Special ambulatory gynecologic considerations in the era of coronavirus disease 2019 (COVID-19) and implications for future practice.

The coronavirus disease 2019 pandemic has altered medical practice in unprecedented ways. Although much of the emphasis in obstetrics and gynecology to date has been on the as yet uncertain effects of coronavirus disease 2019 in pregnancy and on changes to surgical management, the pandemic has broad implications for ambulatory gynecologic care. In this article, we review important ambulatory gynecologic topics such as safety and mental health, reproductive life planning, sexually transmitted infections, and routine screening for breast and cervical cancer. For each topic, we review how care may be modified during the pandemic, provide recommendations when possible on how to ensure continued access to comprehensive healthcare at this time, and discuss ways that future practice may change. Social distancing requirements may place patients at higher risk for intimate partner violence and mental health concerns, threaten continued access to contraception and abortion services, affect prepregnancy planning, interrupt routine screening for breast and cervical cancer, increase risk of sexually transmitted infection acquisition and decrease access to treatment, and exacerbate already underlying racial and minority disparities in care and health outcomes. We advocate for increased use of telemedicine services with increased screening for intimate partner violence and depression using validated questionnaires. Appointments for long-acting contraceptive insertions can be prioritized. Easier access to patient-controlled injectable contraception and pharmacist-provided hormonal contraception can be facilitated. Reproductive healthcare access can be ensured through reducing needs for ultrasonography and laboratory testing for certain eligible patients desiring abortion and conducting phone follow-up for medication abortions. Priority for in-person appointments should be given to patients with sexually transmitted infection symptoms, particularly if at risk for complications, while also offering expedited partner therapy. Although routine mammography screening and cervical cancer screening may be safely delayed, we discuss society guideline recommendations for higher-risk populations. There may be an increasing role for patient-collected human papillomavirus self-samples using new cervical cancer screening guidelines that can be expanded considering the pandemic situation. Although the pandemic has strained our healthcare system, it also affords ambulatory clinicians with opportunities to expand care to vulnerable populations in ways that were previously underutilized to improve health equity.

Inherited variants of MYH associated with somatic G:C-->T:A mutations in colorectal tumors.

Inherited defects of base excision repair have not been associated with any human genetic disorder, although mutations of the genes mutM and mutY, which function in Escherichia coli base excision repair, lead to increased transversions of G:C to T:A. We have studied family N, which is affected with multiple colorectal adenomas and carcinoma but lacks an inherited mutation of the adenomatous polyposis coli gene (APC) that is associated with familial adenomatous polyposis. Here we show that 11 tumors from 3 affected siblings contain 18 somatic inactivating mutations of APC and that 15 of these mutations are G:C-->A transversions--a significantly greater proportion than is found in sporadic tumors or in tumors associated with familial adenomatous polyposis. Analysis of the human homolog of mutY, MYH, showed that the siblings were compound heterozygotes for the nonconservative missense variants Tyr165Cys and Gly382Asp. These mutations affect residues that are conserved in mutY of E. coli (Tyr82 and Gly253). Tyrosine 82 is located in the pseudo-helix-hairpin-helix (HhH) motif and is predicted to function in mismatch specificity. Assays of adenine glycosylase activity of the Tyr82Cys and Gly253Asp mutant proteins with 8-oxoG:A and G:A substrates show that their activity is reduced significantly. Our findings link the inherited variants in MYH to the pattern of somatic APC mutation in family N and implicate defective base excision repair in predisposition to tumors in humans.

Women Living with Human Immunodeficiency Virus with Intended and Unintended Pregnancy: Characteristics and Patient Outcomes.

Background: Rates of unintended pregnancy may be higher in women living with human immunodeficiency virus (WLWH) than in the general population, and it is unclear how populations of WLWH with intended and unintended pregnancy differ. We compared baseline characteristics and outcomes between WLWH with intended and unintended pregnancy. Materials and Methods: We conducted a retrospective analysis of WLWH enrolled in a human immunodeficiency virus (HIV) and Pregnancy clinic from 2003 to 2014. Data were analyzed using descriptive statistics, chi-square test, Student's t-test, one-way analysis of variance, and linear and logistic regression analysis. Two-tailed p-value <0.05 was considered significant. The study was approved by the Johns Hopkins University School of Medicine Institutional Review Board. Results: Sixty-nine (27.1%) of 255 women reported an intended pregnancy. Women with intended pregnancy (WWIP) were more likely to be older, White, married, privately insured, and college educated. WWIP were less likely to use tobacco (15.9% vs. 44.2%, p < 0.001), alcohol (2.9% vs. 11.1%, p = 0.041), opiates (0.0% vs. 19.3%, p < 0.001), or cocaine (2.9% vs. 21.0%, p < 0.001) during pregnancy, more likely to disclose their HIV status to the father of the baby by delivery (100.0% vs. 15.8%, p < 0.001), and more likely to receive less effective contraception at delivery (condoms 14.9% vs. 4.8%, p = 0.024; sterilization 11.9% vs. 22.1%, p = 0.028). In multivariate regression analysis, pregnancy intendedness was an important predictor of nondetectable viral load at pregnancy entry but not at delivery. Conclusions: WLWH vary in their baseline characteristics and pregnancy outcomes depending on pregnancy intendedness, highlighting the need to improve pregnancy timing in WLWH and intensify interventions for women with unintended pregnancy.

