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BACKGROUND: Consensus on the etiology of 1991 Gulf War illness (GWI) has been limited by lack of objective individual-level environmental exposure information and assumed recall bias. OBJECTIVES: We investigated a prestated hypothesis of the association of GWI with a gene–environment (GxE) interaction of the paraoxonase-1 (PON1) Q192R polymorphism and low-level nerve agent exposure. METHODS: A prevalence sample of 508 GWI cases and 508 nonpaired controls was drawn from the 8,020 participants in the U.S. Military Health Survey, a representative sample survey of military veterans who served during the Gulf War. The PON1 Q192R genotype was measured by real-time polymerase chain reaction (RT-PCR), and the serum Q and R isoenzyme activity levels were measured with PON1-specific substrates. Low-level nerve agent exposure was estimated by survey questions on having heard nerve agent alarms during deployment. RESULTS: The GxE interaction of the Q192R genotype and hearing alarms was strongly associated with GWI on both the multiplicative [prevalence odds ratio (POR) of the interaction = 3.41; 95% confidence interval (CI): 1.20, 9.72] and additive (synergy index = 4.71; 95% CI: 1.82, 12.19) scales, adjusted for measured confounders. The Q192R genotype and the alarms variable were independent (adjusted POR in the controls = 1.18; 95% CI: 0.81, 1.73; 푝= 0.35), and the associations of GWI with the number of R alleles and quartiles of Q isoenzyme were monotonic. The adjusted relative excess risk due to interaction (aRERI) was 7.69 (95% CI: 2.71, 19.13). Substituting Q isoenzyme activity for the genotype in the analyses corroborated the findings. Sensitivity analyses suggested that recall bias had forced the estimate of the GxE interaction toward the null and that unmeasured confounding is unlikely to account for the findings. We found a GxE interaction involving the Q-correlated PON1 diazoxonase activity and a weak possible GxE involving the Khamisiyah plume model, but none involving the PON1 R isoenzyme activity, arylesterase activity, paraoxonase activity, butyrylcholinesterase genotypes or enzyme activity, or pyridostigmine. DISCUSSION: Given gene–environment independence and monotonicity, the unconfounded aRERI >0 supports a mechanistic interaction. Together with the direct evidence of exposure to fallout from bombing of chemical weapon storage facilities and the extensive toxicologic evidence of biochemical protection from organophosphates by the Q isoenzyme, the findings provide strong evidence for an etiologic role of low-level nerve agent in GWI [ABSTRACT FROM AUTHOR]

Abstract: Pomalidomide is an immunomodulatory drug, and the dosage of 4 mg per day taken orally on days 1‐21 of repeated 28‐day cycles has been approved in the European Union and the United States to treat patients with relapsed/refractory multiple myeloma. In vitro data showed that pomalidomide is a substrate of multiple cytochrome P450 (CYP) isozymes and that its oxidative metabolism is mediated primarily by CYP1A2 and CYP3A4, with minor contributions from CYP2C19 and CYP2D6. The effect of CYP1A2 inhibition by fluvoxamine (a strong CYP1A2 inhibitor) and CYP1A2 induction by smoking on pomalidomide pharmacokinetics in healthy subjects has been assessed in 2 separate phase 1 open‐label, single‐dose studies. Following administration of a single oral dose of 4 mg pomalidomide, the plasma exposure when coadministered with fluvoxamine was 225.1% and 123.7% of that when administered alone for the total plasma exposure (AUC0‐inf) and the plasma peak exposure (Cmax), respectively. In smokers with elevated CYP1A2 activity demonstrated by high caffeine clearance (a marker of CYP1A2 induction), the AUC0‐inf was 32.3% lower, whereas the Cmax was 14.4% higher than that in nonsmokers. In addition, pomalidomide was safe and well tolerated as a single oral dose of 4 mg in healthy male smokers and nonsmokers ≥ 40 to ≤ 80 years old, and a single oral dose of 4 mg pomalidomide coadministered with multiple oral 50‐mg doses of the CYP1A2 inhibitor fluvoxamine compared with pomalidomide alone was safe and well tolerated by the healthy male subjects. [ABSTRACT FROM AUTHOR]

An introduced species' propagule pressure strongly influences the genetic diversity and evolutionary potential of its descendants and even the likelihood of biological invasion. We examined population genetic consequences arising from introduction of the invasive annual grass Bromus tectorum into the central United States (U.S.). The origin and frequency of introductions were investigated by assembling allozyme diversity data from 60 widely spaced populations. At least five introduction events contributed to the grass's genetic diversity in the central U.S. Populations in this region have fewer alleles (30 vs. 43) and polymorphic loci (5 vs. 13) than native populations, evidence of a genetic bottleneck. However , the populations are, on average, more genetically diverse and less structured than native populations. Assembly within central U.S. populations of previously allopatric genotypes may have allowed the formation, via outcrossing, of a rare multilocus genotype. Genetic admixtures may have occurred through any combination of east-to-west spread coincident with nineteenth-century arrival of European settlers, dispersal from southern Ontario via Great Lakes shipping and commerce, and direct introduction from the native range. Our results illustrate the population genetic consequences of relatively high propagule pressure (i.e., repeated immigrations to a new range from multiple sources). [ABSTRACT FROM AUTHOR]

Background and Purpose: Inosine monophosphate dehydrogenases, encoded by IMPDH1 and IMPDH2, are targets for the important immunosuppressive drug, mycophenolic acid (MPA). Variation in MPA response may result, in part, from genetic variation in IMPDH1 and IMPDH2.Experimental Approach: We resequenced IMPDH1 and IMPDH2 using DNA from 288 individuals from three ethnic groups and performed functional genomic studies of the sequence variants observed.Key Results: We identified 73 single nucleotide polymorphisms (SNPs) in IMPDH1, 59 novel, and 25 SNPs, 24 novel, in IMPDH2. One novel IMPDH1 allozyme (Leu275) had 10.2% of the wild-type activity as a result of accelerated protein degradation. Decreased activity of the previously reported IMPDH2 Phe263 allozyme was primarily due to decreased protein quantity, also with accelerated degradation. These observations with regard to the functional implications of variant allozymes were supported by the IMPDH1 and IMPDH2 X-ray crystal structures. A novel IMPDH2 intron 1 SNP, G > C IVS1(93), was associated with decreased mRNA quantity, possibly because of altered transcription.Conclusions and Implications: These results provide insight into the nature and extent of sequence variation in the IMPDH1 and IMPDH2 genes. They also describe the influence of gene sequence variation that alters the encoded amino acids on IMPDH function and provide a foundation for future translational studies designed to correlate sequence variation in these genes with outcomes in patients treated with MPA. [ABSTRACT FROM AUTHOR]

