Therapeutic Potential of PPARγ Activation in Stroke

Stroke (focal cerebral ischemia) is a leading cause of death and disability among adult population. Many pathological events including inflammation and oxidative stress during the acute period contributes to the secondary neuronal death leading the neurological dysfunction after stroke. Transcriptional regulation of genes that promote these pathophysiological mechanisms can be an effective strategy to minimize the poststroke neuronal death. Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors known to be upstream to many inflammatory and antioxidant genes. The goal of this review is to discuss the therapeutic potential and putative mechanisms of neuroprotection following PPAR activation after stroke

ANALYSIS OF BRAZILIAN SPLIT CYLINDER USING THE STATE BASED PERIDYNAMIC LATTICE MODEL

Concrete members deform discontinuously in the form of cracks and fracture. Continuum mechanics, which has dominated the field of solid mechanics over the years, does not handle such discontinuities. A material, as defined by continuum mechanics is that which is continuous and fills the space it occupies. Although this is a reasonable assumption for metals, it is an unrealistic notion for concrete. Stewart Silling invented peridynamics, which involves nonlocal solid modelling upon a continuous material space. Walter Gerstle developed a practical application of the peridynamic model for solid mechanics called the state-based peridynamic lattice model (SPLM). This approach involves material modelling with a finite number of interacting lattice particles rather than a continuum. The advantage of SPLM lies in its ease of computational implementation. SPLM is used in this thesis to analyze the very widely used Brazilian split cylinder test in estimating the uniaxial tensile strength of concrete. Additionally, the direct tension test and the modulus of rupture test are modelled to better understand the tensile strength of concrete and concrete behavior

Cementitious Sensors Exhibiting Stopbands in Acoustic Transmission Spectra

Ultrasonic monitoring in cementitious materials is challenging due to the high degree of attenuation. In wellbore environments, monitoring becomes more challenging due to inaccessibility. Meta materials, also known as acoustic bandgap materials, exhibit an interesting feature of forbidding the propagation of elastic/sound waves and isolate vibration in a certain frequency band. Traditionally, acoustic bandgap materials are developed with inclusions such as tin, aluminum, gold, steel in a polymer matrix. In this study, we present the development of three-dimensional cementitious sensors capable of exhibiting stopbands in the acoustic transmission spectra using carbon nanotubes. Relatively wide stopbands were engineered using Floquet-Bloch periodic conditions and computational simulations were conducted with cementitious matrix incorporating carbon nanotubes inclusions. The result of our investigations demonstrates, for the first time, the possibility of using cementitious sensors with wide acoustic stopbands in cementitious media. Based on the above simulations, a new sensor is designed and fabricated and the methods of making the sensor is presented. The new cementitious sensors are subjected to a frequency sweep and the transmission spectra is observed demonstrating the possible monitoring behavior of cement casing in wellbore service environments

Novel sperm-specific glycolytic isozymes generated by retrotransposition and alternative splicing

