Targeted mutagenesis of specific genomic DNA sequences in animals for the in vivo generation of variant libraries.

Understanding how the number, placement and affinity of transcription factor binding sites dictates gene regulatory programs remains a major unsolved challenge in biology, particularly in the context of multicellular organisms. To uncover these rules, it is first necessary to find the binding sites within a regulatory region with high precision, and then to systematically modulate this binding site arrangement while simultaneously measuring the effect of this modulation on output gene expression. Massively parallel reporter assays (MPRAs), where the gene expression stemming from 10,000s of in vitro-generated regulatory sequences is measured, have made this feat possible in high-throughput in single cells in culture. However, because of lack of technologies to incorporate DNA libraries, MPRAs are limited in whole organisms. To enable MPRAs in multicellular organisms, we generated tools to create a high degree of mutagenesis in specific genomic loci in vivo using base editing. Targeting GFP integrated in genome of Drosophila cell culture and whole animals as a case study, we show that the base editor AIDevoCDA1 stemming from sea lamprey fused to nCas9 is highly mutagenic. Surprisingly, longer gRNAs increase mutation efficiency and expand the mutating window, which can allow the introduction of mutations in previously untargetable sequences. Finally, we demonstrate arrays of >20 gRNAs that can efficiently introduce mutations along a 200bp sequence, making it a promising tool to test enhancer function in vivo in a high throughput manner.

Functional plasticity of the swim bladder as an acoustic organ for communication in a vocal fish.

Teleost fishes have evolved a number of sound-producing mechanisms, including vibrations of the swim bladder. In addition to sound production, the swim bladder also aids in sound reception. While the production and reception of sound by the swim bladder has been described separately in fishes, the extent to which it operates for both in a single species is unknown. Here, using morphological, electrophysiological and modelling approaches, we show that the swim bladder of male plainfin midshipman fish (Porichthys notatus) exhibits reproductive state-dependent changes in morphology and function for sound production and reception. Non-reproductive males possess rostral 'horn-like' swim bladder extensions that enhance low-frequency (less than 800 Hz) sound pressure sensitivity by decreasing the distance between the swim bladder and inner ear, thus enabling pressure-induced swim bladder vibrations to be transduced to the inner ear. By contrast, reproductive males display enlarged swim bladder sonic muscles that enable the production of advertisement calls but also alter swim bladder morphology and increase the swim bladder to inner ear distance, effectively reducing sound pressure sensitivity. Taken together, we show that the swim bladder exhibits a seasonal functional plasticity that allows it to effectively mediate both the production and reception of sound in a vocal teleost fish.

Does the model reflect the system? When two-dimensional biomechanics is not 'good enough'.

Models are mathematical representations of systems, processes or phenomena. In biomechanics, finite-element modelling (FEM) can be a powerful tool, allowing biologists to test form-function relationships in silico, replacing or extending results of in vivo experimentation. Although modelling simplifications and assumptions are necessary, as a minimum modelling requirement the results of the simplified model must reflect the biomechanics of the modelled system. In cases where the three-dimensional mechanics of a structure are important determinants of its performance, simplified two-dimensional modelling approaches are likely to produce inaccurate results. The vertebrate mandible is one among many three-dimensional anatomical structures routinely modelled using two-dimensional FE analysis. We thus compare the stress regimes of our published three-dimensional model of the chimpanzee mandible with a published two-dimensional model of the chimpanzee mandible and identify several fundamental differences. We then present a series of two-dimensional and three-dimensional FE modelling experiments that demonstrate how three key modelling parameters, (i) dimensionality, (ii) symmetric geometry, and (iii) constraints, affect deformation and strain regimes of the models. Our results confirm that, in the case of the primate mandible (at least), two-dimensional FEM fails to meet this minimum modelling requirement and should not be used to draw functional, ecological or evolutionary conclusions.

Value of Early Post-Operative Growth Hormone Testing in Predicting Long-Term Remission and Residual Disease after Transsphenoidal Surgery for Acromegaly.