Type 2 diabetes mellitus traditionally has been characterized by insulin resistance and β-cell dysfunction, leading to hyperglycemia and eventual micro- and macrovascular complications. Dipeptidyl peptidase-4 (DPP-4) inhibitors are a relatively new class of drugs available for the management of type 2 diabetes. In order to provide a comprehensive evaluation and comparison of the pharmacology, pharmacokinetics, efficacy, and safety of the DPP-4 inhibitors--sitagliptin, vildagliptin, saxagliptin, and alogliptin--in the treatment of type 2 diabetes, we conducted a MEDLINE search (1966-July 2009) for pertinent English-language articles. Abstracts of the annual meetings of the American Diabetes Association and European Association lot the Study of Diabetes from 2005-2009 were also searched. As a drug class, the DPP-4 inhibitors have become widely accepted in clinical practice because of their low risk of hypoglycemia, favorable adverse-effect profile, and once-daily dosing. They are weight neutral (do not cause weight gain or loss) and appear to decrease β-cell apoptosis and increase β-cell survival. Because clinical studies directly comparing agents from this class have not, to our knowledge, been conducted, making comparisons in terms of efficacy and safety will become difficult for clinicians as more agents become available. Based on information front preclinical, clinical, and postmarketing data, there does not appear to be a compelling advantage of one DPP-4 inhibitor over another in terms of efficacy, safety, or ease of clinical use. Although theoretical advantages exist for agents with a higher specificity for DPP-4 inhibition versus inhibition of other isoenzymes associated with toxicity, comparative studies and/or increased clinical experience with this class of drug will determine the clinical advantages, if any, of one agent over another. [ABSTRACT FROM AUTHOR]

The cytochrome P450 (CYP) gene family catalyzes drug metabolism and bioactivation and is therefore relevant to drug development. We determined potency values for 17,143 compounds against five recombinant CYP isozymes (1A2, 2C9, 2C19, 2D6 and 3A4) using an in vitro bioluminescent assay. The compounds included libraries of US Food and Drug Administration (FDA)-approved drugs and screening libraries. We observed cross-library isozyme inhibition (30–78%) with important differences between libraries. Whereas only 7% of the typical screening library was inactive against all five isozymes, 33% of FDA-approved drugs were inactive, reflecting the optimized pharmacological properties of the latter. Our results suggest that low CYP 2C isozyme activity is a common property of drugs, whereas other isozymes, such as CYP 2D6, show little discrimination between drugs and unoptimized compounds found in screening libraries. We also identified chemical substructures that differentiated between the five isozymes. The pharmacological compendium described here should further the understanding of CYP isozymes. [ABSTRACT FROM AUTHOR]

Abstract  Southern chinch bug, Blissus insularis Barber (Hemiptera: Blissidae), is a serious insect pest of St. Augustinegrass, Stenotaphrum secundatum (Walt.) Kuntze, a turfgrass commonly grown in the southeastern United States. Resistance to southern chinch bug has been identified in the polyploid St. Augustinegrass varieties ‘Floratam’ and ‘FX-10’, and the diploid ‘Captiva’. However, southern chinch bug in Florida and elsewhere has overcome Floratam’s resistance. This research investigated the potential role of selected plant oxidative enzymes in resistance/susceptibility to southern chinch bug in two polyploid varieties (FX-10 and Floratam) and two diploid varieties (Captiva and Palmetto). Oxidative enzyme activity was estimated spectrophotometrically from plant samples collected 1, 3, 5, and 8 days after southern chinch bug infestation and from uninfested control plants. Resistant FX-10 and Captiva had significantly higher peroxidase activity, while Captiva had significantly higher polyphenol oxidase activity 5 and 8 days after infestation compared to uninfested controls. FX-10 had higher lipoxygenase activity 3, 5, and 8 days after infestation compared to uninfested controls. Catalase activities did not differ between infested and control plants in any of the varieties tested. Native gels stained for peroxidase indicated that certain isozymes in FX-10 and Captiva were induced 5 and 8 days after infestation. Isozyme profiles of polyphenol oxidase and lipoxygenase did not differ between control and infested FX-10, Floratam, Captiva, and Palmetto. Potential mechanisms to explain the correlation of resistance to southern chinch bug in FX-10 and Captiva with higher activities of oxidative enzymes are discussed. [ABSTRACT FROM AUTHOR]

Based on the data of Russian and foreign researchers, a database, consisting of 100 allozyme-coding loci examined in 288 chum salmon populations from Asia and Northern America, was constructed. Using G-test, genetic heterogeneity of Asian population samples of chum salmon was evaluated. Correlations between the frequencies of major alleles and geographic latitude of the mouths of native rivers were estimated. Using the methods of Nei and Cavalli-Sforza and Edwards, for different local chum salmon stock groups the genetic distances at the number of polymorphic enzyme loci were determined. Analysis of these distances made it possible to evaluate the patterns of genetic diversity in regional population groups from the Russian Far East, Japan, and North America. The proportions of genetic variation at each hierarchical level, identified in accordance with the geographical positions of the populations, were estimated through partitioning of variation in Asian populations into within and between-population components. It was demonstrated that intraspecific genetic structure of chum salmon corresponded geographic subdivision into regional population groups. [ABSTRACT FROM AUTHOR]

The hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera Adelgidae), is a major introduced pest of eastern hemlock, Tsuga canadensis (L.) Carrière. Hemlock woolly adelgid in the United States is anholocyclic and an obligate parthenogen, because no suitable primary host (on which sexual reproduction occurs in Asia) is reported for this adelgid in the United States. Allozyme analyses were conducted to assess the relatedness between three hemlock woolly adelgid populations in the eastern United States (Connecticut, New Jersey, and Virginia) and to compare them with adelgids from the western United States (Washington) and China. Significant hemlock woolly adelgid allozyme variation was found between nonadjacent trees within a site in the eastern United States. There was a small difference between the two northern and the southern populations despite the relative genetic uniformity between the sites across the allozyme loci evaluated. There were low numbers of protein alleles in the eastern populations, whereas the western and Chinese populations had additional alleles not found in the eastern populations. Both heterozygote excesses and deficits were detected as would be expected in populations that are not randomly mating. There were only a few abundant genotypes and they tended to be more homozygous than the rarer genotypes. The hemlock woolly adelgid population from China that is cyclically parthenogenic was more genetically diverse than the other hemlock woolly adelgid populations that are presumed to be obligately parthenogenic. Allozymes provide some useful information about genetic variation in hemlock woolly adelgid but seem to be less suited to assess actual genetic diversity and structure of populations because of the small size of the hemlock woolly adelgid. [ABSTRACT FROM AUTHOR]

Etravirine is the first next-generation nonnucleoside reverse-transcriptase inhibitor (NNRTI) that is approved for the treatment of HIV infection in patients who have experienced virologic failure while receiving an NNRTI-containing regimen. The drug is taken as two 100-mg tablets twice daily after a meal. Because the drug is metabolized by cytochrome P450 isoenzymes, it cannot be coadministered with a number of other drugs (fosamprenavir, high-dose ritonavir, atazanavir, rifampin, and several antiepileptic medications). Etravirine demonstrates potent in vitro activity against wild-type and NNRTI-resistant strains of HIV. In vitro resistance and treatment failure is associated with the development of multiple NNRTI resistance mutations other than the K103N mutation. Several large clinical studies have documented the benefit of adding etravirine to an optimized background regimen in patients with virologic failure who are infected with multidrug-resistant HIV. The major adverse effects of etravirine therapy are nausea and rash, which are typically self-limiting and do not lead to treatment discontinuation. [ABSTRACT FROM AUTHOR]

