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Biomedical subjects

L Fontana

Publications and source records attributed to L Fontana.

At least 109 records · Page 6Linked to original sources
PubMed1990

Mortality from specific causes among silicotic subjects: a historical prospective study.

A historical mortality study was conducted among 520 silicotic subjects diagnosed at the Department of Occupational Health of the San Martino Hospital, Genoa, Italy, between 1961 and 1980. Vital status was ascertained as of 1 January 1982. Age-, sex- and calendar-year-adjusted standardized mortality ratios (SMRs) for specific causes were computed using Italian as well as Genoa County male population death rates. The study shows statistically significant increased mortality from all deaths (SMR = 2.92), all cancers (SMR = 2.38), respiratory tract cancers (SMR = 6.85), respiratory tract diseases (SMR = 13.63), and from 'other diseases' (SMR = 6.81). The excess mortality from respiratory tract diseases and from 'other diseases' are mainly attributable to silicosis and silicotuberculosis, respectively. These findings confirm the existence of a causal association between silicosis and increased mortality from both malignant and non-malignant respiratory tract diseases. The high mortality from respiratory tract cancers was still present even after adjustment for smoking.

Adult↗
PubMed1990

[Thymopentin as adjuvant therapy in the hepatitis B vaccination of non- or hyporesponsive subjects].

The efficacy of thymopentin as adjuvant therapy was assessed in 13 people who did not respond to standard anti-hepatitis B vaccination with Pasteur HEVAC or Merck HV-VAX. Thymopentin (Sindtomodulina, Italfarmaco)--was given in doses of 50 mg 3 times a week for 3 consecutive weeks, a booster dose of the vaccine (40 mcg HB VAX injected into the deltoid muscle, or 10 mcg HEVAC subcutaneous) being given at the start of the second week. In 69.23% of the patients whose anamnesis revealed no immune deficiency, the Merrieux Multitest showed defective cell-mediated immunity. The adjuvant treatment produced an adequate immune response to the vaccine (anti ABc antibody titre 10 mU/ml) in 76.9% of cases and normalised cell-mediated immunity in 66.6% of those found to be hypoanergic at basal screening.

Adjuvants, Immunologic↗
PubMed1989

Complement activation is associated with the presence of specific human immunodeficiency virus (HIV)-anti-HIV immune complexes in patients with acquired immunodeficiency syndrome-related complex or lymphoadenopathy syndrome.

The complement system was examined in a group of eight patients (six with lymphoadenopathy syndrome (LAS); two with acquired immunodeficiency syndrome (AIDS)-related complex (ARC], who were found to be human immunodeficiency virus (HIV)-positive, for the presence of specific HIV-anti-HIV complexes. A significant impairment of the classical and/or alternative pathway was found associated with the presence of cleavage fragments of C3 and/or B and a significant reduction in the complement factors studied. Ultracentrifugation fractions of serum samples obtained from one of the patients were assessed for the detection of specific HIV-anti-HIV (GP41-anti-GP41) complexes and were incubated with normal human serum to determine their complement activation capacity. A clear complement activation was found with the fraction in which a clear peak of HIV-anti-HIV (GP41-anti-GP41) immune complexes was present. The results demonstrate that specific immune complexes and complement activation are sometimes concomitantly present in patients with AIDS-related disease and that specific immune complexes may be one of the causal factors of the pathogenesis of complement activation in these patients. Possible consequences for the severe immune regulation with relevance to the dramatic failure in treating the virus effectively are discussed.

AIDS-Related Complex↗
PubMed1989

Deficiency of lymphocyte lectin-dependent cytotoxicity in myelodysplastic syndromes.

We studied a group of patients with myelodysplastic syndromes (MDS) for surface markers and cytotoxic activities of peripheral blood mononuclear cells (PBMNC). The results indicate a significant increase in the total count of CD11b+, Leu7+ and CD16+ with a percent reduction in CD4+. A reduction in PHA-induced cellular cytotoxicity (PHA-ICC) and NK activity were found. A similar phenotype was found both in refractory anemia (RA) and (RA) with excess of blasts (RAEB/RAEB-t). However, the functional activities reached the normal level only in RA patients; while in RAEB/RAEB-t patients a significant reduction was detected in PHA-ICC and NK activity.

Aged↗
PubMed1988

Natural killer activity from normal peripheral blood lymphocytes against a human T lymphotropic retrovirus type III (HTLV-III)-infected cell line.

