CNS germ cell tumors with an atypical presentation including psychiatric manifestations. Information regarding clinical presentation, treatment course, and outcome were obtained. RESULTS: We report seven patients who presented with psychiatric symptoms consisting of psychomotor delay as well as behavioral and mood changes. Six of the seven patients were diagnosed ≥6 months after onset of psychiatric symptoms. All of the seven are alive but five continue to have neurologic and psychiatric issues post treatment. CONCLUSIONS: Atypical presentations of CNS germ cell tumors can delay diagnosis and treatment and may be secondary to atypical locations as well as endocrine dysfunction manifesting as psychiatric symptoms. Delayed diagnosis did not appear to affect survival but earlier diagnosis may potentially be associated with better neurologic and psychiatric outcome. Patients who present with these symptoms and atypical neuroimaging should have a thorough evaluation for CNS germ cell tumors including serum and CSF markers. Clinicians should be aware of these less common presentations to aid in prompt diagnosis and treatment.

Association between body mass index and risk of total knee replacement, the Singapore Chinese Health Study.

PURPOSE: Data on the association between body mass index (BMI) and risk of knee osteoarthritis (KOA) are sparse for Asian populations who are leaner than Western populations. We evaluated the association between BMI and risk of total knee replacement (TKR) due to severe KOA among Chinese in Singapore. METHODS: We used data from the Singapore Chinese Health Study (SCHS), a population-based prospective cohort of 63,257 Chinese men and women, aged 45-74 years at enrollment from 1993 to 1998. Information on height, weight, diet and lifestyle factors were obtained via in-person interviews. TKR cases for severe KOA were identified via linkage with the nationwide hospital discharge database through 2011. Cox regression and weighted least squares regression were used in the analysis. RESULTS: The mean BMI among cohort participants was 23.1 kg/m(2), and more than two-thirds had BMI below 25 kg/m(2). A total of 1649 had TKR attributable to severe KOA. Risk of TKR increased in a strong dose-dependent manner with increasing BMI throughout the 15-32 kg/m(2) range and became less clear at BMI >32 kg/m(2). In the BMI range 16-27 kg/m(2), there was a 27% increase in TKR risk for each unit increase in BMI (P for trend < 0.001). Compared to BMI 19-20 kg/m(2), the risk estimates of TKR were all statistically significant with increasing unit of BMI ≥21 kg/m(2). Results were similar for men and women. CONCLUSION: Our results provided evidence for a constant mechanical mechanism underlying BMI and KOA initiation and/or progression.

Clinical evolution of Parkinson's disease and prognostic factors affecting motor progression: 9-year follow-up study.

BACKGROUND AND PURPOSE: There have been few long-term studies that have characterized and charted the clinical progression of Parkinson's disease (PD). This study was therefore undertaken to understand the natural clinical evolution of treated PD patients and to identify the variables that predict greater progression in these patients. METHODS: A longitudinal linear mixed model analysis of motor score progression was performed on 576 PD patients derived from the National Neuroscience Institute Movement Disorders Database. Clinical and demographic variables were taken at baseline and formed the subgroups for comparison (gender, age at diagnosis, subtype, Mini-Mental State Examination score and baseline motor score). Motor score progression was calculated at each patient follow-up time point as the difference between Unified Parkinson's Disease Rating Scale (UPDRS) motor score at baseline and follow-up scores. RESULTS: The overall annual motor score progression as measured by the change of UPDRS motor scores from baseline ranged from 0.62% to 3.67%. There are three distinct phases: improvement, stability, and steady progression. Patients returned to baseline score 2-2.5 years after diagnosis, with stability lasting to 7 years, followed by a period of steady progression. When analyzed longitudinally, male gender (P < 0.03), older age at diagnosis (P < 0.05), akinetic-rigid subtype (P < 0.04), cognitive impairment (P < 0.005) and lower baseline motor score (P < 0.04) were associated with greater progression of motor scores. CONCLUSIONS: Our results show that, when measured clinically, motor progression was non-linear and that it occurred in distinct phases, all of which were affected by baseline demographic and clinical variables such as gender, age at diagnosis, disease subtype, cognitive status and baseline motor score.

A comparison of single-dose dexmedetomidine or propofol on the incidence of emergence delirium in children undergoing general anaesthesia for magnetic resonance imaging.

