Towards a benchmarking tool for minimizing wastewater utility greenhouse gas footprints

A benchmark simulation model, which includes a wastewater treatment plant (WWTP)-wide model and a rising main sewer model, is proposed for testing mitigation strategies to reduce the system's greenhouse gas (GHG) emissions. The sewer model was run to predict methane emissions, and its output was used as the WWTP model input. An activated sludge model for GHG (ASMG) was used to describe nitrous oxide (N(2)O) generation and release in activated sludge process. N(2)O production through both heterotrophic and autotrophic pathways was included. Other GHG emissions were estimated using empirical relationships. Different scenarios were evaluated comparing GHG emissions, effluent quality and energy consumption. Aeration control played a clear role in N(2)O emissions, through concentrations and distributions of dissolved oxygen (DO) along the length of the bioreactor. The average value of N(2)O emission under dynamic influent cannot be simulated by a steady-state model subjected to a similar influent quality, stressing the importance of dynamic simulation and control. As the GHG models have yet to be validated, these results carry a degree of uncertainty; however, they fulfilled the objective of this study, i.e. to demonstrate the potential of a dynamic system-wide modelling and benchmarking approach for balancing water quality, operational costs and GHG emissions.

Enhancing aerobic granulation for biological nutrient removal from domestic wastewater

This study focuses on the enhancement of aerobic granulation and biological nutrient removal maintenance treating domestic wastewater. Two sequencing batch reactors (SBRs) were inoculated with either only floccular sludge (100%-floc SBR) or supplemented with 10% crushed granules (90%-floc SBR). Granules developed in both reactors. The 100%-floc SBR achieved 75% of nitrogen and 93% of phosphorus removal at the end of the performance, but some floccular sludge remained in the system. The 90%-floc SBR became fully granulated and finished with 84% and 99% of nitrogen and phosphorus removal, respectively. Regarding biological phosphorus removal, nitrite was identified as an inhibitor of the process. Nitrite levels lower than 5 mg N-NO2-L(-1) were used for anoxic phosphate uptake while higher concentrations inhibited the process.

Molecular level dynamics of genetic oscillator--the effect of protein-protein interaction

Uncovering how interactions of a set of molecular components influence the system's dynamic behavior is important for understanding intracellular processes and elucidating design principles, but unfortunately, there are limited efforts for studying this issue. Here, we study the effect of distinct post-translational dynamics controlled by protein dimerization on oscillations in the repressilator. For this, we propose three biologically motivated model scenarios of the repressilator with monomer or dimer being the active form of repressor, and with protein-protein interactions. It is found that the dimer dissociation constant can tune oscillatory regions, frequency and amplitude. Introducing a modified linear noise approximation to evaluate fluctuations of amplitude and period in the oscillatory systems, we show that different dimerization leads to a different effect on period and amplitude in reducing noise. The manipulation of the circuit's biochemical properties provides a practical strategy for designing a robust and tunable oscillator.

A novel p53-based strategy for protection of gastrointestinal track and bone marrow (BM) from 5-fluorouracil (5-FU)

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Background: Acute toxicity from DNA damaging agents such as radiation and chemotherapy is mainly mediated by p53 which, upon activation, induces massive apoptotic cell death in sensitive tissues such as GI track and BM. Expanding from our recent finding that low-dose arsenic can temporarily and reversibly suppress p53 activation and subsequent tissue damages in normal tissues but not in carcinomas due to distinct differences in p53 status, we used a mouse tumor xenograft model to test the potential of arsenic in protecting the GI track and BM from one of the most commonly used chemotherapeutic agents for GI malignancies, 5-FU, without compromising tumor control.

Methods: Arsenic pretreatment was done by feeding sex-matched mice (4-6 weeks old) with water with or without 1.0 mg/L sodium arsenic for 3 days. Mice were randomized into 4 groups: A. control; B. arsenic only; C. 5-FU (30 mg/kg body weight i.v. for 5 days) only; D. arsenic and 5-FU. 5- FU-induced GI track and BM damages were analyzed histologically with H&E staining 4 weeks after last treatment. Body weight was monitored as a measure of toxicity. Lung carcinoma NCI-H358 was used to generate a mouse xenograft model. Treatments were initiated 3 weeks after implantation when the lung carcinomas reached an average volume of 100 mm3. Tumor volumes were measured periodically. Two independent experiments were done with10 mice per group.

