Surflan and oryzalin impair reproduction in the teleost medaka (Oryzias latipes).

We conducted studies to determine if the xenoestrogens Surflan and its active ingredient oryzalin, affect indices of reproductive fitness in medaka (Oryzias latipes). Oryzalin (0.5, 0.25mg/l) or Surflan (2.0 microl/l) and oryzalin (0.5mg/l) significantly increased the mean number of non-fertilized eggs produced by treated females paired with untreated males, or by untreated females paired with treated males. Oryzalin (1.0, 0.5, 0.25mg/l) and Surflan (3.8, 2.0, 1.0 microl/l) significantly affected the time to hatch of eggs from treated females paired with untreated males, and from untreated females paired with treated males. Surflan (3.8, 2.0, 1.0 microl/l) induced intersex lesions in 80-100% of males. Oryzalin-exposed males exhibited a significant increase in the incidence of necrotic spermatids and necrotic spermatogonia, while oryzalin-exposed females had significantly fewer immature oocytes and an increase in the occurrence of hyperplastic ovaries. Our results indicate that Surflan and oryzalin affect both reproduction and gonadal histology in male and female medaka.

Identification of the herbicide Surflan and its active ingredient oryzalin, a dinitrosulfonamide, as xenoestrogens.

Numerous environmental contaminants have been identified as endocrine disruptors (EDs)--substances that alter endocrine homeostasis by interfering with the biological action, production, or pharmacokinetics of endogenous hormones. Xenoestrogens are those EDs whose biological activity is similar to endogenous estrogen. This report presents data that identified Surflan, a proprietary herbicide emulsion, and its active ingredient oryzalin as xenoestrogens. In vitro, Surflan and oryzalin activated an estrogen-inducible reporter gene, and oryzalin competitively displaced 17beta-estradiol from the estrogen receptor. In vivo, Surflan and oryzalin induced expression of estrogen-regulated high-molecular-weight choriogenin genes in medaka (Oryzias latipes). These results are consistent with the characteristics of previously identified xenoestrogens and indicate that Surflan and oryzalin have the potential to adversely affect numerous estrogen-regulated biological processes.

Gel microdrop flow cytometry assay for low-dose studies of chemical and radiation cytotoxicity.

Low-level cytotoxicity may affect low-dose dose-response relations for cancer and other endpoints. Conventional colony-forming assays are rarely sensitive enough to examine small changes in cell survival and growth. Automated image-analysis techniques are limited to ca. 10(4) cells/plate. An alternative method involves encapsulation of single proliferating cells into ca. 35-75-microm-diameter agarose gel microdrops (GMDs) that are randomly grouped, differential exposure of these groups, culture at 37 degrees C for 3-5 days, and finally GMD analysis by flow cytometry (FC) to determine the ratio of GMDs containing multiple versus single cells as a measure of clonogenic survival. This GMD/FC assay was used to examine low-dose cell killing induced by a cooked-meat mutagen/rodent-carcinogen (MeIQx) in DNA-repair-deficient/metabolically-sensitive CHO cells. Results of conventional colony-forming assays using up to 30 replicate plates indicate a shouldered, threshold-like dose-response; in contrast, those obtained using the GMD/FC assay suggest "hypersensitivity"-like nonlinearity in dose-response. The GMD/FC assay was also applied to human A549 lung cells after GMD-encapsulation and gamma radiation followed by culture for a total of 4 days, to examine survival after exposure to > or =100 cGy delivered at a relatively low dose rate (0.18 cGy/min). Dose-response for clonogenic growth was again observed to be reduced with apparent nonlinear suggesting hypersensitivity between 0 and 50 cGy, insofar as doses of 5 and 10 cGy appear to be ca. fivefold more effective per unit dose than the 50- or 100-cGy doses used. The GMD/FC assay may thus reveal low-dose dose-response relations for chemical and radiation effects on cell proliferation/killing with implications for low-dose risk assessment.

Cervical myelopathy associated with intracranial dural arteriovenous fistula: MR findings before and after treatment.

