Search PubMed⌕ Search

Biomedical subjects

F Pardo

Publications and source records attributed to F Pardo.

At least 73 records · Page 4Linked to original sources
PubMed1995

Forearm muscle insulin resistance during hypoglycemia: role of adrenergic mechanisms and hypoglycemia per se.

The forearm perfusion technique was used 1) to quantify the muscle metabolism of glucose and gluconeogenic precursors in response to insulin-induced hypoglycemia and 2) to assess the role of catecholamines and glucose concentration, pe se. Insulin (0.5 mU.kg-1.min-1) was infused for 4 h in three groups of healthy volunteers. In group I (n = 6), blood glucose (BG) was maintained at its basal level (4.5 +/- 0.1 mmol/l). In group II (n = 7), BG was allowed to fall to approximately 3 mmol/l. Group III (n = 6) was similar to group II except that propranolol was infused also. In addition, at 240 min, hypoglycemia was locally corrected by intrabrachial glucose infusion while maintaining the systemic milieu unperturbed. In group I, forearm glucose uptake (FGU) increased from 4.7 +/- 1.3 to a mean value of 37.8 +/- 5.0 mumol.l-1.min-1, whereas in group II it remained unchanged (8.3 +/- 2.0 mumol.l-1.min-1). In group III, propranolol partially prevented the suppression of FGU that increased to 21.6 +/- 5.2 mumol.l-1.min-1 (P < 0.05 vs. group II). Local correction of hypoglycemia normalized the FGU response (36.5 +/- 8.0 mumol.l-1.min-1). Muscle release of lactate, but not of alanine, was slightly higher during hypoglycemia (P = not significant). Forearm blood flow remained unchanged in groups I and III, whereas it increased by approximately 40% in group II (P < 0.05). It is concluded that, during mild hypoglycemia 1) extreme insulin resistance develops in the skeletal muscle, mediated by beta-adrenergic stimulation and reduced glucose mass effect and 2) mobilization of gluconeogenic precursors is only weakly activated.

Adult↗
PubMed1995

[Somatostatin prophylaxis following cephalic duodenopancreatectomy].

This study was aimed at assessing the value of prophylactic somatostatin after cephalic duodenopancreatectomy. A randomized prospective study was undertaken using two groups of patients, one with prophylactic somatostatin (4.5 mg daily in continuous perfusion for 7 days postoperatively), known as group I, and group II, which did not receive somatostatin. During a five-year period, from April 1989 to April 1994, we performed 35 duodenopancreatectomies, of which 21 belonged to group I and 14 to group II. We found a lower incidence of pancreatic anastomosis fistulae in group I (9.5% vs 35.7%; p < 0.05). We did not find any correlation between prophylaxis with somatostatin and the appearance of other complications or postoperative mortality. The mean time of fistula closure in group I was 5 days while that of group II was 19.2 days. In conclusion, the administration of prophylactic somatostatin after cephalic duodenopancreatectomy reduces the incidence and duration of pancreatic fistula.

Adult↗
PubMed1994

Role of insulin and free fatty acid (FFA) availability on regional FFA kinetics in the human forearm.

