Spatiotemporal analysis of Ca(2+) waves in relation to the sperm entry site and animal-vegetal axis during Ca(2+) oscillations in fertilized mouse eggs

Fertilized mouse eggs exhibit repetitive rises in intracellular Ca(2+) concentration ([Ca(2+)](i)) necessary for egg activation. Precise spatiotemporal dynamics of each [Ca(2+)](i) rise were investigated by high-speed Ca(2+) imaging during early development of monospermic eggs. Every [Ca(2+)](i) rise involved a Ca(2+) wave. In the first Ca(2+) transient, [Ca(2+)](i) increased in two steps separated by a "shoulder" point, suggesting two distinct Ca(2+) release mechanisms. The first step was a Ca(2+) wave that propagated from the sperm-fusion site to its antipode in 4-5 s (velocity, approximately 20 microm/s in most eggs). The second step from the shoulder to the peak was a nearly uniform [Ca(2+)](i) rise of 12-15 s. A slight cytoplasmic movement followed the Ca(2+) wave in the same direction and recovered in 25-35 s. These characteristics changed as follows, as Ca(2+) oscillations progressed during the second meiosis up to their cessation at the stage of pronuclei formation ( approximately 3 h after fertilization). (1) The duration of Ca(2+) transients became shorter. (2) The shoulder point shifted to higher levels and the first step occupied most of the rising phase. (3) The rate of [Ca(2+)](i) rise became greater and wave speeds increased up to 80-100 microm/s or more. (4) The transient cytoplasmic movement always resulted from the Ca(2+) wave, although its displacement became smaller. (5) The Ca(2+) wave initiation site was freed from the sperm-fusion or -entry site and eventually localized in the cortex of the vegetal hemisphere. Since the shift of the wave initiation site to the vegetal cortex is observed in fertilized eggs of nemertean worms and ascidians, this might be an evolutionarily conserved feature.     

Host range expansion by Rhopalomyia yomogicola (Diptera: Cecidomyiidae) from a native to an alien species of Artemisia (Asteraceae) in Japan

In 2001, subconical galls were found on the leaves of an alien Artemisia species (Asteraceae) in Ibusuki City, Kagoshima Prefecture, Japan. These galls were quite similar to those induced by Rhopalomyia yomogicola (Diptera: Cecidomyiidae) on Artemisia princeps, Artemisia montana, and Artemisia japonica in Japan. The morphological features of the pupal head and molecular sequencing data indicated that the gall midge from the alien Artemisia was identical to R. yomogicola. Usually, galling insects do not expand readily their host range to alien plants, but R. yomogicola is considered to have expanded its host range to the alien Artemisia by its multivoltine life history trait and oligophagous habit across two different botanical sections of the genus Artemisia. Adult abdominal tergites and sternites and immature stages of R. yomogicola are described for the first time and detailed biological information is presented.     

Contrasting Effects of the Cytotoxic Anticancer Drug Gemcitabine and the EGFR Tyrosine Kinase Inhibitor Gefitinib on NK Cell-Mediated Cytotoxicity via Regulation of NKG2D Ligand in Non-Small-Cell Lung Cancer Cells

