Progression and stop organization reveals conservation of movement organization during dark exploration across rats and mice.

Spatial orientation is a ubiquitous feature of animal behavior. Environmental and self-movement cues are sources of information used to maintain spatial orientation. The literature has typically focused on differences between mice and rats using environmental cues to guide movement. The current study uses the organization of exploratory behavior under dark conditions to investigate species differences in self-movement cue processing. Mouse and rat exploratory behavior was recorded under dark conditions on a circular table without walls. The resulting movements were segmented in progressions (movement ≥ 3 cm/s) and stops (movement < 3 cm/s). Mice exhibited longer travel distances, faster progression peak speeds, and weaker tendency to scale progression peak speeds to Euclidean distances relative to rats. In contrast, similar levels of performance were observed on measures (progression path circuity, change in heading, stability of stopping behavior) sensitive to vestibular pathology. These results are consistent with species differences in a variety of performance variables; however, self-movement cue based spatial orientation did not differentiate between mice and rats. This work establishes a translational foundation for future work investigating the neurobiology of self-movement cue processing using species-unique neuroscience techniques.

Conidial movement of nontoxigenic Aspergillus flavus and A. parasiticus in peanut fields following application to soil.

The use of nontoxigenic strains of Aspergillus flavus and A. parasiticus in biological control effectively reduces aflatoxin in peanuts when conidium- producing inoculum is applied to the soil surface. In this study, the movement of conidia in soil was examined following natural rainfall and controlled precipitation from a sprinkler irrigation system. Conidia of nontoxigenic A. flavus and A. parasiticus remained near the soil surface despite repeated rainfall and varying amounts of applied water from irrigation. In addition, rainfall washed the conidia along the peanut furrows for up to 100 meters downstream from the experimental plot boundary. The dispersal gradient was otherwise very steep upstream along the furrows and in directions perpendicular to the peanut rows. The retention of biocontrol conidia in the upper soil layers is likely important in reducing aflatoxin contamination of peanuts and aerial crops such as corn and cottonseed.

Propofol sedation for endoscopic procedures in children.

BACKGROUND AND STUDY AIMS: Propofol sedation has been used successfully in various outpatient minor procedures in children. Limited data are available on the usefulness of propofol sedation during gastrointestinal endoscopic procedures in children. The aim of this study was to evaluate our experience of propofol sedation in pediatric gastrointestinal endoscopic procedures. MATERIALS AND METHODS: The charts of all children who had undergone diagnostic endoscopic procedures, and were sedated by propofol, were retrospectively reviewed. Demographic data, cardiovascular monitoring, and drug dosages were recorded. Patients evaluated their sedation efficacy by answering a questionnaire before discharge. RESULTS: A total of 104 children underwent 107 procedures. Propofol alone was given in 19 procedures and in combination with midazolam and/or fentanyl in 88 procedures. All procedures were completed and significant complication occurred in only one patient. No significant difference was observed in the amount of sedative drugs or recovery time between upper and lower endoscopic procedures. A lower propofol dosage was needed when a combination of drugs was given compared to propofol drug alone. Patients' assessment of their sedation showed that the vast majority had experienced postendoscopic amnesia. CONCLUSION: Propofol sedation for endoscopic procedures is safe and acceptable for children. Propofol sedation should be offered to young children, especially those who express significant anxiety.

Effect of Aspergillus parasiticus soil inoculum on invasion of peanut seeds.

Environmental control plots adjusted to late season drought and elevated soil temperatures were inoculated at peanut planting with low and high levels of conidia, sclerotia, and mycelium from a brown conidial mutant of Aspergillus parasiticus. Percentage infection of peanut seeds from undamaged pods was greatest for the subplot containing the high sclerotial inoculum (15/cm2 soil surface). Sclerotia did not germinate sporogenically and may have invaded seeds through mycelium. In contrast, the mycelial inoculum (colonized peanut seed particles) released large numbers of conidia into soil. Soil conidial populations of brown A. parasiticus from treatments with conidia and mycelium were positively correlated with the incidence of seed infection in undamaged pods. The ratio of A. flavus to wild-type A. parasiticus in soil shifted from 7:3 to 1:1 in the uninoculated subplot after instigation of drought, whereas in all subplots treated with brown A. parasiticus, the ratio of the two species became approximately 8:2. Despite high levels of brown A. parasiticus populations in soil, native A. flavus often dominated peanut seeds, suggesting that it is a more aggressive species. Sclerotia of wild-type A. parasiticus formed infrequently on preharvest peanut seeds from insect-damaged pods.

