A phase I trial of CV706, a replication-competent, PSA selective oncolytic adenovirus, for the treatment of locally recurrent prostate cancer following radiation therapy

CV706 is a prostate-specific antigen (PSA)-selective, replication-competent adenovirus that has been shown to selectively kill human prostate cancer xenografts in preclinical models. To study the safety and activity of intraprostatic delivery of CV706, a Phase I dose-ranging study for the treatment of patients with locally recurrent prostate cancer after radiation therapy was conducted. Twenty patients in five groups were treated with between 1 x 10(11) and 1 x 10(13) viral particles delivered by a real-time, transrectal ultrasound-guided transperineal technique using a three-dimensional plan. The primary end point was the determination of treatment-related toxicity. Secondary objectives included evaluation of the antitumor activity of CV706 and monitoring for other correlates of antineoplastic action. In this study, CV706 was found to be safe and was not associated with irreversible grade 3 or any grade 4 toxicity. No grade >1 alterations in liver function tests associated with CV706 administration were observed. Posttreatment prostatic biopsies and detection of a delayed "peak" of circulating copies of virus provided evidence of intraprostatic replication of CV706. The study defined the timing of CV706 shedding into blood and urine as well as the appearance of circulating Ad5 neutralizing antibodies. Finally, this study documents the serum PSA response of treated patients and reveals a dose response showing that all five patients who achieved a > or =50% reduction in PSA were treated with the highest two doses of CV706. This study represents the first clinical translation of a prostate-specific, replication-restricted adenovirus for the treatment of prostate cancer. Taken together, this study documents that intraprostatic delivery of CV706 can be safely administered to patients, even at high doses, and the data also suggest that CV706 possesses enough clinical activity, as reflected by changes in serum PSA, to warrant additional clinical and laboratory investigation.

Navigating the time-space context of HIV and AIDS: daily routines and access to care

Geographers have shown that daily activities and social networks are constrained by time-space, but there are also enabling facets or opportunities created by daily routines for accessing material and emotional resources, improving quality of life, and even challenging existing power relations. Time-geography in this paper is taken as a starting point to assess how individuals living with HIV and AIDS navigate the complex and often difficult time space contexts defining their access to services. The concept of time space windows of access is offered as a way to understand the opportunities created by daily routines and social network interaction even in highly marginalized social, economic, and political circumstances. Survey data and in-depth interviews conducted with a diverse group of persons living with HIV and AIDS are used to illustrate this conceptual argument. Results indicate that the time space characteristics of daily routines, such as frequency of activities, variety or heterogeneity in activities, and whether activities are self- or social network-oriented, serve to define the availability of temporal and spatial windows of access to services. In addition, daily routines seem to matter for specific types of services, and have a limited role to play in terms of primary medical services or those associated with basic needs. The implications of these findings for theorizing and for enhancing access to services are provided.

Comparison of anti-PR3 capture and anti-PR3 direct ELISA for detection of antineutrophil cytoplasmic antibodies (ANCA) in long-term clinical follow-up of PR3-ANCA-associated vasculitis patients

A total of 118 sera from 11 patients with anti-neutrophil cytoplasmic antibodies against proteinase-3- (PR3-ANCA) associated vasculitis were retrospectively screened by anti-PR3 capture and anti-PR3 direct ELISA tests. We studied the relationship between capture and direct ELISA scores and the clinical activity of PR3-ANCA-associated vasculitis patients during follow-up. We also studied the ability of the anti-PR3 capture ELISA to detect positive values of PR3-ANCA in clinical vasculitis relapses. Only capture ELISA presented a significant relationship (p < 0.05) with clinical activity of PR3-ANCA-associated vasculitis patients over time. Capture ELISA appears to be a reliable method for detecting clinical relapses in this group of patients. Our results indicate that the new capture ELISA test is more effective than direct ELISA in the follow-up of patients with PR3-ANCA-associated vasculitis and in the detection of relapses.

