Simultaneous Immobilization of Heavy Metals in MKPC-Based Mortar-Experimental Assessment

Heavy metal contamination, associated with the increase in industrial production and the development of the population in general, poses a significant risk in terms of the contamination of soil, water, and, consequently, industrial plants and human health. The presence of ecotoxic heavy metals (HMs) thus significantly limits the sustainable development of society and contributes to the deterioration of the quality of the environment as a whole. For this reason, the stabilization and immobilization of heavy metals is a very topical issue. This paper deals with the possibility of the simultaneous immobilization of heavy metals (Ba2+, Pb2+, and Zn2+) in mortar based on magnesium potassium phosphate cement (MKPC). The structural, mechanical, and hygric parameters of mortars artificially contaminated with heavy metals in the form of salt solutions were investigated together with the formed hydration products. In the leachates of the prepared samples, the content of HMs was measured and the immobilization ratio of each HM was determined. The immobilization rate of all the investigated HMs was >98.7%, which gave information about the effectiveness of the MKPC-based matrix for HM stabilization. Furthermore, the content of HMs in the leachates was below the prescribed limits for non-hazardous waste that can be safely treated without any environmental risks. Although the presence of heavy metals led to a reduction in the strength of the prepared mortar (46.5% and 57.3% in compressive and flexural strength, respectively), its mechanical resistance remained high enough for many construction applications. Moreover, the low values of the parameters characterizing the water transport (water absorption coefficient Aw = 4.26 × 10-3 kg·m-2·s-1/2 and sorptivity S = 4.0 × 10-6 m·s-1/2) clearly demonstrate the limited possibility of the leaching of heavy metals from the MKPC matrix structure.

MOC Composites for Construction: Improvement in Water Resistance by Addition of Nanodopants and Polyphenol

The topic of modification of magnesium oxychloride cement (MOC) using specific functional additives is very much pronounced in the research of alternative building materials. This study deals with the co-doping of MOC by 1D and 2D carbon nanomaterials in order to improve its mechanical properties while using tannic acid (TA) as a surfactant. Furthermore, the effect of TA on MOC also improves its water resistance. As a filler, three size fractions of standard quartz sand are used. The proposed types of MOC-based composites show promising results considering their mechanical, macro- and microstructural, chemical, and hygric properties. The use of 1D and 2D nanoadditives and their mixture enables the improvement in the flexural strength and particularly the softening coefficient, which is the durability parameter characterizing the resistance of the prepared materials to water. After immersion in water for 24 h, the compressive strength of all tested specimens of modified composites was higher than that of the reference composite. Quantitatively, the developed co-doped composites show mechanical parameters comparable to or even better than those of commonly used Portland cement-based materials while maintaining high environmental efficiency. This indicates their potential use as an environmentally friendly alternative to Portland cement-based products.

Diatomaceous Earth-Lightweight Pozzolanic Admixtures for Repair Mortars-Complex Chemical and Physical Assessment

The presented research is focused on the complex assessment of three different types of diatomaceous earth and evaluation of their ability for application as pozzolana active admixtures applicable in the concrete industry and the production of repair mortars applicable for historical masonry. The comprehensive experimental campaign comprised chemical, mineralogical, microstructural, and physical testing of raw materials, followed by the analyses and characterization of pozzolanic activity, rheology and heat evolution of fresh blended pastes, and testing of macrostructural and mechanical parameters of the hardened 28-days and 90-days samples. The obtained results gave evidence of the different behavior of researched diatomaceous earth when mixed with water and Portland cement. The differences in heat evolution, initial and final setting time, porosity, density, and mechanical parameters were identified based on chemical and phase composition, particle size, specific surface, and morphology of diatomaceous particles. Nevertheless, the researched mineral admixtures yielded a high strength activity index (92.9% to 113.6%), evinced their pozzolanic activity. Three fundamental factors were identified that affect diatomaceous earth's contribution to the mechanical strength of cement blends. These are the filler effect, the pertinent acceleration of OPC hydration, and the pozzolanic reaction of diatomite with Portland cement hydrates. The optimum replacement level of ordinary Portland cement by diatomaceous earth to give maximum long-term strength enhancement is about 10 wt.%., but it might be further enhanced based on the properties of pozzolan.

Co-Doped Magnesium Oxychloride Composites with Unique Flexural Strength for Construction Use

In this study, the combined effect of graphene oxide (GO) and oxidized multi-walled carbon nanotubes (OMWCNTs) on material properties of the magnesium oxychloride (MOC) phase 5 was analyzed. The selected carbon-based nanoadditives were used in small content in order to obtain higher values of mechanical parameters and higher water resistance while maintaining acceptable price of the final composites. Two sets of samples containing either 0.1 wt. % or 0.2 wt. % of both nanoadditives were prepared, in addition to a set of reference samples without additives. Samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, and energy dispersive spectroscopy, which were used to obtain the basic information on the phase and chemical composition, as well as the microstructure and morphology. Basic macro- and micro-structural parameters were studied in order to determine the effect of the nanoadditives on the open porosity, bulk and specific density. In addition, the mechanical, hygric and thermal parameters of the prepared nano-doped composites were acquired and compared to the reference sample. An enhancement of all the mentioned types of parameters was observed. This can be assigned to the drop in porosity when GO and OMWCNTs were used. This research shows a pathway of increasing the water resistance of MOC-based composites, which is an important step in the development of the new generation of construction materials.

Zeolite Lightweight Repair Renders: Effect of Binder Type on Properties and Salt Crystallization Resistance

Rendering mortars with lightweight zeolite aggregates were designed and tested. The effect of the type of binder used was also researched. For the hardened mortars, macrostructural parameters, mechanical characteristics, hygric and thermal properties were assessed. Specific attention was paid to the analysis of the salt crystallization resistance of the developed rendering mortars. Quartz sand was fully replaced in the composition of mortars with zeolite gave materials with low density, high porosity, sufficient mechanical strength, high water vapor permeability and high water absorption coefficient, which are technical parameters required for repair rendering mortars as prescribed in the WTA directive 2-9-04/D and EN 998-1. Moreover, the zeolite enhanced mortars exhibit good thermal insulation performance and high sorption capacity. The examined rendering mortars were found to be well durable against salt crystallization, which supports their applicability in salt-laden masonry. Based on the compatibility of the repair materials with those originally used, the lime and natural hydraulic lime zeolite mortars can be used as rendering mortars for the repair of historical and heritage buildings. The cement-lime zeolite render is applicable for repair purposes only in the case of the renewal of masonry in which Portland cement-based materials were originally used.

