Citations

Abstract Pheochromocytomas are rare catecholamine-producing neuroendocrine tumors that are usually benign, but which may also present as or develop into a malignancy. Predicting such behavior is notoriously difficult and there are currently no curative treatments for malignant tumors. This report follows from a workshop at the Banbury Conference Center, Cold Spring Harbor, New York, on the 16th–18th November 2003, held to review the state of science and to facilitate future progress in the diagnosis and treatment of malignant pheochromocytoma. The rarity of the tumor and the resulting fragmented nature of studies, typically involving small numbers of patients, represent limiting factors to the development of effective treatments and diagnostic or prognostic markers for malignant disease. Such development is being facilitated by the availability of new genomics-based tools, but for such approaches to succeed ultimately requires comprehensive clinical studies involving large numbers of patients, stringently collected clinical data and tumor samples, and interdisciplinary collaborations among multiple specialist centers. Nevertheless, the well-characterized hereditary basis and the unique functional nature of these neuroendocrine tumors provide a useful framework that offers advantages for establishing the pathways of tumorigenesis and malignancy. Such findings may have relevance for understanding the basis of other more common malignancies where similar frameworks are not available. As the relevant pathways leading to pheochromocytoma are established it should be possible to take advantage of the new generation of drugs being developed to target specific pathways in other malignancies. Again the success of this will require well-designed and coordinated multicenter studies.

Background and Purpose— Mutation of serine 1179 to aspartate on the endothelial NO synthase (eNOS) increases NO production in the absence of stimulation by agonists. The present study was designed to determine the effect of recombinant S1179DeNOS gene expression on the vasomotor function of human pial arteries. Methods— Pial arteries were isolated from 28 patients undergoing temporal lobectomy for intractable seizures. Adenoviral vectors (10 10 pfu/mL) encoding β-galactosidase (AdCMVLacZ) or S1179DeNOS (AdCMVS1179DeNOS) were used for ex vivo gene transfer, and vasomotor function was evaluated in control and transduced arteries. Results— Contractions to cumulative additions of U46619 were not affected by expression of LacZ or S1179DeNOS. Endothelium-dependent relaxations to bradykinin or endothelium-independent relaxations to Diethylaminodiazen-1-ium-1,2-dioate were significantly reduced in arteries expressing S1179DeNOS. A superoxide dismutase mimetic, manganese (III) tetrakis (4-benzoic acid) porphyrin chloride, failed to improve the reduced relaxations to bradykinin. The levels of cGMP were significantly elevated in arteries expressing S1179DeNOS. Conclusions— Our results support the concept that high local production of NO in pial arterial wall causes adaptive reduction of vasodilator reactivity to NO.

Purpose To determine whether a matrix metalloproteinase inhibitor improves progression-free survival (PFS) in patients with metastatic breast cancer who have responding or stable disease after first-line chemotherapy. Patients and Methods One hundred seventy-nine eligible patients were randomly assigned to receive oral marimastat (10 mg bid; n = 114) or a placebo (n = 65) within 3 to 6 weeks of completing six to eight cycles of first-line doxorubicin- and/or taxane-containing chemotherapy for metastatic disease. Patients were evaluated every 3 months until disease progression. Results When comparing placebo with marimastat, there was no significant difference in PFS (median, 3.1 months v 4.7 months, respectively; hazard ratio, 1.26; 95% CI, 0.91 to 1.74; P = .16) or overall survival (median, 26.6 months v 24.7 months, respectively; hazard ratio, 1.03; 95% CI, 0.73 to 1.46; P = .86). Patients treated with marimastat were more likely to develop grade 2 or 3 musculoskeletal toxicity (MST), a known complication of the drug indicative of achieving a biologic effect, compared with patients administered placebo (63% v 22%, respectively; P < .0001). Patients with grade 2 or 3 MST had significantly inferior survival compared with patients who had grade 0 or 1 MST (median, 22.5 months v 28.2 months; P = .04). In addition, patients who had a marimastat plasma concentration of at least 10 ng/mL at month 1 and/or 3 were significantly more likely to have grade 2 to 3 MST (P < .0001). Conclusion Marimastat does not prolong PFS when used after first-line chemotherapy for metastatic breast cancer. Patients with higher marimastat levels exhibited MST, and MST was associated with inferior survival.

Cystic fibrosis (CF) is a childhood hereditary disease in which the most common mutant form of the CF transmembrane conductance regulator (CFTR) ΔF508 fails to exit the endoplasmic reticulum (ER). Export of wild-type CFTR from the ER requires the coat complex II (COPII) machinery, as it is sensitive to Sar1 mutants that disrupt normal coat assembly and disassembly. In contrast, COPII is not used to deliver CFTR to ER-associated degradation. We find that exit of wild-type CFTR from the ER is blocked by mutation of a consensus di-acidic ER exit motif present in the first nucleotide binding domain. Mutation of the code disrupts interaction with the COPII coat selection complex Sec23/Sec24. We propose that the di-acidic exit code plays a key role in linking CFTR to the COPII coat machinery and is the primary defect responsible for CF in ΔF508-expressing patients.

Background— Coronary bypass surgery (CABG) and angioplasty (PTCA) have been compared in several randomized trials, but data about long-term economic and quality-of-life outcomes are limited. Methods and Results— Cost and quality-of-life data were collected prospectively from 934 patients who were randomized in the Bypass Angioplasty Revascularization Investigation (BARI) and followed up for 10 to12 years. CABG had 53% higher costs initially, but the gap closed to <5% during the first 2 years; after 12 years, the mean cumulative cost of CABG patients was $123 000 versus $120 750 for PTCA, yielding a cost-effectiveness ratio of $14 300/life-year added. CABG patients experienced significantly greater improvement in their physical functioning for the first 3 years but not in later follow-up. Recurrent angina substantially reduced all quality-of-life measures throughout follow-up. Cumulative costs were significantly higher among patients with diabetes, heart failure, and comorbid conditions and among women; costs also were increased by angina, by the number of revascularization procedures, and among patients who died. Conclusion— Early differences between CABG and PTCA in costs and quality of life were no longer significant at 10 to 12 years of follow-up. CABG was cost-effective as compared with PTCA for multivessel disease.

Abstract Inhaled glucocorticosteroids (ICS) are commonly prescribed for chronic obstructive pulmonary disease. No adverse effect on bone mineral density (BMD) has been proven. In a randomized double-blind, placebo-controlled trial at seven centers in North America, we recruited 412 current smokers or recent quitters with mild to moderate chronic obstructive pulmonary disease. They used inhaled triamcinolone acetonide, 600 mcg, or placebo, twice daily. We measured femoral neck and lumbar spine BMD at baseline and after 1 and 3 years, and serum osteocalcin at baseline, 3 months, 1 year, and 3 years. After 3 years, BMD at the femoral neck decreased 1.78% more with ICS than with placebo (p &lt; 0.001). More participants in the ICS group experienced 6% or more loss of femoral neck BMD (p = 0.002). Lumbar spine BMD increased in the placebo group by 0.98% but decreased by 0.35% in the ICS group (a difference of 1.33%, p = 0.007). Changes in osteocalcin did not correlate with changes in BMD. Fractures, lost height, or osteoporosis diagnoses were not increased among ICS users compared with placebo users. In summary, the use of inhaled triamcinolone acetonide was associated with loss of BMD at the femoral neck and lumbar spine after 3 years of treatment.