The effects of low dietary levels of DDT on breeding performance in hybrid mice

A combination of breeding experiments was used to study the effects of various levels of dietary DDT on the reproductive efficiency in mammals. The results of feeding B6D2F₁ hybrid mice 5, 10, or 20 ppm of DDT in the first breeding experiment showed an increase in litter size and number weaned over controls. Ten ppm of DDT caused increases over controls in the number born and alive on day 1 (P<0.05). DDT caused decreases in the weight of pups at 5 ppm on days 15 and 30 (P<0.05 and 0.01, respectively), at 10 ppm on day 15 (P<0.005), and at 20 ppm on day 30 (P<0.05).A second breeding experiment using 30, 60, or 120 ppm of DDT showed a general detrimental effect on reproduction. Thirty ppm DDT-fed animals produced fewer pups than controls (P<0.01) at days 1, 15, and 30, and the pups weighed less than controls at 30 days of age (P<0.05). DDT at 120 ppm resulted in fewer mice at birth and at 30 days of age (P<0.01) than control diet.The third, fourth, and fifth breeding experiments involved diets with 0, 5, 10, and 20 ppm of DDT and with the addition of a 40-ppm level in the third and fourth studies. The data showed larger litter sizes on days 1, 15, and 30 for DDT-fed animals.This investigation indicates that 5, 10, 20, or 40 ppm of DDT in the diet often results in larger litter sizes and more pups weaned than controls. Animals fed levels of 30, 60, or 120 ppm of DDT generally produced fewer offspring than did control animals. DDT-fed mice often weighed less before weaning than control pups.Although variable responses were found, it appears from these studies that environmental levels of DDT are not detrimental to the reproductive efficiency of mice and may under certain circumstances be beneficial.This work was supported in part by the Illinois Agricultural Experiment Station.     

Impact of enteral nutrition on intestinal bacterial translocation and mortality in burned mice

The aim of these experiments was to study the effect of early enteral nutrition with either standard or enriched (arginine, n-3 fatty acids, RNA) enteral formulas on translocation of bacteria from the gut and acute mortality rate following thermal injury. In the first experiment 60 Balb c mice were gavaged with 10(10)Escherichia coli and received a 20% burn injury. In 40 mice enteral nutrition (20 standard, 20 enriched) was started immediately after injury and stopped 36 h later. In the control group (n = 20) aliquotes of Ringer's solution was administered intragastrically. Mortality rate was observed for 10 days post-injury. In the second experiment 60 Balb c mice were gavaged with 10(10)E. coli labelled with biotin(111) Indium and then burned. In 40 mice enteral nutrition (20 standard, 20 enriched) was started immediately after burn. The control group (n = 20) received aliquotes of Ringer's solution. 4 h after injury all animals were sacrificed and liver, lungs, kidneys, spleen and systemic blood were harvested, and radionuclide counts were measured. No animal died after day 3 post-burn. The mortality rate was significantly lower at day 1 in the groups infused with both enteral solutions (15%) compared to controls (30%; p = 0.05). At day 3 the animals fed with the enriched diets showed a lower mortality (5%) versus the standard and control groups (10%). Bacterial translocation to the liver and lungs was significantly higher in Ringer's group than in both enterally fed groups. Early post-burn enteral nutrition reduces both translocation and acute mortality. Supplementation of the diets with specific nutrients appears to exert additional advantages on outcome.     

