20 research outputs found
Micropropagation enhances in vitro establishment and multiplication of new cultures from field grown plants of ‘Adesoto 101’ (Prunus insititia) rootstock
ISHS Acta Horticulturae 658: I International Symposium on Rootstocks for Deciduous Fruit Tree Species. 6 Pag., 2 Fig. The definitive version is available at: http://www.actahort.org/The establishment of new in vitro cultures is often a difficult task due to low
growth of initial explants. The explant has to adapt to the new nutritional and
environmental conditions, in addition to the surface-disinfection process. Since the
explant origin plays an important role, in this work, the effect of the origin of the
explants (micropropagated or conventionally propagated plants) in both
establishment and multiplication of the in vitro cultures has been studied. While
Adesoto 101 (Prunus insititia) shows interesting features as a rootstock, it has a poor
rooting ability by cuttings, what makes micropropagation the method of choice.
Explants (axillary buds), taken from plants previously micropropagated, were
compared to those from conventionally propagated plants. Field-grown and framegrown
plants were used as explant source. Three culture media, widely used for fruit
trees, were compared for both establishment and multiplication of the cultures:
Murashige y Skoog (1962), Woody Plant Medium (Lloyd and McCown, 1981) and
Quoirin and Lepoivre (1977). These media were supplemented with sucrose (3%)
and Difco-Bacto Agar (0.7 %). Best results during establishment were obtained with
explants from micropropagated plants grown either in the frame or in the field.
Plants were severely pruned to form hedges, however field growing affected
negatively the establishment of new in vitro cultures compared to frame growing.
The multiplication rate of new cultures was positively affected by previous in vitro
micropropagation of mother plants, while the multiplication rate of cultures
originated from plants propagated by cuttings decreased noticeably. Culture
medium composition had a different effect depending on the micropropagation
phase. While WP gave the best results during establishment, MS, with a higher
mineral salts concentration, induced the highest multiplication rate.This work has been funded in part by grants AGF98-0277-C4-01 and AGL2001-
2414-C04-01 both from CICYT, and CONSI+D-DGA P012/2001Peer reviewe
Survival of hereditary non-polyposis colorectal cancer patients compared with sporadic colorectal cancer patients
<p>Abstract</p> <p>Background</p> <p>Patients with hereditary non-poliposys colorectal cancer (HNPCC) have better prognosis than sporadic colorectal cancer (CRC). Aim of our retrospective study was to compare the overall survival between sporadic CRC and HNPCC patients.</p> <p>Methods</p> <p>We analyzed a cohort of 40 (25 males and 15 females) HNPCC cases with a hospital consecutive series of 573 (312 males and 261 females) sporadic CRC observed during the period 1970–1993. In 15 HNPCC patients we performed mutational analysis for microsatellite instability. Survival rates were calculated by Kaplan-Meier method and compared with log rank test.</p> <p>Results</p> <p>The median age at diagnosis of the primary CRC was 46.8 years in the HNPCC series versus 61 years in sporadic CRC group. In HNPCC group 85% had a right cancer location, vs. 57% in the sporadic cancer group. In the sporadic cancer group 61.6% were early-stages cancer (Dukes' A and B) vs. 70% in the HNPCC group (p = ns). The crude 5-years cumulative survival after the primary CRC was 94.2% in HNPCC patients vs. 75.3% in sporadic cancer patients (p < 0.0001).</p> <p>Conclusion</p> <p>Our results show that overall survival of colorectal cancer in patients with HNPCC is better than sporadic CRC patients. The different outcome probably relates to the specific tumorigenesis involving DNA mismatch repair dysfunction.</p
A survey of the clinicopathological and molecular characteristics of patients with suspected Lynch syndrome in Latin America
Background: Genetic counselling and testing for Lynch syndrome (LS) have recently been introduced in several Latin America countries. We aimed to characterize the clinical, molecular and mismatch repair (MMR) variants spectrum of patients with suspected LS in Latin America.
Methods: Eleven LS hereditary cancer registries and 34 published LS databases were used to identify unrelated families that fulfilled the Amsterdam II (AMSII) criteria and/or the Bethesda guidelines or suggestive of a dominant colorectal (CRC) inheritance syndrome.
Results: We performed a thorough investigation of 15 countries and identified 6 countries where germline genetic testing for LS is available and 3 countries where tumor testing is used in the LS diagnosis. The spectrum of pathogenic MMR variants included MLH1 up to 54%, MSH2 up to 43%, MSH6 up to 10%, PMS2 up to 3% and EPCAM up to 0.8%. The Latin America MMR spectrum is broad with a total of 220 different variants which 80% were private and 20% were recurrent. Frequent regions included exons 11 of MLH1 (15%), exon 3 and 7 of MSH2 (17 and 15%, respectively), exon 4 of MSH6 (65%), exons 11 and 13 of PMS2 (31% and 23%, respectively). Sixteen international founder variants in MLH1, MSH2 and MSH6 were identified and 41 (19%) variants have not previously been reported, thus representing novel genetic variants in the MMR genes. The AMSII criteria was the most used clinical criteria to identify pathogenic MMR carriers although microsatellite instability, immunohistochemistry and family history are still the primary methods in several countries where no genetic testing for LS is available yet.
