Surface properties and implantation site affect the capsular fibrotic overgrowth.

Transplantation of encapsulated pancreatic islets is a promising approach for the treatment of type 1 diabetes. Large-scale application of this technique, however, is hampered by insufficient biocompatibility of the capsules. In this study, we have evaluated the biocompatibility of a new synthetic material with six different chemical groups on their surface (amino, carboxy-sulfate, carboxylate, hydroxylate, sulfate, and PMMA) used for the fabrication of the microcapsules. Eight Lewis rats were inoculated with a suspension of empty capsules made for each candidate material in the retroperitoneal ileopsoas muscle and renal subcapsular space. Four weeks later kidney and muscle containing the capsules were explanted, paraffin embedded, sectioned and stained with Sirius Red and Masson's Trichrome for histological analysis. The amount of fibrosis was also ultrastructurally evaluated with scanning electron microscopy. The samples were then subjected to digitalized quantitative analysis using specific software to determine the degree of fibrotic overgrowth. The quantification of collagen deposition, calculated in proximity of the microcapsules, was expressed as a percentage of the total area and can be considered a good index for the biocompatibility, an essential prerequisite for functional pancreatic islet transplantation. The results show that subcapsular renal space is the best implantation site and the positive surface charge induces a more intense collagen synthesis.

Does the presence of an iliac aneurysm affect outcome of endoluminal AAA repair? An analysis of 336 cases.

OBJECTIVE: To determine whether the presence of an iliac aneurysm compromises outcome of endovascular exclusion of AAA and to ascertain the fate of the iliac aneurysmal sac. PATIENTS AND METHODS: Between April 1997 and March 2001, data on 336 consecutive patients undergoing endovascular repair for AAA were entered in a prospective database. Suitability for endovascular repair was assessed by preoperative contrast-enhanced computed tomography. A maximum common iliac artery (CIA) diameter > or = 20 mm was defined as iliac aneurysm. Patients with and without iliac aneurysms were compared to early (immediate conversion or perioperative death) and late failure (increase in aneurysm diameter or persisting graft-related endoleak, or late AAA rupture or conversion). RESULTS: Fifty-nine patients (18%) had iliac aneurysms, 19 were bilateral, for a total of 78 aneurysmal iliac arteries (median diameter 23 mm; range 20-50 mm). A distal seal was achieved by landing in 33 external iliac arteries, in 20 ectatic CIAs, and in 25 normal CIAs. Operating time differed significantly between patients with and without CIA aneurysms (153 +/- 71 vs 123 +/- 55 min, p = 0.0001), whereas no statistically significant differences were found with respect to early and late failure (2% vs 3%, p = 0.5 and 14% vs 8%, p = 0.11, respectively). There were no cases of buttock or colon necrosis. At a median follow-up of 14 months (range 0-46; i.q.r. 7-27 months) common iliac diameter decreased > or = 2 mm in 49 cases, remained stable in 25, and increased > or = 2 mm in 3. CONCLUSION: The presence of iliac aneurysm rendered endoluminal AAA repair more complex but did not affect feasibility and long-term outcome of the procedure. In our experience internal iliac exclusion was never associated with significant morbidity. These data may be useful when considering endovascular repair in high-risk patients with challenging anatomy.

Computerised tomography findings as a risk factor in carotid endarterectomy: early and late results.

OBJECTIVES: To evaluate whether preoperative CT evidence of brain infarction is associated with an increased risk of early and late stroke and death in patients undergoing CEA. DESIGN: Retrospective clinical study. MATERIALS AND METHODS: We evaluated 844 CT scanning records from 893 patients undergoing CEA from 1986-1994: 43% (367) CT positive for cerebral infarction and 57% (477) negative. Univariate and multivariate analysis was performed for risk factors and preoperative symptoms in patients with positive and negative CT scans, and Kaplan Meier survival curves for late events. RESULTS: A positive CT was significantly more frequent in males vs. females (p < 0.0001; O.R. 2.52; C.I. 1.73-3.73), diabetics vs. non-diabetics (p = 0.03; O.R. 1.52; C.I. 1.03-2.26), symptomatics vs. asymptomatics (p < 0.001; O.R. 2; C.I. 1.93-3.53) and contralateral occlusion vs. patency (p < 0.001; O.R. 2; C.I. 1.30-3.10). The perioperative disabling stroke/ death rate was higher in patients with a positive CT (p = 0.002; O.R. 6.27; C.I. 1.73-34.20); in asymptomatic patients this difference was striking (5 patients vs. O, p = 0.0002). Multiple logistic regression analysis for risk factors, CT findings, symptoms preceding surgery, and congruity of brain infarction confirmed a significantly higher incidence of perioperative stroke/death rate (p = 0.003; O.R. 6.37; C.I. 5.12-7.63) and early and late stroke (p = 0.02; O.R. 1.95; C.I. 1.38-2.53) and death (p = 0.0005; O.R. 2.38; C.I. 1.89-2.88) in patients with brain lesions. After 7 years, the survival rate (p = 0.0009) and stroke-free interval (p = 0.003) were lower in patients with a positive CT. After 5 years, in asymptomatic patients the survival rate (p = 0.003) and stroke-free interval (p = 0.01) were lower in the positive CT group. CONCLUSIONS: A positive CT finding, regardless of congruity of the lesion, should be regarded as an indicator of an increased risk of stroke and death in patients scheduled for carotid surgery, especially in those with asymptomatic stenosis.

