Advancing Cardiovascular, Neurovascular, and Renal Magnetic Resonance Imaging in Small Rodents Using Cryogenic Radiofrequency Coil Technology

Research in pathologies of the brain, heart and kidney have gained immensely from the plethora of studies that have helped shape new methods in magnetic resonance (MR) for characterizing preclinical disease models. Methodical probing into preclinical animal models by MR is invaluable since it allows a careful interpretation and extrapolation of data derived from these models to human disease. In this review we will focus on the applications of cryogenic radiofrequency (RF) coils in small animal MR as a means of boosting image quality (e.g., by supporting MR microscopy) and making data acquisition more efficient (e.g., by reducing measuring time); both being important constituents for thorough investigational studies on animal models of disease. This review attempts to make the (bio)medical imaging, molecular medicine, and pharmaceutical communities aware of this productive ferment and its outstanding significance for anatomical and functional MR in small rodents. The goal is to inspire a more intense interdisciplinary collaboration across the fields to further advance and progress non-invasive MR methods that ultimately support thorough (patho)physiological characterization of animal disease models. In this review, current and potential future applications for the RF coil technology in cardiovascular, neurovascular, and renal disease will be discussed.

The physiological correlates of Kundalini Yoga meditation: a study of a yoga master

This study explores the physiological correlates of a highly practiced Kundalini Yoga meditator. Thoracic and abdominal breathing patterns, heart rate (HR), occipital parietal electroencephalograph (EEG), skin conductance level (SCL), and blood volume pulse (BVP) were monitored during prebaseline, meditation, and postbaseline periods. Visual analyses of the data showed a decrease in respiration rate during the meditation from a mean of 11 breaths/min for the pre- and 13 breaths/min for the postbaseline to a mean of 5 breaths/min during the meditation, with a predominance of abdominal/diaphragmatic breathing. There was also more alpha EEG activity during the meditation (M = 1.71 microV) compared to the pre- (M = .47 microV) and postbaseline (M = .78 microV) periods, and an increase in theta EEG activity immediately following the meditation (M = .62 microV) compared to the pre-baseline and meditative periods (each with M = .26 microV). These findings suggest that a shift in breathing patterns may contribute to the development of alpha EEG, and those patterns need to be investigated further.

Surface electromyography and mouse use position

This study examines muscle tension and subjective muscle tension awareness while using a computer mouse positioned to the right of a standard computer keyboard and a centrally positioned trackball. Seventeen volunteer subjects experienced in mouse and trackball use were seated at an ergonomically adjusted workstation. Surface electromyography (sEMG) and subjective muscle tension levels were recorded from four muscle groups (left sternocleidomastoid/scalene, right upper trapezius, right posterior deltoid, and right lower trapezius/rhomboids) during 1-min trials with subjects resting with hands in their lap, while using a trackball below the centre of the keyboard, and while using a mouse immediately to the right of a 101-key keyboard. All subjects showed significantly higher mean sEMG activity recorded from the right upper trapezius, right posterior deltoid, and right lower trapezius/rhomboids during mouse use to the right of a standard keyboard (arm abducted) compared to using a trackball positioned centrally, (p < 0.001). sEMG levels remained elevated during the entire trial period of right side mouse use without evidence of microbreaks (< 1 s epochs of low sEMG activity). sEMG activity from the left sternocleidomastoid/scalene muscles showed no significant change from baseline in any condition. Subjective reports of muscle tension did not correlate with sEMG activity. The authors predict that there will be an overall increase in reports of upper extremity musculoskeletal disorders (UEMSD) and computer related disorders (CRD) when people abduct their arms in order to reach a mouse positioned to the side of standard width, or wider keyboards. Discussed are the applications of sEMG for evaluation of computer keyboard and pointing device use, appropriate ergonomic equipment design, and a methodology for improving muscle awareness, strengthening, relaxation, and workstyle practices to promote healthier computing.

