Reoperation for hyperparathyroidism in multiple endocrine neoplasia type 1.

BACKGROUND: Patients with multiple endocrine neoplasia type 1 and hyperparathyroidism often undergo multiple operations because of inadequate initial surgery, presence of supernumerary and ectopic glands, regrowth of remnant glands, or autograft hyperfunction. Management of this patient population is complex. METHODS: From January 1975 to December 2000 we performed 94 reoperative parathyroidectomies consisting of 79 neck reexplorations, 12 autograft removals, and 3 median sternotomies in 75 patients. Data were gathered by retrospective chart review and follow-up telephone interviews. RESULTS: Excluding autograft excision, reoperative surgery was successful (normocalcemia longer than 6 months) in 91%; autograft removal was successful in only 58%. With a median follow-up of 59 months, 64% of patients are currently free from hypercalcemia, and this outcome was not influenced by the total number of glands resected. The median time to recurrent hypercalcemia was 125 months. Thirty patients received an autograft after reoperation. The complication rate for all reoperations was 12%, including permanent recurrent laryngeal nerve injury in 2 patients (2.1%). CONCLUSIONS: Reoperative parathyroidectomy in patients with multiple endocrine neoplasia type 1 was safe and successful in the majority of patients; however, recurrent hyperparathyroidism is likely to develop in most individuals beyond 10 years of follow-up. The total number of glands accounted for after reoperation is not associated with successful outcome.

Oncolytic virotherapy for ovarian carcinomatosis using a replication-selective vaccinia virus armed with a yeast cytosine deaminase gene.

In this study, we assessed the ability of a highly tumor-selective oncolytic vaccinia virus armed with a yeast cytosine deaminase gene to infect and lyse human and murine ovarian tumors both in vitro and in vivo. The virus vvDD-CD could infect, replicate in and effectively lyse both human and mouse ovarian cancer cells in vitro. In two different treatment schedules involving either murine MOSEC or human A2780 ovarian carcinomatosis models, regional delivery of vvDD-CD selectively targeted tumor cells and ovarian tissue, effectively delaying the development of either tumor or ascites and leading to significant survival advantages. Oncolytic virotherapy using vvDD-CD in combination with the prodrug 5-fluorocytosine conferred an additional long-term survival advantage upon tumor-bearing immunocompetent mice. These findings demonstrate that a tumor-selective oncolytic vaccinia combined with gene-directed enzyme prodrug therapy is a highly effective strategy for treating advanced ovarian cancers in both syngeneic mouse and human xenograft models. Given the biological safety, tumor selectivity and oncolytic potency of this armed oncolytic virus, this dual therapy merits further investigation as a promising new treatment for metastatic ovarian cancer.

Asymmetric distribution of pause transfer sequences in apolipoprotein B-100.

Lipoprotein assembly requires a complex and regulated set of events that includes apolipoprotein B (apoB) translocation across the endoplasmic reticulum (ER) membrane, folding, and association with lipids. Unlike simple secretory proteins which are cotranslationally translocated directly into the ER lumen, nascent apoB contains pause transfer (PT) sequences that direct the transient stopping and subsequent restarting of its translocation, a phenomenon termed translocational pausing. During one particular translocational pause in apoB, the ribosome-membrane junction and ER translocation channel have been shown to be altered in such a way as to expose the nascent polypeptide to the cytosol and direct a change in the proteins neighboring the nascent chain. In this study, we have experimentally identified the location and distribution of the translocational pauses that are present throughout apoB-100. We find that pause transfer sequences are distributed asymmetrically, clustering in three distinct domains: a) nine functional PT sequences appear in the amino terminal 20% of apoB, b) four more PT sequences occur just before the end of apoB-48, and c) an additional ten PT sequences are found between apoB-65-95. These clusters are interrupted by two lipid binding regions of approximately 100 kD each in which no PT sequences occur. The implications of this asymmetric distribution of PT sequences, and their correlation with previously hypothesized structural and functional domains of apoB, are discussed.