Long-term recurrences and mortality in patients with noncardiac syncope

INTRODUCTION AND OBJECTIVES

There are no in-depth studies of the long-term outcome of patients with syncope after exclusion of cardiac etiology. We therefore analyzed the long-term outcome of this population.

METHODS

For 147 months, we included all patients with syncope referred to our syncope unit after exclusion of a cardiac cause.

RESULTS

We included 589 consecutive patients. There were 313 (53.1%) women, and the median age was 52 [34-66] years. Of these, 405 (68.8%) were diagnosed with vasovagal syncope (VVS), 65 (11%) with orthostatic hypotension syncope (OHS), and 119 (20.2%) with syncope of unknown etiology (SUE). During a median follow-up of 52 [28-89] months, 220 (37.4%) had recurrences (21.7% ≥ 2 recurrences), and 39 died (6.6%). Syncope recurred in 41% of patients with VVS, 35.4% with OHS, and 25.2% with SUE (P=.006). In the Cox multivariate analysis, recurrence was correlated with age (P=.002), female sex (P <.0001), and the number of previous episodes (< 5 vs ≥ 5; P <.0001). Death occurred in 15 (3.5%) patients with VVS, 11 (16.9%) with OHS, and 13 (10.9%) with SUE (P=.001). In the multivariate analysis, death was associated with age (P=.0001), diabetes (P=.007), and diagnosis of OHS (P=.026) and SUE (P=.020).

CONCLUSIONS

In patients with noncardiac syncope, the recurrence rate after 52 months of follow-up was 37.4% and mortality was 6.6% per year. Recurrence was higher in patients with a neuromedial profile and mortality was higher in patients with a nonneuromedial profile.

Water dynamics over a Western Patagonian watershed: Land surface changes and human factors

Warming trends in Patagonia and severe droughts in recent decades are still poorly understood in terms of their hydrological effects. The effects of climate change on water dynamics in addition to human water management could generate a future water scarcity scenario in one of the regions with the most abundant water resources of Chile. The aim of this work is to focus on assessing the impacts of warming trends on water dynamics in the Patagonian Simpson River watershed during the last two decades. We estimated anomalies in the main components of water balance such as precipitation (P), snow cover (SC), evapotranspiration (ET) and streamflows (Q) as well as surface variables and meteorological forcing (i.e. air temperature - Ta, solar radiation - RS, land surface temperature - LST). The processed data were obtained from remote sensing, reanalysis and in-situ data. We implemented a trend analysis for each variable in the period 2000-2019 at monthly, seasonal and annual scale. Results showed a warming trend in Ta and LST of about 1.2 °C and 2.1 °C, respectively, concentrated mainly in the autumn and winter seasons. Although P showed non-significant trends, Q diminished significantly at rates of more than 9.1 m³/s/decade, representing 36% of its historical mean. However, the decreases in Q are seen only in the maximum (spring) and minimum (summer) seasonal flows. These decreases are explained by significant increases in ET, led by a positive feedback of its drivers (LST, Ta and RS), which is directly linked to the impact of warming and an associated vegetation greenness in the watershed, as well as a decrease in SC during winter that feeds the Simpson River during spring and summer. The decrease in Q is reinforced by the intensification of water withdrawals in recent decades, as shown by an accelerated increase in water rights for agricultural and drinking uses. In a context of water scarcity and increasing and extreme droughts, this work contributes to further understanding water dynamics in western Patagonia, providing support for policy and decision-making when defining sustainable productive practices at watershed scale.

Clinical outcomes in percutaneous coronary interventions with polymer-free vs. durable-polymer stents: a metanalysis of randomized clinical trials

Background

Polymer-free (PF) stents were designed as an alternative to durable-polymer (DP) drug-eluting stents to minimize the time on dual antiplatelet treatment for patients at high-risk of bleeding. Nonetheless, the efficacy and safety of PF vs. DP stents in patients undergoing percutaneous coronary intervention (PCI) remain controversial.

Methods

We performed a metanalysis with currently available studies that assessed the effect of PF-stents vs. DP-stents after performing a systematic search. The endpoints analyzed were all-cause death, myocardial infarction, target lesion revascularization (TLR) and probable or definite stent thrombosis. The raw numbers of incident end-points reported in each study were used. We performed analyses in short and long term (&lt;1 or &gt;1 year follow-up) studies.

Results

We included 12464 patients from 8 studies (5 short-term and 3 long-term): 6723 treated with PF-stents and 5741 with DP stents. Females represented 23.3% (n=3284) and 33.7% (n=4202) were included in the setting of acute coronary syndromes. As shown in the figure, PF-stents were associated to lower incidence of all-cause mortality (HR: 0.91 95% CI 0.84–0.98; p=0.016) and TLR (HR: 0.88 95% CI 0.80–0.96; p=0.003). No differences were observed in the risk of cardiovascular death (HR: 0.96 95% CI 0.86–1.06 p=0.415), myocardial infarction (HR: 0.90 95% CI 0.80–1.01; p=0.061) or probable-definite stent thrombosis (HR: 0.92 95% CI 0.74–1.14; p=0.447). Finally, no differences in the primary end-point (HR: 0.92 95% CI 0.83–1.03; p=0.143) were detected with PF-stents vs. DP-stents. No significant heterogenicity was observed in any of the endpoints, except for the incidence of stent thrombosis.

Conclusions

Under current PCI techniques the use of PF-stent might be associated to better outcomes, especially in terms of all-cause mortality and TLR.

Funding Acknowledgement

Type of funding sources: None.

