Sunflower seed-derived bioactive peptides show antioxidant and anti-inflammatory activity: From in silico simulation to the animal model

The evolving field of food technology is increasingly dedicated to developing functional foods. This study explored bioactive peptides from sunflower protein isolate (SPI), obtained from defatted flour, a by-product of the oil processing industry. SPI underwent simulated gastrointestinal digestion and the obtained peptide-enriched fraction (PEF) showed antioxidant properties in vivo, in zebrafish. Among the peptides present in PEF identified by mass spectrometry analysis, we selected those with antioxidant properties by in silico evaluation, considering their capability to interact with Keap1, key protein in the regulation of antioxidant response. The selected peptides were synthesized and evaluated in a cellular model. As a result, DVAMPVPK, VETGVIKPG, TTHTNPPPEAE, LTHPQHQQQGPSTG and PADVTPEEKPEV activated Keap1/Nrf2 pathway leading to Antioxidant Response Element-regulated enzymes upregulation. Since the crosstalk between Nrf2 and NF-κB is well known, the potential anti-inflammatory activity of the peptides was assessed and principally PADVTPEEKPEV showed good features both as antioxidant and anti-inflammatory molecule.

Mitochondrial Ca2+ signaling is a hallmark of specific adipose tissue-cancer crosstalk

Obesity is associated with increased risk and worse prognosis of many tumours including those of the breast and of the esophagus. Adipokines released from the peritumoural adipose tissue promote the metastatic potential of cancer cells, suggesting the existence of a crosstalk between the adipose tissue and the surrounding tumour. Mitochondrial Ca2+ signaling contributes to the progression of carcinoma of different origins. However, whether adipocyte-derived factors modulate mitochondrial Ca2+ signaling in tumours is unknown. Here, we show that conditioned media derived from adipose tissue cultures (ADCM) enriched in precursor cells impinge on mitochondrial Ca2+ homeostasis of target cells. Moreover, in modulating mitochondrial Ca2+ responses, a univocal crosstalk exists between visceral adipose tissue-derived preadipocytes and esophageal cancer cells, and between subcutaneous adipose tissue-derived preadipocytes and triple-negative breast cancer cells. An unbiased metabolomic analysis of ADCM identified creatine and creatinine for their ability to modulate mitochondrial Ca2+ uptake, migration and proliferation of esophageal and breast tumour cells, respectively.

The mitochondrial ATP-dependent potassium channel (mitoKATP) controls skeletal muscle structure and function

MitoKATP is a channel of the inner mitochondrial membrane that controls mitochondrial K+ influx according to ATP availability. Recently, the genes encoding the pore-forming (MITOK) and the regulatory ATP-sensitive (MITOSUR) subunits of mitoKATP were identified, allowing the genetic manipulation of the channel. Here, we analyzed the role of mitoKATP in determining skeletal muscle structure and activity. Mitok-/- muscles were characterized by mitochondrial cristae remodeling and defective oxidative metabolism, with consequent impairment of exercise performance and altered response to damaging muscle contractions. On the other hand, constitutive mitochondrial K+ influx by MITOK overexpression in the skeletal muscle triggered overt mitochondrial dysfunction and energy default, increased protein polyubiquitination, aberrant autophagy flux, and induction of a stress response program. MITOK overexpressing muscles were therefore severely atrophic. Thus, the proper modulation of mitoKATP activity is required for the maintenance of skeletal muscle homeostasis and function.

The potential of cross-linking mass spectrometry in the development of protein-protein interaction modulators

Cross-linking mass spectrometry (XL-MS) can provide a wealth of information on endogenous protein-protein interaction (PPI) networks and protein binding interfaces. These features make XL-MS an attractive tool to support the development of PPI-targeting drugs. Though not yet widely used, applications of XL-MS to drug characterization are beginning to emerge. Here, we compare XL-MS to established structural proteomics methods in drug research, discuss the current state and remaining challenges of XL-MS technology, and provide a perspective on the future role XL-MS can play in drug development, with a particular emphasis on PPI modulators.

Metabolite interactions in the bacterial Calvin cycle and implications for flux regulation

Metabolite-level regulation of enzyme activity is important for microbes to cope with environmental shifts. Knowledge of such regulations can also guide strain engineering for biotechnology. Here we apply limited proteolysis-small molecule mapping (LiP-SMap) to identify and compare metabolite-protein interactions in the proteomes of two cyanobacteria and two lithoautotrophic bacteria that fix CO2 using the Calvin cycle. Clustering analysis of the hundreds of detected interactions shows that some metabolites interact in a species-specific manner. We estimate that approximately 35% of interacting metabolites affect enzyme activity in vitro, and the effect is often minor. Using LiP-SMap data as a guide, we find that the Calvin cycle intermediate glyceraldehyde-3-phosphate enhances activity of fructose-1,6/sedoheptulose-1,7-bisphosphatase (F/SBPase) from Synechocystis sp. PCC 6803 and Cupriavidus necator in reducing conditions, suggesting a convergent feed-forward activation of the cycle. In oxidizing conditions, glyceraldehyde-3-phosphate inhibits Synechocystis F/SBPase by promoting enzyme aggregation. In contrast, the glycolytic intermediate glucose-6-phosphate activates F/SBPase from Cupriavidus necator but not F/SBPase from Synechocystis. Thus, metabolite-level regulation of the Calvin cycle is more prevalent than previously appreciated.

Proteome-wide structural changes measured with limited proteolysis-mass spectrometry: an advanced protocol for high-throughput applications

Proteins regulate biological processes by changing their structure or abundance to accomplish a specific function. In response to a perturbation, protein structure may be altered by various molecular events, such as post-translational modifications, protein-protein interactions, aggregation, allostery or binding to other molecules. The ability to probe these structural changes in thousands of proteins simultaneously in cells or tissues can provide valuable information about the functional state of biological processes and pathways. Here, we present an updated protocol for LiP-MS, a proteomics technique combining limited proteolysis with mass spectrometry, to detect protein structural alterations in complex backgrounds and on a proteome-wide scale. In LiP-MS, proteins undergo a brief proteolysis in native conditions followed by complete digestion in denaturing conditions, to generate structurally informative proteolytic fragments that are analyzed by mass spectrometry. We describe advances in the throughput and robustness of the LiP-MS workflow and implementation of data-independent acquisition-based mass spectrometry, which together achieve high reproducibility and sensitivity, even on large sample sizes. We introduce MSstatsLiP, an R package dedicated to the analysis of LiP-MS data for the identification of structurally altered peptides and differentially abundant proteins. The experimental procedures take 3 d, mass spectrometric measurement time and data processing depend on sample number and statistical analysis typically requires ~1 d. These improvements expand the adaptability of LiP-MS and enable wide use in functional proteomics and translational applications.

