Neuroimaging in Dementia: More than Typical Alzheimer Disease

Alzheimer disease (AD) is the most common cause of dementia. The prevailing theory of the underlying pathology assumes amyloid accumulation followed by tau protein aggregation and neurodegeneration. However, the current antiamyloid and antitau treatments show only variable clinical efficacy. Three relevant points are important for the radiologic assessment of dementia. First, besides various dementing disorders (including AD, frontotemporal dementia, and dementia with Lewy bodies), clinical variants and imaging subtypes of AD include both typical and atypical AD. Second, atypical AD has overlapping radiologic and clinical findings with other disorders. Third, the diagnostic process should consider mixed pathologies in neurodegeneration, especially concurrent cerebrovascular disease, which is frequent in older age. Neuronal loss is often present at, or even before, the onset of cognitive decline. Thus, for effective emerging treatments, early diagnosis before the onset of clinical symptoms is essential to slow down or stop subsequent neuronal loss, requiring molecular imaging or plasma biomarkers. Neuroimaging, particularly MRI, provides multiple imaging parameters for neurodegenerative and cerebrovascular disease. With emerging treatments for AD, it is increasingly important to recognize AD variants and other disorders that mimic AD. Describing the individual composition of neurodegenerative and cerebrovascular disease markers while considering overlapping and mixed diseases is necessary to better understand AD and develop efficient individualized therapies

Neuroimaging in Dementia:More than Typical Alzheimer Disease

Alzheimer disease (AD) is the most common cause of dementia. The prevailing theory of the underlying pathology assumes amyloid accumulation followed by tau protein aggregation and neurodegeneration. However, the current antiamyloid and antitau treatments show only variable clinical efficacy. Three relevant points are important for the radiologic assessment of dementia. First, besides various dementing disorders (including AD, frontotemporal dementia, and dementia with Lewy bodies), clinical variants and imaging subtypes of AD include both typical and atypical AD. Second, atypical AD has overlapping radiologic and clinical findings with other disorders. Third, the diagnostic process should consider mixed pathologies in neurodegeneration, especially concurrent cerebrovascular disease, which is frequent in older age. Neuronal loss is often present at, or even before, the onset of cognitive decline. Thus, for effective emerging treatments, early diagnosis before the onset of clinical symptoms is essential to slow down or stop subsequent neuronal loss, requiring molecular imaging or plasma biomarkers. Neuroimaging, particularly MRI, provides multiple imaging parameters for neurodegenerative and cerebrovascular disease. With emerging treatments for AD, it is increasingly important to recognize AD variants and other disorders that mimic AD. Describing the individual composition of neurodegenerative and cerebrovascular disease markers while considering overlapping and mixed diseases is necessary to better understand AD and develop efficient individualized therapies.</p

Equine cervical intervertebral disc degeneration is associated with location and MRI features

Morphology of the equine cervical intervertebral disc is different from that in humans and small companion animals and published imaging data are scarcely available. The objectives of this exploratory, methods comparison study were (a) to describe MRI features of macroscopically nondegenerated and degenerated intervertebral discs (b) to test associations between spinal location and macroscopic degeneration or MRI-detected annular protrusion and between MRI-detected annular protrusion and macroscopic degeneration, and (c) to define MRI sequences for characterizing equine cervical intervertebral disc degeneration. Ex vivo MRI of intervertebral discs was performed in 11 horses with clinical signs related to the cervical region prior to macroscopic assessment. Mixed-effect logistic regression modeling included spinal location, MRI-detected annular protrusion, and presence of macroscopic degeneration with "horse" as random effect. Odds ratio and 95% confidence interval were determined. Reduced signal intensity in proton density turbo SE represented intervertebral disc degeneration. Signal voids due to presence of gas and/or hemorrhage were seen in gradient echo sequences. Presence of macroscopic intervertebral disc degeneration was significantly associated with spinal location with odds being higher in the caudal (C5 to T1) versus cranial (C2 to C5) part of the cervical vertebral column. Intervertebral discs with MRI-detected annular protrusion grades 2-4 did have higher odds than with grade 1 to have macroscopic degeneration. It was concluded that MRI findings corresponded well with gross macroscopic data. Magnetic resonance imaging of the equine cervical intervertebral disc seems to be a promising technique, but its potential clinical value for live horses needs to be explored further in a larger and more diverse population of horses

