New test to assess pilot's vision following refractive surgery

BACKGROUND: All forms of corneal refractive surgery can sometimes cause an increase in optical aberrations and scattered light, which can affect visual performance. The purpose of this study was to develop a suitable test that was sensitive to retinal image degradation in subjects who have undergone excimer laser refractive surgery and that was also relevant to visual demands in commercial aviation. METHODS: Assessment of the visual environment and the tasks involved in piloting a commercial aircraft formed the basis for the selection of the test parameters. The new contrast acuity assessment (CAA) test covers a functional visual field of +/-5 degrees and is based on minimum spatial vision requirements for commercial pilots. RESULTS: Data measured in 100 normal subjects were used to define the 'standard normal observer' and the range of variation for the parameters of the test. This approach makes it possible to quickly establish whether a given subject's performance falls within the range of the standard normal observer. The test is also administered under low ambient illumination since flying at night involves mesopic levels of light adaptation when the pupil size is large and the effects of aberrations and scattered light are therefore more pronounced. CONCLUSION: The results of the test are simple to interpret and reveal visual performance that falls outside the normal range as a result of either significant degradation of retinal image quality (caused by increased aberrations and scattered light) or abnormal processing of visual information in the retina and/or the visual pathway.     

Successful pregnancy in a woman with Bloom syndrome

Bloom syndrome is a rare autosomal recessive disorder notable for increased chromosome fragility and an increased rate of somatic mutation. The clinical manifestations include small stature, a characteristic dermatologic lesion, and an excess incidence of malignancy. Fertility is generally reduced. A 19-year-old white woman with Bloom syndrome was successfully treated for preterm labor at 32 weeks' gestation, and ultimately delivered a healthy male infant at 35 weeks' gestation. Reports of pregnancy in women with Bloom syndrome are few. Despite reduced fertility, conception can occur, and women with Bloom syndrome should receive appropriate reproductive counseling to prevent unintended pregnancies and increased surveillance for preterm birth.     

Position dependent ventricular tachycardia in two children with peripherally inserted central catheters (PICCs)

We report two cases of ventricular tachycardia (VT) in children following the insertion of peripherally inserted central catheters (PICCs). These children had additional procedures requiring turning into the left lateral position after PICC insertion. In both cases sustained VT occurred after turning and flexion of the arm with the PICC. VT was terminated in both cases by withdrawing the catheter.     

Thrombin-activatable fibrinolysis inhibitor (TAFI): a novel predictor of angiographic coronary restenosis

The fibrinolytic system is closely related to several processes that are involved in restenosis. We previously showed that low PAI-1 plasma levels predicted restenosis. Recently, a different fibrinolytic inhibitor, TAFI, has been described. The aims of this study were to evaluate the relationship between pre-procedural plasma levels of TAFI and late angiographic restenosis and the interaction between TAFI and PAI-1.We prospectively studied 159 patients with stable angina who underwent successful elective angioplasty or stenting of de novo native coronary artery lesions. TAFI and PAI-1 antigen levels were measured in plasma samples drawn before the procedure. Follow-up coronary angiography was performed in 92% of patients. There was a significant correlation between pre-procedural TAFI levels and 6-month % diameter stenosis (DS) (r = 0.21; p = 0.013). The overall angiographic restenosis rate (DS>50%) was 31%. Pre-procedural TAFI levels were significantly higher in patients with restenosis (108 +/- 33% versus 94+/-30%, p = 0.011). Restenosis rates for patients in the upper tertile of TAFI levels were 2-fold higher than for those in the lowest tertile (45% versus 22%; p = 0.016). A combination of high TAFI and low PAI-1 levels identified patients at the highest risk of restenosis (53%) compared to 14% in patients with low TAFI and high PAI-1 levels; p = 0.027. In conclusion, pre-procedural plasma TAFI antigen levels identify patients at increased risk for restenosis after PCI.     

