Search

The anticonvulsant phenytoin causes a decrease in plasma concentrations of folate in epileptic patients. The mechanism underlying this depletion is unknown. To study this mechanism, phenytoin was administered to rats by addition to the diet (3 g phenytoin/kg diet) for up to 8 wk. At selected times during phenytoin administration (0, 3, 7, 10, 14, 28, 42 and 56 d), the composition of the folate pools of intestinal mucosa, liver, bile and brain was determined. The 0-d administration served as the control group. The controls were fed the same diet without phenytoin for the eight weeks of the experiment. Phenytoin administration had minimal effect on either the folate concentration or the composition of the folate pool in intestinal mucosa. Phenytoin administration did, however, cause a depletion of total hepatic folate to about 50% of control, causing the pentaglutamate derivatives of each of the pteridine derivatives to decline rapidly, with the formyl and dihydro derivatives of the pteridine moiety falling more rapidly than the methyl and methylene + tetrahydro derivatives. The monoglutamate of the methylene + unsubstituted tetrahydro derivative increased significantly with time of phenytoin treatment. The mono- and di-glutamate derivatives of the methyltetrahydrofolate increased transiently and significantly in the bile, and the polyglutamate chain length increased significantly in the brain with time of phenytoin treatment. We conclude that phenytoin inhibits the formation of polyglutamyl folates in rat liver.

MB and MR were funded by a grant from the Esmee Fairbairn Foundation, BC by the Rufford Foundation. North American and Mexican species assessments were funded by the Regina Bauer Frankenberg Foundation for Animal Welfare. Species assessments under the Global Reptile Assessment (GRA) initiative are supported by: Moore Family Foundation, Gordon and Betty Moore Foundation, Conservation International, Critical Ecosystem Partnership Fund (CEPF), and European Commission. Additional acknowledgements are included in the online supplementary material. The assessment workshop for Mexican reptiles was kindly hosted by Ricardo Ayala and the station personnel of the Estacion de Biologia Chamela, Institut de Biologia, Universidad Nacional Autonoma de Mexico. Workshop and logistical organisation of the Philippines assessments was provided by the Conservation International Philippines Office, in particular Ruth Grace Rose Ambal, Melizar V. Duya and Oliver Coroza. Workshop and logistical organisation for the European Reptile and Amphibian Assessments was provided by Doga Dernegi, in particular Ozge Balkiz and Ozgur Koc. Workshop and logistical organisation for assessments of sea snakes and homalopsids was provided by the International Sea Turtle Symposium and Dr. Colin Limpus (Australian Government Environmental Protection Agency). Special thanks to Jenny Chapman (EPA) and Chloe Schaub le (ISTS). Thank you also to Dr. Gordon Guymer (Chief Botanist Director of Herbarium) for accommodating us at the Herbarium in the Brisbane Botanical Gardens, and Mark Read and Kirsten Dobbs (Great Barrier Reef Marine Parks Association) and Dave Pollard and Brad Warren (Ocean Watch Australia) for institutional support. Mohamed Bin Zayed Species Conservation Fund, Conservation International Madagascar and the Darwin Initiative contributed to funding the costs of the Madagascar reptile workshop., Effective and targeted conservation action requires detailed information about species, their distribution, systematics and ecology as well as the distribution of threat processes which affect them. Knowledge of reptilian diversity remains surprisingly disparate, and innovative means of gaining rapid insight into the status of reptiles are needed in order to highlight urgent conservation cases and inform environmental policy with appropriate biodiversity information in a timely manner. We present the first ever global analysis of extinction risk in reptiles, based on a random representative sample of 1500 species (16% of all currently known species). To our knowledge, our results provide the first analysis of the global conservation status and distribution patterns of reptiles and the threats affecting them, highlighting conservation priorities and knowledge gaps which need to be addressed urgently to ensure the continued survival of the world’s reptiles. Nearly one in five reptilian species are threatened with extinction, with another one in five species classed as Data Deficient. The proportion of threatened reptile species is highest in freshwater environments, tropical regions and on oceanic islands, while data deficiency was highest in tropical areas, such as Central Africa and Southeast Asia, and among fossorial reptiles. Our results emphasise the need for research attention to be focussed on tropical areas which are experiencing the most dramatic rates of habitat loss, on fossorial reptiles for which there is a chronic lack of data, and on certain taxa such as snakes for which extinction risk may currently be underestimated due to lack of population information. Conservation actions specifically need to mitigate the effects of human-induced habitat loss and harvesting, which are the predominant threats to reptiles., Esmee Fairbairn Foundation, Rufford Foundation, Regina Bauer Frankenberg Foundation for Animal Welfare, Moore Family Foundation, Gordon and Betty Moore Foundation, Conservation International, Critical Ecosystem Partnership Fund (CEPF), European Commission Joint Research Centre, Zayed Species Conservation Fund, Conservation International Madagascar, Darwin Initiative

