[Low-dose CT reconstruction based on high-dimensional partial differential equation projection recovery]

OBJECTIVE

We propose a low-dose CT reconstruction method using partial differential equation (PDE) denoising under high-dimensional constraints.

METHODS

The projection data were mapped into a high-dimensional space to construct a high-dimensional representation of the data, which were updated by moving the points in the high-dimensional space. The data were denoised using partial differential equations and the CT image was reconstructed using the FBP algorithm.

RESULTS

Compared with those by FBP, PWLS-QM and TGV-WLS methods, the relative root mean square error of the Shepp-Logan image reconstructed by the proposed method were reduced by 68.87%, 50.15% and 27.36%, the structural similarity values were increased by 23.50%, 8.83% and 1.62%, and the feature similarity values were increased by 17.30%, 2.71% and 2.82%, respectively. For clinical image reconstruction, the proposed method, as compared with FBP, PWLS-QM and TGV-WLS methods, resulted in reduction of the relative root mean square error by 42.09%, 31.04% and 21.93%, increased the structural similarity values by 18.33%, 13.45% and 4.63%, and increased the feature similarity values by 3.13%, 1.46% and 1.10%, respectively.

CONCLUSION

The new method can effectively reduce the streak artifacts and noises while maintaining the spatial resolution in reconstructed low-dose CT images.

Microplastic pollution in urban stormwater inlet sediments influenced by land use type of runoff drainage area

Since the urban stormwater inlet (USI) acts as a link in the migration of microplastics (MPs) in stormwater, sufficient information on MPs in USI sediments is very important for understanding urban diffuse microplastic pollution. In this study, the abundance and characteristics of MPs in the USI sediments of Ma'anshan City, China, were analyzed based on urban land use type. MPs were prevalent in the USI sediments, with the average abundances of 536.77 ± 313.92 items·kg-1 for commercial areas, 505.64 ± 400.82 items·kg-1 for campuses, 694.71 ± 219.95 items·kg-1 for industrial areas, 526.41 ± 152.34 items·kg-1 for residential areas, and 1107.75 ± 422.10 items·kg-1 for main roads, indicating a high microplastic pollution in the USI sediments from main roads. The microplastic polymers were mainly polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), and polystyrene (PS), accounting for 46.75 %-100.00 %, with PP MPs being the most abundant. Fiber MPs had the highest proportion in USI sediments from both campuses (35.30 %) and industrial areas (38.19 %), while film MPs were the most abundant for both commercial areas (39.91 %) and residential areas (35.65 %). The average proportions of fiber (27.29 %), fragment (29.18 %), and film (28.68 %) were almost equal for main roads, unlike other land use types. Except for campuses, transparent MPs were the most common for all land use types, with average proportions of 29.60 %-42.70 %. The proportions of MPs with sizes of <1000 μm were 72.54 % for commercial areas, 77.11 % for campuses, 76.05 % for industrial areas, 70.76 % for residential areas, and 74.29 % for main roads, respectively, with a consistent result with previous study that the MPs of <1000 μm are the predominant in the environment. This study enriches the knowledge of microplastic pollution in USI sediments and will benefit the mitigation of diffuse microplastic pollution.

Impacts of the steel industry on sediment pollution by heavy metals in urban water system

The impact of the steel industry on sediment heavy metal (HM) pollution in urban aquatic environments was investigated in a major iron ore-producing area (Ma'anshan) in China. The concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were 9.68 ± 3.56, 170.31 ± 82.40, 90.62 ± 19.54, 30.61 ± 6.72, 125.43 ± 63.60, and 1276.59 ± 701.90 mg/kg in the steel industry intruded upon sediments and 4.63 ± 1.41, 87.60 ± 10.96, 52.67 ± 19.99, 37.49 ± 6.17, 35.84 ± 11.41, and 189.02 ± 95.57 mg/kg in the control area, respectively. Comparing with the local soil background (0.08 mg/kg for Cd, 62.6 mg/kg for Cr, 19.3 mg/kg for Cu, 28.1 mg/kg for Ni, 26.0 mg/kg for Pb, and 58.0 mg/kg for Zn), significantly higher levels of Cd, Cr, Cu, Pb, and Zn were detected in the steel industry affected sediments. The enrichment factor and principal component analysis indicated that the heavy metals (HMs), except for Ni, were primarily derived from anthropogenic inputs, particularly from steel industrial activities. Multiple risk assessment models suggested that the sediments affected by industrial activities showed significant toxic effects for Cd, Cr, Pb, and Zn, with Cd being the main contributor to sediment toxicity. However, the alkaline nature of the sediments (pH = 7.85 ± 0.57) and the high proportion of residual fraction Cd (61.09% ± 26.64%) may help to reduce the toxic risks in the sediments. Effective measures to eliminate tinuous thethe continous input of Cd and Zn via surface runoff are crucial.

Microplastics and microorganisms in sediments from stormwater drain system

Research has already confirmed the occurrence of microplastics (MPs) in sediments of stormwater drain system (SDS). However, the microplastic pollution remains to be elucidated well in sediments, especially the spatio-temporal distribution and the impacts of MPs on microorganisms. In this study, the averaged abundance of MPs in SDS sediments was 479 ± 688 items·kg^-1 for spring, 257 ± 93 items·kg^-1 for summer, 306 ± 227 items·kg^-1 for autumn and 652 ± 413 items·kg^-1 for winter. As expected, the abundance of MPs was the lowest in summer due to runoff scouring, while the highest in winter attributed to infrequent low-intensity rainfall. The major polymers of MPs were polyethylene terephthalate and polypropylene plastics, occupying 76 % to 98 % of the total number. Fiber MPs were the most regardless of season (41 % to 58 %). MPs with size of 250-1000 μm accounted for over 50 %, which is in accordance with the previous study that MPs of <1000 μm were the major. High-throughput sequencing of analysis shows that MPs provided an ecological niche for bacterial communities different from that of SDS sediments. Actinomycetes and bacteria with chemoheterotrophic genes tended to be enriched on the surfaces of MPs. In addition, Acidobacteria and bacteria with nitrification genes would not like to present in microplastisphere. A strong positive correlation (R from 0.74 to 0.83, P < 0.01) was found between the abundance of MPs in sediments and the abundance of functional genes for denitrification and nitrogen respiration of microorganisms on the surfaces of MPs. It indicates that MPs may influence the nitrogen transformation processes in SDS sediments via the occurrence of denitrification processes on the surfaces of MPs. The abundance of MPs had no significant relationship with the various functional genes of microorganisms in the sediments (P > 0.05), which means that MPs could not profoundly influence the expression of microbial functional genes in SDS sediments.

