Microbial fuel cells for direct electrical energy recovery from urban wastewaters.

Application of microbial fuel cells (MFCs) to wastewater treatment for direct recovery of electric energy appears to provide a potentially attractive alternative to traditional treatment processes, in an optic of costs reduction, and tapping of sustainable energy sources that characterizes current trends in technology. This work focuses on a laboratory-scale, air-cathode, and single-chamber MFC, with internal volume of 6.9 L, operating in batch mode. The MFC was fed with different types of substrates. This study evaluates the MFC behaviour, in terms of organic matter removal efficiency, which reached 86% (on average) with a hydraulic retention time of 150 hours. The MFC produced an average power density of 13.2 mW/m(3), with a Coulombic efficiency ranging from 0.8 to 1.9%. The amount of data collected allowed an accurate analysis of the repeatability of MFC electrochemical behaviour, with regards to both COD removal kinetics and electric energy production.

Recombinant adenoviral vector-lipofectAMINE complex for gene transduction into human T lymphocytes.

We have evaluated, as a vector for gene transfer into human T lymphocytes, a recombinant adenovirus (rAd-MFG-AP) carrying a modified, membrane-exposed, alkaline phosphatase (AP) as reporter gene. CD3+ cells were selected from the buffy coat of healthy donors by the immunomagnetic technique. The positive cell population, comprising 96+/-2% CD3+ cells, was cultured with clinical-grade cytokine(s) for 3-7 days prior to rAd-MFG-AP transduction and the transgene expression was evaluated 48 hr later by indirect immunofluorescence flow cytometry assay with an anti-alkaline phosphatase antibody. The best efficiency of transduction was achieved on incubation of CD3+ cells with IL-2 plus either IL-12 (AP+ cells, 12+/-3%) or IL-7 (AP+ cells, 11+/-3%). To increase further the efficiency of transduction, we have combined LipofectAMINE and rAd-MFG-AP with the aim to enhance the uptake of viral particles into the target cells. The percentage of CD3+ cells transduced by rAd-MFG-AP-LipofectAMINE complex was 24+/-4% (range, 20-35%) after incubation with IL-2 plus IL-7 and 22+/-4% (range, 18-32%) after incubation with II-2 plus IL-12. Forty-eight hours after the incubation with rAd-MFG-AP, the transduced T lymphocytes were subjected to fluorescence-activated cell sorting and fractionated into AP+ and AP- cell subpopulations. The AP+ cell fraction, comprising 96.8% of AP+ cells, was evaluated by FACScan analysis for T lymphocyte surface antigens. The immunophenotyping of the transduced T lymphocytes has shown that there was not a particular subtype of T lymphocytes more susceptible to rAd-MFG-AP transduction. In addition, the transgene expression did not modify T lymphocyte functions, as demonstrated by results obtained by cytotoxicity assay before and after rAd-MFG-AP-LipofectAMINE complex transduction. In conclusion, human T lymphocytes can be efficiently transduced, under clinically applicable conditions, by adenovirus-LipofectAMINE complex after 7 days of culture with IL-2 and IL-12 or IL-7.

Gene transfer into human dendritic antigen-presenting cells by vaccinia virus and adenovirus vectors.

In a search for means to deliver exogenous gene(s) into human dendritic cells (DCs) from the perspective of tumor-specific vaccination, we have evaluated two recombinant viruses, both of which carry a reporter gene which is namely a modified vaccinia virus Ankara (MVA) and an adenovirus, as possible expression vectors. The recombinant MVA-P11 LZ vector carries the Escherichia coli lacZ gene coding for the enzyme beta-galactosidase, and the recombinant Ad-MFG-AP vector carries a modified membrane-exposed alkaline phosphatase (AP) gene. DCs were generated ex vivo in the presence of tumor necrosis factor-alpha, granulocyte macrophage colony-stimulating factor, stem cell factor, and flk-2/flt-3 ligand taken from CD34+ hematopoietic progenitors that were mobilized into the peripheral blood of cancer patients treated with high-dose cyclophosphamide and filgrastim. The target cells used for gene delivery were either CD34+ cells that had been subsequently induced to differentiate into mature DCs or DCs transduced after ex vivo generation from CD34+ cells. The results showed that: (a) infection of CD34+ cell derived-DCs (mature DCs) with either viral vector resulted in the efficient synthesis of recombinant protein, and (b) CD34+ cells were permissive for the expression of the recombinant reporter gene after infection with Ad-MFG-AP but not after infection with MVA-P11 LZ. In conclusion, these results suggest that vaccinia and adenovirus vectors are candidate to act as vehicles in genetically engineering human DCs.

