Neuropathophysiological potential of Guillain-Barré syndrome anti-ganglioside-complex antibodies at mouse motor nerve terminals

Objectives:  Anti-ganglioside antibodies are present in approximately half of Guillain–Barré syndrome (GBS) patients. Recently, it has been shown that a considerable proportion of these patients has serum antibodies against antigenic epitopes formed by a complex of two different gangliosides. However, direct experimental evidence for neuropathogenicity of this special category of antibodies is currently lacking. Here, we explored a series of GBS and GBS-variant sera with anti-ganglioside-complex antibodies for their ability to induce complement-dependent deleterious effects at the living neuronal membrane. Methods:  The neuropathophysiological potential of 31 GBS sera containing either anti-GM1/GD1a- or anti-GM1/GQ1b-ganglioside-complex antibodies was studied at motor nerve terminal presynaptic membranes in the mouse phrenic nerve/diaphragm muscle ex vivo experimental model. With electrophysiological measurements and confocal fluorescence microscopy, we assessed and quantified the damaging effect on neuronal membranes by anti-ganglioside-complex antibodies. Results:  We show that anti-GM1/GD1a- and anti-GM1/GQ1b-ganglioside-complex positive sera can induce complement-mediated functional and morphological injury at mouse motor nerve terminals ex vivo. Of the 31 investigated anti-ganglioside-complex patient sera, 17 sera induced increases in miniature end-plate potential frequency in this experimental model, mostly associated with muscle fibre twitches. Variability in potency was observed, with the anti-GM1/GD1a-complex sera inducing the most outspoken effects.<b></b> Conclusions:  The present study shows the presence of ganglioside-complexes as available antigens in living neuronal membranes and supplies proof-of-principle that anti-ganglioside-complex antibodies in sera from GBS patients can induce complement-mediated damage. This strongly supports the hypothesis that autoimmune targeting of ganglioside-complexes is of pathogenic relevance in a proportion of GBS patients

Determination of Dry Rubber Content of Hevea Latex by Microwave Technique

The measurement of the dry rubber content of the fresh hevea latex by microwave technique is described. In this technique the attenuation of microwave by latex is measured at 10.7 GHz and is then calibrated against the standard laboratory method. Compared with the standard method this instrument is able to reduce the measuring time 8 - 16 hours to three minutes. The correlation coefficient between the DRC determined using this instrument and the standard laboratory method is 0.998 and the standard deviation is less than 0.7%. The reproducibility is at a level of 0.8% unit DRC

Physicalism, Mind, and the Ontology of Properties

In this thesis, I will try to find out how we can accommodate human mind in a physical world. What is significant in my attempt is that I try to approach this problem with a prospect that the theory of mental causation and consciousness will be subsumed under the general theory of properties. With this general orientation, I will do the following three things in this thesis: (1) I will trace and develop the theories of mental causation and consciousness that have been conducted in the philosophy of mind. (2) I will trace and develop the general theories of properties that have been conducted in analytic metaphysics. (3) I will try to show that there is a prospect of combining the theory of mental causation and consciousness with the general theory of properties (or rather subsume the former under the latter). In Chapter 2, I will clarify what physicalism should be. I formulate a minimal version of physicalism. The reason why I take physicalism is also stated. In Chapter 3, I survey the history of non-reductive physicalism, and examine a version of non-reductive physicalism, Anomalous Monism. I will show that Anomalous Monism cannot explain the causal efficacy of mental properties. In Chapter 4, I will examine Jaegwon Kim’s attack on non-reductive physicalism – the causal exclusion problem. I will survey several defences from non-reductive physicalist camp and show that none of them is successful. In Chapter 5, I will examine Kim’s solution to the causal exclusion problem. After I defend Kim’s position from possible objections, I will make clear some consequences of Kim’s position. These chapters are devoted to setting the background for discussing mental causation. Chapter 6, 7, 8, and 9 compose a main part of the thesis. Chapter 6 and Chapter 7 are devoted to the ontology of properties. In these chapters, I will try to formulate and defend a Causal Trope Theory of Properties, which is a causal theory of properties combined with a trope theory. Chapter 6 starts with the examination of John Heil’s view on the ontology of properties and objects. I will then expound my own view on properties and compare it with Heil’s view. After that, I will try to defend the Causal Trope Theory against a rival theory, Humean Theory. In Chapter 7, I will defend my own view (a version of a dispositionalist view) from a typical and influential categoricalist view on properties – Prior, Pargetter, and Jackson’s view. I will also attack the categoricalist view. After I set the background for the mental causation problem and the general theory of properties, I will go on to apply these results to the mental causation problem. In Chapter 8, I will show how David Robb’s argument brings in new aspects of the problem. I will show that Robb’s view has a similar consequence as Kim’s but it gives us a more precise ontological picture. In Chapter 9, I will examine Shoemaker’s view on mental causation. I will show that Shoemaker’s view is the most prospective and successful option so far. In Chapter 10, I will survey the main theories of consciousness (qualia) and intentionality. After I explain why consciousness (or qualia) is a serious problem for physicalists, I try to defend the representation theory of consciousness. I will show that if we can explain consciousness by intentionality, and explain intentionality in a physicalistic framework, then we can understand consciousness in a physicalistic framework. I also focus on the normativity character of intentionality and try to defend a teleological approach to intentionality. Finally, in Chapter 11, I will show how the problem of consciousness (qualia) could be viewed as some versions of the problem concerning the general theory of properties. I will show that which view in the general theory of properties we take has some effects on which view in the theory of qualia we should take. It will be shown that the view about the theory of properties which I take in Chapter 6 and Chapter 7 and the view in the theory of consciousness (the representation theory of consciousness) which I take in Chapter 10 are good combination, and that I have good reason to support the representation theory of consciousness discussed in Chapter 10. In the appendix, I will, quite briefly, consider another problem of mental causation, the problem of the extrinsicness of mental properties. I will show why this problem is not a problem for physicalism alone and suggest a possible way to solve it