Healthy Adult Volunteers (healthy + adult_volunteer)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Urinary concentrations and urine ex-vivo effect of mecillinam and sulphamethizole

CLINICAL MICROBIOLOGY AND INFECTION, Issue 1 2004
M. B. Kerrn
Abstract Healthy adult volunteers received 1 g of sulphamethizole orally (n = 10) and later 400 mg of pivmecillinam (274 mg of mecillinam) (n = 9). All urine was collected in defined periods over 24 h, and the drug concentrations in urine were determined. For sulphamethizole, the maximum urine concentration for seven subjects was reached in 0,3 h, and for the remaining three in 3,6 h. For mecillinam, eight of the nine subjects attained a maximum urine concentration in 0,3 h, after which the concentration declined rapidly for six subjects in 3,6 h. Strains of Escherichia coli with different MICs for sulphamethizole and mecillinam were exposed to collected urine for 2.5 h and 5 h. The results indicated that a sensitive E. coli population should be suppressed by sulphamethizole in urine for two-thirds of the time (with 1 g twice-daily) and by mecillinam in urine throughout the 24-h period (with 400 mg three times a day). There was a slight but significant correlation between the ex-vivo effect (, log10 CFU/mL) and the log10 concentration/MIC ratio after exposure to sulphamethizole for 5 h (r2 = 0.27, p < 0.0001), and a significant correlation between the variables with mecillinam (r2 = 0.66, p < 0.0001). [source]


Ventricular Asynchrony of Time-to-Peak Systolic Velocity in Structurally Normal Heart by Tissue Doppler Imaging

ECHOCARDIOGRAPHY, Issue 7 2010
Hakimeh Sadeghian M.D.
Background: Echocardiographic measurements of time-to-peak systolic velocities (Ts) are helpful for assessing the degree of cardiac asynchrony. We assessed the degree of ventricular asynchrony in structurally normal heart according to Ts by tissue Doppler imaging. Methods: We performed conventional echocardiography and tissue velocity imaging for 65 healthy adult volunteers to measure the Ts of 12 left ventricular segments in the mid and basal levels delay of Ts and standard deviation (SD) of Ts in all and basal segments. Six frequently used markers of dyssynchrony were measured and were also compared between men and women. Data are presented as median (25th and 75th percentile). Results: Septal-lateral and anteroseptal-posterior delays were 50 (20, 90) and 20 (0, 55) ms. The delay between the longest and the shortest Ts in basal and all segments were 100 (80, 120) and 110 (83, 128) ms, respectively. SD of Ts was 39 (24, 52) ms for basal and 41 (28, 51) ms for all segments. Overall, 76.9% of cases had at least one marker of dyssynchrony. Frequencies of dyssynchrony markers were almost significantly higher in women compared to men. The most frequently observed dyssynchrony marker was SD of Ts of all segments (70.8%) and the lowest was anteroseptal-posterior delay (21.5%). Conclusions: Normal population almost had dyssynchrony by previously described markers and many of these markers were more frequent in women. Conducting more studies on normal population by other tissue Doppler modalities may give better description of cardiac synchronicity. (Echocardiography 2010;27:823-830) [source]


Left Ventricular Apical Thin Point Viewed with Two-Dimensional Echocardiography

ECHOCARDIOGRAPHY, Issue 8 2009
Guo Baosheng M.D.
The aim of this study was to evaluate the usefulness of two-dimensional echocardiography in observing the left ventricular apical thin point (LVATP) and to view the change in thickness and width of the LVATP during the cardiac cycle. Transthoracic echocardiography was performed in 32 healthy adult volunteers to observe the LVATP in an apical three-chamber view. The width and thickness of the LVATP were measured at the end-diastole as well as at the end-systole. With two-dimensional echocardiography, the LVATP could be clearly shown. The width of the LVATP at the end-diastole and end-systole was 3.3 mm ± 1.4 mm versus 0.9 mm±0.4 mm, P < 0.001; the thickness of the LVATP at the end-diastole and end-systole was 1.7 mm ± 0.6 mm versus 1.8 mm ± 0.8 mm, P > 0.05. The LVATP can be viewed with two-dimensional echocardiography; the LVATP changes significantly in width during the cardiac cycle, whereas the thickness of the LVATP changes insignificantly. [source]


Age-related plasma reference ranges for two heparin-binding proteins , vitronectin and platelet factor 4

