Potency of myopic defocus in spectacle lens compensation

PURPOSE: Previous studies have shown that chick eyes compensate for positive or negative lenses worn for brief periods if the chicks are in darkness the remainder of the time. This study was undertaken to determine whether chicks can compensate for brief periods of lens wear if given unrestricted vision the remainder of the time. Previous studies have also shown that chick eyes alternately wearing positive and negative lenses for brief periods compensate for the positive lenses. The current study sought to determine whether brief periods of positive lens wear can outweigh daylong wearing of negative lenses. METHODS: Chicks wore +6 D or +10 D lenses for between 8 and 60 min/d, in two to six periods and wore either no lenses or negative lenses for the remainder of the 12-hour daylight period. Refraction and ultrasound biometry were performed before and after the 3-day-long experiments. RESULTS: Wearing positive lenses for as little as 12 min/d (six periods of 2 minutes) with unrestricted vision the remainder of the time caused eyes to become hyperopic and reduced the rate of ocular elongation. These effects also occurred when the scene viewed was beyond the far point of the lens-wearing eye and thus was myopically blurred. Even when chicks wore negative lenses for the entire day except for 8 minutes of wearing positive lenses, the eyes compensated for the positive lenses, as though the negative lenses had not been worn. When chicks wore binocular negative lenses for the entire day except for 8 minutes of wearing a positive lens on one eye and a plano lens on the other, the eye wearing the positive lens became less myopic than the eye wearing the plano lens. CONCLUSIONS: Brief periods of myopic defocus imposed by positive lenses prevent myopia caused by daylong wearing of negative lenses. This implies that periods of myopic and hyperopic defocus do not add linearly. If children are like chicks and if the hyperopic defocus of long daily periods of reading predisposes a child to myopia, regular, brief interruptions of reading might have use as a prophylaxis against progression of myopia.     

Abnormal activation of the social brain during face perception in autism

ASD involves a fundamental impairment in processing social-communicative information from faces. Several recent studies have challenged earlier findings that individuals with autism spectrum disorder (ASD) have no activation of the fusiform gyrus (fusiform face area, FFA) when viewing faces. In this study, we examined activation to faces in the broader network of face-processing modules that comprise what is known as the social brain. Using 3T functional resonance imaging, we measured BOLD signal changes in 10 ASD subjects and 7 healthy controls passively viewing nonemotional faces. We replicated our original findings of significant activation of face identity-processing areas (FFA and inferior occipital gyrus, IOG) in ASD. However, in addition, we identified hypoactivation in a more widely distributed network of brain areas involved in face processing [including the right amygdala, inferior frontal cortex (IFC), superior temporal sulcus (STS), and face-related somatosensory and premotor cortex]. In ASD, we found functional correlations between a subgroup of areas in the social brain that belong to the mirror neuron system (IFC, STS) and other face-processing areas. The severity of the social symptoms measured by the Autism Diagnostic Observation Schedule was correlated with the right IFC cortical thickness and with functional activation in that area. When viewing faces, adults with ASD show atypical patterns of activation in regions forming the broader face-processing network and social brain, outside the core FFA and IOG regions. These patterns suggest that areas belonging to the mirror neuron system are involved in the face-processing disturbances in ASD.     

Mapping the social and physical contexts of physical activity across adolescence using ecological momentary assessment

BACKGROUND: Research has sought to understand how environmental factors influence adolescent physical activity, yet little is known about where and with whom adolescents are physically active. PURPOSE: This study used electronic ecological momentary assessment (e.EMA) to map the social and physical contexts of exercise and walking across adolescence. Differences in physical activity contexts by gender, grade in school, day of the week, and season were examined. METHODS: Twice a year between 9th and 12th grade, 502 adolescents (51% female) of mixed ethnicity (55% White) participated in 4-day e.EMA intervals (Thursday-Sunday) where their primary activity (e.g., exercise, TV, homework), social company (e.g., friends, family, class), and physical location (e.g., home, school, outdoors) were assessed every 30 (+/-10) min during waking hours. RESULTS: Overall, greater proportions of exercise and walking were reported with friends, outdoors, and at school. However, boys were more likely to report exercising and walking in outdoor locations than girls. Exercising with classmates, family, and at school decreased across high school. Walking with family, friends, and outdoors also decreased. On weekdays compared to weekends, students reported a greater proportion of their exercise and walking at school. Students were more likely to report exercising and walking outdoors in the fall and the spring than in the winter. CONCLUSION: e.EMA showed that the social and physical contexts of adolescent exercise and walking vary as a function of gender, grade in school, day of the week, and season. Understanding the contexts of physical activity during the high school years can be helpful in designing interventions during adolescence.     

Incidence of complications in 25-gauge transconjunctival sutureless vitrectomy based on the surgical indications.

