Exploring the short linear motif-mediated protein-protein interactions of CrkL through ProP-PD

Adaptor proteins play a pivotal role in cellular signaling mediating a multitude of protein-protein interaction critical for cellular homeostasis. Dysregulation of these interactions has been linked to the onset of various cancer pathologies and exploited by viral pathogens during host cell takeover. CrkL is an adaptor protein composed of an N-terminal SH2 domain followed by two SH3 domains that mediate interactions with diverse partners through the recognition of specific binding motifs. In this study, we employed proteomic peptide-phage display (ProP-PD) to comprehensively explore the short linear motif (SLiM)-based interactions of CrkL. Furthermore, we scrutinized how the binding affinity for selected peptides was influenced in the context of the full-length CrkL versus the isolated N-SH3 domain. Importantly, our results provided insights into SLiM-binding sites within previously reported interactors, as well as revealing novel human and viral ligands, expanding our understanding of the interactions mediated by CrkL and highlighting the significance of SLiM-based interactions in mediating adaptor protein function, with implications for cancer and viral pathologies.

Identification of motif-based interactions between SARS-CoV-2 protein domains and human peptide ligands pinpoint antiviral targets

The virus life cycle depends on host-virus protein-protein interactions, which often involve a disordered protein region binding to a folded protein domain. Here, we used proteomic peptide phage display (ProP-PD) to identify peptides from the intrinsically disordered regions of the human proteome that bind to folded protein domains encoded by the SARS-CoV-2 genome. Eleven folded domains of SARS-CoV-2 proteins were found to bind 281 peptides from human proteins, and affinities of 31 interactions involving eight SARS-CoV-2 protein domains were determined (KD ∼ 7-300 μM). Key specificity residues of the peptides were established for six of the interactions. Two of the peptides, binding Nsp9 and Nsp16, respectively, inhibited viral replication. Our findings demonstrate how high-throughput peptide binding screens simultaneously identify potential host-virus interactions and peptides with antiviral properties. Furthermore, the high number of low-affinity interactions suggest that overexpression of viral proteins during infection may perturb multiple cellular pathways.

Large-scale phosphomimetic screening identifies phospho-modulated motif-based protein interactions

Phosphorylation is a ubiquitous post-translation modification that regulates protein function by promoting, inhibiting or modulating protein-protein interactions. Hundreds of thousands of phosphosites have been identified but the vast majority have not been functionally characterised and it remains a challenge to decipher phosphorylation events modulating interactions. We generated a phosphomimetic proteomic peptide-phage display library to screen for phosphosites that modulate short linear motif-based interactions. The peptidome covers ~13,500 phospho-serine/threonine sites found in the intrinsically disordered regions of the human proteome. Each phosphosite is represented as wild-type and phosphomimetic variant. We screened 71 protein domains to identify 248 phosphosites that modulate motif-mediated interactions. Affinity measurements confirmed the phospho-modulation of 14 out of 18 tested interactions. We performed a detailed follow-up on a phospho-dependent interaction between clathrin and the mitotic spindle protein hepatoma-upregulated protein (HURP), demonstrating the essentiality of the phospho-dependency to the mitotic function of HURP. Structural characterisation of the clathrin-HURP complex elucidated the molecular basis for the phospho-dependency. Our work showcases the power of phosphomimetic ProP-PD to discover novel phospho-modulated interactions required for cellular function.

The next wave of interactomics: Mapping the SLiM-based interactions of the intrinsically disordered proteome

Short linear motifs (SLiMs) are a unique and ubiquitous class of protein interaction modules that perform key regulatory functions and drive dynamic complex formation. For decades, interactions mediated by SLiMs have accumulated through detailed low-throughput experiments. Recent methodological advances have opened this previously underexplored area of the human interactome to high-throughput protein-protein interaction discovery. In this article, we discuss that SLiM-based interactions represent a significant blind spot in the current interactomics data, introduce the key methods that are illuminating the elusive SLiM-mediated interactome of the human cell on a large scale, and discuss the implications for the field.

SLiM-binding pockets: an attractive target for broad-spectrum antivirals

Short linear motif (SLiM)-mediated interactions offer a unique strategy for viral intervention due to their compact interfaces, ease of convergent evolution, and key functional roles. Consequently, many viruses extensively mimic host SLiMs to hijack or deregulate cellular pathways and the same motif-binding pocket is often targeted by numerous unrelated viruses. A toolkit of therapeutics targeting commonly mimicked SLiMs could provide prophylactic and therapeutic broad-spectrum antivirals and vastly improve our ability to treat ongoing and future viral outbreaks. In this opinion article, we discuss the therapeutic relevance of SLiMs, advocating their suitability as targets for broad-spectrum antiviral inhibitors.

Large-scale phage-based screening reveals extensive pan-viral mimicry of host short linear motifs

Viruses mimic host short linear motifs (SLiMs) to hijack and deregulate cellular functions. Studies of motif-mediated interactions therefore provide insight into virus-host dependencies, and reveal targets for therapeutic intervention. Here, we describe the pan-viral discovery of 1712 SLiM-based virus-host interactions using a phage peptidome tiling the intrinsically disordered protein regions of 229 RNA viruses. We find mimicry of host SLiMs to be a ubiquitous viral strategy, reveal novel host proteins hijacked by viruses, and identify cellular pathways frequently deregulated by viral motif mimicry. Using structural and biophysical analyses, we show that viral mimicry-based interactions have similar binding strength and bound conformations as endogenous interactions. Finally, we establish polyadenylate-binding protein 1 as a potential target for broad-spectrum antiviral agent development. Our platform enables rapid discovery of mechanisms of viral interference and the identification of potential therapeutic targets which can aid in combating future epidemics and pandemics.

