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Biomedical subjects

F B Bianchi

Publications and source records attributed to F B Bianchi.

At least 163 records · Page 9Linked to original sources
PubMed1984

R1 reticulin antibodies: markers of celiac disease in children on a normal diet and on gluten challenge.

R1 reticulin antibodies were found in sera from patients with childhood celiac disease (CCD). Although the overall sensitivity of R1 in the diagnosis of CCD was relatively low (16/43 = 37%), when only those cases in an active phase of the disease were considered, the sensitivity increased (16/24 = 67%). In spite of its low sensitivity, the R1 assay did show a high degree of specificity, as this antibody was not found in children with post-enteritis syndrome or in healthy controls. R1 antibodies, when found in active CCD, always turned out to be positive when tested on human liver as substrate. While this fact did not enhance the sensitivity of the test, it strengthened its specificity, since R1, found in pathological conditions other than CCD, was nearly always negative on human tissue. Although the R1 reticulin antibody test cannot replace jejunal biopsy in the diagnosis of CCD, its assay, particularly on human liver as substrate, can be considered a useful tool in the screening of celiac patients.

Animals↗
PubMed1984

Liver cell surface expression of the antigen reacting with liver-kidney microsomal antibody (LKM).

To test the hypothesis that liver membrane antibodies, found in all liver-kidney microsomal antibody (LKM) positive sera from patients with chronic active hepatitis, were directed against antigens shared by both hepatocellular endoplasmic reticulum and plasma membranes, absorption experiments have been performed using viable isolated hepatocytes and liver microsomes as antigens. Results are in agreement with the above hypothesis, LKM, which displays a restricted organ specificity, is thus able to react with antigenic determinants expressed on the liver cell surface, as it has been demonstrated for strictly organ specific antibodies directed against thyroid, adrenal and gastric parietal cell microsomes.

Animals↗
PubMed1983

A microELISA assay to detect anti-liver-specific protein antibodies in the sera of patients with liver diseases.

A microELISA to detect anti-liver-specific protein (LSP) antibodies in human sera is described. Rabbit LSP was used as antigen. Optimal conditions for antigen concentration, serum dilution, substrate incubation time and reproducibility with time were established. The microELISA is specific, as assessed by testing anti-LSP positive sera with another lipoprotein from rabbit plasma (VLDL), although a weak cross-reactivity between LSP and VLDL was observed. The test was applied to patients with HBsAg-positive and -negative chronic active hepatitis (CAH). Ten of 26 (38%) patients were positive for anti-LSP antibodies, in comparison with healthy controls used to determine the threshold of positivity. Such a percentage is comparable with that reported for radioimmunoassay (RIA) procedures.

Antibody Specificity↗
PubMed1983

Relationship between connective tissue cells and fibronectin in a sequential model of experimental hepatic fibrosis.

The cellular and non-cellular components of fibrous septa formed at early and late stages in a sequential model of experimental hepatic fibrosis have been investigated using ultrastructural and immunocytochemical techniques. In the early septa, cells with intermediate features between lobular Ito cells and active fibroblasts were formed. These cells frequently displayed subplasmalemmal microfilaments (myofibroblast-like cells). Macrophages were also present. Scanty typical fibroblasts were present in the late septa. This cellular recruitment might be related to an extracellular glycoprotein-fibronectin-which is at present under investigation as a chemotactic factor for fibroblasts. Strong positivity for fibronectin in early septa and its sharp decrease in late septa seems to support this view. Fibroblasts and/or macrophages are the likely source of fibronectin synthesis.

Animals↗
PubMed1983

Correlation between Ito cells and fibrogenesis in an experimental model of hepatic fibrosis. A sequential stereological study.

