ABSTRACT
Intestinal mucus barriers normally prevent microbial infections but are sensitive to diet-dependent changes in the luminal environment. Here we demonstrate that mice fed a Western-style diet (WSD) suffer regiospecific failure of the mucus barrier in the small intestinal jejunum caused by diet-induced mucus aggregation. Mucus barrier disruption due to either WSD exposure or chromosomal Muc2 deletion results in collapse of the commensal jejunal microbiota, which in turn sensitizes mice to atypical jejunal colonization by the enteric pathogen Citrobacter rodentium. We illustrate the jejunal mucus layer as a microbial habitat, and link the regiospecific mucus dependency of the microbiota to distinctive properties of the jejunal niche. Together, our data demonstrate a symbiotic mucus-microbiota relationship that normally prevents jejunal pathogen colonization, but is highly sensitive to disruption by exposure to a WSD.
Subject(s)
Intestinal Mucosa , Jejunum , Mucin-2 , Animals , Mice , Diet, Western , Intestinal Mucosa/metabolism , Intestinal Mucosa/microbiology , Intestine, Small , Mucin-2/genetics , Mucin-2/metabolism , Mucus , Citrobacter rodentium/physiologyABSTRACT
Background: Abnormal branched-chained amino acids (BCAA) accumulation in cardiomyocytes is associated with cardiac remodeling in heart failure. Administration of branched-chain α-keto acid dehydrogenase (BCKD) kinase inhibitor BT2 has been shown to reduce cardiac BCAA levels and demonstrated positive effects on cardiac function in a preclinical setting. The current study is focused on evaluating the impact of BT2 on the systemic and cardiac levels of BCAA and their metabolites as well as activities of BCAA catabolic enzymes using a quantitative systems pharmacology model. Methods: The model is composed of an ordinary differential equation system characterizing BCAA consumption with food, disposal in the proteins, reversible branched-chain-amino-acid aminotransferase (BCAT)-mediated transamination to branched-chain keto-acids (BCKA), followed by BCKD-mediated oxidation. Activity of BCKD is regulated by the balance of BCKDK and protein phosphatase 2Cm (PP2Cm) activities, affected by BT2 treatment. Cardiac BCAA levels are assumed to directly affect left ventricular ejection fraction (LVEF). Biochemical characteristics of the enzymes are taken from the public domains, while plasma and cardiac BCAA and BCKA levels in BT2 treated mice are used to inform the model parameters. Results: The model provides adequate reproduction of the experimental data and predicts synchronous BCAA responses in the systemic and cardiac space, dictated by rapid BCAA equilibration between the tissues. The model-based simulations indicate maximum possible effect of BT2 treatment on BCAA reduction to be 40% corresponding to 12% increase in LVEF. Model sensitivity analysis demonstrates strong impact of BCKDK and PP2Cm activities as well as total BCKD and co-substrate levels (glutamate, ketoglutarate and ATP) on BCAA and BCKA levels. Conclusion: Model based simulations confirms using of plasma measurements as a marker of cardiac BCAA changes under BCKDK inhibition. The proposed model can be used for optimization of preclinical study design for novel compounds targeting BCAA catabolism.
ABSTRACT
[This corrects the article DOI: 10.1016/j.clinms.2019.07.002.].
ABSTRACT
Haematohidrosis is a rare and dramatic condition in which bleeding occurs spontaneously from intact skin. We report the case of a nine-year-old boy with a typical clinical presentation. The case highlights how challenging it can be for medical professionals to recognise and evaluate rare conditions. A review of the literature was performed, showing that haematohidrosis is mainly a paediatric condition. Our case together with findings from the review indicates that treatment with Beta blockers may be effective for treatment of haematohidrosis in children. Conclusion: Paediatric haematohidrosis is a rare, but clinically distinct condition. Treatment with Beta blockers may be tested.
