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Biomedical subjects

J C Johnson

Publications and source records attributed to J C Johnson.

At least 73 records · Page 4Linked to original sources
PubMed1996

A biopsychosocial model of disability in rheumatoid arthritis.

OBJECTIVE: To test and cross-validate a model using disease activity, pain, and helplessness to predict future psychological and physical disability in persons with rheumatoid arthritis (RA) across time. METHODS: Measures of disease activity, pain, helplessness, psychological function, and physical function were collected from 63 males with RA at baseline, 3 months, and 6 months. Path analytic methods were used to examine longitudinal relationships among these variables. RESULTS: Path analysis revealed that pain and helplessness were significant mediators of the relationship between disease activity and future disability in RA; the predictive model withstood two cross-validations. CONCLUSION: The findings suggest that pain and helplessness are key biopsychosocial variables that affect the development of disability in RA.

Activities of Daily Living↗
PubMed1996

A family retreat as a comprehensive intervention for children with arthritis and their families.

OBJECTIVE: Family resources and coping skills are important to adaptation to pediatric chronic illness. Psychological and educational interventions have been found to enhance the coping skills of children with juvenile rheumatic disease (JRD) and their families. We examined the efficacy of a 3-day family retreat as a multidisciplinary, comprehensive treatment. METHODS: Children with JRD and their caregivers completed questionnaires assessing the children's behavioral and emotional functioning, pain, strain on caregivers' work and leisure activities, and caregivers' psychological distress before and 6 months after the family retreat. Principal caregivers were both parents for 16 children, mothers only for 10 children, and an aunt for 1 child. RESULTS: Improvements were found in children's emotional functioning, strain on caregivers' work, and strain on caregivers' leisure activities. Reductions in reported pain were not consistently revealed. CONCLUSIONS: Family retreats are an efficacious, multidisciplinary approach to helping families of children with JRD cope with the disease and its manifestations. Importantly, retreats offer a comprehensive intervention package that might not be available to families on an individual basis.

Adaptation, Psychological↗
PubMed1996

Suppression of spinal and cortical somatosensory evoked potentials by desflurane anesthesia.

The effect of the volatile anesthetic desflurane on spinal and cortical somatosensory evoked potentials (SEPs) was examined in 11 Sprague-Dawley male rats. Platinum recording electrodes were placed stereotactically over the left somatosensory cortex and dorsal midline of the T11-12 spinal cord while the right posterior tibial nerve was stimulated at twice motor threshold. The effect of desflurane was examined at various concentrations ranging from 0.7 to 11.4% (2 MAC). Mean arterial blood pressure (MAP) decreased (p = 0.001) progressively with increasing end-tidal desflurane concentrations. Concentrations of 1.4% (1/4 MAC) and 2.8% (1/2 MAC) did not significantly affect the spinal SEP (SSEP) amplitude or the latency. With higher concentrations, there was a progressive decrease in amplitude of the cortical SEPs (CSEPs; p = 0.002) and SSEPs (p = 0.008). However, CSEP and SSEP latencies did not change. At 5.7% (1 MAC), three animals (33%) lost CSEPs while SSEPs remained intact. At 11.4% (2 MAC), the CSEPs were lost in all animals. Only one rat lost the SSEPs at the 2 MAC concentration of desflurane, indicating the resistance of the SSEPs to desflurane anesthesia. We conclude that desflurane anesthesia significantly alters the amplitude of SSEPs and CSEPs without a significant change in the peak latency.

Anesthesia, Inhalation↗
PubMed1996

MR imaging appearance of the uterus in postmenopausal women receiving tamoxifen therapy for breast cancer: histopathologic correlation.

PURPOSE: To describe the spin-echo and dynamic gadolinium-enhanced magnetic resonance (MR) imaging appearance of the uterus in women receiving tamoxifen. MATERIALS AND METHODS: Thirty-five postmenopausal women with breast carcinoma receiving tamoxifen therapy underwent pelvic MR imaging. T1-weighted, T2-weighted, and dynamic gradient-echo T1-weighted sequences were used. Twenty-seven patients underwent uterine sampling within 3 months of MR imaging. RESULTS: Endometrial width on T2-weighted images ranged from 0.1 to 7.5 cm (mean thickness, 1.1 cm). Two uterine imaging patterns were noted. Patients with pattern 1 findings had homogeneous high signal intensity of the endometrium on T2-weighted images (mean, 0.5 cm) and enhancement of the endometrial-myometrial interface and a signal void in the lumen on gadolinium-enhanced images (18 patients). Patients with pattern 2 findings had heterogeneous endometrial signal intensity on T2-weighted images (mean, 1.8 cm) with enhancement of the endometrial-myometrial interface and latticelike enhancement traversing the endometrial canal on gadolinium-enhanced images (17 patients). Other imaging findings included subendometrial cysts, nabothian cysts, leiomyoma, and adenomyosis. Ten patients with pattern 1 findings had atrophic or proliferative endometria at histopathologic analysis; 12 of the 17 patients with pattern 2 findings had polyps, one of which had a focus of endometrial carcinoma. CONCLUSION: MR imaging of the uterus showed two distinct patterns in women receiving tamoxifen therapy.

