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Laminaran is a major storage of carbohydrate in marine algae. Its high content and potential functions draw increasing attention. However, our understanding of its metabolisms and functions is still fragmented. After reviewing, marine algae exhibit a spectacular capacity of laminaran accumulation especially in the diatom Odontella aurita (65 % DW). Marine particulate organic carbon (POC) also has high contents of laminaran (42 ± 21 % DW). Laminaran shows a diel variation trend in marine algae, the content of which increases in the day but decreases at night. Laminaran also significantly accumulates in the stationary phase of algal growth. Furthermore, the metabolic pathway of laminaran and the remolding carbon mechanism in response to marine nitrogen limitation are proposed and comprehensively discussed. Laminaran production in marine phytoplankton is predicted to increase in future warmer and CO 2 -enriched oceans. Laminaran has diverse biological functions, including antioxidant, antimicrobial, anti-cancer, immunomodulatory, wound healing, and prebiotics. In addition, laminaran is also a major carbon storage compound in marine algae, suggesting its significant ecological function in marine carbon cycle. This study provides new insight into algal laminaran functions and its response mechanisms to environmental and climate changes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The status and ecological impacts of sedimentary elements of the marginal seas of Arctic and Northern Pacific Oceans was investigated during 2016 to 2018 by using inductively coupled plasma mass spectrometry. Industrial (0.006 mg kg -1 -64.6 g kg -1 ), precious (0.003-43.8 mg kg -1 ), rare earth (0.006-112.9 mg kg -1 ), and heavy metal (0.009-398.9 mg kg -1 ) elements showed spatial variation, and temporal uniformity. The results indicated ΣREEs and light REEs enrichment compared to chondrite and heavy REEs, respectively, while nonsignificant positive and negative δCe and δEu anomalies existed, respectively. High contamination and extreme enrichment of priority control, industrial (As, Mo, Re, Sb), precious (Au, Ir, Pd, Pt, and Ru) and RE elements indicated potential moderate to high ecological and biological risks. The study highlighted the ecological importance and fragile nature of these ecosystems and calls for an urgent action to ensure sustainability of these ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Diatom containing different active biological macromolecules are thought to be an excellent microbial cell factory. Phaeodactylum tricornutum, a model diatom, is a superb chassis organism accumulating chrysolaminarin with important bioactivities. However, the characteristic of chrysolaminarin accumulation and molecular mechanism of the fluctuated chrysolaminarin in diatom are still unknown. In this study, physiological data and transcriptomic analysis were carried out to clarify the mechanism involved in chrysolaminarin fluctuation. The results showed that chrysolaminarin content fluctuated, from 7.41 % dry weight (DW) to 40.01 % DW during one light/dark cycle, increase by day and decrease by night. The similar fluctuated characteristic was also observed in neutral lipid content. Genes related to the biosynthesis of chrysolaminarin and neutral lipid were up-regulated at the beginning of light-phase, explaining the accumulation of these biological macromolecules. Furthermore, genes involved in carbohydrate degradation, cell cycle, DNA replication and mitochondria-localized β-oxidation were up-regulated at the end of light phase and at the beginning of dark phase hinting an energy transition of carbohydrate to cell division during the dark period. Totally, our findings provide important information for the regulatory mechanism in the diurnal fluctuation of chrysolaminarin. It would also be of great help for the mass production of economical chrysolaminarin in marine diatom., Competing Interests: Declaration of competing interest The authors declare that there are no competing interest in this study., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Increased urbanization and anthropogenic activities can alter dissolved organic matter (DOM) and complicate its interaction with bacteria in rivers' ecosystems, however, there is limited information about how bacterial communities respond to DOM components in rivers with different urbanization levels. Here, we combined spectroscopy-based DOM analysis and 16S rRNA gene amplicon sequencing to investigate the associations of bacterial taxa and DOM properties as well as the impacts of DOM on bacterial niche breadth in North River (NR) and West River (WR) of Jiulong River watershed, southern China, which had low and high urbanization levels, respectively. Spectroscopy analysis showed that hydrophilic DOM was predominant in both rivers whereas chromophoric DOM was higher in WR. Network analysis indicated that only seven bacterial genera (i.e., hg clade, chthoniobacter, Geobacter, Acidibacter, Alphal Cluster, Fluviicola, and Lacunisphaera) showed strong associations with DOM optical variables in both rivers, whereas more than 85% of DOM-bacterial genera associations were different between rivers. These results suggest that the relationship between DOM and bacterial communities had different responses in rivers with different urbanization levels. The partial least square path model indicated that the total standardized effect of physico-chemicals on bacterial niche breadth was higher in NR (0.62) than in WR (0.35), whereas humic substances showed an opposite pattern (NR: -0.42; WR: 1.67). The distinct effects of physico-chemicals and DOM on bacterial niche breadths between rivers could be due to the different effects of urbanization and human activities on the environmental conditions of riverine ecosystems. Our findings revealed a huge dissimilarity in the bacteria-DOM co-occurrence networks between rivers with different urbanization levels and provide a novel insight that urbanization may enhance DOM's importance to bacterial niche breadths., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Numerous studies have revealed the spread mechanism of antibiotic resistance genes (ARGs) in single antibiotic-contaminated soils. However, the comprehensive impacts of heavy metals and antibiotics on ARGs and the underlying mechanisms are still unknown. Here, high-throughput quantitative PCR and high-throughput sequencing were used to investigate changes in ARGs and bacterial communities under various sulfamethoxazole (SMX) regimes (0, 1, 10, 50 mg kg -1 ) in arsenic (As) contaminated soils. The study found that the abundances of ARGs, mobile genetic elements (MGEs), and heavy metal resistance genes (HMRGs) significantly increased in the soil fortified at 10 and 50 mg kg -1 SMX concentrations. The ARGs abundance increased with the increase in the MGEs abundance. Many significant positive correlations between various ARGs subtypes and HMRGs subtypes were found. These results indicate that the HMRGs and MGEs positively contributed to the enrichment of ARGs in As-contaminated soils under SMX stress. Meanwhile, the abundance of copiotrophic (Actinobacteriota) reduced and oligotrophic (Gemmatimonadota) increased, indicating that the life history strategy of the community changed. In addition, Gemmatimonadota was positively correlated to ARGs, HMRGs, and MGEs, suggesting that Gemmatimonadota, which can cope with As and SMX stress, was the host for resistance genes in the soil. Finally, the study found that MGEs play a determinant role in ARGs proliferation due to the direct utilization of HGT, and the indirect effect for ARGs spread under a co-selection mechanism of ARGs and HMRGs, while the bacterial community showed indirect influences by altering environmental factors to act on MGEs. Collectively, this study revealed new insights into the mechanisms of resistance gene transmission under combined SMX and As contamination in soil ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The antibiotics released by human and animals end up in the environmental sinks like soil and water to cause contamination and induce resistance in the microflora. The knowledge of fate and behavior of antibiotics in diverse geographical, climatological, and physicochemical is limited. Therefore, present study investigated the spatial distribution of antibiotics and their relationship with various factors and the source-sink relationship between soil and poultry manure. This was achieved by employing spatially constrained hierarchical clustering, global and local spatial autocorrelation, and spatial regression techniques. Most of the antibiotics co-occurred in both soil and poultry manure matrices, however antibiotic concentration in soil (1.20 μg kg -1  < antibiotics ≤21.38 μg kg -1 ) was lower than that in the poultry manure (7.05 μg kg -1 < antibiotics ≤60.2 μg kg -1 ). Majority of the antibiotics showed spatial independence in both poultry manure and soil, except for sulfadiazine, sulfanilamide and sulfapyridine with Moran's I > - 0.111. Local indicator of spatial association indicated localized spatial clustering and outlier behavior of antibiotics. The underlying reasons for spatial heterogeneity of antibiotics resolved by spatial regression models indicated elevation, S%, C%, pH and mean annual temperature as the major factors. The influence of antibiotic concentration in poultry manure as a source was significant but marginal compared to the other predictors of spatial heterogeneity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Dissolved organic matter (DOM), known as a key to the aquatic carbon cycle, is influenced by abiotic and biotic factors. However, the compositional variation and these factors' effects on fluorescence DOM (FDOM) in urban rivers undergoing different anthropogenic pressure are poorly investigated. Herein, using fluorescence excitation-emission matrix and parallel factor analysis (EEM-PARAFAC), four FDOM components (C1, C2, C3, and C4) were identified in a less urbanized north river (NR) and a more urbanized west river (WR) of Jiulong River Watershed in Fujian province, China. C1, C2, and C4 were related to humic-like substances (HLS) and C3 to protein-like substances (PLS). HLS (63.9% in WR and 36.4% in NR) and PLS (62.7% in WR and 37.3% in NR) exhibited higher fluorescence in the more urbanized river. We also found higher PLS in winter, but higher HLS in summer for both rivers. Although the coefficient of variation indicated a difference in FDOM components stability to some extent between the two rivers, the typhoon event that occurred in summer had a stronger disruptive impact on the CDOM and FDOM of a more urbanized river than that of a less urbanized river. We explore abiotic and biotic factors' effects on FDOM using the partial least squares path model (PLS-PM). PLS-PM results revealed higher significant influences of biotic factors on FDOM in the more urbanized river. This study enhances our understanding of FDOM dynamics of rivers with different anthropogenic pressure together with the abiotic and biotic factors driving them., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objectives: The main objective of the study was to explore the factors to predict academic failure before the first major assessment., Methods: An exploratory qualitative study was conducted from March 2021 to August 2021 at Riphah International University. Using the purposive sampling technique, 16 students and seven teachers were included in the study. Eight online interviews were conducted with students who were academic failures and two focus group discussions were held with eight high achievers and seven teachers. The data was analyzed and thematic analysis was done., Results: Thematic analyses deduced relevant themes which were: Educational Journey Does past matter? Essential for learning, Personality and psychological make-up, and assessment of behaviour. The factors identified were performance record, learning difficulty, educational dislocation, missionless and purposeless, against free will, tuition, poor self-regulation, low effort, procrastination, non-reflective practice, cognitive load mismanagement, limited remediation, hesitant help-seeking, low self-efficacy, introvert behaviour, demotivation, emotional imbalance, observation of student behaviour, assessment of assigned task., Conclusion: Academic failure can be predicted early and salvaged., Competing Interests: Conflicts of interest: No conflict of interest is declared., (Copyright: © Pakistan Journal of Medical Sciences.)

