The current review aims to establish insulin-like growth factor-1 (IGF-I) as the factor that signals nutritional status to the reproductive axis, and show that assessment of IGF-I in blood early postpartum during the negative energy balance (NEB) period could be used to predict both nutritional and reproductive status in dairy cattle. The review also explores the effect of nutritional status on circulating IGF-I concentrations and the endocrine role of IGF-I on the reproductive axis. IGF-I plays an important role in gonadotropin-induced folliculogenesis, ovarian steroidogenesis and corpus luteum (CL) function. It also modulates pituitary and hypothalamus function. IGF-I clearly has an endocrine role on the reproductive axis. Severe under nutrition significantly reduces plasma IGF-I concentrations. During the critical period of NEB in high yielding dairy cattle early postpartum, IGF-I concentrations are low in blood and its levels are positively correlated to energy status and reproductive function during this period. Changes in circulating IGF-I immediately postpartum may help predict both nutritional and reproductive status in dairy cattle. IGF-I is therefore one of the long sought factors that signal nutritional status to the reproductive axis.
The development of the cecum and colon in the goose was investigated during the period from the 15th to 28th day of the incubation and from 1 to 30 days of age after hatching by light microscopy. By day 15 of the incubation, in the cecum and colon, the lumen was surrounded by pseudostratified epithelium. The previllous ridges appeared at 15th and 17th days of the incubation in the colon and ceca, respectively. At the base of previllous ridges, the epithelium changed into a simple prismathic epithelium at 15th and 17th days of the incubation in the colon and cecum, respectively. The villi appeared at the 21st days of the incubation. The crypts and goblet cells appeared on the first day after hatching. In the pre-hatching period, the lamina muscularis mucosa was present only in the colon. The submucosa consisted of loosely aggregated connective tissue in the pre-hatching period. In the post-hatching period, it consisted of a very thin layer of connective tissue. Its presence was only obvious where the cells of the submucosal nerve plexus or occasional large blood vessels considerably increased its thickness. The nerve plexus corresponding to the Auerbach's plexus of the mammalian intestine and submucosal nerve plexus appeared by 15th days of the incubation. From the 15th to 28th day of incubation, the tunica muscularis consisted of circular smooth muscle cells in the ceca. On the 28th day of the incubation a thinner longitudinal muscle layer added to the circular muscle layer. In the colon there was an outher longitudinal and a thicker circuler muscle layer.
The prevalence of virulent R. equi having 15- to 17-kDa antigens (VapA) in fecal isolates from 13 thoroughbred foals and their dams on 5 farms in Kagoshima, Japan, and the plasmid profiles of VapA-positive isolates by restriction fragment digestion patterns were investigated to compare the genotypic variation among virulence plasmids of R. equi isolates from Japan. In total, 218 (24.6%) of 886 isolates from the feces of the 13 foals and 13 (12.5%) of 104 isolates from the feces of their dams demonstrated VapA-positive R. equi. Plasmid DNA preparations of 231 virulent isolates from foals and dams were analyzed by restriction enzyme digestion with endonucleases EcoRI, EcoT22I and HindIII and were divided into 3 types: 172 isolates contained a 90-kb type I plasmid, 57 contained a 90-kb type III plasmid and 2 contained a 90-kb type IV plasmid. This study demonstrates a geographic character in the distribution of virulence plasmids found in VapA-positive isolates from thoroughbred foals in Kagoshima.
The effects of triiodothyronine (T3) on differentiation-dependent expression of GLUT and responses of glucose transport to insulin and norepinephrine (NE) were investigated. Precursor cells of brown adipocytes isolated from the interscapular brown adipose tissue of newborn rats were cultured in the absence or presence of various concentrations of T3. Western bolt analysis revealed that treatment with T3 resulted in an increased expression of GLUT4, in a dose-dependent manner, whereas GLUT1 contents were unchanged. In parallel with the increase in GLUT4 expression, T3 improved insulin sensitivity for glucose transport, being accompanied by an increase in maximal transport rate and a reduction of ED50. In contrast, T3-treatment of the brown adipocytes during the differentiation process had little effect on NE-regulatable glucose transport system. These results suggest that T3 plays a predominant role in the development of insulin-sensitive glucose transport during differentiation of brown adipocytes.
