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Biomedical subjects

R Bellantone

Publications and source records attributed to R Bellantone.

At least 55 records · Page 3Linked to original sources
PubMed1992

Influence of anterior subdiaphragmatic vagotomy and TPN on rat feeding behavior.

Total parenteral nutrition (TPN) inhibits food intake and feeding behavior. Whether caloric sensory function of the liver contributes to this food intake and feeding behavior regulation via vagal-afferent innervation was tested after performing anterior hepatic vagotomy or sham operation in rats infused with a TPN solution providing 100% of daily energy needs, given continuously for 4 days. Food intake, meal number, size, duration, meal and intermeal sniffs, and eating activity were measured using an automated computerized rat eater meter (ACREM). TPN infusion resulted in a significant decrease of food intake and feeding indexes in both groups. The vagotomized rats showed a significantly higher food consumption, achieved by greater meal frequency, larger meal size, and longer meal duration. Thus, vagotomized rats consumed more than their controls by eating larger meals more often and of longer duration. Data suggest that anterior hepatic vagotomy interrupts hepatic caloric sensory feedback loop, diminishing inhibitory vagal effects on food intake with TPN, leading to an overall increase in food intake.

Afferent Pathways↗
PubMed1992

Hybrid artificial pancreas: islet transplantation inside membrane bioreactors.

The use of pancreatic islet transplantation in membrane bioreactors put in vascular circuits aims at resetting the glucose homeostasis in diabetic or pancreatectomized patients, avoiding immune host rejection. Our experience was carried out at following stages: porcine pancreas explantation and enzymatic separation of endocrine tissue from exocrine fraction by collagenase; evaluation of islet functionality (culture tests); in vitro tests of the islets-bioreactor system, to assess the metabolic response to the glucose; in vivo evaluation to assay the haemodynamic behaviour. The trials showed a good metabolic bioreactor functionality and a decreasing incidence of coagulative problems.

Animals↗
PubMed1992

Endocrine evaluation of patients with benign lumps of the breast.

We studied 39 women with benign breast disease in order to evaluate their endocrine status. Two groups of women were distinguished: premenopausal (n = 22) and postmenopausal (n = 17). We determined basal concentrations of the following: follicle-stimulating (FSH) hormones, luteinizing hormone (LH), prolactin (PRL), estrone (E1), estradiol (E2), testosterone (T), androstenedione (A), dehydroepiandrosterone sulfate (DHEAS). We also assayed sex hormone-binding globulin (SHBG) and calculated the free androgen index (FAI). The samples in premenopausal subjects were collected in the follicular phase. There was no significant difference between the groups considered and normal control subjects for any of the hormones tested; there was no significant correlation between T concentration or E2/T ratios and SHBG levels; the FAI was not significantly different compared to normal subjects. In conclusion, even if basal steroid, gonadotropin, and SHBG levels do not indicate an unequivocal alteration, it is not possible to exclude subtle alterations in transport and local metabolism of steroids. The balance between steroids and SHBG seems to indicate small dysregulations, which could be of some importance.

Adult↗
PubMed1992

Membrane bioreactors as hybrid artificial pancreas: experimental evaluation.

Results of cultured islet transplantation in the management of insulin-dependent diabetes are still unsatisfactory. The main problem preventing success is the swift and resolute host immune rejection. To obviate this we designed and experimented a model of bioartificial pancreas, made of polymeric hollow fibers, put into the blood circulation as an artero-venous bypass to immunoisolate endocrine tissue from leucocytes and immunoglobulins. We tested four different membrane bioreactors (BR1-4). BR1 and 2 had seven hollow fibers, the others more than 6,000 smaller fibers. In BR4 a connecting tube with a high-permeability membrane was inserted between the islet compartment and the bioreactor outlet to improve the ultrafiltration flow. In vitro, the islets inside the bioreactor perfused with glucose solutions (300 mg%) showed a rapid, high insulin secretory response, related to the glucose stimulation. The use of the outside connection allowed a twofold increase of insulin production.

Animals↗
PubMed1991

Receptors for epidermal growth factor and steroid hormones in primary colorectal tumors.

