170 research outputs found

    Purification and characterization of a novel human 15 kd cholesterol crystallization inhibitor protein in bile

    Get PDF
    Crystallization-inhibiting proteins can explain longer nucleation times associated with bile from gallstone-free subjects as compared with bile from patients with cholesterol gallstones. We partially characterized and examined the crystallization inhibitory potency of a newly purified 15 kd human biliary protein. Gallbladder bile was passed through an anti-apolipoprotein A-I (apo A-I) immunoaffinity column to extract lipid-associaied proteins. The bound fraction was separated by 30 kd ultrafiltration. Sodium dodecyl sulfate-polyacrylamide gel electrophesis (SDS-PAGE) was performed under nonreducing and reducing conditions. Cholesterol crystallization activity was tested in a photometric cholesterol crystal growth assay. Isoelectric focusing was performed by using a standard gel, The purified 15 kd protein was subjected to N-terminal amino acid sequencing, Although the whole apo A-I-bound fraction contained a variety of proteins and lipids, its 30 kd filtrate yielded a nearly pure 15 kd protein with only minor contamination from apo A-I. Amino acid sequencing showed that the protein was unique. Enzymatic deglycosylation revealed no evidence for glycosylation. At a protein concentration of 10 mu g/ml, crystallization time was delayed as compared with control and apo A-I, and final crystal mass was reduced to 75% of control, Its isoelectric point was 6.1 without isoforms, Under nonreducing conditions, the protein formed a 30 kd dimer and a 60 kd tetramer. We conclude that this protein is a novel potent biliary crystallization inhibitor protein

    BILIARY HAPTOGLOBIN, A POTENT PROMOTER OF CHOLESTEROL CRYSTALLIZATION AT PHYSIOLOGICAL CONCENTRATIONS

    Get PDF
    Background/Aims: Several proteins present in human bile have been reported to promote cholesterol crystallization and thus are potentially important in the formation of cholesterol crystals as the initial stage in gallstone pathogenesis. To be physiologically relevant, such proteins must either be present in high concentration in bile or have a potent promoting activity. The current study explored several of the more abundant but unexamined biliary proteins based upon their also having sufficiently high serum concentrations that antibodies were available for both their isolation and quantitation. Methods: Protein purification was accomplished by immunoaffinity chromatography of bile followed by delipidation. Con A affinity chromatography of bile was used to obtain the bound fraction, a portion of which was delipidated. Crystallization-promoting activity of both the purified proteins and Con A-bound glycoprotein fractions (CABG) was measured by a photometric crystal growth assay. A competitive antibody-capture ELISA assay was developed to measure concentrations of alpha(1)-antitrypsin, transferrin, and haptoglobin in native bile. Results: At their relevant physiological concentrations, biliary haptoglobin (15 mu g/ml) had a crystallization-promoting activity twice that of the biliary IgM (75 mu g/ml) used as a reference standard (P < 0.05). Biliary transferrin (20 mu g/ml) had only modest promoting activity (P < 0.05). Biliary alpha(1)-antitrypsin (50 mu g/ml), by contrast, showed no promoting activity. Delipidation of the CABG fraction decreased its promoting activity by 75%. Biliary haptoglobin accounts for about 30% of delipidated total CABG-promoting activity. Conclusions: Biliary haptoglobin at its physiological concentration has a highly potent crystallization-promoting activity and thus becomes a candidate for major attention in understanding gallstone pathogenesis. Biliary lipids associated with CABG account for a major portion of the cholesterol-crystallization-promoting activity of this fraction

    Proposal of A New Bois Noir Epidemiological Pattern Related to &#8216;Candidatus Phytoplasma Solani&#8217; Strains Characterized by A Possible Moderate Virulence in Tuscany

