Stress-free single-cell transcriptomic profiling and functional genomics of murine eosinophils

Eosinophils are a class of granulocytes with pleiotropic functions in homeostasis and various human diseases. Nevertheless, they are absent from conventional single-cell RNA sequencing atlases owing to technical difficulties preventing their transcriptomic interrogation. Consequently, eosinophil heterogeneity and the gene regulatory networks underpinning their diverse functions remain poorly understood. We have developed a stress-free protocol for single-cell RNA capture from murine tissue-resident eosinophils, which revealed distinct intestinal subsets and their roles in colitis. Here we describe in detail how to enrich eosinophils from multiple tissues of residence and how to capture high-quality single-cell transcriptomes by preventing transcript degradation. By combining magnetic eosinophil enrichment with microwell-based single-cell RNA capture (BD Rhapsody), our approach minimizes shear stress and processing time. Moreover, we report how to perform genome-wide CRISPR pooled genetic screening in ex vivo-conditioned bone marrow-derived eosinophils to functionally probe pathways required for their differentiation and intestinal maturation. These protocols can be performed by any researcher with basic skills in molecular biology and flow cytometry, and can be adapted to investigate other granulocytes, such as neutrophils and mast cells, thereby offering potential insights into their roles in both homeostasis and disease pathogenesis. Single-cell transcriptomics of eosinophils can be performed in 2-3 d, while functional genomics assays may require up to 1 month.

Identifying Spatial Co-occurrence in Healthy and InflAmed tissues (ISCHIA)

Sequencing-based spatial transcriptomics (ST) methods allow unbiased capturing of RNA molecules at barcoded spots, charting the distribution and localization of cell types and transcripts across a tissue. While the coarse resolution of these techniques is considered a disadvantage, we argue that the inherent proximity of transcriptomes captured on spots can be leveraged to reconstruct cellular networks. To this end, we developed ISCHIA (Identifying Spatial Co-occurrence in Healthy and InflAmed tissues), a computational framework to analyze the spatial co-occurrence of cell types and transcript species within spots. Co-occurrence analysis is complementary to differential gene expression, as it does not depend on the abundance of a given cell type or on the transcript expression levels, but rather on their spatial association in the tissue. We applied ISCHIA to analyze co-occurrence of cell types, ligands and receptors in a Visium dataset of human ulcerative colitis patients, and validated our findings at single-cell resolution on matched hybridization-based data. We uncover inflammation-induced cellular networks involving M cell and fibroblasts, as well as ligand-receptor interactions enriched in the inflamed human colon, and their associated gene signatures. Our results highlight the hypothesis-generating power and broad applicability of co-occurrence analysis on spatial transcriptomics data.

Fragment-sequencing unveils local tissue microenvironments at single-cell resolution

Cells collectively determine biological functions by communicating with each other-both through direct physical contact and secreted factors. Consequently, the local microenvironment of a cell influences its behavior, gene expression, and cellular crosstalk. Disruption of this microenvironment causes reciprocal changes in those features, which can lead to the development and progression of diseases. Hence, assessing the cellular transcriptome while simultaneously capturing the spatial relationships of cells within a tissue provides highly valuable insights into how cells communicate in health and disease. Yet, methods to probe the transcriptome often fail to preserve native spatial relationships, lack single-cell resolution, or are highly limited in throughput, i.e. lack the capacity to assess multiple environments simultaneously. Here, we introduce fragment-sequencing (fragment-seq), a method that enables the characterization of single-cell transcriptomes within multiple spatially distinct tissue microenvironments. We apply fragment-seq to a murine model of the metastatic liver to study liver zonation and the metastatic niche. This analysis reveals zonated genes and ligand-receptor interactions enriched in specific hepatic microenvironments. Finally, we apply fragment-seq to other tissues and species, demonstrating the adaptability of our method.

Development of Population-Based Pediatric Computational Phantoms for Radiotherapy Applications

PURPOSE/OBJECTIVE(S)

Age-specific pediatric computational phantoms are used in radiotherapy (RT) for quality assurance and for reconstruction of historical RT doses (within others). Phantoms are typically developed from healthy patients and may not effectively represent those with cancer due to pathology and/or treatment effects. This study evaluated a set of population-based pediatric computational phantoms developed in-house in terms of anatomical plausibility.

