Juvenile Population Research Articles

Dynamics analysis of Filippov pest control model with two economic thresholds

Understanding the stages of the pest life cycle, from the juvenile class to the adult class, is crucial for developing effective pest control strategies. Targeted interventions can be tailored to each life stage, maximizing control efficiency and reducing the excessive use of pesticides; therefore, they help minimize damage to crops. With this motivation, we present a new strategy that uses the Filippov framework to describe the two stages of the pest life cycle, from the juvenile class to the adult class, with two economic thresholds. These thresholds serve as a vital signal for the timely implementation of resistance strategies. The first threshold measure is dependent on the density of juvenile pests allowed, while the second threshold is based on the density of allowed adult pests. This model assists pest control by concurrently managing both juvenile and adult populations, effectively keeping them below dangerous thresholds. By employing a dual approach to population regulation, the system ensures a comprehensive strategy for pest management. The model's dynamic behaviours, existence, and stability of various equilibria are addressed both analytically and numerically. Furthermore, we investigate sliding segment regions to determine the timing of control measures for both juvenile and adult pest populations. Additionally, we discuss the dynamics of the sliding mode, covering both local and global sliding bifurcations. The results indicate that the utilization of two economic thresholds in pest management is beneficial, as they can help prevent pest outbreaks by maintaining the density of juvenile and adult pests at desired levels.

Two decades of body length measurements of larval and juvenile fish populations in English rivers

Long-term datasets provide context and understanding of complex ecological processes, including temporal variations in species diversity and ecosystem dynamics. This dataset is comprised of body length measurements (mm) of more than 380,000 larval or juvenile fish of 30 species from five English river catchments collected almost monthly over two decades. Such information can be used to determine growth rates, future recruitment success, population structure and compliance with monitoring protocols and conservation objectives. The dataset provides a baseline for analysing the impacts of anthropogenic disturbances such as climate change, pollution and habitat degradation, and, given that many fish populations are size structured with a positive relationship between fish body length and various biological attributes such as swimming ability, survival and fecundity, it will be invaluable for investigating natural and human- induced disturbances.

Increased use of mud bottom by juvenile American Lobsters (Homarus americanus) in Maces Bay and Seal Cove, Bay of Fundy, after 3 decades of population increases and predator declines

In the Bay of Fundy, American lobster (Homarus americanus) abundance has soared since the early 1990s, and predators have declined, either of which could have caused juvenile lobster populations in preferred hard-bottom habitat to expand onto less-protective mud bottom. To investigate whether juvenile lobsters have increased use of mud bottom, we used SCUBA surveys (1989-2021) in Maces Bay and Seal Cove, in the Bay of Fundy. Whereas the 1990s surveys found no juveniles on mud at either site (though they were present on hard bottom), in subsequent decades, juveniles inhabited mud burrows at densities of 0.00039 m-2 to 0.0081 m-2. In Maces Bay, mud occupancy occurred after juvenile density increases on hard bottom, but evidence was mixed as to whether increased competition within hard-bottom habitat drove this change. Concurrent cod, haddock, hake, and wolffish declines suggest reduced predation also increased occupancy and survival on mud. Although it supports low juvenile densities, mud habitat may contribute to recruitment given its prevalence, particularly as warming seas allow lobster recruitment into cooler, deeper water over mud bottom.

Population-based prevalence of self-reported pediatric diabetes and screening for undiagnosed type 2 diabetes in Chinese children in years 2017–2019, a cross-sectional study

