Residues characterisation from the fluidised bed combustion of East London's solid recovered fuel

Waste thermal treatment in Europe is moving towards the utilisation of the combustible output of mechanical, biological treatment (MBT) plants. The standardisation of solid recovered fuels (SRF) is expected to support this trend and increase the amount of the generated combustion residues. In this work, the residues and especially the fly ashes from the fluidised bed combustion (FBC) of East London's NCV 3, Cl 2, and Hg 1 class SRF, are characterised. The following toxicity indicators have been studied: leachable chlorine, organochlorides expressed as pentachlorobenzene and hexachlorobenzene, and the heavy metals Cu, Cr, Cd, Zn, Ni, and Pb. Furthermore the mineralogical pattern of the ashes has been studied by means of XRD and SEM-EDS. The results suggest that these SRF derived ashes have significantly lower quantities of Cu, Cd, Pb, Zn, leachable Cl, and organochlorides when compared to other literature values from traditional waste thermal treatment applications. This fact highlights the importance of modern separation technologies employed in MBT plants for the removal of components rich in metals and chlorine from the combustible output fraction of SRF resulting to less hazardous residues.

An application of mixture distributions in modelization of length of hospital stay

Length of hospital stay (LOS) is an important indicator of the hospital activity and management of health care. The skewness exhibited by this variable poses problems in statistical modeling. The aim of this work is to model the variable LOS within diagnosis-related groups (DRG) through finite mixtures of distributions. A mixture of the union of Gamma, Weibull and Lognormal families is used in the model, instead of a mixture of a unique distribution family. Some theoretical questions regarding the model, such as the identifiability and study of asymptotic properties of ML estimators, are analyzed. The EM algorithm is proposed for performing these estimators. Finally, this new proposed model is illustrated by using data from different DRGs.

Single-walled carbon nanotubes deposited on surface electrodes to improve interface impedance

A suspension of commercially available single-walled carbon nanotubes (SWNTs) is directly deposited onto a platinum multielectrode array surface. This is a novel and easy method to reduce interface impedance values which can be used instead of electromodified electrodes. This paper shows that this deposition method is a useful technique for the modification of patterned electrodes ranging in the micro scale. A thorough comparison between the common and well-known black platinum versus SWNTs, as interface material for different electrode areas, has been carried out. SWNTs-based electrodes smaller than 40 microm Ø improve the interface impedance values when compared to black platinum-modified electrodes of the same size. The best results can be found for the 10 microm Ø, which improves the electrode resistance by 25% in comparison with the black platinum ones. The lower resistance and higher capacitance calculated for the 40 microm diameter SWNTs-based electrode, in comparison with black platinum, also evidence a clear increment of the effective area, which is directly related to the impedance decrease.

Adult stem cells: perspectives for therapeutic applications

The use of adult stem cells in tissue regeneration appears to be a powerful research tool, due to the intrinsic characteristics of these cells, i.e., self-renewal and unlimited capacity for proliferation. In particular, mesenchymal stem cells (MSCs) obtained from bone marrow or peripheral blood can be easily isolated, cultivated, propagated and can be differentiated into several specialized cell types thanks to their plasticity. Among these cells, MSCs can evolve into cardiac cell lineages. Since heart damage leads to the irreversible loss of cardiac function, cell transplantation could be a potential therapy for heart injury. Our laboratory has focused on the purification and expansion of rat and sheep MSCs, their differentiation into cardiomyocytes and their characterisation. Numerous results indicate that MSCs could be promising for therapy, however we need to better understand the biology of stem cells to improve methods for delivery and/or pharmacological activation. These techniques can indeed track engrafted cells and systems to guarantee their safe use.

Early and late complications among 15 victims exposed to indoor fire and smoke inhalation

AIM

To evaluate early and late complications among victims exposed to indoor fire and smoke inhalation.

METHOD

An observational, descriptive and prospective longitudinal study of 15 victims of smoke inhalation admitted to the intensive care unit.

