Effect of In Vitro Enzyme Digestion and Bile Treatment on Milk Extracellular Vesicles Stability.

SCOPE: Milk extracellular vesicles (EVs) are nanosized particles with potential immune bioactivities. This study examines their fate during in vitro infant gastrointestinal digestion (GI). METHODS AND RESULTS: Bovine milk is digested using the in vitro INFOGEST method, adjusted for the infant. To unravel the contribution of digestive enzymes from bile, milk is treated with digestive enzymes, bile, or a combination of both. EVs are collected posttreatment using differential ultracentrifugation. EVs characterization includes electrophoresis, immunoblotting, nanoparticle tracking analysis, and atomic force microscopy. EVs protein markers programmed cell death 6-interacting protein (ALIX), tumor susceptibility gene 101 (TSG101), cluster of differentiation 9 (CD9), and xanthine dehydrogenase (XDH) are detected after gastric digestion (G60), but their signal intensity is significantly reduced by intestinal conditions (p < 0.05). Enzyme digestion, compared to bile treatment (I60 + bile), results in a significant reduction of signal intensities for TSG101 and CD9 (p < 0.05). Nanoparticle tracking analysis shows a significant reduction (p < 0.05) of EV numbers at the end of the intestinal phase. EVs are detected by atomic force microscopy at the end of the intestinal phase, showing that intact EVs can survive upper gut digestion. CONCLUSION: Intact EVs can be found at the end of the intestinal phase. However, digestive enzymes and bile reduce the quantity and characteristics of EVs, with digestive enzymes playing a larger role.

Results of inaugural international Down Syndrome Societal Services and Supports survey.

PURPOSE: We previously designed the Down Syndrome Societal Services and Supports Survey (DS-4S) to measure country-specific supports for people with Down syndrome (DS) across multiple life domains (healthcare, education, policy, independence, and community inclusion). We now report and analyze the results. METHODS: We partnered with international DS consortia, who distributed the DS-4S to 154 cumulative members representing over 100 countries. Organizations were included if they had a holistic focus on the lives of people with DS and if at least 50% of their members either have DS or are family members of people with DS. Factor analysis was used to analyze the results. RESULTS: We received survey responses from 55 different organizations in 50 countries who met inclusion criteria. Each country had complete data for at least 4 of the 5 domains. The lowest 5 scores were from countries in Africa and Asia; the highest 5 scores were in Europe and North America. CONCLUSION: The responses to the DS-4S stratified countries within each surveyed domain. The DS-4S can now be used to track countries' progress over time and to determine which countries have best practices that might be replicated. We will publish the results and update them biennially at www.DownSyndromeQualityOfLife.com.

Down syndrome screening and diagnosis practices in Europe, United States, Australia, and New Zealand from 1990-2021.

Antenatal screening and diagnostic testing for Down syndrome has greatly advanced over the past 30 years. The goal of this manuscript is to provide a review of the availability and accessibility of prenatal services and selective termination policies across Europe, Australia, New Zealand, and the United States for the period 1990-2021. We collected data from academic peer-reviewed journals, governmental documents, not-for-profit organizations, correspondence with experts, and other online sources without language restrictions. Prenatal screening services from 1990-2021 became increasingly available across countries, enabling expectant couples the opportunity to gain more accurate information earlier in the pregnancy before assuming the risk associated with more invasive techniques like CVS or amniocentesis. Many countries also began adopting prenatal screening as a qualification for prenatal diagnosis. As of 2021, at least 76.9% of countries offered full coverage for diagnostic testing for Down syndrome from government funding. Abortion coverage for a Down syndrome diagnosis was covered fully by government funding in 52.4% of countries in 1990, increasing to 73.8% in 2021. Understanding the changing landscape of prenatal services builds the foundation for future investigation into social policies that affect the prevalence of Down syndrome.

Designing an international survey for organisations serving people with Down syndrome.

BACKGROUND: Down syndrome is the most common liveborn genetic condition. However, there are no surveys measuring societal services and supports for people with Down syndrome. We developed a questionnaire so that initiatives could be targeted towards countries most in need of assistance. METHOD: We formed a geographically diverse group of physicians, family members of people with Down syndrome, and members of Down syndrome not-for-profit organisations to create a survey of societal services and supports. We used a modified Delphi method and disseminated the survey to Down syndrome non-profit organisations worldwide. RESULTS: Our survey consists of 61 items categorised within five domains: Education, Community Inclusion, Independence, Healthcare, and Social and Policy Issues. CONCLUSIONS: We developed a survey to measure societal services and supports available to people with Down syndrome as perceived by organisational leaders. Our methods might serve as a blueprint for other populations of people with intellectual and developmental disabilities.

