Low-dose metformin targets the lysosomal AMPK pathway through PEN2.

Metformin, the most prescribed antidiabetic medicine, has shown other benefits such as anti-ageing and anticancer effects1-4. For clinical doses of metformin, AMP-activated protein kinase (AMPK) has a major role in its mechanism of action4,5; however, the direct molecular target of metformin remains unknown. Here we show that clinically relevant concentrations of metformin inhibit the lysosomal proton pump v-ATPase, which is a central node for AMPK activation following glucose starvation6. We synthesize a photoactive metformin probe and identify PEN2, a subunit of γ-secretase7, as a binding partner of metformin with a dissociation constant at micromolar levels. Metformin-bound PEN2 forms a complex with ATP6AP1, a subunit of the v-ATPase8, which leads to the inhibition of v-ATPase and the activation of AMPK without effects on cellular AMP levels. Knockout of PEN2 or re-introduction of a PEN2 mutant that does not bind ATP6AP1 blunts AMPK activation. In vivo, liver-specific knockout of Pen2 abolishes metformin-mediated reduction of hepatic fat content, whereas intestine-specific knockout of Pen2 impairs its glucose-lowering effects. Furthermore, knockdown of pen-2 in Caenorhabditis elegans abrogates metformin-induced extension of lifespan. Together, these findings reveal that metformin binds PEN2 and initiates a signalling route that intersects, through ATP6AP1, the lysosomal glucose-sensing pathway for AMPK activation. This ensures that metformin exerts its therapeutic benefits in patients without substantial adverse effects.

Association of filial attitude, filial behavior and death literacy: implications for development of death system in Guangdong-Hong Kong-Macao Greater Bay Area of China.

BACKGROUND: Filial piety, as a major traditional norm in Chinese culture and in Chinese families, affects the attitudes and behaviors of adult children toward their parents and impacts their end-of-life decision-making and the quality of death of their parents. Death literacy is a novel concept aimed at promoting palliative care in the context of public health. AIMS: To understand attitudes and behaviors related to filial piety and to examine the role of death literacy in filial behaviors toward dying parents among residents in the Guangdong-Hong Kong-Macao Greater Bay Area of China. METHODS: A cross-sectional online survey that employed the convenient and snowball sampling methods was adopted. Filial Piety Representations at Parents' End of Life Scale and Death Literacy Index were used. RESULTS: This study identified a significant gap between the filial piety attitudes and behaviors of Chinese adult children. Gender, caregiving experience and death literacy were predictors of filial behaviors in an end-of-life context. CONCLUSION: Providing truth disclosure support, offering guidance to young adult children and caregivers of terminally ill fathers, and strengthening factual and community knowledge of death are necessary to enhance the reciprocal comfort of both adult children and dying parents in the context of Chinese filiality.

Perspectives on dementia care self-learning platform: A focus group study of family and professional caregivers.

OBJECTIVE: To compare perspectives of family and professional caregivers regarding an online self-learning platform. METHODS: Family and professional caregivers were interviewed separately. A thematic analysis was conducted with 12 family caregivers and 13 professional caregivers of people living with dementia in Macao using six semi-structured focus group interviews. RESULTS: Family and professional caregivers had different perspectives regarding the application of online learning program Four main themes emerged from the focus groups, including similarities and differences, namely 1) Need for services; 2) Accessibility to services; 3) Barriers to online learning; 4) Adjustments to the platform. CONCLUSIONS: The psychological assurance offered by an online learning program is imperative to the well-being of family caregivers. By identifying the gap between the needs and abilities of family caregivers and those imagined by professional caregivers, it allows for the development of support programs and interventions tailored to meet the specific needs of family caregivers.

Integrating genomics and transcriptomics to identify candidate genes for high egg production in Wulong geese (Anser cygnoides orientalis).