Differential regulation of mRNA stability modulates transcriptional memory and facilitates environmental adaptation

Transcriptional memory, by which cells respond faster to repeated stimuli, is key for cellular adaptation and organism survival. Chromatin organization has been shown to play a role in the faster response of primed cells. However, the contribution of post-transcriptional regulation is not yet explored. Here we perform a genome-wide screen to identify novel factors modulating transcriptional memory in S. cerevisiae in response to galactose. We find that depletion of the nuclear RNA exosome increases GAL1 expression in primed cells. Our work shows that gene-specific differences in intrinsic nuclear surveillance factor association can enhance both gene induction and repression in primed cells. Finally, we show that primed cells present altered levels of RNA degradation machinery and that both nuclear and cytoplasmic mRNA decay modulate transcriptional memory. Our results demonstrate that mRNA post-transcriptional regulation, and not only transcription regulation, should be considered when investigating gene expression memory.

Abstract 21: LiP-MS, a machine learning-based chemoproteomic approach to identify drug targets in complex proteomes

Background

Target identification is a critical step in elucidating the mechanism of action (MoA) for bioactive compounds. For target-based and phenotypic drug discovery pipelines, extensive potential target knowledge for a lead compound provides essential insights that enable potency and selectivity optimization. The tedious process of target deconvolution for a compound often necessitates a plethora of biochemical and biophysical techniques. To expand the toolbox of unbiased target ID approaches, we developed a novel workflow combining limited proteolysis with quantitative mass spectrometry (LiP-MS) that exploits the drug binding phenomena of protein structural alterations and steric hindrance. Advantageously, LiP-MS's unique peptide-centric focus exploits signature peptide detection to discern ligand binding. Additionally, the LiP-MS workflow enables binding affinity estimation (EC50) and binding site prediction. Here we demonstrate the performance of LiP-MS using two well-characterized kinase inhibitors (KIs), an AstraZeneca CDK9 inhibitor (AZ) and Selumetinib (SE).

Methods

Mechanically sheared HeLa or U2OS cell lysate was incubated with compound at multiple concentrations. Next, a limited proteolytic digest was performed using proteinase K. After quenching this digestion, lysate was trypsin digested to peptides for mass spectrometry analysis. The resulting peptides were analyzed quantitatively using data-independent acquisition (DIA)-MS.

Results

Herein, we use LiP-MS to unbiasedly identify unique peptides generated by the binding of two distinct classes of kinase inhibitors in human cell lysate. For the ATP-competitive inhibitor AZ, LiP-Quant shows a strong enrichment for CDKs in the target space defined by LiP score, including CDK1, 2, 4, 6, 9 and 11A. In addition, our data indicates that this KI targets members of the CDKs with different selectivity, with CDK9 displaying the highest compound affinity (nM range). For Selumetinib, a non-competitive allosteric inhibitor, LiP-MS clearly identified the direct targets MEK1/2 as the main hits by LiP score. Both cases represent a highly specific enrichment given that we quantified > 120,000 peptides in each of the experiments. These findings confirm our approach's ability to identify genuine drug targets regardless of drug MoA in a complex biological matrix. Importantly, in both KI target ID studies, identified LiP peptides could be successfully deployed to map compound binding site, demonstrating the potential of LiP-MS to pinpoint regions involved in drug-protein interactions.

Conclusions

Collectively, this data demonstrates that LiP-MS can be used to effectively identify protein drug targets and characterize the binding properties in complex proteomes independent of the compound's MoA and without compound modification or labeling. These capabilities make LiP-MS a powerful addition to the target ID toolbox.

Citation Format: Nigel Beaton, Yuehan Feng, Roland Bruderer, Adam Hendricks, Ghaith Hamza, Eric Miele, Rick Davies, Kristina Beeler, Ilaria Piazza, Paola Picotti, Paola Castaldi, Lukas Reiter. LiP-MS, a machine learning-based chemoproteomic approach to identify drug targets in complex proteomes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 21.

Effect of Tocilizumab vs Standard Care on Clinical Worsening in Patients Hospitalized With COVID-19 Pneumonia: A Randomized Clinical Trial

IMPORTANCE

The coronavirus disease 2019 (COVID-19) pandemic is threatening billions of people worldwide. Tocilizumab has shown promising results in retrospective studies in patients with COVID-19 pneumonia with a good safety profile.

OBJECTIVE

To evaluate the effect of early tocilizumab administration vs standard therapy in preventing clinical worsening in patients hospitalized with COVID-19 pneumonia.

DESIGN, SETTING, AND PARTICIPANTS

Prospective, open-label, randomized clinical trial that randomized patients hospitalized between March 31 and June 11, 2020, with COVID-19 pneumonia to receive tocilizumab or standard of care in 24 hospitals in Italy. Cases of COVID-19 were confirmed by polymerase chain reaction method with nasopharyngeal swab. Eligibility criteria included COVID-19 pneumonia documented by radiologic imaging, partial pressure of arterial oxygen to fraction of inspired oxygen (Pao2/Fio2) ratio between 200 and 300 mm Hg, and an inflammatory phenotype defined by fever and elevated C-reactive protein.

INTERVENTIONS

Patients in the experimental arm received intravenous tocilizumab within 8 hours from randomization (8 mg/kg up to a maximum of 800 mg), followed by a second dose after 12 hours. Patients in the control arm received supportive care following the protocols of each clinical center until clinical worsening and then could receive tocilizumab as a rescue therapy.

MAIN OUTCOME AND MEASURES

The primary composite outcome was defined as entry into the intensive care unit with invasive mechanical ventilation, death from all causes, or clinical aggravation documented by the finding of a Pao2/Fio2 ratio less than 150 mm Hg, whichever came first.

