ABSTRACT
BACKGROUND: Psychometric properties and initial normative information are provided for the sluggish cognitive tempo, attention-deficit/hyperactivity disorder-inattention, attention-deficit/hyperactivity disorder-hyperactivity/impulsivity, oppositional defiant disorder, callous-unemotional behavior (limited prosocial emotions specifier), anxiety, depression, social impairment, and academic impairment scales of the Spanish Child and Adolescent Behavior Inventory. METHOD: Mothers, fathers, and teachers of 2,142 third to sixth grade Spanish children (49.49% girls; ages 8-13) from randomly selected schools on the Balearic Islands completed the Child and Adolescent Behavior Inventory. RESULTS: Scores from the scales demonstrated reliability (internal consistency and inter-rater), structural validity, and convergent/discriminant validity with attention-deficit/hyperactivity disorder and learning disorder diagnoses for boys and girls separately for each source. Normative information (T-scores) is provided for the nine scales separately for boys and girls, with test information functions supporting use of the symptom scales for screening purposes. CONCLUSIONS: Although more comprehensive Spanish norms are still needed, the initial normative information on the scales should be useful to inform the clinical care of individual Spanish children, with the positive psychometric properties of the scores also supporting the use of the scale for research. Copies of the Spanish Child and Adolescent Behavior Inventory and norms are available for free to clinicians and researchers.
Subject(s)
Adolescent Behavior , Attention Deficit Disorder with Hyperactivity , Adolescent , Attention Deficit Disorder with Hyperactivity/diagnosis , Attention Deficit and Disruptive Behavior Disorders , Child , Female , Humans , Male , Parents , Psychometrics , Reproducibility of ResultsABSTRACT
Confirmatory factor analysis (CFA) was used to evaluate five different models for the organization of the DSM-IV ADHD and oppositional defiant disorder (ODD) symptoms (Model 1: a single factor model; Model 2: an ADHD and ODD two factor model; Model 3a: an inattention (INA), hyperactivity/impulsivity (HYP/IMP), and ODD three factor model; Model 3b: an INA, HYP/IMP, and ODD three factor model where the three IMP symptoms cross-load on the ODD factor; Model 4: an INA, HYP, IMP, and ODD four factor model). To evaluate these models, maternal ratings of ADHD and ODD symptoms were obtained at outpatient pediatric clinics on 742 children not in treatment and 91 children in treatment for ADHD. Model 3a resulted in a good fit as well as a significantly better fit than Model 2. Model 3a was also equivalent across treatment status, gender, and age groupings for the most part. Though Models 3b and 4 provided a statistically better fit than Model 3a, the improvement in fit was small and other model selection criteria argued against these more complex models.
Subject(s)
Attention Deficit Disorder with Hyperactivity/diagnosis , Attention Deficit and Disruptive Behavior Disorders/diagnosis , Attention Deficit Disorder with Hyperactivity/psychology , Attention Deficit and Disruptive Behavior Disorders/psychology , Child , Factor Analysis, Statistical , Female , Humans , Male , Psychological TheoryABSTRACT
Used the Eyberg Child Behavior Inventory (ECBI) to measure disruptive behavior problems in children and adolescents. A controversy exists, however, on the dimensional structure of the ECBI. To evaluate this issue, an exploratory factor analysis was first performed on a sample of 1,263 children and adolescents. This analysis identified 3 meaningful factors (i.e., Oppositional Defiant Behavior Toward Adults, Inattentive Behavior and Conduct Problem Behavior) and a fourth, poorly defined factor. A confirmatory factor analysis (CFA) evaluated the fit of the 3 meaningful factors in a second sample of 1,264 children and adolescents. The 3-factor model with 2 correlated errors provided a excellent fit. This 3-factor model also provided a significantly better fit than 2- and 1-factor models. Multiple group CFA indicated that the factor pattern, item-factor loadings, factor correlations, and correlated errors were equivalent across the samples. The CFA on sex yielded similar results. Initial normative information is presented for boys (n = 1,322) and girls (n = 1,205) within 4 age ranges (i.e., 2-5, 6-9, 10-13, 14-17) for the 3 factors. The use of these 3 factors, especially Oppositional Defiant Behavior and Conduct Problem Behavior, should make the ECBI more useful as a screening and outcome measure.
