Comparison of the localization of nucleic acid synthesis during bud formation on leaf fragments and on intact undetached leaves ofBegonia rex Putz.

The budding capacity ofBegonia rex leaf fragments is well known; that of undetached leaves has been shown by us only recently after treating the leaves with 6γγ DMAAP. Benzyladenine is as effective as 6γγ DMAAP in stimulating budding. Lower temperatures (17°, 22–12°, 12°) are also capable of inducing bud formation but only after a small cut has been made in a main vein of the undetached leaf. Root formation can also be provoked on undetached leaves which have a cut in the main leaf vein by higher temperatures (24–22°) or by an IAA treatment. Differences in the first stages of bud formation on leaf fragments and on undetached leaves are observed using histochemical and histoautoradiographic techniques.     

Expression of O-glycans during enterocytic differentiation of HT-29 cells

The expression of O- and N-glycan chains during the enterocytic differentiation of HT-29 cells was followed using L-[63H]-fucose and D-[6-3H]-glucosamine radiolabeling. Whatever the cell population, i.e., differentiated or undifferentiated, the incorporation of radiolabeled sugars into glycoproteins was similar. However, differences among these two cell populations were noted when the ratio [3H]-glucosamine/[3H]-galactosamine and the sensitivity of glycopeptides to mild alkaline treatment were followed. From these data, we could conclude that there is a shift in the high molecular weight glycopeptides during the differentiation of HT-29 cells meaning an increase of O-linked glycopeptides correlated with a decrease of N-linked forms.     

Production by K 562 cells of an inhibitor of adherence-related functions of human neutrophils

Certain tumor cells generate factors that inhibit neutrophil chemotaxis. Our study was designed to explore whether such factors are produced by K 562 malignant cells and whether these have a broader effect in altering neutrophil functions. After 48 h of in vitro culture of K 562 cells, the culture medium and the cells were separated, lyophilized, and extracted with ethanol. These K 562 products, i.e., either the cell or supernatant extract, inhibited both nonstimulated locomotion and locomotion induced either by FMLP or activated serum. Furthermore, K 562 products inhibited neutrophil adherence and oxidative burst induced by opsonized zymosan, whereas oxidative burst induced by PMA or FMLP was not altered. K 562 products had an inhibitory effect on the PMN binding to iC3b-coated particles. They did not modify Mo1 expression of resting cells, did not alter the up-regulation of the receptor induced by FMLP but inhibited the FMLP-induced capping of Mo1 Ag. Con A capping was also inhibited. Actin polymerization in FMLP-stimulated PMN, as measured by flow cytometry and phalloidin binding to F-actin, was inhibited by K 562 products. The inhibitory factor present in K 562 products (cell and culture supernatant) was purified in three steps including gel filtration, ion-exchange chromatography, and IEF. The eluted active fraction corresponded to single band of about 8 kDa on SDS-PAGE. From these experiments, it is concluded that K 562 malignant cells in culture contain and release a low molecular mass factor (congruent to 8 kDa) that inhibits all adherence-related functions of neutrophils, whereas it does not alter FMLP- or PMA-induced oxidative burst. Further studies are needed to assess whether products of other tumor cells also act on the neutrophil by inhibiting adherence-related functions, Mo1 function and capping, and actin polymerization.     

Occurrence of Shiga-like toxin-producing Escherichia coli in retail fresh seafood, beef, lamb, pork, and poultry from grocery stores in Seattle, Washington.

Fresh meat, poultry, and seafood purchased from Seattle area grocery stores were investigated for the presence of Shiga-like toxin-producing Escherichia coli by using DNA probes for Shiga-like toxin (SLT) genes I and II. Of the 294 food samples tested, 17% had colonies with sequence homology to SLT I and/or SLT II genes.     

New Isopropyl Chromone and Flavanone Glucoside Compounds from the Leaves of Syzygium cerasiforme (Blume) Merr. & L.M.Perry and Their Inhibition of Nitric Oxide Production

A new isopropyl chromone ( 1 ) and a new flavanone glucoside ( 2 ) together with eleven known compounds ( 3–13 ) were isolated from the leaves of Syzygium cerasiforme (Blume) Merr. & L.M.Perry. Their structures were elucidated as 5,7-dihydroxy-2-isopropyl-6,8-dimethyl-4H-chromen-4-one ( 1 ), 5,7-dihydroxyflavanone 7-O-β-D-(6′′-O-galloylglucopyranoside) ( 2 ), strobopinin ( 3 ), demethoxymatteucinol ( 4 ), pinocembrin-7-O-β-D-glucopyranoside ( 5 ), (2S)-hydroxynaringenin-7-O-β-D-glucopyranoside ( 6 ), afzelin ( 7 ), quercetin ( 8 ), kaplanin ( 9 ), endoperoxide G3 ( 10 ), grasshopper ( 11 ), vomifoliol ( 12 ), litseagermacrane ( 13 ) by the analysis of HR-ESI-MS, NMR, and CD spectral data. Compounds 1 , 2 , 5 , 6 and 10 inhibited NO production on LPS-activated RAW264.7 cells with IC₅₀ values of 12.28±1.15, 8.52±1.62, 7.68±0.87, 9.67±0.57, and 6.69±0.34 μM, respectively, while the IC₅₀ values of the other compounds ranging from 33.38±0.78 to 86.51±2.98 μM, compared to that of the positive control, N^G-monomethyl-L-arginine acetate (L-NMMA) with an IC₅₀ value of 32.50±1.00 μM.     

