Showing papers by "University of Perugia published in 1983"

Phagocytic killing of Candida albicans by different murine effector cells

Abstract: Three major phagocytic populations in the mouse were tested in vitro for killing of Candida albicans by means of 51Cr release assay: early inflammatory peritoneal polymorphonuclear cells (PMN), unfractionated or adherent spleen cells and resident peritoneal macrophages (PEC). Considerable candidacidal activity was found in the early inflammatory neutrophil and adherent spleen cell populations. On the contrary, only limited activity was found to be associated with resident peritoneal macrophages. The phagocytic killing apparently involved multiple mechanisms.

Thrombolytic Therapy for Thromboembolism of Vertebrobasilar Artery

Abstract: Thrombolytic therapy was carried out on four patients with brain stem stroke due to thromboembolism of the vertebrobasilar system. Diagnosis was confirmed by angiography. Clinical and instrumental findings indicated a very poor prognosis. Two of these patients were treated with urokinase and the other two with streptokinase for periods ranging from 16 to 44 hours. The interval between onset of symptoms and start of therapy was less than 10 hours for three of these patients. All made a gradual and almost complete recovery after only a few hours of treatment, and only one presented minimal residual neurological disability. The conditionof the fourth patient, who started therapy four days after the first episode, remained unchanged until he died 16 hours later.Our observations suggest that thrombolytic therapy may be useful in treat ing recent acute life-threatening brain stem stroke.

Radiofrequency destruction of the tuberoinfundibular region of hypothalamus permanently abrogates NK cell activity in mice

Abstract: Natural killer (NK) cells have an important role in non-adaptative resistance to tumours and their metastatic spread in vivo. Maturation of NK cells and the intensity of their activity are affected by many endogenous and external factors, as well as by regulatory cells. The possibility that some effects of the central nervous system on tumour resistance are mediated via NK activity has also been suggested. Destruction of the tuberoinfundibular region of the hypothalamus in rodents led to a significant increase in tumour growth. We show here that destruction of its ventromedial, dorsomedial and arcuate nuclei persistently abrogates NK activity in mice. By contrast, cortical lesion and operative stress depress it partially, and for a brief period only. Abrogation is the result of a block of NK lineage maturation, causing a severe decrease in the number of large granular lymphocytes (LGL), a lymphocyte population associated with NK activity. Macrophage, B- and T- lymphocyte functions, however, are not significantly affected. Agents inducing NK-cell maturation or activation such as polyinosinic-polycytidylic acid (poly(I:C], interferon (IFN) and interleukin-2 (IL-2) restore NK activity, and normalize the number of LGL.

Vibrational spectra and assignments of ethylene‐diamine and its deuterated derivatives

Abstract: The infrared and Raman spectra of ethylenediamine and its deuterated derivatives have been studied in both the liquid and solid states. An assignment of the fundamental vibrational modes for the four molecules is proposed assuming for the liquids a gauche configuration (C2 symmetry); the assignment is based on depolarization values, isotopic shifts and classic group frequencies correlations.

Correlation between in vivo and in vitro studies of modulation of resistance to experimental Candida albicans infection by cyclophosphamide in mice.

Abstract: Mice receiving a single injection of cyclophosphamide (150 mg/kg) 1 to 6 days before inoculation with viable Candida albicans showed an increased susceptibility to the challenge accompanied by a reduction in peripheral blood polymorphonuclear leukocytes and lymphocytes as well as in spleen cellularity. Several immunological in vitro functions also appeared to be dramatically depressed. Most of these hematological and functional parameters returned to control values by day 9 after cyclophosphamide administration, at a time when resistance to C. albicans infection appeared to be unchanged. However, when exposure to cyclophosphamide occurred 12 to 21 days before inoculation with the live yeast, enhanced resistance was observed with the majority of the animals surviving challenge. To gain some insight into the mechanisms underlying this late increase in resistance to C. albicans infection after cyclophosphamide administration, we analyzed a series of immunological functions, including the in vitro candidacidal activity of polymorphonuclear neutrophils and plastic-adherent and nonadherent spleen cells as well as the activity of natural killer cells and alloreactive T lymphocytes. The results show that a numerical rebound of blood polymorphonuclear neutrophils and the appearance of a highly candidacidal cell population in the spleen may be among the factors underlying the late increase in resistance to C. albicans after administration of cyclophosphamide.

The afferent and preganglionic parasympathetic innervation of the rat liver, demonstrated by the retrograde transport of horseradish peroxidase.

