Postmortem Dissection Research Articles

Morphological evidence of a potential arrhythmogenic substrate in the caudal and cranial vena cava in horses.

Three-dimensional electro-anatomical mapping, previously performed in horses with atrial arrhythmias, has demonstrated the medial region of the caudal vena cava (CaVC), 1-8 cm caudal to the fossa ovalis, as an anatomical predilection site for atrial tachycardia associated with areas of slow conduction and conduction block. Slow conduction has also been recorded in the cranial vena cava (CrVC). To investigate the morphological characteristics of the myocardial sleeves (MS) in the CaVC and CrVC, in order to identify a potential substrate of right sided atrial arrhythmias. Cross sectional. Post-mortem dissection of 37 hearts from adult warmblood horses without known cardiovascular disease. Macroscopic examination of the myocardial distribution, evaluated the MS area, length, width, and shape in the CaVC and the CrVC. At least 2 samples from each vena cava MS were histologically examined using Masson's trichrome staining. Myocardial sleeves into the medial CaVC and into the CrVC were observed in all horses and showed variations in distribution, shape, and size between horses. Their mean ± standard deviation length from the limbus into the CaVC reached 5.7 ± 1.0 cm (maximum 8.3 cm), and from the azygos vein into the CrVC 5.3 ± 1.6 cm (maximum 8.6 cm). Myocardium-free islands were observed in the CaVC and CrVC in 30% and 6% of horses, respectively. Histologically, MS showed a non-uniform myocardial fibre arrangement, with presence of fibroadipose tissue, features known to result in slow conduction and pro-arrhythmia. Study only included horses without history of atrial arrhythmia. Myocardial sleeves are present in both CaVC and CrVC, showing anatomical variations between horses. Tissue characteristics known to favour re-entry were identified indicating that these venae cavae MS are a potential substrate for atrial tachyarrhythmias and a target for treatment by ablation.

Direct Inside-Out Observation of Superficial White Matter Fasciculi in the Human Brain.

Background: Recent methodological advances in the study of the cerebral white matter have left short association fibers relatively underexplored due to their compact and juxtacortical nature, which represent significant challenges for both post-mortem post-cortex removal dissection and magnetic resonance-based diffusion imaging. Objective: To introduce a novel inside-out post-mortem fiber dissection technique to assess short association fiber anatomy. Methods: Six cerebral specimens were obtained from a body donation program and underwent fixation in formalin. Following two freezing and thawing cycles, a standardized protocol involving peeling fibers from deep structures towards the cortex was developed. Results: The inside-out technique effectively exposed the superficial white matter. The procedure revealed distinguishable intergyral fibers, demonstrating their dissectability and enabling the identification of their orientation. The assessment of layer thickness was possible through direct observation and ex vivo morphological magnetic resonance imaging. Conclusion: The inside-out fiber technique effectively demonstrates intergyral association fibers in the post-mortem human brain. It adds to the neuroscience armamentarium, overcoming methodological obstacles and offering an anatomical substrate essential for neural circuit modeling and the evaluation of neuroimaging congruence. Impact statement The inside-out fiber dissection technique enables a totally new perception of cerebral connectivity as the observer navigates inside the parenchyma and looks toward the cerebral surface with the subcortical white matter and the cortical mantle in place. This approach has proven very effective for exposing intergyral association fibers, which have shown to be much more distinguishable from an inner perspective. It gave rise to unprecedented images of the human superficial white matter and allowed, for the first time, direct observation of this vast mantle of fascicles on entire cerebral hemisphere aspects.

Multimodal study of multilevel pulvino-temporal connections: a new piece in the puzzle of lexical retrieval networks.