An H9-HTLV-III-infected cell line was used as a target in a short-term (3-hr) Cr release assay to assess its sensitivity to lysis by peripheral blood lymphocytes (PBL) from normal donors. The single cell cytotoxicity assay (SCCA) on poly-L-lysine-coated coverslips was used to investigate further the mechanism of binding and killing. Uninfected H9 and K562 cell lines were studied as controls. Our results argue in favour of a natural killer (NK) mechanism being operative on an H9-HTLV-III-infected cell line owing to the following findings: (1) the cell line is sensitive to lysis in a short-term assay; (2) its sensitivity is significantly higher than K562; and (3) the kinetics of lysis, as assessed by SCCA, is similar to that of K562, with a more efficient killing being detectable against H9-HTLV-III. Furthermore, a phenotypic analysis of effector cells suggests that CD4+ lymphocytes are also involved in the lysis of this target. Our data provide evidence for an immune mechanism that may be operative in HTLV-III infection. We then studied, by this method, five groups of patients: one (n = 20) affected by acquired immunodeficiency syndrome (AIDS), one (n = 20) by AIDS-related complex (ARC), one (n = 20) by lymphadenopathy syndrome (LAS), one group (n = 40) of HTLV-III seropositive, apparently healthy people, and one (n = 40) of healthy HTLV-III seronegatives.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Complex↗
PubMed1987

Surface markers and cytotoxic activities of lymphocytes in monoclonal gammopathy of undetermined significance and untreated multiple myeloma. Increased phytohemagglutinin-induced cellular cytotoxicity and inverted helper/suppressor cell ratio are features common to both diseases.

To determine whether monoclonal gammopathy of undetermined significance (MGUS) resembles multiple myeloma (MM) with regard to phenotype and functional activity, 16 patients with MGUS and 16 with untreated MM were studied for surface markers and cytotoxic activities phytohemagglutinin-induced cellular cytotoxicity (PHA-ICC), antibody-dependent cellular cytotoxicity, natural killer (NK) activity. Our data showed a consistent immunological similarity between the two diseases. An increase in OKT8+ cells was evident in both patient groups and a significant reduction in the T4/T8 ratio, more pronounced in MM, was observed. Alterations in NK activity or ADCC were not found in MGUS or MM. A significant increase in PHA-ICC was demonstrated in the two diseases. The increase in PHA-ICC observed seems to be attributable to an increased frequency and/or lytic efficiency of PHA-ICC lymphoid effector cells. These data suggest that similar immunological alterations are common to the two diseases. The greater helper/suppressor ratio reduction observed in MM seems to be related to the more severe clonal proliferation in these patients.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1987

Modulation of human concanavalin A-induced lymphocyte proliferative response by physiological concentrations of beta-endorphin.

The effects of physiological concentrations of beta-endorphin on the proliferative response to concanavalin A of human peripheral blood mononuclear cells from a large series of healthy donors are reported. These effects are also compared with those obtained employing beta-endorphin and phytohemagglutinin under the same experimental conditions. The donors (32), aged between 20 and 48 years, chosen among military personnel of the Italian Air Force, underwent clinical and laboratory investigations to exclude any detectable disturbance in their psychophysical fitness. Our results show that beta-endorphin is not mitogenic per se and is unable to modify the response of mononuclear cells to phytohemagglutinin irrespective of the concentration of opioid or mitogen used. beta-Endorphin is also unable to alter the PBMC response to low concentrations of concanavalin A, but significantly increases such a response when higher concentrations of concanavalin A and concentrations of beta-endorphin similar to those found in human plasma under physiological conditions are used. The effect is not reverted by naloxone, the specific opiate antagonist. When the activity of beta-endorphin on the mononuclear cell response to concanavalin A is examined at the single donor level, it is noted that some of the donors fail to show the opioid-dependent increase. The baseline levels of the response to concanavalin A of such subjects, compared to those of the donors whose response is augmented by the opioid, are significantly higher, thus demonstrating that beta-endorphin can selectively modulate concanavalin A-induced mitogenesis with a behavior depending on the individual characteristics of the donor's response. The process involves non-opioid cell receptors.

Adult↗
PubMed1987

A double-blind placebo controlled evaluation of the safety and efficacy of vinpocetine in the treatment of patients with chronic vascular senile cerebral dysfunction.

In a double-blind clinical trial, vinpocetine, a synthetic ethyl ester of apovincamine, was shown to effect significant improvement in elderly patients with chronic cerebral dysfunction. Forty-two patients received 10 mg vinpocetine three times a day (tid) for 30 days, then 5 mg tid for 60 days. Matching placebo tablets were given to another 42 patients for the 90 day trial period. Patients on vinpocetine scored consistently better in all evaluations of the effectiveness of treatment including measurements on the Clinical Global Impression (CGI) scale, the Sandoz Clinical Assessment-Geriatric (SCAG) scale, and the Mini-Mental Status Questionnaire (MMSQ). There were no serious side effects related to the treatment drug.

Aged↗
PubMed1987

Evidence for activation of complement in patients with AIDS related complex (ARC) and/or lymphoadenopathy syndrome (LAS).

