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.     

Follicular development and ovulation in Macaca fascicularis,Saimiri sciureus and Galago senegalensis

A technique utilizing laparoscopy to determine the precise time of ovulation in three species is described. Determination is based on morphological changes that occur 24 to 36 hours before ovulation. This technique, coupled with mating sessions of short-duration, has been used to produce precisely defined pregnancies; the implications of this technique in reproduction research and teratology are discussed. A comparison of ovulation times in Macaca fascicularis indicates that ovulation normally occurs on day 13 of animals having a cycle length from 25 to 28 days. In animals with a cycle length from 31 to 34 days, ovulation occurred on day 14.8. Evidence presented does not substantiate previous claims for alternation between ovaries in consecutive cycles.     

Assignment of ring size in isopropylidene acetals by carbon-13 n.m.r. spectroscopy

A series of 1-O-acylaldose derivatives was prepared in good yield through the reaction of 1,3-dialkyl-O-glycosylpseudoureas with carboxylic acids.     

Prenatal development of cutaneous afferent connections in the spinal cord of fetal sheep

In this study we have examined the physiological and neurochemical development of the cutaneous afferent pathways from the hindlimb to the spinal cord in fetal sheep. We have shown that somatosensory input from the hindlimb evokes activity in DRG neurons at 87d gestation and in cells in the dorsal horn at 92d (term, 146d). There is evidence of immunoreactivity for substance P, calcitonin gene-related peptide and glutamine several days prior to this at 77-80 days. The implication of these findings are discussed.     

Effect of chilling and cryopreservation on expression of Pax genes in zebrafish (Danio rerio) embryos and blastomeres

Cryopreservation is now common practice in the fields of aquaculture, conservation and biomedicine. However, there is a lack of information on the effect of chilling and cryopreservation at the molecular level. In the present study, we used real-time RT-PCR analysis to determine the effect of chilling and cryopreservation on expression of Pax2a, Pax2b, Pax5 and Pax8 which constitute one subgroup of the Pax gene family. As intact embryos of zebrafish have not yet been successfully cryopreserved, we have used two alternatives: chilling of intact embryos and cryopreservation of isolated blastomeres. Cryopreservation was found to affect the normal pattern of gene expression in zebrafish embryonic blastomeres. The trends, profile changes, in expression of Pax2a and Pax5 occurred to a lesser extent in frozen-thawed blastomeres than in fresh blastomeres whilst the opposite was true for Pax8. The trends in expression of Pax2b were delayed in frozen-thawed blastomeres compared to fresh blastomeres. Cryopreservation can therefore disrupt normal gene expression patterns in zebrafish embryonic blastomeres which could have a detrimental effect on embryo development.