OP0240 A MULTIMODAL MASS SPECTROMETRY APPROACH REVEALS SPECIFIC CARTILAGE MOLECULAR PROFILES ASSOCIATED TO TYPE 2 DIABETIC PATIENTS

Background:

Osteoarthritis (OA) is mainly characterized by the progressive deterioration of articular cartilage. Recent studies support that type 2 diabetes (TD2) is a risk factor to develop OA [1, 2]. However, the molecular cartilage profile of patients combining these two diseases remains unclear, and a better understanding of the different OA phenotypes should be considered for the development of personalized medicine.

Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) is used to investigate the bimolecular distribution of proteins, lipids or metabolites through thein-situanalysis of tissue sections. Bottom-up proteomics focuses on the relative quantification of proteins. The combination of both technologies could be considered to reveal specific molecular profiles and help for patient classification.

Objectives:

The main goal of this study is to apply a multimodal mass spectrometry approach on cartilage to reveal specific lipidomic and proteomic profiles associated to TD2 patients.

Methods:

Human cartilages from OA (na=10) and OA/TD2 human patients (nb=10) were obtained from donors undergoing total knee joint replacement. Cartilage punches of 8*8mm were sectioned at 12 µm thickness for MALDI-MSI and bottom-up proteomics.

For MALDI-MSI experiments (na=6; nb=6), norharmane matrix was sprayed over the samples for the detection of lipids. Experiments were then performed in positive ion polarity at 50 µm of lateral resolution using a RapifleX MALDI Tissue-typer instrument. LipostarMSI and in-house ChemomeTricks toolbox for MATLAB software were used for data processing and analysis.

For bottom-up proteomics experiment (na=10; nb=10), proteins were extracted, separated using SDS-PAGE and digested prior to liquid chromatography separation coupled to an orbitrap MS Q-Exactive HF mass spectrometer. Proteome Discoverer, enrichR and Reactome software were used for data processing and analysis.

Results:

MALDI-MSI showed overall differences between OA and OA/TD2 patients based on their specific lipidomic profiles. In particular, sphingomyelin and phosphatidylcholine species were significantly more abundant in OA patients whereas lysolipids such as lysophosphatidylcholine species were mainly present in OA/TD2 patients, providing therefore phenotype-specific OA molecular panels. Additionally, we observed that phosphatidylcholine and sphingomyelin species were more present in the superficial layer of the cartilage whereas lysophosphatidylcholine species were more abundant in the deep layer (Fig. 1A, B).

Proteomics experiments applied on cartilage enables the quantification of 114 proteins. Among those, 73 were overexpressed in OA samples whereas 41 were overexpressed in OA/TD2 patients. Among the differentially regulated proteins (Fig. 1C), phospholipase A2 was increased in the diabetic cohort, in line with the elevated level of lysolipids found in the imaging data. Our results also involved the fatty acid omega oxidation and the fatty acid biosynthesis pathways as relevant to explain this deregulation of the lipid metabolism.

Conclusion:

MALDI–MSI combined with proteomics experiments showed different profiles between OA and OA/TD2 patients and could be employed for patient classification.

References:

[1]Louati, K., et al., Association between diabetes mellitus and osteoarthritis: systematic literature review and meta-analysis. RMD Open, 2015.1(1): p. e000077.

[2]Williams, M.F., et al.,Type 2 diabetes and osteoarthritis: a systematic review and meta-analysis.J Diabetes Complications, 2016.30(5): p. 944-50.

Acknowledgments:

The Dutch Province of Limburg and MUMC institutional grant.

Disclosure of Interests:

Maxime Eveque: None declared, Pieter Emans Shareholder of: Shareholder and cofounder start-up company Chondropeptix, Grant/research support from: Institution received grants from STW, ReumaNederland, InSciTE, Consultant of: Consultancy to Kiomed, Speakers bureau: Payment for lectures by Kiomed, Episurf, Britt Claes: None declared, Freek Bouwman: None declared, Ron M A Heeren: None declared, Berta Cillero-Pastor: None declared

Increased High-Density Lipoprotein Levels Associated with Age-Related Macular Degeneration: Evidence from the EYE-RISK and European Eye Epidemiology Consortia

PURPOSE

Genetic and epidemiologic studies have shown that lipid genes and high-density lipoproteins (HDLs) are implicated in age-related macular degeneration (AMD). We studied circulating lipid levels in relationship to AMD in a large European dataset.

