Small Litters Research Articles

Maternal early overfeeding negatively impacts cardiac progenitor cells differentiation and cardiomyocyte maturation in the neonatal offspring.

Maternal obesity has been positively correlated with an increased cardiometabolic risk in the offspring throughout life, implying intergenerational transmission. However, little is known about the early life cardiac cell modifications that imply the onset of heart diseases later in life. This study analyzed cardiac progenitor cells and cardiomyocyte differentiation on day of birth in the offspring born to obese dams. The litter size reduction model was used to induce obesity in female Swiss mice. Both maternal groups, the Small Litter Dams (SLD-F1), which were overfed during lactation, and the Normal Litter Dams (NLD-F1), control group, were mated to healthy male mice. Their first generation offspring (SLD-F2 and NLD-F2, n=6 by group) were euthanized on birth. Mothers from SLD had increased body mass, Lee Index, fat deposits, hyperglycemia, and glucose intolerance, confirming the obese phenotype. The offspring born from SLD-F1 had also increased body mass, Lee Index, and fasting hyperglycemia. The heart of SLD-F2 showed decreased cardiac mass/body mass ratio, increased cardiac collagen deposits, and a greater number of undifferentiated cardiac c-kit+ and Sca-1+ progenitor cells, and increased NKX2.5+ cardiomyoblasts compared to control. In addition, SLD-F2 demonstrated immature cardiomyocytes. Obese dams negatively impact its offspring, leading to altered biometric and metabolic parameters, along with an immature heart already at birth, with extracellular matrix adverse remodeling, delayed cardiac progenitor cells differentiation and restrained cardiomyocyte maturation, which can be related with the development of cardiometabolic disease in the adulthood.

Divergent Importance and Geographic Patterns in Threats to Birds and Mammals in China

ABSTRACTAimWildlife populations are continuing to decrease worldwide. Understanding the ranking and distribution of drivers of species declines is crucial to enable targeted actions to counteract major threats. However, few studies have assessed the relative importance and geographic distribution of threats to biodiversity in China, even for high‐profile groups such as birds and mammals. Therefore, this study aims to rank and map the distribution of threat to birds and mammals in China, which could provide novel insight into biodiversity conservation in China.LocationChina.MethodsA database of different threats for 147 threatened bird species and 176 threatened terrestrial mammal species was obtained from China's Red List of Biodiversity published in 2021. We collated information on the distribution and threat categories for birds and mammals in China, aiming to classify, rank and map threats. We used Bray–Curtis dissimilarity index to examine the correlations of threats occurring simultaneously, and compared the distribution of habitat of threatened birds and mammals. In addition, we conducted threat ranking analyses of threatened birds and mammals between different orders and traits (body mass and clutch/litter sizes).ResultsThe results showed that the most common threats to birds were habitat loss, hunting, human disturbance, agriculture, pollution and logging, while the most common threats to mammals were hunting, agriculture, logging, habitat loss, human disturbance and livestock farming or ranching. These threats showed different geographic patterns, and some threats frequently co‐occur as threat syndromes. Forests were the primary habitat for most threatened species, and orders formed by larger species with small clutch or litter sizes were more likely to be threatened.Main ConclusionsWe highlight the most common threats and key areas for conservation. Furthermore, focusing on clusters of co‐occurring threats may be the most effective way to aid recovery of threatened species, and targeted actions are needed to counter ongoing population declines in many groups. These actions should not be limited to the protection of regions where species are at risk of multiple significant threats, but should also include the maintenance and restoration of native forests and strategic planning of afforestation through planted forests.

Abstract P351: Obesity in Early Life Leads to Endothelial and Erectile Dysfunction in Young Adult Rats.