Proteome-scale mapping of binding sites in the unstructured regions of the human proteome

Specific protein-protein interactions are central to all processes that underlie cell physiology. Numerous studies have together identified hundreds of thousands of human protein-protein interactions. However, many interactions remain to be discovered, and low affinity, conditional, and cell type-specific interactions are likely to be disproportionately underrepresented. Here, we describe an optimized proteomic peptide-phage display library that tiles all disordered regions of the human proteome and allows the screening of ~ 1,000,000 overlapping peptides in a single binding assay. We define guidelines for processing, filtering, and ranking the results and provide PepTools, a toolkit to annotate the identified hits. We uncovered >2,000 interaction pairs for 35 known short linear motif (SLiM)-binding domains and confirmed the quality of the produced data by complementary biophysical or cell-based assays. Finally, we show how the amino acid resolution-binding site information can be used to pinpoint functionally important disease mutations and phosphorylation events in intrinsically disordered regions of the proteome. The optimized human disorderome library paired with PepTools represents a powerful pipeline for unbiased proteome-wide discovery of SLiM-based interactions.

Large scale discovery of coronavirus-host factor protein interaction motifs reveals SARS-CoV-2 specific mechanisms and vulnerabilities

Viral proteins make extensive use of short peptide interaction motifs to hijack cellular host factors. However, most current large-scale methods do not identify this important class of protein-protein interactions. Uncovering peptide mediated interactions provides both a molecular understanding of viral interactions with their host and the foundation for developing novel antiviral reagents. Here we describe a viral peptide discovery approach covering 23 coronavirus strains that provides high resolution information on direct virus-host interactions. We identify 269 peptide-based interactions for 18 coronaviruses including a specific interaction between the human G3BP1/2 proteins and an ΦxFG peptide motif in the SARS-CoV-2 nucleocapsid (N) protein. This interaction supports viral replication and through its ΦxFG motif N rewires the G3BP1/2 interactome to disrupt stress granules. A peptide-based inhibitor disrupting the G3BP1/2-N interaction dampened SARS-CoV-2 infection showing that our results can be directly translated into novel specific antiviral reagents.

Screening Intrinsically Disordered Regions for Short Linear Binding Motifs

The intrinsically disordered regions of the proteome are enriched in short linear motifs (SLiMs) that serve as binding sites for peptide binding proteins. These interactions are often of low-to-mid micromolar affinities and are challenging to screen for experimentally. However, a range of dedicated methods have been developed recently, which open for screening of SLiM-based interactions on large scale. A variant of phage display, termed proteomic peptide phage display (ProP-PD), has proven particularly useful for the purpose. Here, we describe a complete high-throughput ProP-PD protocol for screening intrinsically disordered regions for SLiMs. The protocol requires some basic bioinformatics skills for the design of the library and for data analysis but can be performed in a standard biochemistry lab. The protocol starts from the construction of a library, followed by the high-throughput expression and purification of bait proteins, the phage selection, and the analysis of the binding-enriched phage pools using next-generation sequencing. As the protocol generates rather large data sets, we also emphasize the importance of data management and storage.

Recombinant antibody against Trypanosoma cruzi from patients with chronic Chagas heart disease recognizes mammalian nervous system

BACKGROUND

To deeply understand the role of antibodies in the context of Trypanosoma cruzi infection, we decided to characterize A2R1, a parasite antibody selected from single-chain variable fragment (scFv) phage display libraries constructed from B cells of chronic Chagas heart disease patients.

METHODS

Immunoblot, ELISA, cytometry, immunofluorescence and immunohistochemical assays were used to characterize A2R1 reactivity. To identify the antibody target, we performed an immunoprecipitation and two-dimensional electrophoresis coupled to mass spectrometry and confirmed A2R1 specific interaction by producing the antigen in different expression systems. Based on these data, we carried out a comparative in silico analysis of the protein target´s orthologues, focusing mainly on post-translational modifications.

FINDINGS

A2R1 recognizes a parasite protein of ~50 kDa present in all life cycle stages of T. cruzi, as well as in other members of the kinetoplastid family, showing a defined immunofluorescence labeling pattern consistent with the cytoskeleton. A2R1 binds to tubulin, but this interaction relies on its post-translational modifications. Interestingly, this antibody also targets mammalian tubulin only present in brain, staining in and around cell bodies of the human peripheral and central nervous system.

INTERPRETATION

Our findings demonstrate for the first time the existence of a human antibody against T. cruzi tubulin capable of cross-reacting with a human neural protein. This work re-emphasizes the role of molecular mimicry between host and parasitic antigens in the development of pathological manifestations of T. cruzi infection.

An update on genetic variants of the NKX2-5

NKX2-5 is a homeodomain transcription factor that plays a crucial role in heart development. It is the first gene where a single genetic variant (GV) was found to be associated with congenital heart diseases in humans. In this study, we carried out a comprehensive survey of NKX2-5 GVs to build a unified, curated, and updated compilation of all available GVs. We retrieved a total of 1,380 unique GVs. From these, 970 had information on their frequency in the general population and 143 have been linked to pathogenic phenotypes in humans. In vitro effect was ascertained for 38 GVs. The homeodomain had the biggest cluster of pathogenic variants in the protein: 49 GVs in 60 residues, 23 in its third α-helix, where 11 missense variants may affect protein-DNA interaction or the hydrophobic core. We also pinpointed the likely location of pathogenic GVs in four linear motifs. These analyses allowed us to assign a putative explanation for the effect of 90 GVs. This study pointed to reliable pathogenicity for GVs in helix 3 of the homeodomain and may broaden the scope of functional and structural studies that can be done to better understand the effect of GVs in NKX2-5 function.

