The Warburg effect: a score for many instruments in the concert of cancer and cancer niche cells

Although Warburg's discovery of intensive glucose uptake by tumors, followed by lactate fermentation in oxygen presence of oxygen was made a century ago, it is still an area of intense research and development of new hypotheses that, layer by layer, unravel the complexities of neoplastic transformation. This seemingly simple metabolic reprogramming of cancer cells reveals an intriguing, multi-faceted nature that may link various phenomena including cell signaling, cell proliferation, ROS generation, energy supply, macromolecules synthesis/biosynthetic precursor supply, immunosuppression, or cooperation of cancerous cells with cancer-associated fibroblasts (CAFs), known as reversed Warburg effect. According to the current perception of the causes and consequences of the Warburg effect, PI3K/Akt/mTOR are the main signaling pathways that, in concert with the transcription factors HIF-1, p53, and c-Myc, modulate the activity/expression of key regulatory enzymes, including PKM2, and PDK1 to tune in the most optimal metabolic setting for the cancer cell. This in turn secures adequate levels of biosynthetic precursors, NADPH, NAD⁺, and rapid ATP production to meet the increased demands of intensively proliferating tumor cells. The end-product of "aerobic glycolysis", lactate, an oncometabolite, may provide fuel to neighboring cancer cells, and facilitate metastasis and immunosuppression together enabling cancer progression. The importance and possible applicability of the presented issue are best illustrated by numerous trials with various agents targeting the Warburg effect, constituting a promising strategy in future anti-cancer regimens. In this review, we present the key aspects of this multifactorial phenomenon, depicting the mechanisms and benefits behind the Warburg effect, and also pointing to selected aspects in the field of anticancer therapy.

Current status of fungal cell wall components in the immunodiagnostics of invasive fungal infections in humans: galactomannan, mannan and (1-->3)-beta-D-glucan antigens

Early diagnosis of fungal infections and the implementation of appropriate treatment represent major issues for clinicians, nowadays. Histopathological demonstration of microorganisms in tissue specimens or growth of fungal agents in culture media is still considered the "gold standard", but obtaining such specimens may be difficult. Several groups have investigated serological assays for cell wall elements unique to fungal organisms in serum or other body fluids to improve diagnostics in patients with haematological malignancies or undergoing haematopoietic stem-cell transplantation. In this review we have concentrated on the currently available assays allowing for detection of highly immunogenic components of fungal cell wall: galactomannan, mannan, and also (1-->3)-beta-D-glucan. Rapid serological tests appear to be useful for screening high-risk haematological patients, since they allow for the early diagnosis of invasive fungal infections, including infections with the most common pathogens such as Aspergillus and Candida. Based on current literature, factors increasing the probability of obtaining false-positive or false-negative results detected by each test were also analysed and tabulated.

[Compliance to treatment recommendations in patients with obstructive sleep apnea at least one year after diagnosis]

102 OSA patients, qualified for nCPAP treatment at least one year ago were investigated by questionnaire and direct examination. CPAP device has been used by 76 patients (75%). Other subjects (26 persons) did not use it for various reasons. Subjects treated (Group L) and not treated (Group NL) were compared. Before qualifying for nCPAP treatment, Group L compared to Group NL, had significantly higher apnoea/hyponoea index, AHI (p < 0.001) and more severe hypoxaemia during sleep (p < 0.01). Subjects of Group L were more obese (p < 0.01) and smoked more cigarettes per day (p < 0.05) than Group NL. Group L patients have been using nCPAP for 6.3 +/- 0.2 nights per week and 6.4 +/- 0.2 hours per night. From variables characterizing OSA and obesity, the intensity of nCPAP usage positively correlated with AHI (p < 0.05) and negatively with severity of daytime sleepiness (p < 0.001). Among Group L patients, 93% reported general improvement, 84% woke up refreshed and rested in the morning and 70% did not feel sleepy during the daytime. Concentration improved in 66% of treated patients. Main complaints were associated with rhinitis (38%), uncomfortable mask (34%) or air leaks around the mask (26%), dryness in throat and nose (33%), shallow, unquiet sleep with frequent awakenings (about 31%), chest pain (23%) or headache (22%). 33% of subjects complained of machine noise, troubling sleep partner.

CONCLUSIONS

The acceptance of nCPAP treatment was 75% and depended on the OSA severity. nCPAP device was effective in OSA treatment, mild side effects were reported by around one third of studied patients.

[Hospital acquired pneumonia--analysis of frequency and etiology in Polish hospitals in 1998]

Hospital-acquired pneumonia (HAP) is one of the most frequently occurring hospital infections in the world. This study describes the incidence of HAP in Poland, as well as the specific risk factors leading to this type of infection in Polish hospitals; including those of patient age, length of hospitalization, and use of mechanical ventilation. The epidemiology of HAP as well as treatment resistance of various causal organisms was studied. Data for this study was acquired from the Registry of Hospital-acquired Infectious Diseases for the year 1998. Out of 329,608 hospital-acquired infections in all patients except newborns, 920 were found to be HAP. This study showed that of every 1000 hospital admissions three patients developed HAP (0.3%). Death occurred in 260 of 920 HAP cases or 30%; and HAP found to be the direct cause of death in 66 of the 260 cases (25%). The greatest incidence of HAP was found to occur in patients older than 75 years, was directly related to the length of hospital stay, and was higher in patients on mechanical ventilation longer than 10 days. The most frequently isolated causal agents were the Gram-negative rods (Pseudomonas aeruginosa, Acinetobacter sp., Klebsiella sp., Enterobacter sp.), and Staphylococcus aureus. Streptococcus pneumoniae and Haemophilus influenzae were found in only 2% and 4% of cases, respectively, and thus were the least likely causes of HAP in this population. It was found that the percentage of methicillin-resistant strains of Staphylococcus aureus was very high (55% to 60%); vancomycin-resistant enterococci were only found in patients who did not undergo surgery. The isolated strains of Pseudomonas aeruginosa showed marked resistance to chinolones (58-76%) and to imipen (approximately 20%). In the Enterobacteriaceae family, Klebsiella sp. was found to be resistant to third-generation cephalosporins (56-73%) and Enterobacter sp. resistant in 55% to 81% of the isolates.

[The effect of long-term therapy of obstructive sleep apnea syndrome with CPAP for symptoms of daytime sleepiness]

The study was undertaken to investigate whether a long-term CPAP therapy improves the symptoms of daytime sleepiness in patients with the obstructive sleep apnoea syndrome. Seventy six patients (72 men and 4 women) with AHI = 53(+/- SE = 3), BMI 35 (+/- SE = 0.8), mean age 46.3 (+/- SE = 11.4) have undergone CPAP therapy for at least one year (mean: 2.48 +/- SE = 0.33). The aggravation of alterations of the daytime sleepiness was estimated using the questionnaire from Sleep Laboratory at the Marburg University and the Epworth Sleepiness Scale (ESS). After the CPAP therapy, we have observed the decrease of the symptoms of the excessive daytime sleepiness (p < 0.001). Negative correlation between CPAP compliance and ESS outcome was observed (r = 0.4; p < 0.001). There was not correlation between the term of using CPAP and the degree of the complaints decrease.