The engineering significance of shrinkage and swelling soils in blast damage investigations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vitton, S.J.; Harris, W.W.

1996-12-01

In the US each year it has been estimated that expansive soils cause approximately $9.0 billion in damage to buildings, roads, airports, and other facilities. This figure alone exceeds the damage estimate for earthquakes, floods, tornadoes, and hurricanes combined. Unfortunately, some cases of expansive soil damage (swelling) are blamed on rock blasting operations if the blasting operations are located within the immediate area. While simple tests, such as the Atterberg limits test, can characterize a soil as expansive, it does not necessarily answer the question whether the foundation soils are causing distresses to a structure. In particular, it appears thatmore » once a soil has been labeled as nonexpansive it is no longer considered as a problem soil, in which case blast vibrations become the prime suspect. It should be emphasized, however, that even non-plastic soils, those soils with low to nonexistent plastic indexes, can exhibit significant shrinkage characteristics that can result in significant damage to structures. While expansive soil is a function of the mineralogy of the soil particles, i.e., swelling clay minerals, shrinkage is caused by the loss of moisture from soil as capillary pressures exceed the cohesion or tensile strength and is therefore a function of the soils particle size and its pore size distribution. This is a significant problem for all fine grained soils regardless of the soil`s mineralogy. It`s particularly important for regions of the US that typically have a positive water balance but experience significant drought periods when soil moisture is lost.« less

Damage Proxy Map from InSAR Coherence Applied to February 2011 M6.3 Christchurch Earthquake, 2011 M9.0 Tohoku-oki Earthquake, and 2011 Kirishima Volcano Eruption

NASA Astrophysics Data System (ADS)

Yun, S.; Agram, P. S.; Fielding, E. J.; Simons, M.; Webb, F.; Tanaka, A.; Lundgren, P.; Owen, S. E.; Rosen, P. A.; Hensley, S.

2011-12-01

Under ARIA (Advanced Rapid Imaging and Analysis) project at JPL and Caltech, we developed a prototype algorithm to detect surface property change caused by natural or man-made damage using InSAR coherence change. The algorithm was tested on building demolition and construction sites in downtown Pasadena, California. The developed algorithm performed significantly better, producing 150 % higher signal-to-noise ratio, than a standard coherence change detection method. We applied the algorithm to February 2011 M6.3 Christchurch earthquake in New Zealand, 2011 M9.0 Tohoku-oki earthquake in Japan, and 2011 Kirishima volcano eruption in Kyushu, Japan, using ALOS PALSAR data. In Christchurch area we detected three different types of damage: liquefaction, building collapse, and landslide. The detected liquefaction damage is extensive in the eastern suburbs of Christchurch, showing Bexley as one of the most significantly affected areas as was reported in the media. Some places show sharp boundaries of liquefaction damage, indicating different type of ground materials that might have been formed by the meandering Avon River in the past. Well reported damaged buildings such as Christchurch Cathedral, Canterbury TV building, Pyne Gould building, and Cathedral of the Blessed Sacrament were detected by the algorithm. A landslide in Redcliffs was also clearly detected. These detected damage sites were confirmed with Google earth images provided by GeoEye. Larger-scale damage pattern also agrees well with the ground truth damage assessment map indicated with polygonal zones of 3 different damage levels, compiled by the government of New Zealand. The damage proxy map of Sendai area in Japan shows man-made structure damage due to the tsunami caused by the M9.0 Tohoku-oki earthquake. Long temporal baseline (~2.7 years) and volume scattering caused significant decorrelation in the farmlands and bush forest along the coastline. The 2011 Kirishima volcano eruption caused a lot of ash fall deposit in the southeast from the volcano. The detected ash fall damage area exactly matches the in-situ measurements implemented through fieldwork by Geological Survey of Japan. With 99-percentile threshold for damage detection, the periphery of the detected damage area aligns with a contour line of 100 kg/m2 ash deposit, equivalent to 10 cm of depth assuming a density of 1000 kg/m3 for the ash layer. With growing number of InSAR missions, rapidly produced accurate damage assessment maps will help save people, assisting effective prioritization of rescue operations at early stage of response, and significantly improve timely situational awareness for emergency management and national / international assessment and response for recovery planning. Results of this study will also inform the design of future InSAR missions including the proposed DESDynI.

Methimazole-induced hypothyroidism causes cellular damage in the spleen, heart, liver, lung and kidney.

PubMed

Cano-Europa, Edgar; Blas-Valdivia, Vanessa; Franco-Colin, Margarita; Gallardo-Casas, Carlos Angel; Ortiz-Butrón, Rocio

2011-01-01

It is known that a hypothyroidism-induced hypometabolic state protects against oxidative damage caused by toxins. However, some workers demonstrated that antithyroid drug-induced hypothyroidism can cause cellular damage. Our objective was to determine if methimazole (an antithyroid drug) or hypothyroidism causes cellular damage in the liver, kidney, lung, spleen and heart. Twenty-five male Wistar rats were divided into 5 groups: euthyroid, false thyroidectomy, thyroidectomy-induced hypothyroidism, methimazole-induced hypothyroidism (60 mg/kg), and treatment with methimazole (60 mg/kg) and a T₄ injection (20 μg/kg/d sc). At the end of the treatments (4 weeks for the pharmacological groups and 8 weeks for the surgical groups), the animals were anesthetized with sodium pentobarbital and they were transcardially perfused with 10% formaldehyde. The spleen, heart, liver, lung and kidney were removed and were processed for embedding in paraffin wax. Coronal sections were stained with hematoxylin-eosin. At the end of treatment, animals with both the methimazole- and thyroidectomy-induced hypothyroidism had a significant reduction of serum concentration of thyroid hormones. Only methimazole-induced hypothyroidism causes cellular damage in the kidney, lung, liver, heart, kidney and spleen. In addition, animals treated with methimazole and T₄ showed cellular damage in the lung, spleen and renal medulla with lesser damage in the liver, renal cortex and heart. The thyroidectomy only altered the lung structure. The alterations were prevented by T₄ completely in the heart and partially in the kidney cortex. These results indicate that tissue damage found in hypothyroidism is caused by methimazole. Copyright © 2009 Elsevier GmbH. All rights reserved.

Effects of low dose pre-irradiation on hepatic damage and genetic material damage caused by cyclophosphamide.

PubMed

Yu, H-S; Song, A-Q; Liu, N; Wang, H

2014-01-01

Cyclophosphamide (CTX) can attack tumour cells, but can also damage the other cells and microstructures of an organism at different levels, such as haematopoietic cells, liver cells, peripheral lymphocyte DNA, and genetic materials. Low dose radiation (LDR) can induce general adaptation reaction. In this study, we explore the effects of low dose radiation on hepatic damage and genetic material damage caused by CTX. Mice were implanted subcutaneously with S180 cells in the left groin (control group excluded). On days 8 and 11, mice of the LDR and LDR+CTX groups were given 75 mGy of whole-body γ-irradiation; whereas mice of the CTX and LDR+CTX groups were injected intraperitoneally with 3.0 mg of CTX. All mice were sacrificed on day 13. DNA damage of the peripheral lymphocytes, alanine aminotransferase (ALT) activity, total protein (TP), albumin (ALB) of the plasma, malonyl-dialdheyde (MDA) content, superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activity of the hepatic homogenate, and micronucleus frequency (MNF) of polychromatoerythrocytes in the bone marrow were analysed. The control group had the lowest MDA content and the highest SOD and GSH-PX activity, whereas the CTX group had the highest MDA content and the lowest SOD and GSH-PX activity. Compared with the CTX group, the MDA content decreased significantly (p < 0.01) and the SOD and GSH-PX activity increased significantly (p < 0.05) in the LDR+CTX group. TP and ALB in control group were higher than that of the other groups. Compared with the sham-irradiated group, TP and ALB in the LDR group elevated significantly (p < 0.05). The control group had the lightest DNA damage, whereas the CTX group had the severest. DNA damage in LDR+CTX group was much lighter compared with that of the CTX group (p < 0.05). MNF in the CTX group increased significantly compared with the control and the sham-irradiated groups (p < 0.01). Compared with the CTX group, MNF in LDR+CTX group had a tendency of decline, but without statistical significance (p > 0.05). Pre-chemotherapeutic LDR can induce the activities of anti-oxidative enzymes and promote the elimination of free radicles to alleviate the damaging effects of oxidative stress to hepatic tissue caused by high-dose CTX. At the same time, LDR has no obvious effect on the ALT activity of plasma, but may have protective effect on the protein synthesis function of the liver. High-dose CTX chemotherapy can cause DNA damage of peripheral lymphocytes; however, LDR before chemotherapy may have certain protective effect on DNA damage. Moreover, CTX has potent mutagenic effect; however, LDR may have no protective effect against the genetic toxicity of CTX chemotherapy.

Geo-infrastructure damage assessment, repair and mitigation strategies.

DOT National Transportation Integrated Search

2013-09-01

The 2011 Missouri River flooding caused significant damage to many geo-infrastructure systems including levees, bridge : abutments/foundations, paved and unpaved roadways, culverts, and embankment slopes in western Iowa. The flooding resulted in : cl...

A new EEMD-based scheme for detection of insect damaged wheat kernels using impact acoustics

USDA-ARS?s Scientific Manuscript database

Internally feeding insects inside wheat kernels cause significant, but unseen economic damage to stored grain. In this paper, a new scheme based on ensemble empirical mode decomposition (EEMD) using impact acoustics is proposed for detection of insect-damaged wheat kernels, based on its capability t...

Control of deer damage with chemical repellents in regenerating hardwood stands

Treesearch

Brian J. MacGowan; Larry Severeid; Fred, Jr. Skemp

2004-01-01

Wildlife damage can be a major problem in natural tree regeneration or tree plantings. In the North Central Hardwoods region, white-tailed deer (Odocoileus virginianus) are a significant cause of damage to hardwood seedlings. We evaluated the use of a combination of chemical repellents (Hinder®, Tree Guard®, chicken eggs, and...

Risk Assessment for the Southern Pine Beetle

Treesearch

Andrew Birt

2011-01-01

The southern pine beetle (SPB) causes significant damage (tree mortality) to pine forests. Although this tree mortality has characteristic temporal and spatial patterns, the precise location and timing of damage is to some extent unpredictable. Consequently, although forest managers are able to identify stands that are predisposed to SPB damage, they are unable to...

Quantifying the Influence of Lightning Strike Pressure Loading on Composite Specimen Damage

NASA Astrophysics Data System (ADS)

Foster, P.; Abdelal, G.; Murphy, A.

2018-04-01

Experimental work has shown that a component of lightning strike damage is caused by a mechanical loading. As the profile of the pressure loading is unknown a number of authors propose different pressure loads, varying in form, application area and magnitude. The objective of this paper is to investigate the potential contribution of pressure loading to composite specimen damage. This is achieved through a simulation study using an established modelling approach for composite damage prediction. The study examines the proposed shockwave loads from the literature. The simulation results are compared with measured test specimen damage examining the form and scale of damage. The results for the first time quantify the significance of pressure loading, demonstrating that although a pressure load can cause damage consistent with that measured experimentally, it has a negligible contribution to the overall scale of damage. Moreover the requirements for a pressure to create the damage behaviours typically witnessed in testing requires that the pressure load be within a very precise window of magnitude and loading area.

Patients referred to an indoor air health clinic: exposure to water-damaged buildings causes an increase of lymphocytes in bronchoalveolar lavage and a decrease of CD19 leucocytes in peripheral blood.

PubMed

Wolff, Henrik; Mussalo-Rauhamaa, Helena; Raitio, Hanna; Elg, Peter; Orpana, Arto; Piilonen, Anneli; Haahtela, Tari

2009-01-01

Respiratory and other symptoms are often associated with exposure to microbes present in water-damaged buildings. We examined 82 consecutive patients referred to the Indoor Air Clinic, Helsinki University Hospital, due to symptoms suspected of having been caused by long-term exposure to water damage in the home or workplace. Exposure to water damage was assessed by building inspections and microbial analyses as needed. Bronchoalveolar lavage, lung function measurements, skin prick tests to inhalant allergens and radiological examinations were performed in all patients. Leucocyte subsets in peripheral blood were analysed in 35 patients. Marked water damage was detected in the homes or workplaces of 47 (59%) patients; the remaining 34 patients formed the control group. The exposed group expressed more symptoms in total than the control group: fatigue, conjunctival symptoms, rhinitis with sinusitis, recurrent bronchitis and asthma were more common in the exposed group, but a significant difference was seen only for headache. In BAL (bronchoalveolar lavage) samples, lymphocytes represented 25% of the total cell population in non-smoking-exposed patients compared with 12% in control patients (p=0.004). In peripheral blood, CD19 leucocytes were significantly decreased in the exposed group (7.5% versus 12.3%; p<0.01). Confirmed exposure to water damage was associated with an increase in symptoms. Exposure to water damage caused a significant change in the cellular composition in BAL fluid (lymphocytosis) and blood (decrease of CD19 cells). The depletion of CD19 leucocytes in peripheral blood may indicate an active immune response in the lungs.

Detection of in vivo DNA damage induced by ethanol in multiple organs of pregnant mice using the alkaline single cell gel electrophoresis (Comet) assay.

PubMed

Kido, Ryoko; Sato, Itaru; Tsuda, Shuji

2006-01-01

Ethanol is principal ingredient of alcohol beverage, but considered as human carcinogen, and has neurotoxicity. Alcohol consumption during pregnancy often causes fetal alcohol syndrome. The DNA damage is one of the important factors in carcinogenicity or teratogenicity. To detect the DNA damage induced by ethanol, we used an in vivo alkaline single cell gel electrophoresis (Comet) assay in pregnant mice organs and embryos. Pregnant ICR mice on Day 7 of gestation were treated with 2, 4 or 8 g/kg ethanol, and maternal organs/tissues and embryos were subjected to the Comet assay at 4, 8, 12 and 24 hr after ethanol treatment. Four and 8 g/kg ethanol induced DNA damage in brain, lung and embryos at 4 or 8 hr after the treatment. Two g/kg ethanol did not cause any DNA damage, and 8 g/kg ethanol only increased the duration of DNA damage without distinct increase in the degree of the damage. No significant DNA damage was observed in the liver. To detect the effect of acetaldehyde, disulfiram, acetaldehyde dehydrogenase inhibitor, was administered before 4 g/kg ethanol treatment. No significant increase of DNA damage was observed in the disulfiram pre-treated group. These data indicate that ethanol induces DNA damage, which might be related to ethanol toxicity. Since pre-treatment of disulfiram did not increase DNA damage, DNA damage observed in this study might not be the effect of acetaldehyde.

Red Pine Shoot Moth

Treesearch

John Hainze; David Hall

The red pine shoot moth recently caused significant damage to red pine plantations in Minnesota, Wisconsin and Michigan. Trees of all ages have been attacked, but the most severe damage has occurred in 20-40 year old plantations growing on sandy soils.

Modifying effect of dynamic space flight factors on radiation damage of air-dry seeds of Crepis capillaris (L) Wallr.

PubMed

Vaulina, E N; Kostina, L N

1975-01-01

The influence of dynamic factors (vibration and linear acceleration) on the rate of chromosome aberrations in Crepis capillaris was studied. The vibrational process simulated was similar in its characteristics to that occurring at the launch of spaceships. In combination with linear acceleration it caused a statistically significant increase in the rate of chromosome aberrations compared with the control (R=7.70). The dynamic factors modified the effect of radiation damage induced by acute gamma-irradiation (3 krad). Pre-radiation treatment with vibration and acceleration on the seeds caused a significant decrease (R=10.23) of the effect of radiation damage, from 15.57% to 9.74%. The post-radiation treatment of C. capillaris seeds with the dynamic factors did not change the rate of chromosome aberrations significantly (from 15.57% to 15.90%).

Protective role of integrin-linked kinase against oxidative stress and in maintenance of genomic integrity

PubMed Central

Im, Michelle; Dagnino, Lina

2018-01-01

The balance between the production of reactive oxygen species and activation of antioxidant pathways is essential to maintain a normal redox state in all tissues. Oxidative stress caused by excessive oxidant species generation can cause damage to DNA and other macromolecules, affecting cell function and viability. Here we show that integrin-linked kinase (ILK) plays a key role in eliciting a protective response to oxidative damage in epidermal cells. Inactivation of the Ilk gene causes elevated levels of intracellular oxidant species (IOS) and DNA damage in the absence of exogenous oxidative insults. In ILK-deficient cells, excessive IOS production can be prevented through inhibition of NADPH oxidase activity, with a concomitant reduction in DNA damage. Additionally, ILK is necessary for DNA repair processes following UVB-induced damage, as ILK-deficient cells show a significantly impaired ability to remove cyclobutane pyrimidine dimers following irradiation. Thus, ILK is essential to maintain cellular redox balance and, in its absence, epidermal cells become more susceptible to oxidative damage through mechanisms that involve IOS production by NADPH oxidase activity. PMID:29568383

Protective role of integrin-linked kinase against oxidative stress and in maintenance of genomic integrity.

PubMed

Im, Michelle; Dagnino, Lina

2018-03-02

The balance between the production of reactive oxygen species and activation of antioxidant pathways is essential to maintain a normal redox state in all tissues. Oxidative stress caused by excessive oxidant species generation can cause damage to DNA and other macromolecules, affecting cell function and viability. Here we show that integrin-linked kinase (ILK) plays a key role in eliciting a protective response to oxidative damage in epidermal cells. Inactivation of the Ilk gene causes elevated levels of intracellular oxidant species (IOS) and DNA damage in the absence of exogenous oxidative insults. In ILK-deficient cells, excessive IOS production can be prevented through inhibition of NADPH oxidase activity, with a concomitant reduction in DNA damage. Additionally, ILK is necessary for DNA repair processes following UVB-induced damage, as ILK-deficient cells show a significantly impaired ability to remove cyclobutane pyrimidine dimers following irradiation. Thus, ILK is essential to maintain cellular redox balance and, in its absence, epidermal cells become more susceptible to oxidative damage through mechanisms that involve IOS production by NADPH oxidase activity.

Impacts of tropical cyclones on Fiji and Samoa

NASA Astrophysics Data System (ADS)

Kuleshov, Yuriy; Prakash, Bipendra; Atalifo, Terry; Waqaicelua, Alipate; Seuseu, Sunny; Ausetalia Titimaea, Mulipola

2013-04-01

Weather and climate hazards have significant impacts on Pacific Island Countries. Costs of hazards such as tropical cyclones can be astronomical making enormous negative economic impacts on developing countries. We highlight examples of extreme weather events which have occurred in Fiji and Samoa in the last few decades and have caused major economic and social disruption in the countries. Destructive winds and torrential rain associated with tropical cyclones can bring the most damaging weather conditions to the region causing economic and social hardship, affecting agricultural productivity, infrastructure and economic development which can persist for many years after the initial impact. Analysing historical data, we describe the impacts of tropical cyclones Bebe and Kina on Fiji. Cyclone Bebe (October 1972) affected the whole Fiji especially the Yasawa Islands, Viti Levu and Kadavu where hurricane force winds have been recorded. Nineteen deaths were reported and damage costs caused by cyclone Bebe were estimated as exceeding F20 million (F 1972). Tropical cyclone Kina passed between Fiji's two main islands of Viti Levu and Vanua Levu, and directly over Levuka on the night of 2 January 1993 with hurricane force winds causing extensive damage. Twenty three deaths have been reported making Kina one of the deadliest hurricanes in Fiji's recent history. Severe flooding on Viti Levu, combined with high tide and heavy seas led to destruction of the Sigatoka and Ba bridges, as well as almost complete loss of crops in Sigatoka and Navua deltas. Overall, damage caused by cyclone Kina was estimated as F170 million. In Samoa, we describe devastation to the country caused by tropical cyclones Ofa (February 1990) and Val (December 1991) which were considered to be the worst cyclones to affect the Samoan islands since the 1889 Apia cyclone. In Samoa, seven people were killed due to cyclone Ofa, thousands of people were left homeless and entire villages were destroyed. Damage on Samoa totalled to US130 million. Cyclone Val caused damage and destruction to 95% of houses in Samoa and severe crop damage; total damage was estimated as US200 million. Recently, severe tropical cyclone Evan affected Samoa and Fiji (December 2012). Significant progress in operational tropical cyclone forecasting has been achieved over the past few decades which resulted in improving early warning system but death toll attributed to cyclones is still high - at least 14 deaths in Samoa are related to cyclone Evan (luckily, no death reports in Fiji). Cyclone-related economic losses also remain very high making significant negative impact on economies of the countries. Preliminary assessment of damage caused by cyclone Evan in Fiji indicates loses of about 75.29 million. By the end of this century projections suggest decreasing numbers of tropical cyclones but a possible shift towards more intense categories. In addition, geographic shifts in distribution of tropical cyclone occurrences caused by warming of the atmospheric and oceanic environment are possible. This should be taken in consideration by authorities of the Pacific Island Countries when developing adaptation strategies to increasing tropical cyclone risk due to climate change.

A large-scale assessment of European rabbit damage to agriculture in Spain.

PubMed

Delibes-Mateos, Miguel; Farfán, Miguel Ángel; Rouco, Carlos; Olivero, Jesús; Márquez, Ana Luz; Fa, John E; Vargas, Juan Mario; Villafuerte, Rafael

2018-01-01

Numerous small and medium-sized mammal pests cause widespread and economically significant damage to crops all over the globe. However, most research on pest species has focused on accounts of the level of damage. There are fewer studies concentrating on the description of crop damage caused by pests at large geographical scales, or on analysis of the ecological and anthropogenic factors correlated with these observed patterns. We investigated the relationship between agricultural damage by the European rabbit (Oryctolagus cuniculus) and environmental and anthropogenic variables throughout Spain. Rabbit damage was mainly concentrated within the central-southern regions of Spain. We found that rabbit damage increased significantly between the early 2000s and 2013. Greater losses were typical of those areas where farming dominated and natural vegetation was scarce, where main railways and highways were present, and where environmental conditions were generally favourable for rabbit populations to proliferate. From our analysis, we suggest that roads and railway lines act as potential corridors along which rabbits can spread. The recent increase in Spain of such infrastructure may explain the rise in rabbit damage reported in this study. Our approach is valuable as a method for assessing drivers of wildlife pest damage at large spatial scales, and can be used to propose methods to reduce human - wildlife conflict. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Autophagy activation promotes removal of damaged mitochondria and protects against renal tubular injury induced by albumin overload.

PubMed

Tan, Jin; Wang, Miaohong; Song, Shuling; Miao, Yuyang; Zhang, Qiang

2018-01-10

Proteinuria (albuminuria) is an important cause of aggravating tubulointerstitial injury. Previous studies have shown that autophagy activation can alleviate renal tubular epithelial cell injury caused by urinary protein, but the mechanism is not clear. Here, we investigated the role of clearance of damaged mitochondria in this protective effect. We found that albumin overload induces a significant increase in turnover of LC3-II and decrease in p62 protein level in renal proximal tubular (HK-2) cells in vitro. Albumin overload also induces an increase in mitochondrial damage. ALC, a mitochondrial torpent, alleviates mitochondrial damage induced by albumin overload and also decreases autophagy, while mitochondrial damage revulsant CCCP further increases autophagy. Furthermore, pretreatment of HK-2 cells with rapamycin reduced the amount of damaged mitochondria and the level of apoptosis induced by albumin overload. In contrast, blocking autophagy with chloroquine exerted an opposite effect. Taken together, our results indicated autophagy activation promotes removal of damaged mitochondria and protects against renal tubular injury caused by albumin overload. This further confirms previous research that autophagy activation is an adaptive response in renal tubular epithelial cells after urinary protein overload.

On the occurrence of rainstorm damage based on home insurance and weather data

NASA Astrophysics Data System (ADS)

Spekkers, M. H.; Clemens, F. H. L. R.; ten Veldhuis, J. A. E.

2014-08-01

Rainstorm damage caused by malfunctioning of urban drainage systems and water intrusion due to defects in the building envelope can be considerable. Little research on this topic focused on the collection of damage data, the understanding of damage mechanisms and the deepening of data analysis methods. In this paper, the relative contribution of different failure mechanisms to the occurrence of rainstorm damage are investigated, as well as the extent to which these mechanisms relate to weather variables. For a case study in Rotterdam, the Netherlands, a property level home insurance database of around 3100 water-related damage claims was analysed. Records include comprehensive transcripts of communication between insurer, insured and damage assessment experts, which allowed claims to be classified according to their actual damage cause. Results show that roof and wall leakage is the most frequent failure mechanism causing precipitation-related claims, followed by blocked roof gutters, melting snow and sewer flooding. Claims related to sewer flooding were less present in the data, but are associated with significantly larger claim sizes than claims in the majority class, i.e. roof and wall leakages. Rare events logistic regression analysis revealed that maximum rainfall intensity and rainfall volume are significant predictors for the occurrence probability of precipitation-related claims. Moreover, it was found that claims associated with rainfall intensities smaller than 7-8 mm in a 60 min window are mainly related to failures processes in the private domain, such as roof and wall leakages. For rainfall events that exceed the 7-8 mm h-1 threshold, failure of systems in the public domain, such as sewer systems, start to contribute considerably to the overall occurrence probability of claims. The communication transcripts, however, lacked information to be conclusive about to extent to which sewer-related claims were caused by overloading of sewer systems or failure of system components.

On the occurrence of rainstorm damage based on home insurance and weather data

NASA Astrophysics Data System (ADS)

Spekkers, M. H.; Clemens, F. H. L. R.; ten Veldhuis, J. A. E.

2015-02-01

Rainstorm damage caused by the malfunction of urban drainage systems and water intrusion due to defects in the building envelope can be considerable. Little research on this topic focused on the collection of damage data, the understanding of damage mechanisms and the deepening of data analysis methods. In this paper, the relative contribution of different failure mechanisms to the occurrence of rainstorm damage is investigated, as well as the extent to which these mechanisms relate to weather variables. For a case study in Rotterdam, the Netherlands, a property level home insurance database of around 3100 water-related damage claims was analysed. The records include comprehensive transcripts of communication between insurer, insured and damage assessment experts, which allowed claims to be classified according to their actual damage cause. The results show that roof and wall leakage is the most frequent failure mechanism causing precipitation-related claims, followed by blocked roof gutters, melting snow and sewer flooding. Claims related to sewer flooding were less present in the data, but are associated with significantly larger claim sizes than claims in the majority class, i.e. roof and wall leakages. Rare events logistic regression analysis revealed that maximum rainfall intensity and rainfall volume are significant predictors for the occurrence probability of precipitation-related claims. Moreover, it was found that claims associated with rainfall intensities smaller than 7-8 mm in a 60-min window are mainly related to failure processes in the private domain, such as roof and wall leakages. For rainfall events that exceed the 7-8 mm h-1 threshold, the failure of systems in the public domain, such as sewer systems, start to contribute considerably to the overall occurrence probability of claims. The communication transcripts, however, lacked information to be conclusive about to which extent sewer-related claims were caused by overloading of sewer systems or failure of system components.

36 CFR 223.137 - Causes for debarment.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., fire prevention, and the disposal of slash; (2) Protection of soil, water, wildlife, range, cultural, and timber resources and protection of improvements when such failure causes significant environmental, resource, or improvements damage; (3) Removal of designated timber when such failure causes substantial...

Executive attention and personality variables in patients with frontal lobe damage.

PubMed

Rodríguez-Bailón, María; Triviño, Mónica; Lupiáñez, Juan

2012-11-01

Executive Control is required to deal with novel situations or when an action plan is needed. This study aimed to highlight the executive attention deficits of patients with frontal lobe damage. To do so, the ANT-I task (Attention Network Test-Interactions) was administered for the first time to a group of 9 patients with frontal damage caused by traumatic brain injury (TBI) and a matched control group. This task made it possible to measure the three attentional networks proposed by Posner and Dehaene (1994) and their interactions. Results on the alerting and orienting networks did not show any significant differences between the groups. However, a significant effect of group on the executive control network was observed. In addition, participants' personality was assessed with a clinical inventory (the Millon Personality Inventory) that showed a significant positive correlation between borderline personality disorder and the conflict index. These results suggest that frontal lobe damage causes an exclusive impairment in the conflict resolution network that is related to personality traits characterized by a lack of behavioral control. More research will be necessary to study this causal relationship.

Suppression of plant growth by nitrogen dioxide.

PubMed

Taylor, O C; Eaton, F M

1966-01-01

Nicotiana glutinosa and pinto bean seedlings (Phaseolus vulgaris) were exposed for short periods (3 days or less) to high concentrations of NO(2) (4.11-20.53 mg/m(3) to compare the resulting leaf lesions with ozone damage produced at concentrations of 0.43 to 0.86 mg/m(3). Although the same physiological age leaf tissue was damaged by both toxicants, damage caused by NO(2) was unlike that caused by ozone. Pinto bean (Phaseolus vulgaris) and Pearson improved tomato (Lycopersicon esculentum) seedlings were continuously exposed for 10 to 22 days, to low concentrations of NO(2) (less than 1.03 mg/m(3)). These exposures caused significant growth suppression, increase in green color (total chlorophyll content), and distortion of leaves.

Laminated root rot damage in a young Douglas-fir stand.

Treesearch

E.E. Nelson

1980-01-01

Damage occurring from the disease laminated root rot {Phellinus weirii (Murr.) Gilbertson) on two 10-acre plots in a young (40-year-old) stand of Douglas-fir was studied for 25 years. After 25 years, nearly 5 percent of the basal area was killed by the disease. Stand damage caused by vegetative spread of the fungus was significantly related to...

Effect of simulated insect damage on growth and survival of northern red oak (Quercus rubra L.) seedlings

Treesearch

Susan L. Wright; Richard W. Hall; John W. Peacock

1989-01-01

Effects of simulated insect damage—artificial defoliation and root damage in combination with two levels of watering—were studied to determine the potential effect on northern red oak seedlings (Quercus rubra L.). Treatments and treatment combinations caused significant differences in stem diameter, percentage of stem dieback, and mortality....

Sex differences in the toxicity of polyethylene glycol-coated gold nanoparticles in mice

PubMed Central

Chen, Jie; Wang, Hao; Long, Wei; Shen, Xiu; Wu, Di; Song, Sha-Sha; Sun, Yuan-Ming; Liu, Pei-Xun; Fan, Saijun; Fan, Feiyue; Zhang, Xiao-Dong

2013-01-01

Gold nanoparticles have received wide interest in disease diagnosis and therapy, but one of the important issues is their toxicological effects in vivo. Sex differences in the toxicity of gold nanoparticles are not clear. In this work, body weight, organ weight, hematology, and biochemistry were used to evaluate sex differences in immune response and liver and kidney damage. Pathology was used to observe the general toxicity of reproductive organs. The immune response was influenced significantly in female mice, with obvious changes in spleen and thymus index. Hematology results showed that male mice treated with 22.5 nm gold nanoparticles received more significant infection and inflammation than female mice. Meanwhile, the biochemistry results showed that 4.4 and 22.5 nm gold nanoparticles caused more significant liver damage in male mice than female mice, while 22.5, 29.3, and 36.1 nm gold nanoparticles caused more significant kidney damage in female mice than male mice. No significant toxicological response was found in the reproductive system for female or male mice. It was found that gold nanoparticles caused more serious liver toxicity and infection in male mice than female mice. These findings indicated that sex differences may be one of the important elements for in vivo toxicity of gold nanoparticles. PMID:23861586

Management of wildlife causing damage at Argonne National Laboratory-East, DuPage County, Illinois

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-04-01

The DOE, after an independent review, has adopted an Environmental Assessment (EA) prepared by the US Department of Agriculture (USDA) which evaluates use of an Integrated Wildlife Damage Management approach at Argonne National Laboratory-East (ANL-E) in DuPage County, Illinois (April 1995). In 1994, the USDA issued a programmatic Environmental Impact Statement (EIS) that covers nationwide animal damage control activities. The EA for Management of Wildlife Causing Damage at ANL-E tiers off this programmatic EIS. The USDA wrote the EA as a result of DOE`s request to USDA to prepare and implement a comprehensive Wildlife Management Damage Plan; the USDA hasmore » authority for animal damage control under the Animal Damage Control Act of 1931, as amended, and the Rural Development, Agriculture and Related Agencies Appropriations Act of 1988. DOE has determined, based on the analysis in the EA, that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an EIS is not required. This report contains the Environmental Assessment, as well as the Finding of No Significant Impact (FONSI).« less

Muscle Damage After Total Hip Arthroplasty Through the Direct Anterior Approach for Developmental Dysplasia of the Hip.

PubMed

Kawasaki, Masashi; Hasegawa, Yukiharu; Okura, Toshiaki; Ochiai, Satoshi; Fujibayashi, Takayoshi

2017-08-01

Total hip arthroplasty (THA) through the direct anterior approach (DAA) is known to cause less muscle damage than other surgical approaches. However, more complex primary cases, such as developmental dysplasia of the hip (DDH), might often cause muscle damage. The objective of the present study was to clarify the muscle damage observed 1 year after THA through the DAA for DDH using magnetic resonance imaging. We prospectively compared the muscle cross-sectional area (M-CSA) and fatty atrophy (FA) in muscles by magnetic resonance imaging and the Harris hip score before and at 1-year follow-up after THA through the DAA in 3 groups: 37 patients with Crowe group 1 DDH (D1), 13 patients with Crowe group 2 and 3 DDH (D2 + 3), and 12 patients with osteonecrosis as a control. THA through the DAA for D1 displayed significantly decreased M-CSA and significantly increased FA in the gluteus minimus (Gmini), the tensor fasciae latae (TFL), and the obturator internus (OI). Patients with D2 + 3 group did not have decreased M-CSA in the TFL or increased FA in the Gmini. Postoperatively, a significant negative correlation was observed between the M-CSA and FA for the OI in patients with D1 and D2 + 3. THA through the DAA for DDH caused the damage in the Gmini, the TFL, and the OI; severe damage was observed in the OI, showing increased FA with decreased M-CSA in patients with both D1 and D2 + 3. Copyright © 2017 Elsevier Inc. All rights reserved.

Circulating AIM as an Indicator of Liver Damage and Hepatocellular Carcinoma in Humans

PubMed Central

Yamazaki, Tomoko; Mori, Mayumi; Arai, Satoko; Tateishi, Ryosuke; Abe, Masanori; Ban, Mihoko; Nishijima, Akemi; Maeda, Maki; Asano, Takeharu; Kai, Toshihiro; Izumino, Kiyohiro; Takahashi, Jun; Aoyama, Kayo; Harada, Sei; Takebayashi, Toru; Gunji, Toshiaki; Ohnishi, Shin; Seto, Shinji; Yoshida, Yukio; Hiasa, Yoichi; Koike, Kazuhiko; Yamamura, Ken-ichi; Inoue, Ken-ichiro; Miyazaki, Toru

2014-01-01

Background Hepatocellular carcinoma (HCC), the fifth most common cancer type and the third highest cause of cancer death worldwide, develops in different types of liver injuries, and is mostly associated with cirrhosis. However, non-alcoholic fatty liver disease often causes HCC with less fibrosis, and the number of patients with this disease is rapidly increasing. The high mortality rate and the pathological complexity of liver diseases and HCC require blood biomarkers that accurately reflect the state of liver damage and presence of HCC. Methods and Findings Here we demonstrate that a circulating protein, apoptosis inhibitor of macrophage (AIM) may meet this requirement. A large-scale analysis of healthy individuals across a wide age range revealed a mean blood AIM of 4.99±1.8 µg/ml in men and 6.06±2.1 µg/ml in women. AIM levels were significantly augmented in the younger generation (20s–40s), particularly in women. Interestingly, AIM levels were markedly higher in patients with advanced liver damage, regardless of disease type, and correlated significantly with multiple parameters representing liver function. In mice, AIM levels increased in response to carbon tetrachloride, confirming that the high AIM observed in humans is the result of liver damage. In addition, carbon tetrachloride caused comparable states of liver damage in AIM-deficient and wild-type mice, indicating no influence of AIM levels on liver injury progression. Intriguingly, certain combinations of AIM indexes normalized to liver marker score significantly distinguished HCC patients from non-HCC patients and thus could be applicable for HCC diagnosis. Conclusion AIM potently reveals both liver damage and HCC. Thus, our results may provide the basis for novel diagnostic strategies for this widespread and fatal disease. PMID:25302503

Effects of the nematicide imicyafos on soil nematode community structure and damage to radish caused by Pratylenchus penetrans

PubMed Central

Toyota, Koki; Takada, Atsushi

2011-01-01

The effects of the non-fumigant nematicide imicyafos on soil nematode community structure and damage to radish caused by Pratylenchus penetrans were evaluated in two field experiments in consecutive years (2007 and 2008). Nematode densities in soil at 0 - 10 cm (the depth of nematicide incorporation) and 10 - 30 cm were measured. The application of imicyafos had a significant impact on the density of P. penetrans at 0 - 10 cm but had no effect on free-living nematode density. PCR-DGGE analysis conducted using extracted nematodes showed that the nematode community structure 12 d after application in 2007 was altered by the application of imicyafos at the 0 - 10 cm depth, but not at 10 - 30 cm. No significant differences were observed in the diversity of the nematode community at harvest (89 and 91 d after application) between the control and imicyafos treatments in both depths and both years. In both years, the damage to radish caused by P. penetrans was markedly suppressed by the nematicide. Overall, the nematicide imicyafos decreased populations of P. penetrans in soil and thereby decreased damage to radish, while having little impact on the soil nematode community. PMID:22791909

DNA Damage in Euonymus japonicus Leaf Cells Caused by Roadside Pollution in Beijing

PubMed Central

Li, Tianxin; Zhang, Minjie; Gu, Ke; Herman, Uwizeyimana; Crittenden, John; Lu, Zhongming

2016-01-01

The inhalable particles from vehicle exhaust can cause DNA damage to exposed organisms. Research on DNA damage is primarily focused on the influence of specific pollutants on certain species or the effect of environmental pollution on human beings. To date, little research has quantitatively studied the relationship between roadside pollution and DNA damage. Based on an investigation of the roadside pollution in Beijing, Euonymus japonicus leaves of differing ages grown in heavily-polluted sections were chosen as biomonitors to detect DNA damage using the comet assay technique. The percentage of DNA in the tail and tail moment was chosen as the analysis index based on SPSS data analysis. The roadside samples showed significantly higher levels of DNA damage than non-roadside samples, which increased in older leaves, and the DNA damage to Euonymus japonicus leaf cells was positively correlated with haze-aggravated roadside pollution. The correlation between damage and the Air Quality Index (AQI) are 0.921 (one-year-old leaves), 0.894 (two-year-old leaves), and 0.878 (three-year-old leaves). Over time, the connection between DNA damage and AQI weakened, with the sensitivity coefficient for δyear 1 being larger than δyear 2 and δyear 3. These findings support the suitability and sensitivity of the comet assay for surveying plants for an estimation of DNA damage induced by environmental genotoxic agents. This study might be applied as a preliminary quantitative method for Chinese urban air pollution damage assessment caused by environmental stress. PMID:27455298

Laser pointers: toys, nuisances, or significant eye hazards?

PubMed

Yolton, R L; Citek, K; Schmeisser, E; Reichow, A W; Griffith, T

1999-05-01

Laser pointers have been used inappropriately to harass and "dazzle" victims. Reports of retinal damage caused by pointers have also been circulated in the popular press. Information on pointer abuse was collected from the literature and through discussions with specialists. Few, if any, documented cases of permanent retinal damage caused by laser pointers could be found. For actual damage to occur, viewing, times need to exceed approximately 10 seconds. Exposures of this duration would require the person being lased to cooperate by holding fixation on the laser beam. Although the risk of permanent retinal damage from a laser-pointer beam is minimal, other risks include dazzle, annoyance, and concern that a weapon-aiming device rather than a pointer is generating the laser beam.

Assessment of genotoxic effects of flumorph by the comet assay in mice organs.

PubMed

Zhang, T; Zhao, Q; Zhang, Y; Ning, J

2014-03-01

The present study investigated the genotoxic effects of flumorph in various organs (brain, liver, spleen, kidney and sperm) of mice. The DNA damage, measured as comet tail length (µm), was determined using the alkaline comet assay. The comet assay is a sensitive assay for the detection of genotoxicity caused by flumorph using mice as a model. Statistically significant increases in comet assay for both dose-dependent and duration-dependent DNA damage were observed in all the organs assessed. The organs exhibited the maximum DNA damage in 96 h at 54 mg/kg body weight. Brain showed maximum DNA damage followed by spleen > kidney > liver > sperm. Our data demonstrated that flumorph had induced systemic genotoxicity in mammals as it caused DNA damage in all tested vital organs, especially in brain and spleen.

Effects of different extenders on DNA integrity of boar spermatozoa following freezing-thawing.

PubMed

Hu, Jian-hong; Li, Qing-wang; Jiang, Zhong-liang; Li, Wen-ye

2008-12-01

The sperm-rich fraction, collected from eight mature Yorkshire boars, was frozen in an extender containing 9% LDL (w/v), 100mM trehalose, or 20% yolk (v/v), respectively. Sperm DNA integrity was assessed using the single-cell gel electrophoresis (SCGE). Other sperm quality characteristics such as motility, acrosome and membrane integrity were also monitored. The results showed that freezing-thawing caused an increase in sperm DNA fragmentation, and extender containing 9% LDL could significantly protect sperm DNA integrity (P<0.05) from the damage caused by cryopreservation and decrease DNA damages compared with extender containing 100mM trehalose and 20% yolk (v/v). No significant difference in damaged DNA was detected between frozen and unfrozen semen samples for extender of 9% LDL and 100mM trehalose, but cryopreservation could increase the degree of DNA damage (P<0.05), the percentage of damaged DNA degree of grade 2 and 3 was significantly increased. The deterioration in post-thaw sperm DNA integrity was concurrent with reduced sperm characteristics. The data here demonstrated that the cryoprotectant played a fundamental role in reducing boar sperm DNA damage and protecting DNA integrity. It can be suggested that evaluation of sperm DNA integrity, coupled with correlative and basic characteristics such as motility, acrosome integrity and membrane integrity, may aid in determining the quality of frozen boar semen.

Protective effects of Curcuma longa against neurobehavioral and neurochemical damage caused by cerium chloride in mice.

PubMed

Kadri, Yamina; Nciri, Riadh; Brahmi, Noura; Saidi, Saber; Harrath, Abdel Halim; Alwasel, Saleh; Aldahmash, Waleed; El Feki, Abdelfatteh; Allagui, Mohamed Salah

2018-05-07

Cerium chloride (CeCl 3 ) is considered an environmental pollutant and a potent neurotoxic agent. Medicinal plants have many bioactive compounds that provide protection against damage caused by such pollutants. Curcuma longa is a bioactive compound-rich plant with very important antioxidant properties. To study the preventive and healing effects of Curcuma longa on cerium-damaged mouse brains, we intraperitoneally injected cerium chloride (CeCl 3 , 20 mg/kg BW) along with Curcuma longa extract, administrated by gavage (100 mg/kg BW), into mice for 60 days. We then examined mouse behavior, brain tissue damage, and brain oxidative stress parameters. Our results revealed a significant modification in the behavior of the CeCl 3 -treated mice. In addition, CeCl 3 induced a significant increment in lipid peroxidation, carbonyl protein (PCO), and advanced oxidation protein product levels, as well as a significant reduction in superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities. Acetylcholinesterase (AChE) activity remarkably increased in the brain of CeCl 3 -treated mice. Histopathological observations confirmed these results. Curcuma longa attenuated CeCl 3 -induced oxidative stress and increased the activities of antioxidant enzymes. It also decreased AChE activity in the CeCl 3 -damaged mouse brain that was confirmed by histopathology. In conclusion, this study suggests that Curcuma longa has a neuroprotective effect against CeCl 3 -induced damage in the brain.

Removal of the blue component of light significantly decreases retinal damage after high intensity exposure.

PubMed

Vicente-Tejedor, Javier; Marchena, Miguel; Ramírez, Laura; García-Ayuso, Diego; Gómez-Vicente, Violeta; Sánchez-Ramos, Celia; de la Villa, Pedro; Germain, Francisco

2018-01-01

Light causes damage to the retina (phototoxicity) and decreases photoreceptor responses to light. The most harmful component of visible light is the blue wavelength (400-500 nm). Different filters have been tested, but so far all of them allow passing a lot of this wavelength (70%). The aim of this work has been to prove that a filter that removes 94% of the blue component may protect the function and morphology of the retina significantly. Three experimental groups were designed. The first group was unexposed to light, the second one was exposed and the third one was exposed and protected by a blue-blocking filter. Light damage was induced in young albino mice (p30) by exposing them to white light of high intensity (5,000 lux) continuously for 7 days. Short wavelength light filters were used for light protection. The blue component was removed (94%) from the light source by our filter. Electroretinographical recordings were performed before and after light damage. Changes in retinal structure were studied using immunohistochemistry, and TUNEL labeling. Also, cells in the outer nuclear layer were counted and compared among the three different groups. Functional visual responses were significantly more conserved in protected animals (with the blue-blocking filter) than in unprotected animals. Also, retinal structure was better kept and photoreceptor survival was greater in protected animals, these differences were significant in central areas of the retina. Still, functional and morphological responses were significantly lower in protected than in unexposed groups. In conclusion, this blue-blocking filter decreases significantly photoreceptor damage after exposure to high intensity light. Actually, our eyes are exposed for a very long time to high levels of blue light (screens, artificial light LED, neons…). The potential damage caused by blue light can be palliated.

Oxcarbazepine causes neurocyte apoptosis and developing brain damage by triggering Bax/Bcl-2 signaling pathway mediated caspase 3 activation in neonatal rats.

PubMed

Song, Y; Zhong, M; Cai, F-C

2018-01-01

Anti-epileptic drugs (AEDs) are the main methods for treatment of neonatal seizures; however, a few AEDs may cause developing brain damage of neonate. This study aims to investigate effects of oxcarbazepine (OXC) on developing brain damage of neonatal rats. Both of neonatal and adult rats were divided into 6 groups, including Control, OXC 187.5 mg/kg, OXC 281.25 mg/kg, OXC 375 mg/kg group, LEV and PHT group. Body weight and brain weight were evaluated. Hematoxylin and eosin (HE) and Nissl staining were used to observe neurocyte morphology and Nissl bodies, respectively. Apoptosis was examined using TUNEL assay, and caspase 8 activity was evaluated using spectrophotometer method. Cytochrome C-release was evaluated using flow cytometry. Western blot was used to examine Bax and Bcl-2 expression. OXC 375 mg/kg treatment significantly decreased brain weight compared to Control group in neonatal rats (P5 rats) (p<0.05). OXC administration causes histological changes of neurocytes. OXC 281.25 mg/kg or more concentration significantly decreased neurocytes counts and increased TUNEL-staining positive neurocytes compared to Control group (p<0.05). OXC 281.25 mg/kg and OXC 375 mg/kg significantly increased caspase 3 activity compared to Control group in P5 rats (p<0.05). OXC 281.25 mg/kg and OXC 375 mg/kg significantly increased Bax, Bax/Bcl-2 ratio and cytochrome C release in frontal lobes compared to Control group in P5 rats (p<0.05). Oxcarbazepine at a concentration of 281.25 mg/kg or more causes neurocyte apoptosis and developing brain damage by triggering Bax/Bcl-2 signaling pathway mediated caspase 3 activation in neonatal rats.

Oxidative stress, inflammation, and DNA damage in multiple organs of mice acutely exposed to amorphous silica nanoparticles.

PubMed

Nemmar, Abderrahim; Yuvaraju, Priya; Beegam, Sumaya; Yasin, Javed; Kazzam, Elsadig E; Ali, Badreldin H

2016-01-01

The use of amorphous silica (SiO2) in biopharmaceutical and industrial fields can lead to human exposure by injection, skin penetration, ingestion, or inhalation. However, the in vivo acute toxicity of amorphous SiO2 nanoparticles (SiNPs) on multiple organs and the mechanisms underlying these effects are not well understood. Presently, we investigated the acute (24 hours) effects of intraperitoneally administered 50 nm SiNPs (0.25 mg/kg) on systemic toxicity, oxidative stress, inflammation, and DNA damage in the lung, heart, liver, kidney, and brain of mice. Lipid peroxidation was significantly increased by SiNPs in the lung, liver, kidney, and brain, but was not changed in the heart. Similarly, superoxide dismutase and catalase activities were significantly affected by SiNPs in all organs studied. While the concentration of tumor necrosis factor α was insignificantly increased in the liver and brain, its increase was statistically significant in the lung, heart, and kidney. SiNPs induced a significant elevation in pulmonary and renal interleukin 6 and interleukin-1 beta in the lung, liver, and brain. Moreover, SiNPs caused a significant increase in DNA damage, assessed by comet assay, in all the organs studied. SiNPs caused leukocytosis and increased the plasma activities of lactate dehydrogenase, creatine kinase, alanine aminotranferase, and aspartate aminotransferase. These results indicate that acute systemic exposure to SiNPs causes oxidative stress, inflammation, and DNA damage in several major organs, and highlight the need for thorough evaluation of SiNPs before they can be safely used in human beings.

Protective effects of resveratrol and its analogs on age-related macular degeneration in vitro.

PubMed

Kang, Jung-Hwan; Choung, Se-Young

2016-12-01

Damage of retinal pigment epithelial (RPE) cells by A2E may be critical for age-related macular degeneration (AMD) management. Accumulation and photooxidation of A2E are known to be one of the critical causes in AMD. Here, we evaluated the protective effect of resveratrol (RES), piceatannol (PIC) and RES glycones on blue-light-induced RPE cell death caused by A2E photooxidation. A2E treatment followed by blue light exposure caused significant damages on human RPE cells (ARPE-19). But the damages were attenuated by post- and pre-treatment of RES and PIC in our in vitro models. The results of cell free system and FAB-MS analysis clearly showed that the reduction of A2E by blue light exposure was significantly rescued, and that oxidized forms of A2E were significantly reduced by RES or PIC treatment. Besides, RES or PIC inhibited the intracellular accumulation of A2E. Not only RES and PIC but RES glycones showed protection of ARPE-19 cells against A2E and blue-light-induced photo-damage. These findings demonstrate that RES and its analogs may have protective effects against A2E and blue-light-induced ARPE-19 cell death through regulation of A2E accumulation as well as photooxidation of A2E. Thus RES and its analogs may be beneficial for AMD treatment.

Effect of superhydrophobicity on surface damage of silicone rubber under AC voltage

NASA Astrophysics Data System (ADS)

Li, Yufeng; Jin, Haiyun; Nie, Shichao; Tong, Cheng; Gao, Naikui

2018-03-01

In this paper, the influence of superhydrophobicity on the surface damage of silicone rubber is studied. On a common silicone rubber surface, a droplet can become elongated, and arc discharge induced by the droplet can cause tracking on the silicone rubber surface. However, for a superhydrophobic silicone rubber surface, a droplet can leave the silicone rubber due to the low adhesion of the superhydrophobic surface. Accordingly, arc discharge caused by the droplet does not occur, and the surface of the silicone rubber is not affected. Results demonstrate that using a superhydrophobic surface has a significant effect on limiting the surface damage of silicone rubber.

Acute carbon tetrachloride induced lysosomal membrane damage and the membrane protecting effect of a new dihydroquinoline-type antioxidant.

PubMed

Toncsev, H; Pollák, Z; Kiss, A; Sréter, L; Fehér, J

1982-01-01

The authors examined the damage of lysosomal membrane caused by acute CCl4 intoxication by in vitro methods. They measured the acid phosphatase as well as beta-glucuronidase enzyme levels and determined the rate of release of these two enzymes. The in vivo changes in enzyme activity were extrapolated from the in vitro results. The CCl4 causes a significant increase in the permeability and rigidity of the lysosomal membrane. By oral and/or intraperitoneal administration of MTDQ the state of permeability can be improved or even corrected. On the basis of their results, the authors conclude that the lysosomal damage caused by CCl4 is mediated by peroxidation of lipids and the lysosomal membrane can be stabilised by MTDQ.

A Single Swede Midge (Diptera: Cecidomyiidae) Larva Can Render Cauliflower Unmarketable.

PubMed

Stratton, Chase A; Hodgdon, Elisabeth A; Zuckerman, Samuel G; Shelton, Anthony M; Chen, Yolanda H

2018-05-01

Swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidomyiidae), is an invasive pest causing significant damage on Brassica crops in the Northeastern United States and Eastern Canada. Heading brassicas, like cauliflower, appear to be particularly susceptible. Swede midge is difficult to control because larvae feed concealed inside meristematic tissues of the plant. In order to develop damage and marketability thresholds necessary for integrated pest management, it is important to determine how many larvae render plants unmarketable and whether the timing of infestation affects the severity of damage. We manipulated larval density (0, 1, 3, 5, 10, or 20) per plant and the timing of infestation (30, 55, and 80 d after seeding) on cauliflower in the lab and field to answer the following questions: 1) What is the swede midge damage threshold? 2) How many swede midge larvae can render cauliflower crowns unmarketable? and 3) Does the age of cauliflower at infestation influence the severity of damage and marketability? We found that even a single larva can cause mild twisting and scarring in the crown rendering cauliflower unmarketable 52% of the time, with more larvae causing more severe damage and additional losses, regardless of cauliflower age at infestation.

Effect of harbor modifications on the tsunami vulnerability of Crescent City, California

NASA Astrophysics Data System (ADS)

Dengler, L.; Uslu, B.

2008-12-01

Crescent City, California has experienced more damaging tsunami events in historic times than any other location on the West Coast of the United States. Thirty-one tsunamis have been observed at Crescent City since a tide gauge was established in 1933, including eleven events with maximum peak to trough wave range exceeding one meter and four that caused damage. The most damaging event occurred in 1964 as a result of the great Alaska earthquake. The ensuing tsunami flooded 29 city blocks and killed 11 in the Crescent City area. As a result of the 1964 tsunami and redevelopment projects, the Crescent City harbor was significantly modified in the early 1970s. A 200 x 300 meter small boat basin was carved into the preexisting shore line, a 123 meter dog leg extension was added to the central breakwater and significant deepening occurred on the eastern side of the harbor. In 2006, a Mw 8.3 earthquake in the Kuril Islands generated a moderate Pacific-wide tsunami. The only location with significant damage was the Crescent City harbor where strong currents damaged docks and boats, causing an estimated 9.2 million (US dollars) in damages. Strong currents estimated by the Harbor Master at 12 knots were observed near the entrance to the small boat basin. Past earthquakes from the northwestern Pacific including the 1933 M 8.3 Sanriku Japan earthquake may have produced similar amplitudes at Crescent City to the 2006 event but caused no damage. We have obtained the pre-modification harbor bathymetry and use the MOST model to compare tsunami water heights and current velocities for the 1933 and 2006 sources using modern and pre- modification bathymetry. We also examine model the 1964 inundation using the actual bathymetry and compare the results to numerical simulations that have only used the modern data.

Protective effect of acetyl-L-carnitine on propofol-induced toxicity in embryonic neural stem cells.

PubMed

Liu, Fang; Rainosek, Shuo W; Sadovova, Natalya; Fogle, Charles M; Patterson, Tucker A; Hanig, Joseph P; Paule, Merle G; Slikker, William; Wang, Cheng

2014-05-01

Propofol is a widely used general anesthetic. A growing body of data suggests that perinatal exposure to general anesthetics can result in long-term deleterious effects on brain function. In the developing brain there is evidence that general anesthetics can cause cell death, synaptic remodeling, and altered brain cell morphology. Acetyl-L-carnitine (L-Ca), an anti-oxidant dietary supplement, has been reported to prevent neuronal damage from a variety of causes. To evaluate the ability of L-Ca to protect against propofol-induced neuronal toxicity, neural stem cells were isolated from gestational day 14 rat fetuses and on the eighth day in culture were exposed for 24h to propofol at 10, 50, 100, 300 and 600 μM, with or without L-Ca (10 μM). Markers of cellular proliferation, mitochondrial health, cell death/damage and oxidative damage were monitored to determine: (1) the effects of propofol on neural stem cell proliferation; (2) the nature of propofol-induced neurotoxicity; (3) the degree of protection afforded by L-Ca; and (4) to provide information regarding possible mechanisms underlying protection. After propofol exposure at a clinically relevant concentration (50 μM), the number of dividing cells was significantly decreased, oxidative DNA damage was increased and a significant dose-dependent reduction in mitochondrial function/health was observed. No significant effect on lactase dehydrogenase (LDH) release was observed at propofol concentrations up to 100 μM. The oxidative damage at 50 μM propofol was blocked by L-Ca. Thus, clinically relevant concentrations of propofol induce dose-dependent adverse effects on rat embryonic neural stem cells by slowing or stopping cell division/proliferation and causing cellular damage. Elevated levels of 8-oxoguanine suggest enhanced oxidative damage [reactive oxygen species (ROS) generation] and L-Ca effectively blocks at least some of the toxicity of propofol, presumably by scavenging oxidative species and/or reducing their production. Published by Elsevier B.V.

Possible role of PAPR-1 in protecting human HaCaT cells against cytotoxicity of SiO2 nanoparticles.

PubMed

Gong, Chunmei; Yang, Linqing; Zhou, Jichang; Guo, Xiang; Zhuang, Zhixiong

2017-10-05

Nano-SiO 2 materials play a significant role in the engineered nanomaterials (ENMs) field. The ease of their production as well as their relatively low cost has promoted the wide use of these products in many fields. Nano-SiO 2 exposure is known to cause severe DNA damage; however, the underlying mechanisms remain poorly understood. In a previous study, we found that nano-SiO 2 exposure regulate the expression of the poly(ADP-ribose) polymerases-1 (PARP-1), a pivotal DNA repair gene, in human HaCaT cells. Here, we employed lentivirus-mediated RNA interference (RNAi) to knock down PAPR-1 expression in HaCaT cells and explored the potential role of PARP-1 in nano-SiO 2 induced cytotoxicity. We found that nano-SiO 2 treatment of HaCaT cells causes decreased cell viability, increased apoptosis and DNA damage. Nano-SiO 2 -treated HaCaT cells were also found to have slightly changed cell cycle distribution. Lentivirus-mediated PAPR-1 knockdown partially aggravated cytotoxicity and increased apoptosis induced by nano-SiO 2 treatment. Nano-SiO 2 had significant toxicity to human HaCaT cells and causes DNA damage. PAPR-1 knock-down cell line appears more sensitive to nano-SiO 2 than the control cells in DNA damage. The results suggest that PAPR-1 is involved in protecting cells from damage caused by nano-SiO 2 . Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular basis of vascular damage caused by cigarette smoke exposure and a new approach to the treatment: Alpha-linolenic acid.

PubMed

Kaplan, Halil Mahir; Kuyucu, Yurdun; Polat, Sait; Pazarci, Percin; Yegani, Arash Alizadeh; Şingirik, Ergin; Ertuğ, Peyman

2018-06-01

Exposure to cigarette smoke (CS) causes vessel damage and mechanism of this damage has not yet been clearly identified. Therefore, in this study we aimed to investigate whether vessel damage due to the CS exposure will be prevented by the alpha-linolenic acid (ALA) or not which has anti-inflammatory effect in mice. For this reason, mice were grouped as controls (with and without CS) and ALA (with and without CS). The CS application continued 5 days a week for two months. At the end of two months, the mice were killed by cervical dislocation and their blood and thoracic aortas were isolated. ALA Treatment increased acetylcholine relaxations. CS decreased acetylcholine relaxation. CS with ALA treatment increased acetylcholine relaxations versus just CS treatment. CS caused rising in cyclooxigenase-2 and phospholipase A2 levels. This rise is inhibited with ALA treatment. CS decreased eNOS levels. But this result was not statistically significant. Furthermore, according to electron microscopic study CS damaged both smooth muscle and endothelium. While ALA treatment prevented smooth muscle damage it didn't prevent endothelial damage. Using cigarette and CS exposure is a risk factor for cardiovascular disease. Our study showed that this disease. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Vitamins A, C, and E may reduce intestinal Po-210 levels after ingestion

PubMed Central

Kemp, Francis W; Portugal, Frank; Akudugu, John M.; Neti, Prasad VSV; Ferraris, Ronaldo P.; Howell, Roger W.

2016-01-01

Damage to the gut mucosa is a probable contributory cause of death from ingested 210Po. Therefore, medical products are needed that can prevent, mitigate, and/or repair gastrointestinal (GI) damage caused by high-LET radiation emitted by 210Po. The present studies investigated the capacity of a diet highly enriched with vitamins A, C, and E (vitamin ACE) to protect against intestinal mucosal damage indicated by functional reductions in nutrient transport caused by orally ingested 210Po. Mice were gavaged with 0 or 18.5 kBq 210Po-citrate and fed a control or vitamin ACE-enriched diet (the latter beginning either 96 h before or immediately after gavage). Mouse intestines significantly retained 210Po on day 8 post-gavage. The concentration of 210Po in intestinal tissues was significantly (p<0.05) lower in all vitamin ACE groups compared to control. There were borderline significant 210Po-induced reductions in intestinal absorption of D-fructose. The combination of vitamins A, C, and E may reduce 210Po incorporation in the intestines when given before, or enhance decorporation when provided after, 210Po gavage. PMID:27218295

Phototherapy causes DNA damage in peripheral mononuclear leukocytes in term infants.

PubMed

Aycicek, Ali; Kocyigit, Abdurrahim; Erel, Ozcan; Senturk, Hakan

2008-01-01

Our aim was to determine whether endogenous mononuclear leukocyte DNA strand is a target of phototherapy. The study included 65 term infants aged between 3-10 days that had been exposed to intensive (n = 23) or conventional (n = 23) phototherapy for at least 48 hours due to neonatal jaundice, and a control group (n = 19). DNA damage was assayed by single-cell alkaline gel electrophoresis (comet assay). Plasma total antioxidant capacity and total oxidant status levels were also measured, and correlation between DNA damage and oxidative stress was investigated. Mean values of DNA damage scores in both the intensive and conventional phototherapy groups were significantly higher than those in the control group (p < 0.001). Mean values and standard deviation were 32 (9), 28 (9), 21 (7) arbitrary unit, respectively. Total oxidant status levels in both the intensive and conventional phototherapy groups were significantly higher than those in the control group (p = 0.005). Mean (standard deviation) values were 18.1 (4.2), 16.9 (4.4), 13.5 (4.2) micromol H2O2 equivalent/L, respectively. Similarly, oxidative stress index levels in both the intensive and conventional phototherapy groups were significantly higher than those in the control group (p = 0.041). Plasma total antioxidant capacity and total bilirubin levels did not differ between the groups (p > 0.05). There were no significant correlations between DNA damage scores and bilirubin, total oxidant status and oxidative stress levels in either phototherapy group (p > 0.05). Both conventional phototherapy and intensive phototherapy cause endogenous mononuclear leukocyte DNA damage in jaundiced term infants.

Intracellular iron overload leading to DNA damage of lymphocytes and immune dysfunction in thalassemia major patients.

PubMed

Shaw, Jyoti; Chakraborty, Ayan; Nag, Arijit; Chattopadyay, Arnab; Dasgupta, Anjan K; Bhattacharyya, Maitreyee

2017-11-01

To investigate the cause and effects of intracellular iron overload in lymphocytes of thalassemia major patients. Sixty-six thalassemia major patients having iron overload and 10 age-matched controls were chosen for the study. Blood sample was collected, and serum ferritin, oxidative stress; lymphocyte DNA damage were examined, and infective episodes were also counted. Case-control analysis revealed significant oxidative stress, iron overload, DNA damage, and rate of infections in thalassemia cases as compared to controls. For cases, oxidative stress (ROS) and iron overload (serum ferritin) showed good correlation with R 2  = 0.934 and correlation between DNA damage and ROS gave R 2  = 0.961. We also demonstrated that intracellular iron overload in thalassemia caused oxidative damage of lymphocyte DNA as exhibited by DNA damage assay. The inference is further confirmed by partial inhibition of such damage by chelation of iron and the concurrent lowering of the ROS level in the presence of chelator deferasirox. Therefore, intracellular iron overload caused DNA fragmentation, which may ultimately hamper lymphocyte function, and this may contribute to immune dysfunction and increased susceptibility to infections in thalassemia patients as indicated by the good correlation (R 2  = 0.91) between lymphocyte DNA damage and rate of infection found in this study. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Molecular mechanisms of phoxim-induced silk gland damage and TiO2 nanoparticle-attenuated damage in Bombyx mori.

PubMed

Li, Bing; Yu, Xiaohong; Gui, Suxin; Xie, Yi; Zhao, Xiaoyang; Hong, Jie; Sun, Qingqing; Sang, Xuezi; Sheng, Lei; Cheng, Zhe; Cheng, Jie; Hu, Rengping; Wang, Ling; Shen, Weide; Hong, Fashui

2014-06-01

Phoxim is a useful organophosphate (OP) pesticide used in agriculture in China, however, exposure to this pesticide can result in a significant reduction in cocooning in Bombyx mori (B. mori). Titanium dioxide nanoparticles (TiO2 NPs) have been shown to decrease phoxim-induced toxicity in B. mori; however, very little is known about the molecular mechanisms of silk gland damage due to OP exposure and repair of gland damage by TiO2 NP pretreatment. In the present study, exposure to phoxim resulted in a significant reduction in cocooning rate in addition to silk gland damage, whereas TiO2 NP attenuated phoxim-induced gland damage, increased the antioxidant capacity of the gland, and increased cocooning rate in B. mori. Furthermore, digital gene expression data suggested that phoxim exposure led to significant alterations in the expression of 833 genes. In particular, phoxim exposure caused significant down-regulation of Fib-L, Ser2, Ser3, and P25 genes involved in silk protein synthesis, and up-regulation of SFGH, UCH3, and Salhh genes involved in silk protein hydrolysis. A combination of both phoxim and TiO2 NP treatment resulted in marked changes in the expression of 754 genes, while treatment with TiO2 NPs led to significant alterations in the expression of 308 genes. Importantly, pretreatment with TiO2 NPs increased Fib-L, Ser2, Ser3, and P25 expression, and decreased SFGH, UCH3, and Salhh expression in silk protein in the silk gland under phoxim stress. Therefore, Fib-L, Ser2, Ser3, P25, SFGH, UCH3, and Salhh may be potential biomarkers of silk gland toxicity in B. mori caused by phoxim exposure. Copyright © 2013 Elsevier Ltd. All rights reserved.

Behavioral and genetic effects promoted by sleep deprivation in rats submitted to pilocarpine-induced status epilepticus.

PubMed

Matos, Gabriela; Ribeiro, Daniel A; Alvarenga, Tathiana A; Hirotsu, Camila; Scorza, Fulvio A; Le Sueur-Maluf, Luciana; Noguti, Juliana; Cavalheiro, Esper A; Tufik, Sergio; Andersen, Monica L

2012-05-02

The interaction between sleep deprivation and epilepsy has been well described in electrophysiological studies, but the mechanisms underlying this association remain unclear. The present study evaluated the effects of sleep deprivation on locomotor activity and genetic damage in the brains of rats treated with saline or pilocarpine-induced status epilepticus (SE). After 50 days of pilocarpine or saline treatment, both groups were assigned randomly to total sleep deprivation (TSD) for 6 h, paradoxical sleep deprivation (PSD) for 24 h, or be kept in their home cages. Locomotor activity was assessed with the open field test followed by resection of brain for quantification of genetic damage by the single cell gel electrophoresis (comet) assay. Status epilepticus induced significant hyperactivity in the open field test and caused genetic damage in the brain. Sleep deprivation procedures (TSD and PSD) did not affect locomotor activity in epileptic or healthy rats, but resulted in significant DNA damage in brain cells. Although PSD had this effect in both vehicle and epileptic groups, TSD caused DNA damage only in epileptic rats. In conclusion, our results revealed that, despite a lack of behavioral effects of sleep deprivation, TSD and PSD induced genetic damage in rats submitted to pilocarpine-induced SE. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Extensive tissue damage of bovine ovaries after bipolar ovarian drilling compared to monopolar electrocoagulation or carbon dioxide laser.

PubMed

Hendriks, Marja-Liisa; van der Valk, Paul; Lambalk, Cornelis B; Broeckaert, Mark A M; Homburg, Roy; Hompes, Peter G A

2010-02-01

To evaluate the size of ovarian damage caused by ovarian drilling in polycystic ovary syndrome, the amount of inflicted damage was assessed for the most frequently used ovarian drilling techniques. Experimental prospective design. University clinic. Six fresh bovine ovaries per technique. Carbon dioxide (CO(2)) laser, monopolar electrocoagulation, and bipolar electrocoagulation were used for in vitro ovarian drilling. Amount of inflicted ovarian damage per procedure. Bipolar electrocoagulation resulted in significantly more destruction per burn than the CO(2) laser and monopolar electrocoagulation (287.6 versus 24.0 and 70.0 mm(3), respectively). The damage found per lesion was multiplied by the regularly applied number of punctures per procedure in daily practice (based on the literature). Again, the bipolar electrocoagulation resulted in significantly more tissue damage than the CO(2) laser and monopolar coagulation (2,876 versus 599 and 700 mm(3), respectively). Ovarian drilling, especially bipolar electrocoagulation, causes extensive destruction of the ovary. Given the same clinical effectiveness of the various procedures, it is essential to use the lowest possible dose that works; thus, the first choice should be CO(2) laser or monopolar electrocoagulation. Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Localized damage caused by topographic amplification during the 2010 M7.0 Haiti earthquake

USGS Publications Warehouse

Hough, S.E.; Altidor, J.R.; Anglade, D.; Given, D.; Janvier, M.G.; Maharrey, J.Z.; Meremonte, M.; Mildor, B.S.-L.; Prepetit, C.; Yong, A.

2010-01-01

Local geological conditions, including both near-surface sedimentary layers and topographic features, are known to significantly influence ground motions caused by earthquakes. Microzonation maps use local geological conditions to characterize seismic hazard, but commonly incorporate the effect of only sedimentary layers. Microzonation does not take into account local topography, because significant topographic amplification is assumed to be rare. Here we show that, although the extent of structural damage in the 2010 Haiti earthquake was primarily due to poor construction, topographic amplification contributed significantly to damage in the district of Petionville, south of central Port-au-Prince. A large number of substantial, relatively well-built structures situated along a foothill ridge in this district sustained serious damage or collapse. Using recordings of aftershocks, we calculate the ground motion response at two seismic stations along the topographic ridge and at two stations in the adjacent valley. Ground motions on the ridge are amplified relative to both sites in the valley and a hard-rock reference site, and thus cannot be explained by sediment-induced amplification. Instead, the amplitude and predominant frequencies of ground motion indicate the amplification of seismic waves by a narrow, steep ridge. We suggest that microzonation maps can potentially be significantly improved by incorporation of topographic effects. ?? 2010 Macmillan Publishers Limited. All rights reserved.

Effect of saffron (Crocus sativus L.) on sodium valporate induced cytogenetic and testicular alterations in albino rats.

PubMed

Sakr, Saber A; Zowail, Mohamed E; Marzouk, Amera M

2014-09-01

The present study investigated the cytogenetic and testicular damage induced by the antiepileptic drug, sodium valporate (SVP) in albino rats and the effect of saffron aqueous extracts. Treating rats with SVP caused a significant increase in the chromosomal aberrations either structural or numerical and decreased the mitotic index. Besides, animals administered SVP showed DNA damage appeared in the single strand breaks (comet assay). Testis of SVP-treated rats showed many histopathological changes. A significant decrease in seminiferous tubules and their epithelial heights diameters and inhibition of spermatogenesis was recorded. In addition, the number of sperm head abnormalities was increased. Biochemical results revealed an increase in malondialdhyde (MDA) which is lipid peroxidation marker and a significant decrease in the level of serum antioxidant enzyme, catalase (CAT) and reducing antioxidant power (RAP). Animals given SVP and saffron showed an improvement in chromosomal aberrations, mitotic index, DNA damage and testicular alterations caused by SVP. Moreover, MDA decreased and CAT and RAP increased. It is concluded from the present results that the ameliorative effects of saffron extract against SVP-induced cytogenetic and testicular damage in albino rats may be due to the presence of one or more antioxidant components of saffron.

Prevention of Severe Hypoglycemia-Induced Brain Damage and Cognitive Impairment with Verapamil.

PubMed

Jackson, David A; Michael, Trevin; Vieira de Abreu, Adriana; Agrawal, Rahul; Bortolato, Marco; Fisher, Simon J

2018-05-03

People with insulin-treated diabetes are uniquely at risk for severe hypoglycemia-induced brain damage. Since calcium influx may mediate brain damage, we tested the hypothesis that the calcium channel blocker, verapamil, would significantly reduce brain damage and cognitive impairment caused by severe hypoglycemia. Ten-week-old Sprague-Dawley rats were randomly assigned to one of three treatments; 1) control hyperinsulinemic (200 mU.kg -1 min -1 ) euglycemic (80-100mg/dl) clamps (n=14), 2) hyperinsulinemic hypoglycemic (10-15mg/dl) clamps (n=16), or 3) hyperinsulinemic hypoglycemic clamps followed by a single treatment with verapamil (20mg/kg) (n=11). As compared to euglycemic controls, hypoglycemia markedly increased dead/dying neurons in the hippocampus and cortex, by 16-fold and 14-fold, respectively. Verapamil treatment strikingly decreased hypoglycemia-induced hippocampal and cortical damage, by 87% and 94%, respectively. Morris Water Maze probe trial results demonstrated that hypoglycemia induced a retention, but not encoding, memory deficit (noted by both abolished target quadrant preference and reduced target quadrant time). Verapamil treatment significantly rescued spatial memory as noted by restoration of target quadrant preference and target quadrant time. In summary, a one-time treatment with verapamil following severe hypoglycemia prevented neural damage and memory impairment caused by severe hypoglycemia. For people with insulin treated diabetes, verapamil may be a useful drug to prevent hypoglycemia-induced brain damage. © 2018 by the American Diabetes Association.

Recent changes in flood damage in the United States from observations and ACME model

NASA Astrophysics Data System (ADS)

Leng, G.; Leung, L. R.

2017-12-01

Despite efforts to mitigate flood hazards in flood-prone areas, survey- and report-based flood databases show that flood damage has increased and emerged as one of the most costly disaster in the United States since the 1990s. Understanding the mechanism driving the changes in flood damage is therefore critical for reducing flood risk. In this study, we first conduct a comprehensive analysis of the changing characteristics of flood damage at local, state and country level. Results show a significant increasing trend in the number of flood hazards, causing economic losses of up to $7 billion per year. The ratio of flood events that caused tangible economical cost to the total flood events has exhibited a non-significant increasing trend before 2007 followed by a significant decrease, indicating a changing vulnerability to floods. Analysis also reveals distinct spatial and temporal patterns in the threshold intensity of flood hazards with tangible economical cost. To understand the mechanism behind the increasing flood damage, we develop a flood damage economic model coupled with the integrated hydrological modeling system of ACME that features a river routing model with an inundation parameterization and a water use and regulation model. The model is evaluated over the country against historical records. Several numerical experiments are then designed to explore the mechanisms behind the recent changes in flood damage from the perspective of flood hazard, exposure and vulnerability, which constitute flood damage. The role of human activities such as reservoir operations and water use in modifying regional floods are also explored using the new tool, with the goal of improving understanding and modeling of vulnerability to flood hazards.

Unrepaired DNA damage in macrophages causes elevation of particulate matter- induced airway inflammatory response.

PubMed

Luo, Man; Bao, Zhengqiang; Xu, Feng; Wang, Xiaohui; Li, Fei; Li, Wen; Chen, Zhihua; Ying, Songmin; Shen, Huahao

2018-04-14

The inflammatory cascade can be initiated with the recognition of damaged DNA. Macrophages play an essential role in particulate matter (PM)-induced airway inflammation. In this study, we aim to explore the PM induced DNA damage response of macrophages and its function in airway inflammation. The DNA damage response and inflammatory response were assessed using bone marrow-derived macrophages following PM treatment and mouse model instilled intratracheally with PM. We found that PM induced significant DNA damage both in vitro and in vivo and simultaneously triggered a rapid DNA damage response, represented by nuclear RPA, 53BP1 and γH2AX foci formation. Genetic ablation or chemical inhibition of the DNA damage response sensor amplified the production of cytokines including Cxcl1, Cxcl2 and Ifn-γ after PM stimulation in bone marrow-derived macrophages. Similar to that seen in vitro , mice with myeloid-specific deletion of RAD50 showed higher levels of airway inflammation in response to the PM challenge, suggesting a protective role of DNA damage sensor during inflammation. These data demonstrate that PM exposure induces DNA damage and activation of DNA damage response sensor MRN complex in macrophages. Disruption of MRN complex lead to persistent, unrepaired DNA damage that causes elevated inflammatory response.