Performance of two immunochemical assays in the analysis of peanuts for aflatoxin at 37 field laboratories.

A study was conducted to measure the precision of 2 rapid aflatoxin assay systems in use at 37 peanut buying points during the 1991 harvest season. Aflatoxin laboratories were established at the 37 buying points to analyze peanut samples from all incoming farmers' stock loads as part of a joint project sponsored by various segments of the U.S. peanut industry and the U.S. Department of Agriculture. Eighteen laboratories were equipped with Neogen's veratox FSP rapid assay system, whereas 19 laboratories used Vicam's Aflatest rapid assay system. To monitor the performance of the field laboratories during the project, 3 portions of each of six 27 kg samples of ground peanuts were sent to each laboratory for analysis over a period of 6 weeks. Aflatoxin concentrations ranged from 0 to 300 ng/g when eight 200 g subsamples of each sample were analyzed by liquid chromatography (LC). For the 5 samples contaminated with aflatoxin, relative standard deviations for repeatability (RSDr) for laboratories using veratox FSP ranged from 18.66 to 53.29%, and the relative standard deviations for reproducibility (RSDR) ranged from 22.79 to 59.29%. For laboratories using the Aflatest system, RSDr values ranged from 18.70 to 41.48%, and RSDR values ranged from 23.84 to 47.56%. Horwitz ratios < 2.0 were found for 4 of the 5 contaminated samples for both methods, indicating that the overall precision of the 2 methods used in the project was good. Mean aflatoxin concentrations, as determined with the rapid assay systems, were generally lower than those determined by LC, particularly for more highly contaminated samples.(ABSTRACT TRUNCATED AT 250 WORDS)

Interrelationship of kernel water activity, soil temperature, maturity, and phytoalexin production in preharvest aflatoxin contamination of drought-stressed peanuts.

Samples of Florunner peanuts were collected throughout a period of late-season drought stress with mean geocarposphere temperatures of 29 and 25 degrees C, and determinations of maturity, kernel water activity (aw), percent moisture, capacity for phytoalexin production, and aflatoxin contamination were made. Results showed an association between the loss of the capacity of kernels to produce phytoalexins and the appearance of aflatoxin contamination. Kernel aw appeared to be the most important factor controlling the capacity of kernels to produce phytoalexins. Mature peanuts possessed additional resistance to contamination that could not be attributed solely to phytoalexin production. Kernel moisture loss was accelerated in the 29 degrees C treatment compared to the 25 degrees C treatment, and data indicated that the higher soil temperature also favored growth and aflatoxin production by Aspergillus flavus in peanuts susceptible to contamination.

Color mutants of Aspergillus flavus and Aspergillus parasiticus in a study of preharvest invasion of peanuts.

A comparison of the invasion of flowers, aerial pegs, and kernels by wild-type and mutant strains of Aspergillus flavus or A. parasiticus along with aflatoxin analyses of kernels from different drought treatments have supported the hypothesis that preharvest contamination with aflatoxin originates mainly from the soil. Evidence in support of soil invasion as opposed to aerial invasion was the following. A greater percentage of invasion of kernels rather than flower or aerial pegs by either wild-type A. flavus or mutants. Significant invasion by an A. parasiticus color mutant occurred only in peanuts from soil supplemented with the mutant, whereas adjacent plants in close proximity but in untreated soil were only invaded by wild-type A. flavus or A. parasiticus. Aflatoxin data from drought-stressed, visibly undamaged peanut kernels showed that samples from soil not supplemented with a mutant strain contained a preponderance of aflatoxin B's (from wild-type A. flavus) whereas adjacent samples from mutant-supplemented soil contained a preponderance of B's plus G's (from wild-type and mutant A. parasiticus). Preliminary data from two air samplings showed an absence of propagules of A. flavus or A. parasiticus in air around the experimental facility.

Increased excretion of histidyl-L-proline diketopiperazine by infants receiving Pregestimil and Nutramigen formulas.

