In vitro development of bovine nuclear transfer embryos reconstructed with mammary gland epithelial cells at different passages

In the present study, the effect of passage of nuclear donor cells on the in vitro development of nuclear transfer (NT) embryos was investigated using colostrum‐derived mammary gland epithelial (MGE) cells at different passages (3–30 passages) to find reliable passages for the efficiency of cloning. Development of NT embryos to the blastocyst stage was affected by the number of passages of MGE cells (P < 0.05). Nuclear transfer embryos reconstructed with MGE cells at 3–7 passages showed a significantly higher blastocyst development (31.3–48.5%) than those with the cells at 10–30 passages (2.5–12.5%, P < 0.05). No difference in the proportion of the MGE cells with normal diploid was observed among passage of 3, 15 and 30 (P > 0.05). The use of MGE cells at early passages for nuclear donor cells may be advantageous for the production of NT embryos.     

Concentrations of toxic metals and essential minerals in the mane hair of healthy racing horses and their relation to age

Concentrations of trace elements (As, Al, Pb, Cd, Hg, Se, Si, P, Na, K, Ca, Mg, Fe, Cu, Zn, Mn, Cr, Ni and Mn) in the mane hair obtained from 9 female and 15 male healthy racing Thoroughbred horses aged 2-5 years were analyzed by the inductively coupled plasma atomic emission spectrometry (ICP-AES) method. No significant differences between the female and male horses were observed in the mean concentrations of those minerals. Significantly positive correlations with age were observed in Cd (r=0.546, p<0.01) and Mo (r=0.733, p<0.001). Significantly negative correlations with age were observed in Hg (r= -0.726, p<0.001), Mn (r= -0.450, p<0.05) and Fe (r=-0.642, p<0.01). This reference range of trace elements in the mane hair of racing horses should be used to assess disease and the nutritional status in equine practice.     

Identification and characterization of rhizobacteria isolated by enrichment culture on spinach roots

Rhizobacteria can be used for biological control and environmental restoration. In this study, we performed enrichment culture of rhizobacteria, identified isolates, and investigated the physiological properties of the bacterial isolates. Five bacteria differing in their colony morphology were isolated from spinach roots as enriched rhizobacteria. Four isolates were identified by sequencing of 16S rDNA as β and γ-Proteobacteria; 16S rDNA sequencing was not completed on one isolate. Based on microscopic observation, we determined that at least two types of bacteria differing in their morphology co-existed in this isolate, and that it may not be possible to culture the two types separately. Based on tests of substrate utilization, we could not find the characteristics that were common to the isolates. One of the five isolates was inoculated into non-sterile soil, and we examined its root-colonizing ability. The test strain which was not detected in the non-rhizosphere soil, accounted for about 20% of the total bacteria on the roots. These results suggested that enrichment culture might be useful for isolating bacteria with a high root-colonizing ability     

Studies on the properties of organic matter in buried humic horizon derived from volcanic ash

Abstract

Humic acids were extracted from the surface horizon Yu 1 and buried humic horizons (Yu 2, 800-864 AD; Yu 4, ca. 4,000 years B.P.; Yu 6, 7,000 years B.P.; Yu 7, ca. 10,000 years B.P.). The humic acids were filtered with ultramembranes with 20, 10, 5, 1 or 0.1 × 10' M.W. in this order and separated into five fractions; (>20), (20-10), (10-5), (5-1) and (1-0.1) × 10⁴ M.W. fractions. The elementary composition, functional groups, optical properties, and hydrolyzable total- and sugar-carbon contents of each humic acid fraction were determined, and the changes in properties of the humic acid with age after burial were discussed.

In horizons Yu 1 to Yu 6, the patterns of M.W. distribution of the >20 × 10⁴ to (1- 0.1) × 10⁴ fractions were rather similar. In contrast, Yu 7 was characterized by the predominance of (1-0.1) x 10' M.W. fraction and the presence of a small amount of <0.1 × 10⁴ M.W. fraction.

The chemical properties of humic acid (HA) fractions of each humic horizon and their changes with age after burial were as folIows:

1) Elementary composition of HA fractions of each humic horizon was rather similar to each other. The C% and C/N ratio increased, and the H%, N% and H/C ratio decreased in all HA fractions with age.

2) Total acidity and carboxyl contents of HA fractions of Yu 1 were higher in the lower M.W. fractions. These values increased with age up to Yu 4 or Yu 6 horizons, then decreased in the Yu 6 or Yu 7 horizon. The contents of carbonyl groups in all the HA fractions which were very low in Yu 1, showed a wide range of variations in Yu 2, intermediate values from Yu 4 to Yu 6 horizons then decreased in the HA fractions of Yu 7, except for the (>20) fraction.

