Showing papers by "University of Turin published in 1971"

Adrenergic innervation of the alimentary canal.

Abstract: The adrenergic innervation of the subdiaphragmatic digestive tract of the rabbit, the rat and the guinea-pig, has been studied by means of the histochemical technique of Falck and Hillarp. Auerbach's and Meissner's plexuses are richly supplied by adrenergic fibres both in the ganglia and in the connecting tracts. The distribution of adrenergic fibres appears fairly uniform within the myenteric ganglia of the different subdivisions. No adrenergic intramural neurons are found except in Auerbach's plexus of the proximal colon of the guinea-pig where particularly tightly packed clusters of pericellular baskets are also found. Adrenergic fibres are present within the circular muscle layer of all regions, and in the taeniae of the caecum of the guinea-pig. In the cardiac and the anal sphincters there is an exceedingly dense innervation of longitudinal and circular muscle. The glands of the mucous coat in the different parts of the gut are richly supplied by adrenergic nerves. There is a dense innervation of intestinal arteries. It is suggested that postganglionic adrenergic axons have a direct action on the muscle and that they indirectly affect the muscle by an action on intramural ganglia.

Acetylcholine system and neural development.

Abstract: Publisher Summary This chapter presents a few experimental results that contribute to the knowledge of the acetylcholine (ACh) system during development and to the analysis of the peculiar roles played by ACh in the growth processes of nervous and neuromuscular systems of vertebrates. ACh system includes, beside ACh itself, those enzymes that are directly involved in both its synthesis and inactivation, namely, choline acetylase (ChAc), acetylcholinesterase (AChE), and cholinesterase (ChE). The expression ACh system has been adopted instead of cholinergic system because ACh is not necessarily involved in the cholinergic mode of transmission of nervous impulses at synapses, particularly during embryonic development. The chapter discusses the occurrence of two different phases of the ACh system; the earlier one may be considered as a primary, ubiquitous, and transient property of all differentiating neuroblasts, and the later one develops exclusively in potential cholinergic neurons, and its appearance is critically related, at least in its chronological aspects, to the development of synaptic connections among different neuronal populations. While the later developing ACh system is the basis of a defined physiological event, namely, the transmission of nervous impulses at cholinergic synapses, the earlier ACh system plays some hitherto unknown role. Attempts are being made to correlate the early ACh system with transneuronal influences that may occur during the earliest developmental phases, with specific synthetic events that represent the background of maturational growth of neuroblasts.

Solvent effects in radical copolymerization. I. Acrylamide

Abstract: Acrylamide has been free radical copolymerized with styrene and methyl methacrylate at 70°C in different solvents (dioxane, dioxane/ethanol mixture, ethanol). A strong influence of the solvent on the copolymer compositions has been observed; particularly copolymers richer in acrylamide have always been obtained in dioxane. These results indicate that the nature of the solvent (polarity, dielectric constant etc.) could affect the polarity and the reactivity of the acrylamide double bond as well as the stability of the growing radical. Other factors are also discussed. Acrylamid wurde mit Styrol und Methylmethacrylat in verschiedenen Losungsmitteln (Dioxan, Dioxan/Athanol und Athanol) bei 70°C radikalisch copolymerisiert. Das Losungsmittel hat einen starken Einflus auf die Zusammensetzung der Copolymeren. Bei der Copolymerisation in Dioxan wurden Copolymere mit hoherem Acrylamid-Gehalt gefunden. Es wird angenommen, das die Natur des Losungsmittels (Polaritat, Dielektrizitatskonstante usw.) die Polaritat und die Reaktionsfahigkeit der Acrylamid-Doppelbindung beeinflussen kann ebenso wie die Stabilitat des wachsenden Radikals. Andere mogliche Ursachen werden diskutiert.

