Identification of significant regions of transcription factor DP-1 (TFDP-1) involved in stability/instability of the protein

We previously reported the identification of DP-1 isoforms (α and β), which are structurally C-terminus-deleted ones, and revealed the low-level expression of these isoforms. It is known that wild-type DP-1 is degraded by the ubiquitin-proteasome system, but few details are known about the domains concerned with the protein stability/instability for the proteolysis of these DP-1 isoforms. Here we identified the domains responsible for the stability/instability of DP-1. Especially, the DP-1 “Stabilon” domain was a C-terminal acidic motif and was quite important for DP-1 stability. Moreover, we propose that this DP-1 Stabilon may be useful for the stability of other nuclear proteins when fused to them.     

Calculation of effective diffusivities for biofilms and tissues.

In this study we describe a scheme for numerically calculating the effective diffusivity of cellular systems such as biofilms and tissues. This work extends previous studies in which we developed the macroscale representations of the transport equations for cellular systems based on the subcellular-scale transport and reaction processes. A finite-difference model is used to predict the effective diffusivity of a cellular system on the basis of the subcellular-scale geometry and transport parameters. The effective diffusivity is predicted for a complex three-dimensional structure that is based on laboratory observations of a biofilm, and these numerical predictions are compared with predictions from a simple analytical solution and with experimental data. Our results indicate that, under many practical circumstances, the simple analytical solution can be used to provide reasonable estimates of the effective diffusivity.     

The effect of temperature on reproduction in three species of cyclopoid copepods

Megacyclops viridis (Jurine), Macrocyclops albidus (Jurine), and Acanthocyclops vernalis (Fischer) were raised in the laboratory at six temperatures (5, 8, 10, 12, 15 and 20°) and fed a mixture of ciliates (Paramecium caudatum and Colpidium campylum). Data were taken on clutch size, embryonic development time, interclutch period, time to first clutch, sex ratio and longevity.Clutch size, time to first clutch, embryonic development time, interclutch period and longevity are inversely related to temperature. The ratio of males to females in a cohort is independent of temperature.     

Novel Monte Carlo dose calculation algorithm for robotic radiosurgery with multi leaf collimator: Dosimetric evaluation

PurposeAt introduction in 2014, dose calculation for the first MLC on a robotic SRS/SBRT platform was limited to a correction-based Finite-Size Pencil Beam (FSPB) algorithm. We report on the dosimetric accuracy of a novel Monte Carlo (MC) dose calculation algorithm for this MLC, included in the Precision™ treatment planning system.MethodsA phantom was built of one slab (5.0 cm) of lung-equivalent material (0.09…0.29 g/cc) enclosed by 3.5 cm (above) and 5 cm (below) slabs of solid water (1.045 g/cc). This was irradiated using rectangular (15.4 × 15.4 mm² to 53.8 × 53.7 mm²) and two irregular MLC-fields. Radiochromic film (EBT3) was positioned perpendicular to the slabs and parallel to the beam. Calculated dose distributions were compared to film measurements using line scans and 2D gamma analysis.ResultsMeasured and MC calculated percent depth dose curves showed a characteristic dose drop within the low-density region, which was not correctly reproduced by FSPB. Superior average gamma pass rates (2%/1 mm) were found for MC (91.2 ± 1.5%) compared to FSPB (55.4 ± 2.7%). However, MC calculations exhibited localized anomalies at mass density transitions around 0.15 g/cc, which were traced to a simplification in electron transport. Absence of these anomalies was confirmed in a modified build of the MC engine, which increased gamma pass rates to 96.6 ± 1.2%.ConclusionsThe novel MC algorithm greatly improves dosimetric accuracy in heterogeneous tissue, potentially expanding the clinical use of robotic radiosurgery with MLC. In-depth, independent validation is paramount to identify and reduce the residual uncertainties in any software solution.     