Microplastics as vectors of organic pollutants in aquatic environment: A review on mechanisms, numerical models, and influencing factors

Microplastics (MPs), a new class of emerging pollutants, have attracted exponentially increased attention due to the adverse ecological impacts on biota, not only by themselves but also by the combined corrosive substances. However, the occurrence mechanisms, numerical models and influencing factors of MPs adsorbing organic pollutants (OPs) show a significant variation with literatures. Therefore, this review is focused on the adsorption of OPs on MPs, including mechanisms, numerical models, and influencing factors, to obtain a comprehensive understanding. Research shows that MPs with strong hydrophobicity have high adsorption capacity for hydrophobic OPs. Hydrophobic distribution and surface adsorption are considered to be the main mechanisms by which MPs adsorb OPs. The available literature suggests that the pseudo-second-order model describes the adsorption kinetics of OPs on MPs better than the pseudo-first-order model, while the choice of Freundlich or Langmuir isotherm model depends mainly on the specific environmental conditions. Moreover, the characteristics of MPs (composition, particle size, aging, etc.), the nature of OPs (concentration, polarity, hydrophilicity, etc.), the environmental conditions (temperature, salinity, pH, ionic strength, etc.), and the substances co-existing in the environment (e.g., DOM and surfactants) are all important factors affecting the adsorption behavior of MPs for OPs. Environmental conditions can also indirectly affect the adsorption of hydrophilic OPs adsorbed on MPs by causing changes in the surface properties of MPs. Based on the current knowledge, the perspective shortening the knowledge gap is also suggested.

Microplastic pollution in sediments of urban rainwater drainage system

The sink of microplastics (MPs) in sediments of urban rainwater drainage system (RDS) is of great concern, because the MPs deposited can be resuspended by flow disturbance. Previous research has confirmed the significant accumulation of MPs in sediments of urban RDS, but it remains poorly elucidated, such as pollution sources and influencing factors. In this study, we investigated the MPs in sediments from RDS of a university campus. MPs were detected from all sediment samples, showing the ubiquity of microplastic pollution. Among 11 samples MPs' abundance ranged from 80 to 2610 particles/kg (dry weight), with highly spatial variability, depending on land type and environmental management practice within the catchment. Sites from office & teaching area had the averaged abundance of 335.00 ± 196.85 particles/kg, while 270.00 ± 89.09 particles/kg for staff residential area, and 795.00 ± 1050.65 particles/kg for student living area, indicating that the sediments of RDS from student living area had the highest abundance of MPs. However, independent sample t-test analysis suggests there is no statistically significant difference between land types, because of effective environmental management practices in the catchment. The surfaces of MPs were much rough, which implies that the fragmentation of larger plastic particles resulted in the production of MPs. Although the MPs of <1000 μm were the most, 1000-2000 μm MPs also accounted for a significant proportion in this study, showing a slight difference from the previous study in which MPs over 1 mm were quite low. Polypropylene (PP) and polyester (PET) found to be dominant with 49.75 ± 18.69 % and 49.75 ± 18.69 % of the total number, respectively. As to shapes, the proportion of fiber and fragment MPs exceeded 80 %. The color of MPs diversified greatly, and the MPs with bright colors occupied over 80 %. Fabric fibers, food packaging and courier packaging materials were figured out to be the considerable contributors of MPs.

Effect of Avian Influenza Virus subtype H9N2 on the expression of complement-associated genes in chicken erythrocytes

The H9N2 subtype avian influenza virus can infect both chickens and humans. Previous studies have reported a role for erythrocytes in immunity. However, the role of H9N2 against chicken erythrocytes and the presence of complement-related genes in erythrocytes has not been studied. This research investigated the effect of H9N2 on complement-associated gene expression in chicken erythrocytes. The expression of complement-associated genes (C1s, C1q, C2, C3, C3ar1, C4, C4a, C5, C5ar1, C7, CD93 and CFD) was detected by reverse transcription-polymerase chain reaction (RT-PCR). Quantitative Real-Time PCR (qRT-PCR) was used to analyse the differential expression of complement-associated genes in chicken erythrocytes at 0 h, 2 h, 6 h and 10 h after the interaction between H9N2 virus and chicken erythrocytes in vitro and 3, 7 and 14 d after H9N2 virus nasal infection of chicks. Expression levels of C1q, C4, C1s, C2, C3, C5, C7 and CD93 were significantly up-regulated at 2 h and significantly down-regulated at 10 h. Gene expression levels of C1q, C3ar1, C4a, CFD and C5ar1 were seen to be different at each time point. The expression levels of C1q, C4, C1s, C2, C3, C5, C7, CFD, C3ar1, C4a and C5ar1 were significantly up-regulated at 7 d and the gene expression of levels of C3, CD93 and C5ar1 were seen to be different at each time point. The results confirmed that all the complement-associated genes were expressed in chicken erythrocytes and showed the H9N2 virus interaction with chicken erythrocytes and subsequent regulation of chicken erythrocyte complement-associated genes expression. This study reported, for the first time, the relationship between H9N2 and complement system of chicken erythrocytes, which will provide a foundation for further research into the prevention and control of H9N2 infection.

Aging dependent plastic bag derived-microplastics as a vector of metals in lake water

The adsorption of microplastics (MPs) for metals in aquatic environment remains poorly understood due to the use of either commercial MPs, which have different property from the MPs in environments, or artificial solutions, which have not only the significantly higher concentration of metals than natural aqueous environment but also the different natures. In this study, we elaborated the adsorption throughout the aging process of plastic bag derived-MPs (initially 1-2 mm) by potassium persulfate (K₂S₂O₈) solution to metals in lake water. Comparatively, plastic bag derived-MPs had the highest adsorption capacity for Zn²⁺ followed by Fe³⁺, Pb²⁺, Mn²⁺, Cr⁶⁺, Ni²⁺, Cu²⁺ and Cd²⁺, which is not completely consistent with the literature. Both the adsorption capacity and distribution coefficients of Cu²⁺, Ni²⁺, Zn²⁺, Mn²⁺ and Pb²⁺ had significant linear correlation with carbonyl index (p < 0.05). Although the aging overall enhanced the adsorption, the adsorption capacities of MPs might fluctuate depending on metal.

