Electron arc therapy of the postmastectomy prosthetic breast

PURPOSE

Reconstructive surgery of the postmastectomy breast presents new challenges to postoperative radiation therapy. This paper evaluates the dosimetric significance of oblique incidence of the electron field on the reconstructed mound during arc therapy.

METHODS AND MATERIALS

Using film densitometry, the relative dose distributions resulting from electron arc therapy incident on phantoms simulating the breast and chest wall dimensions of an actual patient are evaluated.

RESULTS

Irradiation of the breast phantom in normal supine position results in constriction of the dose distribution at the junction of the reconstructed mound with the chest wall. Angulation of the phantom to provide a more normal incidence of the electron beam during arc reduces the constriction by minimizing obliquity of the incident electrons.

CONCLUSION

These measurements suggest that, with proper positioning of the patient relative to the incident electron beam, electron arc therapy may be used as an alternative treatment technique for treatment of the postmastectomy reconstructed breast and chest wall.

Cytomegalovirus disease after heart transplantation: is acyclovir prophylaxis indicated?

To determine the efficacy of acyclovir prophylaxis in preventing cytomegalovirus (CMV) disease after heart transplantation, the clinical course of 103 patients (ages, 0.1 to 62 years; mean age, 41.8 years; 87 males, 16 females) was analyzed. Active CMV infection (defined as a positive culture from any site or a fourfold increase in immunoglobulin G antibody titers) occurred in 64% (66/103) and clinical CMV disease (defined as pathologic evidence of CMV in tissue biopsy or a typical CMV syndrome with fever and two of the following: leukopenia, thrombocytopenia, atypical lymphocytes, and elevated liver function test results in a patient with CMV infection) occurred in 25% (26/103). Independent variables studied included acyclovir prophylaxis, duration of acyclovir use, duration and type of induction therapy, donor and recipient CMV status, total steroid dose at 3 and 6 months, azathioprine dose and cyclosporine level at 3 months, age, and sex. In a multivariate regression analysis, acyclovir prophylaxis was independently associated with freedom from CMV disease (p = 0.029). Positive donor CMV status (p = 0.025), higher total steroid dose at 3 months (p = 0.036), and lower azathioprine dose at 3 months (p = 0.047) were associated with higher occurrence of CMV disease. The use of antilymphocyte induction therapy was associated with an increased occurrence of active CMV infection (p = 0.022) but not CMV disease. The prophylactic administration of acyclovir reduced the occurrence of CMV disease after heart transplantation.

Seat belt use and accident involvement: a comparison of driving behavior before and after a seat belt law

In an earlier study, researchers at the University of North Carolina Highway Safety Research Center found drivers classified as seat belt nonusers on the basis of direct observation and self-reported belt use to be overrepresented in prior accidents and violations. This study represents a follow-up and extension of the earlier study where accident and violation rates over a 2.5-year interval following the classification by seat belt use status are compared. Seat belt nonusers were again found to be overrepresented in both accidents and violations. In other analyses of these data, changes in seat belt use status were found not to be associated with changes in accident or violation rates, and seat belt use rates reported by police in accidents following the mandatory seat belt law greatly exceeded both the observed and self-reported use rates. This was especially pronounced for drivers who responded that they rarely or never used seat belts.

Amlodipine reduces graft coronary artery disease in rat heterotopic cardiac allografts

The long-acting dihydropyridine calcium antagonist, amlodipine, suppresses atherogenesis in experimental animals. To determine the effect of amlodipine on allograft coronary artery disease in the transplanted heart, we used a working heterotopic rat heart transplant model. All rats were immunosuppressed with cyclosporine as a single agent and randomized to a control group (n = 9) and an amlodipine-treated group (n = 9). After 90 days, rats were killed, and the extent of graft coronary artery disease was assessed by digitizing morphometry. No significant differences were noted for mean arterial blood pressure or serum total cholesterol, high-density lipoprotein cholesterol, or triglycerides at the time of death. Amlodipine was associated with significantly less narrowing in the coronary arteries (mean percent narrowing for control group, 48.9% +/- 8.2%; mean percent narrowing for amlodipine group, 25.5% +/- 9.9%; P < 0.05). These findings suggest a role for calcium channel blockers in the prevention of graft coronary artery disease.

