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Biomedical subjects

S Wallace

Publications and source records attributed to S Wallace.

At least 271 records · Page 15Linked to original sources
PubMed1985

Control of primary osteosarcoma with chemotherapy.

High-dose methotrexate with citrovorum factor "rescue" (MTX-CF) produced an apparent complete response of the primary tumor in three patients with osteosarcoma. The response was sustained with MTX-CF, intra-arterial cis-diamminedichloroplatinum II (CDP) and Adriamycin (doxorubicin) for 18 months. Treatment was then electively discontinued. Local recurrence occurred in two patients, 6 and 4 months later, respectively. MTX-CF was reinstated and a complete response was again achieved in one patient. This has been maintained for 15+ months with MTX-CF and intra-arterial CDP administered for 13 of the 15+ months. Reinduction with MTX-CF failed in the second relapsed patient but an apparent remission was again achieved with radiation and intra-arterial CDP. This has been maintained with intravenous CDP, cyclophosphamide and phenylalanine mustard for 14+ months. A complete response in the primary tumor was still present in the nonrelapsed patient, 42 months from diagnosis. All patients have remained free of pulmonary metastases, 40+ to 42+ months from diagnosis.

Adolescent↗
PubMed1985

Arterial infusion of dacarbazine and cisplatin for recurrent regionally confined melanoma.

We treated nine patients who had metastatic malignant melanoma confined to one extremity (8/9) or the vulva (1/9) with arterial dacarbazine and cisplatin at respective doses of 800 and 90 mg/sq m. We percutaneously introduced catheters into the extremity or regional artery under fluoroscopy by the Seldinger technique, removed them at the end of the infusions, and repositioned them at four-week intervals for repeated treatment cycles. One patient achieved a complete remission, three patients had partial remissions, and five patients' disease was stable. The group median survival will exceed 19 months. Three patients with stable disease died 6, 18, and 19 months after treatment initiation, respectively. The toxic effects were primarily nausea and vomiting, pain in the infused extremity, and local erythema. Arterial dacarbazine and cisplatin offer a more effective and less toxic alternative to higher-dose single-agent arterial cisplatin for locally advanced malignant melanoma.

Adult↗
PubMed1985

Discriminative stimulus properties of valproic acid in the pigeon.

Pigeons were successfully trained to discriminate 60 mg/kg valproic acid from saline using a two-key drug discrimination procedure. When 5-80 mg/kg doses of valproic acid were administered during generalization tests the percentage of responses directed to the valproic acid-appropriate key varied directly with dose. The effects of administering the training dose of valproic acid at presession injection intervals ranging from 15 to 120 min were described by an inverted U-shaped function; the 30-min interval used during discrimination training engendered the largest percentage of valproic acid-appropriate responses. The discriminative stimulus properties of valproic acid failed to generalize to the anticonvulsant compounds phenobarbital (10, 20 mg/kg), phenytoin (2.5, 5 mg/kg), and ethosuximide (40, 80 mg/kg), indicating that not all anticonvulsant compounds share similar discriminative properties. Clonazepam (0.25, 0.50 mg/kg) and diazepam (1, 2 mg/kg), two benzodiazepines with anticonvulsant properties, produced quite different effects. The stimulus properties of valproic acid generalized to all doses of clonazepam, whereas intermediate generalization was evident with diazepam. Pentylenetetrazol (10, 20 mg/kg), chlorpromazine (5, 10 mg/kg), tripelennamine (2.5, 5.0 mg/kg), d-amphetamine (0.5, 1.0 mg/kg), morphine (1.25, 2.50 mg/kg), and imipramine (2.5, 5.0 mg/kg) induced only saline-like patterns of responding. The concomitant administration of pentylenetetrazol failed to antagonize the discriminative stimulus properties exerted by the training dose of valproic acid.

Animals↗
PubMed1985

Transcatheter thrombolysis in cancer patients.

Arterial thrombolysis was successfully accomplished in 15 of 18 (83%) cancer patients by the continuous intraarterial transcatheter administration of streptokinase (70 units/kg/h or 5000 u/h and/or urokinase (400-500 u/kg/h) over 24-96 h. In 16 of these patients, the arterial thrombosis was a complication of transcatheter infusion of chemotherapeutic agents or embolization therapy. A combination of streptokinase, urokinase and heparin (10,000-25,000 U/day) was utilized without significant side effect and was effective in all 8 patients receiving treatment. Creating a tunnel through the clot, daily monitoring of the catheter with repositioning when necessary, and adjusting the type and dose of thrombolytic agent aided the therapeutic management.

Adolescent↗
PubMed1985

Transcatheter infusion of 99mTc MAA for predicting response of intra-arterial chemotherapy in osteogenic sarcoma.