Subject(s)
Hemorrhage/diagnosis , Sweat Gland Diseases/diagnosis , Capillaries , Child , Humans , Male , Sweat Glands/blood supplyABSTRACT
Cerebrospinal fluid (CSF) tau and phospho-tau are well established biomarkers of Alzheimer's disease. While these measures are conventionally referred to as 'total tau' (T-tau) and 'phospho-tau' (P-tau), several truncated and modified tau forms exist that may relay additional diagnostic information. We evaluated the diagnostic performance of an endogenous tau peptide in CSF, tau 175-190, in the phosphorylated and non-phosphorylated state. A liquid chromatography-mass spectrometry (LC-MS) method was established to measure these peptides in CSF and was used to analyze two independent clinical cohorts; the first cohort included patients with Alzheimer's disease (AD, nâ¯=â¯15), Parkinson's disease (PD, nâ¯=â¯15), progressive supranuclear palsy (PSP, nâ¯=â¯15), and healthy controls (nâ¯=â¯15), the second cohort included AD patients (nâ¯=â¯16), and healthy controls (nâ¯=â¯24). In both cohorts T-tau and P-tau concentrations were determined by immunoassay. While tau 175-190 and P-tau 175-190 did not differentiate the study groups, the separation of AD and controls by T-tau (area under the ROC Curve (AUC)â¯=â¯95%) and P-tau (AUCâ¯=â¯92%) was improved when normalizing the ELISA measurements to the concentrations of the endogenous peptides: T-tau/tau 175-190 (AUCâ¯=â¯100%), P-tau/P-tau 175-190 (AUCâ¯=â¯95%). The separation between patients and controls by T-tau (AUCâ¯=â¯88%) and P-tau (AUCâ¯=â¯82%) was similarly improved in the second cohort by taking the ratios of T-tau/tau 175-190 (AUCâ¯=â¯97%) and P-tau/P-tau 175-190 (AUCâ¯=â¯98%). In conclusion, our results suggest that the performance of the AD biomarkers T-tau and P-tau could be improved by normalizing their measurements to the endogenous peptides tau 175-190 and P-tau 175-190, possibly because these endogenous tau peptides serve to normalize for physiological, and disease-independent, secretion of tau from neurons to the extracellular space and the CSF. Finally, the observations made here add to the general applicability of mass spectrometry as a tool for rapid identification and accurate quantification of biomarker candidates.
ABSTRACT
This protocol describes a method developed to identify endogenous peptides in human cerebrospinal fluid (CSF). For this purpose, a previously developed method based on molecular weight cut-off (MWCO) filtration and mass spectrometric analysis was combined with an offline high-pH reverse phase HPLC pre-fractionation step. Secretion into CSF is the main pathway for removal of molecules shed by cells of the central nervous system. Thus, many processes in the central nervous system are reflected in the CSF, rendering it a valuable diagnostic fluid. CSF has a complex composition, containing proteins that span a concentration range of 8 - 9 orders of magnitude. Besides proteins, previous studies have also demonstrated the presence of a large number of endogenous peptides. While less extensively studied than proteins, these may also hold potential interest as biomarkers. Endogenous peptides were separated from the CSF protein content through MWCO filtration. By removing a majority of the protein content from the sample, it is possible to increase the sample volume studied and thereby also the total amount of the endogenous peptides. The complexity of the filtrated peptide mixture was addressed by including a reverse phase (RP) HPLC pre-fractionation step at alkaline pH prior to LC-MS analysis. The fractionation was combined with a simple concatenation scheme where 60 fractions were pooled into 12, analysis time consumption could thereby be reduced while still largely avoiding co-elution. Automated peptide identification was performed by using three different peptide/protein identification software programs and subsequently combining the results. The different programs were complementary rather than comparable with less than 15% of the identifications overlapped between the three.
