Malignant salivary gland tumors of the base of the tongue.

We present a 41-year retrospective study of patients with malignant salivary gland tumors of the base of the tongue treated at The University of Texas M. D. Anderson Hospital and Tumor Institute at Houston. This report characterized the patient group, documents their physical findings, analyzes survival, and draws some conclusions regarding clinical course and treatment options. When feasible, surgical resection is the preferred treatment, with planned postoperative radiotherapy when indicated by pathologic findings.

Posttraumatic vertebral artery aneurysm and arteriovenous fistula: a case report.

A case of posttraumatic vertebral artery aneurysm and arteriovenous fistula in a 32-year-old man is presented. Embolization of the vertebral artery was accomplished with occluding spring emboli, producing entrapment of the vascular injury. A discussion of this treatment modality is presented.

Analysis of the growth kinetics of a human lymphoma cell line.

The growth kinetics of an established human lymphoma cell line were analyzed by a variety of techniques utilizing various cell inocula (5 X 10(4)--5 X 10(5) cells) dispensed into 60 mm diameter dishes. Techniques included pulse-labeled mitosis (PLM), continuous labeling with 3H-TdR, time-lapse photography (TLP), cell counts by electronic particle counter, and DNA histography obtained by pulse cytophotometry (PCP). There were no significant differences among values determined for any kinetic parameters as a function of cell concentration. The average doubling time of exponentially growing cells, regardless of cell inoculum, was 44.1 hr. The generation time determined by PLM was 31.1 hr with a SD of 4.7 hrs. Transit times for each stage were: TG1 = 10.6 hr, TS = 9.9 hr, TG2 = 9.9 hr, and TM = 0.7 hr. Repeated experiments using continuous labeling with 3H-TdR demonstrated a TG2 of 6.3 hr. The longer value determined by PLM is possibly due to the technical manipulations of this procedure which may delay pulse-labeled cells from resuming cell cycle transit. Hence, values for cell cycle stages were recalculated to give TG1 = 14.1 hr, TS = 9.9 hr, TG2 = 6.3 hr, and TM = 0.7 hr. These results were used to compute the size of each cell cycle stage compartment pool and corresponded very closely to values defined directly by PCP. TLP analysis considered only cells that produced colonies of at least thirty-two cells. Generation times ranged from 8 to 89 hr and showed a positive skewness. The average value measured for 330 divisions was 34.5 hr with a SD of 13.2 hr. Thus, the variance predicted by curve fitting of the PLM data did not correlate with that defined by time-lapse photography nor did it encompass the range in generation times observed directly by TLP. There was a positive correlation between sister-sister cell generation times (+0.66) but no relation was noted for mother-daughter values.

Comparison of in vitro methods to determine drug-induced cell lethality.

In proliferating cell populations, the inability to reproduce indefinitely is the only relevant criterion to assess cell lethality. The in vitro colony formation technique (CF) used to determine reproductive death is, however, too slow and has several technical limitations. For finding suitable, more rapid techniques that assessed drug-induced cell killing, a human lymphoma cell line was exposed in vitro to increasing concentrations of adriamycin, bleomycin, and 1,3-bis(2-chloroethyl)-1-nitrosourea for 1 hr. Survival was assayed immediately after treatment and at regular intervals thereafter. Data from CF were compared to those resulting from the following tests: doubling time, labeling index, dye exclusion, 51Cr release, and rate of [3H]thymidine uptake (scintillation index). Dye exclusion and 51Cr release failed to demonstrate any killing effect for the 3 drugs. The percentage of killing calculated from doubling time determinations, although dose dependent, failed to correlate with CF. Scintillation and labeling index values displayed similar temporal fluctuations but were not clearly dose dependent and did not correlate with CF. Thus, CF appears as the most reliable, dose-dependent index of cell lethality. Tests that measure metabolic death grossly overestimate or underestimate killing activity induced by 3 of the most effective antitumor drugs.