BACKGROUND: Wulong geese (Anser cygnoides orientalis) are known for their excellent egg-laying performance. However, they show considerable population differences in egg-laying behavior. This study combined genome-wide selection signal analysis with transcriptome analysis (RNA-seq) to identify the genes related to high egg production in Wulong geese. RESULTS: A total of 132 selected genomic regions were screened using genome-wide selection signal analysis, and 130 genes related to high egg production were annotated in these regions. These selected genes were enriched in pathways related to egg production, including oocyte meiosis, the estrogen signaling pathway, the oxytocin signaling pathway, and progesterone-mediated oocyte maturation. Furthermore, a total of 890 differentially expressed genes (DEGs), including 340 up-regulated and 550 down-regulated genes, were identified by RNA-seq. Two genes - GCG and FAP - were common to the list of selected genes and DEGs. A non-synonymous single nucleotide polymorphism was identified in an exon of FAP. CONCLUSIONS: Based on genome-wide selection signal analysis and transcriptome data, GCG and FAP were identified as candidate genes associated with high egg production in Wulong geese. These findings could promote the breeding of Wulong geese with high egg production abilities and provide a theoretical basis for exploring the mechanisms of reproductive regulation in poultry.

The expression level of Neuronal Calcium Sensor 1 can predict the prognosis of cytogenetically normal AML.

Acute myeloid leukemia (AML) is malignant clonal expansion of myeloid blasts with high heterogeneity and numerous molecular biomarkers have been found to judge the prognosis in some specific classifications of AML. Furthermore, as for patients with cytogenetically normal acute myeloid leukemia (CN-AML), we need to find more new biomarkers to predict the patients' outcomes. Recently, the expression level of Neuronal Calcium Sensor 1 (NCS1) has been associated with the prognosis of breast cancer and hepatocellular carcinoma, but nothing related has been reported about hematological malignancies. Therefore, we make this study to explore the relationship between the NCS1 expression level and CN-AML. We analyzed the relation between survival and NCS1 RNA expression through 75 CN-AML patients from Cancer Genome Atlas (TCGA) database and 433 CN-AML patients (3 independent datasets) from Gene Expression Omnibus (GEO) database. Additionally, we compared the NCS1 RNA expression between 138 leukemia stem cells positive (LSCs+) samples and 89 leukemia stem cells negative (LSCs-) samples from 78 AML patients from GSE76004 dataset. In our study, CN-AML patients with high expression level of NCS1 have longer EFS or OS. In addition, the NCS1 expression level in leukemia stem cells was low (p = 0.00039). According to these findings, we concluded that the high expression of NCS1 can predict favorable prognosis in CN-AML patients. Furthermore, our work put forward that NCS1 expresses lower in LSCs+, which might be an important mechanism to explain the aggressiveness of AML.

RNA-seq analysis identifies differentially expressed gene in different types of donkey skeletal muscles.

The main component of donkey meat is skeletal muscle, and different muscle fibers have been found to be associated with meat quality. However, RNA-seq technology has yet to be used to profile the transcriptomic changes of different muscles of the donkey. In this study, the characterizations of different muscles on the gene expression profiles of Dezhou donkey were obtained, the aim was to identify the important genes in donkey muscles, and aid in improving donkey meat quality via RNA-seq. In the donkey gluteus (DG) and donkey longissimus dorsi (DL) group, GO enrichment indicated that DEGs were mainly involved in the biological regulation and metabolic process, and KEGG analysis shows that a total of 427 DEGs were mapped to 216 KEGG pathways and 23 KEGG pathways were significantly enriched such as the ribosome, glycolysis/gluconeogenesis, glucagon signaling pathway and biosynthesis of amino acids pathways. Meanwhile, 504 DEGs were mapped to 223 KEGG pathways, in which 17 were significantly enriched including cardiac muscle contraction and oxytocin signaling pathway in donkey hamstring muscles (DH) and DL group. In addition, the tenderness in donkey meat might involve muscle fiber type and glucose metabolism, which might profit from the DEGs including MYH1, MYH7, TNNC1, TNNI3, TPM3, ALDOA, ENO3, and PGK1. The genes found in this study will provide some ideas for further understanding the molecular mechanism of donkey meat quality.

