The Role of Olive Tree Polyphenols in the Prevention of COVID-19: A Scoping Review, part 1

Abstract

The global COVID-19 outbreak, started in December 2019, resulted in severe financial losses and extraordinary health crises. Finding a potent and secure medication candidate to treat SARS-CoV-2 infection and its symptoms is still an urgent global need. After reviewing previous studies, olive leaves, being rich in polyphenolic compounds (a large class of bioactive substances naturally found in plants), were proposed as a viable co-therapy supplement to treat and improve clinical symptoms in COVID-19 patients. It has long been known that olive tree polyphenols-such as oleuropein, hydroxytyrosol, verbascoside, as well as triterpenoids like maslinic, ursolic, and oleanolic acids-have anti-inflammatory and multitarget antiviral effects on several virus families, and they could be one of the reasons of the beneficial effects of the Mediterranean diet against COVID-19. Thus, olive tree poly-phenols were tested in silico and in vitro for preventing SARS-CoV-2 infection, claiming that they have beneficial effects. Nevertheless, there is still a small number of research studies on this topic. The aim of this scoping review is to provide more information and offer an opinion on the feasibility of using olive tree polyphenols as a springboard for the creation of innovative natural remedies against this viral illness, ultimately planning future relevant studies.

Nutrigenomics: SNPs correlated to minerals' deficiencies

Abstract

Nutrigenetics and nutrigenomics are two interrelated fields that explore the influence of genetic diversity on nutrient responses and function. While nutrigenetics investigates the effects of hereditary ge-netic variations on micronutrient metabolism, nutrigenomics examines the intricate relationship between diet and the genome, studying how genetic variants impact nutrient intake and gene expression. These disciplines offer valuable insights into predicting and managing chronic diseases through personalized nutritional approaches. Nutrigenomics employs cutting-edge genomics technologies to study nutrient-genome interactions. Key principles involve genetic variability among ethnic groups, affecting nutrient bioavailability and metabolism, and the influence of dietary choices based on cultural, geographic, and socioeconomic factors. Polymorphisms, particularly single-nucleotide polymorphisms (SNPs), significantly influence gene activity and are associated with specific phenotypes that are related to micronutrient deficiencies. Minerals are inorganic elements, vital for various physiological functions. Understanding the SNPs associated with mineral deficien-cies is crucial for assessing disease risk and developing personalized treatment plans. This knowledge can inform public health interventions, targeted screening programs, educational campaigns, and fortified food products to address deficiencies effectively. Nutrigenomics research has the potential to revolutionize clinical and nutritional practices, providing personalized recommendations, enhancing illness risk assessment, and advancing public health initiatives. Despite the need for further research, harnessing nutrigenomics' potential can lead to more focused and efficient methods for preventing and treating mineral deficiencies.

Nutrigenomics: SNPs Correlated to Lipid and Carbohydrate Metabolism

Background

Nutrigenomics - the study of the interactions between genetics and nutrition - has emerged as a pivotal field in personalized nutrition. Among various genetic variations, single-nucleotide polymorphisms (SNPs) have been extensively studied for their probable relationship with metabolic traits.

Methods

Throughout this review, we have employed a targeted research approach, carefully handpicking the most representative and relevant articles on the subject. Our methodology involved a systematic review of the scientific literature to ensure a comprehensive and accurate overview of the available sources.

Results

SNPs have demonstrated a significant influence on lipid metabolism, by impacting genes that encode for enzymes involved in lipid synthesis, transport, and storage. Furthermore, they have the ability to affect enzymes in glycolysis and insulin signaling pathways: in a way, they can influence the risk of type 2 diabetes. Thanks to recent advances in genotyping technologies, we now know numerous SNPs linked to lipid and carbohydrate metabolism. The large-scale studies on this topic have unveiled the potential of personalized dietary recommendations based on an individual's genetic makeup. Personalized nutritional interventions hold promise to mitigate the risk of various chronic diseases; however, translating these scientific insights into actionable dietary guidelines is still challenging.

