Guanylyl cyclase C and guanylin reduce fat droplet accumulation in cattle mesenteric adipose tissue.

Guanylyl cyclase C (GC-C) is a member of a family of enzymes that metabolize GTP to cGMP and was first identified as a receptor for heat-stable enterotoxin. Guanylin (GNY) has since been identified as an endogenous ligand for GC-C in the intestine of several mammalian species. The GNY/GC-C system regulates ion transportation and pH in the mucosa. Recently, it was reported that GC-C and GNY are involved in lipid metabolism in rat mesenteric adipose tissue macrophages. To examine the role of GC-C and GNY in lipid metabolism in cattle, we used a bovine mesenteric adipocyte primary culture system and a coculture system for bovine adipocytes and GNY-/GC-C-expressing macrophages. Fat droplets were observed to accumulate in bovine mesenteric adipocytes cultured alone, whereas few fat droplets accumulated in adipocytes indirectly cocultured with macrophages. We also observed that GC-C was present in bovine mesenteric adipose tissue, and that fat droplet accumulation decreased after in vitro GNY administration. Expressions of mRNAs encoding lipogenic factors decreased significantly in adipocytes after either coculture or GNY administration. These results suggest that the GNY/GC-C system is part of the control system for lipid accumulation in bovine mesenteric adipose tissue.

Detection and quantification of bovine signal joint T-cell receptor excision circles.

A signal joint (sj) T-cell receptor excision circle (TREC) is produced by T-cell receptor (TCR) gene rearrangements during αß T-cell maturation in the thymus. sjTREC have been studied as a marker of thymic function in several spices. We designed specific primers for δrec-ψJα sj region to identify the location of the bovine sjTREC region and determined the nucleotide sequence of the PCR product. The obtained sequences were subjected to a BLAST search, which identified a matching region. This matching region contained TCR δ genes and was identified on bovine chromosome 10. We also confirmed the polymorphism of the sj region by sequencing of 10 PCR products, and observed irregular insertion of bases in the δrec-ψJα recombination signal sequence. We then developed a quantitative PCR (QPCR) assay for evaluation of sjTRECs level in order to evaluate bovine thymic function for application in the veterinary clinic. This QPCR assay specifically amplified the sj region of bovine sjTREC and could detected 10(1)-10(7) copy numbers of sjTRECs. Using this assay we found that the number of sjTRECs in peripheral blood mononuclear cells was less than 10% that of the thymus.

An epidemiological study of Hypoderma infection and control using ivermectin in yaks in Qinghai Province, China.

The prevalence of Hypoderma spp. in yaks grazed in the east of Qinghai province was investigated in 2008. In this area, the prevalence in young yaks (1- to 3-year-old) was very high at 82.2-98.7%, whilst in adult yaks (4-year-old and older), the prevalence was 42.4-50.6%. The seasonal development and migration pattern of Hypoderma larvae in yak bodies was found to be similar for different locations in this area. The numbers of first, second and third instar larvae detected in yak bodies peaked in October, December and March, respectively. Different doses of ivermectin (125 to 500 µg/kg body weight) almost completely dewormed the larvae from yaks, suggesting that using a quarter of the prescribed dose (500 µg/kg body weight) was effective. In October of each year between 2009 and 2012, ivermectin (125 µg/kg body weight) was administered to a total of 562,995 yaks grazed in four counties in Qinghai province, and the pevalence of Hypoderma larval infection in yaks was reduced to 0.5-1.0%.

Epidemiological study and control trial of taeniid cestode infection in farm dogs in Qinghai Province, China.

An epidemiological study and control trial were conducted to assess taeniid infection in farm dogs in Qinghai Province, China. To improve egg detection by fecal examination, a deworming step with praziquantel was incorporated into the sampling methodology. As a result, a marked increase in the number of egg-positive samples was observed in samples collected at 24 hr after deworming. Then, the fecal examination and barcoding of egg DNA were performed to assess the prevalence of taeniid species in dogs from Xinghai, Haiyan, Gangcha and Chengduo counties. Analysis of 277 dog feces revealed that taeniid cestodes, including Taenia spp. and Echinococcus granulosus, were highly prevalent in Xinghai (34.4%), but eggs were not found in Haiyan where a control trial on canine echinococcosis had been conducted 20 years previously. A control trial involving the administration of 5-10 mg/kg praziquantel to 90 farm dogs at 45-day intervals was conducted in Xinghai. The prevalence of taeniid cestodes in the dogs was reduced to 9.6% and 4.9% after one and two years, respectively, indicating that some dogs were not administered praziquantel properly. A questionnaire survey of farmers in Xinghai and Haiyan revealed that most farmers in Xinghai were not familiar with echinococcosis or the transmission route of the disease, while most farmers in Haiyan had a more thorough understanding of the disease. The findings implied that a program for educating local farmers would be important for efficiently controlling canine taeniid infection in the region.

