Peripheral mononuclear cell response in Japanese black calves after oral administration of IFN-alpha

To investigate the effects of oral administration of an interferon (IFN)-alpha drug on the immune reaction of healthy Japanese Black (JB) calves, peripheral leukocyte populations and their ability to produce cytokine mRNA were analyzed after oral administration of IFN-alpha. Fourteen calves fed in one herd were divided into two groups; seven calves were orally administered 0.1 g/day of IFN-alpha from the day of birth to day 5 on each day (group 1, N=7), and the other seven calves were used as the control (group 2, N=7). Blood samples were collected from the jugular veins of all calves before administration and in weeks 1, 2, 4, 8, and 16 after birth. The number of MHC class II+CD14+ monocytes in the leukocytes population of group 1 increased gradually after birth, and significantly higher numbers were detected in week 4 compared with group 2. MHC class II-CD14+ monocytes in group 1 peaked in week 1, and a significant increase was detected compared with group 2. The level of IL-12 in the cytokine mRNA of group 1 increased gradually between weeks 1 and 2, and a significantly higher level of IL-12 was found compared with group 2. These results suggest that oral administration of IFN-alpha induces activation of the monocyte functions in JB calves.     

A potential use of color ultrasound as a tool for reproductive management: New observations using color ultrasound scanning that were not possible with imaging only in black and white

Ultrasonography (US) has been applied to the ovary and the uterus of domestic animals from the late 1980s, and established in 1990s as a practical tool for animal production. US made it possible to detect pregnancy at a very early stage and, most importantly, to observe the real-time dynamics of follicular development and hence the discovery of follicular waves. This has greatly contributed to our understanding of ovarian physiology and helped us to develop several "pin-point" protocols for hormonal treatment. While US may not seem to fit preconceived ideas of a "green" technology, it does not contravene environmental priorities, and it is non-invasive ("ethical") and non-hormonal ("clean"). Using the US technology that is now commercially available at a reasonable price, we are able to estimate the best timing for AI and this allows us to plan either the use of precisely-timed nutritional supplements for fetal development or an immediate 2nd AI service to achieve a better economic efficiency. During the last few years, we have also begun to be able to observe in detail the local blood flow in individual ovarian follicles and CL using color Doppler ultrasonography in the cow. From the series of observations, we have found that: 1) the change of blood supply to an individual follicle closely relates to the dynamics of follicular growth and atresia; 2) the local blood flow detected in the theca externa of mature follicles rapidly increases around the onset of LH surge and is most active before ovulation; 3) the blood supply to the developing CL increases in parallel with CL volume and plasma progesterone concentrations; and 4) the local blood flow surrounding the mature CL acutely increases prior to the onset of luteolysis in response to uterine as well as exogenous PGF(2alpha). It is now clear that color Doppler ultrasound is very useful for observing echogenicity with local blood flow thereby providing an easily obtained estimation of the physiological status of follicles, CLs and early conceptus. Widespread commercial application of color US will depend on further technological developments that reduce the cost and improve performance and ease-of-use. Overall, US is now a most effective non-invasive tool for managing reproduction, at the level of both the individual animal and the herd system. In particular, US can help us to clarify potential problems in high-producing dairy cattle during the postpartum period.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Survival of Corynebacterium renale, Corynebacterium pilosum and Corynebacterium cystitidis in soil

Survival of the causative agents of bovine pyelonephritis, Corynebacterium renale, C. pilosum and C. cystitidis, was examined at 30 degrees C in autoclaved soil. In the soil from a paddock, C. renale and C. cystitidis survived for 56 and 63 days, respectively, and C. pilosum for a longer period of at least 210 days. In soil from a pasture, sand from an athletic field and sea sand, the survival of these bacteria was of shorter duration.     

Histochemical localization of inhibin and activin alpha, beta A and beta B subunits in rat gonads.

The localization of alpha, beta A and beta B subunits of inhibin/activin polypeptides was studied in the ovary and testis of sexually mature, immature, and embryonic rats. Specific staining with these three subunits was also evident in the oocytes from embryonic to mature female rats. This result suggests that inhibin- and activin-like substances may be produced in the oocytes and these substances may play a role in the oocyte growth and differentiation. Judging from the intensity of immunoreaction in mature female rats, the three subunits should be produced more abundantly in luteal cells than in the granulosa cells. Immunoreactive alpha, beta A and beta B subunits were observed in the cummulus oophorous in the morning (11:00), but not in the evening (23:00) on proestrus. The results are in well agreement with the previous report that inhibin alpha and beta A subunit mRNA signals decline on proestrus evening. It is supposed that the cyclic change may be related with physiological phenomena prior to the ovulation, such as primary gonadotropin surges, loss of cummulus-oocyte gap junctions, or germinal vesicle breakdown. In both germ cells and Sertoli cells of the testis, alpha, beta A and beta B subunits were more abundant in the embryonic rat than in the mature rat. Although clear reactions with beta A and beta B subunits were detected in Leydig cells, alpha subunit was not detectable in the cells throughout the developmental stages examined.     

