Afamitresgene autoleucel for advanced synovial sarcoma and myxoid round cell liposarcoma (SPEARHEAD-1): an international, open-label, phase 2 trial.

BACKGROUND: Afamitresgene autoleucel (afami-cel) showed acceptable safety and promising efficacy in a phase 1 trial (NCT03132922). The aim of this study was to further evaluate the efficacy of afami-cel for the treatment of patients with HLA-A*02 and MAGE-A4-expressing advanced synovial sarcoma or myxoid round cell liposarcoma. METHODS: SPEARHEAD-1 was an open-label, non-randomised, phase 2 trial done across 23 sites in Canada, the USA, and Europe. The trial included three cohorts, of which the main investigational cohort (cohort 1) is reported here. Cohort 1 included patients with HLA-A*02, aged 16-75 years, with metastatic or unresectable synovial sarcoma or myxoid round cell liposarcoma (confirmed by cytogenetics) expressing MAGE-A4, and who had received at least one previous line of anthracycline-containing or ifosfamide-containing chemotherapy. Patients received a single intravenous dose of afami-cel (transduced dose range 1·0 × 109-10·0 × 109 T cells) after lymphodepletion. The primary endpoint was overall response rate in cohort 1, assessed by a masked independent review committee using Response Evaluation Criteria in Solid Tumours (version 1.1) in the modified intention-to-treat population (all patients who received afami-cel). Adverse events, including those of special interest (cytokine release syndrome, prolonged cytopenia, and neurotoxicity), were monitored and are reported for the modified intention-to-treat population. This trial is registered at ClinicalTrials.gov, NCT04044768; recruitment is closed and follow-up is ongoing for cohorts 1 and 2, and recruitment is open for cohort 3. FINDINGS: Between Dec 17, 2019, and July 27, 2021, 52 patients with cytogenetically confirmed synovial sarcoma (n=44) and myxoid round cell liposarcoma (n=8) were enrolled and received afami-cel in cohort 1. Patients were heavily pre-treated (median three [IQR two to four] previous lines of systemic therapy). Median follow-up time was 32·6 months (IQR 29·4-36·1). Overall response rate was 37% (19 of 52; 95% CI 24-51) overall, 39% (17 of 44; 24-55) for patients with synovial sarcoma, and 25% (two of eight; 3-65) for patients with myxoid round cell liposarcoma. Cytokine release syndrome occurred in 37 (71%) of 52 of patients (one grade 3 event). Cytopenias were the most common grade 3 or worse adverse events (lymphopenia in 50 [96%], neutropenia 44 [85%], leukopenia 42 [81%] of 52 patients). No treatment-related deaths occurred. INTERPRETATION: Afami-cel treatment resulted in durable responses in heavily pre-treated patients with HLA-A*02 and MAGE-A4-expressing synovial sarcoma. This study shows that T-cell receptor therapy can be used to effectively target solid tumours and provides rationale to expand this approach to other solid malignancies. FUNDING: Adaptimmune.

Single surgeon versus co-surgeon bilateral mastectomy: Comparing outcomes and costs based on health economic modeling from the perspective of the hospital system.

INTRODUCTION: Co-surgeon approach for bilateral mastectomy may lead to shorter operative times and improved outcomes compared with single-surgeon approach, but cost differences remain unclear. Economic models were applied to determine whether either approach offered a lower cost opportunity. METHODS: A retrospective review of 409 patients undergoing single-surgeon or co-surgeon bilateral mastectomy between January 1, 2010 through April 30, 2016 was conducted. Outcomes included narcotic and antinausea doses, length of stay (LOS), and operative time. Analyses stratified by reconstruction and no reconstruction included Wilcoxon tests, Poisson regression, generalized linear models, and a cost calculator. RESULTS: Of 409 patients, 310 had reconstruction and 99 had no reconstruction. Compared with single-surgeon approach, co-surgeon approach was associated with less operative time and shorter LOS (233 vs. 250 min and 1.0 vs. 1.8 days no reconstruction; and 429 vs. 493 min and 2.2 vs. 2.8 days reconstruction). Economic analysis demonstrated less operative time, shorter LOS, and lower average cost for co-surgeon approach ($32,400 vs. $34,400 no reconstruction; and $76,700 vs. $79,400 reconstruction). CONCLUSION: Compared with the single-surgeon, the co-surgeon approach with reconstruction was associated with a statistically significant decrease in operative time and LOS. Economic analysis estimated the co-surgeon approach could lead to lower costs.

