Synthesis of a new element with atomic number Z = 117.

The discovery of a new chemical element with atomic number Z=117 is reported. The isotopes (293)117 and (294)117 were produced in fusion reactions between (48)Ca and (249)Bk. Decay chains involving 11 new nuclei were identified by means of the Dubna gas-filled recoil separator. The measured decay properties show a strong rise of stability for heavier isotopes with Z > or = 111, validating the concept of the long sought island of enhanced stability for superheavy nuclei.

Lightest isotope of Bh produced via the 209Bi(52Cr,n)260Bh reaction.

The lightest isotope of Bh was produced in the new 209Bi(52Cr,n)260Bh reaction at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. Positive identification was made by observation of eight correlated alpha particle decay chains in the focal plane detector of the Berkeley Gas-Filled Separator. 260Bh decays with a 35(-9)(+19) ms half-life by alpha particle emission mainly by a group at 10.16 MeV. The measured cross section of 59(-20)(+29) pb is compared to model predictions. The influence of the N=152 and Z=108 shells on alpha decay properties is discussed.

Removal of 2,4-dinitrotoluene from concrete using bioremediation, agar extraction, and photocatalysis.

Three methods, i.e. bioremediation by application of bacteria-laden agar, physical absorption of DNT by agar, or illumination by UV light were evaluated for the removal of 2,4-dinitrotoluene (DNT) from building-grade concrete. DNT biodegradation by Pseudomonas putida TOD was turned "on" and "off" by using toluene as a co-substrate thus allowing for rate-limiting step assessment. Bioremediation efficiency can be > 95-97% in 5-7 d if the process occurs at optimum growth temperature with the biological processes appearing to be rate-limiting. Sterile agar can remove up to 80% of DNT from concrete thus allowing DNT desorption and biodegradation to be conducted separately. Photoremediation results in 50% DNT removal in 9-12 d with no further removal, most likely due to mass transfer limitations.

Prevalence of gastric lesions in racing Alaskan sled dogs.

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.

Efficacy of omeprazole for the prevention of exercise-induced gastritis in racing Alaskan sled dogs.

Exercise-induced gastritis and gastric ulcers are common in humans and horses, and recently have been described in racing sled dogs. The cause of exercise-induced gastric disease is not completely understood in any species, but pharmacologic suppression of acid secretion is an effective treatment in humans and horses. Thus, we tested the hypothesis that omeprazole, a proton-pump inhibitor shown to reduce gastric acid secretion in dogs, would reduce the severity of exercise-induced gastric disease. Three teams of 16 dogs each competing in the 2002 Iditarod Sled Dog Race were recruited for participation. Within each team, dogs were randomly assigned to either treatment (20 mg omeprazole PO q24h) or placebo. Treatments were administered until either completion of the race or withdrawal of an individual dog from competition. Gastric endoscopy was performed in all dogs 24 hours after completion or withdrawal, and the gastric mucosa was scored by using a subjective severity score (0 = normal, 3 = numerous bleeding ulcers). Treatment with omeprazole significantly reduced mean gastric severity score compared to placebo (omeprazole: 0.65 +/- 0.17, placebo: 1.09 +/- 0.18; P = .028), but also was associated with increased frequency of diarrhea during the race (omeprazole 54%, placebo 21%; P = .017). Examination of our data suggests that omeprazole may be an effective treatment for exercise-induced gastric disease in racing sled dogs. However, further investigation regarding the cause and clinical relevance of diarrhea associated with omeprazole treatment must be conducted before omeprazole can be recommended for routine prophylactic treatment in these athletes.

Association between vitamin E and enhanced athletic performance in sled dogs.

