bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Ninety‐Seven Polymorphic Microsatellite Markers for Rainbow Trout
Authors: Rexroad C. E. , Palti Y.
Published: June 2004

A high‐density microsatellite genetic map for rainbow trout Oncorhynchus mykiss is needed for the identification of quantitative trait loci affecting traits of economic interest to the aquaculture industry. These markers are also useful for evolutionary and population genetic studies. The candidate marker sequences that are identifed must be characterized with respect to their uniqueness, polymorphism, heterozygosity, ploidy, and usefulness as comparative mapping markers within the family Salmonidae. Ninety‐seven microsatellite markers were developed and characterized in this study. Twenty‐eight of these markers have been identified as duplicated in the rainbow trout genome based on the observation of more than one allele in at least one homozygous individual from clonal (doubled haploid) lines and more than two alleles in diploid fish. All of the 69 single‐copy markers were polymorphic in the rainbow trout sampled, with an average heterozygosity of 58%.
Decline of the Razorback Sucker in Lake Mohave, Colorado River, Arizona and Nevada
Authors: Marsh Paul C. , Pacey Carol A. , Kesner Brian R.
Published: June 2004

The razorback sucker Xyrauchen texanus is an endangered fish endemic to the Colorado River basin in the western United States. Once widely distributed and common throughout the basin, the species has been eliminated from most of its former range by establishment of nonnative fishes and water development, and remaining numbers have dwindled precipitously from historical levels. Although Lake Mohave, Arizona and Nevada, supports the largest and genetically most diverse remaining population, razorback sucker abundance in the lake plummeted from historical numbers in the hundreds of thousands to only 44,000 in 1991 and fewer than 3,000 in 2001. This population is limited primarily to large, old adults because predation on their larvae by nonnative fishes has precluded measurable recruitment for nearly half a century. At the current rate of decline, extirpation is anticipated within this decade because, at this time, there is no practicable method to remove the continuing threat of nonnative predators to razorback sucker larvae. As such, the persistence of razorback suckers in Lake Mohave depends on a repatriation program begun in 1991, which uses wild‐produced larvae that are reared in captivity and returned to the lake at a size that is less susceptible to predation.
Behavioral Thermoregulation of Brook and Rainbow Trout: Comparison of Summer Habitat Use in an Adirondack River, New York
Authors: Baird Owen E. , Krueger Charles C.
Published: June 2004

The body temperatures of 15 hatchery‐origin and two wild brook trout Salvelinus fontinalis and 11 hatchery‐origin rainbow trout Oncorhynchus mykiss were monitored with internally implanted, temperature‐sensitive radio transmitters from June through September 1997 in a fifth‐order Adirondack river (New York). The fish were released into a 12‐km reach that during summer had maximum temperatures near those that are lethal for salmonids. Body temperatures were compared between species and with river temperatures. In 1997, the maximum river temperature was 26.4°C, and the highest average daily temperature was 25.0°C. The brook trout were usually cooler than the main river flow because they used two of five tributary confluences or groundwater discharge areas in two pools within the main river. The temperatures of the brook trout from June through September were an average of 2.3°C cooler than the main flow of the river and differed significantly (P = 0.002) from those of the rainbow trout, which were 1.5°C cooler than the river. When the river temperatures were 20°C or higher, the mean temperatures of the brook trout were 4.0°C cooler than the river and differed significantly (P = 0.002) from those of the rainbow trout, which were 2.3°C cooler than the river. Brook trout, and to a lesser extent rainbow trout, used localized coolwater areas to lower their body temperatures below that of the main river. Groundwater discharge areas within pools and some tributary confluences were critical habitats for behavioral thermoregulation because they provided refuge areas from warm river water during the summer.
Patterns of Diet and Growth in Co‐occurring Populations of Largemouth Bass and Smallmouth Bass
Authors: Olson Mark H. , Young Brian P.
Published: June 2004

Largemouth bass Micropterus salmoides and smallmouth bass M. dolomieu both undergo ontogenetic diet shifts from insects and zooplankton (as juveniles) to fish and crayfish (as adults). This diet similarity leads to the expectation that the growth rates of co‐occurring largemouth bass and smallmouth bass should covary positively. However, the relative abundance of the two species varies widely among lakes, suggesting that there are important ecological differences and making it difficult to predict how the individual growth rates of the two species will covary among systems. We quantified the diets and growth rates of largemouth bass and smallmouth bass in a set of lakes in New York State that varied in the relative abundance of the two species. Despite changing diets as a function of size, largemouth bass and smallmouth bass consumed similar prey across the size range. As expected based on diets, the growth rates of the two species were also positively correlated among lakes for most size‐classes. However, the growth rates of small, invertebrate‐feeding fish were negatively correlated with those of larger fish that fed on fish and crayfish. These results suggest that largemouth bass and smallmouth bass growth rates respond similarly across environmental gradients but that both species are composed of ecologically distinct stages.
Temperature during Incubation as One Factor Affecting the Distribution of Snake River Fall Chinook Salmon Spawning Areas
Authors: Connor William P. , Piston Charles E. , Garcia Aaron P.
Published: June 2004

