Showing papers by "University of Catania published in 1987"

The frequency of cold thyroid nodules and thyroid malignancies in patients from an iodine-deficient area

Abstract: An analysis of thyroid cancer morbidity was carried out in two adjacent areas of Sicily differing in iodine intake A consecutive series of 911 patients with "cold" nodules from an iodine-deficient area (IDA) and 2537 from a control area (CA) were examined by fine needle aspiration and selected for surgery and pathologic examination Malignancies were found in 27 of the patients (296%) from the IDA and in 139 patients (548%) from the CA Based on a population survey indicating that "cold" thyroid nodules were 25 times more frequent in the IDA with respect to the CA, we calculated a prevalence of 127 thyroid cancers per 10(5) inhabitants in the IDA versus 93 in the CA (P less than 0001) Moreover, follicular and anaplastic carcinomas were three times more frequent in the IDA than in the CA (75 versus 24 cases per 10(5) inhabitants, respectively) These studies indicate that iodine deficiency may be one factor in the development of certain thyroid malignancies in man

Relationship between the efficiency of muscular work during jumping and the energetics of running.

Abstract: The running economy of seventeen athletes was studied during running at a low speed (3.3 m · s−1) on a motor-driven treadmill. The net energetic cost during running expressed in kJ·kg−1·km−1 was on average 4.06. As expected, a positive relationship was found between the energetic cost and the percentage of fast twitch fibres (r=0.60,n=17,p<0.01). In addition, the mechanical efficiency during two different series of jumps performed with and without prestretch was measured in thirteen subjects. The effect of prestretch on muscle economy was represented by the ratio between the efficiency of muscular work performed during prestretch jumps and the corresponding value calculated in no prestretch conditions. This ratio demonstrated a statistically significant relationship with energy expenditure during running (r=−0.66,n=13,P<0.01), suggesting that the elastic behaviour of leg extensor muscles is similar in running and jumping if the speeds of muscular contraction during eccentric and concentric work are of similar magnitudes.

The progenitor of SN1987A

Abstract: One of the reasons why the bright supernova SN1987A is of such importance is the fact that its proximity would allow for the first time, the identification of a supernova progenitor star. Attempts to establish which star was the progenitor have led to uncertainties, however. Here we use spatial and spectroscopic information from International Ultraviolet Explorer (IUE) spectra in the range 1,150–1,950A to demonstrate that Sk–69 202, the star coinciding positionally with the Large Magellanic Cloud (LMC) supernova, has disappeared from sight. Two weaker sources, named star 2 and star 3 in the astrometric analysis of the image of Sk–69 202 before the supernova outburst, are still present in the ultraviolet spectra. We isolate their spectra and give a spectral classification. We conclude that Sk-69 202 is the progenitor the LMC supernova.

Thyrotropin Stimulates Glucose Transport in Cultured Rat Thyroid Cells

Abstract: Glucose transport by FRTL-5 cells, a rat thyroid cell line, was found to be TSH dependent. The effect of TSH on the uptake of 2-deoxy-D-glucose, a nonmetabolizable glucose analogue, was prompt, being 200% over basal value after 10 min and maximal after 12 h (600-700% increase). The TSH effect was dose dependent, with half-maximum stimulation at 10 microU TSH/ml, and maximum stimulation at 1 mU TSH/ml. TSH enhanced also the uptake of 3-O-methyl-D-glucose by FRTL-5 cells. The TSH activation of glucose transport had the following characteristics: it was mimicked by (Bu)2-cAMP (1 mM) and by agents that increase cAMP levels in thyroid cells, such as forskolin (10 microM) and cholera toxin (50 micrograms/ml); it involved the facilitated glucose transport system in that it was inhibited in a dose-related manner by both cytochalasin B and phloretin; it showed a glucose stereochemical sensitivity, being affected by D-glucose and 3-O-methyl-glucose, and not by L-glucose; it was characterized by an increase in the maximum velocity (Vmax) of glucose uptake (from 15.3 to 66.0 fmol/min X micrograms DNA) without change in the Michaelis-Menten constant (Km) (5.3 mM); the effect on the Vmax was due to an increase in the number of surface glucose transporters as indicated by the enhancement of the D-glucose-sensitive fraction of [3H]cytochalasin B binding sites that in thyroid plasma membranes of cells exposed to TSH for 2 and 8 h, increased from 5.0 (basal value) to 10.4 and 23.1 pmol/mg protein, respectively. These data indicate that in FRTL-5 cells TSH stimulates the glucose transport system by an enhancement of the number of functional glucose transporters in the thyroid plasma membrane.