Background: Erectile dysfunction (ED) is largely associated with obesity, however, the consequences of early life obesity for ED in young adulthood are unknown. We hypothesize that obesity induced by preweaning overfeeding impairs vascular and erectile function and affects blood pressure in young adult male rats (5-month-old). Methods: At postnatal day (PND) 1, Wistar rats were divided into a normal litter (NL, 5 female + 5 male pups/dam) or small litter (SL, 2 male + 1 female pup/dam) during lactation. After weaning, SL pups had increased body weight. Next, rats from both groups returned to normal size colonies (4-5 rats per cage) and were fed standard chow. At PND160, we evaluated body weight and fat pad deposition, mean arterial pressure (MAP) by tail-cuff, and pudendal artery (PA) and corpus cavernosum (CC) reactivity. Concentration-response curves to phenylephrine (PE) or acetylcholine (ACh) were performed in both preparations. In the CC, contraction and relaxation to electrical field stimulation (EFS) were obtained. Concentration-response curves were analyzed using non-linear regression analysis. RNA sequencing (RNAseq) analyses were performed in both PA and CC. Data were analyzed by Student’s t-test and presented as mean ± S.E.M. Statistical significance was set at p<0.05. Results: At PND160 no differences in body weight were observed in SL (594±14g) compared to NL (559±13g), however, there was an increase in fat deposition in SL (retroperitoneal fat: NL 7.47±0.69g vs SL 11.25±1.23g; perigonadal fat: NL 10.05±0.55g vs SL 13.24±1.16g). MAP was higher in SL (120.5±1.20 mmHg vs 114.9±0.58 NL). In the PA, ACh-induced relaxation was reduced in SL (Emax: 28±6%) vs NL (Emax: 68±5.5%), with no changes in the contraction to PE. In the CC, EFS-induced relaxation was significantly decreased in SL rats compared to NL rats (16 Hz: NL 3.06 ± 0.28% vs SL 2.39 ± 0.53%). RNAseq revealed that, in PA from SL rats, 289 and 224 genes were down and upregulated, respectively, while in the CC from SL rats, 115 genes were downregulated, and 110 genes were upregulated. Among them, hcn2 gene (which encodes HCN2, the hyperpolarization-activated cyclic nucleotide-gated potassium and sodium channel 2) was strongly downregulated in both PA and CC, and this may affect mechanotransduction. Conclusion: Our data shows that early-life obesity causes long-lasting vascular and cavernous damage that might be associated with endothelial and erectile dysfunction in young adulthood.

Swimming training prevents obesity installation and normalizes hypothalamic expressions of GLP1 and leptin receptors in adult offspring born in small litters.

Glucagon-like peptide-1 (GLP1) and leptin (Lep) are afferent signals that regulate energy metabolism. Lactational hypernutrition results in hyperphagia and adiposity in adult life, and these events can be prevented by exercise. We evaluated the effects of swimming training on hypothalamic (GLP1-R) and Lep receptor (Lep-R) gene expressions in lactational hypernutrition-induced obesity. On the 3rd postnatal day, the litter sizes of lactating dams were adjusted to small litters (SL; 3 pups/dams) or normal litters (NL; 9 pups/dams). After weaning (21 days), NL and SL male rats were randomly distributed to sedentary (Sed) and exercised (Exe) groups. Exercised mice swam (30 min/3 times/week) for 68 days. Food intake and body weight gain were registered. At 92 days, intraperitoneal glucose and insulin tolerance tests were performed and rats were euthanized at 93 days; adipose tissue depots were weighed, and blood counts and plasma biochemical analyses performed. Hypothalamus were isolated to evaluate Lep-R and GLP1-R gene expressions. Small litters sedentary rats presented increased body weight gain, adiposity, insulin sensibility and higher fasting values of glucose and triglycerides, besides higher hypothalamic gene expressions of Lep-R and GLP1-R, compared to NLSed animals. SLExe rats did not develop obesity or metabolic abnormalities and Lep-R and GLP1-R hypothalamic gene expressions were normalized. Lactational hypernutrition induces obesity and metabolic dysfunction in adult life, in association with higher hypothalamic expressions of the Lep-R and GLP1-R genes. Exercise prevented obesity and improved metabolic state in SL overnourished rats, and normalized their hypothalamic Lep-R and GLP1-R gene expressions.

Proper micro-environment alleviates mortality in laboratory mouse breeding induced by litter overlap and older dams

The ongoing worldwide effort to reduce animal numbers in research often omits the issue of pre-weaning mortality in mouse breeding. A conservative estimate of 20% mortality would mean approximately 1.1 M mice die annually in the EU before scientific use. We hypothesize that pre-weaning mortality in laboratory mouse breeding is associated with cage social and macro/micro-environment conditions. Here we count pups from 509 C57BL/6J litters daily for accurate detection of mortality, and monitor cage micro-environment for 172 C57BL/6J litters. Probability of pups to die increases with the increase in dam age, number and age of older pups in the cage (of overlapped/cohabitating litters), and in small (<6 pups) and large (>11 pups) focal litters. Higher temperatures (>23.6 °C) and nest scores (>3.75) compensate for some of the socially-associated risks for pup death. These findings can be implemented in strategies for reducing pre-weaning mouse mortality, a more welfare-friendly and sustainable approach for science.

