Aircrew decision-making behavior in hazardous weather avoidance

In-flight encounters with hazardous weather represent one of the most significant safety issues in civil aviation operations. Aircrew judgment is often cited as the probable cause of incidents and accidents involving weather, although lack of information is also a factor. The present study examines how information, presented at different times and in different forms, affects the awareness and decision-making behavior of aircrews in a flight simulation study of a recent microburst/windshear incident. In order to examine the influence of enhanced information transfer on aircrew behavior, intracrew communications and approach-to-land decisions were evaluated with conventional ATC communications and with automated cockpit alerting and display of weather information. Results of the study revealed that aircrews provided only with conventional ATC transmissions of weather information had difficulty discriminating conditions conducive to microburst events from less hazardous windshear events. Improved situation awareness for microburst events was found when ground-based convective weather information was provided in real time to aircrews. Avoidance decision-making was found to be less efficient with conventional ATC alert transmissions when compared to the performance of crews provided with a visual display of microburst events. The importance of information transfer on aircrew situation awareness and decision-making in hazardous weather avoidance is discussed.     

Evaluation of the legal risk of a ‘missed’ cancer in two breastscreen services

Variation in opinions of medical experts is a problem for both the legal and medical profession. This is particularly relevant in breast imaging. BreastScreen Queensland and New South Wales have developed a review protocol to assess ‘reasonableness’ of radiological opinions. It is hoped that the protocol will be acceptable to the courts and will result in a fair outcome for all parties involved in a medico-legal dispute.     

A dermal equivalent developed from fibroblast culture alone: Effect of EGF and insulin

We have recently developed a new dermal equivalent without exogenous materials by culturing dermal fibroblasts alone in serum-containing medium treated with several supplements. In this study, we investigated the effects of epidermal growth factor (EGF) and insulin on the formation of a dermal equivalent. After cultured dermal fibroblasts reached a confluence in serum-containing medium, they were treated with EGF or insulin. The combined effects of EGF and insulin were also studied. Macroscopically, in contrast to the culture without supplement, the addition of EGF or insulin produced a fibrous sheet. The combination of EGF and insulin showed a more marked effect than a single factor. Histologically, EGF or insulin alone induced a three-dimensional tissue containing several layers of fibroblasts. The combination of EGF and insulin produced a thicker tissue. It was composed of abundant extracellular matrix containing fibroblasts, suggesting a dermis-like tissue. It revealed collagen fibers by Masson-trichrome staining. Immunohistochemically, the components of dermal extracellular matrix such as type 1 collagen, elastin, and fibrillin-1 were diffusely expressed. Ultrastructurally, a large number of collagen fibrils with cross-striated patterns were found around the fibroblasts. These results showed that a dermal equivalent could be formed by culturing dermal fibroblasts alone postconfluently in serum-containing medium with EGF and insulin. They suggest that the two factors play an important role in the formation of a dermal equivalent.     

Peritoneal dialysis patient survival: a comparison between a Swedish and a Korean centre.

BACKGROUND: Dialysis patient mortality remains high, and this high mortality may be due to many factors. In peritoneal dialysis (PD) patients, old age, co-morbid diseases, malnutrition, low residual renal function (RRF) and a high peritoneal transport rate have been shown to influence survival, but the relative importance of these factors may differ between different patient populations. Besides, centre practice patterns may differ between centres and may influence patient survival. In addition, the literature suggests that dialysis patient survival may be better in Asian than in Caucasian patients. METHODS: The influence of centre and patient characteristics on patient survival was investigated in 132 Korean and 106 Swedish incident PD patients, who underwent initial biochemical measurements and assessment of adequacy of dialysis, nutritional status, RRF and peritoneal transport characteristics. RESULTS: At the start of PD, Korean patients had a higher prevalence of diabetes, peritoneal Kt/V(urea), peritoneal creatinine clearance and peritoneal fluid removal, and lower body mass index, RRF and dialysate to plasma creatinine concentration ratio (D/P Cr) compared with Swedish patients. Significantly more patients from Korea were placed on temporary haemodialysis before PD (100 out of 132) when compared with Swedish patients (21 out of 106). During the follow-up, there was a significantly higher rate of transfer to other units in Korea and a significantly higher rate of kidney transplantation in Sweden. On Kaplan-Meier analysis, overall patient survival did not differ and relative risk for death was also not different between the two centres even after adjustment for age, diabetes, cardiovascular disease, RRF and D/P Cr. On Cox proportional hazards multivariate analysis, age, diabetes, RRF and D/P Cr were found to be independent predictors of mortality in the combined cohort of patients. While age, diabetes and D/P Cr were independent predictors of mortality in Korean patients, age and RRF independently predicted mortality in Swedish patients. CONCLUSION: Although there were significant differences in centre and patient characteristics, we were unable to confirm a survival advantage for Korean over Swedish PD patients. The results of this study suggest that the reported difference in survival between Asian and Caucasian dialysis patients may have been due, in part, to differences in centre and patient characteristics rather than to race as such. The genetic influence on patient characteristics remains, however, to be elucidated.     

