Adult mammary tissue has been considered "resting" with minimal morphological change. Here, we reveal the dynamic nature of the nulliparous murine mammary gland. We demonstrate specific changes at the morphological and cellular levels, and uncover their relationship with the murine estrous cycle and physiological levels of steroid hormones. Differences in the numbers of higher-order epithelial branches and alveolar development led to extensive mouse-to-mouse mammary variations. Morphology (assigned grades 0-3) ranged from a complete lack of alveoli to the presence of numerous alveoli emanating from branches. Morphological changes were driven by epithelial proliferation and apoptosis, which differed between ductal versus alveolar structures. Proliferation within alveolar epithelium increased as morphological grade increased. Extensive alveolar apoptosis was restricted to tissue exhibiting grade 3 morphology, and was approximately 14-fold higher than at all other grades. Epithelial proliferation and apoptosis exhibited a positive relationship with serum levels of progesterone, but not with 17beta-estradiol. Compared with other estrous stages, diestrus was unique in that the morphological grade, epithelial proliferation, apoptosis, and progesterone levels all peaked at this stage. The regulated tissue remodeling of the mammary gland was orchestrated with mRNA changes in specific matrix metalloproteinases (MMP-9 and MMP-13) and specific tissue inhibitors of metalloproteinases (TIMP-3 and TIMP-4). We propose that the cyclical turnover of epithelial cells within the adult mammary tissue is a sum of spatial and functional coordination of hormonal and matrix regulatory factors.

Background/aimsA retrospective consecutive case series to evaluate the efficacy of re-operation in patients with persistent or recurrent idiopathic full-thickness macular hole after initial surgery with internal limiting membrane peel (ILM).Methods491 patients underwent surgery for full-thickness macular hole from January 2004 to November 2007. Fifty-five patients either did not close or reopened during the follow-up period. Thirty patients with initial ILM peel underwent repeat surgery involving vitrectomy, enlargement of ILM rhexis and gas tamponade.ResultsAnatomical closure rate was 88.8% for primary surgery and 46.7% (14/30) for re-operation. There was a statistically significant improvement in overall best corrected visual acuity (BCVA) from re-operation baseline BCVA (p=0.02) within 1 year. For holes that did not close after the second surgery, visual acuity did not worsen.ConclusionRe-operation has a reduced success rate of anatomical closure. However, BCVA is statistically significantly improved from re-operation baseline, so even though we cannot return vision to pre-pathological baseline, re-operation can improve on this new baseline.

IMPORTANCE Retinal displacement following rhegmatogenous retinal detachment repair may have consequences for visual function. It is important to know whether surgical technique is associated with risk of displacement.OBJECTIVE To compare retinal displacement following rhegmatogenous retinal detachment repair with pneumatic retinopexy (PR) vs pars plana vitrectomy (PPV). INTERVENTIONS OR EXPOSURESFundus autofluorescence images were assessed by graders masked to surgical technique. DESIGN, SETTING, AND PARTICIPANTSA multicenter retrospective consecutive case series in Canada and the UK. A total of 238 patients (238 eyes) with rhegmatogenous retinal detachments treated with PR or PPV who underwent fundus autofluorescence imaging from November 11, 2017, to March 22, 2019, were included. MAIN OUTCOMES AND MEASURESProportion of patients with retinal displacement detected by retinal vessel printings on fundus autofluorescence imaging in PR vs PPV. RESULTSOf the 238 patients included in the study, 144 were men (60.5%) and 94 were women (39.5%); mean (SD) age was 62.0 (11.0) years. Of the 238 eyes included in this study, 114 underwent PR (47.9%) and 124 underwent PPV (52.1%) as the final procedure to achieve reattachment. Median time from surgical procedure to fundus autofluorescence imaging was 3 months (interquartile range, 1-5 months). Baseline characteristics in both groups were similar. The proportion of eyes with retinal vessel printing on fundus autofluorescence was 7.0% for PR (8 of 114) and 44.4% for PPV (55 of 124) (37.4% difference; 95% CI, 27.4%-47.3%; P < .001). Analysis based on the initial procedure found that 42.4% (42 of 99) of the eyes in the PPV group vs 15.1% (21 of 139) of the eyes in the PR group (including 13 PR failures with subsequent PPV) had displacement (27.3% difference; 95% CI, 15.9%-38.7%; P < .001). Among eyes with displacement in the macula, the mean (SD) displacement was 0.137 (0.086) mm (n = 6) for PR vs 0.297 (0.283) mm (n = 52) for PPV (0.160-mm difference; 95% CI, 0.057-0.263 mm; P = .006). Mean postoperative logMAR visual acuity was 0.31 (0.32) (n = 134) (Snellen equivalent 20/40) in eyes that initially underwent PR and 0.56 (0.42) (n = 84) (Snellen equivalent 20/72) in eyes that had PPV (−0.25 difference; 95% CI, −0.14 to −0.35; P < .001). Among eyes with displacement, mean postoperative logMAR visual acuity was 0.42 (0.42) (n = 20) (Snellen equivalent 20/52) in those that initially underwent PR and 0.66 (0.47) (n = 33) (Snellen equivalent 20/91) in those that initially underwent PPV (−0.24 difference; 95% CI, −0.48 to 0.01; P = .07). CONCLUSIONS AND RELEVANCEThese findings suggest that retinal displacement occurs more frequently and is more severe with PPV vs PR when considering the initial and final procedure used to achieve retinal reattachment. Recognizing the importance of anatomic integrity by assessing retinal displacement following reattachment may lead to refinements in vitreoretinal surgery techniques.