Significance of epidermoid formations in the middle ear in fetuses and children

OBJECTIVE: To determine the incidence, size, and location of epidermoid formations (EFs), which have been suggested to be precursors of congenital cholesteatomas, in temporal bones from fetuses and children. DESIGN: We examined temporal bones from 226 fetuses and children up to the age of 10 years for the incidence, size, and location of EFs. RESULTS: Twenty-five EFs were identified in middle ears of 3 fetuses, 7 neonates, 9 infants, and 2 children aged 2 and 3 years. There was a male-female preponderance of 5:4. Generally, we saw EFs between the anterosuperior edge of the eardrum and the anterior limb of the tympanic ring, but 4 were below the level of the handle of the malleus. Their widths ranged from 25 to 300 microns. Keratinization was not observed in any EF. Contrary to previous reports, we found EFs not only in ears of fetuses, but also in ears of infants and children. CONCLUSION: Although EFs may persist in some ears, possibly developing into congenital cholesteatomas, our findings do not provide direct support for this concept.     

Laundering shrinkage of wool fabric treated with low-temperature plasmas under atmospheric pressure

Wool fabrics have been treated with helium/argon and acetone/argon low-temperature plasmas under atmospheric pressure. The plasma-treated fabrics were laundered several times and their shrink resistances investigated according to standard methods. Very high levels of shrink resistance to laundering were obtained through use of these treatments.     

Monobloc craniomaxillofacial distraction osteogenesis in a newborn with severe craniofacial synostosis: a preliminary report

Severe craniofacial synostosis can be a devastating problem for a newborn infant. Reasons for early surgical intervention include cranial stenosis, hydrocephalus, inadequate globe and corneal protection, compromised airway patency, and feeding problems. In this preliminary report, we describe the management of severe craniofacial synostosis in a newborn infant by means of cranial and midfacial distraction osteogenesis.     

Influence of high-starch vs high-fiber energy supplements on performance of stocker cattle grazing wheat pasture and subsequent feedlot performance

This study examined whether perceived risks of heart attack, cancer, and stroke were higher among smokers than nonsmokers; whether smokers were more likely to underestimate these risks; and the demographic correlates of unrealistic risk estimation among smokers. Two thousand seven hundred eight-five patients from 12 North Carolina family practices completed a questionnaire including a health risk appraisal and questions concerning smoking behavior and perceived risks of heart attack, cancer, and stroke. While most smokers accurately perceived their health risks to be greater than nonsmokers', smokers were also more likely to underestimate their risks. This optimistic distortion of risk was associated with age, gender, and education levels. Smokers may not yet understand the magnitude of health risks posed by smoking. These data suggest the need for renewed attention to perceptions of the health risks of smoking. As long as smokers underestimate their risks, they underestimate the imperative to quit.     

Studies on the surface free energy and surface structure of PTFE film treated with low temperature plasma

The surface free energy and surface structure of poly(tetrafluoroethylene) (PTFE) film treated with low temperature plasma in O₂, Ar, He, H₂, NH₃, and CH₄ gases are studied. The contact angles of the samples were measured, and the critical surface tension γ_c (Zisman) and γ_c (max) were determined on the basis of the Zisman's plots. Furthermore, the values of nonpolar dispersion force γ^a_s, dipole force γ^b_s, and hydrogen bonding force γ^c_s to the surface tensions for the plasma-treated samples were evaluated by the extended Fowkes equation. Mainly because of the contribution of polar force, the surface free energy and surface wettability of PTFE film which was treated with H₂, He, NH₃, Ar, and CH₄ for a short time increased greatly. Electron spectroscopy for chemical analysis (ESCA) shows that the reason was the decrease of fluorine and the increase of oxygen or nitrogen polar functional group on the surface of PTFE. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1733–1739, 1997     

Gene identification and DNA sequence analysis in the GC-poor 20 megabase region of human chromosome 21

