Fibroblast-Like Synovial Cells in Rheumatoid Arthritis--the Impact of Infliximab on Hexosaminidase Activity.

BACKGROUND: The effect of multiple infusions of infliximab (INF), a chimeric anti-tumor necrosis factor alpha antibody, on the concentration of hexosaminidase (HEX) activity in a synovial cell culture derived from human synovial inflamed fluid obtained from patients suffering from rheumatoid arthritis (RA) has been evaluated. OBJECTIVES: The aim of this study was to prove INF efficacy in RA. MATERIAL AND METHODS: Inflamed synovial fluid was taken from RA patients (a study group) and patients who had undergone knee trauma within 7 days (a control group). The following solutions of infliximab were used: 40, 60 and 140 µg/mL. Determination of the concentration of HEX activity in cell cultures was performed after 24, 48, 72 and 96 h of infliximab administration. To identify synoviocytes in cell culture immunohistochemical staining with vimentin and pancytokeratin was performed. RESULTS: A predominance of fibroblast-like synovial cells has been observed in the study group. In the control group the concentration of HEX activity without adding infliximab to the cell culture was 283.00 nkat/mL. After 96 h of incubation with infliximab, the concentrations of HEX activity in cultured synoviocytes according to infliximab doses of 40, 60 and 140 µg/mL were respectively: 280.00, 271.50 and 293.50 nkat/mL. In the study group, the concentration of HEX activity without adding infliximab to the cell culture was 542.27 nkat/mL. The final concentrations of HEX activity of cultured fibroblast-like synovial cells measured after 96 h of incubation with infliximab were: 471.72, 498.27 and 556.72 nkat/mL, according to infliximab doses of 40, 60 and 140 µg/mL. In all groups (besides the infliximab concentration of 140 µg/mL after 96 h of incubation), the level of concentration of HEX activity was significantly higher in the study group compared to the control group, irrespective of infliximab concentration and time of infliximab incubation. CONCLUSIONS: Infliximab changes the concentration of HEX activity depending on the drug dose and time of administration.

Glycoconjugate markers of joint diseases.

A number of different types of glycoconjugate are found associated with joint tissue and fluids, comprising glycoproteins, glycolipids and glycosaminoglycans. Oligosaccharide chains of glycoconjugates are degraded by exoglycosidases, and the dominant exoglycosidase found in human blood, synovial fluid, the synovial membrane and chondrocytes of articular cartilage is HEX (N-acetyl-ß-hexosaminidase). HEX is localized mostly intracellularly in synovial cells. Serum activity of HEX may be used to monitor the course and efficiency of treatment of Lyme arthritis, and activity of HEX, above 10 µkat/kg of protein in the synovial fluid, suggests rheumatoid disease. There is a shortage of HEX inhibitors able to penetrate synoviocytes, so the development of drugs which inhibit synthesis and/or the activity of HEX will be a promising field for future investigations.

[The pirymethamine influence on hexosoaminidase gene expression in synovial cell culture--preliminary report]. / Wplyw pirymetaminy na ekspresje genów heksozoaminidazy w synowiocytach in vitro--doniesienie wstepne.

UNLABELLED: Inflammation process is leading to increasing of synovial fluid and value of its pressure. Moreover, the impairment of vascular flow within synovial membrane and increased permeability of blood vessels were described. The activity of lysosomal enzymes, such as N-acetyl-beta-glucosaminidase (HEX), was increased in patients with rheumatoid arthritis in comparison to health synovial fluid. It is supposed, that HEX takes part in joint destruction. The using of HEX inhibitors in synovial cell culture and evaluation of HEX mRNA expression before and after the adding of inhibitor may contribute in showing the new ways of understanding pathogenetic pathways of motion organ disorders. THE AIM of the study was to evaluate the expression of HEXA and HEXB genes in the synovial cell culture derived from human synovial inflammatory fluid obtained from patients suffered from rheumatoid arthritis. MATERIAL AND METHODS: The inflamed synovial fluid was taken from patients suffered from rheumatoid arthritis. The following solutions of potential inhibitor--pyrimethamine were used: 20 microg/ml, 10 microg/ml, 3 microg/ml and 1.5 microg/ml. Two separate control groups were established: control group 1 where only 0.6% of ethanol was added to the synovial cell culture; control group 2 where only 0.5% DMSO was added to the synovial cell culture. The relative quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR) was carried out. RESULTS. The difference in HEXA and HEXB expression was observed in synoviocytes obtained in synovial cell culture. Five time higher relative HEXA expression was determined after applying 3 microg/ml of pirymethamine compared with the control 1. The highest concentration of pirymethamine (10 and 20 microg/ml) caused the least elevation of HEXA expression. The slight decreased of HEXB expression was observed under the concentration of pirymethamine: 1.3 and 3 microg/ml. CONCLUSIONS. Pyrimethamine contributes to regulating the HEX gene expression from synovial cells. The change in gene expression level is dependent on the concentration of the pirymethamine. Our preliminary data don't let us establish the concentration of pyrimethamine that may significantly inhibit HEXA and HEXB expression. Further study may be conducted to put new insight into the pathogenesis of joint destruction in the course of rheumatoid arthritis.

