Fourier transform infrared synchrotron ellipsometry for studying the anisotropy of small organic samples

An experimental setup for polarization-dependent and spectroscopic ellipsometric measurements was developed that utilizes the brilliance of synchrotron infrared radiation at the electron storage ring at BESSY II for investigations of small samples and sample areas. During commissioning of the beamline and the experimental setup, a 1 mm2 piece of a well-characterized polyimide film was studied to show the benefits of Fourier transform infrared (FT-IR) synchrotron ellipsometry. The band shapes are interpreted with respect to the anisotropic distribution of transition dipole moments within the film. In comparison to a globar source, the signal intensity has been improved by more than one order of magnitude for this example.     

The antigenic response of<Emphasis Type="Italic"> β</Emphasis>-lactoglobulin is modulated by thermally induced aggregation

The antigenic response of thermally denatured and aggregated -lactoglobulin was determined by an indirect competitive enzyme-linked immunosorbent assay using polyclonal antibodies from the egg yolk of chicken immunized with heat-denatured -lactoglobulin as a measure for the potential antigenicity/allergenicity. The heat denaturation and the aggregation of heated whey protein isolate solutions were followed by reversed-phase high-performance liquid chromatography and photon correlation spectroscopy. Thermally modified whey proteins showed a remarkable increase of antigenicity when heated to 90 °C, possibly as a consequence of the exposure or formerly hidden epitopes. Above 90 °C, the antigenic response decreased owing to the loss of conformational epitopes and masking of sequential epitopes in the course of aggregation to particles. When large and compact particles were formed, the antigenicity was reduced remarkably. Depending the heating conditions applied, the structure and the size of whey protein particles and thus the potential allergenicity may be modulated in a wide range.     

Inactivation of Bacillus spores in batch vs continuous heating systems at sterilisation temperatures

This study was performed to assess the heat resistance of spores of Bacillus species in batch and continuous heating systems under commercial sterilisation conditions. Spores of thermophilic Bacillus smithii and mesophilic Bacillus amyloliquefaciens were found to be highly heat resistant in the batch system. They were able to withstand typical sterilisation temperatures. B. amyloliquefaciens showed tailing in the batch system and, before the onset of the tailing, a higher inactivation rate than in the continuous system at low temperatures. The reason for the tailing might be the presence of spore aggregates which are disrupted in the continuous system.     

Production of live foals via intracytoplasmic injection of lyophilized sperm and sperm extract in the horse

Work with lyophilized sperm helps delineate the factors required for successful fertilization. We investigated the use of lyophilized sperm in equine embryo production. In Experiment 1, sperm DNA fragmentation index was not affected by three freeze/thaw or lyophilization cycles. In Experiment 2, oocytes injected with lyophilized sperm or with sperm from a treatment in which lyophilized sperm were suspended in sperm cytoplasmic extract (SE) yielded blastocyst development rates of 0 and 28% respectively (P < 0.05). In Experiment 3, blastocyst development rate was 6-11% after injection of sperm lyophilized from fresh or frozen-thawed semen, suspended in SE. In Experiment 4, sperm lyophilized 3.5 months or 1 week previously, suspended in SE, yielded similar blastocyst rates (6 and 3% respectively). Rates of normal pregnancy after transfer were 7/10 and 5/7 for embryos from control and lyophilized sperm treatments respectively. Three pregnancies from the lyophilized sperm treatments were not terminated, resulting in two healthy foals. Parentage testing determined that one foal originated from the lyophilized sperm; the other was the offspring of the stallion providing the sperm extract. Further testing indicated that two of five additional embryos in the lyophilized sperm treatment originated from the stallion providing the sperm extract. We conclude that both lyophilized stallion sperm and stallion sperm processed by multiple unprotected freeze-thaw cycles (as for sperm extract) can support production of viable foals. To the best of our knowledge, this is the first report on production of live offspring by fertilization with lyophilized sperm in a non-laboratory animal species.     

Factors affecting developmental competence of equine oocytes after intracytoplasmic sperm injection

This study was conducted to evaluate the effect of initial cumulus morphology (expanded or compact) and duration of in vitro maturation (24, 30 or 42 h) on the developmental competence of equine oocytes after intracytoplasmic sperm injection (ICSI). The effect of manipulation temperature (room temperature vs 37 degrees C) at the time of ICSI and concentration of glucose (0.55 vs 5.5 mM) during embryo culture was also investigated. The nuclear maturation rates of expanded (Ex) oocytes were significantly (P < 0.001) higher than those of compact (Cp) oocytes at all maturation times (61-72 vs 23-25% respectively). Forty-eight hours after ICSI of mature Ex oocytes, the rate of cleavage with normal nuclei was significantly (P < 0.05) higher for oocytes matured for 24 h than for those matured for 30 or 42 h (73 vs 57-59% respectively). For Cp oocytes, the morphologic cleavage rates for oocytes matured for 30 h were significantly higher (P < 0.05) than for those matured for 24 or 42 h (86 vs 55-61% respectively). The overall proportion of embryos having more than four normal nuclei at 48 h culture was significantly higher (P < 0.05) for Cp than for Ex oocytes. Manipulation temperature did not affect development of embryos from Ex or Cp oocytes at 96 h after ICSI. Culture in high-glucose medium significantly increased morphologic cleavage of Cp, but not Ex, oocytes (P < 0.05). Embryos from Cp oocytes had a significantly higher average nucleus number after 96-h culture than did embryos from Ex oocytes. These data indicate that developmental competence differs between Ex and Cp equine oocytes, and is differentially affected by the duration of maturation and by composition of embryo culture media.     

