Background. Dedifferentiated chordoma is an unusual and aggressive variant of chordoma which is likely to metastasize. Few reports exist of treatment of these tumors with chemotherapy.
Methods. In 1988, two patients with dedifferentiated sacral chordomas were seen at the University of Chicago Hospitals. Both developed metastatic disease less than a year after sacral resection and radiation therapy. These patients' diagnoses, courses, and treatments were reviewed along with the literature on chemotherapy in both conventional and dedifferentiated chordomas.
Results. Both patients obtained complete remissions, one to a six‐drug regimen and the other to ifosfamide.
Conclusions. A trial of reasonably aggressive chemotherapy is warranted in patients with metastatic dedifferentiated chordoma. The optimum regimen is unclear, but agents active in high‐grade sarcomas are logical choices.
Hyperlipidemia poses a risk for cardiovascular disease in both hemodialysis and renal transplantation patients. Although lipid profiles differ between the 2 populations, we evaluated the possibility that both groups have similar abnormalities of lipoprotein(a) [Lp(a)]. Mean serum Lp(a) and standard error of the mean (SEM) in hemodialysis and transplant recipients was 16.6 ± 4.7 and 18.3 ± 3.6 mg/dl, respectively, compared with 10.7 ± 4.1 mg/ dl in healthy controls, p < 0.05. That serum Lp(a) levels are significantly elevated in dialysis and renal transplantation patients suggests at least 1 common pathogenic mechanism for the high incidence of atherosclerosis in both groups.
Digoxin-like immunoreactive substances (DLIS) are present in patients with conditions associated with volume expansion (including hypervolemic hypertension, renal failure, and liver failure) and in pre-eclampsia and premature birth. These strongly-protein-bound substances cross-react with anti-digoxin antibodies and cause falsely increased measured concentrations of digoxin in serum. Patients with congestive heart failure (CHF) often have volume expansion and are receiving digoxin therapy. They are also very sensitive to digoxin toxicity and have a very narrow therapeutic range (1.0-1.9 nmol/L). We found monitoring the concentrations of free digoxin (in protein-free ultrafiltrates) helpful in eliminating the interferences of DLIS in CHF patients. DLIS concentrations were measured by fluorescence polarization assay. Concentrations of DLIS were detectable in significantly more (58.3%) of the 12 CHF patients (group A) who were not receiving digoxin than in the 22 normal volunteers tested (13.6%) (P less than 0.05 by both chi-square and Fisher's exact test). Protein-free filtrates from patients or normal volunteers did not show any measurable DLIS activities. We also determined the concentrations of total and free digoxin in 12 patients with CHF who were receiving digoxin (group B) and compared the results with those for 22 patients receiving digoxin without the diagnosis of CHF or any known pathological conditions that could increase DLIS concentrations. The ratio of free to total digoxin in patients in group B was significantly lower (mean = 52.8%, SD 10.2%) than in those receiving digoxin (mean = 72.7%, SD 6.5%) for other reasons (independent two-tailed t-test, P less than 0.05).
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