Stress analysis of an artificial temporal mandibular joint

To design a temporal mandibular joint (TMJ), the designer should pay attention to the range of movement in the joint, the strength of the joint, and the size of the implant should conform, so that it does not hamper facial configuration. As a number of designs are available, in this study we have considered one of the most common and widely used implants for analysis. The main objective of this study is to examine the stress-strain behavior at the implant and what is happening at the implant bone interface. We have also examined whether implant material can be replaced by UHMWPE (ultra high molecular weight polyethylene) instead of titanium or Co-Cr-Mo alloy. Whether the change of positions of the screw used for fixation has any effect or not, we have modeled it considering actual shape and size, then divided it into number finite elements by using a FEM package. An appropriate surgical construct was modeled and loaded and studied for different parameters. We have shown that the metallic prostheses are good from a stress-strain point of view and UHMWPE cannot be used as such.     

Three discrete areas within the chromosomal 8p21.3-23 region are associated with the development of breast carcinoma of Indian patients

Deletion in the 22.9 -Mb chromosomal (chr.) 8p21.3-23 region has been shown to be necessary for the development of breast carcinoma (CaBr). In this study, we have attempted to detect the minimal deleted region(s) in the chr.8p21.3-23 region in 62 primary breast lesions having 56 CaBr tumors and six other breast lesions of Indian patients using 15 microsatellite markers. The loss of heterozygosity (LOH) was observed for at least one marker in 96.4% (54/56) of the CaBr samples. Three discrete minimal deleted regions with high frequencies of LOH (39-65%) were identified in the chromosomal 8p23.1-23.2 (D1), 8p23.1 (D2) and 8p 21.3-22 (D3) regions within 2.03, 0.41, 2.47 Mb, respectively. No significant correlation was observed with the high deleted regions and the different clinicopathological parameters. Interestingly, 51.8% (29/56) CaBr samples showed either loss of chr.8p or interstitial deletions in this arm, indicating the importance of chr.8p in the development of CaBr. The pattern of allelic loss in the bilateral lesions had indicated that the lesions were clonal in origin and probably the deletion in the D3 region was the early event among the D1-D3 regions. Thus, our data have indicated that the D1-D3 regions could harbor candidate tumor suppressor gene(s) (TSGs) associated with the development of CaBr.     

Anti-human CTLA-4 monoclonal antibody promotes T-cell expansion and immunity in a hu-PBL-SCID model: a new method for preclinical screening of costimulatory monoclonal antibodies

When adopting basic principles learned in mice to clinical application in humans, it is often difficult to distinguish whether a "translation" fails because of an invalid target in the human disease or because the therapeutic agents are not optimal for the human target. It is, therefore, desirable to develop preclinical models to optimize therapies for human targets using in vivo settings. Although anti-mouse CTLA-4 antibodies are known to enhance immune responses in vivo, their effect on T-cell activation in vitro ranges from enhancement to inhibition. Here we use the hu-PBL-SCID mouse model of Epstein-Barr virus (EBV)-associated lymphoma development to screen a panel of anti-human CTLA-4 monoclonal antibodies (mAbs) for their effect on human lymphocytes in an in vivo "humanized" environment. We report significant heterogeneity of anti-human CTLA-4 mAbs in enhancing the expansion of human T cells in mice, and this heterogeneity cannot be attributed to immunoglobulin isotypes or affinity for CTLA-4. These data validate the development of additional screening tools, such as the one described, to further characterize functional activity of antihuman antibodies before proceeding with clinical translation to human studies.     

Deletion in chromosome 11 and Bcl-1/Cyclin D1 alterations are independently associated with the development of uterine cervical carcinoma

