Digital Health Interventions in Older Adult Populations Living With Chronic Disease in High-Income Countries: Protocol for a Scoping Review.

BACKGROUND: Globally, around 80% percent of adults aged 65 years or older are living with at least 1 chronic disease, and 68% percent have 2 or more chronic diseases. Older adults living with chronic diseases require greater health care services, but these health care services are not always easily accessible. Furthermore, the COVID-19 pandemic has resulted in unprecedented changes in the provision of health care services for older adults. During the COVID-19 pandemic, digital health interventions for chronic disease management were developed out of necessity, but the evidence regarding these and developed interventions is lacking. OBJECTIVE: In this scoping review, we aim to identify available digital health interventions such as emails, text messages, voice messages, telephone calls, video calls, mobile apps, and web-based platforms for chronic disease management for older adults in high-income countries. METHODS: We will follow the Arksey and O'Malley framework to conduct the scoping review. Our full search strategy was developed following a preliminary search on MEDLINE. We will include studies where older adults are at least 65 years of age, living with at least 1 chronic disease (eg, cancer, cardiovascular disease, chronic obstructive pulmonary disease, and diabetes), and residing in high-income countries. Digital health interventions will be broadly defined to include emails, text messages, voice messages, telephone calls, video calls, mobile apps, and web-based platforms. RESULTS: This scoping review is currently ongoing. As of March 2023, our full search strategy has resulted in a total of 9901 records. We completed the screening of titles and abstracts and obtained 442 abstracts for full-text review. We are aiming to complete our full-text review in October 2024, data extraction in November 2024, and data synthesis in December 2024. CONCLUSIONS: This scoping review will generate evidence that will contribute to the further development of digital health interventions for future chronic disease management among older adults in high-income countries. More evidence-based research is needed to better understand the feasibility and limitations associated with the use of digital health interventions for this population. These evidence-based findings can then be disseminated to decision-makers and policy makers in other high-income countries. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/49130.

Identity development, attraction, and behaviour of heterosexually identified men who have sex with men: scoping review protocol.

BACKGROUND: Heterosexually identified men who have sex with men (H-MSM) are distinct from other heterosexual men and from gay, bisexual, and other sexual minority men. Specifically, H-MSM experience discordance between their sexual identity (i.e., heterosexual) and behaviours (i.e., sexual encounters with other men). This sexual identity-behaviour discordance can create barriers to obtaining healthcare and social support. Understanding and accepting H-MSM as they self-identify may be necessary to implement effective public health and psychosocial interventions. The aim of the present study is to provide an overview of research on H-MSM. METHODS: A scoping review will be conducted to identify and describe the identity development, attraction, and behaviour of H-MSM. This scoping review will also identify and describe current trends related to the recruitment of H-MSM and recommend directions for future research. Searches will be conducted in Academic Search Complete, APA PsychInfo, CINAHL Plus with full text, Education Research Complete, Gender Studies Database, GenderWatch, Health Source: Nursing/Academic Edition, LGBTQ + Source, MEDLINE, Psychology and Behavioral Sciences Collection, SocINDEX with full text, Sociological Collection, Social Work Abstracts, ProQuest Dissertations and Theses, and ResearchGate. Primary research studies published in peer-reviewed journals will be included. Dissertations and theses that include primary research on H-MSM will also be included. Reference lists, experts in the field, preprint servers, and relevant conferences will also be consulted for extant and in-progress literature. Two reviewers will independently pilot the data extraction form and conduct the title and abstract screening, with consultation from a research librarian. Seven reviewers will then conduct the full-text article screening. Thematic content analysis will guide the review; through independent review and reviewer meetings, themes and subthemes will be identified and reported from the extracted literature. DISCUSSION: This is the first known knowledge synthesis on H-MSM, seeking to better understand sexual identity-behaviour discordance amongst cisgender men. We anticipate that a theoretical framework of H-MSM's sexuality, internal processes, and behaviours will be constructed from this review. Alongside implications for further research with H-MSM, this review may be relevant to sexually transmitted infection public health and to clinicians working in the field of male sexuality. SYSTEMATIC REVIEW REGISTRATION: Open Science Framework: https://doi.org/10.17605/OSF.IO/MVY9H.

Cancer treatment-related decision-making among culturally and linguistically diverse older adults with cancer: A scoping review by the International Society of Geriatric Oncology Nursing and Allied Health Interest Group.

