Effect of Liposomal Formulations and Immunostimulating Peptidoglycan Monomer (PGM) on the Immune Reaction to Ovalbumin in Mice

The adjuvant activity of liposomes and immunostimulating peptidoglycan monomer (PGM) in different formulations has been studied in mice model using ovalbumin (OVA) as an antigen. PGM is a natural compound of bacterial origin with well-defined chemical structure: GlcNAc-MurNAc-l-Ala-d-isoGln-mesoDpm(εNH₂)-d-Ala-d-Ala. It is a non-toxic, non-pyrogenic, and water-soluble immunostimulator. The aim of this study was to investigate the influence of different liposomal formulations of OVA, with or without PGM, on the production of total IgG, as well as of IgG1 and IgG2a subclasses of OVA-specific antibodies (as indicators of Th2 and Th1 type of immune response, respectively). CBA mice were immunized s.c. with OVA mixed with liposomes, OVA with PGM mixed with liposomes, OVA encapsulated into liposomes and OVA with PGM encapsulated into liposomes. Control groups were OVA in saline, OVA with PGM in saline, and OVA in CFA/IFA adjuvant formulation. The entrapment efficacy of OVA was monitored by HPLC method. The adjuvant activity of the mixture of OVA and empty liposomes, the mixture of OVA, PGM, and liposomes and PGM encapsulated with OVA into liposomes on production of total anti-OVA IgG was demonstrated. The mixture of PGM and liposomes exhibited additive immunostimulating effect on the production of antigen-specific IgGs. The analysis of IgG subclasses revealed that encapsulation of OVA into liposomes favors the stimulation of IgG2a antibodies, indicating the switch toward the Th1 type of immune response. When encapsulated into liposomes or mixed with liposomes, PGM induced a switch from Th1 to Th2 type of immune response. It could be concluded that appropriate formulations of antigen, PGM, and liposomes differently affect the humoral immune response and direct the switch in the type of immune response (Th1/Th2).     

Age-Dependent Effects of ELF-MF on Oxidative Stress in the Brain of Mongolian Gerbils

The aim of study was to investigate the effects of extremely low frequency magnetic field (ELF-MF; 50 Hz; 0.1, 0.25 and 0.5 mT) on oxidative stress in the brain of 3- (adult) and 10-month-old (middle-aged) gerbils. Nitric oxide (NO) level, superoxide (O₂ ^?) production, superoxide dismutase (SOD) activity, and index of lipid peroxidation (ILP) were measured in the forebrain cortex, striatum, hippocampus, and cerebellum immediately and 3 days after cessation of 7-day exposure. In all gerbils, ELF-MF significantly increased oxidative stress in all tested brain regions. This effect was correlated with the value of magnetic induction and was higher in middle-aged gerbils. Three days after cessation of exposure, the values of examined parameters were closer to control levels. In adult gerbils, the effect of ELF-MF of 0.1 mT on NO level, O₂ ^? production and SOD activity was almost fully disappeared, and ILP was at the control level regardless of the value of magnetic induction. In middle-aged gerbils, the effect of ELF-MF was still present but to a lesser degree than those observed immediately after cessation of exposure. These findings pointed out the ability of ELF-MF to induce age- and magnetic induction-dependent modification of oxidative stress in the brain.     

The first ferrocene analogues of muramyldipeptide

The two structurally interesting bioorganometallic analogues of muramyldipeptide (MDP) with potential immunomodulatory activity were synthesized starting from the O-protected N-acetylmuramic acid (MurNAc), l- or d-Ala and 1′-aminoferrocene-1-carboxylic acid (Fca). They were fully characterized by IR, ¹H NMR, ¹³C NMR and CD spectroscopy as well as by FD mass spectrometry.     

Infantile spasms in children with Down syndrome

Down syndrome (DS) is the most common genetic cause of mental retardation. It is estimated that 5-13% of persons affected by DS have seizures. Infantile spasms are the most common type of seizures and usually are well controlled with steroids and antiepileptic drugs. We present 11 children at the age of 3 years and 4 months to 10 years and 7 months with DS and infantile spasms, treated at Children's Hospital Zagreb from January 2000 until July 2009. Infantile spasms began at the age of 5 to 10.5 months in 10 children, in one child at the age of 16 months. Only one child had perinatal risk factors for the development of IS. Changes in EEG correlated to hypsarrhythmia. Infantile spasms were treated initially with antiepileptic drugs, most often with valproic acid. Treatment was inefficient in 10/11 patients. After application of ACTH, infantile spasms stopped between 7 and 15 days in 6 patients, until 28th day in 4 patients. Hypsarrhythmia vanished in all children. During follow-up period (2 years and 7 months to 9 years and 5 months) none of the children developed another type of seizures. No major epileptogenic changes were registered in EEG. Antiepileptic therapy was discontinued in 4 children (aged 4 years and 2 months to 5 years). In this group is the boy who died of heart failure. Infantile spasms associated with DS are categorized into symptomatic group. The existence of cerebral pathology and delayed psycho-motor development precedes occurrence of seizures. It is possible to achieve good control of seizures and disappearance of hypsarrhythmia with application of ACTH and antiepileptic drugs.     

