Changes in allergenicity and digestibility of squid tropomyosin during the Maillard reaction with ribose

The effect of the Maillard reaction on the allergenicity of squid tropomyosin (TM) was investigated. When TM was reacted with ribose (TM-ribose), its human-specific IgE-binding ability decreased markedly and alpha-chymotryptic digestibility of TM was also altered at the early stage of the Maillard reaction. On the other hand, the modification of the lysine residues in TM using 2,4,6-trinitrobenzenesulfonic acid had no effect on the allergenicity and alpha-chymotryptic digestibility of TM. Therefore, the structural change in TM induced by the Maillard reaction would cause the reduction of the allergenicity, rather than the block of lysine residues. Although peptic digestion diminished the specific IgE-binding ability of TM, the reduction of the allergenicity by the Maillard reaction remained after peptic digestion. These results suggest that hypersensitive reaction of TM-ribose in the human body might be lower than that of native TM.     

Effect of postactivation treatment with latrunculin a on in vitro and in vivo development of cloned embryos derived from kidney fibroblasts of an aged clawn miniature boar

The objective of this study was to examine the effect of postactivation treatment with latrunculin A (LatA), an actin polymerization inhibitor, on in vitro and in vivo development of somatic cell nuclear transfer (SCNT) embryos derived from kidney fibroblasts of an aged Clawn miniature boar (12 years old). After electric activation, SCNT embryos were treated with 0, 0.5 or 1 μM LatA and cultured in vitro. The rate of blastocyst formation was significantly higher (P<0.05) in SCNT embryos treated with 0.5 μM LatA (38%) than those in control (14%). When cloned embryos treated with 0.5 μM LatA were transferred into the oviducts of two recipient miniature gilts to assess their development in vivo, both recipients became pregnant; one maintained pregnancy to term, and a live piglet (weighing 220 g) was delivered by Caesarean section. The results of this study indicated that the postactivation treatment with LatA was effective in improving in vitro developmental capacity of SCNT miniature pig embryos derived from kidney fibroblasts of an aged animal and that miniature pig cloned embryos treated with LatA had the ability to develop to term.     

Synthesis and antifungal activity of imidazole-1-carboxylates

A series of imidazole-1-carboxylates was prepared by reacting various alcohols with trichloromethyl chloroformate and imidazole or N,N'-carbonyl-diimidazole. They were tested for fungitoxic activity in vitro against two phytopathogenic fungi, Botrytis cinerea (grey mould) and Gibberella fujikuroi, and for preventive efficacy against grey mould on cucumber leaves. 1-(4-Substituted phenoxymethyl)-2,2-dimethylpropylimidazole-1-carboxylates showed excellent in-vitro activity against B. cinerea, and moderate activity against G. fujikuroi, and some of them also effectively controlled grey mould in vivo. A 1H-1,2,4-triazole derivative corresponding to an imidazole derivative did not have any activity, while a thiocarboxylate corresponding to an imidazole carboxylate showed excellent activity against both B. cinerea and G. fujikuroi.     

ST segment depression and ventricular fibrillation in a dog after contrast agent administration

An 11-year-old Toy Poodle underwent a computed tomography examination with contrast (iohexol) enhancement under anesthesia. Heart rate and R-wave amplitude on electrocardiogram (ECG) increased 2.5 min after iohexol administration, and end-tidal carbon dioxide decreased to 12 mmHg. A progressive ST segment depression was observed on ECG. Subsequently, the ECG waveform changed to ventricular fibrillation. However, spontaneous circulation returned following cardiopulmonary resuscitation. Myocardial ischemia or anaphylactic shock was suspected in the dog, which explains the ST segment depression observed on ECG. When performing radiological examinations with a contrast agent, the ECG waveform changes, such as an increase in heart rate, R-wave amplitude, or ST segment depression, should be carefully monitored. This might enable early detection of cardiac dysfunction and the ensuing cardiac arrest in dogs.     

