Bath immunisation of spawn,fry and fingerlings of Indian major carps using a particulate bacterial antigen

Larval mortality in Indian major carps is one of the major problems encountered in the pond culture system. The present investigation was carried out to investigate the proper age, duration of exposure, and optimum bacterin concentration for vaccinating rohu (Labeo rohita) and catla (Catla catla) at their early stages with a formalin killed Edwardsiella tarda bacterin suspension. The development of immunological competence was recorded with spawn of rohu and catla of 3 weeks of age exposed to a bacterin at a concentration 10(9) cfu ml(-1) for 15 min, where it persisted up to 4 weeks post vaccination. They showed significant resistance against challenge with virulent E. tarda bacteria. Significant antibody titre could be recorded in advanced fries and fingerlings exposed to 10(9) cfu/ml(-1) bacterin concentration for 45 and 60 min, respectively.     

Neutrophil depletion does not prevent lung edema after endotoxin infusion in goats

Neutropenia was produced in goats by injection of either nitrogen mustard, (1.5 mg/kg) or hydroxyurea (200 mg X kg-1 X day-1). A nitrogen mustard (M + E) group (n = 6), a hydroxyurea (H + E) group (n = 5), and a control (E) group (n = 7) were given 1-h infusions of endotoxin (5 micrograms/kg total dose), then monitored for up to 5 h. Postmortem extravascular lung water (EVLW) was significantly higher in the M + E group (14.2 +/- 4.4 ml/kg) and the E group (11.9 +/- 3.9 ml/kg) when compared with a normal control (6.6 +/- 1.3 ml/kg) group that did not receive endotoxin. EVLW in a group made neutropenic with nitrogen mustard (6.7 +/- 1.3 ml/kg) and the H + E (7.9 +/- 1.5 ml/kg) groups were not statistically different from each other or from normal controls. Circulating neutrophil counts averaged 32 +/- 42 cells/microliter in the M + E group and 180 +/- 210 cells/microliter in the H + E group. Only minimal histological changes were seen in the H + E group, but the E and M + E lungs had severe pulmonary edema. We conclude that neutrophils are not required for increased EVLW and decreased arterial O2 partial pressure after endotoxin infusion, and hydroxyurea prevents at least part of the pulmonary edema after endotoxin by a mechanism that is not neutrophil dependent.     

Absorption of Escherichia coli endotoxin (lipopolysaccharide) from the uteri of postpartum dairy cows

An experiment was conducted to test the hypothesis that Escherichia coli (E. coli ) endotoxin is readily absorbed from uteri of early postpartum cows and that the absorbed endotoxin provokes systemic relcase of prostaglandins. Eleven postpartum Holstein dairy cows (aged 3 to 7 yr) with normal puerperium were selected and divided into a treatment group (n=7), which received intrauterine infusions of E. coli endotoxin, and a control group (n=4), which received intrauterine infusions of 10 ml of saline on Days 5 and 20 post partum. Blood samples were collected once every 30 min for 6 h starting from the time of infusion. Harvested sera samples were analyzed for concentrations of stable metabolites of prostacyclin (PCM), prostaglandin F(2alpha) (PGFM), and thromboxane A(2) (TXB(2)). Plasma samples were qualitatively tested for the presence of endotoxin. Endotoxin was detected in the plasma samples of cows that received endotoxin on Day 5 post partum 4 h after the infusion. Endotoxin was not detected in any of the samples from control cows on Days 5 and 20 post partum or from treatment group cows on Day 20 post partum. Cows treated on Day 5 post partum showed increases in serum PGFM concentrations from 710 +/-64pg/ml to peak concentrations of 1223 +/- 47 pg/ml within 2 h, followed by a decline to baseline concentrations within 4 h. The amount of PGFM released in treated cows on Day 5 post partum was higher (P < 0.05) than in control cows on Day 5 or in treated and control cows on Day 20 post partum. Serum PCM concentrations increased from 156+/-24 pg/ml to peak concentrations of 1348+/-127 pg/ml within 1 h. The amount of PCM released in treated cows on Day 5 postpartum was higher (P< 0.05) than in control cows on Day 5 or in treated and control cows on Day 20 post partum. The TXB(2) concentrations increased from 315+/-38 pg/ml to peak concentrations of 5043 +/- 242 pg/ml within 1 h and fell to baseline concentrations within 5 h. The amount of TXB(2) concentrations released in treated cows on Day 5 post partum was significant (P < 0.05) compared with those of cows in the other groups. The results support the hypothesis that uteri of early postpartum cows are capable of absorbing endotoxin, and the absorbed endotoxin provokes changes in the serum concentrations of prostanoids.     

