A top-down proteomic approach reveals a salivary protein profile able to classify Parkinson's disease with respect to Alzheimer's disease patients and to healthy controls

Parkinson's disease (PD) is a complex neurodegenerative disease with motor and non-motor symptoms. Diagnosis is complicated by lack of reliable biomarkers. To individuate peptides and/or proteins with diagnostic potential for early diagnosis, severity and discrimination from similar pathologies, the salivary proteome in 36 PD patients was investigated in comparison with 36 healthy controls (HC) and 35 Alzheimer's disease (AD) patients. A top-down platform based on HPLC-ESI-IT-MS allowed characterizing and quantifying intact peptides, small proteins and their PTMs (overall 51). The three groups showed significantly different protein profiles, PD showed the highest levels of cystatin SA and antileukoproteinase and the lowest of cystatin SN and some statherin proteoforms. HC exhibited the lowest abundance of thymosin β4, short S100A9, cystatin A, and dimeric cystatin B. AD patients showed the highest abundance of α-defensins and short oxidized S100A9. Moreover, different proteoforms of the same protein, as S-cysteinylated and S-glutathionylated cystatin B, showed opposite trends in the two pathological groups. Statherin, cystatins SA and SN classified accurately PD from HC and AD subjects. α-defensins, histatin 1, oxidized S100A9, and P-B fragments were the best classifying factors between PD and AD patients. Interestingly statherin and thymosin β4 correlated with defective olfactory functions in PD patients. All these outcomes highlighted implications of specific proteoforms involved in the innate-immune response and inflammation regulation at oral and systemic level, suggesting a possible panel of molecular and clinical markers suitable to recognize subjects affected by PD.

Combined Salivary Proteome Profiling and Machine Learning Analysis Provides Insight into Molecular Signature for Autoimmune Liver Diseases Classification

Autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) are autoimmune liver diseases that target the liver and have a wide spectrum of presentation. A global overview of quantitative variations on the salivary proteome in presence of these two pathologies is investigated in this study. The acid-insoluble salivary fraction of AIH and PBC patients, and healthy controls (HCs), was analyzed using a gel-based bottom-up proteomic approach combined with a robust machine learning statistical analysis of the dataset. The abundance of Arginase, Junction plakoglobin, Desmoplakin, Hexokinase-3 and Desmocollin-1 decreased, while that of BPI fold-containing family A member 2 increased in AIHp compared to HCs; the abundance of Gelsolin, CD14, Tumor-associated calcium signal transducer 2, Clusterin, Heterogeneous nuclear ribonucleoproteins A2/B1, Cofilin-1 and BPI fold-containing family B member 2 increased in PBCp compared to HCs. The abundance of Hornerin decreased in both AIHp and PBCp with respect to HCs and provided an area under the ROC curve of 0.939. Machine learning analysis confirmed the feasibility of the salivary proteome to discriminate groups of subjects based on AIH or PBC occurrence as previously suggested by our group. The topology-based functional enrichment analysis performed on these potential salivary biomarkers highlights an enrichment of terms mostly related to the immune system, but also with a strong involvement in liver fibrosis process and with antimicrobial activity.

Salivary Proteomics Reveals Significant Changes in Relation to Alzheimer's Disease and Aging

BACKGROUND

Aging is a risk factor for several pathologies as Alzheimer's disease (AD). Great interest exists, therefore, in discovering diagnostic biomarkers and indicators discriminating biological aging and health status. To this aim, omic investigations of biological matrices, as saliva, whose sampling is easy and non-invasive, offer great potential.

OBJECTIVE

Investigate the salivary proteome through a statistical comparison of the proteomic data by several approaches to highlight quali-/quantitative variations associated specifically either to aging or to AD occurrence, and, thus, able to classify the subjects.

METHODS

Salivary proteomic data of healthy controls under-70 (adults) and over-70 (elderly) years old, and over-70 AD patients, obtained by liquid chromatography/mass spectrometry, were analyzed by multiple Mann-Whitney test, Kendall correlation, and Random-Forest (RF) analysis.

RESULTS

Almost all the investigated proteins/peptides significantly decreased in relation to aging in elderly subjects, with or without AD, in comparison with adults. AD subjects exhibited the highest levels of α-defensins, thymosin β4, cystatin B, S100A8 and A9. Correlation tests also highlighted age/disease associated differences. RF analysis individuated quali-/quantitative variations in 20 components, as oxidized S100A8 and S100A9, α-defensin 3, P-B peptide, able to classify with great accuracy the subjects into the three groups.

CONCLUSION

The findings demonstrated a strong change of the salivary protein profile in relation to the aging. Potential biomarkers candidates of AD were individuated in peptides/proteins involved in antimicrobial defense, innate immune system, inflammation, and in oxidative stress. RF analysis revealed the feasibility of the salivary proteome to discriminate groups of subjects based on age and health status.

Predictive validity for the clinical diagnosis of a new parent questionnaire, the CABI, compared with CBCL

BACKGROUND

The questionnaires completed by the parents give a first general information on the behavioral problems of the child-adolescent, as a useful orientation to the clinical evaluation. The Child and Adolescent Behavior Inventory (CABI) is a 75-item parent questionnaire, which explores a large number of problem areas. The study of its predictive validity for the clinical diagnosis, in comparison with the Diagnostic and Statistical Manual of Mental Disorders (DSM)-oriented scales of the Child Behavior Checklist (CBCL), can assess whether its use may be advantageous.

MATERIAL AND METHODS

Parents/caregivers of 462 children and adolescents responded to both CABI and CBCL as a preliminary routine investigation. The results were compared with those of diagnoses obtained after the completion of the usual clinical procedure.

