Biomedical subjects

E Aranda

Publications and source records attributed to E Aranda.

At least 37 records · Page 2Linked to original sources

PubMed2001

Effect of angiotensin-converting enzyme inhibition on renal filtration surface area in hypertensive rats.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitor treatment leads to protective effects on the cellular structure of the glomerulus and the kidney. The aim of this study was to determine whether ACE inhibition increases renal filtration surface area in the spontaneously hypertensive rat (SHR). METHODS: SHR were treated with the ACE inhibitor perindopril at a high dose (3 mg/kg/day) or a low dose (0.1 mg/kg/day) during the period of hypertension development, from 7 to 14 weeks of age. Some animals were treated concomitantly with the bradykinin B2 receptor antagonist, S16118. Tail-cuff systolic blood pressure and body weights were measured twice weekly. At termination of treatment, glomerular number and volume, length, and surface area of glomerular capillaries and renal filtration surface area were estimated using unbiased stereological techniques. RESULTS: There were significant dose-related reductions in blood pressure with high- and low-dose perindopril treatment. Neither low- nor high-dose perindopril treatment had any effect on glomerular number or size or glomerular capillary length and surface area. Hence, there was no significant difference in total renal filtration surface area between any of the experimental groups (8721 +/- 610 mm2 in untreated SHR and 7879 +/- 338 mm2 and 8767 +/- 437 mm2 in the low and high dose perindopril-treated groups, respectively). Coadministration of the bradykinin antagonist did not affect any of the glomerular parameters. CONCLUSIONS: ACE inhibition during the period of hypertension development does not lead to an enhanced glomerular capillary growth or increases in total renal filtration surface area in this model.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed2001

Tegafur and uracil plus leucovorin in advanced colorectal cancer: a phase II trial.

The objective of this study was to evaluate the activity and toxicity of tegafur and uracil (UFT; 1:4 molar ratio) plus leucovorin (LV) in patients with advanced colorectal cancer. One hundred forty-one patients were entered into the study. The treatment schedule consisted of UFT 300 mg/m2/day (in three divided doses) plus oral LV 150 mg/day (50 mg t.i.d.) over 28 days. The treatment cycle was repeated every 5 weeks until progression or unacceptable toxicity was observed. The treatment was interrupted if grade 3/4 toxicity appeared and was resumed at the same dosage on recovery. One hundred thirty-six patients were evaluable for response and 141 were evaluable for toxicity. The response rate was 19.9% (95% confidence interval: 12%-28%). The total number of patients without progression (objective response + stable disease) was 76 (55.9%). The median time to progression was 5.6 months, and the overall survival was 11.6 months. The toxicity profile was low, with 11% of patients experiencing grade 3/4 nausea and vomiting, while 17% had grade 3/4 diarrhea. Oral administration of UFT modulated with LV is a comfortable regimen of chemotherapy for patients with advanced colorectal cancer.

Administration, Oral↗

PubMed2000

Cardiovascular risk factors in vegetarians. Normalization of hyperhomocysteinemia with vitamin B(12) and reduction of platelet aggregation with n-3 fatty acids.

Hyperhomocysteinemia in association with vitamin B(12) deficiency, and increased platelet aggregation, probably due to dietary lack of n-3 fatty acids, constitute cardiovascular risk factors frequently observed in vegetarians. We tested if administration of vitamin B(12) normalizes the concentration of total plasma homocysteine, and if intake of eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) fatty acids modulates platelet function in a population of lactoovovegetarians. One week after a single intramuscular injection of cyanocobalamin (10000 microg) in 18 individuals, serum vitamin B(12) increased from 149+/-63 pg/mL to 532+/-204 pg/mL (p<0.0001) and total tHcy dropped from 12.4+/-4.7 to 7.9+/-3.1 micromol/L (p<0. 0001). Ten of fourteen of these vegetarians completed an 8-week supplementation with 700 mg/day of each eicosapentaenoic and docosahexaenoic acids. Increased incorporation of these fatty acids into plasma lipids was observed in all of them, together with a significant reduction in maximum percentage or slope of platelet aggregation with all the agonists tested (ADP, epinephrin, collagen, arachidonic acid). No significant change in bleeding time was observed after n-3 fatty acid trial. Supplementation with vitamin B(12) and n-3 fatty acids corrects hyperhomocysteinemia and reduces platelet reactivity to agonists in vegetarians. Whether this supplementation improves the already reduced cardiovascular morbidity and mortality associated with vegetarian diet has yet to be demonstrated.

