PubMed Health⌕ Search

Biomedical subjects

M J Bookbinder

Publications and source records attributed to M J Bookbinder.

6 recordsLinked to original sources
PubMed1990

Peripheral neuropathy associated with alpha 1-antitrypsin deficiency.

Peripheral neuropathy associated with alpha 1-antitrypsin deficiency is an uncommon condition. Several recent studies have investigated the possible roles of serum proteinase inhibitors in inflammatory neuropathies, such as multiple sclerosis, Landry-Guillain-Barré syndrome, and various chronic inflammatory demyelinating peripheral neuropathies. We present a case in which alpha 1-antitrypsin deficiency (proteinase inhibitor ZZ phenotype) was diagnosed in a young white man with clinical signs and symptoms of peripheral neuropathy and a history of Landry-Guillain-Barré syndrome. We wish to emphasize the importance of serum protein electrophoresis in the diagnostic workup of patients presenting with the clinical manifestations of peripheral neuropathy.

Adult↗
PubMed1988

Detection of renal masses: sensitivities and specificities of excretory urography/linear tomography, US, and CT.

A prospective blinded study of 201 patients was performed to determine the relative sensitivities and specificities of excretory urography/linear tomography (EU/LT) and ultrasound (US) for the diagnosis of renal parenchymal masses. Computed tomography (CT) was used as a standard. EU/LT permitted detection of 10% of CT-confirmed masses (cystic or solid) less than 1 cm, 21% of lesions greater than or equal to 1 cm but less than 2 cm, 52% of lesions greater than or equal to 2 cm but less than 3 cm, and 85% of lesions 3 cm or more in diameter. US permitted detection of 26% of CT-confirmed lesions less than 1 cm, 60% of lesions greater than or equal to 1 cm but less than 2 cm, 82% of lesions greater than or equal to 2 cm but less than 3 cm, and 85% of lesions 3 cm or more in size. The results confirm the relative insensitivity of EU/LT for masses less than 3 cm in diameter and of US for masses less than 2 cm. Further, they suggest that CT may have a role not only in evaluation of cases in which the urographic or sonographic results are questionable or positive, but also in confirmation of apparently negative urographic findings when clinical suspicion of a lesion is high.

Carcinoma, Renal Cell↗
PubMed1987

Dissociation of electrophysiologic and pharmacologic stability during an abbreviated oral loading regimen of amiodarone.

Thirty-three patients treated with an abbreviated oral amiodarone loading regimen for ventricular tachycardia underwent electrophysiologic testing in the control state, after 1 week of high-dose (1170 +/- 88 mg/day) inpatient therapy; and after an 8-week intermediate (669 +/- 129 mg/day) dosing phase. Serum levels of amiodarone and desethylamiodarone were measured by high-pressure liquid chromatography during follow-up electrophysiologic studies. Although the corrected sinus node recovery time, sinoatrial conduction time, and AH and HV intervals remained unchanged throughout the loading period, the sinus cycle length, Wenckebach cycle length, atrial and ventricular refractory periods, and ventricular tachycardia mean and return cycle lengths lengthened significantly by 1 week. They then remained stable for the remainder of the treatment period (control less than 1 and 8 weeks, p less than 0.05). In contrast, amiodarone and especially desethylamiodarone levels rose from 1 to 8 weeks: 1.29 +/- 0.56 to 1.97 +/- 0.90 micrograms/ml (p = 0.001) and 0.63 +/- 0.29 to 1.29 +/- 0.61 micrograms/ml (p less than 0.0001), respectively. Because this regimen produces relatively prompt electrophysiologic changes, which then stabilize, early outpatient management becomes feasible before pharmacologic steady state is attained.

Aged↗
PubMed1987

Using the coefficient of correlation in method-comparison studies.

The coefficient of correlation (R) is one of the most commonly computed statistics in method-comparison studies. Usually, it is simply quoted without interpretation. In this paper, we show how R may be used to detect interference, nonlinearity, and misuse of the imprecision components. Specifically, one may precisely predict what R should be by considering the imprecisions of the two methods being compared, even before the comparison is performed. When the actual R disagrees with the predicted R, then one of the mentioned effects is present. We also describe a statistical test to detect these effects at the P = 0.05 level, then evaluate this test by using computer simulation and present two examples of its use. We also present the theory underlying the usage of R, including how R is affected by the distribution and range of the data, by the joint imprecisions of the methods being compared, by the sample size, and by the randomness of the specimen-selection process.

Autoanalysis↗
PubMed1986

Correct and incorrect estimation of within-day and between-day variation.

Between-day variance is an ambiguous term representing either total variance or pure between-day variance. In either case, it is often incorrectly calculated even though analysis of variance (ANOVA) and other excellent methods of estimation are available. We used statistical theory to predict the magnitude of error expected from using several intuitive approaches to estimation of variance components. We also evaluated the impact of estimating the total population variance instead of pure between-day variance and the impact of using biased estimators. We found that estimates of variance components could be systematically biased by several hundred percent. On the basis of these results, we make recommendations to remove these biases and to standardize precision estimates.

Analysis of Variance↗