What we learnt from parents' death experience: A cross-sectional study of death literacy and parent's death quality among adult children in China.

OBJECTIVES: This study aims at investigating the current status of death literacy and parent's death quality among adult children in China. A cross-sectional survey was conducted to explore the associations between death literacy and parent's death quality and to provide evidence for developing public policies for improving the quality of death and end-of-life care for the population in the Greater Bay Area (GBA) of China. METHODS: A cross-sectional design was adopted. Participants who experienced their father's and/or mother's death were recruited from 5 cities in the GBA of China in 2022. The Good Death Inventory (GDI) and the Death Literacy Index (DLI) were used to investigate the perceived quality of death of the parents of the participants and the death literacy of the participants. RESULTS: A total of 511 participants were recruited. Participants with higher GDI scores were positively associated with DLI scores (p < 0.001). Adult children who had close relationships before their parents' death also had higher levels of DLI. SIGNIFICANCE OF RESULTS: This study investigated death literacy among bereaved adult children in China, filling a gap in the investigation of death literacy among Chinese residents. It found that parents' death experience can have a significant impact on the death literacy of adult children, which may affect their understanding and preparation for their own eventual death. Promotion of family discussion on death, development of community palliative care, and improving public death literacy are urgently needed in China.

Identification of equine herpesvirus 8 in donkey abortion: a case report.

BACKGROUND: Equine herpesvirus-8 (EHV-8) is one of the most economically significant viruses that infect mammals of the genus Equus worldwide, which cause severe respiratory diseases and abortion in horses. However, there is no report of abortion caused by EHV-8 in donkeys. CASE PRESENTATION: The present case report is about a 4-year-old donkey having an abortion and showing a serious respiratory issue on the 296th day of pregnancy. Bacteriological and molecular tests were used to screen possible bacterial/viral pathogens to detect the etiological agent. Salmonella abortus equi, EHV-1, EHV-4, and EAV were all negative in the current study. EHV-8, on the other hand, was the only agent that was isolated and identified. CONCLUSIONS: This was for the first time that EHV-8 had been isolated from a donkey in China. EHV-8 infection can cause abortion in donkeys; therefore, veterinarians and breeders should be aware of it.

A nurse-led multicentre randomized controlled trial on effectiveness and cost-effectiveness of Chinese iSupport for dementia program: A study protocol.

AIMS: To describe a nurse-led multicentre randomized controlled trial protocol developed to evaluate the effectiveness and cost-effectiveness of a Chinese iSupport for Dementia program in Australia and Greater China including mainland China, Taiwan, Hong Kong and Macau. DESIGN: A multicentre randomized controlled trial following the SPIRIT checklist. METHODS: Participants in the study will be recruited from Australia and Greater China and will be randomly assigned to the intervention group or the usual care group. Interventions will include self-learning of the iSupport program, virtual peer support and nurse program facilitator support for 6 months. Primary outcome measures will be the 12-Item Short-Form Health Survey. Secondary outcome measures will include: Revised Scale for Caregiving Self-efficacy; Quality of Social Support Scale; Revised Memory and Behaviour Problem Checklist; the Quality of Life in Alzheimer's Disease-Proxy; usages of care services; and cost-effectiveness of the intervention. Outcomes will be measured at baseline, 6 months and 9 months from the baseline. Caregivers' experiences of the peer support will be explored. This project was funded by the National Foundation for Australia-China Relations, Australian Government (Project ID: NFACR216). The total amount is $440,000 Australian dollars (or £ 236,231). DISCUSSION: Approximately, 20% of people living with dementia in the world live in Australia and Greater China. Older Chinese are usually cared for by family caregivers at home due to the influence of Confucianism. However, free and online psychoeducation programs for this large cohort of caregivers are not available or accessible. The World Health Organization iSupport for Dementia is an evidence-based online psychoeducation program for caregivers. Implementing a culturally adapted Chinese iSupport program will address this gap in supporting caregivers. IMPACT: This study will provide research evidence on effectiveness and cost-effectiveness of an online psychoeducation program for caregivers. Findings will inform policy and practice development.

