Cognitive control dysfunction in workers exposed to manganese-containing welding fume.

BACKGROUND: Chronic exposure to manganese (Mn) is a health concern in occupations such as welding because of well-established motor effects due to basal ganglia dysfunction. We hypothesized that cognitive control (the ability to monitor, manipulate, and regulate ongoing cognitive demands) would also be affected by chronic Mn exposure. METHODS: We examined the relationship between Mn exposure and cognitive control performance in 95 workers with varying intensity and duration (median 15.5 years) of exposure to welding fume. We performed linear regression to assess the association between exposure to Mn-containing welding fume and cognitive control tasks. RESULTS: Overall performance was inversely related to intensity of welding exposure (P = 0.009) and was driven by the Two-Back and Letter Number Sequencing tests that assess working memory (both P = 0.02). CONCLUSIONS: Occupational exposure to Mn-containing welding fume may be associated with poorer working memory performance, and workers may benefit from practices that reduce exposure intensity. Am. J. Ind. Med. 60:181-188, 2017. © 2016 Wiley Periodicals, Inc.

Aridity shapes cyanogenesis cline evolution in white clover (Trifolium repens L.).

Adaptive differentiation between populations is often proposed to be the product of multiple interacting selective pressures, although empirical support for this is scarce. In white clover, populations show adaptive differentiation in frequencies of cyanogenesis, the ability to produce hydrogen cyanide after tissue damage. This polymorphism arises through independently segregating polymorphisms for the presence/absence of two required cyanogenic components, cyanogenic glucosides and their hydrolysing enzyme. White clover populations worldwide have evolved a series of recurrent, climate-associated clines, with higher frequencies of cyanogenic plants in warmer locations. These clines have traditionally been hypothesized to reflect a fitness trade-off between chemical defence in herbivore-rich areas (warmer climates) and energetic costs of producing cyanogenic components in areas of low herbivore pressure (cooler climates). Recent observational studies suggest that cyanogenic components may also be beneficial in water-stressed environments. We investigated fitness trade-offs associated with temperature-induced water stress in the cyanogenesis system using manipulative experiments in growth chambers and population surveys across a longitudinal precipitation gradient in the central United States. We find that plants producing cyanogenic glucosides have higher relative fitness in treatments simulating a moderate, persistent drought stress. In water-neutral treatments, there are energetic costs to producing cyanogenic components, but only in treatments with nutrient stress. These fitness trade-offs are consistent with cyanogenesis frequencies in natural populations, where we find clinal variation in the proportion of plants producing cyanogenic glucosides along the precipitation gradient. These results suggest that multiple selective pressures interact to maintain this adaptive polymorphism and that modelling adaptation will require knowledge of environment-specific fitness effects.

Inferior oblique myectomy for postoperative limitation of elevation in abduction.

Antielevation syndrome is commonly described following anteriorization of the inferior oblique muscle. A similar phenomenon may occur following inferior oblique muscle recession, creating a distinct strabismus pattern in the setting of cranial trochlear nerve palsy. We report 3 adult patients, 69-72 years of age, who presented at the Stanford Byers Eye Institute with a similar strabismus pattern-limited elevation in abduction following previous inferior oblique muscle recession for congenital/long-standing trochlear nerve palsy. All 3 patients had a small hypertropia in primary gaze with ipsilateral inferior oblique overaction, limited elevation in abduction, and inferotemporal conjunctival scars. Two patients had a V-pattern strabismus. Following myectomy of the previously recessed inferior oblique muscle, elevation in abduction improved, and symptoms resolved in all 3 patients.

Anterior segment ischemia following strabismus surgery in a young adult using gender-affirming estrogen hormone therapy.

Well-known risk factors for anterior segment ischemia (ASI) following strabismus surgery include ipsilateral surgery on three or more rectus muscles, older age, and vasculopathy. ASI is rarely reported in young patients following uneventful strabismus surgery on two ipsilateral rectus muscles. We report a 30-year-old transgender female on long-term estrogen therapy who underwent strabismus surgery involving recessions of both lateral rectus muscles, the right inferior rectus muscle, and the left superior rectus muscle. The left eye developed severe ASI with hypotony maculopathy that was resistant to topical medications, oral steroids, anterior chamber reformation, and intravitreal steroid injection. Following phacoemulsification with intraocular lens and capsular tension ring insertion 1 year later, intraocular pressure and hypotony maculopathy improved.

Outcomes of inferonasal glaucoma drainage device surgery in the management of childhood glaucoma.