Influence of third-body particles originating from bone void fillers on the wear of ultra-high-molecular-weight polyethylene

PubMed Central

Cowie, Raelene M; Carbone, Silvia; Aiken, Sean; Cooper, John J; Jennings, Louise M

2016-01-01

Calcium sulfate bone void fillers are increasingly being used for dead space management in infected arthroplasty revision surgery. The presence of these materials as loose beads close to the bearing surfaces of joint replacements gives the potential for them to enter the joint becoming trapped between the articulating surfaces; the resulting damage to cobalt chrome counterfaces and the subsequent wear of ultra-high-molecular-weight polyethylene is unknown. In this study, third-body damage to cobalt chrome counterfaces was simulated using particles of the calcium sulfate bone void fillers Stimulan® (Biocomposites Ltd., Keele, UK) and Osteoset® (Wright Medical Technology, TN, USA) using a bespoke rig. Scratches on the cobalt chrome plates were quantified in terms of their density and mean lip height, and the damage caused by the bone void fillers was compared to that caused by particles of SmartSet GMV PMMA bone cement (DePuy Synthes, IN, USA). The surface damage from Stimulan® was below the resolution of the analysis technique used; SmartSet GMV caused 0.19 scratches/mm with a mean lip height of 0.03 µm; Osteoset® led to a significantly higher number (1.62 scratches/mm) of scratches with a higher mean lip height (0.04 µm). Wear tests of ultra-high-molecular-weight polyethylene were carried out in a six-station multi-axial pin on plate reciprocating rig against the damaged plates and compared to negative (highly polished) and positive control plates damaged with a diamond stylus (2 µm lip height). The wear of ultra-high-molecular-weight polyethylene was shown to be similar against the negative control plates and those damaged with third-body particles; there was a significantly higher (p < 0.001) rate of ultra-high-molecular-weight polyethylene wear against the positive control plates. This study showed that bone void fillers of similar composition can cause varying damage to cobalt chrome counterfaces. However, the lip heights of the scratches were not of sufficient magnitude to increase the wear of ultra-high-molecular-weight polyethylene above that of the negative controls. PMID:27312481

Salt stress causes cell wall damage in yeast cells lacking mitochondrial DNA.

PubMed

Gao, Qiuqiang; Liou, Liang-Chun; Ren, Qun; Bao, Xiaoming; Zhang, Zhaojie

2014-03-03

The yeast cell wall plays an important role in maintaining cell morphology, cell integrity and response to environmental stresses. Here, we report that salt stress causes cell wall damage in yeast cells lacking mitochondrial DNA (ρ 0 ). Upon salt treatment, the cell wall is thickened, broken and becomes more sensitive to the cell wall-perturbing agent sodium dodecyl sulfate (SDS). Also, SCW11 mRNA levels are elevated in ρ 0 cells. Deletion of SCW11 significantly decreases the sensitivity of ρ 0 cells to SDS after salt treatment, while overexpression of SCW11 results in higher sensitivity. In addition, salt stress in ρ 0 cells induces high levels of reactive oxygen species (ROS), which further damages the cell wall, causing cells to become more sensitive towards the cell wall-perturbing agent.

An opportunistic Pantoea sp. isolated from a cotton fleahopper that is capable of causing cotton (Gossypium hirsutum L.) bud rot

USDA-ARS?s Scientific Manuscript database

Pantoea ananatis (Serano) representatives are known to have a broad host range including both humans and plants. The cotton fleahopper (Pseudatomoscelis seriatus, Reuter) is a significant pest that causes cotton bud damage that may result in significant yield losses. In this study, cotton fleahopp...

Exposure to Cooking Oil Fumes and Oxidative Damages: A Longitudinal Study in Chinese Military Cooks

PubMed Central

Lai, Ching-Huang; Jaakkola, Jouni J.K.; Chuang, Chien-Yi; Liou, Saou-Hsing; Lung, Shih-Chun; Loh, Ching-Hui; Yu, Dah-Shyong; Strickland, Paul T.

2014-01-01

Cooking oil fumes contain polycyclic aromatic hydrocarbons (PAHs), heterocyclic aromatic amines, benzene, and formaldehyde which may cause oxidative damages to DNA and lipids. We assessed the relations between exposure to cooking oil fumes (COF) and subsequent oxidative DNA damage and lipid peroxidation among military cooks and office-based soldiers. The study population, including 61 Taiwanese male military cooks and a reference group of 37 office soldiers, collected urine samples pre-shift of the first weekday and post-shift of the fifth workday. We measured airborne particulate PAHs in military kitchens and offices and concentrations of urinary 1-OHP, a biomarker of PAH exposure, urinary 8-hydroxydeoxyguanosine (8-OHdG), a biomarkers of oxidative DNA damage, and urinary isoprostane (Isop). Airborne particulate PAHs levels in kitchens significantly exceeded those in office areas. The concentrations of urinary 1-OHP among military cooks increased significantly after 5 days of exposure to COF. Using generalized estimating equation (GEE) analysis adjusting for confounding, a change in log(8-OHdG) and log(Isop) were statistically significantly related to a unit change in log(1-OHP) (regression coefficient [β], β= 0.06, 95% CI 0.001 to 0.12) and (β= 0.07, 95% CI 0.001 to 0.13), respectively. Exposure to PAHs, or other compounds in cooking-oil fumes, may cause both oxidative DNA damage and lipid peroxidation. PMID:22968348

Exposure to cooking oil fumes and oxidative damages: a longitudinal study in Chinese military cooks.

PubMed

Lai, Ching-Huang; Jaakkola, Jouni J K; Chuang, Chien-Yi; Liou, Saou-Hsing; Lung, Shih-Chun; Loh, Ching-Hui; Yu, Dah-Shyong; Strickland, Paul T

2013-01-01

Cooking oil fumes (COF) contain polycyclic aromatic hydrocarbons (PAHs), heterocyclic aromatic amines, benzene, and formaldehyde, which may cause oxidative damages to DNA and lipids. We assessed the relations between exposure to COF and subsequent oxidative DNA damage and lipid peroxidation among military cooks and office-based soldiers. The study population, including 61 Taiwanese male military cooks and a reference group of 37 office soldiers, collected urine samples pre-shift of the first weekday and post-shift of the fifth workday. We measured airborne particulate PAHs in military kitchens and offices and concentrations of urinary 1-OHP, a biomarker of PAH exposure, urinary 8-hydroxydeoxyguanosine (8-OHdG), a biomarkers of oxidative DNA damage, and urinary isoprostane (Isop). Airborne particulate PAHs levels in kitchens significantly exceeded those in office areas. The concentrations of urinary 1-OHP among military cooks increased significantly after 5 days of exposure to COF. Using generalized estimating equation analysis adjusting for confounding, a change in log(8-OHdG) and log(Isop) were statistically significantly related to a unit change in log(1-OHP) (regression coefficient (β), β=0.06, 95% CI 0.001-0.12) and (β=0.07, 95% CI 0.001-0.13), respectively. Exposure to PAHs, or other compounds in cooking oil fumes, may cause both oxidative DNA damage and lipid peroxidation.

The effects of chronic intracortical microstimulation on neural tissue and fine motor behavior

NASA Astrophysics Data System (ADS)

Rajan, Alexander T.; Boback, Jessica L.; Dammann, John F.; Tenore, Francesco V.; Wester, Brock A.; Otto, Kevin J.; Gaunt, Robert A.; Bensmaia, Sliman J.

2015-12-01

Objective. One approach to conveying sensory feedback in neuroprostheses is to electrically stimulate sensory neurons in the cortex. For this approach to be viable, it is critical that intracortical microstimulation (ICMS) causes minimal damage to the brain. Here, we investigate the effects of chronic ICMS on the neuronal tissue across a variety of stimulation regimes in non-human primates. We also examine each animal’s ability to use their hand—the cortical representation of which is targeted by the ICMS—as a further assay of possible neuronal damage. Approach. We implanted electrode arrays in the primary somatosensory cortex of three Rhesus macaques and delivered ICMS four hours per day, five days per week, for six months. Multiple regimes of ICMS were delivered to investigate the effects of stimulation parameters on the tissue and behavior. Parameters included current amplitude (10-100 μA), pulse train duration (1, 5 s), and duty cycle (1/1, 1/3). We then performed a range of histopathological assays on tissue near the tips of both stimulated and unstimulated electrodes to assess the effects of chronic ICMS on the tissue and their dependence on stimulation parameters. Main results. While the implantation and residence of the arrays in the cortical tissue did cause significant damage, chronic ICMS had no detectable additional effect; furthermore, the animals exhibited no impairments in fine motor control. Significance. Chronic ICMS may be a viable means to convey sensory feedback in neuroprostheses as it does not cause significant damage to the stimulated tissue.

Descriptive study of damage caused by the rhinoceros beetle, Oryctes agamemnon, and its influence on date palm oases of Rjim Maatoug, Tunisia.

PubMed

Soltani, Rasmi; Lkbel, Chaieb; Habib Ben Hamouda, Med

2008-01-01

Oryctes agamemnon (Burmeister 1847) (Coleoptera, Scarabaeidae) was accidentally introduced in the southwestern oases of Tunisia (Tozeur) around 1980 and spread to the Rjim Maatoug region. In these areas O. agamemnon was specific to date palm trees causing severe damage that can result in potential danger due to collapse of the tree. This study was conducted from April 2004 to March 2006 in 4 sites in the region of Rjim Maatoug. Different levels of palm tree attack were determined, ovioposition sites were identified, and pest damage was described in detail to specify their relative importance and to indicate factors governing palm tree attack. Eggs were individually oviposited in the attacked parts. Dead parts of palm trees were the main target of O. agamemnon including the respiratory roots, tough, trunk bark, dry petiole and the periphery of the crown. The crown itself was not attacked. Feeding by larvae caused significant damage. The biggest danger occurred when heavy attacks of larvae invaded the respiratory roots at the level of the soil, and secondarily on the periphery of the crown, which can result in fungal diseases. Several cases of Deglet Nour date palm tree collapse were caused by this pest in Rjim Maatoug. Attacks on other parts of the tree were without danger for the palm tree. In the absence of pest management, application of a quarantine program combined with field cultivation techniques could help farmers significantly decrease attack of O. agamemnon on palm trees.

Geospatial relationships of tree species damage caused by Hurricane Katrina in south Mississippi

Treesearch

Mark W. Garrigues; Zhaofei Fan; David L. Evans; Scott D. Roberts; William H. Cooke III

2012-01-01

Hurricane Katrina generated substantial impacts on the forests and biological resources of the affected area in Mississippi. This study seeks to use classification tree analysis (CTA) to determine which variables are significant in predicting hurricane damage (shear or windthrow) in the Southeast Mississippi Institute for Forest Inventory District. Logistic regressions...

6-Gingerol prevents MEHP-induced DNA damage in human umbilical vein endothelia cells.

PubMed

Yang, G; Gao, X; Jiang, L; Sun, X; Liu, X; Chen, M; Yao, X; Sun, Q; Wang, S

2017-11-01

Mono (2-ethylhexyl) phthalate (MEHP) is the principal metabolite of di (2-etylhexyl) phthalate, which is widely used as a plasticizer, especially in medical devices. MEHP has toxic effects on cardiovascular system. The aim of this study was to investigate the possibility that 6-gingerol may inhibit the oxidative DNA damage of MEHP in human umbilical vein endothelial cells (HUVECs) and the potential mechanism. The comet assay was used to monitor DNA strand breaks. We have shown that 6-gingerol significantly reduced the DNA strand breaks caused by MEHP. MEHP increased the levels of reactive oxygen species and malondialdehyde, decreased the level of glutathione and activity of superoxide dismutase, and altered the mitochondrial membrane potential. In addition, DNA damage-associated proteins (p53 and p-Chk2 (T68)) were significantly increased by the treatment of MEHP. Those effects can all be protected by 6-gingerol. The results firmly indicate that 6-gingerol may have a strong protective ability against the DNA damage caused by MEHP in HUVECs, and the mechanism may relate to the antioxidant activity.

Lycium barbarum polysaccharide protects human keratinocytes against UVB-induced photo-damage.

PubMed

Li, Huaping; Li, Zhenjie; Peng, Liqian; Jiang, Na; Liu, Qing; Zhang, Erting; Liang, Bihua; Li, Runxiang; Zhu, Huilan

2017-02-01

Ultraviolet B (UVB) irradiation plays a key role in skin damage, which induces oxidative and inflammatory damages, thereby causing photoaging or photocarcinogenesis. Lycium barbarum polysaccharide (LBP), the most biologically active fraction of wolfberry, possesses significant antioxidative and anti-inflammatory effects on multiple tissues. In the present study, the photoprotective effects and potential underlying molecular mechanisms of LBP against UVB-induced photo-damage were investigated in immortalized human keratinocytes (HaCaT cells). The data indicated that pretreatment with LBP significantly attenuated UVB-induced decrease in cell viability, increase in ROS production and DNA damage. LBP also significantly suppressed UVB-induced p38 MAPK activation, and subsequently reversed caspase-3 activation and MMP-9 expression. Notably, LBP was found to induce Nrf2 nuclear translocation and increase the expression of Nrf2-dependent ARE target genes. Furthermore, the protective effects of LBP were abolished by siRNA-mediated Nrf2 silencing. These results showed that the antioxidant LBP could partially protect against UVB irradiation-induced photo-damage through activation of Nrf2/ARE pathway, thereby scavenging ROS and reducing DNA damage, and subsequently suppressing UVB-induced p38 MAP pathway. Thus, LBP can be potentially used for skincare against oxidative damage from environmental insults.

Genotoxic and cytotoxic effects of doxorubicin and silymarin on human hepatocellular carcinoma cells.

PubMed

Yurtcu, E; İşeri, Öd; Sahin, Fi

2014-12-01

The aim of this study was to investigate genotoxic and cytotoxic effects of doxorubicin, silymarin, or in combination on HepG2 cells for 24 and 48 h. Both doxorubicin and silymarin caused dose-dependent inhibition of cell proliferation. After 48 h of treatment, doxorubicin application caused dramatically increased ratio of apoptotic cells. Both 24 and 48 h of silymarin and doxorubicin-silymarin combination caused significant increases in the rate of apoptotic cells. Applications of doxorubicin and silymarin separately for 24 h led to deoxyribonucleic acid (DNA) damages. After 48 h of incubation, doxorubicin-induced genotoxic damage was 2-fold higher than the silymarin-induced damage. After 24 and 48 h, DNA damage in response to combined applications of doxorubicin and silymarin was indifferent from silymarin- and doxorubicin-induced damage respectively. There was not any difference in genotoxicity levels between incubation periods in combined applications of doxorubicin and silymarin. Lipid peroxidation levels increased in all applications. Biopharmacotherapy with chemotherapeutic agents are of interest in the issue of adjuvant therapy. Here, we demonstrate in vitro potential genotoxic and cytotoxic antitumor effect of silymarin on HepG2 cells at achievable plasma level concentrations. © The Author(s) 2014.

Toward resolving an earthquake ground motion mystery in west Seattle, Washington State: Shallow seismic focusing may cause anomalous chimney damage

USGS Publications Warehouse

Stephenson, W.J.; Frankel, A.D.; Odum, J.K.; Williams, R.A.; Pratt, T.L.

2006-01-01

A shallow bedrock fold imaged by a 1.3-km long high-resolution shear-wave seismic reflection profile in west Seattle focuses seismic waves arriving from the south. This focusing may cause a pocket of amplified ground shaking and the anomalous chimney damage observed in earthquakes of 1949, 1965 and 2001. The 200-m bedrock fold at ???300-m depth is caused by deformation across an inferred fault within the Seattle fault zone. Ground motion simulations, using the imaged geologic structure and northward-propagating north-dipping plane wave sources, predict a peak horizontal acceleration pattern that matches that observed in strong motion records of the 2001 Nisqually event. Additionally, a pocket of chimney damage reported for both the 1965 and the 2001 earthquakes generally coincides with a zone of simulated amplification caused by focusing. This study further demonstrates the significant impact shallow (<1km) crustal structures can have on earthquake ground-motion variability.

Bibliography of forest water yields, flooding issues, and the hydrologic modeling of extreme flood events

Treesearch

Mark H. Eisenbies; M.B. Adams; W. Michael Aust; James A. Burger

2007-01-01

Floods continue to cause significant damage in the United States and elsewhere, and questions about the causes of flooding continue to be debated. A significant amount of research has been conducted on the relationship between forest management activities and water yield, peak flows, and flooding; somewhat less research has been conducted on the modeling of these...

Flexible, multi-measurement guided wave damage detection under varying temperatures

NASA Astrophysics Data System (ADS)

Douglass, Alexander C. S.; Harley, Joel B.

2018-04-01

Temperature compensation in structural health monitoring helps identify damage in a structure by removing data variations due to environmental conditions, such as temperature. Stretch-based methods are one of the most commonly used temperature compensation methods. To account for variations in temperature, stretch-based methods optimally stretch signals in time to optimally match a measurement to a baseline. All of the data is then compared with the single baseline to determine the presence of damage. Yet, for these methods to be effective, the measurement and the baseline must satisfy the inherent assumptions of the temperature compensation method. In many scenarios, these assumptions are wrong, the methods generate error, and damage detection fails. To improve damage detection, a multi-measurement damage detection method is introduced. By using each measurement in the dataset as a baseline, error caused by imperfect temperature compensation is reduced. The multi-measurement method increases the detection effectiveness of our damage metric, or damage indicator, over time and reduces the presence of additional peaks caused by temperature that could be mistaken for damage. By using many baselines, the variance of the damage indicator is reduced and the effects from damage are amplified. Notably, the multi-measurement improves damage detection over single-measurement methods. This is demonstrated through an increase in the maximum of our damage signature from 0.55 to 0.95 (where large values, up to a maximum of one, represent a statistically significant change in the data due to damage).

[Disorders of emotional control in schizophrenia and unilateral brain damage].

PubMed

Kucharska-Pietura, K; Kopacz, G

2001-01-01

Although, emotions play a crucial role in schizophrenia, the changes in emotional dimension still remain controversial. The aim of our work was: 1) to compare the disorders of emotional control between the examined groups: S--non-chronic schizophrenic patients (n = 50), CS--chronic schizophrenic patients (n = 50), N--healthy controls (n = 50), R--right brain-damaged patients (n = 30), and L--left brain-damaged patients (n = 30), 2) to assess a level of impairment of emotional control, its relation to lateralised hemisphere damage and chronicity of schizophrenic process. All psychiatric subjects were diagnosed as paranoid schizophrenics according to DSM-IV criteria and were scored on the PANSS scale after four weeks of neuroleptic treatment. Brain-damaged patients were included if they experienced single-episode cerebrovascular accidents causing right or left hemisphere damage (confirmed in CT scan reports). The neurological patients were examined at least 3 weeks after the onset of cerebrovascular episode. Emotional control was assessed using Brzeziński Questionnaire of Emotional Control aimed at the evaluation of: 1) control in perception and interpretation of emotive situation, 2) emotional arousal, 3) emotional-rational motivation, and 4) acting caused by emotions. Our results revealed significantly greater impairment of emotional control in schizophrenics (chronic schizophrenics, in particular) compared to healthy volunteers. Chronicity of the schizophrenic process seemed to intensify emotional control impairment. Interestingly, no significant qualitative and quantitative differences in emotional control mechanism between unilateral brain-damaged patients and the control group were found.

Ozone Inhalation Leads to a Dose-Dependent Increase of Cytogenetic Damage in Human Lymphocytes

PubMed Central

Holland, Nina; Davé, Veronica; Venkat, Subha; Wong, Hofer; Donde, Aneesh; Balmes, John R; Arjomandi, Mehrdad

2014-01-01

Ozone is an important constituent of ambient air pollution and represents a major public health concern. Oxidative injury due to ozone inhalation causes the generation of reactive oxygen species and can be genotoxic. To determine whether ozone exposure causes genetic damage in peripheral blood lymphocytes, we employed a well-validated cytokinesis-block micronucleus Cytome assay. Frequencies of micronuclei (MN) and nucleoplasmic bridges (NB) were used as indicators of cytogenetic damage. Samples were obtained from 22 non-smoking healthy subjects immediately before and 24-hr after controlled 4-hr exposures to filtered air, 100 ppb, and 200 ppb ozone while exercising in a repeated-measure study design. Inhalation of ozone at different exposure levels was associated with a significant dose-dependent increase in MN frequency (P < 0.0001) and in the number of cells with more than 1 MN per cell (P < 0.0005). Inhalation of ozone also caused an increase in the number of apoptotic cells (P = 0.002). Airway neutrophilia was associated with an increase in MN frequency (P = 0.033) independent of the direct effects of ozone exposure (P < 0.0001). We also observed significant increases in both MN and NB frequencies after exercise in filtered air, suggesting that physical activity is also an important inducer of oxidative stress. These results corroborate our previous findings that cytogenetic damage is associated with ozone exposure, and show that damage is dose-dependent. Further study of ozone-induced cytogenetic damage in airway epithelial cells could provide evidence for the role of oxidative injury in lung carcinogenesis, and help to address the potential public health implications of exposures to oxidant environments. PMID:25451016

The HMDS Coating Flaw Removal Tool

DOE Office of Scientific and Technical Information (OSTI.GOV)

Monticelli, M V; Nostrand, M C; Mehta, N

2008-10-24

In many high energy laser systems, optics with HMDS sol gel antireflective coatings are placed in close proximity to each other making them particularly susceptible to certain types of strong optical interactions. During the coating process, halo shaped coating flaws develop around surface digs and particles. Depending on the shape and size of the flaw, the extent of laser light intensity modulation and consequent probability of damaging downstream optics may increase significantly. To prevent these defects from causing damage, a coating flaw removal tool was developed that deploys a spot of decane with a syringe and dissolves away the coatingmore » flaw. The residual liquid is evacuated leaving an uncoated circular spot approximately 1mm in diameter. The resulting uncoated region causes little light intensity modulation and thus has a low probability of causing damage in optics downstream from the mitigated flaw site.« less

[Reccurent mycobacterial diseases in patients with impaired axis IL-12/INF-gamma].

PubMed

Strach, Magdalena; Nalepa, Piotr; Sulicka-Grodzicka, Joanna; Kierzkowska, Izabella; Siedlar, Maciej; Grodzicki, Tomasz

2013-01-01

Mycobacteria is a large group of pathogens that are common in environment, in soil and tap water. Although mycobacteria [non tuberculosis mycobacteria] can inhabit body surface without causing any disease in the circumstances of primary or secondary immunodeficiency can cause clinically significant organ or systemic damage. Defect of IL-12/INFgamma axis is an example of primary immunodeficiency that predispose to mycobacterial infections while protection against other microorganisms is not damaged. We present review of known defects of IL-12/IFNgamma axis and brief presentation of our own experience.

Quantitation of Radiation Induced Deletion and Recombination Events Associated with Repeated DNA Sequences

NASA Technical Reports Server (NTRS)

Sinden, Richard R.

1999-01-01

Manned exploration of space exposes the explorers to a complex and novel radiation environment. The galactic cosmic ray and trapped belt radiation (predominantly proton) components of this environment are relatively constant, and the variations with the solar cycle are well understood and predictable. The level of radiation encountered in low earth orbits is determined by several factors, including altitude, inclination of orbit with respect to the equator, and spacecraft shielding. At higher altitudes, and on a Mars mission, the level of radiation exposure will increase significantly. A significant fraction of the dose may be delivered by solar particle events which vary dramatically in dose rate and incident particle spectrum. High-LET radiation is of particular concern. High-LET radiation, a component of galactic cosmic rays (GCR), is comprised of a variety of charged particles of various energies (10 MeV/n to 10 GeV/n), including about 87% photons, 12% helium ions, and heavy ions (including iron). These high energy particles can cause significant damage to target cells. The different particle types and energies result in different patterns of energy deposition at the molecular and cellular level in a primary target cell. They can also cause significant damage to other, nearby cells as a result of secondary particles. Protons, for instance produce secondaries that include photons, neutrons, pions, heavy particles, as well as gamma rays. Heavy ions deposit energy in a "track" in which the magnitude of the damage varies as the particle loses energy. Heavy ions produce secondary delta rays, or electrons. The distribution of damage through tissue is described by a Bragg curve which will be characteristic for different energies. Needless to say there are differences in the RBE of protons and a particles. High-LET heavy ions are particularly damaging to cells as they do continual damage throughout their track. Differences in these energy deposition patterns can significantly influence the nature of DNA damage and the ability of cellular systems to repair such damage. It has been suspected that these differences also affect the spatial distribution of damage within the DNA of the interphase cell nucleus and produce corresponding differences in endpoints related to health effects. The interaction of a single high-LET particle with chromatin has been suggested to cause multiple double strand breaks within a relatively short distance. In part this is due to the organization of DNA into chromatin fibers in which distant regions of the DNA helix can be physically juxtaposed by the various levels of coiling of the DNA. This prediction was confirmed by the detection of the generation of double strand DNA fragments of 100-2000 bp following exposure to high-LET ions (including iron).

Genotoxicity and oxidative stress in chromium-exposed tannery workers in North India.

PubMed

Ambreen, Khushboo; Khan, Faizan Haider; Bhadauria, Smrati; Kumar, Sudhir

2014-06-01

Trivalent chromium (Cr) is an environmental contaminant, which is extensively used in tanning industries throughout the world and causes various forms of health hazards in tannery workers. Therefore, a cross-sectional study design was used to evaluate the DNA damage and oxidative stress condition in tannery workers exposed to Cr in North India. The study population comprised 100 male tanners in the exposed group and 100 healthy males (no history of Cr exposure) in the comparable control group. Baseline characteristics including age, smoking, alcohol consumption habits and duration of exposure were recorded via interviewing the subjects. Blood Cr level (measured by atomic absorption spectrophotometry), DNA damage (measured by comet assay) and oxidative stress parameters (malondialdehyde (MDA), glutathione (GSH) and superoxide dismutase (SOD)) were estimated in both the groups. As a result of statistical analysis, exposed group showed significantly higher level of Cr (p < 0.0001), DNA damage (p < 0.0001), MDA (p < 0.0001), SOD (p < 0.05) and lower level of GSH (p < 0.001) when compared with controls. Smoking, alcohol consumption habits and age had no significant effect (p > 0.05) on DNA damage and oxidative stress parameters in both the groups. In simple and multiple correlation analysis, DNA damage and oxidative stress parameters showed significant correlation with Cr level and duration of exposure in exposed group. The findings of the present study revealed that chronic occupational exposure to trivalent Cr may cause DNA damage and oxidative stress in tannery workers. © The Author(s) 2012.

Phospholipid alterations in the brain and heart in a rat model of asphyxia-induced cardiac arrest and cardiopulmonary bypass resuscitation

PubMed Central

Kim, Junhwan; Lampe, Joshua W.; Yin, Tai; Shinozaki, Koichiro; Becker, Lance B.

2015-01-01

Cardiac arrest (CA) induces whole-body ischemia, causing damage to multiple organs. Ischemic damage to the brain is mainly responsible for patient mortality. However, the molecular mechanism responsible for brain damage is not understood. Prior studies have provided evidence that degradation of membrane phospholipids plays key roles in ischemia/reperfusion injury. The aim of this study is to correlate organ damage to phospholipid alterations following 30 min asphyxia-induced CA or CA followed by cardiopulmonary bypass (CPB) resuscitation using a rat model. Following 30 min CA and CPB resuscitation, rats showed no brain function, moderately compromised heart function, and died within a few hours; typical outcomes of severe CA. However, we did not find any significant change in the content or composition of phospholipids in either tissue following 30 min CA or CA followed by CPB resuscitation. We found a moderate increase in lysophosphatidylinositol in both tissues, and a small increase in lysophosphatidylethanolamine and lysophosphatidylcholine only in brain tissue following CA. CPB resuscitation significantly decreased lysophosphatidylinositol but did not alter the other lyso species. These results indicate that a decrease in phospholipids is not a cause of brain damage in CA or a characteristic of brain ischemia. However, a significant increase in lysophosphatidylcholine and lysophosphatidylethanolamine found only in the brain with more damage suggests that impaired phospholipid metabolism may be correlated with the severity of ischemia in CA. In addition, the unique response of lysophosphatidylinositol suggests that phosphatidylinositol metabolism is highly sensitive to cellular conditions altered by ischemia and resuscitation. PMID:26160279

Phospholipid alterations in the brain and heart in a rat model of asphyxia-induced cardiac arrest and cardiopulmonary bypass resuscitation.

PubMed

Kim, Junhwan; Lampe, Joshua W; Yin, Tai; Shinozaki, Koichiro; Becker, Lance B

2015-10-01

Cardiac arrest (CA) induces whole-body ischemia, causing damage to multiple organs. Ischemic damage to the brain is mainly responsible for patient mortality. However, the molecular mechanism responsible for brain damage is not understood. Prior studies have provided evidence that degradation of membrane phospholipids plays key roles in ischemia/reperfusion injury. The aim of this study is to correlate organ damage to phospholipid alterations following 30 min asphyxia-induced CA or CA followed by cardiopulmonary bypass (CPB) resuscitation using a rat model. Following 30 min CA and CPB resuscitation, rats showed no brain function, moderately compromised heart function, and died within a few hours; typical outcomes of severe CA. However, we did not find any significant change in the content or composition of phospholipids in either tissue following 30 min CA or CA followed by CPB resuscitation. We found a substantial increase in lysophosphatidylinositol in both tissues, and a small increase in lysophosphatidylethanolamine and lysophosphatidylcholine only in brain tissue following CA. CPB resuscitation significantly decreased lysophosphatidylinositol but did not alter the other lyso species. These results indicate that a decrease in phospholipids is not a cause of brain damage in CA or a characteristic of brain ischemia. However, a significant increase in lysophosphatidylcholine and lysophosphatidylethanolamine found only in the brain with more damage suggests that impaired phospholipid metabolism may be correlated with the severity of ischemia in CA. In addition, the unique response of lysophosphatidylinositol suggests that phosphatidylinositol metabolism is highly sensitive to cellular conditions altered by ischemia and resuscitation.

Mitigation of X-ray damage in macromolecular crystallography by submicrometre line focusing.

PubMed

Finfrock, Y Zou; Stern, Edward A; Alkire, R W; Kas, Joshua J; Evans-Lutterodt, Kenneth; Stein, Aaron; Duke, Norma; Lazarski, Krzysztof; Joachimiak, Andrzej

2013-08-01

Reported here are measurements of the penetration depth and spatial distribution of photoelectron (PE) damage excited by 18.6 keV X-ray photons in a lysozyme crystal with a vertical submicrometre line-focus beam of 0.7 µm full-width half-maximum (FWHM). The experimental results determined that the penetration depth of PEs is 5 ± 0.5 µm with a monotonically decreasing spatial distribution shape, resulting in mitigation of diffraction signal damage. This does not agree with previous theoretical predication that the mitigation of damage requires a peak of damage outside the focus. A new improved calculation provides some qualitative agreement with the experimental results, but significant errors still remain. The mitigation of radiation damage by line focusing was measured experimentally by comparing the damage in the X-ray-irradiated regions of the submicrometre focus with the large-beam case under conditions of equal exposure and equal volumes of the protein crystal, and a mitigation factor of 4.4 ± 0.4 was determined. The mitigation of radiation damage is caused by spatial separation of the dominant PE radiation-damage component from the crystal region of the line-focus beam that contributes the diffraction signal. The diffraction signal is generated by coherent scattering of incident X-rays (which introduces no damage), while the overwhelming proportion of damage is caused by PE emission as X-ray photons are absorbed.

Susceptibility and Interactions of Drosophila suzukii and Zaprionus indianus (Diptera: Drosophilidae) in Damaging Strawberry.

PubMed

Bernardi, D; Andreazza, F; Botton, M; Baronio, C A; Nava, D E

2017-02-01

Drosophila suzukii (Matsumura) has been recently detected causing damage to strawberries in Brazil. Infestation in strawberry culture has often been observed jointly with the presence of Zaprionus indianus Gupta. This study investigated the susceptibility of strawberries at three ripening stages to infestation of D. suzukii and Z. indianus and their interaction. In the laboratory, strawberries cv. Albion at different ripening stages (green, semi-ripe and ripe) were exposed to D. suzukii and Z. indianus for 24 h in choice and no-choice bioassays. Additionally, we evaluated the effects of mechanical damage incurred artificially or by D. suzukii oviposition on Z. indianus infestation. In no-choice bioassay, there were no significant differences in fruit susceptibility to D. suzukii infestation at different ripening stages. However, in choice bioassay, D. suzukii adults preferred to oviposit on R fruit. The presence of mechanical damage did not increase susceptibility of fruit to D. suzukii oviposition. For Z. indianus, there was greater susceptibility of R fruit in relation to SR and G fruit in both the choice and no-choice bioassays. There was a significant and positive interaction of mechanical damage and damage caused by D. suzukii to R fruit and infestation by Z. indianus, which was not observed in SR and G fruit. Although infestation of Z. indianus is related to attack damaged or decaying fruit, this work shows that this species has the ability to oviposit and develop in healthy strawberry fruit with and increased infestation level when the fruit has damage to its epidermis.

M. leprae components induce nerve damage by complement activation: identification of lipoarabinomannan as the dominant complement activator.

PubMed

Bahia El Idrissi, Nawal; Das, Pranab K; Fluiter, Kees; Rosa, Patricia S; Vreijling, Jeroen; Troost, Dirk; Morgan, B Paul; Baas, Frank; Ramaglia, Valeria

2015-05-01

Peripheral nerve damage is the hallmark of leprosy pathology but its etiology is unclear. We previously identified the membrane attack complex (MAC) of the complement system as a key determinant of post-traumatic nerve damage and demonstrated that its inhibition is neuroprotective. Here, we determined the contribution of the MAC to nerve damage caused by Mycobacterium leprae and its components in mouse. Furthermore, we studied the association between MAC and the key M. leprae component lipoarabinomannan (LAM) in nerve biopsies of leprosy patients. Intraneural injections of M. leprae sonicate induced MAC deposition and pathological changes in the mouse nerve, whereas MAC inhibition preserved myelin and axons. Complement activation occurred mainly via the lectin pathway and the principal activator was LAM. In leprosy nerves, the extent of LAM and MAC immunoreactivity was robust and significantly higher in multibacillary compared to paucibacillary donors (p = 0.01 and p = 0.001, respectively), with a highly significant association between LAM and MAC in the diseased samples (r = 0.9601, p = 0.0001). Further, MAC co-localized with LAM on axons, pointing to a role for this M. leprae antigen in complement activation and nerve damage in leprosy. Our findings demonstrate that MAC contributes to nerve damage in a model of M. leprae-induced nerve injury and its inhibition is neuroprotective. In addition, our data identified LAM as the key pathogen associated molecule that activates complement and causes nerve damage. Taken together our data imply an important role of complement in nerve damage in leprosy and may inform the development of novel therapeutics for patients.

Effect of saffron (Crocus sativus L.) on sodium valporate induced cytogenetic and testicular alterations in albino rats

PubMed Central

Zowail, Mohamed E.; Marzouk, Amera M.

2014-01-01

The present study investigated the cytogenetic and testicular damage induced by the antiepileptic drug, sodium valporate (SVP) in albino rats and the effect of saffron aqueous extracts. Treating rats with SVP caused a significant increase in the chromosomal aberrations either structural or numerical and decreased the mitotic index. Besides, animals administered SVP showed DNA damage appeared in the single strand breaks (comet assay). Testis of SVP-treated rats showed many histopathological changes. A significant decrease in seminiferous tubules and their epithelial heights diameters and inhibition of spermatogenesis was recorded. In addition, the number of sperm head abnormalities was increased. Biochemical results revealed an increase in malondialdhyde (MDA) which is lipid peroxidation marker and a significant decrease in the level of serum antioxidant enzyme, catalase (CAT) and reducing antioxidant power (RAP). Animals given SVP and saffron showed an improvement in chromosomal aberrations, mitotic index, DNA damage and testicular alterations caused by SVP. Moreover, MDA decreased and CAT and RAP increased. It is concluded from the present results that the ameliorative effects of saffron extract against SVP-induced cytogenetic and testicular damage in albino rats may be due to the presence of one or more antioxidant components of saffron. PMID:25276476

Conophthorin from almond host plant and fungal spores and its ecological relation to navel orangeworm: a natural products chemist's perspective

USDA-ARS?s Scientific Manuscript database

The navel orangeworm (Amyelois transitella) is a major insect pest that brings about significant monetary damage to California tree nuts – almonds, pistachios, and walnuts. During their development, larvae of navel orangeworm feed upon the meat of these nuts causing physical damage and ultimately lo...

Safeguarding world wheat and barley production against Russian wheat aphid: An international pre-breeding initiative

USDA-ARS?s Scientific Manuscript database

The Russian wheat aphid (RWA), Diuraphis noxia, is one of the most damaging insect pests of wheat and barley throughout the World. This aphid, although is not yet present in Australia, is extremely damaging with up to 70% yield loses in wheat and barley producing lands, causing significant financia...

Aflatoxin B₁-Induced Developmental and DNA Damage in Caenorhabditis elegans.

PubMed

Feng, Wei-Hong; Xue, Kathy S; Tang, Lili; Williams, Phillip L; Wang, Jia-Sheng

2016-12-26

Aflatoxin B₁ (AFB₁) is a ubiquitous mycotoxin produced by toxicogenic Aspergillus species. AFB₁ has been reported to cause serious adverse health effects, such as cancers and abnormal development and reproduction, in animals and humans. AFB₁ is also a potent genotoxic mutagen that causes DNA damage in vitro and in vivo. However, the link between DNA damage and abnormal development and reproduction is unclear. To address this issue, we examined the DNA damage, germline apoptosis, growth, and reproductive toxicity following exposure to AFB₁, using Caenorhabditis elegans as a study model. Results found that AFB₁ induced DNA damage and germline apoptosis, and significantly inhibited growth and reproduction of the nematodes in a concentration-dependent manner. Exposure to AFB₁ inhibited growth or reproduction more potently in the DNA repair-deficient xpa-1 nematodes than the wild-type N2 strain. According to the relative expression level of pathway-related genes measured by real-time PCR, the DNA damage response (DDR) pathway was found to be associated with AFB₁-induced germline apoptosis, which further played an essential role in the dysfunction of growth and reproduction in C. elegans .

Effect of cotton bollworm (Helicoverpa armigera Hübner) caused injury on maize grain content, especially regarding to the protein alteration.

PubMed

Keszthelyi, S; Pál-Fám, F; Kerepesi, I

2011-03-01

The cotton bollworm (Helicoverpa armigera Hübner), which migrated in the Carpathian-basin from Mediterraneum in the last decades, is becoming an increasingly serious problem for maize producers in Hungary. In several regions the damage it causes has reached the threshold of economic loss, especially in the case of the sweet maize cultivation. The aim of the research was to determine the changing of ears weights and in-kernel accumulation and alteration in grain as a function of cotton bollworm mastication.Our investigation confirmed that there is an in-kernel and protein pattern change of maize grain by cotton bollworm. Our results proved the significant damaging of each part of ears by cotton bollworm masticating (the average weight loss of ears: 13.99%; the average weight loss of grains: 14.03%; the average weight loss of cobs: 13.74%), with the exception of the increasing of the grain-cob ratio. Our examinations did not prove the water loss - that is the "forced maturing" - caused by the damage. Decreasing of raw fat (control: 2.8%; part-damaged: 2.6%; damaged: 2.4%) and starch content (control: 53.1%; part-damaged: 46.6%; damaged: 44.7%) were registered as a function of injury. In contrast, the raw protein content was increased (control: 4.7%; part-damaged: 5.3%; damaged: 7.4%) by maize ear masticating. The most conspicuous effect on protein composition changing was proved by comparison of damaged grain samples by SDS PAGE. Increased amounts of 114, 50, 46 and 35 kDa molecular mass proteins were detected which explained the more than 50% elevation of raw protein content. The statistical analysis of molecular weights proved the protein realignment as a function of the pest injuries, too.

Residual thermal stresses in composites for dimensionally stable spacecraft applications

NASA Technical Reports Server (NTRS)

Bowles, David E.; Tompkins, Stephen S.; Funk, Joan G.

1992-01-01

An overview of NASA LaRC's research on thermal residual stresses and their effect on the dimensional stability of carbon fiber reinforced polymer-matrix composites is presented. The data show that thermal residual stresses can induce damage in polymer matrix composites and significantly affect the dimensional stability of these composites by causing permanent residual strains and changes in CTE. The magnitude of these stresses is primarily controlled by the laminate configuration and the applied temperature change. The damage caused by thermal residual stresses initiates at the fiber/matrix interface and micromechanics level analyses are needed to accurately predict it. An increased understanding of fiber/matrix interface interactions appears to be the best approach for improving a composite's resistance to thermally induced damage.

Quantitative Evaluation of Hard X-ray Damage to Biological Samples using EUV Ptychography

NASA Astrophysics Data System (ADS)

Baksh, Peter; Odstrcil, Michal; Parsons, Aaron; Bailey, Jo; Deinhardt, Katrin; Chad, John E.; Brocklesby, William S.; Frey, Jeremy G.

2017-06-01

Coherent diffractive imaging (CDI) has become a standard method on a variety of synchrotron beam lines. The high brilliance short wavelength radiation from these sources can be used to reconstruct attenuation and relative phase of a sample with nanometre resolution via CDI methods. However, the interaction between the sample and high energy ionising radiation can cause degradation to sample structure. We demonstrate, using a laboratory based high harmonic generation (HHG) based extreme ultraviolet (EUV) source, imaging a sample of hippocampal neurons using the ptychography method. The significant increase in contrast of the sample in the EUV light allows identification of damage induced from exposure to 7.3 keV photons, without causing any damage to the sample itself.

18 CFR 12.35 - Specific inspection requirements.

Code of Federal Regulations, 2011 CFR

2011-04-01

... from monitoring instruments; and (vi) The quality and adequacy of maintenance, surveillance, and... life or cause significant property damage, the independent consultant must evaluate the ability of... endanger the project works. (2) If structural failure would not present a hazard to human life of cause...

18 CFR 12.35 - Specific inspection requirements.

Code of Federal Regulations, 2014 CFR

2014-04-01

... from monitoring instruments; and (vi) The quality and adequacy of maintenance, surveillance, and... life or cause significant property damage, the independent consultant must evaluate the ability of... endanger the project works. (2) If structural failure would not present a hazard to human life of cause...

Congenital Cytomegalovirus Infection: A Significant Cause of Deafness and Mental Deficiency.

ERIC Educational Resources Information Center

Eichhorn, Sarah K.

1982-01-01

Research on cytomegalovirus (CMV), a herpes virus causing neurological damage (hearing problems and/or mental retardation) in 10 percent of infants born with the condition, is reviewed. Incidence of hearing and retardation in CMV cases is reported and current treatment described. (CL)

Assessment of big floods in the Eastern Black Sea Basin of Turkey.

PubMed

Yüksek, Ömer; Kankal, Murat; Üçüncü, Osman

2013-01-01

In this study, general knowledge and some details of the floods in Eastern Black Sea Basin of Turkey are presented. Brief hydro-meteorological analysis of selected nine floods and detailed analysis of the greatest flood are given. In the studied area, 51 big floods have taken place between 1955-2005 years, causing 258 deaths and nearly US $500,000,000 of damage. Most of the floods have occurred in June, July and August. It is concluded that especially for the rainstorms that have caused significantly damages, the return periods of the rainfall heights and resultant flood discharges have gone up to 250 and 500 years, respectively. A general agreement is observed between the return periods of rains and resultant floods. It is concluded that there has been no significant climate change to cause increases in flood harms. The most important human factors to increase the damage are determined as wrong and illegal land use, deforestation and wrong urbanization and settlement, psychological and technical factors. Some structural and non-structural measures to mitigate flood damages are also included in the paper. Structural measures include dykes and flood levees. Main non-structural measures include flood warning system, modification of land use, watershed management and improvement, flood insurance, organization of flood management studies, coordination between related institutions and education of the people and informing of the stakeholders.

Antioxidant Protective Effect of Honey in Cigarette Smoke-Induced Testicular Damage in Rats

PubMed Central

Mohamed, Mahaneem; Sulaiman, Siti Amrah; Jaafar, Hasnan; Sirajudeen, Kuttulebbai Nainamohamed Salam

2011-01-01

Cigarette smoke (CS) can cause testicular damage and we investigated the possible protective effect of honey against CS-induced testicular damage and oxidative stress in rats. CS exposure (8 min, 3 times daily) and honey supplementation (1.2 g/kg daily) were given for 13 weeks. Rats exposed to CS significantly had smaller seminiferous tubules diameter and epithelial height, lower Leydig cell count and increased percentage of tubules with germ cell loss. CS also produced increased lipid peroxidation (TBARS) and glutathione peroxidase (GPx) activity, as well as reduced total antioxidant status (TAS) and activities of superoxide dismutase (SOD) and catalase (CAT). However, supplementation of honey significantly reduced histological changes and TBARS level, increased TAS level, as well as significantly restored activities of GPx, SOD and CAT in rat testis. These findings may suggest that honey has a protective effect against damage and oxidative stress induced by CS in rat testis. PMID:22016605

Antioxidant protective effect of honey in cigarette smoke-induced testicular damage in rats.

PubMed

Mohamed, Mahaneem; Sulaiman, Siti Amrah; Jaafar, Hasnan; Sirajudeen, Kuttulebbai Nainamohamed Salam

2011-01-01

Cigarette smoke (CS) can cause testicular damage and we investigated the possible protective effect of honey against CS-induced testicular damage and oxidative stress in rats. CS exposure (8 min, 3 times daily) and honey supplementation (1.2 g/kg daily) were given for 13 weeks. Rats exposed to CS significantly had smaller seminiferous tubules diameter and epithelial height, lower Leydig cell count and increased percentage of tubules with germ cell loss. CS also produced increased lipid peroxidation (TBARS) and glutathione peroxidase (GPx) activity, as well as reduced total antioxidant status (TAS) and activities of superoxide dismutase (SOD) and catalase (CAT). However, supplementation of honey significantly reduced histological changes and TBARS level, increased TAS level, as well as significantly restored activities of GPx, SOD and CAT in rat testis. These findings may suggest that honey has a protective effect against damage and oxidative stress induced by CS in rat testis.

Remtech SSME nozzle design TPS

NASA Technical Reports Server (NTRS)

Bancroft, Steven A.; Engel, Carl D.; Pond, John E.

1990-01-01

Thermal damage to the Space Shuttle Main Engine (SSME) aft manifold Thermal Protection System (TPS) has been observed for flights STS-8 through STS-13. This damaged area is located on the ME2 and ME3 and extends over a region of approximately one square foot. Total failure or burn-through of the TPS could lead to severe thermal damage of the SSME manifold and loss of an engine nozzle necessitating nozzle replacement causing significant schedule delays and cost increases. Thermal damage to the manifold can be defined as a situation where the manifold temperature becomes greater than 1300 F; thereby causing loss of heat treatment in the nozzle. Results of Orbiter/nozzle wind tunnel tests and Hot Gas Facility tests of the TPS are presented. Aerothermal and thermal analysis models for the SSME aft manifold are discussed along with the flight predictions, design trajectory and design environment. Finally, the TPS design concept and TPS thermal response are addressed.

Evaluation of the effects of intra-arterial sugammadex and dexmedetomidine: an experimental study.

PubMed

Hancı, Volkan; Özbilgin, Şule; Özbal, Seda; Kamacı, Gonca; Ateş, Hasan; Boztaş, Nilay; Ergür, Bekir Uğur; Arıkanoğlu, Ahmet; Yılmaz, Osman; Yurtlu, Bülent Serhan

2016-01-01

Intra-arterial injection of medications may cause acute and severe ischemia and result in morbidity and mortality. There is no information in the literature evaluating the arterial endothelial effects of sugammadex and dexmedetomidine. The hypothesis of our study is that sugammadex and dexmedetomidine will cause histological changes in arterial endothelial structure when administered intra-arterially. Rabbits were randomly divided into 4 groups. Group Control (n=7); no intervention performed. Group Catheter (n=7); a cannula inserted in the central artery of the ear, no medication was administered. Group Sugammadex (n=7); rabbits were given 4mg/kg sugammadex into the central artery of the ear, and Group Dexmedetomidine (n=7); rabbits were given 1μg/kg dexmedetomidine into the central artery of the ear. After 72h, the ears were amputated and histologically investigated. There was no significant difference found between the control and catheter groups in histological scores. The endothelial damage, elastic membrane and elastic fiber damage, smooth muscle hypertrophy and connective tissue increase scores in the dexmedetomidine and sugammadex groups were significantly higher than both the control and the catheter groups (p<0.05). There was no significant difference found between the dexmedetomidine and sugammadex groups in histological scores. Administration of sugammadex and dexmedetomidine to rabbits by intra-arterial routes caused histological arterial damage. To understand the histological changes caused by sugammadex and dexmedetomidine more clearly, more experimental research is needed. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

[Evaluation of the effects of intra-arterial sugammadex and dexmedetomidine: an experimental study].

PubMed

Hancı, Volkan; Özbilgin, Şule; Özbal, Seda; Kamacı, Gonca; Ateş, Hasan; Boztaş, Nilay; Ergür, Bekir Uğur; Arıkanoğlu, Ahmet; Yılmaz, Osman; Yurtlu, Bülent Serhan

2016-01-01

Intra-arterial injection of medications may cause acute and severe ischemia and result in morbidity and mortality. There is no information in the literature evaluating the arterial endothelial effects of sugammadex and dexmedetomidine. The hypothesis of our study is that sugammadex and dexmedetomidine will cause histological changes in arterial endothelial structure when administered intra-arterially. Rabbits were randomly divided into 4 groups. Group Control (n=7); no intervention performed. Group Catheter (n=7); a cannula inserted in the central artery of the ear, no medication was administered. Group Sugammadex (n=7); rabbits were given 4mg/kg sugammadex into the central artery of the ear, and Group Dexmedetomidine (n=7); rabbits were given 1μg/kg dexmedetomidine into the central artery of the ear. After 72h, the ears were amputated and histologically investigated. There was no significant difference found between the control and catheter groups in histological scores. The endothelial damage, elastic membrane and elastic fiber damage, smooth muscle hypertrophy and connective tissue increase scores in the dexmedetomidine and sugammadex groups were significantly higher than both the control and the catheter groups (p<0.05). There was no significant difference found between the dexmedetomidine and sugammadex groups in histological scores. Administration of sugammadex and dexmedetomidine to rabbits by intra-arterial routes caused histological arterial damage. To understand the histological changes caused by sugammadex and dexmedetomidine more clearly, more experimental research is needed. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Study on quantitative risk assessment model of the third party damage for natural gas pipelines based on fuzzy comprehensive assessment

NASA Astrophysics Data System (ADS)

Qiu, Zeyang; Liang, Wei; Wang, Xue; Lin, Yang; Zhang, Meng

2017-05-01

As an important part of national energy supply system, transmission pipelines for natural gas are possible to cause serious environmental pollution, life and property loss in case of accident. The third party damage is one of the most significant causes for natural gas pipeline system accidents, and it is very important to establish an effective quantitative risk assessment model of the third party damage for reducing the number of gas pipelines operation accidents. Against the third party damage accident has the characteristics such as diversity, complexity and uncertainty, this paper establishes a quantitative risk assessment model of the third party damage based on Analytic Hierarchy Process (AHP) and Fuzzy Comprehensive Evaluation (FCE). Firstly, risk sources of third party damage should be identified exactly, and the weight of factors could be determined via improved AHP, finally the importance of each factor is calculated by fuzzy comprehensive evaluation model. The results show that the quantitative risk assessment model is suitable for the third party damage of natural gas pipelines and improvement measures could be put forward to avoid accidents based on the importance of each factor.

Hair Shaft Damage from Heat and Drying Time of Hair Dryer

PubMed Central

Lee, Yoonhee; Kim, Youn-Duk; Hyun, Hye-Jin; Pi, Long-quan; Jin, Xinghai

2011-01-01

Background Hair dryers are commonly used and can cause hair damage such as roughness, dryness and loss of hair color. It is important to understand the best way to dry hair without causing damage. Objective The study assessed changes in the ultra-structure, morphology, moisture content, and color of hair after repeated shampooing and drying with a hair dryer at a range of temperatures. Methods A standardized drying time was used to completely dry each hair tress, and each tress was treated a total of 30 times. Air flow was set on the hair dryer. The tresses were divided into the following five test groups: (a) no treatment, (b) drying without using a hair dryer (room temperature, 20℃), (c) drying with a hair dryer for 60 seconds at a distance of 15 cm (47℃), (d) drying with a hair dryer for 30 seconds at a distance of 10 cm (61℃), (e) drying with a hair dryer for 15 seconds at a distance of 5 cm (95℃). Scanning and transmission electron microscopy (TEM) and lipid TEM were performed. Water content was analyzed by a halogen moisture analyzer and hair color was measured with a spectrophotometer. Results Hair surfaces tended to become more damaged as the temperature increased. No cortex damage was ever noted, suggesting that the surface of hair might play a role as a barrier to prevent cortex damage. Cell membrane complex was damaged only in the naturally dried group without hair dryer. Moisture content decreased in all treated groups compared to the untreated control group. However, the differences in moisture content among the groups were not statistically significant. Drying under the ambient and 95℃ conditions appeared to change hair color, especially into lightness, after just 10 treatments. Conclusion Although using a hair dryer causes more surface damage than natural drying, using a hair dryer at a distance of 15 cm with continuous motion causes less damage than drying hair naturally. PMID:22148012

Hematopoietic Stem Cell Injury Induced by Ionizing Radiation

PubMed Central

Shao, Lijian; Luo, Yi

2014-01-01

Abstract Significance: Exposure to ionizing radiation (IR) as the result of nuclear accidents or terrorist attacks is a significant threat and a major medical concern. Hematopoietic stem cell (HSC) injury is the primary cause of death after accidental or intentional exposure to a moderate or high dose of IR. Protecting HSCs from IR should be a primary goal in the development of novel medical countermeasures against radiation. Recent Advances: Significant progress has been made in our understanding of the mechanisms by which IR causes HSC damage. The mechanisms include (i) induction of HSC apoptosis via the p53-Puma pathway; (ii) promotion of HSC differentiation via the activation of the G-CSF/Stat3/BATF-dependent differentiation checkpoint; (iii) induction of HSC senescence via the ROS-p38 pathway; and (iv) damage to the HSC niche. Critical Issues: Induction of apoptosis in HSCs and hematopoietic progenitor cells is primarily responsible for IR-induced acute bone marrow (BM) injury. Long-term BM suppression caused by IR is mainly attributable to the induction of HSC senescence. However, the promotion of HSC differentiation and damage to the HSC niche can contribute to both the acute and long-term effects of IR on the hematopoietic system. Future Directions: In this review, we have summarized a number of recent findings that provide new insights into the mechanisms whereby IR damages HSCs. These findings will provide new opportunities for developing a mechanism-based strategy to prevent and/or mitigate IR-induced BM suppression. Antioxid. Redox Signal. 20, 1447–1462. PMID:24124731

Seismic behavior of an Italian Renaissance Sanctuary: Damage assessment by numerical modelling

NASA Astrophysics Data System (ADS)

Clementi, Francesco; Nespeca, Andrea; Lenci, Stefano

2016-12-01

The paper deals with modelling and analysis of architectural heritage through the discussion of an illustrative case study: the Medieval Sanctuary of Sant'Agostino (Offida, Italy). Using the finite element technique, a 3D numerical model of the sanctuary is built, and then used to identify the main sources of the damages. The work shows that advanced numerical analyses could offer significant information for the understanding of the causes of existing damage and, more generally, on the seismic vulnerability.

Effects of Lightning Injection on Power-MOSFETs

NASA Technical Reports Server (NTRS)

Celaya, Jose; Saha, Sankalita; Wysocki, Phil; Ely, Jay; Nguyen, Truong; Szatkowski, George; Koppen, Sandra; Mielnik, John; Vaughan, Roger; Goebel, Kai

2009-01-01

Lightning induced damage is one of the major concerns in aircraft health monitoring. Such short-duration high voltages can cause significant damage to electronic devices. This paper presents a study on the effects of lightning injection on power metal-oxide semiconductor field effect transistors (MOSFETs). This approach consisted of pin-injecting lightning waveforms into the gate, drain and/or source of MOSFET devices while they were in the OFF-state. Analysis of the characteristic curves of the devices showed that for certain injection modes the devices can accumulate considerable damage rendering them inoperable. Early results demonstrate that a power MOSFET, even in its off-state, can incur considerable damage due to lightning pin injection, leading to significant deviation in its behavior and performance, and to possibly early device failures.

Descriptive Study of Damage Caused by the Rhinoceros Beetle, Oryctes agamemnon, and Its Influence on Date Palm Oases of Rjim Maatoug, Tunisia

PubMed Central

Soltani, Rasmi; lkbel, Chaieb; Habib Ben Hamouda, Med

2008-01-01

Oryctes agamemnon (Burmeister 1847) (Coleoptera, Scarabaeidae) was accidentally introduced in the southwestern oases of Tunisia (Tozeur) around 1980 and spread to the Rjim Maatoug region. In these areas O. agamemnon was specific to date palm trees causing severe damage that can result in potential danger due to collapse of the tree. This study was conducted from April 2004 to March 2006 in 4 sites in the region of Rjim Maatoug. Different levels of palm tree attack were determined, ovioposition sites were identified, and pest damage was described in detail to specify their relative importance and to indicate factors governing palm tree attack. Eggs were individually oviposited in the attacked parts. Dead parts of palm trees were the main target of O. agamemnon including the respiratory roots, tough, trunk bark, dry petiole and the periphery of the crown. The crown itself was not attacked. Feeding by larvae caused significant damage. The biggest danger occurred when heavy attacks of larvae invaded the respiratory roots at the level of the soil, and secondarily on the periphery of the crown, which can result in fungal diseases. Several cases of Deglet Nour date palm tree collapse were caused by this pest in Rjim Maatoug. Attacks on other parts of the tree were without danger for the palm tree. In the absence of pest management, application of a quarantine program combined with field cultivation techniques could help farmers significantly decrease attack of O. agamemnon on palm trees. PMID:20302545

Staphylococcus Alpha-Toxin Action on the Rabbit Iris: Toxic Effects and Their Inhibition.

PubMed

Arana, Angela M; Bierdeman, Michael A; Balzli, Charles L; Tang, Aihua; Caballero, Armando R; Patel, Rupesh; O'Callaghan, Richard J

2015-01-01

Staphylococcus aureus infection of the anterior chamber can occur after cataract surgery, causing inflammation and extensive damage to the iris. Alpha-toxin, the most potent S. aureus corneal toxin, was tested as a possible mediator of damage to the iris, and alpha-toxin anti-serum and a chemical toxin inhibitor were tested as potential pathology-reducing agents. The hemolytic activity of alpha-toxin and its inhibition by a chemical inhibitor or anti-serum were quantified in vitro. Purified alpha-toxin, heat-inactivated toxin, or alpha-toxin plus normal serum, alpha-toxin anti-serum, or the chemical inhibitor, methyl-β-cyclodextrin-cholesterol (CD-cholesterol), was injected into the rabbit anterior chamber. Pathological changes were photographed, quantified by slit-lamp examination (SLE) scoring, and further documented by histopathological analysis. At five hours post-injection, eyes injected with alpha-toxin or heat-inactivated toxin had a mean SLE score of 7.3 ± 0.59 or 0.84 ± 0.19, respectively. Active toxin caused moderate to severe iris edema, severe erosion of the iris, and mild to moderate fibrin accumulation in the anterior chamber. Alpha-toxin plus anti-serum or CD-cholesterol, in contrast to alpha-toxin alone, caused less iris edema and epithelium sloughing as well as significantly lower SLE scores than eyes receiving alpha-toxin alone (p ≤ 0.019). Alpha-toxin caused extensive iris damage and inflammation, and either anti-alpha-toxin anti-serum or CD-cholesterol was able to significantly reduce toxin-mediated damage and inflammation.

Alkylation Damage by Lipid Electrophiles Targets Functional Protein Systems*

PubMed Central

Codreanu, Simona G.; Ullery, Jody C.; Zhu, Jing; Tallman, Keri A.; Beavers, William N.; Porter, Ned A.; Marnett, Lawrence J.; Zhang, Bing; Liebler, Daniel C.

2014-01-01

Protein alkylation by reactive electrophiles contributes to chemical toxicities and oxidative stress, but the functional impact of alkylation damage across proteomes is poorly understood. We used Click chemistry and shotgun proteomics to profile the accumulation of proteome damage in human cells treated with lipid electrophile probes. Protein target profiles revealed three damage susceptibility classes, as well as proteins that were highly resistant to alkylation. Damage occurred selectively across functional protein interaction networks, with the most highly alkylation-susceptible proteins mapping to networks involved in cytoskeletal regulation. Proteins with lower damage susceptibility mapped to networks involved in protein synthesis and turnover and were alkylated only at electrophile concentrations that caused significant toxicity. Hierarchical susceptibility of proteome systems to alkylation may allow cells to survive sublethal damage while protecting critical cell functions. PMID:24429493

Mechanisms of poliovirus inactivation by the direct and indirect effects of ionizing radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, R.L.

1980-08-01

This study was designed to measure the effects of ionizing radiation on poliovirus particles when given under conditions where either direct (in broth) or indirect (in water) effects were predominant. Under direct conditions, inactivation of poliovirus was found to be due primarily to RNA damage, although capsid damage could account for about one-third of the viral inactivation. RNA damage did not appear to be due to strand breakage and therefore was probably caused primarily by base damage or crosslink formation. Capsid damage under direct irradiation conditions did not result in significant alterations of either the sedimentation coefficients or the isoelectricmore » points of the poliovirus particles or detectable modification of the sizes of the viral proteins. It did, however, cause loss of availability to bind to host cells. Under indirect conditions no more than 25% of viral inactivation appeared to be due to RNA damage. However, the sedimentation coefficients and isoelectric points of the viral particles were greatly altered, and their abilities to bind to cells were lost at about three-fourths the rate of loss of infectivity. Capsid damage in this case did result in changes in the sizes of capsid proteins. Therefore, the majority of the radiation inactivation under indirect conditions appeared to be due to protein damage.« less

Damage Detection of a Concrete Column Subject to Blast Loads Using Embedded Piezoceramic Transducers.

PubMed

Xu, Kai; Deng, Qingshan; Cai, Lujun; Ho, Siuchun; Song, Gangbing

2018-04-28

Some of the most severe structural loadings come in the form of blast loads, which may be caused by severe accidents or even terrorist activities. Most commonly after exposure to explosive forces, a structure will suffer from different degrees of damage, and even progress towards a state of collapse. Therefore, damage detection of a structure subject to explosive loads is of importance. This paper proposes a new approach to damage detection of a concrete column structure subjected to blast loads using embedded piezoceramic smart aggregates (SAs). Since the sensors are embedded in the structure, the proposed active-sensing based approach is more sensitive to internal or through cracks than surface damage. In the active sensing approach, the embedded SAs act as actuators and sensors, that can respectively generate and detect stress waves. If the stress wave propagates across a crack, the energy of the wave attenuates, and the reduction of the energy compared to the healthy baseline is indicative of a damage. With a damage index matrix constructed by signals obtained from an array of SAs, cracks caused by blast loads can be detected throughout the structure. Conventional sensing methods such as the measurement of dynamic strain and acceleration were included in the experiment. Since columns are critical elements needed to prevent structural collapse, knowledge of their integrity and damage conditions is essential for safety after exposure to blast loads. In this research, a concrete column with embedded SAs was chosen as the specimen, and a series of explosive tests were conducted on the column. Experimental results reveal that surface damages, though appear severe, cause minor changes in the damage index, and through cracks result in significant increase of the damage index, demonstrating the effectiveness of the active sensing, enabled by embedded SAs, in damage monitoring of the column under blast loads, and thus providing a reliable indication of structural integrity in the event of blast loads.

Damage Detection of a Concrete Column Subject to Blast Loads Using Embedded Piezoceramic Transducers

PubMed Central

Deng, Qingshan; Cai, Lujun; Ho, Siuchun; Song, Gangbing

2018-01-01

Some of the most severe structural loadings come in the form of blast loads, which may be caused by severe accidents or even terrorist activities. Most commonly after exposure to explosive forces, a structure will suffer from different degrees of damage, and even progress towards a state of collapse. Therefore, damage detection of a structure subject to explosive loads is of importance. This paper proposes a new approach to damage detection of a concrete column structure subjected to blast loads using embedded piezoceramic smart aggregates (SAs). Since the sensors are embedded in the structure, the proposed active-sensing based approach is more sensitive to internal or through cracks than surface damage. In the active sensing approach, the embedded SAs act as actuators and sensors, that can respectively generate and detect stress waves. If the stress wave propagates across a crack, the energy of the wave attenuates, and the reduction of the energy compared to the healthy baseline is indicative of a damage. With a damage index matrix constructed by signals obtained from an array of SAs, cracks caused by blast loads can be detected throughout the structure. Conventional sensing methods such as the measurement of dynamic strain and acceleration were included in the experiment. Since columns are critical elements needed to prevent structural collapse, knowledge of their integrity and damage conditions is essential for safety after exposure to blast loads. In this research, a concrete column with embedded SAs was chosen as the specimen, and a series of explosive tests were conducted on the column. Experimental results reveal that surface damages, though appear severe, cause minor changes in the damage index, and through cracks result in significant increase of the damage index, demonstrating the effectiveness of the active sensing, enabled by embedded SAs, in damage monitoring of the column under blast loads, and thus providing a reliable indication of structural integrity in the event of blast loads. PMID:29710807

Exposure to nano-size titanium dioxide causes oxidative damages in human mesothelial cells: The crystal form rather than size of particle contributes to cytotoxicity.

PubMed

Hattori, Kenji; Nakadate, Kazuhiko; Morii, Akane; Noguchi, Takumi; Ogasawara, Yuki; Ishii, Kazuyuki

2017-10-14

Exposure to nanoparticles such as carbon nanotubes has been shown to cause pleural mesothelioma similar to that caused by asbestos, and has become an environmental health issue. Not only is the percutaneous absorption of nano-size titanium dioxide particles frequently considered problematic, but the possibility of absorption into the body through the pulmonary route is also a concern. Nevertheless, there are few reports of nano-size titanium dioxide particles on respiratory organ exposure and dynamics or on the mechanism of toxicity. In this study, we focused on the morphology as well as the size of titanium dioxide particles. In comparing the effects between nano-size anatase and rutile titanium dioxide on human-derived pleural mesothelial cells, the anatase form was shown to be actively absorbed into cells, producing reactive oxygen species and causing oxidative damage to DNA. In contrast, we showed for the first time that the rutile form is not easily absorbed by cells and, therefore, does not cause oxidative DNA damage and is significantly less damaging to cells. These results suggest that with respect to the toxicity of titanium dioxide particles on human-derived mesothelial cells, the crystal form rather than the particle size has a greater effect on cellular absorption. Also, it was indicated that the difference in absorption is the primary cause of the difference in the toxicity against mesothelial cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Out-of-plane properties

NASA Technical Reports Server (NTRS)

Jackson, Wade C.; Portanova, Marc A.

1995-01-01

This paper summarizes three areas of research which were performed to characterize out-of-plane properties of composite materials. In the first investigation, a series of tests was run to characterize the through-the-thickness tensile strength for a variety of composites that included 2D braids, 2D and 3D weaves, and prepreg tapes. A new test method based on a curved beam was evaluated. Failures were significantly different between the 2D materials and the 3D weaves. The 2D materials delaminated between layers due to out-of-plane tensile stresses while the 3D weaves failed due to the formation of radial cracks between the surface plies caused by high circumferential stresses along the inner radius. The strength of the 2D textile composites did not increase relative to the tapes. Final failure in the 3D weaves was caused by a circumferential crack similar to the 2D materials and occurred at a lower bending moment than in other materials. The early failures in the 3D weaves were caused by radial crack formation rather than a low through-the-thickness strength. The second investigation focused on the development of a standard impact test method to measure impact damage resistance. The only impact tests that currently exist are compression after impact (CAI) tests which incorporate elements of both damage resistance and damage tolerance. A new impact test method is under development which uses a quasi-static indentation (QSI) test to directly measure damage resistance. Damage resistance is quantified in terms of the contact force to produce a unit of damage where a metric for damage may be area in C-scan, depth of residual dent , penetration, damage growth, etc. A final draft of an impact standard that uses a QSI test method will be presented to the ASTM Impact Task Group on impact. In the third investigation, the impact damage resistance behavior of a variety of textile materials was studied using the QSI test method. In this study, the force where large damage initiates was measured and the delamination size as a function of force was determined. The force to initiate large damage was significantly lower in braids and weaves. The delamination diameter - impact forace relationship was quanitfied using a damage resistance parameter, Q(*), which related delamination diameter to imapct force over a range of delamination sizes. Using this Q(*) parameter to rate the materials, the stitched uniweaves, toughened epoxy tapes, and through-the-thickness orthogonal interlock weave were the most damage resistant.

Comparison of stainless and mild steel welding fumes in generation of reactive oxygen species.

PubMed

Leonard, Stephen S; Chen, Bean T; Stone, Samuel G; Schwegler-Berry, Diane; Kenyon, Allison J; Frazer, David; Antonini, James M

2010-11-03

Welding fumes consist of a wide range of complex metal oxide particles which can be deposited in all regions of the respiratory tract. The welding aerosol is not homogeneous and is generated mostly from the electrode/wire. Over 390,000 welders were reported in the U.S. in 2008 while over 1 million full-time welders were working worldwide. Many health effects are presently under investigation from exposure to welding fumes. Welding fume pulmonary effects have been associated with bronchitis, metal fume fever, cancer and functional changes in the lung. Our investigation focused on the generation of free radicals and reactive oxygen species from stainless and mild steel welding fumes generated by a gas metal arc robotic welder. An inhalation exposure chamber located at NIOSH was used to collect the welding fume particles. Our results show that hydroxyl radicals (.OH) were generated from reactions with H2O2 and after exposure to cells. Catalase reduced the generation of .OH from exposed cells indicating the involvement of H2O2. The welding fume suspension also showed the ability to cause lipid peroxidation, effect O2 consumption, induce H2O2 generation in cells, and cause DNA damage. Increase in oxidative damage observed in the cellular exposures correlated well with .OH generation in size and type of welding fumes, indicating the influence of metal type and transition state on radical production as well as associated damage. Our results demonstrate that both types of welding fumes are able to generate ROS and ROS-related damage over a range of particle sizes; however, the stainless steel fumes consistently showed a significantly higher reactivity and radical generation capacity. The chemical composition of the steel had a significant impact on the ROS generation capacity with the stainless steel containing Cr and Ni causing more damage than the mild steel. Our results suggest that welding fumes may cause acute lung injury. Since type of fume generated, particle size, and elapsed time after generation of the welding exposure are significant factors in radical generation and particle deposition these factors should be considered when developing protective strategies.

Comparison of stainless and mild steel welding fumes in generation of reactive oxygen species

PubMed Central

2010-01-01

Background Welding fumes consist of a wide range of complex metal oxide particles which can be deposited in all regions of the respiratory tract. The welding aerosol is not homogeneous and is generated mostly from the electrode/wire. Over 390,000 welders were reported in the U.S. in 2008 while over 1 million full-time welders were working worldwide. Many health effects are presently under investigation from exposure to welding fumes. Welding fume pulmonary effects have been associated with bronchitis, metal fume fever, cancer and functional changes in the lung. Our investigation focused on the generation of free radicals and reactive oxygen species from stainless and mild steel welding fumes generated by a gas metal arc robotic welder. An inhalation exposure chamber located at NIOSH was used to collect the welding fume particles. Results Our results show that hydroxyl radicals (.OH) were generated from reactions with H2O2 and after exposure to cells. Catalase reduced the generation of .OH from exposed cells indicating the involvement of H2O2. The welding fume suspension also showed the ability to cause lipid peroxidation, effect O2 consumption, induce H2O2 generation in cells, and cause DNA damage. Conclusion Increase in oxidative damage observed in the cellular exposures correlated well with .OH generation in size and type of welding fumes, indicating the influence of metal type and transition state on radical production as well as associated damage. Our results demonstrate that both types of welding fumes are able to generate ROS and ROS-related damage over a range of particle sizes; however, the stainless steel fumes consistently showed a significantly higher reactivity and radical generation capacity. The chemical composition of the steel had a significant impact on the ROS generation capacity with the stainless steel containing Cr and Ni causing more damage than the mild steel. Our results suggest that welding fumes may cause acute lung injury. Since type of fume generated, particle size, and elapsed time after generation of the welding exposure are significant factors in radical generation and particle deposition these factors should be considered when developing protective strategies. PMID:21047424

The natural product citral can cause significant damage to the hyphal cell walls of Magnaporthe grisea.

PubMed

Li, Rong-Yu; Wu, Xiao-Mao; Yin, Xian-Hui; Liang, Jing-Nan; Li, Ming

2014-07-15

In order to find a natural alternative to the synthetic fungicides currently used against the devastating rice blast fungus, Magnaporthe grisea, this study explored the antifungal potential of citral and its mechanism of action. It was found that citral not only inhibited hyphal growth of M. grisea, but also caused a series of marked hyphal morphological and structural alterations. Specifically, citral was tested for antifungal activity against M. grisea in vitro and was found to significantly inhibit colony development and mycelial growth with IC50 and IC90 values of 40.71 and 203.75 μg/mL, respectively. Furthermore, citral reduced spore germination and germ tube length in a concentration-dependent manner. Following exposure to citral, the hyphal cell surface became wrinkled with folds and cell breakage that were observed under scanning electron microscopy (SEM). There was damage to hyphal cell walls and membrane structures, loss of villous-like material outside of the cell wall, thinning of the cell wall, and discontinuities formed in the cell membrane following treatment based on transmission electron microscopy (TEM). This increase in chitinase activity both supports the morphological changes seen in the hyphae, and also suggests a mechanism of action. In conclusion, citral has strong antifungal properties, and treatment with this compound is capable of causing significant damage to the hyphal cell walls of M. grisea.

Health effects of acid aerosols formed by atmospheric mixtures.

PubMed Central

Kleinman, M T; Phalen, R F; Mautz, W J; Mannix, R C; McClure, T R; Crocker, T T

1989-01-01

Under ambient conditions, sulfur and nitrogen oxides can react with photochemical products and airborne particles to form acidic vapors and aerosols. Inhalation toxicological studies were conducted, exposing laboratory animals, at rest and during exercise, to multicomponent atmospheric mixtures under conditions favorable to the formation of acidic reaction products. Effects of acid and ozone mixtures on early and late clearance of insoluble radioactive particles in the lungs of rats appeared to be dominated by the oxidant component (i.e., the mixture did cause effects that were significantly different from those of ozone alone). Histopathological evaluations showed that sulfuric acid particles alone did not cause inflammatory responses in centriacinar units of rat lung parenchyma (expressed in terms of percent lesion area) but did cause significant damage (cell killing followed by a wave of cell replication) in nasal respiratory epithelium, as measured by uptake of tritiated thymidine in the DNA of replicating cells. Mixtures of ozone and nitrogen dioxide, which form nitric acid, caused significant inflammatory responses in lung parenchyma (in excess of effects seen in rats exposed to ozone alone), but did not damage nasal epithelium. Mixtures containing acidic sulfate particles, ozone, and nitrogen dioxide damaged both lung parenchyma and nasal epithelia. In rats exposed at rest, the response of the lung appeared to be dominated by the oxidant gas-phase components, while responses in the nose were dominated by the acidic particles. In rats exposed at exercise, however, mixtures of ozone and sulfuric acid particles significantly (2.5-fold) elevated the degree of lung lesion formation over that seen in rats exposed to ozone alone under an identical exercise protocol. PMID:2707193

New aspects in pathogenesis of konzo: neural cell damage directly caused by linamarin contained in cassava (Manihot esculenta Crantz).

PubMed

Sreeja, V G; Nagahara, N; Li, Q; Minami, M

2003-08-01

Epidemic spastic paraparesis (konzo) found in tropical and subtropical countries is known to be caused by long-term intake of cassava (Manihot esculenta Crantz), which contains a cyanoglucoside linamarin (alpha-hydroxyisobutyronitrile-beta-d-glucopyranoside). It has been reported that linamarin is enzymatically converted to cyanide by bacteria in the intestine, and this is absorbed into the blood and then damages neural cells. However, unmetabolized linamarin was found in the urine after oral administration of cassava; thus, we hypothesized that konzo could be caused by direct toxicity of the unmetabolized linamarin that was transferred to the brain and could be transported into neural cells via a glucose transporter. In the present study it was confirmed that linamarin directly damaged neural culture pheochromocytoma cell (PC) 12 cells; 0.10 mm-linamarin caused cell death at 13.31 (SD 2.07) %, which was significantly different from that of control group (3.18 (SD 0.92) %, P=0.0004). Additional 10 microM-cytochalasin B, an inhibitor of a glucose transporter, prevented cell death: the percentage of dead cells significantly decreased to 6.06 (SD 1.98), P=0.0088). Furthermore, glucose also prevented cell death. These present results strongly suggest that linamarin competes with cytochalasin B and glucose for binding to a glucose transporter and enters into cells via glucose transporter.

Lymphocyte DNA damage in Turkish asphalt workers detected by the comet assay.

PubMed

Bacaksiz, Aysegul; Kayaalti, Zeliha; Soylemez, Esma; Tutkun, Engin; Soylemezoglu, Tulin

2014-01-01

Asphalt has a highly complex structure and it contains several organic compounds including polycyclic aromatic hydrocarbons and heterocyclic compounds. In this study, comet assay was used to detect the DNA damage in blood lymphocytes of 30 workers exposed to asphalt fumes and 30 nonexposed controls. This is the first report on Turkish asphalt workers' investigated DNA damage using the alkaline single cell gel electrophoresis (SCGE). The DNA damage was evaluated by the percentage of DNA in the comet tail (% tail DNA) for each cell. According to our results, workers exposed to asphalt fumes had higher DNA damage than the control group (p < 0.01). The present study showed that asphalt fumes caused a significant increase in DNA damage and the comet assay is a suitable method for determining DNA damage in asphalt workers.

Retinal damage caused by air-fluid exchange during pars plana vitrectomy.

