Propofol Attenuates Small Intestinal Ischemia Reperfusion Injury through Inhibiting NADPH Oxidase Mediated Mast Cell Activation.

Both oxidative stress and mast cell (MC) degranulation participate in the process of small intestinal ischemia reperfusion (IIR) injury, and oxidative stress induces MC degranulation. Propofol, an anesthetic with antioxidant property, can attenuate IIR injury. We postulated that propofol can protect against IIR injury by inhibiting oxidative stress subsequent from NADPH oxidase mediated MC activation. Cultured RBL-2H3 cells were pretreated with antioxidant N-acetylcysteine (NAC) or propofol and subjected to hydrogen peroxide (H2O2) stimulation without or with MC degranulator compound 48/80 (CP). H2O2 significantly increased cells degranulation, which was abolished by NAC or propofol. MC degranulation by CP further aggravated H2O2 induced cell degranulation of small intestinal epithelial cell, IEC-6 cells, stimulated by tryptase. Rats subjected to IIR showed significant increases in cellular injury and elevations of NADPH oxidase subunits p47(phox) and gp91(phox) protein expression, increases of the specific lipid peroxidation product 15-F2t-Isoprostane and interleukin-6, and reductions in superoxide dismutase activity with concomitant enhancements in tryptase and ß-hexosaminidase. MC degranulation by CP further aggravated IIR injury. And all these changes were attenuated by NAC or propofol pretreatment, which also abrogated CP-mediated exacerbation of IIR injury. It is concluded that pretreatment of propofol confers protection against IIR injury by suppressing NADPH oxidase mediated MC activation.

The interaction between oxidative stress and mast cell activation plays a role in acute lung injuries induced by intestinal ischemia-reperfusion.

BACKGROUND: Both oxidative stress and mast cells are involved in acute lung injuries (ALIs) that are induced by intestinal ischemia-reperfusion (IIR). The aim of this study was to further investigate the interaction between oxidative stress and mast cells during the process of IIR-induced ALI. MATERIALS AND METHODS: Thirty adult Sprague-Dawley rats were randomly divided into five groups: sham, IIR, IIR + compound 48/80 (CP), N-acetylcysteine (NAC) + IIR, and NAC + IIR + CP. All rats except those in the sham group were subjected to 75 min of superior mesenteric artery occlusion, followed by 2 h of reperfusion. The rats in the NAC + IIR and NAC + IIR + CP groups were injected intraperitoneally with NAC (0.5 g/kg) for three successive days before undergoing IIR. The rats in the IIR + CP and NAC + IIR + CP groups were treated with CP (0.75 mg/kg), which was administered intravenously 5 min before the reperfusion. At the end of the experiment, lung tissue was obtained for pathologic and biochemical assays. RESULTS: IIR resulted in ALI, which was detected by elevated pathology scores, a higher lung wet-to-dry ratio, and decreased expression of prosurfactant protein C (P < 0.05). Concomitant elevations were observed in the expression levels of the nicotinamide adenine dinucleotide phosphate oxidase subunits p47(phox) and gp91(phox) and the levels of hydrogen peroxide and malondialdehyde. However, superoxide dismutase activity in the lung was reduced (P < 0.05). The level of interleukin 6, the activity of myeloperoxidase, and the expression of intercellular adhesion molecule 1 were also increased in the lung. IIR led to pulmonary mast cell degranulation and increases in the plasma and pulmonary ß-hexosaminidase levels, mast cell counts, and tryptase expression in lung tissue. CP aggravated these conditions, altering the measurements further, whereas NAC attenuated the IIR-induced ALI and all biochemical changes (P < 0.05). However, CP abolished some of the protective effects of NAC. CONCLUSIONS: Oxidative stress and mast cells interact with each other and promote IIR-induced ALI.

The mechanism of sevoflurane preconditioning-induced protections against small intestinal ischemia reperfusion injury is independent of mast cell in rats.

