B. Szabó

Neutralizing and complement-dependent enhancing antibodies in different stages of HIV infection

Reclustering and indirect immunofluorescence assays on MT-4 cells [carrying both CD4 and complement receptor type 2 (CR2)] were used to measure neutralizing and enhancing antibodies in sera obtained from HIV-1-infected individuals. Heat-inactivated sera were tested before and after mixing 1:1 with fresh seronegative human serum. Using heated samples, neutralizing antibodies were found in 20 out of 20 and 11 out of 19 serum samples of asymptomatic and symptomatic [AIDS, AIDS-related complex (ARC)] HIV-seropositive patients, respectively. In complement-restored samples, neutralizing activity was found in eight sera of asymptomatic patients and in none of the sera of AIDS and ARC patients; enhancing activity could be detected in four and 12 sera, respectively. A significant positive correlation was observed between the titres of neutralizing antibodies measured in the complement-restored samples and the absolute number of CD4+ lymphocytes. These findings indicate that the appearance of complement-dependent enhancing antibodies coincident with the loss of neutralizing antibodies may indicate a poor prognosis in HIV infection.

Restriction Enzyme Analysis of Ribosomal DNA Shows that Candida inconspicua Clinical Isolates Can Be Misidentified as Candida norvegensis with Traditional Diagnostic Procedures

ABSTRACT We identified 29 yeast isolates from 22 patients using the API ID32C panel. Twenty-eight of these isolates were Candida norvegensis and one was C. inconspicua. Although C. norvegensis is considered a pseudohypha-producing species, only one isolate produced pseudohyphae. Restriction enzyme analysis of PCR-amplified ribosomal DNA with four different enzymes proved that all isolates were C. inconspicua.

Caspofungin susceptibility testing of Candida inconspicua: correlation of different methods with the minimal fungicidal concentration.

ABSTRACT Minimal inhibitory and minimal fungicidal concentrations of caspofungin were determined for 48 Candida inconspicua isolates. By using CLSI (formerly NCCLS) methodology with the partial inhibition endpoint criterion, caspofungin exhibited a good fungicidal effect against C. inconspicua (the MIC90 was 0.25 μg/ml and the minimum fungicidal concentration [MFC] was 0.5 μg/ml after 24 h). Total inhibition yielded falsely elevated MICs, exceeding even the respective MFCs.

Synthesis and anti-HIV activity of a new hexopyranoside analogue of AZT

Abstract The glycosylation of thymine (13) with 12 in the presence of trimethylsilyl triflate promoter afforded the α, β-L-ribo-hexopyranosy1-nucleoside analogue 14a,b. After removal of the protecting group 1-(3-azido-2,3,6-trideoxy-α and β-L-ribo-hexopyranosyl) -thymine (15a and 15b) were isolated in anomerically pure form in a ratio of 1:20. The anti-HIV activity of the major product 15b was examined, in comparison with AZT, on H9 lymphoid cell-line.

Antiretroviral immune response and plasma interferon in different phases of chronic granulocytic leukemia.

Forty patients with chronic granulocytic leukemia (CGL) were tested for antibodies and lymphocytes reacting with gibbon ape leukemia virus (GaLV) and baboon endogenous virus (BaEV) antigens as well as for plasma interferon levels. Antibodies reacting with envelope antigens of GaLV and BaEV were found frequently and in high titers in patients with the quiescent phase of CGL but rarely and in low titers in the accelerated and blastic phase of the disease. Results of radioimmunoprecipitation studies were in concordance with those obtained in virus neutralization experiments. Cellular and humoral cytotoxic activity of blood plasma and lymphocyte samples against autologous tumor cells showed a similar phase-specific distribution. Most of these activities could be blocked by GaLV and BaEV gp70 antigens. Elevated plasma interferon (IFN)-alpha levels were found in the quiescent and accelerated phase of CGL, whereas no significant differences could be detected between IFN levels of patients with the blastic crisis of CGL and those of the control persons. Follow up studies of four patients confirmed this stage-specific distribution of antiretroviral immune and interferon response.

