Presence of Leptin and Its Receptor in the Hypothalamus,Uterus and Ovaries of Swine Females Culled with Distinct Ovarian Statuses and Parities

Leptin acts on energy metabolism, affecting reproductive functions through activation of its receptors in the brain and in reproductive organs. This study compared the presence of leptin and its receptor (ObR‐b) in hypothalamus neurons, endometrial glands and oocytes of culled swine females across ovarian statuses and parities. Immunohistochemistry was done in samples of uterus, ovaries and hypothalamus from 28 culled females, using polyclonal antibodies antileptin and ObR‐b. Immunolabelling was compared for sows categorized by parity at culling (0, 1, 2–4 and <4) and ovarian status (luteal and follicular phases of the oestrous cycle and with cysts). Immunolabelling for leptin and ObR‐b in neurons and oocytes was weaker in females with cysts (p < 0.05) than in those at the follicular phase. In endometrial glands, leptin immunolabelling was less intense in females with cysts (p < 0.05), but immunolabelling for ObR‐b was similar across ovarian statuses (p > 0.05). In sows culled with 2–4 parities, leptin immunolabelling in neurons and endometrial glands was more intense than in nulliparous females (p < 0.05). In comparison with sows culled at greater parities, ObR‐b immunolabelling for nulliparous females was less intense in endometrial glands and in oocytes (p < 0.05), but more intense in neurons (p < 0.05). Thus, in swine, the presence of leptin and ObR‐b varies across parities and is more intense in the uterus, ovaries and hypothalamus of females that were cycling before culling than in those having cystic ovaries.     

Activity of delta8- and delta9-tetrahydrocannabinol and related compounds in the mouse

The 11-hydroxy metabolites of Delta(8).- and Delta(9)-tetrahydrocannabinol are more active than the parent compounds when administered to mice by either the intravenous or intracerebral route. Both Delta(8)- and Delta(9)-tetrahydrocannabinol are rapidly and extensively metabolized by the liver and not by the brain. The hypothesis that the 11-hydroxy metabolites may be the active form of tetrahydrocannabinol is discussed     

Spectroscopic identification of carbonate minerals in the martian dust

Thermal infrared spectra of the martian surface indicate the presence of small concentrations (approximately 2 to 5 weight %) of carbonates, specifically dominated by magnesite (MgCO3). The carbonates are widely distributed in the martian dust, and there is no indication of a concentrated source. The presence of small concentrations of carbonate minerals in the surface dust and in martian meteorites can sequester several bars of atmospheric carbon dioxide and may have been an important sink for a thicker carbon dioxide atmosphere in the martian past.     

Procion brown: an intracellular dye for light and electron microscopy

Procion browvn has been used to inject lamprey giant interneutros. The dye is opaque to both light and electrons, and imparts a pink color to the neuron in situ during iontophoresis. It has the advantage over cobaltolus chloride that postinjection treatment with ammonium sulfide is eliminated and the integrity of the surrounding neuropil is ensured.     

Reduction of bacterial growth by a vesicular-arbuscular mycorrhizal fungus in the rhizosphere of cucumber (Cucumis sativus L.)

Summary Cucumber was grown in a partially sterilized sand-soil mixture with the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus fasciculatum or left uninoculated. Fresh soil extract was places in polyvinyl chloride tubes without propagules of mycorrhizal fungi. Root tips and root segments with adhering soil, bulk soil, and soil from unplanted tubes were sampled after 4 weeks. Samples were labelled with [³H]-thymidine and bacteria in different size classes were measured after staining by acridine orange. The presence of VAM decreased the rate of bacterial DNA synthesis, decreased the bacterial biomass, and changed the spatial pattern of bacterial growth compared to non-mycorrhizal cucumbers. The [³H]-thymidine incorporation was significantly higher on root tips in the top of tubes, and on root segments and bulk soil in the center of tubes on non-mycorrhizal plants compared to mycorrhizal plants. At the bottom of the tubes, the [³H]-thymidine incorporation was significantly higher on root tips of mycorrhizal plants. Correspondingly, the bacterial biovolumes of rods with dimension 0.28–0.40×1.1–1.6 m, from the bulk soil in the center of tubes and from root segments in the center and top of tubes, and of cocci with a diameter of 0.55–0.78 m in the bulk soil in the center of tubes, were significantly reduced by VAM fungi. The extremely high bacterial biomass (1–7 mg C g^-1 dry weight soil) was significant reduced by mycorrhizal colonization on root segments and in bulk soil. The incorporation of [³H]-thymidine was around one order of magnitude lower compared to other rhizosphere measurements, probably because pseudomonads that did not incorporate [³H]-thymidine dominated the bacterial population. The VAM probably decreased the amount of plant root-derived organic matter available for bacterial growth, and increased bacterial spatial variability by competition. Thus VAM plants seem to be better adapted to compete with the saprophytic soil microflora for common nutrients, e.g., N and P, compared to non-mycorrhizal plants.     

