Showing papers by "Sapienza University of Rome published in 1968"
TL;DR: The maintenance of order and balance—homeostasis, as the physiologist would have it—is an attribute of all living things and is a central theme of Biophysics.
Abstract: Mηδέν ἄγαν—nothing in excess. These words of the old Greek saying might well find a place in modern Biology. The maintenance of order and balance—homeostasis, as the physiologist would have it—is an attribute of all living things. At a molecular level the study of control and regulation, involving the conjugate concepts of structure and function is a central theme of Biophysics. How is it that an enzyme, by the braking effect of its end products, is prevented from going too far, or, alternatively, by the accumulation of other metabolic substances in its environment, is brought into play? How is it that a working respiratory protein like haemoglobin, by the reciprocal action of its metabolic opposite, carbon dioxide, is aided in the taking up of oxygen in the lungs and the giving it off in the tissues? These are problems of linkage. From one point of view they may be thought of in terms of information— the communication between ligand and macromolecule and between one part of the macromolecule and another. From a different point of view they may be thought of in terms of the storage and transfer of energy, of the way in which the work of introducing ligand, the same or different, at another. The analysis may be pitched either at the phenomenological, or at the mechanistic, level; but whatever the approach it profits cosiderably from the introduction of the concept of the binding potential.
153 citations
TL;DR: The dissociation of normal human oxyhemoglobin has been studied by gel filtration under conditions of neutral pH and moderate ionic strength, with the use of both integral boundaries, formed between solution and solvent, and finite difference boundaries,Forms a simple dimer-tetramer reversible equilibrium and a monomer-dimer-trimer-tetic reversible equilibrium.
121 citations
TL;DR: The profile of the curve relating the ΔpK′ to the percent alkylation suggests the possibility of dividing the different reactive groups of the protein into different classes on the basis of their effects on the ionization process.
96 citations
78 citations
TL;DR: Following two of the cases originally described by Bietti, six additional patients with a similar clinical picture are observed and a familial basis could be proved in two patients and was suspected in one.
71 citations
TL;DR: The interpretation of these results is that when hemoglobin is bound to haptoglobin the stabilizing heme-heme interactions are suppressed with the result that the hemes of each type of chain (α and β) display their intrinsic oxidation-reduction properties.
46 citations
TL;DR: It has been shown that, under the experimental conditions described, the degradation of H2O2 requires the presence of a free metal, and only in these conditions may it excite the chemiluminescence of luminol.
44 citations
TL;DR: The kinetics of the reactions of human hemoglobin with carbon monoxide and oxygen has been studied in photochemical and rapid mixing experiments over a large range of hemoglobin concentration and the properties of the single chain molecules obtained by dilution are the same as those of isolated α and β hemoglobin chains as obtained by preparative procedures.
39 citations
TL;DR: The anatomic base of colonic motility is defined more clearly and a succession of contractions and decontractions having a craniocaudal direction and re la ted to large displacements of the contents, especially semisolid contents is defined.
Abstract: T HE ANALYSIS O[ gastrointestinal motil i ty can be quali tat ive or quantitative. Qual i ta t ive analysis concerns identification of the movements of the wall and d~eir f imctional significance. Quant i ta t ive analysis consists o[ measuring mechanica l activity over a long period. F r o m a quali tat ive point of view, the motor activity of the h u ma n colon t may be classified both as \"local\" and as \"nonlocal .\" Th is dist inction is advantageous since it is based on terms common to both of the procedures we are cur ren t ly employing (i.e., in t ra luminal pressure records and synchronized c inef luorography) . Loca l activity is characterized by nontransposi t ion of the mechanical events and it consists mostly of segmentation. Nonlocal activity, on the other hand, is represented by a point-to-point transposition of events, and it corresponds essentially to movements which we may call peristaltic: that is, a succession of contractions and decontractions having a craniocaudal direction and re la ted to large displacements o[ the contents, especially semisolid contents (Fig. DW e have done some work in order to define more clearly the anatomic base of colonic motility. M E T H O D AND R E S U L T S
33 citations
TL;DR: The data suggest that the thermal transition is predominantly a two-state process involving two widely different macroscopic forms, associated with large changes in spectral properties, in optical rotatory dispersion and in fluorescence.
32 citations
TL;DR: The mathematical approach to diagnosis was examined in a group of 1,184 patients with congenital heart disease using a rather limited number of symptoms using a Fortran program which works out the a priori probabilities of 94 different malformations and the conditional probabilities of the 46 symptoms in the patient studied according to Bayes' formula.
