Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1-3 Infections

Hepatitis C virus infection is causing chronic liver disease, cirrhosis, and hepatocellular carcinoma. By combining direct-acting antivirals (DAAs), high sustained virologic response rates (SVRs) can be achieved. Resistance-associated substitutions (RASs) are commonly observed after DAA failure, and especially nonstructural protein 5A (NS5A) RASs may impact retreatment options.^1-3 Data on retreatment of DAA failure patients using first-generation DAAs are limited.^4-7 Recently, a second-generation protease- and NS5A-inhibitor plus sofosbuvir (voxilaprevir/velpatasvir/sofosbuvir [VOX/VEL/SOF]) was approved for retreatment after DAA failure.⁸ However, this and other second-generation regimens are not available in many resource-limited countries or are not reimbursed by regular insurance, and recommendations regarding the selection of retreatment regimens using first-generation DAAs are very important. This study aimed to analyze patients who were re-treated with first-generation DAAs after failure of a DAA combination therapy.

Multichannel Cell Detection in Microcompartments by Means of True Parallel Measurements using the Solartron S-1260

Designing proper frontend electronics is critical in the development of highly sophisticated electrode systems. Multielectrode arrays for measuring electrical signals or impedance require multichannel readout systems. Even more challenging is the differential or ratiometric configuration with simultaneous assessment of measurement and reference channels. In this work, an eight-channel frontend was developed for contacting a 2×8 electrode array (8 measurement and 8 reference electrodes) with a large common electrode to the impedance gain-phase analyzer Solartron 1260 (S-1260). Using the three independent and truly parallel monitor channels of the S-1260, impedance of trapped cells and reference material was measured at the same time, thereby considerably increasing the performance of the device. The frontend electronics buffers the generator output and applies a potentiostatic signal to the common electrode of the chip. The applied voltage is monitored using the current monitor of the S-1260 via voltage/current conversion. The frontend monitors the current through the electrodes and converts it to a voltage fed into the voltage monitors of the S-1260. For assessment of the 8 electrode pairs featured by the chip, a relay-based multiplexer was implemented. Extensive characterization and calibration of the frontend were carried out in a frequency range between 100 Hz and 1 MHz. Investigating the influence of the multiplexer and the frontend electronics, direct measurement with and without frontend was compared. Although differences were evident, they have been negligible below one per cent. The significance of measurement using the complex S-1260-frontend-electrode was tested using Kohlrausch's law. The impedance of an electrolytic dilution series was measured and compared to the theoretical values. The coincidence of measured values and theoretical prediction serves as an indicator for electrode sensitivity to cell behavior. Monitoring of cell behavior on the microelectrode surface will be shown as an example.

Electrochemical Stability of Thin-Film Platinum as Suitable Material for Neural Stimulation Electrodes

Only thin-film technology can satisfy the requirements of high spatial selectivity at high-channel-count electrode array designs by simultaneously good conformability to the targeted tissue through mechanical flexibility enriching future applications of functional neural stimulation. However, caused by the high impact of the microstructure on the mechanical and electrochemical film properties, varying fabrication processes of the same thin-film makes the difference between acute and chronic long-term stable electrodes. The influence of standard clinical electrical pulsing on flexible polyimide-based thin-film platinum electrodes for neuroprostheses, either sputter deposited or evaporated, and different diameters was assessed and compared. The electrochemical and morphological analysis showed a higher corrosion susceptibility and electrochemical degradation for the sputter deposited platinum electrodes with even total failures of smaller diameters. In contrast, the evaporated thin-films provided itself as more stable and reliable metallization with also smaller electrodes keeping their film integrity intact over the experimental period, -appearing to be the preferable material for improving thin-film electrodes' longevity.