Adult↗

PubMed2000

Growth inhibitory effects on fall armyworm Spodoptera frugiperda of some limonoids isolated from Cedrela spp. (Meliaceae).

Dichloromethane extracts of Cedrela salvadorensis and Cedrela dugessi afforded a photogedunin epimeric mixture, gedunin and cedrelanolide. These compounds and the photogedunin epimeric acetates 3 and 4 at the 23-OH position were evaluated against Spodoptera frugiperda. Toosendanin, isolated from Melia azedarach, was used as a positive control. When tested for activity on neonate larvae into the no-choice bioassays, gedunin, photogedunin epimeric mixture, and photogedunin acetates mixture caused significant larval mortality with LC(50) of 39.0, 10.0, and 8.0 ppm at 7 days, respectively, as well as growth reduction. All the compounds tested inhibited larval growth, compared to the control, in a concentration-dependent manner. In addition, it was possible to observe significant reduced pupal weights and adult emergence. All the tested compounds except cedrelanolide showed comparable activity to that of toosendanin.

Animals↗

PubMed2000

Rapid differentiation of Staphylococcus aureus from staphylococcal species by arbitrarily primed-polymerase chain reaction.

An arbitrarily primed-polymerase chain reaction (AP-PCR) method was optimized to differentiate Staphylococcus aureus from other staphylococcal species, using DNA from crude cell extract. From the different assays carried out, the best resolution of the band patterns was obtained when the reaction mixture contained 200 micromol l(-1) dNTPs, 200 ng primer, 1 U Taq DNA polymerase and 3 mmol l(-1) MgCl2 and the amplification conditions were: initial denaturation of 94 degrees C for 1 min, primer annealing of 30 degrees C for 1.5 min, DNA extension at 55 degrees C for 5 min and final extension at 55 degrees C for 5 min. The results of the characterization of the staphylococcal isolates by AP-PCR are in accordance with those of the biochemical identification by the API Staph System, time of analysis of the AP-PCR being only 6-7 h. Thus, this technique could be a useful method for microbial quality assurance.

Bacterial Typing Techniques↗

PubMed2000

Effects of substrate, water activity, and temperature on growth and verrucosidin production by Penicillium polonicum isolated from dry-cured ham.

Penicillium polonicum, a common mold on dry-cured meat products, is able to produce verrucosidin, a potent neurotoxin. The ability of P. polonicum isolated from dry-cured ham to grow and produce verrucosidin from 4 to 40 degrees C at water activities (a(w)) of 0.99, 0.97, and 0.95 on malt extract agar (MEA) and a medium made up with meat extract, peptone, and agar (MPA) was evaluated. Verrucosidin was quantified by high-pressure liquid chromatography and mass spectrometry. P. polonicum was able to grow on MEA and MPA at all the a(w) values tested from 4 to 37 degrees C but not at 40 degrees C. The optimal environmental conditions for growth were 20 degrees C, 0.99 a(w) on MEA and 20 to 25 degrees C, 0.97 a(w) on MPA, but the highest amount of verrucosidin was obtained at 25 degrees C, 0.99 a(w) in both media. No direct correlation between extension of mold growth and verrucosidin production was found. Temperature appears to be the most important factor ruling mycelial growth, whereas verrucosidin accumulation is mostly influenced by a(w). However, analysis of variance of the data showed that there was a complex interaction among all the environmental factors (medium, temperature, and a(w)) that significantly (P < 0.0001) affected growth and verrucosidin production. The reduction of a(w) to intermediates values of 0.95 has a stronger effect on growth on MEA than on MPA. Given that the meat-based medium proved to be an appropriate substrate for the biosynthesis of verrucosidin by P. polonicum, the ability of this mold to produce the toxin on meat products should be established.