The subcellular distribution of folate co- enzymes in the brain is unknown. Brain folate concen trations are low and hence require a sensitive assay to determine the subcellular distribution. Rat brain was fractionated by differential centrifugation into cyto- plasmic, mitochondrial and crude synaptosomal frac tions. The compositions of the folate pools in these subcellular fractions were determined by differential conversion of one-carbon forms enzymatically to 5,10- methylenetetrahydrofolate (5,10CH2H4PteGlun) fol lowed by reaction of the 5,1 OCH2H4PteGlunwith thymi- dylate synthetase and (3H)fluorodeoxyuridylate to form ternary complexes, which were then separated as a function of polyglutamate chain length by isoelectric focusing, visualized by fluorography and quantified by densitometry. The distribution of the pteridine deriva tives in brain was very similar to the distribution of these derivatives in liver. Cytoplasm contained pri marily 5-methyltetrahydropteroylpolyglutamates with smaller amounts of unsubstituted tetrahydropteroyl- polyglutamates, whereas mitochondria contained ap proximately equal concentrations of unsubstituted and formyl-substituted tetrahydropteroylpolyglutamates. The subcellular distribution of polyglutamate deriva tives in brain, however, was different from that in liver. In the brain, the mitochondrial folates exhibited longer polyglutamate chains than did the cytoplasmic folates, a pattern opposite to that in the liver. Whereas the brain cytoplasmic pteroylpolyglutamates were primar ily penta and hexa glutamates, the brain mitochondrial pteroylpolyglutamates were primarily hexa and hepta glutamates. The brain also contained small but mea surable levels of oxidized folates, which were seen in crude synaptosomal fractions but not in cytoplasmic or mitochondrial fractions. J. Nutr. 126: 3077- 3082, 1996. Folate-dependent one-carbon metabolism is vital to all living cells. The one-carbon units generated in this pathway are essential for the synthesis of the purines and thymidylate and for the synthesis of the methyl group de novo. Biological folates exist in many different forms with differences either in the pteridine moiety or in the length of the poly-gamma-glutamate chain. The pteridine moiety can differ in the oxidation state of the B ring from folie acid (PteGlu),4 in which posi tions 5,6, 7 and 8 are fully unsaturated, to tetrahydrofo- late (H4PteGlu), in which these positions are fully satu rated (i.e., reduced). Although the unsaturated forms, PteGlu and dihydrofolic acid (H2PteGlu), have not been shown to have any specific biological function, both can be reduced to the tetrahydro form in biological systems. In addition, the one-carbon units that are sub stituted at the 5 and 10 nitrogens can vary in oxidation state from the formate oxidation state of 5-formyl

The ternary complex method for the determination of folylpolyglutamates was combined with procedures for interconverting folate derivatives to measure 28 different folate derivatives in the subcellular fractions of rat liver. Folates in the homogenate showed a typical distribution with nearly equal quantities of penta- and hexaglutamates and pteridine derivatives in decreasing order as follows : 1) methyl substituted folates [5-methyltetrahydropteroylglutamates], 2) unsubstituted folates [tetrahydropteroylglutamates + 5,10-methylenetetrahydropteroylglutamates], 3) formyl substituted folates [5-formyltetrahydropteroylglutamates + 10-formyltetrahydropteroylglutamates + 5,10-methenyl-tetrahydropteroylglutamates], and 4) oxidized folates [di-hydropteroylglutamates]. In the homogenate the methyl substituted folates exhibited a higher hexa :pentaglutamate ratio than did the other pteridine derivatives. As the fractionation proceeded toward purer subcellular components, the methyl substituted folates were found almost exclusively in the soluble fraction, and this fraction also contained the higher hexa :pentaglutamate ratio characteristic of the methyl substituted folates. The plasma membrane, the microsomal and the nuclear fractions did not contain appreciable folate. The mitochondrial fraction contained primarily formyl substituted and unsubstituted folates, and these folates exhibited the lower hexa :pentaglutamate ratios. These data support the hypothesis that folate-dependent one-carbon metabolism is compartmentalized in the eukaryotic cell. J. Nutr. 125 : 2096-2103, 1995.

