Molecular characterization of Mycobacterium tuberculosis isolates from different regions of Bulgaria

Mycobacterium tuberculosis isolates from different regions of Bulgaria were studied by a variety of molecular typing tools. Based on spacer oligonucleotide typing (spoligotyping), the 113 strains were subdivided into 35 spoligotypes: 5 unique profiles and 15 profiles shared by two to 29 strains; the Hunter-Gaston diversity index (HGI) was 0.9. Comparison with the international database SITVIT2 at the Institut Pasteur de Guadeloupe showed the presence of two globally distributed shared types, ST53 (25.7%) and ST47 (6.2%). Nineteen (16.8%) and six (5.3%) strains belonged to the ST125 (LAM/S subfamily) and ST41 (LAM7_TUR subfamily) types described in SITVIT2 as ubiquitous/rare and ubiquitous/common types, respectively. Seven spoligoprofiles (12 strains) were not found in the database; two of them constituted new shared types. The Beijing genotype strains were not found in the studied collection in spite of close contacts with Russia in the recent and historical past. Additional subtyping by IS6110-restriction fragment length polymorphism (RFLP) and 12-locus mycobacterial interspersed repetitive unit (MIRU)-variable number of tandem repeat analyses were performed within selected spoligotypes. In particular, MIRU typing showed better discrimination within ST125 than IS6110-RFLP typing (HGI = 0.83 versus 0.39). A high gradient for ST125 in Bulgaria compared to its negligible presence in the global database and neighboring countries leads us to suggest a Bulgarian phylogeographic specificity of this spoligotype. To conclude, this first study of the Bulgarian M. tuberculosis population demonstrated its heterogeneity and predominance of several worldwide-distributed and Balkan-specific spoligotypes.     

Dopaminergic-induced changes in Mauthner cell excitability disrupt prepulse inhibition in the startle circuit of goldfish

Prepulse inhibition (PPI) is a widespread sensorimotor gating phenomenon characterized by a decrease in startle magnitude if a nonstartling stimulus is presented 20-1,000 ms before a startling stimulus. Dopaminergic agonists disrupt behavioral PPI in various animal models. This provides an important neuropharmacological link to schizophrenia patients that typically show PPI deficits at distinct (60 ms) prepulse-pulse intervals. Here, we study time-dependent effects of dopaminergic modulation in the goldfish Mauthner cell (M-cell) startle network, which shows PPI-like behavioral and physiological startle attenuations. The unique experimental accessibility of the M-cell system allows investigating the underlying cellular mechanism with physiological stimuli in vivo. Our results show that the dopaminergic agonist apomorphine (2 mg/kg body wt) reduced synaptic M-cell PPI by 23.6% (n = 18; P = 0.009) for prepulse-pulse intervals of 50 ms, whereas other intervals showed no reduction. Consistently, application of the dopamine antagonist haloperidol (0.4 mg/kg body wt) restored PPI to control level. Current ramp injections while recording M-cell membrane potential revealed that apomorphine acts through a postsynaptic, time-dependent mechanism by deinactivating a M-cell membrane nonlinearity, effectively increasing input resistance close to threshold. This increase is most pronounced for prepulse-pulse intervals of 50 ms (47.9%, n = 8; P < 0.05) providing a time-dependent, cellular mechanism for dopaminergic disruption of PPI. These results provide, for the first time, direct evidence of dopaminergic modulation of PPI in the elementary startle circuit of vertebrates and reemphasize the potential of characterizing temporal aspects of PPI at the physiological level to understand its underlying mechanisms.     