Histidyl-L-proline diketopiperazine is excreted in increased amounts by infants receiving Nutramigen or Pregestimil. When these formulas are discontinued, its excretion becomes undetectable. The compound was isolated from Nutramigen and Pregestimil, as well as from the urine of the infants receiving these formulas, and was identified by comparison with authentic histidyl-L-proline diketopiperazine standard in various chromatographic and electrophoretic systems. A neuropeptide widely distributed in the brain and gut and having a variety of biological functions, histidyl-L-proline diketopiperazine may have as-yet-undetermined effects on infants who are receiving these formulas.

HPLC assay of phenylalanine and tyrosine in blood spots on filter paper.

Blood spots on filter paper are used to screen for phenylketonuria. We have developed a high pressure liquid chromatographic assay of phenylalanine and tyrosine after elution of these amino acids from filter paper. The analysis time is 20 min. The amino acids are separated using an ion-exchange resin with post-column ortho-phthalaldehyde derivatization and subsequent fluorescence detection. Other common amino acids do not interfere. The assay is linear from 20 pmol to at least 2,000 pmol with a coefficient of variation of 3%. The assay is as accurate as the determination of phenylalanine by ion-exchange ninhydrin-reactive methods currently in use, but is 100 times more sensitive. The method has the advantages of avoiding venipuncture, is cost effective, has a high sensitivity, and a rapid turnaround.

Combined xanthine and sulphite oxidase defect due to a deficiency of molybdenum cofactor.

Increased urinary excretion of xanthine, hypoxanthine, sulphite, thiosulphate and decreased serum uric acid were observed in an infant with profound failure to thrive. Other clinical findings included refractory seizures, spastic quadriplegia and profound psychomotor retardation. The patient died at 20 months of age. There were no detectable activities for xanthine oxidase and sulphite oxidase in the postmortem liver. Urothione, which is the metabolic excretory product of the molybdenum cofactor for molybdoenzymes was not present in the urine. A deficiency of the molybdenum cofactor which is common to both xanthine and sulphite oxidase is presumed to be the metabolic defect responsible for the absent activities of both enzymes.

Mean geocarposphere temperatures that induce preharvest aflatoxin contamination of peanuts under drought stress.

Apparently undamaged peanuts grown under environmental stress in the form of drought and heat become contaminated with Aspergillus flavus and aflatoxin in the soil prior to harvest. The upper mean temperature limit for aflatoxin contamination in undamaged peanut kernels grown under drought stress the latter 4-6 weeks of the growing season was between 29.6-31.3 degrees C. The lower limit was between 25.7-26.3 degrees C. That is, peanuts grown under drought stress with a mean geocarposphere temperature of 29.6 degrees C were highly contaminated while those at 31.3 degrees C were not contaminated. Likewise, those grown under drought stress with a mean geocarposphere temperature of 25.7 degrees C were not contaminated while those subjected to a mean geocarposphere temperature of 26.0 degrees C resulted in some categories becoming contaminated. Increasing the mean temperature up to 29.6 degrees C caused increasing amounts of contamination.

Gamma-glutamylornithine excretion in patients with hyperornithinemia.

Gamma-glutamylornithine has been identified in urine from patients with the HHH syndrome (hyperornithinemia, hyperammonemia and homocitrullinuria) and with gyrate atrophy associated with hyperornithinemia. The amount of gamma-glutamylornithine excreted was 10-15 times higher than that excreted in normal subjects. The level of excretion was comparable in the HHH syndrome subjects and the gyrate atrophy subjects despite the fact that the gyrate atrophy subjects excreted more ornithine. A 100 mg/kg oral challenge of ornithine increased the excretion of gamma-glutamylornithine by a factor of three. This increased excretion of gamma-glutamylornithine was observed in hyperornithinemia patients with different etiologies and is therefore presumably due to the hyperornithinemic state, per se, independent of the underlying defect.

Effect of soil temperature and drought on peanut pod and stem temperatures relative to Aspergillus flavus invasion and aflatoxin contamination.

