Microimaging of transient guest profiles to monitor mass transfer in nanoporous materials.

The intense interactions of guest molecules with the pore walls of nanoporous materials is the subject of continued fundamental research. Stimulated by their thermal energy, the guest molecules in these materials are subject to a continuous, irregular motion, referred to as diffusion. Diffusion, which is omnipresent in nature, influences the efficacy of nanoporous materials in reaction and separation processes. The recently introduced techniques of microimaging by interference and infrared microscopy provide us with a wealth of information on diffusion, hitherto inaccessible from commonly used techniques. Examples include the determination of surface barriers and the sticking coefficient's analogue, namely the probability that, on colliding with the particle surface, a molecule may continue its diffusion path into the interior. Microimaging is further seen to open new vistas in multicomponent guest diffusion (including the detection of a reversal in the preferred diffusion pathways), in guest-induced phase transitions in nanoporous materials and in matching the results of diffusion studies under equilibrium and non-equilibrium conditions.

Uterine torsion in pregnancy. Case Report.

This paper describes a case of uterine torsion not only around the long, but also the horizontal axis, diagnosed post-operatively. The patient was 28-years-old, II/I in the 34th week of her gravidity. She was admitted due to amniotic fluid leak. Due to unsuccessful delivery induction using prostaglandins, a caesarean section was indicated to end the gravidity. Uterine torsion 180° around the longitudinal axis and 90° around the transversal axis was diagnosed during the surgery. The uterine wound was treated in accordance with guidelines and the patient was dismissed in a good condition. Control hysteroscopy and laparoscopy done after a time interval showed problem-free healing of the wound in the posterior uterine wall.

Pregnancy and delivery in Leyden-Möbius muscular dystrophy. Case Report.

Leyden-Möbius muscular dystrophy is an autosomal recessive hereditary disease of unknown aetiology; it is a congenital disorder of protein metabolism primarily affecting proximal muscle groups leading to progressive muscular dystrophy. It later spreads to the muscles of the pelvic floor and lower extremities. The estimated incidence is 1:200,000. This paper describe a case of pregnancy and delivery in woman with progressive Leyden-Moebius muscular dystrophy. Cesarean section was performed due to progression of the underlying disease. First postoperative day DIC occure and surgical revision of abdominal cavity was performed. Although the uterine suture was strong, diffuse bleeding was present. Blood was not coagulating. Supravaginal amputation of the uterus was performed including left-sided adnexectomy due to bleeding from the left ovarium. Due to the severity of the condition and assumed necessity of long-term controlled ventilation, the patient was transferred to the intensive medicine department. She was dismissed home after 91 days of hospitalisation. Gravidity in advanced muscular dystrophy is rare and associated with a high risk. Due to muscle weakness, diaphragm weakness, atrophy of individual muscle groups, spine deformities and often dislocation of thoracic organs, these patients cannot avoid the caesarean section to end their pregnancy, followed by prolonged intubation and controlled ventilation. During pregnancy, the growing uterus elevates the diaphragm and impairs breathing. Therefore, pregnancies in such patients will probably always have to be ended prematurely.

Efficacy of ursodeoxycholic acid in treating intrahepatic cholestasis of pregnancy: a meta-analysis.

