Mucocele in an Onodi cell responsible for acute optic neuropathy.

An Onodi cell is defined as the most posterior ethmoid cell, which pneumatizes laterally and superiorly to the sphenoid sinus. A rare case of an isolated mucocele in an Onodi cell with unilateral acute visual disturbance is presented. MRI was imperative for the early and accurate diagnosis, and prompt surgical drainage resulted in dramatic visual recovery.

Reactive oxygen: its sources and significance in Alzheimer disease.

Over the past decade, oxidative stress has been established as the earliest cytological feature of Alzheimer disease and an attractive therapeutic target. The major challenges now are establishing the source of the reactive oxygen and what oxidative stress tells us about the etiology of Alzheimer disease. These are complex issues since a variety of enzymatic and non-enzymatic processes are involved in reactive oxygen formation and damage to macromolecules. In this review, we consider disease mechanisms that show the greatest promise for future research.

Oxidative damage is the earliest event in Alzheimer disease.

Recently, we demonstrated a significant increase of an oxidized nucleoside derived from RNA, 8-hydroxyguanosine (8OHG), and an oxidized amino acid, nitrotyrosine in vulnerable neurons of patients with Alzheimer disease (AD). To determine whether oxidative damage is an early- or end-stage event in the process of neurodegeneration in AD, we investigated the relationship between neuronal 8OHG and nitrotyrosine and histological and clinical variables, i.e. amyloid-beta (A beta) plaques and neurofibrillary tangles (NFT), as well as duration of dementia and apolipoprotein E (ApoE) genotype. Our findings show that oxidative damage is quantitatively greatest early in the disease and reduces with disease progression. Surprisingly, we found that increases in A beta deposition are associated with decreased oxidative damage. These relationships are more significant in ApoE epsilon4 carriers. Moreover, neurons with NFT show a 40%-56% decrease in relative 8OHG levels compared with neurons free of NFT. Our observations indicate that increased oxidative damage is an early event in AD that decreases with disease progression and lesion formation. These findings suggest that AD is associated with compensatory changes that reduce damage from reactive oxygen.

[Magnetic resonance imaging findings of postresuscitation encephalopathy: sequential change and correlation with clinical outcome].

OBJECTIVE: The purpose of this study was to describe the findings of sequential magnetic resonance imaging (MRI) in postresuscitation encephalopathy. Although its outcome is known to be overwhelming, but its acute findings by variable imaging methods are subtle and show only limited values. The correlation of the findings of MRI with clinical outcome were also analyzed. METHODS: Twelve patients with global cerebral anoxia who underwent MRI with conventional and diffusion-weighted imaging were enrolled in this study. Compared with normal MRI images, abnormal signal regions were checked and described in cortex, basal ganglia and white matter. Also medical records were carefully reviewed to study the cause, the time necessary for resuscitation and long term clinical outcome. RESULTS: The earliest finding was obtained by diffusion-weighted image less than 24 hours (acute period) in bilateral cerebral cortex as bright high signal intensity regions. Similar abnormality of bright high signal area in FLAIR and T 2 was followed according to the time elapsed in early subacute period (1-13 days). Succeedingly, white matter was involved and laminar necrosis in cortical area was observed in late subacute period (14-20 days). Finally, diffuse brain atrophy and obtundation of gray-white matter junction were seen in chronic stage (after 21 days). These MR findings were coincided well with histopathological findings reported in literatures. The poor outcome was closely and significantly correlated with abnormality in MR images. CONCLUSION: MRI was a useful diagnostic modality to diagnose the whole brain ischemic encephalopathy and to predict the prognosis.

CI-ATPase and Na+/K(+)-ATPase activities in Alzheimer's disease brains.

