Biomedical subjects

S Cappello

Publications and source records attributed to S Cappello.

18 recordsLinked to original sources

PubMed2007

Microbial community dynamics during assays of harbour oil spill bioremediation: a microscale simulation study.

AIMS: Microcosm experiments simulating an oil spill event were performed to evaluate the response of the natural microbial community structure of Messina harbour seawater following the accidental load of petroleum. METHODS AND RESULTS: An experimental harbour seawater microcosm, supplemented with nutrients and crude oil, was monitored above 15 days in comparison with unpolluted ones (control microcosms). Bacterial cells were counted with a Live/Dead BacLight viability kit; leucine aminopeptidase, beta-glucosidase, alkaline phosphatase, lipase and esterase enzymes were measured using fluorogenic substrates. The microbial community dynamic was monitored by isolation of total RNA, RT-PCR amplification of 16S rRNA, cloning and sequencing. Oil addition stimulated an increase of the total bacterial abundance, leucine aminopeptidase and phosphatase activity rates, as well as a change in the community structure. This suggested a prompt response of micro-organisms to the load of petroleum hydrocarbons. CONCLUSIONS: The present study on the viability, specific composition and metabolic characteristics of the microbial community allows a more precise assessment of oil pollution. Both structural and functional parameters offer interesting perspectives as indicators to monitor changes caused by petroleum hydrocarbons. SIGNIFICANCE AND IMPACT OF THE STUDY: A better knowledge of microbial structural successions at oil-polluted sites is essential for environmental bioremediation. Data obtained in microcosm studies improve our understanding of natural processes occurring during oil spills.

Alcanivoraceae↗

PubMed2006

Transport barrier inside the reversal surface in the chaotic regime of the reversed-field pinch.

Magnetic field lines and the corresponding particle orbits are computed for a typical chaotic magnetic field provided by a magnetohydrodynamics numerical simulation of the reversed-field pinch. The m = 1 modes are phase locked and produce a toroidally localized bulging of the plasma which increases particle transport. The m = 0 and m = 1 modes produce magnetic chaos implying poor confinement. However, they also allow for the formation of magnetic islands which induce transport barriers inside the reversal surface.

Journal Article↗

PubMed2006

Cypermethrin toxicity to aquatic life: bioassays for the freshwater prawn Palaemonetes argentinus.

Cypermethrin (CY) effects were evaluated in freshwater prawn Palaemonetes argentinus, a common member of the aquatic fauna in the vegetated littoral of lotic and lentic environment of La Plata basin. LC50 was calculated, and oxygen uptakes together with ammonia-N excretion were related to biocide concentrations. Behavioral and growth changes were analyzed, and a unique application of CY was evaluated in P. argentinus micropopulations. LC50 and their 95% confidence limit were 0.0031 microg CY L(-1) (0.0023-0.0039) for 24 h and 0.0020 microg CY L(-1) (0.0014-0.0027) for 96 h. Oxygen uptake and ammonia-N excretion increased in the prawns kept in CY solutions. The behavioral effect was hyperactivity. Although prawns in biocide groups have null or negative growth, the intermolt period was 246% larger than in the control group. Moreover, the mortality in the second cycle was 100%. A unique application of pyrethoid provoked high mortality after 50 days. The low concentrations of this biocide affected the survival and altered the prawn metabolic activity, behavioral and ecdysis cycle. These results suggest that juveniles of P. argentinus are much more sensitive to CY pollution than other crustaceans, fish, and tadpoles.

Ammonia↗

PubMed2005

Dominant electrostatic nature of the reversed field pinch dynamo.

The origin of the dynamo velocity field of the reversed field pinch within the visco-resistive MHD modeling is uncovered. The main component of this field is an electrostatic drift. The corresponding electrostatic field is related to a small charge separation which is consistent with the quasineutrality approximation, and which should be present in real plasmas, too. While quite natural in the stationary single helicity state, this analysis is shown to extend also to the nonstationary multiple helicity regime. Numerical simulations provide the spatial distribution of fields and of charge separation.

Journal Article↗

PubMed2004

Measurements of the MHD dynamo in the quasi-single-helicity reversed-field pinch.

The first experimental study of the MHD dynamo in a quasi-single-helicity (QSH) reversed-field pinch toroidal plasma is presented. In QSH plasmas, a dominant wave number appears in the velocity fluctuation spectrum. This velocity component extends throughout the plasma volume and couples with magnetic fluctuations to produce a significant MHD dynamo electric field. The narrowing of the velocity fluctuation spectrum and the single-mode character of the dynamo are features predicted by theory and computation, but only now are observed in experiment.

