Modelling clogging and biofilm detachment in sponge carrier media

Sponge carrier media provide a large surface area for biofilm support; however, little information is known about how to model their dual nature as a moving bed and as porous media. To investigate the interaction of mass transfer and detachment with bio-clogging, a novel biofilm model framework was built based on individual-based modelling, and hydrodynamics were modelled using the lattice Boltzmann method. The combined model structure enabled the simulation of oxygen and biomass distribution inside the porous network as well as inside the biofilm. In order to apply the model to moving bed biofilm reactors (MBBR), biofilm detachment due to abrasion (carrier collisions) was modelled to be dependent on intracarrier distance. In the initial growth stage, biofilm grew homogeneously on the internal skeleton after which a more discontinuous growth developed which significantly increased permeability. Low detachment rates caused clogging in the outer pores which limited growth of biofilm to the surface region of the sponge. High detachment rates on the surface enabled deeper oxygen penetration with higher internal biomass activity. The degree of clogging was also sensitive to the presence of extracellular polymeric substances because of its large spatial occupancy.

A modified anaerobic digestion process with chemical sludge pre-treatment and its modelling

Activated Sludge Models (ASMs) assume an unbiodegradable organic particulate fraction in the activated sludge, which is derived from the decay of active microorganisms in the sludge and/or introduced from wastewater. In this study, a seasonal change of such activated sludge constituents in a municipal wastewater treatment plant was monitored for 1.5 years. The chemical oxygen demand ratio of the unbiodegradable particulates to the sludge showed a sinusoidal pattern ranging from 40 to 65% along with the change of water temperature in the plant that affected the decay rate. The biogas production in a laboratory-scale anaerobic digestion (AD) process was also affected by the unbiodegradable fraction in the activated sludge fed. Based on the results a chemical pre-treatment using H2O2 was conducted on the digestate to convert the unbiodegradable fraction to a biodegradable one. Once the pre-treated digestate was returned to the digester, the methane conversion increased up to 80% which was about 2.4 times as much as that of the conventional AD process, whilst 96% of volatile solids in the activated sludge was digested. From the experiment, the additional route of the organic conversion processes for the inert fraction at the pre-treatment stage was modelled on the ASM platform with reasonable simulation accuracy.

Eastern Canadian Colorectal Cancer Consensus Conference: standards of care for the treatment of patients with rectal, pancreatic, and gastrointestinal stromal tumours and pancreatic neuroendocrine tumours

The annual Eastern Canadian Colorectal Cancer Consensus Conference was held in Halifax, Nova Scotia, October 20-22, 2011. Health care professionals involved in the care of patients with colorectal cancer participated in presentation and discussion sessions for the purposes of developing the recommendations presented here. This consensus statement addresses current issues in the management of rectal cancer, including pathology reporting, neoadjuvant systemic and radiation therapy, surgical techniques, and palliative care of rectal cancer patients. Other topics discussed include multidisciplinary cancer conferences, treatment of gastrointestinal stromal tumours and pancreatic neuroendocrine tumours, the use of folfirinox in pancreatic cancer, and treatment of stage ii colon cancer.

Efficacy of sutureless and glue free limbal conjunctival autograft for primary pterygium surgery

INTRODUCTION

There are numerous adjunctive measures described to reduce the recurrence rates after pterygium excision.

OBJECTIVE

To study the efficacy and complications of sutureless and glue free limbal conjunctival autograft for the management of primary pterygium over a period of one year.

MATERIALS AND METHODS

A prospective interventional case series was carried out in 40 consecutive eyes with primary nasal pterygium requiring surgical excision. Pterygium excision with limbal conjunctival autografting without using glue or sutures was performed in all the patients followed by bandaging for 48 hours. The patients were followed up post operatively on 2nd day, 1 week, 6 weeks, 6 months and 12 months. They were examined for haemorrhage, wound gape, graft shrinkage, chemosis, graft dehiscence, recurrence or any other complication.

RESULTS

The mean age of the patients was 42.8 years (range 23-61), 75% of which were males. Total graft dehiscence occurred in 2 eyes (5%), graft retraction in 3 eyes (7.5%) and recurrence was seen in 1 eye (2.5%). At 6 weeks postoperatively, the gain in uncorrected visual acuity ranged from 0.18 to 0.5 log MAR in 7 eyes. No other complication was noted.

CONCLUSIONS

Sutureless and glue free limbal conjunctival autografting following pterygium excision is a safe, effective and economical option for the management of primary pterygium.