Intravitreal triamcinolone injection for macular edema secondary to increased retinal vascular permeability.

BACKGROUND AND PURPOSE: Macular edema is an important cause of visual loss in various retinal diseases, and may be refractory to conventional treatment. We investigated the efficacy of intravitreal injection of triamcinolone acetonide for the treatment of intractable macular edema. METHODS: A prospective study was conducted in 17 patients (18 eyes) with a diagnosis of macular edema unresponsive to conventional treatment, resulting from inflammatory or retinal vascular diseases. The underlying diseases associated with the development of macular edema were: diabetic retinopathy (6 eyes), branch retinal vein occlusion (5 eyes), Irvine-Gass syndrome (3 eyes), and central retinal vein occlusion (4 eyes). Triamcinolone acetonide 4 mg was injected intravitreally. Ophthalmological examinations, fundus photography, fluorescein angiography, and optical coherence tomography were performed before treatment, 3 months and 6 months after treatment. During the follow-up period, recurrent macular edema was retreated with the same dosage and followed for another 6 months. RESULTS: Sixteen eyes received a single injection and 2 others (11%) underwent reinjection after the 3-month follow-up examination. Among the eyes that received a single injection, 10 (63%) showed visual acuity gain of 2 or more Snellen lines at the 6-month follow-up. The pretreatment central macular thickness averaged 581 microm [corrected] and reduced to 215 microm [corrected] at the 6-month follow-up. In the 2 eyes that received reinjection, macular edema also showed significant reduction 6 months after retreatment. Sterile endophthalmitis was noted in 3 eyes (17%). Two eyes (11%) developed significant cataract. Three eyes (17%) developed high intraocular pressure; 1 of them (5.5%) ultimately required filtering surgery. CONCLUSIONS: Intravitreal injection of triamcinolone temporarily reduced refractory macular edema. Potential complications should be monitored after treatment.     

Management of filamentary keratitis associated with aqueous-deficient dry eye.

PURPOSE: To review the incidence, underlying pathophysiology, and clinical features of filamentary keratitis and to identify evidence-based best-practice strategies for managing filamentary keratitis. METHODS: A comprehensive review of published literature was undertaken. Recommendations for best-practice management strategies were based on the available evidence. Three cases are presented to illustrate the clinical findings and management of patients with chronic filamentary keratitis. RESULTS: Although the evidence base is limited by the absence of well-designed studies, current evidence indicates the following: (1) Aqueous-deficient dry eye (keratoconjunctivitis sicca) is the most common ocular condition associated with filamentary keratitis. (2) Current best-practice management of filamentary keratitis involves treating the underlying dry eye and specific treatments for the corneal filaments. Proposed treatments include nonpreserved lubricants, topical steroidal and nonsteroidal anti-inflammatory agents, and punctal plugs for aqueous-deficient dry eye as well as mechanical removal of filaments, hypertonic saline, mucolytic agents, and bandage contact lenses for the filaments. (3) Filamentary keratitis can be induced or exacerbated by contact lens wear and ocular surgical procedures such as cataract surgery and corneal graft surgery. Pre- and postoperative ocular surface management strategies should be considered in the surgical planning of patients with, or who are susceptible to, filamentary keratitis. Filamentary keratitis can also be induced and/or exacerbated by chronic use of ocular and/or systemic medications, and alternate medications or additional measures to manage the tear film and ocular surface may be required in these cases. CONCLUSIONS: Filamentary keratitis can be a chronic, recurrent, and debilitating condition. With a systemic approach to diagnosis and management, the condition can be effectively controlled and the incidence and severity of recurrences minimized.