Conclusions

As the field of nutrigenomics continues to evolve, collaborations between geneticists, nutritionists, and healthcare providers are essential to harness the power of genetic information for improving metabolic health. By unraveling the genetic basis of metabolic responses to diet, this field holds the potential to revolutionize how we approach dietary recommendations and preventive healthcare practices.

Bioetics Issues of Artificial Placenta and Artificial Womb Technology

Abstract

The worldwide infertility crisis and the increase in mortality and morbidity among infants, due to preterm births and associated complications, have stimulated research into artificial placenta (AP) and artificial womb (AW) technology as novel solutions. These technologies mimic the natural environment provided in the mother's womb, using chambers that ensure the supply of nutrients to the fetus and disposal of waste substances through an appropriate mechanism. This review aims to highlight the background of AP and AW technologies, revisit their historical development and proposed applications, and discuss challenges and bioethical and moral issues. Further research is required to investigate any negative effects of these new technologies, and ethical concerns pertaining to the structure and operation of this newly developed technology must be addressed and resolved prior to its introduction to the public sphere.

Nutrigenomics: SNPs correlated to Food Preferences and Susceptibilities

Background

Nutrigenomics explores the intricate interplay between single nucleotide polymorphisms (SNPs), food preferences, and susceptibilities.

Methods

This study delves into the influence of SNPs on food sensitivities, allergies, tyramine intolerance, and taste preferences. Genetic factors intricately shape physiological reactions to dietary elements, with polymorphisms contributing to diverse sensitivities and immune responses.

Results

Tyramine intolerance, arising from metabolic inefficiencies, unveils genetic markers exerting influence on enzyme function. SNPs transcend genetic diversity by exerting substantial impact on food sensitivities/allergies, with specific variants correlating to heightened susceptibilities. Genes accountable for digesting food components play pivotal roles. Given the rising prevalence of food sensitivities/allergies, understanding genetic foundations becomes paramount. In the realm of taste and food preferences, SNPs sculpt perception and choice, yielding variances in taste perception and preferences for sweetness, bitterness, and umami. This genetic medley extends its reach to encompass wider health implications.

Conclusions

In this review article, we have focused on how polymorphisms wield significant sway over physiological responses, sensitivities, and dietary inclinations. Unraveling these intricate relationships illuminates the path to personalized nutrition, potentially revolutionizing tailored recommendations and interventions.

Omics sciences and precision medicine in lung cancer

Abstract

Lung cancer is a complex disease, with a wide range of genetic alterations and clinical presentations. Understanding the natural and clinical history of the disease is crucial for developing effective diagnostic and treatment strategies. Omics approaches, such as genomics, transcriptomics, proteomics, and metabolomics, have emerged as powerful tools for understanding the molecular mechanisms underlying lung cancer and for identifying novel biomarkers and therapeutic targets. These approaches enable researchers to examine the entire genome, transcriptome, proteome, or metabolome of a cell or tissue, providing a comprehensive view of the biological processes involved in lung cancer development and progression. Targeted therapies that address specific genetic mutations and pathways hold promise for improving the diagnosis and treatment of this disease.

Omics sciences and precision medicine in sarcoma

Background

Sarcomas are a relatively rare but diverse group of cancers that typically develop in the mesenchymal cells of bones and soft tissues. Occurring in more than 70 subtypes, sarcomas have broad histological presentations, posing significant challenges of prognosis and treatment. Modern multi-omics studies, which include genomics, proteomics, metabolomics, and micro-biomics, are vital to understand the underlying mechanisms of sarcoma development and progression, identify molecular biomarkers for early detection, develop personalized treatment plans, and discover drug resistance mechanisms in sarcomas to upsurge the survival rate.

Aim

This study aims to highlight the genetic risk factors responsible for sarcoma-genesis, and to present a comprehensive review of multi-omics studies about sarcoma.

