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1.
Eur J Cancer ; 206: 114128, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38805957

ABSTRACT

Duodenal adenocarcinoma is a rare digestive cancer, often diagnosed at a late stage and harbours a poor prognosis. The arrival of immunotherapy has changed the prognosis of many neoplasia, including digestive adenocarcinomas with MSI-H status. Hereby, we describe three cases of MSI-H locally advanced duodenal adenocarcinoma who received neoadjuvant treatment with a PD1 inhibitor, pembrolizumab. A partial metabolic and endoscopic response was observed in all patients after 2 cycles. Duodenopancreatectomy was performed at the end of treatment (4-6 cycles), and anatomopathological analysis demonstrated pathological complete response in all patients. Our case series paves the way for prospectively exploring neoadjuvant immunotherapy in duodenal MSI-H adenocarcinoma and raises the question of organ sparing surgery in case of complete clinical response as observed in gastric and colo-rectal adenocarcinomas.


Subject(s)
Adenocarcinoma , Antibodies, Monoclonal, Humanized , Duodenal Neoplasms , Microsatellite Instability , Neoadjuvant Therapy , Humans , Adenocarcinoma/genetics , Adenocarcinoma/therapy , Adenocarcinoma/pathology , Duodenal Neoplasms/genetics , Duodenal Neoplasms/pathology , Duodenal Neoplasms/therapy , Neoadjuvant Therapy/methods , Male , Aged , Middle Aged , Female , Antibodies, Monoclonal, Humanized/therapeutic use , Immunotherapy/methods , Immune Checkpoint Inhibitors/therapeutic use , Antineoplastic Agents, Immunological/therapeutic use , Treatment Outcome
2.
Front Plant Sci ; 14: 1012529, 2023.
Article in English | MEDLINE | ID: mdl-36743509

ABSTRACT

In the past decade, the potential of positioning LED lamps in between the canopy (intra-canopy) to enhance crop growth and yield has been explored in greenhouse cultivation. Changes in spatial heterogeneity of light absorption that come with the introduction of intra-canopy lighting have not been thoroughly explored. We calibrated and validated an existing functional structural plant model (FSPM), which combines plant morphology with a ray tracing model to estimate light absorption at leaflet level. This FSPM was used to visualize the light environment in a tomato crop illuminated with intra-canopy lighting, top lighting or a combination of both. Model validation of light absorption of individual leaves showed a good fit (R2 = 0.93) between measured and modelled light absorption of the canopy. Canopy light distribution was then quantified and visualized in three voxel directions by means of average absorbed photosynthetic photon flux density (PPFD) and coefficient of variation (CV) within that voxel. Simulations showed that the variation coefficient within horizontal direction was higher for intra-canopy lighting than top lighting (CV=48% versus CV= 43%), while the combination of intra-canopy lighting and top lighting yielded the lowest CV (37%). Combined intra-canopy and top lighting (50/50%) had in all directions a more uniform light absorption than intra-canopy or top lighting alone. The variation was minimal when the ratio of PPFD from intra-canopy to top lighting was about 1, and increased when this ratio increased or decreased. Intra-canopy lighting resulted in 8% higher total light absorption than top lighting, while combining 50% intra-canopy lighting with 50% top lighting, increased light absorption by 4%. Variation in light distribution was further reduced when the intra-canopy LEDs were distributed over strings at four instead of two heights. When positioning LED lamps to illuminate a canopy both total light absorption and light distribution have to be considered.

3.
Trends Plant Sci ; 26(5): 496-508, 2021 05.
Article in English | MEDLINE | ID: mdl-33358304

ABSTRACT

Light spectral composition influences plant growth and metabolism, and has important consequences for interactions with plant-feeding arthropods and their natural enemies. In greenhouse horticulture, light spectral composition can be precisely manipulated by light-emitting diodes (LEDs), and LEDs are already used to optimize crop production and quality. However, because light quality also modulates plant secondary metabolism and defense, it is important to understand the underlying mechanisms in the context of the growth-defense trade-off. We review the effects of the spectral composition of supplemental light currently used, or potentially used, in greenhouse horticulture on the mechanisms underlying plant growth and defense. This information is important for exploring opportunities to optimize crop performance and pest management, and thus for developing resilient crop-production systems.