Histochemical and ultrastructural studies on pancreatic A cells. Evidence for glucagon and non-glucagon components of the α granule

Abstract: Glucagon-storing cells were detected in the pancreatic islets of horse, guinea pig, rabbit, rat, dog and man by means of indirect immuno-histochemical procedures using fluorescein or peroxidase as markers of antiglucagon sera. By subsequently staining horse islets with selective staining techniques for A, B or D cells, it was directly ascertained that only A cells reacted to antiglucagon sera. A comparison of methods known to stain a granules with immuno-histochemical methods, as well asin vitro experiments on natural and synthetic glucagon, showed that the xanthydrol method, and perhaps also theo-phthalaldehyde method, should be regarded as specific histochemical tests for glucagon whereas the HCl-basic dye technique and phosphotungstic haematein should be considered as unspecific glucagon-staining methods,and Grimelius' silver as a method likely to be unrelated to glucagon. In ultrastructural investigations on the human pancreas, the core of the a granule heavily reacted to phosphotungstic acid and peroxidase-marked antiglucagon antibodies, while being unreactive to Grimelius' silver; conversely, the peripheral halo of theα granule heavily reacted to Grimelius' silver, while being poorly reactive or unreactive to phosphotungstic acid and anti-glucagon antibodies. Thus, both light and electron microscopy findings point to a structural and chemical hetereogeneity of theα granule.

Ultrastructural and immunofluorescent investigations on the secretin cell in the dog intestinal mucosa

Abstract: Besides 5-hydroxytryptamine-storing EC cells, four types of endocrine non-EC cells have been identified in the dog intestinal mucosa: the S and D cells, mainly concentrated in the upper tracts of the small intestine, the L cell, concentrated in the lower tracts, and the I cell showing intermediate patterns between S and L cells. In immunofluorescence tests epithelial endocrine-like cells reacting to antisecretin sera were found in the duodenal mucosa. Only the S cell seems to exactly reproduce the distribution of secretin activity in different portions of gastrointestinal mucosa.

Studies on the structure-bound sedimentability of some rat liver lysosome hydrolases

Abstract: 1. Lysosome-rich fractions from rat liver were subjected to several disruptive procedures: osmotic lysis or freezing and thawing in different media, shearing forces in a high-speed blender, treatment with Triton X-100. 2. The soluble and particulate phases were then separated by high-speed centrifugation and assayed for their content of acid phosphatase, β-galactosidase, β- N -acetylglucosaminidase, acid proteinase, acid ribonuclease, acid deoxyribonuclease and protein. 3. The degree of elution of these hydrolases appeared to depend on both the enzyme species and the treatment. The resulting patterns of solubilization were rather complex, so that a clear-cut discrimination between soluble and structure-bound enzymes could not always be traced. 4. Although only β-galactosidase was readily solubilizable after all treatments, acid proteinase could also be extensively eluted from the sedimentable material in the presence of EDTA and acid phosphatase was fully extracted by Triton X-100. On the other hand, considerable proportions of the other activities could not be solubilized by any of the procedures used. 5. In other experiments, the adsorbability of hydrolases on subcellular structures was investigated by measuring the partition between sedimentable particles and soluble fraction of solubilized enzymes added to ‘intact’ liver homogenates. 6. Large proportions of acid proteinase, ribonuclease and deoxyribonuclease, and almost all of β- N -acetylglucosaminidase, were found to be adsorbed on the particulate material.

Solvent effect in radical copolymerization. II. N.N‐dimethyl acrylamide

Abstract: The free radical copolymerization of N.N-dimethyl acrylamide with styrene or methyl methacrylate has been carried out at 70°C in solvents of different dielectricity constants. The present work does not show the strong solvent influence on copolymer compositions previously found for acrylamide copolymerizations. The influence of the presence of two alkyl groups on the amidic nitrogen is discussed. The calculated copolymerization parameters agree with the values obtained by other authors. N.N-Dimethylacrylsaureamid wurde mit Styrol oder Methylmethacrylat bei 70°C in Losungsmitteln mit verschiedener Dielektrizitatskonstante radikalisch copolymerisiert. Anders als beim Acrylsaureamid, wurde kein bemerkenswerter Einflus des Losungsmittels auf die Zusammensetzung der Copolymeren beobachtet; die Wirkung der beiden Alkylgruppen an Amid-Stickstoff wird berucksichtigt. Die berechneten Copolymerisationsparameter stimmen mit den von anderen Autoren gefundenen Werten uberein.

Differential Response of B and T Cells to ALS revealed by Electrophoretic Mobility Determinations

Abstract: SINCE their discovery anti-lymphocyte antisera (ALS) have been widely investigated in order to clarify their mode of action and to determine their usefulness in clinical practice. Briefly, it seems that the efficacy of a particular ALS depends on its mode of production and on the method adopted for testing its immunosuppressive effect. It also seems likely that many ALS have a harmful effect on a population of thymus-dependent (T) lymphocytes1. It is the intention of this paper to confirm this notion and to indicate that other lymphocytes (B cells) are likely to be less affected by ALS.

