The origin of a large apparent tortuosity factor for the Knudsen diffusion inside monoliths of a samaria-alumina aerogel catalyst: a diffusion NMR study.

Pulsed field gradient (PFG) NMR was applied to measure tortuosity factors for carbon dioxide diffusion in the Knudsen and gas regimes inside monoliths of a samaria-alumina aerogel catalyst, a high porosity material containing micropores in addition to meso- and macropores. The apparent tortuosity factor obtained from PFG NMR measurements for the Knudsen diffusion in the meso- and macropores of the catalyst has an unexpectedly large value of approximately 6 if carbon dioxide adsorption in the micropores and other types of surface adsorption sites of the catalyst is ignored. At the same time, the corresponding apparent tortuosity factor in the gas regime was found to be around 2. Application of a proposed model which describes fast molecular exchange between the surface adsorption sites and the main pore volume of the catalyst yields corrected tortuosity factors which depend only on the pore system geometry. Using this model, the corrected tortuosity factors were found to be around 2 for both diffusion regimes, in agreement with the expectations based on a high porosity of the studied catalyst.

Production of cytokines during interaction of peripheral blood mononuclear cells with autologous ovarian cancer cells or benign ovarian tumour cells.

Cytokines produced by tumour and immune cells may play a significant role in a modulation of immune cells response against tumour. We investigated an ability of peripheral blood mononuclear cells (PBMC) of patients with early and advanced stages of ovarian cancer and from non-cancer patients to produce various cytokines in the presence or absence of autologous ovarian cancer (OC) cells or benign ovarian tumour (BOT) cells. Activated PBMC of patients with advanced stage of cancer produced slight amount of interferon gamma (IFN-gamma) and what's more, the production of IFN-gamma was decreased in the presence of OC cells. PBMC of patients with ovarian cancer or benign ovarian tumour generated comparable amounts of interleukin 6 and 10 (IL-6, IL-10), and transforming growth factor beta1 (TGF-beta1). PBMC of the patients with cancer produced higher amount of tumour necrosis factor alpha (TNF-alpha) than PBMC of non-cancer patients. We demonstrated here that the reciprocal contact of OC cells from advanced cancer with autologous PBMC altered the direction of produced cytokines and leads to the down-regulation of IFN-gamma and TNF-alpha as well as to up-regulation of immunosuppressive (IL-10, TGF-beta1) and pro-inflammatory (IL-6) cytokines production.

Ovarian cancer cells modulate human blood neutrophils response to activation in vitro.

In cancer, numerous cells of both innate and adaptive immune systems are activated. Polymorphonuclear neutrophils are potent effector cells of inflammation that are an important component of tumour development and progression. The important signalling proteins that are involved in neutrophil functions are extracellular signal-regulated kinases 1/2 (ERK1/2). We investigated the reactive oxygen species (ROS) production, adhesive ability and CD11b/CD18 adhesion molecule expression on neutrophils isolated from peripheral blood of ovarian cancer patients and the in vitro response of these cells to stimuli and direct contact with ovarian cancer cells isolated from tumour. We found that functional activities of neutrophils isolated from patients with advanced stages of ovarian cancer (FIGO III/IV) were intensified in comparison to neutrophils isolated from healthy female volunteers. Neutrophils of cancer patients produce higher amounts of ROS in response to stimuli than those of control group. Unstimulated neutrophils of patients possess higher expression of CD11b/CD18 molecule that is accompanied by increased adhesive ability of these cells. Our results reveal that augmented functional activities of neutrophils may result from the intensification of ERK1/2 kinases phosphorylation. We found that interactions with ovarian cancer cells modulate neutrophil functions as a result of cell-to-cell direct contact. We conclude that ovarian cancer cells affect pro-inflammatory activities in neutrophils via influence of signalling pathways in response to stimuli. Our results suggest the possibility that neutrophils responding to contact with cancer cells contribute to the progression and metastatic potential of tumour cells.

Amperometric responses of CYP2D6 drug metabolism nanobiosensor for sertraline: a selective serotonin reuptake inhibitor.

