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Biomedical subjects

L Pieri

Publications and source records attributed to L Pieri.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

Langerhans cells differentiation: a three-act play.

Langerhans cells are the dendritic cells typical of stratified squamous epithelia and enjoy an intermediate state of differentiation as dendritic cells, since they are very efficient in uptaking and processing antigens but poor in presenting them to lymphocytes. These cells, and other dendritic cells as well, differentiate from bone marrow precursors, with circulating monocytes as intermediates. Langerhans cells leave the epidermis upon loading with antigen and further differentiate into mature dendritic cells while moving to peripheral lymphoid organs, where they elicit primary immune responses. The signals regulating differentiation of precursors into Langerhans cells and of this latter cells into mature dendritic cells have been unraveled thanks to in vitro studies and include a wide range of cytokines, some of which can actively inhibit this process. Also pro-B cells and thymic precursors can give raise in vitro to mature dendritic cells, but apparently not to Langerhans cells. Keratinocytes, the principal cell type of epidermis and mucosal stratified squamous epithelia, can provide for a wide range of cytokines influencing the differentiation of cells of dendritic lineage, in particular Langerhans cells. These cytokines include GM-CSF and TNF-alpha, that may be relevant also for the maintenance of the differentiated state of Langerhans cells within epidermis. Cell to cell contacts mediated by E-cadherin may also contribute signals from keratinocytes to differentiating Langerhans cells. The epidermis and mucosal squamous epithelia host other cell types, besides keratinocytes, and nerve fibers, that all can contribute signals to differentiating Langerhans cells. The differentiation of Langerhans cells within the epithelial microenvironment of skin and mucosae most probably results from the interaction of several players, that play different roles on this scene in different physiological and pathophysiological conditions.

Antigens, CD34↗
PubMedDate not supplied

[Digital videoradiography applied to the study of the recto-anal region during defecography].

The authors have employed a real-time fluoroscopic computerized equipment during defecography. Digitalized images were acquired at a rate of three frames/s and then processed and became immediately available. Digital defecography was employed in 67 patients with various anorectal diseases--i.e., rectocele, descending perineum, rectal prolapse, non-relaxing puborectalis syndrome and fecal incontinence. We found time-interval difference (TID) technique especially useful for it allowed different functional phases of defecation to be depicted on a single subtracted image and an evaluation of the movements of anorectal region. The high contrast resolution of the computerized equipment demonstrated even minimal contrast medium leaks in fecal incontinence. The examination is easy and rapid to perform with a low radiation dose to the patients.

Defecation↗
PubMedDate not supplied

[Digital subtraction radiology in the study of mobile structures of the larynx].

Digital subtraction radiography (DSR) was applied to the study of the larynx in 11 healthy subjects and 15 pathological cases. The method, consisting in the subtraction of images obtained at rest and during phonation or respiratory phases, allowed a clear definition of the normal moving structures--i.e. vocal cords, false cords, pyriform sinuses, thyroid cartilage. Moreover, several pathological conditions could be demonstrated. DSR asserts thus itself as a suitable technique in the functional evaluation of the glottis.

Fluoroscopy↗
PubMedDate not supplied

[Diagnostic imaging of intestinal invaginations in the adult. Report of 9 cases].

Adult intestinal intussusception affects the distal portions of the small bowel and the colon in 90% of cases. As a rule, its nature is neoplastic, its clinical presentation aspecific and its diagnosis is frequently an occasional finding during routine imaging examinations. We report on 9 adult patients with intestinal intussusception. All patients were examined with more than one of the following imaging modalities: radiologic study of the small bowel, barium enema, ultrasonography (US), and Computed Tomography (CT). The first diagnostic suspicion of intussusception was correctly made at US in 5 patients and at CT in 4 patients. At surgery, intussusception sites were the following: jejunum in one case, ileum in two cases, ileocolon in two cases and colon in four cases. CT correctly detected lesion site in all the patients who underwent it as the first diagnostic step, while US missed lesion site in one case. Pathology diagnosed a hamartomatous jejunal polyp, a lymphomatous ileal polyp, a lymphomatous polyp of the ileocecal valve, four cecocolonic adenocarcinomas and a left colic lipoma. Lesion nature was suspected at US in one case of ileal lymphoma, while CT suggested the presence of lipoma in one case of ileoileal intussusception. Our experience shows that intussusception can be diagnosed not only with conventional radiologic modalities, but also with US and CT, which are useful to depict both the lesion and its site and extent.

Adult↗
PubMedDate not supplied

[The 3rd national workshop on defecography: the functional radiology of (neo) rectal ampullae (ileal reservoir, colo-anal anastomosis, continent perineal colostomy)].

A survey was made in 13 Italian centers with a questionnaire concerning the (a) indications, (b) postoperative complications, (c) functional results and (d) diagnostic imaging modalities related to the making of an ileal or colonic (neo) rectum. Ulcerative colitis (100%), familial polyposis (61.5%) and Crohn's disease (15.3%) were the most common indications for an ileal pouch; rectal cancer (7.96%), chronic inflammatory diseases (15.3%), diverticulosis, rectal prolapse, redundant colon and imperforate anus (7.6% each) were the most common indications for a colonic pouch. Postoperative complications included pelvic abscess (14%), sinus tract/dehiscence (10%) and bowel obstruction (9%). When compared with the S and W variants, the J-shaped ileoanal pouch proved superior because urgency and fecal retention rates were lower (18.4% vs. 44.4% and 23% vs. 28.6%, p < 0.01 and p < 0.05, respectively), despite slightly more frequent staining episodes (15.8% vs. 11.1%; p < 0.05). As for colonic ampullae, fecal retention and provoked evacuation were more frequent in the J pouch and after gracileplasty; urgency and incontinence in the straight colo-anal anastomosis (33.3% vs. 22.2% and 41.6% vs. 33.3%, respectively). The functional outcome was assessed by anal endosonography (available in 4/13 centers), defecography and anorectal manometry. Abnormal findings included: (a) reduced capacity, barium leakage, anal gaping, sphincter damage (urgency and incontinence); (b) barium retention, pouch dilatation, split evacuation, knobs and strictures (fecal retention).

Defecation↗