Q-fever is a zoonotic disease caused by Coxiella burnetii that can create an acute or chronic form of the illness. In March 2014, Q-fever was identified by serology and Real-time Polymerase Chain Reaction (RT-PCR), in a 62 year-old male that was a Nepalese refugee. The male visited a livestock farm with a slaughterhouse in rural Central New York State, twenty-two days prior to onset of symptoms. He had direct handling of goats on this farm prior to slaughter. We describe the case presentation of his illness and the public health epidemiological investigation.

Most developing countries have failed to adopt hydroacoustics to aid with the management of their aquatic natural resources. We tested the ability of single-beam sonar (SBES) to discern and map substrates in three rivers from the largest wetland in Jamaica, the Black River Lower Morass (BRLM). We used five supervised classification methods (including C5.0; random forest, RF; and naïve Bayes, NB) and four interpolation algorithms (indicator kriging (iks), fixed path simulation (fpth), random path simulations (rpth) and multinomial categorical simulation (mcs) based on transitional rates and incorporated into Markov Chain). Irrespective of the classifier used, mcs consistently produced higher overall classification accuracies (OAC) and kappa statistics; however, rpth interpolation produced the lowest balanced error rate (BER) recorded. For all three rivers, OAC, kappa and BER statistics were 49.7–87.1, 32.8–81.0 and 15.3–45.1% respectively. All interpolation algorithms produced maps with higher OAC and kappa indices from data classified using the tree-based classifiers (C5.0 and RF) in the absence of gravel-free substrates. At a lower spatial resolution, comparable maps were obtained by interpolating discrete sample points acquired by grab samples. Given that most of rivers in island states are small, sinuous, shallow and sometimes non-navigable by boat, the use of SBES as the most cost-effective and efficient way of mapping river substrates is questionable, but the interpolation of grab samples might suffice.

Determining whether a conflict between gene trees and species trees represents incomplete lineage sorting (ILS) or hybridization involving native and/or invasive species has implications for reconstructing evolutionary relationships and guiding conservation decisions. Among vertebrates, turtles represent an exceptional case for exploring these issues because of the propensity for even distantly related lineages to hybridize. In this study we investigate a group of freshwater turtles (Trachemys) from a part of its range (the Greater Antilles) where it is purported to have undergone reticulation events from both natural and anthropogenic processes. We sequenced mtDNA for 83 samples, sequenced three nuDNA markers for 45 samples, and cloned 29 polymorphic sequences, to identify species boundaries, hybridization, and intergrade zones for Antillean Trachemys and nearby mainland populations. Initial coalescent analyses of phased nuclear alleles (using (*)BEAST) recovered a Bayesian species tree that strongly conflicted with the mtDNA phylogeny and traditional taxonomy, and appeared to be confounded by hybridization. Therefore, we undertook exploratory phylogenetic analyses of mismatched alleles from the "coestimated" gene trees (Heled and Drummond, 2010) in order to identify potential hybrid origins. The geography, morphology, and sampling context of most samples with potential introgressed alleles suggest hybridization over ILS. We identify contact zones between different species on Jamaica (T. decussata × T. terrapen), on Hispaniola (T. decorata × T. stejnegeri), and in Central America (T. emolli × T. venusta). We are unable to determine whether the distribution of T. decussata on Jamaica is natural or the result of prehistoric introduction by Native Americans. This uncertainty means that the conservation status of the Jamaican T. decussata populations and contact zone with T. terrapen are unresolved. Human-mediated dispersal events were more conclusively implicated for the prehistoric translocation of T. stejnegeri between Puerto Rico and Hispaniola, as well as the more recent genetic pollution of native species by an invasive pet turtle native to the USA (T. scripta elegans). Finally, we test the impact of introgressed alleles using the multispecies coalescent in a Bayesian framework and show that studies that do not phase heterozygote sequences of hybrid individuals may recover the correct species tree, but overall support for clades that include hybrid individuals may be reduced.