RESULTS

Accuracy values (probability of correct classification) resulted high for both instruments and significantly better for CABI anxiety and attention-deficit hyperactivity disorder (ADHD) scales, and for CBCL oppositional defiant disorder (ODD) and conduct disorder (CD) scales; no significant difference was found for depression scales. All the areas under the curve (AUC) of the receiver operating characteristic analysis reached excellent values, suggesting a very good predictive ability of the five scales of the two instruments. The comparison of AUC showed the CABI's anxiety and ADHD scales to give significantly higher values than those of CBCL, indicating that these two scales have a better predictive ability.

CONCLUSION

The study indicates a very good comparative (vs CBCL) and predictive validity of the CABI, suggesting an advantage in the use of this shorter questionnaire, available for free use both for clinical practice and supposedly for screening and epidemiological evaluations.

Molecular Signature and Mechanisms of Hepatitis D Virus-Associated Hepatocellular Carcinoma

There is limited data on the molecular mechanisms whereby hepatitis D virus (HDV) promotes liver cancer. Therefore, serum and liver specimens obtained at the time of liver transplantation from well-characterized patients with HDV-HCC (n = 5) and with non-HCC HDV cirrhosis (n = 7) were studied using an integrated genomic approach. Transcriptomic profiling was performed using laser capture-microdissected (LCM) malignant and nonmalignant hepatocytes, tumorous and nontumorous liver tissue from patients with HDV-HCC, and liver tissue from patients with non-HCC HDV cirrhosis. HDV-HCC was also compared with hepatitis B virus (HBV) HBV-HCC alone, and hepatitis C virus (HCV) HCV-HCC. HDV malignant hepatocytes were characterized by an enrichment of upregulated transcripts associated with pathways involved in cell-cycle/DNA replication, damage, and repair (Sonic Hedgehog, GADD45, DNA-damage-induced 14-3-3σ, cyclins and cell-cycle regulation, cell cycle: G₂-M DNA-damage checkpoint regulation, and hereditary breast cancer). Moreover, a large network of genes identified functionally relate to DNA repair, cell cycle, mitotic apparatus, and cell division, including 4 cancer testis antigen genes, attesting to the critical role of genetic instability in this tumor. Besides being overexpressed, these genes were also strongly coregulated. Gene coregulation was high not only when compared with nonmalignant hepatocytes, but also to malignant hepatocytes from HBV-HCC alone or HCV-HCC. Activation and coregulation of genes critically associated with DNA replication, damage, and repair point to genetic instability as an important mechanism of HDV hepatocarcinogenesis. This specific HDV-HCC trait emerged also from the comparison of the molecular pathways identified for each hepatitis virus-associated HCC. Despite the dependence of HDV on HBV, these findings suggest that HDV and HBV promote carcinogenesis by distinct molecular mechanisms.Implications: This study identifies a molecular signature of HDV-associated hepatocellular carcinoma and suggests the potential for new biomarkers for early diagnostics. Mol Cancer Res; 16(9); 1406-19. ©2018 AACR.

Infection with hepatitis C virus depends on TACSTD2, a regulator of claudin-1 and occludin highly downregulated in hepatocellular carcinoma

Entry of hepatitis C virus (HCV) into hepatocytes is a complex process that involves numerous cellular factors, including the scavenger receptor class B type 1 (SR-B1), the tetraspanin CD81, and the tight junction (TJ) proteins claudin-1 (CLDN1) and occludin (OCLN). Despite expression of all known HCV-entry factors, in vitro models based on hepatoma cell lines do not fully reproduce the in vivo susceptibility of liver cells to primary HCV isolates, implying the existence of additional host factors which are critical for HCV entry and/or replication. Likewise, HCV replication is severely impaired within hepatocellular carcinoma (HCC) tissue in vivo, but the mechanisms responsible for this restriction are presently unknown. Here, we identify tumor-associated calcium signal transducer 2 (TACSTD2), one of the most downregulated genes in primary HCC tissue, as a host factor that interacts with CLDN1 and OCLN and regulates their cellular localization. TACSTD2 gene silencing disrupts the typical linear distribution of CLDN1 and OCLN along the cellular membrane in both hepatoma cells and primary human hepatocytes, recapitulating the pattern observed in vivo in primary HCC tissue. Mechanistic studies suggest that TACSTD2 is involved in the phosphorylation of CLDN1 and OCLN, which is required for their proper cellular localization. Silencing of TACSTD2 dramatically inhibits HCV infection with a pan-genotype effect that occurs at the level of viral entry. Our study identifies TACSTD2 as a novel regulator of two major HCV-entry factors, CLDN1 and OCLN, which is strongly downregulated in malignant hepatocytes. These results provide new insights into the complex process of HCV entry into hepatocytes and may assist in the development of more efficient cellular systems for HCV propagation in vitro.

Contour recognition of complex leaf shapes

The leaf shape is an important taxonomic character. Compared to the classic morphological leaf features such as veins, margin indentations, sinuses, etc., the shape is simpler to obtain by using the 'magic wand' or other contouring tools that are available in most of imaging applications. The only exception is when leaves develop large lobes that get in touch or overlap each other, as the presence of hidden or closed portions of the leaf border precludes the application of automatic methods and forces the leaf contour to be traced manually. This is a time consuming and relatively accurate operation that, nevertheless, can not be avoided, as overlapping lobes are characteristic features of the leaves of several plant species and varieties. The method described in the paper overcomes this problem as it allows the leaf contour to be achieved even in the presence of touching or overlapping lobes. The method involves three steps: (1) the acquisition of leaf images using a transilluminator, (2) a two-level image segmentation that allows all leaf components (blade, overlapping lobes and closed sinuses) to be represented in a single binary image, and (3) the contouring and concatenation of all binary outlines in a single, self-intersecting closed contour that reproduces accurately the leaf shape. The method can be extended to acquire the shape of leaves of herbarium specimens, that are often overlapped but can not be easily handled and repositioned because of their extreme fragility and relevant taxonomic value.

