Impact of thoracic radiotherapy timing in limited-stage small-cell lung cancer: usefulness of the individual patient data meta-analysis

BACKGROUND

Chemotherapy (CT) combined with radiotherapy is the standard treatment of 'limited-stage' small-cell lung cancer. However, controversy persists over the optimal timing of thoracic radiotherapy and CT.

MATERIALS AND METHODS

We carried out a meta-analysis of individual patient data in randomized trials comparing earlier versus later radiotherapy, or shorter versus longer radiotherapy duration, as defined in each trial. We combined the results from trials using the stratified log-rank test to calculate pooled hazard ratios (HRs). The primary outcome was overall survival.

RESULTS

Twelve trials with 2668 patients were eligible. Data from nine trials comprising 2305 patients were available for analysis. The median follow-up was 10 years. When all trials were analysed together, 'earlier or shorter' versus 'later or longer' thoracic radiotherapy did not affect overall survival. However, the HR for overall survival was significantly in favour of 'earlier or shorter' radiotherapy among trials with a similar proportion of patients who were compliant with CT (defined as having received 100% or more of the planned CT cycles) in both arms (HR 0.79, 95% CI 0.69-0.91), and in favour of 'later or longer' radiotherapy among trials with different rates of CT compliance (HR 1.19, 1.05-1.34, interaction test, P < 0.0001). The absolute gain between 'earlier or shorter' versus 'later or longer' thoracic radiotherapy in 5-year overall survival for similar and for different CT compliance trials was 7.7% (95% CI 2.6-12.8%) and -2.2% (-5.8% to 1.4%), respectively. However, 'earlier or shorter' thoracic radiotherapy was associated with a higher incidence of severe acute oesophagitis than 'later or longer' radiotherapy.

CONCLUSION

'Earlier or shorter' delivery of thoracic radiotherapy with planned CT significantly improves 5-year overall survival at the expense of more acute toxicity, especially oesophagitis.

Clinical Case of the Month: A 64 Year-Old Woman Presenting With Fever, Confusion, Ophthalmoplegia and Pneumonia

Legionella pneumophila is a major cause of atypical community-acquired pneumonia, which is commonly severe enough to require hospitalization. Though primarily a respiratory infection, Legionellosis involves the central nervous system (CNS) in up to 50% of patients, and diagnosis can be obscured by the absence of obvious respiratory symptomatology. A reversible diffuse encephalopathy is the most common neurologic complication, but focal CNS involvement can sometimes be the initial presentation. We report a case of a woman infected with Legionella pneumophila presenting with vague symptomatology and focal neurologic findings. This report highlights the challenges of early recognition of Legionella infection when neurologic symptoms predominate.

Phenome-wide Association Study Relating Pretreatment Laboratory Parameters With Human Genetic Variants in AIDS Clinical Trials Group Protocols

Background.  Phenome-Wide Association Studies (PheWAS) identify genetic associations across multiple phenotypes. Clinical trials offer opportunities for PheWAS to identify pharmacogenomic associations. We describe the first PheWAS to use genome-wide genotypic data and to utilize human immunodeficiency virus (HIV) clinical trials data. As proof-of-concept, we focused on baseline laboratory phenotypes from antiretroviral therapy-naive individuals. Methods.  Data from 4 AIDS Clinical Trials Group (ACTG) studies were split into 2 datasets: Dataset I (1181 individuals from protocol A5202) and Dataset II (1366 from protocols A5095, ACTG 384, and A5142). Final analyses involved 2547 individuals and 5 954 294 imputed polymorphisms. We calculated comprehensive associations between these polymorphisms and 27 baseline laboratory phenotypes. Results.  A total of 10 584 (0.17%) polymorphisms had associations with P < .01 in both datasets and with the same direction of association. Twenty polymorphisms replicated associations with identical or related phenotypes reported in the Catalog of Published Genome-Wide Association Studies, including several not previously reported in HIV-positive cohorts. We also identified several possibly novel associations. Conclusions.  These analyses define PheWAS properties and principles with baseline laboratory data from HIV clinical trials. This approach may be useful for evaluating on-treatment HIV clinical trials data for associations with various clinical phenotypes.