Neonatal overfeeding promotes anxiety, impairs episodic-like memory, and disrupts transcriptional regulation of hippocampal steroidogenic enzymes

The objective of our study was to investigate the impact of neonatal overfeeding on cognitive functions and neurosteroidogenesis in male rats. Offspring were assigned to either small litters (SL; 4 pups/mother), resulting in increased milk intake and body weight gain, or normal litters (NL; 10 pups/mother). On postnatal day (PND) 21, half of the male rats were euthanized, while the remaining were kept under standard conditions (4 rats/cage) until PND70. At this stage, subjects underwent assessments for locomotor activity, anxiety levels via the elevated plus maze, and episodic-like memory (ELM) tests. By PND90, the rats were euthanized for brain dissection. Utilizing micropunch techniques, dentate gyrus (DG), CA1, and CA3 regions were extracted for analysis of mRNA expression and methylation patterns. At PND21, SL rats exhibited increased body and adipose tissue weights, alongside elevated cholesterol, glucose, and triglyceride levels compared to NL counterparts. By PND90, although metabolic disparities were no longer evident, SL rats demonstrated heightened anxiety-like behavior and diminished performance in ELM tests. Early life changes included a decreased expression of aromatase (P450arom) and 3α-HSD in CA1, with increased levels in CA3 and DG among SL rats. Additionally, PND90 rats from SL exhibited increased P450arom and decreased 5α-reductase 1 (5αR-1) expression in DG. Notably, some of these variations were correlated with changes in methylation patterns of their promoter regions. Our findings reveal that neonatal overfeeding exerts a long-term adverse effect on cognitive abilities and neurosteroidogenic pathways, underscoring the lasting impact of nutritional experiences during critical early postnatal development periods.

Teratogenic effects of voriconazole (anti-fungal drug) on Swiss albino mice

Antifungals are a class of drugs that target the treatment of invasive fungal infections. This includes polyenes, triazoles, and echinocadins. Among these, azoles are being extensively used nowadays. Triazoles have become standard for the azoles and have replaced amphotericin B as the first line of defence for fungal infections. With the increased cases of fungal infection, which affect a majority of the population at different stages and situations, one such section of the population is pregnant females. The rate and susceptibility of fungal infections are particularly higher in pregnant females, as the immunity of the mother is highly compromised. Systemic fungal infections like invasive aspergillosis, esophageal candidiasis, and candidemia are being treated with new age triazole antifungals like voriconazole. Prolonged and high concentrations of this drug are associated with various developmental anomalies. With this aim, teratogenic studies were performed on pregnant female mice during gestation and the weaning/lactation period to observe the effects of voriconazole at different dosages (8 mg/kg b.w., 10 mg/kg b.w., and 20 mg/kg b.w.). Pregnant dams were subjected to 20 mg/kg b.w. Voriconazole had a small litter size and a high number of resorptions. Craniofacial defects in the form of reduced ossification and widely open sutures, the presence of the 14th rib, asymmetry in the sternebrae, and the absence of ossified distal phalanges were some of the skeletal anomalies which were significant in the foetus and pups subjected to both 10 mg/kg b.w. and 20 mg/kg b.w. doses of voriconazole.

Enlarging interface reverses the dominance of fungi over bacteria in litter decomposition

Soil microorganisms are primary decomposers driving carbon and nutrient cycling in terrestrial ecosystems. One prevailing view is that fungi, rather than bacteria, play a predominant role in litter decomposition. However, the roles of bacteria and factors that restrict their activity during decomposition remain unclear. We hypothesized that the limiting activity of bacterial decomposers is associated with litter size beyond chemical quality. To address this gap, we conducted a 180-d decomposition microcosm experiment to investigate the effect of fragment size (large, 1–2 mm; middle, 0.18–0.28 mm; small, <0.07 mm) of oak and pine litters on bacterial or fungal decomposition. Bacterial and fungal decomposition were accelerated with fragment size decrease, suggesting that an interface effect existed between microbial decomposers and litter. Generally, the decomposition ability of bacteria was more sensitive to changes in fragment size compared to fungi. Fungi resulted in faster decomposition of large fragments than bacteria. For small oak litter fragments, bacteria showed faster decomposition than fungi, whereas the opposite was true for small pine litter. Therefore, the decomposition dominance of bacteria and fungi was regulated by fragment size and influenced by the chemical quality of litter, especially the lignin:N ratio. The contrasting decomposition dominances of bacteria versus fungi were likely attributed to filamentous fungi penetrating litter interiors and forming mycelial bridges between scattered litters. Bacteria resided on litter surfaces and even formed biofilms. Consistent with the findings of the microcosm experiment, the proportion of small fragments was greater in the fresh litter layer than in the decomposed layer in the field, and greater in the pine forest than in the oak forest, suggesting the fresh, large, and low-quality litter was preferentially fragmented by fungi. Consequently, the dominance of fungi and bacteria during litter decomposition in the conventional view should be revisited considering the litter size.

