336 research outputs found
Structural aberrations in fluorosed human teeth: Biochemical and scanning electron microscopic studies
The present investigation was carried out to provide biochemical and ultrastructural evidences on the aberrations that appear in teeth in human Dental Fluorosis (DF), a condition caused by excess intake of fluoride. Human fluorosed teeth were obtained from the OPD of Madras Dental College, Chennai. Normal tooth samples were also collected from patients who opted for denture. The samples were investigated for fluoride and calcium contents, besides the tooth surfaces were examined under scanning electron microscope to assess the morphological aberrations. An increase in fluoride content and decrease in calcium content in fluorosed human teeth were observed when compared to the control. The scanning electron micrographs of the enamel surface of fluorosed human teeth show pitted, uneven and rough surfaces. Cracks and fissures were also observed on the enamel surface of fluorosed teeth. The present study provides evidence to suggest that pitting, perforation and structural alterations in DF are the result of impaired enamel mineralization
Radiation Induced Xerostomia: Current Concepts and Future Trends
Radiation induced xerostomia is a persistent clinical presentation that affects the quality of life in head and neck cancer patients even with the best of the intensity modulated radiotherapy protocols. Comprehensive review of the anatomic, histologic, developmental and neuronal entities of salivary glands from a regenerative perspective, ensuing radiation is taken. It also evaluates the systemic and glandular radiation responses that form the early and late clinical changes. From these, the article submits probable strategies; based on the current knowledge and future challenges involved, in reversing radiation induced xerostomia. Further, it elaborates on the status of radioprotectors and mitigators including the recently reported biologic and chemical derivatives and proposes the rationale of using combination radioprotector therapy in radiation injuries. A brief of palliative regimes, alternate treatment modes and technologic advancements in radiotherapy are also explained. Salivary gland histologic components, which need to be protected in the emerging radiotherapy protocols and can be targeted in different salivary gland regeneration therapies is highlighted. The paper contributes to an improved understanding in radiation induced xerostomia and deliberates on novel mechanisms towards enhancing quality of life in head and neck cancer radiotherapy patients
Aqueous Angiography with Fluorescein and Indocyanine Green in Bovine Eyes.
PurposeWe characterize aqueous angiography as a real-time aqueous humor outflow imaging (AHO) modality in cow eyes with two tracers of different molecular characteristics.MethodsCow enucleated eyes (n = 31) were obtained and perfused with balanced salt solution via a Lewicky AC maintainer through a 1-mm side-port. Fluorescein (2.5%) or indocyanine green (ICG; 0.4%) were introduced intracamerally at 10 mm Hg individually or sequentially. With an angiographer, infrared and fluorescent images were acquired. Concurrent anterior segment optical coherence tomography (OCT) was performed, and fixable fluorescent dextrans were introduced into the eye for histologic analysis of angiographically positive and negative areas.ResultsAqueous angiography in cow eyes with fluorescein and ICG yielded high-quality images with segmental patterns. Over time, ICG maintained a better intraluminal presence. Angiographically positive, but not negative, areas demonstrated intrascleral lumens with anterior segment OCT. Aqueous angiography with fluorescent dextrans led to their trapping in AHO pathways. Sequential aqueous angiography with ICG followed by fluorescein in cow eyes demonstrated similar patterns.ConclusionsAqueous angiography in model cow eyes demonstrated segmental angiographic outflow patterns with either fluorescein or ICG as a tracer.Translational relevanceFurther characterization of segmental AHO with aqueous angiography may allow for intelligent placement of trabecular bypass minimally invasive glaucoma surgeries for improved surgical results
Community management and participation in multi-village schemes for rural water supply in India
Multi-village schemes (MVSs) connecting hundreds of villages and small towns into a bulk water distribution network represent an emerging frontier for rural water supply in low- and middle-income countries. Conventional rural water supply approaches for such contexts often advocate community management but the scale and complexity of MVSs necessitates alternative approaches. This paper presents three case studies from India of MVSs that focus on the role of communities in their overall management. These illustrate different mechanisms in which community management can or cannot be nested within an overall management system as well as different approaches for promoting community participation. The discussion draws on political economy perspectives to suggest an explanation for the differences across these case studies, while from a public policy perspective, the paper discusses how and why MVSs may lead to the decline of community management in certain contexts
Dose optimization, frequency and spectrum of Gamma-ray induced chlorophyll mutations in acid lime (Citrus aurantifolia) cv. Agamalai
Citrus, one of the most popular fruit crops grown worldwide, has high nutritional, medicinal and commercial value. This experiment aimed to investigate the effects of gamma radiation with various doses, including 0 Gy, 5Gy, 10 Gy, 15 Gy, 20 Gy, 25Gy, 30 Gy, 35 Gy, 40 Gy and 45 Gy of cobalt 60 sources on acid lime variety Agamalai citrus, (Citrus aurantifolia). The study was carried out at the Horticulture College and Research Institute in Periyakulam.The mutagenic efficiency and effectiveness were evaluated using the frequency of chlorophyll mutations and the biological damage in M1 plants. The stomatal index reduces (19.62 %– 13.99%) with increasing treatment dose, compared to control (20.39%), although guard cell dimensions, such as length (6.09 µm) in 15 Gy and breadth (4.56 µm) in 5 Gy increase with higher dose treatment than untreated (3.71 µm,3.54 µm). Identifying the mutagenic efficiency and effectiveness of the mutagen and maximising the lethal dosage is the first stage in any mutagenesis research. This work will serve as a foundation for subsequent gamma-irradiation studies in acidlime to generate desirable mutants.
Host susceptibility to tuberculosis: insights from a longitudinal study of gene expression in diabetes
Tuberculosis (TB) remains a major global disease, and diabetes which is documented to increase susceptibility to TB threefold, is also becoming pandemic. This susceptibility has been attracting extensive research interest. The increased risk of TB in diabetes may serve as a unique model to understand host susceptibility to specific pathogens in humans. To examine this rationale, we investigated expression of reported TB candidate genes in a longitudinal diabetes study. Two genes HK2 and CD28 emerged as potential culprits in diabetes-increased TB susceptibility
Decreased expression of ATP6V1H in type 2 diabetes: a pilot report on the diabetes risk study in Mexican Americans
Objective: Previous studies in mice and humans observed down-regulation of the gene expression of ATP6V1H associated with type 2 diabetes. This study identified prospectively changes in ATP6V1H expression before and after overt diabetes.
Methods: Expression of ATP6V1H in peripheral blood was compared pre and post development of diabetes in nine individuals.
Results: Considerable variation of ATP6V1H mRNA levels was observed between different individuals. However, within each individual the decrease in expression of ATP6V1H with the development of diabetes was highly statistically significant.
Conclusions: ATP6V1H may represent a critical molecular mechanism involved in the development of type 2 diabetes and its compilations through its important regulatory effect on vacuolar-ATPase activity
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