Nuclear imaging: a powerful novel approach for tuberculosis

Nearly 20 years after the World Health Organization declared tuberculosis (TB) a global public health emergency, TB still remains a major global threat with 8.6 million new cases and 1.3 million deaths annually. Mycobacterium tuberculosis adapts to a quiescent physiological state, and is notable for complex interaction with the host, producing poorly-understood disease states ranging from latent infection to fully active disease. Of the approximately 2.5 billion people latently infected with M. tuberculosis, many will develop reactivation disease (relapse), years after the initial infection. While progress has been made on some fronts, the alarming spread of multidrug-resistant, extensively drug-resistant, and more recently totally-drug resistant strains is of grave concern. New tools are urgently needed for rapidly diagnosing TB, monitoring TB treatments and to allow unique insights into disease pathogenesis. Nuclear bioimaging is a powerful, noninvasive tool that can rapidly provide three-dimensional views of disease processes deep within the body and conduct noninvasive longitudinal assessments of the same patient. In this review, we discuss the application of nuclear bioimaging to TB, including the current state of the field, considerations for radioprobe development, study of TB drug pharmacokinetics in infected tissues, and areas of research and clinical needs that could be addressed by nuclear bioimaging. These technologies are an emerging field of research, overcome several fundamental limitations of current tools, and will have a broad impact on both basic research and patient care. Beyond diagnosis and monitoring disease, these technologies will also allow unique insights into understanding disease pathogenesis; and expedite bench-to-bedside translation of new therapeutics. Finally, since molecular imaging is readily available for humans, validated tracers will become valuable tools for clinical applications.

Genome-wide association study of peripheral neuropathy with D-drug-containing regimens in AIDS Clinical Trials Group protocol 384

Stavudine (d4T) was, until recently, one of the most widely prescribed antiretroviral drugs worldwide. While there has been a major shift away from d4T use in resource-limited countries, a large number of patients have previously received (or continue to receive) d4T, and many have developed peripheral neuropathy. The identification of genetic predictors of increased risk might suggest novel therapeutic targets for such patients. In AIDS Clinical Trials Group protocol 384, antiretroviral-naïve patients were randomized to d4T/didanosine (ddI)- or zidovudine/lamivudine-containing regimens. Data from d4T/ddI recipients were analyzed for genome-wide associations (approximately 1 million genetic loci) with new onset distal sensory peripheral neuropathy. Analyses involved 254 patients (49 % White, 34 % Black, 17 % Hispanic), comprising 90 peripheral neuropathy cases (32 grade 1, 35 grade 2, 23 grade 3) and 164 controls. After correcting for multiple comparisons, no polymorphism was consistently associated with neuropathy among all patients, among White, Black, and Hispanic patients analyzed separately, both in genome-wide analyses (threshold, P < 5.0 × 10⁻⁸) and focused on 46 neuropathy-associated genes (threshold, P < 3.5 × 10⁻⁵). In the latter analyses, the lowest P values were in KIF1A among Whites (rs10199388, P = 8.4 × 10⁻⁴), in LITAF among Blacks (rs13333308, P = 6.0 × 10⁻⁶), and in NEFL among Hispanics (rs17763685, P = 5.6 × 10⁻⁶). Susceptibility to d4T/ddI-associated neuropathy is not explained by a single genetic variant with a marked effect.

Genetic and non-genetic determinants of raltegravir penetration into cerebrospinal fluid: a single arm pharmacokinetic study

Background

Antiretroviral drugs vary in their central nervous system penetration, with better penetration possibly conferring neurocognitive benefit during human immunodeficiency virus (HIV) therapy. The efflux transporter gene ABCB1 is expressed in the blood-brain barrier, and an ABCB1 variant (3435C→T) has been reported to affect ABCB1 expression. The integrase inhibitor raltegravir is a substrate for ABCB1. We examined whether ABCB1 3435C→T affects raltegravir disposition into cerebrospinal fluid (CSF), and explored associations with polymorphisms in other membrane transporter genes expressed in the blood-brain barrier.

Methods

Forty healthy, HIV-negative adults of European descent (20 homozygous for ABCB1 3435 C/C, 20 homozygous for 3435 T/T, each group divided equally between males and females) were given raltegravir 400 mg twice daily for 7 days. With the final dose, plasma was collected for pharmacokinetic analysis at 9 timepoints over 12 hours, and CSF collected 4 hours post dose.

