Long-term safety and efficacy of anacetrapib in patients with atherosclerotic vascular disease.

AIMS: REVEAL was the first randomized controlled trial to demonstrate that adding cholesteryl ester transfer protein inhibitor therapy to intensive statin therapy reduced the risk of major coronary events. We now report results from extended follow-up beyond the scheduled study treatment period. METHODS AND RESULTS: A total of 30 449 adults with prior atherosclerotic vascular disease were randomly allocated to anacetrapib 100 mg daily or matching placebo, in addition to open-label atorvastatin therapy. After stopping the randomly allocated treatment, 26 129 survivors entered a post-trial follow-up period, blind to their original treatment allocation. The primary outcome was first post-randomization major coronary event (i.e. coronary death, myocardial infarction, or coronary revascularization) during the in-trial and post-trial treatment periods, with analysis by intention-to-treat. Allocation to anacetrapib conferred a 9% [95% confidence interval (CI) 3-15%; P = 0.004] proportional reduction in the incidence of major coronary events during the study treatment period (median 4.1 years). During extended follow-up (median 2.2 years), there was a further 20% (95% CI 10-29%; P < 0.001) reduction. Overall, there was a 12% (95% CI 7-17%, P < 0.001) proportional reduction in major coronary events during the overall follow-up period (median 6.3 years), corresponding to a 1.8% (95% CI 1.0-2.6%) absolute reduction. There were no significant effects on non-vascular mortality, site-specific cancer, or other serious adverse events. Morbidity follow-up was obtained for 25 784 (99%) participants. CONCLUSION: The beneficial effects of anacetrapib on major coronary events increased with longer follow-up, and no adverse effects emerged on non-vascular mortality or morbidity. These findings illustrate the importance of sufficiently long treatment and follow-up duration in randomized trials of lipid-modifying agents to assess their full benefits and potential harms. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number (ISRCTN) 48678192; ClinicalTrials.gov No. NCT01252953; EudraCT No. 2010-023467-18.

Randomized Evaluation of the Effects of Anacetrapib through Lipid-modification (REVEAL)-A large-scale, randomized, placebo-controlled trial of the clinical effects of anacetrapib among people with established vascular disease: Trial design, recruitment, and baseline characteristics.

Patients with prior vascular disease remain at high risk for cardiovascular events despite intensive statin-based treatment. Inhibition of cholesteryl ester transfer protein by anacetrapib reduces low-density lipoprotein (LDL) cholesterol by around 25% to 40% and more than doubles high-density lipoprotein (HDL) cholesterol. However, it is not known if these apparently favorable lipid changes translate into reductions in cardiovascular events. METHODS: The REVEAL study is a randomized, double-blind, placebo-controlled clinical trial that is assessing the efficacy and safety of adding anacetrapib to effective LDL-lowering treatment with atorvastatin for an average of at least 4years among patients with preexisting atherosclerotic vascular disease. The primary assessment is an intention-to-treat comparison among all randomized participants of the effects of allocation to anacetrapib on major coronary events (defined as the occurrence of coronary death, myocardial infarction, or coronary revascularization). RESULTS: Between August 2011 and October 2013, 30,449 individuals in Europe, North America, and China were randomized to receive anacetrapib 100mg daily or matching placebo. Mean (SD) age was 67 (8) years, 84% were male, 88% had a history of coronary heart disease, 22% had cerebrovascular disease, and 37% had diabetes mellitus. At the randomization visit (after at least 8weeks on a protocol-defined atorvastatin regimen), mean plasma LDL cholesterol was 61 (15) mg/dL and HDL cholesterol was 40 (10) mg/dL. INTERPRETATION: The REVEAL trial will provide a robust evaluation of the clinical efficacy and safety of adding anacetrapib to an effective statin regimen. Results are anticipated in 2017.

Benefits of sulfamethoxazole-trimethoprim prophylaxis on rates of sepsis after kidney transplant.