DESIGN

Pooled analysis of cross-sectional data.

PARTICIPANTS

Individuals (N = 30 953) aged 50 years or older participating in the European Eye Epidemiology (E3) consortium and 1530 individuals from the Rotterdam Study with lipid subfraction data.

METHODS

AMD features were graded on fundus photographs using the Rotterdam classification. Routine blood lipid measurements, genetics, medication, and potential confounders were extracted from the E3 database. In a subgroup of the Rotterdam Study, lipid subfractions were identified by the Nightingale biomarker platform. Random-intercepts mixed-effects models incorporating confounders and study site as a random effect were used to estimate associations.

MAIN OUTCOME MEASURES

AMD features and stage; lipid measurements.

RESULTS

HDL was associated with an increased risk of AMD (odds ratio [OR], 1.21 per 1-mmol/l increase; 95% confidence interval [CI], 1.14-1.29), whereas triglycerides were associated with a decreased risk (OR, 0.94 per 1-mmol/l increase; 95% CI, 0.91-0.97). Both were associated with drusen size. Higher HDL raised the odds of larger drusen, whereas higher triglycerides decreases the odds. LDL cholesterol reached statistical significance only in the association with early AMD (P = 0.045). Regarding lipid subfractions, the concentration of extra-large HDL particles showed the most prominent association with AMD (OR, 1.24; 95% CI, 1.10-1.40). The cholesteryl ester transfer protein risk variant (rs17231506) for AMD was in line with increased HDL levels (P = 7.7 × 10-7), but lipase C risk variants (rs2043085, rs2070895) were associated in an opposite way (P = 1.0 × 10-6 and P = 1.6 × 10-4).

CONCLUSIONS

Our study suggested that HDL cholesterol is associated with increased risk of AMD and that triglycerides are negatively associated. Both show the strongest association with early AMD and drusen. Extra-large HDL subfractions seem to be drivers in the relationship with AMD, and variants in lipid genes play a more ambiguous role in this association. Whether systemic lipids directly influence AMD or represent lipid metabolism in the retina remains to be answered.

Determinants of macular pigment optical density and its relation to age-related maculopathy: results from the Muenster Aging and Retina Study (MARS)

PURPOSE

The controversial protective effect of macular pigment (MP), consisting of lutein (L) and zeaxantin (Z), in age-related maculopathy (ARM) and its late-stage, age-related macular degeneration (AMD) is discussed. Determinants of MP optical density (MPOD) and its relation to ARM were investigated.

METHODS

MPOD was accessed at eccentricities of 0.5° and 2.0° from the fovea in 369 participants in the 2.6-year follow-up examination of the prospective Muenster Aging and Retina Study using dual-wavelength analysis of autofluorescence images. ARM was graded from standardized fundus photographs according to the International Classification System.

RESULTS

MPOD at 0.5° and 2.0° between pairs and within single eyes was strongly correlated (P < 0.001). Smoking and body mass index showed moderately inverse associations with MPOD at 2.0°, and age was positively related to MPOD at both eccentricities. Serum L, measured at the baseline examination, was significantly associated with MPOD measured at follow-up. Likewise, use of L/Z-containing supplements raised MPOD. Crude mean MPOD increased with ascending stage of ARM. However, adjustment for influential factors and exclusion of L supplement users removed differences of mean MPOD between ARM stages. Considering further the accompanying eye, study eyes with ARM had significantly higher MPOD when the contralateral eye had AMD.

CONCLUSIONS

MPOD levels showed a high degree of intraindividual concordance and interindividual variability. Long-standing serum L levels, and in particular L supplementation, were the strongest determinants of MPOD. The hypothetical inverse association between MPOD and ARM stage was not confirmed.

