Bioaugmentation of pilot-scale slow sand filters can achieve compliant levels for the micropollutant metaldehyde in a real water matrix.

Metaldehyde is a polar, mobile, low molecular weight pesticide that is challenging to remove from drinking water with current adsorption-based micropollutant treatment technologies. Alternative strategies to remove this and compounds with similar properties are necessary to ensure an adequate supply of safe and regulation-compliant drinking water. Biological removal of metaldehyde below the 0.1 µg•L-1 regulatory concentration was attained in pilot-scale slow sand filters (SSFs) subject to bioaugmentation with metaldehyde-degrading bacteria. To achieve this, a library of degraders was first screened in bench-scale assays for removal at micropollutant concentrations in progressively more challenging conditions, including a mixed microbial community with multiple carbon sources. The best performing strains, A. calcoaceticus E1 and Sphingobium CMET-H, showed removal rates of 0.0012 µg•h-1•107 cells-1 and 0.019 µg•h-1•107 cells-1 at this scale. These candidates were then used as inocula for bioaugmentation of pilot-scale SSFs. Here, removal of metaldehyde by A. calcoaceticus E1, was insufficient to achieve compliant water regardless testing increasing cell concentrations. Quantification of metaldehyde-degrading genes indicated that aggregation and inadequate distribution of the inoculum in the filters were the likely causes of this outcome. Conversely, bioaugmentation with Sphingobium CMET-H enabled sufficient metaldehyde removal to achieve compliance, with undetectable levels in treated water for at least 14 d (volumetric removal: 0.57 µg•L-1•h-1). Bioaugmentation did not affect the background SSF microbial community, and filter function was maintained throughout the trial. Here it has been shown for the first time that bioaugmentation is an efficient strategy to remove the adsorption-resistant pesticide metaldehyde from a real water matrix in upscaled systems. Swift contaminant removal after inoculum addition and persistent activity are two remarkable attributes of this approach that would allow it to effectively manage peaks in metaldehyde concentrations (due to precipitation or increased application) in incoming raw water by matching them with high enough degrading populations. This study provides an example of how stepwise screening of a diverse collection of degraders can lead to successful bioaugmentation and can be used as a template for other problematic adsorption-resistant compounds in drinking water purification.

Microbial changes linked to the accelerated degradation of the herbicide atrazine in a range of temperate soils.

Accelerated degradation is the increased breakdown of a pesticide upon its repeated application, which has consequences for the environmental fate of pesticides. The herbicide atrazine was repeatedly applied to soils previously untreated with s-triazines for >5 years. A single application of atrazine, at an agriculturally relevant concentration, was sufficient to induce its rapid dissipation. Soils, with a range of physico-chemical properties and agricultural histories, showed similar degradation kinetics, with the half-life of atrazine decreasing from an average of 25 days after the first application to <2 days after the second. A mathematical model was developed to fit the atrazine-degrading kinetics, which incorporated the exponential growth of atrazine-degrading organisms. Despite the similar rates of degradation, the repertoire of atrazine-degrading genes varied between soils. Only a small portion of the bacterial community had the capacity for atrazine degradation. Overall, the microbial community was not significantly affected by atrazine treatment. One soil, characterised by low pH, did not exhibit accelerated degradation, and atrazine-degrading genes were not detected. Neutralisation of this soil restored accelerated degradation and the atrazine-degrading genes became detectable. This illustrates the potential for accelerated degradation to manifest when conditions become favourable. Additionally, the occurrence of accelerated degradation under agriculturally relevant concentrations supports the consideration of the phenomena in environmental risk assessments.

Dynamic loading, matrix maintenance and cell injection therapy of human intervertebral discs cultured in a bioreactor.

