Evaluating the Outcomes and Trainee Performance of a Canadian Medical Imaging Clinician Investigator Program.

Purpose: To measure the research productivity of trainees from the University of Toronto's Medical Imaging Clinician Investigator Program (MI-CIP) and comparing it with the research productivity of trainees from MI-non-CIP and General Surgery (GSx) Clinician Investigator Program. Methods: We identified residents who completed an MI-CIP, MI-non-CIP and GSx-CIP from 2006-2016. In each group of trainees, we assessed 3 research productivity outcomes with non-parametric tests before residency and at 7 years post-CIP completion/post-graduation. Research productivity outcomes include the number of total publications, the number of first-author publications, and the publication's average journal impact factor (IF). Results: We identified 11 MI-CIP trainees (male/female: 9 [82%]/2 [18%]), 74 MI-non-CIP trainees (46 [62%]/28 [38%]) and 41 GSx-CIP trainees (23 [56%]/18 [44%]). MI-CIP trainees had statistically significant higher research productivity than MI-non-CIP in all measured outcomes. The median (interquartile range, IQR) number of total publications of MI-CIP vs MI-non-CIP trainees was 5.0 (8.0) vs 1.0 (2.0) before residency and 6.0 (10.0) vs .0 (2.0) at 7 years post-CIP completion/post-graduation. The median (IQR) first-author publications of MI-CIP vs MI-non-CIP trainees was 2.0 (3.0) vs .0 (1.0) before residency and 2.0 (4.0) vs (.0) (1.0) at 7 years post-CIP completion/post-graduation. The median (IQR) average journal IF of MI-CIP vs MI-non-CIP trainees was 3.2 (2.0) vs .3 (2.4) before residency and 3.9 (3.2) vs .0 (2.6) at 7 years post-CIP completion/post-graduation. Between MI-CIP and GSx-CIP trainees, there were no significant differences in research productivity in all measured outcomes. Conclusion: MI-CIP trainees actively conducted research after graduation. These trainees demonstrated early research engagement before residency. The similar research productivity of MI-CIP vs GSx-CIP trainees shows initial success of MI-CIP trainees.

Congenital malformations and preeclampsia associated with integrase inhibitor use in pregnancy: A single-center analysis.

BACKGROUND: Antiretroviral therapy (ART) decreases perinatal HIV transmission, but concerns exist regarding maternal and infant safety. We compared the incidence of congenital malformations and other adverse outcomes in pregnancies exposed to integrase inhibitor (INSTI) versus non-INSTI ART. SETTING: Single-site review of all pregnancies among women living with HIV between 2008 and 2018. METHODS: We used binomial family generalized estimating equations to model the relationship of congenital anomalies and pregnancy outcomes with exposure to INSTI or dolutegravir (DTG) versus non-INSTI ART. RESULTS: Among 257 pregnancies, 77 women received ≥1 INSTI (54 DTG, 14 elvitegravir, 15 raltegravir), 167 received non-INSTI, and 3 had missing data. Fifty congenital anomalies were identified in 36 infants. Infants with first-trimester DTG or any first-trimester INSTI exposure had higher odds of congenital anomalies than infants with first-trimester non-INSTI exposure (OR = 2.55; 95%CI = 1.07-6.10; OR = 2.61; 95%CI = 1.15-5.94, respectively). Infants with INSTI exposure after the second trimester had no increased odds of anomalies. Women with INSTI exposure had higher odds of preeclampsia (OR = 4.73; 95%CI = 1.70-13.19). Among women who received INSTI, grade ≥3 laboratory abnormalities were noted in 2.6% while receiving the INSTI and 3.9% while not receiving the INSTI, versus 16.2% in women who received non-INSTI. There was no association between INSTI exposure and other pregnancy outcomes. CONCLUSION: In our cohort, first-trimester INSTI exposure was associated with increased rates of congenital anomalies and use of INSTI during pregnancy was associated with preeclampsia. These findings underscore the need for continued monitoring of the safety of INSTI in pregnancy.