INTRODUCTION: Surgical remission for acromegaly is dependent on a number of factors including tumour size, invasiveness, and surgical expertise. We studied the value of early post-operative growth hormone (GH) level as a predictor of outcome and to guide early surgical re-exploration for residual disease in patients with acromegaly. METHODS: Patients with acromegaly undergoing first-time endoscopic transsphenoidal surgery between 2005 and 2015, in 2 regional neurosurgical centres, were studied. Insulin-like growth factor-1 (IGF-1), basal GH (i.e., sample before oral glucose), and GH nadir on oral glucose tolerance test (OGTT) were tested at various time points, including 2-5 days post-operatively. Definition of disease remission was according to the 2010 consensus statement (i.e., GH nadir <0.4 µg/L during an OGTT and normalized population-matched IGF-1). Forward stepwise logistic regression was used to determine factors associated with remission. RESULTS: We investigated 81 consecutive patients with acromegaly, 67 (83%) of which had macroadenomas and 22 (27%) were noted to be invasive at surgery. Mean follow-up was 44 ± 25 months. Overall, surgical remission was achieved in 55 (68%) patients at final follow-up. On univariate analysis, the remission rates at the end of the study period for patients with early post-operative GH nadir on OGTT of <0.4 (N = 43), between 0.4 and 1 (N = 28), and >1 µg/L (N = 8) were 88, 54, and 20%, respectively. Similar results were seen with basal GH on early post-operative OGTT. On multivariate regression analysis, pre-operative IGF-1 (odds ratio of 13.1) and early post-operative basal GH (odds ratio of 5.0) and GH nadir on OGTT (odds ratio of 6.8) were significant predictors of residual disease. Based on a raised early GH nadir and post-operative MR findings, 10 patients underwent early surgical re-exploration. There was reduction in post-operative GH levels in 9 cases, of which 5 (50%) achieved long-term remission. There was an increased risk of new pituitary hormone deficiencies in patients having surgical re-exploration compared to those having a single operation (60 vs. 14%). CONCLUSIONS: An early post-operative basal GH and GH nadir on OGTT are reliable predictors of long-term disease remission. It can be used to guide patients for early surgical re-exploration for residual disease, although there is increased risk of hypopituitarism.

Comparative biomechanics of the Pan and Macaca mandibles during mastication: finite element modelling of loading, deformation and strain regimes.

The mechanical behaviour of the mandibles of Pan and Macaca during mastication was compared using finite element modelling. Muscle forces were calculated using species-specific measures of physiological cross-sectional area and scaled using electromyographic estimates of muscle recruitment in Macaca. Loading regimes were compared using moments acting on the mandible and strain regimes were qualitatively compared using maps of principal, shear and axial strains. The enlarged and more vertically oriented temporalis and superficial masseter muscles of Pan result in larger sagittal and transverse bending moments on both working and balancing sides, and larger anteroposterior twisting moments on the working side. The mandible of Pan experiences higher principal strain magnitudes in the ramus and mandibular prominence, higher transverse shear strains in the top of the symphyseal region and working-side corpus, and a predominance of sagittal bending-related strains in the balancing-side mandible. This study lays the foundation for a broader comparative study of Hominidae mandibular mechanics in extant and fossil hominids using finite element modelling. Pan's larger and more vertical masseter and temporalis may make it a more suitable model for hominid mandibular biomechanics than Macaca.

Sexual Activity and Depressive Symptoms in Later Life: Insights from Jamaica.

Objectives: To explore relationships between sexual activity and depressive symptoms in urology and gynecology out-patients aged 50 years and older.Methods: Depressive symptoms were assessed using Zung Self-Rating Depression Scale. Sexual activity was measured by interviewer-administered questionnaires assessing relationships, intimacy and sexual function (N = 557). Aging and sexual activity were discussed in focus groups (N = 52).Results: More men (51%) than women (41%) reported engagement in sexual intercourse and approximately 40% of men reported sexual activities in the past 4 weeks. The mean number of sex-related complaints per woman was 1.5 (Standard Deviation, 1.2). Approximately four of every ten men reported difficulty with erectile function. Men placed high value on sexual intercourse while women also embraced other activities. After controlling for demographic and health variables, men who reported sexual activity in the past 4 weeks had depressive symptom scores approximately five points lower than those who reported no sexual activity. Each additional sexual complaint was associated with a two-point increase in depressive symptoms scores in women.Conclusions: Higher depressive symptom scores are associated with reduced sexual activity in men and increased sexual complaints in women. Sexual activities remain important for older adults, despite declining sexual function and men place higher value on sexual intercourse than women.Clinical implications: Mental health assessments and sexual activity history should be included in routine healthcare consultations in persons 50 and over.

