菜用大豆与普通大豆未成熟子粒硬度与结构研究

测定了7个菜用大豆与7个普通大豆品种未成熟鲜子粒经不同热烫时段后的硬度,并通过冷冻切片、显微技术比较了其结构上的差异性.结果表明:菜用大豆与普通大豆在种皮栅栏细胞层厚度上的差异不大,但菜用大豆栅栏细胞层密度(33.13个/mm2)显著高于普通大豆(29.50个/mm2);菜用大豆滴漏细胞层厚度(99.64μm)极显著大于普通大豆(57.94μm);而普通大豆子叶细胞层密度高于菜用大豆,且二者在内层细胞排列密度上的差异性达到了极显著水平.菜用大豆硬度(平均549.3gf)明显小于普通大豆(平均608.4gf),且热烫时两种类型大豆硬度降低的规律不同,菜用大豆在热烫3～6min时,硬度降低速率(48.99gf/min)最大,此前此后较小;而普通大豆在3-6min时,硬度降低速率(11.67gf/min)最小,此前此后却较大,这可能与它们在子粒结构上的差异性有关.此研究将未成熟大豆硬度和子粒宏观结构联系起来,对菜用大豆食味品质的基础性研究与菜用大豆速冻加工前的热烫工艺研究上都有一定意义.     

Sarcoplasmic Reticulum Ca2+-ATPase Activity and Glycogen Content in Various Fiber Types after Intensive Exercise in Thoroughbred Horses

To find a new parameter indicating muscle fitness in Thoroughbred horses, we examined time-dependent recovery of glycogen content and sarcoplasmic reticulum (SR) Ca²⁺-ATPase activity of skeletal muscle after intensive treadmill running. Two repeated 50-sec running sessions (13 m/sec) were performed on a flat treadmill (approximately 90%VO₂max). Muscle samples of the middle gluteal muscle were taken before exercise (pre) and 1 min, 20 min, 60 min, and 24 hr after exercise. Muscle fiber type composition was determined in the pre muscle samples by immunohistochemical staining with monoclonal antibody to myosin heavy chain. SR Ca²⁺-ATPase activity of the muscle and glycogen content of each muscle fiber type were determined with biochemical analysis and quantitative histochemical staining, respectively. As compared to the pre value, the glycogen content of each muscle fiber type was reduced by 15–27% at 1 min, 20 min, and 60 min after the exercise and recovered to the pre value at 24 hr after exercise test. These results indicate that 24 hr is enough time to recover glycogen content after short-term intensive exercise. The mean value of the SR Ca²⁺-ATPase activity showed a slight decrease (not significant) immediately after exercise, and complete recovery at 60 min after exercise. There were no significant relationship between the changes in glycogen content of each muscle fiber type and SR Ca²⁺-ATPase. Although further studies are needed, SR Ca²⁺-ATPase is not a useful parameter to detect muscle fitness, at least in Thoroughbred horses.     

Lesions in the Larynx of Wistar RccHan: WIST Rats

Specific regions in the rat larynx exhibit cellular changes in response to inhaled xenobiotics. These regions include the base of the epiglottis, ventral pouch, and medial surfaces of the vocal processes of the arytenoid cartilages. 1 , 2 In order to collect information on the usefulness of trimming techniques, the influence of different vehicles, the impact of different application routes in toxicity studies, and differences between induced vs. spontaneous lesions, the data obtained from a large number of inhalation and non-inhalation studies performed in Wistar RCCHan(TM): Wist rats at Harlan Laboratories Ltd Switzerland, all evaluated or reviewed by the same pathologist, were compiled for a detailed review. The value of different trimming techniques was deemed to be greatest for transverse and sagittolongitudinal section techniques, as compared to horizontolongitudinally section techniques. The comparison of lesions encountered in control rats of inhalation studies treated with different vehicles did not reveal differences in the type, distribution pattern, incidence and/or severity of spontaneous lesions. The types of lesions were also independent of different application routes in non-inhalation studies compared to inhalation studies. The pattern of spontaneous lesions in the rodent larynx was determined by degenerative and inflammatory lesions starting most often in the submucosal glands by desiccated secretion followed by mineralization and local inflammation or were induced by impacted foreign bodies. Squamous metaplasia was recorded in the respiratory epithelium overlaying the ventral gland as a spontaneous lesion in male Wistar rats from inhalation studies with a maxim of 20.0% in an inhalation oncogenicity study. Induced metaplastic changes recorded in the larynx were reversible. Other induced lesions in inhalation studies consisted of submucosal edema, necrosis, inflammation and/or granuloma. Induced lesions in non-inhalation studies were found to be exclusively related to reflux laryngitis or food impaction. It is concluded, that in rodents induced lesions of the larynx differ in type, distribution pattern, severity and incidence from spontaneous lesions.     

