Molecular determinants of response to PI3K/akt/mTOR and KRAS pathways inhibitors in NSCLC cell lines

Despite the impressive results obtained in the preclinical setting, all the inhibitors targeting two central cascades in cancer, the PI3K/akt/mTOR and the KRAS/MEK/ERK pathways, have shown, apart from very few exceptions, disappointing efficacy when translated to the clinic. One of the main reasons of their clinical failure seems to be the lack of a clear molecular determinant of response to these drugs. In this study, we tried to address this point by evaluating the cytotoxic activity of different inhibitors targeting the two pathways at different levels in a panel of ten NSCLC cell lines harboring alterations in PI3K, KRAS or both. We were not able to highlight a correlation between the presence of KRAS and PI3K mutations and a specific sensitivity to the different drugs used. Molecular analyses performed after equimolar treatments showed that, independently from the entity of the response, the drugs are able to modulate the activation of their targets. Interestingly, we found that p53 mutational status separates the cell lines according to their sensitivity to PI3K pathway inhibitors treatments. The alterations considered in the PI3K/akt/mTOR and in the KRAS/MEK/ERK pathways in the different NSCLC cell lines are not sufficient to drive treatment choice but rather p53 status is a potential biomarker for the activity of this class of drugs.

LKB1 Deficiency Renders NSCLC Cells Sensitive to ERK Inhibitors

INTRODUCTION

Serine/threonine kinase 11 (LKB1/STK11) is one of the most mutated genes in NSCLC accounting for approximately one-third of cases and its activity is impaired in approximately half of KRAS-mutated NSCLC. At present, these patients cannot benefit from any specific therapy.

METHODS

Through CRISPR/Cas9 technology, we systematically deleted LKB1 in both wild-type (WT) and KRAS-mutated human NSCLC cells. By using these isogenic systems together with genetically engineered mouse models we investigated the cell response to ERK inhibitors both in vitro and in vivo.

RESULTS

In all the systems used here, the loss of LKB1 creates vulnerability and renders these cells particularly sensitive to ERK inhibitors both in vitro and in vivo. The same cells expressing a WT LKB1 poorly respond to these drugs. At the molecular level, in the absence of LKB1, ERK inhibitors induced a marked inhibition of p90 ribosomal S6 kinase activation, which in turn abolished S6 protein activation, promoting the cytotoxic effect.

CONCLUSIONS

This work shows that ERK inhibitors are effective in LKB1 and LKB1/KRAS-mutated tumors, thus offering a therapeutic strategy for this prognostically unfavorable subgroup of patients. Because ERK inhibitors are already in clinical development, our findings could be easily translatable to the clinic. Importantly, the lack of effect in cells expressing WT LKB1, predicts that treatment of LKB1-mutated tumors with ERK inhibitors should have a favorable toxicity profile.

Generation and characterization of MEK and ERK inhibitors- resistant non-small-cells-lung-cancer (NSCLC) cells

BACKGROUND

The RAS/RAF/MEK/ERK pathway is one of the most downregulated pathway in cancer. Inhibitors of RAF and MEK have established clinical use while ERK inhibitors recently faced the clinic. We aimed to generate resistant cell lines which could be helpful for defining new combinations able to overcome resistance.

METHODS

the human NSCLC cell line NCI-H727, sensitive to both MEK and ERK inhibitors, was treated with increasing concentrations of MEK162 (as MEK inhibitor) or SCH772984 as ERK inhibitor.

RESULTS

we successfully obtained a MEK resistant subline (H727/MEK, after 40 passages) as well as an ERK resistant subline (H727/SCH, after 18 passages). The two resistant sublines H727/MEK and H727/SCH were cross-resistant to ERK and MEK inhibitors, respectively, but not to RAF inhibitors. The sublines maintained the responsiveness to inhibitors of the parallel PI3K/akt/mTOR pathway as well as to agents with different mechanism of action. Mechanistically, treatment of sensitive and resistant cells with MEK or ERK inhibitors was able to induce a similar inhibition of ERK phosphorylation, while only in parental cells the drugs were able to induce a downregulation of S6 and RSK phosphorylation.

CONCLUSIONS

these resistant cells represent an important tool for further studies on the mechanisms of resistance and ways to overcome it.

Wee1 inhibitor MK1775 sensitizes KRAS mutated NSCLC cells to sorafenib

Non-Small-Cell Lung Cancer (NSCLC) is a poorly chemosensitive tumor and targeted therapies are only used for about 15% of patients where a specific driving and druggable lesion is observed (EGFR, ALK, ROS). KRAS is one of the most frequently mutated genes in NSCLC and patients harboring these mutations do not benefit from specific treatments. Sorafenib, a multi-target tyrosine kinase inhibitor, was proposed as a potentially active drug in KRAS-mutated NSCLC patients, but clinical trials results were not conclusive. Here we show that the NSCLC cells’ response to sorafenib depends on the type of KRAS mutation. KRAS G12V cells respond less to sorafenib than the wild-type counterpart, in vitro and in vivo. To overcome this resistance, we used high-throughput screening with a siRNA library directed against 719 human kinases, and Wee1 was selected as a sorafenib response modulator. Inhibition of Wee1 by its specific inhibitor MK1775 in combination with sorafenib restored the KRAS mutated cells’ response to the multi-target tyrosine kinase inhibitor. This combination of the Wee1 inhibitor with sorafenib, if confirmed in models with different genetic backgrounds, might be worth investigating further as a new strategy for KRAS mutated NSCLC.