Transcription Factor Pit-1 Affects Transcriptional Timing in the Dual-Promoter Human Prolactin Gene.

Gene transcription occurs in short bursts interspersed with silent periods, and these kinetics can be altered by promoter structure. The effect of alternate promoter architecture on transcription bursting is not known. We studied the human prolactin (hPRL) gene that contains 2 promoters, a pituitary-specific promoter that requires the transcription factor Pit-1 and displays dramatic transcriptional bursting activity and an alternate upstream promoter that is active in nonpituitary tissues. We studied large hPRL genomic fragments with luciferase reporters, and used bacterial artificial chromosome recombineering to manipulate critical promoter regions. Stochastic switch mathematical modelling of single-cell time-lapse luminescence image data revealed that the Pit-1-dependent promoter showed longer, higher-amplitude transcriptional bursts. Knockdown studies confirmed that the presence of Pit-1 stabilized and prolonged periods of active transcription. Pit-1 therefore plays an active role in establishing the timing of transcription cycles, in addition to its cell-specific functions.

Caregivers of Older Persons in Jamaica: Characteristics, Burden, and Associated Factors.

OBJECTIVE: The objective of this study was to determine and characterize caregiver burden among caregivers of community-dwelling older persons in Jamaica. METHOD: A nationally representative cross-sectional study was done among persons providing noninstitutional care for a single person (≥60 years). The Zarit Burden Interview (ZBI) and a structured questionnaire were administered to 180 caregivers from four geographic health regions. RESULTS: The ZBI scores ranged from 0 to 56 (median = 15). Independently associated factors were relationship to care recipient and age. Children/grandchildren had higher caregiver burden scores than formally employed caregivers (odds ratio = 2.9: 95% confidence interval: [1.02, 8.34]). Compared with caregivers 35 to 44 years, those aged 45 to 65 were almost 5 times more likely to report higher caregiver burden scores. CONCLUSION: Caregiver burden as identified by the ZBI was low. Age (45-65 years) and being the child/grandchild of the care recipient were independently associated with greater caregiver burden. Interventions to address caregiver burden must embrace strategies that recognize that these factors.

Socio-demographic, Health and Functional Status Correlates of Caregiver Burden Among Care Recipients Age 60 Years and Older in Jamaica.

The provision of care to older persons can impose significant burden on those providing care, burdens influenced by care recipient characteristic, caregiver attributes and availability of social support. This paper focuses on identifying relationships between caregiver burden and the socio-demographic, health and functional status attributes of care recipients age 60 years and older in Jamaica. A nationally representative cross-sectional study was done among persons providing non-institutional care for a single person 60 years and older. Data were obtained from a total of 180 caregivers from the four geographic health regions of Jamaica using the Zarit Burden Interview and a 44-question structured questionnaire. Associations between caregiver burden and socio-demographic, health and functional status of care recipients were examined and logistic regression applied to ascertain independent predictors of caregiver burden. The results revealed statistically significant relationships between caregiver burden and care recipients' receipt of conditional cash transfer grants and the ability to toilet independently. In multivariate analysis, ability to toilet remained a significant predictor of caregiver burden-Caregivers who had care recipients who were able to toilet independently were 71% less likely to have mild to severe caregiver burden compared to those who had care recipients that were not able to toilet (OR 0.29; 95% CI 0.14-0.57). Families, health care providers, social workers, state actors and caregivers should take this into account as they develop strategies to mitigate associated caregiver burden.

Calcium dynamics and chromatin remodelling underlie heterogeneity in prolactin transcription.

