Land application of municipal landfill leachate: fate of ions and ammonia volatilization.

Landfill leachates are pollutants rich in ammoniacal N, Na, and K, but land application potentially offers an alternative for recycling these leachate nutrients. We applied landfill leachate corresponding to 0, 110, 220, 330, and 440 kg ha of total N, divided in three applications (July, August, and October 2008), onto the surface of an acidic (pH 5.5-6.0) clay (79% clay) Ultisol and monitored NH volatilization just after applications and microbiological (0-10 cm) and chemical attributes (0-60-cm soil depth) in August 2008, January 2009, and May 2009. Ammonium (up to 30 mg kg), NO (up to 160 mg kg), Na, K (up to 1.1 cmol kg each), and electrical conductivity (up to 1 dS m) increased transiently in soil following applications. Despite >90% of the total leachate N being ammoniacal, NO predominated in the first soil sampling, 14 d after the second application, suggesting fast nitrification, but it decreased in the soil profile thereafter. From 5 to 25% of the total applied N volatilized as NH, with maximum losses within the first 3 d. Applications inhibited (50%) the relative nitrification rate and increased (50%) hot-water-soluble carbohydrates in the soil at the highest rate. No effects were observed on soil microbial biomass C (114-205 mg kg) and activity (5-8 mg CO-C kg d) or on corn grain yields (6349-7233 kg ha). Controlled land application seems to be a viable alternative for landfill leachate management, but NO leaching, NH volatilization, and accumulation of salinizing ions must be monitored in the long term to prevent environmental degradation.

Three-band decomposition analysis of wall shear stress in pulsatile flows.

Space-time patterns of wall shear stress (WSS) resulting from the numerical simulation of pulsating hemodynamic flows in semicoronal domains are analyzed, in the case of both regular semicoronal domains and semicoronal domains with bumpy insertions, mimicking aneurysm-like geometries. A new family of cardiovascular risk indicators, which we name three-band diagrams (TBDs), are introduced, as a sensible generalization of the two standard indicators, i.e., the time-averaged WSS and the oscillatory shear index. TBDs provide a handy access to additional information contained in the dynamic structure of the WSS signal as a function of the physiological risk threshold, thereby allowing a quick visual assessment of the risk sensitivity to individual fluctuations of the physiological risk thresholds. Due to its generality, TBD analysis is expected to prove useful for a wide host of applications in science, engineering, and medicine, where risk assessment plays a central role.

Heat transfer in Fitzhugh-Nagumo models.

An extended FitzHugh-Nagumo model coupled with dynamical heat transfer in tissue, as described by a bioheat equation, is derived and confronted with experiments. The main outcome of this analysis is that traveling pulses and spiral waves of electric activity produce temperature variations on the order of tens of mu degrees C. In particular, the model predicts that a spiral wave's tip, heating the surrounding medium as a consequence of the Joule effect, leads to characteristic hot spots. This process could possibly be used to have a direct visualization of the tip's position by using thermal detectors.

Viscoelastic Fitzhugh-Nagumo models.

An extended Fitzhugh-Nagumo model including linear viscoelasticity is derived in general and studied in detail in the one-dimensional case. The equations of the theory are numerically integrated in two situations: (i) a free insulated fiber activated by an initial Gaussian distribution of action potential, and (ii) a clamped fiber stimulated by two counter phased currents, located at both ends of the space domain. The former case accounts for a description of the physiological experiments on biological samples in which a fiber contracts because of the spread of action potential, and then relaxes. The latter case, instead, is introduced to extend recent models discussing a strongly electrically stimulated fiber so that nodal structures associated on quasistanding waves are produced. Results are qualitatively in agreement with physiological behavior of cardiac fibers. Modifications induced on the action potential of a standard Fitzhugh-Nagumo model appear to be very small even when strong external electric stimulations are activated. On the other hand, elastic backreaction is evident in the model.

Species identification and confirmation of human and animal cell lines: a PCR-based method.

Misidentification and cross-contamination of cell lines are major problems of cell cultures that can make scientific results and their reproducibility unreliable. This paper describes a PCR-based method for easily identifying or confirming the species of origin of cell lines by using a panel of oligonucleotides specific for the nine animal species most common in cell culture laboratories. A panel of 35 human and animal cell lines, whose species of origin were previously confirmed by isoenzyme assay, was studied with nine species-specific primer pairs that specifically anneal to DNA sequences codifying for human, cat, dog, mouse, rat, horse, rabbit, African Green monkey cytochrome c oxidase subunit I (cox I), and one primer pair specific for the cytochrome b gene of Chinese hamster. The amplified fragments were analyzed by electrophoresis in ethidium bromide-stained 2% agarose gels. The method is simple, rapid, highly sensitive, and useful for routinely monitoring the species identity of cell cultures.

HLA-A, -B, -C genotyping and expression in human nonlymphoid tumor cell lines.

