[Incidence of hypogammaglobulinaemia in children with steroid-dependent/frequently relapsing nephrotic syndrome treated with rituximab and its association with severe infections].

Objective: To investigate the incidence and influencing factors of hypogammaglobulinemia (HGG) in children with steroid-dependent/frequently relapsing nephrotic syndrome (SDNS/FRNS) treated with rituximab (RTX), and its relationship with the risk of severe infections. Methods: The clinical data of children with SDNS/FRNS treated with RTX at the Department of Pediatrics of the First Affiliated Hospital of Zhengzhou University from December 2020 to January 2023 were retrospectively analyzed. RTX treatment was performed using a B-cell-guided regimen (a single dose of 375 mg/m2, a maximum of 500 mg/dose, and an additional one dose when reassessment of peripheral blood CD19+B cells≥1%). Patients were divided into HGG and non-HGG groups according to the presence or absence of HGG during the follow-up period. A multivariate logistic regression model was used to analyze the influencing factors of HGG, and the predictive value of each influencing factor on HGG was assessed by plotting the receiver operating characteristic (ROC) curve. Results: A total of 59 SDNS/FRNS children (48 males and 11 females) were included, and aged [M (Q1, Q3)] 9.4 (6.5, 12.2) years at the time of the first RTX treatment, with a median application of 3 (2, 4) doses of RTX. During the follow-up period of 15.5 (9.9, 22.8) months, the HGG was present in 16 (27.1%) children, of which seven persisted for more than 1 year. Compared with non-HGG group, HGG group had a shorter duration of the disease [3.3 (2.1, 3.6) vs 4.6 (2.4, 8.0) years, P=0.030], younger age at the time of the first RTX treatment [6.2 (5.6, 7.4) vs 11.3 (8.8, 13.3) years, P<0.001], and lower serum IgG levels [5.9 (4.9, 6.4) vs 7.5 (6.1, 8.2) g/L, P<0.001]. Multivariate logistic regression analysis showed that young age at the time of the first RTX treatment (OR=0.52, 95%CI: 0.35-0.78, P=0.002) was an influencing factor of HGG. The area under the curve (AUC) for age at first RTX treatment to predict HGG was 0.887 (95%CI: 0.778-0.955, P<0.001), with an optimal cut-off value of 8.3 years. During the follow-up period, six children (10.2%) developed severe infectious, and there was no statistically significant difference in the incidence of serious infections between the HGG and non-HGG groups [12.5% (2/16) vs 9.3% (4/43), P=1.000]. Conclusions: HGG is frequent in children with SDNS/FRNS treated with RTX, and nearly half of HGG persists for more than 1 year. The possibility of HGG is greater in those≤8.3 years at the first RTX treatment, but HGG does not increase the risk of severe infections in children.

[Long-term outcomes of childhood steroid-sensitive nephrotic syndrome].

