Myasthenia gravis patients with anti-MuSK antibodies.

In myasthenia gravis (MG) patients without detectable anti-acetylcholine receptor (anti-AChR) antibody, referred to as seronegative myasthenia gravis patients, there is a variable proportion of patients with antibodies against the muscle-specific kinase (MuSK). MuSK antibodies were found in 8 (29.6%) of our 27 patients with generalized MG without anti-AChR antibodies.

Apolipoprotein H (apoH)-dependent autoantibodies and apoH protein polymorphism in selected patients showing lupus anticoagulant activity.

Apolipoprotein H (apoH) is considered to be a necessary cofactor for the binding of certain antiphospholipid antibodies to anionic phospholipids. Some apoH-dependent antiphospholipid antibodies also exert lupus anticoagulant (LA) activity, which seems to depend on antiphospholipid antibody epitope specificity. The aim of this study was to evaluate whether the presence of less frequent apoH alleles may induce structural or conformational changes in these "LA-dependent" regions that may initiate more frequent autoimmune responses in subjects.

Apolipoprotein H genetic variability in the population of Krk Island, Croatia.

Apolipoprotein polymorphisms are emerging as suitable markers for the study of the formation of human populations. In contrast to the data available for apolipoprotein E, the data regarding apolipoprotein H (protein, apoH; gene, APOH) variations are only beginning to accumulate. By blood plasma isoelectric focusing and immunoblotting, we analyzed the distribution of apoH phenotypes in 397 individuals (192 males; 205 females) from seven villages of an autochthonous population of the eastern Adriatic island of Krk.

Cerebrospinal fluid complement activation in neurological diseases.

Laser nephelometry (LN) is a rapid and very sensitive method for simultaneous determination of albumin, immunoglobulins, C3c and C4 in diluted serum and paired cerebrospinal fluid (CSF) samples. It is very useful in routine analyses. Determination of C3c and C4 covers classical as well as alternative pathways of complement activation.

Comparison of the values of basic fibroblast growth factor determined by an immunoassay in the sera of patients with traumatic brain injury and enhanced osteogenesis and the effects of the same sera on the fibroblast growth in vitro.

In patients with severe traumatic brain injury, the early healing of fractures is accompanied by hypertrophic callus formation or heterotopic ossifications, which might even result in ankylosis of the affected joints. Analysis of the sera of patients with traumatic brain injury revealed post-traumatic dynamic changes of basic fibroblast growth factor immunoreactivity, similar to those observed during fracture healing associated with enhanced osteogenesis. The aim of this study was to determine whether such changes in basic fibroblast growth factor concentrations could be related to the phenomenon of enhanced osteogenesis.

Interleukin 4, IgG and oligoclonal IgG in aqueous humor of cataract patients.

We measured interleukin 4, total IgG, IgG-albumin relative concentration ratio, and oligoclonal IgG in aqueous humors of patients with uncomplicated senile cataracts and cataracts complicated by previous uveitis of unknown etiology. The values of all mentioned parameters are significantly elevated in aqueous humors of patients with complicated cataracts. The possible implications of our findings are briefly discussed.

Precipitation and characterization of an aluminosilicate from AlCl3-Na2SiO3-HCl in serum, of interest for Alzheimer disease.

A precipitation experiment was performed with human serum to model aluminosilicate formation in brains of patients with Alzheimer disease. Aluminum and (or) silicate ions were added to serum in a 1:2 molar ratio at pH 7.4.

Diagnostic significance of methemoglobin determination in colorless cerebrospinal fluid.

The presence of various heme derivatives can be demonstrated spectrophotometrically in colorless cerebrospinal fluid (CSF). Because of the high sensitivity of the method, it may detect compounds that reflect a "traumatic tap" rather than a disease process. However, the presence of methemoglobin excludes the possibility of a hemorrhagic CSF being caused by traumatic lumbar puncture.

Gangliosides in the human brain development and aging.

In this study, brain gangliosides in prenatal and postnatal human life were analyzed. Immunohistochemically, the presence of "c"-pathway of gangliosides (GQ1c) in embryonic brain was only recorded at 5 weeks of gestation. Biochemical results indicated a twofold increase in human cortex ganglioside concentration between 16 and 22 weeks of gestation.