TL;DR: In this paper, a new diterpene, incensole-oxide (I), was isolated from frankincense in small amounts, and the chemical and physico-chemical data showing the position of the oxirane ring, support the structure I.
TL;DR: A cyclic polypeptide containing ten amino-acid residues arranged in two identical groups has attracted considerable interest as a model related to the more complex globular proteins.
Abstract: GRAMICIDINE S is a cyclic polypeptide containing ten amino-acid residues arranged in two identical groups. This molecule has attracted considerable interest as a model related to the more complex globular proteins.
TL;DR: In this paper, the anation of the complex ion RH(NH3)5OH2]3+ has been studied at 65°C, in water solutions of controlled ionic strength.
TL;DR: In this article, the authors investigated the properties of extrusive and pyroclastic rocks of Alban Hills, Vico and Cimino Volcanoes as well as of their minerals such as leucite, sanidine, biotite and zeolites.
TL;DR: This paper will present data on another such family with a probable 21/21 translocation in mongolism (Down’s syndrome) that can be considered likely if a known translocation carrier has only mongo1 children and the number of offspring is large enough to make the absence of normal or carrier children significant.
Abstract: The first report of a G/G translocation$ in mongolism (Down’s syndrome) was that of Fraccaro, Kaijser & Linsten in 1960. Since that time many other cases have been reported. The most recent reviews on this subject are by Turpin & Lejeune (1965) and by Penrose & Smith (1 966). Discrimination between chromosomes number 21 and 22 is still difficult, and frequently inadequate on the basis of either morphological or replication studies. Consequently, a 21/21 translocation cannot be identified with certainty, but can be considered likely if a known translocation carrier has only mongo1 children and the number of offspring is large enough to make the absence of normal or carrier children significant. Dallaire & Fraser (1964) observed a family with a probable 21/21 translocation. This paper will present data on another such family.
TL;DR: This work decided to study the carbohydrate content of cytoplasmic AAT to see whether this might provide evidence for structural differences between the various subforms.
TL;DR: The authors are in favor of cytogenetic analysis in the study and diagnosis of such neoplastic lesions, especially those undergoing initial carcinomatous transformation and those thought to be in a stage of transition to malignancy.
Abstract: The authors have carried out direct chromosome analysis on cells obtained from benign and malignant epithelial solid tumors of the gastrointestinal tract and especially on adenomatous polyps in relation to their carcinomatous evolution. A normal diploid karyotype was found in the earliest adenomatous polyps. In adenomatous polyps undergoing carcinomatous transformation, at both early and advanced stages and in the primitive carcinomatous forms, extensive alterations of the karyotype linked with cellular malignancy have been found. These karyotype alterations, represented by morphologic and numerical alterations, are extremely irregular and not strictly related to the site and the degree of diffusion of neoplasia. The authors are in favor of cytogenetic analysis in the study and diagnosis of such neoplastic lesions, especially those undergoing initial carcinomatous transformation and those thought to be in a stage of transition to malignancy.
TL;DR: The results show that the oxygen Bohr effect, although smaller, is similar in shape to that of mammalian hemoglobins and can be fitted by the same model.
TL;DR: Succinyl and phthalyl esters of native and clinical dextrans may bind Cu ++ and Fe ++ ions, at neutral Ph, giving rise to undialyzable chelates, and some information about the metal-polysaccharide bonding have been obtained by EPR analysis.
TL;DR: Talk ligature is at present the ideal method for intracranial saccular aneurysm because it reduces the risk of recurrent bleeding without eliminating the circulation through the anterior communicating artery.
Abstract: Publisher Summary The purpose of this report is to present results obtained by the Division of Neurological Surgery at the University of Rome with surgical treatment of aneurysms involving the anterior communicating artery. The investigation includes 45 consecutive patients operated upon prior to December 1965. The patients in this series were admitted after intervals varying from hours to weeks following an initial hemorrhage or following a recurrent hemorrhage. The primary object in the treatment of patients with ruptured aneurysms is the prevention of recurrent bleeding and the evacuation of a large hematoma if present. The selection of the best timing for the operation depends on the surgeon's estimate of the relative hazards of early intervention versus the risk of further bleeding. In determining the timing for surgery one considers the condition of the patient more important than the interval from the last hemorrhage. Talk ligature is at present the ideal method for intracranial saccular aneurysm because it reduces the risk of recurrent bleeding without eliminating the circulation through the anterior communicating artery. Ligature of the communicating anterior artery on both sides of the neck of the aneurysm, when this appears feasible, can be done safely if there are no abnormalities of the circle of Willis. Also a partial occlusion of one of the anterior cerebral arteries can be done without damage if the blood pressure is normal. In cases of trapping, the use of hypothermia during and in the postoperative period is advisable.