A Pregnant Patient Presents with Leakage of Vaginal Fluid in the Second Trimester.

Leakage of Vaginal Fluid in the Second TrimesterA pregnant 43-year-old woman presented with leakage of vaginal fluid at 15 weeks of gestation. How do you approach the evaluation, and what is on your differential diagnosis?

The impact of response to iron therapy on maternal and neonatal outcomes among pregnant women with anemia.

BACKGROUND: Anemia during pregnancy is associated with increased risks of preterm birth, preeclampsia, cesarean delivery, and maternal morbidity. The most prevalent modifiable cause of pregnancy-associated anemia is iron deficiency. However, it is still unclear whether iron therapy can reduce the risks of adverse outcomes in women with anemia. OBJECTIVE: This study aimed to determine whether response to iron therapy among women with anemia is associated with a change in odds of adverse maternal and neonatal outcomes. STUDY DESIGN: This was a population-based cohort study (2011-2019) using an institutional database composed of obstetrical patients from 2 delivery hospitals. Patients with adequate prenatal care were classified as being anemic or nonanemic (reference). Patients with anemia were further stratified by success or failure of treatment with oral iron therapy using the American College of Obstetricians and Gynecologists criteria for anemia at the time of admission for delivery: successfully treated (Hgb≥11 g/dL) or unsuccessfully treated ("refractory;" Hgb<11 g/dL). All categories of women with anemia categories were compared with the reference group of women without anemia using chi-square and logistic regression analyses. The primary outcomes were preterm birth and preeclampsia. RESULTS: Among the 20,690 women observed, 7416 (35.8%) were anemic. Among women with anemia, 1319 (17.8%) were refractory to iron therapy, 2695 (36.3%) had a successful response to therapy, and 3402 (45.9%) were untreated. Successfully treated patients with anemia had a significant reduction in the odds of preterm birth (5.1% vs 8.3%; adjusted odds ratio, 0.59; 95% confidence interval, 0.47-0.72) and preeclampsia (5.9% vs 8.3%; adjusted odds ratio, 0.75; 95% confidence interval, 0.61-0.91). Refractory and untreated patients had significantly increased odds of preterm birth (adjusted odds ratio, 1.44 [95% confidence interval, 1.16-1.76] and 1.45 [95% confidence interval, 1.26-1.67], respectively) and preeclampsia (adjusted odds ratio, 1.54 [95% confidence interval, 1.24-1.89] and 1.44 [95% confidence interval, 1.25-1.67], respectively). All groups of women with anemia had increased odds of postpartum hemorrhage and decreased odds of delivering a small for gestational age neonate. There was no difference in composite neonatal morbidity. CONCLUSION: Successful treatment of anemia with oral iron therapy was associated with a reduction in the odds of preterm birth and preeclampsia. Women with refractory anemia had similar outcomes to those who were untreated, emphasizing the importance of monitoring response to iron therapy during pregnancy.

Placental Autophagy and Viral Replication Co-localize in Human and Non-human Primate Placentae Following Zika Virus Infection: Implications for Therapeutic Interventions.

