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E Crivellato

Publications and source records attributed to E Crivellato.

At least 55 records · Page 3Linked to original sources
PubMed1997

Adriamycin binds to the matrix of secretory granules during mast cell exocytosis.

The antineoplastic drug adriamycin induces exocytosis in rat peritoneal mast cells followed by a significant uptake of the drug into the secretory granules. The drug is fluorescent, allowing visualization of its accumulation and binding to mast cell granules by fluorescence microscopy. At the same time, the well known inorganic dye ruthenium red was used as a probe because of its great affinity for heparin in the mast cell secretory granules as visualized by bright field microscopy. Competition between adriamycin and ruthenium red for binding to the negatively charged matrix of granules was demonstrated. Biochemical studies were also performed to confirm microscopic observations. Adriamycin may be of interest for studying mast cell secretion; it is not only a strong fluorescent dye for mast cell granules that are in communication with the extracellular space, but it also induces mast cell exocytosis.

Animals↗
PubMed1994

Visualization of PGP 9.5 immunoreactive nerve terminals in the mouse snout epidermis.

Intraepidermal free nerve endings were investigated in the mouse snout skin by means of an immunohistochemical procedure using a rabbit antiserum against protein gene product 9.5 (PGP 9.5). Immunoperoxidase reactivity was detected in different subtypes of intraepidermal nerves and cells. The great majority of axons observed in the stratified epithelium were varicose; a small percentage was either smooth (non-varicose) or irregularly shaped. Intraepidermal nerves ended at different levels within the epidermis, often with a terminal knob-like swelling. Various patterns of intraepidermal innervation could be distinguished. Most fibres entering the epidermis originated from large bundles running a horizontal course below the dermo-epidermal junction. Such fibres ascended vertically through the stratified epithelium in a "candelabrum-like" fashion, without emitting collaterals. Other fibres branched profusely and ended in complex intraepidermal neural networks. Less frequently, intraepidermal fibres terminated with large irregularly shaped expansions of different morphologies. Some of these were the intraepidermal continuations of axons within Meissner's corpuscles. Some fibres appeared to come into contact with PGP 9.5-immunoreactive cells (which closely resembled Merkel cells) located in the stratum basale. Rare suprabasal dendritic cells (Langerhans cells?) also became visible.

Animals↗
PubMed1992

Serotoninergic fibres form dense synaptic contacts with Purkinje cells in the mouse cerebellar cortex--an immunohistochemical study.

The distribution of serotonin immunoreactivity in the mouse cerebellar cortex was studied using the indirect antibody peroxidase-antiperoxidase (PAP) technique of Sternberger (1979) on epoxy embedded semithin sections. The great majority of serotonin-positive afferents distribute throughout the Purkinje cell layer and form dense synaptic contacts with the somata of the Purkinje neurons. Only a sparse immunostaining of serotoninergic fibres could be detected at the granular cell and molecular layers. The microanatomical organization of the serotoninergic projections to the mouse cerebellar cortex is quite different from that observed in other animal species. These findings suggest that in the mouse cerebellar cortex, the Purkinje cell population represents the main target for serotoninergic afferents. Our histochemical data provide morphological support for a series of electrophysiological observations which indicate serotonin as a potential modulatory neurotransmitter for Purkinje cell firing activity.

Animals↗
PubMed1991

Effect of the carboxylic ionophore monensin on histamine release from rat peritoneal mast cells.

The effect of the monovalent carboxylic ionophore monensin, which mediates a one-for-one exchange of intracellular H+ for extracellular Na+, was investigated in purified rat peritoneal mast cells. Monensin inhibited histamine secretion induced by compound 48/80, adriamycin and the calcium ionophore A23187; the inhibitory effect was maximal when the compound was added at least 10 min before the secretagogues. Washing of cells before addition of the secretagogues did not abolish the inhibitory effect of monensin. On the contrary the carboxylic ionophore was completely ineffective in preventing concanavalin A-induced histamine release. When rat peritoneal mast cells were incubated in the presence of monensin for longer period (up to 5 hours), the substance induced a slow, progressive and dose dependent histamine release, which, at least for lower doses was noncytotoxic. The secretory effect of monensin was still present if the ionophore was washed away after 10 min of incubation, and the incubation continued in drug-free medium. Monensin stimulated histamine secretion was strictly dependent on extracellular Na+ concentrations, and independent on extracellular Ca++.

Animals↗
PubMed1991

Suggestive evidence for a microanatomical relationship between mast cells and nerve fibres containing substance P, calcitonin gene related peptide, vasoactive intestinal polypeptide, and somatostatin in the rat mesentery.

A close microanatomical relationship between serotonin-positive mast cells and nerve fibres positive for substance P, calcitonin gene related peptide, vasoactive intestinal polypeptide, and somatostatin has been observed in whole-mount preparations of rat mesentery by an immunofluorescent double-staining procedure. Peptidergic fibres have been shown either to run in close proximity or come in direct contact with mast cells. This supports earlier morphological and immunohistochemical results suggesting an innervation of mast cells and provides a structural foundation for a series of pharmacological studies which outline the influence of various neuropeptides on mast cell secretory activity.

Animals↗
PubMed1990

Comparison between the L-DOPA histofluorescence procedure and the indirect immunofluorescence with anti-T6 and -HLA-DR monoclonal antibodies in visualizing Langerhans cells of human epidermis.

In order to assess the reliability of the L-DOPA histofluorescence (HF) procedure in visualizing the Langerhans cells (LC) of human epidermis, serial sections of human normal skin samples have been incubated with L-DOPA and alternatively processed for the L-DOPA HF and the indirect IF with anti-T6 and anti-HLA-DR monoclonal antibodies. Results demonstrated a good correlation of LC labelling; comparison between the number of L-DOPA positive (T6 positive and L-DOPA positive) HLA-DR positive dendritic cells did not show statistically significant differences. Therefore, the L-DOPA HF represents a valuable method for detecting LC in the human normal epidermis.