Design, synthesis and bioactivities evaluation of novel oleanolic acid derivatives as potent PI3K inhibitors.

Oleanolic acid has previously been shown to possess PI3K inhibitory activity, thus, the purpose of this work was to generate a series of derivatives that improve the potency. Twenty rationally designed oleanolic acid derivatives were synthesized and tested the cytotoxicity and PI3K inhibitory activity. The results suggested that attachment of additional structural elements such as association of thiazole group to A ring and insertion of phenylurea group was important for increasing activities. The most active derivative was compound II2, which exhibited PI3K inhibitory activity (IC50 = 58.42 nmol/l) and improved interaction with activity site of PI3K according with docking studies.

Factors influencing caring behaviour among registered nurses during the COVID-19 pandemic in China: A qualitative study using the COM-B framework.

AIM: The aim of this work is to explore the influencing factors of nurses' caring behaviour during the COVID-19 pandemic based on the Capability, Opportunity, Motivation as determinants of Behaviour (COM-B) theoretical framework. BACKGROUND: Nurse caring behaviour is vital to reduce and speed up the healing process of COVID-19 patients. It is important to understand the factors that influence caring behaviour among nurses during the COVID-19 pandemic. Research suggests that when it comes to understanding behaviour, using a theoretical framework is likely to be most effective, and the COM-B framework is a recommended approach. METHODS: Semistructured interviews with 42 nurses working in 11 Chinese cities were conducted, and their verbatim statements were transcribed and analysed using thematic analysis. The results were mapped to COM-B framework. RESULTS: Ten key themes emerged: Capability (professional knowledge and skills, emotional intelligence, cross-cultural care competence); opportunity (resources, organizational culture, social culture); motivation (past experience, character, role, beliefs). CONCLUSIONS: Ten factors were found to influence nurses' caring behaviour. This study added two new influencing factors, social culture and past experiences, that further contributed to the understanding of nurses' care behaviours. IMPLICATIONS FOR NURSING MANAGEMENT: Nurses' caring behaviour is influenced not only by themselves but also by institutions and society, so interventions aiming to improve their caring behaviour should consider these elements. The negative impact of the pandemic on capability factors that influence nurses' caring behaviour should be counteracted as soon as possible.

Expression and role of MIG/CXCR3 axis in mantle cell lymphoma.

Mantle cell lymphoma (MCL) is a unique subtype of B-cell non-Hodgkin lymphoma with a generally aggressive and heterogeneous clinical course. Chemokines are one of the complex components in the tumor microenvironment (TME), and they play a vital role in tumor progression and metastasis. There is no information about the monokine induced by gamma interferon (MIG)/CXC chemokine receptor 3 (CXCR3) axis in patients with MCL. In the present study, we discovered that CXCR3 was highly expressed in MCL tissues and some cell lines including Maver, Z138, and Jeko-1, and significantly associated with clinical factors reflecting high tumor burden in MCL patients. Moreover, elevated serum MIG at diagnosis showed a close relationship with advanced disease and poor prognosis in MCL patients. Additionally, the role of CXCR3 in promoting the proliferation and inhibiting the apoptosis of primary MCL cells and Jeko-1 cells was validated by in vitro experiments. Further research indicated that the MIG/CXCR3 axis mediated MCL cell migration to the TME through the PI3K/AKT signaling pathway. Therefore, the MIG/CXCR3 axis might be a potential target with fewer off-target side effects than other targets in MCL.

Knowledge of palliative care and preference of end of life care: a cross-sectional survey of residents in the Chinese socio-cultural background of Macao.