PubMed

Yang, Sam S; McDonald, H Richard; Everett, A I; Johnson, Robert N; Jumper, J Michael; Fu, Arthur D

2006-03-01

To report two cases of retinal damage associated with air infusion during pars plana vitrectomy. Observational case report. The authors reviewed the course of two patients who had retinal damage during par plana vitrectomy and air-fluid exchange for the treatment of macular hole and optic pit-related macular detachment, respectively. The intraoperative observations, postoperative course, and outcomes were reported. As a result of high air infusion flow during air-fluid exchange, retinal damage was created in the area contralateral to the infusion port. In Case 1, an oval area of whitening was noted on the first postoperative day. This area subsequently developed into a large retinal break associated with retinal detachment. In the second case, retinal whitening was noted intraoperatively. This region of pallor resolved quickly during the early postoperative period but resulted in a corresponding inferotemporal visual field defect. High infusion flow during air-fluid exchange in eyes undergoing vitrectomy surgery may result in significant retinal damage. This pressure-induced trauma initially causes retinal whitening that may be seen intraoperatively or during the early postoperative period. The region of damaged retina may develop a retinal break and detachment or a corresponding visual field defect.

Hematopoietic stem cell injury induced by ionizing radiation.

PubMed

Shao, Lijian; Luo, Yi; Zhou, Daohong

2014-03-20

Exposure to ionizing radiation (IR) as the result of nuclear accidents or terrorist attacks is a significant threat and a major medical concern. Hematopoietic stem cell (HSC) injury is the primary cause of death after accidental or intentional exposure to a moderate or high dose of IR. Protecting HSCs from IR should be a primary goal in the development of novel medical countermeasures against radiation. Significant progress has been made in our understanding of the mechanisms by which IR causes HSC damage. The mechanisms include (i) induction of HSC apoptosis via the p53-Puma pathway; (ii) promotion of HSC differentiation via the activation of the G-CSF/Stat3/BATF-dependent differentiation checkpoint; (iii) induction of HSC senescence via the ROS-p38 pathway; and (iv) damage to the HSC niche. Induction of apoptosis in HSCs and hematopoietic progenitor cells is primarily responsible for IR-induced acute bone marrow (BM) injury. Long-term BM suppression caused by IR is mainly attributable to the induction of HSC senescence. However, the promotion of HSC differentiation and damage to the HSC niche can contribute to both the acute and long-term effects of IR on the hematopoietic system. In this review, we have summarized a number of recent findings that provide new insights into the mechanisms whereby IR damages HSCs. These findings will provide new opportunities for developing a mechanism-based strategy to prevent and/or mitigate IR-induced BM suppression. Antioxid.

The effects of chronic intracortical microstimulation on neural tissue and fine motor behavior.

PubMed

Rajan, Alexander T; Boback, Jessica L; Dammann, John F; Tenore, Francesco V; Wester, Brock A; Otto, Kevin J; Gaunt, Robert A; Bensmaia, Sliman J

2015-12-01

One approach to conveying sensory feedback in neuroprostheses is to electrically stimulate sensory neurons in the cortex. For this approach to be viable, it is critical that intracortical microstimulation (ICMS) causes minimal damage to the brain. Here, we investigate the effects of chronic ICMS on the neuronal tissue across a variety of stimulation regimes in non-human primates. We also examine each animal's ability to use their hand--the cortical representation of which is targeted by the ICMS--as a further assay of possible neuronal damage. We implanted electrode arrays in the primary somatosensory cortex of three Rhesus macaques and delivered ICMS four hours per day, five days per week, for six months. Multiple regimes of ICMS were delivered to investigate the effects of stimulation parameters on the tissue and behavior. Parameters included current amplitude (10-100 μA), pulse train duration (1, 5 s), and duty cycle (1/1, 1/3). We then performed a range of histopathological assays on tissue near the tips of both stimulated and unstimulated electrodes to assess the effects of chronic ICMS on the tissue and their dependence on stimulation parameters. While the implantation and residence of the arrays in the cortical tissue did cause significant damage, chronic ICMS had no detectable additional effect; furthermore, the animals exhibited no impairments in fine motor control. Chronic ICMS may be a viable means to convey sensory feedback in neuroprostheses as it does not cause significant damage to the stimulated tissue.

Using the USGS Seismic Risk Web Application to estimate aftershock damage

USGS Publications Warehouse

McGowan, Sean M.; Luco, Nicolas

2014-01-01

The U.S. Geological Survey (USGS) Engineering Risk Assessment Project has developed the Seismic Risk Web Application to combine earthquake hazard and structural fragility information in order to calculate the risk of earthquake damage to structures. Enabling users to incorporate their own hazard and fragility information into the calculations will make it possible to quantify (in near real-time) the risk of additional damage to structures caused by aftershocks following significant earthquakes. Results can quickly be shared with stakeholders to illustrate the impact of elevated ground motion hazard and earthquake-compromised structural integrity on the risk of damage during a short-term, post-earthquake time horizon.

Examination of Physiological Function and Biochemical Disorders in a Rat Model of Prolonged Asphyxia-Induced Cardiac Arrest followed by Cardio Pulmonary Bypass Resuscitation

PubMed Central

Kim, Junhwan; Yin, Tai; Yin, Ming; Zhang, Wei; Shinozaki, Koichiro; Selak, Mary A.; Pappan, Kirk L.; Lampe, Joshua W.; Becker, Lance B.

2014-01-01

Background Cardiac arrest induces whole body ischemia, which causes damage to multiple organs particularly the heart and the brain. There is clinical and preclinical evidence that neurological injury is responsible for high mortality and morbidity of patients even after successful cardiopulmonary resuscitation. A better understanding of the metabolic alterations in the brain during ischemia will enable the development of better targeted resuscitation protocols that repair the ischemic damage and minimize the additional damage caused by reperfusion. Method A validated whole body model of rodent arrest followed by resuscitation was utilized; animals were randomized into three groups: control, 30 minute asphyxial arrest, or 30 minutes asphyxial arrest followed by 60 min cardiopulmonary bypass (CPB) resuscitation. Blood gases and hemodynamics were monitored during the procedures. An untargeted metabolic survey of heart and brain tissues following cardiac arrest and after CPB resuscitation was conducted to better define the alterations associated with each condition. Results After 30 min cardiac arrest and 60 min CPB, the rats exhibited no observable brain function and weakened heart function in a physiological assessment. Heart and brain tissues harvested following 30 min ischemia had significant changes in the concentration of metabolites in lipid and carbohydrate metabolism. In addition, the brain had increased lysophospholipid content. CPB resuscitation significantly normalized metabolite concentrations in the heart tissue, but not in the brain tissue. Conclusion The observation that metabolic alterations are seen primarily during cardiac arrest suggests that the events of ischemia are the major cause of neurological damage in our rat model of asphyxia-CPB resuscitation. Impaired glycolysis and increased lysophospholipids observed only in the brain suggest that altered energy metabolism and phospholipid degradation may be a central mechanism in unresuscitatable brain damage. PMID:25383962

Examination of physiological function and biochemical disorders in a rat model of prolonged asphyxia-induced cardiac arrest followed by cardio pulmonary bypass resuscitation.

PubMed

Kim, Junhwan; Yin, Tai; Yin, Ming; Zhang, Wei; Shinozaki, Koichiro; Selak, Mary A; Pappan, Kirk L; Lampe, Joshua W; Becker, Lance B

2014-01-01

Cardiac arrest induces whole body ischemia, which causes damage to multiple organs particularly the heart and the brain. There is clinical and preclinical evidence that neurological injury is responsible for high mortality and morbidity of patients even after successful cardiopulmonary resuscitation. A better understanding of the metabolic alterations in the brain during ischemia will enable the development of better targeted resuscitation protocols that repair the ischemic damage and minimize the additional damage caused by reperfusion. A validated whole body model of rodent arrest followed by resuscitation was utilized; animals were randomized into three groups: control, 30 minute asphyxial arrest, or 30 minutes asphyxial arrest followed by 60 min cardiopulmonary bypass (CPB) resuscitation. Blood gases and hemodynamics were monitored during the procedures. An untargeted metabolic survey of heart and brain tissues following cardiac arrest and after CPB resuscitation was conducted to better define the alterations associated with each condition. After 30 min cardiac arrest and 60 min CPB, the rats exhibited no observable brain function and weakened heart function in a physiological assessment. Heart and brain tissues harvested following 30 min ischemia had significant changes in the concentration of metabolites in lipid and carbohydrate metabolism. In addition, the brain had increased lysophospholipid content. CPB resuscitation significantly normalized metabolite concentrations in the heart tissue, but not in the brain tissue. The observation that metabolic alterations are seen primarily during cardiac arrest suggests that the events of ischemia are the major cause of neurological damage in our rat model of asphyxia-CPB resuscitation. Impaired glycolysis and increased lysophospholipids observed only in the brain suggest that altered energy metabolism and phospholipid degradation may be a central mechanism in unresuscitatable brain damage.

Using insurance data to learn more about damages to buildings caused by surface runoff

NASA Astrophysics Data System (ADS)

Bernet, Daniel; Roethlisberger, Veronika; Prasuhn, Volker; Weingartner, Rolf

2015-04-01

In Switzerland, almost forty percent of total insurance loss due to natural hazards in the last two decades was caused by flooding. Those flood damages occurred not only within known inundation zones of water courses. Practitioners expect that roughly half of all flood damages lie outside of known inundation zones. In urban areas such damages may simply be caused by drainage system overload for instance. However, as several case studies show, natural and agricultural land play a major role in surface runoff formation leading to damages in rural and peri-urban areas. Although many damages are caused by surface runoff, the whole process chain including surface runoff formation, propagation through the landscape and damages to buildings is not well understood. Therefore, within the framework of a project, we focus our research on this relevant process. As such flash flood events have a very short response time and occur rather diffusely in the landscape, this process is very difficult to observe directly. Therefore indirect data sources with the potential to indicate spatial and temporal distributions of the process have to be used. For that matter, post-flood damage data may be a profitable source. Namely, insurance companies' damage claim records could provide a good picture about the spatial and temporal distributions of damages caused by surface runoff and, thus, about the process itself. In our research we analyze insurance data records of flood damage claims systematically to infer main drivers and influencing factors of surface runoff causing damages to buildings. To demonstrate the potential and drawbacks of using data from insurance companies in relation to damages caused by surface runoff, a case study is presented. A well-documented event with data from a public as well as a private insurance company is selected. The case study focuses on the differences of the datasets as well as the associated problems and advantages respectively. Furthermore, the analysis of the data, especially the crucial identification of damages caused by surface runoff opposed to damages caused by other processes such as riverine flooding, drainage system surcharges etc. are discussed.

Hydrometeorological Hazards: Monitoring, Forecasting, Risk Assessment, and Socioeconomic Responses

NASA Technical Reports Server (NTRS)

Wu, Huan; Huang, Maoyi; Tang, Qiuhong; Kirschbaum, Dalia B.; Ward, Philip

2017-01-01

Hydrometeorological hazards are caused by extreme meteorological and climate events, such as floods, droughts, hurricanes,tornadoes, or landslides. They account for a dominant fraction of natural hazards and occur in all regions of the world, although the frequency and intensity of certain hazards and societies vulnerability to them differ between regions. Severe storms, strong winds, floods, and droughts develop at different spatial and temporal scales, but all can become disasters that cause significant infrastructure damage and claim hundreds of thousands of lives annually worldwide. Oftentimes, multiple hazards can occur simultaneously or trigger cascading impacts from one extreme weather event. For example, in addition to causing injuries, deaths, and material damage, a tropical storm can also result in flooding and mudslides, which can disrupt water purification and sewage disposal systems, cause overflow of toxic wastes, andincrease propagation of mosquito-borne diseases.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Huan; Huang, Maoyi; Tang, Qiuhong

Hydrometeorological hazards are caused by extreme meteorological and climate events, such as floods, droughts, hurricanes, tornadoes, or landslides. They account for a dominant fraction of natural hazards and occur in all regions of the world, although the frequency and intensity of certain hazards, and society’s vulnerability to them, differs between regions. Severe storms, strong winds, floods and droughts develop at different spatial and temporal scales, but all can become disasters that cause significant infrastructure damage and claim hundreds of thousands of lives annually worldwide. Oftentimes, multiple hazards can occur simultaneously or trigger cascading impacts from one extreme weather event. Formore » example, in addition to causing injuries, deaths and material damage, a tropical storm can also result in flooding and mudslides, which can disrupt water purification and sewage disposal systems, cause overflow of toxic wastes, and increase propagation of mosquito-borne diseases.« less

The Role of Topography in the Distribution and Intensity of Damage Caused by Deer in Polish Mountain Forests

PubMed Central

Ciesielski, Mariusz; Stereńczak, Krzysztof; Borowski, Zbigniew

2016-01-01

The increase in the deer population observed in recent decades has strongly impacted forest regeneration and the forest itself. The reduction in the quality of raw wood material, as a consequence of deer-mediated damage, constitutes a significant burden on forest owners. The basis for the commencement of preventive actions in this setting is the understanding of the populations and behaviors of deer in their natural environment. Although multiple studies have been carried out regarding this subject, only a few suggested topography as an important factor that may influence the distribution and intensity of deer-mediated damage. The detailed terrain models based on LiDAR data as well as the data on damage caused by deer from the State Forests database enabled thorough analyses of the distribution and intensity of damage in relation to land form in this study. These analyses were performed on three mountain regions in Poland: the Western Sudety Mountains, the Eastern Sudety Mountains, and the Beskidy Mountains. Even though these three regions are located several dozen to several hundred kilometers apart from each other, not all evaluated factors appeared common among them, and therefore, these regions have been analyzed separately. The obtained results indicated that the forest damage caused by deer increased with increasing altitude above 1000 m ASL. However, much larger areas of damage by deer were observed at elevations ranging from 401 to 1000 m ASL than at elevations below 400 m ASL. Moreover, the locations of damage (forest thickets and old stands) indicated that red deer is the species that exerts the strongest pressure on forest ecosystems. Our results show the importance of deer foraging behavior to the structure of the environment. PMID:27851776

Effects of water turbidity and different temperatures on oxidative stress in caddisfly (Stenopsyche marmorata) larvae.

PubMed

Suzuki, Jumpei; Imamura, Masahiro; Nakano, Daisuke; Yamamoto, Ryosuke; Fujita, Masafumi

2018-07-15

Anthropogenic water turbidity derived from suspended solids (SS) is caused by reservoir sediment management practices such as drawdown flushing. Turbid water induces stress in many aquatic organisms, but the effects of turbidity on oxidative stress responses in aquatic insects have not yet been demonstrated. Here, we examined antioxidant responses, oxidative damage, and energy reserves in caddisfly (Stenopsyche marmorata) larvae exposed to turbid water (0 mg SS L -1 , 500 mg SS L -1 , and 2000 mg SS L -1 ) at different temperatures. We evaluated the combined effects of turbid water and temperature by measuring oxidative stress and using metabolic biomarkers. No turbidity level was significantly lethal to S. marmorata larvae. Moreover, there were no significant differences in antioxidant response or oxidative damage between the control and turbid water treatments at a low temperature (10 °C). However, at a high temperature (25 °C), turbid water modulated the activity of the antioxidant enzymes superoxide dismutase and catalase and the oxygen radical absorbance capacity as an indicator of the redox state of the insect larvae. Antioxidant defenses require energy, and high temperature was associated with low energy reserves, which might limit the capability of organisms to counteract reactive oxygen species. Moreover, co-exposure to turbid water and high temperature caused fluctuation of antioxidant defenses and increased the oxidative damage caused by the production of reactive oxygen species. Furthermore, the combined effect of high temperature and turbid water on antioxidant defenses and oxidative damage was larger than the individual effects. Therefore, our results demonstrate that exposure to both turbid water and high temperature generates additive and synergistic interactions causing oxidative stress in this aquatic insect species. Copyright © 2018. Published by Elsevier B.V.

43 CFR 8341.1 - Regulations governing use.

Code of Federal Regulations, 2011 CFR

2011-10-01

... to cause significant, undue damage to or disturbance of the soil, wildlife, wildlife habitat, improvements, cultural, or vegetative resources or other authorized uses of the public lands; and (5) During...

Impact behavior of graphite-epoxy simulated fan blades

NASA Technical Reports Server (NTRS)

Cook, T. S.; Preston, J. L., Jr.

1977-01-01

The response of a graphite-epoxy material, Modmor II/PR-286, to foreign object impact was investigated by impacting spherical projectiles of three different materials - gelatin, ice, and steel - on simulated blade specimens. Visual and metallographic inspection revealed three damage mechanisms: penetration, leading edge bending failure, and stress wave delamination and cracking. The steel projectiles caused penetration damage regardless of the impact location and angle. For the ice and gelatin particles impacting the leading edge, failure was due to large local bending strains, resulting in significant material removal and delamination damage.

Development of novel force-limiting grasping forceps with a simple mechanism.

PubMed

Sakaguchi, Yasuto; Sato, Toshihiko; Yutaka, Yojiro; Muranishi, Yusuke; Komatsu, Teruya; Yoshizawa, Akihiko; Nakajima, Naoki; Nakamura, Tatsuo; Date, Hiroshi

2018-06-06

In endoscopic surgery, fragile tissues may be damaged by the application of excessive force. Thus, we developed novel endoscopic forceps with a simple force-limiting mechanism. The novel forceps were constructed with a leaf spring, and the spring thickness determines grasping pressure. We established an evaluation system (maximum score is 11 points) for lung tissue damage leading to complications. We tested the conventional forceps (186.8 kPa) and 3 novel spring forceps with the following thicknesses: 1.3 mm (53.0 kPa), 2.2 mm (187.7 kPa) and 2.8 mm (369.2 kPa). After grasping, peripheral canine lung tissues were microscopically examined for acute- and late-phase damages. In the acute phase (20 sites), the novel forceps caused capillary congestion and haemorrhage in the subpleural tissue, whereas the conventional forceps caused deep tissue and pleural damages. In the late phase (30 sites), both forceps caused fibroblast formation and interstitial thickening, which progressed to the deeper tissues as grasping pressure increased. In the acute phase, the median scores were 2.0 and 6.0 for the novel and conventional forceps, respectively (P = 0.003). In the late phase, the median scores were 2.0, 2.5 and 5.0 for 1.3-, 2.2- and 2.8-mm thick forceps, respectively, and 5.0 for the conventional forceps (P < 0.001). In both phases, the novel forceps with grasping pressure set below 187.7 kPa (2.2 mm) caused significantly less lung tissue damage than the conventional forceps. The novel endoscopic forceps are able to regulate the tissue-grasping pressure and induce less damage in lung tissues than conventional forceps.

Detection of DNA damage in oocytes of small ovarian follicles following phosphoramide mustard exposures of cultured rodent ovaries in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petrillo, Stephanie K.; Desmeules, Patrice; Truong, To-Quyen

2011-06-01

Healthy oocytes are critical for producing healthy children, but little is known about whether or not oocytes have the capacity to identify and recover from injury. Using a model ovotoxic alkylating drug, cyclophosphamide (CPA), and its active metabolite, phosphoramide mustard (PM), we previously showed that PM ({>=} 3 {mu}M) caused significant follicle loss in postnatal day 4 (PND4) mouse ovaries in vitro. We now investigate whether PM induces DNA damage in oocytes, examining histone H2AX phosphorylation ({gamma}H2AX), a marker of DNA double-strand breaks (DSBs). Exposure of cultured PND4 mouse ovaries to 3 and 0.1 {mu}M PM induced significant losses ofmore » primordial and small primary follicles, respectively. PM-induced {gamma}H2AX was observed predominantly in oocytes, in which foci of {gamma}H2AX staining increased in a concentration-dependent manner and peaked 18-24 h after exposure to 3-10 {mu}M PM. Numbers of oocytes with {>=} 5 {gamma}H2AX foci were significantly increased both 1 and 8 days after exposure to {>=} 1 {mu}M PM compared to controls. Inhibiting the kinases that phosphorylate H2AX significantly increased follicle loss relative to PM alone. In adult mice, CPA also induced follicle loss in vivo. PM also significantly decreased primordial follicle numbers ({>=} 30 {mu}M) and increased {gamma}H2AX foci ({>=} 3 {mu}M) in cultured PND4 Sprague-Dawley rat ovaries. Results suggest oocytes can detect PM-induced damage at or below concentrations which cause significant follicle loss, and there are quantitative species-specific differences in sensitivity. Surviving oocytes with DNA damage may represent an increased risk for fertility problems or unhealthy offspring.« less

Registration of an oilseed sunflower germplasm line HA-BSR1 highly tolerant to Sclerotinia basal stalk rot

USDA-ARS?s Scientific Manuscript database

Basal stalk rot (BSR) caused by Sclerotinia sclerotiorum (Lib.) de Bary is a devastating disease that causes a significant damage to worldwide sunflower (Helianthus annuus L.) production by reducing seed yield and quality. The objective of this research was to develop highly BSR tolerant sunflower g...

Seasonal occurrence and impact of Halyomorpha halys (Hemiptera: Pentatomidae) in tree fruit.

PubMed

Nielsen, Anne L; Hamilton, George C

2009-06-01

Halyomorpha halys is an introduced stink bug species from Asia that is spreading throughout the Mid-Atlantic United States. It is native to South Korea, Japan, and eastern China, where it is an occasional pest of tree fruit, including apple and pear. Cage experiments with adults placed on apple and peach during critical plant growth stages demonstrate that it can cause damage to developing fruit during mid- and late season growth periods and that feeding occurs on all regions of the fruit. Feeding that occurred during pit hardening/mid-season and final swell periods were apparent as damage at harvest, whereas feeding at shuck split/petal fall in peaches and apples caused fruit abscission. Tree fruit at two commercial farms were sampled weekly in 2006-2007 to determine H. halys seasonality. Low densities of nymphs in apple suggest that it is an unsuitable developmental host. Both nymphs and adults were found on pear fruits with peak populations occurring in early July and mid-August, the time when pit hardening/mid-season and swell period damage occurs. At both farms, stink bug damage was greater than 25% damaged fruit per tree. We attribute this to H. halys because population densities were significantly higher than native pentatomids at both locations in both beat samples and blacklight trap captures. The data presented here documents the potential for H. halys to cause damage in orchards throughout the Mid-Atlantic United States and shows the need for development of appropriate control strategies.

A Historical Analysis of Crane Mishaps at Kennedy Space Center

NASA Technical Reports Server (NTRS)

Wolfe, Crystal

2014-01-01

Cranes and hoists are widely used in many areas. Crane accidents and handling mishaps are responsible for injuries, costly equipment damage, and program delays. Most crane accidents are caused by preventable factors. Understanding these factors is critical when designing cranes and preparing lift plans. Analysis of previous accidents provides insight into current recommendations for crane safety. Cranes and hoists are used throughout Kennedy Space Center to lift everything from machine components to critical flight hardware. Unless they are trained crane operators, most NASA employees and contractors do not need to undergo specialized crane training and may not understand the safety issues surrounding the use of cranes and hoists. A single accident with a crane or hoist can injure or kill people, cause severe equipment damage, and delay or terminate a program. Handling mishaps can also have a significant impact on the program. Simple mistakes like bouncing or jarring a load, or moving the crane down when it should go up, can damage fragile flight hardware and cause major delays in processing. Hazardous commodities (high pressure gas, hypergolic propellants, and solid rocket motors) can cause life safety concerns for the workers performing the lifting operations. Most crane accidents are preventable with the correct training and understanding of potential hazards. Designing the crane with human factors taken into account can prevent many accidents. Engineers are also responsible for preparing lift plans where understanding the safety issues can prevent or mitigate potential accidents. Cranes are widely used across many areas of KSC. Failure of these cranes often leads to injury, high damage costs, and significant delays in program objectives. Following a basic set of principles and procedures during design, fabrication, testing, regular use, and maintenance can significantly minimize many of these failures. As the accident analysis shows, load drops are often caused or influenced by human factors. Therefore, proper training and understanding of crane safety throughout the workforce is critical. It is important that the engineers designing the cranes, lift planners preparing the lift plans, operators performing the lifts, and training officers conducting the operator training all understand the problems that can happen with cranes and how to ensure the safety of the workforce and equipment being lifted.

Preparing for a significant central U.S. earthquake : science needs of the emergency response community.

DOT National Transportation Integrated Search

2009-02-01

The New Madrid and Wabash Valley seismic zones are capable of producing large magnitude earthquakes that could cause significant damage and interrupt the east to west flow of transportation, communication, electricity, natural gas and oil across the ...

Detecting Tooth Damage in Geared Drive Trains

NASA Technical Reports Server (NTRS)

Nachtsheim, Philip R.

1997-01-01

This paper describes a method that was developed to detect gear tooth damage that does not require a priori knowledge of the frequency characteristic of the fault. The basic idea of the method is that a few damaged teeth will cause transient load fluctuations unlike the normal tooth load fluctuations. The method attempts to measure the energy in the lower side bands of the modulated signal caused by the transient load fluctuations. The method monitors the energy in the frequency interval which excludes the frequency of the lowest dominant normal tooth load fluctuation and all frequencies above it. The method reacted significantly to the tooth fracture damage results documented in the Lewis data sets which were obtained from tests of the OH-58A transmission and tests of high contact ratio spiral bevel gears. The method detected gear tooth fractures in all four of the high contact ratio spiral bevel gear runs. Published results indicate other detection methods were only able to detect faults for three out of four runs.

Determinants of spontaneous mutation in the bacterium Escherichia coli as revealed by whole-genome sequencing

PubMed Central

Foster, Patricia L.; Lee, Heewook; Popodi, Ellen; Townes, Jesse P.; Tang, Haixu

2015-01-01

A complete understanding of evolutionary processes requires that factors determining spontaneous mutation rates and spectra be identified and characterized. Using mutation accumulation followed by whole-genome sequencing, we found that the mutation rates of three widely diverged commensal Escherichia coli strains differ only by about 50%, suggesting that a rate of 1–2 × 10−3 mutations per generation per genome is common for this bacterium. Four major forces are postulated to contribute to spontaneous mutations: intrinsic DNA polymerase errors, endogenously induced DNA damage, DNA damage caused by exogenous agents, and the activities of error-prone polymerases. To determine the relative importance of these factors, we studied 11 strains, each defective for a major DNA repair pathway. The striking result was that only loss of the ability to prevent or repair oxidative DNA damage significantly impacted mutation rates or spectra. These results suggest that, with the exception of oxidative damage, endogenously induced DNA damage does not perturb the overall accuracy of DNA replication in normally growing cells and that repair pathways may exist primarily to defend against exogenously induced DNA damage. The thousands of mutations caused by oxidative damage recovered across the entire genome revealed strong local-sequence biases of these mutations. Specifically, we found that the identity of the 3′ base can affect the mutability of a purine by oxidative damage by as much as eightfold. PMID:26460006

Damage Caused by the Rogue Trustee

ERIC Educational Resources Information Center

O'Banion, Terry

2009-01-01

Fifty-nine community college presidents and chancellors in 16 states report on the damage caused by rogue trustees. While the damage to presidents, other trustees, and faculty and staff is alarming, the damage these trustees cause the college suggests that the rogue trustee may be the single most destructive force ever to plague an educational…

How distributed processing produces false negatives in voxel-based lesion-deficit analyses.

PubMed

Gajardo-Vidal, Andrea; Lorca-Puls, Diego L; Crinion, Jennifer T; White, Jitrachote; Seghier, Mohamed L; Leff, Alex P; Hope, Thomas M H; Ludersdorfer, Philipp; Green, David W; Bowman, Howard; Price, Cathy J

2018-07-01

In this study, we hypothesized that if the same deficit can be caused by damage to one or another part of a distributed neural system, then voxel-based analyses might miss critical lesion sites because preservation of each site will not be consistently associated with preserved function. The first part of our investigation used voxel-based multiple regression analyses of data from 359 right-handed stroke survivors to identify brain regions where lesion load is associated with picture naming abilities after factoring out variance related to object recognition, semantics and speech articulation so as to focus on deficits arising at the word retrieval level. A highly significant lesion-deficit relationship was identified in left temporal and frontal/premotor regions. Post-hoc analyses showed that damage to either of these sites caused the deficit of interest in less than half the affected patients (76/162 = 47%). After excluding all patients with damage to one or both of the identified regions, our second analysis revealed a new region, in the anterior part of the left putamen, which had not been previously detected because many patients had the deficit of interest after temporal or frontal damage that preserved the left putamen. The results illustrate how (i) false negative results arise when the same deficit can be caused by different lesion sites; (ii) some of the missed effects can be unveiled by adopting an iterative approach that systematically excludes patients with lesions to the areas identified in previous analyses, (iii) statistically significant voxel-based lesion-deficit mappings can be driven by a subset of patients; (iv) focal lesions to the identified regions are needed to determine whether the deficit of interest is the consequence of focal damage or much more extensive damage that includes the identified region; and, finally, (v) univariate voxel-based lesion-deficit mappings cannot, in isolation, be used to predict outcome in other patients. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Comparison of effects of calcium carbasalate and aspirin on gastroduodenal mucosal damage in human volunteers.

PubMed Central

Murray, F E; Hudson, N; Atherton, J C; Cole, A T; Scheck, F; Hawkey, C J

1996-01-01

Calcium carbasalate is a therapeutically active salicylate which seems to cause less gastroduodenal mucosal damage than aspirin in laboratory animals. This endoscopist-blinded, randomised, cross over trial aimed to compare acute gastric mucosal damage in 20 healthy volunteers treated with acetyl salicylic acid (ASA) (650 mg three times daily) and effervescent calcium carbasalate (ECC) (826.8 mg three times daily) bioequivalent to 650 mg ASA over a five day period. Endoscopy was performed immediately before treatment and on day 5 of each treatment. Serum salicylate, thromboxane B2, and gastric mucosal prostaglandin E2 (PGE2) concentrations were measured after endoscopy. ECC caused fewer gastric mucosal erosions than ASA. The total number of gastric erosions was 23.8 (16.1) in the ASA treated subjects compared with 9.1 (8.7) in ECC treated subjects (p = 0.004). Differences between ASA and ECC were significant for both the gastric antrum and body, and for both haemorrhagic and non-haemorrhagic erosions. The mean gastric body Lanza score for mucosal damage was lower after ECC than ASA (p = 0.003). The visual analogue score for gastric body damage was lower for ECC (16.9 mm (15.9)) than for ASA (32.7 mm (20.8)), p = 0.008. Serum salicylate concentrations were similar after both preparations (ASA: 66 (23) mg/l, versus ECC: 58 (17) mg/l, NS). Serum thromboxane B2 was similarly reduced using both preparations-97.2 (3.5)% inhibition with ASA, 95.2 (5.5)% inhibition with calcium carbasalate (NS). Suppression of gastric mucosal PGE2 synthesis was similar with both preparations (ASA: 83.4 (17.1)%; ECC 84.3 (12.9)%; NS). It is concluded that ECC causes significantly less gastroduodenal mucosal damage than ASA administered at bioequivalent doses as judged by serum salicylate, serum thromboxane, and mucosal PGE2 values. ECC may therefore be a less harmful alternative treatment to plain ASA. PMID:8566836

The effect of phytosterol protects rats against 4-nitrophenol-induced liver damage.

PubMed

Chen, Jiaqin; Song, Meiyan; Li, Yansen; Zhang, Yonghui; Taya, Kazuyoshi; Li, ChunMei

2016-01-01

We investigated the effect of phytosterol (PS) in regard to liver damage induced by 4-nitrophenol (PNP). Twenty rats were randomly divided into four groups (Control, PS, PNP, and PNP+PS). The PS and PNP+PS groups were pretreated with PS for one week. The PNP and PNP+PS groups were injected subcutaneously with PNP for 28 days. The control group received a basal diet and was injected with vehicle alone. Treatment with PS prevented the elevation of the total bilirubin levels, as well as an increase in serum alkaline transaminase and aspartate transaminase, which are typically caused by PNP-induced liver damage. Histopathologically showed that liver damage was significantly mitigated by PS treatment. However, there was no significant change in antioxidant enzyme activities, and the Nrf2-antioxidant system was not activated after treatment with PS. These results suggest that PS could mitigate liver damage induced by PNP, but does not enhance antioxidant capacity. Copyright © 2015 Elsevier B.V. All rights reserved.

Lemon balm extract (Melissa officinalis, L.) promotes melanogenesis and prevents UVB-induced oxidative stress and DNA damage in a skin cell model.

PubMed

Pérez-Sánchez, Almudena; Barrajón-Catalán, Enrique; Herranz-López, María; Castillo, Julián; Micol, Vicente

2016-11-01

Solar ultraviolet (UV) radiation is one of the main causes of a variety of cutaneous disorders, including photoaging and skin cancer. Its UVB component (280-315nm) leads to oxidative stress and causes inflammation, DNA damage, p53 induction and lipid and protein oxidation. Recently, an increase in the use of plant polyphenols with antioxidant and anti-inflammatory properties has emerged to protect human skin against the deleterious effects of sunlight. This study evaluates the protective effects of lemon balm extract (LBE) (Melissa Officinalis, L) and its main phenolic compound rosmarinic acid (RA) against UVB-induced damage in human keratinocytes. The LBE composition was determined by HPLC analysis coupled to photodiode array detector and ion trap mass spectrometry with electrospray ionization (HPLC-DAD-ESI-IT-MS/MS). Cell survival, ROS generation and DNA damage were determined upon UVB irradiation in the presence of LBE. The melanogenic capacity of LBE was also determined. RA and salvianolic acid derivatives were the major compounds, but caffeic acid and luteolin glucuronide were also found in LBE. LBE and RA significantly increased the survival of human keratinocytes upon UVB radiation, but LBE showed a stronger effect. LBE significantly decreased UVB-induced intracellular ROS production. Moreover, LBE reduced UV-induced DNA damage and the DNA damage response (DDR), which were measured as DNA strand breaks in the comet assay and histone H2AX activation, respectively. Finally, LBE promoted melanogenesis in the cell model. These results suggest that LBE may be considered as a candidate for the development of oral/topical photoprotective ingredients against UVB-induced skin damage. Copyright © 2016 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

Urban Flood Management with Integrated Inland-River System in Seoul

NASA Astrophysics Data System (ADS)

Moon, Y. I.; Kim, J. S.; Yuk, J. M.

2015-12-01

Global warming and climate change have caused significant damage and loss of life worldwide. The pattern of natural disasters has gradually diversified and their frequency is increasing. The impact of climate change on flood risk in urban rivers is of particular interest because these areas are typically densely populated. The occurrence of urban river flooding due to climate change not only causes significant loss of life and property but also causes health and social problems. It is therefore necessary to develop a scientific urban flood management system to cope with and reduce the impacts of climate change, including flood damage. In this study, we are going to introduce Integrated Inland-River Flood Analysis System in Seoul to conduct predictions on flash rain or short-term rainfall by using radar and satellite information and perform prompt and accurate prediction on the inland flooded areas. In addition, this urban flood management system can be used as a tool for decision making of systematic disaster prevention through real-time monitoring.

[Assessment on the yield loss risk of longan caused by cold damage in South China].

PubMed

Zhao, Jun-fang; Yu, Hui-kang

2016-02-01

Using daily climate variables gathered from 64 meteorological stations in South China from 1961 to 2012, recognized hazard indicators about disaster grades of cold damage for longan, and methods on agricultural meteorological disasters risk and simulation technology, the yield loss risks of longan caused by cold damage in South China during different developmental periods were assessed. The results showed that during the period of physiologic differentiation of flower bud, the disasters of longan affected by mild cold damage in South China were the most common, followed by severe cold damage and moderate cold damage. The hazards caused by cold damage under different grades varied. In particular, under mild cold damage, light disaster of longan was found in Fujian, followed by Guangdong and Hainan, and Guangxi was serious. Under moderate cold damage, light disaster of longan was found in Hainan, followed by Guangdong and Guangxi, and Fujian was serious. Under severe cold damage, light disaster of longan was found in Hainan, followed by Guangdong and Guangxi, Fujian was serious. During the period of morphologic differentiation of flower bud, the disasters of longan affected by mild cold damage in South China were the most common, followed by severe cold damage and moderate cold damage, while the disasters of longan under mild, moderate and severe cold damages within this period were similar. Specifically, light disasters of longan were all found in Hainan, followed by Guangdong, Guangxi and Fujian. During the period of dormancy, the disaster of longan affected by mild cold damage in South China was the most common, followed by severe cold damage and moderate cold damage. Under mild and severe cold damage, light disaster of longan was found in Fujian, followed by Guangdong and Hainan, and Guangxi was serious. However, under moderate cold damage, light disaster of longan was found in Hainan and Guangxi, followed by Guangdong, and Fujian was serious. At the same level of hazard, the largest risk indices of yield loss of longan during different developmental stages significantly differed. Under mild cold damage, serious disasters of longan were found in the period of physiologic differentiation of flower bud, followed by the period of morphologic differentiation of flower bud and the period of dormancy. However, under moderate and severe cold damage, serious disasters of longan were found in the period of physiologic differentiation of flower bud, followed by the period of dormancy and the period of morphologic differentiation of flower bud.

Respiratory infection with Francisella novicida induces rapid dystrophic cardiac calcinosis (DCC).

PubMed

Roth, Kimberly M; Oghumu, Steve; Satoskar, Anjali A; Gunn, John S; van Rooijen, Nico; Satoskar, Abhay R

2008-06-01

Francisella tularensis causes pulmonary tularemia and death in humans when left untreated. Here, using a novel aerosol infection model, we show that acute pulmonary Francisella novicida infection not only causes pneumonia and liver damage, but also induces dystrophic cardiac calcinosis (DCC) in BALB/c mice. C57BL/6 mice also develop pneumonia and hepatic damage, but fail to develop DCC. Development of DCC in BALB/c mice is associated with significant induction of RANKL but not osteopontin in their organs. Depletion of lung macrophages prior to infection markedly reduces pericarditis and calcification in BALB/c mice but does not increase their susceptibility to infection.

Geohazards on the Moon and the Importance of the International Lunar Network

NASA Technical Reports Server (NTRS)

Cohen, Barbara A.

2009-01-01

Seven of the 28 shallow seismic events recorded by the Apollo passive seismic experiment (PSE) network released energy equivalent to earthquakes with magnitudes of 5 or greater. On Earth, such quakes can cause extensive damage to structures near the epicenter. Unexpected structural damage to a lunar habitat could have devastating results and thus, lunar seismicity may present a significant geohazard to long-term human habitation.

Intense THz pulses cause H2AX phosphorylation and activate DNA damage response in human skin tissue

PubMed Central

Titova, Lyubov V.; Ayesheshim, Ayesheshim K.; Golubov, Andrey; Fogen, Dawson; Rodriguez-Juarez, Rocio; Hegmann, Frank A.; Kovalchuk, Olga

2013-01-01

Recent emergence and growing use of terahertz (THz) radiation for medical imaging and public security screening raise questions on reasonable levels of exposure and health consequences of this form of electromagnetic radiation. In particular, picosecond-duration THz pulses have shown promise for novel diagnostic imaging techniques. However, the effects of THz pulses on human cells and tissues thus far remain largely unknown. We report on the investigation of the biological effects of pulsed THz radiation on artificial human skin tissues. We observe that exposure to intense THz pulses for ten minutes leads to a significant induction of H2AX phosphorylation, indicating that THz pulse irradiation may cause DNA damage in exposed skin tissue. At the same time, we find a THz-pulse-induced increase in the levels of several proteins responsible for cell-cycle regulation and tumor suppression, suggesting that DNA damage repair mechanisms are quickly activated. Furthermore, we find that the cellular response to pulsed THz radiation is significantly different from that induced by exposure to UVA (400 nm). PMID:23577291

Intense THz pulses cause H2AX phosphorylation and activate DNA damage response in human skin tissue.

PubMed

Titova, Lyubov V; Ayesheshim, Ayesheshim K; Golubov, Andrey; Fogen, Dawson; Rodriguez-Juarez, Rocio; Hegmann, Frank A; Kovalchuk, Olga

2013-04-01

Recent emergence and growing use of terahertz (THz) radiation for medical imaging and public security screening raise questions on reasonable levels of exposure and health consequences of this form of electromagnetic radiation. In particular, picosecond-duration THz pulses have shown promise for novel diagnostic imaging techniques. However, the effects of THz pulses on human cells and tissues thus far remain largely unknown. We report on the investigation of the biological effects of pulsed THz radiation on artificial human skin tissues. We observe that exposure to intense THz pulses for ten minutes leads to a significant induction of H2AX phosphorylation, indicating that THz pulse irradiation may cause DNA damage in exposed skin tissue. At the same time, we find a THz-pulse-induced increase in the levels of several proteins responsible for cell-cycle regulation and tumor suppression, suggesting that DNA damage repair mechanisms are quickly activated. Furthermore, we find that the cellular response to pulsed THz radiation is significantly different from that induced by exposure to UVA (400 nm).

Seedling mortality in Hawaiian rain forest: The role of small-scale physical disturbance

USGS Publications Warehouse

Drake, D.R.; Pratt, L.W.

2001-01-01

Most montane rain forests on the island of Hawaii consist of a closed canopy formed by Cibotium spp. tree ferns beneath an open canopy of emergent Metrosideros polymorpha trees. We used artificial seedlings to assess the extent to which physical disturbance caused by the senescing fronds of tree ferns and the activities of feral pigs might limit tree regeneration. Artificial seedlings were established terrestrially (N = 300) or epiphytically (N = 300) on tree fern stems. Half of the seedlings on each substrate were in an exclosure lacking feral pigs and half were in forest with pigs present. After one year, the percentage of seedlings damaged was significantly greater among terrestrial seedlings (25.7%) than epiphytic seedlings (11.3%). Significantly more terrestrial seedlings were damaged in the presence of pigs (31.3%) than in the absence of pigs (20.0%). Senescing fronds of tree ferns were responsible for 60.3 percent of the damaged seedlings. Physical disturbance is potentially a major cause of seedling mortality and may reduce the expected half-life of a seedling cohort to less than two years.

Identifying Hail Signatures in Satellite Imagery from the 9-10 August 2011 Severe Weather Event

NASA Technical Reports Server (NTRS)

Dryden, Rachel L.; Molthan, Andrew L.; Cole, Tony A.; Bell, Jordan

2014-01-01

Severe thunderstorms can produce large hail that causes property damage, livestock fatalities, and crop failure. However, detailed storm surveys of hail damage conducted by the National Weather Service (NWS) are not required. Current gaps also exist between Storm Prediction Center (SPC) hail damage estimates and crop-insurance payouts. NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard the Terra and Aqua satellites can be used to support NWS damage assessments, particularly to crops during the growing season. The two-day severe weather event across western Nebraska and central Kansas during 9-10 August 2011 offers a case study for investigating hail damage signatures by examining changes in Normalized Difference Vegetation Index (NDVI) derived from MODIS imagery. By analyzing hail damage swaths in satellite imagery, potential economic losses due to crop damage can be quantified and further improve the estimation of weather impacts on agriculture without significantly increasing manpower requirements.

Summary of floods in the United States during 1960

USGS Publications Warehouse

Rostvedt, J.O.

1965-01-01

This report describes the most outstanding floods in the United States during 1960. No major floods occurred during the year, although two floods caused severe damage the first in March and April in eastern Nebraska and adjacent areas, and the second in September in Puerto Rico.Unseasonal rains in mid-March caused extensive flooding in north-central Florida. Several thousand persons were evacuated from their homes, and damage to homes, roads, and crops was extensive.The most widespread flooding ever known in Nebraska occurred late in March and early in April as a result of rapid melting of a heavy snow cover. Most of the flood damage, estimated at about $3 million, was to roads and bridges. The flood area extended into South Dakota, Iowa, Kansas, Missouri, and Wisconsin.Snowmelt in April supplemented by rains and later heavy rains in early May caused severe flooding in northern Wisconsin and in Michigan Upper Peninsula.The most destructive flood of the year was in eastern Puerto Rico as the result of hurricane Donna. More than one hundred persons died, and considerably more than one hundred persons were injured; property damage was f.bout $7 million. Hurricane Donna also caused severe flooding as it passed over Florida and along the Atlantic coastline.In addition to these floods mentioned, 31 others of lesser magnitude were significant enough to report in this annual summary.

Selective antitumor activity of roscovitine in head and neck cancer

PubMed Central

Biktasova, Asel; Bellinger, Gary; Yarbrough, Wendell G.; Issaeva, Natalia

2016-01-01

Radiation and chemotherapy that are commonly used to treat human cancers damage cellular DNA. DNA damage appears to be more toxic to cancer cells than normal cells, most likely due to deregulated checkpoint activation and/or deficiency in DNA repair pathways that are characteristics of many tumors. However, unwanted side effects arise as a result of DNA damage to normal cells during the treatment. Here, we show that roscovitine, a cyclin-dependent kinase (CDK) inhibitor that inhibits CDK-1, CDK-2, CDK-5, CDK-7, and CDK-9 due to competitive binding to the ATP site on the kinases, causes significant DNA damage followed by p53-dependent cell death in human papilloma virus (HPV)-positive, but not in HPV-negative, head and neck cancer cells. Since HPV positivity was a molecular marker for increased sensitivity of cells to roscovitine, we reasoned that systemic roscovitine administration would not be toxic to healthy HPV-negative tissue. Indeed, low roscovitine doses significantly inhibited the growth of HPV-associated xenografted tumors in mice without causing any detectable side effects. Given that inhibition of CDKs has been shown to inhibit replication of several viruses, we suggest that roscovitine treatment may represent a selective and safe targeted therapeutic option against HPV-positive head and neck cancer. PMID:27233076

Inhibition of Ultraviolet B-Induced Expression of the Proinflammatory Cytokines TNF-α and VEGF in the Cornea by Fucoxanthin Treatment in a Rat Model.

PubMed

Chen, Shiu-Jau; Lee, Ching-Ju; Lin, Tzer-Bin; Liu, Hsiang-Jui; Huang, Shuan-Yu; Chen, Jia-Zeng; Tseng, Kuang-Wen

2016-01-07

Ultraviolet B (UVB) irradiation is the most common cause of radiation damage to the eyeball and is a risk factor for human corneal damage. We determined the protective effect of fucoxanthin, which is a carotenoid found in common edible seaweed, on ocular tissues against oxidative UVB-induced corneal injury. The experimental rats were intravenously injected with fucoxanthin at doses of 0.5, 5 mg/kg body weight/day or with a vehicle before UVB irradiation. Lissamine green for corneal surface staining showed that UVB irradiation caused serious damage on the corneal surface, including severe epithelial exfoliation and deteriorated epithelial smoothness. Histopathological lesion examination revealed that levels of proinflammatory cytokines, including tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF), significantly increased. However, pretreatment with fucoxanthin inhibited UVB radiation-induced corneal disorders including evident preservation of corneal surface smoothness, downregulation of proinflammatory cytokine expression, and decrease of infiltrated polymorphonuclear leukocytes from UVB-induced damage. Moreover, significant preservation of the epithelial integrity and inhibition of stromal swelling were also observed after UVB irradiation in fucoxanthin-treated groups. Pretreatment with fucoxanthin may protect against UVB radiation-induced corneal disorders by inhibiting expression of proinflammatory factors, TNF-α, and VEGF and by blocking polymorphonuclear leukocyte infiltration.

Evaluation of the genotoxic activity of dicamba and atrazine herbicides in several Mexican and South American varieties of sweetcorn (Zea mays L.).

PubMed

Reynoso, M S; Alvarez, C M; De la Cruz, L; Escoto, M D; Sánchez, J J G

2015-12-11

Corn is a major crop and various herbicides are used to maximize its production, which include a dicamba-atrazine mixture. This has great advantages, but can also induce DNA damage. Genotoxic activity was assessed by comet assay following application of two concentrations of dicamba-atrazine: 1000-2000 and 2000-4000 ppm. Apical meristem leaf nuclei from 119 varieties of sweetcorn plants from Mexico and South America, and from five commercial sweetcorn hybrids were used. Each accession comprised two individuals per concentration and two controls. Significant genotoxic activity (P < 0.001) was observed following treatment with 1000-2000 and 2000-4000 ppm compared to the negative control. There was no difference in the genotoxic activity induced by both 1000-2000 and 2000-4000 ppm concentrations in plants from Mexico and South America (P > 0.05) except (P < 0.05) in the 2000-4000 ppm treated plants from Mexico and the 1000-2000 ppm treated plants from South America. Sweetcorn hybrids showed significant genetic damage (P < 0.01) at all concentrations compared to the negative controls. Thus, the dicamba-atrazine mixture caused genetic damage to corn plants, and it suggested that Mexican sweetcorn is more sensitive to dicamba-atrazine than the maize varieties from South America. Neither hybrid status nor the origin avoids DNA damage caused by Marvel. Thus, maize can be useful as a biomonitor of genetic damage induced by chemicals and to identify possible phenotypes based upon the amount of genetic damage induced by herbicides and selection of resistant genotypes.

ESTUARINE HABITAT RESTORATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thom, Ronald M.; Borde, Amy B.

2015-09-01

Restoring estuarine habitats generally means repairing damages caused by humans and natural forces. Because of the extensive human occupation, development, and use of coastal areas for centuries, the extensive estuarine habitats have been either destroyed or significantly impaired.

78 FR 29089 - Safety Zones; Hawaiian Island Commercial Harbors, HI

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-17

..., cause millions of dollars in property damage, and alter sensitive ecologies. The tsunami generated by... individually or cumulatively have a significant effect on the human environment. This rule will evacuate...

Surface water floods in Switzerland: what insurance claim records tell us about the damage in space and time

NASA Astrophysics Data System (ADS)

Bernet, Daniel B.; Prasuhn, Volker; Weingartner, Rolf

2017-09-01

Surface water floods (SWFs) have received increasing attention in the recent years. Nevertheless, we still know relatively little about where, when and why such floods occur and cause damage, largely due to a lack of data but to some degree also because of terminological ambiguities. Therefore, in a preparatory step, we summarize related terms and identify the need for unequivocal terminology across disciplines and international boundaries in order to bring the science together. Thereafter, we introduce a large (n = 63 117), long (10-33 years) and representative (48 % of all Swiss buildings covered) data set of spatially explicit Swiss insurance flood claims. Based on registered flood damage to buildings, the main aims of this study are twofold: First, we introduce a method to differentiate damage caused by SWFs and fluvial floods based on the geographical location of each damaged object in relation to flood hazard maps and the hydrological network. Second, we analyze the data with respect to their spatial and temporal distributions aimed at quantitatively answering the fundamental questions of how relevant SWF damage really is, as well as where and when it occurs in space and time. This study reveals that SWFs are responsible for at least 45 % of the flood damage to buildings and 23 % of the associated direct tangible losses, whereas lower losses per claim are responsible for the lower loss share. The Swiss lowlands are affected more heavily by SWFs than the alpine regions. At the same time, the results show that the damage claims and associated losses are not evenly distributed within each region either. Damage caused by SWFs occurs by far most frequently in summer in almost all regions. The normalized SWF damage of all regions shows no significant upward trend between 1993 and 2013. We conclude that SWFs are in fact a highly relevant process in Switzerland that should receive similar attention like fluvial flood hazards. Moreover, as SWF damage almost always coincides with fluvial flood damage, we suggest considering SWFs, like fluvial floods, as integrated processes of our catchments.

3,4-Methylenedioxymethamphetamine (MDMA) abuse may cause oxidative stress and potential free radical damage.

PubMed

Zhou, Jun F; Chen, Peng; Zhou, Ye H; Zhang, Liang; Chen, Huai H

2003-05-01

To investigate whether 3,4-methylenedioxymethamphetamine abuse (MDMA abuse) may cause oxidative stress and potential free radical damage in the bodies of MDMA abusers (MA), and to explore the mechanisms by which MDMA abuse may be causing oxidative stress. One hundred and twenty MA and 120 healthy volunteers (HV) were enrolled in a random control study design, in which the level of lipoperoxide (LPO) in erythrocytes, and the levels of Vitamin C (VC), Vitamin E (VE) and beta-carotene (beta-CAR) in plasma as well as the activities of superoxide dismutase (SOD) and catalase (CAT) in erythrocytes were determined by spectrophotometric methods. Compared with the average values of the above biochemical parameters in the HV group, the average value of LPO in erythrocytes in the MA group was significantly increased (P < 0.0001), while the average values of VC, VE and beta-CAR in plasma as well as those of SOD and CAT in erythrocytes in the MA group were significantly decreased (P < 0.0001). The analysis of bivariate correlations suggested that with the increase of the MDMA abuse dose and the MDMA abuse duration, the level of LPO in erythrocytes in the MA was increased (P < 0.0001), while the levels of VC, VE and beta-CAR in plasma as well as the activities of SOD and CAT in erythrocytes in the MA were decreased (P < 0.0001). The findings in this study suggest that MDMA abuse may cause oxidative stress and potential free radical damage to MA.

Population structure and the rapid increase of QoI fungicide resistance in frogeye leaf spot (Cercospora sojina) from Tennessee

USDA-ARS?s Scientific Manuscript database

Frogeye leaf spot (FLS), caused by Cercospora sojina, causes significant damage to soybean in the US. In this study, C. sojina isolates collected from Jackson and Milan, TN in 2015 and historical isolates collected before 2015 were included. Fifty novel single nucleotide polymorphism (SNP) markers, ...

Effects of forcing uncertainties in the improvement skills of assimilating satellite soil moisture retrievals into flood forecasting models

USDA-ARS?s Scientific Manuscript database

Floods have negative impacts on society, causing damages in infrastructures and industry, and in the worst cases, causing loss of human lives. Thus early and accurate warning is crucial to significantly reduce the impacts on public safety and economy. Reliable flood warning can be generated using ...

Trash to Treasure: Using Recyclables in Physical Activity Settings

ERIC Educational Resources Information Center

Chen, YuChun

2016-01-01

Americans produce approximately 250 million tons of trash every year, and almost 35 percent of those are of recyclable materials. There are over 1,200 landfills in the United States, and many have caused and will potentially cause significant damage to the environment. It is important for the next generation to know that what is perceived as…

Antifungal defense of probiotic Lactobacillus rhamnosus GG is mediated by blocking adhesion and nutrient depletion.

PubMed

Mailänder-Sánchez, Daniela; Braunsdorf, Christina; Grumaz, Christian; Müller, Christoph; Lorenz, Stefan; Stevens, Philip; Wagener, Jeanette; Hebecker, Betty; Hube, Bernhard; Bracher, Franz; Sohn, Kai; Schaller, Martin

2017-01-01

Candida albicans is an inhabitant of mucosal surfaces in healthy individuals but also the most common cause of fungal nosocomial blood stream infections, associated with high morbidity and mortality. As such life-threatening infections often disseminate from superficial mucosal infections we aimed to study the use of probiotic Lactobacillus rhamnosus GG (LGG) in prevention of mucosal C. albicans infections. Here, we demonstrate that LGG protects oral epithelial tissue from damage caused by C. albicans in our in vitro model of oral candidiasis. Furthermore, we provide insights into the mechanisms behind this protection and dissect direct and indirect effects of LGG on C. albicans pathogenicity. C. albicans viability was not affected by LGG. Instead, transcriptional profiling using RNA-Seq indicated dramatic metabolic reprogramming of C. albicans. Additionally, LGG had a significant impact on major virulence attributes, including adhesion, invasion, and hyphal extension, whose reduction, consequently, prevented epithelial damage. This was accompanied by glucose depletion and repression of ergosterol synthesis, caused by LGG, but also due to blocked adhesion sites. Therefore, LGG protects oral epithelia against C. albicans infection by preventing fungal adhesion, invasion and damage, driven, at least in parts, by metabolic reprogramming due to nutrient limitation caused by LGG.

N-Methyl-d-Aspartate (NMDA) Receptor Blockade Prevents Neuronal Death Induced by Zika Virus Infection.

PubMed

Costa, Vivian V; Del Sarto, Juliana L; Rocha, Rebeca F; Silva, Flavia R; Doria, Juliana G; Olmo, Isabella G; Marques, Rafael E; Queiroz-Junior, Celso M; Foureaux, Giselle; Araújo, Julia Maria S; Cramer, Allysson; Real, Ana Luíza C V; Ribeiro, Lucas S; Sardi, Silvia I; Ferreira, Anderson J; Machado, Fabiana S; de Oliveira, Antônio C; Teixeira, Antônio L; Nakaya, Helder I; Souza, Danielle G; Ribeiro, Fabiola M; Teixeira, Mauro M

2017-04-25

Zika virus (ZIKV) infection is a global health emergency that causes significant neurodegeneration. Neurodegenerative processes may be exacerbated by N -methyl-d-aspartate receptor (NMDAR)-dependent neuronal excitoxicity. Here, we have exploited the hypothesis that ZIKV-induced neurodegeneration can be rescued by blocking NMDA overstimulation with memantine. Our results show that ZIKV actively replicates in primary neurons and that virus replication is directly associated with massive neuronal cell death. Interestingly, treatment with memantine or other NMDAR blockers, including dizocilpine (MK-801), agmatine sulfate, or ifenprodil, prevents neuronal death without interfering with the ability of ZIKV to replicate in these cells. Moreover, in vivo experiments demonstrate that therapeutic memantine treatment prevents the increase of intraocular pressure (IOP) induced by infection and massively reduces neurodegeneration and microgliosis in the brain of infected mice. Our results indicate that the blockade of NMDARs by memantine provides potent neuroprotective effects against ZIKV-induced neuronal damage, suggesting it could be a viable treatment for patients at risk for ZIKV infection-induced neurodegeneration. IMPORTANCE Zika virus (ZIKV) infection is a global health emergency associated with serious neurological complications, including microcephaly and Guillain-Barré syndrome. Infection of experimental animals with ZIKV causes significant neuronal damage and microgliosis. Treatment with drugs that block NMDARs prevented neuronal damage both in vitro and in vivo These results suggest that overactivation of NMDARs contributes significantly to the neuronal damage induced by ZIKV infection, and this is amenable to inhibition by drug treatment. Copyright © 2017 Costa et al.

Mitigating the Impact of Bats in Historic Churches: The Response of Natterer’s Bats Myotis nattereri to Artificial Roosts and Deterrence

PubMed Central

Zeale, Matt R. K.; Bennitt, Emily; Newson, Stuart E.; Packman, Charlotte; Browne, William J.; Harris, Stephen; Jones, Gareth; Stone, Emma

2016-01-01

Bats frequently roost in historic churches, and these colonies are of considerable conservation value. Inside churches, bat droppings and urine can cause damage to the historic fabric of the building and to items of cultural significance. In extreme cases, large quantities of droppings can restrict the use of a church for worship and/or other community functions. In the United Kingdom, bats and their roosts are protected by law, and striking a balance between conserving the natural and cultural heritage can be a significant challenge. We investigated mitigation strategies that could be employed in churches and other historic buildings to alleviate problems caused by bats without adversely affecting their welfare or conservation status. We used a combination of artificial roost provision and deterrence at churches in Norfolk, England, where significant maternity colonies of Natterer’s bats Myotis nattereri damage church features. Radio-tracking data and population modelling showed that excluding M. nattereri from churches is likely to have a negative impact on their welfare and conservation status, but that judicious use of deterrents, especially high intensity ultrasound, can mitigate problems caused by bats. We show that deterrence can be used to move bats humanely from specific roosting sites within a church and limit the spread of droppings and urine so that problems to congregations and damage to cultural heritage can be much reduced. In addition, construction of bespoke roost spaces within churches can allow bats to continue to roost within the fabric of the building without flying in the church interior. We highlight that deterrence has the potential to cause serious harm to M. nattereri populations if not used judiciously, and so the effects of deterrents will need careful monitoring, and their use needs strict regulation. PMID:26771548

Photoinhibition-like damage to the photosynthetic apparatus in plant leaves induced by submergence treatment in the dark.

PubMed

Fan, Xingli; Zhang, Zishan; Gao, Huiyuan; Yang, Cheng; Liu, Meijun; Li, Yuting; Li, Pengmin

2014-01-01

Submergence is a common type of environmental stress for plants. It hampers survival and decreases crop yield, mainly by inhibiting plant photosynthesis. The inhibition of photosynthesis and photochemical efficiency by submergence is primarily due to leaf senescence and excess excitation energy, caused by signals from hypoxic roots and inhibition of gas exchange, respectively. However, the influence of mere leaf-submergence on the photosynthetic apparatus is currently unknown. Therefore, we studied the photosynthetic apparatus in detached leaves from four plant species under dark-submergence treatment (DST), without influence from roots and light. Results showed that the donor and acceptor sides, the reaction center of photosystem II (PSII) and photosystem I (PSI) in leaves were significantly damaged after 36 h of DST. This is a photoinhibition-like phenomenon similar to the photoinhibition induced by high light, as further indicated by the degradation of PsaA and D1, the core proteins of PSI and PSII. In contrast to previous research, the chlorophyll content remained unchanged and the H2O2 concentration did not increase in the leaves, implying that the damage to the photosynthetic apparatus was not caused by senescence or over-accumulation of reactive oxygen species (ROS). DST-induced damage to the photosynthetic apparatus was aggravated by increasing treatment temperature. This type of damage also occurred in the anaerobic environment (N2) without water, and could be eliminated or restored by supplying air to the water during or after DST. Our results demonstrate that DST-induced damage was caused by the hypoxic environment. The mechanism by which DST induces the photoinhibition-like damage is discussed below.

Photoinhibition-Like Damage to the Photosynthetic Apparatus in Plant Leaves Induced by Submergence Treatment in the Dark

PubMed Central

Gao, Huiyuan; Yang, Cheng; Liu, Meijun; Li, Yuting; Li, Pengmin

2014-01-01

Submergence is a common type of environmental stress for plants. It hampers survival and decreases crop yield, mainly by inhibiting plant photosynthesis. The inhibition of photosynthesis and photochemical efficiency by submergence is primarily due to leaf senescence and excess excitation energy, caused by signals from hypoxic roots and inhibition of gas exchange, respectively. However, the influence of mere leaf-submergence on the photosynthetic apparatus is currently unknown. Therefore, we studied the photosynthetic apparatus in detached leaves from four plant species under dark-submergence treatment (DST), without influence from roots and light. Results showed that the donor and acceptor sides, the reaction center of photosystem II (PSII) and photosystem I (PSI) in leaves were significantly damaged after 36 h of DST. This is a photoinhibition-like phenomenon similar to the photoinhibition induced by high light, as further indicated by the degradation of PsaA and D1, the core proteins of PSI and PSII. In contrast to previous research, the chlorophyll content remained unchanged and the H2O2 concentration did not increase in the leaves, implying that the damage to the photosynthetic apparatus was not caused by senescence or over-accumulation of reactive oxygen species (ROS). DST-induced damage to the photosynthetic apparatus was aggravated by increasing treatment temperature. This type of damage also occurred in the anaerobic environment (N2) without water, and could be eliminated or restored by supplying air to the water during or after DST. Our results demonstrate that DST-induced damage was caused by the hypoxic environment. The mechanism by which DST induces the photoinhibition-like damage is discussed below. PMID:24586508

Protective effect of curcumin (Curcuma longa), against aluminium toxicity: Possible behavioral and biochemical alterations in rats.

PubMed

Kumar, Anil; Dogra, Samrita; Prakash, Atish

2009-12-28

Aluminium is a potent neurotoxin and has been associated with Alzheimer's disease (AD) causality for decades. Prolonged aluminium exposure induces oxidative stress and increases amyloid beta levels in vivo. Current treatment modalities for AD provide only symptomatic relief thus necessitating the development of new drugs with fewer side effects. The aim of the study was to demonstrate the protective effect of chronic curcumin administration against aluminium-induced cognitive dysfunction and oxidative damage in rats. Aluminium chloride (100 mg/kg, p.o.) was administered to rats daily for 6 weeks. Rats were concomitantly treated with curcumin (per se; 30 and 60 mg/kg, p.o.) daily for a period of 6 weeks. On the 21st and 42nd day of the study behavioral studies to evaluate memory (Morris water maze and elevated plus maze task paradigms) and locomotion (photoactometer) were done. The rats were sacrificed on 43rd day following the last behavioral test and various biochemical tests were performed to assess the extent of oxidative damage. Chronic aluminium chloride administration resulted in poor retention of memory in Morris water maze, elevated plus maze task paradigms and caused marked oxidative damage. It also caused a significant increase in the acetylcholinesterase activity and aluminium concentration in aluminium treated rats. Chronic administration of curcumin significantly improved memory retention in both tasks, attenuated oxidative damage, acetylcholinesterase activity and aluminium concentration in aluminium treated rats (P<0.05). Curcumin has neuroprotective effects against aluminium-induced cognitive dysfunction and oxidative damage.

Prophylaxis with Bacopa monnieri attenuates acrylamide induced neurotoxicity and oxidative damage via elevated antioxidant function.

PubMed

Shinomol, George Kunnel; Raghunath, Narayanareddy; Bharath, Muchukunte Mukunda Srinivas; Muralidhara

2013-03-01

Acrylamide (ACR) is a water-soluble, vinyl monomer that has multiple chemical and industrial applications. Exposure to ACR causes neuropathy and associated neurological defects including gait abnormalities and skeletal muscle weakness, due to impaired neurotransmitter release and eventual neurodegeneration. Using in vivo and in vitro models, we examined whether oxidative events are involved in ACR-mediated neurotoxicity and whether these could be prevented by natural plant extracts. Administration (i.p.) of ACR in mice (40 mg/kg bw/ d for 5d) induced significant oxidative damage in the brain cortex and liver as evidenced by elevated lipid peroxidation, reactive oxygen species and protein carbonyls. This was associated with lowered antioxidant activities including antioxidant enzymes (catalase, glutathione-s-transferase) and reduced glutathione (GSH) compared to untreated controls. Similarly, exposure of N27 neuronal cells in culture to ACR (1-5 mM) caused dose-dependent neuronal death and lowered GSH. Interestingly, dietary supplementation with the leaf powder of Bacopa monnieri (BM) (which possesses neuroprotective properties and nootropic activity) in mice for 30 days offered significant protection against ACR toxicity and oxidative damage in vivo. Similarly, pretreatment with BM protected the N27 cells against ACR-induced cell death and associated oxidative damage. Co-treatment and pre-treatment of Drosophila melanogaster with BM extract protected against ACR-induced locomotor dysfunction and GSH depletion. We infer that BM displays prophylactic effects against ACR induced oxidative damage and neurotoxicity with potential therapeutic application in human pathology associated with neuropathy.

Possible role of zinc in diminishing lead-related occupational stress-a zinc nutrition concern.

PubMed

Wani, Ab Latif; Ahmad, Ajaz; Shadab, G G H A; Usmani, Jawed Ahmad

2017-03-01

Lead and zinc are mostly present at the same occupational source and usually found as co-contaminants. Lead is known to associate with detrimental effects to humans. Zinc however is an essential nutrient and its deficiency causes debilitating effects on growth and development. Besides, it acts as core ion of important enzymes and proteins. The purpose of this study was to examine if zinc concentrations are associated with blood lead levels and if zinc may prevent lead-induced DNA damage. Blood samples were collected from 92 workers as participants occupationally exposed to lead or lead and zinc and 38 comparison participants having no history of such exposure. Lead and zinc levels were determined from blood by atomic absorption spectrophotometry and genetic damage was assessed by comet assay. Correlation was calculated by Spearman's rho. Lead concentrations were observed to increase among workers with increase in years of exposure. There was a significant difference (p < 0.001) in blood lead levels between workers and controls. In addition, significant difference (p < 0.001) in the genetic damage was observed among workers and controls. A clear effect of increased occupational exposure was visible among workers. Multiple regression analysis further reveals the positive effect of lead, while as the inverse effect of zinc on DNA damage. The results suggest that zinc may influence body lead absorption and may have a role in preventing the genetic damage caused by lead.

Fatigue damage in cross-ply titanium metal matrix composites containing center holes

NASA Technical Reports Server (NTRS)

Bakuckas, J. G., Jr.; Johnson, W. S.; Bigelow, C. A.

1992-01-01

The development of fatigue damage in (0/90) sub SCS-6/TI-15-3 laminates containing center holes was studied. Stress levels required for crack initiation in the matrix were predicted using an effective strain parameter and compared to experimental results. Damage progression was monitored at various stages of fatigue loading. In general, a saturated state of damage consisting of matrix cracks and fiber matrix debonding was obtained which reduced the composite modulus. Matrix cracks were bridged by the 0 deg fibers. The fatigue limit (stress causing catastrophic fracture of the laminates) was also determined. The static and post fatigue residual strengths were accurately predicted using a three dimensional elastic-plastic finite element analysis. The matrix damage that occurred during fatigue loading significantly reduced the notched strength.

Foam-on-Tile Damage Model

NASA Technical Reports Server (NTRS)

Koharchik, Michael; Murphy, Lindsay; Parker, Paul

2012-01-01

An impact model was developed to predict how three specific foam types would damage the Space Shuttle Orbiter insulating tiles. The inputs needed for the model are the foam type, the foam mass, the foam impact velocity, the foam impact incident angle, the type being impacted, and whether the tile is new or aged (has flown at least one mission). The model will determine if the foam impact will cause damage to the tile. If it can cause damage, the model will output the damage cavity dimensions (length, depth, entry angle, exit angle, and sidewall angles). It makes the calculations as soon as the inputs are entered (less than 1 second). The model allows for the rapid calculation of numerous scenarios in a short time. The model was developed from engineering principles coupled with significant impact testing (over 800 foam impact tests). This model is applicable to masses ranging from 0.0002 up to 0.4 pound (0.09 up to 181 g). A prior tool performed a similar function, but was limited to the assessment of a small range of masses and did not have the large test database for verification. In addition, the prior model did not provide outputs of the cavity damage length, entry angle, exit angle, or sidewall angles.

Invasive Species in the Great Lakes

EPA Pesticide Factsheets

Invasive species have significantly changed the Great Lakes ecosystem. An invasive species is a plant or animal that is not native to an ecosystem, and whose introduction is likely to cause economic, human health, or environmental damage.

Functional and histological bladder damage in mice after photodynamic therapy: the influence of sensitiser dose and time of administration.

PubMed Central

Stewart, F. A.; Oussoren, Y.

1993-01-01

The bladders of anaesthetised mice were illuminated with red laser light (630 nm) at intervals of 1 day to 4 weeks after i.p. administration of Photofrin. Light was delivered intravesically by inserting a fibre optic, with a diffusing bulb tip, into the centre of fluid filled bladders. A single light dose of 11.3 J cm-2 applies 1 day after 10 mg kg-1 Photofrin caused a severe acute response, with increased urination frequency (five to seven times control) and hematuria. Recovery was good, however, and by 10 weeks only a mild (approximately two-fold) increase in frequency remained. There was no reduction in the amount of acute bladder damage or in the rate of healing when the interval between Photofrin and light was increased from 1 to 7 days but a 2 to 3 week interval lead to a significant reduction in damage. For an interval of 4 weeks there was only a mild (less than two-fold) increase in urination frequency during the first week. A drug dose of 2.5 mg kg-1 given 1 day before illumination caused transient haematuria but no increase in urination frequency. Doses of 5, 7.5 or 10 mg kg-1 all caused photosensitisation and the amount of bladder damage was drug dose dependent. The bladder seems to be well able to recover from severe acute damage induced by PDT. Occasional incidences of pyelonephritis were seen, however, suggesting that urinary tract infection during the acute period may lead to permanent renal damage. Images Figure 5 PMID:8398691

Repeated administrations of carbon nanotubes in male mice cause reversible testis damage without affecting fertility.

PubMed

Bai, Yuhong; Zhang, Yi; Zhang, Jingping; Mu, Qingxin; Zhang, Weidong; Butch, Elizabeth R; Snyder, Scott E; Yan, Bing

2010-09-01

Soluble carbon nanotubes show promise as materials for in vivo delivery and imaging applications. Several reports have described the in vivo toxicity of carbon nanotubes, but their effects on male reproduction have not been examined. Here, we show that repeated intravenous injections of water-soluble multiwalled carbon nanotubes into male mice can cause reversible testis damage without affecting fertility. Nanotubes accumulated in the testes, generated oxidative stress and decreased the thickness of the seminiferous epithelium in the testis at day 15, but the damage was repaired at 60 and 90 days. The quantity, quality and integrity of the sperm and the levels of three major sex hormones were not significantly affected throughout the 90-day period. The fertility of treated male mice was unaffected; the pregnancy rate and delivery success of female mice that mated with the treated male mice did not differ from those that mated with untreated male mice.

Repeated administrations of carbon nanotubes in male mice cause reversible testis damage without affecting fertility

NASA Astrophysics Data System (ADS)

Bai, Yuhong; Zhang, Yi; Zhang, Jingping; Mu, Qingxin; Zhang, Weidong; Butch, Elizabeth R.; Snyder, Scott E.; Yan, Bing

2010-09-01

Soluble carbon nanotubes show promise as materials for in vivo delivery and imaging applications. Several reports have described the in vivo toxicity of carbon nanotubes, but their effects on male reproduction have not been examined. Here, we show that repeated intravenous injections of water-soluble multiwalled carbon nanotubes into male mice can cause reversible testis damage without affecting fertility. Nanotubes accumulated in the testes, generated oxidative stress and decreased the thickness of the seminiferous epithelium in the testis at day 15, but the damage was repaired at 60 and 90 days. The quantity, quality and integrity of the sperm and the levels of three major sex hormones were not significantly affected throughout the 90-day period. The fertility of treated male mice was unaffected; the pregnancy rate and delivery success of female mice that mated with the treated male mice did not differ from those that mated with untreated male mice.

Statistical analysis of low-rise building damage caused by the San Fernando earthquake

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scholl, R.E.

1974-02-01

An empirical investigation of damage to low-rise buildings in two selected control areas within Glendale, California, caused by the ground motion precipitated by the San Fernando earthquake of February 9, 1971 is summarized. The procedures for obtaining the appropriate data and the methodology used in deriving ground motion-damage relationships are described. Motion-damage relationships are derived for overall damage and for the most frequently damaged building components. Overall motion-damage relationships are expressed in terms of damage incidence (damage ratio) and damage cost (damage cost factor). The motion-damage relationships derived from the earthquake data are compared with similar data obtained for lou-risemore » buildings subjected to ground motion generated by an underground nuclear explosion. Overall comparison results show that for the same spectral acceleration, the earthquake caused slightly more damage. Differences in ground-motion characteristics for the two types of disturbances provide the most probable explanation for this discrepancy. (auth)« less

In field damage of high and low cyanogenic cassava due to a generalist insect herbivore Cyrtomenus bergi (Hemiptera: Cydnidae).

PubMed

Riis, Lisbeth; Bellotti, Anthony Charles; Castaño, Oscar

2003-12-01

The hypothesis that cyanogenic potential in cassava roots deters polyphagous insects in the field is relevant to current efforts to reduce or eliminate the cyanogenic potential in cassava. To test this hypothesis, experiments were conducted in the field under natural selection pressure of the polyphagous root feeder Cyrtomenus bergi Froeschner (Hemiptera: Cydnidae). A number of cassava varieties (33) as well as 13 cassava siblings and their parental clone, each representing a determined level of cyanogenic potential (CNP), were scored for damage caused by C. bergi and related to CNP and nonglycosidic cyanogens, measured as hydrogen cyanide. Additionally, 161 low-CNP varieties (< 50 ppm hydrogen cyanide, fresh weight) from the cassava germplasm core collection at Centro Internacional de Agricultura Tropical (CIAT) were screened for resistance/tolerance to C. bergi. Low root damage scores were registered at all levels of CNP. Nevertheless, CNP and yield (or root size) partly explained the damage in cassava siblings (r2 = 0.82) and different cassava varieties (r2 = 0.42), but only when mean values of damage scores were used. This relation was only significant in one of two crop cycles. A logistic model describes the underlying negative relation between CNP and damage. An exponential model describes the underlying negative relation between root size and damage. Damage, caused by C. bergi feeding, released nonglycosidic cyanogens, and an exponential model fits the underlying positive relation. Fifteen low-CNP clones were selected for potential resistance/tolerance against C. bergi.

Protective Effect of Baccharis trimera Extract on Acute Hepatic Injury in a Model of Inflammation Induced by Acetaminophen

PubMed Central

Pádua, Bruno da Cruz; Rossoni Júnior, Joamyr Victor; de Brito Magalhães, Cíntia Lopes; Chaves, Míriam Martins; Silva, Marcelo Eustáquio; Pedrosa, Maria Lucia; de Souza, Gustavo Henrique Bianco; Brandão, Geraldo Célio; Rodrigues, Ivanildes Vasconcelos; Lima, Wanderson Geraldo; Costa, Daniela Caldeira

2014-01-01

Background. Acetaminophen (APAP) is a commonly used analgesic and antipyretic. When administered in high doses, APAP is a clinical problem in the US and Europe, often resulting in severe liver injury and potentially acute liver failure. Studies have demonstrated that antioxidants and anti-inflammatory agents effectively protect against the acute hepatotoxicity induced by APAP overdose. Methods. The present study attempted to investigate the protective effect of B. trimera against APAP-induced hepatic damage in rats. The liver-function markers ALT and AST, biomarkers of oxidative stress, antioxidant parameters, and histopathological changes were examined. Results. The pretreatment with B. trimera attenuated serum activities of ALT and AST that were enhanced by administration of APAP. Furthermore, pretreatment with the extract decreases the activity of the enzyme SOD and increases the activity of catalase and the concentration of total glutathione. Histopathological analysis confirmed the alleviation of liver damage and reduced lesions caused by APAP. Conclusions. The hepatoprotective action of B. trimera extract may rely on its effect on reducing the oxidative stress caused by APAP-induced hepatic damage in a rat model. General Significance. These results make the extract of B. trimera a potential candidate drug capable of protecting the liver against damage caused by APAP overdose. PMID:25435714

Hypoxia induced DNA damage in children with isolated septal defect and septal defect with great vessel anomaly of heart.