RESULTS

A total of 126 patients were randomized (60 to the tocilizumab group; 66 to the control group). The median (interquartile range) age was 60.0 (53.0-72.0) years, and the majority of patients were male (77 of 126, 61.1%). Three patients withdrew from the study, leaving 123 patients available for the intention-to-treat analyses. Seventeen patients of 60 (28.3%) in the tocilizumab arm and 17 of 63 (27.0%) in the standard care group showed clinical worsening within 14 days since randomization (rate ratio, 1.05; 95% CI, 0.59-1.86). Two patients in the experimental group and 1 in the control group died before 30 days from randomization, and 6 and 5 patients were intubated in the 2 groups, respectively. The trial was prematurely interrupted after an interim analysis for futility.

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial of hospitalized adult patients with COVID-19 pneumonia and Pao2/Fio2 ratio between 200 and 300 mm Hg who received tocilizumab, no benefit on disease progression was observed compared with standard care. Further blinded, placebo-controlled randomized clinical trials are needed to confirm the results and to evaluate possible applications of tocilizumab in different stages of the disease.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04346355; EudraCT Identifier: 2020-001386-37.

Abstract 6404: LiP-Quant, an automated chemoproteomic approach to identify drug targets in complex proteomes

Background

Target identification is a critical step in elucidating the mechanism of action (MoA) for bioactive compounds. For phenotypic drug discovery pipelines, current unbiased, label-free chemoproteomics-based methods rely predominantly on the modulation of target thermal stability upon drug binding. We developed an automated drug target deconvolution workflow combining limited proteolysis with mass spectrometry (LiP-Quant) that exploits protein structural alterations, as well as steric effects driven by drug binding. A major advantage of LiP-Quant is its unique focus on the detection of signature peptides that discern ligand binding, peptides that are generated by a limited digestion and identified by proteomic analysis. Here we demonstrate the performance of LiP-Quant using two well-characterized kinase inhibitors (KIs), Selumetinib (SE) and Staurosporine (ST), as well as two natural product-derived phosphatase inhibitors (PIs) Calyculin A and Fostriecin in human cell lysate. Furthermore, LiP-Quant can be deployed to estimate in-lysate EC50 value of compound binding.

Methods

Mechanically sheared HeLa cell lysate was incubated with compound at multiple concentrations. Next, a limited digest was performed using proteinase K. Finally, the limited digests were processed to peptides with trypsin for mass spectrometry analysis. A project-specific spectral library was generated using data-dependent acquisition (DDA) mass spectrometry and for quantitative analysis data-independent acquisition (DIA) data were recorded and analyzed using Spectronaut Pulsar X.

Results

Herein, we demonstrate the ability of our LiP-Quant approach to identify unique peptides generated by the binding of either a highly specific (selumetinib) or broad specificity (staurosporine) KI in human cell line lysate. While > 20 kinases met the qualifying LiP-score cutoff for staurosporine, the direct targets MEK1 and MEK2 were clearly identified as main hits in the unbiased ranking by LiP scores. Both cases represent a highly specific enrichment given that we quantified > 100,000 peptides in each of the experiments. These findings confirm our approach's ability to identify genuine drug targets regardless of drug specificity in a complex biological matrix. To characterize the specificity of LiP-Quant, we treated lysate with two separate protein PIs. According to literature calyculin A targets protein phosphatase 1 and 2 (PP1A and PP2A) and fostriecin also targets PP2A, in addition to protein phosphatase 4 (PP4C) but does not bind PP1A. Robust phosphatase identification was achieved for both calyculin A and fostriecin treatment. Importantly, with LiP-Quant, we could recapitulate the known relative affinities of the PIs towards their respective targets.

Conclusions

Collectively, this data demonstrate that LiP-Quant can be used to effectively identify protein drug targets and characterize the binding properties in complex proteomes, without compound modification or labeling, and regardless of the specificity of the compound. These capabilities make LiP-Quant a powerful target deconvolution and identification strategy.

Citation Format: Yuehan Feng, Nigel Beaton, Roland Bruderer, Ilaria Piazza, Paola Picotti, Lukas Reiter. LiP-Quant, an automated chemoproteomic approach to identify drug targets in complex proteomes [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6404.

Epidemiologic and clinical profiles of bacterial myocarditis. Report of two cases and data from a pooled analysis

We aimed to characterize the epidemiology, diagnostic peculiarities and outcome determinants of bacterial myocarditis.

Two cases from our institution and literature reports were collected ending up with a total of 66 cases. In 37 (56%) patients, the diagnosis was confirmed by magnetic resonance and histopathological criteria. The other patients were classified as having possible myocarditis.

Only occurrence of rhythm disturbances was associated with the specific diagnosis of myocarditis (p = 0.04). Thirty-two (48%) patients presented with severe sepsis that was associated with a worse prognosis. At multivariate analysis, left ventricular ejection fraction (LVEF) at admission and heart rhythm disturbances were associated with incomplete recovery (odds ratio (OR) 1.1, 95% (CI) 1.03–1.2, p = 0.004 and OR 6.6, 95% CI 1.35–32.5, p = 0.02, respectively).

In summary, bacterial myocarditis is uncommon. Most commonly, it is secondary to septic dissemination of bacteria or to transient secondary myocardial toxicity.

Comparison of Early vs. Delayed Anakinra Treatment in Patients With Adult Onset Still's Disease and Effect on Clinical and Laboratory Outcomes

Background: Aim of this study was to search for any difference in the outcome of patients with adult onset Still's disease (AOSD) treated with anakinra (ANK) in relation with the interval between disease onset and the start of anti-interleukin(IL)-1 treatment and according with the different lines of ANK treatment.

Patients and Methods: One hundred and forty-one AOSD patients treated with ANK have been retrospectively assessed. Statistically significant differences (p < 0.05) were analyzed in the frequency of ANK effectiveness, primary or secondary inefficacy to ANK and rate of resolution of clinical and laboratory AOSD manifestations after 3, 6, and 12 months since ANK treatment according with different lines of treatment and different times between AOSD onset and start of ANK.

Results: No significant differences were identified in the ANK effectiveness and frequency of primary or secondary inefficacy for patients starting ANK within 6 months (p = 0.19, p = 0.14, and p = 0.81, respectively) or 12 months (p = 0.37, p = 0.23, and p = 0.81, respectively) since AOSD onset compared with patients starting ANK thereafter; no significant differences were identified in ANK effectiveness and primary or secondary inefficacy according with different lines of ANK treatment (p = 0.06, p = 0.19, and p = 0.13, respectively). Patients starting ANK within 6 and 12 months since AOSD onset showed a significantly quicker decrease of erythrocyte sedimentation rate and C-reactive protein than observed among patients undergoing ANK treatment after 6 and 12 months. The number of swollen joints at the 3 month follow-up visit was significantly lower among patients undergoing ANK within 6 months since AOSD onset (p = 0.01), while no significance was identified at the 6 and 12 month assessments (p = 0.23 and p = 0.45, respectively). At the 3 and 6 month visits, the number of swollen joints was significantly higher among patients previously treated with conventional and biological disease modifying anti-rheumatic drugs (DMARDs) compared with those formerly treated only with conventional DMARDs (p < 0.017).

