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Biomedical subjects

A Mangia

Publications and source records attributed to A Mangia.

At least 55 records · Page 3Linked to original sources
PubMed1999

Validation of a liquid chromatography ionspray mass spectrometry method for the analysis of flavanones, flavones and flavonols.

The application of liquid chromatography/mass spectrometry (LC/MS) with a TurboIonspray (TIS) interface was investigated as a new method for the analysis of flavonoids. Eleven compounds belonging to three different classes of flavonoids were studied: eriocitrin, neoeriocitrin, naringin, narirutin, hesperidin, neohesperidin (flavanone glycosides), quercetin, kaempferol, galangin (flavonol aglycones), chrysin, apigenin (flavone aglycones). Chromatographic separations were performed under reversed-phase conditions using a C18 narrow-bore LC column; a mixture of an aqueous solution of formic acid (pH 2.4) and acetonitrile was used as the mobile phase. Isocratic elution was operated in the case of flavanones, whereas gradient elution was used for the simultaneous separation of flavones and flavonols. The adaptability of TIS to high flow applications allows the use of LC eluent flow rates at 200 µL/min without post-column splitting. Qualitative analysis was performed in negative-ion (NI) full-scan mode, whereas response linearity, detection limits and precision of the method were studied under NI selected ion monitoring (SIM) conditions. Characterization of isomers differing in the glycosylation was found to be possible on the basis of different mass spectra. Detection limits in the low-ng range (0.08-0.4 ng) were found, about twenty-fold lower than those reported previously. The method was applied to identify and determine the content of flavonoids in an orange juice sample. Copyright 1999 John Wiley & Sons, Ltd.

Journal Article↗
PubMed1999

Liquid chromatography-electrospray mass spectrometry of beta-carotene and xanthophylls. Validation of the analytical method.

The investigation of beta-carotene and the xanthophylls beta-cryptoxanthin, lutein, zeaxanthin, canthaxanthin and astaxanthin using reversed-phase liquid chromatography-electrospray mass spectrometry interfaced with TurboIonspray (LC-TurboISP-MS) is described. Two narrow-bore C18 columns connected in series and an isocratic solvent system containing acetonitrile-methanol (0.1 M ammonium acetate)-dichloromethane at a flow-rate of 300 microl/min (without splitting) were used. Operating in the positive-ion mode over m/z 500-650, the effects on the formation of the molecular ion species or adduct ions and the MS detector response were investigated for carotenoids, varying the orifice plate voltage, the ring voltage and the ISP voltage. Both conventional ISP and TurboISP were performed; using the TurboISP-MS system, ionization efficiency increased with respect to ISP-MS, particularly at the highest temperature (500 degrees C). Good results were particularly obtained for beta-carotene, which was detectable at the low ng level, without the use of solution-phase oxidants. Using LC columns and acquiring in single-ion monitoring mode, detection limits were estimated to be in the 0.1-1 ng range; dynamic range was established between one- and two-orders of magnitude. Better sensitivity under positive-ion than negative-ion conditions was demonstrated.

Chromatography, High Pressure Liquid↗
PubMed1999

Lack of hepatitis C virus replication intermediate RNA in diseased skin tissue of chronic hepatitis C patients.

The extent of extrahepatic hepatitis C virus (HCV) replication seems to be low-level and confined to cells of hematopoietic lineage. However, given the spectrum of extrahepatic manifestations associated with HCV, several tissues other than the liver have been suggested as targets of HCV replication and damage. The presence and level of HCV RNA were examined in 19 skin tissue samples from patients chronically infected with HCV and referred for lichen ruber planus (n = 11) or cutaneous vasculitis associated with mixed cryoglobulinemia (n = 8). Serum HCV RNA was quantitated and genotyped by assays that are available commercially. Tissue HCV RNA of genomic- and minus-strand polarity was titrated by a strand-specific semiquantitative RT-PCR. Low titers of genomic-strand HCV RNA were found in three skin specimens from patients with cutaneous vasculitis due to mixed cryoglobulinemia, but in none with lichen ruber planus. The replication intermediate HCV RNA was not detected in any of the skin tissues examined, independent of the serum HCV RNA level or genotype. It is concluded that the occurrence of cutaneous vasculitis and lichen ruber planus in chronic hepatitis C patients is unlikely to be due to HCV replication in the skin.

