Showing papers by "Sapienza University of Rome published in 1975"
TL;DR: Mitochondria from beef heart, Morris hepatoma 3924A and Ehrlich ascites tumor and Lettré mutant have been studied with respect to hydrogen peroxidase and superoxide radical formation and the presence of superoxide dismutase activity, appearing to be precursors of hydrogen peroxide formation.
259 citations
TL;DR: On the basis of the behavior of the isolated hemoglobin components from trout blood and of their distribution among the erythrocytes, it has been possible to provide a “rationale” for the existence of several hemoglobins.
Abstract: Publisher Summary The existence of specific carriers deputed to the transport of oxygen from the outer environment to the place of utilization is widespread in nature. Under the pressure of the variable oxygen requirements, a series of adaptive mechanisms involving the different “gears” of the machine deputed to the supply of oxygen to the tissues has come into operation. Allosteric effects have become apparent in studies on hemoglobins; those on the structural and functional properties of hemoglobins have been largely carried out on the proteins extracted from mammals. Contrary to the case in mammals and birds, a multiplicity of hemoglobin components is generally found in the blood of fish, reptiles, and amphibians. This chapter discusses the structural and functional properties of the various hemoglobin components of the blood of trout ( Salmo irideus ). On the basis of the behavior of the isolated hemoglobin components from trout blood and of their distribution among the erythrocytes, it has been possible to provide a “rationale” for the existence of several hemoglobins.
212 citations
TL;DR: In this article, a Monte Carlo calculation of the longitudinal and lateral development of photon-initiated electron-photon cascades in SF5 lead glass for the following energies of the primary photon: 100, 300, 500, 700, 1000, and 5000 MeV is presented.
143 citations
TL;DR: The results fit very well with data previously obtained with other methods and show that this polarographic procedure can be used under conditions that render the other methods unsuitable for the measurement of the enzyme activity.
142 citations
TL;DR: The pharmacological activity of two natural bombesin‐like peptides, alytesin and litorin, and 25 related synthetic peptides has been compared to that of bombsin and both the tryptophan and histidine residues seemed to be essential for bombesIn‐like activity.
Abstract: The pharmacological activity of two natural bombesin-like peptides, alytesin and litorin, and 25 related synthetic peptides has been compared to that of bombesin 2 The minimum length of the amino acid chain required for the first appearance of bombesin-like effects was represented by the C-terminal heptapeptide, and the minimum length for maximal effects by the C-terminal nonapeptide The latter possessed approximately the same activity as bombesin and may be considered a good substitute 3 Both the tryptophan and histidine residues seemed to be essential for bombesin-like activity 4 The C-terminal octapeptide was less active than either bombesin or the C-terminal nonapeptide and its action was more rapid in onset and less sustained 5 Litorin apparently has an intermediate position between bombesin octapeptide and bombesin nonapeptide in the speed and duration of its effects The relationship between structure and activity is discussed
136 citations
TL;DR: The authors favor radical surgery, believing that carotid ligation does not provide assurance against the risk of rebleeding, and frequently is associated with failure to restore useful vision.
Abstract: A surgeon who has to treat carotid-ophthalmic aneurysms is confronted with several problems, some common to all aneurysms and others peculiar to aneurysms of this site. The first problem, common to all intracranial aneurysms, hinges on the patient’s condition (grade I–V) and the length of the interval between hemorrhage and surgery. The second problem is what to do with a patient who has a subarachnoid hemorrhage from another aneurysm and who is found incidentally to have a carotid-ophthalmic aneurysm. The third problem is whether to opt for direct or indirect surgery by closure of the carotid at the neck.
106 citations
TL;DR: This short-term trial confirms previous uncontrolled experiences of one of the authors on larger series of patients with acute proctocolitis, and produces significant improvement in clinical symptoms, some laboratory findings, and endoscopic and biopsy findings.
Abstract: A double-blind therapeutic trial of azathioprine in 20 patients with acute proctocolitis was performed over a 3-month period. Azathioprine was compared with sulfasalazine in patients paired and treated in a sequential order. Clinical, laboratory, endoscopic, biopsy, and radiologic data were assessed by semiquantitative criteria. No significant difference in the effect of the drugs was observed. Both azathioprine and sulfasalazine produce significant improvement in clinical symptoms, some laboratory findings (ESR, serum iron), and endoscopic and biopsy findings (P<0.05). Radiologic improvement was less evident (P<0.10). On the overall final evaluation of the trial, 14 patients were improved, and 6 remained stationary or worsened (P<0.10). This short-term trial confirms previous uncontrolled experiences of one of the authors on larger series of patients.
