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Biomedical subjects

C Ferrari

Publications and source records attributed to C Ferrari.

At least 145 records · Page 8Linked to original sources
PubMed1988

Functional modulation of hepatitis B core antigen-specific T lymphocytes by an autoreactive T cell clone.

Hepatitis B core (HBc)Ag-specific T cells present in the peripheral blood of a patient with chronic active hepatitis B were expanded by co-cultivation for 7 days with rHBcAg. After cloning at 1 cell/well in the presence of PHA and IL-2, five HBcAg-specific CD4+ cloned lines were obtained. All five lines proliferated and produced IL-2, IFN-gamma, and TNF in a dose-dependent fashion in response to HBcAg, but not to HBV envelope Ag. The cloned lines and derivative clones were HLA class II (DR1) restricted. All T cell clones were able to induce anti-HBc production by autologous B cells in response to HBcAg (helper effect). The proliferative response and the helper effect of the HBcAg-specific T cell lines and clones were augmented by co-cultivation with an autologous, autoreactive (HLA-DQ1 specific) T cell clone, even in the absence of HBcAg, and the autoreactive T cells directly stimulated anti-HBc secretion by autologous B cells, presumably due to the release of Ag-nonspecific factors. These findings define a model immunoregulatory circuit the physiologic significance of which remains to be determined.

Adult↗
PubMed1988

Hairy cell leukemia cells express CD1a antigen.

Five patients with hairy cell leukemia (HCL) were studied. Peripheral blood leukocytes, rosette-forming cells (T) and non-T-cells were stained in immunofluorescence by a panel of monoclonal antibodies to investigate the phenotype of HCL cells (HCLC). In all patients HCLC showed B-lymphocyte phenotype, although they were not stained by antibodies reactive for monocytes, natural killer cells, or T-cells. However, in all instances the large majority of HCLC were unexpectedly stained with an antibody (anti-CD1a) usually detectable only in early thymocytes and on Langerhans cells. This finding was further confirmed by immunoelectron microscopy. This type of ambiguity in the lineage of HCL could imply that HCLC might arise from cells differentiated towards the B-cell lineage, still sustaining an early antigen of a different (T) lineage. These results, moreover, extend the range of the known distribution of the CD1a antigen, which could be useful in diagnosing HCL.

Antibodies, Monoclonal↗
PubMed1988

Clinical features of hepatitis delta virus infection in a northern Italian area.

Expression of hepatitis delta virus (HDV) markers was investigated in sera from 310 patients with acute hepatitis, 63 chronic hepatitis B surface antigen (HBsAg) carriers and 76 drug addicts positive for at least one serological hepatitis B virus (HBV) marker. Acute HDV infection occurred in 17.1% of the patients with acute hepatitis. Among 40 cases of coinfection, hepatitis was severe in ten and fulminant in three. Only two of the 13 superinfected patients showed a severe hepatitis, but a high percentage (78%) of them developed chronic hepatitis one year after HDV infection. Also in our area parenteral drug addiction represents the main factor of risk for HDV infection. The high prevalence of HDV infection in our area points to the necessity for serological screening for HDV markers in patients with acute and chronic hepatitis.

Acute Disease↗
PubMed1988

The S-100 beta protein in normal human peripheral blood is uniquely present within a discrete suppressor-T-cell compartment.

The S-100-positive T lymphocytes, and, particularly, the S-100 beta subunit, are restricted, as demonstrated by quantitative subset analysis and double-labeling (gold-peroxidase) immunoelectron microscopy of T-cell subpopulations, to an unique T8-positive cell subset which interestingly was 9.3-negative and CD11b-positive. Since both the T8-positive, 9.3-negative and the T8-positive, CD11b-positive subpopulations have been demonstrated to show suppressive activities, the S-100-positive T cells seem to be closely restricted to a small T-suppressor-cell compartment. Although functional studies on viable isolated S-100 beta-positive cells are impossible to achieve, due to the lack of this protein on the cell membrane, its presence in a discrete T-suppressor compartment might suggest a possible role for the S-100 beta-positive T cells in the regulation of the immune system.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1988

Cellular immune response to hepatitis B virus antigens. An overview.