Infant feeding for people living with HIV in high resource settings: a multi-disciplinary approach with best practices to maximise risk reduction.

Shared decision making for infant feeding in the context of HIV in high-resourced settings is necessary to acknowledge patient autonomy, meet increasing patient requests and address the changing reality of perinatal HIV care. In low-to middle-income countries (LMIC), where the majority of individuals living with HIV reside, persons with HIV are recommended to breastfeed their infants. In the setting of maternal anti-retroviral therapy (ART) use throughout pregnancy, viral suppression and appropriate neonatal post-exposure prophylaxis (PEP) use, updated information indicates that the risk of HIV transmission through breastmilk may be between 0.3 and 1%. While not endorsing or recommending breastfeeding, the United States' DHHS perinatal guidelines are similarly pivoting, stating that individuals should "receive patient-centred, evidence-based counselling on infant feeding options." Similar statements appear in the British, Canadian, Swiss, European, and Australasian perinatal guidelines. We assembled a multi-disciplinary group at our institution to develop a structured shared decision-making process and protocol for successful implementation of breastfeeding. We recommend early and frequent counselling about infant feeding options, which should include well known benefits of breastfeeding even in the context of HIV and the individual's medical and psychosocial circumstances, with respect and support for patient's autonomy in choosing their infant feeding option.

Pregnancy Outcomes in Pregnant Women with HIV on Tenofovir Disoproxil Fumarate (TDF) Compared to Tenofovir Alafenamide (TAF).

Objective: Our objective was to assess the safety, efficacy, and pregnancy outcomes of Tenofovir Disoproxil Fumarate (TDF) compared to Tenofovir Alafenamide (TAF) use in pregnant women with HIV (PWLHIV). Methods: This retrospective cohort study of all women who received prenatal care at a single academic center between January 1st 2015 and June 30th, 2020 compared outcomes in PWLHIV using TDF compared to TAF. The primary outcome was weight-gain during pregnancy. Secondary outcomes included CD4 count, viral-load, gestational age at delivery, fetal and neonatal outcomes. Outcomes were analyzed using standard statistical tests. Multivariable linear-regression analysis models accounting for potential confounders were created for primary and secondary outcomes, with beta coefficients (ß) and associated 95% confidence intervals as the primary measure of effect. Statistical analysis was done with STATA 16. Results: There were 66 women in the TDF group and 34 women in the TAF group. In the overall cohort, the median (interquartile range, IQR) gestational age at delivery for PWLHIV on TDF and TAF were 38.6 (IQR 37.5-39.4) and 38.1 (31.1-39.1) weeks respectively; and most women (85%) were Black/African American. Compared to PWLHIV on a TDF regimen, women on TAF, on average, gained over 3 kg more weight in the 3rd trimester of pregnancy (ß=3.20, 95% CI 1.64, 7.97; p=0.03). Women in the TAF arm were also more likely to have higher median CD4-count (470 cells/mm3 versus 669 cells/mm3, p=0.035) in the third trimester compared to women on TDF. There were no cases of neonatal/infant HIV or death. Conclusion: Although TAF use was associated with more weight gain compared to TDF, both regimens appear safe and effective during pregnancy. PWLHIV should be counseled about the potential for weight gain with TAF based regimens during pregnancy.

Experience and Outcomes of Breastfed Infants of Women Living With HIV in the United States: Findings From a Single-Center Breastfeeding Support Initiative.

We assessed breastfeeding outcomes for a cohort of infants born to women living with HIV (WLHIV) at an urban health care center in the United States. Ten infants were exclusively breastfed for a mean duration of 4.4 (1.0-8.6) months. All had negative HIV RNA PCRs at a median age of 16 months.

Structural and biochemical determinants of ligand binding by the c-di-GMP riboswitch .

