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1.
Eur Rev Med Pharmacol Sci ; 26(3): 810-819, 2022 Feb.
Article in English | MEDLINE | ID: mdl-35179747

ABSTRACT

OBJECTIVE: The aim of this study was to compare psychosocial functioning as well as the quality of life of young adults after orthognathic procedures and healthy individuals. MATERIALS AND METHODS: The study included 124 respondents aged between 16 and 25 years, 65 of whom had undergone orthognathic surgeries, and 59 healthy individuals. The study was carried out using a diagnostic poll method with both standardized tools and the author's own questionnaires: Authors own questionnaire, 'How do you cope?' Questionnaire, Emotional Intelligence INTE Questionnaire, The List of Personal Values (LOPV), The Satisfaction with Life Scale (SWLS), and The Short Form Health Survey (SF-36 v2). RESULTS: Patients after orthognathic procedures more frequently actively dealt with problems and sought social support rather than concentrating on emotions in terms of dispositional ways of coping with difficult situations. A statistically significant difference was established in the concentration on emotions subscale (CoE) for which lower average value was observed in the study group. Study and control groups differed in terms of the ability to recognise, understand, and control their own and other's emotions. CONCLUSIONS: Respondents from both groups similarly perceived personal values pointing to love and friendship, health, intelligence as well as happiness as the most important ones. Both patients after orthognathic procedures and healthy ones assessed their life satisfaction on an average level. A link between the choice of the strategy of coping with difficult situations and the fact of having undergone an orthognathic procedure exists. Patients after surgical procedures, in comparison with healthy individuals, less frequently opted for the concentration on emotions (CoE) strategy.


Subject(s)
Orthognathic Surgery , Orthognathic Surgical Procedures , Adaptation, Psychological , Adolescent , Adult , Humans , Orthognathic Surgical Procedures/psychology , Psychosocial Functioning , Quality of Life/psychology , Surveys and Questionnaires , Young Adult
2.
Eur Rev Med Pharmacol Sci ; 25(24): 7903-7912, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34982453

ABSTRACT

OBJECTIVE: Craniofacial defects are functional imbalances of their structures. Impaired speech and facial deformities hinder adolescents' ability to fulfill social roles. The optimal age for a patient to be qualified for orthognathic surgery is between 16 and 30 years. PATIENTS AND METHODS: The study sample consisted of 65 patients after bimaxillary orthognathic surgery performed in the Head and Neck Surgery Department with Craniofacial Surgery Subdivision in Provincial Specialist Children's Hospital in Olsztyn. The research tools used in the study were: the author's questionnaire concerning sociodemographic data, and the following standardized questionnaires: the 'How Do You Cope?' questionnaire, the Emotional Intelligence Questionnaire (INTE), the List of Personal Values (LOPV), the Short Form Health Survey (SF-36), the Satisfaction With Life Scale (SWLS). RESULTS: The study demonstrated a positive correlation between the levels of QoL and general life satisfaction according to the SWLS. A negative relationship was observed between QoL and dispositional coping according to the 'How do you cope?' questionnaire. The emotion-focused coping strategy in the category of dispositional coping negatively correlated with eight of the SF-36 domains. CONCLUSIONS: Young adults after bimaxillary orthognathic procedures show a high level of QoL. The level of QoL depends, among others, on the level of emotional intelligence. Better ability to recognize emotions is associated with higher QoL in the domain of general health.


Subject(s)
Orthognathic Surgical Procedures/psychology , Adaptation, Psychological , Adolescent , Adult , Emotional Intelligence , Female , Humans , Male , Personal Satisfaction , Postoperative Period , Quality of Life , Surveys and Questionnaires , Young Adult
3.
J Hosp Infect ; 104(4): 522-528, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32035121

