On the thermal effect induced in tissue samples exposed to extremely low-frequency electromagnetic field.

BACKGROUND: The influence of electromagnetic exposure on mammalian tissues was approached as a public health issue aiming to reveal the putative side effect of 50 Hz industrial and domestic supply source (i) during aliments storage near such sources; (ii) in people staying couple of hours in the proximity of conducting wires. MATERIALS AND METHODS: Fluorescence emission based thermal sensor was used to emphasize temperature dynamics of fresh meat samples during controlled electromagnetic exposure in Helmholtz coils adjusted to deliver 50 Hz / (4÷10) mT electromagnetic field in their inner volume. Fluoroptic temperature probe with 0.1 °C accuracy measurement and data acquisition software allowed reading temperature every second, in the tissue volume during exposure. RESULTS: The temperature dynamics curves of ex-vivo porcine tissues like liver, kidney, brain, muscle, lung, and bone, were comparatively analyzed - the choosing of the mammalian species being justified by metabolic and physiological similarities with human body. The curve slopes appear to be the same for the range of initial temperatures chosen to perform the tests (20.0 ± 0.1 °C), the temperature increase reaching around 2.0 °C for the magnetic flux density of 10 mT. Quantitative dependence was evidenced between the thermal effect and the magnetic flux density. CONCLUSIONS: The technical interpretation is based on heating effect, on bioimpedance increasing and on water vaporization during wet sample exposure. The biomedical aspects derive from the degrading effects of food heating as well as from possible in vivo effects of living body exposure.

Nonlinear analysis of saccade speed fluctuations during combined action and perception tasks.

BACKGROUND: Saccades are rapid eye movements used to gather information about a scene which requires both action and perception. These are usually studied separately, so that how perception influences action is not well understood. In a dual task, where the subject looks at a target and reports a decision, subtle changes in the saccades might be caused by action-perception interactions. Studying saccades might provide insight into how brain pathways for action and for perception interact. NEW METHOD: We applied two complementary methods, multifractal detrended fluctuation analysis and Lempel-Ziv complexity index to eye peak speed recorded in two experiments, a pure action task and a combined action-perception task. RESULTS: Multifractality strength is significantly different in the two experiments, showing smaller values for dual decision task saccades compared to simple-task saccades. The normalized Lempel-Ziv complexity index behaves similarly i.e. is significantly smaller in the decision saccade task than in the simple task. COMPARISON WITH EXISTING METHODS: Compared to the usual statistical and linear approaches, these analyses emphasize the character of the dynamics involved in the fluctuations and offer a sensitive tool for quantitative evaluation of the multifractal features and of the complexity measure in the saccades peak speeds when different brain circuits are involved. CONCLUSION: Our results prove that the peak speed fluctuations have multifractal characteristics with lower magnitude for the multifractality strength and for the complexity index when two neural pathways are simultaneously activated, demonstrating the nonlinear interaction in the brain pathways for action and perception.

DYNAMICAL COMPLEXITY ANALYSIS OF SACCADIC EYE MOVEMENTS IN TWO DIFFERENT PSYCHOLOGICAL CONDITIONS.

Saccadic eye movements of a normal subject were assessed through semi-quantitative analysis algorithms based on linear and non-linear test application in order to highlight the dynamics type characterizing saccadic neural system behavior. These movements were recorded during a simple visually-guided saccade test and one with a cognitive load involving button pressing to show a decision. Following the application of specific computational tests, chaotic dynamical trend dominancy was mostly revealed with some differences between the two saccade recording conditions: auto-correlation time was increased from 170 to 240 by cognitive task superposition and the Hurst exponent was enhanced from 0.52 to 0.76, denoting more persistence in the dynamics of saccadic system during increased neural activity related to cognitive task.

Erectile function, erection hardness and tolerability in men treated with sildenafil 100 mg vs. 50 mg for erectile dysfunction.