Pathological and phylogenetic features of prevalent canine distemper viruses in wild masked palm civets in Japan

Ten wild masked palm civets infected with canine distemper virus (CDV), captured in Japan from 2005 to 2007, were histopathologically and phylogenetically analyzed. Phylogenetic analysis based on the amino acid sequences of the H protein of two CDV isolates from masked palm civets revealed that the two isolates were classified into the clade of recent isolates in Japan. Histopathologically marked lesions of virus encephalitis were present in the brain, whereas gastrointestinal lesions were absent or at a mild degree. The distribution of the lesions resembles that of recent CDV cases in dogs. Therefore, recent CDV infections in masked palm civets could be caused by recently prevalent CDV in dogs. The possibility of the masked palm civet as a spreader of CDV among wildlife is also discussed.     

Origin of Clostridium perfringens isolates determines the ability to induce necrotic enteritis in broilers

Since the ban on growth-promoting antibiotics in animal feed in the European Union, necrotic enteritis has become a major cause of mortality in broiler chickens. Despite the importance of the disease, the pathogenesis is still not completely understood. In the current study, Clostridium perfringens strains isolated from healthy flocks and isolates from outbreaks of necrotic enteritis were evaluated for the ability to cause gut necrosis in an intestinal loop model in laying hens and in an experimental infection model in broilers. High, intermediate and low alpha toxin producing strains were chosen from each isolation source. Only the isolates from field outbreaks induced necrotic gut lesions, independent of the amount of alpha toxin produced in vitro. It was also shown that alpha toxin producing isolates from calf hemorrhagic enteritis cases were not able to induce necrotic enteritis in poultry. These results suggest the presence of host specific virulence factors in C. perfringens strains, isolated from chickens with intestinal necrotic enteritis lesions.     

Differential responses of cells from human skin keratinocyte and bovine mammary epithelium to attack by pore-forming Staphylococcus aureus alpha-toxin

Human skin keratinocytes HaCat attacked by Staphylococcus aureus α-toxin showed a transient drop of cellular ATP levels whereas in toxin-perforated bovine mammary epithelial cells (BMEC), the ATP levels dropped more slowly. Morphologically, during the ATP level depletion, HaCat cell developed a spacious intracellular vacuole together with the transient influx of trypan blue. WST-1 signal, which tested the function of mitochondrial enzyme in viable cells, also decreased concomitantly. On the other hand, BMEC excluded trypan blue and vacuolation was not observed throughout the experiment. We conclude that mammary epithelial cells resist the toxin better than keratinocytes. This is the first report showing that α-toxin enhances transient membrane permeability to large molecules, temporary vacuole formation and the transient defect of mitochondrial enzyme in viable cells without cell lysis.     