Activity of Pan-Class I Isoform PI3K/mTOR Inhibitor PF-05212384 in Combination with Crizotinib in Ovarian Cancer Xenografts and PDX

The Phosphatidyl inositol-3 kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) and c-Met signaling pathways are often deregulated in cancer. The two pathways are interconnected and at least c-Met has been implicated in drug resistance. The aim of the study was to assess in ovarian cancer preclinical models, the efficacy and tolerability of a dual PI3K mTOR inhibitor (PF-05212384 or gedatolisib) and a c-Met inhibitor (crizotinib) either as single agents or in combination. In vitro, both PF-05212384 and crizotinib showed a concentration dependent activity in the two ovarian cancer cell lines. The combination of the two did not result in synergistic activity. A subline resistant to gedatolisib was obtained and showed an increased expression of MDR-1 gene. In vivo results show that crizotinib alone did not display any activity in all the tumors investigated, while PF-05212384 alone had some marginal activity. The combination of the two resulted in all the experiments superior to single agents with a good tolerability. Considering that crizotinib did not show activity in the models used, the results indicate that crizotinib is able to potentiate the activity of PF-05212384. Although the activity of the combination was not striking in these three models of ovarian cancer, due to the good tolerability of the combination, the results would suggest the possibility to combine the two drugs in settings in which gedatolisib or crizotinib alone have already some significant activity.

Relationship between Reduced BCL-2 Expression in Circulating Mononuclear Cells and Early Nephropathy in Type 1 Diabetes

Microalbuminuria is the earliest clinical evidence of diabetic nephropathy, but the mechanisms linking hyperglycemia and kidney complications are not clear. The aim of this study was to evaluate whether enhanced oxidative stress in patients with microalbuminuria can contribute to diabetic nephropathy development through downregulation of the antiapoptotic gene Bcl-2 that promotes in turn a pro-inflammatory status. We studied 30 patients with type 1 diabetes (15 with and 15 without microalbuminuria) compared to 15 matched healthy controls. Plasma oxidant status, and expression of Bcl-2, activated NF-kB, inducible Nitric Oxide synthase (iNOS), and monocyte chemoattractant protein (MCP)-1 in circulating monocytes were evaluated at baseline and after 8-week oral vitamin E treatment (600 mg b.i.d.). Bcl-2 expression was significantly reduced in microalbuminuric diabetic patients as a consequence of increased oxidant burden secondary to persistent hyperglycemia. Bcl-2 down-regulation was associated with enhanced expression of NF-kB, iNOS and MCP-1, and showed a strong correlation with the albumin excretion rate. Low Bcl-2 expression and high inflammatory status were normalized by vitamin E both in vivo and in vitro. Our study showed that Bcl-2 down-regulation in diabetic patients with poor glycemic control results in the activation of the NF-kB pathway leading to the development of nephropathy. Vitamin E might provide a novel form of therapy for prevention of nephropathy in diabetic patients in which an acceptable glycemic control is difficult to achieve despite insulin therapy.

Enhanced soluble CD40 ligand contributes to endothelial cell dysfunction in vitro and monocyte activation in patients with diabetes mellitus: effect of improved metabolic control

AIMS/HYPOTHESIS

Inflammation plays a pathogenic role in the development of accelerated atherosclerosis in diabetes. Soluble CD40 ligand (sCD40L) is enhanced in diabetes; however, the molecular mechanisms linking sCD40L to accelerated atherosclerosis in diabetes are still unclear. We tested the hypothesis that sCD40L may be involved in the vascular complications in diabetes and exerts its effect by triggering inflammatory reactions on mononuclear and endothelial cells (ECs).

METHODS

We studied 70 patients, 40 with type 2 and 30 with type 1 diabetes, with a history or physical examination negative for cardiovascular disease, and 40 non-diabetic and 30 healthy subjects, matched with the type 2 and type 1 diabetic patients, respectively. Plasma and serum sCD40L, and plasma soluble intercellular adhesion molecule-1, soluble vascular cell adhesion molecule-1, E-selectin and monocyte chemo-attractant protein-1 (MCP-1) were measured. Adhesion molecules and MCP-1 release, the ability to repair an injury in ECs, and O2- generation in monocytes were analysed in vitro after stimulation with serum from patients or controls.

RESULTS

Type 2 and type 1 diabetic patients had significantly higher sCD40L levels than controls. Furthermore, high sCD40L was associated with in vitro adhesion molecules and MCP-1 release, impaired migration in ECs and enhanced O2- generation in monocytes. Improved metabolic control was associated with a reduction of plasma sCD40L by 37.5% in 12 type 1 diabetic patients. Furthermore, elevated sCD40L in diabetic patients was significantly correlated with HbA1c levels.

CONCLUSIONS/INTERPRETATION

Upregulation of sCD40L as a consequence of persistent hyperglycaemia in diabetic patients results in EC activation and monocyte recruitment to the arterial wall, possibly contributing to accelerated atherosclerosis development in diabetes.

High preprocedural non-HDL cholesterol is associated with enhanced oxidative stress and monocyte activation after coronary angioplasty: possible implications in restenosis

OBJECTIVE

To investigate whether enhanced oxidant stress in patients undergoing percutaneous transluminal coronary angioplasty (PTCA) is associated with a higher concentration of non-high density lipoprotein (HDL) cholesterol at baseline, and whether this contributes to the inflammatory reaction and luminal renarrowing after PTCA.

DESIGN

An ex vivo and in vitro study of 46 patients who underwent PTCA and who had repeat angiograms after six months. Blood samples were collected immediately before PTCA, and at 24 hours, 48 hours, and 15 days after.

SETTING

Tertiary referral centre.

SUBJECTS

46 patients (30 male, 16 female; mean (SD) age, 62 (5) years) with stable or unstable angina who underwent elective PTCA.

MAIN OUTCOME MEASURES

Continuous variable luminal loss as defined by change in minimum lumen diameter during follow up, normalised for vessel size; lag phase of low density lipoprotein to in vitro oxidation; plasma fluorescent products of lipid peroxidation (FPLP); plasma vitamin C and E; interleukin (IL) 1beta secretion from unstimulated monocytes; plasma C reactive protein (CRP).

