N-Cα Bond Cleavage Catalyzed by a Multinuclear Iron Oxygenase from a Divergent Methanobactin-like RiPP Gene Cluster.

DUF692 multinuclear iron oxygenases (MNIOs) are an emerging family of tailoring enzymes involved in the biosynthesis of ribosomally synthesized and post-translationally modified peptides (RiPPs). Three members, MbnB, TglH, and ChrH, have been characterized to date and shown to catalyze unusual and complex transformations. Using a co-occurrence-based bioinformatic search strategy, we recently generated a sequence similarity network of MNIO-RiPP operons that encode one or more MNIOs adjacent to a transporter. The network revealed >1000 unique gene clusters, evidence of an unexplored biosynthetic landscape. Herein, we assess an MNIO-RiPP cluster from this network that is encoded in Proteobacteria and Actinobacteria. The cluster, which we have termed mov (for methanobactin-like operon in Vibrio), encodes a 23-residue precursor peptide, two MNIOs, a RiPP recognition element, and a transporter. Using both in vivo and in vitro methods, we show that one MNIO, homologous to MbnB, installs an oxazolone-thioamide at a Thr-Cys dyad in the precursor. Subsequently, the second MNIO catalyzes N-Cα bond cleavage of the penultimate Asn to generate a C-terminally amidated peptide. This transformation expands the reaction scope of the enzyme family, marks the first example of an MNIO-catalyzed modification that does not involve Cys, and sets the stage for future exploration of other MNIO-RiPPs.

Hirocidins, Cytotoxic Metabolites from Streptomyces hiroshimensis, Induce Mitochondrion-mediated Apoptosis.

Recent advances in whole genome sequencing have revealed an immense microbial potential for the production of therapeutic small molecules, even from well-known producers. To access this potential, we subjected prominent antimicrobial producers to alternative antiproliferative assays using persistent cancer cell lines. Described herein is our discovery of hirocidins, novel secondary metabolites from Streptomyces hiroshimensis with antiproliferative activities against colon and persistent breast cancer cells. Hirocidin A is an unusual nine-membered carbocyclic maleimide and hirocidins B and C are relatives with an unprecedented, bridged azamacrocyclic backbone. Mode of action studies show that hirocidins trigger mitochondrion-dependent apoptosis by inducing expression of the key apoptotic effector caspase-9. The discovery of new cytotoxins contributes to scaffold diversification in anticancer drug discovery and the reported modes of action and concise total synthetic route for variant A set the stage for unraveling specific targets and biochemical interactions of the hirocidins.

Momomycin, an Antiproliferative Cryptic Metabolite from the Oxytetracycline Producer Streptomyces rimosus.

Natural products provide an important source of pharmaceuticals and chemical tools. Traditionally, assessment of unexplored microbial phyla has led to new natural products. However, with every new microbe, the number of orphan biosynthetic gene clusters (BGC) grows. As such, the more difficult proposition is finding new molecules from well-studied strains. Herein, we targeted Streptomyces rimosus, the widely-used oxytetracycline producer, for the discovery of new natural products. Using MALDI-MS-guided high-throughput elicitor screening (HiTES), we mapped the global secondary metabolome of S. rimosus and structurally characterized products of three cryptic BGCs, including momomycin, an unusual cyclic peptide natural product with backbone modifications and several non-canonical amino acids. We elucidated important aspects of its biosynthesis and evaluated its bioactivity. Our studies showcase HiTES as an effective approach for unearthing new chemical matter from "drained" strains.

Structural Elucidation of Cryptic Algaecides in Marine Algal-Bacterial Symbioses by NMR Spectroscopy and MicroED.

Microbial secondary metabolite discovery is often conducted in pure monocultures. In a natural setting, however, where metabolites are constantly exchanged, biosynthetic precursors are likely provided by symbionts or hosts. In the current work, we report eight novel and architecturally unusual secondary metabolites synthesized by the bacterial symbiont Phaeobacter inhibens from precursors that, in a native context, would be provided by their algal hosts. Three of these were produced at low titres and their structures were determined de novo using the emerging microcrystal electron diffraction method. Some of the new metabolites exhibited potent algaecidal activity suggesting that the bacterial symbiont can convert algal precursors, tryptophan and sinapic acid, into complex cytotoxins. Our results have important implications for the parasitic phase of algal-bacterial symbiotic interactions.