Animals↗

PubMed1999

Biological activities of crude plant extracts from Vitex trifolia L. (Verbenaceae).

Biological assays of Vitex trifolia L. organic extracts have shown relevant activities. Hexanic and dichloromethanic (DCM) extracts, when prepared from stems and foliage, have proved to be very toxic against several cancer cell lines in culture (SQC-1 UISO, OVCAR-5, HCT-15 COLADCAR, and KB). Also, an important antifeeding activity against the insect pest Spodoptera frugiperda (Lepidoptera: Noctuidae) was recorded. The hexanic extract from leaves completely inhibited the growth of the fungal plant pathogen Fusarium sp. within the first 2 days of the experiment, but dropped significantly at day 6 (15% inhibition). The potential of V. trifolia for several uses is discussed.

Animals↗

PubMed1999

Vegetarians and cardiovascular risk factors: hemostasis, inflammatory markers and plasma homocysteine.

We studied hemostatic and inflammatory cardiovascular risk factors (CVRF), and total plasma homocysteine (tHcy) in 26 vegetarians (23 lacto- or ovolactovegetarians and 3 vegans), matched by age, sex and socioeconomic status with omnivorous controls. Vegetarians had significantly lower proportion of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids in plasma lipids, significantly shortened bleeding time, and increased blood platelet count and in vitro platelet function (aggregation and secretion). Plasma levels of all coagulation or fibrinolytic factors and natural inhibitors synthesized in the liver were lower in vegetarians than in controls. Whereas for some factors this decrease was statistically significant (fibrinogen, factor VIIc, antithrombin III, protein S, plasminogen) for the remaining (factors VIIIc, Vc, prothrombin, protein C) a trend in the same direction was found. For hemostatic proteins of predominantly extrahepatic origin (von Willebrand factor. tPA, PAI-1) this tendency was not present. No significant differences in inflammatory proteins (C-reactive protein and alpha1-protease inhibitor) were detected in both groups. tHcy was significantly increased in vegetarians, and correlated only with cobalamin levels. The increased platelet function and tHcy found in vegetarians may counteract the known cardiovascular health benefits of vegetarian diet (VD).

Adult↗

PubMed1999

UFT plus or minus calcium folinate for metastatic colorectal cancer in older patients.

Two studies were carried out to determine the activity and evaluate the toxicity of oral chemotherapy with uracil and tegafur in a 4:1 molar ratio (UFT) plus or minus calcium folinate in elderly patients with advanced colorectal cancer. In one study, 106 patients received a fixed dose of UFT 400 mg/day in two daily doses every 12 hours continuously, plus calcium folinate 45 mg/day administered in three divided doses every 8 hours continuously. In study 2, calcium folinate was omitted, and the dose of UFT was increased to 400 mg/m2/day in two daily doses administered every 12 hours continuously to 95 patients. Treatments for both studies were administered until grade 3 or grade 4 toxicity occurred or disease progressed. The response rate among the 96 available patients in study 1 was 17.7% (95% confidence interval [CI], 10% to 27%); 41 patients (43%) achieved an objective response or stable disease. Overall survival was 13.7 months with a statistically significant difference between patients with no progressive disease and patients with progressive disease (P < .01). In study 2, 62 of 95 patients have now been evaluated for response. The response rate was 21% (95% CI, 13% to 30%); 38 patients (61%) experienced an objective response or stable disease. The overall survival for study 2 has not yet been evaluated. Toxicity was generally mild, consisting of grade 3 nausea/vomiting (6% in study 1 and 2% in study 2), grade 3 or grade 4 diarrhea (11% in study 1 and 7% in study 2), plus one case of grade 3 mucositis in study 1. These findings suggest that chemotherapy with UFT (with or without modulation with calcium folinate) is feasible for elderly patients with advanced colorectal carcinoma.