Clinical on-site monitoring of ß-lactam antibiotics for a personalized antibiotherapy

An appropriate antibiotherapy is crucial for the safety and recovery of patients. Depending on the clinical conditions of patients, the required dose to effectively eradicate an infection may vary. An inadequate dosing not only reduces the efficacy of the antibiotic, but also promotes the emergence of antimicrobial resistances. Therefore, a personalized therapy is of great interest for improved patients' outcome and will reduce in long-term the prevalence of multidrug-resistances. In this context, on-site monitoring of the antibiotic blood concentration is fundamental to facilitate an individual adjustment of the antibiotherapy. Herein, we present a bioinspired approach for the bedside monitoring of free accessible ß-lactam antibiotics, including penicillins (piperacillin) and cephalosporins (cefuroxime and cefazolin) in untreated plasma samples. The introduced system combines a disposable microfluidic chip with a naturally occurring penicillin-binding protein, resulting in a high-performance platform, capable of gauging very low antibiotic concentrations (less than 6 ng ml^-1) from only 1 µl of serum. The system's applicability to a personalized antibiotherapy was successfully demonstrated by monitoring the pharmacokinetics of patients, treated with ß-lactam antibiotics, undergoing surgery.

Platinum nanowires anchored on graphene-supported platinum nanoparticles as a highly active electrocatalyst towards glucose oxidation for fuel cell applications

The limited performance of platinum-based electrocatalysts for glucose electrooxidation is a major concern for glucose fuel cells, since glucose electrooxidation is characterized by slow reaction kinetics and low diffusion coefficient. Here, the presented graphene-supported platinum-based hierarchical nanostructures attain highly enhanced electrocatalytic activity towards glucose oxidation. Platinum nanoparticles electrodeposited on graphene support retain mechanical stability and act as junctions allowing a reliable, smooth and dense growth of platinum nanowires with extremely small diameters (>10 nm) on graphene. The electrode's surface roughness was increased by factors up to 4000 to the geometrical surface area enabling maximized exploitation of the electrocatalytic activity of platinum and efficient electron transfer between nanowires and the substrate. The unique three-dimensional geometry of these hierarchical nanostructures has a significant impact on their catalytic performance offering short diffusional paths for slow glucose species, thus, mass transport limitations are optimized leading to lower polarization losses. This was examined by galvanostatic measurements of the operation as anodes in glucose half-cells under conditions corresponding to implantable glucose fuel cells. The presented hierarchical nanostructures show remarkably enhanced catalytic performance for glucose electrooxidation, i.e. a negatively shifted open circuit potential of -580 mV vs. Ag/AgCl, hence, representing appropriate electrocatalysts for use as anodes in glucose fuel cells. In combination with a non-metal N-doped graphene cathode, a cell potential of 0.65 V was achieved at a galvanostatic load of 17.5 μA cm^-2 which noticeably surpasses the performance of state of the art catalysts for the aforementioned operation conditions.

Effect of the aromatic precursor flow rate on the morphology and properties of carbon nanostructures in plasma enhanced chemical vapor deposition

Understanding the effects of the synthesis parameters on the morphology and electrochemical properties of nanocarbon layers is a key step in the development of application-tailored nanostructures.

Self-assembled magnetic bead chains for sensitivity enhancement of microfluidic electrochemical biosensor platforms

In this paper, we present a novel approach to enhance the sensitivity of microfluidic biosensor platforms with self-assembled magnetic bead chains. An adjustable, more than 5-fold sensitivity enhancement is achieved by introducing a magnetic field gradient along a microfluidic channel by means of a soft-magnetic lattice with a 350 μm spacing. The alternating magnetic field induces the self-assembly of the magnetic beads in chains or clusters and thus improves the perfusion and active contact between the analyte and the beads. The soft-magnetic lattices can be applied independent of the channel geometry or chip material to any microfluidic biosensing platform. At the same time, the bead-based approach achieves chip reusability and shortened measurement times. The bead chain properties and the maximum flow velocity for bead retention were validated by optical microscopy in a glass capillary. The magnetic actuation system was successfully validated with a biotin-streptavidin model assay on a low-cost electrochemical microfluidic chip, fabricated by dry-film photoresist technology (DFR). Labelling with glucose oxidase (GOx) permits rapid electrochemical detection of enzymatically produced H2O2.

Immunohistochemical expression of Annexin A5 in preeclamptic placentas

OBJECTIVE

To study the expression of Annexin A5 (A5) in relation to preeclampsia using immunohistochemical Tissue Microarray (TMA) technique.

STUDY DESIGN

Case-control study of 66 singleton preeclamptic (PE) patients matched for gestational age (GA) at delivery with 63 normotensive controls with normally grown fetuses. Immunohistochemical expression of A5 and other population characteristics were compared between the two groups using Chi-square, One-way ANOVA, Spearman's Correlation, and Linear Regression.

