Three species of Aeromonas (A. dhakensis, A. hydrophila and A. jandaei) isolated from freshwater crocodiles (Crocodylus siamensis) with pneumonia and septicemia

Hundreds of farmed Siamese crocodiles (Crocodylus siamensis) died during July 2016 at a farm in Wenchang, Hainan, China. In two necropsied crocodiles, we observed symptoms of dermatorrhagia, hepatomegaly and hepatic congestion. Pulmonitis was diagnosed by pulmonary congestion and pulmonary fibrinous exudate. Septicaemia was diagnosed by isolation of three Aeromonas species from blood and visceral tissues; A. dhakensis, A. hydrophila and A. jandaei were identified by biochemical and molecular tests. We used a zebrafish model to determine the half-maximal lethal dose (LD₅₀ ), and A. dhakensis was found to be the most virulent species, with an LD₅₀ of 8·91 × 10⁵ CFU per ml. The results of a drug sensitivity test indicated that these species were sensitive to 11 antibiotics. This is the first report of A. dhakensis, A. hydrophila and A. jandaei being isolated from a mixed infection in Siamese crocodiles. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, we isolated three species of Aeromonas (A. dhakensis, A. hydrophila and A. jandae) from farmed Siamese crocodiles with fatal fibrinous pneumonia and septicaemia. This is the first description of a mixed infection with three Aeromonas species among captive crocodilians.

Genetic analysis of skinfold thickness and its association with body condition score and milk production traits in Chinese Holstein population

The skin has many important roles in dairy cattle, and skinfold thickness could be used as an indicator of body fat deposition. The objectives of this study were to estimate genetic parameters of skinfold thickness and to explore its association with body condition score (BCS) and milk production traits in a Chinese Holstein population. Skinfold thicknesses over the neck (STN) and the last rib (STR), BCS, and test-day records of milk production traits were available for 6,416 lactating Holstein cows in the summers of 2015 and 2016 in Beijing, China. Multi-trait animal models were used to estimate variance and covariance components using the DMU software. The average STN was 7.15 ± 1.28 mm, and the average STR was 11.76 ± 1.95 mm (mean ± standard deviation). Estimated heritability was 0.13 ± 0.03 for STN and 0.26 ± 0.04 for STR. We detected a high genetic correlation (0.79 ± 0.08; heritability ± standard error) between STN and STR. Genetic correlations between skinfold thickness and BCS were low to moderate: 0.18 between STR and BCS, and 0.33 between STN and BCS. Genetic correlations between skinfold thickness and milk yield, milk fat percentage, and milk protein percentage were negligible, ranging from -0.02 to 0.15. Collectively, skinfold thickness is characterized as a trait with moderate heritability. Skinfold thickness is sensitive to changes in body condition or fat deposition across parities and lactation stages in milking cows, and we confirmed the complementary nature of skinfold thickness and BCS genetically as well as phenotypically by comparing their changing trends throughout lactation and across lactations. The use of skinfold thickness, together with BCS, can assist in the monitoring of changes in body fat deposition to achieve higher management precision.

Effects of applying lactic acid bacteria and propionic acid on fermentation quality, aerobic stability and in vitro gas production of forage-based total mixed ration silage in Tibet

Total mixed ration (TMR) silage technology has been practically used to feed ruminants in Tibet. This study was conducted on forage-based TMR to evaluate the effects of supplementing lactic acid bacteria and propionic acid on its fermentation characteristics, aerobic stability and in vitro gas production kinetics and digestibility. Experimental treatments included four variants: (1) TMR supplemented with 10 mL deionised water per kilogram fresh matter (Control); (2) TMR supplemented with 1 × 106 cfu/g Lactobacillus plantarum (L); (3) TMR supplemented with 0.3% propionic acid (P); (4) TMR supplemented with a combination of 1 × 106 cfu/g Lactobacillus plantarum and 0.3% propionic acid (LP). The latter three additives were first dissolved in deionised water and then applied as a water solution (10 mL/kg fresh matter). All treatments were ensiled in laboratory-scale silos for 45 days, and then exposed to air for 12 days to evaluate the aerobic stability of TMR silage. Further, the four experimental treatments were fermented with buffered rumen fluid to measure in vitro gas production and nutrients’ digestibility. The results indicated that all TMR silages possessed good fermentation characteristics with low pH values (<4.18) and ammonia nitrogen (NH3-N) contents (<100 g/kg total nitrogen), and high lactic acid contents (>66 g/kg DM) and Flieg points (>80). The addition of L and LP stimulated a more efficient homofermentation of TMR silage than in the variant without L, as evidenced by higher ratios of lactic:acetic acid. The addition of P had no effect (P > 0.05) on lactic acid production of TMR silage compared with the Control, whereas it decreased NH3-N content (P < 0.05). Under aerobic conditions, L silage showed less aerobic stability compared with the Control silage, whereas P and LP silages were more (P < 0.05) aerobically stable. Compared with the Control, all additives elevated (P < 0.05) the total gas production and in vitro dry matter digestibility of TMR silages. L silage had a higher (P < 0.05) in vitro neutral detergent fibre digestibility than the Control silage. Data obtained from this study suggested that TMR silage based on oat and common vetch can be well conserved with or without additives. Lactic acid bacteria were compatible with propionic acid, and addition of lactic acid bacteria together with propionic acid can improve the fermentation quality, aerobic stability and in vitro dry matter digestibility of TMR silage.