Factors contributing to stillbirth in young hyper-prolific sows in a tropical free-farrowing system.

The present study investigated factors associated with the incidence of stillbirth in young hyper-prolific sows within free farrowing systems in tropical environments. A total of 714 live-born and 54 stillborn piglets from 57 Landrace × Yorkshire sows, with an average parity of 2.7 ± 1.0 (range: 1 - 4), were comprehensively investigated. Reproductive variables of the sows, including gestation length, farrowing duration, the total number of piglets born per litter, and the birth order and status of each piglet, were recorded. Differences in the physiological characteristics of live-born and stillborn piglets, such as birth interval, cumulative birth interval, body weight at birth, crown-rump length, body mass index (BMI), ponderal index (PI), meconium staining score, and the percentage of piglets with a broken umbilical cord, were analysed. Piglets were divided into four groups based on the quartiles of birth order (Q1-Q4). On average, the duration of farrowing was 173.3 ± 85.9 min, and the total number of piglets born and number of piglets born alive-per litter were 14.1 ± 3.8 and 12.5 ± 3.5, respectively. The incidence of stillbirth was 6.7% (54/801 piglets). The higher percentages of stillbirths were detected in sows with large litter sizes (≥17 piglets, 10.9%) compared to those with small (≤13 piglets, 6.1%) and moderate (14 - 16 piglets, 2.8%) litter sizes (p < .001). The incidences of stillbirth in Q3 and Q4 of the litters were higher than in Q1 and Q2 (p < .001). Compared to live-born piglets, stillborn piglets had higher cumulative birth interval (103.0 ± 3.71 vs. 142.4 ± 9.35 min, p < .001), BMI (17.1 ± 0.15 vs. 18.4 ± 0.39 kg/m2, p = .002), PI (63.7 ± 0.59 vs. 70.8 ± 1.59 kg/m3, p < .001), meconium staining scores (1.78 ± 0.04 vs. 2.04 ± 0.10, p = .021), and the percentage of piglets born with a ruptured umbilical cord (45.2% vs. 66.0%, p = .004). An increase in the incidence of stillbirth was detected at 60, 120, 150, 180, and ≥ 210 min after the first piglet was born, compared to those born within the first 30 min of farrowing (p < .05). In conclusion, the study found that stillbirths in young, hyper-prolific sows were linked to several factors: large litter sizes (≥17 piglets per litter), prolonged cumulative birth intervals (142.4 min), elevated BMI of 18.4 kg/m2, high PI values of 70.8 kg/m3, increased meconium staining scores, and a higher occurrence of ruptured umbilical cords. To reduce the risk of stillbirth, particularly among piglets with high body indices born later in the birthing process, it is recommended to enhance farrowing supervision for young sows, starting at a cumulative birth interval of 60 min.

Effects of extrinsic and intrinsic factors on parturition and reproductive output in wolverines

AbstractOne of the selective advantages of delayed implantation in carnivores is the flexibility to decouple the time between mating and parturition, allowing both to occur when conditions are most favorable. Terrestrial carnivores with delayed implantation have evolved reduced maternal energy expenditure through shorter gestation length, smaller neonates, and smaller litters, with a possible linkage between maternal body condition and time of birth or litter size. Using data on wolverine (Gulo gulo) females and cubs from management removals covering the entire latitudinal gradient of the Scandinavian population in 2001‐2022, I assessed the effect of extrinsic and intrinsic factors on variation in parturition date and litter size. Timing of parturition varied over 2 months, where 90% of the litters were born between 5 February and 11 March, with a birth peak on 23 February. Females living in winter grazing pastures of semi‐domestic reindeer (Rangifer tarandus) gave birth earlier than those outside, and along an elevation gradient parturition date was delayed at higher altitudes. I did not find evidence of an effect of latitude on parturition date. Furthermore, older females had greater odds than younger females of having litters with 3 cubs rather than 1 cub. To minimize the risk of harvesting lactating females, management regulations should implement harvest seasons that extend no longer than the end of January.