The mutual interaction of a microalga Chlorella vulgaris with four antibiotics viz. sulfamethoxazole (SMX), trimethoprim (TMP), azithromycin (AZI), and levofloxacin (LEV) individually and in mixture was studied in batch culture. SMX, TMP, and LEV stimulated algal growth, while AZI inhibited its growth. The Combination Index (CI)-isobologram indicated antagonism of the antibiotic mixture on the growth of C. vulgaris. Higher removal efficiency was observed in the mixed antibiotic than in the single antibiotic batch cultures. Biodegradation was the main antibiotic removal mechanism with a similar antibiotic biosorption pattern in single and mix antibiotic cultures. Scanning electron microscopy and Fourier transform infrared spectrophotometry showed minor biochemical alterations on algal cells surface and a stable algal population. Monod kinetics model was successfully applied to understand the growth with respect to the removal efficiency of C. vulgaris in single and mix antibiotic batch cultures. Results indicated relatively higher specific growth rate in the mix antibiotic batch culture with removal efficiency in the order of SMX > LEV > TMP > AZI. In total, 46 metabolites with 18 novel ones of the four antibiotics were identified by using high-resolution mass spectrometry based on the suspect screening approach to propose the potential transformation pathways. Most of the transformation products demonstrated lower toxicity than their respective parents. These findings implied that C. vulgaris could be an outstanding candidate for advanced treatment of antibiotic removal in wastewater., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The distribution and fate of contaminants of emerging concern (CECs) was studied in relation to hydrological conditions, land use characteristics, and spatial contiguity in Houxi River. Thirty-four CECs were detected in the surface water during a three-year sampling campaign. Caffeine was most prevalent (99% frequency), while bisphenol A had the highest median concentration (78.2 ng/L) among the detected CECs. Caffeine and the other prevalent CECs lincomycin and bisphenol A, with median concentrations of 3.89 ng/L, 0.26 ng/L, and 78.2 ng/L, respectively, were positively correlated with land use types related to anthropogenic activities (grass, barren, built up, and cropland areas and landscape indexes for human activities). The analysis of similarities revealed significant annual variations, with increasing trends in both the concentrations and detection frequencies of CECs. Spatial variations were demonstrated by higher concentrations and detection frequencies downstream compared to upstream. The singular value decomposition analysis revealed that the downstream sites were the major contributors (55.6%-100%) to the spatial variability of most CECs. Moran's I analysis based on downstream contiguity indicated strong spatial autocorrelation among the connected sites for most CECs. This was further supported by longer correlation lengths for 18 CECs than the average distance between the sampling sites. The spatial autocorrelation can be attributed to the physicochemical properties of CECs and local hydrological dynamics, including temperature, wind speed, and sunshine hours. For most CECs, local contribution predominated over neighbor influence with an average value of 75.5%. The results of this study provide new insight to evaluate CEC distributions, which will be beneficial to policymakers for the management and prioritization of CEC contaminants in the Houxi watershed., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Marine sediments serve as a sink for contaminants of anthropogenic origin. Here, 25 major and trace elements were determined in surface and core sediments from an urban lagoon (Yundang Lagoon), China. The median concentrations of Pb, Cd, Cu, and Zn in both surface and core sediments exceeded global and crustal averages. Principal component analysis for the elements and ecological impact of the heavy metals indicated spatial heterogeneity in core sediments from different lagoon areas; however, no such pattern was observed in surface sediments. Geodetector analysis indicated spatial locations of lakes, pH, N%, C%, and S% as the major factors influencing the heterogeneity of potential ecological risk index, a cumulative measure of the ecological impact of heavy metal. The interaction detector indicated nonlinear and bivariate enhancement between different physicochemical parameters. Besides, a depth profile of the elements in different samples was also elucidated., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Rapid urbanization has resulted in pervasive occurrence of antibiotic resistance genes (ARGs) in urban aquatic ecosystems. However, limited information is available concerning the ARG profiles and the forces responsible for their assembly in urban landscape lagoon systems. Here, we employed high-throughput quantitative PCR (HT-qPCR) to characterize the spatial variations of ARGs in surface and core sediments of Yundang Lagoon, China. The results indicated that the average richness and absolute abundance of ARGs were 11 and 53 times higher in the lagoon sediments as compared to pristine reference Tibetan lake sediments, highlighting the role of anthropogenic activities in ARG pollution. Co-occurrence network analysis indicated that various anaerobic prokaryotic genera belonging to Alpha-, Deltaproteobacteria, Bacteroidetes, Euryarchaeota, Firmicutes and Synergistetes were the potential hosts of ARGs. The partial least squares-path modeling (PLS-PM) analysis revealed positive and negative indirect effects of physicochemical factors and heavy metals on the lagoon ARG profiles, via biotic factors, respectively. The horizontal (mediated by mobile genetic elements) and vertical (mediated by prokaryotic communities) gene transfer may directly contribute the most to drive the abundance and composition of ARGs, respectively. Furthermore, the neutral community model demonstrated that the assembly of sediment ARG communities was jointly governed by deterministic and stochastic processes. Overall, this study provides novel insights into the diversity and distribution of ARGs in the benthic habitat of urban lagoon systems and underlying mechanisms for the spread and proliferation of ARGs., (Copyright © 2020. Published by Elsevier B.V.)

