First Report of Xanthomonas cucurbitae Causing Bacterial Leaf Spot of Pumpkin on Réunion Island

Bacterial leaf spot of cucurbits caused by Xanthomonas cucurbitae (3) can be of economic importance in tropical and subtropical production areas, most often within the Cucumis, Cucurbita, and Citrullus genera. The bacterium induces angular, water-soaked leaf spots, which sometimes turn necrotic with a chlorotic halo. Scab-like lesions on fruit may also be observed (1). During 2000, water-soaked, angular leaf lesions were collected from pumpkin (Cucurbita pepo) in a production field located at Petit Serré, Réunion Island. Yellow-pigmented Xanthomonas-like bacterial colonies were isolated on yeast peptone glucose agar. Amplified fragment length polymorphism analysis was performed on four pumpkin isolates together with reference strains of X. cucurbitae (LMG 690 [type strain] and LMG 8663) and the type strain of all other valid Xanthomonas species using SacI/MspI and four primer pairs (unlabeled MspI + 1 [A, C, T, or G] primers and 5'-labeled - SacI + C primer for the selective amplification step) (N. Ah-You, L. Gagnevin, P. A. D. Grimont, S. Brisse, X. Nesme, F. Chiroleu, L. Bui Thi Ngoc, E. Jouen, P. Lefeuvre, C. Verniére, and O. Pruvost, personal communication). The four isolates from pumpkin showed identical fingerprints and were most closely related to X. cucurbitae, with evolutionary genome divergences ≤0.05 (N. Ah-You et al., personal communication). One strain from diseased pumpkin (JW210-1) was further analyzed by multilocus sequence analysis using three housekeeping gene portions (atpD, dnaK, and gyrB) as described previously (N. Ah-You et al., personal communication). Although not fully identical, this strain displayed a similarity of >99% to the two reference strains of X. cucurbitae. Pumpkin and bottle-gourd (C. maxima), squash cv. aurore (C. pepo), cucumber cv. L-04 (Cucumis sativus), melon cv. cezanne (Cucumis melo), and watermelon cv. fou-nan (Citrullus lanatus) leaves were infiltrated (10 inoculation sites per leaf; three replicates) with bacterial suspensions prepared from strains JW210-1, LMG 690, and LMG 8663 and containing approximately 1 × 10⁵ CFU ml^-1. Negative controls consisted of leaves infiltrated with sterile tris buffer. Typical, water-soaked lesions that developed into necrotic spots were observed 6 to 8 days after inoculation for all inoculated plant species-strain combinations, but not for negative controls. One month after inoculation, mean Xanthomonas population sizes recovered from leaf lesions on KC semiselective medium (2) ranged from 1 × 10⁷ to 1 × 10⁸ CFU per lesion, typical of a compatible interaction. The reported outbreak was circumscribed to a single field and did not affect the local industry. No major outbreak of bacterial leaf spot of cucurbits has been reported on Réunion Island since 2000 on any host species of X. cucurbitae. References: (1) J. F. Bradbury. Page 309 in: Guide to Plant Pathogenic Bacteria. CAB International, Slough, UK, 1986. (2) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005. (3) L. Vauterin et al. Int. J. Syst. Bacteriol. 45:472, 1995.

Organically bound tritium (OBT) for various plants in the vicinity of a continuous atmospheric tritium release

In order to quantify tritium impact on the environmental, we studied vegetation continuously exposed to a tritiated atmosphere. We chose lichens as bio-indicators, trees for determination of past tritium releases of the Valduc Centre, and lettuce as edible vegetables for dose calculation regarding neighbourhood. The Pasquill and Doury models from the literature were tested to estimate tritium concentration in the air around vegetable for distance from the release point less than 500 m. The results in tree rings show that organically bound tritium (OBT) concentration was strongly correlated with tritium releases. Using the GASCON model, the modelled variation of OBT concentration with distance was correlated with the measurements. Although lichens are recognized as bio-indicators, our experiments show that they were not convenient for environmental surveys because their age is not definitive. Thus, tritium integration time cannot be precisely determined. Furthermore, their biological metabolism is not well known and tritium concentration appears to be largely dependent on species. An average conversion rate of HTO to OBT was determined for lettuce of about 0.20-0.24% h(-1). Nevertheless, even if it is equivalent to values already published in the literature for other vegetation, we have shown that this conversion rate, established by weekly samples, varies by a factor of 10 during the different stages of lettuce development, and that its variation is linked to the biomass derivative.

