Formulation and In-Vitro Evaluation of Metoprolol Tartrate Microspheres by using Natural Semisynthetic and Synthetic Polymers as Controlled Release Dosage Form

The goal of a controlled release dosage form is to maintain therapeutic blood or tissue levels of the drug for an extended and specified period of time. This is generally accomplished by attempting to obtain "zero-order" release from the dosage form. Zero-order release constitutes drug release from the dosage form which is independent of the amount of drug in the delivery system (i.e. a constant release rate). Sustained-release systems generally do not attain this type of release and usually try to mimic zero-order release by providing drug in a slow first-order fashion (i.e., concentration release dependent). Systems that are designated as prolonged release can also be considered as attempts at achieving sustained-release delivery. Based on all the above evaluation parameters it was concluded that the formulation F3 was found to be best formulation among the formulations from F1 to F9. The in-vitro drug released data was applied to various kinetic models such as zero order kinetics, Higuchi plot, first order kinetics and Peppas plot by predict the drug release kinetics mechanism. The formulation F3 was best fitted with Matrix kinetics and it undergoes Quasi-fickian diffusion mechanism (n<0.5). According to stability study it was found that there was no variation in Percentage yield, Entrapment efficiency, and In-vitro drug released profile of optimized formulation F3 for 3 months period

Active invasion of Porphyromonas gingivalis and infection-induced complement activation in ApoE-/- mice brains

Periodontal disease is a polymicrobial inflammatory disease that leads to chronic systemic inflammation and direct infiltration of bacteria/bacterial components, which may contribute to the development of Alzheimer’s disease. ApoE-/- mice were orally infected (N = 12) with Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia and Fusobacterium nucleatum as mono- and polymicrobial infections. ApoE-/- mice were sacrificed following 12 and 24 weeks of chronic infection. Bacterial genomic DNA was isolated from all brain tissues except for the F. nucleatum mono-infected group. Polymerase chain reaction was performed using universal 16s rDNA primers and species- specific primer sets for each organism to determine whether the infecting pathogens accessed the brain. Sequencing amplification products confirmed the invasion of bacteria into the brain during infection. The innate immune responses were detected using antibodies against complement activation products of C3 convertase stage and the membrane attack complex. Molecular methods demonstrated that 6 out of 12 ApoE-/- mice brains contained P. gingivalis genomic DNA at 12 weeks (P = 0.006), and 9 out of 12 at 24 weeks of infection (P = 0.0001). Microglia in both infected and control groups demonstrated strong intracellular labeling with C3 and C9, due to on-going biosynthesis. Tthe pyramidal neurons of the hippocampus in 4 out of 12 infected mice brains demonstrated characteristic opsonization with C3 activation fragments (P = 0.032). These results show that the oral pathogen P. gingivalis was able to access the ApoE-/- mice brain and thereby contributed to complement activation with bystander neuronal injury

Porphyromonas gingivalis is a Strong Risk Factor for Alzheimer’s Disease

Porphyromonas gingivalis (P. gingivalis) is one of the several important bacterial pathogens associated with the sporadic Alzheimer’s disease (AD). Different serotypes are either capsulated or are non-capsulated. It has been demonstrated that P. gingivalis (non-capsulated) can reproduce the neurodegenerative AD-like changes in vitro, and a capsular P. gingivalis (strain W83) could reproduce the cardinal hallmark lesions of AD in a wild-type mouse model. All P. gingivalis forms express proteolytically active proteases that enable cleavage of the amyloid precursor protein (APP) and tau resulting in the formation of amyloid-beta and neurofibrillary tangles (NFTs). Tau is an established substrate for gingipains, which can cleave tau into various peptides. Some of the P. gingivalis fragmented tau protein peptides contain “VQIINK” and “VQIVYK” hexapeptide motifs which map to the flanking regions of the microtubule binding domains and are also found in paired helical filaments that form NFTs. P. gingivalis can induce peripheral inflammation in periodontitis and can also initiate signaling pathways that activate kinases, which in turn, phosphorylate neuronal tau. Periodontal disease related inflammation has metabolic implications for an individual’s peripheral and brain health as patients suffering from generalized periodontitis often have related co-morbidities and are “at risk” of developing AD. The aim here is to discuss the role of P. gingivalis behind such associations with the backdrop of huge efforts to test P. gingivalis virulence factors clinically (GAIN Trial: Phase 2/3 Study of COR388 in Subjects with AD) with inhibitors, which may lead to an intervention by reducing the pathogenic bacterial load

Molecular Determinants That Regulate Plasma Membrane-Specific Binding of HIV-1 Structural Protein Gag.