The MR findings in three patients with intracranial dural arteriovenous fistula associated with cervical myelopathy are described. The MR appearance of an enlarged cord with associated abnormal signal and enhancement is nonspecific and can simulate tumor, demyelination, and inflammation. Enlarged perimedullary vessels may not always be identifiable, but if present, should suggest the presence of an arteriovenous fistula.

SPECT, magnetic resonance and angiographic features in a moyamoya patient before and after external-to-internal carotid artery bypass.

Brain SPECT changes in a patient with cerebral vaso-occlusive disease caused by moyamoya disease are presented. Brain SPECT after a revascularization procedure demonstrated significant improvement of brain flow which was confirmed by angiography. Clinical and magnetic resonance features are reviewed.

Fractured submandibular gland: CT findings.

A patient presented 12 h following trauma with a slowly expanding neck mass. Both CT and sialographic evaluation demonstrated a fracture of the left submandibular gland.

Pharmacokinetics for regulatory risk analysis: the case of 1,1,1-trichloroethane (methyl chloroform).

A methodology for using physiologically based pharmacokinetic (PBPK) models to derive predicted safe concentrations of noncarcinogens in drinking water for humans based on experimentally determined no observed adverse effect levels (NOAELs) in animals is presented and applied to the case of 1,1,1-trichloroethane (methyl chloroform, MC). For each toxic endpoint and lowest corresponding NOAEL identified for MC, we considered a set of toxicologically plausible options regarding the presumed toxic agent and the metric for effective dose to target tissue. A four-compartment PBPK model for rodents was used to estimate corresponding effective doses to the animals used to obtain the experimental NOAELs. A five-compartment PBPK model was then applied, in conjunction with a multiroute (inhalation, ingestion and dermal) human-exposure scenario, to calculate alternative concentrations of MC in drinking water predicted to result in corresponding effective doses to the same target tissues in humans. In the case of MC, the PBPK approach to interspecies and interroute extrapolation of toxicity data resulted in lower drinking water concentrations predicted to be nontoxic to humans than corresponding concentrations obtained using a traditional method for determining safe levels.

Age, sex, and contact with elderly adults as predictors of knowledge about psychological aging.

Using an instrument developed in the United States to assess students' knowledge of mental health in old age, the present study tested 179 Australian undergraduates who varied in age, sex, and the frequency of their contact with aged people at home, at work, and in the neighborhood. As predicted, women scored higher than men and scores rose with age and with contact when age was partialed out. Unexpectedly, Australian students averaged two more items correct than the American students for whom the test was developed. Implications for teaching are considered.

Bacteriology of Electrically Stimulated and Unstimulated Rabbit, Pork, Lamb and Beef Carcasses.

Electrical stimulation of rabbit muscles caused a reduction in count of Pseudomonas putrefaciens and of a Lactobacillus sp. when inoculated muscles were held for 45 min after electrical stimulation. Little if any change in count was detected on rabbit muscles immediately after electrical stimulation and after 20 min of storage. Electrical stimulation (ES) of pork carcasses did not affect the aerobic plate count (APC) of the skin surface. APC of cutaneous trunci from electrically stimulated sides of beef and lamb carcasses were similar to those of muscles from unstimulated sides or carcasses. APC of ground beef and blade steaks fabricated pre-rigor from electrically stimulated sides were often numerically lower after 3 days of storage than those of corresponding samples from unstimulated sides. Differences in APC between conventional and ES samples of ground beef prepared from vacuum packaged top round were significant (P < 0.05) after 6 days of storage. However, none of the other differences in count were statistically significant (P < 0.05). Electrical stimulation did not cause any consistent substantial changes in microbial types of ground beef, blade steaks, T-bone steaks or rib steaks. When minced, aseptically excised supraspinatus muscle was inoculated with either P. putrefaciens or a Lactobacillus sp., counts of these species in tissues from electrically stimulated beef often were significantly lower than those of corresponding unstimulated samples.

Physical and Sensory Characteristics of Pork Loins Stored in Vacuum or Modified Atmosphere Packages.