Subject(s)
Lighting , Plant Development , Crop Production , Light , Plants
4.
Nat Food ; 2(12): 944-956, 2021 12.
Article in English | MEDLINE | ID: mdl-37118238

ABSTRACT

Vertical farming can produce food in a climate-resilient manner, potentially emitting zero pesticides and fertilizers, and with lower land and water use than conventional agriculture. Vertical farming systems (VFS) can meet daily consumer demands for nutritious fresh products, forming a part of resilient food systems-particularly in and around densely populated areas. VFS currently produce a limited range of crops including fruits, vegetables and herbs, but successful implementation of vertical farming as part of mainstream agriculture will require improvements in profitability, energy efficiency, public policy and consumer acceptance. Here we discuss VFS as multi-layer indoor crop cultivation systems, exploring state-of-the-art vertical farming and future challenges in the fields of plant growth, product quality, automation, robotics, system control and environmental sustainability and how research and development, socio-economic and policy-related institutions must work together to ensure successful upscaling of VFS to future food systems.

5.
PLoS One ; 15(5): e0233210, 2020.
Article in English | MEDLINE | ID: mdl-32469897

ABSTRACT

Organ temperature and variation therein plays a key role in plant functioning and its responses to e.g. climate change. There is a strong feedback between organ, especially leaf, temperature and the climate within the canopy (canopy climate), which in turn interacts with the climate outside the canopy (ambient climate). For greenhouses, the determinants of this interplay and how they drive differences between canopy and ambient climate are poorly understood. Yet, as many experiments on both regular greenhouse crops and field crops are done in greenhouses, this is crucial to know. Therefore, we designed an experiment to quantify the differences between ambient and canopy climate and leaf temperature. A path analysis was performed to quantify the interactions between components of the greenhouse canopy-climate system. We found that with high radiation the canopy climate can be up to 5°C cooler than the ambient climate, while for cloudy days this was only 2°C. Canopy relative humidity (RH) was up to 25% higher compared to ambient RH. We showed that radiation is very important for these climate differences, but that this effect could be partly counteracted by turning off supplementary light (i.e. due to its indirect effects e.g. changing light distribution). Leaf temperature was substantially different, both higher and lower, from the canopy air temperature. This difference was determined by leaf area index (LAI), temperature of the heating pipe and the use of supplementary light, which all strongly influence radiation, either shortwave or thermal radiation. The difference between leaf and ambient air temperature could be decreased by decreasing the LAI or increasing the temperature of the heating pipe.


Subject(s)
Climate Change , Models, Biological , Plant Leaves/growth & development , Seasons , Trees/growth & development
6.
Rev Med Liege ; 74(9): 461-464, 2019 Sep.
Article in French | MEDLINE | ID: mdl-31486315

ABSTRACT

The treatment of spinal muscular atrophy (SMA) has considerably changed over the last 3 years. Several approaches that aim to increase the deficient SMN protein have demonstrated an efficacy that is inversely correlated with disease duration. In this context, newborn screening (NBS) is increasingly considered as the next step in several countries or regions. In 2018, we initiated a pilot study for NBS of SMA in French- and German-speaking Belgium. We aim to evaluate the feasibility, the efficacy, and the cost-effectiveness of such a program. Initially covering the region of Liege, the program was recently extended to the whole Southern Belgium and currently covers about 55.000 newborns per year. On June 1st 2019, 35.000 newborns had been screened and 5 affected babies were identified and referred to neuromuscular centers for early treatment. A full evaluation of the program will take place after three years to consider the inclusion of SMA screening in the publically-funded NBS program in Southern Belgium.