PURPOSE: To determine the association between prerace plasma vitamin E concentration and performance in sled dogs competing in the 1998 Iditarod Race. METHODS: Prerace blood samples were collected from 670 dogs. Samples were analyzed for plasma vitamin E concentration while controlling for selected hematological and biochemical variables and signalment. Starting in teams of 16, exercise consisted of running up to 1159 miles pulling a laden sled and musher via checkpoints. The records of dogs that were withdrawn from the race for health reasons, fatigue, or strategic or technical reasons, and those of dogs that finished the race were analyzed. Multiple logistic regression and Cox proportional hazards analysis were used to determine factors associated with endurance. Multiple linear regression analysis was used to determine factors associated with team speed. RESULTS: A total of 323 dogs (48%) were withdrawn from racing at various distances from the start. Median time to finish for 39 teams was 11.5 d and the winning time was 9.2 d. Dogs with prerace plasma vitamin E concentrations > 40.7 microg.mL-1 were 1.9 times more likely to finish (P = 0.0006) and had 1.8 times less of a risk of being withdrawn for every mile ran (P = 0.03) than were dogs with plasma vitamin E concentrations between 16.3 and 40.7 microg.mL-1. Neither a team's mean prerace vitamin E concentration, nor the proportion of dogs within a team with high (> 40.7 microg.mL-1) vitamin E concentration was associated with team speed. CONCLUSIONS: Dogs with higher plasma vitamin E concentrations have enhanced endurance compared with dogs with lower plasma vitamin E concentrations, but the plasma vitamin E status of a team is not associated with team speed.

Vitamin E and exertional rhabdomyolysis during endurance sled dog racing.

Exertional rhabdomyolysis (ER) is common in sled dogs, animals with high energy expenditures that consume high fat (60% of ingested calories) diets. Associations between pre-race plasma [vitamin E] and total antioxidant status (TAS) and risk of developing ER were examined in dogs competing in the 1998 Iditarod race. Pre-race blood samples were collected from 750 dogs and a second sample was collected from 158 dogs withdrawn from the race at various times. Plasma creatine kinase activity was used to identify withdrawn dogs with ER. There was no association between pre-race plasma [vitamin E] and risk of development of ER. Dogs that developed ER started the race with higher TAS, but when withdrawn, had lower TAS than unaffected dogs and had similar pre-race [vitamin E] but higher [vitamin E] at time of withdrawal. Hence, the risk of ER in sled dogs is not affected by plasma [vitamin E] before the race.

PU.1 is a lineage-specific regulator of tyrosine phosphatase CD45.

The hematopoietic cell-specific ets family transcription factor PU.1 regulates many lymphoid and myeloid genes. We have determined that PU.1 is critical for lineage-specific expression of the tyrosine phosphatase CD45. CD45 is expressed exclusively in hematopoietic cells at all stages of development, except for mature red cells and platelets. Although CD45 is normally expressed in all leukocyte lineages, it is critically regulated by PU.1 only in myeloid cells. Whereas myeloid cells from PU.1 null mice failed to express CD45, lymphoid cells were CD45(+) by flow cytometry. Additionally, mRNA for CD45 was absent from PU.1-deficient myeloid cells. To understand the molecular basis for these observations, we characterized a transcriptional regulatory region of the murine CD45 gene containing exons 1a, 1b, and 2. Distinct transcriptional initiation sites for CD45 were demonstrated in T and B cells versus myeloid cells. A transcriptional initiation site in exon 1b (P1b) was principally utilized by myeloid cells. A PU.1 binding site was identified upstream of exon 1b by sequence analysis and DNA binding assays. Using this region of the CD45 locus we demonstrated that PU.1 directly transactivated reporter gene expression. Finally, retrovirus-mediated restoration of PU.1 expression to PU.1-deficient myeloid cells resulted in expression of cell surface CD45 and restored phosphatase activity, confirming the role of PU.1 in the positive regulation of this well known signaling molecule. We conclude that CD45 is regulated differentially in myeloid and lymphoid cells and that sequences critical to direct myeloid expression include a PU.1 binding site upstream of the P1b transcriptional initiation site.

Synergistic induction of the Tap-1 gene by IFN-gamma and lipopolysaccharide in macrophages is regulated by STAT1.

