Developmental Timeline Research Articles

Longitudinal Study of the Emerging Functional Connectivity Asymmetry of Primary Language Regions during Infancy.

Cross-sectional studies of the language system in early infancy suggest that the basic neural mechanisms are in place even before birth. This study represents the first of its kind, using a large longitudinal sample of infants, to delineate the early language-related transition toward interhemispheric functional asymmetry in the brain using resting-state functional MRI. More generally, our findings suggest that increasing interhemispheric functional symmetry in the first year might be a general principle of the developing brain governing multiple functional systems, including those that will eventually become lateralized in adulthood. Although resting-state functional MRI cannot provide direct insights into the developmental mechanisms of language lateralization, this study reveals language-related functional connectivity changes during infancy, marking critical points in the development of the brain's functional architecture.

Research Methods in Healthcare Epidemiology and Antimicrobial Stewardship-Mathematical Modeling.

Mathematical modeling is a valuable methodology used to study healthcare epidemiology and antimicrobial stewardship, particularly when more traditional study approaches are infeasible, unethical, costly, or time consuming. We focus on 2 of the most common types of mathematical modeling, namely compartmental modeling and agent-based modeling, which provide important advantages-such as shorter developmental timelines and opportunities for extensive experimentation-over observational and experimental approaches. We summarize these advantages and disadvantages via specific examples and highlight recent advances in the methodology. A checklist is provided to serve as a guideline in the development of mathematical models in healthcare epidemiology and antimicrobial stewardship. Infect Control Hosp Epidemiol 2016;1-7.

Spontaneous activations follow a common developmental course across primary sensory areas in mouse neocortex.

Spontaneous propagation of spiking within the local neocortical circuits of mature primary sensory areas is highly nonrandom, engaging specific sets of interconnected and functionally related neurons. These spontaneous activations promise insight into neocortical structure and function, but their properties in the first 2 wk of perinatal development are incompletely characterized. Previously, we have found that there is a minimal numerical sample, on the order of 400 cells, necessary to fully capture mature neocortical circuit dynamics. Therefore we maximized our numerical sample by using two-photon calcium imaging to observe spontaneous activity in populations of up to 1,062 neurons spanning multiple columns and layers in 52 acute coronal slices of mouse neocortex at each day from postnatal day (PND) 3 to PND 15. Slices contained either primary auditory cortex (A1) or somatosensory barrel field (S1BF), which allowed us to compare sensory modalities with markedly different developmental timelines. Between PND 3 and PND 8, populations in both areas exhibited activations of anatomically compact subgroups on the order of dozens of cells. Between PND 9 and PND 13, the spatiotemporal structure of the activity diversified to include spatially distributed activations encompassing hundreds of cells. Sparse activations covering the entire field of view dominated in slices taken on or after PND 14. These and other findings demonstrate that the developmental progression of spontaneous activations from active local modules in the first postnatal week to sparse, intermingled groups of neurons at the beginning of the third postnatal week generalizes across primary sensory areas, consistent with an intrinsic developmental trajectory independent of sensory input.

Postnatal development of retrosplenial projections to the parahippocampal region of the rat.

The rat parahippocampal region (PHR) and retrosplenial cortex (RSC) are cortical areas important for spatial cognition. In PHR, head-direction cells are present before eye-opening, earliest detected in postnatal day (P)11 animals. Border cells have been recorded around eye-opening (P16), while grid cells do not obtain adult-like features until the fourth postnatal week. In view of these developmental time-lines, we aimed to explore when afferents originating in RSC arrive in PHR. To this end, we injected rats aged P0-P28 with anterograde tracers into RSC. First, we characterized the organization of RSC-PHR projections in postnatal rats and compared these results with data obtained in the adult. Second, we described the morphological development of axonal plexus in PHR. We conclude that the first arriving RSC-axons in PHR, present from P1 onwards, already show a topographical organization similar to that seen in adults, although the labeled plexus does not obtain adult-like densities until P12.

