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17 results on '"Rahman, Tamanna"'

1. Influence of testing environment and loading rate on intervertebral disc compressive mechanics: An assessment of repeatability at three different laboratories

Author

Newell, Nicolas, Tapia, David Rivera, Rahman, Tamanna, Lim, Shiyin, O'Connell, Grace D, and Holsgrove, Timothy P

Subjects
Bioengineering, Musculoskeletal, intervertebral disc, loading rate, strain rate, test environment, test repeatability
Abstract

In vitro mechanical testing of intervertebral discs is crucial for basic science and pre-clinical testing. Generally, these tests aim to replicate in vivo conditions, but simplifications are necessary in specimen preparation and mechanical testing due to complexities in both structure and the loading conditions required to replicate in vivo conditions. There has been a growing interest in developing a consensus of testing protocols within the spine community to improve comparison of results between studies. The objective of this study was to perform axial compression experiments on bovine bone-disc-bone specimens at three institutions. No differences were observed between testing environment being air, with PBS soaked gauze, or a PBS bath (P > .206). A 100-fold increase in loading rate resulted in a small (2%) but significant increase in compressive mechanics (P

Published
2020

4. Interaction of Pseudomonas aeruginosa biofilm with inflammatory cytokines and immune cells

Author

Rahman, Tamanna

Subjects
616.9, RC Internal medicine, WF Respiratory system
Abstract

Colonisation and persistent lung infection by pathogens, mainly Pseudomonas aeruginosa (PA), is an important cause of morbidity and mortality in Cystic Fibrosis patients. PA persists inside the lungs by forming drug-resistant biofilms. Investigation into the behaviour of bacterial cells within these structures and their response to components of the innate immune response will give us an insight into novel approaches to combat infection. The main aim of this thesis was investigate the effect of inflammatory mediators such as cytokines and immune cells on the development of PA biofilms. For this the BioFlux system and PA expressing green fluorescent protein were used to generate biofilms. After incubation with serum, cytokines such as GM-CSF and IFN-γ, changes in the characteristic of the biofilms were analysed. No significant changes on PA biofilms were observed in the presence of the cytokines but human serum was shown to have an inhibitory effect. Incubation of PA biofilms with labelled purified human monocytes and macrophages indicate that macrophages, unlike monocytes attached to PA biofilms. Cell surface receptors expressed by monocytes and macrophages were compared and, as previously described, high mannose receptor (MR) expression was found in macrophages. MR is a carbohydrate binding receptor that plays a crucial role in innate immunity. MR binds mannose-rich carbohydrates through C-type lectin-like domains (CTLD) 4 to 7. Using a recombinant protein containing the mannose binding region of MR (CTLD 4-7-Fc) it was found that MR can directly interact with PA biofilms and that this binding is increased when Psl expression is increased. Furthermore CTLD 4-7-Fc was shown to bind crude extracts of carbohydrates from PA biofilm enriched for the extracellular polysaccharide Psl. We hypothesize that MR expressed by macrophages and dendritic cells might contribute to PA recognition through Psl. Future work will explore the capability of immune mammalian C-type lectins to recognise PA biofilms and purified Psl and elucidate the role of Psl in modulating the recognition of PA by immune cells using PA strains expressing different combinations of extracellular polysaccharides. Our results will shed light on the impact of Psl on the immune recognition of PA, and might open the avenues for the discovery of novel therapeutic targets. Dispersion is the final stage of the biofilm cycle and contributes to dispersal and transmission of pathogens to colonize new sites. Till now not many studies have focused on the role of dispersion in pathogenesis. Thus the present study also focused on the contribution of a dispersal molecule produced during PA biofilm formation termed cis-2-decenoic acid (CDA) and analyse its role in immunomodulation. Previous observations showed that addition of exogenous CDA is able to disperse mature biofilm and inhibit biofilm formation of different gram negative and gram positive bacteria such as PA, E. coli and S. aureus. The present study showed that exogenous addition of CDA is able to modify some aspects of the inflammatory response by modulating production of the pro-inflammatory cytokine TNF-α by human monocytes and macrophages. Thus the present study has identified the potential impact of CDA as an immune modulator which will offer many opportunities for development of drug with potential anti-inflammatory action.