RESULTS

The two groups were similar for maternal age and rate of corticosteroid administration, but differed for nulliparity, Body Mass Index (BMI), blood pressure, presence of placental histological lesions, and placental weight. Expression of A5 was similar in PE and controls (p = 0.10); however it was found to be lower in PE cases complicated by fetal growth restriction (FGR, n = 34) compared with matched controls (n = 55) (p = 0.04). An inverse correlation was found between A5 and GA in cases but not in controls (p = 0.04 vs p = 0.71). The association was even more significant in the subgroup of PE complicated by FGR (p = 0.02). A5 expression was not influenced by blood pressure, proteinuria, or placental weight.

CONCLUSIONS

Annexin A5 expression seems to be related only to FGR and not to PE or its clinical severity.

Percolation limit and stability conditions for the spin glass state in the spinel families based on the two matrices CuCr(2)S(4) and CuCr(2)Se(4) doped by Sb ions

The percolation limit of the appearance of the spin glass state in the compounds under study has been obtained experimentally. The conditions of stability of the spin glass state have been analyzed here on the basis of the de Almeida-Thouless theory for two spinels differing in the magnetic coupling constants. It turned out that for the higher value of the coupling constant the magnetic field influences the freezing temperature more strongly. Moreover, the greater the coupling constant the broader the range of the possible values of freezing temperatures, in other words the greater the temperature range of the appearance of the spin glass states. It was proved that for the stability of the spin glass state the existence of a small magnetic field is necessary. In our case the value of this field is equal to 3.46 × 10(-23)T(G). For the compounds under study the value of the magnetic coupling constant J cannot exceed 130 K for the spin glass state to appear.

Sensitivity enhancement for colorimetric glucose assays on whole blood by on-chip beam-guidance

In this paper, we present a novel concept for optical beam-guidance to significantly enhance the sensitivity of colorimetric assays by extending the optical path length through the detection cell which linearly impacts the resulting attenuation of a probe beam according to the law of Beer-Lambert. In our setup, the incident probe beam is deflected by 90( composite function) into the chip plane at monolithically integrated V-grooves to pass a flat detection cell at its full width (i.e., with a path length of 10 mm) instead of its usually much smaller height. Afterwards, the attenuated beam is redirected by another V-groove towards an external detector. The general beam-guidance concept is demonstrated by a glucose assay on human whole blood on a centrifugal microfluidic "lab-on-a-disk" platform made of COC. We achieve an excellent linearity with a correlation coefficient (R (2)) of 0.997 paired with a lower limit of detection (200 microM) and a good reproducibility with a coefficient of variation (CV) of 4.0% over nearly three orders of magnitude. With an accelerated sedimentation of cellular constituents by centrifugal forces, the sample of whole blood can be analyzed in a fully integrated fashion within 210 s. This time-to-result can even be improved by the numerical extrapolation of the saturation value. Additionally, the direct assay on whole blood also shows a negligible correlation with the hematocrit of the blood sample.

Antibody response to collagen after functional implantation of different polyester vascular prostheses in pigs

Besides inflammation, specific immune responses are seen also after implantation of biomaterials. The aim was to investigate the humoral response to bovine collagen type I following implantation of various polyester (Dacron) prostheses into pigs. In 24 randomized pigs, the infrarenal aorta was replaced with a segment of collagen-impregnated, woven polyester prosthesis of low, medium, or high porosity. IgG antibodies were detected by immunoassay using native and denatured collagen type I as a target for blood samples taken on day 1 (implantation), 10, 17, 24, 62, and 116. As generally observed, antibodies to native and denatured collagen are of low titer and were significantly correlated with enhanced binding to the denatured form (p < 0.001). The highest overall antibody prevalence to native and denatured collagen was obtained on day 116 with 68% and on day 62 with 59%, respectively. Prostheses with high porosity induced an early immune response on day 10; those with low and medium porosity induced the highest antibody levels later after 2 months. Collagen antibodies neither correlated with serum IgG contents nor with antibodies to the prosthesis polyester matrix. Thus, humoral immune response against implant components may provide a further parameter in describing biocompatibility but also a potential marker that may facilitate monitoring of individual perigraft reaction.