Emergence delirium is a significant problem in children regaining consciousness following general anaesthesia. We compared the emergence characteristics of 120 patients randomly assigned to receive a single intravenous dose of dexmedetomidine 0.3 µg.kg(-1) , propofol 1 mg.kg(-1) , or 10 ml saline 0.9% before emerging from general anaesthesia following a magnetic resonance imaging scan. Emergence delirium was diagnosed as a score of 10 or more on the Paediatric Anaesthesia Emergence Delirium scale. The incidence of emergence delirium was 42.5% in the dexmedetomidine group, 33.3% in the propofol group and 41.5% in the saline group (p = 0.671). Three patients in the dexmedetomidine group, none in the propofol group and two in the saline group required pharmacological intervention for emergence delirium (p = 0.202). Administration of neither dexmedetomidine nor propofol significantly reduced the incidence, or severity, of emergence delirium. The only significant predictor for emergence delirium was the time taken to awaken from general anaesthesia, with every minute increase in wake-up time reducing the odds of emergence delirium by 7%.

Mortality of bullous pemphigoid in Singapore: risk factors and causes of death in 359 patients seen at the National Skin Centre.

BACKGROUND: Bullous pemphigoid (BP) is the most common autoimmune-mediated subepidermal blistering skin disease and is associated with significant morbidity and mortality. OBJECTIVES: To determine the 3-year mortality rate, risk factors and causes of death in patients with BP in Singapore, compared with the general population. METHODS: We conducted a retrospective cohort study of all newly diagnosed patients with BP seen at the National Skin Centre from 1 April 2004 to 31 December 2009. Demographic and clinical data on comorbidities and treatment were recorded. Mortality information was obtained from the National Registry of Diseases. RESULTS: In total 359 patients were included in our study. The 1-, 2-, 3-year mortality rates were 26·7%, 38·4% and 45·7%, respectively. The 3-year standardized mortality risk for patients with BP was 2·74 (95% confidence interval 2·34-3·19) times higher than for the age- and sex-matched general population. Parkinson disease, heart failure and chronic renal disease were associated with increased mortality, while combination treatment with low-to-moderate-dose corticoste-roids and immunomodulatory agents such as doxycycline and/or nicotinamide was associated with lower mortality. Overall, infections were the most common cause of death (59·8%), with the main causes of death being pneumonia (42·7%), cardiovascular disease (14·6%) and stroke (11·6%). CONCLUSIONS: This study confirms an increased 3-year mortality rate for patients with BP in Singapore. Risk factors for increased mortality include medical comorbidities, especially neurological, cardiac and renal diseases. Treatment with combination therapy, including the use of low-to-moderate-dose corticosteroid, appeared to decrease mortality risk in patients with BP.

Systematic review of outcomes of liver resection for early hepatocellular carcinoma within the Milan criteria.

BACKGROUND: Long-term overall survival after liver resection in patients with hepatocellular carcinoma (HCC) within the Milan criteria has been reported to improve in recent years. This study systematically reviewed the outcomes of surgical resection for HCC in patients with good liver function and meeting the Milan criteria for early HCC, published in the past 10 years. METHODS: A literature search was conducted in PubMed for papers on outcomes of surgical resection for HCC published between January 2000 and December 2010. Cochrane systematic review methodology was used for this review. The primary outcome was overall survival. Secondary outcomes included operative mortality and disease-free survival. Studies that focused on geriatric populations, paediatric populations, a subset of the Milan criteria (such solitary tumours) or included patients with incidental tumours were excluded, as were case reports, conference abstracts, and studies with a large proportion of Child-Pugh grade C liver cirrhosis or unknown Child-Pugh status. RESULTS: Of 152 studies reviewed, two randomized clinical trials and 27 retrospective case series were eligible for inclusion. The 5-year overall survival rate after resection of HCC ranged from 27 to 81 (median 67) per cent, and the median disease-free survival rate from 21 to 57 (median 37) per cent. There was a trend towards improved overall survival in recent years. The operative mortality rate ranged from 0 to 5 (median 0·7) per cent. CONCLUSION: Surgical resection offers good overall survival for patients with HCC within the Milan criteria and with good liver function, although recurrence rates remain high. Outcomes have tended to improve in more recent years.

