Control of adipogenesis in ruminants

Adipose tissue is an important organ that is involved in the peripheral regulation of body homeostasis, specifically, energy intake, storage and expenditure. Since fat metabolism is of the utmost importance in ruminants, the signals and mechanisms which regulate adiposity for fattening have been studied and characterized by many different approaches. Adipogenesis in the adipose tissues of ruminants is triggered and modulated by several factors/genes, some of which (conjugated linoleic acid, tumor necrosis factor‐α and adipogenin) have been examined with respect to adipogenesis in ruminants by numerous researchers, including those in our group. The purpose of this article was to describe recent advances and insights into the molecular regulating processes of preadipocyte, adipocyte and adipose tissues in ruminants.     

Effect of cyclosporin on distribution of methotrexate into the brain of rats

The effect of the antitumor drug, methotrexate (MTX), which is applied to brain tumors, is restricted by the blood-brain barrier (BBB), which is composed of P-glycoprotein (P-gp) and multidrug resistance associated protein (MRP). We, therefore, studied if a potent P-gp and MRP modulator, cyclosporin A (CysA), can modulate the MTX concentration in the rat brain. If it can, which route is more effective, intravenous or intrathecal? We intravenously or intrathecally administered MTX to rats with or without CysA. After 6 hr, brains and cerebrospinal fluid (CSF) were sampled, and their MTX concentrations were compared. Each MTX concentration was determined by high-performance liquid chromatography with UV detection. CysA had no significant affect on the MTX concentration in the brain or CSF when MTX was intravenously injected. In contrast, when MTX was intrathecally administered, CysA had a larger effect on the MTX concentration in the brain than in the CSF. This indicates CysA potentiated the brain MTX concentration when MTX was intrathecally administered. It is suggested that CysA did not potentiate the distribution of MTX from blood into the brain, but instead potentiated the distribution of MTX from CSF into the brain. Since chemicals in CSF generally diffuse into the brain easily, CysA probably inhibited the excretion of MTX from the brain. This could be caused by inhibition of P-gp or MRP at the BBB. Therefore, CysA can be a useful tool to achieve an appropriate MTX concentration in brain.     

A globotetraosylceramide (Gb4) receptor-based ELISA for quantitative detection of Shiga toxin 2e

Currently, no simple assays are available for routine quantitative detection of Escherichia coli-produced Shiga toxin 2e (Stx2e) that causes porcine edema disease. Here, we present a novel quantitative detection method for Stx2e based on the measurement of Stx2e binding to the specific globotetraosylceramide (Gb₄) receptor by ELISA (Gb₄-ELISA). No cross-reactivity was found with the other Shiga toxins Stx1 and Stx2, indicating high specificity. When the recombinant Stx2e B subunit (Stx2eB) was used, the absorbance measured by Gb₄-ELISA increased linearly with Stx2eB concentration in the range of 20–2,500 ng/ml. The Gb₄-ELISA method can be easily performed, suggesting that it would be a useful diagnostic tool for porcine edema disease.     

The high prevalence of hepatitis E virus infection in wild boars in Ibaraki Prefecture,Japan

Hepatitis E virus (HEV) is known as a causative agent of zoonosis and food poisoning. Pigs and some species of wild animals, including wild boar, are known to be a reservoir of HEV. In this study, we investigated the situation regarding HEV infection in wild boars in Ibaraki Prefecture, Japan. Serum, liver and feces samples from 68 animals were collected, and the presence or absence of HEV genomic RNA and HEV antibodies were analyzed. The viral genome was detected in samples from 7 (10.3%) animals, with all HEVs classified as genotype 3, subtype 3b. HEV antibodies were detected in samples from 28 (41%) animals. This report demonstrates for the first time the high prevalence of HEV infection in wild boars in Ibaraki Prefecture.     

Analysis of the effect of feedback feeding on the farm-level occurrence of porcine epidemic diarrhea in Kagoshima and Miyazaki Prefectures,Japan

When a large-scale epidemic of porcine epidemic diarrhea (PED) occurred in 2013 in Japan, feedback feeding (feeding feces and gut tissues of infected piglets) was attempted to impart immunity to sows and immunize nursing piglets via breastfeeding. This study evaluated the effect of feedback feeding on PED control at 172 farms in Kagoshima and Miyazaki Prefectures. Univariable and multivariable generalized linear models were used to analyze the associations between conduct of feedback feeding and damage from the outbreak (outbreak period and the number of piglet deaths) at the farm level. The within-farm outbreak period shortened over time after the regional outbreak began on Kyushu Island (P=0.009) and was longer on large-scale farms (mean 66.0 days, P=0.003) than small-scale farms (29.4 days) and on farms that used feedback feeding (145.2 days, P=0.059) than those that did not (66.0 days). The number of dead piglets decreased over time since the first regional case (P<0.001) and was higher at farrow-to-finish farms (3.8 piglets/sow, P<0.001) than reproduction farms (0.7 piglets/sow). The effect of feedback feeding on the number of dead piglets was not significant, but its interaction term with farm style had a significant effect (5.0 more piglet deaths at reproduction farms than fallow-to-finish farms, P=0.001). These results suggest that feedback feeding made the damage from PED worse, though it was well established at a later stage of the regional PED epidemic.     