PubMed

G, Vidya; H Y, Suma; Bhat B, Vishnu; Chand, Parkash; Rao K, Ramachandra

2014-04-01

In Congenital Heart Disease (CHD), shunting of blood occurs through the anatomical defects which lead to mixing of oxygenated and deoxygenated blood. Chronic hypoxia which occurs due to the above said mechanism has the potency to cause DNA damage in children with CHD. In chronic hypoxia, there is a liberation of Reactive Oxygen Species (ROS) due to tissue injury as a result of ischemia and induction of hypoxia inducible factor - 1HIF-1 and p53 which in turn activates pro-apoptotic factors leading to alteration in the regulation of pro-apoptotic gene Blc-2 to be involved in causing the DNA damage. The extent of chronic hypoxia and the DNA damage depends on the nature of the anatomical heart defect. Hence, the present case-control study was conducted to find out the DNA damage in children with isolated septal defect and septal defect with great vessel anomaly of heart and to compare the same. The study group was categorized into those with isolated septal defects and septal defects associated with great vessel anomaly based on echo-cardiogram. Age and sex matched healthy children were taken as controls. Single-cell gel electrophoresis - Comet Assay of Alkaline Version was performed conventionally and the comets were analyzed using comet score software. The comet metrics was found to be statistically significant in children with isolated septal defect and septal defect with great vessel anomaly when compared with that of the controls. In addition, comet metrics also showed significantly increased DNA damage among children with septal defects associated with great vessel anomaly when compared to isolated septal defects. The data strongly suggests a linear correlation of severity of the anomaly involved with the degree of DNA damage as evidenced by lesser extent of DNA damage in isolated septal defect and greater in septal defect with great vessel anomaly.

Epitaxial graphene growth on FIB patterned 3C-SiC nanostructures on Si (111): reducing milling damage.

PubMed

Amjadipour, Mojtaba; MacLeod, Jennifer; Lipton-Duffin, Josh; Iacopi, Francesca; Motta, Nunzio

2017-08-25

Epitaxial growth of graphene on SiC is a scalable procedure that does not require any further transfer step, making this an ideal platform for graphene nanostructure fabrication. Focused ion beam (FIB) is a very promising tool for exploring the reduction of the lateral dimension of graphene on SiC to the nanometre scale. However, exposure of graphene to the Ga + beam causes significant surface damage through amorphisation and contamination, preventing epitaxial graphene growth. In this paper we demonstrate that combining a protective silicon layer with FIB patterning implemented prior to graphene growth can significantly reduce the damage associated with FIB milling. Using this approach, we successfully achieved graphene growth over 3C-SiC/Si FIB patterned nanostructures.

Processes involved in assisted reproduction technologies significantly increase sperm DNA fragmentation and phosphatidylserine translocation.

PubMed

Balasuriya, A; Serhal, P; Doshi, A; Harper, J C

2014-03-01

Sperm preparation techniques in assisted reproduction technologies (ART) are potential generators of exogenous stresses that cause additional DNA damage. DNA fragmentation tests, such as the sperm chromatin structure assay, involve freezing sperm samples in the absence of cryoprotectant. Thermal, oxidative stress (OS) and freezing are detrimental to sperm DNA fragmentation and phosphatidylserine (PS) translocation. The primary aim of this study was to subject mature sperm to environmental insults that normally occur during ART. We tested the hypotheses that OS, thermal stress and freeze-thawing caused sperm nuclear and membrane damage and that a positive correlation exists between PS translocation and DNA fragmentation. Sperm DNA integrity deteriorates in semen samples from men with advancing age and a sperm concentration of <15 m ml(-1) . The significant increase in sperm DNA fragmentation at 37 °C after merely 1 h is important clinically as semen liquefaction and short-term sperm storage in an ART cycle involve incubating samples at this temperature. Freezing without a cryoprotectant significantly increases the level of sperm nuclear damage, so it is important not to freeze neat semen prior to DNA fragmentation testing. This study highlights the importance of minimising the production of exogenous stresses during sperm preparation in ART. © 2012 Blackwell Verlag GmbH.

Histopomorphic Evaluation of Radiofrequency Mediated Débridement Chondroplasty

PubMed Central

Ganguly, Kumkum; McRury, Ian D; Goodwin, Peter M; Morgan, Roy E; Augé II, Wayne K

2010-01-01

The use of radiofrequency devices has become widespread for surgical ablation procedures. When ablation devices have been deployed in treatment settings requiring tissue preservation like débridement chondroplasty, adoption has been limited due to the collateral damage caused by these devices in healthy tissue surrounding the treatment site. Ex vivo radiofrequency mediated débridement chondroplasty was performed on osteochondral specimens demonstrating surface fibrillation obtained from patients undergoing knee total joint replacement. Three radiofrequency systems designed to perform débridement chondroplasty were tested each demonstrating different energy delivery methods: monopolar ablation, bipolar ablation, and non-ablation energy. Treatment outcomes were compared with control specimens as to clinical endpoint and histopomorphic characteristics. Fibrillated cartilage was removed in all specimens; however, the residual tissue remaining at the treatment site displayed significantly different characteristics attributable to radiofrequency energy delivery method. Systems that delivered ablation-based energies caused tissue necrosis and collateral damage at the treatment site including corruption of cartilage Superficial and Transitional Zones; whereas, the non-ablation system created a smooth articular surface with Superficial Zone maintenance and without chondrocyte death or tissue necrosis. The mechanism of radiofrequency energy deposition upon tissues is particularly important in treatment settings requiring tissue preservation. Ablation-based device systems can cause a worsened state of articular cartilage from that of pre-treatment. Non-ablation energy can be successful in modifying/preconditioning tissue during débridement chondroplasty without causing collateral damage. Utilizing a non-ablation radiofrequency system provides the ability to perform successful débridement chondroplasty without causing additional articular cartilage tissue damage and may allow for other cartilage intervention success. PMID:20721322

DNA Damage Response Is Involved in the Developmental Toxicity of Mebendazole in Zebrafish Retina

PubMed Central

Sasagawa, Shota; Nishimura, Yuhei; Kon, Tetsuo; Yamanaka, Yukiko; Murakami, Soichiro; Ashikawa, Yoshifumi; Yuge, Mizuki; Okabe, Shiko; Kawaguchi, Koki; Kawase, Reiko; Tanaka, Toshio

2016-01-01

Intestinal helminths cause iron-deficiency anemia in pregnant women, associated with premature delivery, low birth weight, maternal ill health, and maternal death. Although benzimidazole compounds such as mebendazole (MBZ) are highly efficacious against helminths, there are limited data on its use during pregnancy. In this study, we performed in vivo imaging of the retinas of zebrafish larvae exposed to MBZ, and found that exposure to MBZ during 2 and 3 days post-fertilization caused malformation of the retinal layers. To identify the molecular mechanism underlying the developmental toxicity of MBZ, we performed transcriptome analysis of zebrafish eyes. The analysis revealed that the DNA damage response was involved in the developmental toxicity of MBZ. We were also able to demonstrate that inhibition of ATM significantly attenuated the apoptosis induced by MBZ in the zebrafish retina. These results suggest that MBZ causes developmental toxicity in the zebrafish retina at least partly by activating the DNA damage response, including ATM signaling, providing a potential adverse outcome pathway in the developmental toxicity of MBZ in mammals. PMID:27014071

Barbiturate euthanasia solution-induced tissue artifact in nonhuman primates.

PubMed

Grieves, J L; Dick, E J; Schlabritz-Loutsevich, N E; Butler, S D; Leland, M M; Price, S E; Schmidt, C R; Nathanielsz, P W; Hubbard, G B

2008-06-01

Barbiturate euthanasia solutions are a humane and approved means of euthanasia. Overdosing causes significant tissue damage in a variety of laboratory animals. One hundred seventeen non-human primates (NHP) representing 7 species including 12 fetuses euthanized for humane and research reasons by various vascular routes with Euthasol, Sodium Pentobarbital, Fatal Plus, Beuthanasia D, or Euthanasia 5 were evaluated for euthanasia-induced tissue damage. Lungs and livers were histologically graded for hemolysis, vascular damage, edema, and necrosis. Severity of tissue damage was analyzed for differences on the basis of agent, age, sex, dose, and injection route. Severity of tissue damage was directly related to dose and the intracardiac injection route, but did not differ by species, sex, and agent used. When the recommended dose of agent was used, tissue damage was generally reduced, minimal, or undetectable. Barbiturate-induced artifacts in NHPs are essentially the same as in other laboratory species.

The penumbra of thalidomide, the litigation culture and the licensing of pharmaceuticals

PubMed Central

2012-01-01

Fifty years ago several thousand children were born with severe limb defects after their mothers had been given thalidomide in pregnancy. This tragedy caused procedures for licensing new medicines to become much stricter. Where, nevertheless, significant side effects were found it became common to sue for damages. These consequences have caused possibly an even greater disaster damaging many more people and threatening ruin to health services everywhere. The huge increase in both time and cost in bringing medicines to market is increasing their price to unsupportable levels; and only wealthy companies are now able to do so. This requires reform as does litigation for ‘statistical’ harmful effects. PMID:22908318

Differential genotoxicity of diphenyl diselenide (PhSe)2 and diphenyl ditelluride (PhTe)2

PubMed Central

Meinerz, Daiane Francine; Allebrandt, Josiane; Mariano, Douglas O.C.; Waczuk, Emily P.; Soares, Felix Antunes

2014-01-01

Organoselenium compounds have been pointed out as therapeutic agents. In contrast, the potential therapeutic aspects of tellurides have not yet been demonstrated. The present study evaluated the comparative toxicological effects of diphenyl diselenide (PhSe)2 and diphenyl ditelluride (PhTe)2 in mice after in vivo administration. Genotoxicity (as determined by comet assay) and mutagenicicity were used as end-points of toxicity. Subcutaneous administration of high doses of (PhSe)2 or (PhTe)2 (500 µmol/kg) caused distinct genotoxicity in mice. (PhSe)2 significantly decreased the DNA damage index after 48 and 96 h of its injection (p < 0.05). In contrast, (PhTe) caused a significant increase in DNA damage (p < 0.05) after 48 and 96 h of intoxication. (PhSe)2 did not cause mutagenicity but (PhTe)2 increased the micronuclei frequency, indicating its mutagenic potential. The present study demonstrated that acute in vivo exposure to ditelluride caused genotoxicity in mice, which may be associated with pro-oxidant effects of diphenyl ditelluride. In addition, the use of this compound and possibly other related tellurides must be carefully controlled. PMID:24711962

Acoustic characteristics of Dynastid beetle stridulations

USDA-ARS?s Scientific Manuscript database

Oryctes rhinoceros (L.) (Coleoptera: Scarabaeidae: Dynastinae) causes economically important damage to ornamental and commercial coconut palm trees in the western Pacific region that could be mitigated significantly by early detection and treatment. Adults are difficult to detect visually, however...

The effects of Mucuna pruriens extract on histopathological and biochemical features in the rat model of ischemia.

PubMed

Nayak, Vanishri S; Kumar, Nitesh; D'Souza, Antony S; Nayak, Sunil S; Cheruku, Sri P; Pai, K Sreedhara Ranganath

2017-12-13

Stroke is considered to be one of the most important causes of death worldwide. Global ischemia causes widespread brain injury and infarctions in various regions of the brain. Oxidative stress can be considered an important factor in the development of tissue damage, which is caused because of arterial occlusion with subsequent reperfusion. Kapikacchu or Mucuna pruriens, commonly known as velvet bean, is well known for its aphrodisiac activities. It is also used in the treatment of snakebites, depressive neurosis, and Parkinson's disease. Although this plant has different pharmacological actions, its neuroprotective activity has received minimal attention. Thus, this study was carried out with the aim of evaluating the neuroprotective action of M. pruriens in bilateral carotid artery occlusion-induced global cerebral ischemia in Wistar rats. The carotid arteries of both sides were occluded for 30 min and reperfused to induce global cerebral ischemia. The methanolic plant extract was administered to the study animals for 10 days. The brains of the Wistar rats were isolated by decapitation and observed for histopathological and biochemical changes. Cerebral ischemia resulted in significant neurological damage in the brains of the rats that were not treated by M. pruriens. The group subjected to treatment by the M. pruriens extract showed significant protection against brain damage compared with the negative control group, which indicates the therapeutic potential of this plant in ischemia.

Evaluation of eyes with relative pupillary block by indentation ultrasound biomicroscopy gonioscopy.

PubMed

Matsunaga, Koichi; Ito, Kunio; Esaki, Koji; Sugimoto, Kota; Sano, Toru; Miura, Katsuya; Sasoh, Mikio; Uji, Yukitaka

2004-03-01

To investigate changes in anterior chamber angle configuration with indentation ultrasound biomicroscopy gonioscopy of relative pupillary block (RPB). Cross-sectional study. This study included 26 eyes of 26 patients with RPB. We determined angle opening distance 500 and angle recess area using indentation ultrasound biomicroscopy gonioscopy and compared a small-sized standard eye cup with a new eye cup with an area for inducing pressure. Indentation ultrasound biomicroscopy images documented concavity of the iris in eyes with RPB. Both the new and the small standard eye cups widened the anterior chamber angle significantly (P <.0001) without causing corneal damage. Angle changes were significantly greater for the new eye cup design. Indentation ultrasound biomicroscopy gonioscopy is a useful technique for observation and diagnosis of RPB. Using a small standard or the newly designed eye cup, the procedure can be performed easily and without causing corneal damage.

Prevention of psychological stress-induced immune suppression by aged garlic extract.

PubMed

Kyo, E; Uda, N; Ushijima, M; Kasuga, S; Itakura, Y

1999-11-01

We determined the effect of Aged Garlic Extract (AGE) on damage caused to immune function by a psychological stress using a communication box. After four days of a psychological stress, a decrease in spleen weight and spleen cells was observed in the psychological stress-exposed mice as compared normal mice (non-stress). AGE significantly prevented the decreases in spleen weight and cells. Additionally, AGE significantly prevented the reduction of hemolytic plaque-forming-cells in spleen cells and anti-SRBC antibody titer in serum caused by this psychological stress. Moreover, a reduction in NK activities was observed in the psychological stress-exposed mice as compared with normal mice (non-stress), whereas NK activities in the AGE administered mice were almost the same as normal mice (non-stress). These results indicate that psychological stress qualitatively and quantitatively impairs immune function, and that AGE is extremely useful for preventing psychologically-induced damage.

Organizational strategy influence on visual memory performance after stroke: cortical/subcortical and left/right hemisphere contrasts.

PubMed

Lange, G; Waked, W; Kirshblum, S; DeLuca, J

2000-01-01

To examine how organizational strategy at encoding influences visual memory performance in stroke patients. Case control study. Postacute rehabilitation hospital. Stroke patients with right hemisphere damage (n = 20) versus left hemisphere damage (n = 15), and stroke patients with cortical damage (n = 11) versus subcortical damage (n = 19). Organizational strategy scores, recall performance on the Rey-Osterrieth Complex Figure (ROCF). Results demonstrated significantly greater organizational impairment and less accurate copy performance (i.e., encoding of visuospatial information on the ROCF) in the right compared to the left hemisphere group, and in the cortical relative to the subcortical group. Organizational strategy and copy accuracy scores were significantly related to each other. The absolute amount of immediate and delayed recall was significantly associated with poor organizational strategy scores. However, relative to the amount of visual information originally encoded, memory performances did not differ between groups. These findings suggest that visual memory impairments after stroke may be caused by a lack of organizational strategy affecting information encoding, rather than an impairment in memory storage or retrieval.

The evaluation of the genotoxicity of two food preservatives: sodium benzoate and potassium benzoate.

PubMed

Zengin, N; Yüzbaşıoğlu, D; Unal, F; Yılmaz, S; Aksoy, H

2011-04-01

In this study, the genotoxic effects of sodium benzoate (SB) and potassium benzoate (PB) were investigated in cultured human peripheral lymphocytes using chromosomal aberrations (CA), sister chromatid exchange (SCE), and micronuclei (MN). The level of nuclear DNA damage of SB and PB were also evaluated using the comet assay. The lymphocytes were incubated with different concentrations of SB (6.25, 12.5, 25, 50, and 100 μg/ml) and PB (62.5, 125, 250, 500, and 1000 μg/ml). A significant increase was observed in CA, SCE, and MN, in almost all treatments compared to negative controls. SB and PB significantly decreased the mitotic index (MI) in all the treatments, compared to the negative controls. However, neither of the additives affected the replication index (RI). Although SB significantly increased DNA damage, PB did not cause a significant increase in DNA damage. The present results indicate that SB and PB are clastogenic, mutagenic and cytotoxic to human lymphocytes in vitro. Copyright © 2010 Elsevier Ltd. All rights reserved.

Oxidative DNA damage and mammary cell proliferation by alcohol-derived salsolinol.

PubMed

Murata, Mariko; Midorikawa, Kaoru; Kawanishi, Shosuke

2013-10-21

Drinking alcohol is a risk factor for breast cancer. Salsolinol (SAL) is endogenously formed by a condensation reaction of dopamine with acetaldehyde, a major ethanol metabolite, and SAL is detected in blood and urine after alcohol intake. We investigated the possibility that SAL can participate in tumor initiation and promotion by causing DNA damage and cell proliferation, leading to alcohol-associated mammary carcinogenesis. SAL caused oxidative DNA damage including 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), in the presence of transition metal ions, such as Cu(II) and Fe(III)EDTA. Inhibitory effects of scavengers on SAL-induced DNA damage and the electron spin resonance study indicated the involvement of H₂O₂, which is generated via the SAL radical. Experiments on scavengers and site specificity of DNA damage suggested ·OH generation via a Fenton reaction and copper-peroxide complexes in the presence of Fe(III)EDTA and Cu(II), respectively. SAL significantly increased 8-oxodG formation in normal mammary epithelial MCF-10A cells. In addition, SAL induced cell proliferation in estrogen receptor (ER)-negative MCF-10A cells, and the proliferation was inhibited by an antioxidant N-acetylcysteine and an epidermal growth factor receptor (EGFR) inhibitor AG1478, suggesting that reactive oxygen species may participate in the proliferation of MCF-10A cells via EGFR activation. Furthermore, SAL induced proliferation in estrogen-sensitive breast cancer MCF-7 cells, and a surface plasmon resonance sensor revealed that SAL significantly increased the binding activity of ERα to the estrogen response element but not ERβ. In conclusion, SAL-induced DNA damage and cell proliferation may play a role in tumor initiation and promotion of multistage mammary carcinogenesis in relation to drinking alcohol.

Oxidative Burst of Circulating Neutrophils Following Traumatic Brain Injury in Human

PubMed Central

Liao, Yiliu; Liu, Peng; Guo, Fangyuan; Zhang, Zhi-Yuan; Zhang, Zhiren

2013-01-01

Besides secondary injury at the lesional site, Traumatic brain injury (TBI) can cause a systemic inflammatory response, which may cause damage to initially unaffected organs and potentially further exacerbate the original injury. Here we investigated plasma levels of important inflammatory mediators, oxidative activity of circulating leukocytes, particularly focusing on neutrophils, from TBI subjects and control subjects with general trauma from 6 hours to 2 weeks following injury, comparing with values from uninjured subjects. We observed increased plasma level of inflammatory cytokines/molecules TNF-α, IL-6 and CRP, dramatically increased circulating leukocyte counts and elevated expression of TNF-α and iNOS in circulating leukocytes from TBI patients, which suggests a systemic inflammatory response following TBI. Our data further showed increased free radical production in leukocyte homogenates and elevated expression of key oxidative enzymes iNOS, COX-2 and NADPH oxidase (gp91phox) in circulating leukocytes, indicating an intense induction of oxidative burst following TBI, which is significantly greater than that in control subjects with general trauma. Furthermore, flow cytometry assay proved neutrophils as the largest population in circulation after TBI and showed significantly up-regulated oxidative activity and suppressed phagocytosis rate for circulating neutrophils following brain trauma. It suggests that the highly activated neutrophils might play an important role in the secondary damage, even outside the injured brain. Taken together, the potent systemic inflammatory response induced by TBI, especially the intensively increase oxidative activity of circulating leukocytes, mainly neutrophils, may lead to a systemic damage, dysfunction/damage of bystander tissues/organs and even further exacerbate secondary local damage. Controlling these pathophysiological processes may be a promising therapeutic strategy and will protect unaffected organs and the injured brain from the secondary damage. PMID:23894384

Nucleus Accumbens Invulnerability to Methamphetamine Neurotoxicity

PubMed Central

Kuhn, Donald M.; Angoa-Pérez, Mariana; Thomas, David M.

2016-01-01

Methamphetamine (Meth) is a neurotoxic drug of abuse that damages neurons and nerve endings throughout the central nervous system. Emerging studies of human Meth addicts using both postmortem analyses of brain tissue and noninvasive imaging studies of intact brains have confirmed that Meth causes persistent structural abnormalities. Animal and human studies have also defined a number of significant functional problems and comorbid psychiatric disorders associated with long-term Meth abuse. This review summarizes the salient features of Meth-induced neurotoxicity with a focus on the dopamine (DA) neuronal system. DA nerve endings in the caudate-putamen (CPu) are damaged by Meth in a highly delimited manner. Even within the CPu, damage is remarkably heterogeneous, with ventral and lateral aspects showing the greatest deficits. The nucleus accumbens (NAc) is largely spared the damage that accompanies binge Meth intoxication, but relatively subtle changes in the disposition of DA in its nerve endings can lead to dramatic increases in Meth-induced toxicity in the CPu and overcome the normal resistance of the NAc to damage. In contrast to the CPu, where DA neuronal deficiencies are persistent, alterations in the NAc show a partial recovery. Animal models have been indispensable in studies of the causes and consequences of Meth neurotoxicity and in the development of new therapies. This research has shown that increases in cytoplasmic DA dramatically broaden the neurotoxic profile of Meth to include brain structures not normally targeted for damage. The resistance of the NAc to Meth-induced neurotoxicity and its ability to recover reveal a fundamentally different neuroplasticity by comparison to the CPu. Recruitment of the NAc as a target of Meth neurotoxicity by alterations in DA homeostasis is significant in light of the numerous important roles played by this brain structure. PMID:23382149

Nucleus accumbens invulnerability to methamphetamine neurotoxicity.

PubMed

Kuhn, Donald M; Angoa-Pérez, Mariana; Thomas, David M

2011-01-01

Methamphetamine (Meth) is a neurotoxic drug of abuse that damages neurons and nerve endings throughout the central nervous system. Emerging studies of human Meth addicts using both postmortem analyses of brain tissue and noninvasive imaging studies of intact brains have confirmed that Meth causes persistent structural abnormalities. Animal and human studies have also defined a number of significant functional problems and comorbid psychiatric disorders associated with long-term Meth abuse. This review summarizes the salient features of Meth-induced neurotoxicity with a focus on the dopamine (DA) neuronal system. DA nerve endings in the caudate-putamen (CPu) are damaged by Meth in a highly delimited manner. Even within the CPu, damage is remarkably heterogeneous, with ventral and lateral aspects showing the greatest deficits. The nucleus accumbens (NAc) is largely spared the damage that accompanies binge Meth intoxication, but relatively subtle changes in the disposition of DA in its nerve endings can lead to dramatic increases in Meth-induced toxicity in the CPu and overcome the normal resistance of the NAc to damage. In contrast to the CPu, where DA neuronal deficiencies are persistent, alterations in the NAc show a partial recovery. Animal models have been indispensable in studies of the causes and consequences of Meth neurotoxicity and in the development of new therapies. This research has shown that increases in cytoplasmic DA dramatically broaden the neurotoxic profile of Meth to include brain structures not normally targeted for damage. The resistance of the NAc to Meth-induced neurotoxicity and its ability to recover reveal a fundamentally different neuroplasticity by comparison to the CPu. Recruitment of the NAc as a target of Meth neurotoxicity by alterations in DA homeostasis is significant in light of the numerous important roles played by this brain structure.

Human Impacts on Coral Reefs in the Sultanate of Oman

NASA Astrophysics Data System (ADS)

Al-Jufaili, S.; Al-Jabri, M.; Al-Baluchi, A.; Baldwin, R. M.; Wilson, S. C.; West, F.; Matthews, A. D.

1999-08-01

A rapid assessment survey of the coral reefs of the Sultanate of Oman was conducted by the Ministry of Regional Municipalities and Environment during the first half of 1996. The survey revealed new information on the distribution pattern of corals in Oman and identified impacts, threats and potential threats to coral communities for the purpose of preparation of a National Coral Reef Management Plan (Phase One of the implementation of a National Coastal Zone Management Plan). Impacts on coral reefs in Oman were found to be attributable to both natural and human causes, resulting in significant and widespread degradation. Damage resulting from fisheries activities was the most commonly recorded human impact, with the most severe effects. Other human impacts resulted from coastal construction, recreational activities, oil pollution and eutrophication. Predation of corals by Acanthaster planci, damage caused by storms, coral diseases and temperature-related stress were the most commonly recorded natural impacts to coral reefs. Further minor natural impacts were attributable to siltation, rock falls and predation by a corallivorous gastropod (Drupella sp.). Significant differences between different areas of the country were found in terms of human impacts on coral reefs and these were related to coastal demography and human activity. Eighty per cent of sites studied were recorded to have been affected by human impacts to some degree. Impacts attributable to fisheries activities were found at 69% of the sites. Lost or abandoned gill nets were found to affect coral reefs at 49% of sites throughout Oman and accounted for 70% of all severe human impacts. Lost gill nets were also found to have a negative affect on fisheries resources and other marine wildlife. Observations of the behaviour of gill nets on coral reefs suggested a predictable pattern of damage over time and a significant increase in damage intensity during storms. Fishing nets were found to act selectively, causing greater damage to certain coral communities than to others. Results of the study are discussed in relation to management of coral reef areas in Oman.

Dandelion-enriched diet of mothers alleviates lead-induced damages in liver of newborn rats.

PubMed

Gargouri, M; Magné, C; Ben Amara, I; Ben Saad, H; El Feki, A

2017-02-28

Lead (Pb) is a highly toxic metal present in the environment. It causes disturbances of several functions, including hematologic, renal, reproductive and nervous ones. Preventive or curative use of medicinal plants against these disorders may be a promising and safe therapeutic strategy. This study evaluated the hepatic toxic effects of prenatal exposure to lead in rats and the possible protective effect of dandelion (Taraxacum officinale) added to the diet. Female rats were given a normal diet (control) or a diet enriched with dandelion (treated). In addition, lead acetate was administered to half of the rats through drinking water from the 5th day of gestation until the 14th day postpartum. Lead toxicity was evaluated in their offspring by measuring body and liver weights, plasma biochemical parameters, liver damage, as well as protein content and activities of antioxidant enzymes in the liver tissues. Lead poisoning of mothers caused lead deposition in blood and stomach of their pups as well as hepatic tissue damages. Moreover, significant decreases in liver weight and protein content were found. Lead treatment caused oxidative stress and marked changes in the activity of antioxidant enzymes. However, no damages or biochemical changes were observed in puppies from the rats co-treated with lead and dandelion. These results indicate that supplementation of pregnant and lactating rats with dandelion protects their offspring against lead poisoning, likely through reduction of oxidative stress and liver damages.

Functional lacrimal gland regeneration by transplantation of a bioengineered organ germ

PubMed Central

Hirayama, Masatoshi; Ogawa, Miho; Oshima, Masamitsu; Sekine, Yurie; Ishida, Kentaro; Yamashita, Kentaro; Ikeda, Kazutaka; Shimmura, Shigeto; Kawakita, Tetsuya; Tsubota, Kazuo; Tsuji, Takashi

2013-01-01

The lacrimal gland has a multifaceted role in maintaining a homeostatic microenvironment for a healthy ocular surface via tear secretion. Dry-eye disease, which is caused by lacrimal gland dysfunction, is one of the most prevalent eye diseases that cause corneal epithelial damage and results in significant loss of vision and a reduction in the quality of life. Here we demonstrate orthotopic transplantation of bioengineered lacrimal gland germs into adult mice with an extra-orbital lacrimal gland defect, a mouse model that mimics the corneal epithelial damage caused by lacrimal gland dysfunction. The bioengineered lacrimal gland germs and harderian gland germs both develop in vivo and achieve sufficient physiological functionality, including tear production in response to nervous stimulation and ocular surface protection. This study demonstrates the potential for bioengineered organ replacement to functionally restore the lacrimal gland. PMID:24084941

Exploration of COTS Ultrasonic NDE Methods for ISS MMOD Impact Analysis

NASA Technical Reports Server (NTRS)

Violette, Daniel P.; Koshti, Ajay; Stanley, David

2012-01-01

The high orbital speed of the International Space Station (ISS) has created a concern about Micro-Meteorite and Orbital Debris (MMOD). The possibility exists that such an impact could cause significant damage to the ISS pressure wall, and possibly lead to a pressure leak. This paper explores the potential of using commercial off-the-shelf (COTS) Ultrasonic Non-Destructive Evaluation (NDE) techniques in order to inspect and analyze MMOD impact damage if such an event would happen to occur. Different types of intra vehicular activity (IVA) Ultrasonic NDE equipment were evaluated, including the Olympus Omniscan MX and the General Electric Phasor XS. The equipment was tested by inspecting various aluminum standards and impact damage test plates in order to determine technological limitations of the equipment as well as the ease of use and availability of features. This study allowed for the design of scanning procedures in order to evaluate the extent of damage caused by an MMOD impact. Lastly, comparisons were drawn between the different pieces of COTS software and a recommendation is made based on each device s capability.

Dopamine disposition in the presynaptic process regulates the severity of methamphetamine-induced neurotoxicity.

PubMed

Kuhn, Donald M; Francescutti-Verbeem, Dina M; Thomas, David M

2008-10-01

Methamphetamine (METH) is well known for its ability to cause damage to dopamine (DA) nerve endings of the striatum. The mechanisms by which METH causes neurotoxicity are not fully understood, but likely candidates are increased oxidative and nitrosative stress and mitochondrial dysfunction. Microglial activation is also emerging as an important element of the METH neurotoxic cascade, and it appears that extensive cross-talk between these cells and DA nerve endings is an early event in this process. It may seem paradoxical, but DA itself is also thought to be an essential factor in the neuronal damaging effects of METH, but issues relating to its precise role in this regard remain unanswered. We present in this overview a summary of studies that tested how alterations in the disposition of presynaptic DA (injections of reserpine, L-DOPA, or clorgyline) modulate METH neurotoxicity. In all cases, these drugs significantly increased the magnitude of microglial activation as well as the severity of damage to striatal DA nerve endings caused by METH. The enhancement of METH effects in striatum by reserpine, L-DOPA, and clorgyline persisted for 14 days and showed no evidence of recovery. These data establish that subtle shifts in the newly synthesized pool of DA can cause substantial changes in the severity of METH-induced neurotoxicity. DA released into the synapse by METH is very likely the source of downstream reactants that provoke microglial activation and the ensuing damage to DA nerve endings.

Assessing Hurricane Katrina Vegetation Damage at Stennis Space Center using IKONOS Image Classification Techniques

NASA Technical Reports Server (NTRS)

Spruce, Joseph P.; Ross, Kenton W.; Graham, William D.

2007-01-01

Hurricane Katrina hit southwestern Mississippi on August 29, 2005, at 9:45 a.m. CDT as a category 3 storm with surges up to approx. 9 m and sustained winds of approx. 120 mph. The hurricane's wind, rain, and flooding devastated several coastal towns, from New Orleans through Mobile. The storm also caused significant damage to infrastructure and vegetation of NASA's SSC (Stennis Space Center). Storm recovery at SSC involved not only repairs of critical infrastructure but also forest damage mitigation (via timber harvests and control burns to reduce fire risk). This presentation discusses an effort to use commercially available high spatial resolution multispectral IKONOS data for vegetation damage assessment, based on data collected over SSC on September 2, 2005.

In Pursuit of Improving Airburst and Ground Damage Predictions: Recent Advances in Multi-Body Aerodynamic Testing and Computational Tools Validation

NASA Technical Reports Server (NTRS)

Venkatapathy, Ethiraj; Gulhan, Ali; Aftosmis, Michael; Brock, Joseph; Mathias, Donovan; Need, Dominic; Rodriguez, David; Seltner, Patrick; Stern, Eric; Wiles, Sebastian

2017-01-01

An airburst from a large asteroid during entry can cause significant ground damage. The damage depends on the energy and the altitude of airburst. Breakup of asteroids into fragments and their lateral spread have been observed. Modeling the underlying physics of fragmented bodies interacting at hypersonic speeds and the spread of fragments is needed for a true predictive capability. Current models use heuristic arguments and assumptions such as pancaking or point source explosive energy release at pre-determined altitude or an assumed fragmentation spread rate to predict airburst damage. A multi-year collaboration between German Aerospace Center (DLR) and NASA has been established to develop validated computational tools to address the above challenge.

Summary of the Effects of Two Years of Hygro-Thermal Cycling on a Carbon/Epoxy Composite Material

NASA Technical Reports Server (NTRS)

Kohlman, Lee W.; Binienda, Wieslaw K.; Roberts, Gary D.; Miller, Sandi G.; Pereira, J. Michael; Bail, Justin L.

2011-01-01

Composite materials are beginning to be used for structures in the fan section of commercial gas turbine engines. This paper explores the type of damage that could occur within one type of composite material after exposure to hygrothermal cycles (temperature/humidity cycles) that are representative of the environment in the fan section of an engine. The effect of this damage on composite material properties is measured. Chemical changes in the matrix material were limited to the exposed surface. Microcrack formation was identified in the composite material. This damage did not cause a significant reduction in tensile strength or impact penetration resistance of the composite material. Additional data is needed to assess the effect of damage on compressive strength.

Hepatoprotective activity of dried- and fermented-processed virgin coconut oil.

PubMed

Zakaria, Z A; Rofiee, M S; Somchit, M N; Zuraini, A; Sulaiman, M R; Teh, L K; Salleh, M Z; Long, K

2011-01-01

The present study aims to determine the hepatoprotective effect of MARDI-produced virgin coconut oils, prepared by dried- or fermented-processed methods, using the paracetamol-induced liver damage in rats. Liver injury induced by 3 g/kg paracetamol increased the liver weight per 100 g bodyweight indicating liver damage. Histological observation also confirms liver damage indicated by the presence of inflammations and necrosis on the respective liver section. Interestingly, pretreatment of the rats with 10, but not 1 and 5, mL/kg of both VCOs significantly (P < .05) reduced the liver damage caused by the administration of paracetamol, which is further confirmed by the histological findings. In conclusion, VCO possessed hepatoprotective effect that requires further in-depth study.

Hepatoprotective Activity of Dried- and Fermented-Processed Virgin Coconut Oil

PubMed Central

Zakaria, Z. A.; Rofiee, M. S.; Somchit, M. N.; Zuraini, A.; Sulaiman, M. R.; Teh, L. K.; Salleh, M. Z.; Long, K.

2011-01-01

The present study aims to determine the hepatoprotective effect of MARDI-produced virgin coconut oils, prepared by dried- or fermented-processed methods, using the paracetamol-induced liver damage in rats. Liver injury induced by 3 g/kg paracetamol increased the liver weight per 100 g bodyweight indicating liver damage. Histological observation also confirms liver damage indicated by the presence of inflammations and necrosis on the respective liver section. Interestingly, pretreatment of the rats with 10, but not 1 and 5, mL/kg of both VCOs significantly (P < .05) reduced the liver damage caused by the administration of paracetamol, which is further confirmed by the histological findings. In conclusion, VCO possessed hepatoprotective effect that requires further in-depth study. PMID:21318140

Seismic Indexing System for Army Installations. Volume II. Seismic Hazard Priority-Ranking Procedure for Army Buildings: Basic Concept.

DTIC Science & Technology

1981-05-01

factors that cause damage are discussed below. a. Architectural elements. Damage to architectural elements can result in both significant dollar losses...hazard priority- ranking procedure are: 1. To produce meaningful results which are as simple as possible, con- sidering the existing databases. 2. To...minimize the amount of data required for meaningful results , i.e., the database should contain only the most fundamental building characteris- tics. 3. To

Role of inflammation in the development of renal damage and dysfunction in Angiotensin II-induced hypertension

PubMed Central

Liao, Tang-Dong; Yang, Xiao-Ping; Liu, Yun-He; Shesely, Edward G.; Cavasin, Maria A.; Kuziel, William A.; Pagano, Patrick J.; Carretero, Oscar A.

2008-01-01

Angiotensin II (Ang II)-induced hypertension is associated with an inflammatory response that may contribute to development of target organ damage. We tested the hypothesis that in Angiotensin II-induced hypertension, CC chemokine receptor 2 (CCR2) activation plays an important role in development of renal fibrosis, damage and dysfunction by causing: a) oxidative stress, b) macrophage infiltration, and c) cell proliferation. To test this hypothesis we used CCR2 knockout mice (CCR2−/−). The natural ligand of CCR2 is monocyte chemoattractant protein-1 (MCP-1), a chemokine important for macrophage recruitment and activation. CCR2−/− and age-matched wild-type (CCR2+/+) C57BL/6J mice were infused continuously with either Ang II (5.2 ng/10 g/min) or vehicle via osmotic mini-pumps for 2 or 4 weeks. Ang II infusion caused similar increases in systolic blood pressure and left ventricular hypertrophy in both strains of mice. However, in CCR2−/− mice with Ang II-induced hypertension, oxidative stress, macrophage infiltration, albuminuria and renal damage were significantly decreased and glomerular filtration rate was significantly higher than in CCR2+/+ mice. We concluded that in Ang II-induced hypertension, CCR2 activation plays an important role in development of hypertensive nephropathy via increased oxidative stress and inflammation. PMID:18541733

Nanoparticles can cause DNA damage across a cellular barrier

NASA Astrophysics Data System (ADS)

Bhabra, Gevdeep; Sood, Aman; Fisher, Brenton; Cartwright, Laura; Saunders, Margaret; Evans, William Howard; Surprenant, Annmarie; Lopez-Castejon, Gloria; Mann, Stephen; Davis, Sean A.; Hails, Lauren A.; Ingham, Eileen; Verkade, Paul; Lane, Jon; Heesom, Kate; Newson, Roger; Case, Charles Patrick

2009-12-01

The increasing use of nanoparticles in medicine has raised concerns over their ability to gain access to privileged sites in the body. Here, we show that cobalt-chromium nanoparticles (29.5 +/- 6.3 nm in diameter) can damage human fibroblast cells across an intact cellular barrier without having to cross the barrier. The damage is mediated by a novel mechanism involving transmission of purine nucleotides (such as ATP) and intercellular signalling within the barrier through connexin gap junctions or hemichannels and pannexin channels. The outcome, which includes DNA damage without significant cell death, is different from that observed in cells subjected to direct exposure to nanoparticles. Our results suggest the importance of indirect effects when evaluating the safety of nanoparticles. The potential damage to tissues located behind cellular barriers needs to be considered when using nanoparticles for targeting diseased states.

Dam-Break Flooding and Structural Damage in a Residential Neighborhood: Performance of a coupled hydrodynamic-damage model

NASA Astrophysics Data System (ADS)

Sanders, B. F.; Gallegos, H. A.; Schubert, J. E.

2011-12-01

The Baldwin Hills dam-break flood and associated structural damage is investigated in this study. The flood caused high velocity flows exceeding 5 m/s which destroyed 41 wood-framed residential structures, 16 of which were completed washed out. Damage is predicted by coupling a calibrated hydrodynamic flood model based on the shallow-water equations to structural damage models. The hydrodynamic and damage models are two-way coupled so building failure is predicted upon exceedance of a hydraulic intensity parameter, which in turn triggers a localized reduction in flow resistance which affects flood intensity predictions. Several established damage models and damage correlations reported in the literature are tested to evaluate the predictive skill for two damage states defined by destruction (Level 2) and washout (Level 3). Results show that high-velocity structural damage can be predicted with a remarkable level of skill using established damage models, but only with two-way coupling of the hydrodynamic and damage models. In contrast, when structural failure predictions have no influence on flow predictions, there is a significant reduction in predictive skill. Force-based damage models compare well with a subset of the damage models which were devised for similar types of structures. Implications for emergency planning and preparedness as well as monetary damage estimation are discussed.

Inhibitory effect and possible mechanism of a Pseudomonas strain QBA5 against gray mold on tomato leaves and fruits caused by Botrytis cinerea

PubMed Central

Gao, Pan; Qin, Jiaxing; Li, Delong

2018-01-01

The fungal pathogen Botrytis cinerea causes gray mold disease on various hosts, which results in serious economic losses. Over the past several decades, many kinds of fungicides have been used to successfully control the disease. Meanwhile, the uses of fungicides lead to environmental pollution as well as a potential threat to the human health by the chemical residues in tomato fruit. Also, the gray mold disease is difficult to control with fungicides. Therefore, exploring alternative measures such as biological controls could be the best choice to control the disease and alleviate damages caused by fungicides. In this study, we isolated and identified a novel Pseudomonas strain termed as QBA5 from healthy tomato plant based on the morphological, biochemical characteristics and molecular detection. The antifungal activity assays revealed that, in the presence of QBA5, conidia germination, germ tube elongation and mycelial growth of B. cinerea were significantly inhibited. Most importantly, QBA5 exerted a significant preventive effectiveness against gray mold on tomato fruits and plants. The possible mechanism of QBA5 involved in the inhibition of B. cinerea was investigated. It revealed that the conidia plasma membrane of B. cinerea was severely damaged by QBA5. Further, four different antifungal compounds in the supernatant of QBA5 were separated by preparative high performance liquid chromatography (PHPLC). Overall, the data indicate that there is a considerable potential for QBA5 to reduce the damage caused by gray mold disease on tomato. PMID:29320571

Cardiac changes after simulated behind armor blunt trauma or impact of nonlethal kinetic projectile ammunition.

PubMed

Kunz, Sebastian N; Arborelius, Ulf P; Gryth, Dan; Sonden, Anders; Gustavsson, Jenny; Wangyal, Tashi; Svensson, Leif; Rocksén, David

2011-11-01

Cardiac-related injuries caused by blunt chest trauma remain a severe problem. The aim of this study was to investigate pathophysiological changes in the heart that might arise after behind armor blunt trauma or impacts of nonlethal projectiles. Sixteen pigs were shot directly at the sternum with "Sponge Round eXact I Mpact" (nonlethal ammunition; diameter 40 mm and weight 28 g) or hard-plastic ammunition (diameter 65 mm and weight 58 g) to simulate behind armor blunt trauma. To evaluate the influence of the shot location, seven additional pigs where exposed to an oblique heart shot. Physiologic parameters, electrocardiography, echocardiogram, the biochemical marker troponin I (TnI), and myocardial injuries were analyzed. Nonlethal kinetic projectiles (101-108 m/s; 143-163 J) did not cause significant pathophysiological changes. Five of 18 pigs shot with 65-mm plastic projectiles (99-133 m/s; 284-513 J) to the front or side of the thorax died directly after the shot. No major physiologic changes could be observed in surviving animals. Animals shot with an oblique heart shot (99-106 m/s; 284-326 J) demonstrated a small, but significant decrease in saturation. Energy levels over 300 J caused increased TnI and myocardial damages in most of the pigs. This study indicates that nonlethal kinetic projectiles "eXact iMpact" does not cause heart-related damage under the examined conditions. On impact, sudden heart arrest may occur independently from the cardiac's electrical cycle. The cardiac enzyme, TnI, can be used as a reliable diagnostic marker to detect heart tissue damages after blunt chest trauma.

Inhibitory effect and possible mechanism of a Pseudomonas strain QBA5 against gray mold on tomato leaves and fruits caused by Botrytis cinerea.

PubMed

Gao, Pan; Qin, Jiaxing; Li, Delong; Zhou, Shanyue

2018-01-01

The fungal pathogen Botrytis cinerea causes gray mold disease on various hosts, which results in serious economic losses. Over the past several decades, many kinds of fungicides have been used to successfully control the disease. Meanwhile, the uses of fungicides lead to environmental pollution as well as a potential threat to the human health by the chemical residues in tomato fruit. Also, the gray mold disease is difficult to control with fungicides. Therefore, exploring alternative measures such as biological controls could be the best choice to control the disease and alleviate damages caused by fungicides. In this study, we isolated and identified a novel Pseudomonas strain termed as QBA5 from healthy tomato plant based on the morphological, biochemical characteristics and molecular detection. The antifungal activity assays revealed that, in the presence of QBA5, conidia germination, germ tube elongation and mycelial growth of B. cinerea were significantly inhibited. Most importantly, QBA5 exerted a significant preventive effectiveness against gray mold on tomato fruits and plants. The possible mechanism of QBA5 involved in the inhibition of B. cinerea was investigated. It revealed that the conidia plasma membrane of B. cinerea was severely damaged by QBA5. Further, four different antifungal compounds in the supernatant of QBA5 were separated by preparative high performance liquid chromatography (PHPLC). Overall, the data indicate that there is a considerable potential for QBA5 to reduce the damage caused by gray mold disease on tomato.

The effects of wind and temperature on cuticular transpiration of Picea abies and Pinus cembra and their significance in dessication damage at the alpine treeline.

PubMed

Baig, M N; Tranquillini, W

1980-01-01

The importance of high winter winds and plant temperatures as causes of winter desiccation damage at the alpine treeline were studied in the Austrian Alps. Samples of 1- and 2-year twigs of Picea abies and Pinus cembra were collected from the valley bottom (1,000 m a.s.l.), forestline (1,940 m a.s.l.), kampfzone (2.090 m a.s.l.), wind-protected treeline (2,140 m a.s.l.), and wind-exposed treeline (2,140 m a.s.l.). Cuticular transpiration was measured at three different levels of wind speed (4, 10, and 15 ms -1 ) and temperature (15°, 20°, and 25° C). At elevated wind speeds slight increases in water loss were observed, whereas at higher temperatures much greater increases occurred. Studies on winter water relations show a significant decline in the actual moisture content and osmotic potentials of twigs, especially in the kampfzone and at treeline. The roles of high winds and temperatures in depleting the winter water economy and causing desiccation damage in the alpine treeline environment are discussed.

Measurement of traffic network vulnerability for Mississippi coastal region : final research report.

DOT National Transportation Integrated Search

2017-08-15

Natural disasters such as a hurricane can cause great damages to the transportation networks and significantly affect the evacuation trip operations. An accurate understanding and measurement of the network vulnerability can enhance the evacuees p...

Developing a bridge scour warning system : technical summary.

DOT National Transportation Integrated Search

2016-09-01

Flooding and scour can be major threats to the integrity of bridges. During flood events, : scour at bridge piers and abutments can undermine the foundations of the bridge, causing : significant damage or even total structure loss. Because scour occu...

Developing a bridge scour warning system : final report.

DOT National Transportation Integrated Search

2016-09-01

Flooding and scour can be major threats to the integrity of bridges. During flood events, scour at bridge piers : and abutments can undermine the foundations of the bridge, causing significant damage or even total structure loss. : Because scour occu...

Erosion and lateral surface processes

USDA-ARS?s Scientific Manuscript database

: Erosion can cause serious agricultural and environmental hazards. It can generate severe damage to the landscape, lead to significant loss of agricultural land and consequently to reduction in agricultural productivity, induce surface water pollution due to the transport of sediments and suspende...

Effects of 17beta-estradiol, and its metabolite, 4-hydroxyestradiol on fertilization, embryo development and oxidative DNA damage in sand dollar (Dendraster excentricus) sperm.

PubMed

Rempel, Mary Ann; Hester, Brian; Deharo, Hector; Hong, Haizheng; Wang, Yinsheng; Schlenk, Daniel

2009-03-15

Oxidative compounds have been demonstrated to decrease the fertilization capability and viability of offspring of treated spermatozoa. As estrogen and its hydroxylated metabolites readily undergo redox cycling, this study was undertaken to determine if estrogens and other oxidants could damage DNA and impair sperm function. Sperm was preexposed to either 17beta-estradiol (E2), 4-hydroxyestradiol (4OHE2) or the oxidant t-butyl hydroperoxide (t-BOOH), and allowed to fertilize untreated eggs. The fertilization rates and development of the larvae were assessed, as well as the amount of 8-oxodeoxyguanosine (8-oxodG) as an indication of oxidative DNA damage. All compounds caused significant decreases in fertilization and increases in pathological abnormalities in offspring, with 4OHE2 being the most toxic. Treatment with 4OHE2 caused a significant increase of 8-oxodG, but E2 failed to show any effect. Pathological abnormalities were significantly correlated (r(2)=0.44, p< or =0.05) with 8-oxodG levels in sperm treated with t-BOOH and 4OHE2, but not E2. 8-OxodG levels also were somewhat weakly correlated with impaired fertilization in 4OHE2-treated sperm (r(2)=0.33, p< or =0.05). The results indicate that biotransformation of E2 to 4OHE2 enhances oxidative damage of DNA in sperm, which can reduce fertilization and impair embryonic development, but other mechanisms of action may also contribute to these effects.

Effects of 17β-estradiol, and its metabolite, 4-hydroxyestradiol on fertilization, embryo development and oxidative DNA damage in sand dollar (Dendraster excentricus) sperm

PubMed Central

Rempel, Mary Ann; Hester, Brian; DeHaro, Hector; Hong, Haizheng; Wang, Yinsheng; Schlenk, Daniel

2011-01-01

Oxidative compounds have been demonstrated to decrease the fertilization capability and viability of offspring of treated spermatozoa. As estrogen and its hydroxylated metabolites readily undergo redox cycling, this study was undertaken to determine if estrogens and other oxidants could damage DNA and impair sperm function. Sperm was preexposed to either 17β-estradiol (E2), 4-hydroxyestradiol (4OHE2) or the oxidant t-butyl hydroperoxide (t-BOOH), and allowed to fertilize untreated eggs. The fertilization rates and development of the larvae were assessed, as well as the amount of 8-oxodeoxyguanosine (8-oxodG) as an indication of oxidative DNA damage. All compounds caused significant decreases in fertilization and increases in pathological abnormalities in offspring, with 4OHE2 being the most toxic. Treatment with 4OHE2 caused a significant increase of 8-oxodG, but E2 failed to show any effect. Pathological abnormalities were significantly correlated (r2 = 0.44, p ≤ 0.05) with 8-oxodG levels in sperm treated with t-BOOH and 4OHE2, but not E2. 8-OxodG levels also were somewhat weakly correlated with impaired fertilization in 4OHE2-treated sperm (r2 = 0.33, p ≤ 0.05). The results indicate that biotransformation of E2 to 4OHE2 enhances oxidative damage of DNA in sperm, which can reduce fertilization and impair embryonic development, but other mechanisms of action may also contribute to these effects. PMID:19171371

Sinking coastal cities

NASA Astrophysics Data System (ADS)

Erkens, G.; Bucx, T.; Dam, R.; de Lange, G.; Lambert, J.

2015-11-01

In many coastal and delta cities land subsidence now exceeds absolute sea level rise up to a factor of ten. A major cause for severe land subsidence is excessive groundwater extraction related to rapid urbanization and population growth. Without action, parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other coastal cities will sink below sea level. Land subsidence increases flood vulnerability (frequency, inundation depth and duration of floods), with floods causing major economic damage and loss of lives. In addition, differential land movement causes significant economic losses in the form of structural damage and high maintenance costs for (infra)structure. The total damage worldwide is estimated at billions of dollars annually. As subsidence is often spatially variable and can be caused by multiple processes, an assessment of subsidence in delta cities needs to answer questions such as: what are the main causes? What is the current subsidence rate and what are future scenarios (and interaction with other major environmental issues)? Where are the vulnerable areas? What are the impacts and risks? How can adverse impacts be mitigated or compensated for? Who is involved and responsible to act? In this study a quick-assessment of subsidence is performed on the following mega-cities: Jakarta, Ho Chi Minh City, Dhaka, New Orleans and Bangkok. Results of these case studies will be presented and compared, and a (generic) approach how to deal with subsidence in current and future subsidence-prone areas is provided.

Pseudomonas aeruginosa rugose small-colony variants evade host clearance, are hyper-inflammatory, and persist in multiple host environments.

PubMed

Pestrak, Matthew J; Chaney, Sarah B; Eggleston, Heather C; Dellos-Nolan, Sheri; Dixit, Sriteja; Mathew-Steiner, Shomita S; Roy, Sashwati; Parsek, Matthew R; Sen, Chandan K; Wozniak, Daniel J

2018-02-01

Pseudomonas aeruginosa causes devastating infections in immunocompromised individuals. Once established, P. aeruginosa infections become incredibly difficult to treat due to the development of antibiotic tolerant, aggregated communities known as biofilms. A hyper-biofilm forming clinical variant of P. aeruginosa, known as a rugose small-colony variant (RSCV), is frequently isolated from chronic infections and is correlated with poor clinical outcome. The development of these mutants during infection suggests a selective advantage for this phenotype, but it remains unclear how this phenotype promotes persistence. While prior studies suggest RSCVs could survive by evading the host immune response, our study reveals infection with the RSCV, PAO1ΔwspF, stimulated an extensive inflammatory response that caused significant damage to the surrounding host tissue. In both a chronic wound model and acute pulmonary model of infection, we observed increased bacterial burden, host tissue damage, and a robust neutrophil response during RSCV infection. Given the essential role of neutrophils in P. aeruginosa-mediated disease, we investigated the impact of the RSCV phenotype on neutrophil function. The RSCV phenotype promoted phagocytic evasion and stimulated neutrophil reactive oxygen species (ROS) production. We also demonstrate that bacterial aggregation and TLR-mediated pro-inflammatory cytokine production contribute to the immune response to RSCVs. Additionally, RSCVs exhibited enhanced tolerance to neutrophil-produced antimicrobials including H2O2 and the antimicrobial peptide LL-37. Collectively, these data indicate RSCVs elicit a robust but ineffective neutrophil response that causes significant host tissue damage. This study provides new insight on RSCV persistence, and indicates this variant may have a critical role in the recurring tissue damage often associated with chronic infections.

A Review: Some biological effects of high LET radiations

NASA Technical Reports Server (NTRS)

Wiley, A., Jr.

1972-01-01

There are qualitative and quantitative differences in the biological damage observed after exposure to high LET radiation as compared to that caused by low LET radiations. This review is concerned with these differences, which are ultimately reflected at the biochemical, cellular and even whole animal levels. In general, high LET radiations seem to produce biochemical damage which is more severe and possibly less repairable. Experimental data for those effects are presented in terms of biochemical RBE's with consideration of both early and late manifestations. An LET independent process by which significant biochemical damage may result from protons, neutrons and negative pion mesons is discussed.

Study of the damage rate caused by intervertebral foramen type inside and outside and the pass of the intervertebral DRG RF puncture way.

PubMed

Sun, Jiashu; Zhang, Haitao

2014-09-01

This paper was to analyze and contrast the damage rate on the thoracic segment different position of the dorsal root ganglion(dorsal root ganglion, DRG) caused by different puncture path in radiofrequency ablation, thus the best RF target way for the thoracic segment of different types of DRG was confirmed. According to the difference of puncture and ablation damage way, 14 segmental spinal specimens were randomly divided into three groups, and then conducted DRG radiofrequency damage on percutaneous puncture path according to the type of DRG position.The damage effect of different puncture path by the judgment standard of the result of pathology analyzed. The experiment showed that RF damage of group A were 72.58 ± 18.88%, 54.16 ± 24.84% and 32.85 ± 28.11%; that of group B were 771.86 ± 15.15% and 72.02 ± 17.86%, 57.14 ± 18.02% and 52.47 ± 20.64%, 68.75 ± 14.63% and 71.78 ± 16.00%; and that of group C were 82.46 ± 14.10%, 81.53 ± 11.81% and 80.83 ± 13.33%. It was concluded that the singleness of DRG puncture route is one of the important reasons for the poor thoracic segments DRG radiofrequency (RF) ablation effect. While according to the type of DRG different positions with double joint puncture path can significantly improve the rate of DRG RF damage.

New Satellite Damage Maps Assist Italy Earthquake Disaster Response

NASA Image and Video Library

2016-09-01

Italy earthquake. The quake has caused significant damage in the historic town of Amatrice. To assist in the disaster response efforts, scientists at NASA's Jet Propulsion Laboratory, Pasadena, California, and the California Institute of Technology in Pasadena, in collaboration with the Italian Space Agency (ASI), generated this image of the earthquake's hardest-hit region. The 40-by-75 mile (65-by-120 kilometer) Damage Proxy Map (DPM) was derived from two consecutive frames of the Japan Aerospace Exploration Agency's (JAXA's) L-band interferometric synthetic aperture radar (InSAR) data from the ALOS-2 satellite (cyan rectangles), and the 25-by-31 mile (40-by-50 kilometer) DPM was derived from InSAR data from the Agenzia Spaciale Italiana's (ASI's) X-band COSMO-SkyMed satellite (red rectangle). Both DPMs cover the historic town of Amatrice, revealing severe damage in the western side of the town (right panels). The time span of the data for the change is Jan. 27, 2016 to Aug. 24, 2016 for ALOS-2 and Aug. 20, 2016 to Aug. 28, 2016 for COSMO-SkyMed. Each pixel in the damage proxy map is about 100 feet (30 meters) across. The SAR data were processed by the Advanced Rapid Imaging and Analysis (ARIA) team at JPL and Caltech. The technique uses a prototype algorithm to rapidly detect surface changes caused by natural or human-produced damage. The assessment technique is most sensitive to destruction of the built environment. When the radar images areas with little to no destruction, its image pixels are transparent. Increased opacity of the radar image pixels reflects damage, with areas in red reflecting the heaviest damage to cities and towns. The color variations from yellow to red indicate increasingly more significant ground surface change. Preliminary validation was done by comparing the DPMs to a damage assessment map produced by the Copernicus Emergency Management Service, which is based on visual inspection of before and after high-resolution aerial imagery -- the extent indicated with gray boxes in the left panel. http://photojournal.jpl.nasa.gov/catalog/PIA20897

Acute organo-phosphorus pesticide poisoning in North Karnataka, India: oxidative damage, haemoglobin level and total leukocyte.

PubMed

Hundekari, I A; Suryakar, A N; Rathi, D B

2013-03-01

Pesticide poisoning is an important cause of morbidity and mortality in India. To assess the oxidative damage, hemoglobin level and leukocyte count in acute organophosphorus pesticide poisoning. Plasma cholinesterase was assessed as a toxicity marker. Oxidative damage was assessed by estimating serum malondialdehyde (MDA) levels, plasma total antioxidant capacity (TAC), erythrocyte superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) levels. Progressive and significant decline (p< 0.001) in plasma cholinesterase in correlation with the severity of organophosphorus poisoning was observed. Serum MDA levels significantly increased (p< 0.001) in all grades of organophosphorus poisoning cases as compared to controls. Erythrocyte SOD, CAT and GPx were significantly increased (p< 0.05) in earlier grade and (p< 0.001) in later grades of organophosphorus poisoning cases as compared to controls. While plasma TAC (p<0.001) was significantly decreased in all grades of organophosphorus poisoning cases as compared to controls. Leucocytosis observed in these cases signifies the activation of defense mechanism which could be a positive response for survival. Organophosphorus compounds inhibit cholinesterase action leading to cholinergic hyperactivity. Increased MDA level may lead to peroxidative damages deteriorating the structural and functional integrity of neuronal membrane. Increased erythrocyte SOD, CAT and GPx activities suggest an adaptive measure to tackle the pesticide accumulation. Hence it is concluded that cholinesterase inhibition may initiate cellular dysfunction leading to acetylcholine induced oxidative damage.

Evaluation of DNA-damaging potential of bisphenol A and its selected analogs in human peripheral blood mononuclear cells (in vitro study).

PubMed

Mokra, Katarzyna; Kuźmińska-Surowaniec, Agnieszka; Woźniak, Katarzyna; Michałowicz, Jaromir

2017-02-01

In the present study, we have investigated DNA-damaging potential of BPA and its analogs, i.e. bisphenol S (BPS), bisphenol F (BPF) and bisphenol AF (BPAF) in human peripheral blood mononuclear cells (PBMCs) using the alkaline and neutral versions of the comet assay, which allowed to evaluate DNA single strand-breaks (SSBs) and double strand-breaks (DSBs). The use of the alkaline version of comet assay made also possible to analyze the kinetics of DNA repair in PBMCs after exposure of the cells to BPA or its analogs. We have observed an increase in DNA damage in PBMCs treated with BPA or its analogs in the concentrations ranging from 0.01 to 10 μg/ml after 1 and 4 h incubation. It was noted that bisphenols studied caused DNA damage mainly via SSBs, while DNA fragmentation via double DSBs was low. The strongest changes in DNA damage were provoked by BPA and particularly BPAF, which were capable of inducing SSBs even at 0.01 μg/ml, while BPS caused the lowest changes (only at 10 μg/ml). We have also observed that PBMCs significantly repaired bisphenols-induced DNA damage but they were unable (excluding cells treated with BPS) to repair totally DNA breaks. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Pitfalls in informed consent: a statistical analysis of malpractice law suits].

PubMed

Echigo, Junko

2014-05-01

In medical malpractice law suits, the notion of informed consent is often relevant in assessing whether negligence can be attributed to the medical practitioner who has caused injury to a patient. Furthermore, it is not rare that courts award damages for a lack of appropriate informed consent alone. In this study, two results were arrived at from a statistical analysis of medical malpractice law suits. One, unexpectedly, was that the severity of a patient's illness made no significant difference to whether damages were awarded. The other was that cases of typical medical treatment that national medical insurance does not cover were involved significantly more often than insured treatment cases. In cases where damages were awarded, the courts required more disclosure and written documents of information by medical practitioners, especially about complications and adverse effects that the patient might suffer.

Antifungal defense of probiotic Lactobacillus rhamnosus GG is mediated by blocking adhesion and nutrient depletion

PubMed Central

Braunsdorf, Christina; Grumaz, Christian; Müller, Christoph; Lorenz, Stefan; Stevens, Philip; Wagener, Jeanette; Hebecker, Betty; Hube, Bernhard; Bracher, Franz; Sohn, Kai; Schaller, Martin

2017-01-01

Candida albicans is an inhabitant of mucosal surfaces in healthy individuals but also the most common cause of fungal nosocomial blood stream infections, associated with high morbidity and mortality. As such life-threatening infections often disseminate from superficial mucosal infections we aimed to study the use of probiotic Lactobacillus rhamnosus GG (LGG) in prevention of mucosal C. albicans infections. Here, we demonstrate that LGG protects oral epithelial tissue from damage caused by C. albicans in our in vitro model of oral candidiasis. Furthermore, we provide insights into the mechanisms behind this protection and dissect direct and indirect effects of LGG on C. albicans pathogenicity. C. albicans viability was not affected by LGG. Instead, transcriptional profiling using RNA-Seq indicated dramatic metabolic reprogramming of C. albicans. Additionally, LGG had a significant impact on major virulence attributes, including adhesion, invasion, and hyphal extension, whose reduction, consequently, prevented epithelial damage. This was accompanied by glucose depletion and repression of ergosterol synthesis, caused by LGG, but also due to blocked adhesion sites. Therefore, LGG protects oral epithelia against C. albicans infection by preventing fungal adhesion, invasion and damage, driven, at least in parts, by metabolic reprogramming due to nutrient limitation caused by LGG. PMID:29023454

Hepatoprotective activity of sea cucumber Phyllophorus sp. extract in carp (Cyprinus carpio)

NASA Astrophysics Data System (ADS)

Sulmartiwi, Laksmi; Triastuti, Juni; Andriyono, Sapto; Umami, Mardiah Rahma

2017-02-01

Many procedures continuously in aquaculture and scientific research like tagging and vaccinating cause pain, involving damaging tissue and also cause stress responses in fish. Stress responses in fish influence liver because liver have vital role to supply energy and metabolism. Histology alteration in liver is caused by stress response like changes of vacuolation hepatocyte and characteristic colour. Triterpenoid was known had hepatoprotective activity. One of marine organism contained triterpenoid was sea cucumber. Result of research showed that liver tissue in fish with injected acetic acid 5 % (in upper lip) as pain stimulus have histopathology damages such as pyknosis (medium damage level) and oedema (heavy damage level) after 8 hour injection. Injected Lidocaine 1mg/fish as analgesic drug have histopathology damages such as oedema (heavy damages level), necrosis and pyknosis (low damages level). Injected acetic acid 5 % (in upper lip) and ethanolic extract of sea cucumber Phyllophorus sp. dose 5 mg/50 gr body weight shown histopathology damages such as necrosis, edema (medium damage level) and pyknosis (low damage level).

Interactions between low energy electrons and DNA: a perspective from first-principles simulations

NASA Astrophysics Data System (ADS)

Kohanoff, Jorge; McAllister, Maeve; Tribello, Gareth A.; Gu, Bin

2017-09-01

DNA damage caused by irradiation has been studied for many decades. Such studies allow us to better assess the dangers posed by radiation, and to increase the efficiency of the radiotherapies that are used to combat cancer. A full description of the irradiation process involves multiple size and time scales. It starts with the interaction of radiation—either photons or swift ions—and the biological medium, which causes electronic excitation and ionisation. The two main products of ionising radiation are thus electrons and radicals. Both of these species can cause damage to biological molecules, in particular DNA. In the long run, this molecular level damage can prevent cells from replicating and can hence lead to cell death. For a long time it was assumed that the main actors in the damage process were the radicals. However, experiments in a seminal paper by the group of Leon Sanche in 2000 showed that low-energy electrons (LEE), such as those generated when ionising biological targets, can also cause bond breaks in biomolecules, and strand breaks in plasmid DNA in particular (Boudaiffa et al 2000 Science 287 1658-60). These results prompted a significant amount of experimental and theoretical work aimed at elucidating the role played by LEE in DNA damage. In this Topical Review we provide a general overview of the problem. We discuss experimental findings and theoretical results hand in hand with the aim of describing the physics and chemistry that occurs during the process of radiation damage, from the initial stages of electronic excitation, through the inelastic propagation of electrons in the medium, the interaction of electrons with DNA, and the chemical end-point effects on DNA. A very important aspect of this discussion is the consideration of a realistic, physiological environment. The role played by the aqueous solution and the amino acids from the histones in chromatin must be considered. Moreover, thermal fluctuations must be incorporated when studying these phenomena. Hence, a special place in this Topical Review is occupied by our recent first-principles molecular dynamics simulations that address the issue of how the environment favours or prevents LEEs from causing damage to DNA. We finish by summarising the conclusions achieved so far, and by suggesting a number of possible directions for further study.

Interactions between low energy electrons and DNA: a perspective from first-principles simulations.

PubMed

Kohanoff, Jorge; McAllister, Maeve; Tribello, Gareth A; Gu, Bin

2017-09-27

DNA damage caused by irradiation has been studied for many decades. Such studies allow us to better assess the dangers posed by radiation, and to increase the efficiency of the radiotherapies that are used to combat cancer. A full description of the irradiation process involves multiple size and time scales. It starts with the interaction of radiation-either photons or swift ions-and the biological medium, which causes electronic excitation and ionisation. The two main products of ionising radiation are thus electrons and radicals. Both of these species can cause damage to biological molecules, in particular DNA. In the long run, this molecular level damage can prevent cells from replicating and can hence lead to cell death. For a long time it was assumed that the main actors in the damage process were the radicals. However, experiments in a seminal paper by the group of Leon Sanche in 2000 showed that low-energy electrons (LEE), such as those generated when ionising biological targets, can also cause bond breaks in biomolecules, and strand breaks in plasmid DNA in particular (Boudaiffa et al 2000 Science 287 1658-60). These results prompted a significant amount of experimental and theoretical work aimed at elucidating the role played by LEE in DNA damage. In this Topical Review we provide a general overview of the problem. We discuss experimental findings and theoretical results hand in hand with the aim of describing the physics and chemistry that occurs during the process of radiation damage, from the initial stages of electronic excitation, through the inelastic propagation of electrons in the medium, the interaction of electrons with DNA, and the chemical end-point effects on DNA. A very important aspect of this discussion is the consideration of a realistic, physiological environment. The role played by the aqueous solution and the amino acids from the histones in chromatin must be considered. Moreover, thermal fluctuations must be incorporated when studying these phenomena. Hence, a special place in this Topical Review is occupied by our recent first-principles molecular dynamics simulations that address the issue of how the environment favours or prevents LEEs from causing damage to DNA. We finish by summarising the conclusions achieved so far, and by suggesting a number of possible directions for further study.

INHIBITION OF FRIED MEAT-INDUCED DNA DAMAGE: A DIETARY INTERVENTION STUDY IN HUMANS

EPA Science Inventory

Dietary exposures have been implicated as risk factors in colorectal cancer. Such agents may act by causing DNA damage or may be protective against DNA damage. The effects of dietary exposures in causing or preventing damage have not been assessed directly in colon tissues. In th...

Identification of sandstone core damage using scanning electron microscopy

NASA Astrophysics Data System (ADS)

Ismail, Abdul Razak; Jaafar, Mohd Zaidi; Sulaiman, Wan Rosli Wan; Ismail, Issham; Shiunn, Ng Yinn

2017-12-01

Particles and fluids invasion into the pore spaces causes serious damage to the formation, resulting reduction in petroleum production. In order to prevent permeability damage for a well effectively, the damage mechanisms should be identified. In this study, water-based drilling fluid was compared to oil-based drilling fluids based on microscopic observation. The cores were damaged by several drilling fluid systems. Scanning electron microscope (SEM) was used to observe the damage mechanism caused by the drilling fluids. Results showed that the ester based drilling fluid system caused the most serious damage followed by synthetic oil based system and KCI-polymer system. Fine solids and filtrate migration and emulsion blockage are believed to be the major mechanisms controlling the changes in flow properties for the sandstone samples.

Gamma-Ray Bursts and the Earth: Exploration of Atmospheric, Biological, Climatic, and Biogeochemical Effects

NASA Astrophysics Data System (ADS)

Thomas, Brian C.; Melott, Adrian L.; Jackman, Charles H.; Laird, Claude M.; Medvedev, Mikhail V.; Stolarski, Richard S.; Gehrels, Neil; Cannizzo, John K.; Hogan, Daniel P.; Ejzak, Larissa M.

2005-11-01

Gamma-ray bursts (GRBs) are likely to have made a number of significant impacts on the Earth during the last billion years. The gamma radiation from a burst within a few kiloparsecs would quickly deplete much of the Earth's protective ozone layer, allowing an increase in solar UVB radiation reaching the surface. This radiation is harmful to life, damaging DNA and causing sunburn. In addition, NO2 produced in the atmosphere would cause a decrease in visible sunlight reaching the surface and could cause global cooling. Nitric acid rain could stress portions of the biosphere, but the increased nitrate deposition could be helpful to land plants. We have used a two-dimensional atmospheric model to investigate the effects on the Earth's atmosphere of GRBs delivering a range of fluences, at various latitudes, at the equinoxes and solstices, and at different times of day. We have estimated DNA damage levels caused by increased solar UVB radiation, reduction in solar visible light due to NO2 opacity, and deposition of nitrates through rainout of HNO3. For the ``typical'' nearest burst in the last billion years, we find globally averaged ozone depletion up to 38%. Localized depletion reaches as much as 74%. Significant global depletion (at least 10%) persists up to about 7 yr after the burst. Our results depend strongly on time of year and latitude over which the burst occurs. The impact scales with the total fluence of the GRB at the Earth but is insensitive to the time of day of the burst and its duration (1-1000 s). We find DNA damage of up to 16 times the normal annual global average, well above lethal levels for simple life forms such as phytoplankton. The greatest damage occurs at mid- to low latitudes. We find reductions in visible sunlight of a few percent, primarily in the polar regions. Nitrate deposition similar to or slightly greater than that currently caused by lightning is also observed, lasting several years. We discuss how these results support the hypothesis that the Late Ordovician mass extinction may have been initiated by a GRB.

Importance of secondary damage in downer cows.

PubMed

Poulton, P J; Vizard, A L; Anderson, G A; Pyman, M F

2016-05-01

To investigate the relative importance in downer cows of the primary cause of recumbency in comparison with secondary complications. Downer dairy cows were monitored during their recumbency under field conditions in South Gippsland, Victoria, Australia. The cause of the original recumbency of the 218 cows was determined and secondary damage, status on day 7 and final outcome were recorded. Some type of secondary damage was found in 183/218 (84%) cows, of which 173/218 (79%) had damage deemed to be clinically important. By day 7, 52 (24%) had recovered and 69 (32%) eventually recovered. Of the 149 (68%) cows that were euthanased or died, 23 (15%) were deemed to have been lost solely from the primary cause, 107 (72%) from secondary damage and 19 (13%) from a combination of both. There was no difference in recovery among the five broad groups of causes of primary recumbency. Secondary damage was very common and presented in a large variety of ways, with many cows having multiple types of secondary damage concurrently. For most cows the secondary damage was more important than the initial primary damage in determining their fate. © 2016 Australian Veterinary Association.

Ballistics reviews: mechanisms of bullet wound trauma.

PubMed

Maiden, Nicholas

2009-01-01

The location of an entrance wound (bullet placement) and the projectile path are the most important factors in causing significant injury or death following a shooting. The head followed by the torso are the most vulnerable areas, with incapacitation resulting from central nervous system (brain or cord) disruption, or massive organ destruction with hemorrhage. Tissue and organ trauma result from the permanent wound cavity caused by direct destruction by the bullet, and also from radial stretching of surrounding tissues causing a temporary wound cavity. The extent of tissue damage is influenced by the type of bullet, its velocity and mass, as well as the physical characteristics of the tissues. The latter includes resistance to strain, physical dimensions of an organ, and the presence or absence of surrounding anatomical constraints. Bullet shape and construction will also affect tissue damage and bullets which display greater yaw will be associated with increased temporary cavitation. Military bullet designs do not include bullets that will expand or flatten as these cause greater wound trauma and are regulated by convention.

Atmospheric skin aging-Contributors and inhibitors.

PubMed

McDaniel, David; Farris, Patricia; Valacchi, Giuseppe

2018-04-01

Cutaneous aging is a complex biological process consisting of 2 elements: intrinsic aging, which is primarily determined by genetics, and extrinsic aging, which is largely caused by atmospheric factors, such as exposure to sunlight and air pollution, and lifestyle choices, such as diet and smoking. The role of the solar spectrum, comprised of ultraviolet light, specifically UVB (290-320 nm) and UVA (320-400) in causing skin damage, including skin cancers, has been well documented. In recent years, the contribution of visible light (400-700 nm) and infrared radiation (above 800 nm) in causing skin damage, similar to the photodamage caused by UV light, is also being elucidated. In addition, other atmospheric factors such as air pollution (smog, ozone, particulate matter, etc.) have been implicated in premature skin aging. The skin damage caused by environmental exposure is largely attributable to a complex cascade of reactions inside the skin initiated by the generation of reactive oxygen species (ROS), which causes oxidative damage to cellular components such as proteins, lipids, and nucleic acids. These damaged skin cells initiate inflammatory responses leading to the eventual damage manifested in chronically exposed skin. Novel therapeutic strategies to combat ROS species generation are being developed to prevent the skin damage caused by atmospheric factors. In addition to protecting skin from solar radiation using sunscreens, other approaches using topically applied ingredients, particularly antioxidants that penetrate the skin and protect the skin from within, have also been well documented. This review summarizes current knowledge of atmospheric aggressors, including UVA, UVB, visible light, infrared radiation (IR), and ozone on skin damage, and proposes new avenues for future research in the prevention and treatment of premature skin aging caused by such atmospheric factors. New therapeutic modalities currently being developed are also discussed. © 2018 Wiley Periodicals, Inc.

Estimation on rubber tree disturbance caused by typhoon Damery (200518) with Landsat and MODIS data in Hainan Island of China

NASA Astrophysics Data System (ADS)

Tan, Chenyan; Fang, Weihua; Li, Jian

2016-04-01

In 2005, Typhoon Damery (200518) caused severe damage to the rubber trees in Hainan Island with its destructive winds and rainfall. Selection of proper vegetation indices using multi-source remote sensing data is critical to the assessment of forest disturbance and damage loss for this event. In this study, we will compare the performance of seven vegetation indices derived from MODIS and Landsat TM imageries prior to and after typhoon Damery, in order to select an optimal index for identifying rubber tree disturbance. The indices to be compared are normalized difference vegetation index (NDVI), Normalized Difference Water Index (NDWI), Normalized Difference Infrared Index (NDII), Enhanced vegetation index (EVI), Leaf area index (LAI), forest z-score (IFZ), and Disturbance Index (DI). The ground truth data of rubber tree damage collected through field investigation was used to verify and compare the results. Our preliminary result for the area with ground-truth data shows that DI has the most significant performance for disturbance detection for this typhoon event. This index DI is then applied to all the areas in Hainan Island hit by Darmey to evaluate the overall forest damage severity. At last, rubber tree damage severity is analyzed with other typhoon hazard factors such as wind, topography, soil and precipitation.

A new progeroid syndrome reveals that genotoxic stress suppresses the somatotroph axis.