Invasive fungal infection is associated with antibiotic exposure in preterm infants: a multi-centre prospective case-control study

BACKGROUND

Previous antibiotic exposure is an important risk factor for invasive fungal infection (IFI). Antibiotic overexposure is common in lower-income countries; however, multi-centre studies concerning IFI in relation to antibiotic exposure are scarce.

AIM

This prospective, multi-centre matched case-control study explored the correlation of IFI and antibiotic exposure in very preterm infants or very-low-birthweight infants admitted to 23 tertiary hospitals in China between 2018 and 2021.

METHODS

Using a 1:2 matched design for gestational age, birth weight and early-onset sepsis (yes/no), the risk factors between infants diagnosed with IFI and infection-free controls were compared. The antibiotic use rate (AUR) was calculated using calendar days of antibiotic therapy in the 4 weeks preceding IFI onset divided by onset day of IFI.

FINDINGS

In total, 6368 infants were included in the study, of which 90 (1.4%) were diagnosed with IFI. Median AUR, length of antibiotic therapy (LOT) and days of antibiotic therapy (DOT) within the 4 weeks preceding IFI onset were 0.90, 18 days and 30 days, respectively. Multi-variate analysis showed that a 10% increase in AUR, each additional day of DOT and LOT, and each additional day of third-generation cephalosporins and carbapenems were notably associated with IFI.

CONCLUSION

Prolonged antibiotic therapy is common before the onset of IFI, and is an important risk factor, especially the use of third-generation cephalosporins and carbapenems. Antibiotic stewardship should be urgently developed and promoted for preterm infants in order to reduce IFI in lower-income countries such as China.

Heavy Metals Present in the Soils from Extremely Large Opencast Iron Mine Pit

The mining areas have faced severe pollution by caustic metals. In this study, heavy metals (Cu, Zn, Cr, Cd, Pb and Ni) in the soil of an extremely large iron mine pit from Ningwu-Luohe metallogenic belt, one of the seven iron ore areas in China was characterized. SiO₂ was predominant soil mineral composition as 57.0 ± 1.3 %, followed by considerable Al₂O₃ (23.1 ± 2.5 %) and Fe₂O₃ (8.58 ± 1.2 %). Cu, Zn, Cr, Cd, Pb and Ni had the range of 7.62-237, 97.8-313, 1.73-43.8, 0.119-0.512, 5.13-44.7 and 7.87-23.9 mg/kg, respectively, wherein, Cu, Zn, Cr and Pb were likely to have relatively low concentration in the soil from the boom of mining pit. Comparatively, both Cu and Zn arose at the level of 1-fold higher than that of local background values, indicating that the soil from mining pit had been subjected to Cu and Zn accumulation. BCR (European Communities Bureau of Reference) sequential extraction analysis showed that these metals mainly existed in residual fraction, with averaged percentages of 42.0 ± 18 %, 70.3 ± 8.1 %, 76.6 ± 18 %, 30.2 ± 14 %, 52.5 ± 11 % and 61.0 ± 9.7 % for Cu, Zn, Cr, Cd, Pb and Ni, respectively. Geo-accumulation index indicates that the soil was moderately contaminated by Cu, practically uncontaminated or uncontaminated to moderately contaminated by Zn, while practically uncontaminated by Cr, Cd, Pb and Ni. There were just significant relationships between Zn and Cd and between Cd and Pb, indicating that Cd in the soil investigated possibly had at least two sources and for most of the elements the sources were different. The effects of pit depth and major soil composition on the distribution of trace metals varied depending on the element itself and its chemical forms.

[Treatment strategies and research progress of acute ilio-femoral deep vein thrombosis]

In the past,treatment of acute ilio-femoral deep vein thrombosis (IFDVT) was mainly based on anticoagulation alone,but 30%-50% of patients will develop post-thrombotic syndrome,causing a serious medical burden.Thrombus removal technology such as catheter-directed thrombolysis and percutaneous mechanical thrombectomy can effectively remove blood clots and compensate for the deficiencies of simple anticoagulation,which is expected to improve the prognosis of such disease,but the current evidence is insufficient,and other treatments such as filter implantation and compression therapy are also controversial.This article summarizes the treatment strategies and the latest progress of acute IFDVT,hoping to help the treatment of this type of disease.

Glutathione-S-transferase A3 protein suppresses thiram-induced tibial dyschondroplasia by regulating prostaglandin-related genes expression

Tibial dyschondroplasia (TD) is an intractable avian cartilage disease in which proximal growth plates of tibia lack blood vessels and contain nonviable cells, and it leads to the inflammatory response. Prostaglandins (PGs) genes have not been studied yet in TD chicken, and they might play role in skeletal metabolism, therefore we planned to explore the role of recombinant glutathione-S-transferase A3 (rGSTA3) protein and PG-related genes. In this study, qRT-PCR, enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC) analysis were used to identify the expression patterns of eight PG-related genes in the tibial growth plate of broiler chicken. The results showed that the expression of PG-related genes glutathione-S-transferase A3 (GSTA3), cyclooxygenase 2 (COX-2), prostaglandin D2 synthase (PTGDS), prostaglandin E synthase (PTGES), prostaglandin E2 receptor (PTGER) 3, PTGER4, prostaglandin reductase 1 (PTGR1) and hematopoietic prostaglandin D synthases (HPGDS) expression were identified and could significantly respond to thiram-induced TD chicken. Interestingly, the expression of rate-limiting enzyme COX-2 and PGE₂ were induced after the treatment of rGSTA3 protein. These findings demonstrated that the occurrence of TD is closely related to the inhibition of PGs. Moreover, rGSTA3 protein participated in the recovery of TD by strengthening the expression of PG-related genes.