Altered metabolic activity in the developing brain of rats predisposed to high versus low depression-like behavior

Individual differences in human temperament can increase the risk of psychiatric disorders like depression and anxiety. Our laboratory utilized a rat model of temperamental differences to assess neurodevelopmental factors underlying emotional behavior differences. Rats selectively bred for low novelty exploration (Low Responders, LR) display high levels of anxiety- and depression-like behavior compared to High Novelty Responder (HR) rats. Using transcriptome profiling, the present study uncovered vast gene expression differences in the early postnatal HR versus LR limbic brain, including changes in genes involved in cellular metabolism. These data led us to hypothesize that rats prone to high (versus low) anxiety/depression-like behavior exhibit distinct patterns of brain metabolism during the first weeks of life, which may reflect disparate patterns of synaptogenesis and brain circuit development. Thus, in a second experiment we examined activity of cytochrome C oxidase (COX), an enzyme responsible for ATP production and a correlate of metabolic activity, to explore functional energetic differences in the HR/LR early postnatal brain. We found that HR rats display higher COX activity in the amygdala and specific hippocampal subregions compared to LRs during the first 2weeks of life. Correlational analysis examining COX levels across several brain regions and multiple early postnatal time points suggested desynchronization in the developmental timeline of the limbic HR versus LR brain during the first two postnatal weeks. These early divergent COX activity levels may reflect altered circuitry or synaptic activity in the early postnatal HR/LR brain, which could contribute to the emergence of their distinct behavioral phenotypes.

How do clinicians become teachers? A communities of practice perspective.

There is widespread acceptance that clinical educators should be trained to teach, but faculty development for clinicians is undermined by poor attendance and inadequate learning transfer. As a result there has been growing interest in situating teacher development initiatives in clinical workplaces. The relationship between becoming a teacher and clinical workplace contexts is under theorised. In response, this qualitative research set out to explore how clinicians become teachers in relation to clinical communities and institutions. Using communities of practice (CoP) as a conceptual framework this research employed the sensitising concepts of regimes of competence and vertical (managerial) and horizontal (professional) planes of accountability to elucidate structural influences on teacher development. Fourteen hospital physicians completed developmental timelines and underwent semi-structured interviews, exploring their development as teachers. Despite having very different developmental pathways, participants' descriptions of their teacher identities and practice that were remarkably congruent. Two types of CoP occupied the horizontal plane of accountability i.e. clinical teams (Firms) and communities of junior doctors (Fraternities). Participants reproduced teacher identities and practice that were congruent with CoPs' regimes of competence in order to gain recognition and legitimacy. Participants also constructed their teacher identities in relation to institutions in the vertical plane of accountability (i.e. hospitals and medical schools). Institutions that valued teaching supported the development of teacher identities along institutionally defined lines. Where teaching was less valued, clinicians adapted their teacher identities and practices to suit institutional norms. Becoming a clinical educator entails continually negotiating one's identity and practice between two potentially conflicting planes of accountability. Clinical CoPs are largely conservative and reproductive of teaching practice whereas accountability to institutions is potentially disruptive of teacher identity and practice.

Effects of Early and Late Bilingualism on Resting-State Functional Connectivity.

Of current interest is how early life experience leaves its footprint on brain structure and function. In this regard, bilingualism provides an optimal way to determine the effects of the timing of language learning because a second language can be learned from birth or later in life. We used resting-state fMRI to look at simultaneous and sequential bilinguals who differed only in age of acquisition, and found stronger connectivity between language and cognitive control regions in bilinguals who learned their two languages simultaneously, a pattern that was associated with more efficient brain activation during speech. Our findings highlight how functional connections in the brain differ depending upon when learning takes place.

Mothers’ Experiences of Children in the Autistic Spectrum in Greece: Narratives of Development, Education and Disability Across their Blogs