RESULTS

Although without significant burns, 13 of the victims were unconscious, with airway injury, abnormal temperature and hypokalaemia, and underwent mechanical ventilation. Initial carbon monoxide concentration averaged 20.4+/-8.3%, dropping to 3.9+/-3.3% 4h later. On the 1st day, two victims recovered and were transferred, and another two died. Creatine kinase levels (2594+/-2455 U/l) correlated with duration of intensive care. Of the remaining 11 patients, 10 had early pneumonia. Steroid treatment was initiated for four patients receiving prolonged mechanical ventilation, because of persistent fever and dry cough without evidence of infection.

CONCLUSIONS

Mortality and systemic involvement were related to burn of the upper airway and contact with combustion products. Initial creatine kinase levels emerged as a prognostic marker of injury severity. Bronchoscopy was useful in grading airway injury and obtaining bronchoalveolar culture. Corticosteroids were effective, after the acute phase, in treating non-infectious pulmonary complications.

Oral and intravenous administration of nimesulide in the horse: rational dosage regimen from pharmacokinetic and pharmacodynamic data

REASONS FOR PERFORMING STUDY

The selective COX-2-inhibitor nimesulide is used extra-label in equine veterinary practice as an anti-inflammatory agent. However, there are no data on which to base the rational use of the drug in this species.

OBJECTIVES

To determine the effective COX selectivity of nimesulide in the horse, and suggest a suitable dosing schedule.

METHODS

The pharmacokinetics of nimesulide in the horse after oral administration (1 mg/kg bwt), and oral and i.v. administration (1.5 mg/kg bwt) were investigated, effects of feeding status on bioavailability determined, and plasma protein binding of the drug and its principal metabolites measured. Compartmental and noncompartmental pharmacokinetic analyses were performed. The plasma concentration-time profile was used, together with in vitro literature data on nimesulide inhibition of COX isoforms, to determine the effective COX selectivity of nimesulide in the horse, and suggest a suitable dosing schedule.

RESULTS AND CONCLUSIONS

The findings suggest that 1.5 mg/kg bwt may produce adequate clinical effects, and the dosing interval should be 12-24 h depending on condition severity. However, at that dose, the concentration in the animal exceeds the in vitro IC50 for both isoforms, so that COX-1/COX-2 selectivity is lost and side-effects due to COX-1 inhibition are a possibility. Nimesulide should therefore be used with caution in equine clinical practice.

Short Communication: Antimicrobial Drug Susceptibility of Staphylococcus aureus from Subclinical Bovine Mastitis in Italy

The antimicrobial susceptibility of 68 Staphylococcus aureus isolates collected during 2004 from milk of cows affected by subclinical mastitis was examined. The antimicrobial agents tested were the beta-lactams, penicillin G, amoxicillin, ampicillin, cloxacillin, amoxicillin + clavulanate, cephalonium, and cefoperazone; and other drugs including lincomycin, oxytetracycline, doxycycline, and kanamycin. Minimum inhibitory concentrations recorded show that only certain beta-lactamase-resistant penicillins (specifically cloxacillin) or penicillin combinations (amoxicillin + clavulanate) were consistently effective against Staph. aureus, whereas the other beta-lactam derivatives and drugs from other pharmacological groups were either moderately effective or ineffective. Thus, beta-lactamase-resistant penicillins are to be considered the antimicrobial agents of choice for treatment of bovine mastitis resulting from infection by Staph. aureus.

Gastrointestinal transit, release and plasma pharmacokinetics of a new oral budesonide formulation

AIMS

The aims of the study were to: (1) evaluate the gastrointestinal transit, release and absorption of budesonide from tablets with a new multimatrix formulation (MMX) designed to release the drug throughout the whole colon, and (2) assess the influence of food on budesonide bioavailability.

METHODS

Two phase I studies, each comprising 12 healthy males, were performed. Gastrointestinal transit of (153)Sm-labelled tablets containing 9 mg budesonide was evaluated by means of pharmaco-scintigraphy. The effect of food was tested by comparing plasma pharmacokinetics after intake of a high fat and high calorie breakfast with fasting controls.