Results

The 4-hour CSF concentration correlated more strongly with 2-hour (r²=0.76, P=1.12x10^-11) than 4-hour (r²=0.47, P=6.89x10^-6) single timepoint plasma concentration, and correlated strongly with partial plasma area-under-the-curve values (AUC_0-4h r²=0.86, P=5.15x10^-16). There was no significant association between ABCB1 3435C→T and ratios of CSF-to-plasma AUC or concentration (p>0.05 for each comparison). In exploratory analyses, CSF-to-plasma ratios were not associated with 276 polymorphisms across 16 membrane transporter genes.

Conclusions

Among HIV-negative adults, CSF raltegravir concentrations do not differ by ABCB1 3435C→T genotype but strongly correlate with plasma exposure.

Trial Registration

ClinicalTrials.gov NCT00729924 http://clinicaltrials.gov/show/NCT00729924

Neuropsychometric correlates of efavirenz pharmacokinetics and pharmacogenetics following a single oral dose

AIMS

To determine pharmacokinetic and pharmacogenomic correlates of efavirenz central nervous system (CNS) side effects following a single dose.

METHODS

Thirty-four healthy HIV-negative African Americans were administered a 600 mg dose of efavirenz. Blood samples for pharmacokinetics were drawn serially from 0 to 12 h post-dose. Neuropsychometric testing with drowsiness visual analogue scale, grooved pegboard and letter digit substitution tests was done the day prior to dosing and at 1, 2, 3, 4 and 6 h post-dose. Subjective CNS symptoms were assessed at 6 h post-dose. Composite CYP2B6 516/983 genotype was determined.

RESULTS

Pharmacokinetic indices reflecting increased plasma efavirenz exposure were associated with slower non-dominant hand grooved pegboard task completion (Cmax , P1 h  = 0.01, P2 h  = 0.05, P3 h  = 0.03, P4 h  = 0.01; AUC, P1 h  = 0.04; clearance P1 h  = 0.05, P2 h  = 0.02, P6 h  = 0.01). In a repeated measures model analysis that adjusted timing of neuropsychometric testing for timing of peak drug concentration, clearance (P < 0.001), AUC(0.312 h) (P = 0.001) and Cmax (P = 0.008) were associated with non-dominant grooved pegboard test performance. CYP2B6 genotype trended to correlate with non-dominant hand grooved pegboard at 4 and 6 h (P = 0.07 and 0.06). Decreased drowsiness at 6 h was associated with higher Cmax (P = 0.02).

CONCLUSIONS

Following a single dose of efavirenz, an association between pharmacokinetics and neuropsychometric performance was discernable. A weaker association between genotype and neurocognitive test performance is likely mediated by effect of genotype on plasma clearance. Strategies that lower Cmax during initial dosing may decrease CNS side effects.

Baseline tumour measurements predict survival in advanced non-small cell lung cancer

BACKGROUND

The association between tumour measurements and survival has been studied extensively in early-stage and locally advanced non-small cell lung cancer (NSCLC). We analysed these factors in patients with advanced NSCLC.

METHODS

Data were derived from the E4599 trial of paclitaxel-carboplatin±bevacizumab. Associations between the Response Evaluation Criteria in Solid Tumors (RECIST) baseline sum longest diameter (BSLD), response rate, progression-free survival (PFS) and overall survival (OS) were evaluated using univariate and multivariable Cox regression models.

RESULTS

A total of 759 of the 850 patients (89%) in the E4599 trial had measurable diseases and were included in this analysis. The median BSLD was 7.5 cm. BSLD predicted OS (hazard ratio (HR) 1.41; P<0.001) and had a trend towards association with PFS (HR 1.14; P=0.08). The median OS was 12.6 months for patients with BSLD <7.5 cm compared with 9.5 months for BSLD ≥ 7.5 cm. This association persisted in a multivariable model controlling multiple prognostic factors, including the presence and sites of extrathoracic disease (HR 1.24; P=0.01). There was no association between BSLD and response rate.

CONCLUSION

Tumour measurements are associated with survival in the E4599 trial. If validated in other populations, this parameter may provide important prognostic information to patients and clinicians.