Conclusions: Clinical and therapeutic outcomes are substantially independent of how early ANK treatment is started in AOSD patients. However, a faster ANK effectiveness in controlling systemic inflammation and resolving articular manifestations may be observed in patients benefiting from IL-1 inhibition as soon as after disease onset.

Abstract C015: Limited proteolysis coupled to mass spectrometry (LiP-Quant), a novel drug target deconvolution strategy

Background: High attrition rates in target-centric drug development approaches, as well as a limited number of targets, have shifted the focus of drug development back towards phenotypic screening. In parallel, novel proteomics-based target deconvolution approaches to drug target identification have gained popularity. Limited proteolysis coupled with mass spectrometry (LiP-MS) is a new target deconvolution technique that exploits protein structural alterations, as well as steric effects driven by drug binding. A major advantage of LiP-MS is its unique focus on detection of signature peptides that report on ligand binding, which are generated by a limited digestion and identified by proteomic analysis. Here we demonstrate the performance of LiP-MS using two well-characterized kinase inhibitors, Selumetinib (SE) and Staurosporine (ST), as well as two natural product-derived phosphatase inhibitors Calyculin A and Fostriecin in HeLa cell lysate. Additionally, we introduce a LiP workflow that can be used to dissect protein-drug interactions in a more nuanced manner. Results Herein, we demonstrate the ability of our LiP-MS approach to identify unique peptides generated by the binding of either a highly-specific (SE) or broad specificity (ST) kinase inhibitor. Taking the top 200 identified target candidate peptides ranked by LiP score from the broad inhibitor (staurosporine), GO enrichment analysis confirmed a highly significant 3-fold enrichment for kinase targets (p &lt; 2E-5). For the more challenging selumetinib experiment, the direct targets MEK1 and MEK2 were clearly identified as main hits with 5 peptides in the top 16 (sorted by LiP score). This represents a highly specific enrichment given that we quantified &gt; 100,000 peptide precursors in this experiment. These findings confirm our approach’s ability to identify genuine drug targets regardless of drug specificity. To characterize the specificity of LiP-MS, we treated lysate with two separate protein phosphatase inhibitors. According to literature calyculin A targets protein phosphatase 1 and 2 (PP1A and PP2A) and fostriecin also targets PP2A, in addition to protein phosphatase 4 (PP4C) but does not bind PP1A. We identified both targets of calyculin A, with 14 of the top 15 peptides by LiP score being from either PP2A or PP1A. Robust phosphatase identification (three main targets PP2A, PP4C and PP6C) was also observed with fostriecin treatment with a different profile from calyculin A. In line with literature, the hits of fostriecin did not include PP1A, despite the high homology of the protein phosphatase family. Finally, taking advantage of the peptide resolution of LiP-MS, we employed this workflow to investigate the Ca2+-induced conformational switch in the recombinant protein calmodulin by monitoring structure-specific peptides which cover its entire amino acid sequence. Conclusions Collectively, this data demonstrates that LiP-MS can be used to effectively identify protein drug targets and characterize the binding properties, regardless of the specificity of the compound. These capabilities make LiP-MS a powerful target deconvolution and identification strategy. In addition, we envision the development of LiP-MS for recombinant proteins as a high-throughput strategy for binding site characterization of protein-small molecule and protein-protein interactions.

Citation Format: Yuehan Feng, Nigel Beaton, Roland Bruderer, Ilaria Piazza, Paola Picotti, Lukas Reiter. Limited proteolysis coupled to mass spectrometry (LiP-Quant), a novel drug target deconvolution strategy [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr C015. doi:10.1158/1535-7163.TARG-19-C015

Chromatin-sensitive cryptic promoters putatively drive expression of alternative protein isoforms in yeast

Cryptic transcription is widespread and generates a heterogeneous group of RNA molecules of unknown function. To improve our understanding of cryptic transcription, we investigated their transcription start site (TSS) usage, chromatin organization, and posttranscriptional consequences in Saccharomyces cerevisiae We show that TSSs of chromatin-sensitive internal cryptic transcripts retain comparable features of canonical TSSs in terms of DNA sequence, directionality, and chromatin accessibility. We define the 5' and 3' boundaries of cryptic transcripts and show that, contrary to RNA degradation-sensitive ones, they often overlap with the end of the gene, thereby using the canonical polyadenylation site, and associate to polyribosomes. We show that chromatin-sensitive cryptic transcripts can be recognized by ribosomes and may produce truncated polypeptides from downstream, in-frame start codons. Finally, we confirm the presence of the predicted polypeptides by reanalyzing N-terminal proteomic data sets. Our work suggests that a fraction of chromatin-sensitive internal cryptic promoters initiates the transcription of alternative truncated mRNA isoforms. The expression of these chromatin-sensitive isoforms is conserved from yeast to human, expanding the functional consequences of cryptic transcription and proteome complexity.

Anomalous water dynamics in brain: a combined diffusion magnetic resonance imaging and neutron scattering investigation

Water diffusion is an optimal tool for investigating the architecture of brain tissue on which modern medical diagnostic imaging techniques rely. However, intrinsic tissue heterogeneity causes systematic deviations from pure free-water diffusion behaviour. To date, numerous theoretical and empirical approaches have been proposed to explain the non-Gaussian profile of this process. The aim of this work is to shed light on the physics piloting water diffusion in brain tissue at the micrometre-to-atomic scale. Combined diffusion magnetic resonance imaging and first pioneering neutron scattering experiments on bovine brain tissue have been performed in order to probe diffusion distances up to macromolecular separation. The coexistence of free-like and confined water populations in brain tissue extracted from a bovine right hemisphere has been revealed at the micrometre and atomic scale. The results are relevant for improving the modelling of the physics driving intra- and extracellular water diffusion in brain, with evident benefit for the diffusion magnetic resonance imaging technique, nowadays widely used to diagnose, at the micrometre scale, brain diseases such as ischemia and tumours.

