Showing papers by "Sapienza University of Rome published in 1981"
TL;DR: In this paper, a complete solution to nonlinear decoupling and noninteracting control problems is made possible via a suitable nonlinear generalization of several powerful geometric concepts already introduced in studying linear multivariable control systems.
Abstract: The paper deals with the nonlinear decoupling and noninteracting control problems. A complete solution to those problems is made possible via a suitable nonlinear generalization of several powerful geometric concepts already introduced in studying linear multivariable control systems. The paper also includes algorithms concerned with the actual construction of the appropriate control laws.
597 citations
TL;DR: It was found that the optimal conditions for germ cell detachment without Sertoli cell impairment consist of incubation for 2.5 minutes at 20 C in 20 m TRISHCI.
Abstract: A new technique involving a brief hypotonic treatment was developed for obtaining pure rat Sertoli cell cultures. This method for the selective removal of the germ cells present in Sertoli cell enriched cultures (SCEC) Is based on the differential response of the two cell types to changes in osmolarity. It was found that the optimal conditions for germ cell detachment without Sertoli cell impairment consist of incubation for 2.5 minutes at 20 C in 20 m TRISHCI. When compared with SCEC, the Sertolicell-only cultures (SCOC) thus obtained retain unaltered morphologic features and responsiveness to FSH stimulation (morphologic modifications and 17 β-estradiol secretion). The availability of pure Sertoli cell cultures (Ie, free of contaminating germ cells) provides an advantage in the study of their metabolic activity. Moreover, with this technique it is feasible to compare Sertoli cell function in association with germ cells to function in the absence of germ cells.
406 citations
TL;DR: Dermorphin and Hyp6‐dermorphin are the first representatives of a new class of potent opioid peptides occurring in amphibian skin and present the unique feature of having a D‐Ala residue incorporated in the peptide molecule.
Abstract: 1 Dermorphin and Hyp6-dermorphin are the first representatives of a new class of potent opioid peptides occurring in amphibian skin. They present the unique feature of having a D-Ala residue incorporated in the peptide molecule. 2 Dermorphin displayed a potent depressive action on electrically stimulated contractions of the guinea-pig ileum and mouse vas deferens preparations. Dermorphin was respectively 57,294, 18 and 39 times more potent than Met-enkephalin, Leu-enkephalin, beta-endorphin, and morphine on the guinea-pig ileum opiate receptors. On the vas deferens receptors, dermorphin was about as potent as the enkephalins and 40 times more potent than morphine. Naloxone was a powerful antagonist to dermorphin in both preparations. 3 Dermorphin produced potent and long-lasting analgesia in mice by intravenous injection, and in rats by intracerebroventricular injection, the ED50 being here of the order of 13-23 pmol/rat. Morphine was 752 and 2170 times less potent, depending on the analgesia test used. At high intracerebroventricular doses analgesia was accompanied by catalepsy. 4 Intracerebroventricular infusion of dermorphin induced development of tolerance and precipitation of withdrawal symptoms upon administration of naloxone. Both tolerance and physical dependence was consistently less marked with dermorphin than with morphine. 5 The minimum sequence requirement for full dermorphin activity was represented by the N-terminal tetrapeptide. The presence of the D-Ala2-residue was of crucial importance.
320 citations
TL;DR: Patients who had only abnormal metaphases had poorer prognosis than those with normal bone marrow metaphases only and this correlation was obvious in patients classified as acute myeloid leukemia (AML) as well as in the monocytic varieties of ANLL.
229 citations
TL;DR: The displacement of points lying on the longitudinal axis of the upper part of the human body at head, shoulder and pelvis level was estimated in the three dimensions of space during level walking on a straight line at speeds ranging from 0.99 to 2.79 m s−1.
155 citations
TL;DR: The results showed that oral administration of a combination of two amino acids provoked a release of pituitary somatotropin and insulin, and the growth hormone secreted in response to this stimulation had biological activity.
Abstract: SummaryA study was carried out in 15 male volunteers to evaluate qualitatively the secretion of growth factors following stimulation by oral amino acids. The results showed that oral administration of a combination of two amino acids (1200 mg l-lysine plus 1200 mg l-arginine) provoked a release of pituitary somatotropin and insulin. This phenomenon was reproducible and the growth hormone secreted in response to this stimulation had biological activity {as demonstrated by a radioreceptor assay and somatomedin induction). The effect appeared to be specific to the combination of the two amino acids; neither of the amino acids demonstrated appreciable stimulating activity when administered alone, even at the same doses.
146 citations
TL;DR: The optical and circular dichroism spectra show that the heme environment in HbI and HbII resembles that of vertebrate hemoglobins, although distinctive features are present in the deoxygenated derivative.