Estimation of the number of people with Down syndrome in Australia and New Zealand.

PURPOSE: Previous research estimated the effect of selective terminations on birth prevalence and population prevalence of people with Down syndrome (DS) in the United States and Europe. This study provides comparative data from Australia and New Zealand. METHOD: The number of live births (LBs) with DS-in the absence of DS-related terminations of pregnancy-was estimated on the maternal age distribution in the general population. Actual LBs were modeled on registry data. We applied constructed survival curves to annual LBs to predict population numbers. RESULTS: For 2016-2020, we estimated 265 annual LBs with DS (1 in 1158) in Australia and 41 annual LBs (1 in 1450) in New Zealand. For this period, the reduction percentage-the net result of DS-related terminations on LB prevalence-was estimated at 66% for Australia, 71% for New Zealand, 62% for Europe (excluding the former East Bloc), and only 32% for the United States. CONCLUSION: The total population of people with DS has been decreasing since 2000 in Europe (West Bloc) and 2011 in New Zealand owing, in large part, to increased selective terminations. By contrast, the population continues to increase, as of 2020, in Australia and the United States.

Estimation of the number of people with Down syndrome in Europe.

We aimed to estimate the nonselective live birth prevalence, actual live birth prevalence, reduction percentage because of selective terminations, and population prevalence for Down syndrome (DS) in European countries. The number of people with DS alive in a country was estimated by first modeling the number of live births of children with DS by year of birth. Subsequently, for these different years of birth, survival curves for people with DS were constructed and then applied to these yearly estimates of live births with DS. For Europe, 2011-2015, we estimate 8,031 annual live births of children with DS, which would have been around 17,331 births annually, absent selective terminations. The estimated reduction of live birth prevalence was, on average, 54%, varying between 0% in Malta and 83% in Spain. As of 2015, we estimate 417,000 people with DS are living in Europe; without elective terminations, there would have been about 572,000 people with DS, which corresponds to a population reduction rate of 27%. Such statistics can be important barometers for prenatal testing trends and resource allocation within countries. Disability awareness initiatives and public policy initiatives can also be better grounded with these more precise estimates.

Estimation of live birth and population prevalence of Down syndrome in nine U.S. states.

For all of the U.S. states with sufficient data, we estimated live birth and population prevalences for Down syndrome (DS). As social service resources vary between states, such data are important for public policy discussions and state planning. We predicted the actual and nonselective live birth prevalence, and population prevalence, for DS in nine U.S. states based on publicly available datasets from the Centers for Disease Control and Prevention and the Integrated Public Use Microdata Series. As of 2010, we estimated a population size for people with DS of 4,554 in MA (population prevalence 1 in 1,440), 6,101 in NJ (1 in 1,443), 14,315 in NY (1 in 1,355), 9,739 in IL (1 in 1,319), 4,354 in IN (1 in 1,491), 7,295 in MI (1 in 1,354), 9,099 in FL (1 in 2,071), 3,014 in KY (1 in 1,442), and 3,596 in AZ (1 in 1,784). The number of people living with DS has steadily increased from 1950 until 2010 in these nine U.S. states. Population prevalence would have been higher absent DS-related elective terminations. Racial and ethnic groups, other than non-Hispanic whites, comprise a growing proportion within these DS communities, particularly among younger-aged persons.

Estimation of the number of people with Down syndrome in the United States.

PURPOSE: An accurate accounting of persons with Down syndrome (DS) has remained elusive because no population-based registries exist in the United States. The purpose of this study was to estimate this population size by age, race, and ethnicity. METHODS: We predicted the number of people with DS in different age groups for different calendar years using estimations of the number of live births of children with DS from 1900 onward and constructing DS-specific mortality rates from previous studies. RESULTS: We estimate that the number of people with DS living in the United States has grown from 49,923 in 1950 to 206,366 in 2010, which includes 138,019 non-Hispanic whites, 27,141 non-Hispanic blacks, 32,933 Hispanics, 6,747 Asians/Pacific Islanders, and 1,527 American Indians/American Natives. Population prevalence of DS in the United States, as of 2010, was estimated at 6.7 per 10,000 inhabitants (or 1 in 1,499). CONCLUSION: Until 2008, DS was a rare disease. In more recent decades, the population growth of people with DS has leveled off for non-Hispanic whites as a consequence of elective terminations. Changes in childhood survival have impacted the age distribution of people with DS, with more people in their fourth, fifth, and sixth decades of life.Genet Med 19 4, 439-447.

Live births, natural losses, and elective terminations with Down syndrome in Massachusetts.