Evaluation of thyrotropin releasing hormone as a therapeutic intervention for endotoxemia

Thyrotropin releasing hormone (TRH) has been reported to reduce endotoxin-induced hypotension and mortality rate in conscious rats. Limited data are available to explain these effects. We evaluated hemodynamic parameters, metabolic function, tissue injury, and survival rate in three groups of instrumented conscious rats following intravenous endotoxin (20 mg/kg, LD/90-24 h) challenge. Pretreatment with TRH (2.0 mg/kg, i.v.) was administered 10 min before endotoxin (n = 10) and control (n = 10) animals were given an equivalent volume of saline. The post-treated group (n = 7) was given TRH at the nadir of the hypotensive response following endotoxin to duplicate published protocols. 5 min after endotoxin blood pressure and cardiac output were significantly higher in the post and pre-treatment groups, respectively, compared to the untreated group. There were no differences at other times. Systemic vascular resistance was not affected by either treatment mode at any time. TRH treatment following endotoxin resulted in transient increases in heart and respiration rates and decreased central venous pressure during the first 30 min. Metabolic function indicated by measurements of glucose, lactate, hematocrit, pH, PO2, and PCO2 at 60 and 240 min after endotoxin was not modified by TRH. The hemorrhagic small intestine characteristic of this model was not improved by either treatment mode. Mortality rates at 4 h after endotoxin were 20% for the untreated, 40% for the pre-treated, and 43% for the post-treated. These results suggest TRH exerts early transient effects on cardiovascular responses evoked by endotoxin in the conscious rat but no lasting beneficial effects were found to support the use of TRH as a mono-therapy for endotoxemia.     

Effect of a new synthetic free radical scavenger, 2-octadecyl ascorbic acid, on the mortality in mouse endotoxemia

Oxygen-derived free radicals have been implicated as mediators of cellular injury in several model systems. In order to clarify the role of oxygen radicals in endotoxemia, we measured the serial lipid peroxide changes resulting from systemic radical reactions using a newly developed colormetric method. To determine the effect of a free radical scavenger on mortality in endotoxemia, a new synthetic scavenger, 2-Octadecylascorbic acid (CV-3611), which overcome the detrimental properties (circulation half-life and cell penetration) of native SOD, was used in the model of mouse endotoxemia induced by the i.p. administration of E-coli endotoxin (10 mg/kg). Serial LPO (Lipid Peroxide) changes revealed significant elevations from the basal level of 4.52 +/- 0.79 nmol/ml to 10.5 +/- 2.04 nmol/ml at 2h (P less than 0.05), 12.0 +/- 2.44 nmol/ml at 8h (P less than 0.05), 32.8 +/- 12.5 nmol/ml at 12h (P less than 0.05) and 13.6 +/- 2.40 nmol/ml at 24h (P less than 0.05) following i.p. administration of E-coli. The circulation half life of CV-3611 was checked by a reversed-phase HPLC after 10 mg/kg s.c. administration. The level of CV-3611 reached peak levels of 0.54 +/- 0.10 micrograms/ml at 1h and 0.52 +/- 0.20 micrograms/ml at 2h then gradually decreased to the level of 0.04 +/- 0.004 micrograms/ml at 6h and to a non-detectable level at 24h after s.c. administration. Increased survival was seen at 2 days (P less than 0.001) after E-coli endotoxin administration in the CV-3611 treated group compared to the control group. These results suggest that oxygen derived free radicals contribute to mortality in mouse endotoxemia and that antioxidants such as CV-3611 may provide a new therapeutic avenue by improving survival of patients with gram-negative bacterial sepsis.     

