Effect of volume of non-surgical embryo transfer medium on ability of porcine embryos to survive to term

Non-surgical embryo transfer is a promising method for improving efficiency in the pork industry and also for biotechnology applications, such as in vitro embryo production, transgenesis and cloning. Several groups have reported successful piglet production using an artificial insemination catheter or flexible catheter designed for this procedure; however, the efficiency of the technique is still low. The critical points that need to be addressed in order to improve this procedure are (1) the embryo deposition site and (2) volume of transfer medium associated with the embryos; however, the latter has not yet been examined systematically. In the present study, we evaluated the effect of the volume of non-surgical embryo transfer medium on the ability of porcine embryos to survive to term by using a recently produced flexible catheter. The catheter consists of a guide and an injector. Blastocysts 200-230 mum in diameter were collected from donor gilts and transferred to recipient gilts. The time required for the completion of embryo transfer using this catheter was 14.6 +/- 3.9 min. The tip of the injector was determined by laparotomy to be located in a uterine horn 20-30 cm anterior from the branching point of the uterus body. We transferred 17.0-17.3 embryos with different volumes of medium (1.6, 3.2 and 10 ml) into each of 5, 4 and 4 recipients, respectively, and pregnancy was confirmed in 4, 3 and 1 of these recipients, respectively. Three recipients in the 1.6 ml group farrowed a total of 19 piglets (4, 5 and 10 piglets, respectively). These results suggest that successful non-surgical embryo transfer is affected by the volume of transfer medium.     

Quantitative structure–fungicidal activity relationships of N-(4-difluoromethoxybenzyl)­pyrimidin-4-amines against wheat and barley fungi

A set of N-(4-difluoromethoxybenzyl)pyrimidinamines with various substituents at the 4- and 5-positions of the pyrimidine ring and at the benzyl position were prepared, and their fungicidal activities against wheat brown rust, Puccinia recondita, and barley powdery mildew, Erisiphe graminis, were measured. Variations in each of these activities were quantitatively analysed by the use of physicochemical substituent parameters and a regression analysis. Each of these activities was parabolically correlated with the steric bulkiness of the pyrimidine substituents and with the bulkiness or the hydrophobicity of the benzylic substituents. © 1999 Society of Chemical Industry     

Drying and anatomical characteristics of sugi wood attacked by bacteria during pond storage

Seven species of bacteria were isolated and identified from ponded sugi (Cryptomeria japonica D. Don) logs, and six species showed potent wood-degrading activities. To evaluate the effects of these isolated bacteria on the drying and anatomical characteristics of wood, small fresh blocks of sugi were immersed in water suspensions containing bacteria for 1–7 months. The permeability and drying properties were evidently improved. Most of the encrusting substances adhering to the cell lumens and the pit chambers were removed, and the pit membranes were destroyed. These anatomical changes due to bacterial activity were assumed to improve the permeability of sugi wood.Part of this report was presented at the 40^th annual meeting of the Japan Wood Research Society, Tsukuba, April 1990; the 41^st annual meeting of the Japan Wood Research Society, Matsue, April 1991; and the IUFRO XX World Congress, Tampere, August 1995     

Inhibition of acetate ester biosynthesis in banana (Musa sapientum L.) fruit pulp under anaerobic conditions

The effect of anaerobic conditions on acetate ester biosynthesis in ripened banana pulp was investigated. Incubation of the pulp in less than 1% O(2) resulted in a significant reduction in the formation of ethyl acetate. Regardless of the presence of a large amount of endogenous ethanol and the remaining exogenous isobutyl alcohol after complete anaerobic incubation with the pulp, the production of acetate ester decreased. The effect of addition of pyruvate, isobutyl alcohol, acetate, and methyl hexanoate on acetate ester formation in 100% N(2) was also investigated. The addition of pyruvate and isobutyl alcohol to the pulp gave lower acetate esters in N(2) than in air, whereas the pulp incubated with acetate and isobutyl alcohol produced more acetate ester in both conditions. Therefore, the lack of acetyl CoA, or more precisely acetate, in the tissue is the main reason for the inhibition of acetate ester formation under anaerobic conditions. The activity of beta-oxidation measured by incubation with methyl hexanoate was detected only in the samples incubated in air. The formation of acetyl CoA, derived from pyruvate through mitochondria and through beta-oxidation, was inhibited by anaerobic conditions, which suggests that mitochondrial activity and/or beta-oxidation are essential for ester biosynthesis.     