Altered pattern of circadian neural control of heart period in mild hypertension.

We addressed the problem of the circadian changes in neural control of heart period in ambulant hypertensive subjects. A running spectral analysis of R-R variability from Holter tapes provided markers of sympathetic, i.e. low-frequency component (LF) almost equal to 0.10 Hz, and vagal, i.e. high-frequency component (HF) almost equal to 0.25 Hz, controlling activities for the 24-h period of the recording. Significant circadian differences were observed in LF between the two groups of subjects: during night-time rest (0300-0400 h), LF was greater in hypertensives than in normotensives (56 +/- 2 and 48 +/- 2 nu, respectively; P less than 0.05). Furthermore, the difference between daytime and night-time LF values was progressively reduced with increasing severity of the hypertensive state, as assessed by resting arterial pressure levels. Spectral analysis of R-R variability suggests that essential hypertension may be characterized by a reduced day-night oscillation in sympathetic activity than can be quantified non-invasively using this approach.

Increased retinol binding protein in the sera of patients with severe ischemic damage of the liver after transplantation.

OBJECTIVE: To study retinol binding protein variation in the serum of patients who have undergone liver transplantation. METHODS: Retinol binding protein was retrospectively determined by the immunonephelometric method on serum from 14 patients who had undergone orthotopic liver transplantation 2 weeks after the surgery and then once a month during the first year posttransplantation. The patients were divided into two groups on the basis of early (first 10 days) postoperative graft function: group I, 6 patients with severe ischemic damage; and II 8 patients with moderate-severe liver dysfunction. RESULTS: The men retinol binding protein level at one year of follow-up was persistently higher in group I than in group II (83.1 +/- 33.4 vs 44.6 +/- 20.7 mg/L, p < 0.001). Interestingly, retinol binding protein levels remained higher in patients of group I event when the other biochemical parameter of liver function returned to normal. The increase in retinol binding protein serum levels was independent of variation in other parameters of liver and kidney function, but was correlated with an increase in transthyretin and retinol levels. CONCLUSION: Our results show a close relationship between a permanent high retinol binding protein level and severe graft injury after liver transplantation. However, the mechanism underlying the increase remains to be defined.

Effects of dimethylformamide (DMF) on coagulation and platelet activity.

The effects of dimethylformamide (DMF) on hemostatic functions, especially on platelet activity, were examined both in vitro and in vivo in 15 workers exposed to DMF (27 mg/m3, median value). Twenty-eight control subjects who were not exposed to DMF, but comparable for age, anthropometric data, and smoking habits, were also studied. Workers exposed to DMF showed a decrease in the number of platelets and had longer coagulation times, probably due to a change caused by DMF on the membrane receptor of platelets and on the phospholipid components of the clotting system.

Importance of pyridoxal-5'-phosphate addition to the assay medium for the measurement of catalytic concentrations of plasma aspartate and alanine aminotransferases in patients undergoing antineoplastic chemotherapy.

Using 98 plasma samples from cancer patients undergoing antineoplastic chemotherapy, we compared the activities of aspartate aminotransferase and alanine aminotransferase measured by two different methods, with and without the addition of pyridoxal-5'-phosphate to the assay medium. Pyridoxal-5'-phosphate caused an increase of 1 to 20 U/l in aspartate aminotransferase and alanine aminotransferase activity in 90 and 78 patient plasma samples, respectively. Increases of aspartate aminotransferase and alanine aminotransferase activity of more than 20 U/l were observed in 8 and 20 samples, respectively. In 8 cases, the increase in alanine aminotransferase activity was greater than 50 U/l, whereas a similar increase in aspartate aminotransferase activity was decreased in only 2 cases. The considerable pyridoxal-5'-phosphate activation in aminotransferase activity observed in the plasma of a significant number of patients suggests that the use of the method with pyridoxal-5'-phosphate is advisable for a correct measurement of the catalytic concentration of aminotransferases in the plasma of patients undergoing chemotherapy.

Identification of a streptococcal penicillin-binding protein that reacts very slowly with penicillin.