BACKGROUND & AIMS: We performed a meta-analysis to evaluate the effects of ursodeoxycholic acid (UDCA) on pruritus, liver test results, and outcomes of babies born to women with intrahepatic cholestasis of pregnancy (ICP). METHODS: We performed a systematic review of 9 published, randomized controlled trials (3 double blinded) that compared the effects of UDCA to other drugs, placebo, or no specific treatment (controls) in patients with ICP. We analyzed data from 454 patients: 207 received only UDCA, 70 received only placebo, 42 received cholestyramine, 36 received dexamethasone for 1 week and then placebo for 2 weeks, 65 received S-adenosyl-methionine, and 34 received no specific treatment. To achieve consistency among end points, a standard questionnaire was sent to all corresponding authors. For each end point, we performed pooled analysis that compared the effects of UDCA with those of all controls and UDCA with those of placebos. RESULTS: In pooled analyses that compared UDCA with all controls, UDCA was associated with total resolution of pruritus (odds ratio [OR], 0.23; 95% confidence interval [CI], 0.07-0.74; P < .01), reduced pruritis (OR, 0.27; 95% CI, 0.13-0.55; P < .0001), normalization of serum levels of alanine aminotransferase (ALT) (OR, 0.23; 95% CI, 0.10-0.50; P < .001), decreased serum level of ALT (OR, 0.24; 95% CI, 0.11-0.52; P < .0001), reduced serum levels of bile acids (OR, 0.37; 95% CI, 0.19-0.75; P < .001), fewer premature births (OR, 0.44; 95% CI, 0.24-0.79; P < .01), reduced fetal distress (OR, 0.46; 95% CI, 0.25-0.86; P < .01), less frequent respiratory distress syndrome (OR, 0.30; 95% CI, 0.12-0.74; P < .01), and fewer neonates in the intensive care unit (OR, 0.49; 95% CI, 0.25-0.98; P = .046). In pooled analyses that compared the effects of UDCA with placebo, UDCA reduced pruritus (OR, 0.21; 95% CI, 0.07-0.62; P < .01), normalized (OR, 0.18; 95% CI, 0.06-0.52; P < .001) or decreased serum levels of ALT (OR, 0.12; 95% CI, 0.05-0.31; P < .0001), and reduced serum levels of bile acids (OR, 0.30; 95% CI, 0.12-0.73; P < .01). CONCLUSIONS: Based on a meta-analysis, UDCA is effective in reducing pruritus and improving liver test results in patients with ICP; UDCA therapy might also benefit fetal outcomes.

Micro-imaging of transient guest profiles in nanoporous host systems of cylindrical symmetry.

Nanoporous host materials giving rise to transient guest profiles of cylindrical symmetry during molecular uptake and release are shown to provide particularly advantageous conditions for the study of guest diffusion by micro-imaging. Considering zeolites of structure type DDR (Deca-dodecasil 3R) as a host system and short-chain length hydrocarbons as guest molecules, the benefits thus attainable in micro-imaging studies using interference microscopy are shown to include the determination of transient concentration profiles with improved accuracy, the option to overcome the disturbing impact of surface imperfections, and easy access to concentration-dependent diffusivities.

Delayed delivery of a twin - a hazard or an acceptable method? Prospective study.

OBJECTIVE: To examine the possibility of postponement of the delivery of fetus B after preterm delivery or late abortion of fetus A in multiple pregnancy. METHODS: Between January 2000 and September 2010, we tried to delay delivery of the second twin in 18 cases. Group A includes women that experienced a preterm premature rupture of the membranes in fetus A (PPROM), group B includes women who presented with regular uterine activity and the vaginal finding indicated unavoidable late miscarriage or preterm delivery. RESULTS: Thirteen (72.22%) of the 18 attempts were evaluated as unsuccessful. The interval of delay of delivery of fetus B ranged between 24 and 384 hours. Five cases were successful. CONCLUSION: Indication for applying this therapeutic procedure to a pregnant woman must be strictly selective. The procedure will be also in future more or less reserved for women in which subsequent pregnancy is for different reasons highly improbable.

Conducting labor in women with previous caesarean section in a low gestational week. A prospective case-controlled study.

AIMS: To assess whether vaginal labor after a previous caesarean section in a low gestational week performed by means of a high placed U-section technique could be recommended by obstetricians as a sufficiently safe method of choice for pregnant women. METHODS: Of 309 pregnant women with a history of a high placed U-section, 166 (53.7%) met the criteria for the subsequent vaginal delivery and agreed with it. In 78%, vaginal labor started spontaneously and in 22% it was induced due to postterm pregnancy or preterm rupture of membranes. RESULTS: Vaginal labor was successful in 72.3% of women. Deliveries after spontaneous onset of uterine contractions (80%) were considerably more successful. In the group of women with induced labor, the success rate was below 50%. Uterine rupture was not encountered in the study group. CONCLUSIONS: Vaginal labor after a previous high placed U-section is a sufficiently safe method of choice for selected groups of pregnant women, but it has to be mentioned that selecting criteria can only minimize and not entirely exclude the risk of uterine rupture.

Prospective randomised comparative study of the effect of buprenorphine, methadone and heroin on the course of pregnancy, birthweight of newborns, early postpartum adaptation and course of the neonatal abstinence syndrome (NAS) in women followed up in the outpatient department.