Effects of calorie-restriction on the course of Trypanosoma cruzi infection

The effect of moderately and severely caloriedeficient diets on the course of Trypanosoma cruzi inreceiving different daily amounts of laboratory chow and water ad libitum, were inoculated with 50 or 500 blood trypomastigotes (T). Onset of parasitemia was seen earlier in severely and moderately malnourished mice with respect to controls and survival time was significantly shorter for severely malnourished animals regardless of the infecting dose. All moderately malnourished animals died as well as control animals infected with 500 T, at different intervals, while 33% of those controls infected with 50 T survived the infection. All uninfected animals survived until sacrifice on day 50 after initiation of diet. Another set of animals, receiving 4 or 6 g/day/animal of laboratory chow, was infected with approximately 15 parasites per animal 2 weeks after initiation of diet to induce a chronic infection. Mice were sacrificed 4, 7, and 11 months post infection, and, delayed hypersensitivity (DTH), serum antibodies, spleen cells blastogenesis, and histopathology of several tissues were analyzed. Malnourished animals showed impaired DTH and lower circulating antibody levels as measured by ELISA. There was a significant correlation between pathological damage and degree of parasitemia reached during the acute phase of infection. Mitogenic response to Concanavalin A was not affected by the diet but increased as time progressed. These results show that severe caloric deficiencies significantly accelerate death due to infection when high doses of parasites are used. During chronic infection, moderate malnutrition impaired some aspects of the immune response, i.e., DTH and circulating IgG antibodies measured by ELISA, while mitogenic activity remained unchanged. Histopathological alterations were not dependent on the diet but correlated with the peak of parasitemia reached during the acute phase of the disease.     

The effect of 10 alpha-trifluoromethylhydroartemisinin on Plasmodium berghei infection and its toxicity in experimental animals

The antimalarial activity of 10 alpha-trifluoromethylhydroartemisinin (TFMHA) was compared to that of dihydroartemisinin (DHA) in the Plamodium berghei mouse model. Treatment with TFMHA in mice infected with a P. berghei chloroquine-sensitive strain at 25 mg/kg for 3, 5, and 7 d, or DHA at the same dose for 7 d showed the parasite was eliminated from the host within 2.6 d. The radical cure and survival rates of these mice up to 60 d after infection were 90-100%. In mice infected with the P. berghei chloroquine-resistant strain, TFMHA used at 25 mg/kg/day for 3, 5, or 7 d reduced parasitaemia within 2 d. The radical cure and survival rates of these animals up to 60 d after infection were 30, 60, and 90% for the 3 treatment durations respectively. In contrast, DHA only had an inhibitory effect on the growth of the parasite within the first few days of treatment and could not eliminate the parasite even after 7 d of treatment. There was a 100% relapse and all mice died within 28 d after infection. The acute toxicity of TFMHA as determined by the median lethal dose (LD50) in mice treated orally was 820 mg/kg. In rabbits, TFMHA given orally at 20 mg/kg once daily for 28 successive days had no effect on the bodyweight, haematological, biochemical, histopathological and electrocardiogram parameters. The results showed that TFMHA is an effective antimalarial drug with a low level of toxicity.     

Influence of antigenic forms and adjuvants on protection against a lethal infection of Aujeszky's disease virus

The influence of antigenic forms and adjuvant types on protection against a lethal infection of Aujeszky's disease virus (ADV) in mice was investigated. Antiviral IgG2a antibody response against particulate (inactivated ADV) and soluble antigen (ADV solubilized with deoxychorate-Na) in approximate order of extent was ISA70>QS-21>positively charged liposome>negatively charged liposome>weak negatively charged liposome>ISA25>lablabside F saponin>aluminum phosphate gel>non adjuvant. Particulate antigen induced higher IgG2a antibody production than soluble antigen. Particulate antigen combined with ISA70, ISA25 or positively charged liposome gave 100, 50 and 40% protection to mice, respectively. In contrast, soluble antigen plus ISA70 conferred 30% protection on mice. Immunogens using the other adjuvants gave 相似文献   