Sertraline is selective serotonin reuptake inhibitor drug marketed as Zoloft by Pfizer and used mainly for the treatment of depression, anxiety and obsession. A number of side effects are associated with the use of the drug including gastrointestinal complaints, nervousness and sexual dysfunction. This means that a reliable fast method (such as biosensing) for determining sertraline metabolic profile of patients is essential for adequate dosing. Nanobiosensor for the determination of sertraline biotransformation was prepared with cytochrome P450-2D6 (CYP2D6) and poly(8-anilino-1-napthalene sulphonic acid) nanotubes (90 nm in diameter and 600-800 nm in length) potentiodynamically deposited on gold. The biosensor gave a linear response over the concentration range of 0.2 and 1.4 microM with a sensitivity value of 0.301 microA/microM and a detection limit of 0.13 microM. The nanobiosensor exhibited substrate inhibition response profile for sertraline biotransformation at high concentrations. Analysis of the Michaelis-Menten region of the nanosensor response curve for sertraline gave an apparent Michaelis-Menten constant (K(m)) value of 0.75 microM, which is higher than the peak plasma concentration (C(max)) value of 0.55 microM, thereby making the sensor suitable for sertraline determination in serum.

Signal transduction pathways affected by nitric oxide donors during neutrophil functional response in vitro.

OBJECTIVE AND DESIGN: We investigated the intracellular signalling pathways by which nitric oxide (NO) donors: diethylamine/NO (DEA/NO) and 3-morpholinosydnonimine (SIN-1) regulate the functional response of human neutrophils to activating stimuli. METHODS: The phosphorylation and nitration of signalling proteins, cyclic GMP level, neutrophil respiratory burst and adhesive activities and CD11b/CD18 molecule expression on neutrophils in the presence and absence of soluble guanylate cyclase inhibitors were determined. RESULTS: NO donors showed strong inhibitory effect on activated neutrophils. NO donors nitrated the tyrosine residues in signalling proteins causing a decrease in tyrosine phosphorylation and neutrophils response to activation. Diethylamine/NO employed cyclic GMP as a signalling molecule in its action on neutrophils, whereas peroxynitrite anion donor affected neutrophil functions in a cGMP-independent manner. Moreover, we observed that peroxynitrite anion can overcome the nitric oxide molecule action. CONCLUSIONS: We conclude that each NO donor depending on its concentration and chemical nature may act on different elements of neutrophil signalling pathways capable of inducing distinct neutrophil functions.

Validity of the Rey Visual Design Learning Test in primary and secondary school children.

The Rey Visual Design Learning Test (Rey, 1964, cited in Spreen & Strauss, 1991, Wilhelm, 2004) assesses immediate memory span, new learning, delayed recall and recognition for nonverbal material. Two studies are presented that focused on the construct validity of the RVDLT in primary and secondary school children. In the first study, primary school children performed the RVDLT and the Biber Figural Learning Test, as well as the WISC-R Block design Test, Boston Naming Test, and the Trailmaking Test, to assess discriminant validity. In the second study, the age range was expanded and the subtest Visual Reproductions of the Wechsler Memory Scale with a Delayed recall phase was used to assess the construct validity. A test for visual-motor integration and a test for attention, concentration, and speed of information processing were also added to complete the test battery for assessing discriminant validity. Moderate to high correlations were found between scores on the RVDLT and the tests used to assess construct validity. The correlational pattern of RVDLT scores and the scores on the discriminant tests is discussed.

The use of X-ray fluorescence (XRF) analysis in predicting the alkaline hydrothermal conversion of fly ash precipitates into zeolites.