Purpose The aim of this study was to understand whether there is any association between specific deleted regions in chromosome 11 (chr.11) and alteration (amplification/rearrangement) of Bcl-1/Cyclin D1 locus, located at 11q13, in uterine cervical carcinoma (CA-CX).Methods The deletion mapping of chr.11 was studied using 17 highly polymorphic microsatellite markers in 65 primary uterine cervical lesions. The Bcl-1/Cyclin D1 alterations were analyzed by Southern blot and/or polymerase chain reaction (PCR) method in respective cervical lesions.Results Chr.11 deletion was found to be significantly associated with progression of CA-CX. High frequency (48–65%) of deletion was found in 11p15.5 (D1), 11q22.3–23.1(D2), and 11q23.3–24.1(D3) regions and significant association was seen among deletions in D2 and D3 regions. Bcl-1/Cyclin D1 locus alteration was observed in overall 27% cervical lesions. Co-amplification of Bcl-1/Cyclin D1 locus was seen in 10% samples. However, no association was found between the deleted regions and Bcl-1/Cyclin D1 locus alterations.Conclusions Our study suggests that there is no co-operativity between the deleted regions (D1- D3) in chr.11 and Bcl-1/Cyclin D1 alterations, but these alterations may provide cumulative effect in progression of the tumor. The D1–D3 regions may harbor candidate tumor suppressor gene(s) (TSGs) associated with the development of CA-CX.Financial support for this work was provided by grant [no. 27 (0111)/00/EMR-II] from CSIR, Govt. of India to C.K. Panda and CSIR -JRF/NET Fellowship grant (no. 9/30 (026)/2002- EMR-I) to R.K. Singh     

Comparison of Custom Capture for Targeted Next-Generation DNA Sequencing

Targeted, capture-based DNA sequencing is a cost-effective method to focus sequencing on a coding region or other customized region of the genome. There are multiple targeted sequencing methods available, but none has been systematically investigated and compared. We evaluated four commercially available custom-targeted DNA technologies for next-generation sequencing with respect to on-target sequencing, uniformity, and ability to detect single-nucleotide variations (SNVs) and copy number variations. The technologies that used sonication for DNA fragmentation displayed impressive uniformity of capture, whereas the others had shorter preparation times, but sacrificed uniformity. One of those technologies, which uses transposase for DNA fragmentation, has a drawback requiring sample pooling, and the last one, which uses restriction enzymes, has a limitation depending on restriction enzyme digest sites. Although all technologies displayed some level of concordance for calling SNVs, the technologies that require restriction enzymes or transposase missed several SNVs largely because of the lack of coverage. All technologies performed well for copy number variation calling when compared to single-nucleotide polymorphism arrays. These results enable laboratories to compare these methods to make informed decisions for their intended applications.Next-generation sequencing technologies have enabled cancer genomics discovery by providing a high-throughput and cost-effective strategy to sequence thousands of cancer genomes.¹ Next-generation sequencing has helped identify novel genomic alterations in cancer, including, but not limited to, single-nucleotide variations (SNVs), copy number variations (CNVs), and gene fusions that may serve as predictive biomarkers for matching patients to targeted therapies in trials.² Although whole genome and exome sequencing enables discovery of novel genomic alterations, clinical-grade applications must consider constraints, including cost per patient, time to results, and depth of coverage. Consequently, clinical implementation of sequencing has focused on customized sequencing of actionable genes, exons, or regions.^3,4 A targeted-capture next-generation sequencing strategy is clinically pragmatic, because it is scalable, is economical, and allows for deeper sequencing coverage compared to whole genome or whole exome approaches. Thus, many laboratories are using or considering custom capture gene panels for diverse applications, including discovery, validation testing, or clinical-grade assay development.^3,5–8 To this end, we compared the proficiency of four methods to capture and sequence a custom gene panel.Practical considerations for targeted gene sequencing include cost of sequencing and wanted depth of coverage. Thus, ideal methods provide high on-target and uniform sequencing. Amplicon-based assays for cancer gene hotspots offer high on-target specificity, but can only cover a limited scope of regions.² Beyond such assays in cancer,^5,6,8 hybridization-based capture strategies can focus on larger regions of interest and additional types of alteration, such as CNVs.^3,7,9Although earlier studies compared the strengths and weaknesses of three methods for whole exome capture using in-solution hybridization,^10–14 several new clinically oriented methods have been developed that offer rapid, simplified sample preparation and lower requirements for DNA input. Herein, we describe a comprehensive comparison of four DNA capture technologies for a panel of 257 cancer-related genes. We evaluated the ability of four methods for each to capture targeted regions in 16 samples, including six pairs of tumor and normal tissue and four cell lines, in terms of alignment rate, sequencing uniformity, GC content bias, SNV concordance, and CNV-calling ability.