INTRODUCTION: Countries with large economies are observing a growing number of culturally and linguistically diverse (CALD) older adults, many of whom will be affected by cancer. Little is known about the experiences and factors that influence cancer treatment decision-making in this population. The purposes of this scoping review are: (1) to summarize the published literature on cancer treatment-related decision-making with this population; and (2) to identify potential differences in how cancer treatment decisions are made compared to non-CALD older adults with cancer. MATERIALS AND METHODS: We conducted a scoping review following Arksey and O'Malley and Levac methods, Preferred Reporting Items for Systematic Reviews and Meta-Analyses Scoping Review Guidelines. We conducted a comprehensive multidatabase search, screening 1,139 titles/abstracts. Following data abstraction, we analyzed the data using tabular and narrative summary. RESULTS: We extracted data from six studies that met the inclusion criteria: four quantitative and two qualitative; five from the United States and one from Canada. Three themes were identified: (1) barriers to decision-making, (2) the influence of family and friends on decisionmaking, and (3) differences in uptake and types of treatment received between CALD and non-CALD older adults. DISCUSSION: This comprehensive review of treatment decision-making among CALD older adults with cancer highlights the paucity of research in this area. The findings are limited to North American populations and may not represent experiences in other regions of the world. Future research should focus on studying their treatment-related decision-making experiences to improve the quality of care for this vulnerable population.

The Impact of Cognitive Impairment on Treatment Toxicity, Treatment Completion, and Survival among Older Adults Receiving Chemotherapy: A Systematic Review.

Cognitive impairment (CI) is common among older adults with cancer, but its effect on cancer outcomes is not known. This systematic review sought to identify research investigating clinical endpoints (toxicity risk, treatment completion, and survival) of chemotherapy treatment in those with baseline CI. A systematic search of five databases (inception to March 2021) was conducted. Eligible studies included randomized trials, prospective studies, and retrospective studies in which the sample or a subgroup were older adults (aged ≥ 65) screened positive for CI prior to receiving chemotherapy. Risk of bias assessment was performed using the Quality in Prognosis Studies (QUIPS) tool. Twenty-three articles were included. Sample sizes ranged from n = 31 to 703. There was heterogeneity of cancer sites, screening tools and cut-offs used to ascertain CI, and proportion of patients with CI within study samples. Severity of CI and corresponding proportion of each level within study samples were unclear in all but one study. Among studies investigating CI in a qualified multivariable model, statistically significant findings were found in 4/6 studies on survival and in 1/1 study on nonhematological toxicity. The lack of robust evidence indicates a need for further research on the role of CI in predicting survival, treatment completion, and toxicity among older adults receiving chemotherapy, and the potential implications that could shape treatment decisions.

The First Asian, Single-Center Experience of Blastocyst Preimplantation Genetic Diagnosis with HLA Matching in Thailand for the Prevention of Thalassemia and Subsequent Curative Hematopoietic Stem Cell Transplantation of Twelve Affected Siblings.

RESULTS: In 221 cycles from 138 patients (104 cycles requiring HLA matching), 90.5% had embryo(s) biopsied for genetic testing. There were 119 embryo transfers for thalassemia (76) and thalassemia-HLA cases (43), respectively, resulting in overall clinical pregnancy rates of 54.6%, implantation rates of 45.7%, and live birth rates of 44.1%. Our dataset included fifteen PGD-HLA live births with successful HSCT in twelve affected siblings, 67% using umbilical cord blood stem cells (UCBSC) as the only SC source. CONCLUSIONS: We report favorable thalassemia PGD and PGD-HLA laboratory and clinical outcomes from a single center. The ultimate success in PGD-HLA is of course the cure of a thalassemia-affected sibling by HSCT. Our PGD-HLA HSCT series is the first and largest performed entirely in Asia with twelve successful and two pending cures and predominant UCBSC use.

Impact of multiple blastocyst biopsy and vitrification-warming procedures on pregnancy outcomes.