Adult↗
PubMed1999

HLA class II favors clearance of HCV infection and progression of the chronic liver damage.

BACKGROUND/AIMS: This study was aimed to determine whether host-dependent genetic factors modulate the outcome of HCV infection. METHODS: HLA class II DRB and DQB typing was performed in 184 infected patients and 200 healthy volunteers. Among the patients, 149 subjects had persistent HCV viremia (Group 1) and 35 subjects underwent spontaneous viral clearance (Group 2). Group 1 included cirrhotic patients with transfusion-acquired infections (n = 79), asymptomatic HCV carriers (n = 42), and patients with chronic hepatitis C responsive to interferon therapy (n = 28). RESULTS: Spontaneous viral clearance was associated with HLA DRB1*1104 (pc = 0.054, OR = 4.51, 95% C.I. 2.02-10.1) and HLA DQB1*0301 (pc = 0.0039, OR = 4.52, 95% C.I. 2.15-9.51). In Group 1 the haplotype DRB1*1104/DQB1*0301 was less frequent (4.8%) than in Group 2 (18.3%) (pc = 0.009, OR = 7.38, 95% C.I. 2.58-21.59). At the HLA level, cirrhotic patients were not different from asymptomatic HCV carriers and patients with interferon-induced viral clearance. In cirrhotic patients infected with genotype 1b, the DQB1*0502 allele was more frequently found in those with rapidly progressive liver damage (OR = 8.15, 95% C.I. 1.49-44.44), but the corrected p-value was not significant (pc = 0.09). CONCLUSIONS: The HLA haplotype DRB1*1104/DQB1*0301 appears to contribute to the spontaneous clearance of HCV infection. The predominance of the DQB1*0502 allele in cirrhotic patients with a rapidly progressive disease possibly reflects an influence of this allele on the progression of the HCV-related liver disease.

Adult↗
PubMed1999

Anticardiolipin antibodies in patients with liver disease.

OBJECTIVE: Our aim was to test the hypothesis that anticardiolipin antibodies (aCL) may cause an antiphospholipid syndrome and thrombotic events in patients with liver disease. METHODS: aCL were measured in 116 healthy controls and 372 patients with liver disease of different stage and etiology: 136 cases secondary to hepatitis C virus (HCV) infection, 139 due to hepatitis B virus (HBV) infection, 69 with alcoholic liver damage, and 28 cryptogenic in origin. Prior thrombotic events were recorded. The results were related to age, gender, stage, severity, and etiology of the liver disease, as well as to the occurrence of organ- and nonorgan-specific autoantibodies. RESULTS: aCL were positive in 4.4% of controls and in 18.8% of patients (p < 0.0002). Patients with aCL were more frequently men with an advanced cirrhosis and simultaneous occurrence of anti-smooth-muscle antibodies (ASMA) in serum (p < 0.0006); their liver damage was often secondary to HBV (37.3%) or alcohol abuse (18.5%). At conditional logistic regression analysis, only the presence of ASMA (odds ratio [OR] = 3.02, 95% confidence interval [CI] 1.7-5.5, p = 0.0003), HBV (OR = 3.4, 95% CI 1.6-7.2, p = 0.0013), or alcoholic liver disease (OR = 5.3, 95% CI 2.3-12.2, p = 0.0001) were independently associated with aCL. Thrombosis was encountered in 24 patients (6.4%). At conditional logistic regression analysis, thrombosis was significantly associated with advanced age (OR = 1.07, 95% CI 1.0-1.1, p = 0.0094), development of hepatocellular carcinoma (OR = 17.8, 95% CI 1.6-196.0, p = 0.01), HBV etiology (OR = 6.3, 95% CI, 1.6-24.6, p = 0.0076), or cryptogenic liver disease (OR = 54.8, 95% CI 5-599.9, p = 0.001). Of the five patients with newly documented portal thrombosis during the follow-up, only one tested positive for aCL. CONCLUSIONS: In patients with nonautoimmune liver disease, aCL production is an epiphenomenon of the liver damage and is not associated with thrombotic complications. These data do not support the hypothesis that HCV is a cause of the antiphospholipid syndrome.

