Detection of thrombosis in microvessels with indocyanine green videoangiography.

Atherosclerosis is a systemic condition that is responsible for many diseases, and becomes a problem in cases where plaques form at several sites. The formation of a thrombotic embolus may jeopardise vascular operations, including microvascular anastomoses in replantation procedures or free tissue transfers. A mobile imaging tool for the detection of thrombosis preoperatively or intraoperatively would be valuable. An intimal injury, simulating removal of atherosclerotic plaques, was made microsurgically in 60 rat aortas, and results were analysed macroscopically, histologically, and with intraoperative indocyanine green (ICG) videoangiography immediately postoperatively. The Spearman and Pearson correlation tests were used to compare the three techniques. The sensitivity and specificity of ICG videoangiography was calculated in relation to both macroscopic and histological results. Detection of thrombosis was possible in 25 cases, and in 18 cases no thrombosis was correctly diagnosed by all methods used. In 31 of 60 specimens formation of thrombus was detected histologically, and in 29 of 60 examinations it was detected clinically, which yielded a correlation of 93.5% between the two examinations. Macroscopic analysis correlated better with ICG videoangiography (sensitivity 86.2% and specificity 64.5%) than histological observations (sensitivity 80.6% and specificity 62.1%). There was a significant correlation among all comparisons (each p≤0.001) with correlation indexes of 0.94, 0.52, and 0.44 for macroscopic/histological, clinical/ICG videoangiographic, and ICG videoangiographic/histological results, respectively. Our results show that ICG videoangiography is an important method for the detection of formation of acute thrombi and may be an important tool in vascular procedures.

[The cortisol awakening response in patients with acute and chronic low back pain. Relations with psychological risk factors of pain chronicity]. / Die Cortisol-Aufwachreaktion bei Patienten mit akuten und chronischen Rückenschmerzen. Zusammenhänge mit psychologischen Risikofaktoren der Schmerzchronifizierung.

BACKGROUND: Peculiarities of the hypothalamic-pituitary-adrenal axis activity in stress-related pain-disorders and potential relations with psychological risk factors of pain chronicity have been discussed controversially. MATERIAL AND METHODS: The cortisol awakening responses of 31 low back pain patients (14 acute, 17 chronic) and 14 healthy controls were compared. In addition the interrelations between awakening response and chronic stress as well as depressive mood and - for the first time - maladaptive painprocessing and -copingstrategies were investigated. RESULTS: The groups did not differ in their cortisol awakening responses. Chronic stress, depressive mood and maladaptive cognitive painprocessing did not correlate with the awakening response. There were, however, significant interrelations between awakening responses and the behavioral paincoping-strategies. CONCLUSIONS: Behavioral paincoping-strategies should be considered as a potentially important contributing psychological factor in the relation between the activity of the hypothalamic-pituitary-adrenal axis and stress-related pain disorders.

Vibrography: first experimental results in swine brains.

OBJECT: The aim of this study was to determine whether vibrography, an ultrasound-based real-time strain imaging method for registering the elastic properties of tissue, is superior to conventional ultrasound imaging techniques for detecting low-contrast space-occupying lesions in brain tissue and for delineating the boundaries between such lesions and the surrounding tissue. METHODS: As our experimental model we used swine brains taken from freshly slaughtered pigs. After injecting agarose into these brains at different depths, we compared both the conventional ultrasonographic images and the elastographic images of the region of interest with the corresponding anatomical brain sections. RESULTS: In 83.6 % of the experiments, it was possible to detect the polymerized agarose in the brain tissue with vibrographic techniques. In 17 experiments agarose lesions which were not detectable by ultrasound were visualized via vibrography. Furthermore, statistical analysis revealed that elastography is a more precise tool than conventional ultrasound for determining lesion size. CONCLUSION: These findings indicate that vibrography is a promising real-time imaging method with numerous potential applications in the field of neurosurgery. Visualization of the elastic properties provides the neurosurgeon with additional data on the lesion and the boundary between the lesion and the surrounding tissue.

