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Biomedical subjects

A Facchini

Publications and source records attributed to A Facchini.

At least 127 records · Page 7Linked to original sources

Idiopathic pulmonary fibrosis: can cell mediated immunity markers predict clinical outcome?

Most of the cells found in lung parenchyma in patients with idiopathic pulmonary fibrosis are activated T lymphocytes and macrophages. The serum levels of three markers of cell mediated immunity were measured in 20 patients with idiopathic pulmonary fibrosis, in 20 normal subjects and in 12 patients with sarcoidosis to evaluate their clinical and prognostic significance in idiopathic pulmonary fibrosis. The three markers were: soluble CD8 (from activated suppressor-cytotoxic lymphocytes), soluble interleukin (IL)-2 receptors (from activated T cells and macrophages), and neopterin (from activated macrophages). Patients with idiopathic pulmonary fibrosis had higher levels of all three markers than the control subjects. Soluble IL-2 receptor and neopterin tended to be lower (though not significantly) in patients with idiopathic pulmonary fibrosis than in those with sarcoidosis, whereas soluble CD8 was similar in the two groups of patients. No correlation was found between soluble IL-2 receptors or soluble CD8 and the clinical, radiological, and physiological measures of disease activity or with clinical outcome (after a mean follow up of 23 months). Tumour necrosis factor levels were also determined. Only 30% of patients with idiopathic pulmonary fibrosis or sarcoidosis had detectable circulating tumour necrosis factor; these patients had a lower percentage of bronchoalveolar lavage fluid neutrophils in their lavage fluid. Tumour necrosis factor levels did not correlate with clinical measures of severity or outcome. Thus our data support the hypothesis that cell mediated alveolitis occurs in idiopathic pulmonary fibrosis. They do not, however, provide evidence to support the use of these markers of cell mediated immunity to monitor the clinical course in these patients.

Adult↗

Autoantibodies to poly(ADP-ribose)polymerase in autoimmune diseases.

Antibodies to various nuclear proteins are frequently found in sera of patients affected by connective tissue diseases and other autoimmune diseases. We investigated the specificity of circulating autoantibodies to poly(ADP-ribose)polymerase (pADPRP) in different autoimmune and connective tissue diseases: Systemic Lupus Erythematosus (SLE), Rheumatoid Arthritis (RA), Progressive Systemic Sclerosis (PSS), Sjogren's Syndrome (SS), Undifferentiated Connective Tissue Disease (UCTD), Cryptogenic Fibrosing Alveolitis (CFA) and Sarcoidosis. pADPRP was purified from calf thymus. Antibody specificity was detected by ELISA, western blot and enzyme activity precipitation. Positive values (mean O.D. values + 3 S.D. of 36 normal controls) were obtained in 7/15 SLE patients, 1/18 RA patients, 1/30 PSS, 3/14 SS, 0/5 UCTD, 5/21 CFA and 4/25 Sarcoidosis. The positive sera also recognized the pADPRP protein when tested by western blot. Furthermore the enzyme activity was inhibited after immunoprecipitation by some highly positive sera.

Adolescent↗

A morphological study of membrane lesions during natural killer-mediated lysis.

Early and late events occurring during cell-mediated cytolysis have been examined ultrastructurally using transmission, scanning and freeze-fracture electron microscopy. K562 erythroleukemic cells were used as target for human natural killer lymphocytes, a subpopulation involved in host defense against tumor, virus infected and allogeneic cells. Cell binding between target and effector is already evident after 15 min, but membrane lesions and target hydration appear after 30 min incubation. At 60 min K562 cells appear swollen and microvilli-deprived. Progressive membrane disruption is also evident and the underlying cytoplasmic material is clearly exposed after 120 min. Submicroscopic membrane lesions appear to be early events in comparison with 51Cr (isotope) release from damage cells.

Cell Membrane↗

[Periodontal status of a military group. Epidemiological considerations].

The authors studied the periodontal status of a group of Italian soldiers. The authors used the Community Periodontal Index for Treatment Needs, as suggested by the FDI according with the WHO. Besides they carried out a statistical analysis of the results. It was possible to point out bad periodontal conditions in the population examined.