TL;DR: In this paper, the electronic spectra for both the CrL 3 X 3 species and the solvolysis products are discussed and discussed for both of them, and the spectrochemical strength of thioureas appears to be particularly low, in comparison with data on Thiourea complexes of other transition metals.
TL;DR: This work has shown that the affinity of haemoglobin for oxygen varies according to the conditions in which the measurements are made, and this should not be confused with prior work on affinity ofoglobin for carbon dioxide.
Abstract: IT is well known that the affinity of haemoglobin for oxygen varies according to the conditions in which the measurements are made1.
TL;DR: Les Auteurs, a suite d'une serie des recherches on la coloration au bleu Alcian de la cartilage, on pu demontrer que la signaleticite de ce colorant basique envers les mucopolysaccharides est due a la interference inhibitive avec une fraction proteique presente en grande quantite dans les structures non-mucopoly-saccharidiques ionisees au pH de utilisation (2,4) (DNA, collagene etc.).
Abstract: Les Auteurs, a la suite d'une serie des recherches sur la coloration au bleu Alcian de la cartilage, on pu demontrer que la signaleticite de ce colorant basique envers les mucopolysaccharides est due a la interference inhibitive avec une fraction proteique presente en grande quantite dans les structures non-mucopolysaccharidiques ionisees au pH de utilisation (2,4) (DNA, collagene etc.), fraction bien soluble dans les solutions salines et dans l'acide sulphurique 1 M, mais peu soluble dans l'acide acetique 3%.
01 Jan 1968
TL;DR: Compared the ultrastructural changes induced by LATS and TSH in the thyroid of mice having their endogenous TSH secretion suppressed by the administration of thyroxine to suggest that TSH and LATS act on the thyroid gland through the same mechanism.
Abstract: The biochemical structure and the immunological properties of the long-acting thyroid stimulator (LATS) and thyrotropin (TSH) are different (1), but their effects on the thyroidal iodine metabolism are similar, differing only in their time course (2, 3). Histologic studies have so far failed to show any major qualitative difference between the TSH and LATS stimulated thyroid glands. Both substances appear to affect in a similar manner the height of the thyroid follicular cells, the staining properties of the colloid (4) and the formation of intracellular colloid droplets (5). The similarities described above may suggest that TSH and LATS act on the thyroid gland through the same mechanism (6). In order to elucidate this problem, we have compared the ultrastructural changes induced by LATS and TSH in the thyroid of mice having their endogenous TSH secretion suppressed by the administration of thyroxine.
TL;DR: The haemoglobin picture has been studied in 38 patients with Cooley's anaemia, all homozygous for β‐microcythaemia, where Hb A1 was completely absent and in the remaindcr it was present on agar gel electrophoresis in amounts varying from minute traces to a rather abundant quota.
Abstract: Summary The haemoglobin picture has been studied in 38 patients with Cooley's anaemia, all homozygous for β-microcythaemia. In 10 of the patients Hb A1 was completely absent, in the remaindcr it was present on agar gel electrophoresis in amounts varying from minute traces to a rather abundant quota.
In 34 of the Cooley's patients studied Hb A2 was present in amounts comparable to those found in normal non-microcythaemic subjects. In the rest it was raised as in heterozygous carriers of β-microcythaemia. There was no correlation between the haemoglobin picture and the severity of clinical findings.
The genetic significance of the different types of haemoglobin picture found in Cooley's patients is discussed.
01 Jan 1968
TL;DR: Details of X-ray crystallographic studies of the two equilibrium forms of myoglobin from the sperm whale, which are involved in this oxygenation-deoxygenation reaction, are presented.
Abstract: The proteins myoglobin and haemoglobin have as their chief physiological function the reversible combination with molecular oxygen. In this contribution we present details of X-ray crystallographic studies of the two equilibrium forms of myoglobin from the sperm whale, which are involved in this oxygenation-deoxygenation reaction.