Journal Article↗

PubMed2000

Bifurcation in viscoresistive MHD: the hartmann number and the reversed field pinch

A scaling approach to the simplest viscoresistive MHD model reveals that the Prandtl number acts only through the inertia term. When this term is negligible the dynamics is ruled by the Hartmann number H only. This occurs for the reversed field pinch dynamics as seen by numerical simulation of the model. When H is large the system is in a multiple helicity state. In the vicinity of H = 2500 the system displays temporal intermittency with laminar phases of quasi-single-helicity (SH) type. For lower H's two basins of SH are shown to coexist. SH regimes are of interest because of their nonchaotic magnetic field.

Journal Article↗

PubMed2000

Effect of immunological adjuvant combinations on the antibody and T-cell response to vaccination with MUC1-KLH and GD3-KLH conjugates.

A year ago we described a comparison of 19 immunological adjuvants for their ability to augment antibody and T-cell responses against vaccines containing two cancer antigens, GD3 ganglioside and MUC1 peptide, covalently attached to keyhole limpet hemocyanin (KLH). As in our previous experience, the saponin fraction QS-21 was the most potent single adjuvant but several other adjuvants also had potent adjuvant activity. Induction of an immune response against cancer antigens is generally difficult because these antigens are autoantigens. To get maximal benefit from the adjuvant component of cancer vaccines we have now tested whether combinations of the optimal adjuvants induced an improved immune response compared to QS-21 alone. Since over the intervening year a new semi-synthetic saponin adjuvant (GPI-0100) containing the dodecylamide derivative of hydrolyzed naturally-occurring saponins had become available, this was tested as well. Twelve different adjuvant combinations and GPI-0100 were compared for their ability to augment (1) antibody responses against GD3 and MUC1 and (2) T-cell responses against GD3, MUC1 and KLH. GPI-0100 and five adjuvant combinations were superior to QS-21 alone for induction of IgM and IgG antibodies against MUC1 and/or GD3: QS-21 plus bacterial nucleotide CpG, QS-21 plus monophosphoryl lipid A (MPL), QS-21 plus non-ionic block copolymer CRL-1005, QS-21 plus Titermax and Titermax plus CpG. Antibody responses were documented both by ELISA against purified antigens and by FACS for cell surface reactivity. There was no evidence for T-cell immunity against GD3 or MUC1. The antibody responses against GD3 and MUC1 were, however, strongly correlated with IFN-gamma release and DTH against KLH. These results demonstrate that combinations of immunological adjuvants are able to augment antibody and T-cell responses to these conjugates beyond that attainable with QS-21 alone, and again confirm the absolute necessity of potent adjuvants or adjuvant combinations for optimal immunogenicity with conjugate vaccines.

Adjuvants, Immunologic↗

PubMed2000

Chaos healing by separatrix disappearance and quasisingle helicity states of the reversed field pinch.

The resilience to chaotic perturbations of one-parameter one-degree-of-freedom Hamiltonian dynamics is shown to increase when its corresponding separatrix vanishes due to a saddle-node bifurcation. This is first highlighted for the magnetic chaos related to quasisingle helicity (QSH) states of the reversed field pinch. It provides a rationale for the confinement improvement of helical structures experimentally found for QSH plasmas; such a feature would not be expected from the classical resonance overlap picture as the separatrix disappearance occurs when the amplitude of the dominant mode increases.

Journal Article↗

PubMed2000

Quasi-single-helicity reversed-field-pinch plasmas

The reversed field pinch (RFP) is a configuration for plasma magnetic confinement. It has been traditionally viewed as dominated by a bath of MHD instabilities producing magnetic chaos and high energy transport. We report experimental results which go beyond this view. They show a decrease of magnetic chaos and the formation of a coherent helical structure in the plasma, whose imaging and temperature profile are provided for the first time. These quasi-single-helicity states are observed both transiently and in stationary conditions. The last case is consistent with a theoretically predicted bifurcation. Our results set a new frame for improving confinement in high current nonchaotic RFP's.

Journal Article↗

PubMed1999

Vaccines prepared with sialyl-Tn and sialyl-Tn trimers using the 4-(4-maleimidomethyl)cyclohexane-1-carboxyl hydrazide linker group result in optimal antibody titers against ovine submaxillary mucin and sialyl-Tn-positive tumor cells.

