Anulus fibrosus in bulging intervertebral disks

In this investigation the association of radial tears of the anulus fibrosus and bulging of the intervertebral disk was studied. An index of disk bulging was measured in sagittal anatomic sections in 149 lumbar disks from 31 cadavers. The indexes of disk bulging were correlated with stages of disk development and the presence of an annular tear. The largest disk-bulging indexes were always associated with radial tears of the anulus. Eighty-four percent of the disks with radial tears had disk-bulging indexes greater than 2.5 mm. Most normal adult disks had an index of less than 2.5 mm. The results challenge the concept that the anulus fibrosus is intact in bulging disks, although ruptured in herniated disks.     

Borrelia burgdorferi infection and immunity in mice deficient in the fifth component of complement.

When immunocompetent mice are inoculated with Borrelia burgdorferi, they develop acute arthritis and carditis that undergo spontaneous regression despite the persistence of infection. Specific T- and/or B-cell immunity appears to be necessary for resolution of disease manifestations. Humoral immune responses to B. burgdorferi are also important in prevention of B. burgdorferi infection, in that passive transfer of immune sera or protective monoclonal antibodies prevents the spirochete from establishing infection. It has previously been suggested that complement is necessary for effective antibody-mediated host responses against B. burgdorferi. To investigate the role of complement in the pathogenesis and prevention of Lyme disease, we compared the responses to B. burgdorferi challenge inoculation of mice genetically deficient in the fifth component of complement (C5) with those of C5-sufficient mice. All C5-deficient strains tested were susceptible to B. burgdorferi infection, and disease manifestations underwent regression in a similar time-course to those of complement-sufficient mice. Moreover, passive immunization of C5-deficient mice with either immune rabbit sera or neutralizing monoclonal antibody protected them from challenge infection. These results demonstrate that the expression of Lyme disease is not altered in mice deficient in C5 and that C5-mediated complement activation is not necessary for antibody-mediated protection from infection.     

P55, an immunogenic but nonprotective 55-kilodalton Borrelia burgdorferi protein in murine Lyme disease.

Immunization of C3H mice with P55 (previously called S1), a 55-kDa Borrelia burgdorferi antigen that is immunogenic after infection, elicited a strong antibody response but did not protect mice against B. burgdorferi challenge. Mice immunized with a P55 fusion protein in complete Freund's adjuvant developed anti-P55 antibodies, detectable at a titer of 1:10,000 by immunoblotting. To determine, if a protective response had been elicited, P55-vaccinated mice were fed upon by ticks infected with B. burgdorferi. The frequency of B. burgdorferi infection was similar in P55-immunized and control mice, and spirochetes were not destroyed within ticks that fed on P55-vaccinated mice. P55 is an immunogenic antigen that does not induce a protective response in the vertebrate or invertebrate host.     

B7-1 and B7-2 monoclonal antibodies modulate the severity of murine Lyme arthritis.

We assessed the role of B7-1 and B7-2 costimulatory molecules on the course of murine Lyme borreliosis because experimental Lyme arthritis is dependent, at least partially, upon the development of the host immune response and these costimulatory molecules have been implicated in CD4+ T-cell differentiation. We demonstrated that Borrelia burgdorferi infection upregulated the surface expression of B7-1 and B7-2 in macrophages and B7-2 expression in B cells. Anti-B7-2 monoclonal antibody (MAb) or both anti-B7-2 and anti-B7-1 MAbs produced a dose-dependent increase in the severity of Lyme arthritis in C3H/HeN mice. In contrast, the administration of an anti-B7-1 MAb reduced the degree of arthritis. These effects occurred independently of significant alteration in B. burgdorferi-specific immune responses, including splenocyte proliferative responses to B. burgdorferi, B. burgdorferi antibody levels and specificity, and mRNA levels of gamma interferon, interleukin-4 (IL-4), IL-10, and IL-12 in the spleen. These results demonstrate that signaling delivered by B7-1 and B7-2 plays a role in determining the severity of acute murine Lyme arthritis.     

Partial destruction of Borrelia burgdorferi within ticks that engorged on OspE- or OspF-immunized mice.

We determined whether Borrelia burgdorferi outer surface proteins (Osps) E and F could elicit immune responses useful for a Lyme disease vaccine. Thirty days after challenge with B. burgdorferi, mice produced antibodies to OspE but not OspF, whereas antibodies to OspF were present in sera of mice obtained 90 days after infection. Examination of sera from patients with Lyme disease revealed antibodies to OspF in a small number (14%) of early-stage disease patients but in a majority (58%) of patients with late-stage disease, while antibodies to OspE were rarely detected in patients. Mice immunized with recombinant OspE or OspF produced high titers of antibodies to OspE or OspF, respectively. OspF-immunized mice were partially protected from both intradermal syringe challenge and tick-mediated transmission of B. burgdorferi while vaccination with OspE did not confer immunity. B. burgdorferi organisms were, however, substantially destroyed within ticks that engorged on either OspE- (75% reduction in the number of spirochetes within the ticks, compared with controls) or OspF (90% reduction in the number of spirochetes within the ticks)-immunized mice.     

Effect of a new synthetic serum replacement on insulin and somatostatin secretion from isolated rat pancreatic islets in long-term culture

Summary Serum contains insulin degrading components. We have evaluated the insulin and somatostatin secretion from isolated rat pancreatic islets during a 2-wk culture period using three different serum-containing media, and one serum-free medium with a synthetic serum replacement. Islets incubated in serum-free medium elicited significantly higher daily insulin and somatostatin secretions than islets incubated in the serum-containing media. After a 2-wk culture period, islets from the serum-free medium secreted significantly more insulin and somatostatin than islets cultured in other media when stimulated with 25 mmol/liter glucose together with 15 mmol/liter theophylline. We conclude that the serum-free medium is superior for long-term culture of rat pancreatic islets.     

痛

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