Proper regulation of the Tap-1 gene is critical for the initiation and continuation of a cellular immune response. Analysis of the Tap-1/low molecular mass polypeptide 2 bidirectional promoter showed that the IFN-gamma activation site element is critical for the rapid induction of the promoter by IFN-gamma following transfection into the human macrophage cell line THP-1. Furthermore, activation of STAT1 binding to this site was important for the synergistic response seen following the stimulation with both IFN-gamma and LPS. Mutation of an IFN-stimulated regulatory element that binds IFN regulatory factor 1 appeared to enhance the response to IFN-gamma and LPS. These data show that STAT1 is necessary for the activation of Tap-1 gene expression in APCs and initiation of cellular immune responses. Furthermore, our data suggest that bacterial products such as LPS may enhance cellular immune responses through augmenting the ability of STAT1 to regulate IFN-gamma-inducible genes.

Response of pigs to bitter-tasting compounds.

Two-bottle preference tests were done to determine whether pigs detect bitter-tasting compounds. Four standard bitter compounds and nine bitter-tasting pharmaceutical compounds were tested. Pigs detect and avoid taste compounds that humans perceive as bitter-tasting. A dose-response to varying concentrations of bitter tastants can be measured.

Clonal analysis of delayed karyotypic abnormalities and gene mutations in radiation-induced genetic instability.

Many tumors exhibit extensive chromosomal instability, but karyotypic alterations will be significant in carcinogenesis only by influencing specific oncogenes or tumor suppressor loci within the affected chromosomal segments. In this investigation, the specificity of chromosomal rearrangements attributable to radiation-induced genomic instability is detailed, and a qualitative and quantitative correspondence with mutagenesis is demonstrated. Chromosomal abnormalities preferentially occurred near the site of prior rearrangements, resulting in complex abnormalities, or near the centromere, resulting in deletion or translocation of the entire chromosome arm, but no case of an interstitial chromosomal deletion was observed. Evidence for chromosomal instability in the progeny of irradiated cells also included clonal karyotypic heterogeneity. The persistence of instability was demonstrated for at least 80 generations by elevated mutation rates at the heterozygous, autosomal marker locus tk. Among those TK- mutants that showed a loss of heterozygosity, a statistically significant increase in mutation rate was observed only for those in which the loss of heterozygosity encompasses the telomeric region. This mutational specificity corresponds with the prevalence of terminal deletions, additions, and translocations, and the absence of interstitial deletions, in karyotypic analysis. Surprisingly, the elevated rate of TK- mutations is also partially attributable to intragenic base substitutions and small deletions, and DNA sequence analysis of some of these mutations is presented. Complex chromosomal abnormalities appear to be the most significant indicators of a high rate of persistent genetic instability which correlates with increased rates of both intragenic and chromosomal-scale mutations at tk.

Ionizing radiation signature mutations in human cell mutants induced by low-dose exposures.

Investigation of mutational specificity at low doses has generally not been possible since the number of induced mutants may be similar or significantly lower than the spontaneous background. The use of a low-dose fractionated exposure protocol in TK6 human lymphoblasts results in an incremental accumulation of mutants induced by individual 20 cGy gamma-ray exposures. Therefore, the frequency of induced mutants within a population at the conclusion of a fractionated exposure regimen is sufficiently elevated to permit the recovery of a low-dose mutant collection. Statistical analysis of the data identified no significant differences between mutants induced by 20 or 200 cGy. However, deletions encompassing one or more Xq26 STS markers flanking the hprt locus represented only 1/107 (0.009) spontaneous HPRT- mutants but 34/170 (0.20) mutants induced by 20 or 200 cGy of ionizing radiation (P < 0.0001). The data presented here demonstrate that mutational fingerprints can be effectively defined using deletion mapping for clastogens such as ionizing radiation, and that the radiation-induced mutational spectrum is independent of dose.

Cutaneous melanocytomas in 10 young cattle.