The 2-aminoaniline scaffold is of significant value to the pharmaceutical industry and is embedded in a number of pharmacophores including 2-aminoanilides and benzimidazoles. A novel application of coordination ion spray mass spectrometry (CIS-MS) for interrogating the silver ion (Ag(+)) complexes of a homologous series of these compounds using multi-stage tandem mass spectrometry is described. Unlike the ubiquitous alkali metal ion complexes, Ag(+) complexes of 2-aminoanilides and benzimidazoles were found to yield [M - H](+) ions in significant abundance via gas-phase elimination of the metal hydride (AgH) resulting in unique product ion cascades.Sample introduction was by liquid chromatography with mass spectrometry analysis performed on a hybrid linear ion trap/orbitrap instrument capable of high-resolution measurements.Rigorous structural characterization by multi-stage tandem mass spectrometry using [M + H](+), [M - H](-) and [M - H](+) precursor ions derived from ESI and CIS experiments was performed for the homologous series of 2-aminoanilide and benzimidazole compounds. A full tabular comparison of structural information resulting from these product ion cascades was produced.Multi-stage tandem mass spectrometry of [M - H](+) ions resulting from Ag(+) complexes of 2-aminoanilides and benzimidazoles in CIS-MS experiments produced unique product ion cascades that exhibited complementary structural information to that obtained from tandem mass spectrometry of [M + H](+) and [M - H](-) ions by electrospray ionization (ESI). These observations may be broadly applicable to other compounds that are observed to form Ag(+) complexes and eliminate AgH.

We examine seasonal and interpopulational variation in field levels of corticosterone (B) in the lizard Uta stansburiana. Corticosterone is the primary reptilian glucocorticosteroid, and elevated levels of this hormone have been correlated with physiological stress under both field and laboratory conditions. Patterns of seasonal variation in plasma B were generally similar in males and females, with peaks coinciding with periods of peak reproductive activity (males) or peak reproductive condition (females). Levels of circulating B usually declined as the activity season progressed and were lowest in late summer, especially among males at desert sites-including our southernmost site, where lizards exhibited poor body condition as a result of drought. Variation in B levels among populations was probably attributable to variation in the timing of seasonal samples (e.g., in relation to peaks in reproductive activity). Apparently, these populations did not experience serious (i.e., debilitating) physiological ...

The surge of oil prices in recent years has led to speculation that rising transportation costs could end the period of dramatic world trade growth Ñin the words of Rubin (2009), ÒÉYour world is going to get a whole lot smaller.Ó Using data from ChinaÕs Customs Statistics, we examine the impact of oil prices on tradeÕs sensitivity to distance. We find that higher oil prices increase tradeÕs elasticity to distance, but that the economic effect is small. We also find that the effect is more pronounced for trade within global production networks, and less large for goods shipped by air.

Jamaicas modern terrestrial herpetofauna includes 66 described species distributed among four amphibian and 10 reptile families. Jamaicas native amphibian fauna consists of 21 described species representing two genera; all of them are endemic and most are considered threatened based on IUCN Red List criteria. Continuing loss and degradation of remaining primary forests is undoubtedly the single greatest threat to the persistence of most threatened species. Sea turtle populations have been reduced to mere remnants due to of over-exploitation; and now the beaches that serve as nesting sites for the remaining populations, and for nesting American crocodiles, are under threat from tourism development. Another major concern is the presence of Batrachochytrium dendrobatidis, a fungal parasite that has been implicated in the extinction of amphibians worldwide. Halting the rampant cutting of trees in these areas, and effecting a moratorium on coastal development in sea turtle and crocodile nesting habitat are conservation priorities. Keywords: American crocodiles; amphibians; Batrachochytrium dendrobatidis; jamaica; reptiles; sea turtle; tourism development

