Assessing the Equivalence of Brain-Derived Measures from Two 3D T1-Weighted Acquisitions: One Covering the Brain and One Covering the Brain and Spinal Cord

BACKGROUND AND PURPOSE

In MS, it is common to acquire brain and spinal cord MR imaging sequences separately to assess the extent of the disease. The goal of this study was to see how replacing the traditional brain T1-weighted images (brain-T1) with an acquisition that included both the brain and the cervical spinal cord (cns-T1) affected brain- and spinal cord-derived measures.

MATERIALS AND METHODS

Thirty-six healthy controls (HC) and 42 patients with MS were included. Of those, 18 HC and 35 patients with MS had baseline and follow-up at 1 year acquired on a 3T magnet. Two 3D T1-weighted images (brain-T1 and cns-T1) were acquired at each time point. Regional cortical thickness and volumes were determined with FastSurfer, and the percentage brain volume change per year was obtained with SIENA. The spinal cord area was estimated with the Spinal Cord Toolbox. Intraclass correlation coefficients (ICC) were calculated to check for consistency of measures obtained from brain-T1 and cns-T1.

RESULTS

Cortical thickness measures showed an ICC >0.75 in 94% of regions in healthy controls and 80% in patients with MS. Estimated regional volumes had an ICC >0.88, and the percentage brain volume change had an ICC >0.79 for both groups. The spinal cord area measures had an ICC of 0.68 in healthy controls and 0.92 in patients with MS.

CONCLUSIONS

Brain measurements obtained from 3D cns-T1 are highly equivalent to those obtained from a brain-T1, suggesting that it could be feasible to replace the brain-T1 with cns-T1.

SGLT1/2 expression in the heart of transplanted patients is associated with inflammatory induction of oxidative stress: potential protective effect of SGLT2 inhibitors

Introduction

Heart transplantation is a life-saving surgical procedure for patients with end-stage cardiac dysfunction, however, such procedures are usually at risk of rejection due to acute inflammatory activation. While such inflammatory induction leaves the newly transplanted heart at risk of functional and structural remodeling subsequent to oxidative damage, current anti-inflammatory treatment options expose the patient to an elevated risk for adverse reactions in addition to absence of cardio-protective effects. Therefore, novel therapies with anti-inflammatory and cardio-protective dual effects are needed. Recently, our group has reported that low-grade inflammation is associated with upregulation of SGLT1/2 in arteries of human with cardiovascular diseases. Yet, the role and function of SGLT2 in human cardiac tissue remains poorly understood.

Aim

This study focuses on the expression pattern of SGLT1/2 in cardiac biopsies of heart transplanted patients and aim to identifying their functional impact.

Methods

Routine endomyocardial Biopsies (23) were performed for the detection of acute rejection heart transplanted patients (less than 2 years) at our University Hospital. Gene expression levels were assessed using RT-qPCR, the in situ tissue localization of proteins by immunofluorescence staining, and the level of oxidative stress by dihydroethidium staining.

Results

Gene expression analysis revealed strong inflammatory reaction in 5 samples indicated by at least 20-fold higher levels of mRNA of IL1B, IL6, TNFA and CD68 compared to the other 18 samples and concomitant with high expression levels of SLC5A1, SLC5A2, AT1R, CYBA, NCF1, ICAM1, VCAM1, MMP2, MMP9 and TGFB1 in contrast to low levels of NOS3. In addition, increased levels of oxidative stress were observed in the same biopsies, which were diminished by the antioxidant N-acetylcysteine (NAC), NADPH oxidase inhibitor (VAS-2870), TNF-α receptor neutralizing antibody (infliximab), ACE inhibitor (perindoprilat), AT1R antagonist (losartan), dual SGLT1/2 inhibitor (sotagliflozin) and selective SGLT2 inhibitor (empagliflozin) with inhibitory effects reaching up to 80%. Immunofluorescence staining indicated signals for nitro-tyrosine, TNF-alpha, SGLT1 and 2 in several samples.

Conclusion

These findings indicate that both isoforms SGLT1 and SGLT2 are expressed in the transplanted human heart and suggest a pattern of expression associated with pro-inflammatory response. They further indicate a potential protective effect of SGLT2 inhibitors in transplanted hearts through mitigating oxidative stress and hence providing a possible novel therapy for heart transplantation recipients to preserve the heart function.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Boehringer Ingelheim Pharma GmbH & Co. KG

SWI as an Alternative to Contrast-Enhanced Imaging to Detect Acute MS Lesions

BACKGROUND AND PURPOSE

Acute inflammatory activity of MS lesions is traditionally assessed through contrast-enhanced T1-weighted MR images. The aim of our study was to determine whether a qualitative evaluation of non-contrast-enhanced SWI of new T2-hyperintense lesions might help distinguish acute and chronic lesions and whether it could be considered a possible alternative to gadolinium-based contrast agents for this purpose.

MATERIALS AND METHODS

Serial MR imaging studies from 55 patients with MS were reviewed to identify 169 new T2-hyperintense lesions. Two blinded neuroradiologists determined their signal pattern on SWI, considering 5 categories (hypointense rings, marked hypointensity, mild hypointensity, iso-/hyperintensity, indeterminate). Two different blinded neuroradiologists evaluated the presence or absence of enhancement in postcontrast T1-weighted images of the lesions. The Fisher exact test was used to determine whether each category of signal intensity on SWI was associated with gadolinium enhancement.

RESULTS

The presence of hypointense rings or marked hypointensity showed a strong association with the absence of gadolinium enhancement (P < .001), with a sensitivity of 93.0% and a specificity of 82.9%. The presence of mild hypointensity or isohyperintensity showed a strong association with the presence of gadolinium enhancement (P < .001), with a sensitivity of 68.3% and a specificity of 99.2%.

CONCLUSIONS

A qualitative analysis of the signal pattern on SWI of new T2-hyperintense MS lesions allows determining the likelihood that the lesions will enhance after administration of a gadolinium contrast agent, with high specificity albeit with a moderate sensitivity. While it cannot substitute for the use of contrast agent, it can be useful in some clinical settings in which the contrast agent cannot be administered.