PubMed

Niedernhofer, Laura J; Garinis, George A; Raams, Anja; Lalai, Astrid S; Robinson, Andria Rasile; Appeldoorn, Esther; Odijk, Hanny; Oostendorp, Roos; Ahmad, Anwaar; van Leeuwen, Wibeke; Theil, Arjan F; Vermeulen, Wim; van der Horst, Gijsbertus T J; Meinecke, Peter; Kleijer, Wim J; Vijg, Jan; Jaspers, Nicolaas G J; Hoeijmakers, Jan H J

2006-12-21

XPF-ERCC1 endonuclease is required for repair of helix-distorting DNA lesions and cytotoxic DNA interstrand crosslinks. Mild mutations in XPF cause the cancer-prone syndrome xeroderma pigmentosum. A patient presented with a severe XPF mutation leading to profound crosslink sensitivity and dramatic progeroid symptoms. It is not known how unrepaired DNA damage accelerates ageing or its relevance to natural ageing. Here we show a highly significant correlation between the liver transcriptome of old mice and a mouse model of this progeroid syndrome. Expression data from XPF-ERCC1-deficient mice indicate increased cell death and anti-oxidant defences, a shift towards anabolism and reduced growth hormone/insulin-like growth factor 1 (IGF1) signalling, a known regulator of lifespan. Similar changes are seen in wild-type mice in response to chronic genotoxic stress, caloric restriction, or with ageing. We conclude that unrepaired cytotoxic DNA damage induces a highly conserved metabolic response mediated by the IGF1/insulin pathway, which re-allocates resources from growth to somatic preservation and life extension. This highlights a causal contribution of DNA damage to ageing and demonstrates that ageing and end-of-life fitness are determined both by stochastic damage, which is the cause of functional decline, and genetics, which determines the rates of damage accumulation and decline.

Possible involvement of GABAergic mechanism in protective effect of melatonin against sleep deprivation-induced behaviour modification and oxidative damage in mice.

PubMed

Kumar, Anil; Singh, Anant

2009-08-01

Sleep is an important physiological process responsible for the maintenance of physical, mental and emotional health of a living being. Sleep deprivation is considered risky for several pathological diseases such as anxiety and motor and cognitive dysfunctions. Sleep deprivation has recently been reported to cause oxidative damage. This study has been designed to explore the possible involvement of the GABAergic mechanism in protective effects of melatonin against 72-h sleep deprivation-induced behaviour modification and oxidative damage in mice. Mice were sleep-deprived for a period of 72 h using the grid over water suspended method. Animals were divided into groups of 6-8 animals each. Melatonin (5 and 10 mg/kg), flumazenil (0.5 mg/kg), picrotoxin (0.5 mg/kg) and muscimol (0.05 mg/kg) were administered for 5 days starting 2 days before 72-h sleep deprivation. Various behavioural tests (plus maze, zero maze, mirror chamber, actophotometer) and body weight assessment followed by oxidative stress parameters (malondialdehyde level, glutathione, catalase, nitrite and protein) were carried out. The 72-h sleep deprivation caused significant anxiety-like behaviour, weight loss, impaired locomotor activity and oxidative damage as compared with naïve (without sleep deprivation). Treatment with melatonin (5 mg/kg and 10 mg/kg, ip) significantly improved locomotor activity, weight loss and antianxiety effect as compared with control (sleep-deprived). Biochemically, melatonin treatment significantly restored reduced glutathione, catalase activity, attenuated lipid peroxidation and nitrite level as compared with control animals (72-h sleep-deprived). Flumazenil (0.5 mg/kg) and picrotoxin (0.5 mg/kg) pretreatments with a lower dose of melatonin (5 mg/kg) significantly antagonized the protective effect of melatonin. However, muscimol (0.05 mg/kg) pretreatment with melatonin (5 mg/kg, ip) potentiated the protective effect of melatonin which was significant as compared with their effect per se. This study suggests that GABAergic modulation is involved in the protective action of melatonin against sleep deprivation-induced anxiety-like behaviour and associated oxidative damage.

Insects attacking black walnut in the midwestern United States

Treesearch

Steven Katovich

2004-01-01

Black walnut has only a handful of insects that would be considered significant pests. Of the leaf feeders, the walnut caterpillar is the most likely to cause significant defoliation and damage to trees. However, severe infestations are infrequent and tend to be restricted to small geographic areas. Two other commonly encountered defoliators are the yellow necked...

Sensitivity of spiral ganglion neurons to damage caused by mobile phone electromagnetic radiation will increase in lipopolysaccharide-induced inflammation in vitro model.

PubMed

Zuo, Wen-Qi; Hu, Yu-Juan; Yang, Yang; Zhao, Xue-Yan; Zhang, Yuan-Yuan; Kong, Wen; Kong, Wei-Jia

2015-05-29

With the increasing popularity of mobile phones, the potential hazards of radiofrequency electromagnetic radiation (RF-EMR) on the auditory system remain unclear. Apart from RF-EMR, humans are also exposed to various physical and chemical factors. We established a lipopolysaccharide (LPS)-induced inflammation in vitro model to investigate whether the possible sensitivity of spiral ganglion neurons to damage caused by mobile phone electromagnetic radiation (at specific absorption rates: 2, 4 W/kg) will increase. Spiral ganglion neurons (SGN) were obtained from neonatal (1- to 3-day-old) Sprague Dawley® (SD) rats. After the SGN were treated with different concentrations (0, 20, 40, 50, 100, 200, and 400 μg/ml) of LPS, the Cell Counting Kit-8 (CCK-8) and alkaline comet assay were used to quantify cellular activity and DNA damage, respectively. The SGN were treated with the moderate LPS concentrations before RF-EMR exposure. After 24 h intermittent exposure at an absorption rate of 2 and 4 W/kg, DNA damage was examined by alkaline comet assay, ultrastructure changes were detected by transmission electron microscopy, and expression of the autophagy markers LC3-II and Beclin1 were examined by immunofluorescence and confocal laser scanning microscopy. Reactive oxygen species (ROS) production was quantified by the dichlorofluorescin-diacetate assay. LPS (100 μg/ml) induced DNA damage and suppressed cellular activity (P < 0.05). LPS (40 μg/ml) did not exhibit cellular activity changes or DNA damage (P > 0.05); therefore, 40 μg/ml was used to pretreat the concentration before exposure to RF-EMR. RF-EMR could not directly induce DNA damage. However, the 4 W/kg combined with LPS (40 μg/ml) group showed mitochondria vacuoles, karyopyknosis, presence of lysosomes and autophagosome, and increasing expression of LC3-II and Beclin1. The ROS values significantly increased in the 4 W/kg exposure, 4 W/kg combined with LPS (40 μg/ml) exposure, and H2O2 groups (P < 0.05, 0.01). Short-term exposure to radiofrequency electromagnetic radiation could not directly induce DNA damage in normal spiral ganglion neurons, but it could cause the changes of cellular ultrastructure at special SAR 4.0 W/kg when cells are in fragile or micro-damaged condition. It seems that the sensitivity of SGN to damage caused by mobile phone electromagnetic radiation will increase in a lipopolysaccharide-induced inflammation in vitro model.

Detecting Damage in Composite Material Using Nonlinear Elastic Wave Spectroscopy Methods

NASA Astrophysics Data System (ADS)

Meo, Michele; Polimeno, Umberto; Zumpano, Giuseppe

2008-05-01

Modern aerospace structures make increasing use of fibre reinforced plastic composites, due to their high specific mechanical properties. However, due to their brittleness, low velocity impact can cause delaminations beneath the surface, while the surface may appear to be undamaged upon visual inspection. Such damage is called barely visible impact damage (BVID). Such internal damages lead to significant reduction in local strengths and ultimately could lead to catastrophic failures. It is therefore important to detect and monitor damages in high loaded composite components to receive an early warning for a well timed maintenance of the aircraft. Non-linear ultrasonic spectroscopy methods are promising damage detection and material characterization tools. In this paper, two different non-linear elastic wave spectroscopy (NEWS) methods are presented: single mode nonlinear resonance ultrasound (NRUS) and nonlinear wave modulation technique (NWMS). The NEWS methods were applied to detect delamination damage due to low velocity impact (<12 J) on various composite plates. The results showed that the proposed methodology appear to be highly sensitive to the presence of damage with very promising future NDT and structural health monitoring applications.

Jeju ground water containing vanadium induced immune activation on splenocytes of low dose γ-rays-irradiated mice.

PubMed

Ha, Danbee; Joo, Haejin; Ahn, Ginnae; Kim, Min Ju; Bing, So Jin; An, Subin; Kim, Hyunki; Kang, Kyung-goo; Lim, Yoon-Kyu; Jee, Youngheun

2012-06-01

Vanadium, an essential micronutrient, has been implicated in controlling diabetes and carcinogenesis and in impeding reactive oxygen species (ROS) generation. γ-ray irradiation triggers DNA damage by inducing ROS production and causes diminution in radiosensitive immunocytes. In this study, we elucidate the immune activation capacities of Jeju water containing vanadium on immunosuppression caused by γ-ray irradiation, and identify its mechanism using various low doses of NaVO(3). We examined the intracellular ROS generation, DNA damage, cell proliferation, population of splenocytes, and cytokine/antibody profiles in irradiated mice drinking Jeju water for 180 days and in non-irradiated and in irradiated splenocytes both of which were treated with NaVO(3). Both Jeju water and 0.245 μM NaVO(3) attenuated the intracellular ROS generation and DNA damage in splenocytes against γ-ray irradiation. Splenocytes were significantly proliferated by the long-term intake of Jeju water and by 0.245 μM NaVO(3) treatment, and the expansion of B cells accounted for the increased number of splenocytes. Also, 0.245 μM NaVO(3) treatment showed the potency to amplify the production of IFN-γ and total IgG in irradiated splenocytes, which correlated with the expansion of B cells. Collectively, Jeju water containing vanadium possesses the immune activation property against damages caused by γ-irradiation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Dermatophytes activate skin keratinocytes via mitogen-activated protein kinase signaling and induce immune responses.

PubMed

Achterman, Rebecca R; Moyes, David L; Thavaraj, Selvam; Smith, Adam R; Blair, Kris M; White, Theodore C; Naglik, Julian R

2015-04-01

Dermatophytes cause superficial and cutaneous fungal infections in immunocompetent hosts and invasive disease in immunocompromised hosts. However, the host mechanisms that regulate innate immune responses against these fungi are largely unknown. Here, we utilized commercially available epidermal tissues and primary keratinocytes to assess (i) damage induction by anthropophilic, geophilic, and zoophilic dermatophyte strains and (ii) the keratinocyte signaling pathways, transcription factors, and proinflammatory responses induced by a representative dermatophyte, Trichophyton equinum. Initially, five dermatophyte species were tested for their ability to invade, cause tissue damage, and induce cytokines, with Microsporum gypseum inducing the greatest level of damage and cytokine release. Using T. equinum as a representative dermatophyte, we found that the mitogen-activated protein kinase (MAPK) pathways were predominantly affected, with increased levels of phospho-p38 and phospho-Jun N-terminal protein kinase (JNK) but decreased levels of phospho-extracellular signal-regulated kinases 1 and 2 (ERK1/2). Notably, the NF-κB and PI3K pathways were largely unaffected. T. equinum also significantly increased expression of the AP-1-associated transcription factor, c-Fos, and the MAPK regulatory phosphatase, MKP1. Importantly, the ability of T. equinum to invade, cause tissue damage, activate signaling and transcription factors, and induce proinflammatory responses correlated with germination, indicating that germination may be important for dermatophyte virulence and host immune activation. Copyright © 2015, Achterman et al.

Water Vapor Permeation in Plastics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keller, Paul E.; Kouzes, Richard T.

Polyvinyl toluene (PVT) and polystyrene (PS) (referred to as “plastic scintillator”) are used for gamma ray detectors. A significant decrease in radiation detection performance has been observed in some PVT-based gamma-ray detectors in systems in outdoor environments as they age. Recent studies have revealed that plastic scintillator can undergo an environmentally related material degradation that adversely affects gamma ray detection performance under certain conditions and histories. A significant decrease in sensitivity has been seen in some gamma-ray detectors in some systems as they age. The degradation of sensitivity of plastic scintillator over time is due to a variety of factors,more » and the term “aging” is used to encompass all factors. Some plastic scintillator samples show no aging effects (no significant change in sensitivity over more than 10 years), while others show severe aging (significant change in sensitivity in less than 5 years). Aging effects arise from weather (variations in heat and humidity), chemical exposure, mechanical stress, light exposure, and loss of volatile components. The damage produced by these various causes can be cumulative, causing observable damage to increase over time. Damage may be reversible up to some point, but becomes permanent under some conditions. The objective of this report is to document the phenomenon of permeability of plastic scintillator to water vapor and to derive the relationship between time, temperature, humidity and degree of water penetration in plastic. Several conclusions are documented about the properties of water permeability of plastic scintillator.« less

Myostatin as a Marker for Doxorubicin Induced Cardiac Damage.

PubMed

Kesik, Vural; Honca, Tevfik; Gulgun, Mustafa; Uysal, Bulent; Kurt, Yasemin Gulcan; Cayci, Tuncer; Babacan, Oguzhan; Gocgeldi, Ercan; Korkmazer, Nadir

2016-01-01

Doxorubicin (DXR) is an effective chemotherapeutic agent but causes severe cardiac failure over known doses. Thus, early detection and prevention of cardiac damage is important. Various markers have been tested for early detection of cardiac damage. Myostatin is a protein produced in skeletal muscle cells inhibits muscle differentiation and growth during myogenesis. We evaluated the role of myostatin as a marker for showing DXR induced cardiac damage and compared with well known cardiac markers like NT-proBNP, hs-TnT and CK in a rat model of chronic DXR cardiotoxicity. Myostatin, NT-proBNP, and hs-TnT but not CK rose significantly during DXR treatment. Myostatin can be used as an early marker of DXR induced cardiotoxicity. © 2016 by the Association of Clinical Scientists, Inc.

Advanced Booster Liquid Engine Combustion Stability

NASA Technical Reports Server (NTRS)

Tucker, Kevin; Gentz, Steve; Nettles, Mindy

2015-01-01

Combustion instability is a phenomenon in liquid rocket engines caused by complex coupling between the time-varying combustion processes and the fluid dynamics in the combustor. Consequences of the large pressure oscillations associated with combustion instability often cause significant hardware damage and can be catastrophic. The current combustion stability assessment tools are limited by the level of empiricism in many inputs and embedded models. This limited predictive capability creates significant uncertainty in stability assessments. This large uncertainty then increases hardware development costs due to heavy reliance on expensive and time-consuming testing.

Imidacloprid Causes DNA Damage in Fish: Clastogenesis as a Mechanism of Genotoxicity.

PubMed

Iturburu, Fernando G; Simoniello, María F; Medici, Sandra; Panzeri, Ana M; Menone, Mirta L

2018-06-01

Neonicotinoids are one of the most widely used insecticides in the world. DNA damage is considered an early biological effect which could lead to reproductive and carcinogenic effects. The present study aimed to evaluate DNA damage and bases oxidation as a mechanism of genotoxicity, on the freshwater fish Australoheros facetus acutely exposed to imidacloprid (IMI). The Comet assay with the nuclease ENDO III enzyme was performed for detecting pyrimidine bases oxidation using blood samples. Micronucleus and other nuclear abnormalities frequencies were also quantified. A significant increase of damage index at 100 and 1000 µg/L IMI was detected; while ENDO III score increased from 1 to 1000 µg/L IMI; varying both in a linear concentration-response manner. MN frequency increased in fish exposed to 1000 µg/L IMI. These results show that short-term exposures to environmentally relevant concentrations of IMI could affect the genetic integrity of fishes through oxidative damage.

Squirrel Damage to Pines

Treesearch

USDA Forest Service

1981-01-01

Flagging (dead branch tips) on jack pine and red pine may be caused by insects, diseases, or mechanical damage. In the Lake States, flagging is often the result of mechanical damage, sometimes girdling, caused when the cones are torn off by red squirrels.

Flood risk change in some European, African and Asian catchments

NASA Astrophysics Data System (ADS)

Kreibich, Heidi

2017-04-01

In light of the expected increase of flood risk in large parts of the world due to climate change and globally increasing exposure, efficient integrated flood risk management needs to be implemented. Societies learn from floods, and consequently improve their risk management. Such learning can occur through 'focusing events', i.e. events that provide a sudden, strong push for action. For example, the 1953 North Sea flood triggered the Delta Works in The Netherlands and the construction of the Thames Barrier. We show how societies have learnt from focusing events in river systems, by a semi-quantitative assessment of eight paired flood events around the world, i.e. consecutive floods that occurred in the same catchments, with the second flood causing significantly lower damage. We unravel the main mechanisms underlying these eight success stories of risk reduction. Across all case studies, we find that lower damage caused by the second event was mainly due to significant reductions in vulnerability. The role of changes in exposure is less apparent; positive and negative changes are reported. In some cases, significant investments in flood protection between the floods have played a large role in exposure and damage reduction. Reduction of vulnerability seems to be a key for better risk reduction via integrated flood risk management. Thus, we need to redouble efforts to improve our understanding of vulnerability.

Endometrial damage and apoptosis in rats induced by dichlorvos and ameliorating effect of antioxidant vitamins E and C.

PubMed

Oral, Baha; Guney, Mehmet; Demirin, Hilmi; Ozguner, Meltem; Giray, Seren Gülsen; Take, Gulnur; Mungan, Tamer; Altuntas, Irfan

2006-11-01

We aimed to investigate the effect of subchronic administration of dichlorvos (DDVP) on endometrium and to evaluate ameliorating effects of a combination of Vitamins E and C against DDVP toxicity in the rat. Three groups of rats were used in the experiment. The first group was treated with 4 mg/kg DDVP; the second group was treated with 4 mg/kg body weight DDVP plus Vitamins E and C (DDVP+Vit); the third group was given only corn oil (control). DDVP and DDVP+Vit groups were given DDVP by gavage 5 days a week for 4 weeks at a dose level of 4 mg/kg day by using corn oil as the vechicle. Vitamins E and C were injected at doses of 50 mg/kg i.m. and 20 mg/kg body weight i.p. Histopathological and immunohistochemical examinations for caspase-3 and caspase-9 were accomplished in the endometrium. The level of malondialdehyde (MDA) increased significantly in the DDVP group compared with the control group (p<0.05). MDA significantly decreased in the DDVP+Vit group compared with the DDVP group (p<0.05). Administration of Vitamins E and C along with DDVP significantly reduced the histopathological changes and the extent of apoptosis. In conclusion, subchronic DDVP administration caused endometrial damage and that treatment with a combination of Vitamins E and C reduced endometrial damage caused by DDVP.

Terrestrial ozone depletion due to a Milky Way gamma-ray burst

NASA Astrophysics Data System (ADS)

Thomas, Brian C.

Gamma-Ray Bursts (GRBs) are short, incredibly powerful astrophysical events which produce a flux of radiation detectable across the observable universe. A GRB within our own galaxy could cause major damage to the Earth's biosphere. Rate estimates suggest that at least one GRB has occurred within a dangerous range (about 2 kpc) in the last billion years. The gamma radiation from such a burst would quickly deplete much of the Earth's protective ozone layer, allowing an increase in solar UVB radiation reaching the surface. This radiation is harmful to life, causing sunburn and damaging DNA. In addition, NO 2 produced in the atmosphere would cause a decrease in visible sunlight reaching the surface and could cause global cooling. Nitric acid rain could stress portions of the biosphere, but the increased nitrate deposition could be helpful to land plants. We have used a two-dimensional atmospheric model to investigate the effects on the Earth's atmosphere of a GRB. We have simulated bursts delivering a range of fluences, at various latitudes, at the equinoxes and solstices, and at different times of day. We have computed DNA damage caused by increased solar UVB radiation, reduction in solar visible light due to NO 2 opacity; and deposition of nitrates through rainout of HNO 3 . For a "typical" burst in the last billion years, we find globally averaged ozone depletion up to 38%. Localized depletion reaches as much as 74%. Significant global depletion (at least 10%) persists up to about 7 years after the burst. Our results depend strongly on time of year and latitude over which the burst occurs. We find DNA damage of up to 16 times the normal annual global average, with greatest damage occurring at low to mid latitudes. We find reductions in visible sunlight of a few percent, primarily in the polar regions. Nitrate deposition similar to or slightly greater than that currently caused by lightning is also observed. We find support in our results for the hypothesis that the Late Ordovician mass extinction may have been initiated by a GRB and this connection is briefly discussed.

Anatomical causes of female infertility and their management.

PubMed

Abrao, Mauricio S; Muzii, Ludovico; Marana, Riccardo

2013-12-01

The main female anatomical causes of infertility include post-infectious tubal damage, endometriosis, and congenital/acquired uterine anomalies. Congenital (septate uterus) and acquired (myomas and synechiae) diseases of the uterus may lead to infertility, pregnancy loss, and other obstetric complications. Pelvic inflammatory disease represents the most common cause of tubal damage. Surgery still remains an important option for tubal factor infertility, with results in terms of reproductive outcome that compare favorably with those of in vitro fertilization. Endometriosis is a common gynecologic condition affecting women of reproductive age, which can cause pain and infertility. The cause of infertility associated with endometriosis remains elusive, suggesting a multifactorial mechanism involving immunologic, genetic, and environmental factors. Despite the high prevalence of endometriosis, the exact mechanisms of its pathogenesis are unknown. Specific combinations of medical, surgical, and psychological treatments can ameliorate the quality of life of women with endometriosis. In the majority of cases, surgical treatment of endometriosis has promoted significant increases in fertilization rates. There are obvious associations between endometriosis and the immune system, and future strategies to treat endometriosis might be based on immunologic concepts. © 2013.

Role of ROS and RNS Sources in Physiological and Pathological Conditions

PubMed Central

Victor, Victor Manuel

2016-01-01

There is significant evidence that, in living systems, free radicals and other reactive oxygen and nitrogen species play a double role, because they can cause oxidative damage and tissue dysfunction and serve as molecular signals activating stress responses that are beneficial to the organism. Mitochondria have been thought to both play a major role in tissue oxidative damage and dysfunction and provide protection against excessive tissue dysfunction through several mechanisms, including stimulation of opening of permeability transition pores. Until recently, the functional significance of ROS sources different from mitochondria has received lesser attention. However, the most recent data, besides confirming the mitochondrial role in tissue oxidative stress and protection, show interplay between mitochondria and other ROS cellular sources, so that activation of one can lead to activation of other sources. Thus, it is currently accepted that in various conditions all cellular sources of ROS provide significant contribution to processes that oxidatively damage tissues and assure their survival, through mechanisms such as autophagy and apoptosis. PMID:27478531

Possible GABAergic modulation in the protective effect of zolpidem in acute hypoxic stress-induced behavior alterations and oxidative damage.

PubMed

Kumar, Anil; Goyal, Richa

2008-03-01

Hypoxia is an environmental stressor that is known to elicit alterations in both the autonomic nervous system and endocrine functions. The free radical or oxidative stress theory holds that oxidative reactions are mainly underlying neurodegenerative disorders. In fact among complex metabolic reactions occurring during hypoxia, many could be related to the formation of oxygen derived free radicals, causing a wide spectrum of cell damage. In present study, we investigated possible involvement of GABAergic mechanism in the protective effect of zolpidem against acute hypoxia-induced behavioral modification and biochemical alterations in mice. Mice were subjected to acute hypoxic stress for a period of 2 h. Acute hypoxic stress for 2 h caused significant impairment in locomotor activity, anxiety-like behavior, and antinocioceptive effect in mice. Biochemical analysis revealed a significant increased malondialdehyde, nitrite concentrations and depleted reduced glutathione and catalase levels. Pretreatment with zolpidem (5 and 10 mg/kg, i.p.) significantly improved locomotor activity, anti-anxiety effect, reduced tail flick latency and attenuated oxidative damage (reduced malondialdehyde, nitrite concentration, and restoration of reduced glutathione and catalase levels) as compared to stressed control (hypoxia) (P < 0.05). Besides, protective effect of zolpidem (5 mg/kg) was blocked significantly by picrotoxin (1.0 mg/kg) or flumazenil (2 mg/kg) and potentiated by muscimol (0.05 mg/kg) in hypoxic animals (P < 0.05). These effects were significant as compared to zolpidem (5 mg/kg) per se (P < 0.05). Present study suggest that the possible involvement of GABAergic modulation in the protective effect of zolpidem against hypoxic stress.

Research Advances in the Screwworm Eradication Program over the Past 25 Years

USDA-ARS?s Scientific Manuscript database

Screwworms, Cochliomyia hominivorax (Coquerel) (Calliphoridae: Chrysomyinae), are devastating pests of warm blooded animals that cause significant economic damage to livestock. The successful campaign to eradicate screwworms from continental North America using the sterile insect technique, led by t...

CATALYTIC ENZYME-BASED METHODS FOR WATER TREATMENT AND WATER DISTRIBUTION SYSTEM DECONTAMINATION

EPA Science Inventory

Current chemistry-based decontaminants for chemical or biological warfare agents and related toxic materials are caustic and have the potential for causing material and environmental damage. In addition, most are bulk liquids that require significant logistics and storage capabil...

OVERVIEW OF LEACHING CHEMISTRY AND TESTING RESEARCH IN ORD/EPA

EPA Science Inventory

Various anthropogenic activities generate hazardous solid wastes that are affluent in heavy metals and organics, which can cause significant damage to the environment and human health. Heavy metals can exist in multiple oxidation states, and can undergo oxidation or reduction whe...

Discrimination and Cumulative Disease Damage Among African American Women With Systemic Lupus Erythematosus.

PubMed

Chae, David H; Drenkard, Cristina M; Lewis, Tené T; Lim, S Sam

2015-10-01

We examined associations between unfair treatment, attributions of unfair treatment to racial discrimination, and cumulative disease damage among African American women with systemic lupus erythematosus (SLE). We used multivariable regression models to examine SLE damage among 578 African American women in metropolitan Atlanta, Georgia, recruited to the Georgians Organized Against Lupus cohort. When we controlled for demographic, socioeconomic, and health-related covariates, reporting any unfair treatment was associated with greater SLE damage compared with reporting no unfair treatment (b = 0.55; 95% confidence interval = 0.14, 0.97). In general, unfair treatment attributed to nonracial factors was more strongly associated with SLE damage than was unfair treatment attributed to racial discrimination, although the difference was not statistically significant. Unfair treatment may contribute to worse disease outcomes among African American women with SLE. Unfair treatment attributed to nonracial causes may have a more pronounced negative effect on SLE damage. Future research may further examine possible differences in the effect of unfair treatment by attribution.

Leucocytes DNA damage in mice exposed to JS-118 by the comet assay.

PubMed

Zhang, Tao; Hu, Jiye; Zhang, Yuchao; Zhao, Qianfei; Ning, Jun

2011-09-01

JS-118 is an extensively used insecticide in China. The present study investigated the genotoxic effect of JS-118 on whole blood at 24, 48, 72 and 96 h by using alkaline comet assay. Male Kunming mice were given 6.25, 12.5, 25, 50 and 100 mg/kg BW of JS-118 intraperitoneally. A statistically significant increase in all comet parameters indicating DNA damage was observed at 24 h post-treatment (p < 0.05). A clear concentration-dependent increase of DNA damage was revealed as evident by the OTM (arbitrary units), tail length (µm) and tail DNA (%). From 48 h post-treatment, a gradual decrease in mean comet parameters was noted. By 96 h of post-treatment, the mean comet tail length reached control levels indicating repair of damaged DNA. This study on mice showed different DNA damage depending on the concentration of JS-118 and the period of treatment. The present study provided further information of the potential risk of the genetic damage caused by JS-118.

[Study on sperm damage caused by trichloroethylene in male rats].

PubMed

Wu, De-sheng; Yang, Lin-qing; Huang, Sui; Liu, Jian-jun; Xu, Xin-yun; Huang, Hai-yan; Gong, Chun-mei; Hu, Gong-hua; Liu, Qing-cheng; Yang, Xi-fei; Hong, Wen-xu; Zhou, Li; Huang, Xin-feng; Yuan, Jian-hui; Zhuang, Zhi-xiong

2013-11-01

To study in vitro sperm damage caused by trichloroethylene in male rats. Sperms of Sprague-Dawley (SD) rats were collected 4 hours after being contaminated by trichloroethylene of 0, 2, 4, 6, 8, and 10 mmol/L in vitro. Giemsa staining was performed to observe the morphological changes of sperms, and flow cytometer was used to detect the changes in mitochondrial membrane potential. The sperm motilities in 6, 8, and 10 mmol/L trichloroethylene groups decreased significantly compared with that in control group (P <0.01); the sperm aberration rates in 8 and 10 mmol/L trichloroethylene groups were significantly higher than that in control group (P<0.01). With the increase in exposure dose, the proportion of sperms with reduced mitochondrial membrane potential increased, and there were significant differences in sperm apoptosis rate between the 4, 6, 8, and 10 mmol/L trichloroethylene groups and control group (P<0.01). In vitro exposure to trichloroethylene can reduce sperm motility and increase the aberration rate and apoptosis rate of sperms in male SD rats.

Genomic Instability Associated with p53 Knockdown in the Generation of Huntington’s Disease Human Induced Pluripotent Stem Cells

PubMed Central

Tidball, Andrew M.; Neely, M. Diana; Chamberlin, Reed; Aboud, Asad A.; Kumar, Kevin K.; Han, Bingying; Bryan, Miles R.; Aschner, Michael; Ess, Kevin C.; Bowman, Aaron B.

2016-01-01

Alterations in DNA damage response and repair have been observed in Huntington’s disease (HD). We generated induced pluripotent stem cells (iPSC) from primary dermal fibroblasts of 5 patients with HD and 5 control subjects. A significant fraction of the HD iPSC lines had genomic abnormalities as assessed by karyotype analysis, while none of our control lines had detectable genomic abnormalities. We demonstrate a statistically significant increase in genomic instability in HD cells during reprogramming. We also report a significant association with repeat length and severity of this instability. Our karyotypically normal HD iPSCs also have elevated ATM-p53 signaling as shown by elevated levels of phosphorylated p53 and H2AX, indicating either elevated DNA damage or hypersensitive DNA damage signaling in HD iPSCs. Thus, increased DNA damage responses in the HD genotype is coincidental with the observed chromosomal aberrations. We conclude that the disease causing mutation in HD increases the propensity of chromosomal instability relative to control fibroblasts specifically during reprogramming to a pluripotent state by a commonly used episomal-based method that includes p53 knockdown. PMID:26982737

Shoot Development and Extension of Quercus serrata Saplings in Response to Insect Damage and Nutrient Conditions

PubMed Central

MIZUMACHI, ERI; MORI, AKIRA; OSAWA, NAOYA; AKIYAMA, REIKO; TOKUCHI, NAOKO

2006-01-01

• Background and Aims Plants have the ability to compensate for damage caused by herbivores. This is important to plant growth, because a plant cannot always avoid damage, even if it has developed defence mechanisms against herbivores. In previous work, we elucidated the herbivory-induced compensatory response of Quercus (at both the individual shoot and whole sapling levels) in both low- and high-nutrient conditions throughout one growing season. In this study, we determine how the compensatory growth of Quercus serrata saplings is achieved at different nutrient levels. • Methods Quercus serrata saplings were grown under controlled conditions. Length, number of leaves and percentage of leaf area lost on all extension units (EUs) were measured. • Key Results Both the probability of flushing and the length of subsequent EUs significantly increased with an increase in the length of the parent EU. The probability of flushing increased with an increase in leaf damage of the parent EU, but the length of subsequent EUs decreased. This indicates that EU growth is fundamentally regulated at the individual EU level. The probabilities of a second and third flush were significantly higher in plants in high-nutrient soil than those in low-nutrient soil. The subsequent EUs of damaged saplings were also significantly longer at high-nutrient conditions. • Conclusions An increase in the probability of flushes in response to herbivore damage is important for damaged saplings to produce new EUs; further, shortening the length of EUs helps to effectively reproduce foliage lost by herbivory. The probability of flushing also varied according to soil nutrient levels, suggesting that the compensatory growth of individual EUs in response to local damage levels is affected by the nutrients available to the whole sapling. PMID:16709576

Oxidative damage of DNA in subjects occupationally exposed to lead.

PubMed

Pawlas, Natalia; Olewińska, Elżbieta; Markiewicz-Górka, Iwona; Kozłowska, Agnieszka; Januszewska, Lidia; Lundh, Thomas; Januszewska, Ewa; Pawlas, Krystyna

2017-09-01

Exposure to lead (Pb) in environmental and occupational settings continues to be a serious public health problem and may pose an elevated risk of genetic damage. The aim of this study was to assess the level of oxidative stress and DNA damage in subjects occupationally exposed to lead. We studied a population of 78 male workers exposed to lead in a lead and zinc smelter and battery recycling plant and 38 men from a control group. Blood lead levels were detected by graphite furnace atomic absorption spectrophotometry and plasma lead levels by inductively coupled plasma-mass spectrometry. The following assays were performed to assess the DNA damage and oxidative stress: comet assay, determination of 8-hydroxy-2'-deoxyguanosine (8-OHdG), lipid peroxidation and total antioxidant status (TAS). The mean concentration of lead in the blood of the exposed group was 392 ± 103 μg/L and was significantly higher than in the control group (30.3 ± 29.4 μg/L, p < 0.0001). Oxidative DNA damages measured by comet assay showed no significant differences between populations. The concentration of 8-OHdG was about twice as high as in the control group. We found a significant positive correlation between the level of biomarkers of lead exposure [lead in blood, lead in plasma, zinc protoporphyrin (ZPP)] and urine concentration of 8-OHdG. The level of oxidative damage of DNA was positively correlated with the level of lipid peroxidation (TBARS) and negatively with total anti-oxidative status (TAS). Our study suggests that occupational exposure causes an increase in oxidative damage to DNA, even in subjects with relatively short length of service (average length of about 10 years). 8-OHdG concentration in the urine proved to be a sensitive and non-invasive marker of lead induced genotoxic damage.

Indoor Air Problems and Hoarseness in Children.

PubMed

Kallvik, Emma; Putus, Tuula; Simberg, Susanna

2016-01-01

A well-functioning voice is becoming increasingly important because voice-demanding professions are increasing. The largest proportion of voice disorders is caused by factors in the environment. Moisture damage is common and can initiate microbial growth and/or diffusion of chemicals from building materials. Indoor air problems due to moisture damage are associated with a number of health symptoms, for example, rhinitis, cough, and asthma symptoms. The purpose of this study was to investigate if children attending a day care center, preschool, or school with indoor air problems due to moisture damage were hoarse more often than the children in a control group. Information was collected through electronic and paper questionnaires from the parents of 6- to 9-year-old children (n = 1857) attending 57 different day care centers, preschools, or schools with or without indoor air problems due to moisture damage. The results showed a significant correlation between the degree of indoor air problem due to moisture damage and the frequency of hoarseness. Significant predictors for the child being hoarse every week or more often were dry cough, phlegm cough, and nasal congestion. The results indicate that these symptoms and exposure to indoor air problems due to moisture damage should be included in voice anamnesis. Furthermore, efforts should be made to remediate indoor air problems due to moisture damage and to treat health symptoms. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Effects of Diode Laser Debonding of Ceramic Brackets on Enamel Surface and Pulpal Temperature.

PubMed

Yassaei, Soghra; Soleimanian, Azadeh; Nik, Zahra Ebrahimi

2015-04-01

Debonding of ceramic brackets due to their high bond strength and low fracture toughness is one of the most challenging complications of orthodontic clinicians. Application of lasers might be effective in the debonding of ceramic brackets as they reduce bond strength of resins and, therefore, can eliminate the risk of enamel damage. However, the thermal effects of laser radiation on dental tissue can cause undesirable results. The aim of this study is to evaluate the enamel surface characteristics and pulpal temperature changes of teeth after debonding of ceramic brackets with or without laser light. Thirty polycrystalline brackets were bonded to 30 intact extracted premolars, and later debonded conventionally or through a diode laser (2.5 W, 980 nm). The laser was applied for 10 seconds with sweeping movement. After debonding, the adhesive remnant index (ARI), the lengths and frequency of enamel cracks were compared among the groups. The increase in intrapulpal temperature was also measured. The collected data were analyzed by Chi-squared test and paired t-test using Statistical Package for Social Sciences (SPSS) software. There was no case of enamel fracture in none of the groups. Laser debonding caused a significant decrease in the frequency and lengths of enamel cracks, compared to conventional debonding. In laser debonding group, the increase in intrapulpal temperature (1.46°C) was significantly below the benchmark of 5.5°C for all the specimens. No significant difference was observed in ARI scores among the groups. Laser-assisted debonding of ceramic brackets could reduce the risk of enamel damage, without causing thermal damage to the pulp. However, some increases in the length and frequency of enamel cracks should be expected with all debonding methods.

Chronic subhepatotoxic exposure to arsenic enhances hepatic injury caused by high fat diet in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tan, Min; Schmidt, Robin H.; Beier, Juliane I.

Arsenic is a ubiquitous contaminant in drinking water. Whereas arsenic can be directly hepatotoxic, the concentrations/doses required are generally higher than present in the US water supply. However, physiological/biochemical changes that are alone pathologically inert can enhance the hepatotoxic response to a subsequent stimulus. Such a '2-hit' paradigm is best exemplified in chronic fatty liver diseases. Here, the hypothesis that low arsenic exposure sensitizes liver to hepatotoxicity in a mouse model of non-alcoholic fatty liver disease was tested. Accordingly, male C57Bl/6J mice were exposed to low fat diet (LFD; 13% calories as fat) or high fat diet (HFD; 42% caloriesmore » as fat) and tap water or arsenic (4.9 ppm as sodium arsenite) for ten weeks. Biochemical and histologic indices of liver damage were determined. High fat diet ({+-} arsenic) significantly increased body weight gain in mice compared with low-fat controls. HFD significantly increased liver to body weight ratios; this variable was unaffected by arsenic exposure. HFD caused steatohepatitis, as indicated by histological assessment and by increases in plasma ALT and AST. Although arsenic exposure had no effect on indices of liver damage in LFD-fed animals, it significantly increased the liver damage caused by HFD. This effect of arsenic correlated with enhanced inflammation and fibrin extracellular matrix (ECM) deposition. These data indicate that subhepatotoxic arsenic exposure enhances the toxicity of HFD. These results also suggest that arsenic exposure might be a risk factor for the development of fatty liver disease in human populations. -- Highlights: Black-Right-Pointing-Pointer Characterizes a mouse model of arsenic enhanced NAFLD. Black-Right-Pointing-Pointer Arsenic synergistically enhances experimental fatty liver disease at concentrations that cause no overt hepatotoxicity alone. Black-Right-Pointing-Pointer This effect is associated with increased inflammation.« less

Therapeutic effect of magnesium sulphate on carbon monoxide toxicity-mediated brain lipid peroxidation.

PubMed

Yavuz, Y; Mollaoglu, H; Yürümez, Y; Ucok, K; Duran, L; Tünay, K; Akgün, L

2013-02-01

Carbon monoxide (CO) toxicity primarily results from cellular hypoxia caused by impedance of oxygen delivery. Studies show that CO may cause brain lipid peroxidation and leukocyte-mediated inflammatory changes in the brain. The aim of this study was to investigate whether magnesium sulphate could prevent or diminish brain lipid peroxidation caused by carbon monoxide toxicity in rats. Fourty rats were divided into five groups of 8 rats each. Group l was not received any agent during the experiment. Group 2 was inhaled CO gas followed by intraperitoneally normal saline 30 minutes (min) later. Group 3 was inhaled CO gas followed by 100 mg/kg magnesium sulphate intraperitoneally 30 min later. Group 2 and Group 3 rats was undergone laparotomy and craniotomy while still under anesthesia at 6 hour, and tissue sample was obtained from the cerebrum. Group 4 was inhaled CO gas followed by intraperitoneally normal saline 30 min later. Group 5 was inhaled CO gas followed by 100 mg/kg magnesium sulphate intraperitoneally 30 min later. Group 4 and Group 5 rats was undergone laparotomy and craniotomy while still under anesthesia at 24 hour, and tissue sample was obtained from the cerebrum. Nitric oxide levels were no significantly different between all groups. Malonyldialdehyde levels increased in intoxication group (group 2) and decreased in treatment group (group 3). Activities of superoxide dismutase decreased in intoxication group (group 2) and increased in treatment group (group 3). Activities of catalase increased in intoxication group (group 2) and decreased in treatment group (group 3). Activities of glutathione peroxidase (GSH-Px) decreased in intoxication group (group 4) and increased in treatment group (group 5). CO poisoning caused significant damage, detected within the first 6 hours. Due to antioxidant enzymes, especially GSH-Px activity reaching the top level within 24th hours, significant oxidative damage was not observed. The protective effect against oxidative damage of magnesium sulfate has been identified within the first 6 hours.

Protective effect of metronidazole on uncoupling mitochondrial oxidative phosphorylation induced by NSAID: a new mechanism.

PubMed

Leite, A Z; Sipahi, A M; Damião, A O; Coelho, A M; Garcez, A T; Machado, M C; Buchpiguel, C A; Lopasso, F P; Lordello, M L; Agostinho, C L; Laudanna, A A

2001-02-01

The pathogenesis of non-steroidal anti-inflammatory drug (NSAID) enteropathy is complex. It involves uncoupling of mitochondrial oxidative phosphorylation which alters the intercellular junction and increases intestinal permeability with consequent intestinal damage. Metronidazole diminishes the inflammation induced by indomethacin but the mechanisms remain speculative. A direct effect on luminal bacteria has traditionally been thought to account for the protective effect of metronidazole. However, a protective effect of metronidazole on mitochondrial oxidative phosphorylation has never been tested. To assess the protective effect of metronidazole on mitochondrial uncoupling induced by indomethacin and also on the increased intestinal permeability and macroscopic damage. The protective effect of metronidazole was evaluated in rats given indomethacin; a macroscopic score was devised to quantify intestinal lesions, and intestinal permeability was measured by means of (51)Cr-ethylenediaminetetraacetic acid. The protective effect of metronidazole against mitochondrial uncoupling induced by indomethacin was assessed using isolated coupled rat liver mitochondria obtained from rats pretreated with metronidazole or saline. Metronidazole significantly reduced the macroscopic intestinal damage and increase in intestinal permeability induced by indomethacin; furthermore, at the mitochondrial level, it significantly reduced the increase in oxygen consumption in state 4 induced by indomethacin and caused less reduction of the respiratory control rate. Our study confirmed the beneficial effects of metronidazole on intestinal damage and intestinal permeability, and demonstrated, for the first time, a direct protective effect of metronidazole on uncoupling of mitochondrial oxidative phosphorylation caused by NSAIDs.

Protective effect of alpha glucosyl hesperidin (G-hesperidin) on chronic vanadium induced testicular toxicity and sperm nuclear DNA damage in male Sprague Dawley rats.

PubMed

Vijaya Bharathi, B; Jaya Prakash, G; Krishna, K M; Ravi Krishna, C H; Sivanarayana, T; Madan, K; Rama Raju, G A; Annapurna, A

2015-06-01

The study was conducted to evaluate the vanadium-induced testicular toxicity and its effect on sperm parameters, sperm nuclear DNA damage and histological alterations in Sprague Dawley rats and to assess the protective effect of G-hesperidin against this damage. Treatment of rats with vanadium at a dose of 1 mg kg bw(-1) for 90 days resulted in significant reduction in serum testosterone levels, sperm count and motility. Further, a parallel increase in abnormal sperm morphology and adverse histopathological changes in testis was also associated with vanadium administration when compared to normal control. Moreover, sperm chromatin dispersion assay revealed that vanadium induces sperm nuclear DNA fragmentation. A marked increase in testicular malondialdehyde levels and decreased activity of antioxidant enzymes such as superoxide dismutase and catalase indicates vanadium-induced oxidative stress. Co-administration of G-hesperidin at a dose of 25 and 50 mg kg bw(-1) significantly attenuated the sperm parameters and histological changes by restoring the antioxidant levels in rat testis. These results suggested that vanadium exposure caused reduced bioavailability of androgens to the tissue and increased free radical formation, thereby causing structural and functional changes in spermatozoa. G-hesperidin exhibited antioxidant effect by protecting the rat testis against vanadium-induced oxidative damage, further ensures antioxidant potential of bioflavonoids. © 2014 Blackwell Verlag GmbH.

Gold nanoparticle induced vasculature damage in radiotherapy: Comparing protons, megavoltage photons, and kilovoltage photons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Yuting, E-mail: yutingl188@gmail.com; Paganetti, Harald; Schuemann, Jan

2015-10-15

Purpose: The purpose of this work is to investigate the radiosensitizing effect of gold nanoparticle (GNP) induced vasculature damage for proton, megavoltage (MV) photon, and kilovoltage (kV) photon irradiation. Methods: Monte Carlo simulations were carried out using tool for particle simulation (TOPAS) to obtain the spatial dose distribution in close proximity up to 20 μm from the GNPs. The spatial dose distribution from GNPs was used as an input to calculate the dose deposited to the blood vessels. GNP induced vasculature damage was evaluated for three particle sources (a clinical spread out Bragg peak proton beam, a 6 MV photonmore » beam, and two kV photon beams). For each particle source, various depths in tissue, GNP sizes (2, 10, and 20 nm diameter), and vessel diameters (8, 14, and 20 μm) were investigated. Two GNP distributions in lumen were considered, either homogeneously distributed in the vessel or attached to the inner wall of the vessel. Doses of 30 Gy and 2 Gy were considered, representing typical in vivo enhancement studies and conventional clinical fractionation, respectively. Results: These simulations showed that for 20 Au-mg/g GNP blood concentration homogeneously distributed in the vessel, the additional dose at the inner vascular wall encircling the lumen was 43% of the prescribed dose at the depth of treatment for the 250 kVp photon source, 1% for the 6 MV photon source, and 0.1% for the proton beam. For kV photons, GNPs caused 15% more dose in the vascular wall for 150 kVp source than for 250 kVp. For 6 MV photons, GNPs caused 0.2% more dose in the vascular wall at 20 cm depth in water as compared to at depth of maximum dose (Dmax). For proton therapy, GNPs caused the same dose in the vascular wall for all depths across the spread out Bragg peak with 12.7 cm range and 7 cm modulation. For the same weight of GNPs in the vessel, 2 nm diameter GNPs caused three times more damage to the vessel than 20 nm diameter GNPs. When the GNPs were attached to the inner vascular wall, the damage to the inner vascular wall can be up to 207% of the prescribed dose for the 250 kVp photon source, 4% for the 6 MV photon source, and 2% for the proton beam. Even though the average dose increase from the proton beam and MV photon beam was not large, there were high dose spikes that elevate the local dose of the parts of the blood vessel to be higher than 15 Gy even for 2 Gy prescribed dose, especially when the GNPs can be actively targeted to the endothelial cells. Conclusions: GNPs can potentially be used to enhance radiation therapy by causing vasculature damage through high dose spikes caused by the addition of GNPs especially for hypofractionated treatment. If GNPs are designed to actively accumulate at the tumor vasculature walls, vasculature damage can be increased significantly. The largest enhancement is seen using kilovoltage photons due to the photoelectric effect. Although no significant average dose enhancement was observed for the whole vasculature structure for both MV photons and protons, they can cause high local dose escalation (>15 Gy) to areas of the blood vessel that can potentially contribute to the disruption of the functionality of the blood vessels in the tumor.« less

Gold nanoparticle induced vasculature damage in radiotherapy: Comparing protons, megavoltage photons, and kilovoltage photons.

PubMed

Lin, Yuting; Paganetti, Harald; McMahon, Stephen J; Schuemann, Jan

2015-10-01

The purpose of this work is to investigate the radiosensitizing effect of gold nanoparticle (GNP) induced vasculature damage for proton, megavoltage (MV) photon, and kilovoltage (kV) photon irradiation. Monte Carlo simulations were carried out using tool for particle simulation (TOPAS) to obtain the spatial dose distribution in close proximity up to 20 μm from the GNPs. The spatial dose distribution from GNPs was used as an input to calculate the dose deposited to the blood vessels. GNP induced vasculature damage was evaluated for three particle sources (a clinical spread out Bragg peak proton beam, a 6 MV photon beam, and two kV photon beams). For each particle source, various depths in tissue, GNP sizes (2, 10, and 20 nm diameter), and vessel diameters (8, 14, and 20 μm) were investigated. Two GNP distributions in lumen were considered, either homogeneously distributed in the vessel or attached to the inner wall of the vessel. Doses of 30 Gy and 2 Gy were considered, representing typical in vivo enhancement studies and conventional clinical fractionation, respectively. These simulations showed that for 20 Au-mg/g GNP blood concentration homogeneously distributed in the vessel, the additional dose at the inner vascular wall encircling the lumen was 43% of the prescribed dose at the depth of treatment for the 250 kVp photon source, 1% for the 6 MV photon source, and 0.1% for the proton beam. For kV photons, GNPs caused 15% more dose in the vascular wall for 150 kVp source than for 250 kVp. For 6 MV photons, GNPs caused 0.2% more dose in the vascular wall at 20 cm depth in water as compared to at depth of maximum dose (Dmax). For proton therapy, GNPs caused the same dose in the vascular wall for all depths across the spread out Bragg peak with 12.7 cm range and 7 cm modulation. For the same weight of GNPs in the vessel, 2 nm diameter GNPs caused three times more damage to the vessel than 20 nm diameter GNPs. When the GNPs were attached to the inner vascular wall, the damage to the inner vascular wall can be up to 207% of the prescribed dose for the 250 kVp photon source, 4% for the 6 MV photon source, and 2% for the proton beam. Even though the average dose increase from the proton beam and MV photon beam was not large, there were high dose spikes that elevate the local dose of the parts of the blood vessel to be higher than 15 Gy even for 2 Gy prescribed dose, especially when the GNPs can be actively targeted to the endothelial cells. GNPs can potentially be used to enhance radiation therapy by causing vasculature damage through high dose spikes caused by the addition of GNPs especially for hypofractionated treatment. If GNPs are designed to actively accumulate at the tumor vasculature walls, vasculature damage can be increased significantly. The largest enhancement is seen using kilovoltage photons due to the photoelectric effect. Although no significant average dose enhancement was observed for the whole vasculature structure for both MV photons and protons, they can cause high local dose escalation (>15 Gy) to areas of the blood vessel that can potentially contribute to the disruption of the functionality of the blood vessels in the tumor.

Gold nanoparticle induced vasculature damage in radiotherapy: Comparing protons, megavoltage photons, and kilovoltage photons

PubMed Central

Lin, Yuting; Paganetti, Harald; McMahon, Stephen J.; Schuemann, Jan

2015-01-01

Purpose: The purpose of this work is to investigate the radiosensitizing effect of gold nanoparticle (GNP) induced vasculature damage for proton, megavoltage (MV) photon, and kilovoltage (kV) photon irradiation. Methods: Monte Carlo simulations were carried out using tool for particle simulation (TOPAS) to obtain the spatial dose distribution in close proximity up to 20 μm from the GNPs. The spatial dose distribution from GNPs was used as an input to calculate the dose deposited to the blood vessels. GNP induced vasculature damage was evaluated for three particle sources (a clinical spread out Bragg peak proton beam, a 6 MV photon beam, and two kV photon beams). For each particle source, various depths in tissue, GNP sizes (2, 10, and 20 nm diameter), and vessel diameters (8, 14, and 20 μm) were investigated. Two GNP distributions in lumen were considered, either homogeneously distributed in the vessel or attached to the inner wall of the vessel. Doses of 30 Gy and 2 Gy were considered, representing typical in vivo enhancement studies and conventional clinical fractionation, respectively. Results: These simulations showed that for 20 Au-mg/g GNP blood concentration homogeneously distributed in the vessel, the additional dose at the inner vascular wall encircling the lumen was 43% of the prescribed dose at the depth of treatment for the 250 kVp photon source, 1% for the 6 MV photon source, and 0.1% for the proton beam. For kV photons, GNPs caused 15% more dose in the vascular wall for 150 kVp source than for 250 kVp. For 6 MV photons, GNPs caused 0.2% more dose in the vascular wall at 20 cm depth in water as compared to at depth of maximum dose (Dmax). For proton therapy, GNPs caused the same dose in the vascular wall for all depths across the spread out Bragg peak with 12.7 cm range and 7 cm modulation. For the same weight of GNPs in the vessel, 2 nm diameter GNPs caused three times more damage to the vessel than 20 nm diameter GNPs. When the GNPs were attached to the inner vascular wall, the damage to the inner vascular wall can be up to 207% of the prescribed dose for the 250 kVp photon source, 4% for the 6 MV photon source, and 2% for the proton beam. Even though the average dose increase from the proton beam and MV photon beam was not large, there were high dose spikes that elevate the local dose of the parts of the blood vessel to be higher than 15 Gy even for 2 Gy prescribed dose, especially when the GNPs can be actively targeted to the endothelial cells. Conclusions: GNPs can potentially be used to enhance radiation therapy by causing vasculature damage through high dose spikes caused by the addition of GNPs especially for hypofractionated treatment. If GNPs are designed to actively accumulate at the tumor vasculature walls, vasculature damage can be increased significantly. The largest enhancement is seen using kilovoltage photons due to the photoelectric effect. Although no significant average dose enhancement was observed for the whole vasculature structure for both MV photons and protons, they can cause high local dose escalation (>15 Gy) to areas of the blood vessel that can potentially contribute to the disruption of the functionality of the blood vessels in the tumor. PMID:26429263

Does prolonged radiofrequency radiation emitted from Wi-Fi devices induce DNA damage in various tissues of rats?

PubMed

Akdag, Mehmet Zulkuf; Dasdag, Suleyman; Canturk, Fazile; Karabulut, Derya; Caner, Yusuf; Adalier, Nur

2016-09-01

Wireless internet (Wi-Fi) providers have become essential in our daily lives, as wireless technology is evolving at a dizzying pace. Although there are different frequency generators, one of the most commonly used Wi-Fi devices are 2.4GHz frequency generators. These devices are heavily used in all areas of life but the effect of radiofrequency (RF) radiation emission on users is generally ignored. Yet, an increasing share of the public expresses concern on this issue. Therefore, this study intends to respond to the growing public concern. The purpose of this study is to reveal whether long term exposure of 2.4GHz frequency RF radiation will cause DNA damage of different tissues such as brain, kidney, liver, and skin tissue and testicular tissues of rats. The study was conducted on 16 adult male Wistar-Albino rats. The rats in the experimental group (n=8) were exposed to 2.4GHz frequency radiation for over a year. The rats in the sham control group (n=8) were subjected to the same experimental conditions except the Wi-Fi generator was turned off. After the exposure period was complete the possible DNA damage on the rat's brain, liver, kidney, skin, and testicular tissues was detected through the single cell gel electrophoresis assay (comet) method. The amount of DNA damage was measured as percentage tail DNA value. Based on the DNA damage results determined by the single cell gel electrophoresis (Comet) method, it was found that the% tail DNA values of the brain, kidney, liver, and skin tissues of the rats in the experimental group increased more than those in the control group. The increase of the DNA damage in all tissues was not significant (p>0.05). However the increase of the DNA damage in rat testes tissue was significant (p<0.01). In conclusion, long-term exposure to 2.4GHz RF radiation (Wi-Fi) does not cause DNA damage of the organs investigated in this study except testes. The results of this study indicated that testes are more sensitive organ to RF radiation. Copyright © 2016 Elsevier B.V. All rights reserved.

Mechanisms, prevention and clinical implications of nonsteroidal anti-inflammatory drug-enteropathy

PubMed Central

Wallace, John L

2013-01-01

This article reviews the latest developments in understanding the pathogenesis, detection and treatment of small intestinal damage and bleeding caused by nonsteroidal anti-inflammatory drugs (NSAIDs). With improvements in the detection of NSAID-induced damage in the small intestine, it is now clear that this injury and the associated bleeding occurs more frequently than that occurring in the stomach and duodenum, and can also be regarded as more dangerous. However, there are no proven-effective therapies for NSAID-enteropathy, and detection remains a challenge, particularly because of the poor correlation between tissue injury and symptoms. Moreover, recent studies suggest that commonly used drugs for protecting the upper gastrointestinal tract (i.e., proton pump inhibitors) can significantly worsen NSAID-induced damage in the small intestine. The pathogenesis of NSAID-enteropathy is complex, but studies in animal models are shedding light on the key factors that contribute to ulceration and bleeding, and are providing clues to the development of effective therapies and prevention strategies. Novel NSAIDs that do not cause small intestinal damage in animal models offer hope for a solution to this serious adverse effect of one of the most widely used classes of drugs. PMID:23569332

Muscle enzyme release does not predict muscle function impairment after triathlon.

PubMed

Margaritis, I; Tessier, F; Verdera, F; Bermon, S; Marconnet, P

1999-06-01

We sought to determine the effects of a long distance triathlon (4 km swim, 120 km bike-ride, and 30 km run) on the four-day kinetics of the biochemical markers of muscle damage, and whether they were quantitatively linked with muscle function impairment and soreness. Data were collected from 2 days before until 4 days after the completion of the race. Twelve triathletes performed the triathlon and five did not. Maximal voluntary contraction (MVC), muscle soreness (DOMS) and total serum CK, CK-MB, LDH, AST and ALT activities were assessed. Significant changes after triathlon completion were found for all muscle damage indirect markers over time (p < 0.0001). MVC of the knee extensor and flexor muscles decreased over time (p < 0.05). There is disparity in the time point at which peak values where reached for DOMS, MVC and enzyme leakage. There is no correlation between serum enzyme leakage, DOMS and MVC impairment which occur after triathlon. Long distance triathlon race caused muscle damage, but extent, as well as muscle recovery cannot be evaluated by the magnitude of changes in serum enzyme activities. Muscle enzyme release cannot be used to predict the magnitude of the muscle function impairment caused by muscle damage.

Low dose radiation damage effects in silicon strip detectors

NASA Astrophysics Data System (ADS)

Wiącek, P.; Dąbrowski, W.

2016-11-01

The radiation damage effects in silicon segmented detectors caused by X-rays have become recently an important research topic driven mainly by development of new detectors for applications at the European X-ray Free Electron Laser (E-XFEL). However, radiation damage in silicon strip is observed not only after extreme doses up to 1 GGy expected at E-XFEL, but also at doses in the range of tens of Gy, to which the detectors in laboratory instruments like X-ray diffractometers or X-ray spectrometers can be exposed. In this paper we report on investigation of radiation damage effects in a custom developed silicon strip detector used in laboratory diffractometers equipped with X-ray tubes. Our results show that significant degradation of detector performance occurs at low doses, well below 200 Gy, which can be reached during normal operation of laboratory instruments. Degradation of the detector energy resolution can be explained by increasing leakage current and increasing interstrip capacitance of the sensor. Another observed effect caused by accumulation of charge trapped in the surface oxide layer is change of charge division between adjacent strips. In addition, we have observed unexpected anomalies in the annealing process.

Seasonal Abundance and Suppression of Fruit-Piercing Moth Eudocima phalonia (L.) in a Citrus Orchard in Sarawak

PubMed Central

Leong, Stephen Chan Teck; Kueh, Roland Jui Heng

2011-01-01

Seasonal population of the fruit-piercing moths Eudocima spp. was monitored throughout the citrus growing seasons in a citrus orchard and in site adjacent to secondary forest from July 2007 to June 2009. The moth was detected practically throughout the year with activity lowest during the wet months (September-February) when fruits are still available and while highest during the dry months (May-June) which also coincided with the main fruiting season. The effects of an nC24 horticultural mineral oil (HMO) on the citrus fruit damage caused by fruit-piecing moths was also determined. The percent fruit damage was significantly lowest (P≤0.05) in HMO-treated plots (8.4), followed by Dimethoate-treated plots (11.6) and untreated plots (22.5). However, there was no significant difference between HMO and Dimethoate treated plots indicating HMO is effective in reducing percent fruit damage. PMID:22203789

The insecticide buprofezin induces morphological transformation and kinetochore-positive micronuclei in cultured Syrian hamster embryo cells in the absence of detectable DNA damage.

PubMed

Herrera, L A; Ostrosky-Wegman, P; Schiffmann, D; Chen, Q Y; Ziegler-Skylakakis, K; Andrae, U

1993-11-01

The insecticide buprofezin was examined for its genotoxicity in cultured Syrian hamster embryo cells in order to better understand the mechanisms underlying the genotoxicity of the compound in mammalian cells. Exposure to buprofezin concentrations of 12.5-100 microM did not significantly affect the colony-forming ability of the cells, but did result in increased frequencies of morphologically transformed colonies. Treatment with buprofezin did not cause a detectable induction of DNA repair synthesis, an indicator of DNA damage, but significantly increased the frequency of micronuclei. Immunostaining of the cells with antikinetochore antibody (CREST antibody) showed that essentially all of the buprofezin-induced micronuclei were kinetochore-positive. The results suggest that morphological transformation of Syrian hamster embryo cells by buprofezin results from an interaction of the compound or a metabolite of it with the mitotic apparatus rather than from DNA damage.

Wooden beverage cases cause little damage to bottle caps

Treesearch

R. Bruce Anderson; William C. Miller

1973-01-01

Wooden beverage cases cause little damage to aluminum resealable caps during distribution. A study at bottling plants and distribution warehouses showed that an average of 1 bottle out of 4,000 has cap damage. Most of the damage was attributed to handling at the warehouse and in transit. Some recommendations are given for improvement of wooden beverage cases to prevent...

True memory, false memory, and subjective recollection deficits after focal parietal lobe lesions.

PubMed

Drowos, David B; Berryhill, Marian; André, Jessica M; Olson, Ingrid R

2010-07-01

There is mounting evidence that the posterior parietal cortex (PPC) plays an important role in episodic memory. We previously found that patients with PPC damage exhibit retrieval-related episodic memory deficits. Here we assess whether parietal lobe damage affects episodic memory on a different task: the Deese-Roediger-McDermott (DRM) false-memory paradigm. Two patients with bilateral PPC damage and a group of matched controls were tested. In Experiment 1, the task was to remember words; in Experiment 2 the task was to remember pictures of common objects. Prior studies have shown that normal participants have high levels of false memory to words, low levels to pictures. The patients exhibited significantly lower levels of false memory to words. One patient showed significantly elevated levels of false memory to pictures. The patients' false memories were accompanied by reduced levels of recollection, as tested by a Remember/Know procedure. PPC damage causes decreased levels of false memories and an abnormal Remember/Know profile. Their false memory rate is similar to the rate exhibited by patients with medial temporal lobe damage. These results support the view that portions of the PPC play a critical role in objective and subjective aspects of recollection.

Navy Safety Center data on the effects of fire protection systems on electrical equipment

NASA Astrophysics Data System (ADS)

Levine, Robert S.

1991-04-01

Records of the Navy Safety Center, Norfolk, VA were reviewed to find data relevant to inadvertant operation of installed fire extinguishing systems in civilian nuclear power plants. Navy data show the incidence of collateral fire or other damage by fresh water on operating electrical equipment in submarines and in shore facilities is about the same as the civilian experience, about 30 percent. Aboard surface ships, however, the collateral damage incidence in much lower, about 15 percent. With sea water, the collateral damage incidence is at least 75 percent. It is concluded that the fire extinguisher water has to be contaminated, as by rust in sprinkler systems or deposited salt spray, for most collateral damage to occur. Reasons for inadvertant operation (or advertant operation) of firex systems at shore facilities, submarines, and surface ships resemble those for nuclear power plants. Mechanical or electrical failures lead the list, followed by mishaps during maintenance. Detector and alarm system failures are significant problems at Navy shore facilities, and significant at nuclear power plants. Fixed halon and CO2 systems in shore facilities cause no collateral damage. Lists of individual Navy incidents with water and with halon and carbon dioxide are included as appendices.

Investigation of amorphization energies for heavy ion implants into silicon carbide at depths far beyond the projected ranges

NASA Astrophysics Data System (ADS)

Friedland, E.

2017-01-01

At ion energies with inelastic stopping powers less than a few keV/nm, radiation damage is thought to be due to atomic displacements by elastic collisions only. However, it is well known that inelastic processes and non-linear effects due to defect interaction within collision cascades can significantly increase or decrease damage efficiencies. The importance of these processes changes significantly along the ion trajectory and becomes negligible at some distance beyond the projected range, where damage is mainly caused by slowly moving secondary recoils. Hence, in this region amorphization energies should become independent of the ion type and only reflect the properties of the target lattice. To investigate this, damage profiles were obtained from α-particle channeling spectra of 6H-SiC wafers implanted at room temperature with ions in the mass range 84 ⩽ M ⩽ 133, employing the computer code DICADA. An average amorphization dose of (0.7 ± 0.2) dpa and critical damage energy of (17 ± 6) eV/atom are obtained from TRIM simulations at the experimentally observed boundary positions of the amorphous zones.

Blood glutamate scavenging as a novel neuroprotective treatment for paraoxon intoxication.

PubMed

Ruban, Angela; Mohar, Boaz; Jona, Ghil; Teichberg, Vivian I

2014-02-01

Organophosphate-induced brain damage is an irreversible neuronal injury, likely because there is no pharmacological treatment to prevent or block secondary damage processes. The presence of free glutamate (Glu) in the brain has a substantial role in the propagation and maintenance of organophosphate-induced seizures, thus contributing to the secondary brain damage. This report describes for the first time the ability of blood glutamate scavengers (BGS) oxaloacetic acid in combination with glutamate oxaloacetate transaminase to reduce the neuronal damage in an animal model of paraoxon (PO) intoxication. Our method causes a rapid decrease of blood Glu levels and creates a gradient that leads to the efflux of the excess brain Glu into the blood, thus reducing neurotoxicity. We demonstrated that BGS treatment significantly prevented the peripheral benzodiazepine receptor (PBR) density elevation, after PO exposure. Furthermore, we showed that BGS was able to rescue neurons in the piriform cortex of the treated rats. In conclusion, these results suggest that treatment with BGS has a neuroprotective effect in the PO intoxication. This is the first time that this approach is used in PO intoxication and it may be of high clinical significance for the future treatment of the secondary neurologic damage post organophosphates exposure.

Blood glutamate scavenging as a novel neuroprotective treatment for paraoxon intoxication

PubMed Central

Ruban, Angela; Mohar, Boaz; Jona, Ghil; Teichberg, Vivian I

2014-01-01

Organophosphate-induced brain damage is an irreversible neuronal injury, likely because there is no pharmacological treatment to prevent or block secondary damage processes. The presence of free glutamate (Glu) in the brain has a substantial role in the propagation and maintenance of organophosphate-induced seizures, thus contributing to the secondary brain damage. This report describes for the first time the ability of blood glutamate scavengers (BGS) oxaloacetic acid in combination with glutamate oxaloacetate transaminase to reduce the neuronal damage in an animal model of paraoxon (PO) intoxication. Our method causes a rapid decrease of blood Glu levels and creates a gradient that leads to the efflux of the excess brain Glu into the blood, thus reducing neurotoxicity. We demonstrated that BGS treatment significantly prevented the peripheral benzodiazepine receptor (PBR) density elevation, after PO exposure. Furthermore, we showed that BGS was able to rescue neurons in the piriform cortex of the treated rats. In conclusion, these results suggest that treatment with BGS has a neuroprotective effect in the PO intoxication. This is the first time that this approach is used in PO intoxication and it may be of high clinical significance for the future treatment of the secondary neurologic damage post organophosphates exposure. PMID:24149933

Amphetamines promote mitochondrial dysfunction and DNA damage in pulmonary hypertension

PubMed Central

Chen, Pin-I; Cao, Aiqin; Miyagawa, Kazuya; Tojais, Nancy F.; Hennigs, Jan K.; Li, Caiyun G.; Sweeney, Nathaly M.; Inglis, Audrey S.; Wang, Lingli; Li, Dan; Ye, Matthew; Feldman, Brian J.

2017-01-01

Amphetamine (AMPH) or methamphetamine (METH) abuse can cause oxidative damage and is a risk factor for diseases including pulmonary arterial hypertension (PAH). Pulmonary artery endothelial cells (PAECs) from AMPH-associated-PAH patients show DNA damage as judged by γH2AX foci and DNA comet tails. We therefore hypothesized that AMPH induces DNA damage and vascular pathology by interfering with normal adaptation to an environmental perturbation causing oxidative stress. Consistent with this, we found that AMPH alone does not cause DNA damage in normoxic PAECs, but greatly amplifies DNA damage in hypoxic PAECs. The mechanism involves AMPH activation of protein phosphatase 2A, which potentiates inhibition of Akt. This increases sirtuin 1, causing deacetylation and degradation of HIF1α, thereby impairing its transcriptional activity, resulting in a reduction in pyruvate dehydrogenase kinase 1 and impaired cytochrome c oxidase 4 isoform switch. Mitochondrial oxidative phosphorylation is inappropriately enhanced and, as a result of impaired electron transport and mitochondrial ROS increase, caspase-3 is activated and DNA damage is induced. In mice given binge doses of METH followed by hypoxia, HIF1α is suppressed and pulmonary artery DNA damage foci are associated with worse pulmonary vascular remodeling. Thus, chronic AMPH/METH can induce DNA damage associated with vascular disease by subverting the adaptive responses to oxidative stress. PMID:28138562

Altering Genomic Integrity: Heavy Metal Exposure Promotes Transposable Element-Mediated Damage.

PubMed

Morales, Maria E; Servant, Geraldine; Ade, Catherine; Roy-Engel, Astrid M

2015-07-01

Maintenance of genomic integrity is critical for cellular homeostasis and survival. The active transposable elements (TEs) composed primarily of three mobile element lineages LINE-1, Alu, and SVA comprise approximately 30% of the mass of the human genome. For the past 2 decades, studies have shown that TEs significantly contribute to genetic instability and that TE-caused damages are associated with genetic diseases and cancer. Different environmental exposures, including several heavy metals, influence how TEs interact with its host genome increasing their negative impact. This mini-review provides some basic knowledge on TEs, their contribution to disease, and an overview of the current knowledge on how heavy metals influence TE-mediated damage.

A Blend of Extracts from Houttuynia cordata, Nelumbo nucifera, and Camellia sinensis Protects Against Ethanol-Induced Liver Damage in C57BL/6 Mice.

PubMed

You, Yanghee; Lee, Hyunmi; Yoon, Ho-Geun; Park, Jeongjin; Kim, Ok-Kyung; Kim, Kyungmi; Lee, Min-Jae; Lee, Yoo-Hyun; Lee, Jeongmin; Jun, Woojin

2018-02-01

The protective activity of a mixture of aqueous and ethanolic extracts from Houttuynia cordata Thunb, Nelumbo nucifera G. leaves, and Camellia sinensis seed (HNC) was evaluated in C57BL/6 mice. Pretreatment with HNC prevented the elevation of serum aspartate aminotransferase and alanine aminotransferase caused by ethanol-induced hepatic damage. The HNC-treated mice showed significantly lower triglyceride levels, reduced CYP2E1 activity, and increased antioxidant enzyme activities and lipogenic mRNA levels. These results suggest that HNC might be a candidate agent for liver protection against ethanol-induced oxidative damage, through enhancement of antioxidant and antilipogenic activity.

The effect of nonablative laser energy on joint capsular properties. An in vitro histologic and biochemical study using a rabbit model

NASA Technical Reports Server (NTRS)

Hayashi, K.; Thabit, G. 3rd; Vailas, A. C.; Bogdanske, J. J.; Cooley, A. J.; Markel, M. D.

1996-01-01

The purpose of this study was to evaluate the effect of laser energy at nonablative levels on joint capsular histologic and biochemical properties in an in vitro rabbit model. The medial and lateral portions of the femoropatellar joint capsule from both stifles of 12 mature New Zealand White rabbits were used. Specimens were divided into three treatment groups (5 watts, 10 watts, and 15 watt) and one control group using a randomized block design. Specimens were placed in a 37 degrees bath of lactated Ringer's solution and laser energy was applied using a holmium:yttrium-aluminum-garnet laser in four transverse passes across the tissue at a velocity of 2 mm/sec with the handpiece set 1.5 mm from the synovial surface. Histologic analysis revealed thermal alteration of collagen (fusion) and fibroblasts (pyknosis) at all energy densities, with higher laser energy causing significantly greater morphologic changes over a larger area (P < 0.05). Application of laser energy did not significantly alter the biochemical parameters evaluated, including type I collagen content and nonreducible crosslinks (P > 0.05). This study demonstrated that nonablative laser energy caused significant thermal damage to the joint capsular tissue in an energy-dependent fashion, but type I collagen content and nonreducible crosslinks (P > 0.05). This study demonstrated that nonablative laser energy caused significant thermal damage to the joint capsular tissue in an energy-dependent fashion, but type I Collagen content and nonreducible corsslinks were not significantly altered.

Effects of damping-off caused by Rhizoctonia solani anastomosis group 2-1 on roots of wheat and oil seed rape quantified using X-ray Computed Tomography and real-time PCR

PubMed Central

Sturrock, Craig J.; Woodhall, James; Brown, Matthew; Walker, Catherine; Mooney, Sacha J.; Ray, Rumiana V.

2015-01-01

Rhizoctonia solani is a plant pathogenic fungus that causes significant establishment and yield losses to several important food crops globally. This is the first application of high resolution X-ray micro Computed Tomography (X-ray μCT) and real-time PCR to study host–pathogen interactions in situ and elucidate the mechanism of Rhizoctonia damping-off disease over a 6-day period caused by R. solani, anastomosis group (AG) 2-1 in wheat (Triticum aestivum cv. Gallant) and oil seed rape (OSR, Brassica napus cv. Marinka). Temporal, non-destructive analysis of root system architectures was performed using RooTrak and validated by the destructive method of root washing. Disease was assessed visually and related to pathogen DNA quantification in soil using real-time PCR. R. solani AG2-1 at similar initial DNA concentrations in soil was capable of causing significant damage to the developing root systems of both wheat and OSR. Disease caused reductions in primary root number, root volume, root surface area, and convex hull which were affected less in the monocotyledonous host. Wheat was more tolerant to the pathogen, exhibited fewer symptoms and developed more complex root systems. In contrast, R. solani caused earlier damage and maceration of the taproot of the dicot, OSR. Disease severity was related to pathogen DNA accumulation in soil only for OSR, however, reductions in root traits were significantly associated with both disease and pathogen DNA. The method offers the first steps in advancing current understanding of soil-borne pathogen behavior in situ at the pore scale, which may lead to the development of mitigation measures to combat disease influence in the field. PMID:26157449

Effects of damping-off caused by Rhizoctonia solani anastomosis group 2-1 on roots of wheat and oil seed rape quantified using X-ray Computed Tomography and real-time PCR.

PubMed

Sturrock, Craig J; Woodhall, James; Brown, Matthew; Walker, Catherine; Mooney, Sacha J; Ray, Rumiana V

2015-01-01

Rhizoctonia solani is a plant pathogenic fungus that causes significant establishment and yield losses to several important food crops globally. This is the first application of high resolution X-ray micro Computed Tomography (X-ray μCT) and real-time PCR to study host-pathogen interactions in situ and elucidate the mechanism of Rhizoctonia damping-off disease over a 6-day period caused by R. solani, anastomosis group (AG) 2-1 in wheat (Triticum aestivum cv. Gallant) and oil seed rape (OSR, Brassica napus cv. Marinka). Temporal, non-destructive analysis of root system architectures was performed using RooTrak and validated by the destructive method of root washing. Disease was assessed visually and related to pathogen DNA quantification in soil using real-time PCR. R. solani AG2-1 at similar initial DNA concentrations in soil was capable of causing significant damage to the developing root systems of both wheat and OSR. Disease caused reductions in primary root number, root volume, root surface area, and convex hull which were affected less in the monocotyledonous host. Wheat was more tolerant to the pathogen, exhibited fewer symptoms and developed more complex root systems. In contrast, R. solani caused earlier damage and maceration of the taproot of the dicot, OSR. Disease severity was related to pathogen DNA accumulation in soil only for OSR, however, reductions in root traits were significantly associated with both disease and pathogen DNA. The method offers the first steps in advancing current understanding of soil-borne pathogen behavior in situ at the pore scale, which may lead to the development of mitigation measures to combat disease influence in the field.

Anti-inflammatory and ameliorative effects of gallic acid on fluoxetine-induced oxidative stress and liver damage in rats.

PubMed

Karimi-Khouzani, Omid; Heidarian, Esfandiar; Amini, Sayed Asadollah

2017-08-01

Fluoxetine-induced liver damage is a cause of chronic liver disease. In the present study the hepatoprotective effects of gallic acid against fluoxetine-induced liver damage were examined. Forty-eight male rats were divided into six groups as follow: group 1, the control group; group 2, rats receiving fluoxetine (24mg/kg bw daily, po) without treatment; group 3, rats receiving 24mg/kg bw fluoxetine, treated with 50mg/kg bw silymarin and groups 4, 5, and 6 in which gallic acid (50, 100, and 200mg/kg bw, po, respectively) was prescribed after the consumption of fluoxetine. The histopathological changes of hepatic tissues were checked out. Fluoxetine caused a significant increase in the levels of serum glutamate oxaloacetate transaminase (GOT), serum glutamate pyruvate transaminase (GPT), lipid profiles, urea, fasting blood sugar (FBS), creatinine (Cr), protein carbonyl (PC) content, malondialdehyde (MDA), and liver TNF-α as an inflammatory element. Also, the obtained results of group 2 revealed a significant decline in ferric reducing ability of plasma (FRAP), liver catalase (CAT), superoxide dismutase (SOD), and vitamin C levels. The treatment with gallic acid showed significant ameliorations in abnormalities of fluoxetine-induced liver injury as represented by the improvement of hepatic CAT, SOD activities, vitamin C levels, serum biochemical parameters, and histopathological changes, in addition to the recovery of antioxidant defense system status. Gallic acid has inhibitory effects on fluoxetine-induced liver damage. The effect of gallic acid is derived from free radical scavenging properties and the anti-inflammatory effect related to TNF-α. Copyright © 2017. Published by Elsevier Urban & Partner Sp. z o.o.

Frequency analyses for recent regional floods in the United States

USGS Publications Warehouse

Melcher, Nick B.; Martinez, Patsy G.; ,

1996-01-01

During 1993-95, significant floods that resulted in record-high river stages, loss of life, and significant property damage occurred in the United States. The floods were caused by unique global weather patterns that produced large amounts of rain over large areas. Standard methods for flood-frequency analyses may not adequately consider the probability of recurrence of these global weather patterns.

