COVID-19 Symptoms and Duration of Rapid Antigen Test Positivity at a Community Testing and Surveillance Site During Pre-Delta, Delta, and Omicron BA.1 Periods.

Importance: Characterizing the clinical symptoms and evolution of community-based SARS-CoV-2 infections may inform health practitioners and public health officials in a rapidly changing landscape of population immunity and viral variants. Objectives: To compare COVID-19 symptoms among people testing positive with a rapid antigen test (RAT) during the Omicron BA.1 variant period (December 1, 2021, to January 30, 2022) with the pre-Delta (January 10 to May 31, 2021) and Delta (June 1 to November 30, 2021) variant periods and to assess the duration of RAT positivity during the Omicron BA.1 surge. Design, Setting, and Participants: This cross-sectional study was conducted from January 10, 2021, to January 31, 2022, at a walk-up community COVID-19 testing site in San Francisco, California. Participants included children and adults seeking COVID-19 testing with an RAT, regardless of age, vaccine status, or symptoms. Main Outcomes and Measures: Fisher exact tests or χ2 tests were used to compare COVID-19 symptoms during the Omicron BA.1 period with the pre-Delta and Delta periods for vaccination status and age group. Among people returning for repeated testing during the Omicron period, the proportion with a positive RAT between 4 and 14 days from symptom onset or since first positive test if asymptomatic was estimated. Results: Among 63 277 persons tested (median [IQR] age, 32 [21-44] years, with 12.0% younger than 12 years; 52.0% women; and 68.5% Latinx), a total of 18 301 people (28.9%) reported symptoms, of whom 4565 (24.9%) tested positive for COVID-19. During the Omicron BA.1 period, 3032 of 7283 symptomatic participants (41.6%) tested positive, and the numbers of these reporting cough and sore throat were higher than during pre-Delta and Delta periods (cough: 2044 [67.4%] vs 546 [51.3%] of 1065 participants, P < .001 for pre-Delta, and 281 [60.0%] of 468 participants, P = .002, for Delta; sore throat: 1316 [43.4%] vs 315 [29.6%] of 1065 participants, P < .001 for pre-Delta, and 136 [29.1%] of 468 participants, P < .001, for Delta). Compared with the 1065 patients with positive test results in the pre-Delta period, congestion among the 3032 with positive results during the Omicron BA.1 period was more common (1177 [38.8%] vs 294 [27.6%] participants, P < .001), and loss of taste or smell (160 [5.3%] vs 183 [17.2%] participants, P < .001) and fever (921 [30.4%] vs 369 [34.7%] participants, P = .01) were less common. In addition, during the Omicron BA.1 period, fever was less common among the people with positive test results who had received a vaccine booster compared with those with positive test results who were unvaccinated (97 [22.5%] of 432 vs 42 [36.2%] of 116 participants, P = .003), and fever and myalgia were less common among participants who had received a booster compared with those with positive results who had received only a primary series (fever: 97 [22.5%] of 432 vs 559 [32.8%] of 1705 participants, P < .001; myalgia: 115 [26.6%] of 432 vs 580 [34.0%] of 1705 participants, P = .003). During the Omicron BA.1 period, 5 days after symptom onset, 507 of 1613 people (31.1%) with COVID-19 stated that their symptoms were similar, and 95 people (5.9%) reported worsening symptoms. Among people testing positive, 80.2% of participants who were symptomatic and retested remained positive 5 days after symptom onset. Conclusions and Relevance: In this cross-sectional study, COVID-19 upper respiratory tract symptoms were more commonly reported during the Omicron BA.1 period than during the pre-Delta and Delta periods, with differences by vaccination status. Rapid antigen test positivity remained high 5 days after symptom onset, supporting guidelines requiring a negative test to inform the length of the isolation period.

A deep dive into the morphokinetics and ploidy of low-quality blastocysts.