In contrast to the distal half of the long arm of chromosome 21, the proximal half of approximately 20 megabases of DNA, including 21q11-21 bands, is low in GC content, CpG islands, and identified genes. Despite intensive searches, very few genes and cDNAs have been found in this region. Since the 21q11-21 region is associated with certain Down syndrome pathologies like mental retardation, the identification of relevant genes in this region is important. We used a different approach by constructing microdissection libraries specifically for this region and isolating unique sequence microclones for detailed molecular analysis. We found that this region is enriched with middle and low-copy repetitive sequences, and is also heavily methylated. By sequencing and homology analysis, we identified a significant number of genes/cDNAs, most of which appear to belong to gene families. In addition, we used unique sequence microclones in direct screening of cDNA libraries and isolated 12 cDNAs for this region. Thus, although the 21q11-21 region is gene poor, it is not completely devoid of genes/cDNAs. The presence of high proportions of middle and low-copy repetitive sequences in this region may have evolutionary significance in the genome organization and function of this region. Since 21q11-21 is heavily methylated, the expression of genes in this region may be regulated by a delicate balance of methylation and demethylation, and the presence of an additional copy of chromosome 21 may seriously disturb this balance and cause specific Down syndrome anomalies including mental retardation.     

Impact of size mismatch and left ventricular function on performance of the St. Jude disc valve after aortic valve replacement

BACKGROUND: The hemodynamic function of the St. Jude valve may change relative to changes in left ventricular function after aortic valve replacement for aortic stenosis. From theoretical reasons one may hypothesize that prosthetic valve hemodynamic function is related to left ventricular failure and mismatch between valve size and patient/ventricular chamber size. METHODS: Forty patients aged 24 to 82 years who survived aortic valve replacement for aortic stenosis with a standard St. Jude disc valve (mean size, 23.5 mm; range, 19 to 29 mm) were followed up prospectively with Doppler echocardiography and radionuclide left ventriculography preoperatively and 9 days, 3 months, and 18 months after the operation with assessment of intravascular hemolysis at 18 months. Follow-up to a maximum of 7.4 years (mean, 6.3 years) was 100% complete. RESULTS: Left ventricular muscle mass index decreased from 198 +/- 62 g.m-2 preoperatively to 153 +/- 53 g.m-2 at 18 months (p < 0.001), paralleled by a significant increase in left ventricular ejection fraction, peak ejection rate, and peak filling rate; only 18% of the patients had normal left ventricular muscle mass index and only 32% normal ventricular function (normal left ventricular ejection fraction, peak ejection rate, peak filling rate, early filling fraction, and late filling fraction during atrial contraction) at 18 months. Prosthetic valve peak Doppler gradient dropped from 20 +/- 6 mm Hg at 9 days to 17 +/- 5 mm Hg at 18 months (p < 0.05). Reduction of left ventricular muscle mass index was unrelated to peak gradient and size of the valve. Peak gradient at 18 months rose with valve orifice diameter of 17 mm or less (by 6 mm Hg), orifice diameter/body surface area of 9 mm.m-2 or less (by 5 mm Hg), left ventricular enddiastolic dimension (by 23 mm Hg per 10 mm increase), and impaired ventricular function (by 3 mm Hg). All but 2 patients (5%) had intravascular hemolysis; none had anemia. Two patients with moderate paravalvular leak had the highest serum lactic dehydrogenase levels; 4 patients with trivial leak had higher serum lactic dehydrogenase levels than those without leak. Serum lactic dehydrogenase levels rose with moderate paravalvular leak, impaired ventricular function, and valve orifice diameter. Six patients with trivial or moderate paravalvular leak had a cumulative 7-year freedom from bleeding and thromboembolism of 44% +/- 22% compared with 87% +/- 5% for those without leak (p < 0.05). CONCLUSIONS: The peak gradient of the St. Jude aortic valve dropped marginally over the first 18 postoperative months in association with incomplete left ventricular hypertrophy regression and marginal improvement of ventricular function. Mismatch between valve size and ventricular cavity size or patient size and impaired function of a dilated ventricle significantly compromised the performance of the St. Jude valve. Probably explained by platelet destruction or activation, paravalvular leak was related to bleeding and thromboembolic complications.