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R Marotta

Publications and source records attributed to R Marotta.

At least 19 recordsLinked to original sources
PubMed2005

Estimation of biodegradation kinetic constants for aromatic derivates through aerobic batch experiments.

The kinetics of aerobic biodegradation were studied for 20 aromatic species by using sludges taken from a municipal sewage treatment plant. The reproducibility of the results is tested with respect to the period of collection of the sludges and the wastewater treatment plant where they were taken. The comparison of kinetic constants estimated for investigated chemicals allows evaluation of the effect on the reactivity due to the presence of single groups (i.e. -OH, -CH3, -Cl, -NO2) into the aromatic structures. The search for easy structure-reactivity relations is also attempted by using some group contributing methods.

Bacteria, Aerobic↗
PubMed2004

(S)-Nitroxycarnitine nitrate production from (S)-carnitine by using acetic anhydride/nitric acid/acetic acid mixtures: safety assessment.

The present work aims at assessing both thermodynamic and kinetic parameters of the esterification process of the (S)-carnitine, using calorimetric techniques. The use of the system acetic anhydride/nitric acid/acetic acid as esterifying agent and the explosive behaviour of nitric esters lead to safety considerations that have been investigated by hypothesizing some common process deviations. In particular, it has been investigated in adiabatic conditions both the batch addition of acetic anhydride and the effect of an initial temperature higher than those required by the process.

Acetic Acid↗
PubMed2004

Effects of advanced oxidation processes (AOPs) on the toxicity of a mixture of pharmaceuticals.

The possibility of applying main AOP techniques, namely ozonation, H2O2/UV photolysis and TiO2 photocatalysis to provide a significant reduction of toxicity of pharmaceutical mixtures has been evaluated. For the preparation of the mixture six pharmaceuticals were chosen among those found at highest concentrations in Sewage Treatment Plant effluents, namely carbamazepine, clofibric acid, diclofenac, sulfamethoxazole, ofloxacin and propranolol. The blue-green alga Synechococcus leopoliensis and the rotifer Brachyonus calyciflorus were utilised to assess the toxicity of the mixtures after AOP treatments. All the toxicity tests were performed using chronic standardized bioassays. The best results were obtained with ozonation. With this type of treatment a complete removal of mixture toxicity on S. leopolensis was obtained even after the shortest time of application (1 min). The ozonation treatment leads also to removal of all the pharmaceutical mixture toxicity on B. calyciflorus, by applying the oxidizing agent for at least for 2 minutes.

Animals↗
PubMed2002

The double sperm line in Isochaetides (Annelida, Clitellata, Tubificidae).

Sperm morphology and spermatogenesis were examined in the oligochaete annelid Isochaetides arenarius, a species belonging to the subfamily Tubificinae inhabiting the sediments of Lake Baikal. As all tubificines, Isochaetides produces two types of spermatozoa, named eusperm and parasperm. The eusperm are the fertilizing male gametes and consist, in sequence, of an acrosome, a nucleus, a mitochondrial mid-piece, and a tail. The parasperm have the same general architecture, but differ in cytological details: the acrosome is shorter, devoid of a perforatorium, and the acrosome vesicle has a different, simpler, shape. The nucleus is much shorter and rectilinear (the eusperm nucleus is twisted). The mid-piece mitochondria are less numerous but their overall volume is larger. The flagellum has a plasma membrane largely separated from the axoneme, and is devoid of glycogen granules. After mating, the two sperm types gather in the spermathecae to form spermatozeugmata; in these structures the parasperm form an external sheath involving the centrally located eusperm and their tails are connected by conspicuous septate junctions. Parasperm nuclei are produced through a process of fragmentation of the 'spermatocytes', whereas the flagellar basal bodies are produced by a process similar to that giving rise to basal bodies in ciliated epithelia.

Acrosome↗
PubMed2002

CD45 fraction bone marrow cells as potential delivery vehicles for genetically corrected dystrophin loci.

Targeted correction of mutations in muscle can be delivered by direct i.m. injection of corrective DNA to the dystrophic muscle or by autologous injection of cells that have been genetically corrected after isolation from the individual with the dystrophic muscle. The successful application of chimeraplasty and short fragment homologous replacement to correct the exon 23 nonsense mdx transition at the mouse dys locus has opened up the possibility that with further development, targeted gene correction may have some future application for the treatment of muscular dystrophies. In vitro, application of targeted gene correction at the mdx dys locus results in better correction efficiencies than when applied directly to dystrophic muscle. This suggests that at least for the time being, a strategy involving ex vivo correction may be advantageous over a direct approach for delivery of gene correction to dystrophic muscle. This, particularly in view of recent developments indicating that bone-marrow-derived cells are able to systemically remodel dystrophic muscle, whilst penetration of DNA introduced to muscle is limited to individually injected muscles. Application of targeted gene correction to Duchenne dystrophy needs to account for the fact that about 65% of Duchenne muscular dystrophy cases involve large frame-shift deletion of gene sequence at the dys locus. Traditionally, whilst targeted gene correction is able to restore point mutations entirely, it remains to be seen as to whether a strategy for the 'correction' of frame shift deletions may be engineered successfully. This communication discusses the possibility of applying targeted gene correction to dystrophic muscle in Duchenne dystrophy.