Comparison of efficacy of needle‑free injection versus injection by needle for iron supplementation of piglets: a double blind randomized controlled trial

Background In pig husbandry, most piglets receive an intramuscular injection with iron around three days of age for the prevention of hypochromic, microcytic anaemia. In recent years an increased interest is noted for needle-free injections, because of efficiency and safety for man and animal. This study aims to support the evidence on efficacy to extent the registration of a commercial iron supplement with a needle-free administration application. To this aim the study has two objectives: 1) to determine the effect of needle-free injection of the iron supplement on the mean blood Haemoglobin level at weaning, as primary outcome, and mean Haematocrit and mean Body weight of pigs at weaning as secondary outcome compared to no treatment, as main determinant of iron deficiency anaemia in piglets at time of weaning; 2) to compare the effects of needle-free administration of the iron supplement with regular injection by needle, with regard to the course over time of Haemoglobin, Haematocrit, piglet growth and the differentiated haematological and serum iron parameters. Methods A double blind randomized controlled trial was conducted with 72 piglets, 8 piglets per litter from 9 litters. At three days of age pigs were selected, based on body weight, and random allocated to three study groups: a) control non-treated group (2 pigs per litter, 18 in total), b) a group with regular iron injection by needle injection (3 pigs per litter, 27 in total), c) a group that received iron by needle-free injection (3 pigs per litter, 27 in total). At four points in time (day 3, 14, 26 and 40) piglets were weighed and bled to analyse the dynamics of red blood counts and haematological parameters as well as serum iron parameters. The primary outcome parameter was the Haemoglobin (Hb) level on day 26. Of secondary importance were Haematocrit (Ht) and body weight (BW) at weaning and parameters with tertiary importance were the course of Hb, Ht and differentiated red blood cell parameters, serum iron, iron binding capacity and iron saturation. In the statistical analyses, linear mixed effect regression modelling was used to account for repeated measures within litters and pigs. Results The analyses showed that needle-free administration was as efficacious to prevent iron deficiency anaemia at day 26 as administration using regular needle injection, compared to the control group. The mean level of Hb and Ht of pigs in the needle and needle-free group did not differ significantly. No side effects were observed. Conclusion It is concluded that needle-free iron administration of the tested product is as efficacious as regular administration by needle injection

Rotation of 3D Anatomy Models Is Associated with Underperformance of Students with Low Visual-Spatial Abilities: A Two-Center Randomized Crossover Trial

Virtual 3D models can be an animal-free alternative to cadaveric dissection to learn spatial anatomy. The aim of this study was to investigate if the learning outcome differs when studying 3D models with a 360° rotatable interactive monoscopic 3-dimensional (iM3D) or an interactive monoscopic 2-dimensional (iM2D) visualization, and whether the level of visual-spatial ability (VSA) influences learning outcome. A two-center randomized crossover trial was conducted during the Laboratory Animals Science Course (March 2021–March 2022). Participants studied a 3D rat model using iM3D and iM2D. VSA was assessed by a 24-item mental rotation test and learning outcome by two knowledge tests. Data from 69 out of 111 recruited participants were analyzed using linear regression. Participants with low VSA performed significantly worse compared to participants with medium or high VSA when using iM3D, but equally well when using iM2D. When VSA level was disregarded, participants performed equally well with both visualizations. Rotation in iM3D requires the student to construct a mental 3D image from multiple views. This presumably increases cognitive load, especially for students with low VSA who might become cognitively overloaded. Future research could focus on adapting the visualization technique to students’ personal needs and abilities