Wholesale pork loins were either vacuum-packaged, packaged in an atmosphere of 20% CO2 + 80% N2 or packaged in an atmosphere of 40% CO2 + 60% N2. After storage, the primal cuts were evaluated visually for muscle color, fat cover appearance, off-odor, lean surface discoloration and overall appearance. Retail cuts fabricated from the wholesale loins were evaluated for surface discoloration and overall appearance during a 5-day retail display period or they were used for sensory panel evaluation. Few significant differences between packaging treatments were found during the storage period for traits evaluated on the primal cuts. Few significant differences between packaging treatments were observed for either retail display data or sensory panel evaluation.

Inoculation of Beef Steaks with Lactobacillus Species Before Vacuum Packaging. I. Microbiological Considerations.

Biceps femoris steaks were inoculated with each of four Lactobacillus sp. (atypical streptobacteria and beta bacteria) at a high or low level of cell concentration, vacuum-packaged and stored for up to 35 days at 1-3 C. Total lactobacillus counts of inoculated steaks were numerically higher than those of corresponding control (non-inoculated) steaks at nearly all of the storage intervals tested. Differences in lactobacillus counts between steaks inoculated with a high concentration of Lactobacillus cultures 5, 8 and 642, and those of control steaks usually were significant (P < 0.05) after storage for 0 to 28 days. Differences in lactobacillus counts between steaks inoculated with a low concentration of Lactobacillus cultures and those of control steaks were seldom significant (P < 0.05). After storage for 35 days at 1-3 C, differences in lactobacillus counts of inoculated (high or low levels of inoculum) and control steaks usually were not significant (P > 0.05). The lactobacilli encountered on the inoculated steaks consisted primarily of the type added by inoculation.

Inoculation of Beef Steaks with Lactobacillus Species Before Vacuum Packaging. II. Effect on Meat Quality Characteristics.

Biceps femoris steaks (n = 432) were inoculated with each of four Lactobacillus sp. (atypical streptobacteria and betabacteria) at a high or low level of cell concentration, vacuum-packaged, stored for up to 35 days at 1-3 C, displayed under retail conditions for 3 days and subsequently cooked for sensory panel analysis. Although there was some evidence that use of high level, rather than low level or no, inoculation with Lactobacillus cultures resulted in the lowest muscle surface pH and the brightest muscle color, the least surface discoloration and the highest overall appearance ratings following storage for 0-35 days, there were negative effects which negated efficacy of high level inoculation. Negative effects of use of high level, rather than low level or no, inoculation with Lactobacillus cultures included the highest incidence of off-odor, the highest incidence of defects during retail display (most extensive surface discoloration, most extensive peripheral discoloration, least desirable overall appearance) and the lowest palatability (juiciness, tenderness, flavor and overall palatability) ratings. Few of the differences among steaks were statistically significant but the preponderance of evidence (largely that based on numerical differences) suggests that inoculation with the Lactobacillus cultures used in this study will not improve storage life, retail caselife or palatability of beef.

Comprehension of transitive and intransitive phrases by autistic, retarded, and normal children.

Autistic children were compared with retarded and normal control groups in a verbal comprehension task. Subjects were asked to select from four pictures the one that illustrated a two-word intransitive or three-word transitive phrase which was described verbally. Distractor pictures differed from the target picture by one, two, or all three features. Autistic children were poorer in performance than the control groups; however, the hierarchy of difficulty of discrimination was common to all three groups, with transitive phrases more difficult than intransitive phrases. Word type did not affect comprehension for the autistic children, although control children evidenced most difficulty with the verb or middle word. Results are interpreted as supporting the hypothesis that a severe and global language disorder is characteristic of autism.

Role of Hafnia alvei and a Lactobacillus Species in the Spoilage of Vacuum-Packaged Strip Loin Steaks.

A microbiological examination of vacuum-packaged strip loin steaks that were defective (gassy packages, hydrogen sulfide odor) revealed high total counts (107-108/cm2) with Hafnia alvei , Lactobacillus and Pseudomonas spp. as major isolates. Re-inoculation experiments indicated that H. alvei was the likely cause of the hydrogen sulfide odor. Gas formation resulted from the activity of heterofermentative lactobacilli and H. alvei . Improvements in plant practices and temperature control eliminated the problem.