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Biomedical subjects

R D Tucker

Publications and source records attributed to R D Tucker.

At least 55 records · Page 3Linked to original sources
PubMed1983

Radical irradiation and misonidazole in the treatment of T2 grade III and T3 bladder cancer.

The results of 2 pilot studies using a new radiation fractionation schedule plus misonidazole (MISO) in the radical radiotherapy of T2 Grade III and T3 carcinoma of the bladder are presented. Forty Gy in 20 daily fractions of 2 Gy was administered to the whole pelvis over 4 weeks followed by 12 Gy in 2 weekly fractions of 6 Gy. These last 2 doses were given after MISO administration. In an initial pilot study (Pilot Study I) MISO was administered orally only. The first two patients received MISO at a dose of 4.5g/m2 orally with each radiation fraction, after which the dose was reduced to 3.0g/m2 because of drug toxicity. In the second pilot study (Pilot Study II) MISO was administered orally at a dose of 3.0g/m2 and intravesically at a dose of 1.0g to 22 patients. The complete response rate at cystoscopy at 6 months in the latter group of patients is 73%, which is significantly better than that of 43% obtained in a retrospective study of historical controls. There have been no late radiation complications in any of the patients nor any MISO toxicity apart from nausea in the patients receiving 3.0g/m2 orally with or without the intravesical MISO.

Administration, Oral↗
PubMed1982

Radiotherapy of regional epidermoid carcinoma of the lung: a study in fractionation.

This paper reports a prospective randomized multicenter trial of two fractionation schemes in the supervoltage radiotherapy of locally inoperable epidermoid lung cancer. This study was stimulated by the need to provide improved and more acceptable treatment methods for patients with this condition, the most common cell type of lung cancer. The majority of such patients are not suitable for resection because of metastasis or because of extensive local disease, even though exploratory thoracotomy may be performed. It was therefore considered important to identify preferred methods of irradiation in this situation which is found in a large proportion of patients with lung cancer.

Adult↗
PubMed1980

Chemotherapy of extensive large cell and adenocarcinoma of the lung: a randomized trial in 210 patients.

Two hundred ten patients with advanced adenocarcinoma of the lung were entered into a two-arm randomized trail. Cytoxan + CCNU + methotrexate was compared to Adriamycin and procarbazine. The tumor response to CCM was significantly higher than the tumor response to Adriamycin and procarbazine. No significant difference existed between the two treatments with respect to survival. Initial performance status, weight loss prior to therapy, and response to therapy were all found to be significant prognostic factors. Median survival time relative to responders in both treatment groups was 31.7 weeks and 15.8 weeks for non-responders.

Adenocarcinoma↗
PubMed1979

Cystic fibrosis serum effect on the short circuit current of rat jejunum.

Sera from 100 subjects were tested for the presence of the cystic fibrosis (CF) "factor" utilizing the short circuit current rat jejunum bioassay. Comparing the mean percent decrease in short circuit current, the presumed normal group differs from the homozygous CF group at P = 0.001 and from the heterozygous group at P = 0.05. The two CF genotypes are statistically different at P = 0.004. There is, however, a large overlap among the three groups, which limits the assay's utility as a guide for factor purification as well as clinical use.

Animals↗
PubMed1978

Chemotherapy of small cell carcinoma of the lung with V.P. 16-213.

A Phase II study of V.P. 16-213 administered to 47 patients suffering from small cell carcinoma of the bronchus. V.P. 16-213 was given as an intravenous infusion over 15 minutes daily for five consecutive days using 60 mg/m2/d at 14-day intervals. Oral V.P. in 100 mg doses was given twice a week between the intravenous courses. Objective response rate for this drug compared favourably with that of other single agents reported. All but two patients showed a degree of response to treatment and 24 of 47 patients showed a true objective response to treatment. The overall median survival of these patients was 225 days and localized disease 278 days. The quality of survival was such that responders lived relatively normal lives up to the latter stages of their disease. The majority of patients had a marked response in performance status, 37 out of 47 showing an improvement. Three patients are alive and well at more than 27 months. In all cases the side effects were minimal. Alopecia was common and reversible haematological complications occurred. Severe toxicity was not encountered and the drug was well tolerated with supportive antiemetic therapy at onset of treatment.