Pituitary cells have been reported to show spontaneous calcium oscillations and dynamic transcription cycles. To study both processes in the same living cell in real time, we used rat pituitary GH3 cells stably expressing human prolactin-luciferase or prolactin-EGFP reporter gene constructs loaded with a fluorescent calcium indicator and measured activity using single-cell time-lapse microscopy. We observed heterogeneity between clonal cells in the calcium activity and prolactin transcription in unstimulated conditions. There was a significant correlation between cells displaying spontaneous calcium spikes and cells showing spontaneous bursts in prolactin expression. Notably, cells showing no basal calcium activity showed low prolactin expression but elicited a significantly greater transcriptional response to BayK8644 compared to cells showing basal calcium activity. This suggested the presence of two subsets of cells within the population at any one time. Fluorescence-activated cell sorting was used to sort cells into two populations based on the expression level of prolactin-EGFP however, the bimodal pattern of expression was restored within 26 h. Chromatin immunoprecipitation showed that these sorted populations were distinct due to the extent of histone acetylation. We suggest that maintenance of a heterogeneous bimodal population is a fundamental characteristic of this cell type and that calcium activation and histone acetylation, at least in part, drive prolactin transcriptional competence.

A Phase I Study of Everolimus and Bendamustine in Patients With Relapsed/Refractory Lymphoid Hematologic Malignancies.

INTRODUCTION: Everolimus and bendamustine both have single-agent activity against lymphoid hematologic malignancies. We examined this combination in a group of heavily pretreated patients with non-Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL), and multiple myeloma (MM). PATIENTS AND METHODS: In this phase I trial, 18 patients (8 with NHL, 6 with MM, and 4 with HL) were treated with bendamustine 90 mg/m2 on days 1 and 2 and everolimus from 5 to 10 mg daily on a 28-day cycle, for up to 4 cycles. RESULTS: Adverse events were generally mild and mostly hematologic in nature. The most frequent grade 3/4 adverse events were lymphopenia (61%), thrombocytopenia (22%), leukopenia (22%), neutropenia (17%), and fatigue (17%). Overall response rate varied by malignancy: diffuse large B-cell lymphoma, 20% (1 of 5 patients); HL (2 of 4 patients), 50%; MM, 80% (4 of 5 patients); and indolent lymphomas, 100% (3 of 3 patients). The maximum tolerated dose of everolimus was determined to be 7.5 mg daily. CONCLUSION: The combination of everolimus and bendamustine appeared to be well-tolerated and relatively efficacious.

Palatal Biomechanics and Its Significance for Cranial Kinesis in Tyrannosaurus rex.

The extinct nonavian dinosaur Tyrannosaurus rex, considered one of the hardest biting animals ever, is often hypothesized to have exhibited cranial kinesis, or, mobility of cranial joints relative to the braincase. Cranial kinesis in T. rex is a biomechanical paradox in that forcefully biting tetrapods usually possess rigid skulls instead of skulls with movable joints. We tested the biomechanical performance of a tyrannosaur skull using a series of static positions mimicking possible excursions of the palate to evaluate Postural Kinetic Competency in Tyrannosaurus. A functional extant phylogenetic bracket was employed using taxa, which exhibit measurable palatal excursions: Psittacus erithacus (fore-aft movement) and Gekko gecko (mediolateral movement). Static finite element models of Psittacus, Gekko, and Tyrannosaurus were constructed and tested with different palatal postures using anatomically informed material properties, loaded with muscle forces derived from dissection, phylogenetic bracketing, and a sensitivity analysis of muscle architecture and tested in orthal biting simulations using element strain as a proxy for model performance. Extant species models showed lower strains in naturally occurring postures compared to alternatives. We found that fore-aft and neutral models of Tyrannosaurus experienced lower overall strains than mediolaterally shifted models. Protractor muscles dampened palatal strains, while occipital constraints increased strains about palatocranial joints compared to jaw joint constraints. These loading behaviors suggest that even small excursions can strain elements beyond structural failure. Thus, these postural tests of kinesis, along with the robusticity of other cranial features, suggest that the skull of Tyrannosaurus was functionally akinetic. Anat Rec, 303:999-1017, 2020. © 2019 Wiley Periodicals, Inc.