Antibodies, Anticardiolipin↗
PubMed1998

HCV and diabetes mellitus: evidence for a negative association.

OBJECTIVE: Uncontrolled, retrospective clinical studies have recently claimed that HCV infection could trigger the onset of diabetes mellitus (DM). We sought to verify the association between DM and liver diseases of different etiology, stage, and severity in a prospective study including gender- and age-matched controls. METHODS: Two hundred forty-seven patients with liver cirrhosis (184 men, 116 with an associated hepatocellular carcinoma, 34% in Child-Pugh's class A) were evaluated (group 1). One hundred fifty-seven (63.5) of them were HCV positive, 38 (15.5%) HBV positive, 49 (19.8%) alcohol abusers, and three (1.2%) cryptogenic. Two control groups were also included. The first control group consisted of 138 patients with chronic hepatitis due to HCV infection (73.9%), HBV infection (15.9%), or alcohol abuse (10.2%) (group 2). The second control group included 494 patients with an acute osteoarticular trauma, age- and gender-matched with patients in group 1 (group 3). RESULTS: Diabetes mellitus was present in 32.3%, 3.6%, and 9.7% of patients in groups 1, 2, and 3, respectively. When compared with controls (group 3), DM was significantly less frequent in group 2 (p < 0.004) and significantly more frequent in group 1 (p < 0.0001). The prevalence of DM was not different among patients with HCV, HBV infection, or alcohol abuse. In group 3, the prevalence of DM appeared to increase steadily with age. On the contrary, in patients with liver cirrhosis (group 1) DM was detected in about 20-30% of cases in all decades of age. In group 2, diabetics were found only in the 7th and 8th decades of life. At multivariate analysis cirrhosis and age were the only two factors independently associated with DM; odds ratios were 12.5 (95% confidence interval [C.I.], 6.74-20.4) for cirrhosis, and 1.47 for age (95% C.I. 0.39-2.55). CONCLUSIONS: Our findings disprove HCV infection as a trigger factor for DM, which should not be listed among the various extrahepatic manifestations of this viral infection.

Adult↗
PubMed1998

nm23 expression in human breast cancer: correlation with cell proliferation (S-phase) as observed with a double-labeling immunocytochemical-autoradiographic technique.

In 51 unselected breast cancer samples, a double-labeling immunocytochemical technique was utilized to observe the phenotypic expression of the nm23 gene during S-phase. The feasibility of the method was confirmed by comparison with routine evaluations for both thymidine-labeling index and nm23 (p<0.001). No correlation was found between the two parameters in the overall series or when subgroups regarding menopausal status, nodal involvement, tumor size, hormone receptor content were considered. Tumors with a higher nuclear grade showed a significant correlation only with TLI (p=0. 02). A trend for an inverse relationship between the two parameters was noted but was not statistically significant. A significant association between TLI and nm23 expression was found by Chi-square test using median values as cut-off. Our data based on morphological and in situ observations do not confirm a correlation between nm23 and cell proliferation, even if this correlation cannot be completely excluded. Multicentric trials of high power with these same techniques are still necessary to definitely establish the prognostic role of nm23 in breast cancer.

Adult↗
PubMed1998

Timing of breast cancer surgery within the menstrual cycle: tumor proliferative activity, receptor status and short-term clinical outcome.