Noninvasive detection of acute rejection in a new experimental model of heart transplantation

We have shown that positron emission scintigraphy detects changes in the uptake of 18-F 2-deoxyglucose and 13-N ammonia by the acutely rejecting myocardium in a nonworking model of heterotopic heart transplantation in the rat. We developed a new working model of heterotopic heart transplantation to determine the possible relevance of these changes to clinical transplantation. Moderate aortic valvular regurgitation was produced allowing the heterotopic left ventricle to fill and eject. Rejecting allografts and nonrejecting isografts (controls) were studied 4 days after transplantation. Histologically, isografts were normal and all allografts showed mild acute rejection. Decay-corrected uptakes of 18-F 2-deoxyglucose and 13-N ammonia reflect glucose metabolism and blood flow, respectively. Values are presented as percent of injected dose per gram of tissue. Uptake of 18-F 2-deoxyglucose was higher in rejecting allografts compared with nonrejecting isografts (3.0 +/- 1.8 versus 1.1 +/- 0.4; p = 0.024). Ammonia uptake was elevated in allografts compared with isografts (2.2 +/- 0.5 versus 1.3 +/- 0.5; p = 0.023). Uptakes of 18-F 2-deoxyglucose and 13-N ammonia are higher in mildly rejecting allografts, implying increased glucose utilization and blood flow during acute rejection. These data support our earlier findings of changes in myocardial metabolism in the absence of diminishing blood flow in acutely rejecting hearts. This model may lead to a better understanding of the physiology and metabolism of acute rejection.

Improved survival with neoadjuvant therapy and resection for adenocarcinoma of the esophagus

OBJECTIVE

This study sought to determine the impact of preoperative chemotherapy and radiation therapy (neoadjuvant therapy) followed by resection in patients with adenocarcinoma of the esophagus.

SUMMARY BACKGROUND DATA

Long-term survival in patients with carcinoma of the esophagus has been poor. An increase in the incidence of adenocarcinoma of the esophagus has been reported recently.

METHODS

Fifty-eight patients with biopsy-proven adenocarcinoma of the esophagus treated at this institution from January 1951 through February 1993 were studied. Since 1989, 24 patients were entered prospectively into a multimodality treatment protocol consisting of preoperative cisplatin, 5-fluorouracil (5-FU), and leucovorin with or without etoposide, and concomitant mediastinal radiation (30 Gy). Patients were re-evaluated and offered resection.

RESULTS

There were no deaths related to neoadjuvant therapy and toxicity was minimal. Before multimodality therapy was used, the operative mortality rate was 19% (3 of 16 patients). With multimodality therapy, there have been no operative deaths (0 of 23 patients). The median survival time in patients treated before multimodality therapy was 8 months and has yet to be reached for those treated with the neoadjuvant regimen (> 26 months, p < 0.0001). The actuarial survival rate at 24 months was 15% before multimodality therapy and 76% with multimodality therapy. No difference in survival was noted in neoadjuvant protocols with or without etoposide (p = 0.827).

CONCLUSIONS

Multimodality therapy with preoperative chemotherapy and radiation therapy followed by resection appears to offer a survival advantage to patients with adenocarcinoma of the esophagus.

Observed and self-reported seat belt wearing as related to prior traffic accidents and convictions

During the summer of 1987, 10,000 color-coded mailback questionnaires that identified belted and unbelted North Carolina drivers were handed out at the 72 sites that constitute the probability sample for determining the statewide belt use rate in North Carolina. By obtaining identifying information to determine the winner of a $500 prize from among the 5,074 respondents, police-reported traffic accident and conviction records from the North Carolina driver history file were linked to the belted and unbelted respondents. Analyses found that drivers who had been observed not wearing seat belts had 35% more accidents and 69% more convictions than did belted drivers in the previous four-year period. Similar findings were obtained from self-reported belt use.

Nonsanction seat belt law enforcement: a modern day tale of two cities

This paper describes the implementation and evaluation of a nonsanction seat belt law enforcement program in two experimental communities of contrasting size in a state with a mandatory belt law. The main ingredients of the program were seat belt "salutes," public information and education, and limited use of inexpensive economic incentives. Driver shoulder belt use data collected before, during, and after the experimental programs, compared to similar data collected in a comparison community, showed the approach to be effective. While standard seat belt enforcement activities without incentives have been shown to be effective, many police departments, especially in smaller communities, are reluctant to make wholesale increases in seat belt citations. Although requiring some additional level of manpower and resources, a nonsanction approach to seat belt law enforcement can provide an alternate way of increasing belt use in these communities.