Density enhancement in ion implanted polymers

Abstract: Ion beam irradiation of polystyrene and polyimide films induces a strong densification of the starting material. The density increases to about 70% of the initial value after bombardment with heavy ions (Ar, Kr, Xe etc) in the energy range 25–250 key. The density change does not depend on the chemical structure and seems to be a general property of the irradiated polymers. The energy deposited along the ion track is the key parameter of the investigated process.

Molecular weight distribution and solubility changes in ion-bombarded polystyrene

Abstract: Among the chemical and physical modifications induced by ion bombardment on polymers, solubility changes have attracted considerable attention owing to the technological interest for microlithography purpose. The solubility changes are due to occurrence of cross-linking and scission at molecular level with heavy modification of the molecular weight distribution too. The molecular weight distribution of implanted polystyrene shows considerable changes upon bombardment. These changes have been followed on bombarded nearly-monodisperse PS samples. The use of samples with known molecular weight distribution allows to apply the Gel Theory for determining the chemical yields. This method is a direct, relatively simple tool for following the chemical modifications in bombarded polymers.

Relationship between melanin content and superoxide dismutase (SOD) activity in the liver of various species of animals

Abstract: The scavenger effect of melanin and of superoxide dismutase (SOD) activity on superoxide anion has been shown. In this work we show the relationship between melanin content and SOD activity in livers containing different quantities of melanin which were taken from various species of animals. The mitochondrial SOD activity disappears when the melanin content in the liver is very high; moreover it increases, in the liver of various species of animals examined, proportionally to the decrease of melanin content. No significant variation of the SOD activity localized in the soluble fraction has been detected when related to the melanin content. We think that in the pigmented liver the antioxidant activity of the melanin could mimic part of the function of SOD. The loss of Mn SOD activity could be mediated by a low intracellular level of superoxide anion due to the scavenger effect of melanin on superoxide anion; in fact, it is well known that the biosynthesis of Mn SOD is induced by intracellular levels of superoxide anion.

Ambroxol for the prevention of chronic bronchitis exacerbations: long-term multicenter trial. Protective effect of ambroxol against winter semester exacerbations: a double-blind study versus placebo

Abstract: In a 6-month, double-blind multicenter trial conducted over the winter, the effects of daily administration of ambroxol retard (75 mg) were compared with those of placebo in preventing exacerbations and improving symptoms and clinical signs in chronic bronchitis patients. The trial was completed by 110 patients in the ambroxol group and by 104 in the placebo group. Initially, there were no significant differences between the groups. By the end of the 2nd month of treatment, 67.2% of the ambroxol group had had no exacerbations compared to 50.4% in the placebo group. At the end of the 6-month trial, 45.5% of the treatment group had had no exacerbations, compared to only 14.4% of the control group. These differences were statistically significant. Patients in the treatment group lost significantly fewer days through illness (442) and had fewer days when they needed antibiotic therapy (371) compared to the placebo group patients (837 and 781). Ambroxol also produced statistically significant symptomatic improvement, measured as difficulty in expectoration, coughing, presence of dyspnea and the auscultatory signs as compared to controls. Since ambroxol was well tolerated and compliance was good, it appears like a drug of choice for pharmacological prophylaxis of chronic bronchitis.