Role of RIPK3 in lipid metabolism and postnatal overfeeding-induced metabolic disorders in mice

Postnatal overfeeding can increase the long-term risk of metabolic disorders, such as obesity, but the underlying mechanisms remain unclear and treatment approaches are limited. Receptor-interacting protein kinase 3 (RIPK3) is associated with several metabolic diseases. We investigated the effects of RIPK3 on neonatal overfeeding-related metabolic disorders. On postnatal day 3, litter sizes were adjusted to 9-10 (normal litters, NL) or 2-3 (small litters, SL) mice per dam to mimic postnatal overfeeding. After weaning, NL and SL mouse were fed normal diet. We generated an adeno-associated virus (AAV) carrying short hairpin RNA (shRNA) against Ripk3 and an empty vector as a control. The NL and SL groups were treated intravenously with 1×1012 vector genome of AAV vectors at week 6. The SL group showed a higher body weight than the NL group from week 3 of age through adulthood. At weeks 6 and 13, the SL group exhibited impaired glucose and insulin tolerance, RIPK3 up-regulation, and lipid accumulation in liver and adipose tissues. In the SL group, the genes involved in lipid synthesis and lipolysis were increased, whereas fatty acid β-oxidation-related genes were weakened in adipose tissue and liver. At week 13, AAV-shRNA-Ripk3 ameliorated adipose tissue hypertrophy, hepatic steatosis, insulin resistance, and dysregulated lipid metabolism in the adipose tissue and liver of SL mice. These findings support a novel mechanism underlying the pathogenesis of postnatal overfeeding-related metabolic disorders and suggest potential therapeutic targets.

Litter in French urban areas-Part 2: transport dynamic and fluxes in stormwater.

Urban areas constitute a major hotspot of litter, including plastic litter, that stormwater can wash off towards waterways. However, few studies quantified and characterized litter densities in urban areas and fluxes transported by stormwater networks. Moreover, little information is available on litter transport dynamics in stormwater, and on the factors driving this transport. This study aims at characterizing and quantifying litter amounts transported by stormwater of two nested French urban catchments (total surface area of 105ha). Litter densities relative to land uses and rain events were investigated in the same catchments as in a compagnon paper (Ledieu et al., 2024). The present study explores the impact of rain events on the transport of urban litter in stormwater. Litter collection and characterization combined with a capture/recapture experiment using tagged litter placed in stormwater inlets show total litter fluxes of 29kg/year, in which 14kg/year are plastics, exported at the stormwater outlet. These fluxes confirm that stormwater runoff is a considerable pathway from urban surfaces to waterways, especially regarding small plastic litter (< 2.5cm). Item transport dynamic is however not linear and only 0.3% of the urban litter appear remobilized. Litter transport dynamics depends on several factors (urban litter densities, hydrometeorological parameters, item composition and morphologies, and stormwater management systems) that should be considered in global models.

Effects of a Functional Food Made with Salvia hispanica L. (Chia Seed), Amaranthus hypochondriacus L. (Amaranth), and an Ethanolic Extract of Curcuma longa L. (Curcumin) in a Rat Model of Childhood Obesity.

Obesity is a global health problem and is increasing in prevalence in most countries. Although obesity affects all age groups, children are the most vulnerable sector. Functional foods are novel formulated foods containing substances (i.e., nutrients, phytochemicals, probiotics, etc.) that have potential health-enhancing or disease-preventing value. The research objective was to study the possible beneficial effects of providing a functional food made with amaranth flour, chia seed, and curcumin extract on the metabolism and behavior of a rat model of childhood obesity. Male Wistar rat pups from two litters of different sizes, a normal litter (NL) (10 pups) and a small litter (SL) (4 pups), were used. After weaning, the rats were fed a hypercaloric diet (HD) or an HD supplemented with the functional food mixture. Body weight and energy intake were measured for seven weeks, and locomotor activity, learning, and memory tests were also performed. At the end of the experiment, glucose and lipid metabolism parameters were determined. The results showed that in this model of obesity produced by early overfeeding and the consumption of a hypercaloric diet, anxiety-like behaviors and metabolic alterations occurred in the rat offspring; however, the provision of the functional food failed to reduce or prevent these alterations, and an exacerbation was even observed in some metabolic indicators. Interestingly, in the NL rats, the provision of the functional food produced some of the expected improvements in health, such as significant decreases in body weight gain and liver cholesterol and non-significant decreases in adipose tissue and leptin and insulin serum levels.