CYP21A2 mutation update: Comprehensive analysis of databases and published genetic variants

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders of adrenal steroidogenesis. Disorders in steroid 21-hydroxylation account for over 95% of patients with CAH. Clinically, the 21-hydroxylase deficiency has been classified in a broad spectrum of clinical forms, ranging from severe or classical, to mild late onset or non-classical. Known allelic variants in the disease causing CYP21A2 gene are spread among different sources. Until recently, most variants reported have been identified in the clinical setting, which presumably bias described variants to pathogenic ones, as those found in the CYPAlleles database. Nevertheless, a large number of variants are being described in massive genome projects, many of which are found in dbSNP, but lack functional implications and/or their phenotypic effect. In this work, we gathered a total of 1,340 GVs in the CYP21A2 gene, from which 899 variants were unique and 230 have an effect on human health, and compiled all this information in an integrated database. We also connected CYP21A2 sequence information to phenotypic effects for all available mutations, including double mutants in cis. Data compiled in the present work could help physicians in the genetic counseling of families affected with 21-hydroxylase deficiency.

Hypertensive Encephalopathy: Clinical and Neuroradiological Findings

Hypertensive encephalopathy is a syndrome consisting of headache, seizures, visual changes, and other neurologic disturbances in patients with elevated systemic blood pressure. The purpose of this study was to analyse the clinical and neuroradiological findings in nine patients with hypertensive encephalopathy, observed in five years.

CT (n = 13), and MR (n = 12), examinations performed in these patients before and after resolution of symptoms were reviewed. Six had the preeclampsia-eclampsia syndrome, and three had hypertensive encephalopathy due to other causes. CT and MR findings in all patients having these examinations were indicative of oedema in the cortex and subcortical white matter in the occipital lobes. Two of the nine patients also had similar findings in the cerebellum and frontal lobes.

The findings on the CT and MR studies resolved on follow-up examinations performed after the hypertension was corrected.

Our results suggest that the radiological findings associated with hypertensive encephalopathy in the appropriate clinical setting are very useful to achieve an early diagnosis.

L'angio-TC nel riscontro e nell'analisi delle caratteristiche delle lesioni aneurismatiche intracraniche dei pazienti con ESA

È stato eseguito uno studio retrospettivo per valutare l'utilità dell'angio-TC nel riscontro e nell'analisi delle caratteristiche delle lesioni aneurismatiche intracraniche nei pazienti con ESA, usando l'angiografia digitale (AD) come “gold standard”.

È stato preso in esame un gruppo di 97 pazienti con emorragia sub-aracnoidea, e sono stati esaminati con angio-TC entro 12 ore dall'evento acuto; 23 hanno eseguito solo l'angio-TC, mentre 74 pazienti hanno eseguito sia l'angio-TC che l'AD; l'AD è stata eseguita mediamente entro 24 ore. Nei 74 pazienti hanno eseguito sia l'angio-TC che l'AD, abbiamo avuto un riscontro di 69 aneurismi (6 pazienti avevano una doppia lesione aneurismatica ed in una paziente ne sono state riscontrate quattro) e l'assenza di aneurismi in 14 pazienti. In cinque casi l'angio-TC non ha evidenziato l'aneurisma, riscontrato poi con l'AD.

I falsi negativi erano dovuti in un caso ad un errore nel calcolo del ritardo d'iniezione, in un secondo caso la lesione aneurismatica a carico della PICA non si è opacizzata. L'AD è stata eseguita il giorno dopo e nel frattempo le condizioni di circolo e dei vasi potrebbero essere cambiate. Nei restanti casi si trattava di aneurismi non ben visualizzati per la marcata tortuosità del vaso associata alle piccole dimensioni delle lesioni ed alla presenza di strutture ossee molto vicine alla lesione.

Pertanto la sensibilità e la specificità dell'angio-CT nel riscontro degli aneurismi sono rispettivamente del 96% e del 100%, ed il valore predittivo globale dell'esame è del 96%.

Tale metodica non invasiva è risultata quindi veloce, affidabile, ricca di informazioni e spesso conclusiva nell'iter diagnostico dei pazienti con ESA, con particolare utilità nella gestione della urgenza.

Trattamento percutaneo dell'ernia discale lombare con iniezione intradiscale di miscela di ozono

Negli ultimi anni si sono moltiplicate le segnalazioni dell'utilità dell'ossigeno-ozono terapia intradiscale, che abbiamo iniziato nel 1997 con iniezione intradiscale e paraspinale.

Dal Dicembre 1997 all'Agosto 2000 sono stati trattati 444 pazienti, di cui maschi 240 e femmine 204, per complessivi 723 trattamenti.

Vengono qui presentati 191 pazienti sottoposti a trattamento con unica seduta, dei quali si è completato il controllo a sei mesi.

Nel complesso i risultati ottimi - buoni raggiungono un livello percentuale che è appena inferiore a quello ottenibile con chemonucleolisi enzimatica; l'introduzione della ossigeno ozono terapia intradiscale nella nostra pratica clinica si è rivelata sicuramente positiva.

Effetti dell'ozono sul nucleo polposo: Reperti anatomo-patologici su un caso operato

Il meccanismo di azione dell'ozono sul nucleo polposo è stato variamente ipotizzato su basi teoriche e sperimentali.

Gli autori descrivono un caso di intervento chirurgico su disco sottoposto a ozonoterapia intradiscale, in cui il materiale discale asportato è stato giudicato dal chirurgo macroscopicamente diverso dal solito ed è stato inviato all'anatomo-patologo per una valutazione istologica.

Si riportano i risultati di tale analisi istologica.

Lo studio neuroradiologico dell'idrocefalo Valutazione pre- e post-chirurgica con particolare riguardo all'approccio endoscopico

La studio neuroradiologico dell'idrocefalo nell'epoca dei trattamenti chirurgici endoscopici si arricchisce di nuovi quesiti e di nuovi segni.

Se la TC mantiene la sua validità nella prima diagnosi di idrocefalo e nello studio delle complicanze immediate dei trattamenti endoscopici, perde il ruolo preminente che aveva nei controlli post-operatori a medio e lungo termine.

La RM è l'esame di scelta in fase prechirurgica, per la pianificazione dell'intervento endoscopico, con lo studio dell'anatomia della regione del III ventricolo. Lo stesso discorso vale per i controlli post-chirurgici delle terzoventricolostomie, vista la maggiore importanza del dato funzionale della pervietà della stomia rispetto al semplice dato morfologico della variazione della volumetria ventricolare.