ABSTRACT

BACKGROUND: Ventilator-associated pneumonia surveillance is used as a quality indicator due to concerns that some cases may be preventable and may contribute to mortality. Various surveillance criteria exist for the purposes of national reporting, but a large-scale direct comparison has not been conducted. METHODS: A prospective cohort study applied two routinely used surveillance criteria for ventilator-associated pneumonia from the European Centre for Disease Control and the American Centers for Disease Control to all patients admitted to two large general intensive care units. Diagnostic rates and concordance amongst diagnostic events were compared. FINDINGS: A total of 713 at-risk patients were identified during the study period. The European surveillance algorithm returned a rate of 4.6 cases of ventilator-associated pneumonia per 1000 ventilation days (95% confidence interval 3.1-6.6) and the American surveillance system a rate of 5.4 (3.8-7.5). The concordance between diagnostic events was poor (Cohen's Kappa 0.127 (-0.003 to 0.256)). CONCLUSIONS: The algorithms yield similar rates, but the lack of event concordance reveals the absence of inter-algorithm agreement for diagnosing ventilator-associated pneumonia, potentially undermining surveillance as an indicator of care quality.


Subject(s)
Pneumonia, Ventilator-Associated/epidemiology , Public Health Surveillance/methods , Sentinel Surveillance , Adult , Aged , Algorithms , Female , Hospitals , Humans , Male , Middle Aged , Pneumonia, Ventilator-Associated/microbiology , Prospective Studies , Scotland/epidemiology
4.
Reprod Fertil Dev ; 30(4): 609-618, 2018 Mar.
Article in English | MEDLINE | ID: mdl-28917264

ABSTRACT

Kisspeptin (kp) is considered to be one of the major regulators of the induction of pubertal events via the activation of the gonadotrophin-releasing hormone-LH system. The aim of the present study was to analyse expression of immunoreactive (ir) kp in the hypothalamic neurons of female lambs from the neonatal to the peripubertal period (5 days to 32 weeks) in relation to the plasma LH pattern using immunohistochemistry and image analysis. Hypothalami were collected from female lambs (n=33) from the infantile, juvenile, prepubertal and peripubertal periods. The population of kp-ir perikarya was detected mainly in the arcuate nucleus and their number increased gradually from 5 to 16 weeks of age and was maintained at a high level up to the peripubertal stage. This was reflected by the significant (P<0.05) gradual increase in the percentage of hypothalamic area occupied by kp-ir neurons and increase in the number of kp-ir perikarya within the arcuate nucleus. The same pattern of kp immunoreactivity was observed in the median eminence. Plasma LH concentration increased from Week 5 to Weeks 12-16 and further increased at Week 32. LH pulse frequency increased from Week 5 to 32 (P<0.05). Thus, changes in kp expression reflected changes in the LH pattern during lamb growth. The data obtained provide evidence about the participation of kp in the mechanisms of ontogenic development of ovine reproductive processes.


Subject(s)
Hypothalamus/metabolism , Kisspeptins/metabolism , Luteinizing Hormone/blood , Neurons/metabolism , Animals , Female , Immunohistochemistry , Progesterone/blood , Sheep
5.
Genes Immun ; 15(7): 500-5, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25030430

ABSTRACT

The host genetic basis of mixed cryoglobulin vasculitis is not well understood and has not been studied in large cohorts. A genome-wide association study was conducted among 356 hepatitis C virus (HCV) RNA-positive individuals with cryoglobulin-related vasculitis and 447 ethnically matched, HCV RNA-positive controls. All cases had both serum cryoglobulins and a vasculitis syndrome. A total of 899 641 markers from the Illumina HumanOmni1-Quad chip were analyzed using logistic regression adjusted for sex, as well as genetically determined ancestry. Replication of select single-nucleotide polymorphisms (SNPs) was conducted using 91 cases and 180 controls, adjusting for sex and country of origin. The most significant associations were identified on chromosome 6 near the NOTCH4 and MHC class II genes. A genome-wide significant association was detected on chromosome 6 at SNP rs9461776 (odds ratio=2.16, P=1.16E-07) between HLA-DRB1 and DQA1: this association was further replicated in additional independent samples (meta-analysis P=7.1 × 10(-9)). A genome-wide significant association with cryoglobulin-related vasculitis was identified with SNPs near NOTCH4 and MHC Class II genes. The two regions are correlated and it is difficult to disentangle which gene is responsible for the association with mixed cryoglobulinemia vasculitis in this extended major histocompatibility complex region.