Eastern hemlock (Tsuga canadensis [L.] Carr.) is a widespread and ecologically important conifer species of eastern North America that is threatened by the hemlock woolly adelgid (Adelges tsugae Annand), a pest introduced into the United States from Asia in the 1920s. Information about the genetic composition of eastern hemlock is necessary to guide ex situ conservation efforts in the southeastern United States, where the species is expected to harbor relatively high amounts of genetic variation in areas of Pleistocene glacial refuge. Nineteen allozyme markers were used to quantify the genetic variation present in 20 eastern hemlock populations in the southeastern United States. Results indicate that the species has low levels of genetic diversity in the region compared to most other conifers, but greater population differentiation (FST = 0.126). Populations along the eastern periphery and in the Appalachian interior exhibited higher levels of diversity than those along the western periphery of its geographic range. The results suggest that the glacial refuge area for eastern hemlock was likely located east of the southern Appalachian Mountains, and indicate that ex situ conservation seed collections should be concentrated in these areas of higher diversity. [ABSTRACT FROM AUTHOR]

Cardiovascular disease is the leading cause of death in the United States. Therefore, identifying therapeutic targets is a major focus of current research. Protein kinase C (PKC), a family of serine/ threonine kinases, has been identified as playing a role in many of the pathologies of heart disease. However, the lack of specific PKC regulators and the ubiquitous expression and normal physiological functions of the 11 PKC isozymes has made drug development a challenge. Here we discuss the validity of therapeutically targeting PKC, an intracellular signaling enzyme. We describe PKC structure, function, and distribution in the healthy and diseased heart, as well as the development of rationally designed isozyme-selective regulators of PKC functions. The review focuses on the roles of specific PKC isozymes in atherosclerosis, fibrosis, and cardiac hypertrophy, and examines principles of pharmacology as they pertain to regulators of signaling cascades associated with these diseases. [ABSTRACT FROM AUTHOR]

The article investigates the association of elevated troponin and creatine phosphokinase isoenzyme levels with mortality and organ failure in subjects with acute respiratory distress syndrome (ARDS) in the U.S. The ARDS is characterized by pulmonary and systemic inflammation and pulmonary endothelial and epithelial injury that result in alveolar filling and respiratory failure. It concludes that patients with ARDS have a high prevalence of elevated cardiac markers.

The southeastern United States harbors an unusually large number of endemic plant taxa, which may reflect the refugial nature of the region during Pleistocene glacial maxima. Understanding the genetic diversity and structure of extant plant taxa can provide insights into the biogeographical processes that shaped them genetically. Here, we investigate the levels and partitioning of allozyme diversity in the southeastern North American endemic, Ceratiola ericoides, which displayed greater genetic variation and structure than other endemics. Central Florida populations represent a center of genetic diversity, whereas South Carolina and Georgia Fall Line sandhill populations have a subset of the Central Florida genetic diversity, and may be relicts of a once continuous distribution. This much broader, continuous distribution throughout the southeastern United States occurred during glacial maxima when the scrub habitat, dominated by C. ericoides, expanded considerably owing to drier climatic conditions. Georgia Coastal Plain populations appear to have been independently founded more recently by propagules from Central Florida and the Fall Line sandhills because they have an even more limited subset of genetic diversity and greater genetic heterogeneity among populations. Since their establishment, coastal plain populations appear to have had little, if any, gene exchange among each other or with the relatively proximate Fall Line sandhill populations. These data underscore the importance of understanding the genetic composition and historical biogeography of species before intelligent management or restoration decisions can be made regarding their preservation. [ABSTRACT FROM AUTHOR]

A single population of Pediomelum piedmontanum (Fabaceae) occurs in Columbia County, Georgia. We examined allozyme variation in this population for 20 loci in eleven enzyme systems. Genetic diversity was low (P = 20.0%; A = 1.20; overall average HO = 0.038). Allelic frequencies in a large sample from one of two subpopulations predicted a significant deficiency of heterozygotes for all polymorphic loci (P < 0.001), inconsistent with Hardy-Weinberg expectations. Allelic frequencies for a smaller sample from the other subpopulation predicted a significant deficiency of heterozygotes for one polymorphic locus (P < 0.025) and non-significant excesses of heterozygotes for two others. Genetic differentiation among subpopulations was low (FST = 0.0142). Factors responsible for the extreme rarity of P. piedmontanum are unknown, but low genetic variation in the small, isolated Georgia population is most likely due to historical factors, genetic drift and perhaps inbreeding. [ABSTRACT FROM AUTHOR]

Variation in the allele frequencies of five microsatellite loci was surveyed in 1256 individual spotted seatrout (Cynoscion nebulosus) obtained from 12 bays and estuaries from Laguna Madre, Texas, to Charlotte Harbor, Florida, to St. John's River on the Florida Atlantic Coast. Texas and Louisiana collection sites were resampled each year for two to four years (1998-2001). Genetic differentiation was observed. Spotted seatrout from Florida waters were strongly differentiated from spotted seatrout collected in Louisiana and Texas. The greatest genetic discontinuity was observed between Tampa Bay and Charlotte Harbor, and Charlotte Harbor seatrout were most similar to Atlantic Coast spotted seatrout. Texas and Louisiana samples were not strongly structured within the northwestern Gulf of Mexico and there was little evidence of temporal differentiation within bays. These findings are contrary to those of earlier analyses with allozymes and mitochondrial DNA (mtDNA) where evidence of spatial differentiation was found for spotted seatrout resident on the Texas coast. The differences in genetic structure observed among these markers may reflect differences in response to selective pressure, or may be due to differences in underlying genetic processes. [ABSTRACT FROM AUTHOR]

Seabob shrimps of the genus Xiphopenaeus are important fishery resources along the Atlantic and Pacific coasts of Central and South America. The genus was considered to comprise two species: the Atlantic Xiphopenaeus kroyeri (Heller, Sitzungsber Math Naturwiss cl kaiserliche Akad Wiss Wien 45:389–426, 1862), and the Pacific Xiphopenaeus riveti (Bouvier, Bull Mus Hist Nat Paris 13:113–116, 1907). In a recent review, Xiphopenaeus was regarded as a monotypic genus, on the basis that no clear morphological differences could be found between Pacific and Atlantic specimens (Pérez Farfante and Kensley, Mem Mus Nat Hist Nat Paris 175:1–79, 1997). In the present work, nuclear (allozymes), and mitochondrial (Cytochrome Oxidase I) genes were used to demonstrate the validity of X. riveti and reveal the presence of two cryptic species of Xiphopenaeus within X. kroyeri in the Atlantic Ocean. The high levels of molecular divergence among these species contrast with their high morphological resemblance. Interspecific sequence divergences (Kimura 2-parameter distance) varied from 0.106 to 0.151, whereas intraspecific distances ranged from 0 to 0.008 in Xiphopenaeus sp. 1, from 0 to 0.003 in Xiphopenaeus sp. 2, and from 0.002 to 0.005 in X. riveti. In addition, five diagnostic allozyme loci were found between sympatric samples of Xiphopenaeus sp. 1 and 2 along the Brazilian coast. The results suggest that Xiphopenaeus sp. 2 from the Atlantic is more closely related to the Pacific X. riveti than to the Atlantic Xiphopenaeus sp. 1. Furthermore, a high level of genetic structuring ( Xiphopenaeus sp. 1: F ST =0.026; P<0.05; Xiphopenaeus sp. 2: F ST =0.055; P<0.01) was found in the Brazilian Xiphopenaeus populations, indicating the presence of different genetic stocks in both Atlantic species. These findings have important commercial implications as they show that the fisheries of the two Atlantic species must be managed separately, and that each one is comprised of different populations. [ABSTRACT FROM AUTHOR]