Cloning, nucleotide sequence and phylogenetic analyses, and tissue-specific expression of the transferrin gene in Cirrhinus mrigala infected with Aeromonas hydrophila

Transferrin partial complementary DNAs were cloned from the livers of five species in four genera of Indian carps (Indian major carp species: Labeo rohita, Catla catla and Cirrhinus mrigala; medium carp: Puntius sarana; minor carp: Labeo bata) subsequent to polymerase chain reaction amplification with published heterologous primers or self-designed primers derived from conserved regions of transferrin cDNA sequences. The partial transferrin cDNAs of the five species of carps had sizes from 624 to 633 bp (487 bp for L. rohita) and encoded an open reading frame consisting of 206–211 (162 for L. rohita) amino acids. The alignments of carp cDNA sequences showed 85–97% homology and 71–93% homology in deduced amino acid sequences. A phylogenetic tree of amino acid sequences of transferrin cDNAs from carps showed that the relationship among the four genera of Indian carps is well correlated with that derived from classic morphologic analyses. The hypothesized cleavage site and interdomain bridge of transferrin molecule were predicted for the above carp species and interestingly the cleavage site amino acid sequence was found to be conserved among all the carps. To study the tissue-specific expression of the transferrin gene, various tissues (liver, kidney, spleen, brain, muscle, testis, heart, intestine, gill and fin) from apparently healthy (control), moribund and survived C. mrigala experimentally infected with Aeromonas hydrophila infection were analyzed. Transferrin mRNA was detected only in liver RNA and to lesser extent in brain tissue out of the 10 tissues analyzed irrespective of bacterial infection.     

Comparison of Multistix PRO dipsticks with other biochemical assays for determining urine protein (UP), urine creatinine (UC) and UP:UC ratio in dogs and cats

BACKGROUND: Urine protein: urine creatinine (UP:UC) ratio determined from the quantitative measurement of protein and creatinine in a single urine sample is the best feasible assessment of clinically significant proteinuria in dogs and cats. A dipstick that measures urine protein, urine creatinine, and UP:UC ratio has been used in human medicine and could have application for veterinary practice. OBJECTIVE: The objective of this study was to compare the Multistix PRO dipstick (Bayer Corporation, Elkhart, IN, USA) to other biochemical methods for determination of urine protein and creatinine, and UP:UC ratio in canine and feline urine. METHODS: A complete urinalysis, including sulfosalicylic acid (SSA) precipitation, was performed on urine samples submitted to our laboratory between February and April 2003 from 100 dogs and 49 cats. Urine protein and creatinine concentrations were determined by the Multistix PRO dipstick using a Clinitek 50 analyzer (Bayer) and compared with the results of SSA precipitation and quantitative biochemical analysis. The UP:UC ratios from the dipstick results (calculated by the Clinitek 50 and also manually) were compared with those calculated from quantitative values. Pearson product-moment correlation analysis and diagnostic sensitivity and specificity (using quantitative results as the gold standard) were determined. RESULTS: For both canine and feline urine, protein and creatinine concentrations determined by the Multistix PRO correlated closely with quantitative concentrations for protein (dogs r = .78, P = .0001; cats r = .87, P = .0001) and creatinine (dogs r = .78, P = .0001; cats r = .76, P = .0001). The Multistix PRO was more sensitive and less specific than SSA precipitation for diagnosing clinically significant proteinuria. UP:UC ratios obtained by manual calculation of dipstick results correlated best with quantitative UP:UC ratios in dogs, and had higher specificity but lower sensitivity for the diagnosis of proteinuria. In cats, UP:UC ratios determined by the dipstick method did not correlate (r = -.24, P = .0974) with quantitative values. CONCLUSIONS: The Multistix PRO, with manual calculation of UP:UC, may be a good alternative for the diagnosis of clinically significant proteinuria in dogs, but not cats. Dipstick creatinine concentration should be considered as an estimate.     

人参中人参多糖检测方法研究

目的测定人参中人参多糖的含量,并建立人参多糖的含量测定方法。方法采用紫外分光光度法,苯酚-浓硫酸比色法于波长486nm处测定吸光度。结果人参多糖含量为13.31g/100g,标准曲线的线性范围为0.9991~0.9998,平均加样回收率为98.2%,RSD=2.23%。结论苯酚-浓硫酸比色法测定人参中多糖含量,方法简便、准确、稳定性好。