Depressed tolbutamide-induced insulin response in subjects treated with propranolol.

Abstract: The effect of propranolol on 1 g i.v. tolbutamide-induced insulin response was studied in 11 subjects. The drug depressed this response, the effect being more noticeable in the patients receiving 200 mg/ dayper os for three days. The corresponding blood glucose curves, however, were unaffected by propranolol. The finding suggest that the beta-receptors play a part in sulphonylurea-induced insulin secretion in man.

Red Cell Glycolysis in the Myo dystrophic Child

Abstract: . Assay of seven glycolytic enzymes, steady-state levels of glycolytic metabolites, oxidized and reduced glutathione, inorganic phosphate, adenine nucleotides, sodium and potassium, and various incubation experiments were performed on red cells isolated from children with Duchenne-Erb muscular dystrophy. The activity of hexokinase, aldolase, pyruvate kinase, and the levels of glucose-6-phosphate, ADP and intracellular inorganic phosphate were significantly increased. Long term incubation (15 h at 4° C) showed a phosphofructokinase activation; during shorter incubation (3 h at pH 7.6 and 38° C) similar behaviour of glycolytic metabolites, 2,3-diphosphoglycerate and adenine nucleotides was observed in both normal and dystrophic red cells, while the lactate output was greater in the latter. The regulation of phosphoglycerate kinase and pyruvate kinase in vivo followed a normal pattern. Addition of ouabain to red cells incubated in a low-potassium buffer was followed by increase of ATP in the normal and a decrease in the dystrophic red cell. Ouabain had no effect on glycolytic metabolites in the dystrophic cell, whereas sharp increases of fructose-1,6-diphosphate and dihydroxyacetone-phosphate were observed in the normal cell.

Cross-Linking of Wool Keratin By Bifunctional Aldehydes:

Abstract: Treatment of wool fabrics with mono- and bifunctional aldehydes was followed by determinations of amino acid composition, NH2-group content, solubility in alkali, acids, and urea-bisulfite, affinity toward acid dye, and physico-mechanical properties. Differences were observed in the properties of treated and untreated fabrics. These differences are related to cross-linking between polypeptide chains of keratin.

Differentiation of ectopic retinal structures in the hypothalamo-hypophysial area in the adult crested newt bearing a permanent hypothalamic lesion.

Abstract: Ectopic differentiation of retinal structures in contact with the pituitary, after insertion of a methylene blue stained celloidin lamina at the level of the median eminence was observed in the adult crested newt (Triturus cristatus carnifex Laur.). Retinal components ranging from pigmented cells to early retinal vesicles and fully developed neural retina and visual cells are described. Indications pointing to the ependymal cells which line the infundibular sac sequestered between the intermediate lobe and the pars distalis, as the source of the neural retina and visual cells are presented.

Effect of methotrexate on DNA synthesis and thymidine kinase activity of human lymphocytes stimulated with phytohaemagglutinin.

Abstract: Il methotrexate provoca nei linfociti umani stimolati per 48 con fitoemagglutinina un aumento di incorporazione di timidina3H nell'ADN senza modificare sensibilmente il numero di cellule in fase S. La sintesi di ADN valutata con l'incorporazione di32P risulta diminuita, mentre l'attivita della timidin kinasi non e modificata dal trattamento con MTX.

Acetylenic derivatives of metal carbonyls of the triad Fe, Ru, Os—XI Mass spectra of some binuclear complexes

Abstract: The mass spectra of the following acetylenic derivatives of iron, ruthenium and osmium carbonyls are reported: the iron compounds Fe2(CO)6[C2(C6H5)s2]2, Fe2(CO)6[C2(CH3)2]2 and Fe2(CO)6[C2(C2H5)2]2, the ruthenium compounds Ru2(CO)6[C2(C6H5)2]2, and Ru2(CO)6[C2(CH3)2]2 and the osmium compounds Os2(CO)6[C2(C6H5)2]2, Os2(CO)6[C2HC6H5]2 and Os2(CO)6[C2(CH3)2]2. Iron compounds exhibit breakdown schemes where binuclear, mononuclear and hydrocarbon ions are present. On the other hand, ruthenium and osmium compounds fragment in a similar way and give rise to singly and doubly charged binuclear ions. Phenylic derivatives of ruthenium and osmium also give weak triply charged ions. The results are discussed in terms of relative strengths of the metal-metal and metal-carbon bonds.