Poly(oxyethylene)s terminated at both ends with phosphonium ion end groups, 2. Properties

Poly(oxyethylene)s with number-average degrees of polymerization (DP_n) ranging from ≈ 6 to ≈ 80, terminated at both ends with phosphonium ion end groups (diionic poly-EO), have been prepared and characterized as described in the preceding paper. Viscosities of diionic poly-EO were measured, both in solution and in bulk. In chloroform solution, at low concentration (< 1 g/100 mL), the viscosity of diionic poly-EO was lower than the viscosity of nonionic (terminated with HO-groups) poly-EO of the same DP_n. At higher concentrations, the viscosity of diionic poly-EO exceeded that of nonionic poly-EO and increased sharply with increasing concentration. At the constant weight concentration of ≈4 g/100 mL, the viscosities of short-chain diionic poly-EO were higher and those of longer chain diionic poly-EO were lower than the viscosities of the nonionic poly-EO of the same chain lengths. These results were attributed to a predominant intramolecular aggregation of terminal ionic groups at low concentration of ionic groups in solution and predominant intermolecular aggregation at higher concentration of ionic groups. The results of bulk viscosity measurements as well as the results of differential scanning calorimetry measurements of the dependence of the glass transition temperature on the DP_n of diionic poly-EO indicated that in bulk physically cross-linked networks were formed, due to intermolecular aggregation of terminal ionic groups.     

Polymerization of 3,3-bis (chloromethyl) oxetane catalyzed by i-Bu3Al in bulk. I. The conditions of high polymer formation

The high temperature (up to 220°C.) polymerization of 3,3-bis(chloromethyl)oxetane catalyzed by i-Bu₃Al was investigated. The conversion-time curves are of the autocatalytic type and the molecular weight increases lineary with conversion up to the point at which for lower temperatures, e.g. 60–80°C., the whole polymer becomes insoluble. An alternative explanation of this phenomenon is proposed; the formation of insoluble product is related to the entanglement of macromolecules of very high molecular weight and or macrocycle formation in the degradative chain transfer to polymer. The phenomenon of insoluble products formation was never observed at higher temperatures (> 150°C.). The dependence of molecular weight on catalyst and impurity concentrations as well as on the polymerization temperature was investigated. It was shown that the high molecular weight product (\documentclass{article}\pagestyle{empty}\begin{document}$\overline {DP}$\end{document} = 1000–1500) can be produced at 180–220°C. even at rather high impurity level.     

Up-regulation of tRNA biosynthesis affects translational readthrough in maf1-delta mutant of Saccharomyces cerevisiae

Maf1p is a negative effector of RNA polymerase III in yeast. The maf1-delta mutation caused an increase in the level of cellular tRNAs, but a decrease of translational readthrough at nonsense codons. Using the lacZ- luc dual gene reporter system, we detected an almost twofold diminution of UAA and UAG readthrough in maf1-delta compared with the parental strain. The maf1-delta mutation did not affect the rate of protein biosynthesis and growth at standard conditions, but resulted in temperature-sensitive growth on non-fermentable carbon sources. We examined the correlation of the temperature sensitive and antisuppression phenotypes of maf1- Delta using a colour phenotype assay in the ade2-1 SUP11 strain. Antisuppression, but not the temperature-sensitive growth defect, was compensated either by increased dosage of SUP11or by [PSI(+)], the prion form of the translation termination factor Sup35p. Summarizing, the elevated tRNA levels in maf1- Delta increase translational fidelity and, independently, affect growth under special conditions.     

Solitary splenic metastases from lung cancer--one-time surgical procedure

Splenic metastasis from lung cancer is a rare clinical event, most often diagnosed at the time of an autopsy. We report a case of a 68 year old man with splenic metastasis from the primary lung cancer. Staging procedures before the resection of the primary lung tumor detected the splenic lesion. Upper left lobectomy and splenectomy were done by the left postero-lateral thoracotomy with phrenotomy. The rarity of solitary spleen metastasis from lung cancer and the treatment are discussed.     