AIM: To compare efficacy and tolerability between 100-mg and 50-mg sildenafil doses in five double-blind, placebo-controlled (DBPC) fixed-dose studies. METHODS: Doses were compared for the change (baseline to end of 8-12 weeks of DBPC treatment) in score on the Erectile Function (EF) domain of the International Index of Erectile Function (IIEF; from five fixed-dose studies, > 1500 men); the per-patient estimated percentage of occasions that a specified Erection Hardness Score (EHS; from two of the five fixed-dose studies, > 500 men) was achieved, computed from logistic regression; the odds ratio (OR) of achieving EHS3 (hard enough for penetration, but not completely hard) and EHS4 (fully hard and completely rigid); and the adverse event incidence by treatment (from all five fixed-dose studies). RESULTS: For the 100-mg vs. 50-mg dose, IIEF-EF score improvement was consistently greater across the five studies and was statistically significant when data from two studies with similar design were pooled (10.7 ± 0.64 vs. 8.9 ± 0.83, p = 0.0287); and during the first 2 weeks of treatment, the odds of achieving EHS4 erections were almost doubled in one study (OR = 1.77, p = 0.0398). Sildenafil was generally well tolerated at either dose. CONCLUSION: Men with erectile dysfunction treated with 100-mg compared with 50-mg sildenafil may be more likely to achieve a greater improvement in erectile function and, within the first 2 weeks, completely hard and fully rigid erections, with little or no greater risk to tolerability.

Hardness, function, emotional well-being, satisfaction and the overall sexual experience in men using 100-mg fixed-dose or flexible-dose sildenafil citrate.

The prescribing information for sildenafil citrate (VIAGRA, Pfizer, New York, NY, USA) recommends flexible dosing (50 mg initially, adjusted to 100 or 25 mg based on effectiveness and tolerability) in most men with erectile dysfunction (ED). In many men, however, 100 mg may be the most appropriate initial dose because it would reduce the need for titration and could prevent discouragement and treatment abandonment should 50 mg be insufficient. Results of two previously published double-blind, placebo-controlled sildenafil trials of similar design except for a fixed-dose vs flexible-dose regimen were analyzed. Relative to the flexible-dose, approximately one-third more men were satisfied with an initial and fixed dose of 100 mg. In addition, tolerability was similar, and improvements from baseline in outcomes on validated, ED-specific, patient-reported questionnaires were either similar (erectile function and the percentage of completely hard and fully rigid erections) or greater (emotional well-being and the overall sexual experience). The similarity in outcomes is not surprising given that almost 90% of the men in the flexible-dose trial titrated to 100 mg after 2 weeks. These data suggest prescription of an initial dose of 100 mg for men with ED, except in those for whom it is inappropriate.

Sildenafil reduces bother associated with erectile dysfunction: pooled analysis of five randomized, double-blind trials.

Improvement in bother associated with erectile dysfunction (ED) is an important aspect of successful treatment of ED. Changes in erectile function and the bother associated with ED were assessed in this analysis of pooled data from five 12-week, multicenter, randomized, double-blind, placebo-controlled, flexible-dose studies of sildenafil. Men who received sildenafil (n=578, vs placebo, n=550) had significantly greater (least squares mean+/-s.e.) improvement in erectile function (EF) domain scores of the international index of erectile function (IIEF) (10.0+/-0.3 vs 1.0+/-0.3, P<0.0001) and in erection distress scale (EDS) total transformed score (18.8+/-0.8 vs 4.8+/-0.9, P<0.0001). Scores on individual questions of the EDS were 24-65% higher after treatment with sildenafil (vs 8-12%, for placebo). The change in EF domain score correlated positively with the change in total transformed EDS score (0.43, P<0.0001). Successful treatment of ED with sildenafil may reduce the bother associated with ED.

Correlations between increased erection hardness and improvements in emotional well-being and satisfaction outcomes in men treated with sildenafil citrate for erectile dysfunction.