Spawning areas of ocean‐type fall Chinook salmon Oncorhynchus tshawytscha in the Pacific Northwest are largely restricted to relatively warm coastal rivers. Fall Chinook salmon spawners in the Snake River basin clearly favor the main‐stem Snake River and the relatively warm lower reaches of its tributaries. In this note, we describe how mean temperature during incubation affects fry emergence date and influences the distribution of fall Chinook salmon spawning areas in the Snake River basin. Using laboratory results and field data, we estimated fry emergence dates for three brood years of fish in seven areas that are consistently used by spawners and in five areas that are rarely used by spawners. Mean incubation temperature was significantly (P < 0.0001) higher in consistently used areas (5.6 ± 0.1°C) than in rarely used areas (4.5 ± 0.1°C). The mean estimated emergence date for the consistently used areas was 12 May (± 20 d), compared with 26 June (± 20 d) for rarely used areas. A logistic discriminant rule fitted from the mean incubation temperatures of the 12 areas discriminated between consistently and rarely used areas with 97% accuracy. We conclude that temperature is one factor that influences the distribution of fall Chinook salmon spawning areas in the Snake River basin.
Relations between Physical Habitat and American Eel Abundance in Five River Basins in Maryland
Authors: Wiley Derek J. , Morgan Raymond P. , Hilderbrand Robert H. , Raesly Richard L. , Shumway Durland L.
Published: June 2004

Although the American eel Anguilla rostrata occurs in a variety of habitats over large geographic areas, little is known regarding the specific habitat relations that regulate eel distribution and abundance in freshwater streams. We evaluated the importance of 17 physical habitat, chemical, and biological variables in predicting eel density in five major river basins in Maryland. Because artificial structures impede eel migration in all five basins, only sites determined to be on unblocked streams or downstream of structures that significantly restrict eel passage were used in the analysis. Stepwise regression identified a model consisting of four variables—velocity–depth diversity, the log‐transformed distance (km) to the Chesapeake Bay, the log‐transformed density of noneel fishes, and the distance to a semipassable or impassable structure—as the best predictor of eel densities. When applied to a random subset of data not used for model development, the model correctly predicted 44.4% of eel densities and had a high mean prediction error (1.86 eels/75 m2) compared with the mean eel density for all sites included in model development (3.33 eels/75 m2). However, the Pearson correlation coefficient between the observed and predicted eel densities (r = 0.64; P < 0.05) indicated that the model was generally successful in predicting trends in observed densities. The study results are consistent with previous research suggesting the lack of significant eel–stream habitat associations, although the presence of a variety of velocity–depth regimes may support higher eel densities. Higher eel densities near artificial structures known to affect upstream movement suggest that eels are accumulating downstream of these structures because of impeded migration.
Genetic Variation and Relatedness of Juvenile Red Snapper Sampled from Shrimp Trawls in the Northern Gulf of Mexico
Authors: Saillant Eric , Mousseau Timothy A. , Gold John R.
Published: June 2004

We studied genetic variation and genetic relatedness among young‐of‐the‐year (age‐0) Gulf of Mexico red snapper Lutjanus campechanus sampled as bycatch in two separate shrimp trawl tows offshore of Galveston, Texas, and in a reference (control) group composed of multiple samples from within the same geographic area. Allelic and haplotypic variation was assayed at 11 microsatellite loci and mitochondrial DNA, respectively. Samples taken as bycatch from shrimp trawls did not differ from the reference group in allele richness, gene diversity, or allele frequency, indicating that most of the genetic variability within the cohort studied was attributable to fish sampled during single, localized tows of the shrimp trawler. Estimates of the variance of pairwise relatedness in the reference sample and in one of the bycatch samples were zero, whereas in the other bycatch sample the variance estimate was 0.001 (P = 0.1). A positive variance suggests that this sample contained individuals that were more closely related genetically than would be expected by chance alone. Because the relatedness estimators are sensitive to sample size, the number of loci, and allele distributions, further studies employing larger sample sizes and additional loci are warranted.
Combining Telemetry and Fisheries Tagging Models to Estimate Fishing and Natural Mortality Rates
Authors: Pollock Kenneth H. , Jiang Honghua , Hightower Joseph E.
Published: June 2004

The traditional multiple‐year tag return method is a fundamental approach to estimating fishing and natural mortality rates in fisheries. It can provide reliable and precise estimation of the parameters when the tag reporting rate, λ, is known. However, it is often difficult to estimate λ accurately. An additional disadvantage is that this method has to estimate natural mortality indirectly because natural deaths are not observable. Recently, fisheries biologists have begun to implement telemetry methods to estimate fishing and natural mortality. The advantage of a telemetry method is that it contains direct information about natural mortality and survival. A shortcoming is that there is no direct information on fishing deaths. In this paper, we combine the two methods, using direct information about both fishing and natural mortality to obtain more precise and effectively unbiased parameter estimates, including reporting rate estimates for the regular tags. Using simulation when the telemetry tag relocation probability equals 1, we found that the relative standard error (RSE) of natural mortality estimates in the combination method is much improved relative to those of the tag return and telemetry methods. Annual fishing mortality estimates can also be estimated precisely. As expected, as the relocation probability of telemetry tags decreases the RSE of natural mortality and the other parameter estimates increases, but only slightly. Studies clearly should have relocation probabilities that are as high as possible. The tag reporting rate estimates are typically precisely estimated in the combined model. This is very important, as the tag reporting rate is not easy to estimate with other methods.
Effects of Freshwater and Marine Growth Rates on Early Maturity in Male Coho and Chinook Salmon
Authors: Vøllestad Leif Asbjørn , Peterson Jeramie , Quinn Thomas P.
Published: June 2004