The use and application of synthetic zeolites for ion exchange, adsorption and catalysis has shown enormous potential in industry. In this study, X-ray fluorescence (XRF) analysis was used to determine Si and Al in fly ash (FA) precipitates. The Si and Al contents of the fly ash precipitates were used as indices for the alkaline hydrothermal conversion of the fly ash compounds into zeolites. Precipitates were collected by using a co-disposal reaction wherein fly ash is reacted with acid mine drainage (AMD). These co-disposal precipitates were then analysed by XRF spectrometry for quantitative determination of SiO(2) and Al(2)O(3). The [SiO(2)]/[Al(2)O(3)] ratio obtained in the precipitates range from 1.4 to 2.5. The [SiO(2)]/[Al(2)O(3)] ratio was used to predict whether the fly ash precipitates could successfully be converted to faujasite zeolitic material by the synthetic method of [J. Haz. Mat. B 77 (2000) 123]. If the [SiO(2)]/[Al(2)O(3)] ratio is higher than 1.5 in the fly ash precipitates, it favours the formation of faujasite. The zeolite synthesis included an alkaline hydrothermal conversion of the co-disposal precipitates, followed by aging for 8h and crystallization at 100 degrees C. Different factors were investigated during the synthesis of zeolite to ascertain their influence on the end product. The factors included the amount of water in the starting material, composition of fly ash related starting material and the FA:NaOH ratio used for fusing the starting material. The mineralogical and physical analysis of the zeolitic material produced was performed by X-ray diffraction (XRD) and nitrogen Brunauer-Emmett-Teller (N(2) BET) surface analysis. Scanning electron microscopy (SEM) was used to determine the morphology of the zeolites, while inductively coupled mass spectrometry (ICP-MS), Fourier transformed infrared spectrometry (FT-IR) and Cation exchange capacity (CEC) [Report to Water Research Commission, RSA (2003) 15] techniques were used for chemical characterisation. The heavy and trace metal concentrations of the zeolite products were compared to that of the post-synthesis filtrate and of the precipitate materials used as Si and Al feed stock for zeolite formation, in order to determine the trends (increase or decrease) and ultimate fate of any toxic metals incorporated in the co-disposed precipitated residues.

Nitric oxide generation from hydroxylamine in the presence of neutrophils and in the cell-free system.

Conversion of hydroxylamine (HA) to nitric oxide (NO) has been studied in the presence or absence of human neutrophils with or without myristate acetate phorbol (PMA), catalase (CAT), hydrogen peroxide (H2O2), and superoxide dismutase (SOD) and nitric oxide synthase (NOS) inhibitors. The generation of NO from HA in the presence of neutrophils was higher than in the cell-free system. We found that catalase did not influence the nitrite generation from HA in the cell-free system and in the presence of neutrophils. The H2O2 enhanced the NO generation from HA in the presence of neutrophils only. When catalase and H2O2 were added together, a high increase of NO generation from HA in both systems was observed. The addition of SOD decreased whereas addition of PMA enhanced the NO generation from HA in the presence of neutrophils. The presented data show the possible role of oxygen radicals in the decomposition of HA to NO. The addition of NOS inhibitors to the culture of neutrophils decreased the generation of nitrite from HA. Our results suggest that NO generation from HA, which is an intermediate in NO production from L-arginine, may be supported by an enzymatic pathway in which cellular NO synthase is involved.

Seizures associated with therapeutic doses of venlafaxine and trimipramine.

OBJECTIVE: To report a patient having a first-time seizure after receiving venlafaxine and trimipramine for depression. CASE SUMMARY: A 25-year-old white woman with chronic depression was treated with venlafaxine 150 mg/d and trimipramine 50 mg/d. Eleven days after increase of the trimipramine dosage to 100 mg/d, she was hospitalized because of seizures suggesting a secondary generalized grand-mal episode. The electroencephalogram showed a pathologic pattern with several generalized epileptiform discharges. Because of suspected drug-induced seizures, both antidepressants were stopped. After antidepressant drug cessation, the patient was symptom free and had no further seizure episodes within the following 12 months of follow-up. No other potential cause for the seizure episode could be identified. DISCUSSION: Both venlafaxine and trimipramine have been associated with seizures, mainly after overdose. Venlafaxine-associated seizures at therapeutic doses have not been reported in the literature. We hypothesize that a pharmacodynamic or pharmacokinetic drug interaction between venlafaxine and trimipramine involving the CYP2D6 isoenzyme may have played a role in inducing the seizures. CONCLUSIONS: Clinicians should be aware of the proepileptogenic effect of venlafaxine and trimipramine at therapeutic doses and that this combination may eventually increase the risk of seizures.

A new species of Swingleus (Monogenea: Gyrodactylidae) from the mummichog Fundulus heteroclitus, in the Delaware Bay.

