Computer assisted detection of polycystic ovary morphology in ultrasound images

Polycystic ovary syndrome (PCOS) is an endocrine abnormality with multiple diagnostic criteria due to its heterogenic manifestations. One of the diagnostic criterion includes analysis of ultrasound images of ovaries for the detection of number, size, and distribution of follicles within the ovary. This involves manual tracing of follicles on the ultrasound images to determine the presence of a polycystic ovary (PCO). A novel method that automates PCO morphology detection is described. Our algorithm involves automatic segmentation of follicles from ultrasound images, quantifying the attributes of the segmented follicles using stereology, storing follicle attributes as feature vectors, and finally classification of the feature vector into two categories. The classification categories are PCO morphology present and PCO morphology absent. An automatic PCO diagnostic tool would save considerable time spent on manual tracing of follicles and measuring the length and width of every follicle. Our procedure was able to achieve classification accuracy of 92.86% using a linear discriminant classifier. Our classifier will improve the rapidity and accuracy of PCOS diagnosis, and reduce the chance of the severe health implications that can arise from delayed diagnosis

Developing a neural implant to enable controlled alterations to brain architecture

Neuroscientific research frequently utilises loss of function experiments to attribute function to a brain region. Gain of function experiments via cortical re-wiring would aid in validation of these studies and could allow the repair of damaged neural circuitry or the creation of novel neural structures. Research into neuronal re-wiring within the central nervous system demonstrates insufficient neurite extension upon implantation and highlights the need for similarity between exogenous and endogenous neurons. An aligned poly-L-lactic acid (PLLA) nanofibre scaffold was developed that induced the three dimensional aggregation of primary cortical neurons into a physiological structure of clustered soma and aligned, fasciculated neurites in a controlled way. Due to the self-assembling and physiological architecture of these 3D structures and subsequent detection of electrophysiological activities, these 3D structures were classified as “organoids”. Cerebral cortical organoids generated using the nanofibre based methodology were demonstrated to be more developmentally advanced than their two-dimensional counterparts and mechanisms were elucidated for the aggregation of the neurons and the development that occurred post-aggregation. Analysis of gene expression suggested that the organoids were also undergoing advanced developmental processes and proposed a mechanism by which this occurs. Optogenetic depolarisation of the implanted neurons and detection of downstream electrophysiological activity was selected as the means of confirming integration of exogenous neurons into endogenous circuitry post-implantation. Methods were optimised to facilitate efficient viral transfection of the optogenetic protein (Channelrhodopsin-2). Aligned PLLA nanofibres were found to significantly enhance transfection rates relative to the 2D control and the process by which this occurs was investigated. The work presented within suggests that aligned PLLA nanofibres may be used to generate a cerebral cortical organoid that is suited to implantation and cortical re-wiring and may have additional in vitro applications within diverse fields such as high throughput pharmacology, computational neuroscience and bioengineering

Roles of P2X7 Receptors in Adipose and Skeletal Tissues of Mice

P2X7 is an ATP-gated ion channel in the plasma membrane of a number of cell types. Previous in vitro studies show that P2X7 plays a role in regulating the differentiation of osteoblasts and adipocytes from mesenchymal precursors, as well as cellular metabolism and energy homeostasis. Furthermore, P2X7 has been implicated in mediating the effects of mechanical stimuli in bone. Our objective was to investigate the roles of P2X7, mechanical vibration, and their possible interaction in regulating body composition in vivo. We developed a novel method to monitor body composition during growth and aging in mice using micro-computed tomography (Chapter 2). This method permits rapid and reproducible quantification of adipose, lean and skeletal tissues in a non-invasive manner. We then applied this methodology to monitor the body composition of wild-type and P2X7 knockout mice (Chapter 3). Loss of P2X7 function led to greater adiposity and ectopic lipid accumulation in older male mice. We next investigated the effects of low-magnitude, high-frequency vibration on wild-type and P2X7 knockout mice (Chapter 4). Under our conditions, vibration does not induce changes in body composition or bone microarchitecture. Together, our studies provide an effective tool for characterizing whole-body composition of mice and establish novel in vivo roles for the P2X7 receptor in regulating adipogenesis and lipid metabolism. Finally, our findings and those of others highlight the need to re-evaluate current thinking on the effects of low-magnitude, high-frequency vibration on body composition in vivo