Ten melanocytomas from 10 cattle were diagnosed by histopathologic examination of biopsy specimens submitted to the Veterinary Medical Diagnostic Laboratory, University of Missouri, between 1 January 1986 and 31 December 1993. One tumor was congenital; the others were first noticed between 2 months and 2 years of age (means = 9.9 months). Six tumors occurred in purebred (3) or crossbred (3) Angus cattle; one tumor each occurred in a Holstein, a Shorthorn, a Simmental, and a beef calf of unrecorded breed or coat color. Five calves were female, and five were male. Five tumors occurred in truncal dermis or subcutis (three in abdominal skin), four occurred on a limb, and one occurred on the jaw. Tumors varied in histologic appearance, but all were pigmented and all had few mitotic figures. Outcome was known for 8/10 cattle. In four cattle followed for at least 1 year, the tumor did not recur after surgical excision. Another heifer had residual gray tissue at the tumor site after surgery but remained in the herd without regrowth of the tumor 30 months after excision. Three other calves were slaughtered within 6 months of excision without apparent recurrence of the tumor.

A comparison of topical ketorolac, systemic flurbiprofen, and placebo for the inhibition of bone loss in adult periodontitis.

Systemic non-steroidal anti-inflammatory drugs (NSAIDs) have been shown to reduce alveolar bone loss in periodontitis. This study assesses the efficacy of a topical NSAID rinse, containing ketorolac tromethamine as the active agent. Adult periodontitis patients (n = 55) were studied in this 6-month randomized, double blind, parallel, placebo and positive-controlled study. Each patient had a least 3 sites at high risk for bone loss as assessed by low dose bone scan. Groups, balanced for gender, were assigned to one of three regimens: bid ketorolac rinse (0.1%) with placebo capsule; 50 mg bid flurbiprofen capsule (positive control) with placebo rinse; or bid placebo rinse and capsule. Prophylaxes were provided every 3 months. Monthly examinations assessed safety, gingival condition, and gingival crevicular fluid PGE2. Standardized radiographs were taken at baseline and at 3 and 6 months for digital subtraction radiography. A significant loss in bone height was observed during the study period in the placebo group (-0.63 +/- 0.11; P < 0.001), but not in the flurbiprofen (-0.10 +/- 0.12; P = 0.40) or ketorolac rinse (+0.20 +/- 0.11 mm; P = 0.07) groups. Nested ANOVA revealed that ketorolac and flurbiprofen groups had less bone loss (P < 0.01) and reduced gingival crevicular fluid PGE2 levels (P < 0.03) compared to placebo. ANOVA suggests (P = 0.06) that ketorolac rinse preserved more alveolar bone than systemic flurbiprofen at the dose regimens utilized. These data indicate that ketorolac rinse may be beneficial in the treatment of adult periodontitis.

Mutational spectrum of X-ray induced TK- human cell mutants.

Mutations induced by ionizing radiation have historically elicited significant public concern. However, only a limited database of ionizing radiation-induced point mutations is available, particularly at endogenous human cell loci. Here, we report the mutational spectrum for 184 X-ray induced TK- mutants derived from TK6 human lymphoblasts. This report represents the first large scale utilization of the tk locus for investigation of mutational specificity at the DNA sequence level. Rapid, single nucleotide sequencing assays at frameshift polymorphism sites in tk exons 4 and 7 were used to partition TK- mutants into two groups: 126 were attributed to either partial gene deletion or to loss of heterozygosity, and DNA sequence alterations were identified for 51. X-ray-induced point mutations included all classes of transitions and transversions, tandem base substitutions, frameshifts, small deletions and a small duplication. The distribution within tk was characterized by clustering at some sites. Twelve TK- point mutations, including five entirely within the coding sequence in exons 3 and 4, resulted in aberrant splicing of the tk transcript. The spectrum of X-ray-induced point mutations was found to be highly reproducible when TK- mutations were compared with HPRT- mutations in TK6. A statistically significant decrease in transitions (P = 0.04) was observed in the combined data set as compared to the spontaneous background. These findings suggest a reproducible pattern which may be utilized in recognizing radiation-induced mutations at other loci of interest.

Mapping the end points of large deletions affecting the hprt locus in human peripheral blood cells and cell lines.