Objective: To evaluate VMAT plans for conformity and homogeneity of radiation dose to the target in order to share our experience as a pioneering institute to use VMAT technology in Pakistan., Methods: Since December 2014 to January 2018, 530 patients of various anatomical sites were treated by VMAT technique at Neurospinal Cancer Care Institute (NCCI) Karachi Pakistan. ERGO++ planning system (Version 1.7.2) was used to develop VMAT plans with single or multiple arcs by the rotation of couch and gantry. The plans were evaluated by calculating Conformity Index (CI) and Homogeneity Index (HI) and critical organ (OARs) doses of individual tumor sites., Results: The average CI of various sites was 1.4 (range: 1.0-2.0) and average HI of various sites was 1.20 (range: 1.07-1.374), respective critical organ doses were adequately achieved., Conclusions: VMAT treatment planning technique showed good conformal and homogeneous target coverage with sparing of organs at risk and reduced treatment delivery time. With these features, safety of VMAT technique may allow its routine clinical use, though it is still under investigation in many areas., (Copyright: © Pakistan Journal of Medical Sciences.)

Environmental selection of antibiotic resistance genes (ARGs) is considered to be caused by antibiotic or metal residues, frequently used in livestock. In this study we examined three commercial poultry farms to correlate the co-occurrence patterns of antibiotic and metal residues to the presence of ARGs. We quantified 283 ARGs, 12 mobile genetic elements (MGEs), 49 targeted antibiotics, 7 heavy metals and sequenced 16S rRNA genes. The abundance and type of ARG were significantly enriched in manure while soil harbored the most diverse bacterial community. Procrustes analysis displayed significant correlations between ARGs/MGEs and the microbiome. Cadmium (Cd), arsenic (As), zinc (Zn), copper (Cu) and lead (Pb) were responsible for a majority of positive correlations to ARGs when compared to antibiotics. Integrons and transposons co-occurred with ARGs corresponding to 9 classes of antibiotics, especially Class1 integrase intI-1LC. Redundancy analysis (RDA) and Variance partitioning analysis (VPA) showed that antibiotics, metals, MGEs and bacteria explain solely 0.7%, 5.7%, 12.4%, and 21.9% of variances of ARGs in the microbial community, respectively. These results suggested that bacterial composition and horizontal gene transfer were the major factors shaping the composition of ARGs; Metals had a bigger effect on ARG profile than detected antibiotics in this study., Competing Interests: Declaration of competing interest We declare that no conflict of interest exits in this manuscript, and manuscript is approved by all authors for publication. This manuscript is original and has not been published in whole or in part previously., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Microeukaryotic communities are sensitive to environmental changes; and are considered essential for microbial food webs and biogeochemical cycles. Therefore, understanding the community responses of microeukaryotes to environmental changes is of great ecological significance. Very little is known about the assembly mechanisms underlying the microeukaryotic communities, especially for the key ecological groups (e.g., habitat generalists/specialists) in the riverine ecosystems. Here, we employed 18S rDNA amplicon sequencing to study the assembly processes governing the microeukaryotic communities and their habitat generalists and specialists across three hydrological seasons in a subtropical river in China. The results showed that deterministic and stochastic processes jointly shaped the microeukaryotic communities, where the relative importance of stochastic processes decreased in the following order: wet > normal > dry seasons. However, deterministic processes played more important role in shaping the microeukaryotic communities than those of prokaryotes. Meanwhile, stochastic and deterministic processes were responsible for structuring the microeukaryotic habitat generalists and specialists, respectively. Generally, the pure effects of physicochemical factors on the microeukaryotic communities and their key ecological groups were ~ 1.7 folds than those of the micropollutants. However, several micropollutants (e.g., acetaminophen, benzophenone-3, bisphenol A, sulfadiazine, triclocarban and triclosan) were found to have a strong effect on the habitat specialists. Altogether, we suggested that the ecological responses of the riverine microeukaryotes to micropollutants may vary among species due to the intrinsic differences in their environmental plasticity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Rivers are a significant reservoir of antibiotic resistance genes (ARGs), yet the biogeographic pattern of riverine ARGs and its underlying driving forces remain poorly understood. Here, we used metagenomic approach to investigate the spatio-temporal variation of ARGs in two adjacent sub-watersheds viz. North River (NR) and West River (WR), China. The results demonstrated that Bacitracin (22.8 % of the total ARGs), multidrug (20.7 %), sulfonamide (15.2 %) and tetracycline (10.9 %) were the dominant ARG types. SourceTracker analysis indicated that sewage treatment plants as the main source of ARGs, while animal feces mainly contributed in spreading the ARGs in the upstream of NR. Random forest and network analyses confirmed that NR was under the influence of fecal pollution. PCoA analysis demonstrated that the composition of ARGs changed along with the anthropogenic gradients, while the Raup-Crick null model showed that homogenizing selection mediated by class 1 integron intI1 resulted in stable ARG communities at whole watershed scale. Structural equation models revealed that microbial community, grassland and several non-antibiotic micropollutants may also play certain roles in influencing the distribution of ARGs. Overall, the observed deterministic formation of ARGs in riverine systems calls effective management strategies to mitigate the risks of antibiotic resistance on public health., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Micropollutants have become of great concern, because of their disrupting effects on the structure and function of microbial communities. However, little is known about the relative importance of trace micropollutants on the aquatic prokaryotic communities as compared to the traditional physico-chemical characteristics, especially at different spatial dimensions. Here, we investigated free-living (FL) and particle-associated (PA) prokaryotic communities in a subtropical water reservoir, China, across seasons at horizontal (surface water) and vertical (depth-profile) scales by using 16S rRNA gene amplicon sequencing. Our results showed that the shared variances of physico-chemicals and micropollutants explained majority of the spatial variations in prokaryotic communities, suggesting a strong joint effect of the two abiotic categories on reservoir prokaryotic communities. Micropollutants appeared to exert strong independent influence on the core sub-communities (i.e., abundant and wide-spread taxa) than on the satellite (i.e., less abundant and narrow-range taxa) counterparts. The pure effect of micropollutants on both core and satellite sub-communities from FL and PA fractions was ~1.5 folds greater than that of physico-chemical factors at the horizontal scale, whereas an opposite effect was observed at the vertical scale. Moreover, eight micropollutants including anti-fungal agents, antibiotics, bisphenol analogues, stimulant and UV-filter were identified as the major disrupting compounds with strong associations with core taxa of typical freshwater prokaryotes. Altogether, we concluded that the ecological disrupting effects of micropollutants on prokaryotic communities may vary along horizontal and vertical dimensions in freshwater ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A simultaneous extraction and cleanup method was optimized and validated for the determination of 40 antibiotics from cephalosporin, fluoroquinolone, lincosamide, macrolide, nitroimidazole, quinolone, sulfonamide and tetracycline groups in sediments by liquid chromatography with tandem quadrupole mass spectrometry (LC-MS/MS). The method involved hydration of freeze-dried sediment sample (2.0 g) with 2.5 ml of 0.1 M Na-EDTA McIlvaine buffer and extraction with 5 ml of MeOH and MeCN (1:3 v/v) followed by dispersive solid phase extraction by using 100 mg mix of C18 and PSA (1:2 w/w) and 50 mg MgSO 4 prior to LC-MS/MS analysis. The method was validated for 10, 20, 50 and 100 µg/kg spiking levels by using blank sediment sample obtained from a drinking water reservoir according to the guidelines of European Commission Decision (2002) 2002/657/EC. The method produced clean extracts with generally low matrix effect during LC-MS/MS analysis. The mean recoveries ranged between 24-162%, 48-151%, 51-159%, and 50-149% for 10, 20, 50 and 100 µg/kg spiking levels, respectively, with acceptable precision. The analytical method was sensitive enough to achieve 0.01-34.3 µg/kg and 0.03-115 µg/kg limits of detection and quantitation, respectively. The scope of the method was demonstrated by analyzing complex solid environmental matrices (chicken manure, swine manure, poultry feed and soil) spiked at 10, 20, 50 and 100 µg/kg levels. The method was also applied for the antibiotic analysis in samples with incurred residues. Different matrices in the order of the magnitude as sediments < poultry feed < swine manure < soil < chicken manure were detected with the residues of fluoroquinolone, macrolide, sulfonamide and tetracycline antibiotics., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A checklist of earthworm species hitherto recorded from North Eastern Region (NER) of India is presented. In total, 128 species/subspecies belonging to 26 genera spread over 9 families are listed. Of these, 72 species are recognized as endemics, 18 as near endemics, 5 as native peregrines and 32 as exotics. The checklist includes literature citation to the original description, type locality, important synonyms and the state-wise distributional records for each species/subspecies.