Protective effects of dapagliflozin on vascular remodeling in the carotid artery following balloon injury – potential role of angiotensin and purinergic signaling

Introduction

Sodium-glucose co-transporter 2 (SGLT2) inhibitors have been shown to reduce the risk of cardiovascular events independently of glycemic control. The possibility that SGLT2 inhibitors improve endothelial regeneration and vascular restenosis is unknown.

Purpose

To examine whether dapagliflozin, a selective SGLT2 inhibitor, could prevent neointima thickening induced by balloon injury and, if so, to determine the underlying mechanisms. The effect of dapagliflozin was compared to that of losartan, an angiotensin type 1 receptor (AT1R) antagonist.

Methods

Saline, dapagliflozin (1.5 mg/kg/day), or losartan (30 mg/kg/day) were administered orally for 5 weeks to male Wistar rats. Balloon injury of the left carotid artery was performed 1 week after starting the treatment and sacrificed 4 weeks later. Vascular reactivity was assessed on left (injured) and right (healthy) carotid artery rings. The extent of neointima was assessed by histomorphometric analysis, changes of target factors by immunofluorescence, RT-qPCR and histochemistry.

Results

Dapagliflozin and losartan treatments reduced neointima thickening by 32% and 27%, respectively. Blunted contractile responses to phenylephrine and relaxations to acetylcholine and down-regulation of eNOS were observed in the injured artery. These effects were not modified by the dapagliflozin or the losartan treatments. RT-qPCR investigations indicated an increased in gene expression of inflammatory (IL-1beta, ITGAM, VCAM-1), oxidative (p47phox, p22phox) and fibrotic (TGF-beta1) markers and a decreased of eNOS in the injured carotid. However, these changes were not affected by the pharmacological treatments. By contrast, significant increased levels of AT1R angiotensin receptor and NTPDase1 (CD39) ectonucleotidase were observed in the restenotic carotid artery of the dapagliflozin group. Histochemical analysis evidenced important NTPDase1 activity in the neointima.

Conclusions

Dapagliflozin effectively reduced neointimal thickening. As the contribution of AT1R and P2Y2 ATP receptor in smooth muscle cell proliferation and neointima formation has been reported in the literature, the present data suggest that dapagliflozin prevents restenosis through interfering with angiotensin and/or extracellular nucleotides signaling. SGLT2 transporter represent potential new target for limiting vascular restenosis.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): This work was supported by AstraZeneca

Empagliflozin treatment does not affect the hypertensive response to Ang II administration to rats but decreases oxidative stress in the arterial wall, and endothelial and cardiac dysfunction

Background

Selective sodium-glucose cotransporter 2 (SGLT2) inhibitors have shown cardiovascular protection in type 2 diabetes patients with established cardiovascular disease independently of glycemic control. Angiotensin II (Ang II) and H2O2 have been shown to be strong inducers of the expression of SGLT2 and 1 in endothelial cells promoting oxidative stress and endothelial dysfunction.

Purpose

This study examined the cardiovascular protective effect of empagliflozin (empa) in a normoglycemic experimental model of hypertension in the rat.

Methods

Male Wistar rats received empa (30 mg/kg/day) provided in the diet for 5 weeks. After 1 week, rats underwent sham surgery (sham rats) or surgery with implantation of an osmotic mini-pump infusing Ang II (0.4 mg/kg/d) for 4 weeks. Systolic blood pressure (SBP) was assessed by sphygmomanometry, the cardiac function using echocardiography, the expression level of target proteins by immunofluorescence staining, and the level of oxidative stress using dihydroethidium staining.

Results

Angiotensin II administration increased systolic blood pressure from about 130 to 180 mmHg, which was not affected by the empa treatment. The 4-week Ang II treatment did not significantly affect the systolic cardiac function (cardiac output, left ventricle ejection fraction) but impaired the diastolic function as indicated by a reduced E' and IVRT values, and an increased E/E' value. The Ang II treatment increased significantly the heart and right ventricle weight whereas the left ventricle + septum weight was slightly but not significantly increased. No such functional and structural changes were observed in the Ang II + empa treatment group. An increased immunofluorescence eNOS signal in the endothelium, and a higher level of ROS throughout the aorta wall were observed in the Ang II-treated group, both of which were significantly reduced in the empa + Ang II-treated group. In the Ang II-treated group, the high level of oxidative stress in the aorta was significantly reduced by the AT1 receptor antagonist losartan, the NADPH oxidase inhibitor VAS-2871, the eNOS inhibitor NG-nitro-L-arginine and also to a greater extent by the selective SGLT2 inhibitor empa compared to the dual SGLT1/2 inhibitor sotagliflozin.

Conclusion(s)

The present findings indicate that although the empa treatment did not affect the hypertensive response of rats to Ang II, the SGLT2 inhibitor prevented the deleterious impact of Ang II on the diastolic cardiac function and remodeling, and the upregulation of eNOS expression and oxidative stress in the aorta wall. Thus, these findings highlight the protective potential of empa on the cardiovascular system in a normoglycemic hypertensive experimental model.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Boehringer Ingelheim Pharma GmbH & Co KG (Biberach an der Riss, Germany)

Value of 3T Susceptibility-Weighted Imaging in the Diagnosis of Multiple Sclerosis

BACKGROUND AND PURPOSE

Previous studies have suggested that the central vein sign and iron rims are specific features of MS lesions. Using 3T SWI, we aimed to compare the frequency of lesions with central veins and iron rims in patients with clinically isolated syndrome and MS-mimicking disorders and test their diagnostic value in predicting conversion from clinically isolated syndrome to MS.

MATERIALS AND METHODS

For each patient, we calculated the number of brain lesions with central veins and iron rims. We then identified a simple rule involving an absolute number of lesions with central veins and iron rims to predict conversion from clinically isolated syndrome to MS. Additionally, we tested the diagnostic performance of central veins and iron rims when combined with evidence of dissemination in space.