    Get PDF
    Bois noir (BN), associated with 'Candidatus Phytoplasma solani' (CaPsol), is the most widespread disease of the grapevine yellows complex worldwide. In this work, BN epidemiology was investigated in a case study vineyard where an unusual CaPsol strain, previously detected only in other host plants, was found to be prevalent in grapevine. Experimental activities included: symptom observation; sampling of symptomatic vines, Auchenorrhyncha specimens, and weeds; molecular detection and typing of CaPsol strains; statistical analyses for determining possible relationships between CaPsol relative concentration, strain type, and symptom severity. Among insects, Reptalus quinquecostatus was the most abundant and was found to be highly infected by CaPsol, while Hyalesthes obsoletus, the main CaPsol vector, was not caught. Moreover, R. quinquecostatus harbored CaPsol strains carrying uniquely the stamp sequence variant St10, also identified as prevalent in vines and in the majority of weeds, and all the secY variants identified in the vineyard. Statistical analyses revealed that CaPsol strains carrying the St10 variant are not associated with severe symptoms, suggesting their possible moderate virulence. Based on such evidence, a new BN epidemiological pattern related to these CaPsol strains and involving grapevine, R. quinquecostatus, and/or weeds is proposed. Furthermore, the possible presence of other players (vectors and weeds) involved in CaPsol transmission to grapevines was highlighted

    Human gallbladder mucosal function : effects on intraluminal fluid and lipid composition in health and disease.

    Get PDF
    Abstract: Gallbladder mucosal absorption of fluid during fasting is a well-known process. Indirect in vivo and recent in vitro evidence for physiologically relevant gallbladder absorption of cholesterol and phospholipids from bile has been observed in humans. The present study explored and compared by indirect means the relative efficiences of human gallbladder mucosal absorption of fluid and lipids in health and disease. Biliary lipids and pigment content were measured in fasting gallbladder bile samples obtained from gallstone-free controls and from four study groups: multiple and solitary cholesterol gallstone patients, and morbidly obese subjects with and without gallstones. Bile salts and pigment content were significantly greater in gallstone-free controls than in all other disease study groups, This was interpreted as evidence of more effective gallbladder mucosal fluid absorption in nonobese gallstone-free controls compared to that in all other groups, Correlation plot analyses of biliary lipids showed lower concentrations of phospholipids than expected from the index bile salt concentrations, The same was found for cholesterol concentrations but only in supersaturated samples, These findings were much more pronounced in gallstone free-controls and were accordingly interpreted as evidence of more efficient gallbladder absorption of both phospholipids and cholesterol in controls compared with that found in each of the disease study groups, Moreover, impaired gallbladder mucosal function, while invariably associated with cholesterol gallstone disease, was not found to be a necessary consequence of the physical presence of stones. It is concluded that efficient gallbladder mucosal absorption of both fluid and apolar lipids from bile is a normal physiological process that is often seriously impaired in the presence of either cholesterol gallstone disease or at least one of its precursor forms

    Variations in pigment and carbohydrate content of gallbladder bile affect accurate quantitation of total protein when using the fluorescamine method

    Get PDF
    Background: Despite solute dilution and reduced total lipid concentrations, an unexplained increase in protein concentration has been reported to occur in the gallbladder bile of cholesterol gallstone patients. Methods: Solutes in gallbladder bile from gallstone-free controls and from four study groups were measured using standard methods. Total proteins were measured using amino acid analysis and a conventional fluorescamine method. Results: Bile salts and pigment content were greater in gallstone-free controls than in all other study groups, including morbidly obese gallstone-free subjects. Total biliary protein concentration, as determined by amino acid analysis in the gallstone-free control group was higher than in non-obese gallstone patients with multiple stones and in morbidly obese gallstone-free subjects. Total biliary proteins as measured with fluorescamine, however, did not show intergroup differences. A major problem of the conventional fluorescamine assay is shown to be an artefact arising from the high pigment content of the more concentrated samples. Conclusions: Very dilute gallbladder bile samples are often found in the presence of gallstone disease. This also occurs in morbidly obese subjects, even in the absence of gallstones. Although the contribution of protein secretion/absorption by the gallbladder can also be relevant, especially in the presence of morbid obesity, the protein concentration in gallbladder bile, when accurately measured, generally parallels the concentrations of non-absorbed biliary solutes, reflecting the efficiency of fluid absorption. Measurement of biliary proteins by the conventional fluorescamine method is unreliable in clinical studies in which intergroup differences in pigment content are commonly present

    Severity of Hepatocyte Damage and Prognosis in Cirrhotic Patients Correlate with Hepatocyte Magnesium Depletion