RESULTS

(153)Sm-labelled tablets reached the ascending colon after a mean +/- SD 9.8 +/- 6.9 h. Initial tablet disintegration was observed in the ileum in 42% and the ascending and transverse colon in 33% of subjects. Ninety-six per cent of the dose was absorbed into the systemic circulation during passage through the whole colon including the sigmoid. Food significantly decreased C(max) values from 1429 +/- 1014 to 1040 +/- 601 pg mL(-1) (P = 0.028) and AUC values from 14 814 +/- 11 254 to 13 486 +/- 9369 pg h(-1) mL(-1) (P = 0.008). Mean residence time and t(max) increased by 12-29%. There was no drug accumulation after 1 week of once daily oral administration of budesomide.

CONCLUSIONS

MMX-budesonide tablets appear suitable for targeted colonic drug delivery. Transit parameters and low systemic bioavailability warrant further studies with the new formulation.

Flumequine in the goat: pharmacokinetics after intravenous and intramuscular administration

The pharmacokinetics of flumequine, administered intravenously and intramuscularly at a single dose of 20 mg/kg, was investigated in healthy goats. After intravenous injection, flumequine distributed rapidly (t1/2alpha = 0.87+/-0.15 h) but was eliminated slowly (t1/2beta = 7.12+/-1.27 h); mean clearance (Cl) and volume of distribution (Vdss) were 0.32+/-0.03 (L/(h x kg) and 1.22+/-029 (L/kg), respectively. After intramuscular administration, the peakserum concentration (Cmax = 7.40+/-0.5 microg/ml) was reached in about 1.5 h (Tmax) and bioavailability was about 93%. Estimated flumequine serum levels following repeated intramuscular administration of the aqueous suspension used in the study (7.23+/-0.7 microg/ml and 4.82+/-0.47 microg/ml at intervals of 8 and 12 h, respectively) indicated that to maintain serum levels above MIC values for susceptible bacteria a dosage regimen of 20 mg/kg every 12 h is necessary by the intramuscular route.

Coronally advanced flap with or without enamel matrix derivative for root coverage: a 2-year study

AIM

The purpose of this study was to assess the ability of enamel matrix derivative (EMD) to improve root coverage with a coronally advanced flap (CAF) during a 2-year follow-up.

METHODS

Fifteen patients each with two single and similar bilateral Miller Class I or II gingival recessions (30 recessions) were selected. Each recession was randomly assigned to the test group (CAF+EMD) or the control group (CAF only). Clinical parameters recorded at baseline and at 6, 12 and 24 months were recession depth (R), recession width (WR), probing depth (PD), clinical attachment level (CAL) and keratinized tissue (KT).

RESULTS

Reduction of R resulted in a significant CAL gain in both groups, whereas PD was not altered. In the test group, R decreased from 4.07 mm (SD+/-0.59) at baseline to 0.47 mm (SD+/-0.74) at 24 months, corresponding to a mean root coverage (MRC) of 90.67%, whereas in the control group R shrank from 4.13 mm (SD+/-0.74) at baseline to 0.60 mm (SD+/-0.83) at 24 months (MRC=86.67%). Complete root coverage was achieved at 24 months in 73.33% and 60% of the two groups. A significant KT increase was observed in both groups.

CONCLUSIONS

Root coverage outcomes were similar in both groups and no statistically significant differences were found at all between them. Hence, the additional use of EMD to CAF is not justified for clinical benefits of root coverage, but as an attempt of achieving periodontal regeneration rather than repair.

Pharmacodynamics and pharmacokinetics of flumequine in pigs after single intravenous and intramuscular administration

The pharmacokinetics and intramuscular (IM) bioavailability of flumequine (15 mgkg(-1)) were investigated in healthy pigs and the findings related to published minimal inhibitory concentrations (MICs) for susceptible bacteria of animal origin, and to experimentally determined MICs for susceptible strains of porcine origin. We found MICs for Escherichia coli, Salmonella spp., Pasteurella spp. and Bordetella spp. in the range 0.5 to >64 microg mL(-1) isolated from infected pigs in the Forli area of Italy; only the Pasteurella multocida strains were sensitive (MIC(90)=0.5 microg mL(-1)). After intravenous (IV) injection, flumequine was slowly distributed and eliminated (t(1/2lambda(1))1.40+/-0.16 h and t(1/2lambda(2))6.35+/-1.69 h). The distribution volume at steady state (V(dss)) was 752.59+/-84.03 mL kg(-1) and clearance (Cl(B)) was 237.19+/-17.88 mL kg(-1)h(-1). After IM administration, peak serum concentration (4.99+/-0.92 microg mL(-1)) was reached between the 2nd and the 3rd hour. The results on MIC of isolated bacteria, although only indicative, suggest that the efficacy of flumequine on Gram-negative bacteria may be impaired by the emergence of less sensitive or resistant strains.

