The Fate of Global Precedence With Age

The literature is virtually devoid of studies examining the effect of aging on the ''global precedence'' effect (Navon, D. [1977]. Cognitive Psychology, 9, 353-383). In this paradigm, global letters formed with local letters are shown, and the subject has to recognize either the local or the global letters. The relation between the global and the local letters is either congruent, neutral, or conflicting. Five experiments are reported, with five sets of 16 young and five sets of 16 elderly, healthy, adult subjects. The global precedence effect was observed in both age groups in the basic perceptual experiment as designed by Navon (Experiment 1). In addition, young and elderly subjects were able to process separately the global and the local shapes when attention was not directed towards a specific level (Experiment 1a). However, subpopulations emerged, especially in the elderly, depending on their ability to ''resist'' to the interference of the global shape upon the processing of the local form. This could support the few indirect published data suggesting that global precedence tends to diminish or to disappear with age. In experiments 2 and 2a, subjects were retained only if they did process the local level better than at random. Global precedence was confirmed in both young and elderly subjects. Again, elderly subjects manifested an increased sensitivity to interference. Moreover, a general effect of age remained, even in the control (neutral) conditions, suggesting difficulties of encoding in elderly. Therefore, in Experiment 3, encoding conditions of both age groups were equated by increasing exposure durationof the material for elderly. Subjects of Experiment 3 were also submitted to a Strooptest, to verify whether the increased sensitivity to interference in the elderly was specific to the ''Navon task'' or the expression of a general effect of aging on inhibition mechanisms. The global precedence phenomen on was observed in young andelderly subjects, with no sign of an effect of age under these conditions; in elderly, furthermore, the interference effect did not appear to result froma general aspecific deficit of inhibition mechanisms. It thus appears that the global precedence phenomenon resists well the effects of aging, but that subpopulations of elderly subjects should be considered in future studies.     

In Vivo Evaluation of a Retrievable Vena Cava Filter—The Dibie-Musset Filter: Experimental Results

Purpose: To evaluate, in an animal model, the efficacy and safety of a 7 Fr percutaneous vena cava filter for temporary or permanent use. Methods: The Dibie-Musset (DM) filter is a wire preformed into a double-spiral shape with a spring effect. The experiment was performed in 15 adult sheep and consisted of the insertion of 45 filters, clot trapping tests, and filter retrieval. Follow-up in all sheep consisted of radiologic (abdominal radiograph, inferior vena cavogram, abdominal computed tomography), macroscopic, and microscopic examinations between days 8 and 386 after filter placement. Results: Of the 45 filters implanted in 15 sheep, 29 were retrieved between day 0 and day 15. Filtration efficiency was 100% for clots 4 × 4 × 20 mm. No long-term (1 year) side-effects were detectable. Microscopic examination of the vein wall showed only a dense intimal fibrosis without signs of acute inflammation at 1 year. Conclusion: These results support the efficiency and safety of the DM filter in an animal model.     

Chondroid cystic malformation of the lung with trisomy 8 mosaicism: a new cystic lung malformation

Neonatal cystic disorders of the lungs are a heterogeneous malformative group including giant lobar hyperinflation, congenital pulmonary airway malformations, intralobar pulmonary sequestration, and bronchogenic cyst. Here, we describe a giant cystic pulmonary malformation in a 5-year-old girl, morphologically characterized by a highly disorganized proliferation of numerous cartilage islands, abundant mesenchymal tissue with abundant adipose differentiation, and epithelium-lined cysts. Cytogenetic analysis revealed an isolated trisomy 8, as the sole karyotype anomaly, a finding further confirmed by a whole-genome single nucleotide polymorphism array genotyping. The trisomy 8 was observed by fluorescent in situ hybridization within the malformation, and also in adjacent pulmonary parenchyma. A search of the literature revealed only 2 cases having similarities with the present case, but bearing different names. We believe that this lesion differs from congenital pulmonary airway malformations and from adult-type pulmonary hamartomas. We propose for this malformative mass the name "chondroid cystic malformation of the lung."     

Amniotic fluid beta-endorphin: a prognostic marker for gastroschisis?

Purpose: The aim of this work was to study amniotic fluid [beta ]-endorphin as a potential predictor for postnatal morbidity in gastroschisis. Methods: Beta-endorphin was assayed in 43 amniotic fluid samples from 13 pregnant women with fetal gastroschisis undergoing diagnostic amniocentesis or therapeutic amnioinfusion and compared with 33 controls. Within the gastroschisis group, the authors investigated the relationship between postnatal morbidity and the peak value of amniotic fluid [beta ]-endorphin (AFBE). Results: Ten AFBE values in 6 cases of gastroschisis were above the upper limit of the 95% confidence interval derived from controls. Postnatal morbidity was significantly higher when peak AFBE exceeded 10 [mu ]g/L (n = 4 pregnancies) compared with below 5 [mu ]g/L (n = 9 pregnancies), as shown by mean duration of mechanical ventilation (15.2 v 3 days; P = .01), of parenteral feeding (77 v. 18.7 days; P = .04), and of hospitalization (84 v 32.2 days; P = .04). There was no statistically significant association between postnatal morbidity markers and prenatal dilation of fetal bowel. Conclusions: The most severe cases of gastroschisis are associated with high levels of AFBE. The authors speculate that this fetal hormonal response could result from stress or pain caused by prenatal bowel damage.     