Advanced methods of imaging and mapping the healthy and lesioned brain allowed to identify the cortical nodes and white matter tracts supporting the dual neurofunctional organization of language networks in a dorsal phonological and a ventral semantic stream. Much less understood are the anatomical correlates of the interaction between the two streams, one hypothesis being that of a sub-cortically mediated interaction, through crossed cortico-striato-thalamo-cortical and cortico-thalamo-cortical loops. In this regard, the pulvinar is the thalamic subdivision that has most regularly appeared as implicated in the processing of lexical retrieval. However, descriptions of its connections with temporal (language) areas remain scarce. Here we assess this pulvino-temporal connectivity using a combination of state-of-the-art techniques: white matter stimulation in awake surgery and post-operative diffusion MRI (n = 4), virtual dissection from the Human Connectome Project 3 T and 7 T datasets (n = 172), and operative microscope-assisted post-mortem fiber dissection (n = 12). We demonstrate the presence of four fundamental fiber contingents: i) the anterior component (Arnold's bundle proper) initially described by Arnold in the 19th century, and destined to the anterior temporal lobe; ii) the Optic Radiations (OR)-like component, that leaves the pulvinar accompanying the optical radiations and reaches the posterior basal temporal cortices; iii) the lateral component, that crosses orthogonally the temporal stem and reaches the middle temporal gyrus; and iv) the Auditory Radiations (AR)-like component, that leaves the pulvinar accompanying the auditory radiations to the superomedial aspect of the temporal operculum, just posteriorly to Heschl's gyrus. Each of those components might correspond to a different level of information processing involved in the lexical retrieval process of picture naming.

Applications of hybrid structure light three‐dimensional scanning in neurodegenerative disease autopsy brain banking

AbstractBackgroundPostmortem magnetic resonance imaging (MRI) and three‐dimensional (3D) printing has been demonstrated to be a feasible approach for the creation of tissue matrices to aid in postmortem brain dissection. We aimed to extend this approach using hybrid structure light technology (visible and infrared) 3D scanning to generate brain models as a digital resource and operational tool for human neurodegenerative disease brain banks.MethodA consecutive series of 56 brains accessioned into the Glenn Biggs Institute Brain Bank were imaged using an EinScan H handheld 3D scanner. Five brains were selected for generation of tissue matrices, with infratentorial structures removed using 3D object post‐processing software tools. Matrices were printed using a Raise3D Pro2 printer and 1.75‐mm polylactic acid premium filament.ResultEach scan was approximately an hour to complete, including capture and alignment of a lateral and a medial surface scan for each brain. Raw scan files (DAT and BRAP‐PRJ) averaged 5.47 GB and 3D object files were 12,991 KB for 3MF and 18,067 KB for OBJ file types. For cases with tissue matrices, average print time was 42 hours with an average filament consumption of 338 g. Brain cutting with the tissue matrices was performed in a standardized manner, with superb control for section thickness and planar orientation compared to brains cut without a matrix.Conclusion3D scanning of postmortem autopsied brains is a simple and useful strategy to generate models with utility in guided tissue sectioning and storage (practice), surface area volumetric analysis (research) and virtual reality/augmented reality neuroanatomy training (education) for Alzheimer’s disease and related dementias.

Anagonia lasiophthalma (Diptera: Tachinidae): Survey, identification, and biological traits of a new biological control agent of the Eucalyptus snout beetle, Gonipterus platensis (Coleoptera: Curculionidae)