Abstract: The afferent and parasympathetic preganglionic innervations of the rat liver were investigated by the use of retrograde transport of horseradish peroxidase (HRP). Vagal nerve fibers reach the rat liver by way of the left and right hepatic nerves, which originate from the homonimous abdominal vagal trunks. Three different experimental protocols were used: (i) intraparenchymal HRP injections; (ii) retrograde HRP injection through the common bile duct; (iii) HRP application to the central end of the severed hepatic nerves. The technical problems inherent in these 3 methods were experimentally investigated, with regard to the possible leakage of HRP from the liver after retrograde injection. It is concluded that leakage of HRP occurs, but it is not sufficient to cause non-specific labeling. Neurons of the lower thoracic dorsal root ganglia (DRG) are bilaterally labeled following intraparenchymal and retrograde HRP injections. Bilateral labeling of the nodose ganglia (NGs) following retrograde injection is still observed after subdiaphragmatic section of the left abdominal vagus, whereas cervical transection prevents labeling of the ipsilateral NG. Labeling produced by exposure of the left hepatic nerve to HRP is prevented by subdiaphragmatic transection of the left abdominal vagus. Efferent neurons located bilaterally in the dorsal motor nucleus (DMN) and in the left nucleus ambiguus (NA) are labeled following retrograde HRP injection. Only ipsilateral labeling is observed after HRP application to the cut left hepatic nerve. HRP exposure of the left abdominal vagus yields bilateral labeling in both DMN and NA. It is concluded that: (i) the afferent innervation of the rat liver is provided by the lower thoracic DRG and by the NGs of both vagi, mostly by the left; partial crossing of vagal afferent fibers takes place at thoracic level; and (ii) the liver receives efferent fibers bilaterally from the DMN and from the left NA; the DMN neurons project to the liver via the homolateral hepatic nerves, and those of the NA via the left hepatic nerve.

The adrenergic contribution to glucose counterregulation in type I diabetes mellitus. Dependency on A-cell function and mediation through beta 2-adrenergic receptors.

Abstract: In order to assess the adrenergic contribution to hypoglycemie glucose counterregulation in type | diabetes mellitus and to determine whether the adrenergic contribution is mediated through beta1- or beta2-adrenergic receptors, hypoglycemia was induced by an i.v. insulin infusion (30 mU/m2 · min) for 60 min in 11 insulin-dependent diabetic patients (IDDM), 5 with normal plasma glucagon responses and 6 with blunted responses, and also in 7 age-weight-matched nondiabetic subjects. Rates of plasma glucose decrease and postnadir increase, as well as plasma concentrations of free insulin and of counterregulatory hormones, were measured when insulin was infused alone, and when insulin was infused along with propranolol (a beta1- and beta2-adrenergic receptor antagonist) or metoprolol (a selective beta1-antagonist). Postnadir plasma glucose recovery was decreased in IDDM with blunted plasma glucagon responses (21 ± 0.8 µmol. L−1 min−1, P < 0.001), but was normal in patients with normal plasma glucagon responses (30 ± 0.4 versus 33 ± 0.5 μmol · L−1 · min−1 in nondiabetic subjects, P = NS). Postnadir plasma glucose recovery was not affected by either propranolol or metoprolol in normal subjects and in IDDM with normal glucagon responses. However, in IDDM with blunted plasma glucagon responses, postnadir plasma glucose recovery was further decreased by propranolol (14 ± 0.6 µmol. L−1 min1, P < 0.01), but was unaffected by metoprolol (22 ± 0.9 μmol. L 1 min1, P = NS). These results demonstrate that, as in normal man, adrenergic mechanisms are not essential for normal plasma glucose recovery from hypoglycemia in IDDM with normal plasma glucagon responses. However, in IDDM with blunted plasma glucagon responses, adrenergic mechanisms become important for glucose counterregulation although they do not fully compensate for the blunted plasma glucagon responses. Since propranolol delayed plasma glucose recovery from hypoglycemia in IDDM with blunted glucagon responses but metoprolol had no effect, the adrenergic contribution to glucose counterregulation appears to be mediated through beta2-adrenergic receptors.

Measurement of production and properties of jets at the CERN\(\bar pp\) collider

Abstract: The production and properties of high transverse momentum hadron jets have been measured in the UA2 experiment at the CERN $$\bar pp$$ Collider $$(\sqrt s = 540 GEV)$$ using a highly segmented total absorption calorimeter. The characteristics of a sample of two-jet events with invariant mass up to 200 GeV/c2 are discussed, including measurements of their fragmentation properties, angular and rapidity distributions, and the properties of the additional energy clusters accompanying the two-jet system. Cross sections for inclusive jet production in the jet transverse momentum range between 30 and 100 GeV/c and for the two-jet invariant mass distribution in the mass range from 60–200 GeV/c2 are reported.