Autism occupies a prominent place in scientific research both as a medical and as a socio-cultural phenomenon. Autism is studied as a disorder and a diagnostic label, as an experience of people with autism, their parents and their supporters, and finally as a disability related to stigma and rejection. The purpose of this article is to describe the posted experiences on personal blogs of five mothers who have school-aged children in the autistic spectrum in Greece. The qualitative method of content analysis is used for analysing the personal narratives across their blogs because this method focuses on describing and understanding the presented experiences and acknowledges the central role of the researcher in describing and signifying the issues discussed. The results of the content analysis show that the mothers seem to view autism through a developmental perspective and as they lead efforts for their child’s developmental timeline they are worried about their child’s developmental course and tend to experience high levels of anxiety, depression and burnout. The mothers act as practical scientists and co-therapists, taking an active role in educating and raising their children, finding a school and selecting appropriate interventions. The mothers struggle to obtain quality in education and services, while faced with the absence of technical infrastructure and understaffing in schools, lack of funding, covert or overt practices of acceptance and rejection of people with disabilities in the educational system, the attitudes and ignorance of some educators, and the high cost of private services. These mothers, at first, view autism as a tragedy and within their social environment they face covert or overt rejection since their children are stigmatised as “abnormal”. Later on, the mothers accept their child’s disability as a prerequisite for gaining a new life experience. It seems that the mothers have a mixed perception of disability, which sometimes tends to be closer to the medical model, sometimes to the hybrid model, while other times to the social model of disability.

104 EMBRYO MANIPULATION TECHNIQUES ALTER PRE-IMPLANTATION DEVELOPMENT AND GENE EXPRESSION IN MOUSE EMBRYOS

Micromanipulation techniques are commonly employed with human embryos; however, the long-term effects on growth and development of embryos are unknown. Subjective techniques, such as embryo grading, may not be sensitive enough to show differences in developmental potential and more objective assessments are needed. The objective of this experiment was to evaluate whether manipulation techniques and cryopreservation alter morphologic and gene expression endpoints of embryos. Two-cell mouse embryos were cultured to blastocyst stage and divided into 6 treatment groups: nonmanipulated control (UNMAN; n = 252), laser-assisted hatching (LAH; n = 124), LAH with slow cooling cryopreservation (LAHcryo; n = 78), simulated biopsy (BIOP; n = 90) performed by laser disruption of 1/8 of the embryo’s cellular volume, BIOP with slow cooling cryopreservation (BIOPcryo; n = 91), and BIOP with vitrification (BIOPvit; n = 66). After manipulation or thaw, embryos were cultured 28 h to blastocyst stage. Fully hatched and hatching blastocysts were collected for cell counts and quantitative PCR to assay absolute transcript abundance for Plac8, Glut1, Oct4, and Cox2, 18s rRNA, and Ppia using standard curves generated from serial dilutions of digested plasmids. Data were analysed using ANOVA with Duncan’s post hoc test and significance was defined as P < 0.05. Manipulation groups differed in developmental stage at 28 h postmanipulation (P = 0.03), with a larger percentage of embryos completely hatched in LAH (46%) and BIOP (45%) groups compared to UNMAN (11%). Cryopreservation reduced percentages of completely hatched embryos (LAHcryo = 26%; BIOPcryo = 31%; BIOPvit = 19%). The number of cells per embryo also varied (P < 0.001); UNMAN and LAH groups had similar numbers of blastomeres (UNMAN = 71; LAH = 74), whereas BIOP groups had reduced cell counts (BIOP = 53; BIOPcryo = 56; BIOPvit = 48). Patterns of gene expression varied between groups; the BIOP group had more cDNA per cell (UNMAN = 125 ng cell–1; BIOP = 202 ng cell–1; P = 0.004), whereas BIOPcryo group did not show this effect (BIOPcryo = 111 ng cell–1). Transcript abundance of Cox2, Oct4, and Glut1 per embryo was significantly decreased (P < 0.05) in biopsied embryos that were cryopreserved, either by slow-cooling or vitrification (Cox2: UNMAN = 643, BIOP = 490, BIOPcryo = 259, BIOPvit = 268; Oct4: UNMAN = 266, BIOP = 181, BIOPcryo = 95, BIOPvit = 97; Glut1: UNMAN = 643, BIOP = 490, BIOPcryo = 259, BIOPvit = 268). The data suggests that micromanipulation alters developmental timelines and gene expression of embryos. While manipulations differ in degree and nature of effect, our investigation implies all manipulations have some effect on the transcriptome of the developing embryo. Differences in cDNA quantity in the BIOP group may indicate a stress response or recovery attempt that becomes blunted in biopsied embryos which are subsequently cryopreserved. Thus, our study suggests that cryopreservation of biopsied embryos may come at a price and offers scientific support for only judiciously selected and medically indicated embryo biopsies.