The study aimed to investigate whether sevoflurane preconditioning can protect against small intestinal ischemia reperfusion (IIR) injury and to explore whether mast cell (MC) is involved in the protections provided by sevoflurane preconditioning. Sprague-Dawley rats exposed to sevoflurane or treated with MC stabilizer cromolyn sodium (CS) were subjected to 75-minute superior mesenteric artery occlusion followed by 2-hour reperfusion in the presence or absence of MC degranulator compound 48/80 (CP). Small intestinal ischemia reperfusion resulted in severe intestinal injury as demonstrated by significant elevations in intestinal injury scores and p47(phox) and gp91(phox), ICAM-1 protein expressions and malondialdehyde and IL-6 contents, and MPO activities as well as significant reductions in SOD activities, accompanied with concomitant increases in mast cell degranulation evidenced by significant increases in MC counts, tryptase expression, and ß-hexosaminidase concentrations, and those alterations were further upregulated in the presence of CP. Sevoflurane preconditioning dramatically attenuated the previous IIR-induced alterations except MC counts, tryptase, and ß-hexosaminidase which were significantly reduced by CS treatment. Furthermore, CP exacerbated IIR injury was abrogated by CS but not by sevoflurane preconditioning. The data collectively indicate that sevoflurane preconditioning confers protections against IIR injury, and MC is not involved in the protective process.

Cholesteatoma-associated pathogenicity: potential role of lysosomal exoglycosidases.

UNLABELLED: The enzymatic profile of lysosomal exoglycosidases in middle ear cholesteatoma has not been well known. The assessment of glycoconjugate catabolism may contribute to a better understanding of cholesteatoma pathogenesis. OBJECTIVE: The study aim was to evaluate catabolic processes of glycoproteins, glycolipids, and proteoglycans in cholesteatoma through outlining the concentration of N-acetyl-ß-hexosaminidase (HEX), ß-glucuronidase (GLUC), and ß-galactosidase (GAL) activity as well as in serum of cholesteatoma patients and healthy volunteers. STUDY DESIGN: Acquired cholesteatomas (n = 25) and normal retroauricular skin specimens (n = 25) were taken during surgery as well as serum from cholesteatoma patients and healthy volunteers. HEX, GAL, and GLUC activity was assessed on basis of p-nitrophenol release from derivatives of the substrate (HEX: N-acetylglucosamine i N-acetylgalactosamine, GAL from galactose, and GLUC from glucuronide). RESULTS: The mean concentration of activity of HEX 1142.39 pKat/ml, GAL 8.90 pKat/ml, and GLUC 14.06 pKat/ml was significantly higher compared with the concentration of enzyme activity in normal tissue: HEX 267.65 pKat/ml, GAL 3.44 pKat/ml, and GLUC 3.90 pKat/ml. In the serum of cholesteatoma patients, the mean concentration of enzyme activities were as follows: HEX 641.62 pKat/ml, GAL 4.55 pKat/ml, and GLUC 12.80 pKat/ml and were significantly higher compared with the concentration of HEX activity (215.75 pKat/ml), GAL (1.89 pKat/ml), and GLUC (5.51 pKat/ml) in the serum of the healthy control group. In cholesteatoma compared with the normal tissue, there is an increase of the glycoconjugate catabolism due to significantly higher concentration of HEX, GAL, and GLUC activity in cholesteatoma. Cholesteatoma causes systemic reaction due to the increase of HEX, GAL, and GLUC activity in patient serum.

Lysosomal exoglycosidases in serum and urine of patients with pancreatic adenocarcinoma.

