Freeze-fracture study of melanosomes in mammalian epidermis and the distribution of intramembrane particles in the melanosome membrane

Summary The ultrastructure of melanosomes in mammalian epidermis has been studied using the freeze-fracture technique. The internal structure of the melanosome, as seen in cross-fractured granules, consists of a very fine particulate matter. There is no evidence of an internal membranous structure in melanosomes, indicating that the internal matrix which is characteristic of ultrathin sectioned material most likely represents cross-linked protein fibers.Fracture en-face of the melanosome limiting membrane reveals a random distribution of intramembrane particles on both the P- and E-faces of the membrane. There is a significantly higher density of IMPs on the P-face. The IMPs of the melanosome membrane may be involved in (a) selective passage of ions through the membrane, (b) membrane transducing events, and/or (c) anchoring sites for cytoplasmic fibrils and microfilaments.Research supported by USPHS Grant AM-20669 from the National Institute of Arthritis, Metabolism, and Digestive Diseases     

Comparing sulindac with indomethacin for closure of ductus arteriosus in preterm infants

Objectives: A prospective study comparing the efficiacy and side-effects of oral sulindac with intravenous indomethacin in clinically stable preterm infants (<1750 g) requiring non-invasive closure of haemodynamically significant patent ductus arteriosus.
Methodology: As maturity and birthweight are the two major determinants of ductal closure, infants were matched as closely as possible for these parameters. An eligible patient was first assigned to the sulindac group and a subsequent patient with similar gestational age (± 1 week) and birthweight (±100 g) to the previously recruited infant would automatically receive indomethacin. A total of eight infants were enrolled in each group.
Results: The ductus arteriosus was successfully closed in all eight infants receiving indomethacin, and in seven of eight infants receiving sulindac. No significant differences were found with regards to the ductal size between the two groups at diagnosis or on each of the consecutive days of treatment ( P >0.25). More renal adverse effects were encountered in the indomethacin group. Significant differences in changes from baseline value for urine output, plasma sodium, urea and creatinine concentrations were noted at 24, 48 and 72 h after commencement of treatment between the two groups ( P <0.05). All the parameters returned to normal or pre-treatment levels 48 h after stopping therapy. Unexpectedly, severe gastrointestinal complications were encountered in the sulindac group.
Conclusions: Sulindac is capable of promoting ductal constriction in clinically stable preterm infants without compromising the renal function. The spectrum of gastrointestinal complications observed in sulindac treated infants were similar to those described for indomethacin. The use of sulindac for ductal closure in the preterm infant should remain experimental.     

Use of Artificial Intelligence for Reducing Unnecessary Recalls at Screening Mammography: A Simulation Study

ObjectiveTo conduct a simulation study to determine whether artificial intelligence (AI)-aided mammography reading can reduce unnecessary recalls while maintaining cancer detection ability in women recalled after mammography screening.Materials and MethodsA retrospective reader study was performed by screening mammographies of 793 women (mean age ± standard deviation, 50 ± 9 years) recalled to obtain supplemental mammographic views regarding screening mammography-detected abnormalities between January 2016 and December 2019 at two screening centers. Initial screening mammography examinations were interpreted by three dedicated breast radiologists sequentially, case by case, with and without AI aid, in a single session. The area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and recall rate for breast cancer diagnosis were obtained and compared between the two reading modes.ResultsFifty-four mammograms with cancer (35 invasive cancers and 19 ductal carcinomas in situ) and 739 mammograms with benign or negative findings were included. The reader-averaged AUC improved after AI aid, from 0.79 (95% confidence interval [CI], 0.74–0.85) to 0.89 (95% CI, 0.85–0.94) (p < 0.001). The reader-averaged specificities before and after AI aid were 41.9% (95% CI, 39.3%–44.5%) and 53.9% (95% CI, 50.9%–56.9%), respectively (p < 0.001). The reader-averaged sensitivity was not statistically different between AI-unaided and AI-aided readings: 89.5% (95% CI, 83.1%–95.9%) vs. 92.6% (95% CI, 86.2%–99.0%) (p = 0.053), although the sensitivities of the least experienced radiologists before and after AI aid were 79.6% (43 of 54 [95% CI, 66.5%–89.4%]) and 90.7% (49 of 54 [95% CI, 79.7%–96.9%]), respectively (p = 0.031). With AI aid, the reader-averaged recall rate decreased by from 60.4% (95% CI, 57.8%–62.9%) to 49.5% (95% CI, 46.5%–52.4%) (p < 0.001).ConclusionAI-aided reading reduced the number of recalls and improved the diagnostic performance in our simulation using women initially recalled for supplemental mammographic views after mammography screening.     