Dominant effect of gap junction communication in wound-induced calcium-wave, NFAT activation and wound closure in keratinocytes.

Wounding induces a calcium wave and disrupts the calcium gradient across the epidermis but mechanisms mediating calcium and downstream signalling, and longer-term wound healing responses are incompletely understood. As expected, live-cell confocal imaging of Fluo-4-loaded normal human keratinocytes showed an immediate increase in [Ca2+ ]i at the wound edge that spread as a calcium wave (8.3 µm/s) away from the wound edge with gradually diminishing rate of rise and amplitude. The amplitude and area under the curve of [Ca2+ ]i flux was increased in high (1.2 mM) [Ca2+ ]o media. 18α-glycyrrhetinic acid (18αGA), a gap-junction inhibitor or hexokinase, an ATP scavenger, blocked the wound-induced calcium wave, dependent in part on [Ca2+ ]o . Wounding in a high [Ca2+ ]o increased nuclear factor of activated T-cells (NFAT) but not NFkB activation, assessed by dual-luciferase receptor assays compared to unwounded cells. Treatment with 18αGA or the store-operated channel blocker GSK-7975A inhibited wound-induced NFAT activation, whereas treatment with hexokinase did not. Real-time cell migration analysis, measuring wound closure rates over 24 h, revealed that 18αGA essentially blocked wound closure whereas hexokinase and GSK-7975A showed relatively minimal effects. Together these data indicate that while both gap-junction communication and ATP release from damaged cells are important in regulating the wound-induced calcium wave, long-term transcriptional and functional responses are dominantly regulated by gap-junction communication.

Individual and combined effects of the infrared, visible, and ultraviolet light components of solar radiation on damage biomarkers in human skin cells.

The ability of solar ultraviolet (UV) to induce skin cancer and photoaging is well recognized. The effect of the infrared (IR) and visible light (Vis) components of solar radiation on skin and their interaction with UV is less well known. This study compared the effects of physiologically relevant doses of complete (UV + Vis + IR) solar-simulated light and its individual components on matched primary dermal fibroblasts and epidermal keratinocytes from human donors on three biomarkers of cellular damage (reactive oxygen species (ROS) generation, mitochondrial DNA (mtDNA), and nuclear DNA (nDNA) damage). There was a greater induction of ROS, mtDNA, and nDNA damage with the inclusion of the visible and IR components of solar-simulated light in primary fibroblast cells compared to primary keratinocytes (P < .001). Experiments using exposure to specific components of solar light alone or in combination showed that the UV, Vis, and IR components of solar light synergistically increased ROS generation in primary fibroblasts but not primary keratinocytes (P < .001). Skin cell lines were used to confirm these findings. These observations have important implications for different skin cell type responses to the individual and interacting components of solar light and therefore photodamage mechanisms and photoprotection interventions.

Radiographic Surveillance of Patients with Non-BRCA1/2 Pathogenic Variants.