144 citations
TL;DR: The potent stimulant effect of sauvagine on ACTH and beta-endorphin release has been confirmed both in vivo and on columns of isolated and dispersed rat pituitary cells, and similarly the potent inhibitory effect on PRL and GH release, both in the rat and man.
130 citations
TL;DR: A method has been developed for the electrophoretic and quantitative analyses of human red cell δ‐aminolevulinate dehydrase (ALADH), under the control of an autosomal gene, with two common codominant alleles with frequencies of 0–89 and Oil, respectively.
Abstract: SUMMARY
A method has been developed for the electrophoretic and quantitative analyses of human red cell δ-aminolevulinate dehydrase (ALADH). The enzyme is under the control of an autosomal gene, with two common codominant alleles, ALADH1 and ALADH2, with frequencies of 0–89 and Oil, respectively, in the Italian population. Mean phenotypic enzyme activities are nearly identical: 52, 49 and 55 mlU/g Hb for ALADH 1, 2-1 and 2 phenotypes respectively.
115 citations
TL;DR: PMN transfusion was a highly effective therapeutic tool in the population of infected newborn infants with bacterial sepsis proven by blood culture andUntoward effects attributable to PMN transfusions were never observed.
97 citations
TL;DR: Several years after the introduction of modern cytological techniques in the karyological study of the bony fishes, an attempt may be made to take stock of the results obtained, the problems raised and the difficulties encountered by workers engaged in this type of investigation.
Abstract: Several years after the introduction of modern cytological techniques in the karyological study of the bony fishes, an attempt may be made to take stock of the results obtained, the problems raised and the difficulties encountered by workers engaged in this type of investigation. The first limitation is set by the value of the karyotype itself. Because it is purely morphological and its immediate adaptive value is unknown, karyotype transformations are difficult to interpret in analyses of populations of the same species or of related species. When related species are being compared, similar karyotypes are considered indicative of a relatively recent separation, whereas widely differing karyotypes are believed to indicate an earlier separation.However, this assumption is not always valid. In the bony fishes a karyotype composed of 48 acrocentric chromosomes occurs not only in related species but also in species that are phylogenetically further apart. In some taxa the karyotype therefore appears ‘neutral’ with respect to both speciation and phyletic evolution (Fig. 1) and it is therefore often impossible to establish a definite correlation between karyotype and karyotype transformations and to identify the processes involved. Although this situation diminishes the immediate value of the karyological evidence, it raises a series of questions that, when set in the right problematical context, make karyological analyses extremely interesting .
TL;DR: In this article, a reconnaissance study has identified regularities in geochemical parameters over enormous geographical regions, and these patterns are not well understood but merit more detailed examination because they contain information critical to our understanding of the development of granitoid batholiths.
Abstract: 18O, D, and H2O+ contents were measured for whole-rock specimens of granitoid rocks from 131 localitics in California and southwestern Oregon. With 41 new determinations in the Klamath Mountains and Sierra Nevada, initial strontium isotope ratios are known for 104 of these samples. Large variations in δ
18O (5.5 to 12.4), δD (−130 to −31), water contents (0.14 to 2.23 weight percent) and initial strontium isotope ratios (0.7028 to 0.7095) suggest a variety of source materials and identify rocks modified by secondary processes. Regular patterns of variation in each isotopic ratio exist over large geographical regions, but correlations between the ratios are generally absent except in restricted areas. For example, the regular decrease in δD values from west to east in the Sierra Nevada batholith is not correlative with a quite complex pattern of δ
18O values, implying that different processes were responsible for the isotopic variations in these two elements. In marked contrast to a good correlation between (87Sr/86Sr)o and δ
18O observed in the Peninsular Ranges batholith to the south, such correlations are lacking except in a few areas. δD values, on the other hand, correlate well with rock types, chemistry, and (87Sr/86Sr)o except in the Coast Ranges where few of the isotopic signatures are primary. The uniformly low δD values of samples from the Mojave Desert indicate that meteoric water contributed much of the hydrogen to the rocks in that area. Even so, the δ
18O values and 18O fractionations between quartz and feldspar are normal in these same rocks. This reconnaissance study has identified regularities in geochemical parameters over enormous geographical regions. These patterns are not well understood but merit more detailed examination because they contain information critical to our understanding of the development of granitoid batholiths.
TL;DR: Several wild-type virulent strains of Agrobacterium rhizogenes, belonging to both biotypes 1 and 2, were analyzed for plasmid content, finding that the plasmids of the various strains share rather extensive sequence homology.