Transduction and apoptosis induction in the rat prostate, using adenovirus vectors

Proapoptotic adenovirus vectors offer great promise for the treatment of cancer and nonmalignant conditions. Benign prostate hyperplasia (BPH) is a common nonmalignant enlargement of the prostate that involves epithelial, stromal, and smooth muscle components of the gland. We tested the hypothesis that an adenovirus vector expressing Fas ligand can be used to induce apoptosis in the prostate. We analyzed the efficiency of transduction and apoptosis induction in primary cultures of human prostate cells after adenovirus-mediated gene transfer. Efficient transduction was observed in primary prostate epithelial cells. Stromal and smooth muscle cells were more difficult to transduce, as no coxsackie-adenovirus receptor (CAR) expression was detectable on these cells. However, transduction was achieved in these cells when the multiplicity of infection was increased to 100 focal-forming units per cell, or when the vectors were delivered as calcium phosphate precipitates. Infection of all three primary prostate cell types with an adenovirus vector that expresses Fas ligand (AdFasL/G) resulted in rapid apoptosis. Direct injection of the rat prostate with an adenovirus vector carrying luciferase resulted in substantial luciferase expression. TUNEL analysis demonstrated that AdFasL/G administration induced low-level apoptosis in prostatic epithelial cells throughout the gland. As a first step toward enhancing the efficiency of prostate transduction in vivo, we tested an adenovirus vector that was engineered to have an expanded tropism. This vector, AdZ.F2K(pK7), was 10- to 500-fold more efficient than unmodified vectors in transducing prostate epithelial, smooth muscle, and stromal cells in culture. Moreover, AdZ.F2K(pK7) was more efficient than an unmodified vector at transducing the rat prostate in vivo, although the effect was dose dependent.

Muscular function and bone mass after knee arthroplasty

We report a study of 28 women with severe primary gonarthrosis followed for 1 year. Variations in bone mineral density and in functional behaviour of knee extensors and flexors were studied before and after implantation of uncemented total knee prosthesis. A functional deficit was noted in the extensor apparatus, which increased in the first 6 months following surgery. This strength was not improved 1 year following the arthroplasty, but it was more efficient as shown by the reduction of muscle fatigue. Flexor strength was conserved and a pathological muscle balance was maintained, reaching maximum efficiency over a smaller joint range.

Allele varepsilon4 of apolipoprotein E gene is less frequent in Down syndrome patient of the Sicilian population and has no influence on the grade of mental retardation

We evaluated the allele (and genotype frequencies in 60 Down syndrome (DS), 25 mothers and 57 controls from Sicily and its relation with mental retardation. DS patients and sex ratio (M:F) was 22.1+/-10.5 and 1.14, respectively. Allele varepsilon4 and varepsilon3 frequencies were respectively lower (P=0.015) and higher (P=0.005) in DS patients compared to controls. Genotype varepsilon3/varepsilon4 and varepsilon3/varepsilon3 were less (P=0.03) and more frequent (P=0.001) in DS patients, with respective odd ratios of 0.31 (CI at 95%: 0.18-0.49) and of 4.4 (CI at 95%: 3.4-5.7). No difference of allele (distribution was found in function of the grades of mental retardation according to DMS-IV. Our results show that the implication of Apo-E4 in the pathogenesis of Alzheimer disease cannot be extrapolated in that of dementia of DS.

Study of biologic attributes of Cuban dengue 2 virus after serial passage in primary dog kidney cells

OBJECTIVE

The serial passage of dengue viruses in primary dog kidney (PDK) cells has resulted in selection of attenuated viruses. However, the molecular changes responsible for loss of virulence are not well characterized. This article describes the isolation and biologic attributes of one dengue 2 virulent strain as a first step to allow the study of determinants of virulence at the molecular level.

METHODS

A15 dengue 2 Cuban strain was isolated from the viremic plasma of a patient with uncomplicated dengue fever during the 1981 epidemic. This was then subjected to serial passage in PDK cells. Viruses resulting from several PDK passages were compared to the parent strain for plaque size and temperature sensitivity, neurovirulence in newborn mice, and cytopathogenic effects on LLC-MK(2) and C6/36-HT cell lines.

RESULTS

A15 dengue 2 Cuban strain was successfully propagated in PDK cells. Primary dog kidney 52 to 53 viruses exhibited several biologic attributes, such as small plaques, temperature sensitivity, reduced mouse neurovirulence, and cytopathic effect in permissive cell lines.