Use of Citizen Science and Social Media to Improve Wind Hazard and Damage Characterization

NASA Astrophysics Data System (ADS)

Lombardo, F.; Meidani, H.

2017-12-01

Windstorm losses are significant in the U.S. annually and cause damage worldwide. A large percentage of losses are caused by localized events (e.g., tornadoes). In order to better mitigate these losses improvement is needed in understanding the hazard characteristics and physical damage. However, due to the small-scale nature of these events the resolution of the dedicated measuring network does not capture most occurrences. As a result damage-based assessments are sometimes used to gauge intensity. These damage assessments often suffer from a lack of available manpower, inability to arrive at the scene rapidly and difficulty accessing a damaged site. The use and rapid dissemination of social media, the power of crowds engaged in scientific endeavors, and the public's awareness of their vulnerabilities point to a paradigm shift in how hazards can be sensed in a rapid manner. In this way, `human-sensor' data has the potential to radically improve fundamental understanding of hazard and disasters and resolve some of the existing challenges in wind hazard and damage characterization. Data from social media outlets such as Twitter have been used to aid in damage assessments from hazards such as flood and earthquake, however, the reliability and uncertainty of participatory sensing has been questioned and has been called the `biggest challenge' for its sustained use. This research proposes to investigate the efficacy of both citizen science applications and social media data to represent wind hazards and associated damage. Research has focused on a two-phase approach: 1) to have citizen scientists perform their own `damage survey' (i.e., questionnaire) with known damage to assess uncertainty in estimation and 2) downloading and analysis of social media text and imagery streams to ascertain the possibility of performing `unstructured damage surveys'. Early results have shown that the untrained public can estimate tornado damage levels in residential structures with some accuracy. In addition, valuable windstorm hazard and damage information in both text and imagery can be extracted and archived from Twitter in an automated fashion. Information extracted from these sources will feed into advances in hazard and disaster modeling, social-cognitive theories of human behavior and decision-making for hazard mitigation.

AMPK Activation Prevents and Reverses Drug-Induced Mitochondrial and Hepatocyte Injury by Promoting Mitochondrial Fusion and Function

PubMed Central

Taniane, Caitlin; Farrell, Geoffrey; Arias, Irwin M.; Lippincott-Schwartz, Jennifer; Fu, Dong

2016-01-01

Mitochondrial damage is the major factor underlying drug-induced liver disease but whether conditions that thwart mitochondrial injury can prevent or reverse drug-induced liver damage is unclear. A key molecule regulating mitochondria quality control is AMP activated kinase (AMPK). When activated, AMPK causes mitochondria to elongate/fuse and proliferate, with mitochondria now producing more ATP and less reactive oxygen species. Autophagy is also triggered, a process capable of removing damaged/defective mitochondria. To explore whether AMPK activation could potentially prevent or reverse the effects of drug-induced mitochondrial and hepatocellular damage, we added an AMPK activator to collagen sandwich cultures of rat and human hepatocytes exposed to the hepatotoxic drugs, acetaminophen or diclofenac. In the absence of AMPK activation, the drugs caused hepatocytes to lose polarized morphology and have significantly decreased ATP levels and viability. At the subcellular level, mitochondria underwent fragmentation and had decreased membrane potential due to decreased expression of the mitochondrial fusion proteins Mfn1, 2 and/or Opa1. Adding AICAR, a specific AMPK activator, at the time of drug exposure prevented and reversed these effects. The mitochondria became highly fused and ATP production increased, and hepatocytes maintained polarized morphology. In exploring the mechanism responsible for this preventive and reversal effect, we found that AMPK activation prevented drug-mediated decreases in Mfn1, 2 and Opa1. AMPK activation also stimulated autophagy/mitophagy, most significantly in acetaminophen-treated cells. These results suggest that activation of AMPK prevents/reverses drug-induced mitochondrial and hepatocellular damage through regulation of mitochondrial fusion and autophagy, making it a potentially valuable approach for treatment of drug-induced liver injury. PMID:27792760

Assessing the Cost of an Invasive Forest Pathogen: A Case Study with Oak Wilt

NASA Astrophysics Data System (ADS)

Haight, Robert G.; Homans, Frances R.; Horie, Tetsuya; Mehta, Shefali V.; Smith, David J.; Venette, Robert C.

2011-03-01

Economic assessment of damage caused by invasive alien species provides useful information to consider when determining whether management programs should be established, modified, or discontinued. We estimate the baseline economic damage from an invasive alien pathogen, Ceratocystis fagacearum, a fungus that causes oak wilt, which is a significant disease of oaks ( Quercus spp.) in the central United States. We focus on Anoka County, Minnesota, a 1,156 km2 mostly urban county in the Minneapolis-Saint Paul metropolitan region. We develop a landscape-level model of oak wilt spread that accounts for underground and overland pathogen transmission. We predict the economic damage of tree mortality from oak wilt spread in the absence of management during the period 2007-2016. Our metric of economic damage is removal cost, which is one component of the total economic loss from tree mortality. We estimate that Anoka County has 5.92 million oak trees and 885 active oak wilt pockets covering 5.47 km2 in 2007. The likelihood that landowners remove infected oaks varies by land use and ranges from 86% on developed land to 57% on forest land. Over the next decade, depending on the rates of oak wilt pocket establishment and expansion, 76-266 thousand trees will be infected with discounted removal cost of 18-60 million. Although our predictions of removal costs are substantial, they are lower bounds on the total economic loss from tree mortality because we do not estimate economic losses from reduced services and increased hazards. Our predictions suggest that there are significant economic benefits, in terms of damage reduction, from preventing new pocket establishment or slowing the radial growth of existing pockets.

DNA damage in haemocytes and midgut gland cells of Steatoda grossa (Theridiidae) spiders exposed to food contaminated with cadmium.

PubMed

Stalmach, Monika; Wilczek, Grażyna; Wilczek, Piotr; Skowronek, Magdalena; Mędrzak, Monika

2015-03-01

The aim of this study was to assess the genotoxic effects of Cd on haemocytes and midgut gland cells of web-building spiders, Steatoda grossa (Theridiidae), exposed to the metal under laboratory conditions. Analyzes were conducted on adult females and males, fed for four weeks with cadmium-contaminated Drosophila hydei flies, grown on a medium suplemented with 0.25 mM CdCl2. The comet assay, providing a quantitative measure of DNA strand breaks, was used to evaluate the DNA damage caused by the metal. Cadmium content was measured in whole spider bodies by the AAS method. Metal body burden was significantly lower in females (0.25 µgg(-1) dry weight) than in males (3.03 µgg(-1) dry weight), suggesting that females may have more effective mechanisms controlling the uptake of metal, via the digestive tract, or its elimination from the body. Irrespectively of sex, spiders fed prey contaminated with cadmium showed significantly higher values of comet parameters: tail DNA (TDNA), tail length (TL) and olive tail moment (OTM), in comparison with the control. In midgut gland cells, the level of DNA damage was higher for males than females, while in haemocytes the genotoxic effect of cadmium was greater in females. The obtained results indicate that in spiders cadmium displays strong genotoxic effects and may cause DNA damage even at low concentrations, however the severity of damage seems to be sex- and internal organ-dependent. The comet assay can be considered a sensitive tool for measuring the deleterious effect of cadmium on DNA integrity in spiders. Copyright © 2014 Elsevier Inc. All rights reserved.

Exposure to Ultrafine Particles from Ambient Air and Oxidative Stress–Induced DNA Damage

PubMed Central

Bräuner, Elvira Vaclavik; Forchhammer, Lykke; Møller, Peter; Simonsen, Jacob; Glasius, Marianne; Wåhlin, Peter; Raaschou-Nielsen, Ole; Loft, Steffen

2007-01-01

Background Particulate matter, especially ultrafine particles (UFPs), may cause health effects through generation of oxidative stress, with resulting damage to DNA and other macromolecules. Objective We investigated oxidative damage to DNA and related repair capacity in peripheral blood mononuclear cells (PBMCs) during controlled exposure to urban air particles with assignment of number concentration (NC) to four size modes with average diameters of 12, 23, 57, and 212 nm. Design Twenty-nine healthy adults participated in a randomized, two-factor cross-over study with or without biking exercise for 180 min and with exposure to particles (NC 6169-15362/cm3) or filtered air (NC 91-542/cm3) for 24 hr. Methods The levels of DNA strand breaks (SBs), oxidized purines as formamidopyrimidine DNA glycolase (FPG) sites, and activity of 7,8-dihydro-8-oxoguanine-DNA glycosylase (OGG1) in PBMCs were measured by the Comet assay. mRNA levels of OGG1, nucleoside diphosphate linked moiety X-type motif 1 (NUDT1), and heme oxygenase-1 (HO1) were determined by real-time reverse transcriptase–polymerase chain reaction. Results Exposure to UFPs for 6 and 24 hr significantly increased the levels of SBs and FPG sites, with a further insignificant increase after physical exercise. The OGG1 activity and expression of OGG1, NUDT1, and HO1 were unaltered. There was a significant dose–response relationship between NC and DNA damage, with the 57-nm mode as the major contributor to effects. Concomitant exposure to ozone, nitrogen oxides, and carbon monoxide had no influence. Conclusion Our results indicate that UFPs, especially the 57-nm soot fraction from vehicle emissions, causes systemic oxidative stress with damage to DNA and no apparent compensatory up-regulation of DNA repair within 24 hr. PMID:17687444

Hyperglycemia induced damage to mitochondrial respiration in renal mesangial and tubular cells: Implications for diabetic nephropathy.

PubMed

Czajka, Anna; Malik, Afshan N

2016-12-01

Damage to renal tubular and mesangial cells is central to the development of diabetic nephropathy (DN), a complication of diabetes which can lead to renal failure. Mitochondria are the site of cellular respiration and produce energy in the form of ATP via oxidative phosphorylation, and mitochondrial dysfunction has been implicated in DN. Since the kidney is an organ with high bioenergetic needs, we postulated that hyperglycemia causes damage to renal mitochondria resulting in bioenergetic deficit. The bioenergetic profiles and the effect of hyperglycemia on cellular respiration of human primary mesangial (HMCs) and proximal tubular cells (HK-2) were compared in normoglycemic and hyperglycemic conditions using the seahorse bio-analyzer. In normoglycemia, HK-2 had significantly lower basal, ATP-linked and maximal respiration rates, and lower reserve capacity compared to HMCs. Hyperglycemia caused a down-regulation of all respiratory parameters within 4 days in HK-2 but not in HMCs. After 8 days of hyperglycemia, down-regulation of respiratory parameters persisted in tubular cells with compensatory up-regulated glycolysis. HMCs had reduced maximal respiration and reserve capacity at 8 days, and by 12 days had compromised mitochondrial respiration despite which they did not enhance glycolysis. These data suggest that diabetes is likely to lead to a cellular deficit in ATP production in both cell types, although with different sensitivities, and this mechanism could significantly contribute to the cellular damage seen in the diabetic kidney. Prevention of diabetes induced damage to renal mitochondrial respiration may be a novel therapeutic approach for the prevention/treatment of DN. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Different DNA damage and cell cycle checkpoint control in low- and high-risk human papillomavirus infections of the vulva.

PubMed

Santegoets, Lindy A M; van Baars, Romy; Terlou, Annelinde; Heijmans-Antonissen, Claudia; Swagemakers, Sigrid M A; van der Spek, Peter J; Ewing, Patricia C; van Beurden, Marc; van der Meijden, Willem I; Helmerhorst, Theo J M; Blok, Leen J

2012-06-15

Human papillomavirus (HPV) infections may result in benign hyperplasia, caused by low-risk HPV types, or (pre)malignant lesions caused by high-risk HPV types. The molecular basis of this difference in malignant potential is not completely understood. Here, we performed gene profiling of different HPV infected vulvar tissues (condylomata acuminata (n = 5), usual type vulvar intraepithelial neoplasia (uVIN) (n = 9)) and control samples (n = 14) using Affymetrix Human U133A plus 2 GeneChips. Data were analyzed using OmniViz®, Partek® and Ingenuity® Software. Results were validated by real-time RT-PCR and immunostaining. Although similarities were observed between gene expression profiles of low- and high-risk HPV infected tissues (e.g., absence of estrogen receptor in condylomata and uVIN), high-risk HPV infected tissues showed more proliferation and displayed more DNA damage than tissues infected with low-risk HPV. These observations were confirmed by differential regulation of cell cycle checkpoints and by increased expression of DNA damage-biomarkers p53 and γH2AX. Furthermore, FANCA, FANCD2, BRCA1 and RAD51, key players in the DNA damage response, were significantly upregulated (p < 0.05). In addition, we compared our results with publicly available gene expression profiles of various other HPV-induced cancers (vulva, cervix and head-and-neck). This showed p16(INK4a) was the most significant marker to detect a high-risk HPV infection, but no other markers could be found. In conclusion, this study provides insight into the molecular basis of low- and high-risk HPV infections and indicates two main pathways (cell cycle and DNA damage response) that are much stronger affected by high-risk HPV as compared to low-risk HPV. Copyright © 2011 UICC.

Repellent response of female agromyzid flies to leafminer-infested bean plants

USDA-ARS?s Scientific Manuscript database

Liriomyza sativae Blanchard, L. trifolii (Burgess) and L. huidobrensis (Blanchard) are three invasive leafminer species (Diptera: Agromyzidae) in China that have caused significant economic damage on vegetables and ornamental plants. In the current study, the repellent responses of female adults to ...

Occupational exposure to asphalt fume can cause oxidative DNA damage among road paving workers.

PubMed

Bal, Ceylan; Ağış, Erol R; Büyükşekerci, Murat; Gündüzöz, Meşide; Tutkun, Lütfiye; Yılmaz, Ömer H

2018-06-01

We designed the present study to determine the effect of occupational exposure to asphalt fumes on oxidative status and DNA damage in road paving workers. Sixty road paving workers exposed to asphalt fumes and forty non-exposed control subjects were recruited. Occupational exposure to PAHs was assessed by urinary 1-hydroxypyrene (1-OHP) excretion. Serum thiol disulfide homeostasis (TDH), total oxidant status (TOS) and total antioxidant status (TAS) and urinary 8-hydro-deoxyguanosine (8-OH-dG) level were evaluated by automated colourimetric method. The urinary concentrations of 1-OHP and 8-OH-dG were significantly higher in the exposed group than in the control group (P < 0.001). Disulfide/thiol ratio, TOS, and TAS were also significantly higher for the asphalt workers. A positive correlation existed between urinary 1-OHP and 8-OH-dG, TOS and TAS. Study results indicate that exposure to PAHs induces oxidative stress and causes genotoxic effects in asphalt workers. © 2018 Wiley Periodicals, Inc.

High-quality care improves outcome in recumbent dairy cattle.

PubMed

Poulton, P J; Vizard, A L; Anderson, G A; Pyman, M F

2016-06-01

To investigate the influence of the quality of care on outcome and occurrence of secondary damage in recumbent dairy cows. Recumbent dairy cows were monitored during their recumbency under field conditions in South Gippsland, Victoria, Australia. The cause of the original recumbency of 218 downer cows was determined and any secondary damage, day 7 status, final outcome and the nursing conditions of the cows were recorded. A four-tiered grading system describing nursing quality was developed to allow analysis of its influence on outcome and on the occurrence of secondary damage. Day 7 outcome, final outcome and occurrence of important secondary damage were very strongly associated with the level of overall care provided to the recumbent cows. There was a decrease in the percentage of cows recovering by day 7 from 33% to 0%, a decrease from 45% to 0% of cows eventually recovering and an increase from 68% to 100% of cows with clinically important secondary damage as overall care decreased. Management of recumbent cattle is potentially a significant animal welfare issue for the dairy industry and their care is a very important but often under-appreciated aspect of their management. Recovery is positively influenced by high-quality care by improving the chances of recovery from the initial cause of recumbency and by reducing the occurrence of secondary damage. Recumbent cows must either be nursed at a high level of care or euthanased promptly. © 2016 Australian Veterinary Association.

Comparison of heat induced damage at the saphenofemoral junction after ablation with 1,470 nm laser or radiofrequency.

PubMed

Ozcinar, Evren; Cakici, Mehmet; Korun, Oktay; Han, Unsal; Kiziltepe, Ugursay

2017-03-01

The aim of this study was to evaluate the heat induced damage at the saphenofemoral junction level according to histopathological changes after radiofrequency or 1,470 nm radial tip laser ablation. Varicose vein segments of 6-10 mm in diameter were exposed to radiofrequency (Closure Fast catheter, 7 cm heat segment, one cycle, 15 seconds, 10 Watt, 120 °C) or laser ablation (1,470 nm radial tip, continuous wave, vein diameter: 6 cm/8 cm/10 cm-power: 10 Watt-pullback speed: 2.2 mm/s, 1.7 mm/s, 1.3 mm/s-LEED: 45J/cm, 60J/cm, 75J/cm-EFE 25J/cm 2 , respectively). Approximate 2 cm segments of the vein were left untreated, then histopathological examinations of the untouched segments (5 slices: level 1 - furthest segment, level 2 - nearest segment) for heat induced damage were performed. A total damage scoring system was established, including the presence of endothelial swelling, intimal thickening, cellular vacuolisation in the muscle layer, oedema in the tunica media, and extent of necrosis. At level 1, the furthest segment of the specimen, there was no significant difference between the laser and control group, while the total damage score of the radiofrequency group was significantly higher than the control group (p < 0.01). Radiofrequency group had higher total damage score compared to the laser group at level 1 (p < 0.01), 2 (p < 0.01), and 5 (p < 0.01); while no significant difference was observed at level 3 (p = 0.46) and 4 (p = 0.13). Significant heat induced damage may be seen even if the 2 cm segment of the vessel is left unablated. Radiofrequency ablation seems to cause more histological damage than laser ablation in this ex vivo study. Further in vivo studies are necessary, in order to validate these findings.

Radiation and Thermal Ageing of Nuclear Waste Glass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weber, William J

2014-01-01

The radioactive decay of fission products and actinides incorporated into nuclear waste glass leads to self-heating and self-radiation effects that may affect the stability, structure and performance of the glass in a closed system. Short-lived fission products cause significant self-heating for the first 600 years. Alpha decay of the actinides leads to self-radiation damage that can be significant after a few hundred years, and over the long time periods of geologic disposal, the accumulation of helium and radiation damage from alpha decay may lead to swelling, microstructural evolution and changes in mechanical properties. Four decades of research on the behaviormore » of nuclear waste glass are reviewed.« less

Genotoxicity profiles in exfoliated human mammary cells recovered from lactating mothers in Istanbul; relationship with demographic and dietary factors.

PubMed

Yilmaz, Bayram; Sandal, Suleyman; Ayvaci, Habibe; Tug, Niyazi; Vitrinel, Ayca

2012-12-12

We have investigated the presence of DNA damage in human mammary epithelial cells collected from healthy lactating mothers (age, 20-35 years) who were resident in the Istanbul area. Breast milk (10ml) was collected from 30 women between one and two weeks post-partum. Demographic information (parity, breast cancer, occupation, duration of residency in Istanbul, consumption of fish, beef and poultry) was also obtained. Milk samples were diluted 1:1 with RPMI 1640 medium and centrifuged to collect cells. The cells were re-suspended and cell viability was determined by use of 0.4% trypan blue. DNA damage was assessed by use of the comet assay (alkaline single-cell gel electrophoresis). Fifty cells per slide and two slides per sample were scored to evaluate DNA damage. The cells were visually classified into four categories on the basis of extent of migration: undamaged (UD), lightly damaged (LD), moderately damaged (MD) and highly damaged (HD). Total comet scores (TCS) were calculated as: 1× UD+2× LD+3× MD+4× HD. Exfoliated mammary cells of the donors showed high (TCS≥150a.u.), moderate and low DNA damage in 10 (33.3%), 8 (26.7%) and 12 (40%) mothers, respectively. There was no significant correlation between TCS for DNA damage and the duration of previous breastfeeding, parity or age. None of the mothers was vegetarian, smoker or on any medication. Meat and chicken consumption did not significantly correlate with the TCS values. Fish consumption was significantly correlated with TCS results (Spearman's rho=0.39, p<0.05). No significant correlation was found between the DNA-damage scores and the period of residency in Istanbul, but fish consumption increased as the duration of stay was longer (Spearman's rho=0.53, p<0.01). These findings suggest that the primary causes of differences in genotoxicity detected in lactating mothers in Istanbul may be of dietary origin. Our experience also confirms that sampling breast milk from lactating mothers provides a valuable and non-invasive tool to study DNA damage in mammary cells. Copyright © 2012 Elsevier B.V. All rights reserved.

Toxic effects and possible mechanisms of hydrogen sulfide and/or ammonia on porcine oocyte maturation in vitro.

PubMed

Yang, Lei-Lei; Zhao, Yong; Luo, Shi-Ming; Ma, Jun-Yu; Ge, Zhao-Jia; Shen, Wei; Yin, Shen

2018-03-15

Previous studies suggest that hydrogen sulfide (H 2 S) and ammonia (NH 3 ) are two major air pollutants which can cause damage to porcine health. However, the mechanisms underlying toxic effects of these compounds on porcine oocyte maturation are not clear. To clarify the mechanism, we evaluated the oocyte quality by detecting some events during oocytes maturation. In our study, porcine oocytes were cultured with different concentrations of Na 2 S and/or NH 4 Cl in vitro and the rate of the first polar body extrusion decreased significantly. Also, actin filament was seriously disrupted to damage the cytoskeleton which resulted in reduced rate of oocyte maturation. We explored the reactive oxygen species (ROS) generation and found that the ROS level was increased significantly after Na 2 S treatment but not after NH 4 Cl treatment. Moreover, early stage apoptosis rate was significantly increased and autophagy protein LC3 B expression level was higher in oocytes treated with Na 2 S and/or NH 4 Cl, which might be caused by ROS elevation. Additionally, exposure to Na 2 S and/or NH 4 Cl also caused ROS generation and early apoptosis in cumulus cells, which might further affect oocyte maturation in vitro. In summary, our data suggested that exposure to H 2 S and/or NH 3 decreased porcine oocyte maturation in vitro, which might be caused by actin disruption, ROS generation, early apoptosis and autophagy. Copyright © 2017 Elsevier B.V. All rights reserved.

Protective Role for Antioxidants in Acute Kidney Disease

PubMed Central

Dennis, Joanne M.; Witting, Paul K.

2017-01-01

Acute kidney injury causes significant morbidity and mortality in the community and clinic. Various pathologies, including renal and cardiovascular disease, traumatic injury/rhabdomyolysis, sepsis, and nephrotoxicity, that cause acute kidney injury (AKI), induce general or regional decreases in renal blood flow. The ensuing renal hypoxia and ischemia promotes the formation of reactive oxygen species (ROS) such as superoxide radical anions, peroxides, and hydroxyl radicals, that can oxidatively damage biomolecules and membranes, and affect organelle function and induce renal tubule cell injury, inflammation, and vascular dysfunction. Acute kidney injury is associated with increased oxidative damage, and various endogenous and synthetic antioxidants that mitigate source and derived oxidants are beneficial in cell-based and animal studies. However, the benefit of synthetic antioxidant supplementation in human acute kidney injury and renal disease remains to be realized. The endogenous low-molecular weight, non-proteinaceous antioxidant, ascorbate (vitamin C), is a promising therapeutic in human renal injury in critical illness and nephrotoxicity. Ascorbate may exert significant protection by reducing reactive oxygen species and renal oxidative damage via its antioxidant activity, and/or by its non-antioxidant functions in maintaining hydroxylase and monooxygenase enzymes, and endothelium and vascular function. Ascorbate supplementation may be particularly important in renal injury patients with low vitamin C status. PMID:28686196

Morphological study of bone marrow to assess the effects of lead acetate on haemopoiesis and aplasia and the ameliorating role of Carica papaya extract

PubMed Central

THAM, CHING S.; CHAKRAVARTHI, SRIKUMAR; HALEAGRAHARA, NAGARAJA; DE ALWIS, RANJIT

2013-01-01

Lead causes damage to the body by inducing oxidative stress. The sites of damage include the bone marrow, where marrow hypoplasia and osteosclerosis may be observed. Leaves of Carica papaya, which have antioxidant and haemopoietic properties, were tested against the effect of lead acetate in experimental rats. The rats were divided into 8 groups; control, lead acetate only, Carica papaya (50 mg and 200 mg), post-treatment with Carica papaya (50 mg and 200 mg) following lead acetate administration and pre-treatment with Carica papaya (50 mg and 200 mg) followed by lead acetate administration. The substances were administered for 14 days. The effects were evaluated by measuring protein carbonyl content (PCC) and glutathione content (GC) in the bone marrow. Histological changes in the bone marrow were also observed. The results showed that Carica papaya induced a significant reduction in the PCC activity and significantly increased the GC in the bone marrow. Carica papaya also improved the histology of the bone marrow compared with that of the lead acetate-treated group. In summary, Carica papaya was effective against the oxidative damage caused by lead acetate in the bone marrow and had a stimulatory effect on haemopoiesis. PMID:23403524

Morphological study of bone marrow to assess the effects of lead acetate on haemopoiesis and aplasia and the ameliorating role of Carica papaya extract.

PubMed

Tham, Ching S; Chakravarthi, Srikumar; Haleagrahara, Nagaraja; DE Alwis, Ranjit

2013-02-01

Lead causes damage to the body by inducing oxidative stress. The sites of damage include the bone marrow, where marrow hypoplasia and osteosclerosis may be observed. Leaves of Carica papaya, which have antioxidant and haemopoietic properties, were tested against the effect of lead acetate in experimental rats. The rats were divided into 8 groups; control, lead acetate only, Carica papaya (50 mg and 200 mg), post-treatment with Carica papaya (50 mg and 200 mg) following lead acetate administration and pre-treatment with Carica papaya (50 mg and 200 mg) followed by lead acetate administration. The substances were administered for 14 days. The effects were evaluated by measuring protein carbonyl content (PCC) and glutathione content (GC) in the bone marrow. Histological changes in the bone marrow were also observed. The results showed that Carica papaya induced a significant reduction in the PCC activity and significantly increased the GC in the bone marrow. Carica papaya also improved the histology of the bone marrow compared with that of the lead acetate-treated group. In summary, Carica papaya was effective against the oxidative damage caused by lead acetate in the bone marrow and had a stimulatory effect on haemopoiesis.

The genotoxic effect of oxcarbazepine on mice blood lymphocytes.

PubMed

Akbar, Huma; Khan, Ajmal; Mohammadzai, Imdadullah; Khisroon, Muhammad; Begum, Ilham

2018-04-01

This study was conducted to assess the amount of DNA damage caused by Oxcarbazepine (OXC) through single cell gel electrophoresis (SCGE) technique/comet assay. OXC derived from dibenzazepine series is an effective second generation antiepileptic drug (AED) for both children and adults. Side effects like genotoxic effects of AEDs are of prime importance resulting from toxic metabolites, free radicals and reactive oxygen species (ROS). Forty Eight adult male Bagg's albino mice (BALB/c) were randomly classified into eight groups, each comprising of six animals. Two of these groups were control and six were tested groups. Control groups were injected with 1% tween 80 while tested groups were injected with 10, 20, and 40 mg/kg-day OXC for seven days (acute therapy) and 28 days (subchronic therapy) in peritoneal cavity. Blood samples were collected by cardiac puncture and subjected to comet assay for the analysis of DNA damage. Per sample 100 cells were scored and classified according to comet tail length. The results showed that OXC in acute and long term therapies had significantly higher (p < 0.05) genotoxicity in treated groups as compared to control groups. Our study suggests that OXC may cause significant DNA damage in both acute as well as in subchronic therapies.

Binder of Sperm Proteins protect ram spermatozoa from freeze-thaw damage.

PubMed

Pini, Taylor; Farmer, Kiri; Druart, Xavier; Teixeira-Gomes, Ana Paula; Tsikis, Guillaume; Labas, Valerie; Leahy, Tamara; de Graaf, Simon P

2018-06-01

Cryopreservation causes sub-lethal damage which limits the fertility of frozen thawed spermatozoa. Seminal plasma has been investigated as a cryoprotectant, but has yielded inconsistent results due to considerable variation in its constituents. Individual seminal plasma proteins offer an ideal alternative to whole seminal plasma, and several have been correlated with freezing success. Binder of Sperm Proteins (BSPs) are abundant ram seminal plasma proteins which have been suggested to have significant protective effects on ram spermatozoa during cold shock. This is in direct opposition to bull spermatozoa, where BSPs cause sperm deterioration during in vitro handling. We investigated the potential of BSP1 and BSP5 to prevent freezing associated damage to important functional parameters of ram spermatozoa. BSPs purified by size exclusion chromatography improved post thaw motility and penetration through artificial mucus. Highly purified BSP1 and BSP5, isolated by gelatin affinity and RP-HPLC, improved motility and membrane integrity, and reduced post thaw protein tyrosine phosphorylation. Exposure to BSP5 before freezing increased the amount of phosphatidylethanolamine on the sperm surface after thawing. Neither BSP1 nor BSP5 prevented freezing associated changes in membrane lipid disorder. These results suggest that BSPs may significantly improve freezing outcomes of ram spermatozoa. Copyright © 2018 Elsevier Inc. All rights reserved.

Management of acute, recurrent, and chronic meningitides in adults.

PubMed

Cho, Tracey A; Venna, Nagagopal

2010-11-01

Meningitis (inflammation of the pia, arachnoid, and sometimes dura) has diverse causes and presentations. Although viruses are the most common cause of acute meningitis, bacterial meningitides are more severe and important to exclude because morbidity and mortality are high. Chronic meningitis has a broader range of causes, including atypical bacteria, fungi, and noninfectious causes. Presentation is more insidious but, if untreated, significant damage or death may ensue. Recurrent meningitis has many of the same causes as chronic meningitis, but manifestations occur in discrete episodes. Distinguishing between acute, chronic, and recurrent meningitis is essential for proper diagnostic testing and treatment approaches. Copyright 2010 Elsevier Inc. All rights reserved.

Damage from wind and other causes in mixed white fir-red fir stands adjacent to clearcuttings

Treesearch

Donald T. Gordon

1973-01-01

Damage to timber surrounding clearcuttings and in one light selection cutting in mixed white fir-red fir stands was monitored for 6 years in northeastern California. In some years, bark beetles apparently killed more trees than did wind damage, but in two of the study years, severe wind storms caused much damage. One storm produced mainly break-age, apparently...

Widespread ground motion distribution caused by rupture directivity during the 2015 Gorkha, Nepal earthquake

NASA Astrophysics Data System (ADS)

Koketsu, Kazuki; Miyake, Hiroe; Guo, Yujia; Kobayashi, Hiroaki; Masuda, Tetsu; Davuluri, Srinagesh; Bhattarai, Mukunda; Adhikari, Lok Bijaya; Sapkota, Soma Nath

2016-06-01

The ground motion and damage caused by the 2015 Gorkha, Nepal earthquake can be characterized by their widespread distributions to the east. Evidence from strong ground motions, regional acceleration duration, and teleseismic waveforms indicate that rupture directivity contributed significantly to these distributions. This phenomenon has been thought to occur only if a strike-slip or dip-slip rupture propagates to a site in the along-strike or updip direction, respectively. However, even though the earthquake was a dip-slip faulting event and its source fault strike was nearly eastward, evidence for rupture directivity is found in the eastward direction. Here, we explore the reasons for this apparent inconsistency by performing a joint source inversion of seismic and geodetic datasets, and conducting ground motion simulations. The results indicate that the earthquake occurred on the underthrusting Indian lithosphere, with a low dip angle, and that the fault rupture propagated in the along-strike direction at a velocity just slightly below the S-wave velocity. This low dip angle and fast rupture velocity produced rupture directivity in the along-strike direction, which caused widespread ground motion distribution and significant damage extending far eastwards, from central Nepal to Mount Everest.

Biological research on fire in the West

USGS Publications Warehouse

,

2005-01-01

Wildland fires are a natural feature of many ecosystems, including grasslands, forests, and shrublands. How-ever, years of fire exclusion have led to accumulations of dead fuels and increases in the density of fire-intolerant species. In most western states, recent fires burning in these altered ecosystems have caused significant damage and huge economic losses to homes, busi-nesses, and communities. They also have dis-turbed forests and rangelands as well as their associated watersheds, plants, and animals. Every western state is concerned about dam-age from such catastrophic fires, and there is strong interest from all sectors in prevent-ing and reducing the resulting damage in the future. There is also interest in the use of fire as a management tool for reducing hazards and restoring damaged ecosystems and for returning fire to its natural role in wilderness ecosystems.

An in vitro investigation of the temperature rises produced in dentine by Nd:YAG laser light with and without water cooling.

PubMed

Gow, A M; McDonald, A V; Pearson, G J; Setchell, D J

1999-01-01

Infrared lasers are reported to have thermal side effects which may damage pulp tissue. This study investigated the thermal effects of the pulsed Nd:YAG laser. Prepared, extracted teeth were measured prior to irradiation. Temperature was recorded using a thermocouple/data logging system. Laser irradiation was carried out with or without water spray for an exposure time of ten seconds. Results indicated that dry irradiation produced unacceptable temperature rises with dentine thicknesses used. Wet irradiation produced a significantly lower temperature rise. It was concluded that the Nd:YAG laser produced thermal effects which could potentially cause pulpal trauma. A water coolant was effective in reducing these thermal effects, but the temperature rise achieved whilst using water coolant may still cause pulpal damage.

Nitrative DNA damage induced by multi-walled carbon nanotube via endocytosis in human lung epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Feiye, E-mail: zhizi0269@doc.medic.mie-u.ac.jp; Ma, Ning, E-mail: maning@suzuka-u.ac.jp; Horibe, Yoshiteru, E-mail: violinteru@yahoo.co.jp

Carbon nanotube (CNT) has a promising usage in the field of material science for industrial purposes because of its unique physicochemical property. However, intraperitoneal administration of CNT was reported to cause mesothelioma in experimental animals. Chronic inflammation may contribute to carcinogenesis induced by fibrous materials. 8-Nitroguanine is a mutagenic DNA lesion formed during inflammation and may play a role in CNT-induced carcinogenesis. In this study, we examined 8-nitroguanine formation in A549 human lung alveolar epithelial cells treated with multi-walled CNT (MWCNT) by fluorescent immunocytochemistry. Both MWCNTs with diameter of 20–30 nm (CNT20) and 40–70 nm (CNT40) significantly induced 8-nitroguanine formationmore » at 5 and 10 μg/ml (p < 0.05), which persisted for 24 h, although there was no significant difference in DNA-damaging abilities of these MWCNTs. MWCNTs significantly induced the expression of inducible nitric oxide synthase (iNOS) for 24 h (p < 0.05). MWCNTs also significantly increased the level of nitrite, a hydrolysis product of oxidized NO, in the culture supernatant at 4 and 8 h (p < 0.05). MWCNT-induced 8-nitroguanine formation and iNOS expression were largely suppressed by inhibitors of iNOS (1400 W), nuclear factor-κB (Bay11-7082), actin polymerization (cytochalasin D), caveolae-mediated endocytosis (methyl-β-cyclodextrin, MBCD) and clathrin-mediated endocytosis (monodansylcadaverine, MDC). Electron microscopy revealed that MWCNT was mainly located in vesicular structures in the cytoplasm, and its cellular internalization was reduced by MBCD and MDC. These results suggest that MWCNT is internalized into cells via clathrin- and caveolae-mediated endocytosis, leading to inflammatory reactions including iNOS expression and resulting nitrative DNA damage, which may contribute to carcinogenesis. Highlights: ►Multi-walled carbon nanotube (MWCNT) caused DNA damage in A549 cells. ►MWCNT formed 8-nitroguanine, a DNA lesion associated with inflammatory response. ►MWCNT was internalized into cells via caveolin- and clathrin-mediated endocytosis. ►8-Nitroguanine formation and iNOS expression involved these types of endocytosis. ►Internalized MWCNT plays a key role in inflammatory response and DNA damage.« less

Damage assessment of RC buildings subjected to the different strong motion duration

NASA Astrophysics Data System (ADS)

Mortezaei, Alireza; mohajer Tabrizi, Mohsen

2015-07-01

An earthquake has three important characteristics; namely, amplitude, frequency content and duration. Amplitude and frequency content have a direct impact but not necessarily the sole cause of structural damage. Regarding the duration, some researchers show a high correlation between strong motion duration and structural damage whereas some others find no relation. This paper focuses on the ground motion durations characterized by Arias Intensity (AI). High duration may increase the damage state of structure for the damage accumulation. This paper investigates the response time histories (acceleration, velocity and displacement) of RC buildings under the different strong motion durations. Generally, eight earthquake records were selected from different soil type, and these records were grouped according to their PGA and frequency ranges. Maximum plastic rotation and drift response was chosen as damage indicator. In general, there was a positive correlation between strong motion duration and damage; however, in some PGA and frequency ranges input motions with shorter durations might cause more damage than the input motions with longer durations. In soft soils, input motions with longer durations caused more damage than the input motions with shorter durations.

Characterization of UVC-induced DNA damage in bloodstains: forensic implications.

PubMed

Hall, Ashley; Ballantyne, Jack

2004-09-01

The ability to detect DNA polymorphisms using molecular genetic techniques has revolutionized the forensic analysis of biological evidence. DNA typing now plays a critical role within the criminal justice system, but one of the limiting factors with the technology is that DNA isolated from biological stains recovered from the crime scene is sometimes so damaged as to be intractable to analysis. Potential remedies for damaged DNA are likely to be dependent upon the precise nature of the DNA damage present in any particular sample but, unfortunately, current knowledge of the biochemical nature, and the extent, of such DNA damage in dried biological stains is rudimentary. As a model for DNA damage assessment in biological stains recovered from crime scenes, we have subjected human bloodstains and naked DNA in the hydrated and dehydrated states to varying doses of UVC radiation. It was possible to damage the DNA sufficiently in a bloodstain to cause a standard autosomal short tandem repeat (STR) profile to be lost. However, a detailed analysis of the process, based upon assays developed to detect bipyrimidine photoproducts (BPPPs), single- and double-strand breaks, and DNA-DNA crosslinks, produced some unexpected findings. Contrary to the situation with living tissues or cells in culture, the predominant UVC-induced damage to DNA in bloodstains appears not to be pyrimidine dimers. Although some evidence for the presence of BPPPs and DNA crosslinks was obtained, the major form of UVC damage causing genetic profile loss appeared to be single-strand breaks. It was not possible, however, to preclude the possibility that a combination of damage types was responsible for the profile loss observed. We demonstrate here that a significant measure of protection against UVC-mediated genetic profile loss in dried biological stain material is afforded by the dehydrated state of the DNA and, to a lesser extent, the DNA cellular milieu.

Evaluation of Common Angling-Induced Sources of Epithelial Damage for Popular Freshwater Sport Fish using Fluorescein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colotelo, Alison HA; Cooke, Steven J.

Angling is a popular recreational activity across the globe and a large proportion of fish captured by anglers are released due to voluntary or mandatory catch-and-release practices. The handling associated with hook removal and return of the fish to their environment can cause physical damage to the epidermal layer of the fish which may affect the condition and survival of released fish. This study investigated possible sources of epithelial damage associated with several different handling methods (i.e. landing net types, interactions with different boat floor surfaces, tournament procedures) commonly used in recreational angling for two popular freshwater sport fish species,more » largemouth bass (Micropterus salmoides) and northern pike (Esox lucius). Epithelial damage was examined using fluorescein, a non-toxic dye, which has been shown to detect latent epithelial damage. Northern pike exhibited extensive epithelial damage after exposure to several of the induced treatments (i.e., interaction with a carpeted surface, knotted nylon net, and line rolling) but relatively little epithelial damage when exposed to others (i.e., knotless rubber nets, smooth boat surfaces, or lip gripping devices). Largemouth bass did not show significant epithelial damage for any of the treatments, with the exception of fish caught in a semi-professional live release tournament. The detection of latent injuries using fluorescein can be an important management tool as it provides visual examples of potential damage that can be caused by different handling methods. Such visualizations can be used to encourage fish friendly angler behaviour and enhance the survival and welfare of released fish. It can also be used to test new products that are intended to or claim to reduce injury to fish that are to be released. Future research should evaluate the relationship between different levels of epithelial damage and mortality across a range of environmental conditions.« less

Study on the spectral characteristics of the damaged rice under brown planthopper, Nilaparvata lugens

NASA Astrophysics Data System (ADS)

Wu, Xiuju; Cheng, Qian

2010-11-01

The spectra of healthy leaves and leaves damaged by the rice brown planthopper (BPH, Nilaparvata lugens) were measured using a Spectroradiometer with spectral range of 350-1050 nm and resolution of 3 nm. The data was analyzed using the method of red edge methods. In the range of 430-530 nm and 560-730cnm, the band depth and slope were calculated. The damage degrees of rice plants caused by the BPH nymphae with different numbers were measured well by the spectral reflectance. The spectral characteristics of damaged rice under brown Planthopper, Nilaparvata lugenswere analyzed, and the reflectance was significantly negatively correlated with the number of BPHs. The red edge slope and edge area of the reflectance also significance correlated with the number of nymphae. The estimation models were constructed to estimate the BPHs using the spectral reflectance at the wavelengths of 550 nm and 760 nm and the red edge index. The results showed that accuracy of the estimation models were 66-81% and the spectral reflectance at R755 was efficient for estimating the number of BPHs.

Free radical development in phacoemulsification cataract surgery.

PubMed

Takahashi, Hiroshi

2005-02-01

Phacoemulsification and aspiration (PEA) has become the most popular cataract surgery, due to the establishment of safe surgical techniques and development of associated instruments. However, corneal endothelial damage still represents a serious complication, as excessive damage can lead to irreversible bullous keratopathy. In addition to causes such as mechanical or heat injuries, free radical formation due to ultrasound has been posited as another cause of corneal endothelium damage in PEA. Ultrasound in aqueous solution induces cavitation, directly causing water molecule disintegration and resulting in the formation of hydroxylradicals, the most potent of the reactive oxygen species. Considering the oxidative insult to endothelial cells caused by free radicals, their presence in the anterior chamber may represent one of the most harmful factors during these procedures. Indeed, some researchers have recently started to evaluate PEA from the perspective of oxidative stress. Conversely, the major ingredient in ophthalmic viscosurgical devices (OVDs), which are indispensable for maintaining the anterior chamber in PEA surgery, is sodium hyaluronate, a known free radical scavenger. OVDs can thus be expected to provide some anti-free radical effect during PEA procedures. In addition, since commercially available OVDs display different properties regarding retention in the anterior chamber during PEA, the anti-free radical effect of OVDs is likely to depend on behavior during irrigation and aspiration. The present study followed standard PEA procedures in an eye model and measured hydroxylradicals in the anterior chamber using electron spin resonance. The kinetics of free radical intensity and effects of several OVDs during clinical PEA were also demonstrated. These studies may be of significance in re-evaluating OVDs as a chemical protectant for corneal endothelium, since the OVD has thus far only been regarded as a physical barrier. In addition, many reports about corneal endothelium damage during PEA have been published, but objective evaluation of various damaging factors has been difficult. The present assay of free radicals in a simulation of clinical PEA offers the first method to quantitatively assess stress on the corneal endothelium.

Protection against oxidative DNA damage and stress in human prostate by glutathione S-transferase P1

PubMed Central

Kanwal, Rajnee; Pandey, Mitali; Bhaskaran, Natarajan; MacLennan, Gregory T; Fu, Pingfu; Ponsky, Lee E; Gupta, Sanjay

2014-01-01

The pi-class glutathione S-transferase (GSTP1) actively protect cells from carcinogens and electrophilic compounds. Loss of GSTP1 expression via promoter hypermethylation is the most common epigenetic alteration observed in human prostate cancer. Silencing of GSTP1 can increase generation of reactive oxygen species (ROS) and DNA damage in cells. In this study we investigated whether loss of GSTP1 contributes to increased DNA damage that may predispose men to a higher risk of prostate cancer. We found significantly elevated (103%; P<0.0001) levels of 8-oxo-2′-deoxogunosine (8-OHdG), an oxidative DNA damage marker, in adenocarcinomas, compared to benign counterparts, which positively correlated (r=0.2) with loss of GSTP1 activity (34%; P<0.0001). Silencing of GSTP1 using siRNA approach in normal human prostate epithelial RWPE1 cells caused increased intracellular production of ROS and higher susceptibility of cells to H2O2-mediated oxidative stress. Additionally, human prostate carcinoma LNCaP cells, which contain a silenced GSTP1 gene, were genetically modified to constitutively express high levels of GSTP1. Induction of GSTP1 activity lowered endogenous ROS levels in LNCaP-pLPCX-GSTP1 cells, and when exposed to H2O2, these cells exhibited significantly reduced production of ROS and 8-OHdG levels, compared to vector control LNCaP-pLPCX cells. Furthermore, exposure of LNCaP cells to green tea polyphenols caused re-expression of GSTP1, which protected the cells from H2O2-mediated DNA damage through decreased ROS production compared to non-exposed cells. These results suggest that loss of GSTP1 expression in human prostate cells, a process that increases their susceptibility to oxidative stress-induced DNA damage, may be an important target for primary prevention of prostate cancer. PMID:22833520

Nanogravimetric and voltammetric DNA-hybridization biosensors for studies of DNA damage by common toxicants and pollutants.

PubMed

Nowicka, Anna M; Kowalczyk, Agata; Stojek, Zbigniew; Hepel, Maria

2010-01-01

Electrochemical and nanogravimetric DNA-hybridization biosensors have been developed for sensing single mismatches in the probe-target ssDNA sequences. The voltammetric transduction was achieved by coupling ferrocene moiety to streptavidin linked to biotinylated tDNA. The mass-related frequency transduction was implemented by immobilizing the sensory pDNA on a gold-coated quartz crystal piezoresonators oscillating in the 10MHz band. The high sensitivity of these sensors enabled us to study DNA damage caused by representative toxicants and environmental pollutants, including Cr(VI) species, common pesticides and herbicides. We have found that the sensor responds rapidly to any damage caused by Cr(VI) species, with more severe DNA damage observed for Cr(2)O(7)(2-) and for CrO(4)(2-) in the presence of H(2)O(2) as compared to CrO(4)(2-) alone. All herbicides and pesticides examined caused DNA damage or structural alterations leading to the double-helix unwinding. Among these compounds, paraoxon-ethyl and atrazine caused the fastest and most severe damage to DNA. The physico-chemical mechanism of damaging interactions between toxicants and DNA has been proposed. The methodology of testing voltammetric and nanogravimetric DNA-hybridization biosensors developed in this work can be employed as a simple protocol to obtain rapid comparative data concerning DNA damage caused by herbicide, pesticides and other toxic pollutants. The DNA-hybridization biosensor can, therefore, be utilized as a rapid screening device for classifying environmental pollutants and to evaluate DNA damage induced by these compounds.

Nucleotide excision repair deficient mouse models and neurological disease

PubMed Central

Niedernhofer, Laura J.

2008-01-01

Nucleotide excision repair (NER) is a highly conserved mechanism to remove helix-distorting DNA base damage. A major substrate for NER is DNA damage caused by environmental genotoxins, most notably ultraviolet radiation. Xeroderma pigmentosum, Cockayne syndrome and trichothiodystrophy are three human diseases caused by inherited defects in NER. The symptoms and severity of these diseases vary dramatically, ranging from profound developmental delay to cancer predisposition and accelerated aging. All three syndromes include neurological disease, indicating an important role for NER in protecting against spontaneous DNA damage as well. To study the pathophysiology caused by DNA damage, numerous mouse models of NER deficiency were generated by knocking-out genes required for NER or knocking-in disease-causing human mutations. This review explores the utility of these mouse models to study neurological disease caused by NER deficiency. PMID:18272436

Karaya gum electrocardiographic electrodes for preterm infants.

PubMed Central

Cartlidge, P H; Rutter, N

1987-01-01

Changes in transepidermal water loss were used to measure skin damage caused by removal of electrocardiograph electrodes in 20 preterm infants. Electrodes secured by conventional adhesive damaged the skin, leading to a potentially dangerous increase in skin permeability. In contrast, those secured by karaya gum caused no skin damage. PMID:3435167

Radiobiological basis of SBRT and SRS.

PubMed

Song, Chang W; Kim, Mi-Sook; Cho, L Chinsoo; Dusenbery, Kathryn; Sperduto, Paul W

2014-08-01

Stereotactic body radiation therapy (SBRT) and stereotactic radiosurgery (SRS) have been demonstrated to be highly effective for a variety of tumors. However, the radiobiological principles of SBRT and SRS have not yet been clearly defined. It is well known that newly formed tumor blood vessels are fragile and extremely sensitive to ionizing radiation. Various lines of evidence indicate that irradiation of tumors with high dose per fraction, i.e. >10 Gy per fraction, not only kills tumor cells but also causes significant damage in tumor vasculatures. Such vascular damage and ensuing deterioration of the intratumor environment then cause ischemic or indirect/secondary tumor cell death within a few days after radiation exposure, indicating that vascular damage plays an important role in the response of tumors to SBRT and SRS. Indications are that the extensive tumor cell death due to the direct effect of radiation on tumor cells and the secondary effect through vascular damage may lead to massive release of tumor-associated antigens and various pro-inflammatory cytokines, thereby triggering an anti-tumor immune response. However, the precise role of immune assault on tumor cells in SBRT and SRS has not yet been clearly defined. The "4 Rs" for conventional fractionated radiotherapy do not include indirect cell death and thus 4 Rs cannot account for the effective tumor control by SBRT and SRS. The linear-quadratic model is for cell death caused by DNA breaks and thus the usefulness of this model for ablative high-dose SBRT and SRS is limited.

Laboratory experiments on dam-break flow of water-sediment mixtures

USDA-ARS?s Scientific Manuscript database

Dams induce sedimentation and store significant amounts of sediment as they age; therefore, dam failures often involve the release of sediment-laden water to the downstream floodplain. In particular, tailings dams, which are constructed to impound mining wastes, can cause devastating damage when the...

Detection of internally bruised blueberries using hyperspectral transmittance imaging

USDA-ARS?s Scientific Manuscript database

The consumption of the blueberries all over the world has been constantly increasing over the past three decades due to its health benefits. The internal bruising damage during harvesting and postharvest handling lower overall quality and cause significant economic losses. The main goal of this st...

Plant-microbe relationship that influences an insect pest of Califronia tree nuts

USDA-ARS?s Scientific Manuscript database

California produces a large portion of the worldwide supply of pistachios. The navel orangeworm is considered a major insect pest of California pistachios, and causes significant damage to pistachio kernels in addition to introducing aflatoxigenic fungi. Despite the development of semiochemical-base...

Lessons from Hurricane Sandy for port resilience.

DOT National Transportation Integrated Search

2013-12-01

New York Harbor was directly in the path of the most damaging part of Hurricane Sandy causing significant impact on many of the : facilities of the Port of New York and New Jersey. The U.S. Coast Guard closed the entire Port to all traffic before the...

SOLID WASTE LEACHING CHEMISTRY AND TESTING: A COMPREHENSIVE APPROACH TO ASSESS FUNDAMENTAL PARAMETERS

EPA Science Inventory

Worldwide, various anthropogenic activities generate hazardous solid wastes that are abundant in heavy metals, which can cause significant damage to the environment and human health. One of the major problems with solid wastes is the generation of large quantities of heavily con...

Impact Behavior of Composite Fan Blade Leading Edge Subcomponent with Thermoplastic Polyurethane Interleave

NASA Technical Reports Server (NTRS)

Miller, Sandi G.; Roberts, Gary D.; Kohlman, Lee W.; Heimann, Paula J.; Pereira, J. Michael; Ruggeri, Charles R.; Martin, Richard E.; McCorkle, Linda S.

2015-01-01

Impact damage tolerance and damage resistance is a critical metric for application of polymer matrix composites where failure caused by impact damage could compromise structural performance and safety. As a result, several materials and/or design approaches to improve impact damage tolerance have been investigated over the past several decades. Many composite toughening methodologies impart a trade-off between increased fracture toughness and compromised in-plane strength and modulus. In large part, mechanical tests to evaluate composite damage tolerance include static methods such as Mode I, Mode II, and mixed mode failures. However, ballistic impact damage resistance does not always correlate with static properties. The intent of this paper is to evaluate the influence of a thermoplastic polyurethane veil interleave on the static and dynamic performance of composite test articles. Static coupon tests included tension, compression, double cantilever beam, and end notch flexure. Measurement of the resistance to ballistic impact damage were made to evaluate the composites response to high speed impact. The interlayer material showed a decrease of in-plane performance with only a moderate improvement to Mode I and Mode II fracture toughness. However, significant benefit to impact damage tolerance was observed through ballistic tests.

Quercetin, a Flavonoid Antioxidant, Ameliorated Procarbazine-Induced Oxidative Damage to Murine Tissues

PubMed Central

Olayinka, Ebenezer Tunde; Ore, Ayokanmi; Adeyemo, Oluwatobi Adewumi; Ola, Olaniyi Solomon; Olotu, Olaoluwa Oluwaseun; Echebiri, Roseline Chinonye

2015-01-01

Procarbazine (PCZ) (indicated in Hodgkin’s disease), is an alkylating agent known to generate free radicals in vivo, while Quercetin (QCT) is a flavonoid antioxidant with proven free radical scavenging capacity. This study investigated the protective effects of QCT on PCZ-induced oxidative damage in the rat. Male Wistar rats (160–180 g) were randomized into five groups (n = 5/group): I (control), II PCZ-treated (2 mg/kg body weight (bw) for seven days); III pre-treated with QCT (20 mg/kg bw) for seven days, followed by PCZ for seven days; IV co-treated with PCZ and QCT for seven days and V administered QCT alone for seven days. PCZ caused a significant increase in plasma total bilirubin, urea, and creatinine when compared with control (P < 0.05). Similarly, plasma activities of alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and γ-glutamyl transferase (γ-GT) were significantly increased in the PCZ-treated group relative to control. Furthermore, PCZ caused a significant decrease in the activities of hepatic superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) as well as levels of ascorbic acid (AA) and glutathione (GSH). This was followed by a significant increase in hepatic malondialdehyde (MDA) content. However, QCT pre-treatment and co-treatment ameliorated the PCZ-induced changes in plasma levels of urea, creatinine, and bilirubin as well as the activities of ALP, AST, ALT, and GGT. QCT also ameliorated hepatic AA and GSH levels and the activities of SOD, CAT, and GST. This all suggests that QCT protected against PCZ-induced oxidative damage in rats. PMID:26783707

Thermal effects in Cs DPAL and alkali cell window damage

NASA Astrophysics Data System (ADS)

Zhdanov, B. V.; Rotondaro, M. D.; Shaffer, M. K.; Knize, R. J.

2016-10-01

Experiments on power scaling of Diode Pumped Alkali Lasers (DPALs) revealed some limiting parasitic effects such as alkali cell windows and gain medium contamination and damage, output power degradation in time and others causing lasing efficiency decrease or even stop lasing1 . These problems can be connected with thermal effects, ionization, chemical interactions between the gain medium components and alkali cells materials. Study of all these and, possibly, other limiting effects and ways to mitigate them is very important for high power DPAL development. In this talk we present results of our experiments on temperature measurements in the gain medium of operating Cs DPAL at different pump power levels in the range from lasing threshold to the levels causing damage of the alkali cell windows. For precise contactless in situ temperature measurements, we used an interferometric technique, developed in our lab2 . In these experiments we demonstrated that damage of the lasing alkali cell starts in the bulk with thermal breakdown of the hydrocarbon buffer gas. The degradation processes start at definite critical temperatures of the gain medium, different for each mixture of buffer gas. At this critical temperature, the hydrocarbon and the excited alkali metal begin to react producing the characteristic black soot and, possibly, some other chemical compounds, which both harm the laser performance and significantly increase the harmful heat deposition within the laser medium. This soot, being highly absorptive, is catastrophically heated to very high temperatures that visually observed as bulk burning. This process quickly spreads to the cell windows and causes their damage. As a result, the whole cell is also contaminated with products of chemical reactions.

Alterations in histone acetylation following exposure to 60Co γ-rays and their relationship with chromosome damage in human lymphoblastoid cells.

PubMed

Tian, Xue-Lei; Lu, Xue; Feng, Jiang-Bin; Cai, Tian-Jing; Li, Shuang; Tian, Mei; Liu, Qing-Jie

2018-05-17

Chromosome damage is related to DNA damage and erroneous repair. It can cause cell dysfunction and ultimately induce carcinogenesis. Histone acetylation is crucial for regulating chromatin structure and DNA damage repair. Ionizing radiation (IR) can alter histone acetylation. However, variations in histone acetylation in response to IR exposure and the relationship between histone acetylation and IR-induced chromosome damage remains unclear. Hence, this study investigated the variation in the total acetylation levels of H3 and H4 in human lymphocytes exposed to 0-2 Gy 60 Co γ-rays. Suberoylanilide hydroxamic acid (SAHA), a histone deacetylase (HDAC) inhibitor, was added to modify the histone acetylation state of irradiated cells. Then, the total acetylation level, enzyme activity, dicentric plus centric rings (dic + r) frequencies, and micronucleus (MN) frequencies of the treated cells were analyzed. Results indicated that the acetylation levels of H3 and H4 significantly decreased at 1 and 24 h, respectively, after radiation exposure. The acetylation levels of H3 and H4 in irradiated groups treated with SAHA were significantly higher than those in irradiated groups that were not treated with SAHA. SAHA treatment inhibited HDAC activity in cells exposed to 0-1 Gy 60 Co γ-rays. SAHA treatment significantly decreased dic + r/cell and MN/cell in cells exposed to 0.5 or 1.0 Gy 60 Co γ-rays relative to that in cells that did not receive SAHA treatment. In conclusion, histone acetylation is significantly affected by IR and is involved in chromosome damage induced by 60 Co γ-radiation.

Acute and subacute effects of the ultrasonic blade and electrosurgery on nerve physiology.

PubMed

Chen, Chaoyang; Kallakuri, Srinivasu; Cavanaugh, John M; Broughton, Duan; Clymer, Jeffrey W

2015-01-01

Ultrasonic blades have been shown to cause less acute electrophysiological damage when applied near nerves than monopolar electrosurgery (ES). This study was performed to determine whether the acute nerve damage observed for ES, as well as the relative lack of damage observed for ultrasonic dissection, extends through a subacute timeframe. Muscle incisions were made in rat with the Harmonic(®) Blade (HB) and ES at a distance of 2 mm from the sciatic nerve. Sham surgery was also performed which consisted of similar exposure of the sciatic nerve without use of an energized device. Electrophysiological function was assessed acutely over a 3-h period, and subacutely after a 7-day survival, by monitoring the sciatic nerve compound action potential (CAP), conduction velocity (CV), von Frey hair (VFH) stimulation force, leukocyte infiltration, and impaired axonal transport via β-amyloid precursor protein (β-APP) immunocytochemistry. During the acute period, ES produced significantly lower CAP and CV, and higher levels of leukocytes and β-APP than sham, whereas the ultrasonic blade was not significantly different from sham, and had significantly lower VFH force than ES. After the subacute survival, ES continued to display significantly lower CAP and CV, and higher levels of leukocytes and β-APP than sham, whereas ultrasonic blade had higher CAP and CV than sham, and lower VFH than ES. This study confirms that incisions made with an ultrasonic blade cause less acute nerve damage than monopolar ES, and are comparable to sham surgery at a distance of 2 mm from the sciatic nerve. The negative effects of electrosurgery extend through at least a 7-day survival period, whereas subacute recovery after application of the ultrasonic blade was comparable to that of sham surgery. For surgical procedures in the vicinity of vital nerves, use of the ultrasonic blade represents a lower risk than ES for both acute and subacute neural trauma.

Endoplasmic Reticulum Stress Mediates Methamphetamine-Induced Blood–Brain Barrier Damage

PubMed Central

Qie, Xiaojuan; Wen, Di; Guo, Hongyan; Xu, Guanjie; Liu, Shuai; Shen, Qianchao; Liu, Yi; Zhang, Wenfang; Cong, Bin; Ma, Chunling

2017-01-01

Methamphetamine (METH) abuse causes serious health problems worldwide, and long-term use of METH disrupts the blood–brain barrier (BBB). Herein, we explored the potential mechanism of endoplasmic reticulum (ER) stress in METH-induced BBB endothelial cell damage in vitro and the therapeutic potential of endoplasmic reticulum stress inhibitors for METH-induced BBB disruption in C57BL/6J mice. Exposure of immortalized BMVEC (bEnd.3) cells to METH significantly decreased cell viability, induced apoptosis, and diminished the tightness of cell monolayers. METH activated ER stress sensor proteins, including PERK, ATF6, and IRE1, and upregulated the pro-apoptotic protein CHOP. The ER stress inhibitors significantly blocked the upregulation of CHOP. Knockdown of CHOP protected bEnd.3 cells from METH-induced cytotoxicity. Furthermore, METH elevated the production of reactive oxygen species (ROS) and induced the dysfunction of mitochondrial characterized by a Bcl2/Bax ratio decrease, mitochondrial membrane potential collapse, and cytochrome c. ER stress release was partially reversed by ROS inhibition, and cytochrome c release was partially blocked by knockdown of CHOP. Finally, PBA significantly attenuated METH-induced sodium fluorescein (NaFluo) and Evans Blue leakage, as well as tight junction protein loss, in C57BL/6J mice. These data suggest that BBB endothelial cell damage was caused by METH-induced endoplasmic reticulum stress, which further induced mitochondrial dysfunction, and that PBA was an effective treatment for METH-induced BBB disruption. PMID:28959203

Early endothelial damage detected by circulating particles in baboons fed a diet high in simple carbohydrates in conjunction with saturated or unsaturated fat.

PubMed

Shi, Qiang; Hodara, Vida; Meng, Qinghe; Voruganti, V Saroja; Rice, Karen; Michalek, Joel E; Comuzzie, Anthony G; VandeBerg, John L

2014-01-01

Studies have shown that high-fat diets cause blood vessel damage, however, assessing pathological effects accurately and efficiently is difficult. In this study, we measured particle levels of static endothelium (CD31+ and CD105+) and activated endothelium (CD62E+, CD54+ and CD106+) in plasma. We determined individual responses to two dietary regimens in two groups of baboons. One group (n = 10), was fed a diet high in simple carbohydrates and saturated fats (the HSF diet) and the other (n = 8) received a diet high in simple carbohydrates and unsaturated fats (the HUF diet). Plasma samples were collected at 0, 3, and 7 weeks. The percentages of CD31+ and CD62E+ particles were elevated at 3 weeks in animals fed either diet, but these elevations were statistically significant only in animals fed the HUF diet. Surprisingly, both percentages and counts of CD31+ particles were significantly lower at week 7 compared to week 0 and 3 in the HSF group. The median absolute counts of CD105+ particles were progressively elevated over time in the HSF group with a significant increase from week 0 to 7; the pattern was somewhat different for the HUF group with significant increase from week 3 to 7. The counts of CD54+ particles exhibited wide variation in both groups during the dietary challenge, while the median counts of CD106+ particles were significantly lower at week 3 than at week 0 and week 7. Endothelial particles exhibited time-dependent changes, suggesting they were behaving as quantifiable surrogates for the early detection of vascular damage caused by dietary factors.

Hydraulic Physical Model of Debris Flow for Malaysia Case Study

NASA Astrophysics Data System (ADS)

Arif Zainol, M. R. R. Mohd; Awahab, M. K.

2018-06-01

In the recent decade, several debris flow events occurred and caused hundreds of deaths, missing or injury and damaged many facilities. In addition to causing significant morphological changes along riverbeds and mountain slopes, these flows are frequently reported to bring about extensive property damage and loss of life. Debris flow phenomena occasionally occur in Malaysia and numbers of death reported cause by this event. In order to investigate the debris flow and its deposition process, experiments were conducted at the School of Civil Engineering Laboratory, Universiti Sains Malaysia. The models consists of three main parts which are water tank, rectangular flume and deposition board. A high speed video camera (HSVC) had been placed nearly downstream of the rectangular flume to capture the movement characteristics of particle grain. From this study, the characteristics of particle routing segregation can be understand clearly, therefore this input will be a very useful information to other researchers for further investigation in terms of knowledge sharing between researchers. Catastrophic cause by debris flow event can be minimized therefore in term of economy losses can be reduce and human life can be safe.

A new survey tool to assess pluvial damage to residential buildings

NASA Astrophysics Data System (ADS)

Rözer, Viktor; Spekkers, Matthieu; ten Veldhuis, Marie-Claire; Kreibich, Heidi

2017-04-01

Pluvial floods have caused severe damage to urban dwellings in Europe and elsewhere in recent years. These type of flood events are caused by storm events with exceptionally high rainfall rates, which lead to inundation of streets and buildings and are commonly associated with a failure of the urban drainage system. Therefore, pluvial floods often happen with little warning and in areas that are not obviously prone to flooding. With a predicted increase in extreme weather events as well as an ongoing urbanization, pluvial flood damage is expected to increase in the future. So far little research was done on the adverse consequences of pluvial floods, as empirical damage data of pluvial flooding is scarce. Therefore, a newly developed survey tool to assess pluvial flood damage as well as the results of a comparison between two international pluvial flood case studies are presented. The questionnaire used in the two study areas was developed with the aim to create a harmonized transnational pluvial flood damage survey that can potentially be extended to other European countries. New indicator variables have been developed to account for different national and regional standards in building structure, early warning, socio-economic data and recovery. The surveys comprise interviews with 510 households in the Münster area (Germany) and 349 households in Amsterdam (the Netherlands), which were affected by the heavy rainfall events on July 28 2014. The respondents were asked more than 80 questions about the damage to their building structure and contents, as well as on topics such as early warning, emergency and precautionary measures, building properties and hazard characteristics. A comparison of the two surveys revealed strong similarities concerning damage reducing effects and the popularity of precautionary measures, besides significant differences between the mean water levels inside the house as well as the median of the building structure and content damage. A comparison between the relative damage contributions for different entry points of water into the house indicates an effect of regional distinctions in building topology on the total damage. The results of this comparison give important insights for the development and transferability of pluvial flood damage models.

Mitochondria in Cancer Energy Metabolism

PubMed Central

2015-01-01

Cancer is a disease characterized by uncontrolled growth. Metabolic demands to sustain rapid proliferation must be compelling since aerobic glycolysis is the first as well as the most commonly shared characteristic of cancer. During the last decade, the significance of metabolic reprogramming of cancer has been at the center of attention. Nonetheless, despite all the knowledge gained on cancer biology, the field is not able to reach agreement on the issue of mitochondria: Are damaged mitochondria the cause for aerobic glycolysis in cancer? Warburg proposed the damaged mitochondria theory over 80 years ago; the field has been testing the theory equally long. In this review, we will discuss alterations in metabolic fluxes of cancer cells, and provide an opinion on the damaged mitochondria theory. PMID:26877834

Magnetic properties of a stainless steel irradiated with 6 MeV Xe ions

NASA Astrophysics Data System (ADS)

Xu, Chaoliang; Liu, Xiangbing; Qian, Wangjie; Li, Yuanfei

2017-11-01

Specimens of austenitic stainless steel were irradiated with 6 MeV Xe ions at room temperature to 2, 7, 15 and 25 dpa. The vibrating sample magnetometer (VSM), grazing incidence X-ray diffraction (GIXRD) and positron annihilation lifetime spectroscopy (PLS) were carried out to analysis the magnetic properties and microstructural variations. The magnetic hysteresis loops indicated that higher irradiation damage causes more significant magnetization phenomenon. The equivalent saturated magnetization Mes and coercive force Hc were obtained from magnetic hysteresis loops. It is indicated that the Mes increases with irradiation damage. While Hc increases first to 2 dpa and then decreases continuously with irradiation damage. The different contributions of irradiation defects and ferrite precipitates on Mes and Hc can explain these phenomena.

Damage of hippocampal neurons in rats with chronic alcoholism.

PubMed

Du, Ailin; Jiang, Hongbo; Xu, Lei; An, Na; Liu, Hui; Li, Yinsheng; Zhang, Ruiling

2014-09-01

Chronic alcoholism can damage the cytoskeleton and aggravate neurological deficits. However, the effect of chronic alcoholism on hippocampal neurons remains unclear. In this study, a model of chronic alcoholism was established in rats that were fed with 6% alcohol for 42 days. Endogenous hydrogen sulfide content and cystathionine-beta-synthase activity in the hippocampus of rats with chronic alcoholism were significantly increased, while F-actin expression was decreased. Hippocampal neurons in rats with chronic alcoholism appeared to have a fuzzy nuclear membrane, mitochondrial edema, and ruptured mitochondrial crista. These findings suggest that chronic alcoholism can cause learning and memory decline in rats, which may be associated with the hydrogen sulfide/cystathionine-beta-synthase system, mitochondrial damage and reduced expression of F-actin.

[Operative treatment strategies for multiple trauma patients : early total care versus damage control].

PubMed

Klüter, T; Lippross, S; Oestern, S; Weuster, M; Seekamp, A

2013-09-01

The treatment of multiple trauma patients is a great challenge for an interdisciplinary team. After preclinical care and subsequent treatment in the emergency room the order of the interventions is prioritized depending of the individual risk stratification. For planning the surgery management it is essential to distinguish between absolutely essential operations to prevent life-threatening situations for the patient and interventions with shiftable indications, depending on the general condition of the patient. All interventions need to be done without causing significant secondary damage to prohibit hyperinflammation and systemic inflammatory response syndrome. The challenge consists in determination of the appropriate treatment at the right point in time. In general the early primary intervention, early total care, is differentiated from the damage control concept.

Development, characterization, and modeling of ballistic impact on composite laminates under compressive pre-stress

NASA Astrophysics Data System (ADS)

Kerr-Anderson, Eric

Structural composite laminates were ballistically impacted while under in-plane compressive pre-stress. Residual properties, damage characterization, and energy absorption were compared to determine synergistic effects of in-plane compressive pre-stress and impact velocity. A fixture was developed to apply in-plane compressive loads up to 30 tons to structural composites during an impact event using a single-stage light-gas gun. Observed failure modes included typical conical delamination, the development of an impact initiated shear crack (IISC), and the shear failure of a pre-stressed composite due to impact. It was observed that the compressive failure threshold quadratically decreased in relation to the impact velocity up to velocities that caused partial penetration. For all laminates impacted at velocities causing partial or full penetration up to 350 ms-1, the failure threshold was consistent and used as an experimental normalization. Samples impacted below 65% of the failure threshold witnessed no significant change in damage morphology or residual properties when compared to typical conical delamination. Samples impacted above 65% of the failure threshold witnessed additional damage in the form of a shear crack extending perpendicular to the applied load from the point of impact. The presence of an IISC reduced the residual properties and even caused failure upon impact at extreme combinations. Four failure envelopes have been established as: transient failure, steady state failure, impact initiated shear crack, and conical damage. Boundaries and empirically based equations for residual compressive strength have been developed for each envelope with relation to two E-glass/vinyl ester laminate systems. Many aspects of pre-stressed impact have been individually examined, but there have been no comprehensive examinations of pre-stressed impact. This research has resulted in the exploration and characterization of compressively pre-stressed damage for impact velocities resulting in reflection, partial penetration, and penetration at pre-stress levels resulting in conical damage, shear cracking, and failure.

Integrated analysis considered mitigation cost, damage cost and adaptation cost in Northeast Asia

NASA Astrophysics Data System (ADS)

Park, J. H.; Lee, D. K.; Kim, H. G.; Sung, S.; Jung, T. Y.

2015-12-01

Various studies show that raising the temperature as well as storms, cold snap, raining and drought caused by climate change. And variety disasters have had a damage to mankind. The world risk report(2012, The Nature Conservancy) and UNU-EHS (the United Nations University Institute for Environment and Human Security) reported that more and more people are exposed to abnormal weather such as floods, drought, earthquakes, typhoons and hurricanes over the world. In particular, the case of Korea, we influenced by various pollutants which are occurred in Northeast Asian countries, China and Japan, due to geographical meteorological characteristics. These contaminants have had a significant impact on air quality with the pollutants generated in Korea. Recently, around the world continued their effort to reduce greenhouse gas and to improve air quality in conjunction with the national or regional development goals priority. China is also working on various efforts in accordance with the international flows to cope with climate change and air pollution. In the future, effect of climate change and air quality in Korea and Northeast Asia will be change greatly according to China's growth and mitigation policies. The purpose of this study is to minimize the damage caused by climate change on the Korean peninsula through an integrated approach taking into account the mitigation and adaptation plan. This study will suggest a climate change strategy at the national level by means of a comprehensive economic analysis of the impacts and mitigation of climate change. In order to quantify the impact and damage cost caused by climate change scenarios in a regional scale, it should be priority variables selected in accordance with impact assessment of climate change. The sectoral impact assessment was carried out on the basis of selected variables and through this, to derive the methodology how to estimate damage cost and adaptation cost. And then, the methodology was applied in Korea. Finally, we build an integrated analysis considered mitigation cost, damage cost, and adaptation cost by climate change

Nondestructive evaluation of incipient decay in hardwood logs

Treesearch

Xiping Wang; Jan Wiedenbeck; Robert J. Ross; John W. Forsman; John R. Erickson; Crystal Pilon; Brian K. Brashaw

2005-01-01

Decay can cause significant damage to high-value hardwood timber. New nondestructive evaluation (NDE) technologies are urgently needed to effectively detect incipient decay in hardwood timber at the earliest possible stage. Currently, the primary means of inspecting timber relies on visual assessment criteria. When visual inspections are used exclusively, they provide...

Adapting the CROPGRO cotton model to simulate cotton biomass and yield under southern root-knot nematode parasitism

USDA-ARS?s Scientific Manuscript database

Cotton (Gossypium hirsutum L.) yield losses by southern root-knot nematode [Meloidogyne incognita (Kofoid & White) Chitwood] (RKN) are usually estimated after significant damage has been caused. However, estimation of potential yield reduction before planting is possible by using crop simulation mod...

The mitogenome of the brown pod-sucking bug Clavigralla tomentosicollis (Hemiptera: Coreidae)

USDA-ARS?s Scientific Manuscript database

Brown pod-sucking bug, Clavigralla tomentosicollis Stäl (Hemiptera: Coreidae), causes significant damage to cultivated cowpea, Vigna unguiculata Walp, a staple crop in sub-Saharan Africa. C. tomentosicollis pierce and suck sap from cowpea pods, resulting in reduced grain yield and quality. The compl...

Olfactory and visual responses of the long-legged chafer hoplia spectabilis medvedev (Coleoptera: Scarabaeidae) in Qinghai province, China

USDA-ARS?s Scientific Manuscript database

The long-legged chafer, Hoplia spectabilis Medvedev (Coleoptera: Scarabaeidae), has recently been recorded in outbreak numbers in pastureland of Qinghai province, China. It is causing significant damage to several species of woody shrubs, especially Hippophae neurocarpa Liu and Ho (Elaeagnaceae), D...

A Role for Intercept Traps in the Ambrosia Beetle (Coleoptera: Curculionidae: Scolytinae) IPM Strategy at Ornamental Nurseries

USDA-ARS?s Scientific Manuscript database

Invasive ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) cause significant damage to ornamental nursery tree crops throughout the Eastern U. S. Depending on surrounding habitat, some nurseries can undergo large influxes of ambrosia beetles from the forest to susceptible nursery stock. Eth...

A COMPREHENSIVE APPROACH TO IDENTIFY AND QUANTIFY FUNDAMENTAL PARAMETERS THAT INFLUENCE METAL LEACHING CHEMISTRY IN LANDFILLS SYSTEMS (PRESENTATION)

EPA Science Inventory

Various anthropogenic activities generate hazardous solid wastes that are affluent in heavy metals, which can cause significant damage to the environment and human health. Heavy metals/metalloids can exist in multiple oxidation states, and can undergo oxidation or reduction when ...

A COMPREHENSIVE APPROACH TO IDENTIFY AND QUANTIFY FUNDAMENTAL PARAMETERS THAT INFLUENCE METAL LEACHING CHEMISTRY IN LANDFILLS SYSTEMS (ABSTRACT)

EPA Science Inventory

Various anthropogenic activities generate hazardous solid wastes that are affluent in heavy metals, which can cause significant damage to the environment and human health. Heavy metals/metalloids can exist in multiple oxidation states, and can undergo oxidation or reduction when ...

2015 nationwide survey revealed Barley stripe mosaic virus in Korean barley fields

USDA-ARS?s Scientific Manuscript database

A seed-transmitted virus has consistently caused significant economic damage to barley crops in Korea in recent years, and may be increasing because many farmers save seed for replanting. Because some barley seed is imported, there is the potential for introduction of new seed-transmitted viruses, c...

Controlling Sirex noctilio in North America: a new paradigm

Treesearch

Nathan M. Schiff; A. Dan Wilson

2007-01-01

The Sirex noctilio woodwasp, a major pest of North American pines in southern hemisphere countries, recently has entered North America, and become established in the northeast. The spread of Sirex noctilio is expected to be rapid. If unchecked it will likely cause significant economic damage to paper and timber industries...

EFFECT OF LIQUID TO SOLID RATIO ON LEACHING OF METALS FROM MINERAL PROCESSING WASTE

EPA Science Inventory

Various anthropogenic activities generate hazardous solid wastes that are affluent in heavy metals, which can cause significant damage to the environment an human health. A mineral processing waste was used to study the effect of liquid to solid ratio (L/S) on the leaching behav...

Oxidative DNA damage induced by a hydroperoxide derivative of cyclophosphamide.