Multisite EPR oximetry from multiple quadrature harmonics

Multisite continuous wave (CW) electron paramagnetic resonance (EPR) oximetry using multiple quadrature field modulation harmonics is presented. First, a recently developed digital receiver is used to extract multiple harmonics of field modulated projection data. Second, a forward model is presented that relates the projection data to unknown parameters, including linewidth at each site. Third, a maximum likelihood estimator of unknown parameters is reported using an iterative algorithm capable of jointly processing multiple quadrature harmonics. The data modeling and processing are applicable for parametric lineshapes under nonsaturating conditions. Joint processing of multiple harmonics leads to 2-3-fold acceleration of EPR data acquisition. For demonstration in two spatial dimensions, both simulations and phantom studies on an L-band system are reported.

Transretinal degeneration in ageing human retina: a multiphoton microscopy analysis

AIM

Retinal cell remodelling has been reported as a consistent feature of ageing. However, the degree to which this results in transretinal degeneration is unclear. To address this, the authors used multiphoton microscopy to quantify retinal degeneration in post-mortem human eyes of two age groups.

METHODS

Retinas from six young subjects (18-33 years old) and six older subjects (74-90 years old) were prepared as wholemount preparations. All retinas were stained with 4,6-diamidino-2-phenylindole and imaged by multiphoton confocal microscopy to quantify neuron densities in the retinal ganglion cell layer (RGCL), inner nuclear layer (INL) and outer nuclear layer (ONL). Neurons were counted using automated cell identification algorithms. All retinas were imaged hydrated to minimise tissue artefacts.

RESULTS

In both groups, 56% of the area within the central 4 mm eccentricity and 27% of the area with eccentricity between 4 mm and 7 mm were imaged. Compared with young subjects, the peak RGCL neuron loss in the aged subjects (25.5%) was at 1 mm eccentricity. INL and ONL neuron densities significantly decreased at 1-2 mm eccentricity (8.7%) and 0.5-4 mm eccentricity (15.6%) respectively (P <0.05). The reduction in neuron density in the INL corresponded, spatially, to the region with the greatest neuron loss in the RGCL and ONL.

CONCLUSIONS

This is the first study to correlate neurodegeneration in different populations of cells in the ageing retinas. These data confirm that the greatest neuronal loss occurs in the RGCL and ONL in human ageing retinas, whereas the INL is relatively preserved.

Evidence for viable, non-clonal but fatherless Boa constrictors

Parthenogenesis in vertebrates is considered an evolutionary novelty. In snakes, all of which exhibit genetic sex determination with ZZ : ZW sex chromosomes, this rare form of asexual reproduction has failed to yield viable female WW offspring. Only through complex experimental manipulations have WW females been produced, and only in fish and amphibians. Through microsatellite DNA fingerprinting, we provide the first evidence of facultative parthenogenesis in a Boa constrictor, identifying multiple, viable, non-experimentally induced females for the first time in any vertebrate lineage. Although the elevated homozygosity of the offspring in relation to the mother suggests that the mechanism responsible may be terminal fusion automixis, no males were produced, potentially indicating maternal sex chromosome hemizygosity (WO). These findings provide the first evidence of parthenogenesis in the family Boidae (Boas), and suggest that WW females may be more common within basal reptilian lineages than previously assumed.

Oncogenic mutations regulate tumor microenvironment through induction of growth factors and angiogenic mediators

Activating mutations in the tyrosine kinase domain of HER2 (ErbB2) have been identified in human cancers. Compared to wild-type HER2, mutant HER2 shows constitutively activate kinase activity and increased oncogenicity. Cells transformed by mutant HER2 are resistant to EGFR tyrosine kinase inhibitors and exhibit an attenuated response to the HER2 antibody trastuzumab. We investigated herein pathways through which mutant HER2 alters the extracellular environment, potentially leading to drug resistance and the effect of simultaneously targeting HER2 and the tumor cell microenvironment with a therapeutic intent. Expression of mutant HER2 in mammary epithelial cells activated autocrine transforming growth factor (TGF) β1 signaling through a mechanism involving Rac1 and JNK-AP1-dependent transcription. Cells transformed by an activating mutant of H-Ras (G12V) also expressed higher TGF-β1 level through Rac1 activation. In addition, mutant HER2 induced the EGFR ligands TGF-α and amphiregulin at the mRNA and protein levels. Vascular endothelial growth factor (VEGF), a target of the TGF-β-Smad transcriptional regulation, was also induced as a result of expression of mutant HER2. Inhibition of TGF-β signaling with the Alk5 small molecule inhibitor LY2109761 reduced growth and invasiveness of cells expressing mutant HER2. Combined inhibition of intracellular and paracrine effects of mutant HER2 by trastuzumab and the EGFR antibody cetuximab was more efficient than single-agent therapies. These data suggest that mutations in oncogenes such as HER2 and Ras not only alter intracellular signaling and also influence on other components of the tumor microenvironment by inducing several pro-invasive growth factors. In turn, these serve as extracellular targets of novel therapeutic strategies directed at both cancer-driving oncogenes and the modified tumor microenvironment.