A new species of ground cricket in the genus Allonemobius (Hebard) is described from the southwestern United States. Like many singing Orthoptera, this species is morphologically cryptic and most easily distinguished from related species by using molecular characters and male calling song traits. We describe Allonemobius shalontaki as a new species and present data suggesting its reproductive isolation from congeneric species. Allonemobius shalontaki exhibits a unique male calling song and possesses a distinct allozyme genotype. Additionally, we present an electrophoretic key to the genus and propose phylogenetic relationships among species. [ABSTRACT FROM AUTHOR]

The article reports on the clearance issued by the U.S. Food and Drug Administration to the AmpliChip CYP450 Test for determining the genotype of a patient's cytochrome P-450 isoenzyme 2D6 from Roche Molecular Systems Inc. It metabolizes a variety of medications, including many antipsychotics and antidepressants. The product can identify from a whole-blood sample.

The few studies that have investigated levels of genetic variation in liverworts have found very little polymorphism. Our electrophoretic data show, however, that the leafy liverwort Porella platyphylla maintains high levels of genetic variation in at least some natural populations from the southeastern United States. Within a single population from southwestern North Carolina, we detected 26 distinct multilocus genotypes and more than 80% of the enzyme loci we surveyed were polymorphic. It seems likely that earlier studies of mostly thalloid species from glaciated regions of Europe have presented a biased picture of levels of variation in liverwort populations. [ABSTRACT FROM AUTHOR]

Abstract Cherimoya (Anonna cherimola Mill.) is a fruit tree which originated in Peru and Ecuador and is now cultivated in several subtropical areas of the world. The characterization of cherimoya cultivars at allozyme level has been previously reported, but the geographic distribution and organization of this variation have not been fully characterized. In this study, we assessed the relationships among 206 cherimoya and four atemoya (A. cherimola A. squamosa) cultivars based on allozyme polymorphism. We have confirmed the genetic differences between atemoya and cherimoya cultivars, and showed that cherimoya accessions from Madeira, Bolivia and Spain form homogeneous groups of cultivars. Accessions from Chile and California form heterogeneous groups, probably due to their mixed origins. Cultivars from Peru and Ecuador showed a wide range of allelic variation, as is expected for accessions from the center of origin of this species. [ABSTRACT FROM AUTHOR]

We studied geographic variation in allozymes (22 loci), mitochondrial cytochrome b gene sequences (575 bp), advertisement calls (pulse rate, call duration, and dominant frequency), and snout-vent length among populations of Hyla wrightorum and Hyla eximia in the United States and Mexico. Calls were only available for H. wrightorum, and although populations varied in some advertisement call variables, there was no indication of species level differentiation. Allozyme variation was exhibited among the H. wrightorum populations, but no fixed differences were discovered, and the amount of genetic divergence among populations was small (Dm ≤ 0.0643). Seven mtDNA haplotypes were discovered among the H. wrightorum individuals included in this study. A single haplotype (G) was present in the Huachuca Mountains and was found only in this population restricted to southeast Arizona. Neither the Mogollon Rim nor the Sonora populations were exclusive, with some haplotypes in each being more closely related to haplotypes in the other population. Molecular data (allozymes and mtDNA), as well as the advertisement calls, support continued recognition of two species: H. eximia in central-southern Mexico and H. wrightorum, which consists of disjunct populations in the Sierra Madre Occidental of northern Mexico, the Huachuca Mountains of southeastern Arizona, and the mountains of central Arizona and western New Mexico. [ABSTRACT FROM AUTHOR]

The rate of introduction of exotic marine species has dramatically increased during the 19th and 20th centuries. Exemplifying this trend, the marine gastropod Ocinebrellus inornatus was first detected outside its native range in 1924 on the American Pacific coast, then in 1995 on the French Atlantic coast. To determine the origin of the French populations of this invasive species, we compared a French population with populations collected in Asia—the native range—and with a population collected in the United States. Analyses of mitochondrial DNA and allozyme polymorphism revealed that the French and American populations were closely related and substantially differentiated from the Asian populations. According to our results, the most likely scenario is that the source population of the French Atlantic coast populations was located in the United States. Indeed, taken altogether, the genetic structure of Asian populations, the time lag separating the introduction on the American Pacific coast from the introduction on the French Atlantic coast and the high level of genetic diversity in the two introduced areas (indicating an absence of major founder events) are hardly compatible with a scenario in which French population resulting only from primary introduction events from the native area. Finally, although similar, the French and American populations were not identical. Thus, even if the main source population of the French populations was located in the United States, the genetic structure of French populations may have been modified by cryptic and recurrent introduction events directly from Asia. [Copyright &y& Elsevier]

Volcanic activity on the island of Hawaii results in a cyclical pattern of habitat destruction and fragmentation by lava, followed by habitat regeneration on newly formed substrates. While this pattern has been hypothesized to promote the diversification of Hawaiian lineages, there have been few attempts to link geological processes to measurable changes in population structure. We investigated the genetic structure of three species of Hawaiian spiders in forests fragmented by a 150-year-old lava flow on Mauna Loa Volcano, island of Hawaii: Tetragnatha quasimodo (forest and lava flow generalist), T. anuenue and T. brevignatha (forest specialists). To estimate fragmentation effects on population subdivision in each species, we examined variation in mitochondrial and nuclear genomes (DNA sequences and allozymes, respectively). Population subdivision was higher for forest specialists than for the generalist in fragments separated by lava. Patterns of mtDNA sequence evolution also revealed that forest specialists have undergone rapid expansion, while the generalist has experienced more gradual population growth. Results confirm that patterns of neutral genetic variation reflect patterns of volcanic activity in some Tetragnatha species. Our study further suggests that population subdivision and expansion can occur across small spatial and temporal scales, which may facilitate the rapid spread of new character states, leading to speciation as hypothesized by H. L. Carson 30 years ago. [ABSTRACT FROM AUTHOR]