3) The degree of humification of the HA fractions of Yu 1 judging from the RF and \sDlogK values, tended to be higher in higher M.W. fractions, and increased in all the HA fractions with age after burial.

4) Hydrolyzable total- and sugar-carbon contents were high in the HA fractions of Yu 1 and decreased with age.

5) Changes of elementary composition, degree of humification and hydrolyzable total- and sugar-carbon contents were conspicuous from the Yu 1 to Yu 2 horizons, and less significant afterwards.

6) The 0%, C/O ratio and phenolic OH content did not show any consistent change with age after burial.     

Comparative analysis of some selected macronutrients of soil in orange orchard and degraded forests in Chittagong Hill Tracts,Bangladesh

Status of organic carbon （C）, total nitrogen （N）, available potassium （K）, calcium （Ca） and phosphorus （P） in three different depths （0-5 cm, 5-15 cm and 15-30 cm） on two hill slopes of 35% and 55% in orange orchard cultivated by the Mro tribe of Chittagong Hill. Tracts （CHTs） were evaluated and compared with those in degraded bush forests, through digging three profiles in each land use. The content of all the five nutrients was found to be higher in the soil of orange orchard than in the soil of forest. But the variation was not consistent for both the slopes. The content varied depth wise also, having the highest value in surface soil in case of both the land uses on both the slopes. A mean available K content was significantly higher in orange orchard than in forest on 55% slope, while it was lower on 35% slope. Surface soil contained the nutrients of K and Ca with the amount of 0.2905-mg·g^-1 soil and 3.025-mg·g^-1 soil respectively in the orchard, while 0.1934-mg·g^-1 soil and 1.6083-mg·g^-1 soil were respectively in the forest. Organic carbon and total nitrogen were found more or less similar in surface soil on both the land uses showing a slight difference. Available P was found only in orange orchard, and in forest it was too little in amount to detect by the spectrophotometer. The degraded forests were poor in nutrient content due to high rate of soil erosion, which would be possible to be improved by bringing it under tree cover as proved by the adaptation of orange orchard there.     

Similarities and differences in meat consumption patterns in Asia and Pacific-Rim countries

This study investigated consumer behavior towards meat across Asia and Pacific-Rim countries. Mail surveys were undertaken in 1994 and 1995. Data was obtained from 6197 households in Japan, the USA (mainland and Japanese–Americans in Hawaii), Australia, Thailand, Korea, Taiwan and China. The data were mainly analyzed using cluster analysis to determine the distance between each country and to classify countries into groups. Japanese respondents purchased beef more frequently than respondents from other countries. The average amount purchased on each occasion was far more for Australian respondents than for respondents from other countries, while Japanese purchased far less. Respondents in Japan, Korea, China and Australia thought beef was the most expensive meat, whereas lamb was thought to be the most expensive in the remaining countries. Chinese respondents indicated the highest consciousness of price indexes. The level of uneasiness about eating meat indicated by Asian respondents was relatively strong compared with respondents in Hawaii, the USA and Australia. Average ratings (semantic differential scale) on plans for future meat consumption were higher for beef than for other meats in Korea and China, whereas chicken was rated higher in the other countries. From the dendrogram, surveyed countries were classified into three groups: Japan, Taiwan and Korea; Thailand and China; and the USA, Japanese–Americans and Australia. Among them, the first and second clusters merged into a larger cluster, the 'Asian' group.     

Comparison of glycerol, lactamide, acetamide and dimethylsulfoxide as cryoprotectants of Japanese white rabbit spermatozoa

The rabbit is considered to be a valuable laboratory animal. We compared glycerol, lactamide, acetamide, and dimethylsulfoxide (DMSO) as cryoprotectants in egg-yolk diluent of ejaculated Japanese white rabbit spermatozoa for improvement of sperm cryopreservation methods. Rabbit semen was frozen with 1.0 M glycerol, lactamide, acetamide, or DMSO in plastic straws. Forward progressive motility and plasma membrane integrity of the post-thaw spermatozoa were examined. The rate of forward progressive motile spermatozoa in lactamide (37.8 +/- 3.0%) was significantly (P<0.05) higher than in glycerol (17.0 +/- 3.3%). In addition, the rates of sperm plasma membrane integrity in lactamide and acetamide (35.9 +/- 3.3% and 30.2 +/- 3.0%, respectively) were significantly (P<0.05) higher than in glycerol (17.0 +/- 2.6%). The results indicate that 1.0 M lactamide and acetamide have higher cryoprotective effects than 1.0 M glycerol for cryopreservation of Japanese white rabbit spermatozoa.     

