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Biomedical subjects

M Ricci

Publications and source records attributed to M Ricci.

At least 217 records · Page 12Linked to original sources
PubMed1983

Abnormalities of in vitro immunoglobulin synthesis by peripheral blood lymphocytes from untreated patients with Hodgkin's disease.

The immunoglobulin-synthesizing activities of peripheral blood mononuclear cells from 57 untreated patients with Hodgkin's disease and 47 normal subjects were compared. Cumulative amounts of IgM and IgG synthesized and secreted by unstimulated and pokeweed mitogen-stimulated cells over a 7-d period were determined in a solid-phase radioimmunoassay. Synthesis of IgM in unstimulated cultures and of both IgM and IgG in cultures stimulated with pokeweed mitogen was markedly reduced in patients with Hodgkin's disease, whereas the mean level of the spontaneous IgG synthesis was enhanced. The degree and frequency of in vitro abnormalities were not influenced by disease stage or histology. Depression of pokeweed mitogen-induced immunoglobulin synthesis did not correlate with excessive number of monocytes and it was unaffected by removal of phagocytic cells or addition to the cultures of monocytes from normal individuals. On the other hand, monocytes isolated from blood of patients with Hodgkin's disease were even more effective than normal monocytes in supporting pokeweed mitogen-induced immunoglobulin synthesis by normal phagocyte-depleted mononuclear cells. Synthesis of both IgM and IgG induced by pokeweed mitogen remained subnormal after addition to patient B cell cultures of autologous irradiated T cells or allogeneic normal T lymphocytes. T cells from patients with Hodgkin's disease appeared at least as effective as normal T cells in helping pokeweed mitogen-induced immunoglobulin production by normal B cells. However, when normal T cells were co-cultured with B cells from patients with Hodgkin's disease, spontaneous IgG synthesis declined, whereas the addition of patient T cells to normal B cells resulted in an increase of spontaneous IgG synthesis. In patients showing depression of pokeweed mitogen-induced immunoglobulin synthesis the lymphoproliferative response and immunoglobulin synthesis stimulated by Staphylococcus aureus bacteria of the Cowan first strain, a T cell independent B cell mitogen, were also markedly reduced. These studies demonstrate impairment of immunoglobulin synthesis by cultured lymphocytes from untreated patients with Hodgkin's disease after stimulation with polyclonal B cell activators and suggest that the in vitro abnormalities may be, at least in part, the result of a preexisting in vivo activation of lymphocytes in Hodgkin's disease patients.

Adolescent↗
PubMed1983

[Acute viral hepatitis in the Florence area: I. Epidemiologic study].

The sera of 401 patients admitted to the Department of Infectious Diseases [U.S.L. (Unità Sanitaria Locale) 10 D] in Florence in one year were screened for the presence of markers of hepatitis A and B viruses. On the basis of clinical and serological data, the diagnosis of viral hepatitis was confirmed for 302 patients. Among the se, 73 (24.18%) were affected by hepatitis A, 182 (60.26%) by hepatitis B and 47 (15.56%) by nonA nonB hepatitis. The prevalence of B nonA nonB hepatitis in 133 drug addicts was 69.37% and 25.51% respectively. A previous infection with hepatitis A virus, as demonstrated by the presence of anti A antibodies of the IgG idiotype in the sera, was demonstrated in 201 of 328 patients (62.03%) not affected by hepatitis A. Only 14% of them reported data related to a possible former acute hepatitis. Markers of B virus were found in 62 of 167 sera of patients (37.12%) not affected by acute B hepatitis or chronic HBsAg positive hepatitis. However the prevalence of virus B markers increases up to 50% in the sera of drug addicts. According to our data the spreading of virus hepatitis in the area of Florence is similar to that observed in other Regions of Central and Northern Italy with fairly good social and hygienic conditions. High prevalence of nonA nonB hepatitis and of HBsAg carriers among the drug addicts are noteworthy.

Acute Disease↗
PubMed1983

IgE synthesis in vitro induced by T cell factors from patients with elevated serum IgE levels.