Surgical site infections in gynecology: the latest evidence for prevention and management.

PURPOSE OF REVIEW: Surgical site infection (SSI) remains one of the most common postoperative surgical complications. Prevention and appropriate treatment remain paramount. RECENT FINDINGS: Evidence-based recommendations include recognition and reduction of preoperative risks including hyperglycemia and smoking, treatment of preexisting infections, skin preparation with chlorhexidine gluconate, proper use of preoperative antibiotics, and implementation of prevention bundles. Consideration should be given to the use of dual antibiotic preoperative treatment with cephazolin and metronidazole for all hysterectomies. SUMMARY: Despite advancements, SSI in gynecologic surgery remains a major cause of perioperative morbidity and healthcare cost. Modifiable risk factors should be evaluated and patients optimized to the best extent possible prior to surgery. Preoperative risks include obesity, hyperglycemia, smoking, and untreated preexisting infections. Intraoperative risk-reducing strategies include appropriate perioperative antibiotics, correct topical preparation, maintaining normothermia, and minimizing blood loss. Additionally, early recognition and prompt treatment of SSI remain crucial.

Placement of mid-urethral mesh slings at the time of vaginal prolapse repair does not affect post-operative sexual function or orgasm.

INTRODUCTION AND HYPOTHESIS: Because of the relationship between the clitoral neurovascular supply and the urethra, the dissection for placement of mid-urethral slings (MUS) may negatively impact orgasmic function. We aimed to analyze the role of MUS in orgasmic and overall sexual function in patients undergoing prolapse surgery. METHODS: A single institution retrospective review was performed on 157 patients undergoing prolapse surgery with and without MUS from 2008 to 2014. Pelvic Organ Prolapse Incontinence Sexual Questionnaires (PISQ-12) scores at baseline, 6, and 12 months post-operatively were compared. The difference in overall mean post-operative PISQ-12 scores at 6 and 12 months in those undergoing POP with or without MUS placement was assessed using Wilcoxon rank tests. RESULTS: Of 157 women who underwent prolapse surgery, 81 (52%) had concomitant MUS. Mean baseline PISQ-12 scores were 32 in both groups (p = 0.98). Post-operative PISQ-12 scores between the two groups did not differ at 6 (p = 0.96) or 12 months (p = 0.65). Within the MUS group, mean overall PISQ-12 scores improved at 6 (p = 0.05) and 12 months (p < 0.01). Mean overall PISQ-12 scores did not improve in patients who did not have slings placed at 6 (p = 0.10) or 12 months (p = 0.15). Orgasm frequency and intensity did not differ between the two groups at 6 (p = 0.39, p = 0.91, respectively) or 12 months (p = 0.11, p = 0.44, respectively). CONCLUSION: MUS at the time of prolapse repair did not affect orgasmic or overall sexual function. PISQ-12 scores improved after prolapse surgery with concomitant MUS placement. Our findings may help counsel patients regarding the risk of MUS placement affecting sexual function.

A Systematic Review of Validity Evidence for the Fundamentals of Laparoscopic Surgery Examination in Gynecology.

OBJECTIVE: The Fundamentals in Laparoscopic Surgery (FLS) examination is designed to test laparoscopic surgery skills. Our aim for this systematic review was to examine validity evidence supporting or refuting the FLS examination specifically as a high-stakes summative assessment tool in gynecology. DATA SOURCES: The data sources were PubMed, MEDLINE, Embase, and Scopus. METHODS OF STUDY SELECTION: The study eligibility criterion was the subject of the FLS examination as an assessment tool in gynecology. We developed a data extraction tool and assigned articles for screening and extraction to all authors, who then abstracted data independently. Conflicts that arose during the extraction process were resolved by consensus. We organized validity evidence for the cognitive and manual skills portions on the basis of the categories of current validation standards. TABULATION, INTEGRATION, AND RESULTS: From 1971 citations identified, 9 studies were included, involving 319 participants. For the cognitive portion of the test, the results were mixed in 5 studies in relationships with the other variables category. For the manual portion of the test, most of the studies focused on the relationships with other variables evidence with mixed findings. The concerning findings in the manual skills portion included the lack of transferability of skills to the operating room, limited mixed evidence for improvement in operating room performance, and worse performance by obstetrics and gynecology surgeons compared with other specialties. We did not find supportive content-based, response process, or consequential evidence in either the cognitive or manual skills portion of the test. CONCLUSION: Validity evidence for the FLS examination was either mixed, as it pertained to relationships with other variables, or lacking in other important evidence categories. Further evidence is required to justify the use of the FLS examination scores as a high-stakes summative assessment.

