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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
PubMed1991

Pyridostigmine enhances even if it does not normalize the growth hormone responses to growth hormone-releasing hormone in patients with Cushing's disease.

Subjects with Cushing's disease have diminished growth hormone (GH) response to growth hormone-releasing hormone (GHRH). The aim of our study was to investigate the underlying mechanism of this diminished GH response in these patients using pyridostigmine (PD), an acetylcholinesterase inhibitor, which is reported to increase GH secretion by reducing somatostatin tone. Eight subjects with untreated Cushing's disease (caused by a pituitary adenoma) and 6 control subjects received GHRH 100 micrograms in 1 ml of saline, as intravenous bolus injection 60 min after (1) placebo (2 tablets, p.o.) or (2) PD (120 mg, p.o.). After GHRH plus placebo, the GH peak (mean +/- SEM) was significantly lower in subjects with Cushing's disease (2.4 +/- 0.5 micrograms/l) compared to control subjects (25.1 +/- 1.8 micrograms/l, p less than 0.05). After GHRH plus PD, the GH peak was significantly enhanced both in subjects with Cushing's disease (7.1 +/- 2.3 micrograms/l, p less than 0.05) and in control subjects (42.3 +/- 4.3 micrograms/l, p less than 0.05). In patients with Cushing's disease, the GH response to GHRH plus PD was lower with respect to the GH response to GHRH alone in normal subjects. We conclude that hypercortisolism may cause a decrease in central cholinergic tone which is in turn hypothesized to be responsible of an enhanced somatostatin release from the hypothalamus. However, other metabolic or central nervous system alterations may act synergistically with hypercortisolism in causing GH inhibition in patients with Cushing's disease.

Adenoma↗
PubMed1991

The immunogold-silver staining procedure in the study of freshly suspended Langerhans cells at the transmission electron microscopic level.

The potential of an immunogold-silver staining for the study of human suspended Langerhans cells at the transmission electron microscopic level was evaluated. Cells were labeled, by using a preembedding technique, with 5-nm colloidal gold particles followed by silver enhancement. The use of small colloidal gold particles permits a detection of small quantities of antigen; the metallic silver deposition around gold granules gives rise to a large electron-dense marker which can be easily detected even at low magnification. Ultrastructural details were well preserved, and the background was not significant. The major advantage of the present immunogold-silver staining is that it enables to detect labeled cells easily, even when limited amounts of antigenic moieties are present on a low percentage of cells. Therefore, a rapid and simultaneous evaluation of both immunophenotype and ultrastructural details of investigated cells is allowed.

Antigens, CD↗
PubMed1991

Identification of immunodominant T cell epitopes of the hepatitis B virus nucleocapsid antigen.

Several lines of experimental evidence suggest that inclusion of core sequences in the hepatitis B vaccine may represent a feasible strategy to increase the efficacy of the vaccination. In order to identify immunodominant core epitopes, peripheral blood T cells purified from 23 patients with acute hepatitis B and different HLA haplotypes were tested with a panel of 18 short synthetic peptides (15 to 20 amino acids [AA]) covering the entire core region. All patients except one showed a strong T cell proliferative response to a single immunodominant 20 amino acid sequence located within the aminoterminal half of the core molecule. Two additional important sequences were also identified at the aminoterminal end and within the carboxyterminal half of the core molecule. These sequences were able to induce significant levels of T cell proliferation in 69 and 73% of the patients studied, respectively. T cell response to these epitopes was HLA class II restricted. The observations that (a) polyclonal T cell lines produced by PBMC stimulation with native HBcAg were specifically reactive with the relevant peptides and that (b) polyclonal T cell lines produced with synthetic peptides could be restimulated with native HBcAg, provide evidence that AA sequences contained within the synthetic peptides represent real products of the intracellular processing of the native core molecule. In conclusion, the identification of immunodominant T cell epitopes within the core molecule provides the molecular basis for the design of alternative and hopefully more immunogenic vaccines.

Amino Acid Sequence↗
PubMed1991

C-cell hyperplasia accompanying thyroid diseases other than medullary carcinoma: an immunocytochemical study by means of antibodies to calcitonin and somatostatin.