Lysosomal exoglycosidases: N-acetyl-ß-D-hexosaminidase (HEX), ß-D-galactosidase (GAL), α-L-fucosidase (FUC) and α-D-mannosidase (MAN) modify oligosaccharide chains of glycoconjugates in endoplasmatic reticulum and/or Golgi apparatus and degrade them in lysosomes. In acid environment of lysosome, exoglycosidases degrade oligosaccharide chains of glycoproteins, glycolipids and glycosaminoglycans by eliminating single sugars from the edges of oligosaccharide chains. Neoplasms change biochemical processes in tissues and may significantly change the activity of many enzymes including the activity of lysosomal exoglycosidasses in serum and urine of persons with neoplasmatic diseases. The aim of the present paper was evaluation the activity of HEX, GAL, FUC and MAN in serum and urine of patients with pancreatic adenocarcinoma. Serum and urine samples were collected from 15 patients with adenocarcinoma of the pancreas and 15 healthy persons. The activity of lysosomal exoglycosidases was determined by the method of Marciniak et al. adapted to serum and urine of patients with adenocarcinoma of the pancreas. Our results indicate significant decrease in activity of GAL (p=0.037) in serum of patients with pancreatic adenocarcinoma, significant increase in activity of HEX (p<0.001) and FUC (p=0.027) in serum, and HEX (p=0.003) in urine, as well as significant decrease of FUC (p=0.016) and MAN (p=0.029) in urine o patients with adenocarcinoma of the pancreas, in comparison to the control group. Increase in activity of some lysosomal enzymes in serum and urine of pancreatic adenocarcinoma patients, may indicate on destruction of pancreatic tissue by pancreatic adenocarcinoma. Determination of the HEX, GAL, FUC and MAN in serum and urine may be useful in diagnostics of pancreatic adenocarcinoma.

N-acetyl-beta-D-hexosaminidase and its isoenzymes A and B in blood serum and urine, as a potential colon cancer markers.

BACKGROUND/AIMS: Evaluation of N-acetyl-beta-D-hexosaminidase (HEX), and its isoenzymes A (HEX A) and B (HEX B) activity in blood serum and urine as potential markers of colorectal cancer. METHODOLOGY: The study was performed in blood serum and urine of 32 patients with adenocarcinoma, 6 with adenocarcinoma mucinosum of the colon, and 20 healthy people. The activity of HEX, HEX A and HEX B was determined in blood serum and urine by spectrophotometric method of Marciniak et al. The concentration of CEA was determined in blood serum by immunoenzymatic method (MEIA). The concentration of protein was assessed by the Lowry method, whereas the concentration of creatinine in urine by the Jaffe method (without deproteinization). RESULTS: A significant increase in the concentration of HEX, HEX A and HEX B activity was proved in serum and urine of patients with colon adenocarcinoma. In patients with colon adenocarcinoma mucinosum, the higher activity of HEX was revealed in blood serum compared to healthy people, and the significantly higher activity of HEX and HEX B expressed as pKat/mg of creatinine, was found in urine. We observe a significant increase in the activity of HEX, HEX A and HEX B expressed in pKat/mg of creatinine was found in urine of patients bearing tumor of diameter 6.0-7.0 cm in comparison to patients with tumor of diameter 4.0-5.0 cm. CONCLUSIONS: The present study results suggest that determination of HEX, HEX A and HEX B activity in blood serum and urine may be used to detect colon cancer in its early stages. However, the use of HEX, HEX A and HEX B activity in oncological diagnostics requires further studies on a larger group of patients.

Effect of smoking on activity of N-acetyl-beta-hexosaminidase in serum and urine of renal cancer patients.

OBJECTIVES: To compare N-acetyl-beta-hexosaminidase (HEX) activity in the serum and urine of smokers as well as non-smokers with renal cancer, and healthy people. DESIGN AND METHODS: To assess hexosaminidase activity the level of p-nitrophenol released from p-nitrophenol derivatives was measured. RESULTS: The activity of enzyme was significantly higher in cancer group, with the highest activity in non-smokers. CONCLUSIONS: Cigarette smoking can inhibit, by the influence on HEX activity, catabolism of oligosaccharide chains in cancer tissues.

[Concentration of thyroid stimulating hormone and activity of N-acetyl-beta-D-hexosaminidase and its isoenzymes, in serum of patients with thyroid cancer]. / Stezenie hormonu tyreotropowego oraz aktywnosc N-acetylo-beta-D-heksozoaminidazy i jej izoenzymów A i B w surowicy chorych na raka tarczycy.