A total of 13 representative isolates of Fusarium oxysporum f. sp. melonis (FOM) from Iran, USA and France, eight isolates of seven formae speciales from Iran and one isolate of F. oxysporum f. sp. niveum from the USA were compared based on isozyme analysis and soluble mycelial protein pattern. Isozyme analyses of alkaline phosphatase (ALP), catalase (CAT), esterase (EST), malate dehydrogenase (MDH), superoxide dismutase (SOD) and xanthine dehydrogenase (XDH) revealed polymorphism among the F. oxysporum isolates in which 22 electrophoretic phenotypes (EP) were determined. At least 10 putative loci for these six enzymes were detected and they were all polymorphic. Maximum genetic diversity was observed in CAT, EST and XDH loci. Using UPGMA, the 22 isolates were separated into three main groups with one of the groups divided into two subgroups. Group I included isolates belonging to five formae speciales from Iran, whereas group II that included FOM isolates from both Iran and the USA was divided into two subgroups each containing the vast majority of the respective isolates from either country. Group III constituted FOM isolates from France and one pathogenic isolate on pepper from Iran. FOM isolates representing five different geographical regions from Iran belonged to two different races of 1 and 1,2Y and one vegetative compatibility group (VCG)0134 and thus were genetically homologous. Isozyme polymorphism in these isolates was highly correlated with VCG and geographical origins and to a lesser extent with races. Variations in soluble protein profile in FOM isolates were correlated with genetic distances determined in isozyme analysis. This study suggests that isozyme analysis could be a useful tool for identifying genetic diversity not only in FOM but also several formae speciales of F. oxysporum. [ABSTRACT FROM AUTHOR]

Stock structure of eastern Pacific yellowfin tuna was investigated by analyzing allozymes and random amplified polymorphic DNAs (RAPDs) from 10 samples of 20-30 individuals each, collected between 1994 and 1996 from fishing vessels operating in the Inter-American Tropical Tuna Commission (IATTC) yellowfin regulatory area (CYRA). Allozyme analysis resolved 28 loci, eight of which were polymorphic under the 0.95 criterion: Aat-S*, Glud, Gpi-F*, Gpi-S*, La, Lgg, Pap-F*, and 6-Pgd, resulting in a mean heterozygosity over all allozyme loci of H = 0.052. Four polymorphic RAPD loci were selected for analysis, resulting in a mean heterozygosity of H = 0.43. Eight of 45 pairwise comparisons of allozyme allele frequencies among the ten samples showed significant differences after correction for multiple testing (P<0.0001), all of which involved comparisons with the Gulf of California sample. Confirmation of this signal of population structure would have management implications. No significant divergence in RAPD allele frequencies was observed among samples. Weir and Cockerham θ estimated for allozyme loci (θ=0.048; P<0.05) and RAPD loci (θ=0.030; P>0.05) revealed little population structure among samples. Mantel tests demonstrated that the genetic relationships among samples did not correspond to an isolation-by-distance model for either class of marker. Four of eight comparisons of coastal and offshore samples revealed differences of allele frequencies at the Gpi-F* locus (P<0.05), although none of these differences was significant after correction for multiple testing (P>0.001). Results are consistent with the hypothesis that the CYRA yellowfin tuna samples comprise a single genetic stock, although gene flow appears to be greater among coastal samples than between coastal and offshore samples. [ABSTRACT FROM AUTHOR]

Salsola tragus L. (Russian thistle, Chenopodiaceae), a weed of Central Asian origin, has two biotypes in California, type A and type B. The gall midge Desertovellum stackelbergi Mamaev (Diptera: Cecidomyiidae), which attacks S. tragus in Uzbekistan, is a candidate biological control agent for this weed in the United States. In a field test conducted in Uzbekistan with plants of the two biotypes of S. tragus from California, both biotypes were attacked by the insect, although type A was the preferred host. Accessions of S. tragus from Uzbekistan, Greece, and Ukraine were similar to the California type A when compared using RAPD and ISSR analyses, while California type B was distinct. Since both California biotypes were hosts to the gall midge, further studies on the biology and host specificity of the insect are justified. Genetic characterization of target weeds can provide information useful for the selection of natural enemies. [Copyright &y& Elsevier]

Spatiotemporal genetic substructurings were investigated in the American beech population of the east-central coastal plain in Maryland. All trees including seedlings, various sizes of juveniles, and mature trees within the study site (10 × 100 m) were mapped, diameters measured, and leaves collected for allozyme analyses. Eleven polymorphic loci in eight enzyme systems were examined: 6Pgdh2, 6Pgdh3, Acp2, Adh1, Adh2, Fum, Got1, Got3, Lap, Pgi, and Pgm2. A total of 1945 trees were analyzed and 595 multilocus genotypes were detected. Six size-classes and 10 spatial blocks were discriminated for spatiotemporal analyses. Parameters for genetic variations (heterozygosity, Simpson's index, Shannon-Weaver's index, and inbreeding coefficient) decreased in larger size-classes. These genetic parameters fluctuated in spatial blocks of 10 m intervals, in which certain alleles were characteristic of specific blocks. The spatial autocorrelation by Moran's I and coancestry revealed the ranges of genetic relatedness to be only 20–30 m. Multilocus genotype analyses showed that higher genetic variations occur in larger size-classes and at gap openings where seed shadows for mother trees are overlapped. The relationships among reproductive trees, seedlings and juveniles suggested that the seed dispersal range of the American beech is normally in the range of 30–40 m. The mechanisms of a remarkably high genetic polymorphism maintained in this once artificially disturbed and grazed forest are discussed as related to conservation biology. [ABSTRACT FROM AUTHOR]

Compares the genetic diversity estimated from allozyme and from random amplified polymorphic DNA (RAPD) in a sample of 210 Great Basin bristlecone pines from three groves in White Mountains, California. Limitations of RAPD; Factors that may have enabled the pines to maintain a level of genetic diversity; Pros and cons of the results from allozymes and RAPD for population genetic studies in bristlecone pine.

Background: Individuals with Barrett's esophagus, in which the normal squamous esophageal epithelium is replaced with a columnar mucosa, are at increased risk for esophageal adenocarcinoma. Mucosal injury may be involved in the progression to neoplasia via the synthesis of prostaglandins and other mediators of inflammation. Cyclooxygenase (COX)-2 is the rate-limiting enzyme involved in prostaglandin synthesis. We examined the effect of inhibiting COX-2 activity in Barrett's esophageal cells.Methods: Primary esophageal epithelial and fibroblast cell cultures were established from endoscopic biopsy specimens from 20 consecutive patients with Barrett's esophagus. COX-2 expression and activity were determined on pooled cell cultures by reverse transcription-polymerase chain reaction and prostaglandin E(2) (PGE(2)) enzyme immunoassay, respectively. Proliferation was measured by Ki-67 staining. PGE(2) levels were determined in supernatants from epithelial cells treated with the selective COX-2 inhibitor NS-398, proinflammatory cytokines (interleukin 1beta and tumor necrosis factor-alpha), and conditioned medium from fibroblast cultures (both unstimulated and stimulated with proinflammatory cytokines).Results: Esophageal epithelial cells and fibroblasts expressed COX-2 messenger RNA. Compared with control-treated cells, NS-398 decreased proliferation of Barrett's esophageal epithelial cells by 55% (95% confidence interval = 47.1% to 63.8%; P<.001) and decreased COX-2 activity. The addition of exogenous PGE(2) reversed the antiproliferative effect of NS-398 on Barrett's esophageal epithelial cells. Proinflammatory cytokines did not affect COX-2 activity in esophageal epithelial cells but stimulated COX-2 activity in fibroblasts. However, conditioned medium from unstimulated and stimulated fibroblasts increased COX-2 activity in esophageal epithelial cells.Conclusion: COX-2 is functionally active in Barrett's esophagus because treatment with the COX-2 inhibitor hinders proliferation of Barrett's esophageal epithelial cells in culture, but proliferation is restored by treatment with prostaglandin. These results raise the possibility that inhibition of COX-2 may have chemopreventive potential for Barrett's esophagus. [ABSTRACT FROM AUTHOR]