Network Rewiring of Homologous Recombination Enzymes during Mitotic Proliferation and Meiosis

Homologous recombination (HR) is essential for high-fidelity DNA repair during mitotic proliferation and meiosis. Yet, context-specific modifications must tailor the recombination machinery to avoid (mitosis) or enforce (meiosis) the formation of reciprocal exchanges-crossovers-between recombining chromosomes. To obtain molecular insight into how crossover control is achieved, we affinity purified 7 DNA-processing enzymes that channel HR intermediates into crossovers or noncrossovers from vegetative cells or cells undergoing meiosis. Using mass spectrometry, we provide a global characterization of their composition and reveal mitosis- and meiosis-specific modules in the interaction networks. Functional analyses of meiosis-specific interactors of MutLγ-Exo1 identified Rtk1, Caf120, and Chd1 as regulators of crossing-over. Chd1, which transiently associates with Exo1 at the prophase-to-metaphase I transition, enables the formation of MutLγ-dependent crossovers through its conserved ability to bind and displace nucleosomes. Thus, rewiring of the HR network, coupled to chromatin remodeling, promotes context-specific control of the recombination outcome.

Abstract 2755: Limited proteolysis coupled to mass spectrometry (LiP-MS), a novel drug target deconvolution strategy

Background High attrition rates in target-centric drug development approaches, as well as a limited number of targets, have shifted the focus of drug development back towards phenotypic screening. In parallel, novel proteomics-based target deconvolution approaches to drug target identification have gained popularity. Limited proteolysis coupled with mass spectrometry (LiP-MS) is a new target deconvolution technique that exploits protein structural alterations driven by drug binding. A major advantage of LiP-MS is its unique focus on detection of peptides that report on ligand binding induced structural changes that are generated by a limited digestion and identified by proteomic analysis. Here we demonstrate the performance of LiP-MS using the protein phosphatase inhibitor Calyculin A, as well as two well known kinase inhibitors, selumetinib (SE) and staurosporine (ST), in HeLa cell lysate.

Materials and Methods Mechanically sheared HeLa cell lysate was incubated with compound at multiple concentrations. Next, a limited digest was performed using proteinase K. Finally, the limited digests were processed to peptides with trypsin for mass spectrometry analysis. A project-specific spectral library was generated using data-dependent acquisition (DDA) mass spectrometry and for quantitative analysis data-independent acquisition (DIA) data were recorded and analyzed using Spectronaut Pulsar X.

Results LiP-MS identifies several peptides for the phosphatase inhibitor Calyculin A, with IC50 values of 52 nM and 17 nM for PP1A and PP2A respectively. Additionally, a previously unknown target PP1B was also identified among the same family, although with a higher IC50 (74 nM). Through structural inspection of ligand-sensitive peptides we were able to map the drug’s binding site within the phosphatases and predict distal conformational changes, demonstrating that LiP-MS can be used to provide structural insights to ligand-protein binding. Similar dose response relationships were observed for both specific (SE) and broad (ST) kinase inhibitors. Amongst the top 200 identified target candidate peptides ranked by LiP score, GO enrichment analysis confirmed a highly significant 3-fold enrichment for kinase targets (p &lt; 0.00002) in ST-treated lysate, while no such enrichment was observed for SE. However, in SE-treated lysate robust identification of multiple MEK1 peptides, one of the compound’s main targets, was observed. In the case of both kinase inhibitors LiP peptides could be successfully mapped to ATP binding sites, confirming the ability of LiP-MS to model drug-bound protein structure.

Conclusions This data demonstrates that LiP-MS can be used to effectively identify protein drug targets and characterize the binding properties, regardless of the specificity of the compound. These capabilities make LiP-MS a powerful target deconvolution and identification strategy.

Citation Format: Nigel Beaton, Roland Bruderer, Kristina Beeler, Nicholas Dupuis, Ilaria Piazza, Paola Picotti, Lukas Reiter. Limited proteolysis coupled to mass spectrometry (LiP-MS), a novel drug target deconvolution strategy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2755.

Long-Term Retention Rate of Anakinra in Adult Onset Still's Disease and Predictive Factors for Treatment Response

Background: Anakinra (ANA) is an effective treatment choice in patients with adult onset Still’s disease (AOSD). Variables affecting treatment survival include loss of efficacy or adverse events, but also the decision to discontinue treatment after long-term clinical remission.

Objectives: Aims of this study were: (i) to assess the drug retention rate (DRR) of ANA during a long-term follow-up looking for any difference related to the line of biologic treatment, the concomitant use of conventional disease modifying anti-rheumatic drugs (cDMARDs) and the different type of AOSD (systemic versus chronic articular); (ii) to identify predictive factors of lack of efficacy, loss of efficacy, and ANA withdrawal owing to long-term remission.

Methods: AOSD patients classified according with Yamaguchi criteria and treated with ANA were retrospectively enrolled in 18 Italian tertiary Centers. Demographic, laboratory, clinical and therapeutic data related to the start of ANA (baseline), the 3-month assessment and the last follow-up visit while on ANA treatment were retrospectively collected and statistically analyzed.

Results: One hundred and forty-one AOSD patients (48 males, 93 females) treated with ANA for a mean period of 35.96 ± 36.05 months were enrolled. The overall DRR of ANA was 44.6 and 30.5% at the 60- and 120-month assessments, respectively, with no significant differences between: (i) biologic naïve patients and those previously treated with other biologics (log-rank p = 0.97); (ii) monotherapy and concomitant use of cDMARDs (log-rank p = 0.45); (iii) systemic and chronic articular types of AOSD (log-rank p = 0.67). No variables collected at baseline could predict primary inefficacy, while the number of swollen joints at baseline was significantly associated with secondary inefficacy (p = 0.01, OR = 1.194, C.I. 1.043–1.367). The typical AOSD skin rash was negatively related with ANA withdrawal owing to long-term remission (p = 0.03, OR = 0.224, C.I. 0.058–0.863).

Conclusion: Long-term DRR of ANA has been found excellent and is not affected by different lines of biologic treatment, concomitant use of cDMARDs, or type of AOSD. The risk of losing ANA efficacy increases along with the number of swollen joints at the start of therapy, while the typical skin rash is a negative predictor of ANA withdrawal related to sustained remission.