Immunological parameters of Javanese carp Puntius gonionotus (Bleeker) exposed to copper and challenged with Aeromonas hydrophila.

This study was to determine the median lethal concentration (LC50) of copper to Javenese carp, Puntius gonionotus (Bleeker), and the immune response after the fish were exposed to sublethal levels of copper and challenged with formalin killed Aeromonas hydrophila. The LC50 of copper on P. gonionotus at 24, 48, 72, 96 and 120 h were estimated as 2.17, 0.91, 0.57, 0.53 and 0.42 mg l(-1), respectively. To determine the effect of copper on the immune system, fish were exposed for 66 days to 0.05, 0.10 and 0.15 mg Cu l(-1). After 56 days of initial exposure to copper, fish were challenged with 0.1 ml of 4.5 x 10(5) cfu ml(-1) formalin killed A. hydrophila and maintained in the same concentration of copper. After the challenge, the immune response was monitored for 2 weeks using haematological and serological assays. During the initial phase of exposure to copper, significant changes were noted in the white blood cell, lysozyme, potential killing activity, total plasma protein, total immunoglobulin and haematocrit levels between the control and treated fish. One week after challenge with A. hydrophila, there was a significant increase in the values of white blood cells, total protein and total immunoglobulin compared to the values before the challenge. However, these values were not significantly different (P>0.05) between the control and the treated fish. In contrast, NBT and lysozyme assays exhibited a significant difference (P<0.05) in fish exposed to 0.10 mg Cu l(-1) (0.525 +/- 0.17; 24.42 +/- 3.35 x 10(2) micromg ml(-1)) and 0.15 mg Cu 1(-1) (0.536 +/- 0.19; 21.78 +/- 1.29 x 10(2) micromg ml(-1)) compared to the control (0.746 +/- 0.31; 30.73 +/- 5.42 x 10(2) micromg ml(-1)) after the bacterial challenge (day 61). There was however no significant difference (P>0.05) in NBT and lysozyme levels in fish exposed to lower level of copper (0.05 mg Cu l(-1)), suggesting the absence of immunosuppressive effects at lower level of exposure.     

The immunomodulatory effects of tuftsin on the non-specific immune system of Indian Major carp, Labeo rohita

The purpose of this study was to determine if injections of different dosages of tuftsin would enhance the immune response and disease resistance against the infections due to the opportunistic pathogens Aeromonas hydrophila and Edwardsiella tarda in Labeo rohita fingerlings. Hence, four different dosages of tuftsin in PBS suspension at the rate of 0, 5, 10, 15 mg kg(-1) body weight of fish were injected intraperitoneally to the fingerlings of L. rohita at 2-week intervals for four times. After every 2-week interval, different serum biochemical, haematological and immunological parameters of fish were evaluated. Biochemical and haematological parameters including serum total protein content, albumin content, globulin content, albulin:globulin ratio, glucose content, leucocyte counts etc.; cellular immune parameters including superoxide anion production, phagocytic activities, lymphokine production index etc.; humoral immune parameters including lysozyme activity, complement activity, serum bactericidal activity etc., in the fish were evaluated after every 2-week interval. After 56 days, fish were divided into two subgroups under each major treatment group for challenge with two pathogens A. hydrophila and E. tarda. The mortality (%) and agglutinating antibody titre was recorded on 28th day post challenge. Most of the immune parameters including leucocyte count, phagocytic ratio, phagocytic index, lysozyme activity, complement activity, and serum bactericidal activity were significantly (p相似文献   

Endotoxin stimulates endothelin-release in vivo and in vitro as determined by radioimmunoassay

A marked increase in immunoreactive endothelin was observed in rat serum collected within 10-15 min after infusion of endotoxin. Endothelin level was 117 +/- 11.5 pg/ml (mean +/- S.E., N = 4) in rats exposed to endotoxin as compared with undetectable levels (less than 2 pg/ml, N = 4) in controls. We have also observed a significant stimulation of endothelin-release by endotoxin from cultured bovine transformed thoractic aortic endothelial cells at concentrations of endotoxin ranging between 0.1 and 10.0 micrograms/ml. Serum was indispensable for the stimulating effect of endotoxin, although serum itself did not show any effect at the concentration used (1%). These results suggest that endothelin plays an important role in mediation of pathophysiological responses caused by endotoxin. The levels of endothelin were measured by radioimmunoassay with high sensitivity.     