Adult↗
PubMed1996

Reliability and validity of a submaximal treadmill test to estimate aerobic capacity in women with rheumatic disease.

OBJECTIVE: To assess reliability and validity of a single stage submaximal treadmill test to estimate aerobic capacity in women with rheumatic disease. METHODS: 30 women with rheumatic disease (rheumatoid arthritis = 19; systemic lupus erythematosus = 5; mixed connective tissue disease = 2; psoriatic arthritis = 4) performed a submaximal exercise test at a self-selected walking speed between 3.2 and 7.2 km/h on 2 occasions, and one subjective maximal exercise test with respiratory gas analysis. Estimation of aerobic capacity from the submaximal test was obtained from a regression equation using age, walking speed, and exercise heart rate. Aerobic capacity from maximal testing was determined by observed peak oxygen consumption and by estimation using test duration in a regression equation. Correlation and regression analyses were performed to assess test-retest reliability and criterion validity of the submaximal method. RESULTS: Intraclass correlation coefficient for the submaximal test was ICC = 0.97 (95% CI = 0.94-0.99). Comparison of results from the submaximal test to the maximal test using both observation and estimation methods to determine aerobic capacity ranged from r = 0.77 to 0.80, with R2 of 0.59 to 0.65. The submaximal regression model, originally developed and validated in a sample of persons without rheumatic disease, was significantly different in this sample of women with rheumatic disease. CONCLUSION: This single stage treadmill test, suitable for use in clinical and community settings, appears to be a reliable and valid method to safely assess aerobic capacity in women with rheumatic disease. There was a tendency for the submaximal method to overestimate aerobic capacity in this sample.

Adult↗
PubMed1995

Effects of stress management on clinical outcomes in rheumatoid arthritis.

OBJECTIVE: To examine the effects of stress-management training on clinical outcomes in persons with rheumatoid arthritis (RA). METHODS: Patients with RA (n = 141) were randomly assigned to 1 of 3 groups: a stress management group, an attention control group, or a standard care control group. The stress management and the attention control groups received a 10-week intervention followed by an additional 15-month maintenance phase. RESULTS: The stress management group showed statistically significant improvements on measures of helplessness, self-efficacy, coping, pain, and health status. Selected beneficial effects were still detectable at the 15-month followup evaluation. CONCLUSION: The data indicated that stress management interventions are capable of producing important clinical benefits for persons with RA.

Adaptation, Psychological↗
PubMed1995

Cochlear implants in young children with Usher's syndrome.

Usher's syndrome (US) is an autosomal recessive disorder characterized by congenital sensorineural hearing loss and retinitis pigmentosa. The majority of affected individuals have severe to profound sensorineural hearing loss and are therefore potential cochlear implant candidates. A goal of our otology program has been early identification and implantation of children with US. At our center, early diagnosis of US has been achieved by comprehensive ophthalmologic evaluation including electroretinography. Four of our 19 pediatric cochlear implant recipients with congenital sensorineural hearing loss were identified with US and implanted prior to the onset of signs or symptoms of visual loss. All children have received measurable benefit from cochlear implantation. In light of the dual sensory deficits present in US, the need for early diagnosis and cochlear implantation is of special importance in this population.

Child↗
PubMed1995

Selection of measures suitable for evaluating change in fibromyalgia clinical trials.

