Great toe drop following knee ligament reconstruction: A case report.

A 17-year-old male post anterior cruciate ligament reconstruction complained of the inability to extend his great toe immediately following surgery. Neurological injuries following knee arthroscopy have been reported to occur between 0.6%-2.

Electron density distributions calculated for the nickel sulfides millerite, vaesite, and heazlewoodite and nickel metal: a case for the importance of ni-ni bond paths for electron transport.

Bond paths and the bond critical point properties (the electron density (rho) and the Hessian of rho at the bond critical points (bcp's)) have been calculated for the bonded interactions comprising the nickel sulfide minerals millerite, NiS, vaesite, NiS(2), and heazlewoodite, Ni(3)S(2), and Ni metal. The experimental Ni-S bond lengths decrease linearly as the magnitudes of the properties each increases in value. Bond paths exist between the Ni atoms in heazlewoodite and millerite for the Ni-Ni separations that match the shortest separation in Ni metal, an indicator that the Ni atoms are bonded.

Crystal structure of a high-pressure/high-temperature phase of alumina by in situ X-ray diffraction.

Alumina (alpha-Al(2)O(3)) has been widely used as a pressure calibrant in static high-pressure experiments and as a window material in dynamic shock-wave experiments; it is also a model material in ceramic science. So understanding its high-pressure stability and physical properties is crucial for interpreting such experimental data, and for testing theoretical calculations. Here we report an in situ X-ray diffraction study of alumina (doped with Cr(3+)) up to 136 GPa and 2,350 K.

Survey of gross anatomy, microscopic anatomy, neuroscience, and embryology courses in medical school curricula in the United States.

Directors of courses in the basic anatomical sciences in allopathic and osteopathic medical schools in the United States were surveyed regarding the present composition of their courses. Results indicate the majority of gross anatomy courses are in the range of 126 to 200 total course hours, and that laboratory dissection is a key component of these courses. The majority of microscopic anatomy courses are in the range of 61 to 100 total course hours, generally divided equally between lecture and laboratory components.

Anatomical interactions between the central amygdaloid nucleus and the hypothalamic paraventricular nucleus of the rat: a dual tract-tracing analysis.

Axonal connections between the amygdala and the hypothalamic paraventricular nucleus were examined by combined anterograde-retrograde tract tracing. Iontophoretic injections of the retrograde tracer Fluorogold were placed in the paraventricular nucleus, and the anterograde tracer PHA-L in the ipsilateral central or medial amygdaloid nuclei. Single and double-label immunohistochemistry were used to detect tracers.

Activated macrophage/microglial cells can promote the regeneration of sensory axons into the injured spinal cord.

A prominent role for phagocytic cells in the regenerative response to CNS or PNS injury has been suggested by numerous studies. In the present work we tested whether increasing the presence of phagocytic cells at a spinal cord injury site could enhance the regeneration of sensory axons from cut dorsal roots. Nitrocellulose membranes treated with TGF-beta or coated with microglial cells were cotransplanted with fetal spinal cord tissue into an injured adult rat spinal cord.

Hypothalamo-Pituitary-Adrenocortical Regulation Following Lesions of the Central Nucleus of the Amygdala.

Previous reports indicate that the central nucleus of the amygdala (CeA) stimulates adrenocorticotropin and corticosterone secretion, suggesting a role for this region in central hypothalamo-pituitary-adrenocortical (HPA) stress regulation. To evaluate this hypothesis, this study assessed the impact of CeA lesion on the response of hypophysiotrophic paraventricular nucleus (PVN) neurons to acute restraint and chronic unpredictable stress exposure. In contrast to previous reports, CeA lesions did not affect corticosterone or ACTH secretion induced by acute stress.

Neuronal circuit regulation of the hypothalamo-pituitary-adrenocortical stress axis.

The hypothalamo-pituitary-adrenocortical (HPA) axis is the primary modulator of the adrenal glucocorticoid stress response. Activation of this axis occurs by way of a discrete set of neurons in the hypothalamic paraventricular nucleus (PVN). The PVN neuron appears to be affected by multiple sources, including (1) brainstem aminergic/peptidergic afferents; (2) blood-borne information; (3) indirect input from limbic system-associated regions, including the prefrontal cortex, hippocampus, and amygdala; and (4) local-circuit interactions with the preoptic-hypothalamic continuum.

Structure and Density of FeS at High Pressure and High Temperature and the Internal Structure of Mars.

In situ x-ray diffraction measurements revealed that FeS, a possible core material for the terrestrial planets, transforms to a hexagonal NiAs superstructure with axial ratio (c/a) close to the ideal close-packing value of 1.63 at high pressure and high temperature. The high-pressure-temperature phase has shorter Fe-Fe distances than the low-pressure phase.

Regulatory changes in neuroendocrine stress-integrative circuitry produced by a variable stress paradigm.

Stress represents a complex stimulus to neuroendocrine systems regulating homeostasis. By and large, stress effects are mediated by stress-integrative corticotropin-releasing hormone (CRH) neurons present in the medial parvocellular division of the hypothalamic paraventricular nucleus (PVN). These neurons summate a large variety of neuronal and hormonal signals to eventually yield a physiologically meaningful level of circulating glucocorticoids.

New Opportunities in Synchrotron X-ray Crystallography.

Several high-intensity synchrotron x-ray sources have been constructed over the past few years in the United States, West Germany, Great Britain, Japan, France, Italy, and the Soviet Union. Crystallographers have begun to use these facilities for experiments that take advantage of the characteristics of synchrotron radiation, namely, a broad distribution of wavelengths, high intensity, low divergence, strong polarization, and a pulsed time structure. In addition to more familiar diffraction experiments on single crystals and powdered samples, new types of crystallographic studies, for example, energy-dispersive and surface diffraction studies, have progressed rapidly with more general accessibility of synchrotron sources.

Garnet-like structures of high-pressure cadmium germanate and calcium germanate.

Crystals of CdGeO(3) grown at a pressure of 65 kilobars are tetragonal and have an ordered, garnet-like crystal structure with cadmium occupying the dodecahedral and octahedral sites, and germanium the octahedral and tetrahedral sites. The crystal structure (a = 12.406 +/- 1 angstroms, c = 12.

Germanium and Silicon Disulfides: Structure and Synthesis.

Crystal structures of the tetragonal forms of germanium and silicon disulfide are similar and consist of (SiS(4))(4-) and (GeS(4))(4-) tetrahedra which share vertices to form three-dimensional networks. These tetragonal materials, synthesized at high pressure and temperature, are different from the previously known germanium and silicon disulfides.

GERMANIUM AND SILICON DISULFIDES: STRUCTURE AND SYNTHESIS.

A series of carbon-14 measurements of 18th- and 19-century wood revealed an excellent correlation between the variations in carbon-14 content and average sunspot activity. It seems probable, therefore, that the predominant cause of the short-term fluctuations in carbon-14 activity is the variability of solar activity.