The protonated forms of six amino acids (glycine, l-alanine, l-tryptophane, l-histidine, l-methionine and l-lysine) were ion-exchanged into Na-montmorillonite. A comparison of the FT-IR spectra of the host, the guests and host–guest substances revealed that the guest ions were intercalated successfully. It was verified by X-ray diffractometry and surface measurements as well. The spatial arrangement of the guest ions was modeled by semiempirical quantum chemical method. The intercalated organic ions provide chiral environment within the layers of the host material.

Cu(amino acid) complexes were immobilised in montmorillonite or on silica gel by two methods (i) cation exchange first followed by ligation (two-step method) or (ii) depositing the ligands onto/into the support, then introducing the metal ion and, finally, filling the empty coordination sites of the central ions by added ligands (three-step method). The amino acids were l-tyrosine, l-histidine or l-aspartic acid. Immobilisation was followed by infrared spectroscopy. Host–guest substances were formed in every Cu2+–amino acid– montmorillonite system, however, significant anchoring occurred on silica gel only when tyrosine was the ligand. The heat stabilities of these host–guest substances were appreciable, complete decomposition only occurred at 673 K.

It was shown that adsorbed hydrogen-rich carbonaceous residues could be formed on zeolites, but, when the temperature was not too high, they were typical only for unsaturated hydrocarbons. The overlayer then mainly contained alkenyl carbenium ions of various length. They were detected on the zeolite surface by UV–Vis spectroscopy. In the formation of these ions both Brønsted and Lewis acid centres played significant role. The unsaturated carbenium ions provided additional Lewis acid sites participating in hydride ion abstraction. The formation of alkenyl carbenium ions started at temperature as low as 298 K for butadiene. When n-butane, a saturated hydrocarbon, was the model, adsorbed hydrogen-rich carbonaceous residues were not found even at adsorption temperature as high as 473 K.

Synthetic hectorite (laponite) was prepared and pillared by partially hydrolyzed Al, Zr and Cr salts. The synthesis of the host material as well as its pillaring was successful. The samples were treated in various ways and were characterized by X-ray diffractometry, Fourier-transform infrared spectroscopy and BET surface area measurements. It was found that the pillared structure survived calcination at 773K making these materials potential shape selective catalysts up to this temperature.

The Fermi resonance phenomenon, generally appears in the liquid and gas phase spectra of benzoyl chloride, has been preserved also in the adsorbed phase. However, the resonance proved to be less complete. The resonance parameters could be calculated since the ν(C–Cl) was experimentally observed due to the optical window in the spectrum of the faujasite skeleton. The term diagram also proves a weaker resonance in the adsorbed phase than in the liquid phase.

Adsorption and decomposition of chlorofluorocarbon (CFC-12) in different zeolites were studied by means of IR and multinuclear NMR spectroscopies, X-ray diffraction and scanning electron microscopy. It is shown that the decomposition of CFC-12, is simultaneously accompanied by the destruction of zeolite structure. Consequently, the decomposition of CFC-12 should be regarded as a chemical reaction with the zeolite rather than a catalytic transformation.

Acidity of amorphous sol–gel aluminum silicates containing transition metals was investigated by using FT-IR spectroscopy. The composites were prepared from metal alkoxides using diols as complexing agent. The samples were characterized by XRD, SEM, TEM, thermal analysis and BET surface measurement. Pyridine was used as probe molecule for the IR acidity measurements. H2 treatment enhances the amount of both Brönsted and Lewis acid sites in Al-containing samples, but has no significant effect on pure silica matrices. Lewis acidity is primarily determined by the type and amount of transition metals incorporated into the composite.

Vladimir Krcméry, MD, Limbová, 3, SL–81103 Bratislava (Slovakia) Sir, During the last years many yeasts and yeast-like organisms previously considered as saprophytes have been reported to cause systemic infections, especially after bone marrow transplantation or with acute leukemia. There are 23 cases of Hansenula spp infections described up to date; 19 were fun-gemias, in 17 cases associated with catheter infection, but only 2 described within the last 7 years [1-4]. We describe breakthrough Hansenula anomala fungemia despite prevention with fluconazole in a leukemic female during reinduc-tion chemotherapy and neutropenia. A 46-year-old female with acute myelogenous leukemia (AML) was admitted with a relapse of AML received chemotherapy with VP-16 120 mg/m2 days 1-5 and mitoxan-trone 12 mg/m2 days 1-3. On the 1st day of antineoplastic chemotherapy a central venous (jugular) catheter was inserted. On day 3 of chemotherapy, the patient had a fever of 38.5 °C and received empirically ciprofloxacin, piperacillin (for therapy) and fluconazole 400 mg/ day intravenously (as a prophylaxis). On day 6 of the therapy the patient was afebrile, but on day 10 a fever of 39 ° C again appeared and the therapy was modified to ceftazidime, netilmicine and fluconazole intravenously. No pathogen was isolated until day 10. On the same day three blood cultures were drawn and 2 days later they showed positivity for H. anomala in all three cultures obtained through a peripheral vein susceptible to fluconazole, amphotericin B and miconazole. The catheter could not be removed because of severe trombo-cytopenia and bleeding on from the oral cavity (5 trombocytes/ml). The patient was also neutropenic on day 5, and on the day of fungemia (day 12 of antibiotic therapy) she had 50 neutrophils/ml and was neutropenic on the next 10 days (less than 500 neutrophils/ml). Intravenous amphotericin B in a daily dose of 1 mg/kg was given but 2 and 5 days later blood cultures were again positive for H. anomala. This organism was identified with the Vitek Junior system and confirmed microscopically. After 5 cultures were positive fore yeasts after the administration of three trombocyte concentrates the catheter was extracted and replaced with a new jugular catheter despite deep trombopenia (5/mm3) and the risk of bleeding. Surprisingly, the catheter tip was negative for both fungi and bacteria. On day 9 of fungemia, despite persisting neutropenia the patient was afebrile. There was no evidence of a complication of the fungemia (CT scan of CNS, ultrasound of liver, ophthalmoscopy negative, echocardiography negative). On day 10 of fungemia, antibiotics were