PURPOSE: No studies to date have reported an estimated number of live births, elective terminations, and natural losses (miscarriages and stillbirths) for Down syndrome (DS) in Massachusetts (MA). These numbers would be helpful to estimate how many expectant parents of children with DS need support and the number of live-born children with DS who require services. METHODS: Combining robust data sets, including the Annual Reports of the MA Birth Defects Monitoring Program, we estimated the number of live births, elective terminations, and natural losses with Down syndrome from 1900 to 2010. RESULTS: The live birth prevalence for DS in MA for the most recent years for which data are available (2006-2010) was estimated at 12.4 per 10,000 live births, with a total of approximately 94 live births annually. During this period, an estimated 126 DS-related elective pregnancy terminations were performed in MA annually. As of 2008, the estimated rate at which live births with DS was reduced as a consequence of DS-related elective pregnancy terminations was 49%. CONCLUSION: The reduction of live births with DS is significantly higher in MA than in the rest of the United States as a whole. However, ethnic and racial differences in reduction rates were similar-highest for Asians/Pacific Islanders, followed by non-Hispanic whites, non-Hispanic blacks/Africans, and Hispanics.Genet Med 18 5, 459-466.

Estimates of the live births, natural losses, and elective terminations with Down syndrome in the United States.

The present and future live birth prevalence of Down syndrome (DS) is of practical importance for planning services and prioritizing research to support people living with the condition. Live birth prevalence is influenced by changes in prenatal screening technologies and policies. To predict the future impact of these changes, a model for estimating the live births of people with DS is required. In this study, we combine diverse and robust datasets with validated estimation techniques to describe the non-selective and live birth prevalence of DS in the United States from 1900-2010. Additionally, for the period 1974-2010, we estimate the impact of DS-related elective pregnancy terminations (following a prenatal diagnosis of DS) on the live births with DS. The live birth prevalence for DS in the most recent years (2006-2010) was estimated at 12.6 per 10,000 (95% CI 12.4-12.8), with around 5,300 births annually. During this period, an estimated 3,100 DS-related elective pregnancy terminations were performed in the U.S. annually. As of 2007, the estimated rates at which live births with DS were reduced as a consequence of DS-related elective pregnancy terminations were 30% (95% CI: 27.3-31.9) for the U.S. as a whole. Our results and our model provide data on the impact of elective pregnancy terminations on live births with DS and may provide a baseline from which future trends for live births with DS can be estimated.

Effect of genotype on duodenal expression of nutrient transporter genes in dairy cows.

BACKGROUND: Studies have shown clear differences between dairy breeds in their feed intake and production efficiencies. The duodenum is critical in the coordination of digestion and absorption of nutrients. This study examined gene transcript abundance of important classes of nutrient transporters in the duodenum of non lactating dairy cows of different feed efficiency potential, namely Holstein-Friesian (HF), Jersey (JE) and their F1 hybrid. Duodenal epithelial tissue was collected at slaughter and stored at -80°C. Total RNA was extracted from tissue and reverse transcribed to generate cDNA. Gene expression of the following transporters, namely nucleoside; amino acid; sugar; mineral; and lipid transporters was measured using quantitative real-time RT-PCR. Data were statistically analysed using mixed models ANOVA in SAS. Orthogonal contrasts were used to test for potential heterotic effects and spearman correlation coefficients calculated to determine potential associations amongst gene expression values and production efficiency variables. RESULTS: While there were no direct effects of genotype on expression values for any of the genes examined, there was evidence for a heterotic effect (P < 0.05) on ABCG8, in the form of increased expression in the F1 genotype compared to either of the two parent breeds. Additionally, a tendency for increased expression of the amino acid transporters, SLC3A1 (P = 0.072), SLC3A2 (P = 0.081) and SLC6A14 (P = 0.072) was also evident in the F1 genotype. A negative (P < 0.05) association was identified between the expression of the glucose transporter gene SLC5A1 and total lactational milk solids yield, corrected for body weight. Positive correlations (P < 0.05) were also observed between the expression values of genes involved in common transporter roles. CONCLUSION: This study suggests that differences in the expression of sterol and amino acid transporters in the duodenum could contribute towards the documented differences in feed efficiency between HF, JE and their F1 hybrid. Furthermore, positive associations between the expression of genes involved in common transporter roles suggest that these may be co-regulated. The study identifies potential candidates for investigation of genetic variants regulating nutrient transport and absorption in the duodenum in dairy cows, which may be incorporated into future breeding programmes.

Expression of genes involved in energy homeostasis in the duodenum and liver of Holstein-Friesian and Jersey cows and their F(1) hybrid.