Swingleus ancistrus n. sp. (Monogenea: Gyrodactylidae) is described from the skin and fins of Fundulus heteroclitus from Canary Creek Marsh, Lewes, Delaware. Subsequent records from New Jersey, Maryland, Virginia, and North Carolina are reported. Swingleus ancistrus is differentiated from S. polyclithroides, the only other species of the genus, primarily by its size, haptoral morphology, host, and locality. Swingleus ancistrus is larger in almost every dimension and exhibits a distinct notch on the anterior border of the opisthaptor, and several features of the haptoral anatomy and peduncular bar are unique. The prevalence of infection in hosts collected from the type locality in August was 100%. The maximum number of S. ancistrus recovered from a single host was 134. The average intensity of infection was 24 S. ancistrus per host from the type locality.

[Production of reactive nitrogen and oxygen intermediates in human granulocytes and monocytes during internalization of live BCG bacilli]. / Powstawanie aktywnych form azotu i tlenu w ludzkich granulocytach i monocytach pochlaniajacych zywe pratki BCG.

The production of nitric oxide (NO) and reactive oxygen intermediates in granulocytes and macrophages from healthy volunteers, infected in vitro with live Bacille Calmette-Guerin (BCG) mycobacteria, was estimated. Significant differences in the biochemical reactions induced by BCG bacilli in granulocytes and monocytes are described. The activity of phagocytes was also investigated in the cultures with cytokines: IFN-gamma, TNF-alpha, GM-CSF, IL-4.

The production of nitric oxide and tumor necrosis factor by murine macrophages infected with mycobacterial strains differing by hemolytic activity.

In this study, we compared the secretion of nitric oxide (NO) and tumor necrosis factor (TNF-alpha) by murine macrophages infected in vitro with hemolytic or unhemolytic mycobacteria isolates. We observed that unhemolytic mycobacteria induced more intensive NO production by macrophages and were more susceptible to bactericidal effect of mononuclear phagocytes than hemolytic mycobacterial strains. In contrast, the high-virulence hemolytic isolates induced significantly stronger TNF-alpha production by infected macrophages than the low-virulence unhemolytic bacilli.

Investigation of influence of Proteus mirabilis LPS polysaccharide part on the murine immune cells activation.

The biological activities were investigated of Proteus mirabilis lipopolysaccharides (LPSs) and their fragments, namely, the induction of nitric oxide (NO) and interleukin 1 (IL-1) synthesis by murine macrophages and the proliferation of murine spleen cells. The O-specific polysaccharide (F1), core oligosaccharide (F2) and lipid A were as effective as intact LPS in stimulating murine macrophages to produce NO. IL-1 synthesis was also induced by all studied types of endotoxins (S, Ra, Re) and partial structures, however F1, F2 and lipid A fractions required the presence of serum. In contrast to LPS, the O-specific polysaccharide, core oligosaccharide and lipid A were not able to induce the blast response of murine non-adherent splenocytes.

The comparison of some biological activities of lipopolysaccharides obtained from smooth and rough Proteus mirabilis strains.

The biological activity of lipopolysaccharide (LPS) obtained from Proteus mirabilis smooth and rough strains was investigated. The tested endotoxins (differing in polysaccharide chain lenght) were isolated from wild S1959 strain as well as from its rough mutants Ra and Re. Induction of tumor necrosis factor-alpha (TNF-alpha), and nitric oxide production as well as activation of complement system by lipopolysaccharide are the pathophysiological reaction in a host response to gram-negative bacteria. In this study, it was found that S (S1959), Ra (R110) and Re (R45) chemotypes of LPS similarly induced the human neutrophils to release TNF-alpha. In contrast none of the LPS stimulated the neutrophils to synthesis of nitric oxide regardless of doses used and culture time. Te Re form of LPS showed the strongest anticomplementary activity.

Listeria monocytogenes infection in mice treated with pentoxifylline.

The course of L. monocytogenes infection was followed in mice treated with pentoxifylline (POF), a known inhibitor of endogenous tumor necrosis factor (TNF) formation. Administration of POF caused a delay in L. monocytogenes elimination which was probably related to a reduction the listericidal activity of macrophages and to an attenuation of delayed type hypersensitivity (DTH) to Listeria antigens. In spite of this, some POF-treated mice were protected from lethal effects of virulent L. monocytogenes bacteria.

[Neutrophil activation by bacterial endotoxins]. / Aktywacja neutrofilów przez endotoksyny bakteryjne.