Catabolism of glycoconjugates in chronic otitis media with cholesteatoma.

Chronic ear disease with cholesteatoma is characterized by an intrusion of keratinizing stratified squamous epithelium into the middle ear manifesting bone resorption at the interface of the perimatrix. The aim of our study was to investigate the markers of a catabolic process associated with several chronic inflammatory states. We assessed the level of catabolism of glycoconjugates in assays of cholesteatoma extracts, quantifying two lysosomal exoglycosidases: alpha-mannosidase (alpha-MAN) and beta-galactosidase (beta-GAL). Cholesteatomas (n = 15) and normal adult postauricular skin served as controls (n = 15) were collected from the patients during surgery owing to chronic otitis media. To assess exoglycosidase activity, release of p-nitrophenol from p-nitrophenol derivatives of alpha-mannose and beta-galactose was used. In 13 of 15 specimens, we observed significantly higher activity of investigated enzymes in cholesteatoma tissue compared with control tissue (postauricular skin). The mean activity of alpha-MAN from the cholesteatoma cells was 1.76 +/- 1.10 nkat/g wet tissue and 0.61 +/- 0.21 nkat/g wet tissue in the control probes. The mean activity of beta-GAL from the cholesteatoma cells was 1.77 +/- 1.07 nkat/g wet tissue and 0.87 +/- 0.20 nkat/g wet tissue in the control probes. Catabolic reactions involving glycoproteins, glycolipids, and proteoglycans may play a role in cholesteatoma-related bone resorption. The present data indicating that the lysosomal exoglycosidases alpha-MAN and beta-GAL are significantly and consistently elevated suggest the need to further correlations assessment between levels of alpha-MAN and beta-GAL and cholesteatoma behavior. Further research should also evaluate the relative importance of these particular exoglycosidases in manifesting bone resorption in considering the spectrum of identified inflammatory mediators.

Role of N-acetyl-beta-d-hexosaminidase in cholesteatoma tissue.

Cholesteatoma is a destructive disease characterized by the progressive expansion of keratinizing squamous epithelium in the middle ear and mastoid, and chronic inflammatory reaction of the subepithelial connective tissue. N-Acetyl-beta-d-hexosaminidase (HEX) catalyzes the release of terminal non-reducing N-acetyl-d-hexosamine residues acting on glucosides and galactosides in glycoproteins, G(M2)-gangliosides and glycosaminoglycans (GAGs). In this study the activities of HEX were measured in cholesteatoma tissue and in normal skin to demonstrate a possible role of HEX in bone resorption in the area adjacent to cholesteatoma. Cholesteatomas (n = 21) and normal adult retroauricular skin (controls, n = 21), were collected from patients during surgery due to chronic otitis media. In 20 of 21 specimens a significantly higher activity of HEX was observed in cholesteatoma tissue compared with that in normal skin. Mean release of HEX from the activated cells was 68.55 +/- 30.77 nkat/g wet tissue in cholesteatoma and 31.79 +/- 10.02 nkat/g wet tissue in skin specimens. It may explain the process of bone resorption in the area adjacent to cholesteatoma, i.e. ossicles or temporal bone. This study suggests that drugs inhibiting HEX activity, such as iminocyclitols, may be useful in cholesteatoma treatment.

Hearing threshold shift measured by otoacoustic emissions after shooting noise exposure in soldiers using hearing protectors.

