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Biomedical subjects

F Speranza

Publications and source records attributed to F Speranza.

At least 37 records · Page 2Linked to original sources
PubMed1996

Increased levels of nitrite in the sera of children infected with human immunodeficiency virus type 1.

Nitric oxide (NO) is a newly discovered gas that plays an important role in cell communication and host resistance to infection. The production of NO was examined in the sera of seven children infected with human immunodeficiency virus type 1 (HIV-1) and in the sera of 14 children who became seronegative for HIV-1 during the first year of life. In addition, we determined serum levels of various cytokines, such as interleukin (IL)-1 beta, tumor necrosis factor (TNF)-alpha, and gamma interferon (IFN-gamma), inasmuch as these cytokines are potent inducers of NO production. Production of NO, detected as circulating serum levels of nitrite, was measured with use of the Griess reagent. Serum levels of cytokines were determined by enzyme immunoassay. Increased serum levels of nitrite were observed in children with HIV-1 infection (0.4 +/- 0.2 mumol/L; P = .013), and in those who became seronegative for HIV-1 during the first year of life (0.5 +/- 0.3 mumol/L; P = .04). Furthermore, serum levels of IL-1 beta and TNF-alpha were significantly elevated in children with HIV-1 infection (37.5 +/- 23.6 pg/mL and 91.2 +/- 45.1 pg/mL, respectively). Prophylactic administration of intravenous immune globulin provoked a significant decrease of circulating levels of nitrite in children with HIV-1 infection. In conclusion, NO may play a role as a cytostatic or cytotoxic factor for invading microorganisms, and thus it is probably involved in limiting and/or eradicating infection.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Effects of recombinant murine (rm) interleukin-12 and rm interferon-gamma in mice infected with Bordetella pertussis.

The recombinant cytokines interferon (IFN)-gamma and interleukin (IL)-12 stimulate several macrophage-mediated functions that are important in host defense. An experimental pertussis model showed that intraperitoneal (i.p.) administration of 10,000 U of recombinant murine (rm) IFN-gamma to mice at the time of Bordetella pertussis infection caused a marked and significant reduction in the number of colony-forming units of bacteria in the lungs. Administration i.p. of 1 microgram of rmIL-12 or 1 microgram of rmIL-12 at the time of and for 5 consecutive days after B. pertussis challenge also induced a significant reduction in the number. However, i.p. administration of 1 microgram of rmIL-12 with 10,000 U of IFN-gamma at the time of B. pertussis challenge did not provide protection. These findings indicate that exogenous administration of rmIL-12 and rmIFN-gamma enhances resistance of mice to B. pertussis infection.

Animals↗
PubMed1996

Serum concentrations of nitrite in patients with HIV-1 infection.

AIMS: To measure circulating concentrations of nitrite in patients with HIV-1 infection. METHODS: Nitrite concentrations were measured using the Griess reaction adapted to microtitre plates in the serum of 10 asymptomatic HIV-1 positive patients, 33 patients with AIDS with cerebral disorders, 17 patients with AIDS with pulmonary involvement, and in eight patients with AIDS with other disorders. Nitrite concentrations were also measured in bronchoalveolar lavage (BAL) fluid and cerebrospinal fluid (CSF) of patients with AIDS with pulmonary involvement and cerebral disorders, respectively. RESULTS: Increased serum concentrations of nitrite were observed in patients with pulmonary involvement, and in particular in serum and in BAL samples of patients with interstitial pneumonia (36.2 (26.2) mumol/l and 0.3 (0.4) mumol/l, respectively). Increased serum concentrations of nitrite were also noted in patients with retinitis caused by infection with cytomegalovirus. Serum nitrite concentrations were also raised in patients with cerebral toxoplasmosis, whereas normal serum concentrations were found in patients with HIV-1 encephalopathy and cryptococcal meningitis. Nitrite concentrations in CSF were not raised in patients with cerebral disorders. CONCLUSIONS: These results suggest that production of nitrite in patients with AIDS with concomitant opportunistic infections may be part of the host defense against opportunistic organisms.

Adult↗
PubMed1996

Expression of the alpha 5 beta 1 fibronectin receptor on T lymphocytes of patients with HIV-1 infection.

