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Biomedical subjects

U Valente

Publications and source records attributed to U Valente.

At least 73 records · Page 4Linked to original sources
PubMed1993

[Update on laparoscopic surgery: on the treatment of hydatid cyst of the liver and peritonitis caused by a perforated duodenal ulcer].

Laparoscopic surgery represents a real innovation with respect to the traditional laparotomic way of access, owing to its undeniable advantages, both intraoperative and postoperative. This new technique reduces the complications connected with the surgical wound and with forced allerement. Therefore it allows the patient's fast recovery. Laparoscopic surgery application ground get's wider and wider every day: in fact, the authors report two medical cases, one of elective surgery (treatment of a hidatid cyst of the liver) and the other in emergency surgery (peritonitis due to perforated duodenal ulcer), both obtaining a positive result about the clinical and the postoperative timing of recovery.

Duodenal Ulcer↗
PubMed1993

[Diverticulitis of the appendix: a rare cause of acute abdomen].

Diverticulosis of the vermiform appendix, either single or multiple, congenital or acquired, is rather infrequent and usually asymptomatic. However, it may be complicated by flogosis configuring an acute abdomen hardly recognizable from an acute appendicitis not related to the diverticular disease. The Authors report a case of acute appendicular diverticulitis surgically treated. A brief review of the literature is also reported.

Abdomen, Acute↗
PubMed1992

Isolation of pig pancreatic islets by a new method with hydraulic shaking: preliminary report.

The limited availability of human pancreas represents a serious problem in islet transplantation. In the past few years many efforts have been made to isolate pancreatic islets from large mammals in order to achieve valid and reproducible isolation methods. For several reasons swine may be considered an ideal source of islet tissue because of the similarity between human and porcine insulin and because of the easy availability of pig pancreata. Some papers have been published recently on this topic with good results. However, some problems, such as islet dissociation into single cells after collagenase digestion, are not completely solved. In this article, an automated method involving a hydraulic shaking system is described for islet isolation from the pig pancreas, developed in our laboratory and derived from Ricordi's model.

Animals↗
PubMed1991

Autoreactive lymphocytotoxic IgM antibodies in highly sensitized dialysis patients waiting for a kidney transplant: identification and clinical relevance.

The contribution of different families of lymphocytotoxic antibodies in the serologic reactivity of 45 highly sensitized dialysis patients (HSDP) (panel reactivity antibody value-PRA greater than 80%) was assessed by analyzing patients' sera for the presence of auto- and alloreactive IgM and alloreactive IgG antibodies. A total of 220 sera was screened at different incubation temperatures, before and after treatment with the reducing agent dithiothreitol, against a large variety of cell targets by means of complement dependent cytotoxicity (CDC) and antiglobulin augmented (AHG) CDC assays. The results allowed to subdivide the HSDP under study into four groups: Group 1 consisted of 13 untransplanted patients and 14 patients with a prior failed graft whose PRA values did not change following DTT treatment. Alloreactive IgG antibodies alone, with anti-HLA specificity, were present in the sera of this patient group. Group 2 consisted of 3 untransplanted patients whose sera did not contain any autolymphocytotoxic antibody but appeared completely unreactive to panel lymphocytes following DTT treatment, thus confirming the presence of alloreactive IgM only endowed with antiHLA reactivity. Group 3 consisted of 4 untransplanted and 4 patients with a prior failed graft whose sera were found to contain in addition to autoreactive IgM also alloreactive IgG antibodies. Their PRA values declined after DTT treatment on average from 96.2% to 45% and from 95% to 52.5%, respectively. Group 4 consisted of 6 untransplanted patients whose PRA reactivity to both autologous and panel lymphocytes completely disappeared following DTT treatment, thus indicating that their sera contained exclusively autolymphocytotoxic IgM antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[A rare thyroid vascular anomaly: a unique thyroid artery arising from the right carotid bifurcation].

The evidence of thyroid vascular anomalies is is frequent and may manifest itself with an anatomic alteration. The absence of the inferior thyroid artery is reported in 1% of the cases, while a thyroid artery arising from the common carotid artery has been found in 2% of examined patients. In the observed case we retain that the rarity is not only due to the contemporary presence of two anomalies, but also to the presence of an anomalous vessel which arises from right carotideal bifurcation and bloody supplies either right lobular or left lobular of thyroid, thus resulting the sole gland's arterial vessel.

Adult↗
PubMed1990

[Pancreatic passenger leukocytes in organs obtained from cadaver donors for allotransplantation].

In previous studies we have demonstrated that human normal pancreata were populated by interstitial mononuclear cells constituted by dendritic cells (70%), macrophages (30%) and few B cells (less than 1%). Furthermore, the endocrine parenchyma and the centroacinar cells appeared negative for the detection of HLA-A,B,C molecules. In the present report, 15 pancreata from cadaver donors were studied by means of immunohistochemical methods. 5 out of 15 organs were found to contain a larger amount of interstitial hematic cells that were constituted mainly by macrophages and B cells, together with a small percentage of granulocytes and T cells. In such "infiltrated" pancreata both endocrine parenchyma and centroacinar cells displayed a positivity for HLA-A,B,C antigens. As HLA-class I antigens have importance in allo-recognition and rejection responses, our data suggest that pre-transplant biopsies may be useful for a better evaluation of the pancreatic tissue immunogenicity.

Cadaver↗
PubMed1989

[The Leu 7+ cell population of the human pancreas: preferential distribution and morphology].

Anti-Leu 7 is a monoclonal antibody which recognizes an antigenic determinant present on the surface of a subset of human large granular lymphocytes and on central and peripheral neural elements. Furthermore it cross-reacts with an intracellular protein of secretory granule matrix in neuroendocrine cells. The presence of Leu 7+ cells has been studied in lymphoid and non-hemopoietic organs. We have analyzed the Leu 7 positivity in six pancreata from cadaver donors by means of immunocytochemical methods. Leu 7+ cells were found to be also present in the exocrine portion of the organ in which they represent a nonhomogeneous cellular population. In fact, two different types of Leu 7+ elements populate the exocrine pancreas: a, Leu 7+ cells showing an intracellular granule positivity; b, Leu 7+ cells showing surface positivity. The endocrine pancreas, in contrast, contains the majority (85%) of Leu 7+ elements, belonging to the intracellular positive type only.

Antibodies, Monoclonal↗
PubMed1989

[Prosthetic salvage operation in patients on hemodialysis].

The use of PTFE, vascular prosthesis (Gore-Tex), in the vascular access for hemodialysis, is a very reliable and exploited method. Thrombosis is the most frequent complication. The prosthetic "salvage operation" allows an immediate functional recovery. The authors examine their series from 1986 on, analyzing the surgical technics employed and the results obtained.

Aged↗
PubMed1989

[Modulation of the expression of histocompatibility antigens class I (HLA-A,B,C) in the human pancreas].

In this study the expression of HLA class I molecules was analysed on caudal portions of ten pancreata from cadaver donors by means of indirect immunoperoxidase and immunophosphatase techniques. In 7 out of ten pancreata the results showed that islets tissue was almost negative for the expression of HLA Class I antigens as opposed to exocrine tissue that appeared positive. Within exocrine tissue and large sized islets strongly positive interstitial cells were also detected. Double stainings showed that the strongly positive interstitial cells expressed also Leu M1 antigens. Preliminary studies on the remaining three pancreata demonstrate an increase of hematic interstitial cells together with a parallel increase of HLA class I antigens by endocrine parenchyma. The above data suggest that an increase of interstitial cells within pancreas may influence islets antigenicity.

Antigens, Differentiation, Myelomonocytic↗