Human Immunodeficiency Virus type 1 (HIV-1) assembly is a multistep process mediated by the viral precursor polyprotein Gag (Pr55Gag). Matrix (MA), which constitutes the N-terminal domain of Pr55Gag, is essential for membrane binding and targeting of Gag to the plasma membrane (PM). MA has a bipartite signal for membrane binding: a myristate moiety at the N-terminus and amino acid residues 17-31 that form a highly basic region (HBR) on the surface of MA. The N-terminal myristate is normally sequestered into the MA globular domain, and a structural change exposes myristate, thereby enhancing membrane binding. The HBR on the other hand is thought to bind acidic lipids. Previous results from the lab suggest that a PM-specific acidic lipid, phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P2], is important for Gag localization to the PM. In this thesis, I have shown that Gag interacts specifically with PI(4,5)P2 and that this interaction is important for efficient membrane binding of Gag. To elucidate the molecular mechanisms by which Gag-PI(4,5)P2 interaction is regulated, site-directed mutagenesis was performed on the MA HBR. Using this approach, we identified three lysines that facilitate membrane binding by interacting with PI(4,5)P2. Strikingly, mutations in two other lysines in the MA HBR enhance PI(4,5)P2-independent membrane binding by exposing myristate. Thus, MA HBR has opposing roles in membrane binding. Notably, another major finding of this thesis is that RNA also negatively regulates membrane binding of Gag. In the absence but not in the presence of PI(4,5)P2, RNA bound to the MA HBR abolishes membrane binding of Gag. Overall, the results from this thesis suggest that the MA HBR regulates membrane binding both positively by binding to PI(4,5)P2 and negatively through myristate sequestration and RNA binding. This regulation ensures that Gag is targeted specifically to the PM, where it likely interacts with other viral and cellular molecules for efficient virus assembly and release.Ph.D.Microbiology & ImmunologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/86369/1/vineelac_1.pd

CAPD: A Context-Aware, Policy-Driven Framework for Secure and Resilient IoBT Operations

The Internet of Battlefield Things (IoBT) will advance the operational effectiveness of infantry units. However, this requires autonomous assets such as sensors, drones, combat equipment, and uncrewed vehicles to collaborate, securely share information, and be resilient to adversary attacks in contested multi-domain operations. CAPD addresses this problem by providing a context-aware, policy-driven framework supporting data and knowledge exchange among autonomous entities in a battlespace. We propose an IoBT ontology that facilitates controlled information sharing to enable semantic interoperability between systems. Its key contributions include providing a knowledge graph with a shared semantic schema, integration with background knowledge, efficient mechanisms for enforcing data consistency and drawing inferences, and supporting attribute-based access control. The sensors in the IoBT provide data that create populated knowledge graphs based on the ontology. This paper describes using CAPD to detect and mitigate adversary actions. CAPD enables situational awareness using reasoning over the sensed data and SPARQL queries. For example, adversaries can cause sensor failure or hijacking and disrupt the tactical networks to degrade video surveillance. In such instances, CAPD uses an ontology-based reasoner to see how alternative approaches can still support the mission. Depending on bandwidth availability, the reasoner initiates the creation of a reduced frame rate grayscale video by active transcoding or transmits only still images. This ability to reason over the mission sensed environment and attack context permits the autonomous IoBT system to exhibit resilience in contested conditions

Enhancing Medical Image Segmentation: Optimizing Cross-Entropy Weights and Post-Processing with Autoencoders

The task of medical image segmentation presents unique challenges, necessitating both localized and holistic semantic understanding to accurately delineate areas of interest, such as critical tissues or aberrant features. This complexity is heightened in medical image segmentation due to the high degree of inter-class similarities, intra-class variations, and possible image obfuscation. The segmentation task further diversifies when considering the study of histopathology slides for autoimmune diseases like dermatomyositis. The analysis of cell inflammation and interaction in these cases has been less studied due to constraints in data acquisition pipelines. Despite the progressive strides in medical science, we lack a comprehensive collection of autoimmune diseases. As autoimmune diseases globally escalate in prevalence and exhibit associations with COVID-19, their study becomes increasingly essential. While there is existing research that integrates artificial intelligence in the analysis of various autoimmune diseases, the exploration of dermatomyositis remains relatively underrepresented. In this paper, we present a deep-learning approach tailored for Medical image segmentation. Our proposed method outperforms the current state-of-the-art techniques by an average of 12.26% for U-Net and 12.04% for U-Net++ across the ResNet family of encoders on the dermatomyositis dataset. Furthermore, we probe the importance of optimizing loss function weights and benchmark our methodology on three challenging medical image segmentation tasksComment: Accepted at ICCV CVAMD 202

