Showing papers by "University of Milan published in 1969"
TL;DR: Blocking of the α-amino groups by cyanate inhibits the uptake of CO2 by haemoglobin and inhibits the influence which changes in pCO2 at constant pH normally have on the oxygen affinity and on the Bohr effect.
Abstract: Blocking of the α-amino groups by cyanate inhibits the uptake of CO2 by haemoglobin. It also inhibits the influence which changes in pCO2 at constant pH normally have on the oxygen affinity and on the Bohr effect. Blocking the α-amino groups of the α chain reduces the alkaline Bohr effect by 25 per cent.
234 citations
166 citations
TL;DR: It was found that the right hemisphere-damaged patients were specifically impaired on the Meaningless Sounds Test, while the left hemisphere-Damaged were specifically impairing on the meaning of sounds test, which was found to be highly significant.
98 citations
TL;DR: The data suggest that the old + gene of P 2 inhibits lysogenization of lyd cells by making all infected lyd Cells inviable and that the phenomenon does not depend on an abnormal immunity or on a failure in the process of attachment of the phage to the host chromosome.
69 citations
TL;DR: The spinal ganglia of the fowl have been studied from the third incubation day to the adult.
Abstract: The spinal ganglia of the fowl have been studied from the third incubation day to the adult.
The neuroblasts are the first cells that differentiate in the ganglionic anlage. Satellite cells, probably arising from the undifferentiated elements scattered among the neuroblasts, become detectable during the fifth incubation day. They appear starshaped with attenuated cytoplasmic expansions intervening between adjacent neuroblasts. At this time the neuroblasts largely outnumber the satellite cells.
From the sixth incubation day connective tissue spaces, appearing as large intercellular gaps containing an amorphous material, become evident between satellite cells. During the second half of the incubation period each nerve cell is completely enveloped by a satellite cell sheath, which is in turn entirely surrounded by a connective tissue space. The satellite cells change in shape from star-shaped to flat elements. By this time and even more so in adult life, satellite cells outnumber nerve cells.
The satellite cells increase progressively in number, up to the ninth incubation day mainly through differentiation of undifferentiated cells; but later on by mitotic reproduction of fully differentiated satellite cells.
The neuron-satellite cell boundary becomes more and more complicated with time, thus enlarging in parallel with the increase in volume of the nerve cell. Adhering junctions may be observed along this boundary.
The significance of the ergastoplasm, centrioles and cilia of the satellite cells is briefly discussed. Numerous adhering and scarce occluding junctions, some of which are temporary, link satellite cells.
59 citations
TL;DR: The hypothesis is that the persistent increase in wakefulness and reduction of sleep (synchronized and desynchronized), induced by these cuts, may be ascribed to suppression or reduction of the flow of physiological sleep impulses originating in regions at the level of the pontine section or caudally to them, and ascending contralaterally to diencephalic and cortical regions.
57 citations
57 citations
TL;DR: It is shown recently that the arterial hypotension occurring during DS is dependent chiefly on a decreased peripheral resistance, change in cardiac output being small, and it has been suggested3, though not demonstrated, that the decrease in peripheral resistance might result from a reduction of sympathetic vasoconstrictor activity.
Abstract: IN the past few years there has been increasing interest in cardiovascular changes during sleep, on the assumption that they might provide some insight into the neural control of circulation in a natural condition. The hypothesis that all cardiovascular events that occur during sleep are neurally mediated has never been crucially proved, however. Furthermore, sleep is accompanied by various haemodynamic phenomena which may well have different mechanisms. In the cat the greatest cardiovascular changes occur during desynchronized sleep (DS)1,2, a stage of sleep characterized by a desynchronized electroencephalogram and bursts of rapid eye movements, and in man associated with dreaming. We have shown recently that the arterial hypotension occurring during DS is dependent chiefly on a decreased peripheral resistance, change in cardiac output being small3. This is particularly true for animals subjected to sino-aortic deafferentation3, whose hypotension during DS is greatly exaggerated because of the removal of a buffer action exerted by arterial chemoceptors4. But in the few DS episodes during which hypotension is so profound as to cause electroencephalographic signs of cerebral anoxia (a phenomenon observed in deafferented animals only), the very large decrease in arterial pressure seems to be exclusively a consequence of a dramatic fall in cardiac output3. It has been suggested3, though not demonstrated, that the decrease in peripheral resistance might result from a reduction of sympathetic vasoconstrictor activity. The decrease in cardiac output, which is independent of cardiac innervation3,5, may also be a consequence of a reduction of sympathetic activity resulting in a dilatation of capacitance vessels and a decreased venous return, although non-neural mechanisms may well be involved.