OBJECTIVE: To use growth curve model methods to investigate which of 46 variables associated with fibromyalgia (FM) clinical trials are potentially useful in measuring change. METHODS: For each of the 46 variables the reliability of change and corresponding standard error were estimated. Data were from a randomized clinical trial designed to compare the effectiveness of biofeedback/relaxation, exercise, and a combined program for the treatment of FM. There was also a control group. RESULTS: The reliabilities of change for the outcome variables Myalgic Score, Tenderpoint Count, and Tenderpoint Index, as well as the variable, number of words chosen from the McGill Pain Questionnaire were quite acceptable for both the 18 and 58 week time periods. There were 9 other variables that had reliabilities of change in the acceptable range. CONCLUSION: Thirteen of 46 variables considered had desirable reliabilities of change by the methods used. The 3 variables often used as measures of disease activity as well as one pain variable were among the 13. Data from this study produced no acceptable reliabilities of change for the 33 other variables. For these variables, further evaluation is required.

Clinical Trials as Topic↗
PubMed1994

Management of heart failure. II. Counseling, education, and lifestyle modifications.

OBJECTIVE: This article reviews the role of counseling, education, dietary modifications, and exercise for patients with heart failure due to left ventricular systolic dysfunction. DATA SOURCE: We reviewed studies published in English between 1966 and 1993 and referenced in MEDLINE or EMBASE. We used the search terms heart failure, congestive; congestive heart failure; heart failure; cardiac failure; and dilated cardiomyopathy in conjunction with terms for the specific areas of interest. Where data were lacking, we relied on opinions of panel members and peer reviewers. STUDY SELECTION AND DATA SYNTHESIS: Studies were reviewed to determine whether patients had heart failure due to systolic dysfunction (left ventricular ejection fraction, < 0.35 to 0.40) and whether clinical outcomes were reported. Studies that reported only intermediate outcomes (eg, hemodynamics) were not reviewed. CONCLUSION: Counseling and education can improve patient outcomes and decrease unnecessary hospitalizations. Patients with mild to moderate heart failure should be restricted to 3 g/d of sodium initially. Those who are unresponsive to this dosage or who have more severe disease should be advised to consume 2 g/d or less. Patients should be strongly advised to drink no more than 30 mL/d of alcohol or, preferably, to abstain completely. Exercise training is safe and can improve exercise duration and symptoms. Adherence to the treatment plan should be stressed and monitored at each visit. Clinicians should inform patients of the seriousness of their disease and their prognosis, but they should emphasize that patients can continue to remain active and enjoy a reasonable quality of life.

Counseling↗
PubMed1994

Evaluation of memory, learning ability, and clinical neurologic function in pathogen-free mice with systemic lupus erythematosus.

OBJECTIVE: To determine if neurologic impairment is related to progressive autoimmune disease in 3 murine models of systemic lupus erythematosus (SLE): MRL/lpr, NZB, and NZB/WF1. METHODS: Sensorimotor function, learning, and memory were tested within strains at specific ages, before and after the appearance of SLE. These parameters were also compared between strains for young and older lupus mice and their congenic controls with reduced autoimmune disease (MRL/lpr versus MRL/+; NZB versus NZB/xid). RESULTS: Abnormal neurologic features were present at a much higher frequency in MRL/lpr mice than in age-matched MRL/+ control mice, and sensorimotor function deficits were also seen in NZB/WF1 mice. Strains that develop lupus showed deficits on a water-escape, distal cue discrimination task and on a food-rewarded, proximal cue discrimination task, but the cognitive impairments were not global. CONCLUSION: MRL/lpr, NZB, and NZB/WF1 mice differed in terms of which behaviors were impaired as well as when those impairments appeared.

Age Factors↗
PubMed1994

Insertion of Groshong central venous catheters utilizing fluoroscopic techniques.

Groshong central line indwelling catheters are extensively used in gynecologic oncology patients for administration of chemotherapy, intravenous fluids, and pain medications. They are easy to maintain and have a good safety record. We report on the placement of these central venous catheters under direct fluoroscopic visualization as a method which is safe, inexpensive, and efficacious in high-risk patients. Fluoroscopic visualization during insertion provides several advantages: visualization of bony landmarks, placement of the guidewire into the subclavian vein and superior vena cava under direct visualization, and confirmation of appropriate distal placement of the Groshong catheter. Patient advantages include the following: (1) avoidance of unnecessary punctures to access the subclavian vein; (2) verification of guidewire placement to avoid cephalic placement; (3) passage of the guidewire only as far as the right atrium to avoid potential dysrrhythmias secondary to right ventricular irritation; and (4) a savings of approximately 60% over insertion in the general operating room. Thirty patients had placement under fluoroscopic visualization in the angiography suite of Georgetown University Hospital. The average age of the patients was 58 years (42-78). Sixteen patients had ovarian cancer, 6 had endometrial cancer, 5 had cervical cancer, and 3 had other gynecologic malignancies. Fifteen patients had catheters placed for chemotherapy, 14 for hydration, and 1 for pain control. Ten patients had had previous central venous catheters: 6 had been removed for infection, 2 for thrombus, 1 for completion of chemotherapy, and 1 for catheter kinkage. All 10 with previous catheters had successful placement of catheters in the angiography suite. Complications from insertion were minimal with one asymptomatic pneumothorax and one proximal port in an extravascular position. We present the technique of fluoroscopic insertion of Groshong catheters which is an effective method of placement in high-risk patients.