Education and Consumer Informatics: Improvements in Existing Systems

Objectives To provide an overview of the current excellent research done in the field of advancements in Education and Consumer Informatics as well as studies done to better understand, the already existing systems.

Method Synopsis of the articles on education and consumer health selected for the IMIA Yearbook of Medical Informatics 2008.

Results In the domain of education, eHealth literacy becomes a key topic and a challenge, the Internet evolving as the primary medium to access health information. A system developed to measure the eHealth literacy level of consumers reflects the importance of this skill. In consumer health informatics, the selected papers emphasize valuable advances in bridging the information gap as well as the growing implementation of functioning systems.

Conclusion The selected articles highlight the need for recognising existing weak links in the healthcare system and then strengthening them through patient education and involvement, as well as possible improvements through real-world implementations.

Expression cloning of neural genes using Xenopus laevis oocytes

Expression cloning requires a representative cDNA or genomic DNA library and a host organism in which the cloned genes can be transcribed and/or translated. It likewise requires a method to detect the expressed protein using, for example, the inherent biological activity of the gene or antibodies specific for the gene product. Most successful expression cloning strategies have employed cDNA libraries constructed in plasmid or bacteriophage lambda vectors and Xenopus oocytes or cultured mammalian cells as hosts. This unit presents several protocols designed for expression cloning paradigms that rely on electrophysiological recordings from Xenopus laevis oocytes.

Education and consumer informatics: improvements in existing systems. Findings from the Yearbook 2008 Section on Education and Consumer Informatics

OBJECTIVES

To provide an overview of the current excellent research done in the field of advancements in Education and Consumer Informatics as well as studies done to better understand, the already existing systems.

METHOD

Synopsis of the articles on education and consumer health selected for the IMIA Yearbook of Medical Informatics 2008.

RESULTS

In the domain of education, eHealth literacy becomes a key topic and a challenge, the Internet evolving as the primary medium to access health information. A system developed to measure the eHealth literacy level of consumers reflects the importance of this skill. In consumer health informatics, the selected papers emphasize valuable advances in bridging the information gap as well as the growing implementation of functioning systems.

CONCLUSION

The selected articles highlight the need for recognising existing weak links in the healthcare system and then strengthening them through patient education and involvement, as well as possible improvements through real-world implementations.

Giant-block twist grain boundary smectic phases

Study of a diverse set of chiral smectic materials, each of which has twist grain boundary (TGB) phases over a broad temperature range and exhibits grid patterns in the Grandjean textures of the TGB helix, shows that these features arise from a common structure: "giant" smectic blocks of planar layers of thickness l(b) > 200 nm terminated by GBs that are sharp, mediating large angular jumps in layer orientation between blocks (60 degrees < Delta < 90 degrees ), and lubricating the thermal contraction of the smectic layers within the blocks. This phenomenology is well described by basic theoretical models applicable in the limit that the ratio of molecular tilt penetration length-to-layer coherence length is large, and featuring GBs in which smectic ordering is weak, approaching thin, melted (nematic-like) walls. In this limit the energy cost of change of the block size is small, leading to a wide variation of block dimension, depending on preparation conditions. The models also account for the temperature dependence of the TGB helix pitch.

Direct determination of niflumic acid in a pharmaceutical gel by ATR/FTIR spectroscopy and PLS calibration

A simple, rapid and convenient analytical method without sample handling procedure is proposed for the determination of niflumic acid in a pharmaceutical gel with attenuated total reflectance/Fourier transform infrared spectroscopy (ATR/FTIR). A partial least square (PLS) calibration model for the prediction of niflumic acid contents was developed using 81 and 27 spectra of standard gels as training and validation sets, respectively. The used spectral range of niflumic acid for the establishment of this model was 2300-1100 cm(-1). All spectra were obtained in the transmittance mode, then normalized and first derivative transformed. The model yielded a regression coefficient R2 equal to 1 for the training set and a root mean square error of prediction (RMSEP) equal to 0.2 for the validation set. The percentage recoveries of the method for the analysis of Niflugel ranged from 96.60 to 101.02%.

