388 research outputs found
Two models of experimental myopia in the mouse
AbstractPurposeThe purpose of this study was to test the response of the mouse eye to two methods for the induction of experimental myopia.MethodsGrowth patterns of eyes were determined by axial length measurements from birth to adult in eyes of both sexes of normal mice examined on post-natal day 1 to 6 months and at 1 year. For the induction of experimental myopia, Balb/cJ mice were prepared with either unilateral lid suture or by a −10D spectacle lens placed over one eye at post-natal day 10. Other mice received a plano lens as a control for lens wear. Refraction was carried out at post-natal days of 28, 42 and 56 in lid suture and spectacle lens wear group by streak retinoscopy. Axial length was measured by a combination of video image photography, digital caliper, or Optical Low Coherence Interferometry (OLCI). Corroborative optical modeling of the mouse eye was carried out using ZEMAX ray tracing software.ResultsAxial length (AL) increased linearly between post-natal day 1 to day 56, plateauing at about 140 days. After 18 days of unilateral lid suture initiated 10 days after birth, the AL of experimental eyes was 3.032±0.003mm, while AL in contra-lateral control eyes was 2.981±0.005mm (mean±sem, p<0.05, n=40), after 32 days, the AL of experimental eyes was 3.290±0.004mm, and the AL of control eyes was 3.104±0.002mm (p<0.001, n=60). After 46 days of lid closure AL of experimental eyes was 3.592±0.003mm, while AL of control eyes was 3.363±0.003mm (p<0.001, n=80). Spectacle lens wear of 46 days duration increased AL in experimental eyes to 3.721±0.002mm, while AL in control eyes was 3.354±0.003mm (p<0.001, n=100). Refraction and ray tracing analysis substantiated the dimensional changes to be consistent with increased AL.ConclusionsTwo procedures to induce experimental myopia, initiated at eye opening, produced significant myopic shifts corresponding to increases in axial lengths after 32 and 46 days of lid suture and after 46 days wearing a −10D spectacle lens
The Effect of Distal Core Flattening and Heat Treatment on 304 Stainless Steel Guide Wires
The mechanical response of 304 stainless steel guide wires due to different temper conditions and amounts of flattening is to be explored in this project. For this specific project, there is no public literature on the mechanical properties of guide wires with the above conditions through tensile testing or Turns to Failure Testing. To address this, the project with Abbott Vascular will measure the mechanical properties of guide wires using the aforementioned factors. Due to a lack of previous literature on this research topic, there are no quantitative goals for the project, however, any new research compiled in this area will be beneficial. As a result of the COVID-19 pandemic, current limitations to lab access prevent new data from being collected on guide wires, so this report will mainly focus on existing data from wire manufacturers. Available tensile properties of 304 stainless steel at varying cold work levels will be taken into account to better understand guide wire behavior and allow us to suggest the next steps in order to progress this project in the future
Possible Influence of δ-Aminolevulinic Acid Dehydratase Polymorphism and Susceptibility to Renal Toxicity of Lead: A Study of a Vietnamese Population
We examined six newly identified polymorphisms in the δ-aminolevulinic acid dehydratase (ALAD) single-nucleotide polymorphisms (SNPs) to determine if these SNPs could modify the relationship between blood lead (PbB) and some renal parameters. This is a cross-sectional study of 276 lead-exposed workers in Vietnam. All workers were measured for PbB, urinary retinol-binding protein (URBP), urinary α(1)-microglobulin (Uα1m), urinary β(2)-microglobulin (Uβ2m), urinary N-acetyl-β-d-glucosaminidase (NAG), urinary aminolevulinic acid (ALAU), serum α(1)-microglobulin (Sα1m), serum β(2)-microglobulin (Sβ2m), and urinary albumin (Ualb). The six SNPs were Msp and Rsa in exon 4, Rsa39488 in exon 5, HpyIV and HpyCH4 in intron 6, and Sau3A in intron 12. Analysis of covariance (ANCOVA) with interaction of PbB × SNPs were applied to examine modifying effect of the SNPs on the association of renal parameters and PbB, adjusting