[Study on reproductive toxicity of nano-cadmium sulfide with different particle sizes on male mice].

Objective: To investigate the reproductive toxicity of cadmium sulfide nanoparticles (Nano-CdS) with different particle sizes on male mice. Methods: In January 2019, 30 SPF grade male mice were randomly divided into a control group, an experimental group[CdS Ⅰ group (particle size approximately 5 nm), and a CdS Ⅱ group (particle size approximately 50 nm) ], with 10 mice in each group. The experimental group was orally gavaged with 100 mg/kg, once a day, while the control group was gavaged with an equal volume of physiological saline for 45 consecutive days. After 45 days, levels of cadmium accumulation in testis were determined directly by AAS, deformity and testicular histopathological changes were also observed. Serum testosterone levels were measured by enzyme-linked immunosorbentassay (ELISA), expression levels of P450scc, 17ß-HSD and P450c17 mRNA were determined by real-time PCR. P450c17 protein was determinated by Western Blot. Results: The histopathological results showed that the testes of the experimental group mice showed varying degrees of damage; Ultrastructural observation showed that the ultrastructure of mouse testicular cells in each experimental group showed varying degrees of mitochondrial expansion and disappearance of cristae, as well as irregular nuclear membranes. The degree of damage in CdS Ⅰ group was milder than that in CdS Ⅱ group. Compared with the control group, the cadmium content in the testes of the CdS Ⅰ and CdS Ⅱ groups significantly increased (P=0.001, 0.001), and the CdS Ⅱ group was higher than the CdS Ⅰ group (P=0.001). Compared with the control group, the levels of testosterone in the CdS Ⅰ and CdS Ⅱ groups decreased with statistical significance (P=0.001, 0.001). Real time fluorescence quantitative PCR results showed that compared with the control group, the experimental group's P450scc, 17ß-HSD. The expression levels of 17ß-HSD and P450c17 mRNA were significantly reduced, with statistically significant differences (P=0.001, 0.001, 0.001), and CdS Ⅱ group 17ß-HSD. The expression levels of 17ß-HSD and P450c17 mRNA were significantly lower than those of CdS Ⅰ group (P=0.001, 0.036). The Western Blot assay results showed that the expression levels of P450c17 protein in the testes of CdS Ⅰ and CdS Ⅱ groups of mice were significantly reduced, with statistical significance (P=0.001, 0.001) ; And the CdS Ⅱ group was significantly lower than the CdS Ⅰ group (P=0.001). According to Spearman correlation analysis, testosterone levels are correlated with P450scc, P450c17, 17ß-HSD mRNA. There is a highly positive correlation between 17ß-HSD mRNA levels, with statistically significant differences (r(s)=0.88, 0.80, 0.70, P=0.001, 0.001, 0.004) . Conclusion: Nano cadmium sulfide may induce reproductive toxicity by reducing the expression levels of key enzyme genes and enzyme protein activity in testosterone and its synthesis in mice, and the CdS Ⅱ group has a stronger toxic effect.

High efficiency and collimated terahertz pulse from ultra-short intense laser and cone target.

We propose a new, to the best of our knowledge, method to radiate a high-efficiency and collimated terahertz (THz) pulse from a relativistic femtosecond laser and cone target. Particle-in-cell simulations demonstrate that a THz source of 40 mJ, pointing at an angle of ∼20 ∘, can be generated from a laser pulse of 1.9 J by using a cone target whose open angle is 10 ∘. The peak power of the THz pulse is 1011 W. This method, which manipulates the divergence angle and the energy conversion efficiency of the THz source, should promote THz science into the extra strong region with a compact laser system.

Excretory/secretory proteins of adult Toxocara canis induce changes in the expression of proteins involved in the NOD1-RIP2-NF-κB pathway and modulate cytokine production in mouse macrophages.