Sialyl-Tn (STn) is an O-serine- or O-threonine-linked disaccharide [NeuAcalpha(2-->6)GalNAcalpha-O-Ser/Thr) expressed on mucins of most types of adenocarcinoma as single STn or clustered STn [STn(c)] epitopes. Though STn is expressed on some normal tissues it is relatively tumor-specific, especially in the clustered conformation. Clinical trials with STn-keyhole limpet hemocyanin (KLH) conjugate vaccines, prepared using reductive amination with a two-carbon linker group, have resulted in high titers against STn but lower titers against natural forms of STn (ovine submaxillary mucin, or tumor cells). To obtain antibodies of more appropriate specificity, we attempted to prepare STn(c)-KLH conjugates to establish their immunogenicity in mice in preparation for clinical trials; however, conjugation efficiency was poor when the same two-carbon linker was used, presumably because of steric hindrance. STn-KLH and STn(c)-KLH conjugates were prepared using the regular two-carbon or the recently developed more efficient longer heterobifunctional 4-(4-maleimidomethyl)cyclohexane-1-carboxyl hydrazide (MMCCH) linkers, and the resulting immunogenicities in mice were compared. The highest titers against STn were seen with the STn-KLH conjugate with the two-carbon linker, and the highest titers against STn(c) were seen with STn(c)-KLH with the MMCCH linker. Conjugation with MMCCH resulted in the highest conjugation efficiency (yield) and the highest titers against ovine submaxillary mucin and STn-positive tumor cells, and is the method of choice for the preparation of STn(c) vaccine for clinical trials.

Animals↗

PubMed1999

Immunization of mice with fucosyl-GM1 conjugated with keyhole limpet hemocyanin results in antibodies against human small-cell lung cancer cells.

Fucosyl-GM1 (Fuc-GM1) [Fucalpha1 --> 2Galbeta1 --> 3GalNAcbeta1 --> 4(NeuAcalpha2-3)Galbeta1 --> 4Glcbeta1 --> O-Cer] is a small-cell-lung-cancer (SCLC)-associated ganglioside initially defined by the murine monoclonal antibody F12. On the basis of its known distribution, Fuc-GM1 is a potential target for active immunotherapy in SCLC patients. Fuc-GM1 has been extracted and purified from bovine thyroid. The immunogenicity of Fuc-GM1 was tested in mice either alone, mixed with carrier protein keyhole limpet hemocyanin (KLH) or covalently linked with KLH, plus immunological adjuvant QS-21. The Fuc-GM1-KLH conjugate plus QS-21 adjuvant was found to be optimal. It induced consistent IgM and IgG enzyme-linked immunosorbent assay (ELISA) titers against Fuc-GM1. These antibodies were strongly reactive with the strongly Fuc-GM1-positive rat hepatoma cell line H4-II-E, and they were moderately reactive with the moderately positive human SCLC cell line H146 by flow cytometry and complement-mediated lysis. Both ELISA and fluorescence-activated cell sorting (FACS) reactions were inhibited with Fuc-GM1or H4-II-E but not with the structurally related ganglioside GM1 or Fuc-GM1-negative colon cancer cell line LS-C. On the basis of these results, a vaccine comprising Fuc-GM1-KLH plus QS-21 is being prepared for testing in patients with SCLC.

Adjuvants, Immunologic↗

PubMed1996

Prevalence of stroke: a door-to-door survey in three Sicilian municipalities. Sicilian Neuroepidemiologic Study (SNES) Group.

As part of a door-to-door survey, we screened for stroke among the inhabitants of three Sicilian municipalities (n = 24,496 as of November 1, 1987). Neurologists then investigated those subjects suspected to have had a stroke. Diagnoses of first-ever strokes were based on specified criteria and were reviewed by an adjudication panel. We found 189 subjects who had experienced at least one completed stroke (180 definite, 9 possible); 15 strokes were hemorrhagic, 71 ischemic, and 103 uncertain. The prevalence (cases/100,000) was 771.6 in the total population and 1,893.6 in those aged 40 years or over. The prevalence increased steeply with age, was higher in men between 60 and 79 years, but was higher in women thereafter. Age-specific figures were similar in the three study municipalities. Although all first-ever strokes had been previously diagnosed, 40% of the subjects had not been hospitalized for this condition.

Adult↗

PubMed1992

Epidemiological survey of multiple sclerosis in Catania city.

The findings of an epidemiological survey of multiple sclerosis (MS) in the urban area of Catania reveal a new and in some respects original pattern of MS cases recorded on 31 December 1989 (prevalence day). They explain why special attention should be paid to patients residing in that area, which shows a remarkable upward trend of the MS prevalence rates calling for further study and for more targeted intervention in the fields of prevention, treatment and rehabilitation.

Adolescent↗

PubMed1990

[Acute postintervention cholecystitis].