OBJECTIVE: To assess the impact of multiple blastocyst biopsy and vitrification-warming procedures on clinical outcomes. DESIGN: Retrospective study. SETTING: Private fertility clinic. PATIENT(S): Preimplantation genetic diagnosis (PGD) patients undergoing comprehensive chromosome screening, including monogenic disorder and chromosome rearrangement cases. INTERVENTION(S): Warming and transfer of euploid blastocysts biopsied and vitrified-warmed once (group 1 [G1, control]; n = 2,130), biopsied once but vitrified-warmed twice (group 2 [G2]; n = 34), or biopsied and vitrified-warmed twice (group 3 [G3]; n = 29). MAIN OUTCOME MEASURE(S): Thaw (for transfer) survival rate and clinical pregnancy rate (CPR). RESULT(S): The thaw survival rates were 98.4% for G1, 97.3% for G2, and 93.3% for G3, with once biopsied and vitrified-warmed embryos being significantly higher than twice biopsied and vitrified-warmed embryos (G1 vs. G3; P=.032). There was a slight reduction in CPR with an additional vitrification-warming (G1 54.3% vs. G2 47.1%) and larger reduction with an additional embryo biopsy (G2 47.1% vs. G3 31.0%), but neither difference was statistically significant. However, the combined effect of both additional biopsy and vitrification-warming resulted in a significantly reduced CPR (G1 54.3% vs. G3 31.0%; P=.013). CONCLUSION(S): This study indicates that blastocysts biopsied and vitrified-warmed twice have reduced clinical outcomes compared with blastocysts biopsied and vitrified-warmed once. PGD patients should be advised that performing a second biopsy and vitrification-warming in cases of failure to obtain a result from initial biopsy will reduce the chance of pregnancy. Patients with inherited disorders may elect to proceed with the second biopsy and vitrification to avoid transfer of embryos with the genetic condition.

Reproductive outcomes of testicular versus ejaculated sperm for intracytoplasmic sperm injection among men with high levels of DNA fragmentation in semen: systematic review and meta-analysis.

OBJECTIVE: To compare sperm DNA fragmentation (SDF) levels between testicular and ejaculated sperm and to evaluate outcomes of intracytoplasmic sperm injection (ICSI) with the use of testicular (Testi-ICSI) versus ejaculated (Ejac-ICSI) sperm in nonazoospermic men with high SDF. DESIGN: Systematic review and meta-analysis. SETTING: Not applicable. PATIENT(S): Normo- and oligozoospermic men with high levels of SDF in semen subjected to Testi-ICSI or Ejac-ICSI. INTERVENTION(S): Summary mean difference (MD) and odds ratio (OR) were calculated with the use of an inverse variance model and fixed- or random-effects models, respectively. MAIN OUTCOME MEASURE(S): Primary outcomes were SDF levels, clinical pregnancy rates (CPRs), and live birth rates (LBRs). Secondary outcomes were fertilization and miscarriage rates. RESULT(S): Five studies involving 143 patients provided paired SDF rates for testicular and ejaculated sperm, revealing lower SDF in testicular sperm (MD -24.58%). Four studies involving 507 cycles and 3,840 oocytes reported clinical outcomes of Testi-ICSI and Ejac-ICSI. Fertilization rates were not different between sperm sources, but a trend to lower rates was observed with Testi-ICSI. CPRs were higher for Testi-ICSI than for Ejac-ICSI, as were LBRs, whereas miscarriage rates were reduced with Testi-ICSI. CONCLUSION(S): Testicular sperm have lower levels of SDF than ejaculated sperm, with Testi-ICSI for high post-testicular SDF men improving reproductive outcomes compared with Ejac-ICSI. Infertile couples may benefit from Testi-ICSI if male partners have confirmed high SDF in the ejaculate.

Clinical use of monopronucleated zygotes following blastocyst culture and preimplantation genetic screening, including verification of biparental chromosome inheritance.

In assisted reproduction, embryos derived from monopronucleated (1PN) zygotes are considered abnormal and unsuitable for clinical use. Outcomes of 1PN-derived embryos designated for preimplantation genetic screening (PGS) were analysed. These embryos, especially from intracytoplasmic sperm injection (ICSI), were found to have a low developmental potential; 1PN and 2PN day 5 blastocyst development for IVF was 14.8% versus 36.4% (P < 0.0001), and for ICSI, 6.6% versus 34.0% (P < 0.0001), respectively. With the use of comparative genomic hybridization or next-generation sequencing, PGS was successfully carried out for 74 IVF and 32 ICSI 1PN-derived blastocysts, revealing adjusted abnormality rates of 39.7% and 40.6%, respectively. Additionally, 24 female 1PN-derived blastocysts underwent testing for biparental inheritance, with one ICSI-derived embryo demonstrating paternal only contribution, thus presenting a risk for complete hydatidiform molar pregnancy. Single embryo transfer of 20 IVF and six ICSI 1PN-derived blastocysts with no detectable abnormalities resulted in nine clinical pregnancies. Six have been delivered and three are ongoing, with no anomalies reported to date. The limitation of this study is that pronuclear status was determined through one static observation. The results suggest that 1PN-derived embryos, in which euploidy and biparental inheritance have been established, can provide a source of clinically useful embryos.