Evaluation of Tissue-Engineered Skin (Human Skin Substitute) and Secondary Intention Healing in the Treatment of Full Thickness Wounds after Mohs Micrographic or Excisional Surgery

BACKGROUND: Human Skin Substitute (Apligraf, Organogenesis, Inc., Canton, MA) is a bi-layered tissue-engineered living biological dressing developed from neonatal foreskin. It consists of a bovine collagen matrix containing human fibroblasts with an overlying sheet of stratified human epithelium containing living human keratinocytes. Human Skin Substitute (HSS) appears to be immunologically inert, and has shown usefulness in the treatment of chronic and acute wounds. OBJECTIVE: Primary objectives were to evaluate the safety and efficacy of HSS in the treatment of full-thickness wounds in a prospective case series. Secondary objectives were to determine the rate of complete wound reepithelialization, incidence of complete wound healing, pain at wound site, overall cosmetic outcome, and patient satisfaction. METHODS: Fourteen patients were enrolled in the study, of which 12 were evaluable. HSS was applied in a blinded fashion to 6 of the patients immediately following Mohs or excisional surgery for skin cancer. The remaining 6 patients were allowed to heal by secondary intention. Both groups were evaluated at weekly appointments until complete reepithelialization occurred. During each evaluation, wound quality was assessed through the Vancouver Burn Scar Assessment Scale by the investigator and an independent blinded dermatologist. The investigator, blinded observer, and patient further evaluated the cosmetic outcome of the wound through the use of a Visual Analog Scale over a 6-month period. RESULTS: HSS patients and secondary intention patients were equivalent in comorbid factors such as pain, erythema, edema, exudate, infection, or hematoma between the groups. The incidence of complete wound healing at 6 months was 100% for both groups. Both groups also appeared to heal at similar rates, as defined by the complete reepithelialization of the wound. HSS patients ultimately resulted in more pliable and less vascular wounds as defined by the Vancouver Burn Scar Assessment Scale. Patient satisfaction with cosmetic outcome in both groups was positive at 6 months. CONCLUSIONS: HSS appears to be a safe, well-tolerated biological dressing with equivalent comorbid factors to secondary intention healing. HSS, however, seems to produce a more pliable and less vascular scar than those developed through healing by secondary intention. HSS also appears to produce more satisfactory cosmetic results when compared to secondary intention healing.     

Chronic active gastritis in X-linked lymphoproliferative disease

Gastric lesions in primary constitutive immune deficiencies include multifocal atrophic gastritis, erosive pangastritis, and a pattern of gastric lesions reminiscent of graft-versus-host disease. We describe the genetic anomalies in 2 monozygotic twins with an X-linked lymphoproliferative disease (XLP; MIM 308240), a rare familial setting of high susceptibility to Epstein-Barr virus (EBV). Since early childhood, both twin brothers exhibited a severe chronic active atrophic pangastritis. A germline screening of the SH2D1A (MIM 300490) and BIRC4 (MIM 300079) genes was performed, and also a high-resolution whole-genome SNP profiling (Infinium Sentrix Human-1 Genotyping BeadChip, Illumina). A 3 Megabase deletion in the Xq25 region, encompassing the SH2D1A gene, was defined by SNP array genotyping. Histologic analysis of yearly or twice yearly gastric biopsies in both children showed a Helicobacter pylori-negative, Epstein-Barr virus-negative chronic active atrophic pangastritis, with superficial ulcer formation, foveolar hyperplasia, glandular dilatation and ultimately pseudopyloric and intestinal metaplasia. No such chronic active inflammatory gastric lesions have been reported to date in XLP. The similarities between XLP and common variable immunodeficiency (MIM 240500) underscore the need for early recognition and close monitoring of these gastric lesions, with special regard to their neoplastic potential. No infectious cause was determined. We favor a dysimmune mechanism in the development of this chronic atrophic gastritis, presenting a striking similarity to the recently described atrophic autoimmune pangastritis.     

Effect of build orientation on the manufacturing process and the properties of stereolithographic dental ceramics for crown frameworks

Statement of problemStereolithography (SLA) ceramic crown frameworks are suitable for clinical use, but the impact of SLA build orientation has not been identified.PurposeThe purpose of this in vitro study was to investigate the effect of 3 build orientations on the physical and mechanical properties and the microstructure of SLA alumina dental ceramics.Material and methodsThe physical and mechanical properties and microstructures of 3 different oriented SLA alumina ceramics (ZX, ZY, and XY) were evaluated by visual observation, hydrostatic weighing (n=10/group), Weibull analyses (n=30/group), scanning electron microscopy, 3-point flexural strength (n=30/group), fracture toughness (indentation, single-edge-V-notched-beam) (n=4/group), and Vickers hardness (n=15/group) testing. The hydrostatic weighing, 3-point flexural strength, fracture toughness, and Vickers hardness testing data were statistically analyzed (α=.05).ResultsThe minimum resting period of slurries between the polymerization of 2 layers was shorter for the ZY- and ZX-oriented specimens and increased with the layer surface. The density and Vickers hardness of the SLA-manufactured specimens were similar for all groups (P>.05). The 95% confidence intervals of the Weibull moduli of the ZX- and ZY-oriented specimens were higher than that of the XY-oriented specimens, with no overlap fraction. The ZY-oriented specimens displayed significantly higher 3-point flexural strength (P<.05) and fracture toughness as evaluated by the single-edge-V-notched-beam method than the ZX-oriented specimens (P<.05). They also displayed significantly higher 3-point flexural strength than the XY-oriented specimens (P<.05). The microstructural analysis showed that the texturing was heterogeneous and that the major axis of the large grains of alumina ran parallel to the orientation of the layers.ConclusionsThe ZY orientation produced a reliable dental ceramic by SLA, with the shortest general manufacturing time and the highest mechanical strength when the layers were perpendicular to the test load surface.