Activation of brain estrogen receptors in mice lactating from mothers exposed to DDT

The insecticide dichlorodiphenyltrichloroethane (DDT) interferes with physiological endocrine processes modulating estrogens receptor activity. Most of the data describing the DDT mechanism of action have been collected in vitro or in reproductive tissues in vivo. Here we use a new transgenic mouse model to investigate the DDT effects on estrogens receptor activation in vivo in non-reproductive tissues. In particular, we demonstrate that DDT is able to activate estrogen receptors in the brain and the liver of adult mice after acute administration, and it is active in lactating mice when accumulated in the mother's milk. Furthermore, we demonstrate that the acute administration of DDT activates estrogen receptors with a different kinetics with respect to 17beta-estradiol. Experiments with a breast cancer cell line engineered to express luciferase under the transcriptional control of activated estrogen receptors reveal that the microsomal metabolization of DDT is required for its full activity on estrogen receptors. Taken together these data lead to hypothesize that the delayed DDT time course on estrogen receptor activation in vivo might be due to a necessary step of metabolism of the compound.

Target-specific action of organochlorine compounds in reproductive and nonreproductive tissues of estrogen-reporter male mice

Organochlorines are lipophylic molecules that accumulate in the fat where they remain for years. During weight loss, they are mobilized and their concentration increases in blood. The present work tests, in transgenic estrogen-reporter mice (ERE-tK-LUC), whether this increase is sufficient to modulate the estrogen receptors (ERs) in the whole body. Three weak estrogens were studied: p,p'DDT [1,1,1-trichloro2,2-bis(p-chlorophenyl) ethane], p,p'DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene], and betaBHC [beta-benzene-hexachloride]. Dose-dependent analysis of reporter expression (luciferase) were performed in tissues of acutely treated mice. A body map of ER activation was obtained. All these chemicals modulated the reporter, although with a different efficiency and depending upon the tissue analyzed. Induction was confirmed in the liver by determining the expression of the endogenous progesterone receptor (PR) gene, at the dose and time point at which the luciferase gene was maximally induced. After experimental accumulation in the fat tissue, followed by a 48-h period of fasting, we tested whether these compounds could be mobilized to reach sufficient levels to activate the ERs in selected reproductive and nonreproductive tissues (testicle, prostate, liver, and lung). This experimental setting produced results that were different than those obtained following acute treatments. In loaded mice, fasting induced betaBHC mobilization resulted in strong ER activation in the liver and the lung, which was blocked by ICI-182780. p,p'DDT mobilization had no effect in these tissues, but it acted efficiently in the prostate and testis. betaBHC inhibited the ERE-mediated reporter in the testicle and induced the reporter in the prostate. In this tissue, betaBHC action was not inhibited by the anti-estrogen ICI-182780. During fasting, betaBHC, p,p'DDT, and metabolite p,p'DDE increased in blood concentration, from 2.25 +/- 0.25, 0.51 +/- 0.09, and 0.38 +/- 0.06 microg/ml to 8.24 +/- 0.95, 4.52 +/- 0.68, and 5.06 +/- 0.57 microg/ml, respectively. The effect produced by these organochlorines in the liver correlates with the modulation of the ERalpha protein. We conclude that these organochlorines modulate differently the expression of estrogen-regulated genes in male mice. Their effect is tissue- and compound-specific and is dependent on the energetic balance.

