Immunotoxicity of explosives-contaminated soil before and after bioremediation.

Soils from the Yorktown Naval Base contaminated with trinitrotoluene (TNT) and other explosives were used to prepare eluates before and after bioremediation using microbial growth amendments in the presence (P1 eluates) or absence (P2 eluates) of exogenous white rot fungus. Effectiveness of bioremediation was examined by several immunotoxicity assays-viability/growth of lymphocytes, cytokine production, and expression of the interleukin-2 (IL-2) receptor-using human peripheral blood mononuclear cells exposed to the eluates. Although TNT concentrations decreased in both P1 and P2 eluates relative to untreated baseline soil (BL) eluates, a recovery in lymphocyte growth/viability and IL-2 secretion was seen with P2 but not P1 eluates relative to BL eluates. IL-2 receptor levels were higher in cells exposed to BL and P2 eluates than when exposed to P1 eluates. Interferon-gamma, tumor necrosis factor-beta, and IL-10 levels were highest in BL and P2 eluates and lowest in P1 eluates. Taken together, these results suggest that treatment of the soil with microbial growth amendments in the absence but not the presence of exogenous white rot fungi lead to partial bioremediation as assessed by lymphocyte functions.

Development of the College Student Reasons for Living Inventory.

Two studies were carried out in an effort to develop and evaluate an instrument designed to assess suicidal risk in college students. Study 1 describes the development of the College Student Reasons for Living Inventory (CSRLI), an instrument that measures the extent to which college students place importance on various reasons for living even when contemplating suicide. The impetus for the current study was provided by Linehan et al., who in 1983 developed the Reasons for Living Inventory for use with adults. In the current study college students generated a series of 84 "reasons for living" items, which were reduced through factor analysis to a final inventory of 46 items. Six factors were extracted as follows: Survival and Coping Beliefs, College and Future-Related Concerns, Moral Objections, Responsibility to Friends and Family, Fear of Suicide, and Fear of Social Disapproval. Five of these factors reflect the same basic themes contained in the Linehan et al. (1983) study. The sixth factor (College and Future-Related Concerns) appears to be unique to college students. Linehan et al.'s Child-Related Concerns factor expectedly did not appear in this college sample. In Study 2 initial evaluation of the CSRLI was carried out through the use of correlational, confirmatory factor, and discriminant analyses. Results indicate that the CSRLI holds promise as an instrument to predict suicidal risk among college students.

Genetic analysis of the anther-culture response of three spring wheat crosses.

Anther-culture response was examined among three spring wheat (Triticum aestivum L.) cultivars to evaluate the genetic component of response and to determine whether androgenetic performance could be improved by selection. The three lines, the three possible F1's among the three lines, their F2's, and the backcrosses to the parents were evaluated for callus production and regeneration capacity. Significant variation was observed among the generations of the three crosses for callus formation. Genetic variation for regenerability was nonsignificant. Callus production was negatively correlated (-0.24) with regeneration capacity. The random variation in the study was too great to determine whether major-gene differences for antherculture response exist among the three lines by examining population distributions. When the material was evaluated for quantitative gene effects, the estimates for the additive gene effects were generally greater than the estimates for the dominance gene effects for callus formation. Only the Pavon x Chris cross, however, exhibited a significant narrow sense heritability estimate for callusing response (0.94). Due to the large component of random variation and the varying selection potential among crosses for androgenetic performance, improving anther-culture response in wheat by selection could prove difficult unless the anther-culture process itself selects for response traits at the gametic level.

A comparison of burley tobacco doubled-haploid lines with their source inbred cultivars.

A doubled-haploid line was randomly derived from each of seven burley tobacco, Nicotiana tabacum L., cultivars using anther culture and leaf-midvein chromosomal doubling. The doubled-haploid lines were compared to their source inbred cultivars in two experiments for several agronomic and chemical characters. A consistent relationship between anther-derived materials and reduced vigor was not observed in these doubled-haploid lines. Significant differences between the doubled-haploid mean and their source cultivar mean were observed only for days to flower and total alkaloids. The doubled-haploid means were not significantly different from their source cultivar means for yield, plant height, and leaf number. In total, 26 of the 35 individual comparisons between a doubled-haploid line and its source cultivar were nonsignificant. Reciprocal crosses between the doubled-haploid lines and their source inbred cultivars also demonstrated no significant differences. The diallel progeny of the seven doubled-haploid lines showed a similar genetic performance to that of diallel progeny from conventional materials in previous studies. The differences observed between the doubled-haploid lines and their source inbred cultivars could be explained by residual heterozygosity. The performances of the doubled-haploid progeny could also be attributed to the presence of residual heterozygosity in the original cultivars. As tested by reciprocal crosses, cytoplasmic effects were not significantly involved in the performance of the double-dhaploid lines.

Expressed resistance to black shank among tobacco callus cultures.

Quantitatively inherited resistance to the black shank pathogen (Phytophthora parasitica var. 'nicotianae') was expressed among callus tissue cultures of tobacco (Nicotiana). Tissue cultures of genotypes known to posses polygenic mechanisms for black shank resistance expressed that resistance in vitro when challenged by the viable pathogen. Callus of a susceptible cultivar was readily parasitized in culture. Furthermore, single gene resistance to the common pathogen race was also shown to operate in vitro. Nongenetic factors examined did not contribute significantly to the observed differences. Disease expression in vitro appeared to be highly correlated with its expression at the whole plant level.Screening for quantitative disease resistance can be complicated at the whole plant level by variable hostpathogen reactions and by significant genotype × environment interactions. Since quantitatively inherited mechanisms of black shank resistance are expressed in tobacco callus cultures, an in vitro host-pathogen system may be useful in screening tobacco lines for black shank resistance.

First pass radionuclide assessment of right and left ventricular ejection fraction in chronic pulmonary disease. Effect of oxygen upon exercise response.

Right and left ventricular ejection fraction (RVEF; LVEF) were determined in patients with severe chronic pulmonary disease (mean +/- SEM [FEV1 percent predicted 36 +/- 3%; PaO2: 64 +/- 3 mm Hg]), utilizing first pass radionuclide angiocardiography. RVEF and LVEF were measured at rest and again during upright bicycle exercise while patients breathed room air, and again during low flow oxygen (O2) administration. Mean RVEF was abnormal (less than 45%) at rest and did not increase with exercise while subjects breathed room air (44 +/- 2 percent vs 44 +/- 3 percent, P = ns), but improved significantly during exercise while patients breathed O2 (45 +/- 5 percent vs 51 +/- 3 percent, P less than .05). Breathing room air, RV exercise ejection fraction was abnormal (less than 5 percent increase in absolute RVEF) in 15 of 18 patients, but only 5 of 10 patients were abnormal during O2 administration. LVEF at rest was normal in all subjects. These data suggest: 1) RV exercise ejection fraction is abnormal in most patients with chronic pulmonary disease; 2) while low flow O2 does not alter RV performance at rest, it improves RV exercise ejection fraction in some patients.

Modified snake venom in amyotrophic lateral sclerosis. Lack of clinical effectiveness.

Diverse observations including neurological examination, manual muscle testing, quantitative electromyography, videotape esophagrams, and pulmonary function tests were used in a double-blind study evaluating the use of detoxified snake venoms as modified neurotoxin in 64 patients with amyotrophic lateral sclerosis (ALS) treated for six months. Transient periods of improvement were more common in the patients who received placebo. This study did not demonstrate any benefit from administration of modified snake venom to patients with ALS.