MATERIALS/METHODS

Planning CTs and contours from historical craniospinal irradiation (CSI) patients (n = 74, median age 7y, range: 1-17y) were used to generate and evaluate a set of in-house age-specific population-based RT phantoms (RT-P). The RT-P were generated by combining a sub-set of clinical CTs and contours through groupwise deformable image registration, generating average models of CSI sub-populations (n = 74, median age 7y, range: 3-14y). Models were then compared against clinical data and two libraries of phantoms representing healthy populations: the International Commission on Radiological Protection (ICRP) pediatric reference computational phantoms (n = 8, median age 8y, range: 1-15y) and a variety of default 4D extended cardiac torso (XCAT) phantoms (n = 75, median age 9y, range: 1-18y). Variation between organ volumes for the different datasets was assessed through a linear fit of organ volume with age, reporting the slope (∑) of each fit [y-1]. Average difference between the volume datapoints and the linear fit for clinical data (Δ) [%] were also reported. This allowed for comparisons of the RT-P to clinical and reference data in terms of organ volumes across developmental stages.

RESULTS

The table shows 9 of the 19 investigated organs. The ∑ reported for RT-P models were of similar magnitude as the clinical data and other phantoms, effectively modelling changes with age. The greatest and least ∑ were reported from lungs and thyroid respectively, in agreement with expected relative sizes between organs. Larger values for Δ were likely due to differences in organ filling and segmentation strategy between datasets, limitations of RT-P methodology, and/or anatomical differences between healthy and cancer populations.

CONCLUSION

The RT-P models show promise in representing the RT cohort that may benefit from specialized anatomical phantoms. Further work is needed to address the limitations of the current methodology and its applicability to other RT cohorts.

Active eosinophils regulate host defence and immune responses in colitis

In the past decade, single-cell transcriptomics has helped to uncover new cell types and states and led to the construction of a cellular compendium of health and disease. Despite this progress, some difficult-to-sequence cells remain absent from tissue atlases. Eosinophils-elusive granulocytes that are implicated in a plethora of human pathologies1-5-are among these uncharted cell types. The heterogeneity of eosinophils and the gene programs that underpin their pleiotropic functions remain poorly understood. Here we provide a comprehensive single-cell transcriptomic profiling of mouse eosinophils. We identify an active and a basal population of intestinal eosinophils, which differ in their transcriptome, surface proteome and spatial localization. By means of a genome-wide CRISPR inhibition screen and functional assays, we reveal a mechanism by which interleukin-33 (IL-33) and interferon-γ (IFNγ) induce the accumulation of active eosinophils in the inflamed colon. Active eosinophils are endowed with bactericidal and T cell regulatory activity, and express the co-stimulatory molecules CD80 and PD-L1. Notably, active eosinophils are enriched in the lamina propria of a small cohort of patients with inflammatory bowel disease, and are closely associated with CD4+ T cells. Our findings provide insights into the biology of eosinophils and highlight the crucial contribution of this cell type to intestinal homeostasis, immune regulation and host defence. Furthermore, we lay a framework for the characterization of eosinophils in human gastrointestinal diseases.

Cardiac involvement in creatine deficiency syndrome

Background

Previous reports have demonstrated electrocardiographic and echocardiographic abnormalities consistent with early-stage cardiomyopathy in patients with creatine transporter (CrT) deficiency, but cardiac involvement has never been accurately characterized.

Purpose

To investigate the cardiac phenotype associated with creatine deficiency in a murine transgenic model and in patients with creatine deficiency syndrome (CDS).

Methods

Wild type and transgenic CrT−/y mice (n=20) were serially evaluated in vivo by electrocardiogram (EKG) and echocardiography for six months, and ex vivo by histological and biochemical analyses. Nine patients with CDS (n=4 with L-arginine:glycine amidinotransferase - AGAT- deficiency, n=5 with CrT deficiency) underwent blood samples, including cardiac biomarkers, EKG, Holter monitoring, echocardiography and cardiac magnetic resonance (CMR).