A family showing recessively inherited multisystem pathology with aberrant splicing of the erythrocyte Band 7.2b ('stomatin') gene.

The case of a French child, born of consanguineous parents of Tunisian origin, is described. He showed a severe multisystem disease with dyserythropoietic, sideroblastic anaemia, delayed neurological development with hypotonia and convulsions, salt-losing nephropathy, chronic watery diarrhoea, lactic acidosis with mitochondrial dysfunction, brittle hair, hypergammaglobulinaemia, fatty liver with intermittent transaminasaemia, and terminal pulmonary fibrosis. Two siblings, of both sexes, were stillborn; two more lived only a short time. One sister is alive and well. SDS gel analysis of the red cell membranes showed a deficiency within 'Band 7' at 32 kDa. Analysis of the gene encoding 'stomatin', or 'erythrocyte membrane protein 7.2b', the principal protein of 'Band 7', revealed a complex series of aberrant spliceforms centred around exon 3, for which no explanatory genomic lesion could be found. The true underlying molecular cause of this condition remains obscure, but it suggests that the stomatin gene should be studied in other cases.

Nerve fibers innervating the cranial and spinal meninges: morphology of nerve fiber terminals and their structural integration.

Pachymeninx and leptomeninx of cranial cavity and spine are considerably different in their collagenous fiber texture, cellular composition, vascularization, and innervation. The majority of meningeal nerve fibers terminate as free nerve endings whereas encapsulated and lamellated nerve terminals additionally occur in higher vertebrates including man. With respect to nerve fiber classification, arborization pattern, topography, and organization of the microenvironment at the termination site afferent and efferent nerve terminals are differentiated. Only the dura mater and the pial subcompartment of the leptomeninx possess the morphological prerequisites for neurogenic inflammation. In the current review, the results of morphological studies regarding the meningeal innervation including the sites of CSF (cerebrospinal fluid) production and absorption are discussed with emphasis on their structure-function relationships.

Virtual image navigation: a new method to control intraoperative bleeding in neuroendoscopic surgery. Technical note.

In this neuroendoscopic study the authors tested the newly developed "red-out module" of their visual navigation system that enables the neurosurgeon to achieve hemostasis if total visualization is lost due to hemorrhage ("red out") within the visual field. An optical position measurement system connected to the endoscope guarantees that digitized endoscopic images are coupled with the accurate endoscopic position. Computerized images are simultaneously stored with their respective position data, and this creates a virtual anatomical landscape. The system was tested in in vivo bleeding conditions in a rat model. Artificial endoscopic cavities were created in the inguinal, pelvic, and jugular regions in rats to imitate the conditions of the human ventricular system. Two experimental settings were tested: Technique I, in which a computer landmark has been previously determined at the point where the vessel will be lesioned; and Technique II, in which a landmark has been previously set in the surrounding area of the vessel. Immediately after hemorrhage obscures the visual field (red out), the computer automatically displays the virtual images on a separate monitor. The previously set landmarks and the graphic overlay of the coagulation fiber enable the surgeon to navigate within the operative field based on the virtual images and to perform coagulation at the site of the lesion. A total of 175 vessels were coagulated: 43 arteries and 132 veins. In using Technique I, 130 (90.9%) of 143 vessels and in using Technique II, 26 (81.2%) of 32 arteries were successfully coagulated. The authors' data revealed that virtual image guidance has the potential to be a helpful tool in neuroendoscopy.

Phenomenological diversity of spinal reflexes in brain death.

In brain death, spinal reflexes and automatisms are observed which may cause irritation and even doubt in the diagnosis. In the literature there are no dedicated descriptions of the diversity and of neuroanatomical considerations. In 278 examinations of 235 patients for the determination of brain death, on 42 occasions obvious spinal reflexes and/or spinal automatisms were observed in 27 brain dead bodies. Because they were not systematically searched for, minute forms have probably been missed. The reflexes (R) and automatisms (A) are described according to the time of observation in relation to the development of brain death, the presumable spinal localization and the possible phylogenetical interpretation. Especially disquieting examples are discussed in more detail, e.g. monophasic EndotrachealSuction-ThoracicContraction-R supposedly switched in segments C2-6 or TrapeziusPinch-ShoulderProtrusion-R conveyed by the accessory nerve (terminology according to the scheme: for the reflexes, Trigger-Response-R: for the automatisms, Movement-A). After these experiences a more thorough examination showed frequent observations of rather minute forms of spinal reflexes, as well as automatisms and even the Lazarus sign (in possibly more than two thirds of the examinations). An estimation of the factual frequency would necessitate special attention to those much more frequent but less obvious minute spinal reflexes and automatisms.