Disentangling juxtacrine from paracrine signalling in dynamic tissue.

Prolactin is a major hormone product of the pituitary gland, the central endocrine regulator. Despite its physiological importance, the cell-level mechanisms of prolactin production are not well understood. Having significantly improved the resolution of real-time-single-cell-GFP-imaging, the authors recently revealed that prolactin gene transcription is highly dynamic and stochastic yet shows space-time coordination in an intact tissue slice. However, it still remains an open question as to what kind of cellular communication mediates the observed space-time organization. To determine the type of interaction between cells we developed a statistical model. The degree of similarity between two expression time series was studied in terms of two distance measures, Euclidean and geodesic, the latter being a network-theoretic distance defined to be the minimal number of edges between nodes, and this was used to discriminate between juxtacrine from paracrine signalling. The analysis presented here suggests that juxtacrine signalling dominates. To further determine whether the coupling is coordinating transcription or post-transcriptional activities we used stochastic switch modelling to infer the transcriptional profiles of cells and estimated their similarity measures to deduce that their spatial cellular coordination involves coupling of transcription via juxtacrine signalling. We developed a computational model that involves an inter-cell juxtacrine coupling, yielding simulation results that show space-time coordination in the transcription level that is in agreement with the above analysis. The developed model is expected to serve as the prototype for the further study of tissue-level organised gene expression for epigenetically regulated genes, such as prolactin.

Performance and Receiver Operating Characteristics of the Mini-Mental State Examination Instrument in Detecting Dementia in a Rapidly Aging Developing Country (Jamaica).

OBJECTIVE: To examine the performance of the Mini-Mental State Examination (MMSE) in community-dwelling older persons in a developing country (Jamaica) undergoing rapid population aging. METHODS: An embedded validity study was conducted utilizing participants from a nationally representative sample of 2782 older persons. Standardized MMSE scores were obtained for study participants. A random selection of 170 persons with MMSE scores greater than 20 and 170 persons with scores 20 or less was done. Field staff were trained to apply the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for the diagnosis of dementia. In total, 300 participants (167 participants with MMSE score of 20 or less, 133 participants with scores greater than 20) were assessed and categorized according to dementia status. Performance characteristics of the MMSE tool were determined for study participants and appropriate adjustment and analyses subsequently applied to facilitate extrapolation to the nationally representative sample. RESULTS: The mean MMSE scores for participants with score of 20 and less was 17.1 (standard deviation [SD] = 3.2) and 24.5 (SD = 2.8) for those with scores greater than 20. Dementia was identified in 34 participants. The receiver operating characteristic curve for MMSE scores in relation to dementia diagnosis had an area under the curve value of 0.935 (95% confidence interval, 0.893-0.977). The optimal MMSE cut-point was 18/19 and was consistently so regardless of age category, gender, educational level, and number of chronic illnesses. CONCLUSION: There is merit in using the MMSE examination as a screening tool for dementia in Jamaica. The findings of this study coupled with widespread use and familiarity among practitioners give credence to the MMSE as a reasonable screening tool for dementia in Jamaica-rapidly aging society.

Predictors of Health Service Utilization Among Older Men in Jamaica.

OBJECTIVES: To determine the relative influence of sociodemographic, socioeconomic, psychosocial, and health variables on health service utilization in the last 12 months. METHODS: Data were analyzed for 1,412 men ≥60 years old from a 2012 nationally representative community-based survey in Jamaica. Associations between six health service utilization variables and several explanatory variables were explored. Logistic regression models were used to identify independent predictors of each utilization measure and determine the strengths of associations. RESULTS: More than 75% reported having health visits and blood pressure checks. Blood sugar (69.6%) and cholesterol (63.1%) checks were less common, and having a prostate check (35.1%) was the least utilized service. Adjusted models confirmed that the presence of chronic diseases and health insurance most strongly predicted utilization. A daughter or son as the main source of financial support (vs self) doubled or tripled, respectively, the odds of routine doctors' visits. Compared with primary or lower education, tertiary education doubled [2.37 (1.12, 4.95)] the odds of a blood pressure check. Regular attendance at club/society/religious organizations' meetings increased the odds of having a prostate check by 45%. DISCUSSION: Although need and financial resources most strongly influenced health service utilization, psychosocial variables may be particularly influential for underutilized services.