Results: Tumor sizes at 9 weeks were (mean±SE in mm3): 528.1±62.81, 504.04±55.19, 133.02±35.74, 114.47±17.49 for groups A,B,C and D respectively (p=ns, C vs. D). The corresponding body weights were (in gm): 34.6±1.5, 36.4±2.1, 31±1.2, and 35.4±1.8 (p=0.0001, t-test, C vs D). 5-FU treatment was associated with severe damages to small intestine and BM, and such damages were significantly reduced by low-dose arsenic pretreatment by histological examination.

Conclusions: Our data demonstrate that a brief treatment with low-dose arsenic is associated with a marked protection of GI track and BM without compromising the ability of 5-FU to kill carcinoma cells.Our data have provided proof-of- principle for the use of low-dose arsenic to protect GI track and BM from toxicity of 5-FU, and for potential 5-FU dose intensification in clinical settings.

No significant financial relationships to disclose.

Simultaneous determination of lincomycin and spectinomycin residues in animal tissues by gas chromatography-nitrogen phosphorus detection and gas chromatography-mass spectrometry with accelerated solvent extraction

A new multi-dimensional analytical method using gas chromatography-nitrogen phosphorus detection (GC-NPD) and gas chromatography-mass spectrometry (GC-MS) was developed for qualitative and quantitative measurement of lincomycin and spectinomycin residues in food animal tissues. This method is based on a new extraction procedure using accelerated solvent extraction (ASE). The analytes were extracted by phosphate buffer with trichloroacetic acid deproteinization and clean-up by C₁₈ solid-phase extraction (SPE) adding dodecanesulfonic acid sodium salt as an ion-pair reagent. The eluted fraction was evaporated and derivatised with N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) for GC-NPD analysis and GC-MS confirmation. Parameters for extraction pressure, temperature and cycle of ASE, clean-up, derivatisation and analysis procedure were optimised. The method was validated in muscle, kidney and liver of swine, bovine with a low concentration (limit of quantification) of 16.4 and 21.4 µg kg⁻¹ for these two analytes using GC-NPD. For GC-MS, the limits of quantification were 4.1 and 5.6 µg kg⁻¹, respectively. Spiked recoveries from levels of 20 to 200 µg kg⁻¹ were found to be between 73% and 99% with a relative standard deviation (RSD) of less than 17% in GC-NPD. For GC-MS, levels from 5 to 20 µg kg⁻¹ had between 70% and 93% with an RSD of less than 21%. This rapid and reliable method can be used for the characterisation and quantification of residues of lincomycin and spectinomycin in animal tissues.

Pioglitazone modulates the balance of effector and regulatory T cells in apolipoprotein E deficient mice

BACKGROUND AND AIMS

Pioglitazone (PIO) affects T cell-mediated immunity through actions of peroxisome proliferator activated receptor γ (PPARγ). Effector and regulatory T cells control the development of atherosclerosis, a chronic inflammatory disease affecting the arterial blood vessels. The aim of this study was to examine whether PIO ameliorates atherosclerosis by altering the balance of effector and regulatory T cells.

METHODS AND RESULTS

To explore the effect of PIO on early and advanced atherosclerosis, apolipoprotein E deficient (ApoE-/-) mice were fed western diet and received PIO (20 mg/kg/day) by gastric gavage at 6 or 14 weeks of age, respectively for 8 weeks. Data showed PIO markedly inhibited early fatty streak formation. Further, although the advanced fibrofatty plaque sizes were not significantly reduced, the numbers of smooth muscle cells within lesions were increased and higher collagen concentrations were produced. In general, macrophage expression in lesions was decreased. Additionally, the expression of Foxp3(+) cells was increased in lesions and spleens in mice at all PIO treatment stages, whereas the CD4(+)IFN-γ(+)/CD4(+)IL-4(+) cell ratios were reduced.