Methods

Extensive literature research was undertaken using reliable and authentic medical journals, e-books, and online cancer research databases. Mendelian inheritance in man database (OMIM) was explored to study particular genes and their loci that are responsible to cause various sarcomas.

Result

This in-depth research led to the finding out that omics studies provide a more comprehensive understanding of underlying molecular mechanisms of sarcomas. Through genomics, we can reveal genetic alterations that predispose to sarcoma, like mutation in TP53, NF1, and so on. Pharmacogenomics enable us to find molecular targets for specific drugs. Whereas, proteomic and metabolomic studies provide insights into the biological pathways involved in sarcoma development and progression.

Conclusion

Future advancements in omics sciences for sarcoma are on the cutting-edge of defining precision treatment plans and improved resilience of sarcoma patients.

Characterization of somatic mutations in the pathogenesis of lipedema

Background

Lipedema, a complex and enigmatic adipose tissue disorder, remains poorly understood despite its significant impact on the patients' quality of life. Genetic investigations have uncovered potential contributors to its pathogenesis, including somatic mutations, which are nonheritable genetic alterations that can play a pivotal role in the development of this disease.

Aim

This review aims to elucidate the role of somatic mutations in the etiology of lipedema by examining their implications in adipose tissue biology, inflammation, and metabolic dysfunction.

Results

Studies focusing on leukocyte clones, genetic alterations like TET2 and DNMT3A, and the intricate interplay between adipose tissue and other organs have shed light on the underlying mechanisms driving lipedema. From the study of the scientific literature, mutations to genes correlated to three main pathways could be involved in the somatic development of lipedema: genes related to mitochondrial activity, genes related to localized disorders of subcutaneous adipose tissue, and genes of leukocyte clones.

Conclusions

The insights gained from these diverse studies converge to highlight the complex genetic underpinnings of lipedema and offer potential avenues for therapeutic interventions targeting somatic mutations to alleviate the burden of this condition on affected individuals.

Human Cloning: Biology, Ethics, and Social Implications

Abstract

This scholarly article delves into the multifaceted domains of human cloning, encompassing its biological underpinnings, ethical dimensions, and broader societal implications. The exposition commences with a succinct historical and contextual overview of human cloning, segueing into an in-depth exploration of its biological intri-cacies. Central to this biological scrutiny is a comprehensive analysis of somatic cell nuclear transfer (SCNT) and its assorted iterations. The accomplishments and discoveries in cloning technology, such as successful animal cloning operations and advances in the efficiency and viability of cloned embryos, are reviewed. Future improvements, such as reprogramming procedures and gene editing technology, are also discussed. The discourse extends to ethical quandaries intrinsic to human cloning, entailing an extensive contemplation of values such as human dignity, autonomy, and safety. Furthermore, the ramifications of human cloning on a societal plane are subjected to scrutiny, with a dedicated emphasis on ramifications encompassing personal identity, kinship connections, and the fundamental notion of maternity. Culminating the analysis is a reiteration of the imperative to develop and govern human cloning technology judiciously and conscientiously. Finally, it discusses several ethical and practical issues, such as safety concerns, the possibility of exploitation, and the erosion of human dignity, and emphasizes the significance of carefully considering these issues.

Omics sciences and precision medicine in thyroid cancer

Background

Thyroid cancer, a heterogeneous disease originating from the thyroid gland, stands as the predominant endocrine malignan-cy worldwide. Despite advances in diagnosis and treatment, some patients still experience recurrence and mortality, which highlights the need for more personalized approaches to treatment. Omics sciences, encompassing genomics, transcriptomics, proteomics, and metabolomics, offer a high-throughput and impartial methodology for investigating the molecular signatures of thyroid cancer.

Methods

In the course of this review, we have adopted a focu-sed research strategy, meticulously selecting the most pertinent and emblematic articles related to the topic. Our methodology included a systematic examination of the scientific literature to guarantee a thorough and precise synthesis of the existing sources.