Haematological and iron-related parameters in male and female athletes according to different metabolic energy demands

We investigated the iron-related haematological parameters in both male and female athletes participating in different sporting disciplines necessitating different metabolic energy demands. A total of 873 athletes (514 males, mean age: 22.08 ± 4.95 years and 359 females, mean age: 21.38 ± 3.88 years) were divided according to gender and to the predominant energy system required for participation in sport (aerobic, anaerobic or mixed) and haematological and iron-related parameters were measured. For both male and female athletes, significant differences related to the predominant energy system were found at a general level: male (Wilks’ λ = 0.798, F = 3.047, p < 0.001) and female (Wilks’ λ = 0.762, F = 2.591, p < 0.001). According to the ferritin cutoff value of 35 μg/L, whole body iron and sTfR significantly differed in all three groups of male and female athletes (p < 0.001). The percentage of hypochromic erythrocytes in male athletes was significantly higher only in those who required an anaerobic energy source (p < 0.001), whilst in the females hypochromic erythrocytes (p < 0.001) and haemoglobin (anaerobic, p = 0.042; mixed, p = 0.006) were significantly different only in anaerobic and mixed energy source athletes. According to the ferritin cutoff value of 22 μg/L, in females, whole body iron, sTfR and hypochromic erythrocytes were significantly higher in all three groups of athletes than those below the aforementioned cutoff value (p < 0.001). We conclude that the predominant energy system required for participation in sport affects haematological parameters. sTfR and body iron proved to be reliable parameters for monitoring the dynamics of iron metabolism and could contribute to successful iron-deficiency prevention.     

Psychoeducational preparation of children for surgery: the importance of parental involvement

OBJECTIVE: To examine the effects of therapeutic play intervention on outcomes of children undergoing day surgery, and to highlight the importance of parental involvement in the psychoeducational preparation of children for surgery. METHODS: A randomized controlled trial, two group pre-test and repeated post-test, between subjects design was employed. Hong Kong Chinese children (7-12 years of age; n=203) admitted for elective surgery in a day surgery unit, along with their parents during a 13-month period, were invited to participate in the study. By using a simple complete randomization method, 97 of children with their parents were assigned to the experimental group receiving therapeutic play intervention, and 106 children with their parents were assigned to the control group receiving routine information preparation. RESULTS: The results showed that both children and their parents in the experimental group reported lower state anxiety scores in pre- and post-operative periods. Children in the experimental group exhibited fewer instances of negative emotional behaviors and parents in the experimental group reported greater satisfaction. The results, however, find no differences in children's post-operative pain between the two groups. CONCLUSION: The study provides empirical evidence to support the effectiveness of using therapeutic play intervention and the importance of parental involvement in the psychoeducational preparation of children for surgery. PRACTICE IMPLICATIONS: The findings heighten the awareness of the importance of integrating therapeutic play and parental involvement as essential components of holistic and quality nursing care to prepare children for surgery.     

Immobilization of aminothiols on poly(oxyalkylene phosphates). Formation of poly(oxyethylene phosphates)/cysteamine complexes and their radioprotective efficiency

The necessity to apply near-toxic amounts of radioprotective drugs to achieve adequate protection during radiation treatments represents a major problem in human medicine. One of the promising strategies to suppress the toxicity of these drugs involves their incorporation into biocompatible polymers. In this study cysteamine (Cy) was attached to poly(oxyethylene phosphate), POEP, via an ionic bond. Radioprotection of E. coli B cells by this substance and its acute toxicity on male C57 BL mice were measured. The toxicity of Cy immobilized within the poly(oxyethylene phosphate) was significantly lower in comparison to pure Cy while its radioprotective efficiency remained high at half the maximum tolerable dose. The high radioprotective efficiency of the Cy/POEP complexes was further confirmed on mice at different polymer molecular weight characteristics, drug immobilization degrees, application times, and doses. It was found that POEP with molecular weight 4700 Da and containing 24% repeating units with attached Cy has the highest protection potential combined with a depot effect.     

