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Biomedical subjects

G Vannelli

Publications and source records attributed to G Vannelli.

At least 19 recordsLinked to original sources
PubMed1998

Presence and location of endothelin and endothelin-binding sites in human nasal mucosa under normal and metaplastic conditions.

The presence and site of production of endothelin-1 (ET-1) was investigated in biopsies obtained from the nasal mucosa of 10 healthy human subjects and 10 patients affected by chronic rhinitis. The presence and localization of receptors for ET-1 was also investigated. Bioptic fragments were examined by scanning electron microscopy. ET-1 was present in the vessels and in the respiratory epithelium of normal subjects, whereas in patients affected by epithelial metaplasia induced by chronic rhinitis, it was absent in the metaplastic epithelium and present in the endothelium and vascular wall. Receptors for ET (A- and B-receptor subtypes) were localized in the vessels of the nasal mucosa, both in normal and in pathological subjects. In particular, A-receptors were identified in the vascular wall, whereas B-receptors were mainly distributed in the endothelium. We suggest that ET-1 is involved in the homeostasis of nasal blood flow (shunting the blood toward the deep cavernous plexus and inducing mucosal swelling) by an autocrine and/or paracrine mechanism. Normal epithelium seems to be important in this mechanism, since it is able to produce ET. However, when pathologic conditions induce squamous or cuboidal metaplasia, the epithelium is no longer able to play this role.

Adult↗
PubMed1993

Skin wound healing: some biochemical parameters in guinea-pig.

Hairs were removed from the dorsal skin of guinea-pigs and 5-6 wounds (7 x 7 mm) were surgically induced by totally removing the epidermal and part of the dermal surface. They were then allowed to heal. The newly formed wound tissues were dissected at different times during the process and analysed by biochemical and histological methods. Hydroxyproline, proteins, DNA and semicarbazide-sensitive amine oxidase (SSAO) were measured, as were [14C]leucine and [3H]thymidine incorporation in some samples. The peroxidase-like activity of plasma albumin and the histology of wounds stained with haematoxylin-eosin were also studied. It was shown that SSAO enzymes, which are present in normal guinea-pig skin and have a high affinity for benzylamine are localized in fibroblasts. During skin healing in the newly formed tissue there was an increase in protein content which reached a maximum after 4-6 days; DNA content also increased. The rate of incorporation of [3H]thymidine and [14C]leucine paralleled DNA and protein content, respectively. The content of hydroxyproline had greatly decreased with respect to that in normal skin after 2-10 days. SSAO activity increased much less than DNA after 4 days whereas after 10-11 days it increased more than DNA, thus indicating that at this time it was probably produced by fibroblasts. No significant increase in the peroxidase-like activity of albumin was observed 4, 8 or 11 days after surgery. Treatment of the animals with methylprednisolone acetate (20 mg kg-1, i.m.) two days before surgery decreased the rate of skin healing but did not alter the level of albumin peroxidase activity of the plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

Amine Oxidase (Copper-Containing)↗
PubMed1992

A large inbred Palestinian family with two forms of muscular dystrophy.

This paper reports the results of a clinical, genetic and histopathological study of 19 patients belonging to a large inbred Palestinian family living in Um-El-Fahem, a town located in Israel, which is solely inhabited by Arabs. Their custom of marrying only among relatives has kept the genetic homogeneity of the families intact. There were ten cases of congenital muscular dystrophy (CMD) and nine cases of adult limb-girdle muscular dystrophy (LGMD) belonging to two generations of the same family. Both forms showed autosomal recessive inheritance. The patients with congenital muscular dystrophy had generalized muscular weakness and hypotonia at birth without arthrogryposis or CNS involvement and then had a relatively benign evolution with stabilization of the clinical picture at different ages and variable degree of severity. Muscle biopsy showed a dystrophic pattern. The other nine patients presented with the picture of adult limb-girdle muscular dystrophy but with an unusual tendency to the stabilization of symptoms.

Adolescent↗
PubMed1983

[Effects of prolonged administration of morphine on the estrus cycle of the rat].

Ten female rats, of the age of three months, were treated for 24 days with increasing doses (10 mg/kg daily in the first week, 20 mg/kg in the second week, 30 mg/kg in the third week and 40 mg/kg in the last three days of treatment) of morphine acetate injected intra peritoneum, in order to cause a chronic intoxication (13). Five rats were utilized as controls. In all cases the vaginal smears was daily examined in order to evaluate the possible changes induced by the drug administration. The results obtained show that morphine produces important alterations in the estrous cycle of all the treated animals. In fact from the second day of treatment all animals had the cycle blocked in metaestrous. Afterwords a great variability occurred with a complete lack of estrous for the whole experimental period in five rats and very irregular succession and length of the phases into other ones. After the interruption of the treatment a resumption of the normal cycle was observed.

Animals↗
PubMed1982

[Effects of nitrous oxide on the female gonad in the rat].

Female rats have been exposed (24 hours for 15 days) to N2O 60% in normo-oxic blend of N2 and O2. Vaginal smears have been observed daily. At the end of the experiment the ovaries have been removed and the following morphological parameters have been statistically evaluated: number of evolutive follicles and corpora lutea, amount of interstitial tissue. Our results seem to account for a remarkable toxic effect of N2O on the rat gonad. Such effect is testified by alterations of the oestrous cycle and, at the ovary, a decrease in the number of evolutive follicles and functioning corpora lutea and by a sharp increase of atretic phenomena.

