Diagnosis and characterization of duck beak atrophy and dwarfism syndrome in Chongqing of China.

Duck beak atrophy and dwarfism syndrome (BADS) is a newly emerged disease in China since 2015. In October 2017, an unidentified disease occurred in Cherry Valley ducks, Chongqing municipality, the southwest of China. The affected birds showed short beak and growth retardation clinical signs. The disease caused approximately 20.00% morbidity and serious weight loss due to retarded growth. In order to identify the causative agent of BADS, liver, spleen, lung and heart samples were collected for virus isolation, hemagglutination test, PCR identification, and partial gene sequencing. The isolated virus was tentatively named SC16. Hemagglutination test indicated that the virus was negative to chicken red blood cells. Based on the PCR and sequencing results, the causative agent of BADS was a novel duck-origin goose parvovirus (DGPV) while no another co-infection pathogen was found in this case. Further analysis could provide insights into the control strategies of DGPV in ducks.

Pathogenicity of Five Strains of Toxoplasma gondii from Different Animals to Chickens.

Toxoplasma gondii is a protozoan parasite with a broad range of intermediate hosts. Chickens as important food-producing animals can also serve as intermediate hosts. To date, experimental studies on the pathogenicity of T. gondii in broiler chickens were rarely reported. The objective of the present study was to compare the pathogenicity of 5 different T. gondii strains (RH, CN, JS, CAT2, and CAT3) from various host species origin in 10-day-old chickens. Each group of chickens was infected intraperitoneally with 5×10(8), 1×10(8), 1×10(7), and 1×10(6) tachyzoites of the 5 strains, respectively. The negative control group was mockly inoculated with PBS alone. After infection, clinical symptoms and rectal temperatures of all the chickens were checked daily. Dead chickens during acute phage of the infection were checked for T. gondii tachyzoites by microscope, while living cases were checked for T. gondii infection at day 53 post-inoculation (PI) by PCR method. Histopathological sections were used to observe the pathological changes in the dead chickens and the living animals at day 53 PI. No significant differences were found in survival periods, histopathological findings, and clinical symptoms among the chickens infected with the RH, CN, CAT2, and CAT3 strains. Histopathological findings and clinical symptoms of the JS (chicken origin) group were similar to the others. However, average survival times of infected chickens of the JS group inoculated with 5×10(8) and 1×10(8) tachyzoites were 30.0 and 188.4 hr, respectively, significantly shorter than those of the other 4 mammalian isolates. Chickens exposed to 10(8) of T. gondii tachyzoites and higher showed acute signs of toxoplasmosis, and the lesions were relatively more severe than those exposed to lower doses. The results indicated that the pathogenicity of JS strain was comparatively stronger to the chicken, and the pathogenicity was dose-dependent.

Reduction of inflammatory responses by L-serine treatment leads to neuroprotection in mice after traumatic brain injury.

This study was designed to evaluate the neuroprotective effect of l-serine and the underlying mechanisms in mice after traumatic brain injury (TBI) induced using a weight drop model. The mice were intraperitoneally injected with l-serine 3 h after TBI and then injected twice each day for 7 days or until the end of the experiment. The neurological severity score, brain water content, lesion volume, and neurone loss were determined. The levels of TNF-α, IL-1ß, IL-6, and IL-10 and the number of GFAP- and Iba-1-positive cells and activated caspase-3-positive neurones in the brain tissue ipsilateral to TBI were also measured. Simultaneously, the influences of l-serine on these variables were observed. In addition, the expression of glycine receptors and l-serine-induced currents were measured. We found l-serine treatment: 1) decreased the neurological deficit score, brain water content, lesion volume, and neurone loss; 2) inhibited activated caspase-3; and 3) reduced the levels of TNF-α, IL-1ß and IL-6 and the number of GFAP- and Iba-1-positive cells. The effects of l-serine were antagonised by the administration of strychnine, an antagonist of glycine receptors. In addition, we found that glycine receptors were expressed mainly in the cortical neurones but less in the astrocytes or microglial cells, and l-serine activated these receptors and induced strychnine-sensitive currents in these neurones. In conclusion, l-serine induces the activation of glycine receptors, which alleviates neuronal excitotoxicity, a secondary brain injury process, thereby reduces the activation of astrocytes and microglial cells and secretion of proinflammatory cytokines and inhibits neuronal apoptosis. Thus, l-serine treatment leads to neuroprotection of brain tissue through reducing inflammatory responses and improves recovery of the neurological functions in mice after traumatic brain injury.

Improvement in the neural stem cell proliferation in rats treated with modified "Shengyu" decoction may contribute to the neurorestoration.