Subject(s)
Cerebrospinal Fluid/chemistry , Chromatography, Liquid/methods , Peptidomimetics/cerebrospinal fluid , Tandem Mass Spectrometry/methods , Cerebrospinal Fluid/cytology , HumansABSTRACT
We present a new, quantification-driven proteomic approach to identifying biomarkers. In contrast to the identification-driven approach, limited in scope to peptides that are identified by database searching in the first step, all MS data are considered to select biomarker candidates. The endopeptidome of cerebrospinal fluid from 40 Alzheimer's disease (AD) patients, 40 subjects with mild cognitive impairment, and 40 controls with subjective cognitive decline was analyzed using multiplex isobaric labeling. Spectral clustering was used to match MS/MS spectra. The top biomarker candidate cluster (215% higher in AD compared to controls, area under ROC curve = 0.96) was identified as a fragment of pleiotrophin located near the protein's C-terminus. Analysis of another cohort (n = 60 over four clinical groups) verified that the biomarker was increased in AD patients while no change in controls, Parkinson's disease or progressive supranuclear palsy was observed. The identification of the novel biomarker pleiotrophin 151-166 demonstrates that our quantification-driven proteomic approach is a promising method for biomarker discovery, which may be universally applicable in clinical proteomics.
Subject(s)
Alzheimer Disease/metabolism , Carrier Proteins/metabolism , Cytokines/metabolism , Peptides/metabolism , Proteome , Proteomics , Biomarkers , Carrier Proteins/chemistry , Cytokines/chemistry , Female , Humans , Male , Proteomics/methods , ROC Curve , Reproducibility of ResultsABSTRACT
Biomarkers of neurodegenerative disorders are needed to assist in diagnosis, to monitor disease progression and therapeutic interventions, and to provide insight into disease mechanisms. One route to identify such biomarkers is by proteomic and peptidomic analysis of cerebrospinal fluid (CSF). In the current study, we performed an in-depth analysis of the human CSF endopeptidome to establish an inventory that may serve as a basis for future targeted biomarker studies. High-pH RP HPLC was employed for off-line sample prefractionation followed by low-pH nano-LC-MS analysis. Different software programs and scoring algorithms for peptide identification were employed and compared. A total of 18 031 endogenous peptides were identified at a FDR of 1%, increasing the number of known endogenous CSF peptides 10-fold compared to previous studies. The peptides were derived from 2 053 proteins of which more than 60 have been linked to neurodegeneration. Notably, among the findings were six peptides derived from microtubule-associated protein tau, three of which span the diagnostically interesting threonine-181 (Tau-F isoform). Also, 213 peptides from amyloid precursor protein were identified, 58 of which were partially or completely within the sequence of amyloid ß 1-40/42, as well as 109 peptides from apolipoprotein E, spanning sequences that discriminate between the E2/E3/E4 isoforms of the protein.
Subject(s)
Cerebrospinal Fluid Proteins/analysis , Peptides/cerebrospinal fluid , Proteomics/methods , Biomarkers/cerebrospinal fluid , Chromatography, Liquid/methods , Humans , Mass Spectrometry/methods , Neurodegenerative Diseases/cerebrospinal fluid , SoftwareABSTRACT
Aberrant tau phosphorylation is a hallmark in Alzheimer's disease (AD), believed to promote formation of paired helical filaments, the main constituent of neurofibrillary tangles in the brain. While cerebrospinal fluid (CSF) levels of total tau and tau phosphorylated at threonine residue 181 (pThr181) are established core biomarkers for AD, the value of alternative phosphorylation sites, which may have more direct relevance to pathology, for early diagnosis is not yet known, largely due to their low levels in CSF and lack of standardized detection methods. To overcome sensitivity limitations for analysis of phosphorylated tau in CSF, we have applied an innovative mass spectrometry (MS) workflow, TMTcalibratortrademark, to enrich and enhance the detection of phosphoproteome components of AD brain tissue in CSF, and enable the quantitation of these analytes. We aimed to identify which tau species present in the AD brain are also detectable in CSF and which, if any, are differentially regulated with disease. Over 75% coverage of full-length (2N4R) tau was detected in the CSF with 47 phosphopeptides covering 31 different phosphorylation sites. Of these, 11 phosphopeptides were upregulated by at least 40%, along with an overall increase in tau levels in the CSF of AD patients relative to controls. Use of the TMTcalibratortrademark workflow dramatically improved our ability to detect tau-derived peptides that are directly related to human AD pathology. Further validation of regulated tau peptides as early biomarkers of AD is warranted and is currently being undertaken.
