Influence of hyaluronan accumulation during cumulus expansion on in vitro porcine oocyte maturation

During oocyte maturation, the cumulus-oocyte complexes (COCs) expand dramatically. This phenomenon, which is known as cumulus expansion, is the result of the synthesis and accumulation of hyaluronan in the extracellular space between cumulus cells. The purpose of this study was to investigate the effect of 6-diazo-5-oxo-l-norleucine (DON), an inhibitor of hyaluronan synthesis, on cumulus expansion during in vitro porcine oocyte maturation and hyaluronan accumulation within COCs. Further, this study aimed to examine the influence of hyaluronan accumulation within COCs on the rate of oocyte maturation. Cumulus expansion was observed during in vitro maturation. However, the addition of DON to the maturation medium significantly inhibited cumulus expansion. The total inhibition of hyaluronan accumulation within COCs was observed with the use of confocal microscopy. Moreover, a positive correlation between the area of cumulus expansion and the rate of oocyte maturation was observed. These results demonstrate that the hyaluronan accumulation within the COCs during oocyte maturation affects oocyte maturation. On the basis of these results, we propose that hyaluronan accumulation within the COCs during cumulus expansion is a necessary step in the porcine oocyte maturation process.     

Establishment of mouse embryonic stem cell-derived erythroid progenitor cell lines able to produce functional red blood cells

Background

The supply of transfusable red blood cells (RBCs) is not sufficient in many countries. If erythroid cell lines able to produce transfusable RBCs in vitro were established, they would be valuable resources. However, such cell lines have not been established. To evaluate the feasibility of establishing useful erythroid cell lines, we attempted to establish such cell lines from mouse embryonic stem (ES) cells.

Methodology/Principal Findings

We developed a robust method to obtain differentiated cell lines following the induction of hematopoietic differentiation of mouse ES cells and established five independent hematopoietic cell lines using the method. Three of these lines exhibited characteristics of erythroid cells. Although their precise characteristics varied, each of these lines could differentiate in vitro into more mature erythroid cells, including enucleated RBCs. Following transplantation of these erythroid cells into mice suffering from acute anemia, the cells proliferated transiently, subsequently differentiated into functional RBCs, and significantly ameliorated the acute anemia. In addition, we did not observe formation of any tumors following transplantation of these cells.

Conclusion/Significance

To the best of our knowledge, this is the first report to show the feasibility of establishing erythroid cell lines able to produce mature RBCs. Considering the number of human ES cell lines that have been established so far, the intensive testing of a number of these lines for erythroid potential may allow the establishment of human erythroid cell lines similar to the mouse erythroid cell lines described here. In addition, our results strongly suggest the possibility of establishing useful cell lines committed to specific lineages other than hematopoietic progenitors from human ES cells.     

What is the quality of quality of medical care measures? Rashomon-like relativism and real-world applications

Much attention has been directed toward the measurement of health outcomes and the quality of medical care. Some policymakers tout outcomes measurement as a promising tool for improving health care, while others question whether current quality of care assessment is valid and of practical importance. Although significant advances have been made in the ability to measure quality of care with validity, several major methodological challenges remain. We analyze the quality of quality of medical care measures, using a conceptual framework that outlines the purpose of the measures; paradigms of the quality of care, including Donabedian's structure-process-outcome model and continuous quality improvement; and other key elements, such as scope, time, unit of analysis, and perspectives. Patient preferences and organizational contexts have been underemphasized, and should be incorporated into the framework for conceptualizing quality of care. Quality of care has relativistic and dynamic aspects. Different perspectives lead to different views of what high quality care is, and quality of care is a changing concept since medical science and treatment are constantly evolving. The most appropriate quality measures depend upon whose perspective one takes and the purpose of the measures; if the measures are chosen wisely, the current state of quality of medical care measurement is adequate for both accountability and quality improvement.     

Fire history influences on the spatial heterogeneity of soil nitrogen transformations in three adjacent stands in a dry tropical forest in Thailand

Spatial patterns of soil nitrogen (N) transformations were examined using geostatistical analysis in three adjacent stands with different fire history (0, 10 and 35 years since the latest fire, respectively) in a dry tropical forest in Thailand. A larger pool of total inorganic N and a faster rate of N mineralization were recorded in the stand with longer fire prevention. At the spatial scale analyzed, the proportion of spatially dependent variance to the total variance of N mineralization and nitrification increased from 0.39 to 0.73, and from 0.40 to 0.77, respectively, with the time since the latest fire. The spatial autocorrelation ranges of N mineralization and nitrification decreased from 9.0 to 3.28 m, and 9.0 to 2.77 m, respectively, with the time since the latest fire. These results suggested that fire history affected not only the level of available soil N, but also the spatial heterogeneity of soil N transformations, presumably due to the difference in plant influences on soil.     

Mental health problems and influencing factors in Japanese women 4?months after delivery

Background

Postpartum mental health problems are a major public health issue; however, studies on the mental health status of mothers and its influencing factors between 8 weeks and 1 year postpartum are scarce. Furthermore, it would be necessary to examine the factors influencing mothers’ mental health in order to evaluate their physiological adaptations to the nursing environment.