Young children's early sensitivity to linguistic indications of speaker certainty in their selective word learning

In everyday conversation, both children and adults have an expectation that the speaker is telling the truth. In reality, however, this expectation is not always fulfilled, and both children and adults are equipped with a capacity for epistemic vigilance, i.e. a capacity to assess the speaker's trustworthiness in order to avoid being misinformed. The hearer's assessment of the speaker's trustworthiness is based on two criteria: his ability to provide true information and his benevolence toward the hearer. In two studies, we investigated how young children use these criteria, by focusing on two indicators of trustworthiness: linguistic expressions of speaker certainty, and personal familiarity. In the first study, both 3- and 4-year-olds were successful in distinguishing the degree of speaker certainty expressed by linguistic indicators and using it to assess the trustworthiness of the speaker. In the second study, children's ability to assess the speaker's trustworthiness on the basis of his attitude of certainty was further scrutinized. When pitted against personal familiarity, children's bias toward the certain speaker was modified in 5-year-olds but not 3 year-olds. The difference between the two age groups suggests that epistemic vigilance consists of a set of distinct components, with different developmental timelines.

Preimplantation development of cloned canine embryos recovered by hysterectomy or surgical uterine flushing and subsequent pregnancy outcomes

Dog cloning offers a substantial potential because of the advancements in assisted reproductive technology and development of the human disease model in line with the transgenic technique. However, little is known about the development of the canine cloned embryo during the preimplantation period. The aim of this study was to investigate the most efficient method and time for collecting cloned canine preimplantation embryos and to ascertain the developmental timeline of cloned canine embryos. Two hundred cloned embryos were created and transferred into 11 surrogates. The preimplantation stage cloned embryos were then collected on Days 7, 8, and 9 using an ovariohysterectomy or the Foley balloon catheter method. The recovery rate of reconstructed embryos was 63.6% and 60.6% for the ovariohysterectomy and Foley balloon catheter methods, respectively. Although significant differences were observed in the early developmental stages (one-cell and 16-cell stages), no significant difference was observed in the blastocyst stage. Significantly higher blastocyst rate was observed when the embryos were collected on Day 8 (11.4%) than on Day 7 (0.0%; P < 0.05). At the proximal uterine horn on Day 7, no embryos at any stage were found, whereas on Days 8 and 9, blastocysts were found. We have observed a 63% initial pregnancy rate at 25 to 30 days after embryo transfer and a 50% full-term pregnancy rate, whereas 6.3% of the puppies were born, and 5.5% were born live among the total transferred embryos. Our results suggest that cloned embryos can develop to blastocysts by Day 8, and full-term pregnancy can be achieved after embryo transfer in canine.

Abstract B16: Development of a high-throughput imaging screen for the functional assessment of cell-linking moieties using effector and target cells in a cell kill assay

