Role of histamine in the development of neurogenic inflammation of rat oral mucosa

The mechanism of development of neurogenic inflammatory reaction induced by the topical application of capsaicin was studied in the oral mucosa of rats with or without histamine antagonist pretreatment.The existence of a cholinergic component of the vasodilation was investigated using a muscarinic receptor antagonist.Results indicated that the neurogenic inflammatory increases in vascular permeability and blood flow are mediated in part by H₁-receptors. H₂-receptors and cholinergic pathways are apparently not activated in these processes.     

Visual-perceptual dysfunctions are possible endophenotypes of schizophrenia: evidence from the psychophysical investigation of magnocellular and parvocellular pathways

Visual information processing is impaired in schizophrenia patients and their biological relatives. The authors measured vernier thresholds in 72 schizophrenia patients, their 86 siblings, and 60 healthy control subjects. Subjects were asked to detect the direction of the horizontal displacement of 2 stimuli (left or right). During magnocellular (M) pathway tests, stimuli were dots with low contrast (5%) or counterphase-modulated gratings (25 Hz). For parvocellular (P) pathway tests, isoluminant blue-red dots with yellow-green background were used. Results revealed that patients with schizophrenia and their siblings were more impaired in M pathway conditions than in P pathway conditions. There was no color-specific impairment. The patients and their siblings displayed lower performances on tests of executive functions, psychomotor speed, and verbal memory compared with the controls. Visual-perceptual and neuropsychological data did not correlate. In conclusion, M pathway dysfunction is a potential endophenotype of schizophrenia.     

Differentiation of Rhizomucor species on the basis of their different sensitivities to lovastatin

The opportunistic pathogens Rhizomucor pusillus and Rhizomucor miehei may be agents of frequently fatal mycotic diseases. In the present study, the susceptibilities of 27 clinical and environmental isolates of R. miehei and R. pusillus to lovastatin under different culturing conditions were investigated. Most of the R. miehei strains grew at lovastatin concentrations as high as 64 to 128 microg/ml. In contrast, the inhibitory effect of lovastatin on all of the R. pusillus strains was evident at lovastatin concentrations as low as 1 to 2 microg/ml. A simple and reliable method for species-level differentiation, based on the significantly higher sensitivity of R. pusillus to lovastatin than that of R. miehei, was elaborated. According this, on malt extract agar containing 6 mug of lovastatin/ml, R. pusillus is not able to produce colonies, while R. miehei will form compact colonies.     

Functional and immunogenetic characterization of FcR-blocking antibody

The characteristics and functional importance of FcR-blocking antibodies and their production were investigated after immunization with whole blood, "buffy coat" and purified platelets. We studied the presence of FcR-blocking antibody in haemodialyzed, transfused patients waiting for kidney transplantation, and we found strong correlation between the blocking effect and better graft survival. We suggest that this blocking antibody does not attack FcR as primary target. Investigation of blocking activity of ten different immune sera on 50 healthy panel cells showed that target antigen has some polymorphic varieties. On basis of family studies it seems that the target antigen is not linked to HLA haplotype. The blocking effect of sera could be removed by absorption of CD8+ cells, B lymphocytes, platelets and granulocytes, but not with erythrocytes, monocytes, CD8- cells and NK cells.     

Differential sensitivity to Arg side chain modification of IL-1β binding to type I and type II receptors

The central role of interleukin-1 (IL-1) in several disease processes, including fever and inflammation, makes the characterization of ligand-receptor interaction of prime importance.The role of arginine (Arg) side chains of hr-IL-1 in receptor recognition was studied by the modification of Arg residues with the specific reagent 1,2-cyclohexanedione. It was found that chemical modification of Arg residues decreased the binding potential of IL-1 to type I receptor dramatically (by 230-fold) while the affinity to type II receptor was reduced only moderately (by 10-fold), with an insignificant reduction of the dissociation rate.These studies suggest that intact Arg side chains of IL-1 may be necessary for high affinity binding to type I IL-1 receptor, but have less importance for the interaction of IL-1 with type II IL-1 receptor.This observation may be useful in the study of type II IL-1 receptor-mediated biological responses and design of receptor-subtype specific ligands as well.     