[Neonatal consequences of maternal smoking during pregnancy]

In utero tobacco consumption is a serious public health problem in France; it is very frequent and the long term consequences are not only numerous but also misinterpreted by our population. 25 to 29% of women arrive at the end of their pregnancy without stopping smoking and 50% of non smoking mothers live in an environment polluted by tobacco during pregnancy. The authors would like to stress the gravity of this situation. At the maternity hospital in Nîmes, 358 women who gave birth at term and after a normal pregnancy were enrolled in a survey and monitored with thiocyanate for their tobacco consumption. Birth weight, height, and cranial perimeter of the infants were noted at birth. Results confirmed earlier work on this subject: the three variables studied were consistently weakened by the mother's addiction to tobacco. The authors recall previous medical literature on the pathophysiology and other consequences on the brain: such as I.Q. behavior, sudden infant death syndrome, vascular alterations with possible long-term complications, as well as pulmonary alterations on which there has recently been much research. The question is raised as to why this problem is so neglected in our society and what could be done to change this state of affairs.

Transplanted BM and BM side population cells contribute progeny to the lung and liver in irradiated mice

BACKGROUND

BM cells have been shown to give rise to progeny of various cell lineages, including cells in lung and liver. This investigation evaluated whether purified BM mononuclear cells and side population (SP) cells that have hematopoietic stem-cell activity also had this property; whether a TBI preparative regimen was necessary for engraftment; and where BM-derived cells were engrafted.

METHODS

Either 1-3 million BM mononuclear cells or 2000 BM SP cells from transgenic enhanced green fluorescent protein-expressing (EGFP) mice were transplanted i.v. to unirradiated or 7-9.5 Gy irradiated recipients.

RESULTS

Flow cytometric analysis showed that lung cells (mean 45%, range 4-70%) and liver cells (mean 4%, range 0.4-8.3%) from irradiated, but not unirradiated recipients, were EGFP donor-derived. Similar results were obtained transplanting BM mononuclear cells or SP cells. Morphologically, donor-derived cells in the lung were primarily monocytes and macrophages. Additionally, lung fibroblasts and Type I, but not Type II, alveolar cells and rare cells in the bronchial epithelium were donor BM derived. In the liver, Kupffer cells, inflammatory cells and small clusters of hepatocytes, but not bile duct cells, were donor-derived.

DISCUSSION

BM mononuclear and SP cells generated progeny in some compartments of the lung and liver, but only in TBI recipients. Stem cells in BM can contribute to repair of tissue injury in some compartments, but not to the same extent in the lung and liver.

The Vesosome - A Multicompartment Drug Delivery Vehicle

Assembling structures to divide space controllably and spontaneously into subunits at the nanometer scale is a significant challenge, although one that biology has solved in two distinct ways: prokaryotes and eukaryotes. Prokaryotes have a single compartment delimited by one or more lipid-protein membranes. Eukaryotes have nested-membrane structures that provide internal compartments--such as the cell nucleus and cell organelles in which specialized functions are carried out. We have developed a simple method of creating nested bilayer compartments in vitro via the "interdigitated" bilayer phase formed by adding ethanol to a variety of saturated phospholipids. At temperatures below the gel-liquid crystalline transition, T(m), the interdigitated lipid-ethanol sheets are rigid and flat; when the temperature is raised above T(m), the sheets become flexible and close on themselves and the surrounding solution to form closed compartments. During this closure, the sheets can entrap other vesicles, biological macromolecules, or colloidal particles. The result is efficient and spontaneous encapsulation without disruption of even fragile materials to form biomimetic nano-environments for possible use in drug delivery, colloidal stabilization, or as microreactors. The vesosome structure can take full advantage of the 40 years of progress in liposome development including steric stabilization, pH loading of drugs, and intrinsic biocompatibility. However, the multiple compartments of the vesosome give better protection to the interior contents in serum, leading to extended release of model compounds in comparison to unilamellar liposomes.