A mechanism for selective lymphocyte homing in bovine hemal nodes.

The distribution and abundance of MECA-79(+) cells in bovine hemal nodes (HNs) was analyzed. In addition, T cell subsets which expressed the homing receptor l-selectin were analyzed by flow cytometry. The frequency of MECA-79(+) HNs varied depending on the location. There were 61, 33, and 17% MECA-79(+) HN in the subcutaneous region, along the abdominal aorta and in the mesenteric region, respectively. MECA-79(+) cells in mesenteric lymph nodes were mainly distributed in the paracortex. Many MECA-79(+) cells were distributed in the perifollicular area of HNs and a few positive cells were also located in the paracortical and interfollicular areas. CD4(+) and CD8(+)l-selectin(+) cells were significantly higher in MECA-79(+) HNs compared to MECA-79(-) HNs. The data suggest that a selective lymphocyte homing mechanism exists in bovine HNs, which could be related to functional differences between locations.

Survey on helminths in the small intestine of wild foxes in Qinghai, China.

The intestinal helminth fauna of Tibetan sand foxes (Vulpes ferrilata) and red foxes (Vulpes vulpes) inhabiting in Qinghai, China, was evaluated by conducting necropsy of hunted foxes and fecal egg examination of field-collected feces. In northeast and south Qinghai, 36 foxes were necropsied, and the species of foxes and the parasites detected were identified by the DNA barcoding. In 27 red foxes and 9 Tibetan sand foxes examined, Mesocestoides litteratus (total prevalence: 64%), Toxascaris leonina (50%), Taenia pisiformis (8%) and Taenia crassiceps (8%) were found in both species of foxes. Echinococcus shiquicus (8%) and Taenia multiceps (6%) were found only in Tibetan sand foxes. Echinococcus multilocularis (3%) and Alaria alata (8%) were found only in red foxes. In the fecal egg examination of the rectal feces, 100% of taeniid cestodes, 73% of Toxascaris and 27% of Mesocestoides worm-positive samples showed egg-positive, indicating that coprological survey for parasite eggs could only provide partial information of intestinal parasite fauna. For field-collected feces, molecular identification of feces origins and fecal egg examination were performed. In 15 Tibetan sand fox and 30 red fox feces, we found E. multilocularis eggs in one feces of Tibetan sand fox. The present study indicated that the upper intestinal helminth fauna of the two fox species in Qinghai does not differ significantly and both species would play an important role in the maintenance of taeniid cestodes.

Scanning electron microscopic study of the vascular system in the hemal node of the bovine cervical region.

The vasculature of the hemal node (HN) from the bovine cervical region was investigated using a combination of vascular corrosion casting and scanning electron microscopy. A dense vessel network of capsule was found surrounding the cast of HN parenchyma and had no connection with the subcapsular sinus; these vessels converged and exited the HN via the hilar vein. Within the HN, many anastomoses were found between the capillary networks and the surrounding sinuses in the follicular zone and deep cortex. The sinusoid pathway in the HN was characterized by subcapsular sinuses, which were continuous with the trabecular sinuses and tubular sinuses over the parenchyma, and these sinuses finally entered the medullary veins. In our study, direct communications between cortical capillaries and subcapsular sinuses were identified. This may explain the origin of numerous erythrocytes in the HN sinusoids and help to understand lymphocyte migration of the HN.

Anatomical and histological characterization of ileal and jejunal Peyer's patch in lesser mouse deer (Tragulus javanicus).