CONCLUSION

PIO inhibited early atherosclerotic lesion formation and increased the stability of advanced atherosclerotic plaques in ApoE-/- mice, which was associated with altering the balance of effector and regulatory T cells.

Could nitrite/free nitrous acid favour GAOs over PAOs in enhanced biological phosphorus removal systems?

Enhanced biological phosphorus removal (EBPR) normally occurs together with nitrogen removal in wastewater treatment plants (WWTPs). In recent years, efforts have been devoted to remove nitrogen via the nitrite pathway (oxidation of ammonia to nitrite and reduction of nitrite to nitrogen gas without going through nitrate), reducing the requirement for carbon and oxygen in the plant. However nitrite and free nitrous acid (FNA), the protonated species of nitrite, have been shown to cause EBPR deterioration under certain concentrations. This study provides a direct comparison between the different levels of FNA inhibition in the aerobic processes of polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) by reviewing the studies published in this area. Also, new data is presented assessing the FNA effect on the anaerobic metabolism of these two groups of bacteria. Overall, FNA has shown inhibitory effects on most of the processes involved in the metabolism of PAOs and GAOs. However, the inhibition-initiation levels are different between different processes and, even more importantly between the two groups. In general, PAOs appear to be more affected than GAOs at the same level of FNA, thus giving GAOs competitive advantage over PAOs in EBPR systems when nitrite is present.

Abstract P5-05-11: The Cellular Impact of HuR (Human (Hu) Antigen R) in Breast Cancer Cells on the Growth and Invasion In Vitro and the Expression of Cyclin D1 and MMP-9

Introduction: HuR, a ubiquitously expressed member of the Hu family, selectively binds and stabilizes ARE-containing mRNAs encoding proto-oncogenes, cell cycle regulators, cytokines and growth factors. The role of HuR and its cellular function in breast cancer remains unclear. In the present study, we aimed to provide new insights into the molecular and cellular implication of HuR in breast cancer.

Materials and methods. We first constructed a set of anti-HuR ribozyme transgenes that targeted human HuR. Breast cancer cells were transfected with the transgene, in order to establish new sublines with HuR expression knocked down. Cell growth and invasiveness were investigated using in vitro cell models. The expression of cyclin-D1 and MMP2 were determined using immunocytochemistry, Western blotting and polymerase chain reaction.

Results: Here, we show that MCF7 and MDA-MB-231 cells breast cancer cells stability transfected with a hammerhead ribozyme transgene specifically targeted to HuR (MCF7HuRKO and MDA-MB-231HuRKO) have a reduction in HuR expression both at mRNA and protein levels. Using these new sublines of breast cancer cells, the in vitro growth was evaluated. We showed that that HuR knockdown dramatically reduced cell growth in MCF7 cells (P < 0.001) and to a lesser degree reduced that in MDA MB 231 cells. We further demonstrated that reduction of HuR in MDA MB 231 cells (MDA-MB-231HuRKO) resulted in a significant reduction of the in vitro invasiveness in MDA-MB-231 cells (P < 0.001), although the same failed to occur to MCF-7 cells. Furthermore, we found that the decreased cell growth rate in MCF7 cells following HuR knockdown was seen together with a reduction in cyclin D1 transcript and protein levels. It was also interest to observe that the change in invasiveness in MDA-MB-231 cells after HuR knockdown was accompanied by a decrease in MMP-9 levels.

Conclusion: Our study shows that targeting HuR can influences breast cancer cell growth and invasion and suggests a role for HuR in vitro in enhancing breast cancer cell growth and invasion. These changes may be facilitated through changes in the level of cyclin D1 and MMP-9.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-05-11.

Phase I and pharmacological study of the broad-spectrum tyrosine kinase inhibitor JNJ-26483327 in patients with advanced solid tumours

Background:

JNJ-26483327 is an oral, potent, multi-targeted tyrosine kinase inhibitor, inhibiting kinases of epidermal growth factor receptor (EGFR)-1, -2 and -4, rearranged during transfection (RET) receptor, vascular endothelial growth factor receptor (VEGFR)-3 and Src family (Lyn, Fyn, Yes) at low nanomolar concentrations. This phase I, accelerated titration study assessed maximum tolerated dose, safety, pharmacokinetics and pharmacodynamic effects of JNJ-26483327.

