Adjuvant-dependent modulation of Th1 and Th2 responses to immunization with beta-amyloid

The role of adjuvant on the T(h)1 and T(h)2 immune responses to Abeta-immunotherapy (Abeta(42 )peptide) was examined in wild-type mice. Fine epitope analysis with overlapping oligomers of the Abeta(42) sequence identified the 1-15 region as a dominant B cell epitope. The 6-20 peptide was recognized only weakly by antisera from mice administrated with Abeta(42) peptide formulated in complete Freund's adjuvant (CFA), alum or TiterMax Gold (TMG). However, mice immunized with Abeta(42) mixed with QS21 induced a significant antibody response to the 6-20 peptide. The only T cell epitope found was within the 6-28 sequence of Abeta(42). QS21 and CFA induced the strongest humoral response to Abeta, alum was intermediate, and TMG the weakest adjuvant. Analysis of antibody isotypes specific for Abeta indicates that alum induces primarily T(h)2-type immune response, whereas TMG, CFA and QS21 shift the immune responses toward a T(h)1 phenotype. Stimulation of splenocytes from Abeta-immunized mice with Abeta(40) peptide induced strikingly different cytokine expression profiles. QS21 and CFA induced significant IFN-gamma, IL-4 and tumor necrosis factor-alpha expression, whereas alum induced primarily IL-4 production. As T(h)1-type immune responses have been implicated in many autoimmune disorders, whereas T(h)2-type responses have been shown to inhibit autoimmune disease, the choice of adjuvant may be critical for the design of a safe and effective immunotherapy for Alzheimer's disease.     

Microencapsulation of tumor necrosis factor oligomers: a new approach to proinflammatory cytokine inhibition.

Antisense oligonucleotides offer great therapeutic potential provided adequate intracellular penetration can be achieved. In this study, we evaluated the effectiveness of microencapsulating antisense oligonucleotides to tumor necrosis factor (TNF) in suppressing TNF release in vitro and in vivo. Microencapsulation of TNF oligomers was performed using albumin to produce microcapsules 0.6-1.0 mum in size that target phagocytic cells. Albumin microcapsules containing fluoresceinated TNF oligomers were incubated with U-937 cells to observe uptake. Microcapsules were added to whole blood and stimulated with Escherichia coli endotoxin. Endotoxin was given intravenously (i.v.) to rats along with 100 mug microencapsulated TNF oligomers to determine TNF inhibition and animal survival. E. coli was given intraperitoneally (i.p.) along with gentamicin and microencapsulated TNF oligomers to assess TNF inhibition and animal survival. The duration of microencapsulated antisense TNF oligomers was also determined in vivo. The results demonstrated rapid uptake of the microcapsules by macrophages after 2 h and 4 h incubation. There was improvement in TNF inhibition in vitro and improved animal survival by microencapsulated antisense in both endotoxin (100% survival) and peritonitis models (70% survival) compared with free antisense oligomers in solution. Microencapsulation extended the duration of action of the oligomers to 72 h. Intracellular targeting of macrophages with antisense oligomers to TNF by microencapsules as a delivery system improves TNF inhibition using the models of whole blood endotoxin stimulation and endotoxic shock and peritonitis in rats.     

Immunological Studies on the Envelope Component of Venezuelan Equine Encephalomyelitis Virus

Treatment of purified Venezuelan equine encephalomyelitis virus with the nonionic detergent Triton X-100 permitted spearation of the envelope from the core component. The isolated envelope was a noninfectious immunogen which reacted in hemagglutination, hemagglutination inhibition, complement fixation, and neutralization serological reactions.     