Background: Multiple studies have shown both induction and inhibition of autophagy during Zika virus (ZIKV) infection. While some have proposed mechanisms by which autophagic dysregulation might facilitate ZIKV vertical transmission, there is a lack of in situ data in human and non-human primate models. This is an especially pertinent question as autophagy-inhibitors, such as hydroxychloroquine, have been proposed as potential therapeutic agents aimed at preventing vertical transmission of ZIKV and other RNA viruses. Objectives: Given the paucity of pre-clinical data in support of either autophagic enhancement or inhibition of placental ZIKV viral infection, we sought to assess cellular, spatial, and temporal associations between placental ZIKV infection and measures of autophagy in human primary cell culture and congenital infection cases, as well as an experimental non-human primate (marmoset, Callithrix jacchus) model. Study Design: Primary trophoblast cells were isolated from human placentae (n = 10) and infected in vitro with ZIKV. Autophagy-associated gene expression (ULK-1, BECN1, ATG5, ATG7, ATG12, ATG16L1, MAP1LC3A, MAP1LC3B, p62/SQSTM1) was then determined by TaqMan qPCR to determine fold-change with ZIKV-infection. In in vivo validation experiments, autophagy genes LC3B and p62/SQSTM1 were probed using in situ hybridization (ISH) in the placentae of human Congenital Zika Syndrome (CZS) cases (n = 3) and ZIKV-infected marmoset placenta (n = 1) and fetal tissue (n = 1). Infected and uninfected villi were compared for mean density and co-localization of autophagic protein markers. Results: Studies of primary cultured human trophoblasts revealed decreased expression of autophagy genes ATG5 and p62/SQSTM1 in ZIKV-infected trophoblasts [ATG5 fold change (±SD) 0.734-fold (±0.722), p = 0.036; p62/SQSTM1 0.661-fold (±0.666), p = 0.029]. Histologic examination by ISH and immunohistochemistry confirmed spatial association of autophagy and ZIKV infection in human congenital infection cases, as well as marmoset placental and fetal tissue samples. When quantified by densitometric data, autophagic protein LC3B, and p62/SQSTM1 expression in marmoset placenta were significantly decreased in in situ ZIKV-infected villi compared to less-infected areas [LC3B mean 0.951 (95% CI, 0.930-0.971), p = 0.018; p62/SQSTM1 mean 0.863 (95% CI, 0.810-0.916), p = 0.024]. Conclusion: In the current study, we observed that in the non-transformed human and non-human primate placenta, disruption (specifically down-regulation) of autophagy accompanies later ZIKV replication in vitro, in vivo, and in situ. The findings collectively suggest that dysregulated autophagy spatially and temporally accompanies placental ZIKV replication, providing the first in situ evidence in relevant primate pre-clinical and clinical models for the importance of timing of human therapeutic strategies aimed at agonizing/antagonizing autophagy. These studies have likely further implications for other congenitally transmitted viruses, particularly the RNA viruses, given the ubiquitous nature of autophagic disruption and dysregulation in host responses to viral infection during pregnancy.

Prone Positioning for Pregnant Women With Hypoxemia Due to Coronavirus Disease 2019 (COVID-19).

The coronavirus disease 2019 (COVID-19) pandemic has prompted expanded use of prone positioning for refractory hypoxemia. Clinical trials have demonstrated beneficial effects of early prone positioning for acute respiratory distress syndrome (ARDS), including decreased mortality. However, pregnant women were excluded from these trials. To address the need for low-cost, low-harm interventions in the face of a widespread viral syndrome wherein hypoxemia predominates, we developed an algorithm for prone positioning of both intubated and nonintubated pregnant women. This algorithm may be appropriate for a wide spectrum of hypoxemia severity among pregnant women. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is responsible for the clinical manifestations of COVID-19. This syndrome can manifest as severe pneumonia complicated by hypoxemia and ARDS. Given the current global COVID-19 pandemic, with a large number of ARDS cases, there is renewed interest in the use of prone positioning to improve oxygenation in moderate or severe hypoxemia. Among the populations who can benefit from prone positioning are pregnant women experiencing severe respiratory distress, as long as the physiologic changes and risks of pregnancy are taken into account.

Parental preferences on diagnostic imaging tests for paediatric appendicitis.