More than 71,000 relatives of type 1 diabetic patients have been screened for cytoplasmic islet cell antibodies (ICAs), GAD65 autoantibodies (GAAs), and ICA512 autoantibodies (ICA512AAs). Among those 71,148 relatives, 2,448 were cytoplasmic ICA+, and the remainder were ICA-. Of the ICA+ group, 1,229 (50.2%) were positive for GAAs and/or ICA512AAs. Among ICA- relatives, 1,897 (2.76%) were positive for GAAs and/or ICA512AAs. Given the large number of relatives positive for cytoplasmic ICA and negative for "biochemically" determined autoantibodies, and the converse, we analyzed the proportion of ICA+ relatives found eligible to participate in the intervention phase of Diabetes Prevention Trial-Type 1 (DPT-1). To be eligible for the parenteral insulin DPT-1 trial, a relative had to have first-phase insulin secretion below the 1st percentile of cut-points (for parents) or below the 10th percentile (for siblings and offspring). To be eligible for the oral insulin trial, a relative had to have first-phase insulin secretion above cut-points (>1st percentile for parents, >10th percentile for siblings/offspring) and be positive for anti-insulin autoantibodies. For both trials, DQB1*0602 was an exclusion criteria, cytoplasmic ICA positivity had to be confirmed, and an oral glucose tolerance test had to result in nondiabetic levels. Of 572 relatives found to be eligible for trial entry, 442 (77.3%) were positive for GAAs and/or ICA512AAs, although overall only 50.2% of ICA+ relatives were positive for GAAs and/or ICA512AAs. The positive predictive value for trial eligibility for ICA+ relatives with GAAs or ICA512AAs who completed staging was 51.0%. In contrast, only 11.9% of ICA+ but GAA- and ICA512AA- relatives were found to be eligible by DPT criteria for trial entry. Positivity for biochemically determined autoantibodies among cytoplasmic antibody-positive relatives is associated with eligibility for the DPT-1 study. [ABSTRACT FROM AUTHOR]

The London strain of rainbow trout (Oncorhynchus mykiss) was created by interbreeding three other strains of rainbow trout and therefore was expected to have higher levels of genetic variation than other strains of rainbow trout. We examined 129 London strain rainbow trout from Indiana by allozyme electrophoresis to assess levels of genetic variation and to examine the relationship between the London strain and other hatchery strains. When using the same loci to compare with other hatchery strains the London strain showed levels of genetic variation within the range of other hatchery strains: mean heterozygosity of 0.053 (0.031–0.099), 1.27 (1.20–1.60) alleles per locus and 20.0% (20.0–40.0%) of the loci were polymorphic. The London strain is somewhat distinct from other hatchery strains (D=0.009–0.072), in part because of the high frequency of the sIDHP*40 allele. [ABSTRACT FROM AUTHOR]

AbstractEggs were sampled from 22 wild American alligator nests from the Rockefeller Wildlife Refuge in south-west Louisiana, along with the females guarding the nests. Three nests were sampled in 1995 and 19 were sampled in 1997. Females and offspring from all clutches were genotyped using five polymorphic microsatellite loci and the three nests from 1995 were also genotyped using one allozyme locus. Genotypes of the hatchlings were consistent with the guarding females being the mothers of their respective clutches. Multiple paternity was found in seven of the 22 clutches with one being fathered by three males, and the remaining six clutches having genotypes consistent with two males per clutch. Paternal contributions of multiply sired clutches were skewed. Some males sired hatchlings of more than one of the 22 clutches either as one of two sires of a multiple paternity clutch, as the sole sire of two different clutches, or as the sole sire of one clutch and one of two sires of a multiply sired clutch. There was no significant difference between females that had multiple paternity clutches and those that had singly sired clutches with respect to female total length (P = 0.844) and clutch size (P = 0.861). Also, there was no significant correlation between genetic relatedness of nesting females and pairwise nest distances (r2 = 0.003, F1,208 = 0.623, P = 0.431), indicating that females in this sample that nested close to one another were no more related than any two nesting females chosen at random. Eleven mutations were detected among hatchlings at the five loci over the 22 clutches. Most of these mutations (eight of 11) occurred at Amiµ-17, the only compound microsatellite locus of the five used in this study, corresponding to a mutation rate of 1.7 × 10-3. Finally, most of the mutations (82%) were homoplasious, i.e., mutating to an allelic state already present in this Louisiana population. [ABSTRACT FROM AUTHOR]

This study provides empirical information on intrapopulation gene dispersal via pollen, the size of genetic ‘neighbourhoods’, and interpopulation gene flow in a long-lived conifer, limber pine (Pinus flexilis). We used allozyme loci for a paternity analysis of 518 seeds produced in an isolated population of limber pine located in north-eastern Colorado, U.S.A., separated by 2 km from the nearest conspecific trees and nearly 100 km from populations in the Rocky Mountains. We also used indirect techniques (F[sub ST] analyses) to estimate gene flow rates among subdivisions of the study population and among five widely separated populations. Within the main study population limber pine exhibited a polymorphism level of 50%, observed heterozygosity of 0.159, and 2.36 alleles per polymorphic locus. Mountain populations were slightly more variable. The main study population showed significant differentiation in allozymes among neighbouring subpopulations. The mean F[sub ST] was 0.031 and the gene flow rate among subpopulations was estimated as 7.8 migrants per generation. Among widely separated populations the mean F[sub ST] was 0.035 and the gene flow rate was estimated as 6.9 migrants per generation. The paternity analysis indicated a best estimate of 6.5% pollen immigration (minimum 1.1%) from populations 2 km to 100+ km away. For 4% of the seeds examined, paternity could be ascribed to a single tree in the study population. Fractional paternity and likelihood methods were used to estimate pollen dispersal distances for the remainder of the seeds. Mean pollen dispersal distance was estimated at 140 m using the fractional method, similar to results from the other techniques. This compares with a mean distance of 172 m between potential mates. These results suggest near-panmictic pollen dispersal over this population, which covers about 15 ha. The observed allozyme differences and surprisingly low estimates of among-subpopulation gene flow are ascr... [ABSTRACT FROM AUTHOR]

