Monoclonal Antibodies against Apple 1-Aminocyclopropane-l-Carboxylate Synthase

1-Aminocyclopropane-l-carboxylate (ACC) synthase from applefruits was purified over 5,000-fold by conventional column chromatography.By immunizing mice with this partially purified enzyme preparation,8 hybridoma lines producing monoclonal antibodies against appleACC synthase were isolated. While all 8 clones immunoprecipitatednative ACC synthase, only two clones recognized the putative(48 kDa) ACC synthase on Western blots. When a partially purifiedACC synthase preparation was incubated with S-adenosyl-L-[carboxyl-¹⁴C]methionine(AdoMet), only one radioactive protein of 48 kDa was detectedon sodium dodecyl sulfate-poly-acrylamide gel electrophoresis.This radioactive protein was specifically immunoprecipitatedby the monoclonal antibodies, indicating that apple ACC synthaseis specifically radiolabeled by its substrate AdoMet, as istomato ACC synthase. Thus, the monoclonal antibodies recognizedboth native and AdoMet-inactivated forms of ACC synthase. Whilethese antibodies failed to im-munoprecipitate ACC synthase isolatedfrom ripe tomato fruits, ripe avocado fruits or auxin-treatedmungbean hypocotyls, they were effective in immunoprecipitatingthe enzyme isolated from ripe pear fruits. (Received August 11, 1990; Accepted October 17, 1990)     

Bioactivity of plasma prolactin in ovariectomized, diethylstilbestrol-treated Long-Evans and Holtzman rats after thyrotropin-releasing hormone or bromocriptine administration

The objective of this study was to determine the effects of thyrotropin-releasing hormone (TRH) and bromocriptine on plasma levels of biologically active prolactin in ovariectomized, diethylstilbestrol (DES)-treated rats. Female Long-Evans and Holtzman rats were ovariectomized and each was given a subcutaneous implant of diethylstilbestrol (DES). One week later, groups of DES-treated rats were fitted with indwelling intra-atrial catheters, and 2 days later blood samples were withdrawn before and at 1, 2, 5, 10, and 20 min after intravenous administration of TRH (250, 500, or 1000 ng/rat). Blood samples were obtained from other groups at 4 weeks of DES treatment by orbital sinus puncture under ether anesthesia before and at 30, 60, and 120 min after bromocriptine administration (2.5 mg/rat sc). Plasma was assayed for prolactin by conventional radioimmunoassay (RIA) and by Nb2 lymphoma bioassay (BA). Holtzman rats released significantly more prolactin following TRH than did Long-Evans rats when the RIA was used to measure prolactin. However, when the BA was used to assay prolactin in the same samples, the Long-Evans rats released more prolactin than did the Holtzman rats. In addition, the ratio of the BA to RIA values was significantly increased in both strains following TRH, but the greatest increase was observed in the Long-Evans rats, in which the ratio was 4.5 at the peak of the TRH-induced rise in plasma prolactin. Gel filtration chromatography of plasma obtained at 5 min after TRH treatment in Long-Evans rats revealed large molecular forms of prolactin with BA to RIA ratios of 4-5. In addition, monomeric prolactin had a BA to RIA ratio of 2. Bromocriptine treatment reduced prolactin levels in both strains, but the effect was more rapid in Holtzman than in Long-Evans rats. In addition, bromocriptine treatment of Holtzman, but not Long-Evans, rats significantly reduced the BA to RIA ratio of plasma prolactin. The results indicate that TRH and bromocriptine affect the release of biologically active prolactin to a greater extent than prolactin detected by antibody in the RIA, and that Long-Evans and Holtzman rats respond to these secretagogues differently with regard to BA to RIA comparisons.     

A comparison of plasma prolactin levels in young female Long-Evans and Holtzman rats as measured by Nb2 lymphoma bioassay and radioimmunoassay

This study was conducted to determine the plasma levels of prolactin in prepubertal and young, postpubertal, proestrus rats of mammary tumor-susceptible (Sprague-Dawley) and tumor-resistant (Long-Evans) strains using a sensitive bioassay-Nb2 lymphoma cell replication. Prepubertal Long-Evans rats had significantly higher levels of prolactin than did Holtzman Sprague-Dawley rats of the same age. Likewise, Long-Evans rats secreted significantly more prolactin into the blood on the afternoon and evening of proestrus than did Holtzman rats. Finally, ovariectomized Long-Evans rats released more prolactin into the blood at 1 day, but not at 8 or 15 days, of treatment with diethylstilbestrol. Prolactin levels determined by conventional radioimmunoassay and by bioassay were similar except on the afternoon of proestrus, when, in both strains of rats, the bioassay to radioimmunoassay ratio increased significantly above 1.0 during the late evening. In addition, the ratio was significantly less than 1.0 in the early and late afternoon in the Holtzman rats, but not Long-Evans rats. These data indicate that a strain of rats that is resistant to experimentally induced mammary cancer has higher prolactin levels in the blood than does a strain that is susceptible to mammary cancer at a time when mammary gland growth is rapid. Furthermore, there are times during the proestrus prolactin surge when the bioassay yielded higher and lower values of prolactin than radioimmunoassay of the same samples, suggesting functional heterogeneity of prolactin that may impact on mammary gland or other target tissue function.     