Methods:

Nineteen patients with advanced cancers received JNJ-26483327 continuous twice daily (BID) in escalating dose cohorts ranging from 100 to 2100 mg. Pharmacodynamic effects were assessed in paired skin biopsies and blood.

Results:

JNJ-26483327 was well tolerated in doses up to 1500 mg BID, with target-inhibition-related toxicity such as diarrhoea and skin rash, and other common reported toxicities being nausea, vomiting, anorexia and fatigue. At 2100 mg, two episodes of dose-limiting toxicity were observed, consisting of grade 3 anorexia and a combination of grade 3 anorexia and fatigue, respectively. Pharmacokinetics were dose proportional up to 1500 mg in which plasma levels were obtained showing anti-tumour activity in xenograft mouse models. Pharmacodynamic analysis did not show a substantial effect on expression of Ki-67, p27^kip1, phosphorylated mitogen-activated protein kinase, phosphorylated Akt and EGFR, and serum levels of sVEGFR-2, VEGF-C and VEGF-D remained unchanged. Stable disease was noted in six patients (32%).

Conclusion:

JNJ-26483327 is well tolerated and shows a predictable pharmacokinetic profile; the recommended dose for further studies is 1500 mg BID.

The regulation of muscle glycogen: the granule and its proteins

Despite decades of studying muscle glycogen in many metabolic situations, surprisingly little is known regarding its regulation. Glycogen is a dynamic and vital metabolic fuel that has very limited energetic capacity. Thus its regulation is highly complex and multifaceted. The stores in muscle are not homogeneous and there appear to be various metabolic pools. Each granule is capable of independent regulation and fundamental aspects of the regulation appear to be associated with a complex set of proteins (some are enzymes and others serve scaffolding roles) that associate both with the granule and with each other in a dynamic fashion. The regulation includes altered phosphorylation status and often translocation as well. The understanding of the roles and the regulation of glycogenin, protein phosphatase 1, glycogen targeting proteins, laforin and malin are in their infancy. These various processes appear to be the mechanisms that give the glycogen granule precise, yet dynamic regulation.

Efficient inhibition of B-cell lymphoma xenografts with a novel recombinant fusion protein: anti-CD20Fab-LDM

Lidamycin (LDM) is a new member of enediyne antitumor antibiotics family that can be separated and reconstituted. It consists of a labile active enediyne chromophore (AE) and a noncovalently bound apoprotein (LDP). LDM is now in phase II clinical trials. In this study, we described the antitumor features of a fusion protein of LDM, anti-CD20Fab-LDM, targeted to CD20 expressed by B-lymphoid malignancies. Especially, LDM was prepared by a novel two-step method including DNA recombination and molecular reconstitution. Anti-CD20Fab-LDM exerted potent cytotoxicity against CD20+ B-cell lymphoma cell lines in vitro (IC50: 10-30 pM) and in the Raji xenograft model. Two Raji xenografts were allowed to grow to an initial mass of 80 and 500 mm³, respectively, and then anti-CD20Fab-LDM was administered intravenously with the highest dose of 4 nmol kg⁻¹ . The inhibition rates of tumor growth were 90.1 and 85%, which were saliently superior to those of nontargeted LDM. It is noteworthy that anti-CD20Fab-LDM can inhibit the growth of patient-derived cells, including rituximab-resistant patient-derived cells. Thus, CD20-targeted delivery of LDM is a specific and potent therapeutic strategy for B-lymphoid malignancies. In addition, the two-step approach could serve as a new technology platform for making a series of highly potent engineered antibody-based drugs.