Vegetative propagation of Plukenetia polyadenia by cuttings: effects of leaf area and indole-3-butyric acid concentration

The seeds of Plukenetia polyadenia have high levels of unsaturated fatty acids and are used as medicine and food for native people in the Peruvian and Brazilian Amazon. The objective of this study was to develop a method for vegetative propagation of Plukenetia polyadenia by rooting of cuttings. The experiment was laid out in a randomized complete block design with 12 treatments and 3 replications of 8 cuttings, in a 3 × 4 factorial arrangement. The factors were: 3 levels of leaf area (25, 50 and 75%) and 3 indole-3-butyric acid - IBA concentrations (9.84, 19.68 and 29.52mM) and a control without IBA. Data were submitted to analysis of variance and means were compared by Tukey test at 5% probability. Our results show that the use of cuttings with 50% of leaf area and treatment with 29.52mM of IBA induced high percentages of rooting (93%) and the best root formation. Vegetative propagation of Plukenetia polyadenia by cuttings will be used as a tool to conserve and propagate germplasm in breeding programs.

Integrated ordination of miRNA and mRNA expression profiles

Background

Several studies have investigated miRNA and mRNA co-expression to identify regulatory networks at the transcriptional level. A typical finding of these studies is the presence of both negative and positive miRNA-mRNA correlations. Negative correlations are consistent with the expected, faster degradation of target mRNAs, whereas positive correlations denote the existence of feed-forward regulations mediated by transcription factors. Both mechanisms have been characterized at the molecular level, although comprehensive methods to represent miRNA-mRNA correlations are lacking. At present, genome-wide studies are able to assess the expression of more than 1000 mature miRNAs and more than 35,000 well-characterized human genes. Even if studies are generally restricted to a small subset of genes differentially expressed in specific diseases or experimental conditions, the number of potential correlations remains very high, and needs robust multivariate methods to be conveniently summarized by a small set of data.

Results

Nonparametric Kendall correlations were calculated between miRNAs and mRNAs differentially expressed in livers of patients with acute liver failure (ALF) using normal livers as controls. Spurious correlations due to the histopathological composition of samples were removed by partial correlations. Correlations were then transformed into distances and processed by multidimensional scaling (MDS) to map the miRNA and mRNA relationships. These showed: (a) a prominent displacement of miRNA and mRNA clusters in ALF livers, as compared to control livers, indicative of gene expression dysregulation; (b) a clustering of mRNAs consistent with their functional annotations [CYP450, transcription factors, complement, proliferation, HLA class II, monocytes/macrophages, T cells, T-NK cells and B cells], as well as a clustering of miRNAs with the same seed sequence; and (c) a tendency of miRNAs and mRNAs to populate distinct regions of the MDS plot. MDS also allowed to visualize the network of miRNA-mRNA target pairs.

Conclusions

Different features of miRNA and mRNA relationships can be represented as thematic maps within the framework of MDS obtained from pairwise correlations. The symmetric distribution of positive and negative correlations between miRNA and mRNA expression suggests that miRNAs are involved in a complex bidirectional molecular network, including, but not limited to, the inhibitory regulation of miRNA targets.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1971-9) contains supplementary material, which is available to authorized users.

Primary Graft Dysfunction After Zero-Mismatch Kidney Transplantation Secondary to Early Biopsy-Proven Acute Cell-Mediated Rejection: Case Report

We report a case of primary renal allograft dysfunction and early acute cell-mediated rejection after a 12/12 HLA antigen zero-mismatch (0MM) transplant. The recipient was a 40-year-old white man who was highly allosensitized, with a calculated panel reactive antibody score of 100%. In posteroperative day 1 the recipient remained anuric and underwent dialysis because of hyperkalemia. Graft biopsy showed early acute cellular rejection, Banff grade 2B. No evidence of antibody-mediated rejection was observed. To our knowledge, this case is the 1st to report early cell-mediated rejection after 12/12 HLA antigen 0MM kidney transplantation. This case suggests that highly sensitized candidates are at high immunologic risk even in the context of 0MM kidney transplantation.

A Landscape Analysis to Understand Orientation of Honey Bee (Hymenoptera: Apidae) Drones in Puerto Rico

Honey bees [Apis mellifera L. (Apidae, Hymenoptera)] show spatial learning behavior or orientation, in which animals make use of structured home ranges for their daily activities. Worker (female) orientation has been studied more extensively than drone (male) orientation. Given the extensive and large flight range of drones as part of their reproductive biology, the study of drone orientation may provide new insight on landscape features important for orientation. We report the return rate and orientation of drones released at three distances (1, 2, and 4 km) and at the four cardinal points from an apiary located in Gurabo, Puerto Rico. We used high-resolution aerial photographs to describe landscape characteristics at the releasing sites and at the apiary. Analyses of variance were used to test significance among returning times from different distances and directions. A principal components analysis was used to describe the landscape at the releasing sites and generalized linear models were used to identify landscape characteristics that influenced the returning times of drones. Our results showed for the first time that drones are able to return from as far as 4 km from the colony. Distance to drone congregation area, orientation, and tree lines were the most important landscape characteristics influencing drone return rate. We discuss the role of landscape in drone orientation.