Animals↗
PubMed2001

Kinetic modeling of pyruvic acid ozonation in aqueous solutions catalyzed by Mn(II) and Mn(IV) ions.

The ozonation of pyruvic acid (2-ketopropionic acid) in aqueous solutions, catalyzed by Mn(II) and Mn(IV) ions, has been studied at three different pH values (pH = 1.1, 2.0 and 3.0). A mathematical model of the unsteady operation of the experimental reactor has been developed, which takes into account the reactions occurring in the liquid phase and the ozone mass transfer from the gas bubbles. Those reactions have been described with two alternative kinetic models, both made out of four elementary steps. The two kinetic models correlate the experimental data with a fair accuracy, respectively at the lowest and at the highest pH examined. In particular, at pH = 3.0, the ozonation results are inhibited by the acetate ions produced by the reaction itself. This effect has been correctly described in the terms of a complex formed with the low oxidation-state manganese, which successively reacts with the dissolved ozone.

Hydrogen-Ion Concentration↗
PubMed2000

A kinetic model for the degradation of benzothiazole by Fe3+-photo-assisted Fenton process in a completely mixed batch reactor.

The degradation of benzothiazole in aqueous solution by a photo-assisted Fenton reaction has been studied in a batch reactor in the pH range 2.0 - 3.2 and for H2O2 and Fe(III) concentrations respectively between 1.0 x 10(-3) - 1.5 x 10(-1) and 1.0 x 10(-6) - 4.0 x 10(-6) M. A kinetic model has been developed to predict the decay of benzothiazole at varying reaction conditions. The use of kinetic constants from the literature in the model allows to simulate the system behavior by taking into account the influence of pH, hydrogen peroxide, Fe(III) and sulfate concentrations and the ionic strength.

Benzothiazoles↗
PubMed1999

Ozonation of p-chlorophenol in aqueous solution.

The ozonation of p-chlorophenol (CHP) in aqueous solution has been studied in the pH range 2.0-8.0, in the presence of tert-butyl alcohol, which prevents the activation of the radical mechanism of oxidation. Results indicate that the pH influences the system reactivity and that only a partial chlorine release is observed for lengthy ozonation too, after the complete substrate disappearance. For adopted experimental conditions the oxidation process develops under a quasi-diffusional regime of absorption with reaction, a transition domain between kinetic and diffusional regimes in which ozone and dissolved substances react exclusively in the liquid film. A proper mathematical model has been developed and used to simulate the system behaviour

Chlorophenols↗
PubMed1999

The thermal decomposition of dimethoate.

The thermal decomposition of dimethoate, an organophosphorus pesticide, has been studied with the aim at assessing the reaction kinetics, the energy released during the process and the decomposition products. Dimethoate shows a marked tendency to undergo thermal decomposition at temperature higher than 369 K. A moderate pressure increase has been recorded at the end of all runs. Many thiophosphoric compounds have been identified among the decomposition products.

Biodegradation, Environmental↗
PubMed1999

Association of elevated levels of prothrombin fragment 1+2 and Arg506 to Gln mutation in patients with a history of ischemic stroke.

BACKGROUND: Recent findings have indicated the association between APC-resistance and cerebrovascular disease. These reports prompted us to investigate whether resistance to APC could be found in patients suffering from stroke. METHODS: Therefore, we studied APC-resistance in 50 young adults (< or =45 yrs) with a history of ischemic stroke. Eleven out of fifty cerebrovascular subjects showed APC-resistance, while 2 had PC deficiency and 3 PS deficiency. No deficiencies in the anticoagulant protein AT III and in fibrinolytic proteins were found. The family history demonstrated a distribution of APC-resistance compatible with dominant autosomal inheritance. The plasma concentration of prothrombin fragment 1+2 (F1+2), which is a marker of hypercoagulable states, was also measured in patients and family members of resistant subjects (n = 38). RESULTS: DNA analysis showed factor V R506Q mutation (Leiden mutation) in 11 patients and their relatives with poor response to activated protein C detected by APTT tests. Of 11 investigated subjects with APC-resistance, 9 were heterozygotes and 2, with the lowest APC-ratio values, were homozygotes for factor V mutation. Among 38 relatives, 22 showed a poor response to APC and according to the APC-ratio values, 18 were heterozygotes and 4 homozygotes for FV Leiden mutation. The mutation, in heterozygous form, was also found in 2% of our normal population (n = 100). The plasma concentration of F1+2 was significantly higher both in 11 individuals carrying the FV:Q506 mutation and in 39 patients without APC-resistance compared to that found in the control group. However, the patients with FV:Q506 mutation showed the highest values in F1+2. In the studied family members F1+2 plasma levels were within normal values. CONCLUSIONS: Our findings indicate a possible involvement of APC-resistance in the pathogenesis of cerebral thrombosis in young adults and agree with the hypothesis that individuals with APC-resistance have an imbalance between pro-and anti-coagulant forces leading to increased thrombin generation and a hypercoagulable state.