Modelling and simulation revealing mechanisms likely responsible for achieving the nitrite pathway through aeration control

Nitrogen removal via nitrite has recently gained a lot of interest because it results in significant savings in both aeration costs and COD (chemical oxygen demand) requirements for denitrification, when compared to the conventional biological nitrogen removal via nitrate. The effectiveness of two different control strategies to achieve the nitrite pathway in systems with sludge retention has been experimentally demonstrated: (i) control of aerobic phase length, with which aeration is terminated as soon as ammonia is completely oxidised; (ii) operation at low DO setpoints in the aerobic phase. These strategies have been extensively studied in nitrifying reactors and are currently applied in real systems achieving biological carbon, nitrogen and phosphorus removal. In this work, we aim to demonstrate, through modelling and simulation, that the competition between nitrite reducers and nitrite oxidisers for nitrite, rather than kinetic selection plays a major role in NOB washout. Moreover, the results show that the occurrence of simultaneous nitrification and denitrification under "aerobic" conditions is very helpful for the nitrite pathway obtainment and for a more efficient COD utilisation.

Repeated Intrathecal Administration of Ropivacaine Causes Neurotoxicity in Rats

Previous studies suggest that ropivacaine causes the least neurotoxicity among local anaesthetics. Most data derive from a single injection of ropivacaine into the subarachnoid space. The histological changes and behavioural effects of repeated intrathecal administration have yet to be studied. We examined the possible neurotoxicity of multiple doses of intrathecal ropivacaine in rats.

Rats received 0.12 ml/kg body weight ropivacaine in normal saline at concentrations of 0.25%, 0.5%, 0.75% and 1.0% at 90-minute intervals via an implanted intrathecal catheter (ID 0.12 mm, OD 0.35 mm) for 48 hours. At L3, the spinal cord and posterior roots were examined by light and electron microscopy. We performed in situ TUNEL assay to evaluate apoptosis in the spinal cord. Sensory threshold to noxious stimulation along with behavioural change were also studied.

Both 0.75% and 1.0% ropivacaine induced neuronal injury characterised by infiltration of inflammatory cells, vacuolation of myelin sheaths and axons, abnormal morphology of neurons and apoptosis in the spinal cord, mainly in posterior roots and the adjacent posterior white matter. Compared to controls, the percentage of maximum possible effect did not show any significant differences between the rats treated with variable concentrations of ropivacaine or tested with either heat or mechanical stimulation. As expected, the recovery time to normal ambulation was prolonged as the ropivacaine concentration was increased.

Ropivacaine can induce neurotoxicity and trigger apoptosis in a dose-dependent manner after repeated intrathecal administration. Although the clinical safety profile of ropivacaine appears favourable compared with other local anaesthetics, it is possible our findings have clinical significance.

Immobilization of Alcaligenes faecalis penicillin G acylase on epoxy-type supports

Alcaligenes faecalis penicillin G acylase has several desired features over other penicillin G acylases and its use in industry requires immobilization. In this work, two novel supports ZH-EP (epoxy-type) and ZH-HA (epoxy-amino type) were used to immobilize Alcaligenes faecalis penicillin G acylase (AfPGA) with Eupergit C as reference. The saturation of immobilized protein on ZH-EP (269 mg/g, 116 h) and ZH-HA (296 mg/g, 15 h) was obtained more rapidly than Eupergit C (197 mg/g, 260 h). And the activity of immobilized AfPGA on ZH-EP (520 U/g) and ZH-HA (2200 U/g) was higher than that on Eupergit C (310 U/g). The properties of three immobilized enzymes were compared and no obvious difference was observed, which indicated that ZH-EP and ZH-HA were promised in industry.

An improved model averaging scheme for logistic regression

Recently, penalized regression methods have attracted much attention in the statistical literature. In this article, we argue that such methods can be improved for the purposes of prediction by utilizing model averaging ideas. We propose a new algorithm that combines penalized regression with model averaging for improved prediction. We also discuss the issue of model selection versus model averaging and propose a diagnostic based on the notion of generalized degrees of freedom. The proposed methods are studied using both simulated and real data.

