Treatment of non-resectable hepatocellular carcinoma with autologous tumor-pulsed dendritic cells

Background: The response of hepatocellular carcinoma (HCC) to therapy is often disappointing and new modalities of treatment are clearly needed. Active immunotherapy based on the injection of autologous dendritic cells (DC) co-cultured ex vivo with tumor antigens has been used in pilot studies in various malignancies such as melanoma and lymphoma with encouraging results. Methods: In the present paper, the preparation and exposure of patient DC to autologous HCC antigens and re-injection in an attempt to elicit antitumor immune responses are described. Results: Therapy was given to two patients, one with hepatitis C and one with hepatitis B, who had large, multiple HCC and for whom no other therapy was available. No significant side-effects were observed. The clinical course was unchanged in one patient, who died a few months later. The other patient, whose initial prognosis was considered poor, is still alive and well more than 3 years later with evidence of slowing of tumor growth based on organ imaging. Conclusions: It is concluded that HCC may be a malignancy worthy of DC trials and sufficient details in the present paper are given for the protocol to be copied or modified. (C) 2002 Blackwell Publishing Asia Pty Ltd.

Exceptionally high-rate nitrification in sequencing batch reactors treating high ammonia landfill leachate

The nitrogen removal capacity of a suspended culture system treating mature landfill leachate was investigated. Leachate containing high ammonium levels of 300-900 mg N/L was nitrified in a bench scale sequencing batch reactor. Leachate from four different landfills was treated over a two year period for the removal of nitrogen. In this time, a highly specific nitrifying culture was attained that delivered exceptionally high rates of ammonia removal. No sludge was wasted from the system to increase the throughput and up to 13 g/L of MLSS was obtained. Settleability of the purely nitrifying biomass was excellent with SVI less than 40 mL/g, even at the high sludge concentrations. Nitrification rates up to 246 mg NI(L h) (5.91 g N/(L d)) and specific nitrification rates of 36 mg N/(gVSS h) (880 mg N/(gVSS d)) were obtained. The loading to the system at this time allowed complete nitrification of the leachate with a hydraulic retention time of only 5 hours. Following these successful treatability studies, a full-scale plant was designed and built at one of the landfills investigated.

Performance of hydrophobic and hydrophilic silica membrane reactors for the water gas shift reaction

In this study, a novel molecular sieve silica (MSS) membrane packed bed reactor (PBR) using a Cu/ZnO/Al2O3 catalyst was applied to the low-temperature water gas shift reaction (WGS). Best permeation results were H-2 permeances of 1.5 x 10(-6) mol(.)s(-1) m(-2) Pa-1, H-2/CO2 selectivities of 8 and H-2/N-2 selectivities of 18. It was shown that an operation with a sweep gas flow of 80 cm 3 min(-1), a feed flow rate of 50 cm(3) min(-1) and a H2O/CO molar ratio of one at 280 degreesC reached a 99% CO conversion. This is well above the thermodynamic equilibrium and achievable PBR conversion. Hydrophilic membranes underwent pore widening during the reaction while hydrophobic membranes indicated no such behaviour and also showed increased H-2 permeation with temperature, a characteristic of activated transport. (C) 2003 Elsevier Science B.V. All rights reserved.

Fluorescence in situ hybridization analysis of nitrifiers in piggery wastewater treatment reactors

Fluorescence in situ hybridization (FISH) was performed to analyze the nitrifying microbial communities in an activated sludge reactor (ASR) and a fixed biofilm reactor (FBR) for piggery wastewater treatment. Heterotrophic oxidation and nitrification were occurring simultaneously in the ASR and the COD and nitrification efficiencies depend on the loads. In the FBR nitrification efficiency also depends on ammonium load to the reactor and nitrite was accumulated when free ammonia concentration was higher than 0.2 mg NH3-N/L. FISH analysis showed that ammonia-oxidizing bacteria (NSO1225) and denitrifying bacteria (RRP1088) were less abundant than other bacteria (EUB338) in ASR. Further analysis on nitrifying bacteria in the FBR showed that Nitrosomonas species (NSM156) and Nitrospira species (NSR1156) were the dominant ammonia-oxidizing and nitrite-oxidizing bacteria, respectively, in the piggery wastewater nitrification system.

Flow regime, hydrodynamics, floc size distribution and sludge properties in activated sludge bubble column, air-lift and aerated stirred reactors

This paper presents a comparative study how reactor configuration, sludge loading and air flowrate affect flow regimes, hydrodynamics, floc size distribution and sludge solids-liquid separation properties. Three reactor configurations were studied in bench scale activated sludge bubble column reactor (BCR), air-lift reactor (ALR) and aerated stirred reactor (ASR). The ASR demonstrated the highest capacity of gas holdup and resistance, and homogeneity in flow regimes and shearing forces, resulting in producing large numbers of small and compact floes. The fluid dynamics in the ALR created regularly directed recirculation forces to enhance the gas holdup and sludge flocculation. The BCR distributed a high turbulent flow regime and non-homogeneity in gas holdup and mixing, and generated large numbers of larger and looser floes. The sludge size distributions, compressibility and settleability were significantly influenced by the reactor configurations associated with the flow regimes and hydrodynamics.