La prise en charge de l'amyotrophie spinale antérieure (SMA) a considérablement évolué au cours des trois dernières années. Les différents essais visant à augmenter la production de la protéine SMN déficitaire dans la SMA ont systématiquement montré une efficacité inversement proportionnelle à la durée de la maladie. Dès lors, l'implémentation d'un programme de dépistage néonatal s'est rapidement imposée comme une évidence médico-économique dans de nombreux pays. Dans ce contexte, nous avons initié un programme de dépistage néonatal pour la SMA en Belgique francophone et germanophone. En 2018, une étude pilote de trois ans visant à évaluer la faisabilité, l'efficacité et la rentabilité du screening a été initiée au sein du centre de dépistage de Liège. L'étude a récemment été étendue à l'ensemble de la Fédération Wallonie-Bruxelles (FWB) pour couvrir environ 55.000 naissances annuelles. Au 1er juin 2019, 35.000 bébés ont été dépistés et cinq nouveau-nés atteints de SMA ont été identifiés. Tous ont été immédiatement référés pour assurer leur prise en charge dans un centre de référence pour les maladies neuromusculaires. Une évaluation complète du programme aura lieu à l'issue de la phase pilote, afin d'envisager que la SMA soit reconnue comme maladie officielle du programme de dépistage néonatal en FWB.


Subject(s)
Muscular Atrophy, Spinal , Belgium/epidemiology , Humans , Infant , Infant, Newborn , Muscular Atrophy, Spinal/diagnosis , Muscular Atrophy, Spinal/epidemiology , Neonatal Screening , Pilot Projects
7.
Dalton Trans ; 46(44): 15287-15300, 2017 Nov 14.
Article in English | MEDLINE | ID: mdl-29068442

ABSTRACT

The photophysical, photochemical and electrochemical properties of two newly synthesized ruthenium complexes, [Ru(phen)2(TAPHAT)]2+ and [Ru(phen)2(TAPHAT)Ru(phen)2]4+, are reported. We have developed a novel synthetic methodology that involves the metal-free oxidative coupling of diamino compounds to form a desired "pyrazine-type" core. This methodology is employed both on the free diamino ligand as well as on the different ruthenium complexes, therefore illustrating the applicability of this reaction. The TAPHAT ligand, which possesses 7 aromatic rings and 10 nitrogen atoms for 20 carbon atoms, gives rise to ruthenium complexes that can undergo up to three consecutive reductions centered on said ligand, a critical parameter for electron storage applications. A temperature-dependent study has confirmed the presence of a 4th MLCT state. Excited-state quenching in the presence of guanine or hydroquinone allows to foresee biomedical applications.

8.
Ann Bot ; 114(1): 145-56, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24782436

ABSTRACT

BACKGROUND AND AIMS: Plants use diffuse light more efficiently than direct light. However, experimental comparisons between diffuse and direct light have been obscured by co-occurring differences in environmental conditions (e.g. light intensity). This study aims to analyse the factors that contribute to an increase in crop photosynthesis in diffuse light and to quantify their relative contribution under different levels of diffuseness at similar light intensities. The hypothesis is that the enhancement of crop photosynthesis in diffuse light results not only from the direct effects of more uniform vertical and horizontal light distribution in the crop canopy, but also from crop physiological and morphological acclimation. METHODS: Tomato (Solanum lycopersicum) crops were grown in three greenhouse compartments that were covered by glass with different degrees of light diffuseness (0, 45 and 71 % of the direct light being converted into diffuse light) while maintaining similar light transmission. Measurements of horizontal and vertical photosynthetic photon flux density (PPFD) distribution in the crop, leaf photosynthesis light response curves and leaf area index (LAI) were used to quantify each factor's contribution to an increase in crop photosynthesis in diffuse light. In addition, leaf temperature, photoinhibition, and leaf biochemical and anatomical properties were studied. KEY RESULTS: The highest degree of light diffuseness (71 %) increased the calculated crop photosynthesis by 7·2 %. This effect was mainly attributed to a more uniform horizontal (33 % of the total effect) and vertical PPFD distribution (21 %) in the crop. In addition, plants acclimated to the high level of diffuseness by gaining a higher photosynthetic capacity of leaves in the middle of the crop and a higher LAI, which contributed 23 and 13 %, respectively, to the total increase in crop photosynthesis in diffuse light. Moreover, diffuse light resulted in lower leaf temperatures and less photoinhibition at the top of the canopy when global irradiance was high. CONCLUSIONS: Diffuse light enhanced crop photosynthesis. A more uniform horizontal PPFD distribution played the most important role in this enhancement, and a more uniform vertical PPFD distribution and higher leaf photosynthetic capacity contributed more to the enhancement of crop photosynthesis than did higher values of LAI.