Eighteen normal thyroid glands and unaffected thyroid tissue adjacent to 37 follicular cell-derived benign and malignant tumors and to ten thyroid metastases were studied immunocytochemically with calcitonin (CT) and prosomatostatin/somatostatin (SMS) antibodies. CT- and SMS-immunoreactive cells were found in 100% of cases, though with ample variations in number. Most but not all SMS-immunoreactive cells also contained CT. Diffuse and/or nodular C-cell hyperplasia was seen in 30% of pathological thyroid glands; in concomitance with follicular adenomas, the mean C-cell number more than doubled that found in normal glands. Furthermore the proportion of SMS-immunoreactive C-cells increased from about 1% of CT-immunoreactive cells in normal adult thyroid glands to 2.5% in follicular adenomas, 3% in follicular carcinomas, 4.6% in papillary carcinomas, and 5.7% in metastases. The findings suggest that C-cell hyperplasia may be causally related to pathologic disorders affecting follicular cells. Furthermore, the demonstration that the intrathyroidal SMS cell mass is readily affected by alterations of the follicular structure of the gland suggests a possible regulatory role of SMS in the thyroidal microenvironment.

Adenocarcinoma↗
PubMed1991

Immunohistological characterization of lymph nodes in two cases of adult onset Still's disease.

Although lymphadenopathy occurs in 60% of patients with adult Still's disease, its histopathological pattern has only recently been described. We report on the immunohistological study of a lymph node biopsy and the clinical course of 2 patients with adult Still's disease. The lymph node histology was characterized by a diffuse paracortical expansion with a high content of immunoblasts and plump endothelium venules. Immunohistochemistry using the alkaline phosphatase, antialkaline phosphatase technique showed the mixed B and T cell nature both of proliferating cells and immunoblasts. When antiheavy and light chain reagents were applied, the B cell component became polytypic. Our report stresses the relevance of immunohistological investigation in the diagnostic approach to Still's disease in which histological findings, if taken alone, might be misleading.

Adolescent↗
PubMed1991

[Traumatic injuries++ of the external genitalia: a case of avulsion of the penile skin].

The Authors report their recent experience about a penis trauma with a subtotal organ skinning. After the literature analysis, the AA. explain the case, with a particular attention to the surgical repairing technique. The surgical outcomes are discussed and it is re-marked the necessity of a precise diagnostic approach and follow up, also to prevent possible unerectional chains.

Dermatologic Surgical Procedures↗
PubMed1991

[Penile metastasis of prostatic carcinoma: a case report].

Penile metastases are uncommon lesions: most often secondary to a primary pelvic cancer (prostate, bladder and rectum) they have a unfavourable prognosis. The appearance of disseminations is still controversial and there is not an efficacious therapy. Priapism may be present or not. The Authors report their experience on a penile metastasis secondary to prostatic cancer and about the evolution of this pathology. A review of the Literature is done.

Adenocarcinoma↗
PubMed1990

Cellular immune response to hepatitis B virus-encoded antigens in acute and chronic hepatitis B virus infection.

The proliferative response of PBMC to hepatitis B virus (HBV) envelope, core, and e Ag was analyzed prospectively in 21 patients with acute self-limited HBV infection and compared with the response of patients with chronic HBV infection and different levels of HBV replication (i.e., hepatitis e Ag (HBeAg)- or anti-HBe-positive) and liver damage (i.e., chronic active hepatitis or chronic asymptomatic carriers). Our results indicate that: 1) HBV-infected subjects who develop a self-limited acute hepatitis show a vigorous PBMC response to hepatitis B core Ag and HBeAg, as expression of T cell activation; 2) appearance of a detectable lymphocyte response to HBV nucleocapsid Ag is temporally associated with the clearance of HBV envelope Ag; 3) in patients with chronic HBV infection the level of T cell responsiveness to hepatitis B core Ag and to HBeAg is significantly lower than that observed during acute infection; 4) T cell sensitization to HBV envelope Ag in acute and chronic HBV infection is usually undetectable and when measurable is expressed transiently and at low levels. These results may reflect immune events of pathogenetic relevance with respect to evolution of disease and viral clearance.

Adult↗
PubMed1990

[Continent cecal-colonic reservoir. Surgical technique].