RESULTS

Restenosis occurred in 12 patients (26%). Oxidant stress after PTCA was greater (p < 0.0001 at 15 days) in the patients with restenosis and showed a significant correlation with the preprocedural concentration of non-HDL cholesterol (p < 0.001). Inflammatory reaction (as reflected by IL-1beta production and CRP) and late lumen loss were linearly correlated (p < 0.001) with lag phase and FPLP throughout the study, and inversely (p < 0.05) with vitamin C and E measured at two and 15 days after PTCA.

CONCLUSIONS

This study provides evidence for the critical role of cholesterol dependent oxidant stress in the pathophysiology of restenosis after PTCA. The findings raise the possibility that drugs capable of modulating oxidant status might provide a novel form of adjuvant treatment in patients with hypercholesterolaemia undergoing PTCA.

Overexpression of functionally coupled cyclooxygenase-2 and prostaglandin E synthase in symptomatic atherosclerotic plaques as a basis of prostaglandin E(2)-dependent plaque instability

BACKGROUND

Studies have implicated a role for prostaglandin (PG) E(2)-dependent matrix metalloproteinase (MMP) biosynthesis in the rupture of atherosclerotic plaque. Cyclooxygenase-2 (COX-2) and PGE synthase (PGES) are coregulated in nucleated cells by inflammatory stimuli. The aim of this study was to characterize the expression of COX-2 and PGES in carotid plaques and to correlate it with the extent of inflammatory infiltration and MMP activity and with clinical features of patients' presentation.

METHODS AND RESULTS

Plaques were obtained from 50 patients undergoing carotid endarterectomy and divided into 2 groups (symptomatic and asymptomatic) according to clinical evidence of recent transient ischemic attack or stroke. Plaques were analyzed for COX-2, PGES, MMP-2, and MMP-9 by immunocytochemistry and Western blot, whereas zymography was used to detect MMP activity. Immunocytochemistry was used to identify CD68+ macrophages, CD3+ T lymphocytes, and HLA-DR+ cells. The percentage of macrophage-rich areas was larger (P<0.0001) in symptomatic plaques. COX-2, PGES, and MMPs were detected in all specimens; enzyme concentration, however, was significantly higher in symptomatic plaques. COX-2, PGES, and MMPs were especially noted in shoulders of symptomatic plaques, colocalizing with HLA-DR+ macrophages. All symptomatic plaques contained activated forms of MMPs. Finally, inhibition of COX-2 by NS-398 was accompanied by decreased production of MMPs that was reversed by PGE(2).

CONCLUSIONS

This study demonstrates the colocalization of COX-2 and PGES in symptomatic lesions and provides evidence that synthesis of COX-2 and PGES by activated macrophages is associated with acute ischemic syndromes, possibly through metalloproteinase-induced plaque rupture.

Elevated circulating levels of monocyte chemoattractant protein-1 in patients with restenosis after coronary angioplasty

Inflammation plays a pathogenic role in the development of restenosis after percutaneous transluminal coronary angioplasty (PTCA). Monocyte chemoattractant protein-1 (MCP-1) is a potent chemoattractant of monocytes; however, its role in the pathophysiology of restenosis is still unclear. We set out to investigate the role of MCP-1 in restenosis after PTCA. In addition, we tested the hypothesis that MCP-1 exerts its effect, at least in part, by inducing O(2)(-) generation in circulating monocytes. Plasma levels of MCP-1 were measured before and 1, 5, 15, and 180 days after PTCA in 50 patients (30 males and 20 females, aged 62+/-5 years) who underwent PTCA and who had repeated angiograms at 6-month follow-up. Restenosis occurred in 14 (28%) patients. The MCP-1 level was no different at baseline between patients with or without restenosis. However, after the procedure, restenotic patients, compared with nonrestenotic patients, had statistically significant (P<0.0001) elevated levels of MCP-1. In contrast, plasma levels of other chemokines, such as RANTES and interleukin-8, did not differ between the 2 groups after PTCA. Higher MCP-1 throughout the study was correlated with restenosis. Moreover, increased MCP-1 was significantly correlated with increased monocyte activity, as reflected by enhanced O(2)(-) generation. Finally, multivariate regression analysis showed that the MCP-1 plasma level measured 15 days after PTCA was the only statistically significant independent predictor of restenosis (beta=0.688, P<0.0001). This study suggests that MCP-1 production and macrophage accumulation in the balloon-injured vessel may play a pivotal role in restenosis after PTCA. MCP-1 may induce luminal renarrowing, at least in part, by inducing O(2)(-) release in monocytes. Further understanding of the mechanism(s) by which MCP-1 is produced and acts after arterial injury may provide insight into therapies to limit the progression of atherosclerosis and restenosis after balloon angioplasty.

Relations of employment status to emotional distress among chronic pain patients: a path analysis

OBJECTIVE

This cross-sectional study evaluated the extent to which relations between employment status and emotional distress are mediated by pain-related and psychosocial measures among employed and unemployed persons with chronic pain.

DESIGN

A total of 40 unemployed and 43 employed persons reporting chronic pain were recruited from pain services at a tertiary-care hospital and community-based organizations. Volunteers completed self-report measures of pain severity, subjective financial stress, time structure, emotional distress, and background data.

RESULTS

A path analysis indicated that pain severity had direct associations with both emotional distress and employment status. In addition, employment status was only indirectly related to emotional distress; this relation was mediated by levels of reported financial strain and structured purposeful time use.

CONCLUSIONS

Findings suggest that pain severity and the quality of specific experiences related to being employed or unemployed as opposed to employment status per se correspond directly to levels of emotional distress reported by some persons with chronic pain.

Magnetic resonance angiography and colour-Doppler sonography in the evaluation of abdominal aortic aneurysms

This prospective study was aimed at comparing the diagnostic accuracy of magnetic resonance angiography (MRA) with colour-Doppler ultrasonography (colour-Doppler US) in the assessment of abdominal aortic aneurysms (AAA). Twenty patients with abdominal aortic aneurysms underwent MRA, colour-Doppler US, digital subtraction angiography (DSA) and CT. The MRA technique and colour-Doppler findings were compared with DSA as well as surgical and pathological findings, which were considered as the gold standard. In 6 patients who refused surgery, CT and DSA were considered as the gold standard. The MRA technique always correctly assessed the size and site of the aneurysms, the involvement of the renal and common iliac arteries, the course of the left renal vein, the thrombotic component and the calcifications. Colour-Doppler US always correctly assessed the size and site of the aneurysms, the thrombotic component and calcifications and the involvement of the iliac arteries. Our preliminary results suggest that MRA together with colour-Doppler US represents a valid alternative to invasive imaging in the assessment of AAA.

