Interferon gamma production in the course of Mycobacterium tuberculosis infection.

It is not clear why some individuals with unknown predisposition develop tuberculosis, while others remain healthy in spite of heavy exposure. Interferon gamma (IFNgamma) is considered to be the key cytokine responsible for resistance to M. tuberculosis infection, as confirmed by increased susceptibility to mycobacterial infections in rare inherited defects in IL-12-IFNgamma axis. The aim of this study was to assess the IFNgamma production by peripheral blood lymphocytes from immunocompetent tuberculosis (TB) patients. The study group included 51 TB patients. In all cases, TB was confirmed by culture. Twenty healthy TB contacts were considered as control group. Commercially available ELISA-based assays were used to measure IFNgamma in the supernatant of whole blood cell cultures after stimulation with PWM (Phytolacca Americana), PHA (phytohemagglutynin), and PPD (purified protein derivative). No difference in IFNgamma secretion between the patients and control group was found when blood cells were stimulated by PWM or PHA. PPD-induced IFNgamma formation was higher in TB patients than in controls. The secretion of IFNgamma after non-specific stimulation varied in different clinical and radiological presentation of tuberculosis and it was lower in most advanced and extensive forms of the disease. It is unclear whether the difference in formation and release of IFNgamma is a primary or secondary phenomenon in the course of the disease.

Heterogeneity of antibody response to myobacterial antigens in different clinical manifestations of pulmonary tuberculosis.

Different clinical outcomes of tuberculosis can be related to the balance between cell-mediated and humoral immunity. In this prospective study we examined the humoral immune responses to recombinant and native mycobacterial antigens in relation to clinical presentations of pulmonary TB. Two hundred and fifteen serum samples were examined including: non-cavitary (n=120), cavitary (n=65), caseous pneumonia (n=12), and disseminated TB (n=18). ELISA tests detecting IgG, IgA, and IgM against antigens: 38 kDa and 16 kDa, 38 kDa and lipoarabinomannan (LAM) were used. Univariate and multivariate logistic regression analyses were carried out to find the association between the antibody level and demographic or clinical characteristics. The relationships among specific antibody profiles and the phase of the disease in relation to demographic (age and sex) and clinico-radiological factors were investigated by measuring serum antibody levels (IgG, IgA, and IgM) to 38 kDa and 16 kDa recombinant M. tuberculosis antigens and to LAM - native mycobacterial antigen. The results show that the radiological extent of the disease is the strongest factor associated with IgG antibody production. Patients with more extensive pulmonary TB showed higher titers of IgG antibody to M. tuberculosis antigens (P<0.0001). The highest IgG and IgA level were observed in fibro-cavernous TB. The presence of cavity was associated only with IgG anti 38+16 kDa (P<0.001). IgA level was the highest in caseous pneumonia. IgM antibody production was not associated with any clinical and radiological factor, but only with the male gender. Age was independently and inversely associated with IgG anti 38 kDa+LAM level and IgM anti 38 kDa+LAM. We conclude that the humoral immune response to mycobacterial antigens is highly heterogeneous and varies with the stage of TB. IgG antibody level is higher in most advanced and extensive forms of the disease.

A 13-week comparison of passive and continuous ozone monitors at forested sites in north-central Pennsylvania.

Ogawa passive O3 samplers were used in a 13-week study (June 1-September 1, 1999) involving 11 forested and mountaintop sites in north-central Pennsylvania. Four of the sites were collocated with TECO model 49 O3 analyzers. A significant correlation (p < 0.0001) was found for 24-hr average weekly O3 concentrations between the two methodologies at the four sites with collocated monitors. As expected, there were positive relationships between increasing elevation of the sites and increasing O3 concentrations. No O3 exposure patterns were found on a west-to-east or south-to-north basis; however, the area known for lower O3 exposures within a smaller subsection of the study area showed consistently lower O3 exposures. Preliminary results regarding relationships of symptom responses within O3-sensitive bioindicators are also presented with black cherry (Prunus serotina, Ehrh.) and common milkweed (Asclepias syriaca, L.) showing clear evidence of increasing injury with increasing O3 exposures. Due to the extremely dry conditions encountered in north-central Pennsylvania during the 1999 growing season, O3-induced symptoms were sporadic and quite delayed until late-season rains during the latter portion of the observation period.

Chiroptical properties of binuclear rhodium complexes of lanostane alcohols.

The circular dichroism (CD) of the in situ-formed Rh2(OCOCF3)4 complexes of sterically hindered, secondary lanostane alcohols was investigated. The main object of the present studies are derivatives of 3beta-, 7alpha-, 7beta-, and 11beta-hydroxylanostanes with or without an additional functional group, e.g., double bond, oxo-, hydroxy-, or acetoxy groups. Up to five Cotton effects (CEs) can be found in the CD spectra of Rh-complexes of these alcohols in the spectral range between 650-300 nm. Correlation of the CEs signs with the absolute stereochemistry at the carbon atom bearing the hydroxy group was investigated. The Rh-complex with the 3beta-acetoxylanostan-11beta-ol ligand was isolated in the crystalline form. Its polymeric structure, determined by the X-ray method, shows the di-Rh-units linked by the axially ligating oxygen atoms of the hydroxy and acetoxy groups. In the latter case, the coordination takes place through the carbonyl oxygen.