Dynamics of plasma gonadotropin and sex steroid release in polycystic ovarian disease after pituitary-ovarian inhibition with an analog of gonadotropin-releasing hormone.

Abstract: To assess the dynamics of the suppression and recovery of plasma gonadotropins and sex steroids during and after inhibition of pituitary-ovarian function by a long-acting agonist GnRH-analog (GnRH-A), eight patients with polycystic ovarian disease were treated with 12 μg/kgday GnRH-A for 56 consecutive days. In response to GnRH-A, these patients had a sharp and pronounced decline of their initially elevated immunoreactive LH and bioactive LH (bioLH) levels. Plasma immunoreactive FSH levels declined more rapidly than did bioLH,but the FSH decline was less sustained. Plasma testosterone,androstenedione, and estrone (E1) levels also declined during GnRH-A administration. The pattern of plasma androgen decrease resembled that of bioLH. There was a positive correlation between bioLH and the two androgens (r = 0.85; P < 0.05, by Spearman’s rank correlation, for both hormones). Cessation of GnRH-A administration was followed by promptprogressive increases in gonadotropin and androgen concentrations to pretreatme...

Preparation of trimethyl-2-hydroxyethylarsonium (arsenocholine) compounds

Abstract: Trimethyl-2-X-ethylarsonium salts (X=OH, Cl, Br, CH3COO; anion=Br) and trimethyl-2-diethoxyethylarsonium bromide were prepared from trimethylarsine and the appropriate organic bromides in sealed tubes at elevated temperatures or by refluxing the neat reagents. The yields ranged from 33 to 85%. Anion exchange reactions produced the arsonium iodides, nitrates, acetates, tosylates, tetraphenylborates, picrates, hydroxides, and carbonates. Arsenocholine bromide (X=OH) was phosphorylated with concentrated phosphoric acid. The product was isolated as the barium salt. Treatment of the barium salt with sulfuric acid yielded trimethyl-2-(dihydrogen phosphato)ethylarsonium bromide. These substances were synthesized to serve as precursors for arsenic- containing phospholipids and as standards for the chromatographic identification of arsenocholines. The synthesized compounds were characterized by elemental analyses and 1H and 13C NMR spectroscopy. The shifts of the arsenic compounds were compared with those of the corresponding nitrogen compounds and found to be sufficiently different to be used for the identification of these compounds in their mixtures.

The effect of pre-stretch on mechanical efficiency of human skeletal muscle.

Abstract: The mechanical efficiency of positive work was studied in six subjects performing three different types of exercises. On the first occasion the subjects ran on a motor-driven treadmill at 3.33 m s-1; the second and the third exercises consisted of performing rhythmical vertical jumps for 1 min both in rebound (RJ) and no-rebound (NRJ) conditions. The mechanical efficiency calculated in NRJ, which reflects only the conversion of biochemical energy into mechanical work, was found to be lower than the corresponding observation in RJ, 17.2 vs. 27.8% (P less than 0.001), respectively. These differences could not be explained by only the storage and recoil of elastic energy occurring in RJ compared with NRJ. The calculated extra work delivered 'free' was greater than the potential elastic energy which could be stored within the leg extensor muscles (187 vs. 124 J for each jump, P less than 0.05). It is likely that other factors might be responsible for the extra work found in NRJ. It was suggested that the difference in the length of time to perform positive work between a simple shortening contraction and a stretch-shortening muscular activity could be also responsible for the enhanced efficiency observed in RJ. This suggestion was supported by the high relationship (P less than 0.001) found between the time to perform positive work and the mechanical efficiency measured in jumping and estimated during running.

