Relationship of glomerular filtration rate based on serum iodixanol clearance to IRIS staging in cats with chronic kidney disease

We examined the correlation between the glomerular filtration rate (GFR) estimated from an equation based on the serum iodixanol clearance technique and International Renal Interest Society (IRIS) stages of chronic kidney disease (CKD) in cats. The equation included the injection dose, sampling time, serum concentration and estimated volume of distribution (Vd) of the isotonic, nonionic, contrast medium iodixanol as a test tracer. The percent changes in the median basal GFR values calculated from the equation in CKD cats resembled those of IRIS stages 1–3. These data validate the association between the GFR derived from the simplified equation and IRIS stages based on the serum creatinine concentration in cats with CKD. They describe the GFR ranges determined using single-sample iodixanol clearance for healthy cats and cats with various IRIS stages of CKD.     

Resveratrol Improves the Mitochondrial Function and Fertilization Outcome of Bovine Oocytes

The aim of the present study was to address the effect of resveratrol-mediated upregulation of sirtuin 1 (SIRT1) during oocyte maturation on mitochondrial function, the developmental ability of oocytes and on mechanisms responsible for blockage of polyspermic fertilization. Oocytes collected from slaughterhouse-derived ovaries were cultured in TCM-199 medium supplemented with 10% FCS and 0 or 20 µM resveratrol (Res). We examined the effect of Res on SIRT1 expression in in vitro-matured oocytes (Exp 1); fertilization and developmental ability (Exp 2); mitochondrial DNA copy number (Mt number), ATP content and mitochondrial membrane potential in matured oocytes (Exp 3); and the time required for proteinase to dissolve the zona pellucida following in vitro fertilization (as a marker of zona pellucida hardening), as well as on the distribution of cortical granules before and after fertilization (Exp 4). In Exp 1, the 20 µM Res treatment upregulated protein expression of SIRT1 in oocytes. In Exp 2, Res treatment improved the ratio of normal fertilization and the total cell number of blastocysts. In Exp 3, Res treatment significantly increased the ATP content in matured oocytes. Additionally, Res increased the overall Mt number and mitochondrial membrane potential, but the effect was donor-dependent. In Exp 4, Res-induced zona hardening improved the distribution and exocytosis of cortical granules after in vitro fertilization. In conclusion, Res improved the quality of oocytes by improving mitochondrial quantity and quality. In addition, Res added to the maturation medium enhanced SIRT1 protein expression in oocytes and improved fertilization via reinforcement of the mechanisms responsible for blockage of polyspermic fertilization.     

The effect of experimental inhibition of gastric acid secretion on curd formation in abomasum and weight gain of calves

Eight Holstein bull calves were divided into two groups; a non-treated control group and a famotidine treated group. Fresh milk was fed twice a day. The experiment was conducted between 7 and 14 days of age. During the experimental period the control group was injected with physiological saline, and the famotidine group was injected with famotidine, a histamine-H2-receptor blocker, into the jugular vein 30 minutes prior to each feeding. The control group showed maximum curd formation 2 h after feeding at both 7 and 14 days of age. Curd scores of 7-day-old and 14-day-old calves were significantly lower in the famotidine than in the control group at 2 and 4 h after feeding. Most fecal samples from the famotidine group exhibited an acidic smell. The famotidine group showed significantly lower values for both average weight gain and the rate of weight gain from 7 to 14 days of age. The inhibition of gastric acid secretion decreased curd formation in the abomasum as well as daily weight gain compared to non-treated control calves. This suggested that curd formation in the abomasum is important for the weight gain of newborn calves.     

Involvement of vascular endothelial growth factor in the formation of the thecal layer and vasculature during follicular development in the ovaries of neonatal female rats

Vascular endothelial growth factor (VEGF) is an important angiogenic factor in the ovary, but the localization of VEGF in the ovary of neonatal animals is poorly understood. A clear understanding of the relationship between the formation of the thecal layer and the cell‐specific expression of the VEGF system during follicular development in the neonatal ovary is still lacking. Immature female Wistar‐Imamichi rats used in this study were killed by decapitation 5, 7, 9 and 11 days after birth, and their ovaries were removed and subjected to histological and immunohistochemical observation. The number of primordial follicles had decreased in the ovaries at day 11 compared with that at day 5. The number of secondary follicles significantly increased with age. In the morphological observation of secondary follicles, we found that the theca layer (70 µm in diameter of follicles) began to form at day 9 and was completely formed at day 11. An endothelial cell marker, CD31, VEGF and Flk‐1 were located in the stromal tissues in the ovaries on each day examined after birth. In particular, in the ovaries at day 9 and day 11, when the secondary follicles appeared, CD31, VEGF and Flk‐1 were expressed in the theca layer. Flt‐1 was expressed in the oocytes of the ovaries at day 5 and day 7, and the sites of its expression changed to stromal and thecal tissues at day 9 and day 11. In conclusion, we provide the first evidence that the theca layer of secondary follicles begin to form at day 9 after birth and that VEGF and Flk‐1 may be able to stimulate the differentiation of stromal‐interstitial cells into thecal cells and the formation of the thecal vasculature in the neonatal rat ovaries, suggesting that the VEGF system may be involved in the formation of the thecal layer and vasculature during folliculogenesis in the neonatal rat.     