The presence of epidermal growth factor, estrogen, and progesterone receptors (EGFR, ER, and PR) was investigated by a competitive binding assay in 43 colorectal adenocarcinomas and 32 normal colorectal mucosa specimens. EGFR were expressed in most of the tumor specimens analyzed at levels comparable with normal mucosa. There was no correlation between EGFR and tumor localization, tumor size, tumor stage, and grading. Among tumor specimens, 13.9% and 6.9% expressed very low but detectable ER and PR levels, respectively. No statistically significant difference was found between steroid hormone receptor levels in the tumor and normal mucosa specimens, and neither was there any correlation of ER and PR with the pathological findings. Our results suggest that the EGFR system may play a role in regulating the growth of colorectal tissues. Further studies should demonstrate whether, despite the lack of correlation with histopathological parameters, EGFR expression may have a biological significance in human colorectal cancer.

Adenocarcinoma↗
PubMed1991

Prognostic factors in colorectal cancer: current status and new trends.

The clinical, laboratory, and pathologic data of 361 patients who had curative resections for colorectal cancers were collected and analyzed in a multiple stepwise regression model. In univariate analysis, among clinical factors, bowel obstruction and emergency surgery showed the most significant prognostic value (P = 0.002, P = 0.004, respectively). Vegetating growth, Astler-Coller stage of tumor, intramural spread, lymph node involvement, and synchronous liver metastases resulted in the pathologic variable significantly affecting the prognosis (P = 0.006, P less than 0.001, P = 0.036, P less than 0.001, P less than 0.001, respectively). In the multivariate analysis, stage was the predictive factor with the highest hazard ratio in conjunction with bowel obstruction (P less than 0.0001 in both cases). Processing data excluding stage ("multiparametric factor" itself), hepatic metastases, lymph node involvement, bowel obstruction, and intramural spread appeared as independent predictors of survival (P less than 0.0001, P less than 0.0001, P = 0.0004, P = 0.0316, respectively). Other variables, as biologic and molecular factors, should be more widely tested in order to assess their impact on prognosis.

Actuarial Analysis↗
PubMed1991

Change in meal size, number and duration after neural isolation of liver and with TPN.

The abundant neural connections between the liver and hypothalamus suggest that the liver contributes to spontaneous food intake (SFI) regulation. This hypothesis was tested in rats after total liver denervation (TLD) and infusing TPN. A sham operation (SO) or TLD was performed in Fischer rats, placed in metabolic cages fitted with an Eater Meter to measure SFI, meal number (MN), size (MZ), and duration (MD). Rats had free access to chow and water. After 22 days, a jugular catheter was placed and normal saline continuously infused for 10 days (days 22-32). Then TPN-100, providing 100% of rats daily energy needs, was infused for 3 days (days 32-35). During the post-SO/TLD and postjugular catheterization periods and during TPN-100, SFI was the same in SO controls and TLD group. However, TLD rats had decreased MZ and MD (interpreted as early satiety) and increased MN (interpreted as increased hunger) to maintain the same SFI as control rats. Although total SFI was not influenced by TLD, it significantly affected feeding pattern, suggesting that the neural isolation of the liver from the brain produces altered hypothalamic regulation of not only the onset of feeding, but also satiety.

Animals↗
PubMed1991

Cathepsin D and epidermal growth factor in human breast cyst fluid.

Cathespin D (Cath D) is a proteolytic enzyme secreted by human breast cancer cells with a growth promoting activity in vitro. In the present study, we measured Cath D and Epidermal Growth Factor/alpha Transforming Growth Factor (EGF/alpha-TGF) concentrations in the breast cyst fluid (BCF) of 43 patients with gross cystic disease of the breast. Both Cath D (median 2.45 pmoles mg-1 protein; range 0-4.84 vs 0.98 pmoles mg-1 protein; range 0-3.11) and EGF/alpha-TGF (28.71 ng mg-1 protein; range 7.05-50.63 vs 10.83 ng mg-1 protein; range 0.06-30.55) levels were higher in BCF of apocrine than flattened cysts (P less than 0.0005 and P less than 0.01, respectively). Premenopausal patients showed higher concentrations of Cath D (P less than 0.05) and EGF/alpha-TGF (P less than 0.05) than postmenopausal patients. A positive correlation was obtained between intracystic concentrations of Cath D and EGF/alpha-TGF (P less than 0.00001). The higher levels of Cath-D and EGF/alpha-TGF found in apocrine cysts could provide an explanation for the increased risk of subsequent breast cancer in women with this type of cyst.

