Ocular toxicity and distribution of subconjunctival and intravitreal rapamycin in horses

In vitro photosensitivity of rapamycin (RAPA) and ocular toxicity and distribution of intravitreal and subconjunctival RAPA was evaluated in normal horses. RAPA (2.5 mg, 5 mg, and 10 mg) was placed in 10 mL of PBS and maintained in a water bath at 37 °C, kept in the dark or subjected to room light, and sampled for up to 3 months for RAPA levels. Six normal adult horses received either 5 mg (n = 2) or 10 mg (n = 2) of RAPA intravitreally or 10 mg (n = 2) subconjunctivally. Ophthalmic exams and electroretinography (ERG) were performed prior to injection and on days 1, 7, 14, and 21 post‐injection. Eyes were enucleated and samples were collected for RAPA concentrations and histopathology. No difference in light vs. dark RAPA concentrations was observed, suggesting a lack of RAPA phototoxicity. No evidence of ocular toxicity was noted on ophthalmic examination or histopathology. RAPA was not detected intraocularly 7 days post‐injection in eyes receiving subconjunctival RAPA, but was detected in the vitreous at 21 days post‐injection. Drug could be detected in both the aqueous and vitreous humor after intravitreal injection. Further study is needed to determine the efficacy of intravitreal RAPA.     

Azoturia in a Greyhound: clinical pathology aids to diagnosis

A provisional diagnosis of azoturia and/or haematuria was made in a Greyhound. This condition was differentiated from the syndromes of acute abdominal accident, acute nephritis, cystitis and spinal pressure on sensory nerves by means of the clinical pathology aids of biochemistry, serum enzymology, haematology and urine analysis and the physical aid of X-ray and ECGT. The results indicated that the animal was suffering from acute azoturia.
Résumé. Un cas d'azoturie et/ou hématurie fut diagnostiquée comme probable chez un Lévrier. Cet état fut différencié des syndromes de troubles abdominaux accidentels aigus, de néephrite aiguë, de cystite, et de pression spinale sur les nerfs sensoriels, au moyen des aides procurées à la pathologie clinique par la biochimie, la séroenzymologie, l'hématologie et les analyses d'urine, et avec l'aide de la physique, par Rayons-X et électro-encéphalographie. Les résultats indiquèrent que l'animal souffrait d'une azoturie aiguë.
Zusammenfassung. Eine Wahrscheinlichkeits-Diagnose der Azoturie und/oder Blutharnen, wurde im Windhund vorgenommen. Diese Kondition differenzierte sich den Syndromen von Bauchakzidenz, akuter Nierenentzündung, Blasenentzündung und Rückgratsdruck des Sinnesnerven durch physikalische Hilfe von Röntgenstrahlen und EEG. Das Untersuchungsergebniss deutete an, dass das Tier von akuter Azoturie litt.     

Simulation study of the competitive ability of erect, semi-erect and prostrate cowpea (Vigna unguiculata) genotypes

Ecophysiological simulation models provide a quantitative method to predict the effects of management practices, plant characteristics and environmental factors on crop and weed growth and competition. The INTERCOM interplant competition model was parameterised, calibrated by monoculture data for three cowpea (Vigna unguiculata) genotypes that differed in growth habit, common sunflower (Helianthus annuus) and common purslane (Portulaca oleracea), and used to simulate competition of cowpea cover crops with sunflower or purslane. The simulation results were compared with observations from field competition experiments in 2003 and 2004. INTERCOM more accurately simulated actual field data for the competition of cowpea genotypes and sunflower than companion field experiments for the competition of cowpea and purslane. The validated simulation model of cowpea and sunflower at two densities was used to study the effects of cowpea growth habit on final biomass production of cowpea and sunflower. The model suggested that erect growth habit was more competitive than semi‐erect and prostrate growth habit, when cowpea genotypes were grown with sunflower. Cowpea leaf area distribution was important to higher cowpea biomass production, while cowpea height growth was important to reduce sunflower biomass. Our simulation approach is suggested as a method for crop breeders to gauge the likely success of selection for competitive crops before undertaking expensive long‐term breeding experiments.     

Mapping and predicting a candidate gene for flesh color in watermelon

The color of watermelon flesh is an important trait determined by a series of carotenoids. Herein, we used Cream of Saskatchewan(pale yellow flesh) and PI 186490(white flesh) as parental materials for an F2 segregation and initial mapping using the bulked segregant analysis sequencing(BSA-seq) strategy. The BSA results revealed a flesh colorrelated QTL that spans approximately 2.45 Mb on chromosome 6. This region was preliminarily positioned in a 382-kb segment, and then narrowed down into a 66.8-kb segment with 1 260 F2 individuals. A total of nine candidate genes were in the fine mapping interval, but only Cla007528(encoding chlorophyllase) had non-synonymous mutations and was significantly expressed between the parental materials throughout flesh development. We also checked the expression patterns of the carotenoid metabolic pathway genes based on RNA-seq data and qRT-PCR validation. Three genes in the xanthophyll cycle(ClCHYB, ClNCED-1 and ClNCED-7) exhibited differential expression patterns between the two parental lines at different flesh color formation stages. ClPSY1, ClPDS, ClZDS, ClCHXE, ClCRTISO and ClLCYB also exhibited clearly different expression patterns accompanied by carotenoid accumulation.     

FACTORS AFFECTING THE PHYTOTOXICITY OF PARAQUAT*

Summary. Temperatures of 5–6° C delayed leaf necrosis of glasshouse-grown oats (Avena sativa), winter peas (Pisum sativum), huisache (Acacia farnesiana), mesquite (Prosopis julijiora var. glandutosa), live oak (Quercus virginiana) and yaupon (Ilex vomitoria) for at least 48 hr after treatment with paraquat as compared with higher temperatures. After 96 hr, oats, winter peas, huisache and mesquite at 5° C usually showed as much necrosis as plants at 24–28° C. Similar results were obtained with live oak and yaupon, and with yaupon in the field, except that longer periods were sometimes required for plants at low temperatures to develop injury comparable with that at higher temperatures. Washing yaupon and live oak leaves 1 hr after application reduced the effectiveness of paraquat regardless of temperature, but washing winter peas 10 min after application had little or no effect on phytotoxicity. Field-grown mesquite showed extensive leaf necrosis when leaves were washed after 20 min, live oak leaves similarly treated and washed were not injured, while the response of winged elm (Ulmus alata) was intermediate. Percentage leaf necrosis of mesquite, winged elm, yaupon and live oak increased with increasing paraquat concentration; 6–9 μg/leaf on mesquite and 20 μg/leaf on winged elm gave 100% necrosis after 4 days. Complete leaf necrosis of live oak and yaupon was not attained during this period even with 80 μg/Ieaf. Nursery-grown mesquite, yaupon and greenbriar (Smilax bona-nox) and natural stands of yaupon were treated at two growth stages, in March and May. Paraquat was more effective on mesquite when applied in May, but there were no differences with the other species. Facteurs affectant la toxicité du paraquat     

NEUROSPORA MUTANT LACKING AN ARGININE-SPECIFIC CARBAMYL PHOSPHOKINASE

An arginine-requiring mutant of Neurospora lacks the carbamyl phosphokinase activity present in other strains. Although carbamyl phosphate, the product of this enzyme, is required in both arginine and pyrimidine synthesis, the enzymne appears to serve only the arginine pathway. A pyrimidine specific mode of carbamyl phosphate synthesis is inferred, although it has not yet been demonstrated.