Image enhancement of severely hypoperfused myocardia for computation of tomographic ejection fraction

Ejection fractions computed from 99mTc-sestamibi myocardial perfusion gated tomograms have demonstrated a high degree of accuracy and reproducibility. Although automated algorithms appear to provide reasonable endocardial outlines for patients over a broad spectrum of cardiac diseases, in cases of severe hypoperfusion, it is necessary to manually adjust contrast and brightness to judge whether borders are correct or must be altered. METHODS: Midventricular horizontal and vertical long axis gated tomograms were generated for 116 studies chosen on the basis of extensive, severe myocardial perfusion defects. Automated software transformed cinematic tomograms into images demonstrating uniform appearance of the myocardium throughout the cardiac cycle. Transformed images were introduced to edge detection algorithms for subsequent calculation of ventricular volumes and ejection fractions. RESULTS: Linear regression analysis demonstrated excellent intraobserver reproducibility for ejection fractions (r = 0.95) and volumes (r = 0.98). There was also good agreement of ejection fractions (r = 0.86) and volumes (r = 0.94) with values derived from an expert's manual drawings. In a subgroup of 22 patients, automated ejection fractions from transformed images demonstrated better agreement with independent first-pass values (r = 0.90) than did manual measurements derived from original data (r = 0.85). CONCLUSION: Image enhancement algorithms succeeded in providing accurate, reproducible gated SPECT ejection fractions in the most difficult class of patients exhibiting severe hypoperfusion.     

Operative resection of 100 spinal lipomas in infants less than 1 year of age

A retrospective analysis of 100 children followed at Children's Memorial Hospital, Chicago, who underwent surgery for a spinal lipoma was performed. The mean follow-up was 5 years. We found that an operation performed during the 1st year of life with the goal of untethering the spinal cord and debulking the spinal lipoma was safe and effective, whereas a cosmetic (nonuntethering) procedure always led to delayed postoperative deterioration (symptomatic tethered cord). Of the infants that presented with motor, urologic or orthopedic symptoms, 39% improved, 58% stabilized, while 3% worsened as a result of surgery. No asymptomatic infant deteriorated postoperatively and 93% of these children remained symptom-free at follow-up (mean follow-up was 44 months). The overall outcome of infants after untethering procedures in this study was significantly better than the natural history of spinal lipomas. Several risk factors were identified that may predispose children to delayed postoperative deterioration: an initial cosmetic procedure; the presence of preoperative symptoms, and the presence of a lipomyelomeningocele.     

Mutations in the p16INK4/MTS1/CDKN2, p15INK4B/MTS2, and p18 genes in primary and metastatic lung cancer

We examined the genomic status of cyclin-dependent kinase-4 and -6 inhibitors, p16INK4,p15INK4B, and p18, in 40 primary lung cancers and 31 metastatic lung cancers. Alterations of the p16INK4 gene were detected in 6 (2 insertions and 4 homozygous deletions) of 22 metastatic non-small cell lung cancers (NSCLCs; 27%), but none were detected in 25 primary NSCLCs, 15 primary small cell lung cancers (SCLCs), or 9 metastatic SCLCs, indicating that mutation in the p16INK4 gene is a late event in NSCLC carcinogenesis. Although three intragenic mutations of the p15INK4B gene were detected in 25 primary NSCLCs (12%) and five homozygous deletions of the p15INK4B gene were detected in 22 NSCLCs (23%), no genetic alterations of the p15INK4B gene were found in primary and metastatic SCLCs. The p18 gene was wild type in these 71 lung cancers, except 1 metastatic NSCLC which showed loss of heterozygosity. We also examined alterations of these three genes and expression of p16INK4 in 21 human lung cancer cell lines. Alterations of the p16INK4 and p15INK4B genes were detected in 71% of the NSCLC cell lines (n = 14) and 50% of the NSCLC cell lines (n = 14), respectively, but there were none in the 7 SCLC cell lines studied. No p18 mutations were detected in these 21 cell lines. These results indicate that both p16INK4 and p15INK4B gene mutations are associated with tumor progression of a subset of NSCLC, but not of SCLC, and that p15INK4B mutations might also be an early event in the molecular pathogenesis of a subset of NSCLC.     

Perceptions of life stress and chronic insomnia in older adults.