Dog roundworm (Toxocara canis) is the major causative agent of toxocarosis, a parasitic disease of both veterinary and medical importance. Knowledge gaps in fundamental and applied aspects hinder the control of this important zoonotic disease. To have a better understanding of Toxocara infection and host immune responses, mouse macrophages were exposed to excretory/secretory (ES) proteins released by adult worms of T. canis in vitro. The messenger RNA transcription and protein expression of nucleotide-binding oligomerization domain-containing protein 1 (NOD1), receptor interacting protein 2 (RIP2) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in macrophages were analysed using quantitative real-time PCR (qRT-PCR) and Western blot. The levels of tumour necrosis factor alpha (TNF-ɑ), interleukin-1 beta (IL-1ß) and IL-6 released by the stimulated macrophages were analysed using enzyme-linked immunosorbent assay. It was found that 20 µg/mL ES proteins of adult T. canis induced the expression of NOD1, RIP2 and NF-κB in mouse macrophages at both transcriptional and translational levels after 9 h of incubation in vitro. Incubation with 20 µg/mL ES proteins also modulated the production of pro-inflammatory cytokines TNF-ɑ, IL-1ß and IL-6 by the macrophages. Taken together, ES proteins of adult T. canis appeared to be able to affect the macrophage NOD1-RIP2-NF-κB signalling pathway, which might play a role in regulating the production of proinflammatory cytokines. Further investigation of these aspects should lead to a better understanding of immune recognition of and modulation by Toxocara canis in host animals.

[Investigation and research on ticks carrying spotted fever group rickettsia in the border area of Tumen River Basin].

Objective: To understand the situation and genotype distribution of spotted fever group rickettsia (SFGR) in the border area of Tumen River Basin in free ticks in Yanbian Korean Autonomous Prefecture (Yanbian Prefecture), Jilin Province. Methods: From April to September, 2017, ticks were collected using flagging method from Hunchun, Tumen, Helong and Longjing cities in the Tumen River basin of Yanbian Prefecture. Outer membrane protein A (ompA) was detected by Polymerase Chain Reaction (PCR), then, the species were identified by gene sequencing and analyzed systematically. The positive rate of pools and MIR(minimum infection rate per 100 ticks,MIR) of SFGR were calculated, and the difference of positive rate of pools among ticks with different characteristics was compared by Chi-square test. Results: A total of 3 079 ticks were collected and divided into 536 pools. The positive rate of pools of SFGR nucleic acid was 39.7% (213 pools). The MIR of SFGR was 6.9%.The positive rate of pools of SFGR in Dermacentor silvarum, Haemaphysalis concinna, Haemaphysalis japonica, Haemaphysalis longicornis and Ixodes persulcatus were 80.4% (41/51), 14.0% (25/179), 20.2% (18/89), 78.9% (101/128) and 25.9% (21/81), and the difference was statistically significant (P<0.001). There was statistical difference in the positive rate of pools of SFGR in developmental stages of ticks (P<0.001); the positive rate of pools of female adults, male adults, nymph and larvae were 36.4% (95/261), 34.2% (67/196), 56.3% (40/71) and 7/8, and the MIR was 7.9%, 7.7%, 4.9% and 3.5%. The five genotype was detected which was Candidatus Rickettsia longicornii, Rickettsia raoultii, Rickettsia heilongjiangensis, Candidatus Rickettsia tarasevichiae,Rickettsia monacensis and have 98%-100% homology with known gene sequences. Candidatus Rickettsia longicornii, Rickettsia raoultii, Rickettsia heilongjiangensis and Candidatus Rickettsia tarasevichiae showed close evolutionary relationship with known specie (have 98%-100% homology with known gene sequences); Rickettsia monacensis showed Far from evolutionary relationship with known species (have 98% homology with known gene sequences). Conclusion: SFGR infection of ticks is common in the border areas of the Tumen River Basin. There was high diversity in SFGR species and tick species in the areas surveyed.

Effects of isomaltooligosaccharide and Bacillus supplementation on sow performance, serum metabolites, and serum and placental oxidative status.