Association of G1359A polymorphism of the cannabinoid receptor gene (CNR1) with macronutrient intakes in obese females

BACKGROUND

The endogenous cannabinoid system plays a role in metabolic aspects of body weight and feeding behaviour. A polymorphism (1359 G/A) (rs1049353) of the CB1 gene was reported as a common polymorphism in the Caucasian population. The present study aimed to investigate the association of the polymorphism (G1359A) of the CB1 receptor gene on macronutrient intake in females with obesity.

METHODS

A sample of 896 females was analysed. A bioimpedance measurement, a blood pressure measurement, a serial assessment of nutritional intake with 3 days of written food records, and a biochemical analysis were all performed. The genotype of the CNR1 receptor gene polymorphism (rs1049353) was studied.

RESULTS

Five hundred and sixteen patients (57.6%) had the genotype G1359G (non-A carriers) and 380 (42.4%) patients had G1359A (328 patients, 36.6%) or A1359A (52 patients, 5.8%) (A carriers). Triglycerides and high-density lipoprotein (HDL) cholesterol levels were higher in A non-A allele carriers than non-A allele carriers. The intakes of dietary cholesterol and saturated fat for the upper tertile (T3) compared to the baseline tertile were inversely associated with the CB1-R 1359 G/A polymorphism [odds ratio (OR) = 0.59; 95% confidence interval (CI) = 0.30-0.92 and OR = 0.66; 95% CI = 0.39-0.91, respectively]. These data were observed in the second tertile (T2) (OR = 0.61; 95% CI = 0.29-0.94 and OR = 0.58; 95% CI = 0.31-0.90, respectively).

CONCLUSIONS

The present study reports an association of the A allele with a better lipid profile (triglycerides and HDL cholesterol) than non-A allele carriers. In addition, this polymorphism is associated with a specific macronutrient intake, as well as with low cholesterol and fat saturated intakes.

Viral expression and molecular profiling in liver tissue versus microdissected hepatocytes in hepatitis B virus-associated hepatocellular carcinoma

Background

The molecular mechanisms whereby hepatitis B virus (HBV) induces hepatocellular carcinoma (HCC) remain elusive. We used genomic and molecular techniques to investigate host-virus interactions by studying multiple areas of the same liver from patients with HCC.

Methods

We compared the gene signature of whole liver tissue (WLT) versus laser capture-microdissected (LCM) hepatocytes along with the intrahepatic expression of HBV. Gene expression profiling was performed on up to 17 WLT specimens obtained at various distances from the tumor center from individual livers of 11 patients with HCC and on selected LCM samples. HBV markers in liver and serum were determined by real-time polymerase chain reaction (PCR) and confocal immunofluorescence.

Results

Analysis of 5 areas of the liver showed a sharp change in gene expression between the immediate perilesional area and tumor periphery that correlated with a significant decrease in the intrahepatic expression of HB surface antigen (HBsAg). The tumor was characterized by a large preponderance of down-regulated genes, mostly involved in the metabolism of lipids and fatty acids, glucose, amino acids and drugs, with down-regulation of pathways involved in the activation of PXR/RXR and PPARα/RXRα nuclear receptors, comprising PGC-1α and FOXO1, two key regulators critically involved not only in the metabolic functions of the liver but also in the life cycle of HBV, acting as essential transcription factors for viral gene expression. These findings were confirmed by gene expression of microdissected hepatocytes. Moreover, LCM of malignant hepatocytes also revealed up-regulation of unique genes associated with cancer and signaling pathways, including two novel HCC-associated cancer testis antigen genes, NUF2 and TTK.

Conclusions

Integrated gene expression profiling of whole liver tissue with that of microdissected hepatocytes demonstrated that HBV-associated HCC is characterized by a metabolism switch-off and by a significant reduction in HBsAg. LCM proved to be a critical tool to validate gene signatures associated with HCC and to identify genes that may play a role in hepatocarcinogenesis, opening new perspectives for the discovery of novel diagnostic markers and therapeutic targets.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-014-0230-1) contains supplementary material, which is available to authorized users.

Identification of microRNAs specifically expressed in hepatitis C virus-associated hepatocellular carcinoma

Although several studies have investigated the association of miRNAs with hepatocellular carcinoma (HCC), the data published so far are not concordant. A reason for these discrepancies may be the fact that most studies used the nontumorous tissue surrounding the HCC lesion as a control, which is almost invariably affected by cirrhosis or chronic hepatitis, as well as other pathological conditions such as hepatitis B virus (HBV) or hepatitis C virus (HCV) infection. Moreover, HCC is often analyzed as a single group regardless of the different viral etiologies. The miRNAs differentially expressed in HCV-related HCC were investigated by comparing the tumorous tissues to a wide range of liver specimens, including healthy livers obtained from liver donors and patients who underwent liver resection for angioma, in addition to tissues from various acute and chronic liver diseases, including HCV-related cirrhosis not associated with HCC, HCV-related cirrhosis associated with HCC and HBV-associated acute liver failure. The whole set of 2,226 human miRNAs were examined, including 1,121 pre-miRNAs and 1,105 mature miRNAs, available in a microarray platform. Stringent statistical methods were applied to reduce the risk of false discoveries to less than 1%. These data identified 18 miRNAs exclusively expressed in HCV-associated HCC, characterized by high specificity and selectivity versus all other liver diseases and healthy conditions and connected into a regulatory network pivoting on p53, phosphatase and tensin homolog and all-trans retinoic acid signaling.