INTRODUCTION: The National Comprehensive Cancer Network (NCCN) developed clinical practice guidelines for germline pathogenic variants in highly penetrant genes, such as TP53 and PTEN, and in moderately penetrant genes, such as CHEK2, ATM and PALB2. Whether the practice of radiographic surveillance of patients with pathogenic variants in genes other than BRCA1/2 complies with current NCCN guidelines remains unclear. METHODS: Retrospective review of patients identified with pathogenic variants in genes other than BRCA1/2 from 2007 through 2017 to determine if radiographic surveillance was in accordance with NCCN guidelines for mammography and consideration of magnetic resonance imaging (MRI). Exclusions included variants of unknown significance, pathogenic variants not associated with an increased risk of breast cancer, and previous breast cancer diagnosis. RESULTS: After exclusions, 35 patients with pathogenic variants in ATM, CDH1, CHEK2, NBN, PALB2, PTEN, and STK11 genes were reviewed to assess whether radiographic surveillance was in accordance with NCCN guidelines. Guidelines for those with variants in ATM, CHEK2 and NBN includes annual mammography with tomosynthesis and consideration of breast MRI at age 40, variants in CDH1 and PALB2 at age 30, variants in PTEN at age 30-35 or 5-10 years before the earliest family breast cancer, and variants in STK11 at age 25. Of these 35 patients, 11 (31%) received mammography only; 11 (31%) received mammography and MRI, and 13 (37%) received no radiographic surveillance. Two of the 35 (6%) patients who received radiographic surveillance were diagnosed with ductal carcinoma in situ or invasive breast cancer. CONCLUSION: Thirty-one percent of patients with pathogenic variants in genes other than BRCA1/2 received both mammography and MRI. Thirty-seven percent of patients with these highly penetrant and moderately penetrant genes received no radiographic follow-up, clearly demonstrating an opportunity for improvement.

Who Gets What? Describing the Non-supervisory Training and Supports Received by Home Visiting Staff Members and its Relationship with Turnover.

The early childhood home visiting field lacks a basic understanding of home visiting program staff members' receipt of on-the-job training from experts outside of their programs who are not their immediate colleagues or supervisors. To address this gap, we created a unique dataset by asking program leaders to log the external technical assistance (TA) that staff members received, and we collected a survey from 288 of the same staff members. We performed descriptive analyses to learn how many hours of TA staff members were receiving, what topics the TA most commonly addressed, and what formats (e.g., in-person or virtual/remote, individual, or group) the TA was most commonly provided in. We then associated characteristics of the TA received with staff and program characteristics, as well as with staff members' turnover. Multilevel analyses showed the TA supports that home visiting staff members received differed by role (home visitor or supervisor) and program characteristics, including home visiting model-Nurse Family Partnership (NFP) or Parents as Teachers (PAT)-program size, and maturity. About 23% of the home visiting staff members left their programs over the course of 18 months. PAT staff members were more likely to leave their programs than NFP staff members. We did not find that characteristics of TA received were predictive of staff members' turnover. Implications and the need for further research are discussed.

Bad air gets under your skin.

Air pollution is increasing beyond previous estimates and is viewed as the world's largest environmental health risk factor. Numerous clinical and epidemiological studies have highlighted the adverse effects of environmental pollutants on health. Although there is comparatively less research investigating the cutaneous effects of ambient pollution, there is growing recognition of the adverse effects on skin. In this article, we provide an overview of the nature of environmental pollution and highlight the current evidence detailing the effects on cutaneous health. There is convincing evidence demonstrating that air pollution has a detrimental impact on skin and can exacerbate skin disease. Further epidemiological and experimental studies are required to assess the short- and long-term deleterious effects of ambient pollutant exposure on skin. The future challenge would be to use this evidence to develop specific strategies to protect against pollution-induced damage and prevent the effects of "bad air getting under our skin."

Assessment of the protective effect of Imvamune and Acam2000 vaccines against aerosolized monkeypox virus in cynomolgus macaques.

