A one-dimensional analytical model for airborne contaminant transport in airliner cabins

Quick information on airborne infectious disease transmission in airliner cabins is essential to reduce the risk of infection of passengers and crew members. This investigation proposed a one-dimensional analytical model that can predict the longitudinal transmission of airborne contaminants or disease viruses inside an airliner cabin. The model considered both diffusive and convective transport of contaminants in the longitudinal direction of the cabin but assumed complete mixing of contaminants in the cabin cross-section. The effect of recirculation of the cabin air and efficiency of the high-efficiency particulate air (HEPA) filters is also considered in the model. The analytical solution for the one-dimensional contaminant transport model is obtained by using the principle of superposition and the method of separation of variables. The analytical solutions agree well with the computational fluid dynamics (CFD) results. The coupling of a CFD model with the one-dimensional analytical model could capture the impact of local airflow on contaminant transport. This analytical model has been used for analyzing contaminant transport in a 30-row all-economy-class airliner cabin with minimal computing effort.

PRACTICAL IMPLICATIONS

The paper presents a new one-dimensional analytical model that can provide quick information on global airborne contaminant transmissions in airliner cabins for effective response plans. The model can be used to study the effects of air exchange rates, recirculation, efficiency of the high-efficiency particulate air (HEPA) filters and longitudinal airflow on airborne contaminant transport in airliner cabins with minimal computing effort.

The role of P-glycoprotein/cellular prion protein interaction in multidrug-resistant breast cancer cells treated with paclitaxel

We previously reported that treatment with P-glycoprotein (P-gp) substrates promotes in vitro invasion in multidrug-resistant (MDR) breast cancer cells. This effect is initiated by the P-gp pump function and mediated by interaction of P-gp with some unknown component(s). However, the underlying mechanism(s) remains poorly understood. Here we confirm a novel physical interaction between P-gp and cellular prion protein (PrP(c)). Blocking P-gp activity or depletion of PrP(c) inhibited paclitaxel (P-gp substrate)- induced invasion. Paclitaxel further facilitated the formation of P-gp/PrP(c) clusters residing in caveolar domains and promoted the association of P-gp with caveolin-1. Both caveolin-1 and the integrity of caveolae were required for the drug-induced invasion. In addition, the P-gp/PrP(c) complex also played an important role in anti-apoptotic activity of MCF7/Adr cells.These data provide new insights into the mode by which MDR breast cancers evade cytotoxic attacks from P-gp substrates and also suggest a role for P-gp/ PrP(c) interaction in this process.

Length control and sharpening of carbon nanotube scanning probe microscope tips using carbon nanotube "nanoknife"

Through nanomanipulation inside scanning electron microscope, a carbon nanotube scanning probe microscope tip was made by connecting a carbon nanotube with a silicon atomic force microscope tip. The carbon nanotube scanning probe microscope tip was then tailored to the desired length and end structure by a "nanoknife" which is a carbon nanotube adhered to a metal tip. Through mapping the same carbon nanotube on SiO2 substrate, it was found that the lateral resolution of the carbon nanotube tips can be improved significantly through sharpening the tip ends, and the sharpened carbon nanotube tips had better performance than commercial silicon tips.

Real-time or faster-than-real-time simulation of airflow in buildings

Real-time flow simulation is crucial for emergency management in buildings, such as fire and accidental or intentional release of chemical/biological agents (contaminants). The simulation results can then be used to impose proper measures to minimize casualties. Computational fluid dynamics (CFD) is accurate, but too time-consuming. Nodal models are fast, but not informative. To obtain a quick and informative solution, this study proposes an intermediate approach between nodal models and CFD by introducing a fast fluid dynamics (FFD) method. This investigation used the FFD methods with and without turbulence treatments to study systematically four basic flows in buildings, and compared the numerical results with the corresponding CFD results and the data from the literature. The results show that, on one hand, the FFD can offer much richer flow information than nodal models, but less accurate results than CFD. On the other hand, the FFD is 50 times faster than the CFD. The results also show that the FFD with the laminar assumption has the best overall performance as regards both accuracy and speed. It is possible to conduct faster-than-real-time flow simulations with detailed flow information by using the FFD method.

PRACTICAL IMPLICATIONS

The paper introduces a fast fluid dynamics (FFD) method, which can simulate airflow and contaminant dispersion in buildings with real-time or faster-than-real-time speed and provide informative solutions. As an intermediate approach between nodal models and the computational fluid dynamics (CFD), the FFD can be a very useful tool for emergency management in case of fire and accidental or intentional release of chemical or biological agents in a building or around the buildings. The FFD can also be used as a preliminary test tool for quick assessment of indoor airflows before a detailed CFD analysis.