Low back pain originating from intervertebral disc (IVD) degeneration affects the quality of life for millions of people, and it is a major contributor to global healthcare costs. Long-term culture of intact IVDs is necessary to develop ex vivo models of human IVD degeneration and repair, where the relationship between mechanobiology, disc matrix composition and metabolism can be better understood. A bioreactor was developed that facilitates culture of intact human IVDs in a controlled, dynamically loaded environment. Tissue integrity and cell viability was evaluated under 3 different loading conditions: low 0.1-0.3, medium 0.1-0.3 and high 0.1-1.2 MPa. Cell viability was maintained > 80 % throughout the disc at low and medium loads, whereas it dropped to approximately 70 % (NP) and 50 % (AF) under high loads. Although cell viability was affected at high loads, there was no evidence of sGAG loss, changes in newly synthesised collagen type II or chondroadherin fragmentation. Sulphated GAG content remained at a stable level of approximately 50 µg sGAG/mg tissue in all loading protocols. To evaluate the feasibility of tissue repair strategies with cell supplementation, human NP cells were transplanted into discs within a thermoreversible hyaluronan hydrogel. The discs were loaded under medium loads, and the injected cells remained largely localised to the NP region. This study demonstrates the feasibility of culturing human IVDs for 14 days under cyclic dynamic loading conditions. The system allows the determination a safe range-of-loading and presents a platform to evaluate cell therapies and help to elucidate the effect of load following cell-based therapies.

Selective internal radiation therapy for liver malignancies.

BACKGROUND: Selective internal radiation therapy (SIRT) is a non-ablative technique for the treatment of liver primaries and metastases, with the intention of reducing tumour bulk. This study aimed to determine optimal patient selection, and elucidate its role as a downsizing modality. METHODS: Data were collected retrospectively on patients who underwent SIRT between 2011 and 2014. The procedure was performed percutaneously by an expert radiologist. Response was analysed in two categories, based on radiological (CT/MRI according to Response Evaluation Criteria In Solid Tumours (RECIST)) and biological (α-fetoprotein, carcinoembryonic antigen, carbohydrate antigen 19-9, chromogranin A) parameters. RESULTS: Forty-four patients were included. Liver metastases from colorectal cancer (22 patients) and hepatocellular carcinoma (HCC) (9) were the most common pathologies. Radiological response data were collected from 31 patients. A reduction in sum of diameters (SOD) was observed in patients with HCC (median -24.1 (95 per cent c.i. -43.4 to -3.8) per cent) and neuroendocrine tumours (-30.0 (-45.6 to -7.7) per cent), whereas a slight increase in SOD was seen in patients with colorectal cancer (4.9 (-10.6 to 55.3) per cent). Biological response was assessed in 17 patients, with a reduction in 12, a mixed response in two and no improvement in three. Six- and 12-month overall survival rates were 71 and 41 per cent respectively. There was no difference in overall survival between the RECIST response groups (median survival 375, 290 and 214 days for patients with a partial response, stable disease and progressive disease respectively; P = 0.130), or according to primary pathology (P = 0.063). Seven patients underwent liver resection with variable responses after SIRT. CONCLUSION: SIRT may be used to downsize tumours and may be used as a bridge to surgery in patients with tumours deemed borderline for resection.

Systematic review of irreversible electroporation in the treatment of advanced pancreatic cancer.

BACKGROUND: Irreversible electroporation (IRE) is a novel procedure to combat pancreatic cancer, whereby high voltage pulses are delivered, resulting in cell death. This represents an ideal alternative to other thermal treatment modalities, as there is no overriding heat effect, therefore reducing the risk of injury to vessels and ducts. METHODS: Multiple databases were searched to January 2014. Primary outcome measures were survival and associated morbidity. 41 articles were initially identified; of these 4 studies met the inclusion criteria, yielding 74 patients in total. RESULTS: 94.5% of patients had locally advanced tumours, the remainder had metastatic disease. Treated tumour size ranged from 1 to 7 cm. IRE approach included open (70.3%), laparoscopic (2.7%) and percutaneous (27%; ultrasound-guided 30%, CT-guided 70%) Morbidity ranged from 0 to 33%; due to the high number of simultaneous procedures performed (resection/bypass) it was difficult to ascertain IRE-related complications. However no significant bleeding occurred when IRE-alone was performed. Survival statistics suggest a prognostic benefit. Reported survival included: 6 month survival of 40% (n = 5) and 70% (n = 14); PFS and OS 14 and 20 months respectively (n = 54). Results of most interest showed a significant survival benefit in matched IRE vs non-IRE groups (PFS 14 vs 6 mths; p = 0.01, OS 20 vs 11 mths; p = 0.03). CONCLUSION: Initial evidence suggests IRE incurs a prognostic benefit with minimal morbidity. More high quality research is required to determine the role IRE may play in the multi-modal management of pancreatic cancers.