Mechanisms of Neuronal Death in Alzheimer's Disease

Recent data in cell culture has shown that brain neurons are particularly vulnerable to degeneration by apoptosis. Further the inducers that activate the program (e.g. β-amyloid, oxidatative damage, low energy metabolism) correspond to conditions present in the Alzheimer's disease (AD) brain. This suggests the possibility that apoptosis may be one of the mechanisms contributing to neuronal loss in this disease. Indeed, some neurons in vulnerable regions of the AD brain show evidence of DNA damage, nuclear apoptotic bodies, chromatin condensation, and the induction of select genes characteristic of apoptosis in cell culture and animal models. This suggests the existence of apoptosis in the AD brain, a hypothesis also consistent with evolving research in one of the regulatory functions of the presenilin genes. On the other hand, DNA damage is present in the majority of neurons in vulnerable regions in early and mild cases. In most tissues, cells in fully activated apoptosis degenerate and are removed within hours to days and thus it seems all DNA damage is unlikely to signify terminal apoptosis. The presence of extensive DNA damage suggests an acceleration of damage, faulty repair process, loss of protective mechanisms, or an activation and arrest of aspects of the apoptotic program. DNA damage is unlikely to be an artifact of postmortem delay or agonal state. The existence of protective mechanisms for neurons may exist as these cells are nondividing and essential. In this context it is interesting that Bcl-2 is upregulated in most neurons with DNA damage. Further, at least one DNA repair enzyme is also upregulated. Thus it appears as if neurons are in a struggle between degeneration and repair. As research advances it is critical to reduce the stimuli that cause the neuronal damage and discover the key intervention points to assist neurons in the repair processes.     

Open-field behavior and the peripheral sympathetic nervous system in the MR/N and MNR/N rat strains

The Maudsley Reactive (MR) and Maudsley Non-Reactive (MNR) strains of rats, respectively selected by P. L. Broadhurst for high and low open-field defecation (OFD), were acquired by the National Institutes of Health in 1963 at the 21st generation of inbreeding and have been inbred as the MR/N and MNR/N strains at that location for more than 40 generations. The present experiment shows that, despite the lack of deliberate selection for more than 40 generations, the strains still differ predictably in OFD. Strain differences in open-field activity, originally found to be inversely associated with those in OFD, have also been preserved. The existence of an association between the peripheral sympathetic system and OFD originally established in the Har derivation of the Maudsley strains was also confirmed in the MR/N and MNR/N strains: MR/N male rats, with the relatively higher levels of OFD, exhibited lower concentrations of norepinephrine (NE) in spleen and descending colon than MNR/N rats. The pattern of biochemical and morphological findings obtained in this study and previous data indicate that the MNR/N and the MNR/Har strains are both derived from the British stocks of this strain carrying the agouti allele (AA). A distinction should be made between these strains and the MNRA/Har strain, which carries the nonagouti allele (aa) and which has been genetically isolated from the Nonreactive strains bearing the agouti allele since early in the selection experiment.Supported by Grant GM 28874 from the National Institute of General Medical Sciences.     

Comparison of arsenic-induced cell transformation, cytotoxicity, mutation and cytogenetic effects in Syrian hamster embryo cells in culture

Sodium arsenite and sodium arsenate were observed to inducemorphological transformation of Syrian hamster embryo cellsin a dose-dependent manner. A linear dose-dependence with aslope of 1 was observed with both compounds when the data wereplotted on a log-log graph. The trivalent sodium arsenite was> 10-fold more potent than the pentavalent sodium arsenate.The compounds also exhibited toxicity; however, transformationwas observed at non-toxic as well as toxic doses. At low doses,enhanced colony-forming efficiency of the cells was observed.To understand the mechanism of arsenic-induced transformation,the genetic effects of the two arsenicals were examined overthe same doses that induced transformation. No arsenic-inducedgene mutations were detected at two genetic loci. However, celltransformation and cytogenetic effects, including endoreduplication,chromosome aberrations, and sister chromatid exchanges wereinduced by the arsenicals with similar dose-responses. Theseresults support a possible role for chromosomal changes in arsenic-inducedtransformation.     

The radioprotector WR1065 reduces radiation-induced mutations at the hypoxanthine-guanine phosphoribosyl transferase locus in V79 cells

N-(2-mercaptoethyl)-lt3-diaminopropane (WR1065) protects againstradiation-induced cell killing and mutagenesis at the hypoxanthine-guaninephosphoribosyl transferase (HGPRT) locus in V79 Chinese hamsterhing fibroblast cells. At a concentration of 4 mM, WR1065 wasfound to be effective in protecting against radiation-inducedcell lethality only if present during irradiation, e.g., a dosemodification factor (DMF) of 1.9. No protective effect was observedif the protector was added within 5 min after irradiation or3 h later, e.g., DMFs of 1.0 and 1.1, respectively. The effectof WR1065 on radiation-induced mutation, expressed as resistanceto the cytotoxic purine analogue 6-thioguanine (HGPRT), wasalso investigated. In contrast to the treatment-schedule dependencefor protection by WR1065 against cell killing, this agent waseffective in reducing radiation-induced mutations regardlessof when it was administered. Following a dose of 10 Gy of ⁶⁰Co-rays, the mutation frequencies observed per 10⁶ survivors were77 ± 8, 27 ± 6, 42 ± 7, and 42 ±7 for radiation only, and WR1065 present during, immediatelyafter, or 3 h after irradiation. These data suggest that althougha segment of radiation-induced damage leading to reproductivedeath cannot be modulated through the postirradiation actionof WR1065, processes leading to the fixation of gross geneticdamage and mutation induction in surviving cells can be effectivelyaltered and interfered with leading to a marked reduction inmutation frequency.     