In many populations of salmonid fishes, a fraction of the males mature at a younger age than the females; these males are termed jacks if they have migrated to sea and precocious parr if they matured in freshwater. We examined detailed data on the University of Washington hatchery populations of coho salmon Oncorhynchus kisutch and Chinook salmon O. tshawytscha for more than 30 years to test whether rapid growth in freshwater or at sea increases the probability of early maturity in males. The average size of Chinook salmon smolts (2.6–20.9 g) increased over the years in question. The proportion of males maturing as jacks increased with smolt size but not with the potential for growth at sea. The size of the smolts (but not growth potential at sea) was positively correlated with the proportion of the jacks maturing after only one summer at sea (so‐called minijacks) rather than two summers. In coho salmon, average smolt size (6.1–22.4 g) did not vary consistently with time. There was a slight tendency for cohorts with larger smolts to produce more jacks, but marine growth potential was negatively related to the proportion of jacks. For neither species did marine environmental variables influence the proportion of jacks. Taken together, these results support the hypothesis that size prior to seawater entry has the predominate effect on the probability of early maturation and that the growth potential at sea has a neutral or even inhibitory effect on early maturity.
Marine Subsidies in Freshwater: Effects of Salmon Carcasses on Lipid Class and Fatty Acid Composition of Juvenile Coho Salmon
Authors: Heintz Ron A. , Nelson Bonita D. , Hudson John , Larsen Marie , Holland Larry , Wipfli Mark
Published: June 2004

Returning adult salmon represent an important source of energy, nutrients, and biochemicals to their natal streams and may therefore have a quantitative effect on the energy levels of stream‐resident salmonids. We tested this hypothesis by constructing simulated streams for coho salmon Oncorhynchus kisutch to which we added 0, 1, and 4 carcasses/m2 (0, 0.71, and 2.85 kg wet mass/m2) of pink salmon O. gorbuscha. After 60 d we evaluated the lipid class and fatty acid composition of rearing coho salmon from the simulated streams; the lipid content and triacylglycerols of the coho salmon increased with increasing carcass density whereas phospholipids decreased. Increased amounts of triacylglycerols accounted for most of the lipid increase. In addition to increasing in concentration, the fatty acid composition of the triacylglycerols also changed with carcass density. Triacylglycerols of juvenile coho salmon from the control streams had significantly higher omega‐3 : omega‐6 ratios as a result of fivefold and sixfold increases in the concentrations of eicosapentanoic and docosahexanoic fatty acids, respectively. These data demonstrate an immediate nutritional benefit resulting from the introduction of salmon carcasses in juvenile coho salmon rearing habitat and indicate the utility of fatty acid and lipid class analysis for examining the effects of marine‐derived nutrients on juvenile salmonids.
Comparison of Alewife Young‐of‐the‐Year and Adult Respiration and Swimming Speed Bioenergetics Model Parameters: Implications of Extrapolation
Authors: Klumb Robert A. , Rudstam Lars G. , Mills Edward L.
Published: June 2004

Parameters derived from laboratory experiments that separately measured the routine metabolic rates (respiration) and swimming speeds of young‐of‐the‐year (age‐0) alewives Alosa pseudoharengus were compared with values published for a bioenergetics model for adults. Respiration rates of age‐0 alewives were significantly influenced by water temperature and scaled isometrically with weight (range, 0.0001–1 g). Swimming speed was strongly related to fish weight and, unlike for adult alewives, water temperature significantly influenced the swimming speeds of age‐0 fish. Temperature coefficients, along with the slopes for the weight dependence of age‐0 alewife respiration rates and swimming speeds, significantly differed by 51–709% from published parameters for adults. Using adult parameters, the standard respiration rates at 15–25°C of age‐0 alewives weighing less than 0.02 g were overestimated by 7–88% and the swimming speeds for fish weighing less than 1.0 g were overestimated by 130–4,270%. Application of our age‐0 alewife swimming speed parameters in the exponential activity function used in the adult bioenergetics model resulted in no activity costs for age‐0 fish smaller than 0.2 g, which is clearly unrealistic. Because no data relating respiration to activity level (i.e., concurrent measurements of respiration and swimming speed) currently exist for age‐0 alewives, we recommend using routine respiration rates without an activity multiplier to represent the costs of normal activity in the field. All parameters derived in this study for age‐0 alewives differed from those of adults by more than 10%, a deviation commonly used in sensitivity analyses of bioenergetics models, which indicated that application of adult parameters to early life stages was not warranted. Use of metabolism–weight relations from the literature derived for multiple species also are not recommended because the estimated routine metabolic rates of age‐0 alewives differed by 2–311% from rates measured in this study.
Fish Size and Prey Availability Affect Growth, Survival, Prey Selection, and Foraging Behavior of Larval Yellow Perch
Authors: Graeb Brian D. S. , Dettmers John M. , Wahl David H. , Cáceres Carla E.
Published: June 2004