Effects of fibrolytic enzymes and isobutyrate on ruminal fermentation, microbial enzyme activity and cellulolytic bacteria in pre- and post-weaning dairy calves

The objective of the present study was to evaluate the effects of fibrolytic enzymes (FE, containing 160 units of cellulase and 4000 units of xylanase) or isobutyrate (IB) supplementation on ruminal fermentation, microbial enzyme activity and cellulolytic bacteria in dairy calves. Forty-eight Holstein bull calves of 15 days of age and of 44.9 ± 0.28 kg of BW were randomly assigned to four groups in a 2 × 2 factorial arrangement. Two levels of FE (0 g (FE–) or 1.83 g per calf per day (FE+)) and IB (0 g (IB–) or 6 g per calf per day (IB+)) were added. Calves were weaned at 60-day-old and four calves were selected from each treatment at random and slaughtered at 45 and 90 days of age. There was no IB × FE interaction effect. Ruminal pH decreased with IB or FE supplementation for post-weaned calves, whereas concentrations of total volatile fatty acids and acetate increased with IB or FE supplementation for pre- and post-weaned calves. Acetate to propionate ratio increased with IB supplementation, but was unaffected by FE supplementation. Ammonia-N concentration decreased with IB or FE supplementation for pre- and post-weaned calves. For post-weaned calves, activities of CMCase increased with IB or FE supplementation, and activities of cellobiase, xylanase, pectinase, β-amylase and protease increased with IB supplementation. Populations of B. fibrisolvens and F. succinogenes for pre- and post-weaned calves and R. flavefaciens for post-weaned calves increased with IB or FE supplementation. It is suggested that ruminal fermentation and growth performance of calves was improved with IB and FE supplementation, and the combination of IB and FE has the potential to stimulate the growth of pre- and post-weaned dairy calves.

Reconfigurable vortex beam generator based on the Fourier transformation principle

A method to generate the optical vortex beam with arbitrary superposition of orbital angular momentum (OAM) on photonic chip is proposed. The components of different OAMs can be controlled by the phases of incident light based on the Fourier transformation principle. A typical device composed of nine Fourier holographic gratings is illustrated, where the OAMs of the generated optical vortex beam can be controlled on-demand from -2nd to 2nd and the working bandwidth is about 80 nm. Our work provides a feasible method to manipulate the vortex beam or detect arbitrary superposition of OAMs in the integrated photonics.

[Physiological characteristics of Echinococcus and their association with interventions against echinococcosis]

Alveolar and cystic echinococcosis are important zoonotic diseases caused by the dog/fox tapeworms of Echinococcus granulosus and E. multilocularis, which are distributed in almost whole the world. The diseases remarkably impact on the people's health and economic development of communities. Echinococcus tapeworms need two mammalian animals to complete their lifecycle. The worms undergo different developmental stages (adult, egg/oncosphere, cyst, and protoscolex). Each stage has its own distinct physiological characteristics. We summarize the characteristics and emphasize that some features that strongly impact on design of control program. Based on the lifecycle of these worms, two stages are infectious, one is egg the only stage for primarily infecting humans and intermediate host, and another stage is protoscolex, the only stage for infecting the definite hosts of the worms. Eggs are produced by the adult worms parasitized in the intestine of definite hosts. It takes 45 days for eggs becoming mature in dogs. With this feature of the tapeworm, New Zealand and Tasmania in Australia designed control program for deworming 8 times annually with an interval between deworms at 45 days. E. multilocularis takes 28-30 days in dog/fox producing mature eggs. Given that co-existence of E. granulosus and E. multilocularis in western China, a control measure so called "prepatent deworming control measure" has been used in these endemic areas with dosing worms in dogs every month. It normally takes 12-15 months for producing protosocleces in E. granulosus cysts in sheep. If meat markets attract most lambs, that is an effective measure for controlling cystic echinococcosis given that there are no protoscoleces produced from those lambs. In addition, Echinococcus has its own unique biological characteristics, such as sexual reproduction and asexual reproduction, single-cell layer structure of cyst, bidirectional development of protoscoleces induced by bile salts, and long term of infection causing host asymptomatic reaction make the parasites a models for addressing some biological and biomedical issues. And more, hydatid cyst fluid is the antigen resource for identifying diagnostic reagents; the specific gene expressed in oncospheres has been developed as an effective vaccine used for control program. With the development and application of high-throughput omics, including genomics, transcriptomics and proteomics, we can use the physiological characteristics of Echinococcus for searching diagnostic reagents, developing preventive vaccines and identify new drug targets.