OBJECTIVE: The aim of the study was to assess the influence of short-term impulse noise to temporary threshold shift in soldiers using hearing protectors. STUDY DESIGN AND SETTING: The study included 80 subjects with correct tympanic membrane and thresholds measured by pure-tone audiometry less than 20 dB. There were two groups: 40 soldiers protected during shooting and 40 young males who didn't shoot. TEOAE were performed by ILO 292 Echoport Otodynamics device 3 to 5 minutes before shooting and 2 minutes and 1, 2, and 3 hours after shooting. RESULTS: Short-term exposure to impulse noise generated by five gunshots from the rifle kbk AKMS hasn't induced temporary threshold shift of hearing for chosen frequencies in soldiers using hearing protectors. Spectral analysis for chosen frequencies revealed that measurement reproducibility, stimuli level, and probe stability appeared to be comparable and repeatable. CONCLUSION: Our results show that the use of hearing protectors safeguarded against impulse noise. SIGNIFICANCE: The use of earmuffs is strongly recommended because they seem to sufficiently attenuate shooting noise.

Hexosaminidase as a new potential marker for middle ear cholesteatoma.

OBJECTIVES: The study aim was to investigate the activities of hexosaminidase (HEX) in cholesteatoma tissue compared with that in normal skin. DESIGN AND METHODS: The enzyme activities were determined using the Chatterjee et al. method in the modification of Zwierz et al. in cholesteatoma and skin. RESULTS: Significantly higher activity of hexosaminidase was observed in cholesteatoma tissue compared with the skin. CONCLUSIONS: Hex may be considered as a new pathogenetic factor in that destructive lesion.

[Analysis of hearing threshold shift measured by otoacoustic emissions in soldiers after shooting with use hearing protectors]. / Analiza przesuniecia progu slyszenia za pomoca emisji otoakustycznej u zolnierzy wykonujacych strzelanie w ochronnikach sluchu.

BACKGROUND: The aim of the study was to assess the influence of short-term impulse noise on the size of temporary threshold shift in soldiers using hearing protectors during exposure. MATERIAL AND METHODS: The study covered 80 subjects with normal tympanic membrane and thresholds measured by pure tone audiometry lower than 20 dB. There were two groups: I--composed of 40 soldiers protected during shooting and II--comprised 40 young males which did not shoot (controls). Transient evoked otoacoustic emissions were performed by an ILO 292 Echoport Otodynamics device 3-5 min before shooting and 2 min, 1, 2 and 3 h after shooting. RESULTS: The results showed that post-exposure changes in soldiers who used ear-muffs were not significant. CONCLUSION: The use of hearing protectors is strongly recommended because most of them seem to sufficiently attenuate impulse noise from firearms.

Temporary hearing threshold shift measured by otoacoustic emissions in subjects exposed to short-term impulse noise.

OBJECTIVES: The aim of the study was to assess the influence of short-term impulse noise on the size and dynamics of temporary threshold shift, which precedes permanent threshold shift, i.e. noise-induced hearing loss. It was hoped to use the findings for preventive activities. MATERIALS AND METHODS: The study included 80 healthy subjects (160 ears), aged 19-23 years, divided into two groups: group I comprised 40 recruit soldiers put to the shooting training, and group II consisted of 40 young male controls. All subjects had to show normal hearing with pure tone audiometric thresholds between 10-15 dB. Transient evoked otoacoustic emission (TOAE) measurements were performed by ILO 292 Echoport Otodynamics device 3-5 min before shooting and then 2 min, 1, 2 and 3 h, respectively after shooting. In group II the time intervals were similar. RESULTS: It was found that the gunshot impulse noise from the kbk AKMS rifle caused temporary hearing threshold shift (TTS) at 1, 2, 3, 4 and 5 kHz frequencies of 1.07, 0.96, 1.41, 0.88 and 1.25 dB SPL, respectively. TIS turned out to be maximum at 4 and 5 kHz and minimum at 1 and 2 kHz. CONCLUSIONS: Short-term impulse noise generated by the rifle gunshots induces rather small temporary threshold shift of hearing. Anyhow, considering possibilities of different weapon noises in the military environment as well as various sources of industrial impulse noise, the usage of hearing protectors should be highly recommended.