Results

These techniques enable the identification of molecular markers that can aid in diagnosis, prognosis, and treatment selection. As an illustration, through genomics studies, numerous genetic alterations commonly discovered in thyroid cancer have been identified, such as mutations in the BRAF and RAS genes. Through transcriptomics studies, distinctively expressed genes in thyroid cancer have been uncovered, playing roles in diverse biological processes, including cell proliferation, invasion, and metastasis. These genes can serve as potential targets for novel therapies. Proteomics studies have unveiled differentially expressed proteins intricately involved in thyroid cancer pathogenesis, presenting promising biomarkers for early detection and disease progression monitoring. Metabolomics studies have identified alterations in metabolic pathways linked to thyroid cancer, offering promising avenues for potential therapeutic targets.

Conclusions

Precision medicine in thyroid cancer involves the integration of omics sciences with clinical data to develop personalized treatment plans for patients. Employing targeted therapies guided by molecular markers has exhibited promising outcomes in enhancing the prognosis of thyroid cancer patients. Notably, those with advanced hyroid cancer carrying BRAF mutations have displayed substantial responses to specific targeted therapies, such as vemurafenib and dabrafenib.

In Memory of Professor Derek Pheby

Abstract

Professor Derek Pheby's passing in November 2022 marked a profound loss for the scientific community. Professor Derek Pheby, a stalwart figure in the fields of autoimmune diseases and bioethics, was known for his dedication to scientific research and patients' support, particularly for those affected by paraneoplastic autoimmune syndromes. Professor Pheby made significant contributions to research, especially about Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). His leadership of the ME Biobank and scientific coordination of EUROMENE demonstrated his commitment to pushing boundaries and fostering international collaborations. Professor Pheby's scientific work addressed various aspects of ME/CFS, from physician education to patient needs, the development of a post-mortem tissue bank, and effective treatments. Beyond his medical career, Professor Pheby was a crucial member of the Independent Ethics Committee of MAGI, he was a poet, humanitarian, and advocate for child protection. His generosity and boundless spirit left an enduring legacy, fostering innovative research in the pursuit of combating autoimmune diseases.

Reduction of nitrosamines in cigarette smoke vapors through a filter functionalized with polyphenols from olive tree

Objective

In our study, we present the development of a novel cigarette filter enriched with polyphenols, with a particular focus on hydroxytyrosol extracted from olive sources. Our objective was to trap the presence of carcinogens in cigarette smoke by chemically modifying the filter surface.

Materials and methods

To evaluate the filtration efficiency of the newly developed filter, we employed an automated Stain Pattern technique, enabling non-intrusive measurement of behavioral vent blocking. The surface modification of cigarette filters was meticulously carried out to target the reduction of nitrosamines formed during combustion.

Results

Our extensive investigation underscores the potential of functionalizing cigarette filters using olive polyphenols, in particular hydroxytyrosol to mitigate the formation of harmful compounds, particularly nitrosamines, during smoking. Functionalized filters exhibited remarkable filtering efficiency, as evidenced by a capture factor (f=2.9×103) for two layers.

Conclusions

This innovative approach has the capacity to revolutionize the utilization of filters in commercial cigarettes, significantly reducing consumers' exposure to toxic chemicals. Our research demonstrates that hydroxytyrosol-functionalized cigarette filters can effectively remove noxious substances like nitrosamines, offering a promising avenue for enhancing public health. Further in-depth research is essential to assess the protective impact of hydroxytyrosol-functionalized filters cigarettes, ensuring their potential to safeguard consumers' health effectively.

Nutrigenomics: SNPs correlated to vitamins' deficiencies

Abstract

Nutrients can influence the physiological processes in the body by interacting with molecular systems. Including nutrigenetics and nutrigenomics, nutritional genomics focuses on how bio-active food components interact with the genome. The purpose of this study is to clarify how nutrigenomics and vitamin dietary deficits relate to one another. Food tolerances among human sub-populations are known to vary due to genetic variation, which may also affect dietary needs. This raises the prospect of tailoring a person's nutritional intake for optimum health and illness prevention, based on their unique genome. To better understand the interplay between genes and nutrients and to plan tailored weight loss, nutrigenetic testing may soon become a key approach.