IntroductionSeveral cytotoxic anticancer drugs inhibit DNA replication and/or mitosis, while EGFR tyrosine kinase inhibitors inactivate EGFR signalling in cancer cell. Both types of anticancer drugs improve the overall survival of the patients with non-small-cell lung cancer (NSCLC), although tumors often become refractory to this treatment. Despite several mechanisms by which the tumors become resistant having been described the effect of these compounds on anti-tumor immunity remains largely unknown.MethodsThis study examines the effect of the cytotoxic drug Gemcitabine and the EGFR tyrosine kinase inhibitor Gefitinib on the expression of NK group 2 member D (NKG2D) ligands as well as the sensitivity of NSCLC cells to the NK-mediated lysis.ResultsWe demonstrate that Gemcitabine treatment leads to an enhanced expression, while Gefitinib downregulated the expression of molecules that act as key ligands for the activating receptor NKG2D and promote NK cell-mediated recognition and cytolysis. Gemcitabine activated ATM and ATM- and Rad-3-related protein kinase (ATR) pathways. The Gemcitabine-induced phosphorylation of ATM as well as the upregulation of the NKG2D ligand expression could be blocked by an ATM-ATR inhibitor. In contrast, Gefitinib attenuated NKG2D ligand expression. Silencing EGFR using siRNA or addition of the PI3K inhibitor resulted in downregulation of NKG2D ligands. The observations suggest that the EGFR/PI3K pathway also regulates the expression of NKG2D ligands. Additionally, we showed that both ATM-ATR and EGFR regulate MICA/B via miR20a.ConclusionIn keeping with the effect on NKG2D expression, Gemcitabine enhanced NK cell-mediated cytotoxicity while Gefitinib attenuated NK cell killing in NSCLC cells.     

Medical Decision-Making Incapacity among Newly Diagnosed Older Patients with Hematological Malignancy Receiving First Line Chemotherapy: A Cross-Sectional Study of Patients and Physicians

Background

Decision-making capacity to provide informed consent regarding treatment is essential among cancer patients. The purpose of this study was to identify the frequency of decision-making incapacity among newly diagnosed older patients with hematological malignancy receiving first-line chemotherapy, to examine factors associated with incapacity and assess physicians’ perceptions of patients’ decision-making incapacity.

Methods

Consecutive patients aged 65 years or over with a primary diagnosis of malignant lymphoma or multiple myeloma were recruited. Decision-making capacity was assessed using the Structured Interview for Competency and Incompetency Assessment Testing and Ranking Inventory-Revised (SICIATRI-R). Cognitive impairment, depressive condition and other possible associated factors were also evaluated.

Results

Among 139 eligible patients registered for this study, 114 completed the survey. Of these, 28 (25%, 95% confidence interval [CI]: 17%-32%) were judged as having some extent of decision-making incompetency according to SICIATRI-R. Higher levels of cognitive impairment and increasing age were significantly associated with decision-making incapacity. Physicians experienced difficulty performing competency assessment (Cohen’s kappa -0.54).

Conclusions

Decision-making incapacity was found to be a common and under-recognized problem in older patients with cancer. Age and assessment of cognitive impairment may provide the opportunity to find patients that are at a high risk of showing decision-making incapacity.     

Glucose Homeostatic Law: Insulin Clearance Predicts the Progression of Glucose Intolerance in Humans

Homeostatic control of blood glucose is regulated by a complex feedback loop between glucose and insulin, of which failure leads to diabetes mellitus. However, physiological and pathological nature of the feedback loop is not fully understood. We made a mathematical model of the feedback loop between glucose and insulin using time course of blood glucose and insulin during consecutive hyperglycemic and hyperinsulinemic-euglycemic clamps in 113 subjects with variety of glucose tolerance including normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM). We analyzed the correlation of the parameters in the model with the progression of glucose intolerance and the conserved relationship between parameters. The model parameters of insulin sensitivity and insulin secretion significantly declined from NGT to IGT, and from IGT to T2DM, respectively, consistent with previous clinical observations. Importantly, insulin clearance, an insulin degradation rate, significantly declined from NGT, IGT to T2DM along the progression of glucose intolerance in the mathematical model. Insulin clearance was positively correlated with a product of insulin sensitivity and secretion assessed by the clamp analysis or determined with the mathematical model. Insulin clearance was correlated negatively with postprandial glucose at 2h after oral glucose tolerance test. We also inferred a square-law between the rate constant of insulin clearance and a product of rate constants of insulin sensitivity and secretion in the model, which is also conserved among NGT, IGT and T2DM subjects. Insulin clearance shows a conserved relationship with the capacity of glucose disposal among the NGT, IGT and T2DM subjects. The decrease of insulin clearance predicts the progression of glucose intolerance.     