Systems Radiology and Personalized Medicine

Medicine has evolved into a high level of specialization using the very detailed imaging of organs. This has impressively solved a multitude of acute health-related problems linked to single-organ diseases. Many diseases and pathophysiological processes, however, involve more than one organ. An organ-based approach is challenging when considering disease prevention and caring for elderly patients, or those with systemic chronic diseases or multiple co-morbidities. In addition, medical imaging provides more than a pretty picture. Much of the data are now revealed by quantitating algorithms with or without artificial intelligence. This Special Issue on “Systems Radiology and Personalized Medicine” includes reviews and original studies that show the strengths and weaknesses of structural and functional whole-body imaging for personalized medicine

Morphology of Mouse Anterior Cruciate Ligament-Complex Changes Following Exercise During Pubertal Growth

Postnatal development and the physiological loading response of the anterior cruciate ligament (ACL) complex (ACL proper, entheses, and bony morphology) is not well understood. We tested whether the ACL-complex of two inbred mouse strains that collectively encompass the musculoskeletal variation observed in humans would demonstrate significant morphological differences following voluntary cage-wheel running during puberty compared with normal cage activity controls. Female A/J and C57BL/6J (B6) 6-week-old mice were provided unrestricted access to a standard cage-wheel for 4 weeks. A/J-exercise mice showed a 6.3% narrower ACL (p-=-0.64), and a 20.1% more stenotic femoral notch (p-<-0.01) while B6-exercise mice showed a 12.3% wider ACL (p-=-0.10), compared with their respective controls. Additionally, A/J-exercise mice showed a 5.3% less steep posterior medial tibial slope (p-=-0.07) and an 8.8% less steep posterior lateral tibial slope (p-=-0.07), while B6-exercise mice showed a 9.8% more steep posterior medial tibial slope (p-<-0.01) than their respective controls. A/J-exercise mice also showed more reinforcement of the ACL tibial enthesis with a 20.4% larger area (p-<-0.01) of calcified fibrocartilage distributed at a 29.2% greater depth (p-=-0.02) within the tibial enthesis, compared with their controls. These outcomes suggest exercise during puberty significantly influences ACL-complex morphology and that inherent morphological differences between these mice, as observed in their less active genetically similar control groups, resulted in a divergent phenotypic outcome between mouse strains. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1910-1919, 2019Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151297/1/jor24328.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151297/2/jor24328_am.pd