Adult↗

Autoantibodies to DNA topoisomerase II in cryptogenic fibrosing alveolitis and connective tissue disease.

Sera from patients with autoimmune lung and connective tissue diseases were investigated for antibodies to topoisomerase II. Anti-topoisomerase II antibodies were detected by ELISA in 37% of sera from patients with cryptogenic fibrosing alveolitis (CFA), in one (8%) case of sarcoidosis and in 31% of sera from systemic lupus erythematosus (SLE) patients. Sera from rheumatoid arthritis, juvenile rheumatoid arthritis, progressive systemic sclerosis, Sjögren's syndrome and undifferentiated connective tissue disease were negative. CFA and sarcoidosis sera strongly reacted in immunoblotting with a 170 kD protein, also recognized by rabbit antiserum to recombinant topoisomerase II, while SLE sera presented a weak reaction. Pre-adsorption with dsDNA dramatically decreased the topoisomerase II binding in ELISA by the most positive SLE serum, but did not affect the binding by the most positive CFA serum, thus indicating that anti-topoisomerase II reactivity of SLE sera is probably due either to cross-reacting antibodies or, in part, to minor DNA contamination of our enzyme preparation. The determination of DNA topoisomerase II relaxation activity, performed after incubation with antibody-positive sera, showed that only CFA sera precipitate enzymatic activity. The finding that CFA presents antibodies to an enzyme essential to cell survival stresses the role of autoimmunity in the pathogenesis of idiopathic pulmonary fibrosis. This may offer further insight into the cause of autoimmune disease and prove a valuable tool in the study of enzyme molecular biology.

Adolescent↗

Natural killer function in flow cytometry. I. Evaluation of NK lytic activity on K562 cell line.

Flow cytometry has been employed to establish an NK assay using the K562 target cell line. These cells show a perpendicular light scatter (PLS) characteristically different from lymphocytes. Other physical parameters, such as forward light scatter (FLS), do not discriminate between the two populations, since dead K562 cells display similar FLS characteristics as effector cells. Killed cells are stained with propidium iodide and followed by flow analysis. It was advisable to add the dye in the medium so that, as long as the target cells are killed they will also be stained. Moreover the flow cytometric and trypan blue evaluation of target cell death rate showed a stronger correlation than did either test with the conventional 51Cr release assay, the first two methods both being based on the same biological mechanism.

Cell Membrane Permeability↗

Acute phase proteins in chronic and malignant liver diseases.

Six acute phase proteins (haptoglobin, alpha 1-acid glycoprotein, alpha 1-antitrypsin, alpha 2-macroglobulin, C reactive protein and transferrin) have been measured in the sera of chronic liver disease (CLD) patients with different aetiology (viral, autoimmune and alcoholic) and histology (steatosis, chronic persistent hepatitis, chronic active hepatitis, cirrhosis), and in patients with liver cancer. 1) The most striking changes concerned alpha 2-macroglobulin (increased) and haptoglobin (decreased) levels. 2) Transferrin was lower in alcoholic liver disease than in viral CLD, CRP was lower in autoimmune than in viral or alcoholic CLD, and alpha 1-acid glycoprotein was lower in viral and alcoholic CLD than in autoimmune CLD. Acute phase protein assay may prove useful in differential diagnosis, particularly when specific markers are not available (autoimmune, non A, non B, alcoholic liver diseases). 3) No significant differences related to aetiology (B, non A non B, D viruses) were observed in viral CLD. 4) Patients who progressed to CLD after acute viral hepatitis type B or non A non B did not show different APP levels from those who had recovered when tested 8-12 months after the acute phase. 5) The pattern of APP changes observed in primary liver cell carcinoma was different from both the cirrhotic pattern and the pattern presented by other tumours with or without liver metastasis.

Acute-Phase Proteins↗

A high yield technique for freeze-fracturing of small fractions of isolated cells.

