Citations

Purpose To describe the demographic and tumor related characteristics and outcomes for patients with primary T-cell CNS lymphoma (TPCNSL). Patients and Methods A retrospective series of patients with TPCNSL was compiled from twelve cancer centers in seven countries. Results We identified 45 patients with a median age of 60 years (range, 3 to 84 years). Twenty (44%) had Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1. Twenty-six (58%) had involvement of a cerebral hemisphere and sixteen (36%) had lesions of deeper sites in the brain. Serum lactate dehydrogenase was elevated in 7 (32%) of 22 patients, and CSF protein was elevated in 19 of 24 patients (79%) with available data. The median disease-specific survival (DSS) was 25 months (95% CI, 11 to 38 months). The 2- and 5-year DSS were 51% (95% CI, 35% to 66%) and 17% (95% CI, 6% to 34%), respectively. Univariate and multivariate analyses were conducted for age (≤ 60 v > 60 years), PS (0 or 1 v 2, 3, or 4), involvement of deep structures of the CNS (no v yes), and methotrexate (MTX) use in the primary treatment (yes v no). Only PS and MTX use were significantly associated with better outcome with hazard ratios of 0.2 (95% CI, 0.1 to 0.4) and 0.4 (95% CI, 0.2 to 0.8), respectively. Conclusion This is the largest series ever assembled of TPCNSL. The presentation and outcome appear similar to that of B cell PCNSL. PS 0 or 1 and administration of MTX are associated with better survival.

Purpose Preclinical studies of mafosfamide, a preactivated cyclophosphamide analog, were performed to define a tolerable and potentially active target concentration for intrathecal (IT) administration. A phase I and pharmacokinetic study of IT mafosfamide was performed to determine a dose for subsequent phase II trials. Patients and Methods In vitro cytotoxicity studies were performed in MCF-7, Molt-4, and rhabdomyosarcoma cell lines. Feasibility and pharmacokinetic studies were performed in nonhuman primates. These preclinical studies were followed by a phase I trial in patients with neoplastic meningitis. There were five dose levels ranging from 1 mg to 6.5 mg. Serial CSF samples were obtained for pharmacokinetic studies in a subset of patients with Ommaya reservoirs. Results The cytotoxic target exposure for mafosfamide was 10 μmol/L. Preclinical studies demonstrated that this concentration could be easily achieved in ventricular CSF after intraventricular dosing. In the phase I clinical trial, headache was the dose-limiting toxicity. Headache was ameliorated at 5 mg by prolonging the infusion rate to 20 minutes, but dose-limiting headache occurred at 6.5 mg dose with prolonged infusion. Ventricular CSF mafosfamide concentrations at 5 mg exceeded target cytotoxic concentrations after an intraventricular dose, but lumbar CSF concentrations 2 hours after the dose were less than 10 μmol/L. Therefore, a strategy to alternate dosing between the intralumbar and intraventricular routes was tested. Seven of 30 registrants who were assessable for response had a partial response, and six had stable disease. Conclusion The recommended phase II dose for IT mafosfamide, administered without concomitant analgesia, is 5 mg over 20 minutes.

Previous studies in native tissues have produced conflicting data on the localization and metabolic fate of WT and ΔF508 cystic fibrosis transmembrane regulator (CFTR) in the lung. Combining immunocytochemical and biochemical studies utilizing new high-affinity CFTR mAbs with ion transport assays, we examined both 1) the cell type and region specific expression of CFTR in normal airways and 2) the metabolic fate of ΔF508 CFTR and associated ERM proteins in the cystic fibrosis lung. Studies of lungs from a large number of normal subjects revealed that WT CFTR protein localized to the apical membrane of ciliated cells within the superficial epithelium and gland ducts. In contrast, other cell types in the superficial, gland acinar, and alveolar epithelia expressed little WT CFTR protein. No ΔF508 CFTR mature protein or function could be detected in airway specimens freshly excised from a large number of ΔF508 homozygous subjects, despite an intact ERM complex. In sum, our data demonstrate that WT CFTR is predominantly expressed in ciliated cells, and ΔF508 CFTR pathogenesis in native tissues, like heterologous cells, reflects loss of normal protein processing.