    Get PDF
    We aimed to evaluate the magnesium content in human cirrhotic liver and its correlation with serum AST levels, expression of hepatocellular injury, and MELDNa prognostic score. In liver biopsies obtained at liver transplantation, we measured the magnesium content in liver tissue in 27 cirrhotic patients (CIRs) and 16 deceased donors with healthy liver (CTRLs) by atomic absorption spectrometry and within hepatocytes of 15 CIRs using synchrotron-based X-ray fluorescence microscopy. In 31 CIRs and 10 CTRLs, we evaluated the immunohistochemical expression in hepatocytes of the transient receptor potential melastatin 7 (TRPM7), a magnesium influx chanzyme also involved in inflammation. CIRs showed a lower hepatic magnesium content (117.2 (IQR 110.5-132.9) vs. 162.8 (IQR 155.9-169.8) mu g/g; p &lt; 0.001) and a higher percentage of TRPM7 positive hepatocytes (53.0 (IQR 36.8-62.0) vs. 20.7 (10.7-32.8)%; p &lt; 0.001) than CTRLs. In CIRs, MELDNa and serum AST at transplant correlated: (a) inversely with the magnesium content both in liver tissue and hepatocytes; and (b) directly with the percentage of hepatocytes stained intensely for TRPM7. The latter also directly correlated with the worsening of MELDNa at transplant compared to waitlisting. Magnesium depletion and overexpression of its influx chanzyme TRPM7 in hepatocytes are associated with severity of hepatocyte injury and prognosis in cirrhosis. These data represent the pathophysiological basis for a possible beneficial effect of magnesium supplementation in cirrhotic patients

    Telemonitoring in chronic ventilatory failure: a new model of survellaince, a pilot study

    Get PDF
    Background and Aim. The efficiency of tele-monitoring or tele-assistance in patients with severe chronic ventilatory failure in home mechanical ventilation (HMV) is still being investigated. Our aim was to test the feasibility of a model which consisted in: 1) once a week nocturnal telemonitoring, supervised by a doctor in charge in a Respiratory Intensive Care Unit, who also provided a telephone-counselling (24/7) on demand; 2) a scheduled visit every two months. Methods. A 2-year observational study was carried out on 16 patients ventilated for at least 1 year and for ≥ 8 hours /day. Once a week patients underwent a nocturnal monitoring during HMV. The compliance was evaluated by regular transmission of data and regular follow-up, the level of satisfaction by a telephonequestionnaire. Results. The adherence to the protocol study was good in 9/16 (56%) and poor in 7/16 (44%) patients. For each patient, the mean number of connections was 46,12 ± 36.39 (70.7% of that expected), in those with good compliance it increased to 63.8 ± 32.7 (114% of that expected). The median hours of connection was 343 (138- 1019) and 89 (0-521) for patients with good and poor compliance respectively, p=0.038. The mean scheduled visits for patient with good compliance was 6.9 ± 4.14 (100% of that expected). Emergency visits were avoided in 62.5% of cases. The satisfaction score was higher in compliant versus non compliant patients (p=0.019). Conclusion. This pilot study showed that the telemonitoring system employed was feasible and effective in more compliant patients who claimed a high rate of satisfaction

    The Italian data on SARS-CoV-2 infection in transplanted patients support an organ specific immune response in liver recipients

