Reliability analysis of the Motivation Assessment Scale: a failure to replicate.

The Motivation Assessment Scale (MAS) has been proposed as an efficient questionnaire for identifying the source of reinforcement for an individual's self-injurious behavior (SIB). A previous reliability analysis of the MAS (Durand & Crimmins, 1988) reported interrater correlation coefficients ranging from .66 to .92, based on a comparison of responses provided by classroom teachers. In this study, the reliability of the MAS was reexamined with two independent groups of developmentally disabled individuals who exhibited SIB (N = 55). For the institutional sample (n = 39), the MAS was given to two staff members (a supervisor and therapy aide) who work with the individual daily. For the school sample (n = 16), the MAS was given to the teacher and teacher's aide who taught the student. The correlational analyses completed by Durand and Crimmins (1988) were repeated; in addition, a more precise analysis of interrater reliability was calculated based on the actual number of scoring agreements between the two raters. Results showed that only 16 of the 55 raters agreed on the category of reinforcement maintaining their client's or student's SIB, that only 15% of the correlation coefficients obtained were above .80, and that none of the reliability scores based on percent agreement between raters was above 80%.     

A continuous sampler with background suppression for monitoring alpha-emitting aerosol particles.

A continuous air monitor has been developed that includes provisions for improving the detection of alpha-emitting aerosol particles in the presence of radon/thoron progeny that are unattached to ambient aerosol particles. Wind tunnel tests show that 80% of 10-microns aerodynamic equivalent diameter particles penetrate the flow system from the ambient air to the collection filter when the flow rate is 57 L min-1 (2 cfm) and the wind speed is 1 m s-1. Uniformity of aerosol collection on the filter, as characterized by the coefficient of variation of the areal density deposits, is less than 15% for 10-microns aerodynamic-equivalent-diameter aerosol particles. Tests with unattached radon daughters in a flow-through chamber showed that approximately 99% of the 218Po was removed by an inlet screen that is designed to collect radon daughters that are in the size range of molecular clusters. The inlet screen offers the opportunity to improve the signal-to-noise ratio of energy spectra in the regions of interest (subranges of the energy spectrum) of transuranic elements and thereby enhance the performance of background compensation algorithms.     

Reduction of epidural fibrosis in lumbar surgery with Oxiplex adhesion barriers of carboxymethylcellulose and polyethylene oxide.

BACKGROUND CONTEXT: Postsurgical epidural adhesions and fibrosis after surgery for lumbar disc herniation are a consequence of normal wound healing. The presence of fibrosis renders reoperations risky, and in some patients fibrosis may lead to nerve root tethering. PURPOSE: One approach to minimizing the risk of developing epidural adhesions is to provide a barrier between the dural membrane and the healing connective tissues. The purpose of these studies was to evaluate such a barrier device. STUDY DESIGN/SETTING: In vivo investigation in an animal model at a university laboratory. PATIENT SAMPLE: Rabbit. OUTCOME MEASURES: Gross and histomorphic evaluation. METHODS: Barriers comprised of carboxymethylcellulose (CMC) and polyethylene oxide (PEO) (Oxiplex; FzioMed, Inc., San Luis Obispo, CA) were studied as devices to reduce epidural adhesion formation in rabbit laminotomy and laminectomy models. The barriers tested were either a gel alone (gel) or a gel covered with a film (gel/film combination). Two laminotomy or laminectomy sites (depending on the surgical method) were created in each rabbit at L4 and L6. One site was treated with a CMC/PEO gel, or CMC/PEO gel/film combination, and the other site served as a surgical control. Two surgical models that differed in the extent of adhesion formation at untreated injury sites and the method of injury generation were used. RESULTS: Model A, which did not incorporate dural abrasion, resulted in up to 40% adhesion-free laminectomy sites in controls. Model B, which did incorporate abrasion of the dural membrane, resulted in less than 10% adhesion-free laminotomy sites in controls. Compositions of CMC/PEO gels (2.5% to 10% PEO) and films (22.5% PEO) were tested in both models. Efficacy parameters included measuring the number of sites free of epidural fibrosis and reduction in the severity of fibrosis (adhesions). Both gels and gel/film combinations consistently reduced the frequency and the extent of epidural fibrosis in both models. Gels of CMC/PEO containing a higher content of PEO (10%) and a higher molecular weight of PEO (4.4 mD) were most effective in Model B and resulted in up to 84% laminotomy sites with minimal or no epidural fibrosis, whereas controls exhibited over 90% of the sites with epidural fibrosis. Histological evaluation of the surgical sites indicated that the reduction of epidural fibrosis was accompanied by normal bone healing. In addition, these experiments demonstrated that the gel/film combination provided no additional benefit to that obtained by the gel alone. CONCLUSIONS: Gels of CMC/PEO reduced epidural fibrosis and did not impair normal heal ing.     

Solitary necrotic nodule of the liver: A riddle that is difficult to answer

Solitary necrotic nodule of the liver is an unusual lesion that is often an incidental finding on abdominal imaging, intraoperative examination, or post mortem. Most reported cases of solitary necrotic nodule have been in males, and over three quarters of these lesions have occurred in the right lobe of the liver. Pathologically, solitary necrotic nodule is a benign lesion characterized by a completely necrotic core that is often partly calcified, surrounded by a dense hyalinized fibrous capsule containing elastin fibres. The ultrasound appearance of solitary necrotic nodule is usually of a “target” lesion with a hyperechoic center, while on CT scan they appear as non-enhancing hypodense lesions that are typical of metastatic adenocarcinoma or peripheral cholangiocarcinoma. The impression of malignancy is further enforced with the finding of necrotic cellular material on biopsy and the macroscopically hard and “gritty” nature of the nodules. Currently, permanent histopathology of solitary necrotic nodules is the only accurate method of diagnosis. However, solitary necrotic nodules are usually of a bilobed or lobulated shape that is unusual for malignant liver lesions, and they often lie in close proximity to hepatic inflow structures. Solitary necrotic nodule should be suspected in liver lesions with this configuration, location, and on a biopsy showing a large amount of necrosis.     

Factors affecting the development of cerebrospinal fluid leak and meningitis after translabyrinthine acoustic tumor surgery

Meningitis and cerebrospinal fluid (CSF) leak are serious complications of acoustic tumor surgery. Previous reports have varied in the incidence of and the predisposing factors to these complications. This study reviews a series of 723 acoustic tumors removed via the translabyrinthine approach at the House Ear Clinic in Los Angeles. The incidences of CSF leak and meningitis were 6.8% and 2.9%, respectively. The patients who developed these problems were compared to the remainder of the study population for differences in age at surgery, tumor size, operative time, and length of hospital stay. Meningitis occurred more frequently in larger tumors, and patients with either complication had a longer hospital stay. The presence of CSF leak did not predispose to meningitis. It is concluded that technical factors account for postoperative CSF leak and meningitis after translabyrinthine acoustic tumor removal.