Tuning the sensitivity of lanthanide-activated NIR nanothermometers in the biological windows

Lanthanide-activated SrF₂ nanoparticles with a multishell architecture were investigated as optical thermometers in the biological windows. A ratiometric approach based on the relative changes in the intensities of different lanthanide (Nd³⁺ and Yb³⁺) NIR emissions was applied to investigate the thermometric properties of the nanoparticles. It was found that an appropriate doping with Er³⁺ ions can increase the thermometric properties of the Nd³⁺-Yb³⁺ coupled systems. In addition, a core containing Yb³⁺ and Tm³⁺ can generate light in the visible and UV regions upon near-infrared (NIR) laser excitation at 980 nm. The multishell structure combined with the rational choice of dopants proves to be particularly important to control and enhance the performance of nanoparticles as NIR nanothermometers.

Podoplanin mediates ECM degradation by squamous carcinoma cells through control of invadopodia stability

Invadopodia are actin-rich cell membrane projections used by invasive cells to penetrate the basement membrane. Control of invadopodia stability is critical for efficient degradation of the extracellular matrix (ECM); however, the underlying molecular mechanisms remain poorly understood. Here, we uncover a new role for podoplanin, a transmembrane glycoprotein closely associated with malignant progression of squamous cell carcinomas (SCCs), in the regulation of invadopodia-mediated matrix degradation. Podoplanin downregulation in SCC cells impairs invadopodia stability, thereby reducing the efficiency of ECM degradation. We report podoplanin as a novel component of invadopodia-associated adhesion rings, where it clusters prior to matrix degradation. Early podoplanin recruitment to invadopodia is dependent on lipid rafts, whereas ezrin/moesin proteins mediate podoplanin ring assembly. Finally, we demonstrate that podoplanin regulates invadopodia maturation by acting upstream of the ROCK-LIMK-Cofilin pathway through the control of RhoC GTPase activity. Thus, podoplanin has a key role in the regulation of invadopodia function in SCC cells, controlling the initial steps of cancer cell invasion.

Loss of Tribbles pseudokinase-3 promotes Akt-driven tumorigenesis via FOXO inactivation

Tribbles pseudokinase-3 (TRIB3) has been proposed to act as an inhibitor of AKT although the precise molecular basis of this activity and whether the loss of TRIB3 contributes to cancer initiation and progression remain to be clarified. In this study, by using a wide array of in vitro and in vivo approaches, including a Trib3 knockout mouse, we demonstrate that TRIB3 has a tumor-suppressing role. We also find that the mechanism by which TRIB3 loss enhances tumorigenesis relies on the dysregulation of the phosphorylation of AKT by the mTORC2 complex, which leads to an enhanced phosphorylation of AKT on Ser473 and the subsequent hyperphosphorylation and inactivation of the transcription factor FOXO3. These observations support the notion that loss of TRIB3 is associated with a more aggressive phenotype in various types of tumors by enhancing the activity of the mTORC2/AKT/FOXO axis.

New experimental models of skin homeostasis and diseases

Homeostasis, whose regulation at the molecular level is still poorly understood, is intimately related to the functions of epidermal stem cells. Five research groups have been brought together to work on new in vitro and in vivo skin models through the SkinModel-CM program, under the auspices of the Spanish Autonomous Community of Madrid. This project aims to analyze the functions of DNA methyltransferase 1, endoglin, and podoplanin in epidermal stem cell activity, homeostasis, and skin cancer. These new models include 3-dimensional organotypic cultures, immunodeficient skin-humanized mice, and genetically modified mice. Another aim of the program is to use skin-humanized mice to model dermatoses such as Gorlin syndrome and xeroderma pigmentosum in order to optimize new protocols for photodynamic therapy.

Polymorphisms in HIF-1alpha affect presence of lymph node metastasis and can influence tumor size in squamous-cell carcinoma of the glottic larynx

BACKGROUND

HIF-1alpha plays a key role in the development and progression of cancer. Its polymorphic variants C1772T and G1790A have been associated with greater susceptibility to cancer and increased tumor progression.

METHODS

We determined the distribution of these polymorphisms among 121 patients with glottic cancer and 154 healthy volunteers by PCR-RFLP. We also analyzed the relationship between the presence of these polymorphisms and various clinicopathologic variables.

RESULTS

Advanced tumors (T3-T4) were associated with the TT variant (p = 0.036), which was present in 75 % of T4 tumors (p = 0.008). Among patients with nodal metastasis (N+), 41.7 and 22 % were carrying the TT and GA variants, respectively, compared with 9.4 and 2 % of the patients with no metastasis (N0), (p = 0.006 and p = 0.032).

CONCLUSIONS

The presence of the TT and GA variants were associated with lymph node metastasis, while the presence of the TT variant can be associated with larger tumor size.

Optical transition probabilities in Er3+- and Tm3+-doped LiLa9(SiO4)6O2 crystals

In this work, Er(3+) and Tm(3+)-doped LiLa(9)(SiO(4))(6)O(2) crystals have been grown from an Li(2)MoO(4) flux in the 1360-940 °C temperature range. Optical absorption spectra have been measured to obtain the experimental oscillator strengths of the transitions from the ground state to the excited levels. Judd-Ofelt calculations have been performed to estimate the Ω(2), Ω(4) and Ω(6) intensity parameters. The dynamics of selected Er(3+) and Tm(3+) manifolds have been investigated under selective pulsed excitation in order to determine the energy gap law by comparing the observed decay rates with the Judd-Ofelt predictions.