Subject(s)
Alzheimer Disease/cerebrospinal fluid , Mass Spectrometry , tau Proteins/cerebrospinal fluid , Amyloid beta-Peptides/cerebrospinal fluid , Biomarkers/cerebrospinal fluid , Brain Chemistry , Cohort Studies , Enzyme-Linked Immunosorbent Assay , Humans , Peptide Fragments/cerebrospinal fluid , Phosphorylation , tau Proteins/chemistryABSTRACT
The syntheses and single crystal X-ray structures of [Ag(5-nitroquinoline)2]NO3 (1), [Ag(8-nitroquinoline)2]NO3·H2O (2), [Ag(6-methoxy-8-nitroquinoline)(NO3)]n (3), [Ag(3-quinolinecarbonitrile)(NO3)]n (4), [Ag(3-quinolinecarbonitrile)2]NO3 (5), and [Ag(6-quinolinecarboxylic acid)2]NO3 (6) are described. As an alternative to solution chemistry, solid-state grinding could be used to prepare compounds 1 and 3, but the preparation of 4 and 5 in this way failed. The Ag(I) ions in the monomeric compounds 1, 2, 5, and 6 are coordinated to two ligands via the nitrogen atoms of the quinoline rings, thereby forming a distorted linear coordination geometry with Ag-N bond distances of 2.142(2)-2.336(2) Å and N-Ag-N bond angles of 163.62(13)°-172.25(13)°. The 1D coordination polymers 3 and 4 contain Ag(I) centers coordinating one ligand and two bridging nitrate groups, thereby forming a distorted trigonal planar coordination geometry with Ag-N bond distances of 2.2700(14) and 2.224(5) Å, Ag-O bond distances of 2.261(4)-2.536(5) Å, and N-Ag-O bond angles of 115.23(5)°-155.56(5)°. Hirshfeld surface analyses of compounds 1-6 are presented as d(norm) and curvedness maps. The d(norm) maps show different interaction sites around the Ag(I) ions, i.e., Ag···Ag interactions and possible O-H···O, C-H···O, C-H···N, and C-H···C hydrogen bonds. Curvedness maps are a good way of visualizing π-π stacking interactions between molecules. The antimicrobial activities of compounds 1, 2, and 6 were screened against 15 different multidrug-resistant strains of bacteria isolated from diabetic foot ulcers and compared to the antimicrobial activities of the clinically used silver sulfadiazine (SS). Compound 2 showed activity similar to SS against this set of test organisms, being active against all strains and having slightly better average silver efficiency than SS (5 vs 6 µg Ag/mL). Against the standard nonresistant bacterial strains of Staphylococcus aureus , Pseudomonas aeruginosa , Proteus mirabilis , and Streptococcus pyogenes , compound 1 performed better than silver nitrate, with an average MIC of 6 µg Ag/mL versus 18 µg Ag/mL for the reference AgNO3. Electrospray ionization mass spectrometry (ESI-MS) analyses of compounds 3 and 6 in DMSO/MeOH confirm the two-coordinated Ag(+) complexes in solution, and the results of the (1)H NMR titrations of DMSO solutions of 5-nitroquinoline and 8-nitroquinoline with AgNO3 in DMSO suggest that 5-nitroquinoline is more strongly coordinated to the silver ion.