[The expression and significance of IGF1R-Ras/RAGE-HMGB1 pathway in colorectal cancer patients with type 2 diabetes mellitus]

Objective: To investigate the expression of IGF1R-Ras and RAGE-HMGB1 signaling pathways in colorectal cancer patients with type 2 diabetes mellitus and their significance. Methods: The resected cancer tissues were obtained from 59 patients with colorectal cancer (CRC), including 29 patients with type 2 diabetes mellitus (CRC/DM group) and 30 with CRC alone (CRC group). The expressions of IGF1R, Ras, RAGE and HMGB1 in cancer tissues were detected by immunohistochemistry. The differences between the two groups were compared and the relationship between the expression and clinicopathological characteristics was analyzed. Results: In CRC/DM group, the positive rates of IGF1R and Ras were both 65.5% (19/29), and 51.7% (15/29) patients had IGF1R+ Ras+ immunophenotype, which were significantly higher than those in CRC group [33.3% (10/30), 36.7% (11/30) and 20.0% (6/30); P=0.013, 0.027 and 0.011, respectively]. The expression of IGF1R and Ras in CRC / DM group was positively correlated (r=0.479, P=0.017). The positive rate of RAGE expression in CRC group and CRC/DM group was 70.0% (21/30) and 72.4% (21/29) respectively, and the positive rate of HMGB1 expression was 46.7% (14/30) and 58.6% (17/29) respectively, neither was observed with significant difference (P=0.358 and 0.838). However, the proportion of patients with RAGE+ HMGB1+ immunophenotype in CRC/DM group [55.2% (16/29)] was higher than that in CRC Group [26.7% (8/30)] which was statistically significant (P=0.026), and the expression of both proteins was positively correlated in CRC/DM group (r=0.578, P=0.003). The clinicopathological analysis showed that in both groups the expression of IGF1R, Ras, RAGE and HMGB1 had no correlation with the sex, age, differentiation degree, tumor length, T stage and lymph node metastasis (P>0.05). Conclusion: Both IGF1R-Ras and RAGE-HMGB1 pathways may be involved in the oncogenesis of colorectal cancer in patients with type 2 diabetes.

Pollution reduction by recirculated fill-and-drain mesocosm wetlands packed with woodchip/pumice treating impervious road stormwater

Constructed wetlands (CWs) are natural-friendly method to eliminate the pollutants stormwater pollutants. For this study, a pilot-scale treatment system consisting of a sedimentation tank (ST) and five recirculated fill-and-drain wetlands (namely CW-1, CW-2, CW-3, CW-4 and CW-5) were constructed to treat the first-flush from the impervious road. From bottom to top, the main substrates of CWs were selected as 0 cm woodchip + 60 cm pumice for CW-1, 15 cm woodchip + 45 cm pumice for CW-2, 30 cm woodchip + 30 cm pumice CW-3, 45 cm woodchip + 15 cm pumice CW-4 and 60 cm woodchip + 0 cm pumice for CW-5. During the operational period, the reduction efficiencies of TSS, total COD, total nitrogen and total phosphorus were 89-100%, 52-100%, 31-87% and 72-100% by CW-1, 92-100%, -27% to 78%, 8-85%, 49-94% by CW-2, 89-100%, -97% to 77%, -29% to 86%, -46% to 94% by CW-3, 89-100%, -115 to 69%, -21% to 99%, 35-94% by CW-4 and 59-100%, -342%to 88%, -20% to 88%, -77% to 99% by CW-5, respectively. Overall, the reduction efficiency, except for nitrogen, declined as the amount of woodchip increased. As excepted, the employment of woodchip improved denitrification via providing with carbon sources, resulting in low NO₃-N but unfavourable COD concentrations in the effluent. And the combination use of woodchip and pumice as CW-3 or CW-4 is suggested, whereas the specific amount of woodchip and pumice should be determined based on the regional environmental goal.

Microplastics in Sediments of River Yongfeng from Maanshan City, Anhui Province, China

This study was performed to evaluate the microplastics (MPs) pollution of sediments from River Yongfeng. It was observed that the MPs in sediments were present with contents of 0.5-16.75 mg/kg and abundances of 5-72 items/kg, coupled by variation coefficients of 109% and 91%, respectively, indicating that the distribution of MPs had high spatial variation. The land-based source of business zone is thought to be the significant contributor to accumulation of MPs in those sites with high quantity of MPs. Film was the predominant shape of MPs in river sediments followed by the line and fragment ones. Meanwhile, the MPs detected were mainly composed by four types including Polypropylene (24%), Polyethylene (61%), Polyethylene Terephthalate (8%) and Polystyrene (7%) based on number fraction, respectively, which indicates that Polypropylene and Polyethylene were the major types of MPs in the sediments. Size fraction performance suggests that those MPs < 1000 μm were of ubiquitous presence. The weathering of fringes was universally observed regardless of varying surface among MPs. Despite digestion with oxidative acid solution and subsequent washing by distilled water unexpected elements can still be detected, which should be considered as determining the materials associated.

Characteristics of particle size distribution and related contaminants of highway-deposited sediment, Maanshan City, China

Road-deposited sediment (RDS) has been identified as both the source and sink of various pollutants. In this study, the highway-deposited sediment (HDS) in Spring, Summer, Autumn and Winter was characterized. On average, the mass proportions of particles with the size of 830-4750 μm, 500-830 μm, 250-500 μm, 150-250 μm, 63-150 μm and < 63 μm were 23.6 ± 8.6%, 16.9 ± 3.4%, 28.4 ± 3.5%, 10.0 ± 4.3%, 15.7 ± 5.8% and 5.3 ± 2.0%, respectively, wherein the HDS of 63-830 μm accounted for 71% of the total mass load. It was observed that the particle size distribution of HDS could be described using the gamma distribution function based on gravimetric and cumulative basis (R² (determination coefficient) = 0.9960-0.9995). The bulk pollutant contents of HDS showed seasonal variation with the mean of COD (chemical oxygen demand), nitrogen, phosphorus, Zn (zinc), Pb (lead) and Cd (cadmium) as 57 g/kg, 839 mg/kg, 97 mg/kg, 627 mg/kg, 110 mg/kg and 1.00 mg/kg and the highest COD of 83 g/kg in Autumn, nitrogen 1164 mg/kg Autumn, phosphorus 133 mg/kg Winter, Zn 801 mg/kg Summer, Pb 133 mg/kg Spring and the highest Cd of 1.36 mg/kg in Summer, respectively. The contents of Zn, Pb and Cd in HDS were significantly above their local soil background values. Moreover, the size fractional pollutant contents overall increased as particles' size increased. Averagely, 40-52% pollutant loads were associated with the particles < 250 μm, which can be moved easily by runoff. This study suggests that the behaviors of HDS different from city RDS should be considered as nonpoint source pollution control is performed.