CONCLUSIONS

These results represent the first step to allow attenuation of this strain of dengue 2 virus.

Prostate cancer gene therapy

Cancer-specific gene therapy is still in its infancy. Although the first gene therapy trials were initiated in the late 1980s, it was only more recently that the first successful treatment of a genetic disease was reported.3 The current problems with low efficiency of gene transfer coupled with the immunologic difficulties with certain vectors indicate that more effort needs to be directed at the basic science of gene transfer. Ultimately, successful cancer-specific gene therapy will require combinations of the lessons learned from the ex vivo and in vivo paradigms. The next generation of gene therapy trials likely will focus on combination therapy with conventional chemotherapeutic agents, differentiating agents, or radiation therapy. The obstacles to the development of gene-based human therapeutics (i.e., molecular medicine) are formidable, but the benefits are so great that eventually the technical issues of gene transfer methodology will be worked out, and ultimately this will become the standard of care, not only for inborn errors of metabolism, but also for cancer.

A cavernous haemangioma of breast in male: radiological-pathological correlation

Vascular tumours of the breast are especially rare in men, and a majority of them are angiosarcomas. In fact, we found only four cases of haemangioma in males in the literature. We present a case of cavernous haemangioma in a male aged 48 years, and which commenced as a palpable mass. We performed differential diagnosis and radiological-pathological correlation. We established the correct classification of this case histologically, and decided on the definitive therapeutic approach.

Long-term efficiency of catalytic converters operating in Mexico City

A 1999 ordinance by the Government of Mexico City bans 1993 model-year vehicles from on-road operation if their catalytic converters are not replaced with new ones. To validate the benefits of this action, we examined three issues related to exhaust emissions of vehicles equipped with catalytic converters. After selecting representative fleets of in-use vehicles, a comparison between emissions and catalyst efficiency in cars with two categories of exhaust emission limits was carried out. For that purpose, two fleets were selected, each made up of 10 vehicles run under similar conditions. A third, larger fleet with emissions control systems was used to evaluate and simulate real-world conditions of vehicles in a controlled laboratory. Finally, the aging effect on the catalytic converter was studied on vehicles run for 100,000 km, replacing their old emission control devices for new ones. The 1991-1992 model-year vehicles showed a high percentage of compliance with the corresponding emissions standard (90%) in comparison with 1993 model-year and later vehicles (Tier 0). However, NOx emissions were higher for the newer vehicles. Fifty percent of the 1991-1992 model-year vehicles evaluated under the official inspection/maintenance (I/M) procedure did not meet the regulated emissions standard when the results were compared with those of the U.S. Federal Test Procedure FTP-75. Our results suggest that the replacement of old catalytic converters with new ones will have little effect on decreasing polluting emissions because these vehicles were in very bad mechanical condition. Results of catalytic activity as a function of mileage indicated inefficient catalyst performance for the fleets tested. All pollutant conversions were below 90% efficiency, and they deteriorated by an average of 30% after the vehicles were run for 100,000 km.

Effects of allogeneic bone marrow transplantation on recipient bone mineral density: A prospective study

Allogeneic bone marrow transplant (BMT) recipients have many known risk factors for developing decreased bone mineral density (BMD) after transplantation. We performed a prospective sequential evaluation of BMD in the lumbar spine and nondominant hip using dual-energy x-ray absorptiometry (DEXA) in a cohort of 47 adult patients (median age, 43 years) who were undergoing radiation-based BMT for hematologic malignancies. Baseline DEXA studies were performed before BMT and repeated at 3 to 4 months, 6 to 8 months, and 12 to 14 months after BMT. The majority of patients (60%) had been minimally treated with combination cytotoxic chemotherapy, having received no more than 1 treatment regimen before BMT. Graft-versus-host disease prophylaxis consisted of cyclosporine in combination with either methotrexate or prednisone, or both. Mean lumbar spine and hip BMD were normal before BMT (spine: 1.01 g/cm2, z score = 96%; hip: 0.86 g/cm2, z score = 100%) and gradually decreased (spine: 0.98 g/cm2, z score = 94%; hip: 0.76 g/cm2, z score = 91%) at 12 to 14 months. These declines were statistically significant (P < .006 and < .002 for lumbar spine; P < .001 and < .001 for hip). In addition, the sharpest decline occurred during the first 6 months after BMT and was more marked in the hip than the lumbar spine. These data suggest that BMT adversely affects BMD in this patient population.