The Eucalyptus snout beetle, Gonipterus platensis, is one of the main pests of eucalypts outside its native range. Among the available control methods for this pest, classical biological control with Anaphes nitens (Hymenoptera: Mymaridae) has been the most widely used, but it is not always effective. To identify other natural enemies that might provide further pest control, a field survey was conducted in Tasmania, Australia, in which Anagonia spp. were found to parasitize 7 % of Gonipterus spp. larvae. One species was subsequently identified as the solitary parasitoid Anagonia lasiophthalma, based on direct comparisons with research collection material in Australia. To assess the potential of this species as a biological control agent, A. lasiophthalma was reared on G. platensis larvae under quarantine conditions, and its biology and reproductive strategy were studied in the laboratory. Global mating success was 58 %, with 66 of the 114 A. lasiophthalma females analyzed mating within an established 10-day period. Most females mated within 48 h after emergence and started to parasitize about a week later. Dissections of mated females showed that this species is ovolarviparous, incubating its eggs in an ovisac, before inserting them “ready-to-hatch” directly into the host using a piercing structure derived from the modification of a sternite in the female terminalia. Over the course of their lifetime, females on average produced 35 offspring and post-mortem dissections revealed an additional 32 eggs in the ovisac. Longevity of females and males was similar, ranging between 55 and 84 days, but females maintained without host larvae lived longer than females exposed to host larvae. These results provide relevant information to improve laboratory rearing protocols and suggest that A. lasiophthalma may be effective against the snout beetle in its invaded range.

Bladder Agenesis: A Systematic Review.

Bladder agenesis is a rare congenital deformity characterized by the absence of the bladder. It is primarily observed in postmortem dissections of stillbirths rather than live births. The condition is often associated with other congenital anomalies, leading to the hypothesis that most affected fetuses do not survive to term. However, the exact cause and specific associated anomalies remain unclear and poorly described in the literature. The limited mention of bladder agenesis in textbooks and literature underscores the importance of creating a comprehensive source for future research in this field. Therefore, our objective is to collect and analyze data on bladder agenesis, focusing on associated anomalies and potential causes, to enhance our understanding of the condition. We conducted a thorough review of reports collected from three databases, Google Scholar, PubMed, and Science Direct, last searched on July 30, 2023, starting with 327 reports. Excluding duplicates and records written in languages other than English, veterinary studies, irrelevant reports, or stillbirths. Inclusion criteria were the following: cases must have proven bladder agenesis, not hypoplasia, and must have most of the information, including the age of diagnosis, presenting symptoms, gender, associated anomalies, and management or outcome of the patient. A quality assessment was conducted according to the Joanna Briggs Institute checklist for case reports. A total of 65 case reports from 56 articles were included in the review. Through our manual analysis, we documented a wild array of malformations associated with bladder agenesis. Among the reports reviewed, 93% exhibited urinary system malformations beside bladder agenesis, 77% were found to have reproductive malformations, 44% had gastrointestinal anomalies, 38% showed musculoskeletal malformations, 28% had cardiac malformations, and another 28% had vascular anomalies. The overall mortality rate was 38%, with a higher rate of 74% for males compared to 20% for females. By collating and analyzing those case reports, we aim to contribute to a better understanding of bladder agenesis and its associated anomalies, facilitating further investigations and advancements in the field.

Sensory Evaluation of Rabbit Meat from Individuals Fed Functional and More Sustainable Diets Enriched with Freshwater Cladophora glomerata Macroalgal Biomass.

Maintaining meat quality is essential to sustainable livestock management. Therefore, identifying alternative feed materials while considering consumer acceptance is crucial. So, the aim of this study was to evaluate the effect of C. glomerata-biomass-supplemented feeds on rabbit muscles' physical properties, sensory profiles, and evaluators' emotional responses to them. A total of thirty 52-day-old weaned Californian breed rabbits were randomly allocated to one of three dietary treatments: standard compound diet (SCD), SCD supplemented with 4% C. glomerata (CG4), or SCD supplemented with 8% C. glomerata (CG8). After the 122-day-old rabbits were slaughtered, post-mortem dissection of the rabbit Longissimus dorsi (LD) and hind leg (HL) muscles was conducted. The physical and histomorphometric features, sensory analyses, and emotional responses to the rabbit's muscles were determined. Study results revealed CG4 and CG8 treatments significantly increased rabbit muscle moisture, while CG8 increased cooking losses in HL muscles (p < 0.05). Moreover, both CG treatments reduced the darkness and redness of fresh and cooked rabbit muscles compared to SCD (p < 0.05). CG8 treatment compared to SCD resulted in longer LD muscle fibers (p < 0.05). Evaluators discovered that the average scores for each sensory description of rabbit meat are acceptable and that consuming CG8-HL muscles can increase happiness based on emotional responses. Consequently, replacing traditional feed materials in rabbit feed with C. glomerata can lead to not only more sustainable production but also more consumer-acceptable rabbit meat.

