Association between procedural time and outcome in unsuccessful mechanical thrombectomy for acute ischemic stroke: analysis from the Italian Registry of Endovascular Treatment in Acute Stroke.

BACKGROUND: We aim to assess the association between procedural time and outcomes in patients in unsuccessful mechanical thrombectomy (MT) for anterior circulation acute stroke. METHODS: We conducted a cohort study on prospectively collected data from patients with M1 and/or M2 segment of middle cerebral artery occlusion with a thrombolysis in cerebral infarction 0-1 at the end of procedure. Primary outcome was 90-day poor outcome. Secondary outcomes were early neurological deterioration (END), symptomatic intracranial hemorrhage (sICH) according to ECASS II and sICH according to SITS-MOST. RESULTS: Among 852 patients, after comparing characteristics of favourable and poor outcome groups, logistic regression analysis showed age (OR: 1.04; 95%CI: 1.02-1.05; p < 0.001), previous TIA/stroke (OR: 0.23; 95%CI: 0.12-0.74; p = 0.009), M1 occlusion (OR: 1.69; 95%CI: 1.13-2.50; p = 0.01), baseline NIHSS (OR: 1.01; 95%CI: 1.06-1.13; p < 0.001) and procedural time (OR:1.00; 95% CI: 1.00-1.01; p = 0.003) as independent predictors poor outcome at 90 days. Concerning secondary outcomes, logistic regression analysis showed NIHSS (OR:0.96; 95%CI: 0.93-0.99; p = 0.008), general anaesthesia (OR:2.59; 95%CI: 1.52-4.40; p < 0.001), procedural time (OR: 1.00; 95% CI: 1.00-1.01; p = 0.002) and intraprocedural complications (OR: 1.89; 95%CI: 1.02-3.52; p = 0.04) as independent predictors of END. Bridging therapy (OR:2.93; 95%CI: 1.21-7.09; p = 0.017) was associated with sICH per SITS-MOST criteria whereas M1 occlusion (OR: 0.35; 95%CI: 0.18-0.69; p = 0.002), bridging therapy (OR: 2.02; 95%CI: 1.07-3.82; p = 0.03) and intraprocedural complications (OR: 5.55; 95%CI: 2.72-11.31; p < 0.001) were independently associated with sICH per ECASS II criteria. No significant association was found between the number of MT attempts and analyzed outcomes. CONCLUSIONS: Regardless of the number of MT attempts and intraprocedural complications, procedural time was associated with poor outcome and END. We suggest a deeper consideration of procedural time when treating anterior circulation occlusions refractory to MT.

Thrombectomy in ischemic stroke patients with tandem occlusion in the posterior versus anterior circulation.

BACKGROUND: Mechanical thrombectomy (MT) was found to be beneficial in acute ischemic stroke patients with anterior tandem occlusion (a-TO). Instead, little is known about the effectiveness of MT in stroke patients with posterior tandem occlusion (p-TO). We aimed to compare MT within 24 h from last known well time in ischemic stroke patients with p-TO versus a-TO. METHODS: We conducted a cohort study on prospectively collected data of patients registered in the Italian Registry of Endovascular Treatment in Acute Stroke (IRETAS) who were treated with MT within 24 h from last known well time for acute ischemic stroke with p-TO (n = 275) or a-TO (n = 1853). RESULTS: After adjustment for unbalanced pre-procedure variables (year 2015-2021, age, sex, NIHSS score, ASPECTS, and time strata for puncture groin) and pre-stroke mRS score as pre-defined predictor, p-TO was significantly associated with lower probability of mRS score 0-2 (OR 0.415, 95% CI 0.268-0.644) and with higher risk of death (OR 2.813, 95% CI 2.080-3.805) at 3 months. After adjustment for unbalanced procedural and post-procedure variables (IVT, general anesthesia, TICI 3, and 24-h HT) and pre-stroke mRS score as pre-defined predictor, association between p-TO and lower probability of mRS score 0-2 (OR 0.444, 95% CI 0.304-0.649) and association between p-TO and with higher risk of death (OR 2.971, 95% CI 1.993-4.429) remained significant. CONCLUSIONS: MT within 24 h from last known well time in ischemic stroke patients with p-TO versus a-TO was associated with worse outcomes at 3 months.