We have examined the extent of HPRT- total gene deletions in three mutant collections: spontaneous and X-ray-induced deletions in TK6 human B lymphoblasts, and HPRT- deletions arising in vivo in T cells. A set of 13 Xq26 STS markers surrounding hprt and spanning approximately 3.3 Mb was used. Each marker used was observed to be missing in at least one of the hprt deletion mutants analyzed. The largest deletion observed encompassed at least 3 Mb. Nine deletions extended outside of the mapped region in the centromeric direction (> 1.7 Mb). In contrast, only two telomeric deletions extended to marker 342R (1.26 Mb), and both exhibited slowed or limited cell growth. These data suggest the existence of a gene, within the vicinity of 342R, which establishes the telomeric limit of recoverable deletions. Most (25/41) X-ray-induced total gene deletion mutants exhibited marker loss, but only 1/8 of the spontaneous deletions encompassed any Xq26 markers (P = 0.0187). Furthermore, nearly half (3/8) of the spontaneous 3' total deletion breakpoints were within 14 kb of the hprt coding sequence. In contrast, 40/41 X-ray-induced HPRT- total deletions extended beyond this point (P = 0.011). Although the overall representation of total gene deletions in the in vivo spectrum is low, 4/5 encompass Xq26 markers flanking hprt. This pattern differs significantly from spontaneous HPRT- large deletions occurring in vitro (P = 0.032) but resembles the spectrum of X-ray-induced deletions.

Applying crisis intervention methodology to the retention of students: a case study.

This article presents the application of crisis theory and the adaptation of Aguilera's crisis intervention model for use in the retention of four at-risk students. Knowledge of student learning styles/preferences along with prior knowledge of faculty teaching and testing styles facilitated the selection of appropriate learning strategies to guide these students to successful completion of a course, the subsequent successful completion of the nursing program and entry into professional practice.

Comparison of single-dose ibuprofen lysine, acetylsalicylic acid, and placebo for moderate-to-severe postoperative dental pain.

In a single-dose, double-blind, parallel-group, single-site study, ibuprofen lysine 200 mg (IBL 200) was compared with acetylsalicylic acid 500 mg (ASA 500) and placebo in 183 patients with moderate-to-severe postoperative dental pain. The relative onset of analgesic response, duration and degree of analgesia, and safety were assessed over a 6-hour postdose period. Analgesic efficacy was assessed by patient self-rating of pain intensity, pain relief, time to meaningful pain relief, global evaluation, and requirement for additional analgesic medication; both IBL 200 and ASA 500 were significantly more effective than placebo. IBL 200 also had a significantly faster onset of action, greater peak and overall analgesic effect, and longer duration of analgesia than ASA 500. All treatments were generally well tolerated.

Spectrum of X-ray-induced mutations in the human hprt gene.

We have characterized the molecular spectrum of mutations in 116 X-ray-induced and 78 spontaneous, HPRT- mutants derived from the human B lymphoblastoid cell line TK6. Multiplex PCR analysis demonstrated that the overall representation of large deletions was not significantly different in the two spectra. However, highly significant differences were observed for specific deletion types. Total gene deletions represented 41/78 (0.53) X-ray-induced, but only 7/43 (0.16) spontaneous deletions (P < 0.0001). In contrast, 5' terminal deletions were significantly more common among spontaneous (17/43, 0.40) than X-ray-induced (13/78, 0.17) large deletions (P = 0.0079). The types of point mutations induced by X-ray exposure were very diverse including all classes of transitions and transversions, tandem base substitutions, frameshifts, small deletions and a deletion/insertion compound mutation. Compared to spontaneous data, radiation-induced point mutations exhibited a reduced number of transitions and an increased representation of small deletions. Small deletions were uniformly surrounded by direct sequence repeats. The distribution of point mutations was characterized by a cluster within the 5' portion of exon 8. Thirteen HPRT- point mutations exhibited aberrant splicing. Four of these were attributable to coding sequence alterations in exons 4 and 8. These results suggest that it may be possible to identify hallmark mutations associated with X-ray exposure of human cells.