An Extracellular Matrix Overlay Model for Bioluminescence Microscopy to Measure Single-Cell Heterogeneous Responses to Antiandrogens in Prostate Cancer Cells

Prostate cancer (PCa) displays diverse intra-tumoral traits, impacting its progression and treatment outcomes. This study aimed to refine PCa cell culture conditions for dynamic monitoring of androgen receptor (AR) activity at the single-cell level. We introduced an extracellular matrix-Matrigel (ECM-M) culture model, enhancing cellular tracking during bioluminescence single-cell imaging while improving cell viability. ECM-M notably tripled the traceability of poorly adherent PCa cells, facilitating robust single-cell tracking, without impeding substrate permeability or AR response. This model effectively monitored AR modulation by antiandrogens across various PCa cell lines. Single-cell imaging unveiled heterogeneous antiandrogen responses within populations, correlating non-responsive cell proportions with drug IC50 values. Integrating ECM-M culture with the PSEBC-TSTA biosensor enabled precise characterization of ARi responsiveness within diverse cell populations. Our ECM-M model stands as a promising tool to assess heterogeneous single-cell treatment responses in cancer, offering insights to link drug responses to intracellular signaling dynamics. This approach enhances our comprehension of the nuanced and dynamic nature of PCa treatment responses.

A transcriptional biosensor to monitor single cancer cell therapeutic responses by bioluminescence microscopy

When several life-prolonging drugs are indicated for cancer treatment, predictive drug-response tumor biomarkers are essential to guide management. Most conventional biomarkers are based on bulk tissue analysis, which cannot address the complexity of single-cell heterogeneity responsible for drug resistance. Therefore, there is a need to develop alternative drug response predictive biomarker approaches that could directly interrogate single-cell and whole population cancer cell drug sensitivity. In this study, we report a novel method exploiting bioluminescence microscopy to detect single prostate cancer (PCa) cell response to androgen receptor (AR)-axis-targeted therapies (ARAT) and predict cell population sensitivity.

Methods: We have generated a new adenovirus-delivered biosensor, PCA3-Cre-PSEBC-ITSTA, which combines an integrated two-step transcriptional amplification system (ITSTA) and the activities of the prostate cancer antigen 3 (PCA3) and modified prostate-specific antigen (PSEBC) gene promoters as a single output driving the firefly luciferase reporter gene. This system was tested on PCa cell lines and on primary PCa cells. Single cells, exposed or not to ARAT, were dynamically imaged by bioluminescence microscopy. A linear discriminant analysis (LDA)-based method was used to determine cell population sensitivities to ARAT.

Results: We show that the PCA3-Cre-PSEBC-ITSTA biosensor is PCa-specific and can dynamically monitor single-cell AR transcriptional activity before and after ARAT by bioluminescence microscopy. After biosensor transduction and bioluminescence microscopy single-cell luminescence dynamic quantification, LDA analysis could discriminate the cell populations overall ARAT sensitivity despite heterogeneous single-cell responses. Indeed, the biosensor could detect a significant decrease in AR activity following exposure to conventional ARAT in hormone-naive primary PCa cells, while in castration-resistant PCa patients, treatment response correlated with the observed clinical ARAT resistance.

Conclusion: The exploitation of bioluminescence microscopy and multi-promoter transcriptionally-regulated biosensors can aptly define the overall treatment response of patients by monitoring live single cell drug response from primary cancer tissue. This approach can be used to develop predictive biomarkers for drug response in order to help clinicians select the best drug combinations or sequences for each patient.