Preliminary results with neoadjuvant therapy and resection for esophageal carcinoma

Between December 1988 and August 1992, 68 patients with adenocarcinoma (n = 39) and squamous carcinoma (n = 29) of the esophagus were entered prospectively in a treatment protocol to receive two cycles of cisplatin, 5-fluorouracil, etoposide, leucovorin, and 3,000 cGy of radiation to the involved esophagus and adjacent mediastinum, followed by resection. There were four deaths during chemotherapy, and 7 patients had a decline in condition or were denied operation. Fifty-six patients have come to operation, and 1 awaits resection. Twenty-two patients had transhiatal esophagectomy and 29 patients had esophagogastrostomy with a combined abdominal and right thoracic approach. Five patients did not undergo resection at operation. There was one hospital death (2%). A complete response to preoperative therapy was seen in 12 patients (21%): 5 of 20 with squamous cancer (25%) and 7 of 36 with adenocarcinoma (19%). Average follow-up is 19 months. Median survival in these patients after entrance in the protocol is 24 months. Actuarial survival at 12, 18, and 24 months is 72% (confidence limits, 66% and 78%), 53% (confidence limits, 46% and 60%), and 51% (confidence limits, 44% and 58%). Significantly better survival was associated with adenocarcinoma (p = 0.041). There is no survival advantage based on complete response to preoperative therapy. This neoadjuvant regimen is effective in patients with squamous carcinoma and adenocarcinoma. These preliminary results demonstrate an improved median and actuarial survival compared with historical controls in 137 patients operated on between 1966 and 1985 at our institution.

Third-time coronary artery bypass grafting: midterm results

Minimal data are available regarding the results of patients who have undergone myocardial revascularization more than twice. The records of 13 consecutive patients who underwent a coronary artery bypass procedure for the third time were reviewed. The indication for operation was unstable angina in all patients. All patients were placed on cardiopulmonary bypass through a median sternotomy. The mean number of bypass grafts placed at the third operation was 1.9 (range, 1 to 3 grafts). A new internal mammary artery graft was placed in 6 patients (2 had prior internal mammary artery grafts). Hospital mortality was 7.7% (1/13). The single death was due to incomplete revascularization in a patient with poor distal vessels. Three patients required intraaortic balloon pump support postoperatively, and 2 patients had prolonged ventilatory insufficiency. There have been no late deaths. The 12 survivors have been followed up a mean of 44 months (range, 6 to 90 months). Four remain asymptomatic; 5 have mild angina easily controlled with medication. All except 1 are in improved condition compared with their preoperative status. We conclude that a third myocardial revascularization can be performed with low mortality and morbidity and with the expectation of long-lasting symptomatic improvement.

Evaluation of the toxicity, pathology, and treatment of cyclohexylmethylphosphonofluoridate (CMPF) poisoning in rhesus monkeys

Cyclohexylmethylphosphonofluoridate (CMPF) is an organophosphate cholinesterase inhibitor with military significance. The purpose of these studies was 1) to determine the acute toxicity of CMPF in the male rhesus monkey, 2) to evaluate the efficacy of pyridostigmine (PYR) pretreatment plus atropine and oxime (2-PAM or H16) treatment, and 3) to evaluate the pathological consequences of acute poisoning. An i.m. LD50 of CMPF was estimated using an up-and-down dose selection procedure and 12 animals. The 48-h and 7-day LD50 was 46.6 micrograms/kg, i.m. In the protection experiments, pyridostigmine (0.3-0.7 mg/kg/24 h) was administered by surgically implanted osmotic minipumps for 3-12 days resulting in 21-65% inhibition of erythrocyte acetylcholinesterase activity. Animals were challenged with 5 x L50 CMPF (233 micrograms/kg) and treated with atropine (0.4 mg/kg) and either 2-PAM (25.7 mg/kg) or HI6 (37.8 mg/kg) at the onset of signs or 1 min after challenge. Osmotic pumps were removed within 30 min after agent challenge. Pyridostigmine, atropine, and either 2-PAM or H16 were completely effective against CMPF, saving ten of ten animals in each group. In comparison, three of five animals challenged with 5 x LD50 of soman and treated with atropine and 2-PAM survived 7 days. The primary histologic lesions in the acute toxicity group were neuronal degeneration/necrosis and spinal cord hemorrhage. The CMPF treated groups (total of 20 animals) had minimal nervous system changes with no significant lesion difference resulting from the different oxime therapies. The primary non-neural lesions were degenerative cardiomyopathy and skeletal muscle degeneration which occasionally progressed to necrosis and mineralization.(ABSTRACT TRUNCATED AT 250 WORDS)