BACKGROUND: The use of potent immunosuppression increases the risk of infectious complications following kidney transplantation. Sulfamethoxazole-trimethoprim (SMX/TMP) is an inexpensive broad-spectrum antimicrobial agent used in our center as lifelong prophylaxis against Pneumocystis jirovecii, unless contraindicated. This study evaluated the clinical impact of SMX/TMP prophylaxis compared with no prophylaxis with SMX/TMP (NoPPx), but with alternative agents. METHODS: This was a retrospective cohort analysis of renal transplant recipients (RTR) transplanted from January 2002 through December 2010. Patients were divided into SMX/TMP group and NoPPX group, based on whether they received prophylaxis with SMX/TMP or not, and rates of sepsis were compared between groups. We also analyzed the pathogens and source implicated in these episodes, as well as the dose of SMX/TMP. Rates were compared using multivariate logistic regression. RESULTS: With a mean follow-up of 4.8 (± 2.5) years, 63 cases of sepsis occurred in 1224 patients (5.1%), and 60% of these cases had a urinary source. The risk of sepsis was significantly reduced with prophylaxis vs. NoPPx (13.3% vs. 4.3% for SMX/TMP, P < 0.001), and this association was maintained through multivariate regression. Sepsis was associated with a numerically increased risk of graft loss and death that was not significantly affected by use of SMX/TMP. CONCLUSIONS: Prophylaxis with SMX/TMP is an inexpensive way to reduce the incidence of sepsis in RTR.

Identifying the target NSCLC patient for maintenance therapy: an analysis from a placebo-controlled, phase III trial of maintenance pemetrexed (H3E-MC-JMEN).

BACKGROUND: This was a post hoc analysis of patients with non-squamous histology from a phase III maintenance pemetrexed study in advanced non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: The six symptom items' [average symptom burden index (ASBI)] mean at baseline was calculated using the lung cancer symptom scale (LCSS). Low and high symptom burden (LSB, ASBI < 25; HSB, ASBI ≥ 25) and performance status (PS: 0, 1) subgroups were analyzed for treatment effect on progression-free survival (PFS) and overall survival (OS) using the Cox proportional hazard models adjusted for demographic/clinical factors. RESULTS: Significantly longer PFS and OS for pemetrexed versus placebo occurred in LSB patients [PFS: median 5.1 versus 2.4 months, hazard ratio (HR) 0.49, P < 0.0001; OS: median 17.5 versus 11.0 months, HR 0.63, P = 0.0012] and PS 0 patients (PFS: median 5.5 versus 1.7 months, HR 0.36, P < 0.0001; OS: median 17.7 versus 10.3 months, HR 0.54, P = 0.0019). Significantly longer PFS, but not OS, occurred in HSB patients (median 3.7 versus 2.8 months, HR 0.50, P = 0.0033) and PS 1 patients (median 4.4 versus 2.8 months, HR 0.60, P = 0.0002). CONCLUSIONS: ASBI and PS are associated with survival for non-squamous NSCLC patients, suggesting that maintenance pemetrexed is useful for LSB or PS 0 patients following induction.

The impact of focused transthoracic echocardiography in the pre-operative clinic.

Patients with suspected or symptomatic cardiac disease, associated with increased peri-operative risk, are often seen by anaesthetists in the pre-assessment clinic. The use of transthoracic echocardiography in this setting has not been reported. This prospective observational study investigated the effect of echocardiography on the anaesthetic management plan in 100 patients who were older than 65 years or had suspected cardiac disease. Echocardiography was performed by an anaesthetist, and was validated by a cardiologist. Overall, the anaesthetic plan was changed in 54 patients. Haemodynamically significant cardiac disease was revealed in 31 patients, resulting in a step-up of treatment in 20 patients, including: cardiology referral (four patients); altered surgical (two) and anaesthetic (four) technique; use of invasive monitoring (13); planned use of vasopressor infusion (10); and postoperative high dependency care (five). Reassuring negative findings in 69 patients led to a step-down in treatment in 34 patients: altered anaesthetic technique (six); procedure not cancelled (10); cardiology referral not made (10); use of invasive monitoring not required (seven); and high dependency care not booked (11). We conclude that focused transthoracic echocardiography in the pre-operative clinic is feasible and frequently alters management in patients with suspected cardiac disease.