We verified the variations of primary tumour steroid receptor status and proliferative activity at different times and phases (follicular vs luteal) of the menstrual cycle and their relationship with short clinical outcome in a cohort of 248 N- breast cancer patients. Steroid receptor content (ER and PgR) was evaluated by DCC assay and proliferative activity by 3H-Thymidine autoradiographic assay (TLI). Median age was 44 years, 60% of tumors were T1, and cytohistological grade was G1-2 in 54% of cases. At surgery, 57% were in the luteal phase while 43% were in the follicular phase. No significant variations were found in mean TLI or ER and PgR characteristics of the primary tumors surgically treated in different periods of the menstrual cycle; however, the ER level resulted significantly higher in 4th with respect to the 3rd week of menstrual cycle, while PgR level was higher in PgR+ cases treated during the 3rd week. The number of relapses and disease-free survival curves after 36 months median follow-up did not differ significantly for patients treated in different periods of the menstrual cycle (12% and 9% of disease relapses in luteal and follicular phases; p=n.s.). We can conclude, therefore, that TLI, ER and PgR expressions could vary significantly during menstrual cycle only in certain specific tumor subgroups.

Adult↗
PubMed1997

Prolonged treatment (2 years) with different doses (3 versus 6 MU) of interferon alpha-2b for chronic hepatitis type C. Results of a multicenter randomized trial.

BACKGROUND/AIMS: To examine the effect of prolonged treatment with different doses of interferon alpha-2b on the relapse rate in patients with chronic hepatitis C. METHODS: One hundred and seventy-one patients with non-cirrhotic chronic hepatitis C were enrolled in an Italian multicenter trial. All patients were treated for 3 months with 3,000,000 Units (3 MU) of interferon alpha-2b given subcutaneously three times a week (t.i.w.). Patients with abnormal alanine aminotransferase (ALT) values were given 6 MU of interferon for an additional 3 months. If ALT remained persistently abnormal, therapy was then suspended. If ALT levels were normal, therapy was continued (6 MU t.i.w.) for an additional 18 months (total=2 years). Patients with normal ALT were randomly assigned to two groups, one receiving 3 MU and the other receiving 6 MU t.i.w. for an additional 21 months (total=2 years). Follow-up continued for 2 years after therapy withdrawal. RESULTS: Seven patients stopped treatment during the first 3 months. Of the remaining 164 patients, 76 (46%) showed abnormal ALT levels after 3 months of therapy: 11 of these (14%) normalized ALT values when given 6 MU and a sustained response was maintained in eight during the follow-up. Overall, 54 and 34 patients were allocated respectively to the groups receiving the 3 MU and 6 MU long-term treatment. At the end of therapy, 35/54 patients of the group 3 MU and 21/34 patients of the group 6 MU showed normal ALT levels (65% vs 62%, p=N.S.). After 2 years of follow-up, 24/35 (69%) patients of the group 3 MU and 16/21 (76%) of the group 6 MU were still in remission (p=N.S.). In an intention-to-treat analysis, 48/171 (28%) patients showed a long-term response (normal ALT values, HCV-RNA negative). About 65% of the sustained responders showed low baseline viremia compared with 33% of non-responders (p=0.005) while genotype 1b was more frequently found among non-responders than in long-term responders (84% vs 25%, p=0.0001). CONCLUSIONS: About 14% of patients who do not respond to a 3-month course of 3 MU of interferon normalize ALT levels when given 6 MU. In prolonged treatment, there is no significant difference between 3 and 6 MU in inducing a sustained response. Patients with low baseline viremia and genotype 2a respond significantly better to prolonged interferon therapy than highly viremic patients with genotype 1b.

Antiviral Agents↗
PubMed1997

HCV genotypes in patients with liver disease of different stages and severity.