Lightweight Vapor-Permeable Plasters for Building Repair Detailed Experimental Analysis of the Functional Properties

Three types of lightweight plasters for building repair were prepared and tested. The composition of plasters was designed in respect to their compatibility with materials used in the past in historical masonry. For the hardened plasters, detailed testing of microstructural and macrostructural parameters was realized together with the broad experimental campaign focused on the assessment of mechanical, hygric, and thermal properties. As the researched plasters should find use in salt-laden masonry, specific attention was paid to the testing of their durability against salt crystallization. The mechanical resistance, porosity, water vapor transmission properties, and water transport parameters of all the researched plasters safely met criteria of WTA directive 2-9-04/D and standard EN 998-1 imposed on repair mortars. Moreover, the tested materials were ranked as lightweight plasters and due to their low thermal conductivity they can be used for the improvement of thermal performance of repaired masonry. The salt crystallization test caused little or no damage of the plasters, which was due to their high porosity that provided free space for salt crystallization. The developed plasters can be recommended for application in repair of damp and salt masonry and due to their compatible composition also in historical, culture heritage buildings. The added value of plasters is also their good thermal insulation performance.

MOC Doped with Graphene Nanoplatelets: The Influence of the Mixture Preparation Technology on Its Properties

The ongoing tendency to create environmentally friendly building materials is nowadays connected with the use of reactive magnesia-based composites. The aim of the presented research was to develop an ecologically sustainable composite material based on MOC (magnesium oxychloride cement) with excellent mechanical, chemical, and physical properties. The effect of the preparation procedure of MOC pastes doped with graphene nanoplatelets on their fresh and hardened properties was researched. One-step and two-step homogenization techniques were proposed as prospective tools for the production of MOC-based composites of advanced parameters. The conducted experiments and analyses covered X-ray fluorescence, scanning electron microscopy, energy-dispersive spectroscopy, high-resolution transmission electron microscopy, sorption analysis, X-ray diffraction, and optical microscopy. The viscosity of the fresh mixtures was monitored using a rotational viscometer. For the hardened composites, macro- and micro-structural parameters were measured together with the mechanical parameters. These tests were performed after 7 days and 14 days. The use of a carbon-based nanoadditive led to a significant drop in porosity, thus densifying the MOC matrix. Accordingly, the mechanical resistance was greatly improved by graphene nanoplatelets. The two-step homogenization procedure positively affected all researched functional parameters of the developed composites (e.g., the compressive strength increase of approximately 54% after 7 days, and 37% after 14 days, respectively) and can be recommended for the preparation of advanced functional materials reinforced with graphene.

Magnesium Oxychloride Cement Composites with MWCNT for the Construction Applications

In this contribution, composite materials based on magnesium oxychloride cement (MOC) with multi-walled carbon nanotubes (MWCNTs) used as an additive were prepared and characterized. The prepared composites contained 0.5 and 1 wt.% of MWCNTs, and these samples were compared with the pure MOC Phase 5 reference. The composites were characterized using a broad spectrum of analytical methods to determine the phase and chemical composition, morphology, and thermal behavior. In addition, the basic structural parameters, pore size distribution, mechanical strength, stiffness, and hygrothermal performance of the composites, aged 14 days, were also the subject of investigation. The MWCNT-doped composites showed high compactness, increased mechanical resistance, stiffness, and water resistance, which is crucial for their application in the construction industry and their future use in the design and development of alternative building products.

The Impact of Graphene and Diatomite Admixtures on the Performance and Properties of High-Performance Magnesium Oxychloride Cement Composites

A high-performance magnesium oxychloride cement (MOC) composite composed of silica sand, diatomite powder, and doped with graphene nanoplatelets was prepared and characterized. Diatomite was used as a 10 vol.% replacement for silica sand. The dosage of graphene was 0.5 wt.% of the sum of the MgO and MgCl₂·6H₂O masses. The broad product characterization included high-resolution transmission electron microscopy, X-ray diffraction, X-ray fluorescence, scanning electron microscopy and energy dispersive spectroscopy analyses. The macrostructural parameters, pore size distribution, mechanical resistance, stiffness, hygric and thermal parameters of the composites matured for 28-days were also the subject of investigation. The combination of diatomite and graphene nanoplatelets greatly reduced the porosity and average pore size in comparison with the reference material composed of MOC and silica sand. In the developed composites, well stable and mechanically resistant phase 5 was the only precipitated compound. Therefore, the developed composite shows high compactness, strength, and low water imbibition which ensure high application potential of this novel type of material in the construction industry.

Magnesium Oxychloride Cement Composites Lightened with Granulated Scrap Tires and Expanded Glass

In this paper, light burned magnesia dispersed in the magnesium chloride solution was used for the manufacturing of magnesium oxychloride cement-based composites which were lightened by granulated scrap tires and expanded glass. In a reference composite, silica sand was used only as filler. In the lightened materials, granulated shredded tires were used as 100%, 90%, 80%, and 70% silica sand volumetric replacement. The rest was compensated by the addition of expanded glass granules. The filling materials were characterized by particle size distribution, specific density, dry powder density, and thermal properties that were analyzed for both loose and compacted aggregates. For the hardened air-cured samples, macrostructural parameters, mechanical properties, and hygric and thermal parameters were investigated. Specific attention was paid to the penetration of water and water-damage, which were considered as crucial durability parameters. Therefore, the compressive strength of samples retained after immersion for 24 h in water was tested and the water resistance coefficient was assessed. The use of processed waste rubber and expanded glass granulate enabled the development of lightweight materials with sufficient mechanical strength and stiffness, low permeability for water, enhanced thermal insulation properties, and durability in contact with water. These properties make the produced composites an interesting alternative to Portland cement-based materials. Moreover, the use of low-carbon binder and waste tires can be considered as an eco-efficient added value of these products which could improve the environmental impact of the construction industry.