The relationship between Ito cells and hepatic fibrogenesis has been investigated in an experimental model: intraperitoneal injection of heterologous serum in rats leads to the appearance of fibrous septa within 5 weeks. Groups of rats were sacrificed at various intervals (from 2.5 to 20 weeks), saline-injected rats being used as controls. Liver fragments were prepared for light and electron microscopy and determination of hydroxyproline. Ito cells were identified by defined morphological criteria on 1 micron sections. The volume density (VD) of Ito cells and fibrous septa, and the Ito cell index were determined. Ito cells represent a very relevant component of early septa. In later stages, the VD of cells with morphological features of Ito cells falls to very low values. This might be related to modulation of Ito cells to fibroblasts. The increase of tissue hydroxyproline is delayed with respect to the peak VD of septal Ito cells, actually corresponding to the fall in the VD of septal Ito cells. The striking increase in the VD of total Ito cells cannot be related to a theoretically possible increase in the volume of single Ito cells, as VD always parallels the Ito cell index. These data suggest a hyperplastic reaction, possibly associated with a cellular migration from the lobules to early septa.

Animals↗
PubMed1983

A post-embedding method: demonstration of fibronectin on human liver by PAP technique.

Fibronectin, one of the most relevant components of extracellular matrix, seems to mediate cell to cell and cell to substrate interactions by means of selective links with collagen fibrils and glycosaminoglycans. Post-embedding technique using PAP method has allowed us a precise localization of fibronectin on semi-thin sections and on adjacent thin sections, improving the knowledge of fibronectin-collagen relationships.

Fibronectins↗
PubMed1983

Antibodies to cardiac conducting tissue and abnormalities of cardiac conduction in rheumatoid arthritis.

The prevalence of antibodies to cardiac conducting tissue and cardiac conduction electrocardiographic abnormalities were studied in 60 patients with rheumatoid arthritis (RA). Complete or incomplete right bundle branch block (RBBB) was found in 21 patients (35%). Antibodies to cardiac conducting tissue were found in 16 (76%) of the 21 with RBBB and in eight (21%) of the 39 without RBBB. Cardiac conducting tissue antibodies (CCTA) were found only in one of 42 patients with RBBB unrelated to RA and in two out of 60 normal subjects. This newly documented immunological abnormality is thus correlated with disorder of conducting tissue.

Adolescent↗
PubMed1983

Evaluation of serum rosette inhibitory factors in chronic liver disease.

Serum rosette inhibitory factors (IF) were detected in 61% of 18 sera from HBsAg negative and in 78% of 14 sera from HBsAg positive chronic active liver disease (CALD) patients, who were not under immunosuppressive treatment. In CALD patients, who were under treatment for at least 6 months, IF were detected in 66% of the HBsAg positive patients and only in 18% of the HBsAg negative ones. After precipitation of the serum gamma-globulins by ammonium sulphate, IF were found in the supernatant only in HBsAg positive sera, while completely disappeared in HBsAg negative ones. A significant correlation between serum IF and factors reacting in immunofluorescence (IFL) with a T enriched preparation of lymphocytes was documented only in HBsAg negative cases. No correlation was found between serum IF and circulating immune complexes (IC) or lymphocytotoxins in any of the sera tested. From all these data it is concluded that serum IF detectable in HBsAg negative CALD cases are probably immunoglobulins. Our data would favour the hypothesis that they are anti-T lymphocytes antibodies, since no correlation was found between serum IF and circulating IC. Similar factors, detectable in HBsAg positive sera, are, at least in part, different. The role of such factors in the modulation of the immune response in CALD patients is discussed.

Adolescent↗
PubMed1981

Plasma amino acids as markers of liver dysfunction in cirrhotics.

To determine the role of liver dysfunction in the plasma amino acid profile of cirrhotic patients, we correlated basal plasma amino acids and several biochemical and functional hepatic variables in 29 cirrhotics with normal mental state or mild encephalopathy. Increased levels of aromatic amino acids and free tryptophan correlated positively with the extent of portosystemic shunt, as assessed by the ammonia tolerance test (r = 0.758 and r = 0.589, respectively). There was a negative correlation between these amino acids and liver function, as evaluated by the galactose elimination capacity test (r = -0.657 and r = -0.551), thus suggesting that phenylalanine, tyrosine, and free tryptophan may be considered indexes of liver dysfunction in non-comatose cirrhotics.