UNLABELLED: AIMS/MATERIAL: Hepatitis C virus (HCV) genotyping was performed in 213 anti-HCV-positive patients with chronic liver disease ranging from minimal histological changes to hepatocellular carcinoma. One hundred and twenty-two patients had non-cirrhotic chronic active or persistent hepatitis (including 29 who were asymptomatic with persistently normal ALT levels) (chronic liver disease group). The other 91 had hepatocellular carcinoma and, in all but three cases, cirrhosis (hepatocellular carcinoma group). RESULTS: The overall prevalence of HCV variants was: 54.9% type 1b, 37.8% type 2, 2.5% type 1a, 2.0% type 3a, 2.0% type 4a. The genotype distribution showed no relation to the stage (chronic liver disease vs. hepatocellular carcinoma) or severity (chronic active vs. chronic persistent hepatitis) of the liver disease, or to the duration of the disease (<10 years vs. >10 years). Within the hepatocellular carcinoma group, the duration of type-1b disease was similar to that of type-2 infections. Ages at the time of infection and genotype were both independently associated with progression to cirrhosis and hepatocellular carcinoma, but multivariate analysis revealed that the effect of age was much stronger than that of genotype 1b. CONCLUSIONS: The predominance of HCV type 1b in this study reflects the higher frequency of this variant in our area. Our findings indicate that infections caused by each HCV genotype are capable of progressing to hepatocellular carcinoma.

Adolescent↗
PubMed1996

Applications of liquid chromatography-mass spectrometry interfacing systems in food analysis: pesticide, drug and toxic substance residues.

This paper reviews applications of different LC-MS techniques for the determination of xenobiotic substances in foods. Specific examples of contaminants discussed are pesticides, herbicides, insecticides and drugs; concerning toxic substances, mycotoxins, phycotoxins, cyanobacterial toxins, mutagenic and heterocyclic amines and beta-carbolines, arsenic, tin and inorganic halogen compounds, packaging materials and various epoxy resins are considered. Advantages and limitations are outlined for the different LC-MS interfacing systems (particle beam, thermospray, atmospheric pressure ionization with electrospray, ionspray and heated pneumatic nebulizer). The impact of developments in instrumental analysis on methodology and the limitations of the various LC-MS methods are discussed. Further, the coupling of LC with element-selective detection systems such as inductively coupled plasma mass spectrometry is discussed, with emphasis on speciation of trace toxic elements in foods.

Chromatography, Liquid↗
PubMed1996

Pathogenesis of chronic liver disease in patients with chronic hepatitis B virus infection without serum HBeAg.

Chronic hepatitis B in patients lacking hepatitis B e antigen has been attributed to a hepatitis B virus variant (G-to-A mutation at nucleotide 1896 in the precore region of the genome). We therefore assessed the frequency and significance of this variant among 43 United States patients (10 with chronic hepatitis B seropositive for e antigen, 19 seronegative for e antigen, and 14 healthy carriers). Sera were tested for HBV DNA by polymerase chain reaction and branched DNA assay. The A1896 variant was detected by direct sequencing and ligase chain reaction. Serum HBV DNA was more frequently found among patients with e antigen-positive than e antigen-negative chronic hepatitis B. Viral titers were generally higher in those with e antigen. None of the e antigen-positive and only 24% of e antigen-negative patients harbored the A1896 variant. Patients infected with the variant were more often Asian, had had hepatitis B for longer and had higher levels of viral DNA than HBeAg-negative patients with the wild-type virus. The A1896 variant was found exclusively in patients infected with HBV genotypes C and D. Thus, the A1896 variant is uncommon in the United States. The activity of liver disease appears to be more closely related to the level of HBV replication than the presence of mutations at nucleotide 1896 in the genome.

Adult↗
PubMed1996

Determination of phylloquinone (vitamin K(1)) by high performance liquid chromatography with UV detection and with particle beam-mass spectrometry.

A reversed-phase PB LC-MS method was used for the determination and unequivocal identification of vitamin K(1) in some vegetable samples. The method was also applied to the identification of other constituents in the food analyzed. LC-MS experiments were carried out in both EI and negative-ion CI modes. Preliminary sensitivity studies on vitamin K(1) showed a detection limit of 2 ng (signal-to-noise ratio=3) in negative-ion operation and in single-ion monitoring at m/z 450. Quantitative results obtained with LC-MS for the extracts of four vegetables were compared with those of LC-UV analyses performed at 247 nm.