Destabilization of the medial meniscus to induce post-traumatic osteoarthritis in domestic pigs

IntroductionPost-traumatic osteoarthritis (PTOA) develops following traumatic articular insult. One model system used to study the progression and treatment of PTOA is the destabilization of the medial meniscus (DMM) as first described by Glasson et al performed in mini-pigs. Miniature pigs are less available, more expensive, and have synovial fluid sampling limitations, limiting the availability of osteoarthritis biomarkers compared to domestic pigs. ObjectivesThe following technical note details stepwise procedures and animal welfare strategies for the use of Yorkshire pigs as a large animal PTOA model. MethodsThe following technical note details stepwise procedures to perform peroperative saphenous nerve block, DMM, and subsequent postoperative management in Yorkshire pigs as a large animal PTOA model. ResultsAt 4 weeks post-operatively, all pigs develop mild-moderate PTOA based on postmortem joint dissections. ConclusionsThis technical note provides further details on the arthrotomy approach to destabilize the medial meniscus of domestic pigs as a model of PTOA.

White matter BOLD signals at 7 Tesla reveal visual field maps in optic radiation and vertical occipital fasciculus

There is growing evidence that blood-oxygen-level-dependent (BOLD) activity in the white matter (WM) can be detected by functional magnetic resonance imaging (fMRI). However, the functional relevance and significance of WM BOLD signals remain controversial. Here we investigated whether 7T BOLD fMRI can reveal fine-scale functional organizations of a WM bundle. Population receptive field (pRF) analyses of the 7T retinotopy dataset from the Human Connectome Project revealed clear contralateral retinotopic organizations of two visual WM bundles: the optic radiation (OR) and the vertical occipital fasciculus (VOF). The retinotopic maps of OR are highly consistent with post-mortem dissections and diffusion tractographies, while the VOF maps are compatible with the dorsal and ventral visual areas connected by the WM. Similar to the grey matter (GM) visual areas, both WM bundles show over-representations of the central visual field and increasing pRF size with eccentricity. Hemodynamic response functions of visual WM were slower and wider compared with those of GM areas. These findings clearly demonstrate that WM BOLD at 7 Tesla is closely coupled with neural activity related to axons, encoding highly specific information that can be used to characterize fine-scale functional organizations of a WM bundle.

Association fiber tracts related to Broca's area: A comparative study based on diffusion spectrum imaging and fiber dissection.

Broca's area, made up of Brodmann areas (BA) 44 and 45 in the ventrolateral frontal region, is associated with language production and articulation. A comprehensive network analysis of Broca's area is necessary for understanding language function, which is still lacking. In this study, we attempted to investigate the association fiber tracts related to Broca's area using both diffusion spectrum imaging (DSI) and postmortem fiber dissection. DSI was performed on 10 healthy subjects and an atlas comprising the average data of 842 healthy subjects from the Human Connectome Project. Fiber dissection was implemented in 10 cerebral hemispheres of cadaver donors. The following five association fiber tracts related to Broca's area were identified: first, the distinct fasciculus of the inferior fronto-occipital fasciculus (IFOF), from Broca's area (BA44, BA45) and pars orbitalis (BA47) to the parietal and occipital lobes; second, the ventral superior longitudinal fasciculus (SLF-III), from the supramarginal gyrus (BA40) to the ventral precentral gyrus (PreG, BA6) and posterior Broca's area (BA44); third, the arcuate fascicle (AF), from the superior, middle, and inferior temporal gyrus (BA20, BA21, BA22) to Broca's area (BA44, BA45) and ventral PreG; fourth, the frontal aslant tract (FAT), from Broca's area (BA44, BA45) to the lateral superior frontal gyrus (SFG), medial SFG, and supplementary motor area (BA6, BA8, BA9); and fifth, the frontal longitudinal fasciculus (FLF), a novel intralobar frontal association fiber tract, from the anterior part of the middle frontal gyrus (MFG, BA46) and Broca's area (BA45) to the caudal MFG (BA8), caudal SFG, and dorsal PreG (BA6). Moreover, compared with the left FAT, the right FAT covered almost the entire inferior frontal gyrus (BA44, BA45, BA47). The cross validation between DSI and fiber dissection revealed a good consistence in the association fiber tracts of Broca's area. Combining DSI and fiber dissection, this study first identified five association fiber tracts related to Broca's area and characterized their structure and anatomy comprehensively. The frameworks provided key elements for functional research in Broca's area.