Staging lung carcinoma with a Tc-99m labeled monoclonal antibody

Thirty-three patients with biopsy-proven lung cancer and a total of 150 lesions diagnosed by conventional staging procedures were imaged using a Tc-99m labeled monoclonal Fab fragment of an IgG2B murine monoclonal antibody (MoAb) (NR-LU-10, NeoRx Corporation). Immunoscintigraphy demonstrated 100% of primary and 78% of metastatic lesions. MoAb imaging detected 88% of lesions in 12 small cell lung cancer (SCLC) patients and 77% of lesions in 21 non-small cell lung cancer (NSCLC) patients. Based on initial evaluation by other methods, 29 sites of MoAb activity were not associated with evidence of disease. Eleven of these were subsequently shown to represent sites of metastases; 18 remain unconfirmed. Four of ten patients studied with limited NSCLC had eight unsuspected lesions on MoAb imaging. Confirmation of unsuspected lesions in two patients altered initial clinical staging, and surgical therapy was abandoned. This study demonstrates that Tc-99m labeled NR-LU-10 can accurately stage patients with lung cancer.

Noninvasive detection of heart transplant rejection with positron emission scintigraphy

Positron emission tomography has recently been used to evaluate ischemic heart disease through changes in myocardial blood flow and carbohydrate metabolism. Positron-emitting tracers were evaluated for their ability to detect acute allograft rejection after heterotopic cardiac transplantation in the rat. Sham-operated controls, nonrejecting isografts, and rejecting allografts were evaluated. Decay-corrected uptake of 13NH3 and 18F 2-fluoro 2-deoxyglucose (FDG) reflects blood flow and glucose flux, respectively. Histologic examination of rejecting allografts documented mild rejection at 4 days and severe acute rejection by 8 days. All isografts were free from rejection. Uptake of FDG is greater in rejecting allografts than in nonrejecting isografts during both severe rejection (2.4% +/- 0.8% versus 0.7% +/- 0.4%; p less than 0.02) and mild rejection (2.1% +/- 0.6% versus 0.4% +/- 0.1%; p less than 0.02). Uptake of NH3 in severely rejected grafts is reduced compared with nonrejecting grafts (0.6% +/- 0.3% versus 1.7% +/- 1.1%; p less than 0.02). There is no difference in NH3 uptake during mild rejection (1.8% +/- 0.7% versus 1.3% +/- 0.3%; p greater than 0.05). Uptake of FDG and NH3 in native hearts of animals from all experimental groups is not significantly different from that in sham-operated controls. Glucose may be a preferred metabolic substrate during rejection. Our data support a humoral mechanism for substrate preference during transplant rejection and a potential diagnostic role for positron emission tomography.

Twenty years' experience with pulmonary metastasectomy

From January 1969 through December 1989, 63 patients had 69 operations for pulmonary metastases. Patients ranged in age from 1 to 75 years; there were 36 men and 27 women. Metastasectomy was accomplished through a thoracotomy incision in 59 cases (5 staged, bilateral), and median sternotomy was used in 10 instances. Wedge resection was performed in 54 patients, with segmentectomy in 2, lobectomy in 12, and pneumonectomy in 1. There were no operative deaths. Multiple metastases were present in 29 patients, and a single metastasis in 34. Follow-up ranges from 2 to 204 months (mean = 42 months). Thirty-eight patients remain alive; thirty are free of disease and eight have developed other metastases. Actuarial survival at 5, 10, and 15 years is 40 (CL [confidence limits] 49,31), 36 (CL 44,26), and 24 (CL 35,13) per cent, respectively. Mean actuarial survival is 84 months, and median survival is 58 months. There is no difference in survival whether metastases were single or multiple. Survival is significantly less in groups with primary sarcoma and melanoma (P = .012). While pulmonary metastases may be a manifestation of terminal disease, metastasectomy has an important role in the multidisciplinary management of selected patients when metastatic disease is confined to the lung. Prolonged survival may be achieved in many patients.

Efficacy of oxime plus atropine treatment against soman poisoning in the atropinesterase-free rabbit

The oximes pralidoxime chloride (2-PAM), MMB4, and HI-6 were evaluated in combination with atropine as treatments against soman poisoning in atropinesterase-free rabbits. Animals were challenged i.m. with 2 x LD50 soman and treated at the onset of toxic signs with 50 mumols/kg of oxime and 5 or 13 mg/kg atropine. Survival and time to death were compared at 48 hours post-soman challenge. Survival rates in MMB4 and HI-6 treated animals were higher than in 2-PAM-treated animals. The increase in survival was significant at the 13 mg/kg dose of atropine. MMB4 and HI-6 also significantly delayed time to death after soman compared to 2-PAM. The results suggest that MMB4 and HI-6 have potential as useful oximes for treating soman poisoning.