The worldwide geographical and temporal variation in the prevalence of diabetes represents a challenge, but also an opportunity for gaining etiological insights. Encompassing the bulk of East Asians, a large and distinct proportion of the world population, China can be a source of valuable epidemiological insights for diabetes, especially in early life, when pathophysiology begins. We carried out a nationwide, epidemiological survey of Prevalence and Risk of Obesity and Diabetes in Youth (PRODY) in China, from 2017 to 2019, to estimate the population-based prevalence of diagnosed pediatric diabetes and screen for undiagnosed pediatric type 2 diabetes (T2D). PRODY was a nation-wide, school population-based, cross-sectional, multicenter survey by questionnaire, fasting urine glucose test and simple oral glucose tolerance test (s-OGTT), among a total number of 193,801 general-population children and adolescents (covered a pediatric population of more than 96.8 million), aged 3-18, from twelve provinces across China. The prevalence of the self-reported pediatric diabetes, the proportion of subtypes, the crude prevalence of undiagnosed T2D and prediabetes in general juvenile population and the main risk factors of type 1 (T1D) and type 2 (T2D) diabetes had been analyzed in the study. The prevalence of all self-reported pediatric diabetes was estimated at 0.62/1000 (95% CI: 0.51-0.74), with T1D at 0.44/1000 (95% CI: 0.35-0.54) and T2D at 0.18/1000 (95% CI: 0.13-0.25). For undiagnosed T2D, the crude prevalence was almost ten-fold higher, at 1.59/1000, with an estimated extra 28.45/1000 of undiagnosed impaired glucose tolerance (IGT) and 53.74/1000 of undiagnosed impaired fasting glucose (IFG) by s-OGTT screening. Maternal diabetes history is the major risk factors for all subtypes of pediatric diabetes in China. The PRODY study provides the first population-based estimate of the prevalence of pediatric diabetes China and reveals a magnitude of the problem of undiagnosed pediatric T2D. We propose a practical screening strategy by s-OGTT to address this serious gap. The National Key Research and Development Programme of China, Key R&D Program of Zhejiang, the National Natural Science Foundation of China and the Zhejiang Provincial Key Disciplines of Medicine, Key R&D Program Projects in Zhejiang Province.

Prevalence and Distribution of Rice Root Knot Nematode in Rice Nurseries in Chitwan and Lamjung Districts of Nepal

To determine the natural infection of the rice root-knot nematode (Meloidogyne graminicola Golden & Brichfield) in rice nurseries, a survey was carried out in Chitwan and Lamjung in June and July of 2022. Rice nurseries were randomly selected based on geographical location, agro-ecological region, land type, cropping practice, and soil type. Forty rice nurseries were surveyed i.e. twenty from each district and 100 seedlings from each nursery as the sample for the study using the simple random method of sampling were evaluated. Field survey revealed that M. graminicola was widely distributed in most rice growing areas of Chitwan and Lamjung districts. Most of the rice nurseries in Lamjung district were found to be infested with M. graminicola as compared to that of the Chitwan district. Disease severity was reported up to 23.26% in Lamjung and 20.2% in Chitwan district. Additionally, the study showed that dry bed conditions were more likely to be affected by rice root-knot disease than wet bed conditions. The majority of farmers planted seedlings on upland (dry) soil, where second-stage juvenile (J2) populations and rice root-knot disease were more common. Most farmers (87.5%) have limited knowledge about rice root knot nematodes and their control methods. This suggested a significant loss in rice output and a high danger of nematode multiplication. This information will provide knowledge about the prevalence of nematode and enabling rice growers in this region to design and implement an appropriate control strategy for managing M. graminicola.

Exploring the bio-efficacy of biocontrol agents in mitigating <i>Meloidogyne incognita</i> menace in carrot cultivation

The nematicidal efficacy of liquid formulation of Pochonia chlamydosporia, Bacillus subtilis, Purpureocillium lilacinum, Trichoderma viride and vermiculite formulation of Rhizophagus intraradices were challenged against Meloidogyne incognita under glasshouse conditions. The in vivo experiment were piloted to test the potential of these biological agents by soil drenching of liquid formulation @ 1 ml/ pot or soil application of vermiculite formulation @ 1g/pot/dose. Their effect was compared with the granular application of Carbofuran @ 1g/pot/dose. All the liquid bioformulations investigated were capable of enhancing plant growth and lowering the pathogenicity and parasitic success of M. incognita in carrots. The soil drenching of P. chlamydosporia caused a significant reduction of galls in the root (51%), nematode population in the root (43.6%), egg mass in the root (65.3%) and infective juvenile population in soil (51.8%) over other treatments and Carbofuran.

Impact of Socio-Demographic Factors on Quality of Life and Coping Strategies of Children with Different Disabilities.