Methods

We examined the mental health status of postpartum women and the factors influencing poor mental health at 4 months after delivery. A cross-sectional study of 584 postpartum women was conducted. Information on mental health status, delivery, and other factors was collected using a self-administered questionnaire. Women were asked about their age, height, weight, gestational or marital status, whether they were eating regular meals, appetite, frequency of going out, financial difficulty, stressful life events, and history of depression. The Japanese version of the 12-item General Health Questionnaire (GHQ-12) was used to identify potential poor mental health status. Participants with GHQ-12 scores of ≥4 were classified as the high GHQ-12 score group (poor mental health status) and participants with GHQ-12 scores of ≤3 were classified as the low GHQ-12 score group (good mental health status).

Results

Forty-five women (7.7%) were classified as having high GHQ-12 scores. Multiple logistic regression analysis revealed that older age, not eating meals regularly, and history of depression were significantly associated with poor mental health. Financial difficulty had a borderline association with poor mental health in this model.

Conclusions

These risk factors might help practitioners identify women at high risk of poor mental health after delivery.     

Commensal Bacteria Regulate Thymic Aire Expression

Commensal bacteria in gastrointestinal tracts are reported to function as an environmental factor to regulate intestinal inflammation and immune responses. However, it remains largely unknown whether such bacterial function exerts any effect on other immune organs distant from the intestine. In this study, the influence of commensal bacteria in the thymus, where T cell lineages develop into mature type to form proper repertoires, was investigated using germ-free (GF) mice and Nod1-deficient mice lacking an intracellular recognition receptor for certain bacterial components, in which a commensal bacterial effect is predicted to be less. In both mice, there was no significant difference in the numbers and subset ratios of thymocytes. Interestingly, however, autoimmune regulator (Aire) expression in thymic epithelial cells (TECs), main components of the thymic microenvironment, was decreased in comparison to specific pathogen-free (SPF) mice and Nod1 wild-type (WT) mice, respectively. In vitro analysis using a fetal thymus organ culture (FTOC) system showed that Aire expression in TECs was increased in the presence of a bacterial component or a bacterial product. These results suggest that through their products, commensal bacteria have the potential to have some effect on epithelial cells of the thymus in tissues distant from the intestine where they are originally harbored.     

Comparative Analyses of Three Chlorella Species in Response to Light and Sugar Reveal Distinctive Lipid Accumulation Patterns in the Microalga C. sorokiniana

While photosynthetic microalgae, such as Chlorella, serve as feedstocks for nutritional oils and biofuels, heterotrophic cultivation can augment growth rates, support high cell densities, and increase triacylglycerol (TAG) lipid content. However, these species differ significantly in their photoautotrophic and heterotrophic characteristics. In this study, the phylogeny of thirty Chlorella strains was determined in order to inform bioprospecting efforts and detailed physiological assessment of three species. The growth kinetics and lipid biochemistry of C. protothecoides UTEX 411, C. vulgaris UTEX 265, and C. sorokiniana UTEX 1230 were quantified during photoautotrophy in Bold''s basal medium (BBM) and heterotrophy in BBM supplemented with glucose (10 g L⁻¹). Heterotrophic growth rates of UTEX 411, 265, and 1230 were found to be 1.5-, 3.7-, and 5-fold higher than their respective autotrophic rates. With a rapid nine-hour heterotrophic doubling time, Chlorella sorokiniana UTEX 1230 maximally accumulated 39% total lipids by dry weight during heterotrophy compared to 18% autotrophically. Furthermore, the discrete fatty acid composition of each strain was examined in order to elucidate lipid accumulation patterns under the two trophic conditions. In both modes of growth, UTEX 411 and 265 produced 18∶1 as the principal fatty acid while UTEX 1230 exhibited a 2.5-fold enrichment in 18∶2 relative to 18∶1. Although the total lipid content was highest in UTEX 411 during heterotrophy, UTEX 1230 demonstrated a two-fold increase in its heterotrophic TAG fraction at a rate of 28.9 mg L⁻¹ d⁻¹ to reach 22% of the biomass, corresponding to as much as 90% of its total lipids. Interestingly, UTEX 1230 growth was restricted during mixotrophy and its TAG production rate was suppressed to 18.2 mg L⁻¹ d⁻¹. This constraint on carbon flow raises intriguing questions about the impact of sugar and light on the metabolic regulation of microalgal lipid biosynthesis.     

P2Y-receptor regulates size of endothelial cells in an intracellular Ca2+ dependent manner

The effects of P2 receptor agonists on cell size and intracellular calcium levels, [Ca(2+)](i), was investigated using cultured endothelial cells isolated from the caudal artery of male Wistar rats. Cell size and [Ca(2+)](i) were measured using a phase-contrast and fluorescent confocal microscopic image analyzer and a Calcium Green fluorescence probe. P2Y receptor agonists, 2-methylthio ATP (2meS-ATP), ADP, UTP and ATP decreased the cell size and increased [Ca(2+)](i) in endothelial cells from rat caudal artery. However, alpha,beta-methylene ATP, a P2X receptor agonist, did not induce these responses. The decrease in size and the increase in [Ca(2+)](i), by 2meS-ATP were blocked by PPADS (P2-antagonist), suramin (P2-antagonist), thapsigargin (Ca(2+) pump inhibitor) and U-73122 (phospholipase C inhibitor). The present results show that activation of P2Y receptors, not P2X receptors, induces a decrease in cell size and an increase in [Ca(2+)](i), and the pharmacological properties of these two responses are the same. We concluded that the size of endothelial cells is regulated by P2Y receptors via intracelluar Ca(2+) derived from Ca(2+) stores.