Tracer experiment and RTD analysis of DAF separator with bar-type baffles

This paper describes the development of a new dissolved air flotation (DAF) separator with a flow streamlining baffle to improve solid separation efficiency. The analysis of the RTD (residence time distribution) curves indicated that the parameter θ(10) (dimensionless time at which 10% of tracer has discharged) increased from 0.38 for control reactor to 0.54 for the test reactor, suggesting significant reduction in short circuit flow. The RTD curves were also used to develop a compartment model for white water (rich in micro-bubbles and water flow is turbulent) and clear water (little or no air content and water flow is quiescent) zones in the reactor using a series of CSTR (continuous stirred tank reactors) and plug flow regime respectively. The proportion of the volume occupied by the white water zone was different in control and test configurations. In the test reactor, the fraction of the clear water zone was found to increase from 6 to 37%, resulting in improvement of the suspended solid (SS) removal efficiency from 97 to 99%.

A multicentre open-label safety and efficacy study of tetrodotoxin for cancer pain

BACKGROUND

Cancer pain is highly prevalent, and existing treatments are often insufficient to provide adequate relief.

OBJECTIVES

We assessed the long-term safety and efficacy of subcutaneous tetrodotoxin treatment in reducing the intensity of chronic cancer-related pain.

METHODS

In this multicentre open-label longitudinal trial, 30 μg tetrodotoxin was administered subcutaneously twice daily for 4 days in a heterogeneous cohort of patients with persistent pain despite opioids and other analgesics. "Responder" was defined as a mean reduction of 30% or more in pain intensity from baseline; and "clinical responder" as some pain reduction, but less than 30%, plus agreement on the part of both the patient and the physician that a meaningful analgesic response to treatment had occurred.

RESULTS

Of 45 patients who entered the longitudinal trial, 41 had sufficient data for analysis. Of all 45 patients, 21 (47%) met the criteria for "responder" [16 patients (36%)] or "clinical responder" [5 patients (11%)]. Onset of pain relief was typically cumulative over days, and after administration ended, the analgesic effect subsided over the course of a few weeks. No evidence of loss of analgesic effect was observed during subsequent treatments (2526 patient-days in total and a maximum of 400 days in 1 patient). One patient withdrew from the study because of adverse events. Toxicity was usually mild (82%) or moderate (13%), and remained so through subsequent treatment cycles, with no evidence of cumulative toxicity or tolerance.

CONCLUSIONS

Long-term treatment with tetrodotoxin is associated with acceptable toxicity and, in a substantial minority of patients, resulted in a sustained analgesic effect. Further study of tetrodotoxin for moderate-to-severe cancer pain is warranted.

Analysis of mechanisms of Cisplatin resistance in 3 pairs of human tumor-cell lines expressing normal and resistant responses to Cisplatin

Three pairs of human tumour cell Lines each having a cisplatin sensitive parental cell line (normal) and a cisplatin resistant derivative were tested for their cisplatin responses and expression for three reputed mechanisms of resistance. In each case, the derivative cell lines showed resistance to cisplatin when treated either in exponential or plateau growth phase. For both the resistant and the normal cell line there was greater resistance to cisplatin treatment when cells were treated in exponential growth phase. Mechanisms of resistance were expressed in all three resistant variants. The cervical carcinoma resistant variant expressed higher GSH levels and lower cisplatin uptake levels but not elevated polymerase levels. The other two variant cell lines for the glioma and the lung cancer expressed all three of the mechanisms (increased GSH, decreased cisplatin uptake and increased polymerases) associated with resistance. There was no correlation to the level of resistance expressed and the number of mechanisms expressed but the change in response of the parental line to becoming a resistant variant may be related to the basal level of expression of some of the factors that are associated with resistance.

Concurrent use of multiple chemotherapy resistance modulators with etoposide in patients with resistant malignancies

Since chemotherapy resistance is probably multifactorial, we studied the toxicity and efficacy of adding to etoposide in sequence 5 resistance modulators in the treatment of resistant solid tumors. In cohort 1, metronidazole and ketoconazole were given with i.v. etoposide 100 mg/m(2)/day x 5 days. Because of excessive toxicity, cohort 2 received just metronidazole with etoposide, and metronidazole doses were reduced. Subsequent patient cohorts had the following drugs added to etoposide plus metronidazole: ketoconazole (cohort 3), dipyridamole (cohort 4), tamoxifen [cohort 5 (with etoposide 75 mg/m(2)/day) and 6 (with etoposide 60 mg/m(2)/day)], and cyclosporin (cohort 7). Hence, cohort 7 received daily x 5 i.v. etoposide 60 mg/m(2)/day plus 5 resistance modulators. Forty patients were treated, of whom 38 were evaluable for toxicity. Metronidazole resulted in augmentation of both central neurotoxicity and peripheral neuropathy. Sequential addition of each of dipyridamole, tamoxifen, and cyclosporin appeared to increase hematological toxicity. Some patients also experienced reversible hepatic and renal toxicity. Partial responses were seen in adrenocortical and small cell lung cancers, and minor responses with symptomatic improvement were seen in adrenocortical, small cell lung, non-small cell lung and colorectal carcinomas. Further evaluation of this approach may be warranted in patients with minimal prior chemotherapy exposure.