The impact of psychosocial features of employment status on emotional distress in chronic pain and healthy comparison samples

This study examined the extent to which measures of psychosocial features of employment status predict emotional distress in chronic pain (n = 83) and healthy comparison (n = 88) samples. Participants completed measures of emotional distress, pain severity, psychosocial features of employment status, and demographic data. After controlling for length of current unemployment, number of pain sites, and level of current pain severity, psychosocial measures (structured and purposeful time use, perceived financial security, skill use, social support form formal sources) were significant predictors of emotional distress in the chronic pain sample. Similar results were obtained for the healthy comparison sample. Structured and purposeful time use emerged as the most significant individual predictor of emotional distress for both samples. Findings are discussed in terms of their potential implications for treating chronic pain patients and the need to develop multidimensional measures that assess features of employment status within chronic pain samples.

The differential effects of employment status on chronic pain and healthy comparison groups

We evaluated the differential effects of employment status on chronic pain and healthy comparison groups. Forty unemployed and 43 employed individuals with chronic pain, as well as 43 unemployed and 45 employed healthy comparison participants completed a series of measures assessing background information physical and psychological adjustment, and psychosocial features of employment status. In general, participants experiencing both chronic pain and unemployment reported poorer adjustment than the other groups and more financial strain, less structured and purposeful activity, fewer opportunities for skill use and task variety, and decreased social support than the employed chronic pain and healthy comparison groups. Groups did not differ, however, in work ethic values. Scores on measures of pain severity and features of employment status accurately predicted the group membership of more than 70% of respondents from four groups. The study suggests that there is utility in understanding experiences of chronic pain patients on the basis of features of their current employment status and points to a need for multidimensional measures that evaluate psychosocial facets of employment and unemployment specifically for chronic pain samples.

Randomised trial of oral morphine for chronic non-cancer pain

BACKGROUND

The use of opioid analgesics for chronic non-cancer pain is controversial. Some surveys report good pain relief and improvement in performance while others suggest a poor outcome with a propensity to psychological dependence or addiction.

METHODS

We undertook a randomised double-blind crossover study to test the hypothesis that oral morphine relieves pain and improves the quality of life in patients with chronic regional pain of soft tissue or musculoskeletal origin who have not responded to codeine, anti-inflammatory agents, and antidepressants. Morphine was administered as a sustained-release preparation in doses up to 60 mg twice daily and compared with benztropine (active placebo) in doses up to 1 mg twice daily over three-week titration, six-week evaluation, and two-week washout phases. Pain intensity, pain relief, and drug liking were rated weekly and psychological features, functional status, and cognition were assessed at baseline and at the end of each evaluation phase.

FINDINGS

After dose titration in the 46 patients who completed the study, the mean daily doses of drugs were morphine 83.5 mg and benztropine 1.7 mg. On visual analogue scales, the morphine group showed a reduction in pain intensity relative to placebo in period I (p = 0.01) and this group also fared better in a crossover analysis of the sum of pain intensity differences from baseline (p = 0.02). No other significant differences were detected.

INTERPRETATION

In patients with treatment-resistant chronic regional pain of soft-tissue or musculoskeletal origin, nine weeks of oral morphine in doses up to 120 mg daily may confer analgesic benefit with a low risk of addiction but is unlikely to yield psychological or functional improvement.

[Auditory brain stem evoked potentials in the evaluation of chronic fatigue syndrome]

The Chronic Fatigue Syndrome (CFS) was formally defined to describe disabling fatigue of multifactorial ethology with depression and immunologic dysfunctions linked to some currently recognized infectious agents. In most cases neurophysiological tests reveal abnormalities. In this paper the Authors use low (11 pps) and high (51-71 pps) frequency ABR to evaluate the electrophysiological function of auditory brainstem responses. Eighteen patients with suspected CFS, between the ages of 17 and 63, were examined. Eleven subjects had clinically diagnosed "true" CFS (CDC criteria modified by Fukuda). The 11 pps frequency test did not reveal a high number of abnormalities in the patients in question. However, the high frequency stimulation test (with 51 and 71 pps) which was statistically significant (P = 0.009) revealed numerous aberrations in 7 patients; absence of the first wave in 1 case, in 5 numerous wave gap delays and in 1 patient absence of the first wave and numerous wave gap delays. The high frequency test did not show many abnormalities for the 4 remaining patients. For the 7 "non CFS" subjects, the clinical-audiological comparison showed no statistical significance (P = 0.920). The Authors hypothesize that the absence of the first wave in the CFS Subject may well indicate a cyto-neural junction disease in the organ of Corti. The combined analysis of clinical and audiological data showed that the described tests are more reliable when employed in dealing with patients with clinically assessed "true" CFS.

[Isoflurane in angiography with magnetic resonance]

The authors investigated if the use of vasodilating drugs could increase Magnetic Resonance angiography (MRA) capabilities in demonstrating intracranial vessels. Twenty patients (mean age: 10 years) were examined with MRA: a vasodilating drug (isoflurane) was administered to 10 of them and 10 matched-pair subjects were selected as controls and submitted to MRA without receiving any drug known to increase cerebral blood flow. MRA was performed with a 1.5-T superconductive magnet; FISP 3D sequences were used in all cases. A multiple choice card was used by a reader reporting the following diagnostic information for the different segments of the intracranial vessels: 1) hyperintense and homogeneous vessel with high signal-to-noise (S/N) ratio; 2) hyperintense and heterogeneous vessel with high S/N ratio; 3) hyperintense vessel with low S/N ratio; 4) poor vessels depiction. Small vessels (ophthalmic arteries, A3, M3, M4, anterior communicating arteries and P2 segments) were better demonstrated with isoflurane than with conventional MRA. The results were compared with the Mann-Withney test: isoflurane MRA allowed good vessel depiction in 127 cases, versus 83 of conventional MRA; the difference was statistically significant. To conclude, the use of vasodilating drugs represents a new research field in MRA of the intracranial vessels.