Objective: To investigate the long-term outcomes and risk factors in children with steroid-sensitive nephrotic syndrome (SSNS). Methods: A retrospective cohort study was conducted on newly onset SSNS admitted to the Department of Pediatrics of the First Affiliated Hospital of Sun Yat-sen University from January 2006 to December 2010 and 105 cases with follow-up for more than 10 years were included. Clinical data including general characteristics, clinical manifestation, laboratory tests, treatment and prognosis. The primary outcome was the clinical cure, and the secondary outcomes were relapse or ongoing immunosuppressive treatment within the last 1 year of follow-up and complications at the last follow-up. According to the primary outcome, the patients were divided into clinical cured group and uncured group. Categorical variables were compared between 2 groups using the χ2 or Fisher exact test, and continuous variables by t or Mann-Whitney U test. Multiple Logistic regression models were used for multivariate analysis. Results: Of the 105 children with SSNS, the age of onset was 3.0 (2.1, 5.0) years, and 82 (78.1%) were boys, 23(21.9%) were girls. The follow-up time was (13.1±1.4) years; 38 patients (36.2%) had frequently relapsing or steroid-dependent nephrotic syndrome (FRNS or SDNS) and no death or progression to end-stage kidney disease. Eighty-eight patients (83.8%) were clinically cured. Seventeen patients (16.2%) did not reach the clinical cure criteria, and 14 patients (13.3%) had relapsed or ongoing immunosuppressive treatment within the last year of follow-up. The proportion of FRNS or SDNS (12/17 vs. 29.5% (26/88), χ2=10.39), the proportion of treatment with second-line immunosuppressive therapy (13/17 vs. 18.2% (16/88), χ2=21.39), and the level of apolipoprotein A1 at onset ((2.0±0.5) vs. (1.7±0.6) g/L, t=2.02) in the uncured group were higher than those in the clinical cured group (all P<0.05). Multivariate Logistic regression analysis showed that patients treated with immunosuppressive therapy had an increased risk of not reaching clinical cure in the long term (OR=14.63, 95%CI 4.21-50.78, P<0.001). Of the 55 clinically cured patients who had relapsed, 48 patients (87.3%) did not relapse after 12 years of age. The age at last follow-up was 16.4 (14.6, 18.9) years, and 34 patients (32.4%) were ≥18 years of age. Among the 34 patients who had reached adulthood, 5 patients (14.7%) still relapsed or ongoing immunosuppressive treatment within the last year of follow-up. At the last follow-up, among the 105 patients, 13 still had long-term complications, and 8 patients were FRNS or SDNS. The proportion of FRNS or SDNS patients with short stature, obesity, cataracts, and osteoporotic bone fracture was 10.5% (4/38), 7.9% (3/38), 5.3% (2/38), and 2.6% (1/38), respectively. Conclusions: The majority of SSNS children were clinically cured, indicating a favorable long-term prognosis. History of treatment with second-line immunosuppressive therapy was the independent risk factor for patients not reaching the clinical cure criteria in the long term. While it is not uncommon for children with SSNS to persist into adulthood. The prevention and control of long-term complications of FRNS or SDNS patients should be strengthened.

Mixture effect assessment applying in vitro bioassays to in-tissue silicone extracts of traditional foods prepared from beluga whale blubber.

We complement an earlier study on the nutrient and environmental contaminant levels in Arctic beluga whale traditional foods by mixture effect assessment using in vitro bioassays. Mixtures were extracted by in-tissue sampling of raw blubber and several traditional food preparations including Muktuk and Uqsuq using silicone (polydimethylsiloxane, PDMS) as sampler. PDMS extracts persistent and degradable neutral organic chemicals of a wide range of hydrophobicity with defined lipid-PDMS partition ratios. The solvent extracts of PDMS were dosed in various reporter gene assays based on human cell lines. Cytotoxicity was consistent across all cell lines and was a good indicator of overall chemical burden. No hormone-like effects on the estrogen receptor, the progesterone receptor and the glucocorticoid receptor were observed but a few samples activated the androgen receptor, albeit with low potency. The peroxisome-proliferator activated receptor (PPARγ) was the most sensitive endpoint followed by activation of oxidative stress response and activation of the arylhydrocarbon (AhR) receptor. The detected pollutants only explained a small fraction of the experimental mixture effects, indicating additional bioactive pollutants. The effect levels of the extracted mixtures were higher than those observed in blubber extracts of dugongs living off the shore of Australia. Roasting over an open fire or food preparation near a smokehouse led to increased PAH levels that were reflected in increased oxidative stress response and activation of the AhR. So far in vitro assays have only been used to quantify persistent dioxin-like chemicals in food and feed but this pilot study demonstrates a much broader potential for food safety evaluations complementing chemical analytical monitoring.

[Observation on the clinical outcomes of continued pregnancy following cesarean scar pregnancy in 55 women].