Review of seismological studies at Mount Etna

Abstract: This paper reports the present state of seismological research at Mt. Etna. A schematic classification of the earthquakes that occur on the volcano is proposed, based on both seismogram and spectrum features. We have made both focal solutions and estimates of earthquake source parameters (stress drop values between 2 and 20 bars and small source dimensions). The crust of Etna thus appears as an extremely heterogeneous medium that does not permit great stress accumulation. The coexistence of an extensional regime with an older and deeper compressive one seems confirmed at depths greater than about 7 km. Eruptive and seismic phenomena occur mainly along the principal structural trends of the volcano, but often the directions of the eruptive fractures and the earthquake concentration during the same eruption do not coincide. Tectonics seem to play an important role in controlling seismo-volcanic behaviour.

Thermal Degradation Mechanisms in Condensation Polymers

Abstract: Thermal degradation processes occurring in the most common condensation polymers are examined. It is remarked that the inclusion of functional groups into a polymer chain lowers the importance of decomposition reactions involving free radical and multiple hydrogen-transfer processes. Therefore, condensation polymers tend to decompose by selective cleavage processes. Making a series of structural changes and then observing the corresponding variations in significant decomposition products, a consistent series of data has been obtained on the decomposition pathway of each class of polymers bearing different functional groups (polyurethanes, polyureas, polyesters, polycarbonates, polyamides, polyethers, polysulphides, polysiloxanes, polyphosphazenes, etc.).

Tactile exploration of space and visual neglect in brain-damaged patients.

Abstract: A maze test of tactile scanning was used to investigate the relationship between visual neglect and the tactile modality of space exploration in 46 patients with right-sided brain damage (RBD) (20 with and 26 without visual neglect), 27 patients with left-sided brain damage (LBD) and 30 controls. Both LBD and RBD patients that were free from visual neglect more frequently used the tactile mode to explore the space contralateral to the sound hemisphere, while the RBD patients affected by visual hemi-inattention preferred tactile scanning of the left, visually neglected, half of space. Some implications of these findings are discussed. In particular, the modality-specific nature of neglect phenomena and the possibility of tactile compensation are suggested.

Macromolecular Turnover in Brain during Aging

Abstract: During aging there are several structural, functional and biochemical alterations, including changes in macromolecular composition and turnover. Regulation of gene expression, DNA and RNA synthesis, total poly(A)+ and poly(A)- RNA contents, qualitative and quantitative changes of synaptosomal plasma membrane proteins, diminished plasticity, loss of synapses, lower rate of axoplasmic transport, impairment of antioxidant and bioenergetic systems seem to be involved in the aging process of nervous system.

Qualitative Organic Analysis. Part 2. Identification of Drugs by Principal Components Analysis of Standardized TLC Data in Four Eluent Systems and of Retention Indices on SE 30

Abstract: The principal components (PC) analysis of standardized Rf values in four eluent systems [ethyl acetate/methanol/30% ammonia (85:10:15), cyclohexane/toluene/diethylamine (65:25:10), ethyl acetate/chloroform (50:50), and acetone with the plate dipped in potassium hydroxide solution] and of gas chromatographic retention indices in SE 30 for 277 compounds provided a two-principal-components model that explains 82% of the total variance. The scores plot allowed identification of unknowns or restriction of the range of inquiry to very few candidates. Comparison of these candidates with those selected from another PC model derived from TLC data only allowed identification of the drug in all the examined cases.

Hypothalamic control of certain aspects of natural immunity in the mouse.

Abstract: Electrothermocoagulation (ETC) of the individual nuclei of the median region of the hypothalamus (MH) in the C57BL/6 mouse leads to a significant reduction in the cytotoxic activity of natural killer cells (NK) and the number of large granular lymphocytes (LGL) compared with intact or sham-operated controls. This effect, however, is less than that observed after simultaneous destruction of all MH nuclei. By contrast, no significant change in NK activity was noted after ETC of the anterior (AH) or posterior (PH) regions. Diminution of NK activity due to nuclear MH destruction is not an outcome of the change in adenohypophysis secretion provoked by hypothalamic lesion. Natural cytotoxic activity was markedly increased after ETG located either in AH, or MH, or PH. These results indicate that NK- and NC-mediated immunity is governed by a control mechanism situated in the hypothalamus.