Unraveling the Influence of Litter Size, Maternal Care, Exercise, and Aging on Neurobehavioral Plasticity and Dentate Gyrus Microglia Dynamics in Male Rats.

This study explores the multifaceted influence of litter size, maternal care, exercise, and aging on rats' neurobehavioral plasticity and dentate gyrus microglia dynamics. Body weight evolution revealed a progressive increase until maturity, followed by a decline during aging, with larger litters exhibiting lower weights initially. Notably, exercised rats from smaller litters displayed higher body weights during the mature and aged stages. The dentate gyrus volumes showed no significant differences among groups, except for aged sedentary rats from smaller litters, which exhibited a reduction. Maternal care varied significantly based on litter size, with large litter dams showing lower frequencies of caregiving behaviors. Behavioral assays highlighted the detrimental impact of a sedentary lifestyle and reduced maternal care/large litters on spatial memory, mitigated by exercise in aged rats from smaller litters. The microglial dynamics in the layers of dentate gyrus revealed age-related changes modulated by litter size and exercise. Exercise interventions mitigated microgliosis associated with aging, particularly in aged rats. These findings underscore the complex interplay between early-life experiences, exercise, microglial dynamics, and neurobehavioral outcomes during aging.

Pre-Weaning Overfeeding Promotes Prepubertal Obesity and Evokes Sexual Dysfunction in Young Adult Rats

Obesity in early life can contribute to several health issues in adulthood, including diabetes, high blood pressure, and high cholesterol, and these conditions are associated with sexual dysfunction. Here, we hypothesized that pre-weaning overfeeding can have long lasting effects on body fat distribution and erectile function that will be observed in young adult males. On postnatal day (PND 1), Wistar rats were separated into two groups: normal litter (NL) with 10 pups per dam, or small litter (SL) with 3 pups per dam. Male rats (n = 8-10 per group) were then assessed at two different time points: during the prepubertal stage (PND 40) and in adulthood (PND 120). Erectile function was assessed only after sexual maturation (i.e., PND 120). Body weight, retroperitoneal and perigonadal adipose tissue (fat pad weight/100g of the body) were evaluated. Following euthanasia at PND 120, the corpus cavernosum (CC) was removed to perform functional studies using a strip myograph. Contractile and relaxation responses were evaluated by electrical field stimulation (EFS) and concentration-response curves (CRC) to phenylephrine [Phe, 1nM-30μM, millinewton (mN)] or acetylcholine (Ach 1nM-30μM, % relaxation) were performed. At the prepubertal stage, SL rats had higher body weight (NL 149±3 vs. SL 186±5, g, p&lt;0.05), and increased retroperitoneal (NL 0.17±0.01 vs. SL 0.32±0.03, g/100g, p&lt;0.05) and perigonadal (NL 0.38± 0.02 vs. SL 0.45±0.03, g/100g, p&lt;0.05) adipose tissue. At PND 120, SL group presented increased body weight (NL 534.2.7±13 vs. SL 631.6±10, g, p&lt;0.05), retroperitoneal (NL 1.31±0.11 vs. SL 1.82±0.14, g/100g, p&lt;0.05) and perigonadal (NL 1.74±0.10 vs. SL 2.18±0.15, g/100g, p&lt;0.05) adipose tissue when compared with NL group. The CC of SL rats at PND 120 had increased contraction induced by EFS for all frequencies (1 Hz: NL 0.5 ± 0.2 mN vs. SL 0.9 ± 0.2 mN; 4 Hz: NL 1.2 ± 0.3 mN vs. SL 1.8 ± 0.2 mN; 16 Hz: NL 1.9 ± 0.4 mN vs. SL 3 ± 0.4 mN), whereas the relaxation was decreased in SL (1 Hz: NL 0.77 ± 0.18% vs. SL 0.27 ± 0.09%; 4 Hz: NL 2.48 ± 0.26% vs. SL 1.36 ± 0.41%; 16 Hz: NL 3.06 ± 0.28% vs. SL 2.39 ± 0.53%). CRC showed increased contractile response to Phe (Emax NL 2.3±0.3 vs. SL 3.8± 0.6, mN, p=0.05) and reduced potency of ACh (pEC50 NL 6.4±0.6 vs. SL 4.9±0.7, mN, p=0.1) in the CC of SL. Incubation with indomethacin (10μM) abolished the differences in the contractile response induced by EFS or Phe between SL and NL, suggesting a heightened inflammatory response. Moreover, the CC of SL rats presented increased expression of Phospho-p44/42 MAPK (NL 0.9±0.25 vs. SL 1.3±0.11, p=0.2). Finally, proteome profiler cytokine array of serum samples from SL animals showed increased circulating levels of cytokines and chemokines associated with obesity, aging, and vascular dysfunction. Together, these data suggest that early prepubertal obesity has long-lasting negative implications on sexual function in young adulthood. National Institutes of Health (NIH); American Heart Association (AHA); Fulbright Program. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Hypobaric hypoxia causes low fecundity in zebrafish parents and impairment of skeletal development in zebrafish embryos and rat offspring