Background and Objectives: Children with disabilities face unique challenges that can affect their well-being and quality of life (QOL). This study aimed to assess the QOL and coping strategies adopted by children with disabilities and explore how socio-demographic factors influence QOL and coping strategies. Materials and Methods: This cross-sectional study, which was conducted in Saudi Arabia with children aged 6 to 18 years, used a stratified random sample to ensure representation from a variety of demographic groups. Short Form-12 (SF-12) was used to assess the QOL in the sample population. The Brief COPE Inventory was used to examine coping strategies among the children. One-way analysis of variance was applied to examine differences in the QOL, coping strategies scores, and demographic variables. Multiple regression analyses were performed to examine the role of demographic variables in predicting QOL and p value was considered statistical significance at p < 0.05. Results: The results of the study clearly revealed significant differences between the mean scores of QOL for gender, age, and type of disability, duration of disability, education qualification, family status, family occupation, and housing status. Female participants showed better QOL in physical functioning than their male counterparts. Children with intellectual disability reported better QOL in general health, vitality, social functioning, and mental health. Participants with seven to eight years of disability reported higher scores in physical functioning, vitality, and mental health. Children whose parents were working in private agencies and living in rented houses scored higher on the general health aspects of quality of life. The findings also revealed that the duration of the disability was a significant predictor of the QOL. The mean scores of different dimensions of coping strategies clearly revealed that male participants used dysfunctional coping (p < 0.01), as compared to problem-focused and emotional-focused coping while female children relied more on emotional-focused coping. Emotion-focused coping was significantly higher in participants with visual (p < 0.01), learning (p < 0.01), and intellectual disabilities (p < 0.01). Dysfunctional coping scores were higher among children with auditory disabilities (p < 0.01) and multiple disabilities (p < 0.01). Conclusions: This study highlights the significance of demographic factors in understanding and improving the well-being of a diverse population of disabled juveniles. It offers valuable insights into the subtle factors affecting quality of life. Future interventions and policies can leverage these findings to enhance the quality of life of individuals with disabilities and to foster a more supportive and inclusive approach.

Percutaneous Epiphysiodesis Using Transphyseal Screws in Management of Coronal Plane Knee Deformities. A Prospective Case Series

Abstract Background Although many studies reported the efficacy of using percutaneous epiphsiodesis using transphyseal screws (PETS) in correction of coronal plane knee deformities, a lot of them refrained from using this technique because of lack of objective evidence of its reversibility. Methods Twenty-three patient aged from 8 years to 13 years old (40 lower limbs) with coronal plane knee deformity were enrolled into this prospective case series from September 2019 to June 2023. Rate of correction of Mechanical axis deviation MAD, mechanical lateral distal femoral angle mLDFA and medial proximal tibial angle MPTA were measured to prove PETS efficacy. Lower limb length, mLDFA, MPTA were recorded preoperatively and 6 months after screw removal in addition to CT scan of the treated physis to investigate physis behavior and reversibility of the technique. Results The mean MAD correction rate was 3.3 mm/month and 1.78 mm/month for genu valgum and genu varum patients respectively. mLDFA mean correction rate was 1.07 degree/month for genu valgum patients while MPTA mean correction rate was 0.81 degree/month for genu varum patient. No physeal bony bars could be detected 6 months after screw removal for all patients. Conclusion PETS is a highly effective method of hemiepiphysiodesis with rate of correction faster than the other methods of epiphysiodesis. Moreover, it is reliable, reproducible, easy, cheap, more cosmetic, safe and completely reversible when used in juvenile and early adolescent pediatric population

Assessment of the effects of cannabidiol and a CBD-rich hemp extract in Caenorhabditis elegans.