This study investigated the effects of isomaltooligosaccharide (IMO) and Bacillus supplementation on sow performance, serum metabolites, and serum and placental oxidative status. Multiparous gestating sows (n = 130) with similar body conditions were randomly allocated to five groups (n = 26) receiving a basal diet (CON group) or a basal diet supplemented with 0.5% IMO (IMO group); 0.5% IMO and 0.02% Bacillus subtilis (IMO + S group); 0.5% IMO and 0.02% Bacillus licheniformis (IMO + L group); or 0.5% IMO, 0.02% Bacillus subtilis, and 0.02% Bacillus licheniformis (IMO + S+L group). There were no significant differences in the litter sizes among all dietary groups. The average piglet birth weight was improved in all treatment groups, and the placental efficiency was greater in the IMO + S and IMO + S+L groups than in the CON group (P < 0.05). The IMO + S+L group had increased the low-density lipoprotein cholesterol and reduced the total cholesterol in umbilical venous serum (P <  0.05). Additionally, the malondialdehyde concentrations were greater in umbilical venous serum of piglets in all treatment groups relative to that in the CON piglets (P <  0.05). The placental total antioxidant capacity was increased in the IMO+L and IMO+S+L groups (P <  0.05). Furthermore, the growth hormone concentration in umbilical venous serum was greater (P <  0.05) in all treatment groups. Overall, IMO and Bacillus supplementation during late gestation resulted in a changed metabolism of sows, improved the placental antioxidant capacity, and increased the growth hormone concentrations in umbilical venous serum, which ultimately improved the piglet birth weight and placental efficiency.

Construction of a recombinant baculovirus expressing swine hepatitis E Virus ORF2 and preliminary research on its immune effect.

In the swine hepatitis E virus (HEV), open reading frame 2 (ORF2) is rich in antigenic determinants and neutralizing epitopes that could induce immune protection. We chose the Bac-to-Bac® Baculovirus Expression System to express fragments containing the critical neutralizing antigenic sites within the HEV ORF2 protein of pigs to obtain a recombinant baculovirus. The fragment of swine HEV ORF2 region (1198-1881bp) was cloned into vector pFastBacTM. A recombinant baculovirus, rBacmid-ORF2, was obtained after transposition and transfection. The molecular mass of the recombinant protein was 26 kDa. Mice were immunized by the intraperitoneal and oral routes with cell lysates of recombinant baculovirus rBacmid-ORF2. Serum and feces of the mice were collected separately at 0, 14, 28, and 42 d after immunization and the antibody levels of IgG and secretory IgA against swine HEV were determined using an enzyme-linked immunosorbent assay. The results suggested that rBacmid-ORF2 induced antibodies of the humoral and mucosal immune responses in mice and that the oral route was significantly superior to the intraperitoneal route. This is the first study to demonstrate that that recombinant baculovirus swine HEV ORF2 could induce humoral and mucosal immune responses in mice.

Effects of dietary supplementation with enzymatically treated Artemisia annua on growth performance, intestinal morphology, digestive enzyme activities, immunity, and antioxidant capacity of heat-stressed broilers.

The gastrointestinal tract is considered as one of the main target organs affected by heat stress. Phytogenic feed additives containing phenolics and flavonoids can improve the resistance of broilers to heat stress. This study was conducted to investigate the effects of dietary supplementation with enzymatically treated Artemisia annua (EA) on growth performance, intestinal morphology, digestive enzyme activities, immunity and antioxidant capacity of broilers challenged with heat stress. One hundred and forty-four 21-day-old male Arbor Acres broilers were randomly distributed into 3 treatments: 1) non-challenged control (CON); 2) heat-stress-challenged control (HS); and 3) heat-stress-challenged group + 1 g EA/kg diet (HS-EA). From 22 to 41 d, broilers in the CON group were housed at 22 ± 1°C, the HS and HS-EA groups, in which broilers were raised at 34 ± 1°C for 8 h (0900-1700 h) and the temperature for the rest time was the same as that of the CON group. The EA supplementation alleviated the compromised body weight gain and intestinal morphology impairment caused by heat stress challenge (P < 0.05). The EA attenuated heat-stress-induced decreased intestinal lipase, trypsin and total superoxide dismutase activities, and reduced intestinal secretory immunoglobulin A (SIgA) and IgG concentrations (P < 0.05). The EA inclusion prevented the elevation of intestinal malondialdehyde content and reduction of intestinal glutathione concentration induced by heat stress challenge (P < 0.05). The intestinal mRNA abundances of nuclear factor erythroid 2-related factor 2, heme oxygenase 1, glutathione peroxidase, gamma-glutamyl cysteine ligase larger catalytic subunit and gamma-glutamyl cysteine ligase smaller modulator subunit in heat-stressed broilers were increased in response to dietary EA treatment (P < 0.05). In conclusion, dietary supplementation of 1 g/kg EA could alleviate heat-stress-induced compromised growth performance and intestinal damage of broilers.

Effects of dietary vitamin E type on the growth performance and antioxidant capacity in cyclophosphamide immunosuppressed broilers.