Epithelial Na+ channels and stomatin are expressed in rat trigeminal mechanosensory neurons.

Caenorhabditis elegans MEC-4 and MEC-10 are subunits of the degenerin/epithelial Na+ channel (DEG/ENaC) ion channel superfamily thought to be associated with MEC-2 (a stomatin-like protein) in a mechanotransducing molecular complex in specialized touch sensory neurons. A key question is whether analogous molecular complexes in higher organisms transduce mechanical signals. To address this question, we selected mechanoreceptors of the rat vibrissal follicle-sinus complex in the mystacial pad and the trigeminal ganglia for an immunocytochemical and molecular biological study. RT-PCR of poly(A+) mRNA of rat trigeminal ganglia indicated that alpha-, beta-, and gamma-ENaC and stomatin mRNA are expressed in rat trigeminal ganglia. Using immunocytochemistry, we found that alpha-, beta-, and gamma-ENaC subunits and stomatin are localized in the perikarya of the trigeminal neurons and in a minor fraction of their termination site in the vibrissal follicle-sinus complex, where longitudinal lanceolate endings are immunopositive. We conclude that alpha-, beta-, and gamma-ENaC subunits as well as the candidate interacting protein stomatin are coexpressed in a mammalian mechanoreceptor, a location consistent with a possible role in mechanotransduction.

Subnuclear organization of the rat habenular complexes.

The habenular complexes represent phylogenetically constant structures in the diencephalon of all vertebrates. Available evidence suggests that this area is engaged in a variety of important biological functions, such as reproductive behaviors, central pain processing, nutrition, sleep-wake cycles, stress responses, and learning. Based on Nissl-stained sections, one medial nucleus and two lateral nuclei (divisions) have been widely accepted in the rat. Cytochemical, hodologic, and functional studies suggest a considerably more complex subnuclear structure. To improve our knowledge of the precise structural composition of the habenular complexes, we have systematically investigated their fine ultrastructure in the rat. Based on the detailed analysis of complete series of large, semithin sections supplemented with electron photomicrographs of selected fields, clear criteria for the delineation of five distinct subnuclei of the medial and ten subnuclei of the lateral habenular complexes were elaborated for the first time. All 15 subnuclei were reconstructed, and their dimensions were determined. A medial and lateral stria medullaris were described. Different roots of the fasciculus retroflexus were differentiated within the medial and lateral habenular complexes. The topographical relationships with respect to the adjacent habenular areas as well as to the neighboring thalamic nuclei were identified and demonstrated. The new understanding of the subnuclear organization of the habenular complexes certainly will facilitate further functional investigations. Whether the newly identified subnuclei finally will be recognized as functionally distinct awaits ongoing immunocytochemical, hodologic, and functional studies.

Development of an endoscopic navigation system based on digital image processing.

We developed a new system to couple the endoscope to an optical position measurement system (OPMS) so that the image frames from the endoscope camera can be labeled with the accurate endoscopic position. This OPMS is part of the EasyGuide Neuro navigation system, which is used for microsurgery and neuroendoscopy. Using standard camera calibration techniques and a newly developed system calibration, any 3-dimensional (3-D) world point can be mapped onto the view from the endoscope. In particular, we can display the coordinates of any anatomical landmark of the patient as it is viewed from the current position of the camera. This and other image-processing techniques are applied to the labeled frame sequence in order to offer the neurosurgeon a variety of control modules that increase the safety and flexibility of neuroendoscopic operations. Several modules, including a new motion alarm system and the "tracking" and "virtual map" modules, were tested in a human cadaveric model using the frontal and occipital approaches. A failure rate of 8.6% was experienced during testing of the first version of the software, but the second version was 100% successful. Thus, an endoscopic navigation system based on digital image processing has been developed that could be a revolutionary advance in image-guided surgery.

