Loss of the Merlin tumor suppressor and activation of the Hippo signaling pathway play major roles in the control of cell proliferation and tumorigenesis. We have identified completely novel roles ...for Merlin and the Hippo pathway effector Yes-associated protein (YAP) in the control of Schwann cell (SC) plasticity and peripheral nerve repair after injury. Injury to the peripheral nervous system (PNS) causes a dramatic shift in SC molecular phenotype and the generation of repair-competent SCs, which direct functional repair. We find that loss of Merlin in these cells causes a catastrophic failure of axonal regeneration and remyelination in the PNS. This effect is mediated by activation of YAP expression in Merlin-null SCs, and loss of YAP restores axonal regrowth and functional repair. This work identifies new mechanisms that control the regenerative potential of SCs and gives new insight into understanding the correct control of functional nerve repair in the PNS.
The effect of gull predation on sympatric seabirds has garnered much attention and management action in recent decades. In Witless Bay, Newfoundland, Canada, gulls depredate significant numbers of ...Leach’s Storm-petrels (Hydrobates leucorhous) annually. We quantified this predation on Gull Island in Witless Bay, and its effects on the storm-petrel population, by estimating the annual gull predation rate using strip transects to count storm-petrel carcasses and predicting storm-petrels’ population growth rate by repeating an island-wide breeding census. Using methods that account for island topography, we found that the Leach’s Storm-petrel breeding population on Gull Island declined to roughly 180,000 pairs in 2012 (95% CI: 130,000–230,000), a decrease of 6% per year since the last census in 2001 (352,000 pairs). Based on carcass counts, gulls, mostly American Herring Gulls (Larus argentatus smithsonianus), depredated 118,000–143,000 Leach’s Storm-petrels in 2012. Studies of storm-petrel recruitment, the contribution of the large non-breeding component of the population to gulls’ diets, and the consequences of gulls’ storm-petrel diet on the gulls themselves are needed to better predict the trajectory of both species into the future.
Introduction
Women with a prior stillbirth or a history of recurrent first trimester miscarriages are at increased risk of adverse pregnancy outcomes. However, little is known about the impact of a ...second trimester pregnancy loss on subsequent pregnancy outcome. This review investigated if second trimester miscarriage or termination for medical reason or fetal anomaly (TFMR/TOPFA) is associated with future adverse pregnancy outcomes.
Material and methods
A systematic review of observational studies was conducted. Eligible studies included women with a history of a second trimester miscarriage or termination for medical reasons and their pregnancy outcomes in the subsequent pregnancy. Where comparative studies were identified, studies which compared subsequent pregnancy outcomes for women with and without a history of second trimester loss or TFMR/TOPFA were included. The primary outcome was livebirth, and secondary outcomes included: miscarriage (first and second trimester), termination of pregnancy, fetal growth restriction, cesarean section, preterm birth, pre‐eclampsia, antepartum hemorrhage, stillbirth and neonatal death. Studies were excluded if exposure was nonmedical termination or if related to twins or higher multiple pregnancies. Electronic searches were conducted using the online databases (MEDLINE, Embase, PubMed and The Cochrane Library) and searches were last updated on June 16, 2023. Risk of bias was assessed using the Newcastle‐Ottawa scale. Where possible, meta‐analysis was undertaken. PROSPERO registration: CRD42023375033.
Results
Ten studies were included, reporting on 12 004 subsequent pregnancies after a second trimester pregnancy miscarriage. No studies were found on outcomes after second trimester TFMR/TOPFA. Overall, available data were of “very low quality” using GRADE assessment. Meta‐analysis of cohort studies generated estimated outcome frequencies for women with a previous second trimester loss as follows: live birth 81% (95% CI: 64–94), miscarriage 15% (95% CI: 4–30, preterm birth 13% 95% CI: 6–23).The pooled odds ratio for preterm birth in subsequent pregnancy after second trimester loss in case–control studies was OR 4.52 (95% CI: 3.03–6.74).
Conclusions
Very low certainty evidence suggests there may be an increased risk of preterm birth in a subsequent pregnancy after a late miscarriage. However, evidence is limited. Larger, higher quality cohort studies are needed to investigate this potential association.
Very low certainty evidence suggests there may be an increased risk of preterm birth after a late miscarriage. However, evidence is very limited, and this association requires further study using larger cohort studies.
