Showing papers by "Sapienza University of Rome published in 1979"

Lysozyme film hydration events: an ir and gravimetric study.

Abstract: By a combined gravimetric and ir technique, spectra of protein films are recorded during sorption isotherms at constant water content h (mg D2O/mg dry protein) in the range 0 les; h ⩽ 0.35 at 27 and 38°C. Computer-aided differential analysis shows the effect of progressive hydration on some significant sites of the protein such as the ionizable acidic side chains and the backbone amide carbonyls, as well as the spectrum of the adsorbed water itself. In order to derive thermodynamic properties of these sites, the measured sorption isotherm is decomposed in terms of a model which postulates the existence of two classes of primary sorption sites only, and these two contributions are independently checked by the ir data. The free energy of binding of the strong and weak binding sites is found to be 2.0 ± 0.2 and 0.40 ± 0.1 kcal/mol, respectively. A water-induced transition region is clearly detected in all the observed properties at 0.06 < h < 0.10 at 38°C and is shown to be due to changes involving both the structure of the absorbed water and the coverage of the absorption sites. A detailed picture of the hydration events is offered, and the relevance of these findings to protein dynamics is discussed.

Radioimmunoassay measurement of prostaglandins E2 and F2alpha in human urine.

Abstract: Techniques are described in detail for the radioimmunological measurement of prostaglandin (PG) E2 and F2alpha in human urine. 50 ml urine samples are extracted with an organic solvent system and then purified by silicic acid column chromatography. The overall recovery after extraction and purification, calculated with labeled as well as unlabeled compounds, is in the order of 70%. The column eluates are assayed at 1:12-1:60 dilution in the "standard diluent" of the assay: 8 pg PGE2 or PGF2 alpha/ml of whole urine represents the lowest measurable concentration. A urine blank and a solvent blank were evaluated separately, subjecting 50 ml of urine obtained from an indomethacin treated subject ("PG-free" urine) or 50 ml of distilled water, respectively, to the extraction-purification procedures. Both were found not to interfere with the antigen-antibody reaction. Urinary PG-like immunoreactivity (LI) was characterized in terms of immunochemical and thin-layer chromatographic (TLC) behavior. Both urinary PGE2-LI and PGF2 alpha-LI behaved as authentic PGE2 and PGF2 alpha, upon dilution and on TLC. In 33 healthy female subjects (aged 19-58 yr), urinary excretion rates averaged 178 +/- 80 (mean +/- SD) ng/day for PGE2 and 498 +/- 181 ng/day for PGF2 alpha. In a group of 8 healthy men, both PGE2 and PGF2 alpha excretion rates were higher and more scattered than the female values. When two healthy women were given indomethacin (200 mg/day), urinary PGE2 and PGF2 alpha dropped to undetectable levels during the 4th day of drug therapy. Intravenous injection of furosemide (50 mg) in a female volunteer was followed by an immediate rise of urinary sodium, PGE2, PGF2 alpha and PGE2/PGF2 alpha ratio and plasma renin activity. In a 10 year old girl with Bartter's syndrome, urinary PG excretion rate was elevated with a 3 times higher than normal PGE2/PGF2 alpha ratio. Indomethacin therapy resulted in a prompt drop of PG excretion rate and of plasma renin activity. These results show that a combination of adequate purification steps and antisera with optimal characteristics provides a reliable method for measuring PGE2 and PGF2 alpha in urine, and therefore a valuable tool to further our knowledge of the physiology and physiopathology of the renal PG-system.

Mimicry in the burnet moth Zygaena ephialtes: population studies and evidence of a Batesian—Müllerian situation

Abstract: . 1. Population size as well as the absolute and relative frequencies of the phegea and filipendulae mimetic complexes have been estimated in an area of Central Italy selected because it is: (a) little affected by man, (b) representative of many others in the Central Appennines, and (c) containing an abundant population of Zygaena ephialtes. 2. This distasteful polymorphic species belongs, in Central Italy as in other Southern areas, to the phegea complex (Zygaena ephialtes, yellow ephialtoid form), while in Northern and Central Europe it belongs to the filipendulae complex (Z.ephialtes, red peucedanoid form). 3. In the Southern areas the phegea complex is much more abundant than the filipendulae one, which gives the yellow ephialtoid form of Z.ephialtes a strong mimetic advantage over the red peucedanoid. 4. In addition, Amata phegea greatly outnumbers the other distasteful members of its complex and emerges first. 5. Throughout its flight period Z.ephialtes, which emerges about 20 days later than A.phegea, never attains a frequency higher than 0.03 in this complex. It is suggested that in such a situation the protection that this species gains as a mimic would be very high regardless of its unpalatability. 6. These findings and others discussed in the present paper, such as the degree of unpalatability, the genetics of the mimetic form as well as the polymorphism for colour and pattern, are examined according to the hypothesis of divergent evolutionary strategies in Batesian and Mullerian mimicry. It is suggested that these are meaningful concepts but that individual mimics, of which Z.ephialtes is one, can fall between them.

