Detection of clinically significant prostate cancer following initial omission of biopsy in multiparametric MRI era.

BACKGROUND: Multiparametric prostate MRI (mpMRI) is being increasingly adopted for work-up of prostate cancer. For patients selected to omit biopsy, we identified factors associated with repeat MRI, eventual prostate biopsy, and subsequent detection of clinically significant prostate cancer (csPCa, Grade Group ≥2). METHODS: We identified biopsy-naïve men presenting with PSA 2-20 ng/mL (March 2018-June 2021) undergoing initial mpMRI with PIRADS 1-3 lesions who were not selected for biopsy with ≥6 months follow-up. We examined factors associated with repeat mpMRI, progression to biopsy, and subsequent detection of csPCa with univariable and multivariable logistic regression. RESULTS: Of 1494 men, 31% (463/1494) did not pursue biopsy. PSA density (PSAD) ≤ 0.1, prostate health index (PHI) < 55, and PIRADS 1-2 were associated with omission of prostate biopsy. csPCa diagnosis-free survival was 97.6% (326/334) with median follow up of 23.1 months (IQR 15.1-34.6 months). Black race, PSA, PHI, PSA density, and PSA and PHI velocity were significant predictors of undergoing repeat mpMRI (15.6%, 52/334) and subsequent biopsy (8.4%, 28/334). 8 men were subsequently diagnosed with csPCa (N = 7 on prostate biopsy; N = 1 incidentally on holmium enucleation of prostate). All patients diagnosed with csPCa had PIRADS 4-5 on repeat mpMRI. CONCLUSIONS: The subsequent detection rate of csPCa among patients not initially biopsied after mpMRI was low at 2.4%. Decisions to omit biopsy after initial reassuring PHI, PSAD, and mpMRI appear safe with subsequent reassuring serum biomarkers and for cause mpMRI during follow-up.

Targeting Duchenne muscular dystrophy by skipping DMD exon 45 with base editors.

Duchenne muscular dystrophy is an X-linked monogenic disease caused by mutations in the dystrophin gene (DMD) characterized by progressive muscle weakness, leading to loss of ambulation and decreased life expectancy. Since the current standard of care for Duchenne muscular dystrophy is to merely treat symptoms, there is a dire need for treatment modalities that can correct the underlying genetic mutations. While several gene replacement therapies are being explored in clinical trials, one emerging approach that can directly correct mutations in genomic DNA is base editing. We have recently developed CRISPR-SKIP, a base editing strategy to induce permanent exon skipping by introducing C > T or A > G mutations at splice acceptors in genomic DNA, which can be used therapeutically to recover dystrophin expression when a genomic deletion leads to an out-of-frame DMD transcript. We now demonstrate that CRISPR-SKIP can be adapted to correct some forms of Duchenne muscular dystrophy by disrupting the splice acceptor in human DMD exon 45 with high efficiency, which enables open reading frame recovery and restoration of dystrophin expression. We also demonstrate that AAV-delivered split-intein base editors edit the splice acceptor of DMD exon 45 in cultured human cells and in vivo, highlighting the therapeutic potential of this strategy.

Optimizing detection of clinically significant prostate cancer through nomograms incorporating mri, clinical features, and advanced serum biomarkers in biopsy naïve men.

PURPOSE: To develop nomograms that predict the detection of clinically significant prostate cancer (csPCa, defined as ≥GG2 [Grade Group 2]) at diagnostic biopsy based on multiparametric prostate MRI (mpMRI), serum biomarkers, and patient clinicodemographic features. MATERIALS AND METHODS: Nomograms were developed from a cohort of biopsy-naïve men presenting to our 11-hospital system with prostate specific antigen (PSA) of 2-20 ng/mL who underwent pre-biopsy mpMRI from March 2018-June 2021 (n = 1494). The outcomes were the presence of csPCa and high-grade prostate cancer (defined as ≥GG3 prostate cancer). Using significant variables on multivariable logistic regression, individual nomograms were developed for men with total PSA, % free PSA, or prostate health index (PHI) when available. The nomograms were both internally validated and evaluated in an independent cohort of 366 men presenting to our hospital system from July 2021-February 2022. RESULTS: 1031 of 1494 men (69%) underwent biopsy after initial evaluation with mpMRI, 493 (47.8%) of whom were found to have ≥GG2 PCa, and 271 (26.3%) were found to have ≥GG3 PCa. Age, race, highest PIRADS score, prostate health index when available, % free PSA when available, and PSA density were significant predictors of ≥GG2 and ≥GG3 PCa on multivariable analysis and were used for nomogram generation. Accuracy of nomograms in both the training cohort and independent cohort were high, with areas under the curves (AUC) of ≥0.885 in the training cohort and ≥0.896 in the independent validation cohort. In our independent validation cohort, our model for ≥GG2 prostate cancer with PHI saved 39.1% of biopsies (143/366) while only missing 0.8% of csPCa (1/124) with a biopsy threshold of 20% probability of csPCa. CONCLUSIONS: Here we developed nomograms combining serum testing and mpMRI to help clinicians risk stratify patients with elevated PSA of 2-20 ng/mL who are being considered for biopsy. Our nomograms are available at https://rossnm1.shinyapps.io/MynMRIskCalculator/ to aid with biopsy decisions.

Remote Laboratory Exercise to Develop Micropipetting Skills.

The rapid spread of COVID-19 has fundamentally transformed our educational system. The need to protect both students and instructors from exposure to viral infection has required the implementation of remote instructional models. Although this alternative delivery approach can be successfully implemented to teach the theoretical foundations of multiple disciplines, teaching technical skills poses a major challenge, particularly in various biology fields, where observation of biological safety guidelines and the high cost of analytical equipment represent major impediments for remote instruction. To overcome this problem, we have developed a laboratory exercise to teach students how to use micropipettes that can be completed remotely using materials that can be purchased at a fraction of the cost of the instructional equipment normally reserved for in-person instruction. Our evaluation of the effectiveness of this remote lab indicated that the majority of students who participated in a survey believed they attained the learning objectives and felt confident in their lab technique after completing the exercises. The simplicity, relatively low cost, and effectiveness of this approach makes it highly adaptable for other classrooms and educational settings.