Adjuvant chemotherapy, with or without postoperative radiotherapy, in operable non-small-cell lung cancer: two meta-analyses of individual patient data

BACKGROUND

Many randomised controlled trials have investigated the effect of adjuvant chemotherapy in operable non-small-cell lung cancer. We undertook two comprehensive systematic reviews and meta-analyses to establish the effects of adding adjuvant chemotherapy to surgery, or to surgery plus radiotherapy.

METHODS

We included randomised trials, not confounded by additional therapeutic differences between the two groups and that started randomisation on or after Jan 1, 1965, which compared surgery plus adjuvant chemotherapy versus surgery alone, or surgery plus adjuvant radiotherapy and chemotherapy versus surgery plus adjuvant radiotherapy. Updated individual patient data were collected, checked, and included in meta-analyses stratified by trial. The primary endpoint was overall survival, defined as time from randomisation until death by any cause. All analyses were by intention to treat.

FINDINGS

The first meta-analysis of surgery plus chemotherapy versus surgery alone was based on 34 trial comparisons and 8447 patients (3323 deaths). We recorded a benefit of adding chemotherapy after surgery (hazard ratio [HR] 0.86, 95% CI 0.81-0.92, p<0.0001), with an absolute increase in survival of 4% (95% CI 3-6) at 5 years (from 60% to 64%). The second meta-analysis of surgery plus radiotherapy and chemotherapy versus surgery plus radiotherapy was based on 13 trial comparisons and 2660 patients (1909 deaths). We recorded a benefit of adding chemotherapy to surgery plus radiotherapy (HR 0.88, 95% CI 0.81-0.97, p=0.009), representing an absolute improvement in survival of 4% (95% CI 1-8) at 5 years (from 29% to 33%). In both meta-analyses we noted little variation in effect according to the type of chemotherapy, other trial characteristics, or patient subgroup.

INTERPRETATION

The addition of adjuvant chemotherapy after surgery for patients with operable non-small-cell lung cancer improves survival, irrespective of whether chemotherapy was adjuvant to surgery alone or adjuvant to surgery plus radiotherapy.

FUNDING

UK Medical Research Council, Institut Gustave-Roussy, Programme Hospitalier de Recherche Clinique (AOM 05 209), Ligue Nationale Contre le Cancer, and Sanofi-Aventis.

Topography of neuron loss in the retinal ganglion cell layer in human glaucoma

AIM

To determine if retinal ganglion cell (RGC) loss influences the loss of surrounding RGCs to generate clustered patterns of cell death in human glaucoma. It is hypothesised that retinal ganglion cell loss accelerates the loss of surrounding cells to generate, at a local, cellular scale, clustered patterns of retinal of RGC death. The absence of these interactions would result in a diffuse pattern RGC loss.

METHOD

Six glaucomatous retinas (67-83 years old) and six age-matched control retinas (61-89 years old) were prepared as wholemounts and stained by 4',6-diamidino-2-phenylindole (DAPI) solution (3 microg/ml in PBS). An area corresponding to central 14 degrees of the visual field was imaged. The nearest-neighbour distribution was determined for cells in both normal and glaucomatous RGCL.

RESULTS

Clustered RGC loss in human glaucoma was observed on a background of diffuse loss. The mean nearest-neighbour distance (NND) of the glaucomatous retinas was significantly higher than with controls (p<0.001). The distribution of NND in glaucomatous retinas was skewed to the higher values with a higher positive kurtosis relative to controls. The quantitative analysis of the pattern of cell loss is supported by the visual inspection of the patterns of cell loss.