A1-A2 anterior cerebral artery fenestration. a case report of a rare anatomical variant

Cerebral vascular anatomical variations are not uncommon in the human population. Their prevalence is not exactly known, as most of them are incidentally diagnosed on angiography or postmortem dissections. We present a rare fenestration of the A1 segment of the anterior cerebral artery presenting with a ruptured saccular aneurysm. A 42-year-old hypertensive patient presented unconscious following a ruptured saccular aneurysm. The computer tomography angiography showed a fenestration of the right A1 segment of the anterior cerebral artery (ACA). The medial segment of the A1 was communicating with the left ACA via the Anterior communicating artery, while the lateral segment was directly joining the A2 segment of the same side. Intraoperatively, the two segments were identified as separate vascular structures not sharing adventitia, and of equal caliber. The aneurysm arising from the bifurcation was clipped. The patient recovered with no neurological deficits. Many vascular anomalies like fenestrations and bifurcations are underdiagnosed, as many of them remain asymptomatic and are discovered incidentally on postmortem dissection or angiography for other pathologies. This has led to a paucity of cases to determine the prevalence in the human population. Good knowledge of the vascular anatomy variations and associated risk of aneurysm is important for the vascular neurosurgeons.

HF01-14 DESCENDING THROUGH THE HISTORY OF CRYPTORCHIDISM AND TESTICULAR TUMORS

You have accessJournal of UrologyCME1 May 2022HF01-14 DESCENDING THROUGH THE HISTORY OF CRYPTORCHIDISM AND TESTICULAR TUMORS Alexis Steinmetz, Kit Yuen, David Diamond, and Ronald Rabinowitz Alexis SteinmetzAlexis Steinmetz More articles by this author , Kit YuenKit Yuen More articles by this author , David DiamondDavid Diamond More articles by this author , and Ronald RabinowitzRonald Rabinowitz More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002541.14AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: An appreciation for the association between aberrant testicular descent and testicular cancer has developed over the past two centuries. While the etiology is incompletely understood, cryptorchidism is a known risk factor for the development of testicular tumors—even in the contralateral descended testis. This report presents the history of the relationship between cryptorchidism and testis tumors. METHODS: The literature was reviewed for historical descriptions of cryptorchidism and testis tumors. RESULTS: While much of our understanding regarding testicular maldescent evolved over the last 200 years, cryptorchidism was described in the Mishnah, the 2nd century CE writing of Jewish oral law. Baron Albrecht von Haller identified the intra-abdominal location of the fetal testis in 1755. Seven years later, through postmortem dissection, John Hunter observed that testes descend during the 8th month of gestation. He also correctly hypothesized that testicles that failed to descend into the scrotum were intrinsically abnormal and that it was best to assist the testis in its passage. Surgical repair was attempted unsuccessfully in early 19th century Germany. James Adams and Thomas Curling are credited with the first orchidopexy on an infant in 1871 in London. Unfortunately, the patient developed a wound infection and died of sepsis. Using antiseptic technique, Thomas Annandale performed the first successful orchidopexy in Edinburgh in 1877. A growing appreciation of histological aberrations in the cryptorchid testis further supported the concept of surgical correction. In the US, Arthur Dean Bevan popularized the orchidopexy, reporting 400 orchidopexies with a 95% success rate in 1918. There were reports of carcinomas affecting undescended testes in the 1850s, and Max Schüller described their malignant potential in 1881. John Cunningham reported a testicular tumor following orchidopexy in 1921. Larger studies emerged by the 1940s documenting the increased incidence of testicular cancer in patients with cryptorchidism. It has since been established that approximately 10% of all germ cell tumors occur in maldescended testes. Early orchidopexy was initially believed to be beneficial by facilitating tumor detection, however more recent data have demonstrated that early repair reduces the risk of subsequent malignancy; histology worsens the longer the testis is undescended. The underlying mechanisms of increased tumorigenesis in this setting remain unclear. CONCLUSIONS: There is a rich history of the management of cryptorchidism and its relation to subsequent tumor formation. Source of Funding: N/A © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e216 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Alexis Steinmetz More articles by this author Kit Yuen More articles by this author David Diamond More articles by this author Ronald Rabinowitz More articles by this author Expand All Advertisement PDF DownloadLoading ...