Development of a polyclonal antibody-based sensitive enzyme-linked immunosorbent assay for fumonisin B(4)

Polyclonal antibodies (PAb) against fumonisin B(4) (FmB(4)), which have good cross-reactivity with four major fumonisins, were produced by immunizing a rabbit with FmB(4)-keyhole limpet hemocyanin conjugate. A sensitive competitive direct enzyme-linked immunosorbent assay (CD-ELISA) for fumonisins was developed. Because of the limited supply of FmB(4), both FmB(1)-horseradish peroxidase conjugate (HRP) and FmB(3)-HRP were tested as the toxin-enzyme markers in the CD-ELISA. In the FmB(1)-HRP-based CD-ELISA, the concentrations of FmB(1), FmB(2), FmB(3), and FmB(4) causing 50% inhibition of binding of enzyme marker (IC(50)) were 9.0, 2.1, 9.0, and 6.5 ng/mL (or the relative cross-reactivities toward FmB(1), FmB(2), FmB(3), and FmB(4) were 58.5, 309.5, 58.5, and 100%), respectively. In the FmB(3)-HRP-based CD-ELISA, the IC(50) values for FmB(1), FmB(2), FmB(3), and FmB(4) were 7.1, 1.9, 7.6, and 5.3 ng/mL (or the relative cross-reactivities toward FmB(1), FmB(2), FmB(3), and FmB(4) were 74, 280, 70, and 100%), respectively. The FmB(3)-HRP-based CD-ELISA was then used in a series of analytical recovery experiments using Fusarium moniliforme corn culture material spiked with FmB(1) and with clean corn spiked with a FmB(3)/FmB(4)-containing extract. The overall recovery of FmB(1) from culture material in the range of 10-100 ppm was 65%. The detection limit for FmB(1) with clean corn as matrix was between 100 and 500 ppb. F. moniliforme cultures were analyzed with the developed CD-ELISA and a well-established FmB(1) antibody-based ELISA, which is not sensitive to FmB(4). Differences in the fumonisin levels found by the two assays were used as an indication of the presence of FmB(4) in the culture material and, therefore, as a method to identify FmB(4)-producing strains. Using ELISA in combination with HPLC individual B-series fumonisins were quantified. The ELISA developed in the present study would be a useful supplement to FmB(1) antibody-based ELISA for screening of Fusarium strains for the production of major fumonisins.     

Yields of wheat and soil carbon and nitrogen contents following long-term incorporation of barley straw and ryegrass catch crops

Abstract. Three successive crops of winter wheat were grown on a sandy loam to test the residual effect of long‐term annual incorporation of spring barley straw at rates of 0, 4, 8 and 12 t ha^?1, and ryegrass catch crops with or without additions of pig slurry. Soil receiving 4, 8 and 12 t ha^?1 of straw annually for 18 years contained 12, 21 and 30% more carbon (C), respectively, than soil with straw removal, and soil C and nitrogen (N) contents increased linearly with straw rate. The soil retained 14% of the straw C and 37% of the straw N. Ryegrass catch‐cropping for 10 years also increased soil C and N concentrations, whereas the effect of pig slurry was insignificant. Grain yield in the first wheat crop showed an average dry matter (DM) increase of 0.7 t ha^?1 after treatment with 8 and 12 t straw ha^?1. In the two subsequent wheat crops, grain yield increased by 0.2–0.3 t DM ha^?1 after 8 and 12 t straw ha^?1. No grain yield increases were found after 4 t straw ha^?1 in any of the three years. Previous ryegrass catch crops increased yields of wheat grain, but effects in the third wheat crop were significant only where ryegrass had been combined with pig slurry. Straw incorporation increased the N offtake in the first wheat crop. In the second crop, only 8 and 12 t straw ha^?1 improved wheat N offtake, while the N offtake in the third wheat crop was unaffected. Ryegrass catch crops increased N offtake in the first and second wheat crop. Again, a positive effect in the third crop was seen only when ryegrass was combined with slurry. Long‐term, annual incorporation of straw and ryegrass catch crops provided a clear and relatively persistent increase in soil organic matter levels, whereas the positive effects on the yield of subsequent wheat crops were modest and transient.