The banded garden spider (Argiope trifasciata) is a common orb weaver of old field habitats in the United States. In this study, we determined levels of genetic variability and gene flow among seven populations in central Pennsylvania, based on variation at eight allozyme loci. Mean heterozygosity (observed) per population was 7.5% and mean polymorphism was 39.3%, consistent with levels of variability in other arthropods. Values of GST for the four polymorphic loci (mean GST=0.011) suggest that gene flow prevents the genetic differentiation of these populations. The average number of migrants per generation (Nm) among these populations is estimated to be 31.3. The lack of significant interpopulation genetic differentiation among these disjunct populations may result from spiderling aerial dispersal (ballooning), a more continuous distribution of suitable habitat in the past, and perhaps the use of roadside vegetation as gene flow corridors. On the other hand, the study populations did not exhibit isolation-by-distance, suggesting that suitable habitat in our study area is experienced as less than continuous by A. trifasciata. Thus, although A. trifasciata is an excellent ballooner, ballooning does not confer unlimited access among all populations, which suggests that ballooning may be a far less effective means of long-distance dispersal than previously thought. [ABSTRACT FROM AUTHOR]

A previous study of gene flow in Heterandria formosa, the least killifish, suggested that populations on the Florida peninsula may be close to equilibrium for migration and genetic drift, but the high average value of Nem calls that conclusion into question. In this study I examine patterns of gene flow at a fine scale within the St. Johns River drainage to test the predictions that (i) Nem within a drainage should be equal or greater than that among drainages, and (ii) gene flow within a drainage should approximate a one-dimensional stepping-stone system at equilibrium. I used four isozyme systems (six loci) that were polymorphic in the previous study to characterize population structure and gene flow. Nem within each river was equal to or greater than the average value reported in the previous study, which strengthens the equilibrium interpretation of the species-wide results. However, the results showed no isolation by distance within two forks of the St. Johns drainage (the upper St. Johns and the Ocklawaha rivers), but significant differentiation between the two forks. This result has two implications: (i) that populations within each river are not at equilibrium; and (ii) that there was a historical barrier to migration between the two forks. There were substantial differences among loci, but an (appropriate) application of Lewontin and Krakauer's test revealed no evidence that locus-specific forces led to a violation of the assumption of neutrality. [ABSTRACT FROM AUTHOR]

Decimation of the California (U.S.A.) prairie has increased interest in the conservation and ecological restoration of grasslands composed of native perennial species. Widespread plantings are being attempted, and the potential for contaminating existing remnant populations with maladapted germplasm has led to concerns about the use of nonlocal seed sources. We evaluated regional patterns of isozyme and quantitative trait variation in the native perennial grass Nassella pulchra for the purpose of developing recommendations about the spatial scales over which seed can be translocated. Seed was collected from 10 remnant native populations. Progeny from all 10 populations were scored for isozyme variation with 11 stains, and progeny from 8 populations were planted in a common garden to evaluate variation for 11 quantitative (polygenic) traits. The correspondence between isozyme and quantitative trait variation and the relationships of both types of variation to geographic distance and climate were explored by Mantel test regressions. Populations were strongly differentiated for both isozymes and quantitative traits, but cluster analysis based on each type of data did not result in the same population groupings. This lack of congruence was further demonstrated by the nonsignificance of the regression of Hedrick's distances for isozymes on Mahalanobis distances for quantitative traits. Quantitative trait variation was strongly associated with climatic variables, whereas isozyme variation was not. This suggests that the relative importance of genetic drift and selection in shaping patterns of genetic differentiation may depend upon the type of trait evaluated. Quantitative traits are potentially better indicators of adaptation to regional and local environmental variation, and thus the usefulness of isozymes for making recommendations about the spatial scales over which seed of N. pulchra can be translocated may be limited. Unfortunately, obtaining data on patterns of quantitative trait variation is often time‐ and labor‐intensive. The close association of quantitative trait variation with regional climatic variables indicates that an index based on readily obtainable climatic information might aid restorationists in making rapid decisions about appropriate spatial scales for translocating native grasses. Compariciones de Isozimas y Rasgos Cuantitativos para Evaluar Patrones de Variación Genética en el Pasto‐Aguja Morado (Nasella pulchra) La disminución de la pradera de California (USA) ha incrementado el interés en la conservación y restauración ecológica de pastizales compuestos por especies perennes nativas. La dispersión amplia de siembras se ha intentado y el potencial de contaminación de poblaciones remanentes con germoplasmas mal adaptados ha generado preocupaciones sobre el uso de fuentes de semilla no locales. Evaluamos patrones regionales de variación de isozimas y variación cuantitativa de rasgos en el pasto perenne nativo Nasella pulchra con el propósito de desarrollar recomendaciones sobre las escalas espaciales en las cuales las semillas pueden ser movidas. Las semillas fueron colectadas a partir de 10 poblaciones remanentes nativas. Las progenies de las 10 poblaciones fueron evaluados para variación de isozima usando 11 colorantes y las progenies de 8 poblaciones fueron plantadas en un jardín común para evaluar la variación de 11 rasgos (poligenéticos) cuantitativos. La correspondencia entre variaciones de isozimas y de rasgos cuantitativos y las relaciones de ambos tipos de variación con distancia geográfica y clima fue explorada usando pruebas de regresión de Mantel. Sin embargo, los análisis de conjunto basados en cada tipo de datos no dió como resultado las mismas agrupaciones de poblaciones. Esta carencia de congruencia fue demonstrada más adelante por la no significancia de la regresión de distancias de Hendrick para isozimas en distancias Mahalanobis para rasgos cuantitativos. La variación en rasgos cuantitativos estuvo fuertemente asociada con las variables climáticas, mientras que la variación de isozimas no lo estuvo. Esto sugiere que la importancia relativa de la deriva génica y de la selección en patrones de forma de diferenciación genética pueden depender del tipo de rasgo evaluado. Los rasgos cuantitativos son potencialmente mejores indicadores de adaptación a la variación ambiental local y regional, por lo tanto la utildad de isozimas para hacer recomendaciones sobre escalas espaciales en las cuales las semillas de N. pulchra pueden ser movidas puede verse limitada. Desafortunadamente, la obtención de datos de patrones de variación de rasgos cuantitativos require frecuentemente de tiempo y esfuerzo intensivos. La asociación cercana de variación de rasgos cuantitativos con variables climáticas regionales indica que un indice basado en información climática accesible podría ayudar a los restauradores a tomar decisiones rápidas sobre escalas espaciales apropiadas para mover pastos nativos. [ABSTRACT FROM AUTHOR]

Provides information on a study which examined patterns of variation in skeletal morphometrics, allozymes and mitochondrial DNA restriction sites among species of Toxostoma in the United States. Methodology of the study; Results and discussions of the study; Conclusions.