Single-stage endovascular treatment in aneurysmal subarachnoid haemorrhage with multiple intracranial aneurysms: Systematic review of the literature and multicentric retrospective experience.

OBJECTIVES: The presence of multiple intracranial aneurysms in patients with acute subarachnoid haemorrhage is a condition with no evidence of optimal treatment strategy, especially in case of uncertain haemorrhage patterns on cumputed tomography. The aim of this study was to analyse the safety and efficacy profile of single-stage endovascular treatment of multiple intracranial aneurysms with aneurysmal subarachnoid haemorrhage in the literature and in a retrospective case series. MATERIALS AND METHODS: A systematic review of the present literature was conducted to identify studies related to single-stage endovascular treatment for ≥2 aneurysms; in addition, a retrospective multicentric review was performed. Data on clinical presentation, aneurysm size and location, occlusion rates, intracranial complications and clinical outcome were recorded. RESULTS: Thirteen articles were identified (all little case series) reporting 189 patients harbouring 389 aneurysms. And 85.6% presented with a Hunt-Hess scale 1-3, and 14.4% 4-5. Intracranial complications rate was 11.5%. Baseline and follow-up (20.5 months) occlusion rates were adequate (Raymond-Roy occlusion scale I-II) in 93% and 96.2%, respectively. 81% of patients had favourable clinical outcomes (modified Rankin Scale (mRS) ≤2; Glasgow outcome scale (GOS) 5-4) and 19% poor (mRS 3-6; GOS 3-1). The retrospective database identified 53 patients with 115 aneurysms. Clinical presentation was Hunt-Hess (HH) 1-3/WNFS 1-2 75% and HH 4-5/WNFS 3-5 25%. Intracranial complication rate was 24.5%. Occlusion rate RROC I-II was 78.7% at baseline and 15 months and 90.2% at follow up. Clinical outcome at 3 months was mRS ≤2 68.6% and mRS 3-6 31.4%. CONCLUSIONS: Single-staged endovascular treatment can be feasible, although a higher risk of intraprocedural complications, with clinical presentation being the major factor to influence the outcome.

IV thrombolysis plus thrombectomy versus IV thrombolysis alone for minor stroke with anterior circulation large vessel occlusion from the IRETAS and Italian SITS-ISTR cohorts.

INTRODUCTION: The aim of this study was to compare the outcomes of patients treated with intravenous thrombolysis (IVT) <4.5 h after symptom onset plus mechanical thrombectomy (MT) <6 h with those treated with IVT alone <4.5 h for minor stroke (NIHSS ≤5) with large vessel occlusion (LVO) in the anterior circulation. PATIENTS AND METHODS: Patients enrolled in the Italian Registry of Endovascular Treatment in Acute Stroke (IRETAS) and in the Italian centers included in the SITS-ISTR were analyzed. RESULTS: Among the patients with complete data on 24-h ICH type, 236 received IVT plus MT and 382 received IVT alone. IVT plus MT was significantly associated with unfavorable shift on 24-h ICH types (from no ICH to PH-2) (OR, 2.130; 95% CI, 1.173-3.868; p=0.013) and higher rate of PH (OR, 4.363; 95% CI, 1.579-12.055; p=0.005), sICH per ECASS II definition (OR, 5.527; 95% CI, 1.378-22.167; p=0.016), and sICH per NINDS definition (OR, 3.805; 95% CI, 1.310-11.046; p=0.014). Among the patients with complete data on 3-month mRS score, 226 received IVT plus MT and 262 received IVT alone. No significant difference was reported between IVT plus MT and IVT alone on mRS score 0-1 (72.1% versus 69.1%), mRS score 0-2 (79.6% versus 79%), and death (6.2% versus 6.1%). CONCLUSIONS: Compared with IVT alone, IVT plus MT was associated with unfavorable shift on 24-h ICH types and higher rate of 24-h PH and sICH in patients with minor stroke and LVO in the anterior circulation. However, no difference was reported between the groups on 3-month functional outcome measures.