Zooplankton availability is strongly linked with the growth, survival, and ultimately recruitment of fish during their early life history. We examined how different types of zooplankton affected the growth, survival, and prey selection of larval yellow perch Perca flavescens in a series of laboratory experiments. The growth and survival of newly hatched (5–7‐mm) to 12‐mm yellow perch larvae was greatest when feeding on adult copepods and copepod nauplii. The growth and survival of yellow perch larvae longer than 12 mm was greatest when feeding on adult copepods and small cladocerans. Prey selection patterns closely followed trends in growth and survival; smaller larvae positively selected adult and naupliar copepods, whereas larger larvae selected adult copepods and small cladocerans. Foraging behavior experiments conducted with larvae longer than 12 mm revealed that these fish derived similar energetic gains when feeding solely on adult copepods and small cladocerans. The pathway to this energetic benefit differed substantially between prey types. Adult copepods yielded substantial energy to larval yellow perch because of the minimal handling time involved, despite the lower capture efficiency than with cladocerans. Conversely, yellow perch larvae realized high energetic gain from small cladocerans because of high capture efficiency, despite the higher handling times than with adult copepods. These results illustrate the importance of experimentally quantifying the feeding behavior of fish larvae to gain insight into how larval fish behavior and food type interact to shape larval fish growth patterns.
Distribution, Growth, and Feeding of Sockeye Salmon in the Western Bering Sea
Authors: Radchenko Vladimir I. , Mathisen Ole A.
Published: June 2004

The Pacific Research Institute of Fisheries and Oceanography (TINRO) in Vladivostok, Russia, conducted 12 major biological surveys in the western Bering Sea in 1986–1995. During these surveys, sockeye salmon Oncorhynchus nerka were sampled with a new pelagic trawl. We used salmon catch, age and growth, and diet data from the TINRO surveys to evaluate the role of sockeye salmon in the structure and function of pelagic communities in the western Bering Sea. Estimates of abundance (numbers and biomass) showed large annual and seasonal fluctuations in the western Bering Sea. Immature and maturing sockeye salmon migrated to the western Bering Sea in late spring from their winter (December–May) feeding grounds in the North Pacific Ocean. Maturing sockeye salmon were distributed in the western Bering Sea from June to early August before returning to their natal spawning rivers. In late August, smolts (age n.0, where the n indicates an ocean‐age cohort and zero indicates the number of ocean annuli) began to move from coastal to offshore waters, where the largest numbers occurred in September–November. We inferred from catch data that most of the other age‐groups of sockeye salmon left the western Bering Sea by the end of November and moved southward to the North Pacific Ocean. The analyses indicated that sockeye salmon fed in the seasonal thermocline layers, where they were important consumers of interzonal zooplankton and micronektonic organisms. The dietary ration of sockeye salmon was high. The high growth rates of sockeye salmon in the western Bering Sea were comparable to those in the North Pacific Ocean. The wide distribution, numerous trophic linkages, high rations, and high growth rate of sockeye salmon establish their important role in pelagic communities of the western Bering Sea.
A Model‐Based Assessment of the Potential Response of Snake River Spring–Summer Chinook Salmon to Habitat Improvements
Authors: McHugh Peter , Budy Phaedra , Schaller Howard
Published: June 2004

The current recovery strategy for threatened Snake River Chinook salmon Oncorhynchus tshawytscha relies heavily on improvements to the quality of freshwater spawning and rearing habitat; however, the potential survival benefit from these actions is unknown. To address this issue, we created a model for predicting the early freshwater survival rates (egg to smolt) of this species as a function of five easily measured physical habitat variables and used this model to evaluate survival rates under five alternative future habitat states. Model validation showed that the predictions were reasonably accurate for individual stocks as well as for the trend in predictions across stocks. The results for the future habitat scenarios suggest that the potential for improving survival rates through habitat restoration is high for a few populations and low to nonexistent for most others while the potential for reduction in survival rates due to reduced habitat quality is great for all populations. The effects of modeled egg‐to‐smolt survival rate changes should be evaluated across the entire Chinook salmon life cycle to assess recovery potential.
Effect of Temperature on the Identification of Larval Black Crappies, White Crappies, and F1 Hybrid Crappies
Authors: Spier Timothy W. , Ackerson Jonathan R.
Published: June 2004

Myomere counts have been used to differentiate larval black crappies Pomoxis nigromaculatus and white crappies P. annularis; however, both hybridization and water temperatures during egg development can influence myomere numbers and thereby interfere with identification of larval crappies. We artificially produced pure black crappies, white crappies, and their F1 hybrids and allowed them to develop at different temperatures. We then compared counts of preanal, postanal, and total myomeres among taxa and water temperatures. Although white crappies had significantly more preanal myomeres and significantly fewer postanal myomeres than the black crappies or the F1 hybrids, counts of these myomeres overlapped too much to be useful for identification purposes. Some of the overlap of myomere numbers was caused by variation due to natal water temperature differences. Higher temperatures caused the anus to develop more posteriorly in larval crappie, influencing the number of preanal and postanal myomeres. Because myomere counts overlap so much and because hybridization and natal water temperature can induce variation in myomere numbers, myomere counts are not useful for discriminating between the two species of Pomoxis.
Consequences of Vegetation Density and Prey Species on Spotted Gar Foraging
Authors: Ostrand Kenneth G. , Braeutigam Ben J. , Wahl David H.
Published: June 2004

