In vitro and in vivo induction of nitric oxide by murine macrophages stimulated with Bordetella pertussis.

Nitric oxide (NO) exhibits potent antimicrobial activity in vitro. The function of NO in host defenses in vivo, however, is presently unclear. Experiments were undertaken to determine the production of NO in vitro from murine peritoneal and alveolar macrophages, and murine macrophage cell line (J774A.1) stimulated with Bordetella pertussis or pertussis toxin (PT). In addition, we determined circulating levels of NO in the sera and bronchoalveolar lavage (BAL) fluids of mice infected intranasally with B. pertussis. The results of this study showed that in vitro murine peritoneal macrophages induce production of NO in response to B. pertussis and PT. In addition, murine macrophage cell line, J774A.1 also induces NO production after stimulation with B. pertussis. NO production was also detected in alveolar macrophages from mice infected intranasally with B. pertussis. Finally, a significant increment of circulating levels of NO was noted, in the sera but not in the BAL fluids, of mice infected intranasally with B. pertussis.

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.

Circulating fibronectin and fibronectin receptor in children with pertussis.

AIM: To determine concentrations of fibronectin and fibronectin receptor in children with pertussis. METHODS: Concentrations of circulating fibronectin and serum fibronectin receptor were detected in eight children affected by pertussis, eight children with acute upper or lower respiratory tract infections, and in 14 healthy control children. The single radial immunodiffusion technique and a solid phase enzyme immunoassay were used to detect circulating serum concentrations of fibronectin and fibronectin receptor. RESULTS: On admission, a significant decrease in fibronectin was detected in children with pertussis (p = 0.0006). Significant and decreased concentrations of fibronectin were also observed in children with upper or lower respiratory tract infections (p = 0.0002). On the other hand, serum fibronectin receptor concentrations were significantly increased in patients with pertussis, whereas patients with upper or lower respiratory tract infections had normal circulating fibronectin receptor concentrations. CONCLUSIONS: Fibronectin deficiency in children with pertussis may be related to diffusion and deposition of this protein in bronchial and alveolar spaces to limit infection, while increased fibronectin receptor concentrations are probably the expression of T cell activation and cell-mediated immunity during Bordetella pertussis infection.

Aseptic meningitis caused by Leptospira australis.

Meningeal involvement in leptospiral infection is quite common, usually mild and often overlooked. In contrast, cases of isolated involvement of the central nervous system, including aseptic meningitis, have been reported only rarely. A case of a patient with acute aseptic meningitis caused by Leptospira australis serovar bratislava is reported. This is believed to be the first report of aseptic meningitis due to Leptospira australis. This case indicates the need to consider human leptospirosis in the differential diagnosis of aseptic meningitis.

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.

Serum levels of interleukin-1 alpha, interleukin-1 beta, interleukin-6, and tumor necrosis factor in patients with acute viral hepatitis.

Serum levels of interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) in patients with acute viral hepatitis were investigated. Twelve patients suffering from acute viral hepatitis were studied; 8 patients presented with acute hepatitis B, 2 patients with acute hepatitis A, and 2 patients with acute hepatitis C. Serum levels of IL-1 alpha, IL-1 beta, IL-6, and TNF-alpha were significantly increased in all patients with acute viral hepatitis. Decreased serum levels of all cytokines were noted in four patients with acute hepatitis B during the recovery phase of infection. In addition, IL-1 alpha, IL-1 beta, IL-6, and TNF-alpha were undetectable at the end of a follow-up period of 6 months. Our study shows that increased levels of IL-1 alpha, IL-1 beta, IL-6, and TNF-alpha are probably related to hepatitis activity and thus may have some role in hepatocytic injury.

Cerebrospinal fluid concentration of fibronectin in patients with HIV-1 infection and central nervous system disorders.

AIMS: To evaluate the fibronectin concentrations in the cerebrospinal fluid of HIV-1 infected patients with central nervous system disorders. METHODS: Fibronectin was determined by an immunoturbidimetric assay in 41 HIV-1 infected patients with AIDS dementia complex, progressive multifocal leucoencephalopathy, and opportunistic infections. RESULTS: A significant decrease in fibronectin concentrations in the cerebrospinal fluid of patients with AIDS and dementia complex and progressive multifocal leucoencephalopathy was observed, as well as in those with opportunistic infections of the central nervous system (p < 0.0001). In particular, a significant decrease in fibronectin concentration in cerebrospinal fluid was observed in patients with cerebral toxoplasmosis and cryptococcal meningitis (p < 0.0001). CONCLUSIONS: Because fibronectin can bind to several viruses, fungi, and protozoa, it is conceivable to suppose that the consumption of fibronectin in the cerebrospinal fluid of patients with neurological disorders may be related to the binding of fibronectin to HIV itself, or to viral proteins, or to organisms responsible for opportunistic infections.