Quantitative detection of bisphenol A and bisphenol A diglycidyl ether metabolites in human plasma by liquid chromatography–electrospray mass spectrometry

Due to the ubiquity of epoxy resin compounds and their potential role in increasing the risk for reproductive dysfunction and cancer, the need for an assessment of human exposure is urgent. Therefore, we developed a method for measuring bisphenol A (BPA) and bisphenol A diglycidyl ether (BADGE) metabolites in human blood samples using high-performance liquid chromatography–electrospray ionization mass spectrometry (LC–MS). Human blood samples were processed using enzymatic deconjugation of the glucuronides followed by a novel sample preparation procedure using a solid-phase-cartridge column. This selective analytical method permits rapid detection of the metabolites, free BPA and a hydrolysis product of BADGE (BADGE-4OH) with detection limits in the low nanogram per milliliter range (0.1 ng ml⁻¹ of BPA and 0.5 ng ml⁻¹ of BADGE-4OH). The sample extraction was achieved by Oasis HLB column on gradient elution. The recoveries of BPA and BADGE-4OH added to human plasma samples were above 70.0% with a standard deviation of less than 5.0%. This selective, sensitive and accurate method will assist in elucidating potential associations between human exposure to epoxy-based compounds and adverse health effects.     

Condensation of oligoglycines with trimeta- and tetrametaphosphate in aqueous solutions

The dehydration condensation of glycine with trimetaphosphate in aqueous solution has been reinvestigated. Although it has been reported that the condensation of glycine under the alkaline conditions was brought about through the formation of cyclic acylphosphoramidate and hence the condensation of polyglycines could not occur, we found that the condensation of oligoglycines with trimeta- and tetrametaphosphate in aqueous solution are possible through the formation of their acylphosphates under the neutral or weak acidic conditions.Aqueous solutions of 1.0 M glycylglycine and 1.0 M trimetaphosphate in the various pH from 4.0 to 9.0 were incubated at 38 °C. The solutions were analyzed by HPLC with ninhydrin reaction system. Tetraglycine and hexaglycine were detected and their maximum yields were given in the reaction carried out around pH 7. They are approximately 15% and 4% after 30 days, respectively. Analogous experiments were performed with tetrametaphosphate. The results showed a similar pH dependence for the condensation, but the yields were about one-tenth of those of corresponding experiments with trimetaphosphate.Relative rates of dimerization of glycine, diglycine and triglycine in the equimolar concentration were also investigated at pH 6.0 at 38 °C. The rates for digylcine and triglycine were approximately twice and four times as large as that for glycine.Relevance of the experiments to chemical evolution is discussed.     

Effect of Gibberellic Acid on the Ultrastructure and {alpha}-Amylase Activity of Aleurone Cells of Avena sativa L.

The -amylase activity and ultrastructure of aleurone cells inseeds of Avena sativa L. were studied using seed halves withembryo (embryo seeds) which had imbibed water and seed halveswithout embryo (embryo-less seeds) which had imbibed water withor without GA₃. -Amylase activity was detected in the aleurone layers of embryoseeds that had imbibed water and embryo-less seeds that hadimbibed GA₃-water. The ultrastructure of aleurone cells withdetectable -amylase activity showed marked changes in the roughsurfaced endoplasmic reticulum (rER), in the flattened sacculesforming stacks and in the aleurone grains. The progressive changesin the rER were as follows: first, the number of slender rERincreased; then, the inner space became wider and showed roundor oval profile; and finally, the rER became slender again witha reduced number of adhering ribosomes. The flattened sacculesforming stacks were appressed to the surface of aleurone grains.With time, they decreased in number and finally disappeared.In parallel with the decrease of flattened saccules, digestionof proteinaceous material inside the aleurone grains proceeded. (Received February 24, 1987; Accepted September 3, 1987)     

Effect of UV-B (290–320 nm) irradiation on growth and metabolism of cucumber cotyledons

Cucumber ( Cucumis sativus L. cv. Natsusairaku 3) seedlings were grown in a growth cabinet under UV-B (290–320 nm) irradiation (equivalent to the UV-B radiation normally incident at Tokyo, 36°N latitude, during clear sky conditions in mid-april on a weighted daily fluence basis) and a UV-B-free control condition. UV-B irradiation inhibited the growth of the cotyledons, i.e. the increase in area, and increase in fresh and dry weights of the cotyledons. The greatest inhibition rate was observed in the increase in area, causing a significant increase in specific leaf weight (the ratio of weight to area). UV-B irradiation had no significant effect on DNA and RNA contents in the cotyledons, but decreased protein content slightly. In contrast, the irradiation reduced the amounts of organic acids and soluble sugars, indicating that primary carbon metabolism was very sensitive to UV-B radiation. UV-B irradiation lowered the photosynthetic activity in the cotyledons without any effect on chlorophyll content and respiratory activity. These results indicate that UV-B radiation at the ambient level may act as a physiological stress in some UV-sensitive plants.     

TheRT1.G locus in the rat encodes a Qa/TL-like antigen

A new antigenic system in the rat homologous to theQa/TL antigen system in the mouse has been characterized. It was detected by antibodies raised in donor-recipient combinations that were matched for theRT1. A, B, D, E loci in the major histocompatibility complex (MHC): (R11×BN)F₁ anti-BN.1L(LEW), (R18×BN)F₁ anti-BN.1L, and BN.1LV1(F344) anti-BN.1L. Absorption analyses using these antisera and a variety of inbred, congenic and recombinant strains identified three alleles,RT1.G ^a ,G ^b ,G ^c , of whichG ^c is a null allele. The strain distribution of these alleles was determined, using 37 strains of rats representative of all of the prototypic haplotypes and a number of congenic and recombinant strains. The use of the congenic and recombinant strains showed that theRT1.G locus was linked to the MHC and that the most probable gene order wasA-E-G. Testcross analysis showed that the map distance betweenA andG was 1.4 cM(4/285 recombinants). The RT1.G antigen has a heavy chain ofM _r 46 000 and is present on both T and B cells.     