Miscibility of Quillaja Saponins with other Co‐surfactants under Different pH Values

The miscibility behavior of mixed surfactant systems and the influence of extrinsic parameters are crucial for their application as emulsifiers. Therefore, the objective of this study was to evaluate the miscibility behavior of mixed systems composed of commercial Quillaja saponin and a co‐surfactant, namely sodium caseinate, pea protein, rapeseed lecithin, or egg lecithin. These mixtures were evaluated macro‐ and microscopically at different concentration ratios (maximum concentration 5% w/v) at pH 3, 5, and 7 at 25 °C. The individual ingredients were also assessed for their charge properties and surface hydrophobicity. The results showed that Quillaja saponin–caseinate mixtures were miscible only at pH 7, and showed aggregation and precipitation at lower pH due to increasing electrostatic attraction forces. Rheological measurements showed that Quillaja saponin‐pea protein mixtures formed gelled structures at all tested pH values mainly via association of hydrophobic patches. Quillaja saponins mixed with rapeseed lecithin were miscible at all tested pH values due to electrostatic repulsion. Quillaja saponin–egg lecithin mixtures aggregated independent of pH and concentration ratio. The microscopic analysis revealed that the lower the pH and the higher the Quillaja saponin ratio, the denser were the formed Quillaja saponin–egg lecithin aggregates. The results are summarized in ternary phase diagrams that provide a useful tool in selecting a surfactant system for food applications.     

Effects of stage of oestrous cycle and progesterone supplementation during culture on maturation of canine oocytes in vitro

The aim of this study was to evaluate the effect of progesterone supplementation and stage of oestrous cycle on in vitro maturation (IVM) of canine oocytes. Oocytes were cultured in medium supplemented with 0, 2000, 4000 or 8000 ng progesterone ml(-1) (Expt 1; n=274 oocytes) or 0, 20, 200 or 2000 ng progesterone ml(-1) (Expt 2; n=789 oocytes). In Expt 3, oocytes (n=1202) were cultured in a bi-phasic system of meiotic arrest followed by IVM, both in the presence of 0, 20, 200 or 2000 ng progesterone ml(-1). Rates of meiotic resumption for Expt 1 ranged from 40.0% to 58.5%; there were no significant differences among groups. In Expt 2, rate of meiotic resumption was significantly lower in the 2000 ng progesterone ml(-1) treatment (35.5%) compared with the 200 ng progesterone ml(-1) treatment (54.0%; P<0.05). There were no significant differences in rates of maturation to metaphase II among treatments in Expt 1 (1.8-8.6%) or Expt 2 (8.4-14.7%); however, oocytes collected from ovaries of bitches in oestrus and dioestrus had higher rates of maturation to metaphase II than did oocytes from bitches at pro-oestrus or anoestrus (P<0.01). In Expt 3, no differences were observed in rates of maturation among treatment groups. Rates of maturation to metaphase II of oocytes from bitches in dioestrus were significantly higher than those from bitches in pro-oestrus (P<0.01). These results indicate that supplementation of culture medium with progesterone either during maturation or during meiotic arrest before maturation does not increase the rate of IVM of canine oocytes. However, stage of oestrous cycle is a key factor in the selection criteria for meiotically competent canine oocytes for use in in vitro experiments.     

Effect of a non-steroidal anti-inflammatory drug on tissue levels of immunoreactive prostaglandin E2, immunoreactive leukotriene, and pain after periodontal surgery

The aim of this study was to measure tissue levels of immunoreactive prostaglandin E2 (iPGE2), immunoreactive leukotriene B4 (iLTB4), and pain after periodontal surgery and to evaluate the effect of the non-steroidal anti-inflammatory drug (NSAID), ibuprofen, on these levels. Two contralateral quadrants in each of nine patients were selected to undergo separate surgical procedures, one with ibuprofen (800 mg 1 hour presurgery and 400 mg postsurgery) and one with a placebo. Intra-operatively, a custom-made microdialysis probe, with a 3,000 dalton molecular weight cut-off, was inserted beneath the soft tissue flap and a dialysate collected every 20 minutes for 4 hours after surgery. Pain perception was measured at the same time intervals using two pain scales. Dialysate samples were assayed using two enzyme immunoassays. Mean tissue levels of iPGE2 in the placebo group increased from 74 nM at 40 minutes to a peak of 261 nM at 200 minutes. Mean tissue levels of iLTB4 in the placebo group fluctuated between 0.2 and 0.6 nM. Pain levels in this group increased continuously with time, peaking at 4 hours. Mean tissue levels of iPGE2 in the ibuprofen group were significantly suppressed, exhibiting more than a 95% reduction. This was accompanied by a significant reduction in pain. Ibuprofen had no detectable effect on tissue levels of iLTB4. These data indicate that iPGE2 and iLTB4 are present at relatively high concentrations in the periodontal tissues after surgery. Since these concentrations exceed the Kd values for binding to their respective receptors, PGE2 and LTB4 may be associated with the development of postsurgical pain and inflammation. These data also indicate that ibuprofen can successfully inhibit iPGE2 production in the periodontal tissues and in this way may help reduce postoperative pain and inflammation.