A combination of molecular genotyping and protein biochemistry methods was used to assess the HLA-A, -B, -C genotyping and expression of six tumor cell lines. Four cell lines had been previously HLA typed by conventional serologic methods. Two could not be typed by serology because deficient in the surface expression of HLA-A, -B, -C molecules. As shown herein, all the 25 alleles carried by the six tested cell lines were typed at the DNA level. In addition, discrepancies between the previous serologic and the present DNA typing results were detected in 9 of the 21 tested serologic specificities. Typing at the protein level by isoelectric focusing and allele-specific monoclonal antibodies confirmed the DNA typing data. Our results exemplify the limits of the serologic typing procedures and demonstrate that molecular methods are highly desirable to conduct functional experiments and identify HLA losses in neoplastic cells at single allele level.

HLA-C heavy chains free of beta2-microglobulin: distribution in normal tissues and neoplastic lesions of non-lymphoid origin and interferon-gamma responsiveness.

Lacking monospecific antibodies to HLA-C, the expression and synthesis of these molecules have been difficult to evaluate. Using biochemical and flow cytometry approaches, the present report demonstrates that the reactivity of the murine monoclonal antibody L31 is restricted to naturally occurring HLA-C (HLA-Cw1 through -Cw8), HLA-B8 and HLA-B51 heavy chains not associated with beta2-microglobin (beta2m). This is due to two properties of HLA-C heavy chains: (a) they share the L31 epitope which distinguishes them from all the HLA-A and most HLA-B molecules; (b) they accumulate intracellularly, in a beta2m-free form, in much greater amounts than most L31-reacting HLA-B heavy chains. On the basis of this restricted reactivity, a representative panel of normal and neoplastic human tissues and cells derived from HLA-B8- B51- individuals was selected and employed to assess the tissue distribution, surface expression and IFN-gamma responsiveness of beta2m-free HLA-C heavy chains. At variance from antibody W6/32 to beta2m-associated heavy chains, L31 stains normal and neoplastic tissues with a ground-glass pattern and weakly binds to the surface of viable cells, even after treatment with interferon gamma (IFN-gamma). Thus, beta2m-free HLA-C heavy chains are, for the most part, located intracellularly. In spite of their distinct cellular localization, L31- and W6/32-reacting molecules have an overlapping tissue distribution, undergo concordant changes upon transformation and are upregulated in their synthesis by IFN-gamma to a similar extent. These observations demonstrate a coordinate regulation of HLA-C with HLA-A and -B molecules. In addition, they indicate that the assembly of HLA-C is impaired in most body districts and IFN-gamma is unable to completely reverse this impairment. The present results are consistent with a low surface expression of HLA-C and with a privileged role of these molecules in signaling class I loss to cytotoxic effectors in pathological conditions.

Interaction of carboplatin with carrier human erythrocytes.

The antineoplastic drug Carboplatin (CBDCA) was encapsulated in human erythrocytes by means of transient hypotonic hemolysis, followed by isotonic resealing. Up to 5 mg/ml of packed cells could be entrapped, with about 70% cell recovery. In vitro incubation of the CBDCA-loaded erythrocytes in autologous plasma caused a very slow release of the drug from the cells (12% approximately in 3 h). The encapsulation conditions, performed at a low hematocrit, in order to obtain high amounts of the drug inside the carriers, impaired the metabolic properties of the loaded erythrocytes significantly. In particular, an almost complete disappearance of GSH was observed. Analysis of the intraerythrocytic metabolism of CBDCA showed that, in spite of its relatively high stability in aqueous solutions, in hemolysates and in the loaded erythrocytes a significant percentage of CBDCA is rapidly converted to other species that still retain an antiproliferative activity in vitro. This fast conversion could be extensively inhibited by previous conversion of oxyhemoglobin to methemoglobin or carbomonoxyhemoglobin, suggesting an important role of heme iron in this process. Encapsulation of CBDCA in selectively targeted human erythrocytes may represent a therapeutic strategy for increasing the drug concentration in specific organs, notably liver.

[Association between ABO blood groups and gallbladder calculi: a dissenting opinion]. / Associazione gruppi sanguigni ABO e calcolosi della colecisti: un'opinione contraria.

A group of 174 hospital patients was studied to discover the incidence of ABO blood groups in comparison, with a similar analysis of a representative sample (1872 people) of the Amiata Community as a whole. Though this type of sampling is open to criticism, it is still felt that there is no statistical proof that one or more of these blood groups is more prone to gall stones, at least in Amiata.

[Reference values for the serum concentration of apolipoproteins A and B, the A/B ratio and cholesterol-HDL. Evaluation in a clinically healthy population in Amiata (Grosseto)]. / Studio dei valori di riferimento della concentrazione sierica delle apolipoproteine A E B, del rapporto A/B E del colesterolo-HDL. Valutazione in una popolazione clinicamente sana dell'amiata, versante grossetano.

The authors have studied the distribution of the Apolipoproteins A and B, the Apo A/B ratio and the HDL-cholesterol on healthy people, according to sex and age, in order to fix the reference values, considering that the literature is poor and the opinions are different.