Accuracy of parent-reported ages and stages questionnaire in assessing the motor and language skills of preterm infants.

BACKGROUND: Parent-completed tools like the Ages and Stages Questionnaire Third Edition (ASQ-3) are important in developmental screening. As a screening tool, a high negative predictive value (NPV) is critical to avoid missing the diagnosis of developmental delay. This study evaluated the NPV and accuracy of the ASQ-3 in assessing the development of preterm infants. METHODS: Infants born at <32 weeks and/or <1250 grams, presenting to the Neonatal Neurodevelopmental Clinic at the Singapore General Hospital for follow-up from January 2014 to June 2017, at 6, 12, and 18 months corrected age, were included. The ASQ-3 and standardized tests - Peabody Developmental Motor Scale-Second Edition (PDMS-2) and Preschool Language Scale, Fourth Edition UK (PLS-4 UK) - were administered. ASQ-3 gross motor and fine motor scores were compared to PDMS-2 at 6 and 12 months, and ASQ-3 communication scores to PLS-4 UK at 18 months. RESULTS: At 6 months (n = 145), NPV for gross motor and fine motor were 96.4% (accuracy 80.0%) and 95.4% (accuracy 77.2%) respectively. At 12 months (n = 127), NPV for gross motor and fine motor were 88.9% (accuracy 79.8%) and 82.8% (accuracy 74.0%) respectively. At 18 months (n = 113), NPV for language was 56.9% (accuracy 63.7%). CONCLUSIONS: The ASQ-3 showed high NPV and accuracy in screening gross motor and fine motor skills at 6 and 12 months, but not in screening language skills at 18 months. Judicious use of the ASQ-3 may allow for more effective utilization of resources.

Improvement in quality of life among Sri Lankan patients with haemorrhoids after invasive treatment: a longitudinal observational study.

BACKGROUND: Haemorrhoids is a common chronic disease that can significantly impact patients' quality of life. Yet, few studies have evaluated health-related quality of life (HRQoL) of patients with haemorrhoids before and after treatment. This study investigated the HRQoL of patients with haemorrhoids before and after treatment and the change in HRQoL from baseline. METHODS: A prospective observational study of patients with haemorrhoids was conducted at two public hospitals in Kandy, Sri Lanka. Two questionnaires assessing symptom severity and haemorrhoid-specific QoL were administered at initial consultation and at 4- and 8-week follow-ups after treatment (sclerotherapy, rubber band ligation (RBL), haemorrhoidectomy or evacuation of haematoma). The primary outcome was the least squares (LS) change of HRQoL score from baseline, measured using the Short Health Scale adapted for Haemorrhoidal Disease (4 domains: symptom load, interference with daily activities, concern, general well-being). RESULTS: In 48 patients selected for this study, LS mean change from baseline showed significant improvement in HRQoL across all domains and total Short Health Scale adapted for Haemorrhoidal Disease score at 4- and 8-week follow-ups (P < 0.001). Difference in LS mean change from baseline also showed continued improvement of HRQoL from week 4 to week 8 (P < 0.010). 'Concern' showed greatest improvement at 4 and 8 weeks (P < 0.001). Averaged LS mean changes from baseline showed RBL had greater improvement of HRQoL compared with sclerotherapy (P = 0.004). CONCLUSION: Patients with haemorrhoids had improved HRQoL after invasive treatment. Haemorrhoid-specific QoL is an important component of the extent of disease and can serve as an aid to guide treatment, assess outcomes and monitor disease.

Determining competence in performing obstetric combined spinal-epidural procedures in junior anesthesiology residents: results from a cumulative sum analysis.