Results

Compared to wild type, CRT−/y mice showed a prolongation of QT interval (p=0.008) (Fig. 1), as well as significant reduction in cardiac ATP production from mitochondria (p<0.001) (Fig. 2). No differences were detected in the left ventricular systolic function, in terms of ejection fraction and global longitudinal strain, along the whole follow-up. Similarly, 3 patients with CrT deficiency also showed a prolonged QTc interval (median QTc 515 ms), while other 2 had a borderline QTc at Holter monitoring, while no tachyarrhythmias could be observed. No subject had abnormal systolic and diastolic function. At CMR, an increase of native T1 value was reported in the 4 subjects (median 1076 ms) with AGAT deficiency, 1 with an increase of extracellular volume matching with the detection of late gadolinium enhancement. Finally, subjects with AGAT deficiency showed an increase level of plasma norepinephrine. Familiar carriers (3 for AGAT and 1 for CrT) showed no notable cardiac functional alterations, except for QTc prolongation in 2 subjects.

Conclusion

Prolonged QT interval is observed in the murine model and in subjects with CrT deficiency. Biohumoral signs of neurohormonal activation and an initial replacement fibrosis – the latter suggested by the increase of native T1 – are identified in subjects with AGAT deficiency, but their clinical significance remains to be determined.

Funding Acknowledgement

Type of funding sources: None.

In vivo adenine base editing of PCSK9 in macaques reduces LDL cholesterol levels

Most known pathogenic point mutations in humans are C•G to T•A substitutions, which can be directly repaired by adenine base editors (ABEs). In this study, we investigated the efficacy and safety of ABEs in the livers of mice and cynomolgus macaques for the reduction of blood low-density lipoprotein (LDL) levels. Lipid nanoparticle-based delivery of mRNA encoding an ABE and a single-guide RNA targeting PCSK9, a negative regulator of LDL, induced up to 67% editing (on average, 61%) in mice and up to 34% editing (on average, 26%) in macaques. Plasma PCSK9 and LDL levels were stably reduced by 95% and 58% in mice and by 32% and 14% in macaques, respectively. ABE mRNA was cleared rapidly, and no off-target mutations in genomic DNA were found. Re-dosing in macaques did not increase editing, possibly owing to the detected humoral immune response to ABE upon treatment. These findings support further investigation of ABEs to treat patients with monogenic liver diseases.

Differential regulation of β-catenin-mediated transcription via N- and C-terminal co-factors governs identity of murine intestinal epithelial stem cells

The homeostasis of the gut epithelium relies upon continuous renewal and proliferation of crypt-resident intestinal epithelial stem cells (IESCs). Wnt/β-catenin signaling is required for IESC maintenance, however, it remains unclear how this pathway selectively governs the identity and proliferative decisions of IESCs. Here, we took advantage of knock-in mice harboring transgenic β-catenin alleles with mutations that specifically impair the recruitment of N- or C-terminal transcriptional co-factors. We show that C-terminally-recruited transcriptional co-factors of β-catenin act as all-or-nothing regulators of Wnt-target gene expression. Blocking their interactions with β-catenin rapidly induces loss of IESCs and intestinal homeostasis. Conversely, N-terminally recruited co-factors fine-tune β-catenin's transcriptional output to ensure proper self-renewal and proliferative behaviour of IESCs. Impairment of N-terminal interactions triggers transient hyperproliferation of IESCs, eventually resulting in exhaustion of the self-renewing stem cell pool. IESC mis-differentiation, accompanied by unfolded protein response stress and immune infiltration, results in a process resembling aberrant "villisation" of intestinal crypts. Our data suggest that IESC-specific Wnt/β-catenin output requires selective modulation of gene expression by transcriptional co-factors.