Subject(s)
Cryoglobulins/analysis , Hepatitis C/complications , Polymorphism, Single Nucleotide , Vasculitis/genetics , Case-Control Studies , Chromosomes, Human, Pair 6/genetics , Cryoglobulinemia/etiology , Cryoglobulinemia/genetics , Female , Genes, MHC Class II , Genome-Wide Association Study , Humans , Male , Proto-Oncogene Proteins/genetics , Receptor, Notch4 , Receptors, Notch/genetics , Vasculitis/etiology
6.
Genes Immun ; 15(4): 241-6, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24622687

ABSTRACT

Hepatitis C virus (HCV) infects an estimated 3% of the global population with the majority of individuals (75-85%) failing to clear the virus without treatment, leading to chronic liver disease. Individuals of African descent have lower rates of clearance compared with individuals of European descent and this is not fully explained by social and environmental factors. This suggests that differences in genetic background may contribute to this difference in clinical outcome following HCV infection. Using 473 individuals and 792,721 single-nucleotide polymorphisms (SNPs) from a genome-wide association study (GWAS), we estimated local African ancestry across the genome. Using admixture mapping and logistic regression, we identified two regions of interest associated with spontaneous clearance of HCV (15q24, 20p12). A genome-wide significant variant was identified on chromosome 15 at the imputed SNP, rs55817928 (P=6.18 × 10(-8)) between the genes SCAPER and RCN. Each additional copy of the African ancestral C allele is associated with 2.4 times the odds of spontaneous clearance. Conditional analysis using this SNP in the logistic regression model explained one-third of the local ancestry association. Additionally, signals of selection in this area suggest positive selection due to some ancestral pathogen or environmental pressure in African, but not in European populations.


Subject(s)
Black People/genetics , Genome-Wide Association Study , Hepatitis C, Chronic/genetics , Polymorphism, Single Nucleotide , Remission, Spontaneous , Alleles , Carrier Proteins/genetics , Chromosomes, Human, Pair 15/genetics , Chromosomes, Human, Pair 20/genetics , Female , Hepatitis C, Chronic/ethnology , Humans , Male
7.
Opt Lett ; 36(19): 3717-9, 2011 Oct 01.
Article in English | MEDLINE | ID: mdl-21964074

ABSTRACT

We demonstrate a method for the efficient modulation of optical wavelengths around 1550 nm in silicon waveguides. The amplitude of a propagating signal is mediated via control of the charge state of indium centers, rather than using free-carriers alone as in the plasma-dispersion effect. A 1×1 switch formed of an integrated p-i-n junction in an indium-doped silicon on insulator (SOI) waveguide provides 'normally-off' silicon absorption of greater than 7 dB at zero bias. This loss is decreased to 2.8 dB with application of a 6 V applied reverse bias, with a power consumption of less than 1 µW.

8.
Opt Express ; 17(21): 18571-80, 2009 Oct 12.
Article in English | MEDLINE | ID: mdl-20372587

ABSTRACT

The control of defect mediated optical absorption at a wavelength of 1550 nm via charge state manipulation is demonstrated using optical absorption measurements of indium doped Silicon-On-Insulator (SOI) rib waveguides. These measurements introduce the potential for modulation of waveguide transmission by using the local depletion and injection of free-carriers to change deep-level occupancy. The extinction ratio and modulating speed are simulated for a proposed device structure. A 'normally-off' depletion modulator is described with an extinction coefficient limited to 5 dB/cm and switching speeds in excess of 1 GHz. For a carrier injection modulator a fourfold enhancement in extinction ratio is provided relative to free carrier absorption alone. This significant improvement in performance is achieved with negligible increase in driving power but slightly degraded switching speed.