High-throughput metabolomic analysis predicts mode of action of uncharacterized antimicrobial compounds

Rapidly spreading antibiotic resistance and the low discovery rate of new antimicrobial compounds demand more effective strategies for early drug discovery. One bottleneck in the drug discovery pipeline is the identification of the modes of action (MoAs) of new compounds. We have developed a rapid systematic metabolome profiling strategy to classify the MoAs of bioactive compounds. The method predicted MoA-specific metabolic responses in the nonpathogenic bacterium Mycobacterium smegmatis after treatment with 62 reference compounds with known MoAs and different metabolic and nonmetabolic targets. We then analyzed a library of 212 new antimycobacterial compounds with unknown MoAs from a drug discovery effort by the pharmaceutical company GlaxoSmithKline (GSK). More than 70% of these new compounds induced metabolic responses in M. smegmatis indicative of known MoAs, seven of which were experimentally validated. Only 8% (16) of the compounds appeared to target unconventional cellular processes, illustrating the difficulty in discovering new antibiotics with different MoAs among compounds used as monotherapies. For six of the GSK compounds with potentially new MoAs, the metabolome profiles suggested their ability to interfere with trehalose and lipid metabolism. This was supported by whole-genome sequencing of spontaneous drug-resistant mutants of the pathogen Mycobacterium tuberculosis and in vitro compound-proteome interaction analysis for one of these compounds. Our compendium of drug-metabolome profiles can be used to rapidly query the MoAs of uncharacterized antimicrobial compounds and should be a useful resource for the drug discovery community.

Response to Interleukin-1 Inhibitors in 140 Italian Patients with Adult-Onset Still's Disease: A Multicentre Retrospective Observational Study

Background: Interleukin (IL)-1 plays a crucial role in the pathogenesis of Adult onset Still's disease (AOSD). Objectives: To evaluate the efficacy and safety of anakinra (ANA) and canakinumab (CAN) in a large group of AOSD patients. Methods: Data on clinical, serological features, and concomitant treatments were retrospectively collected at baseline and after 3, 6, and 12 months from AOSD patients (Yamaguchi criteria) referred by 18 Italian centers. Pouchot's score was used to evaluate disease severity. Results: One hundred forty patients were treated with ANA; 4 were subsequently switched to CAN after ANA failure. The systemic pattern of AOSD was identified in 104 (74.2%) of the ANA-treated and in 3 (75%) of the CAN-treated groups; the chronic-articular type of AOSD was identified in 48 (25.8%) of the ANA-treated and in 1 (25%) of the CAN-treated groups. Methotrexate (MTX) was the most frequent disease modifying anti-rheumatic drug (DMARD) used before beginning ANA or CAN [91/140 (75.8%), 2/4 (50%), respectively]. As a second-line biologic DMARD therapy in 29/140 (20.7%) of the patients, ANA was found effective in improving all clinical and serological manifestations (p < 0.0001), and Pouchot's score was found to be significantly reduced at all time points (p < 0.0001). No differences in treatment response were identified in the ANA-group when the patients were stratified according to age, sex, disease pattern or mono/combination therapy profile. ANA primary and secondary inefficacy at the 12-month time point was 15/140 (10.7%) and 11/140 (7.8%), respectively. Adverse events (AEs) [mainly represented by in situ (28/47, 59.5%) or diffuse (12/47, 25.5%) skin reactions and infections (7/47, 14.8%)] were the main causes for discontinuation. Pouchot's score and clinical and serological features were significantly ameliorated at all time points (p < 0.0001) in the CAN-group, and no AEs were registered during CAN therapy. Treatment was suspended for loss of efficacy only in one case (1/4, 25%). Conclusion: This is the largest retrospective observational study evaluating the efficacy and safety of IL-1 inhibitors in AOSD patients. A good response was noted at 3 months after therapy onset in both the ANA- and CAN-groups. Skin reaction may nevertheless represent a non-negligible AE during ANA treatment.

Prevalence and incidence of osteoporotic fractures in patients on long-term glucocorticoid treatment for rheumatic diseases: the Glucocorticoid Induced OsTeoporosis TOol (GIOTTO) study

Osteoporosis and fractures are common and invalidating consequences of chronic glucorticoid (GC) treatment. Reliable information regarding the epidemiology of GC induced osteoporosis (GIOP) comes exclusively from the placebo group of randomized clinical trials while observational studies are generally lacking data on the real prevalence of vertebral fractures, GC dosage and primary diagnosis. The objective of this study was to evaluate the prevalence and incidence of osteoporotic fractures and to identify their major determinants (primary disease, GC dosage, bone mineral density, risk factors, specific treatment for GIOP) in a large cohort of consecutive patients aged &gt;21 years, on chronic treatment with GC (≥5 mg prednisone - PN - equivalent) and attending rheumatology centers located all over Italy. Glucocorticoid Induced OsTeoporosis TOol (GIOTTO) is a national multicenter cross-sectional and longitudinal observational study. 553 patients suffering from Rheumatoid Arthritis (RA), Polymyalgia Rheumatica (PMR) and Connective Tissue Diseases (CTDs) and in chronic treatment with GCs were enrolled. Osteoporotic BMD values (T score &lt;-2.5) were observed in 28%, 38% and 35% of patients with CTDs, PMR or RA at the lumbar spine, and in 18%, 29% and 26% at the femoral neck, respectively. Before GC treatment, prevalent clinical fractures were reported by 12%, 37% and 17% of patients with CTDs, PMR, or RA, respectively. New clinical fragility fractures during GC treatment were reported by 12%, 10% and 23% of CTDs, PMR and RA patients, respectively. Vertebral fractures were the prevailing type of fragility fracture. More than 30% of patients had recurrence of fracture. An average of 80% of patients were in supplementation with calcium and/or vitamin D during treatment with GCs. Respectively, 64%, 80%, and 72% of the CTDs, PMR and RA patients were on pharmacological treatment for GIOP, almost exclusively with bisphosphonates. The GIOTTO study might provide relevant contributions to clinical practice, in particular by highlighting and quantifying in real life the prevalence of GIOP and relative fractures, the frequency of the main risk factors, and the currently sub-optimal prevention. Moreover, these results emphasize the importance of the underlying rheumatic disease on the risk of GIOP associated fractures.

The initiative on hip fractures of the Veneto Region

OBJECTIVE

to assess the prevalence of the most relevant environmental and individual risk factors in subjects with a recent hip fracture was the aim of this observational study promoted by the Health Authorities of the Regione Veneto (Italy).