Postpartum hemorrhage with pelvic arterial embolization,study of 33 cases

Objective: To describe our cases of postpartum hemorrhage (PPH) with pelvic arterial embolization (PAE).

Material and methods: All patients with PPH who underwent PAE in our center in the interval 2011–1016 were retrospectively studied, evaluating the technical procedure, clinical results, and subsequent fertility.

Results: There were 33 cases of PPH with PAE. The majority occurred in primiparous women (N?=?22, 66.6%) who delivered vaginally (N?=?20, 61%). In addition, most PPH with PAE cases had an early onset (N?=?26, 79%) and were caused by uterine atony (N?=?14, 42.4%). Success of PAE occurred in 27 (81.8%) cases and a satisfactory clinical follow-up was the rule, with 21 (64%) women recovering their normal menstruation, and six (18.2%) becoming pregnant in the following years.

Conclusions: PAE is a safe and efficacious technique with minor complications. Moreover, it allows conservation of the uterus with preservation of fertility.     

Community‐based health literacy focused intervention for cervical cancer control among Black women living with human immunodeficiency virus: A randomized pilot trial

BackgroundHealth literacy plays an essential role in how individuals process health information to make decisions about health behaviours including cancer screening. Research is scarce to address health literacy as a strategy to improve cancer screening participation among women living with human immunodeficiency virus (HIV), particularly Black women who, despite the heavy burden of cervical cancer, report consistently low screening rates.AimTo assess the feasibility, acceptability and preliminary efficacy of a health literacy‐focused intervention called CHECC‐uP—Community‐based, HEalth literacy focused intervention for Cervical Cancer control—among women living with HIV.MethodsWe conducted a community‐based, single‐blinded randomized pilot trial. A total of 123 eligible women were enrolled and randomized to one of two conditions, control (i.e., cervical cancer brochure) or intervention (cervical cancer brochure plus 30–60 min health literacy‐focused education followed by monthly phone counselling and navigation assistance for 6 months). Study assessments were done at baseline, 3 and 6 months. The final analysis sample included 58 women who completed all data points and whose Papanicolaou (Pap) test status was confirmed by medical records.ResultsAll intervention participants who completed the programme would recommend the CHECC‐uP to other women living with HIV. However, adherence in the experimental conditions was low (49.6% attrition rate including 20 women who dropped out before the intervention began) due, in large part, to phone disconnection. Those who had received the intervention had a significantly higher Pap test rate compared to women in the control group at 6 months (50% vs. 21.9%, p = .025). Participation in the intervention programme was associated with improved health literacy and other psychosocial outcomes at 3 months but the trend was attenuated at 6 months.ConclusionsThe CHECC‐uP was highly acceptable and led to improved Pap testing rates among Black women living with HIV. Future research should consider addressing social determinants of health such as phone connectivity as part of designing a retention plan targeting low‐income Black women living with HIV.ImplicationsThe findings should be incorporated into a future intervention framework to fulfil the unmet needs of Black women living with HIV to facilitate their decision‐making about Pap test screening.Patient or Public ContributionNineteen community members including women living with HIV along with HIV advocates and care providers participated in four focus groups to develop cervical cancer screening decision‐relevant information and the health literacy intervention. Additionally, a community advisory board was involved to provide guidance in the general design and conduct of the study.