Molecular imaging and immunotherapy in atherosclerotic cardiovascular disease

Atherosclerotic cardiovascular disease (ASCVD) is a disorder that affects both heart and blood vessels. It is caused by atherosclerosis, a chronic, low-grade inflammatory disease, which is characterized by the accumulation of lipids in the arterial wall. Modified lipoproteins contain pro-inflammatory epitopes, such as phosphorylcholine (PC), that interact with inflammatory cells in the vascular wall, thereby accelerating the development of atherosclerotic lesions. The main cause of myocardial infarction (MI) arises from a rupture of an unstable, inflamed atherosclerotic lesion in the coronary artery. The MI induces an intense inflammatory response that is essential for myocardial repair and scar formation, but which is also implicated in the onset of heart failure over time. Molecular imaging techniques can be potentially used for identification of new molecular targets, such as glucagon-like peptide-1 receptor (GLP-1R), that are involved in inflammatory and repair processes. The aim of this thesis was to investigate whether a novel immunotherapy targeting the PC epitope improves vascular function and attenuates atherosclerotic inflammation in mice. A positron emission tomography (PET) tracer 68Ga¬NODAGA-exendin-4 was evaluated for detection and imaging of GLP-1R expression after MI and in atherosclerosis in experimental models. In vivo PET imaging, ultrasound imaging, tissue autoradiography, immunohistological stainings, and cell assays were utilized as the main methods in the studies. This thesis showed that treatment with the PC immunotherapy preserved coronary artery function and attenuated the uptake of an established inflammation tracer, glucose analog 18F-FDG, in atherosclerotic lesions in mice. 68Ga-NODAGA¬exendin-4 PET detected up-regulated cardiac GLP-1R expression during the healing of MI in rats. The uptake of 68Ga-NODAGA-exendin-4 was also increased in inflamed atherosclerotic lesions in mice. In conclusion, PC immunotherapy might represent a potential approach to inhibit the lipid-driven inflammation in atherosclerosis. 68Ga-NODAGA-exendin-4 PET may have implications for studying pharmacological modification of GLP-1R signaling in ASCVD.Molekyylikuvantaminen ja immunoterapia ateroskleroottisissa sydän-ja verisuonitaudeissa Sydän-ja verisuonitautien yleisin syy on ateroskleroosi, mikä on krooninen matala-asteinen tulehduksellinen sairaus, jossa rasvaa kertyy valtimoiden seinämiin. Muokkautuneiden rasvapartikkelien pinnalta on tunnistettu tulehdusreaktiota edistäviä molekyylejä kuten fosforyylikoliini, jotka ovat osallisena valtimoplakkien muodostumiseen. Suurimman osan sydäninfarkteista aiheuttaa epävakaan tulehtuneen ateroskleroottisen plakin repeytyminen sepelvaltimossa. Sydäninfarkti saa aikaan tulehdusreaktion ja arpikudoksen muodostumisen sydänlihaksessa, mikä pitkittyneenä voi johtaa myös sydämen vajaatoimintaan. Molekyylikuvantamisen avulla voisi olla mahdollista tunnistaa ja tutkia uusia kohteita kuten glukagonin kaltainen peptidi-1 (GLP-1) -reseptori, jotka liittyvät sydäninfarktinjälkeiseen tulehdusreaktioon ja arven paranemiseen. Tämän väitöskirjan tarkoituksena oli tutkia koe-eläinmalleissa, miten uusi fosforyylikoliini-molekyyliin kohdentuva immunoterapia vaikuttaa ateroskleroottisten suonten toimintaan ja tulehdukseen. Lisäksi tutkittiin GLP-1-reseptorin ilmentymistä sydäninfarktin jälkeen ja ateroskleroottisissa plakeissa 68Ga¬NODAGA-exendin-4 merkkiaineen ja positroniemissiotomografia (PET)-kuvantamisen avulla. Tutkimusmenetelminä käytettiin in vivo PET-ja ultraäänikuvantamista, autoradiografiaa, kudosvärjäyksiä ja solukokeita. Väitöskirjassa havaittiin, että fosforyylikoliini-immunoterapian jälkeen hiirten sepelvaltimoiden toiminta oli parantunut ja plakkeihin kertyi vähemmän 18F-FDG¬merkkiainetta, mikä kertoo laantuneesta tulehduksesta. 68Ga-NODAGA-exendin-4 PET-kuvantaminen osoitti, että GLP-1-reseptorin ilmentyminen oli lisääntynyt infarktinjälkeisen tulehdusreaktion aikana. 68Ga-NODAGA-exendin-4-merkkiaine kertyi myös selvästi tulehtuneisiin ateroskleroottisiin plakkeihin. Yhteenvetona voidaan todeta, että fosforyylikoliini-immunoterapia saattaisi olla potentiaalinen uusi lääkehoito valtimoplakkien tulehdusreaktion hillitsemiseksi. 68Ga-NODAGA¬exendin-4 PET-kuvantamista voitaisiin hyödyntää GLP-1-reseptoriin kohdentuvien lääkehoitojen tutkimisessa ateroskleroottisissa sydän- ja verisuonitaudeissa

Is Quantitative Ultrasound a Valid Technique for Assessing Bone Quality in Deceased Infants?