51 citations
TL;DR: Findings from a tactual test of shape discrimination are interpreted as pointing to a major representation of spatial abilities in the posterior cerebral area, especially of the right hemisphere, regardless of whether the sense information is conveyed through the visual or the tactual modality.
50 citations
TL;DR: Findings support the view that the posterior areas of the minor hemisphere are crucial in the processing the visual stimuli, regardless of their quality (i.e., verbal or non-verbal).
TL;DR: The hydrogen transfer from alcohols or alkoxides to olefins is catalysed by the RhCl 3 -tertiary phosphines system as discussed by the authors, and the change in the catalytic activity with the nature of the phosphines have been correlated with the ability of Rh 0 phosphine complexes to abstract hydrogen from alkoxide.
TL;DR: Myelination was retarded by treatment with AY‐9944 and 20, 25‐diazasterol, possibly by the limited amount of sterols available, and the metabolism of the abnormal myelin constituents in drug‐treated animals is discussed in relation to the molecular structure of the myelin membrane.
Abstract: — Three drugs known to inhibit biosynthesis of cholesterol, Clofibrate, 20, 25-diazacholesterol and AY-9944 were administered by stomach intubation to suckling rats. At weaning the rats were killed and subcellular fractions, including myelin, were prepared from the brains and spinal cords and analysed for sterol content. Central nervous tissue fractions from Clofibrate-treated rats showed some decrease in total sterols, but the sterol species were qualitatively normal. AY-9944 given to rats caused high amounts of 7-dehydro-cholesterol to accumulate in all brain and spinal cord fractions with the highest amounts (32–38 percent of total sterols) in myelin. In diazasterol-treated rats desmosterol reached 48 per cent of the sterols of myelin. A group of rats was allowed to survive after the final drug intake (21 days) and their brain and spinal cord sterol content followed up to 60 days. At 30 days the proportion of dehydrocholesterol or desmosterol comprised over half the total myelin sterol. By 60 days of age the 7-dehydrocholesterol had almost completely disappeared from all fractions while substantial amounts of desmosterol were retained in myelin. Myelination was retarded by treatment with AY-9944 and 20, 25-diazasterol, possibly by the limited amount of sterols available. The metabolism of the abnormal myelin constituents in drug-treated animals is discussed in relation to the molecular structure of the myelin membrane.
TL;DR: Les auteurs emettent l'hypothese que l'exposition au benzene peut avoir induit des fragmentations and des rearrangements chromosomiques dans une cellule souche qui, en proliferation, produisait le clone erythroleucemique anormal.
TL;DR: The general pattern of amino acid transport in isolated cardiac cells was similar to that found in intact hearts, suggesting that the biological preparation described in this paper might be useful for studies of cell permeability and insulin action.
Abstract: 1. The preparation of cell suspensions by treatment of chick embryo hearts with collagenase at various stages of development is described. 2. Measurements of oxygen consumption, incorporation of labelled leucine into protein and accumulation of labelled α-aminoisobutyric acid against a concentration gradient indicated a long-lasting viability of the isolated heart cells in vitro; a satisfactory preservation of subcellular structures, including plasma membrane, was assessed by electron-microscopic examination. 3. The rate of α-aminoisobutyric acid accumulation by cardiac cells isolated from hearts at different stages of embryological development decreased with aging; insulin stimulated the intracellular accumulation of this amino acid analogue. 4. Insulin increased the uptake by isolated heart cells of several 14C-labelled naturally occurring amino acids; however, the fraction of amino acid taken up by the cells that was recovered free intracellularly, and therefore the concentration ratio (between intracellular water and medium), was enhanced by the hormone only with glycine, proline, serine, threonine, histidine and methionine. When isolated heart cells were incubated in the presence of a mixture of labelled amino acids, the addition of insulin increased the disappearance of radioactivity from the medium. 5. The general pattern of amino acid transport (in the absence and in the presence of insulin) in isolated cardiac cells was similar to that found in intact hearts, suggesting that the biological preparation described in this paper might be useful for studies of cell permeability and insulin action.