UNLABELLED: Thyroid cancer consists 1% of all malignant neoplasms. It is not known interrelationship between concentration of TSH in blood serum and condition of thyroid cancer. Thyroid cancer is difficult for diagnosis and differentiation. Therefore it is necessary to search for biochemical markers helpful in diagnostics of thyroid cancer. Significant increase in activity of N-acetyl-beta-D-hexosaminidase and its isoenzymes A and B in serum of patients with neoplasms of kidney and pancreas suggest approporiateness of evaluation of HEX and its isoenzymes in diagnostics of thyroid cancer. THE AIM: of the study--evaluation of TSH concentration and activity of HEX and its isoenzymes A and B, in serum of patients with thyroid cancer. MATERIALS AND METHODS: Blood was taken from 7 patients with thyroid cancer (6 men and 1 woman). Control consisted of 7 healthy men. In blood serum concentration of TSH was determined with immunoenzymatic method on analyzer Axsym of Abbott and expressed in microU/mL. The activity of HEX and its isoenzymes A and B was determined by method of Chatterjee et al., as modified by Zwierz et.al. Determination of HEX was performed on microplate reader ELX800 BIO-TEK. Activity of HEX, HEX A and B was expressed in pKat/mL, and specific activity in pKat/mg protein). Protein was determined by biuret method and results were expressed in mg/mL. RESULTS: Concentration of HEX A activity in serum of thyroid cancer patients is significantly higherin comparison to healthymen (p = 0.0191). Also specific activity of HEX A in serum of thyroid cancer patients is significantly higher in comparison to healthy men (p = 0.0393). CONCLUSIONS: 1. Determination of TSH concentration in serum of thyroid cancer before the operation may confirm euthyreosis. 2. Determination of HEX A activity in serum may be helpful in diagnostics of thyroid cancer.

Age dependence of serum beta-N-acetylhexosaminidase (NAG) activity.

Serum N-acetyl-beta-D-glucosaminidase (NAG; EC 3.2.1.30) is a hexosaminidase and may be a predictor of vascular injury, e.g., in infant respiratory distress syndrome, pneumonia, broncho-pulmonary dysplasia and necrotizing enterocolitis. To estimate the new diagnostic prospects we have modified our urinary NAG assay. In this sensitive colorimetric micro-assay, VRA-GlcNAc was used as a substrate. In the present study the age dependence of serum NAG activity was investigated in newborn babies, infants (1-24 months), children (2-18 years) and adults (19-80 years). Serum NAG activity was found to be age-dependent; it is higher in early childhood (11-59 U/l) but decreases to a constant value at the age of 1-2 years. After the age of 2 years it is similar to adults' NAG (10-30 U/l). In pediatrics age-matched reference ranges must be taken into consideration.

Hepatocyte growth factor pretreatment reduces apoptosis and mucosal damage after intestinal ischemia-reperfusion.

BACKGROUND/PURPOSE: Ischemia-reperfusion (IR) injury to the intestine can result in mucosal damage and cellular death. This study was designed to evaluate the protective effects of pretreatment with hepatocyte growth factor (HGF) on intestine after moderate IR injury. METHODS: Control animals (n = 7) received 48 hours of intravenous saline, and treatment animals (n = 7) received HGF (150 microg/kg/d). After 35 minutes of mesenteric artery occlusion and 120 minutes of reperfusion, serum and jejunal mucosa samples were obtained. Fluorometric assays were performed for hexosaminidase A (HEX A) and beta-glucuronidase (GLUC), enzyme markers of enterocyte necrosis. Apoptosis was quantified by the TUNEL method. Transcription of tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) was assessed by multiplex reverse transcription polymerase chain reaction (RT-PCR) Statistical analysis was performed using the Student's t test. RESULTS: After HGF pretreatment, HEX A and GLUC activities were reduced from 543 +/- 28 to 343 +/- 35 nmole/h/mL (P <.01) and 183 +/- 29 to 119 +/- 22 nmole/h/mL (P <.01), respectively. Pretreated animals had a reduced number of apoptotic cells per 10 crypts (33 +/- 11) compared with untreated rats (225 +/- 24) after IR injury (P <.01). Mean IFN-gamma band intensity was lower in HGF-pretreated animals (0.05 +/- 0.02) compared with controls (0.31 +/- 0.09; P <.05). CONCLUSIONS: Pretreatment with HGF reduces the severe crypt apoptosis and cellular necrosis after IR injury to the intestine. These data suggest that HGF may be beneficial in attenuating IR damage and thus may have significant clinical application.