The expression of prostaglandins-related genes in erythrocytes of broiler chicken responds to thiram-induced tibial dyschondroplasia and recombinant glutathione-S-transferase A3 protein

Tibial dyschondroplasia (TD) is a type of bone deformity found in fast-growing chickens, which induce inflammatory responses. Prostaglandins (PGs) implicate in bone formation and bone resorption, associated with inflammation in an autocrine/paracrine manner. This study used qRT-PCR and immunohistochemistry analysis to identify the expression patterns of PG-related genes in the erythrocytes of broiler chickens and explore the effects of thiram-induced TD and the recombinant glutathione-S-transferase A3 (rGSTA3) protein on the expression of PG-related genes: GSTA3, cyclooxygenase 2 (COX-2), prostaglandin D2 synthase (PTGDS), prostaglandin E synthase (PTGES), prostaglandin E2 receptor (PTGER) 3, PTGER4 and prostaglandin reductase 1 (PTGR1). Interestingly, the results showed that these seven PG-related genes expression was identified in the erythrocytes of broiler chicken, and thiram-induced TD suppressed the expression of these PG-related genes in the initial stage of TD and promoted their expression in TD recovery. These findings demonstrated that the immunoregulatory function of erythrocytes can be inhibited in the early stage of TD and promoted in the recovery stage by modulating the expression of PG-related genes. Further, the rGSTA3 protein can modulate the expression of PG-related genes in erythrocytes and participate in the recovery of TD.

Endocrine Disrupting Compounds from the Source Water of the Huai River (Huainan City), China

The occurrence and environmental risk of eight endocrine disrupting compounds (EDCs), namely dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP), dibutyl phthalate (DBP), nonyl phenol (NP), bisphenol A (BPA), 17α-ethinylestradiol (EE2) and estrone (E1), from four water sources (Pingshantou, Wanfenggang, Shisi, and Shiyi) of Huai River (Huainan section) were investigated in this study. Except for DMP only found in Pingshantou, all of the selected EDCs existed widely in the source water. DMP, DEP, BBP, DBP, NP, BPA, EE2, and E1 had the ranges of nd (cannot be detected)-130 ng/L, 25-310, 76-1351, 431-1299, 215-627, 23-107, nd-0.174, and 0.143-0.334 ng/L, respectively. Therefore, the studied water sources were associated with notable levels of EDCs, wherein the concentrations of BBP, DBP, and NP were much higher than the other five chemicals. The selected EDCs appeared to be higher in upstream than in downstream (p < 0.05) for each water source, suggesting that EDCs were subjected to a decreasing with water flow. Correlation analysis suggests that DEP-BP-DBP, NP-BPA, and EE2-E1 might have the same sources, respectively; and the source of NP, EE2, and E1 was different from that of BBP, BEP and BBP, and DEP, respectively. It was observed that both the TAS (total ambient severity) and RQ (risk quotient) were less than 1, indicating that EDCs in Huai River (Huainan section) posed little or no thread to the health of local inhabitants and ecological environmental.

Heavy metals in the soils and plants from a typical restored coal-mining area of Huainan coalfield, China

This study was conducted to pursue the heavy metals in the soil and plants of a typical restored coal-mining area, China. The average concentrations of Cu, Zn, Cr, Ni, and Pb in soil were 26.4, 76.1, 188.6, 34.3, and 50.2 mg kg^-1, respectively, implying a significant accumulation of Cr, Ni, and Pb compared with the background values. Contamination factor indicates that the soil underwent none to medium pollution by Cu and Zn, medium to strong by Cr, none to strong by Pb, and medium pollution by Ni while the pollution load index means that the soil was subjected to intermediate contamination. Based on the critical threshold values to protect the plants, the investigated metals were unable to affect the plants. One-way ANOVA analysis shows that Cu, Zn, and Pb in plants varied with plant tissues. Cu-Cr, Cu-Ni, Zn-Ni, Zn-Pb, Cr-Ni, and Ni-Pb pairs had significant positive correlation both in soil and in plants due to the similar soil characteristics and plant physiologies. Correspondence analysis indicates that Pb was more likely to be accumulative in stems and leaves. In addition, the levels of Cu and Cr in plant followed an order of roots > stems > leaves; Zn and Ni leaves ≥ stems > roots; and Pb followed stems ≥ leaves > roots. Generally, this study suggests that the plants like Ligustrum lucidum Aiton and Weigela hortensis, which are capable of accumulating Cr, Ni, and Pb, should be the predominant species in the studied area.

Comparison of vertical and horizontal swimming behaviour of the weather loach Misgurnus anguillicaudatus

Experiments on the swimming kinetics and behaviour of weather loach Misgurnus anguillicaudatus showed that horizontal swim speed was significantly greater than swim speeds when ascending to or descending from the water surface to gulp air. Vertical swimming speeds during ascending or descending were similar. Misgurnus anguillicaudatus swam unsteadily during vertical movements compared with horizontal movements.

Quantitative Analysis of Unidirectional 2-D Tissue Formation of Endothelial Cells

We developed a reliable and quantitative method for measuring the dynamic process of unidirectional two-dimensional (2-D) tissue formation of endothelial cells (ECs) in vitro. The culturing of bovine ECs in an assembled culture chamber provided a square monolayered cell sheet with a linear margin when disassembled at the confluency. The cell sheet maintained in culture showed a unidirectional endothelialization in vitro. The cell population-distance histogram, which was determined from the daily observation of tissue, allowed us to determine quantitatively the dynamic process of unidirectional endothelialization in vitro. The endothelialized distance and the endothelializing zone on a glass slide were found to be nearly 500 μm/day and 750 μm in width, respectively. Thus, the method developed here provided information of the 2-D tissue formation process. This model would be useful as an in vitro model which simulates the anastomotic endothelialization of an artificial vascular graft.

An investigation into the relationship between water quality volume (design storage volume) and stormwater wetland performance

An investigation on free water surface wetland, which has an area of 0.23 ha and is employed to control the non-point source pollution from a watershed of 7.4 ha, was carried out to examine how the WQvr (the ratio of stormwater inflow volume to water quality volume (WQv)) affects the wetland treatment performance. As stormwater went through the wetland, TSS (total suspended solids), TCOD (total chemical oxygen demand), TN (total nitrogen) and TP (total phosphorus) were reduced by 85%, 57%, 6% and 68%, on average, respectively. Increase in the WQvr resulted in a decrease in the reduction efficiencies of TSS, TCOD and TP, but a slight increase in TN removal. WQv was identified as a useful parameter for the design of stormwater wetlands, as this volumetric design approach overcomes the variation in flow rate and pollutant concentrations with respect to time and rainfall conditions. However, the design goal of 80% TSS reduction was not accomplished as inflow water volume equal to designed WQv. On the other hand, it was found that TCOD and TP reduction could also be considered as wetland design goals together with TSS. However, TN reduction did not show any significant relationship with the WQv.