Adult spotted gar Lepisosteus oculatus are potentially important components of food webs given their predatory habits and high relative abundance. However, few studies have examined their foraging behavior. Therefore, we examined the effects of vegetation density on the foraging success of adult spotted gars preying on bluegill Lepomis macrochirus and fathead minnow Pimephales promelas. Spotted gars use ambush foraging and were more successful capturing fathead minnow than bluegills at all stem densities. Predation success was negatively correlated with stem density for bluegill prey but not for fathead minnow. Although fathead minnow and bluegills shoaled less as stem density increased, bluegills modified their behavior in the presence of a predator by moving lower in the water column at high stem densities, whereas fathead minnow did not. Predatory behaviors were directed at prey within a short distance and near the surface of the water. Foraging of spotted gar, a lie‐in‐wait predator, was primarily influenced by prey behavior, with the amount of vegetative cover playing a secondary role that also varies with prey species.
Factors Associated with the Risk of Liver Enzyme Elevation in Patients with Type 2 Diabetes Treated with a Thiazolidinedione
Authors: St. Peter John V. , Neafus Kristin L. , Khan Mehmood A. , Vessey John T. , Lockheart Michael S. K.
Published: June 2004

Study Objective. To characterize frequency of liver enzyme elevation in patients with type 2 diabetes mellitus receiving troglitazone.

Design. Retrospective study.

Setting. Hospital‐affiliated medical center.

Patients. Two hundred ninety‐one patients with type 2 diabetes mellitus.

Intervention. Data from patients with an average troglitazone exposure of 412.7 ± 255.6 days were studied.

Measurements and Main Results. Enzyme elevations more than 1.5 times the upper limit of normal (ULN) occurred in 17 patients (5.8%) and more than 3‐fold elevations in 6 (2.1%). The relationship among enzyme elevation events, demographic factors, duration of troglitazone exposure, frequency of monitoring, and concurrent drugs (limited to glucose and lipid‐lowering agents) was assessed by multiple logistic regression. Age was an independent predictor of risk (p=0.009), and concurrent insulin therapy approached statistical significance (p=0.051) for 1.5‐fold ULN elevation in liver enzymes. Age and concurrent therapy with 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase inhibitors were the only significant predictors of 3‐fold ULN elevations (p=0.03 and p=0.04, respectively).

Conclusion. Several factors appear to increase the risk of enzyme elevation events in patients treated with troglitazone.
Phenylacetate Pharmacokinetics Based on Iterative Two‐Stage Population Analysis
Authors: Burstein Aaron H. , Reed Eddie , Tompkins Anne C. , Venzon David , Figg William D.
Published: June 2004

Study Objective. To determine the population pharmacokinetics of phenylacetate using iterative two‐stage analysis implemented with ADAPT II software.

Setting. United States government research hospital.

Design. Retrospective pharmacokinetic analysis.

Subjects. Sixty‐seven patients with refractory solid tumors.

Intervention. Subjects received from 1–10 courses/individual (total 141 courses) of therapy with either twice‐daily administration or continuous infusions of phenylacetate.

Measurements and Main Results. Extensive plasma concentration measurements were performed after the initial dose or start of infusion, with sparse sampling during subsequent courses of therapy. Phenylacetate plasma concentration‐time profiles were described by a one‐compartment, capacity‐limited clearance model with incorporation of parameters to describe extent of induction of clearance and the rate of induction. Median estimates for volume of distribution, maximum rate of drug elimination, Michaelis‐Menten constant, and induction factor, and rate of onset of induction of drug clearance were 0.33 (0.26, 0.48) L/kg, 21.8 (16.3, 28.0) mg/kg/hour, 94.6 (48.8, 153.0) mg/L, 1.28 (1.06, 1.66), and 0.0038 (0.0019, 0.0058) hour−1, respectively.

Conclusion. The results of this study are similar to previous pharmacokinetic evaluations using the Abbottbase PKS system but suggest that earlier analyses were suboptimal.
Evaluation of Very Low‐Dose Subcutaneous Vitamin K During Postoperative Warfarin Therapy
Authors: Possidente Carl J. , Howe James G. , Cushman Mary
Published: June 2004

Study Objective. To determine the effect of very low‐dose subcutaneous vitamin K (SCVK) compared with withholding warfarin for above‐target international normalized ratio (INR) values after joint surgery.

Design. Historical controlled study.

Setting. University hospital.

Subjects. One hundred thirty‐nine patients beginning warfarin after total joint surgery.

Intervention. For a high INR, warfarin was either withheld or SCVK 100, 300, or 400 μg was administered, depending on INR value.

Measurements and Main Results. The primary outcome was change in INR from the day of intervention (day 1) to the next day (day 2). Adjusting for day 1 INR, the mean day 2 INR was 2.10 (95% confidence interval [CI] 1.86–2.33) after SCVK, compared with 2.73 (95% CI 2.50–2.96) in controls. This corresponded to declines of −0.72 and −0.08, respectively (p=0.001).

Conclusion. In orthopedic patients starting warfarin therapy, very low‐dose SCVK was more effective than withholding warfarin in reducing high INRs. Investigations in other populations and assessment of the effect of low‐dose SCVK on postoperative bleeding are indicated.
Evaluation of the Ability of Seven Herbal Resources to Answer Questions About Herbal Products Asked in Drug Information Centers
Authors: Walker J. Bryan
Published: June 2004

Study Objective.To evaluate the ability of seven widely known herbal references and electronic databases to answer questions about herbal products asked at drug information centers.

