Optical coherence tomography for observation of the olfactory epithelium in mice

Objective

Optical coherence tomography (OCT) is an imaging tool that exploits the coherence of infrared light and is clinically utilized in the field of ophthalmology and dermatology. This study aimed to examine the feasibility of using OCT for diagnosing degeneration and regeneration of the olfactory epithelium in mice.

In vitro hyperextension injuries in the human cadaveric cervical spine.

To investigate the relationship between the type of hyperextension injuries and the conditions producing them, nine cervical specimens (occiput to T1) were loaded to failure in tension at a fixed extension angle of 30 degrees. Under these loading conditions, specimens failed at average tensile loads and extension moments of 499 +/- 148 (SD) N and 4.0 +/- 3.1 Nm, respectively. Failure occurred at an average tensile displacement of 18.8 +/- 7.7 mm. The anterior longitudinal ligament ruptured and the intervertebral disc failed in at least one level in all specimens. In four specimens, the disc failed at an additional level, leaving the anterior longitudinal ligament intact at that site. With one exception, all injuries occurred in the lower cervical spine (C5-C6 and C6-C7), the region most often injured in vivo. The location of the injuries was associated with the degree of degeneration of the facet joints and the discs. The discs of the lower cervical spine were significantly more degenerated than those at the C2-C3 level. In addition, the degree of disc degeneration in the noninjured discs was significantly less than in the injured discs. These data help quantify the threshold of injury and the patterns of tissue damage resulting from hypertension loading of the cervical spine.     

A longitudinal study of the matrix changes induced in the intervertebral disc by surgical damage to the annulus fibrosus.

A 5 x 5-mm anterolateral incision was made in the annulus fibrosus (AF) of lumbar discs of 16 sheep; four animals of similar age not operated on were used as controls. The experimental animals were sacrificed 2, 4, 6, 8, 12, and 18 months postoperatively (PO), and the incised and adjacent lumbar discs were collected. Discs were dissected into four zones: AF (zones 1 and 2) and nucleus pulposus (NP) (zones 3 and 4) corresponding to the half of the AF in which the cut was made and its opposite half, and the complementary halves of the NP. Each zone was analyzed for moisture, proteoglycan (PG), collagen, and noncollagenous protein (NCP) content. The PG extractability, aggregation, and hydrodynamic size were also examined. The NP of injured discs showed a significant loss of PGs and collagen 8 months PO, but NCP levels increased. In the incised discs, PG aggregation initially declined but recovered to within control values 6-8 months PO. The NP of discs adjacent to the incised disc also showed time-dependent changes in matrix components that included loss of collagen and PG; however, the AF matrix remained essentially uneffected. Double immunodiffusion studies indicated that a sizeable proportion of the NCPs present in the injured discs (but not the adjacent lumbar discs) were derived from serum.     

The dendritic trees of neurons from the hippocampal formation of protein-deprived adult rats. A quantitative Golgi study

We have recently shown that lengthy periods of low-protein feeding of the adult rat lead to deficits in the number of hippocampal granule and pyramidal cells, and in the number of mossy fiber synapses. These findings prompted us to analyze the dendrites of these neurons to evaluate whether, under the same experimental conditions, degenerative and/or plastic changes also take place at the dendritic level. The hippocampal formations from five 8-month-old rats fed a low-protein diet (casein 8%) for 6 months from the age of 2 months and from five age-matched controls were Golgi-impregnated and the morphology of the dendritic trees quantitatively studied. We found that in malnourished animals there was a reduction in the number of dendritic branches in the dentate granule cells and in the apical dendritic arborizations of CA3 pyramidal neurons. In addition, in the dentate granule cells the spine density was markedly increased and the terminal dendritic segments were elongated in malnourished animals. No alterations were found in the apical dendrites of CA1 pyramidal cells. The results obtained show that long periods of malnutrition induce marked, although not uniform, changes in the dendritic domain of the hippocampal neurons, which reflect the presence of both degenerating and regrowing mechanisms. These alterations are likely to affect the connectivity pattern of the hippocampal formation and, hence, the activity of the neuronal circuitries in which this region of the brain is involved.     

退变性腰椎椎管狭窄症的病理变化及诊断治疗

本文报告１４６例退变性腰椎椎管狭窄症，其目的在于：探讨腰椎退变与椎管狭窄的关系，退变性椎管狭窄的临床特点及其治疗方法问题。本组全部经手术治疗，椎管扩大减压包括侧隐窝扩大，充分暴露受压神经根和硬膜囊是提高治疗效果重要措施，维持腰椎稳定是外科治疗重要内容。１３２例随访，平均３８个月，优良者１１２例（８４．８％）。研究表明，退变性腰椎管狭窄症，除中央椎管狭窄外，神经根管（包括侧隐窝）狭窄更多见。在外科治疗时必须注意这种病理变化特点，避免遗漏，影响手术效果。     