BACKGROUND: Since the establishment of a hospice in the year 2000 and the development of a palliative care ward in 2019, there is no study examining public's knowledge of palliative care, nor preference of end of life care in Macao. AIM: Targeting Chinese residents of Macao, the current study has 3 goals: i) to understand the level of knowledge of palliative care, ii) to explore the preference of end of life treatments, and iii) to identify the associated factors of the preference of end of life treatments. METHODS: A cross-sectional questionnaire survey was conducted using a structured questionnaire. The study employed non-probability quota sampling through which Macao residents aged 18 and above were recruited between July and September 2020. RESULTS: A total of 737 responses were valid. The average correct rate of palliative care knowledge ranged from 40.4% to 85.5%. Pertaining to end of life treatments, 62.0% of the respondents chose comfort care. However, almost half of the respondents agreed that life-sustaining treatments should not be stopped under any circumstances. Respondents who scored higher in palliative care knowledge and those with secondary and tertiary education were associated factors of choosing comfort care rather than life-sustaining treatments. In addition, respondents who agreed that futile life-sustaining treatments should be stopped were also associated with preference for comfort care. CONCLUSION: The understanding of palliative care amongst Macao residents is inadequate. Despite the public's inclination towards comfort care, it is generally believed that life-sustaining treatments should not be stopped at the end of life. The study results suggest that not only the knowledge of palliative care should be enhanced amongst the general public in Macao, but information about life-sustaining treatments should also be offered to patients and families by healthcare professionals, in aiding end of life treatment decision making.

Cloning, tissue distribution and functional characterization of the donkey (Equus asinus) oligopeptide transporter 2.

Oligopeptide transporter 2 (PepT2) is an important transporter of oligopeptides. In the present study, we describe the molecular cloning, tissue distribution and functional characterization of a donkey (Equus asinus) PepT2. The cloned cDNA sequence was 2202 bp at full length, encoding a 733 amino acid peptide with a molecular weight of 81.9 kDa and a theoretical pI of 8.92. Bioinformatics analysis showed that the deduced peptide sequence possessed all the characteristic features of PepT2. The expression of PepT2 in the kidney and lung was significantly higher than that observed in the ileum, duodenum, jejunum, spleen, liver, heart and stomach. Functional characterization by heterologous expression in Chinese hamster ovary cells showed that the uptake of ß-Ala-Lys-N-7-amino-4-methylcoumarin-3-acetic acid (ß-Ala-Lys-AMCA) by donkey PepT2-Chinese hamster ovary cells was dependent on time, pH and substrate concentration, with a low Km value of 91.51 ± 14.14 µM and a maximum velocity of 41.37 ± 2.193 pmol/min/mg protein. In the present study, for the first time, the expression and functional characteristics of donkey PepT2 were evaluated, the results of which provide new insights and a better understanding of its crucial role in oligopeptide transport in donkeys.

MicroRNA-506 inhibits the proliferation and invasion of mantle cell lymphoma cells by targeting B7H3.

BACKGROUND: Aberrant expression of B7 homologue 3 (B7H3) has been observed in various malignancies. Our previous study demonstrated that knocking down of B7H3 inhibited cell proliferation, invasion and enhanced the therapeutic efficacy of chemotherapy in mantle cell lymphoma (MCL). However, the mechanism regulating of B7H3 expression remains unknown. Here, we present a new regulatory microRNA of B7H3, miR-506, that directly targets B7H3 and may play an inhibitory role in MCL progression. METHODS: The expression of miR-506 and B7H3 was investigated by real-time quantitative PCR (RT-qPCR). B7H3 was confirmed to be a novel direct target gene of miR-506 by a dual-luciferase assay and western blot analysis. MiR-506 overexpression in the Maver and Z138 MCL cell lines was established using lentiviral transduction. Cell counting kit-8, flow cytometry and Transwell assays were used to detect changes in cell proliferation, cycle distribution, migration and invasion, respectively. RESULTS: The RT-qPCR results showed that miR-506 was expressed at a low level, while B7H3 was overexpressed in MCL patients and cell lines. By using a bioinformatics analysis combined with a dual-luciferase assay, we determined that miR-506 could target the 3'-untranslated region (3'-UTR) of B7H3 mRNA. Moreover, miR-506 had a negative regulatory effect on B7H3 expression according to the western blotting and RT-qPCR results. In terms of function, increased expression of miR-506 led to reduced MCL cell proliferation, invasion and migration, caused cell cycle arrested at G0/G1 phase, similar to the effects of B7H3 knockdown. Furthermore, we measured the expression of invasion-related proteins by western blotting and found that miR-506 could reduce MMP-2 and MMP-9 expression in MCL cells. Rescue experiments suggested that the restoration of B7H3 expression in MCL cells reversed the inhibition of proliferation and invasion induced by miRNA-506 overexpression. CONCLUSIONS: Our findings suggest that miR-506 functions as a tumor suppressor miRNA and plays a significant role in inhibiting human MCL cell proliferation and metastasis by suppressing B7H3 expression.