Reactive oxygen species and free radicals play multiple roles in some immune-pathological events. Vitamin E, as a very potent antioxidant, perhaps deceases the potentially negative effects of such oxidative stress to prevent immune-pathological damage to broilers. Therefore, the current study investigated the effects of dietary natural (D-α-tocopherol) and synthetic (DL-α-tocopherol acetate) vitamin E on the growth performance and antioxidant capacity in cyclophosphamide (CY) immunosuppressed broilers. 192 one-day-old male Arbor Acre broilers were randomly distributed into 4 groups: 1) non-CY-challenged control; 2) CY-challenged control; 3) CY-challenged group+20 IU DL-α-tocopherol acetate per kg feed; and 4) CY-challenged group+20 IU D-α-tocopherol per kg feed. The maize-soybean basal diet in the control group contained α-tocopherol (7.12 mg/kg). Broilers were intramuscularly injected with 80 mg/kg body weight of CY or sterile saline at 16, 17, and 18 d of age. CY decreased (P < 0.05) the average daily gain and average daily feed intake, but vitamin E did not alter the growth performance of broilers before or after CY injection (P > 0.05). The decreased absolute weight of the spleen, thymus and bursa, serum interleukin 2 (IL-2), and interleukin 6 (IL-2) concentrations in CY-treated broilers were alleviated by vitamin E (P < 0.05) . The decreased relative weight (g/kg body weight) of the bursa in the CY-treated broilers was increased by natural vitamin E (P < 0.05). The CY-induced increases in malondialdehyde (MDA) content and decreases in total antioxidant capacity (T-AOC), glutathione, vitamin C, and α-tocopherol levels, and total superoxide dismutase and glutathione peroxidase activities in both serum and the liver were attenuated by vitamin E (P < 0.05). Additionally, natural vitamin E increased α-tocopherol and T-AOC levels and decreased MDA content in the liver of CY-treated broilers (P < 0.05) when compared to the synthetic form. In summary, both synthetic and natural vitamin E supplementation improved lymphoid organ weights, serum IL-2 and IL-6 levels, and antioxidant capacity of immunosuppressed broilers induced by CY. Especially, natural vitamin E was superior to the synthetic form and enhanced α-tocopherol and T-AOC levels, reduced MDA concentration in the liver, and alleviated the immune damage of the bursa.

Evaluation of enzymatically treated Artemisia annua L. on growth performance, meat quality, and oxidative stability of breast and thigh muscles in broilers.

An experiment was conducted to evaluate the effects of including enzymatically treated Artemisia annua L. (EA) in broiler diets on growth performance, meat quality, and oxidative stability of breast and thigh muscles. A total of 256 one-d-old Arbor Acres broiler chicks were randomly allotted into four groups with eight replicates of eight birds each. Broilers in the four groups were offered basal diet supplemented with 0.0, 0.5, 1.0, and 1.5 g/kg EA during the 42-d experiment, respectively. The ADG, ADFI, and feed/gain ratio (F:G) were measured at 42 d of age. Breast and thigh muscle samples from eight birds per treatment were obtained at 42 d to determine meat quality, free radical scavenging activity, and lipid peroxidation. All treatment groups had similar ADG, ADFI, and F:G during the 42 d experiment (P > 0.05). Drip loss at 24 h and shearing force of breast muscle were linearly (P < 0.05) and quadratically (P < 0.05) decreased by EA addition. The drip loss at 24 h and 48 h, cooking loss and shearing force of thigh muscle followed the same fashion. The supplementation of EA quadratically increased 2, 2-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) (P = 0.004) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) (P = 0.035) free radical scavenging activities in breast muscle, and linearly (P < 0.05) and quadratically (P < 0.05) increased ABTS and DPPH scavenging activities of thigh muscle. Increasing levels of EA linearly (P < 0.05) or quadratically (P < 0.05) or both decreased the malondialdehyde (MDA) concentrations in breast and thigh muscle samples during 15 d of storage at 4°C. The results indicated that EA supplementation improved meat quality and oxidative stability of breast and thigh muscles in broilers. The inclusion level of 1.0 g/kg EA in broiler diet was recommended.

Effects of Oridonin on growth performance and oxidative stress in broilers challenged with lipopolysaccharide.

