Nasopharyngeal carcinoma with intracranial spread: CT and MR characteristics

PURPOSE: Nasopharyngeal carcinoma (NPC) frequently spreads intracranially. We compare CT and MRI in identifying intracranial spread and reexamine the route of infiltration. METHOD: One hundred fourteen consecutive patients with proven NPC were evaluated prospectively with T1-, T2-weighted, contrast-enhanced MRI and CT. RESULTS: MRI showed 35 (31%) patients with middle cranial fossa involvement. Twenty-nine (25%) patients had cavernous sinus infiltration, while six (5%) showed only dural thickening. The most common route of spread is through the foramen ovale (FO) (12/35 patients, 34%), followed by skull base destruction (6/35 patients, 17%), foramen lacerum (FL) (6/35 patients, 17%), sphenoid sinus (6/35 patients, 17%), and combined FO and FL (5/35 patients, 14%). Using MRI as a standard, CT demonstrated the following involvement: cavernous sinus in 26 of 29 (90%) patients, FO in 9 of 12 patients, skull base in 6 of 6 patients, FO and FL in 3 of 5 patients, FL in 6 of 6 patients, sphenoid sinus in 6 of 6 patients and dura in 0 of 18 patients. CONCLUSION: It is believed that NPC most commonly spreads intracranially via the FL or by direct erosion. Perineural spread through the FO is an important route, which explains why with CT evidence of cavernous sinus involvement there may be no skull base erosion. These findings are best seen on MRI.     

Gene therapy for malignant gliomas

Malignant gliomas are attractive targets for gene therapy because of their relatively well-localized distribution. Several new strategies have been devised that target different aspects of glioma biology. Gene transfer can be used to synthesize chemotherapy drugs that block DNA synthesis within these highly mitotic tumors. New genes can be introduced that restore the functions of mutated tumor suppressor genes or block the molecular pathways needed for tumor angiogenesis. Alternatively, the immune response to these tumors can be augmented by the local production of cytokines. Finally, viruses themselves can be used as tumoricidal agents by designing viruses that selectively replicate and destroy tumor cells. The advantages and limitations of these approaches are discussed in the context of their possible application to the treatment of these highly lethal malignancies.     

The nondigestible fat sucrose polyester does not stimulate gallbladder emptying in humans

BACKGROUND: We determined the effect of oral ingestion of sucrose polyester, which was approved as a fat replacer in the United States, on gallbladder motility and on the release of cholecystokinin, the hormone that mediates gallbladder emptying. OBJECTIVE: Our objective was to measure effects of sucrose polyester on gallbladder emptying and cholecystokinin release. DESIGN: Eight healthy volunteers (3 men and 5 women) drank 60 mL sucrose polyester, digestible fat, or saline solution in a balanced crossover design on 3 separate days. RESULTS: Mean (+/-SEM) gallbladder emptying, when integrated over time, was low in response to both sucrose polyester (-150 +/- 214 mL x 120 min) and saline solution (-89 +/- 123 mL x 120 min). In contrast, there was marked emptying in response to digestible fat (1069 +/- 253 mL x 120 min). Sucrose polyester did not affect plasma cholecystokinin concentrations (-9.3 +/- 15.0 pmol x 120 min/L), whereas digestible fat resulted in a significant increase (89.5 +/- 44.8 pmol x 120 min/L, P = 0.014) compared with saline solution (-3.0 +/- 13.8 pmol x 120 min/L). CONCLUSIONS: Ingestion of sucrose polyester, in contrast with digestible fat, did not stimulate gallbladder emptying or release of cholecystokinin.