Serum cytokine levels and their expression of mRNA on neutrophils from a bone marrow (BM) transplanted heifer with leukocyte adhesion deficiency were evaluated. The clinical condition of the affected heifer was relatively stable after BM-transplantation. Persistent hyper γ-globulinemia and increased serum immunoglobulin G (IgG) concentrations were monitored longitudinally. The concentration of interleukin (IL)-1β in serum from the affected heifer ranged from 15.8 to 321.7 ng/ml, and maximum concentration occurred at the time which coincided with peak IL-6. Serum levels of IL-6 ranged from 0.32 to 27.9 ng/m l, and they appeared to be associated with the increment of serum IgG in the affected heifer. mRNAs for IL-1β, IL-6, IL-8 and granulocyte and macrophage colony stimulating factor (GM-CSF) were increased in neutrophils from the affected heifer compared to controls. Persistent hyper γ-globulinemia of the affected heifer appeared to be associated with enhanced mRNA expression for IL-6 and its serum levels. These findings suggest that humoral immunity of the affected heifer is activated and the production of neutrophils appears to be enhanced under the incapability of β2 integrin-mediated functions of phagocytic cells.
To evaluate the effects of epidermal growth factor (EGF) on placental amino acids uptake, transport activities for L-proline, L-leucine, and L-alanine were kinetically examined in placental microvillous vesicles(PMV) obtained from pregnant rats administered with EGF(100 and 200 μg/kg/day) from day 18 to 21 of pregnancy. The Vmax of Na+-dependent proline uptake remarkably increased with a dose-dependent manner of EGF, while Km did not change. In contrast, Vmax and Km values of Na+-dependent and -independent alanine, and Na+-independent leucine uptake were not affected. These results suggested that EGF enhanced proline transport activity in placental microvillous membranes, resulting in an increase of proline concentration in the fetal blood. The selective up-regulation of proline uptake was considered to contribute to fetal growth by EGF.
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.
To investigate the early host defense function in aquatic animals, the respiratory burst activity of bottlenose dolphin neutrophils against soluble and particulate stimulants was measured by luminol-dependent chemiluminescence assays and compared with those of bovine and human. Dolphin neutrophils generated the respiratory burst in response to phorbol 12-myristate 13-acetate (PMA), concanavalinA (ConA), heated-plasma (HP), and homologous-plasma opsonized zymosan except N-formyl-Met-Leu-Phe (fMLP). However, the respiratory burst of dolphin neutrophils stimulated by lipopolysaccharide and Staphylococcus aureus was inferior to those of bovine and human. Furthermore, DP-OZ also induced the respiratory burst of bovine and human neutrophils. In conclusion, dolphin neutrophils responded to several soluble and particulate stimulants as well as human neutrophils, but were refractory or slightly responded to bacterial agents.
In an attempt to study the immunological effects on normal and adenocarcinoma (AC) dogs, the natural killer (NK) activity was determined. Augmentation of NK cell activities in responsive normal and AC dogs that indicatedanergy in the phaseolus vulgaris agglutinin (PHA) skin-test was manifested when the animals were accordingly treated with germanium (GN).
Housedust mites, Dermatophagoides pteronyssinus (D. pteronyssinus) and Dermatophagoides farinae (D. farinae), are the important causative agents of allergic diseases in human and animals. By using 165 dogs suffering from atopic dermatitis (AD), serum levels of immunogloblin E (IgE) antibody against 25 kinds of allergen including housedust mites were determined. Housedust mites were the most frequent allergen against which 90 of the 165 allergic dogs (54.5%) by IMMUNODOT assay. With the further analysis of immunoblotting assay in the 90 dogs sensitized with housedust mites, antigenic proteins of housedust mites recognized by IgE antibodies were with the apparent molecular masses of 15, 76, 90, 98, and 170-kD. Among them, the 15-kD protein that might be identical to Group 2 antigens (Der f2, Der p2) was prominently observed (52/90). This study indicates that about a half of dogs with AD were sensitized to housedust mites, suggesting that Group 2 antigens of housedust mites may be a major allergen in canine AD.