Subversion of infiltrating prostate macrophages to a mixed immunosuppressive tumor-associated macrophage phenotype

Tumor-associated macrophages (TAMs) support tumor progression within the tumor microenvironment (TME). Many questions remain as to the origin, development, and function of TAMs within the prostate TME. Evaluation of TAMs in prostate cancer (PCa) patients identified the immunosuppressive TAM marker CD163 in adjacent normal epithelium as an independent predictor of metastases or PCa death. Flow cytometry analyses identified prostate TAMs as frequently expressing both proinflammatory M1 (CCR7+) and immunosuppressive M2 (CD163+) markers. In vitro, we demonstrate PCa cells similarly subvert human M1 macrophages toward a mixed M1/M2 macrophage phenotype favoring tumor growth. Further the cytokine milieu-induced transition between immunosuppressive M2 to proinflammatory M1 (M2→M1) macrophages is abrogated by the presence of PCa cells. RNA sequencing suggests alterations in chemokine expression in prostate TAMs due to the presence of PCa cells. Together, our results suggest that prostate TAMs originate from inflammatory infiltrating macrophages, which are then reprogrammed mainly by PCa cells, but also the cytokine milieu. A better understanding of this subversion of macrophages within the prostate may lead to novel treatment strategies.

Kidney injury molecule-1 inhibits metastasis of renal cell carcinoma

Metastasis is present in approximately 30% of patients diagnosed with renal cell carcinoma (RCC) and is associated with a 5-year survival rate of < 15%. Kidney injury molecule 1 (KIM-1), encoded by the HAVCR1 gene, is a proximal tubule cell-surface glycoprotein and a biomarker for early detection of RCC, but its pathophysiological significance in RCC remains unclear. We generated human and murine RCC cell lines either expressing or lacking KIM-1, respectively, and compared their growth and metastatic properties using validated methods. Surprisingly, KIM-1 expression had no effect on cell proliferation or subcutaneous tumour growth in immune deficient (Rag1^−/−) Balb/c mice, but inhibited cell invasion and formation of lung metastasis in the same model. Further, we show that the inhibitory effect of KIM-1 on metastases was observed in both immune deficient and immune competent mice. Transcriptomic profiling identified the mRNA for the pro-metastatic GTPase, Rab27b, to be downregulated significantly in KIM-1 expressing human and murine RCC cells. Finally, analysis of The Cancer Genome Atlas (TCGA) data revealed that elevated HAVCR1 mRNA expression in the two most common types of RCC, clear cell and papillary RCC, tumours correlated with significantly improved overall patient survival. Our findings reveal a novel role for KIM-1 in inhibiting metastasis of RCC and suggests that tumour-associated KIM-1 expression may be a favourable prognostic factor.

Abstract 2015: A transcriptionally enhanced biosensor to detect and monitor biopsy-dissociated primary prostate cancer single cell drug responses by bioluminescence microscopy

Background: In the past decade, the therapeutic landscape of metastatic castration resistant prostate cancer (mCRPC) has been transformed with the introduction of novel pharmaceutical agents including novel antiandrogens (nAA) such as darolutamide, enzalutamide or apalutamide. Currently, the management of mCRPC is mainly based on biomarkers obtained from the patient's blood or bulk tumor samples, which do not take into account for prostate cancer (PCa) cell heterogeneity.

Objectives: To develop a bioluminescence imaging technology enabling: 1) the detection of PCa single cells from dissociated biopsies and 2) single cell nAA sensitivity assessment.

Methods: The PCA3 promoter (PCa specific) and PSEBC promoter (androgen receptor-driven to monitor response to nAA therapy) have been incorporated in the non-replicating adenoviral multi-promoter integrated two-step transcriptional amplification system (MP-ITSTA) that allows imaging of complementary activities of two different promoters by a single output reporter gene. Thus, PCA3/PSEBC-ITSTA system was designed to monitor androgen receptor (AR) activity specifically within each single PCa cell by bioluminescence microscopy. Prostatic biopsies were dissociated in the presence of collagenase II and DNase for 18h. PCa cell lines or fresh biopsies-dissociated cancer cells were transduced for 72h and then covered with an extracellular matrix gel. Single cell bioluminescence microscopy images were done before and after exposure to DHT or DHT+AA to specifically monitoring therapy response. Changes in cell number and luminescence intensity after AA were normalized to the DHT group to exclude non-specific cell-death due to infection or time spent in culture.