Abstract Cell Linking Moieties (CLMs) are bi-specific antibody fragments that are capable of recognizing epitopes on tumor cells and specific effector cells via unique cell surface receptors. They are comprised of 2 scFv elements recognizing unique epitopes, bound by a linking element. CLMs offer a distinct advantage in that they do not rely on the expression of MHC class I molecules, generation of specific antigenic peptide, or ex vivo manipulation of cells to exert their tumor cell killing effect. To identify the proper orientation of scFv elements and to define the most potent and selective CLM, we have established an image-based screening platform capable of interrogating a large number of CLMs based on their ability to activate effectors and specifically kill tumor cells. We demonstrate the ability to screen a number of CLMs targeting wild type EGFR and HER2 receptors on fluorescently-tagged tumor cell lines for their ability to recruit CD3+ T-cells from unstimulated PBMC pools and mediate selective cell killing. CLMs were created by transient transfection of HEK293 cells with PCR-generated DNA fragments in 96 well plates. Supernatant was harvested 3 days post transfection. Dilutions of crude supernatant were applied to A549, MDA-MB-468, and SW620 (negative) target cells expressing EGFR or HER2 receptors in the presence of unstimulated PBMCs at 10:1 PBMC:Target ratio in 384 well plates. PBMC to target ratios were pre-optimized by running a titration from 2:1 through 1:30 Target:PBMCs in a kill assay. Resulting target cell loss (cell death) was compared to control wells (mock transfected supernatant). In the screening campaign, a primary screen first selects CLM hits based on killing ability, and then a secondary screen is employed to provide dose-responses, IC50s, and additional information, such as non-specific killing of negative lines. Using this image-based screen, consistent Z-scores above 0.5 were obtained, which corresponds to 12 standard deviations between the positive and negative controls, indicating an excellent dynamic range and low variability in the assay. In a proof of concept study using this platform, two EGFR-CD3 CLMs were selected from a larger list and characterized further in the secondary screen. In the top candidate, secondary screening resulted in IC50 average values of 1632 and 12,971 - fold dilution of CLM-containing HEK293 supernatant in A549 cells, and MDA-MB-468 cells, respectively. At high doses of top-candidate CLMs, no target cells remained in PBMC co-cultures, representing a near 100% killing effect. No killing was observed in the negative control line, SW620. Consistent ranking of CLM candidates was observed among 4 donors of PBMCs evaluated. In conclusion, this image-based screening platform allows for well- and cell-level killing information to be obtained with specific loss of target cells in complex mixtures to be accurately calculated without the presence of radioactive compounds like 51Cr. Furthermore, this method allows for kinetic analysis where the same well can be scanned and analyzed at multiple timepoints in the assay to understand the dynamics of killing activity. Lastly, the development of a specific and selective high throughput functional screening assay using non-terminal high content fluorescent imaging to rapidly select CLM-T cell hits results in a shortening of the developmental time line. Citation Format: Jeffrey Rosenbloom, Jason Isaacson, Srinivas Rengarajan, Paul Szymanski, Jennifer Buenviaje, Kristi Elliott, Francois Lebel, John A. Barrett, Richard Einstein. Development of a high-throughput imaging screen for the functional assessment of cell-linking moieties using effector and target cells in a cell kill assay. [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy: A New Chapter; December 1-4, 2014; Orlando, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2015;3(10 Suppl):Abstract nr B16.

Challenges in the translation and commercialization of cell therapies.

BackgroundCell therapies are an emerging form of healthcare that offer significant potential to improve the practice of medicine and provide benefits to patients who currently have limited or no treatment options. Ideally, these innovative therapies can complement existing small molecule, biologic and device approaches, forming a so-called fourth pillar of medicine and allowing clinicians to identify the best treatment approach for each patient. Despite this potential, cell therapies are substantially more complex than small molecule or biologic interventions. This complexity poses challenges for scientists and firms developing cell therapies and regulators seeking to oversee this growing area of medicine.ResultsIn this project, we retrospectively examined the development of seven cell therapies – including three autologous interventions and four allogeneic interventions – with the aim of identifying common challenges hindering attempts to bring new cell therapies to market. We complemented this analysis with a series of qualitative interviews with experts in various aspects of cell therapy. Through our analysis, which included review of extant literature collected from company documents, newspapers, journals, analyst reports and similar sources, and analysis of the qualitative interviews, we identified several common challenges that cell therapy firms must address in both the pre- and post-market stages. Key pre-market challenges included identifying and maintaining stable funding to see firms through lengthy developmental timelines and uncertain regulatory processes. These challenges are not unique to cell therapies, of course, but the novelty of cell-based interventions complicates these efforts compared to small molecule or biologic approaches. The atypical nature of cell therapies also led to post-market difficulties, including challenges navigating the reimbursement process and convincing providers to change their treatment approaches. In addition, scaling up production, distributing cell therapies and managing the costs of production were challenges that started pre-market and continued into the post-market phase.ConclusionsOur analysis highlights several interrelated challenges hindering the development of cell therapies. Identifying strategies to address these challenges may accelerate the development and increase the impact of novel cell therapies.