Dissipation potential of four algae viz. Haematococcus pluvialis, Selenastrum capricornutum, Scenedesmus quadricauda and Chlorella vulgaris was investigated against ten antibiotics (sulfamerazine, sulfamethoxazole, sulfamonomethoxine, trimethoprim, clarithromycin, azithromycin, roxithromycin, lomefloxacin, levofloxacin and flumequine) in a series of synthetic wastewater batch culture experiments, maintained at 20, 50 and 100 μg L -1 initial concentration levels and incubated over a period of 40 days. Generally, the antibiotic removal was achieved with overall dissipation percentage (%) varying among the algal species and different antibiotics. Biodegradation was the major antibiotic removal mechanism from the dissolved fraction, with minor contributions of bioadsorption, bioaccumulation, and abiotic factors. The antibiotics dissipation followed the pseudo-first-order-kinetics with the fastest antibiotic degradation rate achieved by H. pluvialis. The Monod kinetics was successfully applied to explain the relationship between the algal growth and the removal of antibiotics and nutrients in the batch cultures. S. capricornutum and C. vulgaris showed more affinity for the macrolides and fluoroquinolones than sulfonamides, while, H. pluvialis and S. quadiricauda showed relatively higher preference for sulfonamides than the other antibiotic groups. A total of 10 transformation products were identified and the transformation pathway was proposed, accordingly. Most of the transformation products had lower toxicity compared with their parent antibiotics., Competing Interests: Declaration of Competing Interest The authors declare that there are no conflicts of interest., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Residues of bisphenol A (BPA) are ubiquitously detected in the surface water due to its widespread usage. This study systematically investigated the dissipation and kinetics of BPA under simulated hydrolysis, direct and indirect photolysis, bacterial degradation, microbial degradation and natural attenuation in microcosm. Structural equation modeling (SEM) by using partial least square method in path coefficient analysis suggested that the microbial degradation was the major factor involved in the natural attenuation of BPA. The potential transformation products were identified by using liquid chromatography high-resolution mass spectrometry (LC-HRMS) and stable isotope tracing technique by simultaneous performing gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) and gas chromatography mass spectrometry (GC-MS). A total of fourteen including three novel transformation products of BPA were identified to indicate five possible pathways. An increased yield of labeled (δ 13 C) CO 2 and detection of 13 C-labeled phospholipid fatty acids (PLFAs) indicated the mineralization of BPA and possible utilization of BPA or its transformation products by microbes for cellular membrane synthesis, respectively., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Increasing extreme precipitation events (EPEs) can induce biogeochemical disturbances in the coastal lagoon ecosystems. Very little is known about the response of prokaryotic communities to such influences, which are the key components mediating the biogeochemical cycling in lagoons. Here 16S rRNA gene amplicon sequencing and high-through quantitative PCR (HT-qPCR) were employed to investigate the distribution of prokaryotic communities and fecal indicator genes in the surface waters of Yundang lagoon, Xiamen, China during EPEs, respectively. Prokaryotic communities from rainwaters, influents (IFs) and effluents (EFs) from a nearby wastewater treatment plant were also characterised. The results indicated a significant variation in the composition of lagoon prokaryotic communities compared with rainwaters, IFs and EFs. Multivariate and phylogenetic signal analyses revealed that environmental filtering, mainly controlled by salinity, was the major ecological process responsible for the temporal succession of lagoon prokaryotic communities during EPEs. Moreover, the pollution indicator taxa (based on amplicon sequencing) and fecal indicator genes (based on HT-qPCR) demonstrated that EPEs may induce sewage overflows and fecal pollution (mainly from humans and dogs), resulting in an increase in the relative abundance of pollution indicator taxa and genes in Yundang lagoon. Network analysis illustrated that the number of network edges and keystone species decreased along the sampling times, implying that EPEs-induced disturbances may affect prokaryotic species associations. Taken together, this study provides an enhanced understanding of the responses of lagoon prokaryotic communities to EPEs-induced disturbances., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Coastal sands harbor diverse microbial assemblages that play a critical role in the biogeochemical cycling of beach ecosystems. However, little is known about the relative importance of the different ecological processes underlying the assembly of communities of sand microbiota. Here, we employed 16S rDNA amplicon sequencing to investigate the sand microbiota of two coastal beaches, in southern China. The results showed that sand microbial assemblages at intertidal and supratidal zones exhibited contrasting compositions that can be attributed to environmental filtering by electric conductivity. A consistent pattern of habitat generalists and specialists of sand microbiota was observed among different beach zones. Null and neutral model analyses indicated that the environmental filtering was mainly responsible for supratidal microbial communities, while the neutral processes could partially influence the assembly of intertidal communities. Moreover, environmental filtering was found to shape the habitat specialists, while random dispersal played a major role in shaping generalists. The neutral model analysis revealed that the habitat generalists exceeding the neutral prediction harbored a relatively higher proportion of microbial taxa than the specialist counterparts. An opposite pattern was observed for taxa falling below the neutral prediction. Collectively, these findings offer a novel insight into the assembly mechanisms of coastal sand microbiota., Competing Interests: The authors declare no conflict of interest.