Subject(s)
Attention Deficit and Disruptive Behavior Disorders/diagnosis , Conduct Disorder/diagnosis , Parent-Child Relations , Adolescent , Attention , Attention Deficit and Disruptive Behavior Disorders/psychology , Child , Child, Preschool , Conduct Disorder/psychology , Diagnosis, Differential , Female , Humans , Male , Psychometrics , Sensitivity and SpecificityABSTRACT
Content validity requires a clear definition of the construct of interest and the delineation of the construct from similar constructs. Content validity also requires that the items be representative of the construct as well as specific to the construct. An examination of the items on the Psychopathy Screening Device (PSD), a parent- and teacher-rating scale of childhood psychopathy, indicates significant overlap with the symptoms and associated features of attention deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder (CD). The failure of the PSD to have unique items results in poor discriminant validity with ADHD, ODD, and CD rating scales. More careful attention to content validation guidelines is required to develop a more useful measure of childhood psychopathy.
Subject(s)
Antisocial Personality Disorder/diagnosis , Attention Deficit Disorder with Hyperactivity/diagnosis , Attention Deficit and Disruptive Behavior Disorders/diagnosis , Child Behavior Disorders/diagnosis , Mass Screening , Personality Assessment/statistics & numerical data , Antisocial Personality Disorder/classification , Antisocial Personality Disorder/psychology , Attention Deficit Disorder with Hyperactivity/classification , Attention Deficit Disorder with Hyperactivity/psychology , Attention Deficit and Disruptive Behavior Disorders/classification , Attention Deficit and Disruptive Behavior Disorders/psychology , Child , Child Behavior Disorders/classification , Child Behavior Disorders/psychology , Humans , Psychometrics , Reproducibility of ResultsABSTRACT
BACKGROUND: We are developing and testing a new ventricular assist device (VAD) to be powered by conditioned skeletal muscle. METHODS: To evaluate the VAD hardware and to develop a muscle training regimen, 8 calves have been used in studies in which the right latissimus dorsi muscle was employed. The experiments were carried out to an approximately 4-month duration. RESULTS: There was significant conversion of type II (fast twitch) to type I (slow twitch) muscle fibers. This did not correlate well, however, with device performance. The device stroke volumes ranged from approximately 17 to 90 cc. This variability of outcome occurred despite the fact that identical hardware, surgical procedures, and training regimens were employed. CONCLUSIONS: The results from the first eight studies lead us to speculate that perfusion may be important even when the muscle is working at pressures much lower than systemic blood pressure levels. In an attempt to augment tissue perfusion, we plan to investigate thermally induced angiogenesis as a possible mechanism for increasing blood flow to the tissue.
Subject(s)
Heart-Assist Devices , Muscle Contraction/physiology , Muscle, Skeletal/physiopathology , Animals , Cattle , Electric Stimulation , Equipment Design , Humans , Muscle, Skeletal/pathology , Stroke VolumeABSTRACT
The study presents data on the effectiveness of a parent-administered behavioral reading therapy program. Ten parents administered the therapy program to their second- to fourth-grade children with reading disability. All 10 children received 70 therapy sessions (30 minutes per session), with 5 of the 10 children receiving approximately 51 additional sessions, for a total of 121 sessions. Parents were able to administer the program effectively, and the children participated in an enthusiastic manner. Detailed records from the therapy sessions showed a high degree of mastery of the reading materials, and the children also showed significant and clinically meaningful improvements on standardized reading measures. Although the results must be viewed cautiously given the absence of a control group, the potential of the parent-administered reading therapy program for the remediation of reading disability seems good.
Subject(s)
Bibliotherapy , Learning Disabilities/therapy , Parents , Reading , Child , Female , Humans , MaleABSTRACT
Records of 2191 calvings from the Clemson University Beef Physiology Unit between 1981 and 1993 were analyzed to determine factors affecting malpresentation, mortality and dystocia. Only 20 (0.91%) parturitions involved malpresentation: posterior presentation (n = 14), leg deviations (n = 3), head deviations (n = 2) and breech birth (n = 1). Dystocia affected calf mortality within 24 h of birth (P < 0.05), with mortality increasing as the severity of dystocia increased. There was an overall 4.5% death loss within 24 h of birth, with 4 and 7% mortality rates for calves from multiparous and primiparous dams, respectively (P < 0.05). Mortality was higher for bull vs heifer calves (P < 0.05). Ninety-four percent of calvings were unassisted, while 6% were assisted births. Dystocia was greater (P < 0.01) in primiparous (17%) than in multiparous dams (4%). In births involving dystocia, 28.1% required mild traction, 69.3% required heavy traction and 2.6% required Cesarean section. Birth weights associated with normal births and mild traction (36 and 36 kg) were lighter than those associated with heavy traction and Cesarean section (40 and 42 kg, respectively; P < 0.05). In conclusion, malpresentations were too few to be of significance, and dystocia influenced mortality within 24 h of birth. Calf birth weight and parity of dam explained most of the observed variations in dystocia.