Gli studi quantitativi con sequenze specifiche per il flusso e con sincronizzazione cardiaca, eventualmente abbinati alla funzione cine, sono indubbiamente accurati, raffinati ed eleganti, ma non indispensabili, nella pratica clinica, per lo studio del flusso liquorale; infatti non si è ancora dimostrata una loro significativa maggiore sensibilità rispetto ai dati qualitativi (flusso si/flusso no) ottenibili con normali sequenze FSE e TSE T2 w.

Reflections on the Nucleus Pulposus

The intervertebral disc is usually divided into two parts, the anulus fibrosus and the nucleus pulposus. However, they are not considered two separate anatomic parts since one is essentially part of the other and this should be borne in mind to understand the process of ageing.

The intervertebral disc should therefore be thought of as a dynamically evolving anatomo-functional unit. The dynamics of this process were investigated by studying the histobiochemistry of the acellular matrix of the joint cartilage in general and that of the intervertebral disc in particular to understand the effects of this arrangement on the stuctural changes to the disc induced by biomechanical stress, especially during ageing. Lastly, we focussed on the disc's nutritional mechanisms in order to examine “disc degeneration” as a sign of metabolic impairment of the nucleus pulposus and “disc regeneration”.

This concept was unknown until recently and is currently monitored in percutaneous controls following treatment for disc disease.

Cerebellar Mutism after Medulloblastoma Resection: Importance of MR Features

We describe the MR features which appeared after resection of a medulloblastoma in the posterior fossa in a boy who developed postoperative cerebellar mutism. The anatomical and physiopathological factors responsible for this disorder are discussed.

L'invecchiamento del rachide

Le modificazioni del rachide nell'invecchiamento sono note da tempo e vengono spesso raccolte sotto la definizione globale di artrosi vertebrale. La complessità e la molteplicità delle articolazioni intervertebrali ed intersegmentarie della colonna vertebrale, tuttavia, impongono una analisi più dettagliata dei singoli fenomeni che contribuiscono alla instaurazione di quelle modificazioni anatomo-patologiche proprie del complesso degenerativo rachideo senile.

Gli Autori procedono alla suddetta analisi, integrando i dati noti dalla Radiologia tradizionale e dalla TC con le acquisizioni più recenti della RM e con le basi patologiche macroscopiche e submacroscopiche rilevabili in letteratura. Tra i vari gruppi di patologia, quella che risulta più ricca di corrispondenze verificabili tra dati neuro-radiologici ed anatomici è quella riguardante l'unità funzionale disco-somatica, con particolare riguardo per l'osteocondrosi intervertebrale.

Attraverso l'approfondimento della patologia delle articolazioni cartilaginee, sinoviali e fibrose della colonna vertebrale, si tenta inoltre di fornire un quadro generale, finalistico, delle varie alterazioni vertebrali che sembra condurre verso una visione «protettiva» dell'artrosi vertebrale rispetto a danni più gravi, privilegiando in età senile la funzione statica rachidea rispetto a quella dinamica. Diventa a questo punto chiaro il perchè della difficoltà di tracciare una chiara linea distintiva tra alterazioni «parafisiologiche» dell'invecchiamento del rachide e alterazioni chiaramente patologiche.

Degenerazione dell'unità disco-somatica lombare

Gli autori, attraverso una revisione della letteratura ed uno studio retrospettivo su 125 esami RM, descrivono le alterazioni degenerative del rachide lombare in pazienti anziani, focalizzan-do l'attenzione sulla ricca semeiologia RM della patologia del complesso disco-somatico. Scopo del lavoro e quello di poter discernere le alterazioni a carattere francamente patologico da quelle che possono essere considerate segni del fisiologico invecchiamento rachideo. Viene in particolare evidenziato come la fissurazione radiale dell'anulus sia risultata, in base alla sua presenza significativamente più frequente nel gruppo dei pazienti sintomatici, il miglior segno predittivo di patologia estrusiva discale tra quelli esaminati.

Arthrosis: The Last Defence?

Can vertebral arthrosis be construed as the body's decision to privilege the spine's static function over its dynamic role when joint “hypermobility” linked to chronic load in old age could cause severe structural damage to the bony vertebral structures?

Why Does Disc-Root Conflict Generate Pain?

Root compression alone does not fully account for root pain following disc-root conflict, but it is nonetheless considered the main cause of pain. This short paper aims to explain that the origin of pain is multifactorial and inflammation probably predominates over merely mechanical mechanisms.

Management of unruptured brain aneurysms: retrospective analysis of a single centre experience

Embolization is very effective in preventing bleeding of unruptured aneurysms with lower rates of mortality and morbidity than surgical treatment. Neurosurgery remains, however, a good alternative. This retrospective analysis examined data stored the digital database of Bellaria Hospital Radiology Department, evaluating patients, treatments and devices used as well as outcomes and complications. Therapy should be tailored to each individual case to offer each patient the best treatment. Out of 265 unruptured intracranial aneurysms detected, 182 were treated by embolization. 16 cases presented complications (12 only radiologically found); severe clinical consequences occurred in 3%: one ischaemia and five haemorrhages. Conservative treatment was adopted in 21 patients. Long-term follow-up is mandatory as aneurysms could increase their size and develop an irregular morphology in ten years' time. Endovascular embolization is a very effective treatment with positive outcomes in the majority of cases and a percentage of retreatments of 8%. In order to increase the number of successful cases, a multidisciplinary cooperation with neurosurgeons is strongly recommended.

In vitro and in vivo studies with tetra-hydro-jasmonic acid (LR2412) reveal its potential to correct signs of skin ageing

BACKGROUND

LR2412, a synthetic derivative of jasmonic acid, improved the reconstruction and homeostasis of our organotypic skin models.