The novel use of a biodegradable stent placed by percutaneous transhepatic cholangiography for the treatment of a hepaticojejunostomy biliary leak following an extended left hepatectomy and pancreaticoduodenectomy.

A 61-year-old man presented with jaundice, and subsequently underwent an extended left hepatectomy and pancreaticoduodenectomy for a cholangiocarcinoma invading the head of the pancreas. The patient developed sepsis due to a biliary leak at the hepaticojejunostomy. We describe the original use of a biodegradable stent, deployed via percutaneous transhepatic cholangiography into the Roux limb, resulting in good drainage and resolution of sepsis. The chief benefit of this procedure is the lack of need for subsequent removal as well as purported reduced biofilm accumulation. We believe this to be the first reported case of this type and the literature surrounding the subject is also discussed.

Incidence of complex regional pain syndrome after foot and ankle surgery.

Complex regional pain syndrome (CRPS) is an uncommon complication of orthopedic surgery, and few investigators have considered the incidence in foot and ankle surgery. In the present retrospective cohort study of 390 patients who had undergone elective foot and/or ankle surgery in our department from January to December 2009, the incidence of postoperative CRPS was calculated and explanatory variables were analyzed. A total of 17 patients (4.36%) were identified as meeting the International Association for the Study of Pain criteria for the diagnosis of CRPS. Of the 17 patients with CRPS, the mean age was 47.2 ± 9.7 years, and 14 (82.35%) were female. All the operations were elective, and 9 (52.94%) involved the forefoot, 3 (17.65%) the hindfoot, 3 (17.65%) the ankle, and 2 (11.76%) the midfoot. Twelve patients (70.59%) had new-onset CRPS after a primary procedure, and 5 (29.41%) had developed CRPS after multiple surgeries. Three patients (17.65%) had documented nerve damage intraoperatively and thus developed new-onset CRPS type 2. Blood test results were available for 14 patients (82.35%) at a minimum of 3 months postoperatively, and none had elevated inflammatory markers. Five of the patients (29.41%) were smokers, and 8 (47.06%) had had a pre-existing diagnosis of anxiety and/or depression. From our findings, we recommend that middle-age females and those with a history of anxiety or depression, who will undergo elective foot surgery, should be counseled regarding the risk of developing CRPS during the consent process. We recommend similar studies be undertaken in other orthopedic units, and we currently are collecting data from other orthopedic departments within Scotland.

A randomized controlled trial of fallopian tube sperm perfusion compared with standard intrauterine insemination for women with non-tubal infertility.