Attenuation of short period seismic waves at Etna as compared to other volcanic areas

Abstract: CodaQ for Etna volcano is frequency dependent and theQ frequency pattern and the numerical values ranging from about 100 at 1 Hz to about 300 at 18 Hz are similar to the values obtained for other volcanoes: Campi Flegrei, Aeolian Islands and Hawaii. Moreover the frequency pattern and the numerical values of coda quality factor, for most of the seismically active zones of Italy are very different from those of the volcanic zones.

Delayed emission of hydrogen from ion bombardment of solid methane

Abstract: The decomposition of methane under ion bombardment can serve as a model for decomposition of more complex organic molecules and polymers A large quantity of hydrogen is released from initially pure solid methane films (− 01 to − 3 μm thick) at low temperatures in the progression from methane toward a carbon-rich polymer which is stable at room temperature To study this process we have observed the fluence dependence of the emission of D 2 under MeV He + and H + ion bombardment of solid deuterated methane The process of methane decomposition through hydrogen bond breaking must begin as the first bombarding ions penetrate the low temperature solid film and indeed a small external D 2 yield is observed immediately However, quite unexpectedly we find that the vast majority of D 2 release is delayed until a fluence threshold has been accumulated Above this threshold the external D 2 yield rises rapidly by more than an order-of-magnitude and subsequently decays as the film is depleted in deuterium For 15 MeV He + the threshold of the principal release occurs at ∼ 3 × 10 14 ions/cm 2 ; for 15 MeV H + , at ∼ 9 × 10 15 ion/cm 2 We interpret the delay in D 2 emission as due to the low diffusivity of deuterium in solid methane at 12–28 K and the fluence threshold as a percolation threshold at which a sufficient fraction of the methane has been modified to a material with high deuterium diffusivity to allow deuterium to escape

Ovarian Adrenergic Nerves Directly Participate in the Control of Luteinizing Hormone-Releasing Hormone and β-Adrenergic Receptors during Puberty: A Biochemical and Autoradiographic Study

Abstract: The rat ovary receives sympathetic innervation from the superior ovarian nerve (SON) and the plexus nerve (OP). To examine the possibility of a direct adrenergic mechanism controlling ovarian receptor distribution during the onset of puberty, we have studied the acute (48-h) effect of unilateral nervotomy (combined section of SON and OP nerves) on ovarian LHRH and β-adrenergic receptor concentrations and distribution using both radioreceptor assays and in vitro autoradiography. Ovarian LHRH receptor concentration increased sharply between 12 and 20 days of age. At this time receptors were mostly associated with follicles and interstitial cells, whereas at 37 days of age, when a measurable loss in the receptor concentration was observed, light and diffuse autoradiographic labeling of receptors was also found in the corpora lutea. Complete removal of adrenergic input to the gland produced a sharp decrease in LHRH-binding activity within the denervated ovary at each time interval studied, with no effect in t...

Dextrocardia with and without situs viscerum inversus in two sibs.

Abstract: We described two sibs born to consanguineous Sicilian parents who died of severe congenital heart malformation. Both had dextrocardia; however, only the girl had situs viscerum inversus. At necropsy she was found to have a right spleen and right pulmonary isomerism (three lobes in each lung, as commonly found in the asplenia syndrome). This observation, together with other literature reports, suggest that isolated dextrocardia, situs viscerum inversus, and the asplenia-polysplenia complex may be different end results of a unique dysmorphogenetic process involving the embryonic midline.