DISCUSSION

The nearest-neighbour analysis is consistent with the presence of two patterns of cell loss in the RGCL in glaucoma. While the diffuse of cell loss can account for an overall reduction in the RGC population, an additional non-random pattern is consistent with the hypothesis that RGC loss has a local influence on the viability of surrounding cells.

Predicting gene promoter methylation in non-small-cell lung cancer by evaluating sputum and serum

The use of 5-methylcytosine demethylating agents in conjunction with inhibitors of histone deacetylation may offer a new therapeutic strategy for lung cancer. Monitoring the efficacy of gene demethylating treatment directly within the tumour may be difficult due to tumour location. This study determined the positive and negative predictive values of sputum and serum for detecting gene methylation in primary lung cancer. A panel of eight genes was evaluated by comparing methylation detected in the primary tumour biopsy to serum and sputum obtained from 72 patients with Stage III lung cancer. The prevalence for methylation of the eight genes in sputum (21–43%) approximated to that seen in tumours, but was 0.7–4.3-fold greater than detected in serum. Sputum was superior to serum in classifying the methylation status of genes in the tumour biopsy. The positive predictive value of the top four genes (p16, DAPK, PAX5 β, and GATA5) was 44–72% with a negative predictive value for these genes ⩾70%. The highest specificity was seen for the p16 gene, and this was associated with a odds ratio of six for methylation in the tumour when this gene was methylated in sputum. In contrast, for serum, the individual sensitivity for all genes was 6–27%. Evaluating the combined effect of methylation of at least one of the four most significant genes in sputum increased the positive predictive value to 86%. These studies demonstrate that sputum can be used effectively as a surrogate for tumour tissue to predict the methylation status of advanced lung cancer where biopsy is not feasible.

Gene therapy for breast and ovarian cancer with BRCA1

As an initial step toward gene therapy for ovarian cancer, we conducted a Phase 1 trial to assess the pharmacokinetics and toxicity of intraperitoneal BRCA1sv retroviral vector therapy. Gene transfer and expression were documented by PCR, southern blot, RT-PCR and nuclease protection assays. Pharmacokinetics were assessed by PCR and southern blots detecting vector DNA, and toxicity was evaluated by clinical exam and fluid analysis. Three of twelve patients developed an acute sterile peritonitis which spontaneously resolved within 48 hours. Plasma and peritoneal antibodies to the retroviral envelope protein were detected only in patients treated with the highest dose levels but not in others, despite repeat dosing for an interval of up to four months. Eight patients showed stable disease for 4 to 16 weeks. Three patients showed tumor reduction with diminished miliary tumor implants at reoperation (two patients) and radiographic shrinkage of measurable disease (one patient). Ovarian cancer may provide an imporant model for retroviral gene therapy studies due to vector stability, minimal antibody response, and access to tumor by intraperitoneal therapy.

Phase II study of the farnesyl transferase inhibitor R115777 in patients with sensitive relapse small-cell lung cancer

BACKGROUND

R115777 (tipifarnib, Zarnestra) is a farnesyl transferase inhibitor that blocks the farnesylation of proteins involved in signal transduction pathways critical for cell proliferation and survival. This multicenter phase II study was conducted to determine the efficacy, tolerability and pharmacokinetics of R115777 in patients with relapsed small-cell lung cancer (SCLC).

PATIENTS AND METHODS

Patients who had a partial or complete response to their initial chemotherapy regimen, followed by at least 3 months off treatment before relapse (sensitive relapse) were eligible. R115777 was administered in 3-week cycles at a dose of 400 mg orally twice daily for 14 consecutive days followed by 7 days off treatment.

RESULTS

Twenty-two patients were enrolled. The median progression-free survival was 1.4 months and median overall survival was 6.8 months. Non-hematological toxicities were predominantly grade 1-2 and included nausea (64%) and fatigue (60%). Grade 3-4 granulocytopenia and thrombocytopenia occurred in 27% and 23% of patients, respectively. Febrile neutropenia was not observed. Pharmacokinetic studies demonstrated peak plasma concentrations of R115777 2.6-4.5 h after oral dosing and no significant drug accumulation. The trial was terminated because no objective responses were observed in 20 patients evaluable for response.

CONCLUSIONS

R115777 showed no significant antitumor activity as a single agent in sensitive-relapse SCLC.