Adenocarcinoma↗

PubMed1999

[Effect of an algae extract and several plant growth regulators on the nutritional value of potato (Solanum tuberosum L. var. gigant)].

Four commercial plant-growth (Biofol, Biozyme, Cytokin and Activol) and an extract from algae (AlgaEnzims) were applied at commercial doses in potatoes (S. tuberosum L. var. gigant) with and objective to evaluate its effect on nutritional value (dry-matter, water content, ashes, fat, protein, carbohydrates and assimilable fiber). These parameters were analyzed according to the Official Methods of Analysis (AOAC). The experimental design was in Random Blocks with 8 treatments and 4 replications with 32 lots in total. The statistical analysis was after Random Blocks for all bromatological analyses. The treatment algae in soil gave the highest ash content (6.20). Algae in soil (9.30), algae on foliage (8.90) and Cytokin (8.70) gave the highest values in protein as compared with test (6.20). Carbohydrate content was highest in Biofol (88.21), assimilable fiber was higher in algae in soil and on foliage (5.84) and lowest with Biofol (1.67). Highest fat content in the tuber was obtained with Biozyme and Cytokin and highest protein content with AlgaEnzims. With Activol the highest tuber production is obtained.

Crops, Agricultural↗

PubMed1999

Platelet aging in vivo is associated with loss of membrane phospholipid asymmetry.

The mechanism(s) involved in the clearance of senescent platelets are largely unknown. The loss of membrane phospholipid (PL) asymmetry, with phosphatidylserine (PS) exposure appears to be an important signal for the ingestion by macrophages of apoptotic nucleated cells and it has also been suggested as a signal for the removal of aged erythrocytes. Accordingly, it seems possible that the clearance of normal aged platelets from circulation might be triggered by PS exposure. To investigate this, we determined PS exposure in human aging platelets taking advantage of the relationship between platelet density and platelet age and in dog platelets in a model of platelet aging in vivo. PS exposure was determined in two experimental conditions: 1) human platelet density subpopulations obtained by centrifugation in arabinogalactan gradients; 2) circulating canine platelets during decline in platelet count after suppression of thrombopoiesis following estradiol injection. PS exposure was determined by flow cytometry after labeling the cells with FITC-conjugated annexin V. The proportion of human platelets with exposed PS was significantly higher in high density (HD) platelets compared to low density (LD) platelets (11.3 +/- 8.0% vs 5.2 +/- 3.7%; p <0.05, respectively). In dogs, the proportion of cells with exposed PS rises dramatically with age, from 3.1 +/- 0.4% before to 17.7 +/- 12.3% ten days after estradiol injection. These findings suggest that platelet aging is associated with loss of phospholipid asymmetry and PS exposure on the outer leaflet of cell membrane, which may play an important role in the recognition and subsequent removal of senescent platelets.

Animals↗

PubMed1999

[Experimental vasectomy: comparison of epididymal structure with various surgical techniques].

OBJECTIVE: To analyze the effects of different surgical techniques of vasectomy on the epididymal structure. METHODS: Experimental vasectomies were performed in dogs using the conventional and open-ended techniques. The animals were orchidectomized 1 to 12 months after vasectomy and the epididymal structure was analyzed. RESULTS: The epididymal structure of dogs submitted to the conventional technique showed marked ectasia, reinforced basement membrane, loss of stereocilia in the principal cells, and formation of spermatic granulomas in interstitial tissue. At 12 months the principal cells showed signs of degenerative changes. In the different time periods analyzed in the study, no changes were observed in the epididymal structure of dogs submitted to the open-ended technique. CONCLUSIONS: The changes observed in the principal cells are ascribable to the increased intraluminal pressure produced by ligation of both ends of the vas deferens (conventional technique), since no changes were found in the epididymal structure of dogs submitted to the open-ended technique, at least in the different time periods analyzed in the study.