Where Have All the Emergencies Gone? The Impact of the COVID-19 Pandemic on Obstetric and Gynecologic Procedures and Consults at a New York City Hospital.

STUDY OBJECTIVE: The purpose of this study was to assess the impact of the coronavirus disease 2019 (COVID-19) pandemic on surgical volume and emergency department (ED) consults across obstetrics-gynecology (OB-GYN) services at a New York City hospital. DESIGN: Retrospective cohort study. SETTING: Tertiary care academic medical center in New York City. PATIENTS: Women undergoing OB-GYN ED consults or surgeries between February 1, 2020 and April 15, 2020. INTERVENTIONS: March 16 institutional moratorium on elective surgeries. MEASUREMENTS AND MAIN RESULTS: The volume and types of surgeries and ED consults were compared before and after the COVID-19 moratorium. During the pandemic, the average weekly volume of ED consults and gynecology (GYN) surgeries decreased, whereas obstetric (OB) surgeries remained stable. The proportions of OB-GYN ED consults, GYN surgeries, and OB surgeries relative to all ED consults, all surgeries, and all labor and delivery patients were 1.87%, 13.8%, 54.6% in the pre-COVID-19 time frame (February 1-March 15) vs 1.53%, 21.3%, 79.7% in the COVID-19 time frame (March 16-April 15), representing no significant difference in proportions of OB-GYN ED consults (p = .464) and GYN surgeries (p = .310) before and during COVID-19, with a proportionate increase in OB surgeries (p <.002). The distribution of GYN surgical case types changed significantly during the pandemic with higher proportions of emergent surgeries for ectopic pregnancies, miscarriages, and concern for cancer (p <.001). Alternatively, the OB surgery distribution of case types remained relatively constant. CONCLUSION: This study highlights how the pandemic has affected the ways that patients in OB-GYN access and receive care. Institutional policies suspending elective surgeries during the pandemic decreased GYN surgical volume and affected the types of cases performed. This decrease was not appreciated for OB surgical volume, reflecting the nonelective and time-sensitive nature of obstetric care. A decrease in ED consults was noted during the pandemic begging the question "Where have all the emergencies gone?" Although the moratorium on elective procedures was necessary, "elective" GYN surgeries remain medically indicated to address symptoms such as pain and bleeding and to prevent serious medical sequelae such as severe anemia requiring transfusion. As we continue to battle COVID-19, we must not lose sight of those patients whose care has been deferred.

Deprescribing long-term opioid therapy in patients with chronic pain.

Proposed regulatory changes will limit the access to opioids by Australian patients with chronic pain, many of whom are under the care of consultant physicians. This review summarises points of consensus on opioid deprescribing that emerged from the interaction of an expert panel and the audience at a symposium on the topic held in Sydney in 2019. Each of these consensus points speaks to the need for an individualised, patient-centred approach. In other words, 'treat the patient, not the pill count'.

Optimizing surgical management of patients who decline blood transfusion.