Mutations which enhance the replication of dengue virus type 4 and an antigenic chimeric dengue virus type 2/4 vaccine candidate in Vero cells

Mutations which increase the replication of dengue viruses in cell culture would greatly facilitate the manufacture of both a live attenuated or inactivated dengue virus vaccine. We have identified eight missense mutations in dengue virus type 4 (DEN4) that increase the plaque size and kinetics of replication of recombinant DEN4 virus in Vero cells. DEN4 viruses bearing these Vero cell adaptation mutations were also evaluated for the level of replication in the brains of mice. Two of these eight recombinant viruses expressing distinct mutations in NS3 were both restricted in replication in the brains of suckling mice. In contrast, six recombinant viruses, each encoding individual mutations in NS4B (five) or in NS5 (one), were not attenuated in mouse brain. Recombinant viruses encoding various combinations of these Vero cell adaptation mutations did not demonstrate enhanced replication in Vero cells over that exhibited by the single mutations. Finally, addition of a subset of the above non-attenuating, adaptation mutations to a DEN2/4 chimeric vaccine candidate was found to increase the virus yield in Vero cells by up to 500-fold. The importance of these Vero cell adaptation mutations in flavivirus vaccine design and development is discussed.

Chondroblastoma of the temporal bone involving the temporomandibular joint, mandibular condyle, and middle cranial fossa: case report and review of the literature

Chondroblastoma is a highly destructive tumor, derived from immature cartilage cells, typically occurring in epiphyses of the long bones of adolescents and young adults. Those occurring in the temporal bone and TMJ area are likely to mimic TMJ symptoms. This report describes a unique case in which a chondroblastoma resulted in extensive destruction of the temporal bone, temporomandibular joint, mandibular condyle, and cranial base, including gross intracranial and extracranial involvement. With appropriate surgical management, the outcome for patients with chondroblastoma of the temporomandibular region is quite favorable. This case brings the total reported chondroblastomas to 59 in the temporal bone and eight in the mandibular condyle as of the date of submission of this article for publication.

Docetaxel Combined With Trastuzumab Is an Active Regimen in HER-2 3+ Overexpressing and Fluorescent In Situ Hybridization–Positive Metastatic Breast Cancer: A Multi-Institutional Phase II Trial

Purpose

To determine the efficacy and safety of weekly docetaxel and trastuzumab as first- or second-line therapy in women with HER-2–overexpressing metastatic breast cancer and to correlate the efficacy of trastuzumab with HER-2 status as determined by immunohistochemistry assay and fluorescent in situ hybridization (FISH).

Patients and Methods

Twenty-six women with HER-2–positive (HercepTest [Dako Corp, Carpenteria, CA]2 to 3+) metastatic breast cancer were enrolled onto this study of trastuzumab (4 mg/kg load; 2 mg/kg/wk administered intravenously) and docetaxel (35 mg/m2/wk for 6 weeks).

Results

Using an intent-to-treat analysis, the overall response rate was 50% (13 of 26 patients). Eight patients (31%) had a period of stable disease posttherapy. Among HER-2 3+ patients, the overall response rate was 63% (12 of 19 patients) compared with a 14% response rate (one of seven patients) for HER-2 2+ patients (P = .07). Patients with FISH-positive tumors experienced an overall response rate of 64%. Median time to progression was 12.4 months for the entire cohort (HER-2 3+ tumors, 12.3 months; HER-2 2+ lesions, 9.5 months) and median survival was 22.1 months. All HER-2 3+ patients were FISH-positive; the only HER-2 2+ patient responding to treatment was also FISH-positive. Grade 4 toxicities occurred in four patients; most toxicities were mild.

Conclusion

Trastuzumab plus docetaxel is an active and well-tolerated regimen in women with HER-2 3+ overexpressing or FISH-positive metastatic breast cancer.