Infection of young adult mice with dengue virus type 2

Young adult female mice, five to six weeks old, were injected intraperitoneally with 2·5 × 10^6·3 LD₅₀ of dengue-2 virus, New Guinea C strain. The mice were killed on day 1, 2, 3, 4, 5, 6, 7, 10, 14, 21, 28 and 35 respectively. By means of the immunofluorescent antibody technique, viral antigen appeared as irregular granules in the reticuloendothelial cells of liver, lymph nodes and spleen of infected mice on the first day after inoculation and then diminished. From the fifth to sixth day of infection dengue antigen appeared again as homogeneous staining in the cytoplasm of single or groups of mononuclear cells in the lymphatic sinuses only. Later, by the third week of infection, dengue antigen could be seen in the mononuclear cells located in the marginal zone of lymphoid follicle of the spleen, the pattern of staining changing to bright spherical granules. At the same time, the deposition of immune complexes (composed of dengue antigen, mouse gamma and β1C globulin) could be seen in the renal glomeruli of infected mice.Serum antibody to dengue virus was found at low levels, being maximal on the 14th day after infection. Dengue virus was not isolated from the sera or from the infected organs. Granulomatous inflammation developed in lymph nodes and liver of mice infected with dengue virus and in mice inoculated with normal mouse brain suspension. Proliferative glomerular lesion was observed on day 14 after inoculation without definite abnormal urine findings.     

Melatonin induces changes to serum cytokines in mice infected with the Venezuelan equine encephalomyelitis virus

We determined the influence of melatonin (MLT) on the induction of interleukin (IL)-2, IL-1 beta, IL-4, tumour necrosis factor-alpha (TNF-alpha) and gamma interferon (IFN-gamma) on mice infected with the Venezuelan equine encephalomyelitis (VEE) virus. Levels of IFN-gamma in the MLT-treated group were significantly increased (P < 0.001) when compared with the control non-infected group from day 1 to 6 post-infection (p.i.), while in infected mice treated with 500 micrograms MLT/kg of bodyweight enhanced levels of IFN-gamma were evident from 4 to 6 days p.i. No differences were detected in the levels of IL-2 between the controls, the infected mice treated with MLT and the infected untreated group, from day 2 p.i. No changes in serum levels of IL-4 were detected. In infected mice treated with MLT, blood levels of IL-1 beta were elevated almost 10-fold from day 1 to day 6 p.i. when compared to the control, the infected and the non-infected MLT-treated mice (P < 0.001). A highly significant rise (P < 0.001) of TNF-alpha was found in infected mice treated with MLT, from day 1 to 6 p.i. when compared to the other groups. A significant rise (P < 0.001) was also evident in the infected non-MLT-treated group and a less pronounced rise in the non-infected mice treated with MLT when compared to controls. The blockade of IFN-gamma and TNF-alpha did not inhibit the protective effect of MLT but when IL-1 beta was neutralized, 100% of the infected mice died suggesting that IL-1 beta induced by MLT treatment is a target cytokine to generate an immune response against the viral infection.     

Effect of vitamin A deficiency on the immune response to epizootic diarrhoea of infant mice (EDIM) rotavirus infection in mice.

The effect of vitamin A deficiency on the immune response to epizootic diarrhoea of infant mice (EDIM) rotavirus was studied in mice. The virus was given by oral dosing or by intraperitoneal injection. For oral challenge, weanling mice were fed on either a control or vitamin A-deficient diet ad lib. or pair-fed the control diet to the intake of the vitamin A-deficient group. A fourth group was fed on the vitamin A-deficient diet ad lib. for 10 weeks and then refed the control diet for 2 weeks. On day 77, mice were each given 30 microliters EDIM rotavirus orally and the animals were killed and examined 1 week later. The delayed-type hypersensitivity (DTH) response to picryl chloride was measured as an index of cell-mediated immunity. For intraperitoneal challenge, weanling mice were fed on either the control diet or the vitamin A-deficient diet ad lib. or pair-fed the control diet to the intake of the vitamin A-deficient group. On day 77, mice were each injected intraperitoneally with 30 microliters EDIM rotavirus and 1 week later antibody production was measured. In both experiments the body-weight, liver and serum vitamin A levels of the vitamin A-deficient group were significantly lower than the control or pair-fed groups. Following oral dosing the serum antibody levels specific to rotavirus were statistically significantly lower in vitamin A-deficient animals than the control or pair-fed groups. Vitamin A-deficient mice also showed an impaired DTH response compared with the control and pair-fed animals. Animals refed vitamin A for a short period showed a partial restoration of the antibody response. Following intraperitoneal challenge no statistically significant changes were observed in the serum antibody levels between any of the dietary groups. It is concluded that vitamin A deficiency impaired antibody production when rotavirus was given orally. Vitamin A deficiency also impaired cell-mediated immunity.     