Consumer use of cannabidiol (CBD) is growing, but there are still data gaps regarding its possible adverse effects on reproduction and development. Multiple pathways and signaling cascades involved in organismal development and neuronal function, including endocannabinoid synthesis and signaling systems, are well conserved across phyla, suggesting that Caenorhabditis elegans can model the in vivo effects of exogenous cannabinoids. The effects in C. elegans on oxidative stress response (OxStrR), developmental timing, juvenile and adult spontaneous locomotor activity, reproductive output, and organismal CBD concentrations were assessed after exposure to purified CBD or a hemp extract suspended in 0.5% sesame oil emulsions. In C. elegans, this emulsion vehicle is equivalent to a high-fat diet (HFD). As in mammals, HFD was associated with oxidative-stress-related gene expression in C. elegans adults. CBD reduced HFD-induced OxStrR in transgenic adults and counteracted the hypoactivity observed in HFD-exposed wild-type adults. In C. elegans exposed to CBD from the onset of feeding, delays in later milestone acquisition were irreversible, while later juvenile locomotor activity effects were reversible after the removal of CBD exposure. CBD-induced reductions in mean juvenile population body size were cumulative when chronic exposures were initiated at parental reproductive maturity. Purified CBD was slightly more toxic than matched concentrations of CBD in hemp extract for all tested endpoints, and both were more toxic to juveniles than to adults. Dosimetry indicated that all adverse effect levels observed in C. elegans far exceeded recommended CBD dosages for humans.

Juvenile fatalities in law enforcement encounters

The use of deadly force by police is not typically associated with juveniles. However, a small percentage of cases do result in their deaths. Utilizing nationwide databases of fatalities involving law enforcement, 224 juvenile deaths were examined over a ten-year period. The majority of deaths were male and minorities. Most cases involved a weapon or the appearance of a weapon, with more than half of the youths having a firearm at the time of their death. Cases were mixed with respect to the suspect's “ flight status,” as many youths were not fleeing at the time of the incident. The circumstances of the deaths were examined for the neighborhood characteristics, such as educational attainment, youth poverty, juvenile population, and racial homogeneity of the area, as well as the situational factors involved at the time of the incident. The most predictive variable in all models was the percentage of Whites only population of the area. Analyses of these deaths shed light on the interactions police have with juveniles. Policy recommendations are included to reduce hostile police and juvenile interactions.

Etiological diagnosis of prostatitis: current methods and ethical evaluation

The incidence of acute and chronic bacterial prostatitis in the juvenile and adult population is steadily increasing. This phenomenon is related to changing sexual habits. The clinical diagnosis of acute prostatitis is quite simple, both because of the characteristic symptomatology (fever with chills, sacral rachialgia, perineal pain) and the semeiological data of the rectal exploration. Prostate ultrasound may finally help to settle a doubt.

Low predator and conspecific density lead to larger juveniles

Predation is a key size-selective mechanism structuring juvenile fish populations, given typically greater susceptibility of small juveniles in a population to predation compared to larger individuals. We tested the hypothesis that greater predator abundance selectively removes the smallest age 0 Atlantic cod (Gadus morhua) in nearshore habitat, truncating their size distribution in nursery habitats. We tested this hypothesis using fifteen years of historical data on nearshore fish abundance in Newman Sound, Newfoundland. Using skewness to estimate size-frequency distribution asymmetry, our analyses showed smaller age 0 cod were least prevalent under low predator and low conspecific densities. In contrast, high predator abundances corresponded to weak, size-selective removal of the smallest juveniles. Age 0 cod reached the largest sizes under lower predator and conspecific densities. Our analyses link size of individual juvenile fish in the wild with their survival, where predator abundance modulates the advantages gained by attaining larger size.

Transphyseal Hemiepiphysiodesis: Is it Truly Reversible?