An electron microscopic study of Aujeszky's disease

Summary Sixteen calves were killed at intervals during the course of the disease from 48 h onwards after subcutaneous infection with Aujeszky's disease virus. Ultrastructural changes were evident in the spinal ganglia from 84 h post-inoculation and the intercostal nerves from 96 h post-inoculation. The cytopathic changes in the spinal ganglia consisted of neuronal degeneration, neuronophagia, Schwann cell degeneration and cellular infiltration. The neuronophagic nodule was invariably contained within an intact sheath of satellite cells. Changes in the intercostal nerves were less dramatic but cellular infiltration was frequently seen and occasional Schwann cells were degenerate. In the terminal stages of the disease demyelination was rarely observed. In the ganglion virus was invariably seen in degenerating neurons and occasionally in Schwann cells and monocytes. Satellite cells were rarely infected even when ensheathing an infected neuron. Extra-cellular virus was not observed in ganglia or nerves. Schwann cells and monocytes in the nerves were occasionally infected. Virus particles were seen in the axoplasm both in the ganglion and in the entire length of the nerve. The particles in the axoplasm varied in morphology; thus unenveloped and enveloped particles, and particles in the process of acquiring an envelope were recognised. It was concluded that the neural pathway of Aujeszky's disease virus is probablyvia the axoplasm.     

Origin of macrophages in traumatic lesions and Wallerian degeneration in peripheral nerves

Summary The origin of the macrophages in peripheral nerves was investigated in newborn rabbits after labelling the blood monocytes with intravenous carbon suspensions.Carbon labelled lipid macrophages were observed at the site of trauma in the nerves but not in areas of Wallerian degeneration. It is suggested that in Wallerian degeneration, resorption of degenerate tissue is performed by endogenous cells only, while in traumatic lesions part of the phagocytosis is performed by migrated monocytes. The early increase in vascular permeability in traumatic lesions may be a prerequisite for the attraction of the monocytes.     

Ultrastructural changes in the rat metrial gland in the latter half of pregnancy

Summary The ultrastructural changes occurring in the metrial gland in the latter half of pregnancy in the rat have been studied. Typical palely stained granulated cells are present in the metrial gland up to day 20 but many granulated cells show variations in appearance which may be associated with degeneration. In some the cytoplasm is more darkly stained and such cells often have apparently empty areas of cytoplasm adjacent to the granules. From day 14 onwards many areas of the gland show cellular debris, apparently resulting from lysis of the granulated cells. However, occasionally normal granulated cells are present in blood vessels and have been observed apparently penetrating the vascular endothelium. A variety of changes was also noted in the stromal cell population. Inclusions became apparent in many of these cells; some of these consisted of lipid while others resembled granules from the typical granulated cells. Other cells with numerous inclusions appeared to be macrophages. Lysis of granulated cells in situ is compatible with suggestions that the metrial gland produces a holocrine secretion, though some normal granulated cells enter blood vessels. The stromal cells may have a phagocytic role in late pregnancy but evidence for this was inconclusive.     

Ultrastructure of Tri-Ortho-Cresyl Phosphate poisoning in the chicken

Summary Electron-microscopic investigations of the spinal cord in adult chickens poisoned with TOCP (Tri-Ortho-Cresyl Phosphate) show pathological alterations as early as the first day after appearance of the clinical symptoms. Of the same qualitative order as in the peripheral nervous system, they refer to the nerve fibres in the white matter in form of primarily diseased axons, with proliferation of the endoplasmic reticulum and disintegration of the neurofilaments. In the grey substance of the anterior horn, in particular, one sees severe structural alterations in the boutons terminaux while the motoneurons are hardly modified. The most striking finding already in the early stage is a massive swelling of the spherical synaptic vesicles in the boutons of theS-type, attributed to axo-somatic synapses.This work was supported by the Swiss National Foundation (Grant No. 3503). Part of the work was carried out at the Research Laboratory, McLean Hospital, Belmont/Mass. under the direction of J. D. Robertson.     

Sur une polioencéphalopathie progressive avec dégénérescences neurofibrillaires

Resumé Une affection neurologique caracterisée par l'atteinte de nombreux nerfs craniens, des signes pyramidaux, des troubles de la sensibilité profonde, de la torpeur et de la désorientation, se présente chez une femme alcoolique âgée de 46 ans. Evolution en sept mois. Histologiquement: polioencéphalopathie avec plaques argyrophiles, dégénérescences neurofibrillaires et lipopigmentaires, sans raréfaction neuronale. Les formations les plus intéressées sont l'écorce hippocampique et les noyaux de la calotte mésencéphalique. La substance blanche du centre ovale et les faisceaux pyramidaux et postérieurs participent au processus.

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Progressive polioencephalopathy with neurofibrillary degeneration

Summary A case is presented of an alcoholic woman aged 46, with a progressive impairment of cranial nerves, bilateral pyramidal signs and involvement of deep sensation, clouding of the sensorium and loss of orientation. The disease run a fatal course in seven months. Histological examination disclosed a polioencephalopathy with argyrophilic plaques, neurofibrillary degeneration and accumulation of lipofuscin, without neuronal loss. Such changes were mostly evident in the hippocampal cortex and tegmental nuclei at midbrain level. White substance of centrum ovale, pyramidal tracts and posterior columns were also affected.

Nous tenons à remercier le Dr. Ludo van Bogaert pour son aide critique et disinteressée dans la formulation de ce travail, Mme Zunino et Mlle Janssens pour l'histologie, et M. Camusso pour la photographie.