CDKIs p18INK4c and p57Kip2 are involved in quiescence of CML leukemic stem cells after treatment with TKI

Chronic Myeloid Leukemia (CML) is sustained by a small population of cells with stem cell characteristics known as Leukemic Stem Cells that are positive to BCR-ABL fusion protein, involved with several abnormalities in cell proliferation, expansion, apoptosis and cell cycle regulation. Current treatment options for CML involve the use of Tirosine Kinase Inhibitor (Imatinib, Nilotinib and Dasatinib), that efficiently reduce proliferation proliferative cells but do not kill non proliferating CML primitive cells that remain and contributes to the persistence of the disease.

In order to understand the role of Cyclin Dependent Kinase Inhibitors in CML LSC permanence after TKI treatment, in this study we analyzed cell cycle status, the levels of several CDKIs and the subcellular localization of such molecules in different CML cell lines, as well as primary CD34⁺CD38^?lin^? LSC and HSC.

Our results demonstrate that cellular location of p18^INK4c and p57^Kip2 seems to be implicated in the antiproliferative activity of Imatinib and Dasatinib in CML cells and also suggest that the permanence of quiescent stem cells after TKI treatment could be associated with a decrease in p18^INK4c and p57^Kip2 nuclear location. The differences in p18^INK4cand p57^Kip2activities in CML and normal stem cells suggest a different cell cycle regulation and provide a platform that could be considered in the development of new therapeutic options to eliminate LSC.     

Voxx: a PC-based, near real-time volume rendering system for biological microscopy

Confocal and two-photon fluorescence microscopyhave advanced the exploration of complex, three-dimensional biologicalstructures at submicron resolution. We have developed a voxel-basedthree-dimensional (3-D) imaging program (Voxx) capable of nearreal-time rendering that runs on inexpensive personal computers. Thislow-cost interactive 3-D imaging system provides a powerful tool foranalyzing complex structures in cells and tissues and encourages a morethorough exploration of complex biological image data.

     

Oxidation of substituted benzyl alcohols to carboxylic acids by Nocardia corallina B-276

Whole cells of Nocardia corallina B-276, oxidized 21 substituted benzyl alcohols, at 1 mM scale, to carboxylic acids at 28-30°C, giving yields of products from 5 to 77%.     

Glass transition temperatures of cassava starch-whey protein concentrate systems at low and intermediate water content

Glass transition temperatures of cassava starch (CS)-whey protein concentrate (WPC) blends were determined by means of differential scanning calorimetry (DSC) in a water content range of 8-20% (dry basis, d.b.). Water equilibration in the samples was carried out by storing them at room temperature (25 °C) during four weeks. Physical aging and phase segregation were observed in some samples after this storage period depending on the water content. Both, first DSC heating scans and tan δ curves of CS-WPC blends with intermediate water content (10-18%), showed two endothermic thermal events. The first one appeared at around 60 °C and was independent of water content. The second one was detected at higher temperatures and moved towards the low-temperature peak as the water content increased. The results can be explained by a phase segregation process that can take place when the samples are conditioned below their glass transition temperatures. The Gordon-Taylor equation described well the plasticizing effect of water on the blends. WPC was also found to decrease the glass transition temperature, at constant water content, an effect attributed to additional water produced during browning reactions in the blends.     

Development and differentiation of the reproductive system of Tropidurus catalanensis (Squamata: Tropiduridae)

Development and differentiation of the reproductive system in lizards begin in the embryonic period, although the stage and time of their occurrence vary according to populations and species. In this study, the events of the development and differentiation of the reproductive system of males and females of Tropidurus catalanensis were characterized during the embryonic, neonatal, and juvenile periods. Embryos at Stages 27, 34, 37, 40, and 41, neonates and juveniles, from Corrientes, Argentina, were analyzed. At Stage 27, the genital ridge was not observed but primordial germ cells were recorded in the yolk sac as well as the mesenteric mesenchyme, indicating the beginning of germ cell migration. Gonadal differentiation commenced at Stage 34. In males from Stage 37, the testes possessed seminiferous cords with Sertoli cells and spermatogonia, while in hatchlings seminiferous tubules and interstitial tissue with mature Leydig cells were present. Spermatogenesis was observed in a specimen of 51.9 mm snout-vent length, corresponding to the minimum reproductive size. In females, from Stage 37 until hatching, the ovaries had a cavernous medulla and a cortex with somatic cells and abundant oogonia. The onset of meiosis and folliculogenesis occurred in the juvenile period.     