Olive tree polyphenols as effective and sustainable grain preservatives

Abstract

Whole grains play a crucial role in the human diet. Despite being cultivated in distinct regions, they are shipped everywhere, therefore making biosafety and security essential throughout the grain industry, from harvest to distribution. Phytopathogens, which have an impact on crop yield, induce grain spoiling and reduce grain quality in a number of ways, providing a constant danger to crop storage and distribution. Chemical control approaches, such as the use of pesticides and fungicides, are detrimental to the environment and hazardous to human health. The development of alternative, environmentally friendly, and generally acceptable solutions to ensure increased grain yield, biosafety, and quality during storage is crucial in order to guarantee sufficient food and feed supplies. As a means of self-defense against microbial infection and spoilage, plant matrices feature antimicrobial natural chemicals, which have led to their widespread usage as food preservatives in recent decades. Olive tree extracts, known for their high polyphenol content, have been widely used in the food preservation industry with great success, and are highly welcomed by people all over the world. In addition to their well-known health advantages, polyphenols are a valuable plant secondary metabolite because of their great antibacterial capabilities as natural preservatives. This article discusses the promising usage of polyphenols from olive trees as a natural alternative preservative, while also highlighting the future of olive eaves in the food industry.

Nutrigenomics: SNPs correlated to detoxification, antioxidant capacity and longevity

Abstract

Nutritional genomics, also known as nutrigenomics, is the study of how a person's diet and genes interact with each other. The field of nutrigenomics aims to explain how common nutrients, food additives and preservatives can change the body's genetic balance towards either health or sickness. This study reviews the effects of SNPs on detoxification, antioxidant capacity, and longevity. SNPs are mutations that only change one nucleotide at a specific site in the DNA. Specific SNPs have been associated to a variety of biological processes, including detoxification, antioxidant capacity, and longevity. This article mainly focuses on the following genes: SOD2, AS3MT, CYP1A2, and ADO-RA2A (detoxification); LEPR, TCF7L2, KCNJ11, AMY1, and UCP3 (antioxidant capacity); FOXO3 and BPIFB4 (longevity). This review underlines that many genes-among which FOXO3, TCF7L2, LEPR, CYP1A2, ADORA2A, and SOD2-have a unique effect on a person's health, susceptibility to disease, and general well-being. Due to their important roles in numerous biological processes and their implications for health, these genes have undergone intensive research. Examining the SNPs in these genes can provide insight into how genetic variants affect individuals' responses to their environment, their likelihood of developing certain diseases, and their general state of health.

Omics sciences and precision medicine in melanoma

Background

This article provides an overview of the application of omics sciences in melanoma research. The name omics sciences refers to the large-scale analysis of biological molecules like DNA, RNA, proteins, and metabolites.

Methods

In the course of this review, we have adopted a focu-sed research strategy, meticulously selecting the most pertinent and emblematic articles related to the topic. Our methodology included a systematic examination of the scientific literature to guarantee a thorough and precise synthesis of the existing sources.

Results

With the advent of high-throughput technologies, omics have become an essential tool for understanding the complexity of melanoma. In this article, we discuss the different omics approaches used in melanoma research, including genomics, transcriptomics, proteomics, and metabolomics. We also highlight the major findings and insights gained from these studies, including the identification of new therapeutic targets and the development of biomarkers for diagnosis and prognosis. Finally, we discuss the challenges and future directions in omics-based melanoma research, including the integration of multiple omics data and the development of personalized medicine approaches.

Conclusions

Overall, this article emphasizes the importance of omics science in advancing our understanding of melanoma and its potential for improving patient outcomes.