Incidence and outcome of perforations during medium vessel occlusion compared with large vessel occlusion thrombectomy.

BACKGROUND: Vessel perforation during thrombectomy is a severe complication and is hypothesized to be more frequent during medium vessel occlusion (MeVO) thrombectomy. The aim of this study was to compare the incidence and outcome of patients with perforation during MeVO and large vessel occlusion (LVO) thrombectomy and to report on the procedural steps that led to perforation. METHODS: In this multicenter retrospective cohort study, data of consecutive patients with vessel perforation during thrombectomy between January 1, 2015 and September 30, 2022 were collected. The primary outcomes were independent functional outcome (ie, modified Rankin Scale 0-2) and all-cause mortality at 90 days. Binomial test, chi-squared test and t-test for unpaired samples were used for statistical analysis. RESULTS: During 25 769 thrombectomies (5124 MeVO, 20 645 LVO) in 25 stroke centers, perforation occurred in 335 patients (1.3%; mean age 72 years, 62% female). Perforation occurred more often in MeVO thrombectomy (2.4%) than in LVO thrombectomy (1.0%, p<0.001). More MeVO than LVO patients with perforation achieved functional independence at 3 months (25.7% vs 10.9%, p=0.001). All-cause mortality did not differ between groups (overall 51.6%). Navigation beyond the occlusion and retraction of stent retriever/aspiration catheter were the two most common procedural steps that led to perforation. CONCLUSIONS: In our cohort, perforation was approximately twice as frequent in MeVO than in LVO thrombectomy. Efforts to optimize the procedure may focus on navigation beyond the occlusion site and retraction of stent retriever/aspiration catheter. Further research is necessary in order to identify thrombectomy candidates at high risk of intraprocedural perforation and to provide data on the effectiveness of endovascular countermeasures.

Mechanical thrombectomy for in-hospital stroke: data from the Italian Registry of Endovascular Treatment in Acute Stroke.

BACKGROUND: The benefit, safety, and time intervals of mechanical thrombectomy (MT) in patients with in-hospital stroke (IHS) are unclear. We sought to evaluate the outcomes and treatment times for IHS patients compared with out-of-hospital stroke (OHS) patients receiving MT. METHODS: We analyzed data from the Italian Registry of Endovascular Treatment in Acute Stroke (IRETAS) between 2015 and 2019. We compared the functional outcomes (modified Rankin Scale (mRS) scores) at 3 months, recanalization rates, and symptomatic intracranial hemorrhage (sICH) after MT. Time intervals from stroke onset-to-imaging, onset-to-groin, and onset-to-end MT were recorded for both groups, as were door-to-imaging and door-to-groin for OHS. A multivariate analysis was performed. RESULTS: Of 5619 patients, 406 (7.2%) had IHS. At 3 months, IHS patients had a lower rate of mRS 0-2 (39% vs 48%, P<0.001) and higher mortality (30.1% vs 19.6%, P<0.001). Recanalization rates and sICH were similar. Time intervals (min, median (IQR)) from stroke onset-to-imaging, onset-to-groin, and onset-to-end MT were favorable for IHS (60 (34-106) vs 123 (89-188.5); 150 (105-220) vs 220 (168-294); 227 (164-303) vs 293 (230-370); all P<0.001), whereas OHS had lower door-to-imaging and door-to-groin times compared with stroke onset-to-imaging and onset-to-groin for IHS (29 (20-44) vs 60 (34-106), P<0.001; 113 (84-151) vs 150 (105-220); P<0.001). After adjustment, IHS was associated with higher mortality (aOR 1.77, 95% CI 1.33 to 2.35, P<0.001) and a shift towards worse functional outcomes in the ordinal analysis (aOR 1.32, 95% CI 1.06 to 1.66, P=0.015). CONCLUSION: Despite favorable time intervals for MT, IHS patients had worse functional outcomes than OHS patients. Delays in IHS management were detected.