The complement system was examined in 16 patients with AIDS-related complex (ARC) (n = 5) and/or lymphoadenopathy syndrome (LAS) (n = 11). Of these patients 62.5% showed an impairment of classical and/or alternative pathway activity associated with the presence of cleavage fragments of C3 and/or B and a significant reduction of many complement factors. The data indicate pathological complement activation in these patients through the classical and/or alternative pathway. Complement activation was more severe in patients with ARC than in those with LAS, and greater in drug abusers than homosexuals. The lack of efficient complement in the patients can be considered an 'acquired complement deficiency' with possible importance in the failure to combat the HIV attack.

AIDS-Related Complex↗
PubMed1986

Hairy cell leukemia: preliminary results with alpha 2 (r) interferon.

Ten patients with hairy cell leukemia are being treated at our institution with a therapeutic schedule of alpha 2(r) interferon (2 X 10(6) IU/m2 s.c. three times per week). Five patients underwent splenectomy from 4 to 108 months before treatment; nonsplenectomized patients had spleens palpable 6 to 12 cm UCM. According to Quesada's response criteria, at the sixth month of therapy, one patient was considered a complete responder, 8 partial responders and one a minor responder, with no differences between splenectomized and nonsplenectomized patients. In nonsplenectomized patients the spleen returned to normal. Our data confirm that interferon, even at low dosages, is a very effective approach for hairy cell leukemia. No evidence was found to contraindicate such therapy.

Adult↗
PubMed1986

Decreased NK activity in hairy cell leukemia (HCL): an analysis at the cellular level.

Peripheral blood lymphocytes (PBL) of eleven patients with Hairy Cell Leukemia were studied for surface phenotype and for NK activity against the K 562 cell line (using both the standard 51Cr Release Assay and the Single Cell Cytotoxicity Assay on poly-L-lysine coated coverslips). A significant reduction in NK activity, target binding cells (TBC) and NK active cells (NKa) was detected. In some cases however, despite a very low percentage of NKa, residual NK activity was observed, suggesting an efficient recycling capacity.

Adult↗
PubMed1986

Deficiency of natural killer activity, but not of natural killer binding, in patients with lymphoadenopathy syndrome positive for antibodies to HTLV-III.

Blood lymphocytes (BL) of eleven patients with lymphoadenopathy syndrome (LAS) were studied for natural killer (NK) activity against the K562 cell line (using both the standard 51Cr release assay and the single-cell cytotoxicity assay on poly-L-lysine-coated coverslips) and for surface phenotype (employing OKT4, OKT8 and Leu7 monoclonal antibodies). A significant reduction in NK activity and in NK active cells was detected, while the percentage of target binding cells was not affected. Furthermore, the OKT4/OKT8 ratio was found to be inverted, and the Leu7+ subpopulation expanded. The patients had high titers of anti-HTLV-III antibodies. This study indicates that defective NK activity in LAS is secondary to an abnormality in the lytic event itself and not in target binding.

Adult↗
PubMed1985

Human semen inhibits T rosette formation through an opiate mediated mechanism.

Seminal plasma contains high levels of opioid peptides and both seminal plasma and endogenous opioids can influence the immune system. In order to investigate whether these two findings can be related, semen was collected from 7 normal subjects, and assayed for beta-endorphin content and for its in vitro ability to inhibit the total T rosette formation of human lymphocytes in the presence or in the absence of 10(-6) M naloxone, an universal opiate antagonist. The results were as follows: 1) immunoreactive beta-endorphin content in seminal plasma was 4 to 12 times higher than the peripheral plasma levels detected in the same subjects (76.1 +/- 42.1 SD vs 10.5 +/- 2.0 SD pg/ml); 2) increasing concentrations of seminal plasma (1%, 5%, and 10%) in RPMI 1640 significantly depressed the T rosette formation ability of lymphocytes; and 3) the simultaneous addition to the incubation mixture of 10(-6) M naloxone prevented the phenomenon, while naloxone per se was ineffective. The possibility that endogenous opioids may play a role in the immunomodulatory action of human semen is suggested.

Adult↗
PubMed1985

Lymphocyte subpopulations and cell mediated cytotoxicity in acute non-lymphoid leukemia (ANLL) patients in complete remission (CR) and off-therapy.

An assessment of the lymphocyte sub-populations and cell mediated cytotoxicity was made in 12 adults with acute non-lymphoid leukemia after stopping chemotherapy. No significant differences were found between ANLL and controls, for absolute lymphocyte count, %SIg/+ cells, Fc gamma + cells and ERFC. The OKT4+/OKT8+ was reduced in ANLL. Leu-7+ cells were significantly higher in ANLL. Moreover it appears that in ANLL lymphocyte function is restored early after stopping chemotherapy.

Acute Disease↗