Endoscopic submucosal dissection of gastric lesions by using a master and slave transluminal endoscopic robot: an animal survival study

BACKGROUND AND STUDY AIMS

The feasibility of performing endoscopic submucosal dissection (ESD) using the Master and Slave Transluminal Endoscopic Robot (MASTER), a robotics-enhanced surgical system, has been shown in our previous study. This study aimed to further explore, in an animal survival study, the 2-week outcome of using MASTER to perform ESD.

PATIENTS AND METHODS

In this prospective study, ESD was performed on five female pigs (weighing 32.4 - 36.8 kg) under general anesthesia using the MASTER. The animals were observed for 2 weeks before being humanely killed for necropsy examination. The main outcome measures were completeness of resection, procedure-related complications, and survival at 2 weeks.

RESULTS

The procedure was successfully completed in all five pigs. It took a mean of 21.8 minutes (range 6 - 39 minutes) to complete the ESD of each gastric lesion. All lesions were excised en bloc; the average dimension of the lesions was 77 mm (range 25 - 104 mm). One pig sustained a small intraoperative perforation which was identified and successfully clipped. After completion of the ESD procedures, all pigs survived well for 2 weeks. Necropsy was performed, with intraoperative gastroscopy identifying all the ESD sites as healed. Histopathologic examination showed all ESD sites had healed with partial epithelialization. Microbiological tests of the peritoneal fluid showed only microbes typically found in pigs.

CONCLUSION

Performing ESD with MASTER was feasible and safe in this 2-week animal survival study.

Eastern Canadian colorectal cancer consensus conference: application of new modalities of staging and treatment of gastrointestinal cancers

The annual Eastern Canadian Colorectal Cancer Consensus Conference was held in Ottawa, Ontario, October 22-23, 2010. Health care professionals involved in the care of patients with colorectal cancer participated in presentation and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancer, such as the use of epidermal growth factor inhibitors in metastatic colon cancer, the benefit of calcium and magnesium with oxaliplatin chemotherapy, the role of microsatellites in treatment decisions for stage II colon cancer, the staging and treatment of rectal cancer, and the management of colorectal and metastatic pancreatic cancers.

Mortality, health care utilization and associated diagnoses in hospitalized patients with haemophilia in the United States: first reported nationwide estimates

To describe the in-hospital epidemiology of haemophilia A and B in the US we analysed the National Inpatient Sample (NIS), a stratified probability sample of 20% of all hospital discharges in the US for the year 2007. We applied sampling weights to represent all hospital discharges for haemophilia A and B identified using ICD-9 codes 286.0 and 286.1, respectively. Haemophilia (A or B) was one of all the listed diagnoses in 9737 discharges and principal diagnosis in 1684 discharges. The most common associated diagnoses in discharges with Haemophilia in adults and children were hypertension (28.1 ± 1.6%) and central line infections (15.2 ± 1.8%) respectively. No Hepatitis C or HIV was reported in children. Among 212 deaths, associated diagnoses included sepsis (37.9%), heart failure (30.2%), respiratory failure (28.3%), pneumonia (24.5%), HIV (14.2%), hepatic coma (5.2%) and intracranial haemorrhage (2.3%). All fifteen reported paediatric deaths occurred on day zero of life, the commonest associated diagnoses being Intraventricular haemorrhage and newborn haemorrhage-NOS (33% each). Median age of in-hospital mortality for diagnosis of Haemophilia was 68.3 years as compared to 72.3 years for all males for all hospitalizations in NIS combined. Mean hospital charges for haemophilia of $76823 ± 5530 were significantly higher than those from all causes of hospitalization of $26,120 ± 562. In-hospital mortality is rare in children with haemophilia beyond the neonatal period and age of mortality in adults is approaching that of the general male population. Hospitalization in children is most often due to central line infections and hospitalization and death in adults is primarily due to age-related illnesses.