OBJECTIVES

The need for efficient 'anti-ageing' treatments, in particular for the management of photoaged skin, prompted us to investigate this new ingredient for its potential to correct signs of skin ageing in vitro and in vivo and to identify its mode of action.

RESULTS

In vitro, penetration of LR2412 was evaluated using a Franz diffusion cell on excised human skin. Its exfoliating properties and interactions with the stratum corneum were studied using electron microscopy and X-ray diffraction. Experiments were performed on a human reconstructed skin model. In vivo, the effects of LR2412 on steroid-induced skin atrophy, a clinical skin ageing model, were assessed vs. vehicle. A patch test study evaluated its effect on deposition of fibrillin-rich microfibrils in the papillary dermis in clinically photoaged volunteers. A clinical study on the appearance of crow's feet wrinkles was conducted over 3 months of daily application. Penetration studies revealed that LR2412 reaches viable epidermis and superficial dermis, which are skin targets of anti-ageing actives. Within the upper layers of the stratum corneum LR2412 accelerates desquamation and improves the mechanical properties. At the dermal-epidermal junction of reconstructed skin, collagen IV, laminin-5 and fibrillin were stimulated. In vivo, LR2412 reversed steroid-induced atrophy. The patch test model confirms the deposition of fibrillin-rich microfibrils, then an in use clinical study revealed that it reduced facial wrinkles.

CONCLUSIONS

The in vitro and in vivo data demonstrate that based on its multiple interactions within human skin, LR2412 has potential to partially correct the signs of ageing in intrinsically and photoaged skin.

CT angiography in an acute stroke protocol: correlation between occlusion site and outcome of intravenous thrombolysis

Thrombolysis with intravenous rt-PA is the current therapy for acute ischemic stroke. Unlike other outcome factors, relatively little is known about the prognostic value of the occlusion site on treatment outcome. We compared the effectiveness and safety of intravenous thrombolysis in patients with different levels of occlusion identified by CT angiography (CTA) in anterior circulation stroke, and analyzed the influence of the occlusion site on treatment outcome in relation to other outcome factors. We selected 71 patients from a stroke database collected between June 2007 and December 2011 at our hospital. All of the studied patients had anterior circulation stroke with intracranial occlusion detected by CTA and were treated with intravenous rt-PA. They were divided into two groups according to the site of occlusion along the middle cerebral artery course: proximal (carotid "T", complete M1 and mild M1 occlusions) and distal (M2/M3 occlusions). Treatment effectiveness was assessed by modified Rankin Scale (mRS) at three months, considering a positive outcome a mRS value ≤ 2. Treatment safety was assessed by evaluating the rate of hemorrhagic complications seen on unenhanced CT at 24 hours. Binary logistic regression was performed to evaluate the interaction between occlusion site and other variables such as sex, age, ASPECT score on admission and baseline NIHSS value in determining treatment outcome. The degree of effectiveness and safety differed when considering patients with proximal and distal occlusions. The percentage of successfully treated cases was 28.6% in the first group compared to 72% in the second, and the rate of hemorrhagic complications was 28.6% and 6% respectively. After adjustment for sex, age, ASPECT score on admission and baseline NIHSS value, occlusion site was the only variable significantly influencing treatment safety and, together with baseline NIHSS value, the only valid predictor of treatment effectiveness. We demonstrated a correlation between the site of arterial occlusion and outcome of intravenous thrombolysis. By helping the choice of the best therapeutic strategy depending on the identified occlusion site, CTA could be usefully added to the examinations included in the Stroke Protocol for the baseline evaluation of patients with suspected acute stroke.

Complications in the treatment of intracranial aneurysms with silk stents: an analysis of 30 consecutive patients

Flow-diverting stents (Silk and PED) have radically changed the approach to intracranial aneurysm treatment from the use of endosaccular materials to use of an extraaneurysmal endoluminal device. However, much debate surrounds the most appropriate indications for the use of FD stents and the problems raised by several possible complications.We analysed our technical difficulties and the early (less than ten days after treatment) and late complications encountered in 30 aneurysms treated comprising 13 giant lesions, 12 large, five with maximum diameters <10 mm and one blister-like aneurysm. In our experience the primary indications for the use of FD stents can be the symptomatic intracavernous giant aneurysms. Although the extracavernous carotid siphon aneurysms have major risk of bleeding, FD stents are indicated clearly explaining the risks to the patient in case of severe mass effect. There is a very complex assessment for aneurysms of the vertebrobasilar circulation.

Bacterial indicator of agricultural management for soil under no-till crop production

The rise in the world demand for food poses a challenge to our ability to sustain soil fertility and sustainability. The increasing use of no-till agriculture, adopted in many areas of the world as an alternative to conventional farming, may contribute to reduce the erosion of soils and the increase in the soil carbon pool. However, the advantages of no-till agriculture are jeopardized when its use is linked to the expansion of crop monoculture. The aim of this study was to survey bacterial communities to find indicators of soil quality related to contrasting agriculture management in soils under no-till farming. Four sites in production agriculture, with different soil properties, situated across a west-east transect in the most productive region in the Argentinean pampas, were taken as the basis for replication. Working definitions of Good no-till Agricultural Practices (GAP) and Poor no-till Agricultural Practices (PAP) were adopted for two distinct scenarios in terms of crop rotation, fertilization, agrochemicals use and pest control. Non-cultivated soils nearby the agricultural sites were taken as additional control treatments. Tag-encoded pyrosequencing was used to deeply sample the 16S rRNA gene from bacteria residing in soils corresponding to the three treatments at the four locations. Although bacterial communities as a whole appeared to be structured chiefly by a marked biogeographic provincialism, the distribution of a few taxa was shaped as well by environmental conditions related to agricultural management practices. A statistically supported approach was used to define candidates for management-indicator organisms, subsequently validated using quantitative PCR. We suggest that the ratio between the normalized abundance of a selected group of bacteria within the GP1 group of the phylum Acidobacteria and the genus Rubellimicrobium of the Alphaproteobacteria may serve as a potential management-indicator to discriminate between sustainable vs. non-sustainable agricultural practices in the Pampa region.