The indirect hemagglutination reaction in the diagnosis of trichinosis

An indirect hemagglutination test (IHAT) for trichinosis using a Melcher's antigen was evaluated and compared with a precipitin test (PT) and a bentonite flocculation test (BFT). One hundred and forty eight serum samples from patients from the whole country confirmed or suspected to have trichinosis by clinical or epidemiological evidences were studied: 117 (79.1%) samples resulted positive by IHAT, 138 (93.2%) by PT and 65 (43.9%) by BFT. Sixty three serum samples from patients with strong clinical suspect of trichinosis presented the PT and the BFT positive and were compared with the IHAT for sensitivity study. IHAT was positive in 60 (95.2%) serum samples. In order to determine the specificity of IHAT 25 serum samples from healthy volunteers and 124 serum samples from individuals with other parasitoses, such as cysticercosis (48), hydatidosis (45) and fascioliasis (31) were studied. The specificity, using a titre > or = 1:16 as a possible diagnostic value was 96%. The use of IHAT with RP and BFT in the diagnosis of human trichinosis is discussed.     

Fertility changes in surface waters during the Aalenian (mid-Jurassic) of the Western Tethys as revealed by calcareous nannofossils and carbon-cycle perturbations

In Aalenian times, the South Iberian Palaeomargin was part of the westernmost Tethys Ocean. The Median Subbetic palaeogeographic domain of the Betic Cordillera was a relatively deep trough in the South Iberian Palaeomargin during the Early Jurassic–Late Cretaceous interval, where mainly pelagic and hemipelagic limestones and marls were deposited. A semiquantitative study of nannofossil assemblages was performed in sediments from the upper Toarcian–lowest Bajocian from two Median Subbetic sections (Agua Larga and Cerro de Mahoma). Nannofossil assemblages are composed mainly of cosmopolitan and Tethyan taxa. The NJ8a, NJ8b and NJ9 Zones as well as other useful biohorizons (FOs of Triscutum tiziense and Carinolithus magharensis and LO of Similiscutum finchii) were identified and directly correlated to ammonite zones. The analysis of the relative abundances of some common to abundant taxa including Biscutum, Carinolithus superbus, Crepidolithus crassus, Lotharingius, Schizosphaerella and Watznaueria display noticeable fluctuations that can be correlated between the two sections. The comparison of these fluctuations with the δ¹³C_carb curves and the interpretation of the palaeoecologic significance of some of these taxa provided an outline of the palaeoceanographic trophic regime throughout the interval studied. During the latest Toarcian–Early Aalenian, the high proportions of oligotrophic Schizosphaerella, moderately high proportions of C. crassus and low proportions of eutrophic Biscutum, correlate with low to moderate values in the δ¹³C_carb curves. Radiolarians display low abundance throughout this interval. This is interpreted as an interval where mesotrophic to oligotrophic and stable conditions occurred in surface waters. The Middle Aalenian, characterized by high proportions of Schizosphaerella and C. crassus and low proportions of Biscutum, correlates with low values in the δ¹³C_carb curves, and was interpreted to correspond to an episode when stable oligotrophic conditions occurred in surface waters. Radiolarians moderately increased throughout this interval. Finally, the Late Aalenian–earliest Bajocian interval, with lower proportions of Schizosphaerella and C. crassus, and higher proportions of Biscutum, also correlates with a significant positive excursion in the δ¹³C_carb curve, suggesting a shift from oligo- to eutrophic conditions in surface waters. This change in productivity is also revealed by a conspicuous increase in radiolarian abundance, at the same time as a quasi-complete replacement of Early Jurassic radiolarian fauna took place. The analysis of faunal-flora turnovers reveals a causal link between the global carbon-cycle and the pelagic response. This noticeable faunal-flora change throughout the Late Aalenian–Bajocian can be interpreted as a major biological response to the drastic modification in the western Tethys palaeogeography as consequence of the Atlantic opening, which in turn caused a new pattern in the oceanic circulation.