This study was conducted to investigate the effects of oridonin (ORI) on growth performance and antioxidant capacity in broiler chickens that were repeatedly challenged with lipopolysaccharide (LPS). A total of 384 one-day-old male Arbor Acre broiler chickens were randomly assigned to 8 treatments with 6 replicate cages per treatment and 8 birds per replicate. There were 4 dietary treatments: the control group (birds fed the basal diet), the ORI 50 group, the ORI 80 group, and the ORI 100 group (the basal diet supplemented with 50, 80, and 100 mg/kg oridonin, respectively). Broilers were intraperitoneally injected with either 250 µg/kg BW LPS or an equivalent amount of sterile saline at 16, 18, and 20 d of age. LPS decreased the average daily weight gain (ADG), the average daily feed intake (ADFI), and the feed conversion ratio (FCR) of broiler chickens (P < 0.05); oridonin supplementation had no effects on performance whether before or after LPS injection (P > 0.05). LPS stimulation increased the relative weight of the spleen and bursa (P < 0.05); oridonin inclusion markedly attenuated the increased spleen index (P < 0.05). Additionally, the LPS-induced increases in the concentrations of malondialdehyde (MDA) and decreases in activities of total superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC) and catalase (CAT) were dramatically attenuated by oridonin in both the serum and liver (P < 0.05). Furthermore, LPS down-regulated the mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), copper and zinc superoxide dismutase (Cu/Zn-SOD), manganese superoxide dismutase (Mn-SOD), glutathione peroxidase (GPx1), and CAT in the liver (P < 0.05), However, oridonin inclusion increased the liver mRNA expression levels of Nrf2, Cu/Zn-SOD, Mn-SOD, CAT, and GPx1 (P < 0.05). It was concluded that the dietary oridonin supplementation at an optimum dose of 100 mg/kg improves the antioxidant capacity in broilers, as evidenced by the decrease in MDA and the increase in total SOD activities and mRNA expression levels of the liver antioxidant genes, although the effects on growth performance was negligible.

Effects of cello-oligosaccharide on intestinal microbiota and epithelial barrier function of weanling pigs.

A total of 144 piglets (Duroc × Landrace × Yorkshire; average initial weight of 6.13 kg weaned at 21 ± 1 d age) were allotted to 4 treatments for 2 wk, each of which had 6 pens with 6 pigs per pen. After the feeding experiment, 6 pigs per treatment were slaughtered to investigate the effects of cello-oligosaccharide (COS) on intestinal microbiota and epithelial barrier function. The COS was added to the basal diet at 0, 1.5, 3.0, and 4.5 g/kg diet at the expense of corn, respectively. Plasma -lactate, diamine oxidase (DAO), and the Ussing chamber technique were used to determine the intestinal barrier function. 16S rRNA-based methods were used for intestinal microbiota analysis. The results showed that incremental levels of COS had no effect ( > 0.05) on growth performance. Incremental levels of COS increased lactobacilli in jejunal and colonic contents ( < 0.05); decreased in jejunal contents ( < 0.05) and and in colonic contents ( < 0.05); reduced plasma DAO (linear, = 0.013, and quadratic, = 0.037); increased jejunal mucosa DAO (linear, = 0.003, and quadratic, = 0.008); decreased fluorescein isothiocyanate dextran 4 kDa flux of jejunum and colon ( < 0.05); and increased transepithelial electrical resistance (TER) in colon ( < 0.05), claudin-1 protein expression in jejunal mucosa (linear, = 0.001, and quadratic, = 0.003), and protein expressions of claudin-1 and zonula occludens-1 (ZO-1) in colonic mucosa linearly ( = 0.001 and = 0.001, respectively) and quadratically ( = 0.001 and = 0.002, respectively). The results indicated that the improved microbial ecosystem in the presence of COS might contribute to improvement in intestinal barrier function and tight junction proteins. Results also showed that the appropriate dietary COS supplementation level was 3.0 g/kg in weaned pig diets under our trial conditions.

Diosmectite-zinc oxide composite improves intestinal barrier restoration and modulates TGF-ß1, ERK1/2, and Akt in piglets after acetic acid challenge.

