A serum factor enhances production of nitric oxide and tumor necrosis factor-alpha from cultured microglia

The pathological activation of microglia has been implicated in ischemic neuronal damage and some neurodegenerative diseases; however, the mechanism of microglial activation is not well understood. Previously, we showed that a serum factor, albumin, increased O(2)(-) production by cultured microglia (Si et al., 1997, Glia 21: 413-418). In the present study, we found that serum also enhanced lipopolysaccharide (LPS)-induced production of nitric oxide and tumor necrosis factor-alpha, which are other important neurotoxins released by activated microglia. In the presence of 0.1% normal rat serum, the half-effective concentration for LPS decreased from 300 to 1 ng/ml. The factor seemed to be a relatively high-molecular-weight protein because the factor was retained after a molecular sieve (50 kDa) membrane separation. The factor was labile to trypsinization and heat treatment at 72 degrees C for 5 min but was stable at 56 degrees C for 60 min. Several purified serum proteins including albumin could not mimic the enhancing effect of serum. Acute-phase serum showed a potent enhancing effect at a 10 times lower concentration than the normal serum. By gel filtration chromatography, the enhancing effect observed was a single peak at about 60 kDa. These results suggest that some serum protein infiltrates into brain parenchyma after blood-brain barrier disruption and such protein may result in neuronal damage by activating microglia to release neurotoxins in some central nervous system diseases.     

Dynamic spatiotemporal gene expression in embryonic mouse thalamus

The anatomy of the mammalian thalamus is characterized by nuclei, which can be readily identified in postnatal animals. However, the molecular mechanisms that guide specification and differentiation of neurons in specific thalamic nuclei are still largely unknown, and few molecular markers are available for most of these thalamic subregions at early stages of development. We therefore searched for patterned gene expression restricted to specific mouse thalamic regions by in situ hybridization during the onset of thalamic neurogenesis (embryonic [E] days E10.5-E12.5). To obtain correct regional information, we used Shh as a landmark and compared spatial relationships with the zona limitans intrathalamica (Zli), the border of the p2 and p3 compartments of the diencephalon. We identified genes that are expressed specifically in the ventricular zone of the thalamic neuroepithelium and also identified a number of genes that already exhibited regional identity at E12.5. Although many genes expressed in the mantle regions of the thalamus at E12.5 showed regionally restricted patterns, none of these clearly corresponded to individual thalamic nuclei. We next examined gene expression at E15.5, when thalamocortical axons (TCAs) project from distinct regions of the thalamus and reach their targets in the cerebral cortex. Regionally restricted patterns of gene expression were again seen for many genes, but some regionally bounded expression patterns in the early postnatal thalamus had shifted substantially by E15.5. These findings reveal that nucleogenesis in the developing thalamus is associated with selective and complex changes in gene expression and provide a list of genes that may actively regulate the development of thalamic nuclei.     

Characterization of human monocytes maintained in long-term culture with functional and morphological homogeneity

We recently reported a method for long-term in vitro culture of human monocytes with maintenance of functional and morphological homogeneity. We have now used microexudate-coated flasks to improve both the plating efficiency and the purity of these cultures. The technique is based on pregrowth of BHK cells that presumably produce large amounts of fibronectin, thus coating the flask with this substance, for which monocytes have receptors. We have further characterized the monocytes obtained with this culture technique by scanning electron microscopy (SEM), transmission electron microscopy (TEM), cytochemistry, surface markers, lectin receptors, and phagocytic functions. All these methods show the cultured cells to consist of a pure, functionally and morphologically homogeneous population of nontransformed monocytes.     

Severe fenitrothion poisoning complicated by rhabdomyolysis in psychiatric patient

Non-traumatic rhabdomyolysis associated with organophosphate intoxication has not been generally reported. We report here in a severe case of fenitrothion poisoning complicated by rhabdomyolysis. A 43-year-old woman ingested approximately 100 ml of fenitrothion emulsion (50%) in an attempt to commit suicide. On day 3 after admission, her creatine phosphokinase (CPK) peaked at 47,762 IU/L. She received supportive treatment included sodium bicarbonate and fluid resuscitation. However, muscarinic symptoms including excessive miosis and salivation developed on day 5 when her CPK levels decreased. The delay in cholinergic symptoms might have been due to the trihexyphenidyl she took with the antipsychotic drugs. Fortunately, the present patient recovered from the acute cholinergic crisis, and acute renal failure was prevented by early diagnosis. This is a case of organophosphate poisoning complicated by rhabdomyolysis in a psychiatric patient. The masking of acute cholinergic symptoms should be taken into consideration in such patients.     

<Emphasis Type=Italic>Hunter disease eClinic:</Emphasis>interactive,computer-assisted,problem-based approach to independent learning about a rare genetic disease

Background  

Computer-based teaching (CBT) is a well-known educational device, but it has never been applied systematically to the teaching of a complex, rare, genetic disease, such as Hunter disease (MPS II).     

Clinicopathological characteristics of esophageal squamous papillomas in Japanese patients--with comparison of findings from Western countries

To clarify the characteristics of esophageal squamous papillomas (ESPs) in the Japanese population, we investigated 38 ESPs of 35 Japanese patients from a file with 17,387 upper gastrointestinal endoscopies in our university hospital. ESPs accounted for 0.20% of the total number of endoscopies and comprised 21 females and 14 males with an average age of 59.2 years. More than half of the ESPs (52.6%) were located in the middle esophagus. The ratio of human papilloma virus (HPV) positive ESPs was 10.5% and all were located in the middle esophagus of female patients only. HPV-positive ESP cases were younger (46.8 years) than HPV-negative cases (60.8 years). Based on comparison with the reports from western countries, we attribute the low prevalence in the lower esophagus to the relatively fewer occurrences of severe reflux esophagitis (RE) due to chronic gastritis with low gastric acid secretion among Japanese patients.