OBJECTIVE To compare results of anterior segment angiography of ophthalmically normal eyes of goats, sheep, and alpacas performed by use of indocyanine green (ICG) and sodium fluorescein (SF). ...ANIMALS 10 female goats (mean ± SD age, 6.8 ± 1.7 years), 10 female sheep (3.0 ± 2.2 years), and 10 alpacas (7 females and 3 males; 6.8 ± 3.8 years). PROCEDURES A catheter was aseptically placed into a jugular vein. Each animal was anesthetized and properly positioned, and 0.25% ICG was administered. Images were obtained by use of an adaptor system consisting of a modified digital single-lens reflex camera, camera adaptor, and camera lens. Images were obtained at a rate of 3 images/s for the 60 seconds immediately after ICG administration and then at 2, 3, 4, and 5 minutes after administration. Ten minutes later, 10% SF was administered IV and images were obtained in a similar manner. RESULTS Angiography with ICG provided visual examination of the arterial, capillary, and venous phases in all species. Visual examination of the iris vasculature by use of SF was performed in goats and sheep but was not possible in the alpacas because of iridal pigmentation. Extravasation of SF was a common finding in sheep and alpacas but not in goats. No adverse events were detected. CONCLUSIONS AND CLINICAL RELEVANCE Quality angiographic images of the anterior segment were obtainable after IV administration of ICG to goats, sheep, and alpacas. This may provide a useful imaging modality for ocular research in these animal species.
Objective
To assess the reproducibility and repeatability of an optical coherence tomography (OCT) device for imaging the optic nerve region of normal canines.
Animals studied
Twelve clinically ...healthy beagles.
Procedures
All animals were anesthetized, and an OCT device was used to image the optic disk region. Total disk area and retinal nerve fiber layer (NFL) thickness in eight segments were obtained from each image. Images were collected by two operators in succession and each operator took five scans, repositioning the device between measurements. B‐scan segmentations and disk outlines were subsequently redrawn to obtain manual measurements, allowing for comparisons between automated measurements.
Results
Operator 1 had a mean (±SD) NFL thickness (automatic) and disk area of 73.38 ± 7.41 μm and 3.69 ± 0.52 mm², while operator 2 had 74.27 ± 7.33 μm and 3.67 ± 0.51 mm², respectively. With manual corrections, operator 1 had a NFL thickness and disk area of 86.19 ± 8.26 μm and 3.74 ± 0.68 mm², while operator 2 had 86.85 ± 6.91 μm and 3.81 ± 0.56 mm², respectively. Operators did not obtain significantly different values for any region. Intraclass correlation ranged from 0.33 to 0.97 (average 0.78). Coefficient of variation ranged from 8.8 to 36.2%.
Conclusion
The OCT device demonstrated high inter‐rater reliability. Intrarater reliability was strong for disk area and total NFL; however, the segmental regions demonstrated a higher degree of variability. Manual and automated measurements were significantly different for total NFL and some segmental regions; therefore, users should consistently use one method for longitudinal studies.
OBJECTIVE To determine corneal thickness of eyes of healthy goats, sheep, and alpacas by use of a portable spectral-domain optical coherence tomography (SD-OCT) device and evaluate intraoperator ...reliability for measurements. ANIMALS 11 female goats, 10 female sheep, and 11 (4 males and 7 females) alpacas. PROCEDURES Each animal was sedated, and gentle manual restraint was used to ensure proper positioning of the head and globe. Corneal pachymetry was performed (in triplicate) with a portable SD-OCT device on both eyes of each animal. All corneal measurements were obtained manually by use of the integrated caliper function. Corneal epithelial thickness (CET), corneal stromal thickness (CST), Descemet membrane thickness (DMT), and total corneal thickness (TCT) were measured twice on each image, and a mean value was calculated. RESULTS Mean ± SD values for CET, CST, DMT, and TCT were 96.1 ± 5.0 μm, 486.0 ± 10.3 μm, 36.8 ± 4.8 μm, and 616.9 ± 7.1 μm, respectively, for the goats; 111.6 ± 5.7 μm, 599.8 ± 10.0 μm, 31.0 ± 4.5 μm, and 741.1 ± 9.9 μm, respectively, for the sheep; and 147.4 ± 5.7 μm, 446.1 ± 7.4 μm, 44.5 ± 5.0 μm, and 634.8 ± 6.2 μm, respectively, for the alpacas. Intraclass correlations ranged from 0.49 to 0.83 for CET, CST, and TCT and from 0.13 to 0.36 for DMT. CONCLUSIONS AND CLINICAL RELEVANCE SD-OCT provided manual measurement of corneal thickness (CET, CST, and TCT) with clinically acceptable intraoperator reliability for eyes of healthy goats, sheep, and alpacas.
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