CA19-9 serum levels predict micrometastases in patients with gastric cancer.

BACKGROUND: We explored the prognostic value of the up-regulated carbohydrate antigen (CA19-9) in node-negative patients with gastric cancer as a surrogate marker for micrometastases. PATIENTS AND METHODS: Micrometastases were determined using reverse transcription quantitative polymerase chain reaction (RT-qPCR) for a subgroup of 30 node-negative patients. This group was used to determine the cut-off for preoperative CA19-9 serum levels as a surrogate marker for micrometastases. Then 187 node-negative T1 to T4 patients were selected to validate the predictive value of this CA19-9 threshold. RESULTS: Patients with micrometastases had significantly higher preoperative CA19-9 serum levels compared to patients without micrometastases (p = 0.046). CA19-9 serum levels were significantly correlated with tumour site, tumour diameter, and perineural invasion. Although not reaching significance, subgroup analysis showed better five-year survival rates for patients with CA19-9 serum levels below the threshold, compared to patients with CA19-9 serum levels above the cut-off. The cumulative survival for T2 to T4 node-negative patients was significantly better with CA19-9 serum levels below the cut-off (p = 0.04). CONCLUSIONS: Preoperative CA19-9 serum levels can be used to predict higher risk for haematogenous spread and micrometastases in node-negative patients. However, CA19-9 serum levels lack the necessary sensitivity and specificity to reliably predict micrometastases.

Submerged cultivation of Ganoderma lucidum and the effects of its polysaccharides on the production of human cytokines TNF-α, IL-12, IFN-γ, IL-2, IL-4, IL-10 and IL-17.

An original strain of Ganoderma lucidum (W.Curt.:Fr.) Lloyd, MZKI G97 isolated from Slovenian habitats was grown by a submerged liquid substrate cultivation in a laboratory stirred tank reactor. Five fractions of extracellular and cell-wall polysaccharides were obtained by extraction, ethanol precipitation, and purification by ion-exchange, gel and affinity chromatography. The capacity of isolated polysaccharide fractions to induce innate inflammatory cytokines, and to modulate cytokine responses of activated lymphocytes was investigated. Human peripheral blood mononuclear cells (PBMC) were activated in vitro with polysaccharide fractions, in order to induce innate inflammatory cytokines: tumor necrosis factor alpha (TNF-α), interleukin (IL) 12 and interferon gamma (IFN-γ). For the immunomodulation capacity, polysaccharide fractions were cultured with ionomycine and phorbol myristate acetate (IONO+PMA) activated PBMC, and the concentrations of induced IL-2, IL-4, IFN-γ, IL-10 and IL-17 were measured. The results showed that polysaccharides from G. lucidum induced moderate to high amounts of innate inflammatory cytokines. Fungal cell-wall polysaccharides were stronger innate inflammatory cytokines inducers, while extracellular polysaccharides demonstrated a higher capacity to modulate cytokine responses of IONO+PMA induced production of IL-17. The results indicate that G. lucidum polysaccharides enhance Th1 response with high levels of IFN-γ and IL-2, and display low to no impact on IL-4 production. A similar pattern was observed at regulatory cytokine IL-10. All of the polysaccharide fractions tested induced IL-17 production at different concentration levels.

In vivo modulation of Campylobacter jejuni virulence in response to environmental stress.

Campylobacters have developed a number of mechanisms for responding to environmental conditions, although the different virulence properties of these cells following exposure to stress are still poorly understood. We analyzed in vitro stress responses and the consequent in vivo modulation of Campylobacter jejuni pathogenicity in BALB/c mice, as a result of the exposure of the C. jejuni to environmental stress (starvation, oxidative stress, heat shock). In vitro, the influence of starvation and oxidative stress was milder than that of heat shock, although the majority of the stress conditions influenced the survival of C. jejuni. During starvation, C. jejuni viability was maintained longer than its culturability. Additionally, starvation elicited transformation of stressed bacteria to coccoid forms. In contrast, bacteria exposed to oxygen remained culturable, but their viability decreased. Pre-starvation did not contribute to improved survival of C. jejuni cells during oxygen exposure. Changes in bacteria numbers and the levels of several cytokines (interleukins 6 and 10, tumor necrosis factor-α, interferon-γ) were followed in vivo, in liver homogenates from the mice intravenously infected with either control (untreated) or stressed C. jejuni. The systemic infection with the control or stressed C. jejuni occurred with different production dynamics of the cytokines investigated. Starvation was the most powerful stress factor, which significantly decreased infectious potential of C. jejuni during the first 3 days postinfection. The most pronounced differences in cytokine production were found in interferon-γ and interleukin-10 production, which indicates that these have roles in the immune response to C. jejuni infection. These in vivo studies of environmental impact on bacterial virulence reveal that microbial adaptation during stress challenge is crucial not just for pathogen survival out of the host, but also during host-pathogen interactions, and thus for the bacterial pathogenicity.