The precision of practice analysis results in the professions

A practice analysis, in which an appropriate sample of professionals is asked to describe what they do in their practices, is considered an essential part of the content-related validity evidence for licensure and certification tests. This article examines the precision of estimates of the mean frequencies for categories of activities in an activity inventory administered on two occasions about 6 weeks apart. In particular, it explores the variability in estimates of the mean frequencies for categories due to the sampling of respondents, activity statements, and occasions. The results suggest that samples of 200 respondents, about 10 to 20 activity statements per category, and one occasion are adequate for estimating the mean frequency for each category.

Optical Properties of the South Pole Ice at Depths Between 0.8 and 1 Kilometer

The optical properties of the ice at the geographical South Pole have been investigated at depths between 0.8 and 1 kilometer. The absorption and scattering lengths of visible light ( approximately 515 nanometers) have been measured in situ with the use of the laser calibration setup of the Antarctic Muon and Neutrino Detector Array (AMANDA) neutrino detector. The ice is intrinsically extremely transparent. The measured absorption length is 59 +/- 3 meters, comparable with the quality of the ultrapure water used in the Irvine-Michigan-Brookhaven and Kamiokande proton-decay and neutrino experiments and more than twice as long as the best value reported for laboratory ice. Because of a residual density of air bubbles at these depths, the trajectories of photons in the medium are randomized. If the bubbles are assumed to be smooth and spherical, the average distance between collisions at a depth of 1 kilometer is about 25 centimeters. The measured inverse scattering length on bubbles decreases linearly with increasing depth in the volume of ice investigated.

Impact of parental smoking on the prevalence of wheezing respiratory illness in children

To quantitatively assess environmental tobacco smoke exposure from parental smoking as a risk factor for asthma or wheezing in childhood, and to derive estimates of excess asthma/wheezing lower respiratory tract illness cases attributable to this risk factor, a cross-sectional analysis of the 1987 National Medical Expenditure Survey (a national probability sample of the civilian, noninstitutionalized US population) was undertaken. The National Medical Expenditure Survey included 7,578 children and youth less than 18 years of age in a stratified cluster sampling of US households. After using logistic regression analysis to control for sex, race/ethnicity, region of residence, population density, poverty status, maternal educational level, family size, and father's current smoking status, children whose mothers smoked at the time of the survey were more likely than children of nonsmoking mothers to experience wheezing respiratory illness (odds ratio = 1.36, 95% confidence interval 1.14-1.62). The association was greatest among children less than 2 years of age. The authors' estimate of the attributable risk in the US population indicates that maternal smoking is responsible for approximately 380,000 excess cases of childhood asthma/wheezing lower respiratory tract illness or 7.5% of the total number of such symptomatic children.

Unreliability of the abdominal fat pad biopsy in the evaluation of nephrosis: report of 3 consecutive cases

In the workup of unexplained nephrotic syndrome in the elderly patient, renal biopsy has shown amyloidosis to be the cause in 15-30% of the cases. Most of the cases of amyloidosis are primary and are, therefore, treatable with alkylating agents, albeit at a high level of toxicity. Abdominal fad pad biopsy has been suggested as a minimally invasive, low-cost method for diagnosing amyloidosis that is 100% specific. We report our experience with 3 consecutive cases of fat pad biopsy in the workup of unexplained nephrosis in the elderly patient: including the first false positive reported with respect to nephrotic renal disease, a false negative, and a true positive. We feel that in an elderly patient with unexplained nephrosis though the abdominal fat pad biopsy may be helpful, the patient should not be committed to a regimen with potentially very high toxicity on the basis of a positive fat pad biopsy alone. We recommend that the more invasive renal biopsy be performed should therapy with alkylating agents be contemplated.