The effect of unstimulated T cell culture supernatants (TCS) from patients with atopic dermatitis and high serum IgE levels on the IgE production in vitro by B cell rich suspensions from normal individuals or grass pollen sensitive patients with mild atopy was evaluated. TCS from patients with raised IgE enabled B cell suspensions from normal individuals to produce detectable amounts of IgE and potentiated the spontaneous IgE synthesis in vitro by B cell suspensions from grass sensitive patients. In contrast, the addition of TCS from normal subjects with low serum IgE levels did not increase or even reduced IgE synthesis by B cell cultures. When the same B cell cultures were analysed for their ability to produce IgG or IgM protein, no significant differences were observed. These findings indicate that T lymphocytes from patients with high serum IgE levels can release soluble factor(s) possessing isotype (IgE) specific potentiating activity.

B-Lymphocytes↗
PubMed1983

[Acute viral hepatitis in the Florence area: II. Immunologic study].

Sera obtained from 302 patients with acute viral hepatitis were studied for the presence of organ and non organ specific autoantibodies and of circulating immune complexes (CIC). Autoantibodies were determined by indirect immunofluorescence techniques and CICs were detected by 125 J - C1q assay (C1qBA according to Zubler et al., 1976). A high prevalence of anti smooth muscle autoantibodies (SMA) was found in the sera of the patients. In particular, SMA were found in the sera from 44/73 (60.2%), 92/182 (50.55%) and 10/47 (21.3%) of A, B and nonA nonB hepatitis, respectively. The highest prevalence of SMA was observed within 10 days after the clinical onset of the disease in hepatitis A patients and within 10-15 days in nonA nonB hepatitis. The prevalence of SMA in hepatitis B is persistently high during the first two weeks of illness, then decreases and, about the 3rd week, increases again. CIC were detected in 156 sera from 302 patients (51.65%) affected by acute viral hepatitis. The prevalence of CIC was significantly higher in hepatitis A (78.08%) than in B and nonA nonB hepatitis (45.6% and 34.03% respectively). CIC were demonstrated in almost all the sera of hepatitis A patients admitted between the 6th and the 15th day after the onset of the disease. A strict connection was observed between SMA and CIC and, although to a lesser extent, between CIC and markers of A and B viruses. No significant connection between CIC and serum aminotransferase or bilirubin levels was noted. CIC screening was performed weekly for 1 month after admission in 225 patients with acute viral hepatitis. According to our data, the clearance of immune complexes from serum seems to occur more quickly in B and nonA nonB hepatitis than in virus A hepatitis.

Acute Disease↗
PubMed1982

[Recent medico-social aspects of arterial hypertension].

The medical and social importance of hypertension, its symptoms and complications are presented. The factors of risk are examined and in particular the importance of premature onset of the hypertension in the youth is stressed. Since in teen-agers suffering from hypertension, it is probable that this disease worsen in the adult age, the necessity of a correct diagnosis and treatment also in the youth is pointed out.

Adult↗
PubMed1982

Phenotypic and functional characterization of a Sézary cell.

We have studied the surface antigen pattern, enzymatic phenotype, and functional capacity of peripheral blood lymphocytes from a patient with Sézary syndrome (SS). The majority of these cells formed E rosettes but lacked the Fc(mu) receptor. The neoplastic cells were reactive with pan-T cell (OKT3)- and helper T cell (OKT4)-subset monoclonal antibodies; however, they lacked the 5/9 antigen, which identifies a more restricted subset of helper T cells. Most SS cells also reacted with PTF 29.12, a monoclonal antibody which recognizes DR determinants. Only 35% of the cells expressed single, focal accumulations of alpha-naphthyl-acid esterase activity, which is a characteristic of T.M cells, but 85% of them showed this focal staining pattern with acid phosphatase or beta-glucuronidase. Mononuclear cells from the SS patient showed poor or no proliferative response to phytohemagglutinin, pokeweed mitogen, concanavalin A, purified protein derivative, Candida, and allogeneic cells and lacked both helper and suppressor activity for pokeweed mitogen driven production of IgM and IgG immunoglobulins by normal B cells, but they were able to stimulate a marked proliferative response in mixed-lymphocyte culture. The defective expression of enzymatic and surface membrane characteristics, together with the lack of some T-cell functions, suggests that the patient cells may be immature T.M lymphocytes.

Aged↗
PubMed1982

Protein A reactivity of lymphocytes from some patients with chronic lymphocytic leukaemia mediated by an interaction with the F(ab')2 region of surface immunoglobulin.

