Forces acting in the Milwaukee brace on patients undergoing treatment for idiopathic scoliosis.
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Adolescent↗
Biomedical subjects
A Schultz
Publications and source records attributed to A Schultz.
Effect of coconut oil on serum lipids of normal and of thyroidectomized dogs.
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Animals↗
Improved methods of estimating survival probabilities applied to renal transplant data.
In the evaluation of clinical studies of different kinds with survival time as the response variable to be analysed the estimation of survival probabilities plays an important role. The ordinary procedure in survival data analysis for estimating survival probabilities is the Kaplan-Meier product-limit estimator. However, in the case of heavy censoring or if the largest observed failure times are censored the product-limit method is known to be a biased estimator of the survival function. Recently, two improved methods of estimating survival functions, a semiparametric procedure and an approach using splines, were proposed (Klein JP, Lee SC and Moeschberger ML, Biometrics, 46 (1990) 795-811; Whittemore AS and Keller JB, Biometrics, 42 (1986) 495-506). These new methods are less biased than the product-limit estimator, especially for heavily censored data. A computer program based on the integrated statistical and graphical software package RS/1 was developed for the calculation and graphical representation of the new estimators. Their improved properties are illustrated by the application to renal transplant data.
Computer Graphics↗
Vasculopathic changes of CADASIL can be focal in skin biopsies.
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a newly described cause of vascular dementia. Pathologic examination shows multiple small infarcts in the deep cerebral white matter together with a nonatherosclerotic, nonamyloid angiopathy involving the media of small cerebral arteries. Ultrastructurally, characteristic granular material is present in the basal lamina of vascular smooth muscle cells in cerebral and extracerebral blood vessels. The ultrastructural changes have also been demonstrated in skin biopsies of affected patients; consequently, some investigators have recently recommended skin biopsies for the diagnosis of CADASIL. This study describes a 54-year-old male with a family history for strokes who had clinical and radiological features suggestive of CADASIL. A skin biopsy was performed to confirm the diagnosis. Initially, the characteristic vasculopathic changes of CADASIL were not identified within small blood vessel walls. However, multiple deeper sections in other areas showed electron-dense material associated with vascular smooth muscle cells, characteristic of CADASIL. Subsequent genetic testing demonstrated a single nucleotide substitution at position 659 on chromosome 19p13.1 causing an amino-acid change (Cys --> Phe), a finding indicative of CADASIL. The involvement of blood vessels within the dermis makes skin biopsy a useful adjunct in the diagnosis of CADASIL. However, as illustrated by this case, the findings may be focal, requiring a thorough evaluation of the entire biopsy specimen.
Biopsy↗
Voluntary strengths of male adults with acute low back syndromes.
Hand forces exerted in 120 different combinations of foot positions, hand positions, and force directions were measured in a group of 15 male adults with acute low-back syndromes. The performances of these patients were contrasted with those of 29 healthy male adults who had been tested earlier. The major findings were: acute back syndrome patients, sometimes even including those with very severe pain, have considerable physical ability in many of the situations examined, often fully comparable to that of healthy subjects; generally, either patients were unable even to assume a given position, or else their performances were close to normal in all exercises in each position; the positions which a significant number of patients could not assume were those involving substantial trunk twisting, or combinations of bending and twisting.
Adult↗
Trunk strengths in attempted flexion, extension, and lateral bending in healthy subjects and patients with low-back disorders.
Trunk strengths were measured in 27 health males and 30 health females, and in 25 male and 15 female patients with low-back pain and/or sciatica. Maximum voluntary isometric strengths were measured during attempted flexion, extension, and lateral bending from an upright standing position. Both male and female patients had approximately 60% of the absolute trunk strengths of the corresponding healthy subjects. Intra-individual trunk strength ratios were used to interpret the results. Use of these ratios tends to avoid interpretational problems created by the general weakness of the patients and any lack of motivation of either patients or healthy subjects. The ratios showed that the patients had attempted extension strengths that were significantly less than their strengths in the other types of movements tested. The strength ratios for attempted extension were particularly low for patients with sciatica.
Adult↗
Trunk strengths in patients seeking hospitalization for chronic low-back disorders.
Trunk strengths of 16 male and 17 female patients with chronic low-back disorders were measured. The patients sought hospitalization for four weeks in a pain clinic. Maximum voluntary trunk strengths in the standing position were measured during attempted flexion, extension, and lateral bending. The trunk strengths of these patients were then compared with those of health subjects and with those of patients with low-back disorders who sought treatment as outpatients of a general orthopaedic office practice. In making the comparisons, intra-individual trunk-strength ratios were used to overcome problems due to the effects of patients' general weakness and any psychologic factors. When compared with healthy subjects, the patients seeking hospitalization had significantly smaller strengths during attempted extension relative to their strengths during attempted flexion or lateral bending. Their trunk-strength ratios did not differ significantly from those of the outpatient group.
Adult↗
Roentgenographic measurement of lumbar intervertebral disc height.
