Granulocyte responses to experimental injection of live and formalin-killed bacteria in carp (Cyprinus carpio)

The objective of the study was to investigate the dynamics of changes in number of granulocytes in bacterial infections of carp (Cyprinus carpio). Carp were inoculated with non-pathogenic or pathogenic bacteria and changes in type I (neutrophils) and type II granulocyte (basophils/eosinophils) counts in kidney, circulating blood and peritoneal cavity were assessed. After the injection of non-pathogenic bacteria (Escherichia coli), the number of type I and II cells in blood increased after 6-12h, but returned to the control level after 24-48 h. In contrast, after the injection of pathogenic bacteria (Aeromonas hydrophila), the number of type I cells initially increased followed by an increase in the number of type II cells. The peak counts of type I and II cells were at 12 and 24h after the injection, respectively. When the fish were given serial-injections of formalin-killed bacteria at 12-h intervals, the type II cells also predominantly increased and remained at high levels, following the peak count of type I cells.     

Ultrastructural and kinetic studies of copper metabolism in Bedlington Terrier dogs

The objectives of this study were to determine the time course of copper (Cu) absorption in the Bedlington Terrier (BT) dog after duodenal infusion of Cu and to determine the onset of Cu accumulation in BT puppies. At 80 minutes after infusion, Cu was present in the bile and liver at 26.1 and 2675 microg/g dry weight (dw), as compared with 598 and 224 microg/g dw, respectively, in the control. In the puppies, the mean liver Cu concentrations were 443 +/- 216 microng/g dw as compared with 54 +/- 34 microg/g dw in their controls. The BT puppies had large numbers of Cu granules in their hepatic lysosomes, with very few in the bile canaliculi. In contrast, the controls had few granules in their lysosomes and large numbers in their canaliculi. These results suggest that hepatic Cu accumulation occurs rapidly and in utero in the BT.     

Sequence comparison of the dopamine receptor D4 exon III repetitive region in several species of the order Carnivora

It was previously demonstrated that the dog dopamine receptor D4 (DRD4) gene is polymorphic in terms of the repeat number and/or order of 39- and 12-bp sequences located in the third exon. To examine whether or not the repetitive region is present in other species of the order Carnivora, the homologous region of DRD4 genes were sequenced in the gray wolf, raccoon dog, Asiatic black bear, common raccoon and domestic cat. In the family Canidae, the wolf had an identical sequence to that of the dog 447b allele, and a repetitive sequence similar to the dog DRD4 was also recognized in the raccoon dog. On the other hand, no obvious repeated structure was observed in the sequences of the bear, raccoon and cat.     

Survival of Yersinia enterocolitica in soil and water.

Yersinia enterocolitica O3, O4, O5A, O5B, O6, O6, 30, O9 and O13 and Yersinia intermedia were examined to clarify their survival in natural soil, river water and well water. The O3 strain disappeared most rapidly from soil at both temperature of 4 degrees C and 20 degrees C and from river water at 20 degrees C. Although the O5B and O9 strains disappeared before the O3 strain did from river water at 4 degrees C, the O9 strain survived as long as non-virulent strains did in soil at 4 degrees C. The O3, O5B and O9 strains survived longer at 4 degrees C than at 20 degrees C in soil and river water. Non-virulent strains of O4, O5A and O6 survived longer in well water than in soil and river water. Although the O3 and O5A strains disappeared from supernatant filtered with 100 microns and 5 microns pore size filters, they maintained their viable cell numbers in supernatant of soil filtered with 0.22 microns pore size filter and in the autoclaved supernatant.     

Abortion in Japanese cows caused by Chlamydia psittaci.

An outbreak of abortion in cows occurring in Niigata Prefecture was shown to be caused by Chlamydia psittaci. Elementary bodies characteristic of Chlamydia were found in the liver of aborted fetuses and C. psittaci antigen was demonstrated by indirect immunofluorescence. Chlamydia was isolated from the liver of aborted fetuses by the yolk sac inoculation of developing chick embryos and by the intraperitoneal inoculation of guinea pigs. Abortion occurred mostly in middle or late pregnancy. Aborted fetuses showed subcutaneous edema and gelatinous infiltration, enlarged liver and spleen, and dark red pleural and ascitic fluid. Focal necrosis was shown in the liver, spleen and lymph nodes. Serological findings and isolation of Chlamydia from fecal specimens indicated a wide dissemination of C. psittaci among cows in the area.     

Inhibitory effects of epigallocatechin gallate on the propagation of bovine coronavirus in Madin-Darby bovine kidney cells

Epigallocatechin gallate (EGCg) is the main active component of tea polyphenol and shows several biological activities, such as antimicrobial, antitumor‐promoting, anti‐inflammatory and anti‐oxidative activities. In the present study, the inhibitory effect of EGCg on bovine coronavirus (BCV) propagation in Madin‐Darby bovine kidney (MDBK) cells was investigated. EGCg at concentrations of less than 10 µg/mL did not show any cytotoxicity to MDBK cells. BCV propagation was significantly inhibited by pretreatment of the virus with EGCg (0.5–10 µg/mL) before virus inoculation in dose‐dependent, incubation time‐dependent and temperature‐dependent manners. The antiviral effect of pretreating MDBK cells with EGCg on BCV propagation was much weaker than that of pretreating BCV with EGCg. The hemagglutination activity of BCV was also reduced by EGCg in a dose‐dependent manner. These results demonstrate that EGCg possesses a distinct anti‐BCV activity and strongly suggest that EGCg interferes with the adsorption of BCV to MDBK cells by the interaction of EGCg with BCV particles. EGCg may therefore be a useful candidate for controlling BCV infection more effectively.     

Evaluation of meat meal, chicken meal, and corn gluten meal as dietary sources of protein in dry cat food

The nutritional value of meat meal (MM), chicken meal (CM), and corn gluten meal (CGM) as dietary sources of protein in dry food formulated for adult cats was evaluated. Twelve healthy adult cats (11 males and 1 female) were used. Dry diets containing MM, CM, or CGM as the main protein source were given for a 3-week period in a 3 x 3 Latin-square design. Digestion and balance experiments were conducted during the last 7 d of each period. In addition, freshly voided urine was taken to determine urinary pH and number of struvite crystals. As compared with the CM diet, dry-matter digestibility was higher and lower for the MM and CGM groups, respectively. Percentages of nitrogen (N) absorption and N retention to N intake were higher in the MM group, and N utilization was not different between the CM group and the CGM group. All cats excreted alkaline urine (pH > 7). Urinary pH, struvite activity product, and number of struvite crystals in urine were lower for the CGM group. There was no difference in retention of calcium and magnesium among the groups. From the point of view of digestibility and N utilization, MM is superior to CGM, and CM is better than or equivalent to CGM as a protein source of dry foods for adult cats. However, when CM is used as a dietary protein source, some manipulation of dietary base excess may be needed to control urinary acid-base balance, because CM contains higher calcium and phosphorus.     

Nitric oxide-overproducing transformants of Pseudomonas fluorescens with enhanced biocontrol of tomato bacterial wilt

The relation between nitric oxide (NO) production and the protective ability of Pseudomonas fluorescens T5 against bacterial wilt disease in tomato was examined. The endogenous nitric oxide reductase gene of T5 was disrupted by homologous recombination using a suicide plasmid. Three disruptants were obtained, and all had higher levels of NO production. Infection with Ralstonia solanacearum was reduced in tomato plants treated with the NO-overproducing transformants compared with the wild type. These results suggest that the modification of pseudomonads to increase their level of NO production is a new approach to enhancing their biocontrol efficacy.