Hyperimmune bovine colostrum specific for recombinant Cryptosporidium parvum antigen confers partial protection against cryptosporidiosis in immunosuppressed adult mice.

Preparturient cows were immunized three times over a six-week period with recombinant plasmid DNA encoding the Cryptosporidium parvum CP15/60 antigen by injecting the DNA in the mammary gland. Serum was collected at each immunization and first colostrum was collected after parturition; all were assayed for Cryptosporidium-specific antibodies (Ab). A serological response to C. parvum sporozoite and oocyst antigen was detected in cows immunized with pCP15/60 plasmid DNA. Colostrum from these cows, unlike colostrum from normal controls, contained Ab specific for C. parvum sporozoites and oocysts as indicated by immunofluorescence Ab (IFA) staining. Colostrum was also tested for conferring passive immunity against C. parvum infection by oral administration to immunosuppressed adult inbred mice. Immune colostrum and control colostrum were administered to separate groups of dexamethasone (DEX)-treated adult C57BL/6NCr mice beginning 12 h before and at 12 h intervals for 3 days after oral C. parvum oocyst infection. Cryptosporidium development was assayed in ilea of immune- and control-colostrum-treated mice 96 h postinfection by semiquantitative PCR. Mice receiving immune colostrum showed partial protection (about 50% reduction) against intestinal C. parvum development compared to mice receiving control colostrum. This protection was evident at a challenge dose of 10(3) C. parvum oocysts per mouse; no differences were noted in parasite development between groups receiving immune or control colostrum and infected with 10(4) oocysts. This study showed that serum and colostrum Ab response to C. parvum can be elicited in preparturient cows by direct injection of recombinant pCP15/60 plasmid DNA and that passive protection against cryptosporidiosis can be obtained by treating immunosuppressed mice with immune colostrum before and after C. parvum infection.     

Detection of Trichinella spiralis Circulating Antigens in Serum of Experimentally Infected Mice by an IgY-mAb Sandwich ELISA

Abstract In this study, a sandwich enzyme-linked immunosorbent assay (ELISA) based on IgY (egg yolk immunoglobulin) and monoclonal antibody (mAb) against excretory-secretory (ES) antigens of Trichinella spiralis muscle larvae was developed for detection of circulating antigens (CAg) in serum from mice infected with T. spiralis. The IgY-mAb sandwich ELISA involved the use of chicken antibody IgY as a capture antibody and mouse mAb 35B9 as a detecting antibody. This method was able to detect as little as 1?ng/mL of ES antigens added to normal mouse serum. A group of 15 mice was orally inoculated with 500 T. spiralis muscle larvae per animal and the serum samples were daily taken during 1-49 days post-infection (dpi). The level of CAg was detectable as early as 3 dpi in the sera from infected mice, increased gradually, and reached two peaks with detection rate of 40% at 13 dpi and 100% at 24 dpi, respectively. The anti-Trichinella antibodies was first detected in 33.3% of the infected mice at 3 week post-infection (wpi), and reached a peak positive rate of 100% at 5 wpi. Moreover, the infected mice were treated with abendazole at 5 weeks post-infection, and the serum levels of CAg in treated group began to increase rapidly at 2 days post-treatment (dpt) and reached a peak with detection rate of 100% (10/10) at 8 dpt, and then decreased gradually. By 42 dpt, the CAg levels decreased to the undetected level, but the anti- Trichinella antibodies were still detected in 100% of the infected mice. The novel assay appears to be sensitive for detection of antigens of T. spiralis and should be valuable to the early diagnosis and evaluation of the efficacy of chemotherapy in trichinellosis.     