Storage of plug seedlings of tomato under limited fertilisation,and growth,flowering and yield after planting

We stored plug seedlings of tomato (Solanum lycopersicum L. cv. Momotaro) under limited fertilisation (LF) for 12 weeks, and evaluated growth and development during storage and after planting. Seedlings in the LF treatment were grown in substrate containing starter fertiliser and irrigated with water. Controls (CT) were irrigated with nutrient solution. Stem growth, leaf growth, and biomass accumulation slowed or ceased during storage of LF seedlings, while CT seedlings showed increases in these parameters. At 2 weeks after planting, the stem length of LF seedlings was shorter than that of CT seedlings, but the two seedling types had similar numbers of leaves. At harvest, LF and CT plants had similar numbers of leaves under the fruit trusses, but the trusses formed at lower heights in LF than in CT seedlings. LF and CT plants produced similar numbers of fruits and similar yields from the first to third trusses. These results indicate that tomato plug seedlings can be stored for more than 2 months under LF.     

Polymorphism analysis of Fagaceae and DNA-based identification ofFagus species grown in Japan based on therbcL gene

Fagaceae species in Japan were identified by restriction fragment length polymorphism (RFLP) and sequence comparison of a region ofrbcL. Of nine restriction endonucleases used for digestion, three (MspI,RsaI,HaeIII) produced different restriction patterns in Fagaceae. Digestion byMspI yielded four patterns: Fagus species,Castanea crenata, Pasania glabra, and others. Digestion byRsaI andHaeIII afforded two patterns:Fagus species and others. These facts indicate thatCastanea crenata andPasania glabra can be identified byMspI restriction patterns ofrbcL. Sequence comparison of a region of therbcL gene among 20 species of Fagaceae showed that: (1) they could be divided into seven groups; (2) there is a site mutation betweenFagus crenata andF. japonica. The latter indicates that the wood of both Fagus species are identifiable at the species level, which is not the case using conventional methods. This result indicates the possibility of wood identification based on DNA polymorphism in Fagaceae at the intrageneric level.Part of this paper was presented at the 46th annual meeting of the Japan Wood Research Society, Kumamoto, April 3–5, 1996 and the 47th annual meeting of the Japan Wood Research Society, Kochi, April 3–5, 1997     

Availability of potato protein concentrate as an alternative protein source to fish meal in greater amberjack (Seriola dumerili) diets

Potato protein concentrate (PPC) is a promising candidate as a fish meal (FM) substitute because it has high protein and essential amino acid content. In the present study, we replaced FM in greater amberjack diets with PPC to investigate the effect on growth and feed utilization. Four isonitrogenous, isolipidic and isocaloric experimental diets were prepared by substituting 0, 20, 40 and 60% of FM protein with PPC (Control, P20, P40 and P60 respectively). The in vitro protein digestibility of protein in PPC was 88.8%, relative to 100% protein in the FM. The in vitro protein digestibility of protein in the experimental diets also decreased with increasing PPC and was lowest at 84.2% in P60. After the 7‐week feeding trial, final body weight, weight gain and thermal growth coefficient tended to decrease with increasing PPC and were significantly lower in P60 than in the control (p < .05). Further, fish fed with diets P40 and P60 showed significantly lower feed conversion and protein efficiency ratios than the control group (p < .05). In conclusion, the results suggest that PPC can replace up to 20% of FM in the diet of greater amberjack without compromising the growth performance or feed efficiency.     

Optimum culture conditions of <Emphasis Type="Italic">Rhodomonas</Emphasis> sp. Hf-1 strain as a live food for aquatic animals

Suitable culture conditions for Rhodomonas sp. Hf-1 strain were examined for high productivity. Hf-1 strain was grown in an incubator for 7 days. The factorial experimental design investigated the following 19 variables: temperature (12, 16, 20, 24 and 28 °C), salinity (7, 14, 21, 28 and 35 psu), light intensity (20, 35, 50, 65 and 80 μmol m^?2 s^?1), light color (white, red, green and blue lights), and 3 factorial designs of photoperiod (24L:0D, 16L:8D and 12L:12D light:dark cycle). The cell density and specific growth rates (SGR) were analyzed. The best cell growth was observed under the following culture conditions: temperature of 24 °C, salinity of 21 psu, light intensity of 80 μmol m^?2 s^?1, and white light. In the photoperiod test, the highest cell density of 4.7?×?10⁶ cells ml^?1 was obtained at 24L:0D light:dark cycle, and the SGR was 0.57 μ day^?1 at this time. We found that the Hf-1 strain was able to be cultured in extremely wide culture conditions. These results are expected to serve as a baseline study for culturing the Hf-1 strain in the laboratory and for its use in aquaculture.