Clinico-pathological correlation of non specific inflammation in bowel histology with joint manifestation in a tertiary center in South India

The aim of our study was to determine whether the pattern of arthropathy in patients with suspected enteropathic arthritis bore any relation to their gut histology and specifically to chronic nonspecific gut inflammation. Records of 39 patients with suspected enteropathic arthritis from rheumatology clinic between January 2006 and December 2008 who had undergone ileocolonoscopic biopsy were analyzed retrospectively. Patients were grouped into 3 categories, namely those with normal bowel histology, those with mild nonspecific chronic changes, and those with histology suggestive of inflammatory bowel disease. Patients with nonspecific chronic gut inflammation had higher occurrence of axial involvement with or without peripheral articular involvement as compared to those with normal gut histology (8/9 vs. 10/21, P = 0.049), and this pattern was similar to that in patients with IBD. Wrist joint involvement was more common in patients with normal bowel histology (12/21) than the other two groups (P = 0.003). All groups had fared well on follow up while taking treatment with sulphasalazine and methotrexate.

P4-15-01: High Prevalence of Prospective Memory (PM) Impairment in Early Breast Cancer (EBC) Survivors within 1 Year of Adjuvant Chemotherapy Completion: Novel Findings Concerning Post Chemotherapy Cognitive Effects

Background Numerous studies have demonstrated that EBC survivors report more memory problems than healthy controls. However, evidence of impairment on objective tests of memory remains inconclusive. Past research has focussed exclusively on retrospective memory (remembering information from the past when asked to do so), but the complaints of EBC patients appear better described as “prospective memory” failures defined as forgetting to carry out in the future previously formed intentions. The effective performance of many day-to-day activities relies on PM and its impairment has negative consequences in everyday life. Despite its high ecological relevance, no study has evaluated PM functioning in EBC survivors. Consequently, we assessed the prevalence of PM impairment among EBC survivors in the year following completion of chemotherapy. Methods We undertook a cross sectional quantitative case-control study aiming to recruit 80 patients from the Ottawa Hospital Regional Cancer Centre and 80 matched healthy controls from the community. Patients were within 1 year of having completed a first course of chemotherapy. A standardized test of prospective memory (Memory for Intention Screening Test) was administered to both groups. Following the International Cognition and Cancer Task Force recommendation (2008), impairment was defined as a score that fell one standard deviation below the mean performance of the control group. Standardized measures of depression (CESD), anxiety (STAI) and fatigue (Fact-F) were also completed. Results Data are available on 36 patients and 18 controls. Age was well balanced between the groups (case-control mean age 54y vs. 51y, respectively, p=.204). Overall PM impairment was observed in 41% of the participants. More importantly, the rate of PM impairment was significantly higher in the EBC group than controls (53% vs 17%; p < 0.005; odds ratio = 5.588; 95% CI=1.376 to 22.7). Multivariate logistic regression showed that PM performance was unaffected by age (p=0.459), depression (p=0.358), anxiety (p=0.512) or fatigue (p=0.595). Conclusions These preliminary findings provide further support for the hypothesis that breast cancer treatment can impair cognitive processes and yield new and important insights into the type of memory problems experienced by EBC survivors. They suggest that a significant proportion of patients exhibit deficits in PM, an aspect of memory involved in effective daily functioning. Our results also suggest that emotional distress and fatigue do not contribute to PM functioning. Further studies in this area should be directed at understanding the severity and duration of PM impairment. Acknowledging and studying this vexing problem in EBC survivors will aid in developing appropriate rehabilitation strategies.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-15-01.

Eastern Canadian Colorectal Cancer Consensus Conference: setting the limits of resectable disease

The annual Eastern Canadian Colorectal Cancer Consensus Conference was held in Montreal, Quebec, October 22-24, 2009. Health care professionals involved in the care of patients with colorectal cancer participated in presentation and discussion sessions for the purposes of developing the recommendations presented here. This consensus statement addresses current issues in the management colorectal cancer, such as the management of hepatic and pulmonary metastases, the role of monoclonal antibodies to the epidermal growth factor receptor, and the benefits and safety of chemotherapy in elderly patients. The management of gastrointestinal neuroendocrine tumours and gastric cancer are also discussed.