Subject(s)
Acclimatization , Photosynthesis/drug effects , Solanum lycopersicum/radiation effects , Chlorophyll/physiology , Chlorophyll/radiation effects , Crops, Agricultural , Fruit/physiology , Fruit/radiation effects , Solanum lycopersicum/physiology , Plant Leaves/physiology , Plant Leaves/radiation effects , Sunlight , Temperature
10.
J Exp Bot ; 65(1): 11-22, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24227339

ABSTRACT

Mapping studies using populations with introgressed marker-defined genomic regions are continuously increasing knowledge about quantitative trait loci (QTL) that correlate with variation in important crop traits. This knowledge is useful for plant breeding, although combining desired traits in one genotype might be complicated by the mode of inheritance and co-localization of QTL with antagonistic effects, and by physiological trade-offs, and feed-back or feed-forward mechanisms. Therefore, integrating advances at the genetic level with insight into influences of environment and crop management on crop performance remains difficult. Whereas mapping studies can pinpoint correlations between QTL and phenotypic traits for specific conditions, ignoring or overlooking the importance of environment or crop management can jeopardize the relevance of such assessments. Here, we focus on fruit load (a measure determining competition among fruits on one plant) and its strong modulation of QTL effects on fruit size and composition. Following an integral approach, we show which fruit traits are affected by fruit load, to which underlying processes these traits can be linked, and which processes at lower and higher integration levels are affected by fruit load (and subsequently influence fruit traits). This opinion paper (i) argues that a mechanistic framework to interpret interactions between fruit load and QTL effects is needed, (ii) pleads for consideration of the context of agronomic management when detecting QTL, (iii) makes a case for incorporating interacting factors in the experimental set-up of QTL mapping studies, and (iv) provides recommendations to improve efficiency in QTL detection and use, with particular focus on model-based marker-assisted breeding.


Subject(s)
Crops, Agricultural/genetics , Fruit/physiology , Gene Expression Regulation, Plant , Gene-Environment Interaction , Quantitative Trait Loci/genetics , Breeding , Chromosome Mapping , Crops, Agricultural/physiology , Fruit/genetics , Genotype , Models, Genetic , Phenotype
11.
Gene Ther ; 20(4): 435-43, 2013 Apr.
Article in English | MEDLINE | ID: mdl-22809997

ABSTRACT

High-risk Human Papillomaviruses (HPV) has been found to be associated with carcinomas of the cervix, penis, vulva/vagina, anus, mouth and oro-pharynx. As the main tumorigenic effects of the HPV have been attributed to the expression of E6 and E7 genes, different gene therapy approaches have been directed to block their expression such as antisense oligonucleotides (ASO), ribozymes and small interfering RNAs. In order to develop a gene-specific therapy for HPV-related cancers, we investigated a potential therapeutic strategy of gene silencing activated under illumination. Our aim according to this antisense therapy consisted in regulating the HPV16 E6 oncogene by using an E6-ASO derivatized with a polyazaaromatic ruthenium (Ru(II)) complex (E6-Ru-ASO) able, under visible illumination, to crosslink irreversibly the targeted sequence. We examined the effects of E6-Ru-ASO on the expression of E6 and on the cell growth of cervical cancer cells. We demonstrated using HPV16(+) SiHa cervical cancer cells that E6-Ru-ASO induces after illumination, a reactivation of p53, the most important target of E6, as well as the inhibition of cell proliferation with a selective repression of E6 at the protein level. These results suggest that E6-Ru ASOs, activated under illumination and specifically targeting E6, are capable of inhibiting HPV16(+) cervical cancer cell proliferation.


