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Biomedical subjects

D R Spriggs

Publications and source records attributed to D R Spriggs.

96 records · Page 6Linked to original sources
PubMed1974

Role of mycobactin in the growth and virulence of tubercle bacilli.

Tubercle bacilli failed to grow in iron-void media enriched with solutions of iron-containing transferrin (Tr) or ferritin (F) because these substances do not provide the bacilli with iron, which is essential for their growth. Animal serum and macrophages possessed no iron carrier with an ability to satisfy the need of the bacteria for the metal. Mycobactin (M), the growth-product of tubercle bacilli, removed iron from Tr and F and supplied the metal for bacillary utilization. The role of M in the growth of tubercle bacilli was influenced by nonionic surfactants which inhibited bacillary growth by removing M from the bacillary cells and interfering with the absorption of M-iron complexes. Experiments with Tween 80, Triton WR-1339, and lecithin showed that avirulent bacilli lose M at lower concentrations of the surfactants than virulent bacilli. Since avirulent and virulent bacilli possess the same amount of M, these findings indicate that M is bound more firmly to lipid-rich virulent than lipid-poor avirulent cells. These findings indicate that the resistance of virulent bacilli to the M-removing activity of the surfactants is an indicator of their ability to multiply in the infected host and may be used as a measure of bacillary virulence.

Bacteriological Techniques↗
PubMedDate not supplied

Multi-institutional phase 2 study of TLK286 (TELCYTA, a glutathione S-transferase P1-1 activated glutathione analog prodrug) in patients with platinum and paclitaxel refractory or resistant ovarian cancer.

The purpose of this study was to determine the safety and efficacy of TLK286 (TELCYTA(TM)), a glutathione analog prodrug, in patients with platinum and paclitaxel refractory or resistant ovarian carcinoma. Thirty-six patients with measurable disease were enrolled. TLK286 was administered at 1000 mg/m2 intravenously every 3 weeks. The endpoints were objective response rate assessed by Response Evaluation Criteria in Solid Tumors (RECIST) and survival. Adverse events were graded using the National Cancer Institute Common Toxicity Criteria. Thirty-four platinum refractory or resistant patients (94%) were evaluable for objective tumor response. Five patients (15%) had objective tumor responses, including one durable complete response (CR) of greater than 3 years and continuing. The disease stabilization rate was 50%, including one CR (3%), four partial responses (12%), and 12 durable disease stabilizations (35%). Responses were accompanied by improvement in clinical symptoms and Eastern Cooperative Oncology Group Performance Status (ECOG PS) and decline in CA125 levels. Median survival was 423 days with survival of 60% at 1 year and 40% at 18 months. TLK286 was well tolerated in this population. TLK286 is an active agent in chemotherapy-resistant ovarian cancer. Further studies of TLK286 in platinum and paclitaxel refractory or resistant ovarian cancer are in progress.

Adult↗
PubMedDate not supplied

New agents for the treatment of ovarian cancer: the next generation.

Ovarian cancer shares many important characteristics with more common malignancies including breast, lung, and colon cancer. The relative chemosensitivity of ovarian cancer and other aspects of its unique biology provide opportunities for novel interventions. In this brief summary, some of the potential targets in ovarian cancer are discussed, including the HER kinases, heat shock protein, the 26S proteasome, and the angiogenesis pathway. The opportunities to change the treatment of ovarian cancer will require creative clinical trial design but the next decade promises to be filled the therapeutic advances for patients with ovarian cancer.

Angiogenesis Inhibitors↗
PubMedDate not supplied

Phase II study of tirapazamine plus cisplatin in patients with advanced or recurrent cervical cancer.

The aim of this study was to evaluate the activity and toxicity of a tirapazamine (TPZ)/cisplatin drug combination in patients with stage IV or recurrent cervical cancer. The chemotherapy was administered for a maximum of eight cycles every 21 days. TPZ was administered intravenously at 330 mg/m(2) over a 2-h infusion, followed 1 h later by cisplatin intravenously at 75 mg/m(2) over 1 h on day 1. All patients received antiemetics including dexamethasone, ondansetron, and lorazepam. Subsequent doses were unchanged, reduced, or omitted according to observed toxicity and protocol guidelines. Response evaluation was performed every two cycles. Thirty-six patients with stage IV or recurrent cervical cancer were treated. Ninety-four percent of patients had prior radiotherapy. Two patients had prior chemotherapy. There were two complete responses and eight partial responses (27.8%). An additional 11 patients (30.6%) had stable disease as their best response. Response rate was greater in tumors outside of the previously radiated field (44.4% vs 11.1%). The median time to progression was 32.7 weeks. The most frequent grade 3 or 4 adverse events were nausea, vomiting, and fatigue, which occurred in 30.6%, 25%, and 22% of subjects, respectively. Anemia was the most frequent grade 3 or 4 hematologic toxicity at 8.3%. We conclude that the combination of cisplatin and TPZ was reasonably well tolerated in patients with recurrent or advanced cervical cancer. Further evaluation of this drug combination may be warranted.

Adult↗