Showing papers by "Sapienza University of Rome published in 1972"
TL;DR: In this article, the upper limit of autoregulation of cerebral blood flow is discussed for the pathogenesis of Hypertensive Encepholopathy, and the authors propose a method to find the root cause of the disease.
Abstract: (1972). The Upper Limit of Autoregulation of Cerebral Blood Flow — On the Pathogenesis of Hypertensive Encepholopathy. Scandinavian Journal of Clinical and Laboratory Investigation: Vol. 30, No. 2, pp. 113-116.
135 citations
TL;DR: Bombesin‐like peptides constitute a new group of active peptides possessing a peculiar spectrum of activity and may easily be distinguished from all other naturally occurring peptides by parallel assay.
Abstract: 1. Methanol extracts of the skin of Bombina bombina and Bombina variegata variegata, two European discoglossid frogs, contain an active tetradecapeptide, bombesin. Alytesin, a tetradecapeptide strictly related to bombesin is present in extracts of the skin of Alytes obstetricans, another European discoglossid frog. The American frog Rana pipiens, contains in its skin ranatensin, an endecapeptide related to bombesin and alytesin.
2. Passage of crude skin extracts of Bombina through a column of alumina yields eluates which may be considered free of other peptide contaminants and are suitable for the isolation of bombesin in a pure form.
3. Bombesin has a stimulant action on several preparations of intestinal, uterine and urinary tract smooth muscle. Sometimes the effect is easily repeatable and shows a fair proportionality to the dose, but at other times a prompt and intense tachyphylaxis is observed. Other smooth muscle preparations are poorly sensitive or insensitive to bombesin. The rat uterus, the kitten small intestine, the guinea-pig colon and the rat urinary bladder may be used for the quantitative bioassay of bombesin.
4. Bombesin-like peptides may easily be distinguished from all other naturally occurring peptides by parallel assay. They constitute a new group of active peptides possessing a peculiar spectrum of activity.
132 citations
TL;DR: It is suggested that epinephrine, glucagon and insulin may modulate the activity of plasma membrane Na+−K+)-ATPase, by an action probably mediated by cyclic AMP.
121 citations
TL;DR: Acid hydrolysis, digestion with trypsin and chymotrypsin, and group determination experiments demonstrated that alytesin and bombesin are tetradecapeptides differing only in the second and sixth residues from the NH2-terminus.
118 citations
TL;DR: The measurements, which have been extended over a wide range of conditions, suggest that in haemoglobin there are at least two classes of chloride binding sites and that the high affinity sites are oxygen linked and over the range 0.1 to 2.5 m -NaCl deoxyhaemoglobin binds more chloride ions than liganded haemobic derivatives.
99 citations
TL;DR: The shearing strength of single human osteons has been investigated using a microtesting machine equipped with a microwave micrometer and the results related to the degree of calcification and the orientation of collagen fiber bundles in successive lamellae of the osteons suggested that in the other types of osteon the compactness of bone is strengthened by the lamella having marked transversal spiral course of the fiber bundles.
Abstract: The shearing strength of single human osteons has been investigated using a microtesting machine equipped with a microwave micrometer. The results Were related to the degree of calcification and the orientation of collagen fiber bundles in successive lamellae of the osteons. The following conclusions were made: (1) Osteons having a marked longitudinal spiral course of fiber bundles in successive lamellae are least able to support shearing stress. This suggests that in the other types of osteon the compactness of bone is strengthened by the lamellae having marked transversal spiral course of the fiber bundles. (2)Ultimate shearing strength and modulus of elasticity of osteons increase as calcification proceeds. (3) The shearing strength of single osteons is markedly lower than the tensile and compressive strength for samples of the same type. (4) In osteons loaded along their axis the range of elastic deformation is barely more than 1% of the length of the sample. (5) With the technical procedure used in this investigation the shearing of osteons appears to be preferentially related to the lamellar structure. In osteons loaded excentrically the portions which have slipped out have a rather irregular shape and in many cases one or two fractures occur. (6) The resistance to shearing of the cementing substance at the boundaries of the osteon may be greater than the resistance of the osteon itself.
94 citations
TL;DR: Results indicate that upon moderate heat treatment there is a definite increase of the immunogencity of these cells, which may have some relevance as to the mechanism of the delayed tumor regression which is often clinically observed after hyperthermic perfusion.
Abstract: Immunization of Swiss mice with Ehrlich ascites cells which had been exposed in vitro to 42.C for 3 hours is more effective, so far as subsequent tumor transplantation is concerned, than immunization with radiation‐inactivated cells or with cells exposed to 42.5C for 6 hours. These results, which indicate that upon moderate heat treatment there is a definite increase of the immunogencity of these cells, may have some relevance as to the mechanism of the delayed tumor regression which is often clinically observed after hyperthermic perfusion.
90 citations
TL;DR: In this article, it was shown that the exciton spectra in Pb${\mathrm{I}}_{2}$ can only be described in terms of a single Wannier series with a large ground state anomaly.