Effects of fat coated rumen bypass lysine and methionine on performance of dairy cows fed a diet deficient in lysine and methionine

Two experiments were conducted to evaluate the effect of fat coated rumen bypass lysine (RPLys) and methionine (RPMet) on the lactation performance of dairy cows. In Experiment 1, three lactating cows were supplied with RPLys and fat coated DL‐Met which was highly protected (H‐RPMet) as an indigestible marker, and total fecal emission was collected for 72 h following administration. Measuring the proportional difference in fecal excretion of lysine derived from RPLys relative to methionine derived from H‐RPMet, the intestinal availability of RPLys was estimated to be 66.2%. In Experiment 2, 20 multiparous Holstein cows producing approximately 40 kg/day of milk were assigned to two treatments; fed RPLys (16 g/day as lysine) and RPMet (6.5 g/day as methionine) or none (control) from 5 to 21 weeks postpartum. The consumption of dry matter, organic matter, crude protein, neutral detergent fiber and acid detergent fiber were significantly more in the control cows throughout the experimental period. Their milk protein yield, the contents of their milk protein and milk fat were higher by 0.03 kg (P = 0.03), 0.06% (P < 0.001) and 0.11% (P = 0.07), respectively, in the treatment group compared to the control. These results suggest that the RPLys and RPMet used in this study improved the lactation performance of dairy cows.     

Taxonomic Position of the Causal Pathogen of Bacterial Shoot Blight of Pear

Bacteriological properties and DNA-DNA homology values were compared among the pathogen causing bacterial shoot blight of pear (BSBP) isolated in 1994–1996, Erwinia amylovora isolated outside of Japan, and other Amylovora group bacteria. Bacteriological properties of BSBP strains were identical to those of E. amylovora in the majority of tests, but differed distinctively in several tests, including hydrolysis of esculin and acid production from salicin, etc. BSBP strains differed from the others in the Amylovora group in many other tests. DNA homology among the strains of BSBP ranged from 85 to 103% and from 83 to 110% among strains of E. amylovora. In contrast, the values between BSBP strains and E. amylovora strains were 55 to 81%, while those between BSBP strains and other Amylovora group strains were 42% or less. We consider, therefore, that the BSBP pathogen may well be included in E. amylovora at the species level. E. amylovora, including BSBP strains, however, can be classified into four biovars based on differences in nine tests such as growth factor requirements and crater formation on high sucrose medium. Namely, there are two biovars from Maloideae sources, one from Rubus idaeus, and one from the source of BSBP in Hokkaido. The presence of these biovars suggests a correlation with geographical, serological, and pathogenic differentiations in the species of E. amylovora. The BSBP pathogen in Hokkaido was identified as E. amylovora bv. 4 which is distinct from E. amylovora bv. 1, 2 and 3 isolated in countries outside of Japan. Received 29 July 1999/ Accepted in revised form 12 October 1999     

Notes on the Occurrence of Pathogenic Races of <Emphasis Type="Italic">Xanthomonas oryzae </Emphasis>pv. <Emphasis Type="Italic">oryzae </Emphasis>Found in Hiroshima Prefecture in 1999

The pathogenic race of 59 cultures of Xanthomonas oryzae pv. oryzae, a pathogen of bacterial leaf blight of rice, isolated from six locations in the inland mountainous area of Hiroshima Prefecture in 1999, were determined by a set of traditional differentials. Four races—I, II, V and VII—were found across the area; however, we noticed the composition of the races as well as the dominant race in each location different. All races were avirulent on differential cultivar Te-tep. Races V and VII were new to Hiroshima. The rice cultivars infected with bacterial leaf blight in Hiroshima are thought to be grouped into the Kinmaze group, which does not have any resistance genes. Apparently, a variety of races occurred unexpectedly on the cultivars contrary to stabilizing selection theory. Received 25 February 2000/ Accepted in revised form 13 July 2000