Superior Longitudinal Fasciculus: A Review of the Anatomical Descriptions With Functional Correlates.

The superior longitudinal fasciculus (SLF) is part of the longitudinal association fiber system, which lays connections between the frontal lobe and other areas of the ipsilateral hemisphere. As a dominant association fiber bundle, it should correspond to a well-defined structure with a clear anatomical definition. However, this is not the case, and a lot of confusion and overlap surrounds this entity. In this review/opinion study, we survey relevant current literature on the topic and try to clarify the definition of SLF in each hemisphere. After a comparison of postmortem dissections and data obtained from diffusion MRI studies, we discuss the specifics of this bundle regarding its anatomical landmarks, differences in lateralization, as well as individual variability. We also discuss the confusion regarding the arcuate fasciculus in relation to the SLF. Finally, we recommend a nomenclature based on the findings exposed in this review and finalize with a discussion on relevant functional correlates of the structure.

Comparison Approach for Identifying Missed Invasive Fungal Infections in Formalin-Fixed, Paraffin-Embedded Autopsy Specimens.

Invasive fungal infection (IFI) has a high mortality rate in patients who undergo hematopoietic stem cell transplantation, and it is often confirmed by postmortem dissection. When IFI is initially confirmed after an autopsy, the tissue culture and frozen section are challenging to secure, and in many cases, formalin-fixed, paraffin-embedded (FFPE) samples represent the only modality for identifying fungi. Histopathological diagnosis is a useful method in combination with molecular biological methods that can achieve more precise identification with reproducibility. Meanwhile, polymerase chain reaction (PCR) using fungal-specific primers helps identify fungi from FFPE tissues. Autopsy FFPE specimens have a disadvantage regarding the quality of DNA extracted compared with that of specimens obtained via biopsy or surgery. In the case of mucormycosis diagnosed postmortem histologically, we examined currently available molecular biological methods such as PCR, immunohistochemistry (IHC), and in situ hybridization (ISH) to identify fungi. It is reasonable that PCR with some modification is valuable for identifying fungi in autopsy FFPE specimens. However, PCR does not always correctly identify fungi in autopsy FFPE tissues, and other approaches such as ISH or IHC are worth considering for clarifying the broad classification (such as the genus- or species-level classification).

Short-term pulsation of the jugular veins as a sign of a free blood clot in the left side of the heart

According to postmortem dissection, thrombosis of cardiac cavities is rarely diagnosed by clinicians (V.S. Smolensky and many others).

