Michael Cronin | PubMed Health

PubMed2006

Antisense delivery and protein knockdown within the intact central nervous system.

The ability to down regulate the expression of a specific protein within the intact central nervous system (CNS) is highly desirable from both a research and therapeutic perspective. Antisense has the potential to do this. However, problems of invasive antisense delivery methods and short half life of remain problematic. We overcome this by using Pluronic gel to provide a sustained delivery antisense oligodeoxynucleotides (ODN's) to the intact central nervous system and achieving rapid penetration throughout the spinal cord in 2-3 hours and significant knockdown of our target protein connexin 43 (Cx43) in 4-8 hours (recovering at 48-72 hours). Interestingly CY3-siRNA probes could not be detected penetrating the intact CNS and no knockdown the Cx43 was found. This approach with conventional ODNs could provide a faster and cheaper alternative to knockout mice in the investigation of the functions of specific proteins within the CNS and may also have therapeutic implications for drug discovery and development.

Animals↗

PubMed2004

Methods to increase the percentage of free fetal DNA recovered from the maternal circulation.

CONTEXT: Noninvasive prenatal diagnostic tests using free fetal DNA provide an alternative to invasive tests and their attendant risks; however, free fetal DNA exists in the maternal circulation at low percentages, which has hindered development of noninvasive tests. OBJECTIVE: To test the hypothesis that using formaldehyde to reduce cell lysis could increase the relative percentage of free fetal DNA in samples of maternal blood. DESIGN, SETTING, AND PATIENTS: The first phase of the study was conducted from January through February 2002 at a single US clinical site; 2 samples of blood were collected from each of 10 pregnant women, and the percentage of free fetal DNA in formaldehyde-treated and untreated samples was determined. The second phase of the study was conducted from March 2002 through May 2003, and measured the percentage of free fetal DNA in 69 formaldehyde-treated samples of maternal blood obtained from a network of 27 US clinical sites in 16 states. MAIN OUTCOME MEASURE: Percentage of free fetal DNA in samples of maternal blood. RESULTS: In the first phase of the study, the mean percentage of free fetal DNA in the untreated samples was 7.7% (range, 0.32%-40%), while the mean percentage of free fetal DNA in the formaldehyde-treated samples was 20.2% (range, 1.6%-40%) (P =.02 for difference). In the second phase, a median of 25% (range, 3.1% to >50%) free fetal DNA was obtained for the 69 formaldehyde-treated maternal blood samples. Approximately 59% of the samples in this study had 25% or greater fetal DNA, and only 16% of the samples had less than 10% fetal DNA. In addition, 27.5% of the samples in this study had 50% or greater fetal DNA. CONCLUSION: Addition of formaldehyde to maternal blood samples, coupled with careful processing protocols, increases the relative percentage of free fetal DNA, providing a foundation for development of noninvasive prenatal diagnostic tests to distinguish fetal DNA from maternal DNA in the maternal circulation.

Blood Specimen Collection↗

PubMed2004

Is the Charnley evolution working? A five-year outcome study.

Two hundred consecutive primary total hip arthroplasties (196 patients) carried out between January 1994 and May 1995 using the Elite Plus cemented femoral components (DePuy International, Leeds, UK) were enrolled in a prospective study. Fifteen patients were lost to follow-up. The patients were evaluated clinically using the Harris Hip Score (HHS) and radiographically. The mean HHS was raised from 39.3 preoperatively to 89.6 at 5 years. Radiologically the mean femoral subsidence was 1.40 mm at 5 years. The mean annual rate of re-operation was 0.2%. There were no revisions for aseptic loosening. In the present series, the Elite Plus hip arthroplasty has produced clinical and radiological results, which are comparable with the Charnley hip at five years.

Adult↗