Fluid filtration coefficient of isolated goat lungs was unchanged by endotoxin

The Starling fluid filtration coefficient (Kf) of blood-perfused excised goat lungs was examined before and after infusion of Escherichia coli endotoxin. Kf was calculated from rate of weight gain as described by Drake et al. [Am. J. Physiol. 234 (Heart Circ. Physiol. 3): H266-H274, 1978]. These calculations were made twice during base line and then at hourly intervals for 5 h after infusion of 5 mg (approximately 250 micrograms/kg) of E. coli endotoxin or after injection of oleic acid (47 microliter/kg). All lungs were perfused at constant arterial and venous pressure under zone 3 conditions. Base-line Kf averaged 27 +/- 10 and 20 +/- 4 (SD) microliter.min-1.cmH2O-1.g dry wt-1 for endotoxin and oleic acid groups, respectively. It was unchanged in the endotoxin group throughout the experiment but approximately doubled in the oleic acid lungs. Pulmonary arterial and venous pressures were not changed significantly during the course of these experiments in either group. Lung wet-to-dry weight ratios of these lungs were 5.6 +/- 0.6 and 6.1 +/- 0.5 ml/g for the endotoxin and oleic acid groups, respectively. This compares with 4.6 +/- 0.5 ml/g for normal, freshly excised but not perfused goat lungs. The small change in lung water and unchanged pulmonary pressures after both endotoxin and oleic acid suggest that lung injury was minimal. We conclude that 1) endotoxin does not cause a direct injury to the endothelium of isolated lungs during the first 5 h of perfusion, and 2) neutrophils are not sufficient to cause increased Kf after endotoxin infusion in this preparation.     

Effect of multiple injections of beta-glucan on non-specific immune response and disease resistance in Labeo rohita fingerlings

The purpose of this study was to determine if multiple injections of different dosages of beta-glucan derived from barley would enhance the immune response and disease resistance against infections due to opportunistic pathogens Aeromonas hydrophila and Edwardsiella tarda in Labeo rohita fingerlings. Hence, four different dosages of beta-glucan suspension in phosphate-buffered saline at the rate of 0, 5, 10, 15 mg kg(-1) body weight of fish were injected intraperitoneally to the fingerlings of Labeo rohita at two-week intervals for four times. After every two-week interval different serum biochemical, haematological and immunological parameters of fish were evaluated. At the end of immunostimulation trial of 56 days, fish were divided into four subgroups under each major treatment group for challenge through i.p injection and bath immersion with two pathogens, A. hydrophila and E. tarda. The mortality (%) and agglutinating antibody titre was recoded on 28th day post challenge. Most of the immune parameters such as leucocyte count, phagocytic ratio, phagocytic index, lysozyme activity, complement activity, serum bactericidal activity were significantly (P < 0.05) enhanced on 42 days after three i.p injections of 10 mg of beta-glucan kg(-1) body wt. Challenge study indicated least mortality in the group of fishes injected with medium dose of 10 mg of beta-glucan kg(-1) body wt. four times. Multiple injections of beta-glucan might have maintained the activation of phagocytic cells for a long period which in turn would lead to long-term protection in fishes. Thus, injections of 10 mg of beta-glucan kg(-1) body wt. for three times can be advocated to enhance the immune response of fish species under aquaculture.     