OBJECTIVES: To determine parental preferences for diagnostic imaging tests (DITs) for paediatric appendicitis, to rank the attributes impacting the DIT selection and to identify DIT attributes that would cause parents to switch their DIT. METHODS: Parents of children who had an abdominal ultrasound (US) for right lower quadrant pain were interviewed. Two DITs were compared at a time, parents were asked to indicate their preferred test and to rank its attributes according to the impact each attribute had on their selection. The strength of their preference for the chosen DIT was measured by systematically adjusting attributes of the chosen DIT until the parent changed their choice. RESULTS: Fifty parents were interviewed. For US versus CT, more parents preferred US (68%, P=0.02) with higher importance ranks for cancer risk (P<0.0001), test accuracy (P=0.04), pain during test (P=0.3), and scan length (P<0.0001); and lower ranks for sedation (P=0.02), intravenous (IV) (P<0.02), and oral contrast (P=0.06). For US versus MRI, parents preferred MRI (78%, P<0.0001) with higher importance ranks for accuracy (P=0.2), pain during test (P=0.06), and scan length (P=0.06); and lower for noise (P<0.0001), claustrophobia (P<0.0001), use of IV contrast (P=0.06), and sedation (P=0.2). CONCLUSION: US and MRI were the DIT preferred by parents for the investigation of acute paediatric appendicitis.

Duration of labor and maternal and neonatal morbidity.

BACKGROUND: Labor dystocia has been identified as a contributor to the rising cesarean delivery rate in the United States. Allowing more time for vaginal delivery, while being cognizant of maternal and neonatal outcomes, has been identified as a possible strategy to lower cesarean delivery rates. OBJECTIVE: This study aimed to characterize the relationship between the duration of active phase and second-stage labor and maternal and neonatal morbidity. STUDY DESIGN: We present a secondary analysis of the Consortium on Safe Labor project. From labors of 66,940 nonanomalous nulliparous term singleton vertex gestations, we excluded labors for which active phase (≥6 cm dilation) or second stage durations could not be calculated and from sites that did not report determinants of morbidity. For each duration of active phase or second stage labor (grouped in 1-hour increments), the adjusted maternal and neonatal composite morbidity was estimated by and compared with the morbidity associated with a duration <1 hour total and a duration of 1 hour shorter. RESULTS: After exclusions, 48,144 deliveries remained. In adjusted models, compared with labor durations <1 hour total, maternal composite morbidity was significantly higher across active phase and second stage durations (both P<.001); neonatal composite morbidity was higher across the second stage (P<.001), but not active phase (P=.07) duration. These relationships appear linear with no apparent inflection point, and morbidity increases more rapidly. When compared with labor durations 1 hour shorter, significant differences persisted in maternal and neonatal composite morbidity in second stage labor only through 4 and 3 hours, respectively. CONCLUSION: Maternal and neonatal composite morbidity is greater with longer durations of active and second stage labor; however, no clear cutoff point was determined to suggest truncation of either stage of labor for reasons of morbidity. In addition, incrementally higher morbidities that were noted vs duration <1 hour total were obscured when comparison was made with labors 1 hour shorter, which suggests that focusing on short differences in duration of labor may mask important underlying trends.

Characterization and effect of metal ions on the formation of the Thermus thermophilus Sco mixed disulfide intermediate.

The Sco protein from Thermus thermophilus has previously been shown to perform a disulfide bond reduction in the CuA protein from T. thermophilus, which is a soluble protein engineered from subunit II of cytochrome ba 3 oxidase that lacks the transmembrane helix. The native cysteines on TtSco and TtCuA were mutated to serine residues to probe the reactivities of the individual cysteines. Conjugation of TNB to the remaining cysteine in TtCuA and subsequent release upon incubation with the complementary TtSco protein demonstrated the formation of the mixed disulfide intermediate. The cysteine of TtSco that attacks the disulfide bond in the target TtCuA protein was determined to be TtSco Cysteine 49. This cysteine is likely more reactive than Cysteine 53 due to a higher degree of solvent exposure. Removal of the metal binding histidine, His 139, does not change MDI formation. However, altering the arginine adjacent to the reactive cysteine in Sco (Arginine 48) does alter the formation of the MDI. Binding of Cu2+ or Cu+ to TtSco prior to reaction with TtCuA was found to preclude formation of the mixed disulfide intermediate. These results shed light on a mechanism of disulfide bond reduction by the TtSco protein and may point to a possible role of metal binding in regulating the activity. IMPORTANCE: The function of Sco is at the center of many studies. The disulfide bond reduction in CuA by Sco is investigated herein and the effect of metal ions on the ability to reduce and form a mixed disulfide intermediate are also probed.

