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Biomedical subjects

G Stabellini

Publications and source records attributed to G Stabellini.

At least 55 records · Page 3Linked to original sources
PubMed1994

Human leukemic pre-B line (KM-3) treated with phorbol-ester: trend of polyamines during cell differentiation.

Aliphatic polyamines, putrescine, spermine and spermidine present in bacteria and eukaryotic cells are essential for cell growth. Generally, polyamine levels are elevated in rapidly growing normal and pathological systems. Since polyamines belong to the category of molecules whose synthesis is strongly activated during the G1 period they have been implicated in the cell's preparation for DNA replication. In our experiments, we have differentiated by phorbol-ester, the human pre-B leukemic cell line KM-3. Biochemical and flow cytometric analysis show an increase, in treated cells, of polyamines pathway related to G1 and early S-phase of cell cycle during B cell differentiation.

B-Lymphocytes↗
PubMed1992

An evaluation of the mechanisms developmentally involved on cellular and extracellular glycosaminoglycans accumulation in chick embryo skin fibroblasts.

1. Ammonium chloride, a lysosomotropic amine known to inhibit lysosomal function, was administered to 7-day cultured and 14-day chick embryo skin fibroblasts to evaluate the relationship between synthesis, degradation and uptake of glycosaminoglycans (GAG). 2. Following amine treatment, the amount of 3H-glucosamine and 35SO4 labelled cellular GAG increased, was more at 14 days than at 7 days. Hyaluronic acid (HA) incorporation was mainly interested at 7 days and that of sulphated GAG at 14 days. 3. The extracellular accumulation declined proportionally to the cellular increase of undegraded GAG. HA was mainly affected at 7 days and sulphated GAG at 14 days. 4. The amine did not change 3H-HA uptake and it was unable to inhibit its degradation. 5. The products of degradation of uptaken 3H-HA were retained inside the cell. Those released by degradation of newly synthesized GAG flowed out of the cell.

Animals↗
PubMed1992

Effects of spermidine synthase inhibition in cultured chick embryo fibroblasts.

The administration of bis-cyclohexylammonium sulfate (BCHS), a spermidine synthase inhibitor, to in vitro cultures of chick embryo fibroblasts caused a decrease in cellular spermidine levels and an increase in putrescine and spermine. Cell proliferation rate and DNA synthesis were also inhibited. As protein synthesis did not change, it would seem that low levels of cellular spermidine inhibit cell growth depressing DNA synthesis.

Animals↗
PubMed1992

In vitro evaluation of plasticizer activity on the growth and metabolism of chick embryo fibroblasts and on the development of chick embryo lungs.

Administration of di(2-ethylhexyl) phthalate (DEHP) to primary cultures of chick embryo fibroblasts brought about a decrease in cell proliferation rate after 48 h and an inhibition of both DNA and protein synthesis measured by [3H]thymidine and [3H]leucine, respectively, after 48 h. The growth of chick embryo lung rudiments in vitro was also depressed by DEHP treatment. Lung rudiment were smaller in DEHP-treated embryos after 6 days' treatment. These results indicate that DEHP has a cytostatic effect on embryonic cells and tissues.

Animals↗
PubMed1991

Cyclosporin A, effect on cytoskeleton and glycosaminoglycans in human gingival fibroblasts. Immunohistochemical and biochemical evaluation.

The effect of Cyclosporin A (CyA) in culture of human gingival fibroblasts was assessed. Extracellular and intracellular glycosaminoglycans decrease in treated cells. The ratio of non sulphated over sulphated GAGs (glycosaminoglycans) increased only in the medium. Cytoskeleton organization of treated fibroblasts was also studied by immunohistochemical means and by ultrastructural observations. Minor alterations were documented in the structure and distribution of cytoplasmic organelles. The organization of tubulin and vimentin filaments did not change in Cy A treated cells either. This study confirms the capability of Cyclosporin A to induce alterations of GAG production and synthesis with no interference in cytoplasm organization. Normal pathway GAG secretion is suggested.

