Tuning cellular response by modular design of bioactive domains in collagen.

Collagen's ability to direct cellular behavior suggests that redesigning it at the molecular level could enable manipulation of cells residing in an engineered microenvironment. However, the fabrication of full-length collagen mimics of specified sequence de novo has been elusive, and applications still rely on material from native tissues. Using a bottom-up strategy, we synthesized modular genes and expressed recombinant human collagen variants in Saccharomyces cerevisiae.

Early detection of clinically significant prostate cancer at diagnosis: a prospective study using a novel panel of TMPRSS2:ETS fusion gene markers.

We explore noninvasive clinical applications of multiple disease-specific fusion markers recently discovered in prostate cancer to predict the risk of cancer occurrence and aggressiveness at diagnosis. A total of 92 men who were prostate-specific antigen (PSA) screened and scheduled for diagnostic biopsy were enrolled for this study. Prospectively collected urine was blind coded for laboratory tests.

Simultaneous quantification of mitochondrial DNA damage and copy number in circulating blood: a sensitive approach to systemic oxidative stress.

Systemic oxidative stress is associated with a wide range of pathological conditions. Oxidative DNA damage is frequently measured in circulating lymphocytes. Mitochondrial DNA (mtDNA) is known to be more sensitive to oxidative damage than nuclear DNA but is rarely used for direct measurement of DNA damage in clinical studies.

RNA preservation in decalcified cochlear samples.

Hypothesis: Decalcification of cochlear samples in Morse's solution after methacarn fixation provides greater RNA quantification and morphologic preservation of cochlear structures as compared with EDTA and formic acid decalcifying solutions after methacarn fixation.

Background: A variety of fixatives and decalcifying agents can fragment or chemically alter RNA in samples inhibiting their isolation and quantification. Morphologic alterations can also be observed in light microscopy analyses.

Influence of microsurgical varicocelectomy on human sperm mitochondrial DNA copy number: a pilot study.

Background: There is good evidence to show that varicocele repair can improve conventional sperm parameters, as well as, sperm DNA integrity, in infertile men with a clinical varicocele.

Objective: To examine the effect of varicocelectomy on sperm quality, specifically, sperm nuclear chromatin integrity and sperm mitochondrial DNA (mtDNA) copy number.

Design, Setting, And Participants: A prospective study done between March 2007 and January 2008.

Mitochondrial DNA damage is sensitive to exogenous H(2)O(2) but independent of cellular ROS production in prostate cancer cells.

Intrinsic oxidative stress through enhanced production of reactive oxygen species (ROS) in prostate and other cancers may contribute to cancer progression due to its stimulating effect on cancer growth. In this study, we investigate differential responses to exogenous oxidative stimuli between aggressive prostate cancer and normal cell lines and explore potential mechanisms through interactions between cytotoxicity, cellular ROS production and oxidative DNA damage. The circular, multi-copy mitochondrial DNA (mtDNA) is used as a sensitive surrogate to oxidative DNA damage.

Recombinant human collagen and biomimetic variants using a de novo gene optimized for modular assembly.

A collagen-mimetic polymer that can be easily engineered with specific cell-responsive and mechanical properties would be of significant interest for fundamental cell-matrix studies and applications in regenerative medicine. However, oligonucleotide-based synthesis of full-length collagen has been encumbered by the characteristic glycine-X-Y sequence repetition, which promotes mismatched oligonucleotide hybridizations during de novo gene assembly. In this work, we report a novel, modular synthesis strategy that yields full-length human collagen III and specifically defined variants.

Measuring mtDNA damage using a supercoiling-sensitive qPCR approach.

Compromised mitochondrial DNA structural integrity can have functional consequences for mitochondrial gene expression and replication leading to metabolic and degenerative diseases, aging, and cancer. Gel electrophoresis coupled with Southern blot and probe hybridization and long PCR are established methods for detecting mtDNA damage. But each has its respective shortcomings: gel electrophoresis is at best semi-quantitative and long PCR does not offer information on the structure.