Results: PCA3/PSEBC-ITSTA was specific to PCa cell lines. By determining the ratio of AR active cells before and after DHT or DHT+AA treatment in culture, PCA3-Cre-PSEBC-ITSTA was able to determine the AA sensitivity of LNCaP (sensitive), LAPC4 (moderately resistant) and 22Rv1 (resistant) PCa cell lines. Also, our method could detect and monitor AA sensitivity of primary PCa cells harvested from eight radical prostatectomy specimens. PCA3/PSEBC-ITSTA could dynamically quantify AR transcriptional activity during enzalutamide or bicalutamide treatments, in a dose dependent manner, and could unveil tumor AA response heterogeneity. As expected, inhibition of AR activity was stronger with enzalutamide than with bicalutamide.

Conclusions: Our bioluminescence microscopy-based biosensor could detect primary PCa cells in culture and it allows dynamic evaluation of AA sensitivity at a single-cell level in a heterogeneous cell population harvested from radical prostatectomy biopsies. We believe our approach opens to a novel field of treatment response predictive tools for cancer treatment decision-making.

Citation Format: Audrey Champagne, Pallavi Jain, Bertrand Neveu, Frédéric Pouliot. A transcriptionally enhanced biosensor to detect and monitor biopsy-dissociated primary prostate cancer single cell drug responses by bioluminescence microscopy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2015.

GLUT1 expression in high-risk prostate cancer: Correlation with 18F-FDG-PET/CT and clinical outcome

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Background: Tumour FDG-uptake is of prognostic value in high-risk and metastatic prostate cancer (PCa). The aim of this study is to investigate the underlying glucose metabolism mechanisms of 18F-FDG-uptake on PET/CT imaging in PCa. Methods: Retrospective analysis was conducted for 94 patients diagnosed with a Gleason sum ≥8 at biopsy who underwent 18F-FDG-PET/CT imaging before radical prostatectomy. GLUT1, GLUT12 and HK2 expression were blindly scored after immunohistochemistry on radical prostatectomy specimens by 3 pathologists. 18F-FDG-uptake in primary lesion was measured by a blinded reader using maximum standardized uptake value (SUVmax). Correlations between GLUT1, GLUT12 and HK2 and SUVmax were assessed using Spearman’s rank correlation test. Survival probabilities were based on the Kaplan-Meier method. Results: With a median follow-up of 4.5 years, 56% (n=53) of patients had biochemical recurrence, 7% (n=7) progressed to castration-resistant PCa (CRPC) disease, 13% (n=12) developed metastasis and 6% (n=6) died. Correlation was found between GLUT1 expression and SUVmax level (r=0.2512, p=0.0182). In addition, SUVmax was significantly higher in tumours with high GLUT1 expression (n=17, 5.74±1.67) than tumours with low GLUT1 expression (n=71, 2.68±0.31, P=0.0037). Also, contrary to GLUT12 and HEX2 expression, a significant association was found between GLUT-1 expression levels and SUVmax index (p=0.004), lymph node status (p=0.046), volume of cancer (P=0.013), CRPC-free survival (p=0.02) and metastasis-free survival (p=0.04). Conclusions: GLUT1 expression in PCa tumours correlates with 18F-FDG-uptake and poor prognostic factors. These results suggest that this transporter is involved in the molecular mechanism of 18F-FDG-uptake in high-risk PCa and raise interest in targeting metabolic dependencies of PCa cells as a selective anticancer strategy.

GLUT1 expression in high-risk prostate cancer: correlation with 18F-FDG-PET/CT and clinical outcome

BACKGROUND

Tumour ¹⁸F-FDG-uptake is of prognostic value in high-risk and metastatic prostate cancer (PCa). The aim of this study is to investigate the underlying glucose metabolism mechanisms of ¹⁸F-FDG-uptake on PET/CT imaging in PCa.