SLCO1B1 variants and statin-induced myopathy--a genomewide study.

BACKGROUND: Lowering low-density lipoprotein cholesterol with statin therapy results in substantial reductions in cardiovascular events, and larger reductions in cholesterol may produce larger benefits. In rare cases, myopathy occurs in association with statin therapy, especially when the statins are administered at higher doses and with certain other medications. METHODS: We carried out a genomewide association study using approximately 300,000 markers (and additional fine-mapping) in 85 subjects with definite or incipient myopathy and 90 controls, all of whom were taking 80 mg of simvastatin daily as part of a trial involving 12,000 participants. Replication was tested in a trial of 40 mg of simvastatin daily involving 20,000 participants. RESULTS: The genomewide scan yielded a single strong association of myopathy with the rs4363657 single-nucleotide polymorphism (SNP) located within SLCO1B1 on chromosome 12 (P=4x10(-9)). SLCO1B1 encodes the organic anion-transporting polypeptide OATP1B1, which has been shown to regulate the hepatic uptake of statins. The noncoding rs4363657 SNP was in nearly complete linkage disequilibrium with the nonsynonymous rs4149056 SNP (r(2)=0.97), which has been linked to statin metabolism. The prevalence of the rs4149056 C allele in the population was 15%. The odds ratio for myopathy was 4.5 (95% confidence interval [CI], 2.6 to 7.7) per copy of the C allele, and 16.9 (95% CI, 4.7 to 61.1) in CC as compared with TT homozygotes. More than 60% of these myopathy cases could be attributed to the C variant. The association of rs4149056 with myopathy was replicated in the trial of 40 mg of simvastatin daily, which also showed an association between rs4149056 and the cholesterol-lowering effects of simvastatin. No SNPs in any other region were clearly associated with myopathy. CONCLUSIONS: We have identified common variants in SLCO1B1 that are strongly associated with an increased risk of statin-induced myopathy. Genotyping these variants may help to achieve the benefits of statin therapy more safely and effectively. (Current Controlled Trials number, ISRCTN74348595.)

Size-dependent effects of tungsten carbide-cobalt particles on oxygen radical production and activation of cell signaling pathways in murine epidermal cells.

Hard metal or cemented carbide consists of a mixture of tungsten carbide (WC) (85%) and metallic cobalt (Co) (5-15%). WC-Co is considered to be potentially carcinogenic to humans. However, no comparison of the adverse effects of nano-sized WC-Co particles is available to date. In the present study, we compared the ability of nano- and fine-sized WC-Co particles to form free radicals and propensity to activate the transcription factors, AP-1 and NF-kappaB, along with stimulation of mitogen-activated protein kinase (MAPK) signaling pathways in a mouse epidermal cell line (JB6 P(+)). Our results demonstrated that nano-WC-Co generated a higher level of hydroxyl radicals, induced greater oxidative stress, as evidenced by a decrease of GSH levels, and caused faster JB6 P(+) cell growth/proliferation than observed after exposure of cells to fine WC-Co. In addition, nano-WC-Co activated AP-1 and NF-kappaB more efficiently in JB6(+/+) cells as compared to fine WC-Co. Experiments using AP-1-luciferase reporter transgenic mice confirmed the activation of AP-1 by nano-WC-Co. Nano- and fine-sized WC-Co particles also stimulated MAPKs, including ERKs, p38, and JNKs with significantly higher potency of nano-WC-Co. Finally, co-incubation of the JB6(+/+) cells with N-acetyl-cysteine decreased AP-1 activation and phosphorylation of ERKs, p38 kinase, and JNKs, thus suggesting that oxidative stress is involved in WC-Co-induced toxicity and AP-1 activation.

A calmodulin-related protein that suppresses posttranscriptional gene silencing in plants.