Adult↗
PubMed1981

HBsAg-induced hypertrophic smooth endoplasmic reticulum as a target for liver-kidney microsomal (LKM) antibodies.

To test the hypothesis that LKM antibodies are directed against antigen(s) of the smooth endoplasmic reticulum, liver biopsies from patients with HBsAg chronic hepatitis, rich in liver cells with HBsAg-induced hypertrophic SER, were used. A close correspondence was seen between cells with HBsAg-positive cytoplasm by immunoperoxidase and cells with a stronger and more homogeneous fluorescence by indirect immunofluorescence with LKM-positive sera. These results point to antigenic components of SER as reacting with LKM antibodies. The relevance of antigens present in the ribosomes and membranes of rough endoplasmic reticulum needs further evaluation.

Antibodies↗
PubMed1981

Binding of tryptophan to albumin in liver cirrhosis: a reappraisal of the problem.

The competition of free fatty acids and bilirubin in the binding of tryptophan to albumin was studied in 12 controls and 36 cirrhotics at various stages of hepatic encephalopathy. Total tryptophan was not significantly altered in cirrhotics, while free tryptophan progressively increased with the deterioration of their mental state. Bound tryptophan levels were consequently reduced in patients with cirrhosis, mainly in the presence of hepatic encephalopathy, and strictly correlated with albumin (r = 0.80). The ratio bound tryptophan/albumin, which represents the muMoles of tryptophan bound by 1 gram of albumin, did not show significant difference in the various groups of patients. No correlation was found between this ratio and the levels of free fatty acids and bilirubin, which were raised in cirrhotics. Our data suggest that the fall in albumin levels, but not the increase in free fatty acids or bilirubin, may play a role in increasing free tryptophan levels in cirrhotics. Thus, marked hypoalbuminemia may be a risk factor of hepatic encephalopathy in patients with cirrhosis.

Albumins↗
PubMed1980

Smooth-muscle antibodies in children with neuroblastoma.

Smooth-muscle antibodies (SMA) were detected in 16 of 18 (89%) children with neuroblastoma and in 43 of 172 (25%) pediatric hospital patients without malignancies. The SMA were mainly of the IgG class. The most common immunofluorescence pattern was SMA-V (vessel) and titers did not exceed 1:160. Absorption and immunodiffusion tests with action (from rabbit skeletal muscle) showed that the SMA associated with neuroblastoma are mainly directed against actin, although different antigen specificities (myosin, meromyosin) are probably involved in some cases. In both chronic active hepatitis and neuroblastoma, SMA would represent a specific response to intracellular contractile proteins (mainly actin) induced by tissue damage. A feedback role in controlling cellular proliferation has been postulated for experimentally raised SMA. This would be relevant in cases of malignancy.

Antibodies↗
PubMed1980

Prevalence of subclinical hepatic encephalopathy in cirrhotics and relationship to plasma amino acid imbalance.

Neuropsychological status, as assessed by trailmaking test; plasma amino acids, and ammonia, were studied in 54 cirrhotics without clinical evidence of encephalopathy to determine the prevalence of subclinical mental dysfunction and its relationship to metabolic abnormalities. Control values for psychometric performance were established in 54 normal subjects matched for age, sex, educational level, and employment status. Of these subjects, 16 were also used as controls for fasting ammonia and plasma amino acids. Eighteen cirrhotics (33%) showed impaired performances of the psychometric test; free tryptophan and the ratio free tryptophan to neutral amino acids were increased in 37% and 62% of cases and correlated with the psychometric scores (r = 0.45 and r = 0.70, respectively). In eight cirrhotics with mild encephalopathy, psychometric and metabolic evaluations were repeated several times during the infusion of amino acid solutions rich in branch-chain amino acids. Again significant correlations were observed between the psychometric scores and plasma amino acids. We conclude that a considerable proportion of clinically normal cirrhotics have neuropsychological deficits. The severity of impairment may be related to the plasma amino acid imbalance, namely to an increased passage of tryptophan across the blood-brain barrier.

Adult↗