Humoral immunosuppressive substance in mice bearing plasmacytomas

The mechanism by which plasmacytomas (PC) depress the primary immune response to sheep red cells was investigated by determining the ability of normal spleen cells to produce antibody when enclosed in Millipore chambers and implanted in PC-bearing mice. Chamber-enclosed normal spleen cells implanted in PC-bearing mice responded poorly to the sheep red cells when compared to similar cells enclosed in chambers and implanted in normal mice or in mice with other lymphoid and nonlymphoid tumors. The data suggest that PC-induced immune suppression is mediated by a humoral factor.     

Rapid immunological induction of murine lymphomas: evidence for a viral etiology

A graft-versus-host reaction induced in (SJL/J x C57BL/1)F(1) hybrid mice by injection of SJL/J spleen cells resulted in 100 percent incidence of tumors at 40 days. Transplantation studies revealed that the tumors were antigenically C57BL/1. Since both SJL/J and C57BL/1 mice carry tumorigenic virus, the evidence suggests a viral etiology.     

Malignant melanoma: specific immunity induced by bacillus Calmette-Guérin in BALB-c mice

Previous treatment of BALB/c mice with bacillus Calmette-Guérin (BCG) will significantly protect them against intramuscular challenge of S-91 melanoma but not against a mammary carcinoma or a methylcholanthrene-induced sarcoma. Lymphocyte-mediated cytotoxicity studies correlate with in vivo data in showing that BCG-immune lymphocytes are specifically cytotoxic to S-91 melanoma target cells but not to the carcinoma or sarcoma target cells.     

Virus induction of osteosarcomas in mice

A virus extractcd from an osteosarcoma of a mouse produces simiillar fumors when Injected into newborn mice. The original tumor appeared spoiltaneously in an untreated CFI male. The time between inoculation with virus and detection of bone sarcoma has been as short as 23 days.     

Quantitation of strain BALB-c mouse peritoneal cells

Total and differential counts of the peritoneal cells of male and female BALB/c mice aged 10 days to over 2 years demonstrate that the increase in cell number that occurs in mice over 2 months old is due entirely to an increase in lymphocytes. The number of peritoneal macrophages in BALB/c females is maintained at a constant level for 22 months. The stability of the macrophage population in contrast to the increase in numbers of lymphocytes suggests that the body pools of these two cell types are not related.     

Rapid induction of allergic encephalomyelitis in rats without the use of mycobacteria

Rats, in contrast to certain other species of animals reported, have a striking capacity to develop allergic encephalomyelitis within 2 to 3 weeks following one injection of spinal cord antigen combined with Freund's incomplete adjuvant-that is, adjuvant prepared without addition of killed mycobacteria.     

Diabetes mellitus: induction in mice by encephalomyocarditis virus

Hyperglycemia and lesions of the pancreatic islets of Langerhans developed in some, but not all, adult mice infected with a variant of the encephalomyocarditis virus. Large amounts of virus were recovered from the pancreas during acute stages of infection. At this time blood glucose concentrations were markedly elevated and the islets of Langerhans exhibited focal necrosis and degranulation of beta cells. Evidence of abnormal glucose metabolism persisted for varying periods after recovery from the infection. The islets of Langerhans of chronically hyperglycemic mice were distorted and decreased in size, and the beta cells were degranulated. Encephalomyocarditis virus appears to cause diabetes mellitus by reducing the mass of functional beta cells of the islets of Langerhans.     

Lymphomas in mice: failure of induction after a graft-versus-host reaction

A mild graft-versus-host reaction induced in (BALB/cJ x DBA/2J) F(1) mice by the administration of parental spleen cells that differ at several weak histocompatibility loci did not influence the development of lymphomas in these animals. Rous sarcoma virus also failed to induce tumors in the runt and control animals. Breast carcinomas, presumably due to contamination of the inoculums with mammary tumor virus, occurred in those experimental groups given parental cells, whether or not they were viable or immunologically competent. We found no evidence that the immunologic process-as represented by the graft-versus-host reaction-is causally related to the induction of neoplasia.     

Homologous viral interference: induction by RNA from defective particles of vesicular stomatitis virus

The viral RNA isolated from the defective particles of vesicular stomatitis virus was capable of interfering with the replication of this virus in chick embryo cells. The data indicate that the interfering ability of the defective particles of this virus is due to their nucleic acid component.     