Translocation of the tetraspanin CD63 in association with human eosinophil mediator release.

The tetraspanin CD63 (also known as LAMP-3) has been implicated in phagocytic and intracellular lysosome-phagosome fusion events. It is also present in eosinophils, with predominant expression on crystalloid granule membrane. However, its role in eosinophil function is obscure. We hypothesized that CD63 is associated with intracellular events involved in eosinophil activation and mediator release. We used a combination of confocal immunofluorescence microscopy, flow cytometry, and secretion assays, including beta-hexosaminidase, eosinophil peroxidase, and RANTES, to examine CD63 expression, intracellular localization, and its association with cell activation and mediator release. In resting eosinophils, CD63 immunoreactivity was localized to plasma and crystalloid granule membranes. In interferon-gamma (IFN-gamma)- or C5a/CB-stimulated cells (10 minutes), intracellular CD63 appeared to shift to the cell periphery and plasma membrane, while stimulation with a cocktail of interleukin-3 (IL-3)/IL-5/granulocyte-macrophage colony-stimulating factor induced the appearance of discrete intracellular clusters of CD63 immunoreactivity. IFN-gamma induced mobilization of CD63 to the cell periphery, which coincided with selective mobilization of RANTES prior to its release, implying CD63 association with piecemeal degranulation. Agonist-induced CD63 mobilization and cell surface up-regulation was associated with beta-hexosaminidase, eosinophil peroxidase, and RANTES release. Dexamethasone as well as genistein (a broad-spectrum inhibitor of tyrosine kinases) inhibited agonist-induced intracellular mobilization of CD63 and RANTES together with cell surface up-regulation of CD63 and mediator release. This is the first report of an association between CD63 mobilization and agonist-induced selective mediator release, which may imply the involvement of CD63 in eosinophil activation and piecemeal degranulation.

Relationships between serum markers of monocyte/macrophage activation in type 1 Gaucher's disease.

We studied 44 patients with type 1 Gaucher's disease (16 non-treated patients and 28 treated with enzyme replacement therapy). We measured serum levels of chitotriosidase (ChT), neopterin, angiotensin-converting enzyme (ACE), adenosine deaminase (ADA) and beta-hexosaminidase (Hex) and its major isoenzymes Hex A and Hex B. In the untreated group of patients, the increase in serum levels was ChT>neopterin>ACE> ADA>Hex, with all decreasing significantly in treated patients (p< 0.001). Highly significant correlations were obtained between the markers of monocyte/macrophage activation which were tested (p<0.001). However, partial correlations between serum Hex B (with Hex A constant) and ChT, ACE, neopterin and ADA did not reach statistical significance. This suggests that hepatocytes are the major cellular source of this isoenzyme. Similarly, partial correlation of ChT with neopterin, with the other variables constant, was not significant, which would suggest a different expression of these two markers in Gaucher's disease.

Complete analysis of the glycosylation and disulfide bond pattern of human beta-hexosaminidase B by MALDI-MS.