Magnesium Oxychloride Cement Composites with Silica Filler and Coal Fly Ash Admixture

Worldwide, Portland cement-based materials are the most commonly used construction materials. As the Portland cement industry negatively affects the environment due to the excessive emission of carbon dioxide and depletion of natural resources, new alternative materials are being searched. Therefore, the goal of the paper was to design and develop eco-friendly, low-cost, and sustainable magnesium oxychloride cement (MOC)-based building material with a low carbon footprint, which is characterized by reduced porosity, high mechanical resistance, and durability in terms of water damage. To make new material eco-efficient and functional, silica sand which was used in the composition of the control composite mixture was partially replaced with coal fly ash (FA), a byproduct of coal combustion. The chemical and mineralogical composition, morphology, and particle morphology of FA were characterized. For silica sand, FA, and MgO, specific density, loose bulk density, and particle size distribution were measured. Additionally, Blaine specific surface was for FA and MgO powder assessed. The workability of fresh mixtures was characterized by spread diameter. For the hardened MOC composites, basic structural, mechanical, hygric, and thermal properties were measured. Moreover, the phase composition of precipitated MOC phases and their thermal stability were investigated for MOC-FA pastes. The use of FA led to the great decrease in porosity and pore size compared to the control material with silica sand as only filler which was in agreement with the workability of fresh composite mixtures. The compressive strength increased with the replacement of silica sand with FA. On the contrary, the flexural strength slightly decreased with silica sand substitution ratio. It clearly proved the assumption of the filler function of FA, whereas its assumed reactivity with MOC cement components was not proven. The water transport and storage were significantly reduced by the use of FA in composites, which greatly improved their resistance against moisture damage. The heat transport and storage parameters were only slightly affected by FA incorporation in composite mixtures.

Complex Characterization and Behavior of Waste Fired Brick Powder-Portland Cement System

Two waste fired brick powders coming from brick factories located in Argentine and Czech Republic were examined as alternative mineral admixtures for the production of blended cements. In pastes composition, local Portland cements (Argentine and Czech) were substituted with 8–40%, by mass, with powdered ceramic waste. For the ceramic waste-Portland cement system, workability, the heat released, pozzolanity, specific density, compressive strength, hydrated phases, porosity, and pore size distribution were tested. The relevance of the dilution effect, filler effect, and pozzolanic activity was analyzed to describe the general behavior of the pozzolan/cement system. The properties and performance of cement blends made with finely ground brick powder depended on the composition of ceramic waste and its reactivity, the plain cement used, and the replacement level. Results showed that the initial mini-slump was not affected by a low ceramic waste replacement (8% and 16%), and then it was decreased with an increase in the ceramic waste content. Brick powder behaved as a filler at early ages, but when the hydration proceeded, its pozzolanic activity consumed partially the calcium hydroxide and promoted the formation of hydrated calcium aluminates depending on the age and present carbonates. Finally, blended cements with fired brick powder had low compressive strength at early ages but comparable strength-class at later age.

Valorization of wood chips ash as an eco-friendly mineral admixture in mortar mix design

Wood chips ash coming from biomass heating plant is studied as an eco-friendly mineral admixture in mortar mix design. The raw material was mechanically activated by milling in a vibratory disc mill to a degree of fineness comparable to cement. For the mortars with ash dosage, basic physical, mechanical, hygric, and thermal properties is accessed. The mortars with partial Portland cement replacement with wood chips ash exhibited good functional properties for all studied ash dosages. With increasing amount of the ash used, the average pore diameter decreased due to the partial filler effect of WCHA in mortar mix. The strength activity index was very high for all studied mortars and gave evidence of the wood chips ash pozzolanity. The pozzolan effectiveness coefficient varied from 1.52 to 0.59, which proved the pozzolanity of the studied ash and synergic effects in the Portland cement-ash-water system. The results of leaching tests showed, the chlorides contained in ash were safely immobilized in the silicate matrix. The environmental evaluation revealed decrease in both carbon dioxide production and energy consumption by the use of wood chips ash in mortar mix. For the mortar with 20% substitution of Portland cement with wood chips ash, it represents 15% of CO₂ and 16% of energy, as compared with the reference mortar mix. As the developed mortars possess good functional and environmental parameters the analyzed wood chips ash can be considered as an eco-efficient low-cost alternative to other pozzolans for production of blended binders.

[Long-term efficacy of TVT procedure in the treatment of stress urinary incontinence]

OBJECTIVE OF THE STUDY

The objective of the study was to ascertain the long-term efficacy of TVT procedure in the treatment of stress urinary incontinence.

DESIGN

Prospective observational study.

SETTINGS

Department of Gynecology and Obstetrics, First Faculty of Medicine, Charles University and the General University Hospital, Prague, EuroMISE centre of the Academy of Science, Prague.

MATERIAL AND METHODS

111 women with urodynamically proven stress incontinence who had undergone a TVT operation were included in the study; patients suffering with the mixed type of incontinence were included as well while a major prolapse of anterior vaginal wall (POP-Q II and more) was applied as the exclusion criterion. An overall pre-operation examination was carried out, including urodynamic and ultrasound examination, while the patients also completed an i-QOL quality of life questionnaire. The success of the operation was assessed using objective and subjective parameters. Occurrence of post-operation complications was correlated to the pre-operation mobility of the urethra, the surgeon who carried out the procedure, the post-operation position and mobility of the tape.

RESULTS

Of the 111 patients, 105 appeared for the 3-month post-operation check. Another 10 failed to appear for the one year check, and yet another 10 dropped out from the subsequent monitoring. A failure of the procedure was subsequently described for 9 patients (8.1%), who had to undergo another procedure: for 7 patients a re-operation was carried out to treat recurrence of the stress urinary incontinence, and for 2 patients discision of the tape was carried out for the reason of problems with urine retention and repeated infections of urinary tract. At the beginning of the post-operation monitoring 80% of patients were objectively stress continent. At the end of the monitoring, 74% of women were fully continent and 15% subjectively improved, with objectively proved SI. We have, however, observed a relatively higher increase in de novo urgency, where at the beginning of the monitoring, 10% of patients were thus affected, and at the end of the monitoring 22.5%. At the end of the monitoring the tape is 20% narrower and 2 mm closer to the urethra; otherwise its position unchanged. We have not proved that the pre-operation mobility of the urethra or choice of surgeon would affect the results of the operation. Neither have we proved any difference in the position and mobility of the tape in relation to the result of the operation.