Impact of nitrate addition on biofilm properties and activities in rising main sewers

Anaerobic sewer biofilm is a composite of many different microbial populations, including sulfate reducing bacteria (SRB), methanogens and heterotrophic bacteria. Nitrate addition to sewers in an attempt to control hydrogen sulfide concentrations affects the behaviour of these populations, which in turn impacts on wastewater characteristics. Experiments were carried out on a laboratory reactor system simulating a rising main to determine the impact of nitrate addition on the microbial activities of anaerobic sewer biofilm. Nitrate was added to the start of the rising main during sewage pump cycles at a concentration of 30 mg-N L(-1) for over 5 months. While it reduced sulfide levels at the outlet of the system by 66%, nitrate was not toxic or inhibitory to SRB activity and did not affect the dominant SRB populations in the biofilm. Long-term nitrate addition in fact stimulated additional SRB activity in downstream biofilm. Nitrate addition also stimulated the activity of nitrate reducing, sulfide oxidizing bacteria that appeared to be primarily responsible for the prevention of sulfide build up in the wastewater in the presence of nitrate. A short adaptation period of three to four nitrate exposure events (approximately 10 h) was required to stimulate biological sulfide oxidation, beyond which no sulfide accumulation was observed under anoxic conditions. Nitrate addition effectively controlled methane concentrations in the wastewater. The nitrate uptake rate of the biofilm increased with repeated exposure to nitrate, which in turn increased the consumption of biodegradable COD in the wastewater. These results provide a comprehensive understanding of the impact of nitrate addition on wastewater composition and sewer biofilm microbial activities, which will facilitate optimization of nitrate dosing for effective sulfide control in rising main sewers.

A muscle-targeting peptide displayed on AAV2 improves muscle tropism on systemic delivery

Adeno-associated virus (AAV) has become a leading gene transfer vector for striated muscles. However, the AAV vectors also exhibit broad tropisms after systemic delivery. In an attempt to improve muscle tropism, we inserted a 7-amino-acid (ASSLNIA) muscle-targeting peptide (MTP) in the capsids of AAV2 at residue 587 or 588, generating AAV₅₈₇MTP and AAV₅₈₈MTP. In vitro studies showed that both viruses diminished their infectivity on non-muscle cell lines as well as on un-differentiated myoblasts, however, preserved or enhanced their infectivity on differentiated myotubes. AAV₅₈₇MTP, but not AAV₅₈₈MTP, also abolished its heparin-binding capacity and infected myotubes in a heparin-independent manner. Furthermore, in vivo studies by intravenous vector administration in mice showed that AAV₅₈₇MTP enhanced its tropism to various muscles and particularly to the heart (24.3 fold of unmodified AAV2), whereas reduced its tropism to the non-muscle tissues such as the liver, lungs and spleen, etc. This alteration of tissue tropism is not simply due to the loss of heparin-binding, since a mutant AAV2 (AAVHBSMut) containing heparin-binding site mutations lost infectivity on both non-muscle and muscle cells. Furthermore, free MTP peptide, but not the scrambled control peptide, competitively inhibited AAV₅₈₇MTP infection on myotubes. These results suggest that AAV2 could be re-targeted to the striated muscles by a muscle-targeting peptide inserted after residue 587 of the capsids. This proof of principle study showed first evidence of peptide-directed muscle targeting upon systemic administration of AAV vectors.

Impact of pegylated liposomal doxorubicin (PLD) plus docetaxel (D) versus single-agent D on health-related quality of life (HRQOL) of patients with advanced breast cancer (BC) previously treated with neoadjuvant-adjuvant anthracycline

