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Biomedical subjects

C Ferrari

Publications and source records attributed to C Ferrari.

At least 163 records · Page 9Linked to original sources
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↗
PubMed1987

Intrahepatic, nucleocapsid antigen-specific T cells in chronic active hepatitis B.

Hepatitis B core antigen (HBcAg)-specific T cell lines were established from hepatic lymphomononuclear cells derived from five patients with chronic active hepatitis B. No hepatitis B virus envelope antigen-specific cell lines were established. Proliferation in response to recombinant and native HBcAg, but not to native hepatitis B surface antigen containing the pre-S(2) region, confirmed the specificity of the five T cell lines. All cell lines represented mixed populations of CD4+ and CD8+ T cells. The CD4+ subset provided antigen-specific help to autologous B cells with respect to anti-HBc production and to CD8+ cells with regard to HBcAg-induced proliferation and suppressor activity. The CD8+ subset contained suppressor cells that selectively inhibited the proliferative response of autologous HBcAg-specific CD4+ cells without inhibiting CD4+ cells of unrelated specificity (tetanus toxoid). Moreover, the CD8+ cells were also capable of suppressing HBcAg-stimulated antibody to HBcAg production without showing inhibition of total immunoglobulin production stimulated by pokeweed mitogen. The cytotoxic potential of the T cell lines was established in a lectin-dependent cytotoxicity system; natural killer cytotoxicity was completely absent. Our data suggest that the lesional T cells present at the site of hepatocellular injury in chronic active hepatitis B are primarily HBcAg-specific lymphocytes of the helper and suppressor/cytotoxic phenotypes and that both are functionally competent.

Antibody Formation↗
PubMed1987

Functional characterization of cloned intrahepatic, hepatitis B virus nucleoprotein-specific helper T cell lines.

We have previously reported the establishment and preliminary characterization of polyclonal hepatitis B virus (HBV) nucleoprotein (HBcAg)-specific CD4+ and CD8+ T cell lines derived from the hepatic lymphomononuclear cell infiltrate of several patients with chronic active hepatitis B. The isolated subsets from these lines were specifically activated by HBcAg and displayed antigen-specific help and suppression with respect to proliferation of the alternate subset. One of these lines was recently cloned by limiting dilution, and four HBcAg-specific CD3+ CD4+ CD8-DR+ T cell lines were produced that had a 95.3% likelihood of monoclonality. Antigenic specificity was confirmed by dose-dependent, HLA class II (DR)-restricted proliferation in response to recombinant and human serum-derived HBcAg and the lack of proliferation to HBV envelope antigens (HBsAg and pre-S(2)Ag). All cloned lines were interleukin 2 dependent, produced interferon-gamma in an antigen-specific manner, and provided antigen-specific help to autologous B cells with respect to anti-HBc production. We conclude that HBcAg-specific, HLA-class II restricted helper T cells capable of inducing antigen-specific functional responses by autologous B lymphocytes and T lymphocytes are present at the site of viral antigen synthesis and hepatocellular injury in HBV infection.

Adult↗
PubMed1987

Effects of FCE20700, a new PGE2 derivative, on gastric acid secretion and cytoprotective processes in man.

The pharmacodynamic effects of FCE20700, a new PGE2 derivative, have been investigated in 6 healthy volunteers given single intragastric (i.g.) and intraduodenal (i.d.) doses of 1 and 2 mg and placebo, according to a double-blind, within-subjects design. For 30-270 min following i.g. administration the effect of FCE20700 on peptone-stimulated gastric acid secretion (AS) was assessed by i.g. titration, and serum gastrin (G) levels were also determined. For the same period after i.d. dosing the effect of the compound on pentagastrin-stimulated AS and on mucoproteins and bicarbonate content in the gastric juice was measured. Blood pressure (BP), heart rate and possible side-effects were monitored. Following i.g. administration there was a moderate, dose-related, significant inhibition of AS; significant inhibition of G levels was observed only after the highest dose. After i.d. administration there was a very modest though dose-related and significant inhibition of AS; a brief maximal increase in mucoproteins and in bicarbonate levels was apparent after the 1 mg dose. After i.d. but not after i.g. administration of 2 mg there was a modest but significant decrease in BP. No side-effects of clinical relevance were reported. The results appear to suggest a major activity of FCE20700 on cytoprotection rather than in inhibiting gastric acid secretion. The observed change in BP may indicate that after i.d. administration there will be some systemic effects of FCE20700.

Adult↗
PubMed1987

S-100-positive T cells are largely restricted to a CD8-positive, 9.3-negative subset.

The present report concerns the demonstration of the exclusive detection among peripheral blood T-lymphocytes of the S-100 protein within the CD8-positive subpopulation which lacks the antigen recognized by the 9.3 monoclonal antibody. Highly purified human peripheral blood T-cell subsets, obtained by means of panning techniques, were first stained, by an immunofluorescence method, with purified anti-S-100 protein antibodies. The vast majority of S-100 protein- (and, specifically, its beta subunit) positive cells were detected in the CD8-positive, 9.3-negative subset. This subset had previously been shown to comprise all the alloantigen-specific and histamine-inducible suppressor T-cells. Other T-subsets, even those showing either CD8-positivity (but 9.3-positivity) or 9.3-negativity (but CD8-negativity), were, as a rule, S-100 negative. Immunoelectronmicroscopy confirmed that the S-100-positive cells, showing peroxidase activity within the cytoplasm, were found exclusively within the CD8-positive, 9.3-negative subset. This finding of S-100 protein in cells of a specific T8 suppressor subset extends the range of the known distribution of this protein and may have important implications concerning its role in the modulation of immune responses.

Antibodies, Monoclonal↗
PubMed1987

Serum free thyroid hormones in different degrees of hypothyroidism and in euthyroid autoimmune thyroiditis.

Serum total and free T4 and T3, thyroxine-binding globulin (TBG) and TSH, basal and 20, 30 and 60 min after TRH (200 micrograms, iv), were evaluated in 125 hypothyroid patients (38 with severe, 23 with mild, and 64 with subclinical hypothyroidism), in 35 euthyroid subjects with autoimmune thyroiditis, and in 51 healthy controls. T4/TBG and T3/TBG ratios were also calculated. A significant decrease in all indices of thyroid function except for T3 occurred simultaneously with a significant increase in basal and TRH-stimulated TSH levels from healthy subjects to subclinical hypothyroids, from subclinical to mild and from mild to severe hypothyroids; euthyroid patients with autoimmune thyroiditis did not differ from healthy subjects. All severe hypothyroid patients had low T4 as well as free T4 (FT4), free T3 (FT3), T4/TBG and T3/TBG ratios, but among mild and subclinical hypothyroids direct determination of FT4 and FT3 proved to be a better index of thyroid function than determination of T4 and T3 even after correction for TBG levels. FT4 was the most commonly abnormal index (19 of 23 subjects with mild and 14 of 64 with subclinical disease). Regression analysis showed that FT4, T4/TBG ratio, T4, and FT3 had a significant inverse correlation with TSH in hypothyroid patients. Discriminant analysis showed that among the thyroid parameters, FT4 is the variable which discriminates best between control subjects and the 3 groups of hypothyroid patients. These data extend previous reports and in a large series of patients confirm the biological meaning and the clinical value of direct measurement of serum free thyroid hormones in hypothyroidism.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