beta-hexosaminidase B is an enzyme that is involved in the degradation of glycolipids and glycans in the lysosome. Mutation in the HEXB gene lead to Sandhoff disease, a glycolipid storage disorder characterized by severe neurodegeneration. So far, little structural information on the protein is available. Here, the complete analysis of the disulfide bond pattern of the protein is described for the first time. Additionally, the structures of the N-glycans are analyzed for the native human protein and for recombinant protein expressed in SF21 cells. For the analysis of the disulfide bond structure, the protein was proteolytically digested and the resulting peptides were analyzed by MALDI-MS. The analysis revealed three disulfide bonds (C91-C137; C309-C360; C534-C551) and a free cysteine (C487). The analysis of the N-glycosylation was performed by tryptic digestion of the protein, isolation of glycopeptides by lectin chromatography and mass measurement before and after enzymatic deglycosylation. Carbohydrate structures were calculated from the mass difference between glycosylated and deglycosylated peptide. For beta-hexosaminidase B from human placenta, four N-glycans were identified and analyzed, whereas the recombinant protein expressed in SF21 cells carried only three glycans. In both cases the glycosylation belongs to the mannose-core- or high-mannose-type, and some carbohydrate structures are fucosylated.

Effect of collection, transport, processing and storage of blood specimens on the activity of lysosomal enzymes in plasma and leukocytes

This study was designed to evaluate the effect of different conditions of collection, transport and storage on the quality of blood samples from normal individuals in terms of the activity of the enzymes Beta-glucuronidase, total hexosaminidase, hexosaminidase A, arylsulfatase A and Beta-galactosidase. The enzyme activities were not affected by the different materials used for collection (plastic syringes or vacuum glass tubes). In the evaluation of different heparin concentrations (10 percent heparin, 5 percent heparin, and heparinized syringe) in the syringes, it was observed that higher doses resulted in an increase of at least 1-fold in the activities of Beta-galactosidase, total hexosaminidase and hexosaminidase A in leukocytes, and Beta-glucuronidase in plasma. When the effects of time and means of transportation were studied, samples that had been kept at room temperature showed higher deterioration with time (72 and 96 h) before processing, and in this case it was impossible to isolate leukocytes from most samples. Comparison of heparin and acid citrate-dextrose (ACD) as anticoagulants revealed that Beta-glucuronidase and hexosaminidase activities in plasma reached levels near the lower normal limits when ACD was used. In conclusion, we observed that heparin should be used as the preferable anticoagulant when measuring these lysosomal enzyme activities, and we recommend that, when transport time is more than 24 h, samples should be shipped by air in a styrofoam box containing wet ice

Effect of mesocaval interposition shunting and repeated sclerotherapy on blood levels of gastrointestinal regulatory peptides, amino acids, and lysosomal enzymes--a prospective randomised trial.

AIMS/BACKGROUND: Patients with liver cirrhosis and portal hypertension frequently exhibit a multitude of alterations of hormones and metabolism, but the relation of these alterations to liver function, degree of blood shunting, and hepatic encephalopathy remains unclear. METHODS: Twenty-four patients were randomised to mesocaval interposition shunt (MIS) and 21 patients to repeated sclerotherapy (ST). Several peptide hormones, amino acids and lysosomal enzymes were monitored during a 4 year follow-up period. RESULTS: Insulin and glucagon levels were elevated in the MIS group compared to pre-therapy levels, whereas the gastrin level was significantly higher in the ST group. Pancreatic polypeptide, somatostatin and vasoactive intestinal peptide levels were not affected by either treatment. The branched chain amino acids valine, leucine and isoleucine serum levels were all elevated after ST, and the arginine, proline and tyrosine levels were higher in the MIS group at follow-up. Other amino acids were not changed, neither were the lysosomal enzymes beta-hexosaminidase nor beta-glucoronidase during this longterm follow-up. CONCLUSION: MIS or repeated ST treatment only affected serum levels of hormones, amino acids and lysosomal enzymes to a limited extent. In this trial, the type of treatment had only a small influence on these parameters during long term follow-up.

Does general anesthesia affect sinusoidal liver cells as measured by beta-N-acetyl hexosaminidase serum activity level?

BACKGROUND/AIMS: General anesthesia causes temporary hypoxia of liver tissue, resulting in several metabolic changes. The purpose of this study was to explore whether the function of hepatic sinusoidal cells, especially the Kupffer and endothelial cells, are damaged following general anesthesia. METHODOLOGY: Liver sinusoidal cell (LSC) function was evaluated by means of measuring the serum level of activity of the lysosomal hydrolase beta-N-acetyl hexosaminidase before and 24 hours after general anesthesia in 20 patients who underwent orthopedic surgery. RESULTS: The only change in liver function which might be of clinical significance was a mild decline in the serum albumin level. CONCLUSIONS: Liver sinusoidal cells, especially Kupffer and endothelial cells, most probably remain undamaged after 1 to 5 hours of general anesthesia.