METHODS

patients aged > 60 years of both genders with a recent hip fracture not associated with malignancies, were administered questionnaires on dietary habits, sun exposure, disability score. A complete family, pharmacological and pathology history was collected together with previous falls, details of the fracture index, anthropometric data. In a subgroup of patients blood was taken for the measurements of serum 25 hydroxy-vitamin D (25OHD).

RESULTS

the study includes 704 patients (573 women and 131 men). Mean age was 81±8 years (range 60-102). Severe pre-fracture disability was a common feature (58%) associated with multiple co-morbidities (84%), more frequently cardiovascular and neurological diseases, and specific medications. In a large proportion (86%) of the patients environmental or individual risk factors for falling were found. Vitamin D insufficiency was quite common, particularly in the regional Health Districts were strategies for preventing vitamin D deficiency were not implemented. Only a small proportion (17%) of the study population had been evaluate and treated for osteoporosis.

CONCLUSIONS

in senile patients with a recent hip fracture pre-existing disability, multiple co-morbidities, high risk of falling and inadequate intake of calcium and vitamin D was quite common. Community and case-finding interventions are highly warranted.

Alcohol induced burr cell (echinocytic) haemolytic anaemia and haemochromatosis

A 51-year-old man with chronic alcoholic liver disease developed a severe haemolytic anaemia characterized by the presence of circulating burr-shaped cells (echinocytes). Several transfusions of packed red cells were ineffective in raising the haemoglobin concentration, showing that the abnormality was acquired by the transfused cells. Liver biopsies revealed haemochromatosis. Haematological parameters normalized four months after the patient stopped drinking alcohol, but burr cells were still present and erythrocyte life-span was still markedly shortened at one year follow-up. Since serum cholesterol, HDL-cholesterol, and Apo-AI and Apo-B lipoproteins were considerably decreased, the lipid composition of the red cell membrane was studied. Findings showed that echinocytosis occurred with no change in membrane cholesterol content, nor in cholesterol:phospholipid ratio, but with an alteration in the phosphatidylserine and phosphatidylinositol concentrations. While haemochromatosis was most likely the cause of the erythrocyte anomaly, alcohol intake was probably responsible for the acute onset of haemolytic anaemia with effects directly on the erythrocyte membrane as well as mediated by the progressive hepatic injury, with alterations in the plasma and successively in the intramembrane lipid composition.

Humoral response to subcutaneous, oral, and nasal immunotherapy for allergic rhinitis due to Dermatophagoides pteronyssinus

We investigated variations in total IgE, and specific IgE, IgG, and IgG4 for Dermatophagoides pteronyssinus in 57 patients with perennial rhinitis due to house dust mite allergy in an open controlled study: 43 subjects received immunotherapy (17 subcutaneous, 14 sublingual, and 12 local immunotherapy) and 14 were controls. The results were compared with the clinical course to determine possible associations between serum and clinical changes. Subcutaneous, but not sublingual and nasal, immunotherapy induced a significant clinical benefit (P < .001). Specific antibody behavior in patients receiving subcutaneous immunotherapy was similar to literature reports. Specific IgE levels fell starting from the 6th month of therapy, and specific IgG and IgG4 levels rose significantly, but there was no correlation with the clinical course. The other two forms of immunotherapy did not induce significant specific antibody modifications. We conclude that the specific IgG4 rise induced by subcutaneous immunotherapy was the most important variation observed. This change, however, was not correlated with the clinical outcome.

Fatal septicaemia due to Listeria monocytogenes in a patient with systemic lupus erythematosus receiving cyclosporin and high prednisone doses

Cyclosporin A is widely used in organ transplantation, preventing the rejection of multiple types of organ allografts. It is also being increasingly used as an immunosuppressive agent to treat various autoimmune diseases in patients refractory to more commonly used immunosuppressive therapy. Several trials are currently evaluating the utility of this drug associated with corticosteroids in the treatment of systemic lupus erythematosus. This case, describing a lethal septicaemia caused by Listeria monocytogenes in a patient receiving this treatment, seems to indicate that the use of these "cocktails" of immunosuppressive drugs should be particularly cautious to prevent fatal infectious complications.

A localized pleuropulmonary lesion induced by long-term therapy with amiodarone

Pulmonary toxicity is an important adverse effect of amiodarone therapy that usually manifests as an acute or chronic diffuse lung disease; in rare cases localized lesions have also been described. We observed a solitary mass localized in the left lung base and involving the adjacent pleura in a 69-year-old man who had been treated for 1 year with amiodarone (cumulative dose 52 g). Cytological and histological examination showed that the lesion consisted of fibrotic tissue and a massive macrophagic infiltration. Following suspension of amiodarone and surgical excision, there was a complete recovery and the mass did not relapse. We confirm that respiratory complaints can occur in patients treated by long-term amiodarone therapy and that lung involvement can manifest with a solitary localized (fibrotic) lesion.

Lytic bone lesions and polyarthritis associated with acne fulminans

We describe a case of a male teenager, affected by acne fulminans. He had lytic bone lesions in both clavicles and arthritis of the right sacroiliac joint and spine. A bone scan showed increased uptake in these areas. Infection or a neoplastic disease was suspected but the cytological examination and the bacterial cultures of the material collected with a fine needle biopsy from the clavicular lesion were negative. The patient was treated with diclofenac and promptly recovered. Our report emphasizes that, although unusual, acne fulminans can be complicated by an erosive systemic arthritis and bone lesions. An immunological mechanism seems to be involved in this association.

Recurrent bacterial meningitis occurring five years after closed head injury and caused by an intranasal post-traumatic meningo-encephalocele

A case of atypical presentation of a post-traumatic intranasal meningo-encephalocele is described in a patient with a history of recurrent bacterial meningitis occurring 5 years after closed head injury. The usefulness of the CT and MRI findings in diagnostic evaluation of this lesion is emphasized.

Lymphocytic clusters in peripheral blood: an atypical morphologic pattern of chronic lymphocytic leukemia

A case of chronic lymphocytic leukemia is described in which peripheral blood and bone marrow films showed lymphocytes arranged in aggregates resembling epithelial cell clusters. Due to this morphological conformation, automatic hemogram screening was not able to detect the presence of chronic lymphocytic leukemia. Correct interpretation of a typical histogram pattern led to the final diagnosis.