Prevalence and demographic risk factors of Mycobacterium tuberculosis infections in captive Asian elephants (Elephas maximus) based on serological assays

To address putative TB statuses of elephants and to identify and quantify potential demographic risk factors for TB, three ELISAs specific for different mycobacterial antigens (ESAT6, CFP10, MPB83) and the TB Stat-Pak assay were used as surrogate serological markers for TB infection in elephants. In view of the low number of animals of which the infected status could be confirmed (4 out of 708) Latent Class Analyses of TB serology test outcomes was used to predict the putative TB status of each of 708 elephants as positive (17.3%), inconclusive (48.7%), or negative (34%) when assessed on a population basis. Correlation between test performance of the individual assays was high between the ELISAs, but low with that of the TB Stat-Pak assay. Risk factors, assessed based on cut off values for each of the ELISAs determined by ROC analysis, included sex, BCS, age, working time, feed type, management system, camp size and region. Old age elephants were more likely to show a positive TB serology test outcome, than younger ones. Elephants working 7 h per day and the ones in good condition BCS (7–11) were less likely to be positive in TB serology testing. In addition, fewer animals in the large camp size (31–50 elephants) were found to be positive in ELISA tests, compared to elephants in the other camp sizes. In this study, the North region had the lowest percentages of elephants with positive TB test outcome, the West region and to a lesser extend the other regions showed clearly higher percentages of positive animals. Even though assays used in the present study have not been validated yet, results obtained showed promise as diagnostic or screening tests. For the diagnosis of animals suspected to be infected, the ELISA tests, once further optimized for the individual antigens, can be used in parallel. For screening of complete camps for presence or absence of infection, a single optimized ELISA test can be utilized.Faculty of Veterinary Medicine, Chiangmai Universityhttps://www.frontiersin.org/journals/veterinary-science#am2022Veterinary Tropical Disease

Wool cortisol as putative retrospective indicator of stress in ewes during the third trimester of pregnancy, and their newborns: effects of parity and litter size — an exploratory study

Stress is an important factor in animal welfare. Hair or wool cortisol concentrations are considered to be potential long-term indicators of stress experienced by an animal. Using Swifter sheep, we investigated whether ewe parity and litter size affect the wool cortisol concentrations in ewes and their offspring. We hypothesized that multiparous ewes and their offspring would have higher wool cortisol concentrations than primiparous ewes and their offspring, that ewes with larger litters and their offspring would have lower wool cortisol concentrations than ewes with smaller litters and their offspring, that male lambs would have higher wool cortisol concentrations than female lambs, and that the wool cortisol concentrations in the wool of ewes and their lambs would be correlated. Lamb wool grows in utero during the third trimester of pregnancy. In ewes, the shave–reshave method was used so that wool samples from ewes also covered approximately the last trimester of pregnancy. Our study confirmed that litter size affected ewe wool cortisol concentrations: ewes that gave birth to larger litters (i.e., 3 or 4 lambs) had higher wool cortisol concentrations than ewes that gave birth to smaller litters (i.e., 1 or 2 lambs). There was no evidence that the wool cortisol concentrations of the ewes and their lambs were correlated. Neither litter size nor parity of the ewe affected wool cortisol in the lambs. Our study confirms that wool cortisol can be reliably measured in ewes and their newborn lambs, and suggests that it may be useful as a retrospective indicator of stress during the last trimester of pregnancy

The effects of transport of 18-day old hatching eggs on physiology and behaviour of slow growing broiler chicken