The endotoxin (lipopolysaccharide, LPS), major component of Gram-negative bacteria cell wall, activate numerous types of cells, neutrophils included. The chemical compositions of polysaccharide (O-specific polysaccharide and core oligosaccharide) and hydrophobic lipid A parts of LPS are presented. The bindings of LPSs to neutrophils resulted in signal transduction and neutrophils activation. Neutrophils, under LPS stimulation, generate oxygen radicals, nitric oxide and other components of inflammatory processes.

Listeria monocytogenes infection in pregnant mice: abnormalities in the function of non-adherent accessory light density dendritic cells.

Pregnant A/J mice were found to be more susceptible to the lethal effect of Listeria monocytogenes bacteria than virgin females. However, during the first four days of post-infection there was no difference in the elimination of Listeria from the spleens of pregnant and virgin mice. This suggests that the increase in the susceptibility of pregnant mice to pathogenic activity of L. monocytogenes was related to the diminution in Listeria-specific cellular reactions. Indeed, we found that non-adherent light density dendritic cells (DCs) from pregnant mice showed a marked reduction in the ability to form clusters with L. monocytogenes immune T lymphocytes and it is known that cell cluster formation between antigen presenting cells (APC) and responding T cells is required for antigen recognition as well as for cell proliferation. DCs from pregnant mice also demonstrated the decrease and an instability in the expression of H-2 class II molecules which play a crucial role in the recognition of exogenous antigens. The abnormalities demonstrated in the function of the light density dendritic cells from the spleens of pregnant mice could compromise cellular reactions to L. monocytogenes bacteria possibly resulting in increased susceptibility of pregnant mice to experimental listeriosis.

[Feto-maternal immunoregulation]. / Immunoregulacja matczyno-plodowa.

One of the great mysteries in modern immunology is how extraembryonic membranes escape rejection by maternal immune response, although they express paternal genes/anti-genes which should stimulate allogenic recognition and rejection. Generally, two theories try to explain the pregnancy phenomenon. One of the emphasizes the role of immunosuppressive reactions in the protection of the fetus. On the contrary, the "immunotropism" theory insists on the importance of mother's immune response to paternal antigens of the conceptus. Moreover, the last years abound in discoveries on molecules regulating cell-cell interactions at the level of the initiation and effector stage of the immune response. The best examples of such molecules could be extracellular matrix proteins, integrins, interleukins and various growth factors. The discussion on those molecules as regards their role in the protection of the fetus was the main aim of this article.

Specific cellular and humoral reactions as markers of Listeria monocytogenes infections.

The purpose of the study was to test in experimental mouse model if some immunological parameters could be helpful in recognizing Listeria infections. Delayed type hypersensitivity (DTH) and ELISA tests carried out with soluble fractions of L. innocua (serotype 6a) or L. monocytogenes (serotype 4b) seem to be useful in detecting listeriosis at an early stage. Although crude antigen fractions were used in this study, very weak only nonspecific DTH reactions were observed in unifected animals and they could be easily distinguished from the DTH reactions developed by the animals infected with Listeria. However, genetic factors influenced specific anti-listerial reactivity and it was especially observed when DTH test was used as an indicator of Listeria infection. In contrast to DTH and ELISA tests, determination of antibodies active in agglutination or passive haemagglutination assay seem useless in detecting listeriosis at an early stage of infection.

The relation of sleep complaints to respiratory symptoms in a general population.

Based on data obtained from the Tucson Epidemiologic Study of Chronic Lung Disease that included body weight, questionnaire responses, and spirometry, we found that among subjects with no respiratory symptoms, 28.0 percent reported insomnia (difficulty initiating or maintaining sleep) and 9.4 percent reported daytime sleepiness. Among subjects with respiratory symptoms, cough and/or wheeze, the rates of sleep complaints increased. With one symptom, 39.1 percent reported insomnia and 12.4 percent reported daytime sleepiness. With both symptoms, the rates were 52.8 percent and 22.8 percent, respectively. Overall, we found significant relationships between rates of respiratory symptoms and sleep complaints (trend chi 2 = 73.9, p < 0.001 for insomnia; trend chi 2 = 37.9, p < 0.001 for daytime sleepiness). In separate analyses, obesity, snoring, and a diagnosis of lung disease also influenced the rate of sleep complaints but, when we employed logistic regression, we found that obesity, respiratory symptoms, gender, and age were the only variables related to the risk of insomnia or daytime sleepiness.