CONCLUSIONS

In our group of patients we have proved very good long-term efficacy of the TVT operation for treatment of stress urinary incontinence. We have, nevertheless, observed a rather high increase in de novo occurrence of urgency at the end of the monitoring period - 21%. The increase of de novo urgency might be explained by the change in the position of the tape, which is closer to the urethra at the end of the monitoring.

Alterations induced by ischemic preconditioning on secretory pathways Ca2+-ATPase (SPCA) gene expression and oxidative damage after global cerebral ischemia/reperfusion in rats

Ischemic preconditioning (IPC) represents the phenomenon of CNC adaptation, which results in increased tolerance of CNS to lethal ischemia. Brain ischemia/reperfusion (IRI) initiates a catastrophic cascade in which many subcellular organelles play an important role. The Golgi apparatus, which is a part of secretory pathways (SP), represents the Ca(2+) store and regulates secretion of proteins for growth/reorganization of neuronal circuit by secretory Ca(2+)ATPases (SPCA1). The purpose of this study is to evaluate the effect of IRI and preconditioning on SPCA1 gene expression and oxidative damage after 4-vessel occlusion for 15 min and after being exposed to different reperfusion periods. Rats were preconditioned by 5 min of sub-lethal ischemia and 2 days later, 15 min of lethal ischemia was induced. Our experiments conclusively showed IRI-induced depression of SPCA activity and lipo- and protein oxidation in rat hippocampal membranes. IRI also activates the induction of SPCA1 gene expression in later reperfusion periods. IPC partially suppresses lipo- and protein oxidation in hippocampal membranes and leads to partiall rovery of the ischemic-induced depression of SPCA activity. In addition, IPC initiates earlier cellular response to the injury by the significant elevation of mRNA expression to 142% comparing to 1 h of corresponding reperfusion and to 11% comparing to 24 h of corresponding reperfusion, respectively. Similar patterns were observed on the translational level by Western blot analysis. Our results indicate the specific SPCA1 expression pattern in ischemic hippocampus. It also shows that the SPCA expression and the post-translational changes induced by ischemia are modulated by the IPC. This might serve to understand the molecular mechanisms involved in the structural integrity and function of the SP after ischemic challenge. It also suggests that there is a correlation of SPCA function with the role of SP in the response to pre-ischemic challenge.

Molecular mechanisms leading to neuroprotection/ischemic tolerance: effect of preconditioning on the stress reaction of endoplasmic reticulum

Ischemic tolerance can be developed by prior ischemic non-injurious stimulus preconditioning. The molecular mechanisms underlying ischemic tolerance are not yet fully understood. The purpose of this study is to evaluate the effect of preconditioning/preischemia on ischemic brain injury. We examined the endoplasmic reticulum stress response (unfolded protein response (UPR)) by measuring the mRNA and protein levels of specific genes such as ATF6, GRP78, and XBP1 after 15 min 4-VO ischemia and different times of reperfusion (1, 3, and 24 h). The data from the group of naïve ischemic rats were compared with data from the group of preconditioned animals. The results of the experiments showed significant changes in the gene expression at the mRNA level in the all ischemic/reperfusion phases. The influence of preischemia on protein level of XBP was significant in later ischemic times and at 3 h, the reperfusion reached 230% of the controls. The protein levels of GRP78 in preischemic animals showed a significant increase in ischemic and reperfusion times. They exceeded to 50% levels of corresponding naïve ischemic/reperfusion groups. Preconditioning also induced remarkable changes in the levels of ATF6 protein in the ischemic phase (about 170%). The levels of ATF6 remained elevated in earlier reperfusion times (37 and 62%, respectively) and persisted significantly elevated after 24 h of reperfusion. This data suggest that preconditioning paradigm (preischemia) underlies its neuroprotective effect by the attenuation of ER stress response after acute ischemic/reperfusion insult.

Can the preoperative value of VLPP and MUCP predict the postoperative quality of life?

OBJECTIVE

The aim of this study was to determine whether low values of VLPP (Valsava Leak Point Pressure) and low values of MUCP (Maximal Urethral Closure Pressure) before operation can predict quality of life (QOL) after anti-incontinence surgery.

METHODS

72 stress incontinent women were included in this study. All women underwent anti-incontinent surgery. We compared the quality of life using I-QOL (Incontinence Quality of Life) assessment with parameters of urodynamic measurement VLPP and MUCP The women filled in an I-QOL questionnaire before surgery and three month afterwards.

RESULTS

As in other studies, low preoperative value of the VLPP < or =60 cmH2O was not related to a statistically lower quality of life (average I-QOL for VLPP < or =60 cmH2O was 38.4 and 48.9 for VLPP > 60 cmH2O). We did not find statistically significant lower quality of life in women with MUCP < or =20 cmH2O (average I-QOL 38.2, and for MUCP > 20 39.7). The quality of life was significantly changed after successful anti-incontinent operation, but independently of the preoperative value of VLPP or MUCP, average I-QOL for VLPP < or =60 cmH2O was 81.5 and 82.8 for VLPP > 60 cmH20, for MUCP < or =20 cmH2O 79.5, and 86.4 for MUCP >20.

CONCLUSIONS

Low preoperative values of MUCP and VLPP did not correlate with QOL. Preoperative VLPP and MUCP do not predict the QOL after anti-incontinent surgery.

Weak VLPP and MUCP correlation and their relationship with objective and subjective measures of severity of urinary incontinence

The aims of the present study were to find the correlation between Valsalva leak-point pressure (VLPP) and cough leak-point pressure (CLPP) and to determine whether the water perfusion maximum urethral closure pressure (MUCP) correlates with VLPP. Seventy-nine women with previously untreated stress urinary incontinence were recruited to participate in a clinical study. Their mean age was 56.4 years, mean BMI was 27.8, and mean parity was 1.9. The mean values of VLPP and CLPP were 50.4 and 52.9 cm H(2)O, respectively. We did not find statistically significant differences in the mean values of VLPP and CLPP. The mean value of MUCP at rest was 44.2 cm H(2)O and the mean value of MUCP during maximal Valsalva maneuver was 37.2 cm H(2)O; with 500 ml of sterile saline in the bladder the difference between them is statistically significant. In the study group (n=79), 56 patients (77%) had low VLPP (< or =60 cm H(2)O), 21 patients (30%) had low MUCP (< or =30 cm H(2)O), and 8 patients had MUCP< or =20 cm H(2)O (all at rest). Of the 56 patients with low VLPP, 16 also had a low MUCP (< or =30 cm H(2)O). This study mainly compares two parameters-the MUCP and the VLPP. Based on our results we can conclude that there is no correlation between these parameters. MUCP measures urethral resistance at rest and VLPP measures urethral resistance during increased intra-abdominal pressure (Valsalva maneuver).

