Association of the I1307K APC mutation with hereditary and sporadic breast/ovarian cancer: more questions than answers

The frequency of the APC I1307K mutation and its association with disease pattern was examined in 996 Ashkenazi women consisting of individuals with either sporadic (n = 382) or hereditary (n = 143) breast and/or ovarian cancer; asymptomatic BRCA1/2 mutation carriers (185delAG, 5382insC and 6174delT) (n = 53) and healthy controls (n = 418). The I1307K allele was equally distributed among women with sporadic (17/382; 4.6%) and inherited (10/143; 7%) breast and/or ovarian cancer irrespective of their being diagnosed before or after 42 years of age and among asymptomatic (7/53; 13.2%) and cancer manifesting BRCA1/2 carriers (10/143; 7%). Taken together, the prevalence of the I1307K allele was significantly higher in BRCA1/2 carriers compared to non-BRCA1/2 carriers (17/196; 8.7% and 40/800, 5%; respectively). The high prevalence of the I1307K allele among BRCA1/2 carriers is not associated with increased cancer risk but seems to be genetically connected because of Jewish ancestry. © 2000 Cancer Research Campaig

Electrical Modelling of In-Vivo Impedance Spectroscopy of Nicotiana tabacum Plants

Electrical impedance spectroscopy has been suggested as a sensing method for plants. Here, a theoretical approach for electrical conduction via the plant stem is presented and validated, linking its living electrical characteristics to its internal structure. An electrical model for the alternating current conduction and the associated impedance in a live plant stem is presented. The model accounts for biological and geometrical attributes. It uses the electrically prevalent coupled transmission line model approach for a simplified description of the complicated vessel structure. It considers the electrode coupling to the plant stem (either Galvanic or Faradic), and accounts for the different interactions of the setup. Then the model is simplified using the lumped element approach. The model is then validated using a four-point probe impedance spectroscopy method, where the probes are galvanically coupled to the stem of Nicotiana tabacum plants. The electrical impedance data was collected continuously and the results exhibit an excellent fitting to the theoretical model, with a fitting error of less than 1.5% for data collected on various days and plants. A parametric evaluation of the fitting corresponds to the proposed physically based model, therefore providing a baseline for future plant sensor design

Prevalence of BRCA1 and BRCA2 Jewish mutations in Spanish breast cancer patients

We screened the 185delAG and 5382insC (BRCA1) and the 6174delT (BRCA2) mutation in 298 Spanish women with breast cancer. Two women (one with Sephardic ancestors) presented the 185delAG mutation and the same haplotype reported in Ashkenazim with this mutation. This suggests a common origin of the 185delAG in both Sephardic and Ashkenazi populations. © 1999 Cancer Research Campaig

Presymptomatic breast cancer in Egypt: role of BRCA1 and BRCA2 tumor suppressor genes mutations detection

<p>Abstract</p> <p>Background</p> <p>Breast cancer is one of the most common diseases affecting women. Inherited susceptibility genes, <it>BRCA1 </it>and <it>BRCA2</it>, are considered in breast, ovarian and other common cancers etiology. <it>BRCA1 </it>and <it>BRCA2 </it>genes have been identified that confer a high degree of breast cancer risk.</p> <p>Objective</p> <p>Our study was performed to identify germline mutations in some exons of <it>BRCA1 </it>and <it>BRCA2 </it>genes for the early detection of presymptomatic breast cancer in females.</p> <p>Methods</p> <p>This study was applied on Egyptian healthy females who first degree relatives to those, with or without a family history, infected with breast cancer. Sixty breast cancer patients, derived from 60 families, were selected for molecular genetic testing of <it>BRCA1 </it>and <it>BRCA2 </it>genes. The study also included 120 healthy first degree female relatives of the patients, either sisters and/or daughters, for early detection of presymptomatic breast cancer mutation carriers. Genomic DNA was extracted from peripheral blood lymphocytes of all the studied subjects. Universal primers were used to amplify four regions of the <it>BRCA1 </it>gene (exons 2,8,13 and 22) and one region (exon 9) of <it>BRCA2 </it>gene using specific PCR. The polymerase chain reaction was carried out. Single strand conformation polymorphism assay and heteroduplex analysis were used to screen for mutations in the studied exons. In addition, DNA sequencing of the normal and mutated exons were performed.</p> <p>Results</p> <p>Mutations in both <it>BRCA1 </it>and <it>BRCA2 </it>genes were detected in 86.7% of the families. Current study indicates that 60% of these families were attributable to <it>BRCA1 </it>mutations, while 26.7% of them were attributable to <it>BRCA2 </it>mutations. Results showed that four mutations were detected in the <it>BRCA1 </it>gene, while one mutation was detected in the <it>BRCA2 </it>gene. Asymptomatic relatives, 80(67%) out of total 120, were mutation carriers.</p> <p>Conclusions</p> <p><it>BRCA1 </it>and <it>BRCA2 </it>genes mutations are responsible for a significant proportion of breast cancer. <it>BRCA </it>mutations were found in individuals with and without family history.</p