METHODS

Retrospective analysis was conducted for 94 patients diagnosed with a Gleason sum ≥8 adenocarcinoma of the prostate at biopsy between July 2011 and July 2014 who underwent ¹⁸F-FDG-PET/CT imaging before radical prostatectomy (RP). ¹⁸F-FDG-uptake in primary lesion was measured by a blinded reader using maximum standardised uptake value (SUV_max). GLUT1, GLUT12 and HK2 expression were blindly scored after immunohistochemistry on specimens RP by three pathologists. Correlations between GLUT1, GLUT12 and HK2, and SUV_max were assessed using Spearman's rank correlation test. Survival probabilities were based on the Kaplan-Meier method.

RESULTS

With a median follow-up of 4.5 years, 56% (n = 53) of patients had biochemical recurrence (BCR), 7% (n = 7) progressed to castration-resistant prostate cancer (CRPC) disease, 13% (n = 12) developed metastasis and 6% (n = 6) died. Correlation was found between GLUT1 expression and SUVmax level (r = 0.25, p = 0.02). In addition, SUV_max was significantly higher in tumours with high GLUT1 expression (n = 17, 5.74 ± 1.67) than tumours with low GLUT1 expression (n = 71, 2.68 ± 0.31, p = 0.004). Moreover, a significant association was found between GLUT1 expression levels and SUV_max level (p = 0.005), lymph node status (p = 0.05), volume of cancer (p = 0.01), CRPC disease progression (p = 0.02) and metastasis development (p = 0.04). No significant difference between GLUT12 and HEX2 expression and SUV_max have been found.

CONCLUSIONS

GLUT1 expression in PCa tumours correlates with ¹⁸F-FDG-uptake and poor prognostic factors. These results suggest that this transporter is involved in the molecular mechanism of ¹⁸F-FDG-uptake in high-risk PCa and raise interest in targeting metabolic dependencies of PCa cells as a selective anticancer strategy.

Cancer-associated fibroblasts induce epithelial-mesenchymal transition of bladder cancer cells through paracrine IL-6 signalling

BACKGROUND

Cancer-associated fibroblasts (CAFs), activated by tumour cells, are the predominant type of stromal cells in cancer tissue and play an important role in interacting with neoplastic cells to promote cancer progression. Epithelial-mesenchymal transition (EMT) is a key feature of metastatic cells. However, the mechanism by which CAFs induce EMT program in bladder cancer cells remains unclear.

METHODS

To investigate the role of CAFs in bladder cancer progression, healthy primary bladder fibroblasts (HFs) were induced into CAFs (iCAFs) by bladder cancer-derived exosomes. Effect of conditioned medium from iCAFs (CM iCAF) on EMT markers expression of non-invasive RT4 bladder cancer cell line was determined by qPCR and Western blot. IL6 expression in iCAFs was evaluated by ELISA and Western blot. RT4 cell proliferation, migration and invasion were assessed in CM iCAF +/- anti-IL6 neutralizing antibody using cyQUANT assay, scratch test and transwell chamber respectively. We investigated IL6 expression relevance for bladder cancer progression by querying gene expression datasets of human bladder cancer specimens from TCGA and GEO genomic data platforms.

RESULTS

Cancer exosome-treated HFs showed CAFs characteristics with high expression levels of αSMA and FAP. We showed that the CM iCAF induces the upregulation of mesenchymal markers, such as N-cadherin and vimentin, while repressing epithelial markers E-cadherin and p-ß-catenin expression in non-invasive RT4 cells. Moreover, EMT transcription factors SNAIL1, TWIST1 and ZEB1 were upregulated in CM iCAF-cultured RT4 cells compared to control. We also showed that the IL-6 cytokine was highly expressed by CAFs, and its receptor IL-6R was found on RT4 bladder cancer cells. The culture of RT4 bladder cancer cells with CM iCAF resulted in markedly promoted cell growth, migration and invasion. Importantly, inhibition of CAFs-secreted IL-6 by neutralizing antibody significantly reversed the IL-6-induced EMT phenotype, suggesting that this cytokine is necessary for CAF-induced EMT in the progression of human bladder cancer. Finally, we observed that IL6 expression is up-regulated in aggressive bladder cancer and correlate with CAF marker ACTA2.