Generation of two auxotrophic genes knock-out Edwardsiella tarda and assessment of its potential as a combined vaccine in olive flounder (Paralichthys olivaceus)

Two auxotrophic genes that play essential roles in bacterial cell wall biosynthesis--alanine racemase (alr) gene and aspartate semialdehyde dehydrogenase (asd) gene--knock-out Edwardsiella tarda (Δalr Δasd E. tarda) was generated by the allelic exchange method to develop a combined vaccine system. Green fluorescent protein (GFP) was used as a model foreign protein, and was expressed by transformation of the mutant E. tarda with antibiotic resistant gene-free plasmids harboring cassettes for GFP and asd expression (pG02-ASD-EtPR-GFP). In vitro growth of the mutant E. tarda was similar to wild-type E. tarda when D-alanine and diaminopimelic acid (DAP) were supplemented to growth medium. However, without d-alanine and/or DAP supplementation, the mutant showed very limited growth. The Δalr Δasd E. tarda transformed with pG02-ASD-EtPR-GFP showed a similar growth pattern of wild-type E. tarda when D-alanine was supplemented in the medium, and the expression of GFP could be observed even with naked eyes. The virulence of the auxotrophic mutant E. tarda was decreased, which was demonstrated by approximately 10? fold increase of LD?? dose compared to wild-type E. tarda. To assess vaccine potential of the present combined vaccine system, olive flounder (Paralichthys olivaceus) were immunized with the GFP expressing mutant E. tarda, and analyzed protection efficacy against E. tarda challenge and antibody titers against E. tarda and GFP. Groups of fish immunized with 10? CFU of the Δalr Δasd E. tarda harboring pG02-ASD-EtPR-GFP showed no mortality, which was irrespective to boost immunization. The cumulative mortality rates of fish immunized with 10? or 10? CFU of the mutant bacteria were lowered by a boost immunization. Fish immunized with the mutant E. tarda at doses of 10?-10? CFU/fish showed significantly higher serum agglutination activities against formalin-killed E. tarda than PBS-injected control fish. Furthermore, fish immunized with 10?-10? CFU/fish of the mutant E. tarda showed significantly higher ELISA titer against GFP antigen than fish in other groups. These results indicate that the present double auxotrophic genes knock-out E. tarda coupled with a heterologous antigen expression has a great strategic potential to be used as combined vaccines against various fish diseases.     

Molluscicidal action of the latex of Euphorbia splendens var. hislopii N.E.B. ("Christ's Crown") (Euphorbiaceae) against Lymnaea columella (Say, 1817) (Pulmonata: Lymnaeidae), intermediate host of Fasciola hepatica Linnaeus, 1758 (Trematode: Fasciolidae): 1- test in laboratory

The latex action of Euphorbia splendens var. hislopii (Christ's Crown) against snails Lymnaea columella, intermediate host of Fasciola hepatica, derived from irrigation ditches of the Station of Pisciculture at Universidade Federal Rural do Rio de Janeiro, was studied in the laboratory. Lab bioassays, using aqueous solutions of the latex, varying between 0.1 and 10 mg/l, have proven molluscicidal activity of the product collected on the same day the tests were performed, during the four seasons of the year, finding the following lethal concentrations (LC90): 1.51 mg/l in the spring; 0.55 mg/l in the summer; 0.74 mg/l in the fall and 0.93 mg/l in winter, after 24 h exposure of the snails, showing significant differences among the seasons of the year (ANOVA test, F = 11.01, G.L.= 3/33, p < 0.05), as well as among the concentrations (ANOVA test, F = 27.38, G.L.= 11/33, p < 0.05). In the summer, mortality reached 100% from concentration at 0.6 mg/l, the same during fall and in winter as of 1 mg/l, while in spring it only reached 100% mortality as of 2 mg/l. Mortality in the controls was low, reaching 5% in the summer and winter and 10% in the fall and spring. None of the samples died. During the assay, with an aqueous solution of the latex at a concentration of 5 mg/l, in order to check the time of duration of the product effect, in the laboratory, it was observed that the molluscicidal activity remained stable up to the 15th day after the beginning of the test with 100% mortality of L. columella, gradually losing its effect until the 23rd day, when we no longer observed animal mortality. In the control group, there was a random daily variation in mortality rate ranging 0-50% after 48 h of observation for 30 days.     

