Biomedical subjects

D P Calvin

Publications and source records attributed to D P Calvin.

3 recordsLinked to original sources

PubMed2000

Quantitative analysis of DNA array autoradiographs.

DNA arrays and chips are powerful new tools for gene expression profiling. Current arrays contain hundreds or thousands of probes and large scale sequencing and screening projects will likely lead to the creation of global genomic arrays. DNA arrays and chips will be key in understanding how genes respond to specific changes of environment and will also greatly assist in drug discovery and molecular diagnostics. To facilitate widespread realization of the quantitative potential of this approach, we have designed procedures and software which facilitate analysis of autoradiography films with accuracy comparable to phosphorimaging devices. Algorithms designed for analysis of DNA array autoradiographs incorporate 3-D peak fitting of features on films and estimation of local backgrounds. This software has a flexible grid geometry and can be applied to different types of DNA arrays, including custom arrays.

Algorithms↗

PubMed1999

Blockage of the vascular endothelial growth factor stress response increases the antitumor effects of ionizing radiation.

The family of vascular endothelial growth factor (VEGF) proteins include potent and specific mitogens for vascular endothelial cells that function in the lation of angiogenesis Inhibition of VEGF-induced angiogenesis either by neutralizing antibodies or dominant-negative soluble receptor, blocks the growth of primary and metastatic experimental tumors Here we report that VEGF expression is induced in Lewis lung carcinomas (LLCs) both in vitro and vivo after exposure to ionizing radiation (IR) and in human tumor cell lines (Seg-1 esophageal adenocarcinoma, SQ20B squamous cell carcinoma, T98 and U87 glioblastomas, and U1 melanoma) in vitro. The biological significance of IR-induced VEGF production is supported by our finding that treatment of tumor-bearing mice (LLC, Seg-1, SQ20B, and U87) with a neutralizing antibody to VEGF-165 before irradiation is associated with a greater than additive antitumor effect. In vitro, the addition of VEGF decreases IR-induced killing of human umbilical vein endothelial cells, and the anti-VEGF treatment potentiates IR-induced lethality of human umbilical vein endothelial cells. Neither recombinant VEGF protein nor neutralizing antibody to VEGF affects the radiosensitivity of tumor cells These findings support a model in which induction of VEGF by IR contributes to the protection of tumor blood vessels from radiation-mediated cytotoxicity and thereby to tumor radioresistance.

Adenocarcinoma↗

PubMed1999

Surgery and postoperative radiation therapy in stage II endometrial carcinoma.

The traditional approach to patients with stage II endometrial carcinoma is preoperative radiation therapy (RT) followed by surgery. Currently, many patients are treated with primary surgery and postoperative RT. We retrospectively reviewed the outcome of 44 stage II (32 IIA, 12 IIB) patients who underwent surgery and postoperative RT. Nine (20%) had microscopic cervical involvement noted before surgery, and 35 (80%) had occult involvement noted postoperatively. Postoperative RT consisted of whole pelvic RT (WPRT) (50%), vaginal brachytherapy (VB) (18%), or both (32%). At a median follow-up of 40 months, the 5-year actuarial disease-free survival was 72.4%. Two patients (4%) had recurrence in the pelvis (one vagina, one lateral pelvis). Eighteen stage IIA patients treated with WPRT alone and eight stage IIA patients, without deep myometrial invasion (MI), were treated with VB alone, and remained controlled in the pelvis. Extrapelvic recurrences occurred in 12 patients (25%), primarily in those with deep MI and/or grade 2-3 disease. Our results suggest that patients with stage II endometrial carcinoma with microscopic or occult cervical involvement treated with surgery and postoperative RT have a favorable outcome. A high rate of pelvic control is achieved with RT tailored to the pathologic findings.

Adult↗