The influences of differences in both intervertebral motion segment orientations and in reader judgments on measurements of the apparent intervertebral disc heights in lateral roentgenographs of the lumbar spine were examined. Forty-nine roentgenographs were obtained of nine discs that were titled laterally up to +/- 10 degrees, and rotated longitudinally up to +/- 20 degrees. Three orthopaedic surgeons and three radiologists measured disc heights from five of these roentgenographs, all using the same measurement method. The differences in apparent height that resulted from the orientation changes and differences in judgments among the six readers were considerable, usually of the order of one half of the nominal disc height. The results show that, while roentgenographic measurements can be used to estimate disc height, accurate measurements cannot readily be made from routine roentgenographs, and the interpretation should always be cautious.
Adult↗
Correction of scoliosis by muscle stimulation: biomechanical analyses.
Quantitative theoretical analyses of the ability of trunk muscle contraction forces to reduce lateral curves in the spine are presented. The effects of contraction of each of 68 muscle slips on each of 13 configurations of scoliosis were examined using biomechanical models of the trunk. The lateral curve, sagittal curve, and longitudinal axis rotation changes that resulted from contraction of these muscles were determined in each case. The muscles best able, from a biomechanical viewpoint, to reduce different lateral curves are listed. Effects of initial postural configurations and the consequences of reflex attempts to right the trunk after contracting a trunk muscle are described. Substantial changes in spine configuration can result from trunk muscle contractions of even modest intensity.
Abdominal Muscles↗
Analysis and quantitative myoelectric measurements of loads on the lumbar spine when holding weights in standing postures.
Ten subjects executed a number of weight-holding and force-resisting work tasks while standing either upright or with their trunks in 30 degrees of forward flexion. All tasks involved sagitally symmetric body configurations and were performed isometrically. A simple calculation scheme was devised to predict the lumbar trunk muscle contraction forces and the lumbar spine compression forces required for execution of each task. The myoelectric activity was recorded quantitatively at eight sites over the lumbar trunk muscles and at four sites over the abdominal muscles. Good correlation was found between the predicted muscle contraction forces and the myoelectric activities.
Adult↗
Trunk strengths in structurally normal girls and girls with idiopathic scoliosis.
Maximum voluntary isometric strengths of the trunk were measured in 93 girls who had mild idiopathic scoliosis and 109 girls who had structurally normal spines. Subject ages ranged from 10 to 16 years, and the mean Cobb measurement in the girls with scoliosis was approximately 22 degrees. Strengths were measured in attempted trunk flexion, attempted extension, ad attempted left and right lateral bending. No consistent differences appeared in performance between the girls with scoliosis and the structurally normal girls.
Adolescent↗
Trunk muscle myoelectric activities in idiopathic scoliosis.
Twenty adolescent girls with mild-to-moderate cases of idiopathic scoliosis and twelve adolescent girls with structurally normal spines performed 15 exercises isometrically while standing. The exercises included resisting flexion, extension, and lateral bending moments imposed on the trunk. Myoelectric activities in 12 trunk muscle groups were measured during these performances, using surface electrodes. For one set of comparisons, the patients were divided into those whose clinical records documented curve progression and those with no documented progression. No significant differences were noted in mean myoelectric activities between these two patient groups. For a second set of comparisons, the subjects were divided into patients with curves of more than 25 degrees, patients with curves of 25 or fewer degrees and normals. No significant differences in mean myoelectric activities were noted between the patients with the smaller curves, while the patients with the larger curves had significantly larger convex side myoelectric activities in their anterior, lateral and posterior muscles at lumbar levels compared to the normal girls. The findings of this study, along with biomechanical model analyses, suggest that the asymmetries in muscle actions evidenced by myoelectric measurements result from scoliosis. Scoliosis progression seems not to be caused by asymmetry in muscle contractions; rather it may be caused by a lack of adequate asymmetry.
Abdominal Muscles↗
Clinical islet transplantation--registry report, accomplishments in the past and future research needs.