Objective: To describe morphokinetic parameters and ploidy among low-quality blastocysts not meeting the criteria for clinical use. Design: Prospective cohort study. Setting: Academic medical center. Patients: Two hundred patients undergoing in vitro fertilization between February 2018 and November 2019. Interventions: All embryos were cultured in a time-lapse incubator. All expanded blastocysts underwent preimplantation genetic testing for aneuploidy using next-generation sequencing. Main Outcome Measures: Static blastocyst morphology grading; morphokinetic parameters, including time to each cell division (2-cell formation to 8-cell formation); time to morula formation; time to the start of blastulation; time to blastocyst formation; and preimplantation genetic testing for aneuploidy results. Results: A total of 1,306 embryos progressed to the expanded blastocyst stage; of these, 935 embryos met the criteria for clinical use and were designated as high quality, whereas 371 embryos were graded as low quality and did not meet the criteria for use. In morphokinetic evaluation, low-quality embryos developed more quickly to 5-cell formation (t5) 48.4 [42.4-48.7) vs 50.2 [46.3-50.1] hours, but progressed more slowly thereafter with tM 91.5 [85.9-92.3] vs 88.3 [82.1-88.3] and tB 114.0 [106.4-113.9] vs 106.9 [101.3-107.4] hours. Among the low-quality embryos, 75.5% were aneuploid, 22.4% were euploid, and 2.2% had undetermined chromosome copy number results. Morphokinetic parameters did not differ between the euploid and aneuploid low-quality embryos. Conclusions: Morphokinetic analysis did not distinguish between euploid and aneuploid low-quality embryos.

Microfluidic preparation of spermatozoa for ICSI produces similar embryo quality to density-gradient centrifugation: a pragmatic, randomized controlled trial.

STUDY QUESTION: Does processing of spermatozoa for IVF with ICSI by a microfluidic sperm separation device improve embryo quality compared with density-gradient centrifugation? SUMMARY ANSWER: Patients randomized to microfluidic sperm preparation had similar cleavage- and blastocyst-stage embryo quality and clinical and ongoing pregnancy rates to those who underwent standard sperm processing for IVF with ICSI. WHAT IS KNOWN ALREADY: Microfluidic sperm preparation can isolate spermatozoa for clinical use with minimal DNA fragmentation but with unclear impact on clinical outcomes. STUDY DESIGN, SIZE, DURATION: A prospective randomized controlled trial of 386 patients planning IVF from June 2017 through September 2021 was carried out. PARTICIPANTS/MATERIALS, SETTING, METHODS: One hundred and ninety-two patients were allocated to sperm processing with a microfluidic sperm separation device for ICSI, while 194 patients were allocated to clinical standard density-gradient centrifugation (control) at an academic medical centre. MAIN RESULTS AND THE ROLE OF CHANCE: In an intention to treat analysis, there were no differences in high-quality cleavage-stage embryo fraction [66.0 (25.8)% control versus 68.0 (30.3) microfluidic sperm preparation, P = 0.541, absolute difference -2.0, 95% CI (-8.5, 4.5)], or high-quality blastocyst fraction [37.4 (25.4) control versus 37.4 (26.2) microfluidic sperm preparation, P = 0.985, absolute difference -0.6 95% CI (-6, 5.9)] between groups. There were no differences in the clinical pregnancy or ongoing pregnancy rates between groups. LIMITATIONS, REASONS FOR CAUTION: The population studied was inclusive and did not attempt to isolate male factor infertility cases or patients with a history of elevated sperm DNA fragmentation. WIDER IMPLICATIONS OF THE FINDINGS: Microfluidic sperm separation performs similarly to density-gradient centrifugation in sperm preparation for IVF in an unselected population. STUDY FUNDING/COMPETING INTEREST(S): No external funding to declare. M.P.R. is a member of the Clinical Advisory Board for ZyMot® Fertility, Inc. TRIAL REGISTRATION NUMBER: NCT03085433. TRIAL REGISTRATION DATE: 21 March 2017. DATE OF FIRST PATIENT'S ENROLLMENT: 16 June 2017.

Integrating Rapid Diabetes Screening Into a Latinx Focused Community-Based Low-Barrier COVID-19 Testing Program.