The sequence of the human genome

A 2.91-billion base pair (bp) consensus sequence of the euchromatic portion of the human genome was generated by the whole-genome shotgun sequencing method. The 14.8-billion bp DNA sequence was generated over 9 months from 27,271,853 high-quality sequence reads (5.11-fold coverage of the genome) from both ends of plasmid clones made from the DNA of five individuals. Two assembly strategies-a whole-genome assembly and a regional chromosome assembly-were used, each combining sequence data from Celera and the publicly funded genome effort. The public data were shredded into 550-bp segments to create a 2.9-fold coverage of those genome regions that had been sequenced, without including biases inherent in the cloning and assembly procedure used by the publicly funded group. This brought the effective coverage in the assemblies to eightfold, reducing the number and size of gaps in the final assembly over what would be obtained with 5.11-fold coverage. The two assembly strategies yielded very similar results that largely agree with independent mapping data. The assemblies effectively cover the euchromatic regions of the human chromosomes. More than 90% of the genome is in scaffold assemblies of 100,000 bp or more, and 25% of the genome is in scaffolds of 10 million bp or larger. Analysis of the genome sequence revealed 26,588 protein-encoding transcripts for which there was strong corroborating evidence and an additional approximately 12,000 computationally derived genes with mouse matches or other weak supporting evidence. Although gene-dense clusters are obvious, almost half the genes are dispersed in low G+C sequence separated by large tracts of apparently noncoding sequence. Only 1.1% of the genome is spanned by exons, whereas 24% is in introns, with 75% of the genome being intergenic DNA. Duplications of segmental blocks, ranging in size up to chromosomal lengths, are abundant throughout the genome and reveal a complex evolutionary history. Comparative genomic analysis indicates vertebrate expansions of genes associated with neuronal function, with tissue-specific developmental regulation, and with the hemostasis and immune systems. DNA sequence comparisons between the consensus sequence and publicly funded genome data provided locations of 2.1 million single-nucleotide polymorphisms (SNPs). A random pair of human haploid genomes differed at a rate of 1 bp per 1250 on average, but there was marked heterogeneity in the level of polymorphism across the genome. Less than 1% of all SNPs resulted in variation in proteins, but the task of determining which SNPs have functional consequences remains an open challenge.

Circulating soluble adhesion molecules in ANCA-associated vasculitis

BACKGROUND

To evaluate whether changes in concentrations of soluble (s) E-selectin, sP-selectin, sL-selectin, intercellular adhesion molecule 1 (sICAM-1), and vascular cell adhesion molecule 1 (sVCAM-1) reflect disease activity in patients with ANCA-associated vasculitis and whether serum levels of these adhesion molecules are related to the degree of renal failure in patients with chronic renal failure (CRF).

SUBJECTS AND METHODS

A sandwich ELISA was used to measure these soluble adhesion molecules in (i) sera from 20 patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (10 patients with Wegener's granulomatosis (WG) and 10 patients with microscopic polyangiitis (MPA)), obtained at the time of diagnosis and during the remission period; (ii) sera from 40 patients with CRF not undergoing haemodialysis.

RESULTS

At the time of diagnosis, serum levels of sE-selectin, sICAM-1 and sVCAM-1 (88+/-42 ng/ml, 437+/-184 ng/ml, 1720+/-1174 ng/ml respectively) were significantly higher in patients with ANCA-associated vasculitis than in healthy controls (P<0.0001, P=0.002 and P=0.001 respectively). Serum sP-selectin values did not differ from those obtained in normal donors. In contrast, sL-selectin levels (940+/-349 ng/ml) were significantly lower in patients than those recorded in healthy controls (P<0.0001). A significant decrease in concentrations of sE-selectin, sP-selectin, sICAM-1, and sVCAM-1 was observed between active and remission phases (P<0.0001, P=0.002, P=0.001 and P=0.001 respectively). No significant differences were observed in sL-selectin levels between active and remission phases. sL-selectin concentrations (802+/-306 ng/ml) during the remission phase remained lower than those observed in healthy controls (P<0.0001). No correlation was observed between serum creatinine and sE-selectin, sP-selectin, sICAM-1 and sVCAM-1 in patients of the CRF group. A slight negative correlation was established between creatinine and sL-selectin concentration.