CONCLUSIONS

We conclude that CAFs promote aggressive phenotypes of non-invasive bladder cancer cells through an EMT induced by the secretion of IL-6.

Unmatched speed perceptions between overground and treadmill manual wheelchair propulsion in long-term manual wheelchair users

BACKGROUND

Manual wheelchair (MWC) propulsion is increasingly assessed on a motorized treadmill (TM), which is often considered more ecologically valid than stationary rollers. However, no clear consensus on the similarities between overground (OG) and TM propulsion has yet been reached. Furthermore, no study has investigated the participants' perceptions of propelling a MWC on a TM compared to OG.

RESEARCH QUESTION

The present study aims to assess the perception of speed when propelling on a TM vs OG, and to relate this perception to measured spatiotemporal variables, kinetics and work.

METHODS

In this repeated-measures study, the propulsion's spatiotemporal variables, kinetics, and work of nineteen experienced wheelchair users with a spinal cord injury were compared between three conditions: 1) OG at a self-selected speed, 2) on a TM at a self-selected speed perceived as being similar to the OG speed (TM_perceived), and 3) on a TM at the same speed as OG (TM_matched). Each variable was compared between conditions using an analysis of variance for repeated measures.

RESULTS

All participants selected a lower speed for TM_perceived than OG, with a difference of -0.6 m/s (-44%). This adaptation may be due to a combination of two factors: 1) the absence of speed information, and 2) the feeling of urgency to grab the wheels during the recovery phase. The power output, work per cycle, and work per minute were also much lower on TM_perceived than OG. However, in contrast to other work on MWC propulsion on a TM, the kinetic variables assessed were all similar between the OG and TM_matched conditions.

SIGNIFICANCE

Training on a TM should be performed at a speed that matches the OG speed and not at a self-selected speed on the TM, which would reduce the power output and work and therefore reduce the efficiency of the training.

Abstract LB-018: Cleavage of SNX2 protein by initiator caspases promotes hepatocyte growth factor (MET) receptor tyrosine kinase signaling

Cell death induced by apoptosis involves the stepwise activation of initiator and executioner caspases. Unfolding of this cellular process concurs with caspase-mediated proteolysis of hundreds of proteins with the ultimate result of stopping crucial cell survival, including the intracellular endocytic receptor trafficking. During cancer progression, tumor cells often become resistance to normal death-inducing signals. Typically, this resistance involves a cellular block of the apoptotic cascade downstream of the initiator caspases. Thus, apoptosis-resistant cancer cells are endowed with the unique capacity of sustaining elevated activation of initiator caspases. Apoptosis resistance being critical for metastatic progression, it opens the question of whether the cleavage products of initiator caspases contribute to the metastatic properties of apoptosis-resistant cells.

In a recent study, we identified the SNX1 and SNX2 proteins, which are members of the sorting nexin (SNX) family of proteins critical in the control of endosomal sorting, as initiator caspase substrates. In addition, we demonstrated that the cleavage of SNX2 abolished its endosomal sorting ability, as illustrated by loss of its association with the endosome-to-trans-Golgi network transport protein Vps35 and a delocalization its binding partner Vps26 from endosomes. Importantly, depletion of SNX2 in cells was shown to enhance hepatocyte growth factor-induced phosphorylation of the MET receptor tyrosine kinase (RTK) and that of Erk1/2 proteins. Furthermore, we identified reduced SNX2 mRNA and protein levels in colorectal carcinoma specimens when compared to adjacent normal tissues, and that low SNX2 mRNA expression in primary colorectal tumors correlated with poor survival of patients.