The bacterial second messenger c-di-GMP is used in many species to control essential processes that allow the organism to adapt to its environment. The c-di-GMP riboswitch (GEMM) is an important downstream target in this signaling pathway and alters gene expression in response to changing concentrations of c-di-GMP. The riboswitch selectively recognizes its second messenger ligand primarily through contacts with two critical nucleotides. However, these two nucleotides are not the most highly conserved residues within the riboswitch sequence. Instead, nucleotides that stack with c-di-GMP and that form tertiary RNA contacts are the most invariant. Biochemical and structural evidence reveals that the most common natural variants are able to make alternative pairing interactions with both guanine bases of the ligand. Additionally, a high-resolution (2.3 A) crystal structure of the native complex reveals that a single metal coordinates the c-di-GMP backbone. Evidence is also provided that after transcription of the first nucleotide on the 3'-side of the P1 helix, which is predicted to be the molecular switch, the aptamer is functional for ligand binding. Although large energetic effects occur when several residues in the RNA are altered, mutations at the most conserved positions, rather than at positions that base pair with c-di-GMP, have the most detrimental effects on binding. Many mutants retain sufficient c-di-GMP affinity for the RNA to remain biologically relevant, which suggests that this motif is quite resilient to mutation.

Unnatural substrates reveal the importance of 8-oxoguanine for in vivo mismatch repair by MutY.

Escherichia coli MutY has an important role in preventing mutations associated with the oxidative lesion 7,8-dihydro-8-oxo-2'-deoxyguanosine (OG) in DNA by excising adenines from OG.A mismatches as the first step of base excision repair. To determine the importance of specific steps in the base pair recognition and base removal process of MutY, we have evaluated the effects of modifications of the OG.A substrate on the kinetics of base removal, mismatch affinity and repair to G-C in an E. coli-based assay. Notably, adenine modification was tolerated in the cellular assay, whereas modification of OG resulted in minimal cellular repair. High affinity for the mismatch and efficient base removal required the presence of OG. Taken together, these results suggest that the presence of OG is a critical feature that is necessary for MutY to locate OG.A mismatches and select the appropriate adenines for excision to initiate repair in vivo before replication.

Cross-reactive microbial peptides can modulate HIV-specific CD8+ T cell responses.

Heterologous immunity is an important aspect of the adaptive immune response. We hypothesized that this process could modulate the HIV-1-specific CD8+ T cell response, which has been shown to play an important role in HIV-1 immunity and control. We found that stimulation of peripheral blood mononuclear cells (PBMCs) from HIV-1-positive subjects with microbial peptides that were cross-reactive with immunodominant HIV-1 epitopes resulted in dramatic expansion of HIV-1-specific CD8+ T cells. Interestingly, the TCR repertoire of HIV-1-specific CD8+ T cells generated by ex vivo stimulation of PBMCs using HIV-1 peptide was different from that of cells stimulated with cross-reactive microbial peptides in some HIV-1-positive subjects. Despite these differences, CD8+ T cells stimulated with either HIV-1 or cross-reactive peptides effectively suppressed HIV-1 replication in autologous CD4+ T cells. These data suggest that exposure to cross-reactive microbial antigens can modulate HIV-1-specific immunity.

Insight into the functional consequences of inherited variants of the hMYH adenine glycosylase associated with colorectal cancer: complementation assays with hMYH variants and pre-steady-state kinetics of the corresponding mutated E.coli enzymes.

The oxidized guanine lesion 7,8-dihydro-8-oxo-2'-deoxyguanosine (OG) is highly mutagenic, resulting in G:C to T:A transversion mutations in the absence of repair. The Escherichia coli adenine glycosylase MutY and its human homolog (hMYH) play an important role in the prevention of mutations associated with OG by removing misincorporated adenine residues from OG:A mismatches. Previously, biallelic mutations of hMYH have been identified in a British family (Family N) with symptoms characteristic of familial adenomatous polyposis (FAP), which is typically associated with mutations in the adenomatous polyposis coli (APC) gene. Afflicted members of this family were compound heterozygotes for two mutations in hMYH, Y165C and G382D. These positions are highly conserved in MutY across phylogeny. The current work reveals a reduced ability of the hMYH variants compared to wild-type (WT) hMYH to complement the activity of E.coli MutY in mutY((-)) E.coli. In vitro analysis of the corresponding mutations in E.coli MutY revealed a reduction in the adenine glycosylase activity of the enzymes. In addition, evaluation of substrate affinity using a substrate analog, 2'-deoxy-2'-fluoroadenosine (FA) revealed that both mutations severely diminish the ability to recognize FA, and discriminate between OG and G. Importantly, adenine removal with both the mutant and WT E.coli enzymes was observed to be less efficient from a mismatch in the sequence context observed to be predominantly mutated in tumors of Family N. Interestingly, the magnitude of the reduced activity of the E.coli mutant enzymes relative to the WT enzyme was magnified in the "hotspot" sequence context. If the corresponding mutations in hMYH cause similar sensitivity to sequence context, this effect may contribute to the specific targeting of the APC gene. The lack of complementation of the hMYH variants for MutY, and the reduced activity of the Y82C and G253D E.coli enzymes, provide additional circumstantial evidence that the somatic mutations in APC, and the occurrence of FAP in Family N, are due to a reduced ability of the Y165C and G382D hMYH enzymes to recognize and repair OG:A mismatches.