BACKGROUND AND OBJECTIVE: The complications of 25-gauge transconjunctival sutureless vitrectomy based on the surgical indications were reviewed. PATIENTS AND METHODS: Thirty-eight patients underwent 25-gauge transconjunctival sutureless vitrectomy. Indications for vitrectomy, preoperative and postoperative best-corrected visual acuity, preoperative and postoperative intraocular pressure, and any intraoperative or postoperative complications were recorded. RESULTS: Complications included the need to suture a leaking sclerotomy intraoperatively in four eyes (9%), all of which involved oil removal; postoperative hypotony with choroidals in two eyes (5%); mild progression of nuclear sclerotic cataract in one eye (2% of all eyes, 4% of phakic eyes); the need to switch to 20-gauge pars plana vitrectomy in one eye (2%); corneal abrasion in one eye (2%); and retinal detachment in one eye (2%). Sclerotomy leakage and hyopotony with choroidals were only encountered in cases involving previously vitrectomized eyes, whereas none of the eyes without previous vitrectomy had leakage-related complications. CONCLUSIONS: Previously vitrectomized eyes have a higher incidence of complications related to postoperative leakage, possibly due to the lack of plugging effect of peripheral vitreous on the unsutured sclerotomy. One should consider suturing any leaking sclerotomy at the conclusion of surgery involving previously vitrectomized eyes.     

Does gender affect neonatal hyperbilirubinemia in low-birth-weight infants?

BACKGROUND: Neonatal mortality and morbidity are gender-biased in low-birth-weight (LBW) infants. The male disadvantage theory has been suggested to be responsible for these maturational differences. OBJECTIVE: To examine the impact of gender on neonatal hyperbilirubinemia. DESIGN/METHODS: A retrospective observational study. Data on all LBW infants admitted to George Washington University neonatal intensive care unit and surviving for >48 hrs from January 1992 to March 2003 were analyzed. Males and females were compared for gestational age, birth weight, race, Apgar scores at 1 and 5 mins, peak bilirubin levels, sepsis, and intraventricular hemorrhage (IVH). Significant differences were entered in a regression model to detect the influence of gender on bilirubin (Bili). Analysis was repeated after stratification of infants into: group A, <1000 g; group B, 1000-1499 g; and group C, 1500-2499 g. RESULTS: A total of 840 infants were included in this study. When comparing males (n = 407) with females (n = 433), significant differences were detected in birth weight (1,539 +/- 541 vs. 1,428 +/- 549 g; p = .003), IVH (14.2% vs. 9%; p = .025), and Bili (10.1 +/- 3.0 vs. 9.2 +/- 2.8 mg%; p < .001). No differences were detected in gestational age, sepsis, or Apgar 1 and 5. Difference in Bili for the entire group remained significant in the regression model (regression coefficient [RC] = 0.79 +/- 0.22; p < .001). In subgroup analyses: group A Bili (8.4 +/- 2.3 vs. 8.0 +/- 2.0; p = .14) and group B Bili (9.0 +/- 2.1 vs. 9.2 +/- 2.2; p = .51) did not differ in bivariate or multivariate analyses. In group C, Bili was (11.3 +/- 3.1 vs. 10.1 +/- 3.3; p < .001) and remained the only significant difference in the regression model (RC = 1.19 +/- 0.37; p = .001). CONCLUSIONS: Bili in LBW infants is significantly higher in males when compared with females. After stratification to birth weight subgroups, significance is retained in the 1500- to 2499-g group after logistic regression analysis. Bili levels in infants <1500 g are influenced more significantly by factors other than gender, such as sepsis and IVH.     

Steroid use for refractory hypotension in congenital diaphragmatic hernia

Purpose

Guidelines for diagnosis and treatment of adrenal insufficiency (AI) in newborns with congenital diaphragmatic hernia (CDH) are poorly defined.

Methods

From 2002 to 2016, 155 infants were treated for CDH at our institution. Patients with shock refractory to vasopressors (clinically diagnosed AI) were treated with hydrocortisone (HC). When available, random cortisol levels <10 μg/dL were considered low. Outcomes were compared between groups.

Results

Hydrocortisone was used to treat AI in 34% (53/155) of patients. That subset of patients was demonstrably sicker, and mortality was expectedly higher for those treated with HC (37.7 vs. 17.6%, p = 0.0098). Of the subset of patients with random cortisol levels measured before initiation of HC, 67.7% (21/31) had low cortisol levels. No significant differences were seen in survival between the high and low groups, but mortality trended higher in patients with high cortisol levels that received HC. After multivariate analysis, duration of HC stress dose administration was associated with increased risk of mortality (OR 1.11, 95% CI 1.02–1.2, p = 0.021), and total duration of HC treatment was associated with increased risk of sepsis (OR 1.04, 95% CI 1.005–1.075, p = 0.026).

Conclusion

AI is prevalent amongst patients with CDH, but prolonged treatment with HC may increase risk of mortality and sepsis.