[Intrapartal fetal monitoring, sensitivity and specificity of methods]

OBJECTIVE

To evaluated sensitivity and specificity of presently used methods for intrapartal monitoring (CTG, FpO2 a STAN S-21) and their mutual comparison.

TYPE OF STUDY

A prospective study.

SETTING

Gynecological-Obstetrical Clinic, 1st Medical Faculty, Charles University and general Teaching Hospital, Prague.

METHOD

In 114 pregnant women with high-risk or pathological course of pregnancy the authors evaluated the capability of individual methods to predict intrapartal hypoxia, determined on the basis of postnatal evaluation of parameters observed (Apgar score in 1st minute, pH from umbilical artery, lactate levels in fetal blood, base excess (BE) and postpartum condition of fetus evaluated by a neonatologist). Each method was categorized according to its importance. The quality of individual methods was evaluated by means of their sensitivity and specificity as well as by the area under ROC (Receiver Operating Characteristic), i.e. AUC (Area under Curve). A similar or different prediction of the condition of the newborn by these individual methods was evaluated by the McNamara test of symmetry. In 50 deliveries performed by Cesarean section and 24 forceps deliveries the authors evaluated postnatal pH from umbilical artery and evaluation by Chi-square test. The women in childbed were infused with a tocolytic drug (hexoprenalin) before Cesarean section. All tests were performed at 5% level of significance.

RESULTS

Low level of Apgar score in the 1st minute and less) always indicated CTG, but also a large proportion of normal newborns. STAN, in contrast, well indicates all newborns with a normal point evaluation. The best balanced evaluation of the newborns is provided by FpO2 and there was a significant difference between CTG and FpO2. In evaluating pH from the umbilical artery (pH < 7.20), TCG proved to be most sensitive again but displayed low specificity. STAN was the best predictor of newborns with normal pH. In evaluating high levels of lactate (> 3.7mmol/L) and BE (> -10) and related demonstration of metabolic acidosis STAN proved to be the best predictor. The condition of the newborn evaluated by a neonatologist immediately after birth (medium or heavy depression) was best predicted by FpO2. In deliveries performed by Cesarean section and after the administration of tocolysis the postnatal pH was higher then in forceps deliveries without acute tocolysis. The occurrence of emergencies in the course of a pathological delivery in individual methods is as follows: CTG, FpO2 and STAN.

CONCLUSION

Even though CTG displays a very low specificity, this method should not be rejected, since it draws attention of the obstetrician very early to the possibility of developing hypoxia. FpO2 or STAN gives more precision to the situation and demarcates a correct moment for ending the delivery for the indication of fetus hypoxia intra partum. STAN is the best predictor for conditions of developing metabolic acidosis, evaluated postnatally by the level of lactate and BE in fetal blood.

[Changes in values of urethral closure pressure and its position after Burch colposuspension--predictive value of MUCP and VLPP for successful rate of this operation]

OBJECTIVE

To ascertain how the Burch colposuspension affects the value and position of MUCP in women without any previous uro-gynaecological operation. If possible, also to determine how the values of these parameters differ between groups of women who are free from problems after the operation, women who suffer urgency, and women who continue to suffer from stress incontinence. Furthermore, to ascertain whether the pre-operation values of MUCP and VLPP have any predictive value in determining the success rate of the Burch colposuspension. In addition, to ascertain whether in ultrasound examination we can observe any differences in urethra mobility between subgroups of women with various operation results.

DESIGN

Cross-sectional clinical study.

SETTINGS

Gynecological and Obstetric Clinic, First School of Medicine of Charles University and General Faculty Hospital, Prague.

MATERIALS AND METHODS

69 women after Burch colposuspension were included in the study. The average age was 51.9 (SD=7.8), BMI 26.9 (SD=3.9) and parity 2.1 (SD=0.6). A urodynamic examination was performed on the patient in the supine position, the urinary bladder was filled with 300 and 500 ml of normal saline solution. The pressure profile was examined at rest, at maximal Valsalva manoeuvre and while coughing. During examination of the urethral pressure profile we ascertained MUCP, the functional length of the urethra (FUL) and the relative distance of the MUCP point from the inner urethral orifice, which was calculated as the ratio of the MUCP position with respect to FUL. To determine position and mobility of urethra, perineal ultrasound examination was performed on patients in supine position, using Acuson 128 XP 10 equipment, 5 MHz convex abdominal probe. The bladder was filled with 300 ml of saline. Polar coordinates (distance p, angle gamma) were employed when determining the position of UVJ and of the centre of urethra, defined at 17 mm distance from inner urethral orifice. Of the 69 patients who underwent the operation 62 were examined after the operation, 48 subsequently had no problems (A), 5 suffered with de novo urgency or the urgency symptoms were worse (B), and in 9 (C) mild stress incontinence still persisted. The data were summarised as means with SD and as medians. Measurements before and after the operation were compared using the paired t-test and paired Wilcoxon test where appropriate. Subgroups A, B, C were compared using Kruskal-Wallis test or Pearson chi2-test where appropriate. The level of significance was set to 0.05. Statistical software R version 2.1.1 was used throughout the analysis.

RESULTS

No statistically significant changes were observed in values of MUCP before and after surgery, at rest, at Valsalva or while coughing, or with varying volumes of the urinary bladder of 300 and 500 ml before operation. Nor did we observe any difference in values of MUCP between the individual subgroups (A, B, C) of patients after surgery. We noted statistically significant differences in values of MUCP with varying volumes of the bladder of 300 and 500 ml after operation, the value of MUCP being higher with larger volume of the bladder at rest and while coughing. We observed statistically significant shortening of FUL after operation for bladder volume of 500 ml at rest only. The distance of the point of MUCP from the inner urethral orifice was significantly shorter only for bladder volume of 300 ml during Valsalva. No statistically significant differences in these parameters were observed between subgroups A, B, C. In the group of patients with MUCP before surgery < or = 30 cm H2O (10 out of 61 bladder volume 500 ml), 70% women were without problems after the operation. Among women with MUCP >30 cm H2O, 80% were without problems. This difference, however, was not statistically significant. The same is valid for women with VLPP < or = 60 cm H2O, 71% women were without problems after the operation and women with VLPP > 60 cm H2O where 91% were without problems; there was no statistically significant difference in success rate of this operation between these groups. The results of ultrasound examination imply that the operation change the position of UVJ or the middle of urethra at rest and during Valsalva manoeuvre. From the ultrasound parameters we can conclude that the operation changed the position of UVJ and the middle of the urethra forward at rest and restricted the mobility of the urethra during Valsalva manoeuvre.