迟缓爱德华氏菌对Hep-2细胞的侵袭特性

用细胞裂解计数法及超薄切片电镜观察法分析了迟缓爱德华氏菌侵袭ＨＥｐ－２细胞的基本特性。在１５株来源各异的迟缓爱德华氏菌中,有６株细菌具有对ＨＥｐ－２细胞的侵袭能力。细菌侵入细胞后,主要位于空泡内。侵入细胞内的迟缓爱德华氏菌不仅可在细胞内增殖,而且可从细胞内释放出来。用细胞松弛素破坏微丝后可抑制其侵袭作用,而且表现出剂量依赖关系,而在秋水仙素破坏微管后不影响其侵袭力。这表明在迟缓爱德华氏菌对ＨＥｐ－     

Dexamethasone protects against high-dose endotoxin without loss of tolerance to oxygen

Endotoxin (500 micrograms/kg)-treated rats are very tolerant to hyperoxia (greater than 95% O2, 1 ATA). We have now attempted to determine if dexamethasone given to rats 1 h before a usually lethal dose of endotoxin would diminish endotoxin's lethality without substantially abrogating its capacity to confer tolerance to hyperoxia. Endotoxin (20 mg/kg) given alone killed 70-80% of air- or O2-breathing rats within 24 h; dexamethasone (0.6 mg) given 1 h before endotoxin decreased mortality at 24 h to 10-15%. About 90% of the rats that were alive 24 h after receiving dexamethasone plus endotoxin (20 mg/kg) survived 72 h of hyperoxia. Dexamethasone plus endotoxin (10 mg/kg) provided as much protection against pulmonary edema resulting from 72 h of hyperoxia as did 500 micrograms/kg endotoxin alone. Tolerance to hyperoxia produced by dexamethasone plus high-dose endotoxin was accompanied by a rise in the activity in the lung of antioxidant enzymes. We conclude that dexamethasone protects rats against the lethal effects of high doses of endotoxin without interfering with endotoxin's capacity to engender tolerance to hyperoxia.     

Evaluation of steroid microspheres for control of estrus in cows and induction of puberty in heifers

Two trials were designed to test whether a single treatment with a microsphere formulation of progesterone (P) could simulate the luteal phase of the estrous cycle and lead to estrus and subsequent luteal development. The first experiment was to characterize the pattern of serum P concentrations and estrus in cows treated with a microsphere formulation (P + E) that contained 625 mg P and 50 mg estradiol (E). Four cows with palpable corpora lutea were treated with 25 mg prostaglandin F2 m. Each cow was given P + E (i.m.) 12 h later. Tail vein blood samples were taken on Days 1 and 2 following P + E treatment and then three times weekly for 24 days. Serum P increased from 0.8 +/- 0.1 ng/ml at P + E treatment to 4.7 +/- 0.6 ng/ml on Day 1, declined gradually to 4.1 +/- 0.3 ng/ml on Day 7 and then declined more rapidly to 0.6 +/- 0.1 ng/ml on Day 13. Treated cows showed estrus 16.25 +/- 0.7 days after P + E treatment. Thereafter, serum P increased beginning on Day 20 after P + E treatment, as expected following estrus. In Experiment 2, Angus and Simmental heifers (10.5-11.5 months of age) were administered i.m. either the vehicle (controls), E (50 mg), P (625 mg) or P + E (n = 13 per group). While treatment with E resulted in behavioral estrus (1-2 days after treatment) in each treated heifer, it did not (P > 0.5) initiate estrous cycles as indicated by subsequent increased serum P. In contrast, the P and P + E treatments increased (P < 0.05) the proportion (11/13) of heifers that showed estrus by 21 days after treatment followed by elevated serum P. We conclude that the microsphere formulation of P simulated the pattern of serum P concentrations during the luteal phase of the estrous cycle and initiated estrous cycles in peripubertal heifers with or without E.     