Adult↗
PubMed1990

Osmium-zinc iodide reacts with interdigitating cells in the mouse lymph nodes and spleen.

It is known that epidermal Langerhans cells react with osmium-zinc iodide (ZIO) mixtures; therefore they can be visualized by this histochemical method. In the last few years it has been shown that Langerhans cells are closely related to the class of interdigitating cells (IDC) which are antigen presenting cells located in the T-dependent areas of lymph nodes and spleen. In this study the reactivity of murine IDC to ZIO has been assessed. Results demonstrate that ZIO procedure yields to a brilliant and selective staining of IDC. The reactivity pattern is quite similar to that previously observed in epidermal Langerhans cells. This finding gives further support to the concept that Langerhans cells and IDC are closely interrelated cell types.

Animals↗
PubMed1990

A ruthenium red-toluidine blue procedure for staining epoxy sections in the light microscopy.

Ruthenium red (RR) has been widely used as a fixation additive for electron microscopy on the basis of its capacity to retain acid mucopolysaccharide residues of the cell surface coat. Little is known about the properties of this compound as a direct staining agent for epoxy-resin embedded material. In this study, semithin sections of Epon-infiltrated muscle tissue samples have been treated with 1% RR followed by counterstaining with 1% toluidine blue. This 2 step staining procedure has proven to be simple, rapid, and reliable and to give a dramatic improvement in image resolution and contrast. Thus, we believe that histochemical procedures employing RR may find in the future interesting applications for the direct staining of epoxy-resin embedded tissues.

Animals↗
PubMed1989

Demonstration of phenolic compounds in plant tissues by an osmium-iodide postfixation procedure.

A simple procedure to stain phenols in plant tissues is described. Postfixation with an aqueous solution prepared by mixing 2 cc of 2% osmium tetroxide and 8 cc of 3% potassium iodide yields brilliant visualization of phenol-containing vacuoles in different tissues of plants (e.g., coffee, oak, tobacco and spruce) bearing high concentration of phenolic compounds. Areas bearing phenols become dark gray to black. Chemical experiments demonstrate that osmium-potassium iodide (Os-KI) mixture reacts rapidly with several naturally occurring plant phenols, developing black solutions from which black solids precipitate. Phenols containing omicron-dihydroxy groups react with Os-KI solution more rapidly than other structurally different phenols. Therefore, omicron-dihydroxy units in an aromatic ring seem to function as primary sites of reactivity with the osmium-iodide complexes.

Histocytochemistry↗
PubMed1989

Visualization of the Langerhans cells in the human vaginal epithelium by the L-dopa histofluorescence method.

In this study we used the technique of L-DOPA histofluorescence for visualizing Langerhans cells in the human vaginal epithelium. Biopsy specimens were incubated with L-DOPA and sectioned by cryostat. The sections were exposed to formaldehyde vapour; during this passage, chemical conversion of L-DOPA into a strongly fluorescent compound occurred. Langerhans cells were clearly visualized in the vaginal epithelium; cell bodies and dendritic processes fluoresced sharply. The method is rapid and specific: it represents an useful tool for demonstrating Langerhans cells in the stratified squamous epithelium of vagina.

Adult↗
PubMed1987

HLA-B39 and the axial type of psoriatic arthritis.

The frequency distribution of HLA-B38 and HLA-B39 was studied in a group of 50 unrelated psoriatic arthritis patients. A high increase of HLA-B39 was noted in the subgroup with axial arthropathy. All B39 positive patients presented with spondylitis and/or sacroiliitis. The hypothesis is formulated that HLA-B39 may discriminate a genetic subset of psoriatic arthritis characterized by a particular susceptibility to develop axial involvement.

Arthritis↗
PubMed1986

Disseminated nevus anelasticus.

A 23-year-old man presented with a diffuse and fine wrinkling of the skin of his back and trunk. Skin lesions had first appeared about 5 years earlier and resulted from coalescing of multiple, flat, pinkish-red papules, a few millimeters in diameter. A diagnosis of widespread cutaneous elastic hamartoma was made. Histology revealed a focal disappearance of elastic fibers within circumscribed areas of the dermis. The pattern of the dermal collagen and reticulin was normal. No concomitant changes in the bone density were recognized by x-ray, excluding the Buschke-Ollendorff syndrome. Therefore, we call this case "disseminated nevus anelasticus."

Adult↗
PubMed1986

Association between HLA-B16 and psoriatic spondylitis.

The frequency distribution of HLA antigens was studied in a group of 40 patients with psoriatic arthritis from a region in North-eastern Italy. Our results indicate: 1) a strong association, in this population, between HLA-B16 and inflammatory spinal involvement; 2) a failure to confirm previous reports on HLA-B27 increased frequency in psoriatic spondylitis and/or sacroiliitis.

Female↗
PubMed1983

Bilateral follicular basal cell nevus with comedo-like lesions.

A 12-year-old white boy presented with symmetrically appearing papular, nodular, comedo-like, highly itching lesions involving the skin on his ankles. They had first appeared 3 years earlier. Numerous cutaneous biopsies showed tumoral buds of basalioma cells associated with follicular structures, infundibular cysts and also hypertrophy and hyperplasia of sebaceous glands. To the best of our knowledge, there are no reported cases with the same clinical and histopathological findings as in those reported here. We believe the lesions represent a "bilateral follicular basal cell nevus with comedones".

Ankle↗