Incubation and hatching commonly takes places at hatcheries, separate from the grow-out facilities where broiler chicks are raised. This means that chicks are sorted and transported immediately after hatch, during which time they typically do not have access to feed and water, and are subjected to transport stress. Recently, innovative housing systems are being developed in which fertilised eggs are transported on embryonic day 18 (E18) from the hatchery to the grow-out facility, where they hatch on day 21. In chicken, the hypothalamic– pituitary–adrenal (HPA)-axis becomes functional around embryonic day 14–16. It is therefore conceivable that transport of eggs at E18 may lead to a stress response in the chick embryo. Exposure to prenatal stress may affect the coping capacity of the individual and negatively impact its further development. We investigated whether prolonged transport on E18 has effects on the development of a slow growing broiler chicken strain (Hubbard JA257). E18 eggs were transported for either 41 min (short transport, ST) or 219 min (long transport, LT). Transportation significantly increased embryonic heart rate after ST. This increase continued during an intermediate measure at 120 min. The increased embryonic HR then remained high at measurement immediately following LT. We did not find effects of prolonged transport on behavioural parameters measured in the juvenile chicken in the tonic immobility and open field test. Concentrations of feather corticosterone as well as faecal corticosterone metabolites did not differ on postnatal day 36. We showed that transport leads to an autonomic stress response in chicken embryos at E18, but that this elevation had no further effects on other indicators of prenatal stress. Nevertheless, our results emphasise that transport of incubated eggs should be as refined as possible to minimise the exposure to stress

Effects of lighted incubation and foraging enrichment during rearing on individual fear behavior, corticosterone, and neuroplasticity in laying hen pullets

Environmental conditions during incubation and rearing can influence stress responsivity of laying hen pullets throughout their lifespan, and therefore have important implications for their welfare. In this study, a 12:12h green LED light-dark cycle during incubation and larvae provisioning as enrichment during rearing were tested as strategies to optimize early-life conditions and thereby decrease stress responsivity in ISA Brown laying hens. A combination of parameters was measured to indicate neuronal, physiological, and behavioral changes that may affect fear and stress. The proteins calbindin D28k (calbindin1), doublecortin (DCX), and neuronal nuclein protein (NeuN) were quantified after hatch as a proxy for brain plasticity. Plasma and feather corticosterone levels were measured after hatch and at the end of the rearing phase, and fearfulness was investigated through a series of behavioral tests (i.e., voluntary approach, open field, tonic immobility, and manual restraint tests). No effects of light during incubation were found on calbindin1, DCX, or NeuN. Neither of the treatments affected corticosterone levels in blood plasma and feathers. Light-incubated pullets showed less fearfulness towards humans in the voluntary approach test, but not in the other behavioral tests reported in this study. Larvae provisioning had no effect on behavior. Our study showed minor effects of light during incubation and no effects of enrichment during rearing on stress responsivity of laying hen pullets. The small effects may be explained by the enriched rearing conditions for all birds in this experiment (low stocking density, natural daylight, and 24/7 classical music). Given the promising results of lighted incubation in other studies, which were mostly performed in broiler chickens, and evidence regarding the positive effects of enrichment during rearing, the potential of these strategies to improve laying hen welfare needs to be explored further

Thermotropic and structural effects of poly(malic acid) on fully hydrated multilamellar DPPC–water systems

The thermotropic and structural effects of low molecular weight poly(malic acid) (PMLA) on fully hydrated multilamellar dipalmitoylphosphatidylcholine (DPPC)-water systems were investigated using differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), and freeze-fracture transmission electron microscopy (FFTEM). Systems of 20 wt% DPPC concentration and 1 and 5 wt% PMLA to lipid ratios were studied. The PMLA derivatives changed the thermal behavior of DPPC significantly and caused a drastic loss in correlation between lamellae in the three characteristic thermotropic states (i.e., in the gel, rippled gel and liquid crystalline phases). In the presence of PBS or NaCl, the perturbation was more moderate. The structural behavior on the atomic level was revealed by FTIR spectroscopy. The molecular interactions between DPPC and PMLA were simulated via modeling its measured infrared spectra, and their peculiar spectral features were interpreted. Through this interpretation, the poly(malic acid) is inferred to attach to the headgroups of the phospholipids through hydrogen bonds between the free hydroxil groups of PMLA and the phosphodiester groups of DPPC