Antischistosomal activity of artemether in experimental Schistosomiasis mansoni

OBJECTIVE: To evaluate the effect of intramuscular injection of artemether in mice experimentally infected with Schistosoma mansoni, at the time of infection, during schistosomula maturation and after the beginning of egg-laying. METHODS: Eighty adult females Balb/c mice were divided into 8 groups with 10 animals each. Seven groups were infected with S. mansoni using 60 cercariae for each animal, inoculated subcutaneously, and the remaining group was maintained without infection. Among the seven infected groups, six were treated with artemether, according to the following schedule: three groups received doses of 100 mg/kg on days 0, 20 or 60 after inoculation of the cercariae; the other three received 50 mg/kg of artemether, also on days 0, 20 or 60. At the end of the 9th, 10th and 11th weeks after infection all the mice infected with S. mansoni were submitted to fecal examination using the Kato-Katz technique. On the 80th day of the experiment, the surviving animals were sacrificed and submitted to perfusion of the portal system in order to recover the worms. Body, liver and spleen weights of each animal were determined at that time. RESULTS: A reduction in egg-laying and the number of worms recovered was observed in mice treated with artemether (50 or 100 mg/kg) on the 20th day after infection. The decrease in the number of worms was more notable among S. mansoni females. A significant decrease in liver and spleen weights was also seen on the 20th day among animals treated with 50 or 100 mg/kg of artemether and also among those that received the drug at a dose of 50 mg/kg 60 days after infection. CONCLUSIONS: Evidence of the antischistosomal activity of artemether was shown, even at a dose of 50 mg/kg, when the drug was administered during the schistosomula maturation period in the portal system of the vertebrate host.     

阿维菌素原药对昆明小鼠免疫功能的影响

目的探讨阿维菌素原药对昆明小鼠细胞免疫功能、体液免疫功能和非特异性免疫功能的影响。方法阿维菌素设3个剂量组20、10、5mg/kg和阴性对照组,连续给昆明小鼠染毒28d;T淋巴细胞增殖和迟发型变态反应（DTH）检测细胞免疫功能;抗体生成细胞数（PFC）和半数溶血值（HC50）测定检测体液免疫功能;腹腔巨噬细胞吞噬鸡红细胞、碳粒廓清试验和NK细胞活性测定检测非特异性免疫功能。结果 20mg/kg组小鼠T淋巴细胞增殖能力为0.76（阴性对照为0.86）,HC50为128.45（阴性对照为140.96）,PFC为89.21×106（阴性对照为113.33×106）;20和10mg/kg组碳廓清吞噬指数分别为5.59、5.61（阴性对照为7.96）,鸡红细胞吞噬指数分别为0.86、0.90（阴性对照为1.05）,以上结果均比阴性对照组明显降低,且差异有统计学意义﹙P〈0.01﹚。结论阿维菌素原药对昆明小鼠在细胞免疫功能、体液免疫功能和非特异性免疫功能方面均有抑制作用。     

食品级番茄红素对小鼠的免疫调节功能

目的研究番茄红素对免疫系统的调节作用。方法实验小鼠随机分成3组：对照组、低剂量组（10mg／kg）、高剂量组（20mg／kg）。低剂量组、高剂量组分别用色拉油稀释的番茄红素灌胃，对照组用色拉油灌胃。30天后检测小鼠的脾淋巴细胞增殖程度、NK细胞的杀伤活性、迟发性变态反应的程度、巨噬细胞吞噬功能。结果与对照组比较，高剂量组能显著增强脾淋巴细胞的增殖能力，提高自然杀伤细胞的活性和巨噬细胞吞噬功能，增强小鼠的足跖肿胀度（P〈0．05）。除增殖反应外，低剂量组其他指标与对照组比较，差异均无显著性。结论番茄红素具有增强小鼠免疫调节的功能。     