Although numerous studies reported the efficacy of percutaneous epiphysiodesis using transphyseal screws (PETS) in correcting angular knee deformities, many surgeons refrained from using it in younger children because of a lack of objective evidence of reversibility. Our hypothesis is that PETS is both truly reversible and effective. Twenty-one patients aged 8 to 13 years (36 lower limbs LL) with coronal plane knee deformity were enrolled into this prospective case series from January 2021 to September 2023. Besides the routine monitoring of PETS efficacy, low dose CT knee of 32 treated physes was done 6 months after screw removal. In addition, lower limb length, mechanical lateral distal femur angle (mLDFA), and medial proximal tibial angle (MPTA) were recorded preoperatively and 6 to 17 months after screw removal for 24 LL to investigate physis behavior, technique reversibility, and resumption of bone growth after screw removal. The mean mechanical axis deviation (MAD) correction rate was 3.46mm/mo and 1.78mm/mo for genu valgum and genu varum patients, respectively. No physeal bony bars could be detected 6 months after screw removal for all patients. Out of 24 physis that underwent computerized radiography (CR) of the whole lower limb, 12 LL resumed their growth, 4 were stationary, while 8 were excluded due to inadequate calibration. A single physis showed rebound deformity, and another showed overcorrection in the genu valgum group. In addition to being a highly effective method of hemiepiphysiodesis, PETS was found to be reproducible, safe, and reversible when used in the juvenile and early adolescent pediatric population. IV-Prospective case series.

Attention Deficit Hyperactivity Disorder (ADHD): Forensic Issues

ADHD has long been recognised as disproportionately present in both juvenile and adult prison populations. This is so for a number of reasons, including the potential for persons with ADHD to be disinhibited, impulsive, impaired in executive functioning and chaotic in their lifestyle. A major challenge exists, though, to assist courts to understand better how ADHD may have played a role in criminal offending and thus to be relevant to evaluations of criminal culpability or even responsibility. Another issue that arises for expert assessment is how ADHD may make the experience of custodial detention especially burdensome and be relevant in this respect also for sentencing. This article considers the overall forensic context of ADHD in criminal litigation and reviews a selection of illustrative decisions from Canada, Australia, New Zealand and the United Kingdom to identify principles on the basis of which courts can make nuanced decisions that are suitably informed by expert mental health evidence about the forensic ramifications of ADHD.

Natural coral recovery despite negative population growth.

Demographic processes that ensure the recovery and resilience of marine populations are critical as climate change sends an increasing proportion on a trajectory of decline. Yet for some populations, recovery potential remains high. We conducted annual monitoring over 9 years (2012-2020) to assess the recovery of coral populations belonging to the genus Pocillopora. These populations experienced a catastrophic collapse following a severe typhoon in 2009. From the start of the monitoring period, high initial recruitment led to the establishment of a juvenile population that rapidly transitioned to sexually mature adults, which dominated the population within 6 years after the disturbance. As a result, coral cover increased from 1.1% to 20.2% during this time. To identify key demographic drivers of recovery and population growth rates (λ), we applied kernel-resampled integral projection models (IPMs), constructing eight successive models to examine annual change. IPMs were able to capture reproductive traits as key demographic drivers over the initial 3 years, while individual growth was a continuous key demographic driver throughout the entire monitoring period. IPMs further detected a pulse of reproductive output subsequent to two further Category 5 typhoon events during the monitoring period, exemplifying key mechanisms of resilience for coral populations impacted by disturbance. Despite rapid recovery, (i.e., increased coral cover, individual colony growth, low mortality), IPMs estimated predominantly negative values of λ, indicating a declining population. Indeed, while λ translates to a change in the number of individuals, the recovery of coral populations can also be driven by an increase in the size of surviving colonies. Our results illustrate that accumulating long-term data on historical dynamics and applying IPMs to extract demographic drivers are crucial for future predictions that are based on comprehensive and robust understandings of ecological change.

Comparative analysis of the syncytiotrophoblast in placenta tissue and trophoblast organoids using snRNA sequencing.