A simple, high-yield technique for the freeze-fracturing of small amounts of isolated cells is described. A drop of cells fixed in suspension is deposited on a polylysine-treated coverslip, forming a monolayer through electrostatic forces. After cryoprotection, the coverslip is inverted on a gold carrier covered with Vinol and then frozen in liquid nitrogen. The monolayer will be fractured by advancing the knife under the coverslip. Large areas of cell surface can be exposed despite their low number, such as that obtainable after cell sorting by flow cytometry.

Erythrocytes↗

Use of poligonal windows for physical discrimination among mononuclear subpopulations in flow cytometry.

Peripheral blood mononuclear cells from ten healthy normal donors were analyzed by means of monoclonal antibodies and flow cytometry (FACS IV). In order to apply optimal gating for the identification and exclusion of monocytes from lymphocyte populations, mononuclear cells were analyzed on the scattergram using rectangular or poligonal computer-generated windows. Two main windows on lymphoid population were used which mainly differed for the up-right corner, in the border area between lymphocytes and monocytes. While the number of lymphocytes contained either in the regular or in the poligonal windows was the same, the number of contaminating monocytes decreased by two-fold in the poligonal one. Besides, the use of tight lymphocyte gating, in order to reach lower monocyte contamination, leads to a loss of lymphoid cells which does not appear to be random, but seems to affect mainly the Leu11c+ population with natural killer activity. These cells produce forward and perpendicular scatter signals higher than other lymphocyte subsets, and, therefore, are mainly located in the area of the scattergram which divides lymphocytes from monocytes. These data are in accordance with the large granular morphology of natural killer cells. The use of the poligonal windows seems to be useful to reduce monocyte contamination with no selective loss of natural killer lymphocytes, and may be particularly helpful in the analysis of pathological samples.

Antibodies, Monoclonal↗

Autoantibodies to purified nuclear proteins related to DNA metabolism during ageing and in SLE patients.

In this study the specificity of circulating autoantibodies in ANA+ aged donors, ANA- donors and SLE patients was investigated by immunoblotting on total nuclear proteins and by ELISA on purified nuclear proteins, possibly related to DNA metabolism, such as DNA polymerase alpha, DNA-dependent ATPase, DNA Topoisomerase I, ssDBP, hnRNP, HMG and histones. Immunoblotting showed that sera from ANA+ aged donors present fewer antibodies to nuclear proteins, especially to those between 21,000 and 45,000, molecular weight (MW), than sera from SLE patients. When the specificity of antisera was further studied on purified nuclear proteins, it was found that the majority of sera from SLE patients react with most of the proteins tested, whereas sera from ANA+ aged donors mainly react with DNA polymerase alpha, DNA-dependent ATPase, DNA Topoisomerase I and histones. In addition, sera from a few ANA- donors also reacted with certain purified nuclear proteins in a statistically significant age-related manner.

Adolescent↗

Increased number of circulating Leu 11+ (CD 16) large granular lymphocytes and decreased NK activity during human ageing.

The phenotype and functional activity of circulating T and natural killer (NK) cells was investigated in a group of selected normal elderly donors in comparison with a group of normal young individuals. Old subjects exhibit a decline in circulating T cells and an impaired response to mitogens (Con A, PHA) associated with a relative increase in cells reacting with Leu 7 and Leu 11a monoclonal antibodies, directed against large granular lymphocytes with NK activity. The rise in circulating NK cells observed in the elderly was not associated with a concomitant increase in NK cytolytic activity against K 562 tumour cells, and time course kinetics of the cytotoxic reaction was similar to that observed in young subjects. When a greater than 95% pure population of Leu 11a+ cells from old individuals was sorted by flow cytometry and their functional cytotoxic activity examined, a significant decrease in NK cytotoxicity was detected. The target cell binding capacity of effector cells, morphologically evaluated at single cell level, did not differ in old and young subjects, even though bound cells from young donors have a higher lytic capacity. These data show that an increase in circulating NK granular lymphocytes occurs during human ageing, but suggest that in old subjects only a subset of NK cells is active in order to maintain a functional response similar to that observed in the young.

Adult↗

Radiosensitization by tinidazole: pharmacokinetic study.

