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Biomedical subjects

D D Lawrence

Publications and source records attributed to D D Lawrence.

14 recordsLinked to original sources
PubMed1996

Therapy of locally recurrent renal cell carcinoma after nephrectomy.

PURPOSE: We evaluated the outcome of patients with locally recurrent renal cell carcinoma treated at our university. MATERIALS AND METHODS: We retrospectively analyzed 16 cases of locally recurrent renal cell carcinoma in the renal fossa treated with surgical resection alone or in combination with biological therapy. RESULTS: Complete resection was possible in 15 patients of whom 3 had positive surgical margins. Of the 12 patients with negative margins 6 are free of disease while the 3 with positive margins had involvement of a remaining ipsilateral adrenal gland and distant metastasis. Of all 16 patients 12 are alive a median of 23.5 months after the diagnosis of locally recurrent renal cell carcinoma. Of those treated with the combination of biological therapy and surgery 50% have no evidence of disease compared to 25% of those treated with surgery alone. CONCLUSIONS: Long-term survival can be achieved with an aggressive surgical approach. Incomplete resection or positive surgical margins are associated with a high risk of local or distant failure, and combined treatment with immunotherapy and surgery may offer a benefit compared to surgery alone.

Carcinoma, Renal Cell↗
PubMed1995

Prolonged stabilization of progressive endometrial stromal sarcoma with prolonged oral etoposide therapy.

We report the case of a patient who has a 23-year history of endometrial stromal sarcoma (ESS). She initially underwent tumor-reductive surgery followed by adjuvant radiotherapy. The pelvic tumor recurred nearly 8 years later, obstructing the ureter and directly invading the bladder. It propagated into the vena cava as a thrombus and finally spread into the right heart chambers, leading to cardiac failure 13 years after the recurrence. The patient was treated with hormonal therapy, multiple resections of the pelvic tumor, chemoembolization, and systemic chemotherapy with doxorubicin and cyclophosphamide. She developed recurrent intractable symptoms and was started on prolonged oral etoposide therapy, which stabilized the size of the pelvic tumor and relieved her symptoms for 3 years. Her quality of life has markedly improved without significant morbidity. We review the options for treating recurrent ESS and suggest that use of prolonged oral etoposide therapy warrants further study in this setting.

Administration, Oral↗
PubMed1994

Management of tracheal and bronchial stenoses with the Gianturco stent.

Thirty-six cancer patients with symptomatic tracheobronchial stenoses received Gianturco tracheobronchial stents over a 9-year period. Symptoms improved in 28 patients (78%). The overall median survival was 1 month 3 weeks (range, 4 days to 35 months). The median survival for patients who showed improvement after receiving stents was 3 months compared with 1 week for those who did not respond. Complications were minimal. The Gianturco stent may palliate symptoms of tracheobronchial compression in selected cancer patients.

Adult↗
PubMed1990

Two chromosomal locations for human ornithine decarboxylase gene sequences and elevated expression in colorectal neoplasia.

The polyamines are known to be essential for cellular proliferation. Ornithine decarboxylase (ODC) is a rate-limiting enzyme in the synthesis of these amines, and activity is elevated in colorectal tumors and polyps. Two ODC genes (designated ODC1 and ODC2) were localized by somatic cell hybridization and in situ techniques to 2p25 and 7q31-qter, respectively. Investigation of the expression of ODC in colorectal neoplasia reveals a consistent increase in mRNA expression compared with normal adjacent mucosa and control mucosa, ranging from 1.3- to 12.2-fold. No amplification of the loci was seen. Comparison of ODC mRNA expression with ODC activity from the same samples revealed no direct correlation, suggesting that regulation of ODC in this system occurs at the posttranscriptional level.

Chromosome Mapping↗
PubMed1989

Percutaneously placed endovascular grafts for aortic aneurysms: feasibility study.