BACKGROUND: The epidural anesthesia technique is a challenging skill to master. The Accreditation Council for Graduate Medical Education (ACGME) stipulates that anesthesiology residents must complete 40 epidural procedures by the end of junior residency. The rationale is unknown. The aim of this prospective study was to determine the minimum case experience required to demonstrate competence in performing obstetric combined spinal-epidural procedures among junior residents, using an objective statistical tool, the cumulative sum (CUSUM) analysis. METHODS: Twenty-four residents, with no prior experience performing epidurals, sequentially recorded all obstetric combined spinal-epidural procedures as a 'success' or 'failure', based on study criteria. Individual CUSUM graphs were plotted, with acceptable and unacceptable failure rates set at 20% and 35%, respectively. The number of procedural attempts necessary to demonstrate competence was determined. RESULTS: Twenty-four residents (mean (SD) age 29 (2) years) participated in the study. Median (IQR) number of procedures was 78 (66-85), with a median (IQR) success rate of 86% (82-89%). Nineteen of 24 residents required a median (IQR) of 40 (33-50) attempts to demonstrate competence. Five did not achieve procedural competence in the training period. The CUSUM graphs highlighted performance trends that required intervention. CONCLUSION: Competence was achieved by 19/24 residents after the ACGME-required case experience of 40 combined spinal-epidural procedures, based on a predefined acceptable failure rate of 20%. In our experience, CUSUM analysis is useful in monitoring technical performance over time and should be included as an adjunct assessment method for determining procedural competence.

The Health Opportunity Index: Understanding the Input to Disparate Health Outcomes in Vulnerable and High-Risk Census Tracts.

The Health Opportunity Index (HOI) is a multivariate tool that can be more efficiently used to identify and understand the interplay of complex social determinants of health (SDH) at the census tract level that influences the ability to achieve optimal health. The derivation of the HOI utilizes the data-reduction technique of principal component analysis to determine the impact of SDH on optimal health at lower census geographies. In the midst of persistent health disparities and the present COVID-19 pandemic, we demonstrate the potential utility of using 13-input variables to derive a composite metric of health (HOI) score as a means to assist in the identification of the most vulnerable communities during the current pandemic. Using GIS mapping technology, health opportunity indices were layered by counties in Ohio to highlight differences by census tract. Collectively we demonstrate that our HOI framework, principal component analysis and convergence analysis methodology coalesce to provide results supporting the utility of this framework in the three largest counties in Ohio: Franklin (Columbus), Cuyahoga (Cleveland), and Hamilton (Cincinnati). The results in this study identified census tracts that were also synonymous with communities that were at risk for disparate COVID-19 related health outcomes. In this regard, convergence analyses facilitated identification of census tracts where different disparate health outcomes co-exist at the worst levels. Our results suggest that effective use of the HOI composite score and subcomponent scores to identify specific SDH can guide mitigation/intervention practices, thus creating the potential for better targeting of mitigation and intervention strategies for vulnerable communities, such as during the current pandemic.

Renal concentrating mechanism: possible role for sodium-potassium activated adenosine triphosphatase.

Sodium-potassium activated adenosine triphosphatase activity was found to be almost twice as high in renal medulla as in cortex. Infusion of digoxin, a specific inhibitor of the enzyme, into one renal artery of the dog resulted in unilateral natriuresis, impaired concentrating capacity, and reduction of the enzyme activity in both cortex and medulla. It is suggested that the sodium-potassium adenosine triphosphatase plays an important role in urine concentration mechanisms.

Periprosthetic Fractures after Total Knee Arthroplasty: the Influence of Pre-Operative Mechanical Factors versus Intraoperative Factors.

Introduction: Periprosthetic fractures are a devastating complication following total knee arthroplasty. Little is known about the effect of mechanical factors on the incidence of periprosthetic fractures. The aim of this study was to examine the correlation between pre-operative mechanical factors, like side of surgery, coronal alignment and pre-operative range of motion and intra-operative factors, and the incidence of a periprosthetic fracture, following primary total knee arthroplasty (TKA). Materials and Methods: Forty-two patients with periprosthetic fractures (PPF) after primary TKA were identified from our hospital arthroplasty registry. These patients were matched two-to-one for gender and age at primary knee arthroplasty to 84 patients without PPF. The incidence of periprosthetic fracture with regards to laterality, coronal alignment and pre-operative range of motion was analysed. Intra-operative factors like implant type, patellar resurfacing and notching were also analysed using logistic regression. Results: Coronal alignment, pre-operative range of motion and patella resurfacing were not significant predictors of periprosthetic fractures. Anterior femoral notching was found to be significantly higher in the fracture group with an odds ratio of 17. Left sided surgery was also significantly higher in the periprosthetic fracture group. Conclusion: Periprosthetic fractures are 17 times more likely to occur in a knee with anterior femoral notching. Preoperative factors like coronal alignment and poor preoperative range of motion do not seem to increase the risk of periprosthetic fractures after TKA.