Extreme rapid warming yields high functional survivals of vitrified 8-cell mouse embryos even when suspended in a half-strength vitrification solution and cooled at moderate rates to −196 °C

To cryopreserve cells, it is essential to avoid intracellular ice formation during cooling and warming. One way to do so is to subject them to procedures that convert cell water into a non-crystalline glass. Current belief is that to achieve this vitrification, cells must be suspended in very high concentrations of glass-inducing solutes (i.e., ?6 molal) and cooled at very high rates (i.e., ?1000 °C/min). We report here that both these beliefs are incorrect with respect to the vitrification of 8-cell mouse embryos. In this study, precompaction 8-cell embryos were vitrified in several dilutions of EAFS10/10 using various cooling rates and warming rates. Survival was based on morphology, osmotic functionality, and on the ability to develop to expanded blastocysts. With a warming rate of 117,500 °C/min, the percentages of embryos vitrified in 1×, 0.75×, and 0.5× EAFS that developed to blastocysts were 93%, 92%, and 83%, respectively. And the percentages of morphological survivors that developed to expanded blastocysts were 100%, 92%, and 97%, respectively. Even when the solute concentration of the EAFS was reduced to 33% of normal, we obtained 40% functional survival of these 8-cell embryos.     

Effects of TGF-β1 on the proliferation and differentiation of human periodontal ligament cells and a human periodontal ligament stem/progenitor cell line

Periodontal ligament (PDL) is a specialized connective tissue that influences the lifespan of the tooth. Transforming growth factor-β1 (TGF-β1) is a multifunctional cytokine, but little is known about the effects of TGF-β1 on PDL cells. Our aim has been to demonstrate the expression of TGF-β1 in rat PDL tissues and to evaluate its effects on the proliferation and gene expression in human PDL cells (HPLCs) and a human PDL stem/progenitor cell line, line 1-11, that we have recently developed. The expression of TGF-β1 in the entire PDL tissue was confirmed immunohistochemically, and both HPLCs and cell line 1-11 expressed mRNA from the TGF-β1, TGF-β type I receptor, and TGF-β type II receptor genes. Although exogenous TGF-β1 stimulated the proliferation of HPLCs, it did not upregulate the expression of alpha-smooth muscle actin (α-SMA), type I collagen (Col I), or fibrillin-1 (FBN1) mRNA or of α-SMA protein in HPLCs, whereas expression for these genes was attenuated by an anti-TGF-β1 neutralizing antibody. In contrast, exogenous TGF-β1 reduced the proliferation of cell line 1-11, although it upregulated the expression of α-SMA, Col I, and FBN1 mRNA and of α-SMA protein in this cell line. In addition, interleukin-1 beta stimulation significantly reduced the expression of TGF-β1 mRNA and protein in HPLCs. Thus, TGF-β1 seems to play an important role in inducing fibroblastic differentiation of PDL stem/progenitor cells and in maintaining the PDL apparatus under physiological conditions.     

Comparison of brain–computer interface decoding algorithms in open-loop and closed-loop control

Neuroprosthetic devices such as a computer cursor can be controlled by the activity of cortical neurons when an appropriate algorithm is used to decode motor intention. Algorithms which have been proposed for this purpose range from the simple population vector algorithm (PVA) and optimal linear estimator (OLE) to various versions of Bayesian decoders. Although Bayesian decoders typically provide the most accurate off-line reconstructions, it is not known which model assumptions in these algorithms are critical for improving decoding performance. Furthermore, it is not necessarily true that improvements (or deficits) in off-line reconstruction will translate into improvements (or deficits) in on-line control, as the subject might compensate for the specifics of the decoder in use at the time. Here we show that by comparing the performance of nine decoders, assumptions about uniformly distributed preferred directions and the way the cursor trajectories are smoothed have the most impact on decoder performance in off-line reconstruction, while assumptions about tuning curve linearity and spike count variance play relatively minor roles. In on-line control, subjects compensate for directional biases caused by non-uniformly distributed preferred directions, leaving cursor smoothing differences as the largest single algorithmic difference driving decoder performance.