Decompressive craniectomy and brain death prevalence and mortality: 8-year retrospective review

Decompressive craniectomy (DC) is a surgical practice that has been used since the late 19th century. The cerebral blood flow increase after the performance of a DC can delay and even prevent the development of cerebral circulatory arrest and brain death (BD). We aimed to determine the prevalence of BD, the use of DC, and the evolution to BD with versus without DC. This retrospective, observational, cross-sectional study was performed in a single high-intensity center in Argentina from January 2003 to December 2010. Inclusion criteria were all patients with Glasgow Coma Score of at most 7 on admission or during their stay in the intensive care units. Exclusion criteria were patients with incomplete data. In cases of death, we assessed whether they fulfilled BD criteria or if the cause of death was a cardiac arrest (CA). The 698 patients considered for analysis showed a 60% (n = 418) global mortality rate. The causes were: CA (n = 270); BD (n = 108) and others considered to be "undefined," namely not assessed completely for the diagnosis of BD (n = 40). According to diagnosis category, traumatic brain injury (TBI) was largest (nearly 50%). The DC group (n = 206) showed significant differences regarding sex and diagnosis category versus no DC group. Mortality was significantly lower in this group (48% versus 65%, P < .001). No significant differences were observed comparing causes of death (CA, BD, or undefined). The use of DC did not influence the frequency of BD development (24% versus 26%, P = .72). The average DC rate was 30% and of BD 16%. The prevalence of DC and better survival were recorded compared with subjects without DC. The prevalence of BD was lower than expected in accordance with national registries; however, among our group, DC did not seem to modify the evolution to BD.

Liver regeneration signature in hepatitis B virus (HBV)-associated acute liver failure identified by gene expression profiling

Introduction

The liver has inherent regenerative capacity via mitotic division of mature hepatocytes or, when the hepatic loss is massive or hepatocyte proliferation is impaired, through activation of hepatic stem/progenitor cells (HSPC). The dramatic clinical course of acute liver failure (ALF) has posed major limitations to investigating the molecular mechanisms of liver regeneration and the role of HSPC in this setting. We investigated the molecular mechanisms of liver regeneration in 4 patients who underwent liver transplantation for hepatitis B virus (HBV)-associated ALF.

Methods and Findings

Gene expression profiling of 17 liver specimens from the 4 ALF cases and individual specimens from 10 liver donors documented a distinct gene signature for ALF. However, unsupervised multidimensional scaling and hierarchical clustering identified two clusters of ALF that segregated according to histopathological severity massive hepatic necrosis (MHN; 2 patients) and submassive hepatic necrosis (SHN; 2 patients). We found that ALF is characterized by a strong HSPC gene signature, along with ductular reaction, both of which are more prominent in MHN. Interestingly, no evidence of further lineage differentiation was seen in MHN, whereas in SHN we detected cells with hepatocyte-like morphology. Strikingly, ALF was associated with a strong tumorigenesis gene signature. MHN had the greatest upregulation of stem cell genes (EpCAM, CK19, CK7), whereas the most up-regulated genes in SHN were related to cellular growth and proliferation. The extent of liver necrosis correlated with an overriding fibrogenesis gene signature, reflecting the wound-healing process.

Conclusion

Our data provide evidence for a distinct gene signature in HBV-associated ALF whose intensity is directly correlated with the histopathological severity. HSPC activation and fibrogenesis positively correlated with the extent of liver necrosis. Moreover, we detected a tumorigenesis gene signature in ALF, emphasizing the close relationship between liver regeneration and liver cancer.

Protein C activity and postoperative metabolic liver function after liver transplantation

BACKGROUND

Protein C is a natural thrombin antagonist produced by hepatocytes. Its levels are low in liver failure and predispose patients to increased risk for thrombosis. Little is known about the relationship between protein C activity and hepatic function after orthotopic liver transplantation (OLT).

METHODS

We measured protein C activity of 41 patients undergoing liver transplantation by the Staclot method (normal range, 70%-130%) preoperatively and then daily on postoperative days (POD) 0-5.

RESULTS

The mean protein C activity was low before OLT (34.3 ± 4.3%) and inversely correlated with the preoperative Model for End-Stage Liver Disease score (Spearman's r = -0.643; P < .0001). Mean activity increased significantly on POD 1 (58.9 ± 4.5%), and remained above preoperative levels through POD 5. Ten patients developed metabolic liver dysfunction defined by a serum total bilirubin >5 mg/dL on POD 7. These patients had significantly lower protein C activity from POD 3 (47.2 ± 9.6% vs 75.9 ± 5.8%; P = .01) to POD 5. Preoperative protein C activity correlated inversely with the severity of liver failure as indicated by preoperative MELD score.

CONCLUSION

Protein C activity recovered rapidly in patients with good allograft function but remained significantly lower in patients who had limited metabolic function as evidenced by increased total bilirubin levels.