Ten patients with histologically proven osteogenic sarcoma received multiple courses of intra-arterial chemotherapy. Patients received 2-3 mCi 99mTc macroaggregated albumin (MAA) infused through indwelling arterial catheters prior to, during and after the chemotherapy, and static images of tumor beds and lungs were taken and compared with contrast angiographic findings. Of the 31 studies to evaluate tumor vascularity, 26 agreed and five showed discrepancies. In general, decreased tumor vascularity, as represented by reduced MAA uptake by the tumor, corresponded to decreased tumor size and to increased tumor calcification seen on radiographs. Twenty-six of the 31 lung-imaging studies also revealed agreement between decreasing tumor vascularity, based on decreasing MAA tumor uptake, and decreasing lung uptake of the radioactivity. Decreased lung uptake of the activity on the last follow-up study in eight patients corresponded to reduced tumor involvement and improved patient performance status.

Adolescent↗
PubMed1985

Selective occlusion and focal hyperthermia therapy of V-2 tumors in the rabbit hindlimb.

Utilizing technology recently developed in our laboratory, hypervascular, heat-resistant V-2 tumors growing in the rabbit hindlimb were variously subjected to selective vascular occlusion by embolization with Dextran M microspheres and focal hyperthermia to minimum intratumor temperatures of 43 degrees C X 40 minutes (OH), focal 43 degrees C X 40 minutes hyperthermia alone (H), selective occlusion plus sham hyperthermia (O), and sham treatment. Regional toxicity observed consisted of skin burns and muscle fibrosis in the H and OH groups and peripheral embolization in the O alone group. Tumors subjected to a single OH treatment had significantly reduced growth rate over a 28-day period of observation compared with all other treatment groups and sham-treated controls (P less than or equal to .05). Our findings suggest that the combination of selective vascular embolization and focused hyperthermia may be useful in therapy of hypervascular, heat-resistant human tumors in anatomic locations where selective occlusion and relatively intense focal heating can be performed. The regional toxicity encountered in this model reemphasizes the need for extensive thermal mapping over the heated region.

Animals↗
PubMed1985

Medulloblastoma in infants and children: computed tomographic follow-up after treatment.

Thirty-six proven cases of medulloblastoma were reviewed by serial CT follow-up examinations from 4 months to 10 years, 2 months after the initial diagnosis, with a mean follow-up time of 3 years, 9 months. The children ranged in age from 10 months to 16 years, 7 months at the time of follow-up. The tumor recurred at the primary site in 20 cases (56%). Leptomeningeal metastasis was demonstrated on CT in 14 cases (39%); seven of these patients also presented with solid subarachnoid metastases. Thirteen patients (36%) showed evidence of severe brain atrophy, which was confined to the posterior fossa in seven of the 13. Calcification resulting from mineralizing microangiopathy developed in five cases (14%), including three patients who had extensive dystrophic calcification in the corticomedullary junction and the deep-seated nuclei of the cerebrum and cerebellum. Only one case of leukoencephalopathy was observed. The patterns of tumor recurrence in the posterior fossa that is severely deformed by surgery and other treatment modalities and leptomeningeal spread of tumor are discussed.

Adolescent↗
PubMed1985

Gluteal artery occlusion: intra-arterial chemotherapy of pelvic neoplasms.

Intra-arterial chemotherapy of pelvic tumors may be complicated by coincident flow to the buttocks. Transcatheter occlusion of both the superior and inferior gluteal arteries may have a role in directing the flow of chemotherapeutic agents away from the buttocks and toward the true pelvis. The results of flow studies using technetium-99m-labeled macroaggregated human serum albumin were compared in 12 consecutive patients examined before and after transcatheter arterial occlusion, and the best results were obtained by selective occlusion of those arteries that demonstrated increased flow to the buttock on the initial study. Without the preselection of patients in whom the initial flow went mainly to the buttock, the results were inconsistent. Because of the increase in the procedure time and the occurrence of minor complications, such as local pain during or after the occlusion procedure, in all patients, proper patient selection is important.

Adult↗
PubMed1985

Supraclinoid intracarotid chemotherapy using a flow-directed soft-tipped catheter.

In an attempt to avoid toxic reactions of the eye as a complication of internal carotid arterial infusion of cisplatin, carmustine, or a combination of both for the treatment of brain tumors, a new Gore-Tex/Teflon coaxial catheter system has been used for supraclinoid placement. Catheter placement was successful in 14 of 16 attempts in eight patients. Two patients experienced eye pain and conjunctivitis--a result of the chemotherapeutic agent leaking through the Gore-Tex portion of the catheter at the infusion rate of 170 ml/h. No complications were noted as long as the infusion rate was maintained at 125 ml/h or lower.

Adult↗
PubMed1985

Percutaneous endovascular stents: an experimental evaluation.

Percutaneous, expanding, endovascular stents were constructed of stainless steel wire formed in a zig-zag pattern. Stents were placed for varying periods of time in the jugular vein, vena cava, and abdominal aorta in each of five adult dogs. The dilating force of the stents could be controlled by different wire size, number and angle of wire bends, and stent length. In addition, multiple stents could be placed one inside the other or one after the other, depending on the circumstance. The stents distended the vessels and increased their diameter. No flow defects, luminal narrowing, or occlusion were noted in any of the stented vessels, even after 6 months. Side branches bridged by the stents remained patent and showed no indication of narrowing. Stent wires became encased by a proliferation of the tunica intima where they contacted the vessel wall. Encasement was slower and less extensive in the abdominal aorta. No vascular erosion or clot formation was found to be associated with any of the stents.