Objective: To observe the clinical outcomes of continued pregnancy in pregnant women with cesarean scar pregnancy (CSP). Methods: A retrospective analysis was performed on the pregnancy outcomes of 55 pregnant women who were diagnosed with CSP at the Second Affiliated Hospital of Army Medical University during the first trimester of pregnancy from August 1st, 2018 to October 31st, 2021 and strongly requested to continue the pregnancy. Results: Of the 55 pregnant women, 15 terminated the pregnancy in the first trimester, 1 underwent hysterotomy at 23 weeks of gestation due to cervical dilation, and 39 (71%, 39/55) continued pregnancy to the third trimester achieving live births via cesarean section. The gestational age of the 39 pregnant women delivered by cesarean section was 35+6 weeks (range: 28+5-39+2 weeks), of whom 7 cases at 28+5-33+6 weeks, 20 cases at 34-36+6 weeks, and 12 cases at 37-39+2 weeks. The results of pathological examination were normal placenta in 3 cases (8%, 3/39), placenta creta in 4 cases (10%, 4/39), placenta increta in 9 cases (23%, 9/39) and placenta percreta in 23 cases (59%, 23/39). Among the 36 pregnant women who were pathologically confirmed as placenta accreta spectrum disorders (PAS) after surgery, the last prenatal ultrasonography showed placenta previa in 27 cases (75%, 27/36) and not observed placenta previa in 9 cases. The median intraoperative blood loss, autologous blood transfusion, and allogeneic suspended red blood cell infusion of 39 pregnant women during cesarean section were 1 000 ml (300-3 500 ml), 300 ml (0-2 000 ml) and 400 ml (0-2 400 ml), respectively. The uterine preservation rate was 100% (39/39), and only 1 case received cystostomy due to intracystic hemorrhage. The birth weight of the newborn was 2 580 g (1 350-3 800 g), and 1 case of mild asphyxia. Conclusions: Pregnant women with CSP who continue pregnancy under close monitoring after adequate ultrasound evaluation and doctor-patient communication could achieve better maternal and infant outcomes, but pregnant women with CSP are highly likely to continue pregnancy and develop into PAS. Effective hemostasis means and multidisciplinary team cooperation are needed in perinatal period for ensuring maternal and fetal safety.

[Factors related to thyroid carcinoma in Zhejiang province: a matched case-control study].

Objective: To explore the influencing factors related to thyroid carcinoma. Methods: Matched by sex, age and original residential areas, 659 pairs of cases and controls were recruited and studied. Methods including both single factor analysis and multivariate conditional logistic regression analysis were carried out to identify the influencing factors. Results: Multivariate conditional logistic regression analysis showed that higher education, being diabetic, alcohol intake, tea drinking, occupational physical activity and the frequency of eating fishes/eggs etc., were potentially protective to thyroid carcinoma. Depression, personal history of CT examination and less salt intake seemed to be risk factors on thyroid carcinoma. For males, factors as alcohol intake, tea drinking, occupational physical activity and frequent egg-eating appeared protective. For females, higher education, diabetes, tea drinking, occupational physical activity, frequent consumption of fishes/eggs, short duration of menstruation appeared as possibly protective. Conclusion: Higher education, diabetes, alcohol intake, tea drinking, occupational physical activity, frequent consumption of fishes/eggs, depression, personal history of CT examination and less salt intake served as potential influencing factors to thyroid carcinoma.

Semivolatile Organic Contaminants in the Hawaiian Atmosphere.

An air sampling campaign on the Island of Hawaii aimed to assess background concentrations of semivolatile organic compounds (SVOCs) over the Central Northern Pacific and to explore their distribution along an altitudinal transect. XAD-resin-based passive air samplers were deployed from May to September 2011 at six sites along a transect from the northeastern coast to the Mauna Loa Observatory and at three other island sites. By crossing the trade wind inversion, the transect comprised the marine boundary layer and free troposphere. At the two ends of the transect, flow-through samplers simultaneously sampled air at monthly resolution. Elevated levels of dieldrin, chlordane- and DDT-related pesticides, polycyclic aromatic hydrocarbons (PAHs), and polybrominated diphenyl ethers (PBDEs) at two urban sites indicated contributions from local sources. The composition of chlordane and DDT-related residues indicated recent emissions. PAHs concentrations that decline more rapidly with increasing elevation than those for PBDEs are consistent with faster atmospheric degradation of PAHs. SVOC levels on Mauna Loa were generally at the lower end of concentration ranges reported for remote sites, including the Arctic. However, in contrast to the Arctic, long-range atmospheric transport is deemed less important than human-induced material flow as the source of SVOCs to the island's atmosphere.