Posttranscriptional gene silencing (PTGS) is an ancient eukaryotic regulatory mechanism in which a particular RNA sequence is targeted and destroyed. The helper component-proteinase (HC-Pro) of plant potyviruses suppresses PTGS in plants. Using a yeast two-hybrid system, we identified a calmodulin-related protein (termed rgs-CaM) that interacts with HC-Pro. Here we report that rgs-CaM, like HC-Pro itself, suppresses gene silencing. Our work is the first report identifying a cellular suppressor of PTGS.

Study of the effectiveness of additional reductions in cholesterol and homocysteine (SEARCH): characteristics of a randomized trial among 12064 myocardial infarction survivors.

BACKGROUND: Cholesterol lowering with statins reduces the risk of vascular disease, but uncertainty remains as to whether more intensive statin therapy produces worthwhile benefits safely. Blood homocysteine level is an independent marker of vascular risk, but it is unknown whether this association is causal. METHODS AND RESULTS: 12,064 myocardial infarction survivors have been randomized to more versus less intensive cholesterol-lowering treatment using simvastatin 80 mg versus 20 mg daily. Allocation to more intensive treatment has yielded average further low-density lipoprotein cholesterol reductions of 0.5 mmol/L at 2 months and 0.4 mmol/L at 5 years. In addition, using a factorial design, these patients have been randomized to homocysteine lowering with folic acid 2 mg plus vitamin B12 1 mg daily versus matching placebo, yielding an average 3 to 4 mumol/L reduction in homocysteine. After 6 years of median follow-up, the annual overall rate of major vascular events is approximately 3%. Follow-up is scheduled to continue for a median of 7 years. CONCLUSION: SEARCH should provide reliable evidence about the efficacy and safety of prolonged use of more intensive cholesterol-lowering therapy and, separately, of folate-based homocysteine-lowering therapy in a high-risk population.

The synthesis of ribosomal proteins S16 and L32 is not autogenously regulated during mouse myoblast differentiation.

A series of mouse myoblast cell lines was constructed that contain 1 to 34 extra copies of either the S16 or the L32 ribosomal protein (r-protein) gene. The metabolism of the S16 and L32 r-proteins and mRNAs was examined in myoblasts and fibers of these cell lines to determine whether the synthesis of these r-proteins is autogenously regulated. The incorporation of extra copies of these r-protein genes into the genome resulted in the accumulation of the corresponding mRNAs to levels that were directly proportional to the gene copy number. The levels of the overproduced mRNAs decreased after the differentiation of mouse myoblasts into fibers in parallel to the decrease in the levels of the endogenous r-protein mRNAs. These results indicate that the synthesis of these r-proteins is not autogenously regulated at the level of transcription, RNA processing, or mRNA stability. To determine whether the synthesis of these r-proteins is regulated at the level of translation, the translational efficiencies of the overproduced mRNAs were inferred from their distribution in polysomal gradients. The translational efficiencies of these overproduced r-protein mRNAs in myoblasts are similar to those of the endogenous r-protein mRNAs. After myoblast differentiation, the translational efficiencies of the overproduced r-protein mRNAs decrease exactly like those of the endogenous r-protein mRNAs. Examination of the synthesis and stability of r-proteins in one of the L32-overproducing cell lines demonstrated that the overproduced L32 r-protein degrades shortly after its synthesis. The synthesis and stability of the other r-proteins were unaffected in this cell line. Thus, the synthesis of S16 and L32 r-proteins is not autogenously regulated at any level in either myoblasts or fibers.

Transcription of the mouse ribosomal spacer region.

This paper describes experiments designed to test the hypothesis that DNA sequences upstream from the mouse rRNA promoter are transcribed in vivo or in vitro. Plasmid pB28 contains a SalI restriction fragment that extends from -169 to -1,894 base pairs, with respect to the origin of transcription of pre-rRNA. Labeled RNA synthesized in intact cells does not hybridize to this region. Neither S1 nuclease mapping nor RNA dot blot hybridization revealed the presence of sequences complementary to this region. Transcriptional studies carried out in vitro indicated that this region is not transcribed under conditions that are optimal for utilization of the authentic rRNA promoter. Moreover, this region does not appear to form stable transcription complexes with RNA polymerase I transcription components. These data indicate that the mouse rDNA repeating unit differs from those of Xenopus spp. and Drosophila melanogaster in that reduplicated RNA polymerase I promoters are not found in the mouse rDNA spacer region.