Effects of concentrate-to-forage ratios and 2-methylbutyrate supplementation on ruminal fermentation, bacteria abundance and urinary excretion of purine derivatives in Chinese Simmental steers

This study evaluated the effects of dietary concentrate levels and 2-methylbutyrate (2MB) supplementation on performance, ruminal fermentation, bacteria abundance, microbial enzyme activity and urinary excretion of purine derivatives (PD) in steers. Eight ruminally cannulated Simmental steers (12 months of age; 389 ± 3.7 kg of body weight) were used in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement. Moderate-concentrate (400 g/kg diet [MC]) or high-concentrate (600 g/kg diet [HC]) diets were fed with or without 2MB (0 g/day [2MB-] or 15.0 g/day [2MB+]). Dry matter intake and average daily gain increased, but feed conversion ratio decreased with the HC diet or 2MB supplementation. Ruminal pH decreased, but total volatile fatty acid increased with the HC diet or 2MB supplementation. Molar proportion of acetate and acetate-to-propionate ratio decreased with the HC diet, but increased with 2MB supplementation. Propionate molar proportion and ruminal NH₃ -N content increased with the HC diet, but decreased with 2MB supplementation. Neutral detergent fibre degradability decreased with the HC diet, but increased with 2MB supplementation. Crude protein degradability increased with the HC diet or 2MB supplementation. Abundance of Ruminococcus albus, Ruminococcus flavefaciens, Fibrobacter succinogenes and Bufyrivibrio fibrisolvens as well as activities of carboxymethyl cellulase, cellobiase, xylanase and pectinase decreased with the HC diet, but increased with 2MB supplementation. However, abundance of Prevotella ruminicola and Ruminobacter amylophilus as well as activities of α-amylase and protease increased with the HC diet or 2MB supplementation. Total PD excretion also increased with the HC diet or 2MB supplementation. The results suggested that growth performance, ruminal fermentation, CP degradability and total PD excretion increased with increasing dietary concentrate level from 40% to 60% or 2MB supplementation. The observed diet × 2MB interaction indicated that supplementation of 2MB was more efficacious for improving growth performance, ruminal fermentation and total PD excretion with promoted ruminal bacteria abundance and enzyme activity in the MC diet than in the HC diet.

Cavitation Threshold with Respect to Dp/Dt: Evaluation in 29 Mm Bileaflet, Pyrolitic Carbon Heart Valves

A total of 15 bileaflet mechanical heart valves were studied in a pulse duplicator at the Helmholtz Institute (Aachen, Germany) under conditions approximating first, a physiological pressure curve and subsequently, a sinusoidal pressure curve. In this study Edwards-Duromedics valves of the modified specification were compared with the earlier version of the Edwards-Duromedics valve as well as with St. Jude Medical valves. Each valve was tested at a series of nine (9) conditions. At each condition, without altering the valve installation or the systemic conditions, each valve was filmed by two separate video systems: the Helmholtz Institute strobe light system and a high speed video recording system. All data, as recorded by each system, was then independently analyzed by both of the two contributing groups and subsequently compared. In this manner, it was possible to objectively verify not only the consistency of the data obtained, but to also determine the relative reliability of the methods for cavitation threshold detection.