TL;DR: In unanesthetized, unrestrained cats, placed in a sound-attenuated cage, stroke volume and cardiac output were continuously monitored by an electromagnetic flow transducer chronically implanted around the ascending aorta, and total resistance was computed by dividing arterial pressure by cardiac output.
Abstract: In unanesthetized, unrestrained cats, placed in a sound-attenuated cage, stroke volume and cardiac output were continuously monitored by an electromagnetic flow transducer chronically implanted around the ascending aorta, arterial pressure was measured by means of a femoral catheter connected to a strain-gauge transducer, and heart rate by a cardiotachograph. Total resistance was computed by dividing arterial pressure by cardiac output. Electroencephalograms, cervical electromyogram, and ocular movements were also monitored to obtain evidence of naturally occurring sleep. In animals with intact sinoaortic reflexes the fall in arterial pressure occurring during desynchronized sleep was associated with a small decrease in cardiac output and a relatively greater reduction in total resistance. After sinoaortic deafferentation, the conspicuously exaggerated fall in arterial pressure occurring during the same type of sleep was almost entirely due to a parallel exaggeration of the reduction in total resistance; changes in cardiac output were only slightly greater than before deafferentation. Only in the few episodes of desynchronized sleep in which extreme hypotension was accompanied by signs of cerebral anoxia, did cardiac output greatly decrease; in these cases, calculated resistance was found to increase. Both small and large changes in cardiac output were independent of heart innervation.
TL;DR: The geometry of the CH+5 ion has been investigated using semi-empirical LCAO SCF (CNDO/2) method in this article, and a configuration with Cs symmetry has been found to be the most stable.
TL;DR: The tetramethylammonium salt of the triacontacarbonyldodecarhodate dianion [N(CH3)4]2[Rh12(CO)30] has been determined from three-dimensional X-ray data collected by counter methods as discussed by the authors.
TL;DR: Enrico C. Vigliani, M.D., is the recipient of the 1969 William P. Yant Memorial Award as mentioned in this paper, which was presented under the auspices of the American Industrial Hygiene Association.
Abstract: The William P. Yant Memorial Award was established shortly after the death of Dr. Yant, to commemorate his dedicated years of service and pioneering achievements in industrial hygiene. He was for many years affiliated with the Mine Safety Appliances Company, becoming Director of Research and Vice President, and in memory of this service the company sponsors and supports this award under the auspices of the American Industrial Hygiene Association. The award is presented to a person from outside the United States who is outstanding in one or more of the industrial health sciences. The first award was presented in 1965. Enrico C. Vigliani, M.D., is the recipient of the 1969 William P. Yant Memorial Award. Dr. Vigliani is Director and Chairman of the Institute of Occupational Health “L. Devoto” of the Medical Faculty, University of Milano, Italy. Dr. Vigliani is widely recognized for the excellence and the breadth of 'the toxicological research which has been done in his laboratories. A leader in thi...
TL;DR: The activity of the ribonuclease was found to increased rapidly in Avena leaf tissue in association with injury and/or senescence and has a preference for the secondary phosphate esters of 3′-GMP.
TL;DR: Unusual membrane-particle complexes, occasionally observed within the neuronalperikaryon in spinal ganglia of the guinea pig and rabbit, closely resemble those observed in other kinds of cells under normal, experimental, or pathological conditions.
TL;DR: In this paper, the LCAO SCF molecular orbitals and energies of H2S were computed using a minimal basis set augmented by sulphur 3d orbitals with optimized 1s H and 3d orbital exponents.