Derivation of Human Embryonic Stem Cell Lines from Vitrified Human Blastocysts.

Human embryonic stem cells are pluripotent cells typically derived from blastulating embryos that have become excess to clinical needs in assisted reproduction programs. They provide cellular models for embryonic development and disease, and are thought to be useful for future cell replacement therapies and regenerative medicine. Here we describe methods to derive human embryonic stem cell lines. This includes blastocyst cryopreservation using a highly efficient vitrification protocol, the production and use of fibroblast feeder cells, embryo plating and passaging of resulting cellular outgrowths, and cryopreservation of putative stem cells lines.

The original Beckman Coulter Generation II assay significantly underestimates AMH levels compared with the revised protocol.

PURPOSE: Anti-Müllerian hormone (AMH) is used as a marker for ovarian reserve. Since 2011, the standard test for AMH has been the Beckman Coulter Generation (Gen) II assay. However, in July 2013, the protocol was revised due to falsely low readings. The aim of this study was to compare AMH levels measured with the original and revised Gen II assay and to establish a fertile female reference range for the revised protocol. METHODS: Serum AMH levels were measured for 492 natural conception first trimester pregnant women using the original and revised Gen II assay. RESULTS: The original protocol significantly underestimated AMH levels compared with the revised protocol (p < 0.001), the median being 8.4 and 14.2 pmol/L, respectively. In all samples with detectable AMH levels, the revised protocol yielded a higher concentration compared with the original protocol, the magnitude shift ranging from 3.4 to 283.3 % (median 68.0 %). AMH levels measured with the revised protocol were collated to generate an age-specific reference range, with median levels peaking at 27 years then declining with advancing age. The median AMH concentration for ages 20-24 was 17.3 pmol/L, ages 25-29 was 20.5 pmol/L, ages 30-34 was 17.8 pmol/L, ages 35-39 was 10.8 pmol/L, and ages 40-44 was 6.1 pmol/L. CONCLUSIONS: Our study demonstrated that the original Gen II assay significantly underestimated AMH levels, suggesting caution is required when interpreting literature and testing results achieved with this assay. We also established the revised Gen II assay reference range for AMH in women with unassisted proven fertility.

Embryo vitrification using a novel semi-automated closed system yields in vitro outcomes equivalent to the manual Cryotop method.