STUDY QUESTION: Does fallopian tube sperm perfusion (FSP) result in better pregnancy and live birth rates than standard intrauterine insemination (SIUI) for couples with non-tubal infertility with or without gonadotrophin or clomiphene stimulation? SUMMARY ANSWER: There was no evidence of an improvement in live birth rates with FSP compared with SIUI. WHAT IS KNOWN ALREADY: Previous randomized controlled trials have suggested improved live birth rates with FSP but these trials were small. A systematic review published in 2004 suggested heterogeneity in results. STUDY DESIGN, SIZE, AND DURATION: This pragmatic, multicentre, randomized controlled trial compared SIUI and FSP in 417 women with non-tubal infertility. PARTICIPANTS/MATERIALS, SETTING, METHODS: The patients were treated at fertility clinics in New Zealand, Australia and the United Arab Emirates. MAIN RESULTS AND THE ROLE OF CHANCE: Four hundred and seventeen women were randomized to SIUI (n = 210) or FSP (n = 207). Data were available for analysis from 198 women in the SIUI group and 198 women in the FSP group. There were 19 women with incomplete data because of cycle cancellation or withdrawals and 2 women who conceived prior to commencing treatment. There were no significant differences in live birth rates between the two groups with 27 (12.9%) in the SIUI group and 21 in the FSP group (10.1%) [Odds Ratio (OR) 1.31 (0.71, 2.39), P = 0.48]. Two ectopic pregnancies were reported in the SIUI group and one was reported in the FSP group. LIMITATIONS, REASONS FOR CAUTION: Different ovulation protocols were used in the different clinics. Approximately 10% of the cycles involved donor sperm and ∼5% of the cycles did not complete the assigned intervention. WIDER IMPLICATIONS OF THE FINDINGS: There was no evidence of an improvement in live birth rates with FSP compared with SIUI. STUDY FUNDING/COMPETING INTEREST(S): The study was funded in part by the A+ trust of the Auckland District Health Board. No commercial funding was received. TRIAL REGISTRATION NUMBER: ANZCTR Number ACTRN12612001303831.

Posttransplant lymphoproliferative disorder presenting as multiple cystic lesions in a renal transplant recipient.

We report a case of a 67-year-old man who experienced allograft dysfunction following a renal transplantation from a donation after cardiac death. The postoperative course was initially complicated by episodes of E. coli urinary sepsis causing pyrexia and a raised creatinine level. Ultrasound scanning 5 weeks posttransplant revealed mild hydronephrosis with several parenchymal cystic areas measuring up to 2 cm with appearances suggestive of fungal balls. Aspirated fluid again grew Escherichia coli, and this was treated with the appropriate antimicrobial therapy. The patient continued to have episodes of culture-negative sepsis; therefore, a computed tomography scan was performed 6 months posttransplant, which revealed multiple lesions in the renal cortex as well as liver and spleen. Subsequent biopsy revealed an Epstein-Barr virus-driven lymphoproliferation consistent with a polymorphic posttransplantation lymphoproliferative disorder (PTLD). This rare case of PTLD presenting as multiple renal, hepatic and splenic lesions emphasizes the need for a high index of clinical suspicion for this condition. Abnormal para-renal allograft masses should be biopsied to allow swift and effective management of a disease that can disseminate and become significantly more challenging to manage.

Isolated splenic metastasis from renal cell carcinoma: case report and review.

This report presents the case of a 70-year-old woman with a previous history of a left nephrectomy for renal cell carcinoma (RCC), who developed general malaise and fatigue. Abdominal computed tomography demonstrated an enhancing 6 × 7 cm necrotic lesion in the lower pole of the spleen suggestive of a metastasis. Given the highly suspicious nature of the lesion we proceeded to splenectomy. The tumour did not breach the splenic capsule, and there was no local diaphragmatic involvement. The mass was concluded to be a true metastasis of the original RCC rather than local recurrence of the disease. The causes of isolated solid splenic lesions are wide and varied, however a past or present history of malignancy should lead to a high index of suspicion for a splenic metastasis. We report an extremely unusual case of spread from a RCC.

Hepatic Metastasis via a Ventriculo-Peritoneal Shunt from an Intracranial Meningioma: Case Report and Review of the Literature.

Meningiomas are slow-growing intracranial/intraspinal tumours, with a wide range of histopathological variants. The more aggressive atypical and malignant types can disseminate via the venous system, lymphatics or cerebrospinal fluid, with the lungs and pleura being the most common site of extracranial metastasis. We look at a 68-year-old woman presenting with abdominal pain, who had previously been treated for an intracranial meningioma with a ventriculo-peritoneal shunt in situ. Investigation revealed a lesion in segment 4 of the liver with the shunt tip being in close proximity. Biopsy was consistent with metastatic meningioma. A liver resection was subsequently performed. We postulate that this is the first reported case of dissemination of an intracranial meningioma via cerebrospinal fluid by means of a ventriculo-peritoneal shunt.