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Background: A randomized, multicenter phase 3 trial of PLD+D showed a significant improvement in the primary endpoint of time to progression (TTP) compared with D alone but with increased Grade 3/4 hand-foot syndrome (HFS: 24% vs. 0%) and mucositis/stomatitis (M/S: 12% vs. 1%) in patients (pts) with advanced breast cancer (BC). (Sparano JA et al. SABCS 2008. #80) This analysis evaluated HRQOL in these pts. Methods: Pts were randomized to D 75 mg/m2 (N=373) or PLD 30 mg/m2 + D 60 mg/m2 (N=378) on Day 1 every 21 days until progression or unacceptable toxicity. HRQOL was assessed using the Functional Assessment of Cancer Therapy - Breast (FACT-B) at baseline and at every cycle during treatment. FACT-B has 4 primary domains: physical, social/family, emotional, and functional, plus a BC-specific subscale. The primary analysis was a t-test comparison of change in the trial outcome index (TOI) from baseline to the last evaluation. TOI combined physical/functional domain scores with BC-specific scores. Other FACT-B endpoints analyzed included FACT-B total score and individual subscales. Also, % pts meeting an established minimally important difference (MID) of HRQOL improvement in TOI was assessed. Results: Median number of cycles was 6 for both arms. TOI was available for 97.9% of all scheduled assessments for both treatment groups. At baseline, mean FACT-B and TOI scores were similar for PLD+D vs D arms (94.2±18.6 vs 95.3±18.7 and 59.7±13.8 vs 60.2±13.4, respectively); other FACT-B domains were also similar. PLD+D vs D arms showed similar mean change from baseline to last evaluation in TOI (-4.6±12.2 vs -6.0±12.4; P=0.13). Other FACT-B subscales showed 1–2 point differences across domains over time. Likewise, % pts reaching MID was similar across arms. Pts in both arms experienced similar FACT-B declines as disease progressed. Conclusions: Despite increased HFS and M/S with PLD+D vs D alone, HRQOL was comparable for both arms.

[Table: see text]

Modelling using rRNA-structured biomass models

Models currently used have been developed to describe the storage response in the activated sludge process. In these models the distribution of the substrate flux between growth and storage is an empirical function. rRNA-structured biomass models are proposed to describe the metabolic status of cells in view of predicting the growth response (dmicro/dt) of cells in activated sludge process. The autocatalytic reaction rate of the synthesis of the PSS component (rRNA) can provide a mechanistic explanation for the growth response and the growth lag phase. The proposed models were able to describe and predict properly the growth response of the biomass in various types of reactor. Such models could be more widely applicable by using intrinsic model parameters. This would be a key improvement for as it would lead to improved models for design.

Cohort differences in the progression of developmental pathways: evidence for period effects on secular trends of violence in males

BACKGROUND

Rates of violence in the USA have fluctuated widely over the past few decades. Theorists have examined period and cohort effects, but there appear to be no studies examining these effects on progression in developmental pathways towards violence.

OBJECTIVE

To assess whether differences in progression among individuals in the Pittsburgh Youth Study are consistent with period or cohort effects.

DESIGN

Multivariate logistic regression was conducted to examine differences between cohorts in the odds of progressing through the developmental pathway towards violence. Adjusted and unadjusted odds ratios (ORs) and corresponding 95% CI are reported.

SETTING

Pittsburgh Pennsylvania, from 1987 to 2000.

SUBJECTS

Two cohorts of male adolescents from the Pittsburgh Youth Study. The youngest cohort (n = 503) was followed from median ages 7 to 20, and the oldest cohort (n = 506) was followed up from median ages 13 to 25.

MAIN OUTCOME MEASURE

The odds of progression along a developmental pathway towards violence.

RESULTS

There was no statistically significant difference between the cohorts in progression from minor aggression to physical fighting (OR = 1.13, 95% CI 0.77 to 1.65). However, after adjustment for major risk factors, the oldest cohort was significantly more likely to progress from physical fighting to violence (OR = 2.34, 95% CI 1.39 to 3.92).

CONCLUSIONS

These results provide initial evidence that cohort effects, which would be present early in development, do not contribute significantly to later differences in reported violence and raises the possibility of whether period effects can explain these differences.

Nitrite effectively inhibits sulfide and methane production in a laboratory scale sewer reactor

The production and emission of hydrogen sulfide and methane by anaerobic microoganisms in sewer systems is a well-documented problem. The effectiveness of nitrite in controlling sulfide and methane production was tested in a laboratory scale sewer reactor. Nitrite was continuously dosed in the reactor for 25 days at concentrations of 20-140mgN/L. No sulfide and methane accumulation was observed in the reactor in the presence of nitrite. A significant reduction was observed in the sulfate reduction and methane production capabilities of the biofilm. Nitrite also stimulated biological sulfide oxidation within the biofilm. The nitrite uptake rate of the reactor increased over the nitrite dosing period and nitrous oxide production was observed within the biofilm. When nitrite addition was stopped, sulfate reduction and methane production gradually resumed, and reached pre-nitrite addition levels after 2.5 months. The slow recovery suggests that nitrite can be applied intermittently for sulfide and methane control, which represents a key advantage over similar chemicals such as nitrate and oxygen. The study demonstrates nitrite addition as a promising and effective strategy for the management of sulfide and methane in sewers. Further investigation and optimization are still required before application in the field.