Clinical characteristics of patients with spondyloarthritides and HLA-B27 positive antigen

The aim of this study was to present our experiences in diagnosing spondyloarthritides (SpA), and to list the most common clinical features of HLA-B27 positive patients. The study included 65 HLA-B27 positive patients with confirmed diagnosis of ankylosing spondylitis (AS) and psoriatic arthritis (PsA) who were analyzed between 2009 and 2010 in Clinic of Internal Medicine in Osijek. The diagnosis of seronegative spondyloarthritides was based on the ASAS (Assessment in AS Working Group) classification criteria for axial and then supplemented with ASAS criteria for peripheral SpA and was confirmed by radiological techniques. For diagnosing the ankylosing spondylitis (AS), there have been applied the modified New York criteria. Radiological criteria for definite sacroiliitis according to the modified New York criteria is bilateral sacroiliitis, grade 2-4 (> or = 2) or unilateral sacroiliitis, grade 3-4. For diagnosing the psoriatic arthritis (PsA), there were used CASPAR diagnostic criteria. Other features of SpA are defined within the existing classification criteria. HLA-B27 antigen was determined by direct immune-fluorescence technique using flow cytometer. The average age of patients was 50.34 years, of whom 27 female (41.53%), 38 male (58.46%). Duration of illness was 15.79 years on average. With 75.38% of patients, there had been determined the diagnosis of AS; 24.62% of patients had the diagnosis of PsA. The most common clinical characteristics that patients had were: inflammatory back pain (pain Inflammation along the lumbosacral spine), peripheral arthritis, intermittent pain in the gluteus, sacroiliitis, enthesitis, uveitis, dactilitis.     

Tumor markers in breast cancer--evaluation of their clinical usefulness

Breast cancer is the most common neoplasm affecting women in the Western world. Many studies are still conducted with the purpose of finding markers that could be used for early diagnosis and/or serve as possible reliable prognostic or predictive parameters, but with conflicting results. At present, no markers are available for an early diagnosis of breast cancer For surveillance of patients with diagnosed breast cancer the most widely used serum markers are CA 15-3 and CEA which, in combination with other clinical parameters, could have clinical significance. The most useful and clinically important tissue-based markers in breast cancer are estrogen and progesterone receptors, used as a basis for hormonal therapy, and HER-2 receptors, essential in selecting patients for the treatment with Herceptin. New or potentially new markers for breast cancer include BRCA1 and BRCA2 genes for selecting patients at high risk of developing hereditary breast cancer, as well as urokinase plasminogen activator and inhibitor for assessing prognosis in lymph node-negative patients. Results of tumor and patient genetic analyses including their clinical evaluation will enable application of more individualized and personalized approach in diagnosis and therapy of breast cancer patients.     

Diurnal variation in airborne pollen concentrations of the selected taxa in Zagreb, Croatia

The number of individuals allergic to plant pollen has recently been on a constant increase. The knowledge of diurnal distribution and abundance of allergenic pollen types, their patterns and response to source position and weather is useful to correlate hay fever symptoms with the presence of allergenic pollen in the atmosphere. The aim of this study was to determine diurnal distribution of total airborne pollen, pollen of particular allergenic taxa, possible variation in diurnal pollen distribution at measuring sites placed at different heights, and effect of some meteorological parameters on airborne pollen concentrations. A 7-day Hirst-type volumetric pollen trap was used for pollen sampling. Qualitative and quantitative pollen analysis was performed under a light microscope (magnification x400). Total pollen of all plant taxa (Ambrosia sp., Betula sp., Cupressaceae, Urticaceae, Poaceae, Quercus sp., Fraxinus sp., Alnus sp., Corylus sp., Populus sp., Pinus sp., Picea sp.) observed showed a regular diurnal distribution at both sampling sites in both study years, with a rise in the pollen concentration recorded after 4.00 a.m. and 6.00 a.m., respectively. The peak pollen concentration occurred between 12.00 a.m. and 4.00 p.m., and the lowest diurnal pollen concentrations were recorded overnight. About 50% of the 24-h pollen concentration were released to the atmosphere between 10.00 a.m. and 4.00 p.m. The timing and size of diurnal peaks were closely related to high temperature, low humidity and south-west maximum wind direction.     

Growth modulation of human cells in vitro by mild oxidative stress and 1,4-dihydropyridine derivative antioxidants

Reactive oxygen species and lipid peroxidation products are not only cytotoxic but may also modulate signal transduction in cells. Accordingly, antioxidants may be considered as modifiers of cellular redox signaling. Therefore, the effects of two novel synthetic antioxidants, analogues of 1,4-dihydropyridine derivatives, cerebrocrast and Z41-74 were analysed in vitro on human osteosarcoma cell line HOS, the growth of which can be modulated by lipid peroxidation. The cells were pretreated with either cerebrocrast or Z41-74 and afterwards exposed to mild, copper induced lipid peroxidation or to 4-hydroxynonenal (HNE), the end product of lipid peroxidation. The results obtained have shown that both antioxidants exert growth modulating effects interfering with the lipid peroxidation. Namely, cells treated with antioxidants showed increased metabolic rate and cell growth, thereby attenuating the effects of lipid peroxidation. Such biomodulating effects of cerebrocrast and Z41-74 resembled growth modulating effects of HNE, suggesting that the antioxidants could eventually promote cellular adaptation to oxidative stress interacting with redox signaling and hydroxynonenal HNE-signal transduction pathways. This may be of particular relevance for better understanding the beneficial role of hydroxynonenal HNE in cell growth control. Therefore, cerebrocrast and Z41-74 could be convenient to study further oxidative homeostasis involving lipid peroxidation.     

Isolation,characterisation and phagocytic function of human macrophages from human peripheral blood

Molecular Biology Reports - Macrophages are among the most important cells of the immune system. Among other functions, they take part in almost all defense actions against foreign bodies and...