Subject(s)
Cell Proliferation/drug effects , Light , Oligonucleotides/genetics , Oncogene Proteins, Viral/genetics , Repressor Proteins/genetics , Ruthenium Compounds/radiation effects , Tumor Suppressor Protein p53/metabolism , Uterine Cervical Neoplasms/therapy , Cell Line, Tumor , Cross-Linking Reagents/chemistry , Female , Gene Silencing , Genes, p53 , Genetic Therapy , Humans , Oligonucleotides/chemistry , Oncogene Proteins, Viral/metabolism , Repressor Proteins/metabolism , Ruthenium Compounds/chemistry , Uterine Cervical Neoplasms/virology
12.
Ann Bot ; 108(6): 1065-73, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21865217

ABSTRACT

BACKGROUND AND AIMS: Manipulation of plant structure can strongly affect light distribution in the canopy and photosynthesis. The aim of this paper is to find a plant ideotype for optimization of light absorption and canopy photosynthesis. Using a static functional structural plant model (FSPM), a range of different plant architectural characteristics was tested for two different seasons in order to find the optimal architecture with respect to light absorption and photosynthesis. METHODS: Simulations were performed with an FSPM of a greenhouse-grown tomato crop. Sensitivity analyses were carried out for leaf elevation angle, leaf phyllotaxis, leaflet angle, leaf shape, leaflet arrangement and internode length. From the results of this analysis two possible ideotypes were proposed. Four different vertical light distributions were also tested, while light absorption cumulated over the whole canopy was kept the same. KEY RESULTS: Photosynthesis was augmented by 6 % in winter and reduced by 7 % in summer, when light absorption in the top part of the canopy was increased by 25 %, while not changing light absorption of the canopy as a whole. The measured plant structure was already optimal with respect to leaf elevation angle, leaflet angle and leaflet arrangement for both light absorption and photosynthesis while phyllotaxis had no effect. Increasing the length : width ratio of leaves by 1·5 or increasing internode length from 7 cm to 12 cm led to an increase of 6-10 % for light absorption and photosynthesis. CONCLUSIONS: At high light intensities (summer) deeper penetration of light in the canopy improves crop photosynthesis, but not at low light intensities (winter). In particular, internode length and leaf shape affect the vertical distribution of light in the canopy. A new plant ideotype with more spacious canopy architecture due to long internodes and long and narrow leaves led to an increase in crop photosynthesis of up to 10 %.


Subject(s)
Light , Models, Biological , Photosynthesis , Plant Leaves/physiology , Plant Stems/growth & development , Solanum lycopersicum/physiology , Absorption , Computer Simulation , Solanum lycopersicum/growth & development , Solanum lycopersicum/radiation effects , Plant Leaves/growth & development , Plant Leaves/radiation effects , Plant Stems/physiology , Plant Stems/radiation effects , Seasons
13.
Ann Bot ; 107(5): 875-83, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21355008

ABSTRACT

BACKGROUND AND AIMS: At present most process-based models and the majority of three-dimensional models include simplifications of plant architecture that can compromise the accuracy of light interception simulations and, accordingly, canopy photosynthesis. The aim of this paper is to analyse canopy heterogeneity of an explicitly described tomato canopy in relation to temporal dynamics of horizontal and vertical light distribution and photosynthesis under direct- and diffuse-light conditions. METHODS: Detailed measurements of canopy architecture, light interception and leaf photosynthesis were carried out on a tomato crop. These data were used for the development and calibration of a functional-structural tomato model. The model consisted of an architectural static virtual plant coupled with a nested radiosity model for light calculations and a leaf photosynthesis module. Different scenarios of horizontal and vertical distribution of light interception, incident light and photosynthesis were investigated under diffuse and direct light conditions. KEY RESULTS: Simulated light interception showed a good correspondence to the measured values. Explicitly described leaf angles resulted in higher light interception in the middle of the plant canopy compared with fixed and ellipsoidal leaf-angle distribution models, although the total light interception remained the same. The fraction of light intercepted at a north-south orientation of rows differed from east-west orientation by 10 % on winter and 23 % on summer days. The horizontal distribution of photosynthesis differed significantly between the top, middle and lower canopy layer. Taking into account the vertical variation of leaf photosynthetic parameters in the canopy, led to approx. 8 % increase on simulated canopy photosynthesis. CONCLUSIONS: Leaf angles of heterogeneous canopies should be explicitly described as they have a big impact both on light distribution and photosynthesis. Especially, the vertical variation of photosynthesis in canopy is such that the experimental approach of photosynthesis measurements for model parameterization should be revised.


