Strain differences in peritoneal macrophage activity and susceptibility to experimental allergic encephalomyelitis induction in rats

The objective of the present study was to investigate the relevance of peripheral macrophage activity for the susceptibility to the induction of experimental allergic encephalomyelitis (EAE). Rats of EAE-susceptible Dark Agouti and EAEresistant Albino Oxford strain were immunized with guinea pig spinal cord homogenate (DA_GPSC and AO_GPSC), while non-immunized rats served as controls (DA_NIM, AO_NIM). On day 15 after immunization rats were sacrificed and their peritoneal macrophages tested for adherence capacity, zymosan phagocytosis and respiratory burst. Macrophages from AONIM rats exhibited lower adherence capacity and higher phagocytosis and H₂O₂ production when compared to macrophages from DANIM rats. Immunization with GPSC decreased adherence and phagocytosis and increased H₂O₂ production in macrophages from AO rats, but did not influence these activities in macrophages from DA rats. The results from the present study suggest that inflammatory activities of macrophages from AO rats could be considered as regulatory mechanisms connected with the resistance to EAE induction.     

Vacuolated cell mesothelioma of the pericardium resembling liposarcoma: a case report

We report a case of localized pericardial mesothelioma with unusual histological features in a 44-year-old woman. Her radiological imagings showed an 11-cm pericardial tumor, between the heart and aortic arch. Microscopically, the tumor was predominantly composed of vacuolated cells and vaguely reminiscent of well differentiated "lipoma-like" liposarcoma, but only small foci of the tumor showed the papillotubular configuration. Histochemically, the tumor cells contained hyaluronic acid in the vacuoles but no lipids. Immunohistochemically, they showed immunoreactivity for cytokeratin, calretinin, vimentin, and epithelial membrane antigen. Ultrastructural study showed that the vacuoles of the tumor cells were intracytoplasmic lumina. The intracytoplasmic lumina and the surface membranes of the tumor cells had many long and slender microvilli with focal bush-like appearance. Desmosomes between adjacent cells were occasionally observed. To our knowledge, this is the first case report of epithelial type mesothelioma predominantly composed of vacuolated tumor cells, microscopically mimicking liposarcoma.     

Horizontal vestibular nystagmus. I. Identification of medial vestibular neurones

1. The properities of inputs from the horizontal semi-circular canal to neurones of the medial vestibular nucleus have been studied intracellularly in the unanaesthetized encéphale isolé cat. 2. Secondary neurones of the bestibulo-abducens reflex arc were identified by their orthodromic response to labyrinthine stimulation and by antidromic excitation from the contralateral abducens nucleus. 3. The responses of medial vestibular cells receiving only labyrinthine in puts are also described. These were seen to be predominantly excitatory though IPSPs were observed in a few cases. 4. Identified vestibular neurones were intracellularly injected with procion yellow and showed different morphological characteristics correlated with function.     

Low levels of immunoglobulin A in children with intrinsic asthma: a possible protection against atopy

Immunoglobulin A and G (IgA, IgG) serum concentrations were detected in children with nonallergic/intrinsic (36 children) or allergic/extrinsic asthma (43 children) and in age-matching control children (40 children). Asthmatic children with allergic asthma had lower IgA (1.36+/-0.54 g/L) and higher IgG (10.48+/-2.77 g/L) levels than the age-matching control children group (1.63+/-0.69 vs. 9.01+/-2.32 g/L). Children with nonallergic/intrinsic asthma had lower IgA (1.03+/-0.41 g/L) ( p = 0.004) and IgG (8.38+/-1.93 g/L) (p = 0.001) levels than the allergic/extrinsic asthma group (1.36+/-0.54 vs. 10.48+/-2.77 g/L). Low IgA levels were found in children with nonallergic/intrinsic asthma and high IgG levels were found in those children with allergic/extrinsic childhood asthma. The hypothesis is that the increased incidence of asthma in the population may be caused by a decrease in childhood infections (hygiene hypothesis). Frequent infections in early life boost the immune system, stimulating Th1-type response in young children and reducing the risk of atopic diseases. Our hypothesis is that low IgA (and/or IgG) levels in our patients might be responsible for infection development among those children with nonallergic/intrinsic asthma. These infections stimulate the normal development of immune system in young children, reducing risk of atopy, so that those children do not get allergic/extrinsic childhood asthma. Intrinsic childhood asthma=nonallergic (nonatopic) childhood asthma. Extrinsic childhood asthma=allergic (atopic) childhood asthma.     

Determination of mandelic acid enantiomers in urine by gas chromatography and electron-capture or flame ionisation detection

A sensitive and stereospecific GC method was developed for the analysis of R- and S-enantiomers of mandelic acid (MA) in urine, using a chiral CP Chirasil-Dex-CB column. The enantiomers of MA were derivatised with isopropanol into their corresponding isopropyl esters and determined either directly with flame ionisation detection (FID) or after subsequent derivatisation of a hydroxy group with pentafluoropropionic anhydride with electron-capture detection (ECD). Both derivatisation steps proceeded with negligible inversion of enantiomers (<1%). The limit of detection of the FID determination was 8 and 5 mg/l for R-MA and S-MA, respectively and of the ECD determination 1 mg/l for both enantiomers. Repeatability (within-day precision) and reproducibility (day-to-day precision) was for both enantiomers below 7.5% for the FID and below 5.8% for the ECD analysis. The method was applied to urine of volunteers exposed to 105 and 420 mg styrene/m3 air. In the urine of the exposed volunteers, the S-enantiomer showed higher excretion compared to that of the R-enantiomer, with marked interindividual differences in excretion of both enantiomers.     

Malignant lymphoma of the stomach in association with inflammatory myofibroblastic tumor of the spleen. A case report

We report on a case of a 40-year-old male patient who underwent a gastrectomy because of a biopsy-proven large B-cell lymphoma of the stomach. On surgery, a nodule in the spleen also was noted. Grossly and microscopically, the two lesions were different: the tumor of the stomach appeared white-gray on the cut surface and was a centroblastic variant of diffuse large B-cell lymphoma. Histologically, one perigastric lymph node was involved. Grossly, the splenic nodule was gray-yellow and had a histological appearance of an inflammatory myofibroblastic tumor (IMT). The association between malignant tumor and IMT is rare. In such an association, the latter lesion most often has been reported in the spleen. As EBV may be involved in the genesis of both lymphoma and IMT, we tested both lesions for its presence using in situ hybridization, but the tests were negative. It remains to be verified whether the association between lymphoma and IMT is more than fortuitous.