Effects of substituting corn with steam-flaked sorghum on growth, digestion and blood metabolites in young cattle fed feedlot diets

The objective of the present study was to evaluate the effects of substituting ground corn grain with steam-flaked sorghum (SFS) grain on growth performance, nutrient utilisation and blood metabolites in beef bulls. Fifty-six Simmental beef bulls averaging 12 months of age and 356.4 ± 2.6 kg of bodyweight were randomly assigned to four groups. The treatments were control, low-SFS, medium-SFS and high–SFS, with 0, 1/3, 2/3 and 3/3 SFS grain, respectively, substituting ground corn grain of diets(dry matter (DM) basis). Diets consisted of 50% corn silage and 50% concentrate (DM basis). The average daily gain and feed conversion rate improved quadratically with increasing the proportion of SFS grain. Ruminal pH and ammonia-nitrogen (N) concentration decreased quadratically, whereas ruminal total volatile fatty acid concentration increased quadratically. Ratio of acetate to propionate decreased quadratically (P = 0.027) due to the quadratic decrease in acetate production and the quadratic increase in propionate production. Digestibilities of DM, organic matter and crude protein increased quadratically, whereas that of neutral detergent fibre and acid detergent fibre decreased quadratically. The digestible N, retention N and the retention N to digestible N ratio improved quadratically. Inclusion of SFS grain in diets quadratically increased blood concentrations of glucose, total protein, albumin and triglyceride, but quadratically decreased the concentration of urea N. The results indicated that partly substituting ground corn grain with SFS grain could improve growth performance by improving ruminal fermentation and N utilisation; the optimum substitution rate was 2/3 (DM basis).

Lysine demethylase KDM3A regulates breast cancer cell invasion and apoptosis by targeting histone and the non-histone protein p53

Invasive growth and apoptosis resistance of breast cancer cells are associated with metastasis and disease relapse. Here we identified that the lysine-specific demethylase KDM3A played a dual role in breast cancer cell invasion and apoptosis by demethylating histone and the non-histone protein p53, respectively. While inducing pro-invasive genes by erasing repressive histone H3 lysine 9 methylation, KDM3A promotes chemoresistance by demethylating p53. KDM3A suppressed pro-apoptotic functions of p53 by erasing p53-K372me1 as this methylation site is crucial for the stability of chromatin-bound p53. Unexpectedly, depletion of KDM3A was capable of reactivating mutated p53 to induce the expression of pro-apoptotic genes in breast cancer with mutant p53. Moreover, KDM3A knockdown also potently inhibited tumorigenic potentials of breast cancer stem-like cells and rendered them sensitive to apoptosis induced by chemotherapeutic drugs. Taken together, our results suggest that KDM3A might be a potential therapeutic target for human breast cancer treatment and prevention.

The effect of levodopa benserazide hydrochloride on homocysteinemia levels in patients with Parkinson's disease and treatment of hyperhomocysteinemia

OBJECTIVE

This study aims to investigate hyperhomocysteinemia (HHcy) resulted from treatment in patients with Parkinson's disease (PD) and to evaluate the therapeutic outcome of HHcy.

PATIENTS AND METHODS

Ninety-three newly diagnosed PD patients were divided into Madopar group (treated with Madopar) and non-Madopar group (not treated with Madopar). Plasma Hcy levels were measured. Five months later, 67 patients presenting with HHcy were randomly divided into treatment group (n = 34) (receiving methylcobalamin 500 µg, tid, and folic acid 50 mg, tid, orally) and control group (n = 33).  Madopar dosage was maintained in both groups. MRI examination was performed to detect cerebral ischemia and patients were evaluated by Webster's rating scale. Plasma Hcy levels were measured at 3-month follow-up. Webster's scores and MRI were performed at 6-month follow-up.

RESULTS

At the initial visit, Hcy levels of patients of Madopar group were significantly higher than those of non-Madopar group  (18.52 ± 6.48 µmol/L) vs. (15.78 ± 3.42), p < 0.05]. At 5-month follow-up, patients of the non-Madopar group presented significantly increased Hcy levels (18.97 ± 7.42 µmol/L) compare with pre-treatment Hcy levels (p < 0.05), whereas Hcy levels were slightly increased in patients of Madopar group (20.61 ± 7.87 µmol/L, p > 0.05). In the treatment group, serum Hcy levels were significantly decreased after 3-month treatment with methylcobalamin and folic acid (p < 0.01). However, serum Hcy levels were not significantly changed in patients of the control group. In addition, in the treatment group, no patient presented ischemic stroke with clinical symptoms and four patients were confirmed with new cerebral ischemic and lacunar lesions by MRI examination. However, in the control group, two ischemic strokes with clinical symptoms and 11 new cerebral ischemic and lacunar lesions were detected. Significant differences were observed between two groups (p < 0.05). Furthermore, post-treatment modified Webster scores were significantly decreased than pre-treatment scores for both groups. However, no significant differences were found between groups (p > 0.05).

CONCLUSIONS

Oral administration of Levodopa in the treatment of PD can cause HHcy, which can result in increased occurrence of ischemic stroke. Supplementation of methylcobalamin and folic acid can effectively reduce Hcy level and thereby prevent the occurrence of ischemic stroke.