Design.Cross‐sectional study.

Setting.Five academic and institutional drug information centers.

Methods.Fifty‐seven herbal‐related questions were obtained from academic and institutional drug information centers. Seven herbal references and electronic databases were evaluated for their ability to answer these 57 questions:The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines, 1st edition; Physicians' Desk Reference (PDR) for Herbal Medicines, 2001 edition; Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies, 4th edition; The Lawrence Review of Natural Products, 2001; Natural Medicines Comprehensive Database (electronically updated, 2001); The Natural Pharmacist (electronically updated, 2001); and AltMedDex (electronically updated, 2001).

Results.Natural Medicines Comprehensive Database outperformed all other products evaluated, providing direct answers to 61% of questions. AltMedDex and The Natural Pharmacist performed similarly to one another, answering 49% and 44% of questions, respectively.The Lawrence Review of Natural Products, PDR for Herbal Medicines, The Complete German Commission E Monographs, andTyler's Honest Herbal were the least helpful in providing direct answers to the questions (24%, 21%, 11%, and 9%, respectively).

Conclusion.Natural Medicines Comprehensive Database, AltMedDex, and The Natural Pharmacist outperformed all other evaluated herbal references and electronic databases in their ability to answer questions about herbal products posed in clinical practice.
Probable Case of Torsades de Pointes Induced by Fluconazole
Authors: Khazan Minou , Mathis A. Scott
Published: June 2004

A 25‐year‐old woman who was hospitalized for worsening endocarditis had a prolonged QT interval at baseline and developed monomorphic ventricular arrhythmias, which were managed successfully with pacing and antiarrhythmic therapy. Several days later, the patient started receiving high‐dose fluconazole for fungemia and subsequently experienced episodes of torsades de pointes, a polymorphic ventricular arrhythmia associated with a prolonged QT interval or prominent U wave on the electrocardiogram. The arrhythmia developed in the presence of known risk factors. Clinicians should be aware of these risk factors and other relevant structural similarities with drugs that cause torsades de pointes so that they can recognize patients who may be at risk for fluconazole‐associated arrhythmia.
Population Pharmacokinetic Modeling of Pyrazinamide in Children and Adults with Tuberculosis
Authors: Zhu Min , Starke Jeffrey R. , Burman William J. , Steiner Phillip , Stambaugh Jerry Jean , Ashkin David , Bulpitt Amy E. , Berning Shaun E. , Peloquin Charles A.
Published: June 2004

Study Objective. To determine population pharmacokinetic parameters of pyrazinamide after multiple oral doses given to children and adults with tuberculosis.

Design. Prospective, multiple‐dose population pharmacokinetic study.

Setting. Five hospitals in the United States.

Patients. Sixty‐seven adults and 23 children with active tuberculosis.

Intervention. The 90 patients received multiple oral doses of pyrazinamide as part of their treatment, based on the best clinical judgment of the attending physicians and in keeping with standard clinical practices at each institution. The patients also received other antituberculosis drugs empirically or based on in vitro susceptibility data.

Measurements and Main Results. Serum samples were collected over 12 hours after dosing and were assayed with a validated gas chromatography assay with mass selective detection. Concentration‐time data were analyzed by using population methods. Pyrazinamide concentrations increased linearly with increasing oral doses (185–3550 mg). Median maximum serum concentration values were 41.0 μg/ml with daily dosing and 66.1 μg/ml with larger, twice‐weekly dosing. Incomplete (18%) or delayed (30%) absorption was more common in children than in adults (1% for each). Pharmacokinetic parameters of pyrazinamide were independent of human immunodeficiency virus status and patient demographics, except for body weight. Population elimination half‐life values in pediatric and adult patients were 3.5 and 6.0 hours, respectively. Median volume of distribution (L/kg) was 32% larger in children, and median clearance (L/hr/kg) was 106% larger in children, with a resultant median half‐life 43% shorter in children.

Conclusion. Pyrazinamide concentrations and most pharmacokinetic parameters were comparable to those previously published. Apparent half‐life was somewhat shorter than that in previous reports. Compared with adults, absorption of pyrazinamide in children appeared more likely to be incomplete or delayed.
Limited Tolerability of Levofloxacin and Pyrazinamide for Multidrug‐Resistant Tuberculosis Prophylaxis in a Solid Organ Transplant Population
Authors: Lou Huei‐Xin , Shullo Michael A. , McKaveney Teresa P.
Published: June 2004

Study Objective. To determine the long‐term tolerability of prophylactic administration of pyrazinamide and levofloxacin in patients possibly exposed to multidrug‐resistant tuberculosis (MDRTB) after undergoing solid organ transplantation.

Design. Retrospective analysis.

Setting. Community outpatient clinic.

Patients. Forty‐eight recipients of solid organ transplants beginning prophylaxis for MDRTB during August 1999 after possible exposure to a single index case of multidrug‐resistant Mycobacterium tuberculosis within our community.

Intervention. Prophylaxis consisted of pyrazinamide 30 mg/kg/day plus levofloxacin 500 mg/day, administered for 1 year.

Measurements and Main Results. Thirteen (27.1%) of the 48 patients completed therapy; 27 (56.3%) discontinued therapy within 4 months due to adverse drug events. Gastrointestinal intolerance was the major adverse event resulting in early discontinuation.

