Erythropoietic protein supportive treatment in small cell lung cancer

Anemia is common among patients with malignant tumors, due to the disease and chemotherapy. Anemia decreases patient's quality of life, and worsens the dose intensity of chemotherapy. The aim of this retrospective data-analysis was to determine the rate of transfusions and the maintenance of chemotherapeutic dose intensity in 9 small cell lung cancer patients receiving beta-erythropoietin, due to anemia observed after the first cycle of chemotherapy. The mean pre-treatment hemoglobin concentration of the patients was 116.67+/-8.17 g/L (mean+/-SD). The mean pre-erythropoietin hemoglobin concentration at baseline was 103.11+/-7.52 g/L. Six cycles of platinum compounds and etoposide were used. The post-treatment hemoglobin concentration of patients was 110.11+/-5.37 g/L (p = 0,028 vs. baseline). During these 54 chemotherapeutic cycles, only 2 patients needed transfusion, each of them once. According to our experience, the use of beta-erythropoietin in 9 anemic small cell lung cancer patients resulted in a low rate of transfusions and maintenance of cytotoxic treatment dose intensity. The adequate use of beta-erythropoietin is of great help to the physician in the management of small cell lung cancer patients.     

Robustness of central carbohydrate metabolism in developing maize kernels

The central carbohydrate metabolism provides the precursors for the syntheses of various storage products in seeds. While the underlying biochemical map is well established, little is known about the organization and flexibility of carbohydrate metabolic fluxes in the face of changing biosynthetic demands or other perturbations. This question was addressed in developing kernels of maize (Zea mays L.), a model system for the study of starch and sugar metabolism. ¹³C-labeling experiments were carried out with inbred lines, heterotic hybrids, and starch-deficient mutants that were selected to cover a wide range of performances and kernel phenotypes. In total, 46 labeling experiments were carried out using either [U-¹³C₆]glucose or [U-¹³C₁₂]sucrose and up to three stages of kernel development. Carbohydrate flux distributions were estimated based on glucose isotopologue abundances, which were determined in hydrolysates of starch by using quantitative ¹³C-NMR and GC-MS. Similar labeling patterns in all samples indicated robustness of carbohydrate fluxes in maize endosperm, and fluxes were rather stable in response to glucose or sucrose feeding and during development. A lack of ADP-glucose pyrophosphorylase in the bt2 and sh2 mutants triggered significantly increased hexose cycling. In contrast, other mutations with similar kernel phenotypes had no effect. Thus, the distribution of carbohydrate fluxes is stable and not determined by sink strength in maize kernels.     

Muscular ETB receptors develop postnatally and are differentially distributed in specific segments of the rat vasculature.

The endothelin/endothelin-receptor system is a key player in the regulation of vascular tone in mammals. We raised and characterized an antiserum against rat ETB receptor and investigated the distribution of ETB receptors in different vascular beds during postnatal development (day 0 through day 28) and in the adult rat. We report the tissue-specific and age-dependent presence of vasoconstrictor ETB receptors. At the time of birth, vascular smooth muscle cells from all tissues examined did not exhibit ETB receptor immunoreactivity. The occurrence of ETB receptor immunoreactivity in the postnatal development was time dependent and started in small coronary and meningeal arteries at day 5, followed by small mesenteric arteries as well as brachial artery and vein at day 14. At day 21, ETB receptors were present in the media of muscular segments of pulmonary artery, large coronary arteries, and intracerebral arterioles. At day 28, ETB receptor immunoreactivity was evident in interlobular renal arteries, vas afferens, and efferens. Large renal arteries, mesenteric artery, and elastic segments of pulmonary arteries, as well as coronary and mesenteric veins, did not exhibit ETB receptor immunoreactivity. These data demonstrate the age-dependent and tissue-specific presence of ETB receptors, mainly on arterial smooth muscle cells in the vascular system of the rat.     

Incidence, antibiotic resistance and clonal relations of MRSA strains isolated from a Romanian university hospital

Our aim was to estimate the frequency and characteristics ofmethicillin-resistant Staphylococcus aureus (MRSA) strains occurring in a Romanian teaching hospital. We retrospectively studied isolates from infected or colonized patients treated at the intensive care and surgical units during January 2004-December 2005. The antibiotic susceptibility of MRSA strains and the presence of mecA gene were determined. Consecutively occurring strains isolated through a three-month period were typed using pulsed field gel electrophoresis. A total of 423 S. aureus strains were identified, methicillin-resistance was detected in 211 (49.9%) strains. Most of them were multiresistant. One of the MRSA genotypes identified by PFGE was commonly recovered from patients treated in the intensive care unit. According to our results, MRSA strains were frequently isolated pathogens in our hospital and there is an urgent need to enhance infection control efforts.     

Structural studies on the chiral selector capacity of cyclodextrin derivatives

Chromatographic separation of enantiomers to assure or enhance chiral purity is of considerable importance and can be achieved by the use of selectors of great structural variety. Cyclodextrins are an important and frequently used class, and they are multimodal selectors since multiple chiral interactions are possible by very different mechanisms. Here, the results of a preliminary examination on the possible value of computational molecular modeling approaches for the predictability of cyclodextrin selector effects for compounds that possess both geometrical and optical isomerism are presented. Interactions between various cyclodextrins and pyrethroic acids are modeled, interpreted, and compared to experimental capillary electrophoresis data.     

A 41 kDa protein isolated from maize mesocotyl cell walls immunolocalizes to plasmodesmata

Summary Plasmodesmata, dynamic pore structures that traverse plant cell walls, function in cytoplasmic transport between contiguous cells. Cell walls containing embedded plasmodesmata were isolated from mesocotyls of etiolated maize seedlings. Proteins associated with the isolated walls were separated by SDS-PAGE and antibodies were generated against a 41 kDa protein, one of several associated with this wall fraction. Immunoblot analysis showed that the 41 kDa polypeptide was also associated with other subcellular fractions obtained following tissue homogenization and differential centrifugation. The wall associated 41 kDa protein is apparently a peripheral membrane protein since it could be extracted by high salt and high pH. Silver-enhanced immunogold light microscopy showed that the 41 kDa protein was associated with the cell walls of cells both in the stele and cortex. The immunolabeling pattern was transwall and punctate. Electron microscopic immuno-gold labeling localized the polypeptide to plasmodesmata and to electron dense cytoplasmic structures that are apparently Golgi membranes. The significance of the presence of this protein in the Golgi is discussed.Abbreviations ER endoplasmic reticulum