for potential confounders of age, gender, body mass index, and exposure duration. HpyCH4 was found to be associated with certain renal parameters. For HpyCH4 1-1, an increase of 1 μg/dL PbB caused an increase of 1.042 mg/g creatinine (Cr) Uα1m, 1.069 mg/g Cr Uβ2m, 1.038 mg/g Cr URBP, and 1.033 mg/g Cr Ualb, whereas in HpyCH4 1-2, an increase of 1 μg/dL PbB resulted in an increase of only 1.009 mg/g Cr Uα1m, 1.012 mg/g Cr Uβ2m, 1.009 mg/g Cr URBP, and 1.007 mg/g Cr Ualb. HpyCH4 SNP appeared to modify the lead toxicity to kidney with wild-type allele being more susceptible than variants. The mechanism for this effect is not clear. Further studies are needed to confirm this observation
Incremental cost-effectiveness analysis of gestational diabetes mellitus screening strategies in Singapore
10.1177/1010539515612908Asia-Pacific Journal of Public Health28115-25GUSTO (Growing up towards Healthy Outcomes
A study on the differential protein profiles in liver cells of heat stress rats with and without turpentine treatment
<p>Abstract</p> <p>Background</p> <p>Heat stress (HS) and related illnesses are a major concern in military, sports, and fire brigadiers. HS results in physiologic responses of increased temperature, heart rate and sweating. In heat stroke, inflammatory response plays an important role and it is evidenced that turpentine (T) induced circulating inflammatory cytokines reduced survival rate and duration at 42°C. Here we report the alteration in the protein expression in liver cells upon HS with and without T treatment using two dimensional gel electrophoresis (2-DE), tryptic in-gel digestion and MALDI-TOF-MS/MS approaches</p> <p>Results</p> <p>The effects of HS and T treatments alone and a combined treatments (T+HS) was performed in Wistar rat models. Proteomic analysis of liver in the HS and T+HS groups were analyzed compared to liver profiles of resting control and T treated groups. The study revealed a total of 25 and 29 differentially expressed proteins in the HS and T+HS groups respectively compared to resting control group. Fourteen proteins showed altered expression upon T treatment compared to resting control group. Proteins that are involved in metabolic and signal transduction pathways, defense, redox regulation, and cytoskeletal restructuring functions were identified. The altered expression of proteins reflected in 2D gels were corroborated by quantitative real time RT-PCR analysis of 8 protein coding genes representing metabolic and regulatory pathways for their expression and normalized with the house keeping gene β-actin</p> <p>Conclusion</p> <p>The present study has identified a number of differentially expressed proteins in the liver cells of rats subjected to T, HS and T+HS treatments. Most of these proteins are implicated in cell metabolism, as well as adaptive response to incurred oxidative stress and tissue damage due to T+HS and HS effects.</p
Deposition of copper by plasma-enhanced atomic layer deposition using a novel N-Heterocyclic carbene precursor
Two novel N-heterocyclic carbene (NHC)-containing copper(I) amides are reported as atomic layer deposition (ALD) precursors. 1,3-Diisopropyl-imidazolin-2-ylidene copper hexamethyldisilazide (1) and 4,5-dimethyl-1,3-diisopropyl-imidazol-2-ylidene copper hexamethyldisilazide (2) were synthesized and structurally characterized. The thermal behavior of both compounds was studied by thermogravimetric analysis (TGA), and they were both found to be reasonably volatile compounds. Compound 1 had no residual mass in the TGA and showed long-term stability at temperatures as high as 130 °C, while 2 had a residual mass of 7.4%. Copper metal with good resistivity was deposited using 1 by plasma-enhanced atomic layer deposition. The precursor demonstrated self-limiting behavior indicative of ALD, and gave a growth rate of 0.2 Å/cycle. Compound 2 was unsuccessful as an ALD precursor under similar conditions. Density functional theory calculations showed that both compounds adsorb dissociatively onto a growing copper film as long as there is some atomic roughness, via cleavage of the Cu-carbene bond
Impact of exercise on innate immunity in multiple sclerosis progression and symptomatology