Phase II trial of docetaxel-irinotecan combination in advanced esophageal cancer

BACKGROUND

Preclinical evidence suggests synergy between docetaxel and irinotecan, two drugs active in esophagogastric cancer. We previously demonstrated the safety of docetaxel 35 mg/m2 and irinotecan 50 mg/m2 given on days 1 and 8 of a 21-day schedule.

MATERIALS AND METHODS

Patients who had unresectable/metastatic squamous cell carcinoma or adenocarcinoma of the esophagus, measurable disease, Eastern Cooperative Oncology Group performance status of zero to two, and normal bilirubin were eligible. Tumor assessment was carried out every three cycles.

RESULTS

We enrolled 29 chemotherapy-naive (CN) and 15 chemotherapy-exposed (CE) eligible patients. Principal toxic effects were diarrhea, neutropenia, and hyperglycemia. There were no toxic deaths. There was one early death, from myocardial infarction. Among 26 CN and assessable patients, there were seven (26.9%) with a partial response (PR) and one (3.8%) with a complete response (CR). There were two PRs and one CR among the patients with CE disease. Median time to progression for CN patients was 4.0 months and for CE patients 3.5 months. Median survival for CN eligible patients was 9.0 months and for CE patients 11.4 months.

CONCLUSIONS

Docetaxel-irinotecan combination given on a weekly x 2 of 3 schedule is promising in the treatment of advanced esophageal cancer.

Evaluating a Peer Intervention Strategy for the Promotion of Sexual Health-Related Knowledge and Skills in 10- to 14-Year-Old Girls. Findings from the “Entre Amigas” Project in Nicaragua

Purpose.

Report effects on knowledge of sexual health and gender from an intervention using peer methodology in Nicaragua.

Design.

A prepost nonequivalent control group design.

Setting.

Ciudad Sandino, Managua, Nicaragua.

Subjects.

A total of 599 girls were surveyed, 60% nonintervened and 40% intervened.

Intervention.

Peer methodology consisted of (1) meetings in which girls talked and worked with other girls, (2) mothers taking an active role in the peer groups, and/or (3) girls watching the soap opera “Sexto Sentido.”

Measures.

Indices measuring changes in sexual knowledge and gender vision.

Results.

Girls participating in the peer groups were twice as likely to have satisfactory sexual health-related self-esteem as those who did not participate. Eleven percent of the girls achieved satisfactory self-esteem as a result of the (peer groups × mothers) interaction and 15% due to the (peer groups × mothers × “Sexto Sentido”) interaction. Girls participating in the peer groups were three times as likely to have satisfactory gender visions; if exposed to all three components, they were almost four times as likely to develop satisfactory gender visions.

Conclusions.

Peer methodology, participation of a female family member, and an educational soap opera seem beneficial in promoting sexual health-related knowledge and gender vision in young girls.

SPECT/CT imaging of oncolytic adenovirus propagation in tumours in vivo using the Na/I symporter as a reporter gene

Oncolytic adenoviruses have shown some promise in cancer gene therapy. However, their efficacy in clinical trials is often limited, and additional therapeutic interventions have been proposed to increase their efficacies. In this context, molecular imaging of viral spread in tumours could provide unique information to rationalize the timing of these combinations. Here, we use the human sodium iodide symporter (hNIS) as a reporter gene in wild-type and replication-selective adenoviruses. By design, hNIS cDNA is positioned in the E3 region in a wild-type adenovirus type 5 (AdIP1) and in an adenovirus in which a promoter from the human telomerase gene (RNA component) drives E1 expression (AdAM6). Viruses show functional hNIS expression and replication in vitro and kinetics of spread of the different viruses in tumour xenografts are visualized in vivo using a small animal nano-SPECT/CT camera. The time required to reach maximal spread is 48 h for AdIP1 and 72 h for AdAM6 suggesting that genetic engineering of adenoviruses can affect their kinetics of spread in tumours. Considering that this methodology is potentially clinically applicable, we conclude that hNIS-mediated imaging of viral spread in tumours may be an important tool for combined anticancer therapies involving replicating adenoviruses

Molecular biology of malignant melanoma and other cutaneous tumors

Skin cancer is the most common cancer worldwide. Its incidence is doubling every 15-20 years likely because of an aging population, changes in behaviour towards sun exposure, and increased UV light fluency at the earth surface due to ozone depletion. In this review, we summarize the most important genetic changes contributing to the development of malignant melanoma, basal cell carcinoma and squamous cell carcinoma, the main tumor entities arising in the skin. While our understanding of the oncogenes and tumor suppressor genes involved in the development and progression of skin tumors is still fragmentary, recent advances have shown alterations affecting conserved signalling pathways that control cellular proliferation and viability. These pathways include INK4alpha/Rb, ARF/p53, RAS/MAPKs, and sonic hedgehog/Gli.

[Epidural hematoma after catheter removal in a patient without coagulation disorders]

A 69-year-old man with rectal adenocarcinoma and no relevant medical history was scheduled for anterior resection of the tumor under combined anesthesia. The epidural catheter was removed 48 h after surgery. A clinical picture consistent with a diagnosis of epidural hematoma developed gradually and was confirmed by magnetic resonance imaging. The last dose of low molecular weight heparin had been administered 8 h before catheter removal and blood analyses were normal. Recovery was complete following laminectomy and evacuation of the hematoma 31 h after the onset of symptoms. Our analysis of the literature on conditions leading to epidural hematoma after catheter insertion revealed that complications may appear for unknown reasons even when catheter management and thrombolytic prophylaxis are appropriate. Nevertheless, the maneuver for removing an epidural catheter is clearly not risk-free and can cause complications. Monitoring after removal is therefore important if complications are to be detected early.