It has been suggested that the cellular immune response to HBV antigens is responsible for hepatocellular injury in acute and chronic hepatitis B. However, definitive immunological studies have so far been hampered by the lack of appropriate model systems to study HBV antigen-specific T cells. The availability of highly purified and recombinant HBV antigens and of experimental techniques to maintain in continuous growth antigen-specific T cells derived not only from the peripheral blood but also from the liver should allow a better understanding of the fine immunopathogenetical mechanisms involved in viral clearance and liver damage. Whether some important biological characteristics of HBV antigens described in the mouse system, such as the high immunogenicity of the pre-S antigens and the capacity of the nucleocapsid of HBV to be a T cell-dependent and -independent antigen, are relevant to the immunopathogenesis of liver damage during natural HBV infection in man remains to be evaluated.

Animals↗
PubMed1988

Immunoelectronmicroscopic demonstration of S-100 protein in hairy cell leukemia cells.

Hairy cell leukemia (HCL) is generally considered a neoplastic proliferation of B-cell lineage. Among immunocompetent cells, however, S-100 protein is also demonstrated in "dendritic" cells (i.e., interdigitating reticulum cells, Langerhans cells, follicular dendritic cells) and in a small percentage of T8-cells. This study reports the surprising detection of S-100 protein in peripheral blood HCL cells of B-cell type, using immunofluorescence and immunoelectronmicroscopy. However, negative results for S-100 protein staining were obtained in paraffin splenic sections of HCL cases. This report stresses the need for caution in the interpretation of immunocytochemical methods and results, and emphasizes the diagnostic ambiguity of the S-100 protein.

Blood Cells↗
PubMed1988

Simultaneous colloidal gold immunoelectronmicroscopy labeling of CD1a, HLA-DR, and CD4 surface antigens of human epidermal Langerhans cells.

The simultaneous demonstration of three surface antigens of Langerhans cells (LC) within LC-enriched fresh epidermal cell suspensions from normal human skin was achieved, by means of a triple immunogold (IG) staining, using commercially available monoclonal antibodies (moAb) and immunoreagents, in a simple pre-embedding immunoelectronmicroscopy (IEM) procedure. As a result, suspended LC were triple-stained as follows: gold particles of 40 nm revealed the CD1 a antigen; gold particles of 20 nm revealed the HLA-DR antigen; and gold particles of 5 nm revealed the CD4 antigen. All the observed epidermal Birbeck granule-bearing LC were triple IG stained, thus simultaneously expressing the three surface differentiation antigens, which are therefore different from but coexisting with each other. The present investigation assesses the constant simultaneous expression by Birbeck granules bearing LC of not only CD1a and HLA-DR antigens, but also CD4 antigen. The occurrence is therefore excluded of both CD1a-positive HLA-DR-negative LC subpopulation and CD4-negative LC subpopulation, presumably due to the different sensitivity of the various procedures performed. The hypothetical occurrence of CD4-positive, CD1a-, and/or HLA-DR-negative LC subpopulations is ruled out. This study reaffirms indeed the high specificity and sensitivity of the IG-IEM method for a precise detection of the cell surface antigens of LC, and states the suitability of the IG labeling even for accurate multiple IEM stainings of LC.

Adult↗
PubMed1988

Long-lasting lowering of serum growth hormone and prolactin levels by single and repetitive cabergoline administration in dopamine-responsive acromegalic patients.