OBJECTIVE: The aim of the study was to evaluate the effect of substitution therapy in heroin addicted pregnant women on the course of pregnancy, perinatal outcomes and course of the neonatal abstinence syndrome. DESIGN OF THE STUDY: A five-year randomised prospective comparative study METHODS: The study was carried out in the period of 2002-2007. The group of patients included 147 i.v. heroin-addicted pregnant women. All of them were outpatients of our Perinatal Care Unit. Their daily dose of heroin was approximately lg. Later, 30 women were disqualified from the study for breaking the randomised criteria engagement. The substitution therapy in women who agreed to undergo it, started during the I. trimester of pregnancy. Finally, 47 heroin, 32 methadone and 38 buprenorphine addicted women were enrolled in the study. Birthweight of newborns was compared with the national birthweight tables. Severity and duration of neonatal abstinence syndrome (NAS) were evaluated by Finnegan s score scale. RESULTS: None of the women delivered before the end of 34th gestational week. We did not encounter any perinatal death or developmental defect. The lowest birthweight, the highest number of newborns with IUGR and the most numerous placental changes were found in the group of heroin-addicted women. The differences compared to the two groups receiving substitution therapy were statistically significant (p < 0.05). The severity and course of NAS were the most severe (p < 0.001) in newborns of women from the methadone group. CONCLUSION: Comparison of the groups of outpatients is in many ways questionable because of the restricted possibility of the patients' control. The lifestyle of addicted women has the same impact as the drug use alone. This is probably the main reason for differences in some of the monitored parameters between individual groups. Based on our results we can state that substitution therapy provides pregnant women with the possibility of social stabilization and adequate prenatal care. substitution therapy decreases the street heroin consumption. Methadone notably protracts the newborn's abstinence syndrome. With regard to this fact, attention has been recently focused on substitution with buprenorphine that seems to be from this viewpoint a more considerate option.

Uphill diffusion and overshooting in the adsorption of binary mixtures in nanoporous solids.

Under certain conditions, during binary mixture adsorption in nanoporous hosts, the concentration of one component may temporarily exceed its equilibrium value. This implies that, in contrast to Fick's Law, molecules must diffuse in the direction of increasing rather than decreasing concentration. Although this phenomenon of 'overshooting' has been observed previously, it is only recently, using microimaging techniques, that diffusive fluxes in the interior of nanoporous materials have become accessible to direct observation. Here we report the application of interference microscopy to monitor 'uphill' fluxes, covering the entire period of overshooting from initiation until final equilibration. It is shown that the evolution of the profiles can be adequately predicted from the single-component diffusivities together with the binary adsorption equilibrium data. The guest molecules studied (carbon dioxide, ethane and propene) and the host material (ZSM-58 or DDR) are of practical interest in relation to the development of kinetically selective adsorption separation processes.

Does asymptomatic carriage of FV Leiden and FII prothrombin mutations in heterozygous configuration pose an increased risk of thrombembolic complications in the course of pregnancy, labor and puerperium?

OBJECTIVE: To evaluate the course of pregnancy and puerperium in asymptomatic carriers of FV Leiden and FII prothrombin mutation in heterozygous configuration in terms of risk of thrombembolic disease (TED) and late pregnancy complications. To evaluate whether global prophylactic LMWH administration during pregnancy benefits these women. METHODS: We monitored the incidence of thrombembolic events and severe late pregnancy complications in 473 asymptomatic carriers of FV Leiden and FII prothrombin mutation in heterozygous configuration. In 253 women, preventive LMWH application was introduced already during pregnancy. In 220 women, the application of LMWH was commenced as late as on the delivery day. In both groups application of LMWH continued during the puerperium. RESULTS: The incidence of TED in the whole group of carriers of thrombophylic mutations accounted for 0.19%. The incidence of severe late pregnancy complications was low - 2.5% compared with general population of pregnant women (6.4%). CONCLUSIONS: No direct causal relationship was established between asymptomatic carriage of Leiden and prothrombin mutation in heterozygous configuration and the occurrence of severe late pregnancy complications. There was no benefit from general LMWH prophylaxis started as early as pregnancy in these women and thus we consider it unnecessary.