Importance: Community-based COVID-19 testing and vaccination programs play a crucial role in mitigating racial and ethnic disparities in COVID-19 service delivery. They also represent a platform that can be leveraged to expand access to testing for chronic diseases, including diabetes, that disproportionately affect the Latinx community and other marginalized communities. Objective: To evaluate outcomes associated with a diabetes testing strategy designed to reach low-income Latinx persons by leveraging COVID-19 testing infrastructure and community trust developed during the COVID-19 pandemic. Design, Setting, and Participants: This health care improvement study was conducted from August 1 to October 5, 2021, at an outdoor, community-based COVID-19 testing site at a transport hub in the Mission Neighborhood in San Francisco, California. Because the program was designed to expand access to diabetes screening to the local community, all individuals presenting for on-site testing were eligible. Data were analyzed in November 2021. Interventions: Integration of rapid, point-of-care hemoglobin A1c screening as a testing option in an existing low-barrier COVID-19 testing program. Main Outcomes and Measures: Evaluation was guided by the Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework and utilized programmatic data and structured surveys among clients and staff. Results: Of 6631 individuals tested (median [IQR] age 39.3 [29.7-51.3] years; 3417 [52.3%] female, 4348 [65.6%] Latinx), 923 (13.9%) underwent hemoglobin A1c testing with or without COVID-19 testing and 5708 (86.1%) underwent COVID-19 testing only. Individuals tested for diabetes were more likely to be Latinx (763 of 923 individuals [82.7%] who underwent testing were Latinx vs 3585 of 5708 [62.8%] not undergoing testing), have an annual household income of less than $50 000 (450 individuals [81.2%] vs 2409 individuals [66.0%]), and not have health insurance (381 individuals [47.2%] vs 1858 individuals [39.9%]), and 206 (48.0%) had never tested for diabetes before. Overall, 313 (33.9%) and 113 (12.2%) individuals had prediabetes and diabetes, respectively; only 141 of 354 of these individuals (39.8%) had a primary care clinician whom they had seen in the prior 12 months, which was lower among Latinx individuals (113 of 307 individuals [36.8%] vs 28 of 47 [59.6%]). Acceptability of the rapid testing program was high-98% were satisfied with their visit and 96% said they would return for future services; key factors underpinning acceptability included friendly staff, efficiency, and a convenient location. Conclusions and Relevance: In this health care improvement study conducted within an existing community-based COVID-19 testing program, integrating rapid testing for diabetes was feasible, reached low-income Latinx individuals, and identified many persons with prediabetes and diabetes, most of whom lacked access to services in formal health care settings. Leveraging pandemic-related public health responses represents an important opportunity for engaging socioeconomically disadvantaged populations into care for diabetes.

Comparison of SARS-CoV-2 Reverse Transcriptase Polymerase Chain Reaction and BinaxNOW Rapid Antigen Tests at a Community Site During an Omicron Surge : A Cross-Sectional Study.

BACKGROUND: SARS-CoV-2 rapid antigen tests are an important public health tool. OBJECTIVE: To evaluate field performance of the BinaxNOW rapid antigen test (Abbott) compared with reverse transcriptase polymerase chain reaction (RT-PCR) for detecting infection with the Omicron variant of SARS-CoV-2. DESIGN: Cross-sectional surveillance study. SETTING: Free, walk-up, outdoor, urban community testing and vaccine site led by Unidos en Salud, serving a predominantly Latinx community highly impacted by COVID-19. PARTICIPANTS: Persons seeking COVID-19 testing in January 2022. MEASUREMENTS: Simultaneous BinaxNOW and RT-PCR from nasal, cheek, and throat swabs, including cycle threshold (Ct) measures; a lower Ct value is a surrogate for higher amounts of virus. RESULTS: Among 731 persons tested with nasal swabs, there were 296 (40.5%) positive results on RT-PCR; 98.9% were the Omicron variant. BinaxNOW detected 95.2% (95% CI, 91% to 98%) of persons who tested positive on RT-PCR with a Ct value below 30, 82.1% (CI, 77% to 87%) of those who tested positive on RT-PCR with a Ct value below 35, and 65.2% (CI, 60% to 71%) of all who were positive on RT-PCR. Among 75 persons with simultaneous nasal and cheek swabs, BinaxNOW using a cheek swab failed to detect 91% (20 of 22) of specimens that were positive on BinaxNOW with a nasal swab. Among persons with simultaneous nasal and throat swabs who were positive on RT-PCR with a Ct value below 30, 42 of 49 (85.7%) were detected by nasal BinaxNOW, 23 of 49 (46.9%) by throat BinaxNOW, and 44 of 49 (89.8%) by either. LIMITATION: Participants were a cross-sectional sample from a community-based sentinel surveillance site, precluding study of viral or symptom dynamics. CONCLUSION: BinaxNOW detected persons with high SARS-CoV-2 levels during the Omicron surge, enabling rapid responses to positive test results. Cheek or throat swabs should not replace nasal swabs. As currently recommended, high-risk persons with an initial negative BinaxNOW result should have repeated testing. PRIMARY FUNDING SOURCE: University of California, San Francisco.