Published
2016

5. Unequal Protection: Secondhand Smoke Threatens Health of Tenants in Multi-Unit Housing in Los Angeles.

Author

Meng, Ying-Ying, Rahman, Tamanna, Hanaya, Daniel, Lam, Vanessa, Gomez, Marlene, Toy, Peggy, and Wallace, Steven P

Subjects
Public Health, Health Sciences, Human Society, Human Geography, Policy and Administration, Tobacco, Clinical Research, Behavioral and Social Science, Prevention, Tobacco Smoke and Health, Respiratory, Adult, Air Pollution, Indoor, Child, Health Policy, Housing, Humans, Los Angeles, Public Housing, Smoking, Tobacco Smoke Pollution, United States, Vulnerable Populations
Abstract

Secondhand smoke is dangerous to a person's health at any level of exposure. Yet policies that prevent smoking are not in place for a majority of market-rate multi-unit housing complexes, according to a new survey of nearly 1,000 apartment dwellers in the city of Los Angeles. Approximately 37 percent of respondents reported that secondhand smoke had drifted into their apartments in the past year. Households with members of vulnerable populations, such as children or individuals with chronic conditions, are more likely to report smoke drifting from adjacent units. Four out of five respondents--including more than half of those who self-reported currently smoking--supported a smoke-free policy in common areas and/or individual units.

Published
2016

6. Quantifying internal intervertebral disc strains to assess nucleus replacement device designs: a digital volume correlation and ultra-high-resolution MRI study

Author

Rahman, Tamanna, primary, Tavana, Saman, additional, Baxan, Nicoleta, additional, Raftery, Kay A., additional, Morgan, George, additional, Schaer, Thomas P., additional, Smith, Nigel, additional, Moore, Axel, additional, Bull, Jonathan, additional, Stevens, Molly M., additional, and Newell, Nicolas, additional

Published
2023
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9. The Local Health Department Role in the California Climate Investments: An Opportunity to Integrate Public Health Sector Engagement in Climate Action Initiatives to Advance Environmental Health Equity

Author

Rahman, Tamanna

Subjects
Environmental health, Public health, Climate change, California Climate Investments, Cap-and-Trade, Climate Change, Environmental Health, Local Health Department, Public Health
Abstract

It is widely recognized that climate change poses a serious challenge to the field of public health due to the changing frequency and severity of impacts faced by local communities, however, addressing climate change provides the opportunity to implement solutions that build healthy, equitable, and climate-resilient communities. The public health sector works closely with local governments and community partners to address health inequities of environmental change by developing and implementing policies and programs that prioritize health, and often these activities align with climate mitigation and adaptation measures. Local health departments (LHDs) are often at the front lines working with communities disproportionately affected by climate change, therefore the public health sector has a critical role to play in advancing and mobilizing support for health-based climate change strategies that improve health outcomes, address inequities, and reduce greenhouse gas emissions. California’s strategy to reinvest cap-and-trade funds into climate change mitigation and adaptation activities, known as the California Climate Investments (CCI), offers a significant opportunity for the public health sector to integrate health consideration into local climate mitigation and adaptation efforts, however, there has been limited public health sector engagement at the local level. The work presented here evaluates the CCI through a public health practice lens to identify opportunities to increase LHD engagement in the CCI at the local level to ensure that climate action strategies integrate public health consideration and promote environmental health equity. The first section provides a critical review of the literature on climate change vulnerability assessment frameworks to examine the potential climate change-related health impacts within the context of Los Angeles County to inform climate change adaptation planning. The next sections focus on the CCI to identify opportunities to increase LHD engagement and integrate public health consideration in the implementation of CCI funded projects. First, selected CCI program guidelines and publicly available documents were coded and analyzed to examine the programmatic alignment between CCI program requirements and foundational LHD activities to identify opportunities for LHDs to engage and actively support partner organizations. Next, interviews were conducted with selected LHD personnel and key respondents to identify best practices of LHD engagement in urban greening and community forestry initiatives funded through the CCI. Document analysis and interviews demonstrated that there are opportunities for LHD engagement, however, barriers exist. Lack of information about LHD eligible to apply, limited requirements for LHD engagement, and insufficient awareness of LHDs about the CCI limit public health sector engagement at the local level. Recommendations to address these barriers include increasing outreach to LHDs, establishing a more robust role for LHDs, increasing the climate adaptation component of the CCI programs to provide opportunity for greater LHD engagement. California’s approach to implementing the cap-and-trade program and reinvesting auction proceeds in local climate action initiatives to benefit vulnerable communities provides a model for other jurisdictions. As other states look to cap-and-trade, it is critical that California pushes innovation and sets the example of how to effectively integrate public health sector engagement in all levels of climate action to reduce greenhouse gas emissions, help communities adapt to climate change, and advance environmental health equity so that communities can thrive and become climate-resilient.