Accuracy of magnetic resonance imaging for measuring maturing cartilage: A phantom study.

OBJECTIVES: To evaluate the accuracy of magnetic resonance imaging measurements of cartilage tissue-mimicking phantoms and to determine a combination of magnetic resonance imaging parameters to optimize accuracy while minimizing scan time. METHOD: Edge dimensions from 4 rectangular agar phantoms ranging from 10.5 to 14.5 mm in length and 1.25 to 5.5 mm in width were independently measured by two readers using a steel ruler. Coronal T1 spin echo (T1 SE), fast spoiled gradient-recalled echo (FSPGR) and multiplanar gradient-recalled echo (GRE MPGR) sequences were used to obtain phantom images on a 1.5-T scanner. RESULTS: Inter- and intra-reader reliability were high for both direct measurements and for magnetic resonance imaging measurements of phantoms. Statistically significant differences were noted between the mean direct measurements and the mean magnetic resonance imaging measurements for phantom 1 when using a GRE MPGR sequence (512x512 pixels, 1.5-mm slice thickness, 5:49 min scan time), while borderline differences were noted for T1 SE sequences with the following parameters: 320x320 pixels, 1.5-mm slice thickness, 6:11 min scan time; 320x320 pixels, 4-mm slice thickness, 6:11 min scan time; and 512x512 pixels, 1.5-mm slice thickness, 9:48 min scan time. Borderline differences were also noted when using a FSPGR sequence with 512x512 pixels, a 1.5-mm slice thickness and a 3:36 min scan time. CONCLUSIONS: FSPGR sequences, regardless of the magnetic resonance imaging parameter combination used, provided accurate measurements. The GRE MPGR sequence using 512x512 pixels, a 1.5-mm slice thickness and a 5:49 min scan time and, to a lesser degree, all tested T1 SE sequences produced suboptimal accuracy when measuring the widest phantom.

Accuracy of magnetic resonance imaging for measuring maturing cartilage: A phantom study

OBJECTIVES: To evaluate the accuracy of magnetic resonance imaging measurements of cartilage tissue-mimicking phantoms and to determine a combination of magnetic resonance imaging parameters to optimize accuracy while minimizing scan time. METHOD: Edge dimensions from 4 rectangular agar phantoms ranging from 10.5 to 14.5 mm in length and 1.25 to 5.5 mm in width were independently measured by two readers using a steel ruler. Coronal T1 spin echo (T1 SE), fast spoiled gradient-recalled echo (FSPGR) and multiplanar gradient-recalled echo (GRE MPGR) sequences were used to obtain phantom images on a 1.5-T scanner. RESULTS: Inter- and intra-reader reliability were high for both direct measurements and for magnetic resonance imaging measurements of phantoms. Statistically significant differences were noted between the mean direct measurements and the mean magnetic resonance imaging measurements for phantom 1 when using a GRE MPGR sequence (512x512 pixels, 1.5-mm slice thickness, 5:49 min scan time), while borderline differences were noted for T1 SE sequences with the following parameters: 320x320 pixels, 1.5-mm slice thickness, 6:11 min scan time; 320x320 pixels, 4-mm slice thickness, 6:11 min scan time; and 512x512 pixels, 1.5-mm slice thickness, 9:48 min scan time. Borderline differences were also noted when using a FSPGR sequence with 512x512 pixels, a 1.5-mm slice thickness and a 3:36 min scan time. CONCLUSIONS: FSPGR sequences, regardless of the magnetic resonance imaging parameter combination used, provided accurate measurements. The GRE MPGR sequence using 512x512 pixels, a 1.5-mm slice thickness and a 5:49 min scan time and, to a lesser degree, all tested T1 SE sequences produced suboptimal accuracy when measuring the widest phantom.