Topography and immunocytochemical characterization of nerve fibers in the leptomeningeal compartments of the rat. A light- and electron-microscopical study.

The localization of peptidergic, catecholaminergic, and nitroxidergic nerve fibers in the ventral leptomeningeal connective tissue compartment was studied in whole-mount preparations and serial semithin and ultrathin sections. For immunocytochemistry, whole-mount preparations of the leptomeninges and ventral brain slices with the meninges were incubated as free-floating specimens with primary antibodies against protein gene product 9.5 (PGP 9.5), substance P (SP), calcitonin gene-related peptide (CGRP), dopamine beta-hydroxylase (DbetaH), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), and nitric oxide synthase (NOS) using the avidin-biotin-peroxidase method. Based on the regional differences of the connective tissue organization, the leptomeninx is subdivided into the pial, trabecular, and adventitial leptomeninx. The antibody PGP 9.5 stains all unmyelinated nerve fibers in the leptomeninx. Although the highest density of nerve fibers occurs in the adventitial leptomeninx, nerve fibers, and terminals are additionally present in the trabecular and pial leptomeninx. DbetaH-, NPY-, VIP- and NOS-immunoreactive (IR) nerve fibers occur exclusively in the adventitial leptomeninx forming neuromuscular junctions. CGRP- and SP-IR nerve fibers are localized in all three leptomeningeal compartments where they terminate close to the subarachnoid space (type 1) or within the connective tissue (type 2). Due to their morphological and immunocytochemical characterization a possible chemo-, mechano- or nociceptive function is discussed in the context of pathophysiological aspects.

The endolymphatic duct and sac of the rat: a histological, ultrastructural, and immunocytochemical investigation.

A study of the ultrastructure, vascularization, and innervation of the endolymphatic duct and sac of the rat has been performed by means of light- and electron-microscopic and immunocytochemical methods. Two different types of epithelial cells have been identified: the ribosome-rich cell and the mitochondria-rich cell. These two cell types make up the epithelium of the complete endolymphatic duct and sac, although differences in their quantitative distribution exist. The morphology of the ribosome-rich cells varies between the different parts of the endolymphatic duct and sac; the morphology of the mitochondria-rich cells remains constant. According to the epithelial composition, vascularization, and structural organization of the lamina propria, both duct and sac are subdivided into three different parts. A graphic reconstruction of the vascular network supplying the endolymphatic duct and sac shows that the vascular pattern varies among the different parts. In addition, the capillaries of the duct are of the continuous types, whereas those supplying the sac are of the fenestrated type. Nerve fibers do not occur within the epithelium of the endolymphatic duct and sac. A few nerve fibers regularly occur in the subepithelial compartment close to the blood vessels; these fibers have been demonstrated in whole-mount preparations by the application of the neuronal marker protein gene product 9.5. Single beaded fibers immunoreactive to substance P and calcitonin-gene related peptide are observed within the same compartment. Dopamine-beta-hydroxylase-immunoreactive axons are restricted to the walls of arterioles. Morphological differences between the different portions of the endolymphatic duct and sac are discussed with regard to possible roles in fluid absorption and immunocompetence.

Topography and distribution of nerve fibers in the posterior longitudinal ligament of the rat: an immunocytochemical and electron-microscopical study.