To determine the role of insulin and free fatty acid (FFA) concentration in the regulation of FFA metabolism, forearm FFA fluxes were quantified in 16 healthy volunteers by combining the forearm perfusion technique with the infusion of [3H]palmitate. Three groups of studies were performed. In study 1 (n = 6), a systemic insulin infusion (1.2 mU/kg.min) was performed for 120 min while euglycemia was maintained by a variable glucose infusion. In Study 2 (n = 5), insulin (0.05 mU/kg.min) was infused into the brachial artery to expose the forearm tissues to the same insulin level as in study 1. In study 3 (n = 5), heparin was infused to raise plasma FFA concentration to 1-1.5 mmol/L. At 60 min, an intrabrachial insulin infusion was added as in study 2 and maintained for 60 min. During systemic insulin infusion, plasma FFA concentration fell to 0.09 +/- 0.02 mmol/L. Forearm FFA uptake (FFA-U) decreased from the basal value of 2.54 +/- 0.52 to 0.95 +/- 0.10 mumol/L.min (P < 0.05). Likewise, forearm FFA release (FFA-R) fell to 1.0 +/- 0.31 mumol/L.min (P < 0.05). With local insulin administration, both FFA levels and FFA-U remained unchanged, whereas FFA-R was markedly inhibited (from 1.78 +/- 0.23 to 1.04 +/- 0.24 mumol/L.min; P < 0.05). In study 3 (heparin infusion), FFA levels rose to 1.17 +/- 0.12 mmol/L due to a 4-fold increase in FFA-R (from 1.18 +/- 0.36 to 6.92 +/- 2.40 mumol/L.min; P < 0.05). FFA-U rose from the basal value of 2.50 +/- 0.82 to 6.92 +/- 1.95 mumol/L.min (P < 0.05). Addition of intrabrachial insulin did not modify FFA-U, whereas heparin activation of FFA-R was only partially antagonized (4.53 +/- 2.40 mumol/L.min; 0.01 < P < 0.05 vs. heparin alone). The data demonstrate that plasma FFA concentration is the main determinant of forearm FFA transport. Insulin exerts a direct inhibitory effect on FFA release and affects tissue FFA transport only indirectly through the fall in circulating FFA.

Adult↗
PubMed1994

[Role of extended type R2 lymphadenectomy in the surgical treatment of resectable gastric cancer].

The extended lymphadenectomy has been proposed as routine procedure in the surgical treatment of gastric cancer, although some controversies have been published. We present a retrospective analysis on the impact of extended lymph node dissection after total gastrectomy, in terms of post-operative course and histopathologic findings, in a group of 30 patients with R2 lymphadenectomy and in 16 patients with R1 lymphadenectomy. There were no significant differences in duration of operation, amount of blood transfusion and length of hospital stay between the 2 groups. The only significant difference was found in the greater amount of drainage output after R2 lymphadenectomy as compared with R1. There were no mortalities in either group and morbidity rate was similar for both [43% in R1 and 40% in R2) mostly in the form of abdominal infections (18% in R1 and 16% in R2]). A significantly greater number of lymph nodes was identified after R2 gastrectomy. Fifty-three per cent of patients has positive lymph nodes, 12% of them being from the N2 echelon of nodes (including one case of early gastric cancer). Careful lymph node dissection in gastric cancer surgery allows a more precise staging of the tumor with no increase in postoperative morbidity.

Adult↗
PubMed1993

Intraoperative radiotherapy in locally advanced recurrent colorectal cancer.

PURPOSE: In an effort to promote local control and improve quality of life in patients with recurrent colorectal cancer, a multimodality approach has been used. METHODS AND MATERIALS: Twenty-seven patients were treated with moderate doses of pre/postoperative radiotherapy with/without simultaneous systemic chemotherapy, surgical re-resection and IORT electron boost over areas at high risk for local recurrence. RESULTS: The 2-year actuarial disease-free and local relapse-free survival for the entire group were 14% and 26%, respectively. The most important factor predicting a favorable outcome was the radicality of surgical procedure. The determinate local control rate and the actuarial 2-year local relapse-free, and disease-free survival for patients undergoing complete resections were 50%, 56%, and 34%, respectively, whereas for patients undergoing partial resections these figures were 16%, 13%, and 6%. The radicality of surgical procedure was influenced by both tumoral size and previous treatment with irradiation. Complete resection rate was higher in patients with tumors less than 5 cm vs. more than 5 cm (40% vs. 22%), and in patients without previous radiotherapy versus those with previous radiotherapy (40% vs. 28%). Distant metastasis rate was high (41%). The most significant toxicities attributable to the whole treatment protocol were enteritis (37%), hydronephrosis (30%), and pelvic neuropathy (52%). CONCLUSION: Currently, our policy is to recommend IORT in patients with "favorable factors" such as: absence of previous pelvic radiotherapy, single previous surgical procedure, and complete resections.