Conclusion: The Latin America LS pathogenic MMR variants spectrum included new variants, frequently altered genetic regions and potential founder effects, emphasizing the relevance implementing Lynch syndrome genetic testing and counseling in all of Latin America countries.Radium Hospital Foundation (Oslo, Norway) in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript, Helse Sør-Øst (Norway) in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript, the French Association Recherche contre le Cancer (ARC) in the analysis, and interpretation of data, the Groupement des Entreprises Françaises dans la Lutte contre le Cancer (Gefluc) in the analysis, and interpretation of data, the Association Nationale de la Recherche et de la Technologie (ANRT, CIFRE PhD fellowship to H.T.) in the analysis, and interpretation of data and by the OpenHealth Institute in the analysis, and interpretation of data. Barretos Cancer Hospital received financial support by FINEP-CT-INFRA (02/2010)info:eu-repo/semantics/publishedVersio
Behavioral and psychosocial effects of rapid genetic counseling and testing in newly diagnosed breast cancer patients: Design of a multicenter randomized clinical trial
<p>Abstract</p> <p>Background</p> <p>It has been estimated that between 5% and 10% of women diagnosed with breast cancer have a hereditary form of the disease, primarily caused by a <it>BRCA1 </it>or <it>BRCA2 </it>gene mutation. Such women have an increased risk of developing a new primary breast and/or ovarian tumor, and may therefore opt for preventive surgery (e.g., bilateral mastectomy, oophorectomy). It is common practice to offer high-risk patients genetic counseling and DNA testing after their primary treatment, with genetic test results being available within 4-6 months. However, some non-commercial laboratories can currently generate test results within 3 to 6 weeks, and thus make it possible to provide <it>rapid </it>genetic counseling and testing (RGCT) prior to primary treatment. The aim of this study is to determine the effect of RGCT on treatment decisions and on psychosocial health.</p> <p>Methods/Design</p> <p>In this randomized controlled trial, 255 newly diagnosed breast cancer patients with at least a 10% risk of carrying a <it>BRCA </it>gene mutation are being recruited from 12 hospitals in the Netherlands. Participants are randomized in a 2:1 ratio to either a RGCT intervention group (the offer of RGCT directly following diagnosis with tests results available before surgical treatment) or to a usual care control group. The primary behavioral outcome is the uptake of direct bilateral mastectomy or delayed prophylactic contralateral mastectomy. Psychosocial outcomes include cancer risk perception, cancer-related worry and distress, health-related quality of life, decisional satisfaction and the perceived need for and use of additional decisional counseling and psychosocial support. Data are collected via medical chart audits and self-report questionnaires administered prior to randomization, and at 6 month and at 12 month follow-up.</p> <p>Discussion</p> <p>This trial will provide essential information on the impact of RGCT on the choice of primary surgical treatment among women with breast cancer with an increased risk of hereditary cancer. This study will also provide data on the psychosocial consequences of RGCT and of risk-reducing behavior.</p> <p>Trial registration</p> <p>The study is registered at the Netherlands Trial Register (NTR1493) and ClinicalTrials.gov (NCT00783822).</p
An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers
Introduction: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their metabolism and sensitivity to oxidative stress. Variability in mitochondrial genetic background can alter reactive oxygen species production, leading to cancer risk. In the present study, we tested the hypothesis that mitochondrial haplogroups modify breast cancer risk in BRCA1/2 mutation carriers. Methods: We genotyped 22,214 (11,421 affected, 10,793 unaffected) mutation carriers belonging to the Consortium of Investigators of Modifiers of BRCA1/2 for 129 mitochondrial polymorphisms using the iCOGS array. Haplogroup inference and association detection were performed using a phylogenetic approach. ALTree was applied to explore the reference mitochondrial evolutionary tree and detect subclades enriched in affected or unaffected individuals. Results: We discovered that subclade T1a1 was depleted in affected BRCA2 mutation carriers compared with the rest of clade T (hazard ratio (HR) = 0.55; 95% confidence interval (CI), 0.34 to 0.88; P = 0.01). Compared with the most frequent haplogroup in the general population (that is, H and T clades), the T1a1 haplogroup has a HR of 0.62 (95% CI, 0.40 to 0.95; P = 0.03). We also identified three potential susceptibility loci, including G13708A/rs28359178, which has demonstrated an inverse association with familial breast cancer risk. Conclusions: This study illustrates how original approaches such as the phylogeny-based method we used can empower classical molecular epidemiological studies aimed at identifying association or risk modification effects.Peer reviewe
Stereoselektive Synthese von optisch aktiven Arenchromtricarbonylkomplexen mit Lewis-basischen Substituenten
Optically active transition-metal complexes : 9.1 a general stereoselective route to α-chiral (R)-tricarbonyl(η6-ethylbenzene)chromium complexes : novel organometallic phosphine catalysts for the asymmetric hydrovinylation reaction
Treatment of (R)-[{a-(dimethylamino)ethyl}-¿6-benzene]Cr(CO)3 with esters of chloroformic acid leads to stereoselective substitution of the dimethylamino group for a chloro substituent. The reaction can be extended to systems in which the chromium arene complex, after metalation, is diastereoselectively substituted in the ortho position with carbon and silicon electrophiles to generate planar chirality. The chloro group in turn can be replaced stereoselectively for various phosphorus, nitrogen, and oxygen nucleophiles. Both substitution reactions in the benzylic position proceed via retention of configuration. The addition of cyanide is not stereospecific. The phosphine derivatives are efficient catalysts for the enantioselective hydrovinylation of styrene to 3-phenyl-1-butene. X-ray crystal structures establish the absolute configuration of (R)-[(a-chloroethyl)¿6-benzene]Cr(CO)3, (R)-[{a-(diphenylphosphanyl)ethyl}-¿6-benzene]Cr(CO)3, and (pS,S)-[1-(a-cyanoethyl)-2-methyl-¿6-benzene]Cr(CO)3