Vitamin D(3) promotes the differentiation of colon carcinoma cells by the induction of E-cadherin and the inhibition of beta-catenin signaling

The beta-catenin signaling pathway is deregulated in nearly all colon cancers. Nonhypercalcemic vitamin D3 (1alpha,25-dehydroxyvitamin D(3)) analogues are candidate drugs to treat this neoplasia. We show that these compounds promote the differentiation of human colon carcinoma SW480 cells expressing vitamin D receptors (VDRs) (SW480-ADH) but not that of a malignant subline (SW480-R) or metastasic derivative (SW620) cells lacking VDR. 1alpha,25(OH)2D(3) induced the expression of E-cadherin and other adhesion proteins (occludin, Zonula occludens [ZO]-1, ZO-2, vinculin) and promoted the translocation of beta-catenin, plakoglobin, and ZO-1 from the nucleus to the plasma membrane. Ligand-activated VDR competed with T cell transcription factor (TCF)-4 for beta-catenin binding. Accordingly, 1alpha,25(OH)2D(3) repressed beta-catenin-TCF-4 transcriptional activity. Moreover, VDR activity was enhanced by ectopic beta-catenin and reduced by TCF-4. Also, 1alpha,25(OH)2D(3) inhibited expression of beta-catenin-TCF-4-responsive genes, c-myc, peroxisome proliferator-activated receptor delta, Tcf-1, and CD44, whereas it induced expression of ZO-1. Our results show that 1alpha,25(OH)2D(3) induces E-cadherin and modulates beta-catenin-TCF-4 target genes in a manner opposite to that of beta-catenin, promoting the differentiation of colon carcinoma cells.

Genistein and curcumin block TGF-beta 1-induced u-PA expression and migratory and invasive phenotype in mouse epidermal keratinocytes

Transforming growth factor-beta 1 (TGF-beta 1) stimulates migration/invasion of mouse transformed keratinocytes and increases urokinase (u-PA) expression/secretion. In this report, we analyzed the biological behavior of two naturally occurring inhibitors of protein tyrosine kinases, genistein and curcumin, that could abrogate the enhancement of u-PA levels induced by TGF-beta 1 in transformed keratinocytes. Our results showed that genistein and curcumin blocked this response in a dose-dependent manner and also inhibited the TGF-beta 1-induced synthesis of fibronectin, an early responsive gene to the growth factor. Both compounds also reduced TGF-beta 1-stimulated cell migration and invasiveness. These results suggest that a tyrosine kinase-signaling pathway should be involved in TGF-beta 1-mediated increased malignancy of transformed keratinocytes and that genistein and curcumin could play an important role in inhibiting tumor progression.

Ectopic expression of PA2.26 antigen in epidermal keratinocytes leads to destabilization of adherens junctions and malignant progression

PA2.26 antigen is a small mucin-type transmembrane glycoprotein induced in mouse epidermal keratinocytes during carcinogenesis. It is located at plasma membrane projections, such as microvilli and ruffles, where it interacts with the actin cytoskeleton. Previous studies revealed that ectopic expression of PA2.26 in epidermal MCA3D keratinocytes induces cell surface extensions and increased motility. Here, we show that PA2.26-expressing MCA3D (3D2.26) cell transfectants undergo a phenotypic conversion linked to the acquisition of malignant characteristics. The 3D2.26 cells down-regulate basal keratin K14 and up-regulate vimentin and keratin K8 expression. Immunofluorescence analysis in 3D2.26 cell cultures showed loss of cortical actin filaments and destabilization of adherens junctions mediated by E- and P-cadherin, although both cadherin mRNAs were expressed in the transfectants. When the cadherin protein levels were analyzed in Western blots, no P-cadherin protein or smaller polypeptide E-cadherin forms were detected, suggesting that E- and P-cadherin synthesized in 3D2.26 cells was unstable and proteolytically degraded. Transplantation of 3D2.26 cells into athymic nude mice induced tumors, whereas MCA3D cells and control (3DN) transfectants were not tumorigenic after 72 days postinjection. The phenotype of the tumors was undifferentiated, with mixed regions exhibiting a glandular differentiation pattern in which the presence of numerous surface microvilli was observed at the ultrastructural level. Interestingly, PA2.26 antigen was highly expressed in these microvillous cell surfaces. Tumor cells were vimentin- and K8-positive and showed an aberrant pattern of E-cadherin protein expression in which large cytoplasmic aggregates were found close to the nucleus. Infiltration of tumor cells into lymphatic vessels and the presence of frequent regional lymph node metastases were also observed in the tumors. These results indicate that expression of PA2.26 antigen in premalignant keratinocytes induces a fully transformed and metastatic phenotype, and they suggest an involvement of PA2.26 in malignant progression.

