Morphological Studies of the Immune Response to Vasectomy

1. The morphological changes in the epididymis, testes, and spleen, were studied at seven postoperative periods (6 wks and 4, 6, 9, 12, 15, and 18 mos.) after unilateral (left) vasectomy or sham operation, in a series of 72 mature Albino rats

Theory of Spin Relaxation in Two-Electron Lateral Coupled Si/SiGe Quantum Dots

Highly accurate numerical results of phonon-induced two-electron spin relaxation in silicon double quantum dots are presented. The relaxation, enabled by spin-orbit coupling and the nuclei of $^{29}$Si (natural or purified abundance), are investigated for experimentally relevant parameters, the interdot coupling, the magnetic field magnitude and orientation, and the detuning. We calculate relaxation rates for zero and finite temperatures (100 mK), concluding that our findings for zero temperature remain qualitatively valid also for 100 mK. We confirm the same anisotropic switch of the axis of prolonged spin lifetime with varying detuning as recently predicted in GaAs. Conditions for possibly hyperfine-dominated relaxation are much more stringent in Si than in GaAs. For experimentally relevant regimes, the spin-orbit coupling, although weak, is the dominant contribution, yielding anisotropic relaxation rates of at least two order of magnitude lower than in GaAs.Comment: 11 pages, 10 figure

Characterization of fluids involved in the Gneiss-Charnockite transformation in Southern Kerala (India)

The characterization of fluids involved in the gneiss-charnockite transformation in southern Kerala are discussed. Using a variety of techniques, including microthermometry, Raman laser probe analysis, and mass spectrometry, it was concluded that the CO2-rich, N2-bearing metamorphic fluids in these rocks were internally-derived rather than having been introduced by CO2-streaming

Kabbaldurga-type charnockitization: A local phenomenon in the granulite to amphibolite grade transition zone

In the deeply eroded Precambrian crust of South India and Sri Lanka, a series of spectacular exposures shows progressive development of coarse-grained charnockite through dehydration of amphibolite grade gneisses in different arrested stages. At Kabbaldurga, charnockitization of Archaean grey biotite-hornblende gneisses occurred about 2.5 Ga ago and evidently was induced by the influx of external carbonic fluids along a system of ductile shears and the foliation planes. The results of oxygen isotope thermometry and of geothermobarometry in adjacent areas indicate a P-T regime of 700 to 750 C and 5 to 7 kb. The decrease of water activity in the fluid infiltrated zones caused an almost complete breakdown of hornblende and biotite and the new growth of hypersthene. Detailed petrographic and geochemical studies revealed marked changes in mineralogy and chemistry from granodioritic to granitic which document the metasomatic nature of the process

Autologous point‐of‐care stromal vascular fraction transplantation in dogs with advanced osteoarthritis of the knee and hip joints

Objective The aim of the study was to assess lameness in dogs with advanced osteoarthritis of the hip and knee joints after a single autologous point-of-care transplantation of the Stromal Vascular Fraction (SVF) into the affected joint. Materials and methods During a minilaparotomy, 10 g of falciform fat was removed from each patient for each joint to be treated. A modern and time-saving procedure (ARC TM System, InGeneron GmbH, Houston, USA) was used for the in-house preparation of the SVF, so that the isolated cells could be applied to the respective joint within 2 h after fat removal. In total, five knee joints of five patients and seven hip joints of four patients were treated. Results Improvement in lameness according to owner questionnaires was seen in 3 of 5 patients with knee joint arthritis and 2 of 4 patients with hip joint arthritis. Based on gait analysis, only one dog with gonarthrosis and one dog with coxarthrosis showed improvement up to a maximum of 3 months after surgery. Conclusion This is the first case series on the treatment of osteoarthrosis of the knee or hip joint using point-of-care transplantation of the SVF. In individual cases, this method may represent a therapeutic approach for the treatment in dogs with advanced cox- or gonarthrosis, although only a short-term effect can be expected, which calls into question the effort and costs involved

Linking cytoarchitecture to metabolism: sarcolemma-associated plectin affects glucose uptake by destabilizing microtubule networks in mdx myofibers