Targeting Mast Cells: Sodium Cromoglycate as a Possible Treatment of Lipedema

Background

Mast cells are immune cells that mediate hypersensi-tivity and allergic reactions in the body, secreting histamine and other inflammatory molecules. They have been associated with different inflammatory conditions such as obesity and other adipose tissue di-sorders. Lipedema is a chronic disease characterized by an abnormal accumulation of adipose tissue on the legs and arms, pain, and other symptoms. Mast cells may play a role in the pathology of lipedema.

Objective

Pilot study to determine levels of histamine and its metabolites in lipedema subcutaneous adipose tissue (SAT) biopsy samples, and to test sodium cromoglycate for the treatment of mast cells in women with lipedema.

Methods

Biopsies from lipedema and control SAT were collected and analyzed histologically for the presence of mast cells. Mass spec-trometry was used to measure the levels of histamine, a key marker of mast cells, and its metabolites in SAT in women with lipedema and controls, and after a group of women with lipedema were administered oral and topical doses of sodium cromoglycate for two weeks.

Results

Histological examination of biopsies from lipedema patients confirmed the presence of mast cells. Metabolomic analysis revealed high levels of histamine and its metabolites in samples from women with lipedema compared to controls. Following a two-week treatment period, lipedema tissue samples exhibited reduced levels of histamine, suggesting a reduction of mast cell activity.

Conclusion

Sodium cromoglycate has the ability to stabilize mast cells and reduce histamine levels in lipedema patients, which could be useful in lowering the symptoms of lipedema.

Effect of a dietary supplement on the reduction of lymphedema-progression in mouse tail-cut model

OBJECTIVE

The aim of our study was to evaluate in vivo, in a mouse tail model of lymphedema, the effects of a dietary supplement, Garlive®, based on hydroxytyrosol from olive leaves, spermidine from rice seeds, hesperidin from citrus fruits and vitamin A. Hydroxytyrosol has anti-inflammatory, antioxidant and antimicrobial activities and inhibits leukotriene B4 generation; spermidine is able to inhibit the production of pro-inflammatory cytokines and mediators; hesperidin inhibits the secretion of pro-inflammatory cytokines: IFN-γ, IL-2, IL-4, IL-10; vitamin A deficiency was shown to induce inflammation and aggravate existing inflammatory states, whereas supplementation with vitamin A could ameliorate inflammation.

MATERIALS AND METHODS

The active compounds were included in tablets: 250 mg of olive leaf extract titrated in 10% hydroxytyrosol, 200 mg of citrus fruits extract titrated in 60% hesperidin, 10 mg of rice (Oryza sativa) seeds extract titrated in 1% spermidine and 0.8 mg of vitamin A. Mice of an inbred group were randomly selected and divided in the control group and drug-treated group. The wound necessary for lymphedema generation was made on the tail of each mice 1 cm below the base of the trunk.

RESULTS

After surgical intervention, there was a gradual increase in the circumference of both ends of the wound. The control group showed higher increase of tail volume than the drug-treated group. The differences in tail swelling between the control group and the drug-treated group were significantly different. The peak of swelling was anticipated to the 6th day in the drug-treated group, whereas in the control group the peak was reached later on.

CONCLUSIONS

The tested drug prevented the induction of swelling from day 5th of wound creation and decreased the duration of swelling, favoring the wound healing.