To support the licensure of a new and safer vaccine to protect people against smallpox, a monkeypox model of infection in cynomolgus macaques, which simulates smallpox in humans, was used to evaluate two vaccines, Acam2000 and Imvamune, for protection against disease. Animals vaccinated with a single immunization of Imvamune were not protected completely from severe and/or lethal infection, whereas those receiving either a prime and boost of Imvamune or a single immunization with Acam2000 were protected completely. Additional parameters, including clinical observations, radiographs, viral load in blood, throat swabs, and selected tissues, vaccinia virus-specific antibody responses, immunophenotyping, extracellular cytokine levels, and histopathology were assessed. There was no significant difference (P > 0.05) between the levels of neutralizing antibody in animals vaccinated with a single immunization of Acam2000 (132 U/ml) and the prime-boost Imvamune regime (69 U/ml) prior to challenge with monkeypox virus. After challenge, there was evidence of viral excretion from the throats of 2 of 6 animals in the prime-boost Imvamune group, whereas there was no confirmation of excreted live virus in the Acam2000 group. This evaluation of different human smallpox vaccines in cynomolgus macaques helps to provide information about optimal vaccine strategies in the absence of human challenge studies.

1 or 2 cm margins of excision for T2 melanomas: do they impact recurrence or survival?

BACKGROUND: NCCN guidelines recommend 1 or 2 cm margins for melanomas 1-2 mm (T2 melanomas) in depth; however, no head-to-head comparison has been performed. We hypothesized 1- or 2-cm margins would have similar local recurrence (LR) and overall survival (OS). METHODS: An institutional database was queried for patients with 1.0-2.0 mm melanomas treated from July 1995 to January 2011. All had wide excision and sentinel lymph node biopsy. Patients without documented surgical margins or follow-up were excluded. Clinicopathologic and recurrence data were reviewed. Univariate and multivariate analyses were performed. RESULTS: Of 2,118 patients, 1,225 met study criteria. Of these, 576 had complete data: 224 (38.9%) had 1 cm margins and 352 (61.1%), 2 cm margins. Median follow-up was 38 months. Mean age was 52.6 years (range 11.3-86.7). Mean thickness was 1.27 and 1.48 mm (1 and 2 cm, respectively, p<0.001) with ulceration more common in the 2 cm group (12.3 and 21.3%, respectively; p=0.009). LR was 3.6 and 0.9% in the 1 cm versus 2 cm group, respectively (p=0.044). OS was 29.1 months with 1 cm and 43.7 months in the 2 cm group. On multivariate analysis, only head and neck location and nodal status were associated with overall survival. CONCLUSIONS: In this series, 1 cm margins were associated with a small increase in LR that did not impact OS. This is concordant with the NCCN recommendations; however, a prospective, randomized trial would be optimal.

Teenage dating abuse, rape, and violence: The dermatologist's role.

Teenage dating abuse, rape, and violence are considered major public health problems that affect the lives of millions of teenagers in the United States. Dermatologists have traditionally become involved in these cases when confronted with patients who have unexplained bruising or other skin injuries and/or sexually transmitted diseases that raise the possibility that they could be victims of sexual abuse and violence. This contribution explores the role of the dermatologist in the diagnosis and management of teen dating abuse. We suggest some screening questions that might help to broach these serious issues with teen patients when the suspicion of dating abuse arises. We also provide a list of resources and hotlines that offer advice on how best to handle teen dating abuse. Some legal issues concerning the physician's role in managing teen dating abuse, rape, and violence are also discussed.

Recombinant expression of homodimeric 660 kDa human thyroglobulin in soybean seeds: an alternative source of human thyroglobulin.