Visualisation of the extent of damage in a rat spinal cord injury model using MR microsopy of the water diffusion tensor

Magnetic Resonance Diffusion Tensor Imaging (DTI) of the control and traumatic injured spinal cord of a rat in vitro is reported. Experiments were performed on excised spinal cords from 10 Wistar rats, using a home-built 6.4 T MR microscope. MRI and histopathological results were compared. Presented results show that DTI of the spinal cord, perfused with formalin 10 minutes after the injury, can detect changes in water diffusion in white matter (WM) and in gray matter (GM), in areas extending well beyond the region of direct impact. Histology of neurons of the GM shows changes that can be attributed to ischemia. This is in agreement with the observed decrease of diffusion in the injured regions, which may be attributed to the cytotoxic edema due to ischemia. However, the diffusion changes in highly anisotropic WM seem to be caused by a direct action of mechanical force of impact, which significantly distorts the nerve fibers.     

Methylation and Expression of FTO and PLAG1 Genes in Childhood Obesity: Insight into Anthropometric Parameters and Glucose–Lipid Metabolism

The occurrence of childhood obesity is influenced by both genetic and epigenetic factors. FTO (FTO alpha-ketoglutarate dependent dioxygenase) is a gene of well-established connection with adiposity, while a protooncogene PLAG1 (PLAG1 zinc finger) has been only recently linked to this condition. We performed a cross-sectional study on a cohort of 16 obese (aged 6.6–17.7) and 10 healthy (aged 11.4–16.9) children. The aim was to evaluate the relationship between methylation and expression of the aforementioned genes and the presence of obesity as well as alterations in anthropometric measurements (including waist circumference (WC), body fat (BF_kg) and body fat percent (BF_%)), metabolic parameters (lipid profile, blood glucose and insulin levels, presence of insulin resistance) and blood pressure. Expression and methylation were measured in peripheral blood mononuclear cells using a microarray technique and a method based on restriction enzymes, respectively. Multiple regression models were constructed to adjust for the possible influence of age and sex on the investigated associations. We showed significantly increased expression of the FTO gene in obese children and in patients with documented insulin resistance. Higher FTO expression was also associated with an increase in WC, BF_kg, and BF_% as well as higher fasting concentration of free fatty acids (FFA). FTO methylation correlated positively with WC and BF_kg. Increase in PLAG1 expression was associated with higher BF%. Our results indicate that the FTO gene is likely to play an important role in the development of childhood adiposity together with coexisting impairment of glucose-lipid metabolism.     

The impact of location and patency of the arteriovenous fistula on quality of life of kidney transplant recipients

BackgroundArteriovenous fistulae (AVFs) may remain patent after kidney transplantation (KTx), contributing to maladaptive cardiac remodeling. The flow in AVFs is associated with the diameter of its vessels and thus with the AVF location. The main objective of this study is to assess the influence of AVF location and its patency on the self-reported quality of life (QOL) of kidney transplant recipients (KTRs) with past history of hemodialysis.MethodsTo gain clinical data, during a scheduled visit, 353 KTRs were asked to fill out an anonymous questionnaire. From this group, 284 respondents were found eligible for analysis. The outcome was defined as prevalence of symptoms and health status, measured with the Left Ventricular Dysfunction-36 (LVD-36) Questionnaire in symptomatic patients.ResultsThe hemodialysis patients (n = 243) were divided into two groups according to AVF location, i.e., DAVF – distally located AVF – (n = 174) and PAVF – proximally located AVF – (n = 69). The proportion of patients with heart failure (HF) was higher in PAVF group (24% vs. 12%, p = 0.0482). In the multivariable regression, PAVF, serum creatinine levels, and the presence of HF or coronary artery disease (CAD) remained independent predictors of lower functional capacity. Among patients with heart disease, the presence of active AVF was independently associated with worse functional outcome (higher LVD-36 scores).ConclusionsThe influence of persistent PAVF in KTRs seems to be unfavorable, especially when coexisting with CAD or HF. Abbreviations: AVF arteriovenous fistula; BMI body mass index; CAD coronary artery disease; D-AVF distally-located arteriovenous fistula; EC exercise capacity; HD hemodialysis; HF heart failure; KTx kidney transplantation; KTR kidney transplant recipient; LVD-36 Left Ventricle Disfunction – 36; LVEF left ventricle ejection fraction; LVH left ventricle hypertrophy; NYHA New York Heart Association; P-AVF proximally located arteriovenous fistula; PD peritoneal dialysis; PRO patient-reported outcomes; QOL quality of life.     