孕期服用叶酸预防和阻止小鼠腭裂的初步研究

目的:探讨叶酸对地塞米松所诱导小鼠腭裂的预防和阻止作用,为唇腭裂的预防提供新的途径。方法:选取NIH系小鼠,分为5组,第1组孕鼠在GD1-15经口灌胃0·6ml的生理盐水,第2、3、4组在GD1-15分别经口灌胃10mg/kg、30mg/kg、60mg/kg的叶酸;第5组在GD13-18经口灌胃60mg/kg的叶酸。5组孕鼠均在GD12腹腔注射50mg/kg醋酸地塞米松。在GD18断颈处死孕鼠,剖腹检查胎鼠吸收和死亡情况,对活的胎鼠检查腭裂发生情况。结果:第1组未用叶酸处理的孕鼠所产胎鼠腭裂的发生率为63·8%;第2组腭裂的发生率为64·9%;第3组腭裂的发生率为58·9%;第4组腭裂发生率为42·3%;第5组腭裂的发生率为65·3%。统计学分析第4组与第1组之间差异有显著性;第2、3、5组与第1组之间差异无统计学意义。结论:只有高剂量的叶酸(60mg/kg)才能降低胎鼠腭裂的发生率;并且要从妊娠的前期开始连续使用,才能达到良好的预防效果。     

The Indian langur: preliminary report of a new nonhuman primate host for visceral leishmaniasis.

Described are the susceptibility of the Indian langur (Presbytis entellus) to Leishmania donovani and the consequent haematological and serum biochemical changes. The host response to antileishmanial chemotherapy and the immunological profile were also examined. Each langur was inoculated intravenously with 1 x 10(8) amastigotes; a spleen biopsy carried out on day 35 post-infection (p.i.) revealed 10-13 L. donovani bodies per 500 cell nuclei, which reached a maximum of 130-195 at death (day 105-110 p.i.). The infected monkeys lost body weight, developed severe anaemia, lymphocytosis, hyperproteinaemia, hypergammaglobulinaemia, hypoalbuminaemia and an increase in the level of alkaline phosphatase and alanine aminotransferase (AAT). Treatment with sodium stibogluconate (60 mg Sb5+ per kg body weight intramuscularly for 10 days) reduced the number of spleen parasites (0-1 amastigotes per 500 cell nuclei) but after the therapy the parasites appeared in the skin, which had previously been free of infection. Relapse occurred on day 30 post-treatment (10-24 amastigotes per 500 cell nuclei) and the parasites were resistant to repeat intensive therapy (120 mg Sb5+ per kg per day x 30 days). The stibogluconate treatment caused a proportionate reduction in the haematological and biochemical parameters to normal values except for alkaline phosphatase and AAT, which remained elevated. The level of IgG antibodies, which rose during the infection, rapidly fell to the pretreatment value following the first therapeutic schedule and then increased a second time coinciding with relapse. Our findings suggest that langurs could serve as acceptable models for human visceral leishmaniasis.     

Immunogenicity and protective efficacy of DnaJ (hsp40) of Streptococcus pneumoniae against lethal infection in mice

The present study was carried out to evaluate the immunogenicity and protective efficacy of DnaJ (hsp40) of Streptococcus pneumoniae, by cloning the full-length DnaJ of S. pneumoniae and expressing in heterologous host E. coli BL-21 (DE3). PCR amplified DnaJ was ligated in pQE-30 expression vector and subsequently transformed in E. coli DH5alpha strain. Cloning of DnaJ was confirmed by double digestion and PCR, followed by DNA sequencing. The His-tag containing recombinant protein was purified by Ni-NTA affinity chromatography. To determine the immunogenicity of DnaJ, the mice (10 mice/group) were immunized by injecting 40 microg DnaJ protein/mouse i.p. There was a significant increase in IgG titres (2 x 10(5)) in mice immunized with DnaJ protein. Isotyping studies revealed that antibodies produced are predominantly IgG2a type indicating the predominance of Th1 response. A significant increase in lymphocyte proliferation was observed in mice immunized with DnaJ protein as compared to the control mice. Further, there was a significant increase in IL-2 and gamma-IFN levels in culture supernatants of splenocytes isolated from immunized mice. To determine the efficacy of DnaJ vaccination in eliciting protection, the mice were challenged with 1 x 10(5)cells of S. pneumoniae A66 type 3 capsular strain intra-nasally after 7 days of last immunization. All the control mice died within 2 days of post-infection, while 70% of animals immunized with DnaJ survived the lethal challenge by S. pneumoniae. The study reveals that immunization of mice with DnaJ elicits protective immunity against S. pneumoniae infection.     