PURPOSE OF REVIEW: This review highlights the complexity of caring for gynecologic patients who refuse blood transfusion and discusses the importance of early, targeted perioperative and intraoperative medical optimization. We review alternative interventions and the importance of medical management to minimize blood loss and maximize hematopoiesis, particularly in gynecologic patients who may have significant uterine bleeding. The review also focuses on intraoperative interventions and surgical techniques to prevent and control surgical blood loss. RECENT FINDINGS: With improvements in surgical technique, greater availability of minimally invasive surgery, and increased use of preop UAE and cell salvage, definitive surgical management can be safely performed. New technologies have been developed that allow for safer surgeries or alternatives to traditional surgical procedures. Many medical therapies have been shown to decrease blood loss and improve surgical outcomes. Nonsurgical interventions have also been developed for use as adjuncts or alternatives to surgery. SUMMARY: The care of a patient who declines blood transfusion may be complex, but gynecologic surgeons can safely and successfully offer a wide variety of therapies depending on the patient's goals and needs. Medical management should be implemented early. A multidisciplinary team should be mobilized to provide comprehensive and patient-centered care.

The sticky business of adhesion prevention in minimally invasive gynecologic surgery.

PURPOSE OF REVIEW: The negative impact of postoperative adhesions has long been recognized, but available options for prevention remain limited. Minimally invasive surgery is associated with decreased adhesion formation due to meticulous dissection with gentile tissue handling, improved hemostasis, and limiting exposure to reactive foreign material; however, there is conflicting evidence on the clinical significance of adhesion-related disease when compared to open surgery. Laparoscopic surgery does not guarantee the prevention of adhesions because longer operative times and high insufflation pressure can promote adhesion formation. Adhesion barriers have been available since the 1980s, but uptake among surgeons remains low and there is no clear evidence that they reduce clinically significant outcomes such as chronic pain or infertility. In this article, we review the ongoing magnitude of adhesion-related complications in gynecologic surgery, currently available interventions and new research toward more effective adhesion prevention. RECENT FINDINGS: Recent literature provides updated epidemiologic data and estimates of healthcare costs associated with adhesion-related complications. There have been important advances in our understanding of normal peritoneal healing and the pathophysiology of adhesions. Adhesion barriers continue to be tested for safety and effectiveness and new agents have shown promise in clinical studies. Finally, there are many experimental studies of new materials and pharmacologic and biologic prevention agents. SUMMARY: There is great interest in new adhesion prevention technologies, but new agents are unlikely to be available for clinical use for many years. High-quality effectiveness and outcomes-related research is still needed.

Use of yoked prisms in patients with acquired brain injury: a retrospective analysis.

PRIMARY OBJECTIVE: The purpose of this retrospective study was to determine the clinical practices for prescribing yoked prisms, as well as to assess related patient responses, in a sample of visually-symptomatic patients having acquired brain injury (ABI). METHODS: The clinical records of individuals with acquired brain injury (ABI) that were assessed for yoked prisms were reviewed retrospectively. This query resulted in 60 patient records for analysis between January 2011 and December 2012. The following diagnostic groups were analysed: homonymous hemianopsia (HH)/homonymous quadranopsia, abnormal egocentric localization (AEL) and visual neglect. RESULTS: HH/homonymous quadranopsia (58.3%) was the primary indication to prescribe yoked prisms, followed by visual neglect/unilateral spatial inattention (USI) (40.0%) and AEL (11.7%). The most common favourable patient responses were increased awareness of their blind visual field and improved gait, mobility and balance. The magnitude and direction of prisms prescribed were dependent upon the subjective responses in patients manifesting AEL. In contrast, base direction was dependent upon the direction of visual field loss in patients with HH/homonymous quadranopsia and visual neglect. CONCLUSIONS: Two-thirds of the present sample population responded favourably to the yoked prisms. The results of the present study should prove useful to clinicians for the successful prescription of yoked prisms as a treatment modality in patients presenting with the above three diagnoses.

Genome mining for new enediyne antibiotics.

Enediyne antibiotics epitomize nature's chemical creativity. They contain intricate molecular architectures that are coupled with potent biological activities involving double-stranded DNA scission. The recent explosion in microbial genome sequences has revealed a large reservoir of novel enediynes. However, while hundreds of enediyne biosynthetic gene clusters (BGCs) can be detected, less than two dozen natural products have been characterized to date as many clusters remain silent or sparingly expressed under standard laboratory growth conditions. This review focuses on four distinct strategies, which have recently enabled discoveries of novel enediynes: phenotypic screening from rare sources, biosynthetic manipulation, genomic signature-based PCR screening, and DNA-cleavage assays coupled with activation of silent BGCs via high-throughput elicitor screening. With an abundance of enediyne BGCs and emerging approaches for accessing them, new enediyne natural products and further insights into their biogenesis are imminent.