After intravenous (IV) infusion of various volumes of 1.35%-isotonic sodium bicarbonate solution (ISB), acid-base equilibrium, blood pressure, plasma volume and biochemical parameters in healthy Holstein calves were studied. Four calves each were randomly assigned to the low-dose (LD; IV infusion of 5 ml/kg ISB), middle-dose (MD; IV infusion of 10 ml/kg ISB) and the high-dose groups (HD; IV infusion of 15 ml/kg ISB). Administration volumes of ISB in the LD, MD and HD groups were decided based on the first half volumes of 5, 10 and 15 mEq of base requirement by the acceptable equation. Systemic, pulmonary artery and central venous pressures, cardiac output and plasma osmotic pressure were not changed by ISB infusion and remained constant throughout the experiment for all groups. There was good correlation (r2 = 0.950) between relative changes in base excess and infused volume of bicarbonate (y=2.491x). The coefficient of distribution for bicarbonate ions was calculated to be 0.401 (=1/2.491). Therefore, it is suggested that a value of 0.4 would be most appropriate when calculating the base requirements in calves. Therefore, the first half volumes of ISB correcting base deficits of 5, 10 and 15 mEq in calves were estimated to be 6, 12 and 18 ml/kg, respectively. On the basis of the findings in this study, ISB may be used to correct metabolic acidosis without altering the plasma osmotic pressure, hemodynamic status and respiratory function in the calves.
The effects of chlorpromazine (CPZ), pentoxifylline (PTX) and dexamethasone (DEX) on mRNA expression of lipopolysaccharide (LPS)-induced proinflammatory cytokines were examined in bovine peripheral blood mononuclear cells (PBMCs) in vitro. The expression of inflammatory cytokine mRNAs was analyzed by RT-PCR and Southern blot hybridization in bovine PBMCs. CPZ and DEX decreased the expression of cytokine mRNA (such as interleukin-1β and tumor necrosis factor-α) after stimulation with LPS in a dose-dependent manner. However, pretreatment with PTX had no inhibitory effect on the mRNA expression of proinflammatory cytokines. These results indicated that pretreatment with CPZ and DEX might be effective to reduce the production of LPS-induced inflammatory cytokines in bovine PBMCs in vitro.
Microspheres composed of biocompatible, biodegradable poly dl-lactide-co-glycolide (DL-PLGA) and Povidone-iodine were evaluated as an intramammary disinfectant delivery system in vitro prior to infusion into mammary glands. Microsphere was prepared by solvent evaporation method and particle size, morphology and in vitro release kinetics were examined. The microspheres were ranged in size from 25 μm to 155 μm (mean diameter = 65.7 μm). Povidone-iodine was dispersed on the surface of microsphere and microsphere was spherical in shape with a smooth surface. The yield of microsphere was 57.3% and the encapsulation efficiency was 69.6%. In in vitro release study, a burst effect (50.9%) was observed during the first two days and a sustained release then continued for the next 28 days. Results of the present study demonstrated that microsphere have the potential for new intramammary disinfectant formulations that can provide increased efficacy of therapy against mastitis pathogens.
A 9-month-old intact male American cocker spaniel was referred because of hepatomegaly and ascites. Ultrasonographic evaluation of the liver revealed congestion and increased parenchymal echogenicity with focal and more hyperechoic nodules. Histopathology of the hepatic lesion revealed diffuse, ill-defined vascular proliferation. A single layer of endothelial cells, which showed signs of minimal cellular atypia, lined the irregular vessels. On immunohistochemistry, the proliferative endothelial cells lining the irregular vessels were positive for an antiserum to factor VIII related antigen. Based on these findings, the dog was diagnosed with hepatic lymphangiomatosis.
Babesia equi (EMA-1) and Babesia caballi (BC48) gene fragments were amplified by polymerase chain reaction (PCR), in blood samples, and partially fed-females and egg and larval progenies of Dermacentor nuttalli, collected from horses in Altanbulag, Tuv Province, Mongolia. While Babesia parasite DNA was detected in some horse blood samples during the first PCR, all positive cases in partially fed-female ticks, eggs and larvae were confirmed by nested PCR. Present study reinforces earlier similar findings in unfed D. nuttalli ticks collected from an open space vegetation in Bayanonjuul, Tuv Province in Central Mongolia, pointing to the most likely important role of D. nuttalli in the transmission of equine babesiosis in Mongolia. The detection of parasite DNA in eggs and larval progenies is likewise suggestive of transovarial parasite transmission in this tick species.
In 1996 and 1997, the seroprevalence against Leptospira in parturient sows with premature birth or stillbirth from two herds was investigated. In three out of four sow serum samples obtained in Gunma Prefecture, the antibody titers to Leptospira interrogans serovar copenhageni (M20) were higher than 10,000 (the reciprocal of the serum dilution). Furthermore, the antibody titers to L. interrogans serovar canicola (Hond Utrecht IV) were significantly high in the three sows and the titers ranged from 1,000 to 3,000. In sows obtained in Chiba Prefecture, significantly high antibody titers to serovar copenhageni (M20) were confirmed in eight out of 40 sows, and antibody titers greater than 10,000 in six of them. Significantly high antibody titers to L. interrogans serovar icterohaemorrhagiae (RGA) and L. canicola (Hond Utrecht IV) were confirmed in four and 18 out of the 40 sows, respectively, compared with the titers to the other serovars. These findings may indicate the prevalence of leptospirosis in pig herds in both Gunma and Chiba Prefectures.