Peanut stem and pod temperatures of plants growing in irrigated, drought, drought-heated soil, and drought-cooled soil treatments were determined near the end of the growing season. Mean soil temperatures of the treatments during this period were 21.5 degrees, 25.5 degrees, 30 degrees and 20 degrees C, respectively. Peanut stem temperatures in all drought treatments reached a maximum of ca. 40 degrees C and for 6-7 h each day were as much as 10 degrees C warmer than irrigated peanut stems. Pod temperatures in drought-heated soil and drought treatments were ca. 34 degrees C and 30 degrees C, respectively, for several hours each day. As pod temperatures approached the optimum for A. flavus growth (ca. 35 degrees C), the proportion of kernels colonized and aflatoxin concentrations increased. Increased plant temperature without accompanying pod temperature increases (drought-cooled soil) resulted in colonization percentages and aflatoxin concentrations only slightly higher than those of the irrigated peanuts.

Effect of geocarposphere temperature on pre-harvest colonization of drought-stressed peanuts by Aspergillus flavus and subsequent aflatoxin contamination.

Florunner peanuts grown in research plots were subjected to 5 soil temperature and moisture treatment regimes resulting in A. flavus infestation and subsequent aflatoxin contamination in drought-stressed peanuts. Treatments imposed beginning 85 days after planting were drought, drought with heated soil and 3 drought treatments with cooled soil. The incidence of A. flavus in drought-stressed, unshelled , sound mature kernels ( SMK ) decreased with decreases in the mean 5 cm deep soil temperature. The incidence of A. flavus was greater in inedible categories and in damaged kernels than in SMK . The mean, threshold, geocarposphere temperature required for aflatoxin development during the latter part of the peanut growth cycle was found to be between 25.7 degrees C and 27 degrees C.

Effects of soil moisture and temperature on preharvest invasion of peanuts by the Aspergillus flavus group and subsequent aflatoxin development.

Four soil temperature and moisture treatment regimens were imposed on Florunner peanuts 94 days after planting in experimental plots in 1980. At harvest (145 days after planting), the incidence of the Aspergillus flavus group and the aflatoxin concentration were greatest in damaged kernels. Extensive colonization of sound mature kernels (SMK) by the A. flavus group occurred with the drought stress treatment (56% kernels colonized); colonization was less in the irrigated plot (7%) and the drought stress plot with cooled soil (11%) and was intermediate in the irrigated plot with heated soil (26%). Aflatoxin was virtually absent from SMK with the last three treatments, but it was found at an average concentration of 244 ppb (ng/g) in drought-stressed SMK. Colonization of SMK by the A. flavus group and aflatoxin production were greater with hot dry conditions. Neither elevated temperature alone nor drought stress alone caused aflatoxin contamination in SMK. When the ratio of SMK colonized by A. flavus compared with A. niger was greater than 19:1, there was aflatoxin contamination, but there was none if this ratio was less than 9:1. Irrigation caused a higher incidence of A. niger than drought did. This may have prevented the aflatoxin contamination of undamaged peanuts.

Hydroxyproline metabolism in two sisters with hydroxyprolinemia.

Hydroxyproline metabolism was evaluated in two sisters with hydroxyprolinemia and their mother. 33 and 21% of an oral hydroxyproline load (200 mg/kg) was excreted by the sisters, 5.4% by the mother, and 1.3% by normal subjects. Plasma and erythrocyte values in the sisters and their mother were elevated, indicating that extra- and intracellular hydroxyproline pools were increased. Analysis for urinary glycolate and oxalate (metabolic products of hydroxyproline) showed no increased excretion by the two sisters, although the mother's excretion was normal. A deficiency of hydroxyproline oxidase in the two sisters was indicated by the lack of delta 1-pyrroline-3-hydroxy-5-carboxylic acid excretion.

Loss of transferase enzyme activity of transfused erythrocytes in galactosemia.

Rapid loss of erythrocyte galactose-1-phosphate uridyl transferase in hemolysates from an infant 26 days after transfusion led to investigation of the possiblity of an unstable enzyme or other variant of galactosemia. However, the child was found to have the classic type of galactosemia. The seeming transferase instability was attributable to loss of enzyme activity in hemolysates from blood containg aged, transfused cells, the source of the enzyme. Thus when transfusion is necessary, transferase assay for diagnosis of the enzyme deficiency before transfusion avoids confusion attributable to the enzyme supplied in the transfused cells.