PubMed

Murata, Mariko; Suzuki, Toshinari; Midorikawa, Kaoru; Oikawa, Shinji; Kawanishi, Shosuke

2004-09-15

Interstrand DNA cross-linking has been considered to be the primary action mechanism of cyclophosphamide (CP) and its hydroperoxide derivative, 4-hydroperoxycyclophosphamide (4-HC). To clarify the mechanism of anti-tumor effects by 4-HC, we investigated DNA damage in a human leukemia cell line, HL-60, and its H(2)O(2)-resistant clone HP100. Apoptosis DNA ladder formation was detected in HL-60 cells treated with 4-HC, whereas it was not observed in HP100 cells. 4-HC significantly increased 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation, a marker of oxidative DNA damage, in HL-60 cells. On the other hand, CP did not significantly induce 8-oxodG formation and apoptosis in HL-60 cells under the same conditions as did 4-HC. Using (32)P-labeled DNA fragments from the human p53 tumor suppressor gene, 4-HC was found to cause Cu(II)-mediated oxidative DNA damage, but CP did not. Catalase inhibited 4-HC-induced DNA damage, including 8-oxodG formation, suggesting the involvement of H(2)O(2). The generation of H(2)O(2) during 4-HC degradation was ascertained by procedures using scopoletin and potassium iodide. We conclude that, in addition to DNA cross-linking, oxidative DNA damage through H(2)O(2) generation may participate in the anti-tumor effects of 4-HC.

Loss‐of‐function mutation of rice SLAC7 decreases chloroplast stability and induces a photoprotection mechanism in rice

PubMed Central

Fan, Xiaolei; Wu, Jiemin; Chen, Taiyu; Tie, Weiwei; Chen, Hao; Zhou, Fei

2015-01-01

Abstract Plants absorb sunlight to power the photochemical reactions of photosynthesis, which can potentially damage the photosynthetic machinery. However, the mechanism that protects chloroplasts from the damage remains unclear. In this work, we demonstrated that rice (Oryza sativa L.) SLAC7 is a generally expressed membrane protein. Loss‐of‐function of SLAC7 caused continuous damage to the chloroplasts of mutant leaves under normal light conditions. Ion leakage indicators related to leaf damage such as H2O2 and abscisic acid levels were significantly higher in slac7‐1 than in the wild type. Consistently, the photosynthesis efficiency and Fv/Fm ratio of slac7‐1 were significantly decreased (similar to photoinhibition). In response to chloroplast damage, slac7‐1 altered its leaf morphology (curled or fused leaf) by the synergy between plant hormones and transcriptional factors to decrease the absorption of light, suggesting that a photoprotection mechanism for chloroplast damage was activated in slac7‐1. When grown in dark conditions, slac7‐1 displayed a normal phenotype. SLAC7 under the control of the AtSLAC1 promoter could partially complement the phenotypes of Arabidopsis slac1 mutants, indicating a partial conservation of SLAC protein functions. These results suggest that SLAC7 is essential for maintaining the chloroplast stability in rice. PMID:25739330

Oxidative stress and genetic damage among workers exposed primarily to organophosphate and pyrethroid pesticides.

PubMed

Zepeda-Arce, Rigoberto; Rojas-García, Aurora Elizabeth; Benitez-Trinidad, Alma; Herrera-Moreno, José Francisco; Medina-Díaz, Irma Martha; Barrón-Vivanco, Briscia S; Villegas, Germán Pier; Hernández-Ochoa, Isabel; Sólis Heredia, María de Jesús; Bernal-Hernández, Yael Y

2017-06-01

The indiscriminate use of pesticides in agriculture and public health campaigns has been associated with an increase of oxidative stress and DNA damage, resulting in health outcomes. Some defense mechanisms against free radical-induced oxidative damage include the antioxidant enzyme systems. The aim of this study was to determine the levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and the relationship of antioxidant enzyme levels with DNA damage among sprayers (workers) occupationally exposed to pesticides. The determinations of MDA and antioxidant enzymes were performed spectrophotometrically. The genotoxic effects were evaluated using the comet assay. The results showed a marginally significant decrease in SOD and CAT activities in the high exposure group compared to the control group. For MDA, statistically significant differences were found among people working long term vs. those working temporarily (P = 0.02) as sprayers. In the moderate exposure group, a positive correlation was observed between MDA levels and GPx activity. In the high exposure group, a negative correlation was observed between GR and CAT activities, and between MDA levels and GPx activities. Furthermore, in the high exposure group, a positive correlation between DNA damage parameters and MDA levels was observed. The results suggest an important role of antioxidant enzymes for the protection of DNA damage caused by occupational exposure to pesticides. © 2017 Wiley Periodicals, Inc.

Gum acacia mitigates genetic damage in adenine-induced chronic renal failure in rats.

PubMed

Ali, B H; Al Balushi, K; Al-Husseini, I; Mandel, P; Nemmar, A; Schupp, N; Ribeiro, D A

2015-12-01

Subjects with chronic renal failure (CRF) exhibit oxidative genome damage, which may predispose to carcinogenesis, and Gum acacia (GumA) ameliorates this condition in humans and animals. We evaluated here renal DNA damage and urinary excretion of four nucleic acid oxidation adducts namely 8-oxoguanine (8-oxoGua), 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), 8-oxoguanosine (8-oxoGuo) and 8-hydroxy-2-deoxyguanisone (8-OHdg) in rats with adenine (ADE)-induced CRF with and without GumA treatment. Twenty-four rats were divided into four equal groups and treated for 4 weeks. The first group was given normal food and water (control). The second group was given normal food and GumA (15% w/v) in drinking water. The third group was fed powder diet containing adenine (ADE) (0·75% w/w in feed). The fourth group was fed like in the third group, plus GumA in drinking water (15%, w/v). ADE feeding induced CRF (as measured by several physiological, biochemical and histological indices) and also caused a significant genetic damage and significant decreases in urinary 8-oxo Gua and 8-oxoGuo, but not in the other nucleic acids. However, concomitant GumA treatment reduced the level of genetic damage in kidney cells as detected by Comet assay and significantly reversed the effect of adenine on urinary 8-oxoGuo. Treatment with GumA is able to mitigate genetic damage in renal tissues of rats with ADE-induced CRF. © 2015 Stichting European Society for Clinical Investigation Journal Foundation.

High doses of alcohol during pregnancy cause DNA damages in osteoblasts of newborns rats.

PubMed

Carvalho, Isabel Chaves Silva; Dutra, Tamires Pereira; Andrade, Dennia Perez De; Balducci, Ivan; Pacheco-Soares, Cristina; Rocha, Rosilene Fernandes da

2016-02-01

Alcohol exerts teratogenic effects and its consumption during pregnancy can cause deficit of bone development. The aim of the current study was to evaluate the genotoxic effects of prenatal exposure to ethanol on newborn rat osteoblasts. Wistar rats were initially divided into two groups: Ethanol group which received Ethanol 20% V/V in liquid diet and solid diet ad libitum, and Control group, which received solid diet and water ad libitum. Each group received a specific diet for 8 weeks before breeding and throughout three weeks of gestation and the treatment was finished on the day the pups were killed. On the fifth day of life, the pups from each group were killed for removal of the calvaria and isolation of osteogenic cells by sequential enzymatic digestion. The cells were cultured for a maximum period of 14 days. The detection of genotoxic effects of alcohol was investigated by the comet and the micronucleus assay. Micronucleus and comet assay showed significant increases in DNA damage at 7 days in Ethanol group (p = 0.0302, p = 0.0446, respectively). However, at 14 days both assay showed no significant difference between the groups (p = 0.6194, p = 0.8326, respectively). Our results showed that prenatal exposure to ethanol induced DNA damage in osteoblasts, as shown by micronucleus formation and higher percentage of DNA in the comet tail. It can be concluded that prenatal exposure to ethanol damages osteoblast DNA in newborns exposed to high doses of ethanol during pregnancy, suggesting that prenatal ethanol consumption has a direct effect on fetal osteoblasts. © 2015 Wiley Periodicals, Inc.

A Probabilistic Typhoon Risk Model for Vietnam

NASA Astrophysics Data System (ADS)

Haseemkunju, A.; Smith, D. F.; Brolley, J. M.

2017-12-01

Annually, the coastal Provinces of low-lying Mekong River delta region in the southwest to the Red River Delta region in Northern Vietnam is exposed to severe wind and flood risk from landfalling typhoons. On average, about two to three tropical cyclones with a maximum sustained wind speed of >=34 knots make landfall along the Vietnam coast. Recently, Typhoon Wutip (2013) crossed Central Vietnam as a category 2 typhoon causing significant damage to properties. As tropical cyclone risk is expected to increase with increase in exposure and population growth along the coastal Provinces of Vietnam, insurance/reinsurance, and capital markets need a comprehensive probabilistic model to assess typhoon risk in Vietnam. In 2017, CoreLogic has expanded the geographical coverage of its basin-wide Western North Pacific probabilistic typhoon risk model to estimate the economic and insured losses from landfalling and by-passing tropical cyclones in Vietnam. The updated model is based on 71 years (1945-2015) of typhoon best-track data and 10,000 years of a basin-wide simulated stochastic tracks covering eight countries including Vietnam. The model is capable of estimating damage from wind, storm surge and rainfall flooding using vulnerability models, which relate typhoon hazard to building damageability. The hazard and loss models are validated against past historical typhoons affecting Vietnam. Notable typhoons causing significant damage in Vietnam are Lola (1993), Frankie (1996), Xangsane (2006), and Ketsana (2009). The central and northern coastal provinces of Vietnam are more vulnerable to wind and flood hazard, while typhoon risk in the southern provinces are relatively low.

DNA damage and genetic methylation changes caused by Cd in Arabidopsis thaliana seedlings.

PubMed

Li, Zhaoling; Liu, Zhihong; Chen, Ruijuan; Li, Xiaojun; Tai, Peidong; Gong, Zongqiang; Jia, Chunyun; Liu, Wan

2015-09-01

Amplified fragment length polymorphism (AFLP) and methylation-sensitive amplification polymorphism (MASP) techniques are sensitive to deoxyribonucleic acid (DNA) damage and genetic methylation, respectively. Using these 2 techniques, Arabidopsis thaliana cultured with 0 mg/L (control), 0.5 mg/L, 1.5 mg/L, and 5.0 mg/L Cd(2+) for 16 d was used to analyze the DNA damage and methylation changes as a result of cadmium (Cd). The DNA was amplified by 14 AFLP primer pairs and 13 MSAP primer combinations. In the AFLP experiment, 62 polymorphic sites were found in the patterns of 11 primer combinations and a total of 1116 fragments were obtained in these patterns. There were no polymorphic bands in the remaining 3 pairs. The proportions of polymorphic sites in the 0.5-mg/L Cd(2+) and 5.0-mg/L Cd(2+) treatments were significantly different. Seven polymorphic fragments were then separated and successfully sequenced, yielding 6 nucleobase substitutions and 1 nucleobase deletion. Similarly, in the MSAP experiment, the MSAP% and number of demethylated-type bands were unchanged after Cd treatment, but the number of methylated-type bands was increased significantly in the 5.0-mg/L Cd(2+) treatment group, a finding that may be associated with the AFLP results. The polymorphic bands were also sequenced and the functions of their homologous genes were determined. The DNA damage and methylation changes may be the primary cause of certain pathology changes as a result of Cd uptake in plants. © 2015 SETAC.

Agmatine protects against cell damage induced by NMDA and glutamate in cultured hippocampal neurons

PubMed Central

Wang, Wei-Ping; Iyo, Abiye H.; Miguel-Hidalgo, Javier; Regunathan, Soundar; Zhu, Meng-Yang

2010-01-01

Agmatine is a polyamine and has been considered as a novel neurotransmitter or neuromodulator in the central nervous system. In the present study, the neuroprotective effect of agmatine against cell damage caused by N-methyl-d-aspartate (NMDA) and glutamate was investigated in cultured rat hippocampal neurons. Lactate dehydrogenase (LDH) activity assay, β-tubulin III immunocytochemical staining and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick end-labeling (TUNEL) assay were conducted to detect cell damage. Exposure of 12-day neuronal cultures of rat hippocampus to NMDA or glutamate for 1 h caused a concentration-dependent neurotoxicity, as indicated by the significant increase in released LDH activities. Addition of 100 µM agmatine into media ablated the neurotoxicity induced by NMDA or glutamate, an effect also produced by the specific NMDA receptor antagonist dizocilpine hydrogen maleate (MK801). Arcaine, an analog of agmatine with similar structure as agmatine, fully prevented the NMDA- or glutamate-induced neuronal damage. Spermine and putrescine, the endogenous polyamine and metabolic products of agmatine without the guanidine moiety of agmatine, failed to show this effect, indicating a structural relevance for this neuroprotection. Immunocytochemical staining and TUNEL assay confirmed the findings in the LDH measurement. That is, agmatine and MK801 markedly attenuated NMDA-induced neuronal death and significantly reduced TUNEL-positive cell numbers induced by exposure of cultured hippocampal neurons to NMDA. Taken together, these results demonstrate that agmatine can protect cultured hippocampal neurons from NMDA- or glutamate-induced excitotoxicity, through a possible blockade of the NMDA receptor channels or a potential anti-apoptotic property. PMID:16546145

Time Course and Association of Functional and Biochemical Markers in Severe Semitendinosus Damage Following Intensive Eccentric Leg Curls: Differences between and within Subjects.

PubMed

Carmona, Gerard; Mendiguchía, Jurdan; Alomar, Xavier; Padullés, Josep M; Serrano, David; Nescolarde, Lexa; Rodas, Gil; Cussó, Roser; Balius, Ramón; Cadefau, Joan A

2018-01-01

Purpose: To investigate the extent and evolution of hamstring muscle damage caused by an intensive bout of eccentric leg curls (ELCs) by (1) assessing the time course and association of different indirect markers of muscle damage such as changes in the force-generating capacity (FGC), functional magnetic resonance (fMRI), and serum muscle enzyme levels and (2) analyzing differences in the degree of hamstring muscle damage between and within subjects (limb-to-limb comparison). Methods: Thirteen male participants performed six sets of 10 repetitions of an ELC with each leg. Before and at regular intervals over 7 days after the exercise, FGC was measured with maximal isometric voluntary contraction (MVC). Serum enzyme levels, fMRI transverse relaxation time (T2) and perceived muscle soreness were also assessed and compared against the FGC. Results: Two groups of subjects were identified according to the extent of hamstring muscle damage based on decreased FGC and increased serum enzyme levels: high responders ( n = 10, severe muscle damage) and moderate responders ( n = 3, moderate muscle damage). In the high responders, fMRI T2 analysis revealed that the semitendinosus (ST) muscle suffered severe damage in the three regions measured (proximal, middle, and distal). The biceps femoris short head (BFsh) muscle was also damaged and there were significant differences in the FGC within subjects in the high responders. Conclusion: FGC and serum enzyme levels measured in 10 of the subjects from the sample were consistent with severe muscle damage. However, the results showed a wide range of peak MVC reductions, reflecting different degrees of damage between subjects (high and moderate responders). fMRI analysis confirmed that the ST was the hamstring muscle most damaged by ELCs, with uniform T2 changes across all the measured sections of this muscle. During intensive ELCs, the ST muscle could suffer an anomalous recruitment pattern due to fatigue and damage, placing an excessive load on the BFsh and causing it to perform a synergistic compensation that leads to structural damage. Finally, T2 and MVC values did not correlate for the leg with the smaller FGC decrease in the hamstring muscles, suggesting that long-lasting increases in T2 signals after FGC markers have returned to baseline values might indicate an adaptive process rather than damage.

Time Course and Association of Functional and Biochemical Markers in Severe Semitendinosus Damage Following Intensive Eccentric Leg Curls: Differences between and within Subjects

PubMed Central

Carmona, Gerard; Mendiguchía, Jurdan; Alomar, Xavier; Padullés, Josep M.; Serrano, David; Nescolarde, Lexa; Rodas, Gil; Cussó, Roser; Balius, Ramón; Cadefau, Joan A.

2018-01-01

Purpose: To investigate the extent and evolution of hamstring muscle damage caused by an intensive bout of eccentric leg curls (ELCs) by (1) assessing the time course and association of different indirect markers of muscle damage such as changes in the force-generating capacity (FGC), functional magnetic resonance (fMRI), and serum muscle enzyme levels and (2) analyzing differences in the degree of hamstring muscle damage between and within subjects (limb-to-limb comparison). Methods: Thirteen male participants performed six sets of 10 repetitions of an ELC with each leg. Before and at regular intervals over 7 days after the exercise, FGC was measured with maximal isometric voluntary contraction (MVC). Serum enzyme levels, fMRI transverse relaxation time (T2) and perceived muscle soreness were also assessed and compared against the FGC. Results: Two groups of subjects were identified according to the extent of hamstring muscle damage based on decreased FGC and increased serum enzyme levels: high responders (n = 10, severe muscle damage) and moderate responders (n = 3, moderate muscle damage). In the high responders, fMRI T2 analysis revealed that the semitendinosus (ST) muscle suffered severe damage in the three regions measured (proximal, middle, and distal). The biceps femoris short head (BFsh) muscle was also damaged and there were significant differences in the FGC within subjects in the high responders. Conclusion: FGC and serum enzyme levels measured in 10 of the subjects from the sample were consistent with severe muscle damage. However, the results showed a wide range of peak MVC reductions, reflecting different degrees of damage between subjects (high and moderate responders). fMRI analysis confirmed that the ST was the hamstring muscle most damaged by ELCs, with uniform T2 changes across all the measured sections of this muscle. During intensive ELCs, the ST muscle could suffer an anomalous recruitment pattern due to fatigue and damage, placing an excessive load on the BFsh and causing it to perform a synergistic compensation that leads to structural damage. Finally, T2 and MVC values did not correlate for the leg with the smaller FGC decrease in the hamstring muscles, suggesting that long-lasting increases in T2 signals after FGC markers have returned to baseline values might indicate an adaptive process rather than damage. PMID:29467666

Delayed Onset Muscle Soreness After Inspiratory Threshold Loading in Healthy Adults

PubMed Central

Mathur, Sunita; Sheel, A. William; Road, Jeremy D.; Reid, W. Darlene

2010-01-01

Purpose: Skeletal muscle damage occurs following high-intensity or unaccustomed exercise; however, it is difficult to monitor damage to the respiratory muscles, particularly in humans. The aim of this study was to use clinical measures to investigate the presence of skeletal muscle damage in the inspiratory muscles. Methods: Ten healthy subjects underwent 60 minutes of voluntary inspiratory threshold loading (ITL) at 70% of maximal inspiratory pressure. Maximal inspiratory and expiratory mouth pressures, delayed onset muscle soreness on a visual analogue scale and plasma creatine kinase were measured prior to ITL, and at repeated time points after ITL (4, 24 and 48 hours post-ITL). Results: Delayed onset muscle soreness was present in all subjects 24 hours following ITL (intensity = 22 ± 6 mm; significantly higher than baseline p = 0.02). Muscle soreness was reported primarily in the anterior neck region, and was correlated to the amount of work done by the inspiratory muscles during ITL (r = 0.72, p = 0.02). However, no significant change was observed in maximal inspiratory or expiratory pressures or creatine kinase. Conclusions: These findings suggest that an intense bout of ITL results in muscle soreness primarily in the accessory muscles of inspiration, however, may be insufficient to cause significant muscle damage in healthy adults. PMID:20467514

Clinical effects of the use of a bipolar vessel sealing device for soft palate resection and tonsillectomy in dogs, with histological assessment of resected tonsillar tissue.

PubMed

Cook, D A; Moses, P A; Mackie, J T

2015-12-01

To investigate whether soft palate resection and tonsillectomy with a bipolar vessel sealing device (BVSD) improves clinical respiratory score. To document histopathological changes to tonsillar tissue following removal with a BVSD. Case series of 22 dogs with clinical signs of upper respiratory obstruction related to brachycephalic airway syndrome. Soft palate and tonsils were removed using a BVSD. Alarplasty and saccullectomy were also performed if indicated. A clinical respiratory score was assigned preoperatively, 24-h postoperatively and 5 weeks postoperatively. Excised tonsillar samples were measured and then assessed histologically for depth of tissue damage deemed to be caused by the device. Depth of tissue damage was compared between two power settings of the device. Soft palate resection and tonsillectomy with a BVSD lead to a significant improvement in respiratory scores following surgery. Depth of tissue damage was significantly less for power setting 1 compared with power setting 2. Using power setting 1, median calculated depth of tonsillar tissue damage was 3.4 mm (range 1.2-8.0). One dog experienced major complications. Soft palate resection and tonsillectomy with a BVSD led to significant improvement in clinical respiratory score. © 2015 Australian Veterinary Association.

Protective effect of alprazolam against sleep deprivation-induced behavior alterations and oxidative damage in mice.

PubMed

Singh, Anant; Kumar, Anil

2008-04-01

Sleep deprivation is considered as a risk factor for various diseases. Sleep deprivation leads to behavioral, hormonal, neurochemical and biochemical alterations in the animals. The present study was designed to explore the possible involvement of GABAergic mechanism in protective effect of alprazolam against 72h sleep deprivation-induced behavior alterations and oxidative damage in mice. In the present study, sleep deprivation caused anxiety-like behavior, weight loss, impaired ambulatory movements and oxidative damage as indicated by increase in lipid peroxidation, nitrite level and depletion of reduced glutathione and catalase activity in sleep-deprived mice brain. Treatment with alprazolam (0.25 and 0.5 mg/kg, ip) significantly improved behavioral alterations. Biochemically, alprazolam treatment significantly restored depleted reduced glutathione, catalase activity, reversed raised lipid peroxidation and nitrite level. Combination of flumazenil (0.5 mg/kg) and picrotoxin (0.5 mg/kg) with lower dose of alprazolam (0.25mg/kg) significantly antagonized protective effect of alprazolam. However, combination of muscimol (0.05 mg/kg) with alprazolam (0.25 mg/kg, ip) potentiated protective effect of alprazolam. On the basis of these results, it might be suggested that alprazolam might produce protective effect by involving GABAergic system against sleep deprivation-induced behavior alterations and related oxidative damage.

Candida parapsilosis Protects Premature Intestinal Epithelial Cells from Invasion and Damage by Candida albicans

PubMed Central

Gonia, Sara; Archambault, Linda; Shevik, Margaret; Altendahl, Marie; Fellows, Emily; Bliss, Joseph M.; Wheeler, Robert T.; Gale, Cheryl A.

2017-01-01

Candida is a leading cause of late-onset sepsis in premature infants and is thought to invade the host via immature or damaged epithelial barriers. We previously showed that the hyphal form of Candida albicans invades and causes damage to premature intestinal epithelial cells (pIECs), whereas the non-hyphal Candida parapsilosis, also a fungal pathogen of neonates, has less invasion and damage abilities. In this study, we investigated the potential for C. parapsilosis to modulate pathogenic interactions of C. albicans with the premature intestine. While a mixed infection with two fungal pathogens may be expected to result in additive or synergistic damage to pIECs, we instead found that C. parapsilosis was able to protect pIECs from invasion and damage by C. albicans. C. albicans-induced pIEC damage was reduced to a similar extent by multiple different C. parapsilosis strains, but strains differed in their ability to inhibit C. albicans invasion of pIECs, with the inhibitory activity correlating with their adhesiveness for C. albicans and epithelial cells. C. parapsilosis cell-free culture fractions were also able to significantly reduce C. albicans adhesion and damage to pIECs. Furthermore, coadministration of C. parapsilosis cell-free fractions with C. albicans was associated with decreased infection and mortality in zebrafish. These results indicate that C. parapsilosis is able to reduce invasion, damage, and virulence functions of C. albicans. Additionally, the results with cellular and cell-free fractions of yeast cultures suggest that inhibition of pathogenic interactions between C. albicans and host cells by C. parapsilosis occurs via secreted molecules as well as by physical contact with the C. parapsilosis cell surface. We propose that non-invasive commensals can be used to inhibit virulence features of pathogens and deserve further study as a non-pharmacological strategy to protect the fragile epithelial barriers of premature infants. PMID:28382297

A prediction and damage assessment model for snowmelt flood events in middle and high latitudes Region

NASA Astrophysics Data System (ADS)

Qiao, C.; Huang, Q.; Chen, T.; Zhang, X.

2017-12-01

In the context of global warming, the snowmelt flood events in the mountainous area of the middle and high latitudes are increasingly frequent and create severe casualties and property damages. Carrying out the prediction and risk assessment of the snowmelt flood is of great importance in the water resources management, the flood warning and prevention. Based on the remote sensing and GIS techniques, the relationships of the variables influencing the snowmelt flood such as the snow area, the snow depth, the air temperature, the precipitation, the land topography and land covers are analyzed and a prediction and damage assessment model for snowmelt floods is developed. This model analyzes and predicts the flood submerging area, flood depth, flood grade, and the damages of different underlying surfaces in the study area in a given time period based on the estimation of snowmelt amount, the snowmelt runoff, the direction and velocity of the flood. Then it was used to predict a snowmelt flood event in the Ertis River Basin in northern Xinjiang, China, during March and June, 2005 and to assess its damages including the damages of roads, transmission lines, settlements caused by the floods and the possible landslides using the hydrological and meteorological data, snow parameter data, DEM data and land use data. A comparison was made between the prediction results from this model and observation data including the flood measurement and its disaster loss data, which suggests that this model performs well in predicting the strength and impact area of snowmelt flood and its damage assessment. This model will be helpful for the prediction and damage assessment of snowmelt flood events in the mountainous area in the middle and high latitudes in spring, which has great social and economic significance because it provides a relatively reliable method for snowmelt flood prediction and reduces the possible damages caused by snowmelt floods.

A comparative survey of the impacts of extreme rainfall in two international case studies

NASA Astrophysics Data System (ADS)

Spekkers, Matthieu; Rözer, Viktor; Thieken, Annegret; ten Veldhuis, Marie-Claire; Kreibich, Heidi

2017-08-01

Flooding is assessed as the most important natural hazard in Europe, causing thousands of deaths, affecting millions of people and accounting for large economic losses in the past decade. Little is known about the damage processes associated with extreme rainfall in cities, due to a lack of accurate, comparable and consistent damage data. The objective of this study is to investigate the impacts of extreme rainfall on residential buildings and how affected households coped with these impacts in terms of precautionary and emergency actions. Analyses are based on a unique dataset of damage characteristics and a wide range of potential damage explaining variables at the household level, collected through computer-aided telephone interviews (CATI) and an online survey. Exploratory data analyses based on a total of 859 completed questionnaires in the cities of Münster (Germany) and Amsterdam (the Netherlands) revealed that the uptake of emergency measures is related to characteristics of the hazardous event. In case of high water levels, more efforts are made to reduce damage, while emergency response that aims to prevent damage is less likely to be effective. The difference in magnitude of the events in Münster and Amsterdam, in terms of rainfall intensity and water depth, is probably also the most important cause for the differences between the cities in terms of the suffered financial losses. Factors that significantly contributed to damage in at least one of the case studies are water contamination, the presence of a basement in the building and people's awareness of the upcoming event. Moreover, this study confirms conclusions by previous studies that people's experience with damaging events positively correlates with precautionary behaviour. For improving future damage data acquisition, we recommend the inclusion of cell phones in a CATI survey to avoid biased sampling towards certain age groups.

Research on Damage Identification of Bridge Based on Digital Image Measurement

NASA Astrophysics Data System (ADS)

Liang, Yingjing; Huan, Shi; Tao, Weijun

2017-12-01

In recent years, the number of the damage bridge due to excessive deformation gradually increased, which caused significant property damage and casualties. Hence health monitoring and the damage detection of the bridge structure based on the deflection measurement are particularly important. The current conventional deflection measurement methods, such as total station, connected pipe, GPS, etc., have many shortcomings as low efficiency, heavy workload, low degree of automation, operating frequency and working time constrained. GPS has a low accuracy in the vertical displacement measurement and cannot meet the dynamic measured requirements of the current bridge engineering. This paper presents a bridge health monitoring and damage detection technology based on digital image measurement method in which the measurement accuracy is sub-millimeter level and can achieve the 24-hour automatic non-destructive monitoring for the deflection. It can be concluded from this paper that it is feasible to use digital image measurement method for identification of the damage in the bridge structure, because it has been validated by the theoretical analysis, the laboratory model and the application of the real bridge.

Protection against renal ischemia-reperfusion injury in vivo by the mitochondria targeted antioxidant MitoQ.

PubMed

Dare, Anna J; Bolton, Eleanor A; Pettigrew, Gavin J; Bradley, J Andrew; Saeb-Parsy, Kourosh; Murphy, Michael P

2015-08-01

Ischemia-reperfusion (IR) injury to the kidney occurs in a range of clinically important scenarios including hypotension, sepsis and in surgical procedures such as cardiac bypass surgery and kidney transplantation, leading to acute kidney injury (AKI). Mitochondrial oxidative damage is a significant contributor to the early phases of IR injury and may initiate a damaging inflammatory response. Here we assessed whether the mitochondria targeted antioxidant MitoQ could decrease oxidative damage during IR injury and thereby protect kidney function. To do this we exposed kidneys in mice to in vivo ischemia by bilaterally occluding the renal vessels followed by reperfusion for up to 24h. This caused renal dysfunction, measured by decreased creatinine clearance, and increased markers of oxidative damage. Administering MitoQ to the mice intravenously 15 min prior to ischemia protected the kidney from damage and dysfunction. These data indicate that mitochondrial oxidative damage contributes to kidney IR injury and that mitochondria targeted antioxidants such as MitoQ are potential therapies for renal dysfunction due to IR injury. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Protection against renal ischemia–reperfusion injury in vivo by the mitochondria targeted antioxidant MitoQ

PubMed Central

Dare, Anna J.; Bolton, Eleanor A.; Pettigrew, Gavin J.; Bradley, J. Andrew; Saeb-Parsy, Kourosh; Murphy, Michael P.

2015-01-01

Ischemia–reperfusion (IR) injury to the kidney occurs in a range of clinically important scenarios including hypotension, sepsis and in surgical procedures such as cardiac bypass surgery and kidney transplantation, leading to acute kidney injury (AKI). Mitochondrial oxidative damage is a significant contributor to the early phases of IR injury and may initiate a damaging inflammatory response. Here we assessed whether the mitochondria targeted antioxidant MitoQ could decrease oxidative damage during IR injury and thereby protect kidney function. To do this we exposed kidneys in mice to in vivo ischemia by bilaterally occluding the renal vessels followed by reperfusion for up to 24 h. This caused renal dysfunction, measured by decreased creatinine clearance, and increased markers of oxidative damage. Administering MitoQ to the mice intravenously 15 min prior to ischemia protected the kidney from damage and dysfunction. These data indicate that mitochondrial oxidative damage contributes to kidney IR injury and that mitochondria targeted antioxidants such as MitoQ are potential therapies for renal dysfunction due to IR injury. PMID:25965144

Polymorphisms in metabolism and repair genes affects DNA damage caused by open-cast coal mining exposure.

PubMed

Espitia-Pérez, Lyda; Sosa, Milton Quintana; Salcedo-Arteaga, Shirley; León-Mejía, Grethel; Hoyos-Giraldo, Luz Stella; Brango, Hugo; Kvitko, Katia; da Silva, Juliana; Henriques, João A P

2016-09-15

Increasing evidence suggest that occupational exposure to open-cast coal mining residues like dust particles, heavy metals and Polycyclic Aromatic Hydrocarbons (PAHs) may cause a wide range of DNA damage and genomic instability that could be associated to initial steps in cancer development and other work-related diseases. The aim of our study was to evaluate if key polymorphisms in metabolism genes CYP1A1Msp1, GSTM1Null, GSTT1Null and DNA repair genes XRCC1Arg194Trp and hOGG1Ser326Cys could modify individual susceptibility to adverse coal exposure effects, considering the DNA damage (Comet assay) and micronucleus formation in lymphocytes (CBMN) and buccal mucosa cells (BMNCyt) as endpoints for genotoxicity. The study population is comprised of 200 healthy male subjects, 100 open-cast coal-mining workers from "El Cerrejón" (world's largest open-cast coal mine located in Guajira - Colombia) and 100 non-exposed referents from general population. The data revealed a significant increase of CBMN frequency in peripheral lymphocytes of occupationally exposed workers carrying the wild-type variant of GSTT1 (+) gene. Exposed subjects carrying GSTT1null polymorphism showed a lower micronucleus frequency compared with their positive counterparts (FR: 0.83; P=0.04), while BMNCyt, frequency and Comet assay parameters in lymphocytes: Damage Index (DI) and percentage of DNA in the tail (Tail % DNA) were significantly higher in exposed workers with the GSTM1Null polymorphism. Other exfoliated buccal mucosa abnormalities related to cell death (Karyorrhexis and Karyolysis) were increased in GSTT/M1Null carriers. Nuclear buds were significantly higher in workers carrying the CYP1A1Msp1 (m1/m2, m2/m2) allele. Moreover, BMNCyt frequency and Comet assay parameters were significantly lower in exposed carriers of XRCC1Arg194Trp (Arg/Trp, Trp/Trp) and hOGG1Ser326Cys (Ser/Cys, Cys/Cys), thereby providing new data to the increasing evidence about the protective role of these polymorphisms. This modulation may involve specific and differentiated pathways in different tissues that also may cause a differential sensitivity related to differential induction of some enzymes. Copyright © 2016 Elsevier B.V. All rights reserved.

Allicin enhances the oxidative damage effect of amphotericin B against Candida albicans.

PubMed

An, MaoMao; Shen, Hui; Cao, YongBing; Zhang, JunDong; Cai, Yun; Wang, Rui; Jiang, YuanYing

2009-03-01

Amphotericin B (AmB) is the gold standard of antifungal treatment for the most severe invasive mycoses. In addition to the interaction of AmB with ergosterol in the fungi cell membrane, several studies have demonstrated oxidative damage involved in the fungicidal activity of AmB. In this study, allicin, an allyl sulphur compound from garlic, was shown to enhance significantly the effect of AmB against Candida albicans in vitro and in vivo, although allicin did not exert a fungicidal effect. Further study first demonstrated that allicin-mediated oxidative damage, such as phospholipid peroxidation in the plasma membrane, via influencing the defence of C. albicans against oxidative damage may be the cause of the synergistic interaction between allicin and AmB. We envision that a combination of AmB with allicin may prove to be a promising strategy for the therapy of disseminated candidiasis.

Erosion simulation of first wall beryllium armour under ITER transient heat loads

NASA Astrophysics Data System (ADS)

Bazylev, B.; Janeschitz, G.; Landman, I.; Pestchanyi, S.; Loarte, A.

2009-04-01

The beryllium is foreseen as plasma facing armour for the first wall in the ITER in form of Be-clad blanket modules in macrobrush design with brush size about 8-10 cm. In ITER significant heat loads during transient events (TE) are expected at the main chamber wall that may leads to the essential damage of the Be armour. The main mechanisms of metallic target damage remain surface melting and melt motion erosion, which determines the lifetime of the plasma facing components. Melting thresholds and melt layer depth of the Be armour under transient loads are estimated for different temperatures of the bulk Be and different shapes of transient loads. The melt motion damages of Be macrobrush armour caused by the tangential friction force and the Lorentz force are analyzed for bulk Be and different sizes of Be-brushes. The damage of FW under radiative loads arising during mitigated disruptions is numerically simulated.

UV-B Radiation Contributes to Amphibian Population Declines

NASA Astrophysics Data System (ADS)

Blaustein, Andrew

2007-05-01

UV-B (280-315 nm) radiation is the most significant biologically damaging radiation at the terrestrial surface. At the organismal level, UV-B radiation can slow growth rates, cause immune dysfunction and result in sublethal damage. UV-B radiation can lead to mutations and cell death. Over evolutionary time, UV radiation has been an important stressor on living organisms. Natural events, including impacts from comets and asteroids, volcanic activity, supernova explosions and solar flares, can cause large-scale ozone depletion with accompanying increases in UV radiation. However, these natural events are transient. Moreover, the amount of ozone damage due to natural events depends upon a number of variables, including the magnitude of the event. This is different from modern-day human-induced production of chlorofluorocarbons (CFCs) and other chemicals that deplete stratospheric ozone continuously, resulting in long-term increases in UV-B radiation at the surface of the earth. We will briefly review the effects of UV-B exposure in one group of aquatic organisms_amphibians. UV-B has been implicated as a possible factor contributing to global declines and range reductions in amphibian populations.

Importance of cell damage causing growth delay for high pressure inactivation of Saccharomyces cerevisiae

NASA Astrophysics Data System (ADS)

Nanba, Masaru; Nomura, Kazuki; Nasuhara, Yusuke; Hayashi, Manabu; Kido, Miyuki; Hayashi, Mayumi; Iguchi, Akinori; Shigematsu, Toru; Hirayama, Masao; Ueno, Shigeaki; Fujii, Tomoyuki

2013-06-01

A high pressure (HP) tolerant (barotolerant) mutant a2568D8 and a variably barotolerant mutant a1210H12 were generated from Saccharomyces cerevisiae using ultra-violet mutagenesis. The two mutants, a barosensitive mutant a924E1 and the wild-type strain, were pressurized (225 MPa), and pressure inactivation behavior was analyzed. In the wild-type strain, a proportion of the growth-delayed cells were detected after exposure to HP. In a924E1, the proportion of growth-delayed cells significantly decreased compared with the wild-type. In a2568D8, the proportion of growth-delayed cells increased and the proportion of inactivated cells decreased compared with the wild-type. In a1210H12, the growth-delayed cells could not be detected within 120 s of exposure to HP. The proportion of growth-delayed cells, which incurred the damage, would affect the survival ratio by HP. These results suggested that cellular changes in barotolerance caused by mutations are remarkably affected by the ability to recover from cellular damage, which results in a growth delay.

Methoxychlor causes mitochondrial dysfunction and oxidative damage in the mouse ovary

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, R.K.; Schuh, R.A.; Department of Anesthesiology, University of Maryland, Baltimore, MD

2006-11-01

Methoxychlor (MXC) is an organochlorine pesticide that reduces fertility in female rodents by causing ovarian atrophy, persistent estrous cyclicity, and antral follicle atresia (apoptotic cell death). Oxidative damage resulting from reactive oxygen species (ROS) generation has been demonstrated to lead to toxicant-induced cell death. Thus, this work tested the hypothesis that MXC causes oxidative damage to the mouse ovary and affects mitochondrial respiration in a manner that stimulates ROS production. For the in vitro experiments, mitochondria were collected from adult cycling mouse ovaries, treated with vehicle (dimethyl sulfoxide; DMSO) or MXC, and subjected to polarographic measurements of respiration. For themore » in vivo experiments, adult cycling CD-1 mice were dosed with either vehicle (sesame oil) or MXC for 20 days. After treatment, ovarian mitochondria were isolated and subjected to measurements of respiration and fluorimetric measurements of H{sub 2}O{sub 2} production. Some ovaries were also fixed and processed for immunohistochemistry using antibodies for ROS production markers: nitrotyrosine and 8-hydroxy-2'-deoxyguanosine (8-OHG). Ovaries from in vivo experiments were also used to measure the mRNA expression and activity of antioxidants such as Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX), and catalase (CAT). The results indicate that MXC significantly impairs mitochondrial respiration, increases production of H{sub 2}O{sub 2}, causes more staining for nitrotyrosine and 8-OHG in antral follicles, and decreases the expression and activity of SOD1, GPX, and CAT as compared to controls. Collectively, these data indicate that MXC inhibits mitochondrial respiration, causes ROS production, and decreases antioxidant expression and activity in the ovary, specifically in the antral follicles. Therefore, it is possible that MXC causes atresia of ovarian antral follicles by inducing oxidative stress through mitochondrial production of ROS.« less

Aerial pesticide application causes DNA damage in pilots from Sinaloa, Mexico.

PubMed

Martínez-Valenzuela, C; Waliszewski, S M; Amador-Muñoz, O; Meza, E; Calderón-Segura, M E; Zenteno, E; Huichapan-Martínez, J; Caba, M; Félix-Gastélum, R; Longoria-Espinoza, R

2017-01-01

The use of pesticides in agricultural production originates residues in the environment where they are applied. Pesticide aerial application is a frequent source of exposure to pesticides by persons dedicated to agricultural practices and those living in neighboring communities of sprayed fields. The aim of the study was to assess the genotoxic effects of pesticides in workers occupationally exposed to these chemicals during their aerial application to agricultural fields of Sinaloa, Mexico. The study involved 30 pilots of airplanes used to apply pesticides via aerial application and 30 unexposed controls. Damage was evaluated through the micronucleus assay and by other nuclear abnormalities in epithelial cells of oral mucosa. The highest frequency ratios (FR) equal to 269.5 corresponded to binucleated cells followed by 54.2, corresponding to cells with pyknotic nuclei, 45.2 of cells with chromatin condensation, 3.7 of cells with broken-egg, 3.6 of cells with micronucleus, and 2.0 of karyolytic cells. Age, worked time, smoking, and alcohol consumption did not have significant influence on nuclear abnormalities in the pilots studied. Pesticide exposure was the main factor for nuclear abnormality results and DNA damage. Marked genotoxic damage was developed even in younger pilots with 2 years of short working period, caused by their daily occupational exposure to pesticides.

Therapeutic effects of date palm (Phoenix dactylifera L.) pollen extract on cadmium-induced testicular toxicity.

PubMed

El-Neweshy, M S; El-Maddawy, Z K; El-Sayed, Y S

2013-12-01

Cadmium (Cd) is a well-known testicular toxicant. This study was designed to explore the long-term effects of a single low dose of Cd on spermatogenesis, and testicular dysfunction and oxidative stress, and the therapeutic potential of date palm pollen extract (DPP) in averting such reproductive damage. Adult male Wistar rats received a single intraperitoneal injection of CdCl2 (0 or 1 mg kg(-1) ). Twenty-four hours later, they started receiving DPP (0 or 40 mg kg(-1) ) orally, once daily for 56 consecutive days. Cd exposure caused significant reproductive damage via reduced weight of the reproductive organs, which includes spermatological damage (decreased sperm count and motility and increased rates of sperm abnormalities), increased oxidative stress (increased malondialdehyde and decreased reduced glutathione levels), histological alterations (necrosis, inefficient to completely arrest spermatogenesis and a reduced Johnsen's score) and decreased serum testosterone level. DPP restored spermatogenesis and attenuated the toxic effects of Cd on the reproductive system to the levels observed in the control animals. These findings support the hypothesis that the testis is particularly sensitive to Cd, which can cause testicular damage and infertility. Treatment with DPP can ameliorate the deleterious effects of Cd, probably by activating testicular endocrine and antioxidant systems. © 2012 Blackwell Verlag GmbH.

Knockdown of p53 suppresses Nanog expression in embryonic stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdelalim, Essam Mohamed, E-mail: emohamed@qf.org.qa; Molecular Neuroscience Research Center, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192; Department of Cytology and Histology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia

2014-01-10

Highlights: •We investigate the role of p53 in ESCs in the absence of DNA damage. •p53 knockdown suppresses ESC proliferation. •p53 knockdown downregulates Nanog expression. •p53 is essential for mouse ESC self-renewal. -- Abstract: Mouse embryonic stem cells (ESCs) express high levels of cytoplasmic p53. Exposure of mouse ESCs to DNA damage leads to activation of p53, inducing Nanog suppression. In contrast to earlier studies, we recently reported that chemical inhibition of p53 suppresses ESC proliferation. Here, we confirm that p53 signaling is involved in the maintenance of mouse ESC self-renewal. RNA interference-mediated knockdown of p53 induced downregulation of p21more » and defects in ESC proliferation. Furthermore, p53 knockdown resulted in a significant downregulation in Nanog expression at 24 and 48 h post-transfection. p53 knockdown also caused a reduction in Oct4 expression at 48 h post-transfection. Conversely, exposure of ESCs to DNA damage caused a higher reduction of Nanog expression in control siRNA-treated cells than in p53 siRNA-treated cells. These data show that in the absence of DNA damage, p53 is required for the maintenance of mouse ESC self-renewal by regulating Nanog expression.« less

Homologous Recombination and Translesion DNA Synthesis Play Critical Roles on Tolerating DNA Damage Caused by Trace Levels of Hexavalent Chromium

PubMed Central

Chen, Youjun; Zhou, Yi-Hui; Neo, Dayna; Clement, Jean; Takata, Minoru; Takeda, Shunichi; Sale, Julian; Wright, Fred A.; Swenberg, James A.; Nakamura, Jun

2016-01-01

Contamination of potentially carcinogenic hexavalent chromium (Cr(VI)) in the drinking water is a major public health concern worldwide. However, little information is available regarding the biological effects of a nanomoler amount of Cr(VI). Here, we investigated the genotoxic effects of Cr(VI) at nanomoler levels and their repair pathways. We found that DNA damage response analyzed based on differential toxicity of isogenic cells deficient in various DNA repair proteins is observed after a three-day incubation with K2CrO4 in REV1-deficient DT40 cells at 19.2 μg/L or higher as well as in TK6 cells deficient in polymerase delta subunit 3 (POLD3) at 9.8 μg/L or higher. The genotoxicity of Cr(VI) decreased ~3000 times when the incubation time was reduced from three days to ten minutes. TK mutation rate also significantly decreased from 6 day to 1 day exposure to Cr(VI). The DNA damage response analysis suggest that DNA repair pathways, including the homologous recombination and REV1- and POLD3-mediated error-prone translesion synthesis pathways, are critical for the cells to tolerate to DNA damage caused by trace amount of Cr(VI). PMID:27907204

Bioactivation of carboxylic acid compounds by UDP-Glucuronosyltransferases to DNA-damaging intermediates: role of glycoxidation and oxidative stress in genotoxicity.

PubMed

Sallustio, Benedetta C; Degraaf, Yvette C; Weekley, Josephine S; Burcham, Philip C

2006-05-01

Nonenzymatic modification of proteins by acyl glucuronides is well documented; however, little is known about their potential to damage DNA. We have previously reported that clofibric acid undergoes glucuronidation-dependent bioactivation to DNA-damaging species in cultured mouse hepatocytes. The aim of this study was to investigate the mechanisms underlying such DNA damage, and to screen chemically diverse carboxylic acid drugs for their DNA-damaging potential in glucuronidation proficient murine hepatocytes. Cells were incubated with each aglycone for 18 h, followed by assessment of compound cytotoxicity using the MTT assay and evaluation of DNA damage using the Comet assay. Relative cytotoxic potencies were ketoprofen > diclofenac, benoxaprofen, nafenopin > gemfibrozil, probenecid > bezafibrate > clofibric acid. At a noncytotoxic (0.1 mM) concentration, only benoxaprofen, nafenopin, clofibric acid, and probenecid significantly increased Comet moments (P < 0.05 Kruskal-Wallis). Clofibric acid and probenecid exhibited the greatest DNA-damaging potency, producing significant DNA damage at 0.01 mM concentrations. The two drugs produced maximal increases in Comet moment of 4.51 x and 2.57 x control, respectively. The glucuronidation inhibitor borneol (1 mM) abolished the induction of DNA damage by 0.5 mM concentrations of clofibric acid and probenecid. In an in vitro cell-free system, clofibric acid glucuronide was 10 x more potent than glucuronic acid in causing DNA strand-nicking, although both compounds showed similar rates of autoxidation to generate hydroxyl radicals. In cultured hepatocytes, the glycation inhibitor, aminoguanidine, and the iron chelator, desferrioxamine mesylate, inhibited DNA damage by clofibric acid, whereas the free radical scavengers Trolox and butylated hydroxytoluene, and the superoxide dismutase mimetic bis-3,5-diisopropylsalicylate had no effect. In conclusion, clinically relevant concentrations of two structurally unrelated carboxylic acids, probenecid and clofibric acid, induced DNA damage in isolated hepatocytes via glucuronidation- dependent pathways. These findings suggest acyl glucuronides are able to access and damage nuclear DNA via iron-catalyzed glycation/glycoxidative processes.

2016 Arte Poster Competition First Place Winner: Circadian Rhythm and UV-Induced Skin Damage: An In Vivo Study.

PubMed

Guan, Linna; Suggs, Amanda; Ahsanuddin, Sayeeda; Tarrillion, Madeline; Selph, Jacqueline; Lam, Minh; Baron, Elma

2016-09-01

Exposure of the skin to ultraviolet (UV) irradiation causes many detrimental effects through mechanisms related to oxidative stress and DNA damage. Excessive oxidative stress can cause apoptosis and cellular dysfunction of epidermal cells leading to cellular senescence and connective tissue degradation. Direct and indirect damage to DNA predisposes the skin to cancer formation. Chronic UV exposure also leads to skin aging manifested as wrinkling, loss of skin tone, and decreased resilience. Fortunately, human skin has several natural mechanisms for combating UV-induced damage. The mechanisms operate on a diurnal rhythm, a cycle that repeats approximately every 24 hours. It is known that the circadian rhythm is involved in many skin physiologic processes, including water regulation and epidermal stem cell function. This study evaluated whether UV damage and the skin's natural mechanisms of inflammation and repair are also affected by circadian rhythm. We looked at UV-induced erythema on seven human subjects irradiated with simulated solar radiation in the morning (at 08:00 h) versus in the afternoon (at 16:00 h). Our data suggest that the same dose of UV radiation induces significantly more inflammation in the morning than in the afternoon. Changes in protein expression relevant to DNA damage, such as xeroderma pigmentosum, complementation group A (XPA), and cyclobutane pyrimidine dimers (CPD) from skin biopsies correlated with our clinical results. Both XPA and CPD levels were higher after the morning UV exposure compared with the afternoon exposure.

J Drugs Dermatol. 2016;15(9):1124-1130.

Tsunami hazards to U.S. coasts from giant earthquakes in Alaska

USGS Publications Warehouse

Ryan, Holly F.; von Huene, Roland E.; Scholl, Dave; Kirby, Stephen

2012-01-01

In the aftermath of Japan's devastating 11 March 2011Mw 9.0 Tohoku earthquake and tsunami, scientists are considering whether and how a similar tsunami could be generated along the Alaskan-Aleutian subduction zone (AASZ). A tsunami triggered by an earthquake along the AASZ would cross the Pacific Ocean and cause extensive damage along highly populated U.S. coasts, with ports being particularly vulnerable. For example, a tsunami in 1946 generated by a Mw 8.6 earthquake near Unimak Pass, Alaska (Figure 1a), caused significant damage along the U.S. West Coast, took 150 lives in Hawaii, and inundated shorelines of South Pacific islands and Antarctica [Fryer et al., 2004; Lopez and Okal, 2006]. The 1946 tsunami occurred before modern broadband seismometers were in place, and the mechanisms that created it remain poorly understood.

On the influence of ion exchange on the local structure of the titanosilicate ETS-10.

PubMed

Pavel, Claudiu C; Zibrowius, Bodo; Löffler, Elke; Schmidt, Wolfgang

2007-07-14

The effect of ion exchange with different monovalent cations (NH(4)(+), K(+), Na(+) and Cs(+)) on the local structure of the titanosilicate ETS-10 has been studied by (29)Si MAS NMR and Raman spectroscopy. Although X-ray diffraction shows no significant influence of ion exchange on the long range order, ammonium exchange is found to result in substantial damage to the local structure. Ion exchange experiments with alkali cations under significantly more acidic conditions clearly show that the structural damage brought about by ammonium exchange is not caused by the low pH of the exchange solution. The exchange with potassium and caesium ions also leads to significant changes in the (29)Si NMR and Raman spectra. However, these changes can largely be reversed by sodium back-exchange.

Dieldrin exposure induces oxidative damage in the mouse nigrostriatal dopamine system

PubMed Central

Hatcher, Jaime M.; Richardson, Jason R.; Guillot, Thomas S.; McCormack, Alison L.; Di Monte, Donato A.; Jones, Dean P.; Pennell, Kurt D.; Miller, Gary W.

2007-01-01

Numerous epidemiological studies have shown an association between pesticide exposure and an increased risk of developing Parkinson’s disease (PD). Here, we provide evidence that the insecticide dieldrin causes specific oxidative damage in the nigrostriatal dopamine (DA) system. We report that exposure of mice to low levels of dieldrin for 30 days resulted in alterations in dopamine-handling as evidenced by a decrease in dopamine metabolites, DOPAC (31.7% decrease) and HVA (29.2% decrease) and significantly increased cysteinyl-catechol levels in the striatum. Furthermore, dieldrin resulted in a 53% decrease in total glutathione, an increase in the redox potential of glutathione, and a 90% increase in protein carbonyls. α-Synuclein protein expression was also significantly increased in the striatum (25% increase). Finally, dieldrin caused a significant decrease in striatal expression of the dopamine transporter as measured by 3H-WIN 35,428 binding and 3H-dopamine uptake. These alterations occurred in the absence of dopamine neuron loss in the substantia nigra pars compacta. These effects represent the ability of low doses of dieldrin to increase the vulnerability of nigrostriatal dopamine neurons by inducing oxidative stress and suggest that pesticide exposure may act as a promoter of PD. PMID:17291500

Comparison of hair shaft damage after chemical treatment in Asian, White European, and African hair.

PubMed

Lee, Yoonhee; Kim, Youn-Duk; Pi, Long-Quan; Lee, Sung Yul; Hong, Hannah; Lee, Won-Soo

2014-09-01

Diverse causes of extrinsic damage to the hair shaft have been documented and can be roughly divided into physical and chemical causes. Chemical causes of hair damage include bleaching, hair dyeing, and perming. The goal of this study was to investigate differences in patterns of serial damage in Asian, White European (WE), and African hair after chemical stress imposed by straightening and coloring treatments. Hairs were divided into control and treatment groups (straightening, coloring, and a combination of straightening and coloring). At 24 hours after the final treatment, patterns of hair damage were evaluated using transmission electron microscopy (TEM) and lipid TEM. Grades of hair cuticle and cortex damage were evaluated by three dermatologists. In the TEM examination, the cuticle of Asian hair proved to be resistant to damage caused by straightening treatments, whereas the WE hair cuticle and cortex were relatively susceptible to stress imposed by coloring treatments. In the combination treatment of straightening and coloring, African hair emerged as the most resistant to stress. In the lipid TEM examination, no notable differences in cell membrane complex damage were observed among the three groups of hairs. The present study suggests that WE hair is relatively susceptible and African hair is more resistant to chemical stresses, such as those imposed by straightening and coloring. © 2013 The International Society of Dermatology.

7 CFR 51.882 - U.S. Fancy Table.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Grades § 51.882 U.S. Fancy Table. “U.S. Fancy Table” consists of bunches of well developed grapes of one...) Berries not damaged by: (1) Any other cause. (g) Bunches not damaged by: (1) Shot berries; (2) Dried...) Stems not damaged by: (1) Freezing; (2) Any other cause. (i) Size: (1) For berries: Exclusive of shot...

7 CFR 51.882 - U.S. Fancy Table.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Grades § 51.882 U.S. Fancy Table. “U.S. Fancy Table” consists of bunches of well developed grapes of one...) Berries not damaged by: (1) Any other cause. (g) Bunches not damaged by: (1) Shot berries; (2) Dried...) Stems not damaged by: (1) Freezing; (2) Any other cause. (i) Size: (1) For berries: Exclusive of shot...

Burning Feet

MedlinePlus

... are most often a sign of nerve damage (peripheral neuropathy). Nerve damage has many different causes, including diabetes, ... if any of the various conditions that cause peripheral neuropathy are to blame. Eleftheriadou I, et al. A ...

Cerebellar Degeneration

MedlinePlus

... cause inflammation in the brain, including the cerebellum multiple sclerosis, in which damage to the insulating membrane (myelin) ... cause inflammation in the brain, including the cerebellum multiple sclerosis, in which damage to the insulating membrane (myelin) ...

Sam68 Is Required for DNA Damage Responses via Regulating Poly(ADP-ribosyl)ation

PubMed Central

Hodgson, Andrea; Wier, Eric M.; Wen, Matthew G.; Kamenyeva, Olena; Xia, Xue; Koo, Lily Y.

2016-01-01

The rapid and robust synthesis of polymers of adenosine diphosphate (ADP)-ribose (PAR) chains, primarily catalyzed by poly(ADP-ribose) polymerase 1 (PARP1), is crucial for cellular responses to DNA damage. However, the precise mechanisms through which PARP1 is activated and PAR is robustly synthesized are not fully understood. Here, we identified Src-associated substrate during mitosis of 68 kDa (Sam68) as a novel signaling molecule in DNA damage responses (DDRs). In the absence of Sam68, DNA damage-triggered PAR production and PAR-dependent DNA repair signaling were dramatically diminished. With serial cellular and biochemical assays, we demonstrated that Sam68 is recruited to and significantly overlaps with PARP1 at DNA lesions and that the interaction between Sam68 and PARP1 is crucial for DNA damage-initiated and PARP1-conferred PAR production. Utilizing cell lines and knockout mice, we illustrated that Sam68-deleted cells and animals are hypersensitive to genotoxicity caused by DNA-damaging agents. Together, our findings suggest that Sam68 plays a crucial role in DDR via regulating DNA damage-initiated PAR production. PMID:27635653

Quantitative Study of Vulnerability / Damage Curves in South Africa

NASA Astrophysics Data System (ADS)

Pule, Tebogo

2014-05-01

Southern Africa is considered a stable continental region in spite of several cases of reported earthquakes, which caused considerable damage and casualties particularly in the mining industry. Most buildings and structures in South Africa are not designed to resist any intensity of earthquake and most architects, engineers and builders in the country do not consider seismic resistance as a design requirement. This is mainly because the region has not experienced any large and serious destructive earthquake in recent years. The most destructive earthquake recorded in South Africa is the Ceres earthquake of 1969. The earthquake with a magnitude of 6.3 occurred on September 29, 1969 in the Ceres-Tulbagh region of the Western Cape Province about 100 km northeast of Cape Town. Serious damage occurred to certain buildings in the area (amounting to a total of U.S. 24 million). The structural damage varied from almost total destruction of old and poorly constructed buildings to large cracks in the better-built ones, twelve people were killed and many more were injured. Another event that caused severe damage to infrastructure occurred on March 9, 2005 at Stilfontein near Klerksdorp. It is known that up to 40 or more tremors are recorded monthly in Southern Africa, the locations are predominantly in the places surrounding the gold mining areas with many events around the Carletonville and Klerksdorp areas. Recent years have seen at least four mining induced tremors causing significant damage (Welkom 1976, Klerksdorp 1977, Welkom 1989 and Carletonville 1992). Such events show that it is very necessary to take seismic events into account in the design of any infrastructure. Assessing and understanding the risk facing the South African cities as a result of major seismic activity has been paid little attention. The main focus of this study is to use results of a deterministic hazard assessment to develop the most suitable damage curves for twelve of the most common building classes in four of the major cities in South Africa, namely, Johannesburg, Cape Town, Durban and Port Elizabeth.

Mitochondrial Cardiomyopathy Caused by Elevated Reactive Oxygen Species and Impaired Cardiomyocyte Proliferation.

PubMed

Zhang, Donghui; Li, Yifei; Heims-Waldron, Danielle; Bezzerides, Vassilios; Guatimosim, Silvia; Guo, Yuxuan; Gu, Fei; Zhou, Pingzhu; Lin, Zhiqiang; Ma, Qing; Liu, Jianming; Wang, Da-Zhi; Pu, William T

2018-01-05

Although mitochondrial diseases often cause abnormal myocardial development, the mechanisms by which mitochondria influence heart growth and function are poorly understood. To investigate these disease mechanisms, we studied a genetic model of mitochondrial dysfunction caused by inactivation of Tfam (transcription factor A, mitochondrial), a nuclear-encoded gene that is essential for mitochondrial gene transcription and mitochondrial DNA replication. Tfam inactivation by Nkx2.5 Cre caused mitochondrial dysfunction and embryonic lethal myocardial hypoplasia. Tfam inactivation was accompanied by elevated production of reactive oxygen species (ROS) and reduced cardiomyocyte proliferation. Mosaic embryonic Tfam inactivation confirmed that the block to cardiomyocyte proliferation was cell autonomous. Transcriptional profiling by RNA-seq demonstrated the activation of the DNA damage pathway. Pharmacological inhibition of ROS or the DNA damage response pathway restored cardiomyocyte proliferation in cultured fetal cardiomyocytes. Neonatal Tfam inactivation by AAV9-cTnT-Cre caused progressive, lethal dilated cardiomyopathy. Remarkably, postnatal Tfam inactivation and disruption of mitochondrial function did not impair cardiomyocyte maturation. Rather, it elevated ROS production, activated the DNA damage response pathway, and decreased cardiomyocyte proliferation. We identified a transient window during the first postnatal week when inhibition of ROS or the DNA damage response pathway ameliorated the detrimental effect of Tfam inactivation. Mitochondrial dysfunction caused by Tfam inactivation induced ROS production, activated the DNA damage response, and caused cardiomyocyte cell cycle arrest, ultimately resulting in lethal cardiomyopathy. Normal mitochondrial function was not required for cardiomyocyte maturation. Pharmacological inhibition of ROS or DNA damage response pathways is a potential strategy to prevent cardiac dysfunction caused by some forms of mitochondrial dysfunction. © 2017 American Heart Association, Inc.

Genotoxic effect of ethacrynic acid and impact of antioxidants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, William M.; Hoffman, Jared D.; Loo, George, E-mail: g_loo@uncg.edu

It is known that ethacrynic acid (EA) decreases the intracellular levels of glutathione. Whether the anticipated oxidative stress affects the structural integrity of DNA is unknown. Therefore, DNA damage was assessed in EA-treated HCT116 cells, and the impact of several antioxidants was also determined. EA caused both concentration-dependent and time-dependent DNA damage that eventually resulted in cell death. Unexpectedly, the DNA damage caused by EA was intensified by either ascorbic acid or trolox. In contrast, EA-induced DNA damage was reduced by N-acetylcysteine and by the iron chelator, deferoxamine. In elucidating the DNA damage, it was determined that EA increased themore » production of reactive oxygen species, which was inhibited by N-acetylcysteine and deferoxamine but not by ascorbic acid and trolox. Also, EA decreased glutathione levels, which were inhibited by N-acetylcysteine. But, ascorbic acid, trolox, and deferoxamine neither inhibited nor enhanced the capacity of EA to decrease glutathione. Interestingly, the glutathione synthesis inhibitor, buthionine sulfoxime, lowered glutathione to a similar degree as EA, but no noticeable DNA damage was found. Nevertheless, buthionine sulfoxime potentiated the glutathione-lowering effect of EA and intensified the DNA damage caused by EA. Additionally, in examining redox-sensitive stress gene expression, it was found that EA increased HO-1, GADD153, and p21mRNA expression, in association with increased nuclear localization of Nrf-2 and p53 proteins. In contrast to ascorbic acid, trolox, and deferoxamine, N-acetylcysteine suppressed the EA-induced upregulation of GADD153, although not of HO-1. Overall, it is concluded that EA has genotoxic properties that can be amplified by certain antioxidants. - Highlights: • Ethacrynic acid (EA) caused cellular DNA damage. • EA-induced DNA damage was potentiated by ascorbic acid or trolox. • EA increased ROS production, not inhibited by ascorbic acid or trolox. • EA decreased glutathione levels, not prevented by ascorbic acid or trolox. • Buthionine sulfoxime intensified the DNA damage caused by EA.« less

Recorded motions of the 6 April 2009 Mw 6.3 L'Aquila, Italy, earthquake and implications for building structural damage: Overview

USGS Publications Warehouse

Celebi, M.; Bazzurro, P.; Chiaraluce, L.; Clemente, P.; Decanini, L.; Desortis, A.; Ellsworth, W.; Gorini, A.; Kalkan, E.; Marcucci, S.; Milana, G.; Mollaioli, F.; Olivieri, M.; Paolucci, R.; Rinaldis, D.; Rovelli, A.; Sabetta, F.; Stephens, C.

2010-01-01

The normal-faulting earthquake of 6 April 2009 in the Abruzzo Region of central Italy caused heavy losses of life and substantial damage to centuriesold buildings of significant cultural importance and to modern reinforcedconcrete- framed buildings with hollow masonry infill walls. Although structural deficiencies were significant and widespread, the study of the characteristics of strong motion data from the heavily affected area indicated that the short duration of strong shaking may have spared many more damaged buildings from collapsing. It is recognized that, with this caveat of shortduration shaking, the infill walls may have played a very important role in preventing further deterioration or collapse of many buildings. It is concluded that better new or retrofit construction practices that include reinforcedconcrete shear walls may prove helpful in reducing risks in such seismic areas of Italy, other Mediterranean countries, and even in United States, where there are large inventories of deficient structures. ?? 2010, Earthquake Engineering Research Institute.

Transport properties of damaged materials. Cementitious barriers partnership

DOE Office of Scientific and Technical Information (OSTI.GOV)

Langton, C.

2014-11-01

The objective of the Cementitious Barriers Partnership (CBP) project is to develop tools to improve understanding and prediction of the long-term structural, hydraulic, and chemical performance of cementitious barriers used in low-level waste storage applications. One key concern for the long-term durability of concrete is the degradation of the cementitious matrix, which occurs as a result of aggressive chemical species entering the material or leaching out in the environment, depending on the exposure conditions. The objective of the experimental study described in this report is to provide experimental data relating damage in cementitious materials to changes in transport properties, whichmore » can eventually be used to support predictive model development. In order to get results within a reasonable timeframe and to induce as much as possible uniform damage level in materials, concrete samples were exposed to freezing and thawing (F/T) cycles. The methodology consisted in exposing samples to F/T cycles and monitoring damage level with ultrasonic pulse velocity measurements. Upon reaching pre-selected damage levels, samples were tested to evaluate changes in transport properties. Material selection for the study was motivated by the need to get results rapidly, in order to assess the relevance of the methodology. Consequently, samples already available at SIMCO from past studies were used. They consisted in three different concrete mixtures cured for five years in wet conditions. The mixtures had water-to-cement ratios of 0.5, 0.65 and 0.75 and were prepared with ASTM Type I cement only. The results showed that porosity is not a good indicator for damage caused by the formation of microcracks. Some materials exhibited little variations in porosity even for high damage levels. On the other hand, significant variations in tortuosity were measured in all materials. This implies that damage caused by internal pressure does not necessarily create additional pore space in the microstructure, but likely creates new thin pathways between existing pore space for species to travel. These results have a significant impact on modeling efforts. Models relating porosity to tortuosity and permeability are unlikely to provide the correct basis for predicting long-term durability of concrete sustaining internal pressures and microcrack formation. Other avenues like the modeling of internal crystallization pressure need to be explored.« less

Fusarium infection causes genotoxic disorders and antioxidant-based damages in Orobanche spp.

PubMed

Aybeke, Mehmet

2017-08-01

This study aims to evaluate the toxic effects of Fusarium oxysporum on root parasitic weed, Orobanche spp. Comparative genetic and gene expression studies were conducted on uninfected and fungus-infected orobanches. In genetic studies, isolated total DNA was amplified by RAPD PCR. Fragment properties were analysed by GTS test. According to the results, the fragment properties of control and Fusarium infected (experimental) groups varied widely; and it has been observed that Fusarium has genotoxic effects on the DNA of orobanches. In gene expression studies, the expression levels of genes encoding enzymes or proteins were associated with ROS damage and toxic effects, therefore, gene expressions of Mn-superoxide dismutase (SOD), Zn-superoxide dismutase (=SOD2, mitochondrial), glutamine synthetase (GS), heat shock protein gene (HSP70), BAX, Caspase-3 and BCL2 were significantly higher in the experimental group. In the light of obtained data, it was concluded that F. oxysporum (1) caused heavy ROS damage in Orobanche (2) induced significant irrevocable genotoxic effects on the DNA of Orobanche, (3) degraded protein metabolism and synthesis, and finally (4) triggered apoptosis. The results of this study can be a ground for further research on reducing the toxic effects of Fusarium on agricultural products, so that advancements in bio-herbicide technology may provide a sustainable agricultural production. Copyright © 2017 Elsevier GmbH. All rights reserved.

A Benzothiazole Derivative (5g) Induces DNA Damage And Potent G2/M Arrest In Cancer Cells.

PubMed

Hegde, Mahesh; Vartak, Supriya V; Kavitha, Chandagirikoppal V; Ananda, Hanumappa; Prasanna, Doddakunche S; Gopalakrishnan, Vidya; Choudhary, Bibha; Rangappa, Kanchugarakoppal S; Raghavan, Sathees C

2017-05-31

Chemically synthesized small molecules play important role in anticancer therapy. Several chemical compounds have been reported to damage the DNA, either directly or indirectly slowing down the cancer cell progression by causing a cell cycle arrest. Direct or indirect reactive oxygen species formation causes DNA damage leading to cell cycle arrest and subsequent cell death. Therefore, identification of chemically synthesized compounds with anticancer potential is important. Here we investigate the effect of benzothiazole derivative (5g) for its ability to inhibit cell proliferation in different cancer models. Interestingly, 5g interfered with cell proliferation in both, cell lines and tumor cells leading to significant G2/M arrest. 5g treatment resulted in elevated levels of ROS and subsequently, DNA double-strand breaks (DSBs) explaining observed G2/M arrest. Consistently, we observed deregulation of many cell cycle associated proteins such as CDK1, BCL2 and their phosphorylated form, CyclinB1, CDC25c etc. Besides, 5g treatment led to decreased levels of mitochondrial membrane potential and activation of apoptosis. Interestingly, 5g administration inhibited tumor growth in mice without significant side effects. Thus, our study identifies 5g as a potent biochemical inhibitor to induce G2/M phase arrest of the cell cycle, and demonstrates its anticancer properties both ex vivo and in vivo.

Genotoxic effect of 6-gingerol on human hepatoma G2 cells.

PubMed

Yang, Guang; Zhong, Laifu; Jiang, Liping; Geng, Chengyan; Cao, Jun; Sun, Xiance; Ma, Yufang

2010-04-15

6-gingerol, a major component of ginger, has antioxidant, anti-apoptotic, and anti-inflammatory activities. However, some dietary phytochemicals possess pro-oxidant effects as well, and the risk of adverse effects is increased by raising the use of doses. The aim of this study was to assess the genotoxic effects of 6-gingerol and to clarify the mechanisms, using human hepatoma G2 (HepG2) cells. Exposure of the cells to 6-gingerol caused significant increase of DNA migration in comet assay, increase of micronuclei frequencies at high concentrations at 20-80 and 20-40 microM, respectively. These results indicate that 6-gingerol caused DNA strand breaks and chromosome damage. To further elucidate the underlying mechanisms, we tested lysosomal membrane stability, mitochondrial membrane potential, the intracellular generation of reactive oxygen species (ROS) and reduced glutathione (GSH). In addition, the level of oxidative DNA damage was evaluated by immunocytochemical analysis on 8-hydroxydeoxyguanosine (8-OHdG). Results showed that lysosomal membrane stability was reduced after treatment by 6-gingerol (20-80 microM) for 40 min, mitochondrial membrane potential decreased after treatment for 50 min, GSH and ROS levels were significantly increased after treatment for 60 min. These suggest 6-gingerol induces genotoxicity probably by oxidative stress; lysosomal and mitochondrial damage were observed in 6-gingerol-induced toxicity. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

DNA Damage, Cell Cycle Arrest, and Apoptosis Induction Caused by Lead in Human Leukemia Cells

PubMed Central

Yedjou, Clement G.; Tchounwou, Hervey M.; Tchounwou, Paul B.

2015-01-01

In recent years, the industrial use of lead has been significantly reduced from paints and ceramic products, caulking, and pipe solder. Despite this progress, lead exposure continues to be a significant public health concern. The main goal of this research was to determine the in vitro mechanisms of lead nitrate [Pb(NO3)2] to induce DNA damage, apoptosis, and cell cycle arrest in human leukemia (HL-60) cells. To reach our goal, HL-60 cells were treated with different concentrations of Pb(NO3)2 for 24 h. Live cells and necrotic death cells were measured by the propidium idiode (PI) assay using the cellometer vision. Cell apoptosis was measured by the flow cytometry and DNA laddering. Cell cycle analysis was evaluated by the flow cytometry. The result of the PI demonstrated a significant (p < 0.05) increase of necrotic cell death in Pb(NO3)2-treated cells, indicative of membrane rupture by Pb(NO3)2 compared to the control. Data generated from the comet assay indicated a concentration-dependent increase in DNA damage, showing a significant increase (p < 0.05) in comet tail-length and percentages of DNA cleavage. Data generated from the flow cytometry assessment indicated that Pb(NO3)2 exposure significantly (p < 0.05) increased the proportion of caspase-3 positive cells (apoptotic cells) compared to the control. The flow cytometry assessment also indicated Pb(NO3)2 exposure caused cell cycle arrest at the G0/G1 checkpoint. The result of DNA laddering assay showed presence of DNA smear in the agarose gel with little presence of DNA fragments in the treated cells compared to the control. In summary, Pb(NO3)2 inhibits HL-60 cells proliferation by not only inducing DNA damage and cell cycle arrest at the G0/G1 checkpoint but also triggering the apoptosis through caspase-3 activation and nucleosomal DNA fragmentation accompanied by secondary necrosis. We believe that our study provides a new insight into the mechanisms of Pb(NO3)2 exposure and its associated adverse health effects. PMID:26703663

DNA Damage, Cell Cycle Arrest, and Apoptosis Induction Caused by Lead in Human Leukemia Cells.

PubMed

Yedjou, Clement G; Tchounwou, Hervey M; Tchounwou, Paul B

2015-12-22

In recent years, the industrial use of lead has been significantly reduced from paints and ceramic products, caulking, and pipe solder. Despite this progress, lead exposure continues to be a significant public health concern. The main goal of this research was to determine the in vitro mechanisms of lead nitrate [Pb(NO₃)₂] to induce DNA damage, apoptosis, and cell cycle arrest in human leukemia (HL-60) cells. To reach our goal, HL-60 cells were treated with different concentrations of Pb(NO₃)₂ for 24 h. Live cells and necrotic death cells were measured by the propidium idiode (PI) assay using the cellometer vision. Cell apoptosis was measured by the flow cytometry and DNA laddering. Cell cycle analysis was evaluated by the flow cytometry. The result of the PI demonstrated a significant (p < 0.05) increase of necrotic cell death in Pb(NO₃)₂-treated cells, indicative of membrane rupture by Pb(NO₃)₂ compared to the control. Data generated from the comet assay indicated a concentration-dependent increase in DNA damage, showing a significant increase (p < 0.05) in comet tail-length and percentages of DNA cleavage. Data generated from the flow cytometry assessment indicated that Pb(NO₃)₂ exposure significantly (p < 0.05) increased the proportion of caspase-3 positive cells (apoptotic cells) compared to the control. The flow cytometry assessment also indicated Pb(NO₃)₂ exposure caused cell cycle arrest at the G₀/G₁ checkpoint. The result of DNA laddering assay showed presence of DNA smear in the agarose gel with little presence of DNA fragments in the treated cells compared to the control. In summary, Pb(NO₃)₂ inhibits HL-60 cells proliferation by not only inducing DNA damage and cell cycle arrest at the G₀/G₁ checkpoint but also triggering the apoptosis through caspase-3 activation and nucleosomal DNA fragmentation accompanied by secondary necrosis. We believe that our study provides a new insight into the mechanisms of Pb(NO₃)₂ exposure and its associated adverse health effects.

7 CFR 51.2075 - U.S. No. 1.

Code of Federal Regulations, 2012 CFR

2012-01-01

... material. The shells are clean, fairly bright, fairly uniform color, and free from damage caused by..., rancidity, and free from damage caused by insects, mold, gum, skin discoloration, shriveling, brown spot or...

Hip Replacement: MedlinePlus Health Topic

MedlinePlus

... damage. The most common cause of damage is osteoarthritis . Osteoarthritis causes pain, swelling, and reduced motion in your ... Food and Drug Administration) Genetics Genetics Home Reference: osteoarthritis (National Library of Medicine) Images Hip joint replacement - ...

Ulcerogenicity and effect on inhibition of prostaglandin generation of indometacin farnesil, a prodrug of indomethacin, in rat gastric mucosa: comparison with indomethacin or loxoprofen.

PubMed

Arakawa, T; Fukuda, T; Nakagawa, K; Higuchi, K; Watanabe, T; Tominaga, K; Kobayashi, K

1995-01-01

Indometacin farnesil was compared with indomethacin and loxoprofen in rats to ascertain whether it caused less gastric mucosal damage than the two older drugs. Damage was evaluated in terms of the size of ulcers that formed after oral administration and the changes in concentrations of prostaglandins E2 and I2 in the mucosa. Indometacin farnesil caused less damage than indomethacin and tended to cause less damage than loxoprofen. Indometacin farnesil was less potent than indomethacin in inhibiting prostaglandin generation by gastric mucosa. This property of indometacin farnesil may contribute to the low ulcerogenicity of this compound.

Fault Analysis on Bevel Gear Teeth Surface Damage of Aeroengine

NASA Astrophysics Data System (ADS)

Cheng, Li; Chen, Lishun; Li, Silu; Liang, Tao

2017-12-01

Aiming at the trouble phenomenon for bevel gear teeth surface damage of Aero-engine, Fault Tree of bevel gear teeth surface damage was drawing by logical relations, the possible cause of trouble was analyzed, scanning electron-microscope, energy spectrum analysis, Metallographic examination, hardness measurement and other analysis means were adopted to investigate the spall gear tooth. The results showed that Material composition, Metallographic structure, Micro-hardness, Carburization depth of the fault bevel gear accord with technical requirements. Contact fatigue spall defect caused bevel gear teeth surface damage. The small magnitude of Interference of accessory gearbox install hole and driving bevel gear bearing seat was mainly caused. Improved measures were proposed, after proof, Thermoelement measures are effective.

The effects of deformation, ischemia, and reperfusion on the development of muscle damage during prolonged loading.