Isolation,Culture and Callus Formation of lpomoea batatas Protoplasts

Numerous viable protoplasts from stem callus cells of Ipomoea batatas tissue culture have been isolated by enzyme treatment involving cellulase EA3 867 (2.0%), CaC12·2H2O (20 mM) and mineral constituent of medium A at pH5.4 in 0.8 M mannitol in 5 hours at 25±1℃. The protoplasts were cultured at a density of 1-2 × 105/ml in solid agar medium E supplemented with 2, 4-D (0.1mg/l) and kinetin (0.1 mg/l), or NAA (0.3 mg/l) and kinetin (0.1 mg/l) in petri dishes, and placed in a controlled growth cabinet maintained at 27 ℃, and illuminated with floureseent light. They regenerated new cell wails after 7 days of culture. The first cell division was observed after 10 days. Ceil division continued thereafter, and after 40 days of culture small white calli (size about 0.2–0.3 mm) were visible in the petri dishes small calli were inoculated in the same nutrients as the protoplasts culture media, but without mannitol. They developed into large calli.     

Site of action for endotoxin-induced cortisol release in the suppression of preovulatory luteinizing hormone surges

The study was conducted to identify the mechanisms of endotoxin/cortisol action in the suppression of preovulatory LH surges in heifers infused with Escherichia coli (E. coli ) endotoxin. The hypotheses tested were that 1) endotoxin stimulates the release of progesterone, possibly from the adrenal leading to the LH blockade; 2) cortisol released in response to endotoxin infusion blocks the synthesis of estradiol at the ovarian level, culminating in a failure of the LH surge. Eight Holstein heifers were given two injections of prostaglandin F(2alpha) (PG), 11 d apart, to synchronize estrus. Starting from 25 h after the second injection of PG (PG-2), the uterus of each heifer was infused either with 5 ml of pyrogen-free water (control, n = 3) or with E. coli endotoxin (5 mug/kg of body weight) in 5 ml of pyrogen-free water (treated, n = 5), once every 6 h for 10 treatments. Blood samples were obtained every 15 min for 1 h before infusion and again 2 h after each infusion, then hourly until 1 h before the next infusion. After the tenth infusion, blood was collected daily until estrus. Serum progesterone concentrations remained at baseline values (< 1 ng/ml) in control and treated heifers. The total amount of progesterone measured starting 24 to 84 h after PG-2 injection was not different between control and treated heifers (P 0.05). In the control heifers, serum estradiol concentrations remained basal (< 10 pg/ml) until 4 h before the LH surge. Serum estradiol concentrations increased to 20 +/- 5.6 pg/ml, 4 h before the LH surge in control heifers (LH surge occurred 60 to 66 h after the PG-2 injection). There were no changes in serum estradiol concentrations in treated heifers during the sampling period, and the concentrations remained < 10 pg/ml. The total amount of estradiol measured in control heifers was higher (P < 0.05) than in treated heifers. The results if this study suggest that increases in cortisol concentrations after the infusion of endotoxin might block the synthesis of estradiol at the ovarian level, resulting in the failure of a preovulatory LH surge to occur.     

氯胺酮对小鼠Ⅲ度烧伤死亡率和瘢痕形成的作用

目的观察氯胺酮对小鼠Ⅲ度烧伤死亡率和疤痕形成的作用,为临床应用提供实验依据。方法小鼠背部用95%酒精造成Ⅲ度火焰烧伤,烧伤面积7cm2,烧伤时间30s;氯胺酮用量10～20mg/kg,分别于烧伤后或烧伤前后腹腔注射,对照组注射等量生理盐水,通过烧伤小鼠早期死亡率和烧伤后期瘢痕面积观察其作用。结果 BALB/c和C57BL/6小鼠烧伤后立即、4h、24h腹腔注射氯胺酮20mg/kg,小鼠死亡率分别为42.8%和100%,与对照组无明显差别（P〉0.05）;C57BL/6小鼠烧伤前10min和烧伤后4h、24h注射氯胺酮10mg/kg,小鼠死亡率为100%,与对照组也无差别。烧伤时间减为20s,于烧伤烧伤后立即和24h注射氯胺酮20mg/kg,35d后测定瘢痕面积,治疗组明显小于对照组（P〈0.05）。结论氯胺酮无明显降低小鼠烧伤早期死亡率的效果,但有减少烧伤瘢痕面积的作用,可能与氯胺酮抗炎作用有关。     