MicroRNA-3178 ameliorates inflammation and gastric carcinogenesis promoted by Helicobacter pylori new toxin, Tip-α, by targeting TRAF3.

BACKGROUND: Helicobacter pylori infection is the main cause of chronic gastritis, peptic ulcer, and gastric cancer. Tip-α is a newly identified carcinogenic factor present in H. pylori. TRAF3 can activate NF-κB by both canonical and noncanonical signaling pathways. In this study, we found that the expression of TRAF3 and NF-κB was upregulated, while microRNA-3178 (miR-3178) was decreased in H. pylori-positive gastric tissues but not in H. pylori-negative tissues. MATERIALS AND METHODS: GES-1 cells were incubated with 12.5 µg/mL recombinant Tip-α (rTip-α) in RPMI1640 for 2 hours. After another 24 hours, the supernatant medium was designed as inflammatory-conditioned medium (ICM) and that from the untreated control cells was designed as untreated control medium. The release of proinflammatory cytokines from GES-1 cells and proliferation of gastric cancer cells was determined by ELISA and CCK-8 kits. Cells were transfected with the mimic, inhibitor, negative control of miR-3178, or TRAF3 siRNA control siRNA. The medium was then replaced with RPMI1640, 12.5 µg/mL rTip-α, and collected, and the total cellular RNA and protein were extracted for the following detection. RESULTS: MiR-3178 mimic prevented the increasement of TRAF3 and hence decreased activation of NF-κB signals, whereas miR-3178 inhibitor could not, in GES-1 cells with Tip-α treatment. The condition medium from miR-3178 mimic transfected GES-1 cells could inhibit proliferation and induce apoptosis of inflammation-related gastric cancer cells SGC7901 and MGC803 by decreasing the production of inflammatory cytokines TNF-α and IL-6, which were secreted by GES-1 cells. CONCLUSIONS: Taken all together, Tip-α might activate NF-κB to promote inflammation and carcinogenesis by inhibiting miR-3178 expression, which directly targeting TRAF3, during H. pylori infection in gastric mucosal epithelial cells.

miR-20a enhances cisplatin resistance of human gastric cancer cell line by targeting NFKBIB.

Drug resistance of cancer cells can be regulated by the dysregulated miRNAs, and sustained NFκB activation also plays an important role in tumor resistance to chemotherapy. Here, we sought to investigate whether there was a correlation between miR-20a and the NFκB pathway to clarify the effects that miR-20a exerted on gastric cancer (GC) chemoresistance. We found that miR-20a was significantly upregulated in GC plasma and tissue samples. In addition, it was upregulated in GC plasma and tissues from patients with cisplatin-resistant gastric cancer cell line SGC7901/cisplatin (DDP). And the upregulation of miR-20a was concurrent with the downregulation of NFKBIB (also known as IκBß) as well as upregulation of p65, livin, and survivin. The luciferase activity suggested that NFKBIB was the direct target gene of miR-20a. Transfection of miR-20a inhibitor could increase NFKBIB level; downregulate the expression of p65, livin, and survivin; and lead to a higher proportion of apoptotic cells in SGC7901/DDP cells. Conversely, ectopic expression of miR-20a dramatically decreased the expression of NFKBIB; increased the expression of p65, livin, and survivin; and resulted in a decrease in the apoptosis induced by DDP in SGC7901 cells. Taken together, our findings suggested that miR-20a could promote activation of the NFκB pathway and downstream targets livin and survivin by targeting NFKBIB, which potentially contributed to GC chemoresistance.