Abstract: It is shown that the exciton spectra in Pb${\mathrm{I}}_{2}$ can only be described in terms of a single Wannier series with a large ground-state anomaly. This anomaly is explained by a repulsive central-cell correction due to the cationic character of the exciton.
73 citations
TL;DR: A minimum estimate of the number of alcohol molecules differentially bound by the native and denatured conformations, based on linkage treatment, is found to be nearly independent of the type of alcohol used.
60 citations
TL;DR: In this paper, the authors discuss evidence that these effects may be due to conformational changes in the protein molecule and propose that these changes may be caused by specific interaction with antibodies.
Abstract: Several cases of modifications of functional properties of proteins upon specific interaction with antibodies have been reported in the last few years. The purpose of this paper is to discuss evidence that these effects may be due to conformational changes in the protein molecule.
52 citations
TL;DR: It is suggested that one sulfhydryl and one tryptophan at the copper site contribute to the unique features of the copper chromophore, as already shown in azurin.
TL;DR: The intensity of the EPR signal of the copper is remarkably lower in the cobalt erythrocuprein than that expected on the basis of the chemically determined copper, indicating magnetic interaction between the two paramagnetic ions.
TL;DR: The lack of knowledge of the behavior of loads during voltage depressions caused by faults in HV grids has been emphasized on many occasions as mentioned in this paper, and field and laboratory tests were advocated for more realistic representation of loads in transient stability studies.
Abstract: The lack of knowledge of the behavior of loads during the voltage depressions caused by faults in HV grids has been emphasized on many occasions. Field and laboratory tests were advocated for more realistic representation of loads in transient stability studies.
TL;DR: The EPR signal observed just after mixing apo-polyphenoloxidase and cupric copper decreases with a biphasic time course, while regain of enzymatic activity follows first order kinetics.
TL;DR: A model is proposed in which the acid and alkaline conformers of the ligand-free protein have different ligandbinding properties and it is suggested that there is a pH-dependent transition in the CO adduct of Cm-cytochrome c and the pK of this transition is reported.
TL;DR: During carotid surgery, hyperventilation was used in order to attenuate cerebral ischemia effects duringCarotid clamping, and a counter-steal phenomenon affecting a whole cerebral hemisphere was demonstrated, suggesting the role that hyperventilating may play in the treatment of cerebral isChemia.
Abstract: Use of hyperventilation (HV) was recently suggested for the treatment of acute cerebrovascular insufficiency. There is indeed no general agreement on the effectiveness of hyperventilation even though clinical and experimental findings could support its value in clinical use.
During carotid surgery, hyperventilation was used in order to attenuate cerebral ischemia effects during carotid clamping, and a counter-steal phenomenon affecting a whole cerebral hemisphere was demonstrated.
This suggests the role that hyperventilation may play in the treatment of cerebral ischemia.
TL;DR: The supergene hypothesis for the genesis of Tolfa alunites was proposed by Fuchs and De Launay (1893) as discussed by the authors, who showed that the sulfate-sulfur was derived from the surficial oxidation of sulfides.
Abstract: Sulfur isotope abundance data for minerals of the historically important alunite deposits of the Tolfa district indicate (1) compositional similarity between sulfates and sulfides (mean δS34 values of +5.54 and +6.34 permil respectively), (2) negligible fractionation factors (0.995 to 1.004) for sulfate-sulfide mineral pairs, (3) two distinct sulfide isotopic populations characterized by pyrite (+8.34 permil) and marcasite (−1.05 permil) and with associated alunite displaying a covariant isotopic shift, and (4) possible contamination of the hydrothermal system by evaporite sulfate (+25.1 permil) because hypogene pyrite, galena, and cinnabar are enriched in S34 (+6.1 to +10.3 permil). We suggest that alunite, barite, and possibly marcasite are of supergene origin and that the sulfate-sulfur was derived from the surficial oxidation of sulfides. Our conclusion is compatible with the geologic evidence and confirms the supergene hypothesis for the genesis of Tolfa alunites proposed by Fuchs and De Launay (1893) and De Launay (1906; 1913).
TL;DR: An investigation of the binding of methyl ethyl-, isopropyl-, n-propyl- and tertiary-butyl-isocyanides with normal human haemoglobin, meso- and deutero-reconstituted haemoglobins, several modified forms of the protein and the artificial CN-met intermediates reports some conclusions.
TL;DR: A model of the Actinomycin structure is derived on the basis of theoretical calculations taking into account available IR, NMR and x‐ray experimental data and contains two intercycle hydrogen bonds.
Abstract: A model of the Actinomycin structure is derived on the basis of theoretical calculations taking into account available IR, NMR and x-ray experimental data. This model contains two intercycle hydrogen bonds and accounts for all the experimental evidence.