This limited study addressed the feasibility of treating aneurysms with a new transcatheter endoprosthesis. Aortic aneurysms were experimentally created in six dogs and subsequently bridged with nylon-covered, self-expanding metallic stents. The dogs were followed up for as long as 7 months (median, 22 weeks). In each dog, the graft effectively reconstituted the aortic lumen, excluding the aneurysm. One dog exhibited minimal (less than 1-mm) residual dilatation at the site of the aneurysm 7 months after graft placement. The nylon material acted as a support and template for neointimal encasement, enabling the formation of a new vascular lumen. It also remained porous at the origin of aortic side branches, preserving the visceral blood supply. One of the endovascular grafts failed to expand completely at its distal end, which promoted thrombus formation within the graft and resulted in the occlusion of both renal arteries. The dog was found comatose 48 hours after graft placement and was killed at that time.

Animals↗
PubMed1988

Self-expanding endovascular graft: an experimental study in dogs.

An arterial endovascular graft was constructed by wrapping an expandable nylon mesh around a framework of Gianturco self-expanding metallic stents. The devices were passed through a 12-French Teflon catheter and positioned in the normal abdominal aorta of five dogs, two of which also had a device placed in an external iliac artery. At follow-up (1-6 months), all grafts remained patent, even though slight luminal narrowing due to neointimal encasement was noted. Histologically, all grafts were covered by neointimal proliferation at the time of removal. The graft material expanded with the stents, resulting in a tight fit between the graft and the vessel wall. Side branches narrowed but remained open because of the size of the nylon mesh. No migration of the grafts equipped with a barbed lead stent was noted. Expandable nylon mesh can be used as an endovascular graft material when wrapped around a framework of self-expanding stents. The resulting device can be easily delivered via transcatheter techniques, and once placed in a vessel, the nylon acts as a support for neointimal encasement, which forms a new vascular lumen.

Animals↗
PubMed1987

Percutaneous endovascular graft: experimental evaluation.

An arterial endovascular graft was constructed by wrapping a Dacron cylinder around the Gianturco expandable metallic stent. The device was passed through an 11-F Teflon catheter into the normal abdominal or thoracic aortas of nine dogs. At follow-up of 7-35 weeks, all but one graft remained patent. At necropsy, the grafts were almost completely covered by neo-intimal proliferation. Similar proliferation was observed between the graft and the wall of the vessel.

Aneurysm↗
PubMed1986

Pretreatment effects on the uptake/retention kinetics of L-dopa in Harding-Passey melanoma.

Malignant melanoma cells possess a unique biochemical pathway that converts L-3,4-dihydroxyphenylalanine (L-dopa) to the biopigment melanin. Selective cytotoxic incorporation of exogenous L-dopa into melanoma cells in vivo may provide a means of designing specific chemotherapeutic agents useful in the treatment of this disease. Using the Harding-Passey murine melanotic tumor model, a preferential uptake of [3H]L-dopa by the tumor was characterized. Following pretreatment of the tumor-bearing mice with nonradioactive L-dopa, a significant enhancement (p less than 0.01) of [3H]L-dopa incorporation and retention into melanoma for a period of 24 h was observed, when compared with the concomitant tissue distribution and clearance of radioactivity in the control animals. This finding suggests that by initial pretreatment of melanoma with nonradioactive L-dopa, the subsequent selective accumulation of [3H]L-dopa in tumor may provide a useful tool in testing new modalities of therapy in malignant melanoma.

Adrenal Glands↗
PubMed1985

Postoperative respiratory complications in patients with Hodgkin's disease: relationship to the size of the mediastinal tumor.

Postoperative respiratory complications were investigated in patients with Hodgkin's disease, stages I-III, presenting with a mediastinal mass. By measuring the ratio between the widest diameter of the mediastinal mass and the width of the thorax at T5-6 (mediastinal thoracic ratio, MTR) in a PA chest X-ray, patients were divided into three groups: I: MTR less than 0.35 (41 patients); II: MTR 0.35-0.49 (33 patients); and III: MTR greater than 0.50 (23 patients). Five patients of group II and eight of group III received preoperative radiation therapy (RT) to the mediastinum due to severe clinical or radiological findings associated with the mediastinal mass. No patient of group I received preoperative RT. Without preoperative RT, group III had a significantly higher incidence of respiratory complications (7/15) compared to groups I (7/41) and II (2/28). Respiratory complications were not significantly different after preoperative RT in group III (1/8) compared to that observed in groups I plus II without preoperative RT (9/69).