STUDY QUESTION: Can the equilibration steps prior to embryo vitrification be automated? SUMMARY ANSWER: We have developed the 'Gavi' system which automatically performs equilibration steps before closed system vitrification on up to four embryos at a time and gives in vitro outcomes equivalent to the manual Cryotop method. WHAT IS KNOWN ALREADY: Embryo cryopreservation is an essential component of a successful assisted reproduction clinic, with vitrification providing excellent embryo survival and pregnancy outcomes. However, vitrification is a manual, labour-intensive and highly skilled procedure, and results can vary between embryologists and clinics. A closed system whereby the embryo does not come in direct contact with liquid nitrogen is preferred by many clinics and is a regulatory requirement in some countries. STUDY DESIGN, SIZE, DURATION: The Gavi system, an automation instrument with a novel closed system device, was used to equilibrate embryos prior to vitrification. Outcomes for embryos automatically processed with the Gavi system were compared with those processed with the manual Cryotop method and with fresh (non-vitrified) controls. PARTICIPANTS/MATERIALS, SETTING, METHODS: The efficacy of the Gavi system (Alpha model) was assessed for mouse (Quackenbush Swiss and F1 C57BL/6J x CBA) zygotes, cleavage stage embryos and blastocysts, and for donated human vitrified-warmed blastocysts. The main outcomes assessed included recovery, survival and in vitro embryo development after vitrification-warming. Cooling and warming rates were measured using a thermocouple probe. MAIN RESULTS AND THE ROLE OF CHANCE: Mouse embryos vitrified after processing with the automated Gavi system achieved equivalent in vitro outcomes to that of Cryotop controls. For example, for mouse blastocysts both the Gavi system (n = 176) and manual Cryotop method (n = 172) gave a 99% recovery rate, of which 54 and 50%, respectively, progressed to fully hatched blastocysts 48 h after warming. The outcomes for human blastocysts processed with the Gavi system (n = 23) were also equivalent to Cryotop controls (n = 13) including 100% recovery for both groups, of which 17 and 15%, respectively, progressed to fully hatched blastocysts 48 h after warming. The cooling and warming rates achieved with the Gavi system were 14 136°C/min and 11 239°C/min, respectively. LIMITATIONS, REASONS FOR CAUTION: Testing of the Gavi system described here was limited to in vitro development of embryos from two mouse strains and a limited number of human embryos. Validation of Gavi system advanced production models is now required to confirm the success of semi-automated vitrification, including clinical evaluation of pregnancy outcomes from the transfer of Gavi vitrified-warmed human embryos. WIDER IMPLICATIONS OF THE FINDINGS: The Gavi system has the potential to revolutionize and standardize vitrification of embryos and oocytes. The success of the Gavi system shows that it is possible to semi-automate complicated labour-intensive ART methods and processes, and opens up the possibility for further improvements in clinical outcomes and efficiencies in the ART clinic. STUDY FUNDING/COMPETING INTERESTS: This study was funded by Genea Ltd. S.B., N.M.T., T.T.P., S.J.M., M.C.B. and T.S. are shareholders of Genea Ltd. E.V., C.H., C.L., S.R.L. and S.M.D. are shareholders of Planet Innovation Pty Ltd. The remaining authors are employees of either Genea Ltd. or Planet Innovation Pty Ltd.

Cell lines from morphologically abnormal discarded IVF embryos are typically euploid and unaccompanied by intrachromosomal aberrations.

Routine IVF practices result in the discarding of a significant proportion of embryos due to their unsuitability for transfer or cryopreservation. The present study plated clinically unusable human blastocysts to derive cellular outgrowths for aneuploidy studies and genome-wide analysis of DNA copy number variations, and to evaluate their potential as a source for pluripotent stem cells. Just 79 cellular outgrowths were obtained from 1026 abnormal blastocysts (7.7%), reflecting their low developmental potential. Of these, 13 (16.5%) were karyotypically abnormal and included trisomies frequently detected in miscarriages, each of which was uniform (nonmosaic) and the result of meiotic nondisjunction. Evaluation of submicroscopic DNA gains and losses in 10 diploid cellular outgrowths did not identify increased rates of copy number variations. Five of these outgrowths were shown to express pluripotency markers and could be developed into cell lineages representative of the three germ layers. These data suggest that embryos with chromosomal abnormalities resist cell-line derivation, and mosaic aneuploidy produced from mitotic nondisjunction, common in preimplantation embryos, is likely to be diminished or lost under conditions of diploid cell competition. Furthermore, this work demonstrated that abnormal embryos discarded in IVF programmes can provide a valuable source for pluripotent stem cell lines. During IVF, a large proportion of embryos are clinically unsuitable due to abnormal development and these embryos only have a small chance of achieving a pregnancy. Here we used these abnormal embryos to create cell lines for genetic testing and to determine their potential as stem cells. Of the 1026 abnormal embryos used, 79 (7.7%) created cell lines, reflecting their low developmental potential. Of those, only 16.5% had chromosomal anomalies, a much lower number than expected. This included chromosome abnormalities frequently observed in miscarriages, all of which were found in each cell tested (nonmosaic) and originated from the egg or the sperm as opposed to cell division. In-depth testing of 10 normal cell lines for small DNA gains and losses did not reveal an increased frequency of mutations. Furthermore, five of the cell lines were examined for stem cell properties and found to exhibit the hallmark features of stem cells including their ability to make mature cells from different parts of the body. Our data suggest that embryos with abnormal chromosomes resist making cell lines and that abnormalities that arise during cell division are likely to be lost due to competition with normal cells. We also demonstrated that abnormal embryos usually discarded in IVF programmes can provide a valuable source for stem cell lines.