Clinical outcomes in patients with cytomegalovirus retinitis treated with ganciclovir implant.

PURPOSE: To describe the clinical outcomes of patients with cytomegalovirus (CMV) retinitis and AIDS treated with ganciclovir implant. DESIGN: Retrospective cohort study. METHODS: The charts of 115 patients (166 affected eyes) with CMV retinitis treated with ganciclovir implant in the Division of Ocular Immunology, Wilmer Eye Institute from April 1996 through November 2009 were reviewed. Ophthalmologic data collected included visual acuity, ocular complications, treatment, and presence of immune recovery. Kaplan-Meier analyses and Cox regression models were used to investigate relationships between potential risk factors and ocular outcomes. RESULTS: At implantation, 55% of patients were prescribed highly active antiretroviral therapy (HAART), 21% were formerly on HAART, and 24% were HAART-naïve. One hundred sixty-six eyes received 257 ganciclovir implants. Fifty-seven of the implanted eyes were diagnosed with a total of 126 ocular complications after implant surgery (rate=0.19/eye-year [EY]), the 3 most common being cataract, vitreous hemorrhage, and retinal detachment. Despite these ocular complications, the development of severe vision loss (≥6 lines lost) was low (0.005/EY). Patients with immune recovery during follow-up were less likely to have ocular complications after implant surgery; however, only the risk reduction for retinal detachment achieved statistical significance (hazard ratio=0.29, 95% CI: 0.08, 0.98). CONCLUSIONS: Our data suggest that ocular complications after implant surgery, including cataract, vitreous hemorrhage, and retinal detachment, were relatively common after ganciclovir implantation but severe vision loss after surgery was low. Presence of immune recovery may lessen the risk of postoperative ocular complications.

Adenine removal activity and bacterial complementation with the human MutY homologue (MUTYH) and Y165C, G382D, P391L and Q324R variants associated with colorectal cancer.

MUTYH-associated polyposis (MAP) is the only inherited colorectal cancer syndrome that is associated with inherited biallelic mutations in a base excision repair gene. The MUTYH glycosylase plays an important role in preventing mutations associated with 8-oxoguanine (OG) by removing adenine residues that have been misincorporated opposite OG. MAP-associated mutations are present throughout MUTYH, with a large number coding for missense variations. To date the available information on the functional properties of MUTYH variants is conflicting. In this study, a kinetic analysis of the adenine glycosylase activity of MUTYH and several variants was undertaken using a correction for active fraction to control for differences due to overexpression and purification. Using these methods, the rate constants for steps involved in the adenine removal process were determined for the MAP variants Y165C, G382D, P391L and Q324R MUTYH. Under single-turnover conditions, the rate of adenine removal for these four variants was found to be 30-40% of WT MUTYH. In addition, the ability of MUTYH and the variants to suppress mutations and complement for the absence of MutY in Escherichia coli was assessed using rifampicin resistance assays. The presence of WT and Q324R MUTYH resulted in complete suppression of the mutation frequency, while G382D MUTYH showed reduced ability to suppress the mutation frequency. In contrast, the mutation frequency observed upon expression of P391L and Y165C MUTYH were similar to the controls, suggesting no activity toward preventing DNA mutations. Notably, though all variations studied herein resulted in similar reductions in adenine glycosylase activity, the effects in the bacterial complementation are quite different. This suggests that the consequences of a specific amino acid variation on overall repair in a cellular context may be magnified.

Insight into the roles of tyrosine 82 and glycine 253 in the Escherichia coli adenine glycosylase MutY.