The present study evaluated the beneficial effect of diosmectite-zinc oxide composite (DS-ZnO) on improving intestinal barrier restoration in piglets after acetic acid challenge and explored the underlying mechanisms. Twenty-four 35-d-old piglets (Duroc × Landrace × Yorkshire), with an average weight of 8.1 kg, were allocated to 4 treatment groups. On d 1 of the trial, colitis was induced via intrarectal injection of acetic acid (10 mL of 10% acetic acid [ACA] solution for ACA, DS-ZnO, and mixture of diosmectite [DS] and ZnO [DS+ZnO] groups) and the control group was infused with saline. Twenty-four hours after challenged, piglets were fed with the following diets: 1) control group (basal diet), 2) ACA group (basal diet), 3) DS-ZnO group (basal diet supplemented with DS-ZnO), and 4) DS+ZnO group (mixture of 1.5 g diosmectite [DS]/kg and 500 mg Zn/kg from ZnO [equal amount of DS and ZnO in the DS-ZnO treatment group]). On d 8 of the trial, piglets were sacrificed. The results showed that DS-ZnO supplementation improved (P < 0.05) ADG, ADFI, and transepithelial electrical resistance and decreased (P < 0.05) fecal scores, crypt depth, and fluorescein isothiocyanate-dextran 4 kDa (FD4) influx as compared with ACA group. Moreover, DS-ZnO increased (P < 0.05) occludin, claudin-1, and zonula occluden-1 expressions; reduced (P < 0.05) caspase-9 and caspase-3 activity and Bax expression; and improved (P < 0.05) Bcl2, XIAP, and PCNA expression. Diosmectite-zinc oxide composite supplementation also increased (P < 0.05) TGF-ß1 expression and ERK1/2 and Akt activation. These results suggest that DS-ZnO attenuates the acetic acid-induced colitis by improving mucosa barrier restoration, inhibiting apoptosis, and improving intestinal epithelial cells proliferation and modulation of TGF-ß1 and ERK1/2 and Akt signaling pathway.

Germ cell-specific Atg7 knockout results in primary ovarian insufficiency in female mice.

Primary ovarian insufficiency (POI) is a common cause of infertility in around 1-2% of women aged <40 years. However, the mechanisms that cause POI are still poorly understood. Here we showed that germ cell-specific knockout of an essential autophagy induction gene Atg7 led to subfertility in female mice. The subfertility of Atg7 deletion females was caused by severe ovarian follicle loss, which is very similar to human POI patients. Further investigation revealed that germ cell-specific Atg7 knockout resulted in germ cell over-loss at the neonatal transition period. In addition, our in vitro studies also demonstrated that autophagy could protect oocytes from over-loss by apoptosis in neonatal ovaries under the starvation condition. Taken together, our results uncover a new role for autophagy in the regulation of ovarian primordial follicle reservation and hint that autophagy-related genes might be potential pathogenic genes to POI of women.

IFN-γ induces aberrant CD49b⁺ NK cell recruitment through regulating CX3CL1: a novel mechanism by which IFN-γ provokes pregnancy failure.

Interferon-γ (IFN-γ), a pleiotropic lymphokine, has important regulatory effects on many cell types. Although IFN-γ is essential for the initiation of uterine vascular modifications and maintenance of decidual integrity, IFN-γ administration can also cause pregnancy failure in many species. However, little is known about the effector mechanisms involved. In this study, using an IFN-γ-induced abortion mouse model, we reported that no Dolichos biflorus agglutinin lectin-positive uterine natural killer (uNK) cells were observed in the uteri from IFN-γ-induced abortion mice. By contrast, the percentage of CD3(-)CD49b(+) NK cells in the uterus and blood from a foetal resorption group was significantly higher than that of the control group. Similarly, significantly upregulated expression of CD49b (a pan-NK cell marker), CX3CL1 and CX3CR1 (CX3CL1 receptor) was detected in the uteri of IFN-γ-induced abortion mice. Using isolated uterine stromal cells, we showed that upregulated expression of CX3CL1 by IFN-γ was dependent on a Janus family kinase 2-signal transducers and activators of transcription 1 (JAK2-STAT1) pathway. We further demonstrated the chemotactic activity of CX3CL1 in uterine stromal cell conditioned medium on primary splenic NK cells. Finally, we observed increased recruitment of CD49b(+) NK cells into the endometrium after exogenous CX3CL1 administration. Collectively, our findings indicate that IFN-γ can significantly increase uterine CX3CL1 expression via activation of the JAK2-STAT1 pathway, thus inducing CD49b(+) NK cell uterine homing, and eventually provoke foetal loss. Thus, we provide a new line of evidence correlating the deleterious effects of IFN-γ on pregnancy with the aberrant regulation of CX3CL1 and CD49b(+) NK cells.

