Assessment of potential neuropathic changes in cattle after cautery disbudding.

Disbudding of calves is a standard husbandry procedure to reduce the risk of injuries to other cattle and to workers. Whereas acute pain resulting from disbudding has been studied extensively, little is known about chronic pain as a potential long-term consequence. The goal of the present study was to investigate possible morphological changes in the cornual nerve as a function of disbudding. Samples were collected from 17 randomly selected bulls and from 21 calves from a prospective clinical study. Among the calves, 13 were disbudded and 8 were sham-disbudded. Out of the disbudded calves, 4 showed signs of chronic pain. In all the animals, the infraorbital nerve was used as a methodological check. Morphological analysis included measuring minimal diameters of the axons present in both the cornual and infraorbital nerves. Sympathetic fibers were identified as based on the presence of Tyroxine hydroxylase (TH). TH-negative fibers were considered afferents. Trigeminal ganglia from the calves were immunostained for glial fibrillary acidic protein (GFAP) and Activating transcription factor 3 (ATF3). R. cornualis and N. infraorbitalis differed in terms of axon diameters and proportion of TH-positive fibers. Weak evidence (p > .091) of a difference in axon diameters between control and disbudded calves was found in R. cornualis, but the proportion of TH-positive fibers was alike in both groups. Average glial envelope and the percentages of ATF3-positive neurons revealed no difference between calves with and without signs of pain. Thus, available evidence is insufficient to support neuropathic changes as a result of disbudding in calves.

Vesicle solubilization by bile salts: comparison of macroscopic theory and simulation.

Lipid metabolism is accompanied by the solubilization of lipid bilayer membranes by bile salts. We use Brownian dynamics simulations to study the solubilization of model membranes and vesicles by sodium cholate. The solubilization pathways of small and large vesicles are found to be different. Both results for small and large vesicles can be compared with predictions of a macroscopic theoretical description. The line tension of bilayer edges is an important parameter in the solubilization process. We propose a simple method to determine the line tension by analyzing the shape fluctuations of planar membrane patches. Macroscopic mechanical models provide a reasonable explanation for processes observed when a spherical vesicle consisting of lipids and adsorbed bile salt molecules is transformed into mixed lipid-bile salt micelles.

Lattice energies for crystals of colloidal spheroids.

Attractive interactions between adjacent spheroids and excluded volume effects favor their parallel alignment. Parallel spheroids can be arranged into a variety of densely packed two-dimensional and three-dimensional lattice configurations. All of these configurations turn out to have the same lattice energy. A similar degeneracy is also found for several classes of lattices with lower volume density. We discuss implications of this degeneracy for the stability of colloidal crystals consisting of spheroids.

Interactions between spheroidal colloidal particles.

Using Derjaguin's approximation, we have evaluated the interaction energy associated with van der Waals, electrostatic, depletion, and capillary forces between colloidal spheroids. If the interaction range between spheroids is distinctly smaller than the lengths of their principal axes, then simple pair potentials that depend on particle distance and orientation can be derived. Attractive interactions between adjacent spheroids favor their parallel alignment. Parallel spheroids can be arranged into a variety of densely packed configurations. All of these configurations turn out to have the same lattice energy. We discuss the implications of this degeneracy with respect to the stability of photonic crystals consisting of spheroids.

Depletion force between anisometric colloidal particles.

A simple mathematical model for the depletion force between two arbitrarily shaped large convex colloidal particles immersed in a suspension of small spherical particles is proposed. Using differential geometry, the interaction potential is expressed in terms of the mean and Gaussian curvature of the particle surfaces. The accuracy of theoretical results is tested by Monte Carlo simulations for parallel and nonparallel circular cylinders. The agreement between theoretical results and simulated data is very good if the density of the depletion agent is not too high.

Monte Carlo study of the self-assembly of achiral bolaform amphiphiles into helical nanofibers.

It is shown by coarse-grained off-lattice Monte Carlo simulations that a geometrically induced frustration of the parallel arrangement of rigid achiral bolaform amphiphiles can cause chirality in self-assembled nanostructures. The amphiphilic molecules are represented as rigid linear chains of 8 equally sized hydrophobic spheres (tail) and a hydrophilic sphere (head) at each end. The hydrophilic and hydrophobic spheres differ in size. A very simple interaction scheme consisting of only hard-core repulsion between all spheres and square-well attraction between hydrophobic spheres is sufficient for self-assembly into helical fibers for molecules with head/tail diameter ratios ranging from 1.3 to 1.8.

Monte Carlo simulations of small vesicles under osmotic pressure.

A simple model for amphiphilic molecules is sufficient to predict self-assembly into spherical vesicles. The model is also useful to study the influence of osmotic pressure on the shape of vesicles, which serve as carriers in biological cells. The stability of small vesicles subjected to relatively high osmotic pressures is demonstrated. Fluctuations of small vesicles under osmotic stress are found to be in semiquantitative agreement with a macroscopic description. Small deviations between simulated results for vesicle fluctuations and macroscopic elasticity theory could result from the relative large membrane thickness in comparison to the vesicle radius. The simulations demonstrate that an osmotic pressure exerted by solute molecules outside a spherical vesicle can cause a shape transition, in agreement with results based on the elasticity theory of membranes.

CSF proteome analysis in clinically isolated syndrome (CIS): candidate markers for conversion to definite multiple sclerosis.