Docetaxel and cisplatin in patients with advanced non small-cell lung cancer (NSCLC): a multicenter phase II trial

We examined the safety and efficacy of the docetaxel/cisplatin combination in patients with advanced, previously untreated NSCLC and evaluated changes in quality of life over time. Docetaxel was administered before cisplatin (both 75 mg/m2, 1-hour infusions) every 3 weeks to 47 patients with stage IIIB or stage IV NSCLC. Patients also received premedication of oral dexamethasone. The median age (range) of patients was 62 (45-78) years and 26 patients (55.3%) had adenocarcinoma. Of the 40 patients evaluable for response, one achieved a complete response and 14 had partial responses; the response rate was 37.5% (95% confidence intervals; 22.5, 52.5). In the intent-to-treat population the overall response rate was 31.9%. Time to response ranged from 3 to 20 weeks, and the median duration of response was 34.6 weeks. Median survival and median time to progression were 11.3 months and 18.9 weeks, respectively. One-year survival was 40%. Grade 3 or 4 neutropenia and febrile neutropenia were observed in 74.4% and 12.8% of patients, respectively. Severe asthenia was seen in 14.9% of patients. Other grade 3 or 4 toxicities included nausea (eight patients), vomiting (five), neurosensory effects (six), neuromotor effects (five), diarrhea (four), and infection (three). There was an improvement in emotional well-being; however, the overall quality of life score did not change with treatment. Docetaxel administered in combination with cisplatin is an active regimen in patients with NSCLC. This regimen of docetaxel (75 mg/m2) and cisplatin (75 mg/m2) repeated at 3-week intervals is being evaluated in an ongoing Eastern Cooperative Oncology Group (ECOG) randomized study in patients with advanced and metastatic NSCLC.

Visual responses of crayfish ocular motoneurons: an information theoretical analysis

Motoneuron responses were elicited by global visual motion and stepwise displacements of an illuminated stripe. Stimulus protocols were identical to those used in previous behavioral studies of compensatory eyestalk reflexes. The firing rates and directional selectivity of the motoneuron responses were measured with respect to four stimulus dimensions (spatial frequency, contrast, angular displacement and velocity). The directional selectivity of the motoneuron response was correlated to the previously measured gain of the reflex for each stimulus dimension. The information theoretical analysis is based upon Kullback-Leibler (K-L) distances which measure the dissimilarity of responses to different stimuli. K-L distances for single neurons are strongly influenced by the mean rate difference of the responses to any pair of stimuli. Because of redundancy, the joint K-L distances of pairs of neurons were less than the sum of the K-L distances of the individual neurons. Furthermore, the joint K-L distances were only weakly influenced by correlations among coactivated neurons. For most of the stimulus dimensions, the K-L distances of single motoneurons were not sufficient to account for the stimulus discriminations exhibited by the eyestalk reflex which typically required the summed output of 2 to 5 motoneurons. Thus the behaviorally relevant information is encoded in the motoneuron ensemble. The minimum time required to discriminate the direction of motion (the encoding window) for a single motoneuron is about 380 to 480 ms (including a 175 ms response latency) for stepwise displacements and up to 1.0 s for global motion. During this period a motoneuron fires 2 to 3 impulses.

Mortality during hospitalisation for pneumonia in Alberta, Canada, is associated with physician volume

The association of mortality with patient factors (severity of illness, comorbidity), physician factors (specialty training, prehospitalisation visit, in-hospital consultation, volume of patients seen per physician) and healthcare organisation factors (patient-travel distances, regional beds per capita, admitting hospital-bed occupancy, admitting hospital-bed turnover, hospital location, volume of pneumonia cases per hospital) after hospital admission with community-acquired pneumonia was investigated using administrative data from Alberta, Canada from April 1, 1994-March 31, 1999. During the 5-yr study period there were 43,642 pneumonia hospitalisations, with an 11% in-hospital and 26% 1-yr mortality. Patient severity of illness and comorbidity were the strongest predictors of increased mortality. Physicians with the highest in-hospital pneumonia patient volume (>27 patients x yr(-1)) cared for patients with greater severity/comorbidity, but with decreased odds of in-hospital mortality, compared with the lowest volume physicians (less than seven patients per year). The effects of internal medicine specialist or subspecialist care were mixed, with a reduction in deaths for the first 72 h and an increase in in-hospital deaths. Prehospitalisation visit by a physician was associated with decreased mortality. Healthcare organisation factors were the least strong predictor of mortality, demonstrating an effect only for 1-yr mortality in those discharged alive from hospital. Admissions to larger volume or metropolitan hospitals were associated with a decrease in mortality. Severity of illness and comorbidity had the strongest association with mortality. The first association of high-volume physician and pre-hospital care with decreased in-hospital mortality for community-acquired pneumonia is reported.