RESULTS

We included 112 patients with clinically isolated syndrome and 35 patients with MS-mimicking conditions. At follow-up, 94 patients with clinically isolated syndrome developed MS according to the 2017 McDonald criteria. Patients with clinically isolated syndrome had a median of 2 central veins (range, 0-19), while the non-MS group had a median of 1 central vein (range, 0-6). Fifty-six percent of patients who developed MS had ≥1 iron rim, and none of the patients without MS had iron rims. The sensitivity and specificity of finding ≥3 central veins and/or ≥1 iron rim were 70% and 86%, respectively. In combination with evidence of dissemination in space, the 2 imaging markers had higher specificity than dissemination in space and positive findings of oligoclonal bands currently used to support the diagnosis of MS.

CONCLUSIONS

A single 3T SWI scan offers valuable diagnostic information, which has the potential to prevent MS misdiagnosis.

Ratio of T1-Weighted to T2-Weighted Signal Intensity as a Measure of Tissue Integrity: Comparison with Magnetization Transfer Ratio in Patients with Multiple Sclerosis

The study aim was to compare the ratio of T1WI to T2WI signal intensity (T1/T2) with magnetization transfer ratio, a marker of myelin integrity, in patients with multiple sclerosis. A moderate correlation (r = 0.50, P = .034) was found between the magnetization transfer ratio and T1/T2 in normal-appearing gray matter, and a strong correlation for normal-appearing white matter (r = 0.63, P = .005) and lesions (r = 0.70, P = .001). Results suggest that besides myelin integrity, other factors may be playing a role in T1/T2 measures.

P2253Intake of the omega 3 PUFAs formulation EPA:DHA 6:1 by aged rats reduced shedding of microvesicles from spleen-derived cultured leukocytes and their ability to promote senescence in endothelial cells

Introduction

Ageing is associated with the appearance of endothelial senescence promoting endothelial dysfunction and, ultimately, cardiovascular events. Circulating microvesicles (MVs) of patients with acute coronary syndrome promoted premature endothelial senescence by stimulating the local angiotensin system. Omega 3 PUFAs have been shown to reduce the risk of cardiovascular disease in patients at high risk.

Purpose

This study investigated whether a 7-day intake of the omega 3 formulation EPA:DHA 6:1 by rats affects the level of MVs released by spleen-derived cultured leukocytes as well as their ability to promote premature senescence in target endothelial cells (ECs), and, if so, to clarify the underlying mechanism.

Methods

Middle-aged male Wistar rats (M, 48-week old) received 500 mg/kg/d of either EPA:DHA 6:1, EPA:DHA 1:1, or vehicle (CTL) for 7 days. Thereafter, spleen-derived leukocytes, a rich source of MVs, were prepared and cultured for 24 h. Cultured ECs were prepared from porcine coronary arteries. Senescence-associated β-galactosidase activity (SA-β-gal) was assessed by C12FDG, protein expression level by Western blot analysis, oxidative stress by dihydroethidium using confocal microscopy, and procoagulant MVs by prothrombinase assay. Spleen-derived leukocytes from untreated young (Y, 12-week) and old (O, 72-week) rats were also studied.

Results

Shedding of MVs by spleen-derived leukocytes significantly increased with increasing age. Incubation of ECs with leukocyte-derived MVs (10 nM Phtd Ser eq.) from M and O but not those from Y induced premature senescence after 48 h. The stimulatory effect of M-MVs was prevented by losartan and associated with oxidative stress. M-MVs induced an upregulation of senescence markers (p16, p21, p53), pro-atherothrombotic markers (VCAM-1, ICAM-1, tissue factor), the pro-inflammatory marker cyclooxygenase-2 (COX-2) but not COX-1, and of the angiotensin system (angiotensin-converting enzyme and type 1 angiotensin receptor), whereas endothelial NO synthase was down-regulated. A one-week intake of EPA:DHA 1:1 and 6:1 by M rats decreased the leukocyte-derived MVs shedding by about 14% and 24%, and EPA:DHA 6:1 reduced their ability to induce ECs senescence by 38%. The stimulatory effect of M-MVs on the expression of target proteins was also observed with those from the EPA:DHA 1:1 but not with those from the 6:1 group.

Conclusion

These findings indicate that ingestion of EPA:DHA 6:1 by middle-aged rats reduces not only the shedding of MVs by spleen-derived leukocytes but also their ability to induce pro-senescent, pro-thrombotic and pro-inflammatory responses in endothelial cells most likely by decreasing the local angiotensin system. They further suggest that EPA:DHA 6:1 may help to delay ageing-related endothelial dysfunction.

Acknowledgement/Funding

Unrestricted research grant from PIVOTAL Therapeutics Inc.

P6266Circulating microparticules of patients with coronary artery disease up-regulate the expression of sodium-glucose cotransporters 1 and 2 in coronary artery endothelial cells: role of angiotensin II

Introduction

Circulating microparticles (MPs) from patients with coronary artery diseases (CAD) have been shown to promote endothelial senescence and dysfunction involving the pro-oxidant local angiotensin system. Sodium-glucose cotransporters (SGLTs)2 inhibitors decreased the risk of cardiovascular disease in patients with type 2 diabetes and this effect appears to be independent of glycemic control. Moreover, high glucose and H2O2 have been shown to cause a redox-sensitive upregulation of SGLT1 and 2 in coronary artery endothelial cells (ECs).

Aim

Therefore, this study examined whether angiotensin II (Ang II, a potent NADPH oxidase-dependent inducer of oxidative stress) and CAD MPs stimulate SGLT1 and 2 expression in ECs, and assessed their role in the induction of endothelial dysfunction.

Methods

ECs were isolated from porcine coronary arteries. The protein expression level was assessed by Western blot analysis and immunocytochemical staining, oxidative stress using dihydroethidium staining, and senescence by senescence-associated beta-galactosidase activity (SA-beta-gal activity). Circulating CAD MPs were collected from blood samples of patients (61–79 year) with established cardiovascular disease.

