Behavior of Listeria monocytogenes inoculated into raw tomatoes and processed tomato products

Rates of death and growth of Listeria monocytogenes inoculated onto raw whole and into chopped tomatoes stored at 10 and 21 degrees C were not influenced by prior treatment of tomatoes with chlorine or packaging under an atmosphere of 3% O2 and 97% N2. Growth of the pathogen occurred in whole tomatoes held at 21 degrees C but not at 10 degrees C, while death occurred in chopped tomatoes stored at these temperatures. Likewise, growth patterns of mesophilic aerobic microorganisms, psychrotrophic microorganisms, and yeasts and molds on whole and chopped tomatoes were essentially unaffected by chlorine and modified atmosphere packaging treatments. Populations of L. monocytogenes inoculated into commercially processed tomato juice and sauce and held at 5 degrees C remained constant for 14 days. A gradual decrease in the number of viable L. monocytogenes cells was observed in juice and sauce held at 21 degrees C. In contrast, the organism died rapidly when suspended in commercial tomato ketchup at 5 and 21 degrees C. Unlike low-acid raw salad vegetables such as lettuce, broccoli, asparagus, and cauliflower on which we have observed L. monocytogenes grow at refrigeration temperatures, tomatoes are not a good growth substrate for the organism. Nevertheless, L. monocytogens can remain viable on raw whole and chopped tomatoes and in commercial tomato juice and sauce for periods extending beyond their normal shelf-life expectancy.     

MAJOR CLADES OF THE ANGIOSPERMS

Abstract— Our knowledge of fundamental angiosperm interrelationships is still very incomplete. The absence of a narrowly circumscribed gymnosperm outgroup, ideally the sister group, makes character evaluation, necessary for a cladistic analysis, difficult. According to current views the superorder Magnoliiflorae with a number of other groups, for example the monocotyledons, may represent a complex of families near the base of the angiosperms. Interrelationships of groups within the monocotyledons are much better understood than those between groups within the dicotyledons. A cladogram of monocotyledon orders based on earlier work by R. Dahlgren, H. T. Clifford, and F. N. Rasmussen is presented. A data matrix for a sample of the angiosperms with 61 characters for 49 taxa, mostly magnoliifloran and related families, is presented. The characters are polarized mainly according to the current view that the primitive angiosperm morphotype is a woody dicotyledon with strobiloid flowers. As an alternative the matrix is adjusted following W. C. Burger's conjecture that the primitive angiosperm was a herbaceous monocotyledon with trimerous flowers. Both matrices were run in a computerized parsimony analysis, resulting in numerous equally parsimonious solutions. This result is illustrative of the great homoplasy in the available character information, and also of how little actually is known about fundamental angiosperm interrelationships or phylogeny.     

Assignment of orthologous relationships among mammalian alpha-globin genes by examining flanking regions reveals a rapid rate of evolution

In order to study the relationships among mammalian alpha-globin genes, we have determined the sequence of the 3' flanking region of the human alpha 1 globin gene and have made pairwise comparisons between sequenced alpha-globin genes. The flanking regions were examined in detail because sequence matches in these regions could be interpreted with the least complication from the gene duplications and conversions that have occurred frequently in mammalian alpha-like globin gene clusters. We found good matches between the flanking regions of human alpha 1 and rabbit alpha 1, human psi alpha 1 and goat I alpha, human alpha 2 and goat II alpha, and horse alpha 1 and goat II alpha. These matches were used to align the alpha-globin genes in gene clusters from different mammals. This alignment shows that genes at equivalent positions in the gene clusters of different mammals can be functional or nonfunctional, depending on whether they corrected against a functional alpha-globin gene in recent evolutionary history. The number of alpha-globin genes (including pseudogenes) appears to differ among species, although highly divergent pseudogenes may not have been detected in all species examined. Although matching sequences could be found in interspecies comparisons of the flanking regions of alpha- globin genes, these matches are not as extensive as those found in the flanking regions of mammalian beta-like globin genes. This observation suggests that the noncoding sequences in the mammalian alpha-globin gene clusters are evolving at a faster rate than those in the beta-like globin gene clusters. The proposed faster rate of evolution fits with the poor conservation of the genetic linkage map around alpha-globin gene clusters when compared to that of the beta-like globin gene clusters. Analysis of the 3' flanking regions of alpha-globin genes has revealed a conserved sequence approximately 100-150 bp 3' to the polyadenylation site; this sequence may be involved in the expression or regulation of alpha-globin genes.      