AIMS: To evaluate the expression of the alpha 5 beta 1 integrin fibronectin receptor (FNR), which mediates several processes, including phagocytosis, cell motility and the immune response, on T lymphocytes of patients with HIV-1 infection. METHODS: T lymphocytes were incubated with monoclonal antibody directed against FNR and then with monoclonal antibodies, conjugated with phycoerythrin, directed against CD3, CD4 and CD8 positive cells. Expression of FNR on CD3, CD4 and CD8 positive cells was analysed using flow cytometry. RESULTS: Normal expression of FNR was observed on CD3 positive cells from asymptomatic HIV positive patients and those with AIDS. Increased expression of FNR was observed on CD8 positive cells from asymptomatic HIV positive patients and on CD4 positive cells from patients with AIDS. Increased FNR expression was observed on CD4 positive cells from patients with AIDS, particularly those with opportunistic infections caused by Pneumocystis carinii, Mycobacterium sp, Toxoplasma gondii, and Cryptococcus neoformans. CONCLUSION: Increased expression of FNR on CD8 and CD4 positive cells in asymptomatic HIV positive patients and those with AIDS, respectively, may be an epiphenomenon correlated with lymphocyte activation by HIV-1 or opportunistic infection, Further study is required to determine whether upregulation of FNR expression has a direct role in the pathogenesis of AIDS.

AIDS-Related Opportunistic Infections↗
PubMed1995

Characterization of proteins phosphorylated by the cAMP-dependent protein kinase of bovine heart mitochondria.

Characterization of two mitochondrial proteins of M(r) 42 and 18 kDa, respectively, phosphorylated by the cAMP-dependent protein kinase of bovine heart mitochondria (mtPKA), is presented. A 42 kDa protein is found to be loosely associated to complexes I, III and IV of the respiratory chain and complex V (ATP synthase) in the inner mitochondrial membrane. An 18 kDa protein is associated to complex I in the inner membrane and in a purified preparation of this complex where it can be phosphorylated by the isolated catalytic subunit of PKA.

Adenosine Triphosphatases↗
PubMed1995

Age-related changes in binocular vision: detection of noise-masked targets in young and old observers.

This study investigated the effects of age on binocular unmasking. This term denotes the fact that a visual signal embedded in noise is detected appreciably better when the stimulus complex contains interocular cues (dichoptic condition) than when such cues are absent (binoptic condition). Detection thresholds for two Gabor signals differing in spatial frequency were determined in young and old adults with no identifiable ocular pathologies. The signals were embedded, in both conditions, in two-dimensional Gaussian noise. Binocular Masking Level Differences, defined as the difference between the binoptic thresholds and the dichoptic thresholds, did not change with age; however, the older adults showed higher binoptic thresholds with both signals and higher dichoptic thresholds with only the lower-spatial-frequency signal. For both groups, binoptic and dichoptic thresholds increased with spatial frequency. The implications of these results are discussed.

Adult↗
PubMed1994

Effects of recombinant human gamma interferon on intracellular survival of Bordetella pertussis in human phagocytic cells.

Several studies have demonstrated that Bordetella pertussis has the ability to enter and survive intracellularly within human polymorphonuclear leukocytes (PMNL) and human monocytes/macrophages. The effects of human recombinant gamma interferon (IFN-gamma) on the survival of B. pertussis in PMNL and human monocytes, and on the oxidative burst activity of PMNL and human monocytes in response to B. pertussis were assessed in this study. IFN-gamma partially increased intracellular killing of phagocytosed B. pertussis in human monocytes, as determined by an orange acridine-crystal violet assay. In contrast, IFN-gamma did not enhance intracellular killing of B. pertussis in PMNL. No significant increase of superoxide production was noted in human monocytes in response to B. pertussis when stimulated with various concentrations of IFN-gamma. The partial increase of B. pertussis killing by IFN-gamma within monocytes, together with poor production of superoxide may explain how B. pertussis can survive within human phagocytic cells, and thus cause a more prolonged course of the disease.

Bordetella pertussis↗
PubMed1994

Levels of circulating fibronectin receptor in adult and pediatric patients with human immunodeficiency virus type 1 infection.

We found a significant increase in fibronectin receptor (FNR) levels in the sera of adult human immunodeficiency virus type 1 (HIV-1)-infected patients, especially in those with AIDS (1,026.9 +/- 583.9 ng/ml; P < 0.0001). In contrast, AIDS patients with neurologic disorders and HIV-1-seropositive patients showed normal levels of FNR in serum. In addition, HIV-1-infected children showed increased levels of FNR in serum (824.4 +/- 333.5 ng/ml; P = 0.03). We suggest that an increase of FNR levels in AIDS patients is related to enhanced expression of FNR on HIV-1-infected cells.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Effect of recombinant IL-1 beta and recombinant gamma interferon on septic acute lung injury in mice.

The effect of recombinant human interleukin 1B (IL-1B) and recombinant human gamma interferon (IFN-g), when given prophylactically, in a mouse model of septic acute lung injury was studied. Mice were treated with various doses of IL-1B and IFN-g for 3 consecutive days prior to administration of lipopolysaccharide of Escherichia coli (1 mg/kg given intraperitoneally). To determine the histologic changes occurring after prophylactic administration of such cytokines, a scoring system was assessed. A significant reduction of edema and neutrophil accumulation into the lungs of mice was observed, especially at doses of 100 U per mouse and 10,000 U per mouse of IL-1B and IFN-g, respectively. Prophylactic administration of IL-1B or IFN-g caused histologic changes, including marked reduction of edema and neutrophil accumulation in the interstitial and alveolar spaces. Combined prophylactic administration of IL-1B and IFN-g provoked a marked decrease of neutrophil accumulation into the lungs, but was not accompanied by significant reduction of edema or hemorrhage. These results provide evidence for the beneficial role of IL-1B and IFN-g in the abnormality of septic acute lung injury by reducing inflammatory lesions.