Results

Control ECs expressed low levels of SGLT1 and SGLT2 proteins. Exposure of ECs to Ang II caused a time- and concentration-dependent increase in the protein level of SGLT1 and SGLT2 with a significant increase observed at concentrations as low as 10 nM. Exposure of ECs to CAD MPs (10 nM PhtdSer eq) from 3/5 patients increased the SGLT1 and SGLT2 protein level. An increased SGLT1 and SGLT2 immunofluorescence signal was also observed in response to Ang II and H2O2. Ang II increased the level of oxidative stress, SA-beta-gal activity, senescence markers (p53, p21 and p16), VCAM-1, MCP-1, tissue factor (TF) and the local angiotensin system (ACE, AT1R), and down-regulated that of eNOS. CAD MPs from 4/5 patients decreased eNOS level and from 5/5 patients increased VCAM-1 level. All the Ang II-induced effects were prevented by the dual SGLT1/2 inhibitor LX-4211 and the selective SGLT2 inhibitor, empagliflozin.

Conclusions

The present findings indicate that CAD MPs and Ang II upregulate the expression of SGLT1 and SGLT2 protein levels in ECs, and that they promote endothelial dysfunction. They further suggest that inhibition of SGLT1 and/or SGLT2 might be an attractive strategy to protect the arterial wall and, hence, the development of cardiovascular diseases.

Acknowledgement/Funding

Unrestricted research grant from Boehringer Ingelheim Pharma GmbH & Co. KG

P6278Ageing is associated with increased endothelial sodium-glucose cotransporter 1 expression at arterial sites at risk promoting enhanced anthocyanin accumulation and improved vascular oxidative stress

Introduction

Ageing is characterized by endothelial dysfunction and vascular oxidative stress affecting initially arterial sites at risk. Anthocyanin-rich products are potent stimulators of the endothelial formation of nitric oxide. Sodium-glucose co-transporter 1 (SGLT1) expression has been shown to be increased by oxidative stress and mediate anthocyanin uptake in endothelial cells.

Purpose

The study determined whether ageing is associated with an upregulation of SGLT1 in arterio-susceptible (aortic arch) and resistant (aorta) sites, and evaluated the vascular SGLT1-mediated anthocyanin uptake. In addition, the impact of a 2-week ingestion of an anthocyanin-rich blackcurrant concentrate (ARBC) by old rats on vascular anthocyanin uptake and oxidative stress, and systolic blood pressure (SBP) was assessed.

Methods

Male Wistar rats (22-month old) were either untreated or treated with ARBC (60 and 120 mg/kg/day) in the drinking water for 2 weeks. SGLT1 expression was assessed by immunofluorescence, anthocyanin accumulation by Neu A reagent using a purified extract (BCE) prepared from ARBC, oxidative stress by dihydroethidium using confocal microscopy, and SBP by tail-cuff sphingomanometry.

Results

SGLT1 immunofluorescence was observed predominantly in the endothelium and was higher in the aortic arch than the aorta in old rats whereas only low levels were observed in young rats (12-week old). Exposure of vascular sections to BCE resulted in anthocyanin uptake exclusively in the endothelium, which was higher in the aortic arch than the aorta, and more pronounced in old than young rats. Anthocyanin uptake induced by BCE in the aorta was markedly reduced by LX4211 (a SGLT1/2 inhibitor) both in old and young rats. A high level of oxidative stress was observed throughout the aortic wall of old compared to young rats, which was inhibited by LX4211. Ingestion of ARBC by old rats resulted in a dose-dependent accumulation of anthocyanins throughout the aorta wall and the aortic arch. The tissue accumulation of anthocyanins was associated with a reduced level of oxidative stress. Ageing was associated with increased SBP by about 8 mmHg, which was reduced by ARBC 60 and 120 mg/kg/day treatment by about 5 and 7 mmHg, respectively.

Conclusion

The present findings indicate that ageing is associated with an upregulation of SGLT1 predominantly in the endothelium and that this effect is more pronounced at the aortic arch than the aorta. The increased endothelial expression level of SGLT1 promoted a greater accumulation of anthocyanins sensitive to LX4211. In addition, a 2-week ingestion of ARBC by old rats resulted in the accumulation of anthocyanins throughout the arterial wall of the aortic arch and aorta, and resulted in a reduced level of oxidative stress and systolic blood pressure. Thus, SGLT1 may be an attractive target to restore vascular protection at arterial sites at risk by promoting endothelial and vascular uptake of anthocyanins.

Mechanisms underlying vasorelaxation induced in the porcine coronary arteries by Thymus linearis, Benth

ETHNOPHARMACOLOGICAL RELEVANCE

Thymus linearis, Benth indigenous to Pakistan has been traditionally used for the treatment of various diseases including hypertension.

AIM OF THE STUDY

Present study aims to investigate vasorelaxant effect of Thymus linearis and its underlying vasorelaxation mechanisms in porcine coronary artery rings.

MATERIALS AND METHODS

Aqueous-methanolic extract of aerial parts of Thymus linearis was prepared by maceration process and then bio-guided fractionation was carried out using different solvents. The effects of extract and subsequent fractions were assessed on coronary artery rings with intact and denuded endothelium. The mechanisms of vasorelaxant effect were investigated using different pharmacological tools. The in-vitro inhibitory effects of the test fractions were also assessed on purified phophodiestrases using radioenzymatic assay. Phytochemical studies were carried out using GCMS.

RESULTS

The aqueous-methanolic extract elicited similar relaxations in coronary artery rings with and without endothelium in dose dependent fashion and removal of endothelium did not alter this response. Further, n-butanolic fraction of Thymus liniaris (TLB) was found to be the most potent among other derived fractions. TLB did not alter the relaxation produced by endothelium dependent vasodilators in rings with intact endothelium. However, TLB significantly potentiated the relaxation elicited by cyclic AMP and cyclic GMP elevating drugs but not those to soluble guanylyl cyclase activators (YC-1 and BAY 41-2272) and K⁺ channel openers (levcromakalim and 1-EBIO). Pretreatment with TLB inhibited in a concentration-dependent manner contractions to KCl, CaCl₂ and U46619 in coronary artery rings without endothelium. Further, TLB was found to non-selectively inhibit the PDE activity in concentration manner.

CONCLUSION

n-Butanolic fraction of Thymus linearis possesses endothelium independent vasorelaxant effects in coronary artery by direct acting on the smooth muscles. These effects involve the elevation of the cyclic AMP and cyclic GMP possibly through the inhibition of various PDEs. GCMS analysis revel presence of thymole and carvacrol as major constituents. Furthermore, these investigations also support the folklore use of Thymus linearis in hypertension.