Cabergoline, the new long-acting dopaminergic ergoline derivative, was given orally in single doses of 0.3 and 0.6 mg to eight dopamine-responsive acromegalic patients. Serum GH and PRL levels were determined before treatment, 3, 4, and 6 h and 1, 3, 5, 7 and 14 days after treatment. A control test with a single oral dose of 2.5 mg of bromocriptine was also performed. Cabergoline induced a marked fall in serum PRL level, starting within 3 h and continuing for 7 days after administering 0.3 mg, and for 14 days after 0.6 mg. The mean maximal decrease was 49% after 0.3 mg and 63% after 0.6 mg and occurred after 24 h in both cases. The latter was of similar magnitude to that induced by bromocriptine (67% at 4 h). Serum GH levels did not change after 0.3 mg of cabergoline, but decreased significantly from 3 h to 3 days after 0.6 mg of the compound with a mean maximal decrease of 42% after 24 h, and from 3 to 6 h after giving bromocriptine (mean maximal decrease 63% at 4 h). Once a week repeated administration of 0.3-0.6 mg of cabergoline was carried out in six patients, five of whom had completed the acute study; a normalization of serum GH and insulin-like growth factor I (IGF-I) levels occurred in three patients, one of whom had very high pretreatment values. In three poorly or nonresponsive patients, a better response, as assessed by both GH and IGF-I levels, was induced by increasing the dose up to 0.6 mg twice or 0.4 mg three times a week; in one case this was associated with marked tumour shrinkage. Sustained normalization of PRL levels was achieved in all cases. These data indicate that a single dose of 0.6 mg of cabergoline inhibits GH as well as PRL secretion in dopamine-responsive acromegalic patients and suggests that doses of 0.3-0.6 mg once to three times a week may prove suitable for treatment of this condition.

Acromegaly↗
PubMed1988

Prolactin-lowering effect of acute and once weekly repetitive oral administration of cabergoline at two dose levels in hyperprolactinemic patients.

To further evaluate the potency and time course of the PRL-lowering effect of single oral doses of cabergoline, two doses of the drug were given to 51 hyperprolactinemic patients who also received 2.5 mg bromocriptine according to a randomized cross-over design. One group (n = 26) received 0.3 mg, and the other (n = 25) received 0.6 mg. Both cabergoline doses induced a significant fall in serum PRL levels, which lasted, on the average, from 3 h to 5 days after 0.3 mg and from 3 h to 14 days after 0.6 mg; the mean maximum decrease after 0.3 mg was -65 +/-4% (+/- SEM), significantly (P less than 0.05) less than that after bromocriptine (group mean, -73 +/- 4%), and it was -76 +/- 3% after 0.6 mg, not significantly different from that induced by bromocriptine (group mean, -71 +/- 4%). The effect of 0.6 mg cabergoline was significantly greater than that of 0.3 mg (P less than 0.01). In a second study designed to evaluate the possible therapeutic use of the new drug, 0.3 or 0.6 mg cabergoline was administered orally once weekly for 9 weeks to 2 groups of 15 and 16 hyperprolactinemic patients, respectively. Serum PRL levels fell significantly by the first week and reached a plateau after 2 doses in the 0.6 mg cabergoline-treated group and after 5 doses in the 0.3 mg-treated group; the absolute PRL decrease was greater in the former. Ten patients in each group achieved normal serum PRL levels, and a marked decrease (greater than 50% of pretreatment values) occurred in all patients treated with 0.6 mg and in 13 treated with 0.3 mg weekly. Resumption of menses occurred during the treatment period in 15 of the 17 premenopausal women with amenorrhea. Six patients who had poor responses had better responses when given higher drug doses for 4 weeks, and serum PRL levels became normal in the 3 receiving 0.6 mg twice weekly. These data confirm that cabergoline is a long-acting oral dopaminergic drug and suggest that it may be a useful agent for the treatment of patients with hyperprolactinemia.

Adolescent↗
PubMed1988

Detection of cell surface antigens in tissue sections by means of pre-embedding immunogold staining.

The immunogold technique has been used in electron microscopy to detect cytoplasmic and extracellular antigens by postembedding techniques. It has also been used to detect plasma-membrane-associated molecules on suspended cells and, recently, to visualize cell surface antigens in ultrathin sections of Lowicryl embedded specimens. In the present study, cell surface antigens of rat kidney and human skin were identified in tissue sections by using pre-embedding immunogold labeling. Brush border microvillar antigens and dermal lymphocyte antigens both bound numerous gold particles. The immunogold staining described here has the advantage over immunoperoxidase procedures that is not subject to diffusion or reabsorption artifacts, and allows estimation of the antigen density on labeled cells. Furthermore, this pre-embedding immunogold technique is ideally suited to detecting cell surface-associated antigens since it preserves antigenicity, allows gold particle penetration and enhances cell membrane profiles.

