Treatment of chronic myeloid leukemia with autologous transplantation using peripheral blood stem cells or bone marrow cultured in IL-2 followed by IL-2, GM-CSF,and IFN-alpha administration

Interleukin-2 (IL-2) is able to generate nonspecific cytotoxic effectors from hematopoietic precursors. We evaluated the feasibility and efficacy of chronic myeloid leukemia (CML) treatment with autologous hematopoietic stem cell transplantation (HSCT) using grafts cultured in IL-2 followed by immunotherapy with IL-2, granulocyte-macrophage colony-stimulating factor (GM-CSF), and interferon (IFN)-α. Eight patients with CML were enrolled: five in an accelerated phase and three in a chronic phase. They received peripheral blood stem cells (PBSC) or bone marrow (BM) cultured in a medium containing IL-2 for 24 h. A median of 1.29 × 10⁶ CD34+ cells/kg were infused after conditioning with busulfan (12–16 mg/kg) in PBSC recipients. BM was infused without prior myeloablative therapy. The engraftment occurred with a median of 15 d. Engraftment failure developed in one patient. The transplantation was followed by a 1-mo regimen of IL-2 (0.5 × 10⁶ IU/m² daily) and GM-CSF, and 6 mo of IFN-α. One complete and one transient minor cytogenetic remission were observed. At 24 mo after transplantation, two patients had died of progressive disease and one of infection. Five patients had stable disease in the chronic phase. Autologous transplantation using IL-2-activated graft is feasible and the subsequent IL-2, GM-CSF, and IFN-α administration has acceptable toxicity. However, no benefits in comparison with conventional autologous transplantation for CML were identified in our study. Tissue Bank, University Hospital Brno, Czech Republic     

Cytokines and antitumor immunity

Currently, the notion of immunosurveillance against tumors is enjoying something of a renaissance. Even if we still refuse to accept that tumors arising in the normal host are unable to trigger an immune response because of the lack of initiation ("danger") signals, there is no doubt that the immune system can be manipulated experimentally and by implication therapeutically to exert anti-tumor effects. For this activity to be successful, the appropriate cytokine milieu has to be provided, making cytokine manipulation central to immunotherapy. On the other hand, the major hurdle currently preventing successful immunotherapy is the ability of tumors to evolve resistant variants under the pressure of immune selection. Here, too, the cytokine milieu plays an essential role. The purpose of this brief review is to consider the current status of the application of cytokines in facilitating antitumor immunity, as well their role in inhibiting responses to tumors. Clearly, encouraging the former but preventing the latter will be the key to the effective clinical application of cancer immunotherapy.     

Correction of cardiorespiratory disorders in laparoscopic cholecystectomy

Carboxyperitoneum and traditional forced ventilation of the lungs have a negative impact on external respiration function during laparoscopic operations, leading to impairment of the ventilation device, pressure rise in airways, and decrease in oxygen diffusion and carbon dioxide release. This leads to accumulation of carbon dioxide in the blood and tissue with a trend to development of acidosis of mixed origin. Cardiovascular changes during laparoscopic cholecystectomy manifest by hypertension and tachicardia in the presence of increased central venous pressure and total peripheral vascular resistance, decreased stroke and cardiac indexes, decreased right-ventricular diastolic function, increased pressure in the pulmonary artery, and deceleration of venous bloodflow in the inferior and superior venae cavae. The most rational variant of forced ventilation of the lungs in laparoscopic cholecystectomy is high-frequency injection ventilation, which appreciably attenuates the negative effect of carboxyperitoneum on central hemodynamics, gas exchange, and external respiration function. The optimal variant of total anesthesia in laparoscopic cholecystectmy is endotracheal combined narcosis with diprivane and fentanide. The key factor in the choice of forced ventilation protocols is the maintenance of adequate gas exchange in the lungs in the presence of the lowest possible mean pressure in the airways.     

Phage probes for malignant glial cells

Early diagnosis and effective treatment of malignant gliomas, which are heterogeneous brain tumors with variable expression of cell surface markers, are inhibited by the lack of means to characterize and target tumor-selective molecules. To create molecular profiles for RG2 rat glioma cells, we used phage display technology, an approach capable of producing valuable ligands to unknown cell surface targets. The ligands were selected from libraries of peptides displayed as fusion molecules on phage particles. Modifications of the selection conditions resulted in identification of three distinctive families of peptide ligands for malignant glioma cells. The first family with V (D)/(G) L P (E)/(T) H(3) binding motif appeared to target a marker that is common for glioma cells, normal brain cells, and cells of non-brain origin. The second group of peptide-presented phage displayed D (T)/S/(L) T K consensus sequence and contained peptides with pronounced glioma-selective properties. Phage clones expressing peptides with E (L)/V/(S) R G D S motif were found in cell lysates and represented the third family of glioma-specific ligands. All peptides within this family contain the RGD amino acid sequence, which is known to bind to a number of integrins. Phage clones that belong to this family were internalized by RG2 glioma cells about 63-fold more efficiently than by astrocytes. The approach described could be applicable for accurate detection of glioma expression patterns in individual tumors. Such patterns could be beneficial in the design of effective combinations of drugs for anti-glioma treatments.     