New and emerging therapies for acute myeloid leukaemia.

The treatment of acute myeloid leukemia (AML) has remained relatively unchanged for the past 3-4 decades with generally poor outcomes, especially in elderly populations unfit for intensive therapy. Recent advancements, however, have identified several cytogenetic and molecular markers that have not only improved prognostication but have also led to the development of several new targeted therapies for specific subpopulations. In 2017, the US Food and Drug Administration approved four new treatments with indications for fms like tyrosine kinase 3 (FLT3)-mutated AML (midostaurin), newly diagnosed or relapsed/refractory CD33+AML (gemtuzumab ozogamicin), newly diagnosed therapy-related AML or AML with myelodysplasia-related changes (CPX-351) and relapsed/refractory AML with an isocitrate dehydrogenase (IDH)2 mutation (enasidenib). These newly approved therapies have demonstrated improved response in their target populations in several pivotal clinical trials with some also demonstrating improved overall survival. Additional novel therapies in development for AML include agents that target B cell lymphoma 2, FLT3, IDH1, the ubiquitination pathway, as well as cell therapy using engineered T cells with chimeric antigen receptors. This review provides a summary of the four newly approved therapies for AML, as well as several promising therapies currently in development.

4,5-Dimethoxy-2-nitrobenzohydrazides and 1-(1-Benzylpiperidin-4-yl)ethan-1-ones as Potential Antioxidant/Cholinergic Endowed Small Molecule Leads.

The objective of this research is to generate leads for developing our ultimate poly-active molecules with utility in central nervous system (CNS) diseases. Indeed, poly-active molecules capable of mitigating brain free radical damage while enhancing acetylcholine signaling (via cholinesterase inhibition) are still being sought for combating Alzheimer's disease (AD). We differentiate "poly-active" agents from "multi-target" ones by defining them as single molecular entities designed to target only specific contributory synergistic pharmacologies in a disease. For instance, in AD, free radicals either initiate or act in synergy with other pharmacologies, leading to disease worsening. For this preliminary report, a total of 14 (i.e., 4,5-dimethoxy-2-nitrobenzohydrazide plus 1-(1-benzylpiperidin-4-yl)ethan-1-one) derivatives were synthesized and screened, in silico and in vitro, for their ability to scavenge free radicals and inhibit acetylcholinesterase (AChE)/butyrylcholinesterase (BuChE) enzymes. Overall, six derivatives (4a, 4d, 4e, 4f, 4g, 9b) exhibited potent (>30%) antioxidant properties in the oxygen radical absorbance capacity (ORAC) assay. The antioxidant values were either comparable or more potent than the comparator molecules (ascorbic acid, resveratrol, and trolox). Only three compounds (4d, 9a, 9c) yielded modest AChE/BuChE inhibitions (>10%). Please note that a SciFinder substance data base search confirmed that most of the compounds reported herein are new, except 9a and 9c which are also commercially available.

Asymmetry between Activation and Deactivation during a Transcriptional Pulse.

Transcription in eukaryotic cells occurs in gene-specific bursts or pulses of activity. Recent studies identified a spectrum of transcriptionally active "on-states," interspersed with periods of inactivity, but these "off-states" and the process of transcriptional deactivation are poorly understood. To examine what occurs during deactivation, we investigate the dynamics of switching between variable rates. We measured live single-cell expression of luciferase reporters from human growth hormone or human prolactin promoters in a pituitary cell line. Subsequently, we applied a statistical variable-rate model of transcription, validated by single-molecule FISH, to estimate switching between transcriptional rates. Under the assumption that transcription can switch to any rate at any time, we found that transcriptional activation occurs predominantly as a single switch, whereas deactivation occurs with graded, stepwise decreases in transcription rate. Experimentally altering cAMP signalling with forskolin or chromatin remodelling with histone deacetylase inhibitor modifies the duration of defined transcriptional states. Our findings reveal transcriptional activation and deactivation as mechanistically independent, asymmetrical processes.