The oxidation product of 2'-deoxyguanosine, 7,8-dihydro-8-oxo-2'-deoxyguanosine (OG), produces G:C to T:A transversion mutations. The Escherichia coli base excision repair glycosylase MutY plays an important role in preventing OG-associated mutations by removing adenines misincorporated opposite OG lesions during DNA replication. Recently, biallelic mutations in the human MutY homologue (hMYH) have been correlated with the development of colorectal cancer. The two most common mutations correspond to two single amino acid substitutions in the hMYH protein: Y165C and G382D [Al-Tassan, N., et al. (2002) Nat. Genet. 30, 227-232]. Previously, our laboratory analyzed the adenine glycosylase activity of the homologous variant E. coli MutY enzymes, Y82C and G253D [Chmiel, N. H., et al. (2003) J. Mol. Biol. 327, 431-443]. This work demonstrated that both variants have a reduced adenine glycosylase activity and affinity for substrate analogues compared to wild-type MutY. Recent structural work on Bacillus stearothermophilus MutY bound to an OG:A mismatch-containing duplex indicates that both residues aid in recognition of OG [Fromme, J. C., et al. (2004) Nature 427, 652-656]. To determine the extent with which Tyr 82 and Gly 253 contribute to catalysis of adenine removal by E. coli MutY, we made a series of additional modifications in these residues, namely, Y82F, Y82L, and G253A. When the substrate analogue 2'-deoxy-2'-fluoroadenosine (FA) in duplex paired with G or OG is used, both Y82F and G253A showed reduced binding affinity, and G253A was unable to discriminate between OG and G when paired with FA. Additionally, compromised glycosylase activity of Y82F, Y82C, and G253A MutY was observed using the nonoptimal G:A substrate, or at low reaction temperatures. Interestingly, adenine removal from an OG:A-containing DNA substrate by Y82C MutY was also shown to be extremely sensitive to the NaCl concentration. The most surprising result was the remarkably similar activity of Y82L MutY to the WT enzyme under all conditions examined, indicating that a leucine residue may effectively replace tyrosine for intercalation at the OG:A mismatch. The results contained herein provide further insight regarding the intricate roles of Tyr 82 and Gly 253 in the OG recognition and adenine excision functions of MutY.

Protein-DNA charge transport: redox activation of a DNA repair protein by guanine radical.

DNA charge transport (CT) chemistry provides a route to carry out oxidative DNA damage from a distance in a reaction that is sensitive to DNA mismatches and lesions. Here, DNA-mediated CT also leads to oxidation of a DNA-bound base excision repair enzyme, MutY. DNA-bound Ru(III), generated through a flash/quench technique, is found to promote oxidation of the [4Fe-4S](2+) cluster of MutY to [4Fe-4S](3+) and its decomposition product [3Fe-4S](1+). Flash/quench experiments monitored by EPR spectroscopy reveal spectra with g = 2.08, 2.06, and 2.02, characteristic of the oxidized clusters. Transient absorption spectra of poly(dGC) and [Ru(phen)(2)dppz](3+) (dppz = dipyridophenazine), generated in situ, show an absorption characteristic of the guanine radical that is depleted in the presence of MutY with formation instead of a long-lived species with an absorption at 405 nm; we attribute this absorption also to formation of the oxidized [4Fe-4S](3+) and [3Fe-4S](1+) clusters. In ruthenium-tethered DNA assemblies, oxidative damage to the 5'-G of a 5'-GG-3' doublet is generated from a distance but this irreversible damage is inhibited by MutY and instead EPR experiments reveal cluster oxidation. With ruthenium-tethered assemblies containing duplex versus single-stranded regions, MutY oxidation is found to be mediated by the DNA duplex, with guanine radical as an intermediate oxidant; guanine radical formation facilitates MutY oxidation. A model is proposed for the redox activation of DNA repair proteins through DNA CT, with guanine radicals, the first product under oxidative stress, in oxidizing the DNA-bound repair proteins, providing the signal to stimulate DNA repair.

DNA-mediated charge transport for DNA repair.

MutY, like many DNA base excision repair enzymes, contains a [4Fe4S]2+ cluster of undetermined function. Electrochemical studies of MutY bound to a DNA-modified gold electrode demonstrate that the [4Fe4S] cluster of MutY can be accessed in a DNA-mediated redox reaction. Although not detectable without DNA, the redox potential of DNA-bound MutY is approximately 275 mV versus NHE, which is characteristic of HiPiP iron proteins. Binding to DNA is thus associated with a change in [4Fe4S]3+/2+ potential, activating the cluster toward oxidation. Given that DNA charge transport chemistry is exquisitely sensitive to perturbations in base pair structure, such as mismatches, we propose that this redox process of MutY bound to DNA exploits DNA charge transport and provides a DNA signaling mechanism to scan for mismatches and lesions in vivo.