Biomedical subjects

I Porras

Publications and source records attributed to I Porras.

16 recordsLinked to original sources

PubMed2006

Deficit irrigation and rootstock: their effects on water relations, vegetative development, yield, fruit quality and mineral nutrition of Clemenules mandarin.

Differences between rootstocks, 'Cleopatra' mandarin and 'Carrizo' citrange, in soil-plant water relations and the influence of these factors on vigor, crop yield, fruit quality and mineral nutrition were evaluated in field-grown Clemenules mandarin trees irrigated at 100% of potential seasonal evaporation (ET(c)) (control treatment), or irrigated at 100% ET(c), except during Phases I and III of fruit growth and post-harvest when no irrigation was applied (deficit irrigation (DI) treatment), for 3 years. Differences between rootstocks in plant-soil water relations were the primary cause of differences among trees in vegetative development and fruit yield. After 3 years of DI treatment, trees on 'Cleopatra' showed more efficient soil water extraction than trees on 'Carrizo', and maintained a higher plant water status, a higher gas exchange rate during periods of water stress and achieved faster recovery in gas exchange following irrigation after water stress. The DI treatment reduced vegetative development more in trees on 'Carrizo' than in trees on 'Cleopatra'. Cumulative fruit yield decreased more in DI trees on 'Carrizo' (40%) than on 'Cleopatra' (27%). The yield component most affected by DI in 'Cleopatra' was the number of fruit, whereas in 'Carrizo' it depended on the severity of water stress reached in each phase (severe water stress in Phase I affected mainly the number of fruit, whereas it affected fruit size the most in Phase III). In the third year of DI treatment, water-use efficiency decreased sharply in trees on 'Carrizo' (70%) compared to trees on 'Cleopatra' (30%). Thus, trees on 'Cleopatra' were able to tolerate moderate water stress, whereas trees on 'Carrizo' were more sensitive to changes in soil water content.

Agriculture↗

PubMed2001

Biweekly gemcitabine, doxorubicin, and paclitaxel as first-line treatment in metastatic breast cancer. Final results from a phase II trial.

In a single-center, open, phase II trial, we assessed the toxicity and activity of a triple combination therapy--doxorubicin at 30 mg/m2 (day 1), paclitaxel (Taxol) at 135 mg/m2 (day 2), and gemcitabine (Gemzar) at 2,500 mg/m2 (day 2 after paclitaxel)--administered biweekly in a 28-day cycle for six cycles. This was given as first-line treatment in 41 patients with metastatic breast cancer. Granulocyte colony-stimulating factor was used in 27 patients to permit maintenance of dose density. Hematologic toxicity was moderate. Nonhematologic adverse events were generally mild. The objective response rate was 82.9% (34/41) with 18 patients (43.9%) achieving complete response and 16 (38%) achieving partial response; progressive disease was observed in 4 patients (9.8%). Responses were observed at all metastatic sites, including complete responses in lung, liver, bone, and soft tissue. Median duration of response was 14.1 months and median time to progression was 13.9 months. Median survival was 26.2 months. The biweekly combination of gemcitabine, doxorubicin, and paclitaxel is safe and highly active as first-line treatment in metastatic breast cancer.

Adult↗

PubMed2000

Phase II trial of gemcitabine/doxorubicin/paclitaxel administered every other week in patients with metastatic breast cancer.

The present trial was designed to determine the efficacy of the combination of gemcitabine/doxorubicin/paclitaxel (GAT) delivered every other week as first-line therapy in patients with metastatic breast cancer. From February 1998 to September 1999, 41 patients were included in this trial. Doses delivered were doxorubicin 30 mg/m2 on day 1 and paclitaxel 135 mg/m2 plus gemcitabine 2500 mg/m2 both given on day 2, every 14 days. Doses were selected from a previous phase I trial conducted at our institution. Eligibility criteria for the phase II trial included histologically confirmed metastatic breast cancer with bidimensionally measurable lesions; no prior therapy for metastatic disease; adjuvant or neoadjuvant chemotherapy was allowed if given more than 1 year before and cumulative doses of doxorubicin or epirubicin were less than 200 mg/m2 or 360 mg/m2, respectively; Eastern Cooperative Oncology Group (ECOG) performance status of 2 or less; and adequate hematological, hepatic, and renal function. Prophylactic use of granulocyte colony-simulating factor (G-CSF) was allowed if patients were not fully recovered (absolute neutrophil count greater than 1500/microL) from chemotherapy administration before the next dose. Left ventricular ejection fraction was determined initially, at the end of the study, and every 6 months thereafter. The patients' median age was 55 years (range, 33-68 years), and their median ECOG performance status was 0 (range, 0-1). Twenty-eight patients had received adjuvant therapy, 17 with epirubicin (none with doxorubicin). Metastases were present in the bone (19 patients), lung (19 patients), liver (11 patients), and soft tissues (18 patients). Twenty patients had one metastatic site and 21 had two or more sites. Efficacy was assessed on an intent-to-treat basis. A total of 216 cycles of GAT were given. Twenty-two percent of the courses were delayed or given at reduced doses mostly due to neutropenia or thrombocytopenia. G-CSF was required in 58% of the cycles. Grade 3/4 neutropenia was the main toxicity and appeared in 17 patients, one of whom had an episode of febrile neutropenia. Nonhematological toxicities consisted mainly of neurotoxicity and myalgias. A drop of 10%-20% in the left ventricular ejection fraction was detected in two patients and another patient had a decrease greater than 20%, although none developed symptoms of heart failure. Overall response rate was 80.4% (95% confidence interval: 68.3-92.5), with 15 patients (36.6%) achieving a complete response. Median survival time was 27 months and median time to progression was 15 months. The GAT combination is feasible and very active in patients with metastatic breast cancer, with an encouraging response rate including a high rate of complete responses. No congestive heart failure was documented and other toxicities were mild, with the exception of neutropenia.

Adult↗

PubMed1995