ALK7 expression in prolactinoma is associated with reduced prolactin and increased proliferation

Prolactinoma represents the most frequent hormone-secreting pituitary tumours. These tumours appear in a benign form, but some of them can reach an invasive and aggressive stage through an unknown mechanism. Discovering markers to identify prolactinoma proliferative and invading character is therefore crucial to develop new diagnostic/prognostic strategies. Interestingly, members of the TGFβ-Activin/BMP signalling pathways have emerged as important actors of pituitary development and adult function, but their role in prolactinomas remains to be precisely determined. Here, using a heterotopic allograft model derived from a rat prolactinoma, we report that the Activins orphan type I receptor ALK7 is ectopically expressed in prolactinomas-cells. Through immunohistological approaches, we further confirm that normal prolactin-producing cells lack ALK7-expression. Using a series of human tumour samples, we show that ALK7 expression in prolactinomas cells is evolutionary conserved between rat and human. More interestingly, our results highlight that tumours showing a robust expression of ALK7 present an increased proliferation as address by Ki67 expression and retrospective analysis of clinical data from 38 patients, presenting ALK7 as an appealing marker of prolactinoma aggressiveness. Beside this observation, our work pinpoints that the expression of prolactin is highly heterogeneous in prolactinoma cells. We further confirm the contribution of ALK7 in these observations and the existence of highly immunoreactive prolactin cells lacking ALK7 expression. Taken together, our observations suggest that Activin signalling mediated through ALK7 could therefore contribute to the hormonal heterogeneity and increased proliferation of prolactinomas.

Cervical Cord Atrophy and Long-Term Disease Progression in Patients with Primary-Progressive Multiple Sclerosis

BACKGROUND AND PURPOSE

Cervical cord atrophy has been associated with clinical disability in multiple sclerosis and is proposed as an outcome measure of neurodegeneration. The aim of this study was to quantify the development of cervical cord atrophy and to evaluate its association with disability progression in patients with primary-progressive multiple sclerosis.

MATERIALS AND METHODS

Thirty-one patients with primary-progressive multiple sclerosis underwent 1.5T brain and spinal cord MR imaging at baseline and 6-7 years later. The cervical spinal cord from C1 to C5 was segmented to evaluate the normalized overall cross-sectional area and the cross-sectional area of C2-C3, C3-C4, and C4-C5. The annualized rates of normalized cross-sectional area loss were also evaluated. To estimate clinical progression, we determined the Expanded Disability Status Scale score at baseline and at 2 and 14 years after baseline to compute the normalized area under the curve of the Expanded Disability Status Scale and the Expanded Disability Status Scale changes from baseline to the follow-up time points. Associations between the cord cross-sectional area and brain MR imaging and clinical measures were also investigated. Finally, the value of all these measures for predicting long-term disability was evaluated.

RESULTS

Some normalized cross-sectional area measurements showed moderate correlations with the normalized area under the curve of the Expanded Disability Status Scale, ranging from -0.439 to -0.359 (P < .05). Moreover, the annualized rate of the normalized mean cross-sectional area loss and the baseline Expanded Disability Status Scale were independent predictors of long-term disability progression.

CONCLUSIONS

These data indicate that development of cervical cord atrophy is associated with progression of disability and is predictive of this event in patients with primary-progressive MS.

Cumulative Dose of Macrocyclic Gadolinium-Based Contrast Agent Improves Detection of Enhancing Lesions in Patients with Multiple Sclerosis

BACKGROUND AND PURPOSE

Gadolinium-enhanced MR imaging is currently the reference standard for detecting active inflammatory lesions in patients with multiple sclerosis. The sensitivity of MR imaging for this purpose may vary according to the physicochemical characteristics of the contrast agent used and the acquisition strategy. The purpose of this study was to compare detection of gadolinium-enhancing lesions or active disease following a single or cumulative dose of a macrocyclic gadolinium-based contrast agent with different image acquisition delays in patients with clinically isolated syndrome or relapsing multiple sclerosis.

MATERIALS AND METHODS

All patients received a first dose (0.1 mmol/kg) of gadobutrol and, 20 minutes later, a second dose (0.1 mmol/kg), with a cumulative dose of 0.2 mmol/kg. Two contrast-enhanced T1-weighted sequences were performed at 5 and 15 minutes after the first contrast administration, and 2 additional T1-weighted sequences at 5 and 15 minutes after the second contrast administration with a 3T magnet.

RESULTS

One hundred fifteen patients were considered evaluable. A significantly larger number of lesions were detected in scans obtained at 5 and 15 minutes after the second contrast injection compared with scans obtained at 5 and 15 minutes after the first injection (P < .001). The number of patients with active lesions on MR imaging was significantly higher after the second dose administration (52.0%, first dose versus 59.2%, second dose; P < .001).

CONCLUSIONS

Cumulative dosing of a macrocyclic gadolinium-based contrast agent increases detection of enhancing lesions and patients with active lesions. These data could be considered in the design of MR imaging protocols aimed at detecting active multiple sclerosis lesions.

Measurement of Cortical Thickness and Volume of Subcortical Structures in Multiple Sclerosis: Agreement between 2D Spin-Echo and 3D MPRAGE T1-Weighted Images

BACKGROUND AND PURPOSE

Gray matter pathology is known to occur in multiple sclerosis and is related to disease outcomes. FreeSurfer and the FMRIB Integrated Registration and Segmentation Tool (FIRST) have been developed for measuring cortical and subcortical gray matter in 3D-gradient-echo T1-weighted images. Unfortunately, most historical MS cohorts do not have 3D-gradient-echo, but 2D-spin-echo images instead. We aimed to evaluate whether cortical thickness and the volume of subcortical structures measured with FreeSurfer and FIRST could be reliably measured in 2D-spin-echo images and to investigate the strength and direction of clinicoradiologic correlations.