TL;DR: Evidence that reduced cytochrome c 551 undergoes a pH transition is given by optical spectrophotometry and the nature of the transition is discussed in the context of recent nmr studies and in terms of the Marcus theory of electron transfer.
TL;DR: The present study shows that when strong sudom motor activity is induced in skin nerves by a rise in ambient temperature, the sudomotor impulses tend to occur in volleys time-locked to the cardiac cycle, a similar cardiac rhythmicity is not exhibited by the skin vasoconstrictor fibres which can be activated by lowering of the ambient temperature.
Abstract: In previous microelectrode recordings of sympathetic impulse activity in human peripheral nerves a marked cardiac rhythmicity has been found in the spontaneous firing of vasoconstrictor neurones supplying the vascular bed of skeletal muscles. Evidence has been presented that this rhythmicity depends on a potent baroreflex control of these neurones which are significantly involved in blood pressure regulation. In contrast, no cardiac rhythmicity has previously been seen in the spontaneous firing of sympathetic fibres supplying vessels and sweat glands in the human skin. The present study shows that when strong sudomotor activity is induced in skin nerves by a rise in ambient temperature, the sudomotor impulses tend to occur in volleys time-locked to the cardiac cycle. A similar cardiac rhythmicity is not exhibited by the skin vasoconstrictor fibres which can be activated by lowering of the ambient temperature. Induced falls in blood pressure do not produce any baroreflex modulations of the sudomotor outflow, suggesting that the cardiac rhythmicity of the sudomotor impulses is not dependent on the action of this reflex.
TL;DR: Experiments carried out on the cloned SSV genome show that v-sis is distinct from other viral transforming (onc) genes; and is to date the only onc gene of primate origin.
Abstract: The defective transforming simian sarcoma virus (SSV) and its nondefective helper virus (SSAV) are retroviruses isolated from a fibrosarcoma of a pet woolly monkey. Together with the gibbon ape leukaemia viruses, they are the only group of retroviruses known to cause spontaneous and experimentally induced neoplasia in primates (see refs 1 and 2 for review). Molecular cloning has shown that SSV contains a 1.2-kilobase (kb) transformation-specific viral onc gene (v-sis)3,4 which, like other viral onc genes, is derived from a set of conserved cellular DNA sequences5. A human DNA fragment containing sequences homologous to the entire v-sis gene has also been cloned and analysed6. We present here experiments carried out on the cloned SSV genome which show that: (1) v-sis is distinct from other viral transforming (onc) genes; and (2) v-sis is derived from a woolly monkey naturally infected once with gibbon ape leukaemia virus (GaLV) and is to date the only onc gene of primate origin.
TL;DR: Kinetic and thermodynamic features match each other, suggesting that a single ionizing group is responsible for all the observed effects.
TL;DR: The distribution of ADA activity has been studied for ADA 1 and ADA 2‐1 individuals in intact and lysed erythrocytes and in lymphocyte lysates.
Abstract: SUMMARY
The distribution of ADA activity has been studied for ADA 1 and ADA 2-1 individuals in intact and lysed erythrocytes and in lymphocyte lysates.
ADA activity in intact RBC is 20-30% lower than in lysates, in lymphocytes it is 10 times higher.
The difference between ADA 1 and ADA 2-1 mean enzyme activities which we previously described in RBC lysates has been found also in intact RBC and in lymphocyte lysates.
TL;DR: The Immunoadjuvant effect of CA and of other ‘classic’ immunoadjuvants, such as BCG and Corynebacterium parvum, was completely abolished by total-body irradiation (400 R) given 5 h before the first administration of the agent on day −7 prior to tumor challenge.
Abstract: Chemical, ultrastructural, and immunoadjuvant properties of Candida albicans (CA) and of a number of its fractions have been characterized through the analysis of the antitumor activity of soluble and insoluble cell wall components.
TL;DR: Oxygen isotherms of human hemoglobin measured in distilled water and in solutions of different inorganic salts in the concentration range from below 10−3 m to above 1·5 m at neutral pH indicate that the oxygen affinity decreases with increasing salt concentration in the lower range of ionic strength.
TL;DR: All asthmatic children should be investigated to check for a sinus disease, owing to the high prevalence of sinusitis in children with bronchial asthma.
TL;DR: Der-like immunoreactivity from neural tissue of Dosidicus gigas, Eledone moscata, and rat brain showed a good agreement with an authentic sample of synthetic Der, a natural peptide extracted from amphibian skin.
TL;DR: An inverse relationship appears to exist in the two types of tumour cells between the extent of cellular damage brought about by intracellular formation of superoxide anion occurring on reaction with O(2) of the drug free radical and the efficiency of the glutathione-mediated H( 2)O(2)-detoxifying system.