Independent influences of central fat and skeletal muscle lipids on insulin sensitivity

OBJECTIVE: Insulin resistance is closely associated with two disparate aspects of lipid storage: the intracellular lipid content of skeletal muscle and the magnitude of central adipose beds. Our aim was to determine their relative contribution to impaired insulin action. RESEARCH METHODS AND PROCEDURES: Eighteen older (56 to 75 years of age) men were studied before elective knee surgery. Insulin sensitivity (M/Delta I) was determined by hyperinsulinemic-euglycemic clamp. Central abdominal fat (CF) was assessed by DXA. Skeletal muscle was excised at surgery and assayed for content of metabolically active long-chain acyl-CoA esters (LCAC). RESULTS: Significant inverse relationships were observed between LCAC and M/Delta I (R(2) = 0.34, p = 0.01) and between CF and M/Delta I (R(2) = 0.38, p = 0.006), but not between CF and LCAC (R(2) = 0.0005, p = 0.93). In a multiple regression model (R(2) = 0.71, p < 0.0001), both CF (p = 0.0006) and LCAC (p = 0.0009) were independent statistical predictors of M/Delta I. Leptin levels correlated inversely with M/Delta I (R(2) = 0.60, p = 0.0002) and positively with central (R(2) = 0.41, p = 0.006) and total body fat (R(2) = 0.63, p = 0.0001). DISCUSSION: The mechanisms by which altered lipid metabolism in skeletal muscle influences insulin action may not be related directly to those linking central fat and insulin sensitivity. In particular, it is unlikely that muscle accumulation of lipids directly derived from labile central fat depots is a principal contributor to peripheral insulin resistance. Instead, our results imply that circulating factors, other than nonesterified fatty acids or triglyceride, mediate between central fat depots and skeletal muscle tissue. Leptin was not exclusively associated with central fat, but other factors, secreted specifically from central fat cells, could modulate muscle insulin sensitivity.     

Unintentional traumatic brain injury in children: the lived experience

Brain injury is a major cause of injury death and long-term neurological impairment in children often requiring long-term support. Despite the significance and frequency of such injuries, very little is known about the circumstances of these injuries, the long-term outcomes and family support needs. In this pilot study of 10 families of children with traumatic brain injury, participants described a variety of factors which contributed to their child's injury (inattentiveness, unfamiliarity, developmental level, lack of protective gear, invulnerability, peer pressure, environmental hazards and lack of supervision). As a result of their child's injury, family members described fundamental shifts in how they view life and that the roles and responsibilities of family members changed drastically. Study families experienced sustained uncertainty and described the impact on family relationships. While social support was clearly a mediating factor, families described the need for ongoing support and services to help them adapt to new roles, cope with new challenges, and manage sequellae such as post-traumatic headaches, epilepsy, learning difficulties and behavioural problems. The study findings represent an initial attempt to develop knowledge upon which focussed injury prevention interventions can be developed. Furthermore, this information will assist in the determination of appropriate health, rehabilitative, and educational support services for children with brain injuries. Involving families in this way will enhance the implementation of practical and useful support services for families of children with brain injuries.     

Comparison of a vitamin E-rich diet and supplemental vitamin E on measures of vitamin E status and lipoprotein profile

OBJECTIVE: To determine whether dietary modification rather than use of supplements can raise indices of vitamin E status to potentially cardioprotective levels. DESIGN: Eight week randomised controlled trial with parallel treatments to compare increased use of vitamin E-rich foods, supplementation with 200 IU of vitamin E, and a placebo. SETTING: Dunedin, New Zealand. SUBJECTS: Ninety subjects were recruited, of whom 82 non-smoking, free-living individuals aged 22-72 y with plasma cholesterol <7.5 mmol/l completed the trial. MAIN OUTCOME MEASURES: Dietary intakes, plasma alpha tocopherol, plasma alpha tocopherol/cholesterol ratio and lipoprotein cholesterol. RESULTS: Consumption of an additional 12 mg of vitamin E (alpha tocopherol equivalents) from dietary sources was primarily achieved through the replacement of saturated fat-rich foods with unsaturated fats rich in vitamin E, nuts and vegetables. This resulted in a 3.4 micromol/l increase in plasma alpha tocopherol at week 6 (95% CI 1.6-5.3), and 0.9 micromol/mmol in plasma alpha tocopherol/cholesterol at weeks 4 and 6 (95% CI 0.3-1.4 and 0.4-1.4, respectively) when compared with the placebo group. In the supplement group, plasma alpha tocopherol and plasma alpha tocopherol/cholesterol were significantly increased within 2 weeks and remained so throughout the 8 week intervention. CONCLUSION: Increasing dietary vitamin E intake can increase plasma alpha tocopherol levels, although factors other than dietary intake are also important determinants. The extent of dietary modification required to achieve potentially cardioprotective levels of plasma alpha tocopherol is difficult in practice. SPONSORSHIP: The study was supported through the Otago Medical Research Foundation Laurenson Award.