Characterisation of the carboxylesterase enzyme cauxin in the seminal fluid of the cat

The carboxylesterase cauxin is a major urinary protein in cats that is also found in seminal fluid (SF). This study investigated cauxin in feline SF including biochemical features, concentration, distribution and gene expression in epididymal tissue, and its reaction with acylglycerol substrates.Monomeric, dimeric, and/or multimeric forms of cauxin carrying N-glycosylations were detected on Western blots of feline SF but most were monomeric. Cauxin concentrations were markedly lower in SF (0.042 ± 0.020 mg/mL) than in urine (∼0.5 mg/mL) and cauxin gene expression was 60-fold lower in the epididymis than in the kidney. Immunohistochemical examination localised cauxin within the stereocilia and cytoplasm of epithelial cells lining the caput and corpus epididymis. Cauxin-positive spermatozoa were detected in the lumen of the cauda epididymis but not in the cytoplasm of the epithelial cell lining. Using an in vitro assay, cauxin hydrolysed saturated 1-mono- but not di- and tri-acylglycerols. The results suggest that cauxin secreted from the caput and corpus epididymis acts as an esterase on lipid within feline SF.     

Pathogenesis of systemic Mycobacterium avium infection in pigs through histological analysis of hepatic lesions

Mycobacterium avium causes systemic infections through primary intestinal lesions in pigs. However, its pathogenesis is not well understood. The aim of this study was to confirm the effects on swine after enteral infection. One hundred and twelve pigs with hepatic lesions infected with M. avium were used in this study. We investigated the involvement of other organs and the distribution of hepatic lesions in the lobular structure. Most lesions involved the mesenteric lymph nodes. Hepatic lymph nodes were the secondary nodes involved. In 74 cases (66.1%), the hepatic lesions were predominantly distributed in the portal tract of the affected livers. The other 38 cases (33.9%) showed granulomatous lesions in the hepatic lobule. Many cases showed interface hepatitis. There was a significant relationship between focal lesions within hepatic lobule and splenic lesions. These findings suggest that granulomatous lesions formed in hepatic lobules upon establishment of bacteremia in pigs systemically infected with M. avium.     

Similarity between Copper Resistance Genes from Pseudomonas syringae pv. actinidiae and P. syringae pv. tomato

Twenty-eight strains of Pseudomonas syringae pv. actinidiae isolated in 1984, 1987 and 1988 from kiwifruit orchards in Japan were tested for their resistance to copper sulfate. All strains isolated in 1984 were copper sensitive with a minimum inhibitory concentration (MIC) of cupric sulfate of 0.75 mM. However, some strains isolated in 1987 and 1988 were resistant, with the MIC ranging from 2.25 to 3.0 mM. All copper-resistant strains contained at least one of two plasmids, pPaCul (about 70.5 kb) or pPaCu2 (about 280 kb), or both. In a copper-resistant strain Pa429, the location of the copper-resistance gene(s) was examined by insertional inactivation with Tn5. The MIC of copper sulfate in the copper-sensitive mutant obtained by Tn5 tagging decreased from 2.75 to 0.75 mM. The 14.5 kb BamHI fragment, designated pPaCuB14, containing the same locus mutagenized with Tn5 was cloned from pPaCu1. However, pPaCuB14 did not confer copper resistance in the transformant of copper-sensitive strain Pa21R, suggesting that this clone did not contain a full set of copper-resistance gene(s). Then a cosmid library of pPaCu1 was constructed and six cosmid clones hybridized with pPaCuB14 were selected. One of the six cosmids, designated pPaCuC1, conferred a near wild-type level of copper resistance in the transformant of the copper-sensitive strain. pPaCuC1 had a homologous region that hybridized with all of the PCR-amplifled fragments of copA, copB, copR, and copS genes of P. syringae pv. tomato. DNA sequence analysis of the homologous region revealed the existence of four open reading frames (ORF A, B, R and S) oriented in the same direction. The predicted amino acid sequences of ORF A, B, R and S had 80, 70, 97 and 95% identity with CopA, B, R and S of P. syringae pv. tomato, respectively. Received 5 July 2001/ Accepted in revised form 27 September 2001