Deregulation of RTK signaling, such as that of the epidermal and hepatocyte growth factor receptors, is known to contribute to metastatic progression. Signaling and biological activity of these cell surface receptors are tightly controlled by their internalization upon activation and trafficking into endosomes, where they are either recycled back to the plasma membrane or degraded in lysosomes. Thus, our novel discoveries suggest that the activation of initiator caspases in apoptosis-resistant cancer cells fosters cancer progression by selective cleavage of proteins involved in RTK endocytic trafficking.

Note: This abstract was not presented at the meeting.

Citation Format: Catherine M. Duclos, Audrey Champagne, Julie C. Carrier, Caroline Saucier, Christine L. Lavoie, Jean-Bernard Denault. Cleavage of SNX2 protein by initiator caspases promotes hepatocyte growth factor (MET) receptor tyrosine kinase signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-018. doi:10.1158/1538-7445.AM2017-LB-018

NLRC5 elicits antitumor immunity by enhancing processing and presentation of tumor antigens to CD8(+) T lymphocytes

Cancers can escape immunesurveillance by diminishing the expression of MHC class-I molecules (MHC-I) and components of the antigen-processing machinery (APM). Developing new approaches to reverse these defects could boost the efforts to restore antitumor immunity. Recent studies have shown that the expression of MHC-I and antigen-processing molecules is transcriptionally regulated by NOD-like receptor CARD domain containing 5 (NLRC5). To investigate whether NLRC5 could be used to improve tumor immunogenicity, we established stable lines of B16-F10 melanoma cells expressing NLRC5 (B16-5), the T cell co-stimulatory molecule CD80 (B16-CD80) or both (B16-5/80). Cells harboring NLRC5 constitutively expressed MHC-I and LMP2, LMP7 and TAP1 genes of the APM. The B16-5 cells efficiently presented the melanoma antigenic peptide gp100_25–33 to Pmel-1 TCR transgenic CD8⁺ T cells and induced their proliferation. In the presence of CD80, B16-5 cells stimulated Pmel-1 cells even without the addition of gp100 peptide, indicating that NLRC5 facilitated the processing and presentation of endogenous tumor antigen. Upon subcutaneous implantation, B16-5 cells showed markedly reduced tumor growth in C57BL/6 hosts but not in immunodeficient hosts, indicating that the NLRC5-expressing tumor cells elicited antitumor immunity. Following intravenous injection, B16-5 and B16-5/80 cells formed fewer lung tumor foci compared to control cells. In mice depleted of CD8⁺ T cells, B16-5 cells formed large subcutaneous and lung tumors. Finally, immunization with irradiated B16-5 cells conferred protection against challenge by parental B16 cells. Collectively, our findings indicate that NLRC5 could be exploited to restore tumor immunogenicity and to stimulate protective antitumor immunity.

Tumour-promoting role of SOCS1 in colorectal cancer cells

The SOCS1 (Suppressor Of Cytokine Signalling 1) protein is considered a tumour suppressor. Notably, the SOCS1 gene is frequently silenced in cancer by hypermethylation of its promoter. Besides blocking inflammation, SOCS1 tumour suppressor activity involves Met receptor inhibition and enhancement of p53 tumour suppressor activity. However, the role of SOCS1 in colorectal cancer (CRC) remains understudied and controversial. Here, we investigated SOCS1 relevance for CRC by querying gene expression datasets of human CRC specimens from The Cancer Genome Atlas (TCGA), and by SOCS1 gain/loss-of-function analyses in murine and human colon carcinoma cells. Our results show that SOCS1 mRNA levels in tumours were more often elevated than reduced with respect to matched adjacent normal tissue of CRC specimens (n = 41). The analysis of TCGA dataset of 431 CRC patients revealed no correlation between SOCS1 expression and overall survival. Overexpression of SOCS1 in CRC cells triggered cell growth enhancement, anchorage-independent growth and resistance to death stimuli, whereas knockdown of SOCS1 reduced these oncogenic features. Moreover, SOCS1 overexpression in mouse CT26 cells increased tumourigenesis in vivo. Biochemical analyses showed that SOCS1 pro-oncogenic activity correlated with the down-modulation of STAT1 expression. Collectively, these results suggest that SOCS1 may work as an oncogene in CRC.