Adult↗
PubMed1993

Intrinsic radiation sensitivity may not be the major determinant of the poor clinical outcome of glioblastoma multiforme.

PURPOSE: Many radiobiologic mechanisms may contribute to the clinical radiation resistance of Glioblastoma Multiforme. One of them is considered to be an unusually low intrinsic radiation sensitivity. This is a collaborative study between three laboratories to evaluate the intrinsic radiation sensitivity of 85 cell lines derived from human malignant gliomas as the major cause of the poor clinical results of radiation treatment to these tumors. METHODS AND MATERIALS: Fifty-one cell lines were early passage. The distribution by histologic type was: 58 glioblastoma, 17 anaplastic astrocytoma, six oligodendroglioma and four astrocytoma grade 2. The intrinsic radiation sensitivity will be expressed by the surviving fraction at 2 Gy (SF2). The SF2 has been determined for single dose irradiation for cell lines on exponential phase, under aerobic conditions, growing on plastic. The patient age, Karnofski Status, histological grade, survival, dose of irradiation for 50 patients are investigated for correlation with SF2 of the corresponding newly established cell lines. RESULTS: The mean SF2 of the 85 cell lines was 0.46 (0.12-0.87). The mean SF2 by histologic type was 0.50, 0.34, 0.54 and 0.38 for glioblastoma, anaplastic astrocytoma, oligodendroglioma and astrocytoma grade 2 cell lines, respectively. No correlation was found between SF2 and the patient age or Karnofski status. The difference in SF2 between the 58 glioblastoma and 17 anaplastic astrocytoma cell lines was significant p = 0.002. The difference in actuarial survival between glioblastoma and anaplastic astrocytoma patients was borderline of significance (p = 0.08). The difference in SF2 of cell lines derived from these two groups of patients was of borderline significance (p = 0.08). The difference in radiation sensitivity for anaplastic astrocytoma and glioblastoma cell lines was clearly reflected in the difference in survival for the two groups of patients from where the cell lines were derived. However, no correlation was found between SF2 and survival within each grade. In a multivariate analysis the age, grade and Karnofski status were found to be significant prognostic values for survival with a p values of 0.032, 0.03 and 0.038, respectively, however, the ln SF2 was not significant (p = 0.40). The mean SF2 of the 6 oligodendroglioma cell lines (0.54) was comparable to that of glioblastoma multiforme (0.50). The high SF2 for oligodendroglioma does not accord with the much better clinical outcome of these tumors. CONCLUSIONS: These data on 85 malignant glioma cell lines show a very broad distribution of SF2 values for irradiation in vitro. SF2 reflected the difference in sensitivity between AA (Grade 3) and GBM (Grade 4). This may suggest that the parameter SF2 is useful to discriminate between the sensitivity of different grades or types of histology in vitro. However, SF2 was not a predictor of the clinical outcome on individual basis for malignant gliomas. The in vitro studies will need to be supplemented by physiologic characterization of the tumors in vivo. Such conclusions would limit the predictive value of current radiation sensitivity assays based on in vitro dose-survival measurement for at least high grade malignant gliomas.

Astrocytoma↗
PubMed1993

Giant jejunoileal duplication: prenatal diagnosis and complete excision without intestinal resection.

A 7-week-old child presented to the pediatrician after persistent vomiting and abdominal distension developed. Intestinal dilatation had been detected in utero. Emergency ultrasonography showed only small bowel dilatation. There were no signs of intestinal obstruction; however, complete intestinal malrotation was demonstrated by an upper gastrointestinal series and barium enema. Intestinal duplication was also suspected, and emergency laparotomy was performed. A 70-cm-long jejunoileal duplication was found and successfully dissected free from the normal small bowel and excised without intestinal resection-anastomosis. The authors describe this unique case and the surgical technique for the treatment of small bowel duplications.

Cysts↗