[A rare case of recurrent meningitis: intranasal encephalocele]

Intranasal meningoencephalocele is a rare malformation characterized by a protrusion of brain tissue and meninges out of the cranial cavity into the nose, through a discontinuity of the ethmoidal cribriform plate. It is a congenital anomaly but it may be also due to trauma or to chronic intracranial hypertension. It is clinically apparent as a small mass that may be confused with nasal polyp. A cerebrospinal fluid leakage may be present. In a few cases it gives no symptoms until adulthood, but usually recurrent meningitis may occur. A case of young woman with intranasal encephalomeningocele who suffered from 18 episodes of meningitis is reported. Nevertheless she is at present without neurological consequences.

Femoral nerve palsy secondary to anticoagulant induced iliacus hematoma. A case report

A case of femoral neuropathy from iliac muscle hematoma occurring in a patient treated with urokinase, subcutaneous heparin and aspirin for myocardial infarction is reported. Diagnosis of this complication was suspected on the basis of clinical signs and on the fact that the patient had received anticoagulants. Computed tomography allowed direct and clear visualization of the hematoma. Anticoagulant suspension followed by an early surgical decompression seems to be the ideal treatment for this neuropathy; however, our patient died for a reinfarction after stopping heparinic administration. This may indicate that, in some patients "at risk", it is better to reduce rather than stop anticoagulant therapy.

Retroperitoneal, mediastinal and subcutaneous emphysema as a complication of routine upper gastrointestinal endoscopy

Diagnostic endoscopy of the upper gastrointestinal tract is a safe procedure, which, however, is not without complications. We report the rare occurrence of retroperitoneal, mediastinal and subcutaneous emphysema following routine endoscopy, with no obvious evidence of a site of perforation. Possible etiological aspects are discussed. This complication appeared to be a benign clinical condition that was resolved with conservative, nonsurgical treatment.

[Acute rhabdomyolysis, myoglobinuria and renal insufficiency caused by ethanol: review of the literature and description of a clinical case with fatal outcome]

Several studies demonstrated that alcohol can induce both chronic and acute myopathy with myoglobinuria. Acute rhabdomyolysis is commonly followed by a renal failure (R.F.) of variable degree. The Authors report a case of rhabdomyolysis induced acute R.F. in a chronic alcoholic young man. The patient died in irreversible shock. Early diagnosis of the disease seems to be important, because early treatment can prevent acute myoglobinuric R.F.

Painless giant cell thyroiditis

We describe an atypical case of subacute thyroiditis affecting a 50 year old patient with long lasting fever, weight loss, malaise and a high erythrocyte sedimentation rate. Cytological examination of the thyroid gland showed the classic granulomas with giant cells. However, the patient had neither painful enlargement of the gland nor thyrotoxicosis. This case, as well as others previously described, probably represents a new subtype of subacute thyroiditis, painless giant cell thyroiditis. The presence of painless giant cell thyroiditis should be considered in any patient with undiagnosed pyrexia, weight loss and elevated ESR.

[Infection and digestive bleeding: late complications of aortofemoral bypass surgery]

Graft-enteric fistulas and (the most uncommon) graft-enteric erosions are feared complications of aortic reconstructive surgery and infection and hemorrhage are their major clinical manifestations. A case considered unusual due to the simultaneous presence of two graft-enteric erosions: duodenal and sigmoid is reported. The first erosion was revealed by endoscopy performed for gastrointestinal bleeding. The role played by infection and mechanical factors in the pathogenesis of these complications is then discussed.

[Acute gastric volvulus]

Gastric volvulus is an uncommon condition in which a torsion of the stomach results in acute or chronic gastrointestinal symptoms. We report a case of an intrathoracic organo-axial gastric volvulus secondary to a hiatal hernia. The patient died after surgery. Even though it was a surgical emergency, the patient was admitted to a Medical Department because she was regularly examined by the Digestive Endoscopy Unit for a hiatal hernia. The Authors emphasize the contribution of endoscopy to the preoperative recognition of this condition.

Long-term follow-up in 257 ICA occlusion: comparison between EIAB-treated and untreated patients

The purpose of this paper is to estimate the real value of the Extra-Intracranial Arterial Bypass (EIAB) in preventing or reducing further and more catastrophic ischaemic events in patients suffering from an Internal Carotid Artery (ICA) occlusion. 257 patients, suffering from ICA occlusion, are considered retrospectively: 122 of them submitted to EIAB and 135 medically treated or untreated. In both groups, homogeneous by sex, age, neurological grading distribution and length of follow-up, the following parameters were considered: the incidence of ischaemic recurrences during the follow-up period; the characters of the recurrences with particular reference to the fatal stroke; the rate of ischaemic events per year. The comparison between the outcome in surgically treated patients and in "untreated" ones indicates that the EIAB can be effective in preventing or reducing the ischaemic recurrences and the frequency of fatal stroke in TIA-, RIND, or stroke-patients suffering from ICA occlusion.

Extra-intracranial arterial bypass in typical carotid reversible ischaemic deficits: long-term follow-up in 100 patients

The long-term follow-up of 100 consecutive patients who suffered from a reversible ischaemic attack (RIA) in the carotid territory and were submitted to extra-intracranial arterial bypass (EIAB) surgery in seven Italian Neurosurgical Centres is reported. The preoperative angiographic and clinical features, and the surgical complications are reported. The follow-up ranged from two to seven years with a mean of thirty-five months. In this period in the territory served by the bypass only two completed strokes and six RIAs occurred. Four patients died, only one for cerebral ischaemic problems. The results of the present series have been compared with those of the literature: they appeared consistent with other surgical series and clearly better than those of medical treated patients. The EIAB can then be considered a good therapeutic choice for the treatment of RIAs in carotid territory.

T mediated immunity in patients undergoing periodic hemodialysis

Seventeen patients with well compensated chronic renal failure undergoing periodic hemodialysis were studied with regard to absolute number of T and B lymphocytes, spontaneous and PHA induced lymphocyte blastogenesis both with autologous and homologous compatible plasma. A normal lymphocyte count as well as a normal relative and absolute number of T and B lymphocytes was found in most cases. Spontaneous blastogenesis was normal. Lymphocyte response to PHA was reduced both with autologous and homologous plasma, but the depression was more relevant when autologous plasma was used in culture. The authors discuss these findings with respect to available data, particularly concerning inhibitory factors in uraemic plasma.