Animals↗

PubMed1998

Serum levels of intercellular adhesion molecule 1 (ICAM-1) in patients with colorectal cancer: inhibitory effect on cytotoxicity.

A positive correlation between the level of ICAM-1 in serum and the stage of neoplastic processes has been demonstrated. We studied ICAM-1 serum concentration in 27 colorectal cancer patients and investigated the effect of this molecule on cellular aggregation and toxicity. ICAM-1 serum concentration in the group of patients was significantly higher (P < 0.01) than in normal controls and was related to tumour stage. Patient sera inhibited both the formation of cellular aggregates and the percentage of specific lysis, the effect being lost when the serum was depleted of ICAM-1. These results suggest that the release of soluble ICAM-1 may represent a mechanism of tumour escape.

Aged↗

PubMed1998

Randomized trial comparing monthly low-dose leucovorin and fluorouracil bolus with weekly high-dose 48-hour continuous-infusion fluorouracil for advanced colorectal cancer: a Spanish Cooperative Group for Gastrointestinal Tumor Therapy (TTD) study.

PURPOSE: The objective of this multicenter study was to compare the efficacy and toxicity profiles of a combination of 5-fluorouracil (5-FU) given by bolus injection together with intravenous leucovorin (LV) versus high-dose 5-FU in continuous infusion (CI) in the treatment of advanced colorectal cancer. PATIENTS AND METHODS: A total of 306 patients were randomized to receive either 5-FU 425 mg/m2 given by bolus injection on days 1-5 plus intravenous (i.v.) LV 20 mg/m2 every four to five weeks or 5-FU 3.5 g/m2/week in a 48-hour CI. Therapy was continued until disease progression. Second-line chemotherapy was allowed in both arms. RESULTS: The response rates in 306 patients with measurable lesions were 19.2% (modulated arm) and 30.3% (CI arm, P < 0.05). The median progression-free survival times were 23.5 weeks (modulated arm) and 25 weeks (CI arm, P = NS). Median survival times were 42.5 weeks (modulated arm) and 48 weeks (CI arm, P = NS). There were no significant differences in grade 3-4 toxicity profiles but if we consider all grades we observed more mucositis in the modulated arm and more hand-foot syndrome in the CI arm. CONCLUSIONS: In terms of response rate, the continuous infusion regimen was more effective than the modulated regimen. There was no significant difference in survival and time to progression, and none in grade 3-4 toxicity.

Adult↗

PubMed1998

Seventy-two hour epirubicin infusion plus quinidine in unresectable and metastatic adenocarcinoma of the pancreas: a phase II trial.

Twenty-two previously untreated patients who had unresectable and metastatic pancreatic cancer were treated in a prospective phase II trial with high-dose continuous infusion epirubicin (45 mg/m2 once every 24 hours continuous infusion days 4 through 6) plus quinidine (495 mg once every 24 hours on days 1-6). There were no objective responses (0 of 18 evaluable patients). Subjective responses were achieved in 2 of 21 evaluable patients (9%), all of whom had good performance status (Eastern Cooperative Oncology Group: 0-1). Median survival was 5.7 months for the overall population. Two patients who exhibited symptomatic improvement achieved responses lasting 7 and 13 months, respectively. Toxicity was generally mild and tolerable. Little benefit regarding survival and quality of life was observed with the use of this regimen. The role in chemoresistance of mdrl, p53, and the mismatch repair system was examined.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1998

Nuclear factor-kappa B activity in T cells from patients with rheumatic diseases: a preliminary report.