Maternity Leave Satisfaction Among Physicians Compared with Nonphysician Professionals.

Objective: The objective of this study was to compare maternity leave satisfaction between physicians and nonphysicians. Currently, paid maternal leave is not guaranteed in the United States, resulting in palpable dissatisfaction among parents. Previous studies have shown associations between length of paid leave and career satisfaction and maternal happiness. Materials and Methods: A Qualtrics® electronic survey was distributed to female professionals through email and social media from April 2019 to March 2020. Inclusion criterion was ≥1 child by birth or adoption, or active pregnancy. Continuous and categorical data were analyzed using two-sample t-test and chi-square, respectively. Results: Of 808 respondents, 77% were physicians. Mean age at birth/adoption of first child was higher in physicians versus nonphysicians (32.1 years vs. 29.7 years; p < 0.001). Physicians took shorter maternity leave than nonphysicians (10.9 weeks vs. 12.0 weeks, p = 0.017) with half of that time paid by employers (5.4 weeks vs. 5.9 weeks, p = 0.2). Dissatisfaction was high among physicians (85.1%) and nonphysicians (92.4%) that correlates with maternity leave compensation dissatisfaction (49% vs. 71.3%, p < 0.001). Thirty-four percent of physicians versus 41% of nonphysicians stated that their health was negatively impacted by maternity leave length. Physicians and nonphysicians reported similar incidences of depression, and breastfeeding, delivery, and other postpartum complications. When queried, 38.8% of physicians and 57% of nonphysicians said they would desire >16 weeks of paid maternity leave (p < 0.001). Conclusions: In conclusion, dissatisfaction among professional women on maternity leave duration and compensation is high in the United States. Given health implications for both mother and child, this should invite further discussion and changes.

Programmed cell death in a patient with hepatocellular carcinoma treated with yttrium-90 and doxorubicin-loaded beads.

Molecular analysis of apoptosis and autophagy pathways was performed from a single hepatocellular carcinoma treated with yttrium-90 and doxorubicin-loaded beads before resection and compared with normal liver tissue from the margins. Both bead formulations activated apoptosis-associated mechanisms and increased autophagy pathway protein levels. Increased DNA fragmentation and autophagy markers were seen in tumor treated with drug-eluting beads compared with yttrium-90-treated tumor. These results suggest that both microembolic therapies activate cell death signaling, although differences in apoptosis and autophagy pathways were seen in this patient. Knowledge of mechanisms of action for each treatment may enhance future therapeutic strategies.

Targeted Discovery of Cryptic Enediyne Natural Products via FRET-Coupled High-Throughput Elicitor Screening.

Enediyne antibiotics are a striking family of DNA-cleaving natural products with high degrees of cytotoxicity and structural complexity. Microbial genome sequences, which have recently accumulated, point to an untapped trove of "cryptic" enediynes. Most of the cognate biosynthetic gene clusters (BGCs) are sparingly expressed under standard growth conditions, making it difficult to characterize their products. Herein, we report a fluorescence-based DNA cleavage assay coupled with high-throughput elicitor screening for the rapid, targeted discovery of cryptic enediyne metabolites. We applied the approach to Streptomyces clavuligerus, which harbors two such BGCs with unknown products, identified steroids as effective elicitors, and characterized 10 cryptic enediyne-derived natural products, termed clavulynes A-J with unusual carbonate and terminal olefin functionalities, with one of these congeners matching the recently reported jejucarboside. Our results contribute to the growing repertoire of enediynes and provide a blueprint for identifying additional ones in the future.

Fresh surgical specimens yield breast stem/progenitor cells and reveal their oncogenic abnormalities.