Thymopentin enhances the generation of T-cell lineage derived from human embryonic stem cells in vitro.

Thymopentin is a group of biologically active peptide secreted mainly by the epithelial cells of thymic cortex and medulla. Whether it promotes T cells production from human embryonic stem cells(hESCs) in vitro remains an elusive issue. In the present study, we develop a novel strategy that enhances T-cell lineage differentiation of hESCs in collagen matrix culture by sequential cytokine cocktails treatment combined with thymopentin stimulation. We observed that approximately 30.75% cells expressed CD34 on day 14 of the cultures and expressed the surface markers of erythroid, lymphoid and myeloid lineages. The results of colony assays and gene expressions by RT-PCR analysis also demonstrated that hematopoietic progenitor cells (HPCs) derived from hESCs were capable of multi-lineage differentiation. Further study revealed that culturing with thymopentin treatment, the CD34(+)CD45RA(+)CD7(+) cells sorted from HPCs expressed T-cell-related genes, IKAROS, DNTT, TCRγ and TCRß, and T-cell surface markers, CD3, cytoplasmic CD3, CD5, CD27, TCRγδ, CD4 and CD8. The differentiated cells produced the cytokines including IFN-γ, IL-2 and TNF-α in response to stimulation, providing the evidence for T-cell function of these cells. In conclusion, thymopentin enhances T-cell lineage differentiation from hESCs in vitro by mimicking thymus peptide environment in vivo.

Effect of artificial scotomas on open-loop disparity vergence eye movements.

PURPOSE: To investigate the effect of an artificial scotoma on open-loop disparity vergence responses (DVRs) and vergence control mechanisms, we examined open-loop DVRs to disparity stimuli using monocular artificial scotomas in normal subjects. METHODS: Using a mirror haploscope with two computer monitors, we delivered disparity stimuli on a pair of random dot patterns subtending 40 by 30 degrees at 47 cm from each eye. The scotomas were black circles located in the center of a random dot pattern for the left eye. Eye movements of both eyes were recorded with a magnetic search coil system. RESULTS: We first found that the amplitudes of DVRs were gradually decreased and the latency of DVRs was moderately increased as the size of the scotomas was increased. Second, monocular responses from each eye were symmetrical although the stimuli to each eye were asymmetrical. CONCLUSIONS: The results suggest that the monocular eye movements in disparity vergence are controlled by a binocular central mechanism, not driven separately by monocular inputs in the open-loop window.

Mesoderm is committed to hemato-endothelial and cardiac lineages in human embryoid bodies by sequential exposure to cytokines.

Human embryonic stem (hES) cells can differentiate into cells of the three germ layers in vitro and serve as a powerful resource to study mechanisms involved in cell fate decisions. However, it is difficult to promote the directed and efficient differentiation of hES cells toward a specific lineage. Here we establish a stepwise strategy for generating hemato-endothelial and cardiac precursors from hES cells in single culture conditions. The efficiency of committing hES cells to three cell lineages was significantly higher with our approach than with exposure to single or multiple cytokines. Efficiency was determined using quantitative analysis by gene expression, flow cytometry, and colony assays. Several cytokines were sufficient to drive the efficient differentiation of hES cells into specific lineages. Each of these factors appeared to regulate specific steps of differentiation: BMP4 promoted the efficient formation of mesoderm; bFGF induced the differentiation of these mesodermal precursors to the hemangioblast fate; VEGF and TPO were required for the production of committed hematopoietic progenitors. This stepwise control of differentiation in vitro leads to a high frequency of hemato-endothelial and cardiac precursors derived from hES cells and offers a unique model for studying the molecular and cellular events that regulate hematopoiesis and cardiogenesis.