A lipoprotein source of cholesteryl esters is essential for proliferation of CEM-CCRF lymphoblastic cell line

Tumour are characterised by a high content of cholesteryl esters (CEs) stored in lipid droplets purported to be due to a high rate of intracellular esterification of cholesterol. To verify whether and which pathways involved in CE accumulation are essential in tumour proliferation, the effect of CE deprivation, from both exogenous and endogenous sources, on CEM-CCRF cells was investigated. Cholesterol synthesis, esterification and content, low-density lipoprotein (LDL) binding and high-density lipoprotein (HDL)-CE uptake were evaluated in cultured in both conventional and delipidated bovine serum with or without oleic or linoleic acids, cholesteryl oleate, LDL and HDL. High content of CEs in lipid droplets in this cell line was due to esterification of both newly synthesised cholesterol and that obtained from hydrolysis of LDL; moreover, a significant amount of CE was derived from HDL-CE uptake. Cell proliferation was slightly affected by either acute or chronic treatment up to 400 μM with Sz-58035, an acyl-cholesteryl cholesterol esterification inhibitor (ACAT); although when the enzyme activity was continuously inhibited, CE content in lipid droplets was significantly higher than those in control cells. In these cells, analysis of intracellular and medium CEs revealed a profile reflecting the characteristics of bovine serum, suggesting a plasma origin of CE molecules. Cell proliferation arrest in delipidated medium was almost completely prevented in the first 72 h by LDL or HDL, although in subsequent cultures with LDL, it manifested an increasing mortality rate. This study suggests that high content of CEs in CEM-CCRF is mainly derived from plasma lipoproteins and that part of CEs stored in lipid droplets are obtained after being taken up from HDL. This route appears to be up-regulated according to cell requirements and involved in low levels of c-HDL during cancer. Moreover, the dependence of tumour cells on a source of lipoprotein provides a novel impetus in developing therapeutic strategies for use in the treatment of some tumours.

Neutralizing antibodies to hepatitis C virus in perinatally infected children followed up prospectively

Little is known about the presence and role of neutralizing antibodies (NtAbs) in perinatal hepatitis C virus (HCV) infection. Using HCV pseudoparticles, NtAbs were studied longitudinally in 12 HCV-infected children with or without evidence of acute hepatitis during the first year of life. Broadly reactive NtAbs of maternal origin did not prevent vertical HCV transmission or progression to chronicity. NtAbs against homologous genotype or subtype appeared during the chronic phase and were more abundant and sustained in children with acute hepatitis. Cross-reactive NtAbs were present in both groups of children, but their appearance did not correlate with better control of viremia or HCV clearance.

Cigarette smoking and appendectomy: effect on clinical course of diverticulosis

AIM

To investigate the effect of appendectomy and cigarette smoking on the clinical course of diverticulosis.

MATERIALS AND METHODS

A retrospective case-control study of 207 consecutive patients (45.8% male mean age 64.0 years), 150 with asymptomatic diverticulosis, and 57 with acute diverticulitis. Diagnosis of diverticulosis was defined on the basis of clinical and colonoscopic criteria, diverticulitis was defined by means of clinical, colonoscopic and computerised tomography criteria. Logistic regression function was used to define the relationship between the dependent variable (diverticulitis) and several covariates: sex, age, body mass index, smoking habit, and history of appendectomy.

RESULTS

According to the final model, the risk of diverticulitis was 4.94-fold higher (95% confidence interval: 1.98-12.37) in patients with a history of appendectomy with emergency resection, compared to patients not submitted to appendectomy or with a history of elective resection (P < 0.001); and 2.79-fold higher (95% confidence interval: 1.30-5.96) in smokers than in non-smokers (P = 0.008). The effects of the two determinants were found to be independent, thus the cumulative risk of diverticulitis was 13.78-fold higher for smokers with a history of emergency surgical treatment.

CONCLUSION

Smoking and emergency appendectomy are important predictive factors for the clinical course of diverticulosis.

Altered cholesterol ester cycle in skin fibroblasts from patients with Alzheimer's disease

Intracellular cholesterol metabolism was reported to modulate amyloid-beta (Abeta) generation in Alzheimer's disease (AD). Results presented herein demonstrated that, like brain cells, cultured skin fibroblasts from AD patients contained more cholesterol esters than fibroblasts from healthy subjects. Particularly, Oil Red-O, Nile Red, and filipin staining highlighted higher levels of neutral lipids which responded to inhibitors of acyl-coenzyme A:cholesterol acyl-transferase (ACAT-1), associated with an increase in free cholesterol. ACAT-1 mRNA levels increased significantly in AD fibroblasts, whereas those of sterol regulatory element binding protein-2, neutral cholesterol ester hydrolase, and ATP-binding cassette transporter member 1 were markedly down-regulated. Instead, mRNA levels of low-density lipoprotein receptor, hydroxy-methyl-glutaryl-coenzyme A reductase, caveolin-1, and amyloid-beta protein precursor (AbetaPP) were virtually unchanged. Notably, mRNA levels of both beta-site AbetaPP-cleaving enzyme 1 (BACE1) and neprilysin were significantly down-regulated. An increase in Abeta(40) and Abeta(42) immunostaining and a decrease in BACE1 active form were also found in AD versus control fibroblasts. Altogether, these findings support the hypothesis that the derangement of cholesterol homeostasis is a systemic alteration involving central but also peripheral cells of AD patients, and point to cholesterol ester levels in AD fibroblasts as an additional metabolic hallmark useful in the laboratory and clinical practice.

SERS and theoretical studies of arginine

Arginine amino acid (Arg) has been vibrationally studied through its infrared, Raman and surface-enhanced Raman scattering (SERS) spectra, and theoretical calculations. Net charge is used to predict the possibility to obtain the SERS spectrum of Arg in colloidal solution. The interpretation of the SERS spectral data suggests that the Arg-Ag nanoparticles interaction in a colloidal solution and in the case of the Arg coated by Ag is mainly verified through the guanidinium moiety. Theoretical calculations performed by using extended Hückel theory method for a model of Arg interacting with an Ag cluster support the observed SERS experimental result.