Improved Method for Isolation of Bacterial Inhibitors from Oleuropein Hydrolysis

Abstract: A new high-pressure liquid chromatography multidetection quantitative method for the isolation of the products of oleuropein hydrolysis is described. A single analysis yields sufficient amounts of the compounds to test their inhibitory effect on bacterial growth.

Metabolism of Phosphoglycerides

Abstract: Glycerophospholipids are present in all living organisms and are necessary for membrane assembly and function. Their presence in nervous tissue has been recognized for many years,1 and, with the development of suitable analytical techniques, their metabolism has been amply studied and is being investigated in different aspects in several laboratories.

Morphological and functional characteristics of human temporal-bone cell cultures

Abstract: Morphology and calcium metabolism have been studied on five different cell cultures from human normal adult temporal-bone biopsies obtained during five stapedectomies. Control cell cultures were obtained from normal human skin. Four different cell types were observed in the bone biopsies: 1) osteoblast-like cells; 2) osteoclast-like cells; 3) fibroblast-like cells; 4) intermediate cells. However, morphology by itself is inadequate for clear differentiation of the four cell types. Hormonal stimulation with calcitonin and dibutyryl-cAMP in presence of 45Ca++ showed a clear-cut difference in 45Ca++ uptake between cultured cells deriving from bone and skin. Functional responses to hormonal stimulation are therefore more specific than cell shape and morphology in differentiating fibroblasts from bone cells. Since responses to hormonal stimulation confirm that temporal-bone cell cultures actually contain bone cells, such cultures seem to be a good experimental model for the study of bone morphology and physiology.

Induction of lung tumors and lymphomas in BALB/c mice by metronidazole.

Abstract: Metronidazole, which is widely used in the treatment of "Trichomonas vaginalis", "Entamoeba histolytica" and "Giardia lamblia" infections, was administered to BALB/c mice by stomach tube in an aqueous solution at a dose rate of 2 mg/day for 100 days (total 200 mg) to test its carcinogenicity The treatment induced a significant increase in lung tumors in male mice (p less than 0001) and provoked the appearance of lymphomas in females (p less than 0001) Although there is insufficient evidence to pass judgement on the potential carcinogenicity of metronidazole in man, the results of this and other investigations reported in the literature have demonstrated that metronidazole develops carcinogenic activity in rats and mice

Identification of Drugs by Principal Components Analysis of Rf Data Obtained by TLC in Different Eluent Systems

Abstract: The retention factor of 54 drugs In eight eluent mixtures is reported. Principal component analysis (PCA) of these data provided a significant two-components model. These two parameters characteristic for each drug allowed an objective identification of unknown samples, provided they were included in the considered set. The analysis showed that the eluent mixtures cluster Into three groups. The PCA model, using only three eluents (one for each group), was also able to restrict the range of Inquiry to a few "candidates" and, In some cases, to allow unambiguous identiflcation of the drug. These results, based on a simple and quick analytical deterruination (thin layer chromatography) and a reliable statistical procedure (PCA), appear to be of significant practical importance in the field of analytical toxicology.

Study of triglyceride- protein interaction using a microemulsion- filtration method

Abstract: Interactions between simple triglycerides and a variety of native and chemically modified proteins were studied. A new procedure was developed to evaluate hydrophobic binding of proteins at oil/water interfaces. The method involves emulsifying a triglyceride ultra-sonically in water and equilibrating the microemulsion with a protein solution. The protein adsorbs to the surfaces of the globules as a stabilizing interfacial layer. Relative stability of different emul-sions is evaluated under standard conditions of partition with a poly-carbonate membrane filter. Either gas liquid chromatography or a radioactive technique is used to determine the amount of trigly-ceride stabilized by protein through hydrophobic binding. The procedure was used to compare interactions of six different trigly-cerides with bovine serum albumin (BSA) and interactions between trioctanoin and 26 different native and chemically modified pro-teins. In general, an increase in molecular weight of saturated trigly-cerides or an increase in double bonds of unsaturated triglycerides reduced hydrophobic binding. The order of binding of trioctanoin for the series of proteins (on a weight basis) compared to BSA taken as 100%, ranged from 160% for casein to 1% for lysozyme. Addition of nonpolar residues, including methyl, cyclohexyl, cyclopentyl and benzyl groups, to casein increased binding by 20–30%. Effects of protein mixtures, and changes in pH and ionic strength also were studied. The results demonstrate that interactions between a wide variety of triglycerides and proteins can be investigated by the microemulsion-filtration method.