Adult↗
PubMed1991

Single dose imipenem-cilastatin compared with three doses of cefuroxime and metronidazole as prophylaxis in elective colorectal surgery: a prospective randomized study.

A prospective randomized study was performed with 61 patients undergoing elective surgery for colorectal cancer, to evaluate the prophylactic effect of two different parenteral antibiotic regimens. All patients were randomly allocated into two groups, comparable in age, sex, nutritional status and operative procedures. The patients in Group A (n. 31) received 1 g i.v. of imipenem-cilastatin at induction of anesthesia. Patients in Group B (n. 30) were given cefuroxime (1.5 g i.v.) plus metronidazole (0.5 g i.v.) at the time of anesthesia and two other administrations of the combined antibiotics (cefuroxime 0.75 g plus metronidazole 0.5 g i.v.) every 8 hours. The severity of sepsis was evaluated according to the scoring system proposed by Elebute and Stoner. No significant differences were found in terms of the rate of surgical infections: 9% in Group A and 16% in Group B. Infections not of surgical origin were found only in Group B (10.4%). These data suggest that a single dose of intravenous imipenem-cilastatin appears to be as effective as three doses of cefuroxime and metronidazole as prophylaxis against infection in elective colorectal surgery.

Adult↗
PubMed1991

Endocrine status in patients with mammary gland diseases: correlation between steroid hormones and sex steroid binding globulin.

We have studied 131 women affected by benign or malignant breast disease, in order to explore their endocrine status. We evaluated basal concentrations of the following hormones: FSH, LH, PRL, estrone (E1), estradiol (E2), testosterone (T), androstenedione (A), DHEAS and SHBG. Basal hormone levels in these patients were not significantly different from those in normal age-matched subjects. However, in premenopausal women, 31% of patients with benign disease and 34.4% with malignant lumps exhibited an elevated FSH/LH ratio (greater than 1) and lower T levels, compared to those having a normal FSH/LH ratio. The difference in T levels was not coupled with the expected specular variations in SHBG levels. Moreover, in none of the group considered, T concentrations or E2/T were significantly correlated with SHBG levels. These data seem to suggest an altered regulation of SHBG in these patients, in whom the modulation of SHBG by circulating sexual steroids appears to be different when compared with normal subjects.

Adult↗
PubMed1991

[Controversies about reconstruction after pancreatic resections in neoplasms of the periampullary area].

Extended pancreatic resections have still a significative morbidity: this explains all the technical alternatives proposed to the Whipple procedure. Treatment of the pancreatic stump after cephalic resection and the need of gastric resection are particularly debated today. The Authors, together with a wide literature review, report their experience with 45 patients who underwent cephalic (28 cases), subtotal (4 cases) or total (13 cases) pancreatectomy. Telescope pancreaticojejunostomy showed overall satisfying results (7% of dehiscences), inducing the Authors to use it in all cases. The role of pyloric preservation as proposed by Traverso and Longmire, which strongly reduces nutritional sequelae of pancreatectomy without negative effects on oncological radicality, is emphasized.

Duodenum↗
PubMed1991

Risk factors in relation to postoperative complications and mortality after total gastrectomy in aged patients.