Aneuploidy rates and morphokinetic parameters of embryos cultured in distinct culture media: a sibling oocyte study.

STUDY QUESTION: Do embryos from sibling oocytes assigned to distinct single-step media culture systems demonstrate differences in early embryo development, morphokinectics or aneuploidy rates? SUMMARY ANSWER: Embryo quality, morphokinetic parameters and aneuploidy rates from trophectoderm biopsy were similar between sibling embryos cultured in distinct media systems from the time of gamete isolation. WHAT IS KNOWN ALREADY: Studies on the effect of commercially available embryo culture media systems have demonstrated inconsistent impact on human embryonic development, morphokinetics, aneuploidy rates and clinical outcomes. In addition, these studies have been primarily randomized at the level of the embryo or the patient to culture media. STUDY DESIGN, SIZE, DURATION: Prospective sibling oocyte cohort derived from 200 subjects undergoing IVF at a tertiary academic medical center between February 2018 and November 2019. PARTICIPANTS/MATERIALS, SETTING, METHODS: Sibling oocytes were allocated to Global® or SAGE® media system based upon laterality of ovary from which they were retrieved. All embryos were cultured in a time-lapse incubator. Blastocysts underwent trophectoderm biopsy for preimplantation genetic testing for aneuploidy using next-generation sequencing. MAIN RESULTS AND THE ROLE OF CHANCE: One hundred twenty-seven subjects (n = 127) had paired blastocysts for biopsy in each culture media system. There was no difference in top quality blastocyst formation (47.1 ± 31.0 vs 48.1 ± 27.2%; P = 0.87) nor aneuploidy rate (62.3 ± 34.0 vs 56.1 ± 34.4%; P = 0.07) for sibling embryos cultured in Global versus SAGE media system. Embryo morphokinetic parameters including time to each cell division from two cells (t2) to eight cells (t8), time to morula stage (tM), time to blastocele formation (tSB), time to fully formed blastocyst (tB) and time to expansion of the blastocyst (tEB) were similar between paired blastocysts from each culture media system. LIMITATIONS, REASONS FOR CAUTION: Pregnancy outcomes and offspring health data were not available for analysis. WIDER IMPLICATIONS OF THE FINDINGS: Commercially available culture media may not have a differential impact on embryo development and blastocyst aneuploidy rate when patient and stimulation-related factors are held constant. STUDY FUNDING/COMPETING INTEREST(S): There was no external funding for this study. C.H. is owner of a consultancy company, IVF Professionals, Chief Scientific Officer at Apricity, Executive Director at TMRW and co-owner and shareholder of Aria Fertility. She has received speaker fees, consulting fees and travel support from Cooper Surgical and Vitrolife. J.B. is an employee and shareholder of vitrolife. TRIAL REGISTRATION NUMBER: N/A.

A multi-component, community-based strategy to facilitate COVID-19 vaccine uptake among Latinx populations: From theory to practice.