Carbamates are synthetic pesticides, extensively used throughout the world due to their broad specificity against various insect pests. However, their enormous and inadequate use have made them a potential threat to the environment. At low temperature, degradation of carbamates becomes difficult mainly because of low biological activity. In the present study, we isolated a bacterial strain from a low temperature climate where the N- methylated carbamates are used for crop protection. The bacterium, was identified as Pseudomonas plecoglossicida strain (TA3) by 16S rRNA analysis. Degradation experiments with both free and immobilized cells in minimal salt medium indicated that the strain TA3 utilized carbaryl, carbofuran and aldicarb as both carbon and nitrogen source. TA3 can grow well at 4 °C and demonstrated the ability to degrade three carbamates (50 μgml -1 ) at low temperature. The immobilized cells were found more efficient than their free cells counter parts. Immobilized cells has ability to degrade 100% of carbamates at 30 °C while 80% at 4 °C but incase of their free cells counter parts the efficiency to degrade carbamates was less which was 60% at 4 °C and 80% at 30 °C. TA3 free cellsextract also depicted high activity against all the three carbamates even at 4 °C indicating a possible enzymatic mechanism of degradation., (© 2019 The Authors.)

Wastewater treatment plants (WWTPs) rely mainly on the microbial assemblages to contribute significantly for the removal of organic pollutants and nutrients. However, limited information is available on the ecological driving forces underlying the turnover of prokaryotic communities across wastewater treatment processes (i.e., from influents (IFs) and effluents (EFs)) within WWTPs. Here, we used a combination of the 16S rRNA gene amplicon sequencing and a quantitative ecological null model analysis to explore the ecological processes governing the turnover of the prokaryotic communities and the dominant taxonomic taxa across wastewater treatment processes of five full-scale WWTPs in China. Our results indicated that a significant variation in the composition of prokaryotic communities and the dominant taxa between IFs and EFs. The analysis of the environmental sources of indicator OTUs showed that a relatively lower abundance of the sludge/sewage and human guts associated OTUs in EFs than in IFs. Ecological null models revealed that among the ecological processes, deterministic processes were dominant in controlling the turnover of the overall communities from IFs to EFs, whereas the relative importance of deterministic processes varied among the dominant taxa (i.e., Bacteroidetes > Proteobacteria > Gammaproteobacteria > Firmicutes > Betaproteobacteria). However, the assembly of IF and EF communities was influenced mainly by the deterministic and stochastic processes, respectively. In addition, our results indicated that EF communities have a higher phylogenetic diversity than those of the IF communities, but the abundance of prokaryotic 16S rRNA genes was lower in EFs than in IFs. Overall, our study provides a novel insight of the assembly mechanisms underlying the turnover of prokaryotic communities during wastewater treatment processes.

In the present study, 13 endocrine disrupting compounds (EDCs) and their transformation products (TPs) were monitored in Jiulong River and its estuary, China in different seasons. The analytes included antimicrobials [triclosan (TCS) and triclocarbon (TCC)]; estrogens [estrone (E1), estradiol (E2), estriol (E3) and ethinylestradiol (EE2)]; alkylphenol ethoxylates [4-n-nonylphenol (NP) and 4-n-octylphenol (OP)] and the TPs [methyl triclosan (MeTCS), carbanilide (NCC), dichlorocarbanilide, 4-hydroxy estrone (4-OH E1) and 4-hydroxy estradiol (4-OH E2)]. A significant seasonal variation was observed for most EDCs. Approximately, 79% of the total E2 residues were detected in the normal season in comparison with the wet season to indicate recalcitrant behavior of E2 during the normal season. Risk assessment revealed that E2 was most potent among the EDCs to cause highest risk to both vertebrate and invertebrate aquatic species, whereas, E1, EE2, MeTCS and TCS also showed relatively high risk for some surface water aquatic species., (Copyright © 2019. Published by Elsevier Ltd.)

A quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based extraction and simultaneous dispersive solid-phase extraction (dSPE) clean-up method was developed for contaminants of emerging concern (CECs) in sediment samples. Hydration with a phosphate buffer (pH 2.0) and salting out with NaCl and MgSO 4 facilitated the extraction and liquid-liquid portioning of the aqueous and organic phases. Cleanup of the extracts was achieved by florisil and C18 (1:1) sorbents in dSPE with minimal compromise of the analytes. The extracts were clean enough for determination by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The procedure was validated for preservatives, blood lipid regulators, analgesics and anti-inflammatory drugs, plasticizers, and other classes of CECs in sediment matrix spiked at 6 levels between 1- and 40-fold concentrations for CECs of varying analytical sensitivities. The recovery values were generally between approximately 27 and 120% and the relative standard deviation (%RSD) values were below 20% at 10- , 20- , and 40-fold spiking levels, albeit the recoveries for some analytes dropped at low spike concentrations. The method showed high sensitivity where the method detection limits (MDLs) were at low ppb levels for the majority of the analytes that ranged between 0.002 and 1.93 µg/kg. The method performance was also compared with well-established US Environmental Protection Agency (USEPA) Method 1694 by analyzing sediment samples collected from Yundang Lagoon (Xiamen, China) with field-incurred CEC residues. The sediment samples were detected with residues of parabens, gemfibrozil, ketoprofen, naproxen, fenoprofen, diclofenac, miconazole, carbamazepine, benzophenon-3, glibenclamide, sildinafil citrate, and some bisphenol analogues. Environ Toxicol Chem 2019;38:1409-1422. © 2019 SETAC., (© 2019 SETAC.)

Limited information is currently available on the assembly processes (deterministic vs. stochastic) shaping the compositions of key microbial communities in activated sludge (AS). The relative importance of deterministic and stochastic processes for key bacterial and archaeal assemblages (i.e., core-satellite and habitat generalist-specialist) in AS from 13 wastewater treatment plants in China was investigated using 16S rDNA amplicon sequencing. The results obtained indicated 1,388 and 369 core operational taxonomic units (OTUs), 1,038 and 1,683 satellite OTUs, 255 and 48 habitat generalist OTUs, and 192 and 111 habitat specialist OTUs for Bacteria and Archaea, respectively. The proportions of shared OTUs between core and habitat specialist communities were similar to or higher than those between core and habitat generalist communities, suggesting a stronger inter-linkage between the former two groups. Deterministic processes, indicated by abundance-based β-null models, were responsible for shaping core communities, in which NH 4 -N, OrgC/OrgN, Cr, and Ni were the main controlling factors. In contrast, satellite communities were predominantly influenced by stochastic processes. Moreover, we found that deterministic and stochastic processes were mainly responsible for shaping the assembly of habitat specialists and generalists, respectively. However, the influence of deterministic factors on habitat specialists remains unclear. The present study provides novel insights into the assembly mechanisms of AS microbial communities.