Adolescent↗
PubMed1984

Hepatic artery ligation for liver metastasis in colorectal carcinoma.

From April 1975 to January 1982, 97 patients with greater than or equal to 50% of the liver involved with metastasis from colorectal carcinoma underwent hepatic artery ligation. The purpose was to evaluate median survival times in relation to performance status, synchronous intraabdominal metastasis, pulmonary metastasis, liver function tests (alkaline phosphatase, serum glutamic oxaloacetic transaminase (SGOT), lactate dehydrogenase (LDH), total bilirubin, and Dukes' staging. Results reveal that for performance status 0 to 1 (normal or symptoms, but ambulatory), median survival time was 12.3 months; status 2 to 3 (in bed less than or greater than 50% of time), 8.3 months; status 4 (100% bedridden), 2.6 months, (P less than 0.01). Median survival time in patients with only intrahepatic metastasis was 10 months versus 7 months for synchronous intraabdominal metastasis (P less than 0.01). For 20 patients with pulmonary metastasis undergoing hepatic artery ligation, the median survival time was 8.8 months (P less than 0.05). The median survival time in patients whose alkaline phosphatase was 2 times normal was 12.4 months, whereas, if alkaline phosphatase was 2 times to 4 times or greater than 4 times normal, median survival times were 7.1 and 6.9 months, respectively (P less than 0.01). Factors that adversely affect survival for hepatic artery ligation are extrahepatic metastasis, poor performance status, and elevated liver function tests (alkaline phosphatase 2 times normal). The overall median survival time in this study is 9.5 months with certain subgroups achieving 12.4 months' survival.

Adenocarcinoma↗
PubMedDate not supplied

Secretion of plasminogen activators by human colorectal and gastric tumor explants.

Conditioned media from explants of human colorectal and gastric tumors in short-term organ culture were analysed for plasminogen activator activity, activity toward the synthetic urokinase substrate, Spectrozyme-UK, and for the presence of urokinase antigen using monospecific goat antibody, by enzyme-linked immunosorbent assay. Comparisons were made between primary tumors, adjacent normal mucosa and metastatic lesions. These analyses were carried out on unfractionated culture fluids and on fractions obtained by fast protein liquid chromatography separation using Superose 6 gels. Plasminogen activator activity, tested by azocaseinolysis in the presence of added plasminogen, was restricted to peaks of 55 kD and 155 kD. These were of the urokinase type as shown by specific immunoinhibition and by absorption by an antiurokinase antibody-Affigel 10 column. Spectrozyme-UK, in addition to these peaks, detected a series of higher molecular weight activities, the largest of which appeared in the void volume, and were therefore of greater than 10(6) molecular weight. These activities were greatly increased by inclusion of trace plasmin indicating that these components were mostly in their proenzyme forms. The characteristics of these very large enzymes were similar to those isolated earlier from a human lung cancer cell line. Comparison of the primary and metastatic tumors confirmed earlier observations showing that urokinase secretion by the metastatic tumors was greatly reduced in comparison with the primary tumors: in the colon carcinomas it was 10 per cent of the value for the primary, in the gastric tumors 3 per cent, whether means or medians were compared (P less than 0.0001). This large difference was characteristic only of plasminogen activator secretion assayable by azocaseinolysis; activities toward Spectrozyme-UK, and antigen reacting with anti-urokinase antibody, were considerably less different in the two groups. In individual tissues, no correlation was found between the amount of extractable plasminogen activator and amounts secreted, or between the latter and the amount of lactic acid released. It is postulated that the greatly reduced plasminogen activator secretion by explants of metastatic tumors may be a phenotypic characteristic of distinct advantage for cancer cells destined to initiate metastatic foci, and may contribute to the ability of circulating cancer cells to lodge in the blood vessels of the target organ.

Chromatography, Liquid↗
PubMedDate not supplied

Percutaneous lymph node biopsy.

Advances in imaging modalities for detecting lymphadenopathy, the ease, safety, and accuracy of the tools and techniques, and the addition of refined ancillary studies for cytologic analysis will continue to increase the acceptance and use of percutaneous lymph node biopsy (PLNB) by fine-needle aspiration (FNA), especially in lymphomas.

Biopsy, Needle↗