CONCLUSIONS

Increased serum levels of sE-selectin, sICAM-1, and sVCAM-1 and decreased levels of sL-selectin in active ANCA-associated vasculitis, and the normalization of sE-selectin, sICAM-1, and sVCAM-1 during the remission phase suggest that the concentration of soluble levels of these adhesion molecules reflects disease activity. The decrease in sP-selectin levels between active and inactive phases also suggest that this receptor may reflect clinical activity. The lack of correlation between serum levels of sE-selectin, sP-selectin, sICAM-1, and sVCAM-1 and the degree of renal failure in patients with CRF suggests that the mechanism of clearance of these molecules is not renal.

Development of a monoclonal antibody specific to a recombinant envelope protein from dengue virus type 4 expressed in Pichia pastoris

A mouse monoclonal antibody (MAb, 4B6) was able to recognize dengue virus type 4 envelope (E) protein both as a recombinant protein in Pichia pastoris and when it was present in infected brains of suckling mice. 4B6 was characterized by enzyme-linked immunoadsorbent assay (ELISA), hemaglutination inhibition, neutralization, and immunoblot. The MAb was isotyped as IgG2a. It was serotype 4 specific and it inhibited hemaglutination and neutralized homologous virus. It did not enhance infection of P338D1 cells by dengue type 4 virus strain H-241 strain. This MAb was reactive with recombinant E protein and dengue 4 virus, as revealed by Western blot. In vivo, MAb 4B6 conferred passive protection in mice challenged with homologous virus. Currently, this MAb is being used to purify recombinant E protein for further studies.

Investigation of irradiated soil byproducts

The high dose irradiation of windblown soil deposited onto the surface of spent nuclear fuel is of concern to long-term fuel storage stability. Such soils could be exposed to radiation fields as great as 1.08 x 10(-3) C/kg-s (15,000 R/hr) during the 40-year anticipated period of interim dry storage prior to placement at the proposed national repository. The total absorbed dose in these cases could be as high as 5 x 10(7) Gy (5 x 10(9) rads). This investigation evaluated the potential generation of explosive or combustible irradiation byproducts during this irradiation. It focuses on the production of radiolytic byproducts generated within the pore water of surrogate clays that are consistent with those found on the Idaho National Engineering and Environmental Laboratory. Synthesized surrogates of localized soils containing combinations of clay, water, and aluminum samples, enclosed within a stainless steel vessel were irradiated and the quantities of the byproducts generated measured. Two types of clays, varying primarily in the presence of iron oxide, were investigated. Two treatment levels of irradiation and a control were investigated. An 18-Mev linear accelerator was used to irradiate samples. The first irradiation level provided an absorbed dose of 3.9 x 10(5)+/-1.4 x 10(5)Gy (3.9 x 10(7)+/-1.4 x 10(7) rads) in a 3-h period. At the second irradiation level, 4.8 x 10(5)+/-2.0 x 10(5)Gy (4.8 x 10(7)+/-2.0 x 10(7) rads) were delivered in a 6-h period. When averaged over all treatment parameters, irradiated clay samples with and without iron (III) oxide (moisture content = 40%) had a production rate of hydrogen gas that was a strong function of radiation-dose. A g-value of 5.61 x 10(-9)+/-1.56 x 10(-9) mol/J (0.054+/-0.015 molecules/100-eV) per mass of pore water was observed in the clay samples without iron (III) oxide for hydrogen gas production. A g-value of 1.07 x 10(-8)+/-2.91 x 10(-9) mol/J (0.103+0.028 molecules/100-eV) per mass of pore water was observed in the iron (III) oxide containing clay samples for hydrogen gas production. This value was noticeably larger when the samples were spiked with both KCl and KNO3 salts. The ratio of oxygen to nitrogen gas was observed to increase as a function of absorbed dose particularly in the presence of both KCl and KNO3 salts. The creation of radiolytic byproducts produced an observable but small increase in headspace pressure. Temperature increases during irradiation were not observed. Additionally, KCl and KNO3 salts added to the clays enhanced nitrite production as a function of radiation-dose and the type of clay considered. The addition of aluminum to these samples had no statistically discernable impact at the alpha = 0.05 level. Generation of the irradiation products, hydrogen peroxide and hydrogen gas also depended upon the type of clay irradiated and the presence of both KCl and KNO3 salts and the total dose received.