Risk Analysis of Metals in Soil from a Restored Coal Mining Area

This study was conducted to evaluate ecological impacts of metals in soil from the restored Panyi coal mining area of China. Zn, Cr, Ni, Pb and Cd had significantly accumulated in the studied soil compared with regional background values (p<0.05). Geo-accumulation indices indicate that the soil was at low risk for Cu, Zn, Ni and Pb contamination, while a low to moderate risk for Cr and Cd contamination existed. The ecological impact of all the selected metals was identified by ecological soil screening levels, apart from Cr, the impact of which was determined based on Dutch Target and Intervention Values. Results suggest that plants may be significantly affected by Ni, the avian population by Zn, Pb and Cd, while mammals are possibly influenced by Cd.

Experimental study on non-woven filamentous fibre micro-filter with high filtration speed

A laboratory study was undertaken to pursue the filter performance of a micro-filter module employing highly porous fibre media under a high filtration rate (≥1,500 m/day), faster than that of any conventional filter process. The effects of filtration rate, head loss, raw water turbidity, and filter aid chemicals on filter performance were analysed. In spite of the extremely high filtration rate, the filter achieved an attractive efficiency, reducing the raw water turbidity by over 80%. As with other filter systems, the filter aid used ((polyaluminium chloride (PAC)) greatly affected the performance of this particular fibre filter. Long-term repetitive runs were additionally carried out to confirm the reproducibility of the filter performance. Also, a comparison was carried out with other high-rate filter systems which are either being tested for use in experimental studies, or are already commercially available. This study reveals that the filter performance under a high filtration speed is still attractive especially as PAC is used. Due to the high porosity of the fibre, the filter had small head loss even though the filtration rate was high. These results ascertain that it is possible to operate the filters with high filtration rate achieving reliable treatment performance.

Effect of sampling duration on the performance evaluation of a stormwater wetland

In this study, the effect of sampling duration on the performance estimate for a stormwater wetland over both rainy and dry days was evaluated for the appropriate design of sampling duration. As the cumulative percentage volume (Vp), the ratio of cumulative stormwater volume concerning time to the total stormwater volume, varied between 60 and 100%, generally, the inflow total suspended solids, turbidity and total chemical oxygen demand (TCOD) event mean concentrations (EMCs) did not vary significantly, whereas the total nitrogen (TN) and total phosphorus (TP) EMCs were relatively stable. Compared to the inflow, the corresponding outflow EMCs changed much less as Vp changed. And these variations both from inflow and outflow EMCs did not result in significant changes in the removal efficiencies. The investigation during the dry days between two consecutive storm events showed that outflow pollutants did not change to a considerable extent after 1 day of the previous rainfall event. This study identifies the possibility of shortening the rainy sampling duration, because the performance of stormwater wetlands is usually estimated based on removal efficiencies rather than pollutant concentrations. Also, the sampling during dry days should be performed at least 1 day after a rainfall event.

ICRP Publication 125: Radiological Protection in Security Screening

The use of technologies to provide security screening for individuals and objects has been increasing rapidly, in keeping with the significant increase in security concerns worldwide. Within the spectrum of technologies, the use of ionizing radiation to provide backscatter and transmission screening capabilities has also increased. The Commission has previously made a number of statements related to the general topic of deliberate exposures of individuals in non-medical settings. This report provides advice on how the radiological protection principles recommended by the Commission should be applied within the context of security screening. More specifically, the principles of justification, optimisation of protection, and dose limitation for planned exposure situations are directly applicable to the use of ionising radiation in security screening. In addition, several specific topics are considered in this report, including the situation in which individuals may be exposed because they are concealed (‘stowaways’) in a cargo container or conveyance that may be subject to screening. The Commission continues to recommend that careful justification of screening should be considered before decisions are made to employ the technology. If a decision is made that its use is justified, the framework for protection as a planned exposure situation should be employed, including optimization of protection with the use of dose constraints and the appropriate provisions for authorisation and inspection.

Energy and ileal digestible amino Acid concentrations for growing pigs and performance of weanling pigs fed fermented or conventional soybean meal

A new strategy of co-inoculating Bacillus subtilis MA139 with Streptococcus thermophilus and Saccharomyces cerevisiae was used to produce fermented soybean meal (FSBM). Three experiments were conducted to determine the concentration of digestible energy (DE) and metabolizable energy (ME) (Exp. 1), apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids (AA) (Exp. 2), and feeding value (Exp. 3) of FSBM produced by this new strategy (NFSB) compared with soybean meal (SBM) and conventionally available FSBM (Suprotein). In Exp. 1, twenty-four barrows (initial body weight [BW] of 32.2 ±1.7 kg) were randomly allotted to 1 of 4 diets with 6 replicates per diet. A corn basal diet and 3 diets based on a mixture of corn and 1 of 3 soybean products listed above were formulated and the DE and ME contents were determined by the difference method. The results showed that there were no differences in DE and ME between SBM and either FSBM product (p>0.05). In Exp. 2, eight barrows (initial BW of 26.8±1.5 kg) were fitted with ileal T-cannulaes and used in a replicated 4×4 Latin square design. Three corn-starch-based diets were formulated using each of the 3 soybean products as the sole source of AA. A nitrogen-free diet was also formulated to measure endogenous losses of AA. The results showed that the SID of all AA except arginine and histidine was similar for NFSB and SBM (p>0.05), but Suprotein had greater (p<0.05) SID of most AA except lysine, aspartate, glycine and proline than NFSB. In Exp. 3, a total of 144 piglets (initial BW of 8.8±1.2 kg) were blocked by weight and fed 1 of 4 diets including a control diet with 24% SBM as well as diets containing 6% and 12% NFSB or 12% Suprotein added at the expense of SBM. During d 15 to 28, replacing SBM with 6% NFSB significantly improved average daily gain (ADG) and average daily feed intake (ADFI) (p<0.05) for nursery piglets. During the overall experiment, ADG of piglets fed diets containing 6% NFSB was significantly greater (p<0.05) than that of piglets fed SBM. In conclusion, fermentation with the new strategy did not affect the energy content or the AID and the SID of AA in SBM. However, inclusion of 6% NFSB in diets fed to nursery piglets improved performance after weaning likely as a result of better nutritional status and reduced immunological challenge.