Pushrim biomechanical changes with progressive increases in slope during motorized treadmill manual wheelchair propulsion in individuals with spinal cord injury

The purpose of this study was to quantify the effects of five distinct slopes on spatiotemporal and pushrim kinetic measures at the nondominant upper limb during manual wheelchair (MWC) propulsion on a motorized treadmill in individuals with spinal cord injury (SCI). Eighteen participants with SCI propelled their MWC at a self-selected natural speed on a treadmill at different slopes (0, 2.7, 3.6, 4.8, and 7.1 degrees). Spatiotemporal parameters along with total force and tangential components of the force applied to the pushrim, including mechanical effective force, were calculated using an instrumented wheel. The duration of the recovery phase was 54% to 70% faster as the slope increased, whereas the duration of the push phase remained similar. The initial contact angles migrated forward on the pushrim, while the final and total contact angles remained similar as the slope increased. As the slope increased, the mean total force was 93% to 201% higher and the mean tangential component of the force was 96% to 176% higher than propulsion with no slope. Measures were similar for the 2.7 and 3.6 degrees slopes. Overall, the recovery phase became shorter and the forces applied at the pushrim became greater as the slope of the treadmill increased during motorized treadmill MWC propulsion.

New determination of the astrophysical S factor SE1 of the 12C(alpha,gamma)16O reaction

A new measurement of the beta-delayed alpha decay of 16N has been performed using a set of high efficiency ionization chambers. Sources were made by implantation of a 16N beam, yielding very clean alpha spectra down to energies as low as 400 keV. Our data are in good agreement with earlier results. For the S factor S(E1), we obtain a value of 74 +/- 21 keV b. In spite of improvements in the measurement, the error in S(E1) remains relatively large because of the correlations among the fit parameters and the uncertainties inherent to the extrapolation.

[Management of lymphedema: experience of the Cognacq-Jay Hospital]

Treatment of lymphedema includes practical advices, manual lymph drainage, bandaging, self-bandaging, elastic compression garment, skin care and physical exercises. Weight loss may be useful if obesity. Surgery is indicated in genital lymphedema more than in limb lymphedema. In 2001, in Lymphology Unit, 248 women were treated for secondary upper limb lymphedema after breast cancer. Excess of volume of lymphedema was reduced by 31.3% after a mean time of 2.1 weeks. For lower limb lymphedema (primary or secondary), 136 patients were treated with a mean reduction of excess of lymphedema by 29.8% after a mean time of 2.2 weeks. After this treatment, long term follow-up is necessary to maintain results and the motivation of the patient.

Proteolytic activity of bacteria isolated from the oral cavities of BALB/c mice toward salivary proteins

The proteolytic activities of 350 bacterial isolates from different sites (saliva, tongue, teeth, and mucosa) of the oral cavities of BALB/c mice were tested against different proteins found in saliva (immunoglobulins A, M, G, albumin, lysozyme, mucin, lactoferrin, and lactoperoxidase), some of which are considered to possess antibacterial activity. The results indicate that: (1) lysozyme, lactoferrin, and lactoperoxidase are hydrolyzed by from 46 to 70% of the indigenous flora of the oral cavities of BALB/c mice; (2) IgA and IgM appeared less sensitive to the proteolytic activities of these strains than did the other proteins tested; (3) the colonization of the oral cavity does not seem to be correlated with the proteolytic activity; and (4) the presence of specific Ig proteases is relatively scarce within this population.