Changes in soil microflora associated with control of Sclerotium Rolfsii by Furfuraldehyde

The efficacy of 2‐furfuraldehyde for control of Sclerotium rolfsii was studied in laboratory and greenhouse experiments. Mycelial growth of the fungus was reduced proportionally with concentrations of 0.1–0.5 ml furfuraldehyde l^‐1 agar medium, and viability of sclerotia diminished on exposure to 2‐furfuraldehyde vapours. Detectable populations of bacteria and fungi, including Trichoderma spp., were reduced significantly (9=0.05) when furfuraldehyde was added to the agar used for soil dilution plates of untreated soil. Repeated treatments of natural soil with the fumigant significantly increased populations of Trichoderma spp. and bacteria, but diminished numbers of actinomycetes. Increasing dosages applied to soil artificially infested with S. rolfsii caused a reduction of disease on lentil, Lens culinaris. Results indicate that the compound, when applied to field soil, changes the composition of soil microflora and has potential for integrated control of S. rolfsii.     

A Comparison of the Efficacy of Nuclear Polyhedrosis and Granulosis Viruses in Spray and Bait Formulations for the Control of Agrotis segetum (Lepidoptera: Noctuidae) in Maize

Agrotis segetum nuclear polyhedrosis virus (AsNPV) and granulosis virus (AsGV), propagated in laboratory cultures of A. segetum in England and A. ipsilon in Spain, respectively, were applied to plots of maize plants at the one‐ to four‐leaf stage of growth. Plots were arranged in a 6 x 6 Latin square design and infested with second‐instar A. segetum larvae (the common cutworm). Each virus was applied in separate treatments by two application methods; as an aqueous spray containing 0.1% Agral as a wetting agent, and as a bran bait. The NPV was applied at a rate of 4 X 10¹² polyhedra/ha, and the GV at 4 X 10¹³ granules/ha. Soil and plants were sampled for larvae on three occasions following virus treatment: 24 h, 4 days and 11 days. The larvae were reared on diet in the laboratory, until death or pupation, to examine the rate and level of viral infection. Infection data showed 87.5% and 91% NPV infection and 12.5% and 55% GV infection in spray and bait treatments, respectively, in larvae sampled 24 h after treatment. In larvae sampled 4 days after treatment, the results were 78% and 100% NPV infection, and 13% and 6% GV infection. A total of only six larvae were retrieved on day 11. In both treatments larvae infected with AsNPV died significantly more rapidly and at an earlier instar than those infected with AsGV, indicating that AsNPV appears to have better potential as a control agent for A. segetum.     

Simultaneous identification of estrogen and progesterone receptors by HPLC using a double isotope assay.

Polymorphism of estrogen (ER) and progestin receptors (PR) was analyzed simultaneously using high performance hydrophobic interaction chromatography (HPHIC). HPHIC was used previously to characterize four ER isoforms [Hyder et al., J. Chromat. 397 (1987) 251] based on retention times on Synchropak propyl (100 x 6 mm) HPLC columns (Synchrom, Inc.). ER and PR were prepared from human breast cancer. ER was labeled with 3 nM of either [3H]estradiol-17 beta ([3H]E) or [125I]iodoestradiol-17 beta ([125I]E) while PR was associated with 5 nM of either [3H]R5020 ([3H]R) or [125I]iodovinylnortestosterone ([125I]V). ER was resolved by HPHIC into isoforms MI (Rt = 11 min), I(Rt = 16 min), and II (Rt = 24 min). Isoforms I and II each accounted for ca 45% of specific binding. PR separated into isoforms MI (Rt = 14 min) and I (Rt = 21 min, 80% of specific binding) when eluted with the same gradient used for ER chromatography. Upon inclusion of 10 mM molybdate ER resolved into isoforms MI and MII (Rt = 16 min) and PR into isoforms MI and I (here however isoform MI represented 80-95% of specific binding). Elution patterns were preserved with different batches of stationary phase suggesting the integrity of the isoform distribution. HPLC profiles of ER isoforms labeled with earlier [125I]E or [3H]E were identical as were PR isoform profiles labeled with either [3H]R or [125I]V. Pairs of 125I- and 3H-labeled ligands were used in either combination to monitor ER and PR profiles simultaneously. Isoforms analyzed in 50 biopsies gave reproducible retention times, however the ratio between I and II for ER and MI and I for PR varied. This method allows rapid, simultaneous monitoring of the chromatographic behavior of ER and PR isoforms or other associating proteins or nucleotides. One may now better elucidate their interrelationship as it relates to the hormone-response mechanism.     

青海禽棒恙螨属一新种：蜱螨亚纲：恙螨科

本文记述从朱雀Garpodacus erythrinus(Pallas)体上采到的禽棒恙螨属Ornithogastia Vercammen-Grandjean,1960,一新种,朱雀禽棒恙螨Ornithogastia erythinae sp.nov.标本采自青海省海南藏族自冶州贵南县。     

四川鱼类寄生吸虫一新种：（复殖目：尾孔科）

本文记述了尾孔科吸虫一新种——平睾尾孔吸虫,新种Urotrema parallelorchis sp.nov.。新种采自短身间吸鳅和犁头鳅的肠道。新种的睾丸左右排列而不同于该属的所有已知种。