The influence of antimicrobial treatments on the cytocompatibility of polyurethane biosensor membranes

The cytocompatibility of polyurethane membranes was tested following ultraviolet or gamma irradiation as well as treatment with hydrogen peroxide or glutaraldehyde containing solutions. Despite the fact that all of the methods had been recommended for antimicrobial treatment of glucose biosensors, the treatments investigated significantly influenced cytocompatibility characteristics. Cytotoxicity of membrane eluates was not observed following irradiation treatments. This was also the case when the membranes were repeatedly washed following chemical treatment. Cell growth upon the membranes was stimulated to a different extent after gamma and UV irradiation as well as following hydrogen peroxide treatments. Residues of an urea-based hydrogen peroxide inclusion compound caused a restriction in cell growth upon the membranes as was similarly observed with 2 and 4% glutaraldehyde solutions acting over 2 and 4 h, respectively. It is concluded that cytocompatibility in vitro reflecting the host response against a biomaterial in vivo does not only depend upon the material itself but also upon antimicrobial treatments which could have consequences for its bioperformance characteristics.

Immunogenicity of polymeric implants: long-term antibody response against polyester (Dacron) following the implantation of vascular prostheses into LEW.1A rats

Implanted biomaterials trigger acute and chronic inflammatory responses directly correlated to the central role of phagocytic cells at the host-implant interface. This study was designed to evaluate specific humoral immune responses following repeated intraperitoneal implantations of collagen-impregnated polyester (Dacron) prosthetic segments into LEWIS rats. Serum antibody detection was performed by enzyme immunoassay with the prosthetic segments as a target. Cutoff values for antibody positivity were greater than or equal to the 99th percentile for control rats. Polymer immunoglobiulin G (IgG) antibodies were significantly increased (p < 0.05) by repeated implantation and were subsequently followed until experimental day 293. Antibody formation was significantly enhanced through the application of complete Freund's adjuvant in combination with the first implantation. All rats within this group were antibody-positive on day 53, but only 6 of 10 animals that received the prosthesis without the adjuvant were. After preincubation of sera with bovine collagen type I (solid phase adsorbed or in solution), polymer antibody binding was discovered not to be diminished, indicating that the IgG antibodies detected were not directed against the prosthesis impregnation. Furthermore, a significant correlation was obtained between polymer antibody binding to collagen-impregnated and nonimpregnated prostheses (r(s) = 0.797, p < 0.001). There was no substantiated correlation between antibody binding to polyester and to an irrelevant polymer (Tecoflex EG 80). We conclude that specific polymer antibodies may indeed provide an additional parameter for biocompatibility testing as well as a possible serological marker of an inflammatory response to implants.

A versatile biosensor device for continuous biomedical monitoring

Although biosensors are by means suitable for continuous biomedical monitoring, due to fouling and blood clotting, in vivo performance is far from optimal. For this reason, ultrafiltration, microdialysis or open tubular flow is frequently used as interface. To secure quantitative recoveries of the analyte of interest, sampling at submicrolitre level will be necessary which in turn necessitates the development of small and versatile biosensor devices. Here, a miniaturised biosensor device, which directly can be connected to various interfaces will be presented. The biosensor device consists of a pulsefree pump and a biosensor with an internal volume of 10-20 nl. In this article, the production as well as the construction of the flow-through cell of the biosensor will be discussed. The advantages and disadvantages of several production processes will be demonstrated and a detailed protocol for the production of such a nanoliter flow-through cell will be presented. With respect to the bio-selector, several permselective membranes have been tested on their performance characteristics. Results obtained with these biosensors will be presented and discussed. Finally, a protocol based upon in situ electropolymerisation for the immobilisation of the biological component was defined and several biosensors based upon this principle have been produced and tested for the monitoring of glucose respectively lactate. To demonstrate, data obtained during a variety of in vivo studies at different clinical relevant applications will be presented.