Partial dehiscence of a porcine prosthesis in association with aortic annular separation producing a false aneurysm of the ascending aorta

A 44-year-old man developed intermittent left bundle branch block followed by complete heart block 18 months after aortic valve replacement, and aortic insufficiency and hemolytic anemia 5 years postoperatively. These abnormalities were associated with operative findings (7 years after aortic valve replacement) of total disruption of the aorta at the level of the aortic annulus. Echocardiographic findings of an enlarged and unusually shaped "aortic root" and angiographic findings of abnormally high origin of the coronary arteries relative to the valve ring, which should have suggested the diagnosis 2 years prior to successful surgical repair, are presented.     

Macromolecular DNA-damage in murine and human leukemic and lymphoid cells after in vitro exposure to ASTA Z 7557 (INN mafosfamide)

Summary Cyclophosphamide (CPA) is widely used against leukemic and lymphoproliferative diseases, but in vitro studies on response to this agent so far have been limited to instable derivatives with poor galenic properties. ASTA Z 7557 is a newly synthesized activated cyclophosphamide that circumvents the need for hepatic activation and has good stability. The critical cytotoxic lesions after exposure to bifunctional alkylating agents presumably are DNA interstrand crosslinks (ISC). We have, therefore, examined the formation and apparent removal of ISC after in vitro treatment with ASTA Z 7557 by use of the highly sensitive alkaline elution technique. Survival of murine L1210 cells was determined after 1 hour in vitro exposure with a D 37 value of 5.7 g/ml (from the initial shoulder part of the survival curve) and a Do value of 1.5 g/ml (from the exponential part of the curve). Previous labelling of L1210 cells by ¹²⁵IUdR simplified the alkaline elution procedure but there was some cytotoxicity of the radiochemical itself with a reduction of cloning efficiency from 77% to 61 %. The maximum of ISC was observed at 6 h after initiation of treatment with much of the damage apparently removed at 24 h. The simultaneous presence of DNA single strand breaks (SSB), however, confounds the analysis of DNA damage at 24 h and early cytolysis and unaided death of human lymphocytes often preclude the analysis of macromolecular damage at this time. Human peripheral blood cells isolated from patients with leukemic or lymphoproliferative diseases showed a remarkable heterogeneity with regard to the formation of ISC at 3 h. Thus, analysis of macromolecular damage may become an additional prognostic factor for response to CPA beyond the morphologic classification of these diseases.     

The association between decision-making skills and subjective decision outcomes among administrative officers in the Swedish Social Insurance Agency

Social insurance administrative officers’ decision-making skills influence their efficiency at work and their general well-being. At work their tasks are characterised by complexity and a need for order and accountability. Moreover, cases should usually be handled and finalised within the imposed time frames. We investigated skills related to decision-making success among social insurance officers. In total, 118 administrative officers at the Swedish Social Insurance Agency (66% response rate) responded to questions on scales and measures relating to cognitive-rational, socio-emotional and time approach features of decision-making skill. In addition, they responded to questions on three scales pertaining to outcomes of everyday decisions in terms of subjective everyday difficulties, tendencies to burnout and depressive symptoms. The results showed that cognitive-rational competence was associated with lower reports of subjective everyday difficulties and depressive symptoms and thereby contributed to the explained variance in decision outcomes. Furthermore, socio-emotional and time approach features of decision-making skills contributed to the explanation for subjective everyday difficulties, tendencies to burnout and depressive symptoms. The results corroborate the basic assumption and usefulness of a broad approach in the definition and assessment of decision-making skills in human service professions in general, and of administrative officers in social insurance agencies in particular. Recommendations for future research and the implications of the results are discussed.