94 citations
TL;DR: The SEM results and parallel TEM observations suggest that a local increase of fluids (edema) may be an important factor in the final decomposition of the distended and weakened apex of the preovulatory follicle.
Abstract: Ovulation involves a series of timed hormonal biochemical and morphological events. This study demonstrated by scanning electron microscopy (SEM) the process of ovulation. Ovaries from 35 mice 15 rats and 12 rabbits were studied. The animals had not received exogenous hormone to induce ovulation. After removal at the proper phase of the estrous cycles ovaries were prepared for SEM and for parallel transmission electron microscopy (TEM). Details of methods used were given. By SEM preovulatory follicles were seen as blisterlike structures protruding from the ovarian surface. Numerous "papillae" were observed around some of these forming a "flowerlike bouquet." The superficial epithelium of the ovaries with cuboidal or polyhedral cells having numerous microvilli was present only about the base of the preovulatory follicles. The apices of preovulatory follicles had areas of flattened cells with few short microvilli. Some showed degeneration and desquamation revealing an amorphous connective tissue stroma beneath. Many spherical or ovoidal blebs were seen on the surface at the aspices of preovulatory follicles. By TEM amorphous fluidlike material was seen in the connective tissue of the tunica albuginea the intercellular spaces under basal lamina and in vacuoles in the cytoplasm of many superficial cells. At ovulation areas at the apex of the follicle ruptured. Large amounts of fluid (liquor folliculi) and tissue debris were then present obscuring images of ovulated oocytes. The zona pellucida was a dense amorphous membrane cov ered with fine granules similar to those seen in the cells of the corona radiata. It seems that the increase in fluids (edema) may be a major cause of the progressive changes of tissues occurring in the apical zone of the preovulatory follicley Vascular changes in the perifollicular ar eas may also occur. Ovulation seems to be a gradual process in which the oocyte immersed in the gellike material of the liquor folliculi escapes from the ruptured surface of the ovary. The nature of any expulsive force is controversial. Also the composition and function of the granular materials seen on the surface of corna cells and zona pellu cida remain obscure. The text are 9 plates with explanations of appearances.
62 citations
TL;DR: The observation that negative intrathoracic pressure alone seems to promote resorption of FPF under the conditions of the experiments suggests that this may be an important mechanism for the formation of the air-lung at birth.
Abstract: An indicator-dilution method is described for measuring fetal pulmonary fluid, FPF, volume (Ve), and volume change with time (Vs) in the lamb fetus in utero. The indicator, albumin, which is the predominant protein of normal FPF, was administered directly to FPF in the form of radio-iodinated human serum albumin (RISA). We have shown that (1) RISA is distributed homogeneously throughout the FPF compartment, (2) it is not altered within FPF, (3) it does not alter the functional characteristics of FPF, and (4) it remains within the FPF compartment throughout the period of measurement. Ve varies directly with the weight of the fetus so that Ve per kilogram was 31.6-35.6 ml/kg in four of five fetuses. The Ve per kilogram was lower in one fetus at the start of the experiment but increased rapidly to 29.0 ml/kg within 45 min. Thus the relaxation volume of the fetus in utero is in the range of functional residual capacity (FRC) and thoracic gas volume of the air-breathing neonate, which indicates that the pulmonary transformation at birth is, in essence, an isovolumic change in state wherein the fetal liquid-lung becomes the neonatal air-lung. The rate at which FPF is formed (Vs) is about 1.5 ml/hr-kg; however, the rate may change in so far as both rapid increases and rapid decreases of FPF volume were observed. When breathing movements were induced in the fetus by stimulation of the sciatic nerve, FPF volume decreased rapidly (Vs equals -3.0 ml/hr-kg), which indicates that negative intrathoracic pressures promote its resorption. When FPF volume fell transiently or was low initially, there was subsequent rapid restoration of volume to the range of anticipated FRC.
59 citations
TL;DR: In this paper, the surface ultrastructure of Kupffer cells in the rat liver has been studied by scanning electron microscopy (SEM) and the results demonstrate that KUPffer cells are both significantly different and clearly distinct from endothelial cells.