Fifteen-month-old infants use velocity information to predict others’ action targets

In a world full of objects, predicting which object a person is going to grasp is not easy for an onlooker. Among other cues, the characteristics of a reaching movement might be informative for predicting its target, as approach movements are slower when more accuracy is required. The current study examined whether observers can predict the target of an action based on the movement velocity while the action is still unfolding, and if so, whether these predictions are likely the result of motor simulation. We investigated the role of motor processes for velocity-based predictions by studying participants who based on their age differed in motor experience with the task at hand, namely reaching. To that end, 9-, 12-, and 15-month-old infants and a group of adults participated in an eye-tracking experiment which assessed action prediction accuracy. Participants observed a hand repeatedly moving toward and pressing a button on a panel, one of which was small, the other one large. The velocity of the reaching hand was the central cue for predicting which button would be the target of the observed action as the velocity was lower when reaching for the small compared to the large button. Adults and 15-month-old infants made more frequent visual anticipations to the close button when it was the target than when it was not and were thus able to use the information in the speed of the approach movement for the prediction of the action target. The 9- and 12-month-olds, however, did not display this difference. After the eye-tracking experiment, infants’ ability to aim for and press buttons of different sizes was evaluated. Results showed that the 15-month-olds were more proficient than the 9- and 12-month-olds in performing the reaching actions. The developmental time line of velocity-based action predictions thus corresponds to the development of performing that motor act yourself. Taken together, these data suggest that motor simulation may underlie velocity-based predictions.

Identifying low-level sequence variants via next generation sequencing to aid stable CHO cell line screening.

Developing stable Chinese hamster ovary (CHO) cell lines for biotherapeutics is an irreversible process and therefore, key quality attributes, such as sequence variants, must be closely monitored during cell line development (CLD) to avoid delay in the developmental timeline, and more importantly, to assure product safety and efficacy. Sequence variants, defined as unintended amino acid substitution in recombinant protein primary structure, result from alteration at either the DNA or the protein level. Here, for the first time, we report the application of transcriptome sequencing (RNAseq) in an IgG1 monoclonal antibody (mAb) CLD campaign to detect, identify, and eliminate cell lines containing low-level point mutations in recombinant coding sequence. Among the top eleven mAb producers chosen from transfectant, clone or subclone stages, three of the cell lines contained either missense or nonsense point mutations at a low level of less than 2%. Subsequent LC/MS/MS characterization detected ∼3% sequence variants with an amino acid change from Ser to Leu at residue 117 in the heavy chain of transfectants 11 and 27. This substitution is consistent with the RNAseq finding of a C/T mutation located at 407 base pair (TCA→TTA) in the heavy chain coding sequence. Here we demonstrate that RNAseq is a rapid and highly sensitive method to identify low-level genetic mutation de novo corresponding to the amino acid substitution that elicits sequence variant(s). Its implementation in CLD constitutes an early and effective step in identifying desired CHO expression cell lines.

Identification and characterization of a novel inflammatory DC precursor (HEM5P.235)

Abstract DC differentiated through culture with GM-CSF are used in many clinically promising applications including vaccines. However, the developmental timeline during which specific stimulatory or immunosuppressive functions are acquired by these cells is poorly understood. Here, we developed a method of isolating progenitor populations at specific stages of development to monitor their phenotype and function. Bone marrow cells were cultured in GM-CSF for three days, then sorted based on Ly6c and CSF-1R (CD115) expression, two hallmarks of myeloid cell development. We then monitored the developmental progression and differentiation of each population based on the expression of these proteins as well as several other hallmarks of the dendritic cell phenotype. We measured their gene expression profiles by qRT-PCR and their response to inflammatory stimuli at each stage of development. Through this analysis, we have identified five distinct cell types representative of Common Myeloid Progenitors (CMP), Granulocyte Macrophage Progenitors (GMP), Monocytes, inflammatory DC (iDC), and a novel dendritic cell precursor which is phenotypically and functionally distinct from previously described myeloid cells. Our findings suggest this novel cell type, Inflammatory DC precursor (IDP), arises from monocytes and serves as an immediate precursor to immature inflammatory DCs. These studies will aid in the refinement of protocols to acquire cells for specific clinical applications.