Peripheral blood lymphocytes (PBL) from 15 of 38 patients with chronic lymphocytic leukaemia (CLL) were capable of forming rosettes with human erythrocytes coated with staphylococcal protein A (SpA-HRBC). PBL from seven patients also showed a marked proliferative response after stimulation with Staphylococcus aureus bacteria strain Cowan I (Cowan Staph). The SpA-rosetting of CLL cells was inhibited by incubation with F(ab')2 fragments of anti-immunoglobulin (Ig) antibodies. In addition, incubation with these fragments inhibited the proliferative response of leukaemic B cells to Cowan Staph. The Cowan-Staph induced proliferation of CLL cells was also impaired by the addition of normal human IgG and human IgG F(ab')2 fragments to the cultures, whereas non-immune rabbit IgG was not inhibitory. The inhibitory activity of human IgG F(ab')2 fragments was retained by a SpA-Sepharose column, and it was found in the material recovered from the same column by acid elution. These data indicate that an interaction between SpA and a structure located in the F(ab')2 region of surface Ig of different classes is responsible for either SpA-binding or the Cowan-Staph-induced proliferative response of PBL from some patients with CLL.

Animals↗
PubMed1982

In vitro production of IgE by human peripheral blood mononuclear cells. III. Demonstration of a circulating IgE-bearing cell involved in the spontaneous IgE biosynthesis.

The presence of surface membrane IgE (SmIgE)-bearing cells in the peripheral blood (PB) of atopic patients was investigated by the use of isotype-specific rosettes of human red blood cells coupled to immunosorbent-purified rabbit or monoclonal mouse antibodies against human IgE (R or M anti-epsilon-HRBC). After dissociation of cell bound IgE by treatment with acid buffer, 2.1 +/- 0.3% and 1.2 +/- 0.3% circulating non-T, non-phagocytic, cells from atopic patients were still capable of forming rosettes with R or M anti-epsilon-HRBC, respectively. IgE molecules detectable on cells after dissociation of cytophilic IgE were quite resistant, like surface membrane IgM (SmIgM), to treatment with proteolytic enzymes, but they were removed under capping conditions by soluble anti-IgE antisera. All SmIgE-bearing (IgE+) cells also bore DR determinants, but many of them lacked SmIgM. Depletion of IgE+ cells strongly reduced the ability of PB lymphocyte suspensions from atopic patients to produce spontaneously IgE protein in vitro. Likewise, depletion of cells bearing DR determinants (DR+ cells) resulted in a marked decrease of the spontaneous IgE biosynthesis, whereas depletion of SmIgM-bearing (IgM+) cells had no effect. These data suggest that cells mainly implicated in the spontaneous IgE production in vitro seen in atopic patients are DR+ IgE+ IgM- circulating lymphocytes.

Antibodies, Monoclonal↗
PubMed1982

In vitro production of IgE by human peripheral blood mononuclear cells. IV. Modulation by allergen of the spontaneous IgE antibody biosynthesis.

Peripheral blood lymphocytes (PBL) from a proportion of grass-sensitive patients, studied during or immediately after the grass pollination period, showed spontaneous production in vitro of grass-specific IgE antibody, whereas PBL from atopic patients sensitive to allergens other than grass pollens or non-atopic individuals did not. Pre-incubation of IgE antibody producing PBL from grass-sensitive patients with minute amounts of a mixed grass pollen (MGP) extract or Rye grass antigen Group I (Rye I) usually resulted in a reduction of the spontaneous production in vitro of IgE protein and in a marked inhibition of the spontaneous production in vitro of grass-specific IgE antibody. This antigen-specific inhibition was not mediated by T lymphocytes, but it was apparently due to a signal directly delivered by antigen to the spontaneously IgE antibody producing cells. The results support the concept that the activity of cells responsible for the persistent IgE antibody formation in vitro in atopic patients can be modulated by antigen.

Antibody Specificity↗
PubMed1981

Surface immunoglobulins are involved in the interaction of protein A with human B cells and in the triggering of B cell proliferation induced by protein A-containing Staphylococcus aureus.