ETHNOPHARMACOLOGICAL RELEVANCE: "Shengyu" decoction, a traditional Chinese medicine, has been used to treat diseases with deficit in "qi" and "blood". The modified "Shengyu" decoction (MSD) used in the present study was designed to treat traumatic brain injury (TBI) on the basis of the "Shengyu" decoction, in which additional four herbs were added. Many ingredients in these herbs have been demonstrated to be effective for the treatment of brain injury. The present study was performed to evaluate the neurorestorative effect and the underlying mechanisms of MSD on the rat brain after a TBI. MATERIALS AND METHODS: TBI was induced in the right cerebral cortex of adult rats using Feeney's weight-drop method. Intragastrical administration of MSD (1.0 ml/200 g) was begun 6h after TBI. The neurological functions and neuronal loss in the cortex and hippocampus were determined. The levels of nerve growth-related factors GDNF, NGF, NCAM, TN-C, and Nogo-A and the number of GFAP(+)/GDNF(+), BrdU(+)/nestin(+), BrdU(+)/NeuN(+) immunoreactive cells in the brain ipsilateral to TBI were also measured. Moreover, the influences of MSD on these variables were observed at the same time. RESULTS: We found that treatment with MSD in TBI rats ameliorated the neurological functions and alleviated neuronal loss. MSD treatment elevated the expression of GDNF, NGF, NCAM, and TN-C, and inhibited the expression of Nogo-A. Moreover, MSD treatment increased the number of GFAP(+)/GDNF(+), BrdU(+)/nestin(+), and BrdU(+)/NeuN(+) immunoreactive cells in the cortex and hippocampus. CONCLUSION: The present results suggest that MSD treatment in TBI rats could improve the proliferation of neural stem/progenitor cells and differentiation into neurons, which may facilitate neural regeneration and tissue repair and thus contribute to the recovery of neurological functions. These effects of modified "Shengyu" decoction may provide a foundation for the use of MSD as a prescription of medicinal herbs in the traditional medicine to treat brain injuries in order to improve the neurorestoration.

Investigation on the co-infections of Toxoplasma gondii with PRRSV, CSFV or PCV-2 in swine in part of China.

The objective of the present investigation was to estimate the prevalence of Toxoplasma gondii infection and co-infection with porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever virus (CSFV) and porcine circovirus type 2 (PCV-2) in pigs in China. A total of 372 tissues or serum samples collected from pigs distributed in 9 provinces/municipalities of China during the period from February 2011 to November 2012 were assayed for T. gondii antigens and antibodies using enzyme linked immunosorbent assay (ELISA) technique, while the PCR was designed for the detection of the PRRSV, CSFV and PCV-2, respectively. The total positive rate of T. gondii, PRSSV, CSFV and PCV-2 was 9.14% (34/372), 50.00% (186/372), 37.10% (138/372) and 3.23% (12/372), respectively. Among the 34 T. gondii positive samples, 26 samples were simultaneously infected with T. gondii and viruses, while the remaining eight samples were infected with T. gondii alone. In addition, the co-infection rate of T. gondii with PRSSV, T. gondii with PRSSV and CSFV, T. gondii with PRSSV and PCV-2, T. gondii with CSFV and PCV-2, T. gondii with PRSSV, CSFV and PCV-2 was 1.61% (6/372), 4.03% (15/372), 0.27% (1/372), 0.27% (1/372) and 0.81% (3/372), respectively. The results of the present survey revealed that PRRSV and CSFV were the common pathogens co-existing with porcine toxoplasmosis in China, and both of them could increase the chances of T. gondii infection in pig. This is the first report of T. gondii co-infections with viruses in pigs. It is very important to understand the interactions of parasite and virus, and can be used as reference data for the control and prevention of co-infections of T. gondii and viruses in pigs.

L-serine treatment may improve neurorestoration of rats after permanent focal cerebral ischemia potentially through improvement of neurorepair.

The present study was conducted to clarify whether treatment with L-serine can improve the brain repair and neurorestoration of rats after permanent middle cerebral artery occlusion (pMCAO). After pMCAO, the neurological functions, brain lesion volume, and cortical injury were determined. GDNF, NGF, NCAM L1, tenascin-C, and Nogo-A levels were measured. Proliferation and differentiation of the neural stem cells (NSCs) and proliferation of the microvessels in the ischemic boundary zone of the cortex were evaluated. Treatment with L-serine (168 mg/kg body weight, i.p.) began 3 h after pMCAO and was repeated every 12 h for 7 days or until the end of the experiment. L-Serine treatment: 1) reduced the lesion volume and neuronal loss; 2) improved the recovery of neurological functions; 3) elevated the expression of nerve growth-related factors; and 4) facilitated the proliferation of endogenous NSCs and microvessels activated after pMCAO and increased the number of new-born neurons. 5) D-cycloserine, an inhibitor of serine hydroxymethyltransferase, blunted the effects of L-serine on NSC proliferation, differentiation, microvascular proliferation. In conclusions, L-serine treatment in pMCAO rats can reduce brain injury and facilitate neurorestoration which is partly associated with the improvement of proliferation of NSCs and microvessels, reconstruction of neurovascular units and resultant neurorepair. The effects of L-serine on endogenous NSC proliferation and microvascular proliferation are partly mediated by the action of L-serine as a substrate for the production of one-carbon groups used for purine and pyrimidine synthesis and modulation of the expression of some nerve growth-related factors.