Whole body action of xenoestrogens with different chemical structures in estrogen reporter male mice

The present work tested the estrogenic activity of three weak environmental estrogens p,p'DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane], p,p'DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] and betaBHC [beta-benzene-hexachloride] in the transgenic estrogen-reporter mouse model (ERE-tK-LUC). By a time dependent analysis of the transgenic reporter expression (luciferase), we showed that all these chemicals modulated the estrogen receptors (ERs) in the whole body, although with a different efficacy and depending upon the tissue analyzed. Peak activity was registered at 16 h of treatment with 5000 microg/kg of each compound. Organochlorines are lipophylic molecules that accumulate in fat. During weight loss they are mobilized and their concentration increases in blood. We tested whether after experimental accumulation in fat tissue, followed by a 48 h period of fasting, these compounds could be modulated to reach sufficient levels to activate the ERs in target tissues. This experimental setting produced results that were different from those obtained following acute treatments. In loaded mice, fasting induced betaBHC mobilization resulted in strong ER activation in the liver, lung, eye, cerebellum, hypothalamus and cortex. p,p'DDT mobilization had no effect in these tissues, but efficiently acted in the testis, where, on the contrary, betaBHC inhibited reporter expression. During fasting, betaBHC, p,p'DDT and the metabolite p,p'DDE increased in blood concentration, from 2.7 +/- 0.36, 0.65 +/- 0.01 and 0.48 +/- 0.06 microg/ml to 9.51 +/- 1.1, 4.98 +/- 0.77 and 6.0 +/- 0.71 microg/ml, respectively. We conclude that these organochlorines modulate differently the expression of estrogen regulated genes in a tissue- and compound-specific manner and that their action is dependent on the energy balance. Moreover, we show that this mouse model is suitable to detect the estrogenic activity of chemicals with variable structures such as alkyl phenols and polychlorobiphenyls.

Altered epigenetic signals in human disease

The genetic information of almost all eukaryotic cells is stored in chromatin. In cancer cells, alterations in chromatin organization or in its epigenetic marks occur frequently. Among these are changes in the patterns of DNA and histone methylation. Using Acute Promyelocytic Leukemia as model system we could demonstrate a direct correlation of epigenetic events induced by the driving oncogene product PML-RARalpha and cancer progression. Several of the enzymes ultimately responsible for these events can be inhibited by small compound inhibitors and thus can serve as targets in cancer therapy. In this article, we review the role of DNA methylation, histone methylation and chromatin alterations in human diseases. A picture is emerging in which these epigenetic signals "cross-talk" and are implicated in the physiological and pathological spreading of gene silencing.

Epigenetic gene silencing in acute promyelocytic leukemia

The recent explosion in our knowledge of how chromatin organization modulates gene transcription has highlighted the importance of epigenetic mechanisms in the initiation and progression of human cancer. These epigenetic changes--in particular, aberrant promoter hypermethylation that is associated with inappropriate gene silencing--affect virtually every step in tumor progression. Intriguingly, methylation patterns are severely altered in tumors, with an overall hypomethylation of the genome and hypermethylation of islands of CpGs clusters within specific DNA regions. Though overexpression of DNA methyltransferases (DNMTs) has been proposed to be a mechanism for aberrant genome methylation, it does not explain the specific regional hypermethylation in cancer cells. We have analyzed the role of chromatin modifying activities in cell transformation using acute promyelocytic leukemia as a model system. This disease is caused by expression of the PML-RARalpha fusion protein, thus offering the opportunity of studying the mechanisms of leukemogenesis through molecular investigation of the activity of the directly transforming protein. Recent evidence suggests that PML-RARalpha as well as other leukemia-associated fusion proteins induce changes in the chromatin structure. Specifically, aberrant recruitment of different chromatin modifying enzymes to specific promoters induces DNA hypermethylation and heterochromatin formation, which consequentially leads to the transcriptional silencing of that genes. Importantly, these epigenetic modifications were found to contribute to the leukemogenic potential of PML-RARalpha. These observations suggest that epigenetic alterations could actively contribute to the development of APL and other hyperproliferative diseases.