Assessment of autoimmunity in patients with chronic urticaria.

BACKGROUND: The etiology of chronic urticaria is unknown, and an exogenous allergen cannot be identified as the cause in the vast majority of subjects. Thus the concept has evolved that it might be autoimmune. OBJECTIVE: We have prospectively assessed sera obtained from 50 consecutive patients with chronic urticaria for the presence of autoantibodies that could be pathogenic. METHODS: We tested sera for their ability to release histamine from human basophils and to activate rat basophil leukemia cells that were transfected with the alpha subunit of the IgE receptor. We also tested selected sera for anti-IgE antibodies and for IgG anti-Fc epsilon RI alpha by Western blot. RESULTS: Sera from 38 of 50 patients with chronic urticaria released beta-hexosaminidase from transfected rat basophil leukemia cells, whereas only one of 20 control sera did so (p < 0.001); in 30 subjects this could be attributed to IgG anti- Fc epsilon RI alpha. When human basophils were used, sera from 20 of 50 patients with chronic urticaria released a significant quantity of histamine compared with one of 20 control subjects (p < 0.01). Six patients with chronic urticaria and one control subject had IgG anti-IgE. In selected sera we could demonstrate IgG anti-Fc epsilon RI alpha by Western blot; however, some sera are positive for histamine release but do not demonstrate such binding. CONCLUSION: A large fraction of patients with chronic urticaria have antibody directed to Fc epsilon RI alpha that is functional (60%). A smaller number have IgG anti-IgE (10%). A third group may also have circulating factors capable of activating basophils or mast cells of which the identity is unknown. Thus chronic urticaria may be autoimmune in origin.

Plasma tumor necrosis factor-a (TNF-a) levels in Gaucher disease.

Tumor necrosis factor-a (TNF-a) levels were measured in the plasma of patients with different types of Gaucher disease (GD) and patients with other lysosomal storage diseases. The highest TNF-a levels were observed in the most severe neuronopathic type of GD, exceeding those found in healthy individuals as well as patients with other lysosomal disorders. Type I GD cases showed a wide range of TNF-a levels ranging from normal to 2.5 x the highest control value. TNF-a is a pleiotropic cytokine produced mainly by activated macrophages. Our data suggest that it may play a role in the pathophysiology of GD disease.

[Evolutive neuroradiological alterations in Sandhoff's disease]. / Alteraciones neurorradiológicas evolutivas en la enfermedad de Sandhoff.

Sandhoff's disease is a severe form of gangliosidosis GM2 which presents in the first year of life, basically as progressive psychomotor retardation and/or a macular red cherry spot. Our patient presented the clinical picture characteristic of the disease. Diagnosis was confirmed by determining the activity of hexosaminidases A and B in serum and of beta-N-acetil hexosaminases in fibroblast culture. In view of the fatal prognosis of the disease, in 1991 a transplant of alogenic bone marrow (TMO) was carried out to try to replace the enzymes. This required exhaustive radiological follow-up to determine the possible neuro-radiological changes seen in this storage disease. Although treatment was not successful, the neuro-radiological findings may be of interest as perhaps being characteristic of the GM2 gangliosidosis: 1. Bilateral thalamic hyperecogenity in the cerebral ecography. 2. Differences between the thalamo-putamen densities due to bilateral homogeneous thalamic hyperdensity on the CT scan. 3. Thalamic hypointensity both on T2 sequences and in proton density on MR with the cerebral white matter being progressively affected. In conclusion, we suggest that bilateral symmetrical thalamic changes are an early finding which is probably specific to the GM2 gangliosidoses and may be useful from the point of view of carrying out more specific investigations in infants suspected of having a degenerative neurological disorder.