Subject(s)
Breech Presentation , Cattle Diseases/mortality , Dystocia/veterinary , Age Factors , Animals , Birth Weight , Cattle , Cesarean Section/veterinary , Dystocia/mortality , Female , Male , Parity , Pregnancy , Retrospective Studies , Risk Factors , Sex FactorsABSTRACT
We concurrently evaluated early weaning and once-daily suckling as options for shortening postpartum interval to estrus in primiparous cows calving in good body condition. Over 2 consecutive years, a total of 77 primiparous cows were assigned to 1 of 3 treatments: control (ad libitum suckling); once-daily suckling (for 30 d prior to start of breeding); or early weaning (calves weaned 30 d prior to start of breeding). All cows had a body condition score (BCS) of > or = 5 at parturition and were maintained in good condition throughout the breeding season. Cows were observed for estrus twice daily and blood samples for subsequent measurement of progesterone were collected at 48-h intervals. For data analysis, cows were divided into early- (> or = 85 d post partum) and late-calving (< 85 d post partum) groups at the onset of the breeding season. All calves were weighed at birth, at the onset of treatment, at weekly intervals until the start of the breeding season, and within 45 d of 205 d of age. Early weaning or once-daily suckling shortened the postpartum interval to first estrus of late-calving primiparous cows by 17 (P < 0.01) and 12 d (P < 0.08), respectively, compared with control group cows. However, among early-calving cows, neither early weaning nor once-daily suckling influenced the postpartum interval. Postpartum intervals of once-daily suckled cows and early-weaned cows were similar (P > 0.10).
Subject(s)
Cattle/physiology , Estrus , Parity , Postpartum Period/physiology , Sucking Behavior , Weaning , Animals , Female , Time FactorsABSTRACT
Uses a dimensional approach to evaluate the internal validity of the attention deficit hyperactivity disorder (ADHD) inattention (I) and hyperactivity/impulsivity (H/I), oppositional defiant disorder (ODD), and overt conduct disorder (CD) symptoms (i.e., whether a symptom has a stronger correlation with its own dimension than the other three dimensions). In Study 1, teachers rated 1,445 children on the DSM-III-R I, H/I, ODD, and overt CD symptoms. In Study 2, teachers rated 1,711 children on the DSM-IV I, H/I, ODD, and overt CD symptoms. All the I symptoms showed internal validity in both studies. In contrast, the H/I symptoms and the ODD symptoms, especially the H/I symptoms, showed weaker internal validity. All the overt CD symptoms showed internal validity except the DSM-IV bullies others symptom, with this symptom being more strongly related to the ODD dimension. Confirmatory factor analysis provided support for a 4-factor model consisting of I, H/I, ODD, and overt CD factors. Finally, the importance of internal validity for the construct validation of the disruptive behavior symptoms is discussed.
Subject(s)
Attention Deficit Disorder with Hyperactivity/diagnosis , Child Behavior Disorders/diagnosis , Cooperative Behavior , Personality Assessment/statistics & numerical data , Adolescent , Attention Deficit Disorder with Hyperactivity/classification , Attention Deficit Disorder with Hyperactivity/psychology , Child , Child Behavior Disorders/classification , Child Behavior Disorders/psychology , Child, Preschool , Female , Humans , Male , Psychiatric Status Rating Scales/statistics & numerical data , Psychometrics , Reproducibility of ResultsABSTRACT
A dimensional approach was used to evaluate the internal validity of the DSM-III-R ADHD-inattention, ADHD-hyperactivity/impulsivity, oppositional defiant disorder (ODD), and conduct disorder (CD) symptoms (i.e., whether a symptom has a stronger correlation with its own dimension that the other three). Parents rated 4,019 children between the ages of 2 and 19 on these symptoms. The results showed that 5 of the 6 inattention symptoms, 3 of the 4 hyperactivity symptoms, 1 of the 4 impulsivity symptoms, 6 of the 9 oppositional defiant disorder symptoms, and 8 of the 11 CD symptoms had significant internal validity. Confirmatory factor analysis (CFA) found support for inattention, hyperactivity/impulsivity, oppositional defiant, and conduct disorder dimensions. Multiple-group CFA also found support for factor pattern and loading invariance across gender. The implications of these results as well as the merits of the dimensional approach to symptom validity are discussed in the context of the DSM-IV changes in ADHD, ODD, and CD.