The distribution and immunocytochemical characterization of nerve fibers and their terminals in the posterior longitudinal ligament of the rat lumbar vertebral column was studied in whole-mount preparations and serial semithin and ultrathin sections. Differences in the localization, distribution pattern and density of peptidergic and catecholaminergic nerve fibers were found in the vertebral and intervertebral regions of the posterior longitudinal ligament. For immunocytochemistry, free floating specimens were incubated with primary antibodies against protein gene product 9.5, substance P, calcitonin gene-related peptide, dopamine-beta-hydroxylase, vasoactive intestinal polypeptide and neuropeptide Y together with the avidin-biotin-peroxidase method. In whole-mount preparations, the neural marker protein gene product 9.5 is immunostained in all unmyelinated nerve fibers in the posterior longitudinal ligament, thus giving a panoramic view of the nerve fiber plexus. The most striking nerve fiber plexus is localized in the intervertebral region. In this region, the posterior longitudinal ligament is rich in capillaries that form a dense plexus within its ventral part and extend to the outer layer of the annulus fibrosus. The peptidergic and catecholaminergic innervation of the posterior longitudinal ligament is discussed in the context of pain syndromes related to the vertebral column and degenerative lumbar spine diseases.

Topography and fine structure of proprioceptors in the hagfish, Myxine glutinosa.

Topography and ultrastructural organization of proprioceptors in the striated parietal muscle of the hagfish, Myxine glutinosa, are described. Due to the topographical location of the afferent nerve terminals four subtypes of proprioceptors are distinguished. Type 1-receptor and type 2-receptor are localized in an encapsulated and lamellated corpuscular organ located along and above the myosepta of the parietal muscle. Type 3-receptor is composed of a complex of free en plaque nerve endings within the dense collagen fibre texture at the site where myoseptum, muscle fascia and body fascia fuse to a raphe. Type 4-receptor resembles type 3 but it is localized in the straight collagen fibre bundles of the myoseptum and the body fascia. A proprioceptive function of the nerve terminals is discussed.

Lamellated receptors in the skin of the hagfish, Myxine glutinosa.

The adult hagfish, Myxine glutinosa, does not exhibit a lateral line system. The hypodermal layer of the dorsal head and body skin contains a prominent receptor system--lamellated corpuscles--arranged in a segmental pattern close to the body fascia. The topography and the structural organization of the lamellated receptors are described at the light- and electronmicroscopical levels. Spinal nerves supply the lamellated receptor organs. A mechanoreceptive function and evolutionary aspects are discussed.

Actin, myosin and alpha-actinin containing filament bundles in hyaline cells of the caiman cochlea.

Hyaline cells of the auditory organ of the spectacled caiman contain smooth muscle-like filament bundles within their basal cell pole. These bundles were heavily labeled with antibodies to actin, myosin and alpha-actinin (muscular Z-line protein). Since hyaline cells are firmly attached to the basilar membrane these cells may actively modify the stiffness of the basilar membrane. A contractile mechanism in hyaline cells might affect frequency tuning of primary auditory afferents. This frequency tuning has been shown to be a temperature-dependent process in caimans and other submammalian species. The presence of synaptic contacts between efferent nerve fibres and hyaline cells suggests neural control of hyaline cell activity.

Sensory nerve fiber terminals in the arachnoid granulations of non-human primates.

Myelinated and unmyelinated axons terminate within the arachnoid granulations. Serial section analysis by light and transmission electron microscopy reveals that the nerve fibers terminate at different locations or tissue compartments of the arachnoid granulation. 1. Myelinated axons ramify and terminate as free axon terminals like slowly adapting type II mechanoreceptors in the leptomeningeal connective tissue core of the granulation. 2. Myelinated and unmyelinated axons terminate in the transitional spongy zone which represents a tissue compartment for the diffusion of the cerebrospinal fluid from the subarachnoidal space to the venous sinus. This zone is composed of arachnoidal cells, dural neurothelial cells and fibrocytes. 3. Myelinated and unmyelinated axons terminate within lymphoid cell aggregation associated to the arachnoid granulation.

The anatomy and fine structure of the echidna Tachyglossus aculeatus snout with respect to its different trigeminal sensory receptors including the electroreceptors.

