Enzymatic hydrolysis of (di)methacrylates and their polymers

Abstract – Di- and monomethacrylates hydrolyze to methacrylic acid and the alcohol part at neutral pH catalyzed by an unspecific esterase (hydrolase) and by enzymes in saliva. The rate constants of the enzymatic hydrolysis of various (di)methacrylates increase in the following order: HPMA < BISGMA < LAMA < DECMA < TEGDMA < UEDMA < DEGDMA. Esterase added to aqueous slurries of various powders made of polymerized BISGMA/TEGDMA-mixtures gave rise to liberation of methacrylic acid, presumably deriving from degradation of those of the dimethacrylates only bonded in the matrix by one end of the molecule. It was estimated that a TEGDMA-polymer will be hydrolyzed faster than a BISGMA-polymer. It is proposed that hydrolases in saliva increase the wear rate of composite resin fillings.     

Testicular function in eight patients with seminoma after unilateral orchidectomy and radiotherapy

Testicular function was monitored in eight patients with low stage seminoma who were treated with radiotherapy following unilateral orchidectomy. The absorbed gonadal radiation dose ranged from 15 to 157.5 rad. At 10-24 months after radiotherapy, serum hormone levels, sperm analysis, sperm penetration into zona-free hamster ova (HOP-test) and lymphocyte chromosome abnormalities were evaluated. Two patients were azoospermic with elevated serum levels of LH and FSH. The remaining six patients had slightly decreased (n = 3) or normal (n = 3) seminal parameters. Their HOP rates were within the normal range. A low incidence of polyspermy (i.e. only one penetrating sperm per ovum) was found in the patients, suggesting low penetrability of motile sperm. A highly significant correlation was found between sperm count or sperm penetrability and time post-irradiation. The results indicate that restitution of testicular function is time-dependent.     

Immune hierarchy among HIV‐1 CD8+ T cell epitopes delivered by dendritic cells depends on MHC‐I binding irrespective of mode of loading and immunization in HLA‐A*0201 mice

Recent human immunodeficiency virus type 1 (HIV‐1) vaccination strategies aim at targeting a broad range of cytotoxic T lymphocyte (CTL) epitopes from different HIV‐1 proteins by immunization with multiple CTL epitopes simultaneously. However, this may establish an immune hierarchical response, where the immune system responds to only a small number of the epitopes administered. To evaluate the feasibility of such vaccine strategies, we used the human leukocyte antigen (HLA)‐A*0201 transgenic (tg) HHD murine in vivo model and immunized with dendritic cells pulsed with seven HIV‐1‐derived HLA‐A*0201 binding CTL epitopes. The seven peptides were simultaneously presented on the same dendritic cell (DC) or on separate DCs before immunization to one or different lymphoid compartments. Data from this study showed that the T‐cell response, as measured by cytolytic activity and γ‐interferon (IFN‐γ)‐producing CD8⁺ T cells, mainly focused on two of seven administered epitopes. The magnitude of individual T‐cell responses induced by immunization with multiple peptides correlated with their individual immunogenicity that depended on major histocompatibility class I binding and was not influenced by mode of loading or mode of immunization. These findings may have implications for the design of vaccines based on DCs when using multiple epitopes simultaneously.     

Fasciola hepatica: comparison of immature and mature immunoreactive glycoproteins

A comparison of the 35S-methionine metabolically labelled immunoreactive glycoproteins of immature and mature F. hepatica was carried out by one-and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Sera of rabbits infected for 3 weeks reacted much more strongly with glycoproteins of immature flukes than with glycoproteins of mature flukes as compared to sera of rabbits infected for 9 weeks. Several of the immunoreactive glycoproteins were also released by immature F. hepatica into the culture medium. At least one was a component of the T1 type granules. Analysis of the in vitro translation products of mature F. hepatica indicated that the initial humoral immune response of rabbit hosts may be directed against carbohydrate moieties.     

Lifetime costs of cerebral palsy

This study quantified the lifetime costs of cerebral palsy (CP) in a register-based setting. It was the first study outside the US to assess the lifetime costs of CP. The lifetime costs attributable to CP were divided into three categories: health care costs, productivity costs, and social costs. The population analysed was retrieved from the Danish Cerebral Palsy Register, which covers the eastern part of the country and has registered about half of the Danish population of individuals with CP since 1950. For this study we analysed 2367 individuals with CP, who were born in 1930 to 2000 and were alive in 2000. The prevalence of CP in eastern Denmark was approximately 1.7 per 1000. Information on productivity and the use of health care was retrieved from registers. The lifetime cost of CP was about €860 000 for men and about €800 000 for women. The largest component was social care costs, particularly during childhood. A sensitivity analysis found that alterations in social care costs had a small effect, whereas lowering the discount rate from 5 to 3 per cent markedly increased total lifetime costs. Discounting decreases the value of costs in the future compared with the present. The high social care costs and productivity costs associated with CP point to a potential gain from labour market interventions that benefit individuals with CP.