Reduction by pyridostigmine pretreatment of the efficacy of atropine and 2-PAM treatment of sarin and VX poisoning in rodents

This study concerned the effect of pyridostigmine pretreatment on (a) the antidotal efficacy of atropine and 2-PAM in sarin, tabun, and VX poisoning in mice and guinea pigs and on (b) the oxime-induced reactivation of VX-inhibited whole blood acetylcholinesterase (AChE) of guinea pigs. One hour prior to organophosphate (OP) challenge with sarin, tabun, or VX, animals were given oral doses of pyridostigmine to induce approximately 30 and 60% inhibition of whole blood AChE; controls received vehicle. Mice were challenged im and guinea pigs sc with the OP compounds. Treatment with atropine (11.2 mg/kg to mice; 32 mg/kg to guinea pigs) plus 2-PAM (25 mg/kg) was given im at 10 sec postchallenge in mice and 1 min postchallenge in guinea pigs. In the reactivation experiments, pyridostigmine or saline was given im to guinea pigs 30 min prior to VX (8.24 micrograms/kg, sc), atropine (16 mg/kg) was given im at 1 min, and 2-PAM (25 mg/kg) at 16 min postchallenge. Pyridostigmine significantly enhanced the efficacy of atropine and 2-PAM against tabun in both species. In contrast, pyridostigmine reduced or did not increase the efficacy of atropine and 2-PAM against sarin or VX in both species. Recovery of VX-inhibited AChE by 2-PAM was decreased significantly in pyridostigmine pretreated animals. The results suggest that pyridostigmine pretreatment may adversely effect the efficacy of atropine and 2-PAM as antidotes for VX and sarin intoxication.

Operational evaluation of three commercial configurations of atropine/HI-6 wet/dry autoinjectors

Commercially manufactured wet/dry autoinjectors containing atropine in solution and powdered HI-6 were evaluated using HPLC for consistency of drug delivery with various solvation times and stability of drugs postsolvation at a temperature of 40 degrees C. Three configurations of autoinjector were tested. System A (SYS A), with a specified mixing time of 5 sec, delivered a volume of 3.0 ml containing 1.86 mg of atropine sulfate and 443 mg of the bispyridinium oxime HI-6 dichloride. System B1 (SYS B1) and System B2 (SYS B2), with specified mixing times of 40 sec, delivered volumes of 2.3 ml containing 2.13 and 2.06 mg atropine citrate and 424 and 545 mg HI-6 dichloride, respectively. Average coefficients of variation for SYS A were 3.4% for atropine and 5.8% for HI-6 and for SYS B1 and B2 were 5.2% for atropine and 7.0% for HI-6 determinations. Stored from 3 to 14 days at 40 degrees C after the autoinjector contents were mixed, SYS A delivered 1.77 mg atropine sulfate and SYS B1 and B2 delivered 2.02 mg atropine citrate. The delivery of HI-6 dichloride decreased with a half-life of 34 days for SYS A, 39 days for SYS B1, and 32 days for SYS B2. This resulted in a decrease to 90% of the respective day 0 amount after 4 (SYS A) or 5 (SYS B1 or B2) days.

Dose volume histogram analysis of lung radiation from chest wall treatment: comparison of electron arc and tangential photon beam techniques

The technique of electron arc irradiation of the post-mastectomy chest wall was developed to improve dose uniformity and to reduce lung irradiation in comparison to that seen with standard chest wall tangent photon beam methods. Because of the cephalocaudal variation in chest wall shape and thickness, electron arc treatment planning requires anatomical detail provided by multiple axial CT images of the thorax. To compare the fixed beam and rotational techniques, computer simulated beams covering the chest wall and internal mammary lymphatics were retrospectively applied to the CT-derived contours obtained during treatment planning for 12 consecutive patients receiving adjuvant chest wall treatment by electron arc. The lung dose distribution for each technique was calculated using heterogeneity corrections. The multiplanar 2-dimensional isodose distributions were summed to provide estimated 3-dimensional dose distributions of integral histograms. These reveal that for most of these patients a modest to large improvement in volume-dose relationship occurs with the electron arc technique.