528. THE INTERNALIZATION OF ANTIPHOSPHOLIPID ANTIBODIES INTO TROPHOBLASTS CORRELATES WITH THE EXPRESSION OF MEGALIN

Antiphospholipid antibodies (aPL) are autoantibodies that increase the risk of preeclampsia nine fold. We have recently shown aPL increase in the number of syncytial knots shed from placental explants and also change the trophoblast death process towards necrosis. Shedding of necrotic syncytial knots is thought to contribute to the pathogenesis of preeclampsia. Antiphospholipid antibodies but not control antibodies, are internalised into the syncytiotrophoblast suggesting a specific mechanism for internalisation of the aPL. Megalin is known to be an endocytic receptor for the antigen of aPL. We believe that the internalisation of aPL into the syncytiotrophoblast is required to for aPL to affect trophoblast shedding and in this study began to investigate the hypothesis that megalin mediates aPL-internalisation. Monoclonal aPL, IIC5 or ID2, were incubated with monolayers of the trophoblast cell lines, Jar, Jeg 3 or BeWo, or first trimester placental explants for 24 hours. Internalisation of aPL into trophoblasts was determined by fluorescent immuno-staining as was the expression of megalin using an antimegalin antibody (Sigma). Experiments were repeated at least three times. Confocal microscopy demonstrated that the syncytiotrophoblast of explants and BeWo cells, but not Jar or Jeg3 cells, internalised the aPL. Despite treating explants and BeWos with the same amount of aPL the level of aPL internalised by the syncytiotrophoblast of explants was greater than the level internalised by BeWos. Megalin was expressed strongly by the syncytiotrophoblast and weakly by BeWos but was not expressed by Jars or Jeg3 cells. The internalization of aPL into syncytiotrophoblasts may play an important role in regulating trophoblast death leading to aberrant shedding of syncytial knots. This study provides preliminary evidence that megalin expression correlates with the ability of trophoblasts to internalize aPL suggesting it may be the receptor that mediates aPL internalization into trophoblasts making this pathway a potential therapeutic target.

106. IL-6 INCREASES THE SHEDDING OF NECROTIC TROPHOBLASTS FROM PLACENTAL EXPLANTS

Preeclampsia (PE) is characterised by elevated maternal blood pressure, preceded by endothelial cell dysfunction. Dead trophoblasts, shed from the placenta may be one of the factors that trigger PE. Women with PE frequently have elevated serum levels of inflammatory markers such as, IL-6 and TNF a but their functional significance is unclear. In this study we investigated whether these or other cytokines can alter trophoblast shedding from placental explants. Placental explants were treated with 9 different cytokines for 72 hours. Shed trophoblasts then were harvested using our published method1. The numbers of trophoblasts shed were quantified by automated cell counter. Expression of active of caspases 3&7 by the shed trophoblasts was determined using a FLICA kit. The trophoblasts shed from cytokine-treated or control explants were exposed to endothelial cell monolayers and endothelial activation determined by ELISA for cell surface ICAM-1. Treatment of explants with IL-6 caused a 50% increase (p=0.001), while TNF a and TGF b 1, caused smaller significant increases in the numbers of trophoblasts shed. Trophoblasts shed from explants treated with IL-6, TGF b 1, or TGF b 3 expressed significantly less active caspases 3&7 than controls or trophoblasts shed from explants treated with other cytokines. Exposing trophoblasts shed from IL-6- or TGF b 1-treated explants to endothelial cells caused a significant (P<0.001) increase in endothelial activation. Normally trophoblasts shed from the placenta die by an apoptosis-like process and their phagocytosis by endothelial cells is silent but a shift to shedding of necrotic trophoblasts can lead to endothelial cell activation 2. However, it remains unclear what might trigger a shift from apoptotic to necrotic trophoblast death. This study suggests that IL-6 and possibly other cytokines can alter both the number and the nature of shed trophoblasts such that the trophoblast are more necrotic and their phagocytosis by maternal endothelial cells could contribute to the pathogenesis of preeclampsia.