Multiple Sclerosis (MS), an idiopathic progressive immune-mediated neurological disorder of the central nervous system (CNS), is characterized by recurrent episodes of inflammatory demyelination and consequent axonal deterioration. It accounts for functional deterioration and lasting disability among young adults. A body of literature demonstrates that physical activity counteracts fatigue and depression and may improve overall quality of life in MS patients. Furthermore, much data indicates that exercise ameliorates chronic neuroinflammation and its related pathologies by tipping cytokine profiles toward an anti-inflammatory signature. Recent data has focused on the direct impact of exercise training on the innate immune system by targeting toll-like receptors (TLRs), signaling pattern recognition receptors that govern the innate immune response, shedding light on the physiological role of TLRs in health and disease. Indeed, TLRs continue to emerge as players in the neuroinflammatory processes underpinning MS. This review will highlight evidence that physical activity and exercise are potential immunomodulatory therapies, targeting innate signaling mechanism(s) to modulate MS symptom development and progression
Risk association, linkage disequilibrium, and haplotype analyses of ß-like globin gene polymorphisms with malaria risk in the Sabah population of Malaysian Borneo
Single nucleotide polymorphisms (SNPs) in the β-like globin gene of the human hosts to the risk of malaria are unclear. Therefore, this study investigates these associations in the Sabah population, with a high incidence of malaria cases. In brief, DNA was extracted from 188 post-diagnostic blood samples infected with Plasmodium parasites and 170 healthy controls without a history of malaria. Genotyping of the β-like globin C-158T, G79A, C16G, and C-551T SNPs was performed using a polymerase chain reaction-restriction fragment length polymorphism approach. Risk association, linkage disequilibrium (LD), and haplotype analyses of these SNPs were assessed. This study found that the variant allele in the C-158T and C16G SNPs were protective against malaria infections by 0.5-fold, while the variant allele in the G79A SNP had a 6-fold increased risk of malaria infection. No SNP combination was in perfect LD, but several haplotypes (CGCC, CGCT, and CGGC) were identified to link with different correlation levels of malaria risk in the population. In conclusion, the C-158T, G79A, and C16G SNPs in the β-like globin gene are associated with the risk of malaria. The haplotypes (CGCC, CGCT, and CGGC) identified in this study could serve as biomarkers to estimate malaria risk in the population. This study provides essential data for the design of malaria control and management strategies
Pulse wave velocity is associated with increased plasma oxLDL in ageing but not with FGF21 and habitual exercise
Fibroblast
growth factor 21 (FGF21) and adiponectin increase expression of genes involved
in antioxidant pathways, but their roles in mediating oxidative stress and
arterial stiffness with ageing and habitual exercise remain unknown. We explored
the role of the FGF21–adiponectin axis in mediating oxidative stress and
arterial stiffness with ageing and habitual exercise. Eighty age- and sex-matched healthy individuals
were assigned to younger
sedentary or active (18–36 years old,n=20
each) and older sedentary or active (45–80 years old,n=20 each) groups. Arterial stiffness was measured indirectly using
pulse wave velocity (PWV). Fasted plasma concentrations of FGF21, adiponectin
and oxidized low-density lipoprotein (oxLDL) were measured. PWV was 0.2-fold
higher and oxLDL concentration was 25.6% higher (both p<0.001) in older than younger adults, despite no difference in
FGF21 concentration (p=0.097) between
age groups. PWV (p=0.09) and oxLDL concentration (p=0.275) did not differ between activity groups but FGF21 concentration was
9% lower in active than sedentary individuals (p=0.011). Adiponectin concentration did not differ by age (p=0.642) or exercise habits (p=0.821). In conclusion, age, but not
habitual exercise, was associated with higher oxidative stress and arterial
stiffness. FGF21 and adiponectin did not differ between younger and older
adults, unlikely mediating oxidative stress and arterial stiffness in healthy
adults. <br
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