Neural network-derived perfusion maps: A model-free approach to computed tomography perfusion in patients with acute ischemic stroke.

Objective: In this study, we investigate whether a Convolutional Neural Network (CNN) can generate informative parametric maps from the pre-processed CT perfusion data in patients with acute ischemic stroke in a clinical setting. Methods: The CNN training was performed on a subset of 100 pre-processed perfusion CT dataset, while 15 samples were kept for testing. All the data used for the training/testing of the network and for generating ground truth (GT) maps, using a state-of-the-art deconvolution algorithm, were previously pre-processed using a pipeline for motion correction and filtering. Threefold cross validation had been used to estimate the performance of the model on unseen data, reporting Mean Squared Error (MSE). Maps accuracy had been checked through manual segmentation of infarct core and total hypo-perfused regions on both CNN-derived and GT maps. Concordance among segmented lesions was assessed using the Dice Similarity Coefficient (DSC). Correlation and agreement among different perfusion analysis methods were evaluated using mean absolute volume differences, Pearson correlation coefficients, Bland-Altman analysis, and coefficient of repeatability across lesion volumes. Results: The MSE was very low for two out of three maps, and low in the remaining map, showing good generalizability. Mean Dice scores from two different raters and the GT maps ranged from 0.80 to 0.87. Inter-rater concordance was high, and a strong correlation was found between lesion volumes of CNN maps and GT maps (0.99, 0.98, respectively). Conclusion: The agreement between our CNN-based perfusion maps and the state-of-the-art deconvolution-algorithm perfusion analysis maps, highlights the potential of machine learning methods applied to perfusion analysis. CNN approaches can reduce the volume of data required by deconvolution algorithms to estimate the ischemic core, and thus might allow the development of novel perfusion protocols with lower radiation dose deployed to the patient.

Successful 8-year use of Venous Window Needle Guide for deep arteriovenous fistula cannulation.

We describe the case of a patient who had been on hemodialysis for 8 years using a native arteriovenous fistula cannulated through the Venous Window Needle Guide™ device (VWING). The overall outcome was excellent and complication-free with intact state of the underlying vessel and a high degree of patient satisfaction. The patient was able to carry out self-cannulation without any difficulty almost from the very beginning. The current unavailability of VWING is a missed opportunity in the field of vascular access.

Silk Vista Baby flow diverter stent for ruptured intracranial aneurysms: a retrospective observational study.

PURPOSE: Flow diversion changed the approach to complex intracranial aneurysms, leading to a widespread use and a rapid technological evolution. Indeed, indications continued to expand, including ruptured intracranial aneurysms in selected cases. Recently, new devices have been designed specifically to target smaller vessels. Therefore, we conducted a multicenter study to evaluate clinical outcome, complications, and occlusion rate of patients with ruptured aneurysms treated with new generation low profile Silk Vista Baby (SVB) flow diverter stent (FD). METHODS: We performed a retrospective observational study on consecutive patients who underwent treatment with SVB for ruptured aneurysms at 12 Italian centers. Primary end point was favorable clinical outcome rate, defined as modified ranking score (mRS) of 0-2 at the 3 months. Secondary outcomes were complication rate, aneurysm re-rupture, and complete aneurysm occlusion at last radiological follow-up. RESULTS: Twenty-five patients were included; at 3 months' follow-up, 19 patients (79.1%) had favorable clinical outcome (mRS 0-2). Three patients (12.5%) died during follow-up. In-stent thrombosis occurred in two cases (8.3%), managed with glycoprotein IIb/IIIA and intra-stent angioplasty, without clinical consequences. In 18 (85.7%) patients, complete occlusion at 3 months was demonstrated. No rebleeding occurred during follow-up. Presentation with unfavorable World Federation of Neurosurgical Societies grading system (WFNS) and posterior circulation location were both significantly correlated with unfavorable clinical outcome (p = 0.005 and p = 0.02). CONCLUSIONS: Our data suggests that low profile FD treatment of ruptured intracranial aneurysms located distally of the circle of Willis is feasible. New generation low profile FD may represent an alternative option in carefully selected cases.