Independent and coordinate regulation of beta 1- and beta 2-adrenergic receptors in rat C6 glioma cells

Rat C6 glioma cells have both beta 1- and beta 2-adrenergic receptors in approximately 7:3 ratio. When the cells were exposed to the beta-adrenergic agonist isoproterenol, there was a rapid sequestration of up to 50% of the surface receptor population over a 30-min period as measured by the loss of binding of the hydrophilic ligand [3H] CGP-12177 to intact cells. Using the beta 1-selective antagonist CGP 20712A to quantify the proportion of the two subtypes, it was found that although both beta 1 and beta 2 receptors were sequestered, the latter were sequestered initially twice as fast as the former. More prolonged agonist exposure led to a down-regulation of approximately 90% of the total receptor population by 6 h as measured by the loss of binding of the more hydrophobic ligand [125I]iodocyanopindolol to cell lysates. The two subtypes, however, underwent down-regulation with similar kinetics. Treatment of the cells with agents that raise cyclic AMP levels such as cholera toxin and forskolin resulted in a slower, but still coordinated down-regulation of both subtypes. Thus, there appears to be both independent and coordinate regulation of endogenous beta 1-and beta 2-adrenergic receptors in the same cell line.

Toward a comprehensive biomechanical injury cost model

The proposed biomechanical injury cost model utilizes surrogate-based injury assessment functions to predict the probability of occurrence and the probable cost of specific injuries to the head, thorax, abdomen, and lower extremities. The resulting probability cost is a function of the number, location, and severity of injuries. As more precise injury assessment functions and more accurate cost estimates become available, the model will become an effective tool for comparing and classifying different injury patterns.

Cloning and sequence analysis of the spike gene from several feline coronaviruses

The DNA sequence encoding the spike gene from the DF2 strain of Type II feline infectious peritonitis virus (FIPV), a temperature sensitive FIPV virus (TS-DF2) and an isolate of feline enteric coronavirus (FECV 1683) were determined. Comparison of the published WSU 1146 and DF2 FIPV S genes showed that the viruses shared a high degree of homology (99.6%). Likewise, the S gene of the virulent DF2 FIPV virus was closely conserved to that isolated from the vaccine virus strain, TS-DF2 FIPV. In contrast, the FECV S gene had numerous DNA and amino acid differences when compared to the virulent FIPV sequences. Sequence differences among the feline coronavirus isolates were localized to the amino-terminus region of the S gene.

Death-induced changes to the nuclear matrix: the use of anti-nuclear matrix antibodies to study agents of apoptosis

Using immunological techniques, we have shown for the first time that change in the nuclear matrix is an observable step in the cell death program. Immunometric assays detect soluble nuclear matrix proteins in the culture supernatants of cells killed by adriamycin, tumor necrosis factor and serum growth factor deprivation. Studies of cells killed by tumor necrosis factor and serum growth factor deprivation using dual immunofluorescent and 4'-6-diamidino-2-phenylindole (DAPI) staining detect many cells strongly positive for DNA that have little or no nuclear matrix protein. The staining pattern of cells killed by adriamycin is very different. There is good correspondence between the immunofluorescent and DAPI staining patterns indicating the presence of nuclear matrix proteins and DNA, although at a reduced ratio. It is concluded that the nuclear matrix changes are dependent on the agents that trigger cell death.

Orbital pseudotumor. Fine-needle aspiration biopsy and response to therapy

PURPOSE

To determine the diagnostic accuracy of fine-needle aspiration biopsy and study the natural history and therapeutic response of a group of patients with orbital pseudotumor.

METHODS

Retrospective review of patients seen by one ocular oncologist for diagnosis and management of presumed orbital pseudotumor.

RESULTS

Thirty-eight patients had fine-needle aspiration biopsy under computed tomographic (CT) guidance. No false-positive results were observed. In 10% of fine-needle aspiration biopsies, negative results were observed. In all patients in this series, lymphomas could be differentiated from pseudotumors. Flow cytometry or Southern blot analysis could be performed on these cytopathologic specimens and was useful in selected cases. Eighty-one patients were followed after various forms of treatment. Essentially complete remissions were observed in 49 of 81 patients. High-dose oral corticosteroids were effective in approximately 31% of patients. A poor steroid response was observed in patients with mass lesions and those with fibrotic disease. Surgical resection was effective in 76% of patients; most of these had relatively discrete mass lesions. Radiation was effective in approximately 64% of patients. Radiation was more effective in nonfibrotic lesions and in patients with erythema. This type of treatment was less effective in fibrotic lesions and in patients who had a longer interval between diagnosis and therapy.

CONCLUSIONS

Fine-needle aspiration biopsy is useful in evaluating patients with presumed orbital pseudotumor. There is a high success rate in many patients with orbital pseudotumor, although patients with diffuse fibrotic disease have a poor prognosis.