Lead in housing paints: an exposure source still not taken seriously for children lead poisoning in China

After prohibitions on lead gasoline additives, which have proved to be a public health accomplishment world wide, many countries focus on other exposure source of children lead poisoning. Removing lead from paints is one of the important measures. Although there have been regulatory limits on lead in paints in China, evidence reported in this article indicates that lead-based paints were very common in new paints available for housing and in existing residential paints. Twenty-nine of 58 new paint samples (50%) had lead content equal to or exceeding 600 ppm, including 14 (24%) equal to or exceeding 5000 ppm. The highest sample contained 153,000 ppm lead, about 15% of the paint weight. Thirty-two new paints (55%) contained "soluble" lead exceeding 90 ppm, the current lead limit on paints in China. Of the existing paints, 16 of 28 samples of existing paint (57%) collected from 24 kindergartens and primary schools had lead concentrations equal to or exceeding 600 ppm, including six samples (21%) equal to or exceeding 5000 ppm. The highest concentration sample contained 51,800 ppm lead, accounting for 5.2% of the paint weight. It has been shown in many areas that paint lead is a major exposure source for lead poisoning in children. This is particularly true after the phasing out of lead from gasoline. Effective limitation on lead content in new paint, and lead hazard control measures directed towards existing paint, could reduce children blood lead levels (BLLs). There has been a lead standard for paints in China since 1986 and a stricter limit was introduced in recent years. Governments should take it seriously and enforce regulations, commit a long-term challenge to eliminate paint lead as it is the threat to current and the next generation.

Improving strategies for syphilis control in China: selective testing of sexually transmitted disease patients--too little, too late?

SUMMARY

Syphilis testing guidelines in China are usually based on symptomatic criteria, overlooking risk assessment and ultimately opportunities for disease detection and control. We used data from 10,695 sexually transmitted disease (STD) clinic patients in Guangxi, China, to assess the efficacy of a potential screening tool inquiring about behavioural and health risk factors in identifying the STD patients who should not be triaged for syphilis testing under current guidelines, but on the contrary receive such testing. Validity testing of the screening tool was performed and receiver-operating characteristic curves were plotted to determine an optimal total risk score cut-off for testing. About 40.9% of patients with positive toluidine red unheated serum test and Treponema pallidum particle agglutination test did not show hallmark signs of syphilis. The screening tool was more sensitive in detecting infection in non-triaged male versus female patients (highest sensitivity = 90% vs. 55%) and the cut-off score to warrant testing was lower in non-triaged female patients than in non-triaged male patients (cut-off = 1 vs. 2). Most of the cases were missed among female STD patients. In spite of selective testing based on behavioural and health indicators that improve case detection, cases were still missed. Our study supports universal testing for syphilis in the STD population.

Correlation between adiponectin polymorphisms and non-alcoholic fatty liver disease with or without metabolic syndrome in Chinese population

BACKGROUND

To investigate the effect of single nucleotide polymorphisms (SNP) 45 and 276 of the adiponectin gene on non-alcoholic fatty liver disease (NAFLD) with or without metabolic syndrome.

METHODS

A total of 165 NAFLD, 83 NAFLD with metabolic syndrome and 160 healthy controls from Chinese population were genotyped for the adiponectin gene (+45T>G and +276G>T) by PCR-restriction fragment length polymorphism methods. Plasma adiponectin and insulin levels were determined by enzyme-linked immunosorbent assay and radioimmunoassay, respectively. Insulin resistance (IR) was evaluated by using homeostasis model assessment of IR (HOMA-IR).

RESULTS

NAFLD with metabolic syndrome had further extent of IR and hypoadiponectinemia. No association of SNP45 or SNP276 was found in NAFLD or NAFLD with metabolic syndrome. Subjects carrying the G allele of SNP45 showed higher levels of triglyceride (TG), fasting blood sugar (FBS), HOMA, body mass index (BMI), and alanine transaminase (ALT), as well as lower plasma adiponectin levels. In the normal-weight group of SNP276, subjects carrying the G allele showed higher HOMA and subjects carrying the T allele showed lower BMI.

CONCLUSIONS

Our study observed further hypoadiponectinemia and IR in NAFLD with metabolic syndrome. The T45G and G276T of the adiponectin gene may not be the important determinants of NAFLD in Chinese people, but some of them still influence serum ALT, BMI, IR, lipid, glucose metabolism and plasma adiponectin concentration.

Association study of CSF2RB with schizophrenia in Irish family and case - control samples

Colony stimulating factor 2 receptor, beta (CSF2RB) is the shared subunit of receptors for interleukin 3 (IL3), colony stimulating factor 2 (CSF2) and IL5, and is responsible for the initiation of signal transduction triggered by ligand binding. In our previous study, we showed the evidence that the IL3 gene is associated with schizophrenia and the associations observed are sex-specific and dependent on family history (FH). In this article, we studied 10 single-nucleotide polymorphisms in the CSF2RB gene in the Irish Study of High-Density Schizophrenia Families (ISHDSF) and the Irish Case - Control Study of Schizophrenia (ICCSS), and tested allele and haplotype associations with schizophrenia. Using the pedigree disequilibrium test, we found that two markers (rs11705394 and rs7285064) reached nominal significance. In sex-stratified analyses, for both the markers the association signals were mainly derived from male subjects. In the ICCSS sample, we found that several markers (rs2072707, rs2284031 and rs909486) showed sex-specific and FH-dependent associations with schizophrenia. In multimarker haplotype analyses, both ISHDSF and ICCSS samples showed globally significant associations in multiple linkage disequilibrium (LD) blocks sharing minimal LD. Since CSF2RB is essential for IL3 signaling, the findings that both IL3 and CSF2RB showed sex-specific and FH-dependent associations suggest that the IL3 pathway is involved in schizophrenia.