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 6 2009
F. NEWALL
Summary This study was conducted to establish age-related reference ranges for two heparin-binding proteins , vitronectin and platelet factor 4 (PF4) , and to determine if the quantitative values of these proteins may contribute to the reported age-dependent effect of unfractionated heparin (UFH). Plasma samples were obtained from healthy children aged between 1 month and 16 years and from healthy adult volunteers. Two commercial kits were used to measure plasma vitronectin and PF4 levels. Results were reported as mean and boundaries including 95% of the population. Plasma vitronectin levels for children aged 1,5 years were significantly higher compared with adults. Plasma PF4 levels for infants <1 year of age were significantly lower compared with adults. The differences between reference values for both proteins in all other age-groups were not statistically significant. This study for the first time has established age-related reference ranges for vitronectin and PF4. In establishing these ranges, the quantitative values of these proteins do not appear to be the major contributory cause for the age-dependent variation in UFH effect. Future studies are required to evaluate the possible impact of age-dependent differences in binding between heparin-binding proteins and UFH. [source]


Sonographic examination of the oral phase of swallowing: Bolus image enhancement

JOURNAL OF CLINICAL ULTRASOUND, Issue 2 2002
Michael J. Casas DDS
Abstract Purpose The purpose of this study was to evaluate the ability of 4 liquid boluses to enhance pixel brightness and the ease with which the boluses could be identified during the sonographic evaluation of oral swallowing in healthy young adults. Methods Ten healthy adult volunteers (5 men and 5 women), ranging in age from 21 to 31 years, underwent sonographic evaluation of the oral phase of swallowing while sitting in their usual feeding position. We compared the ability of the 4 following liquids to improve sonographic visualization of swallowing with that of water: a carbonated cola beverage, 5.0 ml of Thick-It in 120 ml of water, 2.5 ml of Thick-It in 120 ml of water, and 7.5 ml of confectioners' sugar in 120 ml of water. Water was used as a control. In each case, 5 ml of the liquid was introduced into the subject's oral cavity using a syringe, and the subject was instructed to swallow. Digitized still images and recorded video sequences of sonographic examinations of the swallowing were analyzed. The brightness of the bolus image on selected digitized video frames was measured digitally using Image Analyst software. Pixel brightness within selected regions of interest for each of the test liquids was statistically compared with that for water. Seven clinicians rated the visualization of each test liquid and water on paired sonographic videotape sequences. These ratings and the level of agreement between them were statistically tested. Results Only the carbonated cola beverage demonstrated statistically greater pixel brightness than that of water on digitized video frames (p = 0.01), whereas both cola (with a moderate inter-rater agreement, , = 0.50) and 5.0 ml Thick-It mixed with 120 ml of water (with a fair inter-rater agreement, , = 0.24) were significantly better visualized on sonographic video sequences. Conclusions The digital still-frame analysis confirmed the clinicians' ratings of bolus visualization on real-time sonography, but dynamic sonography is more important than still frames in assessing sonographic swallow media because the dynamic images more closely parallel what is seen in clinical practice. Future investigations of sonographic contrast agents for use in the examination of the oral phase of swallowing should use both static digital (still-frame) and dynamic (real-time) assessment methods, as well as expert reviewers. © 2002 John Wiley & Sons, Inc. J Clin Ultrasound 30:83,87, 2002; DOI 10.1002/jcu.10034 [source]


Safety characteristics of gadobenate dimeglumine: Clinical experience from intra- and interindividual comparison studies with gadopentetate dimeglumine

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 6 2006
Frank G. Shellock PhD
Abstract Purpose To evaluate the safety and tolerability of gadobenate dimeglumine (Gd-BOPTA) relative to that of gadopentetate dimeglumine (Gd-DTPA) in patients and volunteers undergoing MRI for various clinical conditions. Materials and Methods A total of 924 subjects were enrolled in 10 clinical trials in which Gd-BOPTA was compared with Gd-DTPA. Of these subjects, 893 were patients with known or suspected disease and 31 were healthy adult volunteers. Of the 893 patients, 174 were pediatric subjects (aged two days to 17 years) referred for MRI of the brain or spine. Safety evaluations included monitoring vital signs, laboratory values, and adverse events (AE). Results The rate of AE in adults was similar between the two agents (Gd-BOPTA: 51/561, 9.1%; Gd-DTPA: 33/472, 7.0%; P = 0.22). In parallel-group studies in which subjects were randomized to either agent, the rate of AE was 10.9% for Gd-BOPTA and 7.9% for Gd-DTPA (P = 0.21). In the subset of subjects receiving both agents in intraindividual crossover trials, the rate of AE was 8.0% for Gd-BOPTA and 8.5% for Gd-DTPA (P = 0.84). Results of other safety assessments (laboratory tests, vital signs) were similar for the two agents. Conclusion The safety profile of Gd-BOPTA is similar to Gd-DTPA in patients and volunteers. Both compounds are equally well-tolerated in patients with various disease states undergoing MRI. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [source]