9.
J Hazard Mater ; 136(3): 770-5, 2006 Aug 25.
Article in English | MEDLINE | ID: mdl-16469435

ABSTRACT

Platinum has been widely applied in catalytic industry and the recovery of noble metals from industrial wastes becomes an economic issue. The laboratory studies of platinum(IV) microquantities removal from 1M aluminium, copper, iron, nickel and zinc chloride solutions in 0.1M hydrochloric acid solutions on the anion exchanger Duolite S 37 of the functional secondary and tertiary amine groups were carried out. For this anion exchanger the fraction extracted values (%E, Pt(IV)) as well as the sorption isotherms were determined depending on the kind of aqueous phase and phase contact time. Moreover, the bed and weight distribution coefficients as well as working and total ion-exchange capacities were calculated from the platinum(IV) breakthrough curves. Kinetic parameters were determined.


Subject(s)
Metals/analysis , Platinum/analysis , Resins, Synthetic/chemistry , Algorithms , Anion Exchange Resins , Indicators and Reagents , Solutions
10.
J Pept Sci ; 7(9): 466-73, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11587185

ABSTRACT

A series of terminally blocked dipeptides containing C-terminal N-phosphonomethylglycine (glyphosate, an extremely effective non-selective post-emergence herbicide) have been synthesized by a solution method. The presence of their two conformers, cis (syn) and trans (anti), was shown in solutions by NMR spectroscopy. Molecular structures of the peptides were also determined in the solid state by X-ray diffraction. The attempts for the selective and total removal of the groups protecting amino, carboxylic and phosphonate functions were in many cases unsuccessful due to the formation of cyclic structures and breakage of the phosphorus-to-carbon bond.


Subject(s)
Glycine/analogs & derivatives , Glycine/chemistry , Glycine/chemical synthesis , Peptides/chemical synthesis , Sarcosine/chemistry , Magnetic Resonance Spectroscopy , Models, Chemical , Models, Molecular , Peptide Biosynthesis , Peptides/chemistry , Protein Conformation , X-Ray Diffraction , Glyphosate
11.
Acta Crystallogr B ; 57(Pt 3): 346-52, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11373393

ABSTRACT

The crystal structure of m-nitroaniline has been examined at several temperatures over the 90-350 K range. Thermal evolution of the lattice parameters reveals a weak anomaly at 110 K and an important one at 300 K. The thermal expansion coefficients have been calculated at several temperatures and the principal axes cross-sections of the tensor were drawn. The lattice contraction along the b axis direction has been observed. The rigid-body analysis including an attached rigid group has provided the values of the translation and libration tensors at temperatures studied. The results indicate that m-nitroaniline undergoes a glass transition around 130 K arising from freezing molecular librations and translations. From above 340 K the growing plasticity of the m-nitroaniline crystal results in the loss of X-ray diffraction reflections. This is probably a second-order phase transition. It is coupled with a considerable increase in the nitro group torsion amplitude, but the NH.O hydrogen bonds are preserved. Analysis of the temperature evolution of short intermolecular distances enabled us to consider the occurrence of reorienting aggregates of hydrogen-bonded molecules in the high-temperature plastic phase.

12.
Acta Neurobiol Exp (Wars) ; 61(1): 1-12, 2001.
Article in English | MEDLINE | ID: mdl-11315316

ABSTRACT

In the present study the influx of 86Rb+, a K+ analogue, was studied in mitochondria, microsomes and chromaffin granules prepared from adrenal gland medulla. The most active electrogenic 86Rb+ transport was found in the membrane fraction identified as chromaffin granules by marker enzyme estimation. The transport was found to be sensitive to ATP, ATP gamma S, ADP and to the triazine dyes, but not to AMP and cAMP. The inhibition induced by ATP was observed in the absence of externally added Mg2+, suggesting that a free nucleotide, rather than the ATP-Mg complex, was required for inhibition. Furthermore, the 86Rb+ influx was found to be inhibited by Mg2+ alone, but not by Ca2+ and antidiabetic sulfonylureas. The 86Rb+ influx was not stimulated by potassium channel openers. In conclusion, our results indicate that an electrogenic, ATP-sensitive potassium transport system operates in the chromaffin granule membrane.