Morphometric evaluation of canine hepatocellular carcinoma using computed tomography: a promising tool for predicting malignancy

The size of canine focal liver lesions (FLLs) is known to be one of the predicting criteria for malignancy. However, there are discrepancies for the measurement of maximum lesion size, resulting in contradicting results among studies and incidences of false positive outcomes. Thus far, the morphometric changes of FLLs for distinguishing malignancy from benignancy remains undocumented. This study aimed to investigate morphometric characteristics of FLLs using computed tomography (CT). CT images of 40 dogs with histopathological confirmation of 49 liver lesions, including 39 hepatocellular carcinomas and 10 nodular hyperplasias were retrospectively reviewed. The morphometric parameters including size (long and short axis diameters measured on transverse image), shape (measured by long to short axis (L/S) ratio), volume, and surface appearance of a liver lesion were evaluated using univariate and stepwise multivariate analyses, respectively. The results of univariate analysis showed that long and short axis diameters, L/S ratio, volume, and surface appearance of a lesion were significantly different between hepatocellular carcinomas and nodular hyperplasias. Multivariate analysis revealed that short axis diameter (>3.30 cm; odds ratio (OR): 36.1, 95% confidence interval (CI): 3.36–387.05, P=0.0031) and L/S ratio (>1.23; OR: 18.1, 95% CI: 1.61–205.12, P=0.0191) were independent predictors of malignancy, with the area under the curve of 0.9154. These results suggest that the combination of short axis diameter and L/S ratio is a promising tool for predicting liver malignancy with outstanding discriminating ability.     

Tempe Consumption Modulates Fecal Secondary Bile Acids, Mucins, Immunoglobulin A, Enzyme Activities, and Cecal Microflora and Organic Acids in Rats

The present study investigated the effect of dietary tempe, a fermented soy product, on the colonic environment of rats fed high-fat (HF, 30 % fat; experiment 1) or low-fat (LF, 6 % fat; experiment 2) diets. Growing male rats were fed the experimental diets with or without 25 % tempe for 21 days. Tempe consumption slightly but significantly increased the growth of rats fed both the HF and LF diets (P?<?0.05). With both the HF and LF diets, dietary tempe markedly reduced a harmful fecal secondary bile acid, lithocholic acid (a risk factor of colon cancer) (P?<?0.05), and markedly elevated fecal mucins (indices of intestinal barrier function) and immunoglobulin A (IgA, an index of intestinal immune function) (P?<?0.05). With the HF diet, dietary tempe increased cecal acetate, butyrate, propionate, and succinate concentrations (P?<?0.05). Analysis of the profile of cecal microflora revealed lower Bacteroides and higher Clostridium cluster XIVa levels in the tempe group of rats fed the HF diet (P?<?0.05). Compared with the control group, the fecal activity of β-glucosidase was markedly higher in the tempe group (P?<?0.05), while that of urease was lower (P?<?0.05) with both the HF and LF diets. The present results suggest that tempe consumption modulates the colonic environment in rats.     

Simple method for isolation of glyceraldehyde 3‐phosphate dehydrogenase and the improvement of myofibril gel properties

Porcine glycoliytic enzyme, glyceraldehyde 3‐phosphate dehydrogenase (G3PD) was prepared effectively by a combination of ethylene diamine tetra‐acetate (EDTA) pretreatment and affinity purification. After salting out of porcine sarcoplasmic proteins (SP) with ammonium sulfate at 75% saturation, the obtained supernatant (SP‐f3) was treated with EDTA, leaving G3PD in the supernatant (G3PD‐E) and most other SPs in the precipitate. At that time, the separation of G3PD‐E required more than 20 mmol/L EDTA. G3PD‐E was then subjected to affinity purification by batchwise method using blue‐sepharose CL‐6B, and purified G3PD (G3PD‐AP) was obtained using 2 mol/L potassium chloride (KCl) as an eluent. Texture analysis showed that the hardness, adhesiveness and gumminess of the myofibril gel at 0.2‐mol/L NaCl increased with the addition of G3PD‐AP. Scanning electron microscopy revealed that the G3PD‐AP reinforced the gel network of the myofibril. However, scanning electron micrograph analysis showed that the network‐structure of the gel by the addition of G3PD‐AP developed in a different manner from that by adding 0.6 mol/L NaCl. These results showed that glycolytic enzyme, G3PD, contributes to the improvement of the rheological properties of meat products.     

An Acute-phase Protein as a Regulator of Sperm Survival in the Bovine Oviduct: Alpha 1-acid-glycoprotein Impairs Neutrophil Phagocytosis of Sperm In Vitro

We have previously shown that polymorphonuclear neutrophils (PMNs) are present in bovine oviduct fluid under physiological conditions, and that the oviduct provides a microenvironment that protects sperm from phagocytosis by PMNs. Alpha 1-acid glycoprotein (AGP) is a major acute-phase protein produced mainly in the liver that has immunomodulatory functions. AGP mRNA is expressed in extrahepatic organs, such as the lung, kidney, spleen, lymph node, uterus, and ovary. Therefore, in this study, we investigated, 1) the local production of AGP in the bovine oviduct, 2) the effect of AGP on the phagocytic activity of PMNs for sperm and superoxide production and 3) the impact of AGP desialylation on the PMN phagocytosis of sperm. The AGP gene was expressed in cultured bovine oviduct epithelial cells (BOECs) and AGP protein was detected in oviduct fluid. Preexposure of PMNs to AGP at physiological levels impaired PMN phagocytosis for sperm and superoxide generation. The desialylation of AGP eliminated these suppressive effects of AGP on PMN. Scanning electron microscopy revealed that AGP drastically reduced the formation of DNA-based neutrophil extracellular traps (NETs) for sperm entanglement. Additionally, AGP dose-dependently stimulated BOECs to produce prostaglandin E₂ (PGE₂) which has been shown to partially contribute to the regulation of sperm phagocytosis in the bovine oviduct. AGP and PGE₂ at concentrations detected in the oviducts additively suppressed sperm phagocytosis by PMNs. These results provide evidence that locally produced AGP may be involved in protecting sperm from phagocytosis by PMNs in the bovine oviduct.