BACKGROUND: COVID-19 vaccine coverage in the Latinx community depends on delivery systems that overcome barriers such as institutional distrust, misinformation, and access to care. We hypothesized that a community-centered vaccination strategy that included mobilization, vaccination, and "activation" components could successfully reach an underserved Latinx population, utilizing its social networks to boost vaccination coverage. METHODS: Our community-academic-public health partnership, "Unidos en Salud," utilized a theory-informed approach to design our "Motivate, Vaccinate, and Activate" COVID-19 vaccination strategy. Our strategy's design was guided by the PRECEDE Model and sought to address and overcome predisposing, enabling, and reinforcing barriers to COVID-19 vaccination faced by Latinx individuals in San Francisco. We evaluated our prototype outdoor, "neighborhood" vaccination program located in a central commercial and transport hub in the Mission District in San Francisco, using the Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework during a 16-week period from February 1, 2021 to May 19, 2021. Programmatic data, city-wide COVID-19 surveillance data, and a survey conducted between May 2, 2021 and May 19, 2021 among 997 vaccinated clients ≥16 years old were used in the evaluation. RESULTS: There were 20,792 COVID-19 vaccinations administered at the neighborhood site during the 16-week evaluation period. Vaccine recipients had a median age of 43 (IQR 32-56) years, 53.9% were male and 70.5% were Latinx, 14.1% white, 7.7% Asian, 2.4% Black, and 5.3% other. Latinx vaccinated clients were substantially more likely than non-Latinx clients to have an annual household income of less than $50,000 a year (76.1% vs. 33.5%), be a first-generation immigrant (60.2% vs. 30.1%), not have health insurance (47.3% vs. 16.0%), and not have access to primary care provider (62.4% vs. 36.2%). The most frequently reported reasons for choosing vaccination at the site were its neighborhood location (28.6%), easy and convenient scheduling (26.9%) and recommendation by someone they trusted (18.1%); approximately 99% reported having an overall positive experience, regardless of ethnicity. Notably, 58.3% of clients reported that they were able to get vaccinated earlier because of the neighborhood vaccination site, 98.4% of clients completed both vaccine doses, and 90.7% said that they were more likely to recommend COVID-19 vaccination to family and friends after their experience; these findings did not substantially differ according to ethnicity. There were 40.3% of vaccinated clients who said they still knew at least one unvaccinated person (64.6% knew ≥3). Among clients who received both vaccine doses (n = 729), 91.0% said that after their vaccination experience, they had personally reached out to at least one unvaccinated person they knew (61.6% reached out to ≥3) to recommend getting vaccinated; 83.0% of clients reported that one or more friends, and/or family members got vaccinated as a result of their outreach, including 18.9% who reported 6 or more persons got vaccinated as a result of their influence. CONCLUSIONS: A multi-component, "Motivate, Vaccinate, and Activate" community-based strategy addressing barriers to COVID-19 vaccination for the Latinx population reached the intended population, and vaccinated individuals served as ambassadors to recruit other friends and family members to get vaccinated.

Concomitant tamoxifen or letrozole for optimal oocyte yield during fertility preservation for breast cancer: the TAmoxifen or Letrozole in Estrogen Sensitive tumors (TALES) randomized clinical trial.

PURPOSE: To determine whether concomitant tamoxifen 20 mg with gonadotropins (tamoxifen-gonadotropin) versus letrozole 5 mg with gonadotropins (letrozole-gonadotropin) affects mature oocyte yield. METHODS: Open-label, single-institution, randomized trial. Inclusion criteria included the following: females, ages 18-44 years old, with new diagnosis of non-metastatic breast cancer, who were undergoing fertility preservation with either oocyte or embryo cryopreservation. Those with estrogen-receptor-positive (ER+) breast cancer were randomized to tamoxifen-gonadotropin or letrozole-gonadotropin. Another group with estrogen-receptor-negative (ER-) breast cancer was recruited, as a prospectively collected comparison arm who took neither letrozole nor tamoxifen (gonadotropin only). The primary outcome was the number of mature oocytes obtained from the cycle. The randomized groups were powered to detect a difference of three or more mature oocytes. RESULTS: Forty-five patients were randomized to tamoxifen-gonadotropin and fifty-one to letrozole-gonadotropin. Thirty-eight patients completed gonadotropin only. Age, antral follicle count, and body mass index were similar between the randomized groups. Our primary outcome of mature oocyte yield was similar between the tamoxifen-gonadotropin and letrozole-gonadotropin groups (12±8.6 vs. 11.6±7.5, p=0.81, 95%CI of difference =-2.9 to 3.7). In a pre-specified secondary comparison, mature oocyte yield was also similar with tamoxifen-gonadotropin or letrozole-gonadotropin versus gonadotropin only (12±8.6 vs. 11.6±7.5 vs. 12.4±7.2). There were no serious adverse events in any of the groups. CONCLUSIONS: Tamoxifen-gonadotropin and letrozole-gonadotropin produced a similar number of mature oocytes. Women who received either tamoxifen-gonadotropin or letrozole-gonadotropin had a similar number of oocytes to the gonadotropin-only group. TRIAL REGISTRATION: NCT03011684 (retrospectively registered 1/5/2017, after 9% enrolled).