Subject(s)
Attention Deficit Disorder with Hyperactivity/classification , Conduct Disorder/classification , Adolescent , Attention Deficit Disorder with Hyperactivity/diagnosis , Child , Child, Preschool , Conduct Disorder/diagnosis , Female , Humans , Male , Parents/psychology , Predictive Value of Tests , Psychiatric Status Rating Scales/statistics & numerical data , Reproducibility of ResultsABSTRACT
Bacterial adhesion has been identified as the critical initial step in the pathogenesis of foreign body related infection. Recent investigations have shown microbial binding to implanted polymeric materials using specific adhesion of bacteria to immobilized plasma proteins, such as fibrin. These proteins are though to function as bridging molecules to facilitate bacterial colonization of the surface. The authors' results indicated a significant reduction in adhesion of biofilm forming Pseudomonas aeruginosa and coagulase negative Staphylococcus epidermidis to immobilized fibrin strands in the presence of platelet poor plasma (PPP) as compared to studies performed with phosphate buffered saline and Hank's balanced salt solution. A 10-fold decrease in the number of adherent bacteria was noted for samples exposed to PPP as compared to control samples. The effective range of PPP concentrations capable of producing the marked decrease in binding to fibrin strands was determined to be 1-100% for P. aeruginosa and 4-100% for S. epidermidis.
Subject(s)
Biofilms/growth & development , Pseudomonas aeruginosa/physiology , Staphylococcus epidermidis/physiology , Bacterial Adhesion , Biocompatible Materials , Culture Media , Fibrin , Humans , In Vitro Techniques , Materials Testing , Plasma , Prosthesis-Related Infections/etiology , Prosthesis-Related Infections/prevention & control , Surface PropertiesABSTRACT
This study was undertaken to investigate the possible association between thrombosis and infection using an in vitro test model in which fresh bovine blood was recirculated through test conduits (3.5 mm inner diameter) containing stent-like devices. Anticoagulation was adjusted so that the recirculating blood deposited thrombi on the stent to cause gradual occlusion, thus impeding the flow. Four stent-like devices were placed in separate conduits in each experiment, and blood was recirculated with the help of pneumatically driven ventricles. Flow through these conduits was monitored by ultrasonic flow detection. To quantitate bacterial interaction with thrombi, Staphylococcus epidermidis (15E10(9)) was labeled with 111Indium-oxine and added to the blood. Experiments lasted until the flow in the test conduits dropped to 10% of the starting flow. During this recirculation, as flow gradually decreased, one stent was taken out when flow was still at 100%, the second at 75%, the third at 50%, and the fourth at 10% of the starting flow. The number of bacteria associated with the thrombus was measured by gamma counting. The following observations were made: 1) the amount of thrombus increased with time in all experiments (this was confirmed in separate experiments by using autologous 111Indium labeled platelets); 2) bacterial adhesion showed a concomitant increase as thrombus size increased (this was confirmed by using 111Indium labeled bacteria), and 3) bacterial incorporation into the thrombus occurred regardless of whether they were viable or pretreated with the antibiotic rifampin. These observations suggest that as thrombi develop, they may preferentially attract micro-organisms. This suggests that devices with adherent thrombi may have greater susceptibility for infection.
Subject(s)
Bacterial Adhesion , Thrombosis/microbiology , Animals , Bacterial Infections/etiology , Cattle , Heart-Assist Devices/adverse effects , In Vitro Techniques , Indium Radioisotopes , Models, Biological , Staphylococcal Infections/etiology , Staphylococcus epidermidis/pathogenicity , Staphylococcus epidermidis/physiology , Stents/adverse effects , Thrombosis/complicationsABSTRACT
This paper examined stress processes in hypothetically psychosis-prone individuals. Subjects scoring high on Perceptual Aberration/Magical Ideation (Per-Mag subjects), Anhedonia, and low-scoring control subjects were compared for scores on Hassles and Uplifts, cognitive appraisal, coping strategies, emotions in two stressful situations, and on perceived social support. The groups differed in their experiences of minor life events and Secondary Appraisal but not in Primary Appraisal or emotions. There were notable differences in coping patterns and perceptions of social support. Per-Mag subjects contrasted with controls in using more coping by Escape-avoidance and Accepting responsibility, and reported less social support. Anhedonic subjects differed in their experience of minor life events and coped less through Positive reappraisal and Seeking social support. Per-Mag subjects are mainly distinguished by their coping processes. Anhedonic subjects are also sensitive to the incidence of minor life events. The results indicate that risk factors, stress, and coping interact in the absence of mental disorder.