To explore relationships between erection hardness and other outcomes in men with erectile dysfunction (ED). Pooled analyses were conducted on 27 randomized, double-blind, placebo-controlled trials and six open-label trials from the worldwide sildenafil database. Outcomes included erection hardness graded subjectively, hardness and sexual satisfaction questions from the International Index of Erectile Function, general and sexually-specific emotional well-being from the self-esteem and relationship questionnaire, and the erectile dysfunction inventory of treatment satisfaction. Hardness outcomes improved (with a possible dose-response relationship for the achievement of fully hard and rigid erections) and correlated positively with the other outcomes. Sildenafil 100 mg produced optimal erection hardness (fully hard and rigid erections) in a substantial proportion of men with ED. Because optimal erection hardness correlated positively with some emotional well-being and satisfaction outcomes, sildenafil 100 mg may be the most appropriate dosage for treatment of ED for most men.

Sexual function and satisfaction in heterosexual couples when men are administered sildenafil citrate (Viagra) for erectile dysfunction: a multicentre, randomised, double-blind, placebo-controlled trial.

OBJECTIVE: To investigate the effect of improvement in erectile dysfunction (ED) on sexual function and satisfaction measures in heterosexual couples in which the woman reports that sexual intercourse is unsatisfactory at least half of the time. DESIGN: Multicentre, double-blind, placebo-controlled study. SETTING: Outpatient medical clinics. POPULATION: Hundred and eighty men with ED and their female partners in whom sexual intercourse was satisfactory about half the time or less (score of < or =3 on the Female Partner of ED Subject Questionnaire question 3 [FePEDS Q3]). METHODS: Men were randomised to flexible-dose sildenafil (25, 50, and 100 mg) or placebo as needed for 12 weeks. MAIN OUTCOME MEASURES: Primary: FePEDS Q3 ('Over the past four weeks, when you had sexual intercourse, how often was it satisfactory for you?') scored as 0 (no sexual activity) and 1 (almost never or never) to 5 (almost always or always). Secondary, partners: Sexual Function Questionnaire, Female Sexual Function Index (FSFI), and ED Inventory of Treatment Satisfaction (EDITS) partner version (EDITS-Partner). Secondary, men: International Index of Erectile Function (IIEF), General Efficacy Questions, event log data, Self-Esteem And Relationship questionnaire, and EDITS. Secondary, partners and men: Dyadic Adjustment Scale. RESULTS: The intention-to-treat population included 85 sildenafil recipients (mean age 59 +/- 12 years) and 91 placebo recipients (mean age 57 +/- 11 years). Most partners (aged 20-79 years; mean, 54 years) were postmenopausal. Sildenafil compared with placebo couples had greater improvement in the primary outcome (FePEDS Q3 [P < 0.0001]) and in sexual function, intercourse success rates, and secondary sexual satisfaction measures (FSFI satisfaction domain [P < 0.0001] and IIEF satisfaction domains [P < 0.001]) and had higher treatment satisfaction (EDITS and EDITS-Partner; P < 0.0001). Several predictors of improvement were identified, and improvement in one member of the couple correlated positively with improvement in the other member. CONCLUSIONS: The interdependence of sexual function and sexual satisfaction measures between members of couples consisting of men with ED and sexually healthy women reporting infrequent satisfactory sexual intercourse underscores the importance of including partners in ED treatment discussions.

Citric-acid-coated magnetite nanoparticles for biological applications.

Water-based magnetic fluids, generally intended for biomedical applications, often have various coating molecules that make them stable and compatible with biological liquids. Magnetic fluids containing iron oxide particles have been prepared by a co-precipitation method, using citric acid as stabilizer. The magnetic particles of the magnetic fluids were obtained by chemical precipitation from ferric (FeCl(3)) and ferrous salts (FeSO(4) or FeCl(2)) in alkali medium (ammonia hydroxide). Citric acid was used to stabilize the magnetic-particle suspension. Physical tests were performed in order to determine various microstructural and rheological features. Transmission electron microscopy was the main investigation method for assessing the magnetic-particle size. The dimensional distribution of the magnetic-particle physical diameter was analyzed using the box-plot statistical method while infrared absorption spectra were used to study the colloidal particle structure. The magnetic-fluid density (picnometric method), viscosity (capillary method) and surface tension (stalagmometric method) were measured using standard methods.