Notes on consumption, investment and effective demand: a reply to Joan Robinson

Abstract: 1. There are two basic theses in the article on which Joan Robinson is commenting. The first is that Keynes's principle of effective demand (i.e. that aggregate demand will not spontaneously adjust to supply) ultimately rests on the refutation of the theory of interest as the equilibrator of saving and investment, and not on the assumed rigidity of money wages. It is accordingly argued that the subsequent rehabilitations of the orthodox long-run relation between saving and investment have been due to weak nesses of Keynes's criticism of that interest theory. The second thesis is that, since the theory in question is the necessary expression of the dominant explanation of distribution in terms of the demand and supply for 'factors of production', the critique of the con ception of capital underlying this explanation may provide better support than was provided by Keynes himself for establishing the principle of effective demand in long period analysis. Associated with this second thesis is the argument that the appropriate theoretical setting for developing effective demand is provided by the surplus approach to distribution found in the classical economists and Marx.

Immunologic and clinical investigation on a bovine thymic extract. Therapeutic applications in primary immunoedificiencies.

Abstract: Summary: Thirteen patients with primary immunodeficiencies (eight with T-cell deficiency, one with Wiskott-Aldrich (W-A) syndrome, two with common variable agammaglobulinemia (CVA), and two with severe combined immunodeficiency (SCID)) were treated with a calf thymus extract, called thymostimulin (TS). It has been shown that this extract causes in vitro differentiation of T-cell precursors in patients with T-cell defect. Five of eight patients with pure T-cell defect showed immunologic recovery and clinical remission lasting for several months after interruption of the therapy; one had only transient reconstitution, one had slight increase in T-cells (clinical conditions not yet estimated), and two patients soon died from severe infections after showing a slight increase of T-cells. Immune recovery was assessed by an increase of the absolute number of E-rosettes forming cells, of human T-lymphocyte antigen positive cells and of PHA responsiveness in the peripheral blood, and by a positive delayed hypersensitivity reaction to antigens. In five patients, there was also B-cell increase after TS treatment. Clinical remission consisted of disappearance of infections, weight gain, and in improvement in general conditions. No effect was observed in one patient with W-A syndrome, in two with CVA, and in two with SCID. Several hypotheses on the mechanisms involved in immune reconstitution are discussed. It seems likely that TS acts on prethymic cells or on the epithelial cells of hypoplastic thymuses. TS was not effective, either in vitro or in vivo, in patients with SCID probably because of a defect in stem cells. Speculation: Thymic hormone therapy can be valid only in same patients with T-cell defect, after in vitro assessment of T-cell differentiation. Further experiments will be necessary to establish if this therapy can be extended in other deficiencies of cell mediated immunity associated to infections, malignancies, autoimmune syndromes, and malnutrition.

Dermatomyositis-like syndrome due to toxoplasma.

Abstract: SUMMARY A woman had the typical clinical, cutaneous, and muscular picture of dermatomyositis but without some of the biochemical alterations of that disease. The positive serological investigations for toxoplasmosis, the presence in muscles of very numerous toxoplasms and their culture in mice, and the improvement after treatment with pyrimethamine and sulphamethoxypyridine demonstrated that the signs of dermatomyositis had been caused by infection with toxoplasmosis.

Resorption of uncalcified cartilage in the diaphysis of the chick embryo tibia.

Abstract: The resorption of the uncalcified cartilage matrix of the middle third of the diaphysis in the chick embryo tibia has been studied using histological, histochemical and electron microscopic techniques. The first stage in the resorption process affects the periosteal bone, which is breached by osteoclasts at one or several points. Capillary vessels and clear, apparently undifferentiated cells penetrate through the holes so formed and reach the cartilage. The loss of acid proteoglycans to a depth of 10–20 μm into the matrix is the first sign of cartilage resorption; it is followed by the digestion of collagen fibrils, the opening of cell lacunae, chondrocyte degeneration and fragmentation and, lastly, the complete dissolution of the cartilage. This process is mediated by cells which probably derive from perivascular elements. Most of these cells have an undifferentiated appearance, but they have macrophagic properties, as is shown by phagocytotic activity along their plasma membrane, by the presence of lysosome-like bodies in their cytoplasm, and by their intense acid phosphatase activity. Resorption by giant cells of chondroclastic type only occurs at a late stage.