Torsional ultrasound modality for hard nucleus phacoemulsification cataract extraction

AIM

To evaluate the efficacy and safety of phacoemulsification using torsional modality with different parameter settings for hard nucleus cataract extraction.

DESIGN

A prospective, randomised clinical study.

METHODS

A clinical practice study conducted at the Cataract Service, Zhongshan Ophthalmic Center, Sun-Yat-Sen University, and Guangzhou. One eye each from 198 consecutive patients with cataract density grade IV according to the Emery-Little system classification system, requiring phacoemulsification and intraocular lens implantation, was included. Eyes were randomly assigned to the Linear Torsional combined with Ultrasound power group (Linear Tor+US group, n = 66), 100% Fixed Torsional group (Fixed Tor group, n = 65) and conventional Ultrasound burst group (US group, n = 67). All surgeries were performed by a single experienced surgeon and outcomes evaluated by another surgeon masked to treatment. Intraoperative parameters were Ultrasound Time (UST), Cumulative Dissipated Energy (CDE) and surgical complications. Patients were examined on post-op days 1, 7 and 30. Postoperative outcomes were final best corrected visual acuity (BCVA), average central and incisional corneal thickness and central endothelial cell counts.

RESULTS

The mean UST was lower in the Fixed Tor group than in the US group and in the Lin US+Tor group (p0.01), greater average central corneal and incisional thickness on days 1, 7 (p0.01), and higher average corneal endothelial cell losses on day 7 and 30 days (p

CONCLUSIONS

Torsional combined with ultrasound power or high fixed torsional amplitude can yield more effective hard nucleus phacoemulsification than conventional ultrasound modality.

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MESH Headings

• Aged
• Aged, 80 and over
• Cornea/pathology
• Endothelium, Corneal/pathology
• Female
• Humans
• Lens Nucleus, Crystalline/surgery
• Male
• Middle Aged
• Phacoemulsification/methods
• Prospective Studies
• Tomography, Optical Coherence
• Treatment Outcome
• Ultrasonic Therapy/methods
• Visual Acuity

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A phase I study of the safety and pharmacokinetics of trabectedin in combination with pegylated liposomal doxorubicin in patients with advanced malignancies

BACKGROUND

To determine the maximum tolerated dose (MTD), safety, potential pharmacokinetic (PK) interactions, and effect on liver histology of trabectedin in combination with pegylated liposomal doxorubicin (PLD) for advanced malignancies.

PATIENTS AND METHODS

Entry criteria for the 36 patients included normal liver function, prior doxorubicin exposure <250 mg/m(2), and normal cardiac function. A 1-h PLD (30 mg/m(2)) infusion was followed immediately by one of six trabectedin doses (0.4, 0.6, 0.75, 0.9, 1.1, and 1.3 mg/m(2)) infused over 3 h, repeated every 21 days until evidence of complete response (CR), disease progression, or unacceptable toxicity. Plasma samples were obtained to assess PK profiles.

RESULTS

The MTD of trabectedin was 1.1 mg/m(2). Drug-related grade 3 and 4 toxic effects were neutropenia (31%) and elevated transaminases (31%). Six patients responded (one CR, five partial responses), with an overall response rate of 16.7%, and 14 had stable disease (less than a 50% reduction and less than a 25% increase in the sum of the products of two perpendicular diameters of all measured lesions and the appearance of no new lesions) >4 months (39%). Neither drug had its PK affected significantly by concomitant administration compared with trabectedin and PLD each given as a single agent.

CONCLUSION

Trabectedin combined with PLD is generally well tolerated at therapeutic doses of both drugs in pretreated patients with diverse tumor types and appears to provide clinical benefit. These results support the need for additional studies of this combination in appropriate cancer types.