Soybean seeds possess many qualities that make them ideal targets for the production of recombinant proteins. However, one quality often overlooked is their ability to stockpile large amounts of complex storage proteins. Because of this characteristic, we hypothesized that soybean seeds would support recombinant expression of large and complex proteins that are currently difficult or impossible to express using traditional plant and non-plant-based host systems. To test this hypothesis, we transformed soybeans with a synthetic gene encoding human thyroglobulin (hTG)-a 660 kDa homodimeric protein that is widely used in the diagnostic industry for screening and detection of thyroid disease. In the absence of a recombinant system that can produce recombinant hTG, research and diagnostic grade hTG continues to be purified from cadaver and surgically removed thyroid tissue. These less-than-ideal tissue sources lack uniform glycosylation and iodination and therefore introduce variability when purified hTG is used in sensitive ELISA screens. In this study, we report the successful expression of recombinant hTG in soybean seeds. Authenticity of the soy-derived protein was demonstrated using commercial ELISA kits developed specifically for the detection of hTG in patient sera. Western analyses and gel filtration chromatography demonstrated that recombinant hTG and thyroid-purified hTG are biologically similar with respect to size, mass, charge and subunit interaction. The recombinant protein was stable over three generations and accumulated to ~1.5% of total soluble seed protein. These results support our hypothesis that soybeans represent a practical alternative to traditional host systems for the expression of large and complex proteins.

Expression of the NS3 protease of cytopathogenic bovine viral diarrhea virus results in the induction of apoptosis but does not block activation of the beta interferon promoter.

Bovine viral diarrhea virus (BVDV; genus Pestivirus) can exist as two biotypes, cytopathogenic (CP) and non-cytopathogenic (NCP). The CP form differs from NCP by the continual expression of free non-structural protein 3 (NS3). CP BVDV infection of cultured cells induces apoptosis, whereas NCP BVDV infection has been reported to block the induction of beta interferon (IFN-beta). To investigate the viral mechanisms underlying these effects, NS3 or NS2-3 proteins of NCP and CP BVDV biotypes, together with the cognate NS3 co-factor NS4A, were expressed in cells, and their effect on apoptosis and induction of IFN-beta was investigated. Expression of NS3/4A resulted in increased activity of caspase-9 and caspase-3, indicating induction of the intrinsic apoptosis pathway. Mutational analysis revealed that a protease-inactive NS3/4A was unable to induce apoptosis, suggesting that NS3 protease activity is required for initiation of apoptosis during CP BVDV infection. The ability of NS2-3 to modulate activation of the IFN-beta promoter was also investigated. These studies confirmed that, unlike the related hepatitis C virus and GB virus-B, BVDV proteases are unable to inhibit TLR3- and RIG-I-dependent activation of the IFN-beta promoter. These data suggest that BVDV NS3/4A is responsible for regulating the levels of cellular apoptosis and provide new insights regarding the viral elements associated with CP biotype pathogenesis.

Universal surfactant for water, oils, and CO2.

A trichain anionic surfactant sodium 1,4-bis(neopentyloxy)-3-(neopentyloxycarbonyl)-1,4-dioxobutane-2-sulfonate (TC14) is shown to aggregate in three different types of solvent: water, heptane, and liquid CO(2). Small-angle neutron scattering (SANS) has been used to characterize the surfactant aggregates in water, heptane, and dense CO(2). Surface tension measurements, and analyses, show that the addition of a third branched chain to the surfactant structural template is critical for sufficiently lowering the surface energy, tipping the balance between a CO(2)-incompatible surfactant (AOT) and CO(2)-philic compounds that will aggregate to form micelles in dense CO(2) (TC14). These results highlight TC14 as one of the most adaptable and useful surfactants discovered to date, being compatible with a wide range of solvent types from high dielectric polar solvent water to alkanes with low dielectrics and even being active in the uncooperative and challenging solvent environment of liquid CO(2).

Domestic violence in the coronavirus disease 2019 era: Insights from a survivor.