Proportionality of ELF electric field-induced growth inhibition to induced membrane potential inZea mays andVicia faba roots

Summary The postulate that 60-Hz electric field-induced bioeffect severity is proportional to induced transmembrane potential [ ] magnitude was tested and supported using a plant root model cell system. Statistically significant correlations were obtained upon regression of the relative rates of exposedVicia faba andZea mays root segment growth on the average (calculated) arising in those segments under specified 60 Hz field exposure conditions. The associated with the apparent threshold for growth inhibition was similar inZea andVicia roots (2.5 vs 2.4 mV, respectively). At greater than this threshold,Zea root growth declined by about 9% per mV, andVicia root growth by about 19% per mV induced potential.Abbreviations EF electric field - RGR relative growth rate - RSGR relative segmental growth rate - induced membrane potential - segmental-average induced membrane potential - VC _d region of root tip in which a complete, nascent vascular cylinder is first distinguishable in histological sections     

Correction of inverted nipple with periductal fibrous flaps.

I devised a method to correct the inverted nipple considering the preservation of the lactiferous ducts, sensory fibers to the nipple, and the contracting function of the areolar muscle. Excision of the excess skin at the base of the nipple was done in three diamonds fashion, and they were located at 2, 6, and 10 o'clock positions not to jeopardize the sensory fibers to the nipple. To release the fastened nipple, the periductal fibrous tissue was thoroughly dissected and made into three flaps pedicled inferiorly. These three flaps were sutured to the dermis of the periareolar skin to pull up the nipple base by means of traction in three directions. The purse-string suture, the dermal stitch on the shorter diagonals of the diamond-shaped defects, anchors the skin-muscle bridges caught at the base of the ductal column, makes the nipple base narrower, obtains stable anchoring, helps the areolar muscle contraction to resume, and prevents the recurrence of the inversion. The use of the periductal tissue as flaps to bring in areolar skin for easier anchoring and for more prominent eversion of the nipple has not been described in the literature.     

Inactivation and sedimentation of mercury from organomercurials by Klebsiella pneumoniae

Abstract A susceptibility of 63 clinical isolates of Klebsiella pneumoniae to inorganic and organic mercuric compounds was determined. 18 of them were found to be resistant to fluorescein mercuric acetate (FMA) and merbromin (MB). Moreover, all the resistant strains inactivate the antibacterial effect of FMA. The changes in the amount of organic mercury at the time of inactivation of the drug and the structures of the end products were examined in detail with the plasmid-bearing strain JK9 and its transconjugants of Escherichia coli .
The results showed that FMA was inactivated by an intracellular enzyme produced inducively and was degraded to fluorescein (sodium salt, uranine), which led to the sedimentation of metallic mercury. The discovery of the genes conferring inducible organic mercury-inactivating enzymes determined by plasmids was the next step and their application in the recovery of metallic mercury from organomercurials is now imminent.     

Accumulation and lethal effect of tritium (tritiated water) inRhodopseudomonas spheroides

Nonsulfur purple photosynthetic bacteria, Rhodopseudomonas spheroides cells were cultured in medium containing tritiated water (THO) under the light-anaerobic and dark-aerobic conditions. The experimental R value defined as specific activity ratio of organic bound 3H to THO in medium was 0.49 and 0.48 for the light-anaerobically grown cells and the dark-aerobically grown cells, respectively. From the relation of R value to number of weight doubling of the cells (n), ratio of experimental R to theoretical R, i.e., (2n-1)/2n derived by assuming no isotope effect, was 0.51 and 0.49 on an average for the light-anaerobically grown cells and the dark-aerobically grown cells, respectively. 3H-incorporation from THO-medium into the light-anaerobic nongrowing cells was affected by the light intensity and suppressed by adding HgCl2, KCN, and 2,4-dinitrophenol as well as 3H-labelling in the dark-aerobic nongrowing cells was affected by oxygen tension and suppressed by adding these metabolic inhibitors. From the fractionation of the lyophilized cells by modified Schneider method, the distribution of exchangeable 3H in cold acid-soluble and ether-ethanol-soluble fractions and nonexchangeable 3H bound to small molecules and macromolecules was 7.4/25.3/67.3 in the growing cells cultured anaerobically in the THO-medium up to late exponential phase in the light. The distribution in the nongrowing cells incubated anaerobically with the THO-medium for 18 h in the light of 300 and 3,000 lux was 82.1/8.4/9.5 and 58.2/19.2/22.6, respectively. These distributions of 3H were changed with growth phase and/or incubation time. On the biological effect of 3H-THO for the cells stocked at -196 degrees C to accumulate 3H-decays, the dark-aerobic nongrowing cells labelled with THO were rather radiosensitive than the dark-aerobically and light-anaerobically grown cells cultured in the THO-medium. The killing efficiencies, i.e., the probability that a single disintegration would be lethal, ranged from 1/200 to 1/275 for the above three kinds of cells labelled with THO. The killing efficiencies for R. spheroides labelled with THO were similar to that for radiosensitive strain CB13 and wild strain Hfr of Escherichia coli labelled with 3H-thymidine and stored at -196 degrees C.