A macrophage-derived factor required by plasmacytomas for survival and proliferation in vitro

Plasmacytoma (PCT) cell lines dependent for proliferation and survival on a factor elaborated by the murine macrophage cell line, P388D1, were established in vitro. Adherent peritoneal cells induced by pristane produced 50-fold greater amounts of this activity in vitro than did resident cells. The molecules responsible for plasmacytoma growth were distinct from a number of characterized factors including interleukin-1, -2, and -3, macrophage colony-stimulating factor, B-cell stimulatory factor-1, B-cell growth factor II, epidermal growth factor, transforming growth factor-beta, and gamma- and beta-interferon, none of which were able to support the growth of the factor-dependent PCT cell lines. These results suggest that PCT growth factor may be a novel factor that has not been previously characterized and, further, that its production is associated with the pristane-induced, chronic peritoneal inflammatory response that precedes plasmacytoma formation.     

Rapid loss of tolerance induced in weanling NZB and B-W F1 mice

Young adult mice (30 to 43 days old) of autoimmune NZB and BIW F(1) strains failed to develop immunologic tolerance when treated with ultracentrifuged bovine gamma globulin and then challenged 12 days later. By contrast, weanling NZB and B/ W F(1) mice (18 to 25 days) as well as weanling C3H mice (16 to 19 days) became tolerant and had no serum antibody 12 days after challenge. The C3H mice remained unresponsive, but NZB and B! W F(1) mice produced antibody between days 27 and 41. The rapid loss of previously established tolerance to foreign antigens could have its parallel in the loss of tolerance to autoantigens with subsequent development of lupus nephritis and Coombs' positive hemolytic anemia in these animals.     

Photic induction of mPer1 and mPer2 in cry-deficient mice lacking a biological clock

Mice lacking mCry1 and mCry2 are behaviorally arrhythmic. As shown here, cyclic expression of the clock genes mPer1 and mPer2 (mammalian Period genes 1 and 2) in the suprachiasmatic nucleus and peripheral tissues is abolished and mPer1 and mPer2 mRNA levels are constitutively high. These findings indicate that the biological clock is eliminated in the absence of both mCRY1 and mCRY2 (mammalian cryptochromes 1 and 2) and support the idea that mammalian CRY proteins act in the negative limb of the circadian feedback loop. The mCry double-mutant mice retain the ability to have mPer1 and mPer2 expression induced by a brief light stimulus known to phase-shift the biological clock in wild-type animals. Thus, mCRY1 and mCRY2 are dispensable for light-induced phase shifting of the biological clock.     

Concanavalin A in vivo: induction of hemorrhagic skin lesions (Arthus-like reactions) in mice

Concanavalin A injected into the skin of mice induced the formation of hemorrhagic Arthus-like lesions. No lesions resulted if concanavalin A was adsorbed with insoluble (a2)- macroglobulin or if mice were first treated with nitrogen mustard. The ability of concanavalin A, phytohemagglutinin, or pokeweed mitogen to induce skin lesions seemed to parallel their ability to precipitate serum proteins.     

Segregation of loci for C-type virus induction in strains of mice with high and low incidence of leukemia

Multiple genetic loci for induction of murine leukemia viruses are demonstrated in cells of the high leukemic incidence C58 mouse strain. The biologic properties of viruses at C58 inducibility loci are clearly distinguishable from those of viruses activated from mouse cells containing a locus for virus induction of the low leukemia incidence BALB/c strain. These findings are consistent with the hypothesis that the genes for virus induction in normal mouse embryo cells represent viral structural information.     

鸡蛋中沙门氏菌的快速检测

选择江苏省不同地区来源的鸡蛋296枚,分别取蛋黄蛋清混合液以沙门氏菌增菌液快速增菌.取增菌培养物100 μl,离心去上清后,重新悬浮于100 μl超纯水中;以煮沸法制备可能存在的细菌DNA模板.通过对沙门氏菌毒力岛SPI-3的mgtC基因的PCR快速检测,确定其中18.24%的鸡蛋为沙门氏菌阳性.通过与细菌分离检测结果对比,揭示该方法明显提高了沙门氏菌的检出率,表明PCR是一种快速、敏感和高度特异性的沙门氏菌检测方法,值得在畜产品沙门氏菌的检测中推广应用.     

茉莉离体快繁体系的建立

以WPM为基本培养基比较了不同6-BA和IBA配比对茉莉茎段芽诱导的影响,及不同温度条件下不同6-BA和IBA配比对茉莉芽增殖的影响;并以1／2WPM为培养基,比较了不同NAA浓度处理及不同生根方法对离体芽生根的影响。结果表明：6-BA 2．0mg／L+IBA 0．1 mg／L处理诱导率最高,达96．75％,极显著高于其他处理;而35℃下6-BA1．0mg／L+IBAO．2mg／L组合对试管苗的增殖效果最好,增殖系数为5．31;最佳生根培养方式为1／2WPM+NAA 1．0 mg／L处理7 d后转入空白培养基,进行两步法生根,生根率为98．41％。从而初步建立了茉莉的离体快繁体系。