Aneurysmal bone cyst of the mobile spine: the therapeutic role of embolization

PURPOSE

Our aim is to define the role of embolization in the treatment of aneurysmal bone cyst of the spine in order to include this option in the decision making process.

METHODS

From April 2004 to November 2009, seven patients with primary aneurysmal bone cyst of the mobile spine treated by embolization have been prospectively followed-up. All clinical presentations and imagings were recorded. There are many options of embolic agent and techniques used, but all aim to devascularize the tumor. The therapeutic protocol includes: embolization repeated every 8 weeks until the appearance of radiographic signs of healing. Complications, rate of healing and clinical outcome were analyzed.

RESULTS

The number of embolizations varied from one to a maximum of seven without related intra- or post-operative complications. One patient, after four selective arterial embolizations, underwent direct percutaneous injection of embolic agents into the cyst. A clinical and radiographical response was achieved in all patients who were found alive and completely free of disease at mean follow-up of 46 months after last treatment and nobody crossed to surgical option.

CONCLUSION

Embolization seems to be the first option for spinal aneurysmal bone cyst treatment because of the best cost-to-benefit ratio. It is indicated in intact aneurysmal bone cyst, when diagnosis is certain, when technically feasible and safe and when no pathologic fracture or neurologic involvements are found. If embolization fails, other options for treatment would still be available.

Selective blockade of trypanosomatid protein synthesis by a recombinant antibody anti-Trypanosoma cruzi P2β protein

The ribosomal P proteins are located on the stalk of the ribosomal large subunit and play a critical role during the elongation step of protein synthesis. The single chain recombinant antibody C5 (scFv C5) directed against the C-terminal region of the Trypanosoma cruzi P2β protein (TcP2β) recognizes the conserved C-terminal end of all T. cruzi ribosomal P proteins. Although this region is highly conserved among different species, surface plasmon resonance analysis showed that the scFv C5 possesses very low affinity for the corresponding mammalian epitope, despite having only one single amino-acid change. Crystallographic analysis, in silico modelization and NMR assays support the analysis, increasing our understanding on the structural basis of epitope specificity. In vitro protein synthesis experiments showed that scFv C5 was able to specifically block translation by T. cruzi and Crithidia fasciculata ribosomes, but virtually had no effect on Rattus norvegicus ribosomes. Therefore, we used the scFv C5 coding sequence to make inducible intrabodies in Trypanosoma brucei. Transgenic parasites showed a strong decrease in their growth rate after induction. These results strengthen the importance of the P protein C terminal regions for ribosomal translation activity and suggest that trypanosomatid ribosomal P proteins could be a possible target for selective therapeutic agents that could be derived from structural analysis of the scFv C5 antibody paratope.

A minimally invasive treatment for lumbar disc herniation: DiscoGel® chemonucleolysis in patients unresponsive to chemonucleolysis with oxygen-ozone

A multitude of therapies is available to treat disc herniation, ranging from conservative methods (medication and physical therapy) to minimally invasive (percutaneous) treatments and surgery. O₂-O₃ chemonucleolysis (O₂-O₃ therapy) is one of the minimally invasive treatments with the best cost/benefit ratio and lowest complication rate. Another substance recently made available exploiting the chemical properties of pure ethanol is DiscoGel®, a radiopaque gelified ethanol more viscous than absolute alcohol 8,9. The present study aimed to assess the therapeutic outcome of DiscoGel® chemonucleolysis in patients with lumbar disc herniation unresponsive to O₂-O₃ therapy. Thirty-two patients aged between 20 and 79 years were treated by DiscoGel® chemonucleolysis between December 2008 and January 2010. The treatment was successful (improvement in pain) in 24 out of 32 patients. DiscoGel® is safe and easy to handle and there were no complications related to product diffusivity outside the treatment site. The therapeutic success rate of DiscoGel® chemonucleolysis in patients unresponsive to O₂-O₃ therapy was satisfactory. Among other methods used to treat lumbar disc herniation, DiscoGel® chemonucleolysis can be deemed an intermediate procedure bridging conservative medical treatments and surgery.

Treatment of intracranial aneurysms using flow-diverting silk stents (BALT): a single centre experience

The Silk stent (Balt, Montmorency, France) is a retractable device designed to achieve curative reconstruction of the parent artery associated with an intracranial aneurysm. We present our initial experience with the Silk flow-diverting stent in the management and follow-up of 25 patients presenting with intracranial aneurysms.Twenty-five patients (age range, 34-81 years; 24 female) were treated with the Silk flow-diverting device. Aneurysms ranged in size from small (5), large (10) and giant (10) and included wide-necked aneurysms, multiple, nonsaccular, and recurrent intracranial aneurysms. Nine aneurysms were treated for headache, 14 for mass effect. None presented with haemorrhage. All patients were pretreated with dual antiplatelet medications for at least 72 hours before surgery and continued taking both agents for at least three months after treatment. A total of 25 Silk stents were used. Control MR angiography and/or CT angiography was typically performed prior to discharge and at one, three, six and 12 months post treatment. A follow-up digital subtraction angiogram was performed between six and 19 months post treatment.Complete angiographic occlusion or subtotal occlusion was achieved in 15 patients in a time frame from three days to 12 months. Three deaths and one major complication were encountered during the study period. Two patients, all with cavernous giant aneurysms, experienced transient exacerbations of preexisting cranial neuropathies and headache after the Silk treatment. Both were treated with corticosteroids, and symptoms resolved completely within a month.In our experience the Silk stent has proven to be a valuable tool in the endovascular treatment of intracranial giant partially thrombosed aneurysms and aneurysms of the internal carotid artery cavernous segment presenting with mass effect. The time of complete occlusion of the aneurysms and the risk of the bleeding is currently not predictable.

