Cadaveric surgical demonstration of middle to distal ureteral injury repairs in urologic and gynecologic surgeries.

Introduction And Hypothesis: Iatrogenic ureteral injuries can occur during any surgery but are more likely to occur during urologic and gynecologic procedures. The middle and distal ureter are especially at risk of injury during these surgeries.

Methods: The objective of this surgical educational video was to demonstrate how to repair middle to distal ureteral injuries with the following techniques: direct ureteroureterostomy, ureteroneocystotomy, vesico-psoas hitch, and Boari-Ockerblad bladder flap.

Bilateral inguinal lipoblastomas presenting as inguinal hernias.

Lipoblastomas are rare, encapsulated tumors arising from embryonic white fat. They primarily occur in infancy and early childhood and have a male predominance. Lipoblastomas are usually located on the trunk and extremities although may develop on the head and neck, mediastinum, abdomen, and retroperitoneum.

Retinal prosthesis that incorporates the organization of the nerve fibre layer.

Recent efforts to restore partial vision in blind patients have made significant progress. Currently, prosthetic design concentrates on stimulating as many foveal retinal ganglion cells as possible but is hampered by stimulation of the nerve fibre layer. This results in a nonvisuotopic arrangement of phosphenes (stimulation percepts).

Analysis of the lateral geniculate nucleus in dichromatic and trichromatic marmosets.

Marmosets are diurnal New World monkeys that show sex-linked cone photopigment polymorphism, whereby all males and some females are dichromats ("red-green colorblind"), but most females show trichromatic color vision. Here we asked whether trichromats express chromatic-specific circuitry in the lateral geniculate nucleus (LGN). The volume of parvocellular (P), magnocellular (M), and koniocellular (K) layers was calculated in Nissl-stained sections from the LGN of adult marmosets (Callithrix jacchus; 10 trichromatic females; 2 dichromatic females; and 13 dichromatic males).

Human intraretinal myelination: axon diameters and axon/myelin thickness ratios.

Purpose: Human intraretinal myelination of ganglion cell axons occurs in about 1% of the population. We examined myelin thickness and axon diameter in human retinal specimens containing myelinated retinal ganglion cell axons.

Materials And Methods: Two eyes containing myelinated patches were prepared for electron microscopy.

Localization and developmental expression patterns of CSPG-cs56 (aggrecan) in normal and dystrophic retinas in two rat strains.

Proteoglycans have a number of important functions in the central nervous system. Aggrecan (hyaluronan-binding proteoglycan, CSPG-cs56) is found in the extracellular matrix of cartilage as well as in the developing brain. We compared the postnatal distribution of CSPG-cs56 in Long Evans (LE) and Royal College of Surgeons (RCS) rat retinas to determine if this proteoglycan played a role in the development of dystrophic retinas.

Projections from cingulate cortex to the cat's thalamic reticular nucleus.

The cingulate cortex (CG) and the adjacent region designated as the splenial visual area (SVA) project to areas of the extrageniculate thalamic system that are concerned with processing visual information. En route to the thalamus, they pass through the thalamic reticular nucleus (TRN), an important source of thalamic inhibition. We wished to determine whether SVA axon collaterals projected to the previously defined visual sector of the TRN or a separate projection zone and did this differ from the projection zone of CG.

Noggin induces human bone marrow-derived mesenchymal stem cells to differentiate into neural and photoreceptor cells.

The present study was undertaken to explore the effect of noggin on neuronal differentiating potential of human bone marrow-derived mesenchymal stem cells (hBMMSCs) in vitro so as to provide a means of alleviate retinal degeneration. A green fluorescent protein-tagged noggin gene was transferred into adult hBMMSCs or induce hBMMSCs with classical inducer, epidermal growth factor(EGF). Neurons were observed as early as 48 h after transduction of hBMMSCs with a noggin adenoviral vector.

Influence of 'feedback' signals on spatial integration in receptive fields of cat area 17 neurons.

'Feedback' signals from mammalian extrastriate visual cortices are reported to exert primarily an excitatory influence on the classical receptive field (CRF) of neurons in the primary visual cortex (V1). However, given the much larger CRFs of neurons in extrastriate visual cortices it is not yet understood how feedback signals influence the spatial integration of visual signals by V1 neurons. To investigate this, we reversibly inactivated one of the 'form-processing' extrastriate visual cortices, the postero-temporal visual (PTV) cortex, and examined changes in responses of V1 neurons to drifting grating patches up to 28 degrees in diameter.

Contrast dependence of center and surround integration in primary visual cortex of the cat.

The magnitudes of spike responses of area 17 (striate cortex, area V1) neurons to stimulation of their classical receptive fields were reduced (suppressed) when the stimuli extended into the silent surround regions. We found that when optimally oriented sine-wave drifting grating patches extended into the distant parts of silent surround regions, over 35% of V1 neurons showed a 'counter-suppression', that is, a reduction in the magnitude of suppression. The magnitudes of both the suppression and the counter-suppression effects were dependent on stimulus contrast, that is, with a decrease of contrast the magnitude of suppression decreased, while the magnitude of counter-suppression increased.

First order connections of the visual sector of the thalamic reticular nucleus in marmoset monkeys (Callithrix jacchus).

The thalamic reticular nucleus (TRN) supplies an important inhibitory input to the dorsal thalamus. Previous studies in non-primate mammals have suggested that the visual sector of the TRN has a lateral division, which has connections with first-order (primary) sensory thalamic and cortical areas, and a medial division, which has connections with higher-order (association) thalamic and cortical areas. However, the question whether the primate TRN is segregated in the same manner is controversial.

Do first order and higher order regions of the thalamic reticular nucleus have different developmental timetables?

The thalamic reticular nucleus (TRN) can been subdivided into sectors based on thalamic and cortical input. Additionally, in carnivores the visual sector of the TRN can be subdivided into first order (perigeniculate nucleus: PGN) and higher order (TRN) regions. This report examines whether TRN development reflects the nature of its higher order visual connections.

Geniculocortical relay of blue-off signals in the primate visual system.

A fundamental dichotomy in the subcortical visual system exists between on- and off-type neurons, which respectively signal increases and decreases of light intensity in the visual environment. In primates, signals for red-green color vision are carried by both on- and off-type neurons in the parvocellular division of the subcortical pathway. It is thought that on-type signals for blue-yellow color vision are carried by cells in a distinct, diffusely projecting (koniocellular) pathway, but the pathway taken by blue-off signals is not known.

'Simplification' of responses of complex cells in cat striate cortex: suppressive surrounds and 'feedback' inactivation.

In mammalian striate cortex (V1), two distinct functional classes of neurones, the so-called simple and complex cells, are routinely distinguished. They can be quantitatively differentiated from each other on the basis of the ratio between the phase-variant (F1) component and the mean firing rate (F0) of spike responses to luminance-modulated sinusoidal gratings (simple, F1/F0 > 1; complex, F1/F0 < 1). We investigated how recurrent cortico-cortical connections affect the spatial phase-variance of responses of V1 cells in the cat.