Lack of correlation between impaired Interferon production and natural killer activity of lymphocytes in multiple sclerosis

Summary The ability of lymphocytes from patients with multiple sclerosis (MS) to produce Interferon (IFN-) in response to Newcastle Disease Virus (NDV) was studiedin vitro. The correlation between individual IFN- titers and natural killer (NK) cell activity and the presence of HLA system antigens associated with MS (B-7 and DRW-2) was also investigated.Lymphocytes from MS patients showed a significantly impaired capacity to synthesize IFN-in vitro when compared to lymphocytes from healthy donors (mean titers: 85.9 I.U. and 268.2 I.U., respectively). Marked differences in IFN- titers were observed in the group of MS patients.The production of IFN- by the patients' lymphocytes did not correlate with either the activity of NK cells or with their stimulation by exogenous IFN-. There was also no correlation between IFN- production by lymphocytes from MS patients and the presence or absence of B-7 and DRW-2 antigens.With 3 Figures     

Successful treatment of intractable gastric ulcers with acetazolamide

An open-controlled trial performed in gastric ulcer cases resistant to previous cimetidine, antacids, vitamin A and polyvinylbutylether therapy applied for at least 4 weeks. A group of 21 patients treated with acetazolamide was compared with 16 patients treated with cimetidine (controls). The period of management was 3 weeks. The number of healed patients (P = 0.009), the surfaces of ulcers after treatment (P = 0.0166) and the duration of complaints (P = 0.0003) differed favourably and significantly in the acetazolamide group as compared to the cimetidine group. In the acetazolamide group, however, several side effects (in 11 cases metabolic acidosis, in 9 cases tingling of extremities) were registered. Side effects were not seen in the control group. It is supposed that in the treatment of gastric ulcers a compound with less carbonic anhydrase inhibition but with the same or more cytoprotective effect would have wider clinical perspectives than acetazolamide alone.     

Analysis of the Equalization of Inverted Repeats and Neurovirulence Using a Pseudorabies Virus Mutant Strain Altered at the Ul/Ir Junction

A recombinant pseudorabies (Aujeszky’s disease) virus (PrV) designated as vE16lac was constructed by deleting a 3-kbp DNA segment spanning the junction of long and short components of the viral genome, and by replacing the deleted segment with a lacZ-expression cassette. The aim of constructing this mutant was (a) to determine whether the terminal repeat (Tr) can serve as a template for the regeneration of the internal repeat (Ir), and (b) whether this deletion causes a reduction in the neuroinvasiveness of the virus. To analyze the mechanism of equalization, revertant viruses were selected and structurally characterized from vE16lac infection of PK-15 cells, mice and pigs. Because all revertants acquired Ir sequences identical to that of the wild-type virus, the equalization process occurred using the Tr as a template to reconstitute the Ir. We also found that the recombinant virus vE16lac was virulent in both pigs and mice. The data are discussed in view of studies performed with similar PrV mutants by other authors (Rall et al., 1992, Dean and Cheung, 1995 and Dean et al., 1996). This revised version was published online in July 2006 with corrections to the Cover Date.     

Theory of mind and motion perception in schizophrenia

This study investigated the relationship between theory of mind (ToM) deficits and visual perception in patients with schizophrenia (N=52; 17 remitted and unmedicated) compared with healthy controls (N=30). ToM was assessed with the Eyes Test, which asked participants to choose which of 4 words best described the mental state of a person whose eyes were depicted in a photograph. Visual perception was evaluated with form and motion coherence threshold measurements. Results revealed that patients with schizophrenia (both remitted and nonremitted) showed deficits on the Eyes Test and the motion coherence task. ToM dysfunctions were associated with higher motion coherence thresholds and more severe negative symptoms. This suggests that ToM deficits are related to motion perception dysfunctions, which indicates a possible role of motion-sensitive areas in the pathophysiology of schizophrenia.