Localized inflammation in peripheral tissue signals the CNS for sickness response in the absence of interleukin-1 and cyclooxygenase-2 in the blood and brain

The CNS can be activated by both local and systemic inflammation, resulting in the manifestation of sickness symptoms. The pathways by which the CNS is activated under these two conditions, however, may differ. In this study, we injected casein into the peritoneal cavity (i.p.) or into an s.c. air pouch of mice to induce restricted local inflammation. Both routes of casein injection caused fever and reduced locomotor activity. These responses were not accompanied by the statistically significant induction of the inflammatory cytokine interleukin-1 (IL-1) in the blood and brain. Further, these responses were produced without the induction of brain cyclooxygenase-2 (COX-2), which has been implicated as an obligatory step in systemic inflammation-induced activation of the CNS. Induction of IL-1, interleukin-6 (IL-6), and COX-2, however, was found consistently at the sites of casein injection. The local inflammation-induced febrile and locomotor activity responses were blunted in animals deficient in functional Toll-like receptor 4 (TLR4), type I interleukin-1 receptor (IL-1R1), IL-6, or COX-2. Therefore, the observed febrile and locomotor activity effects appear to require local, but not central, IL-1, IL-6, and COX-2. These findings suggest that local inflammation can activate the CNS via pathways distinguishable from those mediating systemic inflammation-induced CNS activation.

Specific PCR assays for the identification of common anisakid nematodes with zoonotic potential

Based on the sequences of the internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA (rDNA) for six taxa of anisakids, namely, Anisakis simplex (s.s.), Anisakis typica, Anisakis pegreffii, Hysterothylacium aduncum, Hysterothylacium sp, and Contracaccum osculatum C, specific primers were designed in the ITS-1 and/or ITS-2 for each of the six anisakid taxa. These specific primers were used to develop polymerase chain reaction (PCR) tools for the identification of these anisakid taxa of sea fish by amplifying partial ITS-1 and/or ITS-2 of rDNA from anisakid nematodes. This approach allowed their specific identification, with no amplicons being amplified from heterogeneous DNA samples, and sequencing confirmed the identity of the DNA fragments amplified. The minimum amounts of DNA detectable using the PCR assays were 0.5-1 ng. These PCR tools were then applied to ascertain the specific identity of 143 anisakid larval samples collected from fish in China, Canada, Thailand, and Indonesia, and these anisakid samples were identified to represent one of the six anisakid taxa. These PCR assays based on ITS sequences should provide useful molecular tools for the accurate identification and molecular epidemiological investigations of anisakid infections in humans and fish.

Endogenous hydrogen sulfide is involved in regulation of respiration in medullary slice of neonatal rats

The purpose of the present study was to verify our assumption that rhythmic respiratory activity may be regulated by endogenous hydrogen sulfide (H(2)S) in the medullary slices of neonatal rats. We found that a moderate concentration of donor of H(2)S, NaHS, mainly induced diphasic respiratory responses indicated by changes of discharge frequency (DF) of hypoglossal rootlets, an initial inhibitory stage followed by a later excitatory one. Cystathionine beta-synthase (CBS) substrate, cysteine (CYS), exerted similar effects. CBS inhibitor, NH(2)OH, could eliminate both inhibitory and excitatory effects in the two stages induced by CYS. K(ATP) channel blocker, glibenclamide (Gl), could eliminate the decrease in DF in the initial stage, but not the increase in the later one. On the other hand, adenyl cyclase (AC) inhibitor, SQ-22536 (SQ) could eliminate the increase in DF in the later stage, but not the decrease in the initial one, of the rootlets caused by NaHS. Co-application of Gl and SQ eliminated both inhibitory and excitatory effect induced by NaHS. The cAMP level was increased in the later stage but not in the initial one by NaHS, and the increase in the cAMP level could be eliminated by SQ. It can be concluded that the endogenous H(2)S could be produced through the CBS-H(2)S pathway and could be involved in the control of the central rhythmic respiration in the in vitro medullary slices of neonatal rats by opening K(ATP) channels and activating AC-cAMP pathway of the neurons.