Mouse rDNA: sequences and evolutionary analysis of spacer and mature RNA regions.

Two regions of mouse rDNA were sequenced. One contained the last 323 nucleotides of the external transcribed spacer and the first 595 nucleotides of 18S rRNA; the other spanned the entire internal transcribed spacer and included the 3' end of 18S rRNA, 5.8S rRNA, and the 5' end of 28S rRNA. The mature rRNA sequences are very highly conserved from yeast to mouse (unit evolutionary period, the time required for a 1% divergence of sequence, was 30 X 10(6) to 100 X 10(6) years). In 18S rRNA, at least some of the evolutionary expansion and increase in G + C content is due to a progressive accretion of discrete G + C-rich insertions. Spacer sequence comparisons between mouse and rat rRNA reveal much more extensive and frequent insertions and substitutions of G + C-rich segments. As a result, spacers conserve overall G + C richness but not sequence (UEP, 0.3 X 10(6) years) or specific base-paired stems. Although no stems analogous to those bracketing 16S and 23S rRNA in Escherichia coli pre-rRNA are evident, certain features of the spacer regions flanking eucaryotic mature rRNAs are conserved and could be involved in rRNA processing or ribosome formation. These conserved regions include some short homologous sequence patterns and closely spaced direct repeats.

Location of the initial cleavage sites in mouse pre-rRNA.

The locations of three cleavages that can occur in mouse 45S pre-rRNA were determined by Northern blot hybridization and S1 nuclease mapping techniques. These experiments indicate that an initial cleavage of 45S pre-rRNA can directly generate the mature 5' terminus of 18S rRNA. Initial cleavage of 45S pre-rRNA can also generate the mature 5' terminus of 5.8S rRNA, but in this case cleavage can occur at two different locations, one at the known 5' terminus of 5.8S rRNA and another 6 or 7 nucleotides upstream. This pattern of cleavage results in the formation of cytoplasmic 5.8S rRNA with heterogeneous 5' termini. Further, our results indicate that one pathway for the formation of the mature 5' terminus of 28S rRNA involves initial cleavages within spacer sequences followed by cleavages which generate the mature 5' terminus of 28S rRNA. Comparison of these different patterns of cleavage for mouse pre-rRNA with that for Escherichia coli pre-rRNA implies that there are fundamental differences in the two processing mechanisms. Further, several possible cleavage signals have been identified by comparing the cleavage sites with the primary and secondary structure of mouse rRNA (see W. E. Goldman, G. Goldberg, L. H. Bowman, D. Steinmetz, and D. Schlessinger, Mol. Cell. Biol. 3:1488-1500, 1983).

Ramucirumab as second-line treatment in patients with advanced hepatocellular carcinoma following first-line therapy with sorafenib: Patient-focused outcome results from the randomised phase III REACH study.

PURPOSE: To report patient-focused outcomes as measured by quality of life (QoL) and performance status (PS) in REACH, a phase III placebo-controlled randomised study, assessing ramucirumab in advanced hepatocellular carcinoma (HCC) patients who received prior sorafenib. METHODS: Eligible patients had advanced HCC, Child-Pugh A, PS 0 or 1 and prior sorafenib. Patients received ramucirumab (8 mg/kg) or placebo (1:1) on day 1 of a 2-week cycle. QoL was assessed by FACT Hepatobiliary Symptom Index (FHSI)-8 and EuroQoL (EQ-5D) at baseline; cycles 4, 10, and 16; and end of treatment. PS was assessed at baseline, each cycle, and end of treatment. Deterioration in FHSI-8 was defined as a ≥3-point decrease from baseline and PS deterioration was defined as a change of ≥2. Both intention-to-treat and pre-specified subgroup of patients with baseline serum alpha-fetoprotein (AFP) ≥400 ng/mL were assessed. RESULTS: There were 565 patients randomised to ramucirumab and placebo. Compliance with FHSI and EQ-5D was high and similar between groups. In the ITT population, deterioration in FHSI-8, EQ-5D, and PS was similar between ramucirumab and placebo. In patients with baseline AFP ≥400 ng/mL, ramucirumab significantly reduced deterioration in FHSI-8 at the end of treatment compared with placebo (P = 0.0381), and there was a trend towards a delay in the deterioration of symptoms in FHSI-8 (HR 0.690; P = 0.054) and PS (HR 0.642; P = 0.057) in favour of ramucirumab. CONCLUSIONS: We report one of the most comprehensive data sets of QoL and symptom burden in patients undergoing systemic therapy for advanced HCC. Ramucirumab was associated with no worsening of QoL. In patients with baseline AFP ≥400 ng/mL, the significant survival benefit observed in patients treated with ramucirumab was coupled with a trend in patient-focused outcome benefits. CLINICAL TRIAL REGISTRATION: NCT01140347.