Prediction of lymph node involvement in breast cancer from primary tumor tissue using gene expression profiling and miRNAs

The aim of this study was to investigate whether lymph node involvement in breast cancer is influenced by gene or miRNA expression of the primary tumor. For this purpose, we selected a very homogeneous patient population to minimize heterogeneity in other tumor and patient characteristics. First, we compared gene expression profiles of primary tumor tissue from a group of 96 breast cancer patients balanced for lymph node involvement using Affymetrix Human U133 Plus 2.0 microarray chip. A model was built by weighted Least-Squares Support Vector Machines and validated on an internal and external dataset. Next, miRNA profiling was performed on a subset of 82 tumors using Human MiRNA-microarray chips (Illumina). Finally, for each miRNA the number of significant inverse correlated targets was determined and compared with 1000 sets of randomly chosen targets. A model based on 241 genes was built (AUC 0.66). The AUC for the internal dataset was 0.646 and 0. 651 for the external datasets. The model includes multiple kinases, apoptosis-related, and zinc ion-binding genes. Integration of the microarray and miRNA data reveals ten miRNAs suppressing lymph node invasion and one miRNA promoting lymph node invasion. Our results provide evidence that measurable differences in gene and miRNA expression exist between node negative and node positive patients and thus that lymph node involvement is not a genetically random process. Moreover, our data suggest a general deregulation of the miRNA machinery that is potentially responsible for lymph node invasion.

Prevalent breast cancer patients with a homozygous mutant status for CYP2D6*4: response and biomarkers in tamoxifen users

Retrospective studies suggest that single nucleotide polymorphisms in the cytochrome P450 2D6 (CYP2D6) gene predict reduced tamoxifen metabolism, better tolerance and worse treatment outcome. We hypothesized that women with this genotype lack tamoxifen-induced endometrial and biochemical changes in follicle-stimulating hormone (FSH) and sex hormone-binding globulin (SHBG). We identified 56 breast cancer patients attending the follow-up clinic with a homozygous mutant (HM) status for the CYP2D6*4 null variant. Here, we report a detailed assessment of tamoxifen activity in 19 CYP2D6 HM women, while they were using tamoxifen either for metastatic (n = 5) or for early disease (n = 14). We assessed response to tamoxifen in metastatic disease. Endometrial appearances and serum levels of FSH and SHBG were assessed from retrospective and prospective testing. Our findings do suggest that the presence of two CYP2D6*4 alleles does not exclude a durable response of tamoxifen in metastatic breast cancer. The transvaginal ultrasonographic appearance of the endometrium in CYP2D6*4/*4 patients on tamoxifen is similar as seen in the normal population of tamoxifen users. The endometrium is increased in thickness with subepithelial cysts and endometrial polyps. Serum levels of FSH and SHBG in CYP2D6*4 HM tamoxifen users were in the range of what would be expected during tamoxifen treatment in the general population. Our findings do show CYP2D6*4/*4 carriers to have activity of tamoxifen on breast cancer, endometrium and serum levels of FSH and SHBG. They support clinical trials prospectively testing the effect of CYP2D6 genetic variability in response to tamoxifen before denying this drug to breast cancer patients only based on their CYP2D6*4 status.

The role of KRAS, BRAF, NRAS, and PIK3CA mutations as markers of resistance to cetuximab in chemorefractory metastatic colorectal cancer