Clinical Pharmacology & Therapeutics (2003) 73, P29–P29; doi:

Patent ductus arteriosus (PDA) is a common congenital heart disease that results when the ductus arteriosus, a muscular artery, fails to remodel and close after birth. A syndromic form of this disorder, Char syndrome, is caused by mutation in TFAP2B , the gene encoding a neural crest-derived transcription factor. Established features of the syndrome are PDA, facial dysmorphology, and fifth-finger clinodactyly. Disease-causing mutations are missense and are proposed to be dominant negative. Because only a small number of families have been reported, there is limited information on the spectrum of mutations and resulting phenotypes. We report the characterization of two kindreds (K144 and K145) with Char syndrome containing 22 and 5 affected members, respectively. Genotyping revealed linkage to TFAP2B in both families. Sequencing of TFAP2B demonstrated mutations in both kindreds that were not found among control chromosomes. Both mutations altered highly conserved bases in introns required for normal splicing as demonstrated by biochemical studies in mammalian cells. The abnormal splicing results in mRNAs containing frameshift mutations that are expected to be degraded by nonsense-mediated mRNA decay, resulting in haploinsufficiency; even if produced, the protein in K144 would lack DNA binding and dimerization motifs and would likely result in haploinsufficiency. Examination of these two kindreds for phenotypes that segregate with TFAP2B mutations identified several phenotypes not previously linked to Char syndrome. These include parasomnia and dental and occipital-bone abnormalities. The striking sleep disorder in these kindreds implicates TFAP2B-dependent functions in the normal regulation of sleep.

Using quantitative light microscopy and a modified immunoelectron microscopic technique, we have characterized the entry pathway of the cholera toxin binding subunit (CTB) in primary embryonic fibroblasts. CTB trafficking to the Golgi complex was identical in caveolin-1null (Cav1−/−) mouse embryonic fibroblasts (MEFs) and wild-type (WT) MEFs. CTB entry in the Cav1−/− MEFs was predominantly clathrin and dynamin independent but relatively cholesterol dependent. Immunoelectron microscopy was used to quantify budded and surface-connected caveolae and to identify noncaveolar endocytic vehicles. In WT MEFs, a small fraction of the total Cav1-positive structures were shown to bud from the plasma membrane (2% per minute), and budding increased upon okadaic acid or lactosyl ceramide treatment. However, the major carriers involved in initial entry of CTB were identified as uncoated tubular or ring-shaped structures. These carriers contained GPI-anchored proteins and fluid phase markers and represented the major vehicles mediating CTB uptake in both WT and caveolae-null cells.

Background— Observed rates of restenosis after drug-eluting stenting are low (<10%). Identification of a reliable and powerful angiographic end point will be useful in future trials. Methods and Results— Late loss (postprocedural minimum lumen diameter minus 8-month minimum lumen diameter) was measured in the angiographic cohorts of the SIRIUS (n=703) and E-SIRIUS (n=308) trials. Two techniques, the standard normal approximation and an optimized power transformation, were used to predict binary angiographic restenosis rates and compare them with observed restenosis rates. The mean in-stent late loss observed in the SIRIUS trial was 0.17±0.45 mm (sirolimus) versus 1.00±0.70 mm (control). If a normal distribution was assumed, late loss accurately estimated in-stent binary angiographic restenosis for the control arm (predicted 35.4% versus observed 35.4%) but underestimated it in the sirolimus arm (predicted 0.6% versus observed 3.2%). Power transformation improved the reliability of the estimate in the sirolimus arm (predicted 3.2% [CI 1.0% to 6.7%]) with similar improvements in the E-SIRIUS trial (predicted 4.0% [CI 1.2% to 7.0%] versus observed 3.9%). In the sirolimus-eluting stent arm, in-stent late loss correlated better with target-lesion revascularization than in-segment late loss (c-statistic=0.915 versus 0.665). Conclusions— Because distributions of late loss with a low mean are right-skewed, the use of a transformation improves the accuracy of predicting low binary restenosis rates. Late loss is monotonically correlated with the probability of restenosis and yields a more efficient estimate of the restenosis process in the era of lower binary restenosis rates.

Background— Sirolimus-eluting stents (SESs) reduce angiographic restenosis in patients with focal, native coronary artery stenoses. This study evaluated the usefulness of SESs in complex native-vessel lesions at high risk for restenosis. Methods and Results— Angiographic follow-up at 240 days was obtained in 701 patients with long (15- to 25-mm) lesions in small-diameter (2.5- to 3.5-mm) native vessels who were randomly assigned to treatment with SESs or bare-metal stents (BMSs) in the SIRIUS trial. Quantitative angiographic measurements of minimal lumen diameter and percent diameter stenosis were obtained within the treated segment, within the stent, and within its 5-mm proximal and distal edges. Patients treated with SESs had lower rates of binary (>50% diameter stenosis) angiographic restenosis within the segment (8.9% versus 36.3% with the BMS; P <0.001) and within the stent (3.2% versus 35.4% with the BMS; P <0.001). SESs were associated with significantly less late lumen loss within the treated segment, within the stent, and within its 5-mm proximal and distal edges (all P <0.001). The reduction of restenosis with the SES was consistent in patients at risk for restenosis, including those with small vessels, long lesions, and diabetes mellitus. The frequency of late aneurysms was similar in the 2 groups. Conclusions— Compared with BMSs, SESs reduced angiographic late lumen loss within the stent and its adjacent 5-mm margins in patients with complex native-vessel lesions.