Protective effect of herbal and probiotics enriched diet on haematological and immunity status of Oplegnathus fasciatus (Temminck & Schlegel) against Edwardsiella tarda

This study determines the effect of diet enriched with the herb Baical skullcap Scutellaria baicalensis, and/or probiotics Lactobacillus sakei BK19 in rock bream, Oplegnathus fasciatus (32 ± 3 g) against Edwardsiella tarda. The changes in haematological parameters, innate immune response, and disease resistance were investigated after 1, 3, and 6 weeks. The white blood cell count (WBC: 10(4) mm(-3)), red blood cell count (RBC: 10(6) mm(-3)), and haemoglobin (Hb: g dl(-1)) levels significant increased (P < 0.05) with mixed diet on 3rd and 6th week and probiotics enriched diet on 6th week. The haematocrit (Ht: %) level significantly increased (P < 0.05) when fed with mixed diet on weeks 1-6. Interestingly, in mixed diet group the lymphocytes (LYM), monocytes (MON), and neutrophils (NEU) significantly increased from week 1-6. The eosinophils (EOS) significantly increased in all the treated groups. In the probiotics or mixed diet groups the total protein (TP: g dl(-1)) increased significantly on weeks 3 and 6. The serum lysozyme activity significantly was enhanced in all the treated groups indicating an increase in the innate immunity level. Serum complement, antiprotease activities, reactive oxygen species (ROS) and reactive nitrogen species (RNS) production significantly increased from week 1-6 with mixed diet. The maximum protection against E. tarda was recorded in mixed diet group with a minimum cumulative mortality of 20% and a high relative percent survival (RPS) of 72.84. In the probiotics and herbal diet groups the cumulative mortality was 25% and 35% and RPS was 68.63 and 59.42, respectively. This study indicates that administration of probiotics or mixed diets can effectively minimize the mortality and restore the altered hematological parameters and enhancing the innate immunity in O. fasciatus against E. tarda.     

Dose-dependent effects of a pyridoquinazoline thromboxane synthetase inhibitor on arachidonic acid metabolites and hemodynamics during E. coli endotoxemia in anesthetized sheep

We investigated the effects of a new pyridoquinazoline thromboxane synthetase inhibitor infused before administering Escherichia Coli endotoxin into 18 anesthetized sheep with lung lymph fistulas. In normal sheep increasing plasma Ro 23-3423 concentrations were associated with increased plasma levels of 6-keto-PGF1 alpha, a reduced systemic vascular resistance (SVR, r = -0.80) and systemic arterial pressure (SAP, r = -0.92), the mean SAP falling from 80 to 50 mm Hg at the 20 and 30 mg/kg doses. Endotoxin infused into normal sheep caused transient pulmonary vasoconstriction associated with increased TxB2 and 6-keto-PGF1 alpha levels while vasoconstriction and TxB2 increase were significantly inhibited by pretreatment with Ro 23-3423 in a dose-dependent manner. When compared to controls, plasma and lymph levels of 6-keto-PGF1 alpha, PGF2 alpha and PGE2 after endotoxin infusion were increased several-fold by administering Ro 23-3423 up to plasma levels of 10 micrograms/ml. Doses over 30 mg/kg with blood levels above 10 micrograms/ml reduced plasma and lymph levels of 6-keto-PGF1 alpha, PGF2 alpha and PGE2, suggesting cyclooxygenase blockade at this dose. The peak 6-keto-PGF1 alpha levels at 60 min after endotoxin infusion in sheep with Ro-23-3423 levels below 10 micrograms/ml were associated with the greatest systemic hypotension due to a reduced SVR (r = -0.86). After endotoxin infusion the leukotrienes B4, C4, D4 and E4 in lung lymph were assayed by radioimmunoassay and high pressure liquid chromatography and remained at baseline values.