The effect of retained intramedullary nails on tibial bone mineral density.

BACKGROUND: Intramedullary nailing has become a standard treatment for adult tibial shaft fractures. Retained intramedullary nails have been associated with stress shielding, although their long-term effect on decreasing tibial bone mineral density is currently unclear. The purpose of this study was to determine if retained tibial intramedullary nails decrease tibial mineral density in patients with successfully treated fractures. METHODS: Patients treated with statically locked intramedullary nails for isolated, unilateral tibia shaft fractures were studied. Inclusion required that fracture had healed radiographically and that the patient returned to the pre-injury activity level. Data on patient demographic, fracture type, surgical technique, implant, and post-operative functional status were tabulated. Dual energy X-ray absorptiometry was used to measure bone mineral density in selected regions of the affected tibia and the contralateral intact tibia. Image reconstruction software was employed to ensure symmetry of the studied regions. FINDINGS: Twenty patients (mean age 43; range 22-77 years) were studied at a mean of 29 months (range 5-60 months) following intramedullary nailing. There was statistically significant reduction of mean bone mineral density in tibiae with retained intramedullary nails (1.02 g/cm(2) versus 1.06 g/cm(2); P=0.04). A significantly greater decrease in bone mineral density was detected in the reamed versus non-reamed tibiae (-7% versus +6%, respectively; P<0.05). INTERPRETATION: The present study demonstrates a small, but statistically significant overall bone mineral density decrease in healed tibiae with retained nails. Intramedullary reaming appears to be a factor potentiating the reduction of tibia bone mineral density in long-term nail retention.

A physiologic differentiation between delayed and immediate hypersensitivity.

Studies have been made of movement of various macromolecules into and out of the pleural space of guinea pigs during the course of a delayed hypersensitivity reaction to purified protein derivative (PPD), and a passively transferred immediate hypersensitivity reaction to ovalbumin. While the immediate hypersensitivity reaction transiently alters vascular permeability as shown by increased movement of macromolecules into the chest, the delayed hypersensitivity reaction is marked by a decreased capacity to resorb macromolecules from the pleural space. The data suggest that the two hypersensitivity reactions may be distinguished by these physiologic differences. Additional data from studies of a chemically induced pleural effusion in these animals suggest that some type of outflow obstruction is necessary for the development of effusion, but that the outflow defect caused by the irritating chemical is based on a different mechanism than that seen during the delayed hypersensitivity reaction.

Renal sodium-potassium-activated adenosine triphosphatase and sodium reabsorption.

The role of renal Na(+),K(+)-ATPase in sodium reabsorption was further examined in dogs in which digoxin, a specific inhibitor of the enzyme system, was infused into one renal artery in doses ranging from 0.4 to 0.9 mug/kg/min (low dose) and from 1.0 to 4.0 mug/kg/min (high dose). A significant natriuresis occurred with both dose ranges which was accompanied by inhibition of Na(+),K(+)-ATPase of cortex and medulla in the infused kidney. Despite over 90% enzyme inhibition in many experiments, at least 80% of the filtered sodium continued to be reabsorbed. The per cent change in enzyme activity correlated with the rate of digoxin administration and the total dose administered but not with changes in sodium excretion. Changes in medullary Na(+),K(+)-ATPase activity, however, bore a direct relationship to alterations in fractional solute free water reabsorption (T(c) (H2O)). Inhibition of cortical enzyme activity alone was not associated with natriuresis, suggesting that medullary enzyme activity must be depressed for increased sodium excretion to occur during digoxin infusion. In high-dose experiments, significant inhibition of cortical and medullary enzyme in the contralateral control kidney was also observed, but natriuresis did not occur. In these experiments the rate at which digoxin reached the control kidney rose progressively but never equaled the rates in the directly infused kidney with either dose. Nevertheless, it is clear that under certain circumstances enzyme inhibition of either cortex or medulla need not be accompanied by natriuresis. We conclude that the major role of renal Na(+),K(+)-ATPase is in sodium reabsorption in the medulla (ascending limb of Henle's loop) and that it has a relatively small role in proximal sodium reabsorption. The kidney can rely on other sodium reabsorptive mechanisms depending on the rate of enzyme inhibition, so that natriuresis may not occur at all if depression in activity occurs "slowly." The nature of these mechanisms is not clear.