A case of postoperative cholecystitis in a 64 years old man is reported. This is a nosological entity characterized by gallbladder distension without any patent obstacle in the cystic duct and constancy of necrosis involving all the parietal layers. Clinical signs and symptoms are aspecific. Mortality rate is high and diagnosis has to be done quickly because the gallbladder necrosis makes cholecystectomy compulsory on such patients.

Acute Disease↗

PubMed1989

Projections of the nucleus accumbens in the cat.

Due to the recent advances in knowledge on the function of the limbic system it would be wise to consider this system as being widely distributed throughout the diencephalic and mesencephalic levels as well as the forebrain. Numerous regions have been discovered that are related to the limbic structures in anatomical and functional respects. According to Koikegami et al. (1967), it would be adequate to divide this system into two main categories--the major limbic rim or the structure proper and the paralimbic structures. The former defined phylogenetically and ontogenetically as those structures around the third ventricle such as: the hippocampus, septum, dentate gyrus, fimbria hippocampi, anterior and posterior cingulate gyri, area paraolfactoria, amygdala and Diagonal Band of Broca. The paralimbic structures may represent those brain regions, which have direct connections or functional correlations with the limbic formation proper. These areas include the posterior orbital gyrus, insula, nucleus accumbens, head of the caudate, nucleus habenula, nucleus interpendencularis, nucleus pulvinaris thalami, intralaminar and anterior thalamic nucleus, preoptic area, hypothalamic nuclei, mammillary body, subthalamus, limbic midbrain area of Nauta, temporal lobe pole, superior temporal gyrus, praecuneus, nucleus dorsalis et profundis tegmenti of Gudden and claustrum. In the present paper we will deal with the projections of the nucleus accumbens. This nucleus was described by Meynert (1872) as the anterior polar region of the caudate nucleus. Kappers describes the nucleus accumbens in 1908 as the nucleus accumbens septi and considers it as a part of the striatum. Later on, the histological studies of Brochaus (1942) relate a part of the nucleus with olfactory functions, and he describes another part, which is very well developed in microsmatic mammals and in anosmic mammals like the dolphin. Szteyn (1960) describes two main areas, the accumbens septi and the accumbens caudate. Nevertheless, the accumbens constitutes a very important region of the paralimbic system and seems to play an important role in some behavioral patterns.

Animals↗

PubMed1978

Comparative anatomy of the caudate nucleus in different mammals.

Volumetric comparisons of the caudate nucleus of different mammals including rat, rabbit, cat, zebra, deer, antelope, bull, horse, dolphin (Stenella graffmani) and human are presented. A linear regression coefficient is obtained with its corresponding correlation coefficient. The results indicate that there is not a close correlation between the size of the caudate nucleus and the brain weight of the different animals studied when the caudate of the horse is included. When it is omitted there is a close correspondence. The caudate nucleus of the horse is extremely large in relation to its brain weight. The possible meaning of this fact is discussed. Measurement of different brain structures is of interest, both from the purely descriptive aspect and because it can suggest phylogenetic relations as well as explanation of functional differences in different animal species (1, 2).

Animals↗

PubMedDate not supplied

Morphologic variations in bacteria under stress conditions: near-field optical studies.

The morphologic and structural variations suffered by cells of a population of Pseudomonas aeruginosa ATCC 27853 under stress conditions were investigated by using scanning near-field optical microscopy. The analysis of the images, supported by microbiological data, showed that the bacteria evolved from the initial distribution of rod-shaped cells of standard size to a population with structural and morphologic modifications. The detection of variations in the optical reflectivity over a subwavelength scale (< or = 100 nm), combined with the concurrently acquired topographical signal, allowed the visualisation of rod-shaped bacteria going towards a lytic process and entire "U"-shaped cells. In the latter cells, which derived from a morphology refolding of rod bacteria, cellular matter seemed to rearrange itself to attain a coccoid stress resistant form, responsible for the residual viability of the population.

Biomass↗

PubMedDate not supplied

[Acute pneumonia caused by aspiration of hydrocarbons in a fire-eater].

Accidental aspiration of fuel in fire eaters can cause an acute chemical pneumonitis known as 'fire-eater's pneumonia". We report a case in a 29 year-old fire-eater. Six hours after aspiration of kerosene, he developed fever up to 39,5 degrees C, dyspnea, cough and chest pain. Chest radiograph showed infiltrates in the middle and lower parts of the lungs and left pleural effusion. He was treated with an antibiotic and antipiretic therapy and then with corticosteroids. The acute stage lasted four weeks and the patient recovered without sequelae within 3 months. Hazard related to main fuels used for fire eating is discussed.

Acute Disease↗