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Background: KRAS mutations (MUT) negatively affect outcome after cetuximab (CTX) in metastatic colorectal cancer (mCRC). As only 40% of KRAS wild-type (WT) respond it is possible that other MUT, constitutively activating the Ras/Erk or PI3K/Akt pathways, are present in the non-responding KRAS WT. We analyzed the KRAS, BRAF, NRAS & PIK3CA MUT status in 276 chemorefractory CRC treated with CTX +- irinotecan and correlated the MUT status with outcome. Methods: KRAS codon 12,13, 61&146, BRAF V600E, NRAS codon 12&13, PIK3CA E542K, E545K, A, G, V (exon 9), H1047Y, R, L (exon 20), N345K, R88Q and Q546K MUT were evaluated on FFPE primary CRC using the Sequenom MALDI TOF MassArray system. A two- sided Fisher's exact test was used to evaluate the association between PIK3CA, KRAS, BRAF & NRAS MUT and objective response (OR). Progression-free (PFS) and overall survival (OS) were estimated by the Kaplan-Meier method. Results: 116/276 (42%) CRC had a KRAS MUT, 96% of which occurred in codon 12 or 13. KRAS WT was associated with OR (p<.0001), longer median PFS (p<.0001) and OS (p<.0001). 15/153 (9.8%) KRAS WT had a BRAF MUT. BRAF WT was associated with OR (p=.01), longer PFS (p<.0001) and OS (p=.007). 5/98 (5%) KRAS WT had an NRAS MUT and none of these showed OR. KRAS, BRAF and NRAS MUT were mutually exclusive. The combined KRAS/BRAF/NRAS WT state was associated with OR (p<.0001), longer PFS (p<.0001) and OS (p<.0001). 23/200 (12%) CRC carried a PIK3CA mutation: 5/39 (13%) of responders and 18/160 (11%) of non-responders (p=.781). Median PFS and OS were not associated with PIK3CA MUT state (p=.760 & p=.698) overall, nor in the KRAS/BRAF/NRAS WT subgroup (p=.946 & p=.509). 5/13 (38.5%) PIK3CA MUT KRAS/BRAF/NRAS WT CRC showed an OR. 13/107 (12%) of KRAS/BRAF/NRAS WT and 10/93 (11%) of KRAS/BRAF/NRAS MUT tumors harbored a PIK3CA MUT (p=.826). Conclusions: KRAS, BRAF & NRAS MUT are mutually exclusive and occur in at least 47% of CRC. Like KRAS WT, BRAF WT state of the primary is significantly associated with outcome in mCRC treated with CTX. The combined KRAS/BRAF/NRAS WT state is significantly associated with outcome. PIK3CA MUT occur independently of the KRAS/BRAF/NRAS MUT status. We cannot provide any evidence for a strong role of PIK3CA MUT as a marker in determining outcome to CTX.

[Table: see text]

Critical Care Nurses’ Knowledge of Evidence-Based Guidelines for Preventing Infections Associated With Central Venous Catheters: An Evaluation Questionnaire

Background Lack of adherence to recommended evidence-based guidelines for preventing infections associated with use of central venous catheters may be due to nurses’ lack of knowledge of the guidelines.

Objective To develop a reliable and valid questionnaire for evaluating critical care nurses’ knowledge of evidence-based guidelines for preventing infections associated with central venous catheters.

Methods A total of 10 nursing-related strategies were identified from current evidence-based guidelines for preventing infections associated with use of central venous catheters. Face and content validation were determined for selected interventions and multiple-choice questions (1 question per intervention). The test results of 762 critical care nurses were evaluated for item difficulty, item discrimination, and quality of the response alternatives or options for answers (possible responses).

Results All 10 items had face and content validity. Values for item difficulty ranged from 0.1 to 0.9. Values for item discrimination ranged from 0.05 to 0.41. The quality of the response alternatives (0.0–0.8) indicated widespread misconceptions among the critical care nurses in the sample.

Conclusion The questionnaire is reliable and has face and content validity. Findings from surveys in which this questionnaire is used can lead to better educational programs for critical care nurses on infections associated with use of central venous catheters.

Critical care nurses' knowledge of evidence-based guidelines for preventing infections associated with central venous catheters: an evaluation questionnaire

BACKGROUND

Lack of adherence to recommended evidence-based guidelines for preventing infections associated with use of central venous catheters may be due to nurses' lack of knowledge of the guidelines.

OBJECTIVE

To develop a reliable and valid questionnaire for evaluating critical care nurses' knowledge of evidence-based guidelines for preventing infections associated with central venous catheters.

METHODS

A total of 10 nursing-related strategies were identified from current evidence-based guidelines for preventing infections associated with use of central venous catheters. Face and content validation were determined for selected interventions and multiple-choice questions (1 question per intervention). The test results of 762 critical care nurses were evaluated for item difficulty, item discrimination, and quality of the response alternatives or options for answers (possible responses).

RESULTS

All 10 items had face and content validity. Values for item difficulty ranged from 0.1 to 0.9. Values for item discrimination ranged from 0.05 to 0.41. The quality of the response alternatives (0.0-0.8) indicated widespread misconceptions among the critical care nurses in the sample.