Petrological notes on the 1983 lavas at Mount Etna, Sicily, with reference to their REE and Sr—Nd isotope composition

Abstract: The 1983 hawaiite of Mount Etna was sampled and analyzed for groundmass and mineral compositions, rare-earth-element concentrations and Sr-Nd isotope ratios. Microprobe data for coexisting mineral phases and glass show crystallization temperatures of around 1100° C from a rather differentiated hawaiite magma at rather highfO2 (10−8 at 1100° C), well above the QFM buffer. The hawaiites are characterized by a marked enrichment in the light REE similar to other alkaline magmas: the (Ce)N/(Yb)N is greater than 10, a feature these hawaiites have in common with alkaline magmas erupted earlier on Mount Etna. Since the Ce/Yb ratio cannot be affected by fractionation of clinopyroxene and plagioclase, it is taken as an accurate reflection of the LREE-enriched nature of the hawaiites. From this point of view, the Etnean hawaiites are identical to within-plate alkaline magmas erupted on the Hawaiian islands. This similarity extends to the Nd-Sr isotope features. Two hawaiites have87Sr/86Sr=0.70346 and 0.70352 and143Nd/144Nd=0.51286 and 0.51284. These data indicate a source similar to oceanic-island basalts, a source depleted in Rb/Sr and Nd/Sm for some period of time. The Sr isotope data are identical to that previously reported for Mount Etna. Extraction of hawaiites from depleted source regions requires either recent enrichment events, mixing of asthenospheric and lithospheric melts, or variable degrees of melting. At present, the data do not allow a clear decision. The peculiar tectonic setting of Mount Etna, between the relatively undeformed African foreland and the active Aeolian volcanic islands, may suggest contributions to the source region from subduction and within-plate processes. Etnean lavas have a geochemical imprint of subduction-related enrichment processes, and they also share petrological and chemical features identical to oceanic-island basalts whose source region has been affected by within-palte enrichment processes.

Thermal decomposition processes in aromatic‐aliphatic polyamides investigated by mass spectrometry

Abstract: The thermal decomposition processes of some aromatic-aliphatic polymides, derived from terephthalic acid and aliphatic diamines, were studied by flash Pyrolysis-GCMS and by direct Pyrolysis-Mass Spectrometry, using both Chemical lonization and Electron Impact modes. The results indicate that the primary thermal decomposition proceeds via a β-CH hydrogen transfer process, with formation of pyrolysis products containing amide and olefin end-groups. Nitrile end-groups are also formed by dehydration of the amide groups formed in the primary decompostion process.

Bronchodilator effect of Aerochamber and Inspirease in comparison with metered dose inhaler.

Abstract: This trial was performed in a randomized double-blind manner on four different days in 13 asthmatic patients in order to compare the bronchodilator efficacy of two different inhalation devices, Inspirease (IP) and Aerochamber (AC), to the conventional metered dose inhaler (MDI). The results showed that clenbuterol determined a significant FEV1 increase inhaled either via MDI or via IP and AC. IP caused a greater bronchodilatation than AC, 30 min after clenbuterol administration. IP caused a greater mean increase (P less than 0.05) in FEV1 than the MDI at all time intervals; AC provided an improvement in bronchodilator response over directly administered MDI. Such responses are only marginally clinically relevant when patients use MDI correctly. These devices are mainly indicated in patients with poor hand-lung coordination.

An approach to problems on energy sources at Mount Etna based on seismological and volcanological data

Abstract: Based on seismograms from the most continuously operating station of the seismic network at Mt. Etna (Monte Vetore, 1665 m a.s.l.), the energy release patterns through time have been obtained for volcanic tremors and earthquakes which occurred between 1978–1982. Both energies range between 1011∓1013 J/a, but their release patterns are not strictly correlated to each other. Considering only the eruptions which occurred during the same time span, the amount of thermal energy released and the associated potential energy needed to raise the magma to the surface from a 2-km-deep hydrostatic equilibrium level were estimated to be about 1017 and 1015 J/a, respectively. The computed energies for earthquakes and tremors are at least one order of magnitude less than what is needed to match a model of magma transport based solely on the jerky propagation of melt-filled cracks. The energy needed to raise the magma to the surface could be supplied by expanding gases in the upper levels of the magma column and/or by tectonic stresses acting on shallow batches of magma.