Dystocia in a wild Western Tiger Snake (Notechis scutatus occidentalis)

ABSTRACT Dystocia in reptiles is the retention of ova or foetuses within the female due to the failure of the female to complete parturition or oviposition. This disorder is commonly observed in captive reptiles, but has rarely been reported in wild reptiles. We observed a large internal obstruction in an adult female Tiger Snake captured as part of an ongoing population study. We failed to palpate out the object in the field, so we took the snake to a veterinary practice for professional assistance. All non-lethal methods of extracting the object were unsuccessful so we euthanised the specimen and post-mortem dissection revealed five mummified stillborn young lodged in a sealed reproductive tract. Reproductive abnormalities are frequent in Tiger Snakes and large proportions of litters can be comprised of unfertilised eggs, fertilised aborted eggs and stillborn young, yet none of these observations ever resulted in dystocia. It is interesting that this observation occurred in a snake from Herdsman Lake, Western Australia, where the Tiger Snake population is subjected to many anthropogenic stressors. We cannot determine what caused this case of dystocia but suspect it may have been caused by some sort of negative effect onset by the quality of the environment.

Changes in Blood Metabolites, Intestinal Microbiota Composition and Gene Expression of 95 Weeks Old Laying Hens Differing in Egg Production and Egg Breaking Strength.

Simple SummaryThe average cycle of laying hens is prolonged by improving one or more aspects, including genetics, nutrition, and management. Yet, this prolongation needs to go hand-in-hand with laying hens staying vital. Our objective was to explore hen vitality at an age of 95 weeks in association with performance parameters (egg production and breaking strength). To this end, we measured metabolism and disease indicators in blood, microbiota composition and diversity in different gut segments, and the biological activity of the small intestine. We observed that 12% of the hens developed certain aberrations. Additionally, five metabolites were significantly associated to these aberrations, and two metabolites to the performance parameters. In the small intestine we observed that in the production groups the physical barrier function was affected, whereas in the breaking strength group the immune function was affected. Taken together, these data show that hen vitality at later ages can still be improved and we provided data on a molecular level that could be used in future endeavors to improve animal health and welfare.Herein, we investigated to what extent molecular phenotypes of the systemic level (blood) and local (intestine) are associated with the performance of laying hens at 95 weeks of age. After the trial had run for 95 weeks, two performance groups were generated, i.e., egg production (PROD) and egg breaking strength (BS). A subset of 21 cages, 116 hens, was measured to indicate the metabolism and disease status. Additionally, a focus group (four cages) was made to perform molecular phenotyping in the intestine. A notifiable observation made during the post-mortem dissection was that approximately 12% of the birds at 95 weeks had developed certain aberrations and/or impairments (denoted as organ morbidity). At the systemic level, we observed five metabolites (γGT, triglycerides, HDL, glucose, and cholesterol) significantly associated to organ morbidity, and only two metabolites (urea and aspartate aminotransferase) to the performance phenotypes. At the local level, when comparing high PROD vs. low PROD, we observed differentially expressed genes involved in cell cycle processes and the extracellular matrix. When comparing high BS vs. low BS differentially, expressed genes were observed mainly involved in immune and cell cycle-related processes. This knowledge is crucial for developing novel strategies of keeping laying hens vital.

A pig model of tunneled dialysis catheter (TDC) infection and dysfunction: Opportunities for therapeutic innovation.