Polarization-modulated smectic liquid crystal phases

Any polar-ordered material with a spatially uniform polarization field is internally frustrated: The symmetry-required local preference for polarization is to be nonuniform, i.e., to be locally bouquet-like or "splayed." However, it is impossible to achieve splay of a preferred sign everywhere in space unless appropriate defects are introduced into the field. Typically, in materials like ferroelectric crystals or liquid crystals, such defects are not thermally stable, so that the local preference is globally frustrated and the polarization field remains uniform. Here, we report a class of fluid polar smectic liquid crystals in which local splay prevails in the form of periodic supermolecular-scale polarization modulation stripes coupled to layer undulation waves. The polar domains are locally chiral, and organized into patterns of alternating handedness and polarity. The fluid-layer undulations enable an extraordinary menagerie of filament and planar structures that identify such phases.

[Magnetic resonance imaging applications in obstetrics]

PURPOSE

To review the main indications and results of magnetic resonance imaging in the pregnant women.

MATERIAL AND METHOD

We reviewed MRI practice during the pregnancy based on our own experience in a prenatal diagnostic center and data in the literature. Rapid improvement in MRI technology has allowed more extensive use, giving a good contrast-to-noise ratio and multiplanar imaging.

RESULTS

Although ultrasound provides primary screening information, final diagnosis may require further investigations. MRI, to be performed in the second and third trimester, is the non-invasive second line tool of choice in this context. The most widespread indications are for brain disease: search for a cause of ventriculomegaly or biometric abnormality, confirmation of a malformative or acquired lesion. Progressively, indications were widened to head and neck, thorax, abdomen and pelvis areas. Moreover, systematic indications include previous fetal pathology or the pregnancy context. Other MRI indications have been suggested: placental malposition, pelvimetry and maternal genito-urinary tract.

CONCLUSION

MRI is becoming the natural and necessary second line imaging technique, with increasing indications. It must be kept in mind however that all pathological conditions cannot be depicted by these morphological studies.

A humanist's legacy in medical informatics: visions and accomplishments of Professor Jean-Raoul Scherrer

OBJECTIVE

To report about the work of Prof. Jean-Raoul Scherrer, and show how his humanist vision, his medical skills and his scientific background have enabled and shaped the development of medical informatics over the last 30 years.

RESULTS

Starting with the mainframe-based patient-centered hospital information system DIOGENE in the 70s, Prof. Scherrer developed, implemented and evolved innovative concepts of man-machine interfaces, distributed and federated environments, leading the way with information systems that obstinately focused on the support of care providers and patients. Through a rigorous design of terminologies and ontologies, the DIOGENE data would then serve as a basis for the development of clinical research, data mining, and lead to innovative natural language processing techniques. In parallel, Prof. Scherrer supported the development of medical image management, ranging from a distributed picture archiving and communication systems (PACS) to molecular imaging of protein electrophoreses. Recognizing the need for improving the quality and trustworthiness of medical information on the Web, Prof. Scherrer created the Health-On-the-Net (HON) foundation.

CONCLUSIONS

These achievements, made possible thanks to his visionary mind, deep humanism, creativity, generosity and determination, have made of Prof. Scherrer a true pioneer and leader of the human-centered, patient-oriented application of information technology for improving healthcare.

[MRI in gynecology]

OBJECTIVES

To review the complementary role and contribution of magnetic resonance imaging (MRI) in gynecology diseases.

RESULTS

Tissue characterization can be obtained with T2, T1 weighted images before and after contrast medium injection and T1 fat sat sequences. Localization of the lesion and relationships with adjacent structures are facilitated by multiplanar imaging. Endometrium and ovarian follicles display high signal intensity, visualizing the normal uterine and ovarian components. The relative high signal intensity of uterine tumors facilitates evaluation of extension. Uterine leiomyoma diagnosis is supported by its low signal intensity, allowing localization, size, and number assessment, and to distinguish adenomyoma. In doubtful malformation cases, MRI may be contributive. Ovarian mass characterization can be done with MRI, particularly for dermoid cyst and endometrioma. In this case, deep endometriosis can be associated and be extensive. Recent technical advances enable fast imaging, which can be useful for pelvic floor assessment with dynamic evaluation.

CONCLUSION

MRI is becoming the complementary reference imaging tool for us. Its increasing indications are: gynecologic cancer, pelvis endometriosis, pelvis floor, indeterminate pelvis mass and fibroleiomyoma.