Modelling the temperature evolution of bone under high intensity focused ultrasound

Magnetic resonance-guided high intensity focused ultrasound (MR-HIFU) has been clinically shown to be effective for palliative pain management in patients suffering from skeletal metastasis. The underlying mechanism is supposed to be periosteal denervation caused by ablative temperatures reached through ultrasound heating of the cortex. The challenge is exact temperature control during sonication as MR-based thermometry approaches for bone tissue are currently not available. Thus, in contrast to the MR-HIFU ablation of soft tissue, a thermometry feedback to the HIFU is lacking, and the treatment of bone metastasis is entirely based on temperature information acquired in the soft tissue adjacent to the bone surface. However, heating of the adjacent tissue depends on the exact sonication protocol and requires extensive modelling to estimate the actual temperature of the cortex. Here we develop a computational model to calculate the spatial temperature evolution in bone and the adjacent tissue during sonication. First, a ray-tracing technique is used to compute the heat production in each spatial point serving as a source term for the second part, where the actual temperature is calculated as a function of space and time by solving the Pennes bio-heat equation. Importantly, our model includes shear waves that arise at the bone interface as well as all geometrical considerations of transducer and bone geometry. The model was compared with a theoretical approach based on the far field approximation and an MR-HIFU experiment using a bone phantom. Furthermore, we investigated the contribution of shear waves to the heat production and resulting temperatures in bone. The temperature evolution predicted by our model was in accordance with the far field approximation and agreed well with the experimental data obtained in phantoms. Our model allows the simulation of the HIFU treatments of bone metastasis in patients and can be extended to a planning tool prior to MR-HIFU treatments.

Activation of plant foliar oxidases by insect feeding reduces nutritive quality of foliage for noctuid herbivores

The foliage and fruit of the tomato plantLycopersicon esculentum contains polyphenol oxidases (PPO) and peroxidases (POD) that are compartmentally separated from orthodihydroxyphenolic substrates in situ. However, when leaf tissue is damaged by insect feeding, the enzyme and phenolic substrates come in contact, resulting in the rapid oxidation of phenolics to orthoquinones. When the tomato fruitwormHeliothis zea or the beet army-wormSpodoptera exigua feed on tomato foliage, a substantial amount of the ingested chlorogenic acid is oxidized to chlorogenoquinone by PPO in the insect gut. Additionally, the digestive enzymes of the fruitworm have the potential to further activate foliar oxidase activity in the gut. Chlorogenoquinone is a highly reactive electrophilic molecule that readily binds cova-lently to nucleophilic groups of amino acids and proteins. In particular, the -SH and -NH2 groups of amino acids are susceptible to binding or alkylation. In experiments with tomato foliage, the relative growth rate of the fruitworm was negatively correlated with PPO activity. As the tomato plant matures, foliar PPO activity may increase nearly 10-fold while the growth rate of the fruitworm is severely depressed. In tomato fruit, the levels of PPO are highest in small immature fruit but are essentially negligible in mature fruit. The growth rate of larvae on fruit was also negatively correlated with PPO activity, with the fastest larval growth rate occurring when larvae fed on mature fruit. The reduction in larval growth is proposed to result from the alkylation of amino acids/protein byo-quinones, and the subsequent reduction in the nutritive quality of foliage. This alkylation reduces the digestibility of dietary protein and the bioavailability of amino acids. We believe that this mechanism of digestibility reduction may be extrapolatable to other plant-insect systems because of the ubiquitous cooccurrence of PPO and phenolic substrates among vascular plant species.

Observation of two-neutrino double-beta decay in 136Xe with the EXO-200 detector

We report the observation of two-neutrino double-beta decay in (136)Xe with T(1/2) = 2.11 ± 0.04(stat) ± 0.21(syst) × 10(21) yr. This second-order process, predicted by the standard model, has been observed for several nuclei but not for (136)Xe. The observed decay rate provides new input to matrix element calculations and to the search for the more interesting neutrinoless double-beta decay, the most sensitive probe for the existence of Majorana particles and the measurement of the neutrino mass scale.

A magnetically driven piston pump for ultra-clean applications

A magnetically driven piston pump for xenon gas recirculation is presented. The pump is designed to satisfy extreme purity and containment requirements, as is appropriate for the recirculation of isotopically enriched xenon through the purification system and large liquid xenon time projection chamber of EXO-200. The pump, using sprung polymer gaskets, is capable of pumping more than 16 standard liters per minute of xenon gas with 750 Torr differential pressure.