Abstract: Addition of 0.5mm-daunomycin, a quinone anti-cancer drug, causes severe inhibition of respiration in Ehrlich ascites cells, whereas Yoshida ascites cells were almost as resistant as rat hepatocytes. An inverse relationship appears to exist in the two types of tumour cells (which are both catalase-deficient) between the extent of cellular damage brought about by intracellular formation of superoxide anion occurring on reaction with O 2 of the drug free radical and the efficiency of the glutathione-mediated H 2 O 2 -detoxifying system.
TL;DR: The performances on semantic discrimination tests of patients showing a prevalence of phonetic, phonemic and verbal-semantic paraphasias, neologisms and anomia on confrontation naming tasks were compared and it was found that a very small number of semantic discrimination errors was obtained by patients show a prevalenceof phonetic and phonemic transformations on confrontation.
TL;DR: Preliminary results indicate that raised antibody dependent cell mediated cytotoxicity is a feature of insulin dependent diabetes at diagnosis and suggest that active B cell damage might be occurring some time before the onset of clinical symptoms.
Abstract: Antibody dependent cell mediated cytotoxicity in relation to the levels of circulating killer cells was investigated in 16 newly diagnosed classical insulin dependent (Type 1) diabetics, 11 islet cell antibody positive non diabetic children with at least one HLA haplotype in common with their diabetic sibling, and in 15 normal controls. Antibody dependent cell mediated cytotoxicity was evaluated using, as target, 51Cr labelled human 0+ erythrocytes sensitised with an anti-CD antiserum. Killer cells were measured by the low affinity E-rosetting cell technique. Increased killer cell levels (greater than normal mean + 2SD) were accompanied by a significant enhancement in antibody dependent cell mediated cytotoxicity both in newly diagnosed diabetics (p less than 0.05) and in unaffected siblings (p less than 0.01). These preliminary results indicate that raised antibody dependent cell mediated cytotoxicity is a feature of insulin dependent diabetes at diagnosis and suggest that active B cell damage might be occurring some time before the onset of clinical symptoms.
TL;DR: Odontites verna subsp.
TL;DR: The fatty acid composition of biliary phosphatidylcholine was analyzed in 13 patients with radiolucent gallstones undergoing elective cholecystectomy, and in 11 normolipemic patients without gall stones undergoing abdominal surgery, and there was no difference between the two groups.
Abstract: The fatty acid composition of biliary phosphatidylcholine was analyzed in 13 patients with radiolucent gallstones undergoing elective cholecystectomy, and in 11 normolipemic patients without gallstone undergoing abdominal surgery. The only difference in the percentage fatty acid composition between the two groups was a significantly (p less than 0.05) higher percentage arachidonic acid in the first group. This acid was exclusively located in the sn-2 position of phosphatidylcholine (PC), accounting for 13.0 +/- 4.9% in the first group and 8.2 +/- 4.9% in the second (p less than 0.05). The percentage arachidonic acid of PC was negatively correlated (p less than 0.001) with the percentage biliary chenodeoxycholate in gallstone patients, but not in controls. Explanation of these findings is, at present, only speculative.
TL;DR: In this article, the authors present problems about dynamical control of industrial robots performing high speed continuous movement are presented, where the influence of the control implementation via a discrete algorithm, of joint elasticity (neglected in the control design) and of parameter variation is evaluated by using simulation.
TL;DR: The findings indicate the presence of a cholinergic parasympathetic innervation in the human liver.
Abstract: The cholinergic innervation of the human liver was studied. Slices (150--200 micrometer thick) of human liver and of the greater hepatic blood vessels (hepatic artery and vein, portal vein) were incubated in a solution of 6-hydroxydopamine (6-HDA) in order to obtain a selective degeneration of adrenergic nerves. Controls were prepared from samples incubated with buffer alone. The slices were cut on a cryostat into 15-20 micrometer thick sections and processed for the histochemical detection of cholinesterases. Cholinergic nerve fibres innervate the extra hepatic and the intrahepatic branches of the hepatic artery, the portal vein as well as the hepatic vein. Fewer cholinergic fibres innervate the hepatocytes and the hepatic sinusoids. The 6-HDA treatment does not seem to alter the pattern of the cholinergic innervation of the liver. The findings indicate the presence of a cholinergic parasympathetic innervation in the human liver.
TL;DR: P pH effects on cooperativity are reversible, since this is not a common feature of the giant erythrocruorin molecules, and oxygen binding experiments revealed a marked effect of divalent cations of Amphitrite erystrocru orin at high pH and cation concentration.