CONCLUSION

The questionnaire is reliable and has face and content validity. Findings from surveys in which this questionnaire is used can lead to better educational programs for critical care nurses on infections associated with use of central venous catheters.

Modeling Smoking History: A Comparison of Different Approaches in the MARS Study on Age-Related Maculopathy

PURPOSE

Smoking is an established risk factor for the development of age-related maculopathy (ARM), and its end stage, age-related macular degeneration (AMD). We evaluated the benefit of various smoking-related variables in modeling the association of smoking with ARM and AMD in a mixed sample of current, former, and never smokers.

METHODS

This was a cross-sectional study in participants of the Muensteraner Altern- und Retina-Studie (MARS). Participants were classified according to the Rotterdam classification system as healthy, or having ARM or AMD. Using multinomial logistic regression techniques, the association with number of cigarettes, years of smoking, pack-years and time since cessation in former smokers were evaluated.

RESULTS

Mean age of the 982 participants (58.6% females) was 70.9 +/- 5.5 years. ARM was present in 483 (49.2%) and AMD in 285 (29.0%) individuals. The adjusted prevalence odds ratio (OR) in current smokers versus never smokers was 2.61 (95% confidence interval [CI] 1.34-5.09) for ARM and 3.94 (95% CI 1.91-8.14) for AMD. This effect decreased in former smokers with an OR = 0.55 (95% CI 0.33-0.99) per log-transformed time since smoking cessation for ARM and an OR = 0.52 (95% CI 0.30-0.90) for AMD.

CONCLUSIONS

By including a variable for time since smoking cessation, we were able to handle current, former, and never smokers in one model that estimates the association of smoking with ARM or AMD. Logarithmical transformation of the time since smoking cessation seemed to increase the model fit and to reflect a non-linear protective effect of smoking cessation on the onset of ARM and AMD in former smokers.

Critical Care Nurses’ Knowledge of Evidence-Based Guidelines for Preventing Ventilator-Associated Pneumonia: An Evaluation Questionnaire

Background Nurses’ lack of knowledge may be a barrier to adherence to evidence-based guidelines for preventing ventilator-associated pneumonia.

Objective To develop a reliable and valid questionnaire for evaluating critical care nurses’ knowledge of evidence-based guidelines for preventing ventilator-associated pneumonia.

Methods Ten nursing-related interventions were identified from a review of evidence-based guidelines for preventing ventilator-associated pneumonia. Selected interventions and multiple-choice questions (1 question per intervention) were subjected to face and content validation. Item difficulty, item discrimination, and the quality of the response alternatives or options for answers (possible responses) were evaluated on the test results of 638 critical care nurses.

Results Face and content validity were achieved for 9 items. Values for item difficulty ranged from 0.1 to 0.9. Values for item discrimination ranged from 0.10 to 0.65. The quality of the response alternatives led to the detection of widespread misconceptions among critical care nurses.

Conclusion The questionnaire is reliable and has face and content validity. Results of surveys with this questionnaire can be used to focus educational programs on preventing ventilator-associated pneumonia.

Critical care nurses' knowledge of evidence-based guidelines for preventing ventilator-associated pneumonia: an evaluation questionnaire

BACKGROUND

Nurses' lack of knowledge may be a barrier to adherence to evidence-based guidelines for preventing ventilator-associated pneumonia.

OBJECTIVE

To develop a reliable and valid questionnaire for evaluating critical care nurses' knowledge of evidence-based guidelines for preventing ventilator-associated pneumonia.

METHODS

Ten nursing-related interventions were identified from a review of evidence-based guidelines for preventing ventilator-associated pneumonia. Selected interventions and multiple-choice questions (1 question per intervention) were subjected to face and content validation. Item difficulty, item discrimination, and the quality of the response alternatives or options for answers (possible responses) were evaluated on the test results of 638 critical care nurses.

RESULTS

Face and content validity were achieved for 9 items. Values for item difficulty ranged from 0.1 to 0.9. Values for item discrimination ranged from 0.10 to 0.65. The quality of the response alternatives led to the detection of widespread misconceptions among critical care nurses.