Penicillin-binding protein (PBP) 5 of Streptococcus faecium ATCC 9790 has an unusually low affinity for penicillin (50% binding occurred at a penicillin level of 8 micrograms/ml after 60 min of incubation, and the protein only became labeled after 20 min of incubation with high concentrations of radioactive penicillin). PBPs with similar properties are carried by strains of Streptococcus durans, Streptococcus faecalis, and Streptococcus lactis but not by strains of groups A, B, C, and G streptococci or Streptococcus pneumoniae. The strains carrying the slow-reacting PBP demonstrated a sensitivity to penicillin that was several hundred times lower than that of strains not carrying it. Spontaneous mutants with minimal inhibitory concentrations of penicillin of 20, 40, and 80 micrograms/ml were isolated from S. faecium ATCC 9790. They all showed a dramatic increase in the amount of slow-reacting PBP produced. Mutants with increased penicillin resistance were also isolated from wild-type strains of S. durans, S. faecalis, and S. faecium. All of them carried a greater amount of the slow-reacting PBP than that carried by the parent. Finally, it was found that resistant S. faecium ATCC 9790 mutants grew normally in the presence of penicillin concentrations that were far above that saturating all PBPs except PBP 5. Cell growth was, on the contrary, inhibited by a penicillin concentration that saturated the slow-reacting PBP by 90%. This penicillin dose was equal to the minimal inhibitory concentration.

[Platelet aggregation and resistance to osmotic shock of platelet concentrates obtained by discontinuous-flow cell separation with the surge pump technic]. / Aggregazione piastrinica e resistenza allo shock osmotico di concentrati piastrinici ottenuti mediante separatore cellulare a flusso discontinuo con la tecnica "surge pump".

We studied the ultrastructural morphology and function of platelets collected by apheresis procedure with discontinuous flow using the Surge Pump Technique. The platelet concentrates obtained by this technique are free of erythrocyte and lymphocyte contamination. The platelet morphology as well as the platelet aggregation induced by ADP, adrenaline and collagen of platelet concentrates were similar to those observed in PRP before the apheresis. The response to the hypotonic shock of platelet concentrates was also normal, indicating membrane integrity and good platelet metabolism. These results show that platelet concentrates obtained by the Surge Pump Technique maintain their haemostatic effects and may be infused in thrombocitopenic patients, reducing the risk of alloimmunization related to the presence of erythrocytes and lymphocytes.

[Changes induced by dimethylformamide on platelet function and coagulation activity]. / Modificazioni indotte da dimetilformamide (DMF) sulla funzionalita' piastrinica e sull'attivita' coagulativa.

The effect of Dimethylformamide on platelet function and on clotting system has been studied on eight workers exposed to the product, widely used in industry as a solvent of acrylic resins. A significant reduction of the number of the platelets and a drawing out of PTT and PT has been noticed. Such informations has been explained as chronical peripheral use or as modification of phospholipid components induced by DMF instead of synthesis defect, as no significant variation of the fibrinogen and of AT III values, proteins synthetized by liver, has been observed. The platelet aggregation has pointed out, in vivo, a reduction of ADP aggregation in the exposed subjects; in vitro, increasing quantities have determined an increasing reduction of the primary ADP and adrenaline aggregation.

Large-scale feasibility of gene transduction into human CD34+ cell-derived dendritic cells by adenoviral/polycation complex.

With a view to using multiple injections of anti-cancer dendritic cell (DC)-based vaccines, we evaluated the feasibility of the adenoviral transduction of large amounts of human CD34+ cell-derived DCs, and analysed the persistence of the transgene expression and the integrity of DC functional activity after the transduction/cryopreservation procedures. Mature DCs generated from highly enriched human CD34+ cells were transduced by a recombinant adenovirus (rAd-MFG) that carried a modified, membrane-exposed, alkaline phosphatase (AP) sequence as the reporter gene. Cationic lipids such as LipofectAmine or poly-L-lysine were mixed with the viral particles before the transduction of the target cells. The highest transduction efficiency was obtained at a multiplicity of infection (MOI) rate of 500 (AP + DCs: 50 +/- 2%, viability =95%) under both small- and large-scale conditions. The addition of poly-L-lysine or LipofectAmine increased the percentage of transduced cells at an MOI of 500 (CD1a+/AP+ cells = 85 +/- 3% and 80 +/- 2% respectively). Polycations made it possible to reduce the amounts of viral particles, with high efficiency of transduction being achieved at a MOI of 100 with 10 microg/ml poly-L-lysine (CD1a+/AP+: 68 +/- 9%) or 30 microg/ml LipofectAmine (CD1a+/AP+: 60 +/- 7%). Evaluation of the immunophenotype of the transduced DCs showed that the lack of a DC subpopulation was more susceptible to adenoviral transduction. Cryopreservation of transduced DCs did not modify the viability or percentage of AP+ cells that maintain antigen-presenting cell (APC) functions. These findings indicate the efficacy of this method for the transduction of large amounts of CD34+ cell-derived DCs using small quantities of adenoviral vector mixed with polycations. Cryopreservation of transduced DCs did not damage their viability or APC functions, thus making it possible to plan multiple injections of engineered DC-based vaccines.