CONCLUSIONS

The results of our study imply that Burch colposuspension, if properly placed and not tight, does not change MUCP either at rest or at Valsalva. The distance of the point of MUCP from the inner urethral orifice was significantly shorter only for bladder volume of 300 ml during Valsalva. No statistically significant differences in these parameters were observed between subgroups A, B, C. From the ultrasound parameters we can conclude that the operation changed the position of UVJ and the middle of the urethra forward at rest and restricted the mobility of the urethra during Valsalva maneuver. There is a slight paradoxical diminishing of the gamma angle during the Valsalva maneuver in the subgroups of patients with de novo urgency or where the urgency symptoms were worse (B), implying different movement of the urethra. Pre-operation values of MUCP and VLPP cannot be used to predict the effect of the operation, though we are aware of the fact that our results were ascertained on a rather small number of patients in the groups of patients with complications.

[Changes in values of urethral closure pressure and its position after TVT operation--predictive value of MUCP and VLPP for successful rate of this operation]

OBJECTIVE

To ascertain how the TVT (tension free vaginal tape) operation affects the value and position of MUCP in women without any previous uro-gynaecological operation. If possible, also to determine how the values of these parameters differ between groups of women who are free from problems after the operation, women who suffer urgency, and women who continue to suffer from stress incontinence. Furthermore, to ascertain whether the pre-operation values of MUCP and VLPP have any predictive value in determining the success rate of TVT operation. In addition, to ascertain whether in ultrasound examination we can observe any differences in urethra mobility between subgroups of women with various operation results.

DESIGN

Cross-sectional clinical study.

SETTINGS

Gynecological and Obstetric Clinic, First School of Medicine of Charles University and General Faculty Hospital, Prague.

MATERIALS AND METHODS

59 women after TVT operation were included in the study. The average age was 54.8 (SD = 10.5), BMI 27.6 (SD = 4.7) and parity L9 (SD = 0.6). A urodynamic examination was performed in the patient in the supine position, the urinary bladder was filled with 300 and 500 ml of normal saline solution. The pressure profile was examined at rest, at maximal Valsalva manoeuvre and while coughing. During examination of the urethral pressure profile we ascertained MUCP, the functional length of the urethra (FUL) and the relative distance of the MUCP point from the inner urethral orifice, which was calculated as the ratio of the MUCP position with respect to FUL. To determine the position and mobility of urethra, perineal ultrasound examination was performed in patients in supine position, using Acuson 128 XP 10 equipment, 5 MHz convex abdominal probe. The bladder was filled with 300 ml of saline. Polar coordinates (distance p, angle gamma) were employed when determining the position of UVJ and of the centre of urethra, defined at 17 mm distance from inner urethral orifice. Of the 59 patients who underwent the operation, 47 subsequently had no problems (A), 8 suffered with urgency symptoms (B), and in 4 (C) mild stress incontinence still persisted. The data were summarised as means with SD and as medians. Measurements before and after the operation were compared using the paired t-test and paired Wilcoxon test where appropriate. Groups A, B, C were compared using Kruskal-Wallis test or Pearson chi squared-test where appropriate. The level of significance was set to 0.05. Statistical software R version 2.0.1 was used throughout the analysis.

RESULTS

No statistically significant changes were observed in values of MUCP before and after surgery, at rest, at Valsalva or while coughing, or with varying volumes of the urinary bladder of 300 and 500 ml. Nor did we observe any difference in values of MUCP between the individual subgroups (A, B, C) of patients after surgery. We observed mild shortening of FUL at both volumes of the bladder at rest, but no change was observed at Valsalva. The distance of the point of MUCP from the inner urethral orifice was shifted by the operation, from 44% to 57% at rest; the small shift at Valsalva was not statistically significant. No statistically significant differences in these parameters were observed between subgroups A, B, C. In the group of patients with MUCP before surgery < or = 30 cm H2O, 67% women were without problems after the operation. Among women with MUCP > 30 cm H2O, 84% were without problems. This difference, however, was not statistically significant. The same is valid for women with VLPP < or = 60 cm H2O and VLPP > 60 cm H2O; between these groups there was no statistically significant difference in success rate of this operation. The results of ultrasound examination imply that the operation does not change the position of UVJ or the middle of urethra at rest; however, it affects the position of urethra at Valsalva manoeuvre, the scope of the movement being smaller after the operation.

CONCLUSIONS

The results of our study imply that the tape in TVT operation, if properly placed and not tight, does not change MUCP either at rest or at Valsalva. The operation slightly shortens the FUL at rest and causes a minor shift of the MUCP point towards the outer urethral orifice. The operation also does not change the position of the urethra at rest while restricting its movement during Valsalva manoeuver. For the group of patients who suffer urgency after the operation we observed slight change in direction of movement of UVJ during Valsalva manoeuver; UVJ being pulled lower and towards symphysis as compared to patients who are free from problems after the operation. Pre-operation values of MUCP and VLPP cannot be used to predict the effect of the operation, though we are aware of the fact that our results were ascertained on a rather small number of patients in the groups of patients with complications.

[Changes in vesicalization of urethra and bladder after TVT operation]

OBJECTIVE

The aim of our study was to asses the changes of the funnelling and the thickness of the urinary bladder after successful TVT procedure.

DESIGN

Prospective pilot study.

SETTING

Obstet. Gynecol Department, General Teaching hospital, Ist Medical Faculty, Charles University, Prague. EuroMISE Centre of the Charles University and Academy of Sciences, Prague, Czech Republic.