31-O-Desmethylimmunomycin O: methyltransferase (DIMT), an enzyme involved in the biosynthesis of immunomycin (ascomycin/FR-900520), was used to synthesize three analogs of this immunosuppressant compound. These compounds were assigned the following structures: 13-O-desmethyl-, 15-O-desmethyl- and 13,15-O-bisdesmethyl-immunomycins. Two of these compounds, namely, 15-O-desmethyl- and 13,15-O-bismethyl-immunomycins have novel structures and were examined for possible immunosuppressive activity by in vitro T-cell proliferation assay. The results showed that methylation of the C-15 hydroxyl is critical for full biological activity of the immunomycin.

Eleanor and Byron Wenger were graduate students in the Department of Zoology in the 1940s. Both took several courses with Viktor, and he was thesis advisor for both of us. We have attempted to provide a summary of life in the department from a student perspective as well as our impression of Viktor's style of mentoring and guiding student research and education.

Coherence scanning microscopy is a new technique in high resolution imaging. It shares many of the features of confocal microscopy but uses coherence effects to enhance the lateral and longitudinal resolution rather than physical apertures. This approach has two significant implications for profilometry: the longitudinal resolution is decoupled from the lateral resolution, and interference effects can be used to further enhance the longitudinal resolution. We detail the features of coherence scanning profilometry and give some examples.

Active laser diode interferometers in which the interference signal is fed back to the diode current are investigated for Twyman-Green and self-coupling interferometers. The Twyman-Green interferometer is stabilized with a stabilization factor of more than 100. By using the feedback signal of either type of interferometer, displacement is measured in a linear scale over a dynamic range of 8-9,microm with a precision of 10-60 nm. The feedback signal vs displacement shows hysteresis and multistable behavior, in accordance with theoretical results.

Larvae and nymphs of Ixodes dammini Spielman, Piesman, Clifford & Corwin from a laboratory colony were fed on two white-tailed deer, Odocoileus virginianus (Zimmerman) inoculated with either the SH2-82 or JD-1 strains of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner. Ticks were exposed to one deer 43 and 69 d after inoculation of the spirochete and to a second deer 35 and 61 d after inoculation. Polymerase chain reaction assays amplified the 158 bp OspA DNA target sequence in 11.1% (n = 9) of fed larvae and 3.3% (n = 30) of nymphs from the deer inoculated with the SH2-82 strain, and 22.7% (n = 22) of larvae and 0% (n = 21) of nymphs from a second deer inoculated with the JD-1 strain of B. burgdorferi. One of three females derived from nymphs fed on one of the inoculated deer showed presence of B. burgdorferi DNA, but none of four males was positive. Experimentally inoculated deer can serve as a source of at least two geographic strains of B. burgdorferi to I. dammini larvae and nymphs for at least several weeks.

Forest fragmentation is one of the most important threats to global biodiversity, particularly in tropical developing countries. Identifying priority areas for conservation within these forests is essential to their effective management. However, this requires current, accurate environmental information that is often lacking in developing countries. The Cockpit Country, Jamaica, contains forests of international importance in terms of levels of endemism and overall diversity. These forests are under severe threat from the prospect of bauxite mining and other anthropogenic disturbances. In the absence of adequate, up-to-date ecological information, we used satellite remote sensing data and fragmentation analysis to identify interior forested areas that have experienced little or no change as priority conservation sites. We classified Landsat images from 1985, 1989, 1995, 2002, and 2008, using an object-oriented method, which allowed for the inclusion of roads. We conducted our fragmentation analysis using metrics to quantify changes in forest patch number, area, shape, and aggregation. Deforestation and fragmentation fluctuated within the 23-year period but were mostly confined to the periphery of the forest, close to roads and access trails. An area of core forest that remained intact over the period of study was identified within the largest forest patch, most of which was located within the boundaries of a forest reserve and included the last remaining patches of closed-broadleaf forest. These areas should be given highest priority for conservation, as they constitute important refuges for endemic or threatened biodiversity. Minimizing and controlling access will be important in maintaining this core.