Effects of preparation on nutrient and environmental contaminant levels in Arctic beluga whale (Delphinapterus leucas) traditional foods.

For Canadian Arctic indigenous populations, marine mammal (MM) traditional foods (TFs) represent sources of both important nutrients and hazardous environmental contaminants. Food preparation is known to impact the nutrient and environmental contaminant content of processed items, yet the impacts of preparation on indigenous Arctic MM TFs remain poorly characterized. In order to determine how the various processes involved in preparing beluga blubber TFs affect their levels of nutrients and environmental contaminants, we collected blubber samples from 2 male beluga whales, aged 24 and 37 years, captured during the 2014 summer hunting season in Tuktoyaktuk, Northwest Territories, and processed them according to local TF preparation methods. We measured the levels of select nutrients [selenium (Se), polyunsaturated fatty acids (PUFAs)] and contaminants [organochlorine pesticides, perfluoroalkyl and polyfluoroalkyl substances (PFASs), polybrominated diphenyl ethers, polychlorinated biphenyls, polycyclic aromatic hydrocarbons (PAHs), mercury (Hg)] in raw and prepared (boiled, roasted, aged) beluga blubber TFs. The impacts of beluga blubber TF preparation methods on nutrient and environmental contaminant levels were inconsistent, as the majority of processes either did not appear to influence concentrations or affected the two belugas differently. However, roasting and ageing beluga blubber consistently impacted certain compounds: roasting blubber increased concentrations of hydrophilic substances (Se and certain PFASs) through solvent depletion and deposited PAHs from cookfire smoke. The solid-liquid phase separation involved in ageing blubber depleted hydrophilic elements (Se, Hg) and some ionogenic PFASs from the lipid-rich liquid oil phase, while PUFA levels appeared to increase, and hydrophobic persistent organic pollutants were retained. Ageing blubber adjacent to in-use smokehouses also resulted in considerable PAH deposition to processed samples. Our findings demonstrated that contaminant concentration differences were greater between the two sets of whale samples, based on age differences, than they were within each set of whale samples, due to variable preparation methods. When considering means to minimize human contaminant exposure while maximizing nutrient intake, consumption of aged liquid from younger male whales would be preferred, based on possible PUFA enhancement and selective depletion of hydrophilic environmental contaminants in this food item.

[Time characteristics of imported malaria cases in Yunnan Province].

Objective To investigate the time distribution characteristics and the epidemic trends of imported malaria cases in Yunnan Province. Methods The malaria case records and epidemiological history data of Yunnan Province were collected, and the local infection cases were excluded. The data were statistical analyzed. Results The imported malaria cases had a significantly seasonal periodicity (Q = 26.574, P < 0.05) and epidemic trends (Q = 35.487, P < 0.05). The imported peak was in May, while February was the lowest month of imported cases, and the difference was significant (Z = -2.619, P < 0.05). The simple seasonal prediction model was the best model (R2 = 0.677, BIC = 4.867) for forecast while the residual sequence was white noise (Q = 14.226, P > 0.05). By using the model to predict the cases in January, February and March of 2016, the number (95% CI) were 29 (7-50), 22 (0-44) and 31 (8-54), and the actual number of imported malaria cases were 29, 24 and 38 cases respectively and all cases were included in the 95% CI. Conclusion The imported malaria cases in Yunnan Province had a significantly seasonal periodicity and epidemic trends, and the established model has good prediction on the recent cases.

[Regulation effect of ß-catenin pathway on TGF-ß1 induced pulmonary pro-fibrosis].