Amid the coronavirus disease 2019 (COVID-19) pandemic, there has been an alarming rise in domestic violence worldwide. Factors believed to be fueling this escalation in domestic violence include increasing social confinement at home during lockdowns and mounting stress levels from unemployment that have resulted from the economic uncertainties of these times. This contribution explores some of the challenges faced by physicians in clinically assessing victims of domestic violence during the COVID-19 era. One such challenge is the increased reliance on telemedicine during the pandemic, a medium of communication that offers a narrower clinical view of patients than is what is usually provided by an in-person examination. In this contribution, we offer suggestions on how best to screen for domestic violence, whether through telemedicine or during an in-person encounter. The history and physical findings that suggest domestic violence are reviewed along with recommendations on how to make the clinical examination more sensitive and compassionate to the needs of the victims. One of the authors of this contribution (L.C.H.) is herself a survivor of domestic violence and has courageously shared, in these pages, details of her harrowing near murder by an abusing husband. From this case history, it is hoped that readers will gain wider insights into what domestic violence means from the perspective of a victim and how we can better help save victims from this widespread and devastating social problem.

Escape from HLA-B*08-restricted CD8 T cells by hepatitis C virus is associated with fitness costs.

The inherent sequence diversity of the hepatitis C virus (HCV) represents a major hurdle for the adaptive immune system to control viral replication. Mutational escape within targeted CD8 epitopes during acute HCV infection has been well documented and is one possible mechanism for T-cell failure. HLA-B*08 was recently identified as one HLA class I allele associated with spontaneous clearance of HCV replication. Selection of escape mutations in the immunodominant HLA-B*08-restricted epitope HSKKKCDEL(1395-1403) was observed during acute infection. However, little is known about the impact of escape mutations in this epitope on viral replication capacity. Their previously reported reversion back toward the consensus residue in patients who do not possess the B*08 allele suggests that the consensus sequence in this epitope is advantageous for viral replication in the absence of immune pressure. The aim of this study was to determine the impact of mutational escape from this immunodominant epitope on viral replication. We analyzed it with a patient cohort with chronic HCV genotype 1b infection and in a single-source outbreak (genotype 1b). Sequence changes in this highly conserved region are rare and selected almost exclusively in the presence of the HLA-B*08 allele. When tested in the subgenomic replicon (Con1), the observed mutations reduce viral replication compared with the prototype sequence. The results provide direct evidence that escape mutations in this epitope are associated with fitness costs and that the antiviral effect of HLA-B*08-restricted T cells is sufficiently strong to force the virus to adopt a relatively unfavorable sequence.

Conventional and PCR Detection of Aphelenchoides fragariae in Diverse Ornamental Host Plant Species.

A PCR-based diagnostic assay was developed for early detection and identification of Aphelenchoides fragariae directly in host plant tissues using the species-specific primers AFragFl and AFragRl that amplify a 169-bp fragment in the internal transcribed spacer (ITS1) region of ribosomal DNA. These species-specific primers did not amplify DNA from Aphelenchoides besseyi or Aphelenchoides ritzemabosi. The PCR assay was sensitive, detecting a single nematode in a background of plant tissue extract. The assay accurately detected A. fragariae in more than 100 naturally infected, ornamental plant samples collected in North Carolina nurseries, garden centers and landscapes, including 50 plant species not previously reported as hosts of Aphelenchoides spp. The detection sensitivity of the PCR-based assay was higher for infected yet asymptomatic plants when compared to the traditional, water extraction method for Aphelenchoides spp. detection. The utility of using NaOH extraction for rapid preparation of total DNA from plant samples infected with A. fragariae was demonstrated.

Recent advances in nanoparticle synthesis with reversed micelles.

Synthesis of nanoparticles in microemulsions is an area of considerable current interest. This subject can be broadly divided into two sections defined by the nature of the host microemulsion reaction medium. Water-in-oil microemulsions have been used to prepare nanoparticles for more than two decades, and a wide variety of materials has been synthesised by these methods. Control parameters have been elucidated for influencing both nanoparticle concentration and morphology, allowing for tailored syntheses with various applications. More recently, the ability to synthesise nanoparticles in water/supercritical fluid microemulsions was realised. This method promises to be a highly useful route for controlled nanoparticle synthesis due to the added control variables afforded by tuneability of the solvent quality (density) through pressure and temperature. This review presents the current state-of-the-art in both fields.