Animals↗
PubMed1985

Endovascular stent for use in aortic dissection: an in vitro experiment.

Injection of normal saline and contrast material into the walls of aortic specimens from human cadavers created a narrowing of the aortic lumen, simulating aortic dissection. Endovascular stents were applied to expand the aortic lumen. Successful dilatation of the narrowed aortic lumen was demonstrated in all six specimens.

Aortic Dissection↗
PubMed1985

Treatment of the rabbit V-2 carcinoma with intralesional cisplatin.

New Zealand white rabbits were used in the evaluation of intralesional injections of cisplatin for the management of experimentally induced V-2 carcinomas. The tumors were implanted into the right hip by intramuscular injections of an inoculum containing freshly harvested V-2 fragments which gave rise to a single, spherical mass (2-3 cm) 2 weeks after inoculation. All rabbits received two courses of either intralesional cisplatin or saline beginning 2 weeks after inoculation. Cisplatin injections significantly slowed the growth and spread of the primary tumor in all treated rabbits. In addition, intralesional chemotherapy prevented the development of lung metastases in 71% of the animals and produced approximately a threefold increase in survival time. Results indicate that not only is cisplatin active against experimentally induced V-2 carcinomas in rabbits, but direct intralesional injection is also an easy and effective means of administering chemotherapy.

Animals↗
PubMed1985

Comparison of intra-arterial cis-diamminedichloroplatinum II with high-dose methotrexate and citrovorum factor rescue in the treatment of primary osteosarcoma.

A randomized two-arm study was undertaken to determine relative tumoricidal effects of intra-arterial cis-diamminedichloroplatinum II (I/A-CDP) and high-dose methotrexate with citrovorum factor rescue (MTX-CF) in the treatment of the primary tumor in patients with osteosarcoma. Responses were evaluated by clinical, radiographic, angiographic, and pathologic parameters. Fifteen patients were randomized to receive MTX-CF and 15 to I/A-CDP. In the MTX-CF arm there were four responses (three complete responses, one partial response) whereas in the I/A CDP arm there were nine responses (seven complete responses, two partial responses). Two patients who failed MTX-CF and requested alternative treatment with I/A-CDP also responded. The total I/A-CDP response was 11/17.

Adolescent↗
PubMed1985

Referrals by traditional birth attendants in northeast Brazil.

Between October 1980 and July 1981, 1,878 women were attended by traditional birth attendants (TBAs) at four obstetric units in rural areas surrounding the city of Fortaleza in Northeast Brazil. Of these women, 232 (12.4 per cent) were referred to a hospital in Fortaleza for delivery. The most important indicators for referral to hospital were: presence of an antenatal problem, complication of labor, or malpresentation. Based on record review, 65 referred women with none of these conditions were classified as low risk and 42 women not referred were classified as high risk (at least one such condition present). Of 1,878 deliveries, 32 (17 per 1,000) terminated as fetal deaths, and 12 infants died before discharge from hospital or obstetric unit (six per 1,000). The death rate was much higher for the high-risk cases (156 per 1,000 referrals, 95 for nonreferrals). Although some women may have been inappropriately referred while others who should have been were not referred, the system of referral has allowed TBAs to attend uncomplicated deliveries and to refer women with complications.

Adolescent↗
PubMed1985

Computed tomography of osteosarcoma after intraarterial chemotherapy.

The response to intraarterial cis-diamminedichloroplatinum II (CDP) chemotherapy was evaluated by computed tomography (CT) in 33 patients with pathologically proved osteosarcoma of the long or flat bones. Twenty-one of the 33 patients had a CT scan before chemotherapy was started. In the other 12 patients, a CT scan was obtained after at least two courses of treatment, and additional studies were performed during the course of therapy. In those patients responding to treatment, the posttherapy scan revealed a remarkable decrease or complete disappearance of the associated soft-tissue mass and clear reestablishment of the fat planes between the muscle bundles that had been obscured. There was sharp definition of the peripheral margins of the calcified healing neoplasm, and the calcification in the healing tumor could be differentiated easily from that of the original bone neoplasm. The findings of CT were compared with those of conventional studies and pathologic results. CT was more accurate than conventional studies in detecting healing process and diagnosis of remission.

Adolescent↗
PubMed1985

Myelography in cancer patients: modified technique.

Because of the frequency of multiple sites of involvement, a thorough evaluation of the entire spinal canal is essential for detection and treatment of spinal compression in cancer patients. For the examination of the entire spinal canal in cancer patients, a modified approach is described using water-soluble contrast medium (metrizamide), oil-based material (Pantopaque), and a "squeezing" technique for a complete myelographic block. Of 240 patients who underwent myelography for possible spinal compression, the squeezing technique was applied through a lumbar puncture to demonstrate a complete block in 39 patients; six of these had more than one block. Of the other 201 patients, the quality of the myelograms was satisfactory or excellent in 189 (94%).

Adolescent↗