Organization of the respiratory chain of Neisseria meningitidis.

The ability of Neisseria meningitidis to utilize both oxygen and nitrogen oxides as respiratory substrates allows it to thrive in the diverse environment of the human host. Genome analysis highlighted genes encoding a cbb(3) cytochrome oxidase, the aniA nitrite reductase gene and the norB nitric oxide reductase gene. In the present study, we used myxothiazol as an inhibitor of the bc(1) complex in intact cells and demonstrated that electron flow to nitrite reductase and the cytochrome oxidase, but not NO reductase, passes via the cytochrome bc(1) complex. UV-visible spectrophotometry of intact cells demonstrated that oxygen oxidizes c-type and b-type cytochromes. Oxidation of cytochromes by nitrite was only seen in microaerobically precultured whole cells, and the predominant oxidizable cytochromes were b-type. These are likely to be associated with the oxidation of a b-haem-containing nitric oxide reductase. Nitrite inhibits the oxidation of cytochromes by oxygen in a nitrite reductase-independent manner, indicating that nitrite may inhibit oxidase activity directly, as well as via the intermediate of denitrification, nitric oxide.

Effect of combined oxidative and nitrosative stress on Neisseria meningitidis.

Reactive oxygen and nitrogen species are produced by the human immune system in response to infection. Methods to detoxify these reactive species are vital to the survival of human pathogens, such as Neisseria meningitidis, which is the major aetiological agent of bacterial meningitis. Following activation, macrophages produce superoxide (O(2)(-)), hydrogen peroxide (H(2)O(2)) and nitric oxide (NO). The toxicity of O(2)(-), generated using X/Xo (xanthine/xanthine oxidase), and H(2)O(2) was investigated in the presence and absence of the NO donor DEA-NONOate [2-(N,N-diethylamino)-diazenolate-2-oxide diethylammonium salt]. Most of the toxicity from X/Xo was due to H(2)O(2). In N. meningitidis, NO decreased the toxicity of the H(2)O(2). In contrast, in the enteric bacterium Escherichia coli, NO increased the toxicity of the H(2)O(2).

Microaerobic denitrification in Neisseria meningitidis.

The major aetiological agent of human bacterial meningitis is Neisseria meningitidis. During the course of disease and host colonization, the bacterium has to withstand limited oxygen availability. Nitrogen oxide and nitrogen oxyanions are thought to be present, which may constitute an alternative sink for electrons from the N. meningitidis respiratory chain. A partial denitrification pathway is encoded by the aniA nitrite reductase gene and the norB nitric oxide reductase gene. Analysis of the completed genome sequences of two N. meningitidis strains is used to generate a model for the membrane-associated respiratory chain of this organism. Analysis of aniA expression indicates it to be controlled primarily by oxygen and secondarily by nitrite. The ability of N. meningitidis to denitrify relies on microaerobic growth conditions. Here we show that under microaerobic conditions nitrite supplements oxygen as an alternative respiratory substrate.

Purification and characterization of cytochrome c' from Neisseria meningitidis.

Cytochrome c', a c-type cytochrome with unique spectroscopic and magnetic properties, has been characterized in a variety of denitrifying and photosynthetic bacteria. Cytochrome c' has a role in defence and/or removal of NO but the mechanism of action is not clear. To examine the function of cytochrome c' from Neisseria meningitidis, the protein was purified after heterologous overexpression in Escherichia coli. The electronic spectra of the oxidized c' demonstrated a pH-dependent transition (over the pH range of 6-10) typical of known c'-type cytochromes. Interestingly, the form in which NO is supplied determines the redox state of the resultant haem-nitrosyl complex. Fe(III)-NO complexes were formed when Fe(II) or Fe(III) cytochrome c' was sparged with NO gas, whereas an Fe(II)-NO complex was generated when NO was supplied using DEA NONOate (diazeniumdiolate).