AbstractThe effective population sizes (Ne) of six populations of the long-toed salamander (Ambystoma macrodactylum) from Montana and Idaho, USA were estimated from allozyme data from samples collected in 1978, 1996 and 1997 using the temporal allele frequency method. Five of the six estimates ranged from 23 to 207 (mean = 123 ± 79); one estimate was indistinguishable from infinity. In order to infer the actual Ne of salamander populations, we compared the frequency distribution of our observed Ne estimates with distributions obtained from simulated populations of known Ne. Our observed Ne estimate distribution was consistent with distributions from simulated populations with Ne values of 10, 25, and 50, suggesting an actual Ne for each of the six salamander populations of less than 100. This Ne estimate agrees with most other Ne estimates for amphibians. We conclude by discussing the conservation implications of small Ne values in amphibians in the context of increasing isolation of populations due to habitat fragmentation. [ABSTRACT FROM AUTHOR]

Understanding of the formation and biological actions of nitric oxide (NO) has grown extensively during the past 2 decades. Through our discoveries of the biological effects of NO and nitrovasodilators on cyclic guanosine monophosphate (GMP) and our discoveries of the biochemical mechanisms of NO and regulation of NO synthase in numerous cell types and tissues, the complexity of the signal transduction cascade and the extensive function-regulating interactions of the NO molecule have been increasingly demonstrated. Although the diverse roles of this unique molecule continue to unfold, NO can be recognized as an intracellular second messenger, a local substance for regulation of neighboring cells, a neurotransmitter in central and peripheral neurons, and perhaps a hormone that can act at distant sites and has been shown to have beneficial or deleterious biological effects, depending on its concentration, the system, and the cellular environment. [ABSTRACT FROM AUTHOR]

Presents a study which examines the adaptive radiations of flora and fauna in the Hawaiian Islands. References to related studies; Occurrence of allozyme diversity; Research methodology; Results; Discussion.

Vertidillium albo-atrium isolated from alfalfa (lucerne) (Medicago saliva) growing at high air temperatures in southern California desert regions was compared with isolates from cooler, more favourable climates in Europe and the northern USA by determination of colony morphology, temperature effects on radial growth on agar, virulence on a resistant (NK-89786) and susceptible (Moapa-69) alfalfa cultivar, and by isozyme eletrophoresis. Isolates from Europe, non hem USA and southern California produced different colony morphologies on lactose yeast prune agar. Southern California isolates incubated at 30°C on agar produced significantly (F = 0.05) greater colony diameters than isolates from northern USA and Europe after 20 days. The virulence of isolates from southern California and northern USA was equally severe on alfalfa, while the virulence of European isolates was comparatively less severe. Alfalfa isolates of V. albo-atrum from southern California had similar isozyme banding patterns to alfalfa isolates from Europe and northern USA. suggesting a common origin. However, differences in morphology, virulence and temperature relations indicate that isolates may have adapted to local environmental conditions. V. albo-atrum from southern California was tested for its persistence in alfalfa debris at high temperatures over time, and for its ability to infect other crops and weeds. The fungus persisted over a 32-month period in baled alfalfa hay exposed to air temperatures as high as 40°C during the summer months. Alfalfa stem pieces infected with V. albo-atrum were buried in sterile soil or in non-sterile field soil, or held without soil and incubated at 20. 24, 30, 35 and 41°C. Regrowth continued for up to 16 months at 30°C and for 3 months at 35°C from a small percentage of stem pieces buried in field soil. Regrowth continued for up to 16 months at 41°C from a small percentage of stems stored without soil V. a!bo-atrum was reisolated from all nine inoculated weed species, with three of these exhibiting foliar symptoms of Verticillium wilt. Ten of the inoculated crop species harboured V. albo-atrum and four showed symptoms. [ABSTRACT FROM AUTHOR]

Enzyme electrophoresis was used to measure genetic variation in five populations of the rare diploid species Coreopsis Iatifolia which appears to be a relict taxon endemic to a small area of the southeastern United States. Gene diversity within the species as a whole is low compared to other species with similar ecological and life history traits. Also, gene diversity in C. latifolia is lower than nearly all other species of Coreopsis that have been examined. Larger populations contain significantly more variation at isozymc loci than do smaller populations. Populations of C. latifolia are deficient in heterozygotes relative to expected equilibrium values. [ABSTRACT FROM AUTHOR]

Buffalograss, Buchloe dactyloides, is widely distributed throughout the Great Plains of North America, where it is an important species for rangeland forage and soil conservation. The species consists of two widespread polyploid races, with narrowly endemic diploid populations known from two regions: central Mexico and Gulf Coast Texas. We describe and compare the patterns of allozyme and RAF'D variation in the two diploid races, using a set of 48 individuals from Texas and Mexico (four population samples of 12 individuals each). Twelve of 22 allozyme loci were polymorphic, exhibiting 35 alleles,while seven 10-mer RAPD primers revealed 98 polymorphic bands. Strong regional differences were detected in the extent of allozyme polymorphism: Mexican populations exhibited more internal gene diversity (He= 0.20,0.19) than did the Texan populations (He= 0.08,0.06), although the number of RAPD bands in Texas (n = 62) was only marginally smaller than in Mexico (n = 68). F-statistics for the allozyme data, averaged over loci, revealed strong regional differentiation (mean F, = + 0.301, as well as some differentiationamong populations within regions (mean F, = + 0.09). In order to describe andcompare the partitioning of genetic variation for multiple allozyme and RAPD loci, we performed an Analysis of Molecular Variance (AMOVAA)M. OVAfo r both allozyme and RAPD data revealed similar qualitative patterns: large regional differences and smaller (but significant) population differences within regions. RAPDs revealed greater variation among regions (58.4% of total variance) than allozymes (45.2%), but less variation among individuals within populations (31.9% forRAPDsvs.45.2% forallozymes); the proportionof genetic variance among populations within regions was similar (9.7% for RAPDs vs. 9.6% forallozymes). Despite thislarge-scaleconcordance of allozyme and RAF'D variation patterns, multiple correlation Mantel techniques revealed that the correlations were low on an individual by individual basis. Our findings of strong regional differences among the diploid races will facilitate further study of polyploid evolution in buffalograss. [ABSTRACT FROM AUTHOR]

Copyright of Weed Research is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Presents a study that focused on the clinical implications of herbal medicines and conventional prescribed medications in the U.S. for the treatment of cancer. Analysis of the interaction of herbal medicines with anti-cancer agents; Role of cytochrome isoenzymes in the metabolism of antineoplastic agents; Flaws of the research.

Presents the outcome of patients diagnosed with esophageal adenocarcinoma in the U.S. Occurrence in the setting of Barret's esophagus; Increase of risk for developing esophageal adenocarcinoma; Implications of the treatment with COX-2 inhibitors.

Drug tolerability strongly influences patients' persistence with treatment. In this study, patterns of medication persistence with cyclooxygenase 2 (COX-2)-specific inhibitors and nonspecific nonsteroidal anti-inflammatory drugs (NSAIDs) were compared in a managed care setting. Pharmacy, enrollment, and medical claims data from 19 health plans were used to match subjects newly treated with celecoxib, rofecoxib, ibuprofen, naproxen, or diclofenac between July 1, 1999 and June 30, 2000. By using multiple regression analysis, users of COX-2-specific inhibitors were found to be 56.8% less likely to discontinue medication use and 60.3% less likely to switch treatment than were users of nonspecific NSAIDs (P < .001). Celecoxib users were 4.6% less likely to discontinue treatment than were rofecoxib users (P < .001). The greater persistence observed among users of COX-2 inhibitors might reflect improved treatment efficacy and patient satisfaction.