Adult↗
PubMed1997

Detection and characterization of an activity which aligns mesodermal cells into parallel arrays.

A cell line of mesodermal origin, FS9, was found to release a Cell Orienting Factor into its culture medium. In contrast with the random migration of controls, the orienting activity causes migrating mesenchymal cells to form an orderly "halo' surrounding tissue explants; individual cells and their cytoskeletons are elongated and parallel to each other but at right angle to the explant. No effect on the rate of cell movement was apparent. The orienting activity could be quantified by counting the number of cells found within strings radiating at right angles to a single tissue explant in the presence of FS9 conditioned medium or by using NIH image analysis. A dose dependent relationship with half maximal activity occurring at a 25% dilution of conditioned medium was observed. Cells that migrated randomly in the absence of conditioned medium became oriented within 4 h of exposure to 50% conditioned medium. Conversely, when the conditioned medium was removed, parallel alignment was rapidly lost. The orienting activity was found in conditioned media from a variety of mesodermal derivatives. Transformation of Balb/c 3T3 cells using EJ-ras oncogene led to augmented production of the activity. Furthermore, insulin was required in serum-free medium to support its production, Laminin, fibronectin and collagen and a range of pure cytokines, neither promoted nor inhibited orientation. Cell alignment was also unaffected by treatments which interfered with cell-substrate interactions and motility including the addition of the RGD peptide or anti-integrin beta 1 and beta 3 antibodies. A protein is likely to be involved since the activity was heat and trypsin sensitive and non-dialysable. The possibility is discussed that the orienting activity is a novel protein(s) which alters intercellular interactions to promote the formation of an aligned pattern by migrating mesenchymal cells.

3T3 Cells↗
PubMed1996

Promoter and expression studies on an Arabidopsis thaliana dehydrin gene.

A genomic clone of a group 2 lea/rab/dehydrin gene from Arabidopsis thaliana, Xero2/lti30, was cloned and sequenced. Promoter-GUS fusions were introduced into plants to analyse the promoter and determine expression patterns. Using root cultures, GUS expression was found to be moderately stimulated by abscisic acid (ABA), wounding, cold and dehydration. Results with an ABA-deficient mutant suggested endogenous ABA is required for these responses. Promoter deletion studies indicated multiple cis-acting elements are involved in the induction of the gene. GUS expression occurred in desiccated seeds, in all tissues of young seedlings and in roots (with the exception of the root tip), desiccated pollen grains, trichomes and the vascular tissues of leaves and stems in mature plants.

Abscisic Acid↗
PubMed1996

A double-blind trial of haloperidol, chlorpromazine, and lorazepam in the treatment of delirium in hospitalized AIDS patients.

OBJECTIVE: The purpose of this study was to examine the efficacy and side effects of haloperidol, chlorpromazine, and lorazepam for the treatment of the symptoms of delirium in adult AIDS patients in a randomized, double-blind, comparison trial. METHOD: Nondelirious, medically hospitalized AIDS patients (N = 244) consented to participate in the study and were monitored prospectively for the development of delirium. Patients entered the treatment phase of the study if they met DSM-III-R criteria for delirium and scored 13 or greater on the Delirium Rating Scale. Thirty patients were randomly assigned to treatment with haloperidol (N = 11), chlorpromazine (N = 13), or lorazepam (N = 6). Efficacy and side effects associated with the treatment were measured with repeated assessments using the Delirium Rating Scale, the Mini-Mental State, and the Extrapyramidal Symptom Rating Scale. RESULTS: Treatment with either haloperidol or chlorpromazine in relatively low doses resulted in significant improvement in the symptoms of delirium as measured by the Delirium Rating Scale. No improvement in the symptoms of delirium was found in the lorazepam group. Cognitive function, as measured by the Mini-Mental State, improved significantly from baseline to day 2 for patients receiving chlorpromazine. Treatment with haloperidol or chlorpromazine was associated with an extremely low prevalence of extrapyramidal side effects. All patients receiving lorazepam, however, developed treatment-limiting adverse effects. Although only a small number of patients had been treated with lorazepam, the authors became sufficiently concerned with the adverse effects to terminate that arm of the protocol early. CONCLUSIONS: Symptoms of delirium in medically hospitalized AIDS patients may be treated efficaciously with few side effects by using low-dose neuroleptics (haloperidol or chlorpromazine). Lorazepam alone appears to be ineffective and associated with treatment-limiting adverse effects.

AIDS Dementia Complex↗