Diagnosis and management of hepatocellular carcinoma: results of a consensus meeting of The Ottawa Hospital Cancer Centre

Hepatocellular carcinoma (HCC) is an uncommon tumour, but its incidence is increasing in Canada and elsewhere. Currently, there are no Canadian recommendations for diagnosis and treatment of hcc, and possible options may have regional limitations. A consensus symposium was held in the Ottawa region to consider current diagnostic and management options for hcc. These recommendations were developed: Diagnosis-with adequate imaging, a biopsy is not required pre-surgery, but is required before the start of systemic therapy; lesions smaller than 1 cm should be followed and not biopsied; repeat biopsies should be core tissue biopsies; magnetic resonance imaging is preferred, but triphasic computed tomography imaging can be useful. Resection-recommended for localized HCC. Radiofrequency ablation-recommended for unresectable or non-transplantable HCC; should not be performed in the presence of ascites. Trans-arterial chemoembolization (TACE)-doxorubicin with lipiodol is the agent of choice; trans-catheter embolization is an alternative for patients if TACE is not tolerated or is contraindicated. Medical management-first-line sorafenib should be considered the standard of care. Transplantation-suitable patients meeting Milan criteria should be assessed for a graft regardless of other treatments offered. The authors feel that the recommendations from this consensus symposium may be of interest to other regions in Canada.

Endocrine changes in male HIV patients

AIMS AND OBJECTIVES

To determine the frequency of adrenal, thyroid and gonadal dysfunction in HIV positive male patients and to evaluate the endocrine function at different level of CD4 cell counts.

MATERIAL AND METHODS

A total of 150 male HIV positive subjects were included in study. The patients were divided in three groups on the basis of CD4 cell counts. "Group A": HIV positive with CD4 count<200/mm "Group B": HIV positive with CD4 count 200-350/mm3 and "Group C": HIV positive with CD4 count>350/mm3.

RESULTS

In "group A" (n=50) 2 patients had basal cortisol<5 microg/dl while 23 patients had basal cortisol>25 microg/ dl. 15 patients had subclinical hypothyroidism while 11 patients had overt hypothyroidism. 25 patients in this group had gonadal dysfunction: majority of them (24) had primary gonadal dysfunction (elevated LH). None of the patients in "group B" (n=50) had hypocortisolism while 11 patients had elevated cortisol; 18 had subclinical hypothyroidism while 4 had overt hypothyroidism while 17 patients were hypogonad, all having elevated LH. In "group C" (n=50) 2 patients had hypocortisolism and 5 had elevated cortisol; 12 patients had subclinical and one had overt hypothyroidism; 7 patients had primary hypogonadism and one had secondary hypogonadism. Overall 4(2.66%) had hypocortisolism while 39 (26%) had elevated cortisol; 45 (30%) had subclinical hypothyroidism while 16(10.66%) had overt hypothyroidism. Gonadal dysfunction was observed in 50 patients (33%) majority of them (48) had primary hypogonadism. On analysis of Pearson's correlation coefficient CD4 count has strong inverse correlation with basal cortisol (r=-0.301, p<0.0001), TSH (r=-0.257, p=0.002) and LH (r=-0.228, p=0.006), while there was a direct correlation with serum testosterone (r=0.175, p=0.037).

CONCLUSION

This pilot study has demonstrated a high incidence of endocrine dysfunction in HIV infected patient in this part of country. High incidence of thyroid and gonadal dysfunction may contribute to morbidity of the patients and have a bearing on quality of life of the HIV infected patients. Hypocortisolism was not that common but high level of cortisol may be a marker of stress due to HIV per se or due to associated infection. Many of these dysfunctions might be transient and a large longitudinal study should be undertaken to substantiate the finding of the present study.

Novel anaerobic digestion process with sludge ozonation for economically feasible power production from biogas

A novel process scheme was developed to achieve economically feasible energy recovery from anaerobic digestion. The new process scheme employs a hybrid configuration of mesophilic and thermophilic anaerobic digestion with sludge ozonation: the ozonated sludge is first degraded in a thermophilic digester and then further degraded in a mesophilic digester. In small-scale pilot experiments of the new process scheme, degradation of VSS improved by 3.5% over the control (mesophilic-only configuration) with 20% less ozone consumption. Moreover, biogas conversion also improved by 7.1% over the control. Selective enrichment of inorganic compounds during centrifugation produced a dewatered sludge cake with very low water content (59.4%). This low water content in the sludge cake improved its auto-thermal combustion potential during incineration and added to the overall energy savings. We conducted a case study to evaluate power generation from biogas for a municipal wastewater treatment plant with an average dry weather flow of 43,000 m3/d. Electricity production cost was 5.2 ¢/kWh for the advanced process with power generation, which is lower than the current market price of 7.2 ¢/kWh. The new anaerobic digestion scheme with power generation may reduce greenhouse gas emissions by about 1,000 t-CO(2)/year compared with the conventional process without power generation.