Maximal expression of membrane-bound nitrate reductase in Paracoccus is induced by nitrate via a third FNR-like regulator named NarR.

Respiratory reduction of nitrate to nitrite is the first key step in the denitrification process that leads to nitrate loss from soils. In Paracoccus pantotrophus, the enzyme system that catalyzes this reaction is encoded by the narKGHJI gene cluster. Expression of this cluster is maximal under anaerobic conditions in the presence of nitrate. Upstream from narK is narR, a gene encoding a member of the FNR family of transcriptional activators. narR is transcribed divergently from the other nar genes. Mutational analysis reveals that NarR is required for maximal expression of the membrane-bound nitrate reductase genes and narK but has no other regulatory function related to denitrification. NarR is shown to require nitrate and/or nitrite is order to activate gene expression. The N-terminal region of the protein lacks the cysteine residues that are required for formation of an oxygen-sensitive iron-sulfur cluster in some other members of the FNR family. Also, NarR lacks a crucial residue involved in interactions of this family of regulators with the sigma(70) subunit of RNA polymerase, indicating that a different mechanism is used to promote transcription. narR is also found in Paracoccus denitrificans, indicating that this species contains at least three FNR homologues.

Nitrate and nitrite transport in bacteria.

The topological arrangements of nitrate and nitrite reductases in bacteria necessitate the synthesis of transporter proteins that carry the nitrogen oxyanions across the cytoplasmic membrane. For assimilation of nitrate (and nitrite) there are two types of uptake system known: ABC transporters that are driven by ATP hydrolysis, and secondary transporters reliant on a proton motive force. Proteins homologous to the latter type of transporter are also involved in nitrate and nitrite transport in dissimilatory processes such as denitrification. These proteins belong to the NarK family, which is a branch of the Major Facilitator Superfamily. The mechanism and substrate specificity of transport via these proteins is unknown, but is discussed in the light of sequence analysis of members of the NarK family. A hypothesis for nitrate and nitrite transport is proposed based on the finding that there are two distinct types of NarK.

Enzymatic removal of nitric oxide catalyzed by cytochrome c' in Rhodobacter capsulatus.

Cytochrome c' from Rhodobacter capsulatus has been shown to confer resistance to nitric oxide (NO). In this study, we demonstrated that the amount of cytochrome c' synthesized for buffering of NO is insufficient to account for the resistance to NO but that the cytochrome-dependent resistance mechanism involves the catalytic breakdown of NO, under aerobic and anaerobic conditions. Even under aerobic conditions, the NO removal is independent of molecular oxygen, suggesting cytochrome c' is a NO reductase. Indeed, we have measured the product of NO breakdown to be nitrous oxide (N(2)O), thus showing that cytochrome c' is behaving as a NO reductase. The increased resistance to NO conferred by cytochrome c' is distinct from the NO reductase pathway that is involved in denitrification. Cytochrome c' is not required for denitrification, but it has a role in the removal of externally supplied NO. Cytochrome c' synthesis occurs aerobically and anaerobically but is partly repressed under denitrifying growth conditions when other NO removal systems are operative. The inhibition of respiratory oxidase activity of R. capsulatus by NO suggests that one role for cytochrome c' is to maintain oxidase activity when both NO and O(2) are present.

Enantioselective deprotonation reactions using polymer-supported chiral magnesium amide bases.

Novel and readily accessible polymer-supported chiral magnesium amide reagents have been prepared and shown to be effective in the asymmetric deprotonation of a series of prochiral cyclohexanones, affording good to excellent levels of both conversion and enantiomeric ratio (up to 93:7); the Merrifield-based chiral amine species has been shown to be readily recyclable.