Senescence Reprogramming by TIMP1 Deficiency Promotes Prostate Cancer Metastasis

Metastases account for most cancer-related deaths, yet the mechanisms underlying metastatic spread remain poorly understood. Recent evidence demonstrates that senescent cells, while initially restricting tumorigenesis, can induce tumor progression. Here, we identify the metalloproteinase inhibitor TIMP1 as a molecular switch that determines the effects of senescence in prostate cancer. Senescence driven either by PTEN deficiency or chemotherapy limits the progression of prostate cancer in mice. TIMP1 deletion allows senescence to promote metastasis, and elimination of senescent cells with a senolytic BCL-2 inhibitor impairs metastasis. Mechanistically, TIMP1 loss reprograms the senescence-associated secretory phenotype (SASP) of senescent tumor cells through activation of matrix metalloproteinases (MMPs). Loss of PTEN and TIMP1 in prostate cancer is frequent and correlates with resistance to docetaxel and worst clinical outcomes in patients treated in an adjuvant setting. Altogether, these findings provide insights into the dual roles of tumor-associated senescence and can potentially impact the treatment of prostate cancer.

Central and obstructive apneas prevalence in heart failure with reduced, mid-range and preserved ejection fraction

Background

Central apneas (CA) and obstructive apneas (OA) are highly prevalent in heart failure (HF) both with reduced and preserved systolic function. However, a comprehensive evaluation of apnea prevalence across HF according to ejection fraction (i.e HF with patients with reduced, mid-range and preserved ejection fraction- HFrEf, HFmrEF and HFpEF, respectively) throughout the 24 hours has never been done before.

Materials and methods

700 HF patients were prospectively enrolled and then divided according to left ventricular EF (408 HFrEF, 117 HFmrEF, 175 HFpEF). All patients underwent a thorough evaluation including: 2D echocardiography; 24-h Holter-ECG monitoring; cardiopulmonary exercise testing; neuro-hormonal assessment and 24-h cardiorespiratory monitoring.

Results

In the whole population, prevalence of normal breathing (NB), CA and OA at daytime was 40%, 51%, and 9%, respectively, while at nighttime 15%, 55%, and 30%, respectively.

When stratified according to left ventricular EF, CA prevalence decreased from HFrEF to HFmrEF and HFpEF: (daytime CA: 57% vs. 43% vs. 42%, respectively, p=0.001; nighttime CA: 66% vs. 48% vs. 34%, respectively, p<0.0001), while OA prevalence increased (daytime OA: 5% vs. 8% vs. 18%, respectively, p<0.0001; nighttime OA: 20 vs. 29 vs. 53%, respectively, p<0.0001).

When assessing moderte-severe apneas, defined with an apnea/hypopnea index >15 events/hour, prevalence of CA was again higher in HFrEF than HFmrEF and HFpEF both at daytime (daytime moderate-severe CA: 28% vs. 19% and 23%, respectively, p<0.05) and at nighttime (nighttime moderate-severe CA: 50% vs. 39% and 28%, respectively, p<0.05). Conversely, moderate-severe OA decreased from HFrEF to HFmrEF to HFpEF both at daytime (daytime moderate-severe OA: 1% vs. 3% and 8%, respectively, p<0.05) and nighttime (noghttime moderate-severe OA: 10% vs. 11% and 30%, respectively, p<0.05).

Conclusions

Daytime and nighttime apneas, both central and obstructive in nature, are highly prevalent in HF regardless of EF. Across the whole spectrum of HF, CA prevalence increases and OA decreases as left ventricular systolic dysfunction progresses, both during daytime and nighttime.

Funding Acknowledgement

Type of funding source: None

Central apneas and Ticagrelor related dyspnea in patients with acute coronary syndrome

Background

Patients treated with ticagrelor often develop dyspnea of unknown origin. We aim to explore the contribution of central apneas to ticagrelor-related dyspnea in patients with acute coronary syndrome (ACS).

Methods

We consecutively enrolled patients with ACS, preserved left ventricular ejection fraction and no history of obstructive sleep apnea, treated either with ticagrelor 90 mg bid (n=30) or prasugrel 10 mg od (n=24). One week after ACS onset, all patients underwent, beyond thorough cardiovascular and respiratory assessment, 24-hour cardiorespiratory monitoring and assessment of chemosensitivity to hypercapnia.