[Hypomelanosis of Ito - case report]

OBJECTIVES: The authors report a case of hypomelanosis of Ito (HI), a rare neurocutaneous syndrome with neurological and chromosomal alterations associated with cutaneous involvement and recurrent pneumonia. CASE REPORT: A male patient, age 1 year and 11 months, was admitted with bilateral bronchopneumonia to the São Vicente de Paulo Hospital. Examination revealed hypochromic maculas on the skin, compatible with HI, and a delay in neuropsychomotor development. The patient was submitted to incisive biopsy of the abdominal skin lesions, electroencephalogram, magnetic resonance, and cytogenetic evaluation. RESULTS: Histology and immunohistochemistry evinced absence of melanin and reductio of melanocyte in focal areas of the epidermis. The electroencephalogram revealed diffuse cortico-subcortical dysfunction. Encephalic magnetic resonance imaging was compatible with arachnoid cyst in the temporal region. Karyotype showed chromosome mosaicism (46, XY) and interstitial deletion of bands 22.2 to 24.4 of the long arm of chromosome 10 (25%). CONCLUSIONS: Analysis of skin lesions is important for the etiologic definition of neuropediatric disorders.

Use of a modified American Urological Association Symptom Score for the evaluation of the quality of life of patients with prostate cancer

OBJECTIVES

To present our experience with the clinical use of a modified American Urological Association Symptom Score (AUASS) and a quality-of-life (QOL) questionnaire in obtaining clinically available information and to investigate whether a relatively short questionnaire, administered in the clinic, can help in identifying symptoms and QOL issues associated with various types of definitive treatments (DTs) for prostate cancer (PCa) and its impact on patients' QOL.

METHODS

The AUASS was modified to contain questions on continence and was combined with a short QOL questionnaire. It was administered to control groups and all patients with PCa during their clinic visit. The responses were analyzed and correlated with the DT of PCa.

RESULTS

The questionnaire was administered 846 times to 375 patients with PCa and to 170 controls during clinic visits. We found that patients on watchful waiting had symptom scores and QOL responses similar to controls and that DT was associated with worse scores and a reduced QOL. DT with continence was associated with a better QOL than DT with incontinence. Incontinence of either urine or stool, among DT patients, had similar adverse impact on QOL, compared with continent DT patients.

CONCLUSIONS

The questionnaire, administered in a clinical setting, provides insight into the QOL and symptoms associated with interventions aimed at curing PCa. The use of such a questionnaire enhances the objective documentation of treatment outcomes of PCa and benefits the patients by increasing their opportunities to express their problems.

Coexpression of hypoxia-inducible factor 1-alpha and vascular endothelial growth factor in Wilms' tumor

BACKGROUND/PURPOSE

Hypoxia-inducible factor 1 alpha (HIF-1alpha) is an important transcriptional factor responsible for regulating expression of the angiogenic cytokine, vascular endothelial growth factor (VEGF). Little information is available regarding factors involved in the hypoxic cascade, such as HIF or VEGF in Wilms' tumor. We concomitantly evaluate the expression of HIF-1alpha and VEGF in ex vivo human Wilms' tumor specimens.

METHODS

Immunohistochemical analysis (IHC) utilizing a monoclonal human anti-HIF-1alpha or a polyclonal anti-VEGF antibody was performed on ex vivo specimens of Wilms' tumor (n = 18). Predominant tumor histologic subtype was divided equally between epithelial (n = 6), blastemal (n = 6), and mixed (n = 6). Specimens were scored on a predetermined scale for distribution (percent positive cells) and intensity of HIF-1alpha/VEGF expression within areas of tumor.