TL;DR: The electron-donor ability of ferrocene is suggested by a number of chemical properties, such as charge-transfer complex formatlon. as mentioned in this paper, which can be the cvclopentadlenyl rmg (Cp), a functional group attached to It.
TL;DR: In this article, the activity coefficients have been correlated vs. the composition and the temperature through the Redlich-Kister equations, and the results highly dependable for a correct prediction of the equilibrium under any other condition.
TL;DR: The number of focal spikes or sharp waves was studied in 5 epileptic children during movement of the limbs and during psychological tests.
Abstract: UMMARY
The number of focal spikes or sharp waves was studied in 5 epileptic children during movement of the limbs and during psychological tests. Another patient studied had frequent petit mal absences.
All the patients showed a clear diminution in paroxysmal activity during simple arithmetical calculations, and rebound, i.e. increase in the number of discharges, after the tests.
In the 5 children with focal spikes and sharp waves, both mental tests and passive and active movements of the limbs caused the abnormalities to diminish or disappear independent of the site of the EEG focus. The effect was more marked when the limbs were moved contralateral to the affected hemisphere. There was rebound with increase in the number of spikes and sharp waves after the movements as well as after the tests.
In the patient with petit mal attacks the number of cortical discharges diminished during mental tests but was not modified during movements of the limbs. Also in this patient there was rebound with an increase in spike-and-wave discharges after the test.
RESUME
On a etudie le nombre des pointes ou des pointes lentes focales chez 5 enfants epileptiques au cours de mouvements des membres et pendant des tests psychologiques. Un autre sujet etudie presentait de nombreuses absences petit mal.
Chez tous les patients, il y avait une nette diminution de l'activite paroxystique pendant des calculs arithmetiques simples et un “rebond” c'est a dire une augmentation des decharges apres les tests.
Chez les 5 enfants presentant des decharges de pointes et pointes lentes focales, les tests mentaux et les mouvements passifs ou actifs diminuaient ou faisaient disparaitre les decharges, independamment de la topographie du foyer EEG.
La diminution des decharges focales sur l'hemisphere etait plus marquee lors des mouvements des membres controlateraux. Il y avait un “rebond” apres la fin des mouvements et des tests. Chez le sujet avec absences typiques, le nombre des decharges diminuait pendant les tests mentaux, mais n‘etait pas modifie par les mouvements. Chez ce dernier egalement, il y avait un “rebond” avec augmentation des decharges de pointe-ondes apres les tests.
01 Jan 1972
TL;DR: It is suggested that the cloverleaf skull syndrome essentially depends upon a chondrodystrophic condition which involves the base of the skull and may be generalized, as in the present case, or limited to one skeletal area, as sometimes reported in the literature.
Abstract: A histological, histochemical and ultrastructural study of a case of the clover-leaf skull syndrome is presented. It involved pronounced trilobed deformation of the skull associated with synostosis of the lambdoidal and sagittal sutures, hydrocephalus, downward displacement of the ears, hypertelorism, exophthalmus, a sunken nasal root and antimongoloid slant of the eyes. Shortening and bending of the limbs, narrowing of the chest, and deformation of the feet completed the picture.
TL;DR: In this article, a new macrocyclic diterpene, Isoincensole-oxide (I), has been isolated from Frankincense in very small amount, which can be obtained synthetically from Incensole; chemical and physico chemical data support the structure 12-isopropyl-1,5,9-trimethyl-1.12-oxido-5,6-epoxy cyclotetradec-9en-2ol.
TL;DR: In this paper, extracts of Latrodectus mactans tredecimguttatus venom glands were fractionated by means of gel filtration and ion exchange chromatography, and three protein peaks toxic to mice were assayed in vitro on three different preparations known to be affected by whole venom.
TL;DR: The conclusion has been drawn that the Neandertal man Circeo I had a well-developed torus palatinus of nodular type with incipient transformation into the lobular type.
Abstract: A histologic, microradiographic and electron microscopic study has been carried out on the nature and structure of palatal irregularities found in the skull of the Neandertal human remain Circeo I.
The histologic investigation of one of the palatal overgrowths shows that this is made up of spongy bone. Most of the trabeculae are of lamellar type, some of the others consist of primary woven bone. Osteocyte lacunae are clearly visible in the trabeculae, but mottled, granular areas are present too. These contain no recognizable structures. Microradiography shows this bone has low x-ray density, probably due to decalcification during fossilization. Needle-shaped apatite crystals are visible under the electron microscope. They are like those found in recent bone, although their often irregular arrangement seems to suggest the presence of collapsed tissue. The collagen fibrils do not always show a periodic pattern. The mottled, granular areas are crossed by many thin tubules, which are probably “Borhkanale.”
The conclusion has been drawn that the Neandertal man Circeo I had a well-developed torus palatinus of nodular type with incipient transformation into the lobular type.
TL;DR: It is suggested that progression of uremia might not represent the main cause of decrease in the Ep response to hypoxia following nephrectomy, and a decrease in REF activity might be responsible for the decline.