Radiological findings in the diagnosis of genitourinary candidiasis.

The presence of fungus balls within the collecting system is an important clue to the radiological diagnosis of genitourinary candidiasis. In this report, an 8-month-old infant with this opportunistic infection is described. Emphasis is placed on the radiological findings of renal candidiasis, including previously unreported MR appearances. Sonographic and Doppler findings of accompanying Candida epididymitis are also described.

The central nucleus of the inferior colliculus in rat: a Golgi and computer reconstruction study of neuronal and laminar structure.

The cellular basis for the laminar structure of the central nucleus of the inferior colliculus has been investigated by computer-assisted 3-D reconstruction of Golgi impregnated dendritic arbors, sampled from serial sections of resin embedded material of adult rat. Two types of flattened neurone, defined here as flat (F) and less flat (LF), are described as contributing to the pattern. The dendritic arbors of F neurones had a smaller absolute thickness (mean about 50 microns) and a denser arbor. They were strikingly parallel regionally and formed laminae mostly one cell thick. The laminae appeared to be separated by interlaminar compartments populated by the LF neurones. The arbors of the latter were thicker (mean about 100 microns) and less dense than those of the F neurones. The different density of the two types may, at least in part, be responsible for the corresponding difference in density of oriented dendrites within the laminae and interlaminar compartments. The orientation planes of F and LF arbors were roughly similar, but a consistent, slight difference in orientation between F and LF arbors is not excluded. Most of the F and LF arbors were elongated in parallel with the ventrolaterally to dorsomedially oriented long axis of the laminae. A few were instead oriented rostrocaudally or in intermediate directions. The interlaminar compartments appeared less distinct in the low than in the high frequency region. The latter region also differed from the former by having F neurones with a higher number of intermediate and terminal segments and a denser arbor. It is discussed whether the observed F and LF cells constitute two distinct cell types or are varieties of one type of neurone, with the morphological differences reflecting differences in location. Further characterization of the neurones on histochemical, hodological, and other criteria is required to settle this question.

Computer methods in neuroanatomy: determining mutual orientation of whole neuronal arbors.

In most neurons orientation can be recognized because their arbors are more or less polarized and/or flattened. These are morphological characteristics of great functional importance. This paper deals with three-dimensional display and mathematical definition of orientation planes and vectors in whole arbors. An orientation plane can be derived from the flattest rectangular prism with which it is possible to enclose the arbor, or may be found by best-fit least square determination (based on all digitized points of the arbor). Both approaches allow description and comparison, in quantitative terms, of the orientation of neurons under various normal, pathological or experimental conditions.

Spatial segregation between populations of ponto-cerebellar neurons: statistical analysis of multivariate spatial interactions.

This study applies terms and methods for describing spatial interactions between multivariate spatial point patterns, which are, to our knowledge, new in neurobiology. We consider two categories of points, type 1 and 2, distributed within a certain reference volume (such as a nucleus of the brainstem or a cortical area). The points may, for example, represent different categories of labelled cells or axonal fields of termination. We say that there is spatial neutrality between points of type 1 and 2 if the types are signed by random labelling. If a mechanism drives the two point categories together, we say that the point patterns are positively associated. Conversely, if a mechanism drives type 1 and 2 points apart, we say that they are segregated. By comparing two cumulative distribution functions of distances between points, we can distinguish neutrality, positive association, and segregation. One function, H12(t), is the cumulative distribution function of the distance t between a pair of randomly selected points of type 1 and 2. The other, H00(t), is the corresponding function for a pair of points randomly selected without reference to type. Plots of the estimated difference between these two functions give an indication of positive association, neutrality, or segregation. A statistical test, based on simulations of random (neutral) distributions, can be used to see whether deviations from neutrality are significant. We apply the analysis described above to a major pathway of the brain, namely the ponto-cerebellar projection. Different types of cells in the pontine nuclei are retrogradely labelled with the fluorescent tracers Rhodamine-B-isothiocyanate, Fluoro-Gold, and Fast Blue. The tracers are injected in adjacent or more distant folia of the cerebellar paraflocculus. The location of the somata of labelled cells are recorded and the total distribution reconstructed in three dimensions and displayed on a dynamic graphics workstation. We ask whether different units (folia) in the paraflocculus receive information from the same population, from two different positively associated populations, or from segregated cell populations. We find a statistically significant tendency for cell populations projecting to adjacent folia to be positively associated, although there are few cells containing multiple labels. Populations of neurons projecting to folia wider apart are significantly segregated. From inspections of the reconstructions, using real-time rotations, we find that the swarms of labelled neurons tend to accumulate in shells or lamellae in the pons. Within the lamellae, the cells are aggregated in clusters and bands with empty holes (containing unlabelled ponto-cerebellar cell bodies, presumably projecting to other cerebellar targets) in between.(ABSTRACT TRUNCATED AT 400 WORDS)

Cellular and subcellular redistribution of glutamate-, glutamine- and taurine-like immunoreactivities during forebrain ischemia: a semiquantitative electron microscopic study in rat hippocampus.

The effect of 20 min of ischemia on the cellular and subcellular distribution of glutamate, glutamine and taurine in the rat hippocampus was studied by means of an immunocytochemical procedure based on antisera raised against protein glutaraldehyde conjugates of the respective amino acids. Forebrain ischemia was induced by temporary occlusion of the common carotid arteries in rats with permanently occluded vertebral arteries. Within 90 s after removal of the carotid ligatures, the rats were perfused through the heart with a mixture of glutaraldehyde and paraformaldehyde. For semiquantitative electron microscopic analysis, ultrathin sections were incubated in a primary antiserum followed by a secondary antibody coupled to colloidal gold particles. The gold particle densities over different tissue compartments within the CA1 field and the mossy fiber zone of the hippocampus were determined by means of a specially designed computer program, and values from normal and ischemic animals were compared. It was found that in the astrocytes, the level of immunoreactivity for glutamine and taurine is unchanged or slightly decreased after ischemia, while that for glutamate is increased, particularly within the mitochondria (by about 100%). In contrast, pyramidal cell bodies display a reduced immunolabeling for all three amino acids following the ischemic episode. The results show that ischemia causes a redistribution of glutamate from neurons to glia. The observed increase in the glial immunolabeling for glutamate indicates that the capacity of the glial cells to metabolize glutamate is exceeded during ischemia. This glial response to ischemia has not previously been recognized and may play a role in the chain of events leading to "excitotoxic" cell death during or following an ischemic episode. The reduction of glutamate and taurine immunolabeling in neurons points to a possible amino acid efflux and is compatible with previous biochemical studies demonstrating an elevated extracellular level of these amino acids during ischemia.

MORFOREL, a computer program for two-dimensional analysis of micrographs of biological specimens, with emphasis on immunogold preparations.

The program is a tool for accelerating analysis of tissue components (profiles) as seen in micrographs, including electron micrographs with immunoreactive substances labelled with gold particles. Required equipment is a computer with digitizer and printer. From coordinates sampled around the profiles, area, perimeter and form factor are calculated; particles in profiles, when wanted, are counted to obtain particle densities. MORFOREL permits basic statistical calculations on primary data or on composite expressions based on them. Expressions can be saved on disk and retrieved. Primary and calculated data are readily output in a format readable by common commercial packages.