Although tunneled dialysis catheters (TDC) are far from ideal, they still represent the main form of vascular access for most patients beginning dialysis. Catheters are easy to place and allow patients instant access to dialysis, but regardless of these benefits, catheters are associated with a high incidence of significant complications like bloodstream infections, central venous stenosis, thrombosis, and dysfunction. In the present study, we aim to describe and characterize a swine model of catheter dysfunction and bloodstream infection, that recreates the clinical scenario, to help to serve as a platform to develop therapeutic innovations for this important clinical problem. Six Yorkshire cross pigs were used in this study. Non-coated commercial catheters were implanted in the external jugular recreating the main features of common clinical practice. Catheters were aseptically accessed twice a week for a mock dialysis procedure (flushing in and out) to assess for and identify catheter dysfunction. Animals were monitored daily for infections; once detected, blood samples were collected for bacterial culture and antibiograms. Study animals were euthanized when nonresponsive to treatment. Tissue samples were collected in a standardized fashion for macroscopic inspection and histological analysis. The data analysis revealed an early onset of infection with a median time to infection of 9 days, 40% of the isolates were polymicrobial, and the average time to euthanasia was 20.16 ± 7.3 days. Median time to catheter dysfunction onset was 6 days post-implantation. Postmortem dissection revealed external fibrin sheath and internal thrombosis as the main causes of catheter dysfunction. There was also evidence of central venous stenosis with positive cells for αSMA, CD68, Ki67, Smoothelin, and Vimentin within the venous neointima. The described model represents a reliable and reproducible large animal model of catheter dysfunction and bloodstream infection, which recreates all the main complications of TDC's and so could be used as a validated large animal model to develop new therapies for TDC related infection, thrombosis/dysfunction and central venous stenosis.

Post-mortem dissection of COVID-19: a pathogenic role for macrophages?

ACM is supported by a Medical Research Council Clinician Scientist Fellowship (MR/V006118/1). CDL is supported by a Wellcome Trust Clinical Research Career Development Fellowship (206566/Z/17/Z) and receives funding from the UKRI-NIHR COVID-19 Call (MR/V028790/1). PPV is supported by a Wellcome Trust PhD Training Fellowship for Clinicians (214179/Z/18/Z).

Anatomy and white-matter connections of the precuneus.

Purpose Advances in neuroimaging have provided an understanding of the precuneus'(PCu) involvement in functions such as visuospatial processing and cognition. While the PCu has been previously determined to be apart of a higher-order default mode network (DMN), recent studies suggest the presence of possible dissociations from this model in order to explain the diverse functions the PCu facilitates, such as in episodic memory. An improved structural model of the white-matter anatomy of the PCu can demonstrate its unique cerebral connections with adjacent regions which can provide additional clarity on its role in integrating information across higher-order cerebral networks like the DMN. Furthermore, this information can provide clinically actionable anatomic information that can support clinical decision making to improve neurologic outcomes such as during cerebral surgery. Here, we sought to derive the relationship between the precuneus and underlying major white-mater bundles by characterizing its macroscopic connectivity. Methods Structural tractography was performed on twenty healthy adult controls from the Human Connectome Project (HCP) utilizing previously demonstrated methodology. All precuneus connections were mapped in both cerebral hemispheres and inter-hemispheric differences in resultant tract volumes were compared with an unpaired, corrected Mann-Whitney U test and a laterality index(LI) was completed. Ten postmortem dissections were then performed to serve as ground truth by using a modified Klingler technique with careful preservation of relevant white matter bundles. Results The precuneus is a heterogenous cortical region with five major types of connections that were present bilaterally. (1) Short association fibers connect the gyri of the precuneus and connect the precuneus to the superior parietal lobule and the occipital cortex. (2) Four distinct parts of the cingulum bundle connect the precuneus to the frontal lobe and the temporal lobe. (3) The middle longitudinal fasciculus from the precuneus connects to the superior temporal gyrus and the dorsolateral temporal pole. (4) Parietopontine fibers travel as part of the corticopontine fibers to connect the precuneus to pontine regions. (5) An extensive commissural bundle connects the precuneus bilaterally. Conclusion We present a summary of the anatomic connections of the precuneus as part of an effort to understand the function of the precuneus and highlight key white-matter pathways to inform surgical decision-making. Our findings support recent models suggesting unique fiber connections integrating at the precuneus which may suggest finer subsystems of the DMN or unique networks, but further study is necessary to refine our model in greater quantitative detail.