A general-purpose system for long-term recording from a microelectrode array coupled to excitable cells.

A PC-based system for acquisition and processing of data from excitable cells on a microelectrode array is described. Simple and low-cost amplification and filtering custom stages are used. A software package for processing acquired data is proposed.

Cell metabolism measurements in culture via microelectronic biosensors.

Silicon-based H(+)-sensitive biosensors in proximity to a cell population detect variations in cell metabolism via local measurements of changes in pH. The feasibility of this approach is shown in the case of ISFET devices.

Cell metabolism measurements in culture via microelectronic biosensors.

Silicon-based H(+)-sensitive biosensors in proximity to a cell population detect variations in cell metabolism via local measurements of changes in pH. The feasibility of this approach is shown in the case of ISFET devices.

[Prognostic factors in neoplasms of the upper 2/3 of the stomach compared to the lower 1/3. Our experience]. / Fattori di prognosi nelle neoplasie dei 2/3 superiori dello stomaco rispetto a quelle del 1/3 inferiore. Nostra esperienza.

The choice of the type of surgical treatment used in gastric cancer, in cases where it is possible to operate in relation to the extent of cancer, raises the question of whether the surgeon should perform a total exeresis of the organ, even in cases where the tumour is located in the 3rd distal of the stomach. A retrospective study was carried out on patients admitted to the Surgical Department of the University of Perugia between January 1963 and December 1988. Having rejected 123 cases because of incomplete data or insufficient follow-up, 1.140 cases were selected from a total of 1.263 patients. The sites of neoplasia were as follows: terminal esophagus: 1.76% of cases; cardia: 6.67%; fornix of the stomach: 9.37%; the body of the stomach and lesser curvature: 23.65%; body of the stomach (other portions): 10.07%; angulus: 3.63%; gastric antrum: 37.82%, pylorus: 4.45%; the remaining 2.58% showed a diffuse form involving two or more the above parts. The subdivision of the cases into stages, using the TNM classification, revealed the following groupings: 7.04% of patients were first observed at stage I, 20.70% at stage II, 42.04% at stage III and 30.20% at stage IV. From the above figures it is evident that radical surgical was indicated only in some of the patients observed. The prognostic factors examined in the comparative study of different tumour sites were: age, sex, macroscopic and histological tumour type, size, infiltration of neoplasia through gastric wall coat, lymph node and/or systemic diffusion.(ABSTRACT TRUNCATED AT 250 WORDS)

[Our experience with early gastric cancer]. / La nostra esperienza in tema di early gastric cancer.

Gastric cancer has always required surgical therapy since in the majority of cases at the moment of treatment symptoms are already at an advances stage. Over the past years many advances have been made in the early diagnosis of many forms of neoplasia, but the rate of progress has been much slower with regard to gastric cancer. Only the preventive and regular use of gastroscopy will allow the disease to be diagnosed at a non-advanced stage. The term early gastric cancer is used to describe a carcinoma which only infiltrates the mucosa, or the mucosa and submucosa, irrespective of lymph node or other metastases. The present study was based on a retrospective analysis of cases of stomach cancer observed in the Surgical Department of the University of Perugia from January 1963 to December 1988. A total of 1,263 patients were affected by cancer of the stomach during the above period. One hundred and twenty-three cases were not included because of incomplete data or insufficient follow-up. A total of 1,140 patients were therefore included in the study; of these only 99 cases were affected by early gastric cancer. Age, sex, earlier gastric diseases, life styles, familial occurrence of disease, and symptomatology were among the different parameters evaluated. In addition, the site of disease, diagnostic methods, pre- and post-operative staging, intramural diffusion of the disease and surgical treatment were taken into account. In older cases the 5-year survival rate was calculated, whereas in more recent cases statistical methods, based on accumulated data, were used to estimate survival rates.(ABSTRACT TRUNCATED AT 250 WORDS)