Cerebral oxidative stress and microvasculature defects in TNF-α expressing transgenic and Porphyromonas gingivalis-infected ApoE-/- mice

The polymicrobial dysbiotic subgingival biofilm microbes associated with periodontal disease appear to contribute to developing pathologies in distal body sites, including the brain. This study examined oxidative stress, in the form of increased protein carbonylation and oxidative protein damage, in the tumour necrosis factor-α (TNF-α) transgenic mouse that models inflammatory TNF-α excess during bacterial infection; and in the apolipoprotein knockout (ApoE-/-) mouse brains, following Porphyromonas gingivalis gingival monoinfection. Following 2,4-dinitrophenylhydrazine derivatization, carbonyl groups were detected in frontal lobe brain tissue lysates by immunoblotting and immunohistochemical analysis of fixed tissue sections from the frontotemporal lobe and the hippocampus. Immunoblot analysis confirmed the presence of variable carbonyl content and oxidative protein damage in all lysates, with TNF-α transgenic blots exhibiting increased protein carbonyl content, with consistently prominent bands at 25 kDa (p = 0.0001), 43 kDa and 68 kDa, over wild-type mice. Compared to sham-infected ApoE-/- mouse blots, P. gingivalis-infected brain tissue blots demonstrated the greatest detectable protein carbonyl content overall, with numerous prominent bands at 25 kDa (p = 0.001) and 43 kDa (p = 0.0001) and an exclusive band to this group between 30-43 kDa* (p = 0.0001). In addition, marked immunostaining was detected exclusively in the microvasculature in P. gingivalis-infected hippocampal tissue sections, compared to sham-infected, wild-type and TNF-α transgenic mice. This study revealed that the hippocampal microvascular structure of P. gingivalis-infected ApoE-/- mice possesses elevated oxidative stress levels, resulting in the associated tight junction proteins being susceptible to increased oxidative/proteolytic degradation, leading to a loss of functional integrity

Apolipoprotein E related Co-Morbidities and Alzheimer’s disease

The primary goal of advancement in clinical services is to provide a health care system that enhances an individual’s quality of life. Incidence of diabetes mellitus, cardiovascular disease and associated dementia coupled with the advancing age of the population, have led to an increase in the worldwide challenge to the healthcare system. In order to overcome these challenges prior knowledge of common, reliable risk factors and their effectors is essential. The oral health constitutes one such relatively unexplored but indispensable risk factor for aforementioned co-morbidities, in the form of poor oral hygiene and tooth loss during aging. Behavioural traits such as low education, smoking, poor diet, neglect of oral health, lack of exercise, and hypertension are few of the risk factors that are shared commonly amongst these conditions. In addition, common genetic susceptibility traits such as the apolipoprotein ɛ gene, together with an individual’s life style can also influence the development of co-morbidities such as periodontitis, atherosclerosis/stroke, diabetes, and Alzheimer’s disease. This review specifically addresses the susceptibility of apolipoprotein ε gene allele 4 as the plausible commonality for the etiology of co-morbidities that eventually result from periodontal diseases and ultimately progress to dementia

Chronic Porphyromonas gingivalis infection accelerates the occurrence of age-related granules in ApoE-/- mice brains

This study explored the origin of age-related granules in the apolipoprotein E gene knockout (ApoE−/−) B6 background mice brains following chronic gingival infection with Porphyromonas gingivalis for 24 weeks. Intracerebral localization of P. gingivalis was detected by fluorescence in situ hybridization (FISH) and its protease by immunohistochemistry. The age-related granules were observed by periodic acid–Schiff (PAS), silver impregnation, and immunostaining. FISH showed intracerebral dissemination of P. gingivalis cells (p = 0.001). PAS and silver impregnation demonstrated the presence of larger inclusions restricted to the CA1, CA2, and dentate gyrus sectors of the hippocampus. A specific monoclonal antibody to bacterial peptidoglycan detected clusters of granules with variable sizes in mice brains infected with P. gingivalis (p = 0.004), and also highlighted areas of diffuse punctate staining equating to physical tissue damage. Mouse immunoglobulin G was observed in the capillaries of the cerebral parenchyma of all P. gingivalis–infected brains (p = 0.001), and on pyramidal neurons in some severely affected mice, compared with the sham-infected mice. Gingipains was also observed in microvessels of the hippocampus in the infected mice. This study supports the possibility of early appearance of age-related granules in ApoE−/− mice following inflammation-mediated tissue injury, accompanied by loss of cerebral blood-brain barrier integrity