Blockade of Smad4 in transformed keratinocytes containing a Ras oncogene leads to hyperactivation of the Ras-dependent Erk signalling pathway associated with progression to undifferentiated carcinomas

Smad4 functions as a transcription factor in TGF-beta signalling. We have investigated the role of Smad4 in the TGF-beta1 cell responses of transformed PDV keratinocytes, which contain a Ras oncogene, and of non-tumorigenic MCA3D keratinocytes, by transfecting both cell lines with a dominant-negative Smad4 construct. Smad4 mediates TGF-beta1-induced up-regulation of p21Cip1 and growth arrest in MCA3D cells. However, in PDV keratinocytes, Smad4 is only partially involved in TGF-beta1-induced growth inhibition, and does not mediate enhancement of p21Cip1 levels by the growth factor. TGF-beta1 activates Ras/Erk signalling activity in both cell lines. PD098059, a specific inhibitor of MEK, disminishes TGF-beta1-induced p21Cip1 levels in PDV but not in MCA3D cells, suggesting an involvement of Erk in up-regulation of p21Cip1 by TGF-beta1 in PDV cells. PDV dominant-negative Smad4 cell transfectants, but not MCA3D transfectants, showed constitutive hyperactivation of the Ras/Erk signalling pathway, increased secretion of urokinase, higher motility properties, and a change to a fibroblastoid cell morphology associated in vivo with the transition from a well differentiated to a poorly differentiated tumour phenotype. Infection of MCA3D control and dominant negative Smad4 cell transfectants with retroviruses carrying a Ras oncogene led to enhanced p21Cip1 and urokinase secreted levels, independently of TGF-beta1 stimulation, that were reduced by PD098059. These results suggest that Smad4 acts inhibiting Ras-dependent Erk signalling activity in Ras-transformed keratinocytes. Loss of Smad4 function in these cells results in hyperactivation of Erk signalling and progression to undifferentiated carcinomas. Oncogene (2000) 19, 4134 - 4145

Involvement of the Ras/MAPK signaling pathway in the modulation of urokinase production and cellular invasiveness by transforming growth factor-beta(1) in transformed keratinocytes

Transformed PDV keratinocytes respond to TGF-beta(1) by stimulating cell motility and invasiveness concomitantly to enhancement of the urokinase-type plasminogen activator (uPA) expression/secretion. Depletion of extracellular signal-regulated kinase (ERK1, 2) proteins by treatment of PDV cells with antisense oligonucleotides reduced basal uPA production and abolished stimulation of uPA secreted levels and cell motility by TGF-beta(1). PD098059, an inhibitor of mitogen-activated protein kinase (MAPK) kinase (MEK), decreased TGF-beta(1)-induced uPA mRNA expression, secreted activity in a dose-dependent manner, and abrogated TGF-beta(1)-stimulated cell motility and invasiveness. PDV-derived dominant-negative RasN17 cell transfectants secreted similar amounts of uPA and exhibited similar invasive abilities as the parental cells or control clones, but were unable to respond to TGF-beta(1) for stimulation of uPA-secreted levels and invasiveness. These results suggest that a Ras/MAPK transduction pathway is involved in the invasive response of transformed keratinocytes to TGF-beta(1).

Identification of PA2.26 antigen as a novel cell-surface mucin-type glycoprotein that induces plasma membrane extensions and increased motility in keratinocytes

PA2.26 antigen was identified as a cell-surface protein induced in epidermal carcinogenesis and skin remodeling processes. PA2.26 is expressed in carcinoma cell lines and cultured fibroblasts but absent in nontumorigenic keratinocytes. In tissues, PA2.26 is present in epithelial cells of the choroid plexus, ependyma, glomerulus and alveolus, in mesothelial cells, and in endothelia of lymphatic vessels. Biochemical characterization of PA2.26 protein and sequence analysis of the isolated cDNA demonstrate that PA2.26 antigen is a mucin-like transmembrane glycoprotein. Confocal and immunoelectron microscopy analysis in cultured cells reveal that PA2. 26 is concentrated in actin-rich microvilli and plasma membrane projections, such as filopodia, lamellipodia and ruffles, where it colocalizes with members of the ERM (ezrin, radixin, moesin) family protein. Ezrin and moesin, but not radixin, can be coimmunoprecipitated together with PA2.26 from cell lysates. Ectopic expression of PA2.26 in immortalized, nontumorigenic, keratinocytes induces an epithelial-fibroblastoid morphological conversion with increased plasma membrane extensions, concomitantly to a major reorganization of the actin cytoskeleton, redistribution of ezrin to cell-surface projections, and enhanced motility. These findings suggest an involvement of PA2.26 in cell migration.

In vivo radiosensitizing effect of the adenovirus E1A gene in murine and human malignant tumors

The adenovirus E1A gene is a potent inducer of chemosensitivity and radiosensitivity through p53-dependent and independent mechanisms. We have studied the sensitivity of murine (MSC11A5, a sarcomatoid epidermoid carcinoma) and human (HeLa, human cervix carcinoma) E1A-expressing tumors, in vivo, after treatment with cisplatin or gamma-irradiation. In athymic mice, half-body irradiation was performed in an AECL Cobalt unit, at an SSD of 80 cm. Daily fractions of 300 cGy over 3 days, up to a total dose of 9 Gy. Cisplatin was injected intraperitoneally at a dose of 9 mg per kg of body weight. After gamma-irradiation or intraperitoneal injection of cisplatin, about 30% of the E1A-expressing tumors regressed completely or were associated with a marked decrease in tumorigenicity over the following weeks. We conclude that malignant tumors, when expressing adenovirus E1A, are very sensitive to treatment with DNA-damaging agents, in vivo, regardless of the p53 status of the tumors.

Adenovirus lacking the 19-kDa and 55-kDa E1B genes exerts a marked cytotoxic effect in human malignant cells

The adenovirus (Ad) E1A gene exerts an antitumor effect and can induce sensitivity to treatment with DNA-damaging agents. In contrast, the Ad 19-kDa E1B protein inhibits E1A-mediated apoptosis and the 55-kDa E1B inactivates the p53 protein. In this paper, we study the in vitro and in vivo effects of a 19-kDa and 55-kDa E1B-defective Ad in several malignant human tumor cell lines.