Test of a potential link between analytic and nonanalytic category learning and automatic, effortful processing

The link between automatic and effortful processing and nonanalytic and analytic category learning was evaluated in a sample of 29 college undergraduates using declarative memory, semantic category search, and pseudoword categorization tasks. Automatic and effortful processing measures were hypothesized to be associated with nonanalytic and analytic categorization, respectively. Results suggested that contrary to prediction strong criterion-attribute (analytic) responding on the pseudoword categorization task was associated with strong automatic, implicit memory encoding of frequency-of-occurrence information. Data are discussed in terms of the possibility that criterion-attribute category knowledge, once established, may be expressed with few attentional resources. The data indicate that attention resource requirements, even for the same stimuli and task, vary depending on the category rule system utilized. Also, the automaticity emerging from familiarity with analytic category exemplars is very different from the automaticity arising from extensive practice on a semantic category search task. The data do not support any simple mapping of analytic and nonanalytic forms of category learning onto the automatic and effortful processing dichotomy and challenge simple models of brain asymmetries for such procedures.

Fetomaternal adrenomedullin levels in diabetic pregnancy

We investigated whether maternal and fetoplacental adrenomedullin, a newly discovered hypotensive peptide involved in the insulin regulatory system, is modified in diabetic pregnancy. We studied its correlation with pregnancy complications associated with this disease. Thirty-six pregnant women with diabetes (13 with type I and 23 with gestational diabetes mellitus) and in 40 uncomplicated pregnancies were included. 10 out of 36 diabetic pregnancies were complicated by gestational hypertension. In each woman, adrenomedullin concentration in maternal and fetal plasma and in amniotic fluid was assessed by specific radioimmunoassay. We found that overall mean amniotic fluid adrenomedullin concentration was higher (p < 0.05) in diabetic (14.7 +/- 1.6 fmol/ml) than in uncomplicated pregnancies (10.8 +/- 0.9 fmol/ml), whereas no differences were present in maternal and fetal plasma adrenomedullin levels between diabetic and uncomplicated pregnant women. High levels of amniotic fluid adrenomedullin were found in both type I and gestational diabetes mellitus pregnancies (13.7 +/- 1.4 and 15.6 +/- 2.2 fmol/ml, respectively). Diabetic pregnancies complicated by gestational hypertension showed lower (p < 0.05) amniotic fluid adrenomedullin concentrations than normotensive diabetic patients. These findings suggest that placental adrenomedullin production is upregulated in diabetic pregnancy, and it may be important to prevent excessive vasoconstriction of placental vessels.

Identification of an estrogen-inducible phosphatase (PP5) that converts MCF-7 human breast carcinoma cells into an estrogen-independent phenotype when expressed constitutively

The proliferation of many estrogen receptor (ER)-positive breast cancer cells depends on estradiol, and tumors arising from these cells are often responsive initially to treatment with selective ER modulators, which produce an antiestrogen effect. However, tumors that are refractory to the antiestrogenic effects of selective ER modulators often reemerge, and the prognosis for these patients is poor because of the lack of additional effective therapy. Accordingly, deciphering the cellular events associated with estrogen-dependent growth and the subsequent outgrowth of tumors with an estrogen-independent phenotype is of considerable interest. Here we show that the expression of PP5, an evolutionarily conserved Ser/Thr phosphatase that functions as an inhibitor of glucocorticoid- and p53-induced signaling cascades leading to growth suppression, is responsive to 17beta-estradiol (E(2)) in ER-positive human breast carcinoma cells (MCF-7). Northern analysis revealed that E(2)-induced PP5 expression is blocked by treatment with tamoxifen, and a consensus ER recognition element was identified in the PP5 promoter. The PP5-ER recognition element associates with human ERs and confers E(2)-induced transcriptional activation to reporter plasmids. The specific inhibition of PP5 expression ablates E(2)-mediated proliferation in MCF-7 cells without having an apparent effect on E(2)-induced expression of c-myc or cyclin D1. Thus, although critical for cell growth, PP5 likely acts either downstream or independently of c-Myc and Cyclin D1. To further characterize the role of PP5 in E(2)-regulated growth control, we constructed stable MCF-7 cell lines in which the expression of PP5 was placed under the control of tetracycline-regulated transactivator and operator plasmids. Studies with these cells revealed that the constitutive overexpression of PP5 affords E(2)-dependent MCF-7 cells with the ability to proliferate in E(2)-depleted media. Together, these studies indicate that E(2)-induced PP5 expression functions to enhance E(2)-initiated signaling cascades leading to cell division and that aberrant PP5 expression may contribute to the development of MCF-7 cells with an estrogen-independent phenotype.