Adult↗
PubMed1990

Age-related changes in hyaluronate uptake by cultured fibroblasts.

Skin fibroblasts from chick embryos of 7 and 14 days incubation have been tested for their ability to bind, internalize and degrade [3H]-hyaluronan. Seven-day fibroblasts internalize and degrade a greater amount of labelled hyaluronan than 14-day cells. The implications of these findings in the regulation by the fibroblasts of extracellular matrix composition in glycosaminoglycans are discussed.

Animals↗
PubMed1990

Henoch-Schönlein purpura after Salmonella hirschfeldii infection.

The authors present a case of Henoch-Schönlein purpura in a young soldier (19 years old) which they consider important for its etiology and the length of its oligoanuric phase. The syndrome followed a Salmonella hirschfeldii infection, and a protracted oligoanuric phase was followed by nephrotic syndrome and selective glomerular proteinuria which lasted for 1 year. The young man recovered after the eradication of the Salmonella. It seems possible that there was an overall anomalous regulation of the 'lymphoid system of the mucosa', perhaps dependent on a genetic predisposition.

Adult↗
PubMed1990

Acquired ciliary defects in bronchial epithelium of patients with chronic bronchitis.

In order to quantify and classify ciliary changes of bronchial epithelium in chronic bronchitis, an ultrastructural study on biopsy specimens of 30 patients submitted to bronchoscopy was performed. Fourteen patients were affected by endoscopically and clinically confirmed chronic bronchitis, 8 showed an endoscopic picture of chronic bronchitis but without the clinical features of this pathology, 8 were free of chronic bronchitis. The mean percentage of abnormal cilia in control subjects (1.9 +/- 1.0%) was significantly lower than in patients either with only 'endoscopic' chronic bronchitis (5.7 +/- 2.6%; p less than 0.001) or with 'clinical' chronic bronchitis (14.8 +/- 15.9%; p less than 0.05). Like the ciliary body, the ciliary tip can also show some abnormalities. It is possible to subdivide them in two types: (1) ciliary membrane blebs; (2) ciliary membrane extrusions, variously shaped and sized, with homogeneous content. Bronchial cilia abnormalities become more serious as soon as the clinical picture worsens and this is likely to contribute to the impairment of the mucociliary clearance in chronic bronchitis patients.

Adult↗
PubMed1990

[Clinical importance of echographic screening of the entire abdomen].

Unsuspected abnormalities are occasionally detected during real-time examinations. To determine the frequency of such findings detected during the standard ultrasound examination of the entire abdomen, the records of 765 consecutive patients were reviewed. A significant number of occult abnormalities were detected: approximately one-fourth of all abnormalities were found in the abdominal survey. The influence of the abdominal survey on the clinical management and improved radiological consultation are discussed.

Abdomen↗
PubMed1989

Gastric metaplasia in duodenal bulb and Campylobacter-like organisms in development of duodenal ulcer.

Multiple biopsies were taken from 50 patients with endoscopic appearance of duodenitis in order to study the relationship between gastric metaplasia in duodenum and the presence of Campylobacter-like organisms (CLOs) and the development of duodenal ulcer disease. Metaplasia was found in at least one biopsy specimen from 46 of the 50 patients; CLOs were seen in 25 of the 50 patients, only in metaplastic areas. In four cases a "transitional epithelium" with the presence of cells containing few apical mucoid granules and absorbent-type brush border as well as goblet cells was seen. In two cases, this epithelium was colonized by a small number of CLOs. Gastric heterotopia appears to be a rare condition.

Adult↗
PubMed1989

Exogenous glycosaminoglycans modulate extracellular and intracellular accumulation of newly synthesized glycosaminoglycans by embryonic chick skin fibroblasts.

The effects of exogenous glycosaminoglycans (GAG) on newly synthesized GAG accumulation in intra- and extra-cellular compartments of 17 incubation days chick embryonic skin fibroblasts have been examined. Exogenous GAG are able to act on both total GAG synthesis and secretion by embryonic fibroblasts and on the relative concentration of individual GAG. A decline in hyaluronic acid and an increase in chondroitin sulfate plus dermatan sulfate in the cellular compartment for all GAG administered have been detected. There was also similar behaviour in the extracellular compartment after sulfated GAG administration.