Complexity analysis of electrocardiographic signals.

Two types of electrocardiographic data series were investigated using appropriate tests based on a selection of semi-quantitative analysis algorithms. Distribution histograms, power spectra, auto-correlation functions, state-space portraits, Lyapunov exponents and wavelet transformations were applied to electrocardiograms of normal and stressed subjects. Statistical analysis using the Student's t-test revealed significant and non-significant alterations in stress-loaded cases compared to normal ones. Higher levels of adrenaline may account for a more complex dynamics (deterministic chaos) revealed in the stressed subjects.

[Magnetic liquid influence upon some plant species of pharmaceutical interest]. / Influenta lichidelor magnetice asupra unor specii de plante de interes farmaceutic.

It was accomplished a study on the influence of a petroleum magnetic liquid upon two plant species of pharmaceutical interest: Papaver somniferum L. and Chelidonium majus L. Experimental observation aimed: callus accumulation, seed germination, mitotic index and fluorescence of the photosynthesis pigments. The plant samples were taken from in vitro cultures obtained from different explant types while the magnetic liquid was added in the culture media in low concentrations (ml/l). The germination test showed a positive influence of the magnetic liquid, the cell division test revealed an increased mitotic index, callus accumulation rate is enhanced while the fluorescence spectra showed maxima shift for the samples in comparison to the controls.

Prostate cancer education in African American churches.

The use of churches as recruitment sites of African Americans into health promotion activities is a popular theme in the 1990s literature. This research measured the impact of previous exposure to cancer on participation in an educational program and a free prostate cancer screening. Cues to action from the Health Belief Model provided the conceptual framework. Over 500 men attended a prostate cancer educational program at their church. Men who participated in the educational program and completed the questionnaire were given a voucher that they could take to their doctor of choice for a free prostate cancer examination. Having a member of the congregation who was previously diagnosed with cancer was a significant cue to attendance at the educational program (P = 0.03). Recommendations for future cancer screening in churches are given.

[The effect of light intensity and neostigmine on the electroretinogram of Drosophila melanogaster]. / Influenta intensitatii luminoase si a neostigminei asupra electroretinogramei la Drosophila melanogaster.

In this article is presented the influence upon the electroretinogram, of some external factors acting at different levels of the visual system in the fruit fly, Drosophila melanogaster. The experiments revealed the effects generated by the light intensity modification as well as by the injection of a neuropharmaceutic--the neostigmine. The increase of the light stimuli intensity induced the same change of the rate between the amplitudes of the main electroretinographic components as the neostigmine does. It was used the "flickering" excitation regime, utilizing a data acquisition system adapted to the principal experimental device.

[Cytogenetic changes induced by low-intensity microwaves in the species Triticum aestivum]. / Modificari citogenetice induse de microunde de mica intensitate la specia Triticum aestivum.

Seeds of Triticum aestivum having an uniform genophond have been exposed to a microwave flow, with a frequency of 9.75 GHz and a low intensity. The effects of microwaves at various doses on mitotic activity have been followed. Our results show that as compared to the controls different types of chromosomal aberrations appeared: delayed chromosomes, micronuclei, interchromosomal bridges, chromosomal fragments.

Selective interaction model and photoreceptor cell membrane.

A mathematical model is proposed in order to describe, from the thermodynamic point of view, the changes in the photoreceptorcell membrane induced by light stimuli. The phenomenologicalbackground is the increase of the fly microvillar membrane ionicconductivity as a consequence of Ca(++-)Na(+) affinity modification under light action. On the basis of the analogywith the model of protein interaction in mixed solvents, themodel is focused on the selective interaction between ionchannels gates and two ionic ligands. Three possible theoretical cases are examined.