To clarify the risk factors contributing to postoperative complications in elderly patients undergoing total gastrectomy, 84 patients with primary gastric cancer were evaluated. Twenty-seven patients were older than 65 years of age; they had much more preoperative cardiac (P = 0.00003), respiratory (P = 0.0008), and multiorgan impairment (P = 0.009) than did the control group (age less than 65 yrs). Although overall morbidities (44.4% vs. 19.2%; P = 0.01) and overall septic complication rates (33.3% vs. 12.2%; P = 0.02) were higher in aged patients, no significant differences between the two groups were found in the incidence of major surgical complications (18.5% in aged patients vs. 10.5% in control groups; P = NS), serious septic (sepsis score greater than 10) complications (18.5% vs. 7.0%; P = NS) and hospital mortalities (11.1% vs. 3.5%; P = NS). In older patients the occurrence of multiorgan impairment and malnutrition was significantly related to postoperative complication rates. These results suggest that the degree of organ impairment rather than age is predictive of postoperative difficulty and should be used in assessing preoperative risk.

Adult↗
PubMed1990

Diagnostic delay in breast cancer: correlation with disease stage and prognosis.

Diagnostic delay in a group of 189 women with breast cancer was studied and correlated with first symptom, stage of disease, histologic grade and prognosis. Diagnostic delay was divided into patient delay (time from the patient's discovery of a symptom to the first medical consultation) and system delay (time from medical diagnosis to treatment). Patients were divided into five groups by patient-delay time: 0 to 30 days; 31 to 90 days; 91 to 180 days; 181 to 365 days; and greater than 365 days. The median diagnostic delay was 60 days (range, 4-980) and was not influenced by patient age, marital status or nature of first symptom. A consistent and direct relationship was found between delay and tumor size, nodal involvement, presence of metastases, and histologic grade of disease at diagnosis. No correlation was found between diagnostic delay and histologic type distribution. The three-year survival rate after treatment was significantly lower for patients with a longer delay. Our data indicate that diagnostic delay appears to be an important determinant of stage at diagnosis in women with breast cancer and that it has an important influence on survival. In most cases, delay was mainly patient dependent (60 days); the median system-dependent delay was 15 days (range, 4-47). Since early treatment is generally accepted to be one of the most important determinants of prognosis in breast cancer patients, a reduction in diagnostic delay may lengthen survival time.

Adult↗
PubMed1990

Rat liver tolerance for partial resection and intraoperative radiation therapy: regeneration is radiation dose dependent.

We studied the feasibility of delivering a large single dose of intraoperative radiation as an adjuvant to partial hepatic resection. Intraoperative radiation therapy (IORT) was delivered to the remaining liver of 84 rats after partial hepatectomy to determine the acute and chronic effects of treatment on blood chemistry values, histology, survival, hepatic regeneration, and cellular appearance of the normal liver. Transient elevations in SGOT, SGPT, and alkaline phosphatase were attributed both to hepatectomy and to liver parenchymal damage induced by IORT. Microscopic examination upon necropsy, performed at frequent intervals post-treatment revealed hepatic capsular thickening with some alteration of liver architecture mainly underneath the capsule, with localized inflammation and some areas of necrosis. Survival in all groups was 100% at 45 days. Liver weight increase proved to be dose-dependent and displayed a bisphasic pattern. This study demonstrated that IORT is a feasible adjunct to surgical resection of the liver in the rat model.

Alanine Transaminase↗
PubMed1990

Short-term antibiotic prophylaxis in open urologic surgery.

The aim of the present study was to compare the efficacy of a single dose of ceftriaxone with a triple dose of gentamicin as prophylactic agents in patients undergoing open urologic surgery. Fifty-two patients were allocated into two groups which were well matched with respect to sex, age and surgical procedure: --24 were given single-dose ceftriaxone (2 g i.v.) at the time of anesthesia (ceftriaxone group); --28 received gentamicin (80 mg i.v.) at the time of anesthesia and two additional doses of the same antibiotic were subsequently administrated every 8 hours (gentamicin group). The incidence of urinary tract infection (UTI) was 3.5% in the gentamicin group and 0% in the ceftriaxone group (p = n.s.); postoperative fever (greater than 38 degrees C) occurred in 28.3% and 8.3% in the gentamicin and ceftriaxone groups respectively (p = n.s.). There was no clinical or hematological evidence of drug side effects in any patient. Results of the study show that short-term antibiotic regimens can improve UTI rates after open urologic surgery; moreover a single preoperative dose of ceftriaxone resulted to be as effective as three doses of gentamicin.

Ceftriaxone↗