This study compared the level of self-reported stress of 42 older good sleepers (M age?=?68.2 years) and 42 poor sleepers (M age?=?68.7 years). The relations among subjective ratings of sleep, level of perceived stress, and negative mood were analyzed for each group. Good and poor sleepers reported similar amounts of life stress, but the relations between life stress and sleep perceptions differed for the 2 groups. Specifically, within the group of poor sleepers, those with higher life stress had greater difficulty falling asleep and less early morning waking than did poor sleepers with lower life stress. There was no association between life stress and any sleep measures for good sleepers. These results are compatible with the notion that good and poor sleepers may have different susceptibilities to poor sleep despite experiencing similar stressful life events. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cerebellar growth in normal and growth-restricted fetuses of multiple gestations

OBJECTIVE: Our purpose was to evaluate growth of the cerebellum in growth-restricted fetuses of twin and triplet gestations versus growth in normal in utero sibling(s) and in singleton gestations. STUDY DESIGN: An ultrasonographic study was conducted in a population of pregnant women with twin and triplet gestations. The control group was either the normal in utero sibling(s) when one fetus was growth restricted or normal twin and singleton pregnancies. Standard biometric measurements were obtained on all fetuses throughout pregnancy, including the transverse cerebellar diameter. However, only the last measurement was used for the analysis. Statistical analyses were conducted comparing growth of the transverse cerebellar diameter among the growth-restricted fetuses versus growth in the normal in utero fetal sibling(s) or other normal twin and singleton gestations. RESULTS: Pregnancies were categorized on the basis of the growth status of women with twin and triplet gestations: Group 1 (151) contained women with two fetuses appropriately grown for gestational age; group 2 (52) had one appropriately grown fetus and one with intrauterine growth restriction; group 3 (19) had two fetuses with intrauterine growth restriction. In addition, there were 30 triplet gestations (group 4), five of which had growth-restricted fetuses, and group 5 contained 1405 singleton pregnancies. In all five groups there was a statistically significant relationship between transverse cerebellar diameter and gestational age (p < 0.0001). There was also no significant difference between growth of the transverse cerebellar diameter in the appropriately grown and growth-restricted siblings and among normal singleton and twin pregnancy groups. In most cases of growth-restricted fetuses, except for the transverse cerebellar diameter measurements, all other biometric parameters were < 10th percentile. CONCLUSION: These data confirm the relative preservation of normal cerebellar growth in growth-restricted fetuses and a similar rate of growth in singleton and multifetal gestations. The transverse cerebellar diameter therefore represents an independent biometric parameter that can be used in both singleton and multifetal pregnancies to assess normal and deviant fetal growth.     

Pediatric cardiopulmonary bypass: a review of current practice

Devices and techniques used for pediatric cardiopulmonary bypass are ever changing. There are frequently reports in the literature about new techniques and new devices. Periodic surveys are helpful because they reveal the actual extent to which these techniques and devices are applied to clinical practice. Advances in research are bringing about a better understanding of the intricate aspects of CPB and the effects of CPB on pediatric patients. There appears to be a trend from widely divergent approaches to CPB for pediatric patients to more uniformity in practice. For example, the use of membrane oxygenation and arterial line filtration has become universal, and there is an increase in the use of all types of safety devices. Techniques reported in the medical literature at the beginning of the decade, such as, the use of modified ultrafiltration, the use of centrifugal cell washers to process packed red blood cells before adding them to the prime, and the use of the antifibrinolytic drug, aprotinin, have become part of practice at a large number of pediatric heart centers. Periodic surveys are useful, as they provide a measurement of current practice. They also provide a historical record of the advances in the field.     

Effects of an impulse magnetic field on lipid peroxidation and the antioxidant system of the testes in animal experiments

The study covered influence of impulse magnetic field on lipid peroxidation and antioxidant defence in seminal tissue of rats. Monthly exposure to the impulse magnetic field (intensity of 30 kA/m; impulse frequency of 2.5 and 25 kHz) activated initial, intermediate and final stages of lipid peroxidation, increased non-enzymatic (ascorbic acid) defence systems and depressed the enzymatic (glutathione peroxidase, catalase) ones. The aftereffects included changes in the lipid peroxidation and in levels of antioxidant factors in the seminal tissue.