Challenges in the translation and commercialization of cellular therapies

Background: Cell therapies are an emerging form of healthcare that offer significant potential to improve the practice of medicine and provide benefits to patients who currently have limited or no treatment options. Ideally, these innovative therapies can complement existing small molecule, biologic and device approaches, forming a so-called fourth pillar of medicine and allowing clinicians to identify the best treatment approach for each patient. Despite this potential, cell therapies are substantially more complex than small molecule or biologic interventions. This complexity poses challenges for scientists and firms developing cell therapies and regulators seeking to oversee this growing area of medicine. Results: In this project, we retrospectively examined the development of seven cell therapies – including three autologous interventions and four allogeneic interventions – with the aim of identifying common challenges hindering attempts to bring new cell therapies to market. We complemented this analysis with a series of qualitative interviews with experts in various aspects of cell therapy. Through our analysis, which included review of extant literature collected from company documents, newspapers, journals, analyst reports and similar sources, and analysis of the qualitative interviews, we identified several common challenges that cell therapy firms must address in both the pre- and post-market stages. Key pre-market challenges included identifying and maintaining stable funding to see firms through lengthy developmental timelines and uncertain regulatory processes. These challenges are not unique to cell therapies, of course, but the novelty of cell-based interventions complicates these efforts compared to small molecule or biologic approaches. The atypical nature of cell therapies also led to post-market difficulties, including challenges navigating the reimbursement process and convincing providers to change their treatment approaches. In addition, scaling up production, distributing cell therapies and managing the costs of production were challenges that started pre-market and continued into the post-market phase. Conclusions: Our analysis highlights several interrelated challenges hindering the development of cell therapies. Identifying strategies to address these challenges may accelerate the development and increase the impact of novel cell therapies.

Importance of maternal diabetes on the chronological deregulation of the intrauterine development: an experimental study in rat.

We investigated whether maternal diabetes induced in rats using streptozotocin (STZ) on Day 5 of pregnancy affects the intrauterine developmental timeline. A total of 30 pregnant Sprague-Dawley diabetic rats (DRs) and 20 control rats (CRs) were used to obtain 21-day fetuses (F21) and newborn (NB) pups. Gestational age, weight, and body size were recorded as were the maxillofacial morphometry and morphohistological characteristics of the limbs. In DRs, pregnancy continued for ∼1.7 days, and delivery occurred 23 days postcoitus (DPC). In this group, the number of pups was lower, and 13% had maxillofacial defects. F21 in the DR group had lower weights and were smaller; moreover, the morphological characteristics of the maxillofacial structures, derived from the neural crest, were discordant with their chronological gestational age, resembling 18- to 19-day-old fetuses. These deficiencies were counterbalanced in NB pups. We conclude that hyperglycemia, which results from maternal diabetes and precedes embryo implantation, deregulates the intrauterine developmental timeline, restricts embryo-fetal growth, and primarily delays the remodeling and maturation of the structures derived from neural crest cells.

Diversity in life history of queen and worker honey bees, Apis mellifera L.

Queen and worker European honey bees (Apis mellifera L.) have similar growth trends but differ greatly in their morphology, physiology, function and developmental timeline. Here, the life history of queen and worker bees was characterized, and reference pictures are provided. The developmental rate of workers was found to differ as much as 3days, even if the two types of bees were laid within 12h of each other. We also present some interesting phenomena with regards to the developmental stages of queen and worker bees.

Sex differences in spatial navigation and perception in human adolescents and emerging adults

Males typically outperform females on spatial tasks, beginning early in life and continuing into adulthood. This study aimed to characterize age and sex differences in human spatial ability using a virtual Water Maze Task (vWMT), which is based on the classic Morris water maze spatial navigation task used in rodents. Performance on the vWMT and on a task assessing visuospatial perception, Mental Rotations Test (MRT), was examined in 33 adolescents and 39 emerging adults. For the vWMT, significant effects of age and sex were observed for path length in the target region (narrower spatial sampling), and heading error, with emerging adults performing better than adolescents, and an overall male advantage. For the MRT, males scored higher than females, but only in emerging adulthood. Overall, sex differences in visuospatial perception (MRT) emerge differently from those observed on a classic navigation task, with age and sex-specific superior vWMT performance likely related to the use of more efficient strategies. Importantly, these results extend the developmental timeline of spatial ability characterization to include adolescent males and females performing a virtual version of the classic vWMT.