The Transfer of Polystyrene Microspheres from the Gastrointestinal Tract to the Circulation after Oral Administration in the Rat

Factors relating to the transfer of latex microspheres of 0·87 μm mean diameter from the gastrointestinal tract (GIT) to the circulation have been investigated. The rapidity of appearance and the number of particles increased when the volume of water used as a suspending vehicle was increased. This was probably due to barrier cell integrity being compromised so that the movement of particles across the enterocytes would be enhanced. Particles were swept into these channels by the waterflow. The tonicity of the fluid was important as isotonic and hypertonic saline were not as affective as water in transferring particles. Particles were transferred from GIT segments adjacent to the stomach which may in part explain the rapid appearance of particles in the circulation. Particle uptake was blocked by cytochalasin B which suggests an active component may also be involved.     

Copper radionuclides and radiopharmaceuticals in nuclear medicine

The chemistry, radiochemistry, radiobiology, and radiopharmacology of radiopharmaceuticals containing copper radionuclides are reviewed. Copper radionuclides offer application in positron emission tomography, targeted radiotherapy, and single photon imaging. The chemistry of copper is relatively simple and well-suited to radiopharmaceutical application. Current radiopharmaceuticals include biomolecules labelled via bifunctional chelators primarily based on cyclic polyaminocarboxylates and polyamines, and pyruvaldehyde-bis(N⁴-methylthiosemicarbazone) (PTSM) and its analogues. The chemistry of copper, of which only a fraction has yet been exploited, is likely to be applied more fully in the future.     

Complications of endodrainage retinotomies created during vitreous surgery for complicated retinal detachment

The authors report nine cases of endodrainage retinotomy site complications that occurred after vitreous surgery for complicated retinal detachments (RDs). Postoperative subretinal neovascularization developed in four eyes at the retinotomy drainage site. In two eyes, postoperative proliferation at a posteriorly placed endodrainage site created traction macular detachments. Redetachment due to retinotomy opening caused by postoperative drainage site proliferation developed in three eyes. The retinas of all nine eyes were eventually reattached, and vision improved from the preoperative level. These complications are related to retinal pigment epithelium and/or Bruch's membrane damage during internal subretinal fluid drainage and retinotomy endolaser photocoagulation. Careful evaluation of extrusion instruments, drainage techniques, retinotomy placement, and subsequent endolaser treatment is necessary to minimize these complications.     

The role of surgery in the management of gestational trophoblastic disease

Between November 1967 and December 1994, 242 patients with gestational trophoblastic disease (GTD) were treated with chemotherapy by the Gynecology Service of Memorial Hospital. Eighty-seven of the patients (35.9%) underwent at least one major operation during the course of their illness. Twenty-six patients underwent two major operations, and in five patients, three major operations were performed, for a total of 118 procedures. The most frequent procedures were: hysterectomy, 56 (47.4%); hysterotomy, 15 (12.7%); thoracotomy, 13 (11%); and craniotomy, 5 (4.2%). Twenty-nine additional procedures ranging in complexity from oophorectomy to segmental liver resection were also performed. Twenty-nine operations (24.5%) were considered to be beyond the scope of most gynecologic surgeons. The overall complete remission rate for 242 patients was 90.4%. The rate for patients who underwent a major surgical procedure was 79.3% compared to 96.7% for patients whose treatment was with chemotherapy alone.
The data demonstrate that the integration of surgery in the management of GTD patients often requires a multidisciplinary approach that in many cases can best be achieved at specialized treatment centers.     

Retroperitoneal soft-tissue sarcoma: analysis of 500 patients treated and followed at a single institution.

OBJECTIVE: To analyze treatment and survival of a large cohort of patients with retroperitoneal soft-tissue sarcomas (STS) treated and prospectively followed at a single institution. SUMMARY BACKGROUND DATA: Retroperitoneal STS are relatively uncommon and constitute a difficult management problem. Although surgical resection is often difficult or impossible, current chemotherapy is not effective and radiation is limited by toxicity to adjacent structures. Thus, complete surgical resection remains the most effective modality for selected primary and recurrent disease. METHODS: Five hundred patients with retroperitoneal STS were admitted and treated between July 1, 1982, and September 30, 1997, and prospectively followed. Patient, tumor, and treatment variables were analyzed for disease-specific and disease-free survival. Survival was determined with the Kaplan-Meier method. Statistical significance was evaluated using the logrank test for univariate influence and Cox model stepwise regression for multivariate influence. RESULTS: Two hundred seventy-eight patients (56%) had primary disease and 222 (44%) recurrent disease. Median follow-up was 28 months (range 1 to 172 months), 40 months for survivors. Median survival was 72 months for patients with primary disease, 28 months for those with local recurrence, and 10 months for those with metastasis. For patients with primary or locally recurrent tumors, unresectable disease, incomplete resection, and high-grade tumors significantly reduced survival time. CONCLUSIONS: In this study of patients with retroperitoneal STS, stage at presentation, high histologic grade, unresectable primary tumor, and positive gross margin are strongly associated with the tumor mortality rate. Patients approached with curative intent should undergo aggressive attempts at complete surgical resection. Incomplete resection should be undertaken only for symptom relief.