The urban water ecosystems, such as the landscape ponds are commonly considered under the influence of anthropogenic disturbances, which can lead to the deterioration of the water quality. The prokaryotic communities are considered as one of the best indicators of the water quality. However, there are significant gaps in understanding the ecological processes that shape the composition and function of prokaryotic communities in the urban water ecosystems. Here, we investigated the biogeographic distribution of prokaryotic assemblages in water environments including landscape ponds, drinking water reservoirs, influents (IFs) and effluents (EFs) of wastewater treatment plants of a coastal city (Xiamen), China, by using 16S rDNA amplicon sequencing. Our results indicated that the ponds had higher α-diversity of prokaryotic communities than those in the reservoirs, while there were significant variations in the community compositions among ponds, reservoirs, IFs and EFs. Moreover, ponds harbored a significantly higher proportion of sewage- and fecal-indicator taxa than those in the reservoirs, suggesting the occurrence of exogenous pollution in the urban ponds. Null model analysis revealed that dispersal limitation was the main ecological processes resulting in the divergence of prokaryotic community compositions between ponds and other environments, while dispersal limitation and variable selection played an essential role in the formation of unique prokaryotic assemblages in the reservoirs. Function predication analysis demonstrated that the ponds shared more similar functional profiles with IFs or EFs (e.g., chemoheterotrophy, fermentation, chlorate reducers, nitrate reduction and respiration) than the reservoirs, whereas dominance of photoautotrophy was observed in the reservoirs. Overall, this study provides a profound insight of the ecological mechanisms underlying the responses of prokaryotic communities in the urban landscape ponds to the anthropogenic disturbances., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Limited information about the sludge quality is a major constraint for its usage and proper disposal. This study investigated the occurrence of 49 elements in sludge from 11 wastewater treatment plants (WWTPs) in Chongqing and Xiamen cities of China. The concentration of 46-detected elements ranged from 16.2 μg kg -1 (Pt) to 55.0 g kg -1 (Al) on dry solid basis in the sludge. The enrichment factor of most of the elements was > 1.5, indicating their possible anthropogenic origin. The precious metals had considerably higher enrichment factor ranging from 56.3 to 200,000. Principal component analysis clustered the samples from Chongqing and Xiamen separately to suggest strong spatial variations. Contamination factor, pollution loading index, and integrated pollution degree were calculated to evaluate the elemental pollution risk. The pollution loading index indicated unpolluted to highly polluted levels of the elements in the sludge. In addition, results from the ecotoxicological risk index showed an individual low to very high ecotoxicological risk posed by eight metal(loid)s (As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn) in the WWTPs.

Sulfamethoxazole (SMX) is a sulfonamide antibiotic, widely used as curative and preventive drug for human, animal, and aquaculture bacterial infections. Its residues have been ubiquitously detected in the surface waters and sediments. In the present study, SMX dissipation and kinetics was studied in the natural water samples from Jiulong River under simulated complex natural conditions as well as conditions to mimic various biotic and abiotic environmental conditions in isolation. Structural equation modeling (SEM) by employing partial least square technique in path coefficient analysis was used to investigate the direct and indirect contributions of different environmental factors in the natural attenuation of SMX. The model explained 81% of the variability in natural attenuation as a dependent variable under the influence of sole effects of direct photo-degradation, indirect photo-degradation, hydrolysis, microbial degradation and bacterial degradation. The results of SEM suggested that the direct and indirect photo-degradation were the major pathways in the SMX natural attenuation. However, other biotic and abiotic factors also play a mediatory role during the natural attenuation and other processes. Furthermore, the potential transformation products of SMX were identified and their toxicity was evaluated., (Copyright © 2018 Elsevier B.V. All rights reserved.)

We investigated the occurrence, removal and mass balance of 8 endocrine disrupting compounds (EDCs), including estrone (E1), estradiol (E2), estriol (E3), ethinylestradiol (EE2), triclosan (TCS), triclocarbon (TCC), 4-n-nonyl phenol (NP) and 4-n-octyl phenol (OP), along with 5 of their transformation products (TPs), including 4-hydroxy estrone (4-OH E1), 4-hydroxy estradiol (4-OH E2), methyl triclosan (MeTCS), carbanilide (NCC), dichlorocarbanilide (DCC) in a wastewater treatment plant. Generally, E3 showed the highest concentrations in wastewater with median value of 514 ng/L in influent, while TCS and TCC showed highest level in sludge and suspended solids (SS) with median value of 960 and 724 μg/kg, respectively. Spatial variations were observed along each unit of the wastewater treatment processes for dissolved analytes in wastewater and adsorbed analytes in suspended solids and sludge. Special emphasis was placed to understand the mass load of EDCs and their TPs to the wastewater treatment unit and mass loss during the wastewater treatment processes. Mass loss based on both aqueous and suspended phase concentration revealed that majority of these chemicals were significantly removed during the treatment process except for TCS, TCC, and three of their TPs (MeTCS, NCC, DCC), which were released or generated during the treatment process. Mass load results showed that 42.4 g of these EDCs and their TPs entered this wastewater treatment system daily via influent, whereas 6.15 g and 7.60 g were discharged through effluent and sludge., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The occurrence and fate of pharmaceuticals and personal care products (PPCPs) was investigated in seven wastewater treatment plants (WWTPs) in Xiamen City, China. Special emphasis was placed on their co-occurrence and the mass balances of both dissolved and adsorbed PPCPs in influent, effluent, and sludge samples. Results showed that PPCPs were widely detected and their co-occurrence was observed both in the wastewater and sludge that can be attributed to either their similar usage or similar physicochemical properties. These results further emphasize that some specific PPCPs have the potential as indicators or surrogate compounds to reduce the number of targeted PPCPs. The occurrence and distribution of PPCPs also showed strong spatial variations, as the PPCP mass loads per inhabitant were positively correlated with the urbanization levels. Both the removal efficiencies of dissolved PPCPs from the aqueous phase and mass loss proportion of the total PPCPs were evaluated and compared. Overall, a measured total amount of 8500 g PPCPs entered the seven WWTPs daily via influent with 6640 g in the dissolved form, while 3450 g left the WWTPs. The large mass loads of antibiotics in the sludge and effluents indicated their potential adverse effects to the receiving environment., (Copyright © 2018 Elsevier B.V. All rights reserved.)

We investigated selected chlorinated pollutants (β-HCH, γ-HCH, DDDs, DDEs, o,p'-DDT, p,p'-DDT, heptachlor, aldrin, dieldrin, and endrin) in the Lahore and the Sialkot districts of Pakistan, using eggs of cattle egret (Bubulcus ibis) collected during May and June 2007. The pollutant with highest level and frequency was ΣDDT, followed by β-HCH, γ-HCH, heptachlor, aldrin, dieldrin, and endrin in descending order. The concentration(s) were significantly higher in Sialkot heronry for all the pollutants (except p,p'-DDT) than in Lahore. The values for DDTs, β-HCH, γ-HCH, and heptachlor were significantly higher (p < 0.05) in the egg(s) than in sediment(s) and in the chicks' diet, due to biomagnification. Among DDTs analogues, p,p'-DDD was the major contaminant with >60 % of total DDT burden, reflecting the widespread aged as well as recent use of DDT as well as anaerobic degradation (DDD/DDE > 1 in many cases) in the nearby paddy soils. In few samples, p,p'-DDT/(DDD + DDE) > 0.5 suggested the recent emission patterns from surrounding contaminated areas of demolished DDT units and obsolete pesticide stores. The higher levels of HCHs (i.e., β-HCH) in the samples collected from Sialkot indicate exposure from long-term agricultural use. Overall, concentrations of all studied POPs were less than the threshold levels known to affect reproduction. Nevertheless, total DDTs and/or HCHs burdens in some eggs contained concentrations of greater than what would educe adverse effects on birds. This is among few studies on OCPs exposure to avian species, which provide the evidence of Pakistan's contribution toward the Global POPs emission.

