Topography-based screening for previous laser in situ keratomileusis to correct myopia

PURPOSE: To demonstrate the feasibility of developing a screening tool based on corneal topography to detect previous myopic laser in situ keratomileusis (LASIK). SETTING: Clinical data from a private clinic analyzed in a university setting. METHODS: Two hundred thirty-three topographies were randomly selected so 1 topography per patient was used: 150 from unoperated corneas and 83 from corneas that had LASIK to correct myopia. The mean surgical correction was -4.40 diopters (D) +/- 2.53 (SD) (range -11.00 to -0.38 D). All topographies were performed using an Orbscan II unit (Bausch & Lomb Surgical). The LASIK procedures were performed using a Technolas 217C excimer laser and a Hansatome microkeratome (Bausch & Lomb Surgical). The algorithms used the mean value of the directional derivative (DT) of the anterior tangential curvature of the cornea in the 2.2 mm radius central disk and the mean value of the anterior elevation (E) with respect to the best-fit sphere in the 0.5 mm radius central disk. Topographies in the testing set (n = 119) were classified as operated if E < 0 (E algorithm) or DT > 0 (DT algorithm) or as unoperated. RESULTS: The E algorithm yielded 0% false positives and 16.7% false negatives and the DT algorithm, 6.5% and 7.1%, respectively. For myopia greater than -1.12 D, the DT algorithm provided a 0% false negative rate. The performance of E and DT algorithms, used in combination, was superior to clinical assessment. CONCLUSION: Criteria based on Orbscan II corneal topography are proposed for the detection of previous myopic LASIK performed with a Technolas 217C excimer laser.     

Effect of cyclical intravenous pamidronate therapy in children with osteogenesis imperfecta. Open-label study in seven patients

OBJECTIVES: To evaluate the efficacy of pamidronate in protecting against fractures, increasing bone mineral density (BMD), and decreasing bone remodeling marker levels in children with osteogenesis imperFecta. PATIENTS AND METHODS: Seven children (two girls and five boys; mean age, 8.5 years) were given cyclical intravenous pamidronate (Aredia) for 1 to 7 years, with a mean cycle duration of 6 months and a mean dose of 1.86 mg/kg/cycle. Four patients had type III and three type IV disease according to the Sillence classification scheme. RESULTS: A trend toward a decrease in the fracture rate as compared to the pretreatment period was found, but the difference was not significant in this small sample (P = 0.09). Lumbar spine BMD showed a significant annual increase (+26.7%, P = 0.03) far greater than the expected mean annual increase related to growth. No significant decreases in bone remodeling markers were noted. CONCLUSION: Pamidronate seems useful in the treatment of osteogenesis imperfecta in children, since it increases BMD and reduces the fracture rate, in keeping with the findings from the larger series studied by Glorieux. Pamidronate is a symptomatic, noncurative treatment that does not correct the genetic abnormalities responsible for the histological bone alterations.     

Serum lipoproteins in venous blood serum from birth to the end of the first week: feeding influences

Serum lipoproteins were explored on the first day of life (D1) and on the sixth day (D6) in blood drawn by peripheral venipuncture from 43 normal term newborns, 22 breast-fed and 21 formula-fed, and were compared to those of a control group of 28 young adults. With the exception of apolipoprotein E (Apo E), values of lipoprotein components obtained at D1 were similar, although generally slightly lower than those previously reported for cord blood serum. Total Apo E concentration at D1 (71 +/- 25 mg/l) was much higher than that obtained for the adult group (30 +/- 7 mg/l). Apo E distribution within the lipoprotein spectrum confirmed the presence of an already known Apo E-rich high density lipoprotein subfraction, which was responsible for the high total Apo E level at birth. The rise of lipoproteins of low density from D1 to D6, as evidenced by the increase of very low density lipoprotein + low density lipoprotein cholesterol and low density lipoprotein apolipoprotein B concentrations, was shown to be diet dependent. It was significantly less important in newborns fed a standard formula moderately enriched in unsaturated fatty acids than in breast-fed newborns.     

Immunodomination results from functional differences between competing CTL

The presence of dominant epitopes suppresses generation of CTL activity toward other non-dominant epitopes found on the same antigen-presenting cell (APC). This phenomenon, termed immunodomination, drastically restricts the diversity of the repertoire of CTL responses. Under various experimental conditions we assessed the in vivo expansion by tetramer staining and function by expression of O-glycans and intracellular perforin of CTL specific for a dominant (B6(dom1)) and a non-dominant (HY) H2D(b)-restricted epitope. Immunodomination abrogated expansion rather than differentiation of HY-specific CTL. When immunodomination was precluded because HY was presented alone or because high numbers of antigen-bearing APC were present, the numbers of HY-specific T cells detected after antigen priming were similar to those of B6(dom1)-specific T cells. The main difference between T cells that recognized B6(dom1) versus HY was functional rather than quantitative. The key feature of T cells specific for B6(dom1) is that they show striking up-regulation of molecules involved in CTL effector activity rather than accumulating to particularly high levels, as assessed by tetramer staining. These results support the emerging concept that following antigen priming, CTL populations of similar size can display important differences in effector function, and suggest that these functional differences are instrumental in shaping the repertoire of CTL responses.     

Reactions to familiar and novel objects in infant monkeys with neonatal temporal lesions

Adult monkeys with late temporal lobe damage are known to touch and mouth objects compulsively, even unknown objects. To determine whether infants with early temporal damage display this symptom as well, 9-month-old rhesus monkeys with neonatal ablations of either the medial temporal lobe or inferior temporal cortex were exposed to four objects, two familiar and two novel. All operated infants were less active/more withdrawn than controls and showed neither exaggerated object manipulation nor hyperorality. Furthermore, like controls, they touched novel objects less than they touched familiar ones. Thus, infants with neonatal medial or inferior temporal ablations did not display the compulsive exploration evidenced after similar lesions in adulthood and retained some ability to detect novelty despite their known memory impairments.