Cerebrospinal fluid (CSF) is a promising source of biomarkers in clinically isolated syndrome (CIS), which frequently presents as a first episode of multiple sclerosis (MS). Using the two-dimensional difference in gel electrophoresis (2-D DIGE), we compared CSF samples from patients with CIS that remained CIS (CIS-CIS, n=8) over a follow-up time of 2 years and from patients with CIS that developed definite MS of the relapsing-remitting subtype (CIS-RRMS, n=8) over the same period. Protein spots that showed significant differences between patients and controls were selected for further analysis by MALDI-TOF mass spectrometry. For validation of identified spots ELISA experiments were performed. We identified one protein that was upregulated in CIS-RRMS (serin peptidase inhibitor) and eight proteins (alpha-1-B-glycoprotein, Fetuin-A, apolipoprotein A4, haptoglobin, human Zinc-alpha-2-glycoprotein (ZAG), Retinol-binding protein, superoxid dismutase 1, transferrin) that were down-regulated in CIS-RRMS vs. CIS-CIS. For Fetuin-A, our findings could be confirmed by ELISA. The pathophysiological role as well as clinical relevance of these candidate proteins in CIS remains to be further clarified by future studies.

Monte Carlo simulation of surfactant adsorption on hydrophilic surfaces.

Monte Carlo simulations have been carried out to study the adsorption behavior of small flexible amphiphilic molecules on solid surfaces from aqueous solutions. A simple coarse-grained solvent-free off-lattice model, with a square-well pair potential and hard core excluded volume effect, has been used. Adsorption isotherms for weakly and strongly hydrophilic homogeneous surfaces have been determined. The adsorbed layer displays a coexistence region with an upper critical point. Below the critical temperature a densely packed patch coexists with a two-dimensional gas-analogous phase. Above the critical temperature, a percolating network forms at higher surfactant concentrations. Depending on the ratio between the strength of the hydrophobic effect and the adsorption energy, a large variety of associates has been observed. Monolayers, bilayers, admicelles, small clusters, and percolating networks as typical associate structures have been found. In the four-region model, which is extended by the coexistence region, a characteristic adsorbed layer structure for each region can be detected. Intermediate structure types have been produced by variation of the adsorption energy.

[Diagnosis and differential diagnosis of granulomatous myositis]. / Diagnose und Differenzialdiagnose der granulomatösen Myositis.

Granulomatous myositis is a rare neuromuscular disorder histologically characterized by the development of endomyseal and/or perimyseal granulomas. Clinical hallmarks are generalized muscle weakness, myalgias, and bulbar symptoms. The association of granulomatous myositis with sarcoidosis is well known; less recognized is the association with several infectious diseases, inflammatory bowel diseases, malignancy, thymoma, graft-vs-host disease, and myasthenia gravis. In absence of sarcoidosis or other underlying disorders, the diagnosis of isolated or primary granulomatous myositis must be considered. Therapeutic strategies focus on immunosuppression, whereas the therapy response is unpredictable. Here we discuss the clinical features, diagnosis, and differential diagnosis and therapeutic strategies of primary and secondary granulomatous myositis.

Monte carlo simulations of self-assembled surfactant aggregates.

Monte Carlo simulations provide some insight into the self-assembly of amphiphiles in aqueous environment. A rather simple solvent-free model, with only two adjustable parameters in the effective pair potential, allows one to describe the formation of micelles, stable curved membranes, and metastable vesicles. Characteristic features of the self-assembled aggregates, such as the distribution of the micelle size and the value of the curvature elastic constant for membranes, can be obtained from simulated data. The capability of the simple approach was demonstrated for a surfactant model with three spherical segments. The extension of the simulation to molecules with more segments and branched amphiphiles is straightforward.

Monte Carlo study of surfactant adsorption on heterogeneous solid surfaces.

The equilibrium between free surfactant molecules in aqueous solution and adsorbed layers on structured solid surfaces is investigated by lattice Monte Carlo simulation. The solid surfaces are composed of hydrophilic and hydrophobic surface regions. The structures of the surfactant adsorbate above isolated surface domains and domains arranged in a checkerboard-like pattern are characterized. At the domain boundary, the adsorption layers display a different behavior for hydrophilic and hydrophobic surface domains. For the checkerboard-like surfaces, additional adsorption takes place at the boundaries between surface domains.

Adhesion force of a wedge.

The macroscopic theory of capillarity is usually applied to evaluate the adhesion forces produced by fluid bridges between solid particles. A refined mesoscopic description incorporates the disjoining pressure, which results from the long range forces between the fluid and the solid substrates. In the case of simple nonpolar fluids the influence of the disjoining pressure on adhesion is expected to be negligibly small. Water bridges, however, sometimes have very large disjoining pressures on various substrates. Then mesoscopic theory leads to pull-off forces which differ from the predictions of the macroscopic approach.

Autoantibodies to adrenal medullary and thyroid calcitonin cells in type I diabetes mellitus--a prospective study.

Autoantibodies to adrenal medulla that gave a diffuse immunofluorescent staining pattern were detected in 17 out of 107 (16%) patients with newly diagnosed Type I diabetes mellitus, in 13 out of 178 (7%) patients with long lasting disease but in none of 80 mixed control sera tested. The antibodies were of IgG class and 31 of the 33 positive sera also fixed complement. In 32 out of 34 cases, detection of the antibodies was correlated with the presence in the serum of pancreatic islet cell antibodies (ICA). The specificity of adrenal medullary antibodies is distinct from ICA and from C-cell antibodies since their reactivity was not abolished by preabsorption with extracts from human insulinoma or thyroid C-cell carcinoma. The presence in the serum of antibodies to adrenal medulla is not related to a functional defect of the adrenal medulla, but this new specificity indicates a further autoimmune reaction related to the natural history of Type I diabetes.