Subject(s)
Adaptation, Psychological , Psychotic Disorders/psychology , Social Support , Stress, Psychological/complications , Adolescent , Adult , Defense Mechanisms , Disease Susceptibility/psychology , Female , Humans , Male , Personality Inventory/statistics & numerical data , Psychometrics , Psychotic Disorders/diagnosis , Risk FactorsABSTRACT
The Padua Inventory (PI), a self-report measure of obsessive and compulsive symptoms, is increasingly used in obsessive compulsive disorder (OCD) research. Freeston, Ladouceur, Rheaume, Letarte, Gagnon and Thibodeau (1994) [Behaviour Research and Therapy, 32, 29-36], however, recently showed that the PI measures worry in addition to obsessions. In an attempt to solve this measurement problem, this study used a content distinction between obsessions and worry to revise the PI. The revision was constructed to measure five content dimensions relevant to OCD i.e. (1) obsessional thoughts about harm to oneself or others; (2) obsessional impulses to harm oneself or others; (3) contamination obsessions and washing compulsions; (4) checking compulsions; and (5) dressing/grooming compulsions. A total of 5010 individuals participated in the study, 2970 individuals completing the PI and the Penn State Worry Questionnaire (PSWQ) and an additional 2040 individuals completing only the PI. The results provided support for the reliability and validity of the revision. In addition, the revision of the PI was more independent of worry, as measured by the PSWQ, than the original PI. Support was thus found for the validity of the content distinction between obsessions and worry. The importance of this content distinction is also discussed for the evaluation of other hypothesized distinctions between obsessions and worry.
Subject(s)
Obsessive-Compulsive Disorder/diagnosis , Obsessive-Compulsive Disorder/psychology , Personality Inventory , Adult , Compulsive Behavior/diagnosis , Compulsive Behavior/psychology , Female , Humans , Male , Middle Aged , Obsessive Behavior/diagnosis , Obsessive Behavior/psychology , Reproducibility of ResultsABSTRACT
Obsessive compulsive disorder (OCD) is increasingly studied in nonpatients, primarily through the selection of individuals who score high on a self-report measure of OCD. The usefulness of this methodology for understanding OCD presupposes that some of the individuals in the high-scoring group meet diagnostic criteria for OCD, that the obsessive-compulsive behaviors in the high-scoring individuals are stable across time to a certain degree, and that the features associated with OCD in patients also are found in the high-scoring nonpatients. Two studies are reported which provide support for these three assumptions. Together the studies suggest that OCD can be productively examined by the selection of individuals who score high on a self-report measure of OCD. Cautions in the use of this methodology for the study of OCD are also noted.
Subject(s)
Obsessive-Compulsive Disorder/diagnosis , Personality Inventory/statistics & numerical data , Adult , Female , Humans , Male , Obsessive-Compulsive Disorder/classification , Obsessive-Compulsive Disorder/psychology , Psychometrics , Reference Values , Reproducibility of ResultsABSTRACT
The relationship between indices of oxygen metabolism has been widely used in clinical practice to evaluate the adequacy of tissue perfusion, to predict the outcome of the critically ill patient, and to evaluate the effectiveness of therapies. This study quantitated and correlated the relationship between oxygen delivery (DO2), oxygen consumption (VO2), and oxygen extraction rate (EO2) in 14 animals with total artificial hearts (TAH) to investigate the oxygen metabolism in animals with TAH during different physiologic and pathologic conditions. These 14 animals were subdivided into healthy, critical, and exercise groups. There was a physiologic dependence of DO2 to VO2 in animals in the healthy and exercise groups, whereas a pathologic dependence of VO2 to DO2 appeared to occur in animals in the critical group. Reduced or inadequate VO2 leads to organ dysfunction, shock syndrome, multiple organ failure, and finally, mortality. Providing a higher level of DO2 by restoring circulating blood volume, increasing cardiac output, raising hematocrit levels, and improving pulmonary function to achieve a higher level of oxygen extract efficiency and oxygen consumption in animals with TAH that are in a critical condition might be helpful for the treatment of complications and result in decreasing mortality. Using the relationship between indices of oxygen metabolism as a physiologic modifier for TAH control algorithms also might improve the physiologic performance and quality of life of TAH recipients.
