Blends of Bio-Based Poly(Limonene Carbonate) with Commodity Polymers

In this study, blends of the bio-based poly(limonene carbonate) (PLimC) with different commodity polymers are investigated in order to explore the potential of PLimC toward generating more sustainable polymer materials by reducing the amount of petro- or food-based polymers. PLimC is employed as minority component in the blends. Next to the morphology and thermal properties of the blends the impact of PLimC on the mechanical properties of the matrix polymers is studied. The interplay of incompatibility and zero-shear melt viscosity contrast determines the blend morphology, leading for all blends to a dispersed droplet morphology for PLimC. Blends with polymers of similar structure to PLimC (i.e., aliphatic/aromatic polyester) show the best performance with respect to mechanical properties, whereas blends with polystyrene or poly(methyl methacrylate) are too brittle and polyamide 12 blends show very low elongations at break. In blends with Ecoflex (poly(butylene adipate-co-terephthalate)) and Arnitel EM400 (copoly(ether ester)) with poly(butylene terephthalate) hard and polytetrahydrofuran soft segments) a threefold increase in E-modulus can be achieved, while keeping the elongation at break at reasonable high values of ≈200%, making these blends highly interesting for applications.     

Neuroprotection Mediated by Human Blood Plasma in Mouse Hippocampal Slice Cultures and in Oxidatively Stressed Human Neurons

Neuroprotection from oxidative stress is critical during neuronal development and maintenance but also plays a major role in the pathogenesis and potential treatment of various neurological disorders and neurodegenerative diseases. Emerging evidence in the murine system suggests neuroprotective effects of blood plasma on the aged or diseased brain. However, little is known about plasma-mediated effects on human neurons. In the present study, we demonstrate the neuroprotective effect mediated by human plasma and the most abundant plasma–protein human serum albumin against oxidative stress in glutamatergic neurons differentiated from human neural crest-derived inferior turbinate stem cells. We observed a strong neuroprotective effect of human plasma and human serum albumin against oxidative stress-induced neuronal death on the single cell level, similar to the one mediated by tumor necrosis factor alpha. Moreover, we detected neuroprotection of plasma and human serum albumin against kainic acid-induced excitatory stress in ex vivo cultured mouse hippocampal tissue slices. The present study provides deeper insights into plasma-mediated neuroprotection ultimately resulting in the development of novel therapies for a variety of neurological and, in particular, neurodegenerative diseases.     

Learning to select useful landmarks

To navigate effectively, an autonomous agent must be able to quickly and accurately determine its current location. Given an initial estimate of its position (perhaps based on dead-reckoning) and an image taken of a known environment, our agent first attempts to locate a set of landmarks (real-world objects at known locations), then uses their angular separation to obtain an improved estimate of its current position. Unfortunately, some landmarks may not be visible, or worse, may be confused with other landmarks, resulting in both time wasted in searching for the undetected landmarks, and in further errors in the agent's estimate of its position. To address these problems, we propose a method that uses previous experiences to learn a selection function that, given the set of landmarks that might be visible, returns the subset that can be used to reliably provide an accurate registration of the agent's position. We use statistical techniques to prove that the learned selection function is, with high probability, effectively at a local optimum in the space of such functions. This paper also presents empirical evidence, using real-world data, that demonstrate the effectiveness of our approach.     

Spontaneous orientation of transplanted olfactory glia influences axonal regeneration

Transplanted olfactory ensheathing cells (OECs) have previously been demonstrated to support axonal growth and myelination in the adult rat CNS. Here, the capacity of donor OECs to control the direction of axonal regeneration has been investigated following transplantation, as elongated columns, into the thalamus of adult rats. The OECs formed a 'glial bridge' which extended from the thalamus to the hippocampus. Transplanted OECs rapidly adopted a spindle-shaped morphology which was orientated along the vertical axis of the transplant. Numerous host axons grew into the transplants and followed the highly orientated OEC cell matrix across the choroid fissure. Thus, the spontaneous elongation and orientation of donor OECs may support highly directional host axonal growth across natural barriers within the CNS.     