Abstract: The surface ultrastructure of Kupffer cells in the rat liver has been studied by scanning electron microscopy (SEM). The results demonstrate that Kupffer cells are both significantly different and clearly distinct from endothelial cells. Kupffer cells have neither pores (and/or “sieve plates”) nor fenestrations, all of which are present in endothelial cells. They possess a stellate shape, and only indirectly, with slender and irregular evaginations, contribute to the lining of the sinusoidal wall. Furthermore, the luminal surface in some areas contains a large population of short microvilli, microplicae and invaginations. These elements form a kind of microlabyrinth which may correspond to the “worm-like” structures described by transmission electron microscopy (TEM).
55 citations
TL;DR: In this article, the inner sphere mechanism for the reaction between O2− and copper was investigated and inhibition by OH− and CN− was shown to be of the competitive type.
TL;DR: It is discussed that the Sertoli cells play a key role in the antispermatogenic action of AF 1312TS and early cytoplasmic and nuclear alterations are also observable in the SERToli cells.
TL;DR: The polarographic method of the kinetic currents is applied to kinetic studies of the dismutation of O, which allows the determination of the rate constants by a very simple procedure and presents some advantages with respect to pulse radiolysis.
TL;DR: Isolation due in part to cultural factors, genetic drift, and special local or regional patterns of villages associations appear to be involved in the pattern of genetic variation.
Abstract: The present study reports an analysis of genetic differentiation among 14 Sardinian villages located mainly in the center of the island. Chi-square tests show significant genetic heterogeneity among villages, and analyses by F- and R- statistics indicate an essentially random pattern of differentiation for all alleles. Using the kinship methods of Morton, a matrix, R, with elements rij describing the correlations between the gene frequencies of villages i and j is obtained. Use of Malecot's formula relating the rij to the geographic distances between villages shows a rapid decline of kinship with increasing distance but reveals essentially no relationship for distances over 40 km. Rotation of a two-dimensional reduction of the kinship matrix to maximum congruence with the geographic distances indicates that about 25% of the genetic distances can be accounted for by the geographic location of the villages. Isolation due in part to cultural factors, genetic drift, and special local or regional patterns of villages associations appear to be involved in the pattern of genetic variation.
TL;DR: The characteristic electric changes of PP produced byBombesin appear to be related to the sequence of the nine amino acids in the COOH-terminal residue of the bombesin molecule.
TL;DR: In this article, 13C/12C and 18O/16O ratios have been measured for 42 marbles from the main quarry localities of archaeological interest of Western Anatolia (Marmara, Ephesos, Aphrodisias, Denizli and Afyon) in order to test the possibility of isotopically characterizing ancient marbles.
Abstract: 13C/12C and 18O/16O ratios have been measured for 42 marbles from the main quarry localities of archaeological interest of Western Anatolia (Marmara, Ephesos, Aphrodisias, Denizli and Afyon) in order to test the possibility of isotopically characterizing ancient marbles from this region. The various groups of samples are not clearly distinguishable on a δ13C-δ18O diagram. However, if only white or slightly coloured samples are considered, the isotopic method appears to be much more selective.
TL;DR: It appears that very large proteins, in contrast to small proteins, may be frozen in vivo in a conformation that does not correspond to a minimum in free energy.
TL;DR: This work has shown that iontophoretically released GABA is a putative inhibitory neurotransmitter in some structures of cat central nervous system and the action of the drug was applied extracellularly on rat caudate neurones whose activity was recorded intracellularly and extrace cellularly.
TL;DR: The effect of several anions on the oxygen equilibrium of hemoglobin components (Hb Trout I, II, and IV) from trout has been investigated in this article, showing that the functional properties of Hb trout I and II are very slightly affected by organic phosphates (ATP, IHP) and pyridoxal phosphate.
TL;DR: It seems obvious that the same side of an hepatocyte may be used for bounding two or more bile canaliculi in the rat liver.