Adult↗
PubMed1994

Preservation of multiple oncogenic human papillomavirus types in recurrences of early-stage cervical cancers.

OBJECTIVES: Our purpose was to determine the relationship between human papillomavirus genotypes contained in primary early stage cervical cancers and those contained in the respective recurrences. STUDY DESIGN: Six early-stage cervical cancers that were considered cured by surgical extirpation subsequently recurred within 21 months of the original surgery. The primary tumors and the recurrences underwent polymerase chain reaction for human papillomavirus typing with confirmation of types performed by means of diagnostic restriction fragments. RESULTS: All primary tumors and recurrences contained human papillomavirus, with all primary tumors positive for multiple types. The concordance rate between the primary tumors and recurrences for specific types was 73% (11/15). Among the highly oncogenic types 16 and 18 there was 100% concordance between primary and recurrent tumors. CONCLUSIONS: Highly oncogenic types of human papillomavirus are preserved between primary tumors and their recurrences in cervical cancers. This further supports the role of oncogenic types in the maintenance of the malignant state and supports the clonogenic nature of cervical cancer recurrence.

Adult↗
PubMed1994

Pharmacokinetics of florfenicol following intravenous and intramuscular doses to cattle.

The disposition of florfenicol after single intravenous and intramuscular doses of 20 mg of florfenicol/kg of body weight (b.w.) to feeder calves was investigated. Serum florfenicol concentrations were determined by a sensitive high performance liquid chromatographic method with a limit of quantitation of 0.025 microgram/ml. The extent of serum protein binding of florfenicol was only 13.2% at a serum florfenicol concentration of 3.0 micrograms/ml. Serum concentration-time data after intravenous administration were best described by a triexponential equation. Total body clearance and steady state volume of distribution were 3.75 ml/min/kg b.w. and 761 ml/kg b.w., respectively. The terminal half-life after intravenous administration was 159 min. The absolute systemic availability after intramuscular administration was 78.5% (range: 59.3-106%) and the harmonic mean of the terminal half-life was 1098 minutes, indicating slow release of the florfenicol from the formulation at the intramuscular injection site.

Animals↗
PubMed1994

Complications of vascular access devices.

With the aging of society and the ever-expanding tools of modern medicine, the emergency physician is likely to encounter an increasing number of patients with externally hanging or internally implanted vascular access devices. Aseptic technique, proper access, and appropriate heparinization will provide safe yet rapid vascular access with minimal patient discomfort or risk of complication. On the other hand, patients who present to the emergency department with these devices already functioning should cause the ED physician to add potential catheter and/or pump complications to his or her differential diagnosis when evaluating the patient. In the case of implantable devices containing metal, the physician should be aware that access to electromagnetic radiation devices will be prohibited unless a nonmetallic device is utilized. Historically, the presence of such devices should be documented to prevent erroneous interpretation of imaging studies.

Catheterization, Central Venous↗
PubMed1994

[Comparison of the Combitube with the endotracheal tube in cardiopulmonary resuscitation in the prehospital phase].

A prospective controlled study was undertaken to evaluate the efficacy of the Combitube, a combined endotracheal and esophageal obturator airway adjunct, in prehospital cardiac arrest patients. The Combitube and a standard endotracheal tube were utilized on alternate days as the initial airway of choice by paramedics. Of altogether 86 patients treated during the study period, intubation was possible in 80 cases, 38 receiving a Combitube as initial choice of airway. 11 out of 14 patients who could not be intubated with a standard endotracheal tube were then successfully managed with a Combitube. Survival following cardiac arrest after insertion of a Combitube was comparable to conventional endotracheal intubation. Of the 6 patients who survived 2 had received a Combitube, 2 a standard endotracheal tube and 2 an oropharyngeal tube. While visualized endotracheal intubation remains the preferred method of airway control, the Combitube is an effective airway as backup to the endotracheal tube, as well as a primary airway, especially outside hospital. Contraindications are listed.

Allied Health Personnel↗