The enzyme activities and the protein levels of Cl(-)-ATPase and Na+/K(+)-ATPase were examined in Alzheimer's disease (AD) brains. Cl(-)-ATPase and Na+/K(+)-ATPase activities in AD brains (n = 13) were significantly lower than those in age-matched control brains (n = 12). In contrast, there was no significant difference in anion-insensitive Mg2(+)-ATPase activity between the two groups. Western blot analysis revealed that the protein levels of Cl(-)-ATPase, Na+/K(+)-ATPase and neuron specific Na+/K(+)-ATPase alpha3 isoform were also significantly reduced in AD brains, while the amount of protein disulfide isomerase, one of the house keeping membrane proteins, was not different between the two groups. The data first demonstrated that Cl(-)-ATPase and Na+/K(+)-ATPase are selectively impaired in AD brains, which may reduce the gradients of Na(+), K(+) and Cl(-) across the cell membranes to cause excitotoxic cellular response and the resulting neuronal death.

Optimization of a polarized photometric detector equipped with a split-type flow cell and its analytical application to oligo-saccharides.

A novel, non-modulated polarimeter called a polarized photometric detector (PPD) was previously described by the authors. The PPD enables the measurement of the optical rotation of chiral compounds as a change in absorbance by placing two linear polarizers on either side of a flow cell of a conventional photometric detector. The present study describes the optimization of the conditions of PPD for highly sensitive detection of saccharides. To maximize the light intensity, the light balancing filter and slit were removed from the detector (Shimadzu model SPD-10AV). These modifications resulted in an approximately 15-fold increase in the incident light intensity when the maximum current was applied to the lamp. When this intense light was transmitted through the polarizers, the signal intensity followed the theoretical equation for phase angles up to around 1 rad. If the energy of the transmitted light was less than 700 mV, however, the baseline noise was too great to determine the chiral analyte accurately. Setting the phase angle between two polarizers at 50 degrees and the detection wavelength at 400 nm provided the most suitable conditions. This detector was applicable for the determinations of oligosaccharides in foodstuffs separated by HPLC using gradient elution.

Malignant pleomorphic adenoma (malignant mixed tumor) of the trachea. Report of a case.

Malignant pleomorphic adenoma arising in the trachea has not been reported in the literature. We report here a case of malignant pleomorphic adenoma (malignant mixed tumor) occurring in the trachea of a 65-year-old woman. The tumor metastasized to the lung and the chest wall 11 years after complete resection of the primary tumor, which was a polypoid submucosal tumor, 1.3 cm in diameter. Light microscopic examination of the primary and metastatic tumors showed the presence of epithelial and stromal elements, consisting of grandular structures, foci of squamous metaplasia and a myxochondroid stroma. Many tumor cells showed myoepithelial cell features by electron microscopy, and immunoreactivity for S-100 protein and GFAP was also seen in many of them. These findings were consistent with those of pleomorphic adenoma. However, the epithelial elements were cytologically atypical with prominent mitotic figures. Infiltration of the tumor cells into the surrounding soft tissue was also seen. No foci of benign pleomorphic adenoma were found in the primary tumor. These findings indicate that this tumor was not a carcinoma ex pleomorphic adenoma, but a true malignant pleomorphic adenoma (true malignant mixed tumor) of the trachea.

Neurothekeoma. Report of a case with immunohistochemical and ultrastructural studies.

A case of neurothekeoma in a 52-year-old woman is reported. The tumor developed on the medial aspect of the right nostril as a well-demarcated, dome-shaped, erythematous nodule of rubbery consistency. Microscopically, it consisted of numerous nests and cords of spindle-shaped cells in the dermis. Some of the tumor cell nests appeared epithelial-like, while the other areas showed a myxomatous appearence with various amount of mucinous matrix in the intercellular space. Neurothekeoma is a benign cutaneous tumor, and is considered to be of schwann cell origin. In the present case, the tumor cells did not stain positively for S-100 protein, despite the light microscopic suggestion of peripheral nerve origin. Ultrastructurally, most tumor cells contained a large number of myelinoid figures. This ultrastructural finding appears to be a useful diagnostic characteristics of neurothekeomas.