Coexpression of leptin receptor and preproneuropeptide Y mRNA in arcuate nucleus of mouse hypothalamus

Leptin, the protein product of the adipose tissue-specific ob (obese) gene (1), reduces the body weight, adiposity and food intake of obese ob/ob mice on peripheral or central injection (2, 3, 4). [125I]leptin binding has been detected in mouse choroid plexus (5), from which a leptin receptor gene was expression cloned (5). The gene has at least 6 splice variants (6, 7). Leptin receptor mRNA was localized in the hypothalamus by in situ hybridization being particularly abundantly expressed in the arcuate nucleus (8). There is evidence linking the physiological effects of injected leptin with hypothalamic neuropeptide Y (9, 10) (NPY), which has potent central effects on food intake and energy balance (11), and is also expressed in the arcuate nucleus. Here we report dual in situ hybridization studies for leptin receptor and NPY gene expression in the mouse arcuate nucleus, where the majority of cells examined expressed both genes. This provides the first direct evidence that leptin acts on cells that express NPY mRNA.     

Single-chain immunotoxins targeted to CD40 for the treatment of human B-lineage hematologic malignancies

Immunotoxins, in chemical conjugate form, have shown limited efficacy in clinical trials in patients with hematologic malignancies. Single-chain immunotoxins (SCIT) provide for enhanced therapeutic efficacy over chemical conjugate forms without additional toxicity and thus may result in improved antitumor activity. We have evaluated two SCITs targeted to CD40, a receptor expressed on most B-lineage hematologic malignancies, for the treatment of non-Hodgkin's lymphoma and multiple myeloma. Both SCITs, G28-5 sFv-PE40 and BD1-G28-5 sFv, were highly potent and specifically cytotoxic against non-Hodgkin's lymphoma and multiple myeloma cell lines. G28-5 sFv-PE40 has proven to be efficacious in SCID mice bearing human non-Hodgkin's lymphoma and multiple myeloma xenografts. Antitumor activity has also been noted in preliminary studies using BD1-G28-5 sFv in non-Hodgkin's lymphoma models. The data presented here indicate that these agents should be considered for use in clinical trials in patients with refractive non-Hodgkin's lymphoma, multiple myeloma and other CD40-expressing hematologic malignancies.     

Scar formation and ligament healing

OBJECTIVE: To compare the efficacy of IUI husband in natural versus FSH stimulated cycles. DESIGN: Prospective, controlled study. MATERIALS AND METHODS: IUI were performed in 57 infertile couples with natural cycles, and in 16 under FSH and GnRH stimulation (Short protocol). In stimulated patients also hCG and hydrogesteron were given. Indication in both groups was idiopathic infertility. Duration of infertility and the age were comparable. Semen preparation and ovarian monitoring were the same in 2 groups. RESULTS: Three pregnancies in 57 natural IUI cycles (5.3%) and 5 out of 16 cycles in stimulated women (31.2% per cycle-with one triple pregnancy). CONCLUSION: In couples with idiopathic infertility FSH stimulation significantly increases rate of pregnancy and multiple gestation.     

Long-term T cell memory requires the surface expression of self-peptide/major histocompatibility complex molecules

How memory T cells are maintained in vivo is poorly understood. To address this problem, a male-specific peptide (H-Y) was identified and used to activate female anti-H-Y T cells in vitro. Anti-H-Y T cells survived in vivo for at least 70 days in the absence of antigen. This persistence was not because of the intrinsic ability of memory T cells to survive in vivo. Instead, the survival and function of adoptively transferred memory cells was found to require transporter of antigen protein 1-dependent expression of self-peptide/major histocompatibility complex class I molecules in recipient animals. Therefore, it appears that the level of T cell receptor engagement provided by transporter of antigen protein 1-dependent, self-peptide/major histocompatibility complexes is sufficient to maintain the long-term survival and functional phenotype of memory cells in the absence of persistent antigen. These data suggest that positive selection plays a role not only in T cell development but also in the maintenance of T cell memory.     

Augmentative and alternative communication to support receptive and expressive communication for people with autism

In this article the authors discuss the use of augmentative and alternative communication (AAC) as used to enhance comprehension and expression of people with autism. A theoretical model for AAC assessment and intervention planning is presented. Application of the model is illustrated through a case report of a 6-year-old boy with autism who had severe expressive and receptive language impairments.