Pore structure evolution in andesite rocks induced by freeze-thaw cycles examined by non-destructive methods.

In this paper, we compare the values of petrophysical properties before and after 100 freeze-thaw (F-T) cycles, as well as recorded length change behaviour and temperature development on a vacuum-saturated fractured andesite rock sample taken from the Babina Quarry in Slovakia using a specially-constructed thermodilatometer, VLAP 04, equipped with two HIRT-LVDT sensors. We also used non-destructive visualization of the rock pore network by µCT imaging in order to study the development of the pore structure and fracture network in pyroxene andesites during the freeze-thaw process. The results show that the andesite rock samples, due to good fabric cohesion, low porosity, and low pore interconnection, showed good resistance against frost-induced damage. However, it must be stated that the main process causing disintegration of this type of rock is fracture opening, which is caused by internal stresses induced by water-ice phase transition. The overall residual strain recorded after 100 F-T cycles was not significant, however, the increase of 31 pp in volume of the fracture showed us that repeated freezing and thawing can lead to long term deterioration in terms of subcritical crack growth in brittle-elastic solids like pyroxene-andesite rocks.

[Lyme borreliosis--the great imitator]. / Lymská borelióza--velký imitátor.

Three different pathomorphological findings were presented in patients with seropositive borreliosis. Skin biopsy, cytology of joint synovial fluid and imprint cytology of bulbar conjunctiva were included. Skin vasculitis as well as pleocytosis of synovial fluid were found in accordance with literature, the inclusions in conjunctival imprint were unusual.

[Beta-2-microglobulin and ankylosing spondylitis]. / Beta-2-mikroglobulín a akylozujúca spondylitída.

Serum beta-2-microglobulin was examined by radioimmunoassay in 103 patients with ankylosing spondylitis and 111 healthy blood-donors. Statistically significant difference between the group of patients and healthy individuals was found related to increased levels of this protein in patients with ankylosing spondylitis. Furthers correlation analysis of beta-2-microglobulin in patients with ankylosing spondylitis and chosen clinical and humoral parameters of the disease activity was performed. Positive, statistically significant correlation with erythrocyte sedimentation rate, plasmatic gamma globulins, duration of morning stiffness and global activity of the disease was proved. Higher levels of beta-2-microglobulin in patients with ankylosing spondylitis could be attributed to activation of monocyte macrophages system in subpopulation of cytotoxic T-lymphocytes, which might be the evidence of the involvement of cytotoxic-T cell mechanisms in the pathogenesis of this disease.

[The effect of colchicine and its derivatives on the activity of enzyme markers of T-lymphocytes]. / Vplyv kolchicínu a jeho derivátov na aktivitu markerových enzýmov T-lymfocytov.

Colchicine and its less toxic derivatives (demecolcine and deacetyl colchicine), in dependence on the concentration in the incubation medium, inhibited the activity of adenosine deaminase in the lymphocytes. All the three substances increased the level of cyclic adenosine monophosphate which has the ability of influencing the proliferation of T-lymphocytes. Colchicine and its derivates also inhibited the activity of purine nucleooxidophosphorylase, which, similarly as adenosine deaminase, is a marker enzyme of T-lymphocytes. The results obtained lead to the assumption that the mentioned preparations inhibit the function of T-lymphocytes.

[HLA antigens and primary prolapse of the mitral valve]. / HLA antigény a primárny prolaps mitrálnej chlopne.

The authors present results of investigation of antigens of the HLA system in primary mitral valvular prolapse. The investigated group of patients was formed by 23 not related patients with primary mitral valvular prolapse. (15 women, 8 men, aged 18-55 years) where HLA antigens of loci A, B and C were assessed. They found a significantly increased frequency of antigen HLA-B35 in the patients (56.52%), as compared with the population (18.33%, x2 = 18.48, Pcorr less than 0.01). The measure of the observed relationship is expressed by the relative risk value--RR = 5.81. The difference in the frequency of the other HLA antigens was not statistically significant.

Caplan's syndrome.

Caplan's syndrome is characterized by the presence of seropositive rheumatoid arthritis associated with a specific form of pneumoconiosis, consisting of multiple, well-defined homogeneous rounded opacities on chest X-ray. It develops especially in miners working in anthracite coal-mines and in persons exposed to silica and asbestos. In the development of the disease, genetic factors are considered to play an important role by influencing immunological reactivity of the organism exposed to various heteroantigens.

[Antibodies to Klebsiella pneumoniae in ankylosing spondylitis]. / Protilátky proti Klebsiella pneumoniae pri ankylozujúcej spondylitíde.

The authors investigated the incidence of antibodies against Klebsiella pneumoniae and E. coli in a group of patients with ankylosing spondylitis and in a group of healthy controls in all main immunoglobulin classes. The results revealed that in patients with ankylosing spondylitis there is a significantly higher incidence of specific antibodies of class IgA against Klebsiella pneumoniae and E. coli. This supports the thesis on the aetiopathogenetic interrelationship between enteric bacteria and the development of ankylosing spondylitis.

The effect of allopurinol on lysosomal enzyme release.

Values of released enzymes from PMNL under resting conditions and after phagocytic stimulation in non-treated patients with gout were increased in comparison with healthy controls and hyperuricemic patients without joint involvement. Allopurinol, given to gout-patients for 3 weeks, had an inhibitory effect on PMNL lysosomal enzyme release from which was also observable after stimulation by opsonized zymosan. Similar results were obtained in experiments in vitro. The 1 hr preincubation of isolated polymorphonuclear leukocytes with allopurinol in concentrations from 0.01 mM-1 mM resulted in a dose-dependent decrease of enzymes released into extracellular space.

Joint hypermobility in primary mitral valve prolapse patients.

Twenty-seven patients with echocardiographic evidence of primary mitral valve prolapse (MVP) were tested for the presence of joint hypermobility using the criteria of Beighton and Horan. In the examined group, joint hypermobility was found in 14 patients (52%). This occurrence was statistically significant. In patients with simultaneous occurrence of MVP and articular hypermobility we have found a number of pathologic arthrologic manifestations, such as arthralgias, synovitic reactions, distortions, low back pain, and others. In patients with articular hypermobility, there were increased functions of antigen B 35.

[Uric acid levels of the serum of healthy persons and patients with various rheumatic diseases]. / Soderzhanie mochevoi kisloty v syvorotke krovi u zdorovykh lits i pri nekotorykh revmaticheskikh zabolevaniiakh.

Serum uric acid levels were investigated in a series of 1715 subjects. Of them 596 were patients with inflammatory rheumatic disorders, 162 gout patients, 236 with osteoarthrosis, 79 with systemic lupus erythematosus or diffuse scleroderma and 642 healthy subjects. On analyzing the results, very high uricemia values were found in the gout patients. Increased uricemia values were observed is patients with psoriatic arthritis and diffuse connective tissue disorders (systemic lupus erythematosus and diffuse scleroderma). Hyperuricemia was found in psoriatic arthritis, rheumatoid arthritis and in nosological entities classified under diffuse connective tissue disorders in 5.6 to 10.1% of patients. In the healthy examinees hyperuricemia was recorded in 3.8% of the cases.