BACKGROUND: Duchenne muscular dystrophy (DMD) is one of the most frequent forms of muscular disorders. It is caused by the absence of dystrophin, a core component of the sarcolemma-associated junctional complex that links the cytoskeleton to the extracellular matrix. We showed previously that plectin 1f (P1f), one of the major muscle-expressed isoforms of the cytoskeletal linker protein plectin, accumulates at the sarcolemma of DMD patients as well as of mdx mice, a widely studied animal model for DMD.Based on plectin's dual role as structural protein and scaffolding platform for signaling molecules, we speculated that the dystrophic phenotype observed after loss of dystrophin was caused, at least to some extent, by excess plectin. Thus, we hypothesized that elimination of plectin expression in mdx skeletal muscle, while probably resulting in an overall more severe phenotype, may lead to a partial phenotype rescue. In particular, we wanted to assess whether excess sarcolemmal plectin contributes to the dysregulation of sugar metabolism in mdx myofibers. METHODS: We generated plectin/dystrophin double deficient (dKO) mice by breeding mdx with conditional striated muscle-restricted plectin knockout (cKO) mice. The phenotype of these mice was comparatively analyzed with that of mdx, cKO, and wild-type mice, focusing on structural integrity and dysregulation of glucose metabolism. RESULTS: We show that the accumulation of plectin at the sarcolemma of mdx muscle fibers hardly compensated for their loss of structural integrity. Instead, it led to an additional metabolic deficit by impairing glucose uptake. While dKO mice suffered from an overall more severe form of muscular dystrophy compared to mdx or plectin-deficient mice, sarcolemmal integrity as well as glucose uptake of their myofibers were restored to normal levels upon ablation of plectin. Furthermore, microtubule (MT) networks in intact dKO myofibers, including subsarcolemmal areas, were found to be more robust than those in mdx mice. Finally, myotubes differentiated from P1f-overexpressing myoblasts showed an impairment of glucose transporter 4 translocation and a destabilization of MT networks. CONCLUSIONS: Based on these results we propose that sarcolemma-associated plectin acts as an antagonist of MT network formation in myofibers, thereby hindering vesicle-mediated (MT-dependent) transport of glucose transporter 4. This novel role of plectin throws a bridge between extra-sarcomeric cytoarchitecture and metabolism of muscle fibers. Our study thus provides new insights into pathomechanisms of plectinopathies and muscular dystrophies in general

Germline mutations in the oncogene EZH2 cause Weaver syndrome and increased human height.

The biological processes controlling human growth are diverse, complex and poorly understood. Genetic factors are important and human height has been shown to be a highly polygenic trait to which common and rare genetic variation contributes. Weaver syndrome is a human overgrowth condition characterised by tall stature, dysmorphic facial features, learning disability and variable additional features. We performed exome sequencing in four individuals with Weaver syndrome, identifying a mutation in the histone methyltransferase, EZH2, in each case. Sequencing of EZH2 in additional individuals with overgrowth identified a further 15 mutations. The EZH2 mutation spectrum in Weaver syndrome shows considerable overlap with the inactivating somatic EZH2 mutations recently reported in myeloid malignancies. Our data establish EZH2 mutations as the cause of Weaver syndrome and provide further links between histone modifications and regulation of human growth

Catanionic micelles as a model to mimic biological membranes in the presence of anesthetic alcohols

We show here the influence of n-alcohols (C2OH-C8OH) on the solubility behavior of cationic-anionic surfactant mixtures, so-called “catanionics”.Westudied catanionics of different compositions composed of sodium dodecyl sulfate (SDS)/cetyltrimethylammonium bromide (CTAB) and sodium dodecanoate (SDod)/CTAB mixtures. Interestingly, with a molar excess of SDS, long chain n-alcohols (C4OH-C8OH) significantly depress the solubility temperature of the SDS+CTAB catanionic and increase the kinetic stability of the solution. The visual observations of solubility temperatures of catanionics were further confirmed by differential scanning calorimetry (DSC) measurements. For the catanionics a multistep solubilization was observed by DSC, for which the sulfate headgroup is responsible. This was probed by replacing SDS by SDod. A remarkable analogy was found between the influence of the alcohols on the solubility patterns of the catanionic mixtures and on the anesthesia of tadpoles. Possible reasons for this analogy are discussed also in this paper

A Model of Vertical Oligopolistic Competition

This paper develops a model of successive oligopolies with endogenous market entry, allowing for varying degrees of product differentiation and entry costs in both markets. Our analysis shows that the downstream conditions dominate the overall profitability of the two-tier structure while the upstream conditions mainly affect the distribution of profits. We compare the welfare effects of upstream versus downstream deregulation policies and show that the impact of deregulation may be overvalued when ignoring feedback effects from the other market. Furthermore, we analyze how different forms of vertical restraints influence the endogenous market structure and show when they are welfare enhancing

The possible existence of Hs in nature from a geochemical point of view

A hypothesis of the existence of a long-lived isotope 271Hs in natural molybdenites and osmirides is considered from a geochemical point of view. It is shown that the presence of Hs in these minerals can be explained only by making an additional ad hoc assumption on the existence of an isobaric pair of 271Bh-271Hs. This assumption could be tested by mass-spectrometric measurements of U, Pb, Kr, Xe, and Zr isotopic shifts.Comment: 5 pages, no figures. Physics of Particles and Nuclei Letters, 2006, Vol. 3, No. 3, pp. 165-168 in pres