METHODS

In the prospective study were evaluated 90 women after successful TVT procedure (in the study was primarily included 101 women with proven stress urinary incontinence). Ultrasound scan was performed before surgery and 3-6 months after operation as a part of the complex urogynecological examination. Together with urethral mobility was assessed the funnelling at rest and at maximal Valsalva (the width and depth of visible opening of the proximal urethra). Thickness of the bladder wall was measured after emptying of the urinary bladder at three points (anterior, trigone and dome). The changes induced by the surgery were assessed. For the statistical evaluation t-test and Wilcoxone test were used.

RESULTS

The operation did not influence the proximal urethra at rest and significantly decreased funnelling during maximal Valsalva (width and depth). After the surgery there was a slight increase in the thickness of the bladder wall (anterior and trigone by 0.4 mm).

CONCLUSIONS

The action of the tape is more complex that only the compression of the urethra. The tape influenced the proximal urethra at maximal Valsalva, significantly decreased the funnelling.

[What ultrasound parameter is optimal in the examination of position and mobility of urethrovesical junction?]

OBJECTIVE

The aim of our study was to asses the validity of the ultrasound measurements, effect of the operator on the measurement and to find most accurate parameters for the monitoring of the bladder neck.

DESIGN

Pilot study.

SETTING

Obstet. Gynecol Department, General teaching hospital, Ist Medical Faculty, Charles University, Prague. EuroMISE centre of the Charles University and Academy of Sciences, Prague, Czech Republic.

METHODS

50 women were included in the study. The coordinate system was defined as follows: the x axis is the axis of the symphysis, with 0 at lower edge of the symphysis. The y axis is perpendicular to x. In this system the rotational angle gama (gamma) and distance (p) were measured. The measurements were taken at rest and during maximal Valsalva, repeated independently twice by each observer. Reliability of measurements was statistically tested.

RESULTS

The vector of movement (distance between the position of the point at rest and at maximal Valsalva) shows a typical error of 2.2 and 2.4 mm for Operator 1 and 2, respectively. For Operator 1 the shift between two measurements was 2.1 (SD 1.5 mm); for Operator 2 the value was 3.3 (SD=1.7mm), (differences between the operators are statistically significant). Differences at maximal Valsalva were similar. While the variability in measuremets is similar for both operators, this does not mean that final measurements are the same. The vector of the movement is not influenced by the variability of the measured parameters.

CONCLUSIONS

Differences between the operators are probably due to different placement of the axis of the symphysis, as there are minimal differences in vector of movement. Statistical evaluation indicates that the differences between the operators are statistically significant.

[Changes in urethra mobility after TVT operation]

OBJECTIVE

The aim of our study was to asses changes in the mobility of the whole urethra after successful TVT procedure.

DESIGN

Prospective pilot study.

SETTING

Obstet. Gynecol Department, General Teaching Hospital, 1st Medical Faculty, Charles University, Prague; EuroMISE Centre of the Charles University and Academy of Sciences, Prague, Czech Republic.

METHODS

101 women with proven stressed urinary incontinence were included in the study. After the TVT procedure 90 women were evaluated. As a part of the complex urogynecological investigation before surgery the transperineal ultrasound scan was performed in supine position, urinary bladder was filled to 300 ml. In the orthogonal system of coordinates the position and mobility of the whole urethra before surgery were assessed. Control examination was done 3-6 months after the surgery. The changes induced by the surgery were assessed. For the statistical evaluation t-test, Wilcox test, F test, Kruskal-Wallis test and ANOVA were used.

RESULTS

Surgery significantly decreased the mobility of the whole parts of the urethra during maximal Valsalva, but the position at rest is not influenced. The women with high urethral mobility have high mobility after the surgery. The operation was more effect in patients with high mobility. Never the less the change of relative mobility is the same in all women.

CONCLUSIONS

The information about the type of urethral mobility is important and may increase the success rate of TVT. Therefore the tension of the tape should be different for patients with different urethral mobility.

[Correlation between urethral mobility and maximal urethral closure pressure and Valsalva leak-point pressure in women with urinary stress incontinence]

OBJECTIVE

The aim of our study was to examine the relationship between urethral mobility in females and maximum urethral closure pressure (MUCP) at rest, and between urethral mobility and Valsalva leakpoint pressure (VLPP), and to determine whether urethral mobility correlates with MUCP and VLPP.

DESIGN

Cross-sectional clinical study.

SETTINGS

Gynecological and Obstetric Clinic, First School of Medicine of Charles University and General Faculty Hospital, Prague.

MATERIALS AND METHODS

Fifty-two women with previously untreated GSI were recruited to participate in a clinical study. Their mean age was 57.2, mean body mass index (BMI) 28, and mean parity 1.8. As part of the urethral pressure profile we determined MUCP and functional urethral length (FUL). VLPP was assessed during US examination using an ultrasound contrast medium and color Doppler velocimetry (CDV). A perineal ultrasound examination in patients in supine position (by Acuson 128 XP 10, curved array probe 5 MHz) to assess the position of UVJ and the middle of the urethra was performed. The bladder was filled with 300 ml sterile saline.

RESULTS

We did not find statistically significant differences in the mobility of urethrovesical junction (UVJ) and middle of the urethra between patients with low or normal VLPP at 5% level. On the other hand, we found statistically significant correlation in the mobility of urethrovesical junction (UVJ) and middle of the urethra with MUCP, where these parameters were assessed as mutually dependent values. However, if we set the borderline of UVJ hypermobility at 50 degrees or more (the difference in the value of gamma angle at maximum Valsalva maneuvre and at rest), and a low MUCP at equal to or less than 30 cm H2O, then we do not observe any correlation between the values of urethral mobility and MUCP, since combinations of these two values are too extreme.

CONCLUSIONS

This study mainly compares three parameters--the urethral mobility with MUCP and with VLPP. Based on our results we can conclude that there is no statistically significant correlation between hypermobility of the urethra and VLPP at 5% level. However, we did find a statistically significant correlation between MUCP and mobility of UVJ and middle of the urethra if the values for these parameters are not strictly assessed. If we set the borderline of UVJ hypermobility at 50 degrees or more and a low MUCP at equal to or less than 30 cm H2O, then we do not observe any correlation between the values of urethral mobility and MUCP.