Influence of retinoids and EGF on growth of embryonic mouse palatal epithelia in culture

Summary Retinoids and growth factors seem to be important for normal mammalian reproduction and development. High levels of retinoic acid are teratogenic and induce cleft palate in the mouse. Little is known concerning the mechanisms through which retinoids induce cleft palate. Palatal epithelia from CD-1 embryonic mice on Day 12 of gestation were isolated from the mesenchyme and cultured in serum-free media, with all-trans retinoic acid or 13-cis retinoic acid, with or without epidermal growth factor (EGF). The epithelia attached and grew, and the cells differentiated over a 72-h culture period. Binding of [¹²⁵I]EGF was observed in all cultures in a pattern that correlated with thymidine (TdR) uptake by the epithelia. EGF enhanced growth and [³H]TdR incorporation of the oral cells, but nasal cells generally did not proliferate. In this culture system, both retinoids suppressed [³H]TdR incorporation in a concentration-dependent manner for epithelia cultured with or without EGF. Medial cells are important to normal palatogenesis as they play a role in fusion of opposing shelves and subsequently many of these cells undergo programmed cell death. Death of medial cells in vitro is prevented by EGF and by the retinoids, either with or without EGF. This response occurs in the absence of a mesenchymal interaction, suggesting that the medial cell response to EGF and retinoids is not mediated by or dependent on the mesenchymal tissues. The survival of medial cells may be responsible for the failure of opposing shelves to fuse.     

Tangential cell migration during layer formation of chick optic tectum

The laminated structure of the optic tectum is formed by radial and tangential cell migration during development. Studies of developing chick optic tectum have revealed two streams of tangential cell migration in the middle and superficial layers, which have distinctive origins, migratory paths, modes of migration, and destinations. We will review the process of the two types of tangential migrations, in order to elucidate their roles in the formation of the optic tectum layers.     

Intrinsic vs. extrinsic influences on life history expression: metabolism and parentally induced temperature influences on embryo development rate

Intrinsic processes are assumed to underlie life history expression and trade‐offs, but extrinsic inputs are theorised to shift trait expression and mask trade‐offs within species. Here, we explore application of this theory across species. We do this based on parentally induced embryo temperature as an extrinsic input, and mass‐specific embryo metabolism as an intrinsic process, underlying embryonic development rate. We found that embryonic metabolism followed intrinsic allometry rules among 49 songbird species from temperate and tropical sites. Extrinsic inputs via parentally induced temperatures explained the majority of variation in development rates and masked a relationship with metabolism; metabolism explained a minor proportion of the variation in development rates among species, and only after accounting for temperature effects. We discuss evidence that temperature further obscures the expected interspecific trade‐off between development rate and offspring quality. These results demonstrate the importance of considering extrinsic inputs to trait expression and trade‐offs across species.     

Embryonic Ammonoid Shell Features: Intraspecific Variation Revisited

Two samples of ammonoids belonging to the Oppeliidae, Sublunuloceras virguloidesHecticoceras (Brightii) canaliculatum, are analyzed to estimate the intraspecific variability of embryonic shell features. The study of embryonic shell characters reveals two main shapes of protoconch, flattened and round. Prosiphons may be straight or slightly curved. New parameters for area are added to the linear parameters commonly found in the literature. Prosiphon length and caecum area vary greatly whereas protoconch and ammonitella diameter vary only slightly, and the ammonitella angle is almost constant. The protoconch-to-ammonitella size ratio behaves differently in each species, suggesting different patterns of embryonic growth. We compare our results with published data and discuss their significance for species determination and ontogenetic interpretation. The main finding is that intraspecific embryonic variation is greater than was previously believed.     

Effects of etretinate on the distribution of elements in rats

We studied in the rat the effects of the drug etretinate (Tigason), given at three doses 3, 10, and 30 mg/kg body wt for 1 mo, on the concentrations of Na, K, Ca, Mg, Fe, S, P, Cu, and Zn in the plasma, brain, thymus, heart, liver, lung, kidney, testicle, muscle, and bone. The elements were simultaneously determined in tissues after nitric acid dissolution by inductively coupled plasma emission spectrometry using a JY 48 instrument. At the dose of 3 mg/kg, etretinate did not induce any statistically significant modifications of the element distribution. At the dose of 10 mg/kg, the main observed modifications were in plasma an increase of copper (+38%) and a decrease of zinc (-25%). At the highest dose of 30 mg/kg, some variations of the concentrations of elements in tissues were observed. But, on no account did retinoids induce an alteration of the mineral composition of bone, despite obvious macroscopic bone alterations.