The nature of surface components responsible for the reactivity of a subset of human B cells with staphylococcal protein A (SpA) was studied. The ability of normal non-T cells or non-T cells from patients with chronic lymphocytic leukemia (CLL) to form rosettes with human red blood cells coated with SpA (SpA-HRBC) was strongly inhibited or abolished by incubation with F(ab')2 fragments of antibodies against human immunoglobulin (Ig), whereas the incubation with F(ab')2 fragments of antibodies against a non-Ig cell surface antigen, such as beta 2-microglobulin, had no effect on the SpA-rosetting of human lymphocytes. The role of the reaction between surface Ig (sIg) and SpA in the triggering of the proliferative response induced by Staphylococcus aureus bacteria strain Cowan I (Cowan Staph) on normal or leukemic non-T cells was also investigated. A parallelism was observed between the mitogenic activity on normal human non-T cells of Cowan Staph and F(ab')2 fragments of immunosorbent-purified rabbit antibodies to human mu-chain. On the other hand, monovalent Fab fragments of anti-F(ab')2 or anti-mu chain antibodies were unable to activate human non-T lymphocytes, but usually induced a partial inhibition of the Cowan Staph-induced cell proliferation. Non-T cells from 2 patients with CLL did not respond to either Fab or F(ab')2 fragments of anti-Ig antibodies, but were stimulated to proliferate by Cowan Staph. However, the proliferative response of non-T cells from these patients to Cowan Staph was markedly inhibited or abolished by the addition to the cultures of F(ab')2 fragments of anti-Ig antibodies. Antibody preparations to human F(ab')2 or gamma-chain inhibited the response of IgG-bearing leukemic cells, whereas the Cowan Staph-induced proliferation of IgM-bearing leukemic lymphocytes was inhibited by the addition to the cultures of either anti-F(ab')2 or anti-mu chain antibodies. The proliferative response to Cowan Staph or normal non-T cells was also inhibited by the addition to the cultures of human and guinea pig polyclonal IgG, whereas IgG from other species, such as goat, ox, horse, and rabbit, were poorly or not at all inhibitory. On a molar basis, the F(ab')2 preparation from human IgG was as potent an inhibitor as intact IgG molecules, whereas Fc gamma was much less effective in inhibiting the Cowan Staph-induced cell proliferation. A monoclonal IgM, isolated from the serum of a patient with CLL, whose lymphocytes were able to form rosettes with SpA-HRBC and to proliferate in vitro after stimulation with Cowan Staph, also showed a marked inhibitory activity on the Cowan Staph-induced proliferation or normal non-T cells. These data suggest that an interaction between SpA present on the bacterial cell wall and a structure located in the Fab region of sIg, which is shared by sIgM, sIgG, and perhaps also by sIg of other classes, plays an important role in the triggering of B cell proliferation induced by SpA-containing staphylococci.

Antibodies↗
PubMed1980

Short- and long-term effects of radiation on T-cell subsets in peripheral blood of patients with Hodgkin's disease.

The present study was undertaken to determine the effect of radiotherapy on subpopulations of peripheral blood T cells from patients with Hodgkin's disease. T cell were purified from each specimen, and proportions and absolute numbers of T lymphocytes bearing receptors for the Fc portion of IgG (TG) and for Fc portion of IgM (TM) were enumerated by rosetting T cells with ox red blood cells (ORBC), which had been coated with anti-ORBC rabbit IgG or IgM, respectively. In untreated patients, the percentage of TG cells was significantly increased, and the percentage of TM cells was significantly decreased when compared with control values. In patients examined after radiotherapy, there was a severe depletion of total T lymphocytes. The percent and absolute values of TM cells were also markedly decreased in comparison with those found in either normal controls or untreated patients. In contrast, relative proportions of TG cells were significantly increased in the same treated patients, but the absolute numbers of these cells were essentially unchanged in comparison with those found before radiation therapy. There was a partial and progressive restoration of the number of TM lymphocytes some years after the treatment, but reduced percentages of TM lymphocytes and increased percentages of TG lymphocytes were still found in patients in continuous complete remission for at least five years or more. Similar alterations of the two T-cell subsets were also found in the peripheral blood of a small group of patients treated with radiation for testicular seminoma. These data clearly demonstrate that radiation therapy has a differential effect on identifiable and distinct subsets of cells in the human T-cell class.

Adult↗
PubMed1980

[The plaster cast syndrome 2 cases of intestinal gastric emphysema].

Two clinical cases of acute gastric dilatation (Cast syndrome) in wearers of surgical corsets for kyphoscoliosis are described. One patient died in spite of surgical treatment, whereas the other responded favourably to conservative management. Fifty cases from the literature are examined. The seriousness and rapid progression of the syndrome are clear from its persistently high mortality (22%). Treatment was conservative in 70% of cases: antishock therapy, nasogastric aspiration, removal of the cast, while duodenojejunostomy was performed in the other 30%. In the two cases described, the seriousness of gastric distress due to compression of the duodenum by the aorta and mesentery was furthered evident from the observation of interstitial gastric emphysema.

Adolescent↗