Subject(s)
Heart, Artificial , Oxygen/metabolism , Animals , Cardiac Output , Cattle , Critical Illness , Evaluation Studies as Topic , Hemodynamics , Homeostasis , Oxygen Consumption , Physical Exertion/physiologyABSTRACT
The production of blood microemboli (BME) was studied using an ex vivo exteriorized left ventricular assist device (LVAD) model in calves. Each of eight calves received a series of three LVADs, each operating for 24 hr. Blood microemboli were measured directly by a laser (624 nm and 828 nm) light scattering microemboli detection (LSMD) system through the LVAD outflow cannula and by constant pressure filtration (CPF) of blood samples from the LVAD outflow cannula. Hematologic parameters were also measured. After LVAD removal, perivalvular thrombi were evaluated using polar coordinate mapping. The average LSMD and CPF results correlated. For example, in one series of three calves, one ventricle exhibited significantly greater thrombogenesis than did the other ventricles, as indicated by both the LSMD and CPF results. In a series of five calves, one calf developed an abnormally high activated thromboplastin time (APTT), even in the absence of heparin. For two of the three ventricles tested in that calf, microemboli concentration (CPF), Factor XII activity, level of fibrin degradation products (FDP), and accumulated thrombus were significantly lower than for the other calves. The whole blood viscosity (WBV, at 230 s-1) in this calf also decreased to lower values than were seen with the other calves.
Subject(s)
Heart-Assist Devices/adverse effects , Thromboembolism/diagnosis , Thromboembolism/etiology , Animals , Biomarkers/blood , Biomedical Engineering , Blood Viscosity , Cattle , Evaluation Studies as Topic , Factor XII/metabolism , Fibrin Fibrinogen Degradation Products/metabolism , Filtration/methods , In Vitro Techniques , Light , Microspheres , Pressure , Scattering, Radiation , Thromboembolism/bloodABSTRACT
The anaerobic threshold represents an objective measure of functional capacity and is useful in assessment of pulmonary and cardiovascular dysfunction. This study determined the anaerobic threshold in total artificial heart animals and evaluated the performance of the total artificial heart system. Five animals with total artificial hearts were put under incremental exercise testing after exercise training. The intensity of exercise ranged from 2.0 to 4.5 km/hr, with an increment of 0.5 km/hr every 3 min. The anaerobic threshold was 6.72 +/- 0.84 ml/kg/min as detected by the lactate method, and 6.48 +/- 0.79 by the CO2 method. The value of the anaerobic threshold in total artificial heart animals implies that the performance capacity of a total artificial heart is not sufficient to meet the oxygen requirements of vigorously exercising skeletal muscle. The protocol does not allow for driving parameter changes during exercise, and this situation, combined with the manual mode of the control system used, was inadequate to allow the total artificial heart animals to exercise more vigorously. Using an automatic control mode might be helpful, as well as considering the relationship between indices of oxygen metabolism, such as oxygen delivery, oxygen consumption, and oxygen extraction rate, in the control algorithms in total artificial heart control systems.
Subject(s)
Anaerobic Threshold/physiology , Heart, Artificial , Animals , Blood Pressure/physiology , Carbon Dioxide/blood , Cardiac Output/physiology , Cattle , Evaluation Studies as Topic , Lactates/blood , Lactic Acid , Oxygen/blood , Oxygen Consumption/physiology , Physical Exertion/physiologyABSTRACT
Device related infection initiated by biofilm bacteria are often difficult to resolve with antimicrobial therapy. Study results indicate that application of static magnetic fields may enhance the activity of gentamicin against biofilm forming Pseudomonas aeruginosa adherent to a polymer substrate. Results indicate a maximal reduction of 86.5 +/- 7.2% (n = 6) in the number of adherent viable bacteria compared with a control for samples exposed to a 5 gauss (G) magnetic field and gentamicin. The effect appears to be limited to magnetic fields between 5 and 20 G. Experiments using glass, Chronoflex (Polymedica, Golden, CO), Biomer (Ethicon, Somerville, NJ), and polystyrene substrate showed that the effect was independent of substrate surface. Autoradiograms from In111 uptake experiments showed that bacteria colonizing the substrate surface were significantly reduced in samples subjected to a magnetic field and gentamicin.