MATERIALS AND METHODS

Nontumorigenic human fibroblasts (CCD-45SK and Hs67), peripheral blood lymphocytes, and several human tumor cell lines derived from cervix, colon, and breast carcinomas, epidermoid carcinoma, and osteosarcoma (HeLa, HT29, MCF7, Saos-2, and A431 cell lines) were studied. Wild-type (wt) Ad type 5 and H5 dL118 Ad, a mutant with the deleted E1B region, were employed. The cells were infected at 20 plaque-forming units, and cell viability was evaluated by the crystal violet method. In the in vivo experiments, 2 x 10(6) cells from the carcinoma cell lines HeLa, A431 and HT29 were injected into nude mice. The tumorigenicity of previously infected cells and after an intratumoral injection of Ad was analyzed. The mice received whole-body gamma-irradiation.

RESULTS

The H5 dL118 mutant produced a marked cytopathic effect in all of the malignant cells, surpassing that of the wt Ad; viability at 72 hours ranged from 11% to 20% for H5 dL118 Ad and from 70% to 93% for the wt Ad with respect to uninfected controls. In the in vivo experiments, a total inhibition of tumorigenicity was detected when cells were infected prior to injection and a partial and transitory decrease in tumorigenicity was detected when the mutant H5 dL118 was injected intratumorally. gamma-irradiation enhanced the in vivo antitumor effects.

CONCLUSIONS

These results indicate that infection with completely E1B-deficient Ads induced a marked cytopathic effect on malignant cells that was higher than that seen for wt Ads; in addition, infection with such Ads exerts a tumor suppressor effect in vivo.

Field improvement in a uniaxial centered lens composed of two stacked-volume holographic elements

Arrangements are described for the recording of volume holograms with two sections that, when stacked together, work as uniaxial centered lenses and allow one to solve the problem of angular selectivity in the imaging of wide objects. The performance of such systems is examined qualitatively, and suggestions aimed at improving these designs are proposed.

Urokinase expression and binding activity associated with the transforming growth factor beta1-induced migratory and invasive phenotype of mouse epidermal keratinocytes

Transforming growth factor beta1(TGF-beta1) is a stimulator of malignant progression in mouse skin carcinogenesis. TGF-beta1 exerts a differential effect on cultured nontumorigenic (MCA3D cell line) and transformed (PDV cell line) keratinocytes. Whereas MCA3D cells are growth arrested and committed to die in the presence of the factor, it induces a reversible epithelial-fibroblastic conversion in PDV cells. This conversion is associated in vivo with a squamous-spindle cell carcinoma transition. Here we have investigated the role of urokinase (uPA) during malignant progression of transformed epidermal keratinocytes. We show that the levels of uPA expression/secretion, and the uPA binding activity to the cell surface, correlate with the invasive and malignant potentials of mouse epidermal cell lines. TGF-beta1 enhanced uPA production, the number of uPA cell surface binding sites, and the expression of the plasminogen activator inhibitor PAI-1, in transformed PDV cells, but had no major effect on nontumorigenic MCA3D keratinocytes. Increased uPA production depended on the presence of the factor in the culture medium and occurred concomitantly to the stimulation of the migratory and invasive abilities of PDV cells. Synthetic peptides containing the amino terminal sequence of the mature mouse uPA inhibited the binding of uPA to the cell surface and decreased TGF-beta1-induced cell motility and invasiveness. These results demonstrate that the uPA system mediates at least part of the migratory and invasive phenotype induced by TGF-beta1 in transformed keratinocytes, and suggest a role for uPA on the changes that lead to the appearance of spindle carcinomas.

Digital speckle-pattern interferometry as a full-field fluid-velocimetry technique

We present a novel fluid-velocimetry technique based on speckle interferometry. The light scattered from an illuminated plane is recorded with a CCD camera at the same time as a speckled reference beam. Substraction of two nonsimultaneous frames provides information about the velocity field for an out-of-plane component. An application to a Rayleigh-Bénard convective flow is given.

Transforming growth factor beta 1 induces squamous carcinoma cell variants with increased metastatic abilities and a disorganized cytoskeleton

Previous studies indicated that mouse transformed keratinocytes undergo an epithelial-fibroblastic conversion when cultured in the presence of TGF-beta1. This conversion is associated in vivo with a squamous-spindle carcinoma transition. We derived epithelioid (A6, FPA6) and spindle (B5) clonal cell variants from a squamous carcinoma cell line (PDV) after treatment with TGF-beta1. FPA6 cells were isolated from the ascites fluid of an A6-tumor-bearing mouse. FPA6 and A6 cell lines produced in nude mice mixed carcinomas with a squamous and poorly differentiated component. Both cell lines coexpressed keratins and vimentin and synthesized E-cadherin protein, although FPA6 cells cultured at early passages (FPA6-ep) had reduced levels of E-cadherin mRNA and increased synthesis of keratin K8, a marker of malignant progression. Immunofluorescence analysis revealed that FPA6-ep cells exhibited a disorganized cytoskeleton with keratins forming focal juxtanuclear aggregates and loss of F-actin stress fibers and cortical bundles, and E-cadherin was localized in the cytoplasm out of cell-cell contact areas. Sporadic cells in A6 and PDV cultures also presented those anomalous keratin structures, suggesting that FPA6 cells originated from a subpopulation of A6 tumor cells that metastasized into the peritoneal cavity. The analysis of the spontaneous and experimental metastatic potentials of the cell lines showed that epithelioid and fibroblastic cell variants had acquired metastatic abilities compared to PDV which was nonmetastatic. The FPA6-ep cell line exhibited a highly aggressive behavior, killing the animals at about 17 days after intravenous injection of the cells into athymic mice. The phenotype of FPA6-ep cells was unstable and reverted at later passages in which the normal organization of keratin and F-actin in filaments and the localization of E-cadherin at cell-cell contacts were restored. This phenotypic reversion occurred concomitantly with a reduction of the experimental metastatic potential of FPA6 cells.

