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Biomedical subjects

P G Sorensen

Publications and source records attributed to P G Sorensen.

7 recordsLinked to original sources
PubMed2001

Superiority of high-dose platinum (cisplatin and carboplatin) compared to carboplatin alone in combination chemotherapy for small-cell lung carcinoma: a prospective randomised trial of 280 consecutive patients.

PURPOSE: A prospective randomized trial in small-cell lung cancer (SCLC) was performed to determine if intensification of the platinum dose by giving cisplatin and carboplatin in combination to patients with SCLC yields higher response rates and survival, than carboplatin alone in a combination chemotherapy regimen. PATIENTS AND METHODS: Between September 1992 and October 1997, 280 patients were included in a two armed prospective randomized trial, stratified by stage of disease, LDH and performance status. The treatment was in arm A: three courses induction chemotherapy with carboplatin (AUC = 4, day 1), cisplatin (35 mg/m2, days 2 and 3), teniposide (50 mg/m2, day 1-5), vincristine (1.3 mg/m2, day 1) every four weeks, followed by cyclophosphamide (3 g/m2, day 84), 4-epirubicin (4-epidoxorubicin) (150 mg/m2, day 112), and finally one course cisplatin, carboplatin, teniposide and vincristine, (days 140-144). Arm B also comprised a total of six courses, identical to those in arm A except for omission of cisplatin. RESULTS: There were no significant differences in the overall treatment outcome for A vs. B, in terms of response rates (72% in both arms), complete response rates (40% and 34%, respectively), or median survival (314 days and 294 days, respectively). However, for patients with limited disease both the CR rate (54% vs. 37%, P < 0.05), overall survival (log-rank test, P < 0.05), and the two-year survival rate (11% vs. 6%, P < 0.05) were higher in the high-dose platinum arm compared to the carboplatin alone arm. CONCLUSIONS: The intensification of platinum dose (cisplatin plus carboplatin) in combination chemotherapy significantly increased the complete response rate, overall survival and number of two-year survivors among SCLC patients with limited disease compared to combination therapy with carboplatin alone, suggesting that a more aggressive treatment to this category of patients is worthwhile, while no difference in treatment outcome was observed for patients with extensive disease.

Adult↗
PubMed2000

Exploratory phase III study of paclitaxel and cisplatin versus paclitaxel and carboplatin in advanced ovarian cancer.

PURPOSE: To determine the side effects and feasibility of cisplatin and carboplatin each in combination with paclitaxel as front-line therapy in advanced epithelial ovarian cancer. PATIENTS AND METHODS: Patients were randomly allocated to receive paclitaxel 175 mg/m(2) intravenously as a 3-hour infusion followed by either cisplatin 75 mg/m(2) or carboplatin (area under the plasma concentration-time curve of 5), both on day 1. The schedule was repeated every 3 weeks for at least six cycles. Women allocated to paclitaxel-cisplatin were admitted to the hospital, whereas the carboplatin regimen was administered to outpatients. RESULTS: A total of 208 eligible patients were randomized. Both regimens could be delivered in an optimal dose and without significant delay. Paclitaxel-carboplatin produced significantly less nausea and vomiting (P: <.01) and less peripheral neurotoxicity (P: =.04) but more granulocytopenia and thrombocytopenia (P: <.01). The overall response rate in 132 patients with measurable disease was 64% (84 of 132 patients), and in patients with elevated CA 125 levels at start, it was 74% (132 of 178 patients). With a median follow-up time of 37 months, the median progression-free survival time of all patients was 16 months and the median overall survival time was 31 months. The small number of patients entered onto the study caused wide confidence intervals (CIs) around the hazards ratio for progression-free survival of paclitaxel-carboplatin compared with paclitaxel-cisplatin (hazards ratio, 1.07; 95% CI, 0.78 to 1.48) and did not allow conclusions about efficacy. CONCLUSION: Paclitaxel-carboplatin is a feasible regimen for outpatients with ovarian cancer and has a better toxicity profile than paclitaxel-cisplatin.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Regulation of UDP-3-O-[R-3-hydroxymyristoyl]-N-acetylglucosamine deacetylase in Escherichia coli. The second enzymatic step of lipid a biosynthesis.

The first enzyme of lipid A assembly in Escherichia coli is an acyltransferase that attaches an R-3-hydroxymyristoyl moiety to UDP-GlcNAc at the GlcNAc 3-OH. This reaction is reversible and thermodynamically unfavorable. The subsequent deacetylation of the product, UDP-3-O-[R-3-hydroxymyristoyl]-GlcNAc, is therefore the first committed step of lipid A biosynthesis. We now demonstrate that inhibition of either the acyltransferase or the deacetylase in living cells results in a 5-10-fold increase in the specific activity of the deacetylase in extracts prepared from such cells. Five other enzymes of the lipid A pathway are not affected. The elevated specific activity of deacetylase observed in extracts of lipid A-depleted cells is not accompanied by a significant change in the Km for the substrate, but is mainly an effect on Vmax. Western blots demonstrate that more deacetylase protein is indeed made. However, deacetylase messenger RNA levels are not significantly altered. Inhibition of lipid A biosynthesis must either stimulate the translation of available mRNA or slow the turnover of pre-existing deacetylase. In contrast, inhibition of 3-deoxy-D-manno-octulosonic acid (Kdo) biosynthesis has no effect on deacetylase specific activity. The underacylated lipid A-like disaccharide precursors that accumulate during inhibition of Kdo formation may be sufficient to exert normal feedback control.

Amidohydrolases↗
PubMed1976

Vincristine (NSC-67574) in the treatment of small-cell anaplastic carcinoma of the lung.

In a phase II trial the effect of vincristine as a single agent was evaluated in patients with small-cell anaplastic carcinoma of the lung. The dosage of vincristine was 1.5 mg/m2/week given iv for 4 weeks, followed by 1.5 mg/m2 given every other week with dose modifications according to neurologic tolerance. Nineteen of 27 patients included in the study were evaluable. Objective response was observed in eight patients (42%) including three who were not previously treated and five who were previously treated. The median duration of response was 60 days (range, 21-182 days) with the response always occurring within 4 weeks. This study demonstrates that vincristine is an active agent for small-cell anaplastic carcinoma without cross resistance to CCNU, cyclophosphamide, or methotrexate.

Aged↗