PURPOSE: To evaluate indications and postoperative outcomes of inferonasal Ahmed and Baerveldt glaucoma drainage devices (GDDs) in pediatric glaucoma. METHODS: This retrospective study included patients ≤18 years of age at inferonasal GDD placement, from June 2013 to September 2021. Demographic information, indications, and outcomes were recorded. Successful eyes had intraocular pressure (IOP) ≥5 and ≤21 mm Hg or (in severe cases, where entry IOP was ≤21 mm Hg) 20% below preoperative values without additional IOP-lowering surgery or vision-threatening complications. RESULTS: A total of 68 eyes of 52 patients were included. Mean age was 9.8 ± 5.8 years. Most common diagnoses included primary congenital glaucoma (n = 28 eyes [41%]) and glaucoma following cataract surgery (n = 12 eyes [18%]). Success rates by Kaplan-Meier survival analysis (95% CI) at 1, 2, 3, and 5 years were 62.2% (49.4-72.7), 49.0% (36.3-60.6), 36.8% (24.0-49.8), and 31.9% (18.5-44.5), respectively. Surgical failure was associated with Ahmed (vs Baerveldt) GDD (HR = 3.2; P = 0.002) and inferonasal site as initial (vs subsequent) GDD received (HR = 2.2; P = 0.048). Twenty-five eyes (36.7%) had at least one complication. Although vision-threatening complications were uncommon (n = 2 eyes [3%]), less severe complications were relatively common and included new/worsened strabismus (n = 9 patients [17%]), corneal edema (n = 6 eyes [9%]), lens opacities (n = 4 [6%]), tube or patch graft exposure (n = 3 [4%]), tube blockage (n = 2 eyes [3%]), and other (n = 8 eyes [12%]). CONCLUSIONS: In this study cohort, inferonasal GDDs for childhood glaucoma had modest success, with frequent though rarely vision-threatening complications.

Granulicatella Adiacens as an Unusual Cause of Microbial Keratitis and Endophthalmitis: A Case Series and Literature Review.

PURPOSE: To report two cases of microbial keratitis and/or endophthalmitis involving Granulicatella adiacens. METHODS: Case series. RESULTS: 24-year-old female with a history of Herpes simplex virus 1 (HSV-1) and Candida parapsilosis keratitis presented with a geographic epithelial defect and infiltrate in the left eye. Cultures were positive for HSV-1 and G. adiacens. Keratitis resolved with topical vancomycin and oral valacyclovir. A 65-year-old female with a history of type II diabetes and failed therapeutic penetrating keratoplasty presented with inferior corneal graft haze and vitreous inflammation of the right eye. Therapeutic penetrating keratoplasty and pars plana vitrectomy were performed, and the corneal button returned positive for G. adiacens. The patient was treated with topical and intravitreal vancomycin as well as topical and systemic steroids. CONCLUSIONS: These cases expand the literature on G. adiacens keratitis and endophthalmitis and corroborate the role of steroid use and prior surgery as paramount risk factors.

Visual pathway function and structure in Wolfram syndrome: patient age, variation and progression.

BACKGROUND/AIMS: To report alterations in visual acuity and visual pathway structure over an interval of 1-3 years in a cohort of children, adolescents and young adults who have Wolfram syndrome (WFS) and to describe the range of disease severity evident in patients with WFS whose ages differed by as much as 20 years at first examination. METHODS: Annual, prospective ophthalmological examinations were performed in conjunction with retinal nerve fibre layer (RNFL) analysis. Diffusion tensor MRI-derived fractional anisotropy was used to assess the microstructural integrity of the optic radiations (OR FA). RESULTS: Mean age of the 23 patients with WFS in the study was 13.8 years (range 5-25 years). Mean log minimum angle resolution visual acuity was 0.66 (20/91). RNFL thickness was subnormal in even the youngest patients with WFS. Average RNFL thickness in patients with WFS was 57±8 µ or ~40% thinner than that measured in normal (94±10 µ) children and adolescents (P<0.01). Lower OR FA correlated with worse visual acuity (P=0.006). Subsequent examinations showed declines (P<0.05) in visual acuity, RNFL thickness and OR FA at follow-up intervals of 12-36 months. However, a wide range of disease severity was evident across ages: some of the youngest patients at their first examination had deficits more severe than the oldest patients. CONCLUSION: The genetic mutation of WFS causes damage to both pregeniculate and postgeniculate regions of the visual pathway. The damage is progressive. The decline in visual pathway structure is accompanied by declines of visual function. Disease severity differs widely in individual patients and cannot be predicted from their age.

Selective cognitive and psychiatric manifestations in Wolfram Syndrome.