Results

Patients treated with ticagrelor reported more frequently dyspnea than patients treated with prasugrel (43% versus 4%, p=0.001), despite no difference in demographic, clinical, echocardiographic and pulmonary data. Patients with dyspnea induced by ticagrelor showed higher apnea-hypopnea and central apnea index both at daytime and at nighttime compared to patients treated with ticagrelor but without dyspnea and patients treated with prasugrel (daytime AHI: 26 [7–34] vs 6 [4–14] and 6 [0–11] events/hour; nighttime AHI: 65 [17–72] vs 22 [8–37] and vs 11 [4–23] events/hour; daytime CAI: 5 [1–15] vs 1 [0–6] and 0 [0–1) events/hour; nighttime CAI 34 [2–55] vs 3 [0–9] and 0 [0–1], all p<0.05). Likewise, they also presented with higher hypercapnic ventilatory response (2.4 [1.9–2.7] vs 1.3 [1.1–1.9] and 0.9 [0.5–2.1] L/min/mmHg, all p<0.05).

Conclusions

Central apneas should be considered a likely mechanism of dyspnea in ACS patients treated with ticagrelor. A drug-related sensitization of the chemoreflex may be the cause of ventilatory instability in this setting.

Funding Acknowledgement

Type of funding source: None

Sacubitril/valsartan improves ventilation stability in patients with chronic heart failure

Background

Sacubitril/valsartan (SV) ameliorates symptoms and prognosis in patients with heart failure and reduced ejection fraction (HFrEF), but the reasons for such effects are unclear. The impact of SV on ventilation has never been investigated. In HFrEF, apneas are highly prevalent both at daytime and nighttime and are associated with increased mortality.

Purpose

We hypothesize that treatment with SV could favourably stabilize ventilation by reducing the severity of central apneas in patients with HFrEF.

Methods

51 patients with HFrEF (mean age 67±9 years, mean left ventricular ejection fraction, LVEF 27±7%) and apneas defined by an apnea-hypopnea index, AHI≥5 (median 16, interquartile range 8–28) events/hour, eligible to treatment with SV and previously on optimal medical therapy for HFrEF, were enrolled. An extensive evaluation including cardiac ultrasound and a 24-hour cardiorespiratory monitoring was performed.

Results

After six months of treatment with SV, left ventricle systolic and diastolic function, mitral regurgitation (MR), left atrial volume (LAVI) and systolic pulmonary artery pressure (sPAP) were improved. Severity of apneas was reduced by 50%, 65% and 36% throughout the 24-hour, at daytime and nighttime, respectively.

Conclusion

Besides its known efficacy on cardiac remodeling, SV positively decreases the apneic burden in patients with HFrEF.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Roche Diagnostics unrestricted grant

TBX3 acts as tissue-specific component of the Wnt/β-catenin transcriptional complex

BCL9 and PYGO are β-catenin cofactors that enhance the transcription of Wnt target genes. They have been proposed as therapeutic targets to diminish Wnt signaling output in intestinal malignancies. Here we find that, in colorectal cancer cells and in developing mouse forelimbs, BCL9 proteins sustain the action of β-catenin in a largely PYGO-independent manner. Our genetic analyses implied that BCL9 necessitates other interaction partners in mediating its transcriptional output. We identified the transcription factor TBX3 as a candidate tissue-specific member of the β-catenin transcriptional complex. In developing forelimbs, both TBX3 and BCL9 occupy a large number of Wnt-responsive regulatory elements, genome-wide. Moreover, mutations in Bcl9 affect the expression of TBX3 targets in vivo, and modulation of TBX3 abundance impacts on Wnt target genes transcription in a β-catenin- and TCF/LEF-dependent manner. Finally, TBX3 overexpression exacerbates the metastatic potential of Wnt-dependent human colorectal cancer cells. Our work implicates TBX3 as context-dependent component of the Wnt/β-catenin-dependent transcriptional complex.

