Isolation and genetic analysis of pure cells from forensic biological mixtures: The precision of a digital approach.

Latest genotyping technologies allow to achieve a reliable genetic profile for the offender identification even from extremely minute biological evidence. The ultimate challenge occurs when genetic profiles need to be retrieved from a mixture, which is composed of biological material from two or more individuals. In this case, DNA profiling will often result in a complex genetic profile, which is then subject matter for statistical analysis. In principle, when more individuals contribute to a mixture with different biological fluids, their single genetic profiles can be obtained by separating the distinct cell types (e.g. epithelial cells, blood cells, sperm), prior to genotyping. Different approaches have been investigated for this purpose, such as fluorescent-activated cell sorting (FACS) or laser capture microdissection (LCM), but currently none of these methods can guarantee the complete separation of different type of cells present in a mixture. In other fields of application, such as oncology, DEPArray™ technology, an image-based, microfluidic digital sorter, has been widely proven to enable the separation of pure cells, with single-cell precision. This study investigates the applicability of DEPArray™ technology to forensic samples analysis, focusing on the resolution of the forensic mixture problem. For the first time, we report here the development of an application-specific DEPArray™ workflow enabling the detection and recovery of pure homogeneous cell pools from simulated blood/saliva and semen/saliva mixtures, providing full genetic match with genetic profiles of corresponding donors. In addition, we assess the performance of standard forensic methods for DNA quantitation and genotyping on low-count, DEPArray™-isolated cells, showing that pure, almost complete profiles can be obtained from as few as ten haploid cells. Finally, we explore the applicability in real casework samples, demonstrating that the described approach provides complete separation of cells with outstanding precision. In all examined cases, DEPArray™ technology proves to be a groundbreaking technology for the resolution of forensic biological mixtures, through the precise isolation of pure cells for an incontrovertible attribution of the obtained genetic profiles.

Dimensional and microbiological in vitro analysis of a dental implant locking taper connection.

The present study was carried out to compare the differences in contact, height and contact area between the implant-abutment interface and the implant-healing cap interface of an implant system featuring a locking tapered connection by using X-ray micro-tomography. It was also conducted to test in vitro whether the implant-healing cap tapered interface is capable of preventing bacterial leakage from the implant well to the external environment. The images of the samples, acquired by the X-ray micro-tomography, after being processed with a dedicated software, showed a greater contact height (CH) in the implant-abutment sample (3.57 mm) compared to the implant-healing cap sample (2.52 mm). This was also true for the contact area that was equal to 40.63 mm2 in the implant-abutment sample and 25.14 mm2 in the implant-healing cap sample. No bacteria were detected both in the nutrient of the test group and of the negative control after 24 h. An increased contact height and contact area in a tapered connection, between the implant and the abutment, have demonstrated to offer mechanical and biological advantages, in a implant-healing cap tapered connection. The major concern regards the microbiological aspects of this connection. The implant-healing cap tapered connection provides an hermetic barrier to microbial passage in vitro, even though such connection features lower contact height and contact area compared to the implant-abutment connection of the same implant system.

Primary gastric lymphoma: a review of 45 cases.

Primary gastric lymphoma accounts for about 2% of gastric neoplasms. The prognosis of patients affected with non-Hodgkin's gastric lymphoma appears better than for other lymphatic sites. In a retrospective study, the authors have analyzed 45 patients, by evaluating the histopathologic characteristics and relative prognostic factors. The main factors significantly influencing 5-yr survival are: serosal penetration (31.17% vs. 71.2%, P less than 0.05), regional lymph node involvement (53.07% vs. 68%), and clinical stage of disease (IE: 85.6%, IVE:10%, P less than 0.001). The histologic characteristics, the high or low grade of malignancy, and patient age can also be considered important prognostic factors, but not statistically significant in our series of cases. Comparison between overall survival and disease-free survival of patients in stages IE and IIE who underwent surgery alone, with those who had chemotherapy and/or radiotherapy after surgery shows a higher survival (85.6%) of the group who had combined treatments, even though this difference is not statistically significant.