Targeted gene disruption of glycolytic enzymes expressed only during spermatogenesis indicates that glycolysis is essential for sperm motility and male fertility. This pathway is compartmentalized in the principal piece of the sperm flagellum, where several spermatogenic cell-specific isozymes are bound to a cytoskeletal structure known as the fibrous sheath. Fructose-1,6-bisphosphate aldolase, or aldolase, is the fourth enzyme in the glycolytic pathway. Genomic and proteomic analyses identified three aldolase A (Aldoa) transcripts generated by retrotransposition and alternative splicing: Aldoa_v2, Aldoart1, and Aldoart2. Unique nucleotide sequence in Aldoart1 provided evidence for an alternatively spliced exon in Aldoa_v2. Expression of all three isozymes was restricted to the male germline and was regulated at transcriptional and translational levels. Both ALDOART1 and ALDOA_V2 are tightly bound to the fibrous sheath and have unique N-terminal extensions that may mediate this binding. ALDOA_V2 is conserved across species and is expressed in rat and human sperm. Preliminary modeling data predicted unique amino acids near functional domains in each isozyme, suggesting distinctive binding and/or catalytic properties. Recombinant sperm ALDOA-related isozymes demonstrated reduced activity when expressed in E. coli, perhaps due to difficulties producing proteins with native conformations. However, analysis of aldolase kinetic parameters in mouse sperm identified a significant portion of the total activity in insoluble fractions, providing initial evidence that the novel ALDOA-related isozymes bound to the fibrous sheath are active. Glycolytic enzymes with restricted expression during spermatogenesis arose via gene duplication (Gapdhs) and retrotransposition (Pgk2, Aldoart1, Aldoart2). A genomic approach identified all retroposed sequences matching glycolytic enzymes in the human and mouse genomes. Each glycolytic enzyme is encoded by a family of genes, and there is frequent retrotransposition of a single gene in each family. The same orthologous gene is independently retroposed in both species. Results from this study identified an alternative form of Gpi1 transcribed during mouse spermatogenesis. Annotation and expression analysis of all glycolytic enzymes expressed during spermatogenesis will help to understand the regulation of energy metabolism. Since glycolysis is required for sperm motility and male fertility, spermatogenic-cell specific glycolytic enzymes are potential targets for contraceptives. Determining whether defects in the glycolytic pathway are a significant cause of male infertility is also an important clinical need

The promise of stem cell therapy for eye disorders

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A prospective trial of postoperative Lodoxamide (Alomide) on pterygium recurrence

Background: To compare pterygium recurrence after bare sclera excision with and without topical lodoxamide.Design: Randomised double-blind study.Methods: The study involved 61 patients with primary pterygia who had bare sclera excision after informed consent. They were post-operatively treated by either of 2 treatment groups for 4 weeks, with a 30-months follow-up: Controls/placebo = Guttae prednisolone 1% with chloramphenicol 0.5% plus guttae distilled water. Test group = Guttae prednisolone 1% with chloramphenicol 0.5% plus guttae lodoxamide 0.1%.Results: Sixty patients were analysed. Control Group had 20 females and 10 males, aged 28-69.5 years, mean 42.0(± 10.9). Test Group had 15 males and 15 females, aged 17-75 years, mean 46.0(±12.6). Recurrence for the Test Group was 11(37%) within 30 months and 11(37%) for the Control Group within 30 months (OR=1.00, CI: 0.35-2.858). Main complications encountered were granuloma: 7(11.7%) from the controls and 5(8.3%) from the test group; restriction in the motility of medial rectus muscle: 1(1.7%) from each group; persistent vascularisation at site of excision: 1(1.7%) from each group and adherence leukoma with uveitis 1(1.7%) from the control group, the latter also had persistent peripheral corneal epithelial defect later resulting in a dellen. No significant difference was found between the treatment groups with respect to recurrence, type and time of complications, orientation and morphology of pterygium, P>0.05.Conclusion: The recurrence of pterygium is high (about one third) with or without the use of adjuvant lodoxamide.Keywords: Pterygium, epidemiology, bare sclera, Lodoxamide (Alomide), recurrence

Rosai dorfman disease of the orbit

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Epidemiology and recurrence rate of pterygium post excision in Ghanaians

Objectives: To determine the epidemiology and recurrence rate of pterygium after excision using bare sclera techniqueDesign: Prospective non-comparative study.Setting: Ophthalmology unit, Korle-Bu Teaching Hospital, Accra, Ghana.Methods: The study involved 60 consecutive patients with primary apterygial from July 1998 to December 2000 who had bare sclera excision after informed consent. They were post-operatively followed up for 30-months.Results: Thirty-five patients (58%) were females. The patients' ages ranged from 17-75 years, mean (±12.6). Overall recurrence was 22(37%). The main complications encountered include were granuloma 20 %( n=12), restriction in medial rectus muscle motility 2(3%), persistent vascularisation at excision site 2(3%) and adherence leucoma with uveitis 1(2%). No significant association was found between recurrence and pterygium morphology, calcification, allergy and occupation (indoor or outdoor).Conclusion: The recurrence rate after pterygium excision using bare sclera technique in Ghanaians is high (37%).Keywords: Pterygium, epidemiology, bare sclera excision, recurrence, conjunctival growth