Animals↗
PubMed1989

Campylobacter-like organisms, nonsteroidal anti-inflammatory drugs and gastric lesions in patients with rheumatoid arthritis.

A histological study was performed in order to evaluate the prevalence of Campylobacter-like organisms (CLO) and gastric antral lesions in 85 rheumatoid arthritis (RA) patients using NSAIDs, and in 100 nonrheumatoid outpatients comparable in terms of sex and age, not using NSAIDs. Histological evidence of gastritis was a common finding both in RA patients (88.2%) and in nonrheumatoid outpatients (89.0%). On the other hand, CLO were detected in a significantly lower proportion (p less than 0.001) of RA patients than outpatients (30.6 and 59.0%, respectively). Considering each NSAID used separately (aspirin, diclofenac sodium and ketoprofen), no significant difference in the presence of CLO in the three groups was found; in the small group of patients treated with aspirin, however, bacteria were never detected. MICs of each NSAID used against 15 isolates of Campylobacter pylori were also determined.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1989

[Optic, scanning and transmission electron microscopic observations of synthetic fibers implanted in rabbit skin].

Artificial hair made of synthetic leacryl fibre was inserted into the skin of a rabbit in order to evaluate the biocompatibility of the insertion of heterologous material. On the 7th and 30th day following insertion, samples were taken from the areas involved and were observed by MO, TEM and SEM studies. Granuloma in both the early stage (7th day) and later at 30 days was evidenced and found to develop to cicatricial sclerosis.

Acrylic Resins↗
PubMed1989

Patterns of physical modes of contact between Campylobacter pylori and gastric epithelium: implications about the bacterial pathogenicity.

Since the exact mechanisms of the pathogenicity of Campylobacter pylori are not known, we performed an ultrastructural study with the aim of focusing on patterns of possible physical contact between C. pylori and gastric epithelium, and of considering them in relation to the bacterial pathogenicity. Among 20 random consecutive patients referred for routine gastroscopy, we studied ultrathin sections from the 11 patients with Campylobacter-like organisms, and recognized three patterns of physical contact between bacteria and epithelial cells. These patterns seem in accord with published data of C. pylori toxicity, and they could represent different evolutive stages of the infection.

Campylobacter↗
PubMed1988

Developmental heterogeneity of mesenchymal glycosaminoglycans (GAG) distribution in chick embryo lung anlagen.

The presence and distribution of mesenchymal components in the extracellular matrix during lung development in the chick embryo (from 5 1/2/6 to 18 incubation days) has been examined histochemically. Attention is focused mainly on glycosaminoglycans (GAG). Morphological reconstructions show three main stages: first (5 1/2/6-8 days), formation of 2nd-order branching; second (9-12 days), proliferation of parabronchi and third (from 13th day on), formation of air capillaries. In the first phase, hyaluronic acid (HA) prevails around the mesobronchus, but chondroitin sulfate (CS) dominates the 2nd-order branches. Basement membranes of 2nd-order branches are strongly positive for sulphated GAG. In the second phase, CSA increases in the ground substance of mesenchyme. This increase is irregular, being smaller in older areas (mesobronchus, branches of 2nd order) and larger in the more recent parabronchi, which extend into the lateral and dorsal areas of the rudiment. An increase in both sulfated GAG and glycoprotein (GP) occurs in basement membranes. In the third phase, GAGs are uniformly distributed in the mesenchymal septa and around the interlobular vascular network. This concentration decreases while the GP concentration increases. Basement membranes around every branch of the 1st, 2nd, and 3rd orders possess large quantities of GP. Mesenchymal GAG occurs in every stage of lung development, temporally correlating with the morphogenesis and differentiation of epithelium. Our results provide necessary information, which has not been available so far. Experimental studies specifically designed to clarify the developmental significance of such a heterogeneous distribution may be interpreted in the light of this information.

Animals↗