Antigenicity of Polyester (Dacron) Vascular Prostheses in an Animal Model

Objectives to investigate the specific humoral immune response to three different polyester (Dacron) prostheses in pigs. Design, materials and methods twenty-four growing pigs were randomly divided into three groups. The infrarenal aorta was replaced by a segment of collagen-impregnated woven polyester prosthesis (low, medium and high porosity). Serum antibodies were detected by modified enzyme immunoassay using non-impregnated prosthesis as the target for the blood samples taken on experimental days 1, 10, 17, 24, 62 and 116 of the 22 pigs followed over the whole observation period. Results significantly enhanced (p <0.05) mean IgG antibody binding against polyester was detected on experimental days 10, 17, 24 and 62 with antibody prevalences of 41%, 41%, 32% and 37%, respectively. Antibody positive pigs were divided into early responders (n =9) and late responders ( n =5) with antibody detection on day 10 and/or 17 vs day 62 and/or 116. No significant differences between the three different prostheses were found. The formation of specific IgG antibodies against polyester in the animals investigated demonstrates a broad individual variability. Conclusions polyester is an antigenic polymer. Specific antibodies, reflecting the inflammatory response, might be not only a parameter for testing biomaterials but also for determining individual bio(in)compatibility for long-term biomaterial function.

Lipopeptide adjuvants: generation of lactate dehydrogenase isoenzyme-specific antibodies for immunochemical diagnosis

Lactate dehydrogenase catalyzes the final step in glycolysis, the interconversion of pyruvate and lactate. The tetrameric enzyme is composed of one or two subunits (H and/or M) resulting in five isoenzyme forms: LDH-H4, -H3M1, -H2M2, -H1M3, and -M4. The relative distribution of the LDH isoenzymes is tissue dependent and a significant marker for the diagnosis of hepatoma of the liver, myocardial infarction, muscular dystrophy, and a wide variety of other acute and chronic diseases to be detected by alterations of the LDH isoenzyme pattern in serum. Immunochemical approaches to the routine determination of LDH depend on isoenzyme specific antibodies. Since the H- and M-subunits for human LDH are highly homologous, LDH isoenzyme specific antibodies for immunochemical monitoring are hard to generate. Here we present data on the generation and characterization of LDH isoenzyme-specific mono- and polyclonal antibodies in different species in the presence of lipopeptide adjuvants. Western-Blot and ELISA analysis showed that antisera and monoclonal antibodies recognize their homologous antigens with high specificity and are therefore suitable for immunochemical monitoring of the LDH isoenzymes H4 and M4. In addition, they can be used for the determination of LDH isoenzyme specific activity which is an essential prerequisite for online amperometric immunosensor monitoring.

New placental factors: Between implantation and inflammatory reaction

The trophoblast invasion is a dynamic changes in cell-cell and cell matrix interaction and it create in the endometrio a reaction similar to the inflammatory reaction. In the recent past most of the investigator in this field had focus on the mediator of this process especially on cytokine and on vasoactive agent. We have studied the inducible isoform of nitric oxide synthase (iNOS), adrenomedullin (AM), fatty acid synthase (FAS), and S-100 protein. Several evidences had lead our choice: the two first factors are essentially local mediator of vasospasm which works in synergy during the inflammatory reaction, but the AM I addition stimulates the DNA synthesis and cell proliferation of Swiss 3T3 fibroblasts, induces the cell cycle progression from G0 to G1 phase and the malignant cell lines express AM mRNA and mRNA for its receptor and the pattern of distribution of ir-AM and its mRNA during murine development is similar to that of other growth factors (TGFb isoforms, PDGF, FGF, IGF 1 and 2); Fatty acid synthase (FAS) is a major biosynthetic enzyme of intracellular fatty acid synthesis, its expression and activity is enhanced in proliferative tissues, such as malignant cells; S-100 is an acid calcium binding protein present in central nervous system where it is in mainly concentrated in the glial cells, astrocytes, Schwann cells, and neurons. It regulates several functions such as cell-cell communication, cell growth, cell structure, energy metabolism, contraction, and intracellular signal transduction. Recently the appearance in blood of S100 in preterm infants has been used as a marker of brain damage in perinatal period. The iNOS, AM, S100 and FAS are localized in both decidual and trophoblastic cells in early pregnancy, but we found that changes in iNOS, S100, AM, and FAS are different in spontaneous abortion (SA) versus voluntary pregnancy termination (VPT). Considering the VPT as non pathologic pregnancy, this difference may reflect functional modifications of placental tissues. Our result shown that AM and NO are increased in VPT vs SA showing that when the process of implantation is on course we found an higher expression that we have during the inflammatory reaction. [Table: see text]