BACKGROUND: The process by which breast cancer stem cells arise is unknown. It may be that the benign stem cells in breast tissue are transformed into malignant stem cells through the acquisition of genetic abnormalities. In this study, we collected and compared benign and malignant breast stem/progenitor cells to determine whether specific genetic abnormalities occur in breast cancer stem/progenitor cells within the human body. METHODS: Fresh surgical specimens from benign and malignant breast tissues were obtained directly from the operating room and examined. Cells variably expressing stem cell-associated surface markers CD49f and CD24 were collected by fluorescence-activated cell sorting. The frequencies of these cells in benign and malignant breast tissues were ascertained. Oncogenetic mutation analyses were performed and expression of stem cell-associated genes was measured. RESULTS: The frequencies of stem/progenitor cells were similar between benign and malignant tissues. Stem cell-associated gene expression also was similar between benign and malignant stem cells. Genetic mutations in the PIK/AKT pathway were found in 73% of the tumors' stem cells, specifically within two subpopulations. No mutations were found in stem/progenitor cell subpopulations from benign breast tissue. CONCLUSIONS: The results of this study suggest that, following malignant transformation, breast cancer stem/progenitor cells retain their stem cell functions and relative frequencies. In addition, they develop malignant capabilities by acquiring mutations in genes critical for maintaining normal cellular metabolism and proliferation.

Targeted Discovery of Cryptic Metabolites with Antiproliferative Activity.

Microorganisms have provided a rich source of therapeutically valuable natural products. Recent advances in whole genome sequencing and bioinformatics have revealed immense untapped potential for new natural products in the form of silent or "cryptic" biosynthetic genes. We herein conducted high-throughput elicitor screening (HiTES) in conjunction with cytotoxicity assays against selected cancer cell lines with the goal of uncovering otherwise undetectable cryptic metabolites with antiproliferative activity. Application to Streptomyces clavuligerus facilitated identification of clavamates A and B, two bioactive metabolites with unusual structural features, as well as facile activation of a gene cluster coding for tunicamycin, which exhibited strong growth-inhibitory activity. The elicitor we identified was pleiotropic, additionally leading to the discovery of a modified, bicyclic pentapeptide natural product. Our results highlight the utility of this approach in identifying new molecules with antiproliferative activity from even overexploited microbial strains.

Alternative therapy used as primary treatment for breast cancer negatively impacts outcomes.

BACKGROUND: The use of complementary and alternative medicine (CAM) has escalated over the past decade, despite the fact that clinical studies validating the efficacy of CAM remain sparse. Clinicians frequently encounter patients who reject standard treatment, but data on outcomes of patients choosing CAM as primary treatment for breast cancer are also lacking. MATERIALS AND METHODS: Breast cancer patients who refused/delayed standard treatments in favor of alternative therapies were identified in a community surgical practice over a 10-year period. A retrospective chart review was performed with telephone interviews when possible. Estimated 10-year survival given recommended treatment was calculated. RESULTS: A total of 61 patients was identified; median age was 53. Median follow-up was 54 months. Patients were stratified into 2 subgroups: those who omitted/delayed surgery (SSG, n = 26) and those who were nonadherent to adjuvant therapy recommendations (ASG, n = 35). In the SSG, 96.2% experienced disease progression; 50% died of disease. Mean stage at initial presentation was II; mean stage at re-presentation after primary treatment with alternative therapies was IV. Disease progression occurred in 86.2% of those in the ASG; 20% died of disease. The mean 10-year survival calculated for those omitting surgery was 69.5%; observed survival for this group was 36.4% at a median follow-up of 33 months. CONCLUSIONS: Alternative therapies used as primary treatment for breast cancer are associated with disease progression and increased risk of recurrence and death. Diminished outcomes are more profound in those delaying/omitting surgery. Reviewing these results with our patients may help bridge the gap between CAM and standard treatments.

Robotic Surgery: Advancements and Inflection Points in the Field of Gynecology.

Robotics has become an essential part of the surgical armamentarium for a growing number of surgeons around the world. New companies seek to compete with established robotic systems that have dominated the market to date. Evolving robotic surgery platforms have introduced technologic and design advancements to optimize ergonomics, improve visualization, provide haptic feedback, and make systems smaller and cheaper. With the introduction of any new technology in the operating room, it is imperative that safeguards be in place to ensure its appropriate use. Current processes for granting of hospital robotic surgery privileges are inadequate and must be strengthened and standardized.