This review provides the results of a recent analysis of the Islet Transplant Registry on clinical adult islet transplants performed worldwide through June 30, 1992. Between December 12, 1893 and June 30, 1992, 167 adult islet transplants were performed at 25 institutions worldwide, including 104 at 9 institutions in North America, 62 at 15 institutions in Europe, and 1 elsewhere. The total number of diabetic patients reported to be insulin independent after adult islet allotransplantation through June 30, 1992, was 19. In an analysis by era, the percentage of patients that showed positive basal C-peptide levels (i.e., > or = 1 ng/mL at > or = 1 mo) posttransplant, and that became insulin independent (> 1 wk) in the 1985-1989 era (n = 35 cases) were 20% and 6%, and in the 1990-1992 era (n = 69 cases) were 64% and 20%, respectively, and thus have improved significantly (p < 0.001 and p < 0.05). For the 1990-1992 period, the percentage of patients who showed positive basal C-peptide levels post-transplant, and who became insulin independent in the single donor pancreas group (n = 31 cases) were 52% and 13%, and in the multiple donor pancreata group (n = 36 cases) were 75% and 28%, respectively. Islet graft function rates were nearly identical for grafts prepared from pancreata stored < or = 6 h (n = 27) and > 6 < or = 12 h (n = 29), so that 67% and 72% showed positive basal C-peptide levels, and 30% and 21% of the recipients became insulin independent, respectively. No single patient showed islet graft function sufficient to allow withdrawal from insulin, if the pancreata have been stored for more than 12 h. In regard to recipient category for the six groups, namely IAK (islet after kidney), SIK (simultaneous islet kidney transplantation), SIL (simultaneous islet liver transplantation), SIL(C) (simultaneous islet liver transplantation after cluster operation), SIKL (simultaneous islet kidney liver transplantation), and SIH-L (simultaneous islet heart-lung transplantation), the number of patients who showed positive basal C-peptide levels post-transplant was 11 (58%), 17 (57%), 5 (83%), 8 (80%), 1 (50%), and 0 (0%), and the number of insulin independent patients was 4 (21%), 4 (13%), 0 (0%), 6 (60%), 0 (0%), and 0 (0%), respectively. Comparing the two largest recipient categories, namely IAK and SIK, no difference in the outcome of these transplants was apparent.(ABSTRACT TRUNCATED AT 400 WORDS)
Adult↗
Automatic classification algorithms of the EEG monitor Narcotrend for routinely recorded EEG data from general anaesthesia: a validation study.
Impacts of hypnotic drugs on brain function are reflected in the EEG. The EEG monitor Narcotrend performs an automatic classification of the EEG using a scale which was proposed by Kugler for visual evaluation of the EEG. In this article the results of a validation study of the automatic classification algorithms implemented in the EEG monitor Narcotrend are presented. Visual and automatic classification of EEG data recorded in routine clinical practice were compared. The correlation between visual and automatic assessment was high (Spearman rank correlation r = 0.90, prediction probability Pk = 0.90) and a sufficient agreement between visual and automatic assessment was achieved for 92% of the analysed EEG epochs. The results of the study suggest that the automatic classification algorithms implemented in the EEG monitor Narcotrend yield a reliable assessment of the depth of hypnosis.
Algorithms↗
University affiliated programs: a network of nursing resources for children and youth with disabilities.
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Child↗
VIDAS enzyme-linked immunoflourescent assay for detection of Listeria in foods: collaborative study.
The VIDAS LIS method and the traditional culture methods for detection of Listeria species in food were evaluated in a multilaboratory comparative study. The 6 foods tested were either naturally contaminated or inoculated with 3 different concentrations of Listeria. Results for each food and each contamination level with the VIDAS LIS method were as good as or better than those obtained with the traditional culture method. Of 1558 samples tested, 935 were positive: 839 by the VIDAS method and 809 by standard culture methods. Overall false negative rates were 10.3 and 13.5% for the VIDAS LIS and culture methods, respectively. The false positive rate for the VIDAS LIS assay was 1.4% based on 9 VIDAS LIS positive assays that did not confirm positive by isolation of Listeria. The agreement between the VIDAS LIS and culture methods for all samples tested was 86%.
Animals↗
Evaluation of the BAX system for detection of Listeria monocytogenes in foods: collaborative study.
A multilaboratory study was conducted to compare the automated BAX system and the standard cultural methods for detection of Listeria monocytogenes in foods. Six food types (frankfurters, soft cheese, smoked salmon, raw, ground beef, fresh radishes, and frozen peas) were analyzed by each method. For each food type, 3 inoculation levels were tested: high (average of 2 CFU/g), low (average of 0.2 CFU/g) and uninoculated controls. A total of 25 laboratories representing government and industry participated. Of the 2335 samples analyzed, 1109 were positive by the BAX system and 1115 were positive by the standard method. A Chi square analysis of each of the 6 food types, at the 3 inoculation levels tested, was performed. For all foods, except radishes, the BAX system performed as well as or better than the standard reference methods based on the Chi square results.
Chi-Square Distribution↗
Evaluation of the VIDAS Listeria (LIS) immunoassay for the detection of Listeria in foods using demi-Fraser and Fraser enrichment broths, as modification of AOAC Official Method 999.06 (AOAC Official Method 2004.06).
A multilaboratory study was conducted to compare the VIDAS LIS immunoassay with the standard cultural methods for the detection of Listeria in foods using an enrichment modification of AOAC Official Method 999.06. The modified enrichment protocol was implemented to harmonize the VIDAS LIS assay with the VIDAS LMO2 assay. Five food types--brie cheese, vanilla ice cream, frozen green beans, frozen raw tilapia fish, and cooked roast beef--at 3 inoculation levels, were analyzed by each method. A total of 15 laboratories representing government and industry participated. In this study, 1206 test portions were tested, of which 1170 were used in the statistical analysis. There were 433 positive by the VIDAS LIS assay and 396 positive by the standard culture methods. A Chi-square analysis of each of the 5 food types, at the 3 inoculation levels tested, was performed. The resulting average Chi square analysis, 0.42, indicated that, overall, there are no statistical differences between the VIDAS LIS assay and the standard methods at the 5% level of significance.
Animals↗