Subject(s)
Adenosine Triphosphate/physiology , Adrenal Glands/metabolism , Chromaffin Granules/metabolism , Potassium/metabolism , Animals , Biological Transport, Active/drug effects , Biological Transport, Active/physiology , Cattle , Chromaffin Granules/drug effects , Hypoglycemic Agents/pharmacology , In Vitro Techniques , Magnesium/pharmacology
13.
Article in English | MEDLINE | ID: mdl-11977325

ABSTRACT

BD-1158 is a new 1,4 benzodiazepine derivative. The purpose of the present experiments was to test the spontaneous behaviour (typical of a rabbit) after administration of BD-1158 and thus to define the activity and side effects of this substance under physiological conditions. The experiments were performed for 3 subsequent days in a group of 10 rabbits. On the first day spontaneous behaviour was tested. On the second day 1 ml of 1% starch solution was administered intraperitoneally. On the third day BD-1158 was administered intraperitoneally at a dose 10 mg/kg diluted in 1% starch solution up to 1 ml, 35-40 minutes before the beginning of the experiment. Six phases of behaviour were estimated. It was concluded that BD-1158 has a strong anxiolytic and sedative effect, decreases the state of animal's attention, water and food uptake.


Subject(s)
Anti-Anxiety Agents/pharmacology , Behavior, Animal/drug effects , Benzodiazepines/pharmacology , Animals , Drinking/drug effects , Eating/drug effects , Male , Orientation/drug effects , Rabbits
15.
Biochem Biophys Res Commun ; 262(1): 255-8, 1999 Aug 19.
Article in English | MEDLINE | ID: mdl-10448101

ABSTRACT

The purpose of this study was to investigate the effects exerted by thiol-modifying reagents on themitochondrial sulfonylurea receptor. The thiol-oxidizing agents (timerosal and 5, 5'-dithio-bis(2-nitrobenzoic acid)) were found to produce a large inhibition (70% to 80%) of specific binding of [(3)H]glibenclamide to the beef heart mitochondrial membrane. Similar effects were observed with membrane permeable (N-ethylmaleimide) and non-permeable (mersalyl) thiol modifying agents. Glibenclamide binding was also decreased by oxidizing agents (hydrogen peroxide) but not by reducing agents (reduced gluthatione, dithiothreitol and the 2,3-dihydroxy-1,4-dithiolbutane). The results suggest that intact thiol groups, facing the mitochondrial matrix, are essential for glibenclamide binding to the mitochondrial sulfonylurea receptor.


Subject(s)
ATP-Binding Cassette Transporters , Mitochondria, Heart/drug effects , Potassium Channels, Inwardly Rectifying , Potassium Channels/metabolism , Receptors, Drug/metabolism , Sulfhydryl Reagents/pharmacology , Adenosine Diphosphate/pharmacology , Adenosine Triphosphate/pharmacology , Animals , Binding Sites/drug effects , Cattle , Dithionitrobenzoic Acid/pharmacology , Dose-Response Relationship, Drug , Ethylmaleimide/metabolism , Ethylmaleimide/pharmacology , Glyburide/metabolism , Hydrogen Peroxide/pharmacology , Intracellular Membranes/drug effects , Intracellular Membranes/metabolism , Kinetics , Mersalyl/pharmacology , Mitochondria, Heart/metabolism , Oxidants/pharmacology , Permeability , Reducing Agents/pharmacology , Sulfhydryl Compounds/metabolism , Sulfonylurea Receptors
16.
Arch Physiol Biochem ; 107(2): 113-22, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10650343