Subject(s)
Crops, Agricultural/growth & development , Models, Biological , Plant Leaves/growth & development , Solanum lycopersicum/growth & development , Algorithms , Crops, Agricultural/metabolism , Demography , Imaging, Three-Dimensional , Solanum lycopersicum/metabolism , Models, Anatomic , Photosynthesis , Plant Leaves/metabolism , Sunlight , Time Factors
14.
Funct Plant Biol ; 38(5): 431-440, 2011 Jun.
Article in English | MEDLINE | ID: mdl-32480898

ABSTRACT

Time-to-event analysis, or survival analysis, is a method to analyse the timing of events and to quantify the effects of contributing factors. We apply this method to data on the timing of abortion of reproductive organs. This abortion often depends on source and sink strength. We hypothesise that the effect of source and sink strength on abortion rate can be quantified with a statistical model, obtained via survival analysis. Flower and fruit abortion in Capsicum annuum L., observed in temperature and planting density experiments, were analysed. Increasing the source strength as well as decreasing the sink strength decreased the abortion rate. The effect was non-linear, e.g. source strengths above 6g CH2O per plant per d did not decrease abortion rates further. The maximum abortion rate occurred around 100 degree-days after anthesis. Analyses in which sink strength was replaced with the number of fruits in a specified age category had an equal or better fit to the data. We discuss the advantages and disadvantages of using survival analyses for this kind of data. The technique can also be used for other crops showing reproductive organ abortion (e.g. soybean (Glycine max L.), cucumber (Cucumis sativus L.)), but also on other event types like bud break or germination.

15.
Ann Bot ; 104(5): 957-64, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19643909

ABSTRACT

BACKGROUND AND AIMS: Fruit set in indeterminate plant species largely depends on the balance between source and sink strength. Plants of these species show fluctuations in fruit set during the growing season. It was tested whether differences in fruit sink strength among the cultivars explained the differences in fruit-set patterns. METHODS: Capsicum was chosen as a model plant. Six cultivars with differences in fruit set, fruit size and plant growth were evaluated in a greenhouse experiment. Fruit-set patterns, generative and vegetative sink strength, source strength and the source : sink ratio at fruit set were determined. Sink strength was quantified as potential growth rate. Fruit set was related to total fruit sink strength and the source : sink ratio. The effect of differences observed in above-mentioned parameters on fruit-set patterns was examined using a simple simulation model. KEY RESULTS: Sink strengths of individual fruits differed greatly among cultivars. Week-to-week fruit set in large-fruited cultivars fluctuated due to large fluctuations in total fruit sink strength, but in small-fruited cultivars, total fruit sink strength and fruit set were relatively constant. Large variations in week-to-week fruit set were correlated with a low fruit-set percentage. The source : sink threshold for fruit set was higher in large-fruited cultivars. Simulations showed that within the range of parameter values found in the experiment, fruit sink strength and source : sink threshold for fruit set had the largest impact on fruit set: an increase in these parameters decreased the average percentage fruit set and increased variation in weekly fruit set. Both were needed to explain the fruit-set patterns observed. The differences observed in the other parameters (e.g. source strength) had a lower effect on fruit set. CONCLUSIONS: Both individual fruit sink strength and the source : sink threshold for fruit set were needed to explain the differences observed between fruit-set patterns of the six cultivars.