     

Mycophenolate mofetil monotherapy in liver transplant recipients

Kriss M, Sotil EU, Abecassis M, Welti M, Levitsky J. Mycophenolate mofetil monotherapy in liver transplant recipients.
Clin Transplant 2011: 25: E639–E646. © 2011 John Wiley & Sons A/S. Abstract:  Introduction: Complete conversion of calcineurin inhibitor (CNI) immunosuppressant therapy to non‐nephrotoxic agents such as mycophenolate mofetil (MMF) is controversial, but may be safe in selected patients, although appropriate protocols and long‐term benefits of conversion are not well reported. Methods: We analyzed all liver transplant (LT) recipients at our institution who were converted from CNI‐based therapy to MMF monotherapy because of renal dysfunction (n = 23) and compared them with patients remaining on CNI‐based therapy (n = 23). Renal function, rejection episodes, and markers of CNI‐related comorbidities (lipid profile, blood pressure, and glycosylated hemoglobin) were noted. Results: Overall, serum creatinine (SCr) and calculated glomerular filtration rate improved on MMF monotherapy. This improvement was significant when compared with patients who remained on CNI‐based therapy. Improvement was most pronounced in patients with milder renal dysfunction (SCr <2.2 mg/dL prior to conversion) (n = 14) with decrease in SCr from 1.63 ± 0.29 to 1.34 ± 0.26 mg/dL (p = 0.02) at last follow‐up. Five patients on MMF monotherapy (21.7%) progressed to end‐stage renal disease (ESRD), while only two (8.7%) had rejection episodes following conversion. Clinical markers of CNI‐related comorbidities also improved. MMF monotherapy was well tolerated. Conclusion: In summary, our data support the safety and efficacy of CNI to MMF monotherapy conversion.     

Normative calcaneal quantitative ultrasound data for the indigenous Shuar and non-Shuar Colonos of the Ecuadorian Amazon

Summary

Minimal data on bone mineral density changes are available from populations in developing countries. Using calcaneal quantitative ultrasound (QUS) techniques, the current study contributes to remedying this gap in the literature by establishing a normative data set on the indigenous Shuar and non-Shuar Colonos of the Ecuadorian Amazon.

Purpose

The paucity of bone mineral density (BMD) data from populations in developing countries partially reflects the lack of diagnostic resources in these areas. Portable QUS techniques now enable researchers to collect bone health data in remote field-based settings and to contribute normative data from developing regions. The main objective of this study is to establish normative QUS data for two Ecuadorian Amazonian populations??the indigenous Shuar and non-Shuar Colonos. The effects of ethnic group, sex, age, and body size on QUS parameters are also considered.

Methods

A study cohort consisting of 227 Shuar and 261 Colonos (15?C91?years old) were recruited from several small rural Ecuadorian communities in the Upano River Valley. Calcaneal QUS parameters were collected on the right heel of each participant using a Sahara bone sonometer. Three ultrasound generated parameters were employed: broadband ultrasound attenuation (BUA), speed of sound (SOS), and calculated heel BMD (hBMD).

Results

In both populations and sexes, all QUS values were progressively lower with advancing age. Shuar have significantly higher QUS values than Colonos, with most pronounced differences found between pre-menopausal Shuar and Colono females. Multiple regression analyses show that age is a key predictor of QUS while weight alone is a less consistent determinant. Both Shuar males and females display comparatively greater QUS parameters than other reference populations.

Conclusions

These normative data for three calcaneal QUS parameters will be useful for predicting fracture risk and determining diagnostic QUS criteria of osteoporosis in non-industrialized populations in South America and elsewhere.     

Abduction pillow immobilization following hip surgery: a welcome alternative for selected patients

Background Studies have shown that when using a spica cast following hip surgery in children , there are associated complications such as soiling, pressure sores, and osteopenic fractures. Methods Charts were retrospectively reviewed for all patients who had undergone hip surgeries by one surgeon at one institution between 1999 and 2005. The method of post-operative immobilization (spica cast or abduction pillow) and complications were recorded for each patient. Results There was a total of 32 patients. Of these, 11—all of whom had a diagnosis of developmental dysplasia of the hip—were treated using a spica cast. In the 21 patients treated in an abduction pillow, 4 (19%) were switched to a spica cast for the following reasons: (1) distal femoral fracture as a result of vigorous resuscitation during a choking episode, (2) parental preference, (3) for added immobilization over concern of implant loss of fixation, and (4) concern of migration of the hip, which again migrated after being changed to a spica cast and eventually required a pelvic osteotomy. Conclusion It is our opinion that only one of these complications in the children treated with an abduction pillow (the case of possible implant migration) may have been avoided if the child had originally been placed in a spica cast. The child who was successfully resuscitated after a choking incident weeks after the surgery may have had a worse outcome if it had been in a spica cast. This incident occurred at home and the abduction pillow was easily and quickly removed to allow resuscitation. An abduction pillow is a welcome alternative to a spica cast following hip surgery for many patients with neuromuscular and syndromic conditions. However, in children with osteopenic bone at risk for implant failure and in children with unstable hip reductions, a spica cast may be preferable.