The outer surface of chorionic villi in the human placenta consists of a single multinucleated cell called the syncytiotrophoblast (STB). The unique cellular ultrastructure of the STB presents challenges in deciphering its gene expression signature at the single-cell level, as the STB contains billions of nuclei in a single cell. There are many gaps in understanding the molecular mechanisms and developmental trajectories involved in STB formation and differentiation. To identify the underlying control of the STB, we performed comparative single nucleus (SN) and single cell (SC) RNA sequencing on placental tissue and tissue-derived trophoblast organoids (TOs). We found that SN was essential to capture the STB population from both tissue and TOs. Differential gene expression and pseudotime analysis of TO-derived STB identified three distinct nuclear subtypes reminiscent of those recently identified in vivo . These included a juvenile nuclear population that exhibited both CTB and STB marker expression, a population enriched in genes involved in oxygen sensing, and a fully differentiated subtype. Notably, suspension culture conditions of TOs that restore the native orientation of the STB (STB out ) showed elevated expression of canonical STB markers and pregnancy hormones, along with a greater proportion of the terminally differentiated mature STB subtype, compared to those cultivated with an inverted STB polarity (STB in ). Gene regulatory analysis identified novel markers of STB differentiation conserved in tissue and TOs, including the chromatin remodeler RYBP, that exhibited STB-specific RNA and protein expression. Finally, we compared STB gene expression signatures amongst first trimester tissue, full-term tissue, and TOs, identifying many commonalities but also notable variability across each sample type. This indicates that STB gene expression is responsive to its environmental context. Our findings emphasize the utility of TOs to accurately model STB differentiation and the distinct nuclear subtypes observed in vivo , offering a versatile platform for unraveling the molecular mechanisms governing STB functions in placental biology and disease.

Investigating Vitamin D-Binding Protein's Role in Childhood Health and Development.

Vitamin D-binding protein (DBP), also known as Gc-globulin, is a protein that affects several physiological processes, including the transport and regulation of vitamin D metabolites. Genetic polymorphisms in the DBP gene have a significant impact on vitamin D levels and may have implications for disease risk. DBP polymorphisms are linked to differential immune responses, which could influence the onset of juvenile diseases. This narrative review examines the various roles of DBP, with a focus on bone health, immunological regulation, and lipid metabolism in children. Chronic disorders affected by DBP polymorphisms include bone abnormalities, autoimmune diseases, cardiovascular issues, childhood asthma, allergies, cystic fibrosis, acute liver failure, celiac disease, inflammatory bowel disease, and chronic kidney disease. Future research should focus on identifying the processes that underpin the many roles that DBP plays and developing customized therapeutics to improve health outcomes in the juvenile population.

Occurrence and Distribution of Meloidogyne spp. in Fields Rotated with Sweetpotato and Host Range of a North Carolina Population of Meloidogyne enterolobii.

Root-knot nematodes (RKNs, Meloidogyne spp.) are some of the most economically important and common plant parasitic nematodes in North Carolina (NC) cropping systems. Soil samples collected from fields planted with crops rotated with sweetpotato (Ipomoea batatas [L.] Lam.) in 39 NC counties in 2015 to 2018 were processed at the NC Nematode Assay Laboratory. The occurrence of second-stage juvenile (J2) RKN populations was examined based on collection year, month, county, and previous planted crop. The highest number of RKN-positive samples originated from Cumberland (53%), Sampson (48%), and Johnston (48%) counties. The highest average RKN population density was detected in Sampson (147 J2/500 cm3 of soil) and Nash (135 J2/500 cm3 of soil) counties, while Wayne (7 J2/500 cm3 of soil) and Greene (11 J2/500 cm3 of soil) counties had the lowest average RKN population density. Meloidogyne enterolobii is a new invasive species that is impacting sweetpotato growers of NC. The host status of an NC population of M. enterolobii, the guava RKN, was determined by examining eggs per gram of fresh root (ER) and the final nematode egg population divided by the initial population egg count (reproductive factor, RF) in greenhouse experiments. This included 18 vegetable, field, and cover crops and weed species. The tomato 'Rutgers' was used as a susceptible control. Cabbage 'Stonehead', pepper 'Red Bull', and watermelon 'Charleston Gray' and 'Fascination' were hosts and had similar mean ER values to the positive control, ranging from 64 to 18,717. Among field crops, cotton, soybean 'P5018RX', and tobacco were hosts with ER values that ranged from 185 to 706. Members of the Poaceae family such as sweet corn (Zea mays) and sudangrass (Sorghum × drummondii) were nonhosts to M. enterolobii, and the mean ER values ranged from 1.85 to 7. The peanut 'Tifguard' and winter wheat (Triticum aestivum) also had lower ER values than the vegetable hosts. Growers should consider planting less susceptible hosts or nonhosts such as peanut, sudangrass, sweet corn, and winter wheat in 2- to 3-year crop rotations to lower populations of this invasive nematode.