Respiratory sinus arrhythmia versus neck/trapezius EMG and incentive inspirometry biofeedback for asthma: a pilot study

This pilot study compared biofeedback to increase respiratory sinus arrhythmia (RSA) with EMG and incentive inspirometry biofeedback in asthmatic adults. A three-group design (Waiting List Control n = 5, RSA biofeedback n = 6, and EMG biofeedback n = 6) was used. Six sessions of training were given in each of the biofeedback groups. In each of three testing sessions, five min. of respiratory resistance and EKG were obtained before and after a 20-min biofeedback session. Additional five-min epochs of data were collected at the beginning and end of the biofeedback period (or, in the control group, self-relaxation). Decreases in respiratory impedance occurred only in the RSA biofeedback group. Traub-Hering-Mayer (THM) waves (.03-.12 Hz) in heart period increased significantly in amplitude during RSA biofeedback. Subjects did not report significantly more relaxation during EMG or RSA biofeedback than during the control condition. However, decreases in pulmonary impedance, across groups, were associated with increases in relaxation. The results are consistent with Vaschillo's theory that RSA biofeedback exercises homeostatic autonomic reflex mechanisms through increasing the amplitude of cardiac oscillations. However, deep breathing during RSA biofeedback is a possible alternate explanation.

Symptom prescription: inducing anxiety by 70% exhalation

This study investigates the effects of partial exhalation to feelings of anxiety. Thirty five volunteer subjects (14 male, 21 female, mean age 40.6) were first trained in slow diaphragmatic breathing (SDB). Then subjects rated their anxiety levels on a scale from 1 (none) to 5 (extreme) in sequential conditions of SDB, 70% subjective exhalation, and SDB. During the 70% subjective exhalation phase, subjects were instructed to breathe and limit their exhalation to 70% of the inhaled volume during each consecutive breath. The 70% subjective condition significantly (P < .0005) increased subjects' anxiety levels as compared to the initial SDB baseline, while a return to SDB significantly reduced the anxiety levels. The 70% approach appears useful in demonstrating to the client that possible changes in breathing patterns can affect anxiety.

The effects of therapist breathing style on subject's inhalation volumes

This study explored how the clinicians'/experimenters' breath patterns affected subjects' inhalation volume. 20 volunteer subjects inhaled 20 sequential breaths (10 normal and 10 paced) with their eyes closed. During the paced exhalation, the experimenter audibly exhaled in phase with the subjects' exhalation. The subjects's inhalation volumes significantly increased during the paced as compared to the initial normal breathing phase, F(1,19) = 8.82, p < .01, repeated measures ANOVA. These findings confirm that the clinician's breathing style directly affects the client's breath pattern.

Fifteen-month follow-up with asthmatics utilizing EMG/incentive inspirometer feedback

This study reports on the follow-up data of an integrated group program to reduce asthmatic symptoms. The 16 sessions included a comprehensive multibehavioral/desensitization retraining program and utilized EMG/Incentive inspirometer feedback to encourage slow diaphragmatic breathing in all situations. 17 out of 21 volunteers participated in the 15-month follow-up study. At the follow-up all subjects significantly reduced their EMG tension levels while simultaneously increasing their inhalation volumes. Subjects reported reductions in their asthma symptoms, medication use, emergency room visits, and breathless episodes.

The effect of clothing on inhalation volume

Diaphragmatic breathing is included as an important component of relaxation training protocols. In the present study, we report on the effectiveness of a simple behavioral technique to illustrate that choices of tight, restraining clothing significantly affect the inhalation volume of the breathing pattern. This study investigates the use of the incentive inspirometer to observe the effects of tight versus loose clothing on inhalation volume with 17 volunteer subjects. All had been trained in the use of the incentive inspirometer and slow diaphragmatic breathing (SDB) techniques. Inhalation volumes in the studies were measured with a 4000-ml incentive inspirometer and were recorded for one or two sequential breaths using SDB before and after loosening restrictive clothing. Loosening the subjects' clothing significantly increased inhalation volume. The results indicate that tight clothing significantly interferes with diaphragmatic breathing. We suggest that the demonstration of the effect of tight versus loose clothing can increase the clinician's awareness of the effects of clothing on breathing patterns. The technique also facilitates the acquisition of diaphragmatic breathing skills, and may raise the client's awareness that choices such as clothing can directly affect physiology.