Single-embryo transfer of vitrified-warmed blastocysts yields equivalent live-birth rates and improved neonatal outcomes compared with fresh transfers.

OBJECTIVE: To compare pregnancy and neonatal outcomes after fresh and vitrified-warmed single-blastocyst transfers. DESIGN: Retrospective study. SETTING: Private in vitro fertilization (IVF) clinic. PATIENT(S): 1,209 infertile patients who underwent a total of 1,157 fresh and 645 vitrified-warmed embryo transfers. INTERVENTION(S): Day-5 single-blastocyst transfers using fresh or vitrified-warmed (Cryotop method) grade I and grade II embryos. MAIN OUTCOME MEASURE(S): Fetal heart pregnancy rate, live-birth rate, gestational age, and live-birth weight. RESULT(S): The overall blastocyst thaw survival rate was 94.4% and was not significantly different between blastocyst grades or developmental stages. Similar clinical outcomes were achieved for fresh and vitrified-warmed blastocyst transfers; for example, grade I blastocysts had a live-birth rate of 52.8% versus 55.3%, respectively, and grade II blastocysts had a rate of 34.9% versus 30.4%, respectively. Significantly improved neonatal outcomes were evident for vitrified-warmed blastocyst transfers for gestational age, being on average 0.3 weeks longer, and for live-birth weight with babies born on average 145 g heavier (3,296 g versus 3,441 g for fresh and vitrified-warmed groups, respectively), as compared with fresh transfers. CONCLUSION(S): Embryo transfer of vitrified-warmed blastocysts yields equivalent live-birth rates and improved neonatal outcomes compared with fresh transfers.

Absence of a major role for the snai1 and snai3 genes in regulating skeletal muscle regeneration in mice.

The Snail gene family encodes DNA-binding zinc finger proteins that function as transcriptional repressors. While the Snai1 and Snai2 genes are required for normal development in mice, Snai3 mutant mice exhibit no obvious abnormalities. The Snai3 gene is expressed at high levels in skeletal muscle. However, we demonstrate by histological analysis that Snai3 null mutant mice exhibit normal skeletal muscle. During hindlimb muscle regeneration after cardiotoxin-mediated injury, the Snai3 null mice exhibited efficient regeneration. To determine whether the Snai3 gene functions redundantly with the Snai1 gene during skeletal muscle regeneration, we performed hindlimb muscle regeneration in mice with skeletal muscle-specific deletion of the Snai1 gene on a Snai3 null genetic background. These mice also exhibited efficient regeneration, demonstrating that there is no major role for the Snai1 and Snai3 genes in regulating skeletal muscle regeneration in mice.

The snail family gene snai3 is not essential for embryogenesis in mice.

The Snail gene family encodes zinc finger-containing transcriptional repressor proteins. Three members of the Snail gene family have been described in mammals, encoded by the Snai1, Snai2, and Snai3 genes. The function of the Snai1 and Snai2 genes have been studied extensively during both vertebrate embryogenesis and tumor progression and metastasis, and play critically important roles during these processes. However, little is known about the function of the Snai3 gene and protein. We describe here generation and analysis of Snai3 conditional and null mutant mice. We also generated an EYFP-tagged Snai3 null allele that accurately reflects endogenous Snai3 gene expression, with the highest levels of expression detected in thymus and skeletal muscle. Snai3 null mutant homozygous mice are viable and fertile, and exhibit no obvious phenotypic defects. These results demonstrate that Snai3 gene function is not essential for embryogenesis in mice.

Fli-1 overexpression in hematopoietic progenitors deregulates T cell development and induces pre-T cell lymphoblastic leukaemia/lymphoma.

The Ets transcription factor Fli-1 is preferentially expressed in hematopoietic tissues and cells, including immature T cells, but the role of Fli-1 in T cell development has not been closely examined. To address this we retrovirally overexpressed Fli-1 in various in vitro and in vivo settings and analysed its effect on T cell development. We found that Fli-1 overexpression perturbed the DN to DP transition and inhibited CD4 development whilst enhancing CD8 development both in vitro and in vivo. Surprisingly, Fli-1 overexpression in vivo eventuated in development of pre-T cell lymphoblastic leukaemia/lymphoma (pre-T LBL). Known Fli-1 target genes such as the pro-survival Bcl-2 family members were not found to be upregulated. In contrast, we found increased NOTCH1 expression in all Fli-1 T cells and detected Notch1 mutations in all tumours. These data show a novel function for Fli-1 in T cell development and leukaemogenesis and provide a new mouse model of pre-T LBL to identify treatment options that target the Fli-1 and Notch1 signalling pathways.