CONCLUSION

The questionnaire is reliable and has face and content validity. Results of surveys with this questionnaire can be used to focus educational programs on preventing ventilator-associated pneumonia.

The expression of the salt-responsive gene salT from rice is regulated by hormonal and developmental cues

The expression pattern of the salT gene was analyzed in different cell types and organs of rice (Oryza sativa L.) in response to saline and hormonal treatments to obtain detailed information on the physiological cues controlling gene expression. Gel blot analysis of RNA and in-situ hybridization performed on seedlings grown for 10 ds in the presence of 1% NaCl revealed that salT was expressed mainly in the younger tissues of the plant. In contrast, 6-week-old plants exhibited maximal salT mRNA accumulation in sheaths of older leaves. In addition, salT was normally expressed in rapidly dividing suspension-cultured cells, but not in quiescent ones. Altogether, these results may indicate that salT expression in each region of the plant is dependent on the metabolic activity of the cells as well as on whether or not they are stressed. The effects of two growth regulators, abscisic acid (ABA) and gibberellic acid, were investigated in combination with the effects of NaCl. Gibberellic acid had a synergistic effect on the induction of the salT gene when combined with 0.5% NaCl, but did not induce salT on its own. At 10 microM, ABA induced salT both in the absence of NaCl and in its presence. Whereas 1 microM ABA acted additively with NaCl to induce gene expression, 5 microM ABA with NaCl was only as effective as NaCl alone. This may indicate that the two stimuli act independently and possibly through antagonistic signal transduction pathways.

Clonidine added to bupivacaine-epinephrine-sufentanil improves epidural analgesia during childbirth

BACKGROUND AND OBJECTIVES

A double-blind study was conducted to assess the efficacy and the side effects of a low dose of clonidine added to an epidural injection of bupivacaine and epinephrine, with or without sufentanil.

METHODS

One hundred healthy parturients (ASA 1) were randomly allocated into four groups according to the type of epidural analgesia administered. The bupivacaine/epinephrine (BE) group received a 10-mL standard injection of bupivacaine (B) 1.25 mg/mL and epinephrine (E) 1.25 microg/mL. In the bupivacaine/epinephrine/sufentanil (BES) group, 7.5 microg sufentanil (S) was added to the BE mixture. For the bupivacaine/ epinephrine/clonidine (BEC) group, 50 microg clonidine (C) was added to the BE mixture, whereas for the bupivacaine/epinephrine/sufentanil/clonidine (BESC) group, both sufentanil and clonidine were added to BE. Fetal heart rate was monitored by continuous cardiotocography. Duration of analgesia, method of delivery, and neonatal outcome (measured using APGAR score, peripheral oxygen saturation, and neurologic adaptive capacity score) and side effects of clonidine were observed. The parturients were routinely asked for their global appreciation of the epidural analgesia technique by visual analog score, 2 hours postpartum.

RESULTS

The overall quality and duration of analgesia were superior in the BESC group compared with the other groups, as was the global appreciation by the parturient. The frequency of side effects in the clonidine groups was comparable, with the exception of hypotension and sedation. Hypotension was easily treated by fluids or ephedrine and caused no fetal distress. The level of sedation was mild, and all parturients aroused immediately after verbal commands.

CONCLUSION

The addition of a low dose of clonidine to an epidural injection of bupivacaine with epinephrine and sufentanil provides better analgesia during labor, while keeping the side effects minimal and of minor clinical importance.

Heat-inducible rice hsp82 and hsp70 are not always co-regulated

We have characterized several heat-shock-induced genes in rice (Oryza sativa L.) and compared their expression under a variety of conditions. Three of these genes, which are analogs of the hsp82/90 family, lie within a cloned 18-kilobase (kb) region of the genome. The middle member of this cluster, designated hsp82B, has been fully sequenced. The gene uses a promoter containing six putative heat-shock elements as well as several unusual sequence motifs including a stretch of 11 thymidines alternating with 11 adenosines. The mRNA for this gene reaches its highest relative level of expression within 120 min after plants are shifted to 42 degrees C; no other conditions induce this gene. By contrast, we found that during heat stress the expression of hsp70 correlates well with increases in internal ion concentrations, and can also be induced by excess salt or ethanol at normal growth temperatures. These results appear to indicate that whereas hsp70 is induced by all stresses that lead to protein denaturation-including heat stress-HSP82 mRNA accumulates only upon heat stress.