Subject(s)
Fruit/genetics , Capsicum/genetics , Capsicum/growth & development , Fruit/growth & development
16.
Leukemia ; 18(10): 1705-10, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15306823

ABSTRACT

Classical t(11;14)(q13;q32) involving IGH-CCND1 is typically associated with aggressive CD5-positive mantle cell lymphoma (MCL). Recently, we identified the IGK variant of this translocation, t(2;11)(p11;q13), in three patients with a leukemic small-cell B-non-Hodgkin lymphoma. In all cases, rearrangements of the IGK and CCND1 genes were demonstrated by fluorescence in situ hybridization. Moreover, we mapped the 11q13 breakpoint of this variant translocation in the 3' region of CCND1 which contrasts with the 5' breakpoints in a standard t(11;14)(q13;q32). Expression of cyclin D1 was shown in two cases analyzed either at diagnosis or during disease progression. All three patients were asymptomatic at presentation and no initial therapy was required. One patient died of a progressive disease 58 months from diagnosis, and two patients showed stable disease after 12 months of follow-up. In two analyzed cases, mutated IGVH genes were identified. Our findings indicate that variant t(2;11)(p11;q13) does not typify a classical MCL but possibly a more indolent leukemic lymphoma originating from an antigen experienced (mutated) B cell.


Subject(s)
Chromosomes, Human, Pair 11/genetics , Chromosomes, Human, Pair 2/genetics , Cyclin D1/genetics , Gene Rearrangement, B-Lymphocyte, Heavy Chain/genetics , Immunoglobulins/genetics , Lymphoma, Non-Hodgkin/genetics , Translocation, Genetic/genetics , Adult , DNA, Neoplasm/analysis , Disease Progression , Female , Genetic Variation , Humans , Immunoglobulin Heavy Chains/genetics , Immunoglobulin Variable Region/genetics , In Situ Hybridization, Fluorescence , Karyotyping , Leukemia/genetics , Leukemia/immunology , Leukemia/pathology , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/immunology , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Lymphoma, Mantle-Cell/genetics , Lymphoma, Mantle-Cell/immunology , Lymphoma, Mantle-Cell/pathology , Lymphoma, Non-Hodgkin/immunology , Lymphoma, Non-Hodgkin/pathology , Male , Middle Aged , Mutation , Neoplasm Recurrence, Local/genetics , Neoplasm Recurrence, Local/pathology
17.
J Exp Bot ; 55(406): 2261-8, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15333643

ABSTRACT

Source strength (assimilate supply) and sink strength (assimilate demand) of the plant were varied in different ways to investigate to what extent flower/fruit abortion in sweet pepper (Capsicum annuum L.) is determined by the availability of assimilates. Source strength was varied by changing the light level, plant density, and leaf pruning. Sink strength was varied by changing the temperature and the number and position of earlier formed fruits. Shading as well as heating for short periods showed that flowers/fruits were the most susceptible to abortion during the first week after anthesis. The different experiments where source strength was varied all showed that when source strength decreased, the rate of abortion increased linearly, whether source strength was decreased by shading, high plant density, or leaf pruning. That flower and fruit abortion not only depends on the source strength but also on the sink strength of competing organs is shown by varying the number or the position of earlier formed fruits. With the same source strength, the rate of abortion showed a close relationship with the growth rate of the earlier formed competing fruits, suggesting that the induction of abortion by earlier formed fruits is due to their sink strength. Most of the variation in abortion could be related to differences in vegetative growth rate, the latter being an indicator of the source-sink ratio. However, with the same vegetative growth rate, the rate of abortion was lower for the leaf pruning treatments where no competing fruits were retained than for the fruit load treatments. This indicates that although most of the variation in abortion can be related to the source and sink strength of the plant, some effects of competing fruits can only be explained by a combination of competition and dominance.