Tragulidae is a primitive ungulate family within the order Cetartiodactyla, suborder Ruminantia. Domestic ruminants such as cattle, sheep, and goat have two types of Peyer's patches (PP): jejunal and ileal PP, in which there are morphological and functional differences. In this study, lesser mouse deer (Tragulus javanicus) PP was studied by gross anatomical and histological procedures. At the fetal stage, both types of PP were formed in the small intestine. Ileal PP was observed as a single continuous aggregation of lymphatic follicles extending cranially from the ileo-caecal junction. However, jejunal PP was observed as multiple and discrete accumulations of lymphatic follicles. This study showed that the lesser mouse deer has two types of PP in the small intestine. In addition, the anatomical and histological characteristics of jejunal and ileal PP are quite similar to those of other ruminants' jejunal and ileal PP. Further studies are needed to analyze immune function of both PP in lesser mouse deer in order to determine the evolutionary process of Cetartiodactyla.

Comparative studies on the distribution and population of immunocompetent cells in bovine hemal node, lymph node and spleen.

The distribution and population of immunocompetent cells in bovine hemal node, mesenteric lymph node and spleen were analyzed comparatively by immunohistochemistry and flow cytometry. Many CD8(+) cells, CD172a(+) cells and γδ T cells were found in the lymphatic cord along the sinus of the hemal node and the splenic red pulp. A few CD8(+) cells and γδ T cells were distributed diffusely in the paracortex and medullary cord of the mesenteric lymph node. Many germinal centers were recognized in the lymphatic regions such as the cortex and white pulp of these lymphoid organs. The populations of CD8(+) cells and γδ T cells in the hemal node and the spleen were higher than those of the mesenteric lymph node. In addition, the populations of CD21(+) cells and MHC class II(+) cells in the hemal node and the mesenteric lymph node were higher than those of the spleen. The results suggest that the hemal node has an important role in both cellular and humoral immunity as well as the lymph node and the spleen in cattle.

Anatomical variations in bovine thoracic ducts.

Gross anatomical observations of bovine thoracic duct pathways and the lymph-venous junctions revealed that 37% of these ducts connected to the left venous angle at one location, whereas the other terminal connected to other areas, such as the left internal jugular vein, the left subclavian vein and the right venous angle, at more than one location. The thoracic duct pathways were classified according to Adachi's classification as types III, VI and IX. The frequencies of types VI, IX and III were 76%, 15%, and 9%, respectively and 48% of cattle had more than one ring formation in the thoracic duct pathway. These findings demonstrate many anatomical variations in bovine thoracic duct pathways and lymph-venous junctions.

Scanning electron microscopic study of vascular and biliary casts in chicken and duck liver.

Avian liver is structurally different from that of mammal. There are only a few reports about the ultrastructure of the hepatic vessels and bile duct in birds. Casts of the hepatic vessels and bile ducts in chicken and duck were examined by a scanning electron microscope (SEM) to provide further detail. The sinusoidal vessels formed regular three-dimensional networks but the replicated bile ducts formed irregular ones. There was a dense plexiform network around each tubular cavity in biliary casts. This biliary plexus formed around a small branch of the portal vein. It was the transition between the bile capillaries and ductules. The present study shows that the liver of chicken and duck had the characteristic structure at the peripheral part of biliary system, i.e., biliary plexus.

Comparative studies on the secondary lymphoid tissue areas in the chicken bursa of Fabricius and calf ileal Peyer's patch.

The chicken bursa of Fabricius and calf ileal Peyer's patch are thought to be the primary lymphoid organs of B cell development. In the bursa, the existence of secondary lymphoid tissue, called the diffusely infiltrated area, has been recognized. Recently, we have found the presence of a region of secondary lymphoid tissue in the ileal Peyer's patch at the period of the most rapid growth of this organ. In this study, we compared the development of these secondary lymphoid tissue regions in the bursa and ileal Peyer's patch histologically. Before hatching, lymphatic follicle formation occurred in the bursa, but not in the diffusely infiltrated area, where only a small number of lymphoid cells were found. However, during fetal calf development, lymphatic follicle formation occurred not only in the primary lymphoid organ but also in the secondary lymphoid tissue regions. Therefore, the prenatal development of the secondary lymphoid tissue regions of the bursa and ileal Peyer's patch were distinct. After hatching, formation of the germinal center, which contained many CD4+ cells, was observed in the diffusely infiltrated area of the bursa. After birth, many CD4+ cells and IgG mRNA expression were observed in the lymphatic follicle of the secondary lymphoid tissue regions in the ileal Peyer's patch, but rarely in the ileal Peyer's patch lymphatic follicles. The change of character of these secondary lymphoid tissue regions at the postnatal stage might be dependent on external antigens.

