Stability ofAlternaria toxins in fruit juices and wine

Alternaria alternata is a common fungal parasite on fruits and other plants and produces a number of mycotoxins, including alternariol (3,7,9-trihydroxy-1-methyl-6H-dibenzo [b,d]pyran-6-one), alternariol monomethyl ether (3,7-dihydroxy-9-methoxy-1-methyl-6H-dibenzo[b,d]pyran-6-one), and the mutagen altertoxin I {[1S-(1α,12aβ,12bα)] 1,2,11,12,12a, 12b-hexahydro-1,4,9,12a-tetrahydroxy-3,10-perylenedione}. Alternariol and alternariol monomethyl ether have previously been detected in some samples of fruit beverages. Stability studies of these toxins as well as altertoxin I added to fruit juices and wine (10–100 ng/mL) were carried out. To include altertoxin I in the analysis, cleanup with a polymer-based Varian Abselut solid phase extraction column was used, as recoveries from C-18 columns were low. The stabilities of alternariol and alternariol monomethyl ether in a low acid apple juice containing no declared vitamin C were compared with those in the same juice containing added vitamin C (60 mg/175 ml); there were no apparent losses at room temperature over 20 days or at 80°C after 20 min. in either juice. Altertoxin I was moderately stable in pH 3 buffer (75% remaining after a two week period). Furthermore, altertoxin I was stable or moderately stable in three brands of apple juice tested over 1–27 day periods and in a sample of red grape juice over 7 days. It is concluded that altertoxin I is sufficiently stable to be found in fruit juices and should be included in methods for alternariol and alternariol monomethyl ether.     

The metabolism of a stable N-hydroxymethyl derivative of a N-methylamide

N-Formylbenzamide and benzamide were characterised by high pressure liquid chromatography and mass spectrometry as products of the metabolism of N-hydroxymethylbenzamide in incubation mixtures with mouse liver preparations and isolated hepatocytes. This biotransformation occurred predominantly in 9000g and microsomal supernatant fractions and was also catalyzed by horse liver alcohol dehydrogenase fortified with NAD and could be inhibited by pyrazole. Unlike N-hydroxymethylbenzamide, which is very stable, N-formylbenzamide degraded rapidly to benzamide in buffer at pH 7.4 with a half-life of 7.8 min. The instability of N-formylbenzamide and the time course of its metabolic generation together with benzamide suggest that benzamide is a chemical breakdown product of N-formylbenzamide. N-Formylbenzamide was also tentatively identified as a urinary metabolite of N-hydroxymethylbenzamide. This is the first time that an N-hydroxymethyl compound has been shown to undergo metabolism either in vitro or in vivo.     

Sweetgum Dormancy Release: Effects of Chilling, Photoperiod, and Genotype

In Liquidambar styraciflua L., 1200 to 1600 hours of chilling (3°C) resulted in rapid resumption of growth under greenhouse forcing conditions. Long photoperiods were effective substitutes for chilling. Plants from southern Alabama (Lat. 31°) had a lower chilling requirement than those from western Tennessee (Lat. 36°). Growth rate of plants under long photoperiod varied directly with degree of previous chilling.     

The antinociceptive effect and pharmacokinetics of olvanil following oral and subcutaneous dosing in the mouse

Mice were tested for response latency on a 55 degrees C hot plate after subcutaneous (S.C.) or oral administration of olvanil (dose level 200 and 300 mg/kg, respectively). Only the S.C. injection of olvanil produced antinociception. A pharmacokinetics experiment with radiolabeled olvanil (200 mg/kg) was conducted to determine whether this antinociception difference was related to a difference in plasma concentration of olvanil following the two routes of administration. The results indicate that concentrations of radioactivity (olvanil plus metabolites) in plasma reach a peak higher and faster after oral dosing than after S.C. injection. However, the area under the concentration-time curve (AUC) for recovery of radioactivity was slightly higher after the S.C. injection than after the oral dose of olvanil. In contrast, intact olvanil is barely measurable (10 to 30 ng/g) in plasma following an oral dose but is present in high concentration (100 to 2000 ng/g) following S.C. injection. The AUC for olvanil was also higher following a S.C. dose. These data indicate that olvanil fails to produce antinociception after oral dosing in mice not due to lack of absorption, but because it undergoes first pass metabolism.     