Journal Article↗
PubMed1996

Hepatitis C virus infection and monoclonal gammopathies not associated with cryoglobulinemia.

A pathogenetic role of HCV has been recently postulated in some lymphoproliferative disorders and in particular in essential mixed cryoglobulinemia. To assess the relevance of HCV infection in multiple myeloma, Waldenström's macroglobulinemia and monoclonal gammopathy of undetermined significance in the absence of cryoglobulinemia (cryo-ve MG), 102 patients were evaluated for antiHCV, HCVRNA and HCV genotypes. A control group of 466 patients referring for acute trauma to the Orthopedic Division of our hospital was also studied. The overall prevalence of HCV was 15.6% in MG patients and 5.4% in the control group (P= < 0.001). Since only patients with MG older than 50 years had HCV infection, we compared the prevalence rate of infection in patients aged 50 and older: in cryo-ve MG HCV prevalence was 17.9%, while in patients with an acute trauma it was 10%; the difference was not statistically significant. In addition, occurrence of cryo-ve MG was investigated in 614 antiHCV+ patients with chronic liver disease and was found in 1.9%. Comparing all the 28 cryo-ve MG patients HCV+ with an appropriately matched control group of HCV+ patients without MG, no difference in severity of liver disease and genotype distribution was detected. These findings show that: (1) among cryo-ve MG, HCV infection is frequent as shown in the appropriately matched control population; (2) prevalence of cryo-ve MG in antiHCV patients with chronic liver disease is similar to the rate found in the general population; and (3) HCV infection and disease do not differ in patients with and without cryo-ve MG.

Adult↗
PubMed1996

[Dna synthesis and expression of steroid receptors in cells of human breast carcinoma].

In order to observe receptor expression (ER and PgR) in human breast cancer cells during the S-phase of the cellular cycle, we evaluated 21 tumoral samples using a double labeling immunocytochemical-autoradiographic assay. In 16 of these we have verified that expression of ER and PgR is not influenced by incubation with 3H-Thymidine for 60 minutes. The results also demonstrated that receptor expression during the S-phase is more common in postmenopausal tumors and is principally dependent on percentages of ER+ (p < 0.01) and PgR+ (p < 0.01) cells; moreover, proliferative activity occurs almost exclusively in ER- (p = 0.003) and Pgr- (p = 0.001) cellular sub populations and the presence of PgR, but not of ER, is related to arrest of DNA synthesis (p = 0.02).

Adult↗
PubMed1995

Heterogeneity of intratumour proliferative activity in primary breast cancer: biological and clinical aspects.

The present retrospective study was undertaken to verify whether the extent of intratumour proliferative activity variation or the method of quantifying tumour proliferative activity is related to biological characteristics and clinical outcome in a series of operable node-negative breast cancer patients. For tumour proliferative activity evaluation, the 3H-thymidine autoradiographic assay was used. After incubation of 3-8 samples from different areas of the equatorial section of each tumour for 1 h at 37 degrees C with 3H-thymidine, the following methods were used for evaluation of tumour cell labelling: mean tumour labelling index (LI), the highest labelling value from a specific area (LI-max), and the extent of intratumour labelling variation from several samples (LI-CV). LI-max was related to ER and PgR status, and linearly correlated with LI (c.c. = 0.92, P < 10(-6)) whereas LI-CV was independent of tumour size, grade ER and PgR status, but dependent on the number of tumour samples analysed for each tumour. After 5 years of median follow-up, disease-free survival was only related to tumour size (T1 versus T2: 84 versus 64%, P < 0.04 by log rank analysis) and different LI values (low versus high 3H-Tdr-LI:86 versus 61%, P < 0.03 by log rank analysis). LI-max and LI-CV values were not significantly related to clinical outcome. Cox multivariate analysis confirmed the independent prognostic value of LI and tumour size on disease-free survival.

Breast Neoplasms↗