Environmentally-Friendly Pesticidal Activities of Callicarpa and Karomia Essential Oils from Vietnam and Their Microemulsions

There is an ongoing interest to identify alternative pesticidal agents to avoid the chronic problems associated with synthetic pesticides. Essential oils have shown promise as botanical pest control agents. In the present study, the essential oils of four members of the Lamiaceae (Callicarpa candicans, C. erioclona, C. macrophylla, and Karomia fragrans; Vietnamese names: Nàng nàng, Tu châu lông mem, Tu châu lá to and Cà diện, respectively), obtained from wild populations in Vietnam, have been obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The essential oils were formulated into microemulsions and the essential oils and their microemulsions were screened for mosquito larvicidal activity against Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and for molluscicidal activity against Pomacea canaliculata. Atractylone and (E)-caryophyllene dominated the volatiles of C. candicans (CCEO) and C. erioclona (CEEO), while the major component in C. macrophylla (CMEO) and K. fragrans (KFEO) was (E)-caryophyllene. The essential oils and microemulsions of both C. candicans and C. erioclona exhibited excellent larvicidal activity against all three mosquito species (Ae. aegypti, Ae. albopictus, and Cx. quinquefasciatus) with LC₅₀ values <10 μg/mL. Additionally, the larvicidal activity of the microemulsions were significantly improved compared with their free essential oils, especially for C. candicans and C. erioclona. All four essential oils and their microemulsions showed excellent molluscicidal activity with LC₅₀ <10 μg/mL. In most cases, the essential oils and microemulsions showed greater pesticidal activity against target organisms than the non-target freshwater fish, Oreochromis niloticus. The in silico studies on physicochemical and ADMET properties of the major components in the studied essential oils were also investigated and most of the compounds possessed a favorable ADMET profile. Computational modeling studies of the studied compounds demonstrated a favorable binding interaction with the mosquito odorant-binding protein target and support atractylone, β-selinene, and caryophyllene oxide as potential inhibitors. Based on the observed pesticidal activities of the essential oils and their microemulsions, the Callicarpa species and K. fragrans should be considered for potential cultivation and further exploration as botanical pesticidal agents.     

Nutrition and Physical Activity Program to Attenuate Obesity and Promote Physical and Metabolic Fitness in Elementary School Children

Obesity and low levels of physical and metabolic fitness are risk factors for cardiovascular disease and diabetes. The purpose of this investigation was to attenuate obesity and improve physical and metabolic fitness in elementary school children. Schools have the opportunity, mechanisms, and personnel in place to deliver nutrition education, fitness activities, and a school food service that is nutritious and healthy. Cohorts from grades 3 to 5 in two school districts in rural Nebraska (Intervention/Control) participated in a 2-year study of physical activity and modified school lunch program. Data collection for aerobic capacity, body composition, blood chemistry, nutrition knowledge, energy intake, and physical activity was at the beginning and end of each year. Int received enhanced physical activity, grade specific nutrition education, and a lower fat and sodium school lunch program. Con continued with a regular school lunch and team sports activity program. At year 2, Int lunches had significantly less energy (9%), fat (25%), sodium (21%), and more fiber (17%). However, measures of 24-hour energy intake for Int and Con showed significant differences for sodium only. Physical activity in the classroom was 6% greater for Int compared to Con (p < 0.05) but physical activity outside of school was ?16 % less for Int compared to Con (p < 0.05). Body weight and body fat were not different between schools for normal weight or obese children. No differences were found for cholesterol, insulin, and glucose; however, HDL cholesterol was significantly greater and cholesterol/HDL was significantly less for Int compared to Con (p < 0.05). It appears that compensation in both energy intake and physical activity outside of school may be responsible for the lack of differences between Int and Con.     

Conditions used with a continuous cultivation system to screen for d-hydantoinase-producing microorganisms

The continuous cultivation technique has been used to screen for microorganisms producing d-hydantoinase, a biocatalyst involved in the production of optically active amino acids. Pseudomonas putida strain DSM 84 was used as a model hydantoinase producer to establish selective culture conditions through the addition of various pyrimidines, dihydropyrimidines, hydantoins and 5-monosubstituted hydantoins. Thymine induced more activity than all cyclic amides tested. Addition of thymine as a non-metabolised inducer at a concentration of 0.05 g l^–1 in a continuous culture of P. putida stimulated hydantoinase production up to 80 times the basal level. Using continuous culture conditions established with the model strain, a different strain of P. putida having hydantoinase activity was isolated from commercial mixed cultures of microorganisms. DNA fingerprinting revealed that this new isolate was distinct from strain DSM 84. When used as a probe, the d-hydantoinase gene of strain DSM 84 hybridized with the DNA of the new P. putida isolate.