Published
2019

11. An in vitro comparison of three nucleus pulposus removal techniques for partial intervertebral disc replacement: An ultra‐high resolution MRI study.

Author

Rahman, Tamanna, Baxan, Nicoleta, Murray, Robert T., Tavana, Saman, Schaer, Thomas P., Smith, Nigel, Bull, Jonathan, and Newell, Nicolas

Subjects
NUCLEUS pulposus, INTERVERTEBRAL disk, LASER ablation, RAZORS, MAGNETIC resonance imaging
Abstract

Background: Nuclectomy, also known as nucleotomy, is a percutaneous surgical procedure performed to remove nucleus material from the center of the disc. Multiple techniques have been considered to perform a nuclectomy, however, the advantages and disadvantages of each are not well understood. Aims: This in vitro biomechanical investigation on human cadaveric specimens aimed to quantitatively compare three nuclectomy techniques performed using an automated shaver, rongeurs, and laser. Material & Methods: Comparisons were made in terms of mass, volume and location of material removal, changes in disc height, and stiffness. Fifteen vertebra–disc–vertebra lumbar specimens were acquired from six donors (40 ± 13 years) and split into three groups. Before and after nucleotomy axial mechanical tests were performed and T2‐weighted 9.4T MRIs were acquired for each specimen. Results: When using the automated shaver and rongeurs similar volumes of disc material were removed (2.51 ± 1.10% and 2.76 ± 1.39% of the total disc volume, respectively), while considerably less material was removed using the laser (0.12 ± 0.07%). Nuclectomy using the automated shaver and rongeurs significantly reduced the toe‐region stiffness (p = 0.036), while the reduction in the linear region stiffness was significant only for the rongeurs group (p = 0.011). Post‐nuclectomy, 60% of the rongeurs group specimens showed changes in the endplate profile while 40% from the laser group showed subchondral marrow changes. Discussion: From the MRIs, homogeneous cavities were seen in the center of the disc when using the automated shaver. When using rongeurs, material was removed non‐homogeneously both from the nucleus and annulus regions. Laser ablation formed small and localized cavities suggesting that the technique is not suitable to remove large volumes of material unless it is developed and optimized for this application. Conclusion: The results demonstrate that both rongeurs and automated shavers can be used to remove large volumes of NP material but the reduced risk of collateral damage to surrounding tissues suggests that the automated shaver may be more suitable. [ABSTRACT FROM AUTHOR]

Published
2023
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17. Unequal Protection: Secondhand Smoke Threatens Health of Tenants in Multi-Unit Housing in Los Angeles.

Author

Meng YY, Rahman T, Hanaya D, Lam V, Gomez M, Toy P, and Wallace SP

Subjects
Adult, Air Pollution, Indoor prevention & control, Child, Health Policy, Humans, Los Angeles epidemiology, Public Housing, Smoking, Tobacco Smoke Pollution prevention & control, United States, Vulnerable Populations, Air Pollution, Indoor adverse effects, Housing legislation & jurisprudence, Tobacco Smoke Pollution adverse effects
Abstract

Secondhand smoke is dangerous to a person's health at any level of exposure. Yet policies that prevent smoking are not in place for a majority of market-rate multi-unit housing complexes, according to a new survey of nearly 1,000 apartment dwellers in the city of Los Angeles. Approximately 37 percent of respondents reported that secondhand smoke had drifted into their apartments in the past year. Households with members of vulnerable populations, such as children or individuals with chronic conditions, are more likely to report smoke drifting from adjacent units. Four out of five respondents--including more than half of those who self-reported currently smoking--supported a smoke-free policy in common areas and/or individual units.

Published
2016

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