There is no quantitative method for evaluating infant bone quality that is non-invasive, portable, brief in scan duration, and does not use ionizing radiation. This study investigates the relationship between components of infant bone quality and a measure of quantitative ultrasound (QUS), speed of sound (SOS), to provide insight into the validity of QUS as a diagnostic tool for evaluating infant bone quality. The study sample was comprised of 78 infants between the age of 30 weeks estimated gestational age and 12 postnatal months receiving an autopsy at the Harris County Institute of Forensic Sciences and Texas Children’s Hospital. Bone SOS measurements, costochondral rib and iliac crest samples, and radiographs of the forearm and leg were prospectively collected over a 9-month period. Demographic information, medical history, autopsy findings, and investigator reports were collected and used to identify chronic illness. Qualitative radiographic evaluation, bone mineral density (BMD), and tibial measurements were obtained from radiographs. Results indicated that SOS measures aspects of bone quality related to bone macrostructure. Prematurity and chronic illness were significantly associated in the current study sample and their detrimental effects could not be separated. Prematurity and, possibly, chronic illness significantly influenced SOS through their adverse effects on growth and bone health. BMD was not significantly associated with tibial or body size measurements, but this may have been due to the small area of bone used to estimate BMD. Although SOS and BMD were not significantly correlated, both showed a postnatal decline and subsequent increase at greater ages. Chronically ill infants had significantly lower BMD and greater qualitative radiographic evaluation scores than infants without chronic illness. Assessing bone quality is complex due to the multitude of factors which compose it. QUS remains a highly promising technology for evaluating infant bone quality, but it cannot be definitively concluded that QUS is a valid technique for evaluating infant bone quality based on this research alone. Research comparing SOS to finer-grained measurements of aspects of bone quality are necessary before the validity of QUS as a diagnostic tool for evaluating infant bone quality and strength can be determined

Regulation of inflammation in choroidal neovascularization in age related macular degeneration

La dégénérescence maculaire liée à l'âge (DMLA) est la cause la plus fréquente de déficience visuelle centrale irréversible chez les personnes de plus de 50 ans dans les pays industrialisés, avec des impacts sociétaux et financiers majeurs. La DMLA est une maladie à multiples facettes provoquée par des interactions entre les facteurs de risque et les antécédents génétiques et l'inflammation joue un rôle important. Les effets pro-inflammatoires provoquent une perturbation de l'environnement sousrétinien physiologiquement immunosuppresseur. L'accumulation de phagocytes mononucléaires (PM) dans l'espace sous-rétinien qui s'ensuit est au coeur de l'étiologie des formes atrophiques et humides de la DMLA. Après l’usage de tabac, l'obésité est l'un des facteurs de risque modifiables les plus importants. Nous avons démontré que les régimes riches en graisses exacerbent la néovascularisation choroïdienne (NVC) en modifiant le microbiote intestinal. La dysbiose intestinale entraîne une perméabilité intestinale accrue, une inflammation chronique de bas grade, une augmentation des PM sur le site de l'angiogenèse pathologique dans l'oeil et exacerbe finalement la NVC. La modification du microbiote peut réduire l'inflammation et atténuer la NVC et peut ainsi fournir des traitements peu intrusifs et rentables pour prévenir ou retarder la DMLA exsudative. Une autre option thérapeutique qui pourrait réduire la NVC par modulation inflammatoire consiste à piéger localement les ligands de NRP1 avec un piège dérivé de NRP1. Les ligands de NRP1 sont élevés dans le vitré des patients atteints de DMLA. Nous avons constaté que les PM exprimant NRP1 favorisaient la NVC en atténuant la production de facteurs inflammatoires et en favorisant l'activation alternative, donnant aux PM un caractère pro-angiogénique. Les PM moins inflammatoires et plus de type M2 qui sont enrichis avec l'âge et exacerbent la NVC peuvent être modulés et devenir moins nuisibles en empêchant l'activation de NRP1. Cette thèse explore deux angles dans lesquels la régulation de l'inflammation peut influencer la formation de NVC et jette les bases du développement futur de nouveaux traitements préventifs primaires et secondaires efficaces dans le contexte de la DMLA.Age related macular degeneration (AMD) is the most common cause of irreversible central vision impairment in people over 50 in industrialized countries, with major societal and financial impacts. AMD is a multifaceted disease provoked by interactions among environmental risk factors and genetic backgrounds in which inflammation plays an important role. Proinflammatory effects cause a disruption of the physiologically immunosuppressive subretinal environment. The ensuing accumulation of mononuclear phagocytes in the subretinal space is central to the etiology of both atrophic and wet forms of AMD. After smoking, obesity is one of the most important modifiable risk factors. We demonstrate that high-fat diets exacerbate choroidal neovascularisation (CNV) by altering gut microbiota. Gut dysbiosis leads to heightened intestinal permeability and chronic low-grade inflammation, increases recruitment of microglia and macrophages to the site of pathological angiogenesis in the eye and ultimately exacerbates CNV. Modifying microbiota can reduce systemic and local choroidal inflammation and attenuate pathological neovascularization and may thus provide minimally intrusive and cost-effective paradigms to prevent or delay exudative AMD. Another therapeutic option that could reduce CNV through inflammatory modulation is locally trapping ligands of NRP1 with a NRP1-derived trap. Ligands for NRP1 are elevated in the vitreous of patients with AMD at times of active CNV. We found that NRP1-expressing MPs promote CNV by mitigating production of inflammatory factors and promoting alternative activation, giving the MPs a pro-angiogenic character. The less inflammatory and more M2-like MPs that are enriched with age and exacerbate CNV can be rendered less detrimental by hindering NRP1 activation. This thesis explores two angles wherein regulation of inflammation can influence the formation of CNV and lays the groundwork for future development of novel effective primary and secondary preventive treatments for AMD