Hypobaric Hypoxia (HH) negatively affects the cardiovascular and respiratory systems as well as gonadal development and the therefore next generation. This study investigated the effects of HH on zebrafish and SD rats, by exposing them to a low-pressure environment at 6000 m elevation for 30 days to simulate high-altitude conditions. It was indicated that parental zebrafish reared amh under HH had increased embryo mortality, reduced hatchability, and abnormal cartilage development in the offspring. Furthermore, the HH-exposed SD rats had fewer reproductive cells and smaller litters. Moreover, the transcriptome analysis revealed the down-regulation of steroid hormone biosynthesis pathways. The expression of the gonad-associated genes (amh, pde8a, man2a2 and lhcgr), as well as the gonad and cartilage-related gene bmpr1a, were also down-regulated. In addition, Western blot analysis validated reduced bmpr1a protein expression in the ovaries of HH-treated rats. In summary, these data indicate the negative impact of HH on reproductive organs and offspring development, emphasizing the need for further research and precautions to protect future generations' health.

Method of Inoculation Influences the Survival of Salmonella enterica on Retail and Orchard Peaches

Challenge studies associated with fruits and vegetables generally utilize wet bacterial inoculation methods. However, a recent salmonellosis outbreak in the U.S. was linked to peaches plausibly contaminated via fugitive dust from a nearby animal operation. This outbreak has highlighted the need for a suitable inert carrier which can be used for the dry transfer of Salmonella enterica to produce. The purpose of this study was 1) to examine the population stability of S. enterica and its surrogate, Enterococcus faecium, in different dry matrices during extended storage to identify suitable carriers and 2) to evaluate the survival of S. enterica on peaches based on the mode of contamination (i.e., wet vs. dry). S. enterica and E. faecium were cultivated on tryptic soy agar (TSA) and inoculated into corn-cob small animal litter, sand, or silica at 10–11 log CFU/g. Matrices were mixed by hand and stored at 25°C and 33% relative humidity for up to 120 d. S. enterica remained relatively stable in the silica and litter, with no significant decrease in population after 14 and 28 d, respectively. E. faecium significantly reduced in all matrices, with the greatest reduction observed in silica (2.86 log CFU/g after 120 d). Additional carriers would need to be assessed for E. faecium which could maintain its population stability. Silica was ultimately selected for the dry carrier of S. enterica. Peaches available at retail or from orchards were inoculated with S. enterica using the silica carrier or by spot or dip inoculation methods at 5 log CFU/peach and stored at 5°C and 80% relative humidity for up to 28 d. The population of S. enterica significantly reduced on all peaches except for the dry inoculated orchard peaches, where the population remained stable (4.62 ± 0.35 log CFU/peach after 28 d). Results from this study determined that the mode of contamination influences the survival of S. enterica on peaches and that dry inoculation methods should be considered for produce in some instances.

Prepuberty is a window period for curcumin to prevent obesity in postnatal overfed rats.