OBJECTIVE: To investigate the regulation effect of ß-catenin pathway on transforming growth factor beta1 (TGF-ß1) induced pulmonary pro-fibrosis. METHODS: The rat alveolar typeⅡ cells (RLE-6TN) were divided into four groups: A1.control group; B1.TGF-ß1 group was treated with 5 µg/L TGF-ß1; C1.pcDNA+ TGF-ß1 group was transiently transfected with eukaryotic expression vector pcDNA3.0 (pcDNA) and followed by TGF-ß1 treatment (5 µg/L); D1.F-(ß-TrCP)-Ecad+ TGF-ß1 group was transiently transfected with ß-catenin protein knockout vector [F-(ß-TrCP)-Ecad] and followed by TGF-ß1 treatment (5 µg/L). After 24 hours, cells were observed under the inverted phase contrast microscope, then the expressions of E-cadherin, α-smooth muscle actin (α-SMA) and fibronectin (Fn) in each group were measured by Western blot and the mRNA levels of Snail which was the downstream profibrotic transcription production in cell culture supernatants of each group were detected by real-time fluorescence quantification-polymerase chain reaction (RT-PCR) .The rat alveolar macrophages (CRL-2192) were divided into five groups: A2.control group; B2.Interferon gamma (IFN-γ) group was treated by 20 µg/L IFN-γ; C2.TGF-ß1+ IFN-γ group was treated by 20 µg/L IFN-γ with 10 µg/L TGF-ß1; D2.F-(ß-TrCP)-Ecad+ TGF-ß1+ IFN-γ group was transfected with F-(ß-TrCP)-Ecad and other dispose was the same as group C2; E2.WTß-catenin+ TGF-ß1+ IFN-γ group was transfected with WTß-catenin and other dispose was the same as group C2.After 24 hours, protein levels of ß-catenin in group A2, B2, C2 were determined by Western blot.Inducible nitric oxide synthase (iNOS) mRNA levels of each group were detected by RT-PCR. RESULTS: The RLE-6TN cells of group B1, C1 showed a change in morphology to spindle-shaped cells, the cells of group D1 maintained a cobblestone morphology. Protein expressions of the fibroblast markers α-SMA and Fn, and mRNA expressions of the downstream profibrotic transcription production Snail of group B1, C1 were significantly higher than group A1, while protein expressions of the epithelial marker E-cadherin were significantly lower.The protein expressions of α-SMA, Fn and mRNA expressions Snail of group D1 were significantly lower than group C1 (0.352±0.076 vs 0.937±0.303, 0.319±0.072 vs 0.903±0.211, 3.675±0.642 vs 9.708±2.031), while the protein expressions of E-cadherin were significantly higher (1.482±0.227 vs 0.604±0.121) (all P<0.05). The steady state protein levels of ß-catenin in CRL-2192 cells was low and ß-catenin protein expressions of CRL-2192 cells in group A2, B2 and C2 had no significantly statistical differences.The mRNA expressions of iNOS of group B2 cells were significantly higher than group A2, C2, D2, E2 (64.95±4.47 vs 9.87±0.73, 21.32±2.41, 18.35±3.61, 22.87±3.14) (all P<0.01), the expressions of iNOS of group C2, D2, E2 were all higher than group A2 (all P<0.05), but there were no significant differences among group C2, D2 and E2. CONCLUSIONS: Inhibition of ß-catenin pathway inhibits TGF-ß1-induced epithelial-mesenchymal transition (EMT) and has no effect on its anti-inflammation effect.Therefore, ß-catenin pathway regulates the pulmonary pro-fibrosis effect of TGF-ß1.

Exploring the role of the sampler housing in limiting uptake of semivolatile organic compounds in passive air samplers.

Passive air samplers (PASs) are simple, versatile devices that are increasingly used to determine the concentrations of semivolatile organic compounds (SVOCs) in the atmosphere. Using PAS and interpreting PAS-derived data with confidence requires a detailed understanding of the factors that control the uptake kinetics. A number of experiments were aimed at clarifying the role that the housing has in limiting the uptake of SVOCs in a PAS. Specifically, we quantified the gradient in the amount of polychlorinated biphenyls (PCBs) accumulated in XAD-filled mesh cylinders with increasing distance from the PAS housing's opening. That gradient was non-existent in an artificially ventilated housing (i.e. different segments of a cylinder contained the same amount of PCBs), minor during outdoor deployments (i.e. the bottom third of the cylinder sampled approximately 20% more PCBs than the top third), and strong during indoor deployments (i.e. the bottom third of the cylinder sampled twice the amount sampled by the top third). This is consistent with the thickness of the air boundary layer surrounding the XAD-resin increasing with increasing distance from the housing's opening and decreasing with increasing air turbulence. An experiment with housings absorbing different amounts of sunlight revealed that heat-induced convection has a minor effect on the gradient within the mesh cylinder and on the total amount of accumulated PCB. Similarly, this gradient and the total amount sorbed was also not influenced by the number of XAD-filled mesh cylinders placed within a housing as long as they were deployed outdoors. However, if four mesh cylinders were placed in one housing in a calm indoor setting, the top third of the mesh cylinders was notably starved of PCBs, suggestive of an air concentration gradient within the sampler housing.