Efficient adaptational demethylation of chemoreceptors requires the same enzyme-docking site as efficient methylation

The mechanistic basis of sensory adaptation and gradient sensing in bacterial chemotaxis is reversible covalent modification of transmembrane chemoreceptors, methylation, and demethylation at specific glutamyl residues in their cytoplasmic domains. These reactions are catalyzed by a dedicated methyltransferase CheR and a dedicated methylesterase CheB. The esterase is also a deamidase that creates certain methyl-accepting glutamyls by hydrolysis of glutamine side chains. We investigated the action of CheB and its activated form, phospho-CheB, on a truncated form of the aspartate receptor of Escherichia coli that was missing the last 5 aa of the intact receptor. The deleted pentapeptide is conserved in several chemoreceptors in enteric and related bacteria. The truncated receptor was much less efficiently demethylated and deamidated than intact receptor, but essentially was unperturbed for kinase activation or transmembrane signaling. CheB bound specifically to an affinity column carrying the isolated pentapeptide, implying that in the intact receptor the pentapeptide serves as a docking site for the methylesterase/deamidase and that the truncated receptor was inefficiently modified because the enzyme could not dock. It is striking that the same pentapeptide serves as an activity-enhancing docking site for the methyltransferase CheR, the other enzyme involved in adaptational covalent modification of chemoreceptors. A shared docking site raises the tantalizing possibility that relative rates of methylation and demethylation could be influenced by competition between the two enzymes at that site.     

Cytopenic syndromes in chronic hepatitis

The course of chronic hepatitis complicated by cytopenia has been analyzed for 31 patients. Clinical manifestations, early and differential diagnosis, treatment policy have been specified. It is advisable that such patients be observed both by hematologists and hepatologists.     

Diffusion-transport properties of a polycomplex matrix system based on eudragit<Superscript>®</Superscript> EPO and Carbomer 940

New interpolyelectrolyte complexes (IPEC) between Eudragit^? EPO (EPO) and Carbomer 940 (C940) were synthesized for assessment as controlled-release delivery carriers for oral systems. Depending on the structural properties, the resulting IPEC were distinct from the individual (co)polymers and their physical mixtures in terms of their swelling profiles in media simulating the gastrointestinal tract. Changes in structure and composition occurring within the polycomplex matrix on swelling were studied by IR spectroscopy, MT-DSC (modulated temperature differential scanning calorimetry), and elemental analysis. The mechanism underlying the transport of the model drug ibuprofen from the polycomplex matrix was identified.     

No effect of cancer-associated SNP rs6983267 in the 8q24 region on co-expression of MYC and TCF7L2 in normal colon tissue

A single nucleotide polymorphism (SNP) rs6983267, located within the 8q24 region, is strongly associated with risk of colorectal and prostate cancer. It has been suggested that the mechanism of this association is related to differential interaction of TCF7L2 protein (previously known as TCF-4) with alleles of rs6983267, influencing the expression of a well-known oncogene, MYC, located 335 Kb telomeric. Here, we tested the correlation between mRNA expression of MYC and several alternatively spliced forms of TCF7L2 in 117 non-cancer colon samples. We observed a strong correlation (r = 0.60, p < 10^-6) between expression of MYC and a unique splicing form of TCF7L2. The level of MYC expression in these samples was associated with expression of some TCF7L2 splicing forms but not with genotypes of rs6983267, or interaction of rs6983267 with TCF7L2 expression. These findings suggest that some splicing forms of TCF7L2 may be functionally important for regulation of MYC expression in colon tissue but this regulation is not directly dependent on rs6983267.     

No effect of cancer-associated SNP rs6983267 in the 8q24 region on co-expression of MYC and TCF7L2 in normal colon tissue

Cancer precursor/progenitor cells may initiate and sustain the growth of tumors, but evidence for their existence in human disease is indirect, relying on their in vitro properties and animal models. More directly, specific elimination of these rare cells from cancer patients should produce a delayed but progressive disappearance of differentiated malignant progeny. Here, we describe selective eradication of a putative precursor population in a patient with B-cell chronic lymphocytic leukemia, followed 6 months later by a progressive loss of mature tumor cells without further treatment. This outcome supports the presence of a rare population of precursor/progenitor cells in human malignancies, and suggests benefit from their removal.