A simple method to reduce the inspiratory oxygen fraction for high pulmonary blood flow patients in an operating room

PEDIATRIC ANESTHESIA, Issue 12 2007
AYAKO ASAKURA MD
Summary Background:, Low inspired oxygen acutely increases pulmonary vascular resistance and decreases pulmonary-systemic blood flow ratio. We present a simple method to lower inspired oxygen fraction (FIO2 < 0.21) without supplemental nitrogen, during mechanical ventilation by an anesthesia machine. Methods:, After institutional approval, seven healthy adult volunteers and three infants (0,12 month old) scheduled for congenital heart surgery were enrolled in this study. All the infants were diagnosed with congestive heart failure because of high pulmonary blood flow and were thought to benefit from low FIO2. The volunteers performed spontaneous ventilation (fresh air flow rate = 10 l·min,1, tidal volume = 600 ml, frequency = 10 br·min,1). The infants were mechanically ventilated with air (fresh air flow rate = 6 l·min,1, tidal volume = 10 ml·kg,1, 15 < frequency < 30 br·min,1 to adjust PaCO2 between 5.8 kPa and 6.5 kPa (45,50 mmHg), after induction of general anesthesia and tracheal intubation. The fresh gas flow rates were determined by the following formula. Fresh gas flow rate = (FIO2 , FEO2) EVE/(0.21 + FIO2 , FEO2 , target FIO2). We recorded FIO2 every 5 min for 30 min. When arterial oxygen saturation decreased >15%, fresh gas flow rates were increased to adjust FIO2 to 0.21. Results:, In all of the seven volunteers and three infants target FIO2 was achieved in <10 min. FIO2 was kept at 0.18 ± 0.01 (SD) by calculated fresh air flow rates. In one infant, SpO2 decreased >15% 20 min after lowering FIO2, we had to discontinue this study, and increase fresh gas flow to ventilate the infant with FIO2 0.21. In the other two infants, FIO2 was maintained throughout the study. Conclusions:, This simple and convenient method to decrease FIO2, has a utility in clinical situations, in which pulmonary vascular resistance is to be increased to improve systemic oxygen delivery in patients with high pulmonary blood flow during cardiac surgery. [source]


Radiographic Comparison of Three Methods for Nasal Saline Irrigation,

THE LARYNGOSCOPE, Issue 8 2002
David E. L. Olson MD
Abstract Objective To compare intranasal distribution of saline solution delivered by three popular methods for nasal saline irrigation. Study Design Prospective, controlled comparison. Methods Eight healthy adult volunteers received nasal irrigation with 40 mL of isotonic, nonionic contrast material immediately before having coronal computed tomography to visualize distribution of solution in the paranasal sinuses. For each study subject, three methods of irrigation were used: irrigation using positive-pressure irrigation, irrigation using negative-pressure irrigation, and irrigation using a nebulizer. For each subject, three-dimensional computer reconstructions of the irrigated paranasal sinus airspaces were used to compare contrast solution volume and distribution achieved by the three methods. Results Of the three methods used, two methods, positive-pressure and negative-pressure irrigation, distributed contrast solution widely to ethmoid and maxillary sinuses, but distribution of contrast solution was more uniform using positive-pressure irrigation than using negative-pressure irrigation. The nebulization method distributed contrast solution poorly and resulted in a significantly lower volume of retained contrast solution (P <.05). Conclusion Judged solely on the basis of solution distribution in the nasal sinuses, nasal irrigation is effective when either positive-pressure or negative-pressure irrigation is used but is ineffective when a nebulizer is used. [source]


Aspects of Left Ventricular Morphology Outperform Left Ventricular Mass for Prediction of QRS Duration

ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2010
Nina Hakacova M.D., Ph.D.
Background: The knowledge of the case-specific normal QRS duration in each individual is needed when determining the onset, severity and progression of the heart disease. However, large interindividual variability even of the normal QRS duration exists. The aims of the study were to develop a model for prediction of normal QRS complex duration and to test it on healthy individuals. Methods: The study population of healthy adult volunteers was divided into a sample for development of a prediction model (n = 63) and a testing sample (n = 30). Magnetic resonance imaging data were used to assess anatomical characteristics of the left ventricle: the angle between papillary muscles (PMA), the length of the left ventricle (LVL) and left ventricular mass (LVM). Twelve-lead electrocardiogram (ECG) was used for measurement of the QRS duration. Multiple linear regression analysis was used to develop a prediction model to estimate the QRS duration. The accuracy of the prediction model was assessed by comparing predicted with measured QRS duration in the test set. Results: The angle between PMA and the length of the LVL were statistically significant predictors of QRS duration. Correlation between QRS duration and PMA and LVL was r = 0.57, P = 0.0001 and r = 0.45, P = 0.0002, respectively. The final model for prediction of the QRS was: QRSPredicted= 97 + (0.35 × LVL) , (0.45 × PMA). The predicted and real QRS duration differed with median 1 ms. Conclusions: The model for prediction of QRS duration opens the ability to predict case-specific normal QRS duration. This knowledge can have clinical importance, when determining the normality on case-specific basis. Ann Noninvasive Electrocardiol 2010;15(2):124,129 [source]