Strong coronal channelling and interplanetary evolution of a solar storm up to Earth and Mars.

The severe geomagnetic effects of solar storms or coronal mass ejections (CMEs) are to a large degree determined by their propagation direction with respect to Earth. There is a lack of understanding of the processes that determine their non-radial propagation. Here we present a synthesis of data from seven different space missions of a fast CME, which originated in an active region near the disk centre and, hence, a significant geomagnetic impact was forecasted. However, the CME is demonstrated to be channelled during eruption into a direction +37±10° (longitude) away from its source region, leading only to minimal geomagnetic effects. In situ observations near Earth and Mars confirm the channelled CME motion, and are consistent with an ellipse shape of the CME-driven shock provided by the new Ellipse Evolution model, presented here. The results enhance our understanding of CME propagation and shape, which can help to improve space weather forecasts.

Compound heterozygous mutations in TTC7A cause familial multiple intestinal atresias and severe combined immunodeficiency.

Familial multiple intestinal atresias is an autosomal recessive disease with or without combined immunodeficiency. In the last year, several reports have described mutations in the gene TTC7A as causal to the disease in different populations. However, exact correlation between different genotypes and various phenotypes are not clear. In this study, we report identification of novel compound heterozygous mutations in TTC7A gene in a Malay girl with familial multiple intestinal atresias and severe combined immunodeficiency (MIA-SCID) by whole exome sequencing. We found two mutations in TTC7A: one that destroyed a putative splicing acceptor at the junction of intron 17/exon 18 and one that introduced a stop codon that would truncate the last two amino acids of the encoded protein. Reviewing the recent reports on TTC7A mutations reveals correlation between the position and nature of the mutations with patient survival and clinical manifestations. Examination of public databases also suggests carrier status for healthy individuals, making a case for population screening on this gene, especially in populations with suspected frequent founder mutations.

Observations of an extreme storm in interplanetary space caused by successive coronal mass ejections.

Space weather refers to dynamic conditions on the Sun and in the space environment of the Earth, which are often driven by solar eruptions and their subsequent interplanetary disturbances. It has been unclear how an extreme space weather storm forms and how severe it can be. Here we report and investigate an extreme event with multi-point remote-sensing and in situ observations. The formation of the extreme storm showed striking novel features. We suggest that the in-transit interaction between two closely launched coronal mass ejections resulted in the extreme enhancement of the ejecta magnetic field observed near 1 AU at STEREO A. The fast transit to STEREO A (in only 18.6 h), or the unusually weak deceleration of the event, was caused by the preconditioning of the upstream solar wind by an earlier solar eruption. These results provide a new view crucial to solar physics and space weather as to how an extreme space weather event can arise from a combination of solar eruptions.

Effect of wind on the chemical uptake kinetics of a passive air sampler.

Passive air samplers (PASs) operate in different types of environment under various wind conditions, which may affect sampling rates and thus introduce uncertainty to PAS-derived air concentrations. To quantify the effect of wind speed and angle on the uptake in cylindrical PASs using XAD-resin as the sampling medium, we measured the uptake kinetics of polychlorinated biphenyls (PCBs) in XAD and of water in silica-gel, both under quasi wind-still condition and with lab-generated wind blowing toward the PASs at various speeds and angles. Passive sampling rates (PSRs) of PCBs under laboratory generated windy conditions were approximately 3-4 times higher than under wind-still indoor conditions. The rate of water uptake by silica-gel increased with wind speed, following a logarithmic function so that PSRs are more strongly influenced at lower wind speed. PSRs of both PCBs and water varied little with wind angle, which is consistent with computational fluid dynamic simulations showing that different angles of wind incidence cause only minor variations of air velocities within the cylindrical sampler housing. Because modifications of the design of the cylindrical PAS were not successful in eliminating the wind speed dependence of PSRs at low wind levels, indoor and outdoor deployments require different sets of PSRs. The effect of wind speed and angle on the PSRs of the cylindrical PAS are much smaller than what has been reported for the double-bowl polyurethane foam PAS. PSRs of the cylindrical XAD-PAS therefore tend to vary much less between sampling sites exposed to different wind conditions.