The Authors discuss a recent case report treated with radial cystectomy associated with a secondary urinary derivation using the caecum-colon reservoir. After having reviewed the various surgical procedures involving the urinary derivations, the Authors describe the technique used by them paying particular attention to the positive aspects of having a low filling pressure reservoir controlled by a valid sphincter ileum-caecum valve. Considering the good postoperative result with this method, the Authors regard this procedure as an alternative to other urinary derivation techniques when carried out with correct indications.

Aged↗
PubMed1990

The immunogold-silver staining approach in the study of lymphocyte subpopulations in transmission electron microscopy.

The potential of immunogold-silver staining has been evaluated in immunoelectron microscopic studies of human normal peripheral blood lymphocyte subpopulations. The cells were labeled, before being embedded in resin, using 5 nm colloidal gold particles and this was followed by silver enhancement. The use of colloidal gold particles permits detection of small amounts of antigen; the silver intensification forms a sphere of heavy metal around the gold granule giving rise to an ultrastructural marker which can be easily seen even at low magnification. The ultrastructural details of the cells were well preserved and there was no significant background staining. The major advantage of the present IGS technique is that it permits a rapid and simultaneous evaluation of both the immunophenotype and the ultrastructural characteristics of cells.

Gold↗
PubMed1990

Asymptomatic parathyroid adenoma manifested by intratumoral hemorrhage.

A 48-year-old woman whose past history was unrevealing presented with sudden swelling of the neck with pain and dysphonia. Neck ultrasonography suggested the possibility of hemorrhage in a parathyroid adenoma. Surgical exploration revealed a hemorrhagic parathyroid adenoma of the chief cell type. This event is exceedingly rare, but should be considered in the differential diagnosis of suddenly appearing masses of the neck region.

Adenoma↗
PubMed1990

Morphometric evaluation of CD16-positive cells with respect to CD2 antigen coexpression.

We examined morphometric as well as functional characteristics of CD16-positive human peripheral blood lymphocytes on the basis of the coexpression of the CD2 antigen. For morphometric analyses, nuclear area and cellular area were determined by counting line cross-points of a superimposed quadratic lattice test system overlying nuclei and the whole cell, respectively. Moreover, to evaluate the cellular villousity degree, the maximum inscrible circle and an irregular polygon were inscribed within cell profiles. The cytoplasm fraction included between the plasmalemma and the traced irregular polygon was considered as the villous portion of the cell. Finally, the NK capability was measured in a 6-hr 51Cr-release assay with human K-562 myeloid cells as targets. Within the CD16-positive cell population, the CD16-positive/CD2-negative cells seem to represent the most efficient NK cell subset. To the higher NK capability correspond a higher villousity degree and a lower nuclear area/cellular area ratio of the CD2-negative/CD16-positive subset, when compared with CD2-positive/CD16-positive cells.

Antibodies, Monoclonal↗
PubMed1990

Immunocytochemical localization and identification of prosomatostatin gene products in medullary carcinoma of human thyroid gland.

Thirty-three cases of histologically proven calcitonin-positive medullary thyroid carcinoma were studied immunocytochemically for the occurrence of prosomatostatin-related peptides. Positive cells, identified with a panel of antisera raised against four different regions of the prosomatostatin molecule, were found in 100% of the tumors. Most but not all somatostatin-positive cells were also immunoreactive for calcitonin. Notably, seven patients harboring somatostatin-rich tumors revealed a more favorable clinical course. The results (1) indicate that somatostatin production is a universal concomitant of thyroid medullary carcinoma, (2) suggest that these cells are likely to produce a somatostatin precursor molecule similar to mammalian prosomatostatin, and (3) imply that somatostatin-reactive cells may have as yet unknown roles in these tumors, possibly in the realm of paracrine and autocrine regulation of cell growth.

Adolescent↗
PubMed1990

Dopaminergic treatments for hyperprolactinaemia.

Hyperprolactinaemia is a frequent cause of anovulatory sterility, although spontaneous pregnancy may occur occasionally. Dopaminergic treatment is highly effective for the treatment of both idiopathic and tumoral hyperprolactinaemia. If the only cause of infertility is chronic anovulation due to hyperprolactinaemia, an 80% pregnancy rate can be anticipated. Because of these results, surgical treatment is still needed only rarely. Pregnancy, either spontaneous or drug-related, is usually uneventful for the mother and is not associated with any increase in abortion, twins or malformations. Pregnancy-related tumour growth occurs rarely and can be treated successfully with dopaminergic drugs. On the contrary, there is more frequently improvement after pregnancy of the biochemical and clinical disorders associated with hyperprolactinaemia.