Interaction map of the Trypanosoma cruzi ribosomal P protein complex (stalk) and the elongation factor 2

The large subunit of the eukaryotic ribosome possesses a long and protruding stalk formed by the ribosomal P proteins. This structure is involved in the translation step of protein synthesis through interaction with the elongation factor 2 (EF-2). The Trypanosoma cruzi stalk complex is composed of four proteins of about 11 kDa, TcP1α, TcP1β, TcP2α, TcP2β and a fifth TcP0 of about 34 kDa. In a previous work, a yeast two-hybrid (Y2H) protein-protein interaction map of T. cruzi ribosomal P proteins was generated. In order to gain new insight into the assembly of the stalk, a complete interaction map was generated by surface plasmon resonance (SPR) and the kinetics of each interaction was calculated. All previously detected interactions were confirmed and new interacting pairs were found, such as TcP1β-TcP2α and TcP1β-TcP2β. Moreover P2 but not P1 proteins were able to homo-oligomerize. In addition, the region comprising amino acids 210-270 on TcP0 was identified as the region interacting with P1/P2 proteins, using Y2H and SPR. The interaction domains on TcP2β were also mapped by SPR identifying two distinct regions. The assembly order of the pentameric complex was assessed by SPR showing the existence of a hierarchy in the association of the different P proteins forming the stalk. Finally, the TcEF-2 gene was identified, cloned, expressed and refolded. Using SPR analysis we showed that TcEF-2 bound with similar affinity to the four P1/P2 ribosomal P proteins of T. cruzi but with reduced affinity to TcP0.

The use of flow-diverting stents in the treatment of giant cerebral aneurysms: preliminary results

The treatment of giant cerebral aneurysms has always been a challenge for neurosurgeons and neuroradiologists. Flow-diverting stents (Silk; Pipeline Embolization Device) are new endovascular devices introduced for the treatment of intracranial aneurysms without release of intrasaccular coils. They are tubular bimetallic endoluminal devices with low porosity. We have employed these stents in the Neuroradiology Unit of Bellaria Hospital (Bologna, Italy) since the end of 2008, treating nine patients with giant carotid cerebral aneurysms using nine Silk stents as soon as the device obtained the CE mark. All patients were pretreated with dual antiplatelet medications before surgery. The Silk stents were deployed through a 4F Balt introducer, which ensured an uneventful and very quick procedure. Control CT angiography or MR angiography was typically performed at discharge and one, three, six and 12 months after treatment. Post-treatment results were: four complete occlusions, three near complete occlusions (residual neck flow) with reduced volume of the aneurysm and two more than 50% reduction of intra-aneurysmal flow. A fatal hemorrhagic complication occurred in one patient, probably due to the antiplatelet treatment. The Silk stent seems a very interesting curative device to treat giant aneurysms with preservation of the parent artery and small adjacent branches. Technical improvements will certainly reduce the thrombogenic effect with the related risks.

A Little Talk on Adamkiewicz's Artery. Some Practical Considerations on the Pre-Operative Identification of this Artery Starting from a Single Team Experience in Pre-Surgical Selective Embolization of Vascularized Spinal Lesions

The major radicular artery eponymically named "Adamkiewicz's artery" (AKA) is an important vessel supplying the spinal cord, especially the lumbar enlargement. This report emphasizes the importance of anatomical knowledge of this artery and highlights the concept of the potential risk of neurological complications during different procedures: spine orthopedic/neurosurgery, aortic repair (vascular surgery) and endovascular selective embolizations performed by interventional neuro/radiologists. Anatomical considerations are made on the spinal cord arterial circulation with a special focus on the AKA. Our review of the literature considered this anatomical element essential to compare the potential risk of spinal cord ischemic damage during orthopedic/neurosurgical spine procedures, aortic vascular surgery repair procedures and endovascular selective arterial embolizations. Evaluation of the endovascular selective arterial spine embolization risk was based on our series of 410 embolization procedures. Spinal cord infarction and transient or permanent paraplegia may result from inadvertent interruption of the AKA. The presence of intersegmental collaterals may decrease the risk of spinal cord ischemia: this is an important element to bear in mind that may help in spine surgery or aortic repair procedures performed by vascular surgeons. Nevertheless, during aortic repair (open surgery or stent-graft procedures) interruption of bilateral segmental arteries at multiple consecutive levels including that of the AKA may occur thereby increasing the ischemic spinal cord risk, annulling the benefit of intersegmental collaterals. Accidental embolizations of the AKA during endovascular spine procedures (i.e. selective arterial embolizations) performed by interventional neuro/radiologists will cause an almost certain spinal cord infarction due to the consequent embolizations of the anterior spinal artery (ASA).

3T MRI in the Evaluation of Brain Aneurysms Treated with Flow-Diverting Stents: Preliminary Experience

Deployment of stents across the neck of intracranial aneurysms to isolate the lesion from the circulation is a recently introduced endovascular treatment. These devices are known as flow-diverting stents because the stent mesh design drastically slows the blood flow within the aneurysm sac, thereby stimulating thrombus formation. Treated aneurysms require close follow-up monitoring using an effective minimally invasive method. We devised a dedicated follow-up protocol using a high field strength magnetic resonance system (MR) with gadolinium administration to monitor 11 patients treated by insertion of flow-diverting stents. Findings were compared with the results of a reference imaging procedure (CT angiography). MR accurately demonstrated patency of the stent lumen and monitored the evolution of the aneurysmal sac in all patients. Gadolinium administration proved essential in two patients to depict the complete exclusion of the flow within the aneurysmal sac.

Treatment of carotid siphon aneurysms with a microcell stent. A case report

SUMMARY

The treatment of giant, large, multiple or wide-necked carotid siphon aneurysms has always represented a challenge for neurosurgeons and neuroradiologists. Very recently the use of stents with tiny holes has been proposed by two companies: Balt Silk Stent in Europe and Pipeline in America. We have used the Silk stent on a few patients and describe our first case who now has an eleven month follow-up. The carotid siphon presented three converging aneurysms sharing a very large common neck. The Silk stent (Balt Extrusion, Montmorency, France) was deployed through a 4F Balt introducer. The procedure was uneventful and very quick. As soon as the stent was positioned contrast medium stagnation was displayed within the aneurysm. The patient's post-operative course was normal and she was discharged three days later in good health.