Calibration and application of a passive air sampler (XAD-PAS) for volatile methyl siloxanes.

Because the atmosphere is key to understanding the environmental behavior of volatile methyl siloxanes (VMS), a variety of reliable air sampling methods are needed. The purpose of this study was to calibrate and evaluate an existing, polystyrene-divinylbenzene copolymeric resin-based passive air sampler (XAD-PAS) for VMS. Sixteen XAD-PAS were deployed for 7-98 days at a suburban site in Toronto, Canada, while the VMS concentration in air was monitored by an active sampling method. This calibration and a subsequent field test further allowed for investigation of the temporal and spatial variability of VMS in the region. Uptake in the XAD-PAS of octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and three linear VMS was linear throughout the whole deployment period. Sampling rates were between 0.4 and 0.5 m(3)/day. The XAD-PAS measured ∑VMS concentrations ranged from nondetects in rural areas (n = 3), to 169 ± 49 ng/m(3) in the urban region (n = 21), to levels above 600 ng/m(3) at sewage treatment plants (n = 2). Levels and composition of VMS within the urban area were remarkably uniform in space. Levels, but not composition, were highly variable in time and weakly correlated with temperature, wind speed, and wind direction.

Impact of nursing home residence on hospital epidemiology of meticillin-resistant Staphylococcus aureus: a perspective from Asia.

In a Singapore hospital practising meticillin-resistant Staphylococcus aureus (MRSA) admission screening, the relative risk for MRSA colonization for those admitted from nursing homes was 6.89 (95% confidence interval: 5.74-8.26; 41% of 190 vs 6.0% of 14,849). However, the MRSA burden on admission attributable to nursing home residence was low (6.9%). Risk factors independently associated with MRSA colonization in patients admitted from nursing homes were previous hospital admissions, broken skin, prior use of antibiotics and Chinese ethnicity. Low rates of nursing home use means that the overall impact of nursing home residence on MRSA in our hospital is low.

Protein transduction domain-hA20 fusion protein protects endothelial cells against high glucose-induced injury.

We constructed a plasmid containing a protein transduction domain (PTD) and a human A20 (hA20) gene fragment; the fusion protein was obtained by highly expressing this plasmid in the yeast Pichia pastoris GS115. The plasmid was obtained by adding 9xArg and EcoRІ recognition sites to the end of the primer, and 6xHis-Tag and NotІ recognition sites to its end. After sequencing, the hA20 gene fragment was inserted into plasmid pPIC9k to construct expression vector pPIC9k-PTD-hA20; then, we transfected GS115 with the vector and induced PTD-hA20 protein expression. We purified protein from the yeast fermentation supernatant using a nickel column. Human umbilical vein endothelial cells (HUVECs) were cultured in high glucose medium (30 mM glucose) and in high glucose medium containing different concentrations of protein. Apoptosis of HUVECs was assayed by TUNEL 72 h later. The biological activity tests indicated that the fusion protein not only passed through the cell membrane freely, but also inhibited apoptosis of HUVECs induced by high glucose levels. We conclude that the fusion protein PTD-hA20 has potential for clinical use.

Influence of sampler configuration on the uptake kinetics of a passive air sampler.