Bone Marrow↗
PubMed1976

Combination chemotherapy of advanced lung cancer: a randomized trial.

A controlled clinical trial comparing two-drug and three-drug combination chemotherapy was performed in 206 patients with advanced bronchogenic carcinoma, comprised of 26.2% with epidermoid carcinoma, 30.1% with small cell anaplastic carcinoma, 27.2% with adenocarcinoma, and 15.6% with large cell carcinoma. Each drug combination consisted of agents with different modes of action and included a cell-cycle-stage nonsensitive and a cell-cycle-state-sensitive agent. The overall response rate was highest for small cell carcinoma (48.2%) and adenocarcinoma (23.6%); it was less than 10% in epidermoid and large cell carcinoma. Similarly, the overall median survival was twice as long for the first two cell types (7 months) as compared with that recorded for the other two cell types (3 1/2 months). The combination of 1 (2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU), cyclophosphamide, and methotrexate was shown to be statistically superior to cyclophosphamide and methotrexate with regard to objective respones rate, duration of response, and median survival for adenocarcinoma. Responders lived significantly longer than nonresponders (254 versus 90 days for small cell anaplastic carcinoma patients and 244 versus 184 days for adenocarcinoma patients). No difference in survival or objective response rate was observed between the different treatments for the other two cell types of lung cancer.

Adenocarcinoma↗
PubMedDate not supplied

Bipolar electrosurgical sphincterotomy.

We tested a newly developed bipolar sphincterotome. Monopolar and bipolar sphincterotomes were employed to cut small bowel smoothly and hemostatically. The bipolar instrument required 17.1 watts while the monopolar required 29.2 watts; these values are significantly different at p = 0.005. Bipolar sphincterotomies were performed via open surgical access on eight dogs. The animals were allowed to recover and were followed for 6 weeks. There was no evidence of stenosis or common duct dilation at autopsy, and serum alkaline phosphatase and bilirubin were within normal limits. Both sphincterotomes were used to cut tissue in vitro and histological examination displayed no evidence of thermal injury at the return electrode site of the bipolar sphincterotome. The lower power levels required by the bipolar sphincterotome may decrease procedure complications.

Ampulla of Vater↗
PubMedDate not supplied

The interaction between electrosurgical generators, endoscopic electrodes, and tissue.

Endoscopic monopolar and bipolar devices were compared during cutting and coagulation. It was observed on appropriate animal models that the initial resistance (impedance) values recorded correspond to the normal tissue impedance at the electrode. The subsequent impedance values increase 25 to 50 ohms for the coagulator which relates to tissue desiccation and for the cutting electrodes the impedance increases greater than 1000 ohms during the arcing process. At similar power settings, typical monopolar generators produce maximum power at 300 to 500 ohms while typical bipolar generators produce maximum power at 25 to 100 ohms. With impedances greater than 1000 ohms, monopolar generators are capable of higher power output than are bipolar generators. Since cutting is a high impedance process, bipolar cutting electrodes do not perform as intended with typical bipolar generators. Therefore, bipolar cutting electrodes should be employed with a monopolar generator or a generator designed specifically for their use.

Animals↗
PubMedDate not supplied

The effect of guidewires during electrosurgical sphincterotomy.

We describe six electrosurgical incidents and one complication which occurred during guidewire-assisted sphincterotomy. Studies were conducted on three types of guidewires: Teflon painted, Teflon sheathed, and polymer coated. Scanning electron micrographs demonstrated surface imperfections in the painted Teflon guidewire coating, which allowed for potential electrical short circuits between cutting wire and guidewire through a septal defect in a double channel catheter. Septal defects were found in 25% (1 of the 4 tested) of the factory fresh sphincterotomes that were used in this study, and in 10% (6 of 57) of those used clinically. Induced current (capacitively coupled) present on the guidewires was measured at 13 to 30 mA for typical sphincterotomy settings. The induced current on sheathed guidewires, without any insulation defects, was measured at less than 1 mA at typical operating powers. As both short circuits and induced currents place the patient at risk for burns or perforation at the distal end of the guidewire, we suggest the use of a Teflon-sheathed rather than Teflon-painted guidewire, if the wire is to be left in place during sphincterotomy. The Teflon sheath offers the thickest insulation, a very low probability of surface defects, and therefore a high index of safety.

Aged↗