Drug-Induced Immunogenic Changes of Murine Leukemia Cells: Dissociation of Onset of Resistance and Emergence of Novel Immunogenicity

Abstract: n vivo exposure of tumor-bearing mice to the antineoplastic agent 5-(3,3-dimethyl-1-triazenyl)-1H-imidazole-4-carboxamide (DTIC) results in increased immunogenicity of tumor cells, an event often referred to as "chemical xenogenization" (CX). To verify the hypothesis of DTIC-induced somatic mutation(s) as the major mechanism underlying CX, studies were performed to dissociate CX from the onset of drug resistance, which was invoked in the past as an event leading to selection of preexisting immunogenic clones. Therefore, experiments were done with a DTIC-susceptible tumor line treated with DTIC and quinacrine dihydrochloride (Q), an antimutagenic compound, according to selected experimental schedules. At different transplant generations, the CX and the onset of drug resistance were evaluated. The results show that a) Q does not prevent the onset of DTIC resistance, b) DTIC-resistant clones arising after treatment with DTIC plus Q are not immunogenic, and c) CX is selectively antagonized by Q. The present data confirm that DTIC-induced immunogenicity is not the result of a selection mechanism mediated by the drug and give further support to the hypothesis that the molecular mechanism of CX may be related to somatic mutation(s).

A Graphic Characterization of Hermitian Curves

Abstract: Publisher Summary This chapter presents a graphic characterization of hermitian curves. In PG(2,q), q square, a set ∪ of points is called a Hermitian arc (or a unital) if it is a (q + 1, + 1). In particular, ∪ is called a Hermitian curve if there is a Hermitian polarity for which ∪ is the set of self-conjugate points. It had been conjectured that a Hermitian arc is always a Hermitian curve.

Accurate Ne-heavier rare gas interatomic potentials

Abstract: Accurate interatomic potential curves for Ne-heavier rare gas systems are obtained by a multiproperty analysis. The curves are given via a parametric function which consists of a modified Dunham expansion connected at long range with the van der Waals expansion. The experimental properties considered in the analysis are the differential scattering cross sections at two different collision energies, the integral cross sections in the glory energy range and the second virial coefficients. The transport properties are considered indirectly by using the potential energy values recently obtained by inversion of the transport coefficients.

A study of cytopathic rotavirus strains isolated from calves with acute enteritis

Abstract: Nine cytopathic bovine rotavirus strains were isolated in MA-104 cell cultures from fecal specimens of dairy calves suffering from diarrhea. Isolation of the virus was accomplished from three outbreaks which occurred on dairy farms located in Central and Southern Italy. Fecal suspensions were treated with a high concentration (1000 micrograms/ml) of trypsin, and inoculated into MA-104 cell cultures grown out in Eagle's minimum essential medium (MEM) containing 5 micrograms/ml of the enzyme. Cytopathic effects (CPE), characterized by intracytoplasmic inclusion bodies of different sizes and shapes, were observed on the 1st passage with five of the strains and on the 2nd (2 strains) or the 3rd (2 strains) passage for the others. The presence of trypsin and the use of MA-104 cells appeared to be essential for the occurrence of CPE, inasmuch as no CPE was detected when trypsin was omitted in the MA-104 cell system. Replication failed to occur when primary bovine embryo kidney cell cultures with or without trypsin were used. Electron microscopy revealed the presence of particles with a typical rotavirus morphology. In MA-104 cells, the titre of virus reached its maximum 48 hr after inoculation. Small, clear-cut plaques were produced by the isolates in MA-104 cells under the overlay of MEM containing carboxymethyl cellulose, trypsin and DEAE-dextran. The nine rotavirus strains were antigenically related, whereas the relationship to either the Nebraska or the Compton rotaviruses was quite weak.

Clinical heterogeneity in Sanfilippo disease (mucopolysaccharidosis III) type D: presentation of two new cases

Abstract: Clinical, radiological and biochemical findings of two new cases of Sanfilippo disease, type D are reported. A high percentage of heparan sulfate was found in the urinary glycosaminoglycan pattern and a severe deficiency of N-acetylglucosamine-6-sulfate sulfatase was demonstrated in skin cultured fibroblasts from the patients. One of the patients presented mild intellectual impairment which differentiates him from the other cases described to date.

Interaction of adenosine 5'-triphosphate with metal ions X-ray structure of ternary complexes containing Mg(II), Ca(II), Mn(II), Co(II), ATP and 2,2'-dipyridylamine.

Abstract: The X-ray structures of the isomorphous Mg2+, Ca2+, Mn2+ and Co2+ complexes of ATP have been determined. The metal ions are wrapped in hexa-coordination by the α, β and γ phosphate groups of two ATP molecules thus blocking the interaction of the metal ions with the adenine base. A second metal ion which is fully hydrated, M(H2O)2+ 6, is engaged in a strong hydrogen bond with the γ phosphate group of ATP and suggests a possible step in facilitating the cleavage between the β and γ phosphates in phosphoryl transfer reactions.