Massive cerebral venous sinus thrombosis in vaccine-induced immune thrombotic thrombocytopenia after ChAdOx1 nCoV-19 serum: case report of a successful multidisciplinary approach.

We report a case of massive cerebral venous sinus thrombosis in the contest of vaccine-induced immune thrombotic thrombocytopenia that required the rapid coordination of many specialists from different departments, notably emergency, neurology, neuroradiology, hematology, and neurosurgery. The patient was rapidly treated with steroids, immunoglobulin, and fondaparinux. She underwent within 6 h after hospital admission a mechanical thrombectomy in order to allow flow restoration in cerebral venous systems. Neuroendovascular treatment in cerebral venous thrombosis related to VITT has never been described before. It can represent a complementary tool along with the other therapies and a multidisciplinary approach.

Treatment of Acute Necrotising Pancreatitis and Its Complications: The Surgeon's Perspective.

Acute necrotising pancreatitis (ANP) is associated with high complication and mortality rates. It is still difficult for the surgeon to choose and schedule the most appropriate treatment. Compared to the past, the current minimally invasive "step-up" approach enables better outcomes in terms of morbidity/mortality, notwithstanding long periods of hospitalisation, and above all ensures better levels of residual pancreatic function. We hereby report the case of a patient hospitalised in our division for approximately 4 months with a diagnosis of ANP complicated by infection and late bleeding, handled with a sequential approach.

Use of a 4 mm Amplatzer Vascular Plug II in the treatment of a renal arteriovenous fistula: a case report.

BACKGROUND: We report the use of a 4 mm vascular Amplatzer for the occlusion of a renal arterovenous fistula between the renal artery, at the hylum trifurcation point, and an aneurismatic vein draining into the main renal vein, where there was no possibility to use any other device from the venous side, because of the diameter and the high flow, neither from the arterious side without sacrificing lobar branches. The device was implanted at the exact point of communication, like a patent foramen ovale occluder, with the distal disc into the artery lumen and the other two proximal discs into the venous side. CASE PRESENTATION: A 34-years-old Caucasian woman suffered several episodes of paroxysmal supraventricular tachycardia associated with dyspnoea, after the onset of post-pregnancy hypertension. She underwent CTA, spectral Doppler sonography and angiography which showed a renal arteriovenous fistula (RAVF) between the renal artery, at the hylum trifurcation point, and an extremely ectatic vein draining into the main renal vein of the right kidney. With both arterial and venous access, the RAVF was selectively embolized using a 4 × 6 mm Amplatzer Vascular Plug II, released into the communication between artery and vein ensuring the patency of vessels involved. The RAVF was almost completely excluded and the hemodynamic effects associated were also corrected. CONCLUSIONS: The use of this device, though in an alternative way, allowed the exclusion of the high flow A-V fistula without sacrificing any parent renal vessel and preserving the renal function.

Emotional imagination of negative situations: Functional neuroimaging in anorexia and bulimia.

