Neuroinvasion by a Creutzfeldt-Jakob disease agent in the absence of B cells and follicular dendritic cells

With the potential spread of bovine spongiform encephalopathy to people as a variant Creutzfeldt-Jakob disease (CJD), it becomes critical to identify cells in the periphery that carry infection. Initial work with scrapie agents suggested that B cells were central vectors for neuroinvasion. Subsequent studies indicated that B cells played an indirect role by promoting the development of follicular dendritic cells (FDCs) that accumulate abnormal prion protein (PrP). The mechanism for the role of FDCs, however, has not been clear. To further dissect potential B cell functions that contribute to neuroinvasion, we inoculated a CJD agent into mutant mice that (i) lacked B cells, (ii) had B cells unable to secrete Ig, or (iii) could secrete only IgM. Remarkably, all these mice developed disease with practically indistinguishable incubation times. The demonstration that neither immune complexes nor B cells were required for neuroinvasion from the periphery mandates a reanalysis of the accepted view of the essential role of B cells and FDC in these infections. Moreover, immune complexes were not required for the accumulation of pathologic PrP on the surface of FDCs, suggesting that PrP can bind to FDCs autonomously or by means of another factor. Wild-type mice had incubation times approximately 50 days less than all mutant mice at the same peripheral doses, indicating that an intact immune system may increase agent uptake and delivery, but this condition is not essential. Specifically, the evidence to date suggests that IgG may enhance pivotal agent interactions with migratory myeloid cells.     

Immortality of cell cultures derived from brains of mice and hamsters infected with Creutzfeldt-Jakob disease agent.

Isolates from six patients with Creutzfeldt-Jakob disease (CJD) were injected into various strains of hamsters and mice, and the infective agent was propagated. Serially passaged cultures were established from these CJD agent-infected brains and from uninfected control brains. All healthy cultures (21 out of 21) from CJD agent-infected brains became immortal and/or transformed. In contrast only 3 out of 13 normal brain cultures became immortal, and the rest died out with serial propagation in vitro. The fact that permanent cell lines were readily derived from multiple rodent strains and all CJD isolates tested suggests that a transforming capability is an intrinsic property of CJD agents. This conclusion is supported by demonstrations of in vitro cell transformation by CJD infectious brain fractions. Although the molecular mechanism of transformation events associated with the CJD agent is not presently known, a provocative possibility is that the CJD agent has a direct effect on the host genome by mechanisms analogous to those known for slowly oncogenic retroviruses.     

Low-intensity LED therapy (658 nm) on burn healing: a series of cases

The objective of this study was to evaluate the effects of LED on burns healing. Five patients with skin burns were submitted to photobiomodulation by LED, GaAsIP diode, (λ 658 nm) with 40 mW, 7 J/cm² on every other day. Biopsies of burned skin were performed and the healing process was photographed. Patients with bilateral burns were used as self-control, having one limb being irradiated and the contralateral limb irradiated with placebo. The burns treated with LED showed higher epithelization, with keratinocytes and fibroblasts proliferation, increased collagen synthesis, decreased pain, and pruritus. In conclusion, there was a faster clinical improvement in the irradiated limbs.     

Blood borne transit of CJD from brain to gut at early stages of infection

Background  

In Creutzfeldt-Jakob disease (CJD) and other related transmissible spongiform encephalopathies it is critical to understand the various pathways by which the infectious agent spreads to different organs.     

Quantitative recovery of scrapie agent with minimal protein from highly infectious cultures

There are few reports on the isolation, quantitative recovery, and relative purification of infectious particles that cause scrapie, Creutzfeldt-Jakob disease (CJD) and epidemic bovine spongiform encephalopathy (BSE). Because pure prion protein (PrP) has failed to show significant infectivity, it is critical to find other molecules that are integral agent components. Only complex diseased tissues such as degenerating brain have been fractionated, and agent recoveries have been quite low in concentrated abnormal prion protein (PrP-res) preparations. To simplify the purification of infectious particles, we evaluated a monotypic cell line that continuously produced high levels of the 22L scrapie agent (N2a-22L). A new rapid and accurate GT1 culture assay was used to titrate infectivity in six representative sucrose gradients. We developed a streamlined approximately 3-h procedure that yielded full recovery of starting infectivity in fractions with only a few selected protein bands (representing <1% of starting protein). Infectious particles reproducibly sedimented through >30% sucrose steps, whereas PrP and PrP-res sedimentation varied depending on the conditions used. Both normal and abnormal PrP could be largely separated from infectivity in a single short centrifugation. Because no foreign enzymes were added to achieve reasonably purified infectious particles, these preparations may be used to elicit diagnostic antibodies to foreign agent proteins.     