[Iodine supplementation during pregnancy and its influence on the newborn]

The aim of this study was comparison of urinary iodine excretion among parturients and their newborns with iodine supplementation (study group) and parturiens and their newborns without this supplementation (control group). Concentration of iodine jons in urine < 10 micrograms/100 ml was 7.7% in study group and 35.7% in control group. Mothers who received iodine had newborns with low concentration of iodine jons in 15.4% and 57.2% in control group. There is inadequate iodine supply among silesian pregnant women and in their neonates so additional maternal iodine supplementation is necessary.

Ser/Thr protein phosphatase type 5 (PP5) is a negative regulator of glucocorticoid receptor-mediated growth arrest

Ligand-induced glucocorticoid receptor (GR) activation has recently been linked to the inhibition of cell proliferation via the transcriptional induction of p21(WAF1/Cip1), which functions as a universal inhibitor of cyclin-dependent protein kinases. Herein, we identify a Ser/Thr protein phosphatase (PP5) that promotes cellular proliferation by inhibiting both glucocorticoid and p53-mediated signaling pathways leading to p21(WAF1/Cip1)-mediated growth arrest. The suppression of PP5 expression (1) markedly increases the association of GR with its cognate DNA-binding sequence, (2) induces GR transcriptional activity without the addition of hormone, and (3) increases dexamethasone-mediated induction of GR reporter activity to a level that is approximately 10 times greater than the maximal response obtainable in the presence of PP5. PP5 has no apparent effect on the binding of hormone to the GR, and dexamethasone-mediated growth arrest correlates with an increase in p53 phosphorylation. Comparative studies in p53-wild-type, p53-defective, and p53-deficient cell lines indicate that either (1) p53 participates in GR-mediated induction of p21(WAF1/Cip1), with the hyperphosphorylation of basal p53 induced by glucocorticoids sufficient for the propagation of an antiproliferative response when PP5 expression is inhibited, or (2) PP5 acts where p53-mediated and GR-induced signaling networks converge to regulate the transcriptional induction of p21(WAF1/Cip1). Thus, aberrant PP5 expression may have an additive effect on the development of human cancers by promoting cell proliferation via the inhibition of a GR-induced antiproliferative signaling cascade, and facilitating neoplastic transformation via the inhibition of a growth-arresting p53-mediated response that guards against genomic instability.

[The occurrence of malformations in newborns from highly polluted environment: own materials from years 1993-1998]

OBJECTIVES

Epidemiological rates and the structure of malformations in live born infants from the II Chair and Clinic of Obstetrics and Gynecology in Zabrze in the year 1993-1998 are shown in this paper.

MATERIAL AND METHODS

5898 newborns with weight over 500 g were examined. 341 histories of development of newborns with malformations were analysed. Statistical calculations were performed using Chi square test.

RESULTS

It was stated, that the percentage of malformations was 5.8% in examined period with 1.6% of severe malformations in it. Malformations of genitourinary, osteoarticular and circulatory systems were of the most frequent occurrence. Frequency of intrauterine hypotrophy in newborns with malformations was statistically significantly higher than in the group of all examined infants.

CONCLUSIONS

Hypotrophy is to a higher degree than prematurity connected with the hazard of presence of congenital malformation. Considering constant increase of the number of malformations which was shown in this paper, there is urgent necessity of introducing of the comprehensive registry of malformations in Upper Silesia.