Conclusion. Prophylaxis of MDRTB with levofloxacin and pyrazinamide was associated with limited tolerability due to the high frequency of adverse events. While we search for a better tolerated prophylactic regimen, close monitoring for adverse reactions is recommended.
Matrix Metalloproteinase Inhibitors: Do They Have a Place in Anticancer Therapy?
Authors: Rudek Michelle A. , Venitz Jürgen , Figg William D.
Published: June 2004

Matrix metalloproteinases (MMPs) are a family of enzymes involved in degradation of extracellular matrix. An imbalance between MMPs and naturally occurring MMP inhibitors may cause excess extracellular matrix destruction, allowing cancer cells to invade surrounding tissues and metastasize, and permitting angiogenesis to occur. Inhibition of certain key MMPs may prevent angiogenesis, tumor growth, invasion, and metastasis. Gelatinases MMP‐2 and MMP‐9 are expressed during carcinogenesis and angiogenesis. Synthetic MMP inhibitors were designed to target these enzymes and potentially prevent the tumor growth and metastases associated with cancer.
Chronic Hepatitis B: Current and Future Treatment Options
Authors: Rivkina Anastasia , Rybalov Sergey
Published: June 2004

Hepatitis B, a major viral infection that can lead to cirrhosis and hepatocellular carcinoma, is the ninth most common cause of death worldwide. Prevention of hepatitis B virus transmission is key to reducing the spread of this serious condition. Management of chronic hepatitis B requires significant knowledge of approved pharmacotherapeutic agents and their limitations. Today, agents approved by the Food and Drug Administration for this infection are interferon‐α‐2b and lamivudine. Newer agents are being developed and hold promise: adefovir, famciclovir, ganciclovir, lobucavir, entecavir, emtricitabine, L‐deoxythymidine, clevudine, a therapeutic vaccine, and thymosin α‐1. Therapeutic options for managing hepatitis infection after liver transplantation are also evolving. These include hepatitis B immunoglobulin and nucleoside analogues.
Clinical Experience of Quinupristin‐Dalfopristin for the Treatment of Antimicrobial‐Resistant Gram‐Positive Infections
Authors: Goff Debra A. , Sierawski Sondra J.
Published: June 2004

Data regarding clinical administration, outcomes, and costs of quinupristin‐dalfopristin treatment in 48 patients with serious gram‐positive infections in a large teaching hospital were analyzed retrospectively. Thirty‐six patients had vancomycin‐resistant Enterococcus faecium (VREF) infections, 10 had methicillin‐resistant Staphylococcus aureus (MRSA) or Staphylococcus epidermidis (MRSE) infections, and 2 were treated empirically. Overall, 67% of the patients were clinically cured, and 56% had bacteriologic eradication; overall response rate was 48%. Patients with VREF bacteremia had the highest clinical cure (82%) and bacteriologic eradication (73%) rates. Mortality rate was 31%, but 6 of 15 patients who died were treated successfully with quinupristin‐dalfopristin. Length of hospital stay was significantly shorter among patients who lived versus those who died (p>0.05). Similarly, the mean hospital cost/patient was significantly lower in patients who lived than in those who died ($35,244 vs $122,922). Quinupristin‐dalfopristin is effective in the treatment of both VREF and MRSA or MRSE infections in patients who fail to respond to, or are intolerant of, vancomycin.
Life‐Threatening Isradipine Poisoning in a Child
Authors: Romano Michael J. , Gaylor Allyson , Sang Charlie J.
Published: June 2004

Calcium channel blockers as a group are responsible for significant morbidity and mortality with toxic exposures. Isradipine, a cardioselective dihydropyridine calcium channel blocker, rarely has been implicated, with only two reports in the literature of significant toxic reactions, one in an adult and another in a child. To our knowledge, we describe the first case of life‐threatening isradipine poisoning in a child and provide documentation of serum drug levels. On arrival at the hospital, a 5‐year‐old girl had abdominal distention and bradycardia that rapidly progressed to asystole. She received 73 minutes of cardiopulmonary resuscitation and transvenous cardiac pacing and survived with an intact neurologic recovery. Serum concentrations of isradipine were 30–100 times those found with therapeutic use.
Transient Pulmonary Infiltrates Possibly Induced by Quinine Sulfate
Authors: Krantz Mori J. , Dart Richard C. , Mehler Philip S.
Published: June 2004

Quinine sulfate, which has been available for many years, has not been implicated definitively in the development of pulmonary toxicity. A variety of adverse effects, however, have been reported with quinine administration. A 45‐year‐old woman with longstanding rheumatoid arthritis experienced wheezing, severe anxiety, breathlessness, cough, orthopnea, mild fever, chills, and pleuritic chest discomfort after taking a single dose of quinine for nocturnal leg cramps. Radiographic imaging demonstrated diffuse, bilateral pulmonary infiltrates suggestive of pulmonary edema. No cause other than acute quinine ingestion could be identified despite thorough cardiac and infectious disease evaluations. Clinicians should be aware of a possible association between quinine sulfate and pulmonary toxicity.
Vancomycin‐Induced Neutropenia in a Patient Positive for an Antineutrophil Antibody
Authors: Schwartz Michael D.
Published: June 2004