中后期追施15N对水稻氮素积累与分配的影响

在田间条件下 ,采用 1 5 N微区法 ,研究中、后期施肥对稻株体内氮素积累与分配的影响。结果表明 :1随着氮肥施用时期的推迟 ,茎、叶等营养器官干物重明显下降 ,而穗干物重下降幅度较小 ,且其占全株干重的比例提高。 2稻株含氮率随氮肥施用时期推迟有提高的趋势 ;与施促花肥相比 ,施用粒肥绿叶及叶鞘中的氮素积累量明显下降 ,而茎、穗中氮累积量则略有增加。 3在稻株不同器官中 ,穗、绿叶 (包括叶鞘 )对穗粒肥氮的积累能力最强 ,但随穗粒肥施用时期的推迟 ,穗部积累的肥料氮及其占全株的比例增加 ,而绿叶则呈相反的趋势。 4稻株对促花肥、保花肥、粒肥氮的回收率 (利用率 )分别为 32 .7%、30 .0 %及 2 3.7%。     

Molecular Monitoring of hrpB-disrupted Mutant of Ralstonia solanacearum in Tomato Plants

A nonpathogenic mutant of Ralstonia solanacearum was produced by the insertion of transposon Tn4431. The mutagenized gene was then cloned from a genomic DNA library by the gene tagging method, using the labeled lux operon located on Tn4431 of pUCD623 as a hybridization probe. From nucleotide sequence analysis of the transposon-inserted genomic clone, the hrpB gene was shown to be disrupted by the inserted transposon. Tomato plants were inoculated with the hrpB-disrupted mutant bacteria, for which multiplication and translocation were then monitored using the colony hybridization method. In addition, the original pathogenic bacteria in which the lux operon had been functionally ligated with the genomic promoter were also used for inoculation and traced by their bioluminescence. Multiplication of the hrpB-disrupted mutant was suppressed initially in the invaded root tissues and then in upper hypocotyl after translocation, suggesting that the pathogenic strain of R. solanacearum overcomes at least two steps of host responses expressed in root and hypocotyl tissues. Thus, our approach for molecular monitoring of the bacteria enabled us to precisely analyze the infection behavior of the pathogenic bacteria in planta. Received 16 April 1999/ Accepted in revised form 10 August 1999     

Evaluation of Single-Incision Laparoscopic Ovariectomy in Standing Mares

Our objective was to compare the invasiveness of single-incision laparoscopic surgery (SILS) and multiport laparoscopic surgery (MLS) for ovariectomy in 5 standing healthy adult Thoroughbred mares. First, laparoscopic ovariectomy was performed by SILS or by MLS on the right paralumbar fossa region in a standing mare. One month after surgery, ovariectomy by the other method was performed on the left side. For surgery evaluation, the surgical time, length of incision, and amount of lidocaine used were recorded and compared between SILS and MLS. Physical examination (body temperature, heart rate, and respiration rate) and hematology (number of leukocytes and hematocrit) were performed before surgery and every day for 7 days after surgery. Similarly, the degrees of swelling, heat, pain, and incisional wound healing were evaluated (grades1-4). The length of incision and amount of local anesthetic for SILS were significantly less than those for MLS. Moreover, the scores for swelling, heat, and pain in the SILS group tended to be lower than those in the MLS group for several days after surgery. We concluded that SILS was less invasive than MLS and is therefore useful for ovariectomy in mares.     

Macroscopic separation of dense fluid phase and liquid phase of phosphorus

Structural transformation between a dense molecular fluid and a polymeric liquid of phosphorus that occurred at about 1 gigapascal and 1000 degrees C was investigated by in situ x-ray radiography. When the low-pressure fluid was compressed, dark and round objects appeared in the radiograph. X-ray diffraction measurements confirmed that these objects were the highpressure liquid. The drops grew and eventually filled the sample space. Decompressing caused the reverse process. The macroscopic phase separation supported the existence of a first-order phase transition between two stable disordered phases besides the liquid-gas transition. X-ray absorption measurements revealed that the change in density at the transition corresponds to about 40% of the density of the high-pressure liquid.     

Orbital malignant schwannoma and embryonal rhabdomyosarcoma in rats caused by leakage of locally injected nickel subsulfide to the orbit

Nickel subsulfide (Ni₃S₂) is known to induce intraocular neoplasms when injected intravitreally into the eyes of rats. Here, we found two extraocular orbital neoplasms in two different rat strains, presumably due to the leakage of locally injected Ni₃S₂ to the extraocular orbital tissues. In the F344/DuCrlCrlj rat, an orbital mass arose at 30 weeks after injection, and invaded into the cranium. Histologically, the orbital mass was composed of areas arranged in parallel bundles formed by densely packed elongated or spindle-shaped cells with indistinct cytoplasmic borders, and of areas of hypocellular arrangement consisting of round cells in eosinophilic myxoid-like substances. Metastases were observed in the right submandibular and cervical lymph nodes. The neoplastic cells were immunopositive for S-100 protein and vimentin. Transmission electron microscopy revealed that the neoplastic cells had cellular processes and pericytoplasmic basal laminae. In the RccHan^TM:WIST rat, an orbital mass arose at 36 weeks after injection. Histologically, the mass consisted of rhabdoid-like large round cells with proliferation of small round-to-polygonal cells, and these neoplastic cells infiltrated into the extraocular muscles. Immunohistochemically, the neoplastic cells were positive for desmin and vimentin. Transmission electron microscopy detected immature myofibrils with Z-band structures in the cytoplasm of these neoplastic cells. Consequently, the tumors were diagnosed as an orbital malignant schwannoma in an F344/DuCrlCrlj rat and an orbital embryonal rhabdomyosarcoma in a RccHan^TM:WIST rat. The results of this case report suggest that leakage of Ni₃S₂ to the orbit caused the induction of orbital malignant schwannoma or rhabdomyosarcoma in rats.