Differential cytokine mRNA expression in single lymphatic follicles of the calf ileal and jejunal Peyer's patches.

The ruminant gut-associated lymphoid tissues are broadly classified into ileal and jejunal Peyer's patches (PP). We isolated single lymphatic follicles from ileal and jejunal PP and examined mRNA expression of 13 cytokines using RT-PCR. Four patterns of differential expression were identified. In Pattern 1, the cytokines IL-7, IL-10, IL-12, and IL-18 were detected in all follicles of both ileal and jejunal PP. In Pattern 2, the cytokines IL-2, IL-4, and IL-13 were expressed in most jejunal PP follicles, but were undetectable in the ileal PP follicles. The cytokines characterizing Pattern 3 (IL-1beta, IFN-gamma, and IL-6) were detected in all follicles of the jejunal PP, but were differentially expressed in each follicle of ileal PP. In Pattern 4, the cytokines IL-8, TNF-alpha, and GM-CSF were variably expressed in follicles of both ileal and jejunal PP. More detailed knowledge about differential expression of cytokines in ileal and jejunal PP will facilitate a better understanding of the immune responses of primary and secondary lymphoid organs in the bovine small intestine.

Impact of transglutaminase on the textural, physicochemical, and structural properties of chicken skeletal, smooth, and cardiac muscles.

This study examined the effects of microbial transglutaminase (MTG; 3.1mg/ml) on chicken skeletal, smooth, and cardiac muscles; the meat containing the different muscle types was shaped into sausages and treated at 40°C and/or 78°C for 30min. Although the three muscle types were obtained from the same bird, the effects of MTG addition were not uniform. All the muscle types showed a significant increase in the breaking strength (P<0.01), but skeletal muscle exhibited the maximum increase. All samples showed a decrease in the fluorescence intensity and a significant reduction in the concentration of proteins that were extracted in a high ionic strength solution (P<0.05). Scanning electron microscopy images and histological studies revealed that different muscle types had different physical structures and frameworks after MTG treatment, which is a reflection of the differences in the reaction specificity of MTG with different muscle proteins. Histological studies revealed that the reactions of MTG with meat proteins are both exogenous and endogenous. Cooking loss data suggested that MTG did not have any negative effect on water retention during cooking. MTG appears to be a functional and contributive substance since the results suggest that MTG can function on all muscle types that are mechanically processed for different industrial applications. MTG aggregates muscle proteins in different ways that improve their organoleptic properties such as texture, appearance, and water retention.

Effect of microbial transglutaminase on the natural actomyosin cross-linking in chicken and beef.

The objective of this research was to investigate the difference between chicken and beef in the interaction of actomyosin (myosin B) with microbial transglutaminase (MTG). The gel strength of myosin B was improved in both species and was significantly greater in beef than in chicken (P<0.01). The degree of protein viscosity and the ε(γ-glutamyl)lysine (G-L) content were significantly higher in beef than in chicken (P<0.01). Myosin heavy chain (MHC) bands visualized by SDS-PAGE revealed that the same proteins in various meat species vary in their size and structure. Scanning electron microscope images (SEMI) revealed that myosin B in both species was polymerized, and formed multi-projection structures of G-L; surprisingly, more of these structures were found in beef than in chicken. It is possible that the proteins in chicken are folded into a strand shape that tightly encases a considerable number of glutamine and lysine residues, whereas MTG substrate cannot couple glutamine and lysine. This suggests that the reactivity of MTG is dependent on the residual amino acids present on the surface of myosin B in meat. Some protein components (peptides with long reiterated methylene groups attached) joined by disulfide bonds (cysteine) in chicken samples were inhibitory and reduced MTG activity. SEMI also suggested that all MTG-dependent mega-structures of protein molecules generated in chicken and beef may vary greatly in size, configuration and complexity after treatment with MTG. We concluded that the optimal cross-links in myosin B induced by MTG are heterogeneous in chicken and beef.

Secondary lymphoid areas in calf ileal Peyer's patch.

The secondary lymphoid tissues appear in sheep ileum after involution of ileal Peyer's patch (PP). However, the existence of the secondary lymphoid tissues before involution of ileal PP has not yet been studied. We examined morphological characteristics of the full length of calf ileal PP using gross and microscopic anatomical techniques. Most areas of ileal PP consisted of densely packed lymphatic follicles contained very few follicular T-cell and associated with only scant interfollicular areas. However, the proximal end of ileal PP consisted of widely dispersed lymphatic follicles contained many follicular T-cell and associated with large interfollicular areas. The histological architectures of the proximal end of ileal PP strongly resembled those of the secondary lymphoid tissue in calf.