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were investigated in eleven edible fish species (5 herbivorous and 6 carnivorous) collected from the River Chenab, Pakistan, during 2007-2009. Total OCP and PCB concentrations (ng g(-1) wet weight, ww) ranged between 13-107 (mean: 38) and 3.1-93.7 (mean: 20) for five herbivorous fish species and 21.6-365 (mean: 148) and 2.5-108 (mean: 30) for six carnivorous species, respectively. The trends of detected organochlorine pesticides (OCPs) in fish samples were: DDTs>PCBs>chlordanes>HCHs. The mean concentration(s) (ng g(-1) ww) of OCPs were relatively higher in all fish species collected near industrial areas followed by urban and agricultural areas. Risk assessment of OCPs and PCBs indicated that fish intake may pose health risk to humans with a consumption rate of >8 g/person/day. The hazardous ratios for the 50th and 95th percentile data of OCPs and PCBs in fish exceeded the value of 1, suggesting that the daily exposure to OCPs and PCBs yield a lifetime cancer risk greater than 1 in 10,000., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Objective: To evaluate the clinical outcome of linear accelerator based multisession stereotactic radiosurgery (SRS) for large benign brain tumors of >3cm., Methods: Between June 2009 and May 2011, 35 patients having large benign brain tumors of >3cm (≥15 cm 3 ) were treated by multisession stereotactic radiosurgery. This retrospective study was carried out at Neurospinal & Medical Institute Karachi. There were 17 (48.6 %) males and 18(51.4 %) females. Median age was 36 years (range: 13-65 years). Median target volume was 49.4 cm 3 (range: 15-184 cm 3 ). The median marginal dose was 25 Gy (range: 20-27.5Gy) prescribed to a median 75% isodose line (range: 65-100 %). Median number of 5 fractions were used ranging 3-5 fractions., Results: All the patients tolerated treatment very well. 21 (58.3%) patients had remarkable clinical improvement of neurological symptoms, 14 (38.9%) patients had stable symptoms, and only one patient had transient worsening of symptoms. No permanent neurological damage or radiation injury was seen. Radiologically, 9 (25.7%) patients achieved reduction in size of the tumor, 26(74.3 %) patients were having stable disease, and overall control rate was found to be 100 %. Median follow-up time from the end of SRS was 6.4 months (range: 1-22.5months)., Conclusion: Linear accelerator based multisession stereotactic radiosurgery for large benign brain tumors of >3cm is effective and well tolerated.

We present a case of follicular dendritic cell sarcoma in a 48 years old Saudi female who reported with slowly progressive right sided extranodal neck mass associated with pulmonary metastasis. Clinical examination, histopathologic features including distinct immunostains combine together to make the rare diagnosis of follicular dendritic cell sarcoma. This entity is often misdiagnosed due to non-consideration in differential diagnosis of sarcoma. It carries a significant potential for regional as well as distant spread and hence categorized as intermediate risk malignancy. Clinical, histopathological and immunohistochemical aspects and therapeutic options of this unusual case are discussed.

Objective: To determine the 30 days outcome measured in terms of morbidity and mortality in cases of ventricular septal defect (VSD) with increased pulmonary vascular resistance (PVR) managed with double flap patch closure., Study Design: Case series., Place and Duration of Study: Armed Forces Institute of Cardiology (AFIC/NIHD), Rawalpindi, from December 2005 to December 2008., Methodology: Forty patients with VSD having PVR 9.58 + 4.33 wood units underwent double flap patch closure. The patch was fenestrated as one half of the expected aortic annulus diameter. A separate flap patch 5 mm larger than fenestration was attached to superior upper one third margins of fenestration. The patch was placed with flap to open towards the left ventricular apex. Modified ultra filtration (MUF) was employed in every case and sildenafil was given postoperatively., Results: The age of patients ranged from 1 to 28 years with a mean of 6.66 + 5.70 years. There were 22 males and 18 females. All patients were weaned off from inotropic and ventilatory support as earlier as possible postoperatively with intensive care unit (ICU) stay of 77.15 + 54.56 hours. Postoperative pulmonary artery pressures were reduced to 42.63 + 10.86 mmHg as compared to pre-operative pulmonary artery pressures of 88.3 + 15.2 mmHg. Postoperatively 11 patients with suprasystemic pulmonary artery pressures and desaturation went into pulmonary hypertensive crisis in which immediate 2D echo evidenced the functioning flap valve with right to left shunt. There was only one death (early) out of 40 patients with an overall mortality of 2.5% along with limited morbidity., Conclusion: Double flap patch is an inexpensive, easy to construct technique with low morbidity and mortality in cases of VSD with raised PVR.

Objective: To determine the role of remote ischemic pre-conditioning (rIPC) on myocardium, against ischemia reperfusion injury in patients undergoing coronary artery bypass graft (CABG) surgery by measuring CKMB levels., Study Design: A randomized controlled trial., Place and Duration of Study: The Surgical Department of Armed Forces Institute of Cardiology/National Institute of Heart Diseases, Rawalpindi, from January to June 2008., Methodology: One hundred patients with double and triple vessels coronary artery disease were randomized in two groups of 50 each. rIPC protocol consisted of 3 x 5 minutes of forearm ischemia, induced by a blood pressure cuff inflated to 200 mmHg, with an intervening 5 minutes of reperfusion, during which the cuff was deflated. Patients in the control group were not subjected to limb ischemia. The protocol of induced ischemia was completed before placing patients on extracorporeal bypass circuit. At the end of surgery serum CKMB levels were measured and compared at 8, 16, 24 and 48 hours from both the groups. Written informed consent was taken from patients. Study was approved by the hospital ethical committee., Results: Remote ischemic pre-conditioning significantly reduced CKMB levels at 8, 16, 24 and 48 hours after surgery with p-values of 0.026, 0.021, 0.052 and 0.003 respectively. There was mean reduction of 3 iu/l in CKMB levels, in patients who underwent rIPC protocol prior to CABG surgery, compared to control group., Conclusion: This study showed a significant reduction of enzyme marker CKMB in patients subjected to rIPC prior to CABG surgery. This suggests lesser degree of myocardial damage compared to control group in CABG patients.