Multiresidue mycotoxin analysis in wheat, barley, oats, rye and maize grain by high-performance liquid chromatography-tandem mass spectrometry

A method has been developed for the simultaneous analysis of 22 mycotoxins in wheat, barley, oats, rye and maize grain. Analysis is carried out with liquid chromatography-electrospray ionisation tandem mass spectrometry. The compounds included in this analysis are aflatoxins, sterigmatocystin, cyclopiazonic acid, tricothecenes, ochratoxin A, fumonisins, zearalonone, and ergot alkaloids. Sample extraction (2 g) with acetonitrile:water (8 ml, 80:20) was carried out for 2 min using a commercial sample preparation apparatus (Stomacher®). The extract was then centrifuged, filtered and analysed. Extraction of fumonisins from maize (2 g) was optimised by first extracting the maize with acetonitrile: water (5 ml, 80:20) followed by the addition of water (3 ml), which permitted extraction of the 22 mycotoxins, including the fumonisins. Chromatography was carried out with a minicolumn (7.5×2.1 mm, 5 µm) (5 µl sample injection) and in 11 min, including column reconditioning. Analysis was carried out with 2 MRM transitions for the precursor ions. All method detection limits were below current maximum Canadian residue limits. Matrix effects for each compound in each of the 5 matrices were estimated and ranged from 70 to 149%, but most were 100±10%. Accuracy, repeatability and ruggedness were established. Proficiency samples from FERA (Food and Environment Research Agency, Sand Hutton, York, UK) were tested and are reported. Finally, 100 field samples of the various grains were tested with this method and are reported with the observation of numerous mycotoxins in all matrices, including ergotamine in winter wheat.

Nanoparticles from lipid-based liquid crystals: emulsifier influence on morphology and cytotoxicity

Here, monoolein-based nanoparticles (NPs), obtained through fragmentation of bulk liquid crystalline phases, and stabilized by two different emulsifiers, namely, Pluronic F127 (PF127) and lauroylcholine chloride (LCh), are investigated for structural features and for short-term in vitro cytotoxicity. Depending on the emulsifiers, different morphologies of the lipid NPs (cubosomes and liposomes) are obtained, as demonstrated by cryo-TEM images. Although NPs offer many advantages in medical applications and various chemicals used for their preparation are under investigation, so far there are no standardized procedures to evaluate cell biocompatibility. Two different protocols to evaluate the impact of these lipid NPs on biological systems are presented. Results show that nanoparticles stabilized by PF127 (cubosomes) display a relevant toxicity toward different cell lines, whereas those stabilized by LCh (liposomes) affect cell viability at a much lesser extent.

Glucose-6-phosphate-dehydrogenase deficiency as a risk factor for pterygium

PURPOSE

Glucose-6-phosphate dehydrogenase (G6PD) is an important site of metabolic control in the pentose phosphate pathway (PPP), providing reducing power (NADPH) and pentose phosphates. The purpose of this study was to investigate the possible involvement of G6PD deficiency (G6PD-) in the pathogenesis of pterygium.

METHODS

Erythrocyte G6PD activity was evaluated in 123 pterygium patients and in 112 age-matched control patients. Enzyme activity, mRNA, rate of growth, green autofluorescence, response to oxidative stress, and cholesterol metabolism were determined in pterygium fibroblasts (PFs) and in normal conjunctival fibroblasts (NCFs) isolated from G6PD normal (NCFs+ and PFs+) and G6PD- (NCFs- and PFs-) patients.

RESULTS

Higher prevalence of G6PD- was found in patients affected by primary pterygium than in control subjects, both men and women, suggesting that this enzymatic defect may be a predisposing factor for pterygium. G6PD activity was significantly lower in NCFs- than in NCFs+, but not in PFs- than in PFs+. In PFs-, G6PD mRNA levels were significantly higher than in PFs+. Growth-stimulated NCFs- grew at half the rate of NCFs+, although PFs- and PFs+ grew at the same rate. Increased green autofluorescence and susceptibility to oxidative stress were observed in PFs (+/-) and in NCFs-, but not in NCFs+. Moreover, ex vivo PFs (+/-) accumulated more lipids than corresponding NCFs.

CONCLUSIONS

The results of this study, although restricted to a limited group of subjects (i.e., those of Sardinian ancestry), suggest that G6PD- not only does not protect against pterygium, but may even be considered a risk factor for the development of this disorder.

Stability of cyclopiazonic acid in solution

Cyclopiazonic acid (CPA) is an important mycotoxin given its toxicity and prevalence in foods and feeds. There is tremendous interest in developing analytical methods that include CPA as part of a multi-residue mycotoxin routine, but there appears to be considerable difficulty in analysing it using liquid chromatography with electrospray ionisation tandem mass spectrometry (LC-MS/MS). During the development of a multi-residue method for mycotoxins including CPA, a number of issues were discovered under routine and common analytical conditions that have an impact on the determination of CPA, including: (1) at the ng/ml level CPA reacts with ambient oxygen from the headspace of the vial, an effect that decreases its concentration linearly; (2) CPA readily adsorbs to plastic in a reversible fashion; (3) CPA is acid hydrolysed with formic acid; (4) CPA reacts with the column stationary phase affecting chromatographic parameters; and (5) CPA presents significant carry-over issues. In an effort to find solutions to these problems we found that CPA can be protected from reacting with oxygen by adding 1 µg/ml ascorbic acid and that its carry-over can be reduced to a negligible level by injecting ammonia between injections of solutions containing CPA, even with formic acid in the mobile phase. Chromatographic conditions for CPA have been optimised in consideration of all of the aforementioned concerns.