A 48‐year‐old man, hospitalized after experiencing subarachnoid hemorrhage secondary to a basilar aneurysm, received vancomycin for methicillin‐resistant Staphylococcus aureus sepsis. He developed neutropenia 16 days after the start of vancomycin therapy, and his white blood cell count decreased to a nadir of 1200 cells/mm3. Vancomycin was discontinued, and granulocyte‐colony stimulating factor (G‐CSF) therapy was begun. The patient was rechallenged with a single dose of vancomycin 1 g in preparation for intraarterial aneurysm coiling. His white blood cell count dropped to 600 cells/mm3 but returned to normal with continued G‐CSF therapy. A diagnosis of vancomycin‐induced neutropenia was considered. Subsequent testing by granulocyte agglutination and granulocyte immunofluorescence assays revealed that his serum was positive for an antigranulocyte antibody. A test for HLA antibody reactivity was negative. Monoclonal antibody immobilization of granulocyte antigens assay failed to determine the antigen specificity of his granulocyte antibody.
Antimicrobial‐Associated Acute Hepatitis
Authors: Nicholson Susan C. , Webb C. Douglas , Moellering Robert C.
Published: June 2004

Recently, the case history of a 44‐year‐old woman who experienced acute hepatitis subsequent to therapy for chronic sinusitis was reviewed. The patient sequentially was administered clarithromycin, levofloxacin, amoxicillin‐clavulanate, and gatifloxacin. Her adverse events were attributed definitively to gatifloxacin, a surprising conclusion because many other possible causes of hepatitis existed in this case. Not ruled out as potential causes of the clinical and laboratory adverse events were hepatitis other than hepatitis A or B. Other antimicrobials administered were dismissed. In particular, extended treatment with amoxicillin‐clavulanate has been clearly linked to hepatotoxic effects that may occur long after therapy begins. Thus, while we agree that physicians must be aware of the potential for antimicrobial hepatotoxicity, we believe that this case study is not a solidly documented case of hepatitis attributable to gatifloxacin and overlooks other possible causes of acute hepatitis of which prescribers should be aware.
ECT studies of the choking phenomenon in a gas–solid circulating fluidized bed
Authors: Du Bing , Warsito W. , Fan Liang‐Shih
Published: June 2004

Choking is commonly defined as a phenomenon where a sudden change in the solids holdup occurs in a gas–solid fluidization system. In this study, the electrical capacitance tomography (ECT) based on the neural network multicriteria optimization image reconstruction technique (NNMOIRT), developed by this research group, is used to probe the mechanism of choking formation by examining a real‐time, quasi‐3D cross‐sectional flow structure of a circulating fluidized bed riser. The particles used are FCC catalysts. The ECT with NN‐MOIRT reveals a double solids‐ring flow structure and the presence of particle blobs at the center of the bed in the circulating fluidized bed (CFB) riser. This flow structure, when it is present at the entrance region of the riser, undergoes a distinct variation during the choking transition when the gas velocity is below the transport velocity Utr, but does not undergo a distinct variation when the gas velocity is above Utr. This flow structure, when it is present at the upper region of the riser, however, does not vary distinctly at any gas velocity. Such flow structure variations are not appreciably affected by the solids feeding patterns with or without a gas or solids distributor, or by the gas humidity. For the low gas velocities (<Utr), the borescope measurement indicates that the solids concentration in the particle blob and the blob size all increase as the solids circulation rate increases. The disintegration of the enlarged blobs or blob jets and the collapse of the solids suspension characterize the mechanics of the initiation of the choking transition to the dense‐phase fluidization regime attributed to solids suspension instability. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1386–1406, 2004
Increased prevalence of unprovoked seizures in patients with a 22q11.2 deletion
Authors: Kao Amy , Mariani Juliana , McDonald‐McGinn Donna M. , Maisenbacher Melissa K. , Brooks‐Kayal Amy R. , Zackai Elaine H. , Lynch David R.
Published: June 2004

Many neurologic abnormalities have been identified in patients with a deletion of chromosome region 22q11.2, including recurrent, apparently unprovoked seizures. We reviewed the database of patients with a 22q11.2 deletion at the Children's Hospital of Philadelphia to assess the prevalence of idiopathic epilepsy in this population. The records of 383 patients with a confirmed 22q11.2 deletion were reviewed for documentation of seizures; precipitating events such as hypocalcemia, fever, and recent surgery; MRI and EEG findings (to aid in seizure classification); and potential risk factors for epilepsy. Of 348 patients with adequately detailed histories, 27 patients had apparently unprovoked seizures (7% of the total population). A disproportionate number of these patients met criteria for generalized epilepsy. Cardiac disease and prematurity were not risk factors for the development of unprovoked seizures in this population. The prevalence of unprovoked seizures in individuals meeting criteria for epilepsy in patients with a 22q11.2 deletion evaluated at our institution is much greater than in the general population. The association with generalized epilepsy suggests that this increased risk is a primary manifestation of the genetic syndrome, not a secondary result of the other manifestations of 22q11.2 deletions. These results suggest that diagnostic screening for the 22q11.2 deletion syndrome should be considered in patients with epilepsy and other signs suggestive of this interstitial deletion syndrome, and have implications for the identification of potential genetic loci for idiopathic epilepsy. © 2004 Wiley‐Liss, Inc.