The Notch-regulated ankyrin repeat protein is required for proper anterior-posterior somite patterning in mice.

The Notch-regulated ankyrin repeat protein (Nrarp) is a component of a negative feedback system that attenuates Notch pathway-mediated signaling. In vertebrates, the timing and spacing of formation of the mesodermal somites are controlled by a molecular oscillator termed the segmentation clock. Somites are also patterned along the rostral-caudal axis of the embryo. Here, we demonstrate that Nrarp-deficient embryos and mice exhibit genetic background-dependent defects of the axial skeleton. While progression of the segmentation clock occurred in Nrarp-deficient embryos, they exhibited altered rostrocaudal patterning of the somites. In Nrarp mutant embryos, the posterior somite compartment was expanded. These studies confirm an anticipated, but previously undocumented role for the Nrarp gene in vertebrate somite patterning and provide an example of the strong influence that genetic background plays on the phenotypes exhibited by mutant mice.

Derivation of Huntington's disease-affected human embryonic stem cell lines.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disease caused by an expansion of cytosine-adenine-guanine (CAG) repeats in the Huntingtin gene Htt. To facilitate research into HD, we have derived 4 human embryonic stem cell (hESC) lines containing ≥ 40 CAG repeats in exon 1 of Htt: SIVF017-HD (CAG40), SIVF018-HD (CAG46), SIVF020-HD (CAG48), and SIVF046-HD (CAG45). Additionally, we have derived a normal sibling-matched control for SIVF020-HD, cell line SIVF019. All 5 hESC lines had a normal karyotype, expressed pluripotency markers including Oct4, SSEA3, and Tra-1-81, and could be maintained in culture for multiple (>40) passages. Teratoma studies revealed that the hESC lines were capable of differentiating into cells representative of the 3 germ layers. Furthermore, in vitro neuronal differentiation experiments have confirmed that the hESC lines were able to generate MAP2-positive neuronal cells that express the Htt protein. Combined, these experiments confirm that the cell lines represent pluripotent stem cell lines. These HD-affected hESC lines will be made available to biomedical research laboratories and will provide a valuable tool to investigate the mechanisms and potential treatments for HD.

Derivation of three new human embryonic stem cell lines.

Human embryonic stem cells are pluripotent cells capable of extensive self-renewal and differentiation to all cells of the embryo proper. Here, we describe the derivation and characterization of three Sydney IVF human embryonic stem cell lines not already reported elsewhere, designated SIVF001, SIVF002, and SIVF014. The cell lines display typical compact colony morphology of embryonic stem cells, have stable growth rates over more than 40 passages and are cytogenetically normal. Furthermore, the cell lines express pluripotency markers including Nanog, Oct4, SSEA3 and Tra-1-81, and are capable of generating teratoma cells derived from each of the three germ layers in immunodeficient mice. These experiments show that the cell lines constitute pluripotent stem cell lines.

Temporal regulation of Cre-recombinase activity in Scl-positive neurons of the central nervous system.

The Cre/LoxP system provides a powerful tool to investigate gene function in vivo. This system requires Cre-recombinase expressing mouse lines that permit control of gene recombination in a tissue-specific and time-dependent manner. To allow spatio-temporal gene deletion in specific central nervous system (CNS) neuronal populations, we generated mice with a tamoxifen-inducible Cre (Cre-ER(T)) transgene under control of the Scl/Tal1 neural promoter/enhancer -0.9E3 (-0.9E3CreER(T) transgenic mice). Using Cre-reporter mice we have shown that tamoxifen-mediated Cre-ER(T) recombination in -0.9E3CreER(T) mice recapitulated the anticipated expression pattern of Scl in the caudal thalamus, midbrain, hindbrain, and spinal cord. Cre-mediated recombination was also effectively induced during embryogenesis and marked the same population of neurons as observed in the adult. Additionally, we identified a tamoxifen-independent constitutively active -0.9E3CreER(T) mouse line that will be useful for gene deletion during early neurogenesis. These -0.9E3CreER(T) mice will provide tools to investigate the role of neuronal genes in the developing and mature CNS. CNS.