The role of magnetic resonance angiography in the diagnosis of subclavian steal

PURPOSE

To compare magnetic resonance angiography (MRA) with digital angiography for diagnosis of subclavian steal syndrome.

METHODS

A comparison study between MRA and digital contrast arteriography was carried out in 10 patients with suspected subclavian steal syndrome. Two of these patients were studied by MRA before and after percutaneous transluminal angioplasty (PTA). MRA was obtained on a 1.5 tesla superconductive magnet with linear head coil using a fast low angle shot (FLASH 2D) sequence in the axial plane as well as a fast imaging with steady state precession (FISP 3D) with velocity compensation gradient echo sequence in the coronal plane. The coronal images were used as source data for the construction of projection images with the use of a maximum-intensity pixel algorithm. The images were rotated from -45 degrees to 45 degrees in 15 degrees steps.

RESULTS

All 10 patients had evidence of proximal subclavian artery obstruction and flow reversal in the ipsilateral vertebral artery. On MRA, consistent visualization of the affected vertebral artery in the FLASH 2D sequences and nonvisualization in the FISP 3D sequences was interpreted as an indirect sign of subclavian steal. The subclavian artery obstruction could not be assessed due to field size limits of MRA.

CONCLUSION

MRA allows determination of flow reversal in the diagnosis of subclavian steal.

[Aneurysm of the abdominal aorta. Angiography with magnetic resonance versus color Doppler ultrasonography]

This prospective study was aimed at comparing the diagnostic accuracy of Magnetic Resonance Angiography (MRA) with that of color-Doppler ultrasonography (color-Doppler US) in the detection and assessment of abdominal aortic aneurysms. Twenty patients with abdominal aortic aneurysms underwent MRA, color-Doppler US, digital subtraction angiography (DSA) and Computed Tomography (CT) on three consecutive days. Fourteen patients underwent surgical repair of the aneurysm. MRA and color-Doppler findings were compared with DSA, surgical and pathologic findings, which were considered as the gold standard. In the 6 patients who refused surgery, CT and DSA were considered the gold standard. MRA always correctly assessed the size and site of the aneurysm, the involvement of the renal and common iliac arteries, the retroarotic course of the left renal vein, the thrombotic component and calcifications. Color-Doppler US always correctly assessed the size and site of the aneurysm, the thrombotic component and calcifications and the involvement of the iliac arteries. In one case color-Doppler US failed to demonstrate the involvement of the renal arteries and the retroaortic course of the left renal vein. Our preliminary results suggest MRA as the best non-invasive technique to study abdominal aortic aneurysms.

Somatothymia in chronic pain patients

Somatothymia is the use of somatic language to communicate affective distress. A total of 152 chronic pain patients completed a systems review checklist and the Minnesota Multiphasic Personality Inventory. Associated features of somatic symptoms and the meaningfulness of somatic symptoms as a communication, common physical areas of somatic focus, patterns of affective distress in high and low somatothymics, and the utility of select variables classifying high and low somatothymics were evaluated. The results indicate that a systems review checklist can be used as a quick, useful, and initial screen for somatothymia and that somatic symptoms can in fact communicate affective distress.

[Staging of pulmonary apex tumors. Computerized tomography versus magnetic resonance]

Apical lung cancers account for about 5% of pulmonary lesions and can be divided into two groups: Pancoast and non-Pancoast lesions. Recently, the use of MRI has been suggested in combination with CT to stage this kind of lung cancer. In this paper the authors' experience is reported relative to the current role of MRI and CT in the staging of apical lung cancers. Twelve male patients (mean age: 60.5 years) with apical lung cancers underwent conventional X-ray, CT and MR examinations of the chest. CT and MR images were studied by two independent radiologists with specific experience; surgery was the gold standard in three patients and MR and clinical symptoms in the patients not referred for surgery. In 15/108 cases (13.8%) CT and MR findings were in disagreement but in 93/108 cases (86.2%) they were in agreement. The highest disagreement rate was observed in the study of apical chest wall infiltration (33.3%), while in the study of anonymous vein involvement CT and MRI were always in agreement. The correct assessment of the regional extent of apical lung cancers is mandatory for treatment planning. In this kind of tumors MRI can be considered the method of choice thanks to its high contrast resolution and multiplanar imaging capabilities.

[The superior and inferior venae cavae: angiography by TOF 2D magnetic resonance versus spin-echo sequences]

This work was aimed at assessing the usefulness of magnetic resonance angiography (MRA) in the investigation and diagnosis of vena cava conditions. Forty-five subjects that is 20 volunteers and 25 patients, were examined with MRA using a 1.5 T superconductive system (SE and angiography pulse sequences). In the 25 patients, 8 cases of thrombosis were diagnosed, together with 4 cases of suspected tumor spread into either the superior or the inferior vena cava, 2 cases of inferior vena cava agenesis, 5 cases of retroaortic left renal vein and 5 cases of abdominal aortic aneurysm. MRA was performed with the 2D time-of-flight (TOF) technique (FA 18 degrees, TR 30-40 ms, TE 10 ms); the images were acquired on the coronal, sagittal and axial planes with and without presaturation pulse and rotated in the post-processing according to the maximum intensity projection. In all volunteers MRA identified jugular veins, subclavian veins, anonymous veins, superior vena cava, inferior vena cava and common iliac veins. The main limitation of MRA was its spatial resolution. MRA proved to be less accurate than SE sequences in the assessment of tumor spread. As for thrombotic conditions, MRA provided useful additional information and is therefore considered a complementary technique to SE MRI. As for venous anomalies (double inferior vena cava, vena cava agenesis and retroaortic left renal vein) and in the study of the relationships with abdominal aortic aneurysms, MRA proved to be the more accurate of the two techniques.

