Variability in chewing, ruminal fermentation, digestibility and bacterial communities between subacute ruminal acidosis-susceptible and acidosis-tolerant sheep.

Sorting behaviour is a common phenomenon observed in ruminants when they are provided with a total mixed ration, which contributes to variations in the severity of subacute ruminal acidosis (SARA). Pelleted total mixed ration (PTMR) reduces sorting, but high-grain content increases acidosis risk. However, whether the variability in the severity of SARA exists in sheep fed the same high-grain PTMR is less understood. This study aimed to investigate SARA variability among individual sheep offered a high-grain PTMR, considering chewing activity, ruminal fermentation, bacterial communities and nutrient digestibility. Twenty ruminally cannulated male Hu sheep were individually housed in cages and fed a PTMR comprising 80% concentrate mix and 20% roughage. A 14-day adaptation period to the diet and facilities was provided before a 10-day sample collection period. Continuous monitoring of ruminal pH was conducted for 48 h, during which time chewing activity was also recorded. Ruminal fluid samples were collected for analysis of volatile fatty acid and microbial DNA extraction. Faecal samples were collected to measure nutrient digestibility. Based on their acidosis index, the sheep were classified into two groups: SARA-susceptible group (n = 6) and SARA-tolerant group (n = 6). The SARA-susceptible sheep exhibited a lower ruminal mean pH and minimum pH than the SARA-tolerant sheep (P < 0.05). Additionally, the SARA-susceptible group increased the acidosis index, duration and areas of pH below 5.8 and 5.6 compared to the SARA-tolerant group (P < 0.05). The SARA-susceptible group also exhibited a longer ruminating time than the SARA-tolerant group (P < 0.05). The SARA-susceptible group exhibited a tendency to increase the relative abundance of Firmicutes (P = 0.089), while simultaneously decreasing the copy number of Fibrobacter succinogenes in the rumen, as well as the digestibility of NDF and ADF compared to the SARA-tolerant group (P < 0.05). The acidosis index was found to be positively correlated with ruminating time (min/kg DM intake (DMI)) and total chewing time (min/kg DMI), but negatively correlated with the copy number of Fibrobacter succinogenes and Ruminococcus albus in the rumen. These findings indicate that there exists variability in the SARA severity among sheep when fed a high-grain PTMR, as evidenced by varied chewing activity, bacterial communities and nutrient digestibility. Ruminating time, total chewing time per kilogram of DMI as well as the copy number of Fibrobacter succinogenes and Ruminococcus albus in the rumen hold potential as indicators for assessing the severity of SARA.

[Pregnancy-related pelvic ring disease and its treatment].

Pregnancy-related pelvic ring disease brings great suffering to pregnant women, including the separation of the pubic symphysis and sacroiliac joint pain. Hormonal changes leading to ligamentous laxity is the main reason for Pregnancy-related pelvic ring disease. In normal pregnant cases, and the physiologic widening at the symphysis is about 3-7 mm. When the widening of the symphysis is more than 10 mm, it may lead to symptoms and need active treatment. Currently the diagnosis of the pubic symphysis separation is based on the clinical symptoms and signs. The treatment of acute pubic symphysis separation bases on conservative therapy, includes bed rest and physical therapy. But when the widening of the symphysis is more than 4 cm, the surgery intervention may be a good treatment. If the conservative treatment is not obviously effective, the surgery consists of plate fixation in the pubic symphysis and sacroiliac screw fixation. Other indications for the surgical intervention include inadequate reduction, recurrent diastasis, intractable symptoms, and open rupture.

A double three-step theory of brain metastasis in mice: the role of the pia mater and matrix metalloproteinases.

The brain is frequently affected by the spread of lung cancer, and haematogenous metastasis is a common route to brain metastasis. We therefore developed an isogenic brain metastasis model of lung cancer to use the Lewis lung carcinoma cell line and analysed dynamics of neoplastic cells after extravasation. Histological analysis revealed two characteristic patterns: metastatic foci exhibiting an angiocentric pattern were designated 'perivascular proliferations'; neoplastic cells infiltrating the brain parenchyma were designated 'invasive proliferations'. Electron microscopic observation of perivascular proliferations showed that neoplastic cells were confined to the perivascular space. In invasive proliferations, however, fragments of collagen fibre were observed in the gaps between neoplastic cells, indicating that the neoplastic cells had disintegrated the pia-glial membrane. We analysed the expressions of matrix metalloproteinase-2 (MMP-2) and MMP-9 by using both immunohistochemical analysis and real-time polymerase chain reaction analysis. MMP-2 expression was significantly higher in invasive proliferations. MMP-9 expression was significantly higher in day 7, but there was no significant difference in day 11. The pia-glial membrane and perivascular space are the barriers that neoplastic cells must overcome to infiltrate the brain. In conclusion, our findings suggest that brain metastasis requires two distinct processes.

Technology of the divalent engineered diarrhea vaccine (K88, K99) production by high cell density fermentation and the antigen overexpression.

This paper describes the production of divalent K88, K99 antigens by high cell density fermentation and gene overexpression. The cell density reached above 40 at A600nm and the antigens were at 2(12) level. The thousands dosage of the vaccine can be made by using 10 I broth of the fermentation. The stability of the plasmid showed that about 30 percent of the bacteria lost its plasmid after 20 h fermentation. It was found that the antigens were overexpressed and located in both the pili of E. coli and in the medium in equal quantities. It means that the expression and regulation of the genes of K88, K99 may be different from the wild type of enterotoxingenic E. coli. A large number of the vaccinated pregnant sow showed that the piglets were effectively protected from the infection of enterotoxingenic E. coli. The results indicated that the large quantities requirement of the vaccine could be provided by using a small fermenter. This vaccine consists of two forms of the antigen K88, K99 which, when present in the pili as well as the medium, is more favorable to stimulate the production of antibody in the colostrum of pregnant sow.

Effect of sodium artesunate on malaria infected human erythrocytes.

Oxidative stress in malaria infected human erythrocytes is augmented and the anti-oxidant system is attenuated as compared with normal RBC's. Exacerbation of intra-erythrocytic oxidative stress might provide a means to kill the parasites. Sodium artesunate (SA), an effective Chinese anti-malaria drug, markedly increased the levels of active oxygen species and production of malonyldialdehyde in normal red blood cells and, to a greater extent, in malaria infected red blood cells. SA caused a remarkable decrease of unsaturated fatty acids content in normal red blood cell membrane. These suggest that the anti-oxidative system in red blood cells infected with malaria is jeopardized. Certain active oxygen species generated and accumulated in such red blood cells might in turn kill the parasites. SA augmented intracellular O2-. and H2O2 production, and this may partly account for its antimalaria action.