Performance of a half-saturated vertical flow wetland packed with volcanic gravel in stormwater treatment

A half-saturated pilot-scale wetland planted with Acorus calamus was built to treat urban stormwater. The design comprises a sedimentation tank for pretreatment, and a vertical flow volcanic gravel wetland bed equipped with a recirculation device. Eighteen rainfall events were monitored in 2012. The treatment system achieved total removal efficiencies of 99.4, 81, 50, and 86% for suspended solids, organic matter, nitrogen and phosphorus, respectively, and 29, 68, and 25% for copper, zinc, and lead, respectively, at a 3-day hydraulic residence time. In the wetland bed, the removal of ammonia, total nitrogen, and zinc were improved by recirculation. Plant uptake provided 18% of nitrogen removal and 39% of phosphorus removal. During the experimental stage, only 1.4% of the pore volume in substrate was reduced due to clogging, implying that the wetland can operate without clogging for a relatively long period.

Performance of a vertical subsurface flow (VSF) wetland treatment system using woodchips to treat livestock stormwater

This study was conducted to develop a vertical subsurface flow (VSF) wetland remediation system packed with woodchips to control stormwater pollution arising from livestock agriculture. Three lab-scale VSF wetlands were operated with recirculation during the interval (Δ) between storms as 2, 4 and 8 days, respectively. The fed water was 100% recirculated one time per 24 h; the recirculation frequency was 1, 3 and 7 times at Δ of 2, 4 and 8 days, respectively. The constructed wetland systems proved to be effective in reducing total suspended solid (TSS), but also had potential for increasing TSS in the effluent due to the properties of the woodchips. The release of organic matter, especially in the dissolved form, occurred during the initial 60 days. The removal efficiencies of total nitrogen (TN) were 26.2%, 34.1% and 50.0% at Δ of 2, 4 and 8 days, respectively. Nitrification was promoted by the abundant oxygen supplied when the water in wetland was recirculated and fed into the wetland. Denitrification was stable and effective due to the availability of carbon sources. The influent total phosphorus (TP) was reduced from an average of 2.05 mg L(-1) to 1.79 mg L(-1), 1.36 mg L(-1) and 0.86 mg L(-1) at Δ as 2, 4 and 8 days, respectively. The result shows that woodchips can be used as substrate material for VSF wetland treatment systems to control nutrient influx from livestock stormwater.

Relationship between water quality parameters and the survival of indicator microorganisms - Escherichia coli - in a stormwater wetland

Indicator microorganisms - Escherichia coli - in a stormwater wetland controlling non-point source pollution in the Keum River basin was studied and the relationship between water quality parameters and the survival of E. coli was investigated by Pearson correlation analysis based on 16 sets of data collected on dry days. A significant seasonal variation of the density of E. coli was observed in the influent and effluent. A dominant decay of E. coli was found in almost all the wetland components. In the settling pond, the density was observed to vary negatively with pH and the removal of total suspended solids, and the decay was promoted by solar radiation. In the aeration pond, the survival of E. coli was encouraged negatively by the dilution effect, unfavorable increase of dissolved oxygen (DO) and sedimentation with coarse particles. In the marsh wetland, the reduction of E. coli was positively influenced by UV radiation, obvious increase of pH, DO and sedimentation with algae and particles. In the polishing pond, the introduction of E. coli with avian feces and growth of the bacteria were more prevalent than decay. Although this introduction or growth was almost negligible, further study will be conducted in the future.

Mechanisms that underlie the induction of vasodilation in pulmonary artery by rutin

AIM

Rutin, also known as violaguercitrin, is a bioflavonoid and has a wide range of biological activity. However, the effect of this compound on arteries is not elucidated. Therefore, the objective of this study was to investigate the mechanism underling the induction of vasodilation in pulmonary artery (PA) by the natural product, rutin.

METHODS

Firstly, the isometric tension of the artery rings was studied in vitro with force-electricity transducers. In PA endothelium-intact (EI) rings, rutin elicited concentration-dependent relaxation after the PA rings were pre-contracted by phenylephrine (PE), but induced mesenteric artery (MA) vasoconstriction. Inhibited the endothelial nitric oxide synthase (eNOS) by NG-Nitro-L-arginine Methyl Ester (L-NAME) or removed the PA endothelium would decrease the relaxation effect of rutin.

RESULTS

The NO production was increased in rutin-treated bovine pulmonary artery endothelial cells (BPAECs) detected by fluorescent probe 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate (DAF-FM), which verify the functional study results. Moreover, western blot analysis revealed that rutin increased the phosphorylation of eNOS at Ser 1177, but decreased the phosphorylation of eNOS at Thr 495, and did not affect the overall expression of eNOS.

CONCLUSION

These results suggested that rutin-induced relaxation of PAs share NO-eNOS activation pathways, including phosphorylation of Ser 1177, and dephosphorylation at Thr 495. Rutin also has specific action because it exerts a vasodilator influence on the PAs but not MAs.

Reelin deficiency causes specific defects in the molecular composition of the synapses in the adult brain

The extracellular protein Reelin regulates radial neuronal migration in the embryonic brain, promotes dendrite outgrowth in the developing postnatal forebrain, and strengthens synaptic transmission in the adult brain. Heterozygous reeler mice expressing reduced levels of Reelin are grossly normal but exhibit behavioral and physiological abnormalities. We previously demonstrated that dendritic spine density is reduced in the developing hippocampus of these mice. In this study, we investigated the consequence of Reelin deficiency on synapse formation in adult heterozygous reeler mice using imaging and biochemical approaches. Using a reeler colony that expresses yellow fluorescent protein in selected neurons, we analyzed spine density in hippocampal area CA1 by confocal microscopy and found modest abnormalities in heterozygous reeler mice. However, biochemical analysis of synaptic composition revealed specific postsynaptic defects in scaffolding proteins, neurotransmitter receptors, and signaling proteins. Using whole brain homogenates and purified pre- and postsynaptic fractions, we found that the defects were localized to the postsynaptic compartment of heterozygous reeler synapses. Decreased levels of postsynaptic density-95 (PSD-95), the N-methyl d-aspartate (NMDA) receptor subunits NR2A and NR2B, and the phosphatase PTEN were found specifically in the postsynaptic density fraction obtained from these mice. Furthermore, we found that PSD-95, NR2A, and PTEN interact with each other at the synapse. Finally, we show that levels of NR2A are reduced in conditional Pten knock out mice, demonstrating that the PTEN phosphatase regulates NMDA receptor expression at the synapse in vivo. These studies may provide insights into the etiology of cognitive disorders associated with deficiencies in Reelin signaling and PTEN dysfunction.