Carotid Stenting without Angioplasty and without Protection: The Advantages of a Less Invasive Procedure

SUMMARY

Endovascular stenting is a consolidated alternative to thrombendarterectomy in the treatment of extracranial carotid artery atheromasic stenosis. The most common complication of stenting is a distal embolism causing clinically silent orsymptomatic cerebral ischaemia. To prevent this complication distal embolism protection devices are often used but their effectiveness remains unsettled. In addition, there is some evidence that distal embolism may actually be triggered by the protection systems due to clot formationat their distal surface or in the intimal lesions these systems cause. Another rarer complicationis hyperperfusion syndrome arising during both stenting and thrombendarterectomy but more common in endovascular procedures. To avoid these complications the Neuroradiology Service at Bellaria Hospital (Bologna Local Health Trust) has devised a mini-invasive carotid stenting technique that does not require either distal embolism protection or angioplasty. The technique uses only the radial force exerted by the self-expanding stent to widen the atherosclerotic stenosis slowly and gradually. The goal of treatment has also changed from a prompt restoration of the atheromasic vessel's original calibre to slow transformation of the hemodynamic significance of the stenosis. The technique's success lies mainly in selecting the stenosis to treat using CT angiography to analyse plaque morphology and structure.We used the technique to treat 83 stenotic lesions in 75 patients. The study aims to describe and discussour experience.

Simplified superovulatory treatments in Corriedale ewes

Two experiments were designed to evaluate the possibility of simplifying superovulatory treatments in Corriedale ewes with use of ovine FSH (oFSH). Ewes received intravaginal progestogen sponges for 14 days. In Experiment 1, several simplified schedules were tested. Ewes were treated with 176 NIH-FSH-S1 units' oFSH given as a single injection in saline, along with 500 IU eCG 48 h before sponge removal (Group A1), in four equal doses (B1), or given as a single injection in a polyvinylpyrrolidone vehicle (C1) 24 h before sponge removal. In Experiment 2, the simplified protocol that exhibited the most desirable results in Experiment 1 (A2) was compared with the same protocol, but using less oFSH (132 units) (B2) and with the most conventional protocol (176 units of oFSH in eight decreasing doses; C2). Estrus was detected and ewes were naturally mated. The ovarian response and embryo production were assessed on Day 6 after estrus. LH was measured at 6h intervals from pessary withdrawal. The onset of estrus and the pre-ovulatory LH surge were advanced (P<0.05) in ewes treated with FSH and eCG. In Experiment 1, protocol A1 produced a greater percentage of superovulated ewes compared to C1 (100.0 compared with 58.3%; P<0.05), increased ovulation rate (13.8 corpora lutea compared with 6.2 and 4.7 for B1 and C1, respectively; P<0.05), and tended to increase the number of transferable embryos compared to B1 (P=0.08). In Experiment 2, percentages of superovulated ewes and ovulation rates were similar among groups; however, Group A2 tended to have more large follicles (P=0.07) than C2. The number of transferable embryos was similar among the three treatments. In conclusion, the reduced-dose oFSH given once along with eCG is the most appropriate superovulatory treatment because it combines simplicity and a lesser dose of gonadotropin, which also implies a reduction in cost, without reducing embryo production.

Use of Glubran 2 acrylic glue in interventional neuroradiology

INTRODUCTION

Glubran 2 is a cyanoacrylate-based synthetic glue modified by the addition of a monomer synthesized by the manufacturer. With this material it is possible to obtain the stability of endovascular embolization that is needed to treat tumours and vascular disease.

MATERIAL AND METHODS

We report our 3-year experience of the use of Glubran for treating extracerebral tumours, spinal tumours, spinal arteriovenous malformations, and brain and spine dural fistulae. Glubran 2 was diluted with Lipiodol and injected in a continuous column with the flow rate monitored by seriography. The injection was stopped when retrograde flow was displayed in the afferent vessel.

RESULTS

There were no periprocedural or subsequent clinical complications and the glue resulted in successful selective permanent occlusion with intralesional penetration similar to the angiographic features of microcatheterization.

CONCLUSIONS

The embolization procedure was technically straightforward and relatively safe. However, Glubran 2 can be difficult to use and the procedure does carry major risks for patients. Glue injection requires in-depth study of the lesion, its circulation and the collateral circulation to avoid severe complications due to inappropriate use.

Intracranial stenting in the treatment of wide-necked aneurysms

SUMMARY

We positioned the following self-expanding stents certified for intracranial application: 16 Neuroform (Boston Scientific), three INX (Medtronic), one Leo (Balt). 6F calibre femoral introducers and guiding catheters were used for stent placement changing to 5F calibre introducers and guiding catheters (Envoy, Cordis) for the Neuroform 2 and 3 stents. All procedures were carried out under general anaesthesia and heparinization. Our pharmacological protocol consisted of adjunctive treatment with anti-aggregants during the interventional procedure and for the following six months, without premedication. From November 2000 to August 2006 we treated 28 patients (27 F/1M) with giant wide-necked aneurysms and one dissecting basilar artery aneurysm requiring the placement of 29 stents. We successfully positioned 20 stents: 11 stents combined with coils (8 immediate; 3 late) with complete exclusion of the aneurysm from the circulation in seven cases and subtotal exclusion in four; nine stents not followed by embolization with complete exclusion of the aneurysm from the circulation in six cases and subtotal exclusion in three. Stenting was not possible in nine cases due to extreme vessel tortuosity and the poor flexibility of release systems for the first stents. No late stent occlusion or subarachnoid haemorrhage were encountered after treatment.