Single-Molecule RNA FISH in Whole-Mount Organoids

Single-molecule RNA fluorescent in situ hybridization (smFISH) enables the detection and quantification of single RNA molecules. Three-dimensional organoid cultures have emerged as versatile in vitro primary culture models that recapitulate many physiological features of their tissue of origin. Here we describe a protocol to visualize single RNA molecules in organoid cultures. Our method accommodates both a whole-mount staining workflow which requires spinning disk confocal microscopy, and a cryosectioning workflow which is compatible with widefield microscopy. Organoid smFISH enables to address various biological problems that range from the identification of cell types (e.g., via the intestinal stem cell marker Lgr5) to the quantification of RNA localization in an epithelium.

P215 Effects of ARNI therapy on left atrial and ventricular longitudinal deformation and functional capacity in HFrEF patients

Background

valsartan and sacubitril combination (angiotensin receptor-neprilysin inhibitor, ARNI) was superior, in randomized trials, to lone ACE inhibitors in terms of reduction of cardiovascular mortality rate and hospitalization for acute heart (HF) in patients with HF with reduced ejection fraction (HFrEF). Purpose: the main goal of our study was to assess the effects of ARNI on left atrial (LA) and left (LV) and right ventricular (RV) function, evaluated by standard and speckle tracking echocardiography (STE), and on patients’ functional capacity by cardiopulmonary exercise testing (CPET), in patients with HFrEF. Methods: we prospectively enrolled 16 patients with a LV EF ≤35% and >18 years old, in two different centers with high expertise in HF management. Exclusion criteria included: symptomatic hypotension, stage IV renal failure (eGFR < 30 ml/min/1.73 m2), ACE-inhibitor (ACEi) intolerance or previous angioedema, poor acoustic window, refuse to participate to the study. At enrollment (T0), all patients were in therapy with ACEi or sartans (ARBs) and underwent physical examination, ECG, blood test (including NT-proBNP), standard echo, STE and CPET. We shifted therapy from ACEi/ARBs according to HF guidelines and we repeated all tests after 6 months. Results: population had an average age of 63 ± 9 years, 94% was males. Etiology was ischemic in one third of the subjects. At 6 months follow up, NT-proBNP was significantly lower (512.2 ± 518.5 vs 431.2 ± 330.1 ng/l, p 0,001) together with reduced LV filling pressure evaluated by E/A ratio and E/e’ ratio (11.2 ± 8.6 vs 8.8 ± 4.8, p 0.01). LV EF improved from 31.7 ± 3.4% to 36.2 ± 7.2% (p 0.01) and LV dimensions decreased. LV global longitudinal strain (GLS) did not change significantly while free wall RV GLS increased from – 20.4 ± 6.3% to – 24.6 ± 9%, p 0.001, as peak atrial longitudinal strain (PALS) did (16.1 ± 2.6% vs 27.6 ± 4.1%, p 0.001). Between CPET indexes, only VE/VCO2 slope improved but only with borderline statistical significance (32.7 ± 5.3 vs 29.7 ± 6.8, p 0.05, Fig. 1). Conclusions: this preliminary study evaluated for the first time the effects of ARNI on echocardiographic and CPET parameters at the same time. Our results could explain the favorable clinical benefits of ARNI therapy in HFrEF: improved biventricular function, lower LV filling pressure and a more efficient ventilatory response during effort.

Abstract P215 Figure. Fig.1

P3525Buspirone effect on chemoreflex and central apneas in heart failure

Background

Increased chemosensitivity to carbon dioxide (CO2) is an important trigger of central apneas in heart failure (HF), contributing to HF progression and mortality. We hypothesized that buspirone, a 5HT1A receptor agonist that inhibits serotonergic chemoreceptor neuron firing in animals, can decrease CO2 chemosensitivity, thus preventing CA in patients with HF.

Methods

Sixteen patients with systolic HF (age 71.3±5.8 years, left ventricular ejection fraction 29.8±7.8%) and moderate-severe central apneas (nighttime apnea/hypopnea index AHI≥15 events/hour) underwent a double-blind, placebo-controlled, cross over, randomized study of oral buspirone administration (45 mg/day for 1 week).

