Clinical Experiences High‐flux hemodialysis in the treatment of severe valproic acid overdose: A case report

Introduction:  Hemoperfusion, with or without hemodialysis, has been used to treat patients suffering from severe valproic acid poisoning. We report a patient suffering from severe valproic acid intoxication who was treated effectively with high‐flux hemodialysis alone. Case:  A 20‐year‐old man with a history of bipolar disorder was admitted after having ingested unknown amounts of valproic acid (Depakote®), prednisone, and erythromycin. He was agitated and obtunded but hemodynamically stable initially. Serum valproic acid level was 1,028 μg/mL. Urine toxicology screen as well as serum levels of ethanol, acetaminophen, and acetylsalicylic acid levels were negative. A gastric lavage was followed by activated charcoal instillation. Subsequent myoclonic twitchings that progressed to continuous seizure activity were managed with intravenous lorazepam therapy and endotracheal intubation. Serum valproic acid value measured two hours after admission remained elevated at 1,046 μg/mL. Hemodialysis was performed continuously for 10.5 hours using a high‐flux, polysulfone dialyzer (Polyflux 21S, Fresenius Medical Care, Lexington, MA), a dialyzer blood flow of 200–300 mL/min, and a dialysate flow of 500 mL/min. The therapy brought about a fall in serum valproic acid level to 110 μg/mL and a complete recovery of the patient. Discussion:  Valproic acid (144 Dalton) is 90–95% protein‐bound at therapeutic serum values. However, in the face of an overdose, the unbound fraction rises because of saturation of protein‐binding sites. This unbound fraction is readily dialyzable. We suggest that high‐flux hemodialysis is effective in the treatment of severe valproic acid poisoning.     

Classification of bacteria responsible for ENT and eye infections using the Cyranose system

The Cyranose 320 (Cyrano Sciences Inc., USA), comprising an array of 32 polymer carbon black composite sensors, has been used to identify species of bacteria commonly associated with medical conditions. Results from two experiments are presented: one on bacteria causing eye infections and one on a new series of tests on bacteria responsible for some ear, nose, and throat (ENT) diseases. For the eye bacteria tests, pure lab cultures were used and the electronic nose (EN) was used to sample the headspace of sterile glass vials containing a fixed volume of bacteria in suspension. For the ENT bacteria, the system was taken a step closer toward medical application, as readings were taken from the headspace of the same blood agar plates used to culture real samples collected from patients. After preprocessing, principal component analysis (PCA) was used as an exploratory technique to investigate the clustering of vectors in multi-sensor space. Artificial neural networks (ANNs) were then used as predictors, and a multilayer perceptron (MLP) trained with back-propagation (BP) and with Levenberg-Marquardt was used to identify the different bacteria. The optimal MLP was found to correctly classify 97.3% of the six eye bacteria of interest and 97.6% of the four ENT bacteria including two sub-species. A radial basis function (RBF) network was able to discriminate between the six eye bacteria species, even in the lowest state of concentration, with 92.8% accuracy. These results show the potential application of the Cyranose together with neural network-based predictors, for rapid screening and early detection of bacteria associated with these medical conditions, and the possible development of this EN system as a near-patient tool in primary medical healthcare.     

Determinants of reoperation after 960 valve replacements with Carpentier-Edwards prostheses

During the period of 1977 to 1990, 960 Carpentier-Edwards standard prostheses (Baxter Healthcare Corp., Santa Ana, Calif.) were placed in 875 operations. Freedom from reoperation at 10 years was 57% +/- 4%, 76% +/- 3%, and 95% +/- 5% for mitral, aortic, and tricuspid valve replacement, respectively. Age was the only independent determinant of reoperation for both aortic and mitral valves. Likelihood of reoperation decreased with age, with freedom from reoperation after 10 years in patients aged less than 60 years versus 60 or more years being 65% +/- 5% versus 90% +/- 4% after aortic valve replacement and 48% +/- 5% versus 75% +/- 6% after mitral valve replacement. For mitral valve replacement, larger valve size made reoperation more likely, with freedom from reoperation at 10 years being 71% +/- 6% for sizes median less than 31 mm and 57% +/- 5% for sizes 31 mm or larger. For aortic valve replacement, prior median sternotomy reduced freedom from reoperation at 10 years from 80% +/- 3% to 25% +/- 5%. The low prevalence of reoperation affirms the suitability of the Carpentier-Edwards prosthesis for selected elderly patients and for tricuspid valve replacement. Because of their influence on the probability of reoperation, valve size and prior cardiac procedures also merit consideration in the choice of valvular prosthesis.     

QSAR's from similarity matrices. Technique validation and application in the comparison of different similarity evaluation methods

It has recently been shown that good quantitative structure-activity relationships can be obtained through statistical analysis of molecular similarity matrices. Here we extend the technique to seven additional molecular series, previously studied using Comparative Molecular Field Analysis (CoMFA) methodology. The results are used to confirm technique applicability across a wider range of QSAR problems and to compare quantitatively the ability of various similarity indices to describe biological systems. The relative merits of this technique in comparison to CoMFA are discussed.     

Discrimination of epidemic and sporadic isolates of Arcobacter butzleri by polymerase chain reaction-mediated DNA fingerprinting

DNA polymorphisms of Arcobacter butzleri outbreak-related strains and Arcobacter reference strains were determined by use of the polymerase chain reaction with primers aimed at repetitive sequences. The epidemiological relationship among 14 outbreak-related strains was substantiated, as they showed virtually no genomic variations. Their DNA amplification patterns were, however, clearly different from those of all Arcobacter reference strains studied; each reference strain was characterized by a unique DNA fingerprint.     

Layered crystal thin films

A rigid peripheral clamp with an annular heater is used to bond layered crystals to grids with a thermoplastic adhesive. The layered crystals are subsequently cleaved with adhesive tape while bonded to the grid. The final layered crystal thin film covering a grid opening is exposed only to room air and is free from adhesive or fluid contamination. The results of preparation of several layered crystals, including muscovite mica, molybdenite, and talc, are described.     

Reference Services for Distant Students With Disabilities

Abstract

This introduction discusses the nature and history of the Eastern New York Chapter of the Association of College and Research Libraries (ENY/ACRL). It also defines the content and scope of the Internet-related papers presented at the Spring 1995 ENY/ACRL Conference.