Down-regulation of E-cadherin in mouse skin carcinoma cells enhances a migratory and invasive phenotype linked to matrix metalloproteinase-9 gelatinase expression

To assess the role of gelatinases in mouse skin tumor progression and their link to the expression of E-cadherin (E-CD), the cell-cell adhesion protein, we used the highly metastatic squamous HaCa4 cell line and several HaCa4-derived clones obtained by transfection of the mouse E-CD cDNA. Expression of matrix metalloproteinase-9 (MMP-9) mRNA and protein activity were present in E-CD (-) HaCa4 and control clones in culture, but they were strongly diminished in E-CD (+) clones (E24 and E62) at subconfluence. To explore the suppressive effect of the cell-cell contacts mediated by E-CD on MMP-9 expression, we introduced a plasmid encoding mouse E-CD antisense cDNA into the E24 cell clone. The transfectant P1-clones obtained with reduced or absent E-CD expression showed increased levels of MMP-9 gelatinase, motility in vitro, and metastatic potential in vivo. Expression of MMP-9 in the various cell clones was also negatively modulated by cell density, but this effect was much stronger in E-CD (+) cells, despite the fact that all of the cell clones analyzed maintained the expression of P-cadherin and made cell-cell contacts at high cell density. Our results indicate that in this cell system, the E-CD-mediated cell-cell contacts are involved in the down-regulation of MMP-9 expression. Thus, the loss of E-CD triggers a migratory and invasive phenotype in mouse squamous carcinoma cells.

Balancing interpixel cross talk and detector noise to optimize areal density in holographic storage systems

We investigate the effects of interpixel cross talk and detector noise on the areal storage density of holographic data storage. A numerical simulation is used to obtain the bit-error rate (BER) as a function of hologram aperture, pixel fill factors, and additive Gaussian intensity noise. We consider the effect of interpixel cross talk at an output pixel from all possible configurations of its 12 closest-neighbor pixels. Experimental verification of this simulation procedure is shown for several fill-factor combinations. The simulation results show that areal density is maximized when the aperture coincides with the zero order of the spatial light modulator (SLM) (Nyquist sampling condition) and the CCD fill factor is large. Additional numerical analysis including finite SLM contrast and fixed-pattern noise show that, if the fixed-pattern noise reaches 6% of the mean signal level, the SLM contrast has to be larger than 6:1 to maintain high areal density. We also investigate the improvement of areal density when error-prone pixel combinations are forbidden by using coding schemes. A trade-off between an increase in areal density and the redundancy of a coding scheme that avoids isolated-on pixels occurs at a code rate of approximately 83%.

In vivo antitumor effect of retrovirus-mediated gene transfer of the adenovirus E1a gene

The adenovirus E1a gene has been shown to be associated with high sensitivity to DNA-damaging agents and a decrease in the tumorigenicity of some human malignant cell lines. We have analyzed the tumorigenicity of the murine epidermoid carcinoma cell lines MSC11A5 and HaCa4, which have constitutive E1a expression, after the concomitant injection of retrovirus E1a producer cells with the carcinoma cells and even after the intratumoral injection of the E1a producer cells. The level of E1a expression was studied by Western blotting. Tumors induced by carcinoma cell lines expressing E1a showed greater latencies and less tumorigenicity. In the spindle cell carcinomas MSC11A5, E1a gene expression partially blocked tumorigenicity. Similar results were obtained after the concomitant injection of the carcinoma cells and the retrovirus E1a producer cells. Intratumoral injection of retrovirus E1a producer cells was associated with a significant delay of tumorigenicity. By transfection with different E1a mutants Ntd1598, d1922/947, and d1787N, we observed that only the mutant that has complete CR2 domains is associated with the decrease in tumorigenicity. According to these results, we conclude that, at least in these carcinoma cell lines, E1a expression exerts a significant antitumor effect in vivo that is mediated by the CR2 region of E1a gene. We propose that injection of retrovirus E1a producer cells may be a novel therapeutic approach in cancer.

Experimental study of the effects of a six-level phase mask on a digital holographic storage system

We measure the M/# and the bit-error rate of a digital holographic storage system with a 4f optical arrangement for three configurations: recording at the Fourier plane with and without a phase mask and recording outside the Fourier plane without a phase mask. Unexpectedly, no significant change in the dynamic range was observed when a phase mask was used to record in thick crystals. However, we show that a phase mask is a key component in a 4f digital holographic storage system if high-fidelity holograms with optimum volumetric density are to be stored.

Distortionless interferogram recording by use of holographic field lenses for fluid velocimetry

Two optical systems based on holographic field lenses are presented. They have been specifically designed for the CCD camera acquisition of the interferograms obtained from a fluid plane, when one uses holographic interferometry to measure fluid velocities. The use of these systems allows for easy recording of interferograms, all having the same size and position on the CCD, independent of the fluid-plane observation direction. The holographic lenses act as directional field lenses; they change the divergent beam that reaches the lens into a convergent beam that focuses on the camera aperture. These distortionless interferogram recording systems have been demonstrated in a Rayleigh-Bénard convective flow.