Novel system for real-time ex vivo lactate monitoring in human whole blood

The objective of the study was to evaluate the performance of an amperometric enzyme based lactate sensor and to investigate the possibility of replacing a double lumen catheter based blood withdrawal system with a heparin coated single lumen system. The inner lumen of a double lumen catheter which was placed in a peripheral vein was perfused with heparin solution. The outer lumen was used to collect heparinized blood samples at a defined flow rate. The single lumen system was attached to a heparinized catheter which was also placed in a peripheral vein. The undiluted blood samples were collected at a specified flow rate. A sensor flow chamber incorporating an amperometric thin-film lactate microbiosensor was placed in the sampling line for real-time lactate monitoring. Plasma lactate concentrations were measured during frequently performed hyperlactatemia bicycle ergometer experiments in six healthy volunteers (age 25.8 +/- 2.8 years, BMI 22.7 +/- 1 kg/m2). Additionally, plasma lactate was measured in real-time using the lactate sensors. The first three experiments were performed with a double lumen based catheter system whereas the following three experiments were performed with a heparin coated catheter system. The correlation coefficients of sensor readings and laboratory analyzer results in all six experiments were between 0.93 and 0.99, respectively (P < 0.001). The miniaturized lactate sensors showed a linear range up to 25 mmol/l lactate concentration and 95% response times < 30 s in undiluted serum. During the experiments maximum lactate concentrations of 14 mmol/l were achieved. Improvements of system performance using heparin coated catheter systems could be shown. The overall SD of the sensor readings compared to laboratory results using three double lumen catheter based systems was 0.91 mmol/l whereas the SD using three heparin coated systems was 0.65 mmol/l. In summary, real-time monitoring of lactate in human whole blood is feasible with such a device and can be improved by using heparin coated catheter systems.

[Urinary tract infections in pregnancy: perinatal problem]

The authors presented the frequency of urinary tract infection (u.t.i) in pregnancy in own practice. Additional complications in pregnancy with asymptomatic bacteriuria and acute pyelonephritis were described. Postnatal period of neonates born from mothers with u.t.i. in pregnancy were analyzed. The authors defined the frequency of intrauterine hypotrophy and infectious complications in above newborns.

Continuous measurement of subcutaneous lactate concentration during exercise by combining open-flow microperfusion and thin-film lactate sensors

The present study was carried out to investigate in vivo in healthy humans the method of open-flow microperfusion for monitoring of the subcutaneous (s.c.) lactate concentration during rest and cycle ergometer exercise. Using open-flow microperfusion, a perforated double lumen catheter with an inflow and an outflow connection is inserted into the s.c. adipose tissue and perfused with a sterile, isotonic, ionfree fluid. Due to the low flow rate, the fluid partially equilibrates with the surrounding tissue. The equilibrated perfusate passes a sensor flow chamber where the substance of interest and the rate of recovery (i.e. the ratio of sampled concentration to interstitial concentration) are continuously monitored. Within this study, the method was evaluated in four healthy volunteers during cycle ergometer exercise. The relative increase of the lactate concentration was approximately a third in the s.c. tissue compared to the capillary blood and the peak time was delayed on average by 10 min. The correlation coefficient between blood and s.c. tissue lactate concentration ranged from r = 0.41 to r = 0.90 (n = 29) in the individual experiments. The combination of open-flow microperfusion and lactate and conductivity sensors enables on-line monitoring of the s.c. lactate concentration without in vivo calibration during steady-state and cycle ergometer exercise.

Novel instrumentation for real-time monitoring using miniaturized flow systems with integrated biosensors

A prototype miniaturized Total Chemical Analysis System (muTAS) has been developed and applied to on-line monitoring of glucose and lactate in the core blood of anaesthetized dogs. The system consists of a highly efficient microdialysis sampling interface sited in a small-scale extracorporeal shunt circuit ('MiniShunt'), a silicon machined microflow manifold and integrated biosensor array for glucose and lactate detection with associated computer software for analytical process control. During in-vivo testing the device allowed real-time on-screen monitoring of glucose and lactate with system response times of less than 5 min, made possible by the small dead volume of the microflow system. On-line glucose and lactate measurements were made in the basal state as well as during intravenous infusion of glucose or lactate. The prototype muTAS is currently suitable for trend monitoring but refinements are necessary before application of the system for determination of individual lactate values.