Subject(s)
Anti-Infective Agents/chemical synthesis , Coordination Complexes/chemical synthesis , Quinolines/chemistry , Silver/chemistry , Anti-Infective Agents/pharmacology , Coordination Complexes/pharmacology , Crystallography, X-Ray , Hydrogen Bonding , Ligands , Microbial Sensitivity Tests , Models, Molecular , Proteus mirabilis/drug effects , Proteus mirabilis/growth & development , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/growth & development , Spectrometry, Mass, Electrospray Ionization , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & development , Streptococcus pyogenes/drug effects , Streptococcus pyogenes/growth & development , Structure-Activity RelationshipABSTRACT
BACKGROUND AND PURPOSE: Few studies have explored the potential clinical advantages of dose escalation and integrated boosts for patients with non-resectable locally advanced rectal cancer. The possibility of escalating dose to non-resectable regions in these patients was the aim of this study. PATIENTS AND METHODS: Seven patients with locally very advanced rectal tumours (sacrum overgrowth or growth into pelvic side walls) were evaluated. Intensity modulated photon and pencil beam scanning proton plans with simultaneously integrated boosts (45 Gy to elective lymph nodes, 50 Gy to tumour and 62.5 Gy to boost area in 25 fractions) were compared. RESULTS: Target coverage was achieved with both photon and proton plans. Estimated risks of acute side effects put the two patients with the largest tumours at unacceptable risk for intestinal toxicity, regardless of modality. The remaining five patients had beneficial sparing of dose to the small intestine with protons. CONCLUSIONS: Adding boost to areas where rectal tumours infiltrate adjacent non-resectable organs is an attractive option which appears possible using both photon and proton irradiation. Proton plans reduced dose to organs at risk. Integrated peripheral boosts should be considered more frequently in these very advanced tumours.
Subject(s)
Carcinoma/radiotherapy , Radiotherapy, Conformal/methods , Rectal Neoplasms/radiotherapy , Aged , Carcinoma/diagnostic imaging , Carcinoma/pathology , Carcinoma/surgery , Chemoradiotherapy , Combined Modality Therapy , Disease Progression , Female , Fluorodeoxyglucose F18 , Humans , Lymphatic Metastasis , Male , Middle Aged , Multimodal Imaging , Neoplasm Invasiveness , Positron-Emission Tomography , Preoperative Period , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted/methods , Radiotherapy, Adjuvant/adverse effects , Radiotherapy, Conformal/adverse effects , Rectal Neoplasms/diagnostic imaging , Rectal Neoplasms/pathology , Rectal Neoplasms/surgery , Tomography, X-Ray Computed , Treatment Outcome , Tumor BurdenABSTRACT
PURPOSE: Accurate delineation of target volumes is important to maximize radiation dose to the tumor and minimize it to nontumor tissue. Computed tomography (CT) and magnetic resonance imaging (MRI) are standard imaging modalities in rectal cancer. The aim was to explore whether functional imaging with F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET), combined with CT (FDG-PET/CT) gives additional information to standard pretreatment evaluation and changes the shape and size of the gross tumor volume (GTV). METHODS AND MATERIALS: From 2007 to 2009, 77 consecutive patients with locally advanced rectal cancer were prospectively screened for inclusion in the study at two university hospitals in Sweden, and 68 patients were eligible. Standard GTV was delineated using information from clinical examination, CT, and MRI (GTV-MRI). Thereafter, a GTV-PET was defined in the fused PET-CT, and the target volume delineations were compared for total volume, overlap, and mismatch. Pathologic uptake suspect of metastases was also registered. RESULTS: The median volume of GTV-MRI was larger than that of GTV-PET: 111 cm(3) vs. 87 cm(3) (p < 0.001). In many cases, the GTV-MRI contained the GTV defined on the PET/CT images as subvolumes, but when a GTV total was calculated after the addition of GTV-PET to GTV-MRI, the volume increased, with median 11% (range, 0.5-72%). New lesions were seen in 15% of the patients for whom PET/CT was used. CONCLUSIONS: FDG-PET/CT facilitates and adds important information to the standard delineation procedure of locally advanced rectal cancer, mostly resulting in a smaller GTV, but a larger total GTV using the union of GTV-MRI and GTV-PET. New lesions were sometimes seen, potentially changing the treatment strategy.