Genetic staging of unresectable or metastatic neuroblastoma in infants: a Pediatric Oncology Group study.

BACKGROUND: Current staging systems for unresectable or metastatic neuroblastoma do not reliably predict responses to chemotherapy in infants under 1 year of age. Previous studies have indicated that the DNA content, or ploidy, of malignant neuroblasts can discriminate between good and poor responders in this group of patients, but the clinical utility of ploidy assessment has remained in question. PURPOSE: We tested, in a prospective nonrandomized study, the hypothesis that neuroblast ploidy could be used as the sole guide for treatment selection in infants with unresectable or metastatic tumors and could differentiate between those who would respond to our previous standard regimen and those who would benefit from an immediate switch to another therapy. METHODS: One hundred seventy-seven infants were enrolled in this trial. Five of these infants were subsequently excluded (two ineligible, two lacking ploidy information, and one protocol violation); therefore, 172 patients were included in the study. One hundred thirty infants with hyperdiploid tumors (DNA index > 1.0; better prognosis in retrospective studies) were treated with a well-tolerated regimen of cyclophosphamide (150 mg/m2 per day orally or intravenously on days 1-7) and doxorubicin (35 mg/m2 intravenously on day 8). Forty-two infants with diploid tumors (DNA index = 1.0; worse prognosis in retrospective studies) received cisplatin (90 mg/m2 intravenously on day 1) and teniposide (100 mg/ m2 intravenously on day 3) after an initial course of cyclophosphamide plus doxorubicin. Statistical end points were response and long-term survival. In addition, we assessed within each ploidy group (i.e., patients with hyperdiploid tumors and those with diploid tumors) the prognostic significance of NMYC gene copy number, tumor stage, and other variables commonly measured in this disease. RESULTS: Of the 127 assessable infants with hyperdiploid tumors, 115 (91%) had complete responses--85 after receiving five courses of cyclophosphamide plus doxorubicin and 30 after receiving further therapy including cisplatin plus teniposide. The 3-year survival estimate for the entire hyperdiploid group was 94% (95% confidence interval [CI] = 89%-98%). Nineteen (46%) of 41 assessable infants with diploid tumors were complete responders. The overall 3-year survival estimate for this group was 55% (95% CI = 39%-70%). Prognostic factor analysis indicated that NMYC gene amplification and an elevated serum lactate dehydrogenase level were statistically significant markers of higher risk disease within the diploid group (two-sided P values of .005 and .003, respectively). Only NMYC was predictive in the hyperdiploid group (P = .003). CONCLUSION: Use of a prognostic staging system based on tumor cell ploidy, augmented with the NMYC gene copy number and serum level of lactate dehydrogenase, would very likely improve the treatment of infants with unresectable or metastatic neuroblastoma. Patients with diploid tumors characterized by an amplified NMYC locus represent a particularly unfavorable risk group that may benefit from innovative new therapies.

Phase I study of escalating targeted doses of carboplatin combined with ifosfamide and etoposide in treatment of newly diagnosed pediatric solid tumors.