Inhibition of vascular adhesion protein-1 modifies hepatic steatosis in vitro and in vivo

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is associated with obesity, insulin resistance and dyslipidaemia and currently is estimated to affect up to a third of all individuals in developed countries. Current standard of care for patients varies according to disease stage, but includes lifestyle interventions common insulin sensitizers, antioxidants and lipid modifiers. However, to date specific therapies have shown little histological or fibrosis stage improvement in large clinical trials, and there is still no licensed therapy for NAFLD. Given the high prevalence, limited treatment options and significant screening costs for the general population, new treatments are urgently required. AIM: To assess the potential for inhibition of the amine oxidase enzyme vascular adhesion protein-1 (VAP-1) to modify hepatic lipid accumulation in NAFLD. METHODS: We have used immunochemical and qPCR analysis to document expression of VAP-1 and key functional proteins and transporters across the NAFLD spectrum. We then utilised hepatocytes in culture and human precision cut liver slices in concert with selective enzyme activity inhibitors to test the effects of activating the semicarbazide-sensitive amine oxidase activity of VAP-1 on hepatic lipid uptake and triglyceride export. A murine model of NAFLD was also used to determine the consequences of VAP-1 knockout and gene expression arrays were used to quantify the effects of VAP-1 activity on key lipid modifying and proinflammatory gene expression. RESULTS: We confirmed that increasing severity of NAFLD and progression to cirrhosis was associated with a significant increase in hepatocellular VAP-1 expression. Hepatocytes in vitro exposed to recombinant VAP-1 and its substrate methylamine showed increased lipid accumulation as determined by quantification of Oil Red O uptake. This was recapitulated using hydrogen peroxide, and lipid accumulation was accompanied by changes in expression of the lipid transporter molecules FABP3, FATP6, insulin receptor subunits and PPARα. Human liver tissue exposed to recombinant VAP-1 or substrates for endo/exogenous VAP-1 produced less triglyceride than untreated tissue and demonstrated an increase in steatosis. This response could be inhibited by using bromoethylamine to inhibit the SSAO activity of VAP-1, and mice deficient in VAP-1/AOC3 also demonstrated reduced steatosis on high fat diet. Exposure of human liver tissue to methylamine to activate VAP-1 resulted in increased expression of FABP2 and 4, FATP3-5, caveolin-1, VLDLR, PPARGC1 and genes associated with the inflammatory response. CONCLUSION: Our data confirm that the elevations in hepatic VAP-1 expression reported in nonalcoholic steatohepatitis can contribute to steatosis, metabolic disturbance and inflammation. This suggests that targeting the semicarbazide sensitive amine oxidase capacity of VAP-1 may represent a useful adjunct to other therapeutic strategies in NAFLD