ABSTRACT

Excitatory and inhibitory responses of sympathetic discharge were recorded in single renal postganglionic neurons of rabbits anaesthetized with urethane and chloralose. The animals were vagotomized and had transected aortic nerves. Responses were elicited by single volleys in the aortic C-fibres. Excitatory responses consisted in short-lasting increase in the rate of ongoing sympathetic discharge and were followed by inhibitory responses. Excitatory effects together with inhibitory responses were seen in 68% of units (19/28). Only excitatory effects appeared in 2 neurons (7.1%) and only inhibitory effects in 7 neurons (25%). In renal neurons exhibiting both effects, the excitatory responses appeared after latency of 172 +/- 8 ms (x +/- S.D.) and had duration of 64 +/- 11 ms. Inhibitory effects had latency o f 257 +/- 10 ms and their duration amounted to 265 +/- 22 ms. In more than half of recordings the excitatory responses were separated from the inhibitory effects by discharge lasting 33 +/- 4 ms. Significant correlations between latencies of excitatory and inhibitory responses and between duration of excitatory and latency of inhibitory responses suggest interaction between both effects. Increase in the number of afferent volleys (1 through 5) evoked relatively small changes in duration of the excitatory effect indicating that temporal facilitation is of minor importance in generating this response. Temporal facilitation was found to play an important role in determining duration of the inhibitory response. Comparison of effects of unilateral and bilateral stimulation of the aortic C-fibres showed larger occlusion of durations of the excitatory than inhibitory responses.


Subject(s)
Hemodynamics/physiology , Kidney/innervation , Nerve Fibers/physiology , Neurons, Afferent/physiology , Pressoreceptors/physiology , Sympathetic Fibers, Postganglionic/physiology , Action Potentials , Afferent Pathways/physiology , Animals , Electric Stimulation , Female , Male , Nerve Fibers, Myelinated/physiology , Rabbits , Reaction Time , Vagotomy
17.
Biochem Mol Biol Int ; 41(4): 679-86, 1997 Apr.
Article in English | MEDLINE | ID: mdl-9111929

ABSTRACT

The Ca(2+)-independent K+ selective channel in the membrane of adrenal gland chromaffin granules has earlier been identified. In the present report we describe new properties of this potassium channel using 86Rb+, a K+ analogue, flux measurements. The studies are performed in membrane vesicles prepared from chromaffin granules. The electrogenic 86Rb+ transport is inhibited by quinacrine, barium, zinc and magnesium. The effects of other potassium channel blockers on 86Rb+ transport into chromaffin granules are also reported.


Subject(s)
Adrenal Medulla/metabolism , Chlorides/metabolism , Chromaffin Granules/metabolism , Potassium Channel Blockers , Rubidium/metabolism , Animals , Biological Transport/drug effects , Cations, Divalent/pharmacology , Cattle , Cytochrome b Group/analysis , Microsomes/metabolism , Mitochondria/metabolism , Potassium/metabolism , Quinacrine/pharmacology
18.
Biochem Biophys Res Commun ; 230(3): 611-5, 1997 Jan 23.
Article in English | MEDLINE | ID: mdl-9015372

ABSTRACT

Biochemical identification of mitochondrial sulfonylurea receptors has been carried out through binding studies performed with [3H]glibenclamide. The presence of a single class of low affinity binding sites for glibenclamide in the inner mitochondrial membrane has been found, with a KD of 360 +/- 48 nM and BMAX of 48 +/- 7 pmoles/mg in beef heart mitochondria. Glibenclamide binding was affected by other sulfonylureas (glipizide, glisoxepide) but not by potassium channel openers (diazoxide, pinacidil, RP66471). In both rat liver and beef heart mitochondria adenine nucleotides (ATP, ADP, AMP) and nucleotide analogs (triazine dyes) produced large inhibition (from 60 to 80%) of [3H]glibenclamide binding. Photoaffinity labeling of submitochondrial particles with [125I]-glibenclamide revealed a single specifically labeled polypeptide band of 28 kDa by SDS-PAGE that is postulated to be (or to form a part of) the mitochondrial sulfonylurea receptor.


Subject(s)
ATP-Binding Cassette Transporters , Mitochondria, Liver/chemistry , Mitochondria, Liver/metabolism , Potassium Channels, Inwardly Rectifying , Potassium Channels/isolation & purification , Receptors, Drug/isolation & purification , Sulfonylurea Compounds/metabolism , Adenosine Triphosphate/pharmacology , Animals , Cattle , Glyburide/metabolism , Glyburide/pharmacology , Intracellular Membranes/metabolism , Male , Mitochondria, Heart/metabolism , Mitochondria, Liver/drug effects , Potassium Channels/chemistry , Potassium Channels/drug effects , Rats , Rats, Wistar , Receptors, Drug/chemistry , Receptors, Drug/drug effects , Sulfonylurea Receptors
19.
Arch Physiol Biochem ; 105(5): 456-66, 1997 Sep.
Article in English | MEDLINE | ID: mdl-9439783