Impact of fertilization on the mineral nutrition and yield of Salix triandra x Salix viminalis and Robinia pseudoacacia L. bioenergy crops

Willow was cultivated as an energy crop in a field experiment. The brown forest soil was treated with an inorganic fertilizer (ammonium nitrate−AN: 100 kg ha -1 ) or with various organic or mineral soil amendments (municipal biocompost–MBC: 20 t ha −1 ; municipal sewage sludge compost–MSSC: 15 t ha −1 ; rhyolite tuff–RT: 30 t ha −1 ; willow ash−WA: 600 kg ha −1 ), or their combinations (AN+MBC; AN+RT; AN+WA, MSSC+WA) in four replications. Nineteen months after the soil treatments the macroelement-rich amendments (MBC, MSSC) enhanced the harvested fresh shoot yield most significantly (up to 41% as compared to the untreated control), and also the shoot diameter and shoot height of the willow plants. Most of the treatments enhanced the uptake of N (9.8-23.5%) and K in willow leaves, but the concentrations of P, Mg, Ca, Fe and Zn in the leaves were reduced. The toxic element (As, Cd, Pb) accumulation of willow shoots was negligible. In a 4-year field experiment the effects of the mineral fertilizers AN and AN+calcium-magnesium carbonate (CMC) were studied on the mineral nutrition of the leaves and wood yield of black locust trees cultivated as an energy crop. The brown forest soil was treated with 300 kg ha −1 annual doses of these fertilizers as top-dressing in June 2009, May 2010 and May 2011. Both fertilizers caused a three to four times increase in the nitrate content of the upper soil soon after their application in June. By the end of the vegetation period (in December) the nitrate concentration in the soil was similar to that in the control plots. The nitrogen content of the leaf stalks (petioles) and leaves, however, was only slightly higher in the treated plots. As a trend, fertilization increased the phosphorus and reduced the calcium uptake in the leaf stalks and leaves, while the magnesium content was not influenced. In March 2012, when the whole trees were harvested, 22% or 28% higher aboveground fresh shoot weight was detected in the AN or AN+CMC treatments than in the control.

Long-term field fertilization experiment with energy willow (Salix sp.) − Elemental composition and chlorophyll fluorescence in the leaves

A small-plot long-term field fertilization experiment was set up in 2011 with willow (Salix triandra x Salix viminalis ’Inger’) grown as an energy crop in Nyiregyhaza, Hungary. The brown forest soil was treated three times (in June 2011, May 2013, May 2016) with municipal biocompost (MBC), municipal sewage sludge compost (MSSC) or willow ash (WA), and twice (June 2011, May 2013) with rhyolite tuff (RT). In late May – early June 2016 urea (U) and sulphuric urea (SU) fertilizers were also applied to the soil as top-dressing (TD). These fertilizers and amendments were also applied to the soil in 2016 in the combinations; MBC+SU, RT+SU, WA+SU and MSSC+WA. All the treatments were repeated four times. In July 2016 the highest nitrogen concentrations in willow leaves were measured in the U (3.47 m/m%) and SU (3.01 m/m%) treatments, and these values were significantly higher than the control (2.46 m/m%). An excess of nitrogen considerably reduced the Zn uptake of the leaves, with values of 39.5 μg g -1 in the U treatment, 53.4 μg g -1 in the SU treatment, and 63.5 μg g -1 in the control. All other amendments or TDs, except for WA, enhanced the specific potassium concentrations in willow leaves compared to the control. No significant quantities of toxic elements (As, Ba, Cd, Pb) were transported from soil amendments or TDs to the willow leaves. In July 2016 the most intensive leaf chlorophyll fluorescence was observed in the MSSC and MSSC+WA treatments.