Animals↗
PubMed1988

Compensatory changes in calcium uptake and phospholipid composition in rat renal brush border membranes after unilateral nephrectomy.

Unilateral nephrectomy (uNX) induces a decrease in calcium uptake by brush border membranes (BBM) in the remnant kidney compared to control membranes. This effect was found to occur within 48 h and persisted at 2 weeks after uNX. Moreover, this decreased calcium uptake appears to occur through a diminished binding capacity of the BBM. Our studies also show that renal hypertrophy induced a specific decrease in the content of acidic phospholipids in remnant kidney BBM by 48 h after uNX. The decrease in phosphatidylinositol 4,5-bisphosphate and phosphatidic acid was transitory but phosphatidylinositol 4-monophosphate levels remained lower in the BBM at 2 weeks after uNX compared to control membranes. These results suggest that the decreased calcium uptake by remnant kidney BBM after uNX is related to a decreased membrane content of acidic phospholipids. This effect might account, at least in part, for the decrease in fractional calcium reabsorption during renal compensatory hypertrophy.

Animals↗
PubMed1988

Regulation of endometrial transglutaminase activity during the menstrual cycle.

When human endometrial transglutaminase was measured a 10-fold higher activity was detected during the secretive phase. This change was not related to either differences in solubility of the enzyme or to selective contamination by plasma factor XIII and rather appears to depend on the expression of the tissue form of transglutaminase, suggesting that this enzyme is regulated in vivo by progesterone.

Endometrium↗
PubMed1988

One half of the CD11b+ human peripheral blood T lymphocytes coexpresses the S-100 protein.

The expression of the CD11b antigen and the presence of the S-100 (and, specifically, its beta subunit) protein within the T4- subpopulation of normal human peripheral blood lymphocytes were investigated by panning techniques, immunofluorescence analysis and immunoelectronmicroscopy. Both antigens are known to be absent in the T4+ lymphocytes. However, CD11b+ T lymphocytes represented about 30% of the T4- population; a part of them (over 1/3) belonged to and completely filled up the T4- T8- subpopulation, whereas the remaining part (almost 2/3) shared the T8 positivity. Interestingly, S-100+ T lymphocytes, which always were CD11b+ too, represented about one half of the CD11b+ T cells, but were excluded from the T4- T8- CD11b+ subpopulation, whereas they represented up to 80% of the T4- T8+ CD11b+ subset. Such findings demonstrate that the S-100+ T lymphocytes are exclusively restricted to a discrete T cell compartment which shows the T8+ CD11b+ immunophenotype. Since such T8+ CD11b+ cells had been shown to possess suppressive capabilities, we herein propose that S-100+ lymphocytes might to some extent modulate the immune responses. However, the exact functional significance of the S-100 protein still remains unknown.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1988

Does the immune response play a role in the pathogenesis of chronic liver disease?

The pathogenesis and perpetuation of hepatocellular injury in chronic inflammatory liver disease is still unclear. Several pieces of circumstantial evidence point to the importance of antigen-specific immune responses. In chronic hepatitis B virus infection, the hepatitis B virus nucleoprotein appears to be a major target antigen for both helper and cytotoxic T lymphocytes. In autoimmune chronic active hepatitis, several autoantibodies have been identified that are associated with different disease subgroups and that may be helpful to distinguish this form of chronic active hepatitis from that caused by non-A, non-B agents. In primary biliary cirrhosis, antimitochondrial antibodies are almost invariably present and have now been characterized at the molecular level.

Antibody Formation↗
PubMed1987

Evaluation of monoclonality of cell lines from sequential dilution assays.

The statistical framework necessary to analyze clonality following a two stage cloning procedure is described, and a simple table for determining the probability of monoclonality of derived cell colonies is presented. This statistical framework is designed for multistage cloning procedures and is an extension of the usual Poisson analytic technique.

Cell Line↗