AIM: The present study aims to extend the knowledge of the neural correlates of emotion processing in first episode subjects affected by anorexia nervosa (AN) or bulimia nervosa (BN). We applied an emotional distress paradigm targeting negative emotions thought to be relevant for interpersonal difficulties and therapeutic resistance mechanisms. METHODS: The current study applied to 44 female participants with newly diagnosed AN or BN and 20 matched controls a neuroimaging paradigm eliciting affective responses. The measurements also included an extensive assessment comprising clinical scales, neuropsychological tests, measures of emotion processing and empathy. RESULTS: AN and BN did not differ from controls in terms of emotional response, emotion matching, self-reported empathy and cognitive performance. However, eating disorder and psychopathological clinical scores, as well as alexithymia levels, were increased in AN and BN. On a neural level, no significant group differences emerged, even when focusing on a region of interest selected a priori: the amygdala. Some interesting findings put in relation the hippocampal activity with the level of Body Dissatisfaction of the participants, the relative importance of the key nodes for the common network in the decoding of different emotions (BN = right amygdala, AN = anterior cingulate area), and the qualitative profile of the deactivations. CONCLUSIONS: Our data do not support the hypothesis that participants with AN or BN display reduced emotional responsiveness. However, peculiar characteristics in emotion processing could be associated to the three different groups. Therefore, relational difficulties in eating disorders, as well as therapeutic resistance, could be not secondary to a simple difficulty in feeling and identifying basic negative emotions in AN and BN participants.

Shape memory polymer ovarian vein embolisation in a patient with nickel allergy.

BACKGROUND: Ovarian vein embolization in pelvic varicocele is usually obtained using nitinol coils. These devices can not be used in patients with proven nickel allergy. CASE PRESENTATION: Shape memory polymer is a new embolic material available to interventionalists. A patient presented with pelvic congestion syndrome requiring embolisation of the left ovarian vein. The target vessel consisted of two twisted branches, each 5-6 mm in diameter. The patient also had a known allergy to nickel. Considering the anatomy and allergy status, embolisation with polyurethane shape memory polymer vascular plugs was considered a good case strategy. The embolisation procedure was technically successful with the deployment of two shape memory polymer plugs into each of the two left ovarian vein branches. Follow-up magnetic resonance imaging at 4 months showed sustained occlusion of the treated vessels and the patient showed no signs of allergy to the implanted material. CONCLUSIONS: In conclusion, our case presented an opportunity to utilise a new embolic material and achieve a good outcome in a patient with an allergy that may have resulted in complications when using metallic implants.

Perfusion-computed tomography for simultaneous bilateral middle cerebral artery occlusion.

Bilateral simultaneous middle cerebral artery occlusion is a rare condition that may lead to severe neurological disability or death, thus requiring rapid intervention in order to restore vessels patency and brain perfusion. Perfusion-computed tomography is demonstrated to be a fundamental tool for selecting stroke patients candidate to mechanical thrombectomy, but its role for guiding the optimal strategy of endovascular treatment in concomitant multivessel cerebral occlusion has never been reported. We describe a case of bilateral middle cerebral artery occlusion in which perfusion-computed tomography was crucial both for addressing to endovascular procedure and planning the sequence treatment of mechanical thrombectomies.

Mechanical Thrombectomy for Acute Intracranial Carotid Occlusion with Patent Intracranial Arteries : The Italian Registry of Endovascular Treatment in Acute Stroke.

PURPOSE: Intracranial carotid artery occlusion represents an underinvestigated cause of acute ischemic stroke as well as an indication for mechanical thrombectomy. We investigated baseline and procedural characteristics, outcomes and predictors of outcome in patients with acute ischemic stroke secondary to intracranial carotid artery occlusion. METHODS: A retrospective analysis of the Italian Registry of Endovascular Treatment in Acute Stroke was performed. Patients with intracranial carotid artery occlusion (infraclinoid and supraclinoid) with or without cervical artery occlusion but with patent intracranial arteries were included. The 3­month functional independence, mortality, successful reperfusion and symptomatic intracranial hemorrhage were evaluated. RESULTS: Intracranial carotid artery occlusion with patent intracranial arteries was diagnosed in 387 out of 4940 (7.8%) patients. The median age was 74 years and median baseline National Institute of Health Stroke Scale (NIHSS) was 18. Functional independence was achieved in 130 (34%) patients, successful reperfusion in 289 (75%) and symptomatic intracranial hemorrhage in 33 (9%), whereas mortality occurred in 111 (29%) patients. In univariate analysis functional independence was associated with lower age, lower NIHSS at presentation, higher rate of successful reperfusion and lower rate of symptomatic intracranial hemorrhage. Multivariable regression analysis found age (odds ratio, OR:1.03; P = 0.006), NIHSS at presentation (OR: 1.07; P < 0.001), diabetes (OR: 2.60; P = 0.002), successful reperfusion (OR:0.20; P < 0.001) and symptomatic intracranial hemorrhage (OR: 4.17; P < 0.001) as the best independent predictors of outcome. CONCLUSION: Our study showed a not negligible rate of intracranial carotid artery occlusion with patent intracranial arteries, presenting mostly as severe stroke, with an acceptable rate of 3­month functional independence. Age, NIHSS at presentation and successful reperfusion were the best independent predictors of outcome.