Mutational studies with diquat and paraquat in vitro.

Abstract: Diquat and paraquat were assayed in the following tests. (1) Ames test in Salmonella typhimurium (strains TA1535, TA1537, TA1538, TA98 and TA100) with and without rat-liver microsomal fractions. (2) Resistance to 8-azaguanine in Salmonella typhimurium (strain hisG46, TA92 and TA1535. (3) Repair test in Salmonella typhimurium (strains TA1538 and TA1978). (4) Gene mutations in Aspergillus nidulans: 8-AG resistance and methionine suppression (meth A1 locus). (5) Lethal recessive damage in Aspergillus nidulans. (6) Unscheduled DNA synthesis (UDS) in human epithelial-like cells (EUE). Diquat and paraquat were positive in S. typhimurium (in the repair test and the 8-AG resistance system), in A. nidulans (for gene mutations and lethal recessive damage induction) and in EUE cells (UDS induction).

Three dimensional organization of mammalian adrenal cortex. A scanning electron microscopic study.

Abstract: The adrenal cortex of different mammals was studied by SEM in order to demonstrate its actual three-dimensional organization. In the rat, as well as in the cat and pig, the adrenal cortex appeared as a “tunnelled continuum” of polyhedral cells arranged in plate-like structures (laminae). This laminar arrangement was more evident in the inner fasciculate and reticular zones where the cortex revealed a striking similarity to liver tissue. The polyhedral cells of all cortical zones possessed regular facets populated by small pits, larger invaginations and numerous microvilli with the exception of very short and smooth areas probably corresponding to attachment zones and/or gap junctions. This cellular architecture produced a labyrinthic system of intercellular channels or lacunae in which the capillaries were suspended. The pericapillary areas of this labyrinth contained microvilli, amorphous material, a delicate net of fibrils and occasional cells. The intercellular compartment of this lacunar system was mainly bordered by numerous microvilli arising from endocrine cells. The luminal surface of the capillary wall showed not only irregularly protruding margins (interpretable as endothelial junctions) but also clearly overlapping and flattened endothelial extensions. In all the animals and areas of the adrenal cortex examined, the endothelial wall was provided with abundant clusters of small fenestrations (about 50 nm in diameter) generally arranged in sieve plates. Larger fenestrations were noted mainly in the fasciculate and reticular zones of the cat and pig and occasionally in the rat. A final point related to the nature and significance of sinusoidal fenestrations was the occurrence of irregularly shaped and intracapillary located cells mainly noted in the deeper zones of the fasciculate and reticular zones of the gland. These elements — possessing the surface characteristics of macrophages — were observed, with their irregular and slender evaginations, in close proximity to the large fenestrations in a manner reminiscent of Kupffer cells within the lumen of liver sinusoids.

Angiographic diagnosis of jugular venous system dilatation in children. A report of five cases.

Abstract: We report five children with a soft mass in the neck due to congenital jugular venous ectasia. Three had fusiform dilatation of the internal jugular vein, which in one case was associated with dilatation of the ipselateral external jugular vein. Two children had aneurysmal dilatation of the superficial cervical communicating vein. The first four cases required angiographic studies for final diagnosis. Venography via the femoral vein was most valuable for visualization of the dilated segments of internal jugular veins but failed to show the vascular mass communicating with the superficial vein of the neck. These were best visualized by direct injection of the contrast medium into the vessel. In the fifth case a correct diagnosis was obtained with xeroradiography alone.

Partial trisomy 16q resulting from maternal translocation

Abstract: A 3 1/2-year-old male with partial trisomy of the long arm of chromosome 16 resulting from a maternal balanced translocation is described. Karyotype: 46,XY,-22,der(22),t(16;22)(q21;p12)mat.

Molecular forms of cholinesterases in cerebrospinal fluid, blood plasma, and brain tissue of the beagle dog.

Abstract: In the present study we have investigated the activity of AChE and BuChE in the cisternal CSF of the Beagle dog and have outlined the characteristics of the molecular forms of both enzymes. The same enzymes were also investigated in samples from blood plasma and brain tissue. It is concluded that AChE in CSF originates from the spinal cord and brain tissues as a result of some secretory process. A combined origin from both blood plasma and brain tissue appears to be probable for the BuChE of the CSF.

'De novo' trisomy 16q11 to pter.

Abstract: A de novo 16q- trisomy was found in a patient with severe mental retardation and mild physical abnormalities. A preliminary delineation the clinical features characteristic of trisomy 16q- is proposed, based upon comparison of the two cases identified so far. The mild phenotypical effects of this chromosome imbalance suggest that the alleged lethality of partial chromosome 16 aneuploidies should be reconsidered.