Spatiotemporal patterns of postsynaptic density (PSD)-95 expression after rat spinal cord injury

AIMS

Postsynaptic density (PSD)-95 is a scaffolding protein linking the N-methyl-D-aspartate receptor with neuronal nitric oxide synthase (nNOS), which contributes to many physiological and pathological actions. We here investigated whether PSD-95 was involved in the secondary response following spinal cord injury (SCI).

METHODS

Spinal cord contusion (SCC) and spinal cord transection (SCT) models at thoracic (T) segment 9 (T(9)) were established in adults rats. Real-time polymerase chain reaction, Western blot, immunohistochemistry and immunofluorescence were used to detect the temporal profile and spatial distribution of PSD-95 after SCI. The association between PSD-95 and nNOS in the injured cords was also assessed by coimmmunoprecipation and double immunofluorescent staining.

RESULTS

The mRNA and protein for PSD-95 expression were significantly increased at 2 h or 8 h, and then gradually declined to the baseline level, ultimately up-regulated again from 5 days to 7 days for its mRNA level and at 7 days or 14 days for its protein level after either SCC or SCT. PSD-95 immunoreactivity was found in neurones, oligodendrocytes and synaptic puncta of spinal cord tissues within 5 mm from the lesion site. Importantly, injury-induced expression of PSD-95 was colabelled by active caspase-3 (apoptotic marker), Tau-1 (the marker for pathological oligodendrocytes) and nNOS.

CONCLUSIONS

Accompanied by the spatio-temporal changes for PSD-95 expression, the association between PSD-95 and nNOS undergoes substantial alteration after SCI. These two molecules are likely to form a complex on apoptotic neurones and pathological oligodendrocytes, which may in turn be involved in the secondary response after SCI.

Natural Occurrence of Chilli veinal mottle virus on Capsicum chinense in China

An outbreak of a viral disease on chili pepper (Capsicum chinense Jacp. cv. Yellow Lantern) occurred in Hainan Province, China during 2003 and 2004. The disease was prevalent in five chili-producing counties surveyed. Leaves of infected plants initially displayed symptoms of dark green banding along veins and later became distorted with striking mosaic. Infected plants had reduced flower numbers and fruit set, resulting in a significant yield loss. The causative virus was characterized and identified as Chilli veinal mottle virus (ChiVMV) (3). An isolate of the virus was obtained via three single lesion passages through Chenopodium amaranticolor and was shown to reproduce the same symptoms on inoculated C. chinense cv. Yellow Lantern. Negative staining of crude extracts of the infected tissue and subsequent electron microscopy revealed flexuous rods of 12 to 13 × 750 nm, typical of a potyvirus. Pinwheel-like inclusion bodies were abundant in thin sections of infected leaves. Purified virus preparations contained one major protein of 32.8 kDa and one minor protein of 28 kDa when fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Both of these protein bands were excised and subsequently analyzed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Multiple peptide fragments from both proteins were identified as arising from ChiVMV capsid protein (CP) (1,2). Therefore, the 32.8-kDa protein is the full-length ChiVMV CP and the 28-kDa protein is presumably a degradation product of the CP. The combined biological and molecular data provided strong evidence that the viral disease on C. chinense was caused by ChiVMV. To our knowledge, this is the first report of ChiVMV infection on C. chinense in China and the first report of C. amaranticolor as an experimental host for ChiVMV. References: (1) P. Chiemsombat et al. Arch. Virol. 143:1855, 1998. (2). J. Joseph and H. S. Savithri. Arch. Virol. 144:1679, 1999. (3) P. Siriwong et al. Plant Pathol. 44:718, 1995.

Analyses of the effects of Rck2p mutants on Pbs2pDD-induced toxicity in Saccharomyces cerevisiae identify a MAP kinase docking motif, and unexpected functional inactivation due to acidic substitution of T379

Rck2p is a Ser/Thr kinase that binds to, and is activated by, Hog1p. Expression of the MAP kinase kinase Pbs2pDD from a GAL1-driven plasmid hyperactivates the HOG MAP kinase pathway, and leads to cessation of growth. This toxic effect is reduced by deletion of RCK2. We studied the structural and functional basis for the role of Rck2p in mediating the growth arrest phenotype associated with overexpression of Pbs2pDD. Rck2p kinase activity is required for the effect, because Rck2p(Delta487-610), as well as full-length Rck2p, is toxic with Pbs2pDD, but kinase-defective versions of either protein with a K201R mutation are not. Thus, the C-terminal portion of Rck2p is not required provided the protein is activated by removal of the autoinhibitory domain. Relief of inhibition in Rck2p normally requires phosphorylation by Hog1p, and Rck2p contains a putative MAP kinase docking site (TILQR589R590KKVQ) in its C-terminal segment. The Rck2p double mutant R589A/R590A expressed from a centromeric plasmid did not detectably bind Hog1p-GFP and was functionally inactive in mediating the toxic effect of Pbs2pDD, equivalent to an RCK2 deletion. However, overexpression of Rck2p R589A/R590A from a multicopy plasmid restored function. In contrast, RCK2-K201R acted as a multicopy suppressor of PBS2DD, markedly reducing its toxicity. This suppressor activity required the K201R mutation, and the effect was largely lost when the docking site was mutated, suggesting suppression by inhibition of Hog1p functions. We also studied the effect of replacing the predicted T379 and established S520 phosphorylation sites in Rck2p by glutamic acid. Surprisingly, the T379E mutant markedly reduced Pbs2pDD toxicity, and toxicity was only partially rescued by S520E. Rck2 T379E was sufficiently inactive in an rck2Delta strain to allow some cells to survive PBS2DD toxicity even when overexpressed. The significance of these findings for our understanding of Rck2p function is discussed.