Anti-tumor activity and immunogenicity of a mutated staphylococcal enterotoxin C2.

In this study, a novel SEC2 mutant with lower toxic activity, named 2M-118 (H118A/T20L/G22E), was engineered by site-directed mutagenesis of structural domains that are responsible for MHC class II molecule binding and TCR binding, respectively. Stimulating activity on murine splenocytes, anti-tumor effect and immunogenicity of 2M-118 were investigated in BALB/c mice. 2M-118 not only remained splenocyte stimulation activity, but also effectively inhibited the growth of S180 sarcoma in the BALB/c mice. Even though antibodies to 2M-118 could be induced after repeated administration, the action of 2M-118 was hardly neutralized or cross neutralized. Like other superantigens, immunosuppression could happen when 2M-118 was given at a greater dose. In conclusion, 2M-118 is a promising anti-tumor drug candidate for its acceptable toxicity and satisfying anti-tumour efficacy.

[Determination of phenobarbital in human urine and serum using flow injection chemiluminescence].

A sensitive chemiluminescence method, based on the enhancive effect of phenobarbital on the chemiluminescence reaction between luminol and dissolved oxygen in a flow injection system, was proposed for the determination of phenobarbital. The chemiluminescence intensity responded to the concentration of phenobarbital linearly ranging from 0.05 to 10 ng x ml(-1) with the detection limit of 0.02 ng x ml(-1) (3 sigma). At a flow rate of 2.0 ml x min(-1), a complete determination of phenobarbital, including sampling and washing, could be accomplished in 0.5 min, offering the sampling efficiency of 120 h(-1) accordingly. The method was applied successfully in an assay of PB for pharmaceutical preparations, human urine and serum without any pretreatment with recovery from 95.7 to 106.7% and RSDs of less than 3.0%.

Premeiotic fetal murine germ cells cultured in vitro form typical oocyte-like cells but do not progress through meiosis.

A convenient method for fetal murine premeiotic germ cells to develop into oocytes in vitro has been established. Fetal ovaries from mice, collected 12.5 d postcoitus (dpc), were organ-cultured in vitro using a medium for organ growth, and the developmental potential regarding oocyte formation was determined. After 28 d of culture, premeiotic female germ cells developed into oocytes with a mean (+/-SD) diameter of 73.3+/-7.7 microm. However, follicles developed in vitro versus in vivo had fewer granulosa cells (32+/-2.6 vs. 142+/-9.5, respectively; P<0.01), and the ovaries had less mRNA for Cx37 and Cx43 (P<0.01). Oocytes in the first meiotic division phase were isolated from cultured ovaries or after hormone treatments. After exposure to okadaic acid at a final concentration of 1 microM, oocytes derived from premeiotic fetal female germ cells were able to undergo germinal vesicle breakdown but failed to complete the first meiotic division. Furthermore, the intracellular content of GSH in oocytes cultured in vitro was lower than that of oocytes matured in vivo (P<0.01). In conclusion, premeiotic germ cells derived from murine fetuses as early as 12.5 dpc were able to differentiate into germinal vesicle-stage oocytes but were unable to complete meiosis I in vitro.

Effects of pentachlorophenol on Galba pervia, Tubifex sinicus and Chironomus plumousus larvae.

The 24-h median lethal concentrations of pentachlorophenol to Chironomus plumousus, Tubifex sinicus and Galba pervia were 0.302, 0.977 and 0.293 mg/L, respectively. Bioconcentration factors of C. plumousus, T. sinicus and G. pervia to pentachlorophenol were 108, 367 and 85 at 0.02 mg/L pentachlorophenol, respectively. As pentachlorophenol concentration increased, the G. pervia egg hatching rates became lower, and the total hatched time became longer. Pentachlorophenol teratogenesis was demonstrated by observing the deformation of C. plumousus larvae mentum.

Chemical constituents of Cistanche sinensis.

One new phenylethanoid glycoside, cistansinenside A and one new oligosaccharide, cistansinensose A1/A2, were isolated from the stems of Cistanche sinensis, together with six known compounds. The structures of the new compounds were elucidated on the basis of spectral data.