ABSTRACT

Ongoing discharge in single renal sympathetic neurons was first studied in vagotomized rabbits without baroreceptor information (60 min after section of the aortic nerves). Under urethane + chloralose anaesthesia interspike-interval histograms were compiled and discharge rates were measured in 79 neurons. The following parameters were analysed: (a) the shortest, (b) the preferred and (c) the longest interspike-intervals, (d) discharge rate, (e) spread of a histogram, (f) coefficient of symmetry, and (g) coefficient of variability. The type of distribution of histograms and 9 correlations between some parameters were also assessed. These parameters were considered to make up the pattern of the ongoing discharge. The shortest, preferred and longest interspike-intervals of the ongoing discharge were: 14.1 +/- 0.9, 30.4 +/- 3.5 and 1672 +/- 82 ms. The mean rate of discharge amounted to 1.78 +/- 0.08 spikes/s. Three out of 9 correlation coefficients between the above parameters were statistically significant. In a second part, the effect of section of the aortic nerves and of 4-aminopyridine (a drug known to enhance synaptic transmission) on the pattern of ongoing discharge were also studied. Ten minutes after section of the aortic nerves the rate of discharge significantly increased, the shortest interspike-interval diminished and coefficient of variability was not changed. The number of significant correlations rose from 3 to 9.4-Aminopyridine significantly increased the discharge rate, did not alter the shortest interspike-interval and increased the coefficient of variability. These data show that assessing several parameters of ongoing discharge making up its pattern may differentiate between the excitatory effects of section of the aortic nerves and administration of 4-aminopyridine and in this way help to elucidate the mechanisms of action of various factors affecting renal sympathetic discharge.


Subject(s)
Neurons/physiology , Renal Artery/innervation , Sympathetic Nervous System/physiology , 4-Aminopyridine/pharmacology , Action Potentials/physiology , Animals , Aorta/innervation , Denervation , Female , Male , Pressoreceptors/physiology , Rabbits , Sympathetic Nervous System/cytology , Vagus Nerve/physiology
20.
Int J Biochem Cell Biol ; 28(8): 863-71, 1996 Aug.
Article in English | MEDLINE | ID: mdl-8811835

ABSTRACT

Magnesium depletion induces K+ and Na+ uniports in rat liver mitochondria. The purpose of the present study was to investigate the effects exerted by the antidiabetic sulfonylurea, glibenclamide, a well known blocker of ATP-sensitive potassium channels, on mitochondrial K+ and Na+ uniports. The K+ and Na+ uniport activities were monitored indirectly, in energized mitochondria, by following K+ and Na+ influxes as measured by light scattering. The membrane potential of the mitochondria was determined using a TPP+ selective electrode. Equilibrium binding measurements of glibenclamide to the inner mitochondrial membrane was performed with [3H]glibenclamide. Mitochondrial K+ and Na+ uniports were found to be inhibited by glibenclamide in a concentration-dependent manner, with IC50 of 20 +/- 7 and 15 +/- 8 microM, respectively. On lowering of the pH value, the potency of glibenclamide to inhibit the uniports activity was increased. Binding studies revealed the presence of a single class of low affinity binding sites for glibenclamide in the inner mitochondrial membrane, with a Kd of 4 +/- 2 microM and a BMAX of 148 +/- 50 pmoles/mg of protein. The present study provides evidence that both mitochondrial K+ and Na+ uniport activities are sensitive to the antidiabetic sulfonylurea, glibenclamide.


Subject(s)
Glyburide/pharmacology , Hypoglycemic Agents/pharmacology , Magnesium/metabolism , Mitochondria, Liver/metabolism , Potassium/metabolism , Sodium/metabolism , Animals , Dose-Response Relationship, Drug , Hydrogen-Ion Concentration , Ion Transport/drug effects , Male , Rats , Rats, Wistar
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