Pulsed EPR studies of a bacterial sulfite-oxidizing enzyme with pH-invariant hyperfine interactions from exchangeable protons

Variable-frequency pulsed electron paramagnetic resonance studies of the molybdenum(V) center of sulfite dehydrogenase (SDH) clearly show couplings from nearby exchangeable protons that are assigned to a (MoOHn)-O-v group. The hyperfine parameters for these exchangeable protons of SDH are the same at both low and high pH and similar to those for the high-pH forms of sulfite oxidases (SOs) from eukaryotes. The SDH proton parameters are distinctly different from the low-pH forms of chicken and human so.

Nanoassembly of biocompatible microcapsules for urease encapsulation and their use as biomimetic reactors

Biocompatible polypeptide capsules with high enzyme loading and activity prepared by templating mesoporous silica spheres were used as biomimetic reactors for performing CaCO3 synthesis exclusively inside the capsule interior via urease-catalyzed urea hydrolysis.

Hydrodynamics and mass transfer coefficient in three-phase air-lift reactors containing activated sludge

This study was to investigate the impacts of operating conditions and liquid properties on the hydrodynamics and volumetric mass transfer coefficient in activated sludge air-lift reactors. Experiments were conducted in internal and external air-lift reactors. The activated sludge liquid displayed a non-Newtonian rheological behavior. With an increase in the superficial gas velocity, the liquid circulation velocity, gas holdup and mass transfer coefficient increased, and the gas residence time decreased. The liquid circulation velocity, gas holdup and the mass transfer coefficient decreased as the sludge loading increased. The flow regime in the activated sludge air-lift reactors had significant effect on the liquid circulation velocity and the gas holdup, but appeared to have little impact on the mass transfer coefficient. The experimental results in this study were best described by the empirical models, in which the reactor geometry, superficial gas velocity and/or power consumption unit, and solid and fluid properties were employed. (c) 2006 Elsevier B.V. All rights reserved.

Applicability of experience from laboratory reactors with biological phosphorus removal in full-scale plants

Enhanced biological phosphorus removal (EBPR) has been used at many wastewater treatment plants all over the world for many years. In this study a full-scale sludge with good EBPR was tested with P-release batch tests and combined FISH/MAR (fluorescence in situ hybridisation and microautoradiography). Proposed models of PAOs and GAOs (polyphosphate- and glycogen-accumulating organisms) and microbial methods suggested from studies of laboratory reactors were found to be applicable also on sludge from full-scale plants. Dependency of pH and the uptake of both acetate and propionate were studied and used for calculations for verifying the models and results from microbial methods. All rates found from the batch tests with acetate were higher than in the batch tests with propionate, which was explained by the finding that only those parts of the bacterial community that were able to take up acetate anaerobically were able to take up propionate anaerobically.

Archaeal diversity in two thermophilic chalcopyrite bioleaching reactors

This study used a culture-independent molecular approach to investigate the archaeal community composition of thermophilic bioleaching reactors. Two culture samples, MTC-A and MTC-B, grown with different concentrations of chalcopyrite (CuFeS2), a copper sulfidic ore, at a temperature of 78 degrees C and pH 1.6 were studied. Phylogenetic analysis of the 16S rRNA genes revealed that both cultures consisted of Archaea belonging to the Sulfolobales. The 16S rRNA gene clone library of MTC-A grown with 4% (w/v) chalcopyrite was dominated by a unique phylotype related to Sulfolobus shibatae (69% of total clones). The remaining clones were affiliated with Stygiolobus azoricus (11%), Metallosphaera sp. J1 (8%), Acidianus infernus (2%), and a novel phylotype related to Sulfurisphaera ohwakuensis (10%). In contrast, the clones from MTC-B grown with 12% (w/v) chalcopyrite did not appear to contain Sulfolobus shibatae-like organisms. Instead the bioleaching consortium was dominated by clones related to Sulfurisphaera ohwakuensis (73.9% of total clones). The remaining microorganisms detected were similar to those found in MTC-A.

Comparison of cellulose solubilisation rates in rumen and landfill leachate inoculated reactors

The aim of this study was to conduct a number of controlled digestions to obtain easily comparable cellulose solubilisation rates and to compare these rates to those found in the literature to see which operational differences were significant in affecting cellulose degradation during anaerobic digestion. The results suggested that differences in volumetric cellulose solubilisation rates were not indicative of the true performance of cellulose digestion systems. When cellulose solubilisation rates were normalised by the mass of cellulose in the reactor at each time step, the comparison of the rates became more meaningful. Cellulose solubilisation was surface area limited. Therefore, changes in the loading rate of cellulose to the reactor altered the volumetric solubilisation rate without changing the mass normalised rate. Comparison of mass normalised solubilisation rates from this study and the literature demonstrated that differences in reactor configuration and operational conditions did not significantly impact on the solubilisation rate whereas the difference in composition of the microbial communities showed a marked effect. This work highlights the importance of using appropriately normalised data when making comparisons between systems with differing operational conditions. (c) 2005 Elsevier Ltd. All rights reserved.