It is often claimed that predation pressure on plants and animals increases toward the equator. Here I address the specific hypothesis that predation pressure is greater on lower latitude populations of the lizard Uta stansburiana. Standard mark-recapture techniques (10 997 captures of 5371 individuals) were used to estimate mortality rates for seven populations that lie along a transect of nearly 150 latitude (central Washington to extreme southeastern California, USA). Mortality was estimated for both the early (i.e., spring to summer) and late (i.e., summer to late summer or fall) portions of the activity season. As in previous studies of this species, I found that emigration was negligible for adult lizards. Thus, disappearance rates serve as reliable indices of mortality rates. Although predation is known to be a major source of mortality for populations of U. stansburiana, direct measurement (i.e., observation) of the demographic impact of pred- ators is impractical. My strategy was to examine the potential demographic importance of mortality sources other than predation (e.g., senescence, physiological stress). If alternate sources of mortality can be shown to be of trivial importance, then overall mortality rates can be used to infer variation in predation pressure. To assess the importance of these mortality factors I examined variation in mortality within sites (e.g., among seasons, years, and individuals) in relation to data about the lizards (e.g., age, physical condition) and about their environment (e.g., recent precipitation). My results suggest that predation is the only source of activity season mortality that is of demographic importance for these populations. For example, I found no evidence that physiological stress was ever an important source of mortality. Lizards in relatively poor physical condition (i.e., those with small length-corrected mass) did not experience a greater risk of mortality, and survival actually increased during the presumably more stressful late activity season. Mortality rates were also depressed during a drought at one site, despite the poor physical condition of the lizards. Low mortality rates during the late activity season and during drought conditions probably reflect reduced activity of U. stansburiana and their predators. Reduced activity levels discourage predator-prey encounters. Because sources of mortality other than predation appear to be of trivial demographic importance, overall mortality rates can be used to infer relative predation rates. Accord- ingly, I examined latitudinal variation in mortality rates to address the hypothesis that predation pressure is greater on lower latitude populations of U. stansburiana. Daily mor- tality rates were not higher among southern populations. Even annual losses to predators do not appear to be greater among lower latitude populations. These results were surprising because U. stansburiana is one of the species for which predation pressure was thought to increase with decreasing latitude. Higher than expected mortality rates in the north may in part be due to longer daily activity periods among northern Uta and their predators. Interestingly, several indirect measures of predation intensity (e.g., tail break frequencies, measures of predator species richness) did increase significantly from north to south. Thus, these less direct measures of predation pressure yielded a misleading impression of lati- tudinal variation in predation pressure.

Background Few studies have examined treatment rates in patients with multiple cardiovascular risk factors. This study assessed outpatient visit and treatment patterns among patients having ≥ 1 cardiovascular conditions. Methods Nationally representative outpatient survey data were used to identify patients ≥ 25 years with hypertension, hyperlipidemia, diabetes mellitus, ischemic heart disease or congestive heart failure during the year 2005 (n=15,060 records). Prevalence and visit patterns were examined for each cardiovascular condition by race/ethnicity, sex and age. Adherence to recommended treatment was also assessed using logistic regression. Results Prevalence rates generally increased with age, and several subgroup patterns were observed for some cardiovascular conditions. Visit rates were similar, with most patients seeing their providers about 3-4 times during the year. Hypertension, the most prevalent condition, had the highest treatment rate (88%) versus ischemic heart disease, one of the least prevalent conditions, which had the lowest treatment rate (28%). Treatment rates decreased with increasing numbers of cardiovascular conditions. Appropriate treatment was independently associated with decreasing numbers of cardiovascular conditions, treatment by the primary care provider and treatment with a combination agent—but not race/ethnicity, sex or primary payment source. Conclusions While patients with multiple cardiovascular conditions visit their providers several times during the year, they are still largely undertreated, particularly as their cardiovascu lar disease burden increases. These findings may suggest that patients with multiple cardiovascular conditions are getting lower-quality care because of the greater demands placed on their physicians. Adherence to treatment guidelines may improve with adoption of a polypill and by encouraging patients to have a primary care home.

