Barrier Diamond-like Carbon Coatings on Polydimethylsiloxane Substrate

The plasma modification of polydimethylsiloxane (PDMS) substrates is one way to change their surface geometry, which enables the formation of wrinkles. However, these changes are very often accompanied by the process of restoring the hydrophobic properties of the modified material. In this work, the RF PACVD device (radio frequency plasma-assisted chemical vapor deposition) was used, with which the plasma treatment of PDMS substrates was carried out in argon, nitrogen, oxygen, and methane atmospheres at variable negative biases ranging from 100 V to 500 V. The obtained results show the stability of contact angles for deionized water only in the case of surfaces modified by diamond-like carbon (DLC) coatings. The influence of the applied production conditions on the thickness (between 10 and 30 nm) and chemical structure (ID/IG between 0.41 and 0.8) of DLC coatings is discussed. In the case of plasma treatments with other gases introduced into the working chamber, the phenomenon of changing from hydrophilic to hydrophobic properties after the modification processes was observed. The presented results confirm the barrier nature of the DLC coatings produced on the PDMS substrate.

Autoimmune hepatitis associated with the odour of fish food proteins: a causal relationship or just a mere association?

We present the case of a 15-year-old boy [HLA phenotype: A 1, 25 (10); B 18, 8; C 7; DR 17 (3), 6] with classic (type 1) autoimmune hepatitis presumably caused by a long-term exposure to the strong odour of food fed to a large number of tropical fish which that the boy kept in tanks in his bedroom. The boy presented with a history of recent symptoms of common cold, and a high cytomegalovirus-IgG titer, both known to activate proinflammatory cytokines. The patient's laboratory results and physical findings improved without specific treatment during his first stay in the hospital for several weeks, as well as when the thanks were removed from his bedroom while disease activity increased after his return home. This suggests that the association with fish food odour (putative volatile protein antigens) was not simply coincidental. Our patien's history is in agreement with the recently postulated pathomechanism of autoimmune hepatitis, according to which viral infections may trigger the disease in a genetically predisposed individuals persistently exposed to a constant antigenic stimulus, which results in ongoing allergic inflammation and finally develops into an immune process. The spontaneous remissions observed in our patient were characteristic of the natural course of autoimmune hepatitis and may reflect periods when he was not exposed to the eventually harmful effects of the odour of fish food proteins.

Autoimmune reactions in HBV and HCV

BACKGROUND

Hepatotropic viruses HBV and HCV are capable of triggering autoimmune reactions (AIH). The aim of the study was the assessment of clinical course of AIH in patients with HBV and HCV, and the revision of treatment methods employed in these cases.

MATERIAL AND METHODS

Among 120 patients with AIH and those qualified for antiviral therapy, 21 (17.5%) subjects were selected, including 16 with HCV (7 men and 9 women) and 5 with HBV (including 2 men and 3 women). AIH diagnosis was based on international criteria taking into account biochemical tests, autoantibodies and morphological picture of the liver. HBV infection was confirmed with the determination of HBV markers and HCV--with the presence of antiHCV and HCV RNA.

RESULTS

The duration of infection at AIH diagnosis was difficult to assess in patients with HCV. AIH was diagnosed when patients were qualified for antiviral treatment. Three patients displayed high anti-LKM1, 8--ANA and SMA, two pts--ANA, two pts--SMA, one pt--ANA + pANCA and one--SMA + pANCA. Nine patients did not show hyperproteinaemia, and hypergammaglobulinaemia was not observed in 2 patients. Six patients suffered from other immunity disorders--thrombocytopenia, vasculitis, arthritis, visceral lupus erythematosus. The diagnosis of chronic hepatitis was confirmed by morphological examinations in 15 patients. Ten subjects received adrenocortical hormones, 3 patients were treated with adrenocortical hormones and azathioprine, 4 received interferon and 3 received no treatment. All patients with HBV proved HBeAg(-). In these patients, AIH symptoms developed 5-18 years after the diagnosis of HBV infection. Liver biopsy confirmed the diagnosis in 4 patients. SMA was observed in 2 subjects, ANA and SMA--in the remaining patients. All the subjects manifested typical biochemical changes as well as high IgG values. Extrahepatic exponents of immune process were observed in 3 patients. Three subjects were treated with Encorton (Prednisone), while 2 patients received Encorton and Azathioprine.

CONCLUSIONS

Patients with HBV and HCV infections may manifest the features of AIH in the course of the disease, which requires careful attention while selecting treatment.

Mesangial proliferative glomerulonephritis in children

Over a ten year period 105 children with a histological diagnosis of a mesangial proliferative glomerulonephritis were diagnosed. Patients were divided into two groups according to their clinical presentation at the time of diagnosis. Ninety two children presented with nephrotic syndrome (NS) of whom 82 received steroid therapy. No response was observed in 26 children and in 56 remissions were short in duration and subsequent relapses were frequent. Eighty nine children with the nephrotic syndrome were treated with cyclophosphamide (CP) of whom 26 had a steroid resistant NS, 53 were steroid dependent and 10 were previously untreated. Eighty four entered remission with a mean duration of 46 months. Only 5 children did not respond to treatment with CP. No correlation could be found between the results of therapy and the degree of morphological changes on examination of renal biopsy. The second group consisted of 13 children presenting with a persistent nephritic syndrome and or proteinuria. These children were untreated and no progression of renal disease was observed after several years follow up.

The effect of adrenergic receptor blocking agents on arrhythmia caused by trauma

Experiments on animals have shown that blunt trauma to the anterior chest wall causes arrhythmia and conduction disturbances. In most cases nodal rhythm and ST segment elevation were observed. Microscopic examination disclosed myocardial damage in the vicinity of the atrioventricular node. Administration of alpha or beta adrenergic receptor blocking agents immediately before trauma failed to prevent arrhythmia and conduction disturbances, on the contrary, they became even more pronounced.

Effects of renal lymphatic occlusion and venous constriction on renal function

The effects of renal lymphatic occlusion or increased lymph flow due to renal vein constriction on renal function were investigated in rats. In each experiment, the renal lymphatics or vein of the left kidney were occluded or constricted and the right kidney served as a control. Occlusion of renal lymphatics caused renal enlargement, no change in glomerular filtration rate, a marked increase in urine flow and solute excretion without any change in urine osmolality, and enhanced urinary loss of urea, potassium, sodium and ammonium. Urea concentrations in medullary and papillary tissues were significantly elevated. Renal vein constriction caused renal enlargement and a marked drop in glomerular filtration rate, urine volume, urine osmolality and solute excretion. tissue concentrations of urea and potassium were decreased in the medulla and papilla and total tissue solute was significantly decreased in the papilla. The data indicate that in the rat, renal lymphatic occlusion traps urea in the medulla and induces a urea diuresis resulting in a large flow of normally concentrated urine. On the other hand, increased lymph flow secondary to renal vein constriction decreases medullary urea and potassium concentrations and papillary osmolality. These changes and the reduced glomerular filtration rate result in a small flow if dilute urine. Thus both renal lymphatic occlusion and enhanced lymph flow have a significant effect on renal function.