Adolescent↗
PubMed1990

Effects of blood donation on cerebral blood flow velocity.

Eighteen healthy male blood donors, nine with hematocrit (Hct) of 0.40 to 0.45 (normal Hct) and nine with Hct of 0.49 to 0.52 (upper-limit Hct), were monitored by continuous-wave internal carotid Doppler sonography and hematologic tests for 28 days after blood donation, to ascertain whether and to what extent a single standard donation may modify the velocity of cerebral blood flow. The two groups had similar mean predonation values of internal carotid flow velocity (ICFV): blood donation was followed in both groups by a slight, transient decrease of ICFV at the end of phlebotomy, due to donation-induced hypovolemia, and then by an increase of ICFV lasting 7 to 10 days. Analysis of individual profiles revealed that only four of nine upper-limit and six of nine normal Hct donors displayed a positive trend (increase) in the ICFV within the first week after donation, and that it was due mainly to a rise in systolic flow velocity. Mean Hct and arterial oxygen content showed a negative trend (decrease) within the first week that was opposite to the ICFV trend. Other laboratory variables, including serum proteins and plasma fibrinogen concentration, and the iron status indicators did not change, except for serum ferritin, which also decreased within the first week after phlebotomy. It can be concluded that blood donation may result in a short-term increase of blood flow velocity that is independent of Hct predonation levels in approximately one-half of the donors.

Adult↗
PubMed1990

Role of a 90-kD glycoprotein in Heymann's nephritis.

Heymann's nephritis can be induced in rats by injection of antibodies (Ab) against the major nephritogenic antigen (Ag) (gp330). We previously reported on a 90-kD tubular-glomerular glycoprotein (gp90) having enzymatic activity (dipeptidyl-peptidase IV) which, after antibody interaction, induces a transient Heymann-like immunofluorescence pattern. In the present study we have analysed the ultrastructural features of the renal immune reaction occurring in rats after injection of a monoclonal antibody to gp90, revealed by a pre-embedding immunogold staining (5-nm particles). In the early stage (10-60 min) gold granules were found along the glomerular capillary walls mainly in the endothelial region. During the intermediate stage (24-48 h) the brush border microvilli were diffusely labelled. In the late stage (1-2 weeks) gold particles were still noticed at the tubular level. This work suggests that the immune reaction in Heymann's nephritis also occurs on the endothelial side of the glomerular capillary walls, thus facilitating the passage of epithelial-specific antibody. The tubular kinetics confirms that gp90 may play a role in the metabolic activity of tubular proximal cells. Because this antigen has been demonstrated in human kidney as well, it may be relevant to some membranous or other human nephropathies.

Animals↗
PubMed1990

Adhesion molecules on the plasma membrane of epidermal cells. II. The intercellular adhesion molecule-1 is constitutively present on the cell surface of human resting Langerhans cells.

The intercellular adhesion molecule-1 (ICAM-1), which is a member of the immunoglobulin superfamily, is expressed on many cell types, including a variety of cells showing accessory/antigen-presenting capacities and belonging to the monocyte/macrophage or dendritic lineages. Here it is shown that human freshly isolated Langerhans cells (LC) constitutively express ICAM-1, as expected. It seems likely that the amounts of ICAM-1 moieties expressed on the plasma membrane of resting LC are only limited, since they virtually escaped detection by conventional immunofluorescence procedures on epidermal sheets. However, all the observed Birbeck granule-bearing LC showed their clear, although relatively weak, ICAM-1 positivity when more sensitive techniques were employed, such as colloidal gold-immunoelectronmicroscopy using gold particles 15nm in size and, to an even higher extent, using gold particles 5 nm in size. Because ICAM-1 is a ligand for the adhesive molecule LFA-1, which is expressed on the surface of leukocytes and, especially, lymphocytes, the ICAM-1 (LC)/LFA-1 (T-lymphocytes) interactions might, enabling these cells to adhere together, deliver activation signals to T cells, thus constituting the initial event in the generation of a cutaneous immune response.

Cell Adhesion Molecules↗