Differences in feed intake and production efficiency in lactating Holstein-Friesian (HF), Jersey (JE), and JE × HF (F(1)) dairy cows have been reported. The liver-gut axis is important in the regulation of energy homeostasis, appetite behaviour, and production efficiency. The objectives of this study were to determine: 1) the effect of dairy cow genotype on the expression profiles of genes involved in energy homeostasis in duodenal and hepatic tissue, and 2) the association between the expression of these genes across both tissues and with economically important production efficiency traits. The expression of 27 candidate genes involved in energy homeostasis, feed intake, and energy storage was measured by qPCR. Duodenal expression of the pro-opiomelanocortin (POMC), glucagon-like peptide 1 receptor (GLP1R), and insulin-like growth factor 1 (IGF1) genes was highest in HF. In contrast, hepatic expression of the leptin receptor (LEPR), insulin-like growth factor 1 receptor (IGF1R), protein kinase, AMP-activated, beta 1 (AMPKB1), and POMC genes was highest in the F(1) cross. In the duodenum, positive correlations were observed between mRNA expression of anorectic peptides (POMC and GLP1R), whereas a negative correlation was detected between orexigenic (ghrelin) and anorectic (peptide YY) gene expression. A negative correlation was observed between duodenal POMC gene expression and both residual feed intake and milk production efficiency traits, while GLP1R gene expression was negatively correlated with milk production efficiency traits. A heterotic effect was observed in hepatic expression of AMKPB1, IGF1R, LEPR, POMC in the F(1) genotype, possibly mediating improved feed efficiency in cross-bred cows. In conclusion, key genes involved in energy homeostasis and appetite behaviour are differentially expressed due to cow genotype in a tissue-dependent fashion. POMC and GLP1R are potential candidate genes for the identification of single nucleotide polymorphisms regulating energetic efficiency in the dairy cow, which may be incorporated into future breeding programmes.

Modelling Down syndrome.

Animal models are extensively used in genetics, neuroscience and biomedical research. Recent studies illustrate the usefulness and the challenges of research utilising genetically engineered mice to explore the developmental biology of Down syndrome. These studies highlight many of the issues at the centre of what we understand about Down syndrome, and may one day point to useful ways to improve quality of life for people living with Down syndrome.

New and old directions.

Improved social and educational opportunities and access to informed healthcare are helping today's generations of people with Down syndrome to achieve more and live longer. This progress is bringing new challenges. Scientific research is steadily improving our understanding of the condition. Future improvements in the lives of people with Down syndrome will require multidisciplinary efforts and more applied or translational research with practical outcomes. In this context, this journal has reviewed the roles it plays in communicating research to specialists and non-specialists, families, practitioners and researchers alike.

Drug treatment improves memory in mice.

Mice that carry additional copies of genes comparable to those present on human chromosome 21 have been shown to perform better on memory tests when treated with drugs that target brain function. Could this be an important break-through in the search for pharmacological therapies to assist people with Down syndrome?

Insemination factors affecting the conception rate in seasonal calving Holstein-Friesian cows.

Differences in conception rate to first service between artificial inseminations (AI) carried out by commercial AI operators (CAI) or do-it-yourself operators (DIY), between natural service (NAT) and AI, between different AI sires, and between fresh and frozen-thawed semen, on Irish commercial dairy farms, were studied using logistic regression. The study comprised 12,933 potential first inseminations from 77 spring-calving dairy herds. The data were recorded during 1999 and 2000. Amongst the total, 4,394 cows had repeated records across the two years. Adjustment variables included: herd, year, parity, calving period, calving to service interval, herd size, proportion of North American Holstein-Friesian genes, peak milk yield, semen fresh or frozen-thawed status, AI sire and a cow history variable to account for the correlation structure that may exist between performance records of cows present in both years of the study. Interactions of interest were tested but were non-significant. No significant association was observed between the category of AI operator and the likelihood of conception rate to first service (PREG1). The variation in PREG1 observed within the category of operator (CAI and DIY) was investigated using the Levene test for homogeneity of variance. There was no difference between the level of variation observed within CAI and DIY operators. There were significant differences in the likelihood of PREG1 between different AI sires. Amongst the 40 most commonly used AI sires, 3 sires had a lower likelihood of PREG1 (P < 0.05) when compared to the reference AI sire (sire with PREG1 similar to the mean of the group). There was a tendency for a reduced likelihood of PREG1 with the use of fresh semen compared to frozen-thawed semen (OR = 0.80, P = 0.067). Amongst the adjustment variables in the model, those significantly associated with the likelihood of PREG1 included the herd, calving period, calving to first service interval and peak milk yield. No significant difference in the likelihood of PREG1 was observed between AI and NAT.