Genetic determinants of folate status in Central Bohemia

Although several genetic factors have been implicated as determinants of blood folate concentration in various populations, their effect on folate status in the Czech population has not yet been examined. We explored whether blood folate concentrations in healthy Czech population are associated with polymorphisms in 5,10-methylenetetrahydrofolate reductase (MTHFR), folate hydrolase 1 (FOLH1), reduced folate carrier (RFC), and folate receptor (FOLR1) genes. In a cross-sectional study of 591 control subjects we determined genotypes by PCR-RFLP or ARMS-PCR methods, and plasma and erythrocyte folates by MEIA. The effect of different genotypes on folate status was examined by non-parametric tests and by regression analysis. The prevalence of the MTHFR 677C>T, MTHFR 1298A>C, FOLH1 1561C>T, RFC 80G>A and FOLR1 480G>C variant alleles was 0.34, 0.33, 0.05, 0.44 and 0.00, respectively. Only the MTHFR 677C>T variant was significantly associated with plasma folate concentrations (median 14.7, 14.0 and 12.2 nmol/l for the CC, CT and TT genotypes, respectively). Our study showed that among the five studied allelic variants, only the 677C>T polymorphism in the MTHFR gene is a significant genetic determinant of plasma folate concentrations in Czech population.

Genetic determinants of folate status in Central Bohemia

Although several genetic factors have been implicated as determinants of blood folate concentration in various populations, their effect on folate status in the Czech population has not yet been examined. We explored whether blood folate concentrations in healthy Czech population are associated with polymorphisms in 5,10-methylenetetrahydrofolate reductase (MTHFR), folate hydrolase 1 (FOLH1), reduced folate carrier (RFC), and folate receptor (FOLR1) genes. In a cross-sectional study of 591 control subjects we determined genotypes by PCR-RFLP or ARMS-PCR methods, and plasma and erythrocyte folates by MEIA. The effect of different genotypes on folate status was examined by non-parametric tests and by regression analysis. The prevalence of the MTHFR 677C>T, MTHFR 1298A>C, FOLH1 1561C>T, RFC 80G>A and FOLR1 480G>C variant alleles was 0.34, 0.33, 0.05, 0.44 and 0.00, respectively. Only the MTHFR 677C>T variant was significantly associated with plasma folate concentrations (median 14.7, 14.0 and 12.2 nmol/l for the CC, CT and TT genotypes, respectively). Our study showed that among the five studied allelic variants, only the 677C>T polymorphism in the MTHFR gene is a significant genetic determinant of plasma folate concentrations in Czech population.

[Correlation of maximum urethral closure pressure and Valsalva leak-point pressure in patients with genuine stress incontinence]

OBJECTIVE

The aim of our study was to find correlation between Valsalva leak-point pressure (VLPP) and cough leak-point pressure (CLPP) and to determine whether water perfusion maximum urethral closure pressure (MUCP) correlates with Valsalva leak-point pressure (VLPP).

DESIGN

Cross-sectional clinical study.

SETTINGS

Gynecological and Obstetric Clinic, 1st Medical Faculty, Charles University and General Faculty Hospital, Prague.

MATERIAL AND METHODS

Thirty women with previously untreated GSI were recruited to participate in a clinical study. Their mean age was 56.9, mean body mass index (BMI) 27.6, and mean parity 1.8. As part of the urethral pressure profile we determined MUCP and functional length (FUL) of the urethra. VLPP and CLPP were assessed during US examination using an ultrasound contrast medium and the color Doppler velocity (CDV). Funneling was described as the increase in distance between the inner edges of proximal urethra during Valsalva maneuver.

RESULTS

We did not find statistically significant differences in the mean value of VLPP and CLPP. The mean value of VLPP was 51.6 cm H2O (SD=26.5) and CLPP 53.1 cm H2O (SD=25.5). The mean values of MUCP were 39.7 cm H2O (SD=22.1) with 500 ml and 41.5 cm H2O (SD=22.7) with 300 ml of sterile saline; the difference between them is not statistically significant. In the study group (n=30), 22 patients had low VLPP (< or = 60 cm H2O). Only 8 patients had simultaneously MUCP < or = 30 cm H2O and of these patients only 2 had simultaneously MUCP < or = 20 cm H2O (the bladder volume 300 ml). Similar results were obtained with the bladder volume 500 ml. We did not find statistically significant differences in the funneling of proximal urethra between the groups of patients with low MUCP (< or = 30 cm H2O) and with higher MUCP (> 30 cm H2O) and between the groups of patients with low VLPP (< or = 60 cm H2O) and with higher VLPP (> 60 cm H2O).

CONCLUSIONS

This study mainly compares two parameters--the MUCP and the VLPP. Based on our results we support the theory that ISD has a multifactorial basis, and a low MUCP or a low VLPP derives from two different pathogenic mechanisms. We support the Pajoncini hypothesis that low VLPP correlates with a deficiency in mucosal sealing and compromise of the intrinsic proximal component at the level of the bladder neck, and low MUCP correlates with a deficiency at the level of the rhabdosphincter in the middle urethra. In the future we must establish the prognostic value of the VLPP and the MUCP in the postoperative follow-up.

[Trends and results of mitral valve surgery]

BACKGROUND

Retrospective study of 303 patients with mitral valve surgery operated in the last 7 years is evaluated. A mitral valve replacement was done in 271 patients (89.4%), mitral valve reconstruction in 32 patients (10.6%). Only the replacement of mitral valve was done in 70 patients (23.1%), replacement in combination with some other intervention, most frequently the revascularization was done in 27 patients.

METHODS AND RESULTS

The total mortality in mitral valve replacements was 7.7% with the prevalence of combined surgery, including the acute cases. Mortality for patients with prosthetics was 8.6% during 1996 to 98, and only 6.5% in the following years. From patients with the mitral reconstruction four has died (12.5%), all were acute or emergent cases with combined surgery. The average length of hospitalisation was 7.5 days. Postoperative Q-IM occurred in one patient (0.41%), revision for bleeding was necessary in 16 patients (5.3%), neurological complications developed in 14 patients (4.6%).

CONCLUSIONS

Results of early mitral replacements are comparable or in some combined surgeries better to the results given in the literature or in the international register. In the aetiology of disease, a comparative decrease of rheumatic origin and an increase of ischaemic and degenerative disorders become apparent. The paper demonstrates improving results in this field of cardiosurgery, shows the new trends in the development of surgical treatment of the mitral valve and it also stresses the necessity of early indication to the surgery.