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Biomedical subjects

A Ciardi

Publications and source records attributed to A Ciardi.

49 records · Page 3Linked to original sources

Focused ion beam characterization of plasma-assisted deposition on polymer films at the nanoscale.

In this paper, a novel technique is presented for the characterization at the nanoscale of plasma-assisted deposit on polyethylene-terephthalate (PET) polymer films. In previous studies, some microcharacterization and morphology analyses of plasma-assisted deposition were performed by atomic force microscopy (AFM). In the work presented here, we analysed the thickness and homogeneity of plasma-assisted deposits by focused ion beam (FIB). This technique with 5-7 nm resolution requires no sample preparation and relies on a sequence of operations on a relatively fast time scale, so that it is easy to make thorough investigations of the sample. We performed electron and ion imaging of the surface of the material, and a subsequent ionic cutting allowed the study of the morphology of the same sample. We developed a novel approach to the edge detection techniques (EDT) in images for a fast evaluation and monitoring of the deposited layer.

Journal Article↗

A scanning transmission microscopy and energy-dispersive X-ray microanalysis of idiopathic ocular calcification and oxalosis in AIDS patients.

In a series of 98 consecutive eyeballs enucleated at postmortem from 86 patients dying with AIDS, the incidence of calcium deposits was 14 and 18.6%, respectively, for oxalates and calcium hydroxyapatite. The calcific eyes were examined by scanning electron microscopy (SEM) coupled with energy-dispersive X-ray microanalysis to confirm the elemental nature of the precipitates. Transmission electron microscopy was used in 2 of the cases with oxalosis. Oxalates with a free end exhibited a plate-like shape at SEM and appeared acicular at TEM, due to the reduced thickness of ultrathin sections. Crystals that were embedded in tissues such as the sclera or degenerate detached retinal tissue formed either spherules or plates at SEM. No clear relationship with intracellular structures could be found at TEM, possibly due to postmortem autolysis phenomena. Calcium hydroxyapatite deposits appeared at SEM as fine granules distributed over the collagen fibers of the corneal and conjunctival stroma and the scleral lamellae, but were also present intracellularly, both in the nucleus and cytoplasm of epithelial cells.

Acquired Immunodeficiency Syndrome↗

[Intestinal endometriosis. Three new cases and review of the literature].

OBJECTIVE: The study was undertaken to identify some features of the intestinal endometriosis such as symptoms, helpful investigations, pattern of distribution and surgical management. PATIENTS: Three consecutive cases, observed during a sixteen month period, are reported. The most frequent symptoms were chronic pelvic and abdominal pain, dysmenorrhea, alterated bowel habit and menorrhagia. The diagnosis of intestinal endometriosis was incidental in all but one case admitted for an intestinal subocclusive syndrome in patient with a past history of pelvic endometriosis previously documented by laparoscopy. RESULTS: All patients presented a sigmoid localization of endometriosis with different degree of stenosis and underwent sigmoid resection, followed by a resolution of abdominal symptoms. DISCUSSION: Although the exact frequency of intestinal endometriosis is difficult to know because of the lack of specific symptoms and reliable investigations, it has been estimated that implants to the bowel may occur in 3%-37% of women affected by endometriosis. The sigmoid colon is the most common site of localization. The main symptoms are pelvic pain, dysmenorrhea, infertility and diarrhoea or constipation; rarely patients present bowel occlusion due to stenosis (less than 15% of the cases) or cyclic rectal bleeding. CONCLUSION: Generally, intestinal endometriosis is not suspected preoperatively in those patients without a past history of this condition; however an accurate diagnosis can be provided throughout laparoscopy, before open surgery. The hormonal therapy is not successful in alleviating moderate to severe obstructive symptoms. Thus surgery still remains the most effective treatment for advanced intestinal endometriosis.

Adult↗

[Heterotopic erythropoiesis in liver transplantation].

Various conditions may restore hematopoietic activity in the adult liver. Of them, liver transplantation is of most interest. The causes and the mechanism of hematopoiesis restoral in liver grafts is not yet fully clarified. The Authors analyze the incidence of immature erythroid cells in a series of hepatic fine-needle aspiration biopsies performed in 28 patients with orthotopic liver transplant and in two clusters. The post-mortem liver examination, available in the two clusters, confirmed the ungoing hematopoietic activity.

Adult↗

[Cholestasis in liver transplantation: incidence and diagnostic significance].

Cholestasis is frequently encountered in human liver transplants. In a series of 82 liver fine-needle aspiration biopsies performed in 20 grafted patients, the incidence rate of cholestasis was 55%. Cholestasis may predominantly be localized in the hepatocyte cytoplasm, or in the biliary tree or in both sites. In our cases it was most frequently associated with acute rejection (53%), followed by preservation injuries (29%) and ciclosporin toxicity (12%), respectively. The severity and the chronologic distribution of cholestatic episodes seem to vary according to the other associated pathologic conditions.

Biopsy, Needle↗