Temporal variations in immune and inflammatory markers following rodent juvenile traumatic brain injury

Traumatic brain injury (TBI) is one of the leading causes of death and disability in the juvenile population. TBI is associated with elevations in inflammatory signaling. However, the temporal changes in immune and inflammatory markers following TBI, particularly in juvenile studies utilizing the Closed Head Injury Model of Engineered Rotational Acceleration (CHIMERA), have not been fully elucidated. The current study aimed to determine the time course of changes to immune cell expression throughout the first four days following juvenile TBI via the CHIMERA. Male Long Evans rats sustained either a TBI or a Sham TBI via the CHIMERA on post-natal day (PND) 30. Sham animals were euthanized at 3 hours (h) post-injury. TBI animals were euthanized at 0, 3, 6, 12, 24, or 96 h post-injury. Hippocampus samples were collected for use in QRT-PCR. The mRNA expression of cytokines IL1b and TNF-α was significantly elevated at 6 h, and C1q C chain (C1QC), a dendritic cell marker, was significantly elevated at 24 h. The mRNA expression of CD68, a marker for macrophages, was significantly elevated at 6, 24, and 96 h post-injury compared to Sham. CD3G, a marker for T cells, was significantly elevated at 6 hours post-injury. However, the mRNA expression of PTPRC, a marker for leukocytes, was not significantly altered throughout the time periods evaluated. To follow up on these studies, juvenile rats were injured and brains and blood were harvested 48 h post-injury comparing Sham and TBI. Peripheral blood lymphocytes were obtained and sorted by marker-specific antibodies. In the peripheral blood, there was a significantly higher number of CD3+ total T cells, CD3+/CD8 cytotoxic T cells, and CD3+/CD4+ helper T cells in the TBI group compared to the Sham, but CD45R+ total B cells and natural killer (NK) cells were not significantly different. Superior hemi-sected cortices were also used for immune cell extraction. There was a significantly lower number of NK cells and CD45R+ total B cells in the TBI group compared to the Sham, but CD45+ leukocytes and CD3+ total T cells were not significantly different. Further work is needed to understand the relationship between the reduction of specific cells in the brain with the elevation of cells in the peripheral blood. This work is supported by T32HL105324 to AMS. 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.

Clodronate disodium does not produce measurable effects on bone metabolism in an exercising, juvenile, large animal model.

Bisphosphonates are commonly used to treat and prevent bone loss, but their effects in active, juvenile populations are unknown. This study examined the effects of intramuscular clodronate disodium (CLO) on bone turnover, serum bone biomarkers (SBB), bone mineral density (BMD), bone microstructure, biomechanical testing (BT), and cartilage glycosaminoglycan content (GAG) over 165 days. Forty juvenile sheep (253 ± 6 days of age) were divided into four groups: Control (saline), T0 (0.6 mg/kg CLO on day 0), T84 (0.6 mg/kg CLO on day 84), and T0+84 (0.6 mg/kg CLO on days 0 and 84). Sheep were exercised 4 days/week and underwent physical and lameness examinations every 14 days. Blood samples were collected for SBB every 28 days. Microstructure and BMD were calculated from tuber coxae (TC) biopsies (days 84 and 165) and bone healing was assessed by examining the prior biopsy site. BT and GAG were evaluated postmortem. Data, except lameness data, were analyzed using a mixed-effects model; lameness data were analyzed as ordinal data using a cumulative logistic model. CLO did not have any measurable effects on the skeleton of sheep. SBB showed changes over time (p ≤ 0.03), with increases in bone formation and decreases in some bone resorption markers. TC biopsies showed increasing bone volume fraction, trabecular spacing and thickness, and reduced trabecular number on day 165 versus day 84 (p ≤ 0.04). These changes may be attributed to exercise or growth. The absence of a treatment effect may be explained by the lower CLO dose used in large animals compared to humans. Further research is needed to examine whether low doses of bisphosphonates may be used in active juvenile populations for analgesia without evidence of bone changes.