OBJECTIVE: The NF-kappa B/Rel family of transcription factors regulates the expression of many genes involved in the immune or inflammatory response at the transcriptional level. The aim of this study was to determine whether distinctive patterns of NF-kappa B activation are seen in different forms of joint disease. METHODS: The DNA binding activity of these nucleoproteins was examined in purified synovial and peripheral T cells from patients with various chronic rheumatic diseases (12: four with rheumatoid arthritis; five with spondyloarthropathies; and three with osteoarthritis). RESULTS: Electrophoretic mobility shift assays disclosed two specific complexes bound to a NF-kappa B specific 32P-labelled oligonucleotide in nucleoproteins extracted from purified T cells isolated from synovial fluid and peripheral blood of patients with rheumatoid arthritis. The complexes consisted of p50/p50 homodimers and p50/p65 heterodimers. Increased NF-kappa B binding to DNA in synovial T cells was observed relative to peripheral T cells. In non-rheumatoid arthritis, binding of NF-kappa B in synovial T cells was exclusively mediated by p50/p50 homodimers. CONCLUSION: Overall, the results suggest that NF-kappa B may play a central part in the activation of infiltrating T cells in chronic rheumatoid arthritis. The activation of this nuclear factor is qualitatively different in rheumatoid synovial T cells to that in other forms of non-rheumatoid arthritis (for example, osteoarthritis, spondyloarthropathies).

Adolescent↗

PubMed1997

Endothelial cell markers in chronic uremia: relationship with hemostatic defects and severity of renal failure.

Plasma von Willebrand factor antigen, soluble thrombomodulin, and tissue factor were increased in 31 patients with severe chronic renal failure (creatinine clearance <20 ml/min) under conservative treatment, whereas plasminogen activator inhibitor antigen did not differ significantly from healthy controls. No correlation among plasma levels of these proteins was found. Three patterns of relationship between endothelial cell markers and hemostatic defects were identified: 1) Plasma thrombomodulin, a marker of endothelium damage, was found an independent predictor of bleeding time and platelet aggregation, and secretion defects, and was also related to the severity of renal failure; 2) von Willebrand factor antigen, an index of endothelial cell activation and secretion, was significantly correlated with intravascular markers of thrombin and plasmin generation and with platelet adenosine triphosphate content, but not with plasma creatinine levels; and 3) tissue factor and plasminogen activator inhibitor antigen levels were not statistically correlated with the diverse hemostatic defects. Activation of coagulation and fibrinolysis, secondary to endothelial cell activation, appearing early during the evolution of chronic renal failure, is pathogenically related to the platelet dysfunction, and probably to development of atherosclerosis and thrombotic events in this disease. The progression of chronic renal failure, through endothelial cell damage, would lead to aggravation of the platelet functional defect potentiating the hemorrhagic risk.

Antigens↗

PubMed1997

Modified weekly regimen with vinorelbine as a single agent in unresectable non-small cell lung cancer.

After a 26% response rate was reported with a 20/mg/m2/week vinorelbine (VRL) dose, a multicenter phase II trial of a modified weekly VRL treatment protocol (30 mg/m2 days 1 and 8 every 21 days) for unresectable non-small cell lung cancer (NSCLC) was designed to determine its clinical activity, toxicity, and survival of treated patients. As myelotoxicity frequently precludes the administration of VRL, by suppressing the dose that would correspond to day 15 of a weekly protocol, we allowed bone marrow recovery to take place and avoided the administration of the drug at the nadir of the cycle. The trial included 71 consecutive, previously untreated patients with unresectable and measurable disease. A total of 297 three-week treatment courses were administered with an average of 4 courses per patient (range 1-11). Results showed that in spite of attaining a median dose intensity of 19 mg/m2/week, this modified weekly VRL treatment regimen has a low level of activity (7.5% response rate) in NSCLC. Although a more tolerable level of toxicity is achieved, in order to maintain its antitumor activity, the recommended dose of VRL when given alone for NSCLC treatment (30 mg/m2/weekly) should not be decreased.

Adult↗