Assessment of routine chest roentgenograms and the physical examination to confirm endotracheal tube position

We consecutively and prospectively studied 219 critically ill patients to evaluate the accuracy of the physical examination in assessing ETT position and the appropriateness of taking routine chest x-ray films after intubation in the ICU. As a result of x-ray findings, 14 percent of the patients required ETT repositioning, and 5 percent had main-stem intubations. Endobronchial intubation was more common in females than in males, and frequently occurred after emergency intubations. Sixty percent of the main-stem intubations occurred despite the presence of equal breath sounds on examination. Techniques to minimize the risk of tube malposition, such as cuff ballottement in the suprasternal notch and referencing the ETT centimeter markings, were not completely reliable. This study confirms the unreliability of the physical examination to assess ETT position. Chest x-ray films after intubation are indicated to verify tube position, particularly after emergency intubations. Other techniques such as use of a lighted stylet require evaluation to determine whether they are more cost-effective in verifying ETT placement in patients who have no other indication for postintubation x-ray films.

Adjunctive strategies to enhance peripheral warming: clinical techniques

This study investigates common successful strategies to increase peripheral temperature with biofeedback. Eighteen BCIA-certified therapists (average years of practice, 7.5) were interviewed by telephone for 30 to 45 minutes regarding successful peripheral warming strategies. The practitioners reported using multiple teaching strategies, either concurrently or sequentially. These responses were organized into an interrelated four-category model that consists of the following: (1) Attentional Category--shifting from active to passive attention; (2) General Arousal Category--shifting from hyper- to hypoarousal; (3) Proprioceptive/Kinesthetic Awareness Category--shifting from decreased to increased body awareness; (4) Self-Image/Self-Esteem Category--shifting from negative to positive self-image/self-esteem. These four categories and their corresponding techniques can be used to facilitate peripheral warming.

Can general surgery improve the outcome of the head-injury victim in rural America? A review of the experience in American Samoa

We analyzed the records of 50 head-injury patients managed by general surgeons from 1974 to 1981 in American Samoa. Patients were divided into three groups. Group 1 was awake and alert (n = 24). Group 2 was obtunded by talking (n = 7). Group 3 was comatose (n = 20). All patients were managed with diagnostic burr-hole procedures. Eighteen of the 20 unconscious patients had an intracranial hematoma. Five of the seven obtunded patients had an intracranial hematoma. Three of the nine deaths were directly attributable to a delay in diagnosis of an intracranial hematoma. We conclude that a burr-hole procedure in unconscious head-injury patients in rural hospitals is a safe and effective method of diagnosing and treating extradural and subdural hematomas. General surgery residents should receive training in operative head-injury management, to improve the care of the head-injury victim in rural America.

[Variability of normal grapho-elements and the assessment of abnormal grapho-elements in the EEG of clinically healthy test persons]

The percentage pattern and topical distribution of alpha, beta, theta and delta waves, the occipital voltage level asymmetry of the alpha waves and the frequency of temporal functional disorders were studied in 100 17-year-olds, 273 male test persons of various age and 6,000 healthy persons. The results indicated that 1/4--1/8 of the test section is precentrally taken up by theta waves in the E.E.G. of healthy 17-year-olds. Random sampling on a larger scale shows that left occipital alpha wave domination is just as frequent as on the right; voltage level symmetry occurs only in 13--23 per cent of all cases. Three per cent of the clinically healthy persons showed local temporal E.E.G. anomalies which were on the left in 96 per cent of the cases. Attention is drawn to possible consequences with regard to nomenclature, evaluation and diagnostic assessment.

[Incidence and significance of anamnestically indicated neurotic disorders in young applicants for flight training]

The histories of 17 years old clinically normal subjects show that 10% of them had functional disturbances or abnormalities in behaviour which are not to be considered as indications of latent neurotic development. Significant differences in EEG, size distribution, and reaction of the circulatory system during psycho-emotional stress (low-pressure chamber testing) may indicate a disharmonious physical maturation with increased disposition to circulatory lability and psychological abnormalities. The good intellectual performances and the favourable prognosis with regard to flight training are reasons for not disqualifying this group of applicants.

Biofeedback use of common objects: the bathroom scale in physical therapy

Many common devices can be used as biofeedback devices. The feedback use of the bathroom scale in rehabilitation medicine (physical therapy) has been explored with stroke patients. These patients used two scales, one under each foot, to relearn their sense of weight distribution. In addition, the scale was used to teach patients to shift their weight distribution from their knees to their hands as they learned to crawl, and from their feet to their buttocks and the chair as they learned to sit down.