Formation of male and female sex cords in gonadal development of C57BL/6 mouse

The sex cords of male and female fetal C57BL/6 mice were studied by light and transmission electron microscopy to elucidate the origins of Sertoli cells (male) and follicle cells (female) in detail. In the testes of fetal mice from day 12 to day 14 post coitum (p.c.), PAS-positive substances were detected exclusively throughout the cytoplasm of Sertoli cells. On day 12 p.c., pre-Sertoli cells, identified by PAS-reaction, formed irregular and cord-like arrangements around germ cells. The arrangements were not associated with the coelomic epithelium. Thus, it is suggested that Sertoli cells are originated from the mesonephric tissues. In the ovaries, germ cell cords were still not observed at a stage immediately following the gonadal sex differentiation in male. On about day 15 p.c., connective tissues including many capillaries penetrated into the ovaries, resulting in obvious formation of germ cell cord-like arrangements. At the same time, the coelomic epithelium-derived cells (CEd cells) as well as the mesonephros-derived cells (Md cells) invaded the adjacent arrangements. It is concluded that the follicle cells are originated most from Md cells and some from CEd cells.     

Serological relationship of a Japanese Babesia species and Babesia bigemina by the complement fixation and capillary-tube agglutination tests

The complement fixation (CF) test and the capillary-tube agglutination (CA) test were used to study the antigenic relationship between Babesia bigemina and the large Babesia species frequently infecting cattle in Japan. The CF antigen was prepared from parasitized erythrocytes by extraction with distilled water. The CA antigen was prepared from parasitized erythrocytes by mild sonification of mixtures of Babesia and erythrocyte stroma, following lysis of the erythrocytes with hypotonic saline solution. All the sera used were collected from experimentally-infected cattle. Cross reaction was demonstrated between the Japanese Babesia species and B. bigemina. There was, however, a difference of two dilutions in titer between homologous and heterologous antibody in the CF test, and a difference of more than three tubes in titer between both antibodies in the CA test. It was possible, therefore, to distinguish the Japanese Babesia species from B. bigemina by the CF and CA tests.     

Physiological levels of C-reactive protein in normal canine sera

This study was undertaken to investigate whether the level of C-reactive protein (CRP) in the serum of dogs undergoes physiological variation, using 10 normal Beagle dogs (5 males and 5 females), 1–2 years old, maintained in a healthy condition in a controlled environment. The CRP concentration in the sera collected seven times each day at intervals of approximately 3 h ranged from 0.8 to 16.4 µg/ml (mean 5.06±3.60) in one experiment and from 0.8 to 14.0 µg/ml (mean 4.50±2.80) in a second experiment. On examining the 24-h variations in the concentration of CRP in serum, neither consistent changes nor a definite pattern of circadian rhythm was detected. During 28 days observation, only very slight changes, which seemed attributable to analytical errors, were seen in any of the dogs, except one. The concentration of CRP in the serum during the 28 days ranged from 0.8 to 22.6 µg/ml (mean 3.65±1.40). The concentrations underwent no significant variations in individual dogs, but significant differences were found between the dogs (p<0.01).     

MRI examination of trachea and bronchi in the Ganges River dolphin (Platanista gangetica)

The MRI examination was carried out in a formalin-fixed specimen of the Ganges River dolphin (Platanista gangetica), one of the evolutionary primitive species of cetaceans. We could morphologically elucidate the tracheobronchial ramification in the intact whole body. We demonstrated from the MRI sections that the characteristic tracheal bronchus branches from the trachea at the cranial portion. These findings suggest the phylogenetic relationships between cetaceans and artiodactyls. The left bronchus is obviously larger in diameter than the right one. We suggest that the right bronchus has smaller capacity of gas exchange than the left one, because the dolphin possesses the tracheal bronchus in the right lung. The MRI method will be important in the non-invasive study of the anatomy in endangered animal carcass as Ganges River dolphin.