Propofol phosphate,a water-soluble propofol prodrug: in vivo evaluation

After a single IV injection of the water-soluble propofol prodrug propofol phosphate (PP) in mice, rats, rabbits, and pigs, propofol was produced rapidly (1-15 min), inducing dose-dependent sedative effects. In mice, the hypnotic dose (HD(50)), lethal dose (LD(50)), and safety index (defined as a ratio: LD(50)/HD(50)) were 165.4 mg/kg, 600.6 mg/kg, and 3.6, respectively. Propofol was produced with half-lives of 5.3 +/- 0.6 min in rats, 2.1 +/- 0.6 min in rabbits, and 4.4 +/- 2.4 min in pigs. The maximal concentration was dose and species dependent. The elimination half-life was 24 +/- 12 min in rats, 21 +/- 16 min in rabbits, and 225 +/- 56 min in pigs. Propofol generated from PP produced pharmacological effects similar to those described in the literature. We found a correlation between PP dose and duration of sedation with propofol concentrations larger than 1.0 microg/mL, which produced somnolence and sedation in rats and pigs. Adequate sedation and, at large enough doses, anesthetic-level sedation were produced after the administration of PP. Overall, PP, the water-soluble prodrug of propofol, seems to be a viable development candidate for sedative and anesthetic applications. IMPLICATIONS: Propofol phosphate, a water-soluble prodrug of the widely used IV anesthetic propofol, was developed and evaluated in mice, rats, rabbits, and pigs after IV injection. The results of the study clearly demonstrate the feasibility of the prodrug approach to achieve sedative and anesthetic levels of propofol in laboratory animals; this warrants further evaluation in humans.     

bcl-2 Expression in Endometrial Hyperplasia and Carcinoma

The bcl-2 gene codes for a protein which functions to inhibit apoptotic cell death. bcl-2 overexpression was originally described in follicular lymphoma, but more recently bcl-2 expression has been observed in a variety of other human neoplasms. In this study we used immunohistochemistry to examine bcl-2 protein expression in endometrial hyperplasia and carcinoma. bcl-2 protein was observed in 4/4 cases of complex hyperplasia, 1/4 cases of complex atypical hyperplasia, and 10/29 cases of carcinoma. The staining observed in the cases of complex atypical hyperplasia and carcinoma was focal and less intense than the reactivity of normal proliferative endometrium. We conclude that bcl-2 protein is seldom overexpressed in complex atypical hyperplasia or carcinoma of the endometrium. Rather, in many cases of endometrial carcinoma bcl-2 expression appears to be decreased.     

Arrhythmic cardiomyopathy. Case report

An 11 year-old boy was admitted with incessant sinus node reentrant tachycardia and secondary dilated arrhythmic cardiomyopathy, treated by radiofrequency ablation. Two years later he was admitted with incessant automatic atrial tachycardia and arrhythmic cardiomyopathy; a second catheter ablation procedure failed, but the third one, performed four month later, was successfully and resulted in a restoration of a normal sinus rhythm and a complete regression of arrhythmic cardiomyopathy.     

Mapping of maurotoxin binding sites on hKv1.2, hKv1.3, and hIKCa1 channels

Maurotoxin (MTX) is a potent blocker of human voltage-activated Kv1.2 and intermediate-conductance calcium-activated potassium channels, hIKCa1. Because its blocking affinity on both channels is similar, although the pore region of these channels show only few conserved amino acids, we aimed to characterize the binding sites of MTX in these channels. Investigating the pH(o) dependence of MTX block on current through hKv1.2 channels, we concluded that the block is less pH(o) - sensitive than for hIKCa1 channels. Using mutant cycle analysis and computer docking, we tried to identify the amino acids through which MTX binds to hKv1.2 and hIKCa1 channels. We report that MTX interacts with hKv1.2 mainly through six strong interactions. Lys(23) from MTX protrudes into the channel pore interacting with the GYGD motif, whereas Tyr(32) and Lys(7) interact with Val(381), Asp(363), and Glu(355), stabilizing the toxin onto the channel pore. Because only Val(381), Asp(363), and the GYGD motif are conserved in hIKCa1 channels, and the replacement of His(399) from hKv1.3 channels with a threonine makes this channel MTX-sensitive, we concluded that MTX binds to all three channels through the same amino acids. Glu(355), although important, is not essential in MTX recognition. A negatively charged amino acid in this position could better stabilize the toxin-channel interaction and could explain the pH(o) sensitivity of MTX block on current through hIKCa1 versus hKv1.2 channels.