An allele-specific suppressor of white-coral in Drosophila melanogaster.

A new allele of white-coral (wco2) was isolated from Canton S after mutagenesis. Many common laboratory stocks were found to carry a suppressor gene (Su(wco2)) which alters the phenotype of wco2 flies toward wild-type. The Su(wco2) is allele-specific (it does not suppress wco), dominant, homozygous viable, located near Su(bwV1) on the right arm of chromosome 2, and shows a simple gene-dosage effect. The degree of suppression is sensitive to the genetic background. There appears to be selection for Su(wco2) in a genotype where it does not affect eye pigmentation.     

Health care in Armenia today.

Although one of the smallest of the new independent states of the former Soviet Union, the Republic of Armenia has an ancient tradition and a strong ethnic identification, greatly enhanced by the diaspora. In addition to the problems following the dissolution of the Soviet Union, Armenia has had to contend with a draining war in Nagorno-Karabakh and the after-effects of a devastating earthquake in 1988. Humanitarian efforts have ranged from emergency supply deliveries to longer-term sustainable health care partnerships. The United States government, through the Agency for International Development, has organized such partnerships, partially as a result of a multinational mission in 1992 and a subsequent hospital-to-hospital program developed by the American International Health Alliance. We describe the current state of health care in Armenia and some of the problems that need to be addressed to improve health care services to its citizens.     

Comparison of secreted and extracted forms of rat pituitary prolactin

Prolactin secreted by rat anterior pituitary explants into organ culture medium was purified by salt fractionation and gel filtration. A yield of 22 mg/g was obtained, which clearly represented de novo synthesis and secretion of the hormone. Comparative characterization studies were performed on the secreted prolactin and pituitary extracted rat prolactin obtained from the National Institute of Arthritis, Metabolism and Digestive Diseases. The biological and immunological activity estimates of both forms were comparable, although the specific activities of the secreted prolactin were somewhat lower than those of the pituitary prolactin. The secreted and extracted forms of prolactin appeared to be identical in primary structure as evidenced by similar amino acid compositions and identical NH₂-terminal sequences. Circular dichroism spectra suggested that there may be differences in tertiary structure, since the positive tryptophan band at 292 nm, which was observed with extracted hormone, was absent in the secreted prolactin.     

Dynamics of Newly Established Elk Populations

Abstract: The dynamics of newly established elk (Cervus elaphus) populations can provide insights about maximum sustainable rates of reproduction, survival, and increase. However, data used to estimate rates of increase typically have been limited to counts and rarely have included complementary estimates of vital rates. Complexities of population dynamics cannot be understood without considering population processes as well as population states. We estimated pregnancy rates, survival rates, age ratios, and sex ratios for reintroduced elk at Theodore Roosevelt National Park, North Dakota, USA; combined vital rates in a population projection model; and compared model projections with observed elk numbers and population ratios. Pregnancy rates in January (early in the second trimester of pregnancy) averaged 54.1% (SE = 5.4%) for subadults and 91.0% (SE = 1.7%) for adults, and 91.6% of pregnancies resulted in recruitment at 8 months. Annual survival rates of adult females averaged 0.96 (95% CI = 0.94-0.98) with hunting included and 0.99 (95% CI = 0.97-0.99) with hunting excluded from calculations. Our fitted model explained 99.8% of past variation in population estimates and represents a useful new tool for short-term management planning. Although we found no evidence of temporal variation in vital rates, variation in population composition caused substantial variation in projected rates of increase (Λ = 1.20-1.36). Restoring documented hunter harvests and removals of elk by the National Park Service led to a potential rate of Λ = 1.26. Greater rates of increase substantiated elsewhere were within the expected range of chance variation, given our model and estimates of vital rates. Rates of increase realized by small elk populations are too variable to support inferences about habitat quality or density dependence.     

Dual Strategies for Argonaute2-Mediated Biogenesis of Erythroid miRNAs Underlie Conserved Requirements for Slicing in Mammals

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