Migration of brain tumor cells on extracellular matrix proteins in vitro correlates with tumor type and grade and involves alphaV and beta1 integrins.

An important contributor to the malignancy of brain tumors is their ability to infiltrate the brain. Extracellular matrix molecules and cell adhesion molecules on cell surfaces play key roles in cell migration. In the present study, we used reaggregates of dissociated cells from freshly excised human brain tumors to analyze the migration of cells from human brain tumors of different types and grades on many different adhesion proteins adsorbed to glass substrates. Proteins were chosen based on their presence in normal or neoplastic nervous tissue, and included the extra-cellular matrix molecules fibronectin, collagens, fibrinogen, laminin, tenascin-C, thrombospondin, and the neuron-glia cell adhesion molecule, Ng-CAM. Cells from astrocytomas (n = 24) migrated on a variety of substrates, in contrast to cells from primitive neuroectodermal tumors cells (n=6), which only migrated well on laminin, fibronectin, or type IV collagen but not on the other substrates. Typically, migrating cells from astrocytomas of all grades had long, slender processes, were usually bipolar, and their cell bodies did not spread well on any substrate. Although there was variability in the migration of cells from astrocytomas of the same grade, cells from high-grade astrocytomas tended to migrate more extensively (42.3 +/- 4.7 micrometers/16 h: n = 16) than cells from lower grade astrocytomas (28.9 +/- 3.9 micrometers/16 h; P = 0.07; n = 8); the most striking differences were observed for collagen substrates, on which cells from lower grade astrocytomas migrated at very low levels (7.6 +/- 2 .6 micrometers/16 h) and cells from high-grade astrocytomas at higher levels (24.4 +/- 5.2 micrometers;P = 0.01). In contrast to primary cells from glioblastomas (n = 13), glioblastoma cell lines (n = 10) consistently spread on various substrates and migrated at high levels (69.5 +/- 7.6 versus 46.4 +/-5.7 micrometers/16 h; P = 0.03), in particular, on collagens (108.4 +/- 20.2 versus 28.0 +/- 6.1 micrometers/16 h; P= 0.001). Specific monoclonal antibodies to alphaV and beta1 integrin monomers completely inhibited the migration of astrocytoma cells on most substrates, suggesting that alphaV and beta1 integrins play a crucial role in brain tumor infiltration. These studies also suggest that although a large number of extracellular matrix molecules may promote tumor cell migration, disrupting the function of only a few tumor cell receptors may be critical for tumor infiltration in the brain.

Tenascin-C expression by angiogenic vessels in human astrocytomas and by human brain endothelial cells in vitro.

The expression of the extracellular matrix glycoprotein tenascin-C (TN) is enhanced in human astrocytomas and correlates with angiogenesis. To determine whether vascular cells are able to synthesize TN, we investigated the expression of TN protein and mRNA in nine astrocytomas. Immunogold electron microscopy in two glioblastomas multiforme detected the presence of TN in an extracellular perivascular location and to a lesser extent among tumor cells, confirming light microscopy immunohistochemical findings. In situ hybridization of astrocytomas using a digoxigenin-labeled antisense riboprobe detected strong staining for TN mRNA in vascular cells, especially in hyperplastic vessels, including those at the invasive edge of the tumors but not in vessels of normal brains. We observed weaker staining in tumor cells indicating a higher level of TN mRNA in vascular than in tumor cells. No staining was detected with the sense probe. Moreover, we investigated the ability of human brain microvessel endothelial cells (HBMECs) in primary culture to synthesize TN in vitro. Western blot analysis of the culture supernatants from HBMECs detected large amounts of TN. Immunogold silver staining demonstrated the presence of TN on the surface of HBMECs and in the subendothelial matrix. The distribution of TN mRNA in vascular cells of astrocytomas and the ability of HBMECs to synthesize TN in vitro demonstrate that vascular cells, including endothelial cells, are a major source of TN associated with angiogenesis. Furthermore, our results suggest that TN expression may be associated with endothelial cell activation and may play an important role in angiogenesis.