Organ-dependent regulation of a plant promoter isolated from rice by 'promoter-trapping' in tobacco

A vector containing a transcriptionally inactive neomycin phosphotransferase II gene was used to select promoter sequences from a pool of random genomic DNA fragments. This paper describes how one such sequence (P4.7) isolated from Oryza sativa acts as a hormonally regulated promoter in Nicotiana tabacum. Relative expression ratios in leaf, root, midrib, callus, and stem tissue of tobacco plants are 1:5:4:10:17. Histochemical assays show that P4.7 activates the uidA reporter gene throughout the phloem and cortex of tobacco stems. Transcription from the P4.7 fragment is inducible in leaf tissue by low levels of alpha-naphthalene acetic acid or 6-benzyl-aminopurine, even when cell proliferation is inhibited by colchicine or hydroxyurea. Conversely, 1% DMSO was found to inhibit activation of P4.7 without interfering with callus formation. The fragment contains TATA and CAAT sequences normally found at the 5' end of many plant genes, and an additional region homologous to sequences located in similar positions in a variety of similarly regulated promoters. Promoter deletion and fusion experiments have indicated the location of a stem enhancer element in P4.7. The promoter trap system we have described may potentially be used to characterize transcriptional factors common to monocot and dicot species.

Flavomycin effects on performance of beef bulls and nutrient digestibility in wethers

For 28 weeks a feeding experiment was conducted to determine the effects of dietary flavomycin on performance of beef bulls. In the first and second half of the trial, 40 animals (average initial weight 352 kg) had free access to corn silage or beet pulp, respectively, both supplemented with an appropriate concentrate containing 0 or 10 mg/kg of the antibiotic. Daily flavomycin intake was 39 to 46 mg when the animals were on the corn silage diet and 51 to 54 mg when they were fed the beet pulp diet. The animals fed the corn silage-based diet supplemented with flavomycin showed a non-significant improvement of daily gain (1.4%) and feed conversion (2.3%). When the beet pulp-based diet was fed, flavomycin significantly increased daily gain (15.2%, P less than 0.002) and feed conversion efficiency (9.1%, P less than 0.03). For the overall feeding experiment the positive effect of flavomycin feeding was 6.7% on body weight gain (P less than 0.09) and 5.2% on feed conversion (P less than 0.13). Flavomycin did not affect carcass yield of beef bulls. Also the effect of flavomycin on diet digestibility was studied in wethers fed a mixture of beet pulp and concentrate, containing 0 or 10 ppm flavomycin. No significant effect from the antibiotic on digestion of dry matter, crude protein, fibre, fat, ash and N-free extract was observed.

Transient Gene Expression in Intact and Organized Rice Tissues

Regulated gene expression of chimeric genes has been studied extensively in electroporated protoplasts. The applicability of these assays is limited, however, because protoplasts are not always physiologically identical to the cells from which they are derived. We have developed a procedure to electroporate DNA into intact and organized leaf structures of rice. Optimization of the new gene delivery system mainly involved eliminating explant-released nucleases, prolonging the DNA/explant incubation time, and expanding the pulse time. Using a [beta]-glucuronidase gene under the control of constitutive promoters, we demonstrated that all cell types within a leaf base were susceptible to electroporation-mediated DNA uptake. Although the technique was initially developed for leaf bases of young etiolated rice seedlings, we proved that it was equally applicable both to other monocotyledons, including wheat, maize, and barley, and to other explants, such as etiolated and green sheath and lamina tissues from rice. Transient gene expression assays with electroporated leaf bases showed that the promoter from a pea light-harvesting chlorophyll a/b-binding protein gene displayed both light- and chloroplast-dependent expression in rice, and that the promoter from the Arabidopsis S-adenosylmethionine synthetase gene was, as in transgenic Arabidopsis and tobacco, preferentially expressed in cells surrounding the vascular bundles.