The gross anatomy and nerve supply of the bill of echidna (Tachyglossus aculeatus) is described in relation to its function as an outstanding sensory organ. The sensory innervation of the skin of the echidna snout was investigated by means of frontal serial sections, after decalcification of the specimens. A comprehensive light and electron microscopic description of the location and fine structure of cutaneous sensory receptors of the trigeminal system was made by this means. The encapsulated and non-encapsulated Ruffini receptors, the types of other free receptors in the connective tissue and the Merkel cell receptor do not differ morphologically from those of higher mammals, whereas the pacinian-like corpuscle shows a unique organization of its outer core. This is composed of large perineural cells containing a unique reticulum of parallel-orientated endoplasmic membranes. Lamellated corpuscles, seen in isolation or in association with push rods, are numerous in the snout and in the tip of the tongue of echidna. Push rod receptor organs occur in the hairless skin of the bill with a very dense array at its rostral end and in the pseudopalatal ridges. Gland duct receptors are restricted to the skin adjacent to the nostrils and the mouth opening, including the pseudopalatal plates. Only about one quarter of the total number of 400 seromucous glands receive a sensory innervation of their intraepidermal duct segment. Within each innervated gland two types of receptor terminals are identified. The distributions of the different receptor types are mapped for different regions of the skin, the mucous membrane of the nasal and oral vestibule and the tip of the tongue. The fine structure of nerve terminals is discussed from a comparative anatomical point of view, and some speculations are made about possible transduction processes that underlie the known electrophysiological properties. The sensory organs such as the "push rod" and "gland duct receptor", and most of their sensory terminals, are less differentiated in echidna snout than in the platypus (Ornithorhynchus anatinus) bill.

Neuropeptide Y- and substance P-like immunoreactive nerve fibers in the rat dura mater encephali.

Density and pattern of nerve fibers with neuropeptide Y-like immunoreactivity (NPY-LI) and substance P-like immunoreactivity (SP-LI) in the rat dura mater encephali were investigated by light and electron microscopy using whole-mount preparations. NPY-LI fibers are observed throughout the encephalic dura mater. A remarkable net of NPY-LI nerve fibers is located in the walls of the sagittal and transverse sinuses. Beyond that NPY-LI network, distinct NPY-LI nerve fibers or plexus occur in the rostral falx, parietal dura mater of the olfactory bulb, supratentorial dura mater, parietal dura mater of the cerebellum, tentorium cerebelli and the ventral dura mater. Electron microscopic studies reveal that NPY-LI is exclusively located in unmyelinated axons of small and large nerve fiber bundles, with or without a perineural sheath. Immunopositive C-fibers are predominantly associated with the vascular bed. SP-LI nerve fibers have a moderate and more uniform distribution in the encephalic dura mater. A distinct plexus of SP-LI fibers follows the branches of the middle meningeal artery and the adjacent dura mater. SP-LI fibers are most prominent in the parietal dura mater of the cerebellum. Fine beaded SP-LI fibers, arising from larger SP-LI fiber bundles, are observed in close association to the capillary bed. SP-LI axons are all unmyelinated. They are found in larger nerve fiber bundles with a perineural sheath or in Schwann cells lacking any perineural sheath. The function of NPY-LI and SP-LI nerve fibers in the rat dura mater is discussed in relation to their topography, density and termination.

The fine structure of ampullary and tuberous electroreceptors in the South American blind catfish Pseudocetopsis spec.

Two types of electroreceptors, the ampullary and the tuberous electroreceptor (silurid knollenorgan) in the epidermis of the catfish, Pseudocetopsis spec., were investigated with semithin and ultrathin serial sections. The ampullary organ contains one or two sensory cells which are embedded in supporting cells at the base of open epithelial canals. They bear some slender microvilli on their apical surface and form several synaptic bars. The afferent myelinated nerve fiber arborizes in the connective tissue papilla and looses its myelin sheath about 30 micron below the supporting cell layer. A second thin myelinated axon occur up to the supporting cell layer. The tuberous electroreceptor organ contains one large receptor cell. Most of the cell body is exposed to the lumen of a specialized proximal canal segment and is closely covered with microvilli. A single myelinated axon looses its myelin sheath within the supporting cell layer about 1 micron before terminating as a flat calyx at the base of the sensory cell. A functional significance of the two types of receptors will be discussed.