MATERIALS AND METHODS

Thirty-eight patients with MS and 2D-spin-echo and 3D-gradient-echo T1-weighted images obtained at the same time were analyzed by using FreeSurfer and FIRST. The intraclass correlation coefficient between the estimates was obtained. Correlation coefficients were used to investigate clinicoradiologic associations.

RESULTS

Subcortical volumes obtained with both FreeSurfer and FIRST showed good agreement between 2D-spin-echo and 3D-gradient-echo images, with 68.8%-76.2% of the structures having either a substantial or almost perfect agreement. Nevertheless, with FIRST with 2D-spin-echo, 18% of patients had mis-segmentation. Cortical thickness had the lowest intraclass correlation coefficient values, with only 1 structure (1.4%) having substantial agreement. Disease duration and the Expanded Disability Status Scale showed a moderate correlation with most of the subcortical structures measured with 3D-gradient-echo images, but some correlations lost significance with 2D-spin-echo images, especially with FIRST.

CONCLUSIONS

Cortical thickness estimates with FreeSurfer on 2D-spin-echo images are inaccurate. Subcortical volume estimates obtained with FreeSurfer and FIRST on 2D-spin-echo images seem to be reliable, with acceptable clinicoradiologic correlations for FreeSurfer.

Cross-Cultural Adaptation of a Decision Support System for AT Selection

Older adults may benefit from decision support systems for the selection of assistive technologies. We present a case study cross-cultural adaptation in Canada of a system developed in the United Kingdom. We describe a conceptual framework for examining challenges with cultural and literacy issues and ways to address them.

Phospho-transfer networks and ATP homeostasis in response to an ineffective electron transport chain in Pseudomonas fluorescens

Although oxidative stress is known to impede the tricarboxylic acid (TCA) cycle and oxidative phosphorylation, the nutritionally-versatile microbe, Pseudomonas fluorescens has been shown to proliferate in the presence of hydrogen peroxide (H2O2) and nitrosative stress. In this study we demonstrate the phospho-transfer system that enables this organism to generate ATP was similar irrespective of the carbon source utilized. Despite the diminished activities of enzymes involved in the TCA cycle and in the electron transport chain (ETC), the ATP levels did not appear to be significantly affected in the stressed cells. Phospho-transfer networks mediated by acetate kinase (ACK), adenylate kinase (AK), and nucleoside diphosphate kinase (NDPK) are involved in maintaining ATP homeostasis in the oxidatively-challenged cells. This phospho-relay machinery orchestrated by substrate-level phosphorylation is aided by the up-regulation in the activities of such enzymes like phosphoenolpyruvate carboxylase (PEPC), pyruvate orthophosphate dikinase (PPDK), and phosphoenolpyruvate synthase (PEPS). The enhanced production of phosphoenolpyruvate (PEP) and pyruvate further fuel the synthesis of ATP. Taken together, this metabolic reconfiguration enables the organism to fulfill its ATP need in an O2-independent manner by utilizing an intricate phospho-wire module aimed at maximizing the energy potential of PEP with the participation of AMP.

Endothelium-independent vasorelaxant effect of a Berberis orthobotrys root extract via inhibition of phosphodiesterases in the porcine coronary artery

BACKGROUND

Berberis orthobotrys Bien ex Aitch. (Berberidaceae) is a plant indigenous of Pakistan that is locally used for the treatment of hypertension.

HYPOTHESIS

This study evaluated the vasoactive properties of a Berberis orthobotrys root extract and its fractions, and investigated the role of the endothelium and the underlying mechanism.

STUDY DESIGN

An aqueous methanolic extract of Berberis orthobotrys roots was prepared and submitted to a multi-step liquid-liquid fractionation with solvents of increasing polarity. Vascular reactivity of the different fractions was assessed using porcine coronary artery rings either with or without endothelium, and in the presence or absence of specific pharmacological tools. The ability of Berberis orthobotrys extracts to affect phosphodiesterase (PDE) activity was evaluated using a radioenzymatic method and purified phosphodiesterases.

RESULTS

The aqueous methanol extract induced similar relaxations in coronary artery rings with and without endothelium, and, amongst the three derived preparations, the butanol fraction (BFBO) was slightly but significantly more effective than the ethyl acetate fraction and the aqueous residue in rings without endothelium. Analysis of the butanol fraction (BFBO) by LC-ELSD-MS indicated the presence of four major isoquinoline alkaloids including berberine. BFBO significantly potentiated the relaxations induced by cyclic GMP- and cyclic AMP-dependent relaxing agonists, and inhibited contractions to KCl, CaCl2, and U46619 in endothelium denuded rings. In contrast, BFBO did not affect relaxations to endothelium-dependent vasodilators. BFBO concentration-dependently inhibited the cyclic GMP-hydrolyzing activity of basal PDE1, calmodulin-activated PDE1 and PDE5, and of cyclic AMP-hydrolyzing activity of PDE3 and PDE4 with IC50 values ranging from 40 to 130µg/ml.

CONCLUSION

The butanol fraction of the aqueous methanol extract of Berberis orthobotrys roots induced pronounced endothelium-independent relaxations and inhibited contractile responses by acting directly at the vascular smooth muscle in the coronary artery. Moreover, BFBO potentiated relaxations induced by both cyclic GMP- and cyclic AMP-dependent vasodilators most likely due to its ability to inhibit several vascular PDEs, and in particular PDE4 and PDE5.

Improved Automatic Detection of New T2 Lesions in Multiple Sclerosis Using Deformation Fields

BACKGROUND AND PURPOSE

Detection of disease activity, defined as new/enlarging T2 lesions on brain MR imaging, has been proposed as a biomarker in MS. However, detection of new/enlarging T2 lesions can be hindered by several factors that can be overcome with image subtraction. The purpose of this study was to improve automated detection of new T2 lesions and reduce user interaction to eliminate inter- and intraobserver variability.

MATERIALS AND METHODS

Multiparametric brain MR imaging was performed at 2 time points in 36 patients with new T2 lesions. Images were registered by using an affine transformation and the Demons algorithm to obtain a deformation field. After affine registration, images were subtracted and a threshold was applied to obtain a lesion mask, which was then refined by using the deformation field, intensity, and local information. This pipeline was compared with only applying a threshold, and with a state-of-the-art approach relying only on image intensities. To assess improvements, we compared the results of the different pipelines with the expert visual detection.