BACKGROUND: Wolfram Syndrome (WFS) is known to involve diabetes mellitus, diabetes insipidus, optic nerve atrophy, vision loss, hearing impairment, motor abnormalities, and neurodegeneration, but has been less clearly linked to cognitive, sleep, and psychiatric abnormalities. We sought to determine whether these abnormalities are present in children, adolescents, and young adults with WFS compared to age- and gender-matched individuals with and without type 1 diabetes using standardized measures. METHODS: Individuals with genetically-confirmed WFS (n = 19, ages 7-27) were compared to age- and gender- equivalent groups of individuals with type 1 diabetes (T1DM; n = 25), and non-diabetic healthy controls (HC: n = 25). Cognitive performance across multiple domains (verbal intelligence, spatial reasoning, memory, attention, smell identification) was assessed using standardized tests. Standardized self- and parent-report questionnaires on psychiatric symptoms and sleep disturbances were acquired from all groups and an unstructured psychiatric interview was performed within only the WFS group. RESULTS: The three groups were similar demographically (age, gender, ethnicity, parental IQ). WFS and T1DM had similar duration of diabetes but T1DM had higher HbA1C levels than WFS and as expected both groups had higher levels than HC. The WFS group was impaired on smell identification and reported sleep quality, but was not impaired in any other cognitive or self-reported psychiatric domain. In fact, the WFS group performed better than the other two groups on selected memory and attention tasks. However, based upon a clinical evaluation of only WFS patients, we found that psychiatric and behavioral problems were present and consisted primarily of anxiety and hypersomnolence. CONCLUSIONS: This study found that cognitive performance and psychological health were relatively preserved WFS patients, while smell and sleep abnormalities manifested in many of the WFS patients. These findings contradict past case and retrospective reports indicating significant cognitive and psychiatric impairment in WFS. While many of these patients were diagnosed with anxiety and hypersomnolence, self-reported measures of psychiatric symptoms indicated that the symptoms were not of grave concern to the patients. It may be that cognitive and psychiatric issues become more prominent later in life and/or in later stages of the disease, but this requires standardized assessment and larger samples to determine. In the relatively early stages of WFS, smell and sleep-related symptoms may be useful biomarkers of disease and should be monitored longitudinally to determine if they are good markers of progression as well. TRIAL REGISTRATION: Current Clinicaltrials.gov Trial NCT02455414 .

Emotional Eating Phenotype is Associated with Central Dopamine D2 Receptor Binding Independent of Body Mass Index.

PET studies have provided mixed evidence regarding central D2/D3 dopamine receptor binding and its relationship with obesity as measured by body mass index (BMI). Other aspects of obesity may be more tightly coupled to the dopaminergic system. We characterized obesity-associated behaviors and determined if these related to central D2 receptor (D2R) specific binding independent of BMI. Twenty-two obese and 17 normal-weight participants completed eating- and reward-related questionnaires and underwent PET scans using the D2R-selective and nondisplaceable radioligand (N-[(11)C]methyl)benperidol. Questionnaires were grouped by domain (eating related to emotion, eating related to reward, non-eating behavior motivated by reward or sensitivity to punishment). Normalized, summed scores for each domain were compared between obese and normal-weight groups and correlated with striatal and midbrain D2R binding. Compared to normal-weight individuals, the obese group self-reported higher rates of eating related to both emotion and reward (p<0.001), greater sensitivity to punishment (p=0.06), and lower non-food reward behavior (p<0.01). Across normal-weight and obese participants, self-reported emotional eating and non-food reward behavior positively correlated with striatal (p<0.05) and midbrain (p<0.05) D2R binding, respectively. In conclusion, an emotional eating phenotype may reflect altered central D2R function better than other commonly used obesity-related measures such as BMI.

Ophthalmologic correlates of disease severity in children and adolescents with Wolfram syndrome.

PURPOSE: To describe an ophthalmic phenotype in children at relatively early stages of Wolfram syndrome. METHODS: Quantitative ophthalmic testing of visual acuity, color vision, automated visual field sensitivity, optic nerve pallor and cupping, and retinal nerve fiber layer (RNFL) thickness assessed by optical coherence tomography (OCT) was performed in 18 subjects 5-25 years of age. Subjects were also examined for presence or absence of afferent pupillary defects, cataracts, nystagmus, and strabismus. RESULTS: Subnormal visual acuity was detected in 89% of subjects, color vision deficits in 94%, visual field defects in 100%, optic disk pallor in 94%, abnormally large optic nerve cup:disk ratio in 33%, thinned RNFL in 100%, afferent pupillary defects in 61%, cataracts in 22%, nystagmus in 39%, and strabismus in 39% of subjects. RNFL thinning (P < 0.001), afferent pupillary defects (P = 0.01), strabismus (P = 0.04), and nystagmus (P = 0.04) were associated with more severe disease using the Wolfram United Rating Scale. CONCLUSIONS: Children and adolescents with Wolfram syndrome have multiple ophthalmic markers that correlate with overall disease severity. RNFL thickness measured by OCT may be the most reliable early marker.