Immunotherapy against murine experimental visceral leishmaniasis with the FML-vaccine

The fucose mannose ligand (Leishmania donovani FML)-saponin vaccine has earlier shown its immunoprophylactic potential against visceral leishmaniasis in the CB hamster (87.7% of parasite load reduction), Balb/c (84.4%) and Swiss albino mouse (85–93%) models. In this investigation its specific immunotherapeutic efficacy against L. donovani infection in Balb/c mice was studied. The effects of vaccine treatment on the humoral response, delayed type of hypersensitivity to promastigote lysate (DTH), cytokine levels in sera and reduction of the liver parasitic load of L. donovani infected mice, were examined. The types and subtypes of anti-FML antibodies increased significantly in the vaccinees over the saline and saponin controls. As expected for a saponin vaccine, the highest ratios were found in relation to IgG1, IgG2a and IgG2b (4.4, 5 and 2.5, respectively). The DTH response and the in vitro ganglion cell proliferative response against FML antigen were also significantly higher than controls (P<0.005). Concomitantly, an impressive and specific decrease of liver parasitic burden was detected only in vaccine-treated animals (94.7%). Our results indicate that the therapeutic FML-vaccine has a potent effect on modulation of the murine infection leading to the reduction of parasitic load and signs of disease, being a new potential tool in the therapy and control of visceral leishmaniasis.     

大鼠矽肺模型对绵羊红细胞抗原的免疫应答

目的　探讨大鼠矽肺模型对绵羊红细胞 (SRBC)抗原的免疫应答。方法　矽肺模型大鼠分别通过气道、腹腔给予SRBC ,观察其血清溶血素、血清与肺泡灌洗液特异性IgG水平的动态变化、皮肤迟发型变态反应 (DTH)以及肺引流淋巴结、肺泡灌洗液细胞总数和分类计数。结果　 (1 )第一次抗原免疫后第 7、1 2、2 0、2 5、32天 ,第二次抗原免疫后第 5、1 2、1 5天 ,矽肺气道免疫组大鼠血清溶血素半数溶血指数 (HC50 )分别为 47.4± 1 .0、52 .2± 4 .6、31 .1± 1 1 .9、43 .8± 3 .5、33 .6± 1 6 .8、49.0± 2 .3、92 .9± 2 0 .2、87.7± 5 .2 ,高于正常对照组 (分别为 40 .4± 1 0 .6、2 .8± 2 .5、0 .8± 0 .6、6 .6± 5 .8、1 .4±0 .1、36 .5± 1 6 .5、53 .0± 33 .2、2 .6± 2 .2 ) ,差异均有显著性 (P <0 .0 1 )。 (2 )第一次抗原免疫后第 1 2、2 0、2 5、32天 ,第二次抗原免疫后第 5、1 2、1 5、2 7天 ,矽肺气道免疫组大鼠血清特异性IgG(A4 90 nm值 )分别为 1 .67± 0 .1 9、1 .98± 0 .36、1 .1 2± 0 .50、1 .38± 0 .30、2 .75± 0 .1 5、2 .60± 0 .2 8、2 .86± 0 .1 0、2 .50±0 .2 0 ,高于正常对照组 (分别为 0 .59± 0 .30、0 .56± 0 .2 1、0 .2 1± 0 .1 6、0 .2 2± 0 .1 0、0 .81± 0 .2 5、0     

硒对正常小鼠免疫功能的影响

<正> 近年来微量元素对机体的作用已越来越受重视,市场上也出现了不少含微量元素的食品和药物。硒是谷胱甘肽过氧化物酶的基本成分,对机体有多方面的作用。硒对机体免疫功能也有作用。缺硒可导致血凝抗体降低。对羊红细胞免疫应答反应降低,机体对疾病的抵抗力降低,补硒可纠正或提高