Pharmacokinetics and tolerability of intranasal diazepam and midazolam in healthy adult volunteers

ACTA NEUROLOGICA SCANDINAVICA, Issue 5 2009
V. D. Ivaturi
Objective,,, The purpose of this pilot study was to determine the pharmacokinetics and tolerability of an investigational diazepam (DZP) formulation and a parenteral midazolam (MDZ) formulation following intranasal (i.n.) administration for the efficient treatment of seizure emergencies. Methods,,, Each subject received 5 mg of DZP and MDZ via both i.n. and intravenous routes in a four-way, randomized crossover trial. Blood samples were collected over 48 h. DZP and MDZ concentrations were measured using HPLC. Using analog scales, subjects rated tolerability (0 = no change from normal; 10 = maximum intolerability) and pain (0 = no pain; 4 = extreme pain) prior to and 0, 5, 15, 60 min, and 8 h after administration. Results,,, The Cmax and Tmax values for i.n. DZP and MDZ were 179.2 ng/ml and 28.8 min vs 62.8 ng/ml and 21.6 min, respectively. Immediately following i.n. administration, subjects reported tolerability scores of 6.75 and 6.0, and identical pain scores, 3.2, for DZP and MDZ, respectively. Conclusion,,, Both formulations were rapidly absorbed following i.n. administration with transient discomfort. DZP had a longer half-life, which may result in an extended duration of action. Further studies in large patient populations to evaluate the safety after long term use, efficacy and pharmacokinetics of i.n. DZP are warranted. [source]


Abnormal dose-response melatonin suppression by light in bipolar type I patients compared with healthy adult subjects

ACTA NEUROPSYCHIATRICA, Issue 5 2009
Karen T. Hallam
Objective: Among potential endophenotypes proposed for bipolar affective disorder focusing on circadian abnormalities associated with the illness has particularly high face validity. Melatonin sensitivity to light is one circadian endophenotype proposed as useful in bipolar disorder. The aim of this study was to investigate melatonin sensitivity to light over a range of light intensities in order to compare and contrast responses in bipolar I patients with those of healthy adult volunteers. Methods: The study included seven patients (4 females, 3 males) with bipolar I disorder and 34 control participants (22 females, 12 males) with no personal or family history of affective illness. Melatonin sensitivity to light was determined in all patients and participants across a range of light intensities (0, 200, 500 and 1000 lux). Results: The results indicated that patients showed melatonin super-sensitivity to light in comparison with controls, a response that was consistent across the entire light intensity range investigated. Conclusion: The study provides further evidence for a super sensitive response in bipolar I patients and suggests that its potential usefulness as an endophenotypic marker of the illness is deserving of further research. [source]


Using diffusion MRI for measuring the temperature of cerebrospinal fluid within the lateral ventricles

ACTA PAEDIATRICA, Issue 2 2010
LR Kozak
Abstract Aim:, Hypothermia is often induced to reduce brain injury in newborns, following perinatal hypoxic,ischaemic events, and in adults following traumatic brain injury, stroke or cardiac arrest. We aimed to devise a method, based on diffusion-weighted MRI, to measure non-invasively the temperature of the cerebrospinal fluid in the lateral ventricles. Methods:, The well-known temperature dependence of the water diffusion constant was used for the estimation of temperature. We carried out diffusion MRI measurements on a 3T Philips Achieva Scanner involving phantoms (filled with water or artificial cerebrospinal fluid while slowly cooling from 41 to 32°C) and healthy adult volunteers. Results:, The estimated temperature of water phantoms followed that measured using a mercury thermometer, but the estimates for artificial cerebrospinal fluid were 1.04°C lower. After correcting for this systematic difference, the estimated temperature within the lateral ventricles of volunteers was 39.9°C. Using diffusion directions less sensitive to cerebrospinal fluid flow, it was 37.7°C, which was in agreement with the literature. Conclusion:, Although further improvements are needed, measuring the temperature within the lateral ventricles using diffusion MRI is a viable method that may be useful for clinical applications. We introduced the method, identified sources of error and offered remedies for each. [source]