In previous study on cell-cultures, the authors have proved that tinidazole had radiosensitizing properties on hypoxic cells similar to those of metronidazole. The radiosensitizing activity of tinidazole becomes useful in vitro using a concentration of 1 millimol. The purpose of this study was to determine the dose of tinidazole necessary to produce a useful radiosensitizing effect in patients cured by radiotherapy. The pharmacokinetic properties of tinidazole were studied by treating patients with 1.5-3-4.5 g of the drug per day, using single doses for two consecutive days. The plasma concentration was determined by 15 series samples during a period of 48 h. Moreover endotumoural concentrations of tinidazole were studied in a group of patients using high pressure liquid chromatography techniques. The results showed that a dose of 4.5 g of tinidazole was sufficient to reach plasmatic and endotumoural concentrations similar to those which provide a radiosensitizing effect in vitro with an enhancement factor ratio of approximately 1.5. The initial dose and the accumulation factor were also determined in order to maintain the above-mentioned concentrations for a time sufficient to be able to apply multiple daily fractions of radiotherapy. The tolerance of the drug throughout the study was excellent.

Drug Administration Schedule↗

Liver-specific autoantibodies in chronic hepatitis B virus infection.

Anti-liver-specific protein (LSP) antibody and liver membrane autoantibody (LMA) have been evaluated in 88 patients with hepatitis B virus (HBV)-induced chronic liver disease by means of radioimmunoprecipitation and immunofluorescence. Among our patients, 38 presented circulating HBe antigen while 43 had HBe antibody and seven were negative for both. Anti-LSP was mainly found in HBeAg positive chronic active hepatitis (CAH), anti-HBe in positive CAH and in anti-HBe positive chronic persistent hepatitis (CPH). Similar prevalences of LMA (range 13-33%) were detected in the various groups studied. Taking into account the histological diagnosis of disease activity (periportal inflammation and piecemeal necrosis) no significant differences were found between active and inactive patients. Taking into account the HBeAg/anti-HBe status, no significant differences were found between the patients positive for 'e' antigen or 'e' antibody. Humoral autoimmune reactions may also play a role in HBV-induced chronic (active) liver disease irrespective of HBeAg/anti-HBe status and hence of the viral replication activity of the patients.

Autoantibodies↗

Oxmetidine (SK&F 92994): pharmacokinetic study in patients with in patients with liver cirrhosis.

The pharmacokinetics of oxmetidine (SK&F 92994) were investigated in nine cirrhotic patients and compared with ten control subjects with gastroduodenal ulcers, but without any symptoms of hepatic pathology. On two separate occasions each patient received 200 mg oxmetidine as a single oral dose and 100 mg as a single intravenous dose. In the cirrhotics, the bioavailability of the oral dose and the plasma elimination half-life after both oral and intravenous administration were significantly higher than in the controls. Moreover, a positive correlation was found between the plasma elimination half-lives and the biochemical parameters of cholestasis. Such findings indicate that in severe liver disease and in cholestasis the accumulation of oxmetidine in the circulation may limit the use of this drug.

Aged↗

Circulating hepatocyte membrane-specific autoantibodies in chronic active hepatitis type B. Relation to virus replication activity and liver cell necrosis.

Sera from two groups of untreated HBsAG-positive patients with chronic active hepatitis on liver biopsy were tested for antibodies to liver cell membrane antigens (liver-specific protein, LSP; and liver membrane antigen, LM-Ag). Among the 14 HBeAg-positive cases, seven (50%) were positive for anti-LSP, whereas only two (13%) of 15 anti-HBe-positive cases circulated this antibody. Liver membrane autoantibody (LMA) was detected only in two sera from delta-positive patients (1 HBeAg positive and 1 anti-HBe positive). Anti-LSP-positive patients presented transaminase values significantly higher than those of the negative cases. Our data do not support the hypothesis that a liver-specific autoimmune mechanism plays a significant role in the immunopathogenesis of liver cell necrosis in anti-HBe-positive chronic active hepatitis type B. The relationship between hepatocyte necrosis and anti-LSP antibody response is confirmed.

Adult↗