Impact of Asialoglycoprotein Receptor and Mannose Receptor Deficiency on Murine Plasma N-glycome Profiles.

The asialoglycoprotein receptor (ASGPR) and the mannose receptor C-type 1 (MRC1) are well known for their selective recognition and clearance of circulating glycoproteins. Terminal galactose and N-Acetylgalactosamine are recognized by ASGPR, while terminal mannose, fucose, and N-Acetylglucosamine are recognized by MRC1. The effects of ASGPR and MRC1 deficiency on the N-glycosylation of individual circulating proteins have been studied. However, the impact on the homeostasis of the major plasma glycoproteins is debated and their glycosylation has not been mapped with high molecular resolution in this context. Therefore, we evaluated the total plasma N-glycome and plasma proteome of ASGR1 and MRC1 deficient mice. ASGPR deficiency resulted in an increase in O-acetylation of sialic acids accompanied by higher levels of apolipoprotein D, haptoglobin, and vitronectin. MRC1 deficiency decreased fucosylation without affecting the abundance of the major circulating glycoproteins. Our findings confirm that concentrations and N-glycosylation of the major plasma proteins are tightly controlled and further suggest that glycan-binding receptors have redundancy, allowing compensation for the loss of one major clearance receptor.

Identification and validation of two peptide markers for the recognition of Clostridioides difficile MLST-1 and MLST-11 by MALDI-MS.

OBJECTIVES: Clostridioides difficile infection (CDI) has become the main cause of nosocomial infective diarrhoea. To survey and control the spread of different C. difficile strains, there is a need for suitable rapid tests. The aim of this study was to identify peptide/protein markers for the rapid recognition of C. difficile strains by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). METHODS: We analysed 44 well-characterized strains, belonging to eight different multi-locus sequence types (MLST), using ultrahigh-resolution Fourier transform ion cyclotron resonance (FTICR) MS. The amino acid sequence of two peptide markers specific for MLST-1 and MLST-11 strains was elucidated by MALDI-TOF-MS/MS. The investigation of 2689 C. difficile genomes allowed the determination of the sensitivity and specificity of these markers. C18-solid-phased extraction was used to enrich the MLST-1 marker. RESULTS: Two peptide markers (m/z 4927.81 and m/z 5001.84) were identified and characterized for MLST-1 and MLST-11 strains, respectively. The MLST-1 marker was found in 786 genomes of which three did not belong to MLST-1. The MLST-11 marker was found in 319 genomes, of which 14 did not belong to MLST-11. Importantly, all MLST-1 and MLST-11 genomes were positive for their respective marker. Furthermore, a peptide marker (m/z 5015.86) specific for MLST-15 was found in 59 genomes. We translated our findings into a fast and simple method that allowed the unambiguous identification of the MLST-1 marker on a MALDI-TOF-MS platform. CONCLUSIONS: MALDI-FTICR MS-based peptide profiling resulted in the identification of peptide markers for C. difficile MLST-1 and MLST-11.

Ultra-High Mass Resolution MALDI Imaging Mass Spectrometry of Proteins and Metabolites in a Mouse Model of Glioblastoma.

MALDI mass spectrometry imaging is able to simultaneously determine the spatial distribution of hundreds of molecules directly from tissue sections, without labeling and without prior knowledge. Ultra-high mass resolution measurements based on Fourier-transform mass spectrometry have been utilized to resolve isobaric lipids, metabolites and tryptic peptides. Here we demonstrate the potential of 15T MALDI-FTICR MSI for molecular pathology in a mouse model of high-grade glioma. The high mass accuracy and resolving power of high field FTICR MSI enabled tumor specific proteoforms, and tumor-specific proteins with overlapping and isobaric isotopic distributions to be clearly resolved. The protein ions detected by MALDI MSI were assigned to proteins identified by region-specific microproteomics (0.8 mm2 regions isolated using laser capture microdissection) on the basis of exact mass and isotopic distribution. These label free quantitative experiments also confirmed the protein expression changes observed by MALDI MSI and revealed changes in key metabolic proteins, which were supported by in-situ metabolite MALDI MSI.

Incidence of neoplastic disease following lung transplantation: a 17-year single-center experience.

OBJECTIVE: Chronic immunosuppressive therapy following solid organ transplantation has been correlated with an increased risk of posttransplantation neoplastic disease (PTND). In this study we evaluated PTND incidence and outcome at our institution over a 17-year period among patients receiving lung transplantation. MATERIALS AND METHODS: Between February 1992 and December 2008, we performed 290 lung transplantations in 280 patients, including 139 single (48% with 5 retransplantations), and 151 double lung transplantations (52% with 5 retransplantations). Among the 280 patients, 2 had undergone previous double lung transplantation in other hospitals. Follow-up of transplant recipients was performed up to December 2009. RESULTS: Forty-two patients died in the hospital, producing a cumulative early (30-day) mortality rate of 15%. Among the 238 patients discharged from the hospital who entered our follow-up program, 36 (15%) experienced PTND. The mean time between transplantation and diagnosis was 47 ± 42 months, and patients' mean age at time of diagnosis was 55 ± 14 years. Overall freedom from PTND was 97%, 84%, and 73% at 1, 5, and 10 years, respectively. PTND was considered to be the direct cause of death in 11 patients (30%). Overall survival of patients with PTND at five years (45%) did not differ from the remainder of the transplanted population (46%). However, PTND became a relevant cause of death in the long-term (>5 years) follow-up. CONCLUSION: Our experience confirms that PTND was frequently diagnosed following lung transplantation. Even if PTND did not seem to significantly affect the survival of patients undergoing lung transplantation, it may become a significant cause of death among those surviving beyond 5 years.

Management of anaplastic thyroid carcinoma spread over the trachea with mediastinal extension.

INTRODUCTION: We report a case of treatment of anaplastic thyroid carcinoma spread over the trachea with mediastinal extension. METHODS: Case report and review of the world literature concerning the treatment of anaplastic thyroid carcinoma are presented. DISCUSSION: The role of surgery in treatment of anaplastic carcinoma remains controversial. Our case we underlined two questions: the appropriateness of the surgery options with extra-thyroid spread and the better surgery approach to anaplastic thyroid carcinoma interesting the mediastinum controlling the great vessels of the neck. Even if curative resection cannot be achieved, surgical resection can immediately reduce the tumor bulk to facilitate the efficacy of post-operative radiotherapy and/or chemotherapy and to achieve a good local control to avoid the need of a subsequent palliative tracheostomy. Tumor upper mediastinal involvement made mandatory to open the sternum in order to allow a more complete resection of the macroscopic mass. The mini-sternotomy represents a valuable alternative that allows reduction in surgical trauma increasing patient's comfort. CONCLUSION: The complete resection of the tumor mass without scarifying vital structures can lead to some prolonged survival. Even if complete resection cannot be achieved, surgical resection can immediately reduce the tumour bulk and achieve good local control of the disease to avoid the palliative tracheotomy.