Cavoatrial tumor thrombectomy using cardiopulmonary bypass without circulatory arrest

Of 29 patients with inferior vena caval tumor thrombus, 14 with supradiaphragmatic extension were deemed suitable for operation. Patients (age, 7.5 to 70 years) had renal cell carcinoma (n = 8), Wilms' tumor (n = 2), transitional cell carcinoma (n = 1), and adrenal carcinoma (n = 3). Seven patients had stage III disease, and 7 patients had stage IV disease. Two patients (group A) had unresectable disease at exploratory celiotomy, 4 patients (group B) underwent tumor thrombectomy without cardiopulmonary bypass, and cardiopulmonary bypass was employed in 8 patients (group C). Three of 8 group C patients had Budd-Chiari syndrome at diagnosis. Cardiopulmonary bypass with moderate hypothermia, and inferior vena caval interruption (clip or filter), was employed in all patients. There were no perioperative deaths. Transient neurological impairment was observed postoperatively in 2 patients. Coagulopathy developed in 1 patient who had hepatic encephalopathy and Budd-Chiari syndrome preoperatively and in another patient in whom protamine could not be administered. No patient had acute renal failure requiring hemodialysis. Median survival is 41 and 17 months in groups B and C, respectively. Some authors have advocated profound hypothermia and circulatory arrest in these patients. We find that satisfactory visualization and excision can be performed with cardiopulmonary bypass and moderate hypothermia, avoiding potential renal, hepatic, neurological, and septic complications associated with circulatory arrest.

Heart transplantation in children

Orthotopic cardiac transplantation has been performed in 15 consecutive neonates and children since 1987. Diagnoses include hypoplastic left heart syndrome (5 patients), critical aortic stenosis with small left ventricle (1 patient), complex cyanotic heart disease (6 patients), and cardiomyopathy (3 patients). Twelve patients survived operation and have been followed from 1 to 45 months. Patients less than 6 years of age are managed with cyclosporine +/- azathioprine; in older patients steroid weaning is attempted. Monitoring for rejection is performed with serial echocardiography in patients under 6 years of age; older patients undergo serial biopsies. Actuarial freedom from rejection was 26% 3 months after operation; 47% were free of infection 6 months after operation. There have been no late deaths. Actuarial survival at 3 years is 79%. Nine patients have undergone postoperative catheterization. Resting hemodynamics were normal in every patient. All long-term survivors are asymptomatic and fully active. It is concluded that cardiac transplantation in neonates and children is an effective treatment option for end-stage cardiomyopathy or otherwise incurable congenital heart disease. Long-term survivors have excellent potential for full rehabilitation.

Pharmacokinetics and pharmacodynamics of oximes in unanesthetized pigs

The pharmacokinetics and cardiovascular pharmacodynamics of two oximes were studied in unanesthetized pigs. Effects of 2-[(hydroxyimino)methyl]-1-methylpyridinium chloride (pralidoxime chloride; 2-PAM Cl; 50 mumol/kg) were compared with those of 1,1-methylene bis[4(hydroxyiminomethyl) pyridinium] dichloride (methoxime; MMB-4; 100 mumol/kg). Cardiopulmonary parameters were monitored and plasma concentrations of oximes were determined from arterial blood samples taken at intervals over a period of 5 hr postinjection. Plasma concentrations for both oximes were fitted to standard pharmacokinetic models using the computer program PCNONLIN. Average pharmacokinetic parameters were determined for each oxime. Only mild to moderate physiological side effects were detected following intramuscular administration. 2-PAM Cl was more rapidly absorbed and distributed in the blood than MMB-4. Although the latter had a slight lag time to attain detectable levels in the blood, retention time was longer than that of 2-PAM Cl.

An unusual appearance of an aneurysmal bone cyst of the thoracic spine

Aneurysmal bone cysts (ABCs) have been reported in essentially every bone of the human skeleton. This case report documents a very unusual clinical appearance for this entity: a superior mediastinal mass. Also, the patient underwent multiple imaging studies that demonstrated both common (absence of septations) and unusual (extensive involvement of vertebral body with little involvement of posterior elements) characteristics of ABCs.

Management of primary nonrenal parenchymal malignancies with vena caval thrombus

We report our experience with the management of 7 primary nonrenal parenchymal malignancies with vena caval tumor thrombus. Included are 3 cases of adrenal cortical carcinoma and 1 each of transitional cell carcinoma, embryonal cell testicular carcinoma, pheochromocytoma and primary small cell carcinoma of the lung with metastases to the kidney. Surgical treatment and followup are presented, as well as a review of the literature. An aggressive surgical approach is warranted because prolonged survivals free of disease are possible.