Procedural improvements for in vitro production of viable uterine stage caprine embryos

Efforts to improve proportions of caprine immature oocytes developing into viable uterine-stage embryos in vitro involved study of 1924 oocytes in experiments designed to examine influences of fertilization media, sperm incubation temperatures, sperm treatment procedures, different protein supplementations, and different insemination intervals. Oocytecumulus complexes (OCCs) were matured during 27 h in TCM-199 supplemented with 20% FBS, 100 μg LH ml⁻¹, 0.5 μg FSH ml⁻¹, and 1 μg Estradiol-17-β ml⁻¹at 38.5 °C in a humidified 5% CO₂, 5% O₂, and 90% N₂ atmosphere. Freshly collected sperm were washed and incubated at either 22 °C or 38.5 °C for 5 h and then treated with either 0.1 μM calcium ionophore A23187 for 1 min, or with 7.35 mM calcium lactate in the presence of oocytes during the insemination interval, or with 100 μg heparin +2 mM caffeine ml⁻¹ for 15 min. The interval for insemination was experimentally varied i.e. 14 or 24 h. Results showed that: (a) when used as a fertilization medium mDM supported more blastocyst development than TALP (10.5% vs. 0%, P < 0.05); (b) incubation temperatures of 22 °C or 38.5 °C prepared goat spermatozoa equally for capacitation in mDM containing 20% FBS; (c) when oocytes were inseminated with sperm incubated in mDM with 20% FBS and capacitated with calcium lactate more embryos reached the blastocyst stage (P < 0.05) than after incubation in the same conditions but after sperm capacitation with heparin, and A23187 (31.8% vs. 24.2% and 10.2%, respectively; (d) a 24 h insemination interval was not superior to 14 h when sperm were incubated with either 20% FBS or 6 mg BSA ml⁻¹ and capacitated with calcium lactate (P > 0.05). Three morulae resulting from the best conditions in this work (FBS, calcium lactate, 14 h insemination) were transferred into the uterine horn ipsilateral to the corpus luteum of a recipient and two normal female kids were born after normal gestation. This is the first report in which it has been possible to consistently take caprine development to the blastocyst stage in vitro, and to obtain offspring following uterine transfer. Methodology reported here should facilitate implementation of new reproductive and genetic strategies in goat breeding.     

P48-Triggered transmembrane signaling transduction of human monocytes:mobilization of calcium ion and activation of protein kinase C(PKC)

INTRODUCTI0NThedifferentiati0nofcelIsalongthemonocyte-macr0phagepathwayandthesig-nalsinvo1vedinthesecel1sacquiringtheabilitytokilltum0rcellsarenotfllllyundersto0d.Wehavebeenstudingamoleculewhichappearst0beanimportantmemberofthecytokinenetworkinvo1vedintheregulati0nmonocyteactivation.ThiscytokinetermedP48wasisolatedfr0mthehllmannullcellleukemiacell1ineReh.IthasbeenpurifiedtohomogeneityandfOundtobedistinctfrominterferongamma,col0nystimulatingfactors(CSFs)andTNFalphaalldbeta[1,2].Func-ti…     

Term development of caprine embryos derived from immature oocytes in vitro

Ovaries were surgically removed from female goats (Toggenburg, Nubian and Saanen breeds). Oocytes were collected by follicular aspiration or after ovaries were minced, then matured in mTCM-199 with 100 mug LH + 0.5 mug FSH + 1.0 mug estradiol 17-beta/ml for 27 h prior to in vitro fertilization (17). Although more oocytes were made available by mincing than by aspiration, higher proportions of aspirated oocytes were fertilized and developed to morulae. Proportions that fertilized and reached morulae were 82 102 (80.4%) and 50 102 (49.0%) versus 77 126 (61.1%) and 27 126 (21.4%) for oocytes obtained by aspiration and after ovarian mincing, respectively (P<0.05). Proportions of inseminated ova undergoing cleavage and continuing development to the morula stage differed significantly (P<0.05) among 5 co-culture treatment groups, with higher proportions of cleavage (23 27 , 85.2%) and morulae (14 27 , 51.9%) obtained by co-culture on caprine cumulus cells (cCC). Some oocytes reached the blastocyst stage (4 54 , 7.4%) following oocyte collection by aspiration and culture on caprine oviduct epithelial cells (cOEC). After 4- and 8-cell stage embryos obtained by aspiration and culture on cCC were transferred pregnancy resulted. Twin male kids (developed from different embryos) were born on August 6, 1993, and have developed into normal bucks. Conditions reported here provided an adequate environment for support of oocyte maturation, fertilization and early embryonic development in vitro (IVMFC) with normal development after embryo transfer.