A novel method for preparation of 1‐substituted benzimidazoles via reductive amination of ketones with N‐differentiated 1,2‐diaminobenzenes is described. The method appears to be general in application to acyclic and cyclic ketones, as well as heteroatom‐substituted cyclic ketones.

Prior to weaning, medium-chain fatty acids constitute an important energy source in the developing rat. Fatty acid oxidation rates increase with age in most developing tissues, but the pattern of this increase may vary according to the role of the particular organ. In skeletal muscle, heart, and liver of developing rats, we measured mitochondrial activities of long- and short-chain enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, and long- and short-chain acyl-CoA thiolase. In skeletal muscle, the pattern of development in fatty acid oxidation enzymes favored utilization of long-chain rather than medium-chain fatty acids. In liver, enzyme activities for medium-chain fatty acids were highest prior to weaning. Heart occupied a position intermediate between skeletal muscle and liver.

BACKGROUND: Carotid endarterectomy (CEA) has been shown to decrease future ischemic stroke risk in selected patients. However, clinical trials did not examine the risk-benefit ratio for nonwhites, who have a greater ischemic stroke risk than whites. In general, few studies have examined the effects of race on CEA use and complications, and data on race and CEA readmission are lacking. METHODS: This study used administrative data for patients discharged from California hospitals between January 1 and December 31, 2000. Selection criteria of cases included: ICD-9 principal procedure code 38.12, principal diagnostic code 433 and diagnosis-related group 5. There were 8,080 white and 1196 nonwhite patients (228 blacks, 643 Hispanics, 325 Asians/Pacific Islanders) identified that underwent an elective and isolated CEA. For both groups, CEA rates were compared. Logistic regression was used to examine the independent effects of race on in-hospital death and stroke, as well as CEA readmission. RESULTS: Rates of CEA use were more than three times greater for whites than nonwhites, although nonwhites were more likely to have symptomatic disease. For all patients, the complication rate was 1.9%. However, the odds of in-hospital death and stroke were greater for nonwhites than whites, but after adjustment for patient and hospital factors, these differences were only significant for stroke (OR = 1.7, P = 0.013). For both outcomes, the final models had good predictive accuracy. Overall, CEA readmission risk was 7%, and no significant racial differences were observed (P = 0.110). CONCLUSIONS: The data suggest that CEA is performed safely in California. However, nonwhites had lower rates of initial CEA use but higher rates of in-hospital death and stroke than whites. Racial differences in stroke risk persisted after adjustment for patient and hospital factors. Finally, this study found that despite significant racial disparities in initial CEA use, whites and nonwhites were similar in their CEA readmission rates. These findings may suggest that screening initiatives are lacking for nonwhites, which may increase their risk for poorer outcomes.

BACKGROUND: Although it is known that the risk of first-ever stroke is higher for blacks than for whites, it is unclear what their relative risk is for stroke recurrence. METHODS: Using statewide inpatient data from California, 4,784 blacks and 33,684 whites having one or more stroke admissions during the year 2000 were identified. For blacks and whites, age- and sex-adjusted incidence rates were calculated for the index stroke admission using direct standardization (to the U.S. resident population for the year 2000). Various statistical models for count data were applied, with the best one being used in subsequent age-specific multivariate analyses for the number of stroke admissions. RESULTS: For the index stroke admission, the age- and sex-adjusted incidence rate per 100,000 was 366 (95% CI 355-377) for blacks and 204 (95% CI 202-207) for whites. Those having two or more stroke admissions accounted for less than 20% of the total number of patients. The truncated negative binomial (TNB) model gave the best fit not only to the California data but also to the data reanalyzed from several prior studies done in various countries [i.e., the United Kingdom (Oxfordshire and South London), Switzerland (Lausanne). Australia (Western Australia) and the United States (Nueces County, TX)]. In this study, predictors of stroke readmission changed according to age. For those aged 65-74 years old, blacks showed a higher risk of readmission than whites by 40% after adjustment for patient and hospital factors (RR 1.40, 95% CI 1.19-1.64). This excess risk was lower in other age groups. CONCLUSIONS: These findings suggest that blacks remain a high-risk group after an initial stroke and warrant appropriate intervention. Future studies on recurrent stroke should consider age-specific TNB models.