Animals↗
PubMed1980

[Structural and ultrastructural features of the skeletal muscle in Werdnig-Hoffmann disease].

In researches performed on striated muscles of individuals affected by various myopathies, fragments of gastrocnemius muscle in course of Werdnig-Hoffmann disease have been studied. The light microscopic observations demonstrate the presence of numerous, very thin, atrophic fibres with many irregularly lobated and packed nuclei alternating with apparently normal fibres with lighter and larger nuclei. The connective part of the muscle appears to be remarkably increased and replaces the atypical contractile tissue. The electron microscope shows, in the atrophic fibres, remarkable alterations of the sarcoplasmatic elements, and a complete disarrangement of myofibrils and myofilaments, some of which are anchored to fragments of the Z bands, irregularly arranged. Even the normal orientation of the sarcomeres often with indefinite bound, is upset. The numerous lobated nuclei totally occupy the irregular protrusions of the sarcoplasm, rich in peripheral microvesicles. In respect of other examined myopathies, in which the muscle fibres alterations affect limited parts of the contractile elements, in these cases the modifications seem to be of greater entity and to affect completely single muscle fibres.

Cytoskeleton↗
PubMed1980

[Phospholipidosis induced by chlorimipramine in rat lung].

12 male Sprague-Dawley rats were given chlorimipramine through gastric sound at a daily dose of 150 mg/Kg body weight for two weeks. From the rats, killed at the end of the treatment, were collected lung fragments, some of which were examined by electron microscopy and others by light microscopy, following particular fixation and colouring procedures. The light microscopy revealed that many alveoli contained numerous cells, large and clear, the cytoplasma of which contained vacuoles of different dimensions, for which these cells appeared from " foam cells". Besides, they reacted positively to the method of Baker and were intensely coloured in dark grey, after fixation with osmium tetroxide-natrium iodide. The ultrastructural examination evidentiated two main types of cells: the first comprised large, round cells, classifiable as alveolar macrophages while the second type comprised cells that were classifiable as type II alveolar cells, in which, apart from important mitochondrial modifications, numerous vacuoles of different sizes were detectable. The AA. consider the alterations of the type II alveolar cells as a characteristic morphological aspect of phospholipidosis from chlorimipramine.

Animals↗
PubMed1979

[Ultrastructural observations on choroid melanoma].

Twelve melanoblastomas of the choroid of different histological types have been studied in the semi-thin sections and at transmission electron microscope. There have been also observed at scanning electron microscope. The ultrastructural findings show some differences in the main cellular types as observed at light microscope by Callender (spindle-shaped cells A and B and epithelioid). In the epithelioid and spindle-shaped B cells a higher number of ribosomes and of mitochondria and large, polymorphous, often multiple nucleoli with reticular structure are observed. There findings may be related to a greater metabolic activity and anaplastic tendency of these cells. Moreover in spindle B - and epithelioid - cell types atypical melanogenesis and nuclear bodies are particularly evident. Scanning electron microscope show well developed cytoplasmic extensions in spindle cells.

Choroid Neoplasms↗
PubMed1979

[Further observations by electron microscope of striated muscle in progressive Duchenne muscular dystrophy].

Gastrocnemius muscle fragments of children affected by clinically diagnosed progressive muscular dystrophy of Duchenne have been studied. At the light microscope, in the semi-thin sections, the more evident changes are represented by a wide diameter range of the fibers and fatty infiltration. Some fibers show numerous nuclei in their central part, a sarcoplasmic degeneration of vacuolar type and an irregular and tortuous course of the myofibrils. Moreover, the ultrastructural findings have shown characteristic changes in myofilaments and Z bands represented by: streaming of the Z bands, collection of the triads and concentric laminated bodies. These observations have pointed out a certain gradualness of the alterations, starting from focal changes of Z band to the complete disarrangement of myofilaments.

Child↗
PubMed1979

[Study of uveal malignant melanoma with the electron microscope (author's transl)].

Twelve cases of uveal malignant melanoma, including the principal histologic types of this neoplasm according to Callender, were studied with the electron microscope. Nuclear inclusions were observed in each case, more frequently in epithelioid cells: they were probably correlated with nuclear hyperactivity. Melanogenesis in neoplastic cells was sometimes abnormal because of the granular structure of the premelanosomes, of the difference in size and in shape melanosomes, of the difference in size and in shape of the pigment granules and of the different stage of evolution of the premelanosomes in the cell. The size and the degree of reticulation of nucleoli and the number of free ribosomes and mitochondria increased from spindle A, to spindle B and epithelioid cells. This behaviour probably depends on an increasing metabolic activity which is related to the increasing degree of malignancy.

Adult↗
PubMed1979

[Scanning electron microscopy in malignant uveal melanomas (author's transl)].

Four malignant uveal melanomas, of which two were of fascicular (subtype B) type one of epithelioid type and one of mixed-type, were examined under a scanning electron microscope. Within the tumors, we can distinguish cells having long cytoplasmatic processes and cells without processes, which correspond to the fusiform and epithelioid cells respectively. The cells also show a more or less marked development of the microvillosities of the cell surface.

Adult↗