Synthesis of 6,7-benzo-3-methoxyestra-1,3,5(10),8,14-pentaen-17-one.
Explore the source record for details and available documents.
Estrenes↗
Biomedical subjects
K Rajagopalan
Publications and source records attributed to K Rajagopalan.
Heterobifunctional cross-linking agents incorporating perfluorinated aryl azides.
New heterobifunctional cross-linking reagents were developed that possess a photoactive tetrafluorinated phenyl azide as the photoactive terminus and a chemically reactive succinimidyl ester as the electrophilic terminus. These reagents, succinimidyl N-(4-azido-2,3,5,6-tetrafluorobenzoyl)tyrosinate (9) and succinimidyl 2-(4-azido-2,3,5,6-tetrafluorophenyl)thiazole-4-carboxylate (15), were designed to possess either an 125I or 35S radiolabel, respectively. In a biochemical study, the latter reagent was coupled to Lys-75 of calmodulin (CaM), and the radioiodinated monoadduct was photochemically cross-linked, in a calcium-dependent manner, to the porcine erythrocyte plasma membrane Ca2+, Mg2(+)-ATPase. Densitometry scans of the gel indicated a reproducible 22% cross-linking of the CaM with one of the Ca2+,Mg2(+)-ATPase bands. Since the purification of the Ca2+,Mg2(+)-ATPase results in micelles having Ca2+,Mg2(+)-ATPase with its CaM binding site oriented both to the inside and outside of the micelle, the amount of Ca2+,Mg2(+)-ATPase available for cross-linking was reduced by approximately half, suggesting that the actual cross-linking efficiency was on the order of 40%.
Animals↗
Phase II trial of circadian infusion floxuridine (FUDR) in hormone refractory metastatic prostate cancer.
Circadian administration of chemotherapy has been reported to decrease toxicity and possibly enhance efficacy. Between March 1991 and December 1993, 18 evaluable patients with progressive, hormone-refractory metastatic prostate cancer were treated in this phase II trial of circadian infusion floxuridine (FUDR). The drug was delivered through a central venous catheter using a CADD-Plus computerized pump such that approximately 70% of the drug was administered between 3 and 9 p.m. and the rest (30%) was administered between 9 p.m. and 3 p.m. The dose of FUDR was 0.15 mg/kg/day x 14 days every 4 weeks. A total of 79 complete cycles was administered. Two of 18 evaluable patients (11.1%) had decreases in PSA lasting five and eight months. No objective responses or improvement in bone scans was noted. The major toxicity observed was diarrhea. Although circadian infusion FUDR is feasible and tolerable, it has limited activity in hormone refractory prostate cancer.
Antimetabolites, Antineoplastic↗
Electrohydraulic ventricular assist device development.
An electrohydraulic ventricular assist device has been developed. An axial flow pump driven by a brushless DC motor provides actuation. Energy is supplied by internal Ni/Cd batteries and by external Ag/Zn batteries, both rechargeable. Electromagnetic induction is used to pass energy through the skin with a transcutaneous energy transfer (TET) system. Physiologic control, battery management, motor commutation, and communication functions are performed by a surface mount internal controller. An infrared data link within the TET coils provides bidirectional communication between the external and internal controllers. A computer model was developed to predict system performance. The dimensions are 180 mm x 116 mm x 40 mm. An in vitro system pumped 5.7 L/min at 10 mmHg inflow and 100 mmHg outflow pressure. The internal battery can provide the projected energy requirements for 40 min after 540 charge/discharge cycles, and the external battery is capable of 4 hr of operation after 150 cycles. The TET system can deliver 60 W of power and exceeds 80% efficiency between 15 and 30 W. The device configuration is based on human cadaver and intraoperative fit trials. The device is being modified for calf implantation by redirecting the blood ports, increasing the output, and incorporating the internal controller in the unified device base.
Animals↗
Assessment of reused catheters.
Demands for health care cost containment have prompted the assessment of recycling medical devices, including catheters. The investigation of catheter reuse for effectiveness and safety began at the University of Ottawa Heart Institute in early 1994. This report provides the preliminary results from this ongoing assessment on the feasibility of catheter reuse. Burst tests were conducted to detect changes in catheter mechanical integrity. Scanning electron microscopy (SEM) was performed to assess surface changes and protein deposition after use and the subsequent cleaning process. Results of burst testing showed no significant difference in burst patterns or burst pressures between single use and unused catheters. Surface differences were observed between used and unused catheters. SEM studies detected physical changes such as scratches, gouges, cuts, and deposits on the used catheters. Unused balloon surfaces appeared to be clean and uniform compared to used ones. Residue and cracking were identified on other used devices. In conclusion, the methods used can assess various effects of recycling. A blind study of large samples of used catheters is planned to establish statistically the level and variance of structural damage to catheters during typical use.
Catheterization↗