    Get PDF
    Introduction: The study of immune response to SARSCoV-2 infection in different solid organ transplant settings represents an opportunity for clarifying the interplay between SARS-CoV-2 and the immune system. In our nationwide registry study from Italy, we specifically evaluated, during the first wave pandemic, i.e., in non-vaccinated patients, COVID-19 prevalence of infection, mortality, and lethality in liver transplant recipients (LTRs), using non-liver solid transplant recipients (NL-SOTRs) and the Italian general population (GP) as comparators. Methods: Case collection started from February 21 to June 22, 2020, using the data from the National Institute of Health and National Transplant Center, whereas the data analysis was performed on September 30, 2020.To compare the sex- and age-adjusted distribution of infection, mortality, and lethality in LTRs, NL-SOTRs, and Italian GP we applied an indirect standardization method to determine the standardized rate. Results: Among the 43,983 Italian SOTRs with a functioning graft, LTRs accounted for 14,168 patients, of whom 89 were SARS-CoV-2 infected. In the 29,815 NL-SOTRs, 361 cases of SARS-CoV-2 infection were observed. The geographical distribution of the disease was highly variable across the different Italian regions. The standardized rate of infection, mortality, and lethality rates in LTRs resulted lower compared to NL-SOTRs [1.02 (95%CI 0.81-1.23) vs. 2.01 (95%CI 1.8-2.2); 1.0 (95%CI 0.5-1.5) vs. 4.5 (95%CI 3.6-5.3); 1.6 (95%CI 0.7-2.4) vs. 2.8 (95%CI 2.2-3.3), respectively] and comparable to the Italian GP. Discussion: According to the most recent studies on SOTRs and SARS-CoV-2 infection, our data strongly suggest that, in contrast to what was observed in NL-SOTRs receiving a similar immunosuppressive therapy, LTRs have the same risk of SARS-CoV-2 infection, mortality, and lethality observed in the general population. These results suggest an immune response to SARS-CoV-2 infection in LTRS that is different from NL-SOTRs, probably related to the ability of the grafted liver to induce immunotolerance

    From the Apennines to the Alps: recent range expansion of the crested porcupine Hystrix cristata L., 1758 (Mammalia: Rodentia: Hystricidae) in Italy

    Get PDF
    In the last few decades, the crested porcupine (Hystrix cristata L., 1758) showed a marked range expansion in Italy. Published and unpublished material was collected to reconstruct this phenomenon. Data were gathered by means of: (i) specific papers on crested porcupine distribution and more generic books and articles, (ii) expert collaboration in various Italian regions and (iii) information from the national Vertebrates mailing list. Until the 1970s, H. cristata was only present in Central and Southern Italy, mostly in the western part. Since 1978, the porcupine has been protected by Italian national law. The species first crossed the Apennines from the Tyrrhenian coast to the Marche, where the expansion to the north may have begun, and then reached the northernmost regions. An analysis of the potential distribution of the species was performed in a species distribution modeling framework (Maxent). The model suggested a high suitability of most of the Central and Southern Italian Peninsula for H. cristata, including the two major islands. Northern Italy proved suitable for the species' establishment only in some central and western areas of the Po Valley. The core areas of the Apennines and of the Alps, as well as some areas characterized by low annual rainfall, were predicted as unsuitable. Historical and social factors related to the progressive urbanization and the consequent abandonment of the traditional land use in mountain landscapes probably helped the re-expansion of forests and uncultivated fields. Three introduced populations have been detected in Sardinia, Liguria and the province of Varese. In order to make the data collected easily consultable and to give people the opportunity to contribute to a continuous updating of the distributional map of the species, a web page dedicated to H. cristata was set up, in the framework of an open-source wildlife mapping project. © 2013 Unione Zoologica Italiana

    Relation between the bronchial obstructive response to inhaled lipopolysaccharide and bronchial responsiveness to histamine.

    No full text
    BACKGROUND: Bronchoconstriction has developed after inhalation of lipopolysaccharide in a dose of 20 micrograms in asthmatic patients and of 200 micrograms in normal subjects. This study set out to determine whether the bronchial response to lipopolysaccharide was related to non-specific bronchial responsiveness and atopy. METHODS: Sixteen subjects with a fall in specific airway conductance of 40% (PD40sGaw) after inhaling up to 900 micrograms histamine inhaled 20 micrograms lipopolysaccharide (from Escherichia coli type 026:B6) a week after bronchial challenge with a control solution of saline. The bronchial response over five hours was measured as change in FEV1 and area under the FEV1-time curve. RESULTS: FEV1 fell significantly more after lipopolysaccharide than after diluent inhalation, the difference in mean (SE) FEV1 being 4.6% (5.4%); response was maximal 60 minutes after lipopolysaccharide inhalation and lasted more than five hours. Histamine PD20FEV1 and PD40sGaw correlated with the fall in FEV1 after lipopolysaccharide inhalation. There was no difference in the proportions of responders and non-responders to lipopolysaccharide who were atopic. CONCLUSION: Lipopolysaccharide induced bronchial obstruction is associated with non-specific responsiveness but not with atopy
    • …
    corecore