Leukocyte Ig-Like Receptors - A Model for MHC Class I Disease Associations.

MHC class I (MHC-I) polymorphisms are associated with the outcome of some viral infections and autoimmune diseases. MHC-I proteins present antigenic peptides and are recognized by receptors on natural killer cells and cytotoxic T lymphocytes, thus enabling the immune system to detect self-antigens and eliminate targets lacking self or expressing foreign antigens. Recognition of MHC-I, however, extends beyond receptors on cytotoxic leukocytes. Members of the leukocyte Ig-like receptor (LILR) family are expressed on monocytic cells and can recognize both classical and non-classical MHC-I alleles. Despite their relatively broad specificity when compared to the T cell receptor or killer Ig-like receptors, variations in the strength of LILR binding between different MHC-I alleles have recently been shown to correlate with control of HIV infection. We suggest that LILR recognition may mediate MHC-I disease association in a manner that does not depend on a binary discrimination of self/non-self by cytotoxic cells. Instead, the effects of LILR activity following engagement by MHC-I may represent a "degrees of self" model, whereby strength of binding to different alleles determines the degree of influence exerted by these receptors on immune cell functions. LILRs are expressed by myelomonocytic cells and lymphocytes, extending their influence across antigen-presenting cell subsets including dendritic cells, macrophages, and B cells. They have been identified as important players in the response to infection, inflammatory diseases, and cancer, with recent literature to indicate that MHC-I recognition by these receptors and consequent allelic effects could extend an influence beyond the immune system.

Mitochondrial damage and ageing using skin as a model organ.

Ageing describes the progressive functional decline of an organism over time, leading to an increase in susceptibility to age-related diseases and eventually to death, and it is a phenomenon observed across a wide range of organisms. Despite a vast repertoire of ageing studies performed over the past century, the exact causes of ageing remain unknown. For over 50 years it has been speculated that mitochondria play a key role in the ageing process, due mainly to correlative data showing an increase in mitochondrial dysfunction, mitochondrial DNA (mtDNA) damage, and reactive oxygen species (ROS) with age. However, the exact role of the mitochondria in the ageing process remains unknown. The skin is often used to study human ageing, due to its easy accessibility, and the observation that the ageing process is able to be accelerated in this organ via environmental insults, such as ultra violet radiation (UVR). This provides a useful tool to investigate the mechanisms regulating ageing and, in particular, the role of the mitochondria. Observations from dermatological and photoageing studies can provide useful insights into chronological ageing of the skin and other organs such as the brain and liver. Moreover, a wide range of diseases are associated with ageing; therefore, understanding the cause of the ageing process as well as regulatory mechanisms involved could provide potentially advantageous therapeutic targets for the prevention or treatment of such diseases.

Transgene dispersal through pollen.

Techniques used for the transfer of novel genes into host plant genomes have created new possibilities for crop improvement. The implementation of transgenic crop species into agriculture has introduced the possibility of transgene escape into the environment via pollen dispersal. Although the movement of pollen is a critical step in transgene escape, there is currently no system to monitor transgenic pollen movement under field conditions. The development of an effective in vivo monitoring system suitable for use under field conditions is needed for research and commercial purposes so potential risks can be quantified and evaluated. This chapter describes the development of a model system using green fluorescent protein (GFP) expression in pollen as a marker to monitor pollen distribution patterns. A pollen specific promoter was used to express the GFP gene in tobacco (Nicotiana tabacum L.). GFP was visualized in pollen and growing pollen tubes using fluorescent microscopy. Furthermore, the goal of this research was to compare the dynamics of pollen movement with that of gene flow by using another method of whole plant expression of GFP to estimate out-crossing frequencies by progeny analysis. Pollen movement and gene flow were quantified under field conditions. Pollen traps were collected and screened for presence of GFP-tagged pollen using fluorescence microscopy. Progeny from wild type plants were screened with a hand held ultraviolet light for detection of the GFP phenotype.