Biomedical subjects

M Lorenzi

Publications and source records attributed to M Lorenzi.

111 records · Page 7Linked to original sources

PubMedDate not supplied

Histopathological and prognostic evaluation of immunohistochemical findings in colorectal cancer.

Many immunohistochemical studies have investigated the relationship between immunohistochemical characteristics and histopathological findings in colorectal tumors. One of the most extensively studied markers has been tissue CEA, although the prognostic significance of this and other antigens is still uncertain. The authors report results relative to three tumoral antigens (carcinoembryonic antigen, CEA; tissue polypeptide antigen. TPA, and carbohydrate antigen 19-9, CA 19-9) determined by immunohistochemical methods in tissue samples of 52 colorectal carcinomas. The relationship between the immunohistochemical characteristics of the neoplasms and the clinicopathologic parameters, as well as their influence on the prognosis of the patients, were examined. Positive CEA reaction has a significant relationship with grade of differentiation of the tumor while diffuse cellular expression of this antigen often indicates neoplasms extending beyond the intestinal wall and invading the lymph vessels. The number of tissue antigens expressed is significantly related to the extent of tumor spread through the intestinal wall. A greater incidence of recurrence and shorter disease-free interval and survival were observed in neoplasms that expressed tissue TPA antigen or more than one tissue antigens. In the present study the latter parameter has demonstrated to have independent prognostic significance for the disease-free interval. Immunohistochemical evaluation of antigens in colorectal carcinoma tissue shows a possible independent prognostic value of the antigenic heterogeneity of tumors, which could be related to their different biological behavior.

Adult↗

PubMedDate not supplied

[Arterial supply in the left colonic flexure].

The authors study the behaviour of the middle colic, left colic superior, middle and inferior and the first sigmoidal arteries in the territory of the terminal portion of the transverse colon, the left colonic flexure and the descending colon. The study was carried out on 1200 angiographies of the superior and inferior mesenteric aa. and on 150 anatomical specimens, surgically extirpated in the course of left emicolectomy operations. Contrary to what is believed by most authors, the left flexure is a colonic tract very well supplied by blood while the descending colon results to be poorly supplied, being served only by one artery (the left sup. colic a.) often of limited caliber and with branches (the middle and the inf. left colic aa.) sometimes totally or partially lacking. In this last colonic tract the vascular continuity, represented by the arterial arcades, is often interrupted. The Riolan's arcade, variously shaped, is to be considered a constant vascular structure (only once it was lacking in this study). Sometimes it is doubled by a second more internal arcade which must not be confused with the intermesenteric arcade. In four of the observed cases, the Riolan's arcade resulted strengthened by a second retroperitoneal arcade, derived from a branching of the middle colic a., whose branches of division went to the two colonic flexures and descended along the postero-lateral walls of the ascending and descending colon, often parallel to the regular abdominal branches. Exceptionally the colonic flexure is supplied by the only left colic a., which behaves as a specific artery, by us called "dominant artery". The central branches of the artery go to the flexure while the lateral ones join the branches of the middle colic and the first sigmoidal aa., effecting tenuous connections, surgically unreliable. In this case the arterial continuity of the Riolan's arcade can be considered interrupted, at least for the surgical practice. The intermesenteric arcade, in its three forms (direct, mixed and indirect), was observed in 20% of the cases. The colic marginal a. is considered by the authors a tier of arches formed by the colic aa. The left colonic flexure is also supplied by particular vessels originated from the middle colic and the left colic aa. (angular branches and arcades and bridge-branches) or from the superior mesenteric a. (angular artery of Donati) and from other sources, particularly from the splenic a. These vessels then join the colic "vasa recta" through the phrenocolic ligament and the marginal omental vessels. This research shows that the vascular continuity of the left colon is not a constant element, able to reassure the surgeon, for possible interruptions that may occur in its composition.

Colon↗

PubMedDate not supplied

[Surgical treatment of pancreatic carcinoma. Our experience].

BACKGROUND: Currently, pancreatic exocrine carcinoma presents high mortality, poor survival after curative surgery and poor resectability rates at the time of diagnosis. The factors which mostly influence prognosis and therapeutic management (curative surgery or palliative treatments) of the patient affected by pancreatic carcinoma, particularly the peroperative stage, are analyzed and discussed in this article. METHODS: From 1969 to 1997, 142 patients with pancreatic ductal carcinoma were admitted to our Department: at the time of diagnosis only 32 patients (22.5%) were considered resectable, and 30 pancreaticoduodenectomies (PD), 1 distal pancreatectomy (DP) and 1 total pancreatectomy (TP) were performed. RESULTS: Postoperative morbidity and mortality was 53.1% and 12.5% respectively; the survival at 1, 3 and 5 years was 45.5%, 36.4% and 17.6% respectively. The worst prognosis was seen in N+ and T4 patients, with a mean survival of 9 and 10 months. CONCLUSIONS: On the basis of these results and of the literature, the indications for curative surgery, the operative strategy and the lymphoadenectomy extension are discussed: these problems are still open and not resolved definitively. The authors conclude by indicating the need for curative surgery for T1/2 N0 M0 tumors: for T3/4 and/or N+ tumors a careful evaluation of single case is necessary, because of high risk/benefit rate. Pancreatic resections (PD, DP) and standard lymphoadenectomy (D1) are performed by the authors, rather than total pancreatectomy and radical lymphadenectomy (D2-3).

Adult↗