BACKGROUND: The combination of carboplatin, ifosfamide, and etoposide has shown promising activity in a variety of relapsed childhood solid tumors but has not been studied in newly diagnosed patients. PURPOSE: The tolerance for and activity of escalating targeted doses of carboplatin combined with ifosfamide and etoposide (ICE) were assessed in children with advanced germ cell tumors or other rare solid tumors for which no standard therapy exists. METHODS: Fifteen children with newly diagnosed solid tumors received ICE chemotherapy. Individualized carboplatin doses were calculated to achieve a target area under the concentration x time curve (AUC) and adjusted for the glomerular filtration rate (estimated by 99mTc-labeled diethylene-triamine pentaacetic acid clearance). Cohorts of at least three patients received carboplatin at an initial target AUC of 6 mg.min/mL, with escalations of 2 mg.min/mL in subsequent cohorts. Carboplatin was given on day 1, followed by ifosfamide at 2 g/m2 per day and etoposide at 100 mg/m2 per day on days 2 through 4. All patients received at least two courses of therapy in the absence of progressive disease, and as many as eight courses could be given. RESULTS: The 15 patients received a total of 46 assessable courses of ICE. Myelosuppression was the dominant toxicity; 30 courses (67%) resulted in hospitalization for febrile neutropenia. Neutropenia was dose limiting at the carboplatin target AUC of 12 mg.min/mL. One complete and eight partial responses were seen in the 14 assessable patients; two additional patients had at least partial responses documented at surgery or autopsy. Six patients are without evidence of disease at a median of 548 days after diagnosis. CONCLUSION: ICE chemotherapy, with the carboplatin dose based on a target AUC of 10 mg.min/mL, is tolerable and has significant activity in a variety of rare malignancies, including extragonadal germ cell tumors. IMPLICATIONS: The combination of carboplatin, etoposide, and ifosfamide holds promise in the treatment of rare pediatric malignancies.

Catabolism of rat surfactant disaturated phosphatidylcholines during incubation of alveolar lavage materials in vitro at 37 degrees C.

Incubation of rat alveolar lavage materials in vitro at 37 degrees C results in degradation of the endogenous surfactant disaturated phosphatidylcholines (disaturated PC). When exogenous dipalmitoylphosphatidylcholine (DPPC) vesicles are incubated with lavage materials, there is catabolism of the DPPC. The degradation process is temperature- and Ca2+-dependent and has a pH optimum of 6.5-7.0. The products formed during catabolism of [3H]palmitate- and [14C]choline-labeled disaturated PC are free palmitate and water-soluble choline products. No lysophosphatidylcholines are formed. Measurements of lactate dehydrogenase levels in lavage fluid, use of more gentle lavage techniques, use of Ca2+, Mg2+ and protein in the lavage medium, and measurements of bacterial contamination all suggest that enzymes are neither released into pulmonary lavage fluid via cellular damage nor are bacterial in origin. Degradation of surfactant disaturated PC does not occur during incubation of lavage materials from rabbits, mice or guinea pigs. These results suggest that phospholipases and/or lysophospholipases are present in rat alveolar lavage materials. Possible origins of these enzymes are discussed.

Incorporation of [3H]palmitate and [14C]choline into disaturated phosphatidylcholines in rat alveolar macrophages.

We studied the synthesis of disaturated phosphatidylcholines in rat alveolar macrophages and, in some cases, compared it with that which occurs in isolated alveolar type II cells. Alveolar macrophages suspended in phosphate-buffered medium incorporate palmitate, choline and glycerol into disaturated phosphatidylcholines. The time-course for incorporation of palmitate into disaturated phosphatidylcholines is linear for 20-30 min and reaches a maximum in 2-3 h. Incorporation is dependent on extracellular palmitate with a Vmax (at 1 mM) of 1.53 nmol palmitate incorporated into disaturated phosphatidylcholines per 5 X 10(5) cells per 2 h and a K 1/2 of 0.19 mM palmitate. Exposure of the cells to zymosan particles increases incorporation of palmitate disaturated phosphatidylcholines by almost 2-fold, while cholinergic and beta-adrenergic agonists have no effect. On a per cell basis, alveolar macrophages incorporate only one-third to one-half as much palmitate into disaturated phosphatidylcholines as do type II cells isolated by centrifugal elutriation. The following results suggest there is extensive remodeling of disaturated phosphatidylcholines in alveolar macrophages: (1) palmitate- and choline-labeled disaturated phosphatidylcholines are catabolized by the cells; (2) the products of catabolism are palmitate and water-soluble choline products; (3) addition of unlabeled palmitate and choline to the medium enhances catabolism of the labeled phospholipid. Addition of oleate also enhances catabolism, suggesting that modification of phospholipids is not specific for the saturated variety. Some of the recently labeled disaturated phosphatidylcholines is released from alveolar macrophages into the extracellular space. Several possible functions of alveolar macrophage disaturated phosphatidylcholines are discussed.