Animals↗
PubMed1993

Interferon-gamma levels in serum and bronchoalveolar lavage fluid of mice infected with Bordetella pertussis.

The adherence of Bordetella pertussis to respiratory cilia and its survival in neutrophils and macrophages is crucial to the pathogenesis of whooping cough. To investigate the role of endogenous interferon (IFN)-gamma in acute infection, levels of IFN-gamma in bronchoalveolar lavage (BAL) fluid of mice infected intranasally with B. pertussis were determined. Since pertussis toxin is released during infection by B. pertussis either locally or systemically, serum levels of IFN-gamma in mice injected intravenously with pertussis toxin were also determined. A persistent and significant increase of IFN-gamma levels with concomitant peripheral blood lymphocytosis was observed after 5 and 10 days. The results of this study showed an early but transitory production of endogenous IFN-gamma in BAL fluid of mice infected with B. pertussis.

Animals↗
PubMed1993

Production and release of tumor necrosis factor alfa, interleukin-1B and interleukin-6 by human mononuclear leukocytes stimulated with pertussis toxin.

Pertussis toxin (PT) has been previously shown to affect a wide variety of immune responses and to cause lymphocyte proliferation. In this study, we examined the effect of PT on cultured human peripheral blood lymphocytes and monocytes with the regard to the capability of this toxin to stimulate the production and release of various cytokines. PT was found to induce the production and release of Tumor Necrosis Factor alfa (TNF-alfa) and Interleukin-6 (IL-6) by both human lymphocytes and monocytes and IL-1 (IL-1B) beta by human monocytes in culture. Most activities of PT in vitro were achieved at the optimal concentration range of 1-0.01 microgram/ml, which is responsible for the adjuvant effect of PT in vivo. Since TNF-alfa, IL-1 beta and IL-6 are potent mediators of inflammation, the production and release of these cytokines by PT and Bordetella pertussis itself may play an important role in antibacterial defenses against such infection.

Cells, Cultured↗
PubMed1992

Ventriculoatrial shunt infection caused by Staphylococcus warneri: case report and review.

Staphylococcus warneri, a coagulase-negative species, is a rare cause of infection of cerebrospinal fluid (CSF) shunts. In one recently studied case of ventriculoatrial shunt infection, the repeated isolation of S. warneri (i.e., from all of six blood cultures and from a CSF sample obtained directly from the valve of the shunt) suggested that this organism can be clinically significant. Review of the literature clearly indicates that S. warneri is a rare but potentially dangerous pathogen in both immunocompetent and immunocompromised hosts with prosthetic devices. The removal of the infected shunt in association with systemic and local antibiotic administration probably constitutes the treatment of choice in such infections. Further experience is needed to determine the prevalence and the pathogenic significance of S. warneri and of the related organisms Staphylococcus epidermidis and Staphylococcus saprophyticus in patients with prosthetic devices.

Bacteremia↗
PubMed1992

Cerebrospinal fluid levels of IL-6 in patients with acute infections of the central nervous system.

Interleukin-6 (IL-6) activity was measured in the cerebrospinal fluid (CSF) of patients with acute bacterial or viral meningitis and in AIDS patients with various cerebral disorders. Increased levels of IL-6 were detected in the CSF of patients with bacterial meningitis. On the contrary, most of the samples from patients with viral meningitis (predominantly caused by mumps virus) had no detectable IL-6 activity in CSF. A moderate increase of IL-6 levels was detected in the CSF of AIDS patients with AIDS dementia complex (ADC), progressive multifocal leukoencephalopathy and cerebral toxoplasmosis. Moreover, higher levels of IL-6 were detected in the CSF of patients with cryptococcal meningitis. We conclude that the initial events of CSF inflammation in patients with acute viral meningitis are different from those in patients with acute bacterial meningitis, and the role of IL-6 is less critical to the process.

AIDS Dementia Complex↗
PubMed1991

Cerebrospinal fluid concentration of fibronectin in meningitis.

Fibronectin concentrations in the cerebrospinal fluid were assessed in 20 patients with acute meningitis using a turbidimetric immunoassay. A significant increase in fibronectin concentrations was observed in patients with bacterial meningitis; decreased concentrations were observed in patients with viral meningitis. The determination of fibronectin concentration in patients with bacterial meningitis may represent a useful marker in differentiating bacterial from viral meningitis.

Acute Disease↗