Velocity measurements in a convective flow by holographic interferometry

A holographic interferometry technique has been developed that can be used to measure the three components of the velocity field in a whole plane of a fluid flow simultaneously. The light scattered from an illuminated fluid plane is recorded on a hologram. Several interferograms are obtained in the reconstruction of the hologram. Each interferogram is automatically analyzed and produces quantitative information about one velocity component. Parameters that affect the quality of the interferograms are analyzed. The technique is demonstrated in a Rayleigh-Bénard convective flow. Holographic interferometry and particle image velocimetry techniques are compared.

Induction of PA2.26, a cell-surface antigen expressed by active fibroblasts, in mouse epidermal keratinocytes during carcinogenesis

The monoclonal antibody PA2.26, produced against mouse epidermal keratinocytes transformed with 7,12-dimethylbenz[a]anthracene (DMBA), recognizes a 43- to 47-kDa cell-surface protein that was absent from non-tumorigenic epidermal keratinocytes but present in transformed epidermal cell lines as well as cultured normal fibroblasts. In vivo, the antigen was absent from normal epidermis but induced in basal-like epidermal keratinocytes and dermal fibroblasts during tissue regeneration after wounding and treatment with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). The PA2.26 protein was also expressed in basal-like cells of differentiated papillomas and carcinomas generated in mice treated with DMBA and TPA. In addition, the antigen was abundantly synthesized by stromal cells of the tumors. These results suggest that PA2.26 antigen is involved in reactive processes during skin remodeling and carcinogenesis.

Effects of multilevel phase masks on interpixel cross talk in digital holographic storage

We study the interpixel cross talk introduced to digital holographic data storage by use of a multilevel phase mask at the data-input plane. We evaluate numerically the intensity distribution at the output detector for Fourier plane hologram storage in a limited-aperture storage medium. Only the effect at an output pixel of interpixel cross talk from the four horizontal and vertical neighboring pixels is considered, permitting systematic evaluation of all possibilities. For random two-level and pseudorandom six-level phase masks, the influence of the pixel fill factor, as well as the aperture size of the storage medium, is studied. Our simulations show that, for a given aperture size, a random two-level mask is more susceptible to interpixel cross talk than is a pseudorandom six-level mask. Decreasing the pixel fill factor below 94% with a pseudorandom six-level phase mask makes it theoretically possible to have a system with no errors from interpixel cross talk if one particular 5-pixel pattern is forbidden through modulation coding. Reducing the input fill factor below 85% means that no patterns need to be excluded.

Up-regulation of vascular endothelial growth factor/vascular permeability factor in mouse skin carcinogenesis correlates with malignant progression state and activated H-ras expression levels

Angiogenesis is a crucial process for tumor growth and metastasis regulated by the balance of positive and negative factors. Vascular endothelial growth factor (VEGF/VPF) is a specific mitogen for endothelial cells that has been shown to be overexpressed in a variety of tumors and other inflammatory diseases. To analyze the implication of VEGF/VPF during tumorigenesis, we have studied its expression at different stages of tumor development using the mouse skin carcinogenesis model. VEGF/VPF mRNA was induced in skin in vivo after 12-O-tetradecanoylphorbol-13-acetate treatment. Constitutive up-regulation of VEGF/VPF at the mRNA and protein levels was also observed in premalignant papillomas and, at a higher level, in squamous carcinomas, suggesting a correlation between VEGF/VPF expression and tumor progression. A direct positive correlation between VEGF/VPF mRNA expression and the level of activated H-ras gene was found in a series of cell lines representing different stages of epidermal tumor development. Consequently, a clone of one of these cell lines, HaCa4, which has lost most of its v-ras expression, down-regulated VEGF mRNA expression concomitantly with its metastatic potential. Direct evidence of H-ras involvement in VEGF induction was obtained when an immortalized mouse keratinocyte cell line transduced with a retrovirus carrying v-H-ras showed highly increased VEGF/VPF mRNA levels. These data show that in mouse skin carcinogenesis, the VEGF/VPF angiogenic stimulus occurs early during premalignant papilloma development and further increases at later stages. Moreover, we demonstrate that increasing the activated H-ras dose, a phenomenon that takes place sequentially throughout mouse skin tumor development, may play an additional role by facilitating malignant in vivo progression through the modulation of VEGF/VPF-mediated angiogenesis.

Carcinoma cell lines become sensitive to DNA-damaging agents by the expression of the adenovirus E1A gene

Squamous cell carcinomas can show different oncogenic alterations, histological patterns, and an unpredictable clinical behavior. We previously reported that the adenovirus E1a gene may induce sensitivity to DNA-damaging agents in mouse keratinocytes. In order to study whether E1a expression could be used as a therapeutic agent in different malignant cell lines carrying mutations on the p53 gene and other oncogenic alterations, we transfected and infected several murine and human carcinoma cell lines (HaCa4; MSC11A5; HeLa) with vectors containing the 13S or 12S E1a region. We evaluated the sensitivity to cisplatin (CDDP), doxorubicin (DOX) and gamma irradiation (RX) by the crystal violet method. The induction of apoptosis was assessed by flow cytometry and presence of DNA ladders in agarose gels. The expression of E1a and the tumor suppressor p53 protein was analysed by Western blotting. The carcinoma cell lines expressing E1a were about four- to tenfold more sensitive to CDDP and RX, respectively, than the control cells. Moreover, the reduction in cell viability and cell growth after exposure to CDDP or RX was very significant in the carcinoma cells expressing E1a. With these results, we conclude that expression of E1a may confer great sensitivity to DNA-damaging agents on squamous cell carcinoma cells independently of the p53 protein status and other oncogenic alterations.