PubMed

Loerakker, S; Manders, E; Strijkers, G J; Nicolay, K; Baaijens, F P T; Bader, D L; Oomens, C W J

2011-10-01

Deep tissue injury (DTI) is a severe form of pressure ulcer where tissue damage starts in deep tissues underneath intact skin. In the present study, the contributions of deformation, ischemia, and reperfusion to skeletal muscle damage development were examined in a rat model during a 6-h period. Magnetic resonance imaging (MRI) was used to study perfusion (contrast-enhanced MRI) and tissue integrity (T2-weighted MRI). The levels of tissue deformation were estimated using finite element models. Complete ischemia caused a gradual homogeneous increase in T2 (∼20% during the 6-h period). The effect of reperfusion on T2 was highly variable, depending on the anatomical location. In experiments involving deformation, inevitably associated with partial ischemia, a variable T2 increase (17-66% during the 6-h period) was observed reflecting the significant variation in deformation (with two-dimensional strain energies of 0.60-1.51 J/mm) and ischemia (50.8-99.8% of the leg) between experiments. These results imply that deformation, ischemia, and reperfusion all contribute to the damage process during prolonged loading, although their importance varies with time. The critical deformation threshold and period of ischemia that cause muscle damage will certainly vary between individuals. These variations are related to intrinsic factors, such as pathological state, which partly explain the individual susceptibility to the development of DTI and highlight the need for regular assessments of individual subjects.

Ultrasonic versus monopolar energy-based surgical devices in terms of surgical smoke and lateral thermal damage (ULMOST): a randomized controlled trial.

PubMed

Choi, Chahien; Do, In-Gu; Song, Taejong

2018-04-09

The purpose of this study was to compare the degree of surgical smoke or vapor and lateral thermal damage caused by two different energy-based surgical devices (ESDs) used in colpotomy during total laparoscopic hysterectomy. Patients undergoing laparoscopic hysterectomy were randomly assigned to an ultrasonic ESD group (n = 20) or monopolar ESD group (n = 20). Colpotomy was performed using the assigned ESD. The degree of surgical smoke or vapor obstructing the laparoscopic view was assessed by two independent reviewers using a 5-point Likert scale, in which a higher score indicates worse visibility. The degree of the lateral thermal damage was measured as the width from the point of instrument application to the margins of the unchanged nearby tissue using a light microscope. The baseline characteristics did not statistically differ between the two groups. The degree of surgical smoke or vapor obstructing vision was 1.2 ± 0.8 points in the ultrasonic group and 3.9 ± 0.7 points in the monopolar groups (p < 0.001). The lateral thermal damage was significantly increased in the monopolar group compared to in the ultrasound group (1500 µm [1200-2500 µm] vs. 950 µm [650-1725 µm], p = 0.037). Ultrasonic ESD had better laparoscopic visibility and caused less lateral thermal damage during colpotomy compared to monopolar device.

Agricultural losses related to frost events: use of the 850 hPa level temperature as an explanatory variable of the damage cost

NASA Astrophysics Data System (ADS)

Papagiannaki, K.; Lagouvardos, K.; Kotroni, V.; Papagiannakis, G.

2014-09-01

The objective of this study is the analysis of damaging frost events in agriculture, by examining the relationship between the daily minimum temperature in the lower atmosphere (at an isobaric level of 850 hPa) and crop production losses. Furthermore, the study suggests a methodological approach for estimating agriculture risk due to frost events, with the aim of estimating the short-term probability and magnitude of frost-related financial losses for different levels of 850 hPa temperature. Compared with near-surface temperature forecasts, temperature forecasts at the level of 850 hPa are less influenced by varying weather conditions or by local topographical features; thus, they constitute a more consistent indicator of the forthcoming weather conditions. The analysis of the daily monetary compensations for insured crop losses caused by weather events in Greece shows that, during the period 1999-2011, frost caused more damage to crop production than any other meteorological phenomenon. Two regions of different geographical latitudes are examined further, to account for the differences in the temperature ranges developed within their ecological environment. Using a series of linear and logistic regressions, we found that minimum temperature (at an 850 hPa level), grouped into three categories according to its magnitude, and seasonality, are significant variables when trying to explain crop damage costs, as well as to predict and quantify the likelihood and magnitude of damaging frost events.

Distribution and diversity of Russian wheat aphid (Hemiptera: Aphididae) biotypes in South Africa and Lesotho.

PubMed

Jankielsohn, Astrid

2011-10-01

Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Hemiptera: Aphididae) was recorded for the first time in South Africa in 1978. In 2005, a second biotype, RWASA2, emerged, and here we report on the emergence of yet another biotype, found for the first time in 2009. The discovery of new Russian wheat aphid biotypes is a significant challenge to the wheat, Triticum aestivum L., industry in South Africa. Russian wheat aphid resistance in wheat, that offered wheat producers a long-term solution to Russian wheat aphid control, may no longer be effective in areas where the new biotypes occur. It is therefore critical to determine the diversity and extent of distribution of biotypes in South Africa to successfully deploy Russian wheat aphid resistance in wheat. Screening of 96 Russian wheat aphid clones resulted in identification of three Russian wheat aphid biotypes. Infestations of RWASA1 caused susceptible damage symptoms only in wheat entries containing the Dn3 gene. Infestations of RWASA2 caused susceptible damage symptoms in wheat entries containing Dn1, Dn2, Dn3, and Dn9 resistant genes. Based on the damage-rating scores for the seven resistance sources, a new biotype, which caused damage rating scores different from those for RWASA1 and RWASA2, was evident among the Russian wheat aphid populations tested. This new biotype is virulent to the same resistance sources as RWASA2 (Dn1, Dn2, Dn3, and Dn9), but it also has added virulence to Dn4, whereas RWASA2 is avirulent to this resistance source.

Loss of PUMA protects the ovarian reserve during DNA-damaging chemotherapy and preserves fertility.

PubMed

Nguyen, Quynh-Nhu; Zerafa, Nadeen; Liew, Seng H; Morgan, F Hamish; Strasser, Andreas; Scott, Clare L; Findlay, Jock K; Hickey, Martha; Hutt, Karla J

2018-05-23

Female gametes are stored in the ovary in structures called primordial follicles, the supply of which is non-renewable. It is well established that DNA-damaging cancer treatments can deplete the ovarian reserve of primordial follicles, causing premature ovarian failure and infertility. The precise mechanisms underlying this chemotherapy-driven follicle loss are unclear, and this has limited the development of targeted ovarian-protective agents. To address this fundamental knowledge gap, we used gene deletion mouse models to examine the role of the DNA damage-induced pro-apoptotic protein, PUMA, and its transcriptional activator TAp63, in primordial follicle depletion caused by treatment with cyclophosphamide or cisplatin. Cyclophosphamide caused almost complete destruction of the primordial follicle pool in adult wild-type (WT) mice, and a significant destructive effect was also observed for cisplatin. In striking contrast, Puma -/- mice retained 100% of their primordial follicles following either genotoxic treatment. Furthermore, elimination of PUMA alone completely preserved fertility in cyclophosphamide-treated mice, indicating that oocytes rescued from DNA damage-induced death can repair themselves sufficiently to support reproductive function and offspring health. Primordial follicles were also protected in TAp63 -/- mice following cisplatin treatment, but not cyclophosphamide, suggesting mechanistic differences in the induction of apoptosis and depletion of the ovarian reserve in response to these different chemotherapies. These studies identify PUMA as a crucial effector of apoptosis responsible for depletion of primordial follicles following exposure to cyclophosphamide or cisplatin, and this indicates that inhibition of PUMA may be an effective ovarian-protective strategy during cancer treatment in women.

Fungicide Sprays Can Injure the Stigmatic Surface During Receptivity in Almond Flowers

PubMed Central

YI, WEIGUANG; LAW, S. EDWARD; WETZSTEIN, HAZEL Y.

2003-01-01

Fungicides can be detrimental to flower development, pollen function and fruit set in a number of crops. Almond is a self‐incompatible nut crop that has a fruit set of only approx. 30 % of the total number of flowers. Thus, interference of pollination and fertilization by fungicide sprays is of concern, and identification of chemicals having the least detrimental effects would be desirable. The objective of this study was to evaluate the effect of fungicide sprays on stigma morphology in almond using a laboratory spray apparatus that simulated field applications. Four fungicides (azoxystrobin, myclobutanil, iprodione and cyprodinil) were applied, and fresh, unfixed stigmatic surfaces were observed using a scanning electron microscope at 4 and 24 h after spraying. Increased exudate accumulation was induced by azoxystrobin at both time periods, and localized damage and collapse of stigmatic cells were observed after 24 h. Damaged stigmatic papillae exhibited wrinkling, surface distortion or collapse. Likewise, myclobutanil caused significant damage to and collapse of papillae; these were more extensive at later observations. Iprodione had no effect on exudate accumulation but caused marked and severe collapse of stigmatic papillae which was pronounced at 24 h. Cyprodinil promoted a copious increase in exudate secretion and caused the most severe collapse of stigmatic cells of all the fungicides evaluated. Damage was somewhat localized at 4 h but more global at 24 h. This study has verified that certain fungicide sprays have direct detrimental effects on stigma morphology and enhance exudate production in almond flowers. PMID:12547686

3,4-Methylenedioxypyrovalerone prevents while methylone enhances methamphetamine-induced damage to dopamine nerve endings: β-ketoamphetamine modulation of neurotoxicity by the dopamine transporter

PubMed Central

Anneken, John H.; Angoa-Pérez, Mariana; Kuhn, Donald M.

2016-01-01

Methylone, 3,4-methylenedioxypyrovalerone (MDPV), and mephedrone are psychoactive ingredients of ‘bath salts’ and their abuse represents a growing public health care concern. These drugs are cathinone derivatives and are classified chemically as β-ketoamphetamines. Because of their close structural similarity to the amphetamines, methylone, MDPV, and mephedrone share most of their pharmacological, neurochemical, and behavioral properties. One point of divergence in their actions is the ability to cause damage to the CNS. Unlike methamphetamine, the β-ketoamphetamines do not damage dopamine (DA) nerve endings. However, mephedrone has been shown to significantly accentuate methamphetamine neurotoxicity. Bath salt formulations contain numerous different psychoactive ingredients, and individuals who abuse bath salts also coabuse other illicit drugs. Therefore, we have evaluated the effects of methylone, MDPV, mephedrone, and methamphetamine on DA nerve endings. The β-ketoamphetamines alone or in all possible two-drug combinations do not result in damage to DA nerve endings but do cause hyperthermia. MDPV completely protects against the neurotoxic effects of methamphetamine while methylone accentuates it. Neither MDPV nor methylone attenuates the hyperthermic effects of methamphetamine. The potent neuroprotective effects of MDPV extend to amphetamine-, 3,4-methylenedioxymethamphetamine-, and MPTP-induced neurotoxicity. These results indicate that β-ketoamphetamine drugs that are non-substrate blockers of the DA transporter (i.e., MDPV) protect against methamphetamine neurotoxicity, whereas those that are substrates for uptake by the DA transporter and which cause DA release (i.e., methylone, mephedrone) accentuate neurotoxicity. PMID:25626880

Ozone damage detection in cantaloupe plants

NASA Technical Reports Server (NTRS)

Gausman, H. W.; Escobar, D. E.; Rodriguez, R. R.; Thomas, C. E.; Bowen, R. L.

1978-01-01

Ozone causes up to 90 percent of air pollution injury to vegetation in the United States; excess ozone affects plant growth and development and can cause undetected decrease in yields. Laboratory and field reflectance measurements showed that ozone-damaged cantaloupe (Cucumis melo L.) leaves had lower water contents and higher reflectance than did nondamaged leaves. Cantaloupe plants which were lightly, severely, and very severely ozone-damaged were distinguishable from nondamaged plants by reflectance measurements in the 1.35- to 2.5 micron near-infrared water absorption waveband. Ozone-damaged leaf areas were detected photographically 16 h before the damage was visible. Sensors are available for use with aircraft and spacecraft that possibly could be used routinely to detect ozone-damaged crops.

Prophylactic neuroprotective efficiency of co-administration of Ginkgo biloba and Trifolium pretense against sodium arsenite-induced neurotoxicity and dementia in different regions of brain and spinal cord of rats.

PubMed

Abdou, Heba M; Yousef, Mokhtar I; El Mekkawy, Desouki A; Al-Shami, Ahmed S

2016-08-01

The present study was carried out to evaluate the potential protective role of co-administration of Ginkgo biloba, Trifolium pretenseagainst sodium arsenite-induced neurotoxicity in different parts of brain (Cerebral cortex, Hippocampus, striatum and Hind brain) and in the spinal cord of rats. Sodium arsenite caused impairment in the acquisition and learning in all the behavioral tasks and caused significant increase in tumor necrosis factor-α,thiobarbituric acid-reactive substances andlipid profile, while caused significant decrease in glutathione, total thiol content, total antioxidant capacity, acetylcholinesterase, monoamine oxidase and ATPases activities. These results were confirmed by histopathological, fluorescence and scanning electron microscopy examination of different regions of brain. From these results sodium arsenite-induced neurodegenerative disorder in different regions of brain and spinal cord and this could be mediated through modifying the intracellular brain ions homeostasis, cholinergic dysfunction and oxidative damage. The presence of Ginkgo biloba and/orTrifolium pretense with sodium arsenite minimized its neurological damages. It was pronounced that using Ginkgo biloba and Trifolium pretense in combination was more effective as protective agents compared to use eachone of them alone. Copyright © 2016 Elsevier Ltd. All rights reserved.

Molecular genetic evidence for the involvement of a specific polygalacturonase, P2c, in the invasion and spread of Aspergillus flavus in cotton bolls.

PubMed Central

Shieh, M T; Brown, R L; Whitehead, M P; Cary, J W; Cotty, P J; Cleveland, T E; Dean, R A

1997-01-01

Isolates of Aspergillus flavus can be differentiated based on production of the polygalacturonase P2c. One group of isolates produces P2c, whereas the other group does not. In general, the group that produces P2c causes more damage and spreads to a greater extent in cotton bolls than those isolates that do not produce P2c. To determine whether P2c contributes to disease, the expression of pecA, the gene previously determined to encode P2c, was genetically altered. Adding the pecA gene to a strain previously lacking the gene resulted in the ability to cause significantly more damage to the intercarpellary membrane and the ability spread to a greater extent within the adjacent locule compared to the abilities of a control transformant. Conversely, eliminating the expression of pecA by targeted disruption caused a significant reduction in aggressiveness compared to that of a nondisrupted control transformant. These results provide direct evidence that P2c contributes to the invasion and spread of A. flavus during infection of cotton bolls. However, other factors not evaluated in this study also contribute to aggressiveness. PMID:9293005

Chronic exposure to graphene-based nanomaterials induces behavioral deficits and neural damage in Caenorhabditis elegans.

PubMed

Li, Ping; Xu, Tiantian; Wu, Siyu; Lei, Lili; He, Defu

2017-10-01

Nanomaterials of graphene and its derivatives have been widely applied in recent years, but whose impacts on the environment and health are still not well understood. In the present study, the potential adverse effects of graphite (G), graphite oxide nanoplatelets (GO) and graphene quantum dots (GQDs) on the motor nervous system were investigated using nematode Caenorhabditis elegans as the assay system. After being characterized using TEM, SEM, XPS and PLE, three nanomaterials were chronically exposed to C. elegans for 6 days. In total, 50-100 mg l -1 GO caused a significant reduction in the survival rate, but G and GDDs showed low lethality on nematodes. After chronic exposure of sub-lethal dosages, three nanomaterials were observed to distribute primarily in the pharynx and intestine; but GQDs were widespread in nematode body. Three graphene-based nanomaterials resulted in significant declines in locomotor frequency of body bending, head thrashing and pharynx pumping. In addition, mean speed, bending angle-frequency and wavelength of the crawling movement were significantly reduced after exposure. Using transgenic nematodes, we found high concentrations of graphene-based nanomaterials induced down-expression of dat-1::GFP and eat-4::GFP, but no significant changes in unc-47::GFP. This indicates that graphene-based nanomaterials can lead to damages in the dopaminergic and glutamatergic neurons. The present data suggest that chronic exposure of graphene-based nanomaterials may cause neurotoxicity risks of inducing behavioral deficits and neural damage. These findings provide useful information to understand the toxicity and safe application of graphene-based nanomaterials. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Cerebral Visual Impairment: Which Perceptive Visual Dysfunctions Can Be Expected in Children with Brain Damage? A Systematic Review

ERIC Educational Resources Information Center

Boot, F. H.; Pel, J. J. M.; van der Steen, J.; Evenhuis, H. M.

2010-01-01

The current definition of Cerebral Visual Impairment (CVI) includes all visual dysfunctions caused by damage to, or malfunctioning of, the retrochiasmatic visual pathways in the absence of damage to the anterior visual pathways or any major ocular disease. CVI is diagnosed by exclusion and the existence of many different causes and symptoms make…

Later Education Start Times in Adolescence: Time for Change

ERIC Educational Resources Information Center

Kelley, Paul; Lee, Clark

2015-01-01

School start times for adolescents in the United States are typically too early to be healthy for this age group. There is significant evidence from the research literature that early starts have serious negative impacts on students. In particular, early education start times in adolescence cause chronic sleep deprivation, which damages both…

Systematic development of Phytophthora species-specific mitochondrial diagnostic markers for economically important members of the genus

USDA-ARS?s Scientific Manuscript database

The genus Phytophthora contains many invasive species to the USA that have the potential to cause significant damage to agriculture and native ecosystems. A genus and species-specific diagnostic assay was previously reported based on mitochondrial gene order differences that allowed for the systemat...

The invasive Liriomyza huidobrensis (Diptera: Agromyzidae): Understanding its pest status and management globally

USDA-ARS?s Scientific Manuscript database

Liriomyza huidobrensis is native to South America but has expanded its range and invaded many regions of the world, primarily on flowers and to a lesser extent on horticultural product shipments. As a result of initial invasion into an area, damage caused was usually significant but not necessarily...

Development of a sweet cherry pepper line with resistance to the southern root-knot nematode Meloidogyne incognita

USDA-ARS?s Scientific Manuscript database

The southern root-knot nematode (Meloidogyne incognita) is a major pathogen of pepper (Capsicum spp.), causing significant yield losses in heavily infected plants. The N-gene confers resistance to M. incognita, and has been successfully used to mitigate nematode damage in specific pepper varieties f...

Newcastle disease virus fusion and haemagglutinin-neuraminidase proteins contribute to its macrophage host range

USDA-ARS?s Scientific Manuscript database

Newcastle disease virus (NDV) is an avian paramyxovirus that causes significant economic damage to international poultry industry. Different strains of NDV express a wide range of virulence that is primarily dependent on the amino acid sequence of the strain’s fusion (F) protein cleavage site. Two c...

Determining moisture gradient profile using X-Ray technique

Treesearch

Zhiyong Cai

2007-01-01

Moisture gradients in wood are known to affect the internal stresses that could cause dimensional changes and defects. Severe deformation of finished products has the potential to damage a manufacturer’s reputation and significantly increase the cost of manufacturing. An innovative approach to nondestructively examine the moisture gradients of different wood species...

Recovery from Large-Scale Crises: Guidelines for Crisis Teams and Administrators

ERIC Educational Resources Information Center

Communique, 2018

2018-01-01

The United States has recently experienced numerous large-scale crises that resulted in high death tolls and extensive property damage. Critical incidents such as suicide contagion, natural disasters, or mass casualty events have the potential to cause traumatic reactions and significantly affect children's sense of safety and security. School…

Harmful Non-Indigenous Species in the United States.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. Office of Technology Assessment.

Non-indigenous species (NIS) are common in the United States landscape. While some are beneficial, others are harmful and can cause significant economic, environmental, and health damage. This study, requested by the U.S. House Merchant Marine and Fisheries Committee, examined State and Federal policies related to these harmful NIS. The report is…

Determining the Location of DNA Modification and Mutation Caused by UVB Light in Skin Cancer

DTIC Science & Technology

2014-09-01

14 Appendices……………………………………………………………………………14 2 Introduction Ultraviolet ( UV ) light damages skin cells by causing the formation of...dimers on adjacent pyrimidines in DNA. The two main forms of damage caused by UV light are cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts (6...caused by UV damage in tumor suppressor genes such as p53 have been found in the majority of skin cancers. Many studies have focused on these and

Peripheral blood lymphocytes: a model for monitoring physiological adaptation to high altitude.

PubMed

Mariggiò, Maria A; Falone, Stefano; Morabito, Caterina; Guarnieri, Simone; Mirabilio, Alessandro; Pilla, Raffaele; Bucciarelli, Tonino; Verratti, Vittore; Amicarelli, Fernanda

2010-01-01

Depending on the absolute altitude and the duration of exposure, a high altitude environment induces various cellular effects that are strictly related to changes in oxidative balance. In this study, we used in vitro isolated peripheral blood lymphocytes as biosensors to test the effect of hypobaric hypoxia on seven climbers by measuring the functional activity of these cells. Our data revealed that a 21-day exposure to high altitude (5000 m) (1) increased intracellular Ca(2+) concentration, (2) caused a significant decrease in mitochondrial membrane potential, and (3) despite possible transient increases in intracellular levels of reactive oxygen species, did not significantly change the antioxidant and/or oxidative damage-related status in lymphocytes and serum, assessed by measuring Trolox-equivalent antioxidant capacity, glutathione peroxidase activity, vitamin levels, and oxidatively modified proteins and lipids. Overall, these results suggest that high altitude might cause an impairment in adaptive antioxidant responses. This, in turn, could increase the risk of oxidative-stress-induced cellular damage. In addition, this study corroborates the use of peripheral blood lymphocytes as an easily handled model for monitoring adaptive response to environmental challenge.

Endothelium-derived relaxing factor (nitric oxide) has protective actions in the stomach

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacNaughton, W.K.; Wallace, J.L.; Cirino, G.

1989-01-01

The role that nitric oxide, an endothelium-derived relaxing factor, may play in the regulation of gastric mucosal defense was investigated by assessing the potential protective actions of this factor against the damage caused by ethanol in an ex vivo chamber preparation of the rat stomach. Topical application of glyceryl trinitrate and sodium nitroprusside, which have been shown to release nitric oxide, markedly reduced the area of 70% ethanol-induced hemorrhagic damage. Topical application of a 0.01% solution of authentic nitric oxide also significantly reduced the severity of mucosal damage. Pretreatment with indomethacin precluded the involvement of endogenous prostaglandins in the protectivemore » effects of these agents. The protective effects of NO were transient, since a delay of 5 minutes between NO administration and ethanal administration resulted in a complete loss of the protective activity. The protection against ethanol afforded by 10 ug/ml nitroprusside could be completely reversed by intravenous infusion of either 1% methylene blue or 1 mM hemoglobin, both of which inhibit vasodilation induced by nitric oxide. Intravenous infusion of 1% methylene blue significantly increased the susceptibility of the mucosa to damage induced by topical 20% ethanol.« less

No evidence of oxidative stress after a triathlon race in highly trained competitors.

PubMed

Margaritis, I; Tessier, F; Richard, M J; Marconnet, P

1997-04-01

Long distance triathlons, due to the large amounts of oxygen uptake they cause, may lead to the generation of reactive oxygen species, and consequently to oxidative stress and damage. We sought to verify this hypothesis. Twelve of the 18 male triathletes who participated in the study took part in a long distance triathlon, the others did not. The prerace blood samples were drawn 48 h before the race and repeatedly until the fourth day of recovery. The myoglobin concentrations increased immediately after the race. The concentrations of methemoglobin, disulfide glutathione (GSSG), and thiobarbituric reactive substances did not significantly change after the race. Although the race induced an inflammatory response, evidenced by the variations in neopterin concentrations and leukocyte counts, there was no consecutive oxidative stress. The basal GSH values were correlated significantly with cycling training volume (r = 0.55) and VO2max (r = 0.53). Muscle damage can occur without evidence of oxidative stress or oxidative damage. We conclude that the magnitude of the antioxidant defense system enhancement depends on training loads. Because of their training status, the triathletes did not suffer from oxidative damage after they finished the long distance triathlon race.

Effects on Diagnostic Parameters After Removing Additional Synchronous Gear Meshes

NASA Technical Reports Server (NTRS)

Decker, Harry J.

2003-01-01

Gear cracks are typically difficult to diagnose with sufficient time before catastrophic damage occurs. Significant damage must be present before algorithms appear to be able to detect the damage. Frequently there are multiple gear meshes on a single shaft. Since they are all synchronous with the shaft frequency, the commonly used synchronous averaging technique is ineffective in removing other gear mesh effects. Carefully applying a filter to these extraneous gear mesh frequencies can reduce the overall vibration signal and increase the accuracy of commonly used vibration metrics. The vibration signals from three seeded fault tests were analyzed using this filtering procedure. Both the filtered and unfiltered vibration signals were then analyzed using commonly used fault detection metrics and compared. The tests were conducted on aerospace quality spur gears in a test rig. The tests were conducted at speeds ranging from 2500 to 5000 revolutions per minute and torques from 184 to 228 percent of design load. The inability to detect these cracks with high confidence results from the high loading which is causing fast fracture as opposed to stable crack growth. The results indicate that these techniques do not currently produce an indication of damage that significantly exceeds experimental scatter.

DNA damage as a biomarker for assessing the effects of suspended solids on the orange-spotted grouper, Epinephelus coioides.

PubMed

Tse, C Y; Chan, K M; Wong, C K

2010-06-01

In Hong Kong, suspended solids (SS) introduced by dredging and mud disposal activities are a major cause of mass mortality in cage-cultured marine fish. We have used DNA damage in liver cells, as determined by the comet assay, to assess the impact of SS on the orange-spotted grouper Epinephelus coioides. Seabed sediments were collected from a heavily polluted site in Victoria Harbor and two less polluted sites in Port Shelter and Mirs Bay. Sediments from Victoria Harbor contained higher levels of copper (Cu) and polycyclic aromatic hydrocarbons (PAHs) than those from the other sites. In a 10-day experiment, SS from all three sites induced significant increase in comet tail length, but not in percentage (%) tail DNA. In a 20-day experiment, fish exposed to polluted SS from Victoria Harbor exhibited a significant increase in comet tail length after 5 days and % tail DNA after 10 days. After a 10-day recovery period, however, DNA damage was reduced as tail length and % tail DNA returned to control levels. These results suggest that DNA damage measured by the comet assay is a highly sensitive biomarker for assessing the genotoxic effects of SS to marine fish.

Molecular mimicry between Mycobacterium leprae proteins (50S ribosomal protein L2 and Lysyl-tRNA synthetase) and myelin basic protein: a possible mechanism of nerve damage in leprosy.

PubMed

Singh, Itu; Yadav, Asha Ram; Mohanty, Keshar Kunja; Katoch, Kiran; Sharma, Prashant; Mishra, Bishal; Bisht, Deepa; Gupta, U D; Sengupta, Utpal

2015-04-01

Autoantibodies against various components of host are known to occur in leprosy. Nerve damage is the primary cause of disability associated with leprosy. The aim of this study was to detect the level of autoantibodies and lympho-proliferative response against myelin basic protein (MBP) in leprosy patients (LPs) and their correlation with clinical phenotypes of LPs. Further, probable role of molecular mimicry in nerve damage of LPs was investigated. We observed significantly high level of anti-MBP antibodies in LPs across the spectrum and a positive significant correlation between the level of anti-MBP antibodies and the number of nerves involved in LPs. We report here that 4 B cell epitopes of myelin A1 and Mycobacterium leprae proteins, 50S ribosomal L2 and lysyl tRNA synthetase are cross-reactive. Further, M. leprae sonicated antigen hyperimmunization was responsible for induction of autoantibody response in mice which could be adoptively transferred to naive mice. For the first time our findings suggest the role of molecular mimicry in nerve damage in leprosy. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Oxalomalate, a competitive inhibitor of NADP+-dependent isocitrate dehydrogenase, enhances lipid peroxidation-mediated oxidative damage in U937 cells.

PubMed

Yang, Joon-Hyuck; Park, Jeen-Woo

2003-08-01

Membrane lipid peroxidation processes yield products that may react with DNA and proteins to cause oxidative modifications. Cytosolic NADP+-dependent isocitrate dehydrogenase (ICDH) in U937 cells produces NADPH, an essential reducing equivalent for the antioxidant system. The protective role of ICDH against lipid peroxidation-mediated oxidative damage in U937 cells was investigated in control cells pre-treated with oxalomalate, a competitive inhibitor of ICDH. Upon exposure to 2,2'-azobis(2-amidinopropane) hydrochloride (AAPH) to U937 cells, which induces lipid peroxidation in membranes, the viability was lower and the protein oxidation, lipid peroxidation, and oxidative DNA damage, reflected by an increase in 8-hydroxy-2'-deoxyguanosine, were higher in oxalomalate-treated cells as compared to control cells. We also observed the significant increase in the endogenous production of reactive oxygen species, as measured by the oxidation of 2',7'-dichlorodihydrofluorescin, as well as the significant decrease in the intracellular GSH level in oxalomalate-treated U937 cells upon exposure to AAPH. These results suggest that ICDH plays an important role as an antioxidant enzyme in cellular defense against lipid peroxidation-mediated oxidative damage through the removal of reactive oxygen species.

Genotoxicity of waterpipe smoke in buccal cells and peripheral blood leukocytes as determined by comet assay.

PubMed

Al-Amrah, Hadba Jar-Allah; Aboznada, Osama Abdullah; Alam, Mohammad Zubair; ElAssouli, M-Zaki Mustafa; Mujallid, Mohammad Ibrahim; ElAssouli, Sufian Mohamad

2014-12-01

Waterpipe smoke causes DNA damage in peripheral blood leukocytes and in buccal cells of smokers. To determine the exposure effect of waterpipe smoke on buccal cells and peripheral blood leukocytes in regard to DNA damage using comet assay. The waterpipe smoke condensates were analyzed by gas chromatography-mass spectrometry (GC-MS). The study was performed on 20 waterpipe smokers. To perform comet assay on bucaal cells of smokers, 10 µl of cell suspension was mixed with 85 µl of pre-warmed 1% low melting agarose, applied to comet slide and electrophoresed. To analyze the effect of smoke condensate in vitro, 1 ml of peripheral blood was mixed with 10 µl of smoke condensate and subjected for comet assay. The GC-MS analysis revealed the presence of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4on, nicotine, hydroxymethyl furancarboxaldehyde and 3-ethoxy-4-hydroxybenzaldehyde in the smoke condensates. Waterpipe smoking caused DNA damage in vivo in buccal cells of smokers. The tail moment and tail length in buccal cells of smokers were 186 ± 26 and 456 ± 71, respectively, which are higher than control. The jurak and moassel smoke condensates were found to cause DNA damage in peripheral blood leukocytes. The moassel smoke condensate was more damaging. There is wide misconception that waterpipe smoking is not as harmful as cigarette smoking. This study demonstrated that waterpipe smoke induced DNA damage in exposed cells. Waterpipe smokes cause DNA damage in buccal cells. The smoke condensate of both jurak and moassel caused comet formation suggesting DNA damage in peripheral blood leukocytes.

The effects of global climate change on Southeast Asia: A survey of likely impacts and problems of adaptation

NASA Technical Reports Server (NTRS)

Njoto, Sukrisno; Howe, Charles W.

1991-01-01

Study results indicate the likelihood of significant net damages from climate change, in particular damages from sea-level rise and higher temperatures that seem unlikely to be offset by favorable shifts in precipitation and carbon dioxide. Also indicated was the importance of better climate models, in particular models that can calculate climate change on a regional scale appropriate to policy-making. In spite of this potential for damage, there seems to be a low level of awareness and concern, probably caused by the higher priority given to economic growth and reinforced by the great uncertainty in the forecasts. The common property nature of global environment systems also leads to a feeling of helplessness on the part of country governments.

Predicting, examining, and evaluating FAC in US power plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cohn, M.J.; Garud, Y.S.; Raad, J. de

1999-11-01

There have been many pipe failures in fossil and nuclear power plant piping systems caused by flow-accelerated corrosion (FAC). In some piping systems, this failure mechanism maybe the most important type of damage to mitigate because FAC damage has led to catastrophic failures and fatalities. Detecting the damage and mitigating the problem can significantly reduce future forced outages and increase personnel safety. This article discusses the implementation of recent developments to select FAC inspection locations, perform cost-effective examinations, evaluate results, and mitigate FAC failures. These advances include implementing the combination of software to assist in selecting examination locations and anmore » improved pulsed eddy current technique to scan for wall thinning without removing insulation. The use of statistical evaluation methodology and possible mitigation strategies also are discussed.« less

6. 'ROCKFILLED CRIB 350 FEET LONG, REPAIRING DAMAGES CAUSED BY ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. 'ROCK-FILLED CRIB 350 FEET LONG, REPAIRING DAMAGES CAUSED BY FLOODS DURING SEASON OF 1927 TO THE DRY GULCH CANAL HEADING.' 1928 - Irrigation Canals in the Uinta Basin, Duchesne, Duchesne County, UT

Senna occidentalis leaf extract possesses antitrypanosomal activity and ameliorates the trypanosome-induced anemia and organ damage.

PubMed

Ibrahim, M A; Aliyu, A B; Sallau, A B; Bashir, M; Yunusa, I; Umar, T S

2010-05-01

The in vitro and in vivo antitrypanosomal effects of the ethanol extract of Senna occidentalis leaf were investigated. The crude extract exhibited an in vitro activity against Trypanosoma brucei brucei as it completely eliminated parasites' motility within 10 minutes postincubation with 6.66 mg/ml of effective extract concentration. The extract was further used to treat experimentally T. brucei brucei infected rats at concentrations of 100 and 200 mg/kg body weight, beginning on day 5 post infections (p.i.). At the termination of the experiment on Day 11 p.i., the extract significantly (P < 0.05) kept the parasitemia lower than was recorded in the infected untreated rats. All the infected animals developed anemia, the severity of which was significantly (P < 0.05) ameliorated by the extract treatment. The infection caused significant (P < 0.05) increases in serum alanine and aspartate aminotransferases as well as serum urea and creatinine levels. However, treatment of infected animals with the extract significantly (P < 0.05) prevented the trypanosome-induced increase in these biochemical indices. Furthermore, the T. brucei infection caused hepatomegaly and splenomegaly that were significantly (P < 0.05) ameliorated by the extract administration. It was concluded that orally administered ethanol extract of S. occidentalis leaf possessed anti-T. brucei brucei activity and could ameliorate the disease-induced anemia and organ damage.

The effect of melatonin on eye lens of rats exposed to ultraviolet radiation.

PubMed

Anwar, M M; Moustafa, M A

2001-05-01

We investigated the influence of exogenously administered melatonin on adult rats eye lenses exposed to ultraviolet radiation (UV) A and B ranging from 356-254 nm irradiation at 8 microW/cm(2). Rats exposed to this range of UV for 15 min for one week showed a significant (P<0.05) reduction in antioxidant enzymes activities; superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and elevated (P<0.001) lipid peroxidation served as an index of cellular damage by free radicals. UV-radiation significantly (P<0.001) elevated calcium ions (Ca(2+)) and lactate dehydrogenase (LDH) activity in lenses. Depleting animals of their stores of important intracellular antioxidant and elevating lenticular Ca(2+) by UV irradiation, may be the main cause of lens opacification. Melatonin injection with radiation significantly reduced (P<0.05) lipid peroxidation, Ca(2+) and (P<0.001) for LDH. When melatonin was injected after radiation, SOD and GSH-Px enzyme activities increased significantly (P<0.01), and lipid peroxidation, Ca(2+) levels and LDH activities were reduced significantly. Melatonin injection after UV radiation was as effective as melatonin treatment concurrent with UV irradiation. We conclude that melatonin may protect the eye lens from the damaging effects of UV exposure, and its actions protect lens from oxidative stress, elevating Ca(2+) levels, which are considered as an important causes of cataractogenesis.

Immobilization of Dystrophin and Laminin α2-Chain Deficient Zebrafish Larvae In Vivo Prevents the Development of Muscular Dystrophy

PubMed Central

Li, Mei; Arner, Anders

2015-01-01

Muscular dystrophies are often caused by genetic alterations in the dystrophin-dystroglycan complex or its extracellular ligands. These structures are associated with the cell membrane and provide mechanical links between the cytoskeleton and the matrix. Mechanical stress is considered a pathological mechanism and muscle immobilization has been shown to be beneficial in some mouse models of muscular dystrophy. The zebrafish enables novel and less complex models to examine the effects of extended immobilization or muscle relaxation in vivo in different dystrophy models. We have examined effects of immobilization in larvae from two zebrafish strains with muscular dystrophy, the Sapje dystrophin-deficient and the Candyfloss laminin α2-chain-deficient strains. Larvae (4 days post fertilization, dpf) of both mutants have significantly lower active force in vitro, alterations in the muscle structure with gaps between muscle fibers and altered birefringence patterns compared to their normal siblings. Complete immobilization (18 hrs to 4 dpf) was achieved using a small molecular inhibitor of actin-myosin interaction (BTS, 50 μM). This treatment resulted in a significantly weaker active contraction at 4 dpf in both mutated larvae and normal siblings, most likely reflecting a general effect of immobilization on myofibrillogenesis. The immobilization also significantly reduced the structural damage in the mutated strains, showing that muscle activity is an important pathological mechanism. Following one-day washout of BTS, muscle tension partly recovered in the Candyfloss siblings and caused structural damage in these mutants, indicating activity-induced muscle recovery and damage, respectively. PMID:26536238

Accelerated Aging Test for Plastic Scintillator Gamma Ray Detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kouzes, Richard T.

Polyvinyl toluene (PVT) and polystyrene (PS), collectively referred to as “plastic scintillator,” are synthetic polymer materials used to detect gamma radiation, and are commonly used in instrumentation. Recent studies have revealed that plastic scintillator undergoes an environmentally related material degradation that adversely affects performance under certain conditions and histories. A significant decrease in gamma ray sensitivity has been seen in some detectors in systems as they age. The degradation of sensitivity of plastic scintillator over time is due to a variety of factors, and the term “aging” is used to encompass all factors. Some plastic scintillator samples show no agingmore » effects (no significant change in sensitivity over more than 10 years), while others show severe aging (significant change in sensitivity in less than 5 years). Aging effects arise from weather (variations in heat and humidity), chemical exposure, mechanical stress, light exposure, and loss of volatile components. The damage produced by these various causes can be cumulative, causing observable damage to increase over time. Damage may be reversible up to some point, but becomes permanent under some conditions. It has been demonstrated that exposure of plastic scintillator in an environmental chamber to 30 days of high temperature and humidity (90% relative humidity and 55°C) followed by a single cycle to cold temperature (-30°C) will produce severe fogging in all PVT samples. This thermal cycle will be referred to as the “Accelerated Aging Test.” This document describes the procedure for performing this Accelerated Aging Test.« less

Hyperoxia-induced ciliary loss and oxidative damage in an in vitro bovine model: The protective role of antioxidant vitamins E and C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Shmgani, Hanady S.; Moate, Roy M.; Sneyd, J. Robert

2012-12-14

Highlights: Black-Right-Pointing-Pointer A new bovine bronchial model for studying hyperoxia-induced cilia loss is presented. Black-Right-Pointing-Pointer Hyperoxia-induced cilia loss was associated with increased sloughing of cells. Black-Right-Pointing-Pointer Hyperoxia led to higher epithelial glutathione levels, evidence of oxidative stress. Black-Right-Pointing-Pointer Hyperoxia led to increased DNA damage (Comet), and lipid peroxidation (TBARS). Black-Right-Pointing-Pointer Vitamins C and E partially protected against hyperoxia-induced cilia loss. -- Abstract: Although elevated oxygen fraction is used in intensive care units around the world, pathological changes in pulmonary tissue have been shown to occur with prolonged exposure to hyperoxia. In this work a bovine bronchus culture model has beenmore » successfully used to evaluate the effects of hyperoxia on ciliated epithelium in vitro. Samples were cultured using an air interface method and exposed to normoxia, 21% O{sub 2} or hyperoxia, 95% O{sub 2}. Cilial coverage was assessed using scanning electron microscopy (SEM). Tissue damage (lactate dehydrogenase, LDH, in the medium), lipid peroxidation (thiobarbituric acid reactive substances, TBARS), DNA damage (comet assay), protein oxidation (OxyBlot kit) and antioxidant status (total glutathione) were used to assess whether the hyperoxia caused significant oxidative stress. Hyperoxia caused a time-dependent decline (t{sub Vulgar-Fraction-One-Half} = 3.4 d compared to 37.1 d under normoxia) in cilial coverage (P < 0.0001). This was associated with a significant increase in the number of cells (2.80 {+-} 0.27 Multiplication-Sign 10{sup 6} compared to 1.97 {+-} 0.23 Multiplication-Sign 10{sup 6} ml{sup -1} after 6 d), many apparently intact, in the medium (P < 0.05); LDH release (1.06 {+-} 0.29 compared to 0.83 {+-} 0.36 {mu}mol min{sup -1} g{sup -1} after 6 d; P < 0.001); lipid peroxidation (352 {+-} 16 versus 247 {+-} 11 {mu}mol MDA g{sup -1} for hyperoxia and normoxia, respectively); % tail DNA (18.7 {+-} 2.2 versus 11.1 {+-} 1.5); protein carbonyls (P < 0.05); and total glutathione (229 {+-} 20 {mu}mol g{sup -1} versus 189 {+-} 15 {mu}mol g{sup -1}). Vitamins E (10{sup -7} M) and C (10{sup -6} or 10{sup -7} M) alone or in combination (10{sup -7} M and 10{sup -6} M, respectively) had a significant protective effect on the hyperoxia-induced reduction in percentage cilial coverage (P < 0.05). In conclusion, hyperoxia caused damage to cultured bovine bronchial epithelium and denudation of cilia. The antioxidant vitamins E and C significantly protected against hyperoxia-induced cilia loss.« less

Enamel subsurface damage due to tooth preparation with diamonds.

PubMed

Xu, H H; Kelly, J R; Jahanmir, S; Thompson, V P; Rekow, E D

1997-10-01

In clinical tooth preparation with diamond burs, sharp diamond particles indent and scratch the enamel, causing material removal. Such operations may produce subsurface damage in enamel. However, little information is available on the mechanisms and the extent of subsurface damage in enamel produced during clinical tooth preparation. The aim of this study, therefore, was to investigate the mechanisms of subsurface damage produced in enamel during tooth preparation by means of diamond burs, and to examine the dependence of such damage on enamel rod orientation, diamond particle size, and removal rate. Subsurface damage was evaluated by a bonded-interface technique. Tooth preparation was carried out on two enamel rod orientations, with four clinical diamond burs (coarse, medium, fine, and superfine) used in a dental handpiece. The results of this study showed that subsurface damage in enamel took the form of median-type cracks and distributed microcracks, extending preferentially along the boundaries between the enamel rods. Microcracks within individual enamel rods were also observed. The median-type cracks were significantly longer in the direction parallel to the enamel rods than perpendicular to the rods. Preparation with the coarse diamond bur produced cracks as deep as 84 +/- 30 microns in enamel. Finishing with fine diamond burs was effective in crack removal. The crack lengths in enamel were not significantly different when the removal rate was varied. Based on these results, it is concluded that subsurface damage in enamel induced by tooth preparation takes the form of median-type cracks as well as inter- and intra-rod microcracks, and that the lengths of these cracks are sensitive to diamond particle size and enamel rod orientation, but insensitive to removal rate.

Relationships among rat numbers, abundance of oil palm fruit and damage levels to fruit in an oil palm plantation.

PubMed

Puan, Chong Leong; Goldizen, Anne W; Zakaria, Mohamed; Hafidzi, Mohd N; Baxter, Greg S

2011-06-01

The relationships between vertebrate pests and crop damage are often complex and difficult to study. In palm oil plantations rodents remain the major pests, causing substantial monetary losses. The present study examined the numerical and functional responses of rodents to changes in the availability of oil palm fruit and the damage associated with that response. For the study, 200 traps were set in pairs on a 10 × 10 trapping grid for 3 consecutive nights in each of 6 study plots at 8-week intervals in a 2569 ha oil palm plantation at Labu, Negeri Sembilan state in Peninsular Malaysia over 14 months. A total of 1292 individual rats were captured over 25 200 trap-nights. Animals were identified, aged, sexed, weighed and measured. An index of the relative abundance of rats was calculated based on trapping success. Damage to infructescences was assessed at each trap point. Regardless of the age of palms, there were positive and significant relationships between the relative abundance of rats and numbers of infructescences. The levels of damage to infructescences were significantly correlated with the relative abundance of rats. A steep increase in damage was observed with an increase in mature infructescences, indicating a feeding preference of rats for mature infructescences. For both males and females of all rat species, there were weak and non-significant correlations between body condition and infructescence numbers. These results indicated that there was a numerical and a functional response by rats to the availability of palm fruit and a resulting increase in depredation of oil palm fruits. The ways in which this information might aid in future pest control are discussed. © 2011 ISZS, Blackwell Publishing and IOZ/CAS.

Interplay between high energy impulse noise (blast) and antioxidants in the lung.

PubMed

Elsayed, Nabil M; Gorbunov, Nikolai V

2003-07-15

High-energy impulse noise (BLAST) is a physical event characterized by an abrupt rise in atmospheric pressure above ambient lasting for a very short period, but potentially causing significant material and biological damage. Exposure to high-level BLAST can be destructive and lethal. Low-level BLAST similar to what is encountered repeatedly by military personnel during training and combat from detonation of munitions and firing of large caliber weapons, and during occupational use of explosives and some heavy machinery, can also cause significant injury. Globally, civilians are increasingly exposed to BLAST resulting from terrorist bombings or abandoned unmarked mines following numerous wars and conflicts. We have shown previously in several animal models that exposure to non-lethal BLAST results in pathological changes, mostly to the hollow organs characterized in the lungs, the most sensitive organ, by rupture of alveolar septa, and pulmonary hemorrhage and edema. These events potentially can cause alveolar flooding, respiratory insufficiency and adult respiratory distress syndrome (ARDS), leading to varying degrees of hypoxia, antioxidant depletion and oxidative damage. We have also observed progressive formation of nitric oxide in blood and other tissues. The totality of these observations supports our general hypothesis that exposure to BLAST can lead to antioxidant depletion and oxidative damage. Understanding the mechanism(s) of BLAST-induced oxidative stress may have important implications that include a potential beneficial role for antioxidants as a prophylaxis or as secondary treatment of injury after exposure alongside other protective and therapeutic modalities. In addition, it suggests a role for endogenous nitric oxide in the injury. This report reviews experimental evidence of BLAST-induced antioxidant depletion, and the potential benefit from antioxidant supplementation before exposure.

Weak silica nanomaterial-induced genotoxicity can be explained by indirect DNA damage as shown by the OGG1-modified comet assay and genomic analysis.

PubMed

Pfuhler, Stefan; Downs, Thomas R; Allemang, Ashley J; Shan, Yuching; Crosby, Meredith E

2017-01-01

In a previous study, 15-nm silica nanoparticles (NPs) caused small increases in DNA damage in liver as measured in the in vivo comet and micronucleus assays after intravenous administration to rats at their maximum tolerated dose, a worst-case exposure scenario. Histopathological examination supported a particle-induced, tissue damage-mediated inflammatory response. This study used a targeted approach to provide insight into the mode of action (MoA) by examining transcriptional regulation of genes in liver in a time and dose-dependent manner at 1, 2, 4, 8 and 24 h after intravenous administration of 15-nm silica NPs. DNA damage was assessed using the standard comet assay and hOGG1 glycosylase-modified comet assay that also measures oxidative DNA damage. Potassium bromate, an IARC Class 2B carcinogen that specifically operates via an oxidative stress MoA, was used as a positive control for the hOGG1 comet assay and gave a strong signal in its main target organ, the kidney, while showing less activity in liver. Treatment of rats with silica NPs at 50 mg/kg body weight (bw) caused small, statistically insignificant increases in DNA damage in liver measured by the standard comet assay, while a statistically significant increase was observed at 4 h with the hOGG1 comet assay, consistent with a MoA involving reactive oxygen species. Histopathology showed liver damage and neutrophil involvement while genomic analysis and response pattern of key genes involved in inflammation and oxidative stress supported a tissue damage-mediated inflammatory response involving the complement system for removing/phagocytising damaged cells. No changes were observed for histopathology or gene array for the low-dose (5 mg/kg bw) silica NPs. The results of this study confirm our hypothesis that the weak DNA damage observed by silica NPs occurs secondary to inflammation/immune response, indicating that a threshold can be applied in the risk assessment of these materials. © The Author 2016. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Replicative stress and alterations in cell cycle checkpoint controls following acetaminophen hepatotoxicity restrict liver regeneration.

PubMed

Viswanathan, Preeti; Sharma, Yogeshwar; Gupta, Priya; Gupta, Sanjeev

2018-03-05

Acetaminophen hepatotoxicity is a leading cause of hepatic failure with impairments in liver regeneration producing significant mortality. Multiple intracellular events, including oxidative stress, mitochondrial damage, inflammation, etc., signify acetaminophen toxicity, although how these may alter cell cycle controls has been unknown and was studied for its significance in liver regeneration. Assays were performed in HuH-7 human hepatocellular carcinoma cells, primary human hepatocytes and tissue samples from people with acetaminophen-induced acute liver failure. Cellular oxidative stress, DNA damage and cell proliferation events were investigated by mitochondrial membrane potential assays, flow cytometry, fluorescence staining, comet assays and spotted arrays for protein expression after acetaminophen exposures. In experimental groups with acetaminophen toxicity, impaired mitochondrial viability and substantial DNA damage were observed with rapid loss of cells in S and G2/M and cell cycle restrictions or even exit in the remainder. This resulted from altered expression of the DNA damage regulator, ATM and downstream transducers, which imposed G1/S checkpoint arrest, delayed entry into S and restricted G2 transit. Tissues from people with acute liver failure confirmed hepatic DNA damage and cell cycle-related lesions, including restrictions of hepatocytes in aneuploid states. Remarkably, treatment of cells with a cytoprotective cytokine reversed acetaminophen-induced restrictions to restore cycling. Cell cycle lesions following mitochondrial and DNA damage led to failure of hepatic regeneration in acetaminophen toxicity but their reversibility offers molecular targets for treating acute liver failure. © 2018 John Wiley & Sons Ltd.

Comparison of two wild rodent species as sentinels of environmental contamination by mine tailings.

PubMed

Tovar-Sánchez, E; Cervantes, L T; Martínez, C; Rojas, E; Valverde, M; Ortiz-Hernández, M L; Mussali-Galante, P

2012-06-01

Contamination with heavy metals is among the most hazardous environmental concerns caused by mining activity. A valuable tool for monitoring these effects is the use of sentinel organisms. Particularly, small mammals living inside mine tailings are an excellent study system because their analysis represents a realistic approach of mixtures and concentrations of metal exposure. We analyzed metal tissue concentrations and DNA damage levels for comparison between genders of a sentinel (Peromyscus melanophrys) and a nonsentinel (Baiomys musculus) species. Also, the relationship between DNA damage and the distance from the contamination source was evaluated. This study was conducted in an abandoned mine tailing at Morelos, Mexico. Thirty-six individuals from both species at the exposed and reference sites were sampled. Metal concentrations in bone and liver of both species were analyzed by atomic absorption spectrophotometry, and DNA damage levels were assayed using the alkaline comet assay. In general, concentrations of zinc, nickel, iron, and manganese were statistically higher in exposed individuals. A significant effect of the organ and the site on all metal tissue concentrations was detected. Significant DNA damage levels were registered in the exposed group, being higher in B. musculus. Females registered higher DNA damage levels than males. A negative relationship between distance from the mine tailing and DNA damage in B. musculus was observed. We consider that B. musculus is a suitable species to assess environmental quality, especially for bioaccumulable pollutants--such as metals--and recommend that it may be considered as a sentinel species.

Effect of temperature and tree species on damage progression caused by whitespotted sawyer (Coleoptera: Cerambycidae) larvae in recently burned logs.

PubMed

Bélanger, Sébastien; Bauce, Eric; Berthiaume, Richard; Long, Bernard; Labrie, Jacques; Daigle, Louis-Frédéric; Hébert, Christian

2013-06-01

The whitespotted sawyer, Monochamus scutellatus scutellatus (Say) (Coleoptera: Ce-rambycidae), is one of the most damaging wood-boring insects in recently burned boreal forests of North America. In Canada, salvage logging after wildfire contributes to maintaining the timber volume required by the forest industry, but larvae of this insect cause significant damage that reduces the economic value of lumber products. This study aimed to estimate damage progression as a function of temperature in recently burned black spruce (Picea mariana (Miller) Britton, Sterns, and Poggenburg) and jack pine (Pinus banksiana Lambert) trees. Using axial tomographic technology, we modeled subcortical development and gallery depth progression rates as functions of temperature for both tree species. Generally, these rates were slightly faster in black spruce than in jack pine logs. Eggs laid on logs kept at 12 degrees C did not hatch or larvae were unable to establish themselves under the bark because no larval development was observed. At 16 degrees C, larvae stayed under the bark for > 200 d before penetrating into the sapwood. At 20 degrees C, half of the larvae entered the sapwood after 30-50 d, but gallery depth progression stopped for approximately 70 d, suggesting that larvae went into diapause. The other half of the larvae entered the sapwood only after 100-200 d. At 24 and 28 degrees C, larvae entered the sapwood after 26-27 and 21 d, respectively. At 28 degrees C, gallery depth progressed at a rate of 1.44 mm/d. Temperature threshold for subcortical development was slightly lower in black spruce (12.9 degrees C) than in jack pine (14.6 degrees C) and it was 1 degrees C warmer for gallery depth progression for both tree species. These results indicate that significant damage may occur within a few months after fire during warm summers, particularly in black spruce, which highlights the importance of beginning postfire salvage logging as soon as possible to reduce economic losses.

Testing the Effects of dl-Alpha-Tocopherol Supplementation on Oxidative Damage, Total Antioxidant Protection and the Sex-Specific Responses of Reproductive Effort and Lifespan to Dietary Manipulation in Australian Field Crickets (Teleogryllus commodus)

PubMed Central

Archer, C. Ruth; Hempenstall, Sarah; Royle, Nick J.; Selman, Colin; Willis, Sheridan; Rapkin, James; Blount, Jon D.; Hunt, John

2015-01-01

The oxidative stress theory predicts that the accumulation of oxidative damage causes aging. More generally, oxidative damage could be a cost of reproduction that reduces survival. Both of these hypotheses have mixed empirical support. To better understand the life-history consequences of oxidative damage, we fed male and female Australian field crickets (Teleogryllus commodus) four diets differing in their protein and carbohydrate content, which have sex-specific effects on reproductive effort and lifespan. We supplemented half of these crickets with the vitamin E isoform dl-alpha-tocopherol and measured the effects of nutrient intake on lifespan, reproduction, oxidative damage and antioxidant protection. We found a clear trade-off between reproductive effort and lifespan in females but not in males. In direct contrast to the oxidative stress theory, crickets fed diets that improved their lifespan had high levels of oxidative damage to proteins. Supplementation with dl-alpha-tocopherol did not significantly improve lifespan or reproductive effort. However, males fed diets that increased their reproductive investment experienced high oxidative damage to proteins. While this suggests that male reproductive effort could elevate oxidative damage, this was not associated with reduced male survival. Overall, these results provide little evidence that oxidative damage plays a central role in mediating life-history trade-offs in T. commodus. PMID:26783958

In Vitro Studies of Primary Explosive Blast Loading on Neurons

DTIC Science & Technology

2015-09-01

blast but was significantly higher for the triple blast. Membrane permeability was also evaluated by calcein dye . Calcein is normally a membrane...impermeable dye ; however, upon damage to the plasma membrane, leakage of the dye into the cytosol can occur, causing an increase in the fluorescence of the...intensities were significantly higher for the injured cells compared with the control and sham. However, the difference in dye uptake between the singly and

48 CFR 1852.223-75 - Major breach of safety or security.

Code of Federal Regulations, 2010 CFR

2010-10-01

... conditions that can cause death, injury, occupational illness, damage to or loss of equipment or property, or... conditions that can cause death, injury, occupational illness, damage to or loss of equipment or property, or...

Careful: Acetaminophen in Pain Relief Medicines Can Cause Liver Damage

MedlinePlus

... and Fever Reducers Careful: Acetaminophen in pain relief medicines can cause liver damage Share Tweet Linkedin Pin ... ingredient in many over-the-counter and prescription medicines that help relieve pain and reduce fever. More ...

Earthquakes, July-August, 1979

USGS Publications Warehouse

Person, W.J.

1980-01-01

In the United States, on August 6, central California experienced a moderately strong earthquake, which injured several people and caused some damage. A number of earthquakes occurred in other parts of the United States but caused very little damage. 

Earthquakes, May-June 1991

USGS Publications Warehouse

Person, W.J.

1992-01-01

In the United States, a magnitude 5.8 earthquake in southern California on June 28 killed two people and caused considerable damage. Strong earthquakes hit Alaska on May 1 and May 30; the May 1 earthquake caused some minor damage. 

Remote Sensing Techniques for Rapid Assessment of Forest Damage Caused by Catastrophic Climatic Events, NA-TP-01-01

Treesearch

William Ciesla; William Frament; Margaret Miller-Weeks

2001-01-01

Catastrophic climatic events such as hurricanes, tornadoes, and ice storms can cause billions of dollars in damage to infrastructure and personal property, loss of lives, and damage to natural resources. Forests are especially susceptible to these events. The following is a list of recent climatic events in North America that have had devastating effects on forest...

Reducing borer damage in oak regeneration and sawtimber

Treesearch

Jimmy R. Galford

1989-01-01

Borers cause millions of dollars in damaged wood annually to oak stands, and adversely affect the form and vigor of oak regeneration. A moth and four species of beetles cause most of the damage; the carpenterworm moth, the oak timberworm, the red oak borer, the living-beech borer, and the white oak borer. The larvae of these insects chew holes in the wood ranging from...

Pre-slaughter, slaughter and post-slaughter defects of skins and hides at the Sheba Tannery and Leather Industry, Tigray region, northern Ethiopia.

PubMed

Kahsay, Tesfay; Negash, Guesh; Hagos, Yohannes; Hadush, Birhanu

2015-08-21

Skins and hides are perishable resources that can be damaged by parasitic diseases and human error, which result in downgrading or rejection. This study was conducted to identify defect types and to determine their prevalence in pickled sheep and wet blue goat skins and wet blue hides. Each selected skin or hide was examined for defects in natural light and the defects were graded according to established quality criteria in Ethiopian standard manuals. Major defects were captured by digital photography. The major pre-slaughter defects included scratches (64.2%), cockle (ekek) (32.8%), wounds or scars (12.6%), lesions from pox or lumpy skin disease (6.1%), poor substance (5%), branding marks (2.3%) and tick bites (1.5%). The presence of grain scratches in wet blue hides (76.3%) was significantly higher than in pickled sheep (67.2%) and wet blue goat (59.1%) skins. The major slaughter defects included flay cuts or scores, holes, poor pattern and vein marks, with a higher occurrence in wet blue goat skins (28.7%; P < 0.001) than in wet blue hides (22.8%) and pickled sheep skins (11.1%). The most prevalent postslaughter defects were grain cracks (14.9%), hide beetle damage (8%), damage caused by heat or putrefaction (3.7%) and machine-induced defects (0.5%). Grain cracks (27.04%) and hide beetle damage (13.9%) in wet blue goat skins were significantly more common than in wet blue hides and pickled sheep skins. These defects cause depreciation in the value of the hides and skins. Statistically significant (P < 0.001) higher rejection rates were recorded for wet blue hides (82.9%) than for pickled sheep skins (18.3%) and wet blue goat skins (8.5%). Improved animal health service delivery, effective disease control strategies and strong collaboration between stakeholders are suggested to enhance the quality of skins and hides.

Mitochondrial DNA Damage and Diseases.

PubMed

Singh, Gyanesh; Pachouri, U C; Khaidem, Devika Chanu; Kundu, Aman; Chopra, Chirag; Singh, Pushplata

2015-01-01

Various endogenous and environmental factors can cause mitochondrial DNA (mtDNA) damage.  One of the reasons for enhanced mtDNA damage could be its proximity to the source of oxidants, and lack of histone-like protective proteins. Moreover, mitochondria contain inadequate DNA repair pathways, and, diminished DNA repair capacity may be one of the factors responsible for high mutation frequency of the mtDNA. mtDNA damage might cause impaired mitochondrial function, and, unrepaired mtDNA damage has been frequently linked with several diseases. Exploration of mitochondrial perspective of diseases might lead to a better understanding of several diseases, and will certainly open new avenues for detection, cure, and prevention of ailments.

Study of thermal sensitivity and thermal explosion violence of energetic materials in the LLNL ODTX system

NASA Astrophysics Data System (ADS)

Hsu, P. C.; Hust, G.; Zhang, M. X.; Lorenz, T. K.; Reynolds, J. G.; Fried, L.; Springer, H. K.; Maienschein, J. L.

2014-05-01

Incidents caused by fire and combat operations can heat energetic materials that may lead to thermal explosion and result in structural damage and casualty. Some explosives may thermally explode at fairly low temperatures (< 100 °C) and the violence from thermal explosion may cause significant damage. Thus it is important to understand the response of energetic materials to thermal insults. The One Dimensional Time to Explosion (ODTX) system at the Lawrence Livermore National Laboratory has been used for decades to measure times to explosion, threshold thermal explosion temperature, and determine kinetic parameters of energetic materials. Samples of different configurations (pressed part, powder, paste, and liquid) can be tested in the system. The ODTX testing can also provide useful data for assessing the thermal explosion violence of energetic materials. Recent ODTX experimental data are reported in the paper.

One-Dimensional Time to Explosion (Thermal Sensitivity) of ANPZ

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsu, P.; Hust, G.; McClelland, M.

Incidents caused by fire and combat operations can heat energetic materials that may lead to thermal explosion and result in structural damage and casualty. Some explosives may thermally explode at fairly low temperatures (< 100 C) and the violence from thermal explosion may cause a significant damage. Thus it is important to understand the response of energetic materials to thermal insults. The One Dimensional Time to Explosion (ODTX) system at the Lawrence Livermore National Laboratory has been used for decades to measure times to explosion, threshold thermal explosion temperature, and determine kinetic parameters of energetic materials. Samples of different configurationsmore » (pressed part, powder, paste, and liquid) can be tested in the system. The ODTX testing can also provide useful data for assessing the thermal explosion violence of energetic materials. This report summarizes the recent ODTX experimental data and modeling results for 2,6-diamino-3,5-dintropyrazine (ANPZ).« less

Field survey of the March 28, 2005 Nias-Simeulue earthquake and Tsunami

USGS Publications Warehouse

Borrero, J.C.; McAdoo, B.; Jaffe, B.; Dengler, L.; Gelfenbaum, G.; Higman, B.; Hidayat, R.; Moore, A.; Kongko, W.; ,; Peters, R.; Prasetya, G.; Titov, V.; Yulianto, E.

2011-01-01

On the evening of March 28, 2005 at 11:09 p.m. local time (16:09 UTC), a large earthquake occurred offshore of West Sumatra, Indonesia. With a moment magnitude (Mw) of 8.6, the event caused substantial shaking damage and land level changes between Simeulue Island in the north and the Batu Islands in the south. The earthquake also generated a tsunami, which was observed throughout the source region as well as on distant tide gauges. While the tsunami was not as extreme as the tsunami of December 26th, 2004, it did cause significant flooding and damage at some locations. The spatial and temporal proximity of the two events led to a unique set of observational data from the earthquake and tsunami as well as insights relevant to tsunami hazard planning and education efforts. ?? 2010 Springer Basel AG.

Exposure to leachate from municipal battery recycling site: implication as key inhibitor of steroidogenic enzymes and risk factor of prostate damage in rats.

PubMed

Akintunde, Jacob K; Oboh, G

2013-01-01

Few or no studies have measured the effect of short- and long-term exposure to industrial leachate. Mature male Wistar strain albino rats (175-220 g) underwent sub-chronic exposure to leachate from the Elewi Odo municipal battery recycling site (EOMABRL) via oral administration for a period of 60 days at different doses (20%, 40%, 60%, 80%, and 100%) per kilogram of body weight to evaluate the toxic effects of the leachate on male reproductive function using steroidogenic enzymes and biomarkers of prostate damage. Control groups were treated equally but were given distilled water instead of the leachate. After the treatment periods, results showed that the treatment induced systemic toxicity at the doses tested by causing a significant (p<0.05) loss in absolute body weight and decline in growth rate. There was a marked significant decrease (p<0.05) in testicular activities of Δ(5)-3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase. Conversely, the activity of prostatic acid phosphatase, a key marker enzyme for prostrate damage was significantly (p<0.05) elevated in the treated rats. Similarly, the administration of EOMABRL significantly (p<0.05) exacerbated the activity of total acid phosphatase with concomitant increase in the activity of prostatic alkaline phosphatase. These findings conclude that exposure to leachate from a battery recycling site induces sub-chronic testicular toxicity by inhibiting key steroidogenic enzymes and activating key markers linked with prostate damage/cancer in rats.

Matrix metalloproteinase inhibitor attenuates cochlear lateral wall damage induced by intratympanic instillation of endotoxin.

PubMed

Choi, Cheol Hee; Jang, Chul Ho; Cho, Yong Bum; Jo, Si Young; Kim, Min Young; Park, Byung Young

2012-04-01

Oxytetracycline and ilomastat are inhibitors of matrix metalloproteinases (MMPs). Their efficacy in protecting against cochlear damage induced by the intratympanic instillation of lipopolysaccharide (LPS), as a means of inducing labyrinthitis, was investigated. Experiments were performed in 21 young male guinea pigs. Intratympanic instillation of LPS was done in the control group (n=7). Intratympanic instillation of oxytetracycline or ilomastat was done after LPS instillation in the experimental group. Measurements of auditory brainstem response (ABR) and cochlear blood flow (CBF) were performed. The organ of Corti was evaluated by field emission scanning electron microscopy (FE-SEM). The blood-labyrinth barrier (BLB) integrity was evaluated with Evans blue uptake. Gelatin zymography was used to assess the expression of active MMP-2 and MMP-9. Ears treated with MMP inhibitors were significantly protected from hearing loss compared to the LPS group. In LPS group, there was a significant decrease of CBF. However, experimental group displayed a statistically significant recovery of CBF. FE-SEM revealed hair cell damage in the LPS-treated group, but hair cells presented a normal appearance in MMP inhibitors. The LPS group showed a marked increase of Evans blue extravasation in the cochlea. However, MMP inhibitors significantly reduced the BLB opening. Active MMP-9 was expressed in the LPS group. Treatment with MMP inhibitors attenuated active MMP-9 expression. The MMP inhibitors oxytetracycline and ilomastat protect from cochlear lateral wall damage caused by LPS-induced labyrinthitis. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Effect of ozone oxidative preconditioning in preventing early radiation-induced lung injury in rats

PubMed Central

Bakkal, B.H.; Gultekin, F.A.; Guven, B.; Turkcu, U.O.; Bektas, S.; Can, M.

2013-01-01

Ionizing radiation causes its biological effects mainly through oxidative damage induced by reactive oxygen species. Previous studies showed that ozone oxidative preconditioning attenuated pathophysiological events mediated by reactive oxygen species. As inhalation of ozone induces lung injury, the aim of this study was to examine whether ozone oxidative preconditioning potentiates or attenuates the effects of irradiation on the lung. Rats were subjected to total body irradiation, with or without treatment with ozone oxidative preconditioning (0.72 mg/kg). Serum proinflammatory cytokine levels, oxidative damage markers, and histopathological analysis were compared at 6 and 72 h after total body irradiation. Irradiation significantly increased lung malondialdehyde levels as an end-product of lipoperoxidation. Irradiation also significantly decreased lung superoxide dismutase activity, which is an indicator of the generation of oxidative stress and an early protective response to oxidative damage. Ozone oxidative preconditioning plus irradiation significantly decreased malondialdehyde levels and increased the activity of superoxide dismutase, which might indicate protection of the lung from radiation-induced lung injury. Serum tumor necrosis factor alpha and interleukin-1 beta levels, which increased significantly following total body irradiation, were decreased with ozone oxidative preconditioning. Moreover, ozone oxidative preconditioning was able to ameliorate radiation-induced lung injury assessed by histopathological evaluation. In conclusion, ozone oxidative preconditioning, repeated low-dose intraperitoneal administration of ozone, did not exacerbate radiation-induced lung injury, and, on the contrary, it provided protection against radiation-induced lung damage. PMID:23969972

[DNA damage in human pleural mesothelial cells induced by exposure to carbon nanotubes].

PubMed

Ogasawara, Yuki; Umezu, Noriaki; Ishii, Kazuyuki

2012-01-01

Nanomaterials are currently used in electronics, industrial materials, cosmetics, and medicine because they have useful physicochemical properties, such as strength, conductivity, durability, and chemical stability. As these materials have become widespread, many questions have arisen regarding their effects on health and the environment. In particular, recent studies have demonstrated that carbon nanotubes (CNTs) cause significant inflammation and mesothelioma in vivo. In this study, we investigated the potential risk posed by singlewalled carbon nanotube (SWCNT) and multiwalled carbon nanotube (MWCNT) exposure in human pleural mesothelial cells. CNT cytotoxicity was determined by a trypan blue exclusion assay, and DNA damage was detected by an alkaline comet assay. The concentration of 8-oxodeoxyguanosine (8-OHdG) in DNA was measured by high perhormance liquid chromatography with electrochemical detection. The expression of base excision repair enzymes in the cell was estimated by immunoblot analysis. We observed inhibitory effects on cell proliferation and the induction of DNA damage following exposure of cells to purified CNTs that were suspended in dispersion medium. However, accumulation of 8-OHdG in DNA was not found. In addition, the expression levels of base excision enzymes that are involved in hOGG1, hMTH1, and MYH in MeT-5A cells remained unchanged for 24 h after carbon nanotube exposure. CNTs significantly inhibit cell proliferation and decrease DNA damage in human pleural mesothelial cells. Our results indicate that the mechanism of CNT-induced genotoxicity is different from that following exposure to reactive oxygen species, which causes oxidative DNA modifications and 8-OHdG production. Further investigation is required to characterize the specific DNA mutations that occur following CNT exposure.

Increased mitochondrial DNA deletions and copy number in transfusion-dependent thalassemia

PubMed Central

Calloway, Cassandra

2016-01-01

BACKGROUND. Iron overload is the primary cause of morbidity in transfusion-dependent thalassemia. Increase in iron causes mitochondrial dysfunction under experimental conditions, but the occurrence and significance of mitochondrial damage is not understood in patients with thalassemia. METHODS. Mitochondrial DNA (mtDNA) to nuclear DNA copy number (Mt/N) and frequency of the common 4977-bp mitochondrial deletion (ΔmtDNA4977) were quantified using a quantitative PCR assay on whole blood samples from 38 subjects with thalassemia who were receiving regular transfusions. RESULTS. Compared with healthy controls, Mt/N and ΔmtDNA4977 frequency were elevated in thalassemia (P = 0.038 and P < 0.001, respectively). ΔmtDNA4977 was increased in the presence of either liver iron concentration > 15 mg/g dry-weight or splenectomy, with the highest levels observed in subjects who had both risk factors (P = 0.003). Myocardial iron (MRI T2* < 20 ms) was present in 0%, 22%, and 46% of subjects with ΔmtDNA4977 frequency < 20, 20–40, and > 40/1 × 107 mtDNA, respectively (P = 0.025). Subjects with Mt/N values below the group median had significantly lower Matsuda insulin sensitivity index (5.76 ± 0.53) compared with the high Mt/N group (9.11 ± 0.95, P = 0.008). CONCLUSION. Individuals with transfusion-dependent thalassemia demonstrate age-related increase in mtDNA damage in leukocytes. These changes are markedly amplified by splenectomy and are associated with extrahepatic iron deposition. Elevated mtDNA damage in blood cells may predict the risk of iron-associated organ damage in thalassemia. FUNDING. This project was supported by Children’s Hospital & Research Center Oakland Institutional Research Award and by the National Center for Advancing Translational Sciences, NIH, through UCSF-CTSI grant UL1 TR000004. PMID:27583305

Nesfatin-1 alleviates extrahepatic cholestatic damage of liver in rats

PubMed Central

Solmaz, Ali; Gülçiçek, Osman Bilgin; Erçetin, Candaş; Yiğitbaş, Hakan; Yavuz, Erkan; Arıcı, Sinan; Erzik, Can; Zengi, Oğuzhan; Demirtürk, Pelin; Çelik, Atilla; Çelebi, Fatih

2016-01-01

Obstructive jaundice (OJ) can be defined as cessation of bile flow into the small intestine due to benign or malignant changes. Nesfatin-1, recently discovered anorexigenic peptide derived from nucleobindin-2 in hypothalamic nuclei, was shown to have anti-inflammatory and antiapoptotic effects. This study is aimed to investigate the therapeutic effects of nesfatin-1 on OJ in rats. Twenty-four adult male Wistar-Hannover rats were randomly assigned to three groups: sham (n = 8), control (n = 8), and nesfatin (n = 8). After bile duct ligation, the study groups were treated with saline or nesfatin-1, for 10 days. Afterward, blood and liver tissue samples were obtained for biochemical analyses, measurement of cytokines, determination of the oxidative DNA damage, DNA fragmentation, and histopathologic analyses. Alanine aminotransferase and gamma-glutamyl transferase levels were decreased after the nesfatin treatment; however, these drops were statistically non-significant compared to control group (p = 0.345, p = 0.114). Malondialdehyde levels decreased significantly in nesfatin group compared to control group (p = 0.032). Decreases in interleukin-6 and tumor necrosis factor-α levels from the liver tissue samples were not statistically significant in nesfatin group compared to control group. The level of oxidative DNA damage was lower in nesfatin group, however this result was not statistically significant (p = 0.75). DNA fragmentation results of all groups were similar. Histopathological examination revealed that there was less neutrophil infiltration, edema, bile duct proliferation, hepatocyte necrosis, basement membrane damage, and parenchymal necrosis in nesfatin compared to control group. The nesfatin-1 treatment could alleviate cholestatic liver damage caused by OJ due to its anti-inflammatory and antioxidant effects. PMID:27524109

Gamma-ray bursts as a threat to life on Earth

NASA Astrophysics Data System (ADS)

Thomas, B. C.

2009-07-01

Gamma-ray bursts (GRBs) are likely to have made a number of significant impacts on the Earth during the last billion years. The gamma radiation from a burst within a few kiloparsecs would quickly deplete much of the Earth's protective ozone layer, allowing an increase in solar ultraviolet radiation reaching the surface. This radiation is harmful to life, damaging DNA and causing sunburn. In addition, NO2 produced in the atmosphere would cause a decrease in visible sunlight reaching the surface and could cause global cooling. Nitric acid rain could stress portions of the biosphere, but the increased nitrate deposition could be helpful to land plants. We have used a two-dimensional atmospheric model to investigate the effects on the Earth's atmosphere of GRBs delivering a range of fluences, at various latitudes, at the equinoxes and solstices, and at different times of day. We have estimated DNA damage levels caused by increased solar UVB radiation, reduction in solar visible light due to NO2 opacity, and deposition of nitrates through rainout of HNO3. In this paper we give a concise review of this work and discuss current and future work on extending and improving our estimates of the terrestrial impact of a GRB.

ICAM-1 and AMPK regulate cell detachment and apoptosis by N-methyl-N Prime -nitro-N-nitrosoguanidine, a widely spread environmental chemical, in human hormone-refractory prostate cancers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Yi-Cheng; Lu, Pin-Hsuan; Hsu, Jui-Ling

2011-12-15

Poly(ADP-ribose) polymerase-1 (PARP-1), a sensor of DNA damage, plays a crucial role in the regulation of DNA repair. PARP-1 hyperactivation causes DNA damage and cell death. The underlying mechanism is complicated and is through diverse pathways. The understanding of responsible signaling pathways may offer implications for effective therapies. After concentration-response determination of N-Methyl-N Prime -Nitro-N-Nitrosoguanidine (MNNG, a PARP-1 activating agent and an environmental mutagen) in human hormone-refractory prostate cancers, the data showed that concentrations below 5 {mu}M did not change cell survival but cause a time-dependent up-regulation of intracellular adhesion molecule-1 (ICAM-1) in mRNA, total protein and cell surface levels.more » Detection of phosphorylation and degradation of I{kappa}B-{alpha} and nuclear translocation of NF-{kappa}B showed that MNNG induced the activation of NF-{kappa}B that was responsible for the ICAM-1 up-regulation since PDTC (a NF-{kappa}B inhibitor) significantly abolished this effect. However, higher concentrations (e.g., 10 {mu}M) of MNNG induced a 61% detachment of the cells which were apoptosis associated with the activation of AMP-activated protein kinase (AMPK), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). Further identification showed that both AMPK and JNK other than p38 MAPK functionally contributed to cell death. The remaining 39% attached cells were survival associated with high ICAM-1 expression. In conclusion, the data suggest that NF-{kappa}B-dependent up-regulation of ICAM-1 plays a key role on cell attachment and survival; whereas, activation of AMPK and JNK participates in cytotoxic signaling pathways in detached cells caused by PARP-1 activation. Highlights: Black-Right-Pointing-Pointer Low level of DNA damage helps cell attachment and survival via ICAM-1 upregulation. Black-Right-Pointing-Pointer High level of DNA damage causes AMPK- and JNK-involved cell detachment and death. Black-Right-Pointing-Pointer The study provides an anticancer approach targeting PARP-1 and DNA damage response.« less