Multi-chorionic pregnancies following single embryo transfer at the blastocyst stage: a case series and review of the literature.

OBJECTIVE: To report cases of in vitro fertilization-frozen embryo transfer (IVF-FET) with single blastocyst transfer resulting in di- or tri-chorionic pregnancies, and to review the literature on monozygotic, multi-chorionic pregnancies originating at the blastocyst stage. DESIGN: Retrospective case series and literature review. MATERIALS AND METHODS: All in vitro fertilization cycles (fresh, frozen, autologous, and donor oocyte) performed between June 2012 and June 2017 at the University of California, San Francisco Center for Reproductive Health, were reviewed retrospectively. Cycles with cleavage-stage embryos or transfer of more than one blastocyst were excluded. Cycles were analyzed to determine if clinical pregnancy occurred with the presence of two or more gestational sacs noted on initial ultrasound. An in-depth chart review was performed with further exclusions applied that would lend credence to dizygosity rather than monozygosity such as fetal/neonatal sex discordance, fresh embryo transfer, and natural cycle FET (in which concomitant spontaneous pregnancy could have occurred). Demographic, clinical and IVF-FET cycle characteristics of the resulting patients were collected. Additionally, a review of the English language literature was performed (PUBMED, PMC) using the search words monozygotic twins, dichorionic diamniotic, in vitro fertilization, and single embryo transfer in order to identify cases of DC-DA monozygotic twinning from 1978 to 2017. Resulting articles were reviewed to eliminate all cases of dizygosity and day 3 embryo transfers. We obtained the following data from the literature search: basic patient demographics, type of fertilization, type and day of embryo transferred, number of embryos transferred, gestational ultrasound details, presence of any genetic testing if performed after delivery, and number of live births. RESULT(S): Two thousand four hundred thirty-four women underwent fresh or frozen single embryo transfer between June 2012 and June 2017 at the University of California, San Francisco Center for Reproductive Health. Of these, 11 women underwent a single blastocyst transfer with subsequent clinical pregnancies identified as multi-chorionic gestations. Four were in downregulated controlled FET cycles, in which concomitant spontaneous pregnancy could not have been possible. We then reviewed all cases of monozygotic dichorionic-diamniotic (DC-DA) splitting in IVF patients reported in the literature from 1978 to 2017. These eight cases demonstrate monozygotic splitting after the blastocyst stage, which challenges the existing dogma that only monochorionic twins can develop after day 3 post-fertilization. CONCLUSION(S): The accepted theory of monozygotic twinning resulting from the splitting of an embryo per a strict post-fertilization timing protocol must be re-examined with the advent of observed multi-chorionic pregnancies resulting from single blastocyst transfer in the context of IVF.

Microfluidic sorting selects sperm for clinical use with reduced DNA damage compared to density gradient centrifugation with swim-up in split semen samples.