Objective: To determine the radiologic downstaging and histological response after neo-adjuvant concurrent chemoradiation in locally advanced rectal cancers., Study Design: Case series., Place and Duration of Study: Radiation Oncology department of Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, from December 2004 to November 2005., Methodology: Thirty patients with histopathologically confirmed locally advanced carcinoma rectum who had not received any treatment (chemotherapy, radiotherapy or surgery) prior to presentation were enrolled. Radiation therapy was delivered with a three-field technique to a dose of 50.4 Gy over 5 weeks at the rate of 1.8 Gy/day. Two cycles of chemotherapy were given synchronously, which comprised of 5-fluorouracil 350 mg/m2 and folinic acid 20 mg/m2 continuous intravenous infusion over first five days and last five days of radiotherapy. Surgery was planned 4-6 weeks later to chemoradiation after radiologic post therapy staging. Viable specimens were identified and toxicity was observed., Results: All patients completed treatment without modification. Radiologic downstaging was found in 56.7%, stable disease was seen in 30.0% and progressive disease was present in 13.3% of the patients. Radiologically complete resolution of tumour was not observed. Pathological complete resolution of tumour was achieved in 3.3% and near complete resolution was observed in 13.3% of the patients. In 86.6% cases, a total gross tumour resection with no macroscopic residual disease was possible. All the patients tolerated the treatment well., Conclusion: Neo-adjuvant chemoradiation for locally advanced rectal cancers is associated with high resectability rate and is relatively safe with acceptable morbidity which favours its use in future.

Objective: To determine the efficacy of bidirectional Glenn shunt (BDG) without cardiopulmonary bypass (CPB)., Study Design: Quasi experimental study., Place and Duration of Study: The Armed Forces Institute of Cardiology and National Institute of Heart Diseases (AFICNIHD), Rawalpindi., Methodology: Thirty one patients underwent BDG without CPB between January 2006 to December 2007. Subjects for off pump BDG were those who did not require any intracardiac repair, had good sized branch pulmonary arteries, had acceptable PA pressures (< 16 mm Hg), and did not have any significant atrio-ventricular (AV) valve regurgitation. The off pump BDG was performed using veno-venous shunt between the superior vena cava (SVC) and right atrium (RA) following heparinization. All patients underwent discharge echocardiography to assess BDG patency. Statistical significance was determined using t-test with statistical significance at p < 0.05., Results: There were 18 males and 13 females. All patients survived. Twenty seven (87.09%) patients received BDG and 04 patients (12.90%) received bilateral BDG. Atrial septectomy with inflow occlusion was performed in 5 patients. Antegrade pulmonary blood flow was left in 24 (77.41%) of 31 patients. There was significant improvement in postoperative SpO2 (p = 0.000) in all the cases. There were no postoperative neurologic complications. Sepsis occurred in 2 patients who ultimately recovered. One patient had chylothorax which stopped after three (03) days in ICU. No SVC/PA distortions were noted by discharge echocardiography. Eliminating CPB reduced the cost of the procedure substantially and saved the patients from its inherent complications., Conclusion: BDG without CPB is a safe procedure in selected patients. It avoids CPB related problems and is cost effective, with excellent results.

Objective: To determine the outcome of Coronary Endarterectomy (CE) in patients undergoing Coronary Artery Bypass Graft (CABG) surgery for diffuse Coronary Artery Disease (CAD), in terms of postoperative mortality and morbidity, relief from angina and survival at one year., Study Design: A case series., Place and Duration of Study: Department of Cardiac Surgery, Armed Forces Institute of Cardiology and National Institute of Heart Diseases, Rawalpindi, from January 2003 to November 2005., Methodology: Included in the study were all patients with such diffuse CAD that conventional bypass grafting was not possible. Those with the diseased coronary artery supplying an akinetic myocardium and a fixed perfusion defect on perfusion scan, or with poor left ventricular function (ejection fraction<30%) in association with severe chronic hepatic disease and deranged liver function tests, permanent severe immune deficiency state, or poor results at lung function tests were excluded. Cardiopulmonary Bypass (CPB) was used in all patients. All patients were followed up for a mean time of one year, for assessment of postoperative mortality and morbidity, relief from angina and survival., Results: Fifty five patients (3.2%) underwent CE of at least one major coronary artery for severe diffuse atheromatous disease. The mean age was 53.9+/-9.5 years. Twenty six (47.3%) had previous Myocardial Infarction (MI), 16 (29.1%) had unstable angina, 12 (21.8%) had poor Left Ventricular (LV) function, 5 (9.1%) underwent emergency CABG surgery for impending infarction, 39 (70.9%) had angina Canadian Cardiovascular Society (CCS) class II/III, 11 (20%) had critical left main stem disease and 12 (21.8%) required Intra-Aortic Balloon Pump (IABP) for hemodynamic support. There were 2 (3.6%) early deaths and 2 (3.6%) cases of non-fatal infarctions. Three (5.4%) patients had low Cardiac Output (CO) after operation. At one year follow-up, there were no late deaths and 43 patients (91.5% of those reporting for follow-up) did not have angina., Conclusion: CE acted as an adjunct to CABG surgery with acceptable operative risks and satisfactory results at one year in terms of mortality and angina relief.

Background: To evaluate the surgical and medical efficacy of the patients operated for Ventricular Septal Defect (VSD) with Pulmonary Hypertension and Pulmonary Vascular Resistance (PVR). Infants and children with elevated PVR and Pulmonary Hypertension are associated with significant mortality and morbidity after surgical closure. Circulatory assist devices and sophisticated medicines may not be available to help in the management of infants and children with elevated Pulmonary artery pressure and resistance. We left Patent Foramen Ovale (PFO) or made atrial communication to decrease the morbidity and mortality associated with the closure of large VSD in this risky group., Methods: Sixteen infants and children were operated with median age of 12 months, operated by the same surgeon (IU), from January' 2004 to December' 2005. They were with large VSD of elevated PVR (3.9+0.3) and underwent VSD closure leaving PFO or artificial ASD (5mm). Surgical approach was through right atrium. Post operatively, all the patients were electively ventilated for 36 hours. They were given intravenous dilators (Glyceral Trinitrate + Phentolamine) and oral Sildenafil up to 1 mg /Kg, six hourly. Five cases went into acute pulmonary hypertensive crisis postoperatively, and were rescued by Prostacycline Nebulization., Results: Sixteen patients had VSD as the primary lesion that underwent operation. The overall early mortality was 6.25% (1/16). There have been no late deaths., Conclusion: Closure of large VSD with elevated PVR can be performed, leaving PFO or artificial ASD, with acceptable mortality and morbidity.

Objective: To identify the factors affecting the outcome, measured in terms of morbidity and mortality, after primary ventricular septal defect (VSD) closure., Design: Descriptive study., Place and Duration of Study: Armed Forces Institute of Cardiology/National Institute of Heart Diseases, Rawalpindi, from January 2002 to October 2003., Subjects and Methods: Children upto the age of 5 years who had primary VSD closure were studied. Patients were divided into two groups. Group-I included survivors and group-II included non-survivors. There was no difference in the conduct of operation among the two groups., Results: A total of 53 patients were operated of whom 47 survived. Pulmonary hypertensive crisis (p < 0.001), pulmonary infections (p < 0.001) and pleural effusions (p < 0.003) were higher in non-survivor group. Patients in non survivor group were younger (0.75 + 0.34 years vs 2.24 + 1.16 years, p = 0.01) having less body weight (4.91 + 1.56 kg vs 7.94 + 3.35, p = 0.03) and high pulmonary artery to systemic pressure ratio at the time of coming off bypass (0.63 + 0.13 vs 0.43 + 0.09, p < 0.001). Non survivors had higher association (66.6 % vs 19.1%) of additional left to right shunts (p < 0.001)., Conclusion: Body weight less than 5 kg along with young age, high pulmonary artery to systemic pressure ratio at the time of coming off bypass and presence of additional left to right shunt are risk factors for adverse outcome.