RESULTS

The multichannel pipeline based on the deformation field obtained a detection Dice similarity coefficient close to 0.70, with a false-positive detection of 17.8% and a true-positive detection of 70.9%. A statistically significant correlation (r = 0.81, P value = 2.2688e-09) was found between visual detection and automated detection by using our approach.

CONCLUSIONS

The deformation field-based approach proposed in this study for detecting new/enlarging T2 lesions resulted in significantly fewer false-positives while maintaining most true-positives and showed a good correlation with visual detection annotations. This approach could reduce user interaction and inter- and intraobserver variability.

[Review of reimbursement for instrumental techniques used for assisted coughing and thoracic expansion. A French National Health Authority assessment (HAS)]

INTRODUCTION

In France, children with neuromuscular diseases and patients with traumatic spinal cord injuries receive reimbursement for home use of intermittent positive-pressure breathing and mechanical in-exsufflators devices. The aim of the study was to update the indications for reimbursement for these both devices.

METHODS

A literature review was conducted with several bibliographic databases using the main keywords: intermittent positive-pressure breathing, mechanical insufflation, mechanically-assisted cough, airway clearance. Nine health professionals were interviewed during two meetings. One health professional was interviewed via a questionnaire. An estimation of the population treated with in-exsufflators or intermittent positive-pressure breathing was undertaken from consumer data available for all beneficiaries of the health insurance system.

STATE OF THE ART

The review identified 111 references which included 14 clinical practice guidelines, two systematic reviews and one randomized controlled trial. Some clinical data were available. Clinical practice guidelines were in favor of using intermittent positive-pressure breathing and in-exsufflators in patients with neuromuscular disease and spinal cord injuries. The healthcare professionals emphasized the need to reimburse the patient for home use of intermittent positive-pressure breathing and in-exsufflators. The patient population treated in the identified clinical situations was estimated at 3100 per year.

CONCLUSIONS

Despite the low level of evidence and after interviewing healthcare professionals, the Haute Autorité de santé (HAS) recommended reimbursement of the costs of in-exsufflators (assisted coughing) and intermittent positive-pressure breathing (thoracic expansion) devices in adults and children with neurological and neuromuscular disease, including spinal cord injury.

[Atypical ganglioglioma with BRAF V600E mutation: a case report and review of the literature]

INTRODUCTION

Gangliogliomas are rare tumours that affect young patients, appear predominantly in the temporal lobe and usually begin with epileptic seizures. Histologically they have a grade I of malignancy, with an anaplastic form that is catalogued as grade III in the 2007 WHO classification. Yet, there are tumours that do not meet the criteria of either grade and which offer clear prognostic differences with respect to those of grade I. These tumours would be atypical gangliogliomas (grade II), which are not considered in this classification. From the molecular point of view, the best known alteration in gangliogliomas is the BRAF V600E mutation, which worsens the prognosis of the lesion. The possible use of treatments targeted towards this mutated protein is especially relevant in this disorder.

CASE REPORT

A 21-year-old male, who had undergone surgery due to a ganglioglioma on two occasions. The neuro-pathological examination revealed histological features consistent with an intermediate grade of malignancy (grade II), with positive BRAF mutation.

CONCLUSIONS

The case presented here, together with those previously reported in the literature, reopens the debate on the definition of gangliogliomas in the 2007 WHO classification, and lends support to the fact that the next classification should again include atypical gangliogliomas (grade II), together with possible genetic mutations and molecular disorders.

Juxtacortical Lesions and Cortical Thinning in Multiple Sclerosis

BACKGROUND AND PURPOSE

The role of juxtacortical lesions in brain volume loss in multiple sclerosis has not been fully clarified. The aim of this study was to explore the role of juxtacortical lesions on cortical atrophy and to investigate whether the presence of juxtacortical lesions is related to local cortical thinning in the early stages of MS.

MATERIALS AND METHODS

A total of 131 patients with clinically isolated syndrome or with relapsing-remitting MS were scanned on a 3T system. Patients with clinically isolated syndrome were classified into 3 groups based on the presence and topography of brain lesions: no lesions (n = 24), only non-juxtacortical lesions (n = 33), and juxtacortical lesions and non-juxtacortical lesions (n = 34). Patients with relapsing-remitting MS were classified into 2 groups: only non-juxtacortical lesions (n = 10) and with non-juxtacortical lesions and juxtacortical lesions (n = 30). A juxtacortical lesion probability map was generated, and cortical thickness was measured by using FreeSurfer.

RESULTS

Juxtacortical lesion volume in relapsing-remitting MS was double that of patients with clinically isolated syndrome. The insula showed the highest density of juxtacortical lesions, followed by the temporal, parietal, frontal, and occipital lobes. Patients with relapsing-remitting MS with juxtacortical lesions showed significantly thinner cortices overall and in the parietal and temporal lobes compared with those with clinically isolated syndrome with normal brain MR imaging. The volume of subcortical structures (thalamus, pallidum, putamen, and accumbens) was significantly decreased in relapsing-remitting MS with juxtacortical lesions compared with clinically isolated syndrome with normal brain MR imaging. The spatial distribution of juxtacortical lesions was not found to overlap with areas of cortical thinning.

CONCLUSIONS

Cortical thinning and subcortical gray matter volume loss in patients with a clinically isolated syndrome or relapsing-remitting MS was related to the presence of juxtacortical lesions, though the cortical areas with the most marked thinning did not correspond to those with the largest number of juxtacortical lesions.

Pixel-by-Pixel Comparison of Volume Transfer Constant and Estimates of Cerebral Blood Volume from Dynamic Contrast-Enhanced and Dynamic Susceptibility Contrast-Enhanced MR Imaging in High-Grade Gliomas

BACKGROUND AND PURPOSE

Estimates of blood volume and volume transfer constant are parameters commonly used to characterize hemodynamic properties of brain lesions. The purposes of this study were to compare values of volume transfer constant and estimates of blood volume in high-grade gliomas on a pixel-by-pixel basis to comprehend whether they provide different information and to compare estimates of blood volume obtained by dynamic contrast-enhanced MR imaging and dynamic susceptibility contrast-enhanced MR imaging.