Subject(s)
Capsicum/growth & development , Flowers/growth & development , Acclimatization , Botany/methods , Fruit , Light , Temperature
18.
J Exp Bot ; 47 Spec No: 1281-91, 1996 Aug.
Article in English | MEDLINE | ID: mdl-21245260

ABSTRACT

Dry matter partitioning is the end result of the flow of assimilates from source organs via a transport path to the sink organs. The dry matter partitioning among the sinks of a plant is primarily regulated by the sinks themselves. The effect of source strength on dry matter partitioning is often not a direct one, but indirect via the formation of sink organs. Although the translocation rate of assimilates may depend on the transport path, the transport path is only of minor importance for the regulation of dry matter partitioning at the whole plant level. To understand the regulation of dry matter partitioning by the sinks, a parameter like sink strength is needed that describes a sink's ability to influence assimilate import and is independent of the rest of the plant. The term sink strength can be defined as the competitive ability of an organ to attract assimilates. However, there is much debate and confusion about the term sink strength because this term is often not clearly defined. Sink strength has been proposed to be the product of sink size and sink activity. Although cell number is often considered as a suitable measure of sink size, it appears not always to be an important determinant of sink size. Moreover, sink strength may depend on sink age rather than sink size. A model for dry matter partitioning into generative plant parts, which is based on sink strengths of the organs, is described. The potential growth rate (potential capacity to accumulate assimilates) has been shown to be an important parameter that quantitatively reflects the sink strength of an organ. The potential growth rates of the plant's organs are not static but change dynamically. The potential growth rate of a fruit is a function of both its age and temperature. For several crops it has been shown that the dry matter partitioning into an organ can be quantitatively described as a function of its potential growth rate relative to that of the other plant organs.

19.
Ann Bot ; 74(1): 43-52, 1994 Jul.
Article in English | MEDLINE | ID: mdl-19700461

ABSTRACT

A dynamic model is developed for the simulation of the daily dry matter distribution between the generative and vegetative plant parts and the distribution among individual fruits in greenhouse cucumber. The model is based on the hypothesis that dry matter partitioning is regulated by the sink strengths of the plant organs. The sink strength of an organ is denned here as its potential growth rate, i.e. the growth rate at non-limiting assimilate supply. The sink strength of each individual fruit is described as a function of its temperature sum after anthesis and the actual temperature, that of the vegetative plant parts as a function of actual temperature only. The formation rate of nonaborting fruits is essentially a function of the source/sink ratio. Model results agreed well with the measured fluctuating distribution of dry matter between fruits and vegetative parts. The measured effects of three intensities of fruit removal were also simulated satisfactorily. When simulating the partitioning among individual fruits the final fruit size was simulated quite well. However, the growth rate of young fruits was usually overestimated and that of old fruits underestimated, because of dominance among fruits. This phenomenon could be accounted for by incorporating priority functions into the model. Finally, a sensitivity analysis of the model was performed to investigate the effects of some climatic factors, manipulations of the number of fruits on a plant and model parameters on dry matter distribution. Strategies to manipulate the dry matter distribution are discussed.

20.
Diagn Microbiol Infect Dis ; 15(5): 385-91, 1992 Jul.
Article in English | MEDLINE | ID: mdl-1643816

ABSTRACT

BACTEC PLUS high-blood-volume resin media (aerobic BP 26 vial and anaerobic BP 27 vial) were compared with standard BACTEC media (aerobic NR 6A and anaerobic NR 7A vial). A total of 2253 blood culture sets, each consisting of the four vials, were collected. Positive cultures were obtained from 403 sets and grew 428 organisms; 271 organisms were considered as significant. The BACTEC PLUS high blood volume resin (BP-HBV) media grew significantly more Staphylococcus aureus, coagulase-negative staphylococci, Candida albicans, Enterococcus faecalis, and Pseudomonas aeruginosa. After taking into account the difference of blood volume between the two systems, only S. aureus was significantly more detected by the aerobic BP 26 vial. An enhanced recovery rate with the anaerobic BP 27 vial could not be established. BP-HBV media had an enhanced recovery rate over the standard BACTEC media for S. aureus and C. albicans in patients receiving antibiotics.


Subject(s)
Bacteremia/microbiology , Bacteria/isolation & purification , Candida albicans/isolation & purification , Fungemia/microbiology , Resins, Plant , Anti-Bacterial Agents/metabolism , Culture Media , Enterococcus faecalis/isolation & purification , Evaluation Studies as Topic , Humans , Prospective Studies , Pseudomonas aeruginosa/isolation & purification , Staphylococcus/isolation & purification , Staphylococcus aureus/isolation & purification
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