Evaluation of olmesartan medoxomil in the rat monocrotaline model of pulmonary hypertension.

It is suggested that angiotensin II is involved in the pathogenesis of pulmonary hypertension and subsequent right ventricular hypertrophy; therefore, an angiotensin AT1 receptor antagonist could be beneficial for the treatment of this disease. We tested the effect of the new AT1 receptor antagonist olmesartan medoxomil on monocrotaline-induced pulmonary hypertension in rats. At 3 weeks after a single subcutaneous injection of monocrotaline (50 mg/kg), the lung/body weight ratio, the right ventricle/(left ventricle plus septum) weight ratio [RV/(LV+S)], and right ventricular systolic pressure were increased, indicating establishment of pulmonary hypertension and right ventricular hypertrophy. Oral administration of olmesartan medoxomil (2 or 5 mg/kg/day for 3 weeks) restored RV/(LV+S) and right ventricular systolic pressure, and a higher dose (5 mg/kg/day) improved the lung/body weight ratio. Pulmonary arteries isolated from monocrotaline-treated rats exhibited an increase in basal tone in the resting state, indicating that they had intrinsic tone. Three weeks of treatment with olmesartan decreased this intrinsic tone. These data suggest that long-term treatment with olmesartan has beneficial effects on monocrotaline-induced pulmonary hypertension and subsequent right ventricular hypertrophy.

Effect of glucagon-like peptide-1 and -2 on regulation of food intake, body temperature and locomotor activity in the Japanese quail.

To investigate the physiological roles of glucagon-like peptide-1 (GLP-1) and glucagon-like peptide-2 (GLP-2) in avian species, we elucidated the effect of intraperitoneal (i.p.) and intracerebroventricular (i.c.v.) administration of GLP-1 and GLP-2 on food intake, body temperature and gross locomotor activity in adult Japanese quail. Both i.p. and i.c.v. administration of GLP-1 suppressed food intake at 2, 4 and 12h after administration. Moreover, both i.p. and i.c.v. administration of GLP-1 significantly decreased both body temperature and gross locomotor activity 2h after administration. On the other hand, both i.p. and i.c.v. administration of GLP-2 had no effect on food intake, body temperature or gross locomotor activity. These results suggest that GLP-1 may have an important role in the regulation of food intake, body temperature and locomotor activity while GLP-2 may have no apparent effect on feeding regulation in adult Japanese quail.

Histological studies on the ontogeny of bovine palatine and pharyngeal tonsil: germinal center formation, IgG, and IgA mRNA expression.

The development and distribution of lymphocyte subsets in calf palatine and pharyngeal tonsil were examined. During prenatal development, B cells were distributed in the subepithelial area, and T cells and MHC class II(+) cells were found in the deep layer of B-cell area, respectively, in both tonsils. At neonatal stage, lymphoid follicle containing a few CD4(+) cells have been formed in both tonsils. IgG(+) and IgA(+) cells were found in the parafollicular and epithelial area. At 3 months old, many germinal centers were recognized in both tonsils. CD4(+) cells and IgG mRNA expression were detected in light zone of germinal centers. Many IgG, and IgA mRNA expressions also could be detected in the parafollicular and subepithelial area of both tonsils. The data suggest that both tonsils have an important role of local immune defense against invading antigen after birth. The comparison of the histological characteristics of tonsil and Peyer's patch during ontogeny is also discussed.

Scanning electron microscopic study on the microarchitecture of the vascular system in the pigeon lung.

The resin casts of the respiratory and vascular systems in pigeon lung were examined using a scanning electron microscope. The primary bronchi branched to form many secondary bronchi that anastomosed with each other via the parabronchi. Numerous infundibula protruded from the parabronchi via the atria and ramified into the air capillaries. The pulmonary artery entered into the lung and branched into three vessels that coursed the interparabronchial parts. The intraparabronchial arterioles penetrated the gas-exchange tissue to form the anastomosing networks of blood capillaries. The observation of the double casts of the respiratory and vascular systems revealed three-dimensional complicated networks of air capillaries and blood capillaries.