Soil carbon dioxide venting through rice roots.

The growth of rice in submerged soils depends on its ability to form continuous gas channels-aerenchyma-through which oxygen (O2 ) diffuses from the shoots to aerate the roots. Less well understood is the extent to which aerenchyma permits venting of respiratory carbon dioxide (CO2 ) in the opposite direction. Large, potentially toxic concentrations of dissolved CO2 develop in submerged rice soils. We show using X-ray computed tomography and image-based mathematical modelling that CO2 venting through rice roots is far greater than thought hitherto. We found rates of venting equivalent to a third of the daily CO2 fixation in photosynthesis. Without this venting through the roots, the concentrations of CO2 and associated bicarbonate (HCO3- ) in root cells would have been well above levels known to be toxic to roots. Removal of CO2 and hence carbonic acid (H2 CO3 ) from the soil was sufficient to increase the pH in the rhizosphere close to the roots by 0.7 units, which is sufficient to solubilize or immobilize various nutrients and toxicants. A sensitivity analysis of the model showed that such changes are expected for a wide range of plant and soil conditions.

The "milky way" galaxy of HIV-related central nervous system immune reaction syndromes.

The landscape of central nervous system HIV infection is rapidly changing, leading to the recognition of a new constellation of overlapping syndromes and to a better insight for the elder ones. Among these, progressive multifocal leukoencephalopathy (PML) still poses several diagnostic and therapeutic challenges; nevertheless, recent developments in understanding PML in patients with multiple sclerosis may have benefitted HIV-positive patients suffering from PML too. We describe a peculiar case of PML-immune reconstitution inflammatory syndrome (IRIS) presenting a punctate pattern with "milky way" appearance on magnetic resonance imaging. Despite the fact that brain imaging and histopathology remain the mainstays for extricating through the expanding galaxy of HIV-related central nervous system dysimmune syndromes and although punctate pattern has been already well acknowledged as a suggestive finding of PML among patients on natalizumab, this radiological presentation is still poorly recognised in AIDS-related PML cases, leading to possible life-threatening diagnostic delays. This is also the first report about intravenous immunoglobulin treatment in AIDS-related PML-IRIS; the favourable clinical and radiological outcome of our case and the preliminary administrations of intravenous immunoglobulins in natalizumab-associated PML-IRIS from literature support probable benefits also among HIV-positive patients.

A Model of Uranium Uptake by Plant Roots Allowing for Root-Induced Changes in the soil.

We develop a model with which to study the poorly understood mechanisms of uranium (U) uptake by plants. The model is based on equations for transport and reaction of U and acids and bases in the rhizosphere around cylindrical plant roots. It allows for the speciation of U with hydroxyl, carbonate, and organic ligands in the soil solution; the nature and kinetics of sorption reactions with the soil solid; and the effects of root-induced changes in rhizosphere pH. A sensitivity analysis showed the importance of soil sorption and speciation parameters as influenced by pH and CO2 pressure; and of root geometry and root-induced acid-base changes linked to the form of nitrogen taken up by the root. The root absorbing coefficient for U, relating influx to the concentration of U species in solution at the root surface, was also important. Simplified empirical models of U uptake by different plant species and soil types need to account for these effects.