Abstract: Bile canaliculi in the rat liver have been studied by scanning electron microscopy. They appear as half tubules carved out of the hepatocytes' surface. In several cases the bile channel bifurcates to form two or three long branches running on the same face of the cell. Therefore, by SEM it seems obvious that the same side of an hepatocyte may be used for bounding two or more bile canaliculi. Some bile canaliculi display a flexuous course and show lateral sacculations. Some of them are large and apparently similar to the short lateral branches of the bile canaliculus; others are smaller and arise obliquely from the subjacent cortical areas of the hepatocyte cytoplasm. These latter structures are best observed in stereo-views in which they appear as narrow intracellular projections bordered with a few microvilli, actually opening into the lumen of the bile canaliculus. The SEM results suggest that these sacculations probably correspond to short intracellular branches of the bile canaliculi. Zones of minimal distance (0.1 mu) between the space of Disse and the bile channel have been frequently observed. They are actually the zones where the intercellular clefts arising from the subendothelial space of Disse come into closet contact with the bile canaliculus and might serve as sites of simple diffusion of substances.
TL;DR: In this paper, the authors suggest that policy analysis should concentrate on the investigation of the conditions of feasibility of public programs, and that the most important task of policy analysis consists in submitting plans and objectives to the most stringent tests of feasibility.
Abstract: The notion that, given sufficient ingenuity and resources, any social problem can be solved, in a manner consistent with the announced policy objectives and with the accepted institutional framework, has been a major source of failures and frustrations. This paper suggests that policy analysis should concentrate on the investigation of the conditions of feasibility of public programs. Feasibility is defined in terms of all the relevant constraints: social, political, administrative, and institutional, as well as technical and economic. The emphasis on the pure logic of choice and optimal decision rules, so characteristic of normative theorizing in decision theory, management science, and welfare economics, has tended to obscure the fact that in the field of social policies, the range of feasible choices is severely limited by a variety of constraints. Most “bad” decisions are not just suboptimal; on closer examination, it usually turns out that they were not even feasible at the time they were made. Only by understanding the reasons why, under certain circumstances, a given goal cannot be achieved, can we hope to gain better knowledge about the working of social institutions. Just as the essence of the scientific method is the critical analysis and refutation of proposed theories, rather than the accumulation of evidence in favor of pet solutions, so the most important task of policy analysis consists in submitting plans and objectives to the most stringent tests of feasibility. Also in analytic case studies, the search for constraints that were ignored by the decisionmakers has considerable heuristic value, as I try to demonstrate with a critical discussion of some aspects of the British National Health Service.
TL;DR: It is shown that the changes in the optical and the EPR spectrum of ascorbate oxidase induced by nitric oxide are reversible.
TL;DR: The method, when compared to others adopting the same electrode, is recommended for its simplicity, accuracy, and rapidity.
TL;DR: The data suggest that the gradient for malaria morbidity directly or indirectly, through interactions with thalassemia and G6PD polymorphisms, may have had a significant role in determining the heterogeneous distribution of acid phosphatase polymorphism in Sardinia.
Abstract: The frequency of PC allele for acid phosphatase in fourteen Sardinian villages correlates positively with the altitude and negatively with past malarial morbidity and GdMed prevalence.
The susceptibility towards hemolytic favism in Sardinian males with G6PD deficiency is dependent on the erythrocyte acid phosphatase and thalassemia phenotypes. Thalassemia trait exerts a protective action only in subjects carrying PA allele for acid phosphatase.
The data suggest that the gradient for malaria morbidity directly or indirectly, through interactions with thalassemia and G6PD polymorphisms, mediated by the habit of eating Vecia faba, may have had a significant role in determining the heterogeneous distribution of acid phosphatase polymorphism in Sardinia. Besides malaria, other environmental factors related with altitude seem to have been very important in shaping the present pattern of distribution of both acid phosphatase and G6PD polymorphisms in Sardinia.
TL;DR: A causal relationship exists between the metabolic acidosis induced by acetazolamide and by other drugs that have a blood-acidifying effect as the result of other mechanisms, and ocular hypotension, both in the animal and in the glaucomatous patient.
TL;DR: These studies indicate that PC is cleared rapidly from FPF with an estimated half-time of 15–57 min; FPF-PC may be metabolized to lyso-PC and FA within the fluid itself; and FA derived from FPf-PC enter the pulmonary circulation, thus establishing a pulmonary arteriovenous FA gradient.