Accumulation of neutral lipids in peripheral blood mononuclear cells as a distinctive trait of Alzheimer patients and asymptomatic subjects at risk of disease

BACKGROUND

Alzheimer's disease is the most common progressive neurodegenerative disease. In recent years, numerous progresses in the discovery of novel Alzheimer's disease molecular biomarkers in brain as well as in biological fluids have been made. Among them, those involving lipid metabolism are emerging as potential candidates. In particular, an accumulation of neutral lipids was recently found by us in skin fibroblasts from Alzheimer's disease patients. Therefore, with the aim to assess whether peripheral alterations in cholesterol homeostasis might be relevant in Alzheimer's disease development and progression, in the present study we analyzed lipid metabolism in plasma and peripheral blood mononuclear cells from Alzheimer's disease patients and from their first-degree relatives.

METHODS

Blood samples were obtained from 93 patients with probable Alzheimer's disease and from 91 of their first-degree relatives. As controls we utilized 57, cognitively normal, over-65 year-old volunteers and 113 blood donors aged 21-66 years, respectively. Data are reported as mean +/- standard error. Statistical calculations were performed using the statistical analysis software Origin 8.0 version. Data analysis was done using the Student t-test and the Pearson test.

RESULTS

Data reported here show high neutral lipid levels and increased ACAT-1 protein in about 85% of peripheral blood mononuclear cells freshly isolated (ex vivo) from patients with probable sporadic Alzheimer's disease compared to about 7% of cognitively normal age-matched controls. A significant reduction in high density lipoprotein-cholesterol levels in plasma from Alzheimer's disease blood samples was also observed. Additionally, correlation analyses reveal a negative correlation between high density lipoprotein-cholesterol and cognitive capacity, as determined by Mini Mental State Examination, as well as between high density lipoprotein-cholesterol and neutral lipid accumulation. We observed great variability in the neutral lipid-peripheral blood mononuclear cells data and in plasma lipid analysis of the subjects enrolled as Alzheimer's disease-first-degree relatives. However, about 30% of them tend to display a peripheral metabolic cholesterol pattern similar to that exhibited by Alzheimer's disease patients.

CONCLUSION

We suggest that neutral lipid-peripheral blood mononuclear cells and plasma high density lipoprotein-cholesterol determinations might be of interest to outline a distinctive metabolic profile applying to both Alzheimer's disease patients and asymptomatic subjects at higher risk of disease.

Prevalence of Aspergillus species on selected Colombian animal feedstuffs and ability of Aspergillus section Flavi to produce aflatoxins

A total of 57 samples of feedstuffs commonly used for animal nutrition in Colombia (maize, soybean, sorghum, cottonseed meal, sunflower seed meal, wheat middlings and rice) were analysed for Aspergillus contamination. Aspergillus fungi were identified at species level and their ability to produce aflatoxins was determined by highperformance liquid chromatography. A total of 31 of the feedstuffs analysed (54.4%) were found to contain Aspergillus spp. The most contaminated substrate was maize (100%) followed by cottonseed meal (80%), sorghum (60%) and wheat middlings (60%). Soybean showed lower levels of contamination (10%). No Aspergillus spp. could be isolated from rice or sunflower seed meal. Total Aspergillus strains isolated were 50, with 28 belonging to section Flavi (56%), 17 to section Nigri (34%), 4 to section Circumdati (8%) and 1 to section Fumigati (2%). Among section Flavi, 17 isolates were identified as A. flavus, seven as A. parasiticus, two as A. oryzae and two as A. tamarii. Production of aflatoxins by Aspergillus section Flavi was screened by liquid chromatography. About three quarters of the A. flavus strains (76.5%) produced aflatoxin B1 (0.2 to 240.4 µg/g) and aflatoxin B2 (0.2 to 1.6 µg/g), while all A. parasiticus strains produced the four naturally occurring aflatoxins (aflatoxin B1 from 0.6 to 83.5 µg/g, aflatoxin B2 from 0.3 to 4.8 µg/g, aflatoxin G1 from 0.4 to 19.3 µg/g and aflatoxin G2 from 0.1 to 1.0 µg/g). This is the first study demonstrating the presence of highly toxigenic Aspergillus fungi in Colombian animal feedstuffs.

Lipid droplet changes in proliferating and quiescent 3T3 fibroblasts

Lipid droplets (LDs) are fat-storing organelles present in virtually all eukaryotic cells and involved in many aspects of cell biology related to lipid metabolism and cholesterol homeostasis. In this study, we investigated the presence of LDs in proliferating and quiescent (contact-inhibited) 3T3 fibroblasts to verify a correlation with cell growth. LDs were characterized by Nile red staining, positivity to adipophilin and negativity to perilipin. LDs were numerous in proliferating cells, but very few in quiescent cells. However, the fraction of quiescent cells, which resumed proliferation after scratch-wound assay, also resumed the formation of LDs. In proliferating cells, the number of LDs correlated with the DNA content, suggesting a continuous accumulation of LDs during cell growth. These findings were supported by biochemical data showing much higher rates of cholesterol esterification and triglyceride synthesis in proliferating cells. Both filipin staining and the fluorescent cholesterol analog dehydroergosterol revealed the presence of an intense traffic of free cholesterol, mediated by acidic vesicles, in proliferating cells. Nile red ratiometric measurements revealed a different lipid composition of LDs in proliferating and quiescent cells. Changes in the number and composition of LDs were also found in growing cells treated with inhibitors of cholesterol esterification (Sandoz 58-035), endosomal cholesterol efflux (U18666A) and V-ATPase (bafilomycin-A1).