Passive air samplers (PAS) are simple and cost-effective tools to monitor semivolatile organic compounds in air. Chemical uptake occurs by molecular diffusion from ambient air to a passive sampling medium (PSM). Previous calibration studies indicate that even for the same type of PAS, passive air sampling rates (R, m(3)(air)/d) can be highly variable due to the influence of a number of factors. Earlier studies mainly focused on factors (e.g., wind speed and temperature) influencing R via the kinetic resistance posed by the air boundary layer surrounding the PSM because that layer was deemed to be the main factor determining the uptake kinetics. Whereas recent calibration studies suggest that the PAS configuration can influence R, so far few studies have specifically focused on this factor. In this study, with the objective to understand the effect of PAS configurations on R, we applied a gravimetrical approach to study the kinetics of water vapor uptake from indoor air by silica gel placed inside cylindrical PAS of various configurations. We also conducted an indoor calibration for polychlorinated biphenyls on the same type of PAS using XAD-resin as the PSM. R was found to be proportional to the interfacial transfer area of the PSM but not the amount of the PSM because chemicals mainly accumulated in the outer layer of the PSM during the deployment time of the PAS. The sampler housing and the PSM can introduce kinetic resistance to chemical uptake as indicated by changes in R caused by positioning the PSM at different distances from the opening of the sampler housing and by using PSM of different diameters. Information gained from this study is useful for optimizing the PAS design with the objective to reduce the material and shipping costs without sacrificing sampling efficiency.

Sampling medium side resistance to uptake of semivolatile organic compounds in passive air samplers.

Current theory of the uptake of semivolatile organic compounds in passive air samplers (PAS) assumes uniform chemical distribution and no kinetic resistance within the passive sampling media (PSM) such as polystyrene-divinylbenzene resin (XAD) and polyurethane foam (PUF). However, these assumptions have not been tested experimentally and are challenged by some recently reported observations. To test the assumptions, we performed kinetic uptake experiments indoors using cylindrical PSM that had been concentrically segmented into three layers. Both XAD and PUF were positioned in the same type of sampler housing to eliminate the variation caused by the different housing designs, which enabled us to quantify differences in uptake caused by the properties of the PSM. Duplicated XAD (PUF) samples were retrieved after being deployed for 0, 1 (0.5), 2 (1), 4 (2), 8 (4), 12 (8), and 24 (12) weeks. Upon retrieval, the PSM layers were separated and analyzed individually for PCBs. Passive sampling rates (R) were lower for heavier PCB homologues. Within a homologue group, R for XAD was higher than that for PUF, from which we infer that the design of the "cylindrical can" housing typically used for XAD PAS lowers the R compared to the "double bowl" shelter commonly used for PUF-disk PAS. Outer layers of the PSM sequestered much higher levels of PCBs than inner layers, indicative of a kinetic resistance to chemical transfer within the PSM. The effective diffusivities for chemical transfer within PSM were derived and were found negatively correlated with the partition coefficients between the PSM and air. Based on the results, we conclude that the PSM-side kinetic resistance should be considered when investigating factors influencing R and when deriving R based on the loss of depuration compounds.

Current-use pesticide transport to Costa Rica's high-altitude tropical cloud forest.

To gain insight into the atmospheric transport and deposition of organic contaminants in high-altitude forests in the humid tropics, pesticides were analyzed in air, water, and soil samples from Costa Rica. Passive samplers deployed across the country revealed annually averaged air concentrations of chlorothalonil, endosulfan, and pendimethalin that were higher in areas with intensive agricultural activities than in more remote areas. Atmospheric concentrations were particularly high in the intensively cultivated central valley. Only endosulfan and its degradation products were found in soils sampled along an altitudinal transect on the northern side of Volcano Turrialba, which is facing heavily cultivated coastal plains. Consistent with calculations of cold trapping in tropical mountains, concentrations of endosulfan sulfate increased with altitude. Pesticide levels in lake, creek, fog, and arboreal water samples from high-elevation cloud forests were generally below 10 ng · L(-1). Endosulfan sulfate was the most abundant pesticide in water, with concentrations ranging from 0.4 to 9.4 ng · L(-1). Its levels were highest in water sampled from bromeliads. Levels of total endosulfan in water are much lower than the reported median lethal concentration (LC50) value for acute toxicity of α-endosulfan to tadpoles. Although this suggests that the presence of pesticide might not have a direct impact on amphibian populations, the possibility of effects of chronic exposure to a mixture of substances cannot be excluded. Fog was relatively enriched in some of the analyzed pesticides, such as dacthal and chlorothalonil, and may constitute an important deposition pathway to high-altitude tropical cloud forest.