Overnutrition in early life increases the risk of obesity and metabolic diseases. We investigated the effects and the window period of a curcumin (CUR) diet on postnatal overfed rats. Male rats aged 3 days were randomly divided into normal litters (NL, 10 pups/litter) and small litters (SL, 3 pups/litter). After weaning (Week 3, W3), NL rats were fed a normal diet (NL) and SL rats were fed a normal diet (SL) or 2% CUR diet from weaning (W3) (SL-CURW13), beginning of puberty (W6) (SL-CURW16), or end of puberty (W8) (SL-CURW18) for 10 weeks. Body weight, glucose intolerance and hyperlipidemia in the SL rats were higher than in the NL rats, especially after puberty. After the CUR intervention, SL-CURW13 and SL-CURW16 rats showed lower body weight gain, adipose tissue weight and mRNA level of C/EBPα in SAT, along with higher mRNA levels of β-catenin. There was no difference between SL and SL-CURW18 rats. Glucose tolerance, serum lipids and hepatic lipids recovered to normal in the SL-CURW13 rats, but only partially in the SL-CURW16 and SL-CURW18 rats. Prepuberty is a window period for CUR intervention to improve programmed outcomes in postnatal overfed rats. Overnutrition during the first 1000 days of life has persistent negative effects on metabolism. Strategies should be taken to prevent overnutrition in early life to reduce the risk of obesity and metabolic disease in later life. A small-litter rat model was utilized to simulate early-life overnutrition in humans. We investigated the different effects and critical period for curcumin intervention on postnatal overfed rats. Dietary curcumin intervention before puberty could effectively transform nutritional programming to reduce obesity and metabolic disorders caused by early-life overnutrition, and an earlier intervention might predict a better outcome.

Marine Macro- and Micro Plastic Litter on Beach Sediment of Northern Peninsular Malaysia

This paper investigates the spatial distribution of small plastic litter on the beach of Kuala Perlis and Pulau Langkawi in the northern region of Peninsular Malaysia. The objectives are to ascertain the categories of macro marine litter and macroplastic types, the amount of microplastic in the sediment layer, and the relationship between macroplastic and microplastic. Macro marine litter was collected in 100-meter transects at six different locations. Sediment samples for microplastic identification were collected using a quadrat measuring 0.5 m × 0.5 m with a depth of 0.05 m. Plastic accounts up most of the macro marine litter collected (73.8%), followed by glass (12%), fabric (7.8%), rubber (4.4%), wood (2%), and metal (0.07%). Between 2018 and 2020, the overall weight of macroplastic (&gt;5 mm) litter and the amount of microplastic (&lt;5 mm) litter on northern beaches were 80.371 g/m2 and 11.094 g/m3, respectively. In this investigation, macroplastic collected on the beach surface ranged from 0.02 g to 14.09 g/m2, while microplastic in the beach sediment ranged from 0 to 1.192 g/m3. The packaging category seems to have the highest percentage of collected macroplastic. At the 95% confidence level, the calculated R2 of 0.7444 indicates a substantial association between macroplastic and microplastic. The linear regression equation is y = 0.1927x + 0.0226, with y representing microplastic (g/m3) and x being macroplastic (g/m2). This strong link demonstrates that the presence of microplastic in sediment is strongly related to the abundance of macroplastic on the beach. This finding provides a good approximation of actual microplastic occurrence to macroplastic abundance, which will be useful in environmental evaluation and management approaches.

EFECTO DEL TAMAÑO DE CAMADA EN PRIMER PARTO Y SEGUNDO PARTO SOBRE LA PRODUCTIVIDAD ACUMULADA DE LAS CERDAS, EN UNA GRANJA COMERCIAL DE YUCATÁN, MÉXICO

&lt;p&gt;&lt;strong&gt;Background.&lt;/strong&gt; Litter size reduction at second farrowing (RSP) affects cumulative productivity per productive life of sows. &lt;strong&gt;Objective.&lt;/strong&gt; To compare groups of sows according to their classification by number of piglets born alive (LNV) at first farrowing and reduction or increase of LNV at second farrowing on the number of farrowings at culling (NPD), cumulative LNV and weaned per productive life of sows in a commercial farm in the eastern zone of Yucatan, Mexico. &lt;strong&gt;Methodology&lt;/strong&gt;. Data from 404 culled sows were used. Six groups of sows were established: low number of LNV at first farrowing with RSP (B-RSP), low with increased number of LNV at second farrowing (B-ISP), medium with RSP (M-RSP), medium with ISP (M-ISP), high with RSP (A-RSP) and high with ISP (A-ISP). The response variables were NPD, cumulative piglets born alive during the productive life of the sows (LNVP) and cumulative piglets weaned during the productive life of the sows (LDVP). &lt;strong&gt;Results.&lt;/strong&gt; No difference was found between the different sow groups for NPD and LDVP (P&amp;gt;0.05). The lowest number of LNVP was obtained in sows of groups B-RSP and B-ISP (P&amp;lt;0.05). &lt;strong&gt;Conclusion.&lt;/strong&gt; Under the conditions of this study, NPD and LDVP of sows during their stay on the farm were not affected by RSP or ISP. LNVP was not affected by reduction or increase of piglets at second farrowing in sows with small litters at first farrowing.&lt;/p&gt;