The neuroprotective effect of modified "Shengyu" decoction is mediated through an anti-inflammatory mechanism in the rat after traumatic brain injury.

ETHNOPHARMACOLOGICAL RELEVANCE: "Shengyu" decoction, a traditional Chinese medicine, has been used to treat diseases with deficit in "qi" and "blood" induced frequently by profound loss of blood or by long sores with heavy pus, in which a potential anti-inflammatory effect is implied. The modified "Shengyu" decoction (MSD) used in the present study was designed on the basis of the "Shengyu" decoction, additional four herbs were added in. Many ingredients in these herbs have been demonstrated to be anti-inflammatory and thus MSD may be used for the treatment of traumatic brain injury (TBI). To evaluate the neuroprotective effect and the underlying mechanisms of MSD on the rat brain after TBI. MATERIALS AND METHODS: TBI was induced in the right cerebral cortex of male adult rats using Feeney's weight-drop method. The rats were administered a gavage of MSD (0.5, 1.0 or 2.0 ml/200 g) 6h after TBI. The neurological functions, brain water content, contusion volume, and neuron loss were determined. The levels of TNF-α, IL-1ß, IL-6, and IL-10 and the number of GFAP- and Iba1-positive cells in the brain ipsilateral to TBI were also measured. Moreover, the influence of MSD on these variables was observed at the same time. RESULTS: The neurological deficits, brain water content, and neuron loss were significantly reduced after 1.0 or 2.0 ml/200 g of MSD treatment but not after 0.5 ml/200 g. In addition, treatment with MSD (1.0 ml/200 g) significantly increased the level of IL-10 and reduced the level of TNF-α and IL-1ß and the number of GFAP- and Iba1-positive cells after TBI. However, the contusion volume of brain tissue and the expression of IL-6 were not significantly changed. CONCLUSION: MSD may be a potential therapeutic for the treatment of TBI because MSD alleviated secondary brain injury induced by TBI. In addition, MSD inhibited the inflammatory response through reducing the expression of inflammatory cytokines and the activation of microglial cells and astrocytes in the brain tissue of rats after TBI. Therefore, a potential anti-inflammatory mechanism of the "Shengyu" decoction was confirmed, which may be one of the main reasons of "Shengyu" decoction used to treat diseases with obvious inflammatory responses.

Improvement in regional CBF by L-serine contributes to its neuroprotective effect in rats after focal cerebral ischemia.

To investigate the mechanisms underlying the neuroprotective effect of L-serine, permanent focal cerebral ischemia was induced by occlusion of the middle cerebral artery while monitoring cerebral blood flow (CBF). Rats were divided into control and L-serine-treated groups after middle cerebral artery occlusion. The neurological deficit score and brain infarct volume were assessed. Nissl staining was used to quantify the cortical injury. L-serine and D-serine levels in the ischemic cortex were analyzed with high performance liquid chromatography. We found that L-serine treatment: 1) reduced the neurological deficit score, infarct volume and cortical neuron loss in a dose-dependent manner; 2) improved CBF in the cortex, and this effect was inhibited in the presence of apamin plus charybdotoxin while the alleviation of both neurological deficit score and infarct volume was blocked; and 3) increased the amount of L-serine and D-serine in the cortex, and inhibition of the conversion of L-serine into D-serine by aminooxyacetic acid did not affect the reduction of neurological deficit score and infarct volume by L-serine. In conclusion, improvement in regional CBF by L-serine may contribute to its neuroprotective effect on the ischemic brain, potentially through vasodilation which is mediated by the small- and intermediate-conductance Ca(2+)-activated K(+) channels on the cerebral blood vessel endothelium.

[Effects of combined fertilization of N, P, and K on nicotine content of filling type flue-cured tobacco].

An orthogonal regression field experiment was conducted to study the effects of combined fertilization of N, P, and K on the nicotine content in the upper leaves of filling type flue-cured tobacco (Nicotiana tobacum) variety "Longjiang 911" from Northeast China. The regression effect models of N, P, and K fertilization rates and upper leaf nicotine content were established, and the effects of the fertilization rates and their interactions were analyzed. Based on these, an optimized NPK fertilization scheme was drawn up to reduce the nicotine content in the upper leaves of "Longjiang 911". The model analyses showed that the nicotine content in the upper leaves of "Longjiang 911" decreased after an initial increase with the increasing fertilization rate of N, increased with the increasing fertilization rate of P, and had a sharp decrease with the increasing fertilization rate of K. The two-factor effects of NKP on the nicotine content were in the order of NK >PK>NP. Within a certain range of fertilization rates, NP and PK had negative correlations with the nicotine content, suggesting the antagonistic effects between N and P and between P and K, while NK was on the contrary, suggesting the synergistic effects between N and K. A comprehensive analysis on the regression effect models of N, P, and K fertilization rates and upper leaf nicotine content showed that the basal fertilization rates of N, P, and K for the tobacco production on warp soil were recommended as 33.5-47.8 kg x hm(-2), 40.2-63.6 kg x hm(-2), and 78.0-119.6 kg x hm(-2), respectively.