Cross-resistance and resistance longevity as induced by bean leaf beetle, Cerotoma trifurcata and soybean looper, Pseudoplusia includens herbivory on soybean.

Cross-resistance, and longevity of resistance, induced by the bean leaf beetle, Cerotoma trifurcata, was studied IN the soybean PI 227687 that exhibited induced response in earlier studies. Bean leaf beetle adults and soybean looper, Pseudoplusia includens, larvae were used to induce resistance and to determine beetle feeding preference. Beetles were collected from soybean fields 2 to 5 days prior to the feeding preference test. The level of cross-resistance induced by soybean looper herbivory to subsequent bean leaf beetle feeding was higher when compared to cross-resistance induced by bean leaf beetle herbivory against subsequent feeding by soybean looper. Further, herbivory by the bean leaf beetle also induced resistance against soybean looper feeding. In the longevity study, leaflets from treated plants were collected 5, 10, 12, 14, 16, 20 and 25 days after initiation of feeding. Pairwise comparisons of leaflets from plants treated by bean leaf beetle herbivory with untreated plants revealed that induced responses were highest 14 and lowest 25 days after initiation of feeding. On other sampling days, levels of induced response varied with the sampling day.

Sensitivity of FRDA lymphoblasts to salts of transition metal ions.

Friedreich's ataxia (FRDA) is an autosomal recessive neurodegenerative disease resulting from decreased expression of the nuclear-encoded mitochondrial protein, frataxin. FRDA patients have characteristic iron deposits and dysfunction of mitochondrial enzymes in the heart. Inactivation of the frataxin homologue in yeast causes dysregulation of both mitochondrial iron levels and iron export. Previously, we have observed sensitivity of FRDA fibroblasts to FeCl3 and hydrogen peroxide, results consistent with the hypothesis that FRDA cells may experience increased Fenton chemistry. To determine whether the sensitivity of FRDA cells to transition metal ions is a general or specific property, we have compared the sensitivity of lymphoblasts from FRDA patients and healthy controls to the transition metal salts CoCl2, CuSO4 FeCl3 FeSO4, MnCl2, and ZnCl2. FRDA lymphoblasts were significantly more sensitive to FeCl3 and MnCl2 than control cells. However, there were no significant differences observed in sensitivity to CoCl2, CuSO4, FeSO4 and ZnCl2 in the concentration ranges studied. Thus, the sensitivity of FRDA lymphoblasts exposed to transition metals appears to be specific, and could be relevant to the pathophysiological mechanism, which is discussed.

Inhibitory processes and spoken word recognition in young and older adults: the interaction of lexical competition and semantic context.

Two experiments were conducted to examine the importance of inhibitory abilities and semantic context to spoken word recognition in older and young adults. In Experiment 1, identification scores were obtained in 3 contexts: single words, low-predictability sentences, and high-predictability sentences. Additionally, identification performance was examined as a function of neighborhood density (number of items phonetically similar to a target word). Older adults had greater difficulty than young adults recognizing words with many neighbors (hard words). However, older adults also exhibited greater benefits as a result of adding contextual information. Individual differences in inhibitory abilities contributed significantly to recognition performance for lexically hard words but not for lexically easy words. The roles of inhibitory abilities and linguistic knowledge in explaining age-related impairments in spoken word recognition are discussed.

Antibody to hepatitis C virus increases with time on hemodialysis.

We studied whether chronic hemodialysis is associated with an increased risk of exposure to hepatitis C virus. Utilizing a first generation Elisa assay (C-100 Elisa, Ortho Diagnostic Systems, Raritan, NJ) and the Chiron RIBA HCV second generation assay (RIBA, Chiron, Emeryville, CA and Ortho Diagnostic Systems, Raritan, NJ), antibody to HCV was found in 31 of 87 hemodialysis patients (36%). Patients on hemodialysis less than 2 years had an antibody incidence of 15% (n = 46), as contrasted with a 59% incidence for patients on dialysis greater than or equal to 2 years (n = 41). We were unable to demonstrate a correlation of HCV-antibody positivity with history of blood transfusion. The overall incidence is higher than previously reported for hemodialysis patients in the United States. The very high incidence found in patients on dialysis greater than or equal to 2 years suggests that factors in the hemodialysis unit might contribute to the spread of virus.

Antigen-binding activity of antibodies immobilized on styrene copolymer beads.

An important element of the Kodak thin-film immunoassay is antibody immobilized on small polymer beads. Monodisperse styrene copolymer beads offer a well-defined, high surface area substrate for covalent immobilization of monoclonal antibodies. The authors have used the ability of an immobilized monoclonal antibody directed against phenobarbitol, Phe 1.9, to recognize an antigen-enzyme conjugate to determine the extent of antibody activity retention and find that the packing density of antibody at the surface and the copolymer composition are important variables. For polystyrene homopolymer and some copolymers, antibody retention is greater as the packing density at the surface increases. Small changes in the copolymer composition, such as addition of 1% acrylamide or 10% acrylic acid, significantly increase the retention of binding activity of the antibody. The chemistry for covalent coupling of the antibody to the surface is also important. Phe 1.9 coupled to chloromethyl styrene copolymer beads retains less activity than when coupled to vinyl sulfone copolymer beads. Monodisperse sytrene copolymer beads provide great flexibility in the design of rapid immunoassays since a copolymer bead can be tailored to the specific requirements of the antibody and the analyte.

Association between appropriateness of prescribing and prescription documentation.

The association between the quality of physician prescribing and the degree of prescription documentation in the medical record was studied in four family-practice offices. Carbon-copy prescriptions were collected for five months at each office, and 438 were randomly selected for evaluation. For each prescription, a case abstract was prepared from the medical record. The abstract summarized the patient's previous care related to the problem for which the prescription was issued. The abstracts were blinded and randomly assigned for review by a panel of physicians and pharmacists working in family practice, resulting in a total of 1866 evaluations. Each panelist evaluated appropriateness of drug choice, potential benefit, and degree of prescription documentation. Actual prescription documentation of drug name, strength, quantity, directions, and refills was determined by comparing the carbon-copy prescription with the medical record. Multiple regression analysis revealed a significant correlation between panel evaluations for drug choice and actual documentation of drug name, strength, and directions. Likewise, the mean rating of potential benefit was significantly associated with actual documentation of drug name, strength, directions, and refills. The mean rating of appropriateness of documentation was significantly associated with all five independent documentation variables. Drug name, strength, and directions were recorded in 94%, 60%, and 75% of the medical records, respectively. These data demonstrate a positive association between the quality of prescribing and actual prescription documentation in the medical record.