Micro-Imaging by Interference Microscopy: A Case Study of Orientation-Dependent Guest Diffusion in MFI-Type Zeolite Host Crystals.

Because of the small particle size, orientation-dependent diffusion measurements in microporous materials remains a challenging task. We highlight here the potential of micro-imaging by interference microscopy in a case study with MFI-type crystals in which, although with different accuracies, transient concentration profiles in all three directions can be observed. The measurements, which were performed with "rounded-boat" shaped crystals, reproduce the evolution patterns of the guest profiles recorded in previous studies with the more common "coffin-shaped" MFI crystals. The uptake and release patterns through the four principal faces (which in the coffin-shaped crystals extend in the longitudinal direction) are essentially coincident and there is no perceptible mass transfer in the direction of the long axis. The surface resistances of the four crystal faces through which mass transfer occurs are relatively small and have only a minor effect on the mass transfer rate. As a result of the pore structure, diffusion in the crystallographic c direction (which corresponds to the direction of the long axis) is expected to be much slower than in the transverse directions. This could explain the very low rate of mass transfer observed in the direction of the long axis, but it is also possible that the small end faces of the crystal may have high surface resistance. It is not possible to distinguish unequivocally between these two possibilities. All guest molecules studied (methyl-butane, benzene and 4-methyl-2-pentyne) show the same orientation dependence of mass transfer. The long 4-methyl-2-pentyne molecules would be expected to propagate at very different rates through the straight and sinusoidal channels. The coinciding patterns for uptake through the mutually perpendicular crystal faces therefore provide clear evidence that both the coffin shaped crystals and the rounded-boat-shaped crystals considered in this study, must be intergrowths rather than pure single crystals.

Randomized prospective comparative study of ursodeoxycholic acid and S-adenosyl-L-methionine in the treatment of intrahepatic cholestasis of pregnancy.

AIM: To compare the efficacy of the ursodeoxycholic acid (UDCA) and S-adenosyl-L-methionine (SAMe) monotherapy with their combined effect on intrahepatic cholestasis of pregnancy (ICP). PATIENTS AND METHODS: We studied singleton pregnancies at <36 weeks with a moderate or severe form of ICP between January 1999 and March 2004. Patients were randomized to either oral UDCA 3x250 mg daily or 500 mg SAMe twice daily in slow running infusion for twelve days followed by oral administration of 500 mg twice daily until delivery. Intensive hematological, biochemical and fetal monitoring were carried out. RESULTS: Of the 78 women enrolled, 25 received SAMe monotherapy, 26 received UDCA, and 27 received combined therapy. Groups were initially comparable in terms of gestational age, duration of therapy, parity and biochemical characteristics. All therapies improved the pruritus. The combined therapy and the monotherapy with UDCA (later) led to improving of the serum concentrations of bile acids and transaminases compared with SAMe monotherapy (P<0.01). Combined therapy led to a faster decrease of serum concentrations of bile acids and transaminases compared with UDCA monotherapy (borderline significance). Gestational ages were similar in all groups. No adverse effects were noted on the fetuses or neonates with either therapy. CONCLUSIONS: UDCA is an effective drug in the treatment of ICP, and combined with SAMe, has probably a synergistic effect on biochemical parameters. This mode of treatment seems more effective but the effect of the successful treatment on the fetus is unclear. Therefore, the ante- and intrapartum monitoring of the fetus should be part of the management of severe forms of ICP. The project is supported by IGA MZ CR (No. NH/7376-3).

Fetal anemia, thrombocytopenia, dilated umbilical vein, and cardiomegaly due to a voluminous placental chorioangioma. A case report.

We report a case of voluminous placental chorioangioma diagnosed by ultrasound and color Doppler imaging during the 20th week of pregnancy. The size of the tumor was enlarging progressively (up to 10 cm in the 32nd week), and during this time the signs of fetal intrauterine volume overload and blood cell consumption, such as cardiomegaly, umbilical vein dilation, hydramnios, anemia, and thrombocytopenia, were observed. In the 32nd week of pregnancy, the signs of uteroplacental insufficiency and fetal hypoxia appeared; therefore, the pregnancy was terminated by cesarean section, and a female infant weighing 1,870 g was delivered. She was discharged, fully recovered, after 48 days. Histopathological examination of the placental tumor showed a benign, vascular-type chorioangioma.