The central action of pizotifen

The central action of the potential antidepressant drug pizotifen (Sandomigran) was studied in mice, rats and rabbits. Pizotifen in doses up to 10 mg/kg i.p. was ineffective in classic tests for antidepressant activity. It neither antagonized the effects of reserpine in rats (hypothermia, ptosis) nor potentiated the effects of amphetamine (in mice and rats), nialamide or L-dopa (in mice) on locomotor activity. However, its antidepressant activity was found in the despair test in rats.On the other hand, pizotifen inhibited the head twitch reaction induced by L-5-hydroxytryptophan in mice (ED₅₀=0.009 mg/kg, i.p.) and by 5-methoxytryptamine (+tranylcypromine) in rats (ED₅₀=0.45 mg/kg, i.p.). It also antagonized tryptamine-induced clonic convulsions of fore-paws in rats (ED₅₀=0.35 mg/kg, i.p.), and in doses of 5–10 mg/kg s.c. inhibited hyperthermia produced by LSD in rabbits. Finally, pizotifen (0.1–0.3 mg/kg, i.v.) inhibited or abolished LSD- or quipazine-induced stimulation of the hind limb flexor reflex of spinal rats; the above effect was not due to noradrenolytic action of the drug. These results suggest that pizotifen strongly blocks the central postsynaptic serotonin receptors.     

Kniegelenksmeniskusverletzungen im Kindesalter mit Berücksichtigung der Nachuntersuchungen

Zusammenfassung Es wurden 30 Fälle der Kniegelenksmeniskusverletzung im Kindesalter vorgestellt, die operativ behandelt waren. 20 der Behandelten wurden nach 1–12 Jahren nach dem operativen Eingriff nachuntersucht. Es wurden n die Ätiologie, der Verletzungsmechanismus und der klinische Befund besprochen. Die klinische und radiologische Nachuntersuchung ermöglichte die morphologische und funktionelle Auswertung des Kniegelenks nach der Meniskusverletzung.

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Injury of the semilunar cartilages of the knee-joint in childhood

Summary In the paper, 30 patients at the age of 5 till 14 with injuries of the semilunar cartilages of the knee-joint, are presented. All the children were subjected to surgery, and 20 of them underwent same examinations performed in a delay of 1 to 12 years after they had been operated. Both etiology and the injury mechanism subjects are hadled together with the clinical pictures, specific to the age of the young patients. Basing on the clinical and X-ray examinations, the state of the morphological and functional condition of the knee of a child after semilunar cartilage had been removed, was considered and estimated.

     

Interactions between non-barbiturate injectable anesthetics and conventional antiepileptic drugs in the maximal electroshock test in mice--an isobolographic analysis.

The aim of this study was the isobolographic evaluation of interactions between three non-barbiturate intravenous anesthetics and conventional antiepileptic drugs in the maximal electroshock-induced seizures in mice. Electroconvulsions were produced by means of an alternating current (ear-clip electrodes, 0.2-s stimulus duration, tonic hindlimb extension taken as the endpoint). Adverse effects were evaluated in the chimney test (motor performance) and passive avoidance task (long-term memory). Plasma levels of antiepileptic drugs were measured by immunofluorescence. Obtained results indicate that ketamine acts synergistically with valproate and carbamazepine. Also the combinations of propofol and valproate or phenobarbital led to synergistic interactions. An antagonism was found between etomidate and carbamazepine or phenobarbital. On the other hand, interactions between diphenylhydantoin and injectable anesthetics proved to be additive. The only exception was the combination of diphenylhydantoin and propofol (1:3). Pharmacokinetic phenomena do not seem to interfere with the observed interactions, since none of anesthetics influenced the free plasma concentrations of antiepileptic drugs. Referring to undesired effects, only propofol impaired long-term memory. Although propofol did not disturbed motor coordination, it enhanced motor impairment caused by carbamazepine and diphenylhydantoin. Results of the present study suggest that etomidate needs to be avoided in epileptic patients due to a possibility of negative interactions with some antiepileptic drugs and seizure precipitation.