This study was performed to validate the procedure of transarterial embolization of the renal artery (TAE-RA) using iohexol-ethanol solution in rabbits with unilateral experimental hydronephrosis and to evaluate the embolized kidney and contralateral normal kidney using B-mode ultrasonography and color Doppler ultrasonography. Experimental hydronephrosis was induced at 17 days after ligation of unilateral ureter in 13 rabbits. Renal artery embolization was performed using selective catheterization in the hydronephrotic kidney of eight rabbits and electrocardiography, oxygen saturation, body temperature, pulse, and respiratory rate were within normal ranges during procedures. Iohexol-ethanol solution was used as embolic material. Average ethanol dose for renal artery embolization was 1.4 ± 0.7 ml/kg. There were no rabbits expired after TAE-RA and no side effects associated with regurgitation of iohexol-ethanol solution. In color Doppler ultrasonographic findings, there was no blood flow into the embolized kidneys treated by TAE-RA, however, blood flow signal was found in hydronephrotic kidney not treated by TAE-RA. Ultrasonographically, the mean longitudinal length of the embolized kidney significantly decreased at 2 and 3 months after TAE-RA. No significant difference of resistive index values was found between contralateral normal kidney of rabbits treated by TAE-RA and contralateral normal kidneys of rabbits treated with nephrectomy. We may conclude that TAE-RA with iohexol-ethanol solution is a viable alternative to nephrectomy in rabbits with unilateral hydronephrosis.
The objective of this study was to evaluate whether changes in NaCl concentration in a fertilization medium could improve normal fertilization and preimplantation development of bovine oocytes. In vitro matured bovine oocytes were inseminated with frozen-thawed semen for 18 hr in a Tyrode's medium with albumin, lactate and pyruvate (TALP), to which 114 (TALP-114), 96 (TALP-96) or 78 (TALP-78) mM NaCl was added. Presumptive zygotes were cultured for 192 hr in a modified TALP containing 90 mM NaCl, 1.5 mM glucose, 0.3% (w/v) BSA, minimal essential medium (MEM) essential and nonessential amino acids, and insulin-transferrin-selenium complex. Lower polyspermy rate was obtained by the insemination in TALP-96 (7.8 ± 2.3%) than by the insemination in TALP-114 (25.6 ± 1.4%), without decrease in male pronucleus (MPN) formation. Fertilization in TALP-78 also yielded decreased polyspermic fertilization (3.8 ± 1.5%), but significant decrease in MPN formation was found (63.1 ± 3.1%). In preimplantation development, more blastocysts developed from oocytes inseminated in TALP-96 (24.1 ± 1.7%) than from oocytes inseminated in TALP-114 (16.8 ± 1.4%). TALP-78, however, did not improve preimplantation development beyond the 8-cell stage compared with TALP-114. Mean cell number of blastocyst was higher when oocytes were fertilized in TALP-96 (137.0 ± 4.5) than in TALP-114 (123.1 ± 5.1) and in TALP-78 (102.3 ± 4.5). These results demonstrate that insemination of bovine oocytes in a TALP with decreased NaCl concentration (96 mM) improves blastocyst formation and embryo viability. Decrease in NaCl concentration below 96 mM, however, may delay or inhibit MPN formation, and inhibits subsequent development in vitro.
Plasma steroid profiles following follicle-stimulating hormone (FSH) or equine chorionic gonadotropin (eCG) injection were studied in chronically gonadotropin releasing hormone agonist (GnRH-A)-treated cows. Follicular development and irINH secretion were stimulated by FSH or eCG injection. The plasma concentrations of estradiol-17 β (E2) and testosterone (T) were markedly increased following eCG injection. However, significant increases of the plasma E2 and T concentrations were not detected in FSH-treated cows. Ovulation of developed follicles were depended on the hCG injection in both groups. These results show: 1) Follicular response to an exogenous gonadotropin is still remained, 2) Ovulation of developed follicles is induced by hCG injection and 3) FSH and eCG cause disparate plasma steroid profiles, under the influence of repeated GnRH-A treatment.