Formulation,stability study and preclinical evaluation of a vaginal cream containing curcumin in a rat model of vulvovaginal candidiasis

Owing to the growing resistance among isolates of Candida species to usual antifungal agents and the well‐known therapeutic potential of curcumin, the purpose of this study was to develop and validate a vaginal formulation containing this substance and to evaluating its effectiveness in the treatment of experimental vulvovaginal candidiasis. Curcumin was incorporated in a vaginal cream in three concentrations (0.01%, 0.1% and 1.0%). The different concentrations of the cream and its controls were intravaginally administered in an immunosuppressed rat model to evaluate the efficacy in the treatment of experimental vulvovaginal candidiasis. Samples of the cream were also subjected to centrifugation and physical stability tests and an analytical method for quantification of curcumin was validated based on HPLC. The formulation was stable and the HPLC method could be considered suitable for the quantitative determination of curcumin in the cream. After 6 days of preclinical study, the number of infected animals was 1/6 in all groups treated with curcumin vaginal cream and the fungal burden showed a progressive reduction. Reduction in the inflammatory infiltrate was observed in the group treated with 1.0% cream. Vaginal cream containing curcumin could be considered a promising effective antifungal medicine in the treatment of vulvovaginal candidiasis.     

Intramembrane particle distribution and lectin binding of glioblastoma cells after long term subculture

Summary Human glioblastoma cells in long-term monolayer culture showed an even distribution of intramembrane particles (IMP) on all surfaces of the plasma membrane; junctional complexes were rearely observed and rectilinear arrays were not seen. Cells treated with Con A-ferritin an dRicin II-ferritin showed an even distribution of lectin receptors and under conditions used no capping occurred. Lectin-ferritin complexes were taken up into pinocytotic vesicles. Cleaved preparations of Ricin II-ferritin treated cells showed no change in the distribution of IMP.The authors wish to thank Dr. E. E. Manuelidis for invaluable advice, J. P. Albert and P. Johnson for expert technical assistance, and Mrs. M. Silberberg for excellent secretarial work.This work was supported by NIH Grants GM 02140-05 and CA 15044-03 and USPHS 5 P01 NS-06208-11.     

Renin in glioblastoma multiforme and its role in neovascularization

Significant proliferation of capillaries with hyperplastic vascular endothelium is one of the characteristic histologic features of glioblastoma multiforme (GBM). It has been shown that the renin-angiotensin II cascade stimulates new vessel formation. The presence of renin in several types of highly vascularized neoplasm suggests that it may also be implicated in the mechanism of tumor angiogenesis. In order to study the possible relationship of renin to GBM, immunohistochemical search for human renin was carried out in ten instances of such a tumor. Eight of these cases demonstrated renin-containing neoplastic astrocytes, whereas seven cases of reactive gliosis and six cases of low-grade astrocytoma revealed no renin-containing cells. The immunostaining was not present after preabsorption of the renin antiserum with pure human renin or substitution of preimmune serum for the specific renin antiserum. Because it has also been demonstrated that a product of renin, angiotensin II, has angiogenic properties, it seems reasonable to postulate that renin, through angiotensin II, may play a role in the mechanism of GBM-associated neovascularization.     

Immunohistochemistry of capillary hemangioblastoma. Immunoperoxidase-labeled antibody staining resolves the differential diagnosis with metastatic renal cell carcinoma, but does not explain the histogenesis of the capillary hemangioblastoma

We used a battery of antigens to determine whether immunohistochemistry can (a) contribute to resolving the histogenesis of the stromal component of the capillary hemangioblastoma, and (b) answer cases of difficult pathologic differential diagnosis with metastatic clear cell carcinoma. The stromal cells of the capillary hemangioblastoma are antigenically polymorphous and may express immunoreactive erythropoietin, renin, keratin, Leu M1, Leu 7, actin, neuron-specific enolase, S100 protein, and glial fibrillary acidic protein. However, the use of epithelial membrane antigen allows certain histopathologic distinction between capillary hemangioblastoma and metastatic clear cell carcinoma.