RESULTS

IHC analysis found that HIF-1alpha and VEGF were expressed in all Wilms' tumor specimens. Strong nuclear staining for HIF-1alpha was seen in all samples evaluated, (n = 18), mean score 2.7 (>50% cells exhibiting nuclear HIF-1alpha expression). Cytoplasmic staining for HIF-1alpha also was seen in 15 of 18 samples (83%). Distribution of VEGF was equivalent between blastemal and epthelial components, mean score 2.23 versus 2.35.

CONCLUSIONS

HIF-1alpha and one of its regulatory end-products, the angiogenic cytokine VEGF, are simultaneously expressed in human Wilms' tumor. In Wilms' tumor, intratumoral hypoxia may stimulate tumor conversion to the angiogenic phenotype and incite production of VEGF. Strategies targeting the hypoxic cascade ultimately may prove efficacious against Wilms' tumor.

Effect of spatial extension on noise-enhanced phase locking in a leaky integrate-and-fire model of a neuron

Signal transmission enhanced by noise has been recently investigated in detail on the single compartment, also referred to as single point, leaky integrate-and-fire model neuron under a subthreshold stimulation. In this paper we study how this phenomenon is influenced by taking into account the spatial characteristics of the neuron. A stochastic two-point leaky integrate-and-fire model, comprising a dendritic compartment and trigger zone, under periodic stimulation is studied. A method of how to measure synchronization between the signal and the output in both, experiments and models, is proposed. This method is based on a distance between the exact periodic spiking, as expected for sufficiently strong and noiseless stimulation, and neuronal activity evoked by a subthreshold signal corrupted by noise. It is shown that qualitatively the same phenomenon, phase-locking enhanced by the noise, as found in the spatially unstructured neuron is produced by the spatially complex neuron. However, quantitatively there are significant differences. Namely, the two-point model neuron is more robust against the noise and therefore its amplitude has to be higher to enhance the signal. Further, it is found that the range of the critical levels of noise is larger for the two-point model than for the single-point one. Finally, the enhancing effect at the optimal noise is more efficient in the single-point model and thus the firing patterns at their optimal noise levels are different in both models.

DNA damage after chemotherapy correlates with tumor response and survival in small cell lung cancer patients

To explore the induction of chemotherapy (CT) DNA damage and its correlation with tumor response and patient survival, we undertook the present study in 20 small cell lung cancer (SCLC) patients. All patients underwent the same treatment based on CT courses of carboplatin and etoposide. Blood samples were taken before and immediately after CT and every 12 weeks during follow-up. Nuclear DNA damage was determined through the variations in three mitochondrial pseudogene mutations in DNA of peripheral blood mononuclear cells. They were detected by mutation-specific PCR and assessed by a semiquantitative method. The relative level of mutation rose after chemotherapy in all cases. Among the 11 patients (55%) with higher relative levels of mutations, 9 (82%) of them achieved a complete response. In contrast, of the 9 patients (45%) with lower relative levels of mutations, only 2 (18%) achieved a complete response, displaying a statistically significant difference (P=0.02). The overall survival for patients with marked genomic damage was 18 months (range 10-24), and for patients with low degree of DNA damage, it was 12 months (range 5-15) (P=0.002). Genomic damage detected after chemotherapy treatment correlates positively with tumor response and patient survival.

Biological pathways to bladder carcinogenesis

The transformation of normal urothelium into histologically different neoplastic states has been well characterized, and current clinical management of both superficial and invasive bladder cancer has benefited from recent scientific discoveries. The ability to define novel treatment strategies including surgical, chemotherapeutic, and gene therapies relies on our understanding of the basic mechanisms underlying human bladder carcinogenesis. Many in vitro culture systems and in vivo animal models have been developed over recent years, which have been used to define key molecular events that are associated with the development of bladder cancer. The biological pathways through which normal urothelium may progress to superficial or invasive disease will be discussed in the framework of recent advances in the field.