Magnetic resonance angiography of the left renal vein

The authors evaluated magnetic resonance angiography (MRA) as a possible diagnostic method to image the left renal vein. Twenty-five patients with abdominal aortic aneurysm underwent both plain and contrast-enhanced CT, as well as two-dimensional (2D) sequential time of flight (TOF) MRA. MRA images were evaluated on the basis of the results of CT, taken as the "gold standard" for vessel demonstration. MRA was performed with a 1.5 T superconductive magnet (Magnetom), fast imaging with steady-state free precession (FISP) 2D sequence (TR 40 ms, TE 10 ms, FA 18 degrees). Images were acquired in breath-hold on the coronal and sagittal plane and reconstructed according to maximum intensity projection (MIP) and targeted-MIP techniques. MRA images acquired on the sagittal plane correctly showed the retroaortic course on the left renal v. in six cases. On the coronal plane, targeted-MIP reconstructions for the course of the left renal v. correctly detected its outlet at the level of the inferior vena cava in five cases and of the left iliac v. in one case. MRA appears to be a promising noninvasive vascular imaging technique capable of correctly detecting the course and the outlet of the left renal v. We particularly noticed that the left renal v. can be imaged in a few seconds by using only one scout view with 2D sequential TOF technique on the sagittal plane at the level of the abdominal aorta.

[The torcular Herophili: the diagnostic pitfalls in TOF 3D magnetic resonance angiography]

The authors report on a diagnostic pitfall which is often observed in magnetic resonance angiography (MRA) of intracranial vessels (time-of-flight 3D)--i.e., the absence of one of the two transverse sinuses. Fifty patients underwent MRA of the intracranial vessels with the TOF 3D (FISP) and the TOF 2D (FISP) techniques. Five patients were affected with sinus stenosis. MRA was performed with a 1.5-T superconductive magnet and a circular head coil. All patients underwent Magnetic Resonance Angiography with FISP 2D sequences (FA 40 degrees, TR 40 ms, TE 12 ms) acquired on coronal plane as well as FISP 3D (FA 15 degrees, TR 30 ms, TE 7 ms) acquired on axial plane. In the patients in whom FISP 2D sequences correctly demonstrated the whole confluence of sinuses, FISP 3D sequences always depicted the upper sagittal sinus, while the right transverse sinus was seen in 84.4% (38/45) of cases and the left transverse sinus in 24.2% (11/45) of cases. In the patients with a stenosis in the confluence of sinuses, FISP 3D sequences demonstrated two false-positive cases with respect to FISP 2D. The statistical analysis (McNemar test) of the results demonstrated the difference between 2D and 3D sequences in the detection of the two transverse sinuses to be statistically significant: p < 0.01 for the right transverse sinus and p < 0.001 for the left transverse sinus. In the study of the intracranial vessels (TOF 3D technique) the absence of one of the two transverse sinuses is suggestive of a diagnostic pitfall; the combination of 3D and 2D sequences answers this diagnostic question.

Magnetic resonance angiography compared with basic magnetic resonance in intracranial vascular diseases

The diagnostic value of magnetic resonance angiography (MR-Angio) in the study of intracranial vascular diseases was compared with that of basic magnetic resonance (MR) in 35 patients presenting with a total of 45 pathologies (13 vascular malformations, 17 aneurysms, 3 vascular stenoses, all also examined by standard angiography, and 12 cases of dolichobasilar artery). A joint reading of the results was carried out by two radiologists who evaluated the basic MR and MR-Angio separately and thereafter filled in a fixed-choice answer form. In the author's opinion, MR-Angio may be considered a complementary technique to basic MR, offering a greater capacity for identification and characterization of these intracranial lesions. In vascular malformations and aneurysms, MR-Angio may be performed as a preliminary to digital subtraction angiography.

[Neoplasms of the glomus caroticum: magnetic resonance angiography versus magnetic resonance]

This work was aimed at investigating the diagnostic role of Magnetic Resonance angiography (MRA) versus spin-echo images in the study of carotid paragangliomas. Ten patients affected with carotid paragangliomas were studied; surgery was the gold standard. MR examinations were performed with a superconductive 1.5 T magnet and a linear head coil. T1-weighted (TR 500 ms, TE 15 ms, 256 x 256 matrix) and T2-weighted (TR 2000 ms, TE 15/90 ms, 256 x 256 matrix) spin-echo sequences were acquired. TOF 3D (flash: FA 25 degrees, TR 30 ms, TE 7 ms) MRA images were acquired; coronal and sagittal images were rotated according to the MIP. Spin-echo images demonstrated the typical "salt and pepper" pattern in all cases. In 6 cases (lesion diameter > 3 cm) the vascular structures of the paragangliomas and carotid dislocation were clearly demonstrated by MRA. MRA also depicted carotid dislocation in all cases. In conclusion, in the evaluation of carotid paragangliomas > 3 cm diameter, MRA yields complementary information on vascular structures and dislocation of carotid vessels to spin-echo MR sequences.

[Carotid bifurcation: angiography with magnetic resonance versus carotid angiography]

The reliability of Magnetic Resonance Angiography (MRA) was investigated in the study of stenosis and obstruction of carotid bifurcation; digital carotidography was the gold standard. Twenty-five consecutive patients with clinical suspicion of cerebrovascular insufficiency entered the study. MRA was performed with a 1.5 T superconductive magnet (Magnetom Siemens) and a linear head coil. The TOF 3D (FA 20 degrees, TR 30 ms, TE 7 ms) technique was applied. Images were acquired on the sagittal plane and rotated in postprocessing according to MIP on the z axis from 60 to 120 degrees (step 5). MRA exhibit 80.5% sensitivity, 96% specificity, 89.4% accuracy, 94.7% positive predictive value and 86.3% negative predictive value. When calculating the interrupted flow relative to hemodynamically significant stenoses (range 31%-occlusions), MRA sensitivity was 80.5%, specificity 100%, negative predictive value 86.3%, positive predictive value 94.7% and overall diagnostic accuracy 91.2%. MRA is to be considered a diagnostically reliable procedure in the study of carotid bifurcation and its diagnostic accuracy may even be increased in the future by the possible assessment of over- and underestimated cases.