Results

Buspirone reduced CO2 chemosensitivity compared to placebo (1.2 IR [1.1–1.5] vs. 2.0 [1.6–2.2] L/min/mmHg, p=0.008). Furthermore, buspirone improved: the AHI at nighttime (16.5 [8.5–24.7] vs. 27.5 [23.0–37.3] events/hour, p=0.002), and daytime (8.0 [2.3–11.5] vs. 11.5 [6.3–18.8] events/hour, p=0.006); the central apnea index at nighttime (4.0 [1.0–19.0] vs. 12.5 [8.3–27.3] events/hour, p=0.01) and daytime (1.0 [0.0–3.0] vs. 4.0 [1.3–6.0] events/hour, p=0.009); and the oxygen desaturation index at nighttime (4.7 [1.0–11.0] vs. 20.0 [8.7–26.5] events/hour, p=0.004) and daytime (0.2 [0.1–0.7] vs. 1.2 [0.3–4.8] events/hour, p=0.005). Buspirone showed a good safety profile and had no effect on neurohormones, arrhythmias, exercise capacity and mood/daytime sleepiness.

Conclusion

Buspirone reduces CO2 chemosensitivity and inhibits central apneas both during the day and the night in patients with systolic HF.

Composite membranes modified with recognition-able nanobeads as potential adsorbers for purification of biological fluids

Therapeutic approaches in the clinical field require advanced properties for delivery or recognition of clinical species. The molecular imprinting method allows selective cavities to be inserted into a polymeric material built ""around"" a stamp molecule (template) through polymerization or phase inversion. This study focuses on the application of both methods in the realization of polymeric membranes with selective recognition and adsorption properties. Imprinted polymethacrylic acid (PMAA) particles, exhibiting specific binding sites for cholesterol molecule (template), were realized via precipitation polymerization in the shape of nanobeads and loaded in the bulk or on the surface of methylmethacrylate-acrylic acid P(MMA-co-AA) membranes obtained by the non-solvent induced phase separation (NIPS) technique. In this way, specific cavities were introduced into the membrane network to enhance and specialize uptake performances of the porous membranes taking advantage of the particle characteristics. Rebinding performances towards cholesterol in a physiological environment were tested showing very interesting results: the adsorption of cholesterol molecules from physiological solution was increased by using composite membrane-nanobead systems instead of control membranes (a quantitative increase of 14 mg of cholesterol per g of polymer matrix in respect of blank membrane was detected). The results obtained showed an improved performance of composite membranes, but also an unmodified behavior of loaded nanobeads (with respect to free ones) concerning the recognition capability in aqueous medium, which is the most difficult obstacle to overcome in molecular imprinting. The absolute rebinding capacity and the imprinting efficiency of membranes were in the range (and in some case higher) of other efficient systems, but the real improvement was that molecularly imprinted embranes showed an excellent recognition capacity in physiological medium instead of organic solvents.

Cryotherapy in the prevention of oral mucositis in patients receiving low-dose methotrexate following myeloablative allogeneic stem cell transplantation: a prospective randomized study of the Gruppo Italiano Trapianto di Midollo Osseo nurses group

Severe oral mucositis is a major cause of morbidity following allogeneic hematopoietic stem cell transplantation (AHSCT). Cryotherapy, that is, the application of ice chips on the mucosa of the oral cavity during the administration of antineoplastic agents, may reduce the incidence and severity of chemotherapy-related oral mucositis. In this multicenter randomized study, we addressed whether cryotherapy during MTX administration is effective in the prevention of severe oral mucositis in patients undergoing myeloablative AHSCT. One hundred and thirty patients undergoing myeloablative AHSCT and MTX-containing GVHD prophylaxis were enrolled and randomized to receive or not receive cryotherapy during MTX administration. The incidence of severe (grade 3-4) oral mucositis, the primary end point of the study, was comparable in patients receiving or not cryotherapy. Moreover, no difference was observed in the incidence of oral mucositis grade 2-4 and the duration of oral mucositis grade 3-4 or 2-4, or in the kinetics of mucositis over time. In univariate and multivariate analysis, severe oral mucositis correlated with TBI in the conditioning regimen and lack of folinic acid rescue following MTX administration. Thus, cryotherapy during MTX administration does not reduce severe oral mucositis in patients undergoing myeloablative allogeneic HSCT. Future studies will assess cryotherapy before allogeneic HSCT.