Transient Gene Expression in Intact and Organized Rice Tissues

Regulated gene expression of chimeric genes has been studied extensively in electroporated protoplasts. The applicability of these assays is limited, however, because protoplasts are not always physiologically identical to the cells from which they are derived. We have developed a procedure to electroporate DNA into intact and organized leaf structures of rice. Optimization of the new gene delivery system mainly involved eliminating explant-released nucleases, prolonging the DNA/explant incubation time, and expanding the pulse time. Using a [beta]-glucuronidase gene under the control of constitutive promoters, we demonstrated that all cell types within a leaf base were susceptible to electroporation-mediated DNA uptake. Although the technique was initially developed for leaf bases of young etiolated rice seedlings, we proved that it was equally applicable both to other monocotyledons, including wheat, maize, and barley, and to other explants, such as etiolated and green sheath and lamina tissues from rice. Transient gene expression assays with electroporated leaf bases showed that the promoter from a pea light-harvesting chlorophyll a/b-binding protein gene displayed both light- and chloroplast-dependent expression in rice, and that the promoter from the Arabidopsis S-adenosylmethionine synthetase gene was, as in transgenic Arabidopsis and tobacco, preferentially expressed in cells surrounding the vascular bundles.

Characterization of a rice gene showing organ-specific expression in response to salt stress and drought

Protein changes induced by salinity stress were investigated in the roots of the salt-sensitive rice cultivar Taichung native 1. We found eight proteins to be induced and obtained partial sequences of one with a molecular mass of 15 kilodaltons and an isoelectric point of 5.5. Using an oligonucleotide probe based on this information, a cDNA clone, salT, was selected and found to contain an open reading frame coding for a protein of 145 amino acid residues. salT mRNA accumulates very rapidly in sheaths and roots from mature plants and seedlings upon treatment with Murashige and Skoog salts (1%), air drying, abscisic acid (20 microM), polyethylene glycol (5%), sodium chloride (1%), and potassium chloride (1%). Generally, no induction was seen in the leaf lamina even when the stress should affect all parts of the plant uniformly. The organ-specific response of salT is correlatable with the pattern of Na+ accumulation during salt stress.

Evaluation of selectable markers for rice transformation

A variety of expression systems and selection régimes have been developed to transform plants such as tobacco, petunia, and tomato. We investigated several of these to determine whether the promoters and selectable markers used in dicotyledonous plants are suitable for selecting transformed rice callus. We compared transient expression driven by constitutive and regulated promoters in rice (Oryza sativa) protoplasts and found that the 2' promoter of the octopine T-DNA is approximately 3 to 4 times more efficient than the CAMV 35S promoter, 10 times more efficient than the nos promoter and the 1' promoter, and more than 100 times better than two other regulated plant promoters. Similar results were obtained in tobacco (Nicotiana tabacum) protoplasts with the exception that the nos promoter was expressed nearly 10 times better in rice. Further studies demonstrated that rice callus growth is sensitive to low concentrations of methotrexate, phosphinothricin, and bleomycin, and to moderate concentrations of G418 and hygromycin, but is only partially inhibited by relatively high concentrations of kanamycin. Finally, we tested the ability of stably introduced resistance genes to protect callus against some of the selective agents. Genes that inactivated phosphinothricin or G418 permitted transformed calli to grow almost unimpeded on toxic concentrations of these selective agents. However, a gene conferring resistance to methotrexate could not be used to select for activily growing transformants. Southern analysis of the transformed cell lines demonstrated that 50% of the transformants contained a single plasmid copy and that nearly all integrated copies showed rearrangements. These results on the use of selectable markers in rice should facilitate efforts to obtain transformants of this important grain.

[Ileo-ureteral reflux after urinary diversion through an ileal conduit]

The authors made a comparative study (intravenous urography, loopography and loopomanometry) between patients with inverted antireflux anastomosis, as proposed by Melchior, and 12 patients with classical uretero-ileostomy (Bricker bladder). Inverting the anastomosis results in greater incidence of obstruction, while less complications were seen using the classical technique. The importance of reflux in ileal loops and the validity of the classical and manometry loopogram is discussed. Antireflux procedure is only indicated in cases with dilated ureters.