Abstract: LCAO SCF molecular orbitals and energies of H2S are computed using a minimal basis set augmented by sulphur 3d orbitals and with optimized 1s H and 3d orbital exponents. The dissociation energy, the electric dipole moment, the two independent field-gradient components at the sulphur nucleus and some transition energies are calculated and compared with the experimental quantities.
TL;DR: Anthocyanins present in the aleurone layer in Pr colour genotypes of Zea mays are cyanidin 3-glucoside and two unstable acylated derivatives of this pigment.
TL;DR: Differential cross sections for (p, α) reactions at E p = 38 MeV have been obtained for 9 Be, 11 B, 12 C, 16 O and 19 F as mentioned in this paper.
TL;DR: Some typical aspects of the cuticle and cortex of normal hair and the changes present in bamboo hair and Monilethrix are described with the aid of a scanning electron microscope.
Abstract: Some typical aspects of the cuticle and cortex of normal hair and the changes present in bamboo hair and Monilethrix are described with the aid of a scanning electron microscope. It is suggested that these two malformations of the hair may arise because the maturation processes of cuticle and cortex get out of step with one another.
TL;DR: In this article, the anodic behavior of titanium in methanolic solutions containing halides or water in various concentrations has been investigated and the result were compared with the result obtained by corrosion tests performed on „U” bend specimens in similar solutions.
Abstract: Untersucht wurde das anodische Verhalten von Ti in halidhaltigen methanolischen Losungen (bzw. in Methanol mit Wasser in verschiedenen Konzentrationen); die Ergebnisse wurden verglichen mit den Ergebnissen, die mit U-formigen Proben in ahnlichen Losungen erhalten worden waren. Polarisationskurven ermoglichen Aussagen uber Anfalligkeit von Ti fur Spannungsriskorrosion, da die Metalloberflache in diesem Falle nicht passivierbar ist. Die Voraussetzungen hierfur sind niedriger Wassergehalt (z.B.0,1%) und Anwesenheit aktivierender Ionen (z.B. Chlorid oder Bromid) auch in sehr geringen Konzentrationen (10−5 oder 10−4m). Hohere Wassergehalte oder/und Anwesenheit von Fluoriden und Jodiden konnen die Metalloberflache in gewissem Umfang passivieren, so das dann keine Risbildung eintritt. Sehr niedrige Wassergehalte in der Losung (z. B. 130 ppm) unterbinden die Passivierung in der Metalloberflache, so das auch in Abwesenheit von Chloriden oder Bromiden Risbildung eintreten kann. Hohe Chloridkonzentrationen (z. B. 0,1 m NaCl + 0,1% Wasser) konnen auch ohne mechanische Belastung zu interkristallinem Angriff fuhren.
Anodic behaviour and corrosion of titanium in methanolic solutions
The anodic behaviour of titanium in methanolic solutions containing halides or water in various concentrations has been investigated and the result were compared with the result obtained by corrosion tests performed on „U” bend specimens in similar solutions. Polarization curves can predict the susceptibility to titanium to stress corrosion cracking as in the case the metal surface is not passivable. These conditions can be obtained in the presence of low water content (i.e. 0.1% H2O) and of activating ions as Cl− and Br− even in very small concentration (105−, 104− M). Presence of higher water contents and/or of F− or I− ions can to some extent produce passivation of the metal surface and cracking does not occur. A lower water amount in the solution (i.e. 130 ppm) eliminates any possibility of passivation of the metal surface, so that cracking can occur even in the absence of chlorides or bromides. High Cl− concentration in the solution. (i.e. 0.1 M NaCl + 0.1% H2O) can produce intergranular attack even in the absence of applied stress.
TL;DR: In this article, the authors applied the molecule in molecules (MIB) method to five groups of hydrocarbon molecules or ions and compared the energy, polarisation and intensity of electronic transitions with experimental data and previous theoretical results.
Abstract: The “molecules in molecules” method has been applied to five groups of hydrocarbon molecules or ions. Energy, polarisation and intensity of electronic transitions have been compared with experimental data and previous theoretical results. The results show that the method is applicable even when there is relevant conjugation between the fragments.