Minimally invasive silicon probe for electrical impedance measurements in small animals

It is commonly accepted that electrical impedance provides relevant information about the physiological condition of living tissues. Currently, impedance measurements are performed with relatively large electrodes not suitable for studies in small animals due to their poor spatial resolution and to the damage that they cause to the tissue. A minimally invasive needle shaped probe for electrical impedance measurements of living tissues is presented in this paper. This micro-probe consists of four square platinum electrodes (300 microm x 300 microm) on a silicon substrate (9 mm x 0.6 mm x 0.5 mm) and has been fabricated by using standard Si microelectronic techniques. The electrodes are not equally spaced in order to optimise the signal strength and the spatial resolution. Characterisation data obtained indicate that these probes provide high spatial resolution (measurement radius <4 mm) with a useful wide frequency band going from 100 Hz to 100 kHz. A series of in vivo experiments in rat kidneys subjected to ischemia was performed to demonstrate the feasibility of the probes and the measurement system. The impedance modulus and phase were measured at 1 kHz since this frequency is sufficiently low to permit the study of the extracellular medium. The extracellular pH and K+ were also simultaneously measured by using commercial miniaturised Ion Selective Electrodes. The induced ischemia period (45 min) resulted in significant changes of all measured parameters (Delta/Z/ approximately 65%; DeltapH approximately 0.8; DeltaK+ approximately 30 mM).

Pharmacodynamics and pharmacokinetics of cefoperazone and cefamandole in dogs following single dose intravenous and intramuscular administration

The pharmacokinetics and intramuscular (i.m.) bioavailability of cefoperazone and cefamandole (20mg/kg) were investigated in dogs and the findings related to minimal inhibitory concentrations (MICs) for 90 bacterial strains isolated clinically from dogs. The MICs of cefamandole for Staphylococcus intermedius (MIC(90) 0.125 microg/mL) were lower than those of cefoperazone (MIC(90) 0.5 micro/mL) although the latter was more effective against Escherichia coli strains (MIC(90) 2.0 microg/mL vs. 4.0 microg/mL). The pharmacokinetics of the drugs after intravenous administrations were similar: a rapid distribution phase was followed by a slower elimination phase (t((1/2)lambda2) 84.0+/-21.3 min for cefoperazone and 81.4+/-9.7 min for cefamandole). The apparent volume of distribution and body clearance were 0.233 L/kg and 1.96 mL/kg/min for cefoperazone, 0.190 L/kg and 1.76 mL/kg/min for cefamandole. After i.m. administration the bioavailability and peak serum concentration of cefamandole (85.1+/-13.5% and 35.9+/-5.4 microg/mL) were significantly higher than cefoperazone (41.4+/-7.1% and 24.5+/-3.0 micog/mL), but not the serum half-lives (t(1/2el) 134.3+/-12.6 min for cefoperazone and 145.4+/-12.3 min for cefamandole). The time above MIC(90) indicated that cefamandole can be administered once daily to dogs for the treatment of staphylococcal infections (T>MIC for S. intermedius 23.8+/-0.3 and for Staphylococcus aureus 21.6+/-0.6h).

Multiparametric monitoring of ischemia-reperfusion in rat kidney: effect of ischemic preconditioning

BACKGROUND

Microelectrode technology is a promising tool for monitoring kidney ischemia and the changes induced by its therapeutic management. Ischemic preconditioning, that is, brief ischemic periods before sustained ischemia, has been shown to protect several organs, including the kidney, from ischemia-reperfusion injury. We tested whether the effect of preconditioning could be appraised by real-time measurement of parameters representative of tissue hypoxia.

METHODS

In a sample of pentobarbital-anesthetized and mechanically ventilated rats, we studied the effect of renal ischemic preconditioning (10-min ischemia and 10-min reflow interval) on subsequent ischemia-reperfusion (45 min and 60 min). Renal tissue electrical impedance, extracellular pH, and potassium concentration [K+] were measured continuously by implanted microelectrodes.

RESULTS

Ischemia induced an early, rapid rise in extracellular potassium and impedance module, followed by a phase of slower increase, whereas pH decreased rapidly, reaching a plateau. Preconditioning treatment did not cause significant changes in interstitial pH and [K+] but increased ischemic tissue impedance. During reperfusion, the three variables recovered progressively; however, after a decline, electrical impedance showed a clear postischemic increase. This rise was suppressed by preconditioning.

CONCLUSIONS

Real-time measurement of any of the three parameters showed capability for early detection of ischemia. In contrast with findings in myocardial tissue, preconditioning in the kidney did not increase potassium cell loss during ischemia or improve ischemic acidosis or tissue impedance. Electrical impedance increased for a second time during reperfusion, indicating the presence of a postischemic cellular edema; concealing this episode was the most noticeable effect of the preconditioning treatment.