[Whole body MR angiography. Physiologic presaturation++ of the inferior vena cava]

Whole-body MRA, performed with the time-of-flight (TOF) technique requires presaturation pulses adequately positioned and to eliminate the arterial and/or venous signal (FRODO technique: "Flow Respiratory artifact Obliteration with Directed Orthogonal pulses"). Additional presaturation pulses involve an increase in the radiofrequency dose absorbed by the patient, frequently over 0.4 watt x kg, which is the threshold absorption per kg. In the present paper, the possible saturation of caval system exploiting the modulation of apnea in whole-body MRA was investigated. Ten volunteers and 10 patients with different diseases were studied. All subjects underwent abdominal MRA with the TOF 2D (FA 18 degrees, TR 22 ms, TE 10 ms) technique. Images were acquired with three modulations of apnea: maximum inspiration, expiration, Müller maneuver. With respect to the anteroposterior diameter of inferior vena cava in inspiration, the inferior cava was reduced by 21.7% in expiration and by 35.7% in Müller maneuver. The lower caliber of vena cava allowed selective angiogram of the aorta. Expiration maneuvers are suggested as an alternative to caval flow saturation by the FRODO technique. As for expiration maneuvers, the volunteers and patients studied preferred to modulate the apnea in forcible expiration. Müller maneuver, through more effective (in 4 cases total caval collapse was obtained) is nonetheless more difficult.

[2D TOF angio-MR of the thoraco-abdominal aorta. Technique and clinical applications]

The diagnostic role of Magnetic Resonance Angiography (MRA) was investigated in the study of the thoracic and abdominal aorta. Thirty-two patients with different conditions were examined: the thoracic aorta was affected in 7 cases (3 aneurysms, 2 dissections, 2 tumors) and the abdominal aorta in 25 cases (21 aneurysms, 3 stenoses and 1 dissection). Moreover, 2 kinkings and 1 dextroposition of the thoracic aorta were observed as occasional findings, together with 15 abdominal aorta kinking cases. A 1.5-T superconductive magnet (Magnetom, Siemens) with circular polarization body coil and the 2D TOF (FL 18 degrees, TR 30 ms, TE 10 ms, ST 5 mm, 1-mm overlap) technique were used. The images acquired on the coronal and sagittal or parasagittal planes were rotated from -45 degrees to 45 degrees and from 60 degrees to 120 degrees during post-processing, according to MIP. Digital angiography was the gold standard in all cases, angiography and CT were the gold standards for aneurysms, and surgery for the lesions reaching the thoracic aorta. The 2D TOF technique allowed excellent visualization of both the thoracic and the abdominal aorta. In thoracic aorta conditions, MRA always identified aneurysms and assessed their relationship to epiaortic branchings. Moreover, MRA identified 2 cases of thoracic aorta dissection. In one case (1/2) MRA failed to depict aortic wall infiltration by tumor. In 21 abdominal aorta aneurysms, MRA always correctly demonstrated both the extent of the aneurysm and its relationships to renal and iliac arteries. Moreover, the thrombotic aneurysmal component was demonstrated, together with left renal vein course, which was retroaortic in 4 cases. Abnormal course, stenoses (2 cases) and dissection of the abdominal aorta were always identified by MRA.

[Abdominal aorta: role of angiography with magnetic resonance]

The diagnostic role of Magnetic Resonance angiography (MRA) was investigated in the study of the abdominal aorta. To obviate the problems relative to motion and respiratory artifacts, the TOF 2D (FISP 2D) technique was employed, together with a superconductive 1.5 T magnet. Fourteen volunteers were studied. The images acquired on the coronal and sagittal planes were processed according to MIP and target MIP, with a rotation on the z axis. The abdominal aorta was clearly demonstrated in 100% of cases, the celiac trunk in 42.8% of cases on coronal and in 100% on sagittal images. The superior mesenteric artery was depicted in 35.7% of cases on coronal and in 100% of subjects on sagittal acquisitions. The renal and iliac arteries were demonstrated in 100% of cases on coronal images only, while dorso-spinal and lumbar arteries were always clearly depicted on sagittal scans only. To evaluate the diagnostic reliability of MRA, 6 patients with abdominal aortic aneurysms were also studied and angiography and surgery were assumed as the gold standard. In all cases MRA yielded similar information to angiography and surgery as to aneurysm extent, vessel involvement and left renal vein course; moreover, MRA allowed the assessment of both the thrombotic and the calcific components of the aneurysm. Unenhanced MRA with the TOF 2D technique allows the detailed depiction of the aorta in about 20 minutes. Our preliminary results in the study of aneurysms are encouraging relative to the future diagnostic role of MRA in the abdominal aorta.