STUDY QUESTION: Does microfluidic sorting improve the selection of sperm with lower DNA fragmentation over standard density-gradient centrifugation? SUMMARY ANSWER: Microfluidic sorting of unprocessed semen allows for the selection of clinically usable, highly motile sperm with nearly undetectable levels of DNA fragmentation. WHAT IS KNOWN ALREADY: Microfluidic devices have been explored to sort motile and morphologically normal sperm from a raw sample without centrifugation; however, it is uncertain whether DNA damage is reduced in this process. STUDY DESIGN, SIZE, DURATION: This is a blinded, controlled laboratory study of differences in standard semen analysis parameters and the DNA fragmentation index (DFI) in split samples from infertile men (n = 70) that were discarded after routine semen analysis at an academic medical center. PARTICIPANTS/MATERIALS, SETTING, METHODS: Sperm concentration, progressive motility and forward progression were assessed by microscopic examination. For each sample, the unprocessed semen was tested for DNA fragmentation and split for processing by density-gradient centrifugation with swim-up or sorting by a microfluidic chip. DNA fragmentation was assessed in unprocessed and processed samples by sperm chromatin dispersion assay. The DFI was calculated, from up to 300 cells per slide, as the number of cells with fragmented DNA divided by the number of cells counted per slide. MAIN RESULTS AND THE ROLE OF CHANCE: The median DFI in unprocessed samples was 21% (interquartile range (IQR): 14-30). In paired analyses of all samples, those processed by the microfluidic chip demonstrated significantly decreased DFI compared to those processed by density-gradient centrifugation (P = 0.0029) and unprocessed samples (P < 0.0001). The median DFI for chip specimens was 0% (IQR: 0-2.4) while those processed by density-gradient centrifugation had a median DFI of 6% (IQR: 2-11). Unprocessed samples in the highest DFI quartile (DFI range: 31-40%) had a median DFI of 15% (IQR: 11-19%) after density-gradient centrifugation and DFI of 0% (IQR: 0-1.9%) after processing with the microfluidic chip (P = 0.02). LIMITATIONS, REASONS FOR CAUTION: While a high DFI has been associated with poor outcomes with IVF/ICSI, there are limited data illustrating improvements in clinical outcomes with a reduction in DFI. As this study utilized discarded, non-clinical samples, clinical outcomes data are not available. WIDER IMPLICATIONS OF THE FINDINGS: While microfluidic sorting of unprocessed semen allowed for the selection of clinically usable, highly motile sperm with nearly undetectable levels of DNA fragmentation, standard processing by density-gradient centrifugation with swim-up did not increase DNA fragmentation in an infertile population. The proposed microfluidic technology offers a flow-free approach to sort sperm, requiring no peripheral equipment or filtration step, while minimizing hands-on time. STUDY FUNDING/COMPETING INTEREST(S): No external funding to declare. Utkan Demirci, PhD is the Co-founder and Scientific Advisor for DxNow Inc., LevitasBio Inc. and Koek Biotech. Mitchell Rosen, MD is a member of the Clinical Advisory Board for DxNow Inc.

Role for endogenous estrogen in prepubertal Sertoli cell maturation.

Reducing prepubertal endogenous estrogens led to increased numbers of Sertoli cells and the associated increased testicular size and testicular sperm production capacity in boars. The increased number of Sertoli cells might be due to a longer time for proliferation; delayed differentiation of Sertoli cells during suppressed endogenous estrogens would be consistent with this hypothesized, prolonged proliferation interval. This study used immunohistochemical detection of anti-Müllerian hormone (AMH), a marker of immature Sertoli cells, and of CDKN1B, a cell cycle inhibitor associated with more mature Sertoli cells, to determine if suppressing endogenous estrogens detectably delayed "differentiation" of porcine Sertoli cells. Testes were from littermate pairs of boars previously treated with Letrozole, an aromatase inhibitor, or vehicle, from the first week of age until tissue collection at 2, 3, 4, 5 or 6 months of age. Four animals were examined at each age following Letrozole treatment and their corresponding littermates evaluated following treatment with vehicle. Amount of AMH protein in Sertoli cells decreased with age of boar and could not be detected at 6 months of age. The AMH labeling was greater in the Letrozole-treated boars compared with littermate vehicle controls at 4 months of age (P=0.03). The percentage of CDKN1B-labeled Sertoli cells apparently increased with age through 5 months of age. At 4 and 5 months of age, the mean percentage of CDKN1B-labeled Sertoli cells was less in the Letrozole-treated animals than in the vehicle control animals (P = 0.03 and 0.04, respectively). These results are consistent with the hypothesis that continual inhibition of aromatase (and concomitatant reduced estrogen synthesis) causes a delay in Sertoli cell maturation in boars.