Background. Ferroptosis is a recently identified cell death pathway, and the susceptibility to ferroptosis inducers varies among cancer cell types. There have been recent attempts to clarify the mechanisms implicated in ferroptosis, glioma invasion, and the immune microenvironment but little is known about ferroptosis regulation in GBM. Methods. Screening ferroptosis-related genes from published reports and existing databases, we constructed an integrated model based on the RNA-sequencing data in GBM. The association of FRGPRS and overall survival is identified and validated across several different datasets. Genomic and clinical characteristics, immune infiltration, enriched pathways, pan-cancer, drug resistance, and immune checkpoint inhibitor therapy are compared among various FRGPRS subgroups. Results. We identified and confirmed the influences of five ferroptosis key hub genes in the FRGPRS model. The FRGPRS model could serve to predict overall survival and progression-free survival in GBM patients, and high FRGPRS was associated with comparatively stronger immunity, higher proportions of tumour tissue, and good cytolytic immune and chemotherapeutics response in GBM patients. Conclusions. The five ferroptosis key hub genes constituting the FRGPRS model could serve to predict overall survival and progression-free survival in patients with GBM and help guide timely and efficacious therapeutic strategies customised and optimised for each individual patient. This discovery may lay the foundation for the development and optimisation of other iterations of this model for the improved forecasting, detection, and treatment of other malignancies notorious for their drug resistance and immune escape.

During the 5-year period 1989-1993, the incidence of Candida krusei, and other non-albicans Candida spp., was analyzed in a 60-bed cancer department. The frequency of C. krusei, before fluconazole was introduced into therapeutic protocols in 1990, was 16.5%, and after introduction of fluconazole into prophylaxis in acute leukemia in 1991, the incidence of C. krusei was 12.7%. After 3 years of using this drug in therapy and prophylaxis, the incidence of C. krusei in 1993 was 14.8%, what was lower than before this drug was introduced in our country. 97.6% of all isolated fungi were yeasts and only 2.4% were molds. Among yeasts, the most frequently isolated pathogen was Candida albicans with 64.3% in 1989 and 74.2% in 1993. The next was C. krusei with 21.2% in 1992 and 16.5% in 1989, but 14.8% in 1993, and Candida tropicalis and Candida glabrata with 9.03% in 1989 and 2.7% in 1993. Among the molds, Aspergillus spp. was the most frequently isolated genus. Analyzing the etiology of mycologically proven fungal infections confirmed by positive blood cultures or biopsies, C. albicans and Aspergillus spp. were the most common causative organisms.

20 patients with proven or suspected fungal infections were treated with the amphotericin B lipid complex (ABLC) with a daily dose of 5 mg/kg for 1-25 days. 6 patients died during the therapy due to fungal infection (3) or underlying disease (3). One patient was not evaluable. 13 patients were cured and improved. ABLC was administered in patients with renal disese avoiding the use of conventional amphotericin B (AmB) because of nephrotoxicity or after failure with AmB. Except for hypokalemia persisting after AmB in 5 patients, no systemic adverse reaction appeared. ABLC is a promising, well-tolerated and effective drug for the therapy of fungal infections after the failure of a previous antifungal therapy or after toxic reactions due to AmB.

In a comparative randomized trial, teicoplanin 5 mg/kg plus either netilmicin 5 mg/kg or pefloxacine 10 mg/kg was administered in a once daily empiric therapy to 40 cancer patients with fever and neutropenia after cytotoxic chemotherapy. Both regimens were analyzed with respect to the localisation of the underlying disease, catheter presence and agents isolated from blood culture. The cure and improvement rate were 80% (teicoplanin plus netilmicin) and 85% (teicoplanin plus pefloxa-cin), with no statistically significant difference between the groups. Teicoplanin with either an aminoglycoside or a quino-lone administered once daily seems to be a suitable approach in empiric therapy for fever in neutropenia and may prevent catheter insertion in cancer patients.