Gangliosides of human cerebrospinal fluid in various neurologic diseases.

Simultaneous profile determination and quantification of human cerebrospinal fluid (CSF) gangliosides in various neurologic diseases (n = 71) was examined. Gangliosides were extracted with methanol/chloroform from clinically available amounts of CSF (4-5 ml), then separated and quantified by high-performance thin-layer chromatography (HPTLC) and direct densitometry. Based on chromatographic comparison with standards, the percentage of lipid-bound NeuAc positive fractions in 'normal' CSF samples were: GM1 (II3 NeuAc-GgOse4Cer) (3%); GD3 (II3 NeuAc2-Lac-Cer) (4%); GD1a (IV3 NeuAc, II3 NeuAc-GgOse4 Cer) (15%); X1 (3%); GD1b (II3(NeuAc)2-GgOse4 Cer) (16%); X2 (4%); GT1b (IV3 NeuAc, II3(NeuAc)2-GgOse4-Cer) (40%); and GQ1b (IV3(NeuAc)2, II3(NeuAc)2-GgOse4-Cer (15%).

Determination of gangliosides in human cerebrospinal fluid by high-performance thin-layer chromatography and direct densitometry.

A method for the separation and quantification of a complex ganglioside mixture from a clinically available amount (5 ml) of human cerebrospinal fluid (CSF) is described. After reduction of the CSF volume by ultrafiltration, gangliosides are extracted with methanol/chloroform, then separated and quantified by high performance thin layer chromatography (HPTLC) and direct densitometry. For purification of crude ganglioside extract, the method of choice was microdialysis against water.

Measurement of intraocular IgA and IgM synthesis and filtration through the blood-aqueous barrier in cataract patients.

The authors have tested two formulas by means of which the filtrated and the intraocularly (intrathecally) synthesized fraction of particular protein can be distinguished. The laser nephelometric method was applied to determine the serum (IgG, IgA, IgM, C3, albumin), aqueous humor (IgA, IgM, albumin) and CSF (IgG, IgM, C3, albumin) protein values in 42 subjects to test two models in physiological conditions. It was confirmed that the best results were achieved using the formula after Stambuk.

Study of serum and cerebrospinal fluid enzymes in diagnosis and differential diagnosis of cerebrovascular diseases.

In the paper are presented the results of total enzyme activity investigation: GOT, GPT, LDH and CPK, and of the CPK isoenzymes in the cerebrospinal fluid of 148 examinees and in the serum of 67 examinees with an acute stroke, who were treated at the Intensive Care Unit of the Department of Neurology and Institute of Neuropathology, Clinical Medical center "Rebro". The aim was to determine the reliability of the applied methods in the diagnosis of cerebrovascular diseases, particularly in the differential diagnosis of cerebral hemorrhage, ischemia and subarachnoidal hemorrhage. The highest frequency of pathologic findings of the tested enzymes in the whole group of patients with CVA was obtained in the determination of the CPK total activity assessment, then followed the assessments of LDH activity, isoenzyme CPK profile, GOT and finally GPT activity.

Detection of IgG oligoclonal bands in unconcentrated CSF by isoelectric focusing in ultrathin polyacrylamide gel, direct antiserum immunofixation and silver nitrate staining.

Isoelectric focusing of proteins in ultrathin polyacrylamide gel (0.4 mm), followed by direct immunofixation with monospecific antisera and silver nitrate staining, is a highly specific, sensitive and simple method for the detection of oligoclonal IgG in unconcentrated CSF samples. The ultrathin polyacrylamide gels have several advantages, i.

Detection of oligoclonal IgG bands in unconcentrated CSF in multiple sclerosis and other neurological diseases by isoelectric focusing on ultrathin-layer polyacrylamide gel immunofixation and silver staining.

Isoelectric focusing of proteins (IEF) in ultrathin-layer polyacrylamide gel (0.4 mm, PAG), followed by direct immunofixation with monospecific antiserum and silver staining, is a highly specific, sensitive and simple method for the demonstration of oligoclonal IgG in unconcentrated cerebrospinal fluid (CSF) samples (5-10 microliters). For the present method, the optimal concentrations of IgG in CSF samples are about 0.