Abstract: Using the radio-iodinated human serum albumin ([131-I]-RISA) dilution method to measure lamb fetal pulmonary fluid (FPF) volume, we followed the disappearance of protein-complexed, 14-C-labeled phosphatidylcholine ([14-C]PC) during the first 90 min after its injection into FPF. The FPF samples were analyzed for total lipid 14-C activity and for distribution of 14-C in PC, other phospholipids (PL), fatty acids (FA), and neutral lipids (NL). For most sampling periods ascending aortic (AAo) and right atrial (RA) blood samples were obtained simultaneously with FPF and serum was analyzed for total lipid 14-C activity and for distribution of 14-C in total PL, FA, and NL. These studies indicate that (1) PC is cleared rapidly from FPF with an estimated half-time of 15-57 min; (2) FPF-PC may be metabolized to lyso-PC and FA within the fluid itself; and (3) FA derived from PFP-PC enter the pulmonary circulation, thus establishing a pulmonary arteriovenous FA gradient. The possible sites at which PC may be cleared from FPF are considered.
TL;DR: Oxygen and strontium isotope analyses have been obtained for minerals of some ejected blocks found in the Albano “peperino”, one of the largest pyroclastic formations of the Alban Hills volcanic district, Roman comagmatic region as discussed by the authors.
Abstract: Oxygen and strontium isotope analyses have been obtained for minerals of some ejected blocks found in the Albano “peperino”, one of the largest pyroclastic formations of the Alban Hills volcanic district, Roman comagmatic region. Also analyzed for 87Sr/86Sr were one leucititic lava and one pyroclastic rock from this same area.
TL;DR: Litorin proved to be more potent than bombesin on isolated smooth muscle preparations and on the urinary bladder in situ, however, it was less potent on dog systemic blood pressure and kidney vasculature, activation of the renin‐angiotensin system being slight or lacking.
Abstract: The spectrum of biological activity exhibited by litorin, a bombesin-like nonapeptide found in extracts of the skin of the Australian leptodactylid frog Litoria aurea was compared with that exhibited by the tetradecapeptide bombesin. 2 Litorin proved to be more potent than bombesin on isolated smooth muscle preparations and on the urinary bladder in situ. However, it was less potent on dog systemic blood pressure and kidney vasculature activation of the renen-angiotensin system being slight or lacking. 3 Gastrin release and acid secretion produced by litorin was more rapid in onset but less intense and less sustained than that elicited by bombesin. The same could be observed for pancreatic secretion. 4 Gall bladder contraction stimulated by litorin was probably caused by a double action of the peptide, directly on the bladder smooth muscle, and indirectly by cholecystokinin release. 5 In its effects on the myo-electric activity of the dog duodenum (inhibition of spikes and increase in frequency of pacesetter potentials leading to the appearance of a sequence of slow and small potentials) litorin possessed approximately 50 to 70% of the activity of bombesin.
TL;DR: The analysis of the data showed that the condition of lymphocyte depletion was associated in HD patients with the highest anti‐EBNA antibody levels and the lymphocyte predominance with the lowest, which suggests that different mechanisms are probably responsible in HD for the release of EBV‐related antigens from infected cells.
Abstract: Antibody reactivity to Epstein-Barr virus (EBV)-associated nuclear antigen (EBNA) was investigated by means of the anticomplement immunofluorescence technique on sera from patients with Hodgkin's disease (HD) and from appropriate controls. Antibody levels to other EBV-determined antigens, i.e. viral capsid (VCA) and early antigens (EA), and to measles and rubella viruses, to cytomegalovirus (CMV), and to toxoplasma gondii were also measured. The results of anti-EBV antibody titrations demonstrated that anti-VCA, anti-EA and anti-EBNA reactivity was significantly higher in HD patients than in healthy subjects. There was no significant difference between the distribution of high rubella and measles antibody titers in HD and control sera. The GMT and the incidence of high titer anti-CMV and toxoplasma antibodies were greater in HD patients than in controls. The analysis of the data, according to histological subtypes, showed that the condition of lymphocyte depletion was associated in HD patients with the highest anti-EBNA antibody levels and the lymphocyte predominance with the lowest. This pattern seemed to be peculiar for anti-EBV reactivity, since anti-CMV and anti-toxoplasma antibody levels in the lymphocyte-depleted group of patients did not significantly differ from those of controls. No correlation was found between anti-VCA and anti-EBNA in individual sera of HD patients. This observation suggests that different mechanisms are probably responsible in HD for the release of EBV-related antigen from infected cells.