MATERIALS AND METHODS

Thirty-two patients with biopsy-proved grade IV gliomas underwent dynamic contrast-enhanced MR imaging and dynamic susceptibility contrast-enhanced MR imaging, and parametric maps of volume transfer constant, plasma volume, and CBV maps were calculated. The Spearman rank correlation coefficients among matching values of CBV, volume transfer constant, and plasma volume were calculated on a pixel-by-pixel basis. Comparison of median values of normalized CBV and plasma volume was performed.

RESULTS

Weak-but-significant correlation (P < .001) was noted for all comparisons. Spearman rank correlation coefficients were as follows: volume transfer constant versus CBV, ρ = 0.113; volume transfer constant versus plasma volume, ρ = 0.256; CBV versus plasma volume, ρ = 0.382. We found a statistically significant difference (P < .001) for the estimates of blood volume obtained by using dynamic contrast-enhanced MR imaging (mean normalized plasma volume, 13.89 ± 11.25) and dynamic susceptibility contrast-enhanced MR imaging (mean normalized CBV, 4.37 ± 4.04).

CONCLUSIONS

The finding of a very weak correlation between estimates of microvascular density and volume transfer constant suggests that they provide different information. Estimates of blood volume obtained by using dynamic contrast-enhanced MR imaging are significantly higher than those obtained by dynamic susceptibility contrast-enhanced MR imaging in human gliomas, most likely due to the effect of contrast leakage.

Brain metabolism and Alzheimer's disease: the prospect of a metabolite-based therapy

The brain is one of the most energy-demanding organs in the body. It has evolved intricate metabolic networks to fulfill this need and utilizes a variety of substrates to generate ATP, the universal energy currency. Any disruption in the supply of energy results in various abnormalities including Alzheimer's disease (AD), a condition with markedly diminished cognitive ability. Astrocytes are an important participant in maintaining the cerebral ATP budget. However, under oxidative stress induced by numerous factors including aluminum toxicity, the ability of astroctyes to generate ATP is impaired due to dysfunctional mitochondria. This leads to globular, glycolytic, lipogenic and ATP-deficient astrocytes, cerebral characteristics common in AD patients. The reversal of these perturbations by such natural metabolites as pyruvate, α-ketoglutarate, acetoacetate and L-carnitine provides valuable therapeutic cues against AD.

Significant clinical worsening after natalizumab withdrawal: Predictive factors

We aimed to single out multiple sclerosis (MS) cases with poor outcome after natalizumab withdrawal and to identify predictive variables. We ascertained 47 withdrawals, and compared their pre- and post-natalizumab periods. We objectively defined significant clinical worsening after natalizumab withdrawal as a 2-step increase in Expanded Disability Status Scale (EDSS). We performed regression models. As a group, post-natalizumab annualized relapse rate (ARR) was lower in the post-natalizumab period, and there were no differences in the mean number of gadolinium (Gd)-enhancing lesions between pre- and post-natalizumab magnetic resonance imaging (MRI). Corticosteroid treatment did not change the outcomes. Eight patients (19%) presented significant clinical worsening after natalizumab withdrawal, which was predicted by a higher baseline EDSS and a 1-step EDSS increase while on natalizumab.

Brain atrophy in natalizumab-treated patients: A 3-year follow-up

Background:

A pseudoatrophy effect has been held responsible for the lack of net impact of natalizumab on brain volume outcomes in 2-year trials, but no data are available beyond 24 months.

Objective:

We aimed to investigate brain volume dynamics in natalizumab-treated patients in up to 3 years after therapy initiation with clinical correlations.

Methods:

Patients on natalizumab for at least 3 years were clinically assessed 3-monthly. Magnetic resonance imaging scans were performed at baseline and yearly. Brain volume changes were obtained with SIENA. Multivariate models were used to investigate the association between baseline inflammation and changes in brain volume and disability.

Results:

Sixty-two patients with multiple sclerosis were analysed. Mean age and disease duration were 34.7 (SD: 8.3) and 10.4 (SD: 6.6) years. Presence of gadolinium enhancement at baseline was not associated with Expanded Disability Status Scale changes ( p=0.468), but was associated with larger brain volume decreases ( p=0.005) in the first ( p=0.024) and second year ( p=0.019) but not in the third year ( p=0.863). Brain volume changes at 12 and 36 months were marginally associated with disability status at month 12 ( p=0.094) and 36 ( p=0.084), respectively.

Conclusions:

Baseline inflammation affects brain volume measures up to 24 months after natalizumab initiation. A marginal association of brain volume changes with disability is present.

Zinc toxicity and ATP production in Pseudomonas fluorescens

AIMS

To identify the molecular networks in Pseudomonas fluorescens that convey resistance to toxic concentrations of Zn, a common pollutant and hazard to biological systems.

METHODS AND RESULTS

Pseudomonas fluorescens strain ATCC 13525 was cultured in growth medium with millimolar concentrations of Zn. Enzymatic activities and metabolite levels were monitored with the aid of in-gel activity assays and high-performance liquid chromatography, respectively. As oxidative phosphorylation was rendered ineffective, the assimilation of citric acid mediated sequentially by citrate lyase (CL), phosphoenolpyruvate carboxylase (PEPC) and pyruvate phosphate dikinase (PPDK) appeared to play a key role in ATP synthesis via substrate-level phosphorylation (SLP). Enzymes generating the antioxidant, reduced nicotinamide adenine dinucleotide phosphate (NADPH) were enhanced, while metabolic modules mediating the formation of the pro-oxidant, reduced nicotinamide adenine dinucleotide (NADH) were downregulated.

CONCLUSIONS

Pseudomonas fluorescens reengineers its metabolic networks to generate ATP via SLP, a stratagem that allows the microbe to compensate for an ineffective electron transport chain provoked by excess Zn.

SIGNIFICANCE AND IMPACT OF THE STUDY

The molecular insights described here are critical in devising strategies to bioremediate Zn-polluted environments.