Performance comparison of the Alcon Legacy 20000 straight and flared 0.9 mm Aspiration Bypass System tips

PURPOSE: To compare the efficiency of surgical procedures using 2 phacoemulsification tips. SETTING: Wolfe Clinic, Marshalltown, Iowa, USA. METHODS: A randomized prospective study of 256 consecutive cases was conducted. The patients were adults having phacoemulsification by a modified in situ fracture technique. All cases were done by 1 surgeon using the Alcon Legacy 20000 phacoemulsification machine with high-vacuum cassettes and tubing. One of 2 45-degree Aspiration Bypass System (ABS) phacoemulsification tips was used. The straight tip has a 0.9 mm outside diameter (n = 127). The flared tip has a 0.76 mm outside diameter shaft that flares to a 1.02 mm tip (n = 129). Measurements at the time of surgery included metered phacoemulsification time, percentage power used, total phacoemulsification time, and milliliters of balanced salt solution (BSS(R)) used. RESULTS: No posterior capsule tear, vitreous loss, incision thermal damage, incision leak, or suture closure occurred. There were no cases of iris aspiration into the working end of the phacoemulsification needle; however, the iris was aspirated into the ABS opening of the flared tip in 1 case. Similar measurements for the straight and flared tips included, respectively, metered phacoemulsification time, 1.4 minutes each; mean power percentage, 41% and 39%; total phacoemulsification time, 2 minutes 11 seconds and 2 minutes 15 seconds; and overall BSS volume, 77 mL and 75 mL. The anterior capsule tear rates for straight (5.5%) and flared (1.6%) tips were similar. CONCLUSIONS: The flared ABS phaco tip with a 0.76 mm shaft outside diameter provided the physical advantages of shaft diameter reduction and required ultrasonic energy expenditures, BSS volumes, and surgical times similar to those of the straight ABS ultrasonic tip with a 0.9 mm outside diameter.     

Youth at risk of physical inactivity may benefit more from activity-related support than youth not at risk

Background  

This study examines whether associations between activity-related support and adolescents' physical activity differ for adolescents at high versus low risk of physical inactivity.     

Peak power predicts performance power during an outdoor 16.1-km cycling time trial

PURPOSE: To assess i) the reproducibility of peak power output recorded during a maximal aerobic power test (MAP), and ii) its validity to predict endurance performance during a field based 16.1-km time trial (16.1-km TT). METHODS: Two studies were completed: for part I, nine subjects performed three MAP tests; for part II, 16 subjects completed a MAP test and 16.1-km TT. Power output was recorded using an SRM power meter and was calculated as peak power output (PPO) recorded during 60 s of MAP and mean power output for the 16.1-km TT (16.1-km TT(PO)). RESULTS: There was no difference between PPO recorded during the three MAP trials, mean coefficient of variation for individual cyclists was 1.32% (95%CI = 0.97-2.03), and test-retest reliability expressed as an intraclass correlation coefficient was 0.99 (95%CI = 0.96-1.00). A highly significant relationship was found between PPO and 16.1-km TT(PO) (r = 0.99, P < 0.001) but not for PPO and 16.1-km TT time (r = 0.46. P > 0.05). CONCLUSION: The results show that PPO affords a valid and reliable measure of endurance performance which can be used to predict average power during a 16.1-km TT but not performance time.     

The validity of power output recorded during exercise performance tests using a Kingcycle air-braked cycle ergometer when compared with an SRM powermeter

This study assessed the validity of power output recorded using an air-braked cycle ergometer (Kingcycle) when compared with a power measuring crankset (SRM). For part one of the study thirteen physically active subjects completed a continuous incremental exercise test (OBLA), for part two of the study twelve trained cyclists completed two tests; a maximal aerobic power test (MAP) and a 16.1 km time-trial (16.1 km TT). The following were compared; the peak power output (PPO) recorded for 1 min during MAP, the average power output for the duration of the time-trial and power output recorded during each stage of OBLA. For all tests, power output recorded using Kingcycle was significantly higher than SRM (P < 0.001). Ratio limits of agreement between SRM and Kingcycle for OBLA showed a bias (P < 0.00) of 0.90 (95%CI = 0.90-0.91) with a random error of X or / 1.07, and for PPO and 16.1 km TT ratio limits of agreement were 0.90 (95%CI = 0.88-0.92) X or / 1.07 and 0.92 (95% CI = 0.90-0.94) X or / 1.07, respectively. These data revealed that the Kingcycle ergometry system did not provide a valid measure of power output when compared with SRM.     

Unilateral haemorrhagic parenchymal lesions in the preterm infant: shape, site and prognosis

Rademaker KJ, Groenendaal F, Jansen GH, Eken P, de Vries LS. Unilateral haemorrhagic parenchymal lesions in the preterm infant: shape, site and prognosis. Acta Pædiatr 1994;83:602–8. Stockholm. ISSN 0803–5253 In a prospective cranial ultrasound study of 544 infants with a gestational age of 32 weeks or less, 20 (3.6%) infants were diagnosed as having a unilateral parenchymal lesion (PL). Based on the shape of the PL and the evolution on ultrasound, the infants were divided into three groups: group I consisted of 11 infants, in whom the PL was triangular/fan-shaped and separate from the ventricle. The PL evolved into small cystic lesions; group II comprised 3 infants who had a PL with a similar shape, but partially communicating with the ventricle; group III consisted of 6 infants who had a globular-shaped lesion in communication with the ventricle. In groups II and III, the PL evolved into one porcncephalic cyst. The PL was considered to be due to venous infarction in all cases with intraventricular haemorrhage preceding the PL in 7 cases. Sixteen infants survived. A postmortem was performed in 2 of the 4 infants who died, confirming the diagnosis of venous infarction. Neurologicdl sequelae were present in only 2 cases in the first group, while all 6 survivors of the other two groups developed mild to severe hemiplegia. Long-term follow-up was not always available and 4 of the 18 survivors were still less than 18 months when last seen. In 9 of the 11 infants in group I, the PL was localized in the frontoparietal region, while in 8 of the 9 infants in group II or III, the PL was beyond the trigone in the occipital region. The outcome of the unilateral PL is not always unfavourable. It was evident that not only the shape of the lesion and whether or not there was communication with the lateral ventricle, but also the site of the lesion (whether or not it extended into the occipital periventricular white matter) appeared to be important with regard to neurodevelopmental outcome.     

Ultrasonic features of pyogenic liver abscesses

Ultrasonic features of 21 surgically confirmed pyogenic liver abscesses in 18 patients were analyzed. Typical lesions were round or ovoid with a discrete, irregular, echo-poor margin. The number and intensity of internal echoes and sound transmission were variable. Such lesions can be aspirated percutaneously for definitive preoperative diagnosis. Pyogenic liver abscesses appear to have more ragged walls and are less frequently elliptical or multilocular than abscesses elsewhere in the abdomen.