[Angiography with magnetic resonance++ of the renal arteries: bidimensional versus tridimensional "time of flight" technique]

Twenty volunteers were examined by means of 2D and 3D time of flight (TOF) Magnetic Resonance angiography (MRA) of the renal arteries. The possible diagnostic applications of MRA were also evaluated in 6 patients with renovascular diseases. MRA examinations of the renal arteries were performed with a 1.5 T superconductive magnet (Magnetom Siemens) and circular body coil. Ten volunteers were studied with 3D FISP sequences (FA 25 degrees, TR 40 ms, TE 7 ms, ST 1 mm, Ma 256 x 256, FOV 500); the images were acquired on the axial plane and were rotated, in MIP and target MIP, on the axial (z) and sagittal (x) axes. The other 10 volunteers were studied with 2D FLASH sequences (FA 18 degrees, TR 300 ms, TE 8 ms, ST 4 mm, overlap 1 mm, Ma 256 x 256, FOV 500); the images were acquired on the axial and coronal planes and were rotated, in MIP and target MIP, on the axial (z) and sagittal (x) axes. The ostium and proximal segments (1-15 mm) were always easily identified with 2D and 3D sequences, the distal segments (16-35 mm) were also clearly demonstrated in 11 cases with 3D (55%) and in 16 cases with 2D (85%) sequences. The bifurcations and branch vessels of the renal arteries were easily depicted with 3D TOF sequences in 7 cases only. Combined 3D and 2D TOF images permitted the thorough evaluation of the renal arteries. In renovascular diseases, 2D and 3D TOF images clearly demonstrated occlusions and stenoses of the proximal segment (1-15 mm). 2D TOF sequences only permitted the visualization of a case of fibromuscular dysplasia in the distal segment. Our results suggest that 2D and 3D TOF MRA exhibits good potentials as a noninvasive screening technique for the evaluation of renovascular diseases.

An identification of low back pain groups using biobehavioral variables

A multivariate predictive model of low back pain (LBP) was developed. Following a semi-structured interview, 73 participants were assigned to dysfunctional chronic low back pain (DCLBP), functional chronic low back pain (FCLBP), acute low back pain (ALBP), and healthy control (HC) groups. All participants underwent a comprehensive physical, psychophysiological, and psychological evaluation. Multivariate analyses indicated no psychophysiological, few physical, and many psychological differences among the groups. The DCLBP group was found to be most impaired in flexion (p<.001), and the HC group performed the most total work (ft-lb) in extension (p<.001). Psychologically, the DCLBP group displayed greater levels of emotional distress and characterological disturbances and were more functionally impaired (p<.001). Few differences between FCLBP and HC were found. A classification analysis using physical and psychological variables correctly classified 83.3% of DCLBP patients, and it was found that the ALBP group was heterogeneous with some patients having a dysfunctional profile and other patients having a functional profile. The psychological variables were more potent predictors of group membership than were the physical variables. These findings indicate that potential DCLBP and FCLBP patients can be identified shortly following an injury, suggesting important implications for assessment and treatment of low back pain in general, and more specifically, for reducing health care costs and human suffering.

[Magnetic resonance venogram of the intracranial circulation. Technique, anatomy, indications]

The authors standardized the MR-venography technique in 50 patients for the study of intracranial venous circulation and identified, for each vessel and district, the best acquisitions and rotations. The possible diagnostic applications of MR-angiography were also evaluated. The examinations were performed with a 1.5-T superconductive magnet (Magnetom, Siemens) and linear head coil. Fifty subjects were examined--40 healthy volunteers, 5 patients affected with multiple sclerosis (MS) and 5 patients with pathologic conditions of intracranial venous circulation. The 40 volunteers were studied with FISP 2D techniques; in 10 of them the images were acquired on the coronal plane, in 10 on the sagittal plane, in 10 on the axial plane, and in 10 on the axial plane after a 90 degrees saturation pulse to obtain saturation of the arterial signal. The FISP 3D sequence acquired on the axial plane and after i.v. gadolinium administration was used in the study of the 5 patients affected with MS. In the post-processing all the acquired images were rotated on the axial (z), sagittal (x), and coronal (y) axes, from 0 degrees to 180 degrees with a 15 degrees step. Data correlation showed that the veins of the postero-superior group were well visualized with 2D sequences on the sagittal plane and rotated, in the post-processing, on the z axis 0 degrees-180 degrees and on the coronal axis from -45 degrees to 45 degrees. The veins of the antero-inferior group were clearly demonstrated with 2D sequences acquired on the axial plane and after arterial saturation, rotated in the post-processing on the sagittal and coronal axes from -45 degrees to 45 degrees. Small veins--i.e., veins of the scalp, diploic and emissary veins, and inferior sagittal sinus--were well visualized with 2D sequences acquired on the coronal plane an rotated during post-processing on the z and x axes 0 degrees-180 degrees following i.v. injection of gadolinium. MR-venography is a new technique which can be useful to answer such specific diagnostic questions as the staging of brain neoplasm contiguous to intracranial venous vessels, the study of arteriovenous malformations and thrombosis on intracranial venous sinuses, as it has been demonstrated in 5 pathologic cases.

[Cerebrovascular pathology. Comparison of magnetic resonance and magnetic resonance angiography]

After making the visualization of the intracranial circulation possible without contrast media, the radiologist is now evaluating the diagnostic role of the different techniques of MRA. Attempts are also being made to characterize the main patterns of intracranial vascular diseases. The authors examined, with 3D TOF MRA, 40 patients presenting with 50 vascular lesions on MRI scans. Twenty of 40 patients were also studied with angiography. Seventeen aneurysms were detected, together with 3 stenoses of the cerebral arteries, 13 arteriovenous malformations, 12 dolichobasilar arteries, 3 postoperative and 2 post-embolization controls. MRI was performed with a superconductive magnet (1.5 T), a dedicated coil and gradient-echo 3D TOF FT sequences. The refocused sequence for flux, FISP 3DFT, required the following parameters: TR = 0.04 s, TE = 10 ms, flip angle = 15 degrees, 256 x 256 matrix, 1 acquisition. The 64-80 mm volume along the axial plane was divided so that an actual 1-mm thickness was excited. In post-processing, the maximum-intensity projection was employed on the axial plane 0 degrees-90 degrees (15 degrees interval). In the various conditions, the results obtained with MRA were correlated and compared with MRI findings. MRA provided useful additional information in 27.4% of cases in the study of aneurysms, arteriovenous malformations, vascular occlusion and dolichobasilar arteries, as well as in the follow-up of these lesions. MRA is currently suggested in the evaluation of cerebral circulation and is considered a complementary technique to MRI. MRA is also to be used preliminary to angiography.