Carbon tetrachloride inhibits synthesis of pulmonary surfactant disaturated phosphatidylcholines and ATP production in alveolar type II cells.

Other studies have shown that inhalation of carbon tetrachloride (CCl4) decreases the amount of pulmonary surfactant lining the alveolar surface. Therefore, we studied the effects of CCl4 on the synthesis of surfactant phosphatidylcholines (PCs) in rat alveolar type II cells in vitro. The rate of incorporation of choline, palmitate or glycerol into disaturated PC (DSPC) is decreased in a concentration-dependent manner. The CCl4 concentrations which cause maximal inhibition and 50% inhibition are similar for each substrate. The rate of incorporation of choline or glycerol into total PC is diminished to the same extent as their incorporation into DSPC. In addition, the rate of incorporation of glycerol into phosphatidylglycerol is decreased by the same extent as its incorporation into PC. All of these data suggest that there is a common site(s) at which CCl4 inhibits PC synthesis and that the inhibition occurs early in the biosynthetic pathway. However, individual enzymes involved in phospholipid synthesis do not seem to be affected by the solvent. Exposure of alveolar type II cells to CCl4 does cause a rapid and dramatic loss in cellular ATP, a cofactor required by some enzymes involved in PC synthesis. Studies with isolated lung mitochondria suggest that CCl4 inhibits the enzyme complex which catalyzes the synthesis of ATP from ADP. In addition, CCl4 causes a decrease in the amount of 3-O-methylglucose associated with type II cells, suggesting that glucose influx is impaired. This may also contribute to lower cellular ATP levels. The results of this study suggest that inhalation of CCl4 may impair surfactant phospholipid synthesis by decreasing ATP levels in alveolar type II cells.

Incorporation of [3H]palmitate into disaturated phosphatidylcholines in alveolar type II cells isolated by centrifugal elutriation.

In order to study synthesis of pulmonary surfactant materials, we measured incorporation of [3H]palmitate into disaturated phosphatidylcholines (PC) in alveolar type II cells isolated by centrifugal elutriation. The time course for this process is not linear and, at high external palmitate levels (1 mM), incorporation is maximal in 4-5 h. Incorporation is dependent on extracellular palmitate with a Vmax (at 1 mM) of 1.66 nmol palmitate incorporated into disaturated PC/4.2 X 10(5) cells per 2 h and a K1/2 of 0.1 mM palmitate. Addition of an optimal amount of extracellular choline (0.05 mM) increases Vmax and decreases K1/2 for palmitate. Incorporation of palmitate is dependent upon cell number, inhibited by extracellular Ca2+ and stimulated by external Mg2+. Cholinergic and beta-adrenergic agonists do not increase incorporation. Pulmonary lavage fluid inhibits incorporation of palmitate into disaturated PC, suggesting there is negative feedback involved. Disaturated PC which has been recently synthesized (i.e., over a 2 h period) is broken down intracellularly by type II cells when they are suspended in palmitate-free medium. These results indicate that (1) several factors, such as substrate levels, cell number, Ca2+, Mg2+ and amount of surfactant present, are involved in the regulation of palmitate incorporation into disaturated PC; (2) disaturated PC which has been recently synthesized may be broken down by type II cells; and (3) surfactant synthesis in freshly isolated cells differs slightly from that reported by other investigators in type II cells maintained in primary cell culture.