Subject(s)
Magnetic Resonance Imaging , Multimodal Imaging , Positron-Emission Tomography , Rectal Neoplasms/diagnostic imaging , Rectal Neoplasms/pathology , Tomography, X-Ray Computed , Tumor Burden , Adult , Aged , Aged, 80 and over , Female , Fluorodeoxyglucose F18 , Humans , Male , Middle Aged , Prospective Studies , Radiopharmaceuticals , Radiotherapy Planning, Computer-Assisted/methods , Rectal Neoplasms/radiotherapy , SwedenABSTRACT
BACKGROUND AND PURPOSE: According to the manual of the cementless Link MP reconstruction prosthesis, a distal femoral stem-bone anchorage of at least 80 mm is necessary to gain implant stability. There have been no in vivo studies showing that this distance is either achieved in clinical practice or needed for clinically satisfying results. Thus, we assessed the femoral stem-bone anchorage of the MP prosthesis using CT. METHODS: 14 patients with the MP stem were evaluated by CT scans at a median follow-up time of 12 months postoperatively. Femoral stem-bone anchorage was defined as adequate if 50% of the stem flutes or more had cortical bone contact. The length of anchorage was derived from the number of slices with adequate anchorage. Clinical outcome was assessed with VAS for pain and Harris hip score (HHS), both at 1 and 5 years of follow-up. RESULTS: The median length of stem-bone anchorage was 33 mm (interquartile range 10-60), which was shorter than recommended (p = 0.002). Still, at the 1-year control, all patients were fully weight-bearing and only 1/14 complained about mild thigh pain. 7/14 patients did not experience any pain in the affected hip. The patients had a median of 85 points in the HHS. The clinical outcome at 5 years was unchanged. INTERPRETATION: We found that it can be difficult to achieve a stem-bone anchorage of at least 80 mm for the MP Link prosthesis. However, this does not appear to be necessary to obtain stability and to achieve clinically satisfying results.
Subject(s)
Arthroplasty, Replacement, Hip , Hip Prosthesis , Prosthesis Failure , Aged , Aged, 80 and over , Arthroplasty, Replacement, Hip/adverse effects , Arthroplasty, Replacement, Hip/methods , Cementation , Female , Follow-Up Studies , Hip Joint/diagnostic imaging , Hip Prosthesis/adverse effects , Humans , Male , Middle Aged , Prosthesis Design , Reoperation , Tomography, X-Ray Computed , Treatment Outcome , Weight-BearingABSTRACT
The aim was to study the influence of mesorectal volume, as estimated by magnetic resonance imaging (MRI), that is to be removed during total mesorectal excision (TME), on the accuracy of the first preoperative MRI of rectal cancer compared to histopathology, and its correlation to locoregional prognostic factors. A total of 267 rectal cancer patients from a multinational study (MERCURY or MRI equivalence study) had their mesorectal volume retrospectively estimated by researchers without knowledge of the assessments made by the radiologist or the pathologist. The evaluations made by the pathologist and the radiologist were then compared, including T- and N-staging, assessment of extent of extramural tumor invasion (the largest portion of the tumor beyond the muscularis propria or EMI) and distance to mesorectal fascia; the discrepancies in the results were correlated to the mesorectal volume. T- or N-staging accuracy by MRI and the difference between the EMI as measured by the pathologist and the radiologist were not dependent on individual mesorectal volume. There was no correlation between assessment of involvement of mesorectal fascia or local neighboring organs by MRI and histopathology with mesorectal volume. Mesorectal volume does not affect locoregional prognostic factors or the accuracy of local staging of rectal cancer.